JP2017100341A - Sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet having a laminated structure that a glass fiber cloth, a first resin layer contained in a state of impregnated in the glass fiber cloth, and a second resin layer that is laminated on at least one surface side of the first resin layer and contains a fluorine resin, which hardly causes peeling of the fluorine resin layer.SOLUTION: There is provided a sheet which contains at least one glass fiber cloth, a first resin layer contained in a state of impregnated in the glass fiber cloth, and a second resin layer that is laminated on at least one surface side of the first resin layer, where the first resin layer contains a resin other than a fluorine resin, the second resin layer contains a fluorine resin and an acrylic resin, and the fluorine resin is polyvinylidene fluoride.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sheet containing a glass fiber fabric and a fluororesin. Specifically, the present invention relates to a sheet containing a glass fiber fabric and a fluororesin excellent in translucency and incombustibility.

  Conventionally, a sheet containing a glass fiber fabric and a resin is known as a sheet used for a membrane material, for example, a roof material of a building, a tent warehouse material, and the like. Especially, it is known that the sheet | seat containing a glass fiber fabric and a fluororesin is excellent in nonflammability, antifouling property, a softness | flexibility, etc. When the sheet is used for a roof material of a building, a tent warehouse material, or the like, it may be required that the sheet can be lit from the outside to the inside, and an excellent translucency is also required.

  As a sheet containing a glass fiber fabric and a fluororesin, a film material formed by laminating at least one glass fiber fabric and a fluororesin layer having a melting point of 100 to 250 ° C. impregnated in the glass fiber fabric is known. (For example, refer to Patent Document 1). According to the film material, the film material has sufficient light transmissivity, and even when used for a long time, the film material hardly deteriorates in strength or deteriorates in light transmissivity due to dirt. It is said that it is possible to provide a well-balanced film material with excellent time translucency in addition to the properties of four beats.

  In addition, as a sheet made of glass fiber fabric and fluororesin, it consists of a glass fiber fabric and a resin coating layer made of fluororesin impregnated in the glass fiber fabric. A glass fiber sheet having a specific configuration, and the light transmission property is such that the total light transmittance is 50% or more and the parallel light transmittance is 5% or less. A light-diffusing glass fiber sheet is known (for example, see Patent Document 2). According to the sheet, it is said that a light diffusing sheet that realizes sufficient translucency at the same time under conditions having high light diffusibility can be realized.

JP-A-9-76420 Japanese Patent No. 4359967

  However, the sheet disclosed as an example of Patent Document 1 that is excellent in translucency is 32.5% even if the total light transmittance is high, and the sheet disclosed as an example of Patent Document 2 is a total light transmission. Even if the rate is high, it is 60.4%. Thus, in the sheet | seat containing a glass fiber fabric and a fluororesin, the level of translucency which those skilled in the art think that it is excellent was a thing whose total light transmittance is about 60% at most. In other words, it has been common technical knowledge that a sheet containing a glass fiber fabric and a fluororesin cannot obtain such a high translucency that the total light transmittance exceeds 70%.

  When the present inventors examined the reason why the sheets disclosed in Patent Document 1 and Patent Document 2 cannot obtain high translucency, the refractive index of the glass fiber fabric is about 1.5 to 1.7. Has a large absolute value of the difference in refractive index between them, and a large amount of light is scattered at the interface between the glass fiber and the fluororesin. I learned that I could not get sex.

  Therefore, the present inventors, for example, impregnated a glass fiber fabric with a resin layer having a refractive index close to the sheet containing the glass fiber fabric and the fluororesin, and impregnated it with the fluororesin layer. It was found that the light scattering on the glass fiber surface can be reduced by laminating the layers, and the obtained sheet can obtain excellent translucency.

  However, as a result of further studies by the present inventors, it has been found that the sheet obtained as described above has a problem that the laminated fluororesin layer may be easily peeled off. Such a problem is a problem that is not naturally recognized in a sheet composed of a glass fiber fabric and a fluororesin resin layer impregnated in the glass fiber fabric as disclosed in, for example, Patent Document 1 or 2.

  Then, this invention solves the said problem, and is laminated | stacked on the at least one surface side of the 1st resin layer contained in the state impregnated with the glass fiber fabric, this glass fiber fabric, and the said 1st resin layer. Another object of the present invention is to provide a sheet having a laminated structure including a second resin layer containing a fluororesin, and in which the fluororesin layer hardly peels off.

  When the present inventors have intensively studied to solve the above problems, a glass fiber fabric, a resin layer containing a resin other than a fluororesin impregnated in the glass fiber fabric, and one surface of the resin layer A sheet including a fluororesin layer laminated on the side, wherein the fluororesin layer includes a fluororesin and an acrylic resin, and by specifying polyvinylidene fluoride among the fluororesins, It was learned that exfoliation hardly occurs. The present invention has been completed by further studies based on this finding.

That is, this invention provides the sheet | seat of the aspect hung up below.
Item 1. Including at least one glass fiber fabric, a first resin layer included in an impregnated state of the glass fiber fabric, and a second resin layer laminated on at least one surface side of the first resin layer. The first resin layer includes a resin other than a fluororesin, the second resin layer includes a fluororesin and an acrylic resin, and the fluororesin is polyvinylidene fluoride.
Item 2. Item 2. The sheet according to Item 1, wherein an absolute value of a difference in refractive index between the glass fiber fabric and the first resin layer is 0.05 or less.
Item 3. Item 3. The sheet according to Item 1 or 2, wherein the resin contained in the first resin layer is a thermoplastic resin.
Item 4. Item 4. The sheet according to any one of Items 1 to 3, wherein the resin layer laminated in a state in which the second resin layer is in contact includes a vinyl chloride resin, an acrylic resin, or a saturated polyester resin.
Item 5. Item 5. The sheet according to Item 4, wherein the resin layer laminated with the second resin layer in contact with the second resin layer is the first resin layer.
Item 6. Item 5. The item according to Item 4, further comprising an intermediate layer between the first resin layer and the second resin layer, wherein the resin layer laminated with the second resin layer in contact with the first resin layer is the intermediate layer. Sheet.
Item 7. Item 7. The sheet according to Item 6, wherein the resin contained in the first resin layer and the resin contained in the intermediate layer are different resins.
Item 8. Item 8. The sheet according to Item 6 or 7, further comprising the intermediate layer and a network layer made of a glass fiber network between the first resin layer and the second resin layer.
Item 9. Item 9. The sheet according to any one of Items 1 to 8, wherein a ratio of the glass fiber fabric to a total amount of the glass fiber fabric and the first resin layer is 10 to 70% by mass.
Item 10. Item 10. The sheet according to any one of Items 1 to 9, wherein the total light transmittance is 70% or more.
Item 11. From radiant electric heaters measured according to 4.10.2 exothermic test and evaluation method in “Fireproof and Fireproof Performance Test and Evaluation Method of Operation” of the Building Materials Testing Center (modified version on March 1, 2014) In the exothermic test where the surface of the sheet is irradiated with radiant heat of 50 kW / m ² , the maximum heat generation rate after the start of heating continues for 10 seconds or more and does not exceed 200 kW / m ² , and the total calorific value is 8 MJ / m ² or less. Item 11. The sheet according to any one of Items 1 to 10.
Item 12. Item 12. The sheet according to any one of Items 1 to 11, wherein the peel strength of the second resin layer measured according to JIS K 6854-2: 1999 is 20 N / 25 mm or more.
Item 13. Claim | item 1-12 sheet | seat whose thickness is 0.5 mm or more.

  According to the present invention, at least one glass fiber cloth, a first resin layer contained in an impregnated state of the glass fiber cloth, and a fluororesin laminated on at least one surface side of the first resin layer A second resin layer, the second resin layer comprising a fluororesin and an acrylic resin, wherein the fluororesin is a polyvinylidene fluoride. It is possible to produce an effect that it is difficult for peeling of the material to occur.

It is a cross-sectional schematic diagram which shows an example of the laminated structure of the sheet | seat of this invention. It is a cross-sectional schematic diagram which shows an example of the laminated structure of the sheet | seat of this invention. It is a cross-sectional schematic diagram which shows an example of the laminated structure of the sheet | seat of this invention. It is a cross-sectional schematic diagram which shows an example of the laminated structure of the sheet | seat of this invention.

