Polyurethane foam and method for producing the same

Abstract

To provide a polyurethane foam which is excellent in heat insulation property even when being thinned, and is excellent in adhesion to a surface of a wooden skeleton, and a method for producing the same.SOLUTION: A polyurethane foam joined to a surface of a wooden skeleton is obtained by supplying, onto the surface of the wooden skeleton, a composition for a polyurethane foam prepared using a polyol composition containing a polyol including an aromatic polyester polyol, a catalyst containing a trimerization catalyst and a resinification metal catalyst, and a foaming agent containing a halogenated olefin, and a polyisocyanate composition containing a polyisocyanate, and by foaming and curing the composition for polyurethane foam on the surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a polyurethane foam having excellent heat insulating properties and formed on the surface of a wooden frame, and a method for producing the same. [Background technology]

[0002] Conventionally, in detached houses, apartments, public facilities, warehouses, and the like, insulating materials made of resin foams have been installed on the surfaces of wooden walls, pillars, ceilings, and roofs, as well as on the underfloor surface facing the crawl space (hereinafter simply referred to as "floor"), from the viewpoint of heat retention and condensation prevention. Known examples of resin foams include polyurethane foam and phenolic foam. Of these, polyurethane foam is widely used due to its excellent soundproofing properties.

[0003] For example, when a heat insulating layer (heat insulating material) made of polyurethane foam is formed on the surface of a substrate, a method is generally used in which a polyol composition (premix liquid) containing a polyol, a blowing agent, and, as necessary, various auxiliaries such as a catalyst, a foam stabilizer, and a flame retardant, and a polyisocyanate composition containing a polyisocyanate are mixed together, and the resulting mixed liquid, i.e., a polyurethane foam composition, is applied to the surface of the substrate, and the polyurethane foam composition is foamed and cured in the formed coating film.

[0004] The following techniques are known for producing polyurethane foam for thermal insulation.

[0005] Patent Document 1 discloses a spray-on thermal insulation material for construction that has one or more layered, locally high-density regions therein that are denser than other regions, and describes that this spray-on thermal insulation material for construction is preferably made of a polyurethane foam formed from a urethane resin composition that contains a polyol compound, a polyisocyanate compound, a flame retardant, a catalyst, and a blowing agent. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-42289 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a polyurethane foam which has excellent heat insulating properties even when made thin and has excellent adhesion to the surface of a wooden frame, and a method for producing the same. [Means for solving the problem]

[0008] The present invention is presented below. [1] A polyurethane foam obtained by applying a polyurethane foam composition containing a polyol composition including a polyol, a catalyst, and a blowing agent, and a polyisocyanate composition including a polyisocyanate, to the surface of a wooden skeleton, foaming and curing the polyurethane foam composition on the surface, and bonding the polyurethane foam to the surface of the wooden skeleton, The polyol includes an aromatic polyester polyol, The catalyst includes a trimerization catalyst and a resinification metal catalyst; The blowing agent is a polyurethane foam containing a halogenated olefin bonded to the surface of a wooden framework. [2] Density: 25 to 200 kg / m 3 The polyurethane foam according to [1] above, [3] The polyurethane foam according to [1] above, which has a laminated structure consisting of a first layer and a second layer of the same composition from the side of the wooden frame. [4] The polyurethane foam according to [1] above, wherein the aromatic polyester polyol has an aromatic moiety content of 15% or more. [5] The polyurethane foam according to [1], wherein the aromatic polyester polyol contains a phthalic acid-based polyester polyol. [6] The phthalic acid-based polyester polyol includes a first polyester polyol formed from o-phthalic acid or its anhydride and a diol, and a second polyester polyol formed from terephthalic acid and a diol, The polyurethane foam according to [5] above, wherein the proportion of the total amount of the first polyester polyol and the second polyester polyol relative to the total amount of the aromatic polyester polyol is 80 mass % or more. [7] The polyurethane foam according to [1], wherein the polyol further comprises an autocatalytic polyol. [8] The polyurethane foam according to the above [1], wherein the polyurethane foam composition further contains a phosphate ester. [9] The polyurethane foam according to [1] above, wherein the polyurethane foam composition further contains water.

[10] The polyurethane foam according to [1], wherein the wooden structure is a wall, a pillar, a ceiling, a roof, or a floor.

[11] The polyurethane foam according to [1] above, which has a thermal conductivity of 0.021 W / mK or less after storage at 60°C for 28 days.

[12] The polyurethane foam according to [1] above, which has a thermal conductivity of 0.021 W / mK or less after storage at 70°C for 175 days.

[13] A method for producing the polyurethane foam according to the above [1], The method for producing a polyurethane foam on the surface of the wooden skeleton comprises spraying the polyurethane foam composition onto the surface of the wooden skeleton, and foaming and curing the composition to form a polyurethane foam.

[14] The method for producing a polyurethane foam according to

[13] above, wherein the spraying, foaming, and curing of the polyurethane foam composition are repeated at least twice to form a laminate.

