Method for producing polyurethane foam

Abstract

To produce a polyurethane foam having excellent quality by preventing the degradation of liquid even in the design with a filler added thereto.SOLUTION: A method for producing a polyurethane foam includes the steps of: preparing liquid A and liquid B; mixing the liquid A and liquid B to make polyol liquid; and mixing the polyol liquid and isocyanate liquid. The liquid A contains a filler and a foamer. The liquid B contains a catalyst. At least one of the liquid A and liquid B contains a polyol.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing a polyurethane foam containing a filler. [Background technology]

[0002] A common method for producing polyurethane foam is to mix an isocyanate liquid containing a polyisocyanate with a polyol liquid containing a polyol and then foam the mixture. In this method, a blowing agent and a catalyst are added to one or both of the liquids to obtain the polyurethane foam, but the blowing agent and catalyst are generally added to the polyol liquid.

[0003] Furthermore, in order to impart additional functionality to polyurethane foams, the liquid formulation may be designed to contain components other than polyisocyanate, polyol, catalyst, and blowing agent. One such design involves attempts to add fillers, and Patent Document 1, for example, reports that flame retardancy can be improved by blending a solid flame retardant. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2014 / 112394 Summary of the Invention [Problem to be solved by the invention]

[0005] It has been reported that some of the blowing agents used in polyurethane foams affect catalysts and accelerate their deterioration. For this reason, a system has been attempted in which the liquid containing the catalyst and the blowing agent are stored separately and mixed just before foaming in a foaming machine.

[0006] However, in a design in which a filler is added to a liquid formulation as described above, the inventors have found that, even if a foaming agent is not contained, if the filler and catalyst are mixed in the liquid formulation, deterioration will progress during storage, etc. Therefore, simply storing the liquid containing the catalyst and the blowing agent separately may not be enough to prevent the liquid from deteriorating, and it may not be possible to produce a urethane foam of good quality.

[0007] Therefore, an object of the present invention is to provide a method for producing polyurethane foam that can prevent deterioration of the liquid agent during storage, etc., even in designs that include added fillers, and can produce polyurethane foam of good quality. [Means for solving the problem]

[0008] The gist of the present invention is as follows (1) to (7). (1) preparing liquid A and liquid B; A step of mixing the liquid agent A and the liquid agent B to obtain a polyol liquid agent; and mixing the polyol liquid agent and the isocyanate liquid agent, A method for producing a polyurethane foam, wherein the liquid agent A contains a filler and a blowing agent, the liquid agent B contains a catalyst, and at least one of the liquid agents A and B contains a polyol. (2) preparing liquid A1, liquid A2, and liquid B; A step of mixing the liquid agent A1, the liquid agent A2, and the liquid agent B to obtain a polyol liquid agent; and mixing the polyol liquid agent and the isocyanate liquid agent, A method for producing a polyurethane foam, wherein the liquid agent A1 contains a filler, the liquid agent A2 contains a blowing agent, the liquid agent B contains a catalyst, and at least one of the liquid agents A1, A2, and B contains a polyol. (3) A method for producing a polyurethane foam according to (1) above, comprising mixing the liquids A and B so that the mass ratio of the liquid A is higher than that of the liquid B, to obtain a polyol liquid. (4) A method for producing a polyurethane foam according to (2) above, in which the liquid A1, the liquid B, and the liquid A2 are mixed so that the mass ratio of the liquid A1 is higher than the mass ratios of the liquid B and the liquid A2, respectively, to obtain a polyol liquid. (5) The method for producing a polyurethane foam according to any one of the above (1) to (4), wherein the viscosity of the polyol liquid at 25° C. and 60 rpm is 200 to 2500 mPa·s. (6) The method for producing a polyurethane foam according to any one of the above (1) to (5), wherein the blowing agent contains a hydrofluoroolefin-based compound. (7) A method for producing a polyurethane foam according to any one of (1) to (6) above, wherein the filler contains a solid flame retardant, and the solid flame retardant is at least one selected from the group consisting of red phosphorus-based flame retardants, boron-containing flame retardants, bromine-containing flame retardants, phosphate-containing flame retardants, chlorine-containing flame retardants, antimony-containing flame retardants, metal hydroxides, and needle-like fillers. [Effects of the Invention]

[0009] According to the present invention, even in designs in which a filler is added, it is possible to prevent the deterioration of the liquid agent during storage, etc., and to produce polyurethane foams of good quality. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a conceptual diagram showing a method for producing a polyurethane foam according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The method for producing a polyurethane foam of the present invention will be described in detail below using embodiments. The method for producing a polyurethane foam according to one embodiment of the present invention is either the following first or second method.

[0012] <Method 1> The first method includes the following steps 1 to 3. (Step 1) A step of preparing liquid agent A1, liquid agent A2, and liquid agent B (Step 2) mixing the liquid agent A1, the liquid agent A2, and the liquid agent B to obtain a polyol liquid agent; (Step 3) Mixing the polyol liquid and the isocyanate liquid In the first method, liquid agent A1 contains a filler, liquid agent A2 contains a blowing agent, liquid agent B contains a catalyst, and at least one of liquid agents A1, A2, and B contains a polyol.

[0013] In the first method described above, the raw materials for forming the polyurethane foam are stored in the form of liquids A1, A2, and B, and then, prior to use, a polyol liquid is prepared in step 2. Next, in step 3, the polyol liquid and the isocyanate liquid are mixed and the mixture is foamed to produce the polyurethane foam. This method prevents the filler and catalyst, and the blowing agent and catalyst, from being stored in a mixed state, thereby preventing deterioration of the liquid agent due to storage and enabling the production of polyurethane foams of good quality. Furthermore, by making the liquid agent A1 containing the filler a separate liquid agent from the liquid agent A2 containing the foaming agent, the viscosity can be increased, so that even when the liquid agent A1 is stored at room temperature or below room temperature (for example, below 30°C), it is possible to prevent the filler from settling and causing hard caking.

[0014] <Second Method> The second method includes the following steps 1 to 3. (Step 1) Preparation of liquid A and liquid B (Step 2) A step of mixing the liquid agent A and the liquid agent B to obtain a polyol liquid agent. (Step 3) Mixing the polyol liquid and the isocyanate liquid In the second method, liquid agent A contains a filler and a blowing agent, liquid agent B contains a catalyst, and at least one of liquid agents A and B contains a polyol. That is, in the first method, the filler and the foaming agent are contained in different liquid agents A1 and A2, respectively, but in the second method, the filler and the foaming agent are contained in the same liquid agent A.

[0015] In the second method described above, the raw materials for forming the polyurethane foam are stored in the form of liquids A and B, and then, prior to use, a polyol liquid is prepared in step 2. Next, in step 3, the polyol liquid and the isocyanate liquid are mixed and the mixture is foamed to produce the polyurethane foam. This method prevents the filler, blowing agent, and catalyst from being stored in a mixed state, thereby preventing deterioration of the liquid agent due to storage and allowing the production of polyurethane foams of good quality. In addition, in this method, liquid agent A1 containing the filler in the first method is combined with liquid agent A2 containing a foaming agent to form liquid agent A, which simplifies the mixer system and makes lot management easier. The "liquid" may be in a liquid state either during preparation of each liquid, during storage until mixing with other liquids, or during mixing with other liquids, but typically is in a liquid state from preparation of each liquid until mixing with other liquids, preferably at room temperature (23°C) and normal pressure (1 atmosphere). Of course, each liquid may contain solids such as fillers, and may therefore be in a slurry state.

[0016] <Polyol liquid> In the present invention, as described above, a polyol liquid is obtained by mixing Liquid A1, Liquid A2 and Liquid B, or Liquid A and Liquid B. Below, the components used in each liquid as raw materials for the polyol liquid will be described in detail.

[0017] [Polyol] As described above, in the first method, the polyol is contained in at least one of the liquid agents A1, A2, and B. Preferably, the polyol is contained in at least one of the liquid agents A1 and B. In this case, the polyol may be contained only in the liquid agent A1, only in the liquid agent B, or both in the liquid agents A1 and B. As described above, in the second method, the polyol is contained in at least one of the liquid agents A and B. In this case, the polyol may be contained only in the liquid agent A, only in the liquid agent B, or both in the liquid agents A and B.

[0018] In the first and second methods, by further containing a polyol in the filler-containing liquid A1 or liquid A, the filler can be easily dispersed in the liquid A1 or liquid A, improving the handleability of the liquid A1 or liquid A. Furthermore, by further containing a polyol in the catalyst-containing liquid B, the catalyst can be easily dissolved or dispersed in the liquid B, improving the handleability of the liquid B.

[0019] Examples of polyols include polylactone polyols, polycarbonate polyols, aromatic polyols, alicyclic polyols, polyester polyols, polymer polyols, and polyether polyols.

[0020] Examples of polylactone polyols include polypropiolactone glycol, polycaprolactone glycol, and polyvalerolactone glycol. Examples of polycarbonate polyols include polyols obtained by dealcoholization reaction of hydroxyl group-containing compounds such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, and nonanediol with ethylene carbonate, propylene carbonate, and the like.

[0021] Examples of aromatic polyols include bisphenol A, bisphenol F, phenol novolac, and cresol novolac. Examples of alicyclic polyols include cyclohexanediol, methylcyclohexanediol, isophoronediol, dicyclohexylmethanediol, and dimethyldicyclohexylmethanediol.

