JP7666103B2 - Sealing material and insulating glass using the same - Google Patents

Description

The present invention relates to a sealing material and insulating glass using the same.

Conventionally, there has been known a double-glazing unit in which two or more glass sheets are arranged facing each other and spaced apart only by a spacer to form a hollow layer between them, the spacer being made of a thermoplastic resin composition having a JIS A hardness of 10 to 90 at 25°C, the thermoplastic resin composition containing butyl-based rubber, crystalline polyolefin, a desiccant, and an inorganic filler, the proportion of the butyl-based rubber relative to the total amount of the butyl-based rubber and the crystalline polyolefin being 50 to 98% by weight, the proportion of the crystalline polyolefin being 2 to 50% by weight, and the proportion of the inorganic filler relative to 100 parts by weight of the total of the butyl-based rubber and the crystalline polyolefin being 200 parts by weight or less (see, for example, Patent Document 1).

Figure 4 of Patent Document 1 discloses a double-glazed glass in which a primary sealant 3 is interposed between glass plates 1a, 1b and a metal spacer 2 to isolate the hollow layer from the outside air, and the gap (recess) formed by the inner surface of the periphery of the opposing glass plates and the outer peripheral surface of the spacer is sealed with a secondary sealant that cures at room temperature, typically a polysulfide-based or silicone-based sealant. Figure 5 of Patent Document 1 discloses a double-glazed glass in which a resin mixed with a desiccant is used as the spacer 4 and sealed with a secondary sealant that cures at room temperature.

Japanese Patent Application Publication No. 10-114551

Various standards have been established to ensure the quality of insulating glass, but when used as fire-resistant insulating glass, it is required to pass a fire resistance test based on ISO834-1:1999 as a standard for durability in the event of a fire.

This fire resistance test is carried out by directing a flame from a burner at the front of the insulating glass for a specified time, and requires that the flame does not penetrate the insulating glass and that the insulating glass withstands the specified time without collapsing. Here, whether or not the insulating glass collapses depends heavily on the fire resistance of the sealant (hereinafter also referred to as the "secondary sealant") that seals the periphery of the insulating glass.

Therefore, the present invention aims to provide a sealing material for insulating glass that has excellent fire resistance and insulating glass that uses the same.

In order to achieve the above object, a sealing material according to one aspect of the present invention is a sealing material for sealing a peripheral portion of a double-glazing unit having two or more glass plates arranged opposite each other and spaced apart via a spacer so as to form a hollow layer therebetween, the sealing material comprising:
The sealing material has a butyl-based rubber and an inorganic filler, the proportion of the butyl-based rubber relative to the total amount of the butyl-based rubber and the crystalline polyolefin is 98% by mass or more and 100% by mass or less, and the proportion of the crystalline polyolefin is 0% by mass or more and less than 2% by mass (including the case where the crystalline polyolefin is not included),
The proportion of the inorganic filler per 100 parts by mass of the total of the butyl-based rubber and the crystalline polyolefin is 100 parts by mass or more and 250 parts by mass or less.

The present invention provides a sealing material for insulating glass that has high fire resistance, and insulating glass that uses the same.

1 is a diagram showing a secondary sealing material and insulating glass according to a first embodiment of the present invention. FIG. 1 is a diagram showing an example of a double-glazing unit according to a first embodiment of the present invention, which is constructed using fire-retardant glass and Low-E glass. FIG. 1 is a diagram for explaining a fire resistance test method based on ISO 834-1:1999. FIG. 4 is a front view of the furnace 200 shown in FIG. 3. FIG. 1 is a diagram showing a heating curve according to ISO 834-1:1999. FIG. 1 shows an arrangement of insulating glass in which a Low-E glass 11a is arranged on the heated side and a fire-resistant glass 10a is arranged on the non-heated side. This is a diagram showing the arrangement of insulating glass 100 in which the Low-E glass 11a is arranged on the non-heated side and the fire-resistant glass 10a is arranged on the heated side. 13A and 13B are diagrams showing a secondary sealing material according to a second embodiment and insulating glass to which the secondary sealing material is applied.

Below, we will explain the form for implementing the present invention with reference to the drawings.

[First embodiment]
Fig. 1 is a diagram showing a secondary sealant and insulating glass according to a first embodiment of the present invention. In Fig. 1, the insulating glass 100 includes a first glass 10, a second glass 11, a spacer 20, a desiccant 30, a hollow layer 40, a primary sealant 50, and a secondary sealant 60.

