Sheet

Abstract

To provide a cured resin layer contained in a glass fiber fabric while being impregnated into the glass fiber fabric which suppresses stickiness and is excellent in folding resistance.SOLUTION: A sheet includes a glass fiber fabric, and a cured resin layer which is contained in a glass fiber fabric while being impregnated into the glass fiber fabric, wherein the cured resin layer is formed of a cured product of a resin composition which contains (A) a brominated bisphenol A type vinyl ester resin, and (B) monofunctional (meth)acrylate that has an alkylene oxide group and has no aromatic ring.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a seat. [Background technology]

[0002] The Building Standards Act and its Enforcement Order stipulate that smoke exhaust systems must be installed to prevent the flow of smoke, toxic gases, etc. that are generated in the event of a fire in a building, and to facilitate evacuation and firefighting activities. Therefore, office buildings, commercial facilities, and other buildings often have smoke exhaust systems and smoke barriers such as vertical smoke barriers installed.

[0003] Hanging smoke barriers are usually attached to the ceilings of buildings to temporarily block the flow of smoke, toxic gases, etc. into corridors and upper floors in the event of a fire, thereby ensuring the time necessary for evacuation. For this reason, transparent plate glass, transparent resin composites of glass fiber and resin, etc. are used as hanging smoke barriers to prevent them from obstructing the view or spoiling the aesthetics. Transparent resin composites of glass fiber and resin have the advantage of being less likely to break than transparent plate glass.

[0004] Known examples of the transparent resin composite include a sheet including at least one glass fiber fabric and a pair of cured resin layers sandwiching the glass fiber fabric, wherein the glass fiber fabric accounts for 20 to 70% by weight, the pair of cured resin layers accounts for 80 to 30% by weight, the difference in refractive index between the glass composition constituting the glass fibers in the glass fiber fabric and the resin composition constituting the pair of cured resin layers is 0.02 or less, and the difference in Abbe number between the glass composition constituting the glass fibers in the glass fiber fabric and the resin composition constituting the pair of cured resin layers is 30 or less (see, for example, Patent Document 1).

[0005] Also known is a non-flammable sheet having at least one glass fiber fabric and a photo-curable resin impregnated into the glass fiber fabric, wherein the difference in refractive index between the glass composition constituting the glass fibers in the glass fiber fabric and the photo-curable resin is 0.02 or less, the proportion of the glass fiber fabric to the non-flammable sheet is 20 to 70% by weight, the proportion of the photo-curable resin to the non-flammable sheet is 80 to 30% by weight, and the photo-curable resin is obtained by curing a composition containing at least brominated bisphenol A vinyl ester (see, for example, Patent Document 2).

[0006] Also, 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 laminated laminate having a basis weight of 30 g / m 2 ~80g / m 2 A transparent noncombustible sheet having a thickness of 300 μm to 400 μm is known, which is composed of a laminate including a cured resin composition layer containing a cured resin composition containing 10% to 30% by mass of bromine impregnated into a glass fiber fabric, and a second polycarbonate sheet layer having a thickness of 100 μm to 150 μm and containing 5% to 20% by mass of bromine laminated on the cured resin composition layer (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2005-319746 A [Patent Document 2] Patent Publication No. 2014-213489 [Patent Document 3] Patent Publication No. 2020-1172 Summary of the Invention [Problem to be solved by the invention]

[0008] The present inventors have found that the sheet disclosed in Patent Document 1 may cause stickiness on the surface of the cured resin layer after curing. The inventors have found that if stickiness occurs, for example, when the sheet is made into a roll product, it may become difficult to pull out the sheet. Furthermore, the inventors have found that if a thermoplastic resin layer such as a film layer is laminated on the cured resin layer for the purpose of improving the tear strength of the sheet, the adhesiveness of the thermoplastic resin layer is likely to be poor.

[0009] The present inventors have also found that the non-combustible sheet disclosed in Patent Document 2 and the transparent non-combustible sheet disclosed in Patent Document 3 have a problem in that the cured resin layer impregnated in the glass fiber fabric may have poor folding resistance. Specifically, the inventors have found that when the sheet is repeatedly bent, it is prone to breakage, resulting in poor folding resistance.

[0010] Therefore, the main object of the present invention is to solve the above problems and to provide a cured resin layer impregnated in a glass fiber fabric that is less sticky and has excellent folding resistance. [Means for solving the problem]

[0011] The present inventors have investigated the above problem and found that, in Patent Document 1, only a so-called bisphenol A vinyl ester resin, made from a bisphenol A epoxy resin, is used as the curable resin for forming the cured resin layer. The inventors have found that when a bisphenol A vinyl ester resin is used alone as the curable resin for forming the cured resin layer, the curing reaction proceeds relatively slowly, and the surface of the cured resin layer may become sticky.

[0012] On the other hand, the present inventors have found that when a cured resin layer contains a so-called brominated bisphenol A vinyl ester resin, which is made from a brominated bisphenol A epoxy resin, among vinyl ester resins, the curing reaction proceeds relatively easily, and stickiness on the surface of the cured resin layer can be suppressed. However, the refractive index of the brominated bisphenol A vinyl ester resin is significantly higher than that of a glass fiber fabric. Therefore, simply impregnating a glass fiber fabric with the brominated bisphenol A vinyl ester resin will result in a sheet with poor transparency, as the refractive index of the glass fiber fabric and the cured resin layer will not be similar. Therefore, when a brominated bisphenol A vinyl ester resin is contained, it is necessary to also contain a material with a relatively low refractive index in the cured resin composition in order to make the refractive index of the cured resin layer similar to that of the glass fiber fabric.

[0013] In this regard, Patent Document 2 discloses the use of neopentyl glycol dimethacrylate, a bifunctional methacrylate, as a refractive index modifier for brominated bisphenol A vinyl ester resins. Patent Document 3 discloses the use of phenoxyethyl acrylate and 2-ethylhexyl acrylate. However, the present inventors have found that when these refractive index modifiers are contained in brominated bisphenol A vinyl ester resins, the folding endurance of the cured resin layer tends to deteriorate.

[0014] Therefore, the present inventors have conducted extensive research and found that the above problems can be solved by forming the cured resin layer from a cured product of a resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring. The present invention was completed based on this finding and through further extensive research.

[0015] That is, the present invention provides the following aspects of the invention. Item 1. A sheet comprising a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric, wherein the cured resin layer is formed from a cured product of a resin composition comprising (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring. Item 2. The sheet according to Item 1, wherein the number of moles of alkylene oxide groups added is 2 to 10. Item 3. The sheet according to Item 1 or 2, wherein a thermoplastic resin layer is laminated on the cured resin layer. Item 4. The sheet according to any one of items 1 to 3, wherein the sheet has a total light transmittance of 80% or more and a haze of 20% or less. Term 5.50kW / m 2 When subjected to a heat generation test in which radiant heat of 8 MJ / m was irradiated, the total heat generation amount for 20 minutes after the start of heating was 8 MJ / m. 2 5. The sheet according to claim 1, wherein: Item 6.50kW / m 2 When subjected to a heat generation test in which radiant heat is irradiated, the heat generation rate is 200 kW / m for 10 seconds or more continuously for 20 minutes after heating begins. 2 The sheet according to any one of items 1 to 5, wherein the thickness does not exceed 100 mm. [Effects of the Invention]

[0016] The sheet of the present invention comprises a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric, and the cured resin layer is formed from a cured product of a resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring, thereby reducing stickiness and providing excellent folding resistance. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view illustrating one embodiment of a sheet of the present invention. [Figure 2] 1 is a cross-sectional view illustrating one embodiment of a sheet of the present invention. [Figure 3] This is a diagram showing an outline of the test equipment used when conducting "4.9.2 Heat generation test" in the "Fire resistance performance test and evaluation procedure manual" (revised version as of July 1, 2021) of the Japan Testing Center for Construction Materials. [Figure 4] This is a schematic diagram of the test holder and clamping frame included in the testing equipment used when conducting "4.9.2 Heat Generation Test" in the "Fire Resistance Testing and Evaluation Procedures Manual" (revised July 1, 2021) of the Japan Testing Center for Construction Materials. The values ​​(dimensions) shown in Figure 4 are in mm. [Figure 5] FIG. 2 is a schematic plan view illustrating a method for measuring tear strength. DETAILED DESCRIPTION OF THE INVENTION

[0018] The sheet of the present invention comprises a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric, wherein the cured resin layer is formed from a cured product of a resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring.