[0022] Examples of polyester polyols include polymers obtained by dehydration condensation of polybasic acids and polyhydric alcohols, and condensates of hydroxycarboxylic acids and the above-mentioned polyhydric alcohols. Examples of polybasic acids include adipic acid, azelaic acid, sebacic acid, isophthalic acid (m-phthalic acid), terephthalic acid (p-phthalic acid), and succinic acid. Examples of polyhydric alcohols include bisphenol A, ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexane glycol, and neopentyl glycol. Examples of hydroxycarboxylic acids include castor oil and reaction products of castor oil and ethylene glycol.

[0023] Examples of polymer polyols include polymers obtained by graft polymerizing an ethylenically unsaturated compound such as acrylonitrile, styrene, methyl acrylate, or methacrylate with an aromatic polyol, alicyclic polyol, aliphatic polyol, or polyester polyol, polybutadiene polyol, or hydrogenated products thereof.

[0024] Examples of polyether polyols include polymers obtained by ring-opening polymerization of at least one alkylene oxide, such as ethylene oxide, propylene oxide, or tetrahydrofuran, in the presence of at least one low-molecular-weight active hydrogen compound having two or more active hydrogens. Examples of low-molecular-weight active hydrogen compounds having two or more active hydrogens include diols such as bisphenol A, ethylene glycol, propylene glycol, butylene glycol, and 1,6-hexanediol, triols such as glycerin and trimethylolpropane, and amines such as ethylenediamine and butylenediamine.

[0025] The polyol used in the present invention preferably contains at least one selected from polyester polyols and polyether polyols, and more preferably contains at least a polyester polyol, and more preferably contains a polyester polyol obtained by dehydration condensation of a polybasic acid having an aromatic ring, such as isophthalic acid (m-phthalic acid) or terephthalic acid (p-phthalic acid), with a dihydric alcohol, such as bisphenol A, ethylene glycol, or 1,2-propylene glycol. In this case, the content of at least one selected from polyester polyols and polyether polyols is preferably 50 to 100 parts by mass, more preferably 70 to 100 parts by mass, and even more preferably 85 to 100 parts by mass, per 100 parts by mass of polyol. The polyol used in combination with at least one selected from polyester polyols and polyether polyols is not particularly limited and may be appropriately selected from the above, and examples thereof include the aliphatic polyols described above.

[0026] The hydroxyl value of the polyol is preferably 20 to 350 mgKOH / g, more preferably 30 to 300 mgKOH / g. When the hydroxyl value of the polyol is equal to or less than the upper limit, the viscosity of the polyol liquid does not become excessively high, which is preferable from the viewpoint of handleability, etc. On the other hand, when the hydroxyl value of the polyol is equal to or more than the lower limit, the crosslink density of the polyurethane foam increases, thereby increasing the strength. The hydroxyl value of the polyol can be measured in accordance with JIS K 1557-1:2007.

[0027] [catalyst] In both the first and second methods, the catalyst is contained in liquid agent B. Examples of the catalyst include a resinification catalyst and a trimerization catalyst. From the viewpoint of properly progressing the urethanization reaction and the trimerization reaction and obtaining a polyurethane foam with excellent flame retardancy, the catalyst preferably contains both a resinification catalyst and a trimerization catalyst.

[0028] (resinification catalyst) The resinification catalyst is a catalyst that promotes the reaction between polyol and polyisocyanate, and examples of the resinification catalyst include amine-based catalysts such as imidazole compounds and piperazine compounds, and metal-based catalysts. Examples of imidazole compounds include tertiary amines in which the secondary amine at the 1-position of the imidazole ring is substituted with an alkyl group, an alkenyl group, or the like. Specific examples include N-methylimidazole, 1,2-dimethylimidazole, 1-ethyl-2-methylimidazole, 1-methyl-2-ethylimidazole, 1,2-diethylimidazole, and 1-isobutyl-2-methylimidazole. Other examples include imidazole compounds in which the secondary amine in the imidazole ring is substituted with a cyanoethyl group. Furthermore, examples of the piperazine compound include tertiary amines such as N-methyl-N',N'-dimethylaminoethylpiperazine and trimethylaminoethylpiperazine. Examples of the amine catalyst include, in addition to imidazole compounds and piperazine compounds, various tertiary amines such as pentamethyldiethylenetriamine, triethylamine, N-methylmorpholinebis(2-dimethylaminoethyl)ether, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N'-trimethylaminoethyl-ethanolamine, bis(2-dimethylaminoethyl)ether, N,N-dimethylcyclohexylamine, diazabicycloundecene, triethylenediamine, tetramethylhexamethylenediamine, and tripropylamine. As the amine catalyst, an imidazole compound is preferred.

[0029] Examples of metal catalysts include metal salts of lead, tin, bismuth, copper, zinc, cobalt, nickel, etc., and preferably organic acid metal salts of lead, tin, bismuth, copper, zinc, cobalt, nickel, etc. More preferred are organic acid tin salts such as dibutyltin dilaurate, dioctyltin dilaurate, and dioctyltin versatate, and organic acid bismuth salts such as bismuth trioctate and bismuth tris(2-ethylhexanoate), and among these, organic acid bismuth salts are preferred. The resinification catalyst may be used alone or in combination of two or more. The resinification catalyst is preferably at least one selected from amine catalysts and metal catalysts, and it is also preferable to use an amine catalyst and a metal catalyst in combination.

[0030] The content of the resinification catalyst in the polyol liquid is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 17 parts by mass, and even more preferably 0.3 to 15 parts by mass, relative to 100 parts by mass of the polyol. When the content of the resinification catalyst is within this range, the reaction between the polyol and the isocyanate tends to proceed appropriately.

[0031] (trimerization catalyst) The trimerization catalyst is a catalyst that promotes the trimerization of isocyanate groups contained in polyisocyanate to form isocyanurate rings. Examples of the trimerization catalyst include nitrogen-containing aromatic compounds, alkali metal salts, and ammonium salts. Examples of the nitrogen-containing aromatic compound include tris(dimethylaminomethyl)phenol, 2,4-bis(dimethylaminomethyl)phenol, and 2,4,6-tris(dialkylaminoalkyl)hexahydro-S-triazine. Examples of the alkali metal salt include alkali metal carboxylates, such as potassium carboxylates, such as potassium acetate, potassium 2-ethylhexanoate, and potassium octoate. Examples of ammonium salts that can be used include tertiary ammonium salts such as trimethylammonium salt, triethylammonium salt, and triphenylammonium salt, and quaternary ammonium salts such as tetramethylammonium salt, tetraethylammonium salt, tetraphenylammonium salt, triethylmonomethylammonium salt, and quaternary ammonium carboxylate salt. A specific example of a suitable carboxylic acid in the ammonium carboxylate is at least one selected from the group consisting of 2-ethylhexanoic acid, 2,2-dimethylpropanoic acid, acetic acid, and formic acid. The trimerization catalyst may be used alone or in combination of two or more kinds, but it is preferable to use two or more kinds in combination. The trimerization catalyst is preferably at least one selected from the group consisting of alkali metal carboxylates and quaternary ammonium carboxylates, and it is also preferable to use a combination of a metal carboxylate and a quaternary ammonium carboxylate.

[0032] The content of the trimerization catalyst in the polyol liquid is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 17 parts by mass, and even more preferably 0.3 to 15 parts by mass, relative to 100 parts by mass of the polyol. When the content of the trimerization catalyst is within this range, the trimerization reaction can proceed appropriately, and the physical properties of the polyurethane foam, such as flame retardancy, can be improved.

[0033] The content of the catalyst in the polyol liquid is preferably 0.2 to 40 parts by mass, more preferably 0.4 to 35 parts by mass, and even more preferably 0.6 to 30 parts by mass, relative to 100 parts by mass of the polyol. When the content of the catalyst is within this range, the reactivity between the polyol and the polyisocyanate becomes appropriate, and it becomes easier to obtain a polyurethane foam that has good foaming properties and is flame-retardant. The catalyst content refers to the total amount of catalyst contained in the polyol liquid, and for example, when a resinification catalyst and a trimerization catalyst are used as catalysts, it refers to the total amount of the resinification catalyst and the trimerization catalyst. As will be described later, catalysts are generally diluted with a diluent such as an organic solvent before being blended into liquid B, but the catalyst content refers to the amount of active ingredient excluding the diluent. Generally, the diluent is the solvent and the active ingredient is the solute, and the amount of active ingredient is the amount of solute.

[0034] Depending on the combination of catalysts, catalyst components diluted with a diluent may precipitate when the catalysts are mixed, and therefore, in selecting catalysts, it is preferable to use a combination of only basic, basic and neutral, only acidic, or acidic and neutral. For example, a combination of an amine catalyst as a urethanization catalyst and an ammonium salt as a trimerization catalyst, an amine catalyst as a urethanization catalyst and an alkali metal salt as a trimerization catalyst, an amine catalyst as a urethanization catalyst, a metal catalyst as a urethanization catalyst and an alkali metal salt as a trimerization catalyst, or an amine catalyst as a urethanization catalyst and an ammonium salt and an alkali metal salt as a trimerization catalyst is preferred.

[0035] [Filler] The liquid polyol contains a filler. By including a filler in the liquid polyol, it is possible to impart functionality to the polyurethane foam according to the type of filler. The filler preferably contains a flame retardant. By using a flame retardant as a filler, it is possible to impart high flame retardancy to the polyurethane foam. In the first method, the filler is contained in liquid A1. In the second method, the filler is contained in liquid A. In the present invention, by using liquid A or liquid A1, which is different from liquid B containing a catalyst, as the liquid containing the filler, the liquids A, A1, A2, and B are less likely to deteriorate even when stored for a long period of time. Therefore, polyurethane foams having good quality can be produced even after the liquids have been stored for a long period of time.