As shown in FIG. 1, the insulating glass 100 has a first glass 10 and a second glass 11 arranged opposite each other, and a spacer 20 is used to define the distance between the opposing first glass 10 and second glass 11 to form a hollow layer 40. A primary sealant 50 is provided between the first glass 10 and the spacer 20, and between the second glass 11 and the spacer 20. Note that the primary sealant 50 is drawn thick for ease of understanding, but in reality it is extremely thin, and is set to a thickness that can be ignored compared to the overall thickness of the insulating glass, for example, a thickness within the range of about 0.1 to 0.8 mm, and may be set to a thickness of about 0.3 mm, for example.

If necessary, an adhesive may be used between the primary sealant 50 and the first glass 10 and the second glass 11 to form an adhesive layer.

The secondary sealant 60 is provided on the periphery of the insulating glass 100 so as to cover the outer periphery of the spacer 20 and the primary sealant 50. The secondary sealant 60 is provided so as to fill the space on the periphery between the first glass 10 and the second glass 11, and serves to seal the hollow layer 40. The desiccant 30 is provided to absorb moisture in the hollow layer 40 and keep it dry.

In this technical field, the sealant provided on the periphery of the insulating glass 100 so as to surround the outer peripheral surface of the spacer 20 is generally referred to as the "secondary sealant". That is, regardless of the presence or absence of the primary sealant, the sealant provided in a position surrounding the outer peripheral surface of the spacer 20 is often referred to as the secondary sealant. Therefore, in this embodiment, regardless of the presence or absence of the primary sealant, the sealant provided to cover the outer peripheral surface (side surface) of the spacer 20 is referred to as the secondary sealant. In addition, when simply referring to the "sealant", both the primary sealant and the secondary sealant are included, but the primary sealant is provided between the spacer 20 and the first glass 10 and between the spacer 20 and the second glass 11, so it can be distinguished by its position.

In FIG. 2, fire-resistant glass 10a is used as one embodiment of the first glass 10, and Low-E glass 11a is used as the second glass 11, so that the insulating glass 100 is configured as fire-resistant insulating glass.

The Low-E glass 11a is a glass plate coated with a low-radiative Low-E metal film 16 on the surface facing the hollow layer 40.

Fire-resistant glass 10a refers to glass sheets that have a flame-resistant performance of 20 minutes or more as measured by a test method that conforms to the flame-resistant and semi-flame-resistant performance test evaluation method in the "Fireproof Performance Testing and Evaluation Manual (issued by the Building Materials Testing Center, established on June 1, 2000, last revised on July 13, 2020)." Examples of fire-resistant glass 10a include wired glass, heat-resistant plate glass, and chemically strengthened glass.

Here, wired glass refers to wired plate glass as defined in JIS R3204 (wired plate glass and lined plate glass). Wired glass has a metal mesh inside the glass plate, which increases the strength of the glass. The mesh is, for example, arranged in a lattice pattern inside the wired glass.

Heat-resistant plate glass refers to plate glass that meets the "Heat-resistant Plate Glass Quality Standards" established by the Curtain Wall and Fire-Resistant Openings Association. There are three types of heat-resistant plate glass: low-expansion fireproof glass, heat-resistant tempered glass, and heat-resistant crystallized glass.

Chemically strengthened glass is glass whose strength has been increased by forming a compressive stress layer on the surface of the glass using a chemical strengthening method. Chemically strengthened glass is produced using a strengthening technique in which a glass plate, such as soda lime silicate glass containing Na and Li components, is immersed in a molten salt such as potassium nitrate, and the Na ions and/or Li ions, which have a small atomic diameter and are present on the surface of the glass plate, are replaced with K ions, which have a large atomic diameter and are present in the molten salt, thereby forming a compressive stress layer on the surface layer of the glass plate and increasing its strength.

Compared to wired glass, chemically strengthened glass has superior visibility and design, and has a lower risk of thermal cracking. Also, compared to heat-resistant tempered glass, chemically strengthened glass has a lower risk of spontaneous breakage, and can ensure strength and fire resistance even when made into a thin sheet. Furthermore, chemically strengthened glass can suppress warping more than heat-resistant tempered glass, so gaps in the sealing material are less likely to open when made into double-insulated glass, and flames are less likely to leak from the edges of the double-insulated glass in the event of a fire, improving fire resistance.

At least one of the main surfaces on which the compressive stress layer of the chemically strengthened glass is formed, the surface compressive stress value is preferably 300 MPa or more and 1000 MPa or less. If the surface compressive stress value is 300 MPa or more, the mechanical strength of the chemically strengthened glass is high. If the surface compressive stress value is 1000 MPa or less, the manufacturing cost can be reduced and the depth of the compressive stress layer can be ensured.

At least one of the main surfaces on which the compressive stress layer of the chemically strengthened glass is formed, the thickness of the compressive stress layer in the plate thickness direction is preferably 20 μm or more and 50 μm or less. If the thickness of the compressive stress layer is 20 μm or more, sufficient strength against external forces can be obtained. If the thickness of the compressive stress layer in the plate thickness direction is 50 μm or less, immersion in the molten salt can be performed for a short period of time, and chemically strengthened glass can be easily obtained.

