JP2015161049A - Non-woven thermal insulating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal insulating material having high thermal insulating performance and generally being free of lint.SOLUTION: The present long-fiber non-woven insulating material is composed of long fiber. The long fiber includes thick fiber with a relatively thick fineness and fiber with a relatively thin fineness. The center of fineness distribution of the thick fiber is twice or more of the center of fineness distribution of the thin fiber. The fiber with the relatively thick fineness and the fiber with the relatively thin fineness make fiber bundles that are intertwined in a spiral shape. Since the fiber bundle formed by the fibers has a number of minor spaces that do not collapse even if a pressure is applied, the fiber bundle has high thermal insulating performance, and the thick fiber makes a skeleton, prevents flattening, can form a bulk and highly shape-retaining seat, and can achieve strength, bulkiness and high thermal insulating performance by adhering to and intertwining intersections of the thick fiber and of the thin fiber.

Description

  The present invention relates to a nonwoven fabric heat insulating material. In more detail, it is related with the nonwoven fabric heat insulating material comprised with a long fiber.

  Thermal insulation materials are used in various fields such as clothing materials, building materials, civil engineering materials, and vehicle materials. Conventionally, heat insulating materials using polyester fibers, polypropylene fibers, and the like are known. For example, Patent Document 1 proposes a nonwoven fabric sheet in which long fibers and short fibers are combined.

JP 2006-506551 A

  However, the conventional product proposed in Patent Document 1 has a problem in heat insulation, and further, since single fibers are used, there is a problem that falling fibers are easily generated, and these improvements are demanded. It was.

  In order to solve the above-described conventional problems, the present invention provides a heat insulating material that has high heat insulating properties and is less likely to cause dropped fibers.

  The non-woven fabric heat insulating material of the present invention is a non-woven heat insulating material composed of long fibers, wherein the long fibers include relatively thick fibers and relatively fine fibers, and the fineness distribution center of the thick fibers. Is more than twice the fineness distribution center of the thin fibers, and the relatively fine fibers and the relatively fine fibers are fiber bundles that are spirally entangled.

  The present invention is composed of long fibers, the long fibers include relatively thick fibers and relatively thin fibers, and the fine fiber distribution center is 2 of the fine fiber distribution centers. By having a fiber bundle in which the relatively fine fibers and the relatively fine fibers are spirally entangled with each other, it has high heat insulation and bulkiness, and there is a problem of short fibers falling off. There is no cost. That is, the fiber bundle formed by the relatively fine fibers and the relatively fine fibers has a lot of minute space that cannot be crushed even when pressure is applied, and thus has high heat insulating properties. Therefore, a bulky and highly shape-retaining sheet can be formed, and the intersections of thick fibers and thin fibers can be bonded or entangled to exhibit strength, bulkiness, and high heat insulation.

1A-B are photographs of a constituent fiber scanning electron microscope (SEM Hitachi scanning microscope S-2600N, magnification of 300 times) of the long-fiber nonwoven fabric obtained in one example of the present invention. FIG. 2 is a still image of a high-speed camera (Phantom MiroeX4 manufactured by Vision Research, USA) of a fiber bundle that is spun in one embodiment of the present invention and intertwined and spirally flies in the air. FIG. 3A is a schematic cross-sectional view of a long-fiber nonwoven fabric obtained in one example of the present invention, and FIG. 3B is a schematic cross-sectional view of a long-fiber nonwoven fabric of another example of the present invention. FIG. 4A is a schematic explanatory view of a spinning machine used in an embodiment of the present invention, and FIGS. 4B-D are schematic cross-sectional explanatory views of a yarn-proof cap portion. FIG. 5A is an explanatory diagram of an adiabatic measurement device according to an embodiment of the present invention. FIG. 6 is a heat insulation comparison graph when the thickness of the example of the present invention and the comparative example is 10 mm. FIG. 7 is a heat insulation comparison graph when the thickness of the example of the present invention and the comparative example is 15 mm.

