JP2009241476A - Laminated sheet and method for manufacturing laminated sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated sheet capable of ensuring sufficient peeling strength even under ultra low temperature while preventing a urethane resin from bleeding from a glass fiber fabric, and a method for manufacturing the laminated sheet. <P>SOLUTION: The laminated sheet 1 is formed by laminating the urethane resin 3 on both surfaces of a metal foil 2, and laminating the glass fiber fabric 4 having a unit weight of 150-500 g/m<SP>2</SP>, and an air permeability of 20 cm<SP>3</SP>/cm<SP>2</SP>/s or less. An adhesive force of the glass fiber fabric 4, the urethane resin 3 and the metal foil 2 with each other can be improved by raising the pressure when pressurizing the respective members with each other by a pressure roller or the like without enabling the urethane resin 3 to bleed from the glass fiber fabric 4 by lowering the perforation ratio (air permeability) of the glass fiber fabric 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laminated sheet used as a heat insulating reinforcing material for a cryogenic tank and a method for producing the laminated sheet.

As a conventional laminated sheet, a pretreatment with a silane coupling agent is performed on a metal foil sheet, and an adhesive sheet made of polyurethane resin is interposed on both surfaces of the metal foil sheet, and sandwiched with a reinforcing material sheet made of glass fiber fabric, One formed by heat treatment after being pressed by a pressure roller is known (for example, Patent Document 1).
JP-A-60-176757

  Here, in the above laminated sheet, the adhesive strength between the glass fiber fabric and the polyurethane resin is not sufficient, and particularly when used as a heat insulating reinforcing material for a tank for liquefied natural gas, the laminated sheet is Since the temperature is extremely low, there is a problem that a sufficient peel strength cannot be obtained due to a difference in heat shrinkage between the members. Moreover, in order to improve the peel strength, blisters are generated even if the temperature of the heat treatment is simply increased, and it is difficult to obtain a desired peel strength.

  Moreover, in order to improve the adhesive force between the glass fiber fabric and the polyurethane resin, a method of increasing the pressure when the glass fiber fabric, the polyurethane resin, and the metal foil sheet are pressed with a pressure roller or the like can be considered. When the method is applied to the laminated sheet, the polyurethane resin oozes out from the glass fiber fabric, and the adhesive strength between the laminated sheet and other members (for example, urethane foam used as a heat insulating material for the tank) decreases. There was a problem that.

  Here, in order to ensure the adhesive force with another member when the polyurethane resin has oozed out of the glass fiber fabric, a method of laminating the release sheets and applying pressure can be considered. However, when the method is applied to the laminated sheet, a plasticizer or the like is mixed in the polyurethane resin, and the adhesive force between the metal foil sheet and the glass fiber fabric is reduced at an ultra-low temperature. It was necessary to avoid using it as much as possible.

  The present invention has been made to solve such a problem, and can prevent a urethane resin from exuding from a glass fiber fabric, and can ensure a sufficient peel strength even at an ultra-low temperature. It aims at providing a manufacturing method of a lamination sheet and a lamination sheet.

The laminated sheet according to the present invention is a laminated sheet formed by laminating a urethane resin on both surfaces of a metal foil and laminating a glass fiber fabric on the outer surface of each urethane resin, and the glass fiber fabric has a unit weight. It is 150-500 g / m < ² >, and air permeability is 20 cm < ³ > / cm < ² > / sec or less, It is characterized by the above-mentioned.

  In this laminated sheet, the glass fiber woven fabric, the urethane resin and the metal foil are pressed against each other without lowering the degree of ventilation (air permeability) of the glass fiber woven fabric without causing the urethane resin to bleed out from the glass fiber woven fabric. The pressure at the time of pressurizing by raising etc. can be raised, and the adhesive force of each member can be improved. Thereby, sufficient peeling strength can be ensured even under ultra-low temperatures while preventing the urethane resin from seeping out from the glass fiber fabric.