[0019] For example, as shown in FIGS. 1 and 2, the sheet 1 of the present invention comprises a glass fiber fabric 2 and a cured resin layer 3 impregnated in the glass fiber fabric 2, and the cured resin layer 3 is formed from a cured product of a resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring.

[0020] The sheet 1 of the present invention may contain at least one glass fiber fabric 2, or may contain multiple glass fiber fabrics 2. As shown in Figures 1 and 2, in the sheet 1 of the present invention, the cured resin layer 3 fills the gaps between the glass fibers that make up the glass fiber fabric 2, and one surface side portion of the cured resin layer 3 communicates with the other surface side portion via the gaps. The sheet 1 of the present invention may also contain multiple cured resin layers 3. One cured resin layer 3 may also contain multiple glass fiber fabrics 2.

[0021] The sheet 1 of the present invention may have layers other than the cured resin layer 3. For example, as shown in FIG. 2, the sheet 1 of the present invention may include a thermoplastic resin layer 4. It is preferable that each thermoplastic resin layer 4 is included on the outer side of the cured resin layer 3. Furthermore, when the thermoplastic resin layer 4 is provided, another layer may be provided between the cured resin layer 3 and the thermoplastic resin layer 4, and such another layer may be, for example, an adhesive layer. Each layer constituting the sheet 1 of the present invention will be described in detail below.

[0022] [Glass fiber fabric 2] In the sheet 1 of the present invention, the glass fiber fabric 2 is impregnated with a cured resin layer 3, which will be described later. In the sheet 1 of the present invention, the glass fiber fabric 2 contributes to improving the flame retardancy of the sheet. The refractive index of the glass fiber fabric 2 can be set to be similar to the refractive index of the cured resin layer 3, which will be described later. This allows the sheet 1 of the present invention to have a total light transmittance of 80% or more and a haze of 20% or less, which are preferable indicators of transparency. In other words, the preferable transparency indicators of the sheet 1 of the present invention, namely, a total light transmittance of 80% or more and a haze of 20% or less, indicate that the refractive index of the glass fiber fabric 2 and the refractive index of the cured resin layer 3, which will be described later, are sufficiently similar (for example, the difference between the refractive index of the glass fiber fabric 2 and the refractive index of the cured resin layer 3 is 0.02 or less).

[0023] In the sheet 1 of the present invention, the weave of the glass fiber fabric 2 is not particularly limited, and examples thereof include plain weave, satin weave, twill weave, basket weave, and rib weave, with plain weave being preferred.

[0024] 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-elasticity glass (S glass, T glass, etc.), and alkali-resistant glass (AR glass), with the versatile alkali-free glass (E glass) being preferred. The glass fibers constituting the glass fiber fabric 2 may be made of one type of glass material or a combination of two or more types of glass fibers made of different glass materials. In addition, from the viewpoint of improving transparency, it is preferable to select a glass material whose refractive index is close to that of the cured resin layer 3 described below.

[0025] The count of the glass fibers constituting the glass fiber fabric 2 is not particularly limited as long as it can form the glass fiber fabric 2. From the viewpoint of further improving transparency, the count of the glass fibers is preferably 20 tex or less, more preferably 3 to 6 tex, and more preferably 3 to 5 tex. The count of the glass fibers may be one type alone or two or more types may be combined. The tex count of the glass fibers corresponds to the number of grams per 1000 m.

[0026] The glass fibers constituting the glass fiber fabric 2 are preferably glass yarns in which a plurality of single filaments, which are long glass fibers, are twisted together. The number of single filaments in the glass yarn is preferably about 30 to 400, and more preferably about 40 to 120. The diameter of the single filament in the glass yarn is preferably about 3.0 to 6.0 μm, and more preferably about 3.0 to 5.0 μm, from the viewpoint of further improving the transparency of the sheet 1 while improving the flame retardancy of the sheet 1. The count of the glass yarn is preferably 2 to 30 tex, more preferably 2 to 12 tex, and even more preferably 2 to 6 tex, from the viewpoint of further improving the transparency of the sheet 1 while improving the flame retardancy of the sheet 1.

[0027] In the sheet 1, the total mass of the glass fiber fabric 2 (g / m 2 ) and the total mass (g / m) of the cured resin layer 3 described later 2 , excluding glass fiber fabrics 2) and the total amount (g / m 2 The ratio (mass %) of the total mass of the glass fiber fabric 2 in the sheet 1 to the total mass (g / m) of the sheet 1 is preferably 20 to 60 mass %, more preferably 30 to 60 mass %, from the viewpoint of further improving both transparency and non-combustibility when the resin weight in the sheet is increased. 2 ) to the total mass (g / m 2 The proportion (% by mass) of ) is preferably 5 to 60% by mass, from the viewpoint of achieving a further improvement in both transparency and non-combustibility.

[0028] The difference in refractive index between the glass fiber fabric 2 and the cured resin layer 3 described below is preferably 0.02 or less, and more preferably 0.01 or less. The refractive index of the glass fiber fabric 2 is preferably about 1.50 to 1.58, and more preferably about 1.53 to 1.57.

[0029] The refractive index of the glass fiber fabric 2 is measured in accordance with Method B of the Japanese Industrial Standard JIS K 7142:2008. Specifically, the glass fibers constituting the glass fiber fabric are first crushed to a degree that allows the Becke lines to be observed when observed using an optical microscope at 400x magnification. Then, using a halogen lamp equipped with an interference filter for D-line as a light source, the optical microscope is used for observation and measurement at 400x magnification and a temperature of 23°C, and the average value of three tests is used as the refractive index. The refractive index of the cured resin layer 3 is measured in accordance with Method B of the Japanese Industrial Standard JIS K 7142:2008. Specifically, the cured resin layer 3 is crushed to a degree that allows the Becke lines to be observed when observed using an optical microscope at 400x magnification. Then, using a halogen lamp equipped with an interference filter for D-line as a light source, the optical microscope is used for observation and measurement at 400x magnification and a temperature of 23°C, and the average value of three tests is used as the refractive index.

[0030] The difference in Abbe number between the glass fiber fabric 2 and the 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, and even more preferably 50 to 65. The Abbe numbers of the cured resin layer 3 and the glass fiber fabric 2 are each measured as follows.

[0031] (Abbe number of cured resin layer 3) A sheet not containing glass fiber fabric 2 was prepared using the resin constituting cured resin layer 3, measuring 8 mm in width, 20 mm in length, and 1 mm in thickness, and measured in accordance with Japanese Industrial Standard JIS K 7142A using an Abbe refractometer (ATAGO Co., Ltd. DR-M2), diiodomethane as the contact liquid, and interference filters (D line (589 nm), F line (486 nm), and C line (656 nm)) at a measurement temperature of 23° C. The refractive indices for the D line, F line, and C line were measured, and the Abbe number was 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

[0032] (Abbe number of glass fiber fabric 2) A glass fiber was fabricated using the glass material constituting the glass fiber, measuring 8 mm in width, 20 mm in length, and 1 mm in thickness, and measured in accordance with Japanese Industrial Standard JIS K 7142A using an Atago Co., Ltd. DR-M2 Abbe refractometer, diiodomethane as the contact liquid, and interference filters for D line (589 nm), F line (486 nm), and C line (656 nm), at a measurement temperature of 23°C. The refractive indices for the D line, F line, and C line were measured, and the Abbe number was 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

[0033] The thickness of each sheet of the glass fiber fabric 2 is, for example, about 10 to 100 μm, preferably about 10 to 55 μm, and more preferably about 10 to 35 μm, from the viewpoint of improving the flame retardancy of the sheet 1 and further improving the transparency of the sheet 1. The thickness of each sheet of the glass fiber fabric 2 is a value measured in accordance with Method A specified in "7.10.1 Cloth Thickness" of the Japanese Industrial Standard JIS R3420:2013 "General Test Methods for Glass Fibers." The mass of each sheet of the glass fiber fabric 2 is, for example, 10 to 60 g / m 2 , preferably 25 to 50 g / m 2 , more preferably 25 to 35 g / m 2When the thickness of the glass fiber fabric 2 is set to 10 to 35 μm, it is particularly preferable that the glass fiber fabric 2 has a glass volume fraction of 38% or more as calculated by the following formula (II). A 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.

