Polyol liquid agent, urethane composition, polyurethane foam, and metal frame

Abstract

To provide a polyol liquid agent capable of producing a polyurethane foam having both excellent flame resistance and adhesion inside an elongated hollow part.SOLUTION: A polyol liquid agent containing a polyol, a catalyst, a reaction retarder, and a flame retardant, the catalyst including a trimerization catalyst and a resinification catalyst, the mass ratio of the resinification catalyst content to the trimerization catalyst content being 0.4-1.0.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid polyol, a polyurethane composition containing the liquid polyol, a polyurethane foam formed from the polyurethane composition, and a metal frame filled with the polyurethane foam. [Background technology]

[0002] Urethane foam has excellent functions such as thermal insulation and the ability to fill confined spaces through foaming and self-adhesion, and is therefore widely used in building materials such as panels and flat decks (see, for example, Patent Document 1). However, urethane foam is known to be highly flammable and poses a high fire risk. Therefore, in order to impart flame retardancy to urethane foam, a flame retardant is sometimes blended into the polyurethane composition that forms the urethane foam. It is also known to add a trimerization catalyst to form a nurate structure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-331604 Summary of the Invention [Problem to be solved by the invention]

[0004] However, polyurethane compositions containing flame retardants have the problem of increased viscosity and reduced filling performance. Furthermore, when polyurethane compositions containing a trimerization catalyst and a resinification catalyst are used, two-stage foaming behavior due to the trimerization catalyst and the resinification catalyst can occur when filling a long, narrow hollow space, such as a flat deck. This can result in insufficient uniform adhesion within the long, narrow hollow space, resulting in insufficient filling performance for confined spaces. Therefore, an object of the present invention is to provide a polyol liquid agent capable of forming a polyurethane foam that is both flame retardant and has adhesive properties within a long, narrow hollow portion. [Means for solving the problem]

[0005] The present invention has been made to solve the above problems, and the gist of the present invention is as follows. [1] A polyol liquid comprising a polyol, a catalyst, a reaction retarder, and a flame retardant, wherein the catalyst comprises a trimerization catalyst and a resinification catalyst, and the mass ratio of the content of the resinification catalyst to the content of the trimerization catalyst is 0.4 to 1.0. [2] The polyol liquid according to [1], wherein the reaction retarder comprises at least one selected from a hydroxycarboxylic acid compound and an amine-based acid blocking catalyst. [3] The polyol liquid according to [1] or [2], wherein the polyol comprises at least one selected from polyester polyols and polyether polyols. [4] The polyol liquid according to any one of [1] to [3], further containing a foaming agent. [5] The polyol liquid according to any one of [1] to [4], further containing a foam stabilizer. [6] The polyol liquid according to any one of [1] to [5], further containing a sedimentation inhibitor. [7] A polyurethane composition comprising the liquid polyol agent according to any one of [1] to [6] and the liquid polyisocyanate agent. [8] The polyurethane composition according to [7], having an isocyanate index of 200 to 600. [9] The polyurethane composition according to [7] or [8], wherein the difference between the cream time and the gel time (gel time - cream time) at a liquid temperature of 40°C is 10 to 90 seconds.

[10] A polyurethane foam formed from the polyurethane composition according to [7].

[11] A metal frame having an elongated hollow portion filled with the polyurethane foam described in

[10] .

[12] The metal frame according to

[11] , which is a flat deck having the elongated hollow portion formed by bending a galvanized steel plate. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a polyol liquid that can form a polyurethane foam that is both flame retardant and has adhesive properties within a long, narrow hollow portion. DETAILED DESCRIPTION OF THE INVENTION

[0007] [Polyol liquid] The polyol liquid of the present invention contains a polyol, a reaction retarder, a flame retardant, and a catalyst. The polyol liquid of the present invention is used, for example, to fill a long, narrow hollow portion of a structure with polyurethane foam. More specifically, the polyol liquid is used to fill a hollow portion of a metal frame such as a flat deck by providing an injection port, or to fill a hollow portion of an unfinished metal frame such as a flat deck during its manufacturing stage as part of the manufacturing process (part of the manufacturing line). The hollow portion of the metal frame has a fixed shape, and when the polyurethane composition containing a polyol liquid and a polyisocyanate liquid is filled into the hollow portion, the polyol composition is filled along the inner wall of the hollow portion from near the filling position toward a position away from the filling position, such as the end of the hollow, and foams and hardens to form a polyurethane foam that corresponds to the shape of the hollow portion. The liquid polyol of the present invention exhibits stable foaming behavior and fluidity for a certain period of time even after being mixed with the liquid polyisocyanate, and can be distributed throughout the entire interior of a structure even at positions distant from the filling position, thereby providing excellent filling properties when filled into hollow spaces of a structure together with the liquid polyisocyanate. Therefore, even when flame retardancy is imparted by a flame retardant, uniform and sufficient adhesion can be obtained within elongated hollow spaces, allowing the formation of a polyurethane foam that satisfies filling requirements in confined spaces.

[0008] [Polyol] The polyol contained in the polyol liquid is a compound having two or more hydroxyl groups. As the polyol, any polyol other than the reaction retarder may be used, specifically, any polyol having no carboxyl group may be used. In the present invention, examples of the polyol include polyester polyol, polyether polyol, polylactone polyol, polycarbonate polyol, and polymer polyol. The polyol preferably contains at least one selected from polyester polyol and polyether polyol, and more preferably contains polyester polyol. The polyester polyol is preferably used in an amount of 20 parts by mass or more, more preferably 50 parts by mass or more, even more preferably 80 parts by mass or more, and particularly preferably 100 parts by mass, per 100 parts by mass of the polyol.

[0009] <Polyester polyol> Examples of polyester polyols include aromatic polyester polyols and aliphatic polyester polyols, but considering the flame retardancy of the resulting polyurethane foam, it is preferable to use aromatic polyester polyols. The aromatic polyester polyol is preferably a condensate of an aromatic dicarboxylic acid such as o-phthalic acid (phthalic acid), m-phthalic acid (isophthalic acid), p-phthalic acid (terephthalic acid), or naphthalenedicarboxylic acid with a glycol. Among these, the polyol preferably contains a phthalic acid-based polyester polyol, which is a condensate of phthalic acid and a glycol, and more preferably contains a p-phthalic acid-based polyester polyol, which is a condensate of p-phthalic acid and a glycol. The glycol is not particularly limited, but it is preferable to use low molecular weight aliphatic glycols known as constituent components of polyester polyols, such as ethylene glycol, propylene glycol, and diethylene glycol.

[0010] The content of the aromatic polyester polyol is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 90 parts by mass or more, and still more preferably 100 parts by mass, based on 100 parts by mass of the polyol. As described above, the aromatic polyester polyol is preferably a phthalic acid-based polyester polyol, and therefore, an embodiment in which the content of the phthalic acid-based polyester polyol is within the above range is more preferable.

