JP6035549B2 - Light diffusion incombustible sheet and method for producing the same - Google Patents

Description

  The present invention relates to a non-combustible sheet excellent in light diffusibility for uniformly diffusing light from a light source for illumination, and having improved antifouling properties and welder weldability, and a method for producing the same.

  In lighting devices such as surface lighting devices and internally illuminated signboards, it is generally required that the light emitting surface has sufficiently high luminance and that the luminance distribution is sufficiently uniform over the entire light emitting surface. As such a light emitting surface, a light diffusion sheet that diffuses light from a light source is used.

  As a material used for the light diffusion sheet, for example, a resin sheet such as an acrylic resin sheet, or frosted glass is generally used. Furthermore, a glass fiber sheet using a glass fiber fabric as a base fabric is also used.

  In addition, there is a tendency to increase demand for non-flammable resin sheets with light diffusibility to prevent burnout due to fires such as flameproof banners and membrane ceilings, or malfunctions of equipment, damage such as earthquakes, and injury due to scattering. There is.

  Therefore, recently, as a non-combustible sheet imparted with light diffusibility, a product in which a glass fiber fabric is impregnated and cured, or a glass fiber fabric is laminated with a flameproof resin sheet is commercially available. However, these sheets have problems such as insufficient welder welding, very poor workability and handleability, and dirt permeating and accumulating during long-term use.

  By the way, in order to increase light diffusibility, addition of particles (Patent Document 1), a method using a difference in refractive index between a glass fiber fabric and a curable resin (Patent Document 2), or a glass fiber fabric and a curable resin Although a method such as a method of mixing minute bubbles at the interface of the above (Patent Document 3) is disclosed, the total light transmittance decreases as the light diffusibility increases, and as a film material for illumination Is limited and not optimal. In addition, a method for optimizing the light diffusibility and the total light transmittance by adjusting the air permeability of the fiber and adjusting the draw ratio is also disclosed, but minute fluctuations at the stage of weaving the fiber are greatly involved in the performance, It is difficult to commercialize.

  On the other hand, a method has been proposed in which microscopic unevenness of a polyethylene terephthalate (hereinafter sometimes referred to as PET) film is used to provide unevenness on the outermost layer surface of a curable resin impregnated into a glass fiber fabric (Patent Document 4). ), It is possible to optimize the light diffusibility and the total light transmittance, but there are problems such as contamination easily embedded on the surface and poor high-frequency welder fusion. Further, in order to improve these problems, when other resins are coated or laminated, the unevenness is buried, and there is a problem that the light diffusibility is greatly deteriorated.

  Furthermore, there is also a disclosure of a method of impregnating and curing a glass fiber fabric with a fluorine-based resin or a silicon-based resin in order to improve durability, light resistance, and stain resistance (Patent Document 5), but the high-frequency welder fusion property is poor. In other words, no method has been found that satisfies both the light diffusibility and the total light transmittance and simultaneously satisfies the antifouling property and the welder weldability.

JP 2010-137582 A JP 2010-52370 A JP 2007-131654 A JP 2005-345873 A JP 2001-31235 A

  Glass fiber fabric is impregnated and cured, and flameproof resin is used for lighting devices such as surface lighting devices, internally illuminated signboards, light transmissive screens for projectors or televisions, internally illuminated light film ceilings, etc. The non-combustible sheet having the light diffusibility obtained by laminating the sheets has the above-mentioned problems, and the present invention provides a non-combustible sheet that greatly improves not only the light diffusibility but also the antifouling property and the welder weldability.

That is, in the present invention, a glass fiber fabric is embedded in the cured resin layer, and a thermoplastic resin layer is laminated on at least one surface of the cured resin layer with or without an adhesive layer. It is a light diffusing non-combustible sheet which is formed by laminating an ethylene-vinyl alcohol copolymer resin layer with or without an adhesive layer on the outer surface of a thermoplastic resin layer and satisfies the following (a) to (c): .
(A): The ethylene-vinyl alcohol copolymer resin layer is formed of a transparent ethylene-vinyl alcohol copolymer resin and an opaque ethylene-vinyl alcohol copolymer resin. (B): Total light transmission Rate is 80% or more (c): Haze is 60% or more

  In addition, the present invention relates to a transparent solution containing an ethylene-vinyl alcohol copolymer and having a solution temperature of 30 ° C. to 75 ° C., and the transparent solution or another ethylene-vinyl alcohol. A transparent solution containing the copolymer is mixed with an opaque solution obtained by cooling to 20 ° C. or lower to obtain a mixed solution having a solution temperature of 20 ° C. to 50 ° C. Heat treatment at 150 ° C. to form an ethylene-vinyl alcohol copolymer resin layer composed of a transparent ethylene-vinyl alcohol copolymer resin and an opaque ethylene-vinyl alcohol copolymer resin. It is a manufacturing method of a light diffusion incombustible sheet.

  The light-diffusing non-combustible sheet of the present invention has light diffusibility and non-combustibility, and in addition to improved secondary workability such as cutting and welding and handling at the time of installation, dirt wiping property and long-term use It has a feature that is excellent in preventing the adhesion of dirt.

FIG. 1 is a schematic cross-sectional view of an embodiment of the light diffusion incombustible sheet of the present invention. FIG. 2 is a schematic cross-sectional view of a laminate obtained as an intermediate product during the production of the light diffusing incombustible sheet (Example 1) of the present invention. FIG. 3 is a schematic cross-sectional view of a laminated sheet obtained as an intermediate product during the production of the light diffusing incombustible sheet (Example 1) of the present invention. FIG. 4 is a schematic cross-sectional view of an embodiment of the light diffusion incombustible sheet (Example 1) of the present invention.

  In the present invention, a glass fiber fabric is embedded in a cured resin layer, and a thermoplastic resin layer is laminated on at least one surface of the cured resin layer with or without an adhesive layer. It is a light diffusion incombustible sheet in which an ethylene-vinyl alcohol copolymer resin layer is laminated on the outer surface of a resin layer with or without an adhesive layer.

  FIG. 1 is a schematic cross-sectional view of an embodiment of the light diffusion incombustible sheet of the present invention. The light diffusion incombustible sheet includes a glass fiber cloth 3 and a cured resin layer 5 in which the glass fiber cloth is embedded. The cured resin layer 5 preferably fills the gaps in the glass fiber fabric 3 and is at least partially continuous. A thermoplastic resin layer 9 is provided on at least one surface of the cured resin layer 5, and an ethylene-vinyl alcohol copolymer (hereinafter referred to as EVOH) is provided on the outer layer of the thermoplastic resin layer 9 opposite to the cured resin layer 5. The resin layer 14 is formed. A thermoplastic resin layer 9 may be provided between the cured resin layer 5 and the EVOH resin layer 14 for the purpose of improving the flexibility and workability of the light diffusing incombustible sheet, and further improving the peel resistance. For the purpose, an adhesive-1 layer 8 is formed between the cured resin layer 5 and the thermoplastic resin layer 9, or an adhesive-2 layer 13 is formed between the EVOH resin layer 14 and the thermoplastic resin layer 9. Or you may. Only the thermoplastic resin layer 9 or the EVOH resin layer 14 may be formed on the outer layer of the cured resin layer 5 opposite to the thermoplastic resin layer 9, and the lamination of the thermoplastic resin layer 9 and the EVOH resin layer 14. A structure may be formed. Adhesive-1 layer 8 and adhesive-2 layer 13 may be present on the opposite outer layer as necessary.