  The sheet of the present invention includes at least one glass fiber fabric, a first resin layer contained in a state impregnated in the glass fiber fabric, and a second layer laminated on at least one surface side of the first resin layer. A sheet, wherein the first resin layer includes a resin other than a fluororesin, the second resin layer includes a fluororesin and an acrylic resin, and the fluororesin is polyvinylidene fluoride. is there.

Sheet 1 of the laminate structure present invention, as shown in FIGS. 1-4, includes a state in which at least one glass fiber fabric 2 to the first resin layer 3 is impregnated, at least one of the first resin layer 3 It has a laminated structure provided with the second resin layer 4 on the upper side of the surface. In the sheet 1 of the present invention, at least one glass fiber fabric 2 may be included, and a plurality of glass fiber fabrics 2 may be included. For example, as shown in FIG. 2, in the transparent noncombustible sheet 1 of the present invention, two glass fiber fabrics 2 may be arranged so as to be positioned on both surface sides of the first resin layer 3, respectively. .

  Moreover, as FIG. 1-4 shows, in the sheet | seat 1 of this invention, the 1st resin layer 3 has filled the clearance gap between the some glass fiber which comprises the glass fiber fabric 2, and the 1st resin layer One surface side portion 31 and the other surface side portion 32 of 3 communicate with each other through the gap portion.

  Moreover, in the sheet | seat 1 of this invention, although the glass fiber fabric 2 should just be contained in the state which impregnated the 1st resin layer 3, from a viewpoint of raising a total light transmittance further to FIGS. As shown, it is preferable that the first resin layer 3 portion where the glass fiber fabric 2 does not exist is formed on both surfaces of the glass fiber fabric 2.

  In the sheet 1 of the present invention, the second resin layer 4 may be laminated on the upper side of at least one surface of the first resin layer 3, but both surfaces of the first resin layer 3 as shown in FIGS. It is preferable to be laminated.

  In the sheet of the present invention, the first resin layer 3 is laminated with the second resin layer 4 in contact with the first resin layer 3 (that is, the first resin layer 3 and the second resin layer 4 are directly laminated). For example, as shown in FIG. 3, the first resin layer 3 and the second resin layer 4 may be used for the purpose of further improving the adhesion between the first resin layer 3 and the second resin layer 4. Between these, the intermediate layer 5 may be laminated. Also, for example, as shown in FIG. 4, between the first resin layer 3 or the intermediate layer 5 and the fluororesin layer 4, for the purpose of increasing the mechanical strength (hardness) of the sheet 1, A network layer 6 made of glass fiber may be laminated. In FIG. 4, the intermediate layer 5 and the network layer 6 are arranged in this order from the second resin layer 4 side, but the network layer 6 and the intermediate layer 5 are arranged in this order from the second resin layer 4 side. It may be. 4 shows a form including the intermediate layer 5 and the network layer 6, but when the network layer 6 is laminated, the intermediate layer 5 may not be included. The intermediate layer 5 and the network layer 6 may be laminated on one side of the resin layer 3 or may be laminated on both sides as shown in FIG.

Detail the composition of each layer constituting the sheet 1 of each layer of the composition present invention.

[Glass fiber fabric 2]
The glass fiber fabric 2 is composed of a plurality of glass fibers. In the glass fiber fabric 2, the plurality of glass fibers are entangled with each other to form a single fabric. Examples of the glass fiber fabric 2 include a glass fiber fabric (glass cloth) composed of a plurality of warps and a plurality of wefts. The woven structure of the glass fiber woven fabric is not particularly limited, and examples thereof include plain weave, satin weave, twill weave, oblique weave, and woven weave. The woven density of the glass fiber fabric is not particularly limited, but when the resin contained in the sheet 1 is burned, a large through-hole is less likely to be formed in the glass fiber fabric 2 and a more excellent nonflammability performance is maintained. From the viewpoint that the warp and the latitude are 40/25 mm or more, 50/25 mm or more is more preferable.

  About the glass material of the glass fiber which comprises the glass fiber fabric 2, it does not restrict | limit in particular, A well-known glass material can be used. Specific examples of the glass material include alkali-free glass (E glass), acid-resistant alkali-containing glass (C glass), high-strength / high-modulus glass (S glass, T glass, etc.), alkali-resistant glass (AR). Glass) and the like. Among these glass materials, alkali-free glass (E glass) having high versatility is preferable. The glass fibers constituting the glass fiber fabric 2 may be made of one kind of glass material, or may be a combination of two or more kinds of glass fibers made of different glass materials.

  The count of the glass fiber constituting the glass fiber fabric 2 is not particularly limited as long as the glass fiber fabric 2 can be formed. The count of the glass fiber is preferably 20 tex or less from the viewpoint of further improving the translucency of the sheet 1. The glass fiber fabric 2 may be formed of one type of glass fiber, or may be formed of two or more types of glass fiber. The tex count of glass fiber corresponds to the number of grams per 1000 m.

  The glass fiber constituting the glass fiber fabric 2 is preferably a glass yarn in which a plurality of single fibers, which are long glass fibers, are twisted together. The number of single fibers in the glass yarn is preferably about 30 to 500 from the viewpoint of further improving the translucency of the sheet 1. The diameter of the single fiber in the glass yarn is preferably about 3.0 to 10.0 μm from the viewpoint of further improving the translucency of the sheet 1. The count of the glass yarn is preferably 3 to 80 tex from the viewpoint of further improving the translucency of the sheet 1.

  For example, when the sheet 1 of the present invention is used for a daylighting tent among the uses described below, when the visibility through the sheet 1 is important and the haze value is smaller, the single fiber in the glass yarn The number of is more preferably about 30 to 120. From the same viewpoint, the diameter of the single fiber in the glass yarn is more preferably about 3.0 to 6.0 μm, and further preferably about 3.0 to 5.0 μm. Further, from the same viewpoint, the count of the glass yarn is more preferably 3 to 12 tex, and further preferably 3 to 5 tex. Although the diameter of the single fiber in the glass yarn constituting the glass fiber fabric 2 and the count of the glass yarn are within the above ranges, details of the mechanism that makes it easier to further reduce the haze of the sheet 1 are not clear, By satisfying such conditions, the glass fiber fabric 2 is smoothed, and light scattering at the interface with the first resin layer 3 is effectively suppressed. As a result, the haze of the sheet 1 can be further reduced. It is considered to be.

  In addition, for example, when the sheet 1 of the present invention is used for a lighting cover, when light diffusibility is important and the haze value is larger, the number of single fibers in the glass yarn is 180 to 500. The degree is more preferable. From the same viewpoint, the diameter of the single fiber in the glass yarn is more preferably about 7.0 to 10.0 μm, and further preferably about 8.0 to 10.0 μm. From the same viewpoint, the count of the glass yarn is more preferably 20 to 80 tex, further preferably 50 to 80 tex.

  From the viewpoint of enhancing the adhesion between the glass fiber fabric 2 and the second resin layer 3 and further improving the total light transmittance of the sheet 1 of the present invention, the surface of the glass fiber constituting the glass fiber fabric 2 is The surface treatment with a silane coupling agent is preferred.

In the sheet 1, the ratio (mass%) of the glass fiber fabric 2 is such that the total light transmittance of the sheet 1 is further improved and excellent nonflammability is provided, and the glass fiber fabric 2 and the first described later. 10-70 mass% is preferable with respect to the total amount with the resin layer 3, and 20-55 mass% is more preferable. Also, one of the mass of the glass fiber fabric ² (g / ^m 2) is preferably 10~1000 (g / ^{m 2),} more preferably ^{20~800 (g / m 2),} 30~700 (g / m ² ) is more preferred.

As described above, at least one glass fiber fabric 2 may be included in the first resin layer 3, but a plurality of glass fiber fabrics 2 may be included. Here, when the glass fiber fabric 2 includes a plurality of layers, for example, as shown in FIG. 2, the central portion N in the thickness direction of the glass fiber fabric 2 is more than the central portion M in the thickness direction of the first resin layer 3. Further, it is preferable that the glass fiber fabrics 2 are respectively disposed on both surface sides (31 side and 32 side in FIG. 2) of the first resin layer 3 so as to be positioned on the surface side. As described above, the two glass fiber fabrics 2 are disposed so as to be located on both surface sides (31 side and 32 side in FIG. 2) of the first resin layer 3, respectively. Compared to a sheet in which the glass fiber fabric 2 is disposed only in the central portion, the mechanical strength (hardness) can be further increased, and warping due to heat can be more effectively suppressed. More specifically, the shortest distance L1 from the surface of the first resin layer 3 to the central portion N of the glass fiber fabric 2 and the thickness L0 of the first resin layer 3 satisfy the relationship of the following formula (I): It is preferable to satisfy.

