JP7421786B2 - transparent nonflammable sheet - Google Patents

Description

The present invention relates to a transparent noncombustible sheet, and specifically to a transparent noncombustible sheet suitable for smokeproof hanging walls, etc., and a smokeproof hanging wall using the same.

The Building Standards Act and the Building Standards Act Enforcement Order stipulate that smoke exhaust equipment must be installed to prevent the flow of smoke, toxic gas, etc. generated in the event of a building fire, and to facilitate evacuation and firefighting operations. There is. Therefore, in buildings such as office buildings and commercial facilities, smoke-proof hanging walls are often installed as smoke exhaust equipment and smoke-blocking equipment.

Smoke-proof hanging walls are usually installed in buildings for the purpose of temporarily blocking smoke, toxic gas, etc. from flowing into hallways and upper floors in the event of a fire, and securing the time necessary for evacuation. It is attached to the ceiling. For this reason, in order to prevent smoke-proof hanging walls from obstructing the field of view or spoiling the aesthetics, transparent plate glass, transparent resin composites of glass fiber and resin, etc. are used as smoke-proof hanging walls. A transparent resin composite of glass fiber and resin has the advantage that it is less likely to break than transparent plate glass. For example, Patent Document 1 discloses a transparent noncombustible sheet containing a glass fiber fabric and a cured resin layer.

Further, Patent Document 2 discloses a nonflammable sheet having at least one glass fiber fabric and a photocurable resin impregnated into the glass fiber fabric, the glass fibers in the glass fiber fabric comprising The difference in refractive index between the glass composition and the photocurable resin is 0.02 or less, the ratio of the glass fiber fabric to the nonflammable sheet is 20 to 70% by weight, and the photocurable resin is based on the nonflammable sheet. A nonflammable sheet is disclosed in which the proportion of the resin is 80 to 30% by weight, and the photocurable resin is obtained by curing a composition containing at least brominated vinyl ester.

Further, Patent Document 3 describes a first polycarbonate sheet layer containing 5% by mass to 20% by mass of bromine and having a thickness of 100 μm to 150 μm, and a polycarbonate sheet layer laminated on the first polycarbonate sheet layer and having a basis weight of 30 g/m. A cured resin composition layer containing a cured resin composition containing 10% to 30% by mass of bromine, which is impregnated into a glass fiber fabric of ² to 80 g/m ² , is laminated to the cured resin composition layer and contains bromine. A transparent noncombustible sheet is disclosed, comprising a laminate comprising a second polycarbonate sheet layer containing 5% by mass to 20% by mass and having a thickness of 100 μm to 150 μm, and having a thickness of 300 μm to 400 μm. . This document discloses that the cured resin composition includes a cured product of a tetrabromobisphenol A type epoxy resin or a cured product of a brominated vinyl ester resin.

Japanese Patent Application Publication No. 2005-319746 Japanese Patent Application Publication No. 2014-213489 Patent No. 6470454

The Building Standards Act requires smoke-proof hanging walls to be constructed of noncombustible materials. The requirements for the certification test for noncombustible materials include that in the prescribed exothermic test, the total calorific value for 20 minutes after the start of heating is 8 MJ/ ^m2 or less, and that the maximum heat generation rate continues for 10 seconds or more during the 20 minutes after the start of heating. This includes not exceeding 200kw/ ^m2 . The above-mentioned total calorific value tends to increase as the amount of resin (g/m ² ) contained in the sheet increases.

For example, in Patent Document 1, a sheet with a resin content of 300 g/ ^m2 is disclosed as Example 2, but the total calorific value is 8.74 MJ/ ^m2 , which meets the requirements of the qualification test for noncombustible materials. Not satisfied.

On the other hand, in Patent Document 2, a photocurable resin obtained by curing a composition containing brominated vinyl ester is used as a photocurable resin impregnated into a glass fiber fabric, so that the resin weight is 200 g/m ² or more. This is said to solve the problem of not being able to obtain nonflammability certification. Here, since the refractive index of brominated vinyl ester is considerably higher than the refractive index of glass fiber fabric, if the cured resin layer is impregnated with glass fiber fabric using brominated vinyl ester alone, the glass Light is scattered at the interface between the fibers and the cured resin, resulting in a nonflammable sheet with poor transparency. Therefore, in the example of Patent Document 2, the transparency of the nonflammable sheet is improved by adding neopentyl glycol methacrylate (NPG) as a reactive diluent and a refractive index modifier to the brominated vinyl ester.
However, according to the studies of the present inventors, although the nonflammable sheet of Patent Document 2 can improve the nonflammability, depending on the type of refractive index adjusting agent, the light of fluorescent lamps can be seen through the nonflammable sheet. There have been problems in that colors such as red and blue sometimes appear blurred, and the suppression of color blurring is not sufficient.

Further, Patent Document 3 discloses that a tetrabromobisphenol A type epoxy resin is contained as a cured resin composition containing 10% by mass to 30% by mass of bromine, which is impregnated into a glass fiber fabric. It is said that this makes it possible to suppress the total calorific value and to satisfy the noncombustibility performance as a transparent noncombustible sheet even if the film is thick. Here, since the refractive index of the tetrabromobisphenol A type epoxy resin is considerably higher than the refractive index of the glass fiber fabric, the cured resin contained in the tetrabromobisphenol A type epoxy resin alone is impregnated into the glass fiber fabric. If it is made into a layer, light will be scattered at the interface between the glass fiber and the cured resin, resulting in a nonflammable sheet with poor transparency. Therefore, in Patent Document 3 as well, it is necessary to add a resin for adjusting the refractive index to the tetrabromobisphenol A type epoxy resin. However, according to the studies of the present inventors, although the nonflammable sheet of Patent Document 3 can improve the nonflammability, depending on the type of refractive index adjusting agent, the light of fluorescent lamps can be seen through the nonflammable sheet. There have been problems in that colors such as red and blue sometimes appear blurred, and the suppression of color blurring is not sufficient.

Then, the present inventors conducted a thorough investigation into the causes of insufficient suppression of color bleeding in Patent Documents 2 and 3 mentioned above, and found that brominated vinyl ester and brominated epoxy resin contained as flame retardant components were It has been found that there are cases in which the occurrence of color bleeding is not sufficiently suppressed by the inclusion of the compound.

Therefore, the present invention solves the above problems and can suppress the decrease in the Abbe number of cured resin components other than the flame-retardant component due to the flame-retardant component while increasing the non-flammability of a sheet containing a glass fiber fabric and a resin. An object of the present invention is to provide a transparent noncombustible sheet and a smokeproof hanging wall using the transparent noncombustible sheet.

The present inventors have discovered that when a tetrabromobisphenol A type epoxy resin or a brominated vinyl ester resin is used as the cured resin as in Patent Documents 2 and 3, the Abbe number of the resulting cured resin layer becomes low. It has been learned that color bleeding may occur in the nonflammable sheet obtained due to this.

Therefore, as a result of intensive studies by the present inventors, it has been found that by containing an organic bromine monomer compound in the cured resin layer, the Abbe number is lower than when containing a brominated epoxy resin or a brominated vinyl ester. The researchers found that it is possible to suppress the occurrence of color bleeding while increasing nonflammability. The present invention was completed through further studies based on these findings.

That is, the present invention provides inventions of the following aspects.
Item 1. A transparent noncombustible sheet comprising a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric, the cured resin layer containing an organic bromine monomer compound.
Item 2. Item 2. The transparent nonflammable sheet according to Item 1, wherein the organic bromine monomer compound is tetrabromobisphenol A.
Item 3. Item 3. The transparent nonflammable sheet according to Item 1 or 2, wherein the cured resin layer contains a cured resin that does not contain bromine in its skeleton.
Item 4. 4. The transparent nonflammable sheet according to any one of Items 1 to 3, wherein the transparent nonflammable sheet has a total light transmittance of 85% or more and a haze of 10% or less.
Item 5. 5. The transparent nonflammable sheet according to any one of items 1 to 4, wherein the cured resin layer has an Abbe number of 30 or more.
Item 6. A second resin layer is included in the thickness direction of the transparent noncombustible sheet, the second resin layer is included in the glass fiber fabric without being impregnated, and has a bromine concentration of 30% by mass or more. The transparent nonflammable sheet according to any one of items 1 to 5.
Section 7. Radiant electricity measured in accordance with "4.10.2 Heat generation test and evaluation method" in the "Fireproof performance test and evaluation work method manual" (revised version on March 1, 2014) of the Building Materials Testing Center, a general incorporated foundation. 7. The transparent noncombustible sheet according to any one of items 1 to 6, which has a total calorific value of 8 MJ/m ² or less in a heat generation test in which the surface of the sheet is irradiated with 50 kW/m 2 of radiant heat from a heater.
Section 8. The method for producing a transparent nonflammable sheet according to any one of Items 1 to 7, comprising curing a resin composition containing a cured resin having an Abbe number of 30 or more and the organic bromine monomer compound. A method for producing a transparent nonflammable sheet, including the step of forming the cured resin layer.

According to the transparent nonflammable sheet of the present invention, the transparent noncombustible sheet includes a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric, wherein the cured resin layer is made of an organic bromine monomer. Since it contains a compound, it is possible to suppress a decrease in the Abbe number of the cured resin layer while increasing the nonflammability. Therefore, the transparent non-combustible sheet can suppress the occurrence of color bleeding while increasing its non-combustibility, and can be suitably used for smoke-proof hanging walls and the like.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram explaining one aspect|mode of the transparent noncombustible sheet of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram explaining one aspect|mode of the transparent noncombustible sheet of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram explaining one aspect|mode of the transparent noncombustible sheet of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram explaining one aspect|mode of the transparent noncombustible sheet of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram explaining one aspect|mode of the transparent noncombustible sheet of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram explaining one aspect|mode of the transparent noncombustible sheet of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram explaining one aspect|mode of the transparent noncombustible sheet of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram explaining one aspect|mode of the transparent noncombustible sheet of this invention. 4.10.2 Regarding the test equipment used when performing the heat generation test and evaluation method in the “Fireproof performance test and evaluation work method manual” (revised version on March 1, 2014) of the Building Materials Testing Center, a general incorporated foundation. It is a figure showing an outline. 4.10.2 Regarding the test equipment used when performing the heat generation test and evaluation method in the “Fireproof performance test and evaluation work method manual” (revised version on March 1, 2014) of the Building Materials Testing Center, a general incorporated foundation. FIG. 2 is a schematic diagram of the included test holder and presser frame. The unit of numerical values (dimensions) shown in FIG. 10 is mm.

The transparent noncombustible sheet of the present invention includes a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric, wherein the cured resin layer contains an organic bromine monomer compound. It is characterized by containing.

For example, as shown in FIGS. 1 to 8, the transparent noncombustible sheet 1 of the present invention includes a glass fiber fabric 2 and a cured resin layer 3 (hereinafter referred to as a first cured resin layer) impregnated in the glass fiber fabric 2. ), and the first cured resin layer 3 contains an organic bromine monomer compound.

In the transparent nonflammable sheet 1 of the present invention, at least one glass fiber fabric 2 may be included, and a plurality of glass fiber fabrics 2 may be included. Further, as shown in FIGS. 1 to 8, in the transparent noncombustible sheet 1 of the present invention, the first cured resin layer 3 fills the gaps between the glass fibers constituting the glass fiber fabric 2, One surface side portion of the first cured resin layer 3 and the other surface side portion communicate through the gap. As shown in FIGS. 3, 5, 6, and 8, the transparent nonflammable sheet 1 of the present invention includes a plurality of first cured resin layers 3 impregnated with a glass fiber fabric 2. You can do it like this. Although not shown in FIGS. 1 to 8, a plurality of glass fiber fabrics 2 may be included in one first cured resin layer 3.

