JP2007057095A - Vacuum heat insulating material and heat insulating material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance insulation efficiency by increasing strength of a work piece of a glass fiber employed in a core material of a vacuum heat insulating material, restraining the core material from being highly densified by atmospheric air compression and reducing heat conduction of a solid ingredient in a core material portion. <P>SOLUTION: The vacuum heat insulating material 1 is configured so as to enclose to deflate inside of a sheathed material 4 by covering the core material 2 comprising the glass fiber and a moisture adsorption material 3 by the sheath material 4 including gas barrier properties. The glass fiber consists a glass composition which is composed of SiO<SB>2</SB>of 45-75%, AL<SB>2</SB>O<SB>3</SB>of 0-25%, B<SB>2</SB>O<SB>3</SB>of 0-12%, Na<SB>2</SB>O of 0-20%, K<SB>2</SB>O of 0-3%, MgO of 0-15%, CaO of 11-30% and other composition of 3% or less, by weight fraction, respectively and furthermore, wherein the sum total of these compositions by weight fraction amounts to 100%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vacuum heat insulating material and a heat insulating material.

  In recent years, energy saving has been desired for the purpose of preventing global warming, and energy saving has been promoted for consumer devices. In particular, with respect to a refrigerator-freezer, a heat insulating material having excellent heat insulating properties is required from the viewpoint of efficiently using cold heat.

  As a general heat insulating material, a fiber body such as glass wool or a foam body such as urethane foam is used. However, it is necessary to increase the thickness of the heat insulating material in order to improve the heat insulating properties of these heat insulating materials. Therefore, when there is a limit to the space where the heat insulating material can be installed, or when space saving or effective use of the space is necessary, the conventional heat insulating material is not desirable.

  As a means for solving such a problem, there are a core material made of a porous body and a vacuum heat insulating material configured by covering the core material with an outer packaging material and sealing the inside under reduced pressure. In recent years, vacuum heat insulating materials that are further superior in heat insulating performance have been demanded in the face of intensifying competition for energy saving in recent years.

  In general, heat transfer of a heat insulating material is caused by heat conduction, radiation, and convective heat transfer between a solid and a gas component. On the other hand, the vacuum heat insulating material formed by reducing the pressure inside the outer packaging material has little effect on the heat conduction and convective heat transfer of the gas component. In addition, there is almost no contribution of radiation when used in a temperature range below room temperature.

  Therefore, it is important to suppress the heat conduction of the solid component in the vacuum heat insulating material applied to a cold insulation device used at room temperature or lower. Therefore, various fiber materials have been reported as a core material for vacuum heat insulating materials having excellent heat insulating performance.

  For example, glass fibers, ceramic fibers, slag wool fibers, rock wool fibers, etc. are used as the core material, and the average fiber length is 1 mm or less and the average fiber diameter is 0.5 to 3 μm. A vacuum heat insulating material oriented in a direction perpendicular to the thickness direction of the plate-like core material has been proposed (see, for example, Patent Document 1).

With this configuration, in the core part of a general plate-like or sheet-like vacuum heat insulating material, heat conduction of a solid component that heat is transmitted through one fiber in the thickness direction of the vacuum heat insulating material is not Since heat is transferred to adjacent fibers one after another through contact points between the fibers, heat conduction is made between the fibers in contact with each other in the thickness direction of the core material. Therefore, since the contact thermal resistance between fibers exists, heat transfer in the core portion is suppressed particularly in the thickness direction as compared with a core material in which one fiber directly transfers heat in the heat transfer direction. Here, the vacuum heat insulating material is a plate having a flat surface or a curved surface, or a sheet. The direction of heat insulation is synonymous with the thickness direction.
Japanese Patent Laid-Open No. 9-4785

  However, in the above-mentioned conventional configuration, it is assumed that general-purpose inorganic fibers are used as they are for the core material of the vacuum heat insulating material. Just by optimizing the fiber shape, as the vacuum heat insulating material, the heat transfer of the core material portion is no more. Could not be suppressed.

  For example, as a general-purpose glass fiber, a glass fiber having a glass structure with a weak molecular bond is generally used, and its strength is about 70 to 75 GPa when expressed in terms of the material Young's modulus.

