Heat insulation cover member for preventing or suppressing dripping of condensed water, other heat mating pipe covering members and duct covering members, piping structures and duct covering structures using these, and method of using the heat insulation cover member for heat mating pipe covering members

Abstract

To suppress and prevent dew condensation water from dripping on a piping surface even when refrigerant piping of an air conditioner etc., is vertical piping.SOLUTION: A heat insulation cover member for dripping prevention or dripping suppression on dew condensation water that has non-woven fabric bonded to a surface of resin foam is characterized in that: the non-woven fabric is fixed on one surface of the resin foam by fusing or bonding; the non-woven fabric is formed of non-woven fabric which has highly water-absorptive resin fiber mixed with thermoplastic resin fiber by a predetermined amount; at least a part of the thermoplastic resin fiber is mutually fused or bonded; and the non-woven fabric includes 10 mass% or more and 80 mass% or less of the highly water-absorptive resin fiber and 20 mass% or more and 90 mass% or less of the thermoplastic resin fiber.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a heat-insulating cover member for preventing or suppressing the dripping of condensed water, other heat-exchanging pipe covering members and duct covering members, a piping structure and a duct covering structure using these, , and and a method of using the heat-insulating cover member for a heat-exchanging pipe covering member.

Background Art

[0002] In recent years, due to the heat wave and the improvement of air conditioner efficiency, problems caused by the dripping of condensed water generated in concealed refrigerant pipes have become apparent. This is a problem that peeling and blackening can occur on the ceiling cross or the floor due to the dripping of condensed water. As a cover member for the pipes of such a heat exchanger, a material obtained by laminating a polyethylene or polypropylene film on at least one surface of a polyethylene foam and embossing the surface of the laminated resin foam has been used as a heat-insulating cover member for pipes such as refrigerants of air-conditioning equipment. However, in the case of such a heat-insulating cover member, condensation occurs on the surface of the heat-insulating cover member used on the outer periphery of the refrigerant pipe. This condensed water drips into the pipe space behind the ceiling or the like, which causes mold to occur in the pipe space such as behind the ceiling. Although the purposes and applications of the countermeasures are different, the following inventions can be cited as reference cover members and non-woven fabric technologies.

[0003] In the invention of Patent Document 1, a covering body in which a covering material of a desired thickness is accommodated in a covering layer around a metal duct body, a synthetic resin flexible pipe, an aluminum flexible pipe, a duct body or a flexible pipe having a covering layer around it is covered around the duct body or the flexible pipe, etc., and a highly water-absorbent polymer water-absorbing material is infiltrated into a dew condensation prevention or suppression-capable heat-insulating and cold-insulating covering material such as glass cloth, non-woven fabric wool, or cotton-like pulp of a desired thickness accommodated in the covering body to increase the water retention rate and eliminate dew condensation. A pipe structure such as a duct having a dew condensation prevention or suppression-capable heat-insulating and cold-insulating covering layer is disclosed. The structure of Patent Document 1 is a pipe structure in which a heat-insulating and cold-insulating coating layer such as glass cloth, non-woven wool, or cotton pulp as the heat-insulating and cold-insulating coating layer is covered with a surface coating layer containing a highly fire-resistant material such as fluororesin or zirconium to enhance fire resistance. The pipe structure of Patent Document 1 uses a non-woven fabric containing a highly water-absorbent resin to cover the surface of the structure with the non-woven fabric. However, it is neither a structure in which a non-woven fabric is bonded to the surface of a polyethylene-based resin foam nor a structure using highly water-absorbent resin fibers as in the present invention. Therefore, the structures of the coating materials are different between the two. Accordingly, there is no description regarding preventing the condensation water from aggregating at a predetermined location and promoting the evaporation of moisture by diffusion, such as the water retention parameter of the non-woven fabric. impregnation It is a structure in which the surface of the structure is covered with a non-woven fabric using a non-woven fabric containing a highly water-absorbent resin. However, it is neither a structure in which a non-woven fabric is bonded to the surface of a polyethylene-based resin foam nor a structure using highly water-absorbent resin fibers as in the present invention. Therefore, the structures of the coating materials are different between the two. Accordingly, there is no description regarding preventing the condensation water from aggregating at a predetermined location and promoting the evaporation of moisture by diffusion, such as the water retention parameter of the non-woven fabric.

[0004] Patent Document 2 discloses a sheet in which an outer skin made of a synthetic resin sheet is laminated on the surface of a rectangular thermoplastic resin foam, and the outer skin of the laminated sheet is provided so as to protrude from one end of the foam sheet at the end of the foam sheet to form an overlap portion. This overlap portion has a structure laminated via a release sheet so as to be adhesively bonded with an adhesive layer applied to the outer skin, and a part of the adhesive layer is covered with a protective layer. A heat-insulating pipe cover is disclosed. Here, the invention of Patent Document 2 aims to provide a heat-insulating pipe cover, a coating method using the same, and a heat-insulating pipe coating structure having a structure that can be easily constructed by the synergistic effect of the protective layer and the release sheet even when working gloves are worn during the construction of attaching the heat-insulating pipe cover to a pipe, and that significantly improves the heat deterioration of the cut portion after construction. The purpose of the heat-insulating pipe cover of Patent Document 2 is to simplify the attachment of the heat-insulating pipe cover and improve heat resistance, and not to prevent or suppress the dripping of condensation water. Therefore, only a thermoplastic resin film or a thermoplastic resin sheet is disclosed as the protective layer in the specification, and there is no description regarding a non-woven fabric at all. That is, although Patent Document 2 describes a non-woven fabric as an example of a material that may be used as a protective layer or a release sheet, it treats a thermoplastic resin sheet resin or a tree resin film without water absorption and materials with water absorption such as paper, woven fabric, and non-woven fabric in the same category. Since any material can be used as long as it can be used as a surface coating material for forming a protective layer, there is no description regarding the structure of the non-woven fabric or the characteristics of the material. Although the invention of Patent Document 2 discloses a heat-insulating pipe cover using a foam, it is for the purpose of facilitating construction and preventing heat deterioration at the cut of the foam (joint at the end), and is not a heat-insulating cover member for preventing or suppressing the dripping of condensed water by laminating a non-woven fabric in which a highly water-absorbent resin fiber is mixed with a synthetic fiber on the surface of the foam. Moreover, no specific configuration regarding the non-woven fabric is disclosed at all, and it is treated in the same category as a resin film as a surface coating material for the protective layer, and it is not an invention intended to impart special functions to the non-woven fabric in consideration of the structure and material properties of the non-woven fabric. Therefore, Patent Document 2 does not disclose at all, nor is there any motivation to balance the water retention and diffusion evaporation properties of the non-woven fabric by the water retention parameter of the non-woven fabric that prevents the aggregation of condensed water and promotes the evaporation of moisture by diffusion. cover Patent Document 3 combines various films and non-woven fabrics and studies the heat-insulating effect and water absorption of the heat-insulating cover member. As a result, a porous film made of polyolefin and a non-woven fabric containing a highly water-absorbent polymer are laminated, and water droplets dripping on the film surface are made to drip from the holes of the porous film, and a water-absorbent heat-insulating cover member for agriculture characterized in that the condensed water absorption rate is within 60 seconds is disclosed.

[0005] The water-absorbent heat-insulating cover member for agriculture in Patent Document 3 is mainly laid on top of the strawberries in the strawberry ridges in greenhouse cultivation so that strawberries can bear fruit on it, and it suppresses the evaporation of moisture from the ground, and is an invention that mainly emphasizes water retention. ​The heat-insulating cover member of Patent Document 3 is an invention of a heat-insulating material for agriculture in which a non-woven fabric containing a superabsorbent polymer is laminated on a porous resin film. In order to maintain the quality of strawberries, the absorption rate of water droplets dripping on the film surface is within 60 seconds to prevent the evaporation of condensed water and retain the condensed water. However, it does not achieve the balance between the retention and evaporation of condensed water by the non-woven fabric as in the present invention. That is, the invention of Patent Document 3 covers the surface of the non-woven fabric with a porous resin film, so that the non-woven fabric retains condensed water and at the same time prevents the evaporation of condensed water to prevent the quality of strawberries from deteriorating. The invention of Patent Document 3 has a laminated structure of a porous resin film and a non-woven fabric, not a laminated structure of a resin foam and a non-woven fabric, and the structures of the two invention products are different. Furthermore, in the invention of Patent Document 3, since the surface is covered with a resin film, although it may be easy to retain the absorbed moisture, the coating layer of the resin film prevents evaporation, so there is an inhibitory factor for use for the purpose of promoting evaporation for preventing condensation as in the present application. Therefore, there is no description regarding preventing the aggregation of condensed water like the moisture retention parameter of the non-woven fabric and promoting the evaporation of moisture by diffusion. Also, in Patent Document 3, the mixing ratio of Veroshis, which is a superabsorbent resin fiber, is in the range of 1% to 10% by mass, whereas in the product of the present invention, as will be described later, the mixing ratio of the superabsorbent resin fiber in the layer containing the superabsorbent resin fiber is 10% to 80% by mass, which is also different.

[0006] Patent Document 4 describes a multifunctional sheet-like absorber composed of three components: an absorption layer mainly composed of a superabsorbent resin, a non-woven fabric-like base material supporting the superabsorbent resin, and a binder component that binds between the superabsorbent resins and between the superabsorbent resin and the base material. The invention of this Patent Document 4 is a multifunctional absorber having a multilayer structure and is used for absorber products such as baby diapers, adult diapers, female incontinence products, blood absorbents, breast milk pads, etc. The absorbent sheet of Patent Document 4 has a multi-functional sheet-like absorbent body having a complex structure characterized in that on the surface of the sheet-like absorbent body, an absorption region phase (phase A) composed of an absorption layer and a non-woven fabric-like base material carrying the same, and a diffusion / aquisition region phase (phase B) composed only of the non-woven fabric-like base material with almost no superabsorbent resin are distributed so as to be mutually distinguishable. Patent Document 4 is a two-layer laminated non-woven fabric, one layer contains a superabsorbent resin, and the non-woven fabric laminated with this is composed of synthetic resin fibers. On the other hand, in the superabsorbent resin layer of the A layer of Patent Document 4, since granular superabsorbent resin is used, it is necessary to bind the non-woven fabric constituent fibers and the granular superabsorbent resin with a binder. However, in the present invention, since superabsorbent resin fibers are used, it is not necessary to use a binder due to the entanglement between the skeletal fibers and the superabsorbent resin fibers. The non-woven fabric layer of the B layer is composed of an aquisition layer that is bulky and has a high resilience value (elastic recovery rate) in order to improve the water permeability, and is intended for diffusion and acquisition of moisture. In contrast, the layer containing no superabsorbent resin of the present invention is intended to diffuse and evaporate moisture. Furthermore, it aims to balance the water retention and diffusion evaporation properties of the non-woven fabric by the water retention parameter of the non-woven fabric that prevents the aggregation of condensed water and promotes the evaporation of moisture by diffusion. However, Patent Document 4 does not have such a description, and is different in that it aims at diffusion of moisture and acquisition by the superabsorbent resin layer. The structure of the non-woven fabric itself having water absorption is different, and In Patent Document 4, When only a non-woven fabric is used as the heat-insulating cover member, the heat-insulating effect by the resin foam cannot be obtained, which is different in that the amount of condensed water in the non-woven fabric layer increases.

[0007] Patent Document 5 discloses a water-absorbing composite body having a water absorption capacity gradient in the thickness direction, in which a first layer made of a non-woven fabric web mainly composed of synthetic fibers having surface wetting characteristics with respect to water and a second layer made of a morphologically stabilized superabsorbent polymer sheet having a significantly higher water retention degree than the first layer are integrated. In addition, Patent Document 5 states that the liquid supplied to the first layer is instantaneously received by the first layer, but quickly passes through without being retained therein and is sucked into the second layer and stably absorbed. Therefore, the first layer is always in a state of waiting for the next excretion and can be advantageously used in many applications including diapers and sanitary napkins. According to Patent Document 5, by connecting the layers of the multilayer sheet and fibrillating the main absorber layer of the second layer, the morphological stability of the nonwoven fabric with a laminated structure is improved, and it becomes possible to provide a sheet-like composite absorber that can maintain excellent morphological stability even after absorbing a liquid with extremely high liquid absorption efficiency. The sheet-like composite absorber obtained by laminating the nonwoven fabric of Patent Document 5 is formed from a nonwoven web mainly composed of synthetic fibers having surface wetting characteristics with respect to moisture in the first layer. The second layer is obtained by subjecting a composite nonwoven fabric obtained by binding precursor fibers to a skeleton mainly composed of polypropylene fibers by hydroentanglement to a high-absorbency treatment, thereby forming a highly water-absorbent polymer sheet with high moisture retention and morphological stability. As a result, the water-absorbing composite of Patent Document 5 has a water absorption capacity gradient between the first layer and the second layer. Due to this water absorption capacity gradient, the excreted liquid is instantaneously received by the first layer, but quickly passes through without being retained therein and is sucked into the second layer and stably absorbed. Patent Document 5 preferably has a higher permeability of the first layer to the second layer when viewed as a laminated structure, and there is no description regarding the diffusibility of the first layer in the surface direction of the nonwoven fabric. The invention of Patent Document 5 is applied to the refrigerant pipes of air conditioners and the like in the present invention in Unlike the heat-insulating cover member for preventing or suppressing the dripping of condensed water, it is an invention of a highly absorbent diaper composed only of a laminated structure nonwoven fabric, and the purposes of the two inventions are different. In addition, the two have a structural difference in whether they have a laminated structure of a resin foam and a nonwoven fabric or a structure composed only of a nonwoven fabric. Since the invention of the present application has a laminated structure of a resin foam and a nonwoven fabric, it is different from the invention of Patent Document 5, which is an invention of only a nonwoven fabric, in that the protective effect and heat insulation effect by the resin foam are superimposed. In addition, the water-absorbing resin fibers described in Patent Document 5 are described in the specification absorb In terms of the amount of water, it is not a superabsorbent resin having a water absorption capacity of 10 times or more of the self-weight defined in the present application. Furthermore, the present invention Regarding the non-woven fabric of the present invention , it is considered to balance the water retention and diffusion evaporation properties of the non-woven fabric according to the water retention parameter of the non-woven fabric that not only prevents the condensation of condensed water but also promotes the evaporation of moisture by diffusion. However, although the non-woven fabric of Patent Document 5 describes the water absorption capacity gradient between the first layer and the second layer and the water retention property of the second layer, there is no description regarding the action mechanism of diffusing and evaporating moisture, and it cannot be aimed at preventing condensation by promoting diffusion from the outer surface of the protection member and evaporating moisture.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0009] For refrigerant pipes and drain pipes of heat exchangers such as air conditioners, it is considered that a polyethylene resin foam with a polyethylene film laminated on the surface and the laminated surface embossed is used as a heat insulation cover member for covering these pipes. However, in this case, there is a problem of condensation when the use environment is severe. A method of preventing condensation by directly laminating a non-woven fabric containing a highly water-absorbent resin on a duct or pipe can be proposed. Instead of a polyethylene film laminated on the surface of a foam excellent in heat insulation, a structure in which a non-woven fabric is laminated as a cover member only of the non-woven fabric is considered to enhance the heat insulation and water retention ability and to prevent or suppress condensation of the pipe. However, even in a heat insulation cover member obtained by disposing a non-woven fabric on the surface of such a foam and performing embossing, in a portion where the length of the vertical pipe is severe, when crossing a beam or a vertical wall of an apartment or a building, condensed water may drip due to the influence of gravity. When the condensed water drips, molds and fungi are generated in that portion or in the vicinity of the dripping portion, and the surrounding environment becomes unhygienic. Therefore, the present invention provides a heat insulation cover member for preventing or suppressing dripping of condensed water capable of suppressing or preventing dripping of condensed water on the surface in the case of a refrigerant pipe such as a vertical pipe for an air conditioner or the like, or in a duct cover, a heat exchange pipe covering member and a duct covering member, a pipe structure and a duct covering structure using these. , and And a method of using the heat insulation cover member as a heat exchange pipe covering member are provided. Here, in the present invention, the heat exchange pipe covering member means pipe members such as a covering member for joints, an elbow covering member, and a covering member to be put on an existing conventional pipe cover. If necessary, a cheese covering member may be included.

Means for Solving the Problems

[0010] In view of the above object, the present invention provides a non-woven fabric in which superabsorbent resin fibers are mixed with at least thermoplastic resin fibers constituting a skeletal structure (preferably a non-woven fabric that satisfies a predetermined value for the water retention parameter defined in the present invention and the water retention amount in the water retention test) even in a harsh use environment where condensed water drips in practical piping. It has been found that when this non-woven fabric is laminated on the surface of a polyethylene-based resin foam and used, the dripping of condensed water is less likely to occur. Although the reason for this is not necessarily clear, it is presumed that by blending superabsorbent resin fibers into the non-woven fabric, not only the water retention property is enhanced, but also the diffusion and evaporation properties of water within the non-woven fabric are optimized, leading to the excellent effects as described above. The present invention has been made based on this new finding, A heat-insulating cover member for preventing or suppressing the dripping of condensed water, a heat cross-linking pipe covering member and a duct covering member, a piping structure and a duct covering structure using these , and and has also completed the method of using, as a covering member for joints, elbow covering members, and covering members to cover existing conventional piping covers, etc., of the heat cross-linking pipe covering member of the heat-insulating cover member. That is, the present invention comprises the following means.

