JP5703672B2 - Non-combustible sheet joint - Google Patents

Description

  The present invention relates to a joined product of non-combustible sheets.

  In recent years, large sheets have been used in applications such as outdoor sign boards and internally illuminated signboards. As a sheet for such a use, a sheet in which a plurality of sheets obtained by impregnating a glass cloth with a resin is bonded to maintain mechanical strength is used. In addition, in particular, as a sheet used for large internally illuminated signboards and outdoor signboards, nonflammability has been demanded in recent years due to safety issues, and glass cloth was impregnated with nonflammable or flame retardant resin. The use of non-flammable or flame retardant sheets has been proposed.

  In the following Patent Document 1, when joining a flame retardant sheet, a hot melt adhesive is laminated and integrated on one surface of a tape base material as a joining tape, or the hot melt adhesive itself is formed in a tape shape. Things are listed.

JP 2010-72378 A

  However, according to the study by the present inventors, when a non-combustible sheet is joined by thermal welding at a temperature (100 ° C. or higher) at which hot-melting is performed using a normal hot-melt adhesive, the non-combustible sheet is used. Depending on the resin used, the non-combustible sheet may be warped or wavy.

  Therefore, an object of the present invention is to provide a joined product of non-combustible sheets having sufficient adhesiveness while suppressing the occurrence of warpage and undulation of the non-combustible sheet during heat welding.

  The present inventors have found that by adjusting the ratio of the glass cloth and the resin layer contained in the bonding tape and the non-combustible sheet, heat welding can be performed without causing warpage of the non-combustible sheet. It came to achieve.

  That is, the present invention is a sheet joined product obtained by coating one surface of a plurality of non-combustible sheets with end surfaces butted together with a joining tape so as to cover the butted portions and heat-welding them. The sheet is provided with a glass cloth having a content of 20 to 60% by mass with respect to the total mass of the non-combustible sheet between the first resin layers each including a vinyl chloride resin having a thickness of 30 to 180 μm facing each other. Yes, the bonding tape has a thickness of 40 to 200 μm made of a resin that is the same as or different from the resin composition, one on each side of the reinforcing fiber layer impregnated with a resin composition containing a vinyl chloride resin in a glass cloth. The second resin layer is formed, and the content of the glass cloth is 10 to 40% by mass with respect to the total mass of the bonding tape.

  According to the above configuration, as a result of suppressing the occurrence of warpage and undulation of the non-combustible sheet at the time of heat welding, a variation in the adhesive strength between the non-combustible sheet and the joining tape is reduced, and a sheet joined article having sufficient adhesiveness is provided. it can. Moreover, the designability of the junction part of a nonflammable sheet can be improved by suppressing the waviness of the nonflammable sheet at the time of heat welding.

  Moreover, since the non-combustible sheet and the bonding tape include a non-combustible glass cloth and a highly non-combustible vinyl chloride resin, the sheet bonded product of the present invention increases the non-flammability of the entire sheet bonded product. be able to.

  The joining tape preferably has a difference in refractive index between the glass cloth and the second resin layer of less than 0.01, a haze of 40% or less, and a total light transmittance of 85% or more.

  In this case, the transparency of the bonding tape is remarkably increased. The internally illuminated signboard has a problem that, when illuminated with a light source from behind the joining surface of the incombustible sheet, if the joining tape and the incombustible sheet have different colors or the like, the joining tape can be visually recognized as a shadow. Therefore, when the transparent bonding tape of the present invention is used for an internally illuminated signboard or the like, the bonding tape is visually recognized as a shadow regardless of the color of the nonflammable sheet when illuminated with a light source from behind the bonding surface of the nonflammable sheet. Can be avoided. As a result, the design as an internally illuminated signboard is enhanced.

The glass constituting the glass cloth of the bonding tape is weight% with respect to the total weight of the glass, SiO ₂ is 50.0 to 60.0%, Al ₂ O ₃ is 10.0 to 20.0%, B ₂ O ₃ is 20.0 to 30%, MgO is 0.0-4.0%, CaO is _{0.0% ~6.0%, Li 2 O} + Na 2 O + K 2 O is 0.0 to 0.5%, TiO ₂ preferably has a composition of 0.5 to 5.0%.

  In this case, in addition to the effect of reducing warpage and undulation of the non-combustible sheet at the time of heat welding, the design of the entire joined sheet can be improved by improving the transparency of the joining tape.