[0011] <Polyether polyol> Examples of polyether polyols include polyoxyalkylene polyols obtained by ring-opening addition polymerization of alkylene oxide to an initiator having two or more active hydrogen atoms. Specific examples of initiators include aliphatic polyhydric alcohols (e.g., glycols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexylene glycol, and cyclohexanedimethanol; triols such as trimethylolpropane and glycerin; tetrafunctional alcohols such as pentaerythritol; and highly functional alcohols such as sucrose and sorbitol), aliphatic amines (e.g., alkylenediamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, and neopentyldiamine; alkanolamines such as monoethanolamine and diethanolamine), and aromatic amines (e.g., aniline, tolylenediamine, xylylenediamine, diphenylmethanediamine, and Mannich condensation products). These may be used alone or in combination of two or more.

[0012] The polyether polyol is preferably a tolylenediamine-based polyether polyol, a Mannich-based polyether polyol, a sucrose-based polyether polyol, a sorbitol-based polyether polyol, or an ethylenediamine-based polyether polyol. These polyether polyols may be used alone or in combination of two or more.

[0013] The tolylenediamine-based polyether polyol is a polyether polyol obtained using tolylenediamine as an initiator. The same applies to sucrose-based polyether polyols, sorbitol-based polyether polyols, and ethylenediamine-based polyether polyols. The Mannich polyether polyol is a polyether polyol obtained by utilizing the Mannich reaction, which is a Mannich condensation product having two or more hydroxyl groups in the molecule, or a polyether polyol obtained by adding an alkylene oxide to such a Mannich condensation product. More specifically, it is a Mannich condensation product obtained by the Mannich reaction of at least one of phenol and its alkyl-substituted derivatives, formaldehyde, and alkanolamine, or a polyether polyol obtained by ring-opening addition polymerization of this compound with at least one of ethylene oxide and propylene oxide.

[0014] 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.

[0015] 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.

[0016] The average hydroxyl value of the polyol used in the present invention is preferably from 100 to 500 mgKOH / g, more preferably from 150 to 450 mgKOH / g, and even more preferably from 170 to 350 mgKOH / g, from the viewpoint of improving the flame retardancy of the polyurethane foam. When one type of polyol is used, the average hydroxyl value is the hydroxyl value of that one type of polyol, and when two or more types of polyols are used, it is the average value of the hydroxyl groups in accordance with the blending ratio of the two or more types of polyols. For example, when two types of polyols, polyol (d1) and polyol (d2), are used as polyols, the hydroxyl value of polyol (d1) is X1, the blending ratio is m1, and the hydroxyl value of polyol (d2) is X2, the blending ratio is m2, the average hydroxyl value is expressed by the following formula: Note that the blending ratio is based on mass. Average hydroxyl value (mgKOH / g)=X1×(m1 / (m1+m2))+X2×(m2 / (m1+m2)) The hydroxyl value is a value measured in accordance with JIS K1557-1:2007.

[0017] [catalyst] The liquid polyol agent of the present invention contains a catalyst. The catalyst includes a resinification catalyst and a trimerization catalyst. By including the resinification catalyst and the trimerization catalyst in the catalyst, the urethanization reaction and the trimerization reaction can be appropriately promoted, and a polyurethane foam having excellent foaming properties and flame retardancy can be obtained.

[0018] In the polyol liquid, the mass ratio (hereinafter also referred to as parts ratio) of the content of the resinification catalyst to the content of the trimerization catalyst is 0.4 to 1.0. If the ratio of the number of parts of the resinification catalyst to the trimerization catalyst is less than 0.4, two-stage foaming behavior due to the trimerization catalyst and the resinification catalyst is likely to occur, making it difficult to obtain uniform and sufficient adhesion within the elongated hollow portion. From the above perspective, the ratio of the number of parts of the resinification catalyst to the trimerization catalyst is preferably 0.43 or more, more preferably 0.46 or more, and even more preferably 0.49 or more. Furthermore, if the ratio of the number of parts of the resinification catalyst to the trimerization catalyst exceeds 1.0, the flame retardancy of the resulting polyurethane foam will be insufficient. From the above perspective, the ratio of the number of parts of the resinification catalyst to the trimerization catalyst is preferably 0.90 or less, more preferably 0.85 or less, and even more preferably 0.80 or less. The above-mentioned ratios in parts are based on the content of the resinification catalyst and trimerization catalyst themselves. For example, resinification catalysts and trimerization catalysts are often sold as products dissolved in a solvent. In such cases, the content of the resinification catalyst and trimerization catalyst of the present invention refers to the amount of the catalyst itself dissolved in the solvent, not including the amount of the solvent.

[0019] <Resinification catalyst> The resinification catalyst is a catalyst that promotes the reaction between polyol and polyisocyanate. Examples of the resinification catalyst include amine catalysts such as imidazole compounds and piperazine compounds, and metal catalysts. When using an amine catalyst, it is preferable to use one other than the above-mentioned reaction retarders, more specifically, an amine catalyst other than the above-mentioned acid-blocked catalyst. The amine catalyst may be the same as or different from the amino compound capable of generating the acid-blocked catalyst. As the amine catalyst, an imidazole compound is preferred. 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.

[0020] 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-based catalysts and metal-based catalysts, and among them, amine-based catalysts are more preferred from the viewpoint of controlling the reaction rate with a reaction retarder and making it easier to suppress variations in density of the polyurethane foam.

[0021] The content of the resinification catalyst in the polyol liquid is preferably 0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 8 parts by mass, per 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. Furthermore, when a resinification catalyst and a trimerization catalyst are used in combination, by adjusting the content of the resinification catalyst within the above range and the content of the trimerization catalyst within the specified range described below, the ability of the polyurethane composition to fill hollow spaces in structures is improved, and the physical properties of the resulting polyurethane foam, such as flame retardancy, are also improved.

[0022] <Trimerization catalyst> The trimerization catalyst reacts with the isocyanate groups contained in the polyisocyanate to trimerize them and promote the formation of isocyanurate rings. The trimerization catalyst may be one other than the reaction retarders described below, and it is preferable to use a trimerization catalyst other than the acid-blocked catalyst described below. Specifically, nitrogen-containing aromatic compounds such as tris(dimethylaminomethyl)phenol, 2,4-bis(dimethylaminomethyl)phenol, and 2,4,6-tris(dialkylaminoalkyl)hexahydro-S-triazine; alkali metal carboxylates such as potassium acetate, potassium 2-ethylhexanoate, and potassium octoate; and tertiary ammonium salts such as trimethylammonium salts, triethylammonium salts, and triphenylammonium salts. Examples of quaternary ammonium salts include quaternary ammonium carboxylates. Examples of the carboxylic acid in the quaternary ammonium carboxylate include carboxylic acids having about 1 to 10 carbon atoms, such as 2-ethylhexanoic acid, 2,2-dimethylpropanoic acid, acetic acid, and formic acid. Examples of the quaternary ammonium ion in the quaternary ammonium carboxylate include triethylmethylammonium ion, tetramethylammonium ion, tetraethylammonium ion, tetraphenylammonium ion, hydroxybutyltrimethylammonium ion, and hydroxypropyltrimethylammonium ion. The trimerization catalyst may be used alone or in combination of two or more kinds. The trimerization catalyst is preferably at least one of an alkali metal carboxylate and a quaternary ammonium salt, more preferably an alkali metal carboxylate, and even more preferably potassium 2-ethylhexanoate.

