WO2013153813A1

WO2013153813A1 - Vacuum heat insulator, and refrigerator-freezer and home wall provided with same

Info

Publication number: WO2013153813A1
Application number: PCT/JP2013/002464
Authority: WO
Inventors: 上門　一登; 法幸宮地; とも子安宅; 永幡　真也; 裕一秦
Original assignee: パナソニック株式会社
Priority date: 2012-04-11
Filing date: 2013-04-11
Publication date: 2013-10-17

Abstract

This vacuum heat insulator (10) is provided with a heat-insulating core material (11) and a sheath material (12) which exhibits gas barrier properties and which encloses the core material in a decompressed and closed state. Glass fibers that constitute the core material (11) have at least one of the following constituent features: [i] containing not more than 5 mol% of CaO and being hydrophobic, [ii] the ten point average roughness (Rz) of the surface of the glass fibers is not lower than 30, or [iii] containing not less than 16 mol% of SrO and BaO, containing not less than 7 mol% of K₂O and containing not less than 4 mol% of B₂O₃.

Description

Vacuum heat insulating material, and refrigerator-freezer and housing wall provided with the same

The present invention relates to a vacuum heat insulating material provided with a core material mainly composed of glass fiber, and a refrigerator-freezer and a housing wall using the same, and in particular, suppresses deterioration over time or effectively transfers heat of the core material. The present invention relates to a vacuum heat insulating material that can be suppressed to improve heat insulating performance, or both, and a refrigerator-freezer and a housing wall using the vacuum heat insulating material.

The vacuum heat insulating material generally has a structure in which a core material mainly composed of glass fiber is sealed under reduced pressure inside an outer packaging material having gas barrier properties. Therefore, heat transfer due to a gas component can be suppressed as compared with a case where a similar core material mainly composed of glass fibers is used in a normal pressure state. The vacuum heat insulating material having such a configuration can be widely used for electrical appliances such as refrigerators and refrigerators and jar pots, or residential materials such as housing walls, bathtubs and floor heating.

Here, it is known that the glass fiber which is the core material of the vacuum heat insulating material has a hygroscopic property. This is because the glass material itself used for the glass fiber has high affinity for water (hydrophilicity), and its cross-sectional area is as small as several μm and has a large surface area.

Although general glass can be considered to be stable to water in practical use, in reality, deterioration occurs due to the presence of moisture. Therefore, when the state in which the glass fiber absorbs moisture is continued, moisture attached to the fiber surface enters the inside of the fiber, causing the glass fiber to deteriorate, and as a result, the strength and heat insulating performance of the core material are lowered. Therefore, when manufacturing a vacuum heat insulating material, it is necessary to sufficiently dry the core material before sealing, but it takes a long time for moisture to be removed by drying, resulting in a decrease in manufacturing efficiency and an increase in cost. There is a fear.

Therefore, for example, Patent Document 1 discloses a technique for manufacturing a vacuum heat insulating material using a fiber layer having high durability (water resistance) to water. The fiber layer used is mainly glass fiber, and when the dried fiber layer is left in a constant temperature and humidity chamber at 25 ° C. and 50 RH% for 24 hours, the adsorbed moisture content of the fiber layer is 0.3% by weight or less. It has become.

In recent years, vacuum insulation has been required to further improve heat insulation performance in order to further promote energy saving.

Here, since the inside of the outer packaging material is depressurized in the vacuum heat insulating material, the heat conduction of the gas component has little influence on the heat transfer, and the heat conduction of the core material which is a solid component is mainly used. . Therefore, in order to improve the heat insulating performance of the vacuum heat insulating material, it is important to suppress the heat conduction of the core material.

For example, Patent Document 2 discloses a technique for forming a core material using a nonwoven fabric in which inorganic fibers such as glass fibers are arranged in a predetermined direction. In this technique, the core material is configured by laminating a plurality of non-woven fabrics, and the non-woven fabric used is one in which inorganic fibers are extended in a direction substantially parallel to the surface thereof. Also disclosed is that if the stiffness of the inorganic fiber is low, the inorganic fiber is bent and entangled between the fibers, and the contact area between the fibers increases, so that the thermal conductivity increases and the heat insulation performance deteriorates. Therefore, Patent Document 2 also discloses that the average fiber diameter of the inorganic fibers is preferably in the range of 3 to 15 μm, and the average fiber length is preferably in the range of 3 to 15 mm. Has been.

JP 2008-232257 A JP 2010-242868 A

However, the technique disclosed in Patent Document 1 may not be able to suppress aging deterioration of the vacuum heat insulating material.

Even if the outer packaging material of the vacuum heat insulating material has gas barrier properties, it does not completely block various gases including water vapor. For example, under certain conditions such as high temperature and high humidity, the gas barrier properties may decrease. Are known. Therefore, depending on the use conditions of the vacuum heat insulating material, it may not be possible to sufficiently suppress the intrusion of water vapor from the outside air. Therefore, if it is a use used for a long period of time, such as a refrigerator-freezer or a housing wall, it is necessary to consider the influence of water vapor entering from the outside air even after being sealed in the outer packaging material. In Patent Document 1, no consideration is given to the influence of such water vapor penetration.

Further, with the technique disclosed in Patent Document 2, it is difficult to further reduce the heat conduction of the core material of the vacuum heat insulating material.

Patent Document 2 discloses that the improvement limit of the conventional heat insulation performance can be exceeded by configuring the core material using a nonwoven fabric with improved orientation of inorganic fibers. It has also been suggested that the average fiber diameter and the average fiber length of the inorganic fibers are controlled within a predetermined range to suppress the decrease in the rigidity of the inorganic fibers. However, nothing is disclosed about improving the heat insulating performance from the viewpoints other than the orientation of the inorganic fibers, the fiber diameter, or the fiber length.

As described above, since the vacuum heat insulating material encloses the core material mainly composed of glass fiber under reduced pressure, the heat conduction by the core material occupies most of the vacuum heat insulating material. Therefore, even if it is the nonwoven fabric which improved the orientation of the inorganic fiber which optimized the fiber diameter and fiber length as disclosed by patent document 2, as long as the inorganic fiber is a general purpose glass fiber, it is thermal conductivity. It is not possible to expect further reduction. In other words, it can be considered that the use of general-purpose glass fibers itself hinders the reduction of the thermal conductivity of the vacuum heat insulating material.

As described above, in recent years, with the promotion of energy saving, in refrigerators and refrigerators, it is required to further improve the heat insulation performance of the heat insulation box to further reduce the energy consumed for cooling. There is a demand for further reducing the energy consumed for air conditioning by improving the heat insulation performance. Therefore, it is an important issue to further reduce the heat conduction of the core material.

As described above, in order to further improve the practicality of the vacuum heat insulating material, it is very possible to suppress the aging deterioration of the core material and / or reduce the thermal conductivity of the core material. It is important.

The present invention has been made in order to solve such problems, and suppresses aging deterioration of a core material mainly composed of glass fibers even when used for a long period of time, and is mainly composed of glass fibers. To provide a vacuum heat insulating material capable of realizing at least one of exhibiting good heat insulating properties by further reducing the heat conduction of the core material, and a refrigerator-freezer and a housing wall including the same. Objective.

In order to solve the above problems, a vacuum heat insulating material according to the present invention includes a core material having heat insulation properties, and an outer packaging material that has gas barrier properties and encloses the core material in a sealed state under reduced pressure. The core material has [i] at least a CaO content of 5 mol% or less and hydrophobicity, [ii] a ten-point average roughness Rz of the fiber surface is 30 or more, and [ iii] SrO and BaO content is 16 mol% or more, and K ₂ O content 7 mol% or more and the content of B ₂ O ₃ is 4 mol% or more, at least the constituent elements of It is comprised from the glass fiber which satisfy | fills either.

According to the above configuration, if the glass fiber has the structural requirement [i], it is possible to suppress the aging deterioration of the core material mainly composed of the glass fiber even when used for a long time. In addition, if the glass fiber has the constituent requirement [ii] or [iii], good heat insulation can be exhibited by further reducing the heat conduction of the core material mainly composed of the glass fiber. Furthermore, if the glass fiber has all of the constituent requirements [i] to [iii], it is possible to suppress the deterioration of the core material over time and further reduce the heat conduction of the core material. Therefore, the heat insulating property of the obtained vacuum heat insulating material can be improved. As a result, this vacuum heat insulating material can be suitably used in fields such as a refrigerator-freezer or a housing wall.