[0011] The invention of a dew condensation drip prevention or drip suppression heat retaining cover member in which a single-layer nonwoven fabric obtained by mixing a superabsorbent resin at a predetermined mixing ratio on one surface of the resin foam described in the following (1) is fixed to the surface of the polyethylene-based resin foam by fusion or adhesion, and the inventions of (2) to (4) which are dependent claims of the invention of (1) are set as reference examples separately from the present invention. (1) A heat-insulating cover member for preventing or suppressing the dripping of condensed water, in which a non-woven fabric is disposed on the surface of a resin foam, wherein the resin foam is a polyethylene-based resin foam having closed cells, and the non-woven fabric is fixed to one surface of the resin foam by fusion or adhesion, the non-woven fabric is composed of a single-layer non-woven fabric in which a predetermined amount of superabsorbent resin fibers are mixed with thermoplastic resin fibers, and at least a part of the thermoplastic resin fibers are fused or adhered to each other, The non-woven fabric contains 10% by mass or more and 80% by mass or less of the superabsorbent resin fibers, and further contains 20% by mass or more and 90% by mass or less of the thermoplastic resin fibers as the balance. A heat-insulating cover member for preventing or suppressing the dripping of condensed water, in which the non-woven fabric is joined to the surface of the resin foam. Here, in (1), by the nonwoven fabric used in the invention containing 10% by mass or more and 80% by mass or less of superabsorbent resin fibers, it becomes possible to prevent or suppress the dripping of condensed water. Further, by the nonwoven fabric containing 20% by mass or more and 90% by mass or less of thermoplastic resin fibers, while diffusing and evaporating the moisture absorbed by the nonwoven fabric, the mechanical strength of the nonwoven fabric containing superabsorbent resin fibers and the fusion or adhesion strength with the resin foam can be ensured. (2) The fiber diameter of the thermoplastic resin fibers used for the nonwoven fabric is in the range of 5 to 30 μm, the product thickness of the nonwoven fabric is 0.5 to 2.0 mm, and the basis weight of the nonwoven fabric is 30 to 300 g / m 2 The heat-insulating cover member for preventing or suppressing the dripping of condensed water according to (1), characterized in that it is as described above. (3) With respect to the total mass of the nonwoven fabric, the thermoplastic resin fibers, which are the base resin fibers of the nonwoven fabric, are composed of single fibers of polyethylene terephthalate, polyethylene, or polypropylene, or core-sheath structure fibers thereof, or fibers in which other fibers are mixed with any of these fibers. The nonwoven fabric is such that at least a part of the thermoplastic resin fibers are fused or adhered to each other. The polyethylene-based resin foam contains a flame retardant. The heat-insulating cover member for preventing or suppressing the dripping of condensed water according to (1), characterized in that it is as described above. (4) A nonwoven fabric having a water retention parameter for retaining moisture against the gravity of the nonwoven fabric of 0.70 or more and satisfying a water retention amount of 7.0 g or more obtained under predetermined conditions. The retention parameter is obtained by providing a marking line that crosses in the width direction on the surface at the middle position in the longitudinal direction of a strip-shaped test piece with dimensions of length 200 mm × width 25 mm, dripping 400 μL of a test liquid colored at the marking line with the test piece in a horizontal state, and immediately after dripping, holding the test piece in the vertical direction for 5 minutes, and is a parameter obtained by dividing the average value in the width direction of the rising distance of the test liquid to the reaching point above the marking line of the test piece, which is an index value using the rising distance from the marking line of the test piece and the falling distance from the marking line of the test piece, by the average value in the width direction of the falling distance of the test liquid to the reaching point below the marking line of the test piece. Furthermore, the water retention amount is determined as follows: After inserting a refrigerant pipe with the heat insulation cover member attached to the outer periphery of a refrigerant pipe having a length of 150 mm and a diameter of 25 mm into a container with 20 g of water added and holding it, the container is further placed in a thermostatic and humidistatic chamber at 23°C and 30% for 6 hours, then the container is taken out, dehydrated, and the water retention amount is obtained from the mass after dehydration. The heat insulation cover member for preventing or suppressing the dripping of condensed water according to (1) is characterized in that

[0012] (1) A heat insulation cover member for preventing or suppressing the dripping of condensed water, in which a non-woven fabric is disposed on the surface of a resin foam, the resin foam is a polyethylene-based resin foam having closed cells, and the non-woven fabric is fixed to one surface of the resin foam by fusion or adhesion, the non-woven fabric is a laminated non-woven fabric having a laminated structure of a first layer and a second layer, the first layer of the non-woven fabric is composed only of thermoplastic resin fibers, at least a part of the thermoplastic resin fibers are fused or adhered to each other, and it is a transpiration diffusion promoting layer that promotes the transpiration effect due to the evaporation of moisture, the second layer of the non-woven fabric is composed of a non-woven fabric in which a predetermined amount of highly water-absorbent resin fibers that retain water in a gel structure crosslinked with a polymer is mixed with thermoplastic resin fibers, at least a part of the thermoplastic resin fibers are fused or adhered to each other, and it is a water retention layer having a higher water retention property than the first layer, the non-woven fabric of the second layer contains 10% by mass or more and 80% by mass or less of highly water-absorbent resin fibers with respect to the total mass of the non-woven fabric constituting the second layer, and further contains 20% by mass or more and 90% by mass or less of the thermoplastic resin fibers as the balance, the non-woven fabric having the first layer and the second layer has an evaporation amount of 8.88 g or more, the evaporation amount and is is a value obtained by subtracting the mass at the time of removal from the total mass before the start of the test, The total mass before the test refers to A refrigerant pipe with a length of 150 mm and a diameter of 25 mm covered with the heat insulation cover member on the outer periphery is placed in a container with 20 g of water added the total mass of the test piece thus formed, The mass at the time of removal refers to when the test piece After holding in a thermostatic and humidistatic chamber at 23°C and a relative humidity of 30% RH for 6 hours, refers to the total mass of the test piece when the test piece is removed. A heat-insulating cover member for preventing or suppressing dripping of condensed water from a pipe, characterized by the above. (2) The heat-insulating cover member for preventing or suppressing dripping of condensed water according to claim 1, wherein the polyethylene-based resin foam contains a flame retardant.

[0013] (3) A joint covering member that can be arranged to cover the gap between the heat-insulating cover members when the pipe is covered with the heat-insulating cover member for preventing or suppressing dripping of condensed water described in (1) or (2), wherein the joint covering member is an adhesive on one surface of the foam layer On which a release paper is laminated, and a non-woven fabric is coated on the other surface of the foam, and the joint covering member is used at the joint of the cover member by laminating the adhesive layer on the outer periphery of the heat-insulating cover member with the bonding surface of the non-woven fabric to the foam as the outer periphery, and it is possible to prevent or suppress dripping of condensed water. A joint covering member characterized by this. (4) By press-forming the heat-insulating cover member for preventing or suppressing dripping of condensed water described in (1) or (2) so that it can cover the 90° bent portion of the pipe, it is bent in a shape where two mutually back-to-back shapes of a predetermined size face each other and then becomes a substantially L-shaped shape. The heat-insulating cover member for preventing or suppressing dripping of condensed water is characterized in that it can prevent or suppress dripping of condensed water by covering the elbow portion of the 90° bent portion or the vicinity of the 90° bent portion where the pipe is directly bent by 90° with the bonding surface of the non-woven fabric to the foam of the member obtained as the outer surface. (5) By the heat-insulating cover member for preventing or suppressing dripping of condensed water described in (1) or (2), a cover member that covers an existing pipe with a polyethylene film laminated on its surface is wound around the heat exchanger pipe in a substantially cylindrical shape so that the center faces and both ends face each other, and further, the heat-insulating cover member is wound around the outer surface of the cover member that covers the existing conventional pipe cover so that the non-woven fabric surface is the outer surface and both ends face each other, and it is possible to prevent or suppress dripping of condensed water. A cover member for covering an existing conventional pipe cover, characterized by this. A duct covering member, characterized in that the outer surface of the duct can be covered by the dew condensation preventing or suppressing heat insulating cover member described in (6)(1) or (2). (7) In a piping structure including at least one of a horizontal pipe, an inclined pipe, a vertical pipe, and a bent pipe, in which the dew condensation preventing or suppressing heat insulating cover member described in (1) or (2) is covered around the refrigerant pipe, the dew condensation preventing or suppressing heat insulating cover member uses either the first layer or the second layer of the nonwoven fabric of the laminated structure as the outer surface, and each of the heat insulating cover members covers the refrigerant pipe. A piping structure characterized by this. (8) In a piping structure including at least one of a horizontal pipe, an inclined pipe, a vertical pipe, and a bent pipe, in which the dew condensation preventing or suppressing heat insulating cover member described in (1) or (2) is covered around each of two refrigerant pipes, and the heat insulating cover members are thermally fused or adhered to each other to form a glasses-type cross-sectional pipe, each of the refrigerant pipes of the piping structure uses either the first layer or the second layer of the nonwoven fabric of the laminated structure of the dew condensation preventing or suppressing heat insulating cover member as the outer surface, and each of the refrigerant pipes is covered. By opposing each of the refrigerant pipes to each other and thermally fusing or adhering the outer surfaces of the nonwoven fabric, the two pipes are integrated into a glasses type. A piping structure characterized by this. (9) One or more refrigerant pipes, drain pipes, wiring, and piping for wiring are provided, and one or more refrigerant pipes, drain pipes, wiring, and piping for wiring are housed inside the dew condensation prevention or dripping suppression heat insulation cover member described in (1) or (2). In a piping structure including at least one of horizontal pipes, diagonal pipes, vertical pipes, and bent pipes, using either the surface of the first layer or the second layer of the non-woven fabric of the laminated structure as the outer surface, the outer peripheral surface shape of the dew condensation prevention or dripping suppression heat insulation cover member is substantially cylindrical in cross-section. The refrigerant pipes, drain pipes, wiring, and piping for wiring are surrounded by the heat insulation cover member so that they can be housed inside the dew condensation prevention or dripping suppression heat insulation cover member, and the components installed in the pipes are housed inside the dew condensation prevention or dripping suppression heat insulation cover member. A piping structure for refrigerant pipes, characterized by this. (10) The dew condensation prevention or dripping suppression heat insulation cover member described in (1) or (2) is covered on the entire outer surface of an iron duct for a heat exchanger having a substantially rectangular cross-section so as to cover the outer periphery of the entire outer surface. A covering structure for preventing or suppressing dew condensation dripping of a heat exchanger duct using a heat insulation cover member.

[0015] ( 11 )(1) or (2) The dew condensation prevention or dripping suppression heat insulation cover member described above is used as a joint covering member used in the gap between heat insulation cover members, an elbow covering member, a cheese covering member, or a covering member for covering an existing conventional pipe cover. A method of using a dew condensation prevention or dripping suppression heat insulation cover member for a heat exchange pipe covering member.

Effects of the Invention

[0016] In the present invention of the laminated nonwoven fabric having a laminated structure composed of the first layer and the second layer of nonwoven fabric A heat-insulating cover member for preventing or suppressing the dripping of condensed water, a covering member for joints, an elbow covering member, a covering member for covering an existing conventional pipe cover, and a duct covering member, a pipe structure and a covering structure using the same, a method of using the heat-insulating cover member, and a method of using the heat-insulating cover member for heat exchange pipe parts (covering member for joints, elbow covering member, covering member for covering an existing conventional pipe cover). According to this, it is possible to suppress or prevent the dripping of condensed water even in the case of refrigerant pipes such as those of air conditioners, which are pipes where condensed water is likely to drip like vertical pipes, or metal ducts (iron ducts). Note that the effect of the present invention is realized by optimizing both the water reduction effect due to the evaporation of condensed water generated by diffusing and evaporating the water absorbed by the non-woven fabric against the influence of gravity, and the water retention effect by the superabsorbent resin fibers mixed in the skeletal structure fibers.

Brief Description of the Drawings

[0017]

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Figure 15

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments for carrying out the present invention will be described in detail. FIG. 1 is a partially cutaway perspective view (a) and a cross-sectional view taken along the line X-X (b) schematically showing a piping structure 10 including a heat-insulating cover member 5 for preventing or suppressing dripping of condensed water according to a preferred embodiment of the present invention. The heat-insulating cover member 5 for preventing or suppressing dripping according to the present embodiment has a structure in which a non-woven fabric 3 is disposed on the surface of a resin foam 2 that covers a refrigerant pipe 1 enclosing a cavity (flow path) 6, and suppresses or prevents dripping of condensed water that has condensed on the surface of the non-woven fabric. This resin foam 2 is a polyethylene-based resin foam having closed cells. The non-woven fabric 3 is fixed to one surface of the resin foam 1 by fusion or adhesion. Hereinafter, in the present invention, both the terms "diffusive evaporation" and "diffusive transpiration" are used, but both are to be construed as substantially synonymous in the present invention.

[0019] [Various parameters] In this embodiment state of the heat-insulating cover member 5 for preventing or suppressing dripping, the non-woven fabric 3 contains 10% by mass or more and 80% by mass or less of superabsorbent resin fibers, preferably 15% by mass or more and 75% by mass or less, and more preferably 25% by mass or more and 75% by mass or less. If the content of the superabsorbent resin fibers is less than the above lower limit value, the prevention or suppression of dripping of condensed water will be poor. If the content of the superabsorbent resin fibers exceeds the above upper limit value, the bonding property and shape stability of the non-woven fabric will be poor. When the non-woven fabric is composed of a plurality of layers, in the layer containing the superabsorbent resin fibers, the blending amount (mixing ratio) is within the above range.

[0020] The average fiber diameter of the base fibers of the non-woven fabric used in the present invention is preferably in the range of 5 to 30 μm, and usually fibers in this range are often used for non-woven fabrics. The reason for this is that if the fiber diameter is less than the above lower limit value, the strength of the non-woven fabric is insufficient, so the durability during use on the surface of the protective member tends to decrease. because of 。Also, when the fiber diameter exceeds the upper limit value, due to the increase in the diameter of the non-woven fabric, the entanglement of the base resin and the stability of the fusion structure tend to be lost. Therefore, the average fiber diameter is preferably in the range of 10 to 25 μm or 12 to 23 μm. More preferably, it is 15 to 20 μm. In each test material of each example described later, the measured value of the fiber diameter of each test material was described as the fiber diameter for the sake of simplicity, but these measured values of the fiber diameter mean the average fiber diameter. Note that the fiber diameter of the base fiber (thermoplastic resin fiber) of the non-woven fabric defined here (fiber diameter excluding the superabsorbent resin fiber described later) is the same for the fiber diameters of the first layer and the second layer when the non-woven fabric is a two-layer non-woven fabric, and the preferable range also means the average fiber diameter in the same way. Further, in the superabsorbent resin fiber used in the present invention, the fiber diameter of the superabsorbent resin fiber may be larger than that of the thermoplastic resin fiber, but if the fiber diameter of the superabsorbent resin fiber becomes too large, the expansion amount of the superabsorbent resin fiber becomes too large, and the non-woven fabric structure of the base resin becomes unstable, and there is a problem that the water absorption points in the non-woven fabric are biased. Therefore, the maximum value of the diameter of the superabsorbent resin fiber is 100 μm or less, and the heat ratio of the diameter of the superabsorbent resin fiber to the thermoplastic resin fiber is desirably within 4 times, and further, the maximum value of the diameter of the superabsorbent resin fiber is 80 μm or less, and the heat ratio of the diameter of the superabsorbent resin fiber to the thermoplastic resin fiber is more desirably within 3 times.

[0021] In the heat-insulating cover member 5 for preventing or suppressing the dripping of condensed water in the present embodiment, the product thickness of the non-woven fabric 3 is preferably 0.5 to 2.0 mm, more preferably 0.6 to 1.6 mm, and even more preferably 0.7 to 1.4 mm. Note that when the non-woven fabric 3 is a laminate of two or more layers, it is preferable that the total thickness is within the above range. If the non-woven fabric thickness is less than the above lower limit value, the base resin fiber cannot stably hold the superabsorbent resin fiber. On the other hand, if the product thickness exceeds the above upper limit value, the shape stability of the non-woven fabric after water absorption decreases. When the nonwoven fabric is composed of two layers, the product thickness of the nonwoven fabric 3 is preferably such that the total of the two layers is within the above range. When the two layers are distinguished and shown, the first layer (the layer not containing superabsorbent resin fibers) is preferably 0.05 to 0.6 mm, more preferably 0.1 to 0.5 mm, and even more preferably 0.2 to 0.4 mm. The product thickness of the second layer (the layer containing superabsorbent resin fibers) is preferably 0.3 to 1.5 mm, more preferably 0.4 to 1.2 mm, and even more preferably 0.5 to 1.0 mm. Relatively, it is preferable that the thickness of the first layer is smaller than the thickness of the second layer.