For example, as shown in FIGS. 3 to 8, the transparent noncombustible sheet 1 of the present invention can include a second resin layer 4 that is included in the glass fibers in an unimpregnated state. The second resin layer 4 may be a single layer as shown in FIGS. 3 and 6, or may be a plurality of layers as shown in FIGS. 4, 5, 7, and 8. When the second resin layer 4 has multiple layers, it is preferably 2 to 5 layers, more preferably 2 to 3 layers.

For example, the transparent nonflammable sheet 1 shown in FIGS. 3, 5, 6, and 8 has a laminated structure in which the first cured resin layer 3 is laminated on both surfaces of the second resin layer 4. ing. In addition, the transparent nonflammable sheets 1 shown in FIGS. 4, 5, 7, and 8 have a laminated structure in which second resin layers 4 are laminated on both surfaces of the first cured resin layer 3, respectively. ing. In the transparent nonflammable sheet 1 of the present invention, a specific example of the laminated structure of the first cured resin layer 3 and the second resin layer 4 is as shown in FIGS. 3 and 6. Laminated structure in which second resin layer 4/first cured resin layer 3 are laminated in this order; second resin layer 4/first cured resin layer 3/second resin layer as shown in FIGS. 4 and 7; Laminated structure in which resin layers 4 are laminated in this order; second resin layer 4 / first cured resin layer 3 / second resin layer 4 / first cured resin layer 3 as shown in FIGS. 5 and 7 /A laminated structure in which the second resin layers 4 are laminated in this order can be mentioned.

In the transparent nonflammable sheet 1 of the present invention, layers other than the first cured resin layer 3 and the second resin layer 4 may be provided. For example, as shown in FIG. 2 and FIGS. 6 to 8, the transparent nonflammable sheet 1 of the present invention may include a film layer 5. It is preferable that one film layer 5 is included on the outside of the first cured resin layer 3 and the second resin layer 4. Although not shown, the transparent noncombustible sheet 1 of the present invention may be provided with a cover layer that is peeled off when used as a smoke-proof hanging wall, for example. Each layer constituting the transparent nonflammable sheet 1 of the present invention will be described in detail below.

[Glass fiber fabric 2]
In the transparent nonflammable sheet 1 of the present invention, the glass fiber fabric 2 is impregnated with a first cured resin layer 3, which will be described later. In the transparent nonflammable sheet 1 of the present invention, the glass fiber fabric 2 contributes to improving the nonflammability of the sheet. The refractive index of the glass fiber fabric 2 can be set to be similar to the refractive index of the first cured resin layer 3, which will be described later. The structure can be such that the total light transmittance is 85% or more and the haze is 10% or less, which are preferable indicators. In other words, the composition of the total light transmittance of 85% or more and the haze of 10% or less, which are preferable indicators of transparency of the transparent noncombustible sheet 1 of the present invention, is based on at least the refractive index of the glass fiber fabric 2. and the refractive index of the first cured resin layer 3 described later are sufficiently approximate (for example, the difference between the refractive index of the glass fiber fabric 2 and the refractive index of the first cured resin layer 3 is 0.02 or less). ) to show that one is doing something.

In the transparent noncombustible sheet 1 of the present invention, the weave structure of the glass fiber fabric 2 is not particularly limited, and examples include plain weave, satin weave, twill weave, basket weave, and ribbed weave, with plain weave being preferred.

The glass material of the glass fibers constituting the glass fiber fabric 2 is not particularly limited, and for example, known glass materials can be used. Examples of glass materials include alkali-free glass (E glass), acid-resistant alkali-containing glass (C glass), high-strength/high-modulus glass (S glass, T glass, etc.), alkali-resistant glass (AR glass), etc. Preferably, highly versatile alkali-free glass (E glass) is used. The glass fibers constituting the glass fiber fabric 2 may be made of one type of glass material, or may be a combination of two or more types of glass fibers made of different glass materials. Moreover, from the viewpoint of improving transparency, it is preferable to select a glass material having a refractive index similar to that of the first cured resin layer 3, which will be described later.

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. From the viewpoint of further improving transparency, the glass fiber count is preferably 20 tex or less, preferably 3 to 6 tex, and more preferably 3 to 5 tex. The number of glass fibers may be one type or a combination of two or more types. Note that the tex count of glass fiber corresponds to the number of grams per 1000 m.

The glass fibers constituting the glass fiber fabric 2 are preferably glass yarns 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. Further, the diameter of the single fibers in the glass yarn is preferably about 3.0 to 6.0 μm, more preferably about 3.0 to 5.0 μm, from the viewpoint of further improving the transparency of the transparent noncombustible sheet 1. The count of the glass yarn is preferably 2 to 30 tex, more preferably 2 to 12 tex, and 2 to 5 tex from the viewpoint of further improving the transparency of the transparent noncombustible sheet 1 while improving the noncombustibility of the transparent noncombustible sheet 1. More preferred.

In the transparent noncombustible sheet 1, the sum of the total mass (g/m ² ) of the glass fiber fabric 2 and the total mass (g/m ² , excluding the glass fiber fabric 2) of the first cured resin layer 3 described below. The ratio (mass%) of the total mass of the glass fiber fabric 2 in the transparent noncombustible sheet 1 to the amount (g/m ² ) improves transparency when the resin weight in the transparent noncombustible sheet is increased. In addition, in accordance with "4.10.2 Pyrogenicity test and evaluation method" in the "Fireproof performance test and evaluation work method manual" (revised version on March 1, 2014) of the Building Materials Testing Center, a general incorporated foundation, which will be described later. The total calorific value (hereinafter sometimes abbreviated as "gross calorific value") measured in a heat generation test in which radiant heat of 50 kW/m ² is irradiated onto the surface of the sheet from a radiant electric heater shall be low. From the viewpoint of further achieving compatibility with the above, the amount is preferably 20 to 60% by mass, and more preferably 30 to 60% by mass. In addition, the total mass of the glass fiber fabric ² in the transparent noncombustible sheet 1 ( g/m ² ) (mass %) is preferably 5 to 60 mass % from the viewpoint of achieving both improved transparency and lower total calorific value. In addition, when the second resin layer 4 and/or film layer 5, which will be described later, is provided, the total mass (g/m The ratio (mass%) of the total mass (g/m ² ) of the glass fiber fabric 2 in the transparent noncombustible sheet 1 to 2) is more preferably 5 to 28 mass% ^, even more preferably 5 to 25 mass%, 8 to 19 mass is particularly preferred. The mass (g/m ² ) of each glass fiber fabric 2 is preferably 10 to 120 (g/m ² ), more preferably 10 to 60 (g/m ² ), and more preferably 20 to 40 (g/m 2 ). ² ) is more preferred. In addition, the total mass (g/m ² ) of the glass fiber fabric 2 in the transparent noncombustible sheet 1 is such that the transparency of the transparent noncombustible sheet 1 is further improved while improving the noncombustibility of the transparent noncombustible sheet 1. From this point of view, it is preferably 10 to 120 (g/m ² ), more preferably 20 to 100 (g/m ² ), and particularly preferably 30 to 80 (g/m ² ).

The difference in refractive index between the glass fiber fabric 2 and the first cured resin layer 3 described below is preferably 0.02 or less, more preferably 0.01 or less. The refractive index of the glass fiber fabric 2 is preferably about 1.50 to 1.58, more preferably about 1.53 to 1.57.

The refractive index of the glass fiber fabric 2 is measured in accordance with method B of JIS K 7142:2008. Specifically, first, the glass fibers constituting the glass fiber fabric are crushed to such an extent that Becke lines can be observed when observed using an optical microscope at a magnification of 400 times. Using a halogen lamp equipped with an interference filter for D-rays as a light source, the refraction was observed and measured using an optical microscope at a magnification of 400 times and a temperature of 23°C, and the average value of the three tests was taken. Let be the value of the rate. Further, the refractive index of the first cured resin layer 3 and the second resin layer 4 is measured according to method B of JIS K 7142:2008. Specifically, the first cured resin layer 3 or the second resin layer 4 is crushed to such an extent that Becke lines can be observed when observed using an optical microscope at a magnification of 400 times. Using a halogen lamp equipped with an interference filter for D-rays as a light source, the refraction was observed and measured using an optical microscope at a magnification of 400 times and a temperature of 23°C, and the average value of the three tests was taken. Let be the value of the rate.

The difference in Abbe number between the glass fiber fabric 2 and the first cured resin layer 3 is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. The Abbe number of the glass fiber fabric 2 is preferably 30 to 80, more preferably 40 to 70, even more preferably 50 to 65. Note that the Abbe numbers of the first cured resin layer 3 and the glass fiber fabric 2 are each measured as follows.

(Abbe number of first cured resin layer 3)
Using the resin constituting the first cured resin layer 3, a sheet not containing the glass fiber fabric 2 was produced with a width of 8 mm, a length of 20 mm, and a thickness of 1 mm, and was subjected to Abbe refraction according to JIS K 7142A method. DR-M2 manufactured by Atago Co., Ltd. was used as a meter, diiodomethane was used as a contact liquid, D line (589 nm), F line (486 nm), and C line (656 nm) were used as interference filters, and the measurement temperature was 23 ° C. . The refractive index of each of the D-line, F-line, and C-line is measured, and the Abbe number is calculated according to the following formula (I).
Abbe number = (n _D -1)/(n _F -n _C ) (I)
n _D : Refractive index at D line n _F : Refractive index at F line n _C : Refractive index at C line

(Abbe number of glass fiber fabric 2)
Using the glass material constituting the glass fiber, it was manufactured to have a width of 8 mm, a length of 20 mm, and a thickness of 1 mm, and was prepared according to the JIS K 7142A method using DR-M2 manufactured by Atago Co., Ltd. as an Abbe refractometer and diiodomethane as a contact liquid. was used, D line (589 nm), F line (486 nm), and C line (656 nm) were used as interference filters, and the measurement temperature was set at 23°C. The refractive index of each of the D-line, F-line, and C-line is measured, and the Abbe number is calculated according to the following formula (I).
Abbe number = (n _D -1)/(n _F -n _C ) (I)
n _D : Refractive index at D line n _F : Refractive index at F line n _C : Refractive index at C line

The thickness per sheet of the glass fiber fabric 2 is, for example, about 10 to 100 μm from the viewpoint of further improving the transparency of the transparent noncombustible sheet 1 while improving the noncombustibility of the transparent noncombustible sheet 1. , 10 to 55 μm is preferable, and about 10 to 35 μm is more preferable. When the thickness of the glass fiber fabric 2 is 10 to 35 μm, it is particularly preferable that the glass volume fraction of the glass fiber fabric 2 calculated by the following formula (II) is 38% or more. The glass fiber fabric 2 having a thickness of 10 to 35 μm and a glass volume fraction of 38% or more can be obtained, for example, by subjecting a glass fiber fabric to an opening treatment.

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

(First cured resin layer 3)
In the transparent nonflammable sheet 1 of the present invention, the first cured resin layer 3 is impregnated with the glass fiber fabric 2, and is formed by curing a resin composition containing a curable resin. The cured resin layer 3 contains an organic bromine monomer compound. Thereby, it is possible to suppress a decrease in the Abbe number of the first cured resin layer 3 while increasing the nonflammability of the transparent nonflammable sheet 1.