Further, the present invention includes a vacuum heat insulating material having the above-described configuration, an outer box serving as an outer housing, and an inner box located in the outer box and having an inside serving as a storage space for storing articles. And a refrigerator-freezer having a configuration in which the vacuum heat insulating material is disposed between the outer box and the inner box.

Further, the present invention includes a residential wall having a vacuum heat insulating material having the above-described configuration and a load-bearing wall, wherein the vacuum heat-insulating material is disposed on the back side of the load-bearing wall.

The above object, other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings.

In the present invention, with the above configuration, the deterioration over time of the core material mainly composed of glass fiber is suppressed even after long-term use, and the heat conduction of the core material mainly composed of glass fiber is further reduced. Thus, there is an effect that it is possible to provide a vacuum heat insulating material capable of realizing at least one of exhibiting good heat insulating properties, a refrigerator-freezer and a housing wall including the same.

FIG. 1 is a schematic cross-sectional view showing an example of the configuration of the vacuum heat insulating material used in the present invention. FIG. 2 is a schematic perspective view showing an example of the configuration of the refrigerator-freezer according to Embodiment 1 of the present invention, including the vacuum heat insulating material shown in FIG. FIG. 3 is a schematic cross-sectional view showing an example of a configuration of a residential wall according to Embodiment 2 of the present invention, which includes the vacuum heat insulating material shown in FIG. FIG. 4A is a diagram of an observation result of a scanning probe microscope showing a state of a fiber surface of a hydrophobic glass fiber used in a vacuum heat insulating material according to an example of the present invention, and FIG. 4B is related to a comparative example. It is a figure of the observation result of a scanning probe microscope which shows the state of the fiber surface of the conventional glass fiber used for the vacuum heat insulating material.

The vacuum heat insulating material according to the present invention includes a core material having heat insulating properties, and an outer packaging material having gas barrier properties and enclosing the core material in a vacuum sealed state, and the core material is at least CaO. The content is 5 mol% or less, has hydrophobicity, the ten-point average roughness Rz of the fiber surface is 30 or more, the content of SrO and BaO is 16 mol% or more, and K ₂ O As long as it is made of glass fiber having a content of 7 mol% or more and a content of B ₂ O ₃ of 4 mol% or more.

According to the above-described configuration, it is possible to suppress the deterioration over time of the core material mainly composed of glass fiber even after long-term use, and further reduce the heat conduction of the core material mainly composed of glass fiber. Good thermal insulation can also be exhibited. Therefore, the heat insulating property of the obtained vacuum heat insulating material can be improved.

Alternatively, the vacuum heat insulating material according to the present invention includes a core material having heat insulation properties, and an outer packaging material having gas barrier properties and enclosing the core material in a sealed state under reduced pressure, wherein the core material is at least The CaO content may be 5 mol% or less, and the glass fiber may have hydrophobicity.

According to the above configuration, the deterioration over time of the core material mainly composed of glass fiber can be suppressed even after long-term use. Therefore, the heat insulating property of the obtained vacuum heat insulating material can be improved.

Alternatively, the vacuum heat insulating material according to the present invention includes a core material having a heat insulating property, and an outer packaging material having a gas barrier property and enclosing the core material in a sealed state under reduced pressure, The fiber surface may have a ten-point average roughness Rz of 30 or more.

According to the above configuration, good heat insulation can be exhibited by further reducing the heat conduction of the core material mainly composed of glass fiber. Therefore, the heat insulating property of the obtained vacuum heat insulating material can be improved.

Or the vacuum heat insulating material which concerns on this invention is equipped with the core material which has heat insulation, and the outer packaging material which has the gas barrier property and encloses the said core material in a pressure-reduced sealing state, The said core material is SrO. And a BaO content of 16 mol% or more, a K ₂ O content of 7 mol% or more, and a B ₂ O ₃ content of 4 mol% or more.

In the vacuum heat insulating material having the above structure, the alkali elution amount based on JIS R3502 may be 300 μg / g or less as long as the glass fiber has hydrophobicity.

In the vacuum heat insulating material having the above-described configuration, the glass fiber has an average diameter in the range of 0.1 to 10 μm, and the core material is oriented in a direction intersecting the glass fiber with respect to the heat transfer direction. You may be comprised so that it may make.

In the vacuum heat insulating material having the above-described configuration, the glass fiber may include at least one of SrO, BaO, and MgO.

Further, in the vacuum heat insulating material having the above structure, when the glass fiber contains the SrO, the content thereof is in the range of 1 to 12 mol%, and when the glass fiber contains the BaO, When the content is in the range of 1 to 8 mol% and the MgO is contained, the content may be in the range of 5 to 12 mol%.

Moreover, in the vacuum heat insulating material having the above-described configuration, the glass material constituting the glass fiber may have a Young's modulus of 71 GPa or more.

Further, in the vacuum heat insulating material having the above configuration, the porosity of the core material may be 90% or more.

Further, in the vacuum heat insulating material having the above configuration, the thermal conductivity of the glass material forming the glass fiber may be 1 W / mK or less.

Further, in the vacuum heat insulating material having the above-described configuration, the glass fiber may be manufactured using a cathode ray tube glass as a raw material.

The refrigerator-freezer according to the present invention includes the vacuum heat insulating material having the above-described configuration, an outer box serving as an external housing, an inner box positioned in the outer box, and the inside serving as a storage space for storing articles, And the vacuum heat insulating material is arranged between the outer box and the inner box.

In the refrigerator-freezer having the above-described configuration, the vacuum heat insulating material is disposed between the outer box and the inner box, and is disposed at a position that is at least one of the left and right side surfaces and the back surface of the refrigerator-freezer. May be.

Further, the residential wall according to the present invention is configured to include the vacuum heat insulating material having the structure described above and a load bearing wall, and the vacuum heat insulating material is disposed on the back surface side of the load bearing wall.

In the residential wall having the above-described structure, a heat insulating panel material configured by fixing the vacuum heat insulating material to the back surface of the load bearing wall may be used.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted.

(Embodiment 1)
[Configuration of vacuum insulation]
First, an example of the vacuum heat insulating material according to the present embodiment will be specifically described with reference to FIG. As shown in FIG. 1, the vacuum heat insulating material 10 which concerns on this Embodiment is comprised from the core material 11 and the outer packaging material 12 (or jacket material). The core material 11 is comprised from the glass fiber mentioned later, and has heat insulation. The outer packaging material 12 has a gas barrier property and encloses the core material 11 inside in a vacuum-sealed state.

The core material 11 is obtained by forming glass fibers into a board shape. Specifically, for example, the glass fibers are laminated in a flat plate shape, and the laminate is placed in a jig and pressed. Is heated in a pressurized state and molded to have a density and thickness in a predetermined range. The pressurizing condition, heating condition and the like of the glass fiber are not particularly limited, and known conditions can be suitably used in the field of manufacturing the vacuum heat insulating material 10.

The core material 11 is a structure for exhibiting the heat insulating function in the vacuum heat insulating material 10. The apparent thermal conductivity λapp is generally the sum of the gas thermal conductivity λg, the solid thermal conductivity λs, the radiation thermal conductivity λr, and the convection thermal conductivity λc, It is expressed in

λapp = λg + λs + λr + λc (Formula 1)
Here, heat conduction by convection can be neglected under reduced pressure of about 20 kPa or less or a gap diameter of about 1 mm (λc ≈ 0), and heat conduction by radiation is under operating temperature conditions of 100 ° C. or less. There is no effect below (λr ≈ 0). For this reason, the heat conduction of the vacuum heat insulating material 10 is dominated by solid heat conduction (λs) and gas heat conduction (λg) under operating temperature conditions of 100 ° C. or less.

Solid heat conduction can be reduced by reducing the fiber diameter of the glass fibers constituting the core material 11. That is, if the fiber diameter is reduced, the effect of reducing the heat conduction through the fiber and the effect of reducing the heat conduction through the contact point with the adjacent fiber (that is, the effect of increasing the contact resistance) can be obtained. , Solid heat conduction can be reduced. In addition, the preferable range of the average fiber diameter of glass fiber is mentioned later.