[0022] The basis weight of the nonwoven fabric 3 is preferably 30 g / m 2 or more, more preferably 35 g / m 2 or more, and even more preferably 40 g / m 2 or more. As the upper limit value, it is preferably 300 g / m 2 or less, more preferably 250 g / m 2 or less, and even more preferably 200 g / m 2 or less, and even more preferably 150 g / m 2 or less. When the nonwoven fabric 3 is composed of two layers, when each of the two layers is defined, the basis weight of the second layer (the layer containing superabsorbent resin fibers) is 10 to 250 g / m 2 and preferably 15 to 200 g / m 2 and more preferably 15 to 150 g / m 2 and even more preferably 20 to 150 g / m 2 The basis weight of the first layer (the layer not containing superabsorbent resin fibers) is 5 to 50 g / m 2 and preferably 10 to 30 g / m 2 and more preferably 15 to 25 g / m 2 and even more preferably. In addition, when the nonwoven fabric 3 is a laminate of two or more layers, it is preferable that the total basis weight is within the above range. In the present invention, if the basis weight of the nonwoven fabric is less than the above lower limit, sufficient water retention cannot be ensured. On the other hand, if the basis weight exceeds the above upper limit, it will affect the fusibility after water absorption of the fused part, the shape of the nonwoven fabric after water absorption will become unstable, and the molding processability will further deteriorate. Also, the upper and lower limits of the second layer containing superabsorbent resin fibers when the nonwoven fabric is formed of two layers are for the same reason. Here, since the first layer is a layer that promotes the transpiration effect by the diffusion and evaporation of the absorbed water, the basis weight does not need to be as large as that of the second layer, and it is desirable that the basis weight of the first layer is smaller than that of the second layer, and it is sufficient if it is within the above range. Also, regarding the basis weight of the single-layer product and the laminate, in the case of the lance seal, the basis weight was deliberately increased to know the characteristics of the nonwoven fabric of the laminate when the basis weight of the second layer is large, but in other cases like as understood, in the case of the laminate, it is possible to reduce the total basis weight. In the case of the nonwoven fabric of the single-layer product, since the mixing ratio of the superabsorbent resin fibers in the nonwoven fabric is 10% to 80%, the mixing ratio of the base resin is 20% to 90%. Therefore, when the basis weight of the nonwoven fabric is 300 g / m 2 then the basis weight of the base resin fibers is 60 to 270 g / m 2 when the basis weight of the nonwoven fabric is 200 g / m 2 then the basis weight of the base resin fibers is 40 to 180 g / m 2 when the basis weight of the nonwoven fabric is 150 g / m 2 then the basis weight of the base resin fibers is 30 to 135 g / m 2 when the basis weight of the nonwoven fabric is 50 g / m 2 then the basis weight of the base resin fibers is 10 to 45 g / m 2 and it is possible to be in the range.

[0023] The fiber diameter of the superabsorbent resin fibers mixed in the nonwoven fabric 3 is not particularly limited, but it is preferably larger than the fiber diameter of the thermoplastic resin fibers constituting the nonwoven fabric. Specifically, the fiber diameter of the superabsorbent resin fibers is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 30 μm or more. As the upper limit value, 100 μm or less is preferable, 80 μm or less is more preferable, and 50 μm or less is even more preferable.

[0024] In the heat-insulating cover member 5 for preventing or suppressing the dripping of condensed water according to the present embodiment, the water retention parameter for retaining moisture against the gravity of the nonwoven fabric 3 is preferably 0.70 or more, more preferably 0.80 or more, and even more preferably 1.00 or more. Although no upper limit is particularly provided, due to the nature of the parameter for retaining moisture against gravity, it is virtually impossible to exceed 1.3, and it is considered that the maximum is 1.3 or less. By the water retention parameter being equal to or greater than the above lower limit value, an effect of improving the diffusion function and the transpiration function can be expected.

[0025] In the heat-insulating cover member 5 for preventing or suppressing the dripping of condensed water according to the present embodiment, the water retention amount in the water retention test of the nonwoven fabric 3 is preferably 7.0 g or more, more preferably 7.5 g or more, even more preferably 8.0 g or more, even more preferably 8.5 g or more, and even more preferably 9.0 g or more. The upper limit is likely to be 20 g or less even considering water absorption from the test environment atmosphere in addition to the amount of water injected. By the water retention amount being equal to or greater than the above lower limit value, the water retention function is improved, and as a result, an effect of preventing or suppressing the dripping of condensed water can be expected. Here, since the nonwoven fabric of the present invention expects a synergistic effect of both the water retention parameter and the water retention property, it is necessary to satisfy at least both the water retention parameter being 0.70 or more and the water retention amount in the evaporation environment being 7.0 g or more, and it is particularly preferable to satisfy both.

[0026] FIG. 2 is a partially cutaway perspective view (a) and a cross-sectional view taken along the line Y-Y (b) schematically showing a pipe structure 20 including a heat-insulating cover member 5 for preventing or suppressing dripping of condensed water according to another preferred embodiment of the present invention. The pipe structure 20 of the present embodiment has a glasses-type pipe structure in cross section in which two pipes (a refrigerant pipe 1 containing a cavity (flow path) 6) are connected (see FIG. 2(b)). The pipes may be connected by heat-sealing the nonwoven fabric 3 as shown in the drawing, or the resin foam 2 may be heat-fused in part to to form a stronger connection structure. Also in the present embodiment, each parameter such as the amount or fiber diameter of the thermoplastic resin fibers constituting the nonwoven fabric 3 and the superabsorbent resin fibers mixed therein is synonymous with the values defined in the embodiment according to FIG. 1, and the preferred ranges are also the same.

[0027] FIG. 3 is a cross-sectional view schematically showing a pipe structure 30 including a heat-insulating cover member 5 for preventing or suppressing dripping of condensed water according to still another preferred embodiment of the present invention. In the present embodiment, the nonwoven fabric 3 constituting the heat-insulating cover member 5 for preventing or suppressing dripping of condensed water has a two-layer structure of a first layer 31 and a second layer 32. Also in the present embodiment, each parameter such as the amount or fiber diameter of the superabsorbent resin fibers mixed in the nonwoven fabric 3 is synonymous with the values defined in the embodiment according to FIG. 1, and the preferred ranges are also the same. The preferred ranges of the first layer and the second layer regarding the thickness and basis weight of the nonwoven fabric are as already described in the section of [various parameters] above.

[0028] FIG. 4 is an enlarged cross-sectional view schematically showing the When using the single-layer nonwoven fabric of the reference example internal structure of the heat-insulating cover member 5 for preventing or suppressing dripping of condensed water of the embodiment shown in FIG. 1. This figure only schematically shows a microscopic structure, and the actual product in the present invention does not have to exactly match what is shown in the figure. In the present embodiment, as shown in the figure, thermoplastic resin fibers 35 constituting the nonwoven fabric 3 and superabsorbent resin fibers 36 mixed therein are applied. The thermoplastic resin fibers 35 may have a fiber structure in which they are intertwined with each other and fused or adhered in part.

[0029] Fig. 5A(a) is an enlarged cross-sectional view schematically showing the internal structure of the heat-insulating cover member 5 for preventing or suppressing dripping in the embodiment shown in Fig. 3. In this embodiment, any adhesion structure may be adopted between the first layer 31 and the second layer 32, and the thermoplastic resin fibers 35 may be intertwined with each other, or a part of them may be heat-fused or adhered. In the embodiment of Fig. 5(a), an example is shown in which the highly water-absorbent resin fibers 36 are mixed in the second layer 32 and arranged in the lower layer. The embodiment of Fig. 5B(b) is an example in which the non-woven fabric of Fig. 5A(a) is turned upside down in the upper and lower layers. That is, in Fig. 5B(b), the highly water-absorbent resin fibers 36 are mixed in the second layer 32 and arranged in the upper layer. In the present invention, although not particularly limited, a form in which highly water-absorbent resin fibers are not blended in the outer layer (first layer) 31 and the inner layer (second layer) contains highly water-absorbent resin fibers (Fig. 5A(a)) is preferable.

[0030] [Resin foam] In the present invention, the resin foam 2 includes independent air bubbles 21 (Figs. 4 and 5). In the present invention, the resin foam 2 is a polyethylene-based resin foam. That is, as the resin used for the resin foam 2, polyethylene resins such as low-density polyethylene (LDPE) and high-density polyethylene (HDPE) can be used alone, or a mixed resin of low-density polyethylene and high-density polyethylene can be used. Further, heat resistance and flame retardancy can be imparted to these polyethylene-based resin foams as necessary. When using a mixed resin of low-density polyethylene and high-density polyethylene, a mixed resin in which low-density polyethylene and high-density polyethylene are mixed at a predetermined mixing ratio, for example, 60 parts by mass of high-density polyethylene with respect to 40 parts by mass of low-density polyethylene, can be used. As the polyethylene-based resin, in addition to low-density polyethylene and high-density polyethylene, polyethylene-based modified resins such as ethylene-vinyl acetate copolymer polyethylene (EVA) can be used. The reason for using ethylene-vinyl acetate copolymer polyethylene instead of polyethylene is that it has high flexibility and elasticity, so it can be used for various product applications. For example, for low-density polyethylene, F120N manufactured by Ube Maruzen Polyethylene Co., Ltd. can be used; for high-density polyethylene, HD1300 manufactured by Nippon Polyethylene Co., Ltd. can be used, etc.; for vinyl acetate copolymer polyethylene, DQDJ-1868 manufactured by ENEOS NUC Co., Ltd. can be used.

[0031] In addition, in order to improve the flame retardancy of the foam, when making it flame retardant, a flame retardant is added. However, for 100 parts by mass of the resin, a predetermined amount of an antimony-based flame retardant such as antimony trioxide, magnesium hydroxide, aluminum hydroxide, a hydroxide-based flame retardant, or a bromine-based flame retardant can be added. In addition to the above-mentioned antimony-based flame retardant, bromine-based flame retardant, and hydroxide-based flame retardant, an inorganic filler may be added. Also, when imparting heat resistance, carbon and titanium oxide may be further added within a predetermined range. In addition to the above, a predetermined amount of an inorganic filler, antioxidant, and stabilizer can be added as needed.

[0032] For example, when adding a flame retardant, if the addition amount of the flame retardant exceeds 100 parts by mass, the effect will saturate and at the same time the foamability will be inhibited. Therefore, the total is 100 parts by mass or less. If the addition amount of the flame retardant exceeds 100 parts by mass, the foamability will be inhibited by the flame retardant. Therefore, the upper limit needs to be 100 parts by mass or less. Here, the preferable addition amounts of the antimony-based flame retardant and the bromine-based flame retardant are each 20 parts by mass or less, and the preferable addition amount of the hydroxide-based flame retardant is 80 parts by mass or less. Note that since the specific gravity of any flame retardant is larger than that of the resin component, when converted to the volume ratio for mixing, the mixing ratio with respect to the resin component is significantly smaller than the mass ratio. Therefore, within the above addition amount range, there is no particular problem.

[0033] Here, the method for manufacturing a polyethylene-based resin foam will be described in the case of using low-density polyethylene as the base resin. First, an organic decomposable foaming agent and a crosslinking agent are blended with low-density polyethylene as the base resin, kneaded in a pressure kneader, and pelletized to obtain pellets of a foaming resin composition. The pellets thus obtained are introduced from the hopper of a short-axis extruder and extruded through a die of a predetermined width to obtain a foaming base material sheet of a predetermined thickness.

[0034] Following the heat extrusion of the foaming base material sheet, the resin foam is continuously heated in a heating furnace and foamed to a predetermined magnification, and then passed through rolls to adjust the dimensions and surface properties of the foam, and then cut to a predetermined width according to the diameter of the pipe to be wound.

[0035] The foaming magnification needs to be controlled in consideration of heat insulation properties and cushioning properties. Also, when performing embossing, if the foaming magnification is too high, it becomes difficult to stably and uniformly perform the embossing after laminating the non-woven fabric. If the foaming magnification is too low, the rigidity of the resin is too strong, and the desired embossing height cannot be obtained, and there is a problem of reduced heat insulation properties. Therefore, the foaming magnification of the resin foam is preferably 20 to 40 times, and there are no particular problems within this range. Regarding the cushioning property, there are no particular problems as long as the foaming magnification is in the range of 20 to 40 times. Also, the thickness of the resin foam can be 15 mm or 20 mm, but usually 10 mm is often used. The reason for this is that considering the decrease in moldability such as the bendability of the heat exchange pipe after attaching the cover member when the thickness of the resin foam increases, and the decrease in workability during pipe work due to the increase in the product cross-sectional area, a resin foam with a thickness of 10 mm is often used as the cover member.

[0036] In this embodiment, the non-woven fabric is fixed to one surface of the resin foam by fusion or adhesion, and the other surface of the resin foam is wound around a refrigerant pipe and used. It is preferable that the resin foam and the refrigerant pipe are in contact with each other, but other members may be interposed therebetween. By joining a non-woven fabric to at least one surface of a polyethylene-based resin foam by fusion or adhesion, a heat insulating material for preventing or suppressing the dripping of condensed water according to the present invention can be obtained.

[0037] [Non-woven fabric and its base material fibers (thermoplastic resin fibers)] In the present invention, as the fibers of the non-woven fabric, a mixture of a predetermined amount of superabsorbent resin fibers and thermoplastic resin fibers serving as base material fibers is used. However, a non-woven fabric composed only of thermoplastic resin fibers and a non-woven fabric composed of fibers in which superabsorbent resin fibers are mixed with thermoplastic resin fibers at a predetermined mixing ratio may be used in combination. First, the thermoplastic resin fibers constituting the base material fibers will be described.

[0038] The thermoplastic resin fibers are for the purpose of a diffusion and transpiration function when used in a non-woven fabric composed only of base material fibers. Therefore, a water absorption function is not necessary. On the other hand, when used in a non-woven fabric composed of fibers in which superabsorbent resin fibers are mixed with base material fibers at a predetermined mixing ratio, since they are also used to form the skeleton of these non-woven fabrics and hold the superabsorbent resin fibers, it is expected to impart shape stability and a predetermined strength to the non-woven fabric and to diffuse and evaporate the moisture adsorbed on the surface of the non-woven fabric by surface tension. Therefore, it is not necessary for the base material fibers themselves to have water absorption. In the present invention, the non-woven fabric is one in which at least a part of the thermoplastic resin fibers are fused or adhered to each other.

[0039] When these thermoplastic resin fibers are used by mixing with highly water-absorbent resin fibers, they form the skeletal structure of the nonwoven fabric. The role of the nonwoven fabric composed only of thermoplastic resin fibers is to act as the water diffusibility and the water retention force under gravity as the thermoplastic resin fibers forming the skeletal structure are estimated from the results of the holding force parameter test described later, and it can improve the water absorption diffusibility by capillary action. However, for promoting the evaporation of moisture, it is better that the water retention property of the nonwoven fabric is not too high. It is preferable that the moisture is retained not by chemically bonding the moisture in the nonwoven fabric or incorporating it into the gel like the highly water-absorbent resin fibers, but by surface tension. Further, when the thermoplastic resin fiber layer is arranged behind the highly water-absorbent resin fiber layer, the surface of the thermoplastic resin fiber layer will be covered by the highly water-absorbent resin fiber layer. because It is desirable to use the thermoplastic resin fiber layer as the outer surface. From such a viewpoint, chemical material-based synthetic fibers can be used as the fibers constituting the nonwoven fabric. As the chemical material-based synthetic fibers, thermoplastic resin fibers are used, and polyester-based fibers, polyethylene fibers, polypropylene fibers, acrylic fibers, etc. can be used. More specifically, single fibers of polypropylene (PP), polyethylene (PE), or polyethylene terephthalate (PET), or fibers having a core-sheath structure of these (specifically, fibers having a core-sheath structure of polyethylene terephthalate / polyethylene, polyethylene terephthalate / polypropylene, polypropylene / polyethylene), or fibers obtained by mixing other fibers with any of these fibers, etc. can be mentioned. Examples include nonwoven fabrics in which at least a part of these thermoplastic resin fibers are fused or adhered to each other. Note that examples of the other fibers include acrylic resins.

[0040] Acrylic fiber is a fiber composed of a linear synthetic polymer containing 85% or more by mass of repeating units of acrylonitrile groups. Although acrylic fibers slightly decrease in strength due to moisture absorption, the dry-wet strength ratio is 0.9 or more, and the strength decrease is slight compared to rayon and vinylon, which are natural material-based fibers. Therefore, when acrylic fibers are used as mixed fibers with other non-water-absorbent fibers, there are no particular problems.