[0023] The content of the trimerization catalyst is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 18 parts by mass, and even more preferably 5 to 15 parts by mass, per 100 parts by mass of the polyol. When the content of the trimerization catalyst is within this range, the trimerization reaction can proceed appropriately. Furthermore, when the resinification catalyst and the trimerization catalyst are used in combination, adjusting the content of the resinification catalyst and the content of the trimerization catalyst to fall within the respective ranges described above improves the ability of the polyurethane composition to fill hollow spaces in the structure, and improves the physical properties, such as flame retardancy, of the resulting polyurethane foam.

[0024] The polyol liquid of the present invention preferably has a catalyst content of 0.3 to 8 mass%, more preferably 0.5 to 7 mass%, and even more preferably 1 to 6 mass%. When the catalyst content is equal to or greater than the above-mentioned lower limit, the reaction between the polyol and the polyisocyanate is sufficient, making it easier to obtain a polyurethane foam with excellent flame retardancy. When the catalyst content is equal to or less than the above-mentioned upper limit, the reactivity between the polyol and the polyisocyanate is appropriate, making it easier to fill the entire hollow portion of the structure with the composition and to suppress variations in the density of the polyurethane foam. The catalyst amount of the catalyst described above is the amount of the catalyst itself based on the total amount of the polyol liquid. For example, the catalyst is often sold as a product dissolved in a solvent, and in this case, the catalyst content of the present invention does not include the amount of the solvent in which the catalyst is dissolved, but means the amount of the catalyst itself dissolved in the solvent.

[0025] [Reaction retarder] The liquid polyol of the present invention contains a reaction retarder, which controls the curing time when a polyurethane foam is formed, and enables the formation of a polyurethane foam that has excellent filling properties when filling hollow spaces in a structure and has little density variation from place to place. The reaction retarder preferably contains an acid component, more preferably at least one selected from carboxylic acids and acid-blocking catalysts, and even more preferably at least one selected from hydroxycarboxylic acid compounds and amine-based acid-blocking catalysts. The reaction retarder containing an acid component makes it easier to control the curing time when a polyurethane foam is formed. The principle by which the curing time is controlled by the reaction retarder is not clear, but it is presumed that the acid component in the reaction retarder blocks the amine catalyst described below, slowing down the rate of the curing reaction between the polyol and polyisocyanate. The reaction retarder may be contained alone or in combination of two or more kinds.

[0026] As the carboxylic acid, a hydroxycarboxylic acid compound or a carboxylic acid having no hydroxyl group can be used, but it is preferable to use a hydroxycarboxylic acid compound, since the hydroxyl group of the hydroxycarboxylic acid compound reacts with the polyisocyanate described below, making it easier to inhibit the reaction. Hydroxycarboxylic acid compounds are compounds having a hydroxyl group and a carboxyl group, and specific examples thereof include aliphatic hydroxycarboxylic acid compounds such as lactic acid, glycolic acid, 2-hydroxybutyric acid, and 3-hydroxybutyric acid, and aromatic hydroxycarboxylic acid compounds such as salicylic acid, coumaric acid, mandelic acid, benzilic acid, atrolactic acid, ferulic acid, sinapic acid, vanillic acid, and 4-hydroxybenzoic acid. The hydroxycarboxylic acid compound may also be a reaction product obtained by esterification of a dicarboxylic acid component and a dihydric alcohol component. It is preferable that such a reaction product have one hydroxyl group and one carboxyl group. Examples of the dicarboxylic acid component include phthalic acid, phthalic anhydride, isophthalic acid, and terephthalic acid. Examples of the dihydric alcohol component include ethylene glycol, diethylene glycol, and triethylene glycol. The dicarboxylic acid component and the dihydric alcohol component may each be used alone or in combination of two or more. The hydroxycarboxylic acid compound preferably has one hydroxyl group, and more preferably has one hydroxyl group and one carboxyl group.

[0027] As the carboxylic acid without a hydroxyl group, an aliphatic carboxylic acid or a carboxylic acid having an aromatic ring can be used. The aliphatic carboxylic acid is not particularly limited and may be saturated or unsaturated, and may be linear or branched. Examples of the aliphatic carboxylic acid include an aliphatic carboxylic acid having an aliphatic hydrocarbon group having 1 to 10 carbon atoms, such as formic acid, acetic acid, propionic acid, butyric acid, and valeric acid. Examples of the carboxylic acid having an aromatic ring include a carboxylic acid having a monocyclic (non-polycyclic) aromatic ring and a carboxylic acid having a polycyclic aromatic ring. Examples of carboxylic acids having a monocyclic (non-polycyclic) aromatic ring include benzoic acid, phthalic acid (orthophthalic acid, isophthalic acid, terephthalic acid), etc. Examples of carboxylic acids having a polycyclic aromatic ring include naphthoic acid, etc. Of the above-mentioned carboxylic acids not having a hydroxyl group, it is preferable to use an aliphatic carboxylic acid having an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and it is more preferable to use formic acid.

[0028] As mentioned above, an acid-blocked catalyst can also be used as a reaction retarder. The acid-blocked catalyst has low activity at low temperatures and increases in activity with increasing temperature.

[0029] As the acid blocking catalyst, it is preferable to use an amine-based acid blocking catalyst in which an amino compound is blocked with a carboxylic acid. As the carboxylic acid, the above-mentioned compounds can be suitably used, but it is preferable to use formic acid. In the early stages of the curing reaction between polyol and polyisocyanate, the acid-blocked catalyst blocks the activity of catalytic compounds such as amines, thereby slowing the reaction rate. After that, as the temperature rises due to the heat of the curing reaction, the acid block is removed, allowing the intrinsic activity of catalytic compounds such as amines to be expressed and accelerate the curing reaction.

[0030] Examples of the amino compound include aliphatic amines and aromatic amines. The amine compound is preferably a tertiary amine, and more preferably a tertiary aliphatic amine. Examples of the amino compound include those having about 6 to 18 carbon atoms. Specific examples of the amino compound that can be used include triethylamine, N-methylmorpholine bis(2-dimethylaminoethyl) ether, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N'-trimethylaminoethyl-ethanolamine, bis(2-dimethylaminoethyl) ether, N-methyl-N',N'-dimethylaminoethylpiperazine, N,N-dimethylcyclohexylamine, diazabicycloundecene, diazabicyclononene, trimethylaminoethylpiperazine, tripropylamine, and bisdiethylaminoethyl ether. Among these, tertiary aliphatic amines having multiple nitrogen atoms are preferred, and among these, it is preferable to use at least one selected from N,N,N',N",N"-pentamethyldiethylenetriamine, diazabicycloundecene, diazabicyclononene, triethylenediamine, and bisdiethylaminoethyl ether, and it is more preferable to use N,N,N',N",N"-pentamethyldiethylenetriamine.