  The melting point of the second resin layer of the joining tape is preferably 5 to 10 ° C. lower than the melting point of the first resin layer of the noncombustible sheet. In addition, melting | fusing point can be measured based on JISK7121 grade | etc.,.

  The resin of the second resin layer of the bonding tape has a melting point lower than that of the resin of the first resin layer of the non-combustible sheet, so that the resin of the second resin layer of the bonding tape is processed at the same temperature. The resin is easily impregnated with the glass cloth of the bonding tape. For this reason, by impregnating the glass cloth of the joining tape with the resin, the transparency of the joining tape such as translucency is improved, and the joining tape can be more reliably avoided from being shaded.

  ADVANTAGE OF THE INVENTION According to this invention, the joining thing of the joining tape which has sufficient adhesiveness can be provided, suppressing generation | occurrence | production of the curvature of a nonflammable sheet | seat at the time of heat welding, and a wave.

It is sectional drawing which shows one Embodiment of the joined article of a nonflammable sheet. It is sectional drawing of the sheet | seat joined article for internally illuminated signboards which provided the printing layer etc. (A) is a sheet bonded article for double-sided printing, and (b) is a sheet bonded article for single-sided printing.

  Hereinafter, with reference to drawings, the suitable embodiment of the joined thing of the noncombustible sheet concerning the present invention is described in detail.

  FIG. 1 is a cross-sectional view showing an embodiment of a joined product of non-combustible sheets 1. As shown in FIG. 1, the sheet bonded article 10 is formed by covering one surface of a plurality of non-combustible sheets 1 arranged with their end faces butted with a bonding tape 2 so as to cover the butted parts and heat-welding them. . Hereinafter, the sheet bonded article 10 will be described in detail.

  The non-combustible sheet 1 includes a warp and a weft (both are made of a glass fiber bundle, and the glass fiber bundle is composed of a plurality of glass monofilaments between the first resin layers 4 containing a vinyl chloride resin facing each other. Are provided with a glass cloth 3 woven.

  The thickness of the first resin layer 4 is preferably 30 to 180 μm, and more preferably 70 to 150 μm. Further, the thickness of the first resin layer 4 is the same as each other, or the thickness of the first resin layer 4 on the side not covered with the bonding tape 2 is 20 μm larger than the thickness of the other first resin layer 4. It is preferable that it is large within a range not exceeding. Even if it is a case where it joins with the joining tape 2 because the thickness of the 1st resin layer 4 exists in this range, distortion etc. may arise in the incombustible sheet 1 by the weight difference of both surfaces which pinched | interposed the glass cloth 3. Absent.

  20-60 mass% is preferable with respect to the total mass of the nonflammable sheet 1, and, as for content of the glass cloth 3 of the nonflammable sheet 1, 40-50 mass% is more preferable.

  In the bonding tape 2, a second resin layer made of the same or different resin as the resin composition is formed on both surfaces of the reinforcing fiber layer in which a glass cloth is impregnated with a resin composition containing a vinyl chloride resin. It is a thing. Since the non-combustible sheet 1 and the bonding tape 2 have substantially the same thermal expansion coefficient because the glass cloth is included in the bonding tape 2, even if these bonded materials are used in a high-temperature environment such as an internally illuminated signboard, etc. The occurrence of distortion at the joint is suppressed.

  The thickness of the second resin layer is preferably 40 to 200 μm, and more preferably 100 to 140 μm. Moreover, it is preferable that the thickness of the 2nd 2 resin layer formed one each on both surfaces of a reinforcement fiber layer is mutually the same.

  10-40 mass% is preferable with respect to the total mass of the joining tape 2, and, as for content of the glass cloth of the joining tape 2, 15-30 mass% is more preferable.

  When the thicknesses of the first resin layer 4 and the second resin layer, and the glass cloth content of the incombustible sheet 1 and the joining tape 2 are under the above conditions, the first resin layer 4 and the second resin layer are substantially When it consists only of a vinyl chloride-type resin, the heat welding of the nonflammable sheet | seat 1 is possible at 60-95 (especially 70-80) degreeC, and it has sufficient adhesiveness. In addition, since the nonflammable sheet 1 can be bonded in a short time, warpage or the like hardly occurs.

