Construction method for forming urethane thermal insulation material, building structure, and thermal insulation structure

Abstract

To provide a technology that resolves at least a part of the problems, such as voids or uplift in a urethane thermal insulation material and reduced moisture permeability of a moisture-permeable waterproof sheet.SOLUTION: The construction method for forming a urethane thermal insulation material 11 comprises spraying a urethane raw material onto a moisture-permeable waterproof sheet 20 for building, whose sprayed surface 20S is composed of a porous resin film layer 23, at a construction site.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a construction method for forming a urethane insulation material, a building structure, and an insulated structure. [Background technology]

[0002] Breathable waterproof sheets are widely used in buildings to prevent rainwater from entering from the outside while allowing moisture inside to escape. A general-purpose breathable waterproof sheet consists of a breathable waterproof film layer on the outdoor side and a reinforcing layer on the indoor side, with the reinforcing layer generally made of polyester nonwoven fabric.

[0003] Patent Document 1 discloses a heat insulating structure in which a rigid urethane foam insulating material is laminated on the surface of a facing material. It also states that a sheet material in which a synthetic resin microporous film is coated or laminated on one side of a nonwoven fabric can be used as the facing material.

[0004] Patent Document 2 discloses a thermal insulation structure for a building that has an insulating layer formed by spraying a rigid polyurethane foam concentrate onto a soft facing from the indoor side and allowing it to foam and harden. As a specific example, the document describes a test specimen that uses two layers of moisture-permeable and waterproof sheet material laminated together without bonding them together as the soft facing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-57398 [Patent Document 2] JP 2014-148800 A Summary of the Invention [Problem to be solved by the invention]

[0006] The configuration of the surface onto which the urethane raw material is sprayed is not specified in Patent Documents 1 and 2. Generally, in a moisture-permeable waterproof sheet comprising a nonwoven fabric and a porous resin film layer, the sprayed surface is made of nonwoven fabric.

[0007] Spraying urethane raw materials onto the nonwoven fabric side of a moisture-permeable waterproof sheet can cause voids to form in the urethane insulation or cause the urethane insulation to rise to the bottom. Spraying urethane raw materials onto the nonwoven fabric side of a moisture-permeable waterproof sheet can also reduce the moisture permeability of the sheet. The present disclosure is intended to solve at least part of the above problems, and can be realized in the following forms. [Means for solving the problem]

[0008] This is a construction method in which urethane raw materials are sprayed onto a breathable waterproof sheet for construction, the spray surface of which is made of a porous resin film layer, at the construction site to form urethane insulation. [Effects of the Invention]

[0009] The present disclosure can solve at least some of the above problems. For example, it can prevent voids and bottom-up in urethane insulation. It can also prevent a decrease in the moisture permeability of moisture-permeable waterproof sheets. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view schematically showing a heat insulating structure according to an embodiment. [Figure 2] FIG. 2 is an enlarged cross-sectional view showing a part of FIG. 1. [Figure 3] FIG. 10 is an enlarged cross-sectional view showing a part of a thermal insulation structure according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure will be described in detail below. In this specification, when a numerical range is indicated using "-", it is intended to include both the lower limit and the upper limit unless otherwise specified. For example, the expression "10-20" includes both the lower limit "10" and the upper limit "20". In other words, "10-20" has the same meaning as "10 or more and 20 or less". In addition, in this specification, the upper limit and lower limit of each numerical range can be combined in any way.

[0012] 1. Construction method for forming urethane insulation material 11 In the construction method of this embodiment, a urethane insulating material 11 is formed by spraying a urethane raw material onto a moisture-permeable waterproof sheet for building 20 having a spray surface 20S formed of a porous resin film layer 23 at a construction site.

