JP2013231516A - Vacuum heat insulator, as well as refrigerator, hot water dispenser and residence including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulator that is easily handled, and a vacuum heat insulator that facilitates secondary processing.SOLUTION: A vacuum heat insulator 6 is formed of a core material 9 and a jacketing material 10 covering the core material 9, the core material formed of a fiber assembly 7 and having two heat transfer surfaces 8 facing each other, where the core material 9 is decompressed and sealed in the jacketing material 10. A thread 5 has a part exposed on one of the heat transfer surfaces, a part exposed on the other of the heat transfer surfaces, and a part buried in the fiber assembly, in the core material 9. The thread is tied in loop to penetrate the inside of the fiber assembly and to be exposed on the two heat transfer surfaces facing each other. As a result, the rigidity is imparted to the core material 9, whereby the planarity of the vacuum heat insulator is secured even after vacuum packing or an inside vacuum level inspection of the vacuum heat insulator.

Description

  The present invention relates to a vacuum heat insulating material in which a core material made of a fiber assembly is sealed under reduced pressure in a jacket material.

  In recent years, as a measure against global warming, which is a global environmental problem, there has been an active movement to promote energy saving, and for thermal and thermal equipment, there is a vacuum thermal insulation material that has excellent thermal insulation performance from the viewpoint of effective use of heat. It is becoming popular.

  A vacuum heat insulating material is a material in which a core material having a high gas phase volume ratio and a fine gap is inserted into a jacket material having a gas barrier property processed into a bag shape, and the core material is sealed under reduced pressure. is there.

  By making the gap diameter of the core material smaller than the mean free path of gas molecules under reduced pressure, the gas heat conduction component becomes small, and the influence of the convective heat transfer component can be ignored in a fine gap of about 1 mm. Become. Furthermore, since the influence of the radiation component is slight near room temperature, it is said that the heat conduction in the vacuum heat insulating material is dominated by the solid heat conduction component of the core material and the slightly remaining gas heat conduction component.

  The glass wool used as the core material must retain the void formed by the core material against the compressive load from the atmosphere. Therefore, the glass wool before being sealed under reduced pressure is very bulky because of its high gas phase volume ratio. . Moreover, since the rigidity is insufficient, it is very difficult to store the glass wool in the envelope material processed into a bag shape.

  Therefore, in order to solve the above-mentioned problem, a state in which a laminate formed by alternately laminating a large number of metal foils having a low emissivity and silica-based inorganic fiber sheets is compressed in the laminating direction to a density that withstands atmospheric pressure against vacuum A core material of a vacuum heat insulating material stitched with a thread made of a material having a low thermal conductivity has been proposed (see, for example, Patent Document 1).

  Hereinafter, the core material of the conventional vacuum heat insulating material will be described with reference to the drawings. FIG. 19 is a cross-sectional view illustrating a configuration of a core material of a conventional vacuum heat insulating material described in Patent Document 1.

  As shown in FIG. 19, the core material 1 of the conventional vacuum heat insulating material described in Patent Document 1 is formed by alternately laminating a large number of metal foils 2 and silica-based inorganic fibrous sheets 3 having a low thermal radiation rate. It is said that the laminated body 4 is stitched with a thread 5 made of a material having a low thermal conductivity in a state where the laminated body 4 is compressed in the laminating direction until it is pressured to atmospheric pressure against vacuum, and the handling property of the core material 1 can be improved. ing.

JP-A-8-121683

However, in the configuration of Patent Document 1, since the sewing method uses a hand stitch sewing machine that sews with one thread 5, the entanglement force between the thread 5 and the laminated body 4 that is the sewing object is weak, and the sewing is performed after sewing. When a bulky inorganic fiber having a compression rate of 80% to 90% is sewn, the yarn 5 is unwound from the laminate 4 due to the repulsive force of the inorganic fiber, and sufficient rigidity is not given to the laminate 4.

  When this laminated body 4 is used as the core material 1 of the vacuum heat insulating material, the amount of deformation in the thickness direction of the core material 1 increases before and after the vacuum packaging, so that the flatness of the vacuum heat insulating material after the vacuum packaging is not sufficiently secured. In addition, it is difficult to ensure the flatness of the vacuum heat insulating material even in the process of inspecting the degree of internal vacuum of the vacuum heat insulating material by reducing the pressure of a part or the whole of the vacuum heat insulating material.

  An object of this invention is to provide the vacuum heat insulating material which ensured planarity in view of the said conventional subject.

  Further, the vacuum heat insulating material of the present invention comprises at least a core material made of a fiber assembly and having two heat transfer surfaces facing each other, and a jacket material covering the core material, and the core material is the jacket material. A vacuum heat insulating material sealed in a vacuum, and having a portion exposed on one of the heat transfer surfaces of the core, a portion exposed on the other heat transfer surface, and a portion buried in the fiber assembly Is formed in an annular shape so as to be exposed to the two heat transfer surfaces that penetrate through the fiber assembly and face each other.

  Since the vacuum heat insulating material of the present invention has a small amount of deformation in the thickness direction of the fiber assembly before and after vacuum packaging, the flatness of the vacuum heat insulating material is ensured. Further, the flatness of the vacuum heat insulating material can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material and inspecting the internal vacuum degree of the vacuum heat insulating material.

Sectional drawing which shows the structure of the vacuum heat insulating material in Embodiment 1 of this invention. The top view which shows the heat-transfer surface of the core material used for the vacuum heat insulating material of the embodiment AA line sectional view of FIG. The top view which shows the heat-transfer surface of the core material used for the vacuum heat insulating material in Embodiment 2 of this invention BB sectional view of FIG. The top view which shows the heat-transfer surface of the core material used for the vacuum heat insulating material in Embodiment 3 of this invention CC sectional view of FIG. The top view which shows the heat-transfer surface of the core material used for the vacuum heat insulating material in Embodiment 4 of this invention DD sectional view of FIG. Sectional drawing which shows the structure of the vacuum heat insulating material in Embodiment 5 of this invention. The top view which shows the heat-transfer surface of the core material used for the vacuum heat insulating material of the embodiment EE sectional view of FIG. The top view which shows the heat-transfer surface of the core material used for the vacuum heat insulating material in Embodiment 6 of this invention FF sectional view of FIG. The top view which shows the heat-transfer surface of the core material used for the vacuum heat insulating material in Embodiment 7 of this invention GG sectional view of FIG. The top view which shows the heat-transfer surface of the core material used for the vacuum heat insulating material in Embodiment 8 of this invention HH line sectional view of FIG. Sectional drawing which shows the structure of the core material of the conventional vacuum heat insulating material shown by patent document 1

  1st invention consists of a core material which consists of a fiber assembly and which has two heat-transfer surfaces which oppose at least, and the jacket material which covers the said core material, and seals the said core material in the said jacket material under reduced pressure A yarn having a portion exposed to one of the heat transfer surfaces of the core, a portion exposed to the other heat transfer surface, and a portion buried in the fiber assembly. It is characterized in that it is connected in an annular shape so as to be exposed to the two heat transfer surfaces that penetrate through the assembly and face each other.