  In the bonding tape 2, a second resin layer made of the same or different resin as the resin composition is formed on both surfaces of the reinforcing fiber layer in which a glass cloth is impregnated with a resin composition containing a vinyl chloride resin. It is a thing. That is, it is preferable that the 2nd resin layer is formed in both surfaces of the glass cloth impregnated with the resin composition. By forming the second resin layer on both surfaces of the glass cloth impregnated with the resin composition, the surface of the bonding tape 2 becomes the second resin layer, and the surface smoothness is improved. The second resin layer does not contain glass cloth and preferably has a thickness of 40 to 200 μm, and the surface smoothness of the bonding tape 2 is further improved. When the thickness of the resin layer is less than 40 μm, the glass cloth pattern is raised and the surface smoothness of the bonding tape 2 tends to be lowered. When the thickness of the second resin layer is greater than 200 μm, the distance from the surface of the bonding tape 2 to the glass cloth increases, so that the property of the bonding tape 2 that is difficult to burn tends to decrease. The thickness of the second resin layer is more preferably 100 to 140 μm. By setting it as the said range, the surface smoothness of the joining tape 2 improves further, maintaining the property which is hard to burn.

  The material of the resin constituting the second resin layer may be the same as or different from the resin composition constituting the reinforcing fiber layer, but from the viewpoint of improving the transparency of the bonding tape 2, 2 The difference between the refractive index of the resin constituting the resin layer and the refractive index of the resin composition constituting the reinforcing fiber layer is preferably less than 0.01, and more preferably less than 0.005. Moreover, it is preferable that the resin material which comprises a 2nd resin layer is made from a soft vinyl chloride from the point of a blocking resistance, a softness | flexibility, and a weather resistance improvement. Moreover, you may add a flame retardant, a plasticizer, an antistatic agent, a ultraviolet absorber, a stabilizer, etc. to resin which comprises a 2nd resin layer.

  The refractive index can be measured according to the method of measuring the refractive index of plastic according to JIS K7142.

  The total light transmittance of the bonding tape 2 is preferably 85% or more, and more preferably 90% or more. By setting such a transmittance, light passes sufficiently, and the transparency of the bonding tape 2 is improved. The total light transmittance is a ratio of light transmitted through the bonding tape 2 out of light incident on the bonding tape 2.

  The haze of the bonding tape 2 is preferably 40% or less. By setting the haze to 40% or less, the light incident on the bonding tape 2 is not diffused and excellent transparency is obtained. The haze is more preferably 20% or less, further preferably 10% or less, particularly preferably 7% or less, and most preferably 6% or less. When the haze is smaller, the haze is eliminated and the transparency of the bonding tape 2 is further improved.

In the bonding tape 2, the mass per unit area of the resin composition comprising the resin composition constituting the reinforcing fiber layer and the resin composition constituting the second resin layer is preferably 50 to 900 / m ^2. . By setting the mass of the resin composition to 50 g / m ² or more, it is possible to prevent a phenomenon in which a glass cloth pattern appears and a phenomenon in which the resin appears whitened due to poor impregnation. Moreover, the ratio of the glass cloth in the joining tape 2 becomes high by making the mass of the resin composition 15 900 g / m ² or less, and the property that the joining tape 2 is hard to burn can be enhanced.

From the viewpoint of improving the surface smoothness of the incombustible sheet 1, the mass per unit area of the resin composition is preferably 200 to 300 g / m ² .

The mass per unit area of the glass cloth 3 in the incombustible sheet 1 is preferably 100 to 400 g / m ² . By making the mass per unit area 100 g / m ² or more, the strength of the glass cloth 3 is sufficiently increased, and even when a plurality of non-combustible sheets 1 are joined, the joined product has sufficient strength. Further, by setting the mass per unit area to 400 g / m ² or less, even when a plurality of non-combustible sheets 1 are bonded, the deflection of the sheet bonded article 10 due to the weight of the glass cloth 3 is reduced to a negligible level. . The mass per unit area of the glass cloth 3 in the incombustible sheet 1 is more preferably 200 to 350 g / m ² .

  Moreover, in order to ensure the intensity | strength of the glass cloth 3, the glass cloth 3 in the nonflammable sheet 1 has a monofilament diameter of 3 to 9 μm, a number of monofilaments of 50 to 800, and 2.8 to 135 tex (g / A glass fiber bundle of 1000 m) is preferably woven by plain weaving so that the weaving density of the warp is 20 to 70/25 mm and the weaving density of the weft is 20 to 70/25 mm. Moreover, it is more preferable to use glass fiber intertwisted yarn having a high glass content as warp and / or weft in order to improve the strength of the glass cloth 3. Furthermore, in order to improve the smoothness of the glass cloth, the glass cloth 3 in the non-combustible sheet 1 is preferably subjected to a fiber opening process.