  The shape of the glass fiber fabric 3 constituting the present invention is not particularly limited to a shape such as a woven fabric, a knitted fabric, a non-woven fabric, and paper, but is a woven fabric from the viewpoint that it is easy to ensure the transparency of the sheet of the present invention. Preferably there is.

  In the glass fiber fabric, a plurality of warps 1 and a plurality of wefts 2 are combined. Glass fiber fabric refers to a fabric woven using glass fibers for warp and weft. Glass fiber fabrics are sometimes called glass cloths.

  Examples of the weave structure of the glass fiber fabric include plain weave, satin weave, twill weave, oblique weave, and weave. When used as a building material, plain weave, oblique weave and woven weave are preferred.

  The gap between adjacent warps 1 in the glass fiber fabric is preferably 0.5 mm or less, and more preferably 0.2 mm or less. Moreover, it is preferable that the clearance gap between the adjacent wefts 2 in a glass fiber fabric is 0.5 mm or less, and it is more preferable that it is 0.2 mm or less. Satisfying the above-mentioned gap is preferable from the viewpoint of ensuring that the flame does not easily pass through the glass fiber fabric and ensures nonflammability.

  Glass fibers in the glass fiber fabric 3 include general-purpose non-alkali glass fibers (E glass), acid-resistant alkali-containing glass fibers (C glass), and high-strength / high-modulus glass fibers (S glass, T glass, etc.) Alkali-resistant glass fiber (AR glass) and the like can be mentioned, but use of alkali-free glass fiber having high versatility is preferable.

  The filament diameter of the glass fiber is preferably 1 to 20 μm from the viewpoint of achieving both strength properties and workability of the glass fiber fabric, and more preferably 3 to 12 μm. Further, the count of the glass fiber is preferably 5 tex to 70 tex, more preferably 10 tex to 35 tex. The tex count of glass fiber corresponds to the number of grams per 1000 m.

  The glass fiber fabric may be woven with one type of glass fiber, or may be woven with two or more types of glass fibers. For example, the warp and the weft may be separate glass fibers. When woven with two or more types of glass fibers, the glass fiber filament diameters and counts may be the same or different. For example, the glass fiber composition may be the same, and the glass fiber diameter and count may be different.

  The glass fiber fabric 3 may be subjected to a surface treatment with a silane coupling agent usually used as a glass fiber treatment agent for the purpose of improving the transparency and the bending whitening resistance of the light diffusion incombustible sheet of the present invention. preferable. Thereby, the glass fiber fabric 3 and the curable resin 4 can be bonded satisfactorily. As the silane coupling agent, an acrylic silane coupling agent, a styrene silane coupling agent, a vinyl silane coupling agent, an amine silane coupling agent and the like are preferable, and an acrylic silane coupling agent and a styrene silane are preferable. A coupling agent is more preferable.

The mass of the glass fiber fabric 3 per 1 m ² in the light diffusion incombustible sheet of the present invention, that is, the basis weight of the glass fiber fabric 3 is preferably ²⁰ to 150 g / m ² . If the basis weight of the glass fiber fabric 3 is more than 150 g / m ^2, the impregnation rate of the uncured resin 4 becomes slow, lowered workability, it may cause impregnation defects in the case of less than 20 g / m ² May cause problems with nonflammability, and each is not preferred. Note that if increasing the basis weight of the glass fiber cloth 3 in the light diffusing incombustible sheet than 150 g / m ^2, it is preferable to use two or more glass fiber cloth 3.

  The cured resin layer 5 may be composed of a curable resin that is cured by heat, or may be composed of a curable resin that is cured by irradiation with light such as ultraviolet rays. The curable resin 4 is preferably composed of a vinyl ester resin, an unsaturated polyester resin, an epoxy resin, or the like. Among them, the heat resistance, chemical resistance, mechanical strength, and curing characteristics are excellent. More preferably, it is made of a vinyl ester resin.

  The curable resin 4 may contain additives such as a flame retardant, an ultraviolet absorber, a filler, and an antistatic agent. Examples of the flame retardant include aluminum hydroxide, magnesium hydroxide, trichloroethyl phosphate, triallyl phosphate, ammonium polyphosphate, and phosphate ester. Examples of the ultraviolet absorber include benzotriazole. Examples of the filler include calcium carbonate, silica, and talc. Examples of the antistatic agent include surfactants.

  These additives may be in a particle shape, and in the case of a particle shape, the particle diameter is preferably 10 μm or less from the viewpoint of improving the total light transmittance of the obtained sheet, and is preferably 5 μm or less. Further preferred.

Light diffusing incombustible sheet of the present invention preferably has a basis weight of the cured resin layer 5 is in the range of 15~500g / ^{m 2,} and more preferably in the range of 50 to 300 g / ^{m 2.} When the basis weight of the cured resin layer 5 is less than 15 g / m ² , the glass fiber fabric 3 cannot be sufficiently packed, and the pattern of the glass fiber fabric 3 may be raised, and the transparency is high. Decreasing and not preferable. On the other hand, when the basis weight of the cured resin layer 5 is more than 500 g / m ² , the nonflammability is lowered, which is not preferable.

In the light diffusing incombustible sheet of the present invention, the mass ratio of the glass fiber constituting the glass fiber fabric 3 to the curable resin constituting the cured resin layer 5 is preferably 20:80 to 70:30. When the mass ratio of the glass fibers is less than 20, the amount of the cured resin layer 5 increases, and the nonflammability decreases, which is not preferable. On the other hand, when the mass ratio of the glass fibers exceeds 70, the thickness of the cured resin layer 5 becomes thin and the pattern of the glass fiber fabric 3 may be raised, which is not preferable because the transparency is lowered.
In addition, in the exothermic test based on the evaluation method of the Building Standard Act described later, in order to suppress damage such as deformation, melting and cracking, further improve nonflammability, and to achieve a level that passes the nonflammability certification, The mass ratio between the fiber and the curable resin is more preferably 30:70 to 70:30.

  In the light diffusion incombustible sheet of the present invention, the difference in refractive index between the glass composition constituting the glass fiber in the glass fiber fabric 3 and the curable resin 4 constituting the cured resin layer 5 is 0.02 or less. Preferably, the smaller the difference in refractive index between the two, the better the transparency of the sheet.

  The thermoplastic resin that forms the thermoplastic resin layer 9 constituting the light diffusing incombustible sheet of the present invention is not particularly limited, but polyolefins such as polyethylene, polypropylene, polynorbornene; polystyrene; polyvinyl chloride; acrylic resin Methacrylic resin; fluororesin such as polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin), ethylene-tetrafluoroethylene copolymer, perfluoroethylene-propene copolymer, polymethyl Examples thereof include polyesters such as methacrylate (PMMA); polyamides such as aliphatic polyamides and aromatic polyamides. Among these, polyvinyl chloride is more preferable in terms of cost and performance.