In addition, it is possible to make the glass fibers substantially contact each other by orienting the glass fibers in a direction intersecting the heat transfer direction. Thereby, the thermal resistance of the core material 11 increases, and solid heat conduction can further be reduced. The orientation direction of the glass fiber is not particularly limited as long as it is a direction that intersects the heat transfer direction, that is, the thickness direction of the core material 11, but is preferably a (substantially) vertical direction. By orienting the glass fibers vertically, the glass fibers can be easily brought into point contact with each other, so that the thermal resistance of the core material 11 can be easily increased.

Moreover, gas heat conduction can be reduced by increasing the porosity of the core material 11. In the present embodiment, the porosity of the core material 11 is preferably 90% or more. Thereby, the heat insulation performance can be further improved by the combination of the reduction of the fiber diameter of the glass fiber and the regulation of the orientation direction of the glass fiber.

Other conditions of the glass fiber, such as various conditions such as bulk density and thickness, are not particularly limited, and may be any known density and thickness. However, the bulk density is hermetically sealed in the outer packaging material 12. The bulk density is preferably in the range of 210 to 280 kg / m ³ , for example. If it exists in this range, favorable heat insulation performance can be exhibited. The bulk density, thickness, and the like of the core material 11 that is not hermetically sealed are not particularly limited, and typical examples include conditions where the density is 200 kg / m ³ and the thickness is 10 mm.

Further, the core material 11 only needs to be made of glass fibers to be described later, but may contain materials other than glass fibers as necessary. Examples of such other materials include inorganic fibers other than glass fibers such as ceramic fibers, slag wool fibers and rock wool fibers; binder materials such as organic binders, inorganic binders and organic fibers; organic powders and inorganic powders And granule materials such as microcapsule granules. These other materials can be used for the purpose of improving the physical properties (strength, uniformity, rigidity, etc.) of the board-shaped core material 11.

The outer packaging material 12 is a sheet-like material having gas barrier properties, and specifically includes, for example, a laminate in which a resin film is laminated on both surfaces of a metal thin film such as an aluminum foil or an aluminum vapor deposition layer. One of the resin films constituting the laminate is a surface protective layer that becomes the outer surface of the vacuum heat insulating material 10, and the other is a heat-welded layer for holding the core material 11 in a vacuum-sealed state inside. . The type and thickness of the metal thin film, the type and thickness of the resin film, etc. are not particularly limited, and known ones can be suitably used. As a more specific example, a polyethylene terephthalate (PET) film having a thickness of 12 μm as a surface protective layer, an aluminum foil (Al foil) having a thickness of 6 μm as an intermediate layer, and a linear low density having a thickness of 50 μm as a heat welding layer. A laminate film made of a polyethylene (LLDPE) film can be exemplified.

The manufacturing method of the vacuum heat insulating material 10 is not particularly limited, and a known method can be suitably used. Specifically, for example, first, the core material 11 is dried by a drying furnace or the like to remove moisture. Further, the two laminated films are overlapped with the heat-welding layers facing each other, three of the four sides are sealed by heat-welding, and the outer packaging material 12 is formed by forming a bag with one side as an opening. . And after inserting the core material 11 from the said opening part of the outer packaging material 12, and decompressing in decompression equipments, such as a decompression chamber, the said opening part is airtightly sealed by heat welding.

The drying conditions in the drying furnace, the molding conditions of the outer packaging material 12 (sealing conditions by heat welding, etc.), the decompression conditions in the outer packaging material 12, etc. are not particularly limited, and various conditions known in the field of manufacturing the vacuum heat insulating material 10 are used. It can be used suitably. For example, the drying condition can include drying at 140 ° C. for 30 minutes, and the reduced pressure condition can include a condition in which the inside of the outer packaging material 12 is 1 to 200 Pa.

Further, the vacuum heat insulating material 10 may include members other than the core material 11 and the outer packaging material 12. Specifically, for example, a moisture adsorbent that is hermetically sealed together with the core material 11 inside the outer packaging material 12 can be mentioned.

Even if the outer packaging material 12 has a gas barrier property, it is not possible to completely block the water vapor, so there is a possibility that the water vapor may enter the inside through the outer packaging material 12. Here, in the present embodiment, as will be described later, since the glass fiber used for the core material 11 is preferably a hydrophobic glass fiber, moisture is hardly absorbed. Therefore, even if a slight amount of water vapor enters the outer packaging material 12, it is suppressed from adhering to the fiber surface, and therefore the durability of the core material 11 over time can be improved. Furthermore, since the vacuum heat insulating material 10 includes the moisture adsorbent, even a slight amount of water vapor entering the inside can be adsorbed, and the durability of the core material 11 can be further improved.

Although the thermal conductivity of the vacuum heat insulating material 10 according to the present embodiment is not particularly limited, it is preferably 5.4 mW / mK or less, more preferably 3.2 mW / mK or less. Here, the thermal conductivity in the present embodiment may be measured by a method based on JIS A1412 (or ASTM518 or ISO8301).

However, since the thermal conductivity of the vacuum heat insulating material 10 according to the present embodiment is relatively very low, there is a case where it is not possible to sufficiently follow the sensitivity of the thermal conductivity according to the above rules. Therefore, in the present embodiment and the examples to be described later, a value directly measured by a thermal conductivity measuring device (auto λ) HC-074-300 (trade name) manufactured by Eiko Seiki Co., Ltd. is used. Used to evaluate conductivity. Note that HC-074-300 is a measuring device conforming to JIS A1412, ATSM518 and ISO8301.

[Properties of glass fiber]
Next, the property of the glass fiber which comprises the core material 11 is demonstrated concretely. In the present embodiment, the glass fiber used for the core material 11 has (1) a hydrophobic condition that it has hydrophobicity, (2) a surface roughness condition that the state of the fiber surface is relatively rough, and ( 3) What is necessary is just to satisfy | fill the property conditions of at least any one of the rigidity conditions that rigidity is maintained favorable.

First, (1) the hydrophobic condition will be described. The glass fiber satisfying the hydrophobic condition (1), that is, the hydrophobic glass fiber has a lower hydrophilicity than a general glass fiber. Since general glass fiber has high hydrophilicity, it easily absorbs moisture (such as water vapor) in the air, and in contact with moisture, alkali components (especially metal elements of Group 1 of the periodic table excluding hydrogen, That is, alkali metal) is easily eluted. In contrast, the hydrophobic glass fiber in the present embodiment has low hydrophilicity and little elution of alkali components.

The hydrophobicity in the present embodiment can be defined as, for example, the elution amount of the alkali component when it comes into contact with moisture. Specifically, in the present embodiment, the alkali elution amount may be 300 μg / g or less in the alkaline component elution test based on JIS R3502-1995. When the alkali elution amount exceeds 300 μg / g, it can be considered that the alkali component is eluted to the same extent as general glass fibers, and therefore the stability (water resistance) against water as glass fibers is reduced, and the core When the material 11 is configured, it becomes easy to absorb moisture.

Next, (2) surface roughness conditions will be described. In the glass fiber in this Embodiment, compared with a general purpose glass fiber, since the micro unevenness | corrugation exists in the fiber surface, it is not a smooth surface but a rough surface. Specifically, the 10-point average roughness Rz based on JIS B0601-1976 (deleted from JIS B0601-2001) is preferably 30 or more on the fiber surface of the glass fiber.

The ten-point average roughness Rz is extracted from the curve representing the roughness (roughness curve) by the reference length L in the direction of the average line, and the peak from the highest peak to the fifth peak from the average line of this extracted part. Is calculated as the sum of the average value of the absolute values of the altitude (Yp) and the average value of the absolute values of the altitudes (Yv) of the bottom valley from the lowest valley bottom to the fifth. Therefore, it can be said that the ten-point average roughness Rz is obtained by quantifying the highest peak in the range of the reference length L of the roughness curve except for an extraordinary height.