The mass per unit area of the glass cloth in the bonding tape 2 is preferably 10 to ²⁰⁰ g / m ² . By making the mass per unit area 10 g / m ² or more, the strength of the glass cloth can be sufficiently increased. Moreover, by making the mass per unit area 200 g / m ² or less, the thickness of the glass cloth can be reduced, and the transparency can be obtained more easily. The mass per unit area of the glass cloth in the bonding tape 2 is more preferably 50 to 150 g / m ² .

In order to ensure the strength of the glass cloth, the glass cloth in the bonding tape 2 has a monofilament diameter of 3 to 9 μm, a number of monofilaments of 50 to 800, and 2.8 to 135 tex (g / 1000 m). The glass fiber bundle is preferably woven with plain weave so that the weave density of the warp is 20 to 70/25 mm and the weave density of the weft is 20 to 70/25 mm. Furthermore, in order to reduce the thickness of the glass cloth and improve the total light transmittance, the glass cloth in the bonding tape 2 is preferably subjected to a fiber opening treatment. With the fiber opening treatment, the interval between adjacent warp yarns and between adjacent weft yarns is 0.5 mm or less, preferably 0.1 mm or less, and the air permeability according to the air permeability test method of JIS L 1096 is at most 10 cm ^3. / Cm ² / s is preferable because the nonflammability of the bonding tape 2 is improved.

  The glass constituting the glass cloth 3 of the incombustible sheet 1 is not particularly limited, but E glass is preferable from the viewpoint of availability.

The glass constituting the glass cloth of the bonding tape 2 is made of glass having a basic composition of at least one of CaO and MgO and SiO ₂ . Further, the glass is CaO, may also contain MgO and SiO ₂ other components. Components other than CaO, MgO and SiO ₂ include Al ₂ O ₃ , Fe ₂ O ₃ , Na ₂ O, TiO ₂ , Li ₂ O, K ₂ O, ZrO ₂ , B ₂ O ₃ , MoO ₂ and GeO _2. , P ₂ O ₅ , P ₂ O ₃ , V ₂ O ₅ , BeO, ZnO, BaO and Cr ₂ O ₃ . However, the alkali metal oxide content in the glass is preferably 1% by mass or less. By setting the content of the alkali metal oxide to 1% by mass or less, the transparency of the bonding tape 2 can be increased.
The

Any glass may be used as long as it has the above glass composition. However, considering the production of glass, preferable glass includes, for example, C glass, T glass, NE having the composition shown in Table 1 below. Glass etc. can be illustrated.

Among these glasses, T glass and NE glass are preferably used because the transparency of the bonding tape 2 is excellent, and NE glass is more preferably used because transparency is particularly excellent. That is, the glass constituting the glass cloth of the bonding tape 2 is in weight percent with respect to the total weight of the glass, SiO ₂ is 50.0 to 60.0%, Al ₂ O ₃ is 10.0 to 20.0%, B ₂ O ₃ is 20.0 to 30.0%, MgO is .0 to 4.0%, CaO is _{0.0% ~6.0%, Li 2 O} + Na 2 O + K 2 O is from 0.0 to 0 0.5% and TiO ₂ preferably have a composition of 0.5 to 5.0%.

  The resin composition which forms the 1st resin layer 4 of the nonflammable sheet 1 and the 2nd resin layer of the joining tape 2 in this embodiment all contains a vinyl chloride resin. By using the same kind of resin material, compatibility is enhanced, and the nonflammable sheet 1 and the bonding tape 2 can be bonded in a short time while lowering the heat welding temperature. Specifically, heat welding is possible under conditions of a temperature of 60 to 95 ° C. and a time of 2 to 12 seconds.

  The vinyl chloride resin here means a resin having a molecular chain made of a copolymer containing vinyl chloride as a monomer unit in addition to polyvinyl chloride. Examples of monomers that can be copolymerized with vinyl chloride include vinylidene chloride, vinyl acetate, ethylene, propylene, acrylonitrile, maleic acid or its ester, acrylic acid or its ester, and methacrylic acid or its ester.