  The present invention is a nonwoven fabric composed of long fibers. Long fibers can be produced by the melt blow method. The manufacturing cost of the melt blow method is low. An electrospinning method may be used in combination with the meltblowing method. The long fibers include fibers having relatively large fineness and fibers having relatively fineness, and the fineness distribution center of the thick fibers is more than twice the fineness distribution center of the thin fibers. Fibers produced by the melt-blowing method and / or electrospinning method have non-uniform fineness, but thin fibers preferably have a fineness distribution center of 10 μm or less. More preferably, it is 5.0 μm or less, and particularly preferably 3.0 μm or less. The fineness distribution center is observed by a photograph with a magnification of 300 to 3000 using a scanning electron microscope (SEM), and is a central value obtained by measuring 50 measurements.

  The fine fibers are preferably non-divided fibers. That is, it is a fiber that is produced by the melt-blowing method and / or the electrospinning method, and is a fiber that is not subjected to a splitting process. Even if the split fiber is split, it becomes a fiber bundle in which the fibers are bundled. However, the split fiber is formed of fibers parallel to the longitudinal direction of the fiber, and there is no entanglement between the fibers. In addition, there is a problem that costs increase.

  Thick fibers and thin fibers have different melting points, and thick fibers preferably have a relatively high melting point. This is because the thick fibers in the nonwoven fabric become a skeleton to prevent sag and form a bulky and highly shape-retaining sheet.

  If the material of the fiber which comprises a nonwoven fabric is thermoplastic, there will be no restriction | limiting in particular, General resin will be used. For example, a thermoplastic resin such as polyester or a copolymer thereof or a mixture thereof, specifically polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTMT), isophthalic acid, phthalic acid, etc. May be a polymer, a polyamide or a copolymer thereof, or a mixture thereof, or a polyolefin, a copolymer thereof, or a mixture thereof. For example, polypropylene obtained by random copolymerization of polyethylene (PE), polypropylene (PP), α-olefin, ethylene, or the like may be used. Moreover, you may consist of resin which mixed the polyester-type resin or the polyamide-type resin, and the olefin resin. Further, it may be made of a thermoplastic resin such as polyvinyl chloride, polystyrene, polyurethane, polylactic acid, polyphenylene sulfide, polyamideimide, or polyacetal.

  The thick fiber is preferably polyester. Polyester includes polyethylene terephthalate (PET), polytrimethylene terephthalate (PTMT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN) and the like. Of these, PET and PBT are preferable.

A fuzz preventing layer is preferably formed on at least one surface of the long-fiber nonwoven fabric of the present invention. In this way, surface fibers can be prevented from fuzzing and caught, and the handleability is improved. The fuzz-preventing layer may be any layer formed by surface processing such as a thermocompression bonding layer, a fried layer, or a resin layer, or a woven fabric, knitted fabric, spunbonded nonwoven fabric or the like placed on the surface and integrated. The integration of the long fiber nonwoven fabric and the fuzz preventing layer includes melt holes in the thickness direction, heat laminating, frame laminating, processing with an adhesive, and hydroentanglement. When using a spunbonded nonwoven fabric, it is preferable to integrate with a melt hole in the thickness direction. The weight (unit weight) per unit area of the spunbonded nonwoven fabric is preferably 5 to 100 g / m ² , more preferably 10 to 50 g / m ² . The melt hole in the thickness direction can be formed by pin sonic processing using a high frequency roller.

Basis weight of the long fiber nonwoven fabric of the present invention is preferably 10~10000g / m ^2, more preferably 50~5000g / m ^2, particularly preferably from 100 to 1000 g / m ^2. Apparent density is preferably 0.001~0.30g / cm ^3, more preferably 0.005~0.20g / cm ^3, particularly preferably 0.01~0.10g / cm ^3.

  Next, the manufacturing method of the long fiber nonwoven fabric of this invention is demonstrated. The long fiber nonwoven fabric is obtained by melt-extruding at least two types of polymers having different melting points from a spinneret, blowing the extruded fibers with a pressure fluid, and forming the blown fibers into a sheet. A method of blowing a fiber extruded by a pressure fluid to form a sheet is called a melt blow method. An electrode may be disposed in the vicinity of the sheet forming portion or the spinneret, and a voltage may be applied between the electrode and the spinneret. The method of applying voltage is called electrospinning. When a voltage is applied, the molten polymer extruded from the spinneret is charged and spun in the corresponding electrode direction. At this time, by spinning at high speed with compressed air, the fiber bundle-like long fibers intertwined in a spiral shape of the present invention can be obtained.