[15] The method for producing a polyurethane foam according to the above

[13] , wherein the initial thermal conductivity of the obtained polyurethane foam is 0.019 W / mK or less. [Effects of the Invention]

[0009] The polyurethane foam of the present invention has excellent heat insulating properties and excellent adhesion to the surface of a wooden frame even when made thin, and is therefore suitable as a heat insulating material for wooden walls, columns, ceilings, roofs, or floors in detached houses, apartments, public facilities, warehouses, etc. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a bonded body (laminated structure) containing the polyurethane foam of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described below. The matters set forth herein are for illustrative purposes and are intended to exemplify embodiments of the present invention, and are set forth in order to provide what is believed to be the most effective and easily understandable explanation of the principles and conceptual features of the present invention. In this respect, it is not intended to show structural details of the present invention beyond the extent necessary for a fundamental understanding of the present invention, but rather to clarify to those skilled in the art how some aspects of the present invention can be actually embodied.

[0012] The polyurethane foam of the present invention is produced by applying a polyurethane foam composition having a specific composition to the surface of a wooden skeleton, foaming and curing the resulting coating film on the surface, and bonding it to the surface of the wooden skeleton. Figure 1 is a schematic diagram showing an example of a bonded structure, and is a cross-sectional view showing a bonded structure 1 in which a polyurethane foam 3 is bonded to a wooden skeleton 2.

[0013] The wooden structure according to the present invention is an article obtained by using wood products (bars, boards, etc.) made by cutting and processing wood, wood boards (fiberboards, particle boards, or wood powder moldings), artificial wood, recycled wood, etc., and is preferably a wall, a pillar (which may be solid, hollow, or tubular), a ceiling, a roof, or a floor.

[0014] The polyurethane foam composition according to the present invention is prepared using a polyol composition containing a polyol including an aromatic polyester polyol, a catalyst including a trimerization catalyst and a resinified metal catalyst, and a blowing agent including a halogenated olefin, and a polyisocyanate composition including a polyisocyanate.

[0015] The polyol constituting the polyol composition according to the present invention includes an aromatic polyester polyol, and may contain other polyols (described later) as necessary.

[0016] From the viewpoint of the heat insulating properties of the resulting polyurethane foam, the aromatic polyester polyol preferably contains an aromatic compound having an aromatic moiety content (hereinafter also referred to as "aromatic concentration"), i.e., a mass ratio of aromatic rings constituting the aromatic polyester polyol, of 15 mass% or more. The aromatic concentration in such an aromatic compound is more preferably 15 to 35 mass%, and even more preferably 18 to 30 mass%. The aromatic polyester polyol may also contain an aromatic polyester polyol having a mass ratio of aromatic rings of less than 15 mass%.

[0017] The aromatic polyester polyol preferably contains a phthalic acid-based polyester polyol, which is a condensation reaction product of phthalic acid, terephthalic acid, isophthalic acid, or anhydride thereof with a diol. In the present invention, the phthalic acid-based polyester polyol preferably contains a first polyester polyol formed from o-phthalic acid or anhydride thereof with a diol, and a second polyester polyol formed from terephthalic acid and a diol.

[0018] The first polyester polyol is a polyester polyol obtained using o-phthalic acid or its anhydride and a diol. The first polyester polyol contained in the polyol composition may be one type or two or more types. The second polyester polyol is a polyester polyol obtained using terephthalic acid and a diol. The second polyester polyol contained in the polyol composition may be one type only, or two or more types.

[0019] The diol used to form the first polyester polyol and the second polyester polyol may be any of an aliphatic diol, an alicyclic diol, and an aromatic diol, but is preferably an aliphatic diol. The diol used to form the first polyester polyol and the diol used to form the second polyester polyol may be the same or different.

[0020] The aliphatic diol may be either linear or branched. Examples of linear diols include ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,8-octanediol. Examples of branched diols include propylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 2,2-diethyl-1,3-propanediol.

[0021] The content of aromatic moieties in the first polyester polyol (hereinafter also referred to as "aromatic concentration"), i.e., the mass ratio of aromatic rings constituting the first polyester polyol, is preferably 15 mass% or more, more preferably 15 to 35 mass%, and even more preferably 18 to 30 mass%. The content of aromatic moieties (aromatic concentration) in the second polyester polyol is preferably 15% by mass or more, more preferably 15 to 35% by mass, and even more preferably 18 to 30% by mass.

[0022] In the present invention, from the viewpoint of the heat insulating properties of the resulting polyurethane foam, the content ratios of the first polyester polyol and the second polyester polyol, when their total is taken as 100% by mass, are preferably 20 to 50% by mass and 50 to 80% by mass, more preferably 30 to 50% by mass and 50 to 70% by mass, and even more preferably 35 to 48% by mass and 52 to 65% by mass, respectively.

[0023] In the present invention, the proportion of the total amount of the first polyester polyol and the second polyester polyol relative to the total amount of aromatic polyester polyol is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more.

[0024] The ratio of the total content of the first polyester polyol and the second polyester polyol to the total amount of polyols constituting the polyol composition according to the present invention is preferably 70 to 100 mass%, more preferably 75 to 98 mass%, and even more preferably 80 to 95 mass%.

[0025] The aromatic polyester polyol may include an aromatic polyester polyol other than a phthalic acid-based polyester polyol.

[0026] As described above, the polyol according to the present invention may contain polyols other than the aromatic polyester polyol. Examples of other polyols include polyhydric alcohols, polyhydric phenols, natural fat-and-oil polyols (such as castor oil), polyether polyols (such as glycerin-based polyether polyols, aromatic polyether polyols, Mannich-based polyether polyols, sucrose-based polyether polyols, and sorbitol-based polyether polyols), polyether ester polyols, aliphatic polyester polyols, polydiene polyols, ethylenediamine-based polyether polyols, toluenediamine-based polyether polyols, and tolylenediamine-based polyether polyols. Among these, ethylenediamine-based polyether polyols are preferred. The polyol composition may contain only one or more other polyols.