[0036] (Solid flame retardant) The flame retardant used as a filler is a solid flame retardant. In the present invention, the use of a solid flame retardant can more effectively improve flame retardancy. Note that a solid flame retardant is a flame retardant that is solid at room temperature (23°C) and normal pressure (1 atmosphere). The solid flame retardant may be at least one selected from red phosphorus-based flame retardants, boron-containing flame retardants, bromine-containing flame retardants, phosphate-containing flame retardants, chlorine-containing flame retardants, antimony-containing flame retardants, metal hydroxides, and needle-shaped fillers. The use of these solid flame retardants can effectively improve flame retardancy. These may be used alone or in combination of two or more.

[0037] <Red phosphorus flame retardant> The red phosphorus-based flame retardant may consist of red phosphorus alone, or may be red phosphorus coated with a resin, metal hydroxide, metal oxide, or the like, or may be red phosphorus mixed with a resin, metal hydroxide, metal oxide, or the like. The resin that coats or mixes with red phosphorus is not particularly limited, but examples include thermosetting resins such as phenolic resin, epoxy resin, unsaturated polyester resin, melamine resin, urea resin, aniline resin, and silicone resin. From the viewpoint of flame retardancy, metal hydroxides are preferred as the compound to be coated or mixed. The metal hydroxide to be used may be appropriately selected from those described below.

[0038] The content of the red phosphorus-based flame retardant is preferably 3 to 60 parts by mass, more preferably 10 to 55 parts by mass, and even more preferably 20 to 50 parts by mass, relative to 100 parts by mass of the polyol. By setting the content of the red phosphorus-based flame retardant to be equal to or greater than these lower limits, the effect of including the red phosphorus-based flame retardant can be easily exerted. On the other hand, by setting the content to be equal to or less than the upper limits, foaming is not inhibited by the red phosphorus-based flame retardant.

[0039] <Boron-containing flame retardants> Examples of boron-containing flame retardants include borax, boron oxide, boric acid, borate salts, etc. Examples of boron oxide include diboron trioxide, boron trioxide, diboron dioxide, tetraboron trioxide, and tetraboron pentoxide. Examples of borates include borates of alkali metals, alkaline earth metals, elements of Groups 4, 12, and 13 of the periodic table, and ammonium. Specific examples include alkali metal borates such as lithium borate, sodium borate, potassium borate, and cesium borate, alkaline earth metal borates such as magnesium borate, calcium borate, and barium borate, zirconium borate, zinc borate, aluminum borate, and ammonium borate. The boron-containing flame retardants may be used alone or in combination of two or more. Preferably, the boron-containing flame retardant is a borate, more preferably zinc borate.

[0040] The content of the boron-containing flame retardant is not particularly limited, but is preferably 3 to 45 parts by mass, more preferably 5 to 40 parts by mass, and even more preferably 10 to 25 parts by mass, relative to 100 parts by mass of the polyol. By setting the content of the boron-containing flame retardant at or above these lower limits, the effect of the boron-containing flame retardant is more easily exerted, and flame retardancy is improved. On the other hand, by setting the content at or below the upper limits, foaming is not inhibited by the boron-containing flame retardant.

[0041] <Bromine-containing flame retardants> The bromine-containing flame retardant is not particularly limited as long as it contains bromine in its molecular structure and is a compound that is solid at room temperature and normal pressure, and examples thereof include brominated aromatic ring-containing aromatic compounds. Examples of the brominated aromatic ring-containing aromatic compound include monomeric organic bromine compounds such as hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, bis(pentabromophenoxy)ethane, ethylenebis(pentabromophenyl), ethylenebis(tetrabromophthalimide), and tetrabromobisphenol A.

[0042] The brominated aromatic ring-containing aromatic compound may also be a bromine compound polymer. Specific examples include brominated polycarbonates such as polycarbonate oligomers produced using brominated bisphenol A as a raw material, copolymers of the polycarbonate oligomers with bisphenol A, and diepoxy compounds produced by reacting brominated bisphenol A with epichlorohydrin. Further examples include brominated epoxy compounds such as monoepoxy compounds obtained by reacting brominated phenols with epichlorohydrin, poly(brominated benzyl acrylate), brominated phenol condensates of brominated polyphenylene ether, brominated bisphenol A, and cyanuric chloride, brominated (polystyrene), poly(brominated styrene), brominated polystyrenes such as crosslinked brominated polystyrene, and crosslinked or non-crosslinked brominated poly(methylstyrene). Furthermore, compounds other than brominated aromatic ring-containing aromatic compounds such as hexabromocyclododecane may also be used. These bromine-containing flame retardants may be used alone or in combination of two or more. Among the above, brominated aromatic ring-containing aromatic compounds are preferred, and among them, monomeric organic bromine compounds such as ethylenebis(pentabromophenyl) are preferred.

[0043] The content of the bromine-containing flame retardant is preferably 3 to 60 parts by mass, more preferably 10 to 50 parts by mass, and even more preferably 20 to 45 parts by mass, relative to 100 parts by mass of the polyol. By setting the content of the bromine-containing flame retardant to these lower limits or more, the effect of including the bromine-containing flame retardant can be easily exerted. On the other hand, by setting the content to the upper limits or less, foaming is not inhibited by the bromine-containing flame retardant.

[0044] <Phosphate-containing flame retardants> Examples of phosphate-containing flame retardants include phosphates formed from salts of various phosphoric acids with at least one metal or compound selected from metals of Groups IA to IVB of the periodic table, ammonia, aliphatic amines, aromatic amines, and heterocyclic compounds containing nitrogen in the ring. The phosphoric acid is not particularly limited, but examples thereof include monophosphoric acid, pyrophosphoric acid, and polyphosphoric acid. Examples of metals in Groups IA to IVB of the periodic table include lithium, sodium, calcium, barium, iron (II), iron (III), and aluminum. Examples of the aliphatic amine include methylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, piperazine, etc. Examples of the aromatic amine include aniline, o-toliidine, 2,4,6-trimethylaniline, anisidine, 3-(trifluoromethyl)aniline, etc. Examples of the heterocyclic compound containing nitrogen in the ring include pyridine, triazine, melamine, etc.

[0045] Specific examples of phosphate-containing flame retardants include monophosphates such as aluminum triphosphate, pyrophosphates, polyphosphates, etc. Here, the polyphosphates are not particularly limited, but examples include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium amide polyphosphate, aluminum polyphosphate, etc. The phosphate-containing flame retardant may be one or more of the above-mentioned compounds.

[0046] The content of the phosphate-containing flame retardant is not particularly limited, but is preferably 3 to 40 parts by mass, more preferably 5 to 35 parts by mass, and even more preferably 10 to 30 parts by mass, per 100 parts by mass of polyol. By making the content of the phosphate-containing flame retardant equal to or greater than these lower limits, the effect of including the phosphate-containing flame retardant is easily exhibited. On the other hand, by making the content equal to or less than the upper limits, foaming is not inhibited by the phosphate-containing flame retardant.

[0047] <Chlorine-containing flame retardants> Chlorine-containing flame retardants include those commonly used in flame-retardant resin compositions, such as polychlorinated naphthalene, chlorendic acid, and dodecachlorododecahydrodimethanodibenzocyclooctene, which is sold under the trade name "Dechlorane Plus." The content of the chlorine-containing flame retardant is not particularly limited, but is preferably 3 to 40 parts by mass, more preferably 5 to 35 parts by mass, and even more preferably 10 to 30 parts by mass, relative to 100 parts by mass of the polyol. By making the content of the chlorine-containing flame retardant equal to or greater than these lower limits, the effect of including the chlorine-containing flame retardant can be easily exerted. On the other hand, by making the content equal to or less than the upper limits, foaming is not inhibited by the chlorine-containing flame retardant.

[0048] <Antimony-containing flame retardants> Examples of antimony-containing flame retardants include antimony oxide, antimony salts, and pyroantimony salts. Examples of antimony oxide include antimony trioxide and antimony pentoxide. Examples of antimony salts include sodium antimonate and potassium antimonate. Examples of pyroantimonate salts include sodium pyroantimonate and potassium pyroantimonate. The antimony-containing flame retardant may be used alone or in combination of two or more. The preferred antimony-containing flame retardant for use in the present invention is antimony trioxide.

[0049] The content of the antimony-containing flame retardant is not particularly limited, but is preferably 1 to 40 parts by mass, more preferably 2 to 35 parts by mass, and even more preferably 3 to 30 parts by mass, relative to 100 parts by mass of polyol. By setting the content of the antimony-containing flame retardant at or above these lower limits, the effect of the antimony-containing flame retardant is more easily exerted, and flame retardancy is improved. On the other hand, by setting the content at or below the upper limits, foaming is not inhibited by the antimony-containing flame retardant.

[0050] <Metal hydroxide> Examples of metal hydroxides used in the present invention include magnesium hydroxide, calcium hydroxide, aluminum hydroxide, iron hydroxide, nickel hydroxide, zirconium hydroxide, titanium hydroxide, zinc hydroxide, copper hydroxide, vanadium hydroxide, tin hydroxide, etc. The metal hydroxides may be used alone or in combination of two or more.

[0051] The content of the metal hydroxide is, for example, 0.1 to 50 parts by mass, preferably 0.2 to 30 parts by mass, more preferably 0.3 to 20 parts by mass, and even more preferably 0.5 to 15 parts by mass, relative to 100 parts by mass of the polyol. By setting the content of the metal hydroxide to be equal to or greater than these lower limits, the effect of the metal hydroxide is easily exerted, and flame retardancy is improved. On the other hand, by setting the content to be equal to or less than the upper limits, foaming is not inhibited by the metal hydroxide.