The thickness of the first glass 10 may be, for example, 3 mm to 11 mm, 6.8 mm, or 10 mm. The thickness of the second glass 11 may be, for example, 2.5 mm to 19 mm, 3 mm to 10 mm, or 5.0 mm. However, the thicknesses of the first glass 10 and the second glass 11 can be various thicknesses depending on the use of the insulating glass 12.

The secondary sealant 60 according to this embodiment has excellent fireproofing properties and can therefore be suitably used in fireproof insulating glass that combines fireproof glass 10a and Low-E glass 11a, but can also be used in insulating glass that has normal glass plates facing each other. Therefore, the secondary sealant 60 and the insulating glass 100 that uses it are not limited to fireproof insulating glass, but can also be used in normal insulating glass.

First, before describing the secondary sealing material 60 according to this embodiment and the insulating glass 100 using the same, we will explain the fire test. The fire test is a test that targets fire resistance tests based on ISO 834-1:1999, and passing this test is an indicator of the fire resistance of the insulating glass.

Figure 3 is a diagram for explaining the method of fire resistance testing based on ISO834-1:1999. As shown in Figure 3, a burner 210 and a thermometer 220 are provided in a furnace 200, and the double-glazed glass 100 to be tested is attached to the opening 201 of the furnace 200. Figure 4 is a front view of the furnace 200 shown in Figure 3. For flame-blocking performance, in the state shown in Figures 3 and 4, the double-glazed glass 100 is heated for 20 minutes according to the heating curve (T = 345 log10 (8t + 1) + 20, T: furnace temperature (°C), t: time (min)) conforming to ISO834.

Figure 5 shows a heating curve in accordance with ISO 834-1:1999. The inside of the furnace 200 is heated by the burner 210 so that the temperature inside the furnace measured by the thermometer 220 has the temperature gradient shown in Figure 5, and a fire resistance test of the insulating glass 100 is performed.

The fire resistance test is passed if the double-glazed glass 100 can withstand 20 minutes without flames penetrating the double-glazed glass 100 and without flaming on the non-heated side for 10 consecutive seconds. More precisely, the test is passed if all of the following conditions are met: there is no flame ejection on the non-heated side for more than 10 seconds, there is no flame on the non-heated side for more than 10 seconds, and there is no damage or gaps such as cracks through which the flames can pass. For example, if the two panes 10 and 11 of the double-glazed glass 100 collapse, the flames will penetrate the double-glazed glass 100, and if the secondary sealant 60 and spacer 20 burn and cracks or gaps through which the flames can pass are created, flames will break out from the four sides of the double-glazed glass 100. Therefore, the fire resistance of the secondary sealant 60 is the key to passing the fire resistance test. The fire resistance test is performed on both the front and back sides of the double-glazed glass 100.

Figure 6 shows the arrangement of the double-glazing 100 in which the Low-E glass 11a of the double-glazing 100 is arranged on the heated side and the fire-resistant glass 10a is arranged on the non-heated side. In this case, since the fire-resistant glass 10a is on the non-heated side, even if the Low-E glass 11a collapses, the fire-resistant glass 10a on the non-heated side will often survive and pass.

Figure 7 shows the arrangement of the double-glazed glass 100 in which the Low-E glass 11a of the double-glazed glass 100 is arranged on the non-heated side and the fire-resistant glass 10a is arranged on the heated side. In this case, the Low-E metal film 16 of the Low-E glass 11a reflects heat to the inside of the furnace 200, so the heating pace of the fire-resistant glass 10a is faster than in the case of Figure 6. If the inside of the secondary sealant 60 and the spacer 20 burns and the fire-resistant glass 10a collapses, the Low-E glass 11a is not as fire-resistant as the fire-resistant glass 10a, so the flames often penetrate. In other words, the arrangement pattern of Figure 7 is likely to fail due to its configuration. In order to pass the fire test with the arrangement of Figure 7, it is required to increase the heat resistance of the secondary sealant 60 and prevent the fire-resistant glass 10a from collapsing as much as possible.

When a metal spacer, for example an aluminum spacer, is used as the spacer 20, even if the secondary sealant 60 burns, the spacer 20 can often prevent collapse. On the other hand, when the spacer 20 is made of resin or polyvinyl chloride, the spacer 20 cannot withstand the combustion of the secondary sealant 60, and the Low-E glass 11a often collapses.

Therefore, if the fire resistance of the secondary sealant 60 is improved, the fire resistance test can be passed regardless of the material of the spacer 20.

The secondary sealing material 60 that can pass the fire resistance test based on ISO834-1:1999 and the insulating glass 100 that uses the same will be described in detail below, again with reference to FIG. 1.