  When the thread forms an annular part at the time of sewing, the thread compresses the fiber assembly and continues to maintain the compressed state of the fiber assembly even after the annular part is formed, so that rigidity is imparted to the fiber assembly. Since the fiber assembly is compressed in the thickness direction, the deformation amount in the thickness direction of the fiber assembly is reduced before and after vacuum packaging.

  And by the said effect | action, since the deformation amount with respect to the thickness direction of a fiber assembly is small before and after vacuum packaging, the vacuum heat insulating material of this invention ensures the flatness of a vacuum heat insulating material. Further, the flatness of the vacuum heat insulating material can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material and inspecting the internal vacuum degree of the vacuum heat insulating material.

  The second invention is characterized in that, in the first invention, a single thread forms an annular shape.

  According to a third invention, in the first or second invention, the yarn is characterized in that one end of the yarn is connected to the other end to form a ring of the yarn. .

  According to a fourth aspect of the present invention, in the third aspect, the large diameter portion formed by connecting one end of the yarn and the other end is formed in the vicinity of the outer periphery of the fiber assembly. It is a feature.

  A fifth invention is obtained by laminating a plurality of fiber heat insulators in the first to fourth inventions.

  A sixth invention is a refrigerator including the first to fifth vacuum heat insulating materials.

  A seventh invention is a jar pot provided with the first to fifth vacuum heat insulating materials.

  The eighth invention is a house provided with the first to fifth vacuum heat insulating materials.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the same components as those of the above-described embodiments will be denoted by the same reference numerals, and detailed description thereof will be omitted. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing a configuration of a vacuum heat insulating material in Embodiment 1 of the present invention, FIG. 2 is a plan view showing a heat transfer surface of a core material used in the vacuum heat insulating material of the same embodiment, and FIG. It is sectional drawing at the time of cut | disconnecting the core material used for the vacuum heat insulating material of embodiment at the position of the AA line of FIG. 2, and seeing the cross section from the direction of the arrow.

As shown in FIGS. 1 to 3, the vacuum heat insulating material 6 of the present embodiment includes a core material 9 having two heat transfer surfaces 8 made of a fiber assembly 7, a moisture adsorbing material 12, and a core material. 9 and a covering material 10 covering the moisture adsorbing material 12, and the core material 9 is sealed in the covering material 10 under reduced pressure. The core material 9 includes a yarn 5 having a portion exposed on one heat transfer surface 8, a portion exposed on the other heat transfer surface 8, and a portion buried in the fiber assembly 7. A plurality of large-diameter portions 11 having a size that is difficult to move in the thickness direction in the fiber assembly 7 are exposed to the heat transfer surface 8 across a portion embedded in the fiber assembly 7. The large diameter portion 11 is formed by tying the yarn 5. The fiber assembly 7 is compressed in the thickness direction by the tension of the yarn 5.

  In the present embodiment, a plurality (six in FIG. 2) of threads 5 are sewn in parallel with each other at a predetermined interval and parallel to the longitudinal direction of the core material 9. And the large diameter part 11 is formed by the ball knot of the thread | yarn 5 for every part exposed to the heat-transfer surface 8. FIG. In the yarn 5, the portions penetrating through the fiber assembly 7 are distributed almost evenly, and the portions exposed to the heat transfer surface 8 are arranged perpendicular to the longitudinal direction of the core material 9.

In the present embodiment, polyethylene terephthalate having a fineness of 205 dtex is used as the yarn 5, a ring is formed at the end of the yarn 5, and the large diameter portion 11 is formed by passing the yarn 5 through the ring. After passing the other end of the yarn 5 through a fiber assembly 7 (thickness 150 mm) made of glass wool having a basis weight of 2,400 g / m ² , a ring is formed on the heat transfer surface 8 of the fiber assembly 7 with the yarn, The large diameter portion 11 was formed on the thread 5 by passing the thread through the ring. By repeating this operation, the core material 9 having the shape shown in FIGS. 2 and 3 was obtained.

  Since the thickness of the core material 9 was 15 mm and the handling was good, it was determined that the compression effect of the fiber assembly 7 in the present embodiment was sufficient.

  Next, the core material 9 was inserted into the bag-shaped outer cover material 10 together with the moisture adsorbing material 12 made of calcium oxide, and the vacuum heat insulating material 6 was obtained by sealing the interior of the outer cover material 10 under reduced pressure. When the thickness of the vacuum heat insulating material 6 was measured, it was 9.8 mm, and no deformation such as undulation was observed on the heat transfer surface of the vacuum heat insulating material 6, so that the flatness was judged to be good.

  In the core material 9 configured as described above, the large-diameter portion 11 having a cross-sectional area larger than that of the yarn 5 remains on the heat transfer surface 8 of the fiber assembly, and maintains the compressed state of the fiber assembly 7 even after sewing. In order to continue, the fiber assembly 7 is given rigidity. Accordingly, since the vacuum heat insulating material 6 using the fiber assembly 7 is compressed in the thickness direction, the amount of deformation in the thickness direction of the fiber assembly 7 is reduced before and after vacuum packaging, and the plane of the vacuum heat insulating material 6 is reduced. Sex is secured. Further, the flatness of the vacuum heat insulating material 6 can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material 6 and inspecting the internal vacuum degree of the vacuum heat insulating material 6.

  Furthermore, as compared with the main sewing method using the upper and lower two threads, the number of threads buried in the fiber assembly 7 is reduced, and the incidental effect that the thermal bridge is reduced occurs.