[0013] Conventionally, when urethane raw materials are sprayed on a construction site to form urethane insulation material 11, structural facing materials such as plywood, particle board, and excelsior cement board are used. A moisture-permeable waterproof sheet is placed on the outdoor side of the structural facing material, and the urethane raw materials are sprayed on the indoor side of the structural facing material to form the urethane insulation material. The construction methods generally used for wooden detached houses are the post-and-beam method and the framework method. In the post-and-beam method, the load is primarily supported by pillars, so the mechanical contribution of the structural surface material is considered to be low. The inventors of the present application came up with the idea of ​​omitting the structural surface material and attempted a construction method in which urethane raw material is directly sprayed onto a moisture-permeable waterproof sheet. However, they found that simply spraying the urethane raw material directly onto a conventional moisture-permeable waterproof sheet creates new problems, such as voids and lifting of the urethane insulation material, and a decrease in the moisture permeability of the moisture-permeable waterproof sheet. After extensive research, the inventors of the present application have developed the technology of the present disclosure, in which a urethane raw material is directly sprayed onto a moisture-permeable waterproof sheet. Note that the technology of the present disclosure is not limited by the above-mentioned development history, and is also useful for, for example, construction methods other than the frame construction method for wooden detached houses, and for the construction of buildings other than wooden detached houses.

[0014] (1) Breathable waterproof sheet for construction 20,120 The spray surface 20S of the moisture-permeable waterproof sheet for architecture 20, 120 is formed of a porous resin film layer 23. There are no particular limitations on other configurations of the moisture-permeable waterproof sheet for architecture 20, 120. The moisture-permeable waterproof sheet for architecture 20, 120 is preferably a moisture-permeable waterproof sheet specified in JIS A6111:2016.

[0015] 1, the moisture-permeable waterproof sheet for architecture 20 comprises a moisture-permeable waterproof laminate having a reinforcing layer 21 and a porous resin film layer 23. In each figure, the arrow OUT indicates the outdoor side, and the arrow IN indicates the indoor side.

[0016] There are no particular limitations on the reinforcing layer 21. The reinforcing layer 21 is, for example, one or more layers selected from the group consisting of nonwoven fabric, woven fabric, metal wire, and metal mesh. The nonwoven fabric or woven fabric can be made of one or more fibers selected from the group consisting of polyethylene fiber, polypropylene fiber, polyethylene terephthalate (PET) fiber, pulp fiber, and glass fiber.

[0017] The porous resin film layer 23 is not particularly limited. The porous resin film layer 23 is composed of a moisture-permeable, waterproof, i.e., impermeable, resin film. Specifically, the resin film is preferably a polyolefin film, more preferably a polyethylene film or a polypropylene film. The resin film has numerous micropores. The micropores are appropriately set to achieve the moisture-permeable, waterproof performance specified in JIS A6111:2016.

[0018] The "moisture-permeable waterproof sheet for architecture" may further include layers other than the reinforcing layer 21 and the porous resin film layer 23. For example, the "moisture-permeable waterproof sheet for architecture" may include a heat-shielding layer (not shown) on the outdoor side. The heat-shielding layer may be formed, for example, of a metal vapor deposition film, or may also be formed of a coating of metal fine particles, mica powder, or the like.

[0019] The "moisture-permeable waterproof sheet for architecture" may have a porous resin film layer 25 on the outdoor side, like the moisture-permeable waterproof sheet for architecture 120 in FIG. 3. The moisture-permeable waterproof sheet for architecture 120 has a porous resin film layer 23, a reinforcing layer 21, and a porous resin film layer 25 laminated in this order from the indoor side. With this configuration, the porous resin film layer 25 on the outdoor side can suitably prevent water and the like from penetrating into the reinforcing layer 21 from the outdoor side. The porous resin film layer 25 can have the same configuration as the porous resin film layer 23. The micropores of the porous resin film layer 25 can also have the same configuration as the micropores of the porous resin film layer 23.

