Glass resin laminate and method for producing glass resin laminate

Abstract

The present invention relates to a glass resin laminate which has at least two glass plates, a silicone resin layer which is disposed between the two glass plates and joins the main surfaces of the two glass plates, and a metal layer which is held by the silicone resin layer, wherein the metal layer has a mesh shape.

Description

Glass resin laminate and method for manufacturing glass resin laminate

[0001] The present disclosure relates to a glass resin laminate and a method for manufacturing the same. This application claims priority to Japanese Patent Application No. 2024-055381, filed on March 29, 2024, the contents of which are incorporated herein by reference.

[0002] 2. Description of the Related Art Conventionally, there has been a door for a microwave oven in which a perforated metal plate having a large number of holes is sandwiched between two sheets of transparent glass (see, for example, Patent Document 1).

[0003] Japanese Utility Model Publication No. 60-27842

[0004] Conventional microwave oven doors can block microwaves when used as microwave oven doors, but it is difficult to see inside the oven through the perforated metal plate.

[0005] Furthermore, in devices that use microwaves other than microwave ovens or devices that use electromagnetic waves other than microwaves, or in the vicinity of such devices, when electromagnetic waves including microwaves are blocked by a transparent shielding plate having a punched metal plate, it is difficult to see the other side through the shielding plate.

[0006] Therefore, an object of the present invention is to provide a glass resin laminate having a metal layer capable of blocking electromagnetic waves from a device that uses electromagnetic waves, and allowing easy viewing of the opposite side through the metal layer, and a method for manufacturing the glass resin laminate.

[0007] A glass resin laminate according to an embodiment of the present disclosure includes at least two glass plates, a silicone resin layer disposed between the two glass plates and bonding the main surfaces of the two glass plates together, and a metal layer held by the silicone resin layer, the metal layer having a mesh shape. The present disclosure also includes the following aspects. [1] A glass resin laminate includes at least two glass plates, a silicone resin layer disposed between the two glass plates and bonding the main surfaces of the two glass plates together, and a metal layer held by the silicone resin layer, the metal layer having a mesh shape. [2] The glass resin laminate according to [1], wherein the metal layer has a black coating film on its surface. [3] The glass resin laminate according to [2], wherein the black coating film is a film coated with PTFE paint. [4] The glass resin laminate according to any one of [1] to [3], wherein the metal layer has a blackening treatment performed by oxidation, painting, or plating on its surface. [5] The glass resin laminate according to any one of [1] to [4], wherein the metal layer has a reflectance of 15% or less. [6] The glass resin laminate according to any one of [1] to [5], wherein the metal layer has a void ratio of 60% or more and 80% or less. [7] The glass resin laminate according to any one of [1] to [6], wherein the silicone resin layer is a frame-shaped silicone resin layer that joins the outer edges of the two glass plates together. [8] The glass resin laminate according to any one of [1] to [7], wherein the glass resin laminate is used for an opening and closing door of a microwave heating device. [9] A method for manufacturing a glass resin laminate, comprising: preparing two glass plates; disposing a metal layer on a main surface of one of the two glass plates; applying a silicone resin to the metal layer; bonding the other of the two glass plates and the one of the two glass plates together with the silicone resin and the metal layer sandwiched between them; and curing the silicone resin to form a silicone resin layer that is disposed between the two glass plates and bonds the main surfaces of the two glass plates together, wherein the metal layer has a mesh shape.

[0008] It is possible to provide a glass resin laminate having a metal layer capable of blocking electromagnetic waves from a device that uses electromagnetic waves, and allowing easy viewing of the opposite side through the metal layer, and a method for manufacturing the glass resin laminate.

[0009] 3 is a diagram showing an example of a microwave oven equipped with a glass resin laminate of an embodiment; FIG. 4 is a diagram showing an example of a cross-sectional structure of an opening / closing door including a glass resin laminate of an embodiment; FIG. 5 is a perspective view showing an example of a configuration of a glass resin laminate of an embodiment; FIG. 6 is a diagram showing an example of a cross-section taken along the arrows B-B in FIG. 3; FIG. 7 is a diagram showing an example of a metal layer; FIG. 8 is a diagram showing actual measurements of the wire diameter, mesh density, inter-wire distance, aperture ratio, and visible light transmittance of a mesh metal layer in a plurality of samples of a glass resin laminate of an embodiment; FIG. 9 is a schematic diagram showing an example of steps in an embodiment of a method for manufacturing a glass resin laminate; FIG. 10 is a schematic diagram showing an example of steps in an embodiment of a method for manufacturing a glass resin laminate; FIG. 11 is a schematic diagram showing an example of steps in an embodiment of a method for manufacturing a glass resin laminate;

[0010] Hereinafter, embodiments of the glass resin laminate and the method for manufacturing the glass resin laminate according to the present disclosure will be described. In the following, the same elements will be denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0011] In the following description, an XYZ coordinate system is defined. The direction parallel to the X axis (X direction), the direction parallel to the Y axis (Y direction), and the direction parallel to the Z axis (Z direction) are perpendicular to one another. In the following, a plan view refers to a view from the XY plane, and a front view refers to a view from the XZ plane. In the following description, the length, width, thickness, etc. of each part may be exaggerated to make the configuration easier to understand. Terms such as parallel, right angle, orthogonal, horizontal, vertical, and up and down are permitted to deviate to the extent that they do not impair the effects of the embodiments.

[0012] 1 is a diagram showing an example of a microwave oven 100 equipped with a glass resin laminate 10 according to an embodiment. In the following, an example will be described in which the Z direction is the vertical direction and the XY plane is the horizontal plane.

[0013] The glass resin laminate 10 is a part of the door 110 of the microwave oven 100 and has transparent glass to allow the interior of the microwave oven to be seen from the outside. The outside refers to the outside of the microwave oven 100, and the interior refers to the internal space that is closed by the door 110 of the microwave oven 100 and in which food and the like can be heated. "Transparent" refers to transparency to visible light, and "transparent" to visible light means that the visible light transmittance calculated by measuring the transmittance with a spectrophotometer using a D65 light source in accordance with ISO-9050:2003 is at least 40%, preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more. The relationship between the glass resin laminate 10 and the door 110 will be described in detail below using FIG. 2.

[0014] Here, a form in which the glass resin laminate 10 is mounted in a microwave oven 100 that includes a microwave generator and is capable of heating food and the like will be described, but the glass resin laminate 10 may also be part of the door of an electronic oven range that adds an oven function to the microwave oven 100. The microwave oven 100 and the electronic oven range are forms of electric microwave heating equipment. In these applications, the glass resin laminate 10 only needs to have the heat resistance required for the microwave oven 100 or the door 110 of the electronic oven range. Note that, when used as the door 110 of the electronic oven range, higher heat resistance is required of the glass resin laminate 10 compared to when used as the door 110 of the microwave oven 100.

[0015] The glass resin laminate 10 may be provided in a microwave-shielding portion of an electric microwave heating device other than the microwave oven 100 and the electronic oven range. One example of such an electric microwave heating device is an industrial electric microwave heating device.

[0016] Furthermore, the glass resin laminate 10 can be used to protect communication devices, communication facilities, sensors, and the like from electromagnetic waves, not limited to microwaves. The glass resin laminate 10 may also be used to suppress leakage of electromagnetic waves from production facilities that generate strong electromagnetic waves. Conversely, the glass resin laminate 10 may also be used to protect facilities that are vulnerable to electromagnetic waves from electromagnetic waves. In these applications, if heat resistance is not required to a great extent, the glass resin laminate 10 may have a configuration that does not take heat resistance into consideration.

[0017] The glass resin laminate 10 can also be used as a glass window or partition in a room where an MRI (Magnetic Resonance Imaging) device is installed, a glass window in a room where an electric furnace is installed, or a window that requires microwave shielding, such as an observation window provided in an electric furnace for visually observing the inside of the electric furnace. In the case of these applications, the glass resin laminate 10 may have a configuration that does not take heat resistance into consideration as much if heat resistance is not required to a great extent.