  When producing a plate-like or sheet-like vacuum heat insulating material using such a fiber laminate made of low-strength glass as a core material, the core material part is particularly in the thickness direction because the larger surface receives atmospheric compressive stress. Since the core material is highly densified, the number of contacts between the laminated fibers increases. As a result, there has been a problem that the heat transfer path of the core portion increases particularly in the thickness direction.

  In addition, since ceramic fibers are high in strength, it is possible to suppress the densification of the core material part even during atmospheric compression and increase the heat insulation performance, but the material cost is high and the production for fiberization Since the cost is extremely high, it is not preferable as a fiber used for a general-purpose heat insulating material.

  Moreover, in slag wool and rock wool, the intensity | strength was still lower than a general purpose glass fiber, and there existed a subject that the heat insulation performance of a vacuum heat insulating material will fall similarly by densification of a core material part.

  The present invention solves the above-mentioned conventional problems, suppresses heat transfer in the core part, dramatically improves the heat insulating performance of the vacuum heat insulating material, and reduces the manufacturing cost, and is highly versatile vacuum heat insulating. The purpose is to provide materials. Furthermore, the mechanical strength and durability of the inorganic fiber applied to the core material are improved, and the core material itself is intended to provide a vacuum heat insulating material that is also useful as a heat insulating material for building materials under atmospheric pressure.

In order to achieve the above object, the vacuum heat insulating material of the present invention is formed by covering a core material made of glass fiber with an outer packaging material having a gas barrier property, and sealing the inside of the outer packaging material under reduced pressure. in weight% SiO ₂ is 45 to 75% Al ₂ O ₃ is 0 to 25% B ₂ O ₃ is 0 to 12% Na ₂ O is 0 to 20% K ₂ O is 0-3%, MgO is 0 to 15%, CaO is 11 to 30%, other composition is 3% or less, and the total weight percentage of these compositions is 100%. And

  Thereby, the component of the glass fiber used for a core material can raise glass raw material intensity | strength by reducing an alkali metal oxide from the general glass wool used for the conventional core material. As a result, in the laminated body of glass fibers, the repulsive force against the overall compressive stress is increased, so that it is possible to suppress the increase in density in the thickness direction even during compression, and to prevent an increase in the number of contacts. it can. Furthermore, by increasing the material strength, it is possible to increase the surface hardness, to reduce the deformation of the contact points between the glass fibers, and to reduce the contact area. Therefore, even during atmospheric compression, the core material has few heat transfer paths in the thickness direction due to the core material solid, and the thermal resistance increases.

  The vacuum heat insulating material of the present invention dramatically improves the heat insulating performance by reducing the heat conduction of the solid component in the core material portion. Therefore, since a high heat insulation effect is obtained by conventional production without changing the quality state such as fiber length, fiber diameter, and lamination state, the production is easy.

  It can be said that it is a remarkable progress to improve the heat insulating performance of the vacuum heat insulating material by controlling the strength of the inorganic material such as glass, which is originally treated as a hard material, to make the fiber harder.

  In addition, these glass fibers have mechanical strength and durability as compared with general-purpose glass wool, and therefore are easy to handle and have little deterioration over a long period of time. Therefore, these glass fibers are useful as general glass wool for building materials and reinforcing materials.

The invention of the vacuum heat insulating material according to claim 1 is formed by covering a core material made of glass fiber with an outer packaging material having a gas barrier property, and sealing the inside of the outer packaging material under reduced pressure. SiO ₂ is 45 to 75%, Al ₂ O ₃ is 0 to 25%, B ₂ O ₃ is 0 to 12%, Na ₂ O is 0 to 20%, K ₂ O is 0 to 3%, MgO is 0 -15%, CaO 11-30%, other composition 3% or less, and consisting of a glass composition constituted such that the total of the weight% of these compositions is 100%.

  As a result, the core material has more alkaline earth metal oxides than the conventional glass wool composition, and the material strength is improved by increasing the ion packing density of the glass molecular structure, and the core material has a higher density during atmospheric compression. Therefore, the increase in the indirect point of the fiber in the thickness direction and the increase in the contact area can be suppressed, so that the heat transfer path in the core material solid can be reduced and a high heat resistance core material can be obtained.

  By the above effect | action, the heat conduction of the solid component in the core material part of a vacuum heat insulating material is suppressed, and heat insulation performance improves.

