WO2017090690A1 - Laminated glass, window glass for automobiles, and window glass for buildings - Google Patents

Abstract

This laminated glass (1) is provided with a first glass sheet (10), a first transparent adhesive layer (16), a transparent heat-insulation layer (14) having independent pores without shells, a second transparent adhesive layer (18), and a second glass sheet (12), in that order. The value of A in formula (1), namely A=D³Pd_i, is not more than 6.4 ×10⁵, and the value of B in formula (2) is at least 35 (in the formulae, D is the pore size (nm), P is the porosity, d_i is the thickness (mm) of the transparent heat-insulation layer, d_g is the total (mm) thickness of the glass sheets, and d_a is the total (mm) thickness of the transparent adhesive layers).

Description

Laminated glass, automotive window glass and building window glass

The present invention relates to laminated glass, automotive window glass and building window glass.

Laminated glass with two glass plates bonded together with an intermediate film is excellent in penetration resistance, and even when broken, there is little scattering of glass fragments, so window glass for vehicles, window glass for buildings, etc. It is used as.
As a laminated glass, there is known a laminated glass provided with an infrared reflection layer or an infrared absorption layer on an intermediate film in order to suppress a temperature rise in a vehicle or a room due to solar radiation (Patent Documents 1 to 4).

However, laminated glass with an infrared reflecting layer or infrared absorbing layer on the interlayer can block infrared rays that enter from outside the vehicle or from the outside of the vehicle, but it cannot block heat conducted through the laminated glass itself. There is a problem in that outdoor heat flows through the laminated glass through the laminated glass and flows into the vehicle and the room, and in winter, heat from inside and indoor heating flows through the laminated glass and flows out of the vehicle and the outdoor.

A laminated glass that blocks heat conducted through the laminated glass itself, that is, has a heat insulating property, is composed of a first layer containing hollow silica fine particles and a second layer and a third layer sandwiching the interlayer. Has been proposed (Patent Document 5).

International Publication No. 2013/168714 Japanese Patent No. 4848872 Japanese Unexamined Patent Publication No. 2007-148330 Japanese Unexamined Patent Publication No. 2010-222233 International Publication No. 2012/063881

However, in the laminated glass of Patent Document 5, the first layer containing the hollow silica fine particles is designed to be thin in order to maintain the transmittance, so that the thermal conductivity is high and the heat insulation is insufficient.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides laminated glass, automobile window glass and building window glass that have high transparency and excellent heat insulation.

The present invention has the following aspects.
<1> A first glass plate, a first transparent adhesive layer, a transparent heat-insulating layer having independent pores, a second transparent adhesive layer, and a second glass plate in order, wherein the independent pores The pores are directly covered with a matrix without passing through the shell, and the A value represented by the following formula (1) is 6.4 × 10 ⁵ or less, and is represented by the following formula (2). Laminated glass whose B value is 35 or more.

Where D is the pore size (nm) of the independent pores of the transparent heat insulation layer, P is the porosity of the transparent heat insulation layer, d _i is the thickness (mm) of the transparent heat insulation layer, and d _g is the first the sum of the thickness and the thickness of the second glass plate of the glass plate (mm), d _a is the total thickness of the first transparent adhesive layer thickness and a second transparent adhesive layer (mm) .
<2> The laminated glass according to <1>, wherein the A value is 2.3 × 10 ⁵ or less and the B value is 85 or more.
<3> The laminated glass according to <1> or <2>, wherein the transparent elastic layer has a compression elastic modulus of 4.3 MPa or more.
<4> The laminated glass according to any one of <1> to <3>, wherein the transparent heat insulating layer is a foamed resin sheet.
<5> The laminated glass according to any one of <1> to <4>, wherein the transparent heat insulating layer has a thickness of 0.2 to 10 mm.
<6> The laminated glass according to any one of <1> to <5>, wherein the thickness of the first glass plate and the thickness of the second glass plate are 0.1 to 6 mm, respectively.
<7> The laminated glass according to any one of <1> to <6>, wherein the thickness of the first transparent adhesive layer and the thickness of the second transparent adhesive layer are 0.1 to 3 mm, respectively.
<8> An automotive window glass comprising the laminated glass according to any one of <1> to <7>.
<9> A window glass for buildings comprising the laminated glass of any one of <1> to <7>.

The laminated glass, the window glass for automobiles and the window glass for buildings of the present invention have high transparency and excellent heat insulation.

FIG. 1 is a cross-sectional view showing an example of the laminated glass of the present invention.

The following definitions of terms apply throughout this specification and the claims.
The “pore” means a hole made of a void formed in the heat insulating material.
“Independent pores” means pores that are completely covered with a matrix or shell around each pore. Independent pores include independent pores that are directly covered with a matrix without passing through a shell, and independent pores that are formed by hollow particles having shells dispersed in the matrix. There are pores. The independent pores in the present invention are the former independent pores.
“Transparent” means that light can be transmitted.
“Pore diameter” is a value obtained by observing 100 pores in a cross section of a heat insulating layer using a transmission microscope and calculating a simple average of major and minor diameters when the pores are regarded as an ellipse (ie, 200 numerical values). Average).
“Porosity” is a value obtained by the following equation from the volume of the transparent heat insulating layer before pressing and the volume of the transparent heat insulating layer after pressing under the conditions of temperature: 200 ° C., pressure: 35 MPa, time: 10 minutes. is there.
Porosity = 1− (Volume of transparent heat insulating layer after pressing / Volume of transparent heat insulating layer before pressing)
“Transmittance” is a value measured in accordance with JIS R 3106: 1998 “Testing method for transmittance, reflectance, emissivity, and solar heat gain of plate glass” (ISO 9050: 1990).
“Heat transmissivity (U value)” is defined in JIS R 3107: 1998 “Method of calculating thermal resistance of sheet glass and heat transmissivity in architecture” (ISO 10292: 1994) and JIS R 3209: 1998 “Multilayer glass”. It is a value measured in compliance.
The “compressive modulus” is a value measured in accordance with JIS K 7181: 2011 “Plastics—How to obtain compression properties” (ISO 604: 2002).