  In addition, the melting point of the second resin layer of the bonding tape 2 is preferably 5 to 10 ° C. lower than the melting point of the first resin layer 4 of the incombustible sheet 1. In this case, since the resin of the second resin layer of the bonding tape 2 is easier to soften than the resin of the first resin layer 4 of the non-combustible sheet 1, the treatment of the second resin layer of the bonding tape 2 is performed at the same temperature. The resin is easily impregnated with the glass cloth of the bonding tape 2. For this reason, by impregnating the glass cloth of the joining tape 2 with the resin, the transparency of the joining tape 2 such as translucency is improved, and it is possible to more reliably avoid the joining tape 2 from being shaded. In addition, melting | fusing point of the 1st resin layer 4 and the 2nd resin layer can be adjusted by changing the kind and quantity of a plasticizer mentioned later.

  The resin composition in the joining tape 2 preferably contains a plasticizer. By including a plasticizer, the flexibility of the bonding tape 2 can be improved and the generation of wrinkles can be suppressed. The plasticizer should just be compatible with the above-mentioned vinyl chloride resin. Such plasticizers include, for example, phthalates, aliphatic dibasic esters, phosphate esters, trimellitic esters, glycol esters, epoxidized esters, citrate esters, tetra- Examples thereof include n-octyl citrate, polypropylene adipate, sulfonamides, and other polyester plasticizers. Examples of the phthalic acid esters include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di-n-octyl phthalate, diisodecyl phthalate, diisononyl phthalate, butyl benzyl phthalate, and higher grades having about 11 to 13 carbon atoms. Examples include phthalate esters of alcohol. Examples of the aliphatic dibasic acid esters include dibutyl adipate, di-n-hexyl adipate, and dibutyl sebacate. Examples of the phosphate esters include tributyl phosphate, tri-2-n-ethylhexyl phosphate, tricresyl phosphate, and triphenyl phosphate. Examples of trimellitic acid esters include trimellitic acid-tri-2-ethylhexyl and trimellitic acid tributyl. Examples of glycol esters include pentaerythritol ester and diethylene glycol benzoate. Examples of epoxidized esters include epoxidized soybean oil and epoxidized linseed oil. Examples of the citrate esters include acetyl tributyl citrate, acetyl trioctyl citrate, and tri-n-butyl citrate. These plasticizers are used alone or in combination of two or more.

  The blending ratio of the plasticizer is preferably 5 to 30 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. By making this blending ratio 5 parts by weight or more, the flexibility of the bonding tape 2 tends to increase as compared with the case of less than 5 parts by weight. When the blending ratio of the plasticizer is 30 parts by weight or less, the content of the vinyl chloride resin in the resin composition is higher than that in the case where it exceeds 30 parts by weight. Tend to improve. The blending ratio of the plasticizer is more preferably 10 to 20 parts by weight. By setting the blending ratio within the above range, the flexibility of the bonding tape 2 is further increased and the property of being hard to burn is further improved. Moreover, it is not necessary to add a plasticizer to a resin composition according to the use of the joining tape 2. FIG. When the content of the glass cloth is higher than that of the bonding tape 2, the nonflammable sheet 1 includes a larger amount of plasticizer in the first resin layer 4 of the nonflammable sheet 1 than in the second resin layer of the bonding tape 2. Even if it is, the nonflammability of the nonflammable sheet 1 is ensured.

  In addition to the plasticizer, the resin composition may contain additives such as a flame retardant, an ultraviolet absorber, a filler, and an antistatic agent.

<Sheet bonded product>
As shown in FIG. 1, the sheet bonded article 10 is coated with the bonding tape 2 so as to cover the butted portions on one side of the plurality of non-combustible sheets 1 arranged with the end faces butted, and thermally bonded. Become.

  Examples of the heat welding means include high frequency welding, hot air welding, and hot plate welding, and high frequency welding is preferable because it can be welded at a relatively low temperature. As a procedure of high-frequency welding, for example, a portion in which the non-combustible sheet 1 is coated with the joining tape 2 is used, using a high-frequency welding machine (manufactured by Yamamoto Vinita Co., Ltd.), anode current 0.5 to 5A, temperature 60 to 95 ° C. It is possible to perform welding for 2 to 12 seconds under the above conditions, and it is more preferable to perform welding for 3 to 8 seconds under conditions of an anode current of 0.6 to 2 A and a temperature of 70 to 80 ° C.