[0027] The content of the other polyols relative to the total amount of polyols constituting the polyol composition according to the present invention is preferably 0 to 30% by mass, more preferably 5 to 25% by mass, and even more preferably 10 to 20% by mass.

[0028] The ethylenediamine-based polyether polyols, Mannich-based polyether polyols, and toluenediamine-based polyether polyols are "autocatalytic polyols" that have urethane reactivity and also act as catalysts to promote the formation of urethane bonds. From the viewpoint of physical strength and adhesion to wooden frameworks, it is preferable that the other polyols contained are only autocatalytic polyols. Among the autocatalytic polyols, ethylenediamine-based polyether polyols are more preferred.

[0029] The ethylenediamine-based polyether polyol is preferably an alkylene oxide adduct of ethylenediamine, and examples of the alkylene oxide include ethylene oxide, propylene oxide, and butylene oxide. The alkylene oxide may be one or more of these. From the viewpoints of the physical properties of the rigid foam and the cost of the raw material, propylene oxide is preferred as the alkylene oxide. The hydroxyl value of the ethylenediamine-based polyether polyol is preferably 400 mgKOH / g or more from the viewpoint of the mechanical strength of the resulting foam.

[0030] The catalysts constituting the polyol composition according to the present invention include a trimerization catalyst and a resinified metal catalyst. The trimerization catalyst is an isocyanuration catalyst that promotes the formation of isocyanurate rings, and the resinified metal catalyst is a urethanization catalyst that promotes the formation of urethane bonds.

[0031] Examples of the trimerization catalyst include quaternary ammonium salts, fatty acid alkali metal salts, nitrogen-containing aromatic compounds, and tertiary ammonium salts. The trimerization catalyst used may be one type or two or more types. In the present invention, from the viewpoint of the flame retardancy of the resulting polyurethane foam, quaternary ammonium salts are preferred.

[0032] Examples of the quaternary ammonium group constituting the quaternary ammonium salt include aliphatic ammonium groups such as tetramethylammonium, methyltriethylammonium, ethyltrimethylammonium, propyltrimethylammonium, butyltrimethylammonium, pentyltrimethylammonium, hexyltrimethylammonium, heptyltrimethylammonium, octyltrimethylammonium, nonyltrimethylammonium, decyltrimethylammonium, undecyltrimethylammonium, dodecyltrimethylammonium, tridecyltrimethylammonium, tetradecyltrimethylammonium, heptadecyltrimethylammonium, hexadecyltrimethylammonium, heptadecyltrimethylammonium, and octadecyltrimethylammonium; hydroxyammonium groups such as (2-hydroxypropyl)trimethylammonium, hydroxyethyltrimethylammonium, and hydroxyethyl-2-hydroxypropyldimethylammonium; and alicyclic ammonium groups such as 1-methyl-1-azania-4-azabicyclo[2,2,2]octanium, 1,1-dimethyl-4-methylpiperidinium, 1-methylmorpholinium, and 1-methylpiperidinium.

[0033] Other organic groups constituting the quaternary ammonium salt include formic acid group, acetic acid group, octylic acid group, oxalic acid group, malonic acid group, succinic acid group, glutaric acid group, adipic acid group, benzoic acid group, toluic acid group, ethylbenzoic acid group, methylcarbonate group, phenol group, alkylbenzenesulfonic acid group, toluenesulfonic acid group, benzenesulfonic acid group, phosphate ester group, etc. Furthermore, inorganic groups constituting the quaternary ammonium salt include halogen group, hydroxy group, hydrogencarbonate group, carbonate group, etc.

[0034] Examples of the fatty acid alkali metal salts include potassium octoate, potassium 2-ethylhexanoate, and sodium acetate. Examples of the nitrogen-containing aromatic compound include tris(dimethylaminomethyl)phenol, 2,4-bis(dimethylaminomethyl)phenol, and tris(dimethylaminopropyl)hexahydrotriazine. Examples of the tertiary ammonium salt include trimethylammonium salt, triethylammonium salt, and triphenylammonium salt.

[0035] In the present invention, the content of the trimerization catalyst is preferably 0.3 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and even more preferably 1 to 4 parts by mass, relative to 100 parts by mass of the total amount of polyols constituting the polyol composition.

[0036] Examples of resinified metal catalysts include organic bismuth compounds, organic lead compounds, organic tin compounds, and organic zinc compounds. Only one type of resinified metal catalyst may be used, or two or more types may be used. In the present invention, organic bismuth compounds and organic lead compounds are preferred from the viewpoints of urethane-forming reactivity and reaction rate.

[0037] Examples of the organic bismuth compound include bismuth acetate, bismuth octoate, bismuth naphthenate, dibutyl bismuth diacetate, dibutyl bismuth dilaurate, and dioctyl bismuth dilaurate. Examples of organic lead compounds include lead acetate, lead octoate, lead octenate, lead naphthenate, dibutyl lead diacetate, dibutyl lead dilaurate, and dioctyl lead dilaurate. Examples of the organotin compound include tin octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin mercaptide, and dioctyltin thiocarboxylate. Examples of organic zinc compounds include zinc naphthenate, zinc decanoate, zinc 4-cyclohexylbutyrate, zinc neodecanoate, zinc isobutyrate, zinc benzoate, zinc p-toluenesulfonate, and zinc(II) bis-2,2,6,6-tetramethyl-3,5-heptanedionate.