  Among polyvinyl chloride resins, vinyl chloride polymers, vinyl chloride / vinyl acetate copolymers, vinyl chloride / acrylic ester copolymers, and vinyl chloride / vinylidene chloride copolymers are economical and workable. It is preferable at a point and these may be used independently and may mix and use two or more types.

  The thermoplastic resin layer 9 may contain components other than the thermoplastic resin, and a plasticizer is preferably contained in order to ensure the flexibility of the obtained sheet.

  When the thermoplastic resin layer 9 is made of a polyvinyl chloride resin, the amount of the plasticizer added to the polyvinyl chloride resin is preferably 30 to 150 parts by mass with respect to 100 parts by mass of the polyvinyl chloride resin. It is more preferable that it is 35-120 mass parts. If it is less than 30 parts by mass, it will be excessively hard and will not be able to follow movement such as bending, and cracks will easily occur. On the other hand, if it exceeds 150 parts by mass, the strength of the resin is lowered, the strength of the heat-sealed part becomes insufficient, and the plasticizer may cause problems such as contamination of the film material.

  There are no particular restrictions on the plasticizer that can be used for the polyvinyl chloride resin, but dibutyl phthalate, diethyl phthalate, dihebutyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, di-phthalate as the phthalate ester plasticizer. Nonyl phthalate, di-n-decyl phthalate, diisodecyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, etc. are used, and adipic acid is 2-methyl-1,8-octanediol, 1,2 as a polyester plasticizer. -Products esterified with one or more of glycols such as propanediol, 1,3-butanediol, 2-ethylhexanol, and n-octanol can be used. Further, as a trimellitic acid plasticizer, , Tri-2-ethylhexyltri Relate, and the like can be used triisodecyl trimellitate rate, other plasticizers, pyromellitic acid plasticizers such as 2-ethylhexyl pyromellitate rate can also be used. As the polymer having a plasticizing action, an ethylene-vinyl acetate copolymer and / or a polymer obtained by introducing carbon monoxide into an ethylene-acrylic acid ester copolymer can be used. Such a polymer includes Elvalloy 742 (trademark) manufactured by Mitsui DuPont Chemical.

  The flame retardant for the polyvinyl chloride resin is preferably 3 to 150 parts by mass, more preferably 5 to 120 parts by mass with respect to 100 parts by mass of the polyvinyl chloride resin. When the blending amount of the flame retardant is less than 3 parts by mass, the flame resistance of the polyvinyl chloride resin layer becomes insufficient, and when a corn calorimeter test based on ISO 5660 and Part 1 is performed, Pinholes are likely to occur, which is not preferable. On the other hand, when the amount exceeds 150 parts by mass, the flexibility and the resin strength of the polyvinyl chloride resin layer are lowered, and the peel strength from the cured resin layer 5 and the EVOH resin layer 14 may be lowered.

As the flame retardant used for the polyvinyl chloride resin, an inorganic flame retardant is preferable because high flame retardancy can be secured. Among them, a combined flame retardant in which an antimony compound and a molybdenum compound are used in combination is used. Antimony compounds impart high flame retardancy to polyvinyl chloride resins and have a strong effect of preventing the spread of flames. Molybdenum compounds reduce combustion heat, reduce smoke generation, reduce harmful combustion gases, and promote carbonization. And it has the effect | action which suppresses generation | occurrence | production of the pinhole in a base fabric, and is used preferably.
Examples of the antimony compound include antimony trioxide and antimony pentoxide.
Examples of the molybdate compound include calcium zinc molybdate, potassium molybdate, sodium molybdate, calcium molybdate carbonate, and ammonium molybdate.
The inorganic flame retardant used in the present invention may be subjected to a silane coupling treatment in advance to improve adhesion with the resin.

Further, as flame retardants other than the above, the total calorific value and the rate of heat generation when the film material is burned do not exceed the standard value of ISO 5660 Part 1, for example, bromo flame retardant, phosphate ester, halogenated phosphate ester, chlorination Flame retardants can be used in addition to paraffin.
Decabromodiphenyl ether, pentabromomethylbenzene, hexabromobenzene and the like can be used as the bromide flameproofing agent.
As the phosphate ester, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate and the like can be used.

  Furthermore, for polyvinyl chloride resin layers, stabilizers such as calcium / zinc-based, barium / zinc-based, cadmium / barium-based, lead-based, organic tin laurate-based, organic tin mercaptite-based, and epoxy-based stabilizers Can be used alone or in admixture of two or more. The blending amount of the stabilizer is preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the polyvinyl chloride resin.

The basis weight of the thermoplastic resin layer 9 is preferable in order to achieve both the transparency and strength characteristics of a sheet obtained in the range of 60 to 400 g / m ² .

  In the light diffusion incombustible sheet of the present invention, it is important that the EVOH resin layer 14 is laminated to impart antifouling property to the light diffusion incombustible sheet and to ensure the fusion workability between the light diffusion incombustible sheets. . The ratio of the EVOH resin in the EVOH resin layer 14 is preferably 50% by mass or more. If the proportion of EVOH resin is less than 50% by mass, the light diffusing incombustible sheet obtained is not sufficient in light transmittance, antifouling property cannot be ensured, and tackiness is great, which hinders workability during secondary processing. It has some problems and is not preferred.

  The EVOH resin used in the EVOH resin layer 14 constituting the light diffusing incombustible sheet of the present invention has an ethylene content of 20 to 55 mol%, particularly 25 to 50 mol%, particularly a vinyl acetate component in terms of water resistance and strength. A saponified ethylene-vinyl acetate copolymer having a saponification degree of 90 mol% or more, particularly 95 mol% or more (that is, EVOH) having an intrinsic viscosity in the range of 0.7 to 1.5 dL / g is particularly preferable. When the ethylene content is less than 20 mol%, the water resistance under high humidity is inferior, and when the ethylene content exceeds 55 mol%, the antifouling property is insufficient, which is not preferable. Moreover, when the saponification degree of a vinyl acetate component is less than 90 mol%, there exists a problem inferior to solvent resistance, and it is unpreferable. Further, if the intrinsic viscosity is less than 0.7 dL / g, the mechanical strength is insufficient, and those having an intrinsic viscosity exceeding 1.5 dL / g are not practical because of difficulty in production. Here, the intrinsic viscosity is a value measured at a temperature of 30 ° C. in a mixed solvent of water / phenol having a mass ratio of 15/85.

  EVOH is obtained by saponification of an ethylene-vinyl acetate copolymer. The ethylene-vinyl acetate copolymer should be produced by any known polymerization method, for example, solution polymerization, suspension polymerization, emulsion polymerization, etc. The saponification of the ethylene-vinyl acetate copolymer can also be performed by a known method.

  Further, within the range not impairing the gist of the present invention, the α-olefin, the unsaturated carboxylic acid compound, the unsaturated sulfonic acid compound, (meth) if the EVOH resin constituting the EVOH layer is less than 50% by mass. EVOH resins copolymerized and modified with other comonomers such as acrylonitrile, (meth) acrylamide, vinyl ether, vinyl silane compound, vinyl chloride, styrene etc. can be used, and post-modified EVOH such as urethanization, acetalization, cyanoethylation, etc. A resin may be used.