<Laminated glass>
FIG. 1 is a cross-sectional view showing an example of the laminated glass of the present invention.
The laminated glass 1 includes a first glass plate 10; a second glass plate 12; a transparent heat insulating layer 14 having independent pores disposed between the first glass plate 10 and the second glass plate 12. A first transparent adhesive layer 16 that bonds the first glass plate 10 and the transparent heat insulating layer 14; and a second transparent adhesive layer 18 that bonds the second glass plate 12 and the transparent heat insulating layer 14 Have.

(Glass plate)
The material of the first glass plate and the second glass plate (hereinafter collectively referred to as a glass plate) may be an inorganic glass or an organic glass, and has weather resistance, rigidity, and solvent resistance. In view of the above, inorganic glass is preferable. The materials of the first glass plate and the second glass plate may be the same or different.
Examples of the inorganic glass include soda lime glass, borosilicate glass, non-alkali glass, and quartz glass. Soda lime glass is preferable.
Examples of the organic glass include polycarbonate and acrylic resin.

The glass plate may be a colorless transparent glass plate or a colored transparent glass plate, and is preferably a heat ray absorbing glass plate (blue glass plate or green glass plate) rich in iron.
As the glass plate, a tempered glass plate may be used to enhance safety. As the tempered glass plate, a tempered glass plate obtained by an air cooling tempering method or a chemical tempering method can be used.

The shape of the glass plate may be curved or flat. Since the window glass for automobiles is often curved, when the laminated glass of the present invention is used as the window glass for automobiles, the shape of the glass plate is often curved.

The thickness of the glass plate is preferably 0.1 to 6 mm, more preferably 1 to 3 mm. The thicknesses of the first glass plate and the second glass plate may be the same or different. In addition, the thickness of the glass plate in this invention is geometric thickness. Hereinafter, the same applies to the thickness of each layer of the laminated glass of the present invention other than the glass plate.

(Transparent adhesive layer)
The material of the first transparent adhesive layer and the second transparent adhesive layer (hereinafter collectively referred to as a transparent adhesive layer) may be any transparent resin that can adhere the glass plate and the transparent heat insulating layer. Examples of the transparent resin include polyvinyl butyral, ethylene-vinyl acetate copolymer, and commercially available optically clear adhesive (OCA), and polyvinyl butyral and ethylene-vinyl acetate copolymer are preferable. Polyvinyl butyral is more preferable for applications requiring penetration resistance such as window glass. The materials of the first transparent adhesive layer and the second transparent adhesive layer may be the same or different. Each transparent adhesive layer may be a laminate of two or more layers of the same or different types.

The transparent adhesive layer may contain an infrared absorber, an ultraviolet absorber, an antioxidant, a light stabilizer, a colorant and the like within a range not impairing the effects of the present invention.
The thickness of the transparent adhesive layer is preferably from 0.1 to 3 mm, and more preferably from 0.3 to 0.8 mm. The thickness of the first transparent adhesive layer and the second transparent adhesive layer may be the same or different.

(Transparent insulation layer)
The compressive elastic modulus of the transparent heat insulating layer is preferably 4.3 MPa or more, more preferably 12 MPa or more, and further preferably 120 MPa or more. When the compression modulus is equal to or higher than the lower limit of the above range, the transparent heat insulating layer is excellent in mechanical strength and can withstand compression when bonded to a glass plate during the production of laminated glass.

The thickness of the transparent heat insulating layer is preferably 0.2 to 10 mm, more preferably 0.5 to 6 mm, and further preferably 1 to 3 mm. If the thickness of a transparent heat insulation layer is more than the lower limit of the said range, it will be further excellent in the heat insulation of a laminated glass. If the thickness of a transparent heat insulation layer is below the upper limit of the said range, the transparency of a laminated glass will become still higher.

The transparent heat insulating layer has independent pores (hereinafter also referred to as independent pores without a shell or simply independent pores) directly covered with a matrix without passing through a shell.
Examples of the transparent heat insulating layer having independent pores without a shell include a foamed resin sheet; a sheet in which generation of nanobubbles is fixed.

As the transparent heat insulating layer, a foamed resin sheet is preferable from the viewpoint that both transparency and heat insulating properties of the laminated glass are easily achieved, manufacturing is easy, and cost is low.

(Foamed resin sheet)
The foamed resin sheet is a sheet in which independent pores are formed by foaming in a matrix made of a resin material.