[0038] In the present invention, the content of the resinified metal catalyst is preferably 0.5 to 10 parts by mass, more preferably 1 to 7 parts by mass, and even more preferably 2 to 5 parts by mass, relative to 100 parts by mass of the total amount of polyols constituting the polyol composition.

[0039] In the present invention, in addition to the resinified metal catalyst, an imidazole compound, a tertiary amine, or the like may be used as the urethanization catalyst.

[0040] The blowing agent constituting the polyol composition according to the present invention contains a halogenated olefin, and may contain other blowing agents (described later) as necessary.

[0041] Halogenated olefins are halogenated alkenes and include compounds known as hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs). The halogenated olefins according to the present invention are preferably unsaturated hydrocarbon derivatives containing a halogen atom such as a chlorine atom or a fluorine atom and having about 2 to 6 carbon atoms.

[0042] Examples of hydrofluoroolefins (HFOs) include pentafluoropropenes such as 1,2,3,3,3-pentafluoropropene (HFO1225ye), tetrafluoropropenes such as 1,3,3,3-tetrafluoropropene (HFO1234ze), 2,3,3,3-tetrafluoropropene (HFO1234yf), and 1,2,3,3-tetrafluoropropene (HFO1234ye), and trifluoropropenes such as 3,3,3-trifluoropropene (HFO1243zf), Examples include tetrafluorobutene isomers (HFO1354), pentafluorobutene isomers (HFO1345), hexafluorobutene isomers (HFO1336) such as 1,1,1,4,4,4-hexafluoro-2-butene (HFO1336mzz), heptafluorobutene isomers (HFO1327), heptafluoropentene isomers (HFO1447), octafluoropentene isomers (HFO1438), and nonafluoropentene isomers (HFO1429).

[0043] Furthermore, examples of hydrochlorofluoroolefins (HCFOs) include 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), dichlorotrifluoropropene (HCFO1223), 1-chloro-2,3,3-trifluoropropene (HCFO-1233yd), 1-chloro-1,3,3-trifluoropropene (HCFO-1233zb), 2-chloro-1,3,3-trifluoropropene (HCFO-1233xe), 2-chloro-2,2,3-trifluoropropene (HCFO-1233xc), 3-chloro-1,2,3-trifluoropropene (HCFO-1233ye), and 3-chloro-1,1,2-trifluoropropene (HCFO-1233yc).

[0044] In the present invention, the content of the halogenated olefin is preferably 10 to 50 parts by mass, more preferably 15 to 45 parts by mass, and even more preferably 20 to 40 parts by mass, relative to 100 parts by mass of the total amount of polyols constituting the polyol composition.

[0045] The blowing agent according to the present invention may contain blowing agents other than the halogenated olefin, such as hydrocarbons, other halogen-containing compounds, and water.

[0046] Examples of hydrocarbons (HC) include propane, butane, isobutane, n-pentane, isopentane, hexane, isohexane, neohexane, heptane, isoheptane, and cyclopentane.

[0047] Other halogen-containing compounds include difluoromethane (HFC32), 1,1,1,2,2-pentafluoroethane (HFC125), 1,1,1-trifluoroethane (HFC143a), 1,1,2,2-tetrafluoroethane (HFC134), 1,1,1,2-tetrafluoroethane (HFC134a), 1,1-difluoroethane (HFC152a), 1,1,1,2,3,3,3-heptafluoropropane (HFC227ea), Examples of the hydrocarbons include hydrofluorocarbons (HFCs) such as 1,1,1,3,3-pentafluoropropane (HFC245fa), 1,1,1,3,3-pentafluorobutane (HFC365mfc), 1,1,1,2,2,3,4,5,5,5-decafluoropentane (HFC4310mee), dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride.

[0048] In the present invention, a halogenated olefin may be used alone as a blowing agent, or water, which is a blowing agent source that reacts with a polyisocyanate to produce carbon dioxide gas as a blowing agent, may be used in combination with the halogenated olefin. Even when a halogenated olefin and water are used in combination, a polyurethane foam having excellent adhesion to a wooden frame and excellent heat insulating properties can be obtained. Water may or may not be contained in the polyol composition, as long as it is contained in the polyurethane foam composition.

[0049] When the polyol composition according to the present invention contains water, from the viewpoint of the heat insulating properties of the resulting polyurethane foam, the upper limit of the water content is preferably 1.2 parts by mass, more preferably 0.8 parts by mass, and even more preferably 0.5 parts by mass, relative to 100 parts by mass of the total amount of polyols constituting the polyol composition.

[0050] The polyol composition according to the present invention may further contain additives such as a foam stabilizer, a compatibilizer, a flame retardant, a plasticizer, an antioxidant, an ultraviolet absorber, an antistatic agent, an antibacterial agent, a corrosion inhibitor, a formaldehyde scavenger, and a colorant, in addition to the polyol, catalyst, and blowing agent.

[0051] The foam stabilizer may be any of nonionic, anionic, and cationic, but preferably contains a nonionic foam stabilizer. The foam stabilizer used may be one type only, or two or more types. Examples of nonionic foam stabilizers include silicone compounds such as organopolysiloxane, polyoxyalkylene-modified dimethylpolysiloxane, and polysiloxane-oxyalkylene copolymers, as well as polyoxyethylene sorbitan fatty acid esters, polyoxyethylene castor oil fatty acid esters, lauryl fatty acid ethylene oxide adducts, and polyoxyalkylene alkyl ethers. Of these, silicone compounds are preferred.