(Embodiment 2)
4 is a plan view showing the heat transfer surface of the core material used in the vacuum heat insulating material in Embodiment 2 of the present invention, and FIG. 5 shows the core material used in the vacuum heat insulating material of the same embodiment in FIG. It is sectional drawing at the time of cut | disconnecting in the position of B line and seeing the cross section from the direction of the arrow.

As shown in FIGS. 4 and 5, the vacuum heat insulating material 6 of the present embodiment has two heat transfer surfaces 8 made of a fiber assembly 7 and facing each other, like the vacuum heat insulating material 6 of the first embodiment. The core material 9 includes a core material 9, a moisture adsorbing material 12, and a jacket material 10 that covers the core material 9 and the moisture adsorbing material 12. The core material 9 is sealed in the jacket material 10 under reduced pressure. The core material 9 includes a yarn 5 having a portion exposed on one heat transfer surface 8, a portion exposed on the other heat transfer surface 8, and a portion buried in the fiber assembly 7. The large-diameter portion 11 having a size that is difficult to move in the thickness direction in the fiber assembly 7 is exposed to the heat transfer surface 8 with a portion buried in the fiber assembly 7 interposed therebetween. The fiber assembly 7 is compressed in the thickness direction by the tension of the yarn 5.

In this embodiment, a nylon resin having a diameter of 0.5 mm is used as the thread 5 and is bent using a jig called a tag gun so that the other end of the thread 5 is a straight line. A fiber assembly 7 (thickness 150 mm) made of 400 g / m ² of glass wool was penetrated from one heat transfer surface 8 to the other heat transfer surface 8. By repeating this operation so as to form a staggered pattern on the heat transfer surface 8 of the core material 9, the core material 9 having the shape shown in FIGS. 4 and 5 was obtained.

  Since the thickness of the core material 9 was 20 mm and the handling was good, it was determined that the compression effect of the fiber assembly 7 in the present embodiment was sufficient.

  Next, the core material 9 was inserted into the bag-shaped outer cover material 10 together with the moisture adsorbing material 12 made of calcium oxide, and the vacuum heat insulating material 6 was obtained by sealing the interior of the outer cover material 10 under reduced pressure. When the thickness of the vacuum heat insulating material 6 was measured, it was 10 mm, and no deformation such as undulation was observed on the heat transfer surface of the vacuum heat insulating material 6, so that the flatness was judged to be good.

  In the core material 9 configured as described above, the large-diameter portion 11 having a cross-sectional area larger than that of the yarn 5 remains on the heat transfer surface 8 of the fiber assembly, and maintains the compressed state of the fiber assembly 7 even after sewing. In order to continue, the fiber assembly 7 is given rigidity. Accordingly, since the vacuum heat insulating material 6 using the fiber assembly 7 is compressed in the thickness direction, the amount of deformation in the thickness direction of the fiber assembly 7 is reduced before and after vacuum packaging, and the plane of the vacuum heat insulating material 6 is reduced. Sex is secured. Further, the flatness of the vacuum heat insulating material 6 can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material 6 and inspecting the internal vacuum degree of the vacuum heat insulating material 6.

  Furthermore, as compared with the main sewing method using the upper and lower two threads, the number of threads buried in the fiber assembly 7 is reduced, and the incidental effect that the thermal bridge is reduced occurs.

(Embodiment 3)
6 is a plan view showing the heat transfer surface of the core material used for the vacuum heat insulating material in Embodiment 3 of the present invention, and FIG. 7 shows the core material used for the vacuum heat insulating material of the same embodiment in FIG. It is sectional drawing at the time of cut | disconnecting in the position of C line and seeing the cross section from the direction of the arrow.

  As shown in FIGS. 6 and 7, the vacuum heat insulating material 6 of the present embodiment has two heat transfer surfaces 8 made of a fiber assembly 7 and facing each other, like the vacuum heat insulating material 6 of the first embodiment. The core material 9 includes a core material 9, a moisture adsorbing material 12, and a jacket material 10 that covers the core material 9 and the moisture adsorbing material 12. The core material 9 is sealed in the jacket material 10 under reduced pressure. The core material 9 includes a yarn 5 having a portion exposed on one heat transfer surface 8, a portion exposed on the other heat transfer surface 8, and a portion buried in the fiber assembly 7. In the vicinity, a large-diameter portion 11 having a size that is difficult to move in the thickness direction in the fiber assembly 7 is exposed on the heat transfer surface 8 with a portion embedded in the fiber assembly 7 interposed therebetween. The large diameter portion 11 is formed by tying the yarn 5. The fiber assembly 7 is compressed in the thickness direction by the tension of the yarn 5.

  In the present embodiment, a plurality (six in FIG. 6) of threads 5 are half-reversely sewn in parallel to the longitudinal direction of the core material 9 while being separated from each other by a predetermined distance. And the large diameter part 11 is formed in the part exposed to the heat-transfer surface 8 of the both ends vicinity of the thread | yarn 5 by the ball knot of the thread | yarn 5. FIG. In addition, as for the thread | yarn 5, the location which penetrates the inside of the fiber assembly 7 is made to distribute substantially equally in a grid pattern.

In the present embodiment, nylon having a fineness of 110 dtex is used as the yarn 5, a ring is formed at the end of the yarn 5, and the large diameter portion 11 is formed by passing the yarn through the ring. After the other end of the yarn 5 is penetrated from one heat transfer surface 8 of the fiber assembly 7 (thickness 150 mm) made of glass wool having a basis weight of 2,400 g / m ² to the other heat transfer surface 8, the fiber assembly The yarn 5 was penetrated from the different places on the heat transfer surface 8 of 7 to the heat transfer surface 8 opposed to the yarn 5. After repeating this operation, finally, a ring is formed with the thread 5, and the large diameter portion 11 is formed by passing the thread 5 through the ring, and the core material 9 having the shape shown in FIGS. 6 and 7 is obtained. It was.

  Since the thickness of the core material 9 was 23 mm and the handling was good, it was determined that the compression effect of the fiber assembly 7 in the present embodiment was sufficient.

