KR20160014530A

KR20160014530A - Process for producing an insulating board and a vacuum insulation panel

Info

Publication number: KR20160014530A
Application number: KR1020150103547A
Authority: KR
Inventors: 히로노리 사토; 노부히로 시노하라; 유야 하마다; 다케시 나라키; 준이치 사이토; 다카오 모토지마
Original assignee: 아사히 가라스 가부시키가이샤
Priority date: 2014-07-29
Filing date: 2015-07-22
Publication date: 2016-02-11
Also published as: GB2531116A; CN105318145A; JP2016033419A; GB201513280D0

Abstract

The present invention relates to a method for producing an insulating plate and a method for producing a vacuum insulating material. According to the present invention, the method of the present invention can prevent defects such as breakage or expansion and ensures production of insulating plates with high productivity. By applying the method of the present invention, maintenance of a molding apparatus becomes easy while reducing costs. To this end, the method for producing the insulating plate comprises a molding process to obtain the insulating plate by press-molding a powder-containing insulating material M while interposing porous sheets (32, 34) on both side of between an upper mold (10) and the insulating material M and between a lower mold (12) and the insulating material M, allowing the porous sheet to be closed to the insulating material M. In addition, the method for producing the vacuum insulating material has a process of obtaining the insulating plate by the insulating plate production method and a process of decompress-sealing the obtained insulating plate in an exterior pocket.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing an insulating plate and a vacuum insulating material,

The present invention relates to a heat insulating plate and a method of manufacturing a vacuum insulating material.

BACKGROUND ART Insulation materials such as vacuum insulation materials have been widely used in order to reduce the heat and cooling energy by high thermal insulation such as houses and buildings, and by heat insulation and heat insulation on doors and roofs of automobiles. As the heat insulating material, for example, there can be enumerated an insulating plate in which a heat insulating material including powder such as silica is molded into a plate shape.

As a manufacturing method of an insulating plate, there is known a method of obtaining an insulating plate by press molding (uniaxial molding) a heat insulating material containing powder from a top and a bottom using a molding apparatus. Specifically, for example, there is a method of obtaining an insulating plate by press-molding a heat insulating material containing powder into a plate form from a top and a bottom with a pair of molding plates in a molding die for forming a molding space 1, 2).

However, in this method, since the fluidity of the powder is poor, the air in the heat insulating material is not easily released at the time of press forming, and particularly, the compressed air is likely to remain in the heat insulating plate at the central portion of the heat insulating plate. As a result, when the pressure is released, the compressed air expands, causing cracking in the heat insulating plate, or expansion, resulting in a problem that the density becomes lower than the target value. The problem is particularly likely to occur when an insulating plate having a low density and a relatively low strength of 0.15 to 0.35 g / cm 3 is produced.

If the press time is lengthened and the press pressure is gradually increased, air in the heat insulating material can be sufficiently removed at the time of press forming. However, in this method, productivity is greatly reduced.

As a method of efficiently extracting air in the heat insulating material at the time of press molding, a method is known in which a pair of molding plates for press-molding a heat insulating material in the molding die for forming a molding space are provided in a plurality of exhaust holes (Patent Document 3). In this method, the air in the heat insulating material efficiently escapes through the exhaust hole of the plate during press forming.

Japanese Patent Application Laid-Open No. 2014-94563 Japanese Patent Application Laid-Open No. 2014-94564 Japanese Patent Application Laid-Open No. 2014-95471

However, in the method of Patent Document 3, since the conventional molding apparatus can not be used, the facility cost is increased. In addition, a problem that the opening portion of the exhaust hole on the heat insulating material side is blocked by the powder tends to occur, and the maintenance of the molding apparatus is also troublesome.

An object of the present invention is to provide a method of manufacturing an insulating plate which can manufacture a heat insulating plate with high productivity while suppressing occurrence of defects such as cracking and expansion and is easy to maintain and repair the molding apparatus and is low in cost, And a method for manufacturing a vacuum insulator using the same.

The present invention provides a method of manufacturing an insulating plate and a vacuum insulating material having the following structures [1] to [9].

[1] A method of manufacturing an insulating plate having a molding step of press-molding a heat insulating material containing powder into a plate shape by a molding apparatus having a top mold and a bottom mold,

Wherein the press molding is performed in a state in which the porous sheet is interposed between the upper mold and the heat insulating material and between the lower mold and the heat insulating material or both of the lower mold and the heat insulating material so as to be in contact with the heat insulating material.

[2] The heat insulating plate according to [1], wherein either or both of the upper and lower molds are in contact with the porous sheet interposed between the heat insulating material and the porous sheet, &Lt; / RTI >

[3] The method for producing an insulating plate according to [2], wherein the ratio of the depth and width of the groove formed in the mold surface contacting with the porous sheet (groove depth / groove width) is 0.1 or more.

[4] The porous sheet according to any one of [1] to [3], wherein either or both of the upper and lower molds are in contact with the porous sheet interposed between the heat insulating material and the porous sheet, Wherein the heat insulating plate is made of a metal.

[5] The heat insulating material according to any one of [1] to [4], wherein at least one of the upper and lower molds is in contact with the porous sheet interposed between the heat insulating material and the heat insulating material, Wherein a hole is formed in the insulating layer.

[6] The method for manufacturing an insulating plate according to any one of [1] to [5], wherein the heat insulating material further comprises a binder.

[7] The method of manufacturing an insulating plate according to any one of [1] to [6], wherein the heat insulating material further comprises fibers.

[8] A method for producing an insulating plate according to any one of [1] to [7], wherein an insulating plate having a density of 0.15 to 0.35 g / cm 3 is obtained.

[9] The method for manufacturing an insulating plate according to any one of [1] to [8], wherein the heat insulating plate is a core material of vacuum heat insulating material.

[10] A method for producing a vacuum insulation material, comprising the steps of: obtaining an insulating plate by the method for manufacturing an insulating plate according to the above [9]; and vacuum-sealing the obtained insulating plate in an outer bag.

INDUSTRIAL APPLICABILITY According to the method of manufacturing an insulating plate of the present invention, it is possible to manufacture a heat insulating plate with high productivity while suppressing occurrence of defects such as cracking and expansion, and maintenance and repair of the molding apparatus is easy and low cost.

According to the method of manufacturing a vacuum insulator of the present invention, it is possible to manufacture a vacuum insulator with high productivity while suppressing the occurrence of defects such as cracking or expansion in the heat insulating plate.

Fig. 1 is a cross-sectional view showing an example of a molding apparatus used in the method for manufacturing an insulating plate of the present invention.
Fig. 2 is an enlarged cross-sectional view of the vicinity of the side wall of the lower mold in the molding apparatus of Fig. 1;
3 is a cross-sectional view showing a molding step in the method of manufacturing an insulating plate using the molding apparatus shown in Fig.
4 is a cross-sectional view showing a molding step in the method of manufacturing an insulating plate using the molding apparatus of Fig.
5 is a cross-sectional view showing a molding step in a method of manufacturing an insulating plate using another molding apparatus.
Fig. 6 is a cross-sectional view showing a molding step in the method of manufacturing an insulating plate using another molding apparatus. Fig.
Fig. 7 is a cross-sectional view showing a molding step in a method of manufacturing an insulating plate using another molding apparatus. Fig.
8 is a cross-sectional view showing a molding step in a method of manufacturing an insulating plate using another molding apparatus.
9 is a cross-sectional view showing a molding step in a manufacturing method of an insulating plate using another molding apparatus.
10 is a cross-sectional view showing a molding step in a method of manufacturing an insulating plate using another molding apparatus.
11 is a cross-sectional view showing a molding step in a method of manufacturing an insulating plate using another molding apparatus.