In FIG. 1, first, the spacer 20 can be either an aluminum spacer or a resin spacer.

Traditionally, double-glazed glass has used aluminum spacers, but in recent years, there has been a growing need to improve the insulation around the glass, and there is a growing need for resin spacers made of polyvinyl chloride and other materials that have better insulation properties than aluminum spacers, and spacers that contain desiccants. (We will discuss dry-type spacers later.)

As mentioned above, when using resin spacers or resin spacers with desiccant kneaded into them, the problem is that fire resistance is reduced.

In other words, because aluminum itself is a non-combustible material, the aluminum spacer is able to maintain its shape even after the fire resistance test.

On the other hand, resin spacers use hard resin materials such as PVC, which means that they melt, decompose, and burn during fire resistance tests, making it difficult to maintain their shape. Similarly, resin-incorporated spacers also have a resin matrix, which means that they melt, decompose, and burn during fire resistance tests, making it difficult to maintain their shape.

Generally, silicone-based sealants, polysulfide-based sealants, and hot-melt butyl-based sealants are used as secondary sealing materials.

Silicone-based sealants have high heat resistance, but do not provide a high gas barrier, raising concerns about the lifespan of insulating glass. Polysulfide-based sealants have high gas barrier properties, but insufficient fire resistance and generate acidic gases when burned. Hot-melt butyl-based sealants have very high gas barrier properties, but insufficient fire resistance.

The secondary sealant 60 according to this embodiment is a hot-melt butyl-based sealant, but it is a sealant with significantly improved fire resistance. The secondary sealant 60 according to this embodiment ensures fire resistance even when the spacer 20 is a resin spacer or a spacer containing a desiccant, and constitutes a sealant with high durability for the insulating glass 100. The details of this will be explained below.

The secondary sealing material 60 according to this embodiment contains butyl-based rubber, crystalline polyolefin, and inorganic filler, and the proportion of the butyl-based rubber relative to the total amount of the butyl-based rubber and the crystalline polyolefin is 98% by mass or more and 100% by mass or less, the proportion of the crystalline polyolefin is 0% by mass or more and less than 2% by mass (including cases where no crystalline polyolefin is included), and the proportion of the inorganic filler relative to 100 parts by mass of the total amount of the butyl-based rubber and the crystalline polyolefin is 100 parts by mass or more and 250 parts by mass or less.

The butyl rubbers mentioned above include butyl rubber, halogenated butyl rubber, polyisobutylene, and partially vulcanized butyl. These are hot-melt butyl rubbers that can be molded by hot melt molding. Compared to silicone, they have the advantage of having high moisture-proofing properties and a long life under normal use. There are also sealing materials made of polysulfide, but they contain sulfur components and may emit toxic gases when burned, so they are not suitable.

However, butyl rubber is fundamentally flammable, making it difficult for it to pass fire resistance tests as is. However, in this embodiment, the above-mentioned compounding has significantly improved fire resistance.

It is preferable that the butyl rubber is not cross-linked, because this improves the fluidity of the secondary sealant.

The ratio of the butyl-based rubber to the total amount of the butyl-based rubber and the crystalline polyolefin is 98% by mass or more, preferably 99% by mass or more, more preferably 99.5% by mass or more, and particularly preferably 100% by mass. The ratio of the butyl-based rubber to the total amount of the butyl-based rubber and the crystalline polyolefin is 100% by mass or less, and may be 99.9% by mass or less, 99.8% by mass or less, or 99.5% by mass or less.

The secondary sealant 60 according to this embodiment contains polyisobutylene as a butyl-based rubber, and the proportion of polyisobutylene is preferably 5% by mass or more and 20% by mass or less. If the proportion of polyisobutylene is 5% by mass or more, the adhesion between the secondary sealant 60 and the first glass 10 and the second glass 11 is good. The proportion of polyisobutylene is more preferably 5% by mass or more, and particularly preferably 8% by mass or more. Furthermore, if the proportion of polyisobutylene is 20% by mass or less, the secondary sealant 60 is less likely to flow and has good shape retention. The proportion of polyisobutylene is more preferably 15% by mass or less, and particularly preferably 12% by mass or less.

The secondary sealing material 60 according to this embodiment may contain crystalline polyolefin together with the butyl-based rubber. Crystalline polyolefin refers to a homopolymer of an olefin such as ethylene or propylene, a copolymer with other monomers, or a modified product thereof, which has crystallinity. The polymer structure is preferably a syndiotactic structure or an isotactic structure, but may contain other structures. Ethylene and propylene are particularly preferred as olefins.