[0034] Glass volume ratio (%) = (A / (B × C)) × 100 (II) A: Mass of glass fiber fabric (g / m 2 ) B: Specific gravity of the glass material that makes up the glass fiber fabric (g / m 3 ) C: Thickness of the glass fiber fabric (m)

[0035] [Cured resin layer 3] The sheet of the present invention comprises a cured resin layer impregnated in a glass fiber fabric, and the cured resin layer is formed from a cured product of a resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring.

[0036] As described above, the present inventors have found that when (A) a brominated bisphenol A vinyl ester resin is incorporated into a cured resin layer, the curing reaction proceeds relatively easily, thereby suppressing stickiness on the surface of the cured resin layer. When (A) a brominated bisphenol A vinyl ester resin is incorporated, it is necessary to also incorporate a material with a relatively low refractive index into the cured resin composition so that the refractive index of the cured resin layer is similar to that of a glass fiber fabric. The present inventors have found that when the refractive index adjusters disclosed in Patent Documents 2 and 3 are used when (A) a brominated bisphenol A vinyl ester resin is incorporated, the resulting cured resin layer exhibits poor folding endurance. After extensive research, the present inventors have found that when (B) a monofunctional (meth)acrylate having an alkylene oxide group but no aromatic ring is incorporated as a refractive index adjuster when (A) a brominated bisphenol A vinyl ester resin is incorporated, the resulting cured resin layer exhibits excellent folding endurance.

[0037] The monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring is not particularly limited, and examples thereof include compounds represented by the following general formula (I):

[0038] R1-O-(R2O) n -R3···(I) (wherein R1 is an acryloyl group or a methacryloyl group, R2 is a divalent chain hydrocarbon group having 1 to 40 carbon atoms, R3 is a monovalent chain hydrocarbon group having 1 to 40 carbon atoms, and n is an integer of 2 to 50.)

[0039] In the compound represented by the general formula (I), R2 is preferably a divalent chain hydrocarbon group having 1 to 5 carbon atoms. R3 is preferably a monovalent chain hydrocarbon group having 1 to 5 carbon atoms. n is preferably 2 to 10. From the viewpoint of further improving the folding endurance of the sheet, the compound represented by the general formula (I) is preferably one in which R2 in the general formula (I) is a divalent chain hydrocarbon group having 1 to 5 carbon atoms, R3 is a monovalent chain hydrocarbon group having 1 to 5 carbon atoms, and n is 2 to 10. More preferably, R2 in the general formula (I) is a divalent chain hydrocarbon group having 1 to 5 carbon atoms, R3 is a monovalent chain hydrocarbon group having 1 to 5 carbon atoms, and n is 2 to 4 (i.e., the number of moles of alkylene oxide groups added is 2 to 4). From the viewpoint of more easily maintaining transparency even after the sheet is left in a high-temperature environment, n is preferably 3 to 10, more preferably 2 to 9. Furthermore, from the viewpoint of more easily achieving both better folding resistance of the sheet and easier maintenance of transparency even after the sheet is left in a high-temperature environment, the above n is preferably 3 to 4.

[0040] Examples of monofunctional (meth)acrylates having an alkylene oxide group and no aromatic ring include ethoxy-diethylene glycol acrylate, methoxy-triethylene glycol acrylate, 2-ethylhexyl-diglycol acrylate, and methoxy-polyethylene glycol acrylate.

[0041] The cured resin layer 3 can be formed from a cured product of a resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring, as well as other components. Examples of such other components include cured resins other than brominated bisphenol A vinyl ester resins. Examples of cured resins other than brominated bisphenol A vinyl ester resins include bisphenol A vinyl ester resins, novolac vinyl ester resins, urethane acrylate resins, fluorene acrylate resins, unsaturated polyester resins, curable acrylic resins, and epoxy resins. Bisphenol A vinyl ester resins are preferred because they facilitate improving the transparency of the sheet. These cured resins may be used alone or in combination of two or more.

[0042] The other components include a polymerization initiator for curing the curable resin. The type of polymerization initiator may be appropriately selected depending on the type of curable resin used. Examples of photopolymerization initiators include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-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- Examples of photopolymerization initiators include 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]-1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. Among these photopolymerization initiators, 1-hydroxy-cyclohexyl-phenyl-ketone is preferred from the viewpoint of improving the transparency of the sheet. These photopolymerization initiators may be used alone or in combination of two or more. The content of the polymerization initiator in the cured resin layer 3 may be 1 to 5 parts by mass per 100 parts by mass of the total amount of the cured resin layer 3.

[0043] In the cured resin layer 3, the proportion of the mass of the (A) brominated bisphenol A vinyl ester resin relative to the mass of the resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring (mass excluding the glass fiber fabric 2) is, for example, 20 to 60 mass%, preferably 35 to 55 mass%. Furthermore, in the cured resin layer 3, the proportion of the mass of the (B) monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring relative to the mass of the resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring (mass excluding the glass fiber fabric 2) is, for example, 5 to 45 mass%, preferably 10 to 40 mass%. In the cured resin layer 3, in the resin composition containing (A) a brominated bisphenol A type vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring, the ratio ((A) / (B)) of (A) the brominated bisphenol A type vinyl ester resin to (B) the monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring is, for example, 1 to 4, and preferably 1.5 to 2.0. Furthermore, in the cured resin layer 3, when the resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring further contains a cured resin other than the brominated bisphenol A vinyl ester resin, the proportion of the mass of the cured resin other than the brominated bisphenol A vinyl ester to the mass of the resin composition (mass excluding the glass fiber fabric 2) is 15 to 45 mass%, and preferably 20 to 40 mass%.

[0044] In the present invention, in order to enhance the transparency of the sheet, it is desirable to set the refractive indexes of the glass fiber fabric 2 and the cured resin layer 3 to be similar to each other. From this viewpoint, the refractive index of the cured resin layer 3 is preferably about 1.45 to 1.65, and more preferably about 1.50 to 1.60.

[0045] In the sheet of the present invention, the mass of each cured resin layer 3 (excluding the mass of the glass fiber fabric 2) is, for example, 10 to 100 g / m 2 In the sheet of the present invention, from the viewpoint of more suitably achieving both improved transparency and improved non-flammability, the mass of each cured resin layer 3 (mass excluding the glass fiber fabric 2) is preferably 20 to 60 g / m 2 , more preferably 20 to 50 g / m 2 The thickness of each cured resin layer 3 is, for example, 10 to 120 μm, and from the viewpoint of more suitably achieving both improved transparency and improved non-flammability, is preferably 20 to 100 μm, and more preferably 20 to 80 μm.

[0046] [Thermoplastic resin layer 4] In the sheet 1 of the present invention, a thermoplastic resin layer 4 is laminated on the cured resin layer 3 as needed to improve the weather resistance, tear strength, folding endurance, etc. of the sheet 1. It is preferable that one thermoplastic resin layer 4 is included on the outer side of the cured resin layer 3.

[0047] The material constituting the thermoplastic resin layer 4 is not particularly limited. Examples include polyester resin (including polyethylene terephthalate), polycarbonate resin, polyolefin resin, fluororesin, acrylic resin, polyamide resin, and polyvinyl chloride resin. Polyvinyl chloride resin is preferred from the viewpoint of achieving a good balance between flame retardancy and tear strength of the sheet. Furthermore, the thermoplastic resin layer 4 is preferably a film layer made of the above resin. Furthermore, an inorganic filler can be added to the thermoplastic resin layer 4. Examples of inorganic fillers include glass beads.

[0048] The thickness of each thermoplastic resin layer 4 is, for example, 50 to 200 μm, and from the viewpoint of achieving both flame retardancy and folding resistance, is preferably 60 to 150 μm, and more preferably 80 to 140 μm. The mass of each thermoplastic resin layer 4 is, for example, 60 to 280 g / m 2 From the viewpoint of achieving both non-combustibility and folding resistance, 70 to 200 g / m 2 is preferable, and 95 to 190 g / m 2 are more preferred.

[0049] When the thermoplastic resin layer 4 is laminated, another layer, for example, an adhesive layer, may be provided between the cured resin layer 3 and the thermoplastic resin layer 4. When an adhesive layer is provided, the mass of each adhesive layer is 3 to 20 g / m 2 and 5 to 15 g / m 2 are preferred.

