JPH10297944A - Plural layer glass panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a low-pressure plural layer glass panel having excellent heat insulating performances without damage of film even in a plate glass provided with a specific metal film of low normal emittance, by laying a dotted, linear or netlike spacer between two sheets of plate glass and sealing the peripheral part with a sealing material composed of an organic polymer-based material to form a low-pressure space between the two sheets of the plate glass. SOLUTION: Preferably one of two sheets of plate glass is plate glass of low irradiation glass coated with a specific metal film so as to improve heat insulating performances. A material for a spacer for maintaining a gap between two sheets of plate glass is preferably a metal, a ceramic or a plastic having a lower hardness than glass and proper compression strength. A sealing material for the peripheral part is an organic polymer material such as a polyisoprene, silicone, polyamide, etc., satisfying conditioning of water vapor transmission rate and oxygen permeability. Especially when a low-molecular weight material is released, an adsorbent such as a silica gel, activated carbon or activated soil is added to the organic polymer material. The gap between the sheets of the plate glass is 0.5-2 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to energy saving in the fields of construction such as housing and non-housing, transportation such as automobiles, vehicles, ships, and aircraft, and equipment such as freezers, freezer showcases, and constant temperature and humidity chambers. The present invention relates to a low-pressure double-glazed glass panel having high heat insulating performance applied to an opening that requires the following.

[0002]

2. Description of the Related Art In recent years, in order to create a comfortable and healthy living environment with excellent energy saving, double glazing having heat insulation performance has been used more frequently than ever before and has been rapidly spreading.

As this double-glazed glass panel, there has been proposed a double-glazed glass panel in which a space formed by facing glass sheets is reduced in pressure. For example, Japanese Unexamined Patent Publication No. 5-501896 discloses that two low-pressure spaces are interconnected by a peripheral joint of molten solder glass and a plurality of columns arranged with an outer coating of molten solder glass. Insulated glass panels composed of sheet glass have been proposed.

For example, Japanese Patent Publication No. Hei 7-508967 discloses that
It consists of two spaced apart glass panes enclosing a low-pressure space and joined together by an array of peripheral joints and columns of fused solder glass, and at least some of these columns are made entirely of metal. Certain thermally insulating glass panels have been proposed.

For example, Japanese Patent Application Laid-Open No. 6-17579 discloses that
Parallel plates made of two glass sheets are spaced at a predetermined interval,
A spacer made of low-melting glass or porcelain that maintains this space is fused and disposed with low-melting glass, and the end of the parallel plate is a low-melting material, for example,
A vacuum heat insulating glass plate has been proposed in which a low-melting glass or a low-melting alloy is fused and adhered to form a vacuum space.

For example, Japanese Patent Application Laid-Open No. Hei 8-133795 discloses that
There has been proposed a composite glass plate having a structure in which a sheet glass provided with projections having a constant height is overlapped on a surface having projections, an outer peripheral portion is airtightly bonded with an adhesive to form a space, and the space is evacuated.

[0007]

For example, in the above-mentioned insulated glass panel disclosed in Japanese Patent Publication No. 5-501896, the peripheral edge of the glass is sealed with molten solder glass. Because of its poor chemical durability as pointed out in JP-A-6-17579, it is difficult to adopt it for architectural applications immersed in rainwater such as acid rain, which has recently become a cause of environmental destruction. . Further, since the molten solder glass and the sheet glass have different coefficients of thermal expansion, breakage due to generation of thermal stress becomes a problem in a hot summer environment or a high temperature environment of an environmental tester. Further, a method of sealing the peripheral edge of the glass with the molten solder glass and a method of connecting the two glass sheets to each other with a plurality of columns coated with the molten solder glass are pointed out in Japanese Patent Publication No. Hei 7-508967. At the time of panel manufacture, the strut is damaged by the atmospheric pressure,
Molten solder glass, which is a brittle material, cannot absorb impact loads caused by earthquakes, winds, etc., and is therefore difficult to use for architectural and vehicle applications. In addition, since the gas exhaust means includes a complicated process of processing an exhaust port or the like into glass, the cost is high.

For example, in the heat insulating glass panel described in Japanese Patent Application Laid-Open No. 7-508967, at least some of the columns in the heat insulating glass panel described in Japanese Patent Application Laid-Open No. 7-508967 are completely made of metal. By doing so, improvements have been made to prevent the columns from being damaged by atmospheric pressure during panel manufacturing, to absorb impact loads due to earthquakes, winds, and the like, and to prevent damage due to the generation of thermal stress. However, there is no change or improvement in sealing the peripheral edge of the glass with molten solder glass, so the problem of poor chemical durability remains, so buildings that are immersed in rainwater such as acid rain It is difficult to adopt for use. Further, in an extremely hot summer environment or a high-temperature environment of an environmental tester, breakage due to generation of thermal stress still remains as a problem.