Definitions of the following terms apply throughout the present specification and claims.

"Porous sheet" means a sheet-like porous body having a large number of pores and having air permeability capable of allowing air to pass through the pores without allowing the heat insulating material material to escape through the pores thereof .

Means a binder previously applied to the surface of the fumed silica before it is mixed with other components such as porous silica and fibers. Further, fumed silica refers to silica fine particles including amorphous, spherical primary particles free from pores. The fumed silica is obtained by, for example, vaporizing silicon tetrachloride and performing a gas phase reaction in a high temperature hydrogen flame.

The term "radiation inhibitor" refers to a substance that either reflects (scatters) infrared light or absorbs infrared light once and radiates the temperature rise caused by its absorption isotropically so as to dissipate the directionality of the infrared light, Or < / RTI >

"Fiber length D30" means a fiber length at a point of 30% in the cumulative number distribution curve where the total number of fiber length distributions obtained on the number basis is 100%. The " fiber length D90 " means a fiber length of 90% in the cumulative number distribution curve where the total number of fiber length distributions obtained on the number basis is 100%. The fiber length distribution is obtained from a frequency distribution and a cumulative number distribution curve obtained by randomly measuring the length of 50 or more fibers in a photograph observed with an optical microscope.

[First Embodiment]

A method of manufacturing an insulating plate of the present invention is a method having a molding step of obtaining a heat insulating plate by press molding a heat insulating material containing powder into a plate shape by a molding apparatus having a top mold and a bottom mold. Hereinafter, the case of using the molding apparatus 1 exemplified in Figs. 1 and 2 will be described as an example of the method of manufacturing the heat insulating plate of the present invention.

(Molding apparatus)

The molding apparatus 1 is an apparatus for press molding a heat insulating material into a plate shape and has a top mold 10 and a bottom mold 12 as shown in Fig.

The mold surface 10a of the upper mold 10 has a planar shape.

The lower die 12 has a bottom portion 12a and a side wall portion 12b rising from the periphery of the bottom portion 12a so as to surround the periphery. A recessed portion 12c is formed on the inner side of the bottom portion 12a and the side wall portion 12b of the lower die 12. The planar shape of the concave portion 12c of the lower die 12 is substantially equal to the planar shape of the upper die 10. The size of the opening of the concave portion 12c of the lower die 12 is slightly larger than the size of the die surface 10a of the upper die 10.

The planar shape of the concave portion 12c of the lower mold 12 and the shape of the mold surface 10a of the upper mold 10 are determined according to the shape of the intended heat insulating plate.

In the molding apparatus 1, the upper die 10 is pulled in from above into the recess 12c of the lower die 12, and the heat insulating material filled in the recess 12c is press-molded from the upper and lower sides into a plate It is possible. As described above, in the molding apparatus 1, the upper mold 10 has a male mold and the lower mold 12 has a female mold.

A clearance 16 is formed between the upper mold 10 and the side wall 12b of the lower mold 12 when the upper mold 10 is drawn into the recess 12c of the lower mold 12 . This allows the air in the heat insulating material to escape from the clearance 16 between the upper die 10 and the side wall 12b of the lower die 12 during press forming.

In the molding apparatus 1, a slight gap 18 is also present between the bottom portion 12a of the lower mold 12 and the side wall portion 12b. Therefore, at the time of press forming, the air in the heat insulating material can escape from the gap 18 between the bottom portion 12a of the lower die 12 and the side wall portion 12b.

The distance d1 (Fig. 2) between the upper mold 10 and the side wall 12b of the lower mold 12 when the upper mold 10 is pulled into the concave portion 12c of the lower mold 12 is 0.1 - 3 mm is preferable, and 0.2 to 2 mm is more preferable. If the distance d1 is equal to or smaller than the lower limit value, the air in the heat insulating material tends to escape from the molding apparatus 1 through the clearance 16 between the upper mold 10 and the lower mold 12 side wall 12b. When the distance d1 is less than the upper limit value, leakage of the heat insulating material from the clearance 16 between the upper mold 10 and the side wall 12b of the lower mold 12 during press molding can be suppressed.

As the upper mold 10 and the lower mold 12, a special material is not used. For example, a mold commonly used in press forming can be employed. As the material of the mold, a resin or the like other than metal may be used.

(Insulation material)

The heat insulating material used in the method for manufacturing an insulating plate of the present invention includes powder. In addition, it is preferable that one or both of the fibers and the binder are contained in the heat insulating material in addition to the powder in terms of obtaining a heat insulating plate of higher strength.

(Powder)

As the powder, a known powder generally used for the insulating plate can be used. Specific examples thereof include fumed silica, porous silica, and radiation suppressing agents. As the powder, it is preferable to include fumed silica in that an insulating plate having sufficient strength is easily obtained.

The powder may be one kind or two or more kinds.

Since fumed silica is a very fine powder, a specific surface area is usually used as an index indicating the particle size.

The specific surface area of the fumed silica is preferably 50 to 400 m 2 / g, more preferably 100 to 350 m 2 / g, and particularly preferably 200 to 300 m 2 / g. If the specific surface area of the fumed silica is not less than the above lower limit value, excellent heat insulating performance tends to be obtained. If the specific surface area of the fumed silica is not more than the above upper limit value, it is easy to attach the binder to the surface of the particles.

The specific surface area in the present invention is measured by a nitrogen adsorption method (BET method).

Specific examples of the fumed silica include Aerosil 200 (specific surface area 200 m2 / g, manufactured by Nippon Aerosil Co., Ltd.), Aerosil 300 (specific surface area 300 m2 / g, manufactured by Nippon Aerosil Co., Ltd.) CAB-O-SIL H-300 (specific surface area 300 m < 2 > / g, manufactured by Cabot Japan K.K.), rheol And yarn QS30 (specific surface area 300 m < 2 > / g, manufactured by Tokuyama Co., Ltd.).

The fumed silica may be used alone or in combination of two or more.

The specific surface area of the porous silica is preferably 100 to 800 m 2 / g, more preferably 200 to 750 m 2 / g, and particularly preferably 300 to 700 m 2 / g. When the specific surface area of the porous silica is not lower than the lower limit value, excellent heat insulating performance tends to be obtained. When the specific surface area of the porous silica is less than the upper limit value, the amount of the binder absorbed in the porous silica can be reduced when the binder is used. Thereby, the heat insulating plate can be molded with the pressure of the binder to be added being at least lower. As a result, the density of the heat insulating plate can be lowered, and excellent heat insulating performance is easily obtained.

The porosity of the porous silica is preferably 60 to 90%, more preferably 65 to 85%, and particularly preferably 70 to 80%. When the porosity of the porous silica is not less than the above lower limit value, the heat conductivity of the solid can be reduced, and therefore excellent heat insulating performance is easily obtained. When the porosity of the porous silica is not more than the upper limit, porous silica particles are hardly crushed at the time of molding, and porosity is maintained, so that excellent heat insulating performance tends to be obtained.

The porosity is measured by a nitrogen adsorption method (BJH method).