[0052] <Needle filler> Examples of needle-like fillers include potassium titanate whiskers, aluminum borate whiskers, magnesium-containing whiskers, silicon-containing whiskers, wollastonite, sepiolite, zonolite, elestadite, boehmite, rod-shaped hydroxyapatite, glass fibers, carbon fibers, graphite fibers, metal fibers, slag fibers, gypsum fibers, silica fibers, alumina fibers, silica-alumina fibers, zirconia fibers, boron nitride fibers, boron fibers, and stainless steel fibers. These needle-like fillers can be used alone or in combination of two or more.

[0053] The aspect ratio (length / diameter) of the needle-like filler used in the present invention is preferably in the range of 5 to 50, more preferably in the range of 10 to 40. The aspect ratio can be determined by observing the needle-like filler with a scanning electron microscope and measuring its length and width.

[0054] The content of the needle-like filler is, for example, 10 to 100 parts by mass, preferably 20 to 90 parts by mass, more preferably 30 to 80 parts by mass, and even more preferably 40 to 70 parts by mass, relative to 100 parts by mass of the polyol. By setting the content of the needle-like filler at or above these lower limits, the polyurethane foam is more likely to retain its shape after combustion, improving flame retardancy. On the other hand, by setting the content at or below these upper limits, foaming is less likely to be inhibited by the needle-like filler.

[0055] Of the above-mentioned solid flame retardants, the solid flame retardant is preferably selected from red phosphorus-based flame retardants, boron-containing flame retardants, bromine-containing flame retardants, and needle fillers, and more preferably selected from red phosphorus-based flame retardants, boron-containing flame retardants, and bromine-containing flame retardants. Among these, the solid flame retardant preferably contains a boron-containing flame retardant. When a boron-containing flame retardant is present together with a catalyst in a liquid formulation, it tends to particularly accelerate deterioration of the liquid formulation. However, in the present invention, by separating the liquid formulation A1 (or A) containing the filler from the liquid formulation B containing the catalyst, it is possible to prevent the boron-containing flame retardant from accelerating deterioration of the liquid formulation.

[0056] In addition, two or more solid flame retardants may be used in combination. For example, it is preferable to use two or more solid flame retardants selected from a red phosphorus-based flame retardant, a boron-containing flame retardant, a bromine-containing flame retardant, and a needle filler in combination. It is also preferable to use two or more solid flame retardants selected from a red phosphorus-based flame retardant, a boron-containing flame retardant, and a bromine-containing flame retardant in combination. Specifically, it is also preferable to use a red phosphorus-based flame retardant, a boron-containing flame retardant, and a bromine-containing flame retardant in combination, or a red phosphorus-based flame retardant, a boron-containing flame retardant, a bromine-containing flame retardant, and a needle-like filler in combination. By using two or more solid flame retardants in combination in this way, the flame retardancy can be further improved.

[0057] The content of the solid flame retardant is not particularly limited, but is, for example, 10 to 200 parts by mass, preferably 20 to 150 parts by mass, and more preferably 40 to 120 parts by mass relative to 100 parts by mass of the polyol. By setting the content of the solid flame retardant to at least these lower limits, it is possible to impart appropriate flame retardancy to the polyurethane foam. Furthermore, by setting the content of the solid flame retardant to at most these upper limits, it is possible to prevent the viscosity of the polyol solution or Solution A1 (or Solution A) from becoming too high, making it suitable for use in spraying and filling applications.

[0058] (Anti-settling agent) The polyol liquid of the present invention may contain an anti-settling agent as a filler. That is, in the first method, the liquid A1 may contain the anti-settling agent, and in the second method, the liquid A may contain the anti-settling agent. The anti-settling agent may be used in liquid A1 or liquid A in combination with the solid flame retardant described above or other inorganic fillers described below, but is preferably used in combination with the solid flame retardant. The use of an anti-settling agent can prevent the solid flame retardant and other inorganic fillers described below from settling in Solution A1, Solution A, or the polyol solution, and also makes it easier to uniformly disperse the solid flame retardant and other inorganic fillers described below in the solution.

[0059] The anti-settling agent is not particularly limited, but it is preferable to use one or more selected from, for example, carbon black, powdered silica, organic clay, etc., and among these, powdered silica is more preferable. The carbon black used in the anti-settling agent can be produced by a furnace method, a channel method, a thermal method, etc. Commercially available carbon black may be appropriately selected and used. As the powdered silica, fumed silica, colloidal silica, silica gel, etc. can be used. Among these, fumed silica is preferred, and hydrophobic fumed silica is particularly preferred. As the fumed silica, Aerosil (registered trademark) from Nippon Aerosil Co., Ltd. can be used.

[0060] The content of the anti-settling agent is not particularly limited, but is, for example, 0.5 to 20 parts by mass, preferably 0.7 to 12 parts by mass, and more preferably 1.1 to 8 parts by mass relative to 100 parts by mass of the solid flame retardant. By setting the content of the anti-settling agent within the above range, it is possible to prevent the settling of fillers other than the anti-settling agent, such as the solid flame retardant, without increasing the solid content more than necessary, thereby improving the dispersibility of fillers such as the solid flame retardant.

[0061] As the filler, inorganic fillers (other inorganic fillers) other than the flame retardants and anti-settling agents described above may be used. Examples of inorganic fillers that can be used include alumina, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, ferrites, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dawsonite, hydrotalcite, calcium sulfate, barium sulfate, calcium silicate, talc, mica, montmorillonite, bentonite, activated clay, imogolite, sericite, glass beads, aluminum nitride, boron nitride, silicon nitride, various metal powders, magnesium sulfate, lead zirconate titanate, molybdenum sulfide, silicon carbide, various magnetic powders, and fly ash. These inorganic fillers may be used alone or in combination of two or more.

[0062] The content of the filler in the polyol liquid is, for example, 10 to 300 parts by mass, preferably 20 to 150 parts by mass, and more preferably 45 to 120 parts by mass, relative to 100 parts by mass of the polyol. By setting the content of the filler at or above these lower limits, it becomes easier to impart functions to the polyurethane foam according to the type of filler. In addition, it becomes easier to adjust the viscosity of the polyol liquid to a predetermined range described below.

[0063] [Liquid flame retardant] In each of the first and second methods, the polyol liquid preferably further contains a liquid flame retardant. The liquid flame retardant is a flame retardant that is liquid at room temperature (23°C) and normal pressure (1 atmosphere). Specific examples of liquid flame retardants include phosphate esters. By including a liquid flame retardant, flame retardancy can be further improved.

[0064] In the first method, the liquid flame retardant may be contained in at least one of liquid agent A1, liquid agent A2, and liquid agent B, and is preferably contained in at least one of liquid agent A1 and liquid agent B. In this case, in the first method, the liquid flame retardant may be contained only in liquid agent A1, or only in liquid agent B, or may be contained in both liquid agent A1 and liquid agent B. In addition, in the first method, it is more preferable that the liquid flame retardant be contained in liquid agent A1. In the second method, the liquid flame retardant may be contained in at least one of liquid agent A and liquid agent B. In this case, the liquid flame retardant may be contained only in liquid agent A, only in liquid agent B, or both in liquid agents A and B. In the second method, the liquid flame retardant is preferably contained in liquid agent A.

[0065] In the first and second methods, when the liquid agent A1 or the liquid agent A containing a filler further contains a liquid flame retardant, the filler can be easily dispersed in the liquid agents A1 and A, improving the handleability of the liquid agents A1 and A. Furthermore, when the liquid flame retardant is contained in the liquid agent B containing a catalyst, the catalyst can be easily dissolved or dispersed in the liquid agent B, improving the handleability of the liquid agent B.

[0066] The phosphate ester is preferably a monophosphate ester, a condensed phosphate ester, etc. Examples of the monophosphate ester include trialkyl phosphates such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, and tri(2-ethylhexyl)phosphate, halogen-containing phosphate esters such as tris(β-chloropropyl)phosphate, trialkoxyphosphates such as tributoxyethyl phosphate, aromatic ring-containing phosphate esters such as tricresyl phosphate, trixylenyl phosphate, tris(isopropylphenyl)phosphate, cresyl diphenyl phosphate, and diphenyl(2-ethylhexyl)phosphate, and acidic phosphate esters such as monoisodecyl phosphate and diisodecyl phosphate.

[0067] Examples of the condensed phosphate ester include aromatic condensed phosphate esters such as trialkyl polyphosphate, resorcinol polyphenyl phosphate, bisphenol A polycresyl phosphate, and bisphenol A polyphenyl phosphate. Commercially available condensed phosphate esters include, for example, "CR-733S," "CR-741," and "CR747" manufactured by Daihachi Chemical Industry Co., Ltd., and "ADEKA STAB PFR" and "FP-600" manufactured by ADEKA Corporation.

[0068] The liquid flame retardant may be one of the above-mentioned compounds, or two or more of them may be used in combination. Among these, from the viewpoint of facilitating the production of polyurethane foam and improving the flame retardancy of the polyurethane foam, monophosphate ester is preferred, and tris(β-chloropropyl)phosphate is more preferred.