For example, in the vacuum heat insulating glass described in Japanese Patent Application Laid-Open No. 6-17579, when the peripheral edge of the glass is sealed with molten solder glass, it is further coated with a weather-resistant low-melting alloy to form a molten solder. We are trying to solve the problem of poor chemical durability of glass, but sealing the peripheral edge of the glass with molten solder glass, and fusing the spacer made of low melting glass or ceramic with low melting glass. No change or improvement has been made in the method of connecting the two glass sheets to each other.
As pointed out in the official gazette, there is a problem that the columns are damaged by the atmospheric pressure during panel manufacturing, and that the molten solder glass, which is a brittle material, cannot absorb impact loads due to earthquakes, winds, etc. It is difficult to adopt for use.

[0010] For example, in the vacuum composite glass plate described in JP-A-8-133795, glass spheres are scattered as spacers, but since the distance between the glass spheres is not controlled, the density of the glass spheres is low. In some parts, the sheet glass may come into contact or break.

Further, as the adhesive for sealing the peripheral edge, glass having a lower melting point than plate glass or spacer is used. However, since this is inferior in chemical durability as already pointed out, rainwater such as acid rain is used. It is difficult to use in architectural applications immersed in a slab, and in hot summer environments or high-temperature environments of environmental testing machines, damage due to the generation of thermal stress is also a problem.

Further, it is described that, instead of the spacers, a sheet glass provided with projections having a constant height is overlapped on the surface with the projections, and the outer periphery is hermetically bonded with an adhesive to form a space. There is no specific description about the arrangement method or the like.

In a low-pressure double-pane glass panel in which the peripheral end is sealed with molten solder glass, it is necessary to heat at a temperature higher than the melting point of the solder at the time of sealing, for example, at 250 ° C. or higher.
In order to further improve the heat insulation performance, for example, when using a low radiation plate glass in which one of the plate glasses is coated with a laminated film of Ag and ZnO by a sputtering method, the special metal film is exposed to a high temperature, and the film is damaged. Or impair the heat insulation performance.

The present invention has been made in view of the above points, and a special metal film formed by a sputtering method having a low vertical emissivity can be adopted as a coating film of a low radiation plate glass. It is an object of the present invention to provide a double-glazed glass panel which can be extremely excellent and can maintain long-term durability.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a double-glazed glass panel of the present invention is provided by separating two glass sheets at a predetermined interval, and maintaining a dot-like or line-like shape. And a peripheral edge portion of the panel is sealed with a sealing material mainly composed of an organic polymer material to form a low-pressure space. For example, 88-7 manufactured by Kanebo NSC Co., Ltd. as hot melt butyl as a base material of a sealing material.
When 500 is used, it is not always necessary to fill the adsorbent, but if it is used as it is, such as M145 made by Yokohama Rubber, a gas or a low molecular weight substance is permeated or released into a low pressure space. In some cases, silica gel, activated carbon,
60 adsorbents such as activated clay, zeolite, oxygen adsorbent
It is preferred to fill at a rate of up to 50% by weight, preferably up to 50% by weight.

The double-layer glass panel of the present invention has a chemical durability mainly as compared with the molten solder glass by using a sealing material mainly composed of an organic polymer material instead of the molten solder glass as the sealing material. It is excellent and does not corrode even when immersed in rainwater such as acid rain or acidic outer wall cleaners and window cleaners, so it can be used for transport applications such as construction and vehicles.

Further, since the sealing material made of an organic polymer material has viscoelastic properties, the thermal stress generated in a hot summer environment or a high temperature environment of an environmental tester is small, and a brittle material generating a large thermal stress is used. Unlike molten solder glass, it is not damaged at the sealing part, so it can be used for architectural uses, transportation uses such as vehicles, and equipment use such as environmental testing machines.

Furthermore, since it has a viscoelastic absorption characteristic of a sealing material mainly composed of an organic polymer material, it can absorb repeated impact loads due to earthquakes, winds, and the like. It can also be used for transportation applications such as.

Further, when the peripheral edge is sealed with a sealing material made of an organic polymer composite material, heating at most to about 150 ° C. suffices, so that one plate has a vertical emissivity. Since a low radiation plate glass coated with a special metal film by a low sputtering method can be used, the heat insulation performance can be further improved.