[0050] [Sheet characteristics] The sheet 1 of the present invention preferably has high transparency to prevent obstruction of visibility or deterioration of aesthetics when used, for example, as a smoke barrier, partition, or light-receiving tent membrane. To ensure high transparency, the total light transmittance of the sheet 1 of the present invention is 80% or more, preferably 85% or more, and more preferably 90% or more. The haze of the sheet 1 of the present invention is, for example, 20% or less, preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less. In this specification, the total light transmittance of the sheet 1 is a value measured in accordance with Japanese Industrial Standard JIS K 7361-1:1997, "Test method for total light transmittance of plastic transparent materials - Part 1: Single beam method." The haze of the sheet 1 is a value measured in accordance with Japanese Industrial Standard JIS K7136 2000, "Determination of haze of plastic transparent materials."

[0051] The sheet of the present invention has a total light transmittance of 80% or more, preferably 85% or more, before and after being left in a high-temperature environment at a temperature of 40°C and a relative humidity of 65% for three days. The sheet of the present invention has a haze of 20% or less, preferably 10% or less, and more preferably 5% or less, before and after being left in a high-temperature environment at a temperature of 40°C and a relative humidity of 65% for three days. The total light transmittance and haze can be measured by the same measuring methods as those described above.

[0052] The sheet 1 of the present invention has the property of being flame-resistant (heat-resistant) in the event of a fire, since the cured resin layer 3 contains a brominated bisphenol A vinyl ester resin. As an index of this property of the sheet 1 of the present invention, a value of 50 kW / m 2 In a heat generation test in which radiant heat is irradiated, the total heat generation amount for 20 minutes after the start of heating is, for example, 8MJ / m 2 Less than 6MJ / m, preferably 2 Less than or equal to 5MJ / m 2 The following can be mentioned. In addition, other indexes of the properties possessed by the sheet 1 of the present invention include a thermal conductivity of 50 kW / m 2 In a heat generation test in which radiant heat is irradiated, the heat generation rate is 200 kW / m for 10 seconds or more continuously for 20 minutes after heating starts. 2 Preferably, the heat generation rate should not exceed 200 kW / m for 3 seconds or more for 20 minutes after the start of heating. 2 More preferably, the heat generation rate should not exceed 200 kW / m for 1 second or more for 20 minutes after the start of heating. 2 The main points are that it does not exceed 50kW / m 2 The total heat generation amount and heat generation rate per unit area in the heat generation test in which radiant heat is irradiated are values ​​determined in accordance with "4.9.2 Heat Generation Test" in the "Fire Resistance Performance Testing and Evaluation Procedure Manual" (revised July 1, 2021) of the Japan Testing Center for Building Materials. In order to make it easier for the sheet of the present invention to have the above properties, the mass of the cured resin layer 3, the mass of the thermoplastic resin layer 4, etc. can be adjusted.

[0053] In the sheet 1 of the present invention, the cured resin layer impregnated in the glass fiber fabric preferably has a folding endurance of 30,000 or more times, and more preferably 35,000 or more times. The folding endurance is measured as follows: Using an MIT folding endurance tester, the number of times a test piece is folded back and forth until it breaks is measured under a load of 1 kg, with a bending angle of 135° and a bending speed of 175±10 times / min. Each sheet measures 15 mm × 110 mm. The number of foldings is measured in accordance with the method specified in JIS R 3420:2013, "General Test Methods for Glass Fibers," section 7.14, "Folding Endurance of Cloth." Measurements are performed in both the warp and weft directions of the glass fiber fabric, and the average number of foldings in the warp direction and the weft direction is used to evaluate the folding endurance. (= (Number of foldings in the warp direction + Number of foldings in the weft direction) / 2)

[0054] In the sheet 1 of the present invention, the tear strength of the cured resin layer impregnated into the glass fiber fabric is preferably 1 N or greater, more preferably 1 to 3 N. The tear strength is measured in accordance with Japanese Industrial Standard JIS R 3420:2013, Section 7.16, Method C (trapezoid method), by conducting a tensile test using a constant-rate load tensile tester under conditions of a grip distance of 25 mm and a tensile speed of 200 mm / min. Specifically, 75 mm x 150 mm test pieces are taken from the sheet 1 in the warp direction and the weft direction of the glass fiber fabric, respectively. An isosceles trapezoid with a short side of 25 mm, a long side of 100 mm, and a height of 75 mm is marked on the test piece as shown in the figure. Anti-slip tape (product name "600S" manufactured by Sekisui Chemical Co., Ltd.) is applied to both the front and back of the area outside the isosceles trapezoid (i.e., the two trapezoidal portions including a right angle; corresponding to trapezoid portion A shown in Figure 2). A 10 mm cut was also made at right angles to the center of the short side of the isosceles trapezoid mark. Using a constant-rate load tensile tester (product name "RTC-1310A," manufactured by Orientec Co., Ltd.), the test specimen was clamped with the short side of the isosceles trapezoid tensile tensioned and the long side of the isosceles trapezoid loosened, with the test specimen gripped at a 25 mm interval. A tensile test was performed at a tensile speed of 200 mm / min, and the maximum load exhibited when the specimen was torn was measured. The maximum load in the warp direction and the maximum load in the weft direction of the glass fiber fabric were measured, and the average of the maximum load in the warp direction and the maximum load in the weft direction of the glass fiber fabric (= (maximum load in the warp direction of the glass fiber fabric (N) + maximum load in the weft direction (N)) / 2) was calculated as the tear strength (N).

[0055] The mass of the sheet 1 of the present invention is not particularly limited, but from the viewpoint of more suitably imparting the property of being hard to burn (hard to generate heat) in the event of a fire and excellent folding endurance, the mass of the sheet 1 of the present invention is preferably 30 to 450 g / m 2 , more preferably 40 to 430 g / m 2 In particular, when the sheet 1 of the present invention has a thermoplastic resin layer 4, the mass is preferably 200 to 450 g / m 2 , more preferably 250 to 430 g / m 2 Examples include:

[0056] The thickness of the sheet 1 of the present invention is not particularly limited, but from the viewpoint of more suitably imparting the properties of being flame-resistant (heat-resistant) in the event of a fire and excellent folding endurance, the thickness of the sheet 1 of the present invention is preferably 30 to 400 μm, more preferably 40 to 350 μm. In particular, when the sheet 1 of the present invention has a thermoplastic resin layer 4, the thickness is preferably 150 to 400 μm, more preferably 200 to 350 μm.

[0057] When the sheet 1 of the present invention comprises a thermoplastic resin layer 4, the ratio of the thickness of each cured resin layer 3 to the thickness of the sheet 1 (thickness of cured resin layer 3 / thickness of sheet 1) is, from the viewpoint of more suitably imparting the properties of being less flammable (less likely to generate heat) in the event of a fire and excellent folding endurance, for example, 0.01 to 0.8, preferably 0.03 to 0.3, and more preferably 0.05 to 0.25.

[0058] (Method of manufacturing sheet 1 of the present invention) The method for producing the sheet 1 of the present invention is not particularly limited. For example, first, the resin composition constituting the glass fiber fabric 2 and the cured resin layer 3 is prepared. Next, the resin composition is applied to the glass fiber fabric 2 to impregnate it, and then 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, applying light energy, or the like, to obtain a sheet 1 in which the glass fiber fabric 2 is impregnated with the cured resin layer 3. Alternatively, a processing film such as polyethylene terephthalate to which the resin composition is applied is prepared, and the film is pressed onto both sides of the glass fiber fabric 2 to impregnate both sides of the glass fiber fabric 2 with the resin composition. After the resin composition is cured, the processing film is peeled off to obtain a sheet 1 in which the glass fiber fabric 2 is impregnated with the cured resin layer 3.