  In the laminated sheet according to the present invention, the glass fiber fabric is preferably woven using a glass fiber bundle to which a synthetic resin sizing agent is adhered as warps and wefts. Generally, a starch sizing agent is used as a sizing agent that adheres to a glass fiber bundle when weaving a glass fiber woven fabric. However, when the starch sizing agent is applied, an adhesive force with a urethane resin is ensured. Therefore, it is necessary to perform a deoiling process by heating, and there is a problem that the tensile strength of the glass fiber fabric is reduced due to the thermal deterioration due to the deoiling process. However, as in the present invention, by using a synthetic resin sizing agent as a sizing agent to be attached to the glass fiber bundle, the adhesive force between the glass fiber fabric and the urethane resin is ensured without performing a deoiling treatment by heating. This can prevent a decrease in the tensile strength of the glass fiber fabric.

  In the laminated sheet according to the present invention, the glass fiber bundle of at least one of the warp and the weft of the glass fiber fabric is preferably a glass fiber twisted yarn. If it does in this way, the tensile strength of a glass fiber fabric can be improved by using a glass fiber interwoven yarn with high glass content as a warp and / or a weft. Further, by using a glass fiber intertwisted yarn that is less prone to fuzzing than a normal glass fiber bundle, it is not necessary to use a secondary sizing agent for preventing fuzzing. A decrease in adhesive strength with the urethane resin can be prevented, and the peel strength of the laminated sheet can be improved.

  Specifically, it is preferable that 0.4% by weight or less of a synthetic resin sizing agent is attached to the glass fiber fabric.

In the method for producing a laminated sheet according to the present invention, urethane resin is laminated on both surfaces of a metal foil, and the unit weight is 150 to 500 g / m ² and the air permeability is 20 cm ³ / cm ^{2 on} the outer surface of each urethane resin. A sheet forming step of laminating a glass fiber fabric of / sec or less and pressurizing the laminate with a pressing surface having a surface temperature of 100 ° C. or less to form a sheet, and an after curing step of heating the sheeted laminate It is characterized by that.

  In this manufacturing method, the glass fiber fabric, the urethane resin, and the metal foil were laminated without causing the urethane resin to bleed out from the glass fiber fabric by lowering the degree of opening (air permeability) of the glass fiber fabric. The pressure at the time of pressurizing the laminate with a pressure roller or the like can be increased to improve the adhesive force between the members. Moreover, the urethane resin can be further prevented from oozing out by pressing the laminate with a pressing surface having a surface temperature of 100 ° C. or less. As described above, sufficient peeling strength can be ensured even at an ultra-low temperature while preventing the urethane resin from seeping out from the glass fiber fabric.

  In the laminated sheet according to the present invention, in the after-curing step, it is preferable to heat the sheeted laminate in an atmosphere of 60 to 120 ° C. If it does in this way, generation | occurrence | production of the wrinkles by the difference in the thermal expansion coefficient of metal foil, a urethane resin, and a glass fiber fabric can be prevented by making the temperature in an after-cure process into the low temperature of 60-120 degreeC.

  ADVANTAGE OF THE INVENTION According to this invention, providing the manufacturing method of the lamination sheet which can ensure sufficient peeling strength, even if it is under ultra-low temperature, preventing the seepage of the urethane resin from a glass fiber fabric. it can.

  Hereinafter, preferred embodiments of a laminated sheet and a method for producing the same according to the present invention will be described in detail with reference to the drawings.

[Laminated sheet]
FIG. 1 shows an enlarged view of a laminated sheet partially cut out. As shown in FIG. 1, the laminated sheet 1 is formed by laminating a urethane resin 3 on both surfaces of a metal foil 2 and laminating a glass fiber fabric 4 on the outer surface of each urethane resin 3. The laminated sheet 1 formed in this way is used as a heat insulation reinforcing material for an ultra-low temperature tank, and is attached to a stainless steel tank wall surface 6 via foamed urethane 5 as a heat insulation material. The laminated sheet 1 is bonded to the urethane foam 5 with an adhesive. Hereinafter, each component of the lamination sheet 1 is demonstrated in detail.

