Polyol composition, flame-retardant rigid polyurethane foam and method for producing same

Abstract

To provide a polyol composition capable of obtaining a hard polyurethane foam which suppresses precipitation or agglomeration of a powder and has excellent flame retardancy in a raw material liquid of a polyol composition comprising a powder flame retardant other than red phosphorus and a flame-retardant hard polyurethane foam and to provide a flame-retardant hard polyurethane foam using the same and a method for producing the same.SOLUTION: There is provided a polyol composition comprising a polyol compound, a powder flame retardant other than red phosphorus, an antisettling agent and a dispersant, which is used for the production of a flame-retardant hard polyurethane foam.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polyol composition used in the production of a flame-retardant rigid polyurethane foam, as well as a flame-retardant rigid polyurethane foam using the same and a method for producing the same. [Background technology]

[0002] Rigid polyurethane foam insulation is widely used in buildings due to its excellent insulating performance and easy application. However, fires are often caused by sparks from welding and cutting during construction, renovation, and demolition work, which can lead to the spread of fire in the insulation. In order to reduce such fire accidents, efforts are being made to make the rigid polyurethane foam itself flame retardant, and consideration is being given to adding a flame retardant to the raw material liquid of the rigid polyurethane foam to improve the flame retardancy.

[0003] Red phosphorus, a powder flame retardant, is known as a flame retardant. Red phosphorus is a powder with a high specific gravity and is prone to settling in the raw material liquid of rigid polyurethane foam, so an anti-settling agent is used in combination with it from the viewpoints of storage stability and on-site workability. For example, Patent Document 1 describes the incorporation of metal oxide fine particles as an anti-settling agent for red phosphorus, and Patent Document 2 describes the addition of carbon black, finely powdered silica, hydrogenated castor oil wax, fatty acid amide wax, organic clay, and the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-63396 A [Patent Document 2] JP 2012-219127 A Summary of the Invention [Problem to be solved by the invention]

[0005] Red phosphorus is a substance that has flammability, and therefore, it is necessary to pay careful attention to safety when handling it. In addition, in recent years, development of flame retardants with better flame retardancy than red phosphorus has been progressing, and flame retardants made of various phosphorus compounds are also beginning to be used. For example, as a flame retardant to be used in place of or in combination with red phosphorus, there are powder flame retardants made of phosphorus compounds such as phosphates and phosphinates. Like red phosphorus, these powder flame retardants made of phosphorus compounds are also difficult to dissolve in polyol compounds and polyisocyanate compounds that are raw materials for rigid polyurethane foams, and are powders with large specific gravity, so that it is necessary to use an anti-settling agent in combination with them.

[0006] However, even if only the red phosphorus anti-settling agent described in the above Patent Documents 1 and 2 is added to the powder flame retardant of the phosphorus compound, the sedimentation is not necessarily suppressed well, and further, once the sediment aggregates and solidifies (caking), it may be difficult to uniformly redisperse the settled and aggregated powder by stirring the raw material liquid of the rigid polyurethane foam during construction at the site. As a result, a rigid polyurethane foam having good flame retardancy may not be obtained.

[0007] Therefore, when using a powder flame retardant other than red phosphorus, it is required that the powder (solid) is prevented from settling or agglomerating in the raw material liquid for a polyol composition or a rigid polyurethane foam, and that the powder has excellent handleability for obtaining a uniform raw material liquid.

[0008] The present invention has been made to solve the above-mentioned technical problems, and an object of the present invention is to provide a polyol composition containing a powder flame retardant other than red phosphorus, and a raw material liquid for a flame-retardant rigid polyurethane foam, which suppresses powder sedimentation and aggregation and enables the production of a rigid polyurethane foam having excellent flame retardancy, as well as a flame-retardant rigid polyurethane foam using the same and a method for producing the same. [Means for solving the problem]

[0009] The present invention is based on the finding that, in a polyol composition containing a powder flame retardant other than red phosphorus, the settling and aggregation of the powder can be effectively suppressed by using an anti-settling agent and a dispersant in combination, and further, a rigid polyurethane foam having excellent flame retardancy can be obtained.