Moreover, it is more preferable that one glass fiber fabric 2 is included on each of both surface sides of the first resin layer 3 so as to satisfy the relationship of the formula (I). Furthermore, it is preferable that L1 and L0 satisfy the relationship of the following formula (II).

Moreover, the center part N in the thickness direction of the glass fiber fabric 2 is positioned on the surface side of the center part M in the thickness direction of the first resin layer 3, so that the both sides of the first resin layer 3 It is a case where the glass fiber fabric 2 is respectively arrange | positioned, Comprising: The ratio of the glass fiber fabric 2 in the sheet | seat 1 shall be 10-70 (mass%), and the mass of one sheet of the glass fiber fabric 2 is 20-50 ( g / m ² ) makes it possible to achieve both a high total light transmittance and mechanical strength (hardness) of the sheet 1 in a particularly excellent state.

  From the viewpoint of making the total light transmittance of the sheet higher, the absolute value of the difference in refractive index between the glass fiber fabric 2 and the first resin layer 3 described later is preferably 0.05 or less. Thus, when the absolute value of the difference in refractive index between the glass fiber fabric 2 and the first resin layer 3 is 0.05 or less, light scattering on the surface of the glass fiber can be reduced, and the resulting sheet can be further improved. It becomes possible to improve the light transmittance. From the viewpoint of improving the total light transmittance more effectively, the absolute value of the difference in refractive index between the glass fiber fabric 2 and the first resin layer 3 is more preferably 0.04 or less, particularly preferably 0.03. Hereinafter, more preferably, 0.01 or less is mentioned.

  In addition, the refractive index of the glass fiber fabric 2 is measured according to the method B of JIS K7142: 2008. Specifically, first, the glass fiber constituting the glass fiber fabric is pulverized to such an extent that a Becke line can be observed when the glass fiber is observed with an optical microscope at a magnification of 400 times. Then, using a halogen lamp provided with a D-line interference filter as a light source, using an optical microscope, observed and measured under conditions of a magnification of 400 times and a temperature of 23 ° C., and refracted the average value of three tests. The value of rate. Moreover, the measurement of the refractive index of the 1st resin layer 3 is performed according to B method of JISK7142: 2008. Specifically, the first resin layer 3 is pulverized to such an extent that a Becke line can be observed when observed with an optical microscope at a magnification of 400 times. Then, using a halogen lamp provided with a D-line interference filter as a light source, using an optical microscope, observed and measured under conditions of a magnification of 400 times and a temperature of 23 ° C., and refracted the average value of three tests. The value of rate.

  Although it does not restrict | limit especially as thickness per glass fiber fabric 2, For example, about 10-1000 micrometers is mentioned. From the viewpoint of further improving the total light transmittance of the sheet 1, the thickness per sheet of the glass fiber fabric 2 is preferably 20 to 800 μm, more preferably about 30 to 700 μm. In addition, for example, when the sheet 1 of the present invention is used for a daylighting tent, when the visibility through the sheet 1 is emphasized and the haze value is smaller, the per-glass fiber fabric 2 per sheet As thickness, 20-50 micrometers is especially preferable. Further, by setting the thickness of one glass fiber fabric 2 to 20 to 50 μm, the flexibility of the second resin layer 4 and the glass fiber fabric 2 is further approximated, and the second resin layer 4 is made of glass fiber. The first resin layer 3 impregnated in the fabric 2 can be easily followed, and even when bending stress is repeatedly applied, whitening can be further suppressed, and a high total light transmittance can be more easily maintained. In addition, for example, when the sheet 11 of the present invention is used for a lighting cover, when the light diffusibility is important and the haze value is larger, the thickness per piece of the glass fiber fabric 2 is as follows. 50 to 800 μm is particularly preferable.

[First resin layer 3]
In the sheet 1 of the present invention, the first resin layer 3 is included in a state of being impregnated in the glass fiber fabric 2 described above. As described above, the absolute value of the difference between the refractive index of the first resin layer 3 and the refractive index of the glass fiber fabric 2 is preferably 0.05 or less, more preferably 0.04 or less, and particularly preferably 0.03 or less. 0.01 or less is even more preferable. By making the absolute value of the difference in refractive index between the glass fiber fabric 2 and the resin layer 3 0.05 or less, light scattering on the glass fiber surface can be reduced, and the resulting sheet has a higher total light transmittance. Can be obtained.

  The first resin layer 3 contains a resin other than the fluororesin. The first resin layer 3 is preferably a thermoplastic resin having a refractive index of 1.45 to 1.60, or a refraction, from the viewpoint of setting the absolute value of the difference from the refractive index of the glass fiber fabric 2 to 0.05 or less. It is preferable to include a curable resin having a rate of 1.45 to 1.60. Examples of the thermoplastic resin having a refractive index of 1.45 to 1.60 include saturated polyester resin, vinyl chloride resin, acrylic resin (thermoplastic acrylic resin), urethane resin, polycarbonate resin, polyamide resin, and styrene elastomer. Choose from the inside. The curable resin having a refractive index of 1.45 to 1.60 may be selected from, for example, an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, and an acrylic resin (curable acrylic resin). Among these, from the viewpoint of further improving the flexibility of the sheet 1 and more effectively suppressing the occurrence of whitening even when bending stress is repeatedly applied, thermoplasticity having a refractive index of 1.45 to 1.60. Resins are preferred. Moreover, the 1st resin layer 3 can contain multiple types from the said thermoplastic resin and curable resin in order to adjust a refractive index.

  In the case of a laminated structure in which the second resin layer 4 is in contact with the first resin layer 3 (that is, the first resin layer 3 and the second resin layer 4 are directly laminated) From the viewpoint of further improving the adhesion between the first resin layer 3 and the second resin layer 4, the first resin layer 3 is made of vinyl chloride resin, acrylic resin (thermoplastic acrylic resin or curable acrylic resin) or saturated. A polyester resin is preferably included, and a vinyl chloride resin or an acrylic resin is particularly preferable.

  Moreover, it further includes an intermediate layer 5 containing a vinyl chloride resin or an acrylic resin, which will be described later, and is laminated between the first resin layer and the second resin layer so as to be in contact with at least the second resin layer. In the case of a laminated structure, the first resin layer 3 is not particularly limited, but a saturated polyester resin is preferable from the viewpoint of further improving the flexibility and transparency of the sheet. Among these saturated polyester resins, the softening point (Ts) is 20 to 150 ° C., the glass transition point (Tg) is 80 ° C. or less, the number average molecular weight (Mn) is 5000 to 50000 daltons, and the acid value is 0.5 to 500 mgKOH / When the saturated polyester resin of g is contained, the second resin layer 4 is more firmly bonded to the intermediate layer 5 containing the vinyl chloride resin, and the second resin layer 4 becomes easier to follow the first resin layer 3 and is bent. Even when stress is repeatedly applied, whitening is more easily suppressed, and high total light transmittance is more easily maintained.

  From the viewpoint of more effectively maintaining high total light transmittance, the softening point (Ts) of the saturated polyester resin is more preferably 20 to 120 ° C, and further preferably 80 to 120 ° C. The glass transition point (Tg) of the saturated polyester resin is more preferably 75 ° C. or lower and 50 ° C. or higher, and further preferably 70 ° C. or lower and 60 ° C. or higher. From the same viewpoint, the number average molecular weight (Mn) of the saturated polyester resin is more preferably 10,000 to 30,000 daltons, and further preferably 10,000 to 20,000 daltons. The acid value of the saturated polyester resin is more preferably 0.5 to 20 mgKOH / g, and further preferably 0.5 to 5 mgKOH / g.