[0069] When a liquid flame retardant is contained, the content of the liquid flame retardant in the polyol liquid is preferably 5 to 90 parts by mass, more preferably 15 to 80 parts by mass, and even more preferably 25 to 70 parts by mass, per 100 parts by mass of polyol. By setting the content of the liquid flame retardant at or above these lower limits, the effect of containing the liquid flame retardant is easily exerted. Furthermore, by setting the content at or below the upper limits, the liquid flame retardant does not inhibit the foaming of the polyurethane foam.

[0070] [Foaming agent] The polyol liquid agent contains a blowing agent, which can foam the mixture obtained by mixing the polyol liquid agent and the isocyanate liquid agent to form a polyurethane foam. In the first method, the blowing agent is contained in liquid A2. In the first method, the blowing agent is contained in liquid A2 separate from liquids A1 and B, which contain the filler and catalyst, respectively, thereby preventing the blowing agent from affecting the catalyst and promoting its deterioration. Furthermore, by not adding a blowing agent, a decrease in the viscosity of liquid A1 containing the filler can be suppressed, and settling of the filler during storage can be suppressed. In the second method, the blowing agent is contained in liquid agent A. In the second method, the blowing agent is contained together with the filler in liquid agent A that is separate from liquid agent B that contains the catalyst, thereby preventing the blowing agent from affecting the catalyst and promoting deterioration of the liquid agent.

[0071] Examples of the blowing agent include organic blowing agents, such as hydrocarbon compounds, chlorinated aliphatic hydrocarbon compounds, hydrofluorocarbon compounds, hydrofluoroolefin compounds, and other organic fluorine compounds. The blowing agents may be used alone or in combination of two or more. Among these, from the viewpoint of foaming property, organic fluorine compounds are preferred, and from the viewpoint of environmental protection, hydrofluoroolefin compounds are more preferred because of their low global warming potential. Hydrofluoroolefin compounds may be used alone as a foaming agent, or may be used in combination with other foaming agents. Note that, when a hydrofluoroolefin compound is used together with a catalyst, deterioration tends to progress, but in the present invention, by containing the foaming agent and the catalyst in separate liquid agents in step 1, such deterioration can be effectively prevented.

[0072] Examples of hydrocarbon compounds include propane, butane, pentane, hexane, heptane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, and cycloheptane. Examples of chlorinated aliphatic hydrocarbon compounds include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride.

[0073] Examples of hydrofluorocarbon compounds include hydrofluorocarbons such as CHF3, CH2F2, and CH3F, and hydrochlorofluorocarbons such as dichloromonofluoroethane (for example, HCFC141b (1,1-dichloro-1-fluoroethane), HCFC22 (chlorodifluoromethane), and HCFC142b (1-chloro-1,1-difluoroethane)), HFC-245fa (1,1,1,3,3-pentafluoropropane), and HFC-365mfc (1,1,1,3,3-pentafluorobutane).

[0074] Examples of hydrofluoroolefin compounds include fluoroalkenes having 3 to 6 carbon atoms. The hydrofluoroolefins may also be hydrochlorofluoroolefins having chlorine atoms, and therefore may be chlorofluoroalkenes having 3 to 6 carbon atoms. Hydrofluoroolefins having 3 or 4 carbon atoms are preferred. More specific examples include trifluoropropene, tetrafluoropropenes such as HFO-1234, pentafluoropropenes such as HFO-1225, chlorotrifluoropropenes such as HFO-1233, chlorodifluoropropene, chlorotrifluoropropene, and chlorotetrafluoropropene. More specifically, 1,3,3,3-tetrafluoropropene (HFO-1234ze), 1,1,3,3-tetrafluoropropene, 1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,1,1-trifluoropropene, 1,1,1,3,3-pentafluoropropene (HFO-1225zc), 1,1,1,3,3,3-hexafluorobut-2-ene, 1,1,2,3,3-pentafluoropropene (HFO-1225yc), 1,1,1,2,3-pentafluoropropene (HFO-1225yez), (E)-1-chloro-3,3,3-trifluoropropene (HFO-1233zd(E)), Examples include (Z)-1-chloro-3,3,3-trifluoropropene (HFO-1233zd(Z)), (Z)-1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzz(Z)), (E)-1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzz(E)), 2,3,3,3-tetrafluoropropene (HFO-1234yf), trifluoroethylene (HFO-1123), (E)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)), and (Z)-2,3,3,3-tetrafluoro-1-chloropropene (HCFO-1224yd(Z)). Among these, HFO-1233zd(E) is particularly preferred. The foaming agents may be used alone or in combination of two or more.

[0075] The content of the blowing agent in the polyol liquid is preferably 10 to 100 parts by mass, more preferably 20 to 80 parts by mass, and even more preferably 25 to 70 parts by mass, per 100 parts by mass of polyol. When the content of the blowing agent is equal to or greater than these lower limits, foaming is promoted, and the density of the resulting polyurethane foam can be reduced. In addition, the effect of suppressing deterioration of the polyurethane foam can be more easily exerted. On the other hand, when the content of the blowing agent is equal to or less than the upper limit, excessive foaming can be suppressed. In addition to the organic blowing agents described above, the polyurethane foam may be foamed using inorganic blowing agents such as nitrogen gas, oxygen gas, argon gas, carbon dioxide gas, etc. The inorganic blowing agent may be added to the polyol liquid separately from the liquid agents A1, A2, A, and B, or may be added to a mixture of the polyol liquid and the polyisocyanate liquid.

[0076] [water] The polyol liquid may contain water. The inclusion of water improves the foaming properties when forming a polyurethane foam. In the first method, water may be contained in either liquid A1 or A2, but is preferably contained in liquid A1. In the second method, water is contained in liquid A. By containing water in liquid A1 or liquid A, deterioration of the catalyst due to hydrolysis or the like can be suppressed. The water content in the polyol liquid is, for example, 0.1 to 10 parts by mass, preferably 0.2 to 5 parts by mass, and more preferably 0.3 to 3 parts by mass, relative to 100 parts by mass of polyol. By setting the water content within this range, the mixed liquid obtained by mixing the polyol liquid and the isocyanate liquid tends to foam appropriately.

[0077] [Foam stabilizer] The polyol liquid may contain a foam stabilizer. The foam stabilizer improves the foamability of the mixture obtained by mixing the polyol liquid and the isocyanate liquid. In the first method, the foam stabilizer may be contained in any of the liquids A1, A2, and B, but is preferably contained in the liquid A1. In the second method, the foam stabilizer may be contained in any of the liquids A and B, but is preferably contained in the liquid A. Examples of the foam stabilizer include surfactants such as polyoxyalkylene-based foam stabilizers such as polyoxyalkylene alkyl ethers, and silicone-based foam stabilizers such as organopolysiloxanes. These foam stabilizers may be used alone or in combination of two or more. The content of the foam stabilizer in the polyol liquid is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and even more preferably 1 to 5 parts by mass, per 100 parts by mass of polyol. When the content of the foam stabilizer is equal to or greater than these lower limits, the mixed liquid of the polyol liquid and the isocyanate liquid is easily foamed, making it easier to obtain a homogeneous polyurethane foam. Furthermore, when the content of the foam stabilizer is equal to or less than these upper limits, a good balance between production costs and the obtained effects is achieved.

[0078] [Other ingredients] The polyol liquid may contain one or more additives selected from phenolic, amine, sulfur-based and other antioxidants, heat stabilizers, metal inhibitors, antistatic agents, stabilizers, crosslinking agents, lubricants, softeners, pigments, tackifying resins, tackifiers such as polybutene and petroleum resins, etc., as needed, within the scope of the present invention. In the first method, the other components may be contained in any of the solutions A1, A2, and B, but are preferably contained in solution A1. In the second method, the other components may be contained in either solution A or B, but are preferably contained in solution A.

[0079] (Viscosity of polyol liquid) The viscosity of the polyol liquid at 25°C and 60 rpm is preferably 200 to 2500 mPa·s. By having the viscosity within the above range, the polyol liquid can be efficiently impingement-mixed with the isocyanate liquid while preventing the filler from settling in the polyol liquid. From these perspectives, the viscosity of the polyol liquid at 25°C and 60 rpm is more preferably 500 to 2000 mPa·s. The viscosity of the polyol liquid is measured in detail by the method described in the Examples below.

[0080] [Liquid A1, A2, A] As described above, the liquid agent A1 in the first method only needs to contain a filler, and preferably contains at least one of a polyol and a liquid flame retardant in addition to the filler, and preferably contains both a polyol and a liquid flame retardant. When the liquid agent A1 contains at least one of a polyol and a liquid flame retardant, the filler can be easily dispersed in the liquid agent A1, and the handleability of the liquid agent A1 is improved. From the same viewpoint, the liquid agent A in the second method preferably contains at least one of a polyol and a liquid flame retardant, and preferably contains both a polyol and a liquid flame retardant. Furthermore, liquid agent A1 may contain components other than polyol and liquid flame retardant, for example, a foam stabilizer, water, and at least one selected from the other components described above. Similarly, in the second method, liquid agent A may contain components other than polyol and liquid flame retardant, for example, a foam stabilizer, water, and at least one selected from the other components described above. Furthermore, although the liquid agent A2 contains a foaming agent, it may also contain other components as appropriate.

[0081] However, in the first method, it is preferable that the liquid agents A1 and A2 are substantially free of a catalyst. When the liquid agent A1 is substantially free of a catalyst, deterioration of the liquid agent A1 during storage, etc., due to the coexistence of a catalyst and a filler, can be effectively prevented. Furthermore, when the liquid agent A2 is substantially free of a catalyst, deterioration of the liquid agent A1 due to the coexistence of a catalyst and a blowing agent can be effectively prevented. From the same viewpoint, in the second method, it is preferable that the liquid agent A contains substantially no catalyst. Note that "substantially free of catalyst" means that a small amount of catalyst may be blended into the liquid formulations A1, A2, and A as long as the effect of the present invention is not impaired; specifically, the catalyst content in each liquid formulation is, for example, less than 1 mass %, preferably less than 0.5 mass %, more preferably less than 0.1 mass %, and most preferably 0 mass %, based on the total amount of the liquid formulation (liquid formulations A1, A, or A2).