[0020] The water vapor transmission resistance (vapor permeability resistance) of the architectural breathable waterproof sheet 20,120 is 0.19m when measured in accordance with JIS A 6111:2016. 2 ·s·Pa / μg(0.00019m 2 ·s·Pa / ng) or less is preferable, and 0.13m 2 ·s·Pa / μg(0.00013m 2 The moisture permeability (moisture permeability) of the moisture permeable waterproof sheet for construction 20, 120 is preferably 0.00200 m / s·s·Pa / ng or less when measured in accordance with JIS K7225:2018 Method A. 2 ·s·Pa / ng or less is preferable, and 0.00150m 2 ·s·Pa / ng or less is more preferable, and 0.00120m 2 ·s·Pa / ng or less is even more preferable. There is no particular restriction on the lower limit of the water vapor transmission resistance (moisture transmission resistance) of the moisture-permeable waterproof sheet for construction 20.

[0021] (2) Urethane insulation 11 The urethane insulation material 11 is not particularly limited, as long as it is formed by spraying urethane raw materials onto the above-mentioned moisture-permeable waterproof sheet for construction 20 at the construction site. The urethane insulation material 11 is preferably a sprayed rigid urethane foam as specified in JIS A9526:2015. Among the sprayed rigid urethane foams specified in JIS A9526:2015, the technology of the present disclosure is particularly effective with sprayed rigid urethane foams obtained from raw materials classified as Class A3, which is a low-density product, and is therefore more preferred.

[0022] The urethane raw material is not particularly limited. The urethane raw material preferably contains at least a polyol, a foaming agent, and an isocyanate. From the viewpoint of ease of on-site foaming, the urethane raw material is preferably a two-component raw material composed of a polyol composition (liquid A) containing a polyol and a foaming agent, and an isocyanate composition (liquid B) containing an isocyanate. The polyol is not particularly limited, and the polyol may be one or more selected from polyether polyols and polyester polyols. The polyol composition (liquid A) may contain, in addition to the polyol and the blowing agent, a foam stabilizer, a curing catalyst, a surfactant, and a flame retardant, and may also contain various dyes, pigments, and fillers depending on the application. The blowing agent is not particularly limited. The blowing agent may be one or more selected from water, hydrofluorocarbons, and hydrofluoroolefins. Among these, water is preferred as the blowing agent. The isocyanate is not particularly limited. The isocyanate may be one or more selected from aromatic isocyanates and aliphatic isocyanates. Examples of aromatic isocyanates include diphenylmethane diisocyanate and tolylene diisocyanate. Examples of aliphatic isocyanates include hexamethylene diisocyanate. The isocyanate may be a prepolymerized isocyanate, or any of various other modified isocyanates.

[0023] The physical properties of the urethane heat insulating material 11 are not particularly limited. The thermal conductivity of the urethane heat insulating material 11 is preferably 0.040 W / (m·K) or less when measured according to JIS A 1412-1 or JIS A 1412-2. The lower limit of the thermal conductivity is usually 0.018 W / (m·K) or more. The density of the urethane heat insulating material 11 is 5 kg / m 3 More than 25kg / m 3 Less than 6.5 kg / m is preferable. 3 More than 20kg / m 3 Less than 8kg / m is more preferable. 3 More than 15kg / m 3 More preferably, 13.5 kg / m 3 Below 12kg / m 3 It may be the following: The flammability of the urethane heat insulating material 11 is preferably such that, when measured according to JIS A 9511, 6.13, measurement method B, the burning time is within 120 seconds and the burning length is 60 mm or less. The urethane insulating material 11 preferably has an open-cell structure.

[0024] (3) Example of construction method An example of an installation method will be described with reference to Figure 1. In this installation method, the porous resin film layer 23 of the moisture-permeable waterproof sheet for architecture 20 is attached to a framework structure 15, 15 with the layer 23 facing the indoor side. The framework structure 15, 15 is, for example, a pillar or stud in the wall of a building, or a beam in the roof of a building. In this case, it is preferable to attach the moisture-permeable waterproof sheet for architecture 20 to the framework structure 15, 15 without sagging. In this way, sagging of the moisture-permeable waterproof sheet for architecture 20 toward the outdoor side due to the pressure when the urethane raw material is sprayed onto the spraying surface 20S can be suitably prevented.