  In particular, the saturated polyester resin has a softening point (Ts) of 80 to 120 ° C., a glass transition point (Tg) of 75 ° C. or less and 50 ° C. or more, a number average molecular weight (Mn) of 10,000 to 30,000 daltons, and an acid value of 0.1. When 5 to 5 mg KOH / g is satisfied, the second resin layer 4 adheres particularly firmly, and the second resin layer 4 becomes particularly easy to follow the first resin layer 3, and even when bending stress is repeatedly applied, whitening occurs. Can be effectively suppressed. Further, in the first resin layer 3, when a saturated polyester resin having a glass transition point (Tg) of 60 to 120 ° C., more preferably 60 to 80 ° C. is contained, a tension is applied in a high temperature environment such as 50 ° C., for example. Even in the case of using in the above, it becomes easier to further reduce the cloudiness of the sheet, and it becomes easier to maintain the excellent translucency. Examples of the softening point (Ts) of the saturated polyester resin having a glass transition point (Tg) of 60 to 120 ° C. include 100 to 220 ° C., preferably 150 to 180 ° C., and the number average molecular weight (Mn) is For example, 10000-30000 dalton is mentioned, Preferably it is 14000-22000 dalton, As an acid value, 0.5-20 mgKOH / g, for example, Preferably it is 1-15 mgKOH / g.

  In the present invention, Ts (° C.) is a value measured according to the JIS K 2531: 1960 ring and ball method. Tg (° C.) is a glass transition point (from the chart scanned at a heating rate of 10 ° C./min using an input-compensated differential scanning calorimeter (Diamond DSC manufactured by Perkin Elmer) according to JIS K 7121. Tg) (extrapolated glass transition start temperature (° C.)). Mn is a value measured by the VPO method (vapor pressure osmotic pressure method). The acid value was determined by dissolving 0.5 g of saturated polyester resin in 50 ml of water / dioxane = 1/9 (volume ratio), titrating with KOH using cresol red as an indicator, and calculating the number of mg of KOH consumed for neutralization. The value calculated per 1 g of saturated polyester resin is a value obtained as an acid value.

  In the 1st resin layer 3, as a ratio of resin other than a fluororesin, 50-100 mass% is preferable, for example, and 70-100 mass% is more preferable.

Although it does not restrict | limit especially as a mass of the 1st resin layer 3, From a viewpoint of improving translucency and nonflammability further, 30-500 g / m < ² > is preferable, for example, and 30-300 g / m. ² is more preferable, and 30 to 100 g / m ² is still more preferable.

  The 1st resin layer 3 may further contain additives, such as a flame retardant, an ultraviolet absorber, a filler, an antistatic agent, and a light diffusing agent, as needed other than resin other than fluororesin. Examples of the flame retardant include aluminum hydroxide, magnesium hydroxide, trichloroethyl phosphate, triallyl phosphate, ammonium polyphosphate, and phosphate ester. Examples of the ultraviolet absorber include benzotriazole. Examples of the filler include calcium carbonate, silica, and talc. Examples of the antistatic agent include a surfactant. Examples of the light diffusing agent include colloidal silica and transparent microspheres such as glass beads and acrylic beads. These additives may be used individually by 1 type, and may be used in combination of 2 or more types.

  The thickness (L0) of the first resin layer 3 is preferably set as appropriate so as to satisfy the above-described formulas (I) and (II), but specifically 30 to 300 μm, preferably 30 to 100 μm. Is mentioned.

[Second resin layer 4]
In the sheet 1 of the present invention, the second resin layer 4 is a layer disposed on at least one surface side of the first resin layer 3 and includes a fluororesin and an acrylic resin, and the fluororesin is polyvinylidene fluoride ( Hereinafter, it may be abbreviated as “PVDF”.

  Examples of the acrylic resin contained in the second resin layer 4 include poly (meth) methyl acrylate (PMMA), poly (meth) ethyl acrylate, poly (meth) acrylate propyl, poly (meth) acrylate butyl, (Meth) methyl acrylate- (meth) butyl acrylate copolymer, (meth) ethyl acrylate- (meth) butyl acrylate copolymer, ethylene- (meth) methyl acrylate copolymer, styrene- (meta ) A resin comprising a homopolymer or a copolymer containing a (meth) acrylic acid ester such as a methyl acrylate copolymer. Among these, PMMA is preferable from the viewpoint of further improving the adhesion with the first resin layer 3 and the intermediate layer 5.

  From the viewpoint of further exerting weather resistance and antifouling properties by PVDF and adhesion to the first resin layer 3 or the intermediate layer 5 by acrylic resin, the second resin layer 4 has a PVDF rich surface (that is, containing PVDF). The surface to be bonded to the first resin layer 3 or the intermediate layer 5 is an acrylic resin-rich surface, including an acrylic resin-rich surface (that is, an acrylic resin content of 51 mass% or more). Preferably there is. As mass ratio (PVDF: acrylic resin) of PVDF and an acrylic resin in the said PVDF rich surface, 51: 49-95: 5 is mentioned preferably, for example, and 60: 40-90: 10 is mentioned more preferably. Moreover, as mass ratio (PVDF: acrylic resin) of PVDF and an acrylic resin in the said acrylic resin rich surface, 5: 95-49: 51 is mentioned preferably, for example, 10: 90-40: 60 is mentioned more preferably. . As described above, the second resin layer 4 includes a PVDF rich surface (that is, the PVDF content is 51% by mass or more) and an acrylic resin rich surface (that is, the acrylic resin content is 51% by mass or more). As, for example, an alloy of PVDF and an acrylic resin, and a sheet A having a PVDF content of 51% by mass or more and a sheet B having an acrylic resin content of 51% by mass or more are prepared. The method of joining this sheet | seat A and this sheet | seat B is mentioned.

  From the viewpoint that the first resin layer 3 and the second resin layer 4 are less likely to be peeled off even when used for a long time in an environment where ultraviolet rays are irradiated, such as outdoors, in addition to the fluororesin, If necessary, an ultraviolet absorber can be included. The ultraviolet absorber may be either organic or inorganic, and if it is organic, for example, benzophenone, benzotriazole, triazine, cyanoacrylate, oxalinide, salicylate, acrylic And other ultraviolet absorbers. Moreover, the 2nd resin layer 4 can also contain a ultraviolet-ray shielding agent from the same viewpoint. Preferred examples of the ultraviolet shielding agent include zinc oxide, titanium oxide, cerium oxide and the like because of their photocatalytic activity. These ultraviolet absorbers and ultraviolet shielding agents may be kneaded into the second resin layer 4 or applied to the surface of the second resin layer 4.

  In addition, the second resin layer may contain additives such as colored pigments such as organic pigments and inorganic pigments, dyes, and infrared absorbers, if necessary.

The mass per layer of the second resin layer 4 is not particularly limited, but is preferably 22 to 435 g / m ² , for example, from the viewpoint of further improving translucency and incombustibility. -200 g / m < ² > is more preferable, and 22-150 g / m < ² > is still more preferable.

  In addition, the thickness per layer of the second resin layer 4 is not particularly limited. For example, the light transmission is further improved, and flexibility is added to repeatedly apply bending stress. However, 12.5 to 500 μm is preferable and 12.5 to 250 μm is more preferable from the viewpoint of suppressing whitening and making it easier to maintain excellent translucency. In addition, from the viewpoint of easily providing excellent nonflammability characteristics while setting the thickness of the entire sheet to 500 μm or more, the thickness per layer of the second resin layer 4 is preferably 10 to 120 μm.

[Middle layer 5]
The intermediate layer 5 is a layer provided between the first resin layer 3 and the second resin layer 4 as necessary, for example, for the purpose of improving their adhesion.

  The intermediate layer 5 is preferably provided in a state in contact with the second resin layer 4 from the viewpoint of further reducing the peeling of the second resin layer 4. Further, from the viewpoint of further improving the adhesion between the first resin layer 3 and the second resin layer 4 and making it more difficult to cause whitening when the sheet is folded, the intermediate layer is formed as shown in FIG. 3, for example. It is preferable to provide a laminated structure in which the first resin layer 3, the intermediate layer 5, and the second resin layer 4 are laminated in order.