[0031] In the present invention, it is preferable to use at least one selected from a hydroxycarboxylic acid compound and an amine-based acid blocking catalyst as the reaction retarder, more preferably at least one selected from a hydroxycarboxylic acid compound and a formic acid blocking catalyst, and even more preferably a hydroxycarboxylic acid compound. The use of these substances as reaction retarders makes it easier to suppress density variations in polyurethane foams and to impart excellent flame retardancy to the polyurethane foams. Furthermore, the overall molecular weight of the reaction retarder increases, making it easier to improve the storage stability of the polyol liquid.

[0032] The content of the reaction retarder is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 7 parts by mass, and even more preferably 0.5 to 4 parts by mass, per 100 parts by mass of polyol. When the content of the reaction retarder is equal to or greater than the above-mentioned lower limit, excellent filling properties are easily imparted to the polyol liquid. Furthermore, when the content of the reaction retarder is equal to or less than the above-mentioned upper limit, the rate of the curing reaction between the polyol and the polyisocyanate is ensured to be at least constant, thereby making the density of the polyurethane foam filled therein appropriate and making it easier to impart excellent flame retardancy to the polyurethane foam.

[0033] [Flame retardant] The polyol liquid contains a flame retardant, which can more effectively enhance flame retardancy and impart high flame retardancy to the polyurethane foam. The flame retardant may be a solid flame retardant or a liquid flame retardant. A solid flame retardant is a flame retardant that is solid at room temperature (23°C) and normal pressure (1 atmosphere).

[0034] <Solid flame retardant> From the viewpoint of more effectively enhancing flame retardancy, the solid flame retardant is preferably 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.

[0035] <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.

[0036] The blending amount of the red phosphorus-based 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 making the blending amount of the red phosphorus-based flame retardant 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 making the blending amount equal to or less than the upper limits, foaming is not inhibited by the red phosphorus-based flame retardant.

[0037] <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.

[0038] The amount 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, per 100 parts by mass of polyol. By setting the amount of the boron-containing flame retardant to be equal to or greater than 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 amount to be equal to or less than the upper limits, foaming is not inhibited by the boron-containing flame retardant.

[0039] <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.

[0040] 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.

[0041] The blending amount 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, per 100 parts by mass of the polyol. By blending the amount of the bromine-containing flame retardant at or above these lower limits, the effect of the inclusion of the bromine-containing flame retardant is easily exhibited. On the other hand, by blending the amount at or below the upper limits, foaming is not inhibited by the bromine-containing flame retardant.

[0042] <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.

[0043] 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.

[0044] The amount 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 setting the amount of the phosphate-containing flame retardant to be equal to or greater than these lower limits, the effect of the phosphate-containing flame retardant is more easily exhibited. On the other hand, by setting the amount to be equal to or less than the upper limits, foaming is not inhibited by the phosphate-containing flame retardant.

[0045] <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 blending amount 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 blending the amount of the chlorine-containing flame retardant at or above these lower limits, the effect of the inclusion of the chlorine-containing flame retardant is easily exhibited. On the other hand, by blending the amount at or below the upper limits, foaming is not inhibited by the chlorine-containing flame retardant.

[0046] <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.

[0047] The amount of antimony-containing flame retardant blended 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, per 100 parts by mass of polyol. By blending the amount of 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 blending the amount at or below the upper limits, foaming is not inhibited by the antimony-containing flame retardant.

[0048] <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.

[0049] The amount of metal hydroxide blended 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 polyol. By blending the amount of metal hydroxide at or above these lower limits, the effect of containing the metal hydroxide is easily exerted, and flame retardancy is improved. On the other hand, by blending the amount at or below the upper limits, foaming is not inhibited by the metal hydroxide.

[0050] Of the solid flame retardants mentioned above, red phosphorus-based flame retardants, boron-containing flame retardants, bromine-containing flame retardants, and the like are preferred. It is also preferable to use a combination of multiple solid flame retardants. In this case, it is preferable to use a red phosphorus-based flame retardant, a boron-containing flame retardant, and a bromine-containing flame retardant in combination. By using these in combination, it is easier to further improve flame retardancy.

[0051] <Solid flame retardant blend amount> The amount of the solid flame retardant is not particularly limited, but is, for example, 10 to 150 parts by mass, preferably 20 to 100 parts by mass, and more preferably 40 to 80 parts by mass, relative to 100 parts by mass of the polyol. By adjusting the amount of the solid flame retardant to be equal to or greater than these lower limits, it is possible to impart appropriate flame retardancy to the polyurethane foam. By adjusting the amount of the solid flame retardant to be equal to or less than these upper limits, it becomes easier to fill the polyurethane composition inside the structure, making it easier to obtain a polyurethane foam with little density variation depending on the location.

[0052] Liquid flame retardant The liquid polyol agent may contain a liquid flame retardant. A liquid flame retardant is a flame retardant that is liquid at room temperature (23°C) and normal pressure (1 atmosphere). A specific example of a liquid flame retardant is a phosphate ester. Unlike solid flame retardants, liquid flame retardants are less likely to produce sediment during storage and are easier to handle.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] When a liquid flame retardant is contained, the blending amount thereof is preferably from 5 to 80 parts by mass, more preferably from 10 to 70 parts by mass, and even more preferably from 20 to 60 parts by mass, relative to 100 parts by mass of the polyol.

[0057] [Foaming agent] The polyol liquid of the present invention preferably contains a foaming agent. The foaming agent can be used to mix the polyol liquid and the polyisocyanate liquid and foam them to form a polyurethane foam. The foaming agent is contained in at least one of the polyol liquid and the polyisocyanate liquid described below, but is preferably contained in the polyol liquid. The blowing agent is not particularly limited, but examples thereof include organic blowing agents such as hydrocarbon compounds, chlorinated aliphatic hydrocarbon compounds, hydrofluorocarbons, hydrochlorofluorocarbon compounds, and hydrofluoroolefins; inorganic blowing agents such as nitrogen gas, oxygen gas, argon gas, and carbon dioxide gas; and water. Of these, it is preferable to use organic blowing agents and water.

[0058] Examples of the hydrocarbon compound include propane, butane, pentane, hexane, heptane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, and cycloheptane. Examples of the chlorinated aliphatic hydrocarbon compounds include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride. Examples of the hydrofluorocarbon include CHF3, CH2F2, and CH3F.