The invention of the vacuum heat insulating material according to claim 2 is formed by covering a core material made of glass fiber with an outer packaging material having a gas barrier property, and sealing the inside of the outer packaging material under reduced pressure. SiO ₂ is 50 to 65%, Al ₂ O ₃ is 0 to 18%, B ₂ O ₃ is 2 to 10%, Na ₂ O is 0 to 20%, K ₂ O is 0 to 3%, MgO is 0 10%, CaO is 11 to 23%, the other composition is 3% or less, and the total weight percent of these compositions is 100%.

Thus, the core material is added to the action according to claim 1, Al ₂ O ₃ is high meltability by reducing, no devitrification problems during glass production. Furthermore, it is possible to manufacture using an inexpensive material.

  With the above operation, high-strength and inexpensive glass can be obtained, so that the productivity of the vacuum heat insulating material is improved and versatility is enhanced.

  The invention for a vacuum heat insulating material according to claim 3 is the invention according to claim 1 or 2, and includes at least one kind of alkali metal oxide and alkaline earth metal oxide, and the alkali metal oxide. The numerical value of the total weight% of the components of the alkaline earth metal oxide is larger than the numerical value of the total weight% of the components.

  Whereas alkali metal oxides serve to weaken the bond strength in the glass structure, alkaline earth metal oxides act to increase the ion packing density of the glass and improve the material strength of the glass.

  Therefore, since the glass composition of the present invention increases the strength of the material by increasing the weight percent of the alkaline earth metal, the densification of the core material during atmospheric compression is prevented, and the increase of fiber indirect points in the thickness direction, And since the increase in contact area can be suppressed, the heat transfer path in the core material solid can be made small, and a high heat resistance core material can be obtained.

  By the above effect | action, the solid heat conduction in a core material part is further suppressed and the heat insulation performance of a vacuum heat insulating material improves.

  The invention of the vacuum heat insulating material according to claim 4 is the invention according to any one of claims 1 to 3, wherein the total amount of the alkali metal oxide and the alkaline earth metal oxide in the glass component is% by weight. Is in the range of 20% to 45%.

  By containing a predetermined amount of an alkali metal oxide and an alkaline earth metal oxide in the glass component, the viscosity of the glass is lowered, so that the meltability is improved.

  By the above operation, the core material of the vacuum heat insulating material can reduce the heat energy required at the time of manufacture, and the productivity is increased.

  Invention of Claim 5 is a heat insulating material which consists of a core material of the vacuum heat insulating material of the invention as described in any one of Claim 1 to 4.

  Therefore, this heat insulating material is constituted by using an inexpensive material, has high glass material strength, and has good meltability. Further, since the ion packing density is high and the structure is stable, the durability is high.

  Due to the above action, the heat insulating material in the present invention is extremely stable even when used alone as a glass, and since it is obtained at a low cost with a high strength, it is less deteriorated over a long period of time than conventional glass wool, resulting in a high mechanical strength. It is useful as an excellent general-purpose heat insulating material.

In addition, the glass that can be used in the present invention may be a fiber made of a glass-forming oxide that can be in a glass state. However, when considering versatility and environmental aspects in particular, a silicate system mainly containing SiO _2. Borosilicate glass is preferred.

When the SiO ₂ content is decreased in terms of weight percent in each component, devitrification becomes a problem, and it becomes difficult to produce glass. When the SiO ₂ content is increased, the viscosity is increased and the productivity is lowered. Although a range is good, More preferably, it is the range of 50 to 65%, More preferably, it is the range of 55 to 65%.

When Al ₂ O ₃ increases, the viscosity becomes extremely high, so that it is preferably 25% or less, more preferably 18% or less in terms of production. Moreover, there exists an effect which suppresses devitrification by adding a trace amount, and the range of 0.1-3.5% is further more preferable.

If too much B ₂ O ₃ is used, the damage to the furnace wall due to volatile components increases during production, so 12% or less is preferable. However, in order to improve the meltability and durability, it is desirable to contain a small amount, more preferably Is in the range of 2% to 10%, more preferably in the range of 2% to 8%.

If Na ₂ O exceeds 20%, the strength of the material decreases, so 20% or less is preferable. More preferably, 3% or more and 13% or less including an appropriate amount of Na ₂ O for improving meltability and devitrification. More preferably, it is the range of 5% or more and 13% or less.