In addition, a wire spacer is provided around the entire periphery of the panel, so that double sealing is performed in addition to sealing with a sealing material, so that a low pressure state can be maintained for a long time, which is preferable. .

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Two sheets of glass are clear float glass, heat absorbing glass, heat reflecting glass, high-performance heat reflecting glass, wire filled glass, net filled glass, template glass, tempered glass, and double-strength glass. Various types of plate glass such as low reflection plate glass, high transmission plate glass, frosted glass, tapesti (frost) glass, ceramics printed glass, laminated glass can be appropriately combined. At least one of these various plate glasses is coated with a special metal film. It is preferable to use a radiation plate glass because the heat insulation performance is improved. In this case, a coating film formed by a sputtering method having a relatively low vertical emissivity or a coating film formed by a sputtering method having a relatively low vertical emissivity is employed in the present invention. can do.

Further, the low radiation plate glass is JIS
R3106-1985 (Test method for transmittance, reflectance and solar heat gain of sheet glass) Using one or more glasses having a vertical emissivity of 0.20 or less, preferably 0.10 or less, or vertical radiation Two glasses having a ratio of 0.35 or less, preferably 0.25 or less are used.
The thickness of the two sheets of glass is usually 1.9 mm or more. However, in the case of tempered glass, especially in the case of chemically strengthened glass, the thickness is not limited to 1.9 mm.
It is more preferable to use the following.

The material for the point material, wire material or mesh material spacer for maintaining the interval between the two glass sheets is not particularly limited as long as it has a lower hardness than glass and has an appropriate compressive strength. Metals, alloys, steels, ceramics or plastics are preferred. Iron in metal,
Copper, aluminum, tungsten, nickel, chrome,
For alloys such as titanium and steel, carbon steel, chrome steel, nickel steel, stainless steel, nickel chrome steel, manganese steel,
Chrome manganese steel, chromium molybdenum steel, silicon steel, brass, solder, nichrome, duralumin and the like are used. The point material spacers are arranged in, for example, a lattice shape in a spherical shape, a column shape, a prism shape, or the like.

The wire spacer has a cross section of a circle, a semicircle, a square, or the like, and there are linear and curved shapes, and a square spacer, a rhombus, or the like is used as the mesh spacer. In the case where a metal or alloy is coated with ceramics or plastic, the design can be improved by coloring, and the reflection characteristic of the metal can be suppressed.

The spacing between the dot-like, linear or mesh-like spacers is 100 mm or less, preferably 75 mm or less.
The arrangement of these spacers may be regular or irregular as long as it is within the range of the arrangement interval.

The distance between the two glass sheets is 0.05 mm or more and 2.0 mm or less, and 0.1 mm or more and 1.0 mm or more.
The following is preferred. As a sealing material used for the peripheral edge of the panel, a sealing material mainly composed of an organic polymer material is used. The organic polymer material has a moisture permeability (based on a moisture permeability test method for a moisture-proof packaging material specified in JISZ 0208-1976) of 2.0 g / m 2 · 2 as a base material.
4 h (40 ° C., 90% RH) or less, nitrogen permeability (JI
1 × 10 ^-6 cm ³ · cm) (based on plastic film for food packaging specified in SZ 1707-1975)
/ Cm ² · sec · atm (25 ° C) or less and oxygen permeability (based on a plastic film for food packaging specified in JIS Z 1707-1975) is 1 × 10 ^-5 c
polyisobutylene (including reactive polyisobutylene) of m ³ · cm / cm ² · sec · atm (25 ° C) or less
Alternatively, butyl rubber as a main component, a self-adhesive material added with a tackifier or a plasticizer, etc., and calcium carbonate, talc, mica, silica, carbon black, ultrafine silica powder as a filler if necessary. , A composite using ultrafine powder titania or the like, or a base material having a moisture permeability (based on a moisture permeability test method for a moisture-proof packaging material specified in JIS Z 0208-1976).
0 g / m ² · 24 h (40 ° C., 90% RH) or less, and a nitrogen permeability (based on a plastic film for food packaging specified in JIS Z 1707-1975) of 1 × 1
^{0 -6 cm 3 · cm / cm} 2 · sec · atm (25 ℃) or less, the oxygen permeability (based on food packaging plastic film defined in JIS Z 1707-1975)
Is 1 × 10 ^-5 cm ³ · cm / cm ² · sec · atm (2
5 ° C.) Polyisoprene, silicone, polysulfide, polyethylene, polypropylene, Teflon (PTFE) satisfying any or all of the following conditions:
Polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethacrylonitrile, "Lopag" (trade name) manufactured by Monsant, "Barrex" (trade name) manufactured by Sohio, polyethylene terephthalate, nylon 6, nylon 66 Organic polymers such as polyamides, polyvinyl chloride, polyvinyl fluoride, polyimide, etc. to which tackifiers and plasticizers are added as necessary, and calcium carbonate, talc as fillers as necessary Compounds using mica, silica, carbon black, ultrafine silica powder, ultrafine titania and the like can also be used.