The average particle diameter of the porous silica is preferably 1 to 300 占 퐉, more preferably 2 to 150 占 퐉, and more preferably 3 to 100 占 퐉, as measured by a laser diffraction scattering method, a Coulter counter method, Particularly preferred. If the average particle diameter of the porous silica is not less than the above lower limit value, porous silica having a high porosity tends to be obtained, and excellent heat insulating performance tends to be obtained. If the average particle diameter of the porous silica is not more than the upper limit value, the density of the heat insulating plate is not excessively increased, and excellent heat insulating performance tends to be obtained.

Specific examples of the porous silica include, for example, M.S.GEL and Sunspear (both manufactured by AGC Co., Ltd.).

The porous silica may be used alone or in combination of two or more.

Examples of the radiation inhibitor include metal particles (aluminum particles, silver particles, gold particles and the like), and inorganic particles (graphite, carbon black, silicon carbide, titanium oxide, tin oxide and potassium titanate).

The radiation inhibitor may be used alone or in combination of two or more.

(bookbinder)

It is preferable that a binder is included in the heat insulating material in that a sufficient strength is easily obtained even when the heat insulating plate is made low, and the powders are hardly penetrated into the pores of the porous sheet by bonding the powder and the components other than the powder and the powder . In particular, it is preferable to use fumed silica as the powder and to give a binder to the surface of the fumed silica in advance to obtain binder-fumed silica. Even if the pressure at the time of molding is low, the binder attached to the surface of the fumed silica bonds the fumed silica with the binder or the binder-modified fumed silica with other materials (porous silica, fiber, etc.).

Even if a binder is added to the porous silica, the effect of the binder is hardly obtained because the binder is absorbed by the porous silica.

The binder may be an organic binder or an inorganic binder. Above all, as the binder, an inorganic binder is preferable because of low thermal conductivity and excellent heat-insulating property.

Examples of the inorganic binder include sodium silicate, aluminum phosphate, magnesium sulfate, magnesium chloride, and the like. Among them, sodium silicate is particularly preferable in view of obtaining an excellent heat insulating property.

Only one kind of binder may be used, or two or more kinds of binders may be used in combination.

(fiber)

If fibers are contained in the heat insulating material, a high-strength heat insulating plate is likely to be obtained. Further, the powder is introduced into the intertwined fibers to form a lump, whereby the powder is less likely to enter the pores of the porous sheet.

As the fiber, a fiber commonly used for a vacuum insulation material can be used, and for example, a resin fiber and an inorganic fiber can be mentioned. Among them, the inorganic fiber is preferable in that when the heat insulating plate is used as the core material of the vacuum heat insulating material, the outgas under vacuum is small, the deterioration of the heat insulating property due to the decrease in the degree of vacuum is easily suppressed, and the heat resistance is excellent.

The fibers may be used alone or in combination of two or more.

Examples of the inorganic fibers include alumina fibers, mullite fibers, silica fibers, glass wool, glass fibers, rock wool, slag wool, silicon carbide fibers, carbon fibers, silica alumina fibers, silica alumina magnesia fibers, silica alumina zirconia fibers , Silica magnesia calcia fiber, and the like.

The fiber length D30 of the fibers used is preferably 100 mu m or more, and more preferably 200 mu m or more. When the fiber length D30 is not less than the above lower limit value, it is easy to suppress occurrence of cracking in the heat insulating plate.

The fiber length D90 of the fibers used is preferably 20 mm or less, more preferably 10 mm or less. If the fiber length D90 is not more than the above upper limit value, the fibers are not excessively entangled with each other, so that they are easily mixed uniformly with the powder, and the effect of the fibers is likely to be obtained.

The diameter (diameter) of the fibers is preferably 10 占 퐉 or less in that the increase in the solid heat transfer due to the fibers can be suppressed. Further, the thickness (diameter) of the fiber is preferably not less than 1 탆, since it is easy to suppress occurrence of cracking in the heat insulating plate.

(Ratio of powder, binder, fiber)

The proportion of the fumed silica in the powder (100 mass%) is preferably 50 to 100 mass%, more preferably 70 to 100 mass%, and particularly preferably 80 to 100 mass%. If the ratio of the fumed silica is not less than the above lower limit value, a heat insulating plate having high strength tends to be obtained.

The proportion of the porous silica in the powder (100 mass%) is preferably 0 to 50 mass%, more preferably 0 to 30 mass%, and particularly preferably 0 to 20 mass%. The larger the ratio of the porous silica, the more easily an insulating plate having excellent heat insulating performance can be obtained. If the proportion of the porous silica is not more than the upper limit value, a heat-insulating plate having high strength tends to be obtained.

In the case where the powder includes binder-fumed silica and porous silica which have been previously provided with a binder on the surface thereof, the ratio M _A / M _B of the mass M _A of the fumed silica and the mass M _B of the porous silica before application of the binder is preferably 50/50 or more More preferably 70/30 or more, and particularly preferably 80/20 or more. When the ratio M _A / M _B is not less than the lower limit value, it is easy to obtain a heat insulating plate having a low density and excellent heat insulating performance and a sufficient strength.

When the powder contains a radiation inhibitor, the proportion of the radiation inhibitor in the powder (100 mass%) is preferably from 3 to 30 mass%, more preferably from 5 to 25 mass%, and particularly preferably from 10 to 20 mass% . If the ratio of the radiation inhibitor is higher than or equal to the lower limit, the effect of the radiation inhibitor is likely to be obtained. When the ratio of the radiation inhibitor is not more than the upper limit value, the increase in the solid heat transfer due to the radiation inhibitor can be suppressed, and therefore excellent heat insulating performance tends to be obtained.

The binder is preferably used in an amount of 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, and more preferably 1 to 4 parts by mass, relative to 100 parts by mass of the fumed silica before application of the binder, in the case of using binder- Particularly preferred is a mass part. When the ratio of the binder is not less than the lower limit value, it is easy to obtain an insulating plate having a lower density and an excellent heat insulating performance and a sufficient strength. If the proportion of the binder is not more than the upper limit value, the increase in the solid heat transfer by the binder can be suppressed, so that deterioration of the heat insulating performance can be suppressed easily.

When binder fumed silica to which a binder is previously applied on the surface is not used, such as when fumed silica, a binder and other components (porous silica, fiber, etc.) are mixed at the same time, the binder ratio in 100 parts by weight of the powder 0.1 to 15 parts by mass is more preferable, 0.5 to 10 parts by mass is more preferable, and 1 to 4 parts by mass is particularly preferable. When the ratio of the binder is not less than the above lower limit value, it is easy to obtain a heat insulating plate having a low density and excellent heat insulating performance and a sufficient strength. If the ratio of the binder is not more than the upper limit value, the increase in the solid heat transfer by the binder can be suppressed, so that deterioration of the heat insulating performance can be suppressed easily.

The ratio of fibers is preferably from 1 to 30 parts by mass, more preferably from 2 to 20 parts by mass, and particularly preferably from 4 to 10 parts by mass, per 100 parts by mass of the powder. If the ratio of the fibers is not less than the lower limit value, a high-strength insulating plate tends to be obtained. If the ratio of the fibers is not more than the upper limit value, it is possible to suppress the increase of the solid heat transfer due to the fibers, so that deterioration of the heat insulating performance can be suppressed easily.