[0059] When the resin composition is cured by applying thermal energy, the heating temperature is not particularly limited and can be, for example, about 50 to 200°C. When the resin composition is cured by applying light energy, the resin composition is cured by irradiating it with light. The light irradiation conditions include, for example, an integrated light dose of 100 to 500 mJ / cm. 2 It can be said that:

[0060] When the sheet 1 of the present invention has a thermoplastic resin layer 4, the thermoplastic resin layer 4 can be laminated on the cured resin layer 3 obtained above. [Example]

[0061] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0062] 1. Measurement and evaluation methods 1-1. Average diameter (μm) and number of single fibers of glass yarn Two pieces of glass fiber fabric were cut into 30 cm squares, one for observing the warp yarns and the other for observing the weft yarns, and each was embedded in epoxy resin (product name "3091", manufactured by Marumoto Struers K.K.) and cured. Next, the glass cloth embedded in the epoxy resin was polished to an extent that the cross section of the single fibers constituting the warp or weft yarns could be observed, and the average single fiber diameter (μm) and the number of single fibers (number of fibers) of the glass yarn were measured by observing them at a magnification of 500 times using a scanning electron microscope (SEM) (product name "JSM-6390A", manufactured by JEOL Ltd.). (1) Average single fiber diameter of long glass fibers (μm) Twenty warp and weft yarns were randomly selected, and the cross sections of all the single fibers contained in each of the 20 glass yarns were observed, the diameters were measured, and the average value was calculated to obtain the average single fiber diameter of the warp and weft yarns. (2) Number of single fibers (pieces) Twenty warp and weft yarns were randomly selected, and the total number of single fibers contained in each of the 20 glass yarns was measured and the average value was calculated to determine the number of single fibers in the warp and weft yarns.

[0063] 1-2.Glass yarn count The count of the glass yarn was measured according to the method specified in "7.1 Count" of the Japanese Industrial Standard JIS R 3420 2013 "General Test Methods for Glass Fibers." Specifically, 500 m of glass yarn was first taken from the winding machine and used as a test piece. The test piece was placed flat in a muffle furnace and baked at 625°C for 25 minutes, then allowed to cool in a desiccator, and the mass of the test piece was measured. The count was calculated according to the following formula: t=(m / 500)×1000 t: count m: mass of test piece (g)

[0064] 1-3.Glass fiber fabric 2 weave density (threads / 25mm) The weave density of the glass fiber fabric 2 was measured for the warp and weft threads in accordance with the method specified in "7.9 Density (Weave Density)" of the Japanese Industrial Standard JIS R 3420:2013 "General Test Methods for Glass Fibers." Specifically, the measurement targets were positions 50 mm or more away from the edges and selvages of the glass fiber fabric 2, with the measurement interval set to 10 mm or more and 200 mm or less, and the total number of threads within the set measurement interval was counted. This was counted as one measurement, and the measurement was then moved to another position that did not include the previously measured thread, and the total number of threads within the measurement interval was counted two more times in the same manner. For each of the three measurements, the number of threads per 25 mm was calculated using the following formula, and the average of the three measurements was calculated. Mi=(ni / ai)×25 Mi: Number of threads per 25mm ni: Number of measured yarns ai: the exact distance at which the measurement was taken (mm)

[0065] 1-4. Thickness of glass fiber fabric 2 (μm) The thickness of the glass fiber fabric 2 was measured in accordance with Method A specified in "7.10.1 Cloth Thickness" of the Japanese Industrial Standard JIS R3420:2013 "General Test Methods for Glass Fibers." Specifically, using a micrometer, the spindle was gently rotated to lightly contact the measurement surface parallel to it, and the thickness of the glass fiber fabric 2 was measured by reading the scale after the ratchet made three clicks. The thickness of the glass fiber fabric 2 was measured at the intersection of the warp and weft threads.

[0066] 1-5. Refractive index of the glass fiber fabric 2 and the cured resin layer 3 The refractive indices of the glass fiber fabric 2 and the cured resin layer 3 were measured in accordance with "Method B" specified in Japanese Industrial Standard JIS K 7142:2008, "Plastics - Determination of Refractive Index." Specifically, the glass fibers constituting the glass fiber fabric 2 and the cured resin layer 3 were first crushed to an extent that Becke lines could be observed when observed under an optical microscope at 400x magnification, and used as measurement samples. Separately, multiple immersion solutions with refractive indices differing by 0.002 were prepared. A small amount of the immersion solution was placed on a glass slide, and several particles of the measurement sample were placed in the immersion solution on the glass slide, followed by a cover glass. A halogen lamp equipped with a D-line interference filter was used as the light source, and the measurement sample was focused on using an optical microscope at 400x magnification. The microscope stage and objective lens were then moved slightly apart to defocus the image. By this procedure, if the refractive index of the measurement sample does not match that of the immersion liquid, the Becke lines (i.e., the bright halo visible around or inside the powder) will shift to the higher refractive index, and if the refractive index of the measurement sample matches that of the immersion liquid, the Becke lines will not appear. The refractive index was measured by repeating the measurement until the refractive index of the measurement sample matches that of the immersion liquid or falls between two adjacent refractive indices in the series of immersion liquids. The refractive index was measured three times at a temperature of 23°C, and the average of the three measurements was taken as the refractive index.

[0067] 1-6. Mass of glass fiber fabric 2 (g / m 2 ) The mass of the glass fiber fabric 2 was measured in accordance with the method specified in "7.2 Mass (mass) of cloths and mats" of the Japanese Industrial Standard JIS R 3420:2013 "General test methods for glass fibers." Specifically, a 100 cm2 area was measured from a point 50 mm or more away from the edge of the glass fiber fabric 2. 2 A square test piece was taken, dried at 105°C for 1 hour, and then the mass of the test piece was measured and calculated as 1m according to the following formula: 2 The mass per unit was calculated. ρA=(ms / 100)×10 4 ρA:1m 2 Mass per unit (g / m 2 ) ms: mass of test piece (g)

[0068] 1-7. Total light transmittance (%) and haze (%) immediately after manufacturing, and total light transmittance (%) and haze (%) after being left in a high-temperature environment after manufacturing The total light transmittance of Sheet 1 was measured in accordance with Japanese Industrial Standard JIS K 7361-1:1997 "Test method for total light transmittance of plastics - transparent materials - Part 1: Single beam method." The haze of Sheet 1 was measured in accordance with Japanese Industrial Standard JIS K 7136:2000 "Determination of haze of plastics - transparent materials." The total light transmittance and haze of Sheet 1 were measured immediately after production, and then the sheet was left in a high-temperature environment of 40°C and 65% relative humidity for 3 days, after which the measurement was repeated.

[0069] 1-8. Total heat generation in heat generation test (MJ / m 2 ), and a heat generation rate per unit area of ​​200 kW / m 2 Exceeded duration (seconds) Sheet 1: 50kW / m 2 The total heat generation amount in the heat generation test in which radiant heat is irradiated is 200kW / m and the heat generation rate per unit area is 200kW / m 2 The overheat duration was measured in accordance with "4.9.2 Heat Generation Test" in the "Fire Prevention and Evaluation Procedures Manual" (revised July 1, 2021) of the Japan Testing Center for Construction Materials. The specific method is as follows: The total heat generation in the heat generation test was 8MJ / m 2 Pass the following (〇), heat generation rate per unit area 200kW / m 2The excess duration is 20 minutes after the start of heating, and the heat generation rate continues for 10 seconds or more and exceeds 200 kW / m 2 Those that did not exceed this were considered to be passing (〇).