Copolymers include copolymers of two or more olefins and copolymers of olefins and other monomers, and copolymers of ethylene or propylene and other monomers that do not inhibit crystallinity are suitable. Furthermore, block copolymers are more suitable than alternating or random copolymers. Modified products include crystalline polyolefins into which functional groups such as acid anhydride groups, carboxyl groups, and epoxy groups have been introduced.

Crystalline polyolefins are effective in maintaining the shape of the insulating glass 100, so they contribute to improving the performance of the insulating glass 100 rather than improving its fire resistance.

In the above resin composition, the ratio of crystalline polyolefin to the total amount of butyl rubber and crystalline polyolefin is 0% by mass or more and less than 2% by mass. That is, crystalline polyolefin is not essential and may be contained as a component as necessary. The ratio of crystalline polyolefin to the total amount of butyl rubber and crystalline polyolefin is preferably 1% by mass or less, more preferably 0.5% by mass or less, and particularly preferably does not contain crystalline polyolefin. In addition, when crystalline polyolefin is contained, the ratio of crystalline polyolefin to the total amount of butyl rubber and crystalline polyolefin may be 0.1% by mass or more, 0.2% by mass or more, or 0.5% by mass or more.

The secondary sealant 60 according to the present embodiment includes an inorganic filler. The ratio of the inorganic filler to 100 parts by mass of the butyl rubber and the crystalline polyolefin is 100 parts by mass or more, preferably 150 parts by mass or more, and more preferably 180 parts by mass or more. The ratio of the inorganic filler to 100 parts by mass of the butyl rubber and the crystalline polyolefin is 250 parts by mass or less, may be 230 parts by mass or less, or may be 220 parts by mass or less. The inorganic filler contains many components that leave residues even when burned, and therefore contributes to improving the fire resistance of the secondary sealant 60. Examples of inorganic fillers include talc, calcium carbonate, silica, magnesium hydroxide, carbon black, expanded black smoke, and adsorbents.

Talc, calcium carbonate and silica powder are used as fillers and contribute to maintaining the shape after combustion. These are non-combustible materials and help maintain the shape even after combustion, so it is preferable to mix them in a certain ratio. It is preferable to use talc or calcium carbonate rather than silica powder.

The particle size of the talc is, for example, preferably 3 μm or more and 10 μm or less in terms of the median diameter d50, more preferably 4 μm or more and 8 μm or less, and even more preferably 4 μm or more and 6 μm or less.

Magnesium hydroxide and hydrated silica function as flame retardants, releasing moisture during combustion and suppressing combustion. In other words, they have the effect of cooling the combustion with water, which helps improve fire resistance.

Among carbon blacks, furnace-type carbon black has an adsorption effect equivalent to that of activated carbon, and adsorbs oxygen and combustion gases, delaying combustion. This improves the fireproofing performance of the secondary sealant 60. Carbon black has a very large nitrogen specific surface area, and has a significant trapping effect on combustion gases such as methane and carbon monoxide.

Among carbon blacks, hard carbon type carbon blacks have a relatively large surface area and are therefore preferred for fire protection applications while increasing the strength of rubber. The nitrogen specific surface area of carbon black is preferably 50 m ² /g or more and 200 m ² /g or less, more preferably 55 m ² /g or more and 150 m ² /g or less, and even more preferably 60 m ² /g or more and 120 m ² /g or less. The hard carbon type carbon black is more preferably HAF type.

Expandable graphite expands during combustion and helps maintain the shape of the insulating glass. In other words, it expands during combustion and plays a role in covering the burned portion of the secondary sealing material 60.

The adsorbent has the effect of adsorbing flammable gases and retarding combustion. Incidentally, flammable gases include, for example, methane and carbon monoxide. By adsorbing these flammable gases, it is possible to suppress combustion. Examples of the adsorbent include zeolite powder and silica gel. Incidentally, it is preferable to use zeolite in powder form.

In addition, it is preferable to use a thermal decomposition accelerator as an additive. Examples of thermal decomposition accelerators include organic sulfur compounds, more specifically, thioethers. Thioethers are materials that accelerate thermal decomposition at 200-350°C, and they play a role in accelerating thermal decomposition at low temperatures and reducing combustion components at high temperatures.

It is not necessary to contain all of these inorganic filler components, but it is sufficient to contain at least one or more components. However, in order to improve fire retardant performance, it is preferable to contain at least two of the above-mentioned inorganic filler components, more preferably to contain at least three, and even more preferably to contain at least four.

It is not necessary to use an adhesive, but if one is used, for example, a urethane adhesive made from polyolefin polyol, non-yellowing isocyanate, and a derivative of non-yellowing isocyanate may be used. These adhesives are non-melting cross-linking adhesives, so they have the property of remaining in place without melting even when heated, and can improve the fire resistance of the insulating glass 100.