Examples of the resin contained in the resin material include amorphous thermoplastic resins, crystalline thermoplastic resins, and cured products of curable resins.
Amorphous thermoplastic resins include polystyrene, polymethyl methacrylate, polycarbonate, amorphous polyester resin, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene copolymer, norbornene resin, amorphous fluororesin, Examples include polyether sulfone, polysulfone, polyether imide, polyarylate, polyester carbonate, triacetyl cellulose, and amorphous nylon resin.
Examples of the crystalline thermoplastic resin include polypropylene, polyethylene, polyvinyl chloride, crystalline polyester resin, crystalline fluororesin, poly-4-methylpentene-1, and the like.
Examples of the curable resin include epoxy resin, diethylene glycol biscarbonate, polyfunctional acrylate resin, and polyfunctional methacrylate resin.

As long as the effect of the present invention is not impaired, the resin material is a foam nucleating agent, a colorant, an antioxidant, a light stabilizer, a mold release agent, an antiseptic, an infrared absorber, an ultraviolet absorber, a plasticizer, and a flame retardant. , A conductivity imparting agent, an antistatic agent, a crystal nucleating agent and the like may be contained.

The foamed resin sheet can be produced by a known method using a foaming agent, and it is easy to produce a foamed resin sheet having high transparency and excellent heat insulation properties. A method of exposing the film to an inert gas or its supercritical fluid and then releasing the pressure at once; introducing an inert gas or its supercritical fluid into the extruder, and the pressure when the resin is extruded from the die It is preferable to manufacture by a method using a foaming method that utilizes the fact that is released at once. When importance is placed on productivity, a method of introducing an inert gas or a supercritical fluid thereof into the extruder is more preferable.

The method is a method for producing a foamed resin sheet by impregnating a resin material with an inert gas or a supercritical fluid thereof at a specific pressure and a specific temperature and then releasing the pressure.
Examples of the inert gas include carbon dioxide and nitrogen. The inert gas is often impregnated into the resin material as a supercritical fluid under heating and pressurization.

When the resin is an amorphous thermoplastic resin, the impregnation temperature is lower than the glass transition temperature of the amorphous thermoplastic resin, and the amorphous thermoplastic resin is sufficiently impregnated with an inert gas (hereinafter, referred to as “amorphous thermoplastic resin”). A temperature higher than the glass transition temperature of the amorphous thermoplastic resin in the saturated impregnation state) is preferable.
When the resin is a crystalline thermoplastic resin, the impregnation temperature is preferably lower than the melting point of the crystalline thermoplastic resin and higher than the melting point of the crystalline thermoplastic resin in the saturated impregnation state.
When the resin is a cured product of a curable resin, the impregnation temperature is preferably lower than the glass transition temperature of the cured product of the curable resin and higher than the glass transition temperature of the cured product of the curable resin in the saturated impregnation state. .
If the impregnation temperature is at least the lower limit of the above range, the gas diffusibility is improved and the impregnation time of the inert gas can be shortened. If the impregnation temperature and the temperature at which the pressure is released are not more than the upper limit of the above range, the pore diameter of the independent pores can be reduced.

The impregnation pressure is preferably 8 to 50 MPa, more preferably 15 to 30 MPa. If the impregnation pressure is not less than the lower limit of the above range, the gas diffusibility can be improved, the impregnation time of the inert gas can be shortened, and the porosity of the foamed resin sheet can be increased. If the impregnation pressure is not more than the upper limit of the above range, the pore diameter of the independent pores can be reduced.

The impregnation time is preferably a time that allows the gas concentration in the matrix to be uniform. Depending on the type of resin material and the thickness of the resin sheet, it is preferably 0.5 to 12 hours, more preferably 1 to 2 hours. . If the impregnation time is not less than the lower limit of the above range, the porosity of the foamed resin sheet can be increased. If the impregnation time is less than or equal to the upper limit of the above range, productivity is excellent.

(Design of transparent heat insulation layer)
By making A value and B value mentioned later into a specific range, coexistence of transparency and heat insulation of a laminated glass can be achieved by adjusting the pore diameter and porosity of the independent pores of the transparent heat insulation layer.
The porosity is the pore diameter multiplied by the number density of the pores. The pore diameter of the independent pores without the shell is the viscosity (impregnation temperature) of the resin material when the resin material is impregnated with an inert gas or its supercritical fluid, the decompression speed (decompression time) when the pressure is released, etc. Depends on. The number density depends on the concentration (impregnation pressure) of the inert gas impregnated in the resin material or its supercritical fluid.

Therefore, in order to reduce the pore diameter of the independent pores without shells in the transparent heat insulating layer, for example, the impregnation temperature when the resin material is impregnated with an inert gas or its supercritical fluid is lowered to increase the viscosity of the resin material. The pressure reduction rate when releasing the pressure may be reduced.
In order to increase the porosity of the transparent heat insulation layer without changing the pore diameter of the independent pores without shells in the transparent heat insulation layer, it is necessary to increase the number density. What is necessary is just to raise the impregnation pressure at the time of impregnating gas or its supercritical fluid.

Obtaining a transparent heat insulating layer having independent pores without a shell having a compression modulus of 4.3 MPa or more can be achieved by increasing the compression modulus of the matrix to 6.8 MPa or more. It can also be achieved by reducing the pore diameter of the independent pores without a shell.

(A value)
The laminated glass of the present invention has an A value represented by the following formula (1) of 6.4 × 10 ⁵ or less, preferably 2.3 × 10 ⁵ or less, more preferably 1.0 × 10 ⁵ or less. .
When the A value is 6.4 × 10 ⁵ or less, the transmittance of the laminated glass is 50% or more. If the A value is 2.3 × 10 ⁵ or less, the transmittance of the laminated glass is 70% or more.