If the fiber surface of the glass fiber is rough so that the ten-point average roughness Rz ≧ 30, the glass fiber is oriented so as to intersect the heat transfer direction. The contact area of the contact points between each other becomes relatively small. That is, compared to the contact area when the fiber surface is smooth, the contact area between the glass fibers is increased because the possibility of contact between the convex portions of the fiber surfaces increases. Get smaller. Therefore, since the thermal resistance of the core material 11 is further increased, the heat insulating performance can be further improved. On the other hand, when the ten-point average roughness Rz is less than 30 (Rz <30), the contact area between the glass fibers tends not to be so small that the thermal resistance can be significantly increased.

Next, (3) rigidity conditions will be described. The glass fiber in the present embodiment is maintained at the same or higher rigidity as compared with a general-purpose glass fiber. Specifically, it is preferable that the Young's modulus of the glass material constituting the glass fiber is 71 GPa. The measurement of Young's modulus is based on JIS R1602.

If the Young's modulus of the glass material is 71 GPa or more, the glass fiber using the glass material can exhibit excellent rigidity. Therefore, since the frequency with which the glass fibers constituting the core material 11 are bent or the glass fibers are entangled can be effectively reduced, the contact area between the glass fibers can be reduced.

In addition, if the glass fiber has good rigidity, the shape retention of the core material 11 composed of the glass fiber is also good, and an increase in the density of the core material 11 can be suppressed or avoided. Therefore, the heat insulation performance of the core material 11 can be further improved. On the other hand, if the Young's modulus of the glass material is less than 71 GPa, the rigidity of the glass fiber using the glass fiber is lowered. Therefore, there is a possibility that the contact area of the glass fibers constituting the core material 11 increases or the density of the core material 11 increases.

In addition, the specific size of the glass fiber in the present embodiment is not particularly limited, but the average diameter may be in the range of 0.1 to 10 μm, and preferably in the range of 3 to 5 μm. If the average fiber diameter is 0.1 μm or less, the productivity of glass fibers deteriorates, or the probability that the glass fibers are intertwined in a complicated manner and become a fiber array parallel to the heat transfer direction increases, and the amount of heat transfer increases. There is a possibility of doing. On the other hand, if the average fiber diameter is 10 μm or more, the productivity of the glass fiber is improved, but since the amount of heat transfer through the fiber is increased and the contact resistance is reduced, the solid heat conduction (λs) is increased. In addition, (1) hydrophobicity conditions, (2) surface roughness conditions, (3) rigidity conditions, and other properties other than the average diameter are not particularly limited as long as they are within the range of known physical properties. Good.

As described above, the glass fiber in the present embodiment may satisfy at least one of (1) hydrophobicity condition, (2) surface roughness condition, and (3) rigidity condition, but at least two conditions Is preferably satisfied, and more preferably all conditions are satisfied.

For example, in glass fiber (hydrophobic glass fiber) satisfying two of (1) hydrophobic condition and (2) surface roughness condition, it is possible to suppress the moisture content by having hydrophobicity, There is an advantage that the roughness of the fiber surface is easily maintained. If the glass fiber is hydrophilic, moisture tends to adhere to the fiber surface, which may corrode the irregularities on the fiber surface and reduce the roughness of the fiber surface. On the other hand, if the glass fiber is hydrophobic, the adhesion of moisture is suppressed, so that the roughness of the fiber surface is easily maintained. As a result, since it becomes easy to maintain a state where the contact area between the glass fibers is small, it is possible to effectively suppress a decrease in thermal conductivity over time.

In addition, since glass fiber (hydrophobic glass fiber) satisfying two of (1) hydrophobic condition and (3) rigidity condition can suppress moisture content by having hydrophobicity, rigidity is reduced. There is an advantage that it is easy to maintain. If the glass fiber is hydrophilic, the core material 11 is likely to contain moisture, whereby an alkali component or the like in the glass fiber is eluted, and the rigidity of the glass fiber may be reduced. On the other hand, if the glass fiber is hydrophobic, the moisture content of the core material 11 is suppressed, so that good rigidity is easily maintained. As a result, it becomes possible to maintain the shape retainability of the core material 11, so that a decrease in thermal conductivity over time can be effectively suppressed.

Moreover, if the two conditions (1) hydrophobicity condition and (3) rigidity condition are satisfied, the reduced pressure state (degree of vacuum) inside the vacuum heat insulating material 10 can be made relatively high. If the glass fiber satisfies the (3) rigidity condition, the density of the core material 11 becomes relatively low, so that an appropriate gap is secured between the glass fibers. Furthermore, if the glass fiber satisfies (1) the hydrophobic condition, the core material 11 is difficult to contain moisture. For this reason, even if moisture is contained in the core material 11, the moisture is easily detached due to the hydrophobicity and appropriate gaps. Thereby, even when the core material 11 is dried and when the inside of the outer packaging material 12 is depressurized, moisture is easily detached from the core material 11, and moisture hardly remains inside the outer packaging material 12. As a result, the degree of vacuum inside the vacuum heat insulating material 10 can be relatively increased.

In addition, in the glass fiber satisfying the two conditions (2) surface roughness condition and (3) rigidity condition, moderate voids are maintained between the glass fibers due to excellent rigidity, and the density of the core material 11 can be reduced. In addition, since the contact area between the glass fibers can be reduced by the roughness of the fiber surface, the thermal conductivity of the core material 11 can be further reduced. Here, if the fiber surface is rough, stress concentration is likely to occur in the glass fiber, and therefore the glass fiber tends to be broken or broken. However, if the glass fiber has excellent rigidity, breakage or breakage of the glass fiber can be effectively suppressed. Thereby, a moderate space | gap between glass fibers can be maintained much more favorably.

Furthermore, if all the property conditions of (1) hydrophobicity condition, (2) surface roughness condition, and (3) rigidity condition are satisfied, all the synergistic effects by satisfying the above two conditions are realized. . Therefore, the obtained vacuum heat insulating material 10 can further reduce the thermal conductivity, and can also effectively suppress a decrease in the thermal conductivity over time.

[Composition of glass material constituting glass fiber]
The glass material constituting the glass fiber in the present embodiment may be a composition that satisfies the above-mentioned property conditions (1) to (3). Therefore, the specific composition of the glass material is not particularly limited, but the composition satisfies at least one of the following two composition conditions, preferably both.

First, the first composition condition is a condition in which the CaO content is 5 mol% or less. By satisfying the first composition condition, at least (1) the hydrophobic condition can be satisfied among the property conditions described above.

Further, when the glass material satisfies the first composition condition, it is preferable that the glass material further contains at least one of SrO, BaO, and MgO. In other words, when the glass material in the present embodiment satisfies the first composition condition, the group consisting of oxides of Mg, Ca, Sr and Ba, which are elements included in Group 2 elements of the periodic table ( For convenience of explanation, it is referred to as “Group 2 oxide group.”), CaO and at least one oxide of another element are included, and CaO is preferably 5 mol% or less. Note that a composition condition containing at least one of SrO, BaO, and MgO is referred to as a sub-composition condition for convenience of explanation.

Here, the sub-composition condition may be any condition as long as it contains at least one oxide other than CaO in the group 2 oxide group. Specifically, any one of SrO, BaO, and MgO is used. It may contain only seeds, may contain two kinds (SrO and BaO, or SrO and MgO, or BaO and MgO), or may contain all three kinds. The content of these oxides is not particularly limited, but preferably, the content of SrO is in the range of 1 to 12 mol%, the content of BaO is in the range of 1 to 8 mol%, and MgO The content of may be in the range of 5 to 12 mol%.

Among the group 2 oxide groups contained in the composition of the glass material, if at least the content of CaO is 5 mol% or less (that is, if the first composition condition is satisfied), the glass fiber obtained is generally Hydrophobic glass fibers that are improved in hydrophobicity compared to typical glass fibers and are less likely to cause moisture to adhere to the fiber surface can be obtained.

Further, in the group 2 oxide group contained in the composition of the glass material, if CaO is 5 mol% or more and contains at least one of SrO, BaO and MgO (that is, the first If the composition conditions and sub-composition conditions are satisfied), the hydrophobicity of the glass fiber can be improved. In particular, if the content of the group 2 oxide group (including CaO) is within the above range, Further, the hydrophobicity of the glass fiber can be further improved. Therefore, since the hygroscopicity of the core material 11 can be reduced, good heat insulating properties can be exhibited.