[0052] When the polyol composition according to the present invention contains a foam stabilizer, the content thereof is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 4 parts by mass, and even more preferably 1 to 3 parts by mass, relative to 100 parts by mass of the total amount of polyols constituting the polyol composition.

[0053] Examples of the compatibilizer include organic phosphate esters, nonionic surfactants, and propylene carbonate. Of these, organic phosphate esters are preferred. The compatibilizer may be used alone or in combination of two or more types.

[0054] Examples of organic phosphate esters include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(isopropylphenyl) phosphate, tris(phenylphenyl) phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl(2-ethylhexyl) phosphate, di(isopropylphenyl)phenyl phosphate, and monoisodecyl phosphate.

[0055] When the polyol composition according to the present invention contains a compatibilizer, the content thereof is preferably 1 to 20 parts by mass, more preferably 1.5 to 15 parts by mass, and even more preferably 2 to 10 parts by mass, relative to 100 parts by mass of the total amount of polyols constituting the polyol composition.

[0056] Examples of flame retardants include organic phosphate esters, phosphates, stannates, halogen compounds (excluding organic phosphate esters), boron compounds, metal hydroxides, red phosphorus, phosphoric acid ester amides, phosphonitrile compounds, organic phosphonic acid compounds, organic phosphinic acid compounds, phosphine oxides, triazole compounds, tetrazole compounds, triazine compounds, cyclic monoureides, cyclic diureides, amidine compounds, etc. Only one type of flame retardant may be used, or two or more types may be used. From the viewpoint of thermal conductivity, it is preferable to use a liquid flame retardant without including a solid flame retardant.

[0057] When the polyol composition according to the present invention contains a flame retardant, the content ratio thereof is preferably 1 to 20 parts by mass, more preferably 2 to 10 parts by mass, and even more preferably 3 to 8 parts by mass, relative to 100 parts by mass of the total amount of polyols constituting the polyol composition.

[0058] The method for producing the polyol composition according to the present invention is not particularly limited. The polyol composition can be produced by using raw material components such as a polyol, a catalyst, and a blowing agent in predetermined proportions and mixing them.

[0059] Next, the polyisocyanate composition that constitutes the polyurethane foam composition of the present invention together with the polyol composition will be described. This polyisocyanate composition contains a polyisocyanate, but may also contain a component that does not react with the isocyanate group of the polyisocyanate. Note that this polyisocyanate composition may consist solely of a polyisocyanate.

[0060] Polyisocyanate reacts with the polyol in the polyol composition to produce polyurethane (resin), and is a compound having two or more isocyanate groups in the molecule.

[0061] Examples of polyisocyanates include aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, urethane prepolymers having an isocyanate group at the molecular terminal, isocyanurate-modified polyisocyanates, carbodiimide-modified polyisocyanates, etc. The polyisocyanate composition may contain one type of polyisocyanate or two or more types of polyisocyanates.

[0062] Examples of aromatic polyisocyanates include diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, tolylene diisocyanate, polytolylene triisocyanate, xylylene diisocyanate, and naphthalene diisocyanate. Examples of aliphatic polyisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate. Examples of alicyclic polyisocyanates include isophorone diisocyanate (3-isocyanatemethyl-3,5,5-trimethylcyclohexyl isocyanate), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanatemethyl)cyclohexane, and 1,4-bis(isocyanatemethyl)cyclohexane.

[0063] In the present invention, the polyisocyanate preferably includes an aromatic polyisocyanate. The lower limit of the content of the aromatic polyisocyanate relative to the total amount of polyisocyanates constituting the polyisocyanate composition is preferably 80% by mass, more preferably 90% by mass.

[0064] The polyisocyanate composition may contain other components in addition to the polyisocyanate. As the other components, components contained in the polyol composition or components that do not react with the polyisocyanate among the additives that may be contained in the polyol composition can be used.

[0065] The polyisocyanate contained in the polyisocyanate composition of the present invention is a component that reacts with the polyol contained in the polyol composition to give a polyurethane foam with excellent heat insulation, and there is a preferred content ratio between the polyol and the polyisocyanate in the polyurethane foam composition of the present invention. In the present invention, the polyol composition and the polyisocyanate composition are configured so that the equivalent ratio (NCO / OH) of the isocyanate group of the polyisocyanate to the hydroxy group of the polyol is preferably 1 to 3, more preferably 1.1 to 2.

[0066] The polyurethane foam composition according to the present invention can be prepared by mixing a polyol composition and a polyisocyanate composition. For example, when water is used as another blowing agent, a polyol, a catalyst, a water-containing blowing agent, a catalyst, and other additives are mixed to form a polyol composition, which can then be mixed with a separately prepared polyisocyanate composition using, for example, a high-speed mixer or an impingement mixer. In the polyurethane foam production method described below, the polyurethane foam composition to be sprayed onto the surface of a wooden frame can be prepared, for example, by mixing a polyol composition and a polyisocyanate composition contained in separate containers near the tip of a spray gun.