[0041] As the thermoplastic resin fiber, in addition to using a mixture of two types of fibers, a nonwoven fabric using a fiber having a core-sheath structure can be used. The merit of using such a fiber having a core-sheath structure for the nonwoven fabric is that when the fibers are fused to each other, for example, polyethylene terephthalate fiber or polypropylene fiber is used for the core part, sheath and polyethylene fiber is used for the sheath part, thereby enabling mutual fusion of the fibers at a relatively low temperature of 120 to 140 °C, making it possible to facilitate the production of the nonwoven fabric. At the same time, by using a higher-strength fiber for the core part than for the sheath sheath part, the rigidity of the fiber used for the nonwoven fabric can be increased, and thereby the fiber diameter of the fiber constituting the nonwoven fabric can be made smaller accordingly.

[0042] As the thermoplastic resin fiber, a plurality of fibers having different melting points are used, and the fiber having a lower melting point is melted and used as a binder to constitute the nonwoven fabric. Here, when PET fiber and polyethylene fiber are mixed and used at a predetermined ratio, the polyethylene fiber acts as a binder. For example, when PET resin is used as the main constituent fiber, for the low-melting-point fiber as a binder, a copolyester (Co-PET) resin, a polypropylene resin, a polyethylene resin, etc. can be used. By adopting the above structure, it becomes easier to control the strength etc. of the nonwoven fabric.

[0043] Here, as the thermoplastic resin fiber, a nonwoven fabric using a fiber obtained by combining a fiber having a core-sheath structure with different melting points and other fibers can also be used. For example, by using a higher-strength fiber for the core part than for the sheath part to increase the rigidity of the fiber used for the nonwoven fabric, and at the same time using a higher-strength fiber, a hollow fiber, etc. for the other fiber and controlling the mixing ratio of the two, it becomes possible to improve the mechanical properties of the nonwoven fabric or impart flexibility to the nonwoven fabric.

[0044] Further, when long fibers are used as the thermoplastic resin fiber, the fibers tend to be oriented in the MD direction which is the main direction during the production of the nonwoven fabric, and due to this influence MD The mechanical properties in the direction tend to have higher rigidity compared to the mechanical properties in the TD direction. Therefore, when used as a base fiber that forms a skeleton by mixing with superabsorbent resin fibers, the skeleton structure is stabilized. For this reason, it is desirable to use long fibers. In addition to long fibers, a predetermined amount of short fibers can be added and used as mixed fibers. By using some short fibers in this way, it becomes possible to mitigate the influence of the orientation of the fibers in the MD direction and improve the orientation in the TD direction, and an anisotropy improvement effect can be expected.

[0045] [Method for manufacturing a nonwoven fabric using thermoplastic resin fibers] Next, the method for manufacturing a nonwoven fabric using thermoplastic resin fibers will be confirmed. A normal nonwoven fabric is formed by forming a film-like sheet called a web composed only of fibers, and by bonding each fiber forming the formed web to only the necessary parts with each other as needed.

[0046] There are various methods for forming a nonwoven fabric composed of thermoplastic resin fibers. For example, as methods for forming a web, there are both a wet method and a dry method. The wet method is a method of making a nonwoven fabric in the same way as the papermaking process. The method for forming a web in the dry method has various methods as will be described later, and any method can be used to form the web. However, for the use of preventing or suppressing the dripping of condensed water in the present invention, when using long fibers, since it is necessary to bend the fibers to form a three-dimensional structure of the nonwoven fabric, it is desirable that the fibers of the nonwoven fabric have a crimpability that allows the fibers to bend.

[0047] In addition, to obtain a nonwoven fabric from a web of thermoplastic resin fibers, it is necessary to bond the fibers forming the web at predetermined positions. Here, as methods for bonding the fibers of the web, there are various methods such as chemical bond methods like the dipping method and the spraying method, the thermal bond method, the spunbond method, the meltblown method, the meltplane method, the airlaid method, the spunlace method (water jet method), and the needle punch method. Here, as methods for forming a nonwoven fabric using long fibers, methods such as the following chemical bond method, thermal bond method, spunbond method, meltblown method, and meltplane method are used. As methods for forming a nonwoven fabric using short fibers, the chemical bond method, the thermal bond method, the airlaid method, and the needle punch method can be used. Note that the chemical bond method, the thermal bond method, the airlaid method, etc. can be used for both long fiber and short fiber methods.

[0048] Specifically, explaining each method, the chemical bond method is a method of partially bonding the web with an adhesive. The thermal bond method is a method of mixing low melting point heat-fusible fibers and passing them between hot rolls for thermocompression bonding, or applying hot air to melt the fibers and bond the heated parts of the fibers to bond the fibers together. The spunbond method is a method of directly connecting spinning and arranging the fibers and forming a fabric with self-fusing heat. The meltblown method is a method of directly connecting spinning and arranging the fibers and entangling ultrafine fibers. The meltplane method is a method of melting the resin and thinning the fibers with high-temperature air ejected from around the spinning nozzles and accumulating them in a sheet shape.

[0049] The air-laying method is a method of bonding pulp with air and a binder to form a nonwoven fabric. The spunlace method is a method of entangling fibers with a high-pressure water stream. The needle punching method is a method of manufacturing a nonwoven fabric by repeatedly piercing a web with special needles (needles) that move up and down at high speed, and entangling the fibers with the protrusions formed on the needles. When laminating nonwoven fabrics, the laminating method is not particularly limited. However, for laminating the first layer and the second layer, since the second layer contains superabsorbent resin fibers at a predetermined ratio, wet methods such as the spunlace method are not preferable, and it is preferably laminated by any one of the thermal bonding method, the chemical bonding method, or the needle punching method. However, in the present invention, the method for manufacturing the nonwoven fabric or its laminate is not limited. Also, for mixing different fibers, a carding machine is usually used, but any other known method can be applied as long as it is a method other than the wet method.

[0050] [Superabsorbent resin fiber] Superabsorbent resins have high water absorption, water absorption and have the effect of retaining the absorbed moisture in the gel structure in which the polymer is crosslinked, and at the same time have an equilibrium moisture absorption rate. Therefore, they have the property of absorbing moisture under high humidity conditions and releasing moisture under low humidity conditions. Examples of superabsorbent resin fibers include crosslinked acrylate-based fibers, fibers obtained by hydrolyzing the surface of acrylic fibers by post-processing, and fibers obtained by graft polymerizing acrylic acid or methacrylic acid onto fibers such as polyester. Among these, crosslinked acrylate-based fibers are particularly suitable because of their high water absorption.

[0051] The water absorption action of superabsorbent polymers will be described by taking the examples of polyvinyl alcohol and polyacrylic acid. In the case of polyvinyl alcohol / polyacrylic acid-based superabsorbent polymers, it has a structure in which islands of sodium polyacrylate exist in the sea of polyvinyl alcohol, and the crystallized polyvinyl alcohol acts as a crosslinking point for sodium polyacrylate. This water-absorbing polymer consists of two sets of layers, a part rich in the polyvinyl alcohol component and the polyacrylic acid part, and has a microphase separation structure in which the former contains the latter. In addition, although the polyvinyl alcohol phase exhibits some degree of water swelling, the water absorption capacity is mainly due to the polyacrylate phase. When the vinyl alcohol phase swells by several hundred times that of the polyacrylate phase, it is stretched and undergoes so-called crystallization under orientation. Here, the strength of the crystallized polyvinyl alcohol is very high and belongs to the category of tough polymers. Therefore, it is considered that the polyvinyl alcohol / polyacrylate superabsorbent polymer exhibits a composite structure in which the crystallized polyvinyl alcohol portion supports the polyacrylate portion in a highly water-absorbed state, and a gel that exhibits rigidity even in the water-absorbed state can be obtained.

[0052] Here, the "water-absorbent fiber" to be compared with the superabsorbent resin fiber will be described. As water-absorbent fibers, cellulose fibers, pulp, rayon fibers, etc. have water absorption, but compared with nonwoven fabrics using superabsorbent resin fibers, they do not have water absorption such that the water supply amount exceeds the self-weight of the fibers. Therefore, both the water absorption and water retention properties are inferior compared to nonwoven fabrics using superabsorbent resin fibers. Conversely, the superabsorbent resin fiber can be defined as a fiber or an aggregate thereof that exhibits water absorption exceeding its self-weight, preferably absorbs more than twice its self-weight, more preferably absorbs more than five times its self-weight, and even more preferably absorbs more than ten times its self-weight.

[0053] The superabsorbent resin fiber is composed of a resin having excellent water absorption and the property of swelling upon water absorption. Fibers containing a polymer having a hydrophilic group are preferably used. Representative examples of fibers containing a polymer having a hydrophilic group include crosslinked acrylic fibers. Such crosslinked acrylate fibers are obtained by subjecting a polymer obtained by reacting an acrylic acid monomer with a monomer having a functional group capable of forming a crosslinking bond therewith to a crosslinking treatment. These monomers may be used alone or in combination of multiple types, but it is preferable to set the functional group to an equivalent or less with respect to acrylic acid for the acrylic acid monomer and the functional group monomer. When reacting these, in order to impart plasticity, other vinyl monomers such as vinyl acetate (VA), acrylonitrile, etc. can be blended.

[0054] Typical commercially available products of such crosslinked acrylic fibers include "Vel Oasis" (registered trademark) manufactured by Teijin Fibers, Ltd., "Lanseal" (registered trademark) manufactured by Toyobo Co., Ltd., and the like. For example, in the case of the above-mentioned "Vel Oasis" (registered trademark), it exhibits excellent water absorption performance capable of absorbing water up to 80 times its own weight. Here, in the case of short fiber nonwoven fabrics, the web is mainly formed by the airlaid method or the carding method, and thermal bonding method or chemical bonding method is used for bonding the fibers forming the web. In some cases, needle punching method can be used for manufacturing.

[0055] [Method for bonding nonwoven fabric to polyethylene-based resin foam of nonwoven fabric] The bonding method between the nonwoven fabric and the resin foam is not particularly limited. For example, by placing the nonwoven fabric on one surface of the resin foam and performing hot roll forming, the nonwoven fabric and the polyethylene-based resin foam can be fused or adhered. At this time, it may be thermally fused in a form where an emboss is formed on the surface. Alternatively, an adhesive is applied to one surface of the polyethylene-based resin foam, and in this state, hot roll forming is performed with the nonwoven fabric placed on the surface of the polyethylene-based resin foam, so that the nonwoven fabric can be fixed to the surface of the polyethylene-based resin foam.

[0056] [Pipe structure] The dew condensation prevention or dripping suppression heat insulation cover member 5 according to the preferred embodiment of the present invention described above forms a pipe structure including at least a horizontal pipe, an inclined pipe, a vertical pipe, and a bent pipe, which are covered on the outer periphery of the refrigerant pipe 1 (see FIGS. 1 to 3). At this time, with the surface of the single-layer non-woven fabric or the surface of the first layer or the second layer of the laminated non-woven fabric of the dew condensation prevention or dripping suppression heat insulation cover member as the outer surface, each heat insulation cover member covers the refrigerant pipe (see FIGS. 1 and 3). Alternatively, the dew condensation prevention or dripping suppression heat insulation cover member 5 is covered on the outer periphery of each of the two refrigerant pipes 1, and an example is a spectacle-shaped cross-section pipe 20 in which the heat insulation cover members 5 are heat-sealed or adhered to each other (FIG. 2). At this time, in a pipe structure including any one of a horizontal pipe, an inclined pipe, a vertical pipe, and a bent pipe, with the surface of the single-layer non-woven fabric or the surface of the first layer or the second layer of the laminated non-woven fabric of the dew condensation prevention or dripping suppression heat insulation cover member as the outer surface on the outer periphery of each refrigerant pipe of the pipe structure, each refrigerant pipe is covered, and the outer surfaces of the non-woven fabrics are heat-sealed or adhered with the respective refrigerant pipes facing each other, so that the two pipes are integrated into a spectacle shape. Further, there is an aspect in which the non-woven fabric has a laminated structure, and the heat insulation cover member 5 is disposed on the resin foam 2 with the surface of either the second layer (the layer containing superabsorbent resin fibers) 32 or the first layer (the layer not containing superabsorbent resin fibers) 31 as the outer surface, forming a pipe structure 30 in which the refrigerant pipe 1 is covered (FIGS. 3, 5A, 5B). In the dew condensation dripping confirmation test using the vertical vertical pipe described later, the vertical pipe is most easily affected by gravity compared to the horizontal pipe, the inclined pipe, the bent pipe, etc. Further, in terms of the pipe structure, dew condensation water is retained in the concave portion near the connection portion of the spectacle-shaped pipe rather than the single pipe, and the retained dew condensation water becomes water droplets and drips easily , since the test conditions become more severe, in the dew condensation dripping confirmation test, the test was conducted by piping the spectacle-shaped pipe to the vertical pipe.

[0057] FIG. 6 is a cross-sectional view schematically showing a piping structure 40 (collective piping) according to still another preferred embodiment of the present invention. In the present embodiment, a refrigerant pipe 1 provided with two resin foams 2, a drain pipe 12, and a wiring pipe 13 are housed inside a heat retaining cover material 5 for preventing or suppressing dripping of condensed water of the present invention. At this time, it is preferable that the piping structure includes at least one of a horizontal pipe, an inclined pipe, a vertical pipe, and a bent pipe in which one or a plurality of refrigerant pipes, drain pipes, and wiring pipes are housed inside the heat retaining cover member for preventing or suppressing dripping of condensed water. Further, at this time, in the present embodiment, with either the surface of a single-layer nonwoven fabric or the surface of the first layer or the second layer of the laminated nonwoven fabric as the outer surface, the outer peripheral surface shape of the heat retaining cover member for preventing or suppressing dripping of condensed water is a substantially cylindrical cross-sectional shape. The refrigerant pipe, the drain pipe, and the wiring are surrounded by the heat retaining cover member so as to be housed inside the heat retaining cover member for preventing or suppressing dripping of condensed water, whereby the components installed in the pipe are housed inside the heat retaining cover member for preventing or suppressing dripping of condensed water. As a result, even if condensed water is generated on the outer surface of the heat retaining cover member 5 for preventing or suppressing dripping of condensed water, which is the outermost layer of the piping structure 40, dripping of the condensed water can be preferably suppressed or prevented.

[0058] The above has been described with respect to the piping structure of the heat exchanger. However, the cover member of the present invention is not limited to the piping of the heat exchanger, and a polyethylene-based resin foam surface is attached to the outside of the duct for the heat exchanger so as to cover the outer peripheral surface of the duct and used as a structure in which the cover member is attached to the outer periphery of the duct. Thus, even when the cover member of the present invention is attached to the outer peripheral surface of the duct and used as a duct structure, the effect of preventing or suppressing dripping of condensed water on the duct surface can be expected as in the case of the piping of the heat exchanger.

Example

[0059] <Measurement method of product characteristics and basic physical properties of nonwoven fabric> (Nonwoven fabric thickness) Nonwoven fabric used in the test is , those with a thickness ranging from 0.66 mm to 1.22 mm were used. The nonwoven fabric thickness used in the test was measured based on the JIS method using a nonwoven fabric thickness measuring instrument (disc plane measuring element with a diameter of φ56.4 mm) capable of the same measurement as Method A of the measurement method described in the JIS general nonwoven fabric measurement method (JIS L1913:2010). The measurement of the nonwoven fabric thickness was performed three times, and the average value was taken as the measured value. When the first layer of the laminate was peeled, the nonwoven fabric deformed during peeling, and the nonwoven fabric thickness during lamination could not be maintained. ki Therefore, the test material was cut with a fine cutter, and the SEM observation of the cross-sectional nonwoven fabric thickness direction surface was performed and measured by comparison with the scale in the SEM. Three test pieces were prepared for the measurement, and the three measurement results were used as the nonwoven fabric thickness of the first layer. The thickness of the second layer was obtained by subtracting the thickness of the first layer from the total thickness of the nonwoven fabric.