  The EVOH resin constituting the EVOH resin layer 14 is characterized by being composed of a transparent EVOH resin and an opaque EVOH resin. The mass ratio of the transparent EVOH resin to the opaque EVOH resin in the EVOH resin layer 14 is preferably 10:90 to 90:10, and more preferably 30:70 to 85:15. When the mass ratio of the transparent EVOH resin is less than 10, the total light transmittance of the EVOH resin layer is undesirably lowered. On the other hand, if the mass ratio of the transparent EVOH resin exceeds 90, the light diffusibility of the EVOH resin layer is not sufficient, which is not preferable. When the mass ratio of the transparent EVOH resin and the opaque EVOH resin is within the above range, the total light transmittance is excellent, the haze is high, the light diffusibility is excellent, and the heat processability is easy. Thus, it becomes possible to provide a light-diffusing incombustible sheet having a feature of excellent antifouling property.

That is, the EVOH resin constituting the EVOH resin layer 14 is made of two or more types of EVOH resins, and the opaque EVOH resin is preferably made of a gelled EVOH resin.
For example, for (a) a transparent EVOH resin, a water / alcohol ratio of 20/80 to 80/20 is adjusted to 60 ° C. to 75 ° C., and EVOH is added to completely dissolve EVOH. An EVOH solution (referred to as “solution a”) is prepared and held at a solution temperature of 30 ° C. to 75 ° C. (B) For an opaque, preferably gelled EVOH resin, the solvent in the range of 20/80 to 80/20 in water / alcohol ratio is adjusted to 60 ° C. to 75 ° C., and then the EVOH is completely dissolved. Then, the EVOH solution is cooled to a temperature of 20 ° C. or lower while stirring at high speed to prepare an EVOH solution gelled into fine particles (this is referred to as “solution b”), and 5 In order to maintain the quality of the gel, it is preferable to maintain the solution at a temperature of 50 ° C to 50 ° C. The more preferable solution temperature of the “solution b” at the time of holding is 5 ° C. to 25 ° C.
Then, the transparent “solution a” and the opaque “solution b” are mixed so that the temperature of the mixed solution after mixing is 20 ° C. or higher, preferably 25 ° C. or higher, whereby the EVOH resin is transparent. And in the form of a resin having both opaque parts. In mixing, it is preferable to vigorously stir with a homogenizer or the like so that “solution a” and “solution b” are uniformly mixed.
At this time, the mixing ratio of “solution a” and “solution b” is preferably in the range of 10/90 to 90/10 in terms of mass ratio. More preferably, it is 30 / 70-80 / 20. When the mass ratio of “solution a” is less than 10, there is a problem in that the light diffusing incombustible sheet obtained is inferior in light transmittance and the strength characteristics of the EVOH resin layer are inferior. On the other hand, when the mass ratio of the “solution a” exceeds 90, the haze of the obtained light diffusion incombustible sheet is low, which is not preferable because the sheet is inferior in light diffusion.

  Although a mixed solution can be obtained as described above, a transparent EVOH resin and an opaque EVOH resin are uniformly and stably present in the mixed solution, so that the solution temperature after mixing is 20 ° C. to 50 ° C. It is preferable to hold between ℃. When the solution temperature after mixing is less than 20 ° C., the transparent EVOH resin may be gelled, which is not preferable. Moreover, when the solution temperature after mixing exceeds 50 ° C., the opaque EVOH resin may be redissolved and become transparent, which is not preferable. A more preferable solution temperature after mixing is 25 ° C to 35 ° C.

  Then, after the mixed solution of “solution a” and “solution b” is maintained at the above solution temperature, the mixed solution is applied to a predetermined portion, and then heat treatment is performed, so that the transparent EVOH resin is opaque. An EVOH resin layer made of EVOH resin can be obtained. The heat treatment temperature is preferably in the range of 100 ° C. to 150 ° C. in order to achieve both the productivity of the EVOH resin layer and the light diffusibility and translucency of the obtained light diffusing incombustible sheet. If it is less than 100 degreeC, a solvent may remain in the EVOH resin layer and the quality may be deteriorated. On the other hand, when the temperature exceeds 150 ° C., the strength characteristics of the EVOH resin layer may deteriorate, which is not preferable. The heat treatment temperature is more preferably in the range of 110 ° C to 140 ° C.

  The EVOH (A) constituting the EVOH resin that is transparent (a) and the EVOH (B) constituting the EVOH resin (b) that is opaque may be EVOH having the same ethylene content. Considering that the condition setting and the condition accuracy at the time of manufacture are easy, it is preferable that the ethylene content of EVOH (A) is different from the ethylene content of EVOH (B). Specifically, the ethylene content of EVOH (B) is preferably large in the range of 0.5 mol% to 10 mol%, more preferably 1 mol% to 5 mol, relative to the ethylene content of EVOH (A). It is large in the range of%.

  The solvent used for dissolution and gelation is preferably a water / alcohol system as described above, specifically, water / isopropanol, water / n-propanol, water / n-butanol, water / sea-butanol, Water / isobutanol is preferred. In addition, it is preferable to mix 1-30% of formic acid, phenol, dimethylformamide, N-methylpyrrolidone and the like into the solvent because the solution stability and transparency are improved.

  If the concentration of the EVOH resin in the EVOH resin solution is less than 1% by mass, the coating layer after drying becomes too thin, the surface becomes cloudy and the transparency is impaired. On the other hand, if the concentration exceeds 20% by mass, the workability during coating is inferior because the solution concentration is high, and gloss unevenness due to uneven drying of the coating layer is likely to occur, and the solution concentration should be selected from the range of 1 to 20% by mass. Is desirable.

  In order to improve the slipping property of the light diffusing incombustible sheet of the present invention, the EVOH resin layer preferably contains fine particles. For example, by adding fine particles to the EVOH resin solution, the EVOH resin layer can contain fine particles.

  The proportion of the fine particles in the EVOH resin layer is preferably 0.1 to 12 parts by mass of the fine particles with respect to 100 parts by mass of the EVOH resin. When the proportion of the fine particles is less than 0.1 parts by mass, the tackiness of the EVOH resin layer surface is increased, and the handleability when processing or constructing the light diffusion incombustible sheet is not preferable. When the proportion of the fine particles exceeds 12 parts by mass, the transparency may decrease, which is not preferable.

  The average particle diameter of the fine particles is preferably 2 μm or less, more preferably 0.05 to 2 μm, and still more preferably 0.1 to 1 μm. If it exceeds 2 μm, there is a problem that the transparency and daylighting of the light diffusing incombustible sheet deteriorate, which is not preferable. In order to reduce the secondary aggregation of the fine particles and sharpen the particle size distribution, when the fine particles are dispersed in a solvent, the surface state of the fine particles may be made hydrophilic or hydrophobic with a silane coupling agent or the like. desirable. Further, stirring for dispersion is an important factor, and strong stirring by using a homogenizer or the like is desirable as much as possible.