[0059] Examples of the hydrochlorofluorocarbon compounds include 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).

[0060] Examples of the hydrofluoroolefin include fluoroalkenes having 3 to 6 carbon atoms. The hydrofluoroolefin may also be a hydrochlorofluoroolefin having a chlorine atom, and therefore may be a chlorofluoroalkene having 3 to 6 carbon atoms. The hydrofluoroolefin preferably has 3 or 4 carbon atoms. 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)).

[0061] From the viewpoints of good foam formation and reducing the environmental load, it is preferable to use a hydrofluoroolefin as the foaming agent.

[0062] The content of the blowing agent is preferably 15 to 90 parts by mass, more preferably 25 to 80 parts by mass, and even more preferably 30 to 70 parts by mass, per 100 parts by mass of the polyol. When the content of the blowing agent is equal to or greater than the lower limit, foaming is promoted, fluidity is increased, and the density of the resulting polyurethane foam can be reduced. 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.

[0063] As the blowing agent, it is preferable to use at least a hydrofluoroolefin, and it is also preferable to use a hydrofluoroolefin in combination with water. The content of hydrofluoroolefin as a blowing agent is preferably 10 to 85 parts by mass, more preferably 15 to 75 parts by mass, and even more preferably 20 to 70 parts by mass. The content of water as a blowing agent is preferably 0.2 to 15 parts by mass, more preferably 0.4 to 10 parts by mass, and even more preferably 0.6 to 5 parts by mass.

[0064] [Foam stabilizer] The polyol liquid preferably contains a foam stabilizer, which improves the foamability of the polyurethane composition obtained from the polyol liquid and the polyisocyanate liquid. Examples of the foam stabilizer include surfactants such as polyoxyalkylene-based foam stabilizers (e.g., polyoxyalkylene alkyl ethers) and silicone-based foam stabilizers (e.g., organopolysiloxanes). Among these, silicone-based foam stabilizers are preferred. These foam stabilizers may be used alone or in combination of two or more. The amount of foam stabilizer blended 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 amount of foam stabilizer blended is equal to or greater than these lower limits, the polyurethane composition becomes easier to foam, making it easier to obtain a homogeneous polyurethane foam. When the amount of foam stabilizer blended is equal to or less than these upper limits, a good balance between production costs and the obtained effects is achieved.

[0065] [Settling inhibitor] The polyol liquid preferably contains a settling inhibitor. The settling inhibitor inhibits the precipitation of the solid flame retardant dispersed in the polyol liquid and the inorganic filler described below during long-term storage at room temperature or low temperature. Furthermore, it also prevents caking due to the settled solid flame retardant and the inorganic filler described below. Even if the solid flame retardant and the inorganic filler described below settle after long-term storage, they can be easily and uniformly dispersed by stirring with a stirrer or the like. Settling inhibitors generally become solid at room temperature and normal pressure, and usually become solids (insolubles) in the liquid.

[0066] The settling inhibitor is not particularly limited. Specific examples of the settling inhibitor include powdered silica, organic clay, carbon black, hydrogenated castor oil wax, fatty acid amide wax, etc. One or more of these may be used. Examples of powdered silica that can be used include fumed silica, colloidal silica, and silica gel. Of these, fumed silica is preferred, and hydrophobic fumed silica is particularly preferred. Examples of fumed silica that can be used include Aerosil (registered trademark) from Nippon Aerosil Co., Ltd. As the organoclay, organophilic phyllosilicates and the like can be used. The carbon black that can be used is produced by a furnace method, a channel method, a thermal method, etc. The carbon black may be appropriately selected from commercially available products. Hydrogenated castor oil wax, fatty acid amide wax, etc. form a swollen gel structure in liquid. These agents are generally commercially available under names such as thixotropic agents, thickeners, anti-settling agents, and anti-sagging agents, and commercially available products can be appropriately selected and used.

[0067] The preferred anti-settling agent is a thickening agent, and more preferably, the anti-settling agent contains Si as an element. Specific examples of the thickening agent include fumed silica and organophilic phyllosilicates, and more preferably, fumed silica.

[0068] When a settling inhibitor is contained, its content is not particularly limited, but is, for example, 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 1 to 5 parts by mass, relative to 100 parts by mass of polyol. By setting the content of the settling inhibitor to at least the above-mentioned lower limit, the polyol solution is thickened, and settling of the solid flame retardant and the inorganic filler described below is suppressed, thereby improving their dispersibility. Furthermore, by setting the content of the settling inhibitor to at most the above-mentioned upper limit, deterioration in handleability due to an excessive increase in the viscosity of the solution is prevented.

[0069] [Other ingredients] The polyol liquid may contain one or more additives selected from phenolic, amine, sulfur-based and other antioxidants, inorganic fillers other than solid flame retardants and anti-settling agents, 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.

[0070] [Polyurethane composition] The polyurethane composition of the present invention contains the above-described liquid polyol and liquid polyisocyanate. The polyurethane foam of the present invention is formed from the polyurethane composition. Specifically, the polyurethane foam of the present invention is a reaction product obtained by reacting and foaming a polyurethane composition obtained by mixing the liquid polyol and the liquid polyisocyanate. The polyurethane composition used in the present invention is generally a two-component type, and it is preferable to mix the polyol liquid of the present invention and the polyisocyanate liquid, which have been stored separately, and allow them to react and foam to obtain a polyurethane foam. Note that the polyisocyanate liquid may contain components other than polyisocyanate, such as the above-mentioned filler, blowing agent, catalyst, and other components, as necessary.

[0071] (Polyisocyanate) The polyisocyanate liquid contains a polyisocyanate. As the polyisocyanate, any known polyisocyanate used in the formation of polyurethane foam can be used, such as an aromatic polyisocyanate, an alicyclic polyisocyanate, or an aliphatic polyisocyanate. Examples of aromatic polyisocyanates include phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, and polymethylene polyphenyl polyisocyanate.

[0072] Examples of alicyclic polyisocyanates include cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and dimethyldicyclohexylmethane diisocyanate.

[0073] Examples of the aliphatic polyisocyanate include methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate.

[0074] Among these, from the viewpoints of ease of use and availability, aromatic polyisocyanates are preferred, and diphenylmethane diisocyanate is more preferred. One type of polyisocyanate may be used alone, or two or more types may be used in combination.

[0075] (Isocyanate Index) The isocyanate index of the polyurethane composition of the present invention is not particularly limited, but is preferably 200 to 600, and more preferably 300 to 550. If the isocyanate index is equal to or greater than the lower limit, the amount of polyisocyanate relative to the polyol becomes excessive, facilitating the formation of isocyanurate bonds due to the trimerization of the polyisocyanate, resulting in improved flame retardancy of the polyurethane foam. Furthermore, if the isocyanate index is equal to or greater than the lower limit, it becomes easier to produce a polyurethane foam having isocyanurate bonds, i.e., a polyurethane foam that combines high levels of flame retardancy and thermal insulation. Furthermore, if the isocyanate index is equal to or less than the upper limit, the resulting polyurethane foam will have a good balance between flame retardancy and production costs.