[0070] [Test specimen] (1) The number of test specimens (sheet 1) shall be three. (2) The shape and dimensions of the test specimen shall be a square with each side measuring 99 mm ± 1 mm. (3) Before the test, the test specimen is cured at a temperature of 23°C ± 2°C and a relative humidity of 50% ± 5% until it reaches a constant mass. [Test equipment] (1) A schematic diagram of the test equipment used is shown in Figure 3. The test equipment consists of a conical radiant electric heater, a spark plug, a radiant heat shield, a test specimen holder, a gas sampling device, an exhaust system capable of measuring gas flow rate, and a heat flow meter. (2) Radiant electric heater: 50 kW / m 2 The radiant heat must be able to be irradiated uniformly and stably onto the surface of the test piece. (3) The radiant heat shield must be capable of protecting the test specimen from radiant heat before the test begins. (4) A schematic diagram of the test holder and clamping frame included in the test equipment is shown in Figure 4. The specimen holder shall be made of stainless steel and be a square with outer dimensions of 106 mm ± 1 mm on each side, 25 mm ± 1 mm in depth, and 2.4 mm ± 0.15 mm in thickness. The clamping frame shall be made of stainless steel and be a square with inner dimensions of 111 mm ± 1 mm on each side, 54 mm ± 1 mm in height, and 1.9 mm ± 0.1 mm in thickness, with a square opening at the top measuring 94.0 mm ± 0.5 mm on each side. (5) The exhaust system shall be equipped with a centrifugal exhaust fan, hood, fan intake and exhaust ducts, an orifice plate flow meter, etc. that function effectively at the test temperature. The distance between the bottom end of the hood and the surface of the test specimen shall be 210 mm ± 50 mm, and the exhaust device of the exhaust system in this state shall have a flow rate of 0.024 m / s when converted to standard temperature and standard pressure. 3The exhaust gas flow rate shall be at least 1 / s. To measure the exhaust gas flow rate, an orifice plate with an inner diameter of 57 mm ± 3 mm and a thickness of 1.6 mm ± 0.3 mm shall be installed in the exhaust duct at a position at least 350 mm ± 15 mm downstream from the fan. For exhaust gas sampling, a ring sampler with 12 holes, each 2.2 mm ± 0.1 mm in diameter, shall be installed 685 mm ± 15 mm from the hood, with the holes facing in the opposite direction to the flow. The exhaust gas temperature shall be measured at the center of the exhaust duct, 100 mm ± 5 mm upstream from the orifice plate. (6) The gas sampling device shall be capable of continuously and accurately measuring the concentrations of oxygen, carbon monoxide, and carbon dioxide in the exhaust gas. (7) The spark plug shall be capable of receiving power from a 10kV transformer or induction coil system, etc. The distance between the electrodes of the spark plug shall be 3mm ± 0.5mm, and the electrodes shall be positioned 13mm ± 2mm above the central axis of the test specimen, in principle. (8) The heat flow meter is 100kW / m 2 ±10kW / m 2 The heat flow meter is a Schmidt-Boelter type that can measure up to 12.5 mm in diameter. The heat sensing part of the heat flow meter is circular and has a surface emissivity of 0.95±0.05.

[0071] [Test conditions] (1) The test time shall be 20 minutes from the time when radiant heat is irradiated onto the surface of the test specimen and an electric spark is simultaneously generated. (2) The test specimen is wrapped on the sides and back with aluminum foil of 0.025 mm or more and 0.04 mm or less in thickness, placed in a press frame, and then coated with inorganic fiber (nominal density 64 to 128 kg / m) on the back side. 3 ) and then pressed into the specimen holder. (3) During the test, a radiant electric heater was applied to the surface of the test specimen at 50 kW / m 2 It emits radiant heat. (4) Exhaust gas flow rate: 0.024 m 3 Adjust to / s. (5) Until the test begins, the test specimen is protected from radiant heat by a radiant heat shield. (6) Before moving the radiation heat shield, set the spark plug in place.

[0072] [measurement] (1) Measure the oxygen concentration at intervals of no more than 5 seconds. (2) The heat generation rate per unit area (kW / m 2 ) and the heat generation rate per unit area is calculated as 200 kW / m 2 The duration of the superheat state is calculated as "heat generation rate per unit area 200 kW / m 2 Furthermore, the total heat generation rate per unit area (MJ / m) was calculated by trapezoidal integration of the heat generation rate per unit area with respect to time. 2 Here, trapezoidal integration is performed by dividing the integration interval equally over the measurement interval, with negative heat release rates set to 0, and integrating only positive heat release rates.

number

number

number

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[0073] 1-9. Resistance to deformation during fire For sheet 1, the total calorific value (MJ / m) in the heat generation test described above in "1-8. 2 ), and a heat generation rate per unit area of ​​200 kW / m 2 The heat generation test shown in the "Excessive duration (seconds)" column was conducted, and the condition of the test specimen was observed after 20 minutes of radiant heat irradiation, and the "resistance to deformation in the event of a fire" was evaluated according to the following criteria. <Evaluation criteria for resistance to deformation during fire> A: After 20 minutes of radiant heat irradiation, the deformation of the specimen was suppressed and the specimen was contained within the holding frame. B: After 20 minutes of radiant heat irradiation, the specimen was deformed and did not fit within the clamping frame.

[0074] 1-10.Folding resistance Using an MIT folding endurance tester, the number of times the test piece was folded back and forth until it broke was measured under a load of 1 kg, a bending angle of 135°, and a bending speed of 175±10 times / min. Each sheet measured 15 mm x 110 mm. The number of times the test piece was folded back and forth was measured in accordance with the method specified in 7.14 "Folding endurance of cloth" of the Japanese Industrial Standard JIS R 3420:2013 "General test methods for glass fibers." The number of times the test piece was folded back and forth was measured in both the warp and weft directions of the glass fiber fabric, and the average number of times the test piece was folded back and forth in the warp direction and the weft direction (= (number of times the test piece was folded back and forth in the warp direction + number of times the test piece was folded back and forth in the weft direction) / 2) was used to evaluate the test piece.

[0075] 1-11. Evaluation of stickiness The obtained sheet was wound around a paper tube under a fixed tension for 5 turns, and left to stand for 20 hours in an environment of 20°C temperature and 65% relative humidity, after which it was rewound. When rewinding, if there was any feeling of resistance due to adhesion between the wound sheets, it was evaluated as failing (×), and if there was any feeling of resistance when rewinding and it could be rewound smoothly, it was evaluated as passing (◯).

[0076] 1-12.Tear strength (N) The tear strength of Sheet 1 was measured in accordance with Japanese Industrial Standard JIS R 3420:2013, Section 7.16, Method C (trapezoid method) using a constant-rate load tensile tester with a grip spacing of 25 mm and a tensile speed of 200 mm / min. Specifically, 75 mm x 150 mm test pieces were taken from Sheet 1 in the warp direction and weft direction of the glass fiber fabric, respectively. An isosceles trapezoid mark with a short side of 25 mm, a long side of 100 mm, and a height of 75 mm was made on the test piece as shown in the figure. Anti-slip tape (product name "600S" manufactured by Sekisui Chemical Co., Ltd.) was applied to both the front and back of the area outside the isosceles trapezoid (i.e., the two trapezoidal portions including a right angle; corresponding to trapezoid portion A shown in Figure 2). A 10 mm slit was made in the center of the short side of the isosceles trapezoid mark, perpendicular to the side. Using a constant-rate load tensile tester (product name "RTC-1310A", manufactured by Orientec Co., Ltd.), the test specimen was clamped with the short sides of the isosceles trapezoid tensile tensioned and the long sides of the isosceles trapezoid loosened, with the test specimen gripped at a distance of 25 mm, and a tensile test was performed at a tensile speed of 200 mm / min to measure the maximum load exhibited when the specimen was torn. The maximum load in the warp direction and the maximum load in the weft direction of the glass fiber fabric were measured, and the average value of the maximum load in the warp direction and the maximum load in the weft direction of the glass fiber fabric (= (maximum load in the warp direction of the glass fiber fabric (N) + maximum load in the weft direction (N)) / 2) was calculated as the tear strength (N).

[0077] Example 1 (Preparation of glass fiber fabric 2) Glass yarns (trade name "ECC1200 1 / 0 1.0Z", manufactured by Unitika Glass Fiber Co., Ltd.; average single fiber diameter 4.5 μm, single fiber count 100, twist count 1.0Z, count 4.2 tex) were used as warp and weft yarns. These were woven on an air jet loom to obtain a plain weave glass fiber fabric with a warp density of 90 / 25 mm and a weft density of 90 / 25 mm. The spinning and weaving sizing agents adhering to the resulting glass fiber fabric were then removed by heating at 400°C for 30 hours. The glass fiber fabric was then treated with a surface treatment agent containing a silane coupling agent (S-350: N-vinylbenzyl-aminoethyl-γ-aminopropyltrimethoxysilane (hydrochloride), manufactured by Chisso Corporation) adjusted to a concentration of 15 g / L, squeezed with a padder roll, and then dried at 120°C for 1 minute for curing. The glass fiber fabric was then subjected to a water jet processing at a pressure of 1.5 MPa, with the warp tension of the fabric set to 100 N / m, and a width-widening treatment was carried out once to obtain a glass fiber fabric 2 (glass fiber fabric). The obtained glass fiber fabric 2 had a warp density of 90 threads / 25 mm, a weft density of 90 threads / 25 mm, a thickness of 30 μm, and a mass of 30 g / m 2 The refractive index was 1.561. The average single fiber diameter and the number of single fibers of the glass yarn were measured using the glass fiber fabric 2.