(Manufacturing method)

Examples of the method of manufacturing the heat insulating plate of the present embodiment include a method having the following mixing step, molding step, and heat treatment step.

Mixing process: Powder and other materials to be used as required are mixed and stirred to obtain an insulating material.

Molding process: Using the molding apparatus 1, the heat insulating material is placed between the upper mold 10 and the heat insulating material and between the lower mold 12 and the heat insulating material in such a manner that the porous sheet is in contact with the heat insulating material. And press-formed into a plate shape.

Heat treatment step: The heat insulating plate obtained in the above molding step is heat treated and dried.

(Mixing process)

For example, in the case of using powders, fibers and binders, as a mixing method of the respective components, for example, a method using a V-type mixer or a blender with a stirrer may be used. Among them, a method of using a high-speed stirring device such as a blender with a stirrer is preferable in that the dispersibility of each component becomes good.

In the case of using fumed silica, porous silica and a binder in combination, it is preferable to add binder to the surface in advance to obtain a binder-fumed silica, and then to mix the binder-fumed silica and the porous silica. As a result, the binder can be prevented from being absorbed by the porous silica, so that the amount of the binder used can be reduced.

The timing of mixing the binder is not particularly limited, and for example, fumed silica, porous silica, fibers and a binder may be mixed at the same time.

The binder is preferably dissolved in a solvent and mixed as a binder solution. The solvent used for the binder solution is not particularly limited, and examples thereof include water and ethanol.

The proportion of the binder in the binder solution (100 mass%) is preferably 4 to 60 mass%, more preferably 10 to 50 mass%. When the ratio of the binder is within the above range, the binder is easily given to the powder. As the binder solution, water glass as an aqueous solution of sodium silicate is particularly preferable.

The binder solution may be applied to powder or fiber by spray coating or the like.

(Molding step)

3, a tray 30 is provided on the bottom of the concave portion 12c of the lower die 12 of the molding apparatus 1, and a porous sheet (not shown) The heat insulating material M is filled on the porous sheet 32 in the concave portion 12c of the lower die 12 and the porous sheet 34 is disposed thereon.

By using the tray 30 in the molding process, the heat insulating plate obtained after the press molding can be conveyed to the next process while being stuck on the tray 30. As a result, even if the heat insulating plate has a low density, damage to the heat insulating plate is less likely to occur during transportation, and handling properties are improved.

The tray 30 may be any tray capable of withstanding pressure at the time of press forming and may be, for example, an aluminum tray or the like.

The porous sheet 32 may be any of those having air permeability and capable of withstanding pressure at the time of press forming, and examples thereof include glass cloth, metal mesh and the like.

The planar shape of the porous sheet 32 may be a shape corresponding to the planar shape of the desired heat insulating plate.

The thickness of the porous sheet 32 is preferably 0.05 to 0.5 mm, more preferably 0.1 to 0.3 mm. If the thickness of the porous sheet 32 is not less than the above lower limit value, air in the heat insulating material tends to pass through the porous sheet during press forming, and it becomes easy to produce a high quality heat insulating plate with high productivity. When the thickness of the porous sheet 32 is less than the upper limit value, the plate thickness control of the product becomes easy.

When a glass cloth is used as the porous sheet 32, the glass cloth density (mass per square meter) is preferably 250 to 700 g / m 2, more preferably 300 to 600 g / m 2. If the glass cloth density is not less than the above lower limit value, passage of the powder is easily suppressed. If the glass cloth density is below the above upper limit value, the effect of air venting is likely to be sufficiently obtained.

When a metal mesh is used as the porous sheet 32, the mesh number of the metal mesh is preferably 15 to 400 mesh, more preferably 20 to 300 mesh. If the mesh number of the metal mesh is equal to or lower than the lower limit value, passage of the powder is easily suppressed. If the mesh number of the metal mesh is less than the upper limit value, the air venting effect is easily obtained.

In addition, the number of meshes means the number of meshes existing in one inch.

The porous sheet 34 may be any of those having air permeability and capable of withstanding pressure at the time of press forming. For example, the porous sheet 34 may be the same as the porous sheet 32, and the preferred embodiment is also the same.

Subsequently, by lowering the upper mold 10, the porous sheets 32, 32 are brought into contact with the heat insulating material M at both sides between the upper mold 10 and the heat insulating material and between the lower mold 12 and the heat insulating material, 34, the heat insulating material M is press-formed into a plate shape.

In this example, since the porous sheet 34 exists between the upper die 10 and the heat insulating material M so as to contact the heat insulating material M, air in the heat insulating material M passes through the porous sheet 34 at the time of press forming, It is easy to reach the clearance 16 of the side wall portion 12b of the lower die 10 and the lower die 12. As a result, the air passes through the porous sheet 34 and easily escapes from the clearance 16 out of the apparatus, not only from the peripheral portion but also from the central portion of the heat insulating material M press-molded into a plate shape. Since the porous sheet 32 exists between the lower die 12 and the heat insulating material M so as to be in contact with the heat insulating material M, air in the heat insulating material M passes through the porous sheet 32 at the time of press forming, And the gap 18 between the bottom wall 12a and the side wall 12b. As a result, not only the peripheral portion but also the central portion of the heat insulating material M which is press-formed in the form of a plate passes through the porous sheet 32 and easily escapes from the gap 18 out of the apparatus.

Thus, air can be efficiently extracted from the heat insulating material M even in a short-time press molding.

The pressure at the time of press forming may be suitably set in accordance with the composition of the heat insulating material M, the thickness of the target heat insulating plate, and the like.

The press time is preferably as short as possible within a range that does not cause problems such as cracking or expansion in the heat insulating plate obtained for the purpose of improving productivity.

(Heat treatment process)

By heat-treating the heat insulating plate obtained in the molding step, the solvent remaining in the heat insulating plate is volatilized, and the binder and the powder and the fiber are bonded together more favorably by the binder.

A method of heat-treating the heat insulating plate is not particularly limited, and examples thereof include a method of heating with a constant temperature drier, an electric furnace or the like.

The density of the insulating plate is preferably 0.15 to 0.35 g / cm3, more preferably 0.17 to 0.30 g / cm3. If the density of the heat insulating plate is not lower than the above lower limit value, the handling property of the heat insulating plate becomes good. Further, in the case of using a vacuum insulator, it is difficult for the heat insulator material to scatter when the heat insulator is pressure-sealed in the outer bag. If the density of the heat insulating plate is less than the upper limit value, excellent heat insulating performance tends to be stably obtained.

(Action effect)

In the conventional manufacturing method of the heat insulating plate as in Patent Documents 1 and 2, although the peripheral portion air of the heat insulating material is released when the heat insulating material is press molded into the plate shape, since the air in the central portion of the heat insulating material is hardly released, There is a problem that breakage or expansion occurs.

On the other hand, in the method of manufacturing the heat insulating plate of the present embodiment, the porous sheets 32 and 34 are provided so as to be in contact with the heat insulating material M both between the upper die 10 and the heat insulating material M and between the lower die 12 and the heat insulating material M. And press molding is performed in a state in which it is interposed. As a result, even in a short-time press molding, air can easily come out of the apparatus through the porous sheets 32, 34 from the central portion of the heat insulating material M, and the heat insulating plate can be manufactured with high productivity while suppressing the occurrence of cracking or expansion .