[0025] As shown in Figure 1, when the vapor-permeable waterproof architectural sheet 20 is attached to the outdoor side of frame structures 15, 15, the surface of the porous resin film layer 23 between the frame structures 15, 15 that can be seen from the indoor side is the sprayed surface 20S of the urethane raw material. An exterior wall material or roof material (hereinafter also referred to as an exterior wall material, etc.) is installed on the outdoor side of the vapor-permeable waterproof architectural sheet 20 via furring strips (not shown). A breathable layer is formed between the vapor-permeable waterproof architectural sheet 20 and the exterior wall material, etc. The furring strips, exterior wall material, etc. may be installed before or after the urethane raw material is sprayed onto the vapor-permeable waterproof architectural sheet 20.

[0026] This construction method forms urethane insulation 11 by spraying urethane raw materials onto a moisture-permeable waterproof sheet for construction 20, whose spraying surface 20S is composed of a porous resin film layer 23, at the construction site. In other words, this construction method employs a technique known as on-site foaming, in which the urethane raw materials are directly sprayed. Compared to techniques using inorganic fibers such as glass wool or rock wool or foamed resin boards such as extruded polystyrene foam or phenolic foam, this technique offers the advantage of superior adhesion and airtightness of the insulation and is less likely to cause structural insulation defects. Therefore, this construction method is particularly suitable for forming insulation for building walls and attics.

[0027] To prevent the vapor-permeable waterproof architectural sheet 20 from sagging outdoors, a support member may be used to support the vapor-permeable waterproof architectural sheet 20 from the side opposite the sprayed surface 20S when the urethane raw material is sprayed. A suitable support member is, for example, a board such as plywood. The support member can be removed and reused after the urethane raw material has foamed and hardened. To prevent the vapor-permeable waterproof architectural sheet 20 from sagging outdoors, furring strips may be used to support the vapor-permeable waterproof architectural sheet 20 from the side opposite the sprayed surface 20S. For example, furring strips may be installed in areas other than the outdoor-facing areas of the frame structures 15, 15, and the vapor-permeable waterproof architectural sheet 20 may be supported by the furring strips instead of conventional structural facing materials.

[0028] Furthermore, from the viewpoint of preventing the moisture-permeable waterproof sheet for architecture 20 from sagging toward the outdoors, the urethane insulating material 11 may be formed by spraying the urethane raw material in multiple passes to laminate urethane foam layers. Specifically, the urethane raw material may be sprayed onto the spraying surface 20S of the moisture-permeable waterproof sheet for architecture 20 to form a first urethane foam layer, and then the urethane raw material may be sprayed onto the urethane foam layer to form second and subsequent urethane foam layers, thereby forming the urethane insulating material 11. In this way, by reducing the thickness of the sprayed layer each time, the spray pressure applied to the moisture-permeable waterproof sheet for architecture 20 during each spraying pass can be reduced. The urethane raw material may be sprayed two times, or three or more times.

[0029] (4) Effects of this embodiment In the moisture-permeable waterproof sheet for architecture 20 of this embodiment, the spray surface 20S is composed of a porous resin film layer 23. According to this embodiment, it is possible to prevent voids and bottom lift of the urethane insulation material 11. Furthermore, according to this embodiment, when the spray surface 20S of the moisture-permeable waterproof sheet for architecture 20 is composed of a porous resin film layer 23, it is possible to prevent a decrease in moisture permeability. The reason for this is not clear, but is presumed to be as follows. Note that the present disclosure should not be interpreted in a limited manner based on this presumed reason.

[0030] If the spray surface 20S were configured with a highly breathable layer such as nonwoven fabric rather than the porous resin film layer 23, it is believed that the foaming gas generated when the urethane raw material foams would pass through the highly breathable layer and concentrate in areas with weak adhesive strength, causing voids or a rise in the bottom in those areas. On the other hand, the porous resin film layer 23 is breathable in the thickness direction but not in the direction perpendicular to the thickness direction, and it is presumed that this would prevent voids and a rise in the bottom due to the concentration of foaming gas.