  Next, the core material 9 was inserted into the bag-shaped outer cover material 10 together with the moisture adsorbing material 12 made of calcium oxide, and the vacuum heat insulating material 6 was obtained by sealing the interior of the outer cover material 10 under reduced pressure. When the thickness of the vacuum heat insulating material 6 was measured, it was 11 mm, and no deformation such as undulation was observed on the heat transfer surface of the vacuum heat insulating material 6, so that the flatness was judged to be good.

  In the core material 9 configured as described above, the large-diameter portion 11 having a cross-sectional area larger than that of the yarn 5 remains on the heat transfer surface 8 of the fiber assembly, and maintains the compressed state of the fiber assembly 7 even after sewing. In order to continue, the fiber assembly 7 is given rigidity. Accordingly, since the vacuum heat insulating material 6 using the fiber assembly 7 is compressed in the thickness direction, the amount of deformation in the thickness direction of the fiber assembly 7 is reduced before and after vacuum packaging, and the plane of the vacuum heat insulating material 6 is reduced. Sex is secured. Further, the flatness of the vacuum heat insulating material 6 can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material 6 and inspecting the internal vacuum degree of the vacuum heat insulating material 6.

  Furthermore, as compared with the main sewing method using the upper and lower two threads, the number of threads buried in the fiber assembly 7 is reduced, and the incidental effect that the thermal bridge is reduced occurs.

(Embodiment 4)
FIG. 8 is a plan view showing the heat transfer surface of the core material used in the vacuum heat insulating material according to Embodiment 4 of the present invention, and FIG. 9 shows the core material used in the vacuum heat insulating material of the same embodiment in FIG. It is sectional drawing at the time of cut | disconnecting in the position of D line and seeing the cross section from the direction of the arrow.

  As shown in FIGS. 8 and 9, the vacuum heat insulating material 6 of the present embodiment has two heat transfer surfaces 8 made of fiber assemblies 7 and facing each other, like the vacuum heat insulating material 6 of the first embodiment. The core material 9 includes a core material 9, a moisture adsorbing material 12, and a jacket material 10 that covers the core material 9 and the moisture adsorbing material 12. The core material 9 is sealed in the jacket material 10 under reduced pressure. The core material 9 includes a yarn 5 having a portion exposed on one heat transfer surface 8, a portion exposed on the other heat transfer surface 8, and a portion buried in the fiber assembly 7. In the vicinity, a large-diameter portion 11 having a size that is difficult to move in the thickness direction in the fiber assembly 7 is exposed on the heat transfer surface 8 with a portion embedded in the fiber assembly 7 interposed therebetween. The large diameter portion 11 is formed by tying the yarn 5. The fiber assembly 7 is compressed in the thickness direction by the tension of the yarn 5.

In the present embodiment, polyethylene terephthalate having a fineness of 135 dtex is set as a thread 5 on a single-ring stitch sewing machine, and a nonwoven fabric sheet 13 made of polyethylene terephthalate as an anchoring member is sewn to form an empty ring. Next, a fiber assembly 7 (thickness 150 mm) made of glass wool having a basis weight of 2,400 g / m ² is sewed while the nonwoven fabric sheet 13 and the yarn 5 are continuous, and finally, only the yarn is entangled to form an empty ring. did. By repeating this operation, the core material 9 having the shape shown in FIGS. 8 and 9 was obtained.

  Since the thickness of the core material was 18 mm and the handling was good, it was determined that the compression effect of the fiber assembly 7 in the present embodiment was sufficient.

Next, the core material 9 was inserted into the bag-shaped outer cover material 10 together with the moisture adsorbing material 12 made of calcium oxide, and the vacuum heat insulating material 6 was obtained by sealing the interior of the outer cover material 10 under reduced pressure. When the thickness of the vacuum heat insulating material 6 was measured, it was 10.4 mm, and no deformation such as undulation was observed on the heat transfer surface of the vacuum heat insulating material 6, so that the flatness was judged to be good.

  In the core material 9 configured as described above, the large-diameter portion 11 having a cross-sectional area larger than that of the yarn 5 remains on the heat transfer surface 8 of the fiber assembly, and maintains the compressed state of the fiber assembly 7 even after sewing. In order to continue, the fiber assembly 7 is given rigidity. Accordingly, since the vacuum heat insulating material 6 using the fiber assembly 7 is compressed in the thickness direction, the amount of deformation in the thickness direction of the fiber assembly 7 is reduced before and after vacuum packaging, and the plane of the vacuum heat insulating material 6 is reduced. Sex is secured. Further, the flatness of the vacuum heat insulating material 6 can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material 6 and inspecting the internal vacuum degree of the vacuum heat insulating material 6.

  Furthermore, as compared with the main sewing method using the upper and lower two threads, the number of threads buried in the fiber assembly 7 is reduced, and the incidental effect that the thermal bridge is reduced occurs.

(Embodiment 5)
FIG. 10 is a cross-sectional view showing the configuration of the vacuum heat insulating material in Embodiment 5 of the present invention, FIG. 11 is a plan view showing the heat transfer surface of the core material used in the vacuum heat insulating material of the same embodiment, and FIG. It is sectional drawing at the time of cut | disconnecting the core material used for the vacuum heat insulating material of embodiment in the position of the EE line | wire of FIG. 11, and seeing the cross section from the direction of the arrow.

  As shown in FIGS. 10 to 12, the vacuum heat insulating material 6 of the present embodiment includes a core material 9 including two heat transfer surfaces 8 made of a fiber assembly 7, a moisture adsorbing material 12, and a core material. 9 and a covering material 10 covering the moisture adsorbing material 12, and the core material 9 is sealed in the covering material 10 under reduced pressure. The core material 9 includes a yarn 5 having a portion exposed to one heat transfer surface 8, a portion exposed to the other heat transfer surface 8, and a portion buried in the fiber assembly 7, and the fiber assembly 7. The fiber assembly 7 is compressed in the thickness direction by the tension of the yarn 5 and is connected in an annular shape so as to be exposed to the two heat transfer surfaces 8 that pass through the inside and face each other.

  In the present embodiment, the single thread 5 meanders so that most of the portion parallel to the longitudinal direction of the core material 9 is the majority, and finally returns to the starting point perpendicular to the longitudinal direction of the core material 9. Sewing on the course. Then, the ends of the yarn 5 are connected to form an annular shape.