[0076] The isocyanate index can be calculated by the following method. Isocyanate Index = number of equivalents of polyisocyanate ÷ (number of equivalents of polyol + number of equivalents of water) × 100 Here, each equivalent number can be calculated as follows: Polyisocyanate equivalent number = 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.

[0077] When mixing the polyol liquid and the polyisocyanate liquid, the volume ratio of the two (polyol liquid / polyisocyanate liquid) may be set within the range of, for example, 1 / 1.4 to 1.4 / 1, preferably 1 / 1.2 to 1.2 / 1.

[0078] (Cream time, Gel time) The gel time of the polyurethane composition of the present invention is preferably 4 to 100 seconds, more preferably 10 to 60 seconds, and even more preferably 20 to 45 seconds. If the gel time is equal to or less than these upper limits, the urethane reaction proceeds appropriately, resulting in good performance as a polyurethane foam. If the gel time is equal to or greater than the lower limit, filling defects and density variations are less likely to occur when the polyurethane composition is filled into hollow spaces in a structure. Here, the gel time is the value measured when the liquid temperature of the polyurethane composition is adjusted to 40°C. The gel time is measured from the time when the polyol liquid and the polyisocyanate liquid are mixed and stirring is started (measurement start time: 0 seconds), and is the time (seconds) until the foam becomes stringy when a stick is pierced into the foam during foaming.

[0079] The cream time of the polyurethane composition of the present invention is preferably 3 to 15 seconds, more preferably 4 to 12 seconds, and even more preferably 6 to 10 seconds. The cream time is the time from the start of mixing the polyol liquid and the polyisocyanate liquid and starting to stir (measurement start time: 0 seconds) until the mixed solution starts to react and the color of the solution starts to change.

[0080] From the viewpoint of improving the fluidity of the polyol composition during filling, the difference between the gel time and the cream time (gel time - cream time) is preferably 10 seconds or more, more preferably 12 seconds or more, and even more preferably 15 seconds or more, and from the viewpoint of ensuring a certain level of flame retardancy, it is preferably 90 seconds or less, more preferably 55 seconds or less, and even more preferably 40 seconds or less. The cream time and gel time can be adjusted to desired values ​​by adjusting the types of polyol and polyisocyanate used, the isocyanate index, the type and amount of reaction retarder, the type and amount of catalyst, the liquid temperature, the body temperature, etc. In the present invention, the use of a reaction retarder makes it easier to lengthen the gel time. The specific methods for measuring the cream time and gel time are as described in the Examples.

[0081] [Method for producing liquid polyol, polyurethane composition, and polyurethane foam] The method for producing the liquid polyol of the present invention and the polyurethane composition containing the same is not particularly limited, but preferably comprises the following steps (1) to (3): Then, a polyurethane foam may be formed from the polyurethane composition obtained through steps (1) to (3). Step (1): A step of mixing the components constituting the polyol liquid, except for the catalyst and the reaction retarder, to obtain a mixed liquid. Step (2): A step of adding and mixing a catalyst and a reaction retarder to the mixture obtained in step (1) to obtain a polyol liquid. Step (3): A step of mixing the polyol liquid obtained in step (2) with the polyisocyanate liquid to obtain a polyurethane composition.

[0082] The liquid polyol and polyurethane composition of the present invention typically contain a blowing agent. Even in such cases, by producing them by the production method including the above steps (1) to (3), the two-stage foaming behavior caused by the trimerization catalyst and the resinification catalyst can be suppressed, and uniform and sufficient adhesion can be obtained within the elongated hollow space, thereby satisfying the filling performance of closed spaces. The detailed procedures for each step will be described below.

[0083] In step (1), the components constituting the polyol liquid other than the catalyst and the reaction retarder, i.e., the polyol and filler, as well as any liquid flame retardant, blowing agent, foam stabilizer, etc., may be mixed. In step (2), when the catalyst and the reaction retarder are added to the mixed solution obtained in step (1), they may be added in a mixed state or may be added separately. The catalyst and the reaction retarder are preferably added immediately before mixing the polyisocyanate liquid with the polyol liquid. There are no particular limitations on the mixing method in steps (1) and (2). For example, the components can be mixed at room temperature using a mixer such as a Homodisper for about 30 seconds to 20 minutes.

[0084] The mixing method in step (3) is not particularly limited, and the polyol liquid agent and the polyisocyanate liquid agent obtained in step (2) may be mixed by a known method. Specifically, the mixture can be obtained using known devices such as a high-pressure foaming machine, a low-pressure foaming machine, a spray foaming machine, or a hand mixer.

[0085] The polyurethane composition obtained as described above may be filled into the hollow portion of a metal frame such as a flat deck using a spray gun, etc. More specifically, it is preferable to use a foaming device equipped with a spray gun, mix a polyol liquid agent and a polyisocyanate liquid agent in the foaming device, and fill the spray gun with the mixture. The polyurethane composition filled by the spray gun is filled into the hollow space of a metal frame such as a flat deck, and the polyol and polyisocyanate react with each other to foam, thereby forming a polyurethane foam. As described above, the polyurethane composition uses a specific polyol liquid, so the two-stage foaming behavior caused by the trimerization catalyst and resinification catalyst is suppressed in the formed polyurethane foam, and uniform and sufficient adhesion can be obtained within the elongated hollow space, thereby satisfying the filling performance of closed spaces. However, the above-described manufacturing method is merely an example, and the liquid polyol, polyurethane composition, and polyurethane foam may be manufactured by methods other than those described above, as long as the polyurethane composition is obtained by mixing the components constituting the polyurethane composition (i.e., polyol, polyisocyanate, catalyst, reaction retarder, flame retardant, and other optional components). For example, in the above description, in steps (1) and (2), components other than the catalyst and reaction retarder are mixed to obtain a mixed liquid, and then the catalyst and reaction retarder are added. However, the order of addition is not limited to this, and each component may be added and mixed simultaneously. Furthermore, in steps (1) and (2), components other than the catalyst and reaction retarder may be added to and mixed with the mixed liquid obtained by mixing the catalyst and reaction retarder to obtain a liquid polyol.

[0086] [Use of polyol liquid and polyurethane composition] As described above, the liquid filler polyol of the present invention and the filling polyurethane composition containing the same are used for filling hollow spaces in a structure. The structure may be a completed structure manufactured through a series of steps in a factory or the like, or an unfinished structure before the completion of the completed structure. Filling the hollow portion of a completed structure with the polyurethane composition primarily involves filling a hollow portion surrounded by components constituting the completed structure, for example, by providing an injection port in a portion of the completed structure. Filling the hollow portion of an unfinished structure involves filling as part of the manufacturing process prior to forming the completed structure, for example, filling a hollow portion that is at least partially open. Specifically, in the manufacturing process, an unfinished structure having an open hollow portion is manufactured, the polyurethane composition is filled into the hollow portion through the open portion to form a polyurethane foam, and the open portion is then sealed. The open portion can be sealed by gluing or welding the open portion, for example. Alternatively, the open portion may be sealed by providing a member to cover the open portion.