(A) Metal foil The metal foil 2 is a thin film that serves as an intermediate layer of the laminated sheet 1. As the material thereof, for example, aluminum, stainless steel, copper, amber alloy or the like can be used, and aluminum is particularly suitable. is there. Moreover, since there exists a problem of the intensity | strength with respect to an impact when the thickness is too thin, and there exists a problem that a softness | flexibility is impaired when too thick, it is suitable to set it as 50-250 micrometers, and shall be 60-100 micrometers. More preferably.

A resin composition containing a phenoxy resin and a silane compound is attached to both surfaces of the metal foil 2, and this can remarkably improve the adhesive strength with the urethane resin 3, which is sufficient even at ultra-low temperatures. High peel strength can be ensured. The phenoxy resin is produced from bisphenol and epichlorohydrin and has a molecular weight of 10,000 or more and preferably 100,000 or less. As the silane compound, known compounds can be used. For example, glycidoxypropyltrimethoxysilane and aminopropyltrimethoxysilane are particularly preferable. The mass ratio of the phenoxy resin to the silane compound (phenoxy resin mass / silane compound mass) in the resin composition is preferably 1/2 to 2/1. Also. The adhesion amount of the resin composition to the metal foil is preferably 0.5 to 15.0 g / m ² .

(B) Urethane resin The urethane resin 3 forms a resin layer that is firmly bonded to both surfaces of the metal foil 2 by the resin composition containing the phenoxy resin and the silane compound. As the material, a known molten thermoplastic urethane can be used, and it is particularly preferable to use a polyester urethane or a polyether urethane. The melting temperature of these materials is 160-230 ° C. Moreover, it is preferable that the quantity of the urethane resin 3 in the laminated sheet 1 shall be 50-400 g / m < ² >.

(C) Glass fiber fabric The glass fiber fabric 4 is a fabric woven using a glass fiber bundle composed of a plurality of glass fibers as warps and wefts. The weave structure is not particularly limited, but a plain weave is particularly preferable. Unit mass of glass fiber fabric 4 is preferably set to 150~500g / ^{m 2,} and particularly preferably to 300 to 400 g / ^{m 2.} The yarn count is 40 to 300 tex, and the density is 20 to 40 pieces / 25 mm.

It is preferable that the air permeability (degree of cross-cutting) of the glass fiber fabric 4 be as low as possible, specifically 20 cm ³ / cm ² / sec or less. In this way, by reducing the air permeability of the glass fiber fabric 4, the glass fiber fabric 4, the urethane resin 3, and the metal foil 2 are bonded together with a pressure roller without causing the urethane resin 3 to ooze out from the glass fiber fabric 4. The pressure at the time of pressurization can be raised and the adhesive force of each member can be improved. Thereby, it is possible to ensure sufficient peel strength even at an ultra-low temperature while preventing the urethane resin 3 from seeping out from the glass fiber fabric 4. Examples of the method for lowering the air permeability include a method of increasing the number of driven fibers during weaving, a method of weaving with a glass fiber bundle having a small number of twists, and a method of performing a fiber opening process after weaving.

  Examples of the fiber opening treatment method include fiber opening treatment using high-pressure jet water, fiber opening treatment using jet water using a vibro washer, and fiber opening treatment using ultrasonic vibration in water. When such fiber opening treatment is performed, the air permeability of the glass fiber fabric 4 is lowered, and at the same time, the sizing agent adhering to the glass fiber is washed away, and the amount of the sizing agent attached can be reduced. And the urethane resin 3 can be secured. Therefore, in the present invention, it is preferable to perform an opening process to lower the air permeability. The air permeability of the glass fiber fabric 4 can be measured by “JIS R3420 Glass Fiber General Test Method 7.14 Cross Breathability”.