  As described above, the nonflammable sheet 1 is not warped because it can be bonded by short-time heat welding. However, if the welding temperature is lower than 60 ° C., the resin is not sufficiently softened and sufficient adhesion cannot be obtained. On the other hand, if it is higher than 95 ° C., the non-combustible sheet 1 may be warped. Moreover, it is preferable that the welding temperature is 70 to 80 ° C., because welding can be performed efficiently.

  By providing the printed layer 5 containing an acrylic resin and a fluororesin on the sheet bonded article 10 thus obtained, it can be used as an outdoor lighting signboard. A cross-sectional view of the sheet joined article 10 provided with the printing layer 5 is shown in FIG. (A) is sectional drawing of the sheet | seat joined article for double-sided printing in which the printing layer 5 was provided in both surfaces, (b) is a cross section of the sheet | seat joined article for single-sided printing in which the printing layer 5 was provided only in the single side | surface. FIG. As shown to (a), as for the double-sided printing sheet joining thing, the 1st resin layer 4 is provided on both surfaces of the glass cloth 3, and the printing layer 5 is provided in the upper and lower sides of the 1st resin layer 4 further. It has been. On the other hand, as shown in (b), the single-sided printing sheet bonded product is provided with the first resin layer 4 on both surfaces of the glass cloth 3 (non-combustible sheet 1), and the non-combustible sheet 1 bonding tape 2 (not shown). ) Side is provided with a protective layer 6, and the bonding tape 2 is provided with a printed layer 5 on the opposite side.

  EXAMPLES Hereinafter, although the preferable Example of this invention is described in detail, this invention is not limited to these Examples.

(Example 1)
[Production of glass cloth]
E glass (component: SiO ₂ 55 wt%, Al ₂ O ₃ 14 wt%, CaO 23 wt%, MgO 1 wt%, R ₂ O 0.6 wt%, B ₂ O ₃ 6 wt%, TiO ₂ 0.3 wt%; R is alkali A glass fiber yarn in which two glass fiber bundles having a monofilament diameter of 6 μm, a monofilament number of 800, and 67.5 tex are used as a warp and a weft, and a weft density of 30/25 m, a weft of weft After weaving in plain weave so that the density would be 32/25 mm, thermal deoiling, surface treatment with methacryloxypropyltrimethoxysilane, and fiber opening treatment were performed to produce a glass cloth for nonflammable sheets. The resulting glass cloth had a mass per unit area of 340 g / m and a thickness of 270 μm.

Using NE glass having a glass composition shown in Table 1, a monofilament diameter of 7 μm, a monofilament number of 200, a glass fiber bundle of 22.4 tex is used as warp and weft, the warp weave density is 60 yarns / 25 m, and the weft weave density is After weaving in plain weave so as to be 58 pieces / 25 mm, thermal deoiling, surface treatment with methacryloxypropyltrimethoxysilane, and fiber opening treatment were performed to produce a glass cloth for a bonding tape. The resulting glass cloth has a mass per unit area of 100 g / m, a thickness of 85 μm, an air permeability of 6 cm ³ / cm ² / s, between adjacent warps and between adjacent wefts. The yarn spacing was 0.05 mm.

[Production of non-combustible sheet]
A soft vinyl chloride sheet (Mitsubishi Resin Co., Ltd., melting point 150 ° C.) having a thickness of 80 μm was pasted on both surfaces of the obtained glass cloth for incombustible sheet as a first resin layer, and the surface was heated by a 110 ° C. hot press. Heat-pressed and laminated to obtain a non-combustible sheet. At this time, content of the glass cloth with respect to the total mass of a nonflammable sheet | seat was 59 mass%.