Moreover, in the first cured resin layer 3 , the glass fiber fabric 2 is included in a state in which it is not exposed to the outside of the first cured resin layer 3 . Further, as described later, when the second resin layer 4 is included, the second resin layer 4 is included in the glass fiber fabric without being impregnated. Therefore, at least when the first cured resin layer 3 and the second resin layer 4 are in contact with each other, the glass fiber fabric 2 is not exposed on the surface of the first cured resin layer 3. , the glass fiber fabric 2 is included in the first cured resin layer 3. As mentioned above, the first cured resin layer 3 can be selected and set so as to approximate the refractive index of the glass fiber fabric 2, which can reduce light scattering on the glass fiber surface and improve the overall performance described below. The structure can have a light transmittance of 85% or more and a haze of 10% or less.

The first cured resin layer 3 is a cured product obtained by applying energy such as light or heat to a resin composition containing a curable resin (a photocured resin composition or a thermocured resin composition). (resin composition).

As the curable resin used for forming the first cured resin layer 3, from the viewpoint of further improving the transparency of the transparent nonflammable sheet 1, the first cured resin layer 3 and the above-mentioned glass fiber fabric 2 are It is preferable that the ratio can be approximated. The curable resin is preferably one in which the curable resin composition is photocurable, such as vinyl ester resin, urethane acrylate resin, fluorene acrylate resin, unsaturated polyester resin, curable acrylic resin, epoxy resin, etc. It will be done. Among these, in the case of providing the film layer 5, from the viewpoint of further improving the adhesiveness with the film layer 5, a curable acrylic resin is more preferable, and a cured resin composition containing acrylic syrup is particularly preferable. In the present invention, acrylic syrup refers to a polymerizable liquid mixture in which a (meth)acrylic acid ester polymer such as polymethyl methacrylate (PMMA) is dissolved in an acrylic monomer such as methyl methacrylate. Among the above acrylic syrups, one or more acrylic acid ester polymers selected from the group consisting of polymethyl methacrylate, methyl methacrylate/methyl acrylate copolymer, and methyl methacrylate/n-butyl acrylate copolymer are used as methacrylic syrups. Acrylic syrup dissolved in acid methyl monomer is particularly preferred. In this way, when the first cured resin layer 3 is made of a cured resin composition containing acrylic syrup, the adhesion with the film layer 5 is further improved, so that the transparency of the transparent nonflammable sheet 1 is improved. This is preferable because the improvement is further improved. Moreover, it is preferable that the first cured resin layer 3 includes a cured resin that does not contain bromine in its skeleton.

In addition, examples of the organic bromine monomer compounds contained in the resin composition constituting the first cured resin layer 3 include hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, hexabromocyclodecane, decabromodiphenyl ether, One or more types selected from the group consisting of octabromodiphenyl ether, hexabromodiphenyl ether, bis(pentabromophenoxy)ethane, ethylene-bis(tetrabromophthalimide), and tetrabromobisphenol A can be mentioned. Among these, tetrabromobisphenol A is preferred from the viewpoint of improving the solubility in the curable resin solution and further suppressing a decrease in the Abbe number originally possessed by the curable resin. In addition, the transparent nonflammable sheet 1 of the present invention can be produced by using an organic bromine monomer compound as a flame retardant component in the first cured resin layer 3 impregnated with the glass fiber fabric 2. From radiant electric heaters measured in accordance with "4.10.2 Heat generation test and evaluation method" in the "Fireproof performance test and evaluation work method manual" (revised version on March 1, 2014) of the Building Materials Testing Center Corporation. In an exothermic test in which the surface of the sheet is irradiated with radiant heat of 50 kW/m ² , it can also have the effect of making it even more difficult for cracks and holes that penetrate to the back surface, which are harmful in terms of fire protection, to occur for 20 minutes after the start of heating. That is, when a phosphorus-based flame retardant (for example, 1,3-phenylene bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), etc.) is used as a flame retardant component, the first cured resin Blistering of the layer may occur, and the glass fiber fabric 2 may become easily deformed accordingly. This phenomenon is more likely to occur especially when the glass fiber fabric 2 is lightweight, such as having a mass of, for example, 40 g/m ² or less. On the other hand, when the first cured resin layer 3 contains an organic bromine monomer, the above-mentioned blistering is suppressed, and cracks and holes penetrating to the back surface, which are harmful in terms of fire protection, are even less likely to occur.

The Abbe number of the first cured resin layer 3 is preferably 30 or more, more preferably 33-60, and particularly preferably 35-50. Further, the bromine concentration of the first cured resin layer 3 is preferably 5 to 30% by mass from the viewpoint of making the transparent noncombustible sheet of the present invention excellent in flame resistance and even more excellent in transparency. , more preferably 5 to 26% by weight, even more preferably 8 to 20% by weight, even more preferably 10 to 16.7% by weight. In the present invention, the bromine concentration is measured by EDS analysis. Specifically, the cut surface of the transparent noncombustible sheet 1 in the thickness direction as illustrated in FIGS. The measurement sample was made such that the length of the layer was 1 cm, and the measurement was made at one arbitrary point near the center of the layer to be measured in the thickness direction using a JEOL Ltd. product name JSM-6390A as the device. , let that value be the bromine concentration in each layer.

When the transparent noncombustible sheet 1 of the present invention includes a second resin layer 4 described below, the bromine concentration of the second resin layer 4 is preferably higher than the bromine concentration of the first cured resin layer 3. That is, the present inventors found that if the bromine concentration in the resin impregnated into the glass fiber fabric becomes excessively high, the calorific value of the resin decreases, but the refractive index of the resin becomes lower than the refractive index of the glass fiber fabric. It has been learned that the transparency of the resulting sheet is likely to be impaired. Therefore, by making the first cured resin layer 3 impregnated into the glass fiber fabric with a relatively low bromine concentration, the difference in refractive index with the glass fiber fabric 2 can be easily reduced. In addition, a second resin layer 4 that is included in the glass fiber fabric 2 in an unimpregnated state is laminated separately from the first cured resin layer 3 that is included in the glass fiber fabric 2 in an impregnated state, and By making the second resin layer 4 contained in an unimpregnated state with a relatively high bromine concentration, the low heat generation property of the resin with a high bromine concentration can be fully utilized, and when the resin weight is increased, it becomes transparent. It has been found that it is possible to achieve both improved performance and lower total calorific value.

In the transparent nonflammable sheet 1 of the present invention, the difference between the bromine concentration (mass %) of the first cured resin layer 3 and the bromine concentration (mass %) of the second resin layer 4 (= second resin layer The bromine concentration of 4 - the bromine concentration of the first cured resin layer 3) is, for example, 3% by mass or more, which improves transparency when the resin weight is increased and lowers the total calorific value. From the viewpoint of achieving greater compatibility with the above, 5 to 50% by mass is preferred, 10 to 50% by mass is more preferred, and 20 to 50% by mass is particularly preferred.

Moreover, the resin composition constituting the first cured resin layer 3 may further contain additives such as a curing accelerator, an ultraviolet absorber, a filler, and a photopolymerization initiator. Examples of the ultraviolet absorber include benzotriazole. Examples of fillers include calcium carbonate, silica, and talc. As a photopolymerization initiator, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1- one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy- 2-Methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2 -dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]- Examples include 1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. Among these, when using a curable acrylic resin as the first cured resin layer 3, 1-hydroxy-cyclohexyl-phenyl-ketone is preferable from the viewpoint of improving transparency. These additives may be used alone or in combination of two or more. When the first cured resin layer 3 contains an additive, the content thereof is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass.

In the transparent nonflammable sheet 1 of the present invention, the total mass of the resin composition of the first cured resin layer 3 (mass excluding the glass fiber fabric 2) is, for example, 20 to 250 g/m ² , and the resin weight From the viewpoint of further achieving both improved transparency and better nonflammability when increasing the amount, 20 to 200 g/m ² is preferably mentioned, and 20 to 120 g/m ² are more preferred, and 20 to 80 g/m ² are particularly preferred. Further, the thickness per layer of the first cured resin layer 3 (the thickness including the glass fiber fabric 2) is, for example, 20 to 150 μm, and when the resin weight is increased, the transparency is From the viewpoint of further achieving both the improvement and the non-flammability, 20 to 100 μm is preferred, and 20 to 50 μm is more preferred.

In the transparent nonflammable sheet 1 of the present invention, the refractive index of the first cured resin layer 3 is preferably about 1.50 to 1.58, more preferably about 1.53 to 1.57.

(Second resin layer 4)
In the transparent nonflammable sheet 1 of the present invention, the second resin layer 4 can be included in the glass fiber fabric 2 without being impregnated. As described above, the bromine concentration of the second resin layer 4 is preferably higher than the bromine concentration of the first cured resin layer 3. In the transparent nonflammable sheet 1 of the present invention, a first cured resin layer 3 is included in the glass fiber fabric 2 in an impregnated state, and a second cured resin layer 3 is included in the glass fiber fabric 2 in an unimpregnated state. As the second resin layer 4 which is laminated with the resin layer 4 and is included in the glass fiber fabric 2 without being impregnated, a resin having a relatively high bromine concentration can be used. This eliminates the need for the transparent nonflammable sheet 1 of the present invention to approximate the refractive index of the glass fiber fabric 2, such as diluting it with another resin with a low bromine concentration as in Patent Document 2, and reduces the bromine concentration. The low heat generation properties of high quality resin can be fully utilized.

The bromine concentration in the second resin layer 4 of the transparent nonflammable sheet 1 of the present invention is, for example, 31% by mass or more, from the viewpoint of further suppressing the total calorific value and increasing the resin weight. are mentioned, and 35% by mass is preferably mentioned. The upper limit is not particularly limited, but may be, for example, 60% by mass or less, or 55% by mass or less.

Examples of the resin used to form the second resin layer 4 include thermoplastic resins and curable resins. Examples of the thermoplastic resin include polyvinyl chloride resin, polyester resin, polyolefin resin, polyamide resin, and the like. Further, examples of the curable resin include vinyl ester resin, urethane acrylate resin, fluorene acrylate resin, unsaturated polyester resin, curable acrylic resin, and epoxy resin. Among these, from the viewpoint of further improving the transparency of the transparent nonflammable sheet 1, the second resin layer 4 is preferably formed of a curable resin.

Examples of methods for including bromine in the second resin layer 4 include a method in which the resin constituting the second resin layer 4 is made into a resin containing bromine atoms as a substituent, a method in which a flame retardant containing bromine atoms is used as a curable resin Examples include a method of adding a resin composition to a resin.

Examples of the resin containing a bromine atom as a substituent include curable resins containing a bromine atom as a substituent. Examples of the curable resin containing a bromine atom as a substituent include brominated epoxy resin, brominated vinyl ester resin, and brominated unsaturated polyester resin. Examples of the thermoplastic resin containing a bromine atom as a substituent include brominated polycarbonate resin, brominated polyurethane resin, and brominated polyester resin.

Examples of the above-mentioned flame retardants containing a bromine atom include decabromodiphenyl, tetrabromobisphenol A (TBBA) and its derivatives, bis(pentabromophenyl)ethane, 1,2-bis(2,4,6-tribromophenoxy) ) Phenyl oxide flame retardants such as ethane, brominated polystyrene, hexabromocyclododecane, hexabromobenzene, pentabromobenzyl acrylate, pentabromobenzyl acrylate, decabromodiphenyl oxide, octabromodiphenyl oxide, and tetrabromodiphenyl oxide, etc. It will be done. Examples of the resin containing the flame retardant include a resin containing a bromine atom as a substituent, a curable resin exemplified in the first cured resin layer 3, and the like.