[0082] Furthermore, in the first method, it is preferable that the liquid agent A1 is substantially free of a foaming agent. The phrase "liquid agent A1 is substantially free of a foaming agent" means that a small amount of foaming agent may be blended into the liquid agent A1 to the extent that it does not affect the effect. Specifically, the content of the foaming agent in the liquid agent A1 is, for example, less than 2% by mass, preferably less than 1% by mass, more preferably less than 0.3% by mass, and most preferably 0% by mass, based on the total amount of the liquid agent A1. By substantially not containing a foaming agent, the viscosity of the liquid agent A1 can be easily increased, as described below. Similarly, in the first method, it is preferable that Liquid A2 contains substantially no filler. Liquid A2 containing substantially no filler means that a small amount of filler may be blended into Liquid A2 to the extent that it does not affect the effect. Specifically, the content of filler in Liquid A2 is, for example, less than 2% by mass, preferably less than 1% by mass, more preferably less than 0.3% by mass, and most preferably 0% by mass, based on the total amount of Liquid A2. By containing substantially no filler in Liquid A2, settling of the filler in Liquid A2 during storage can be prevented.

[0083] (Viscosity of liquid A1) The viscosity of Liquid A1 at 25°C and 1 rpm is preferably 3000 to 60,000 mPa·s. By making the viscosity of Liquid A1 3000 mPa·s or higher, even when Liquid A1 is stored at room temperature or below room temperature (for example, below 30°C), it is possible to prevent the filler from settling and hard caking from occurring. Furthermore, by making the viscosity 60,000 mPa·s or lower, it becomes easier to keep the viscosity of the polyol liquid within the above viscosity range. From these perspectives, the viscosity of Liquid A1 at 25°C and 1 rpm is more preferably 3,500 to 50,000 mPa·s, and even more preferably 4,000 to 40,000 mPa·s. The viscosity of Liquid A1 is measured in detail by the method described in the Examples below.

[0084] [Liquid B] In the first and second methods, liquid agent B contains a catalyst, and it is preferable that the catalyst be dissolved or dispersed in other components in liquid agent B. Therefore, liquid agent B preferably contains other components in addition to the catalyst. Examples of other components in liquid agent B besides the catalyst include organic solvents and liquid components contained in polyol liquid agents, such as polyols, foam stabilizers, and liquid flame retardants. Any type of organic solvent can be used as long as it can dissolve catalysts, but alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol are preferred. Note that these short-chain alcohols (chain alcohols with 6 or fewer carbon atoms) including those having two or more hydroxyl groups are also considered organic solvents in this specification.

[0085] In each of the first and second methods, it is preferable that liquid agent B contains an organic solvent as a component other than the catalyst, from the viewpoint of not affecting the catalyst and from the viewpoint of catalyst solubility, etc. Therefore, the polyol liquid agent may also contain an organic solvent. The content of the organic solvent in the polyol liquid agent is, for example, 0.5 to 25 parts by mass, preferably 1 to 20 parts by mass, per 100 parts by mass of the polyol.

[0086] In the first and second methods, it is preferable that Liquid B is substantially free of both a filler and a blowing agent. By being substantially free of a filler and a blowing agent, deterioration of the liquid can be prevented, which would otherwise occur if a catalyst were to be present together with a filler or a blowing agent. Note that "substantially free of filler" means that a small amount of filler may be blended into Liquid B as long as it does not impair the effects of the present invention; specifically, the filler content in Liquid B is less than 2 mass % based on the total amount of Liquid B, preferably less than 1 mass %, more preferably less than 0.3 mass %, and most preferably 0 mass %. Furthermore, "substantially free of a foaming agent" means that a small amount of foaming agent may be blended into Liquid Agent B as long as the effects of the present invention are not impaired; specifically, the content of the foaming agent in Liquid Agent B is less than 2 mass%, preferably less than 1 mass%, more preferably less than 0.3 mass%, and most preferably 0 mass%, based on the total amount of Liquid Agent B.

[0087] As described above, in the first and second methods, multiple liquids are mixed to obtain a polyol liquid in step 2, but in the first method, it is preferable to mix the multiple liquids so that the mass ratio of liquid A1 containing a filler is higher than the mass ratios of the other liquids (liquid A2, liquid B). By increasing the mass ratio of liquid A1, the filler in liquid A1 becomes more easily dispersed by components other than the filler (e.g., polyol, liquid flame retardant), and when preparing the polyol liquid, it becomes easier to uniformly disperse the filler in the polyol liquid. From a similar viewpoint, in the second method, in step 2, it is preferable to mix liquid A and liquid B so that the mass ratio of liquid A containing the filler is higher than the mass ratio of the other liquid (liquid B) to obtain a polyol liquid.

[0088] In the first method, the mass ratio of Liquid A1 is preferably 50 to 95 mass% based on the total amount of the polyol liquid. By making it 50 mass% or more, the filler can be easily dispersed in Liquid A1 by the components other than the filler. Furthermore, by making it 95 mass% or less, the amounts of Liquids A2 and B can be kept at a certain level or more. From these viewpoints, the mass ratio of Liquid A1 is more preferably 60 to 90 mass%, and even more preferably 65 to 84 mass%. In the first method, the mass ratio of Liquid B is preferably 1 to 45 mass% based on the total amount of the polyol liquid. By making it 1 mass% or more, the catalyst amount can be kept appropriate, and the catalyst can be easily dissolved or dispersed in other components in Liquid B. Furthermore, by making it 45 mass% or less, the amounts of Liquids A1 and A2 can be kept at a certain amount or more. From these perspectives, the mass ratio of Liquid B is more preferably 2 to 32 mass%, and even more preferably 5 to 25 mass%. In the first method, the mass ratio of Liquid A2 is preferably 4 to 49 mass% based on the total amount of the polyol liquid. By setting it to 4 mass% or more, it becomes possible to contain an appropriate amount of blowing agent in the polyol liquid. Furthermore, by setting it to 49 mass% or less, it becomes possible to maintain the amounts of Liquids A1 and B at a certain level or more. From these viewpoints, the mass ratio of Liquid A2 is more preferably 8 to 38 mass%, and even more preferably 10 to 30 mass%.

[0089] In the second method, the mass ratio of Liquid A is preferably 55 to 99 mass% based on the total amount of the polyol liquid. By making it 55 mass% or more, it becomes possible to disperse the filler in Liquid A by components other than the filler. Furthermore, by making it 99 mass% or less, it becomes possible to make the amount of Liquid B a certain amount or more. From these viewpoints, the mass ratio of Liquid A is more preferably 65 to 98 mass%, and even more preferably 75 to 97 mass%. In the second method, the mass ratio of Liquid B is preferably 1 to 45 mass% based on the total amount of the polyol liquid. By setting it to 1 mass% or more, it becomes possible to dissolve or disperse the catalyst in other components in Liquid B while maintaining an appropriate amount of catalyst. Furthermore, by setting it to 45 mass% or less, it becomes possible to maintain the amount of Liquid A at a certain amount or more. From these viewpoints, the mass ratio of Liquid B is more preferably 2 to 35 mass%, and even more preferably 5 to 25 mass%.

[0090] In the liquid preparation A1 of the first method, the filler content, i.e., the solid content concentration, is preferably 10 to 50% by mass. By making the content 10% by mass or more, the filler can effectively impart various functions. Furthermore, by making the content 50% by mass or less, the filler can be easily dispersed appropriately in the liquid preparation A1. From the above viewpoints, the range is more preferably 15 to 45% by mass, and even more preferably 20 to 40% by mass. Similarly, in the liquid agent A of the second method, the filler content, ie, the solid content, is preferably 5 to 45 mass %, more preferably 10 to 40 mass %, and even more preferably 15 to 35 mass %.

[0091] The polyol liquid contains polyol, filler, blowing agent, and catalyst as essential components, and in the first method, these essential components are preferably blended into liquids A1, A2, and B according to patterns 1 to 3 shown in Table 1. Similarly, in the second method, these essential components are preferably blended into liquids A and B according to patterns 4 to 6 shown in Table 1.

[0092] [Table 1]

[0093] Table 1 indicates whether each component is contained in either Solution A1, A2, or B, or Solution A or B. "A1 / B" indicates that the component is contained in both Solution A1 and Solution B. "A / B" indicates that the component is contained in both Solution A and Solution B. The same applies to Table 2 and subsequent tables. Of course, in each of the above patterns, each of the liquid agents A1, A2, B, and A may contain a liquid flame retardant, a foam stabilizer, water, and other components as appropriate, as described above.

[0094] Furthermore, the polyol liquid preferably contains a liquid flame retardant as described above. When the polyol liquid contains a liquid flame retardant in addition to the polyol, filler, blowing agent, and catalyst, these components are preferably blended into liquids A1, A2, and B in the first method as shown in patterns 1X to 6X in Table 2 below. Similarly, in the second method, these components are preferably blended into liquids A and B in the patterns 7X to 12X in Table 2 below.