  The glass fiber fabric 4 is woven using glass fiber intertwisted yarn as warps and wefts. FIG. 2 is an enlarged view of a glass fiber twisted yarn, and as shown in FIG. 2, a glass fiber twisted yarn 21 with less fuzz and a high glass content can be formed by twisting the glass fiber bundles 22 together. .

  When weaving the glass fiber fabric 4, the tensile strength of the glass fiber fabric can be improved by using glass fiber twisted yarn having a high glass content for warp and weft. Further, by using a glass fiber intertwisted yarn that is less prone to fuzzing than a normal glass fiber bundle, it becomes unnecessary to use a secondary sizing agent for preventing fuzzing during weaving. A decrease in the adhesive strength between the fiber fabric and the urethane resin can be suppressed, and the peel strength of the laminated sheet can be improved. In addition, although a glass fiber twisted yarn may be used for only one of the warp and the weft, it is preferable that at least the warp is a glass fiber twisted yarn. Furthermore, it is more preferable that both warp and weft are double twisted yarns.

  A primary sizing agent is attached to the warp and weft of the glass fiber fabric 4 during spinning. In addition, when a glass fiber intertwisted yarn is not used, a secondary sizing agent is attached during aging. The sizing agent is preferably a synthetic resin sizing agent rather than a starch sizing agent.

  Here, when the starch-based sizing agent is applied, in order to secure the adhesive force between the glass fiber fabric 4 and the urethane resin 3, it is necessary to perform a deoiling process by heating after weaving, and the glass fiber is thermally deteriorated. Therefore, there is a problem that the tensile strength of the glass fiber fabric 4 is lowered. On the other hand, when a synthetic resin-based sizing agent is used as the sizing agent, the adhesive force between the glass fiber fabric 4 and the urethane resin 3 can be secured without performing a deoiling treatment by heating. A decrease in the tensile strength of the fabric 4 can be prevented.

  For example, a water-soluble epoxy resin, an acrylic resin, a vinyl acetate resin, or a urethane resin is preferably used as the synthetic resin as a film forming agent for the sizing agent. The sizing agent preferably contains a silane compound. As the silane compound, for example, glycidoxypropyltrimethoxysilane and aminopropyltrimethoxysilane are suitable. The synthetic resin-based sizing agent is 0.05 to 3.0% by weight based on the glass fiber weight, but 0.4% by weight or less in order to suppress a decrease in peel strength between the glass fiber fabric 4 and the urethane resin 3. More preferably. Furthermore, it is preferable that the adhesion amount of a sizing agent is 0.2 mass% or less with respect to the glass fiber weight. An adhesion amount of 0.2% by weight or less can be achieved by performing the above-described fiber opening treatment.

[Production method of laminated sheet]
Next, with reference to FIG. 3, the manufacturing method for manufacturing the above-mentioned lamination sheet 1 is demonstrated. FIG. 3 schematically shows a manufacturing apparatus 10 for manufacturing the laminated sheet 1 described above.

  The manufacturing apparatus 10 includes a film supply unit 11 that supplies the thin film to the pressure roller 14 by rotating a film roll of a predetermined thin film, and a thin film urethane resin 3 that is disposed in the film supply unit 11. And a fabric supply unit 12 that is disposed in the molding machine 13 and that supplies the glass fiber fabric 4 to the pressure roller 14 by rotating the fabric roll of the glass fiber fabric 4. The pressure roller 14 pressurizes the predetermined thin film film, the urethane resin 3 and the glass fiber fabric 4, and the collection unit 16 that winds and collects the laminate pressed by the pressure roller 14. The

  First, a resin composition containing a phenoxy resin and a silane compound is attached to both surfaces of the strip-shaped metal foil 2 in advance (resin composition attaching step), dried at a predetermined temperature, and wound up to the film supply unit 11. Deploy. Note that the resin composition may be adhered to the metal foil 2 until the metal foil 2 is supplied from the film supply unit 11 to the pressure roller 14.