[0010] That is, the present invention provides the following [1] to

[11] . [1] A polyol composition for use in the production of a flame-retardant rigid polyurethane foam, comprising a polyol compound, a powder flame retardant other than red phosphorus, an anti-settling agent, and a dispersant. [2] The polyol composition according to the above [1], wherein the powder flame retardant comprises at least one selected from the group consisting of phosphates and phosphinates. [3] The polyol composition according to the above [1] or [2], wherein the anti-settling agent comprises at least one selected from organic bentonite, aliphatic amide wax, and hydrogenated castor oil wax. [4] The polyol composition according to any one of the above [1] to [3], wherein the dispersant contains at least one selected from an organic ammonium salt, a phosphoric acid ester, and a phosphoric acid ester salt. [5] The polyol composition according to any one of the above [1] to [4], wherein the polyol compound comprises a Mannich polyol. [6] The polyol composition according to any one of the above [1] to [5], further comprising a blowing agent. [7] The polyol composition according to the above [6], wherein the blowing agent comprises at least one selected from hydrofluoroolefins and hydrochlorofluoroolefins. [8] The polyol composition according to any one of the above [1] to [7], which contains a catalyst. [9] The polyol composition according to any one of the above [1] to [8], further comprising a foam stabilizer.

[0011]

[10] A flame-retardant rigid polyurethane foam, which is a reaction product of the polyol composition according to any one of the above [1] to [9] and a polyisocyanate compound.

[11] A method for producing a flame-retardant rigid polyurethane foam, comprising mixing the polyol composition according to any one of the above [1] to [9] with a polyisocyanate compound, and foaming and curing the mixture to obtain a flame-retardant rigid polyurethane foam. Effect of the Invention

[0012] According to the present invention, in a polyol composition containing a powder flame retardant other than red phosphorus and a raw material liquid for a flame-retardant rigid polyurethane foam, settling and aggregation of the powder are suppressed, and a polyol composition with excellent handleability can be provided. Furthermore, by using the polyol composition, a rigid polyurethane foam having excellent flame retardancy can be obtained. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The polyol composition of the present invention, as well as the flame-retardant rigid polyurethane foam using the same and the process for producing the same will be described in detail below.

[0014] [Polyol composition] The polyol composition of the present invention is a polyol composition used for producing a flame-retardant rigid polyurethane foam, and contains a polyol compound, a powdery flame retardant other than red phosphorus, an anti-settling agent, and a dispersant. By using such a polyol composition, it is possible to effectively suppress the settling or aggregation of powder in the raw material liquid of a flame-retardant rigid polyurethane foam containing a powder flame retardant other than red phosphorus. This can reduce the workload for uniformly mixing the polyol composition and the raw material liquid of a flame-retardant rigid polyurethane foam during the production of the flame-retardant rigid polyurethane foam, and can also improve the uniform dispersion of the powder in the raw material liquid. In addition, the flame-retardant rigid polyurethane foam produced using the raw material liquid can be obtained as one having excellent flame retardancy due to the powder flame retardant.

[0015] <Polyol compound> Polyol compounds are the main raw material components of flame-retardant rigid polyurethane foams. Polyol compounds are alcohol compounds with two or more hydroxyl groups, and produce polyurethane resins through a polyaddition reaction with polyisocyanate compounds.

[0016] From the viewpoint of excellent flame retardancy, the polyol compound used in the production of the flame-retardant rigid polyurethane foam preferably contains mainly a polyester polyol, and more preferably contains an aromatic polyester polyol. Polyester polyols can impart superior flame retardancy compared to polypropylene glycols and the like that are commonly used as raw materials for polyurethane foams.

[0017] From the viewpoint of obtaining a flame-retardant rigid polyurethane foam having excellent flame retardancy, the polyester polyol preferably has a hydroxyl value of 100 to 900 mgKOH / g, more preferably 150 to 800 mgKOH / g, and further preferably 180 to 700 mgKOH / g.

[0018] The polyol compound more preferably includes a Mannich polyol, and further preferably includes an aromatic polyester polyol and a Mannich polyol. The inhibition of powder aggregation in the raw material liquid of the polyol composition and the flame-retardant rigid polyurethane foam is mainly due to the action of the dispersant, but by including a Mannich polyol as a polyol compound together with the dispersant, the aggregation of the powder can be inhibited even more effectively.

[0019] The polyol compound may contain, for example, aromatic polyether polyol other than Mannich polyol, in addition to polyester polyol and Mannich polyol. In addition, from the viewpoint of obtaining a rigid polyurethane foam having excellent flame retardancy, it is preferable that the aliphatic polyol is not contained as much as possible. The total content of aromatic polyol in 100 parts by mass of polyol compound is preferably 90 parts by mass or more, more preferably 95 parts by mass or more, and even more preferably 100 parts by mass.