[0060] (Fiber diameter, basis weight) For the fiber diameter of the nonwoven fabric, 20 points were arbitrarily selected from the fiber images of the SEM, and the average fiber diameter (number average) was calculated using image processing software. Here, the average fiber diameter of the nonwoven fabric used in the present invention is 16.67 μm to 35.25 μm. The basis weight can be obtained by cutting a 10 cm × 10 cm square test piece from the raw material, measuring the mass and area of each, and using the following formula. The measurement was performed three times repeatedly, and the average value was taken as the basis weight. Basis weight (g / m 2 ) = 10000 × test piece mass (g) / test piece area (cm 2 )

[0061] (Water retention parameter: Figure 7) The water condensed on the nonwoven fabric surface competes between diffusion due to surface tension and water absorption. Therefore, especially to prevent the dripping of the condensed water under gravity, the water absorption and diffusion ability to suck the water upward against gravity is important, and the balance of these functions becomes a problem. In the present invention, in order to evaluate this, an original test method was developed and used in the test to obtain the water retention parameter including the water sucking ability under gravity. Here, the water retention parameter test is a strip-shaped test piece made of a non-woven fabric containing superabsorbent resin fibers of each mixing ratio with a predetermined size, with a marking line provided across the width direction on the surface at the intermediate position in the longitudinal direction, in a horizontal state, and a test liquid colored on the marking part. to A predetermined amount was dropped, and immediately after the dropping, the test piece was held vertically for 5 minutes. Then, the ascending distance from the marking line of the test piece to the arrival point of the test liquid upward and the descending distance from the marking line of the test piece to the arrival point of the test liquid downward were obtained by measurement. The average ascending distance was divided by the average descending distance, and the ratio was taken as the water retention parameter. This value represents the ratio of the lengths of the ascending and descending parts. The larger the value, the better the performance of the "retention force for retaining water against gravity". If this retention force is high, it is considered that the condensation water dripping at a low position can be suppressed. The water retention parameter was determined for the non-woven fabrics made in the examples and comparative examples (including superabsorbent resin fibers of each mixing ratio adopted in the examples and comparative examples as necessary). manufacture They were made into strip-shaped test pieces 41 (Figure 7) with dimensions of length 200 mm × width 25 mm, and a marking line 45 was provided across the width direction on the surface at the intermediate position in the longitudinal direction. At this time, the thickness of the non-woven fabric was set to the thickness of each test material adopted in the examples and comparative examples. With the above test piece in a horizontal state, 400 μL of the test liquid colored on the marking part was dropped, and immediately after the dropping, the test piece 41 was held vertically for 5 minutes. Then, the ascending distance 43 from the marking line of the test piece to the arrival point of the test liquid upward and the descending distance 44 from the marking line of the test piece to the arrival point of the test liquid downward were obtained by measurement. Furthermore, the average value in the test piece width direction of the upward rise distance (the rise distance to the upward test liquid arrival point) 43 from the reference line of the test piece (the average value of the rise distances of #1 to #5) was divided by the average value in the test piece width direction of the downward fall distance (the fall distance to the downward test liquid arrival point) 44 from the reference line 45 of the test piece (the average value of the fall distances of #1 to #5), and the ratio obtained by dividing this average rise distance by the average fall distance was used as the water retention parameter. Since there is a distribution in the width direction as shown in Fig. 7, the measurement positions were equally divided in the width direction, the average values at 5 locations were obtained, and the value obtained by dividing the average length of the upward movement [mm] by the average length of the downward movement [mm] was calculated and defined as the retention force parameter against gravity. The measured values in the table are the average values obtained by repeating this measurement 5 times. This value represents the ratio of the lengths of the upward movement 43 and the downward movement 44. The larger this value is, the better the performance of the "retention force for retaining moisture against gravity". If this retention force is high, it is considered that the condensation water dripping at a low position can be suppressed. Therefore, regarding performance such as preventing or suppressing the dripping of condensed water, it is desirable that the water retention parameter of the moisture is larger. However, in reality, it is considered that for preventing or suppressing the dripping of condensed water, in addition to the water retention parameter of the moisture, the water retention capacity of the non-woven fabric has a complementary effect.

[0062] (Water retention amount evaluation in an evaporation environment: Fig. 8) In the present invention, considering the water retention function of the non-woven fabric containing the superabsorbent resin fiber, in addition to the previous water retention parameter test, since there is no test standard for the test to determine the water retention amount in an evaporation environment, the following water retention test in an evaporation environment was devised and conducted. The method for evaluating water retention is as follows (see Fig. 8). First, a heat-insulating cover member 5 composed of a resin foam 2 and a non-woven fabric 3 was wound around the outer periphery of a pipe 11 with a diameter of 25 mm cut to 150 mm to form the heat-insulating cover member 5, and both ends of the heat-insulating cover member 5 were fused to create a water retention test specimen 100. At this time, the thickness of the resin foam 2 was set to 10 mm. For the non-woven fabric, the thickness of each test specimen created in the examples, comparative examples, and conventional example materials 1 was used, and if necessary, it was made to contain superabsorbent resin fibers or the like at the same ratio as the mixing ratio of each test specimen. Next, the test material The test specimen 100 was placed in a transparent resin container 51 having a predetermined clearance so that a test piece could be inserted as shown in the figure, and the "container + test specimen mass" was measured with an electronic balance (scale) 53. 20 g of water 52 was put into the container 51 containing the test specimen 100, and the total mass of "container + test specimen + 20 g of water" was measured with an electronic balance. The thermostatic and humidistatic chamber was set to 23°C × 30%, the container containing the water 52 and the test specimen 100 was inserted into the thermostatic and humidistatic chamber, and it was held in the thermostatic and humidistatic chamber for 6 hours. After 6 hours had passed, the container 51 in which the test specimen 100 was immersed was taken out, and the "mass at the time of removal", "remaining water volume", and "mass after water removal" were measured with the electronic balance 53. Here, the water retention amount can be obtained by tilting the container to remove water from the mass at the time of removal at the end of the test to obtain the mass after water removal, and then subtracting the mass of the container and the sample before the test from this. The evaporation amount is the value obtained by subtracting the mass at the time of removal from the total mass before the start of the test.

[0063] (Various specifications of the test specimen, water retention parameter, and test results of the water retention test) The test results of the test specimens are shown in Table 1.

[0064]

Table 1

[0065] (Annotations to the table) SAF: Super Absorbent Fiber (superabsorbent resin fiber) Bell Oasis (trade name), manufactured by Teijin Frontier Co., Ltd. Lanseal (trade name), manufactured by Toyobo Co., Ltd. PE: Polyethylene PET: Polyethylene terephthalate Foam: Polyethylene resin foam, expansion ratio 30 times, thickness 10 mm The numerical values or % shown in terms of the mixing ratio (%) of SAF all mean mass %.

[0066] (Description of test specimens) The description of test specimens will be given below. In addition to the description of test specimens, in the description of the evaluation test results of these test specimens, the names of the resins constituting the fibers are abbreviated as PE, PP, PET, SAF, etc. for simplicity. In the present invention, the mixing ratio is defined as the mixing ratio of the superabsorbent resin fibers with respect to the total weight of the layer containing the superabsorbent resin fibers.

[0067] First, the production of the resin foam will be described. As the polyethylene-based resin, a mixed resin obtained by mixing low-density polyethylene and high-density polyethylene at a mass ratio of 4:6 was prepared. For the low-density polyethylene, F120N manufactured by Ube Maruzen Polyethylene Co., Ltd. was used, and for the high-density polyethylene, HD1300 manufactured by Nippon Polyethylene Co., Ltd. was used. Further, as the foaming agent, 16 parts by mass of Vinhole AC#LQ manufactured by Yonghe Chemical Industry Co., Ltd. and, as the crosslinking agent, 0.8 parts by mass of Parkmill D manufactured by NOF Corporation were added respectively. The obtained raw material composition was extruded at 120 to 150 °C to obtain a base sheet for foaming, and then continuously foamed to a thickness of 10 mm and an expansion ratio of 30 times in a heating furnace at 200 to 230 °C. After that, by passing through rolls, the dimensions and surface properties of the foam were adjusted, and then it was cut into a predetermined width according to the diameter of the pipe to be wound.

[0068] The inventive example materials are a single-layer product composed of a single layer of non-woven fabric in which thermoplastic resin fibers and superabsorbent resin fibers are mixed at a predetermined mixing ratio, and a laminate in which only a skeleton resin fiber layer containing no superabsorbent fibers is laminated on this single-layer product use the reference example material single-layer product and this single-layer product with only a skeleton resin fiber layer not containing superabsorbent fibers laminated thereon as the invention example material There is a laminated product. For the single-layer product, as the skeletal resin fiber, for the core-sheath structure fiber using PET of PET / PE as the core part and PE as the sheath part, a high water-absorbing resin fiber (Bell Oasis) is changed at a predetermined ratio and heat-sealed to the surface of a polyethylene resin foam. Samples with mixing ratios of 10% by mass, 25% by mass, 40% by mass, and 75% of the high water-absorbing resin fiber with respect to the non-woven fabric layer containing the high water-absorbing fiber are prepared as the reference example material Examples 1, 2, 3, and 4. Here, although it is a single-layer product, as the skeletal resin fiber, a fiber with a core-sheath structure of PET and PP / PE, and 50% by mass of Lansil other than Bell Oasis is used as the high water-absorbing resin fiber is reference example material designated as 5. In the table, in the item of the mixing ratio (%) of SAF of Test Specimen 5, 30%, 20%, and 50% are shown, which represent the mixing ratios as described above, indicating 30% by mass, 20% by mass, and 50% by mass respectively.

[0069] In contrast as the invention example material The laminated product is obtained by laminating a non-woven fabric consisting only of a skeletal resin fiber layer on the above single-layer non-woven fabric. Here, the layer consisting only of the skeletal resin fiber is designated as the first layer, and the non-woven fabric layer containing the high water-absorbing resin of the laminated non-woven fabric is designated as the second layer. as the invention example material The mixing ratio of the second layer, which is the non-woven fabric containing the high water-absorbing resin fiber in the non-woven fabric of the laminated product, is the same as that of the single-layer product, with mixing ratios of 10% by mass, 25% by mass, 40% by mass, and 75% respectively. Samples with the first layer consisting only of a skeletal structure non-woven fabric with a core-sheath structure of PET / PE attached thereto are designated as Invention Example Specimens 6, 7, 8, and 9 respectively. Invention Example Specimen 10 has the same mixing ratio of 40% by mass for the second layer, which is the non-woven fabric containing the high water-absorbing resin fiber in the non-woven fabric of the laminated product, as Invention Example Specimen 8. However, the basis weight of the non-woven fabric is increased from 48 g / m 3 to 63 g / m 2 of Invention Example Specimen 8. In Invention Example Specimen 11, a mixed fiber of PET and PET / PP core-sheath structure fiber is used as the skeletal resin fiber, changed to Lansil, added at a mixing ratio of 50% by mass, and further the basis weight of the non-woven fabric is increased to 168 g / m 2 which is large. As the arrangement form of the nonwoven fabric of each laminated product, both cases were evaluated: the case where the first layer (not containing superabsorbent resin fibers) is the outer layer and the second layer (containing superabsorbent resin fibers) is the inner layer (arrangement A), and the case where, conversely, the first layer (not containing superabsorbent resin fibers) is the inner layer and the second layer (containing superabsorbent resin fibers) is the outer layer (arrangement B).

[0070] As the conventional example material, a heat-insulating cover member in which a 100-μm-thick PE film (manufactured by the company itself) was fused to the surface of a polyethylene resin foam was used as the conventional example material 1. Also, as comparative example materials, materials having the same structure as the inventive example material, having the same structure as a single-layer product, with a mixing ratio of superabsorbent resin (Verona Sis) in the nonwoven fabric of 5% by mass, and laminated products with a mixing ratio of the above-mentioned Verona Sis of 5% by mass and 85% by mass were used as comparative example material 1 and comparative example materials 2 and 3, respectively. Here, as comparative example materials, for both single-layer products and laminated products, it is for confirming whether there is a dew condensation prevention or suppression effect even at a low mixing ratio of 5% by mass, and for materials with a mixing ratio of 85% by mass, since there is a large amount of superabsorbent nonwoven fabric, the dew condensation prevention or suppression effect is sufficient, but it is for confirming whether there are problems with the fusibility and foamability with the polyethylene foam. Also, since the materials with a higher mixing ratio in the comparative example materials are considered to show the same behavior for single-layer products and laminated products, only the laminated products were confirmed. Furthermore, three types of general-purpose nonwoven fabrics composed only of skeletal resin fibers not containing superabsorbent resin were added to the comparative example materials and used as comparative example materials 4 to 6. Here, in the nonwoven fabrics of comparative example materials 5 and 6, in addition to the skeletal resin fibers, nonwoven fabrics added with ordinary thermoplastic resin fibers, water-absorbing fibers such as rayon and pulp, and water-absorbing materials were prepared for the comparison between ordinary water-absorbing fibers and water-absorbing materials and superabsorbent resin fibers. Specifically, a nonwoven fabric having a core-sheath structure of PET / PE, with the surface of the PE in the sheath part hydrophilically treated, was used as comparative example material 4. Also, a nonwoven fabric composed of a mixed fiber of PE fiber and rayon fiber with a mixing ratio of rayon fiber of 40% by mass was used as comparative example material 5. Furthermore, a nonwoven fabric composed of a mixed fiber of PET / PE core-sheath structure fiber and pulp with a pulp mixing ratio of 30% by mass was used as comparative example material 6.

[0071] (Measurement and evaluation items of nonwoven fabric and their contents) The measurement and evaluation items of the nonwoven fabric used in the test are the fiber diameter, product thickness, basis weight, water retention parameter, and water retention property. Here, the fiber diameter of the test material describes both the fiber diameter of the base resin fiber of the substrate and the fiber diameter of the superabsorbent resin fiber (SAF). The product thickness is of the reference example material In the case of a single layer, the overall thickness of the nonwoven fabric is described. When the nonwoven fabric is of the invention example material In the case of a laminate, the overall thickness of the laminated nonwoven fabric and the thickness of the diffusion layer, which is the first layer, are described with parentheses below the overall thickness. Therefore, since the thickness of the second layer can be obtained by subtracting the thickness of the first layer from the overall thickness as described above, the thickness of the second layer is not described in the table. Also, the basis weight is of the reference example material In the case of a single-layer product, it represents the basis weight of the entire nonwoven fabric. of the invention example material In the case of a laminate, the basis weight of the entire nonwoven fabric is described in the upper row, and the basis weights of the first and second layers are described in the lower row. The left side is the second layer, and the right side is the first layer. This is because there are two cases: (A) when the first layer is arranged on the outside and the second layer is arranged on the inside, and (B) when the second layer is arranged on the outside and the first layer is arranged on the side of the inner fusion or adhesion surface. Here, it is considered that arranging the first layer consisting only of the base resin fiber without superabsorbent resin fiber on the outside of the nonwoven fabric has a more dominant effect as the diffusion evaporation layer of the first layer, but it may also pass through a part of the superabsorbent resin layer. When only considering water retention, the case where the diffusion layer with the reverse arrangement is arranged on the side of the inner fusion or adhesion layer, with the superabsorbent resin fiber arranged on the outside compared with the case of is also considered to be superior, so both arrangements were evaluated. Hereinafter, is the invention example material Regarding the arrangement of the laminate, when laminating the nonwoven fabric on the surface of the PE resin foam, the arrangement when the first layer, which is a nonwoven fabric formed only of the base resin of the substrate, is arranged in the outer layer is referred to as arrangement (A) (Fig. 5(a)), and the arrangement when the second layer containing superabsorbent fibers is arranged in the outer layer is referred to as arrangement (B) (Fig. 5(b)). The water retention parameter and water retention amount in Table 1 show the test results for the case where the outer layer is arrangement (A) in the upper row and the case where the outer layer is arrangement (B) in the lower row. The mixing ratio was defined as the mixing ratio of the superabsorbent resin fibers to the total weight of the superabsorbent resin-containing layer as described above.

[0072] (Range of fiber diameter, product thickness, basis weight) In the examples, the fiber diameter of the thermoplastic resin fibers was tested in the range of 16.67 μm to 25.41 μm. The fiber diameter of the SAF was tested in the range of 23.74 μm to 35.25 μm in the examples. Specifically, for the superabsorbent resin fibers (SAF), the fiber diameter of Bellows is 35.25 μm, and the fiber diameter of Lanshire is 23.74 μm. Lanshire has a core-sheath structure in which SAF is formed on the outer peripheral part of the core material as the core material of the acrylic fiber. In the examples, the product thickness was tested in the range of 0.77 mm to 1.22 mm. For the laminate, as described above, the thickness of the first layer (layer without SAF) is shown in parentheses. Regarding the basis weight, in the examples, 38 g / m 2 ~168 g / m 2 was tested. In the case of the laminate, as described above, the basis weight of the entire non-woven fabric is described in the upper row, the basis weight of the first layer (layer without SAF) is described on the right side of the lower row, and the basis weight of the second layer (layer with SAF) is described on the left side in order.