Since K ₂ O has a high material cost, it is not necessary to add K ₂ O actively. Increasing MgO improves material strength and durability, but material devitrification deteriorates, so 15% or less is preferable, more preferably 10% or less, and even more preferably 2 to 8%. .

  CaO increases the strength and durability of the material in the same manner as MgO and has a low material cost. However, if it exceeds 30%, it causes devitrification, so it is greater than 11% and preferably less than 30%, more preferably 11 % And not more than 23%, and more preferably not less than 11% and not more than 20%.

In addition, when glass cannot be stably produced due to an increase in the content of alkaline earth metal oxide, etc., the transparency can be improved by adding components such as TiO ₂ , ZrO ₂ , ZnO, Productivity can also be increased. Further, when a small amount of P ₂ O ₅ having particularly low viscosity characteristics is added, the productivity is further increased.

  If the total of the other components is less than 3% by weight, there is almost no influence on the whole glass, and natural raw materials containing impurities can be used as raw materials.

Moreover, it is preferable to use a refining agent at the time of manufacturing the glass in order to improve the bubble breakage and improve the productivity, and known materials such as Sb ₂ O ₃ can be applied.

  Moreover, a moisture adsorbent can be used for the vacuum heat insulating material of the present invention. The moisture adsorbing material is not particularly limited as long as it adsorbs water vapor existing inside the vacuum heat insulating material and reduces the amount of water vapor in the internal atmosphere.

  Examples include physical adsorbents such as synthetic zeolite, activated carbon, activated alumina, silica gel, dawsonite, hydrotalcite, and chemical adsorbents such as alkali metals and alkaline earth metals alone and their oxides and hydroxides. It is. Furthermore, by using together a getter material or the like that can adsorb an air component, it is possible to reduce the heat conduction of the internal gas component and improve the heat insulation performance.

  In addition, a plastic laminate film can be used as the outer packaging material of the present invention, but a metal foil or a vapor deposition layer can be applied in order to impart higher gas barrier properties. In addition, a metal foil and a vapor deposition layer can use a well-known thing, and it does not specify it in particular.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a cross-sectional view of a vacuum heat insulating material according to Embodiment 1 of the present invention.

  In FIG. 1, a vacuum heat insulating material 1 is configured by inserting a core material 2 and a moisture adsorbing material 3 into an outer packaging material 4 and reducing the pressure inside.

  The vacuum heat insulating material 1 is produced by drying the core material 2 in a drying furnace at 140 ° C. for 30 minutes, and then inserting the three sides of the laminate film into the outer packaging material 4 formed into a bag shape by heat sealing. Thus, the pressure is reduced so that the inside of the outer packaging material 4 becomes 10 Pa or less, and the opening is hermetically sealed by heat welding.

  At this time, the outer packaging material 4 is composed of a laminate film composed of a polyethylene terephthalate film (12 μm) as a surface protective layer, an aluminum foil (6 μm) as an intermediate layer, and a linear low-density polyethylene film (50 μm) as a heat welding layer. ing.

  Further, calcium oxide is applied to the moisture adsorbing material 3. Although there is no particular problem even when the moisture adsorbing material 3 is not provided, the provision of the moisture adsorbing material not only can further reduce the possibility that glass fiber will be eroded by moisture by adsorbing the residual water vapor inside, but the end face. The increase in internal pressure due to water vapor intrusion from can be suppressed over a long period of time. Furthermore, by using a gas adsorbent in combination, the internal pressure can be further reduced and the heat insulation performance can be improved.

On the other hand, the core material 2 is a board-shaped member that is heated in a state where a glass fiber aggregate having an average fiber diameter of 3.5 μm is pressurized and maintains a shape with a density of about 200 kg / m ³ . The average fiber diameter is preferably in the range of 1 μm to 20 μm, and the average fiber diameter of 2 μm to 10 μm has more rigidity as the core material 2 and is more preferable in terms of productivity and thermal conductivity.

Further, the core part bulk density after sealing in terms of thermal insulation performance and handling properties and more preferably in the range of ^{210kg / m 3 ~280kg / m 3} , was made as a this range. The core material bulk density is calculated from the weight of the core material alone and the size after sealing.