[0095] [Table 2]

[0096] Patterns 1X to 12X are examples of the formulation of each liquid, and any of the liquids may contain ingredients other than those listed in Table 2 (for example, water, foam stabilizer, other ingredients, etc.). For example, the polyol solution may contain water and a foam stabilizer. In this case, the water and the foam stabilizer may be blended independently into any of the solutions, but in the first method, they are preferably blended into Solution A1 as shown in patterns 1Y to 6Y in Table 3 below. Similarly, in the second method, they are preferably blended into Solution A as shown in patterns 7Y to 12Y in Table 3 below. In each pattern, Solution B may contain an organic solvent. Table 3 shows the formulations for the polyol liquid containing a liquid flame retardant, water, and a foam stabilizer in addition to the polyol, filler, blowing agent, and catalyst, but each liquid may contain other components. For example, in each pattern, liquid B may contain an organic solvent.

[0097] [Table 3]

[0098] <Isocyanate liquid> In the first and second methods, the isocyanate liquid contains a polyisocyanate. As the polyisocyanate, a known polyisocyanate used in molding polyurethane foams can be used, such as an aromatic polyisocyanate, an alicyclic polyisocyanate, and an aliphatic polyisocyanate.

[0099] Examples of aromatic polyisocyanates include phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, and polymethylene polyphenyl polyisocyanate.

[0100] Examples of alicyclic polyisocyanates include cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and dimethyldicyclohexylmethane diisocyanate. Examples of the aliphatic polyisocyanate include methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate.

[0101] Among these, from the viewpoints of ease of use and availability, aromatic polyisocyanates are preferred, and diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, and the like are more preferred. The polyisocyanate may be used alone or in combination of two or more kinds.

[0102] (Isocyanate Index) The isocyanate liquid agent of the present invention is preferably mixed with the polyol liquid agent so that the mixed liquid obtained by mixing the polyol liquid agent and the isocyanate liquid agent has an isocyanate index of preferably 250 to 600, more preferably 300 to 550. If the isocyanate index is equal to or greater than the above-mentioned lower limit, the amount of polyisocyanate relative to the polyol becomes excessive, which facilitates the formation of isocyanurate bonds due to the trimerization of the polyisocyanate, thereby improving the flame retardancy of the polyurethane foam. On the other hand, if the isocyanate index is equal to or less than the above-mentioned upper limit, the friability of the resulting polyurethane foam will be good. The isocyanate liquid may be composed of polyisocyanate alone, but may also contain additives that are conventionally added to isocyanate liquids.

[0103] The isocyanate index can be calculated by the following method. Isocyanate index = polyisocyanate equivalents ÷ (polyol equivalents + water equivalents) × 100 Here, each equivalent number can be calculated as follows: Equivalent weight of polyisocyanate = Amount of polyisocyanate used (g) × NCO content (mass%) / Molecular weight of NCO (mol) × 100 Equivalent weight of polyol = OHV × amount of polyol used (g) ÷ molecular weight of KOH (mmol) OHV is the hydroxyl value of the polyol (mg KOH / g). Equivalents of water = Amount of water used (g) / Molecular weight of water (moles) × Number of OH groups in water In the above formulas, the molecular weight of NCO is 42 (mol), the molecular weight of KOH is 56,100 (mmol), the molecular weight of water is 18 (mol), and the number of OH groups in water is 2.

[0104] Next, each step of the method for producing a polyurethane foam of the present invention will be described in detail with reference to Fig. 1. Note that Fig. 1 is a diagram for explaining the first and second methods together, and liquid agent A2 is not used in the second method. [Process 1] In the first method, in step 1, liquids A1, A2, and B are prepared. In the second method, liquids A and B are prepared. In step 1, liquids A1, A2, A, and B may be prepared by filling components 10 constituting each liquid into a known container 11. Examples of containers 11 include known containers for storing urethane raw materials. Examples of containers include, but are not limited to, drums, 18L cans, gallon cans, pails, glass containers, and tanks.

[0105] The method for preparing each liquid formulation in step 1 is not particularly limited, but when the liquid formulation contains two or more components, the components may be added and mixed by stirring, etc. The components may be added directly to container 11 and mixed in container 11 to prepare liquid formulations A1, A2, A, and B, or the components may be mixed in advance in a mixer (not shown) to prepare liquid formulations A1, A2, A, and B, and the prepared liquid formulations A1, A2, A, and B may then be filled into container 11. In this case, among the components, the catalyst may be added in a state diluted with a small amount of polyol, organic solvent, etc. Alternatively, the catalyst may be diluted with a small amount of polyol, organic solvent, etc. and used as liquid agent B as is.

[0106] The liquid preparations A1, A2, B, and A prepared in step 1 may be stored, transported, delivered, etc. in a state filled in a container 11. The storage time varies appropriately depending on the mode of use, but may be, for example, from one hour to two years, from 24 hours to one year, or from 24 hours to six months. The storage temperature is not particularly limited, but may be, for example, about 0 to 40°C, preferably about 5 to 30°C. The storage time refers to the time from when the liquid preparations A1, A2, B, and A are prepared until they are started to be mixed with other liquid preparations in step 2.

[0107] [Process 2] In the first method, liquids A1, A2, and B prepared in step 1 are mixed in step 2 to obtain polyol liquid P. In the second method, liquids A and B are mixed in step 2 to obtain polyol liquid P. As shown in FIG. 1, the liquids may be mixed by transferring liquids A1, A2, and B or liquids A and B from container 11 to mixer 12 and mixing the liquids together by appropriate stirring within mixer 12. Alternatively, although not shown, predetermined amounts of liquids A2 and B may be measured and added to container 11 for liquid A1, or liquid B may be added to container 11 for liquid A, and the liquids may be mixed in container 11 to obtain polyol liquid P. Furthermore, liquids A1, A2, and B or liquids A and B may be transferred to another container and mixed there. As a specific example of a mixing method, stirring may be performed by rotating blades in a container or in the mixer 12, or a stirrer such as a static mixer that mixes by utilizing the momentum of the liquid being fed may be used. The liquid preparations may be mixed in the mixer 12 at a temperature of, for example, 5 to 30°C, and preferably at a temperature of 10 to 25°C. The polyol liquid P obtained in step 2 may be transferred from the container 11 or the mixer 12 to a container and then sent to the mixing and discharging device 13 described later via the container, or the polyol liquid P obtained in the mixer 12 may be sent directly to the mixing and discharging device 13 without going through a container or the like.

[0108] [Process 3] In both the first and second methods, in step 3, the polyol liquid P obtained in step 2 is mixed with the isocyanate liquid IS, and the resulting mixture is used to obtain a polyurethane foam. The mixture is preferably discharged, reacted, and foamed to obtain a polyurethane foam. In step 2, the polyol liquid agent P and the isocyanate liquid agent IS may be mixed after adjusting the temperature to, for example, 10 to 60°C, and preferably 15 to 50°C.

[0109] Step 3 may be performed in a known mixing and discharging device 13, and the polyol liquid P and the isocyanate liquid IS may be mixed, for example, by collision inside the mixing and discharging device 13, and the mixed liquid may be discharged from the discharge port of the mixing and discharging device 13. To cause mixing and collision, the polyol liquid P and the isocyanate liquid IS may be transported, for example, in a pressurized state through a pipe and collided in a mixing section (not shown), or they may be mixed and discharged by other methods. Other mixing and discharging methods include those using a static mixer or an impeller.

[0110] The mixture discharged from the discharge port undergoes a reaction (for example, resinification and trimerization) in the presence of a catalyst, and is foamed by a foaming agent, thereby forming a polyurethane foam. The mixing and discharging device 13 is not particularly limited as long as it can mix and discharge the polyol liquid and the isocyanate liquid, and a spray gun or the like can be used. In the above explanation, the mixer 12 used in step 2 and the mixing and discharging device 13 used in step 3 are described as separate devices, but they may also be integrated into one device. Furthermore, in step 3, it is not necessarily required to discharge the mixture. After mixing with a propeller, the propeller may be moved to separate the mixture, and then the mixture may be foamed.

[0111] The first and second methods can be applied to, for example, spraying applications. Therefore, the mixed liquid discharged from the mixing and discharging device 13 is sprayed onto a target surface at a certain discharge pressure and foamed, thereby forming a polyurethane foam on the target surface. The target surface is not particularly limited, but examples thereof include the wall, ceiling, and floor surfaces of a building. The first and second methods can also be applied to filling applications. The mixed liquid discharged from the mixing and discharging device 13 may be injected into a structure having a cavity therein, such as a mold or a frame, and foamed and cured inside the structure to form a polyurethane foam.