When all of the conditions of permeability, nitrogen permeability and oxygen permeability are not satisfied, it is preferable to perform double or triple sealing with a plurality of sealing materials so as to satisfy all conditions.

When a gas or a low molecular weight substance is permeated or released into the low pressure space, silica gel, activated carbon, activated clay, zeolite (3A, 4A, 5A) is applied to the organic polymer material in order to adsorb them. , 13X), an oxygen adsorbent, or an adsorbent such as an alloy getter material such as Ba-Al is preferably filled at 60 wt% or less, preferably 50 wt% or less. In addition, for example, when gas or low molecular weight material is not permeated or released into the low pressure space,
The adsorbent does not have to be filled.

It is preferable that a coating obtained by coating the above-described wire rod spacer with the organic polymer material is disposed at least as a sealing material. Furthermore, a material obtained by coating the above-described wire spacer with a vacuum grease, a vacuum compound, or a vacuum grease or a vacuum compound on the outside of a sealing material made of an organic polymer material is disposed as at least one layer as a secondary sealing material. It is preferable to provide them. Further, the glass end face and the glass peripheral edge outside these sealing materials, a film having a small gas permeability, for example, polyethylene, plastic films such as polyethylene terephthalate, aluminum foil,
It is preferable that a metal foil such as a stainless steel foil and a laminated film obtained by laminating them, or a plastic film on which a metal such as aluminum is vapor-deposited be provided at least as a tertiary sealing material.

The gas exhaust port provided at at least one location on the peripheral edge of the panel mainly uses an organic polymer-based fusion material. The organic polymer-based fusing material is preferably a film of polyethylene resin, polyurethane resin, ethylene vinyl acetate resin, vinylidene chloride, vinylidene fluoride, high-density polyethylene, or the like. Further, a laminated film obtained by laminating a plastic film such as polyethylene terephthalate and a plastic film such as polyethylene terephthalate and a metal foil such as an aluminum foil or a stainless steel foil, or a laminated film obtained by laminating a plastic film obtained by vapor-depositing a metal such as aluminum is preferable. . After the gas exhaust port is subjected to a vacuum degassing process, the gas exhaust port is fused and sealed by a method such as heater heating or high frequency heating.

The degree of vacuum in the sealed low-pressure space between the two glass sheets is 1 × 10 ⁻³ Torr or less, preferably 1 × 1 ⁻³ Torr.
0 ^-3 Torr or less. The double-glazed glass panel of the present invention is, for example, after fixing a spacer on the surface of one of the glass sheets, a sealing material on the periphery, and a gas exhaust port at one location on the periphery.
Put another glass sheet on it. Thereafter, the pressure is reduced in a low-pressure container, the gas exhaust port is fusion-sealed, and then the low-pressure container is leaked and atmospheric pressure is applied thereto to produce a low-pressure double glass.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. 1 and 4 are a sectional view and a plan view, respectively, showing a main part of a low-pressure double-glazed glass panel in Example 1, and FIGS.
1 is a cross-sectional view of a main part showing a low-pressure double-glazed glass panel in Example 2 and Example 3, respectively.

Embodiment 1 The low-pressure double-glazed glass panel 1 of this embodiment is configured as shown in a sectional view of a main part in FIG. 1 and a plan view in FIG.

The two glass sheets 2 and 3 are float glass sheets having a thickness of 3 mm. One of the glass sheets 2 is a low-emission glass sheet in which a low-pressure space 4 is coated with a plurality of films such as Ag and ZnO. Is 0.07.

The spacer 5 is a columnar stainless steel spacer having a height of 0.2 mm and a diameter of 0.5 mm, which is arranged in a grid at intervals of about 20 mm. The sealing material 6 is obtained by filling 20 wt% of zeolite 4A into hot melt butyl containing polyisobutylene as a main component.