[Preparation of bonding tape]
15 parts by weight of dibutyl phthalate as a plasticizer was added to 100 parts by weight of a vinyl chloride resin (manufactured by Kaneka Co., Ltd., trade name: Kanebilak) mainly composed of a copolymer of vinyl chloride and vinyl acetate, and diluted with 75 parts by weight of methyl ethyl ketone. A liquid was prepared. After impregnating this liquid into the glass cloth for the above-mentioned bonding tape, it was dried at 120 ° C., and methyl ethyl ketone was volatilized to obtain a glass cloth impregnated with the resin composition. A transparent soft vinyl chloride sheet (Mitsubishi Resin Co., Ltd., melting point: 140 ° C.) having a thickness of 120 μm is pasted on both surfaces of the glass cloth impregnated with the resin composition as a second resin layer, and the surface is heated by a 110 ° C. hot press. Were laminated by heating and pressing to obtain a joining tape. In the obtained joining tape, content of the glass cloth with respect to the total mass of the joining tape was 20 mass%.
[Preparation of sheet joint]

  Prepare a plurality of non-combustible sheets prepared as described above, and after joining each end face, heat-weld a 50 mm wide joining tape to the back so that the joining width of the two non-combustible sheets is 25 mm respectively. As shown in FIG. 1, a joined product of non-combustible sheets was obtained. The welding conditions at this time were an anode current of 0.65 A, a welding temperature of 80 ° C., and a welding time of 7 seconds.

(Example 2)
Example 1 except that the transparent soft vinyl chloride sheet used for the first resin layer in Example 1 was used for the second resin layer, and the transparent soft vinyl chloride sheet used for the second resin layer was used for the first resin layer. A sheet joined product was produced in the same manner.

(Example 3)
A sheet bonded article was prepared in the same manner as in Example 1 except that T glass having the glass composition shown in Table 1 was used as the glass constituting the glass cloth used for the bonding tape.

Example 4
A sheet joined article was produced in the same manner as in Example 1 except that E glass was used as the glass constituting the glass cloth used for the joining tape.

(Comparative Example 1)
A sheet bonded article was prepared in the same manner as in Example 1 except that a transparent soft vinyl chloride sheet having a thickness of 30 μm was used as the second resin layer instead of the transparent soft vinyl chloride sheet having a thickness of 120 μm.

(Comparative Example 2)
A sheet joined article was prepared in the same manner as in Example 1, except that a transparent soft vinyl chloride sheet having a thickness of 240 μm was used instead of the transparent soft vinyl chloride sheet having a thickness of 120 μm as the second resin layer.

(Comparative Example 3)
Glass fiber bundle with a monofilament diameter of 4.5 μm, monofilament number of 100, and 4.5 tex, using warp and weft as the joining tape, using E glass of glass composition, weaving density of the warp is 69/25 m, weft weaving A sheet joined article was prepared in the same manner as in Example 1 except that a glass cloth woven in a plain weave so as to have a density of 72 pieces / 25 mm and subjected to surface treatment and fiber opening treatment was used. The glass cloth content of the bonding tape used at this time was 8% by mass with respect to the total mass of the bonding tape. In addition, the mass per unit area of the used glass cloth was 24 g / m, and thickness was 25 micrometers.

(Comparative Example 4)
As the second resin layer, instead of the transparent soft vinyl chloride sheet having a thickness of 120 μm, a transparent soft vinyl chloride sheet having a thickness of 40 μm was used, and E glass having a glass composition was used for the bonding tape. The monofilament diameter was 9 μm and the number of monofilaments 800 and 135 tex glass fiber bundles were used as warps and wefts, and weaved in plain weave so that the warp weave density was 19 / 25m and the weft weave density was 18 / 25mm. A sheet joined article was produced in the same manner as in Example 1 except that glass cloth was used. The glass cloth content of the bonding tape used at this time was 42% by mass with respect to the total mass of the bonding tape. In addition, the mass per unit area of the used glass cloth was 200 g / m, and the thickness was 250 μm.

  Further, the transparency, refractive index, adhesive strength, warpage, undulation, nonflammability, and visibility of the joining tape of the finally obtained sheet joined article were evaluated. The obtained results are shown in Table 2 together with the conditions of the non-combustible sheet and the adhesive sheet. These characteristics were determined by the following evaluation method.

(A) Evaluation of transparency The transparency of Examples 1 to 4 was evaluated. Specifically, in accordance with JIS K 7105, the total light transmittance and diffuse transmittance of the bonding tape were measured using an integrating sphere measuring device, and haze was determined from the measured values.

(B) Measurement of refractive index The refractive index of the member used for the incombustible sheet joined body of an Example and a comparative example was measured. Specifically, according to JIS K 7142, the Abbe refractometer is used to measure the refractive index of the first resin layer of the non-combustible sheet, and the glass cloth and the second resin layer of the joining tape, and the difference between these is measured. Asked.