[0031] Furthermore, if the spray surface 20S is configured with a layer such as nonwoven fabric into which the urethane raw material permeates, rather than the porous resin film layer 23, it is thought that the urethane raw material that has permeated into the layer hardens and reduces the moisture permeability. On the other hand, the porous resin film layer 23, which has moisture permeability and waterproofing, has sufficiently small pore diameters for the micropores, so it is thought that the urethane raw material does not easily permeate into the layer, thereby suppressing the reduction in moisture permeability.

[0032] 2. Architectural structure The architectural structure of this embodiment is a wall or roof of a building formed by the above-mentioned construction method. Because the architectural structure is formed by the above-mentioned construction method, voids and rising of the urethane insulation material 11 are reduced, and moisture permeability is suitably ensured. Therefore, an architectural structure with excellent insulation performance and low susceptibility to condensation can be realized.

[0033] 3. Thermal insulation structure 10,110 As shown in Figures 1 and 2, the thermal insulation structure 10 of this embodiment comprises a moisture-permeable waterproof sheet for construction 20 whose spray surface 20S is composed of a porous resin film layer 23, and a urethane insulation material 11 formed by spraying a urethane raw material onto the moisture-permeable waterproof sheet for construction 20. As shown in Figure 3, the modified thermal insulation structure 110 comprises a moisture-permeable waterproof sheet for construction 120 whose spraying surface 20S is composed of a porous resin film layer 23, and a urethane insulation material 11 formed by spraying a urethane raw material onto the moisture-permeable waterproof sheet for construction 120.

[0034] The thermal insulation structures 10, 110 of this embodiment can be suitably manufactured by the above-mentioned construction method for forming the urethane insulation material 11. In the explanation of the thermal insulation structure 10, the explanation of the architectural moisture-permeable waterproof sheets 20, 120 is the same as the explanation of "(1) Architectural moisture-permeable waterproof sheets 20, 120" in "1. Construction method for forming the urethane insulation material 11". The explanation of the urethane insulation material 11 is the same as the explanation of "(2) Urethane insulation material 11" in "1. Construction method for forming the urethane insulation material 11".

[0035] The thermal insulation structures 10, 110 have reduced voids and raised bottoms in the urethane insulation material 11 and also ensure good moisture permeability, thereby realizing thermal insulation structures 10, 110 that are excellent in thermal insulation performance and less susceptible to condensation. [Example]

[0036] The present disclosure will be specifically described below with reference to examples and comparative examples, but the present disclosure is not limited thereto.

[0037] 1. Fabrication of the Heat Insulation Structure The heat insulating structures of Examples 1 to 3 and Comparative Examples 1 to 3 were produced using the moisture-permeable waterproof sheets 1 to 5 shown in Tables 1 and 2. Details of the moisture-permeable waterproof sheets 1 to 5 are as follows. Breathable waterproof sheet 1: Laminated sheet of porous polyolefin film layer and polyethylene terephthalate (PET) nonwoven fabric layer Breathable waterproof sheet 2: Warif TM Laminated sheet of a porous polyolefin film layer reinforced with polyethylene terephthalate (PET) nonwoven fabric layer Breathable waterproof sheet 3: A laminated sheet consisting of a porous polyolefin film layer, a polyethylene terephthalate (PET) nonwoven fabric layer, and a porous polyolefin film layer, in that order. Breathable waterproof sheet 4: Polypropylene (PP) compressed paper layer and porous polyolefin film layer laminated sheet Breathable waterproof sheet 5: Polyethylene terephthalate (PET) nonwoven fabric layer and porous polyolefin film layer laminated sheet

[0038] A wooden frame measuring 900mm in length and 900mm in width was prepared. Moisture-permeable waterproof sheets 1 to 5 were stretched over a wooden frame so that the layer described as the "layer on the indoor side" in Tables 1 and 2 would be the sprayed surface. That is, for moisture-permeable waterproof sheets 1 to 5, the layer described as the "layer on the indoor side" in Tables 1 and 2 would constitute the sprayed surface.