[0067] The polyurethane foam of the present invention is a foam obtained by foaming and curing the polyurethane foam composition of the present invention, and is typically a rigid foam with a high closed cell content. As described above, the polyurethane foam of the present invention is a foam that has excellent adhesion to wooden frames and excellent heat insulating properties, due to the use of a polyol composition containing a specific polyol. The wooden frame can be a wall, pillar, ceiling, or floor, as described above, and the foam portion bonded to at least a portion of these surfaces is the polyurethane foam of the present invention. The wooden frame may have either a flat surface on which the polyurethane foam will be formed, or a surface having irregularities, grooves, holes, etc., and in the latter case, the wooden frame may have a structure in which the recesses, grooves, holes, etc. are filled with the formed polyurethane foam.

[0068] As described above, Figure 1 shows an example of a joint body comprising the polyurethane foam of the present invention, and can be, for example, a joint body 1 in which polyurethane foam 3 is formed on the surface of a wall made of flat wooden boards as a wooden frame 2.

[0069] In the joined structure comprising the polyurethane foam of the present invention, when viewed in the thickness direction of the polyurethane foam from the surface of the wooden skeleton, the polyurethane foam may have a single-layer structure or a multi-layer structure of two or more layers. In the case of a multi-layer structure, the compositions and thicknesses of the layers may be the same or different. In a preferred embodiment, each layer has the same composition. For example, a polyurethane foam having a laminated structure consisting of a first layer and a second layer, each of which has the same composition, is used from the wooden skeleton side. In this case, the first layer, which is firmly adhered to the wooden skeleton, may be a thin layer, and the thicknesses of the first and second layers may be, for example, 3 to 8 mm and 20 to 40 mm, respectively. In another embodiment, the thicknesses of both the first and second layers, and further, the thicknesses of each layer when a third, fourth, etc. layer is provided, may be set within the range of 20 to 40 mm.

[0070] The density of the polyurethane foam of the present invention, when measured by a method according to JIS K 7222, is preferably 25 to 200 kg / m 3 , more preferably 25 to 100 kg / m 3 When the polyurethane foam has a multi-layer structure, the densities of the layers may be the same or different.

[0071] The polyurethane foam of the present invention may be produced by any method. Since the wooden skeleton can be a wall, pillar, ceiling, or floor, the method may be selected depending on the surface shape, etc. When the polyurethane foam composition of the present invention is applied to the surface of the wooden skeleton to form a coating film, a foam is usually obtained simultaneously with the formation of the coating film at temperatures above 0°C. Therefore, the surface of the wooden skeleton may be heated as needed.

[0072] For example, the polyurethane foam composition can be applied to the surface of a wooden skeleton using a spray gun, roller, brush, rod, etc., or the polyurethane foam composition can be poured into the space within a container so that the wooden skeleton is placed in a predetermined position and the polyurethane foam composition comes into contact with the wooden skeleton, thereby applying the polyurethane foam composition to the surface of the wooden skeleton to form a coating film, and then reacting the polyol and polyisocyanate in the coating film to foam and cure it. For example, a method of producing a polyurethane foam using a spray gun, i.e., spraying the polyurethane foam composition onto a wooden skeleton, will be described below as the "method of producing a polyurethane foam of the present invention."

[0073] The method for producing a polyurethane foam of the present invention involves spraying a polyurethane foam composition onto the surface of a wooden skeleton and foaming and curing the composition to form a polyurethane foam. The method for spraying the polyurethane foam composition onto the surface of the wooden skeleton to form a polyurethane foam of the desired thickness is not particularly limited, and may include a method in which the polyurethane foam composition is continuously sprayed until a polyurethane foam of the desired thickness is obtained, or a method in which the spraying of the polyurethane foam composition and foaming and curing are repeated at least twice to form a polyurethane foam of the desired thickness.

[0074] In one embodiment of forming a polyurethane foam, a thin coating can be formed when the polyurethane foam composition is first sprayed onto the surface of the wooden structure, in order to allow the polyurethane foam composition to blend with the surface of the wooden structure and to obtain strong adhesion to the wooden structure, and then a thicker coating can be sprayed a second time.

[0075] The thermal conductivity of the polyurethane foam obtained by the present invention is preferably 0.019 W / mK or less when measured by a method in accordance with JIS A 1412 (1999), and the foam has excellent heat insulating properties. Furthermore, when the polyurethane foam of the present invention is stored at 60°C for 28 days, its thermal conductivity can be preferably 0.021 W / mK or less. Furthermore, when the polyurethane foam is stored at 70°C for 175 days, its thermal conductivity can be preferably 0.021 W / mK or less. Therefore, the polyurethane foam of the present invention has durability (heat resistance) in terms of heat insulation. Furthermore, the polyurethane foam of the present invention has the same thermal conductivity at a thickness of about 75 to 80% of that of a polyurethane foam obtained by using, for example, an ethylenediamine polyol instead of an aromatic polyester polyol, and therefore exhibits sufficient heat insulation even when the foam is thin. [Example]

[0076] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following description, "parts" and "%" are by mass unless otherwise specified.

[0077] 1. Raw materials for manufacturing the composition The raw materials for the polyurethane foam compositions used in the examples and comparative examples are shown below.

[0078] 1-1. Polyol 1-1-1. First polyester polyol (O-aromatic ester) The phthalic anhydride polyester polyol "Maximol RDK-133" (trade name) manufactured by Air Water Performance Chemicals Inc. was used. The aromatic concentration was 23%. 1-1-2. Second polyester polyol (P-aromatic ester) The terephthalic acid-based polyester polyol "Maximol RFK-505" (trade name) manufactured by Air Water Performance Chemicals Inc. was used. The aromatic concentration was 22%.