In the present embodiment, low density polyethylene having a fineness of 120 dtex is set as a thread 5 on a hand stitch sewing machine, and a fiber assembly 7 (thickness 150 mm) made of glass wool having a basis weight of 2,400 g / m ² is shown in FIG. Then, the core material 9 having the shape of FIG. 12 was obtained by binding and sewing so that the portions penetrating the fiber assembly 7 were distributed almost evenly, and finally binding both ends of the yarn 5. .

  Since the thickness of the core material 9 was 25 mm and the handling was good, it was determined that the compression effect of the fiber assembly 7 in the present embodiment was sufficient.

  Next, the core material 9 was inserted into the bag-shaped outer cover material 10 together with the moisture adsorbing material 12 made of calcium oxide, and the vacuum heat insulating material 6 was obtained by sealing the interior of the outer cover material 10 under reduced pressure. When the thickness of the vacuum heat insulating material 6 was measured, it was 11 mm, and no deformation such as undulation was observed on the heat transfer surface of the vacuum heat insulating material 6, so that the flatness was judged to be good.

The core material 9 configured as described above compresses the fiber assembly 7 when the yarn 5 is tied in a ring shape, and maintains the compressed state of the fiber assembly 7 even after the yarn 5 is tied in a ring shape. In order to keep it held, rigidity is imparted to the fiber assembly 7. Since the fiber assembly 7 is compressed in the thickness direction, the amount of deformation in the thickness direction of the fiber assembly 7 is reduced after vacuum packaging, so that the flatness of the vacuum heat insulating material 6 is ensured. Further, the flatness of the vacuum heat insulating material 6 can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material 6 and inspecting the internal vacuum degree of the vacuum heat insulating material 6.

  Furthermore, as compared with the main sewing method using the upper and lower two threads, the number of threads buried in the fiber assembly 7 is reduced, and the incidental effect that the thermal bridge is reduced occurs.

(Embodiment 6)
FIG. 13 is a plan view showing the heat transfer surface of the core material used for the vacuum heat insulating material in Embodiment 6 of the present invention, and FIG. 14 shows the core material used for the vacuum heat insulating material of the same embodiment in FIG. It is sectional drawing at the time of cut | disconnecting in the position of F line and seeing the cross section from the direction of the arrow.

  As shown in FIGS. 13 and 14, the vacuum heat insulating material 6 of the present embodiment includes a core material 9 having two heat transfer surfaces 8 made of a fiber assembly 7 and facing each other, a moisture adsorbing material 12, and a core material. 9 and a covering material 10 covering the moisture adsorbing material 12, and the core material 9 is sealed in the covering material 10 under reduced pressure. The core material 9 includes a plurality of yarns 5 each having a portion exposed to one heat transfer surface 8, a portion exposed to the other heat transfer surface 8, and a portion buried in the fiber assembly 7. The yarn 5 penetrates the inside of the fiber assembly 7 from one heat transfer surface 8 and is exposed to the other heat transfer surface 8, and then penetrates the inside of the fiber assembly 7 from the other heat transfer surface 8. One end of the yarn 5 exposed on the heat surface 8 and remaining on one heat transfer surface 8 without penetrating the fiber assembly 7 and the fiber assembly 7 passing twice through the one end The other end of the yarn 5 exposed on the hot surface 8 is connected to form a ring of the yarn 5, and the fiber assembly 7 is compressed in the thickness direction by the tension of the yarn 5.

  It should be noted that the yarn 5 exposed on the heat transfer surface 8 forms a plurality of broken lines (five in FIG. 13) parallel to the longitudinal direction of the core material 9, and the portion penetrating through the yarn 5 fiber assembly 7 is almost the same. The portions that are evenly distributed in a grid pattern and exposed to the heat transfer surface 8 are arranged vertically in the longitudinal direction of the core member 9. The large diameter portion 11 formed by tying the yarn 5 is exposed only on one heat transfer surface 8.

In the present embodiment, nylon having a fineness of 110 dtex is used as the yarn 5, and the yarn 5 is used from one heat transfer surface 8 of the fiber heat insulator 7 (thickness 150 mm) made of glass wool having a basis weight of 2,400 g / m ² to the other. After passing through the heat transfer surface 8, the different heat transfer surface 8 is penetrated from one location to the other heat transfer surface 8, and both ends of the yarn 5 are bound to the shape shown in FIG. The core material 9 having a shape of 14 was obtained.

  Since the thickness of the core material was 22 mm and the handling was good, it was determined that the compression effect of the fiber assembly 7 in the present embodiment was sufficient.

  Next, the core material 9 was inserted into the bag-shaped outer cover material 10 together with the moisture adsorbing material 12 made of calcium oxide, and the vacuum heat insulating material 6 was obtained by sealing the interior of the outer cover material 10 under reduced pressure. When the thickness of the vacuum heat insulating material 6 was measured, it was 9.7 mm, and no deformation such as undulation was observed on the heat transfer surface of the vacuum heat insulating material 6, so that the flatness was judged to be good.

  The core material 9 configured as described above compresses the fiber assembly 7 when the yarn 5 is tied in a ring shape, and maintains the compressed state of the fiber assembly 7 even after the yarn 5 is tied in a ring shape. In order to keep it held, rigidity is imparted to the fiber assembly 7. Since the fiber assembly 7 is compressed in the thickness direction, the amount of deformation in the thickness direction of the fiber assembly 7 is reduced after vacuum packaging, so that the flatness of the vacuum heat insulating material 6 is ensured. Further, the flatness of the vacuum heat insulating material 6 can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material 6 and inspecting the internal vacuum degree of the vacuum heat insulating material 6.

Furthermore, as compared with the main sewing method using the upper and lower two threads, the number of threads buried in the fiber assembly 7 is reduced, and the incidental effect that the thermal bridge is reduced occurs.

(Embodiment 7)
15 is a plan view showing the heat transfer surface of the core material used for the vacuum heat insulating material in Embodiment 7 of the present invention, and FIG. 16 shows the core material used for the vacuum heat insulating material of the same embodiment in FIG. It is sectional drawing at the time of cut | disconnecting in the position of G line and seeing the cross section from the direction of the arrow.