[0018] 2 is a diagram showing an example of a cross-sectional structure of an opening / closing door 110 including the glass resin laminate 10. Fig. 2 shows a cross section of the opening / closing door 110 corresponding to the cross section seen from the arrow AA in Fig. 1.

[0019] <Openable / Closed Door 110> Openable / Closed Door 110 is attached to the housing of microwave oven 100 so as to be able to open and close freely. Openable / Closed Door 110 includes a metal frame 111, outer glass 112, and glass resin laminate 10. As an example, metal frame 111 is a metal member that is rectangular and frame-shaped when viewed from the front (XZ plane), and is part of the frame of openable / closed door 110. The rectangular and frame-shaped means that it is rectangular and annular.

[0020] The metal frame 111 has an opening in the center when viewed from the front, which corresponds to the outer glass 112 and the glass resin laminate 10. The metal frame 111 is electrically connected to the ground (reference potential point). The metal frame 111 may be covered with a resin cover or the like, or may be decorated with paint, film, or the like.

[0021] <Outer Glass 112> The outer glass 112 is a glass piece arranged on the outermost side (negative Y direction side) of the opening / closing door 110, and is fixed to the metal frame 111. The outer glass piece 112 is a glass plate that is transparent to visible light. As the outer glass piece 112, for example, a tempered glass plate or an untempered glass plate can be used. As the tempered glass plate, for example, soda lime glass is used. As the untempered glass plate, for example, soda lime glass is used. Note that there may be two or more outer glasses 112. That is, there may be multiple outer glasses 112. When there are multiple outer glasses 112, the multiple outer glasses 112 may be arranged with a gap between them.

[0022] <Glass resin laminate 10> The glass resin laminate 10 includes a laminated glass 11 and a mesh metal layer 18. The following description will be made with reference to Figs. 3 and 4 in addition to Figs. 1 and 2. Fig. 3 is a perspective view showing an example of the configuration of the glass resin laminate 10 of an embodiment. Fig. 4 is a view showing an example of a cross section taken along the line B-B in Fig. 3.

[0023] <Laminated Glass 11> The laminated glass 11 includes two glass plates 12, 14 and a silicone resin layer 16 disposed between the two glass plates 12, 14 and bonding the main surfaces of the two glass plates 12, 14 together.

[0024] Hereinafter, when a numerical range is expressed using "to", the upper and lower limit values ​​indicated by "to" are included in the numerical range.

[0025] <Glass Plates 12, 14> The glass plates 12, 14 have two opposing main surfaces and an end surface connecting the two main surfaces. The glass plates 12, 14 are arranged in positions where their respective main surfaces face each other.

[0026] Each of the glass plates 12, 14 preferably has a thickness of 0.1 mm to 10 mm, more preferably 1 mm to 10 mm, and even more preferably 1 mm to 5 mm. If the thickness of the glass plates 12, 14 is 0.1 mm or more, the glass plates 12, 14 are less likely to break and are easier to handle. Furthermore, if the thickness of the glass plates 12, 14 is 10 mm or less, the weight of the glass resin laminate 10 can be reduced, making it easier to open and close the opening / closing door 110. Furthermore, the configuration of parts such as hinges that support the opening / closing door 110 can be simplified, thereby reducing costs.

[0027] The total thickness of the glass plates 12 and 14 is preferably 0.5 mm to 20 mm, more preferably 2 mm to 15 mm, and even more preferably 3 mm to 10 mm. If the total thickness of the glass plates 12 and 14 is 0.5 mm or more, the glass plates are less likely to break and are easier to handle. Furthermore, if the total thickness of the glass plates 12 and 14 is 20 mm or less, the weight of the glass resin laminate 10 can be reduced, making it easier to open and close the door 110. Furthermore, the configuration of parts such as hinges that support the door 110 can be simplified, thereby reducing costs.

[0028] The thickness of each of the glass plates 12, 14 and the total thickness of the glass plates 12, 14 are not limited to the above ranges. The thicknesses of the glass plates 12, 14 may be different.

[0029] The thermal shrinkage of the glass plates 12 and 14 is preferably small. The linear expansion coefficient at 50°C to 350°C, which is an index of the thermal shrinkage, is 100 x 10 －７ / °C or less, and －７ / °C or less, and more preferably 50 x 10 －７ / °C or less. The glass plates 12, 14 having a linear expansion coefficient within the above range can suppress the occurrence of warping, breakage, etc., even when the temperature of the glass resin laminate 10 rises. The linear expansion coefficient is measured in accordance with JIS R3102 (1995) using a differential thermal dilatometer. There is no particular restriction on the lower limit of the linear expansion coefficient at 50°C to 350°C, but it is preferred that it is 30 x 10 －７ / °C or more. The linear expansion coefficient at 50°C to 350°C is 30 x 10 －７ ~100 x 10 －７ / °C is preferred, and 30 x 10 －７ ~80 x 10 －７ / °C is more preferable, and 30 × 10 －７ ~50 x 10 －７ / °C is more preferred.

[0030] The glass plates 12, 14 may be manufactured by the float process or the fusion process. The composition of the glass plates 12, 14 is not particularly limited. The glass plates 12, 14 are preferably made of soda-lime glass, alkali-free borosilicate glass, borosilicate glass, high-silica glass, or other oxide-based glass containing silicon oxide as a main component. Examples of soda-lime glass include tempered soda-lime glass and untempered soda-lime glass.

[0031] The glass applied to the glass plates 12 and 14 may be, for example, SiO 2 in terms of mole percentage on an oxide basis. ２ 40 to 80%, Al ２ O ３ 0-20%, Na ２ O 0-22%, K ２ It is preferable to contain 0 to 10% of O, 0 to 14% of MgO, and 0 to 15% of CaO. Each component will be explained below, with % meaning mol %.

[0032] SiO ２ is known as a component that forms a network structure in the glass microstructure, and is a major component that constitutes glass. ２ The content of SiO is preferably 40% or more, more preferably 56% or more, even more preferably 66% or more, and particularly preferably 68% or more. ２ The content of SiO is preferably 80% or less, more preferably 75% or less, and even more preferably 72% or less. ２ The content of SiO is preferably 40 to 80%, more preferably 56 to 80%, further preferably 66 to 75%, and particularly preferably 68 to 72%. ２When the content is 40% or more, the glass is advantageous in terms of stability and weather resistance. ２ When the content is 80% or less, it is advantageous in terms of solubility and moldability.

[0033] Al ２ O ３ Although not essential, Al may be contained to improve the weather resistance of the glass. It also has the effect of suppressing the penetration of tin from the bottom surface during float forming. ２ O ３ When Al is contained, it is preferably 0.1% or more, more preferably 0.6% or more, and further preferably 0.8% or more. ２ O ３ The content of Al is preferably 20% or less, more preferably 10% or less, even more preferably 5% or less, particularly preferably 3% or less, and most preferably 2% or less. ２ O ３ When it contains Al ２ O ３ The content of Al is preferably 0.1 to 20%, more preferably 0.1 to 10%, further preferably 0.6 to 5%, particularly preferably 0.6 to 3%, and most preferably 0.8 to 2%. ２ O ３ When the content of Al is 0.1% or more, the weather resistance of the glass is improved. ２ O ３ When the content is 20% or less, the devitrification temperature does not rise significantly even when the viscosity of the glass is high, which is advantageous in terms of melting and molding on a production line.

[0034] SiO ２ and Al ２ O ３ The total content of SiO ２ +Al ２ O ３ is preferably 80% or less. If it exceeds 80%, the viscosity of the glass increases at high temperatures, which may make it difficult to melt the glass. Therefore, it is preferably 76% or less, and more preferably 74% or less. ２ +Al ２ O ３It is preferable that the SiO content is 68% or more. If it is less than 68%, the crack resistance when indented decreases, and it is more preferable that the SiO content is 70% or more. ２ +Al ２ O ３ is preferably 68 to 80%, more preferably 68 to 76%, and even more preferably 70 to 74%.