  Here, the core material is formed without using a binder, but the core material 2 may be formed at a lower temperature using a binder. If the surface property does not matter, the glass fiber aggregate may be hermetically sealed as it is. In that case, since the number of manufacturing steps is reduced, productivity is improved.

  Moreover, although the concrete content of the used glass composition is demonstrated in detail in an Example, after making the glass in this invention into fiber and laminating | stacking and producing as the core material 2, it is the outer packaging material 4 which reduced the inside. Sealing was performed to obtain a vacuum heat insulating material 1.

  The thermal conductivity of the vacuum heat insulating material 1 formed as described above was measured with an auto lambda manufactured by Eihiro Seiki. As a result, as shown in Examples 1 to 11, the thermal conductivity of the vacuum heat insulating material is 0.0013 W / mK to 0.0019 W / mK at an average temperature of 24 ° C., which is 10 times that of a general-purpose rigid urethane foam. As mentioned above, it had the heat insulation performance far superior even if compared with the conventional vacuum heat insulating material. Moreover, the compressive strength of the glass wool used for the core material is significantly higher than that of the conventional general-purpose glass wool of Comparative Example 1, and the core material is densified even after air compression as a vacuum heat insulating material by improving the strength of the glass material. Therefore, it can be considered that an increase in the number of contacts and an increase in contact area in the thickness direction are suppressed.

  Therefore, the heat conduction of the solid component in the thickness direction in the core portion that has conventionally occupied the majority of the heat transfer element of the vacuum heat insulating material can be suppressed, and the heat insulating performance of the vacuum heat insulating material is greatly improved.

  The material strength of the glass was measured by Young's modulus as an evaluation index. Regarding the Young's modulus, glass processed into a cube having a side of about 3 mm was measured by the resonance method, but may be measured by other methods such as a pulse propagation method. In addition, for the evaluation of the industrial productivity of glass, three items were evaluated: furnace wall erosion damage of manufacturing equipment, temperature of 1000P (Poise) viscosity related to meltability, and devitrification during glass manufacturing. did. Regarding Examples 1 to 11, each result is not particularly about damage to the furnace wall, and all temperatures at which the viscosity becomes 1000P are within 1150 ° C., and devitrification did not occur, so productivity does not matter. It was.

Although Fe ₂ O ₃ is easy to be mixed as an impurity, it does not cause a problem in particular, and it has an effect of absorbing radiant heat. Therefore, for applications in a temperature range of 50 ° C. or more where radiation contributes greatly. Useful.

  In addition, a vacuum heat insulating material has the shape of a plate shape and a sheet shape, and shows the heat insulation member which uses the thickness direction for the purpose of heat insulation. Moreover, what is necessary is just to have a plate-shaped and sheet-like shape partially, and the thing bent and curved is also included.

(Embodiment 2)
A heat insulating material made of glass wool in Embodiment 2 of the present invention will be described. Each glass composition was formed into a fiber state.

  The melt made of the glass composition of the present invention was fiberized so that the average fiber diameter was about 3.5 μm. Regarding the fiberizing step, continuous spinning may be used as long fibers, or flame method, centrifugal method, etc. may be used as short fibers, but glass wool was produced by a centrifugal method in consideration of productivity. A long fiber such as a chop strand mat or a roving cloth can be produced and then processed to be used as a heat insulating material.

The glass wool thus produced was compressed in the thickness direction, and the compression strength was measured when the density was 250 kg / m ³ .

  As a result, the compressive strength of the glass wool made of the glass composition according to the present invention was 1020 hPa or more, indicating a higher compressive strength than the conventional general-purpose glass wool. This is because increasing the alkaline earth metal oxide in the glass component increases the ion packing density of the glass molecular structure and increases the strength of the glass material itself.

  Therefore, by using glass wool with a glass composition having higher material strength than the conventional one, the glass wool has high compressive strength and is useful as a heat insulating material or reinforcing material for building materials and has good handling properties. ) Can be provided.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited only to the Examples.

Example 1
In this example, in terms of% by weight of the glass composition, SiO ₂ is 60.7%, Al ₂ O ₃ is 1.7%, B ₂ O ₃ is 7.0%, Na ₂ O is 10.4%, K ₂ A glass composed of 0.9% O, 4.7% MgO, 13.2% CaO, and 1.4% of the total of other components such as Fe ₂ O ₃ was produced. 4 GPa. The temperature at which the temperature became 1000 P was 1030 ° C., and damage to the furnace wall and devitrification of the glass were not observed, so there was no problem in productivity.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1370 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 236 kg / m ³ and the thermal conductivity was 0.0015 W / mK.