  As shown in FIGS. 15 and 16, the vacuum heat insulating material 6 of the present embodiment includes a core material 9 including two heat transfer surfaces 8 made of a fiber assembly 7, a moisture adsorbing material 12, and a core material. 9 and a covering material 10 covering the moisture adsorbing material 12, and the core material 9 is sealed in the covering material 10 under reduced pressure. The core material 9 includes a plurality of yarns 5 each having a portion exposed to one heat transfer surface 8, a portion exposed to the other heat transfer surface 8, and a portion buried in the fiber assembly 7. The yarn 5 penetrates the inside of the fiber assembly 7 from one heat transfer surface 8 and is exposed to the other heat transfer surface 8, and then penetrates the inside of the fiber assembly 7 from the other heat transfer surface 8. One end of the yarn 5 exposed on the heat surface 8 and remaining on one heat transfer surface 8 without penetrating the fiber assembly 7 and the fiber assembly 7 passing twice through the one end The other end of the yarn 5 exposed on the hot surface 8 is connected to form a ring of the yarn 5, and the fiber assembly 7 is compressed in the thickness direction by the tension of the yarn 5.

  It should be noted that the yarn 5 exposed on the heat transfer surface 8 forms a plurality of broken lines (five in FIG. 13) parallel to the longitudinal direction of the core material 9, and the portion penetrating through the yarn 5 fiber assembly 7 is almost the same. A portion that is uniformly distributed in a zigzag shape and exposed to the heat transfer surface 8 is exposed only to the heat transfer surface 8 of the core material 9 in a zigzag shape, and a large diameter portion 11 formed by tying the yarn 5 is one side. Only the heat transfer surface 8 is exposed.

In the present embodiment, nylon having a fineness of 110 dtex is used as the yarn 5, and the yarn 5 is used from one heat transfer surface 8 of the fiber heat insulator 7 (thickness 150 mm) made of glass wool having a basis weight of 2,400 g / m ² to the other. After passing through the heat transfer surface 8, the different heat transfer surface 8 is penetrated from one location to the other heat transfer surface 8, and both ends of the yarn 5 are bound to form the shape shown in FIG. 15. The core material 9 which becomes the shape was obtained.

  Since the thickness of the core material 9 was 18 mm and the handling was good, it was determined that the compression effect of the fiber assembly 7 in the present embodiment was sufficient.

  Next, the core material 9 was inserted into the bag-shaped outer cover material 10 together with the moisture adsorbing material 12 made of calcium oxide, and the vacuum heat insulating material 6 was obtained by sealing the interior of the outer cover material 10 under reduced pressure. When the thickness of the vacuum heat insulating material 6 was measured, it was 10.1 mm, and no deformation such as undulation was observed on the heat transfer surface of the vacuum heat insulating material, so that the flatness was judged to be good.

  The core material 9 configured as described above compresses the fiber assembly 7 when the yarn 5 is tied in a ring shape, and maintains the compressed state of the fiber assembly 7 even after the yarn 5 is tied in a ring shape. In order to keep it held, rigidity is imparted to the fiber assembly 7. Since the fiber assembly 7 is compressed in the thickness direction, the amount of deformation in the thickness direction of the fiber assembly 7 is reduced after vacuum packaging, so that the flatness of the vacuum heat insulating material 6 is ensured. Further, the flatness of the vacuum heat insulating material 6 can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material 6 and inspecting the internal vacuum degree of the vacuum heat insulating material 6.

  Furthermore, as compared with the main sewing method using the upper and lower two threads, the number of threads buried in the fiber assembly 7 is reduced, and the incidental effect that the thermal bridge is reduced occurs.

(Embodiment 8)
FIG. 17 is a plan view showing a heat transfer surface of the core material used for the vacuum heat insulating material in Embodiment 8 of the present invention, and FIG. 18 shows the core material used for the vacuum heat insulating material of the same embodiment in FIG. Cut at the position of the H line,
It is sectional drawing at the time of seeing the cross section from the direction of an arrow.

  As shown in FIGS. 17 and 18, the vacuum heat insulating material 6 of the present embodiment includes a core material 9 including two heat transfer surfaces 8 made of a fiber assembly 7, a moisture adsorbing material 12, and a core material. 9 and a covering material 10 covering the moisture adsorbing material 12, and the core material 9 is sealed in the covering material 10 under reduced pressure. Further, the core material 9 has a plurality (seven in FIG. 17) having a portion exposed on one heat transfer surface 8, a portion exposed on the other heat transfer surface 8, and a portion buried in the fiber assembly 7. A plurality of (seven in FIG. 17) yarns 5 are provided, and are sewn together in parallel with the longitudinal direction of the core material 9, separated from each other by a predetermined distance, and at the end in the longitudinal direction of the core material 9. The ends of adjacent yarns 5 are connected to form a ring, and a plurality of rings of the yarn 5 are provided. The fiber assembly 7 is compressed in the thickness direction by the tension of the yarn 5.

In the present embodiment, a yarn made of polyethylene terephthalate having a fineness of 205 dtex and a fiber assembly 7 made of glass wool (thickness 150 mm) having a basis weight of 2,400 g / m ² were set on a hand stitch sewing machine. Next, the thread is sewn so as to be linear, and a plurality of threads located on the same side of the fiber assembly 7 are connected as shown in FIGS. 17 and 18 so that the thread 5 is bound in an annular shape. The material 9 was obtained. Since the thickness of the core material 9 was 21 mm and the handling was good, it was determined that the compression effect of the fiber assembly 7 in the present embodiment was sufficient.

  Next, the core material 9 was inserted into the bag-shaped outer cover material 10 together with the moisture adsorbing material 12 made of calcium oxide, and the vacuum heat insulating material 6 was obtained by sealing the interior of the outer cover material 10 under reduced pressure. When the thickness of the vacuum heat insulating material 6 was measured, it was 10.4 mm, and no deformation such as undulation was observed on the heat transfer surface of the vacuum heat insulating material 6, so that the flatness was judged to be good.

  The core material 9 configured as described above compresses the fiber assembly 7 when the yarn 5 is tied in a ring shape, and maintains the compressed state of the fiber assembly 7 even after the yarn 5 is tied in a ring shape. In order to keep it held, rigidity is imparted to the fiber assembly 7. Since the fiber assembly 7 is compressed in the thickness direction, the amount of deformation in the thickness direction of the fiber assembly 7 is reduced after vacuum packaging, so that the flatness of the vacuum heat insulating material 6 is ensured. Further, the flatness of the vacuum heat insulating material 6 can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material 6 and inspecting the internal vacuum degree of the vacuum heat insulating material 6.