In addition, the method for manufacturing the heat insulating plate of the present embodiment can be realized by simply installing the porous sheets 32, 34 by a conventional molding apparatus. In addition, even if the porous sheets 32 and 34 are closed by powder, it is only necessary to replace the porous sheets 32 and 34. Therefore, as compared with the case where the exhaust holes formed on the plate are closed as in Patent Document 3 Maintenance is also easy. Therefore, according to the manufacturing method of the heat insulating plate of the present embodiment, it is possible to easily manufacture the heat insulating plate at low cost.

[Second Embodiment]

In the method of manufacturing an insulating plate of the present invention, one or both of the upper mold and the lower mold is in contact with the porous sheet interposed between the upper and lower molds and the heat insulating material in view of easy removal of air from the heat insulating material more efficiently, It is preferable to use a molding apparatus in which a groove is formed on a mold surface in contact with the mold.

It has been found that it is possible to extend the number of times of use of the sheet as an unexpected effect because the groove is formed on the surface in contact with the porous sheet. Although the detailed reason is unclear, the following presumption is made.

As described above, since the porous sheet is pressed in contact with the powder, the powder remains in the pores gradually and clogs the pores. If there is no groove in the forming die, the air is taken out through the porous sheet, so that if the powder remains in the pores and the pores are closed, the air from the powder in the vicinity of the center becomes difficult to pass through the sheet , The molded body may be deformed or broken or may be easily formed. However, if grooves are formed in the molding die, the distance of permeation of air is short even in the vicinity of the center, so that the air tends to run away, and thus the moldability can be maintained.

Hereinafter, as a concrete example of this embodiment, a case of using the molding apparatus 2 exemplified in Fig. 5 will be described. 5 are denoted by the same reference numerals and the description thereof is omitted.

(Molding apparatus)

The molding apparatus 2 is the same as the molding apparatus 1 except that the upper mold 10 has an upper mold 10A in which a plurality of grooves 20 are formed in a mold surface 10a. The upper mold 10A is the same as the upper mold 10 except that a plurality of grooves 20 are formed in the mold surface 10a.

It is preferable that the grooves 20 are formed on the entire surface of the mold surface 10a of the upper mold 10A in view of the fact that air can be easily released from the heat insulating material more efficiently. In addition, the shape of the plurality of grooves 20 is preferably a lattice shape. It is preferable that both ends of the groove 20 extend to the edge of the mold surface 10a of the upper mold 10A.

The pitch of the grooves 20 is preferably 50 mm or less, more preferably 40 mm or less. If the pitch of the grooves 20 is less than the upper limit value, the effect of air venting is sufficiently obtained. It is preferable that the pitch of the grooves 20 be as small as possible for the labor of the processing.

The depth of the groove 20 is preferably 0.1 to 2.5 mm, more preferably 0.2 to 1.0 mm, and further preferably 0.5 to 1 mm. If the depth of the groove 20 is not less than the above lower limit value, the effect of air ventilation is easily obtained. If the depth of the grooves 20 is less than the upper limit value, the upper mold 10A and the porous sheet 34 are less likely to engage with each other and the porous sheet 34 can be easily separated. The width of the groove 20 is preferably 1 to 10 mm, more preferably 2 to 8 mm. If the width of the groove 20 is not smaller than the above lower limit value, the effect of air venting can be sufficiently obtained and the porous sheet 34 can be prevented from being entrained in the groove 20. If the width of the groove 20 is less than the upper limit value, the effect of forming the groove 20 for venting is likely to be obtained sufficiently.

It is preferable that the ratio of the depth and width of the groove (groove depth / groove width) is 0.1 or more. If the ratio of the groove depth to the width is smaller than 0.1, the porous sheet may adhere to the wall surface of the groove during molding, so that sufficient air venting effect may not be obtained.

The method of forming the grooves 20 in the mold surface 10a of the upper mold 10A is not particularly limited and examples thereof include general mechanical processing and electrical discharge machining.

(Manufacturing method)

Molding process: Using the molding apparatus 2, the heat insulating material is placed on both the upper mold 10A and the heat insulating material and between the lower mold 12 and the heat insulating material so that the porous sheet is in contact with the heat insulating material. And press-formed into a plate shape.

The mixing process and the heat treatment process can be performed in the same manner as in the first embodiment. The molding process can be carried out in the same manner as in the first embodiment except that the molding apparatus 2 is used.

(Action effect)

In this embodiment, since the plurality of grooves 20 are formed in the mold surface 10a of the upper mold 10A, the air that has exited the porous sheet 34 from the heat insulating material M side to the mold surface 10a during press forming Reaches the clearance 16 of the upper mold 10 and the side wall 12b of the lower mold 12 through the groove 20. This makes it easier for the air in the heat insulating material M to fall out of the apparatus than in the case of using the molding apparatus 1. Therefore, even in a short-time press forming, since the air in the heat insulating material M is more efficiently discharged, it is possible to manufacture the heat insulating plate with higher productivity while suppressing the occurrence of cracking and expansion.

Since the porous sheet 34 is disposed on the mold surface 10a side of the upper mold 10A in the manufacturing method of the heat insulating plate of the present embodiment, the grooves 20 formed on the mold surface 10a of the upper mold 10A, As shown in Fig. In addition, even if the porous sheets 32 and 34 are closed by powder, it is only necessary to replace the porous sheets 32 and 34. Therefore, as compared with the case where the exhaust holes formed on the plate are closed as in Patent Document 3 Maintenance is also easy.

[Third embodiment]

In the method of manufacturing an insulating plate of the present invention, it is preferable that at least one of the upper and lower molds is in contact with the porous sheet interposed between the upper and lower molds and the heat insulating material, It is preferable to use a molding apparatus in which the portion in contact with the sheet is porous.

Hereinafter, the case of using the molding apparatus 3 exemplified in Fig. 6 will be described as a concrete example of this embodiment. The same parts as those in Fig. 4 in Fig. 6 are denoted by the same reference numerals, and a description thereof will be omitted.

(Molding apparatus)

The molding apparatus 3 is provided with an upper mold 10B in which a plurality of through holes 22 are formed in the thickness direction of the heat insulating material M press-molded from the mold surface 10a to the mold surface 10b opposite to the upper mold 10, ), The same as the molding apparatus 1. The upper die 10B is the same as the upper die 10 except that a plurality of through holes 22 are formed. The upper die 10B is formed as a porous body by forming a plurality of through holes 22 therein.

It is preferable that the through holes 22 are uniformly formed on the entire surface of the mold surface 10a of the upper mold 10B in view of the fact that the air is easily released from the heat insulating material more efficiently.

The pitch of the through holes 22 is preferably 10 to 100 mm, more preferably 15 to 80 mm. If the pitch of the through holes 22 is not less than the above lower limit value, the strength of the upper mold 10B can be sufficiently secured. If the pitch of the through holes 22 is not more than the upper limit value, the effect of venting is likely to be obtained sufficiently.

The diameter (diameter) of the through hole 22 is preferably 0.1 to 3.0 mm, more preferably 0.3 to 2.0 mm. When the hole diameter of the through hole 22 is not less than the lower limit value, clogging of the through hole 22 by the powder can be easily prevented. If the hole diameter of the through hole 22 is not more than the upper limit value, the unevenness of the surface of the heat insulating plate and the surface of the vacuum insulating material is suppressed to 1 mm or less.