[0112] As described above, the first and second methods of the present invention involve preparing a polyol liquid in step 2, and then mixing the polyol liquid with an isocyanate liquid in step 3 to obtain a polyurethane foam, but it is preferable to mix the polyol liquid with the isocyanate liquid promptly after preparing the polyol liquid. By mixing the polyol liquid with the isocyanate liquid promptly after preparing the polyol liquid, deterioration of the liquid can be more effectively prevented. Specifically, the interval time from obtaining the polyol liquid to starting mixing the polyol liquid and the isocyanate liquid may be, for example, 20 days or less, preferably 10 days or less, and more preferably 5 days or less. The shorter the interval time, the better, and is not particularly limited, but is, for example, 1 second or more, and practically, for example, 1 minute or more. In the first method, the interval time refers to the time from when liquid agents A1, A2, and B are mixed to obtain a polyol liquid agent until the start of mixing the polyol liquid agent and the isocyanate liquid agent. In the second method, the interval time refers to the time from when liquid agents A and B are mixed to obtain a polyol liquid agent until the start of mixing the polyol liquid agent and the isocyanate liquid agent. During the interval, the polyol liquid may be kept at a constant temperature of, for example, 0 to 35°C, preferably about 5 to 25°C. [Example]

[0113] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0114] Examples 1 to 5 The components were mixed as needed according to Table 4 to prepare solutions A1, A2, and B, which were then filled into metal pressure-resistant 18L cans. The solutions A1, A2, and B filled into the 18L cans were left at 25°C for 10 minutes after preparation. Next, solutions A1, A2, and B were transferred to metal pails in the appropriate amounts and mixed using a drill stirrer to obtain a polyol solution. An isocyanate solution consisting of polyisocyanate (Sumitomo Chemical Co., Ltd., "Sumidur 44V20") was also prepared, sealed in a 18L can. The polyol liquid and the isocyanate liquid consisting of polyisocyanate were each placed in an ice-water bath to adjust the temperature to 15°C. After adjusting the temperature, 100g of the polyol liquid was immediately added to a 500ml PP cup, followed by 100g of the isocyanate liquid, which was then gently added. After addition, the mixture was quickly stirred for 2 seconds using a stirrer (Homodisper, manufactured by Primix Corporation) rotating at 8000 rpm. The time when stirring began was defined as 0 seconds, and the time when the foam that had begun to foam was poked with a thin rod and a string formed when the rod was released was defined as the gel time (T1).

[0115] (Deterioration measurement) Instead of leaving the prepared solutions A1, A2, and B at 25°C for 10 minutes after preparation, they were left in a 40°C environment for 2 weeks after preparation to accelerate degradation. After that, they were returned to room temperature and opened. Solution A1 was redispersed by stirring, and the same procedure as above was repeated to measure the gel time (T2). The degradation of the solutions was indirectly evaluated based on the difference between the gel time (T1) before accelerated degradation and the gel time (T2) after accelerated degradation. A: Gel time difference is less than 5 seconds B: Gel time difference is 5 seconds or more and less than 15 seconds C: Gel time difference is 15 seconds or more

[0116] Examples 6 to 10 The components were mixed according to Table 4 to prepare solutions A and B, which were then filled into metal pressure-resistant 18L cans. Solutions A and B filled into the 18L cans were left at room temperature (25°C) for 10 minutes after preparation. Next, solutions A and B were transferred to metal pails in the appropriate amounts and mixed using a drill stirrer to obtain a polyol solution. An isocyanate solution consisting of polyisocyanate (Sumitomo Chemical Co., Ltd., "Sumidur 44V20") was also prepared and sealed in a 18L can. The gel time (T1) was then measured in the same manner as in Example 1. Furthermore, similarly to Example 1, the deterioration of liquids A and B was accelerated, and then the containers were returned to room temperature and opened. Liquid A was redispersed, and the gel time (T2) after the accelerated deterioration was also measured. The deterioration of the liquids was indirectly evaluated based on the difference in gel time according to the above evaluation criteria.

[0117] Comparative Example 1 The components were mixed according to Table 4 to prepare Solution A, which was then filled into a metal pressure-resistant 18L can. The prepared Solution A filled into the metal pressure-resistant 18L can was left at room temperature (25°C) for 10 minutes. Next, Solution A was cooled together with an isocyanate solution as a polyol solution, as in Example 1, and the polyol solution and isocyanate solution were mixed, and the gel time (T1) was measured. Similarly to Example 1, the degradation of Solution A was accelerated, and the gel time (T2) after accelerated degradation was also measured. The difference in gel time was used to indirectly evaluate the degradation of the solution according to the above-mentioned evaluation criteria.

[0118] Comparative Example 2 The same procedure as in Example 6 was carried out except that the formulations of the liquid preparations A and B were changed as shown in Table 4.

[0119] <Viscosity> The viscosity of the liquid preparation A1 in Examples 1 to 5 and the viscosity of the polyol liquid preparations in each Example and Comparative Example were measured as follows. For Solution A1, measurements were taken at a liquid temperature of 25°C using a Brookfield viscometer at 1 rpm, and the value measured one minute after the start of rotation was taken as the viscosity of Solution A. For the polyol solution, measurements were taken at a liquid temperature of 25°C using a Brookfield viscometer at 60 rpm, and the value measured one minute after the start of rotation was taken as the viscosity of the polyol solution.

[0120] The components used in the examples and comparative examples are as follows: The number of parts of each component shown in Table 4 indicates the number of parts of the diluted product (product) in the case of diluted products. (Polyol) Polyester polyol (Kawasaki Chemical Industries, Ltd., product name: Maximol RLK-087, hydroxyl value = 200 mg KOH / g) Polyester polyol (PHANTOL SV-208 manufactured by Hitachi Chemical Co., Ltd., hydroxyl value 235 mg KOH / g) (Foam stabilizer) Silicone foam stabilizer (SH-193, manufactured by Toray Dow Corning Co., Ltd.) (liquid flame retardant) Tris(β-chloropropyl)phosphate (manufactured by Daihachi Chemical Co., Ltd., product name: TMCPP) (catalyst) Trimerization catalyst 1: Potassium carboxylate (a dilution of approximately 75% by mass of active ingredient, manufactured by Evonik Japan Co., Ltd., product name: DABCO K-15) Trimerization catalyst 2: quaternary ammonium carboxylate (diluted with an active ingredient content of 45 to 55% by mass) (Evonik Japan Co., Ltd., product name: DABCO TMR-7) Resinification catalyst: Imidazole compound (Kao Corporation, product name: Kaolizer No. 390, diluted with 65 to 75% active ingredient by mass) (filler) Red phosphorus flame retardant (manufactured by Rinkagaku Kogyo Co., Ltd., product name: Nova Excel 140, metal hydroxide coating, red phosphorus content 94% by mass or more) Zinc borate (Hayakawa Shoji Co., Ltd., product name: Firebrake ZB) Ethylenebis(pentabromophenyl) (Albemarle, product name: SAYTEX 8010) Fumed silica (manufactured by Nippon Aerosil Co., Ltd., product name: Aerosil R976S) (foaming agent) HFO-1233zd(E) (manufactured by Central Glass Co., Ltd., product name: Solstice LBA) [Table 4]

[0121] As shown in Table 4, in Examples 1 to 5, liquid A1 containing a filler, liquid A2 containing a blowing agent, and liquid B containing a catalyst were prepared separately, and then mixed to obtain a polyol liquid.This allowed the production of high-quality polyurethane foams without deterioration even when the deterioration of each of liquids A1, A2, and B was accelerated. Similarly, in Examples 6 to 10, liquid A containing a filler and a blowing agent and liquid B containing a catalyst were prepared separately, and then mixed to obtain a polyol liquid. By using this, even when the deterioration of each of liquids A and B was accelerated, good quality polyurethane foam could be produced without deterioration. In contrast, in Comparative Example 1, the liquids constituting the polyol liquid were not prepared separately, and therefore, when the deterioration of the liquids was accelerated, the liquids deteriorated and a high-quality polyurethane foam could not be produced. Also, in Comparative Example 2, the liquids constituting the polyol liquid were prepared separately as liquids A and B, but while the blowing agent was separated, liquid A contained a catalyst and filler, and therefore, when the deterioration of liquids A and B was accelerated, the deterioration of the liquids progressed and a high-quality polyurethane foam could not be produced. [Explanation of symbols]

[0122] 10 ingredients 11 Container 12 Mixer 13 Mixing and discharging device A, A1, A2, B liquid P Polyol liquid IS Isocyanate Liquid

Claims

1. A step of preparing liquid agent A and liquid agent B; A step of mixing the liquid agent A and the liquid agent B to obtain a polyol liquid agent; and mixing the polyol liquid agent and the isocyanate liquid agent, A method for producing a polyurethane foam, wherein the liquid agent A contains a filler and a blowing agent, the liquid agent B contains a catalyst, and at least one of the liquid agents A and B contains a polyol.

2. A step of preparing liquid agent A1, liquid agent A2, and liquid agent B; A step of mixing the liquid agent A1, the liquid agent A2, and the liquid agent B to obtain a polyol liquid agent; and mixing the polyol liquid agent and the isocyanate liquid agent, A method for producing a polyurethane foam, wherein the liquid agent A1 contains a filler, the liquid agent A2 contains a blowing agent, the liquid agent B contains a catalyst, and at least one of the liquid agents A1, A2, and B contains a polyol.

3. The method for producing a polyurethane foam according to claim 1, wherein the liquid A and the liquid B are mixed so that the mass ratio of the liquid A is higher than that of the liquid B, thereby obtaining a polyol liquid.

4. 3. A method for producing a polyurethane foam according to claim 2, wherein the liquid A1, the liquid B, and the liquid A2 are mixed so that the mass ratio of the liquid A1 is higher than the mass ratios of the liquid B and the liquid A2, respectively, to obtain a polyol liquid.

5. The method for producing a polyurethane foam according to any one of claims 1 to 4, wherein the viscosity of the polyol liquid at 25°C and 60 rpm is 200 to 2500 mPa·s.

6. The method for producing a polyurethane foam according to any one of claims 1 to 5, wherein the blowing agent comprises a hydrofluoroolefin-based compound.

7. 7. The method for producing a polyurethane foam according to any one of claims 1 to 6, wherein the filler comprises a solid flame retardant, and the solid flame retardant is at least one selected from the group consisting of red phosphorus-based flame retardants, boron-containing flame retardants, bromine-containing flame retardants, phosphate-containing flame retardants, chlorine-containing flame retardants, antimony-containing flame retardants, metal hydroxides, and needle-like fillers.

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