Further, if the glass material satisfies at least the first composition condition, the glass fiber used for the core material 11 can be made hydrophobic, so even if a minute amount of moisture is present inside the outer packaging material 12, the fiber interior It becomes possible to suppress effectively entering. As a result, even if water vapor penetrates slightly from the outside by using the vacuum heat insulating material 10 for a long period of time, it is possible to effectively suppress the deterioration of the glass fiber due to the water vapor, and the heat insulation performance is stable over a long period of time. Can be maintained. Further, since the core material 11 itself has a low hygroscopicity, the core material 11 can be easily dried in the manufacturing process, so that the manufacturing efficiency can be improved or the manufacturing cost can be reduced.

Further, the glass fiber in the present embodiment has an alkali component, that is, a Group 1 metal element (more specifically, its oxide) because the content of the Group 2 oxide group in the glass material falls within the above range. The content of is relatively reduced. Therefore, in addition to the reduction of the alkali elution amount due to the hydrophobicity, the alkali component can be reduced in the first place, so that the alkali elution amount can be further reduced. As a result, the deterioration of the glass fiber can be further suppressed, and the deterioration of the heat insulating performance can be suppressed even when the vacuum heat insulating material 10 is used for a long time.

Furthermore, in the glass fiber in the present embodiment, if the glass material that satisfies the sub-composition satisfies all of MgO, SrO, and BaO as the group 2 oxide group, (2) surface roughness condition is realized. It becomes possible to do. That is, by including all group 2 oxide groups, it is possible to achieve an appropriate fiber surface roughness as shown in the examples described later. When the glass material satisfies the sub-composition condition, if the group 2 oxide group contains SrO and BaO, the content of these SrO and BaO is preferably 10 mol% or more. More preferably, it is at least mol%.

Next, the second composition condition is that the content of SrO and BaO is 16 mol% or more, the content of K ₂ O is 7 mol% or more, and the content of B ₂ O ₃ is 4 mol% or more. It is a condition that there is. This second composition condition includes sub-condition 1 in which the SrO and BaO contents are 16 mol% or more, sub-condition 2 in which the K ₂ O content is 7 mol% or more, and a B ₂ O ₃ content of 4 It consists of sub-condition 3 of mol% or more. Therefore, each of these subconditions 1 to 3 will be specifically described.

First, sub-condition 1 will be described. In conventional heat insulating materials, general-purpose glass fibers are often used. In the glass material constituting this general-purpose glass fiber, the content of SrO and BaO is 1 mol% or less and is often close to 0 mol%. This is because SrO and BaO are relatively expensive among the oxides used in the glass field, and as a glass material for glass fibers, soda glass cullet that is relatively easily available and inexpensive is generally used. Because.

Here, when the glass material contains a group 2 oxide group such as MgO, SrO or BaO as a modified oxide, the glass network structure is cut due to the structure of the glass material. Therefore, the thermal vibration transmitted through the network structure can be reduced, and as a result, heat conduction as a glass material can be suppressed. In particular, Sr or Ba has a large atomic weight among the Group 2 elements (or alkaline earth metals) of the periodic table, so that the glass density ρ can be increased. Thereby, the effect which suppresses the heat conduction of a glass raw material becomes large.

Further, as described above, by including the entire group 2 oxide group, it is possible to satisfy (2) the surface roughness condition among the property conditions described above. Therefore, if the glass material satisfies the second composition condition and contains CaO and MgO, the glass fiber using the glass material satisfies (2) surface roughness condition.

Next, the lower condition 2 will be described. Among alkali metals, since K has a large ionic radius, the glass material is kept soft (low viscosity) by containing a large amount of K ₂ O, which is an oxide of K. Therefore, good hydrophobicity of the glass material can be realized by the mixing action of K ₂ O and Na ₂ O. Therefore, among the above-mentioned property conditions, (1) the hydrophobicity condition can be satisfied.

When the glass material satisfies the lower condition 2, it is preferable that the molar ratio is within the range of Na ₂ O / K ₂ O = 0.80 to 2.0, and within the range of 0.90 to 1.7. More preferably. When the mixing ratio of K ₂ O and Na ₂ O is within this range, the content of K ₂ O is relatively increased as compared with general soda glass cullet. Thus, it is possible to satisfactorily soften the glass material by K ₂ O, (1) can be hydrophobic conditions also favorably implemented. Here, even when only the first composition condition is satisfied, the mixing ratio of Na ₂ O / K ₂ O is preferably within the above range.

Next, sub-condition 3 will be described. In order to suppress the heat conduction of the glass material, it is effective to add a group 2 oxide group as a modified oxide to cut the glass network structure as described above. However, the cutting of the network structure decreases the Young's modulus of the glass material, and thus causes a decrease in the rigidity of the glass fiber made of the glass material. If the rigidity of the glass fiber is lowered, the contact between the glass fibers is increased and the density of the core material 11 is also increased, leading to deterioration of the heat insulating performance.

On the other hand, when the glass material contains 4 mol% or more of B ₂ O ₃ , the meshwork can be made dense. Therefore, the Young's modulus can be improved without increasing the heat conduction. As a result, (3) the rigidity condition can be satisfied among the property conditions described above.

Further, B ₂ O ₃ not only makes the network structure of the glass material dense, but also contributes to the suppression of thermal vibration that transmits the network structure. Specifically, since the atomic weight of B is relatively small compared to Si or O, in the Si—O—B bond in the network structure, the OB bond blocks thermal vibration of the Si—O bond. Or exerts a mitigating action. Thereby, the thermal vibration which transmits a network structure is suppressed.

In the glass fiber in the present embodiment, the glass material only needs to satisfy the first composition condition or the second composition condition described above. Preferably, all of the first composition condition, sub-composition condition, and second composition condition are satisfied. In this case, the preferable range of the content of the group 2 oxide group is partly different from the range when only the sub-composition conditions are satisfied.

Specifically, when the glass material satisfies the sub-composition conditions, as described above, the SrO content is in the range of 1 to 12 mol%, and the BaO content is in the range of 1 to 8 mol%. The MgO content is preferably in the range of 5 to 12 mol%. On the other hand, if the glass material satisfies both the sub-composition condition and the second composition condition, the SrO content is the same in the range of 1 to 12 mol%, but the BaO content is the same. Is preferably in the range of 1 to 10 mol%, and the MgO content is preferably in the range of 0.1 to 12 mol%.

When the glass material satisfies the sub-composition condition and the second composition condition and contains both SrO and BaO, the total content of SrO and BaO should be 10 mol% or more. What is necessary is just 16 mol% or more. The first composition condition and the second composition condition are independent composition conditions, but by satisfying both of these composition conditions, the composition of the glass material can be further optimized. In particular, if the first composition condition is satisfied by a combination of the sub-composition conditions and the second composition condition is satisfied, any of the above-described property conditions (1) to (3) can be realized. It becomes.

In addition, the thermal conductivity of the glass material in this Embodiment should just be 1 W / mK or less. Here, the thermal conductivity of the glass material is measured based on JIS R1611. Specifically, when the specific heat of the glass material is Cp, the thermal diffusion coefficient of the glass material is α, and the density of the glass material is ρ, the thermal conductivity λ of the glass material is calculated based on the following equation 2. .

Λ = Cp × α × ρ (Formula 2)

[Glass fiber manufacturing method]
The manufacturing method of the glass fiber in this Embodiment is not specifically limited, If a raw material is adjusted so that content of the said 2 group oxide group may enter in the said range, it can use suitably various well-known methods. it can. As a particularly preferred example, there is a method of producing glass fibers by a known fiberizing technique using CRT glass as a raw material.

CRT glass contains K, MgO, BaO and SrO, and the content of CaO is relatively low. Then, the glass tube cullet which grind | pulverized the cathode ray tube glass discarded and was processed into the particle size of the predetermined range is manufactured, and the vacuum heat insulating material 10 which concerns on this Embodiment by using this tube tube glass cullet as a raw material of the core material 11 It can be manufactured easily. In recent years, due to the rapid spread of liquid crystal panel displays, a large amount of cathode ray tubes that have been used for televisions or computer displays in the past have been discarded. By producing the core material 11 using a cathode ray tube glass cullet as a raw material, In addition, it becomes possible to effectively reuse CRT glass.