[0035] Na ２ O is not essential, but is a component that reduces the high-temperature viscosity and devitrification temperature of the glass and improves the meltability and formability of the glass. ２ When O is contained, it is preferably 0.5% or more, more preferably 10% or more, and further preferably 12% or more. ２ The O content is preferably 22% or less, more preferably 16% or less, and further preferably 14% or less. ２ When the O content is 0.5% or more, sufficient solubility and moldability are obtained. ２ When the O content is 22% or less, sufficient weather resistance is obtained. ２ When O is contained, Na ２ The O content is preferably 0.5 to 22%, more preferably 10 to 16%, and even more preferably 12 to 14%.

[0036] K ２ O is not essential, but is a component that reduces the high-temperature viscosity and devitrification temperature of the glass and improves the meltability and formability of the glass. ２ When O is contained, it may be 0.1% or more, or 0.5% or more. ２ The O content is preferably 10% or less, more preferably 2% or less, and even more preferably 1% or less. ２ When the O content is 10% or less, the weather resistance is good. ２ When O is contained, K ２ The O content is preferably 0.1 to 10%, more preferably 0.1 to 2%, and even more preferably 0.5 to 1%.

[0037] Although MgO is not essential, it is a component that stabilizes the glass. The MgO content is preferably 2% or more, more preferably 4% or more, and even more preferably 6% or more. The MgO content is preferably 14% or less, more preferably 10% or less, and even more preferably 8% or less. When the MgO content is 2% or more, the chemical resistance of the glass is improved. The melting property at high temperatures is improved, and devitrification is less likely to occur. On the other hand, when the MgO content is 14% or less, the resistance to devitrification is maintained and a sufficient ion exchange rate is obtained. When MgO is contained, the MgO content is preferably 2 to 14%, more preferably 4 to 10%, and even more preferably 6 to 8%.

[0038] CaO is not essential, but may be contained to reduce the high-temperature viscosity of the glass and improve its meltability. When CaO is contained, the amount is preferably 2% or more, more preferably 5% or more, and even more preferably 7% or more. The CaO content is preferably 15% or less, more preferably 12% or less, and even more preferably 9% or less. If the CaO content is 15% or less, devitrification is unlikely to occur. When CaO is contained, the CaO content is preferably 2 to 15%, more preferably 5 to 12%, and even more preferably 7 to 9%.

[0039] SrO is not essential, but may be contained for the purpose of lowering the high-temperature viscosity of the glass and lowering the devitrification temperature. When SrO is contained, the amount of SrO is preferably 3% or less, more preferably 2% or less, and even more preferably 1% or less.

[0040] BaO is not essential, but may be contained for the purpose of lowering the high-temperature viscosity of the glass and lowering the devitrification temperature. Because BaO has the effect of increasing the specific gravity of the glass, it is preferable not to contain it when weight reduction is intended. When BaO is contained, the amount of BaO is preferably 3% or less, more preferably 2% or less, and even more preferably 1% or less.

[0041] The glass may contain other components. The total content of the other components is preferably 5% or less, more preferably 3% or less, and typically 1% or less. The other components will be described below by way of example.

[0042] ZnO may be contained in an amount of, for example, up to 2% in order to improve the meltability of the glass at high temperatures. However, when the glass is produced by the float process, ZnO is preferably not contained because it is reduced in the float bath and causes product defects.

[0043] B ２ O ３ In order to improve the melting property at high temperatures or the glass strength, Na may be contained in an amount of less than 1%. ２ O or K ２ The alkaline component of O and B ２ O ３ If B is contained at the same time, it will volatilize rapidly and significantly corrode the brick. ２ O ３ It is preferable that the material is substantially free of impurities. In this specification, the term "substantially free of impurities" means that the material is not contained except as unavoidable impurities mixed in from raw materials, etc., that is, the material is not intentionally contained.

[0044] Li ２ O is a component that lowers the strain point and makes stress relaxation more likely to occur, making it impossible to obtain a stable compressive stress. Therefore, it is preferable that O is not contained, and even if it is contained, the content is preferably less than 1%, more preferably 0.05% or less, and particularly preferably less than 0.01%.

[0045] <Silicone Resin Layer 16> The silicone resin layer 16 is an intermediate film of the laminated glass 11 and bonds the glass plates 12 and 14 together. The silicone resin layer 16 contains a silicone resin. The silicone resin layer 16 is formed by curing the silicone resin. The silicone resin layer 16 sandwiches both surfaces (the surface on the +Y direction side and the surface on the −Y direction side) of the mesh metal layer 18 except for the protruding portion 18A, and the mesh metal layer 18 does not contact the glass plates 12 and 14.

[0046] The silicone resin layer 16 is, for example, a sheet-like silicone resin layer that bonds the two glass plates 12 and 14 when viewed from the front of the laminated glass 11. The viscosity of the silicone resin constituting the silicone resin layer 16 may be constant throughout, or silicone resins of different viscosities may be used. For example, the silicone resin layer 16 may be formed by forming a frame made of a high-viscosity silicone resin on the outer edge of the main surface of the glass plate 14 on the +Y direction side, and filling the frame with a silicone resin having a lower viscosity than the silicone resin forming the frame. In this case, the bottom of the frame is the main surface of the glass plate 14 on the +Y direction side. For example, the viscosity of the silicone resin used for the frame is 60,000 mPa·s (10,000 to 100,000 mPa·s), and the viscosity of the silicone resin filled into the frame is 350 mPa·s (100 to 10,000 mPa·s).

[0047] The silicone resin layer 16 preferably has a thickness of 0.01 mm to 1 mm, more preferably 0.05 mm to 0.8 mm, and even more preferably 0.3 mm to 0.6 mm. If the thickness of the silicone resin layer 16 is 0.01 mm or more, when the mesh metal layer 18 has a mesh shape as described below, the mesh can be uniformly impregnated with the silicone resin within the surface. Furthermore, if the thickness of the silicone resin layer 16 is 1 mm or less, the silicone resin layer 16 is easy to prepare, and the viscosity is low, making it less likely for bubbles to form in the liquid silicone resin. Furthermore, since highly heat-resistant silicone resins are expensive, when using such silicone resins, a thickness of 1 mm or less for the silicone resin layer 16 can reduce costs.

[0048] The linear expansion coefficient of the silicone resin layer 16 is 1000×10 －７ / °C or less, and －７ / °C or less, and more preferably 400 x 10 －７ / °C or less. －７ / °C or less, the glass plates 12, 14 and the silicone resin layer 16 are unlikely to peel off from each other when the temperature of the glass resin laminate 10 rises. －７ / °C or more. The linear expansion coefficient of the silicone resin layer 16 is measured in accordance with JIS K 7197 (2012) using a thermomechanical analyzer (TMA). The linear expansion coefficient of the silicone resin layer 16 is 1 × 10 －７ ~1000 x 10 －７ / °C is preferred, and 1 × 10 －７ ~600 x 10 －７ / °C is more preferable, and 1 × 10 －７ ~400 x 10 －７ / °C is more preferred.

[0049] Silicone resins are classified into addition polymerization type, condensation type, etc. depending on the curing mechanism. Silicone resins can be applied to the silicone resin layer 16 regardless of their curing mechanism. Among these, addition polymerization type silicone resins are preferred. Addition polymerization type silicone resins do not generate gas when cured, so the generation of bubbles in the silicone resin layer 16 can be suppressed.

[0050] Here, as an example, the silicone resin layer 16 is described as a sheet-like silicone resin layer that bonds the two glass plates 12, 14 together in a front view of the laminated glass 11. However, as an example, the silicone resin layer 16 may be a frame-like silicone resin layer that bonds the outer edge portions of the two glass plates 12, 14 along the four sides in a front view. In this case, the silicone resin layer 16 is not present in the center portion inside the outer edge portions of the glass plates 12, 14 in a front view, so the center portion of the mesh metal layer 18 is not held by the silicone resin layer 16, and the portion of the mesh metal layer 18 that is located between the outer edge portions of the glass plates 12, 14 is held by the silicone resin layer 16.

[0051] The silicone resin of the embodiment preferably has the following properties and composition, for example.

[0052] The molecular weight of the organoalkenylpolysiloxane used in the silicone resin is preferably 1,000 to 5,000,000, more preferably 2,000 to 3,000,000, and even more preferably 3,000 to 1,000,000. The molecular weight means the weight average molecular weight and can be measured by GPC (gel permeation chromatography). Polystyrene may be used as a standard substance.