(Example 2)
In this example, SiO ₂ is 64.3%, Al ₂ O ₃ is 0.2%, B ₂ O ₃ is 3.0%, Na ₂ O is 5.2%, and K _{2 in} terms of weight percent of the glass composition. O is 0.8%, MgO is 4.9%, CaO is 19.8%, ZrO ₂ , ZnO, TiO ₂ , P ₂ O ₅ , Fe ₂ O _3, etc. A glass having a material Young's modulus of 88.1 GPa was produced. The temperature at which the temperature became 1000 P was 1065 ° C., and no damage to the furnace wall and glass devitrification were observed, so there was no problem in productivity.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1465 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 230 kg / m ³ and the thermal conductivity was 0.0014 W / mK.

(Example 3)
In this example, the weight percentage of the glass composition is 59.8% SiO ₂ , 1.0% Al ₂ O ₃ , 2.0% B ₂ O ₃ , 5.3% Na ₂ O, K ₂ A glass composed of 1.1% O, 9.9% MgO, 20.1% CaO, and a total of 0.8% of other plural components such as Fe ₂ O ₃ was prepared. It was 9 GPa. The temperature at which the temperature became 1000 P was 1058 ° C., and damage to the furnace wall and devitrification of the glass were not observed, so there was no problem in productivity.

  The compression strength when this glass was laminated after fiberization to form glass wool was 1480 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 228 kg / m ³ , and the thermal conductivity was 0.0014 W / mK.

Example 4
In this example, SiO ₂ is 58.4%, Al ₂ O ₃ is 1.7%, B ₂ O ₃ is 5.9%, Na ₂ O is 10.5%, K ₂ , in terms of% by weight of the glass composition. A glass composed of 0.5% of O, 6.1% of MgO, 16.1% of CaO, and 0.8% of the total of other components such as Fe ₂ O ₃ is produced. 0 GPa. The temperature at which the temperature became 1000 P was 1041 ° C., and damage to the furnace wall and devitrification of the glass were not observed, so there was no problem in productivity.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1120 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 241 kg / m ³ and the thermal conductivity was 0.0017 W / mK.

(Example 5)
In this example, SiO ₂ is 53.8%, Al ₂ O ₃ is 14.9%, B ₂ O ₃ is 8.5%, Na ₂ O is 0.5%, and K _{2 in} terms of% by weight of the glass composition. A glass composed of 0.3% O, 4.6% MgO, 16.6% CaO, and 0.8% of the total of other components such as Fe ₂ O ₃ was produced. It was 8 GPa. The temperature at which the temperature became 1000 P was 1059 ° C., and no damage to the furnace wall and glass devitrification were observed, so there was no problem in productivity.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1415 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 233 kg / m ³ and the thermal conductivity was 0.0015 W / mK.

(Example 6)
In this example, SiO ₂ is 56.0%, Al ₂ O ₃ is 5.0%, B ₂ O ₃ is 7.0%, Na ₂ O is 13.0%, K ₂ , in terms of% by weight of the glass composition. A glass composed of 0.5% O, 3.4% MgO, 15.0% CaO, and 0.1% of the total of other components such as Fe ₂ O ₃ is produced. 0 GPa. The temperature at which the temperature became 1000 P was 1045 ° C., and damage to the furnace wall and devitrification of the glass were not observed, so there was no problem in productivity.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1040 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 246 kg / m ³ and the thermal conductivity was 0.0019 W / mK.

(Example 7)
In this example, SiO ₂ was 46.4%, Al ₂ O ₃ was 8.0%, B ₂ O ₃ was 4.0%, Na ₂ O was 19.5%, and K ₂ , in terms of% by weight of the glass composition. A glass composed of 0.5% O, 3.5% MgO, 18.0% CaO, and 0.1% of the total of other components such as Fe ₂ O ₃ is produced. 0 GPa. The temperature at which the temperature became 1000 P was 1026 ° C., and damage to the furnace wall and devitrification of the glass were not observed, so there was no problem in productivity.

  The compression strength when this glass was laminated after fiberizing into glass wool was 1060 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 245 kg / m ³ and the thermal conductivity was 0.0019 W / mK.