In the transparent nonflammable sheet 1 of the present invention, the total mass of the second resin layer 4 is, for example, 100 to 600 g/m ² , preferably 180 to 500 g/m ² . Further, the thickness per layer of the second resin layer 4 is, for example, 80 to 600 μm, preferably 100 to 400 μm.

In the transparent nonflammable sheet 1 of the present invention, the refractive index of the second resin layer 4 is not particularly limited, but is, for example, 1.570 to 1.650, more preferably 1.572 to 1.620, even more preferably is 1.580 to 1.620. Moreover, the difference between the refractive index of the glass fiber fabric 2 and the refractive index of the second resin layer 4 includes a difference exceeding 0.01, and a difference exceeding 0.02.

Further, while improving the transparency of the transparent non-flammable sheet 1 of the present invention and lowering the total calorific value, it is further possible to increase the resin weight of the transparent non-flammable sheet 1. , from the viewpoint of effectively increasing mechanical strength, the total content of resins constituting the first cured resin layer 3 and the second resin layer 4 (all the first cured resins contained in the transparent nonflammable sheet 1) The total weight of the cured resin layer 3 (excluding the mass of the glass fiber fabric 2) and the second resin layer 4 is preferably 200 g/m ² or more, more preferably 240 g/m ^{2 or more, and even more preferably 270 g/m 2} or more. Examples include m ² or more. Note that the upper limit of the total content is, for example, 600 g/m ² or less.

In addition, from the same viewpoint, the total thickness of the first cured resin layer 3 and the second resin layer 4 (the total thickness of the first cured resin layer 3 and the second resin layer 4 included in the transparent noncombustible sheet 1) The total diameter is preferably 180 μm or more, more preferably 200 μm or more, and still more preferably 240 μm or more. In addition, as an upper limit of the said total thickness, 500 micrometers or less and 450 micrometers or less are mentioned, for example.

(Film layer 5)
In the transparent noncombustible sheet 1 of the present invention, the film layer 5 is laminated on the first cured resin layer 3 or the second resin layer 4 as necessary to further improve the initial tear strength of the transparent noncombustible sheet 1. play the role of It is preferable that one film layer 5 is included on the outside of the first cured resin layer 3 and the second resin layer 4.

The material constituting the film layer 5 is not particularly limited. Examples include polyester resin, polycarbonate resin, polyolefin resin, fluororesin, acrylic resin, and polyamide resin. On the other hand, the film layer 5 preferably contains a thermoplastic resin other than polyvinyl chloride resin. Examples of thermoplastic resins other than polyvinyl chloride resins include those that can be formed into a film even with a small amount of plasticizer, and biaxially oriented thermoplastic resins containing amorphous thermoplastic resins other than polyvinyl chloride resins. Films are preferred. Examples of thermoplastic resins other than polyvinyl chloride resins include polyester resins, polycarbonate resins, fluororesins, acrylic resins, and polyamide resins, and at least one of these resins may be included. Furthermore, the film layer 5 may not contain polyvinyl chloride resin. From the viewpoint of further improving the initial tear strength of the transparent noncombustible sheet 1, the film layer 5 has an Elmendorf tear propagation resistance of 1 N/mm or more in both the vertical and horizontal directions. 3 to 20 N/mm is preferred, and 5 to 15 N/mm is more preferred. Among these, from the viewpoint of further achieving both chemical resistance (including alkaline detergent resistance when used as a smoke-proof hanging wall), improvement of initial tear strength, and transparency, the film layer 5 should contain polyester resin. It is preferable that the Examples of the polyester resin include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). The Elmendorf tear propagation resistance was determined by measuring the tear strength (N) based on JIS K7128-2/1998 using an Elmendorf tearing machine manufactured by Toyo Seiki Seisakusho Co., Ltd., and dividing this measured value by the film thickness. Means tear propagation resistance (N/mm). Furthermore, the tear strength is the average value of the test results of 20 samples in each of the vertical and horizontal directions. Furthermore, if the film layer 5 is made of a resin composition containing PVDF and an acrylic resin (PMMA, etc.), the film layer 5 can have excellent weather resistance while also being able to form a film with the first cured resin layer 3 and the second resin layer 4. It has excellent adhesion and is suitable as a membrane material.

In the transparent nonflammable sheet of the present invention, it is preferable that the film used as the film layer 5 has excellent transparency and smoothness. Regarding the transparency of the film used as the film layer 5, for example, the total light transmittance (JIS K 7105:1981) is preferably 90% or more, more preferably 91 to 98%. Further, for example, the haze (JIS K 7105:1981) is preferably 1.5% or less, more preferably 0.3 to 1.0%.

(Antistatic layer containing metal or metal compound)
The transparent noncombustible sheet 1 of the present invention can be provided with an antistatic layer containing a metal or a metal compound as the outermost layer when used as a smoke-proof hanging wall, for example.

In the antistatic layer containing a metal or a metal compound, examples of the metal elements included include Ag, Ni, Cu, Sn, Sb, Al, In, Ti, etc., and the standard electrode potential when used as a single metal is Examples include metal elements with a voltage of less than 0 eV. Examples of the metal compound include metal oxides (antimony pentoxide, tin oxide, zinc oxide, indium oxide, antimony-doped indium oxide, tin-doped indium oxide, silver oxide, etc.). Further, the antistatic layer may not contain fine particles made of barium sulfate, calcium carbonate, aluminum oxide, magnesium silicate, glass, or the like. Examples of the form in which the metal or metal compound is contained include a metal or metal compound thin film formed by vapor deposition, sputtering, plating, etc., or a layer in which metal or metal compound fine particles are dispersed in a fixed resin. Examples of the shape of the metal or metal compound fine particles include granules, flakes, and needles (fibers). The average particle diameter of the metal or metal compound fine particles is, for example, the average particle diameter determined using the BET method (calculated as the average particle diameter by a conventional method from the specific surface area (m ² /g) measured by the nitrogen gas adsorption method). By setting the specific surface area (diameter) to 100 nm or less, which is the wavelength of visible light or less, preferably 1 to 100 nm, the transparency of the transparent nonflammable sheet 1 can be more easily maintained.

When the antistatic layer containing metal or metal compound fine particles contains metal or metal compound fine particles, it preferably contains a fixing resin that fixes the metal or metal compound fine particles to the base material. That is, it is preferable that the antistatic layer is a layer containing a fixed resin and metal or metal compound fine particles dispersed in the fixed resin. Examples of the fixing resin include polyurethane resin, polyester resin, acrylic resin, polyether resin, cellulose resin, polyvinyl alcohol resin, epoxy resin, polyvinylpyrrolidone, polystyrene resin, polyethylene glycol, and pentaerythritol. Among them, polyurethane resins, polyester resins, and acrylic resins are particularly preferred. The acrylic resin may be, for example, a modified acrylic resin (urethane modified, polyester modified, polycarbonate modified, fluorine modified, etc.). The mass of the antistatic layer is, for example, 0.1 to 10 g/m ² per layer, preferably 0.1 to 5 g/m ² , and more preferably 0.1 to 3 g/m ² . 0.1 to 1 g/m ² is particularly preferred. Further, the thickness of the antistatic layer is, for example, 0.01 to 3 μm per layer, preferably 0.05 to 1 μm. In the antistatic layer, the mass ratio of the fixed resin and the metal or metal compound fine particles (mass of the fixed resin (g/m ² ):mass of the metal or metal compound fine particles (g/m ² )) is 10: The ratio is preferably 1 to 1:1, more preferably 8:1 to 2:1, and particularly preferably 4:1 to 2:1. Furthermore, the surface smoothness when an antistatic layer containing a metal or a metal compound is provided includes, for example, a surface roughness Ra of 1 to 200 nm. Further, the ratio of the mass (g/m ² ) of the metal and metal compound fine particles to the total mass (g/m ² ) of the antistatic layer is 50 to 10 mass%, preferably 30 to 20 mass%. Can be mentioned.

(peelable cover layer that is peeled off during use)
The transparent noncombustible sheet 1 of the present invention may be formed of the first cured resin layer 3, the second resin layer 4, or the outside of the film layer 5 (the antistatic layer 6 is attached to the first cured resin layer 3, A removable cover layer that is peeled off during use can be further laminated on the second resin layer 4 or, if provided outside the film layer 5, on the outside of the antistatic layer 6. A peelable cover layer can be suitably provided on the outermost surface of the transparent nonflammable sheet 1 of the present invention. As a result, when the transparent noncombustible sheet 1 of the present invention is used as a smokeproof hanging wall, for example, it becomes easier to prevent damage to the transparent noncombustible sheet 1 from occurring during construction and deterioration of transparency and aesthetic appearance.

As the releasable cover layer to be peeled off during use, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a polyester film, etc. can be used. Among them, if a light-transmitting protective film is used as the removable cover layer that is peeled off during use, for example, the resin composition forming the first cured resin layer 3 or the second resin layer 4 described above can be used. When making a photocurable curable resin composition, it is important to be aware that during the curing process of the curable resin composition, scratches may occur on the surface of the outermost layer during use, reducing transparency and aesthetic appearance. This is preferable because it is easier to prevent. The above-mentioned light transmittance is not particularly limited as long as it transmits light that cures the photocurable resin, but for example, it transmits light with a wavelength of 100 to 400 nm, or transmits light with a wavelength of 250 to 400 nm. Can be mentioned. The light transmittance of the cover layer is preferably 40% or more, with an average transmittance of 50% at a measurement wavelength of 250 to 400 nm, as measured by a UV transmittance meter (product name: UV3150, manufactured by Shimadzu Corporation), for example. It is more preferably 60% or more, and particularly preferably 60% or more.

Note that the peelable cover layer that is peeled off during use is not particularly limited in terms of transparency and smoothness since it is peeled off during use, such as a smoke-proof hanging wall. For example, from the viewpoint of cost, the total light transmittance is about 80 to 95% (JIS K 7105:1981), and the haze is about 2 to 10% (JIS K 7105:1981).

(Physical properties of transparent nonflammable sheet 1)
The transparent noncombustible sheet 1 of the present invention has a total light transmittance (total light transmittance after peeling off the cover layer if it includes a peelable cover layer that is peeled off during use) of 85% or more, and a haze (when used). When a removable cover layer that is sometimes peeled off is included, it is preferable that the haze after peeling off the cover layer is 10% or less. As mentioned above, the configuration in which the transparent nonflammable sheet 1 of the present invention has a total light transmittance of 85% or more and a haze of 10% or less is based on at least the refractive index of the glass fiber fabric 2 and the first cured resin layer 3. (For example, the difference between the refractive index of the glass fiber fabric 2 and the refractive index of the first cured resin layer 3 is 0.02 or less.) Show that. The total light transmittance is preferably 90% or more. Further, the haze is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less. The total light transmittance of the transparent nonflammable sheet 1 is a value obtained by measuring according to JIS K7361-1 1997, and the haze is a value obtained by measuring according to JIS K 7136:2000.

The thickness of the transparent noncombustible sheet 1 of the present invention is, for example, the thickness of the transparent noncombustible sheet 1 after removing the removable cover layer that is removed during use (i.e., the removable cover layer that is removed during use). The thickness (excluding layers) is 200 to 700 μm, preferably 250 to 600 μm. In addition, as the mass of the transparent noncombustible sheet 1 of the present invention, for example, the mass of the transparent noncombustible sheet 1 after peeling off the removable cover layer that is peeled off during use (i.e., the removable cover layer that is peeled off during use) (excluding mass) is 200 to 800 g/m ² , preferably 400 to 750 g/m ² . In addition, the total weight of the resin in the transparent nonflammable sheet 1 after peeling off the peelable cover layer that is peeled off during use (for example, if the transparent nonflammable sheet 1 has the laminated structure shown in FIG. 4, the first curing The total resin mass of the resin layer 3, second resin layer 4, and film layer 5 is, for example, 300 to 700 g/ ^m2 , preferably 390 to 700 g/ ^m2 , and 450 to 650 g/m2. ² is more preferred.