  Furthermore, as compared with the main sewing method using the upper and lower two threads, the number of threads buried in the fiber assembly 7 is reduced, and the incidental effect that the thermal bridge is reduced occurs.

(Comparative example)
Polyethylene terephthalate having a fineness of 135 dtex was set as a thread on a hand stitch sewing machine, a fiber assembly (thickness 150 mm) made of glass wool having a basis weight of 2,400 g / m ² was sewn, and a core material was obtained. However, since the thread was released immediately after sewing, the thickness of the core material was restored to 85 mm and it was difficult to handle. Therefore, it was determined that the compression effect of the fiber assembly was insufficient in this comparative example.

  Next, the core material was inserted into a bag-shaped jacket material together with a moisture adsorbing material made of calcium oxide, and the vacuum jacket was obtained by sealing the inside of the jacket material under reduced pressure. When the thickness of this vacuum heat insulating material was measured, it was 9.5 mm, but it was judged that securing of flatness was not sufficient because the heat transfer surface of the vacuum heat insulating material was seen.

  In addition to the above-described embodiments, the following embodiments can be considered.

The vacuum heat insulating material is composed of at least a core material made of a fiber assembly and having two heat transfer surfaces facing each other, and a jacket material covering the core material, and the core material is sealed under reduced pressure in the jacket material. It is a vacuum heat insulating material and has a portion exposed on one of the heat transfer surfaces, a portion exposed on the other heat transfer surface, and a portion buried in the fiber assembly, and moves in the thickness direction within the fiber assembly. A plurality of large-diameter portions having a size difficult to do include at least one yarn provided in a portion exposed to the heat transfer surface across a portion embedded in at least one of the fiber assemblies, The fiber assembly is compressed in the thickness direction by the tension of the yarn.

  By providing a large-diameter portion having a larger cross-sectional area than the yarn on the heat transfer surface of the fiber assembly, the large-diameter portion continues to hold the compressed state of the fiber assembly after sewing, so that the fiber assembly has rigidity. Is granted. Since this fiber assembly is compressed in the thickness direction of the core material, it has the effect of reducing the deformation amount in the thickness direction of the fiber assembly before and after vacuum packaging.

  And by the said effect | action, since the deformation amount with respect to the thickness direction of a fiber assembly is small before and after vacuum packaging, the planarity of a vacuum heat insulating material is ensured. Further, the flatness of the vacuum heat insulating material can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material and inspecting the internal vacuum degree of the vacuum heat insulating material.

  In addition, although it does not specify in particular regarding the kind of fiber, conventionally well-known materials, such as inorganic fiber, such as glass wool, rock wool, an alumina fiber, and a metal fiber, and a polyethylene terephthalate fiber, can be utilized. In addition, when using a metal fiber, the metal fiber which consists of a metal comparatively excellent in heat conductivity among metals is not preferable.

  Among them, it is desirable to use glass wool having high elasticity of the fiber itself, low thermal conductivity of the fiber itself, and industrially inexpensive. Furthermore, since the thermal conductivity of the vacuum heat insulating material tends to decrease as the fiber diameter of the fiber decreases, it is desirable to use a fiber having a smaller fiber diameter, but the fiber cost is expected to increase because it is not versatile. Therefore, the glass wool which consists of an aggregate | assembly with a comparatively cheap average fiber diameter of about 3 micrometers-6 micrometers generally used as a fiber for vacuum heat insulating materials is more desirable.

  Here, the heat transfer surface refers to a surface having the largest area and a surface facing the surface when a fiber assembly is used as a fiber heat insulator. Further, when the vacuum heat insulating material is disposed on a relatively high temperature surface or a relatively low temperature surface for heat insulation, the vacuum heat insulating material is opposed to the relatively high temperature surface or the relatively low temperature surface on which the vacuum heat insulating material is disposed. It refers to the surface of the material and its opposite surface. Moreover, when using it laminating | stacking a some fiber heat insulator, the surface of each vacuum heat insulating material perpendicular | vertical with respect to the lamination direction and the surface which opposes it are pointed out.

  Here, the jacket material plays a role of maintaining the vacuum degree of the vacuum heat insulating material, and is a resin film in which metal foil and metal atoms are vapor-deposited as a gas barrier film as an inner layer and a heat-welded film as an inner layer. A surface protective film is laminated as the outermost layer.

  The heat welding film is not particularly specified, but a thermoplastic resin such as a low density polyethylene film, a linear low density polyethylene film, a high density polyethylene film, a polypropylene film, a polyacrylonitrile film, or a mixture thereof is used. Can be used.

  Gas barrier films include metal foils such as aluminum foil and copper foil, base materials such as polyethylene terephthalate films and ethylene-vinyl alcohol copolymer films, metals such as aluminum and copper, and metal oxides such as alumina and silica. The film etc. which vapor-deposited the thing can be used.

  Moreover, as a surface protective film, conventionally well-known materials, such as a nylon film, a polyethylene terephthalate film, a polypropylene film, can be used.

  In order to suppress the increase of gas heat conduction component due to the invasion of gas and water vapor, the adsorbent supplementing the gas and water vapor entering the vacuum heat insulating material, such as zeolite and calcium oxide, is sealed under reduced pressure together with the core material. It is desirable.

  In addition, the vacuum insulation material manufacturing method is not particularly specified, but it is obtained by folding back one outer cover material and thermally welding the heat-welded films located at the ends of the opposite outer cover materials. The core material is inserted into the bag-shaped jacket material, and the heat-welded films located at the openings of the bag-shaped jacket material are thermally welded under reduced pressure, or the heat-welded films are opposed to each other. The core material is inserted into a bag-shaped outer cover material obtained by arranging a single outer cover material and heat-welding the heat-welded films located at the ends of each outer cover material. The method of heat-welding the heat welding films located in the vicinity of the opening part of a shape-like outer covering material can be utilized.

  Here, a thread | yarn plays the role for compressing the aggregate | assembly of a fiber. The material of the yarn is not particularly specified, but natural fibers such as cotton and silk, polyethylene terephthalate, etc. Synthetic yarns such as nylon, polyethylene, and polypropylene, and inorganic yarns such as long glass fibers and long metal fibers can be used.