[0087] The completed structure is not particularly limited as long as it has a hollow portion, and may be a component used in a building or a component used in a vehicle such as an automobile. Specific examples of the completed structure include plate-like members and frame materials. Examples of plate-like members include panels and flat decks. The panel is not particularly limited as long as it has a hollow portion, and may be a panel of any shape when viewed from the front, such as a rectangle, a square, a triangle, etc. The entire interior of the panel may be hollow, or the panel may be provided with multiple members, and part of the hollow portion inside the panel may be an elongated hollow portion. The flat deck can be obtained by subjecting a metal plate such as a galvanized steel plate to a bending process such as roll forming. Flat decks are used in floor or roof construction, for example as formwork onto which concrete is poured. The flat deck has a flat portion with a flat upper surface, and a plurality of reinforcing ribs protruding from the lower surface of the flat portion. Each reinforcing rib is a protrusion with a hollow portion therein, extending along the longitudinal direction, with both longitudinal ends thereof crushed and closed. The hollow portion of each reinforcing rib is an elongated hollow portion. The cross-sectional shape of the reinforcing rib of the flat deck is not particularly limited as long as a hollow portion is formed therein, and may be triangular, rectangular, or another shape. In the flat deck, the polyurethane composition is filled into the hollow portion of the reinforcing rib, and the reinforcing rib is provided with an injection hole for injecting the polyurethane composition into the hollow portion.

[0088] A frame material is a component that has an elongated hollow portion inside and constitutes part or all of a frame body that surrounds an opening in a fixture such as a window, door, etc. For example, the frame body is made up of a pair of side frame portions, an upper frame portion, and a lower frame portion, and the frame material may constitute at least a part of these frame portions.

[0089] An unfinished structure is, for example, a structure in the manufacturing stage of a finished structure such as the above-mentioned plate-like member or frame material, and is, for example, a structure with a portion open. An example of an unfinished structure is a flat deck, in which a metal plate such as a steel plate has multiple recesses with openings formed therein using a roll molding machine or the like. A flat deck can be manufactured by filling the recesses of the structure through the openings with a polyurethane resin composition and then closing the openings by means such as welding to form reinforcing ribs. Another example of an unfinished structure is a structure that is partially open due to the absence of a portion of the side surface that constitutes a panel. A panel can be manufactured by filling the open portion with a polyurethane composition and then closing it with a member that constitutes the side surface.

[0090] The polyurethane composition containing the polyol liquid of the present invention has excellent filling properties, so even if the structure has an elongated hollow portion, it can be filled all the way to the end, and a high-quality polyurethane foam with little density variation depending on the location can be formed. An elongated hollow portion is one in which the longitudinal length is, for example, at least 2 times, preferably at least 2.5 times, and more preferably at least 5 times the cross-sectional dimension. Here, the cross-sectional dimension refers to the maximum length of the cross section of the hollow portion, and is, for example, the major axis in the case of an ellipse, or the length of the diagonal in the case of a rectangle or square. If the size of the cross-sectional shape (i.e., the cross-sectional dimension) varies along the longitudinal direction, the maximum cross-sectional dimension of the varying portion may be taken as the cross-sectional dimension. In the case of a structure having an elongated hollow portion, the structure may be either a completed structure or an unfinished structure, but in the case of a completed structure, the polyurethane composition may be filled into the hollow portion from the end of the elongated hollow portion or through the injection hole as described above. Even in such cases, the polyurethane composition can be used to fill the hollow portion up to the end. [Example]

[0091] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0092] The components used in each of the examples and comparative examples are as follows.

[0093] <Polyol> p-Phthalic acid-based polyester polyol (Kawasaki Chemical Industries, Ltd., product name: Maximol RLK-087, hydroxyl value 200 mg KOH / g)

[0094] <Reaction retarder> Acid-blocked catalyst (N,N,N',N",N"-pentamethyldiethylenetriamine blocked with formic acid, manufactured by Tosoh Corporation, product name: TOYOCAT-TMF, ethylene glycol 25-30% by mass, formic acid 10-30% by mass) Hydroxycarboxylic acid compound (Kawasaki Chemical Industries, Ltd., product name: RAK253)

[0095] <Catalyst> Resinification catalyst: 1,2-dimethylimidazole (manufactured by Tosoh Corporation, product name: TOYOCAT-DM70) Resinification catalyst: bismuth 2-ethylhexanoate (manufactured by Nitto Kasei Co., Ltd., product name: BI-28) Trimerization catalyst: potassium 2-ethylhexanoate (manufactured by Air Products, product name: DABCO K-15), concentration 70 to 80% by mass Trimerization catalyst: quaternary ammonium carboxylate (manufactured by Evonik Japan, product name: DABCO TMR-7, 2,2-dimethylpropanoic acid tetramethylammonium salt)

[0096] <Foam stabilizer> Silicone foam stabilizer (Toray Dow Corning, product name: SZ1642)

[0097] <Liquid flame retardant> Tris(β-chloropropyl)phosphate (manufactured by Daihachi Chemical Co., Ltd., product name: TMCPP)

[0098] <Solid flame retardant> Red phosphorus flame retardant (Rinkagaku Kogyo Co., Ltd., product name: NovaExcel 140) Zinc borate (Hayakawa Shoji Co., Ltd., product name: Firebrake ZB) Ethylenebis(pentabromophenyl) (Albemarle, product name: SAYTEX 8010)

[0099] <Settling inhibitor> Fumed silica (manufactured by Nippon Aerosil Co., Ltd., product name: Aerosil R976S)

[0100] <Foaming agent> HFO-1233zd(E) (manufactured by Central Glass Co., Ltd., product name: Solstice LBA) ·water

[0101] <Polyisocyanate> Polyisocyanate (MDI, manufactured by Sumitomo Chemical Co., Ltd., product name: Sumidur 44V20)

[0102] <Cream time, gel time> The liquid temperatures of the polyol liquid and the polyisocyanate liquid composed of a polyisocyanate compound, each having the composition shown in Table 1, were adjusted to 40°C. Then, in a room at 23°C, the polyol liquid and the polyisocyanate liquid adjusted to 40°C were poured into a 500 mL cup so that the total amount of the mixed solution was 60 g at the mixing ratio shown in the table. The mixed solution was then immediately stirred at 8000 rpm for 2 seconds using a Labo Body Spa (a high-speed disperser, Homo Disper 2.5 model, manufactured by PRIMIX). The time when stirring began was designated as the measurement start time (0 seconds). The time (seconds) until the mixed solution changed color and the liquid level began to rise due to foaming was measured and recorded as the cream time. Furthermore, the time (seconds) until the foam began to form strings when a stick was pierced into the foam during foaming was measured and recorded as the gel time.