  Next, the metal foil 2, the urethane resin 3, and the glass fiber fabric 4 are supplied from the film supply unit 11, the molding machine 13, and the fabric supply unit 12 toward the pressure roller 14, respectively. In addition, in the molding machine 13, since the urethane resin 3 is heated to a high temperature of about 160 to 230 ° C., the thin-film urethane resin 3 supplied from the molding machine 13 is also a high temperature.

  Next, the metal foil 2, the urethane resin 3, and the glass fiber fabric 4 are pressed with the pressure roller 14. At this time, in order to prevent the urethane resin 3 from seeping out from the glass fiber fabric 4, it is more preferable to control the surface temperature of the pressure surface of the pressure roller 14 to 100 ° C. or less. Furthermore, it is more preferable to control the pressure surface to 60 ° C. or lower. By suppressing the seepage of the urethane resin, not only the resin adhesion to the pressure roller surface can be prevented, but also the pressure in the sheeting process can be increased, and the peel strength of the laminated sheet can be improved.

  The laminate pressed by the pressure roller 14 is taken up by the collecting unit 16 and collected in a roll shape. At this time, it is preferable to cool the laminate by a predetermined cooling means (not shown) at the stage before collection.

  The collected laminate roll is placed in the film supply unit 11, and the urethane resin 3 and the glass fiber fabric 4 are further laminated on the surface of the laminate on the metal foil 2 side, and the laminate is pressed by the pressure roller 14. The sheet is formed (sheet forming step) and recovered by the recovery unit 16 after cooling.

  The collection roll of the sheeted laminate is put in a furnace and heated in an atmosphere of 60 to 120 ° C. for 12 to 120 hours (after cure process). Thus, the generation | occurrence | production of the wrinkles by the difference in the thermal expansion coefficient of the metal foil 2, the urethane resin 3, and the glass fiber fabric 4 can be prevented by making the temperature in an after-cure process into the low temperature of 60-120 degreeC. After the after-curing process is completed, the laminated sheet manufacturing process is completed by taking out the furnace and cooling.

  In addition, the laminated sheet 1 is manufactured by adding a film supply unit and a molding machine to the above-described manufacturing apparatus, and pressing the metal foil 2, the pair of urethane resins 3, and the pair of glass fiber fabrics 4 at a time. Also good.

(Create a laminated sheet)
[Example 1]
(1) Metal foil 10 parts by mass of polybisphenol A-hydroxypropyl ether (Phenototo YP-50S, weight average molecular weight 50000-70000, manufactured by Tohto Kasei Co., Ltd.) synthesized from bisphenol A and epichlorohydrin as a phenoxy resin, γ-glycid A resin composition in which phenoxy resin and γ-glycidoxypropyltrimethoxysilane were mixed by stirring 10 parts by mass of xylpropyltrimethoxysilane, 60 parts by mass of methyl ethyl ketone, and 20 parts by mass of 2-methoxyethanol with a Henschel mixer. Then, a 1N-30 soft aluminum foil having a thickness of 70 μm and a width of 1070 mm was dipped on this resin composition and dried at 150 ° C. to obtain a metal foil to which the resin composition adhered to 5.0 g / m ² .

(2) Glass fiber fabric As a glass fiber bundle of warp and weft of glass fiber fabric, glass with 0.3 part by weight of water-soluble epoxy resin-based primary sizing agent attached to 100 parts by weight of glass fiber Using fiber twisted yarn (ECG75 1/2 3.3S), weaving into a plain weave structure of 29 warps / 25mm and 32 wefts / 25mm weft, subjected to fiber opening treatment with a vibratory washer, and a glass fiber fabric (mass 345 g / mass) m ² , thickness 0.25 mm). In addition, the adhesion amount of the primary sizing agent with respect to the glass fiber weight was 0.3% by weight before the opening process, and 0.1% by weight after the opening process. Further, the air permeability of the glass fiber fabric was 40 cm ³ / cm ² / sec before the opening treatment, and 15 cm ³ / cm ² / sec after the opening treatment.