  However, for the purpose of securing the heat insulating effect of the heat insulating material, the purpose of suppressing the organic gas generated under reduced pressure, and the purpose of providing a heat insulating material having higher rigidity, an organic material made of a synthetic resin such as polyethylene terephthalate or nylon is used. It is more desirable to use fibers.

  Furthermore, although the shape of the yarn is not particularly specified, it has a monofilament composed of a single yarn, a twisted yarn composed of a plurality of yarns, a wooly yarn obtained by subjecting the twisted yarn to a bulky process, and elasticity. A rubber-like thread, a thread that shrinks when heated, a member to which a product tag in which a synthetic resin is molded into an I shape, and the like can be used.

  Further, a general sewing thread is coated with an oil agent on the surface of the thread for the purpose of improving the sliding of the thread during sewing and for preventing the thread breakage in the twisting process. When this oil-coated yarn is applied to a fiber heat insulator, it causes generation of organic gas under reduced pressure. Therefore, it is preferable that the amount of oil is as small as possible. In addition, since the above-mentioned monofilament does not have a twisting process, the adhesion amount of the oil agent is 0.1% to 0.3% in weight ratio, which is smaller than that of the twisted thread. Therefore, it is more desirable to apply a monofilament to the present invention.

  Furthermore, a coloring agent is given to a general sewing thread in view of design properties. When the yarn to which the colorant is applied is applied to the fiber heat insulator, as in the case of the above-described oil agent, an organic gas is generated under reduced pressure, and thus a generated yarn to which no colorant is applied is more desirable.

  Here, the large diameter portion refers to a portion that is provided in the yarn and has a larger cross-sectional area than the yarn embedded in the fiber assembly. The type and shape of the large-diameter part are not particularly specified. A formed thread, a thread anchored to another member, or a thread entangled with another member can be considered.

  Further, the large-diameter portion is a vacuum heat insulating material characterized by being formed only by yarn, and in addition to the function and effect of the first invention, a large-diameter portion is not required for forming a large-diameter portion. It has the effect | action which can suppress the magnitude | size of a diameter part to required minimum.

  The large diameter portion is a vacuum heat insulating material that is formed by an empty ring of yarn, and since the empty ring that becomes the large diameter portion has a plurality of knots of yarn, the large diameter portion Even when a part of the fiber assembly is buried in the fiber assembly, the other large-diameter portions continue to maintain the compressed state of the fiber assembly, so that the fiber assembly has an effect of giving rigidity.

  Here, the empty ring refers to a thread seam formed without a fiber assembly. In addition, an empty ring is a fiber assembly formed by a lock stitch, a single ring stitch, or a double ring stitch.

  Further, the vacuum heat insulating material is provided with an anchoring member through which the yarn penetrates or entangles between the large diameter portion and the heat transfer surface, and the anchoring member serves as a wedge with respect to the fiber assembly. In order to achieve, it has the effect | action that the rigidity provided to the fiber assembly becomes stronger.

  Here, the anchoring member plays a role of fixing the yarn. Although the thread fixing method is not particularly specified, the thread is entangled with the mooring member, or the thread is arranged so as to penetrate the mooring member, and is larger than the through hole of the mooring member. A method of forming the diameter portion with a thread is conceivable.

  Although the shape of the anchoring member is not particularly specified, various shapes such as a bar shape such as a wire, a sheet shape such as a film or a non-woven fabric, and a button shape having a hole are conceivable. However, the thickness of the mooring member is preferably within 1 mm for the purpose of ensuring the flatness of the vacuum heat insulating material and the purpose of suppressing damage to the jacket material.

  Moreover, since a thread | yarn becomes easy to get entangled in a nonwoven fabric when a nonwoven fabric is used as a mooring member, the magnitude | size of a large diameter part can be made small. In addition, since the effect | action which compresses a fiber assembly as a whole will be acquired if a film and a sheet | seat are provided in the whole heat-transfer surface, the effect which becomes easy to ensure the planarity of a vacuum heat insulating material will be acquired.

  Since the vacuum heat insulating material of the present invention has a small amount of deformation in the thickness direction of the fiber assembly before and after vacuum packaging, the flatness of the vacuum heat insulating material is ensured. Further, the flatness of the vacuum heat insulating material can be ensured also in the step of depressurizing a part or the whole of the vacuum heat insulating material and inspecting the internal vacuum degree of the vacuum heat insulating material. Therefore, the vacuum heat insulating material of the present invention can be used in any application to which a vacuum heat insulating material can be applied, such as a refrigerator, a jar pot, a rice cooker, a vending machine, and a house.

5 Yarn 6 Vacuum Insulating Material 7 Fiber Assembly 8 Heat Transfer Surface 9 Core Material 10 Outer Material 11 Large Diameter Part 13 Nonwoven Sheet (Mooring Member)

Claims (8)

A vacuum heat insulating material comprising at least a core material made of a fiber assembly and having two heat transfer surfaces facing each other, and a jacket material covering the core material, wherein the core material is sealed under reduced pressure in the jacket material. And
A yarn having a portion exposed on one of the heat transfer surfaces of the core, a portion exposed on the other heat transfer surface, and a portion buried in the fiber assembly passes through the fiber assembly and faces each other 2. A vacuum heat insulating material characterized in that it is connected in an annular shape so as to be exposed to the two heat transfer surfaces. The vacuum heat insulating material according to claim 1, wherein the vacuum heat insulating material is annular with a single thread. The vacuum heat insulating material according to claim 1 or 2, wherein one end of the yarn and the other end of the yarn are connected to form a yarn ring. The vacuum heat insulating material according to claim 3, wherein a large diameter portion formed by connecting one end portion and the other end portion of the yarn is formed in the vicinity of the outer periphery of the fiber assembly. . The vacuum heat insulating material as described in any one of Claim 1 to 4 which laminated | stacked the several fiber heat insulating body. The refrigerator provided with the vacuum heat insulating material as described in any one of Claim 1 to 5. A jar pot provided with the vacuum heat insulating material according to any one of claims 1 to 5. The house provided with the vacuum heat insulating material as described in any one of Claim 1 to 5.