[0103] [Examples 1 to 10, Comparative Examples 1 to 3] A polyol solution and a polyurethane composition were prepared according to the following procedures. (1) Of the components of the polyol liquid, the components other than the reaction retarder and catalyst were mixed in the proportions shown in Table 1. (2) A mixture obtained by mixing a reaction retarder and a catalyst was added to the mixture obtained in (1) above in the proportions shown in Table 1 to obtain a polyol liquid. (3) A polyurethane composition was prepared from the polyol liquid obtained in (2) above and the polyisocyanate liquid.

[0104] The polyol liquid and polyurethane composition obtained by the above steps (1) to (3) were evaluated as follows.

[0105] [Liquidity evaluation] The fluidity of the polyurethane composition was evaluated by measuring the free density and the packed density as described below and calculating the ratio between the two, based on the following criteria: In other words, the more similar the two densities are, the better the fluidity at the time of packing. (standard) Good (Excellent fluidity) Filling density / free density is less than 1.4 × (poor fluidity) Filling density / free density is 1.4 or more

[0106] (Method for measuring packing density) The polyol liquid and polyisocyanate liquid listed in Table 1 were each adjusted to a liquid temperature of 15°C. The polyisocyanate liquid was added to the polyol liquid in the amounts shown in Table 1, and the mixture was quickly stirred for 1.5 seconds using a homodisperser rotating at 8000 rpm to prepare a polyurethane composition. A hollow metal frame with a cross section of 40 mm x 30 mm and a length of 900 mm was heated to 60°C. The polyurethane composition prepared as described above was injected into the longitudinal end of the hollow metal frame, and the injection port was sealed. After sealing, an air hole (φ1 to 5 mm) was created at the end opposite the injected end. The injection amount was adjusted so that the length of the hollow metal frame filled in the longitudinal direction (longitudinal filling rate) was 90% to 99%. The injection port was sealed, and the temperature of the metal frame was maintained at 60° C. for 15 minutes. Thereafter, the weight and dimensions of the resulting polyurethane foam were measured, and the packing density was calculated based on the following formula. Packing density (kg / m 3 ) = (Polyurethane foam weight / Longitudinal filling rate / 100) / (Cross-sectional area of ​​metal frame x length)

[0107] (Method for measuring free density) The polyol liquid and polyisocyanate liquid listed in Table 1 were each adjusted to a liquid temperature of 15°C. The polyisocyanate liquid was added to the polyol liquid in the amounts listed in Table 1, and the mixture was quickly stirred for 2 seconds using a homodisper rotating at 8000 rpm to prepare a polyurethane composition. The polyurethane composition prepared as described above was poured into a metal container measuring 200 mm x 200 mm and 80 mm in height, and allowed to foam and cure to form a polyurethane foam. After the reaction and curing were fully completed, the polyurethane foam was cut on all four sides and processed into a 100 mm x 100 mm x 50 mm rectangular parallelepiped. The density was calculated from the dimensions and weight, and this was taken as the free density.

[0108] [Adhesion evaluation] The hollow section of the reinforcing rib of the flat deck (cross-sectional shape: isosceles triangle (base 40 mm, height 55 mm)) is filled with polyurethane foam. The center and ends of the reinforcing rib are cut in the longitudinal direction (length 3,000 mm) and the cross-sectional condition is checked and evaluated based on the following criteria. (standard) 〇 (Excellent adhesion) No gaps between the inner wall surface of the reinforcing rib and the polyurethane foam × (poor fluidity) ···There is a gap at the interface between the inner wall surface of the reinforcing rib and the polyurethane foam

[0109] [Flame retardancy evaluation] Using the polyurethane foam produced in the above-mentioned free density measurement, a radiant heat intensity of 50 kW / m was measured in accordance with the ISO-5660 test method. 2 The total heat release amount when heated for 20 minutes was measured using a cone calorimeter. The flame retardancy was evaluated according to the following criteria. (standard) ◎ Total calorific value is 6.5MJ / m 2 below Total calorific value is 6.5MJ / m 2 Super 8.0MJ / m 2 below △ Total calorific value is 8.0MJ / m 2 Super 10.0MJ / m 2 below × Total calorific value is 10.0 MJ / m 2 super

[0110] [Table 1]

[0111] The polyurethane compositions formed from the polyol liquid satisfying the requirements of the present invention exhibited a longer gel time, and the polyurethane compositions of each example using this liquid exhibited excellent fluidity, maintaining a low density of the polyurethane foam formed. Furthermore, the two-stage foaming behavior caused by the trimerization catalyst and resinification catalyst was suppressed, resulting in uniform and sufficient adhesion within the elongated hollow space, and satisfying the filling performance of enclosed spaces. Furthermore, the compositions exhibited excellent flame retardancy. On the other hand, in the comparative example using a polyol liquid agent that does not satisfy the requirements of the present invention, the gel time was shorter, the fluidity of the polyurethane composition using the liquid agent was deteriorated, and it was confirmed that the density of the polyurethane foam formed increased. Furthermore, two-stage foaming behavior due to the trimerization catalyst and resinification catalyst was likely to occur, and uniform and sufficient adhesion was not obtained within the elongated hollow portion.

Claims

1. A polyol liquid comprising a polyol, a catalyst, a reaction retarder and a flame retardant, wherein the catalyst comprises a trimerization catalyst and a resinification catalyst, and the mass ratio of the content of the resinification catalyst to the content of the trimerization catalyst is 0.4 to 1.

0.

2. The polyol liquid according to claim 1 , wherein the reaction retarder comprises at least one selected from the group consisting of a hydroxycarboxylic acid compound and an amine-based acid blocking catalyst.

3. The polyol liquid according to claim 1 , wherein the polyol comprises at least one selected from polyester polyols and polyether polyols.

4. The polyol liquid according to claim 1 , further comprising a blowing agent.

5. The polyol liquid according to claim 1, further comprising a foam stabilizer.

6. The polyol liquid according to claim 1, further comprising a settling inhibitor.

7. A polyurethane composition comprising the liquid polyol agent according to any one of claims 1 to 6 and the liquid polyisocyanate agent.

8. The polyurethane composition of claim 7, having an isocyanate index of 200 to 600.

9. 8. The polyurethane composition according to claim 7, wherein the difference between the cream time and the gel time (gel time - cream time) at a liquid temperature of 40°C is 10 to 90 seconds.

10. A polyurethane foam formed from the polyurethane composition of claim 7.

11. A metal frame having an elongated hollow portion filled with the polyurethane foam of claim 10.

12. 12. The metal frame according to claim 11, which is a flat deck having the elongated hollow portion formed by bending a galvanized steel plate.

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