The transparent noncombustible sheet 1 of the present invention has a structure in which the transparent noncombustible sheet 1 after peeling off the removable cover layer that is peeled off during use is based on the "Fireproof Performance Testing and Evaluation Procedures Manual" of the Building Materials Testing Center, a general incorporated foundation. In a heat generation test in which the surface of the sheet is irradiated with 50kW/ ^m2 of radiant heat from a radiant electric heater, which is measured in accordance with "4.10.2 Heat generation test/evaluation method" in the revised edition of March 1, 2014). , the total calorific value is preferably 8 MJ/m ² or less. Further, the transparent nonflammable sheet 1 of the present invention has a maximum heat generation rate of 10 seconds or more after the start of heating in the above exothermic test, after the peelable cover layer that is peeled off during use is peeled off. It is preferable not to exceed 200kW/ ^m2 continuously.

In addition, in the present invention, according to "4.10.2 Pyrogenicity test/evaluation method" in "Fireproof performance test/evaluation work method manual" (revised version on March 1, 2014) of the Building Materials Testing Center, a general incorporated foundation. The total calorific value (MJ/m ² ) and the maximum heat generation rate after the start of heating exceed 200 kW/m ² in a heat generation test in which radiant heat of 50 kW/m ² is irradiated onto the surface of the sheet from a radiant electric heater. Specifically, the time (S) is determined according to the contents described in the test specimen, test apparatus, and test conditions shown below.

[Test specimen]
(1) The number of test specimens (sheets) shall be three.
(2) The shape and dimensions of the test specimen shall be a square with each side measuring 99 mm±1 mm.
[Test equipment]
(1) A schematic diagram of the test equipment used is shown in FIG. The test equipment consists of a conical radiant electric heater, an ignition plug, a radiant heat shield, a test specimen holder, a gas concentration analyzer, an exhaust system capable of measuring gas flow rate, and a heat flow meter.
(2) The radiant electric heater shall be capable of stably and uniformly irradiating the surface of the test piece with 50 kW/m ² of radiant heat.
(3) The radiant heat shielding plate shall be capable of protecting the test specimen from radiant heat before the test begins.
(4) A schematic diagram of the test holder and presser frame included in the test device is shown in FIG. The specimen holder is made of stainless steel and has a square shape with external dimensions of 106 mm ± 1 mm on a side, a depth of 25 mm ± 1 mm, and a thickness of 2.15 mm ± 0.25 mm. A square opening of .0 mm±0.5 mm shall be provided in the center. The holding frame is made of stainless steel and has a square shape with an inner dimension of 111 mm ± 1 mm on a side and a depth of 54 mm ± 1 mm.
(5) The exhaust system shall be equipped with a centrifugal exhaust fan, hood, vent, exhaust duct, orifice plate flow meter, etc. that function effectively at the test temperature. The distance between the lower end of the hood and the surface of the test specimen shall be 210 mm ± 50 mm, and in this state, the exhaust system's exhaust system shall have a flow rate of 0.024 m ³ /s or more when converted to standard temperature and standard pressure. . To measure the exhaust flow rate, an orifice with an inner diameter of 57 mm±3 mm is provided between the hood and the duct. For the purpose of exhaust gas sampling, a ring sampler with 12 holes 2.2 mm ± 0.1 mm in diameter is mounted 685 mm ± 15 mm from the hood with the holes facing away from the flow. Also, the temperature of the exhaust gas is measured at the center of the exhaust duct at a position 100 mm±5 mm upstream from the orifice. The orifice is installed at a location that does not affect flow measurement.
(6) The gas analyzer shall be capable of continuously and accurately measuring the concentrations of oxygen, carbon monoxide, and carbon dioxide in exhaust gas.
(7) The spark plug shall be capable of supplying power from a 10 kV transformer or induction coil system. The distance between the spark electrodes is 3 mm±0.5 mm, and the position of the electrodes is, in principle, 13 mm±2 mm on the central axis of the test piece.
(8) The heat flow meter uses a Schmidt-Boulder type that can measure up to 100 kW/m ² ±10 kW/m ² . The heat sensing part of the heat flow meter is assumed to be circular with a diameter of 12.5 mm, and the emissivity of the surface is 0.95±0.05.
[Test condition]
(1) The test time shall be 20 minutes after radiant heat is irradiated onto the surface of the test piece and an electric spark is activated at the same time. However, the measurement may be terminated when combustion clearly no longer continues.
(2) The test specimen was wrapped with aluminum foil with a thickness of 0.025 mm or more and 0.04 mm or less on the side and back sides, placed in a holding frame, and inorganic fibers (nominal thickness 13 mm, density 65 kg/m ³ ) and then push it into the test specimen holder.
(3) During the test, radiant heat of 50 kW/m ² is applied to the surface of the test specimen from a radiant electric heater.
(4) Adjust the exhaust gas flow rate to 0.024 m ³ /s±0.002 m ³ /s.
(5) Until the start of the test, use a radiant heat shield to prevent the test specimen from receiving radiant heat.
(6) Before moving the radiant heat shield, set the ignition plug in the specified position.
[measurement]
(1) Measure the concentrations of oxygen, carbon monoxide, and carbon dioxide at intervals of 5 seconds or less.
(2) Using the method shown below, calculate the heat generation rate per unit area (kW/m ² ), and then calculate the total heat generation amount per unit area (MJ/m ² ) as the heat generation rate during the time from the start to the end of heating. Calculated by accumulating.

The heat generation rate (q) is calculated according to the following formula.

here,
V ₂₉₈ = C (Δp・Te) ^1/2 /350 (: flow rate in the duct at 25°C)
E=17.2×10 ³ kJ/m ³
X ⁰ _O2 : Average value of oxygen concentration based on 1-minute baseline measurement X _O2 : Actual measured value of oxygen concentration
q”=q/As
here,
As: initial exposed area of test specimen (0.0088 m ² ).
C (orifice coefficient) is the oxygen concentration (X _O2 ) and differential pressure when methane is burned at a flow rate corresponding to a heat generation rate of q _b = 5 kW ± 0.5 kW in this measurement under a specified exhaust flow rate. Calculate from (Δp) using the following formula.
C=q _b / (△hc/ro×1.10) (Te/△p) ^1/2 (1.105-1.5X _O2 )/(0.2095-X _O2 )
here,
q _b : Heat generation rate of supplied methane △hc/ro: 12.54×10 ³ kJ/kg for methane
Te: Gas temperature in the exhaust duct (value measured near the two-way pitot tube)

(Method for manufacturing transparent nonflammable sheet 1 of the present invention)
The method for manufacturing the transparent nonflammable sheet 1 of the present invention is not particularly limited. For example, a method for manufacturing a transparent nonflammable sheet may be mentioned, which includes a step of curing a resin composition containing a cured resin having an Abbe number of 30 or more and the organic bromine monomer compound to form the cured resin layer. Specifically, first, the above-mentioned glass fiber fabric 2 and a resin composition constituting the first cured resin layer 3 are prepared. Next, after applying and impregnating the glass fiber fabric 2 with the above resin composition, the thickness and content of the resin composition are adjusted using a squeezing roller or the like. Next, the resin composition is cured by heating or the like to obtain a transparent noncombustible sheet 1 in which the glass fiber fabric 2 is impregnated with the first cured resin layer 3. In addition, a process film such as polyethylene terephthalate coated with the above resin composition is prepared, and the film is pressure-bonded from both sides of the glass fiber fabric 2 to impregnate the resin composition from both sides of the glass fiber fabric 2. After the material is cured, the process film is peeled off to obtain a transparent nonflammable sheet 1 in which the glass fiber fabric 2 is impregnated with the first cured resin layer 3.

When curing the resin composition by applying thermal energy, the heating temperature is not particularly limited and can be, for example, about 50 to 200°C. Furthermore, when the resin composition is cured by applying light energy, the resin composition is irradiated with light and cured. The conditions for light irradiation may be, for example, an integrated light amount of 100 to 500 mJ/cm ² .

When the transparent noncombustible sheet 1 of the present invention has a film layer 5, after placing the above-mentioned resin film constituting the film layer 5 on the first cured resin layer 3 obtained above, a press machine or the like is used. The film layer 5 can be formed on the first cured resin layer 3 by heating and pressurizing the first cured resin layer 3.

In addition, when producing the transparent nonflammable sheet 1 including the second resin layer 4, for example, the first step is to prepare an intermediate containing the glass fiber fabric 2 impregnated with the first cured resin layer 3. The method may include one step and a second step of laminating the second resin layer 4 on the intermediate body. An example of the laminated structure shown in FIG. 3 will be described below.

The first step will be explained. In the first step, first, a glass fiber fabric 2 and an uncured curable resin composition to be the first cured resin layer 3 are prepared. At this time, an organic bromine monomer compound is contained in the curable resin composition. The uncured curable resin composition is applied to a process film (for example, a PET film, etc.), the glass fiber fabric 2 is placed on the applied uncured curable resin composition, and the uncured glass fiber fabric 2 is coated with the uncured curable resin composition. curable resin composition. Next, another process film (for example, PET film, etc.) is placed on top of the uncured curable resin composition impregnated into the glass fiber fabric 2, and pressure is applied with a roller from above the process film B. The mass of the cured resin layer 3 is adjusted. Thereafter, the uncured curable resin composition that is to be the first cured resin layer 3 is irradiated with light through the step PET film B using a black light fluorescent lamp to cure the curable resin composition. After forming the cured resin layer 3 of 1, one of the laminated process films (in this example, process film A for convenience) is peeled off, and the process film B/glass fiber fabric 2 is impregnated with it. An intermediate body having a laminated structure including the first cured resin layer 3 can be obtained. Two sheets of the intermediate are prepared. At this time, when the transparent nonflammable sheet 1 includes the film layer 5, the film layer 5 can be used instead of the process film B included in the intermediate. In addition, when the transparent noncombustible sheet 1 includes, for example, a film layer 5 and a peelable cover layer that is peeled off during use, the film layer 5 and a peelable cover layer that is peeled off during use are laminated in advance. The laminated film may be prepared as a laminated film, and the laminated film may be used in place of the process film B included in the intermediate so that the cover layer is on the surface side.

The second step will be explained using a case where the resin constituting the second resin layer 4 is a curable resin. In the second step, an uncured curable resin to be used as the second resin layer 4 is prepared, and the uncured curable resin is applied to the first cured resin layer of the intermediate obtained in the first step. Apply on 3 sides. Next, on the uncured curable resin that will become the second resin layer 4, place the other of the obtained intermediate so that the first cured resin layer 3 side becomes the second resin layer 4. The mass of the second resin layer 4 is adjusted by placing it so that the uncured curable resin side faces up and applying pressure with a roller from above the other intermediate. Thereafter, the uncured curable resin composition to be used as the second resin layer 4 is irradiated with light through the other intermediate using a black light fluorescent lamp to cure the curable resin composition, A second resin layer 4 is formed and laminated. By peeling off the process film B on both surfaces of the second resin layer 4, the first cured resin layer 3 contained in the glass fiber fabric 2 in an impregnated state/not impregnated in the glass fiber fabric 2 is obtained. It is possible to obtain the transparent nonflammable sheet 1 of the present invention, which has a laminated structure of the second resin layer 4 contained in the glass fiber fabric 2 and the first cured resin layer 3 contained in a state impregnated with the glass fiber fabric 2. In addition, when the film layer 5 is included, or when the cover layer is peelable during use, the uncured curable resin composition used as the second resin layer 4 is cured to form the second resin layer. After forming and laminating 4, the transparent nonflammable sheet 1 may be obtained by leaving the film layer 5 and the cover layer which can be peeled off during use without peeling.