The JIS A hardness of the secondary sealant at 25°C is preferably 50 or more and 90 or less. This is a performance required for normal insulating glass 100, rather than fireproofing performance, and in order to maintain the shape of the insulating glass 100, a hardness of 50 or more is preferable. In addition, in order to prevent cracking of the panes 10 and 11 of the insulating glass 100, a hardness of 90 or less is preferable. Furthermore, the JIS A hardness of the secondary sealant 60 at 25°C is preferably 55 to 90.

According to the first embodiment, while a butyl-based sealant is used as the base material, an inorganic filler that improves fire resistance is added, thereby improving fire resistance, and a secondary sealant 60 and insulating glass 100 that can pass the fire resistance test based on ISO834-1:1999 can be constructed.

Specifically, if the mass of the secondary sealant at room temperature is A, and the mass when the secondary sealant is heated from room temperature in an air atmosphere at a rate of 10°C/min to 500°C is B, the mass ratio B/A can be set to 40% or more. The ratio of mass B to mass A can be considered as the residual rate of the secondary sealant 60 at 500°C when the secondary sealant 60 is heated at a rate of 10°C/min and gradually melts and loses its shape. With the secondary sealant 60 according to this embodiment, such a residual rate can be set to 40% or more, and fire resistance can be improved.

Second Embodiment
FIG. 8 is a diagram showing a secondary sealing material and insulating glass according to the second embodiment.

The insulating glass 101 in the second embodiment differs from the insulating glass 100 in the first embodiment in that it has a desiccant-containing spacer 21 instead of the spacer 20. Otherwise, it is the same as the insulating glass 100 in the first embodiment, and the first glass 10 and the second glass 11 have the same configuration as in the first embodiment, so they are given the same reference numerals. In addition, the secondary sealant 61 is similar in material to the second sealant 60 in the first embodiment, but only the shape is different because the shape of the resin spacer 21 is different from that of the spacer 20.

The desiccant-containing spacer 21 is a type of spacer that is widely used these days, and has a structure in which a desiccant 30 is mixed into the spacer. Since the desiccant-containing spacer is also constructed as a resin spacer, it has lower fire resistance than metal spacers.

For such desiccant-containing spacers 21, the secondary sealant 60 according to this embodiment can be applied, fire-resistant glass 10a can be used as the first glass 10, Low-E glass 11a can be used as the second glass 11, and the insulating glass 100 can be made into a fire-resistant insulating glass, thereby forming an insulating glass 101 that can pass the fire resistance test based on ISO834-1:1999.

In this way, the secondary sealing material 60 according to this embodiment can be applied to various spacers 20, 21 and insulating glass 100, 101.

[Example]
Hereinafter, an example will be described in which a double glazing 100 was constructed using the secondary sealing material 60 according to the first embodiment, and a fire resistance test based on ISO834-1:1999 was carried out.

In addition, for ease of understanding, the components described below will use the same reference symbols as those used in the first embodiment.

In this embodiment, the first glass 10 is made of wire-reinforced glass having a thickness of 6.8 mm, the second glass 11 is made of Low-E glass having a thickness of 5 mm, and the thickness of the hollow layer 40 is 12 mm. The width of the first glass 10 and the second glass 11 is 900 mm, and the height is 2000 mm.

The spacer 20 is made of a non-metallic material, TGI (registered trademark)-Spacer M (manufactured by TECHNOFORM), which is a mixture of plastic and stainless steel. The height of the spacer 20 is 6.85 mm.

The primary sealant 50 was made of SM-488, a thermoplastic polyisobutylene-based sealing material manufactured by Yokohama Rubber Co., Ltd. The thickness of the primary sealant 50 was 0.3 mm on each side.

As shown in Table 1, the secondary sealant 60 is made by varying the ratio of butyl rubber, crystalline polyolefin, and inorganic filler, and further varying the components of the inorganic filler.

Butyl 365 manufactured by JSR was used as the butyl rubber. Oppanol B15 manufactured by BASF was used as the polyisoprene. LJ902 manufactured by Nippon Polyethylene was used as the polyethylene. FH104A manufactured by Fuji Talc was used as the talc. Whiten SB Red manufactured by Shiraishi Calcium was used as the calcium carbonate. Magseeds N manufactured by Konoshima Chemical Co., Ltd. was used as the magnesium hydroxide. Seast 3 manufactured by Tokai Carbon Co., Ltd. was used as the carbon black. 955025L manufactured by Ito Graphite Industries Co., Ltd. was used as the expanded graphite. Molecular Sieve 4A powder manufactured by Union Showa Co., Ltd. was used as the adsorbent. TRez HA125 manufactured by JXTG was used as the tackifier.

The insulating glass 100 was constructed under these conditions and subjected to a fire resistance test based on ISO834-1:1999. The fire resistance test was performed in the same manner as described in Figures 3 to 7.