[0073] (Test results of water retention parameter and water retention test of non-woven fabric) · Test results of the inventive example materials: Looking at the results of the inventive example materials, reference example material From 1 to reference example material For the test results of the single-layer products from 5, the water retention parameter is 0.78 to 1.06, and the water retention amount in the water retention test is 7.89 g to 19.98 g. Also, In contrast Since Inventive Example Materials 6 to 9 are laminates, there are also differences depending on whether the liquid droplet application surface in the water retention test is the first layer (diffusion and evaporation promotion layer composed only of base resin fibers) or the second layer (layer containing superabsorbent resin fibers in the base resin fibers). In this test, the droplet application surface corresponds to the outer surface of the heat insulation cover member of the product. When the water retention parameter is such that the dripping surface is a layer containing highly water-absorbent resin fibers in the second-layer base resin fibers, the water retention parameter is 0.74 to 0.98, showing results close to those of the single-layer product in the test. The reason is that since the structure of the non-woven fabric of the second layer, which is the dripping surface, contains highly water-absorbent resin fibers in the base resin fibers and has the same structure as the single-layer product, when the mixing ratio of the highly water-absorbent resin fibers is the same, it is considered that the diffusion evaporation and water retention of the water absorbed by the non-woven fabric show almost the same behavior. Conversely, regarding the water retention parameter, when the first layer is not arranged on the dripping surface and is arranged on the back surface of the non-woven fabric layer containing highly water-absorbent resin fibers, it can be seen that the influence of the diffusion and transpiration promoting layer composed only of the base resin fibers without highly water-absorbent resin fibers, which is the first layer, is small. Conversely, when the dripping surface is a diffusion and transpiration promoting layer composed only of the first-layer base resin fibers, the water retention parameter is 1.02 to 1.16, and the water retention parameter is larger than 0.74 to 0.98 when the dripping surface is the second layer as described above. From this, in terms of the arrangement relationship between the non-woven fabric and the resin foam, it can be seen that from the viewpoint of diffusion and transpiration properties, it is desirable to arrange the first layer (diffusion and transpiration promoting layer composed only of base resin fibers) facing the outer surface. Also, when comparing the water retention parameters of the single-layer product and the case where the dripping surface is the second layer, the water retention parameter of the single-layer product is 0.78 to 1.06, and when the dripping surface is the second layer, it is 0.74 to 0.98. Although there are some differences, they are considered to be almost the same. The reason is considered to be that the dripping surface is formed by a non-woven fabric layer containing highly water-absorbent resin formed by the base resin fibers and highly water-absorbent resin fibers that form the skeleton in both cases. Here, invention example material Regarding the water retention of 6 to invention example material 9, reference example material 1 or from the reference example Compared with Material 5 (7.89 g to 19.98 g), although the water retention parameter of these materials is excellent, it was found that the water retention property decreased slightly compared to Reference Material 1 to Reference Material 5. Also, regarding which of the first layer and the second layer is arranged facing the outside of the product, when the first layer is arranged facing the outside, since the diffusion and transpiration promoting layer is arranged facing the outside, the water retention parameter is much better than when the second layer is arranged facing the outside. However, since the layer having water retention property is arranged on the back surface, the water retention property was slightly inferior to the result of the water retention parameter. (Arrangement with the first layer on the outside: 7.22 to 15.88 g, Arrangement with the second layer on the outside: 7.58 to 16.45 g) Furthermore, Invention Example Material 10 has the same high water-absorbing resin fiber as Invention Example Material 8 at a mixing ratio of 40% by mass, and the basis weight of the layer containing the high water-absorbing resin fiber is increased from 30 g / m 2 to 45 g / m 2 It can be seen that Invention Example Material 10 has improved both the water retention parameter and the water retention property compared to Invention Example Material 8 due to the effect of the increase in the basis weight of the high water-absorbing resin fiber layer. Also, Invention Example Material 11 uses a mixed fiber of PET and PET / PP core-sheath structure fiber as the resin fiber, changes the high water-absorbing resin fiber to Ver Oasis, adds Lansil at a mixing ratio of 50% by mass, and further sets the basis weight of the non-woven fabric to 168 g / m 2 In this case, due to the large basis weight, the content of the high water-absorbing resin fiber is higher than that of Invention Example Material 9, and the water retention amount is significantly increased compared to other laminated products. From the above,[[]] reference example material Regarding the single-layer products of 1 to 5, the arrangement with the first layer of the laminated products of Invention Example Materials 6 to 11 as the outer surface (described at the upper part of each column in the table) and the arrangement with the second layer of the laminated products as the outer surface (described at the lower part of each column in the table), for the 17 kinds of cover members, all materials satisfy a water retention parameter test result of 0.70 or more for the non-woven fabric, and at the same time,[[]] the evaporation amount obtained under predetermined conditions is 8.88 g or more, the result of the water retention test satisfies a result of 7.0 g or more. Also, according to the above test results, it can be seen that the laminated product with the first layer arranged on the outer surface has the largest water retention parameter. Conversely, the water retention amount in the water retention test result of the present invention is of the reference example material the result that the single-layer product is slightly larger than the laminated product. Here,[[]]of the reference example material When comparing the single-layer product and the laminated product, the laminated product of the reference example material has a lower basis weight of the entire nonwoven fabric than the single-layer product, less than 100 g / m 2 Even when it is 100 g / m² or less, both the water retention parameter and the water retention test result satisfied the above values.

[0074] · Conventional example material: Since the conventional example material 1 is a PE film and not a nonwoven fabric, the water retention parameter test and the water retention test were not conducted. · Test results of comparative example materials: Next, looking at the results of the comparative example materials, for comparative example material 1, the mixing ratio of the superabsorbent resin fibers is as low as 5% by mass, and the improvement effect of the water retention parameter due to water absorption cannot be expected. However, since it has basic diffusion and transpiration capabilities, the water retention parameter just exceeded 0.70, but the result of the water retention test was less than 7.0 g due to the low mixing ratio of the superabsorbent resin fibers. Comparative example material 2 is a laminate, but like comparative example material 1, the mixing ratio of the superabsorbent resin fibers is as low as 5% by mass. As a result, similar to comparative example material 1, the water retention parameter slightly exceeded the threshold value, but the water retention was less than the threshold value of 7 g. In contrast, for comparative example material 3, since the mixing ratio of the superabsorbent resin fibers is as high as 85% by mass, the water retention parameter is exceeded 0.70, and the result of the water retention test also exceeded 7.0 g. However, since the mixing ratio of the base resin fibers forming the skeleton is too high at 85% by mass, the fusion surface or the adhesive surface with the PE resin foam is unstable. Furthermore, due to the swelling and gelation of the superabsorbent resin fibers after water absorption, the shape of the surface of the nonwoven fabric of the cover member changed and became unstable. As a result, comparative example material 3 was judged as unqualified. Comparative example material 4 is a non-woven fabric composed only of fibers with a core-sheath structure of PET / PE. Although it does not contain superabsorbent resin fibers, hydrophilic treatment is applied to the surface of the fibers. Therefore, the water retention parameter exceeded the threshold, but the water retention amount was below the threshold. Also, comparative example material 5 is a non-woven fabric made of a mixed fiber of PE fiber and rayon fiber, with the mixing ratio of rayon fiber being 40% by mass. For this comparative example material 5, the water retention parameter was below the target, but considering that rayon was mixed, its water retention property is thought to have exceeded the target. As a result, neither the water retention parameter nor the water retention property exceeded the target. Also, comparative example material 6, which is a non-woven fabric made of a mixed fiber of PET / PE core-sheath structure fiber and pulp, had a water retention parameter that exceeded the target, but although pulp was mixed, its water retention property did not reach the target. As described above, except for comparative example material 3 with a high content of superabsorbent resin fibers, in the comparative example materials, either the water retention parameter or the water retention amount in the water retention property test, or at least one of them, did not meet the threshold and failed. Comparative example material 3 had a high content of superabsorbent resin fibers and a low content of the base resin fibers that form the skeleton. Therefore, the fusion surface or the adhesive surface at the interface with the PE resin foam became unstable, and the surface shape of the non-woven fabric also became unstable, resulting in failure.

[0075] To prevent the dripping of condensed water, in addition to water retention, there is transpiration from the surface of the non-woven fabric. Although not particularly shown in Table 1, the evaporation amount of the test example materials for single-layer products reference example material ranged from 5.08 g to 11.48 g for 1 - 5, and for invention example materials 6 - 11, when the outer layer was the first layer (diffusion and transpiration promotion layer composed only of base resin fibers), it was from 9.24 g to 10.76 g. Furthermore, when the outer layer was the second layer (layer containing superabsorbent resin fibers in the base resin fibers), it was from 8.88 g to 10.24 g. It can be seen that not only does the non-woven fabric retain water, but the transpiration effect from the surface of the non-woven fabric contributes to the suppression of condensed water. reference example material has a transpiration effect of at least 5.0 8 g or more, and the transpiration effect in the case of only laminated products is 8 .88 g or more, and when the first layer is arranged on the outer surface, it is 9. 24An evaporation effect of g or more is recognized. Moreover, although the evaporation effect of the laminate is large, it is considered that this effect is superimposed on the water retention effect, thereby improving the effect of preventing or suppressing the dripping of condensed water.

[0076] (Purpose and content of the dripping confirmation test for condensed water) From the results of the water retention parameter test and the water retention test of the non-woven fabric, the water retention parameter of the non-woven fabric is 0.70 or more, obtained under the predetermined conditions defined in the present invention water retention Since it is considered that a heat-insulating cover member for preventing or suppressing the dripping of condensed water, in which a non-woven fabric that simultaneously satisfies a water retention amount of 7.0 g or more in the water retention property test is fused or adhered to the surface of a resin foam, has excellent dew condensation prevention performance, a dripping performance confirmation test of condensed water was conducted by using these cover members and comparing them with conventional example materials. Here, it has already been confirmed that dripping of condensed water does not occur in the horizontal pipe of the product of the present invention, but it is necessary to confirm the dripping performance of condensed water in pipes other than the horizontal pipe. In the dripping confirmation test of condensed water, among the horizontal pipe, inclined pipe, vertical pipe, and bent pipe, the vertical pipe that is most easily affected by gravity was selected for the test. Furthermore, when using a glasses-shaped pipe, condensed water is retained in the recess formed near the connection part of the glasses-shaped pipe rather than the single pipe in terms of the pipe structure, and the retained condensed water is easily affected by gravity and becomes water droplets and drips, so the test conditions become more severe. Therefore, this structure was selected. In addition, in the measurement test of the actual dripping amount of condensed water, with the glasses-shaped pipe as the vertical pipe, it was installed in a large constant temperature and humidity chamber, and the refrigerant was flowed through the pipe, and under the actual operating environment of the heat exchanger, the constant temperature and humidity tank The set conditions were set to a severe environmental condition of 35°C × 90%RH, and an exposure test was conducted for 1080 minutes (18 hours). The reason is that the environmental conditions for installing the actual heat exchanger vary from construction site to construction site, and the occurrence of dew condensation dripping is different. Therefore, even if dew condensation dripping does not occur under the predetermined setting environment, it is considered that dew condensation dripping may occur under more severe environmental conditions. Furthermore, if the test is conducted in a low-humidity environment as the actual installation environment, there is a possibility that the performance of preventing or suppressing dew condensation dripping between materials cannot be evaluated because no dripping occurs. is However, since dripping occurs in a harsh environment, the performance of preventing or suppressing dew condensation dripping between materials can be evaluated. Furthermore, dew condensation dripping does not occur in the horizontal pipe of the product of the present invention.

[0077] (Dew condensation dripping confirmation test under severe environmental conditions with a vertical pipe using the goggle-shaped pipe on the indoor unit side: Figure 9) This is a piping configuration diagram schematically showing the dew condensation dripping confirmation test under severe environmental conditions of a vertical pipe using the goggle-shaped pipe on the indoor unit side. Specifically, a 600 mm vertical pipe (indoor unit side pipe) 71 (Figure 9) from the ceiling space to the indoor unit side, an intermediate pipe 73, and a descending pipe (outdoor unit side pipe) 72 are connected, and the device is made in a large constant temperature and humidity chamber. manufactured The device was set under the setting conditions of the constant temperature and humidity phase at a high humidity condition of 35°C × 90% RH, and a severe test was conducted to confirm dew condensation dripping at a refrigerant temperature of 5°C for the piping for 1080 minutes (18 hours). Here, for the test, a pair of pipes with a diameter of 6.35φ × wall thickness of 0.85 mm and a diameter of 9.52φ × 0.80 mm were used. The heat insulation cover member 5 for preventing or suppressing dew condensation dripping of the present invention was wound around the outer periphery of each pipe. After thermally fusing the contact portions of the resin foam 2 and the non-woven fabric 3 of the end faces of the cover member to each other, the two pipes were further thermally fused to complete the goggle-shaped pipe 20 (refer to Figure 2) and used for the test. At this time, the heat insulation cover member for preventing or suppressing dew condensation dripping was wound made The outer diameter of each pipe is about 28 mm and 31 mm. Also, the dew condensation was measured by an electronic balance (scale) 75 for the dripping mass in a tray with a length of 400 mm in the length direction of the pipe. From the test results of the vertical pipes, at least the inventive example materials showed an improvement effect of 30% or more compared to the test result of 48 g of the vertical pipes of the conventional example material 1, and the dripping amount of the dew condensation water became 33.6 g or less.

[0078] (Nonwoven fabric bonding property and shape stability test) The state of the bonding interface between the nonwoven fabric (thermoplastic resin fiber) and the resin foam (polyethylene resin foam) of the formed heat insulation cover member was visually confirmed. Based on this, those without floating on the bonding interface were judged as qualified, and those with problems in the adhesion state of the interface such as floating or even slight peeling occurring on the interface were judged as unqualified. For the superabsorbent resin fiber after the test in Those with not much change in the shape of the nonwoven fabric due to water absorption of water were judged as "○" qualified, and those with a large change in the shape of the nonwoven fabric and a large change in the shape of the nonwoven fabric before water absorption were judged as unqualified "×".

[0079] (Dripping test of condensed water on vertical pipes and test results of bonding stability and shape stability of nonwoven fabrics under severe environmental conditions of test materials) Table 2 shows the test results of the dripping test of condensed water and the bonding stability and shape stability of nonwoven fabrics under severe environmental conditions of the test materials.

Table 2

[0080] In the results of the "vertical pipe dew condensation water dripping test" in the table, although the nonwoven fabric is a laminated product, those with the test results shown in one line (inventive example materials 7, 9, 10, 11) show the test results when arranged in configuration A (when the layer without superabsorbent resin fiber is the outer layer and the layer with superabsorbent resin fiber is the inner layer). The test results of inventive example materials 6 and 8 are shown in two lines because although the nonwoven fabric is a laminated product, those with the same layer configuration as above in configuration A are shown in the upper line, and the outer layer and the inner layer are reversed te The test results of configuration B (when the layer with superabsorbent resin fiber is the outer layer and the layer without superabsorbent resin fiber is inside arranged in the layer) tested are shown in the lower line. The same applies to comparative example materials 2 and 3.