(Applications of transparent nonflammable sheet 1 of the present invention)
The transparent noncombustible sheet 1 of the present invention can be used as a smoke-proof hanging wall that is hung from the ceiling of a building. Examples of smoke-proof hanging walls include known ones that use a transparent noncombustible sheet 1 made of glass fiber fabric and resin. a transparent noncombustible sheet 1 with a part held and suspended; and a pair of end mullions arranged on both sides of the transparent noncombustible sheet 1, the transparent noncombustible sheet 1 and the end part Examples include smoke-proof hanging walls that are separably joined to mullions. The smoke-proof hanging wall may also include a hanging wall in which a transparent noncombustible sheet 1 is stretched between two pairs of mullions, such as a transparent noncombustible sheet when installed hanging from a ceiling. An example of this is a smoke-proof hanging wall that does not have an opening on the lower side of No. 1. In addition, if the transparency is increased, it can be used as a substitute for glass, so it can be used in other applications where glass is used, such as partitions, room partitions, smoke-proof sheets, and smoke-proof curtains (such as those used in factories). ), etc.

The present invention will be explained in detail below by showing Examples and Comparative Examples. However, the present invention is not limited to the examples.

The resin composition constituting the first cured resin layer 3 impregnated into the glass fiber fabric 2 had the composition shown in Table 1, and in Examples 1 to 5, acrylic syrup (refractive index 1. 531), a mixture of tetrabromobisphenol A (TBBA, trade name "Frame Cut 120G" manufactured by Tosoh Corporation) and a photopolymerization initiator (Omnirad 184 manufactured by IGM) (mass ratio (acrylic syrup: TBBA: photopolymerization initiator) = 76:24:3).Furthermore, as the resin composition constituting the first cured resin layer 3 of Reference Example 1, acrylic syrup (refractive index 1.561) was used so as to have the composition shown in Table 1. ) and a photopolymerization initiator (Omnirad 184 manufactured by IGM) (mass ratio (acrylic syrup: photopolymerization initiator) = 100:3) was used. In addition, the first cured resin layer 3 of Comparative Example 1 was The constituent resin compositions had the compositions shown in Table 1, including acrylic syrup (refractive index 1.540), brominated vinyl ester resin (product name: Neopol 8197, manufactured by Nippon U-Pica Co., Ltd.), and a photopolymerization initiator ( A mixture of Omnirad 184 manufactured by IGM (mass ratio (acrylic syrup: brominated vinyl ester resin: photopolymerization initiator) = 65.7:34.3:3) was used without being impregnated into the glass fiber fabric 2. The resin compositions constituting the second resin layer 4 include a brominated vinyl ester resin (trade name: Neopol 8197, manufactured by Nippon U-Pica Co., Ltd.), a photopolymerization initiator ( A mixture of Omnirad 184) manufactured by IGM Co., Ltd. was used.The amount of the photopolymerization initiator was 3 parts by mass per 100 parts by mass of the brominated vinyl ester resin.As the film layer 5, a commercially available Omnirad 184) manufactured by Toyobo Co., Ltd. Axial stretched polyester film (trade name "Cosmoshine (registered trademark) A4300"), thickness 50 μm, mass 70 g/m ² , total light transmittance (JIS K 7105:1981) 93%, haze (JIS K 7105:1981) 0 .9%) was used.The removable cover layer to be peeled off during use is a polypropylene film (thickness 40 μm, mass 36 g/m ² ) on one side of which is releasably adhered to film layer 5. A PET film (thickness: 50 μm, total light transmittance: 93%, haze: 4% (JIS K 7105:1981)) coated with an acrylic acid ester adhesive was used as the process film.

<Example 1>
(Preparation of glass fiber fabric)
The product name "ECC1200 1/0 1.0Z" manufactured by Unitika Glass Fiber Co., Ltd. (average filament diameter 4.5 μm, average number of filaments 100, number of twists 1.0Z, count 4.2tex) was used as the warp and weft, and air A plain weave glass fiber fabric having a warp density of 90 threads/25 mm and a weft thread density of 90 threads/25 mm was obtained by weaving with a jet loom. Then, the spinning sizing agent and the weaving sizing agent adhering to the obtained glass fiber fabric were removed by heating at 400° C. for 30 hours. After that, the surface treatment agent silane coupling agent (S-350: N-vinylbenzyl-aminoethyl-γ-aminopropyltrimethoxysilane (hydrochloride) Chisso Corporation) was adjusted to a concentration of 15 g/L and squeezed with a padder roll. After that, it was dried and cured at 120°C for 1 minute. Then, the glass fiber fabric was widened once by water jet processing at a pressure of 1.5 MPa while the tension of the glass fiber fabric was set to 100 N/m in the warp direction to obtain a glass fiber fabric 2. The obtained glass fiber fabric had a warp density of 90/25 mm, a weft density of 90/25 mm, a thickness of 27 μm, a mass of 30 g/m ² , and a refractive index of 1.561.

(Manufacture of transparent nonflammable sheet)
The cured resin composition shown in Table 1 was applied onto the PET film which was the process film described above. Next, the prepared glass fiber fabric was placed on the cured resin composition and allowed to stand for 1 minute to impregnate the gap between the glass fiber fabric with the resin. Next, the above-mentioned process film, PET film, was placed on top, and pressure was applied from above with a roller. Thereafter, the resin composition was cured by irradiating the resin composition with light (light irradiation conditions: integrated light amount 200 mJ/cm ² ) together with the above-mentioned PET film, thereby forming the first cured resin layer 3 . Next, the PET film was removed to obtain a transparent nonflammable sheet having the laminated structure shown in FIG. In the obtained transparent noncombustible sheet, the gaps between the glass fibers of the glass fiber fabric are impregnated with a cured resin layer (cured product of the resin composition), and the cured resin is on both sides of the glass fiber fabric layer. layers were formed.

<Reference example 1>
(Preparation of glass fiber fabric)
The same glass fiber fabric as in Example 1 was prepared.

(Manufacture of transparent nonflammable sheet)
The cured resin composition shown in Table 1 was applied onto the PET film which was the process film described above. Next, the prepared glass fiber fabric was placed on the cured resin composition and allowed to stand for 1 minute to impregnate the gap between the glass fiber fabric with the resin. Next, the above-mentioned process film, PET film, was placed on top, and pressure was applied from above with a roller. Thereafter, the resin composition was cured by irradiating the resin composition with light (light irradiation conditions: integrated light amount 200 mJ/cm ² ) together with the above-mentioned PET film, thereby forming the first cured resin layer 3 . Next, the PET film was removed to obtain a transparent nonflammable sheet having the laminated structure shown in FIG. In the obtained transparent noncombustible sheet, the gaps between the glass fibers of the glass fiber fabric are impregnated with a cured resin layer (cured product of the resin composition), and the cured resin is on both sides of the glass fiber fabric layer. layers were formed.

<Comparative example 1>
(Preparation of glass fiber fabric)
The same glass fiber fabric as in Example 1 was prepared.

(Manufacture of transparent nonflammable sheet)
The cured resin composition shown in Table 1 was applied onto the PET film which was the process film described above. Next, the prepared glass fiber fabric was placed on the cured resin composition and allowed to stand for 1 minute to impregnate the gap between the glass fiber fabric with the resin. Next, the above-mentioned process film, PET film, was placed on top, and pressure was applied from above with a roller. Thereafter, the resin composition was cured by irradiating the resin composition with light (light irradiation conditions: integrated light amount 200 mJ/cm ² ) together with the above-mentioned PET film, thereby forming the first cured resin layer 3 . Next, the PET film was removed to obtain a transparent nonflammable sheet having the laminated structure shown in FIG. In the obtained transparent noncombustible sheet, the gaps between the glass fibers of the glass fiber fabric are impregnated with a cured resin layer (cured product of the resin composition), and the cured resin is on both sides of the glass fiber fabric layer. layers were formed.

<Example 2>
(Preparation of glass fiber fabric)
The same glass fiber fabric as in Example 1 was prepared.

(Lamination of antistatic layer on film layer 5)
An antistatic layer was laminated on one surface of Cosmoshine (registered trademark) A4300 (thickness: 50 μm) serving as the film layer 5. The antistatic layer is made by adding tin oxide fine particles (average particle size 20 nm) in a polyester resin as a binding resin such that the mass ratio of the binding resin to the tin oxide fine particles (fixing resin: tin oxide fine particles) is 75:25. The mixed and dispersed antistatic agent was coated on one side of Cosmoshine (registered trademark) A4300 (thickness: 50 μm) to serve as film layer 5, and then dried. The provided antistatic layer had a mass of 0.5 g/m ² and a thickness of 0.4 μm.

(Lamination of a removable protective film to film layer 5 (antistatic layer side) that is peeled off during use)
On the antistatic layer of Cosmoshine (registered trademark) A4300, which is the film layer 5 and has the antistatic layer on one side, the polypropylene is used as the peelable cover layer that is peeled off during use. A removable protective film that is coated with an acrylic ester adhesive on one side of the film and is laminated with the adhesive facing the antistatic layer, dried, and peeled off during use. A laminate X having a laminate structure of acrylic acid ester adhesive/antistatic layer/Cosmoshine (registered trademark) A4300 as film layer 5 was obtained. Two laminates X were prepared.

(Formation of the first cured resin layer 3 and lamination of the laminate A including the film layer 5 on the first cured resin layer 3)
A first cured resin layer 3 is formed on the Cosmoshine (registered trademark) A4300 side (that is, the side opposite to the peelable cover layer that is peeled off during use) of the laminate X obtained above.Table 1 A curable resin composition consisting of the acrylic syrup described in . Next, the obtained glass fiber fabric 2 is placed on top of the curable resin composition which will become the first cured resin layer 3, and the glass fiber fabric 2 is left to stand for 1 minute, and the acrylic syrup is applied to the gap between the glass fiber fabric 2. It was impregnated with a curable resin composition consisting of: Next, the PET film used as the process film described above is placed on the curable resin composition made of the acrylic syrup, and a roller is applied from above the PET film to reduce the mass of the first cured resin layer 3 to 25 g/m ² Pressure was applied so that Thereafter, the curable resin composition made of acrylic syrup, which will become the first cured resin layer 3, is passed through the PET film in the above process and irradiated with light (light irradiation) using a black light fluorescent lamp (product name: FL15BLB, manufactured by Toshiba Corporation). Conditions: the curable resin composition was cured using an integrated light amount of 200 mJ/cm ² ) to form the first cured resin layer 3, and then the laminated process PET film was peeled off so that it would not be peeled off during use. Peelable cover layer / Acrylic acid ester adhesive peelable together with the cover layer / Antistatic layer / Film layer 5 (Cosmoshine (registered trademark) A4300) / Contained in a state impregnated in the glass fiber fabric 2 A laminate Y having a laminate structure of the first cured resin layer 3 was obtained. In the obtained laminate Y, the first cured resin layer 3 (cured product of the resin composition) made of acrylic syrup is impregnated into the gaps between the glass fibers of the glass fiber fabric 2 without exposing the glass fibers. It had been. Two pieces of the laminate Y were prepared.