The reason why the transmittance of the laminated glass is 50% or more when the A value is 6.4 × 10 ⁵ or less, and the transmittance of the laminated glass is 70% when the A value is 2.3 × 10 ⁵ or less. The reason for this will be described below.

About laminated glass having a layer structure as shown in FIG. 1, air (0th layer), first glass plate (first layer), first transparent adhesive layer (second layer), transparent heat insulating layer (third layer) ), Thickness of second transparent adhesive layer (fourth layer), second glass plate (fifth layer) and air (sixth layer), refractive index, cumulative transmittance, Fresnel reflection and internal transmittance, As shown in Table 1.

First, the transmittance of the transparent heat insulation layer necessary for the transmittance of the laminated glass is determined. The purpose of this derivation is to obtain a relational expression as to what the transmittance T ₃ of the transparent heat insulating layer needs to be when the required numerical value of the transmittance S ₆ of the laminated glass is designated.

Regarding the Fresnel reflection, for example, the Fresnel reflection F ₁ at the interface between the layer having the refractive index n _{1 and} the layer having the refractive index n ₂ is expressed by the following equation.

When the cumulative transmittance S ₀ of the incident side air is 1, the cumulative transmittance of each layer is expressed by the following formula (3).

Since the purpose is to obtain the relationship between S ₆ and T ₃ , when the expression (3) is transformed by paying attention to T ₃ , it is expressed by the following expression (4). Here, it is assumed that F ₀ = F ₅ , F ₁ = F ₄ , and F ₂ = F ₃ .

Since the glass plate and the transparent adhesive layer are sufficiently transparent at a thickness of about 10 mm or less, T ₁ , T ₂ , T ₄ , and T ₅ can be approximated to 1. Therefore, Formula (4) is represented by the following Formula (5).

At a wavelength of 500 nm, the refractive indexes n ₁ and n ₅ of a normal glass plate and the refractive indexes n ₂ and n ₄ of the transparent adhesive layer are about 1.5. On the other hand, the refractive index of the transparent heat-insulating layer varies depending on the material, if you put the same n _{3 =} 1.0 and air as the worst case, does not occur a problem even if the logic on any. Therefore, Fresnel reflection at each interface can be approximated as follows.

Therefore, equation (5) is expressed by the following equation.

Here, when T ₃ is the transmittance of the transparent heat insulating layer and T _i is set, and S ₆ is the transmittance of the laminated glass and T _L is set, this formula is expressed by the following formula (6).

By the equation (6), the transmittance T _i of the transparent heat insulating layer necessary for the transmittance T _L of the laminated glass to be realized can be calculated.

Next, the relationship between the pore diameter D of the independent pores of the transparent heat insulating layer, the porosity P of the transparent heat insulating layer, the thickness d _i of the transparent heat insulating layer, and the transmittance _TL of the laminated glass is obtained.

The transmittance T _i of the transparent heat insulation layer is expressed as follows: the incident light intensity to the transparent heat insulation layer is I ₀ , the transmitted light intensity from the transparent heat insulation layer is I, the scattering cross section of the independent pores of the transparent heat insulation layer is σ, the number of pores per unit volume N, and the thickness of the transparent heat insulating layer and _d i (mm), is represented by the following formula (7) (polymer Collected papers, Vol.67, No.7, pp.390 -396 (2010)).

Rayleigh scattering is applied when the pore size of the independent pores of the transparent heat insulation layer is smaller than the wavelength of light. Accordingly, the scattering cross-sectional area σ is expressed by the following equation, where the pore diameter is D (mm) and the wavelength is λ (nm).

The number N of pores per unit volume of the transparent heat insulation layer is expressed by the following formula.

When the unit (m) is unified and the equation (7) is arranged, it is expressed by the following equation (8).

Here, when the proportionality constant is set to C, the equation (8) is further expressed by the following equations (9), (10), and (11). Expressions (9), (10), and (11) are equivalent.

Substituting equation (6) into equation (10) yields the following equation (12).

Actually, a laminated glass with various conditions is prepared, D, P, d _i , transmittance _TL at a wavelength of 500 nm are measured, and these values are substituted into equation (12) to obtain the value of C. When calculated, the results in Table 2 were obtained. The wavelength does not have to be 500 nm, but is easily affected by impurities at shorter wavelengths, and the influence of scattering is less visible at longer wavelengths. Therefore, it evaluated by the value of transmittance _{TL at} a wavelength of 500 nm.

The value of C obtained from the actual measurement value was averaged to obtain a value of C = 5.1 × 10 ⁻⁵ . Therefore, Formula (12) is represented by the following Formula (13).

For example, when the transmittance _TL of the laminated glass is 50%, the numerical values in parentheses in the formula (13) are as follows.

Therefore, when the wavelength is fixed at 500 nm, in order for the transmittance _TL of the laminated glass to satisfy 50% or more, the pore diameter D of the independent pores of the transparent heat insulation layer, the porosity P of the transparent heat insulation layer, and the transparent heat insulation It can be seen that the thickness d _{i of the} layer should be in the relationship of the following formula (14).