[0039] The following urethane raw materials were sprayed onto the spraying surfaces of the moisture-permeable waterproof sheets 1 to 5. The spraying machine used was an FS-2000 (manufactured by BASF INOAC Polyurethanes Co., Ltd.). Urethane raw material: FOAMLITE SL-100, manufactured by BASF INOAC Polyurethanes Co., Ltd., JIS A9526:2015 A-3, density 11 kg / m 3 , cream time 7 seconds In this manner, the urethane heat insulating material was formed, and the heat insulating structures of the examples and comparative examples were fabricated.

[0040] [Table 1]

[0041] [Table 2]

[0042] 2. Evaluation Water vapor transmission resistance of breathable waterproof sheet 1 - breathable waterproof sheet 3 (vapor transmission resistance, m 2 The water vapor permeability resistance (m s Pa / ng) of the moisture-permeable waterproof sheet 1 to the moisture-permeable waterproof sheet 5 was measured in accordance with JIS A6111:2016. 2 ·s·Pa / ng) was measured in accordance with JIS K7225:2018 Method A. The results are shown in the "Moisture permeability resistance" and "Sheet only" columns in Tables 1 and 2.

[0043] Two hours after spraying the urethane raw material, the moisture-permeable waterproof sheets 1 to 5 were peeled off from the heat insulating structures of each Example and Comparative Example. The water vapor transmission resistance (moisture transmission resistance, m 2 ·s·Pa / ng) was measured in accordance with JIS K7225:2018 Method A. The results are shown in the "Moisture permeation resistance" and "After peeling" columns in Tables 1 and 2.

[0044] After peeling off the moisture-permeable waterproof sheets 1 to 5, the urethane insulation was visually inspected and the voids were evaluated according to the following criteria. Note that large voids caused by the bottom of the urethane insulation rising up were also included in the void area. "Pass": When the urethane insulation is viewed from the exterior side, the total area of ​​voids is less than 10% of the total area of ​​the exterior surface. "Fail": When the urethane insulation is viewed from the outside, the total area of ​​voids is 10% or more of the total area of ​​the outside surface.

[0045] 3.Results The evaluation results are shown in Tables 1 and 2. Examples 1 to 3, in which the sprayed surface was composed of a porous resin film layer, passed the evaluation of voids. In contrast, Comparative Examples 1 to 3, in which the sprayed surface was composed of a layer other than a porous resin film layer, failed the evaluation of voids. This result suggests that when the sprayed surface is composed of a porous resin film layer, voids and bottom lift in the urethane insulation can be suppressed.

[0046] Furthermore, in Examples 1 to 3, in which the sprayed surface was composed of a porous resin film layer, the moisture permeation resistance "after peeling" was about 3 to 4 times that of the "sheet alone." In contrast, in Comparative Examples 1 to 3, in which the sprayed surface was composed of a layer other than a porous resin film layer, the moisture permeation resistance "after peeling" was about 11 to 30 times that of the "sheet alone." This result suggests that when the sprayed surface is composed of a porous resin film layer, the decrease in moisture permeability can be suppressed.

[0047] According to the above examples, at least some of the problems related to voids and bottom lift in the urethane insulation and reduced moisture permeability of the moisture-permeable waterproof sheet could be solved.

[0048] The present disclosure is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the present disclosure. [Explanation of symbols]

[0049] 10,110...Insulated structure 11...Urethane insulation 15...Shaft structure 20,120...Breathable waterproof sheet for construction 21...Reinforcement layer 23...Porous resin film layer 25...Porous resin film layer

Claims

1. This construction method involves spraying urethane raw materials onto a breathable waterproof architectural sheet, the spray surface of which is made of a porous resin film layer, at the construction site to form urethane insulation.

2. An architectural structure which is a wall or roof of a building formed by the construction method according to claim 1.

3. A breathable waterproof sheet for construction, the spray surface of which is made of a porous resin film layer; A thermal insulation structure comprising a urethane insulation material formed by spraying a urethane raw material onto the moisture-permeable waterproof sheet for construction.

Images