[0081] As described above, the "vertical pipe condensation water dripping test" was carried out by measuring the mass of the amount of dripping condensation water in a severe test of being exposed for 16 hours under environmental conditions of a temperature of 35°C and a humidity of 90%. As a result, for the amount of dripping condensation water of the inventive example materials, in each case, an improvement effect exceeding at least 30% was recognized compared to the conventional example materials. In contrast, for the comparative example materials excluding Comparative Example Material 3 containing 85% of the superabsorbent resin fibers, the improvement effect of the amount of dripping condensation water of the comparative example materials was less than 30%. · Test results of conventional example materials: Regarding the amount of dripping condensation water of the reference conventional example materials, since Conventional Example Material 1 only has a PE resin film fused to the surface of the PE resin foam, dripping of 48 g of condensation water occurred. · Test results of inventive example materials: Reference example materials 1 to 5 and invention example materials The results of the condensation water dripping tests from 6 to 11 are , which is a reference example material For single-layer products, which is an invention example material both laminated products have a non-woven fabric layer containing a superabsorbent resin, and when the content of the superabsorbent resin fibers in this non-woven fabric layer satisfies a composition of 10% by mass to 80% by mass, and the content of the thermoplastic resin fibers, which are the fibers forming the remaining skeletal structure of this non-woven fabric, is 20% by mass to 90% by mass, which is a reference example material the amount of dripping condensation water of the single-layer products is 3.8 g to 32.5 g, and the improvement rate compared to Conventional Example Material 1 is recognized to be an improvement of 32.3% to 92.1%. Also, which is an invention example material in the case of laminated products, it is 0.8 g to 28.4 g, and the improvement rate compared to Conventional Example Material 1 is 40.8% to 98.3%. which is a reference example material For single-layer products, which is an invention example material both laminated products exceeded at least 30%. At this time, which is an invention example material In the comparison between laminated products and of the reference example material single-layer products, which is an invention example material The amount of dripping condensed water in the laminate was small and excellent. This is presumably because the laminate has a layer that promotes diffusion and evaporation without separately containing highly water-absorbent resin fibers, which promotes the diffusion and evaporation of condensed water. Also, in both the single-layer product and the laminate, as the content of highly water-absorbent resin fibers increases, the amount of dripping condensed water tends to decrease. This is due to the combined effects of the increase in the water retention capacity of the highly water-absorbent resin fibers caused by the increase in the content of highly water-absorbent resin fibers, and the secondary induction of the promotion effect of the diffusion and evaporation effect of condensed water due to the decrease in the amount of condensed water not retained by this, with these effects being superimposed. Regarding the arrangement of the layer that promotes diffusion and evaporation and the layer containing highly water-absorbent resin fibers in the laminate, from the results of Test Specimens 6 and 8, arranging the layer that promotes diffusion and evaporation (the first layer) on the outside was superior in terms of having a smaller amount of dripping condensed water than arranging the layer that promotes diffusion and evaporation on the inside. However, arranging the first layer on the outside slightly reduces the water retention property, but the evaporation effect can be increased significantly due to the improvement of the water retention parameter. As a result, it is considered that the amount of dripping condensed water decreased. · Test results of comparative specimens: Comparative Specimen 1 is a single-layer base resin fiber mixed with 5% by mass of highly water-absorbent resin fibers. Therefore, the mixing amount of the highly water-absorbent resin fibers is small, and 42.5 g (improvement rate: 11.5%) of dripping condensed water occurred. In Comparative Specimen 2, 5% by mass of highly water-absorbent resin fibers was mixed with the laminated base resin fibers. As a result, 43.9 g (improvement rate: 8.5%) of dripping condensed water occurred. As described above, due to the structural reason that the conventional specimen 1 used as the reference before improvement has no non-woven fabric, the test results were poor because both the heat insulation property and the water retention property were insufficient. Also, when comparing Comparative Specimen 1 and Comparative Specimen 2 with the invention specimen at a mixing ratio of 5% by mass of highly water-absorbent resin fibers for both the single-layer product and the laminate, the mixing ratio of the highly water-absorbent resin fibers in these test specimens is low, resulting in insufficient water retention property, and the amount of dripping condensed water exceeds 30%, which is the lower limit of the improvement rate of the invention specimen, and the amount of dripping condensed water increased. In Comparative Example Material 3, 85% by mass of superabsorbent resin fibers was mixed with the laminated base resin fibers. As a result, the mixing ratio of the superabsorbent resin fibers was higher than that of the Invention Example Material. Therefore, in the vertical pipe test, the amount of condensed water generated was 2.6 g (improvement rate: 94.6%), the amount of condensed water generated was the same as that of the Invention Example, and the effect of preventing or suppressing the dripping of condensed water was great. However, since the mixing ratio of the superabsorbent resin fibers is large, the water retention amount is large, but the content ratio of the base resin decreases, so the bonding property of the fusion or adhesion interface between the foam and the non-woven fabric is unstable, and further, the shape of the surface of the non-woven fabric after water absorption also becomes unstable, so it was judged as unqualified "×". In the case of Comparative Example Material 4, it was a non-woven fabric having a PET / PE core-sheath structure, which did not contain superabsorbent resin fibers but was obtained by bonding a non-woven fabric having a hydrophilic treatment on the surface of the core-sheath structure fibers to the surface of the foam. In this case, the dripping amount in the case of the vertical pipe test was 44.5 g (improvement rate: 7.3%), and although the effect of the hydrophilic treatment was somewhat recognized, the test result did not satisfy the improvement rate of 30% of the Invention Example Material. Comparative Example Material 5 was a non-woven fabric made of a mixed fiber of PE fiber and rayon fiber, and contained 40% by mass of rayon fiber based on the total weight of the non-woven fabric. The dripping amount of this material was 41.1 g (improvement rate: 14.4%), and the dripping amount did not reach the improvement rate of 30% of the Invention Example Material. Comparative Example Material 6 was a non-woven fabric made of a mixed fiber of PET / PE core-sheath structure fiber and pulp, and was assumed to contain 30% by mass of pulp based on the total weight of the non-woven fabric. As a result, the dripping amount in the case of the vertical pipe test was 38.8 g (improvement rate: 19.2%). Comparative Example Material 6 was superior to other conventional example materials, but did not reach the minimum improvement rate of 30% of the Invention Example Material.

[0082] In the case of a form in which non-woven fabrics are laminated, the inventive example material 8 is a reference. That is, in the case where the first layer (the layer without SAF) is arranged on the outside and the second layer (the layer with SAF) is arranged on the inside (arrangement (A)), in the vertical pipe test, with the arrangement (A) where the first layer is the outer layer, it was 11.5 g, while for the inverted one, it was 14.3 g, and the improvement rates were 76.0% and 70.2% respectively. From these results, it was found that the arrangement (A) where the first layer is the outer layer tends to be slightly better than the one where the first layer is on the inside and the second layer is on the outside (arrangement (B)).

[0083] (Application to other heat mating pipe covering members of the heat insulating cover member) Using the heat insulating cover member of the present invention, application examples to other heat insulating cover members will be described. Here, as application examples, it is possible to create a covering member for joints that covers the gap between the heat insulating cover members and use it as a covering member for joints, use the heat insulating cover member as an elbow covering member for the bent portion of the heat mating pipe, and use it for covering members for existing pipe covers that are wound around existing pipes and used. Therefore, the heat insulating cover member of the present invention was manufactured and used for the purpose of using it for these members, and the structures of these members will be described.

[0084] · Covering member for joints Here, based on the experimental results in the present invention, a covering member for joints (heat insulating cover member) 65 that can be arranged to cover the gap between a predetermined heat insulating cover member and a heat insulating cover member arranged adjacent to it in the longitudinal direction of the pipe was manufactured (see FIG. 10). This covering member for joints has an adhesive layer 63 provided on one surface (the side opposite to the non-woven fabric 3 of the foam), a release sheet 62 laminated thereon, and the other surface of the foam is covered with a non-woven fabric. Note that the non-woven fabric contains a predetermined amount of highly water-absorbent resin fibers (not shown). FIG. 11 shows two pipe structures 10 arranged in a longitudinally continuous form. A narrow joint 66 is formed between these pipe structures. In this embodiment, the joint is fixed by winding the joint covering member (heat-insulating cover member with adhesive) 65 shown in FIG. 10. By doing so, condensation does not occur at the joint that is not covered by the cover member, and dripping of the condensed water at this part can also be prevented and suppressed.

[0085] · Elbow covering member FIG. 12 is a front view schematically showing an embodiment of an elbow covering member (bent joint) 25. An adhesive or bonding agent is applied to the hatched part. In this bent joint, a narrow pipe storage part 22 and a thick pipe storage part 23 are formed. Refrigerant pipes are arranged in these pipe storage parts 22 and 23, and a 90° bent refrigerant pipe bending member is installed in the middle thereof. At this time, since the elbow covering member is created by press-forming a sheet-like heat-insulating cover member for preventing or suppressing dripping of condensed water, due to the press-forming, the plate thickness of the heat-insulating cover member decreases by 1 - 2 mm depending on the forming part, but the air bubbles are refined accordingly, so the heat insulation performance does not change much. When using the product, the bending part 24 is bent into a valley fold and the adhesives are butted against each other and fixed. Although not shown, in the elbow covering member of the present invention, the contact surface with the pipe is used as the foamed surface, and the outer surface of the elbow covering member is used as the non-woven fabric surface of the present invention, but a non-woven fabric containing highly water-absorbent resin fibers is arranged on the surface of the elbow covering member (bent joint) 25. In addition, in the case of the elbow covering member as well, regarding suppressing or preventing dripping of condensed water, the same effect as that of the heat-insulating cover member for preventing or suppressing dripping of condensed water covering the outer periphery of the straight tubular heat exchanger pipe can be obtained.

[0086] · Cheese member covering member Also, as a similar member, in addition to the elbow covering member used for the bent part, there is a cheese member that branches the pipe in a T shape. Cheese member is, T It is a metal member that branches downward or upward from a portion corresponding to the head portion in a letter shape. Also for this cheese member, although not particularly shown, similar to the elbow covering member, with the T-shaped head portion as a bent portion, it has a branched portion that branches downward or upward, and the entire branched member is surrounded by the bent portion and the branched portion, and a cheese member covering member can be formed with the bent portion as a hinge for an opening. Here, also in the case of the cheese member covering member, regarding the suppression or prevention of the dripping of condensed water, the same effect as that of the heat-insulating cover member for preventing or suppressing the dripping of condensed water covering the outer periphery of the straight tubular heat exchanger pipe can be obtained.

[0087] · A covering member to be placed on an existing conventional pipe cover Figure 13 is a cross-sectional view showing an aspect in which a covering member 68 to be placed on an existing pipe cover is a double winding in which a resin foam covering a refrigerant pipe is separated by a film. Regarding the cross-sectional circle center of the pipe structure of this embodiment, for the existing conventional pipe cover 76, the refrigerant pipe 1 is located most internally, and the resin foam 2 covers it. The resin foam 2 is covered with a resin film 27 such as PE. In a structure using a PE film for this foam, since the PE film has no water retention property, condensation may occur depending on the environmental conditions around the pipe, and the condensed water is likely to drip. Furthermore, the outside of the resin film 27 is covered with the resin foam 2, and then the outermost layer is covered with a non-woven fabric 3. That is, the resin foam 2, the resin film 27, the resin foam 2, and the non-woven fabric 3 together constitute a covering structure using the covering member 68 to be placed on the existing conventional pipe cover 76. By further covering such an existing conventional pipe cover 76 with a cover member in which a non-woven fabric containing a highly water-absorbent polymer is arranged on the foam surface, it becomes possible to prevent or suppress the dripping of condensed water. In this embodiment, an adhesive layer 63 (the thickness of the layer is not shown) is disposed on the back surface of the portion extending from the foam of the non-woven fabric 3 on the outermost layer of the upper resin foam. Further, a film-shaped release sheet 62 is bonded to the back surface of the adhesive layer 63, and the release sheet 62 can be peeled off and adhered to the resin foam 2. According to the covering member 68 for covering the conventional type pipe cover shown in the figure, it can be applied to the refrigerant pipe covered with the existing conventional type pipe cover, and the dripping of condensed water can be prevented or suppressed. Specifically, the covering member 68 for covering the conventional type pipe cover shown in Fig. 13 has a gap 69. The heat insulation cover member can be opened in a butterfly shape at this portion and can be mounted so as to cover the existing pipe. The non-woven fabric 3 extending from one end of the covering member 68 for covering the conventional type pipe cover 76 is provided with an adhesive layer 63, and can be wound while peeling off and adhering the release sheet. Since a heat insulation cover member for preventing or suppressing the dripping of condensed water is used for this non-woven fabric 3, the same amount of superabsorbent resin fibers (not shown) as in the present invention is contained, so that the effect of preventing or suppressing the dripping of condensed water can be exerted.

[0088] (Application to Duct Covering Member and Covering Structure of Heat Insulation Cover Member) Water vapor may also condense on the outer surface of the metal duct for the heat exchanger having a substantially rectangular cross section, and water droplets may drip along the surface of the duct. In contrast, Fig. 14 shows an aspect in which the heat insulation cover member according to the present invention is applied as a duct covering member 70 to a metal (especially iron) duct 67. Specifically, an adhesive layer or an adhesive layer (not shown) is provided on the side opposite to the non-woven fabric 3 of the resin foam 2, and the heat insulation cover member is adhered to the iron duct 67 as the duct covering member 70 through this adhesive layer. Here, the non-woven fabric 3 contains superabsorbent resin fibers (not shown). At this time, the heat insulation cover member with an adhesive is used as the duct covering member 70. Here, the duct covering member 70 may be wound across the corner portion of the duct 67. However, in this case, since the corner portion cannot be wound with a uniform wall thickness, a sheet cut to a predetermined size corresponding to each side of the outer peripheral surface of the duct may be used as the duct covering member 70 and attached to each outer surface of the duct. By doing so, the heat insulation cover member can cover the duct covering member 70 across the entire outer peripheral surface of the duct. As a result, a duct covering structure in which the duct covering member 70 is attached to the outer peripheral surface of the duct can be obtained. Therefore, it is expected to exhibit the effect of preventing or suppressing the dripping of condensed water.

[0089] (Materials such as examples and comparative examples, test results, and other supplementary notes) Examples of the thermoplastic resin fibers include fibers of PP, PE, PET, or fibers having a core-sheath structure such as PET / PE and PP / PE. In the examples, among these fibers, test results were shown using a non-woven fabric having a core-sheath structure of PET / PE as the base resin, whether the non-woven fabric was single-layer or multi-layer. However, as the base resin, in addition to the core-sheath structure of PET / PE, a core-sheath structure of PP / PE may also be used. Here, the reason for using fibers having a core-sheath structure is that it is desirable to use a high melting point PET or PP for the core part and a low melting point fiber such as PE for the sheath part. Of course, it is also possible to use ordinary fibers that do not have a core-sheath structure such as PP, PE, and PET. However, by using a high melting point material for the core part and a low melting point material for the sheath part, both the strength and the fusibility of the non-woven fabric can be enhanced. That is, whether to use fibers having a core-sheath structure or ordinary fibers may be determined according to the usage situation.

[0090] The product (invention example material) of the present invention is a non-woven fabric applied to a resin foam is complex layer (two layers) in the case of and has a non-woven fabric layer containing at least highly water-absorbent resin fibers. By containing 10% to 80% by mass of highly water-absorbent resin fibers in this non-woven fabric layer and 20% to 90% by mass of thermoplastic resin fibers as the balance, the water retention parameter and the water retention property satisfy predetermined values. As a result, in the vertical pipe condensation water dripping test, The reference example material shows an improvement effect in which the improvement rate of the amount of dew condensation dripping with respect to the conventional example material exceeds 30%. The inventive example material shows an improvement effect in which the improvement rate of the amount of condensed water dripping compared to the conventional example material exceeds 40 %, and In addition, even in the case of the laminated structure, when the first layer that does not contain superabsorbent resin fibers is used as the outer layer, an improvement effect exceeding 50% was recognized. considering this as a threshold value, respectively the amount of condensed water dripping 28.4 g, 23.4 g showed good results below. Such good results were confirmed not only for Bell Oasis (inventive examples material 6 ~10), but also for Lansil (inventive example material 1 1). Also, when the non-woven fabric is laminated (2 layers) (inventive example materials 6 to 11), in the dew condensation water dripping test under severe temperature and humidity conditions using a vertical pipe with a glasses-shaped pipe, compared with the reference example material it was confirmed that good results were shown.

[0091] Also, in the case of a laminated non-woven fabric structure, from the basic performance of the non-woven fabric with a structure in which the first layer containing no superabsorbent resin fiber is arranged on the outer layer and the second layer containing superabsorbent resin fiber is arranged on the inner layer, and the structure in which this structure is inverted up and down with the second layer containing superabsorbent resin fiber arranged on the outer layer and the first layer containing no superabsorbent resin fiber arranged on the inner layer, and the results of the dew condensation prevention or suppression test, the cover member with a laminated structure in which the first layer containing no superabsorbent resin fiber is arranged on the outer layer is superior in the performance of preventing or suppressing the dripping of condensed water. Comparing the laminated product with of the reference example material the single-layer product, it can be seen that the laminated product is of the reference example material superior to the single-layer product in terms of dew condensation prevention or suppression performance. The above-mentioned laminated product and of the reference example material The difference in the condensation prevention or drip suppression performance in the single-layered product is presumably due to the fact that the laminated product, including the upside-down structure, can provide the effect of widely diffusing condensation water by providing the first layer, which is a nonwoven fabric layer made of thermoplastic resin fibers that do not contain superabsorbent resin fibers, in the laminated product, and furthermore, the evaporation effect of condensation water is promoted by placing the first layer as the outer layer. In contrast, when the upside-down second layer is placed as the outer layer, it has a certain degree of effect of diffusing condensation water that penetrates the second layer, which is the outer layer, and reaches the first layer, but the evaporation effect of condensation water when the second layer is formed as the outer layer is weak, so it is considered that the laminated product with the first layer as the outer layer has a better effect of preventing or suppressing dripping of condensation water than the laminated product with the second layer as the outer layer. This can be understood from the fact that the evaporation effect when the first layer is placed on the outer surface as described in paragraph

[0075] is greater than the evaporation effect when the second layer is placed on the outer surface or in the single-layered product. From the above, it can be seen that the balance between the diffusion and evaporation effect of the nonwoven fabric and the water retention effect of the superabsorbent resin fiber is important for preventing or suppressing the dripping of condensation water, and that a thermal insulation cover member in which a nonwoven fabric with the first layer placed on the outer surface is laminated onto a resin foam body is the most effective for preventing or suppressing the dripping of condensation water. na It is considered that.