  As fine particles, aluminum, titanium, iron, cerium, yttrium, manganese, silicon, tin, zinc, copper, bismuth, cobalt, and composites of these metal oxides, and the surface of the metal oxide are coated with an organic substance. As long as it is colorless and transparent fine particles imparted with hydrophilicity or hydrophobicity, it is not particularly limited.

  The thickness of the EVOH resin layer 14 is preferably in the range of 0.1 to 20 μm, and more preferably 0.2 to 15 μm. When the thickness is less than 0.1 μm, the plasticizer and the unreacted monomer are diffused and transmitted from the thermoplastic resin layer 9 to the surface layer of the EVOH resin layer to reduce the antifouling property or when the EVOH resin layer 14 is wiped off. In addition, there is a problem that the EVOH resin layer is partially detached when the light diffusion non-combustible sheet is bent. On the other hand, when the thickness exceeds 20 μm, the rigidity is excessively increased, and there are problems in workability and handleability.

  Examples of the method of laminating the EVOH resin layer 14 include a transfer method in which an EVOH resin solution is coated on a cover film 11 such as polyethylene terephthalate and dried, and then transferred to a laminate, and a coating method in which an EVOH resin solution is directly coated on a laminated sheet. There is no particular limitation.

  When the flexibility of the EVOH resin laminate is required, it is better to make the outermost EVOH resin layer thinner, and a transfer method and a solution coating method are used.

  When the transfer method is used as a method for laminating the EVOH resin layer 14 in manufacturing the light diffusing incombustible sheet of the present invention, the EVOH resin solution is coated on the cover film 11, and the EVOH resin solution is solidified to form a surface. After forming an EVOH resin layer having fine irregularities on the surface, and applying adhesive-2 on the surface opposite to the surface where the EVOH resin layer is in contact with the cover film 11 as necessary, the cover film 11 / EVOH resin layer 14 or cover film 11 / EVOH resin layer 14 / adhesive-2 layer 13 or the like is used as a cured resin layer 5 or cured resin layer 5 / thermoplastic resin layer 9, cured resin layer 5 / adhesive-1. After stacking with a laminated sheet having a laminated structure such as layer 8 / thermoplastic resin layer 9 and the like, a light diffusing incombustible sheet is produced by a method in which the outermost cover film 11 is peeled off. It may be. Here, the cover film 11 is not particularly limited, but is a polyolefin such as polyethylene, polypropylene, polynorbornene, polystyrene, polyvinyl chloride, acrylic resin, methacrylic resin, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane. (Tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin), fluororesin such as ethylene-tetrafluoroethylene copolymer and perfluoroethylene-propene copolymer, polyester such as polymethyl methacrylate (PMMA); aliphatic polyamide, aromatic polyamide, etc. And polyamides. Of these, polyester films (hereinafter sometimes referred to as PET films) are preferable in terms of performance and cost.

  Although it does not specifically limit as thickness of the cover film 11, It is 12-200 micrometers, More preferably, it is 20-150 micrometers. When the thickness is less than 12 μm, it is not only difficult to ensure the flatness of the EVOH resin layer and thus the light diffusing incombustible sheet, but there is a problem that the cover film 11 is torn when the cover film 11 is peeled off. On the other hand, if it exceeds 200 μm, not only the process passability is inhibited, but also there is a problem in terms of cost.

The surface of the cover film 11 is roughened from the viewpoint that it becomes easy to impart designability, post-processability by tack reduction, and handleability to the light diffusion incombustible sheet of the present invention. A roughened surface is preferable. The degree of roughening of the roughened surface of the cover film 11 is 3 to 60%, more preferably 5 to 40%, as defined by JIS Z 8741. If the glossiness of the cover film 11 is less than 3%, the total light transmittance of the obtained light diffusing incombustible sheet is lowered, which is not preferable. On the other hand, if the glossiness exceeds 60%, the haze of the obtained light-diffusing incombustible sheet is lowered, which is not preferable.
The cover film 11 is provided with a corona treatment, a silicon-based or fluorine-based mold release within the range not inhibiting the present invention in order to prevent the coating liquid from being peeled off or to facilitate the peeling of the cover film from the light diffusing incombustible sheet. Treatment with an agent may be performed.

  As for the coating method in which the EVOH resin solution is directly coated on the laminated sheet, the coating can be performed by using an existing method. The surface of the laminated sheet coated with the EVOH resin solution may also be the thermosetting resin layer 5, the thermoplastic resin layer 9, or an adhesive layer described later.

As long as the effect of the present invention is not hindered, the use of an adhesive in the laminated portion of the light diffusion incombustible sheet is not restricted. For example, the adhesive is used between the cured resin layer 5 and the thermoplastic resin layer 9. Agent-1 layer 8 is provided, or adhesive-2 layer 13 is provided using an adhesive between EVOH resin layer 14 and thermoplastic resin layer 5 or between EVOH resin layer 14 and cured resin layer 5. You may improve the peeling characteristic of a light-diffusion incombustible sheet.
The adhesive to be used is not particularly limited, and vinyl chloride-based, urethane-based, polyester-based, epoxy-based and acrylic-based adhesives can be used, and vinyl chloride-based and urethane-based materials are preferable.
When the anti-peeling property of the light diffusing incombustible sheet is particularly important, a curing agent such as an epoxy type or an isocyanate type may be used as an adhesive and cured. The application amount of the adhesive is 0.1 to 20 g / m ² , more preferably 0.2 to 10 g / m ² in the drying stage. In consideration of process passability during production, it is more preferable that there is almost no tack at room temperature. For example, when the adhesive-1 layer 8 and the adhesive-2 layer 13 are provided using an adhesive at two or more places, the brand of the adhesive may be the same or different.

The light diffusing incombustible sheet of the present invention has a total light transmittance of 80% or more, and a light diffusing incombustible sheet obtained that the haze is 60% or more sufficiently diffuses light after sufficiently transmitting light. The total light transmittance is preferably 85% or more and the haze is preferably 70% or more. Here, the value of the total light transmittance is defined in “Testing Methods for Optical Properties of Plastics”, “5.5 Light Transmittance and Total Light Reflectance” of JIS K 7105. Specifically, this is a value obtained by measuring the total light transmission amount using an integrating sphere measuring device and obtaining the total light transmittance, and the haze value is defined in “Optical of plastic” in JIS K 7105. In accordance with “6.4 Haze”, specifically, diffuse transmittance and total light transmittance are measured using an integrating sphere type measuring device, and “Testing Methods for Optical Properties of Plastics”. It is a value obtained by the ratio.
In order for the light diffusing incombustible sheet of the present invention to satisfy a total light transmittance of 80% or more and a haze of 60% or more, among the EVOH resins constituting the EVOH resin layer, a gelled EVOH resin is used. It is preferable that it is 20-80 mass%.