The degree of vacuum in the low-pressure space 4 is 7.6 × 10 ⁻³ To.
rr. The procedure for producing the low-pressure double glazing is as follows. First, with the plate glass 3 placed on a table (not shown), the columnar stainless steel spacer 5 is placed for about 20 m.
The sealing material 6 in which a spacer 5 'is buried is disposed around the plate glass 3 except for an exhaust port, and the exhaust port is made of polyethylene film and aluminum foil. Are filled with a sealing material 6 sandwiched with a space between them, and the entire periphery is sealed without any gap.

Next, the plate glass 2 coated with the metal film is placed at a predetermined position, and the upper and lower plate glasses are temporarily bonded. The temporarily bonded double-glazed glass thus obtained is put into a vacuum chamber (not shown), and when the degree of vacuum is increased, the air in the space 4 is exhausted from the exhaust port formed by the two heat-sealing films, The degree of vacuum in the space 4 gradually increases.

The space 4 has a predetermined pressure, for example, 7.6 × 10 ^-3.
When the pressure reaches Torr, a heated bar or the like is brought into contact with the heat-sealing film protruding out of the plate glass and pressed to be fused.

Thereafter, when a gas such as air is introduced into the vacuum chamber and the pressure is raised to near the atmospheric pressure, the pressure difference between the low-pressure space 4 and the outside and the heating of the peripheral portion (about 1).
(00 ° C.), it is possible to obtain a low-pressure double glazing in which the sealing portion is more firmly adhered.

The initial dew point of the low-pressure double-glazed glass thus obtained is determined by the method specified in JIS R3209-1995.
The initial dew point was −70 ° C. or less when measured by a method according to 89. Initial heat transmission coefficient is 1.36 kcal / m ² h
° C, and after the accelerated durability test class III specified in JIS R3209-1995, the dew point is -55 ° C, the heat transmission coefficient is 1.46 kcal / m ² h ° C, and the heat insulation performance is high and severe. Even after the test under the conditions, it was confirmed that there was almost no decrease in the initial dew point and the heat transmission coefficient, and that the sample had sufficient durability. In addition, as is clear from the measurement results of the heat insulation performance, it was also confirmed that the film coated on the plate glass 2 was not affected at all by the temperature at the time of sealing.

Embodiment 2 The low-pressure double-glazed glass panel 1 of this embodiment is configured as shown in a sectional view of a main part of FIG.

The two glass sheets 2 and 3 are float glass sheets having a thickness of 3 mm. One glass sheet 2 is a low-emission glass sheet in which a low-pressure space 4 is coated with a special metal film by a sputtering method, and has a vertical emissivity of 0.3. 07.

The spacer 5 is a columnar stainless steel spacer having a height of 0.2 mm and a diameter of 0.5 mm, which is approximately 20 mm.
They were arranged in a grid at mm intervals. The sealing material 6 is made of hot melt butyl mainly composed of polyisobutylene and zeolite 5
A was filled at 30 wt%. Furthermore, sealing material 6
Vacuum grease was used as the secondary sealing material 8 on the outside of the device.

The degree of vacuum in the low-pressure space 4 is 7.6 × 10 ⁻³ To.
rr was prepared by the same method as in Example 1. When the dew point and the heat transmission coefficient of the low-pressure double glazing 1 thus obtained were measured by the method described in Example 1, the initial dew point was −70 ° C. or less. Initial heat transmission coefficient is 1.32 kcal /
m ² h ° C, and the dew point was −60 ° C. after JIS accelerated durability test III. The heat transmission coefficient is 1.41 kcal / m ² h ° C
Thus, the dew point is lower than in Example 1, and the heat insulation performance is improved.

Embodiment 3 The low-pressure double-glazed glass panel 1 of this embodiment is configured as shown in a sectional view of a main part in FIG.

The two glass sheets 2, 3 are float glass sheets having a thickness of 3 mm. One of the glass sheets 2 is a low-emission glass sheet in which the low-pressure space 4 is coated with a special metal film, and the vertical emissivity is 0.07. . The spacer 5 has a height of 0.
Cylindrical spacers made of stainless steel having a diameter of 2 mm and a diameter of 0.5 mm were arranged in a grid at intervals of about 20 mm.

The sealing material 6 is a single body of hot melt butyl containing polyisobutylene as a main component, and a stainless linear spacer 5 ′ having a diameter of 0.2 mm is embedded in the sealing material 6. Further, a secondary sealing material 8 is provided outside the sealing material 6.
Vacuum grease was used. The low-pressure space 4 was manufactured in the same manner as in Example 1 by setting the degree of vacuum to 7.6 × 10 ⁻⁴ Torr.