[0053] The silicone resin preferably has the following composition, for example.

[0054] The addition polymerization type silicone resin is a curable composition containing a linear organoalkenyl polysiloxane, a linear organohydrogen polysiloxane, and additives such as a catalyst, and is cured by heating to form a cured silicone resin. Specifically, the silicone resin layer 16 in this embodiment is a cured silicone resin layer formed by curing an addition polymerization type silicone resin containing a linear organopolysiloxane (a) that is a linear organoalkenyl polysiloxane and a specific linear organopolysiloxane (b) that is a linear organohydrogen polysiloxane. Generally, compared to other silicone resins, addition polymerization type silicone resins are preferred because they have a tendency to undergo a curing reaction and exhibit low cure shrinkage. The cured product of the addition polymerization type silicone resin in this embodiment exhibits particularly little change over time and excellent heat resistance. Furthermore, addition polymerization type silicone resins are generally used in the form of solvent-based, emulsion-based, and solventless compositions. Any type of composition can be used for the silicone resin in this embodiment.

[0055] As the addition polymerization type silicone resin containing linear organopolysiloxane (a) and linear organopolysiloxane (b), known ones can be used. For example, JP-A 2005-509711 (International Publication No. WO2003 / 044084) and its cited references describe addition polymerization type silicone resins for forming water-repellent, peelable silicone films on paper or plastic films. The silicone resins used to form the silicone resin layer 16 are described in detail below.

[0056] <Linear Organopolysiloxane (b)> The silicone resin in this embodiment preferably contains a linear organopolysiloxane (a) and a linear organopolysiloxane (b). Of these, the linear organopolysiloxane (b) is a type of organohydrogenpolysiloxane. The linear organopolysiloxane (b) is a linear organopolysiloxane having at least three hydrogen atoms bonded to silicon atoms per molecule, and at least one of the hydrogen atoms bonded to silicon atoms is present on a silicon atom at the molecular terminal.

[0057] In general, the monofunctional units (i.e., monovalent units) at both ends of a linear organopolysiloxane are called M units, and the difunctional units (i.e., divalent units) other than those at both ends are called D units. The structure of a linear organopolysiloxane having n D units is expressed as M(D) ｎ M. When expressing the average composition of each unit, M ２ (D) ｎ It is sometimes expressed as

[0058] In the linear organopolysiloxane (b) of this embodiment, it is preferred that at least one of the two M units has a hydrogen atom bonded to a silicon atom.More preferably, the linear organopolysiloxane (b) is a linear organopolysiloxane in which each of the two M units has a hydrogen atom bonded to a silicon atom, and some of the n D units also have a hydrogen atom bonded to a silicon atom.In addition, the linear organopolysiloxane (b) can also be used in combination with other linear organohydrogenpolysiloxanes.The other linear organohydrogenpolysiloxane is a linear organohydrogenpolysiloxane in which no M unit has a hydrogen atom bonded to a silicon atom, and only some of the D units have a hydrogen atom bonded to a silicon atom.

[0059] The linear organopolysiloxane (b) or a mixture of the linear organopolysiloxane (b) with another linear organohydrogenpolysiloxane is preferably a linear organopolysiloxane having an average composition represented by the following formula (1): Hereinafter, the organohydrogenpolysiloxane represented by this average composition formula will be referred to as organohydrogenpolysiloxane (1).

[0060] (M １ ) α (M ２ ) β (D １ ) γ (D ２ ) δ ...Equation (1) where M １ is an M unit in which there is no hydrogen atom bonded to a silicon atom, M ２ is an M unit in which a hydrogen atom bonded to a silicon atom exists, D １ is a D unit in which there is no hydrogen atom bonded to a silicon atom, and D ２ represents a D unit in which a hydrogen atom bonded to a silicon atom is present, α is a number of 0 or more and less than 2, β is a number of 2 or less but not 0, so that α + β = 2, γ is a number greater than 0, and δ is a number of 0 or more, so that γ + δ = n. In a more preferred organohydrogenpolysiloxane (1), α is a number of 0 or more and less than 1, β is a number of 1 or more and 2 or less, γ is a number of 1 or more, and δ is a number of 1 or more. The organohydrogenpolysiloxane represented by formula (5) described in WO 2007 / 018028 is a compound in which β = 0.

[0061] The linear organopolysiloxane (b) is preferably a compound in which, in the above formula (1), β is a number of 1 or more and 2 or less. More preferably, the linear organopolysiloxane (b) is a compound in which α is a number of 0 or more and less than 1, β is a number of 1 or more and 2 or less, γ is a number of 1 or more, and δ is a number of 1 or more.

[0062] M ２ The unit may have two or three hydrogen atoms bonded to the silicon atom, but preferably one. ２ The unit may have two hydrogen atoms bonded to the silicon atom, but preferably has one. １ Unit, D １Units, preferred M ２ Units, preferred D ２ The unit is preferably represented by the following formula: １ ~R ５ R each independently represents an alkyl group or a fluoroalkyl group having 4 or less carbon atoms, or a phenyl group. １ ~R ５ are preferably all methyl groups.

[0063]

[0064] D ２ If units are present (δ is not 0), D １ and D ２ The abundance ratio γ / δ is an index representing the density of hydrogen atoms bonded to silicon atoms in a molecule. This abundance ratio (γ / δ) is preferably 0.2 to 30, and particularly preferably 0.5 to 20. If this abundance ratio is too small, the amount of unreacted hydrogen atoms bonded to silicon atoms remaining in the cured silicone resin will be large, which may result in significant changes in the cured silicone resin over time and a decrease in heat resistance. On the other hand, if the abundance ratio is too large, the crosslink density of the cured silicone resin will decrease, which may result in a decrease in heat resistance.

[0065] M ２ Units and D ２ β / δ, which represents the ratio of units present, is preferably 15≦(β / δ)×1000≦1500. It is more preferable that 15≦(β / δ)×1000≦1000, and even more preferable that 15≦(β / δ)×1000≦500. If (β / δ)×1000 is less than 15, the molecular weight will be large, or the steric hindrance of the functional groups will be large, resulting in reduced reactivity and potentially reduced heat resistance. On the other hand, if (β / δ)×1000 is greater than 1500, the crosslink density will be small, potentially preventing the production of a cured silicone resin with sufficient physical properties, such as strength.

[0066] The above formula (1) represents the average composition of organosiloxane units in the organohydrogenpolysiloxane, and in the individual molecules of the linear organopolysiloxane (b), α is an integer of 0 or 1, β is an integer of 1 or 2, so that α+β=2, γ is an integer of 1 or greater, and δ is an integer of 0 or greater.

[0067] Each molecule of the organohydrogenpolysiloxane other than the linear organopolysiloxane (b) is an organohydrogenpolysiloxane in which α is 2, β is 0, γ is an integer of 0 or more, and δ is an integer of 1 or more. １ and D ２ If there are many of each, D １ and D ２ The arrangement of may be a random copolymer chain structure or a block copolymer chain structure. Since copolymer chains are usually formed by ring-opening polymerization of cyclic siloxanes, it is thought that the structure is one in which ring-opened cyclic siloxane blocks are randomly copolymerized.

[0068] As described above, the linear organopolysiloxane (b) may be not only an organohydrogenpolysiloxane in which each molecule is a linear organopolysiloxane (b), but also a mixture of the linear organopolysiloxane (b) and another organohydrogenpolysiloxane (whose average composition is represented by the above formula (1)). In this case, the linear organopolysiloxane (b) preferably accounts for 20 mol% or more of the total number of moles of the organohydrogenpolysiloxane used. If it is less than 20 mol%, hydrogen atoms bonded to silicon atoms tend to remain, which is undesirable. In order to improve the heat resistance of the cured silicone resin and the stability over time of the silicone resin layer 16, the content of the linear organopolysiloxane (b) is preferably 50 mol% or more, more preferably 80 mol% or more.