It is preferable that the intermediate | middle layer 5 contains a vinyl chloride resin or an acrylic resin from a viewpoint of improving the adhesiveness of the 1st resin layer 3 and the 2nd resin layer 4 more. When the intermediate layer 5 includes a vinyl chloride resin or an acrylic resin, the significance of providing the intermediate layer 5 further increases as the first resin layer includes a resin other than a fluororesin, a vinyl chloride resin, and an acrylic resin. In particular, when the intermediate layer 5 includes a vinyl chloride resin, the adhesiveness between the first resin layer 3 and the second resin layer 4 can be further improved, and the vinyl chloride resin is excellent in flame retardancy. Since the non-flammability performance measured according to the exothermic test / evaluation method described later tends to be excellent, the obtained sheet easily satisfies the non-flammability and is effectively defined in the Ministry of Land, Infrastructure, Transport and Tourism Notification No. 666. It becomes easy to satisfy the standard of thickness 0.5 mm or more which is one of the performance standards of the film material. Among them, when the intermediate layer 5 is composed of a vinyl chloride resin, it is easy to increase the thickness of the sheet itself while suitably maintaining excellent nonflammability, and from the viewpoint of being more suitable as a film material, The mass A (g / m ² ) of the first resin layer 3 excluding the glass fiber fabric, the mass B (g / m ² ) of the entire second resin layer 4, and the mass C (g / m ² ) of the entire intermediate layer 5 The ratio (A: B: C) is preferably 100: 500 to 1300: 400 to 1200, more preferably 100: 700 to 1100: 600 to 1000.

Although it does not restrict | limit especially as a mass per one layer of the intermediate | middle layer 5, From a viewpoint of improving translucency and nonflammability further, for example, 5-300 g / m < ² > is preferable, and 10-250 g. / M ² is more preferable, and 80 to 200 g / m ² is particularly preferable. The thickness per layer of the intermediate layer 5 is not particularly limited, but is preferably 50 to 200 μm, and more preferably 70 to 130 μm, for example. Moreover, from a viewpoint of improving the handleability as film | membrane material, the intermediate | middle layer 5 shall contain a vinyl chloride resin, and the thickness per layer of the intermediate | middle layer 5 has more preferable 100-300 micrometers.

[Reticulated layer 6]
The net layer 6 is a layer provided as needed between the first resin layer 3 and the second resin layer 4 for the purpose of increasing the nonflammability of the sheet 1 or increasing the mechanical strength. .

  The net layer 6 is formed of a glass fiber net. Although it does not restrict | limit especially as a glass fiber network which comprises the net body layer 6, For example, the same glass fiber network as the glass fiber illustrated with the glass fiber fabric 2 can be illustrated. Further, the shape and structure of the glass fiber network are not particularly limited, and examples thereof include a glass fiber orthogonal laminated net in which a weft is sandwiched between two warps and fixed with a resin. The glass fiber network constituting the net body layer 6 can be well-lighted through the openings between the glass fibers by setting the opening width between the glass fibers to preferably 3 to 20 mm, and the strength of the entire sheet 1 can be increased. It becomes possible to increase. Further, if the second resin layer 4 is provided on both sides of the first resin layer 3, the first resin layer 3 and the second resin layer 4 can be formed from the viewpoint of enhancing nonflammability and mechanical strength. It is preferable to arrange | position the network body layer 6 (namely, two network body layers 6) in each between.

  The thickness per layer of the network layer 6 is not particularly limited, but may be about 50 to 300 μm, preferably about 100 to 200 μm, for example.

Total light transmittance and nonflammability characteristics The sheet 1 of the present invention preferably has a high total light transmittance, for example, when applied to a roofing material or the like that is lit from the outside to the inside. From the viewpoint of making it easier to ensure a high total light transmittance, the total light transmittance of the sheet 1 of the present invention is preferably 70% or more, more preferably 80% or more, still more preferably 85% or more, and more than 90%. Particularly preferred. By satisfying such a total light transmittance, for example, when used as a roofing material of a building, a tent warehouse material or the like, it is possible to increase the amount of light collected from outside to inside. In order to increase the total light transmittance, the absolute value of the difference between the refractive index of the glass fiber fabric 2 and the refractive index of the first resin layer 3 is set to 0.05 or less, for example, the glass fiber fabric 2 is configured. The glass fiber fabric and the first resin layer 3 with a small fiber diameter, count, thickness of the glass fiber fabric, etc. to increase the smoothness of the glass fiber fabric or to reduce the woven density. This can be achieved by adjusting the ratio of the glass fiber fabric 2 to the total amount.

  In addition, the haze of the sheet 1 of the present invention is preferably 60% or less, more preferably 50% or less, when visibility through the sheet is important, for example, when used in a lighting tent or the like. % Or less is more preferable. For example, when the light diffusibility is important, such as when used for a lighting cover, the haze of the sheet 1 of the present invention is preferably 60% or more, more preferably 70% or more, and particularly preferably 80% or more. . In order to increase the haze, techniques such as increasing the fiber diameter of the glass fibers constituting the glass fiber fabric 2 and increasing the weave density can be used. Further, the haze can be increased by dispersing glass beads in the first resin layer 3. In the present invention, the total light transmittance and haze of the sheet 1 are values obtained by measurement according to JIS K7375 2008 “Plastics—How to obtain total light transmittance and total light reflectance”, respectively.

Since the sheet 1 of the present invention includes the glass fiber fabric 2 and the second resin layer 4, the sheet 1 can be provided with a property that does not easily burn (nonflammability). In addition, as the nonflammability of the sheet 1 of the present invention, 4.10.2 exothermic property in the “Fireproofing Performance Test / Evaluation Business Method Manual” (modified on March 1, 2014) of the Building Materials Testing Center, Japan In an exothermic test in which the surface of the sheet is irradiated with 50 kW / m ² of radiant heat measured according to the test / evaluation method, the maximum heat generation rate after the start of heating continues for 10 seconds or more to reach 200 kW / m ² . It is preferable that the total calorific value is 8 MJ / m ² or less. In order to further improve the incombustibility, for example, in the first resin layer 3 and / or the second resin layer 4, a flame retardant may be added, the amount of organic substances may be reduced, and the like.

  In the sheet 1 of the present invention, since the second resin layer 4 contains a polyvinylidene fluoride resin and an acrylic resin, the fluororesin layer is hardly peeled off. In addition, as peeling strength of the 2nd resin layer of the sheet | seat 1 of this invention, the peeling strength measured according to JISK6854-2: 1999 is preferable 20N / 25mm or more, and 40N / 25mm or more is more preferable.

  The thickness of the sheet 1 of the present invention is not particularly limited, but from the viewpoint of satisfying the performance standard of the membrane material defined in 2002 Ministry of Land, Infrastructure, Transport and Tourism Notification No. 666, the thickness which is one of the performance standards is It is preferable to be 0.5 mm or more. Moreover, 0.5-2.0 mm is more preferable from the viewpoint which makes it easy to ensure a high total light transmittance more, and it is especially preferable to set it as 0.5-1.0 mm.

Production method The production method of the sheet 1 of the present invention is not particularly limited. For example, the first step of preparing an intermediate body in which the glass fiber fabric 2 is impregnated with the first resin layer 3, the first resin of the intermediate body After the intermediate layer 5 and / or the network layer 6 are laminated on the layer 3 as necessary, it can be manufactured through a second step of laminating the second resin layer.

  In the first step, first, a raw material liquid containing the glass fiber fabric 2 and a resin that forms the first resin layer 3 is prepared. Next, after applying and impregnating the raw material liquid to the glass fiber fabric 2, the thickness and the resin content are adjusted using a squeeze roller or the like. Next, the resin is cured by applying heating energy, light energy, or the like, or the solvent is evaporated by heating to obtain an intermediate body in which the glass fiber fabric 2 is impregnated with the first resin layer 3. In addition, a film such as polyethylene terephthalate coated with a raw material solution containing the resin is prepared, and the film is pressure-bonded from both sides of the glass fiber fabric 2 to impregnate the resin from both sides of the glass fiber fabric 2 to cure the resin. After evaporating the solvent, the intermediate body in which the glass fiber fabric 2 is impregnated with the first resin layer 3 can be obtained by peeling the film.

In the first step, when the resin is cured by applying thermal energy, the heating temperature is not particularly limited, but may be about 50 to 200 ° C., for example. Moreover, what is necessary is just to irradiate light to the said resin, when hardening the said resin by provision of light energy. Examples of the light irradiation condition include an integrated light amount of 100 to 500 mJ / cm ² .