(3) Urethane resin The pellets of polyether urethane resin (ET880 manufactured by BASF Japan Ltd.) were put into an extruder machine (molding machine) and supplied in a melted state at about 200 ° C. from the outlet of the T-die nozzle.

(4) Production of laminated sheet While supplying the above-mentioned metal foil and glass fiber fabric continuously, the above-mentioned urethane resin is supplied between them, pressurized with a pressure roller, and then cooled and hardened, so that one side of the metal foil A laminate in which a urethane resin and a glass fiber fabric were laminated only on the surface was obtained. Next, a urethane resin and a glass fiber fabric were laminated on the other surface of the metal foil in the same manner as described above. At this time, the temperature was controlled so that the surface of the pressure roller was kept at 30 to 40 ° C. The laminate thus obtained was after-cured for 48 hours in a 115 ° C. atmosphere, and then allowed to stand at room temperature to obtain a laminated sheet A1.

[Example 2]
Glass fiber single yarn (ECG37 1/0 1) in which 0.3 part by weight of water-soluble epoxy resin-based primary sizing agent is attached to 100 parts by weight of glass fiber as a glass fiber bundle of weft yarn of glass fiber fabric 0.0Z) as a glass fiber bundle of warp yarns, a glass fiber monofilament subjected to the primary sizing agent, and a water-soluble epoxy resin-based secondary sizing agent to 100 parts by weight of the glass fiber. A glass fiber single yarn subjected to a treatment for attaching 0 part by weight was used. Other than that was carried out according to the production of the laminated sheet A1 of Example 1 to obtain a laminated sheet A2. The air permeability of the glass fiber fabric before the fiber opening treatment was 30 cm ³ / cm ² / sec, and after the fiber opening treatment, it was 10 cm ³ / cm ² / sec. Moreover, the adhesion amount of the sizing agent after the fiber opening treatment was 0.15% by weight with respect to the glass fiber weight.

[Comparative Example 1]
A laminated sheet B1 of Comparative Example 1 was obtained in the same manner as in Example 1 except that a glass fiber fabric not subjected to the fiber opening treatment was used.

[Comparative Example 2]
In the production of the laminated sheet, the surface of the pressure roller was not particularly temperature-controlled, and the laminated sheet was produced by pressing. At this time, the surface temperature of the pressure roller was 110 to 130 ° C. Otherwise, a laminated sheet B2 was obtained according to the production of the laminated sheet A1 of Example 1.

[Comparative Example 3]
Except that the phenoxy resin was not contained in the resin composition and after-curing was performed in an atmosphere at 160 ° C. for 5 minutes, it was carried out according to the production of the laminated sheet A1, and a laminated sheet B3 was obtained.

(Evaluation of laminated sheet)
Appearance evaluation, tensile strength evaluation, and peel strength evaluation were performed on the laminated sheets of Example 1 and Example 2 and Comparative Examples 1 to 3, respectively.

[Appearance evaluation]
In the laminated sheet 100 m, a swollen portion having a diameter of 10 mm or more between the metal foil and the glass fiber fabric was counted as a poorly peeled portion, and the surface state was observed.

  In Comparative Example 3, there were about 100 swollen portions, but in Examples 1 and 2 and Comparative Examples 1 and 2, it was not recognized at all. Thus, it was confirmed that the occurrence of wrinkles of the laminated sheet can be prevented if the after-curing is performed at a low temperature. In Examples 1 and 2, exudation of the urethane resin was not recognized from the gap between the fiber bundles of the glass fiber fabric, but in Comparative Examples 1 and 2, exudation of the urethane resin was observed. However, the degree of seepage was worse than in Comparative Example 1.