Specifically, as a method for producing glass fiber using a cathode ray tube glass cullet, for example, a raw material composition is prepared using a cathode ray tube glass cullet, and then the raw material composition is melted to obtain a centrifugal fiberizing apparatus. A method of producing glass fibers by causing the glass melted by the outflow from a large number of holes.

Here, when a cathode ray tube glass cullet is used as the raw material composition, the fiber surface state of the produced glass fiber is such that the ten-point average roughness Rz is 30 or more as in the above-mentioned (2) surface roughness condition. It becomes rough. This is because the cathode ray tube glass cullet contains MgO, BaO and SrO (sub-composition condition of the first composition condition or sub-condition 1 of the second composition condition), and as a raw material, production of ordinary glass fiber It is estimated that moderate roughness of the fiber surface can be realized because substances with different characteristics are mixed with each other and the mixing state of the raw material composition is moderately dispersed (not well mixed). .

In addition, although all the raw material compositions may be comprised with cathode ray tube glass cullet, you may mix | blend glass cullet (plate glass cullet, bottle glass cullet, etc.) other than cathode ray tube glass cullet as needed. At this time, when the first composition condition and the sub-composition condition are satisfied, the blending amount may be appropriately adjusted so that the content of the group 2 oxide group is within the above range. Even when the second composition condition is satisfied, B ₂ O ₃ may be added or the mixing ratio of K ₂ O and Na ₂ O may be adjusted so as to satisfy the lower conditions 1 to 3.

In particular, when a cathode ray tube glass cullet is used, the content of the group 2 oxide group can be easily realized within the above range, and the sub-condition 1 of the second composition condition (content of SrO and BaO) 16 mol% or more) and sub-condition 2 (K ₂ O content is 7 mol% or more) can be easily realized. Furthermore, a mixing ratio of Na ₂ O / K ₂ O = 0.80 to 2.0 (molar ratio) in the lower condition 2 can be easily realized. Therefore, it can be judged that the glass fiber comprised from the glass raw material which has these composition conditions was manufactured using the cathode ray tube glass cullet.

In addition to glass cullet, other glass raw materials may be blended as necessary. Examples of other glass raw materials include feldspar, dolomite, soda ash, borax, and the like. Moreover, it does not specifically limit about conditions, such as a particle size of glass cullet.

[Frozen refrigerator]
Next, an example when the vacuum heat insulating material 10 having the above-described configuration is applied to a refrigerator-freezer will be specifically described with reference to FIG.

As shown in FIG. 2, the refrigerator-freezer 20 according to the first embodiment includes an outer box 21, an inner box 22, a cooling unit (not shown), and the like. The outer box 21 is an external housing of the refrigerator-freezer 20, and is a steel plate box made of, for example, a steel plate or a stainless steel plate. The inner box 22 is a resin box that is located in the outer box 21 and is obtained by vacuum molding, for example, ABS resin.

The inside of the inner box 22 is a storage space for storing items such as food. The specific configuration of the storage space is not particularly limited, and is divided into a plurality of storage chambers as appropriate according to the type, application, size, and the like of the refrigerator-freezer 20, and the internal temperature is set. As a typical example, the structure which becomes a refrigerator compartment, an ice making room, a freezer compartment, and a vegetable compartment in order from the top is mentioned. The cooling unit (not shown) includes a compressor, a condenser, an evaporator, and a pipe connecting them, and cools each storage chamber in the inner box 22.

As shown in FIG. 2, the vacuum heat insulating material 10 is disposed in a space formed between the outer box 21 and the inner box 22 (referred to as “heat insulating space” for convenience of explanation). The vacuum heat insulating material 10 may be disposed in any of the heat insulating spaces, but in the present embodiment, it is particularly preferable to be disposed on the left and right side surfaces 20b and the back surface 20c. In FIG. 2, for convenience of explaining the arrangement of the vacuum heat insulating material 10, the vacuum heat insulating material 10 is not illustrated between the outer box 21 and the inner box 22, but is illustrated outside the outer box 21. However, in actuality, it is arranged in a heat insulating space between the outer box 21 and the inner box 22.

Since the heat insulating space is formed on the left and right side surfaces 20b, the back surface 20c, and the top surface 20d of the refrigerator / freezer 20, the vacuum heat insulating material 10 can be disposed in any of the heat insulating spaces on these surfaces. However, since the area of the top surface 20d is smaller than the other surfaces, the heat insulation space is also reduced. The front surface 20a has the same size as the back surface 20c, but a plurality of doors or drawers are provided corresponding to the plurality of storage chambers of the inner box 22, so that a heat insulating space is formed on the entire surface like the back surface 20c or the side surface 20b. Is not formed. Therefore, it is preferable to dispose the vacuum heat insulating material 10 in any one of the both side surfaces 20b and the back surface 20c where a larger heat insulating space is formed, preferably in the heat insulating space of all surfaces.

Unlike the foam type heat insulating material filled in the heat insulating space, the vacuum heat insulating material 10 is molded in advance as a board body as shown in FIG. 1, and its heat insulating performance is superior to that of the foam type. ing. In particular, since the heat insulation of the core material 11 is further reduced, the vacuum heat insulating material 10 can exhibit excellent heat insulating performance even when compared with the conventional vacuum heat insulating material. Therefore, if the vacuum heat insulating material 10 matched to the size of the both side surfaces 20b and the back surface 20c is manufactured and disposed in the heat insulating space of each surface, the majority of the refrigerator-freezer 20 can be well insulated. The refrigeration and freezing function of the freezer 20 can be improved and energy saving can be achieved. Moreover, since the vacuum heat insulating material 10 can suppress aged deterioration of heat insulation performance, even if the refrigerator-freezer 20 is used for a long period of time, deterioration of the refrigeration and freezing function and energy saving performance can also be suppressed.

In the present embodiment, the heat insulating space on the top surface 20d and the door or drawer on the front surface 20a may be filled with foam type heat insulating material, but the vacuum heat insulating material 10 is also disposed on these surfaces. It goes without saying that it may be done. Moreover, the vacuum heat insulating material 10 should just be fixed to at least one of the outer box 21 and the inner box 22 by the well-known method in the heat insulation space.

(Embodiment 2)
Next, an example where the vacuum heat insulating material 10 described in the first embodiment is used for a residential wall will be specifically described with reference to FIG.

As shown in FIG. 3, the residential wall 30 according to the second embodiment includes a load-bearing wall 31, a frame body 32, and a vacuum heat insulating material 10. The load-bearing wall 31 is a wall that has a strength capable of resisting forces from the vertical direction and the horizontal direction when it is provided as a building wall and can support the building. The specific configuration is not particularly limited, and a known configuration can be suitably used. In FIG. 3, for convenience of explanation, it is shown as a single plate member, but the bearing wall 31 may be a panel formed of a pillar material, a bracing material, a plywood material, or the like.

The surface 31 a of the load bearing wall 31 is a wall surface of the building, but the vacuum heat insulating material 10 is fixed to the back surface 31 b of the load bearing wall 31. Therefore, the housing wall 30 according to the present embodiment is a heat insulating panel material in which the load-bearing wall 31 and the vacuum heat insulating material 10 are integrated.

The frame body 32 supports the vacuum heat insulating material 10 by fixing it to the back surface 31 b of the load bearing wall 31, and may have a function of reinforcing the load bearing strength of the load bearing wall 31. The frame body 32 is fixed to the load bearing wall 31 by a nail member 33 inserted from the surface 31 a of the load bearing wall 31. The vacuum heat insulating material 10 is disposed in the frame 32, and a gap between the frame 32 and the vacuum heat insulating material 10 is filled with the caulking material 36.

Furthermore, air-tight materials 34 and 35 are provided on the portion of the back surface 31 b of the load bearing wall 31 that is exposed to the outside of the frame body 32 and the outer peripheral surface of the frame body 32. The airtight members 34 and 35 function to keep the space between the column or beam and the housing wall 30 airtight when the panelized housing wall 30 is fixed to a column or beam of a building. . Specific configurations of the airtight materials 34 and 35 and the caulking material 36 are not particularly limited, and known materials can be suitably used.