Similarly, in order for the transmittance _TL of the laminated glass to satisfy 70% or more, the relationship of the following formula (15) is sufficient. The unit of A value is nm ³ mm.

(B value)
In the laminated glass of the present invention, the B value represented by the following formula (2) is 35 or more, and preferably 85 or more.
When the B value is 35 or more, the heat flow rate (U value) of the laminated glass, which is a measure of heat insulation, is 5.0 W / m ² K or less. If the B value is 85 or more, the U value of the laminated glass is 4.0 W / m ² K or less.

Why U value of the laminated glass by the B value of 35 or more is less than 5.0W / ^{m 2} K, and B values of the laminated glass by 85 or more U value 4.0 W ^{/ m} 2 K The reason for the following will be described below.

The thermal conductivity of the laminated glass is U (W / m ² K), the outdoor surface heat transfer coefficient is h _ext (W / m ² K), and the indoor surface heat transfer coefficient is h _in (W / m ² K). ), R (m ² K / W) for the thermal resistance of each layer, d _g (mm) for the total thickness of the two glass plates, λ _g (W / mK) for the thermal conductivity of the glass plate, transparent adhesion The total thickness of the layers is d _a (mm), the thermal conductivity of the transparent adhesive layer is λ _a (W / mK), the thickness of the transparent heat insulation layer is d _i (mm), and the heat conductivity of the transparent heat insulation layer is λ _{If i} (W / mK), it is represented by the following formula (16).

The thermal conductivity of air at room temperature is λ _air (0.026 W / mK), the mean free path is L (62.5 × 10 ⁻⁹ m), the pore diameter of the independent pores of the transparent heat insulation layer is D (mm), When the thermal conductivity of the independent pores is λ _pore (W / mK), these relationships are expressed by the following equation (17) (G. Wei et al., International Journal of Heat and Mass Transfer (2011) 54, 2355-2366).

Thermal conductivity λ _i of the transparent insulation layer, _mat the thermal conductivity of the matrix of transparent thermal insulation layer λ _{(W /} mK), the porosity of the transparent thermal insulation layer and is P, Japan University of Industrial Technology 37th (2004 Academic Lecture Meeting Applied Molecular Chemistry Group Program 5-8 “Measurement of thermal conductivity of gas hydrate simulated sediment sample” Using equation (17), b is a proportional constant Is done.

The hemispherical emissivity ε _ext of the outdoor member surface is 0.837 W / m ² K, and the hemispherical emissivity ε _in of the indoor member surface is 0.837 W / m ² K. The surface heat transfer coefficient h _ext and the indoor surface heat transfer coefficient h _in are as follows.

The thermal conductivity λ _g of the glass plate is approximately 1.0 W / mK even if the glass type is different, and the thermal conductivity λ _a of the material used for the transparent adhesive layer is approximately 0.3 W / mK. . Further, the thermal conductivity λ _mat of the transparent heat insulating layer matrix can be set to 1.0 W / mK as the worst case. From these, when unit (m) is unified and equation (16) is arranged, it is expressed by the following equation (18).

When organizing equation (18) and placing it as B, it is represented by the following equation (19).

When formula (19) is transformed with respect to b, it is represented by the following formula (20).

Actually, a laminated glass with various conditions is prepared, D, P, d _i , d _g , d _a , and U values are measured, and these values are substituted into equation (20) to obtain the value of b The results in Table 3 were obtained.

The value of b obtained from the actual measurement value was averaged to obtain a value of b = 0.235. Therefore, Expression (19) is expressed by Expression (21) below by substituting the value of b.

For example, when the U value is 5.0 W / m ² K, the B value is as follows.

Therefore, in order to satisfy the U value of 5.0 W / m ² K or less, the pore diameter D of the independent pores of the transparent heat insulating layer, the porosity P of the transparent heat insulating layer, the thickness d _i of the transparent heat insulating layer, total d _{g thickness,} total d _a thickness of the transparent adhesive layer, it can be seen that it is sufficient to relation of the following equation (22).

Similarly, in order to satisfy the U value of 4.0 W / m ² K or less, the relationship of the following expression (23) is sufficient. The unit of B value is mm.

(Characteristics of laminated glass)
The transmittance of light having a wavelength of 500 nm of the laminated glass is preferably 50% or more, more preferably 70 to 99%, and further preferably 70 to 96%. If the transmittance | permeability of the light of wavelength 500nm is more than the lower limit of the said range, the transparency of a laminated glass will become high. It is difficult to produce a laminated glass having a light transmittance of a wavelength of 500 nm exceeding the upper limit of the above range.

The heat transmissivity (U value) of the laminated glass is preferably 5.8 W / m ² K or less from the viewpoint of improving fuel efficiency since the current laminated glass for automobiles is 5.8 W / m ² K. More preferable is 0.0 W / m ² K or less.

The thickness of the laminated glass is preferably 2 to 20 mm, more preferably 3 to 10 mm, and even more preferably 4 to 6 mm. If the thickness of the laminated glass is not less than the lower limit of the above range, the heat insulating property of the laminated glass is further improved, and the mechanical strength is also excellent. If the thickness of a laminated glass is below the upper limit of the said range, a laminated glass will not become too heavy and it is excellent also in transparency.