The low pressure double glazing 1 thus obtained
When the dew point and the heat transmission coefficient were measured by the method described in Example 1, the initial dew point was -70 ° C or less, the initial heat transmission coefficient was 0.46 kcal / m ² h ° C, and the JIS accelerated durability test III Later dew point is -65 ° C, heat transmission coefficient is 0.69 kc
al / m ² h ° C., the dew point was further reduced and the heat insulation performance was further improved as compared with Example 2.

Embodiment 4 The low-pressure double-glazed glass panel 1 of this embodiment is provided with a tertiary unillustrated wrapper around the peripheral edge of the panel further outside the secondary sealing material 8 shown in Embodiment 3 (FIG. 3). The structure was the same as in Example 3 except that a polyethylene terephthalate film was adhered as a sealing material.

The degree of vacuum in the low pressure space is 7.6 × 10 ^-4 Torr.
r. The low-pressure double-glazed glass panel thus obtained has an initial dew point of -70 ° C or less and an initial heat transmission coefficient of 0.42.
kcal / m ² h ° C, JIS accelerated durability test III
After that, the dew point is -70 ° C or less, and the heat transmission coefficient is 0.43 kca.
1 / m ² h ° C., and the result was much higher than the performance of the panel of Example 3.

COMPARATIVE EXAMPLE 1 In a comparative example of the low-pressure double-glazed glass panel 1, one of the low-radiation glass sheets was coated with a special metal film by a CVD method (vertical emissivity was 0.22) and sealed. The configuration is the same as that of Example 1 except that the peripheral portion is sealed with a low melting point glass having a melting point of about 300 ° C. as a material and an exhaust port.

The degree of vacuum in the low pressure space is 7.6 × 10 ^-4 Torr.
r. The low pressure double glazing panel thus obtained has an initial dew point of -70 ° C or less and an initial heat transmission coefficient of 1.31.
kcal / m ² h ° C, and the performance is not so inferior to each of the examples, but the JIS accelerated durability test II
The dew point after class I is -10 ° C, and the heat transmission coefficient is 4.76 kcal.
/ M ² h ° C, the dew point and the heat insulation performance are both reduced.
It can be seen that the durability is poor.

Comparative Example 2 The structure was the same as that of Example 4 except that the degree of vacuum in the low-pressure space was 7.6 Torr.

The low pressure double-glazed glass panel thus obtained has an initial dew point of -70 ° C. or less and an initial heat transmission coefficient of 4.7.
3 kcal / m ² h ° C, JIS accelerated durability test I
After class II, the dew point is -70 ° C or less, and the heat transmission coefficient is 4.74 kc
al / m ² h ° C., indicating that the heat insulation performance has been lowered from the initial stage.

Table 1 summarizes the above examples and comparative examples.

[0056]

[Table 1]

[0057]

As described in detail above, according to the present invention,
The heat insulation performance can be significantly improved and long-term durability can be maintained.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a main part of a low-pressure double-glazed glass panel according to Embodiment 1 of the present invention.

FIG. 2 is a side sectional view showing a main part of a low-pressure double-glazed glass panel according to a second embodiment of the present invention.

FIG. 3 is a side sectional view showing a main part of a low-pressure double-glazed glass panel according to a third embodiment of the present invention.

FIG. 4 is a plan view showing the low-pressure double-glazed glass panel in Embodiment 1 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low-pressure multi-layer glass panel 2 Flat glass (low radiation glass) 3 Flat glass 4 Low-pressure space 5, 5 'spacer 6 Sealing material 7, 7' Heat sealing film 8 Secondary sealing material

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Masahiro Hiragawa 1510 Oguchicho, Matsusaka-shi, Mie Central Glass Co., Ltd.

Claims (3)

[Claims] 1. A sheet glass is spaced at a predetermined interval, and a dot-like, linear or net-like spacer for maintaining this interval is disposed, and the peripheral edge of the two sheet glasses is mainly composed of an organic polymer. A low-pressure double glazing panel characterized in that a low-pressure space is formed between two sheet glasses by sealing with a sealing material made of a base material. 2. The low pressure double glazing panel according to claim 1, wherein the sealing material mainly composed of an organic polymer material is filled with an adsorbent. 3. The low pressure double glazing panel according to claim 1, wherein a linear spacer is buried in a sealing portion at a peripheral edge of the panel.