The opening area of the one through hole 22 on the mold surface 10a side is preferably 0.01 to 0.5%, more preferably 0.03 to 0.3% of the total area of the mold surface 10a (including the opening area of the through hole) More preferable. If the opening area is equal to or more than the lower limit value, the effect of venting is likely to be obtained. If the opening area is not more than the upper limit value, the strength of the upper mold 10B can be sufficiently secured.

The method for forming the through hole 22 in the upper mold 10B is not particularly limited and may be, for example, a general machine or a hole boring process by electric discharge machining.

(Manufacturing method)

Molding process: Using the molding apparatus 3, the heat insulating material is placed on both the upper mold 10B and the heat insulating material and between the lower mold 12 and the heat insulating material so that the porous sheet is in contact with the heat insulating material. And press-formed into a plate shape.

The mixing process and the heat treatment process can be carried out in the same manner as in the first embodiment. The molding process can be carried out in the same manner as in the first embodiment except that the molding apparatus 3 is used.

(Action effect)

In the present embodiment, since the plurality of through holes 22 are formed in the upper die 10B, the air that has exited the porous sheet 34 from the heat insulating material M side to the die surface 10a side during press forming, (22). &Lt; / RTI > This makes it easier for the air in the heat insulating material M to fall out of the apparatus than in the case of using the molding apparatus 1. [ Therefore, even in a short-time press forming, since the air in the heat insulating material M is more efficiently discharged, it is possible to manufacture the heat insulating plate with higher productivity while suppressing the occurrence of cracking and expansion.

Since the porous sheet 34 is disposed on the mold surface 10a side of the upper mold 10B in the manufacturing method of the heat insulating plate of the present embodiment, the through holes 22 formed in the upper mold 10B are closed by the powder . In addition, even if the porous sheets 32 and 34 are closed by powder, it is only necessary to replace the porous sheets 32 and 34. Therefore, as compared with the case where the exhaust holes formed on the plate are closed as in Patent Document 3 Maintenance is also easy.

[Fourth Embodiment]

The method of manufacturing the heat insulating plate of the present invention may be a method of using the molding apparatus 4 shown in Fig. 7, for example, in the case of forming grooves on the mold surface on the lower mold side in the upper mold. The same parts as those in Fig. 4 in Fig. 7 are denoted by the same reference numerals, and a description thereof will be omitted.

The molding apparatus 4 is provided on the side of the lower mold 12 in the upper mold body 10c and the upper mold body 10c instead of the upper mold 10 and has a plurality of grooves 20 on the side of the lower mold 12, Except that the upper die 10C having the grooved plate 10d with the grooves 10d formed therein is provided.

The porous sheets 32 and 34 are brought into contact with the heat insulating material M at both sides between the upper mold 10C and the heat insulating material M and between the lower mold 12 and the heat insulating material M as shown in Fig. By molding the material M into a plate shape, it is possible to manufacture the heat insulating plate with high productivity while suppressing occurrence of defects such as cracking and expansion.

[Fifth Embodiment]

The method for manufacturing the heat insulating plate of the present invention may be a method using the molding apparatus 5 shown in Fig. The same parts as those in Fig. 4 in Fig. 8 are denoted by the same reference numerals, and a description thereof will be omitted.

The molding apparatus 5 is provided with a lower mold 12A in which a plurality of grooves 24 are formed on the inner side of the side wall portion 12b in the mold surface 12d on the upper side of the bottom portion 12a instead of the lower mold 12 Otherwise, it is the same as the molding apparatus 1.

The shape of the plurality of grooves 24 may be the same as that of the grooves 20, and the preferred embodiment is also the same.

As shown in Fig. 8, in the state where the porous sheets 32, 34 are interposed between the upper die 10 and the heat insulating material M and between the lower die 12A and the heat insulating material M so as to be in contact with the heat insulating material M, By molding the material M into a plate shape, it is possible to manufacture the heat insulating plate with high productivity while suppressing occurrence of defects such as cracking and expansion.

The air that has exited the porous sheet 32 from the heat insulating material M side to the mold face 12d side during the press molding is introduced into the bottom portion 12a of the lower mold 12 through the groove 24, And the gap 18 of the side wall portion 12b. This makes it easier for the air in the heat insulating material M to fall out of the apparatus than in the case of using the molding apparatus 1. Therefore, even in a short-time press forming, since the air in the heat insulating material M is more efficiently discharged, it is possible to manufacture the heat insulating plate with higher productivity while suppressing the occurrence of cracking and expansion.

[Sixth Embodiment]

The method for manufacturing the heat insulating plate of the present invention may be a method using the molding apparatus 6 exemplified in Fig. 4, 5, and 8 in Fig. 9 are denoted by the same reference numerals, and description thereof is omitted.

The molding apparatus 6 includes an upper mold 10A in which a plurality of grooves 20 are formed in a mold surface 10a in the same manner as the molding apparatus 2 in place of the upper mold 10, Is the same as the molding apparatus 1 except that a lower mold 12A having a plurality of grooves 24 formed in a mold surface 12d is provided.

9, in the state where the porous sheets 32, 34 are interposed between the upper die 10A and the heat insulating material M and between the lower die 12A and the heat insulating material M so as to contact the heat insulating material M, The material M is press-formed into a plate shape. As a result, air in the heat insulating material tends to be released at the time of press forming.

The air exiting the porous sheet 34 from the heat insulating material M side to the mold surface 10a during press forming is guided through the grooves 20 to the clearance between the upper mold 10 and the side wall 12b of the lower mold 12. [ (16). The air that has exited the porous sheet 32 from the heat insulating material M side to the mold face 12d side during the press molding is discharged through the groove 24 to the gap between the bottom portion 12a of the lower mold 12 and the side wall portion 12b (18). As described above, since the air in the heat insulating material M is easier to get out of the apparatus than in the case of using the molding apparatus 1, it is possible to manufacture the heat insulating plate with high productivity while suppressing occurrence of defects such as cracking and expansion.

[Seventh Embodiment]

Further, the method of manufacturing the heat insulating plate of the present invention is not limited to a method of using a molding apparatus in which the upper mold is of a male mold and the lower mold is of a female mold. For example, the molding apparatus 7 illustrated in Figs. 10 and 11 may be used.

The molding apparatus 7 has a top mold 40 and a bottom mold 50 as shown in Fig. The upper die 40 has a shaping plate 42 and a pressurizing portion 44 which presses the shaping plate 42 downward and presses it. The lower mold 50 includes a bottom 52, a side wall 54 rising upward from the periphery of the bottom 52 to surround the periphery, a recess 52a And a pressing portion 58 which penetrates through the bottom portion 52 and presses the molding plate 56 upward in the concave portion 50a and presses the molding plate 56 upward.

The molding plate 42 of the upper mold 40 does not enter the concave portion 50a of the lower mold 50 and the surface 42a of the molding plate 42 comes into contact with the side wall of the lower mold 50. [ (54).

10, the porous sheet 64 is disposed on the molding plate 56 of the lower mold 50, and the heat insulating material M is charged thereon After that, the porous sheet 62 is further disposed thereon. 11, the forming plate 56 is pushed up by the pressing portion 58 while pushing the forming plate 42 by the pressing portion 44 and the upper mold 40 is pressed down by the pressing portion 44, Press molding is performed in the state where the porous sheets 62 and 64 are sandwiched between the molding plate 42 and the heat insulating material M and between the molding plate 56 of the lower mold 50 and the heat insulating material M. As a result, the air in the heat insulating material M can easily fall out of the apparatus through the porous sheets 62 and 64, and the heat insulating plate can be manufactured with high productivity while suppressing the occurrence of cracking and expansion.