  In melt spinning, at least two kinds of polymers having different melting points and incompatible with each other may be melt-extruded from the same spinneret. As a result, a polymer having a high melting point becomes a thick fiber, and a polymer having a low melting point becomes a thin fiber. At least two types of polymers having different melting points may be melt extruded from different spinnerets. Similarly, a polymer having a high melting point becomes a thick fiber and a polymer having a low melting point becomes a thin fiber. However, since the amount of extrusion can be controlled, the ratio between the thin fiber and the thick fiber can be controlled. The ratio of thin fibers to thick fibers is preferably 90 to 10:10 to 90, and more preferably 80 to 40:20 to 60, by mass ratio.

  Next, it demonstrates using drawing. FIG. 3A is a schematic cross-sectional view of the long fiber nonwoven fabric 15 obtained in one example of the present invention. This long-fiber nonwoven fabric 15 has a long-fiber layer 12 including thick and fine fibers, and a fusion hole 14 in the thickness direction by pin sonic processing using at least one surface of a spunbond nonwoven fabric layer 13 and a high-frequency roller. FIG. 3B is a schematic cross-sectional view of a long fiber nonwoven fabric 17 of another example. This long fiber nonwoven fabric 17 is obtained by subjecting at least one surface of a long fiber layer 12 containing thick fibers and fine fibers to a fried yarn, and 16 is a fried yarn layer. When the spunbond nonwoven fabric layer 13 or the fried layer 16 is provided, the surface fibers can be prevented from fuzzing and caught, and the handleability is improved.

  4A is a schematic explanatory view of the spinning machine 11 used in one embodiment of the present invention, and FIGS. 4B-D are schematic explanatory views of a spinneret portion of the spinning machine. A melt extruder 2 is installed on the base 1, and polymer chips are supplied from the hopper 3 in the direction of arrow 4. The polymer melt-extruded by the extruder 2 is extruded from a die nose (spinneret) 5 and blown forward by compressed air discharged radially from a gas slot 6 formed in the vicinity of the dienose (spinneret) 5. Fibers are entangled in a Karman vortex by air resistance to form a fiber bundle, thereby forming a fiber assembly 8. FIG. 2 is a still picture of a high-speed camera (Pantom MiraeX4 manufactured by Vision Research, Inc.) of a fiber bundle that entangles and flies in the air in a spiral shape. An arrow 7 in FIG. 4A indicates the direction of compressed air supply from the roots blower. The fiber assembly 8 blown forward is turned into a sheet on the take-up roller 9 and taken up. Reference numeral 10 denotes a wound long fiber nonwoven fabric. A metal net may be disposed in place of the take-up roller 9. A voltage of about 10 to 100 kV may be applied to the dynose (spinneret) 5 and the take-up roller 9 or the metal net. The pressure supply direction is set not only to the front of the die nozzle but also to an optimum angle for spinning such as straight and 45 degrees obliquely forward depending on the properties of the polymer. As an example, as shown in FIGS. 4B-D, one or more gas slots 6a, 6b, 6c, 6d may be arranged.

  Hereinafter, more specific description will be made using examples. In addition, this invention is not limited to the following Example.

<Thickness measurement>
Ten points were measured with a large snap gauge K-7 manufactured by Ozaki Seisakusho, a probe diameter of 100 mm, and a weight of 2.5 g / cm ² , and the display range was obtained.
<Insulation test>
The thermal insulation test apparatus 20 shown in FIG. 5 was placed in a thermostatic chamber 27 whose temperature was controlled at 20 ± 0.2 ° C., and the temperature of the heater 21 was adjusted to 80 ± 0.1 ° C. An aluminum plate 22 is placed on the heater 21, and a heat insulating material test sample 23 is placed thereon. Styrofoam heat insulating materials 24 a, 24 b and 24 c are placed around the aluminum plate 22 and the heat insulating material test sample 23. A heater-side temperature sensor 25 was inserted between the heat insulating material test sample 23 and a heat insulating material surface sensor 26 was inserted between the heat insulating material test sample 23 and the styrene foam heat insulating material 24c. The thickness of the heat insulating material test sample 23 of Examples and Comparative Examples was suppressed to 15 mm and 10 mm, and the surface temperature was measured every 10 seconds. Measurements were made continuously for 60 minutes after the surface temperature hardly changed, and the heat insulation performance was comparatively evaluated based on the average value.