As described above, the housing wall 30 according to the present embodiment is fixed in a state where the vacuum heat insulating material 10 described in the first embodiment overlaps most of the load bearing wall 31, and the vacuum heat insulating material 10 has a core. Since the heat conduction of the material 11 is further reduced, excellent heat insulating performance can be exhibited even when compared with the conventional vacuum heat insulating material. Therefore, the entire wall can be further effectively insulated. Moreover, since the vacuum heat insulating material 10 can suppress aged deterioration of the heat insulating performance, the heat insulating property is not easily lowered even when used for a long time as a wall of a house. Therefore, it can be suitably used as a wall of a next-generation energy-saving house.

In addition, the housing wall 30 according to the present embodiment may have a configuration in which the vacuum heat insulating material 10 and the load bearing wall 31 are provided, and the vacuum heat insulating material 10 is disposed on the back surface 31b side of the load bearing wall 31. The frame body 32 and the like may be omitted. Furthermore, although the residential wall 30 according to the present embodiment is panelized to be a “heat insulation panel material”, the specific configuration as the heat insulation panel material is not limited to the configuration disclosed in the present embodiment. The structure of a well-known heat insulation panel material is applicable.

Further, in the present embodiment, the frame body 32 is fixed to the load bearing wall 31 when the housing wall 30 is made into a panel, but the fixing method of the frame body 32 is not limited to the method using the nail member 33, A method using a fixing member other than the nail member 33 may be used, or a method may be used in which a concave portion, a convex portion, or the like is formed in each of the load bearing wall 31 and the frame body 32 and these are combined and fixed.

Furthermore, the housing wall 30 according to the present embodiment does not necessarily have to be panelized as a heat insulating panel material, and the vacuum heat insulating material 10 is fixed to the back surface 31b of the load bearing wall 31 when used as a housing wall. It only has to be done. Therefore, when building a house, the house wall 30 according to the present embodiment can be assembled at any time at the building site.

In addition, the field of application of the vacuum heat insulating material 10 according to the present invention is not limited to the refrigerator-freezer according to the second embodiment or the housing wall according to the third embodiment, and various known ones using heat insulating materials. Needless to say, it can be suitably used in the field.

The present invention will be described more specifically based on examples, comparative examples, and reference examples, but the present invention is not limited thereto. Those skilled in the art can make various changes, modifications, and alterations without departing from the scope of the present invention. In addition, measurement and evaluation of various synthesis reactions and physical properties in the following examples were performed as follows.

(Measurement and evaluation)
[Alkali elution amount]
As described above, an elution test for alkali components of glass fibers was performed based on JIS R3502-1995. When the alkali elution amount was 300 μg / g or less, it was evaluated as “◯”, and when it exceeded 300 μg / g, it was evaluated as “x”.

[Ten point average roughness Rz]
As described above, the ten-point average roughness Rz on the fiber surface of the glass fiber was measured based on JIS B0601-1976 (deleted from JIS B0601-2001).

[Young's modulus of glass material]
As described above, the Young's modulus of the glass material used for the glass fiber was measured based on JIS R1602.

[Thermal conductivity of glass material]
As described above, the thermal conductivity of the glass material used for the glass fiber was measured based on JIS R1611.

[Thermal conductivity of vacuum insulation]
The thermal conductivity of the vacuum heat insulating material 10 was measured based on JIS A1412 (or ASTM518 or ISO8301) as described above. What is necessary is just to measure by the prescribed method. As described above, in order to effectively follow the sensitivity of thermal conductivity, in the following examples, comparative examples, and reference examples, a thermal conductivity measuring device (auto λ) HC-manufactured by Hidehiro Seiki Co., Ltd. A value directly measured by 074-300 (trade name) was used for evaluating the thermal conductivity of the vacuum heat insulating material 10.

Example 1
Hydrophobic glass fibers having an average diameter of 4 μm were produced by a centrifugal fiberizing apparatus using a cathode ray tube glass cullet as a raw material composition. The composition of the obtained hydrophobic glass fiber is shown in Table 1. In Table 1 and Tables 2 and 3 described later, for the purpose of classifying the oxides contained in the glass material, B ₂ O ₃ and Al ₂ O ₃ are collectively referred to as “Group 13 oxide” (Group 13 element). The meaning of oxide). In addition, alkali components, Group 2 oxide groups, and oxides other than Group 13 oxides are collectively described as “other oxides” for convenience.

With respect to the obtained hydrophobic glass fiber, the state of the fiber surface was measured at a spacing of 1.73 μm along the longitudinal direction (longitudinal direction) of the fiber, using a scanning probe microscope (manufactured by Shimadzu Corporation, trade name: SPM-). 9700), as shown in FIG. 4A, the maximum value of the vertical axis, that is, the difference between the lowest concave portion and the highest convex portion of the fiber surface is 57.56 nm, and the difference is 40 within the interval of 1.73 μm. Many irregularities falling within the range of ˜50 nm were confirmed. Moreover, the average height of the fiber surface shown with a dotted line in the figure was 25 nm.

Further, Table 1 shows the results of alkali elution amount and 10-point average roughness of the obtained hydrophobic glass fiber.

Next, the obtained hydrophobic glass fibers were laminated so as to have a predetermined size, and heated and pressed using a metal jig to obtain a core material 11 having a thickness of 10 mm. The obtained core material 11 was dried in a drying furnace at 140 ° C. for 30 minutes.

Also, a bag-like shape is formed by using a laminate film in which a PET film (surface protective layer) having a thickness of 12 μm, an Al foil (intermediate layer) having a thickness of 6 μm, and an LLDPE film (thermal welding layer) having a thickness of 50 μm are laminated. The outer packaging material 12 was molded, and the core material 11 was inserted into the outer packaging material 12.

Thereafter, the pressure is reduced so that the inside of the outer packaging material 12 becomes 10 Pa or less in the decompression chamber, and the opening of the outer packaging material 12 is thermally welded and hermetically sealed, whereby the vacuum heat insulating material 10 according to this embodiment is manufactured. did. Table 1 shows the thermal conductivity of the obtained vacuum heat insulating material 10.

(Comparative Example 1)
A comparative vacuum heat insulating material 1 was manufactured in the same manner as in the above example except that the core material 11 was made of general glass fiber. Table 1 shows the composition of the glass fibers constituting the core material 11.

When the state of the fiber surface of the glass fiber was observed with a scanning probe microscope, as shown in FIG. 4B, the maximum value of the vertical axis was 8.48 nm, and a single large convex portion was present in the interval of 1.74 μm. Except for confirmation, it was almost flat. Moreover, the average height of the fiber surface shown with a dotted line in the figure was 3 nm.

Moreover, while showing the result of the alkali elution amount of glass fiber used for the core material 11, and the 10-point average roughness Rz in Table 1, the result of the thermal conductivity of the obtained comparative vacuum heat insulating material 1 is also shown in Table 1. .

(Contrast of Example 1 and Comparative Example 1)
As shown in Table 1, the vacuum heat insulating material 10 of Example 1 had half the heat conductivity of the comparative vacuum heat insulating material 1 and had excellent heat insulating performance. Moreover, the hydrophobic glass fiber used as the core material 11 has a fiber surface rougher than that of the glass fiber of Comparative Example 1, and the numerical value of the ten-point average roughness Rz is 30 or more. And improved heat insulation performance. Moreover, the hydrophobic glass fiber of the vacuum heat insulating material 10 has a small amount of alkali elution and has a good hydrophobicity (water resistance), so that the heat insulating performance can be stably maintained over a long period of time. It was.

Further, the glass material constituting the hydrophobic glass fiber of Example 1 satisfies the first composition condition, and includes all of MgO, SrO and BaO as the group 2 oxide group, and SrO and BaO. Is 10 mol% or more and satisfies the sub-composition condition, but the glass material of Comparative Example 1 has 9.0 mol% CaO and does not satisfy the first composition condition, and SrO and It did not contain BaO. Furthermore, the content of the alkali component of the glass material of Example 1 is lower than that of Comparative Example 1, and in the glass material of Example 1, Na ₂ O / K ₂ O = 0.80 to 2.0. Although it was in the range, the glass material of Comparative Example 1 had a very large value of Na ₂ O / K ₂ O = 31.

Thus, in the present invention, by satisfying at least the first composition condition, at least (1) the hydrophobic condition and (2) the surface roughness condition can be satisfied among the above-described property conditions.