(Laminated glass manufacturing method)
Laminated glass can be produced by a known method. For example, a second glass plate, a transparent resin sheet to be a second transparent adhesive layer, a transparent heat insulating sheet to be a transparent heat insulating layer, a transparent resin sheet to be a first transparent adhesive layer, and a first glass plate are sequentially stacked. After these are temporarily bonded, they can be manufactured by main bonding by heating and pressing. At this time, the transparent resin sheet serving as the first transparent adhesive layer and the transparent resin sheet serving as the second transparent adhesive layer may each be the same type or may be composed of two or more different types of sheets. Good.

(Other forms)
The laminated glass of the present invention comprises a first glass plate, a first transparent adhesive layer, a transparent heat insulating layer having independent pores without a shell, a second transparent adhesive layer, and a second glass plate in this order. And the A value is 6.4 × 10 ⁵ or less and the B value is 35 or more, and is not limited to the illustrated example.

For example, the laminated glass of this invention may have a 3rd glass plate or more glass plates as needed.
The laminated glass of this invention may have functional layers other than a transparent heat insulation layer, such as an infrared absorption layer and an ultraviolet absorption layer.

(Mechanism of action)
In the laminated glass of the present invention described above, since the temperature rise in the vehicle and the room can be suppressed by the transparent heat insulating layer having independent pores, a metal thin film for suppressing the temperature increase in the vehicle and the room due to solar radiation is provided. There is no need. Therefore, it has radio wave permeability.
Moreover, in the laminated glass of this invention, since A value is 6.4x10 < ⁵ > or less, transparency is high.
Moreover, in the laminated glass of this invention, since B value is 35 or more, a heat transmissivity (U value) will be 5.0 W / m < ² > K or less, and it is excellent in heat insulation.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

(Independent pore size)
The pore diameter of the independent pores in the transparent heat insulation layer is a simple average of the major and minor diameters when 100 pores are observed using a transmission microscope (manufactured by JEOL Ltd., JEM-1230) and regarded as an ellipse. Is a calculated value (that is, an average of 200 numerical values).

(Porosity of transparent heat insulation layer)
It calculated | required by the following Formula from the volume of the transparent heat insulation layer before pressing, and the volume of the transparent heat insulation layer after pressing on the conditions of temperature: 200 degreeC, pressure: 35MPa, time: 10 minutes.
Porosity = 1− (Volume of transparent heat insulating layer after pressing / Volume of transparent heat insulating layer before pressing)

(Compressive elastic modulus of transparent heat insulation layer)
The compression elastic modulus of the transparent heat insulation layer is based on JIS K 7181: 2011 (ISO 604: 2002) for the transparent heat insulation sheet before bonding, and is a desktop precision universal testing machine (manufactured by Shimadzu Corporation, Autograph AGS-5kNX) ).

(Transmissivity of laminated glass)
The transmittance of light with a wavelength of 500 nm of the laminated glass was measured using a spectrophotometer (manufactured by Shimadzu Corporation, SolidSpec-3700DUV) in accordance with JIS R 3106: 1998 (ISO 9050: 1990).

(Heat transmissivity (U value))
The U value of the laminated glass was measured using HC-074 / 630 manufactured by Eihiro Seiki Co., Ltd. in accordance with JIS R 3107: 1998 and JIS R 3209: 1998.

(Crush resistance)
The presence or absence of compressive deformation of the transparent heat insulation layer at the time of bonding with a glass plate was confirmed.
○: No compression deformation.
X: There is compression deformation.

(A value)
About the A value calculated | required from Formula (1), it determined by the following reference | standard.
A: A value is 2.3 × 10 ⁵ or less.
A: A value is more than 2.3 × 10 ^{5 and} 6.4 × 10 ⁵ or less.
X: A value exceeds 6.4x10 < ⁵ >.

(B value)
About the B value calculated | required from Formula (2), it determined by the following reference | standard.
A: B value is 85 or more.
○: B value is 35 or more and less than 85.
X: B value is less than 35.

(Comprehensive judgment)
Based on the transmittance and U value of the laminated glass, a comprehensive judgment was made based on the following criteria.
A: The transmittance is 70% or more and the U value is 4.0 W / m ² K or less.
○: The transmittance is 50% or more and the U value is 5.0 W / m ² K or less.
X: The transmittance is less than 50% or the U value is less than 5.0 W / m ² K.

Example 1
A polycarbonate film having a thickness of 0.4 mm (manufactured by AGC Polycarbonate) was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 120 ° C. The pressure was adjusted to maintain 20 MPa. The film was impregnated with supercritical carbon dioxide by holding for 3 hours. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 10 seconds to obtain a foamed resin sheet having a thickness of 1.2 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

Using a foamed resin sheet as a transparent heat insulation layer, both sides are sandwiched between 0.38mm thick polyvinyl butyral (PVB) films, and both sides are sandwiched between 1.6mm thick soda lime glass (Asahi Glass Co., Ltd.), which is then used in vacuum packaging bags Then, vacuum suction was performed, air remaining at the interface of each layer was degassed, and temporarily bonded at 120 ° C. for 30 minutes to obtain a laminate. Next, the laminate was put in an autoclave and was finally bonded at 120 ° C. and 1.3 MPa for 90 minutes to obtain a laminated glass. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

(Example 2)
A polycarbonate film having a thickness of 0.5 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 110 ° C. The pressure was adjusted so as to maintain 26 MPa. The film was impregnated with supercritical carbon dioxide by holding for 1 hour. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 5 seconds to obtain a foamed resin sheet having a thickness of 1.3 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