As described above, in the method of manufacturing the heat insulating plate of the present invention, press molding is performed in a state in which the porous sheet is interposed between the upper mold and the heat insulating material, or between the lower mold and the heat insulating material or both, Therefore, air in the heat insulating material tends to be released at the time of press forming. As a result, it is possible to manufacture the heat insulating plate with high productivity while suppressing the occurrence of defects such as cracking and expansion. Further, according to the method for manufacturing an insulating plate of the present invention, even when a low-density insulating plate having a density of 0.15 to 0.3 g / cm 3 is manufactured, it is possible to manufacture an insulating plate with high productivity while sufficiently suppressing occurrence of defects such as cracking and expansion .

Further, in the method of manufacturing the heat insulating plate of the present invention, the conventional molding apparatus can be used, and the molding apparatus can be easily maintained.

The method of manufacturing the heat insulating plate of the present invention is particularly effective as a method of manufacturing an insulating plate used as a core material of a vacuum thermal insulating material. The heat insulating plate obtained by the production method of the present invention may be used as a heat insulating material as it is.

[Other Embodiments]

In addition, the method of manufacturing the heat insulating plate of the present invention is not limited to the above-described embodiment.

For example, a method in which the porous sheet 34 is not used in the molding process using the molding apparatus 1 may be employed. Also in this method, since the press molding is carried out with the porous sheet interposed between the lower mold and the heat insulating material, it is possible to manufacture the heat insulating plate with high productivity while suppressing occurrence of defects such as cracking and expansion.

Further, in the molding process using the molding apparatuses 1 to 3, the porous sheet 32 may not be used. Also in this method, since the press molding is carried out with the porous sheet interposed between the upper mold and the heat insulating material, it is possible to manufacture the heat insulating plate with high productivity while suppressing occurrence of defects such as cracking and expansion.

Alternatively, the tray 30 may not be used.

Even in the case of using the molding apparatus 4, a method of press molding without arranging the porous sheet 32 between the lower die 12 and the heat insulating material may be employed.

In the molding apparatus 5, a method may also be employed in which press molding is performed without providing the porous sheet 34 between the upper die 10 and the heat insulating material M.

The method for manufacturing an insulating plate of the present invention is characterized in that in the molding apparatus 7, between the molding plate 42 of the upper mold 40 and the heat insulating material M and between the molding plate 56 of the lower mold 50 and the heat insulating material M The porous sheet may be press-formed without providing any one of the porous sheets.

When either or both of the upper mold and the lower mold are in contact with the porous sheet interposed between the upper and lower molds and the heat insulating material and a molding apparatus in which the portion in contact with the porous sheet is porous is used, It is not limited to the device 3.

For example, a method may be employed in which a molding apparatus in which a plurality of through holes are formed in a lower mold and a porous body is used, and a porous sheet is provided so as to be in contact with a mold surface in which the through holes are formed in the lower mold.

Further, a molding apparatus may be used in which the whole of either or both of the upper mold and the lower mold, or the side in contact with the porous sheet is partially made into a porous body containing porous ceramics. Examples of the material of the porous ceramics include alumina, silicon carbide and the like.

The method of manufacturing the heat insulating plate of the present invention may be a method without a heat treatment step, for example, when the binder solution is not used.

[Method of producing vacuum insulation material]

The method for producing a vacuum insulator of the present invention is a method including a step of obtaining an insulating plate by a method of manufacturing an insulating plate of the present invention and a step of pressure-sealing the obtained insulating plate in an outer bag. The vacuum insulator of the present invention can be manufactured by a known method other than the use of the insulating plate obtained by the method for manufacturing an insulating plate of the present invention.

The step of obtaining the heat insulating plate is as described above.

In the step of obtaining the vacuum insulator, for example, the heat insulating plate is contained in the outer bag, the outer bag is sealed under the reduced pressure condition, and then the vacuum insulator is obtained by returning to the atmospheric pressure condition. Specifically, for example, the following method can be mentioned.

Two sheets of film are superimposed to house an insulating plate in an outer bag sealed in three sides in advance and placed in a vacuum chamber having a heat sealing function, and the inside of the vacuum chamber is decompressed. After the chamber is depressurized to a predetermined pressure, the other open side of the outer bag is heat sealed and sealed, and then the inside of the chamber is returned to atmospheric pressure.

Further, after the heat insulating plate is housed in the outer bag, air in the outer bag is extracted to decompress the inside of the outer bag, and the outer bag is sealed with a heat seal or the like to compress the heat insulating plate in the outer bag.

(Outer pocket)

The outer bag may be one having airtightness and capable of pressure-sealing the heat insulating plate. Examples of the outer bag include a bag containing a gas barrier film and the like. As the gas barrier film, any known vacuum insulator can be used without limitation.

The size and shape of the outer bag are not particularly limited and may be suitably determined in accordance with the size and shape of the heat insulating plate.

The degree of vacuum in the outer bag in the vacuum insulator is preferably 1 x 10 ³ Pa or less, more preferably 1 x 10 ² Pa or less, from the point that excellent heat insulating performance is obtained and the life of the vacuum insulator is prolonged.

(Action effect)

According to the method for producing a vacuum insulator of the present invention, since the heat insulating plate is manufactured by the manufacturing method of the heat insulating plate of the present invention and the vacuum insulating material is manufactured by using the heat insulating plate, it is possible to suppress the occurrence of defects such as cracking and expansion in the heat insulating plate The vacuum insulator can be manufactured with high productivity.

In the method of manufacturing a vacuum insulator according to the present invention, a vacuum insulator may be obtained by vacuum-enclosing an insulating bag in an outer bag in an air bag having an air-permeable inner bag.

The inner bag is not particularly limited as long as it has air permeability and can prevent the powder forming the core material from leaking at the time of pressure-sealing. Examples of the inner bag include a bag made of paper material, nonwoven fabric, and the like.

The size and shape of the inner bag are not particularly limited and may be suitably determined in accordance with the size and shape of the heat insulating plate.

As a manufacturing method of the vacuum insulator in the case of using the inner bag, the same method as the above-described method can be adopted except that the heat insulating plate is housed in the inner bag and pressure-sealed in the outer bag.

[Example]

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to the following descriptions. Examples 1 to 7 are Examples, and 8 to 11 are Comparative Examples.

[Evaluation of insulating plate]

(Presence of breakage)

The obtained insulating plate was visually inspected, and the presence or absence of cracking was judged.

(Evaluation of closing)

The obtained insulating plate was visually confirmed, and the closing of the insulating plate was evaluated based on the following criteria.

(Good): No expansion is observed on the surface of the insulating plate.

× (poor): The surface of the insulating plate shows expansion.

(Quality judgment)

○: There is no crack or expansion in the insulating plate.

B: No cracks are seen in the heat insulating plate, but the surface of the heat insulating plate is expanded.

X: The insulating plate is cracked.