[0069] <Linear organopolysiloxane (a)> The silicone resin in this embodiment preferably contains a linear organopolysiloxane (a) that reacts with the linear organopolysiloxane (b). The linear organopolysiloxane (a) is a linear organopolysiloxane having at least two alkenyl groups per molecule. Note that, hereinafter, a linear organopolysiloxane having alkenyl groups is also referred to as an organoalkenylpolysiloxane.

[0070] The alkenyl group is not particularly limited, but examples thereof include vinyl groups (ethenyl groups), allyl groups (2-propenyl groups), butenyl groups, pentenyl groups, and hexynyl groups, and among these, vinyl groups are preferred because of their excellent heat resistance.

[0071] In the linear organopolysiloxane (a), the alkenyl group is present in the M unit or the D unit, and may be present in both the M unit and the D unit. From the viewpoint of curing speed, it is preferable that the alkenyl group is present in at least the M unit, and it is preferable that the alkenyl group is present in both the M unit and the two M units. Furthermore, in organoalkenylpolysiloxanes having alkenyl groups only in the M unit, the higher the molecular weight, the lower the alkenyl group concentration per molecule, which reduces the crosslinking density of the cured silicone resin, and this may result in a decrease in heat resistance. Therefore, it is preferable that the alkenyl group is present in not only the M unit but also some of the D unit.

[0072] The linear organopolysiloxane (a) is preferably a linear organopolysiloxane having an average composition represented by the following formula (2).

[0073] (M １ ) ａ (M ３ ) ｂ (D １ ) ｃ (D ３ ) ｄ ...Equation (2) where M １ is an M unit having no alkenyl group, M ３ is an M unit having an alkenyl group bonded to a silicon atom, D １ is a D unit having no alkenyl group, and D ３represents a D unit having an alkenyl group bonded to a silicon atom, a is a number from 0 to 2, b is a number from 0 to 2 so that a+b=2, c is a number of 0 or greater, and d is a number of 0 or greater so that c+d=n (provided that b+d is 2 or greater). In a more preferred organoalkenylpolysiloxane represented by formula (2), a is a number of 0 or greater but less than 1, b is a number of 1 or greater but 2, c is a number of 1 or greater, and d is a number of 1 or greater.

[0074] M ３ The unit may have two or three alkenyl groups bonded to the silicon atom, but preferably has one. ３ The unit may have two alkenyl groups bonded to the silicon atom, but preferably has one. The alkenyl group is preferably a vinyl group. １ Unit, D １ Units, preferred M ３ Units, preferred D ３ The unit is preferably represented by the following formula: １ ~R ５ R each independently represents an alkyl group or a fluoroalkyl group having 4 or less carbon atoms, or a phenyl group, as defined above. １ ~R ５ are preferably all methyl groups.

[0075]

[0076] The above formula (2) represents the average composition of organosiloxane units in the organoalkenyl polysiloxane. In each molecule of the linear organopolysiloxane (a), a is an integer of 0 or 1, b is an integer of 1 or 2, so that a+b=2, c is an integer of 1 or greater, and d is an integer of 0 or greater. Since the linear organopolysiloxane (a) has two or more alkenyl groups per molecule, b+d is 2 or greater. The organoalkenyl polysiloxane (a) may be a mixture with other organoalkenyl polysiloxanes, but typically only the organoalkenyl polysiloxane (a) is used. However, the organoalkenyl polysiloxane (a) may also be a mixture of two or more organoalkenyl polysiloxanes (a). The combined use of two organoalkenyl polysiloxanes with different La values ​​provides more advantageous effects.

[0077] As in the case of the organohydrogenpolysiloxane, the above formula (2) is D １ and D ３ If there are many of each, D １ and D ３ The arrangement of may be a random copolymer chain structure or a block copolymer chain structure. As the organoalkenyl polysiloxane (a), organoalkenyl polysiloxanes represented by formula (3) or (4) described in WO 2007 / 018028 can be used.

[0078] The weight average molecular weight Mw of the organoalkenylpolysiloxane (a) is preferably in the range of 1,000≦Mw≦5,000,000. More preferably, Mw is 2,000≦Mw≦3,000,000, and even more preferably, 3,000≦Mw≦1,000,000. By setting Mw within this range, volatilization during heat curing is prevented, and the viscosity does not become too high, resulting in good workability.

[0079] Furthermore, the number of alkenyl group equivalents La per 100 grams of organoalkenylpolysiloxane (a) is preferably in the range of 0.001≦La≦1.0. La is more preferably 0.0015≦La≦0.9, and even more preferably 0.002≦La≦0.9. By keeping La in this range, the heat resistance of the cured silicone resin is improved, and the stability over time of the peel strength between the cured silicone resin layer and the glass plate is improved.

[0080] The content ratio of linear organopolysiloxane (a) to linear organopolysiloxane (b) in the silicone resin is not particularly limited, but it is preferable to adjust the molar ratio of hydrogen atoms bonded to silicon atoms in linear organopolysiloxane (b) to all alkenyl groups in linear organopolysiloxane (a) (hydrogen atoms / alkenyl groups) to 0.7 to 1.05. It is particularly preferable to adjust the content ratio to 0.8 to 1.0. If the molar ratio of hydrogen atoms bonded to silicon atoms to alkenyl groups is less than 0.7, the crosslink density of the cured silicone resin will decrease, potentially resulting in problems with heat resistance, etc.

[0081] If the molar ratio of hydrogen atoms bonded to silicon atoms to alkenyl groups exceeds 1.05, there is a concern that moisture in the air will gradually penetrate from the edges of the laminate when left for a long period of time, causing hydrolysis of unreacted hydrosilyl groups (Si—H groups) in the cured silicone resin and causing some kind of reaction to proceed between the unreacted hydrogen atoms bonded to silicon atoms and silanol groups on the surface of the glass plate. Therefore, it is preferable that substantially no unreacted hydrogen atoms bonded to silicon atoms remain in the silicone resin layer 16.

[0082] <Other Components> The silicone resin in this embodiment may contain various additives as needed, provided that the effects of the present invention are not impaired. It is generally preferable to use a catalyst (addition polymerization catalyst) that promotes the reaction between a hydrogen atom bonded to a silicon atom and an alkenyl group as the additive. It is preferable to use a platinum group metal catalyst as this catalyst. Examples of platinum group metal catalysts include platinum-based, palladium-based, and rhodium-based catalysts, with platinum-based catalysts being particularly preferred from the standpoints of economy and reactivity. Known platinum catalysts can be used. Specific examples include platinum fine powder, platinum black, chloroplatinic acid such as chloroplatinic acid and chloroplatinic acid, platinum tetrachloride, alcohol compounds of chloroplatinic acid, aldehyde compounds, or platinum olefin complexes, alkenylsiloxane complexes, and carbonyl complexes.

[0083] The catalyst is preferably present in an amount of 2 to 400 ppm, more preferably 5 to 300 ppm, and even more preferably 8 to 200 ppm, based on the total mass of the linear organopolysiloxane (a) and the linear organopolysiloxane (b).

[0084] In the silicone resin of this embodiment, it is preferable to use an activity inhibitor (a compound also called a reaction inhibitor, retarder, etc.) that acts to suppress catalytic activity in order to adjust the catalytic activity together with the catalyst. Examples of the activity inhibitor include various organic nitrogen compounds, organic phosphorus compounds, acetylene compounds, oxime compounds, organic chloro compounds, etc. Furthermore, if necessary, inorganic fillers such as various silicas, calcium carbonate, iron oxide, etc. may be contained within a range that does not impair the effects of the present invention.

[0085] <Mesh metal layer 18> The mesh metal layer 18 is a mesh-shaped metal layer, and is made of stainless steel (SUS steel), for example. As shown in Fig. 3, most of the mesh metal layer 18 is provided inside the silicone resin layer 16 and is held by the silicone resin layer 16. An end (protruding portion 18A) of the mesh metal layer 18 on the -X direction side protrudes outside the silicone resin layer 16.

[0086] Both surfaces (the surface on the +Y direction side and the surface on the −Y direction side) of the mesh metal layer 18 other than the protruding portion 18A are sandwiched between the silicone resin layer 16, and the mesh metal layer 18 is not in contact with the glass plates 12, 14.