A foamed resin sheet was used as a transparent heat insulating layer, both sides were sandwiched between 0.76 mm thick PVB films, and both sides were sandwiched between 1.0 mm thick soda lime glass to produce a laminated glass in the same manner as in Example 1. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

(Example 3)
A polycarbonate film having a thickness of 2.0 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 95 ° C. The pressure was adjusted to maintain 25 MPa. The film was impregnated with supercritical carbon dioxide by holding for 5 hours. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 10 seconds to obtain a foamed resin sheet having a thickness of 5.8 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

A foamed resin sheet was used as a transparent heat insulating layer, both sides were sandwiched between PVB films having a thickness of 0.1 mm, both sides were sandwiched between soda lime glasses having a thickness of 2.0 mm, and laminated glass was produced in the same manner as in Example 1. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

Example 4
A 0.2 mm thick polycarbonate film (manufactured by AGC Polycarbonate) was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 100 ° C. The pressure was adjusted so as to maintain 26 MPa. The film was impregnated with supercritical carbon dioxide by holding for 1 hour. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 5 seconds to obtain a foamed resin sheet having a thickness of 0.5 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

The foamed resin sheet is used as a transparent heat insulating layer, and both sides are sandwiched between a PVB film having a thickness of 0.26 mm and a PVB film having a thickness of 0.5 mm. Further, both sides of the sheet are 1.0 mm thick soda lime glass and 3.0 mm thick soda. Laminated glass was prepared by the same method as in Example 1 by sandwiching with lime glass. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

(Example 5)
A polymethyl methacrylate (PMMA) film having a thickness of 0.5 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 70 ° C. The pressure was adjusted to maintain 28 MPa. The film was impregnated with supercritical carbon dioxide by holding for 1 hour. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 5 seconds to obtain a foamed resin sheet having a thickness of 1.2 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

The foamed resin sheet is used as a transparent heat insulation layer, and both sides are sandwiched between two 0.38mm thick PVB films and four 0.76mm thick PVB films, and both sides are sandwiched between 2mm thick soda lime glass. A laminated glass was produced in the same manner as in Example 1. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

(Example 6)
A PMMA film having a thickness of 0.4 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 80 ° C. The pressure was adjusted so as to maintain 26 MPa. The film was impregnated with supercritical carbon dioxide by holding for 1 hour. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 5 seconds to obtain a foamed resin sheet having a thickness of 1.1 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

A foamed resin sheet was used as a transparent heat insulating layer, both sides were sandwiched between 0.38 mm thick PVB films, and both sides were sandwiched between 2.0 mm thick soda lime glass to produce a laminated glass in the same manner as in Example 1. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

(Example 7)
A PMMA film having a thickness of 0.8 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 75 ° C. The pressure was adjusted to maintain 28 MPa. The film was impregnated with supercritical carbon dioxide by holding for 3 hours. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 5 seconds to obtain a 2.5 mm thick foamed resin sheet. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

Using a foamed resin sheet as a transparent heat insulating layer, both sides were sandwiched between PVB films having a thickness of 0.38 mm, and both sides were sandwiched between soda lime glasses having a thickness of 6.0 mm. A laminated glass was produced in the same manner as in Example 1. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

(Example 8)
A PMMA film having a thickness of 0.4 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 85 ° C. The pressure was adjusted to maintain 25 MPa. The film was impregnated with supercritical carbon dioxide by holding for 1 hour. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 5 seconds to obtain a foamed resin sheet having a thickness of 1.2 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

A foamed resin sheet was used as a transparent heat insulating layer, both sides were sandwiched between 0.38 mm thick PVB films, and both sides were sandwiched between 2.0 mm thick soda lime glass to produce a laminated glass in the same manner as in Example 1. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

Example 9
A polystyrene film having a thickness of 0.5 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 60 ° C. The pressure was adjusted so as to maintain 16 MPa. The film was impregnated with supercritical carbon dioxide by holding for 5 hours. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 1 minute to obtain a foamed resin sheet having a thickness of 1.1 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

A foamed resin sheet was used as a transparent heat insulating layer, both sides were sandwiched between 0.38 mm thick PVB films, and both sides were sandwiched between 2.0 mm thick soda lime glass to produce a laminated glass in the same manner as in Example 1. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

(Example 10)
A polystyrene film having a thickness of 0.4 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 50 ° C. The pressure was adjusted so as to maintain 26 MPa. The film was impregnated with supercritical carbon dioxide by holding for 5 hours. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 1 minute to obtain a foamed resin sheet having a thickness of 0.8 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

A foamed resin sheet was used as a transparent heat insulating layer, both sides were sandwiched between 0.76 mm thick PVB films, and both sides were sandwiched between 6.0 mm thick soda lime glass to produce a laminated glass in the same manner as in Example 1. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

(Comparative Example 1)
A polycarbonate film having a thickness of 0.3 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 130 ° C. The pressure was adjusted to maintain 10 MPa. The film was impregnated with supercritical carbon dioxide by holding for 1 hour. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 5 seconds to obtain a foamed resin sheet having a thickness of 1.2 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

A foamed resin sheet was used as a transparent heat insulating layer, both sides were sandwiched between 0.38 mm thick PVB films, and both sides were sandwiched between 2.0 mm thick soda lime glass to produce a laminated glass in the same manner as in Example 1. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

(Comparative Example 2)
A PMMA film having a thickness of 0.5 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 100 ° C. The pressure was adjusted to maintain 20 MPa. The film was impregnated with supercritical carbon dioxide by holding for 3 hours. While maintaining the temperature, the pressure vessel valve was opened and the pressure was released to atmospheric pressure over 5 seconds to obtain a 2.0 mm thick foamed resin sheet. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

A foamed resin sheet was used as a transparent heat insulating layer, both sides were sandwiched between 0.38 mm thick PVB films, and both sides were sandwiched between 2.0 mm thick soda lime glass to produce a laminated glass in the same manner as in Example 1. While confirming that a transparent heat insulation layer is not compressively deformed when bonding with a glass plate, the transmittance | permeability and U value of the laminated glass were measured. The results are shown in Table 4.