  In addition, the light diffusion incombustible sheet of the present invention has a dynamic friction coefficient of 2 or less of the outermost layer of the EVOH resin layer according to JIS K 7125, which ensures the slip property (sliding property) of the light diffusion incombustible sheet. The diffusion incombustible sheet is preferable from the viewpoint of improving work characteristics when performing secondary processing such as product processing, and the dynamic friction coefficient is more preferably 1.5 or less. The dynamic friction coefficient is an index of the degree of unevenness of the sheet surface. For example, by adding fine particles to the EVOH resin layer or forming fine unevenness on the EVOH resin layer with a cover film, the dynamic friction coefficient of the EVOH resin layer Can be 2 or less.

  Furthermore, the light diffusion incombustible sheet of the present invention has a high frequency welder welding strength of 3 kg / 30 mm width or more, and heat weldability when heat diffusion between the light diffusion incombustible sheets or between the light diffusion incombustible sheet and another sheet is performed. It is preferable from the point which is excellent, and it is preferable that it is 4 kg / 30mm width or more. By providing the EVOH resin layer in the light diffusion sheet of the present invention, the high-frequency welder welding strength can be 3 kg / 30 mm width or more.

In addition, the light diffusion incombustible sheet of the present invention has a total calorific value of 8 MJ / 20 in 20 minutes after the start of heating in the exothermic test in which the surface of the sheet is irradiated with radiant heat of 50 kW / m ² from a radiant electric heater. It is preferable from the viewpoint of nonflammability of the sheet that it is m ² or less and the maximum heat generation rate does not exceed 200 kW / m ² for 20 minutes after the start of heating for 10 seconds or more. This parameter is a numerical value indicating how incombustible the sheet of the present invention is based on the evaluation method in the Building Standard Law.

  Although it does not specifically limit as embodiment of the light diffusion incombustible sheet of this invention, EVOH resin layer 14 / adhesive agent-2 layer 13 / cured resin layer 5, EVOH resin layer 14 / adhesive agent-2 layer 13 / Cured resin layer 5 / adhesive layer-2 layer 13 / EVOH resin layer 14, EVOH resin layer 14 / adhesive-2 layer 13 / thermoplastic resin layer 9 / cured resin layer 5, thermoplastic resin layer 9 / cured resin Layer 5 / adhesive layer-2 layer 13 / EVOH resin layer 14, EVOH resin layer 14 / adhesive-2 layer 13 / thermoplastic resin layer 9 / cured resin layer 5 / adhesive layer-2 layer 13 / EVOH resin layer 14, EVOH resin layer 14 / adhesive-2 layer 13 / thermoplastic resin layer 9 / adhesive-1 layer 8 / cured resin layer 5, thermoplastic resin layer 9 / adhesive-1 layer 8 / cured resin layer 5 / Adhesive-2 layer 13 / EVOH resin layer 14, EVOH resin layer 14 / adhesion -2 layer 13 / thermoplastic resin layer 9 / adhesive-1 layer 8 / cured resin layer 5 / adhesive-2 layer 13 / EVOH resin layer 14, EVOH resin layer 14 / adhesive-2 layer 13 / thermoplastic resin Layer 9 / adhesive-1 layer 8 / cured resin layer 7 / adhesive-1 layer 8 / thermoplastic resin layer 9, EVOH resin layer 14 / adhesive-2 layer 13 / thermoplastic resin layer 9 / adhesive-1 Layer 8 / cured resin layer 5 / adhesive-1 layer 8 / thermoplastic resin layer 9 / adhesive-2 layer 13 / EVOH resin layer 14 and the like. Even when the light diffusing sheet is transported, the cover film 11 is kept laminated on at least one of the outermost layers of the light diffusing incombustible sheet, and the cover film 11 is peeled off when the light diffusing incombustible sheet is used. Good.

The method for producing the light diffusing incombustible sheet of the present invention is not particularly limited as long as the utility of the present invention can be obtained. For example, the following production method is preferably selected.
First, when the glass fiber fabric 3 is impregnated with the curable resin 4 and then cured with light or heat, in order to facilitate the flatness and handleability of the cured resin layer 5, an uncured state is formed on the cover film 11. After applying the curable resin 4, the glass fiber fabric 3 may be embedded and then cured to form a laminate. Alternatively, the thermoplastic resin layer 9 is laminated on the cover film 11 for the purpose of ensuring the thickness uniformity and lighting of the light diffusing incombustible sheet, and further ensuring the productivity, and further the uncured state on the thermoplastic resin layer 9 side. After applying the curable resin 4 and embedding the glass fiber cloth 3, the cover film 11 / thermoplastic resin layer 9 / the curable resin in which the glass fiber cloth is embedded is applied with pressure from above and below to be curable. The laminate may be formed by curing the resin. Thereafter, the cover film 11 is peeled from the laminate, and the EVOH resin layer is formed on the obtained laminate sheet by the transfer method, the coating method, etc. described above, and the light diffusion incombustible sheet of the present invention can be obtained.
For the laminate, for example, cover film 11 / cured resin layer 5, cover film 11 / thermoplastic resin layer 9 / cured resin layer 5, cover film 11 / thermoplastic resin layer 9 / adhesive-1 layer 8 / cured. Resin layer 5, cover film 11 / thermoplastic resin layer 9 / adhesive-1 layer 8 / cured resin layer 7 / adhesive-1 layer 8 / thermoplastic resin layer 9 / cover film 11, cover film 11 / thermoplastic resin The layer 9 / adhesive-1 layer 8 / cured resin layer 5 / cover film 11 can be selected.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely and in detail, the scope of the present invention is not limited to a following example.

  Dynamic friction coefficient (slip property): A load of 200 g is applied to a 63 mm square test piece according to JIS K 7125 “Plastic Film and Sheet Friction Coefficient Test Method”, and the tension is applied at a speed of 100 mm / min. The value divided by the dynamic friction coefficient.

  Total light transmittance: According to “Testing methods for Optical Properties of plastics” of JIS K 7105, “5.5 Light transmittance and total light reflectance”. Specifically, the total light transmittance was measured using a direct reading haze meter manufactured by Toyo Seiki, which is an integrating sphere measuring device, and the total light transmittance was determined.

  Haze: The method for measuring the haze of the transparent noncombustible sheet was in accordance with “6.4 Haze” of “Testing Methods for Optical Properties of Plastics” of JIS K7105. Specifically, the diffuse transmittance and the total light transmittance were measured using an integrating sphere measuring device, and expressed by the ratio.

Flammability test: A corn calorimeter test according to ISO 5660 Part 1 was performed under the conditions of a heating intensity of 50 kW / m ² and a test time of 20 minutes, and the total calorific value and the heat generation rate were measured.
The acceptance criteria as a non-combustible film material were a total calorific value of 8 MJ / m ² or less, a heating rate exceeding 10 seconds and not exceeding 200 kW / m ² , and that no pinholes were confirmed in the sample after the test. The test results were evaluated as follows.
Total calorific value 8 MJ / m ² or less: Pass, Exceed 8 MJ / m ² : Fail Heat generation rate Exceed 10 seconds and do not exceed 200 kW / m ² : Pass
Over 10 seconds and over 200 kW / m ² : Fail Pinhole Not recognized: Pass, Accepted: Fail

Flame retardancy test: Flame retardancy was evaluated according to JIS L 1091 “Flammability test for textile products”. The test results were displayed as follows.
○: Category 3 passed, ×: Category 3 failed

Antifouling property: The multilayer film cut into a size of 2 cm × 2 cm was wiped off with oily red ink (Mitsubishi Marker, Mitsubishi Pencil Co., Ltd.) and gauze with benzine attached after 24 hours. Moreover, soy sauce (Kikkoman Co., Ltd. Kikkoman deep mouth) was applied, and 24 hours later, it was wiped off with gauze moistened with Mama lemon (synthetic detergent for kitchen) of Lion Corporation.
Judgment criteria A (pass): No dirt remains B (pass): Unclean dirt remains.
C (failure): Clear dirt remains D (failure): After wiping remains or the surface layer is detached.