[Example 1]

90 parts by mass of fumed silica (trade name "Aerosil (300)", specific surface area 300 m 2 / g, manufactured by Nippon Aerosil Co., Ltd.) as a powder and 90 parts by mass of porous silica (trade name "MSGEL" (Trade name " Super Wool ", D30: 227 占 퐉, D90: 902 占 퐉, manufactured by Shin-Nippon Thermal Ceramics Co., Ltd.) as inorganic fibers, 10 parts by mass of sodium silicate 3 And 3.4 parts by mass (1.3 parts by mass in terms of solid content) of a binder (AGC Co., Ltd.) were mixed with a binder solution diluted with ion exchange water (25.0 parts by mass) to obtain a heat insulating material.

A tray 30 (tray made of aluminum) is provided on the bottom of the concave portion 12c of the lower mold 12 of the molding apparatus 1 shown in Fig. 1, and glass cloth # 470 (MOLYMERS-ASIS PISASA) was installed, and 884 g of the obtained heat insulating material was charged. Subsequently, the glass cloth # 470 (molimeter AS) was placed as the porous sheet 34 on the heat insulating material, and the top mold 10 was lowered. Under the conditions of the pressure (45t) and the pressing time of 10 minutes, Insulating material was press-molded so as to have a density of 0.22 g / cm 3 and a size of 500 mm in length x 500 mm in width x 13 mm in thickness, thereby obtaining a plate-like insulating plate.

[Example 2]

A heat insulating plate was produced in the same manner as in Example 1 except that the pressing time was changed to 5 minutes.

[Example 3]

As the molding apparatus, a lattice-shaped groove 20 (pitch: 20 mm, depth: 1.5 to 2 mm, width: 2 mm, groove depth / groove width = 0.75 to 1) is formed on the mold surface 10a as shown in Fig. The molding apparatus 2 provided with the formed upper mold 10A is used and the porous sheet 32 is not provided on the tray 30 provided on the bottom of the concave portion 12c of the lower mold 12, Was changed as shown in Table 1, an insulating plate was fabricated in the same manner as in Example 1.

[Example 4]

As a molding apparatus, a groove-like plate 10d having a lattice-shaped groove 20 (pitch: 20 mm, depth: 0.5 mm, width: 3 mm, groove depth / groove width = 0.17) A molding apparatus 4 having an upper mold 10C provided on the lower mold 12 side of the main body 10c was used and the molding conditions were changed as shown in Table 1, Thereby producing an insulating plate.

[Example 5]

The same molding apparatus as in Example 3 was used and a metal mesh (30 mesh length × 150 mesh length, manufactured by Ben Tech Co., Ltd.) was used instead of glass cloth # 470 as the porous sheets 32 and 34, An insulating plate was fabricated in the same manner as in Example 1, except for changing as shown.

[Example 6]

The same molding apparatus as in Example 4 was used and a metal mesh (30 mesh length × 150 mesh length, manufactured by Ben Tech Co., Ltd.) was used instead of glass cloth # 470 as the porous sheets 32 and 34, An insulating plate was fabricated in the same manner as in Example 1, except for changing as shown.

[Example 7]

The upper mold 10B having a plurality of through holes 22 (pitch: 20 mm, hole diameter (diameter): 1 mm) passing through from the mold surface 10a to the mold surface 10b as shown in Fig. The porous sheet 32 is not provided on the tray 30 provided on the bottom of the concave portion 12c of the lower die 12 and the molding conditions are shown in Table 1 A heat insulating plate was produced in the same manner as in Example 1,

[Examples 8 to 11]

An insulating plate was produced in the same manner as in Example 1 except that the porous sheets 32 and 34 were not used and the molding conditions were changed as shown in Table 1. [

Table 1 shows molding conditions and evaluation results of each example.

As shown in Table 1, in Examples 1 to 7 in which the press molding was performed with the porous sheet interposed between the upper mold and the heat insulating material and between the lower mold and the heat insulating material so as to be in contact with the heat insulating material, cracking or expansion A heat insulating plate of a good quality without a heat treatment was obtained. Particularly, in Examples 3 to 6 in which grooves were formed on the mold surface in contact with the porous sheet in the upper mold, a heat insulating plate of good quality was obtained in a very short time.

On the other hand, in Examples 8 and 9 in which the porous sheet was not used, a heat insulating plate of good quality free from cracking or expansion was obtained, but the press time was long and the productivity deteriorated.

In Example 10 in which the porous sheet was not used and the pressing time was 20 minutes, the obtained heat insulating plate was expanded.

In Example 11 in which the porous sheet was not used and the pressing time was set to 15 minutes, the obtained heat insulating plate was cracked.

The heat insulating plate and the vacuum heat insulating material produced by the manufacturing method of the present invention can be applied to places where energy saving is required, and where warming, cold storage, or heat insulation is required. Specifically, for example, housing facilities such as walls, roofs, flooring, piping, and photovoltaic and thermal facilities of houses and buildings; Insulating and cooling areas such as thermostat, water heater, hot water tank, air conditioner, refrigerator, freezer, cold storage high / cold tank, vending machine, cooler box, cold cover, Electronic devices such as notebook computers, liquid crystal projectors, copying machines, batteries, fuel cells, and semiconductor devices; Moving objects such as cars, buses, trucks, cold stores, trains, lorries and ships; It is applicable to piping of plant.

1 to 6: Molding apparatus
10, 10A to 10C, 40:
12, 12A, 50: Lower mold
32, 34, 62, 64: Porous sheet
16: Clearance
18: clearance
20, 24: Home
22: Through hole
42, 56: molded plate

Claims

A method of manufacturing an insulating plate having a molding step of press-molding a heat insulating material containing powder into a plate shape by a molding apparatus having a top mold and a bottom mold,
Wherein the press molding is performed in a state in which the porous sheet is interposed between the upper mold and the heat insulating material and between the lower mold and the heat insulating material or both of the lower mold and the heat insulating material so as to be in contact with the heat insulating material.

The heat insulating plate according to claim 1, wherein either or both of the upper and lower molds are in contact with the porous sheet interposed between the upper and lower molds and the heat insulating material, and grooves are formed on the mold surface in contact with the porous sheet Gt;

3. The method of manufacturing an insulating plate according to claim 2, wherein the ratio of the depth to the width of the groove formed in the mold surface contacting with the porous sheet (groove depth / groove width) is 0.1 or more.

4. The porous sheet according to any one of claims 1 to 3, wherein either or both of the upper and lower molds are in contact with the porous sheet interposed between the upper and lower molds and the heat insulating material, Wherein the porous chain is produced by the method.

5. The heat insulating material according to claim 4, wherein at least one of the upper and lower molds is in contact with the porous sheet interposed between the heat insulating material and the heat insulating material, Wherein a plurality of through holes are formed.

The method of manufacturing an insulating plate according to any one of claims 1 to 5, wherein the heat insulating material further comprises a binder.

7. The method of manufacturing an insulating plate according to any one of claims 1 to 6, wherein the heat insulating material further comprises fibers.

The method of producing an insulating plate according to any one of claims 1 to 7, wherein an insulating plate having a density of 0.15 to 0.35 g / cm 3 is obtained.

The method of manufacturing an insulating plate according to any one of claims 1 to 7, wherein the heat insulating plate is a core material of a vacuum heat insulating material.

A process for producing a vacuum insulation material, comprising the steps of: obtaining an insulating plate by the process for producing an insulating plate according to claim 9; and vacuum-sealing the obtained insulating plate in an outer bag.