(Comparative Example 3)
An ethylene-vinyl acetate copolymer (EVA) film having a thickness of 0.4 mm was prepared. The film was placed in a pressure vessel, and liquefied carbon dioxide was supplied into the pressure vessel with a pump and heated to 50 ° C. The pressure was adjusted so as to maintain 26 MPa. The film was impregnated with supercritical carbon dioxide by holding for 3 hours. While maintaining the temperature, the valve of the pressure vessel was opened and the pressure was released to atmospheric pressure over 5 seconds to obtain a foamed resin sheet having a thickness of 1.1 mm. The pore diameter of closed cells in the foamed resin sheet, the porosity of the foamed resin sheet, and the compression modulus were measured.

A foamed resin sheet was used as a transparent heat insulating layer, both sides were sandwiched between 0.38 mm thick PVB films, and both sides were sandwiched between 2.0 mm thick soda lime glass to produce a laminated glass in the same manner as in Example 1. The transparent heat insulation layer was crushed and whitened when it was bonded to the glass plate. The results are shown in Table 4.

(Comparative Example 4)
Without putting the transparent heat insulation layer, one PVB film having a thickness of 0.76 mm was sandwiched between two 2.0 mm-thick soda lime glasses, and a laminated glass was produced in the same manner as in Example 1. The transmittance and U value of the laminated glass were measured. The results are shown in Table 4.

The laminated glasses of Examples 1 to 10 having an A value of 6.4 × 10 ⁵ or less and a B value of 35 or more had high transparency and excellent heat insulation.
The laminated glass of Comparative Example 1 having an A value of over 6.4 × 10 ⁵ and a B value of less than 35 had low transparency and poor heat insulation.
The laminated glass of Comparative Example 2 having an A value exceeding 6.4 × 10 ⁵ had low transparency and poor heat insulation.
The laminated glass of Comparative Example 3 having a B value of less than 35 was inferior in heat insulating properties.
In the laminated glass of Comparative Example 3 in which the compressive elastic modulus of the transparent heat insulating layer was less than 4.3 MPa, the transparent heat insulating layer was crushed and whitened when bonded to the glass plate, and the transmittance was low.
The laminated glass of Comparative Example 4 not provided with a transparent heat insulating layer was inferior in heat insulating properties.

This application is based on Japanese Patent Application No. 2015-2331012 filed on Nov. 26, 2015, the contents of which are incorporated herein by reference.

The laminated glass of the present invention includes automotive window glass (windshield, roof window, elevating window, side fixing window, backlight, roof window, etc.), vehicle window glass such as railcar window glass, and building window glass. Useful as such.

DESCRIPTION OF SYMBOLS 1 Laminated glass 10 1st glass plate 12 2nd glass plate 14 Transparent heat insulation layer 16 1st transparent contact bonding layer 18 2nd transparent contact bonding layer

Claims (9)

A first glass plate, a first transparent adhesive layer, a transparent heat insulating layer having independent pores, a second transparent adhesive layer, and a second glass plate in order;
The independent pores are pores directly covered with a matrix without a shell around the pores;
The A value represented by the following formula (1) is 6.4 × 10 ⁵ or less,
Laminated glass having a B value represented by the following formula (2) of 35 or more.

Where D is the pore size (nm) of the independent pores of the transparent heat insulation layer, P is the porosity of the transparent heat insulation layer, d _i is the thickness (mm) of the transparent heat insulation layer, and d _g is the first the sum of the thickness and the thickness of the second glass plate of the glass plate (mm), d _a is the total thickness of the first transparent adhesive layer thickness and a second transparent adhesive layer (mm) . The A value is 2.3 × 10 ⁵ or less,
The laminated glass according to claim 1, wherein the B value is 85 or more. The laminated glass according to claim 1 or 2, wherein the compression elastic modulus of the transparent heat insulating layer is 4.3 MPa or more. The laminated glass according to any one of claims 1 to 3, wherein the transparent heat insulating layer is a foamed resin sheet. The laminated glass according to any one of claims 1 to 4, wherein the transparent heat insulating layer has a thickness of 0.2 mm to 10 mm. The laminated glass according to any one of claims 1 to 5, wherein a thickness of the first glass plate and a thickness of the second glass plate are 0.1 mm to 6 mm, respectively. The laminated glass according to any one of claims 1 to 6, wherein the thickness of the first transparent adhesive layer and the thickness of the second transparent adhesive layer are 0.1 mm to 3 mm, respectively. An automotive window glass comprising the laminated glass according to any one of claims 1 to 7. A window glass for buildings comprising the laminated glass according to any one of claims 1 to 7.

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