(C) Measurement of adhesive strength The adhesive strength of the bonding tape to the nonflammable sheet in the nonflammable sheet bonded products of Examples and Comparative Examples was evaluated. Specifically, a load of 1/10 of the breaking load of the sheet was applied and left for 24 hours under a temperature condition of 60 ° C., and whether or not the joint part peeled was visually evaluated. The case where the joint part was not peeled was marked with ◯, and the case where the joint part was peeled was marked with x.

(D) Evaluation of warpage Warpage of the non-combustible sheet bonded articles of Examples and Comparative Examples was evaluated. Specifically, the sheet bonded article is cut to produce a test piece of 10 cm × 10 cm size including the bonded portion as the center, and when this test piece is left on a flat desk, it is most from the surface of the desk. The height of the raised part from the desk surface was measured using a caliper. When this height was less than 2 mm, there was no warping (O), and when it was 2 mm or more, there was warping and the appearance was impaired (X).

(E) Evaluation of corrugation The corrugation of the non-combustible sheet joined articles of Examples and Comparative Examples was evaluated. Specifically, the joined part of the sheet joined product was visually observed, and “O” indicates that no undulation phenomenon is observed, and “X” indicates that the appearance is impaired.

(F) Evaluation of nonflammability The nonflammable sheet assemblies obtained in the examples and comparative examples were subjected to exothermic tests to evaluate their difficulty in generating heat (nonflammability). Specifically, the surface of the sheet bonded article was irradiated using a radiant electric heater, 50 kW of radiant heat was applied to the sheet bonded article, and the total calorific value of the sheet bonded article for 20 minutes after the start of heating was measured. Moreover, in 20 minutes after the start of heating, the time when the calorific value of the sheet bonded product exceeded 200 kW / m ² was measured. Further, the appearance of the sheet joined product was visually observed after the heat generation test. In accordance with the Building Standards Act, the total calorific value is 8 MJ / m ² or less in the exothermic test, the calorific value does not exceed 200 kW / m ² continuously for 10 seconds or more, and the sheet joined product after the exothermic test When there were no cracks and holes penetrating, it was assumed to have nonflammability (◯), and when these conditions were not satisfied, it was marked as x.

(G) Evaluation of visibility of bonding tape The visibility of the bonding tape in the non-combustible sheet bonded product obtained in the examples and comparative examples was evaluated. Specifically, when the sheet bonded object is illuminated with a 100 W light source installed at a point 5 cm from the surface where the bonding tape exists, the shadow of the bonding tape can be visually recognized from the side not existing from the bonding tape. The case where the shadow can be visually recognized but the appearance is not impaired is indicated by Δ, and the case where the shadow is visible and the appearance is impaired is indicated by ×.

DESCRIPTION OF SYMBOLS 1 ... Nonflammable sheet, 2 ... Joining tape, 10 ... Sheet joined thing.

Claims (3)

One side of a plurality of non-combustible sheets arranged in abutment with the end faces is covered with a joining tape so as to cover the abutting part, and is a sheet joined product formed by heat welding,
The non-combustible sheet is provided with a glass cloth having a content of 20 to 60% by mass with respect to the total mass of the non-combustible sheet between the opposing first resin layers having a thickness of 30 to 180 μm.
The bonding tape, on both sides of the reinforcing fiber layer impregnated with a tree fat composition in glass cloth, one each, the second resin layer having a thickness of 40~200μm comprising the resin composition and the same or different resin materials Is formed, and the content of the glass cloth is 10 to 40% by mass with respect to the total mass of the bonding tape,
The resin material in the first resin layer, the resin composition, and the second resin layer is a vinyl chloride resin,
A sheet joined product in which the melting point of the second resin layer is lower by 5 to 10 ° C. than the melting point of the first resin layer . The joining tape has a difference in refractive index between the glass cloth and the second resin layer of less than 0.01, a haze of 40% or less, and a total light transmittance of 85% or more. sheet over preparative conjugate according to 1. The glass constituting the glass cloth of the bonding tape is in weight percent with respect to the total weight of the glass, SiO ₂ is 50.0-60.0%, Al ₂ O ₃ is 10.0-20.0%, B ₂ O ₃ is 20.0-30.0%, MgO is 0.0-4.0%, CaO is 0.0% -6.0%, Li ₂ O + Na ₂ O + K ₂ O is 0.0-0.5. % TiO ₂ has a composition 0.5 to 5.0% sheet joined product according to claim 1 or 2.

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