(Lamination of second resin layer 4 included in glass fiber fabric 2 in an unimpregnated state)
The second resin layer 4 included in the glass fiber fabric 2 in an unimpregnated state is on the side of the first cured resin layer 3 included in the glass fiber fabric 2 in an impregnated state of the laminate Y obtained above. A brominated vinyl ester resin composition as shown in Table 1 was applied. Next, the other side of the obtained laminate Y is placed on top of the brominated vinyl ester resin composition so that the first cured resin layer 3 side of the laminate Y is the brominated vinyl ester resin composition. The second resin layer 4 made of the brominated vinyl ester resin composition was pressed from above with a roller so that the mass of the second resin layer 4 made of the brominated vinyl ester resin composition was 149 g/m ² . Thereafter, the brominated vinyl ester resin composition which is to be the second resin layer 4 is passed through the other laminate Y and irradiated with light (light irradiation) using a black light fluorescent lamp (product name: FL15BLB manufactured by Toshiba Corporation). Conditions: the brominated vinyl ester resin composition is cured using an integrated light amount of 200 mJ/cm ² ) to form the second resin layer 4, and a peelable cover layer that is peeled off during use/can be peeled off together with the cover layer. acrylic ester adhesive/antistatic layer/film layer 5 (Cosmoshine (registered trademark) A4300)/first cured resin layer 3 impregnated in glass fiber fabric 2/glass fiber fabric 2 Second resin layer 4 included in an unimpregnated state/First cured resin layer 3 included in an impregnated state in the glass fiber fabric 2/Film layer 5 (Cosmoshine (registered trademark) A4300)/Antistatic layer A transparent nonflammable sheet 1 of the present invention was obtained, which has a laminated structure of /an acrylic ester pressure-sensitive adhesive that can be peeled off together with the cover layer/a peelable cover layer that can be peeled off during use. Note that the evaluation of the bromine concentration, total light transmittance, haze, total calorific value, and time over 200 kW of the transparent noncombustible sheet described below is based on the removable cover that is peeled off when using the transparent noncombustible sheet 1 obtained above. The peelable acrylic ester adhesive was peeled off along with the layer and the cover layer.

<Example 3>
(Preparation of glass fiber fabric)
The same glass fiber fabric as in Example 1 was prepared.

(Lamination of antistatic layer on film layer 5)
An antistatic layer was laminated on one surface of Cosmoshine (registered trademark) A4300 (thickness: 50 μm) serving as the film layer 5. The antistatic layer is made by adding tin oxide fine particles (average particle size 20 nm) in a polyester resin as a binding resin such that the mass ratio of the binding resin to the tin oxide fine particles (fixing resin: tin oxide fine particles) is 75:25. The mixed and dispersed antistatic agent was coated on one side of Cosmoshine (registered trademark) A4300 (thickness: 50 μm) to serve as film layer 5, and then dried. The provided antistatic layer had a mass of 0.5 g/m ² and a thickness of 0.4 μm.

(Lamination of a removable protective film to film layer 5 (antistatic layer side) that is peeled off during use)
On the antistatic layer of Cosmoshine (registered trademark) A4300, which is the film layer 5 and has the antistatic layer on one side, the polypropylene is used as the peelable cover layer that is peeled off during use. A removable protective film that is coated with an acrylic ester adhesive on one side of the film and is laminated with the adhesive facing the antistatic layer, dried, and peeled off during use. A laminate X having a laminate structure of acrylic acid ester adhesive/antistatic layer/Cosmoshine (registered trademark) A4300 as film layer 5 was obtained. Two laminates X were prepared.

(Formation of the first cured resin layer 3 and lamination of the laminate A including the film layer 5 on the first cured resin layer 3)
A first cured resin layer 3 is formed on the Cosmoshine (registered trademark) A4300 side (that is, the side opposite to the peelable cover layer that is peeled off during use) of the laminate X obtained above.Table 1 A curable resin composition consisting of the acrylic syrup described in . Next, the obtained glass fiber fabric 2 is placed on top of the curable resin composition which will become the first cured resin layer 3, and the glass fiber fabric 2 is left to stand for 1 minute, and the acrylic syrup is applied to the gap between the glass fiber fabric 2. It was impregnated with a curable resin composition consisting of: Next, the PET film used as the process film described above is placed on the curable resin composition made of the acrylic syrup, and a roller is applied from above the PET film to reduce the mass of the first cured resin layer 3 to 25 g/m ² Pressure was applied so that Thereafter, the curable resin composition made of acrylic syrup, which will become the first cured resin layer 3, is passed through the PET film in the above process and irradiated with light (light irradiation) using a black light fluorescent lamp (product name: FL15BLB, manufactured by Toshiba Corporation). Conditions: the curable resin composition was cured using an integrated light amount of 200 mJ/cm ² ) to form the first cured resin layer 3, and then the laminated process PET film was peeled off so that it would not be peeled off during use. Peelable cover layer / Acrylic acid ester adhesive peelable together with the cover layer / Antistatic layer / Film layer 5 (Cosmoshine (registered trademark) A4300) / Contained in a state impregnated in the glass fiber fabric 2 A laminate Y having a laminate structure of the first cured resin layer 3 was obtained. In the obtained laminate Y, the first cured resin layer 3 (cured product of the resin composition) made of acrylic syrup is impregnated into the gaps between the glass fibers of the glass fiber fabric 2 without exposing the glass fibers. It had been. Two pieces of the laminate Y were prepared.

(Lamination of second resin layer 4 included in glass fiber fabric 2 in an unimpregnated state)
The second resin layer 4 included in the glass fiber fabric 2 in an unimpregnated state is on the side of the first cured resin layer 3 included in the glass fiber fabric 2 in an impregnated state of the laminate Y obtained above. A brominated vinyl ester resin composition as shown in Table 1 was applied. Next, the other side of the obtained laminate Y is placed on top of the brominated vinyl ester resin composition so that the first cured resin layer 3 side of the laminate Y is the brominated vinyl ester resin composition. The second resin layer 4 made of the brominated vinyl ester resin composition was pressed from above with a roller so that the mass of the second resin layer 4 made of the brominated vinyl ester resin composition was 189 g/m ² . Thereafter, the brominated vinyl ester resin composition which is to be the second resin layer 4 is passed through the other laminate Y and irradiated with light (light irradiation) using a black light fluorescent lamp (product name: FL15BLB manufactured by Toshiba Corporation). Conditions: the brominated vinyl ester resin composition is cured using an integrated light amount of 200 mJ/cm ² ) to form the second resin layer 4, and a peelable cover layer that is peeled off during use/can be peeled off together with the cover layer. acrylic ester adhesive/antistatic layer/film layer 5 (Cosmoshine (registered trademark) A4300)/first cured resin layer 3 impregnated in glass fiber fabric 2/glass fiber fabric 2 Second resin layer 4 included in an unimpregnated state/First cured resin layer 3 included in an impregnated state in the glass fiber fabric 2/Film layer 5 (Cosmoshine (registered trademark) A4300)/Antistatic layer A transparent nonflammable sheet 1 of the present invention was obtained, which has a laminated structure of /an acrylic ester pressure-sensitive adhesive that can be peeled off together with the cover layer/a peelable cover layer that can be peeled off during use. Note that the evaluation of the bromine concentration, total light transmittance, haze, total calorific value, and time over 200 kW of the transparent noncombustible sheet described below is based on the removable cover that is peeled off when using the transparent noncombustible sheet 1 obtained above. The peelable acrylic ester adhesive was peeled off along with the layer and the cover layer.

<Example 4>
(Preparation of glass fiber fabric)
The same glass fiber fabric as in Example 1 was prepared.

(Lamination of antistatic layer on film layer 5)
An antistatic layer was laminated on one surface of Cosmoshine (registered trademark) A4300 (thickness: 50 μm) serving as the film layer 5. The antistatic layer is made by adding tin oxide fine particles (average particle size 20 nm) in a polyester resin as a binding resin such that the mass ratio of the binding resin to the tin oxide fine particles (fixing resin: tin oxide fine particles) is 75:25. The mixed and dispersed antistatic agent was coated on one side of Cosmoshine (registered trademark) A4300 (thickness: 50 μm) to serve as film layer 5, and then dried. The provided antistatic layer had a mass of 0.5 g/m ² and a thickness of 0.4 μm.

(Lamination of a removable protective film to film layer 5 (antistatic layer side) that is peeled off during use)
On the antistatic layer of Cosmoshine (registered trademark) A4300, which is the film layer 5 and has the antistatic layer on one side, the polypropylene is used as the peelable cover layer that is peeled off during use. A removable protective film that is coated with an acrylic ester adhesive on one side of the film and is laminated with the adhesive facing the antistatic layer, dried, and peeled off during use. A laminate X having a laminate structure of acrylic acid ester adhesive/antistatic layer/Cosmoshine (registered trademark) A4300 as film layer 5 was obtained. Two laminates X were prepared.

(Formation of the first cured resin layer 3 and lamination of the laminate A including the film layer 5 on the first cured resin layer 3)
A first cured resin layer 3 is formed on the Cosmoshine (registered trademark) A4300 side (that is, the side opposite to the peelable cover layer that is peeled off during use) of the laminate X obtained above.Table 1 A curable resin composition consisting of the acrylic syrup described in . Next, the obtained glass fiber fabric 2 is placed on top of the curable resin composition which will become the first cured resin layer 3, and the glass fiber fabric 2 is left to stand for 1 minute, and the acrylic syrup is applied to the gap between the glass fiber fabric 2. It was impregnated with a curable resin composition consisting of: Next, the PET film used as the process film described above is placed on the curable resin composition made of the acrylic syrup, and a roller is applied from above the PET film to reduce the mass of the first cured resin layer 3 to 25 g/m ² Pressure was applied so that Thereafter, the curable resin composition made of acrylic syrup, which will become the first cured resin layer 3, is passed through the PET film in the above process and irradiated with light (light irradiation) using a black light fluorescent lamp (product name: FL15BLB, manufactured by Toshiba Corporation). Conditions: the curable resin composition was cured using an integrated light amount of 200 mJ/cm ² ) to form the first cured resin layer 3, and then the laminated process PET film was peeled off so that it would not be peeled off during use. Peelable cover layer / Acrylic acid ester adhesive peelable together with the cover layer / Antistatic layer / Film layer 5 (Cosmoshine (registered trademark) A4300) / Contained in a state impregnated in the glass fiber fabric 2 A laminate Y having a laminate structure of the first cured resin layer 3 was obtained. In the obtained laminate Y, the first cured resin layer 3 (cured product of the resin composition) made of acrylic syrup is impregnated into the gaps between the glass fibers of the glass fiber fabric 2 without exposing the glass fibers. It had been. Two pieces of the laminate Y were prepared.