  In the second step, the method of laminating the second resin layer 4 on the intermediate first resin layer 3 obtained in the first step is not particularly limited. For example, a fluororesin dispersion is used. A method of applying to the first resin layer 3 of the intermediate, drying and baking; placing a sheet formed of a fluororesin on the first resin layer 3 of the intermediate, and then heating using a press or the like The method etc. which adhere | attach by pressurizing are mentioned. Further, when the intermediate layer 5 and / or the network layer 6 is disposed between the first resin layer 3 and the second resin layer 4, for example, on the first resin layer 3 of the intermediate body. After the intermediate layer 5 is applied, the network layer 6 is disposed thereon, and a sheet formed of a fluororesin is disposed on the network layer 6, and then heated and pressurized using a press machine or the like. Thus, the net layer 6 and the second resin layer 4 can be formed on the first tree resin layer 3. Also. When the intermediate layer 5 includes a thermoplastic resin, the intermediate layer 5 formed in the form of a sheet or film is disposed on the first resin layer 3, and the sheet of the second resin layer is disposed on the intermediate layer 5. Is placed on the first resin layer 3 by using a press machine or the like at a temperature equal to or higher than the melting point or softening point of the first resin layer 3 and the intermediate layer 5. Two resin layers 4 can be laminated.

  In the second step, when the second resin layer 4 is laminated using a sheet formed of a fluororesin, the sheet has an adhesive property such as an etching process, a plasma process, a corona process, or a photochemical process. Processing to improve may be performed.

Application Since the sheet 1 of the present invention is excellent in translucency, it is suitable for film materials such as building roof materials and tent warehouse materials (particularly including film materials used in daylighting tents), lighting covers and the like. Can be used.

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

1. Production of Sheet As a glass fiber fabric, commercially available glass fiber fabrics (glass material: E glass, specific gravity 2.54 g / cm ³ ) described in Table 2 were cut into 200 mm × 200 mm and used. In Table 2, “E03R SK” is a trade name of E glass fiber fabric manufactured by Unitika Ltd. The E glass fiber fabric is subjected to a heat treatment for removing organic substances and a surface treatment with a silane coupling agent. The glass material used in Examples 1 to 3 and Comparative Examples 1 to 3 had a glass volume ratio of 39.4%.

  The resin composition for forming the first resin layer impregnated into the glass fiber fabric is a mixture of a commercially available curable acrylic resin and a photopolymerization initiator (refractive index of 1.56) so as to have the composition shown in Table 2. ), Saturated polyester resin ("Eritel UE-3200G" (manufactured by Unitika Co., Ltd., refractive index 1.56)), vinyl ester resin (manufactured by Nippon Yupica Co., Ltd., trade name "Neopol 8114") and styrene monomer (Nihon Iupika Co., Ltd.), a mixture of bifunctional (meth) acrylate and photopolymerization initiator (refractive index 1.56) was used. In addition, as bifunctional (meth) acrylate which is a hardening | curing agent, NPGDA (Neopentylglycol diacrylate, the molecular weight 212, (made by Nippon Iupica Co., Ltd.) of Table 2 was used. Is 1 part by mass with respect to 100 parts by mass of the curable acrylic resin, and 2 parts by mass with respect to 100 parts by mass in total of the vinyl ester resin, the styrene monomer, and the bifunctional (meth) acrylate. The physical properties are shown in Table 1 below.

As a sheet for forming the second resin layer, a sheet containing PVDF and an acrylic resin (PVDF and PMMA alloy having a PVDF content of 80 mass% and a PMMA content of 20 mass% And a sheet formed by bonding a sheet B having a PVDF content of 20 mass% and a PMMA content of 80 mass% (manufactured by Denka Co., Ltd., trade name “DENKA DX film DX-14S100”, thickness 100 μm) , Mass 136 g / m ² )), and a sheet consisting only of PVDF (thickness 100 μm, mass 174 g / m ² ).

As the resin for forming the intermediate layer, a vinyl chloride resin film (manufactured by Okamoto Co., Ltd., PVC # 320 for general use, thickness 100 μm, mass 120 g / m ² ), saturated polyester resin (as shown in Table ² ) was used. “Elitel UE-3400” (manufactured by Unitika Ltd.) was used.

Example 1
First, the resin composition which forms the 1st resin layer of the quantity (g / m < ² >) of Table 2 on the 0.05-mm-thick PET film was apply | coated. Next, the glass fiber fabric described in Table 2 was placed on the resin composition and allowed to stand for 1 minute to impregnate the resin composition in the gaps of the glass fiber fabric. Next, a PET film having a thickness of 0.05 mm was placed from above, and pressure was applied from above with a roller. Thereafter, for each of the above PET films, the resin composition is irradiated with light (light irradiation condition: accumulated light quantity 200 mJ / cm ² ) to cure the resin composition, thereby forming a first resin layer (curable acrylic resin). An intermediate sheet comprising a glass fiber fabric and a first resin layer (cured product of a curable acrylic resin) impregnated in the glass fiber fabric was obtained.

Next, the obtained intermediate sheet is composed of two sheets containing the PVDF and the acrylic resin described above, and both of the two sheets are bonded to the first resin layer on the sheet B side (that is, the acrylic resin rich surface). ) And press with a heating press machine at a temperature of 160 ° C., a press pressure of 10 kgf / cm ² , and a time of 5 minutes, and by bonding an intermediate sheet, a sheet containing PVDF and acrylic resin, A glass fiber fabric, a first resin layer (cured product of a curable acrylic resin) impregnated in the glass fiber fabric, and a second resin layer containing a polyvinylidene fluoride resin and an acrylic resin on both sides of the first resin layer. A sheet of the present invention having a laminated structure was obtained.

In the obtained sheet, the first resin layer (curable acrylic resin) had a mass of 30 g / m ² and a thickness (L0) of 60 μm. Moreover, in the obtained sheet | seat, the 1st resin layer was impregnated in the clearance gap between the glass fibers of a glass fiber fabric, and the 1st resin layer was formed on both surfaces of the layer of a glass fiber fabric.

(Example 2)
First, on a PTFE sheet for release, 100 g / m ^{2 of} a solution in which Unitika Eritel UE-3200G was dissolved in a toluene / MEK mixed solvent (ratio 8/2) to a solid content of 30% was applied. . Next, the glass fiber fabric described in Table 2 was placed on the applied saturated polyester resin solution and allowed to stand for 1 minute to impregnate the above resin in the gaps of the glass fiber fabric. Next, in order to volatilize the solvent in the applied saturated polyester resin solution, heat treatment was performed in two stages of 70 ° C. for 8 minutes and 120 ° C. for 8 minutes in a dryer, and the saturated polyester resin impregnated into the glass fiber fabric was It turned into a film. Thereafter, the PTFE sheet was peeled off. Next, both sides of the film-formed saturated polyester resin are sandwiched between the two vinyl chloride resin films described above that form the intermediate layer, and are heated at a temperature of 150 ° C., a press pressure of 10 kgf / cm ² , and a time of 5 minutes. The saturated polyester resin layer impregnated into the glass fiber fabric and the vinyl chloride resin film were bonded. And both surfaces of the sheet | seat which the saturated polyester resin layer and vinyl chloride resin film which impregnated the glass fiber fabric adhere | attached are 2 sheets | sheets containing the above-mentioned PVDF and an acrylic resin, and both of these sheet | seats are adhere | attached with the said intermediate | middle layer. Sandwiched so that the surface to be sheet B side (that is, the acrylic resin-rich surface) is pressed with a heating press machine at a temperature of 160 ° C., a pressing pressure of 10 kgf / cm ² , and a time of 5 minutes. The glass fiber fabric, the first resin layer (saturated polyester resin) impregnated in the glass fiber fabric, and the intermediate layer (vinyl chloride) on both surfaces of the first resin layer are bonded to each other. A sheet of the present invention having a laminated structure in which a second resin layer containing a polyvinylidene fluoride resin and an acrylic resin is laminated via a resin) is obtained.