[0087] As an example, the mesh metal layer 18 has a plain weave configuration of metal wires extending in two orthogonal directions (e.g., the X direction and the Z direction) when viewed from the front. The openings of the plain weave mesh metal layer 18 are square when viewed from the front. As an example, a mesh for screen printing can be used as this mesh metal layer 18. The maximum length of the openings of the mesh metal layer 18 is sufficiently shorter than the wavelength in free space of the 2.45 GHz microwaves used in the microwave oven 100. Therefore, the mesh metal layer 18 can shield microwaves and has electromagnetic wave shielding performance equivalent to that of punched metal.

[0088] There are no limitations on the material or shape of the mesh metal layer 18, as long as it is mesh-shaped and can block microwaves. Furthermore, it is preferable that the mesh metal layer 18 has durability that prevents deformation or other changes even when used continuously for one day or more in an environment of 350° C., for example, in order to avoid affecting the silicone resin layer 16.

[0089] As the material for the mesh metal layer 18, in addition to stainless steel (SUS steel), metals such as iron, copper, brass, aluminum, nickel, tungsten, nichrome, or the like, which are represented by simple metal elements or alloys, can be used.

[0090] The mesh metal layer 18 preferably has a thickness of 0.001 mm to 0.5 mm, more preferably 0.01 mm to 0.2 mm, and even more preferably 0.01 mm to 0.1 mm. If the thickness of the mesh metal layer 18 is 0.001 mm or more, it is less likely to break. Furthermore, if the thickness of the mesh metal layer 18 is 0.500 mm or less, the mesh metal layer 18 can be impregnated with silicone resin.

[0091] The mesh metal layer 18 can improve the visible light transmittance of the glass resin laminate 10. The transparency of the glass resin laminate 10 is increased, and the opposite side of the glass resin laminate 10 can be easily seen.

[0092] The mesh shape is a mesh shape in which openings 22 are formed by a plurality of metal wires 20. The openings 22 shown in Fig. 5 are formed, for example, by weaving the plurality of wires 20. Note that the weaving method of the plurality of wires 20 is not particularly limited. When the mesh metal layer 18 has a mesh shape, it is preferable that the formed openings 22 penetrate the mesh metal layer 18.

[0093] The mesh-shaped mesh metal layer 18 preferably has a wire diameter D (wire diameter of the wire material 20) of 0.001 mm to 0.1 mm and a void ratio of 5% to 90%, more preferably a wire diameter D (wire diameter of the wire material 20) of 0.010 mm to 0.05 mm and a void ratio of 10% to 80%, and even more preferably a wire diameter D (wire diameter of the wire material 20) of 0.03 mm to 0.1 mm and a void ratio of 60% to 80%. A mesh-shaped mesh metal layer 18 within the above ranges can improve the visible light transmittance of the glass resin laminate 10. Here, the void ratio is the ratio of the area of ​​the openings 22 in the mesh metal layer 18 to the total area of ​​the multiple metal wire materials 20 and the openings 22 in the mesh metal layer 18, and is synonymous with the opening ratio.

[0094] Although the shape of the openings 22 in the mesh metal layer 18 is shown as a square, the shape is not particularly limited and can be, for example, a polygon including a triangle, rectangle, rhombus, trapezoid, etc., or a curved shape including a circle, ellipse, etc.

[0095] FIG. 6 is a diagram showing actual measurement examples of the wire diameter D, mesh density, inter-wire distance, space ratio, and visible light transmittance of the mesh metal layer 18 in a plurality of samples of the glass resin laminate 10.

[0096] The wire diameter D is the diameter of the wire. The mesh density is the number of wires 20 per 2.54 cm (1 inch) in each of the X and Z directions. As an example, the mesh metal layer 18 has the same number of wires 20 per 2.54 cm (1 inch) in the X direction as the number of wires 20 per 2.54 cm (1 inch) in the Z direction. The wire spacing is the pitch between adjacent wires 20.

[0097] As an example, when the wire diameter D was 30 μm, the mesh density was 100, and the wire spacing was 0.23 mm, the void ratio was 77.8% and the visible light transmittance was 78.6%. When the wire diameter D was 50 μm, the mesh density was 100, and the wire spacing was 0.21 mm, the void ratio was 64.5% and the visible light transmittance was 61.8%. When the wire diameter D was 80 μm, the mesh density was 50, and the wire spacing was 0.44 mm, the void ratio was 71.0% and the visible light transmittance was 60.6%.

[0098] When the wire diameter D was 100 μm, the mesh density was 40, and the wire spacing was 0.55 mm, the void ratio was 71.0% and the visible light transmittance was 67.9%. When the wire diameter D was 100 μm, the mesh density was 50, and the wire spacing was 0.42 mm, the void ratio was 64.5% and the visible light transmittance was 59.1%. When the wire diameter D was 120 μm, the mesh density was 40, and the wire spacing was 0.53 mm, the void ratio was 65.8% and the visible light transmittance was 60.0%.

[0099] Taking into consideration the measurement examples of samples other than those mentioned above, it has been found that the mesh metal layer 18 preferably has a void ratio of 60% or more and 80% or less.

[0100] <Blackening Treatment of Mesh Metal Layer 18> The surface of mesh metal layer 18 is preferably blackened by oxidation, painting, or plating. The blackening treatment is preferably applied to at least the exterior surface of mesh metal layer 18, and may be applied to both the exterior and interior surfaces of mesh metal layer 18. The reason that the blackening treatment is preferably applied to at least the exterior surface of mesh metal layer 18 is that the mesh metal layer 18 becomes less noticeable when the interior of microwave oven 100 is viewed from the outside (outside), thereby improving visibility of the interior. If the interior of microwave oven 100 is clearly visible from the outside, it is easier to check items placed inside from the outside of microwave oven 100. Furthermore, the reason that the blackening treatment makes mesh metal layer 18 less noticeable is that reflection on the surface of mesh metal layer 18 is reduced.

[0101] However, if the reflection on the metal surface is sufficiently low (visible light reflectance is low), the mesh metal layer 18 does not need to have a blackened treatment layer formed on the surface by blackening treatment.

[0102] <Blackening Treatment by Oxidation> When blackening treatment is performed by oxidizing the surface of the mesh metal layer 18, the surface of the mesh metal layer 18 can be oxidized by electrochemical coloring or the like, causing an oxide film present on the surface to grow electrochemically and develop a black color. Furthermore, high-temperature oxidation may be performed by raising the temperature of the mesh metal layer 18 during oxidation. In these cases, the blackening treatment layer is an oxide layer that develops a black color.

[0103] <Blackening Treatment by Painting> When a black coating film is formed on the surface of the mesh metal layer 18 by blackening treatment, the blackened layer is a black coating film. For example, the black coating film may be a film in which PTFE (Poly Tetra Fluoro Ethylene) paint is applied to the surface of the mesh metal layer 18. PTFE is suitable for use as a black coating film because it has high heat resistance and excellent durability. Furthermore, when a black coating film is formed on the surface of the mesh metal layer 18 by blackening treatment, for example, the black coating film may be a black coating film formed by electrodeposition coating, powder coating, or dip coating.

[0104] Electrodeposition coating is a coating method in which the mesh metal layer 18 is immersed in a tank containing water-soluble paint and a direct current is passed through the mesh metal layer 18 as the anode or cathode to form a coating film. Powder coating is a coating method in which a powder paint is directly applied to the mesh metal layer 18, heated, dried, and hardened to form a coating film. Dip coating is a chemical conversion coating method in which the mesh metal layer 18 is immersed in a treatment bath to form a coating film.

[0105] <Blackening Treatment by Plating> When blackening treatment by plating is performed on the surface of the mesh metal layer 18, for example, a chrome plating layer may be formed as the blackening treatment layer to make the surface of the mesh metal layer 18 black.

[0106] <Visible Light Reflectance of the Surface of Mesh Metal Layer 18> As described above, the visible light reflectance of the surface of the mesh metal layer 18 is preferably 15% or less, and if blackening treatment is performed, it is preferably 5% or less. By performing blackening treatment, the reflection of the surface of the mesh metal layer 18 is reduced.