[0079] 1-1-3.Autocatalytic polyol (1) Ethylenediamine-based polyether polyol 1 "EXCENOL 750ED" (trade name) manufactured by AGC was used. (2) Ethylenediamine-based polyether polyol 2 "EXCENOL 500ED" (trade name) manufactured by AGC was used.

[0080] 1-2. Catalyst 1-2-1. Trimerization catalyst A quaternary ammonium salt "Kao Raiser No. 420" (trade name) manufactured by Kao Corporation was used.

[0081] 1-2-2. Resinification catalyst (1) Imidazole catalyst "Kao Raiser No. 350" (trade name) manufactured by Kao Corporation was used. (2) Tertiary amines N,N-dicyclohexylmethylamine "Polycat 12" (trade name) manufactured by Evonik Japan was used. (3) Organic carboxylic acid metal salt 1 Bismuth octylate "Pucat 25" (trade name) manufactured by Nippon Chemical Industry Co., Ltd. was used. (4) Organic carboxylic acid metal salt 2 Lead octylate "Lead Hexoate 20%" (trade name) manufactured by Toei Kako Co., Ltd. was used.

[0082] 1-3. Foaming agents (1) Non-fluorocarbon blowing agents 1-chloro-3,3,3-trifluoropropene "HCFO-1233zd" (trade name) manufactured by Honeywell was used. (2)Water

[0083] 1-4.Foam stabilizer Silicone foam stabilizer "Niax" manufactured by Momentive Performance Materials Japan, LLC TM Silicone L-6100 (trade name) was used.

[0084] 1-5. Compatibilizer The organic phosphate ester "Tris(1-chloro-2-propyl)phosphate" (trade name) manufactured by Wanxiang Co., Ltd. was used.

[0085] 1-6. Polyisocyanate A polymeric MDI "Wannate PM-130" (trade name) manufactured by Wanka Chemical Japan Co., Ltd. was used.

[0086] 2. Production and evaluation of polyurethane foam compositions The above-mentioned raw materials were used to produce a polyurethane foam composition, which was then used to produce a foam and to carry out various evaluations.

[0087] Example 1 50 parts of O-aromatic ester, 50 parts of P-aromatic ester, 1.5 parts of quaternary ammonium salt, 1.5 parts of imidazole catalyst, 1.0 part of tertiary amine, 1.0 part of bismuth octylate, 1.5 parts of foam stabilizer, 8 parts of compatibilizer, and 30 parts of non-fluorocarbon blowing agent were stirred and mixed to obtain a polyol composition (see Table 1). Thereafter, the resulting polyol composition (144.5 parts in total) and 144.5 parts of polyisocyanate were stirred and mixed to obtain a polyurethane foam composition.

[0088] Next, polyurethane foam was produced using the obtained polyurethane foam composition. Then, foam test pieces of sizes suitable for the following evaluation items were prepared, and density and thermal conductivity were measured. In addition, the thermal resistance value was 1.92 m 2 The thickness equivalent to K / W was calculated, and the adhesiveness to a cedar board (thickness 12.5 mm) was also evaluated. The results are shown in Table 1.

[0089] (1) Density The density was measured by a method conforming to JIS K 7222. Specifically, a polyurethane foam composition was sprayed onto a wooden board and cured to produce a polyurethane foam, which was then left to stand for 24 hours in an atmosphere of 23°C and 50% RH. The polyurethane foam was then machined to cut foam test pieces measuring 100 mm (length) × 100 mm (width) × 30 mm (thickness) from the core, and the density was measured.

[0090] (2) Thermal conductivity The thermal conductivity of the foam test specimens was measured using a thermal conductivity measuring device "Autolambda HC-074" (trade name) manufactured by Eiko Seiki Co., Ltd., according to a method conforming to JIS A 1412 (1999). Specifically, according to a method conforming to JIS A 9526 (2022), that is, a polyurethane foam composition was sprayed onto a wooden board and cured to produce a polyurethane foam. The polyurethane foam was then left to stand for 24 hours in an atmosphere of 23 ° C and 50% RH, and then machined to cut foam test specimens measuring 200 mm (length) × 200 mm (width) × 25 mm (thickness) from the core. The thermal conductivity of the test specimens (initial thermal conductivity) was then measured within one day of this cutting, and the thermal conductivity of the test specimens was measured after storing them at 60 ° C in a dry atmosphere for 28 days (thermal conductivity after 28 days). Separately, a polyurethane foam was produced by spraying it onto a wooden board and letting it harden. This was then stored at 70°C in a dry atmosphere for 175 days, after which the polyurethane foam was machined to cut foam test pieces measuring 200mm (length) x 200mm (width) x 25mm (thickness) from the core, and the thermal conductivity of the test pieces (thermal conductivity after 175 days) was measured.

[0091] (3) Thermal resistance is 1.92 m 2 ·K / W equivalent thickness The thermal conductivity of the foam test piece after storing it at 60°C in a dry atmosphere for 28 days was 0.026 W / m K (equivalent to the thermal conductivity of Comparative Example 1), and the thermal resistance was 1.92 m when the thickness was 50 mm. 2 K / W, thermal conductivity and thermal resistance (1.92m) after storage at 60°C in a dry atmosphere for 28 days 2 By multiplying this by 1.92m / s, the thermal resistance is 1.92m 2 ·The wall thickness equivalent to K / W was calculated.