In the obtained sheet, the mass of the first resin layer (saturated polyester resin) was 30 g / m ² , and the thickness (L0) was 60 μm. Further, in the obtained sheet, the gap between the glass fibers of the glass fiber fabric is impregnated with the first resin layer (saturated polyester resin), and the first resin layer (on the both sides of the glass fiber fabric layer) Saturated polyester resin) was formed. Moreover, the mass A (g / m ² ) of the first resin layer (saturated polyester resin) excluding the glass fiber fabric, the mass B (g / m ² ) of the entire second resin layer, and the mass C (g of the entire intermediate layer) / M ² ) ratio (A: B: C) was 100: 900: 800.

(Example 3)
First, the resin composition which forms the 1st resin layer of the quantity (g / m < ² >) of Table 2 on the 0.05-mm-thick PET film was apply | coated. Next, the glass fiber fabric described in Table 2 was placed on the resin composition and allowed to stand for 1 minute to impregnate the resin composition in the gaps of the glass fiber fabric. Next, a PET film having a thickness of 0.05 mm was placed from above, and pressure was applied from above with a roller. Thereafter, for each of the above PET films, the resin composition is irradiated with light (light irradiation condition: accumulated light quantity 200 mJ / cm ² ) to cure the resin composition, and the first resin layer (containing a vinyl ester resin and a styrene monomer) is formed. An intermediate sheet formed from a glass fiber fabric and a first resin layer (cured material such as vinyl ester resin) impregnated in the glass fiber fabric was obtained.

Next, in order to form an intermediate layer on the surface of the sheet containing PVDF and acrylic resin on the sheet B side (that is, on the acrylic resin rich surface), Unitika Eritel UE-3400 is mixed with a toluene / MEK mixed solvent. 50 g / m ^{2 of} a solution dissolved in (ratio 8/2) so as to have a solid content of 30% was applied, and the intermediate sheet was placed on the applied saturated polyester resin solution. Further, in order to form an intermediate layer also on the upper surface side of the intermediate sheet, a solution obtained by dissolving Unitika Eritel UE-3400 in a toluene / MEK mixed solvent (ratio 8/2) so as to have a solid content of 30%. Was applied at 50 g / m ² . Subsequently, in order to volatilize the solvent in the applied saturated polyester resin solution, heat treatment was performed in two stages of 70 ° C. for 8 minutes and 120 ° C. for 8 minutes in a dryer to form a film of the saturated polyester resin. On the saturated polyester resin filmed on the upper surface side of the intermediate sheet, one sheet containing the PVDF and the acrylic resin is bonded to the intermediate layer (the filmed saturated polyester resin). Placed on the B side (that is, the acrylic resin rich surface), pressed with a roller from above the sheet containing the PVDF and the acrylic resin, and the sheet containing the PVDF and the acrylic resin and a saturated polyester resin formed into a film The air bubbles are removed, and the sheet containing PVDF and acrylic resin and the intermediate sheet are saturated polyester resin by pressing with a heat press machine at a temperature of 160 ° C., a press pressure of 10 kgf / cm ² , and a time of 5 minutes. Glass fiber fabric and the first resin layer impregnated in the glass fiber fabric (vinyl ester resin or the like) Cured product) and a laminated structure in which sheets including PVDF and acrylic resin are laminated on both sides of the first resin layer via intermediate layers (saturated polyester resin, thickness of 15 μm per layer). Got the sheet.

In the obtained sheet, the mass of the first resin layer was 30 g / m ² , and the thickness (L0) was 60 μm. Further, in the obtained sheet, a gap between the glass fibers of the glass fiber cloth is impregnated with the first resin layer (cured product of vinyl ester resin and styrene monomer), on both surfaces of the glass fiber cloth layer. The first resin layer (cured product such as vinyl ester resin) was formed.

(Comparative Example 1)
First, the resin composition which forms the 1st resin layer of the quantity (g / m < ² >) of Table 2 on the 0.05-mm-thick PET film was apply | coated. Next, the glass fiber fabric described in Table 2 was placed on the resin composition and allowed to stand for 1 minute to impregnate the resin composition in the gaps of the glass fiber fabric. Next, a PET film having a thickness of 0.05 mm was placed from above, and pressure was applied from above with a roller. Thereafter, for each of the above PET films, the resin composition is irradiated with light (light irradiation condition: accumulated light quantity 200 mJ / cm ² ) to cure the resin composition, thereby forming a first resin layer (curable acrylic resin). An intermediate sheet comprising a glass fiber fabric and a first resin layer (cured product of a curable acrylic resin) impregnated in the glass fiber fabric was obtained.

Next, the obtained intermediate sheet is sandwiched between two sheets made only of the above-mentioned PVDF, and is pressed with a heating press machine at a temperature of 160 ° C., a press pressure of 10 kgf / cm ² , and a time of 5 minutes. Glass fiber fabric, a first resin layer impregnated in the glass fiber fabric (cured product of curable acrylic resin), and only PVDF on both surfaces of the first resin layer The sheet | seat which is the laminated structure on which the sheet | seat which consists of was laminated | stacked was obtained.

In the obtained sheet, the first resin layer (curable acrylic resin) had a mass of 30 g / m ² and a thickness (L0) of 60 μm. Moreover, in the obtained sheet | seat, the 1st resin layer was impregnated in the clearance gap between the glass fibers of a glass fiber fabric, and the 1st resin layer was formed on both surfaces of the layer of a glass fiber fabric.

(Comparative Example 2)
First, on a PTFE sheet for release, 100 g / m ^{2 of} a solution in which Unitika Eritel UE-3200G was dissolved in a toluene / MEK mixed solvent (ratio 8/2) to a solid content of 30% was applied. . Next, the glass fiber fabric described in Table 2 was placed on the applied saturated polyester resin solution and allowed to stand for 1 minute to impregnate the above resin in the gaps of the glass fiber fabric. Next, in order to volatilize the solvent in the applied saturated polyester resin solution, heat treatment was performed in two stages of 70 ° C. for 8 minutes and 120 ° C. for 8 minutes in a dryer, and the saturated polyester resin impregnated into the glass fiber fabric was It turned into a film. Thereafter, the PTFE sheet was peeled off. Next, both sides of the film-formed saturated polyester resin are sandwiched between the two vinyl chloride resin films described above that form the intermediate layer, and are heated at a temperature of 150 ° C., a press pressure of 10 kgf / cm ² , and a time of 5 minutes. The saturated polyester resin layer impregnated into the glass fiber fabric and the vinyl chloride resin film were bonded. Then, both sides of the sheet on which the saturated polyester resin layer impregnated into the glass fiber fabric and the vinyl chloride resin film are bonded are sandwiched between the two sheets made only of the above-mentioned PVDF, and the temperature is 160 ° C., the pressing pressure is 10 kgf / A glass fiber cloth and a first resin layer (saturated polyester resin) impregnated in the glass fiber cloth by pressing the sheet under the condition of cm ² for 5 minutes to adhere the vinyl chloride resin film and the sheet made of PVDF alone. And the sheet | seat which is a laminated structure by which the sheet | seat which consists only of PVDF was laminated | stacked on both surfaces of this 1st resin layer through the intermediate | middle layer (vinyl chloride resin) was obtained.

In the obtained sheet, the mass of the first resin layer (saturated polyester resin) was 30 g / m ² , and the thickness (L0) was 60 μm. Further, in the obtained sheet, the gap between the glass fibers of the glass fiber fabric is impregnated with the first resin layer (saturated polyester resin), and the first resin layer (on the both sides of the glass fiber fabric layer) Saturated polyester resin) was formed.

(Comparative Example 3)
First, the resin composition which forms the 1st resin layer of the quantity (g / m < ² >) of Table 2 on the 0.05-mm-thick PET film was apply | coated. Next, the glass fiber fabric described in Table 2 was placed on the resin composition and allowed to stand for 1 minute to impregnate the resin composition in the gaps of the glass fiber fabric. Next, a PET film having a thickness of 0.05 mm was placed from above, and pressure was applied from above with a roller. Thereafter, for each of the above PET films, the resin composition is irradiated with light (light irradiation condition: accumulated light quantity 200 mJ / cm ² ) to cure the resin composition, and the first resin layer (containing a vinyl ester resin and a styrene monomer) is formed. An intermediate sheet formed from a glass fiber fabric and a first resin layer (cured material such as vinyl ester resin) impregnated in the glass fiber fabric was obtained.