[0107] The visible light reflectance of the surface of the mesh metal layer 18 can be measured, for example, as follows: A material having the same composition as the blackened layer is laminated on a plate to a thickness equal to the thickness of the blackened layer. The plate is a member made of the same material as the metallic substrate of the mesh metal layer 18. The reflection intensity when light having a wavelength of 400 nm or more and 700 nm or less is incident perpendicularly on the surface of the plate having the same composition as the blackened layer is measured using a reflectance measuring device based on the SCI (Specular Component Include) method. The SCI method includes specular reflection light. In this way, the visible light reflectance of the surface of the mesh metal layer 18 can be measured.

[0108] The mesh metal layer 18 in each of the multiple samples of the glass resin laminate 10 shown in Figure 6 is made of stainless steel (SUS304 steel), and a blackened layer is formed by oxidizing the surface through electrochemical coloring. The mesh metal layer shown in Figure 6, which has a wire diameter D of 30 μm, a mesh density of 100, a wire spacing of 0.23 mm, and a space ratio of 77.8%, had a surface visible light reflectance of 3.12%. On the other hand, the visible light reflectance of a mesh metal layer made of stainless steel (SUS304 steel) with the same wire diameter D, mesh density, wire spacing, and space ratio but not subjected to blackening treatment was 12.56%. By applying the blackening treatment, the reflection of the surface of the mesh metal layer 18 was reduced. Six samples of the glass resin laminate 10 shown in Figure 6 use reinforced soda lime glass as the two glass plates 12, 14, the main surfaces of which are bonded together by a silicone resin layer 16, and the mesh metal layer 18 is held in place by the silicone resin layer 16. Samples were prepared using the mesh metal layer 18 of stainless steel (SUS304 steel) that had not been blackened, and had the same wire diameter D, mesh density, inter-wire distance, and void ratio as these samples. Ten subjects were asked to evaluate the visibility of the mesh metal layer 18 due to the blackening treatment. The subjects fitted each of the six samples of the glass resin laminate 10 shown in Figure 6 and six samples that had not been blackened into the opening of a microwave oven, and evaluated whether the state of tableware placed in the oven and the state of food being cooked were easily visible. As a result, all 10 subjects rated all six samples with blackened mesh metal layer 18 as easier to see the state of dishes placed inside the microwave oven and the state of food being cooked than the six samples without blackening treatment. It is thought that blackening treatment reduces the visible light reflectance of the surface of mesh metal layer 18, making it easier to see the inside of the microwave oven.

[0109] 3 and 4 , the glass resin laminate 10 of this embodiment has a protruding portion 18A where the mesh metal layer 18 protrudes from the end of the silicone resin layer 16. The protruding portion 18A is a region of the mesh metal layer 18 that is not covered by the silicone resin layer 16. The protruding portion 18A is electrically connected to the metal frame 111 (see FIG. 2 ) and is held at ground potential. Therefore, the mesh metal layer 18 is held at ground potential.

[0110] Since the glass resin laminate 10 includes the silicone resin layer 16, the temperature can be raised up to 300°C during heating in the microwave oven 100.

[0111] Next, a preferred embodiment of the glass resin laminate 10 will be described. The ratio (Tr / Tm) of the thickness Tr of the silicone resin layer 16 to the thickness Tm of the mesh metal layer 18 is preferably in the range of 1 to 5, more preferably in the range of 1 to 3, and even more preferably in the range of 1 to 2. By setting the ratio (Tr / Tm) in the above range, warping of the glass resin laminate 10 can be suppressed.

[0112] Meanwhile, a mesh metal layer 18 is disposed on the silicone resin layer 16 of the glass resin laminate 10. Because the mesh metal layer 18 has a smaller linear expansion coefficient than the silicone resin layer 16, the mesh metal layer 18 acts to reduce dimensional change in the silicone resin layer 16 due to heat. By adjusting the ratio of the thickness Tm of the mesh metal layer 18 to the thickness Tr of the silicone resin layer 16, the apparent linear expansion coefficient of the silicone resin layer 16 can be reduced. As a result, the difference in the linear expansion coefficient between the glass plates 12, 14 and the silicone resin layer 16 is reduced, and warping of the glass resin laminate 10 can be suppressed.

[0113] The difference between the linear expansion coefficient of the glass plates 12 and 14 and the linear expansion coefficient of the silicone resin layer 16 is 1000×10 －７ / °C or less, and －７ / °C or less, and more preferably 400 x 10 －７ / °C or less. The difference from the linear expansion coefficient means an absolute value. If the difference in linear expansion coefficient is within the above-mentioned range, warping of the glass resin laminate 10 can be suppressed. By suppressing warping of the glass resin laminate 10, the glass plates 12, 14 and the silicone resin layer 16 are less likely to peel from each other, and further, when the glass plates 12, 14 are supported by a frame, the glass plates 12, 14 are less likely to come off from the frame.

[0114] The surface compressive stress of the silicone resin layer 16 of the glass resin laminate 10 is preferably 500 MPa or less, more preferably 300 MPa or less, and even more preferably 100 MPa or less. If the surface compressive stress of the silicone resin layer 16 is 500 MPa or less, the difference with the surface compressive stress of the glass plates 12, 14 becomes small, and the glass resin laminate 10 is less likely to warp. The smaller the surface compressive stress of the silicone resin layer 16, the better. There is no particular lower limit, but it may be 0 MPa or more, 1 MPa or more, or 10 MPa or more. The surface compressive stress of the silicone resin layer 16 is measured using a thin film stress measuring device (e.g., FLX-2320-S manufactured by Toho Technology Co., Ltd.). The surface compressive stress of the silicone resin layer 16 is preferably 0 to 500 MPa, more preferably 1 to 300 MPa, and even more preferably 10 to 100 MPa.

[0115] It is preferable that the two glass plates 12, 14 of the glass resin laminate 10 have the same thickness. By making the two glass plates 12, 14 have the same thickness, there is almost no difference in the linear expansion coefficient between the glass plates 12, 14 sandwiching the silicone resin layer 16. Therefore, warping of the glass resin laminate 10 caused by the difference in linear expansion coefficient is suppressed. Having the same thickness includes completely the same thickness and the same thickness with a tolerance as specified in JIS (Japanese Industrial Standards) R3202:2011.

[0116] The two glass plates 12, 14 of the glass resin laminate 10 may have different thicknesses. When the glass resin laminate 10 is used as a window, if a thicker glass plate 12 (or 14) is used on the outside, impact resistance when an object hits the glass plate can be improved. If a thicker glass plate 12 (or 14) is used on the inside, heat resistance can be improved. "Different plate thicknesses" means anything other than the above-mentioned "same plate thickness."

[0117] <Method for manufacturing glass resin laminate> Next, an example of a method for manufacturing the glass resin laminate 10 will be described with reference to Fig. 7 to Fig. 10. Two glass plates 12, 14 are prepared, and a mesh metal layer 18 is arranged on the main surface of one of the two glass plates 12, 14, the glass plate 14, as shown in Fig. 7. The mesh metal layer 18 may be arranged in contact with the main surface of the glass plate 14, or may be arranged at a certain distance from the main surface of the glass plate 14. Fig. 7 shows an arrangement in which the mesh metal layer 18 is spaced apart.

[0118] 8, a pre-prepared silicone resin 16A is applied to the mesh metal layer 18. The silicone resin 16A is applied to the entire main surface of the glass plate 14. On the other hand, the silicone resin 16A is not applied to the areas where the protruding portions 18A of the mesh metal layer 18 are to be formed. It is preferable to remove any air bubbles present in the silicone resin 16A.

[0119] Next, as shown in Figure 9, the other glass plate 12 is bonded to one of the glass plates 14 with the silicone resin 16A and the mesh metal layer 18 sandwiched between them. The bonding is performed by aligning one side of the glass plate 12 and the glass plate 14, and disposing the glass plate 12 and the glass plate 14 at an angle rather than parallel to each other. The bonding is performed, for example, by using one side as a fulcrum and gradually moving the glass plate 12 closer to the glass plate 14. This makes it easier for air bubbles to escape from the silicone resin 16A. When aligning one side of the glass plate 12 and the glass plate 14, aligning the short sides makes it easier to remove air bubbles.