The results of the examples and comparative examples are shown in Table 1.

表１に示されるように、実施例１～５のうち、実施例１～４は結晶性ポレオレフィンを含まず、ブチル系ゴム、無機フィラー及び添加剤のみを含む組成となっている。実施例５は、結晶性ポレオレフィンを０．５質量％含んでいる。

As shown in Table 1, among Examples 1 to 5, Examples 1 to 4 do not contain crystalline polyolefin, and have compositions containing only butyl rubber, inorganic filler, and additives. Example 5 contains 0.5 mass% of crystalline polyolefin.

In addition, in all of Examples 1 to 5, the proportion of inorganic filler relative to the total of 100% by mass of butyl-based rubber and crystalline polyolefin is 100% by mass or more. In addition, in Examples 1 to 5, the proportion of butyl rubber in the butyl-based rubber is 20% by mass, and the proportion of polyisobutylene is 10% by mass. As mentioned above, Examples 1 to 4 do not include crystalline polyolefin, but only Example 5 contains 0.5% by mass of polyethylene.

As for the inorganic filler, Example 1 contains 30% by mass of talc, which is a non-flammable material, 10% by mass of carbon black, which functions as an adsorbent (activated carbon) for oxygen and combustion gases, and 20% by mass of zeolite 4A, which functions as an adsorbent for combustible gases. In addition, it contains 10% by mass of a tackifier as an additive.

In Example 2, the amount of talc in the inorganic filler was reduced from 30% by mass in Example 1 to 20% by mass, and 10% by mass of expanded graphite was added instead.

Example 3 is based on Example 1, but contains 10% by mass of calcium carbonate instead of talc as a non-flammable material, and further contains 20% by mass of magnesium hydroxide, which functions as a flame retardant that releases water when burned.

In Example 4, the composition of the components is the same as in Example 1, but the composition ratio is changed to 25% by mass of talc, 25% by mass of carbon black, and 10% by mass of adsorbent.

In Example 5, based on Example 1, 0.5% by mass of polyethylene was added as a crystalline polyolefin, which was subtracted from the talc to make it 29.5% by mass, and the mass composition was also changed to 20% by mass of carbon black, 15% by mass of adsorbent, and 5% by mass of adsorption imparting agent.

On the other hand, as a comparative example, Comparative Example 1 is an example in which an existing hot melt butyl-based sealant is used, and the ratio of inorganic filler to a total of 100 parts by mass of butyl-based rubber and crystalline polyolefin is 33 parts by mass, which is a different composition from Examples 1 to 5, where the ratio is 100 parts by mass or more.

Comparative Example 2 has a composition similar to that of the examples described in WO 2018/199177. The proportion of the butyl-based rubber to the total amount of the butyl-based rubber and the crystalline polyolefin is 89.8% by mass, which is less than 98%, and is a composition smaller than those of Examples 1 to 5. In addition, the proportion of the inorganic filler to 100 parts by mass of the total of the butyl-based rubber and the crystalline polyolefin is 84 parts by mass, which is significantly smaller than the 100 parts by mass or more of Examples 1 to 5.

Comparative examples 3 and 4 have the same compositions as composition examples 9 and 12 in Table 1 of Patent Document 1, respectively, and the ratio of inorganic filler to a total of 100 parts by mass of butyl rubber and crystalline polyolefin is 91 parts by mass, which is significantly smaller than the 100 parts by mass or more in Examples 1 to 5.

Examples 1 to 5 and Comparative Examples 1 to 4 were constructed with this composition, and fire resistance tests were conducted on Examples 1 to 5 and Comparative Examples 1 and 2. Examples 1 to 5 passed the test, while Comparative Examples 1 to 4 failed.

The 500°C combustion residue was evaluated as a more precise evaluation index than pass or fail. The 500°C combustion residue was measured using a thermogravimetric analyzer (TA Instruments Q50 thermogravimetric analyzer) by heating from room temperature to 900°C at a heating rate of 10°C/min in an air atmosphere, and the amount of residue at 500°C was determined. Examples 1 to 5 were all around 60%, but Comparative Examples 1 to 4 were all less than 40%, resulting in residues of 25% and 30%, respectively, less than half that of Examples 1 to 5.

These results show that the ratio of inorganic filler has a significant effect on the fire resistance of the secondary sealant, and that by setting this to 100 parts by mass or more, the fire resistance of the butyl rubber sealant can be significantly improved.

Looking at examples 1 to 5, example 5 had the highest score at 63%, followed by example 1 at 60%, example 2 at 59%, example 4 at 58%, and example 2 at 55%.