Next, in order to form an intermediate layer on the surface of the above-mentioned sheet consisting only of PVDF, Unitika Eritel UE-3400 is dissolved in a toluene / MEK mixed solvent (ratio 8/2) so as to have a solid content of 30%. 50 g / m ^{2 of} the solution was applied, and the intermediate sheet was placed on the applied saturated polyester resin solution. Further, in order to form an intermediate layer also on the upper surface side of the intermediate sheet, a solution obtained by dissolving Unitika Eritel UE-3400 in a toluene / MEK mixed solvent (ratio 8/2) so as to have a solid content of 30%. Was applied at 50 g / m ² . Subsequently, in order to volatilize the solvent in the applied saturated polyester resin solution, heat treatment was performed in two stages of 70 ° C. for 8 minutes and 120 ° C. for 8 minutes in a dryer to form a film of the saturated polyester resin. On the saturated polyester resin filmed on the upper surface side of the intermediate sheet, one sheet made of only the PVDF is placed, and the sheet made of only the PVDF is pressed with a roller from above the sheet made of only the PVDF. And intermediate sheet with the PVDF only sheet removed by air bubbles between the film and the saturated polyester resin formed into a film, and pressed with a hot press machine at a temperature of 160 ° C., a press pressure of 10 kgf / cm ² , and a time of 5 minutes. Are bonded via a saturated polyester resin, a glass fiber fabric, a first resin layer (cured product such as vinyl ester resin) impregnated in the glass fiber fabric, and an intermediate layer on both sides of the first resin layer A sheet having a laminated structure in which sheets made only of PVDF are laminated via (saturated polyester resin, thickness of 15 μm per layer) Got.

In the obtained sheet, the mass of the first resin layer was 30 g / m ² , and the thickness (L0) was 60 μm. Further, in the obtained sheet, a gap between the glass fibers of the glass fiber cloth is impregnated with the first resin layer (cured product of vinyl ester resin and styrene monomer), on both surfaces of the glass fiber cloth layer. The first resin layer (cured product such as vinyl ester resin) was formed.

  In the examples, the weave density of the glass fiber fabric was measured and calculated according to JIS R 3420 2013 7.9. Moreover, the thickness of the glass fiber fabric was measured and calculated according to JIS R 3420 2013 7.10.1A method. The mass of the glass fiber fabric was measured and calculated according to JIS R 3420 2013 7.2. The refractive indexes of the first resin layer and the glass fiber fabric were measured and calculated by the above method. The following evaluation was performed after the sheet was manufactured and left in the room for one week.

2. Sheet performance evaluation

(Total light transmittance and haze)
Measured according to JIS K7361-1 1997 “Plastics—Testing method of total light transmittance of transparent material—Part 1: Single beam method”. The haze was measured according to JIS K7136 2000 “Plastics—How to determine haze of transparent material”.

(Evaluation of nonflammability)
Using each sheet obtained in Examples 1 and 2 and Comparative Examples 1 and 2, fire resistance test method and performance evaluation standard based on Article 2-9 of Building Standard Law and Article 108-2 of Building Standard Law Enforcement Ordinance Exothermic test using a corn calorimeter test machine according to the above, and the maximum heat generation rate after the start of heating continues for 10 seconds or more and does not exceed 200 kW / m ² , and the total calorific value is 8 MJ / m ² or less Was marked as ○.

(Peel strength)
According to JIS K 6854-2: 1999, the 2100 type made by INTESCO was used as a tensile tester, and the obtained sheets were cut to a width of 25 mm and a length of 500 mm. A test piece was prepared by peeling two resin layers (fluororesin layer) 50 mm in the length direction. In each example and comparative example, five test pieces were prepared. Only the fluororesin layer at one end of the test piece is gripped by the upper grip of the tensile tester, and other than the second resin layer (fluororesin layer) at the other end of the test strip by the lower grip of the tensile tester The test was conducted with the gripping movement speed set at 100 mm / min, and the average peel force (N / 25 mm) was determined from the obtained force-grasping movement curve, and this was performed on the five test pieces. The average value of the average peel force of the five test pieces was defined as the peel strength (N / 25 mm).

  The results are shown in Table 2.

  The sheets of Examples 1 to 3 exhibited an effect that the fluororesin layer was hardly peeled off because the fluororesin layer contained a polyvinylidene fluoride resin and an acrylic resin. In particular, in Examples 1 and 2 in which the resin layer with which the second resin layer was in contact was a vinyl chloride resin or an acrylic resin, the second resin layer did not peel in the peel test, and the second resin layer was materially destroyed. As described above, peeling of the fluororesin layer is more difficult to occur. Moreover, since the intermediate | middle layer contained the vinyl chloride resin, it turned out that the sheet | seat of Example 2 becomes easy to enlarge thickness, maintaining the outstanding peeling strength and nonflammability. Moreover, since Example 1 or Example 3 was compared with Example 2 and Example 2 was the 1st resin layer being a thermoplastic resin layer, even if bending stress is added repeatedly, whitening is carried out. It was what suppressed generation | occurrence | production more effectively. In addition, the sheet of Example 2 has a tension (N / N) of 1/10 of the sheet tensile strength (N / 25 mm) measured in accordance with JIS R 3420 2013 type II in the warp direction under an environment at an ambient temperature of 50 ° C. ), The sheet is not clouded at all due to the glass transition of the first resin layer, and even when used under tension in a high temperature environment, the translucency is further improved. It was easier to maintain.

  On the other hand, in Comparative Examples 1 to 3, the fluororesin layer did not contain a polyvinylidene fluoride resin and an acrylic resin, but consisted only of the polyvinylidene fluoride resin. In comparison, the effect that peeling of the fluororesin layer hardly occurs was inferior.

1 sheet 2 glass fiber fabric 3 first resin layer 4 second resin layer 5 intermediate layer 6 network layer

Claims (13)

At least one glass fiber fabric;
A first resin layer contained in a state impregnated in the glass fiber fabric;
A second resin layer laminated on at least one surface side of the first resin layer,
The first resin layer includes a resin other than a fluororesin,
The sheet, wherein the second resin layer includes a fluororesin and an acrylic resin, and the fluororesin is polyvinylidene fluoride.   The sheet according to claim 1, wherein an absolute value of a difference in refractive index between the glass fiber fabric and the first resin layer is 0.05 or less.   The sheet according to claim 1 or 2, wherein the resin contained in the first resin layer is a thermoplastic resin.   The sheet | seat of any one of Claims 1-3 in which the resin layer laminated | stacked in the state which the said 2nd resin layer contacted contains a vinyl chloride resin, an acrylic resin, or a saturated polyester resin.   The sheet according to claim 4, wherein the resin layer laminated in a state where the second resin layer is in contact with the second resin layer is the first resin layer.   The intermediate layer is further included between the 1st resin layer and the 2nd resin layer, and the resin layer laminated in the state where the 2nd resin layer touched is the intermediate layer. Sheet.   The sheet according to claim 6, wherein the resin contained in the first resin layer and the resin contained in the intermediate layer are different resins.   The sheet according to claim 6 or 7, further comprising the intermediate layer and a network layer made of a glass fiber network between the first resin layer and the second resin layer.   The sheet | seat of any one of Claims 1-8 whose ratio of the said glass fiber fabric with respect to the total amount of the said glass fiber fabric and the said 1st resin layer is 10-70 mass%.   The sheet | seat of any one of Claims 1-9 whose total light transmittance is 70% or more. From radiant electric heaters measured according to 4.10.2 exothermic test and evaluation method in “Fireproof and Fireproof Performance Test and Evaluation Method of Operation” of the Building Materials Testing Center (modified version on March 1, 2014) In the exothermic test where the surface of the sheet is irradiated with radiant heat of 50 kW / m ² , the maximum heat generation rate after the start of heating continues for 10 seconds or more and does not exceed 200 kW / m ² , and the total calorific value is 8 MJ / m ² or less. The sheet according to any one of claims 1 to 10.   The sheet according to any one of claims 1 to 11, wherein the peel strength of the second resin layer measured according to JIS K 6854-2: 1999 is 20 N / 25 mm or more.   The sheet according to claim 1, wherein the thickness is 0.5 mm or more.