Example 1
Polypropylene (manufactured by Sun Aroma Co., Ltd., trade name “PWH00N; hereinafter abbreviated as PWH”), MFR1750, 230 ° C., 2.1 kg, JISK6921-2) and polyethylene terephthalate (trade name “Biopellet EMC307” produced by Toyobo Co., Ltd.) , PET) were blended (PP: PET = 70: 30 by weight), supplied from the hopper 4 of the melt spinning apparatus shown in FIG. 4A, melt extruded from the melt extruder 2, and spun. The spinning temperature is 320 ° C., the extrusion amount of the polymer from the die nose (spinneret) 5 is 500 g / min, and 0.4 Mpa of compressed air is sprayed from the pores having a diameter of 1 mm to the die nose. Rolled up. The fine fiber has a fineness distribution center of 25 μm and a fine fiber has a fineness distribution center of 1.2 μm. The basis weight of the obtained long fiber nonwoven fabric was 440 g / m ² and the thickness was 24 to 26 mm.

The obtained long fiber nonwoven fabric is flattened, and a spunbond nonwoven fabric with a basis weight of 15 g / m ² is laminated on both the front and back surfaces of the nonwoven fabric, and the long fiber nonwoven fabric span is formed by melt holes in the thickness direction by pin sonic processing using a high frequency roller. Bonded nonwoven fabric was integrated. The pitch interval of the melt holes in the thickness direction was 25 mm. The basis weight of the obtained long fiber nonwoven fabric was 450 g / m ² and the thickness was 20 to 22 mm.

  1A-B are photographs of a scanning electron microscope (SEM, 300 times magnification) showing the state of the constituent fibers of the obtained long-fiber nonwoven fabric. The thick fiber is polyethylene terephthalate (PET), and the thin fiber is polypropylene (PP). FIG. 3A is a schematic cross-sectional view of the long fiber nonwoven fabric 15 subjected to pin sonic processing.

(Example 2)
Polypropylene (PLB) (manufactured by Sun Aroma Co., Ltd., trade name “PWH00N; hereinafter abbreviated as PWH”), MFR1750, 230 ° C., 2.1 kg, JISK6921-2) of different melt spinning apparatuses (FIG. 4A). Supplied from the hopper 4, melt extruded from the melt extruder 2, and spun. At this time, the spun PLB and PWH were cross-combined at an angle of 30 degrees, and the long fiber nonwoven fabric 10 was wound up by the winding roll 9. The spinning temperature of PLB is 320 ° C., the amount of extrusion from the polymer die nose (spinner) 5 is 250 g / min, the pressure of blown air is 0.2 MPa, the spinning temperature of PWH is 330 ° C., and the polymer die nose (spinner cap). ) The extrusion amount from 5 was 500 g / min, and the blowout pressure of compressed air was 0.3 Mpa. The fine fiber distribution center of the resulting non-woven fabric (PLB) was 50 μm, and the fine fiber distribution center of the thin fiber (PWH) was 2.0 μm. The obtained long fiber nonwoven fabric had a basis weight of 455 g / m ² and a thickness of 24 to 26 mm.

(Example 3)
Polypropylene, PLB, and PWH were supplied from the hopper 4 of a separate melt spinning apparatus (FIG. 4A), melt extruded from the melt extruder 2, and spun. At this time, the spun PLB and PWH were cross-combined at an angle of 30 degrees, and the long fiber nonwoven fabric 10 was wound up by the winding roll 9. The spinning temperature of PLB is 320 ° C., the amount of extrusion from the polymer die nose (spinner) 5 is 250 g / min, the pressure of blown air is 0.2 MPa, the spinning temperature of PWH is 330 ° C., and the polymer die nose (spinner cap). ) The extrusion amount from 5 was 500 g / min, and the blowout pressure of compressed air was 0.2 MPa. The fine fiber distribution center of the obtained non-woven fabric thick fiber (PLB) was 50 μm, and the fine fiber distribution center of the thin fiber (PWH) was 3.0 μm. The basis weight of the obtained long fiber nonwoven fabric was 440 g / m ² and the thickness was 23 to 25 mm.