[0092] Among the inventive example materials, the higher the blending ratio of superabsorbent polymer fiber, the higher the water retention parameter and water retention tended to be, and in the vertical piping condensation water dripping test, the effect of preventing or suppressing dripping of condensation water was observed. Specifically, in the vertical piping condensation water dripping test, it was found that when the blending ratio of BELLOASIS was 10 mass%, the weight was 32.5g, but when the blending ratio increased to 75 mass%, it was reduced to 3.8g. Also, when the blending ratio was 25% or more, it was possible to reduce it to 0.8 to 23.3g, which is less than 24g, in the vertical piping test, and the improvement rate exceeded 50%, so it is desirable for the blending ratio of the layer containing the superabsorbent polymer to be 25% or more. In addition, Fig. 15 shows the time change of the amount of condensed water dripping in the dew condensation water dripping test under the severe environment of temperature 35°C × humidity 90% using spectacle-type piping with a representative example of the test material for the vertical piping. The test results show the change over time of the conventional material 1 and the inventive material 8 (mixing ratio of highly water-absorbent resin Ver Oasis is 40%) shown in Table 2. When comparing the conventional material 1 and the inventive material 8, the conventional material 1 shows a tendency that the dripping of condensed water progresses rapidly when a little over 6 hours have passed, while in the inventive material 8 of the present invention, no dripping of condensed water occurs until 11 hours and then condensed water occurs, but it can be seen that the increasing tendency is also weak. Also, in contrast to this, although not particularly shown in the figure, in the case of horizontal piping, including the inventive material 8 of the present application, reference example material (reference example material 1 to reference example material 5) , in the inventive materials (inventive materials 6 to 11), no dripping of condensed water occurs in any of the materials, but in the conventional material 1, dripping of condensed water occurs even in the case of horizontal piping.

[0093] From the above results, according to the heat-insulating cover member for preventing or suppressing dripping of the present invention, in the piping structure to which this is applied, even when the refrigerant piping such as an air conditioner is a vertical piping instead of a horizontal piping, it can be seen that the dripping of condensed water on the piping surface can be effectively suppressed or prevented. Therefore, according to the present invention, it is possible to suppress the situation where water accumulates around the ceiling space or the indoor vertical piping due to the water droplets dripping from the refrigerant piping, resulting in the generation of mold and bacteria or the corrosion of wood, deteriorating the living environment. It can be understood that, compared with the conventional ones, it is possible to prevent the deterioration of the living environment and maintain the soundness of the house for a longer period.

[0094] In the heat exchange piping covering component according to the present invention, it has an effect of preventing the dripping of condensed water. That is, when using any of the protective members such as a joint covering member that covers the gap between the heat-insulating cover members, an elbow covering member in which the heat-insulating cover member is applied to the bent portion of the heat exchange piping, and a covering member that covers the existing conventional piping cover used by winding it around the existing piping, it is expected to suppress the generation of condensed water or, even if condensed water is generated, prevent or suppress its dripping. Here, it is conceivable to use it for the above-mentioned joint covering member, elbow covering member, covering member for an existing pipe cover, etc. In any of these applications, a structure that basically uses the heat-insulating cover member for preventing or suppressing the dripping of condensed water, in which a non-woven fabric is joined to the surface of the resin foam of the present invention, is utilized. Further, for the gaps of the protective member as a heat mating pipe covering member and for covering the outer peripheries thereof on the existing heat-insulating structure using a foam, an effect equivalent to that of the present invention can be expected. Also, strictly speaking, in the case of the elbow covering member, since the heat-insulating cover member for preventing or suppressing the dripping of the above-mentioned condensed water is used after press molding, there is a part where the apparent plate thickness as the cover member is about 20% thinner, but it has been found that the bubbles are refined in that part and there is no difference in heat insulation performance. From the above, the above-mentioned joint covering member, elbow covering member, and covering member for an existing pipe cover are all considered to have the same dew condensation prevention or dew condensation suppression performance as the heat-insulating cover member for preventing or suppressing the dripping of condensed water, in which a non-woven fabric is joined to the surface of the resin foam of the present invention. Here, as a result of commercializing and launching these heat mating pipe covering members on the market, it has been confirmed that the effect of preventing or suppressing the dripping of condensed water is sufficient.

[0095] Consider the ease of dew condensation of a copper refrigerant pipe and a metal (iron) duct. For example, assuming that the ambient temperature is 23°C under the same conditions and the fluid temperature flowing inside the refrigerant pipe is a constant 5°C under the same conditions and is flowing in a steady state, the fluid temperatures are both constant. Further, since the cross-sectional direction of the duct has the same configuration in which a non-woven fabric having a predetermined thickness containing highly water-absorbent fibers is laminated on the surface side of the foam, it is considered that the copper pipe and the duct will have substantially the same surface temperature with respect to heat transfer in the cross-sectional direction under the condition of using the same foam including the thickness.

[0096] However, in this case, the temperature of the refrigerant flowing through the refrigerant pipe is the same as the temperature of the air flowing through the duct. On the premise that the fluid temperature flowing in the pipe axis direction is constant in the steady state, the temperature of the non-woven fabric surface between the two is equal. On the other hand, the temperature of the refrigerant flowing through the copper refrigerant pipe currently under consideration is around 5°C, and the temperature of the air flowing in the duct is 13 - 17°C. In this case, since the air flowing in the duct is generally higher than the temperature of the refrigerant flowing through the copper pipe, the heat transfer is less in the duct.

[0097] Also, when comparing the thermal conductivity of copper, which is the material of the refrigerant pipe, with that of iron, which is the material of the duct, the thermal conductivity of iron is lower. When the thickness of both is about 1 mm, the thermal resistance of the latter is higher. Therefore, regarding the heat transfer from each fluid, the influence of the air temperature in the duct on the surface temperature of the foam and non-woven fabric coated on the duct surface is smaller than that of the foam and non-woven fabric coated on the copper pipe. As a result, from this perspective as well, the decrease in the non-woven fabric surface temperature is smaller in the duct than in the case of the copper pipe. The structure of coating the duct has less influence on the non-woven fabric surface temperature from the internal fluid than the structure of coating the copper pipe. Therefore, it is considered that the evaluation result of the dew condensation test for the copper refrigerant piping of the present invention does not show that the surface temperatures of the foam and non-woven fabric in the case of the duct are severe, but rather tend to be relaxed. Therefore, regarding the evaluation of dew condensation occurrence and dripping, it is considered possible to directly apply the tendency of the test results of the heat insulation cover member for preventing or suppressing the dripping of the dew condensation water of the present invention.

[0098] Just in case, to confirm this, test material 1 which is a single-layer non-woven fabric (basis weight is 145 g / m 2 with a mixing ratio of SAF of 10%), test material 6 which is a two-layer laminated non-woven fabric (basis weight of the surface layer PET / PE is 18 g / m 2 and the basis weight of the layer containing SAF in the second layer is 30 g / m 2 with a mixing ratio of SAF of 10%) each of with the lowest mixing ratio of SAF as the reference example material test material 1, as the invention example material Using the test material 6, a rectangular duct with a width of 10 cm × a height of 10 cm × a length of 30 cm was fabricated. The entire surface of the duct was covered with a structure coated with the test material by bonding the foam surface side of the test material to the duct with an adhesive so that the non-woven fabric side of the test material was placed on the surface of the duct. After installing this structure so that the air flow in the duct was in the vertical direction, the air temperature in the duct was adjusted to be 13°C ± 1°C, which was the lower limit value, and a dew condensation drip check test was conducted under a severe environment of a temperature of 35°C × a humidity of 90%. As a result, evaluation results equal to or better than those in the case of the copper pipe shown in Table 2 were obtained. As a result, it was confirmed that the duct cover member also had a sufficient dew condensation prevention and suppression effect. At this time, it is clear from Table 1 that the non-woven fabric has a water retention parameter of 0.70 or more that resists the gravity of the non-woven fabric and retains moisture, and satisfies a water retention amount of 7.0 g or more obtained under predetermined conditions.

[0099] Here, although it is described as preventing or suppressing the dripping of condensed water instead of preventing the dripping of condensed water in the present invention, the reason is that it is possible to prevent the dripping of condensed water in the normal use environment, but in the actual construction site, it is not known what kind of severe environment will be encountered, and even if it does not encounter an installation environment corresponding to the severe temperature and humidity conditions such as the dew condensation drip prevention test conducted this time, various temperature and humidity conditions are assumed. Also, in the actual laying environment, even if it is not a severe environment condition, the temperature and humidity conditions vary with time, so there is also a problem that a complete comparison with the installation environment at each individual site cannot always be made. Therefore, in the present application, based on such considerations, in the object and problem of the present application, it is deliberately described as preventing or suppressing the dripping of condensed water instead of preventing the dripping of condensed water. Also, in the severe temperature and humidity environment test using a vertical pipe with a bellows-type pipe using a thermostatic and humidistatic chamber, the cover member containing the high water-absorbing resin fiber at a mixing ratio of 10% or more and 80% or less has a dew condensation generation amount asIt was confirmed that there is an improvement effect of at least 30%, and when the mixing ratio of the superabsorbent resin fiber is 25% or more and 80% or less, there is an improvement effect of 50% or more. From the above, looking at the test results in the present invention, it is clear that the inventive example material can significantly suppress the dripping of condensed water even in a harsh environment at least compared to the conventional example material and the comparative example material, and it is clear that either prevention or suppression of the dripping of condensed water can be achieved even in the actual use environment.

Explanation of Signs

[0100] 1 Refrigerant pipe 11 Pipe 12 Drain pipe 13 Wiring pipe 2 Resin foam 21 Bubbles 22, 23 Pipe storage part 25 Elbow covering member (bend joint) 26 Elbow storage part 27 Resin film 3 Non-woven fabric 31 First layer of non-woven fabric 32 Second layer of non-woven fabric 35 Thermoplastic resin fiber 36 Superabsorbent resin fiber 5 Heat insulation cover member 6 Cavity, flow path 10, 20, 30, 40 Pipe structure 41 Test piece 42 Migration range of water droplets 43 Upward water droplet migration amount 44 Downward water droplet migration amount 51 Container 52 Water 53 Measurement (electronic balance) 62 Release sheet 63 Adhesive layer 65 Joint covering member 66 Joint 67 Metal duct (iron duct) 68 Covering member to cover the existing conventional pipe cover 69 Gap 70 Duct covering member 71 Indoor unit side piping 72 Outdoor unit side piping 73 Intermediate piping 75 Measuring (electronic balance) 76 Conventional piping cover 100 Water retention test material

Claims

1. A heat-insulating cover member for preventing or suppressing the dripping of condensed water, in which a non-woven fabric is disposed on the surface of a resin foam, wherein the resin foam is a polyethylene-based resin foam having closed cells, and the non-woven fabric is fixed to one surface of the resin foam by fusion or adhesion, the non-woven fabric is a laminated non-woven fabric having a laminated structure of a first layer and a second layer, the first layer of the non-woven fabric is composed only of thermoplastic resin fibers, at least a part of the thermoplastic resin fibers are fused or adhered to each other, and it is a transpiration diffusion promoting layer that promotes the transpiration effect due to the evaporation of moisture, the second layer of the non-woven fabric is composed of a non-woven fabric in which a predetermined amount of highly water-absorbent resin fibers that retain water in a gel structure crosslinked with a polymer are mixed with thermoplastic resin fibers, at least a part of the thermoplastic resin fibers are fused or adhered to each other, and it is a water-retaining layer having higher water-retaining property than the first layer, the non-woven fabric of the second layer contains 10% by mass or more and 80% by mass or less of highly water-absorbent resin fibers with respect to the total mass of the non-woven fabric constituting the second layer, and further contains 20% by mass or more and 90% by mass or less of the thermoplastic resin fibers as the balance, the non-woven fabric having the first layer and the second layer has an evaporation amount of 8.88 g or more, the evaporation amount is a value obtained by subtracting the mass at the time of removal from the total mass before the start of the test, the total mass before the test refers to the total mass of a test piece formed by placing a refrigerant pipe having a length of 150 mm and a diameter of 25 mm covered with the heat-insulating cover member on the outer periphery into a container containing 20 g of water, the mass at the time of removal refers to the total mass of the test piece when the test piece is taken out after being held in a thermostatic and humidistatic chamber at 23°C × relative humidity 30% RH for 6 hours, A heat-insulating cover member for preventing or suppressing the dripping of condensed water from a pipe, characterized by the above.

2. The heat-insulating cover member for preventing or suppressing the dripping of condensed water according to Claim 1, wherein the polyethylene-based resin foam contains a flame retardant.

3. A joint covering member capable of being arranged to cover a gap between the heat-insulating cover member and another heat-insulating cover member arranged adjacent to the former in the longitudinal direction of the pipe when the pipe is covered with the heat-insulating cover member for preventing or suppressing dripping of condensed water according to claim 1 or claim 2, wherein the joint covering member has a release paper laminated on an adhesive layer on one surface of a foam, and a non-woven fabric is coated on the other surface of the foam, and the joint covering member is characterized in that by using the bonding surface of the non-woven fabric to the foam as an outer periphery, the adhesive layer is bonded to the outer periphery of the heat-insulating cover member and used for a joint of the cover member, it is possible to prevent or suppress dripping of condensed water.

4. An elbow covering member characterized in that it can be obtained by press-forming a member which can cover a 90° bent portion of a pipe with the heat-insulating cover member for preventing or suppressing dripping of condensed water according to claim 1 or claim 2 so that it becomes a substantially L-shaped after being bent in a shape facing each other with a predetermined size and back to back, and by covering an elbow portion of the 90° bent portion or the vicinity of the 90° bent portion where the pipe is directly bent by 90° with the bonding surface of the non-woven fabric to the foam of the member as an outer surface, it is possible to prevent or suppress dripping of condensed water.

5. A covering member for covering an existing conventional pipe cover, characterized in that a cover member for covering an existing pipe with a polyethylene film laminated on its surface is wound around a heat exchanger pipe in a substantially cylindrical shape so that the center is in the center and both ends face each other with the heat-insulating cover member according to claim 1 or claim 2 for preventing or suppressing dripping of condensed water, and further, the heat-insulating cover member is wound around the outer surface of the covering member so as to cover the outer surface of the covering member with the non-woven fabric surface as the outer surface and both ends face each other, whereby it is possible to prevent or suppress dripping of condensed water.

6. A duct covering member characterized in that it can cover the outer surface of a duct with the heat-insulating cover member for preventing or suppressing dripping of condensed water according to claim 1 or claim 2.

7. In a piping structure including at least one of a horizontal pipe, an inclined pipe, a vertical pipe, and a bent pipe, where the dew condensation prevention or suppression heat insulation cover member according to claim 1 or 2 is coated on the outer periphery of a refrigerant pipe, the dew condensation prevention or suppression heat insulation cover member uses either the surface of the first layer or the second layer of the non-woven fabric of the laminated structure as the outer surface, and each of the heat insulation cover members coats the refrigerant pipe. A piping structure characterized by this.

8. In a piping structure including at least one of a horizontal pipe, an inclined pipe, a vertical pipe, and a bent pipe, where the dew condensation prevention or suppression heat insulation cover member according to claim 1 or 2 is coated on the outer periphery of each of two refrigerant pipes, and the heat insulation cover members are heat-sealed or adhered to each other to form a glasses-shaped cross-section pipe, on the outer periphery of each refrigerant pipe of the piping structure, either the surface of the first layer or the second layer of the non-woven fabric of the laminated structure of the dew condensation prevention or suppression heat insulation cover member is used as the outer surface to coat each of the refrigerant pipes, and the two pipes are integrated into a glasses shape by thermally fusing or adhering the outer surfaces of the non-woven fabrics with the respective refrigerant pipes facing each other. A piping structure characterized by this.

9. One or more refrigerant pipes, a drain pipe, and pipes for wiring and wiring are prepared. In a piping structure including at least one of a horizontal pipe, an inclined pipe, a vertical pipe, and a bent pipe, where one or more refrigerant pipes, a drain pipe, and pipes for wiring and wiring are housed inside the dew condensation prevention or suppression heat insulation cover member according to claim 1 or 2, Using either the surface of the first layer or the second layer of the non-woven fabric of the laminated structure as the outer surface, and surrounding the refrigerant pipe, drain pipe, and pipes for wiring and wiring with the heat insulation cover member so that the outer peripheral surface shape of the dew condensation prevention or suppression heat insulation cover member becomes a substantially cylindrical cross-section shape, and the components installed in the pipe are housed inside the dew condensation prevention or suppression heat insulation cover member. A piping structure for a refrigerant pipe characterized by this.

10. A covering structure for preventing or suppressing dripping of condensed water of a heat exchanger duct by a heat-insulating cover member for preventing or suppressing dripping of condensed water, wherein the heat-insulating cover member for preventing or suppressing dripping of condensed water according to claim 1 or 2 is covered on the entire outer surface of an iron duct for a heat exchanger having a substantially rectangular cross-section so as to cover the outer periphery of the entire outer surface.

11. A method of using a heat-insulating cover member for preventing or suppressing dripping of condensed water for a heat exchange pipe covering member, wherein the heat-insulating cover member for preventing or suppressing dripping of condensed water according to claim 1 or 2 is used as a covering member for a joint covering member, an elbow covering member, a cheese covering member, or an existing conventional pipe cover used in a gap between heat-insulating cover members.

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