[0078] (Preparation of Resin Composition Solution Used to Form Cured Resin Layer 3) As the resin composition solution to be used to form the cured resin layer 3, brominated bisphenol A type vinyl ester (product name "Neopor 8197", manufactured by Japan U-Pica Co., Ltd.), bisphenol A type vinyl ester resin (product name "Neopor 8126", manufactured by Japan U-Pica Co., Ltd.), methoxytriethylene glycol acrylate (product name "Light Acrylate MTG-A", manufactured by Kyoeisha Chemical Co., Ltd.), and photopolymerization initiator (product name "Omnirad 184", manufactured by IGM) were prepared and mixed to the mass ratio shown in Table 1 to prepare a resin composition solution.

[0079] (Preparing the process film) As a processing film, a PET film (thickness 75 μm, total light transmittance (JIS K7361-1 1997) 93%, haze (JIS K7136 2000) 4%) was prepared. Two sheets of the processing film were prepared.

[0080] A sheet was produced using the prepared glass fiber fabric 2, resin composition solution, and cast film. Specifically, the resin composition solution was first applied to one side of one cast film and one side of another cast film. Then, the glass fiber fabric 2 was sandwiched between the two cast films coated with the resin composition solution so that the side coated with the resin composition solution faced the glass fiber fabric 2, and pressure was applied with a roller so that the mass of the cured resin layer 3 satisfied the value listed in Table 1, impregnating both sides of the glass fiber fabric 2 with the resin composition solution. Thereafter, with the cast film still laminated, the resin composition solution was irradiated with light (light irradiation conditions: cumulative light dose 200 mJ / cm) using a black light fluorescent lamp (product name "FL15BLB", manufactured by Toshiba Corporation). 2 ) to cure the resin composition solution, forming a cured resin layer 3, and the process film was peeled off to obtain a sheet having the laminated structure illustrated in FIG. 1 , which includes a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric.

[0081] <Example 2> (Preparation of glass fiber fabric 2) The same glass fiber fabric 2 as in Example 1 was prepared.

[0082] (Preparation of Resin Composition Solution Used to Form Cured Resin Layer 3) As the resin composition solution to be used to form the cured resin layer 3, brominated bisphenol A type vinyl ester (product name "Neopor 8197", manufactured by Japan U-Pica Co., Ltd.), bisphenol A type vinyl ester resin (product name "Neopor 8126", manufactured by Japan U-Pica Co., Ltd.), ethoxy-diethylene glycol acrylate (product name "Light Acrylate EC-A", manufactured by Kyoeisha Chemical Co., Ltd.), and photopolymerization initiator (product name "Omnirad 184", manufactured by IGM) were prepared and mixed to the mass ratio shown in Table 1 to prepare a resin composition solution.

[0083] (Preparing the process film) As a processing film, a PET film (thickness 75 μm, total light transmittance (JIS K7361-1 1997) 93%, haze (JIS K7136 2000) 4%) was prepared. Two sheets of the processing film were prepared.

[0084] A sheet was produced using the prepared glass fiber fabric 2, resin composition solution, and cast film. Specifically, the resin composition solution was first applied to one side of one cast film and one side of another cast film. Then, the glass fiber fabric 2 was sandwiched between the two cast films coated with the resin composition solution so that the side coated with the resin composition solution faced the glass fiber fabric 2, and pressure was applied with a roller so that the mass of the cured resin layer 3 satisfied the value listed in Table 1, impregnating both sides of the glass fiber fabric 2 with the resin composition solution. Thereafter, with the cast film still laminated, the resin composition solution was irradiated with light (light irradiation conditions: cumulative light dose 200 mJ / cm) using a black light fluorescent lamp (product name "FL15BLB", manufactured by Toshiba Corporation). 2 ) to cure the resin composition solution, forming a cured resin layer 3, and the process film was peeled off to obtain a sheet having the laminated structure illustrated in FIG. 1 , which includes a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric.

[0085] Example 3 (Preparation of glass fiber fabric 2) The same glass fiber fabric 2 as in Example 1 was prepared.

[0086] (Preparation of Resin Composition Solution Used to Form Cured Resin Layer 3) As the resin composition solution to be used to form the cured resin layer 3, brominated bisphenol A type vinyl ester (product name "Neopor 8197", manufactured by Japan U-Pica Co., Ltd.), bisphenol A type vinyl ester resin (product name "Neopor 8126", manufactured by Japan U-Pica Co., Ltd.), methoxy-polyethylene glycol acrylate (n=9) (product name "Light Acrylate 130A", manufactured by Kyoeisha Chemical Co., Ltd.), and photopolymerization initiator (product name "Omnirad 184", manufactured by IGM) were prepared and mixed to the mass ratio shown in Table 1 to prepare a resin composition solution.

[0087] (Preparing the process film) As a processing film, a PET film (thickness 75 μm, total light transmittance (JIS K7361-1 1997) 93%, haze (JIS K7136 2000) 4%) was prepared. Two sheets of the processing film were prepared.

[0088] A sheet was produced using the prepared glass fiber fabric 2, resin composition solution, and cast film. Specifically, the resin composition solution was first applied to one side of one cast film and one side of another cast film. Then, the glass fiber fabric 2 was sandwiched between the two cast films coated with the resin composition solution so that the side coated with the resin composition solution faced the glass fiber fabric 2, and pressure was applied with a roller so that the mass of the cured resin layer 3 satisfied the value listed in Table 1, impregnating both sides of the glass fiber fabric 2 with the resin composition solution. Thereafter, with the cast film still laminated, the resin composition solution was irradiated with light (light irradiation conditions: cumulative light dose 200 mJ / cm) using a black light fluorescent lamp (product name "FL15BLB", manufactured by Toshiba Corporation). 2 ) to cure the resin composition solution, forming a cured resin layer 3, and the process film was peeled off to obtain a sheet having the laminated structure illustrated in FIG. 1 , which includes a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric.

[0089] <Comparative Example 1> (Preparation of glass fiber fabric 2) The same glass fiber fabric 2 as in Example 1 was prepared.

[0090] (Preparation of Resin Composition Solution Used to Form Cured Resin Layer 3) As the resin composition solution to be used to form the cured resin layer 3, brominated bisphenol A vinyl ester (product name "Neopor 8197", manufactured by Japan U-Pica Co., Ltd.), bisphenol A vinyl ester resin (product name "Neopor 8126", manufactured by Japan U-Pica Co., Ltd.), 2-hydroxyethyl acrylate (product name "Light Ester HOA(N)", manufactured by Kyoeisha Chemical Co., Ltd.), and photopolymerization initiator (product name "Omnirad 184", manufactured by IGM) were prepared and mixed to the mass ratio shown in Table 1 to prepare a resin composition solution.

[0091] (Preparing the process film) As a processing film, a PET film (thickness 75 μm, total light transmittance (JIS K7361-1 1997) 93%, haze (JIS K7136 2000) 4%) was prepared. Two sheets of the processing film were prepared.

[0092] A sheet was produced using the prepared glass fiber fabric 2, resin composition solution, and cast film. Specifically, the resin composition solution was first applied to one side of one cast film and one side of another cast film. Then, the glass fiber fabric 2 was sandwiched between the two cast films coated with the resin composition solution so that the side coated with the resin composition solution faced the glass fiber fabric 2, and pressure was applied with a roller so that the mass of the cured resin layer 3 satisfied the value listed in Table 1, impregnating both sides of the glass fiber fabric 2 with the resin composition solution. Thereafter, with the cast film still laminated, the resin composition solution was irradiated with light (light irradiation conditions: cumulative light dose 200 mJ / cm) using a black light fluorescent lamp (product name "FL15BLB", manufactured by Toshiba Corporation). 2 ) to cure the resin composition solution, forming a cured resin layer 3, and the process film was peeled off to obtain a sheet having the laminated structure illustrated in FIG. 1 , which includes a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric.

[0093] <Comparative Example 2> (Preparation of glass fiber fabric 2) The same glass fiber fabric 2 as in Example 1 was prepared.