[Tensile strength]
Each laminated sheet is cut into 5 pieces each having a width of 50 mm and a length of 400 mm in the longitudinal direction and the transverse direction, an adhesive is applied to both ends of each test piece in the longitudinal direction, and a plywood is pasted, and the room temperature is maintained. A tensile test was performed at 5 mm / min with a tensile tester under a low temperature atmosphere (-196 ° C.) and at 23 ° C. The average value of the results obtained for each of the 5 pieces is shown in Table 1.

[Peel strength]
Each laminated sheet was cut into 5 pieces each having a width of 25 mm and a length of 300 mm in the vertical direction and the horizontal direction, and an adhesive was applied to the entire surface of each test piece, and an iron jig was attached thereto, and was placed in a normal temperature atmosphere (23 ° C ) And in a low temperature atmosphere (−196 ° C.), and after 6 weeks of immersion in seawater, a peeling test was conducted at 100 mm / min with a tensile tester in accordance with ISO4578 under a normal temperature atmosphere in a wet state. The average value of the results obtained for each of the 5 pieces is shown in Table 2.

  As can be seen from Tables 1 and 2, the tensile strength greatly affected by the adhesion between the glass fiber fabric and the urethane resin is not significantly different between Examples 1 and 2 and Comparative Examples 1 to 3. However, the peel strength, which is greatly influenced by the adhesion between the urethane resin and the metal foil, differs greatly between Examples 1 and 2 and Comparative Examples 1 to 3, and in each comparative example, the decrease in the low temperature atmosphere and after immersion in seawater is also significant. I understand. In particular, since the peel strength of Comparative Example 1 is lower than that of Examples 1 and 2, it was confirmed that sufficient peel strength can be secured by lowering the air permeability of the glass fiber fabric. Moreover, since the peel strength of Comparative Example 2 was lower than that of Examples 1 and 2, it was confirmed that sufficient peel strength could be secured by controlling the surface temperature of the pressure roller.

It is the enlarged view which cut out one part of the lamination sheet which concerns on embodiment of this invention. It is an enlarged view of a glass fiber intertwisted yarn. It is the schematic of the manufacturing apparatus for manufacturing the lamination sheet shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Laminated sheet, 2 ... Metal foil, 3 ... Urethane resin, 4 ... Glass fiber fabric, 21 glass fiber twisted yarn, 22 ... Glass fiber bundle.

Claims (6)

A laminated sheet formed by laminating a urethane resin on both sides of a metal foil and laminating a glass fiber fabric on the outer surface of each urethane resin,
The glass fiber fabric has a unit weight of 150 to 500 g / m ² and an air permeability of 20 cm ³ / cm ² / sec or less.   The laminated sheet according to claim 1, wherein the glass fiber fabric is woven using a glass fiber bundle to which a synthetic resin sizing agent is attached as warps and wefts.   The laminated sheet according to claim 1 or 2, wherein the glass fiber bundle of at least one of the warp and the weft of the glass fiber fabric is a glass fiber intertwisted yarn.   The laminated sheet according to claim 1, wherein 0.4% by weight or less of a synthetic resin sizing agent is attached to the glass fiber fabric. A urethane resin is laminated on both surfaces of the metal foil, and a glass fiber fabric having a unit weight of 150 to 500 g / m ² and an air permeability of 20 cm ³ / cm ² / sec or less is laminated on the outer surface of each urethane resin. A sheet forming step of pressing the laminate with a pressing surface having a surface temperature of 100 ° C. or less to form a sheet;
An after-curing step of heating the laminate formed into a sheet;
A method for producing a laminated sheet, comprising:   The method for producing a laminated sheet according to claim 5, wherein, in the after-curing step, the sheet-formed laminate is heated in an atmosphere of 60 to 120 ° C.

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