[0120] 10, the silicone resin 16A is cured to form the silicone resin layer 16. The silicone resin 16A is cured, for example, by being placed in an environment of 40°C to 80°C for 1 to 15 hours, and then at 100°C to 200°C for 1 to 12 hours, thereby forming the silicone resin layer 16. In the method for producing a glass resin laminate, any or all of the processes may be carried out in a reduced pressure environment as necessary.

[0121] By curing under the above-mentioned environment, the silicone resin layer 16 can achieve a surface compressive stress of 0 MPa to 500 MPa.

[0122] Both surfaces (the surface on the +Y direction side and the surface on the −Y direction side) of the mesh metal layer 18 other than the protruding portion 18A are sandwiched between the silicone resin layer 16, and the mesh metal layer 18 is not in contact with the glass plates 12, 14.

[0123] <Effects> The glass resin laminate 10 includes at least two glass plates 12, 14, a silicone resin layer 16 disposed between the two glass plates 12, 14 and bonding the main surfaces of the two glass plates 12, 14 together, and a mesh metal layer 18 held by the silicone resin layer 16, the mesh metal layer 18 having a mesh shape. The mesh metal layer 18 is inconspicuous and allows easy viewing of the opposite side.

[0124] Therefore, it is possible to provide a glass resin laminate 10 that has a metal layer (mesh metal layer 18) that can shield electromagnetic waves from devices that use electromagnetic waves and that allows easy viewing of the opposite side through the metal layer (mesh metal layer 18). In particular, when the glass resin laminate 10 is used as the opening / closing door 110 of a microwave oven 100, microwaves can be shielded by the glass resin laminate 10, and the inside of the microwave oven can be easily seen through the glass resin laminate 10 from outside, making it easy to check objects inside the microwave oven.

[0125] Furthermore, mesh metal layer 18 may have a black coating film on the surface. This makes mesh metal layer 18 less noticeable, making it easier to see the opposite side through the metal layer (mesh metal layer 18). In particular, when glass resin laminate 10 is used as door 110 of microwave oven 100, the interior of the microwave oven becomes easier to see through glass resin laminate 10 from outside the microwave oven, making it easier to check objects inside the microwave oven.

[0126] The black coating film may also be a film coated with PTFE paint. PTFE paint coatings have high heat resistance and durability, and are easy to apply. This makes it easy to produce a glass resin laminate 10 in which the opposite side is very visible through the metal layer (mesh metal layer 18). In particular, when the glass resin laminate 10 is used as the opening / closing door 110 of a microwave oven 100, it is easy to produce a glass resin laminate 10 in which the interior of the microwave oven is very visible through the glass resin laminate 10 from outside the microwave oven, making it easier to identify objects inside the microwave oven.

[0127] Furthermore, the surface of the mesh metal layer 18 may be subjected to a blackening treatment by oxidation, painting, or plating. By subjecting the metal layer (mesh metal layer 18) to a blackening treatment, the mesh metal layer 18 becomes less noticeable, making it possible to produce a glass resin laminate 10 in which the opposite side is easily visible through the glass resin laminate 10. In particular, when the glass resin laminate 10 is used as the opening / closing door 110 of a microwave oven 100, it is possible to produce a glass resin laminate 10 in which the interior of the microwave oven is very easily visible through the glass resin laminate 10 from outside the microwave oven, making it easier to check objects inside the microwave oven.

[0128] Furthermore, the visible light reflectance of the mesh metal layer 18 may be 15% or less. When the visible light reflectance of the mesh metal layer 18 is extremely low, the mesh metal layer 18 becomes less noticeable, and it is therefore possible to produce a glass resin laminate 10 in which the opposite side is easily visible through the glass resin laminate 10. In particular, when the glass resin laminate 10 is used as the opening / closing door 110 of a microwave oven 100, it is possible to produce a glass resin laminate 10 in which the interior of the microwave oven is very easily visible through the glass resin laminate 10 from outside the microwave oven, making it easier to check objects inside the microwave oven.

[0129] Furthermore, the mesh metal layer 18 may have a void ratio of 60% or more and 80% or less. A high void ratio of the mesh metal layer 18 makes the mesh metal layer 18 less noticeable, making it possible to produce a glass resin laminate 10 that makes it easy to see the opposite side through the glass resin laminate 10. In particular, when the glass resin laminate 10 is used as the opening / closing door 110 of a microwave oven 100, it is possible to produce a glass resin laminate 10 that makes it very easy to see the inside of the microwave oven through the glass resin laminate 10 from outside the microwave oven, making it easier to check objects inside the microwave oven.

[0130] The silicone resin layer 16 may also be a frame-shaped silicone resin layer 16 that joins the outer edges of the two glass plates 12 and 14. The amount of silicone resin used to form the silicone resin layer 16 can be reduced.

[0131] The glass resin laminate 10 may also be used as a door for opening and closing a microwave heating device. The glass resin laminate 10 can block microwaves generated inside a microwave heating device such as a microwave oven 100, and the inside of the device can be easily seen from the outside through the glass resin laminate 10, making it easy to check the state of objects inside the device.

[0132] The method for manufacturing the glass resin laminate 10 includes preparing two glass plates 12, 14, placing a mesh metal layer 18 on the main surface of one of the two glass plates 12, 14, applying a silicone resin to the mesh metal layer 18, sandwiching the silicone resin and mesh metal layer 18 between the other of the two glass plates 12, 14 and the one of the two glass plates 12, 14, and bonding them together, and curing the silicone resin to form a silicone resin layer 16 that is disposed between the two glass plates 12, 14 and bonds the main surfaces of the two glass plates 12, 14, and the mesh metal layer 18 has a mesh shape. The mesh metal layer 18 is inconspicuous and easy to see from the opposite side.

[0133] Therefore, it is possible to provide a method for manufacturing a glass resin laminate 10 that has a metal layer (mesh metal layer 18) that can block electromagnetic waves from a device that uses electromagnetic waves, and that allows easy viewing of the opposite side through the metal layer (mesh metal layer 18).

[0134] The exemplary glass resin laminate and the method for manufacturing the glass resin laminate according to the present disclosure have been described above. However, the present disclosure is not limited to the specifically disclosed embodiments, and various modifications and changes are possible without departing from the scope of the claims.

[0135] REFERENCE SIGNS LIST 10 Glass resin laminate 11 Laminated glass 12, 14 Glass plate (at least two glass plates, or an example of two glass plates) 16 Silicone resin layer 18 Mesh metal layer (an example of a metal layer having a mesh shape) 20 Wire rod 22 Opening 100 Microwave oven 110 Openable door 111 Metal frame 112 Outer glass

Claims

1. A glass resin laminate comprising: at least two glass plates; a silicone resin layer disposed between the two glass plates and bonding the main surfaces of the two glass plates together; and a metal layer held by the silicone resin layer, wherein the metal layer has a mesh shape.

2. The glass resin laminate according to claim 1, wherein the metal layer has a black coating film on the surface.

3. The glass resin laminate according to claim 2, wherein the black coating film is a film coated with PTFE paint.

4. The glass resin laminate according to claim 1, wherein the surface of the metal layer is subjected to a blackening treatment by oxidation, painting, or plating.

5. The glass resin laminate according to claim 1, wherein the reflectance of the metal layer is 15% or less.

6. The glass resin laminate according to claim 1, wherein the metal layer has a void ratio of 60% or more and 80% or less.

7. The glass resin laminate according to claim 1, wherein the silicone resin layer is a frame-shaped silicone resin layer that joins the outer edges of the two glass plates together.

8. The glass resin laminate according to any one of claims 1 to 7, which is used as an opening and closing door of a microwave heating device.

9. A method for manufacturing a glass resin laminate, comprising: preparing two glass plates; disposing a metal layer on a main surface of one of the two glass plates; applying a silicone resin to the metal layer; sandwiching the silicone resin and the metal layer between the other of the two glass plates and the one of the two glass plates and bonding them together; curing the silicone resin to form a silicone resin layer that is disposed between the two glass plates and bonds the main surfaces of the two glass plates together; and the metal layer has a mesh shape.

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