Example 4
Polypropylene, PLB, and PWH were supplied from the hopper 4 of a separate melt spinning apparatus (FIG. 4A), melt extruded from the melt extruder 2, and spun. At this time, the spun PLB and PWH were cross-combined at an angle of 30 degrees, and the long fiber nonwoven fabric 10 was wound up by the winding roll 9. The spinning temperature of PLB is 320 ° C., the amount of extrusion from the polymer die nose (spinner) 5 is 250 g / min, the pressure pressure of the compressed air is 0.3 Mpa, the spinning temperature of PWH is 330 ° C., the polymer die nose (spinning die) ) The extrusion amount from 5 was 500 g / min, and the blowout pressure of the compressed air was 0.4 Mpa. The fine fiber distribution center of the obtained non-woven fabric thick fiber (PLB) was 25 μm, and the fine fiber distribution center of the thin fiber (PWH) was 1.0 μm. The basis weight of the obtained long fiber nonwoven fabric was 460 g / m ² and the thickness was 23 to 25 mm.

The heat insulation test of the obtained long fiber nonwoven fabric was conducted. As a product of Comparative Example 1, a commercially available product manufactured by 3M, trade name “Synsalate”, TAI-4047, basis weight 450 g / m ² , thickness 21 to 23 mm) was used. The contents of Examples 1 to 4 and Comparative Example 1 are shown in Table 1.

(Remarks) The average surface temperature indicates the average temperature for 60 minutes after the start of measurement. A lower average temperature indicates better heat insulation.

  6 and 7 show thermal insulation graphs of the products of Examples 1 to 4 and the product of Comparative Example 1. 6 and 7 show that the lower the temperature, the better the heat insulation. The products of Examples 1 to 4 were higher in heat insulation than the product of Comparative Example 1.

DESCRIPTION OF SYMBOLS 1 Base 2 Melt extruder 3 Hopper 4 Polymer chip supply direction 5 Dye nose (spinneret)
6, 6a, 6b, 6c, 6d Gas slot 7 Pressure supply direction 8 Fiber assembly 9 Winding roll 10 Winded long fiber nonwoven fabric 11 Spinning machine 12 Long fiber layer 13 Spunbond nonwoven fabric layer 14 Melting hole 15, 17 Long fiber Non-woven fabric 16 Hair burning layer 20 Insulation test device 21 Heater 22 Aluminum plate 23 Insulation test sample 24a, 24b, 24c Styrofoam insulation 25 Heater side temperature sensor 26 Insulation material surface sensor 27 Constant temperature bath

Claims (6)

A non-woven heat insulating material composed of long fibers,
The long fibers include relatively thick fibers and relatively fine fibers,
The fineness distribution center of the thick fiber is more than twice the fineness distribution center of the thin fiber,
A nonwoven fabric heat insulating material characterized in that the relatively fine fiber and the relatively fine fiber are fiber bundles intertwined spirally.   The nonwoven fabric heat insulating material according to claim 1, wherein both the thick fiber and the thin fiber are non-divided fibers.   The nonwoven fabric heat insulating material according to claim 1 or 2, wherein the fine fibers have a fineness distribution center of 10 µm or less.   The nonwoven fabric heat insulating material according to any one of claims 1 to 3, wherein a fuzz preventing layer is formed on at least one surface of the nonwoven fabric.   The nonwoven fabric heat insulating material according to any one of claims 1 to 4, wherein a spunbonded nonwoven fabric is laminated on at least one surface of the nonwoven fabric and integrated by melt holes in the thickness direction.   The nonwoven fabric heat insulating material according to any one of claims 1 to 5, wherein at least one surface of the nonwoven fabric is baked.