(Example 8)
In this example, SiO ₂ was 65.0%, Al ₂ O ₃ was 0.1%, B ₂ O ₃ was 12.0%, Na ₂ O was 5.0%, and K _{2 in} terms of weight percent of the glass composition. A glass composed of 3.0% O, 2.0% MgO, 11.1% CaO, and a total of 1.8% of other plural components such as Fe ₂ O ₃ was produced. 4 GPa. The temperature at which the temperature became 1000 P was 1052 ° C., and no damage to the furnace wall and glass devitrification were observed, so there was no problem in productivity.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1470 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 228 kg / m ³ , and the thermal conductivity was 0.0014 W / mK.

Example 9
In this example, SiO ₂ is 55.0%, Al ₂ O ₃ is 3.5%, B ₂ O ₃ is 10.0%, Na ₂ O is 3.0%, MgO is 5% by weight of the glass composition. A glass composed of 8.0%, CaO 20.0%, and a total of other components such as Fe ₂ O ₃ of 0.5% was produced, and the material Young's modulus was 89.2 GPa. The temperature at which the temperature became 1000 P was 996 ° C., and there was no problem in productivity because damage to the furnace wall and devitrification of the glass were not observed.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1470 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 230 kg / m ³ and the thermal conductivity was 0.0014 W / mK.

(Example 10)
In this example, SiO ₂ is 46.9%, Al ₂ O ₃ is 9.0%, B ₂ O ₃ is 8.0%, K ₂ O is 0.1%, MgO is 4% by weight of the glass composition. A glass composed of 10.0%, CaO 23.0%, and other components such as Fe ₂ O ₃ totaling 3.0% was produced, and the material Young's modulus was 91.0 GPa. The temperature at which the temperature became 1000 P was 1083 ° C., and no damage to the furnace wall and glass devitrification were observed, so there was no problem in productivity.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1485 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 226 kg / m ³ , and the thermal conductivity was 0.0013 W / mK.

(Example 11)
In this example, SiO ₂ was 45.0%, Al ₂ O ₃ was 1.8%, Na ₂ O was 20.0%, K ₂ O was 2.9%, and CaO was 11% by weight% of the glass composition. A glass having a total of 2.6% of other components such as 0.5% and Fe ₂ O ₃ was produced, and the material Young's modulus was 77.6 GPa. The temperature at which the temperature became 1000 P was 1102 ° C., and no damage to the furnace wall and glass devitrification were observed, so there was no problem in productivity.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1045 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 247 kg / m ³ and the thermal conductivity was 0.0019 W / mK.

(Comparative Example 1)
This comparative example is a general glass wool, in which the SiO ₂ is 63.6%, the Al ₂ O ₃ is 1.7%, the B ₂ O ₃ is 4.0%, and the Na ₂ O is 5% by weight of the glass composition. 14.5%, K ₂ O 0.8%, MgO 3.8%, CaO 10.0%, and other multiple components such as Fe ₂ O ₃ total 1.6% glass, The material Young's modulus was 75.0 GPa.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1010 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 250 kg / m ³ and the thermal conductivity was 0.0022 W / mK.

  In general glass wool, the strength of the glass was weak, and desirable heat insulation performance could not be obtained as compared with Examples.

(Comparative Example 2)
In this comparative example, SiO ₂ is 45.6%, Al ₂ O ₃ is 25.7%, Na ₂ O is 15.8%, K ₂ O is 0.7%, and CaO is 12% by weight in the glass composition. Tried to make a glass composed of 0.1% of other components such as 0.1% Fe ₂ O ₃ , but the melting temperature became too high because Al ₂ O ₃ exceeded 25%. Glass fiber production was not possible.

(Comparative Example 3)
In this comparative example, SiO ₂ is 63.7%, Al ₂ O ₃ is 0.2%, B ₂ O ₃ is 13.2%, Na ₂ O is 5.3%, and K _{2 in} terms of% by weight of the glass composition. A glass comprising 2.9% O, 2.0% MgO, 11.2% CaO, and a total of other components such as Fe ₂ O ₃ of 1.5% is produced, and the material Young's modulus is 82. 2 GPa.

Although this glass has higher material strength than the general glass wool composition described in Comparative Example 1, the erosion damage to the furnace wall in the glass melting equipment is large because B ₂ O ₃ exceeds 12%. Production was impossible.