[0092] (4) Wood board adhesion The polyurethane foam composition was sprayed onto a wooden board in two separate applications and cured to obtain a wooden board with a polyurethane foam-coated structure comprising a foam with a laminated structure of first and second layers, as viewed from the wooden board. The thickness of both the first and second layers was 30 mm. Then, a wooden board test piece with a polyurethane foam was prepared for adhesive evaluation, with the foam portion measuring 50 mm x 50 mm x 30 mm (thickness), and adhesive strength was measured according to JIS A 9526. The breaking load at which the foam portion broke or peeled from the wooden board was measured, and adhesiveness was evaluated according to the following criteria. 〇: 200kPa or more △: 100kPa or more and less than 200kPa ×: Less than 100 kPa

[0093] Examples 2 to 8 and Comparative Examples 1 to 5 Polyurethane foams were produced in the same manner as in Example 1, except that the types and amounts of raw materials used were as shown in Table 1. Thereafter, various evaluations were carried out (see Table 1).

[0094] [Table 1]

[0095] Table 1 reveals the following: Comparative Examples 1 and 2 are examples in which a polyol containing no aromatic polyester polyol was used; the resulting polyurethane foam had high thermal conductivity, insufficient heat insulation, and insufficient adhesion to wooden boards. Comparative Example 3 is an example in which a blowing agent containing no halogenated olefin was used; the resulting polyurethane foam had high thermal conductivity, insufficient heat insulation, and insufficient adhesion to wooden boards. Comparative Example 4 is an example in which a polyol composition containing no resinified metal catalyst (bismuth octoate) was used; the resulting polyurethane foam had high thermal conductivity, insufficient heat insulation, and insufficient adhesion to wooden boards. Comparative Example 5 is an example in which a polyol composition containing no trimerization catalyst was used; the resulting polyurethane foam had high thermal conductivity, insufficient heat insulation, and insufficient adhesion to wooden boards. On the other hand, Examples 1 to 8 are examples in which the polyurethane foam composition according to the present invention was used, and the resulting polyurethane foams had low thermal conductivity, excellent heat insulation, and excellent adhesion to wooden boards. Furthermore, the polyurethane foams obtained in Examples 1 to 8 had the same thermal conductivity as the polyurethane foam of Comparative Example 1 at a thickness of 75 to 80% of that of the polyurethane foam obtained in Comparative Example 1, demonstrating that they have excellent heat insulation properties even when thin-walled. [Industrial Applicability]

[0096] The polyurethane foam of the present invention is suitable as a heat insulating material for wooden walls, pillars, ceilings, roofs, and underfloor surfaces facing the underfloor space in detached houses, apartments, public facilities, warehouses, etc. [Explanation of symbols]

[0097] 1:Zygote 2: Wooden frame 3: Polyurethane foam

Claims

1. A polyurethane foam is produced by applying a polyurethane foam composition containing a polyol composition including a polyol, a catalyst, and a blowing agent, and a polyisocyanate composition including a polyisocyanate, to a surface of a wooden skeleton, and foaming and curing the polyurethane foam composition on the surface of the wooden skeleton to form a polyurethane foam bonded to the surface of the wooden skeleton, the polyol comprises an aromatic polyester polyol; the catalyst comprises a trimerization catalyst and a resinification metal catalyst; The foaming agent comprises a halogenated olefin. The foam is bonded to the surface of a wooden frame.

2. Density: 25 to 200 kg / m ３ 2. The polyurethane foam according to claim 1, wherein

3. 2. The polyurethane foam according to claim 1, wherein the polyurethane foam has a laminated structure consisting of a first layer and a second layer, each having the same composition, arranged from the wooden frame side.

4. 2. The polyurethane foam according to claim 1, wherein the aromatic polyester polyol has an aromatic moiety content of 15% or more.

5. The polyurethane foam according to claim 1 , wherein the aromatic polyester polyol comprises a phthalate-based polyester polyol.

6. the phthalic acid-based polyester polyol includes a first polyester polyol formed from o-phthalic acid or its anhydride and a diol, and a second polyester polyol formed from terephthalic acid and a diol; The polyurethane foam according to claim 5 , wherein the ratio of the total amount of the first polyester polyol and the second polyester polyol to the total amount of the aromatic polyester polyol is 80% by mass or more.

7. 10. The polyurethane foam according to claim 1, wherein said polyol further comprises an autocatalytic polyol.

8. The polyurethane foam according to claim 1 , wherein the polyurethane foam composition further contains a phosphate ester.

9. The polyurethane foam according to claim 1, wherein the polyurethane foam composition further contains water.

10. The polyurethane foam according to claim 1, wherein the wooden structure is a wall, a pillar, a ceiling, or a floor.

11. 2. The polyurethane foam according to claim 1, which has a thermal conductivity of 0.021 W / mK or less after storage at 60°C for 28 days.

12. 2. The polyurethane foam according to claim 1, which has a thermal conductivity of 0.021 W / mK or less after storage at 70°C for 175 days.

13. 10. A method for producing the polyurethane foam of claim 1, comprising: The method for producing a polyurethane foam on the surface of a wooden skeleton comprises spraying the polyurethane foam composition onto the surface of the wooden skeleton, and allowing the composition to foam and cure to form a polyurethane foam.

14. The method for producing a polyurethane foam according to claim 13, wherein the steps of spraying the polyurethane foam composition and foaming and curing are repeated at least twice to form a laminate.

15. 14. The method for producing a polyurethane foam according to claim 13, wherein the initial thermal conductivity of the resulting polyurethane foam is 0.019 W / mK or less.

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