  High frequency welder: Two A4 size test pieces are superposed, YE7000A manufactured by Yamamoto Vinita Co., Ltd. is used, and the test pieces are heat-sealed by heating them to a 250 mm x 50 mm width electrode at a current of 1 A for 5 seconds. I let you. The heat-sealed test piece was cut to a width of 30 mm, 90-degree T-type peeling was performed at a peeling speed of 200 mm / min, and welder fusion peeling strength was measured.

Example 1
As the glass fiber fabric 3, a glass cloth H350F3 manufactured by Unitika Glass Fiber Co., Ltd. (the number of warps and wefts is 32, 31/25 mm, the thickness is 0.3 mm, and the mass is 250 g / m ² ) is 370 ° C. The sizing agent attached to the glass cloth was removed by heating in a heating furnace for 2 minutes. Thereafter, a styrene-based silane coupling agent (KBM1403) manufactured by Shin-Etsu Silicon Co., Ltd. was diluted to 5% with a 30% aqueous methanol solution, the glass fiber fabric 3 was immersed and dehydrated, and then heated with a 100 ° C. hot air dryer. Dry for 30 minutes.

  As the curable resin 4 in an uncured state, 100 parts by mass of an orthophthalic acid-based unsaturated polyester resin (trade name: Rigolac 1635) sold by Showa High Polymer Co., Ltd. and a product sold by Nippon Oil & Fats Co., Ltd. 0.5 parts by mass of a methyl ethyl ketone peroxide (trade name: Permec N), which is a polymerization initiator, was stirred for about 3 minutes using a stirrer. And the obtained mixture was left to stand under vacuum for about 5 minutes and deaerated to obtain an uncured curable resin 4.

  As the cover film 11, two PET films having a thickness of 100 μm were used.

One of the two cover films 11 is thermocompression-bonded with a polyvinyl chloride film having the following composition selected as the thermoplastic resin 9 and a heat laminating roll set at 120 ° C., and the cover film 11 / thermoplastic resin layer 9 laminates were obtained. Thereafter, a urethane adhesive (trade name: Sunplex 435A) manufactured by Murayama Chemical Co., Ltd. was diluted with a 20% aqueous isopropyl alcohol solution to a concentration of 20%, and further a 5% DIC block isocyanate curing agent was added. Was applied to the vinyl chloride film side at 10 g / m ^{2 and} dried at 80 ° C. for 5 minutes to obtain a laminated film 12 comprising cover film 11 / thermoplastic resin layer 9 / adhesive-1 layer 8. It was.
Vinyl chloride resin 65 parts by mass Di-2-ethylhexyl phthalate 15 parts by mass Phosphate ester flame retardant plasticizer 15 parts by mass Ba-Zn stabilizer 3 parts by mass UV absorber, light stabilizer, lubricant 2 parts by mass Inorganic coloring Agent Trace amount (0.005 parts by mass)

On the adhesive-1 layer 8 side of the laminated film 12 cut to 200 mm × 300 mm, the uncured curable resin 4 is applied in an amount of 150 g / m ² in a central area of 150 mm × 250 mm, and then applied. The glass fiber fabric 3 having a size of 150 mm × 250 mm was placed on the curable resin 4 in a state. Leave for about 5 minutes, and after confirming that the uncured curable resin 4 is sufficiently impregnated into the glass fiber cloth 3 and degassed, the other of the uncured curable resin 4 including the glass fiber cloth 3 is removed. The other cover film 11 on the surface is in contact with the uncured curable resin 4 and is laminated so that no bubbles are mixed in the uncured curable resin 4 and has the form shown in FIG. Got.

  Cover film 11 / thermoplastic resin layer 9 / adhesive-1 layer 8 / (in the uncured state in which the glass fiber fabric 3 is embedded) containing the uncured curable resin 4 thus obtained. A laminated structure of the cured resin layer 5 / cover film 11, that is, an uncured state by applying pressure by applying a roller by hand from above both outermost layer cover films 11 of the laminate having the laminated structure of FIG. The remaining bubbles between the curable resin 4 and the glass fiber fabric 3 were removed, and the thickness of the curable resin 4 in an uncured state was made uniform. The diameter of the roller was 20 mm and the length was 200 mm.

  Next, the laminate containing the uncured curable resin 4 was put under pressure in a hot press machine at 80 ° C. and left for 30 minutes to cure the uncured curable resin 4. Next, the temperature of the hot air dryer was raised to 100 ° C. and left for 10 minutes for further curing.

After cooling the laminated body containing the cured curable resin 4 taken out from the hot air dryer, the cover films 11 on both outermost layers of the laminated body are peeled and removed, and the thermoplastic resin layer 9 / adhesive-1 layer 8 / cured. A laminated sheet 10 having the laminated structure of the resin layer 5, that is, the laminated structure of FIG. 3 was obtained.
As shown in Table 1, the obtained laminated sheet 10 has good flame retardancy, nonflammability, and daylighting properties, but has light diffusibility, antifouling property, surface tackiness, high frequency welder weldability, and the like. There was a bad problem.

  In order to prepare an EVOH mixed solution for solution coating, 10 parts of EVOH resin (A) (trade name: Eval E105: ethylene content is 44 mol%, saponification degree is 99%) manufactured by Kuraray Co., Ltd., n-propanol 52 parts, 28 parts of water, and 10 parts of N methylpyrrolidone were heated to dissolve the resin to obtain a colorless and transparent EVOH solution (A) having a solution temperature of 75 ° C. Next, EVOH resin (B) (trade name: Eval G156: ethylene content is 48 mol%, saponification degree is 99%), 10 parts, n-propanol 81 parts, and water 9 parts are heated to dissolve the resin to obtain a solution. After obtaining a colorless and transparent solution having a temperature of 70 ° C., the solution temperature was cooled to 15 ° C. and vigorously stirred with a homogenizer for 24 hours to obtain an opaque and gelled fine particle EVOH solution (B). It was. The obtained EVOH solution (A) and the obtained EVOH solution (B) are in a mass ratio of (A) / (B) = 60/40, and the solution temperature of the mixed solution becomes 30 ° C. The mixture was vigorously stirred in such a state that an EVOH mixed solution (C) was obtained.