(Comparative Example 4)
In this comparative example, SiO ₂ is 45.9%, Al ₂ O ₃ is 18.1%, Na ₂ O is 20.5%, K ₂ O is 3.0%, and CaO is 11% by weight% of the glass composition. A glass composed of 1.1% of a total of other components such as 0.4% and Fe ₂ O ₃ was produced, and the material Young's modulus was 74.8 GPa.

  When this glass was laminated after fiberization to obtain glass wool, the compressive strength was 1010 hPa.

Further, when a vacuum heat insulating material was produced using this glass wool as a core material, the bulk density of the core material portion was 252 kg / m ³ and the thermal conductivity was 0.0022 W / mK.

Even when compared with the general glass wool of Comparative Example 1, when Na ₂ O exceeded 20%, the strength of the glass was not improved, and the desired heat insulation performance could not be obtained.

(Comparative Example 5)
In this comparative example, SiO ₂ is 52.7%, Al ₂ O ₃ is 2.2%, B ₂ O ₃ is 4.8%, Na ₂ O is 6.4%, K _{2 in} terms of% by weight of the glass composition. Attempts were made to make glass with 0.8% Og, 15.9% MgO, 17.0% CaO, and 0.2% total of other components such as Fe ₂ O ₃ , but MgO exceeded 15% As a result, devitrification was likely to occur, and it was impossible to produce glass.

(Comparative Example 6)
In this comparative example, SiO ₂ is 52.7%, Al ₂ O ₃ is 2.2%, B ₂ O ₃ is 4.8%, Na ₂ O is 6.4%, K _{2 in} terms of% by weight of the glass composition. Attempts were made to make glass with 0.8% O, 15.9% MgO, 17.0% CaO, and 0.2% total of other components such as Fe ₂ O ₃ , but CaO exceeded 30%. As a result, devitrification was likely to occur, and it was impossible to produce glass.

  The results of Examples 1 to 11 and Comparative Examples 1 to 6 are summarized in (Table 1) and (Table 2).

  As mentioned above, the vacuum heat insulating material and heat insulating material concerning this invention improve the raw material intensity | strength of glass, and have the heat insulation performance superior to the past.

  As a result, the vacuum heat insulating material can be used not only for widening the performance by further improving the performance, but also as a member requiring high strength, such as a building material and a car, as a single glass composition.

Sectional drawing of the vacuum heat insulating material in Embodiment 3 of this invention

Explanation of symbols

1 Vacuum insulation material 2 Core material 4 Outer packaging material

Claims (5)

A core material made of glass fiber is coated with an outer packaging material having gas barrier properties, and the inside of the outer packaging material is sealed under reduced pressure. The glass fiber is 45% by weight, SiO ₂ is 45 to 75%, Al ₂ O _3. Is 0-25%, B ₂ O ₃ is 0-12%, Na ₂ O is 0-20%, K ₂ O is 0-3%, MgO is 0-15%, CaO is 11-30%, other A vacuum heat insulating material comprising a glass composition having a composition of 3% or less and a total of 100% by weight of the respective compositions. A core material made of glass fiber is coated with an outer packaging material having a gas barrier property, and the inside of the outer packaging material is hermetically sealed under reduced pressure. The glass fiber is 50% by weight, SiO ₂ is 50 to 65%, Al ₂ O _3. Is 0 to 18%, B ₂ O ₃ is 2 to 10%, Na ₂ O is 0 to 20%, K ₂ O is 0 to 3%, MgO is 0 to 10%, CaO is 11 to 23%, other A vacuum heat insulating material comprising a glass composition having a composition of 3% or less and a total of 100% by weight of the respective compositions.   The glass component contains at least one kind of alkali metal oxide and alkaline earth metal oxide, respectively, and the alkaline earth metal oxide is more than the numerical value of the total weight% of the components of the alkali metal oxide. The vacuum heat insulating material according to claim 1, wherein the numerical value of the total weight% of the components is large.   The total of the alkali metal oxide and the alkaline earth metal oxide in the glass component is in a range of 20% to 45% by weight, and the total amount is 4%. Vacuum insulation material.   The heat insulating material which consists of a core material of the vacuum heat insulating material as described in any one of Claim 1 to 4.

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