(Examples 2 to 6)
A cathode ray tube glass cullet is used as a raw material composition, the alkali component and the group 2 oxide group are adjusted so as to satisfy the second composition condition, and B ₂ O ₃ is added. Thus, the core material 11 and the vacuum heat insulating material 10 of Examples 2 to 6 were produced. In addition, Table 2 shows the composition of the glass fibers constituting the core material 11 of each example.

Further, regarding the glass material (bulk material) used for the glass fiber of each example, the Young's modulus was measured and the thermal conductivity was measured. Furthermore, the heat conductivity was measured also about the vacuum heat insulating material 10 of each Example. These results are shown in Table 2.

(Comparative Example 2)
A core material 11 and a comparative vacuum heat insulating material 2 of Comparative Example 2 were produced in the same manner as in Example 1 except that general soda glass cullet was used as the raw material composition. In addition, Table 2 shows the composition of the glass fiber constituting the core material 11 of Comparative Example 2.

Further, regarding the glass material (bulk material) used for the glass fiber of Comparative Example 2, the Young's modulus was measured and the thermal conductivity was measured. Further, the thermal conductivity of the comparative vacuum heat insulating material 2 was also measured. These results are shown in Table 2.

(Contrast of Examples 2 to 6 and Comparative Example 2)
As shown in Table 2, the vacuum heat insulating materials 10 of Examples 2 to 6 had an excellent heat insulating performance because their thermal conductivity was less than half that of the comparative vacuum heat insulating material 2. Further, the glass materials of the glass fibers used in Examples 2 to 6 and Comparative Example 2 were all 71 GPa or more, but the thermal conductivity of Comparative Example 2 exceeded 1.00 W / mK. On the other hand, all of Examples 2 to 6 were less than 1.00 W / mK, and it was revealed that the heat insulating property of the glass fiber itself was excellent.

In addition, the glass materials of Examples 2 to 6 all satisfy the second composition condition (and the first composition condition), and are within the range of Na ₂ O / K ₂ O = 0.80 to 2.0. It was in. On the other hand, Comparative Example 2 does not contain SrO and BaO as in Comparative Example 1, and the contents of K ₂ O and B ₂ O ₃ are reduced, and the second composition condition is not satisfied. It was. Therefore, the glass materials of Examples 2 to 6 were in the range of Na ₂ O / K ₂ O = 0.80 to 2.0, but the glass material of Comparative Example 2 was Na ₂ O / K. _The value was very large at ₂ O = 11.71.

Thus, in the present invention, by satisfying the second composition condition, among the above-mentioned property conditions, at least (3) the rigidity condition can be satisfied, and excellent heat insulation can be exhibited. Further, since the total amount of alkali components in Examples 2 to 6 is smaller than the total amount of alkali components in Comparative Example 2, (1) hydrophobic conditions can be realized.

(Reference Examples 1 and 2)
Although the cathode ray tube glass cullet is used as the raw material composition, the core material 11 and the reference vacuum heat insulating material of Reference Examples 1 and 2 are produced in the same manner as in Examples 2 to 6 except that B ₂ O ₃ is not added. did. In addition, Table 3 shows the composition of the glass fibers constituting the core material 11 of each reference example.

Further, regarding the glass material (bulk material) used for the glass fiber of each reference example, the Young's modulus was measured and the thermal conductivity was measured. Furthermore, the thermal conductivity of the reference vacuum heat insulating material of each reference example was also measured. These results are shown in Table 3.

(Contrast of Examples 1 to 6 and Reference Examples 1 and 2)
Since Reference Examples 1 and 2 satisfy the first composition condition and the sub-composition condition, they correspond to Examples in the present invention, but are positioned here as examples for comparison with Examples 2 to 6. Therefore, it is handled as a “reference example”.

The reference vacuum heat insulating materials of these reference examples have the thermal conductivity equivalent to that of Example 1, and the thermal conductivity of the glass material also shows a value equivalent to or lower than that of Examples 2 to 6. ing. Therefore, it can be seen that good heat insulation can be realized if the first composition condition and the sub-composition condition are satisfied. However, when the second composition condition is not satisfied (in Reference Examples 1 and 2, the lower condition 3 is not satisfied), the Young's modulus of the glass material is less than 71 GPa. It can be seen that the rigidity condition cannot be satisfied.

It should be noted that many improvements and other embodiments of the present invention will be apparent to those skilled in the art from the above description. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

Since the present invention can exhibit excellent heat insulation by reducing the heat conduction of the core material, it can be widely used in various fields for the purpose of heat insulation, and in particular, further energy saving such as a refrigerator-freezer, a housing wall, etc. It can be suitably used in a field that needs to be realized.

DESCRIPTION OF SYMBOLS 10 Vacuum heat insulating material 11 Core material 12 Outer packaging material 20 Refrigerating refrigerator 20b (Frozen refrigerator) side surface 20c (Frozen refrigerator) back surface 21 Outer box 22 Inner box 30 Residential wall 31 Load bearing wall 31b (Load bearing wall) back surface

Claims

A heat-insulating core material;
An outer packaging material having a gas barrier property and enclosing the core material in a sealed state under reduced pressure,
The core material is
At least the CaO content is 5 mol% or less and has hydrophobicity,
The ten-point average roughness Rz of the fiber surface is 30 or more,
SrO and BaO content is 16 mol% or more, and K 2 O content 7 mol% or more and the content of B 2 O 3 is 4 mol% or more,
Composed of glass fiber,
Vacuum insulation.
A heat-insulating core material;
An outer packaging material having a gas barrier property and enclosing the core material in a sealed state under reduced pressure,
The core material is composed of glass fibers having at least a CaO content of 5 mol% or less and having hydrophobicity,
Vacuum insulation.
A heat-insulating core material;
An outer packaging material having a gas barrier property and enclosing the core material in a sealed state under reduced pressure,
The core material is composed of glass fibers having a ten-point average roughness Rz of 30 or more on the fiber surface.
Vacuum insulation.
A heat-insulating core material;
An outer packaging material having a gas barrier property and enclosing the core material in a sealed state under reduced pressure,
The core material, SrO and BaO content is 16 mol% or more, and K 2 O content 7 mol% or more, and a glass fiber content of B 2 O 3 is 4 mol% or more It is configured,
Vacuum insulation.
The glass fiber has an alkali elution amount based on JIS R3502 of 300 μg / g or less.
The vacuum heat insulating material according to claim 2.
The glass fiber has an average diameter in the range of 0.1 to 10 μm,
The core material is configured to orient the glass fibers in a direction intersecting the heat transfer direction,
The vacuum heat insulating material according to claim 3.
The glass fiber contains at least one of SrO, BaO, and MgO.
The vacuum heat insulating material according to claim 2 or 3.
The glass fiber is
When it contains SrO, its content is in the range of 1 to 12 mol%,
When it contains BaO, its content is in the range of 1 to 8 mol%,
When it contains MgO, its content is in the range of 5 to 12 mol%,
The vacuum heat insulating material according to claim 7.
The Young's modulus of the glass material constituting the glass fiber is 71 GPa or more.
The vacuum heat insulating material according to claim 4.
The core has a porosity of 90% or more.
The vacuum heat insulating material of any one of Claim 1 to 9.
The thermal conductivity of the glass material constituting the glass fiber is 1 W / mK or less,
The vacuum heat insulating material according to any one of claims 1 to 10.
The glass fiber is manufactured using CRT glass as its raw material,
The vacuum heat insulating material according to any one of claims 1 to 11.
The vacuum heat insulating material according to any one of claims 1 to 12,
An outer box as an external housing;
An inner box located in the outer box, the inside of which is a storage space for storing articles,
The vacuum heat insulating material is arranged between the outer box and the inner box,
Freezer refrigerator.
The vacuum heat insulating material is disposed between the outer box and the inner box at a position that is at least one of the left and right side surfaces and the back surface of the refrigerator-freezer.
The refrigerator-freezer of Claim 13.
The vacuum heat insulating material according to any one of claims 1 to 12,
Bearing walls, and
The vacuum heat insulating material is disposed on the back side of the load bearing wall,
Residential wall.
The heat insulating panel material is configured by fixing the vacuum heat insulating material to the back surface of the load bearing wall.
The residential wall according to claim 15.