(Lamination of second resin layer 4 included in glass fiber fabric 2 in an unimpregnated state)
The second resin layer 4 included in the glass fiber fabric 2 in an unimpregnated state is on the side of the first cured resin layer 3 included in the glass fiber fabric 2 in an impregnated state of the laminate Y obtained above. A brominated vinyl ester resin composition as shown in Table 1 was applied. Next, the other side of the obtained laminate Y is placed on top of the brominated vinyl ester resin composition so that the first cured resin layer 3 side of the laminate Y is the brominated vinyl ester resin composition. The second resin layer 4 made of the brominated vinyl ester resin composition was pressed from above with a roller so that the mass of the second resin layer 4 made of the brominated vinyl ester resin composition was 229 g/m ² . Thereafter, the brominated vinyl ester resin composition which is to be the second resin layer 4 is passed through the other laminate Y and irradiated with light (light irradiation) using a black light fluorescent lamp (product name: FL15BLB manufactured by Toshiba Corporation). Conditions: the brominated vinyl ester resin composition is cured using an integrated light amount of 200 mJ/cm ² ) to form the second resin layer 4, and a peelable cover layer that is peeled off during use/can be peeled off together with the cover layer. acrylic ester adhesive/antistatic layer/film layer 5 (Cosmoshine (registered trademark) A4300)/first cured resin layer 3 impregnated in glass fiber fabric 2/glass fiber fabric 2 Second resin layer 4 included in an unimpregnated state/First cured resin layer 3 included in an impregnated state in the glass fiber fabric 2/Film layer 5 (Cosmoshine (registered trademark) A4300)/Antistatic layer A transparent nonflammable sheet 1 of the present invention was obtained, which has a laminated structure of /an acrylic ester pressure-sensitive adhesive that can be peeled off together with the cover layer/a peelable cover layer that can be peeled off during use. Note that the evaluation of the bromine concentration, total light transmittance, haze, total calorific value, and time over 200 kW of the transparent noncombustible sheet described below is based on the removable cover that is peeled off when using the transparent noncombustible sheet 1 obtained above. The peelable acrylic ester adhesive was peeled off along with the layer and the cover layer.

<Example 5>
(Preparation of glass fiber fabric)
The same glass fiber fabric as in Example 1 was prepared.

(Lamination of antistatic layer on film layer 5)
An antistatic layer was laminated on one surface of Cosmoshine (registered trademark) A4300 (thickness: 50 μm) serving as the film layer 5. The antistatic layer is made by adding tin oxide fine particles (average particle size 20 nm) in a polyester resin as a binding resin such that the mass ratio of the binding resin to the tin oxide fine particles (fixing resin: tin oxide fine particles) is 75:25. The mixed and dispersed antistatic agent was coated on one side of Cosmoshine (registered trademark) A4300 (thickness: 50 μm) to serve as film layer 5, and then dried. The provided antistatic layer had a mass of 0.5 g/m ² and a thickness of 0.4 μm.

(Lamination of a removable protective film to film layer 5 (antistatic layer side) that is peeled off during use)
On the antistatic layer of Cosmoshine (registered trademark) A4300, which is the film layer 5 and has the antistatic layer on one side, the polypropylene is used as the peelable cover layer that is peeled off during use. A removable protective film that is coated with an acrylic ester adhesive on one side of the film and is laminated with the adhesive facing the antistatic layer, dried, and peeled off during use. A laminate X having a laminate structure of acrylic acid ester adhesive/antistatic layer/Cosmoshine (registered trademark) A4300 as film layer 5 was obtained. Two laminates X were prepared.

(Formation of the first cured resin layer 3 and lamination of the laminate A including the film layer 5 on the first cured resin layer 3)
A first cured resin layer 3 is formed on the Cosmoshine (registered trademark) A4300 side (that is, the side opposite to the peelable cover layer that is peeled off during use) of the laminate X obtained above.Table 1 A curable resin composition consisting of the acrylic syrup described in . Next, the obtained glass fiber fabric 2 is placed on top of the curable resin composition which will become the first cured resin layer 3, and the glass fiber fabric 2 is left to stand for 1 minute, and the acrylic syrup is applied to the gap between the glass fiber fabric 2. It was impregnated with a curable resin composition consisting of: Next, the PET film used as the process film described above is placed on the curable resin composition made of the acrylic syrup, and a roller is applied from above the PET film to reduce the mass of the first cured resin layer 3 to 25 g/m ² Pressure was applied so that Thereafter, the curable resin composition made of acrylic syrup, which will become the first cured resin layer 3, is passed through the PET film in the above process and irradiated with light (light irradiation) using a black light fluorescent lamp (product name: FL15BLB, manufactured by Toshiba Corporation). Conditions: the curable resin composition was cured using an integrated light amount of 200 mJ/cm ² ) to form the first cured resin layer 3, and then the laminated process PET film was peeled off so that it would not be peeled off during use. Peelable cover layer / Acrylic acid ester adhesive peelable together with the cover layer / Antistatic layer / Film layer 5 (Cosmoshine (registered trademark) A4300) / Contained in a state impregnated in the glass fiber fabric 2 A laminate Y having a laminate structure of the first cured resin layer 3 was obtained. In the obtained laminate Y, the first cured resin layer 3 (cured product of the resin composition) made of acrylic syrup is impregnated into the gaps between the glass fibers of the glass fiber fabric 2 without exposing the glass fibers. It had been. Two pieces of the laminate Y were prepared.

(Lamination of second resin layer 4 included in glass fiber fabric 2 in an unimpregnated state)
The second resin layer 4 included in the glass fiber fabric 2 in an unimpregnated state is on the side of the first cured resin layer 3 included in the glass fiber fabric 2 in an impregnated state of the laminate Y obtained above. A brominated vinyl ester resin composition as shown in Table 1 was applied. Next, the other side of the obtained laminate Y is placed on top of the brominated vinyl ester resin composition so that the first cured resin layer 3 side of the laminate Y is the brominated vinyl ester resin composition. The second resin layer 4 made of the brominated vinyl ester resin composition was pressed from above with a roller so that the mass of the second resin layer 4 made of the brominated vinyl ester resin composition was 269 g/m ² . Thereafter, the brominated vinyl ester resin composition which is to be the second resin layer 4 is passed through the other laminate Y and irradiated with light (light irradiation) using a black light fluorescent lamp (product name: FL15BLB manufactured by Toshiba Corporation). Conditions: the brominated vinyl ester resin composition is cured using an integrated light amount of 200 mJ/cm ² ) to form the second resin layer 4, and a peelable cover layer that is peeled off during use/can be peeled off together with the cover layer. acrylic ester adhesive/antistatic layer/film layer 5 (Cosmoshine (registered trademark) A4300)/first cured resin layer 3 impregnated in glass fiber fabric 2/glass fiber fabric 2 Second resin layer 4 included in an unimpregnated state/First cured resin layer 3 included in an impregnated state in the glass fiber fabric 2/Film layer 5 (Cosmoshine (registered trademark) A4300)/Antistatic layer A transparent nonflammable sheet 1 of the present invention was obtained, which has a laminated structure of /an acrylic ester pressure-sensitive adhesive that can be peeled off together with the cover layer/a peelable cover layer that can be peeled off during use. Note that the evaluation of the bromine concentration, total light transmittance, haze, total calorific value, and time over 200 kW of the transparent noncombustible sheet described below is based on the removable cover that is peeled off when using the transparent noncombustible sheet 1 obtained above. The peelable acrylic ester adhesive was peeled off along with the layer and the cover layer.

In addition, in the examples, the weaving density of the glass fiber fabric was measured and calculated in accordance with 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 in accordance with JIS R 3420 2013 7.2. The refractive index of the glass fiber fabric 2, the first cured resin layer 3, and the second resin layer 4 was measured and calculated by the method described above. The Abbe numbers of the glass fiber fabric 2 and the first cured resin layer 3 were measured and calculated by the method described above. The following evaluations were made after the transparent nonflammable sheet 1 was left indoors for one week after it was produced.

Bromine concentration was measured and calculated using the method described above.

Total light transmittance, haze, and peeling of the transparent nonflammable sheet 1 after peeling off the removable cover layer (process film in Example 1, Reference Example 1, and Comparative Example 1) that is peeled off during use. After peeling off the possible cover layer, the transparent noncombustible sheet 1 was tested according to "4.10. 2. Total heat generation amount (MJ/m ² ) and heat generation rate of 200 kW/m in a heat generation test in which 50 kW/m ² of radiant heat is irradiated onto the surface of the sheet from a radiant electric heater, as measured in accordance with ``Exothermic Test/Evaluation Method.'' The time (S) exceeding ² was measured and calculated using the method described above. In addition, the presence or absence of through holes was determined for the sheet 20 minutes after the start of heating according to the above-mentioned "4.10.2 Heat generation test/evaluation method". Regarding the evaluation of color bleeding, the fluorescent lamps were looked at through each of the transparent nonflammable sheets, and the evaluation was made based on whether or not the color bleeding around the fluorescent lamps was noticeable. The evaluation criteria were as follows, using the sheet of Reference Example 1 as a reference sheet.
○: Same as Reference Example 1.
x: Color bleeding was more noticeable than in Reference Example 1.

The results of each evaluation are shown in Tables 1 and 2.

Example 1 is a transparent nonflammable sheet comprising a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric, and the cured resin layer contains an organic bromine monomer compound. The Abbe number of the cured resin layer is equivalent to the Abbe number of the sheet of Reference Example 1, and while increasing the nonflammability, the decrease in the Abbe number due to the inclusion of flame retardant components is suppressed, and the occurrence of color bleeding can be suppressed. It was. On the other hand, in Comparative Example 1, since the cured resin layer does not contain an organic bromine monomer compound but contains a brominated vinyl ester resin, the Abbe number is lower than that of the sheet of the reference example, and the suppression of color bleeding is inferior. Ta.

In Examples 2 to 5, in addition to being able to suppress the decrease in the Abbe number of the cured resin component other than the flame retardant component due to the flame retardant component while increasing the nonflammability, the resin was impregnated into the glass fiber fabric. a first cured resin layer and a second resin layer contained in the glass fiber fabric in an unimpregnated state, the second resin layer has a bromine concentration higher than the first resin layer, and the transparent Since the total light transmittance of the nonflammable sheet is 85% or more and the haze is 10% or less, it is possible to improve the transparency and lower the total calorific value when the resin weight is increased. This made it possible to achieve both.

In addition, since Examples 1 to 5 contain organic bromine monomer compounds, they are listed as "4. In a heat generation test in which the surface of the sheet is irradiated with 50kW/ ^m2 of radiant heat from a radiant electric heater, the first resin layer is less likely to swell, and the It was also less likely that cracks and holes penetrating the back surface, which are harmful in terms of fire protection, would occur for 20 minutes after the start of heating due to swelling.

1... Transparent nonflammable sheet 2... Glass fiber fabric 3... First cured resin layer 4... Second resin layer 5... Film layer

Claims (6)

A transparent nonflammable sheet comprising a glass fiber fabric and a cured resin layer impregnated with the glass fiber fabric,
The cured resin layer contains a curable acrylic resin and tetrabromobisphenol A ,
The difference between the Abbe number of the glass fiber fabric and the Abbe number of the cured resin layer is 23 or less,
Transparent nonflammable sheet. The transparent nonflammable sheet according to claim 1 , wherein the cured resin layer contains a cured resin that does not contain bromine in its skeleton. The transparent noncombustible sheet according to claim 1 , wherein the transparent noncombustible sheet has a total light transmittance of 85% or more and a haze of 10% or less. The transparent nonflammable sheet according to any one of claims 1 to 3 , wherein the cured resin layer has an Abbe number of 30 or more. A second resin layer is included in the thickness direction of the transparent noncombustible sheet, the second resin layer is included in the glass fiber fabric without being impregnated, and has a bromine concentration of 30% by mass or more. The transparent nonflammable sheet according to any one of claims 1 to 4 . Radiant electricity measured in accordance with "4.10.2 Heat generation test and evaluation method" in the "Fireproof performance test and evaluation work method manual" (revised version on March 1, 2014) of the Building Materials Testing Center, a general incorporated foundation. The transparent nonflammable sheet according to any one of claims 1 to 5 , which has a total calorific value of 8 MJ/m ² or less in a heat generation test in which radiant heat of 50 kW/m ² is irradiated onto the surface of the sheet from a heater.

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