Although this is merely a hypothesis, the results of Example 5 suggest that the inclusion of a small amount of crystalline polyolefin may improve fire resistance, and the results of Example 2 suggest that increasing the amount of talc, a non-combustible material, may be more effective in improving fire resistance than relying on the flame retardant effect of moisture generation from magnesium hydroxide.

In particular, when comparing the 500°C combustion residues of Comparative Examples 1 and 2, the effect of polyethylene and talc, which are crystalline polyolefins, is 5% higher in Comparative Example 2, which contains polyethylene and talc, than in Comparative Example 1, suggesting that they may have a greater impact than other components.

In this way, the secondary sealant according to this embodiment can improve the fire resistance of double-glazed glass, even when a resin spacer or a resin spacer containing a desiccant is used in the double-glazed glass, and can leave a large amount of residue even when exposed to flame radiation, allowing the glass to pass the fire resistance test based on ISO834-1:1999.

The JIS A hardness was also measured at 25°C. The JIS A hardness was measured in accordance with JIS K7215, using a type A hardness tester (GS-619RG, manufactured by Techclock) to measure the value immediately after pressure application.

Although the preferred embodiments and examples of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments and examples, and various modifications and substitutions can be made to the above-described examples without departing from the scope of the present invention.

For example, in the insulating glass of Examples 1 to 5, if chemically strengthened glass is used instead of the wired glass, or if low-expansion fireproof glass, heat-resistant strengthened glass, or heat-resistant crystallized glass that is certified as heat-resistant plate glass by the Architectural Openings Association is used, the glass can also pass the fire resistance test.

Reference Signs List 10: First glass 10a: Fire-resistant glass 11: Second glass 11a: Low-E glass 20, 21: Spacer 30: Desiccant 40: Hollow layer 50: Primary seal material 60: Secondary seal material 100, 101: Double-insulating glass

Claims (11)

A sealing material for sealing the peripheral portion of a double-glazing unit in which two or more glass sheets are arranged opposite each other and spaced apart via a spacer so as to form a hollow layer therebetween,
The sealing material has a butyl-based rubber and an inorganic filler, and the proportion of the butyl-based rubber relative to the total amount of the butyl-based rubber and the crystalline polyolefin is 98% by mass or more and 100% by mass or less, and the proportion of the crystalline polyolefin is 0% by mass or more and less than 2% by mass (including the case where the crystalline polyolefin is not included),
The ratio of the inorganic filler to 100 parts by mass of the total of the butyl-based rubber and the crystalline polyolefin is 100 parts by mass or more and 250 parts by mass or less,
The butyl-based rubber includes polyisobutylene,
The sealing material has a polyisobutylene content of 5% by mass or more and 20% by mass or less.
Sealing material. The sealant was used as a secondary sealant for a double-glazed glass having a first glass and a second glass disposed opposite each other, the double-glazed glass was attached to the opening of a furnace, and the peripheral portion of the double-glazed glass was sealed with the sealant. The first glass was a wire-reinforced glass having a thickness of 6.8 mm and having fire resistance, and the second glass was a Low-E glass having a thickness of 5 mm. The sealant had a thickness of 12 mm, and the width and height of the first glass and the second glass were 900 mm and 2000 mm, respectively. A burner was disposed opposite the first glass. A heating curve conforming to ISO834-1:1999 (T = 345 log10 (8t + 1) + 20, T: furnace temperature (°C), t: 2. The sealing material according to claim 1, wherein, when the double-glazing material is heated for 20 minutes in accordance with a test time (min) in accordance with ISO 834-1:1999 , a flame from the burner does not penetrate the double-glazing material, and a state in which no flame is generated for 10 consecutive seconds is maintained for 20 minutes. 3. The sealing material according to claim 1, wherein the ratio B/A of the mass A of the sealing material at room temperature to the mass B of the sealing material when heated from room temperature to 500° C. at a rate of 10° C./min in an air atmosphere is 40% or more. The sealing material according to any one of claims 1 to 3 , wherein the butyl-based rubber is not crosslinked. The sealing material according to claim 1 , wherein the inorganic filler contains an adsorbent. The sealing material according to claim 1 , wherein the inorganic filler contains carbon black. The sealing material according to any one of claims 1 to 6 , having a JIS A hardness of 55 to 90 at 25°C. The sealing material according to any one of claims 1 to 7, further comprising a thermal decomposition accelerator as an additive. Two glass plates arranged opposite each other;
a spacer provided between the two glass plates and defining a distance between the two glass plates;
and the sealant according to any one of claims 1 to 8 , surrounding an outer periphery of the spacer and sealing a space formed by the spacer and the two glass plates. The insulating glass according to claim 9 , wherein one of the two glass plates is a fire-resistant glass and the other is a Low-E glass. The insulating glass according to claim 9 or 10 , further comprising a second sealant between the spacer and the two glass plates, the second sealant having a composition different from that of the sealant.

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