[0094] (Preparation of Resin Composition Solution Used to Form Cured Resin Layer 3) As the resin composition solution to be used for forming the cured resin layer 3, bisphenol A type vinyl ester resin (product name "Neopol 8126", manufactured by Japan U-Pica Co., Ltd.) was prepared and mixed to obtain the mass ratio shown in Table 1 to prepare a resin composition solution.

[0095] (Preparing the process film) As a processing film, a PET film (thickness 75 μm, total light transmittance (JIS K7361-1 1997) 93%, haze (JIS K7136 2000) 4%) was prepared. Two sheets of the processing film were prepared.

[0096] A sheet was produced using the prepared glass fiber fabric 2, resin composition solution, and cast film. Specifically, the resin composition solution was first applied to one side of one cast film and one side of another cast film. Then, the glass fiber fabric 2 was sandwiched between the two cast films coated with the resin composition solution so that the side coated with the resin composition solution faced the glass fiber fabric 2, and pressure was applied with a roller so that the mass of the cured resin layer 3 satisfied the value listed in Table 1, impregnating both sides of the glass fiber fabric 2 with the resin composition solution. Thereafter, with the cast film still laminated, the resin composition solution was irradiated with light (light irradiation conditions: cumulative light dose 200 mJ / cm) using a black light fluorescent lamp (product name "FL15BLB", manufactured by Toshiba Corporation). 2 ) to cure the resin composition solution, forming a cured resin layer 3, and the process film was peeled off to obtain a sheet having the laminated structure illustrated in FIG. 1 , which includes a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric.

[0097] <Comparative Example 3> (Preparation of glass fiber fabric 2) The same glass fiber fabric 2 as in Example 1 was prepared.

[0098] (Preparation of Resin Composition Solution Used to Form Cured Resin Layer 3) As the resin composition solution to be used to form the cured resin layer 3, brominated bisphenol A type vinyl ester (product name "Neopol 8197", manufactured by Japan U-Pica Co., Ltd.), bisphenol A type vinyl ester resin (product name "Neopol 8126", manufactured by Japan U-Pica Co., Ltd.), neopentyl glycol diacrylate (product name "NK Ester A-NPG", manufactured by Shin-Nakamura Chemical Co., Ltd.), and photopolymerization initiator (product name "Omnirad 184", manufactured by IGM) were prepared and mixed to the mass ratio shown in Table 1 to prepare a resin composition solution.

[0099] (Preparing the process film) As a processing film, a PET film (thickness 75 μm, total light transmittance (JIS K7361-1 1997) 93%, haze (JIS K7136 2000) 4%) was prepared. Two sheets of the processing film were prepared.

[0100] A sheet was produced using the prepared glass fiber fabric 2, resin composition solution, and cast film. Specifically, the resin composition solution was first applied to one side of one cast film and one side of another cast film. Then, the glass fiber fabric 2 was sandwiched between the two cast films coated with the resin composition solution so that the side coated with the resin composition solution faced the glass fiber fabric 2, and pressure was applied with a roller so that the mass of the cured resin layer 3 satisfied the value listed in Table 1, impregnating both sides of the glass fiber fabric 2 with the resin composition solution. Thereafter, with the cast film still laminated, the resin composition solution was irradiated with light (light irradiation conditions: cumulative light dose 200 mJ / cm) using a black light fluorescent lamp (product name "FL15BLB", manufactured by Toshiba Corporation). 2 ) to cure the resin composition solution, forming a cured resin layer 3, and the process film was peeled off to obtain a sheet having the laminated structure illustrated in FIG. 1 , which includes a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric.

[0101] <Comparative Example 4> (Preparation of glass fiber fabric 2) The same glass fiber fabric 2 as in Example 1 was prepared.

[0102] (Preparation of Resin Composition Solution Used to Form Cured Resin Layer 3) As the resin composition solution to be used to form the cured resin layer 3, brominated bisphenol A type vinyl ester (product name "Neopol 8197", manufactured by Japan U-Pica Co., Ltd.), bisphenol A type vinyl ester resin (product name "Neopol 8126", manufactured by Japan U-Pica Co., Ltd.), 3-phenoxybenzyl acrylate (product name "Light Acrylate POB-A", manufactured by Shin-Nakamura Chemical Co., Ltd.), and photopolymerization initiator (product name "Omnirad 184", manufactured by IGM) were prepared and mixed to the mass ratio shown in Table 1 to prepare a resin composition solution.

[0103] (Preparing the process film) As a processing film, a PET film (thickness 75 μm, total light transmittance (JIS K7361-1 1997) 93%, haze (JIS K7136 2000) 4%) was prepared. Two sheets of the processing film were prepared.

[0104] A non-flammable sheet was produced using the prepared glass fiber fabric 2, resin composition solution, and casting film. Specifically, the resin composition solution was first applied to one side of one casting film and one side of another casting film. Then, the glass fiber fabric 2 was sandwiched between the two casting films coated with the resin composition solution so that the side coated with the resin composition solution faced the glass fiber fabric 2, and pressure was applied with a roller so that the mass of the cured resin layer 3 satisfied the value listed in Table 1, thereby impregnating both sides of the glass fiber fabric 2 with the resin composition solution. Thereafter, with the casting film still laminated, the resin composition solution was irradiated with light (light irradiation conditions: cumulative light dose 200 mJ / cm) using a black light fluorescent lamp (product name "FL15BLB", manufactured by Toshiba Corporation). 2 ) to cure the resin composition solution, forming a cured resin layer 3, and the process film was peeled off to obtain a non-flammable sheet having the laminated structure illustrated in FIG. 1 , which includes a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric.

[0105] The results are shown in Table 1.

[0106] [Table 1]

[0107] The sheets of Examples 1 to 3 were sheets comprising a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric, and the cured resin layer was formed from a cured product of a resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring, and therefore had reduced stickiness and excellent folding resistance.

[0108] Among these, the sheets of Examples 1 and 2 had even better folding endurance because the number of moles of alkylene oxide groups added in (B) the monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring was 2 to 4. Also, the sheets of Examples 1 and 3 had a higher tendency to maintain transparency even after being left in a high-temperature environment because the number of moles of alkylene oxide groups added in (B) the monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring was 3 to 10. In particular, the sheet of Example 1 had a higher tendency to maintain both better folding endurance and transparency even after being left in a high-temperature environment because the number of moles of alkylene oxide groups added in (B) the monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring was 3 to 4.

[0109] On the other hand, the sheet of Comparative Example 1 had poor folding resistance because the 2-hydroxyethyl acrylate did not have an alkylene oxide group and did not contain (B) a monofunctional (meth)acrylate that had an alkylene oxide group and no aromatic ring.

[0110] Furthermore, the sheet of Comparative Example 2 did not contain brominated bisphenol A vinyl ester, and therefore was unable to suppress stickiness.

[0111] In addition, the sheet of Comparative Example 3 had poor folding resistance because the neopentyl glycol diacrylate was polyfunctional and did not contain (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring.

[0112] In addition, the sheet of Comparative Example 4 had poor folding resistance because the 3-phenoxybenzyl acrylate had an aromatic ring and did not contain (B) a monofunctional (meth)acrylate that had an alkylene oxide group but no aromatic ring.

Claims

1. A sheet comprising a glass fiber fabric and a cured resin layer impregnated in the glass fiber fabric, The sheet, wherein the cured resin layer is formed from a cured product of a resin composition containing (A) a brominated bisphenol A vinyl ester resin and (B) a monofunctional (meth)acrylate having an alkylene oxide group and no aromatic ring.

2. 2. The sheet according to claim 1, wherein the number of moles of alkylene oxide groups added is 2 to 10.

3. The sheet according to claim 1 or 2, wherein a thermoplastic resin layer is laminated on the cured resin layer.

4. 3. The sheet according to claim 1, wherein the sheet has a total light transmittance of 80% or more and a haze of 20% or less.

5. 50kW / m ２ When subjected to a heat generation test in which radiant heat of 8 MJ / m was irradiated, the total heat generation amount for 20 minutes after the start of heating was 8 MJ / m ２ 3. A sheet according to claim 1 or 2, wherein:

6. 50kW / m ２ When subjected to a heat generation test in which radiant heat of 200 kW / m was irradiated, the heat generation rate was 200 kW / m for 10 seconds or more continuously for 20 minutes after the start of heating. ２ 3. The sheet according to claim 1 or 2, wherein the thickness of said sheet is not more than 100 μm.

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