Next, 10 g / m ^{2 of} the adhesive used above was applied to the surface of the thermoplastic resin layer 9, which is one of the outermost layers of the laminated sheet 10, and dried at 80 ° C. for 5 minutes to form an adhesive-2 layer 13. After that, 10 g / m ^{2 of} the above EVOH mixed solution (C) was applied and heat-treated at 120 ° C. for 5 minutes, EVOH resin layer 14 / adhesive-2 layer 13 / thermoplastic resin layer 9 / adhesive-1 layer 8 A light diffusing incombustible sheet of Example 1 having the laminated structure of the cured resin layer 5, that is, the laminated structure of FIG. 4 and comprising an EVOH resin layer in which the EVOH resin layer is transparent and an opaque EVOH resin is obtained.

  As shown in Table 1, it was confirmed that the obtained light diffusion incombustible sheet had good antifouling property, surface tackiness, and welder weldability.

Example 2
In Example 1, instead of laminating the cover film 11 on the laminate of the laminated film 12 / the curable resin 4 (in an uncured state in which the glass fiber fabric 3 is embedded), a laminate is produced. One more laminated film 12 used in Example 1 was prepared, and the curable resin 4 side of the laminate and the adhesive-1 layer 8 of the laminated film 12 were overlapped to form the cover film 11 / thermoplastic resin layer 9. / Adhesive-1 layer 8 / Laminated body having a laminated structure of cured resin layer 5 (uncured state in which glass fiber fabric 3 is embedded) / adhesive-1 layer 8 / thermoplastic resin layer 9 / cover film 11 It was created. In the same manner as in Example 1 except for the above, EVOH resin layer 14 / adhesive agent-2 layer 13 / thermoplastic resin layer 9 / adhesive agent-1 layer 8 / cured resin layer 5 / adhesive agent-1 layer 8 / heat The light diffusing incombustible sheet of Example 2 having a laminated structure of a plastic resin layer 9 / adhesive-2 layer 13 / EVOH resin layer 14, wherein the EVOH resin layer is composed of a transparent EVOH resin and an opaque EVOH resin. Obtained. The evaluation results are shown in Table 1. As with the light diffusion incombustible sheet of Example 1, good performance was shown.

Example 3
In Example 2, in preparing the laminate, the uncured curable resin 4 was 100 parts by mass of epoxy acrylate resin (trade name: NEOPOL 8126) manufactured by Nippon Iupika Co., Ltd., 20 parts by mass of styrene monomer, and photomultiplier. The same as in Example 2 except that the cured resin layer 5 was formed by changing to a photocurable resin composed of 1 part by mass of the catalyst and irradiating with an ultraviolet irradiator to cure the uncured curable resin 4. EVOH resin layer 14 / adhesive-2 layer 13 / thermoplastic resin layer 9 / adhesive-1 layer 8 / cured resin layer 5 / adhesive-1 layer 8 / thermoplastic resin layer 9 / adhesive-2 A light diffusing incombustible sheet of Example 3 having a laminated structure of layer 13 / EVOH resin layer 14 and comprising an EVOH resin having a transparent EVOH resin layer and an EVOH resin having an opaque EVOH resin layer was obtained. Although an evaluation result is shown in Table 1, it showed favorable performance like the light diffusion incombustible sheet of Examples 1-2.

Comparative Example 1
When the laminated sheet 10 described in Example 1 was used as a light diffusion noncombustible sheet, as shown in Table 1, the antifouling property was poor, the dynamic coefficient of friction was large, and the high frequency welder strength was small. It became a result inferior to the light-diffusion incombustible sheet of an Example in terms of the next workability and the handleability.

Comparative Example 2
In the light diffusion incombustible sheet of Example 2, the EVOH mixed solution (C) applied to the laminated sheet 10 was adjusted to the EVOH solution (A), except that the EVOH mixed solution (C) was adjusted, and the EVOH resin layer was transparent. The light diffusing incombustible sheet of Example 2 was obtained. The evaluation results are shown in Table 1. The haze was small and the light diffusibility was poor.

Comparative Example 3
In the light diffusion incombustible sheet of Example 2, the EVOH mixed solution (C) applied to the laminated sheet 10 was changed to the EVOH solution (B) except that the EVOH mixed solution was adjusted in the same manner as in Example 2, and the EVOH resin layer was opaque. The light diffusing incombustible sheet of Example 3 was obtained. The evaluation results are shown in Table 1. The total light transmittance was small, and the light transmission and antifouling properties were inferior.

1. Glass fiber (warp)
2. Glass fiber (weft)
3. 3. Glass fiber fabric 4. Curable resin Hardened resin layer8. Adhesive-1 layer9. Thermoplastic resin layer 10. Laminated sheet 11. Cover film 12. Laminated film 13. Adhesive-2 layer14. EVOH resin layer

  The light diffusing incombustible sheet of the present invention is used for lighting devices such as surface illumination devices, internally illuminated signboards, light transmissive screens for projectors or televisions, internally illuminated light film ceilings, etc. It is effective in preventing equipment malfunctions, damage such as earthquakes, and injury caused by scattering.

Claims (6)

A glass fiber fabric is embedded inside the cured resin layer, and a thermoplastic resin layer is laminated on at least one surface of the cured resin layer with or without an adhesive layer. A light diffusing incombustible sheet characterized in that an ethylene-vinyl alcohol copolymer resin layer is laminated on the surface with or without an adhesive layer, and satisfies the following (a) to (c).
(A): The ethylene-vinyl alcohol copolymer resin layer is formed of a transparent ethylene-vinyl alcohol copolymer resin and an opaque ethylene-vinyl alcohol copolymer resin. (B): Total light transmission Rate is 80% or more (c): Haze is 60% or more   The ethylene content of the opaque ethylene-vinyl alcohol copolymer resin is large in the range of 0.5 mol% to 10 mol% with respect to the ethylene content of the transparent ethylene-vinyl alcohol copolymer resin. The light diffusion incombustible sheet according to claim 1. The light diffusion incombustible sheet according to claim 1 or 2 which further satisfies the following (d) and (e).
(D): Dynamic friction coefficient of outermost surface of ethylene-vinyl alcohol copolymer resin layer is 2 or less (e): High frequency welder welding strength is 3 kg / 30 mm width or more   The light diffusion incombustible sheet according to any one of claims 1 to 3, wherein an outer surface of at least one of the ethylene-vinyl alcohol copolymer resin layer or the thermoplastic resin layer is a roughened surface.   The roughened surface is a surface obtained by transferring the roughened surface of the cover film that has been roughened so that the glossiness specified by JIS Z 8741 is 3 to 60%. The light diffusion incombustible sheet as described.   A transparent solution containing an ethylene-vinyl alcohol copolymer and having a solution temperature of 30 ° C. to 75 ° C., and the transparent solution or another ethylene-vinyl alcohol copolymer. An opaque solution obtained by cooling the transparent solution obtained below to 20 ° C. is mixed to obtain a mixed solution having a solution temperature of 20 ° C. to 50 ° C., and then heat treatment is performed at 100 ° C. to 150 ° C. 6. An ethylene-vinyl alcohol copolymer resin layer comprising a transparent ethylene-vinyl alcohol copolymer resin and an opaque ethylene-vinyl alcohol copolymer resin is formed. A method for producing a light diffusing incombustible sheet according to claim 1.

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