[0020] From the viewpoint of obtaining a flame-retardant rigid polyurethane foam having excellent flame retardancy and appropriate hardness, the total content of the polyol compounds in the polyol composition is preferably 10 to 60 parts by mass, more preferably 20 to 55 parts by mass, and even more preferably 25 to 50 parts by mass, per 100 parts by mass of the polyol composition.

[0021] (Polyester polyol) From the viewpoint of obtaining a flame-retardant rigid polyurethane foam having excellent flame retardancy and appropriate hardness, the polyester polyol is preferably an aromatic polyester polyol, for example, a compound obtained by polycondensation of an aromatic polycarboxylic acid and a polyhydric alcohol, etc. The aromatic polyester polyol may be used alone or in combination of two or more kinds. Specific examples of aromatic polyvalent carboxylic acids include phthalic acid, terephthalic acid, orthophthalic acid, isophthalic acid, trimellitic acid, hemimellitic acid, and pyromellitic acid. Specific examples of polyhydric alcohols include ethylene glycol, propanediol, butanediol, diethylene glycol, dipropylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, bisphenol A, and the like. Examples of aromatic polyester polyols include those obtained by transesterifying polyalkylene terephthalates such as polyethylene terephthalate and polybutylene terephthalate with polyhydric alcohols.

[0022] From the viewpoint of obtaining a rigid polyurethane foam having excellent flame retardancy, it is preferable that the polyol compound contains aromatic polyester polyol in the largest proportion, and the content of aromatic polyester polyol in the polyol compound is preferably 50 parts by mass or more, more preferably 55 to 98 parts by mass, and even more preferably 60 to 95 parts by mass, per 100 parts by mass of the polyol compound.

[0023] (Mannich polyol) The Mannich polyol in the present invention refers to an aromatic polyether polyol obtained by addition polymerization of an alkylene oxide to an aromatic polyol, which is a product (Mannich condensation product) obtained by the Mannich reaction of a phenol compound, an aldehyde compound, and an amine compound. The Mannich polyol may be used alone or in combination of two or more kinds. As the phenol compound, for example, phenol; alkylphenols such as cresol and nonylphenol, and the like are generally used. As the aldehyde compound, for example, formaldehyde, acetaldehyde, etc. are generally used. Examples of the amine compound include aliphatic primary or secondary monoamines. Generally used are alkanolamines such as monoethanolamine, diethanolamine, and 1-amino-2-propanol; and alkylamines such as methylamine and diethylamine. As the alkylene oxide, for example, ethylene oxide, propylene oxide, butylene oxide, etc. are generally used. Specifically, the Mannich polyol can be produced by the production method described in WO 2010 / 147091 and the like.

[0024] When the polyol compound contains a Mannich polyol, the content thereof is preferably 1 to 25 parts by mass, more preferably 2 to 20 parts by mass, and even more preferably 3 to 15 parts by mass, per 100 parts by mass of the polyol compound, from the viewpoints of suppressing the aggregation of powder in the polyol composition and obtaining a rigid polyurethane foam having excellent flame retardancy. From the same viewpoint, the ratio of the content of the Mannich polyol to the content of the aromatic polyester polyol is preferably 0.02 to 1.00, more preferably 0.05 to 0.80, and further preferably 0.08 to 0.50.

[0025] <Powder flame retardant> The powder flame retardant used in the polyol composition of the present invention is a powder flame retardant other than red phosphorus. The polyol composition of the present invention uses a powder flame retardant that is safer to handle than red phosphorus, a conventional powder flame retardant, and can impart excellent flame retardancy to a rigid polyurethane foam, thereby suppressing settling and aggregation of the powder in the raw material liquid of the polyol composition and the flame-retardant rigid polyurethane foam. Here, the powder flame retardant refers to a flame retardant which is solid at 15° C. and 1 atmospheric pressure and which exists as a powder (solid) without dissolving in the polyol composition.

[0026] The powder flame retardant preferably contains at least one selected from phosphates and phosphinates. The phosphates and phosphinates may be used alone or in combination of two or more.

[0027] The phosphate may be an inorganic phosphate or an organic phosphate, and examples thereof include various phosphates of one or more metals or compounds selected from metals of Groups 1 to 14 of the periodic table, ammonia, aliphatic amines, and aromatic amines. Examples of various phosphoric acids include orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, and the like. Also, organic phosphoric acids such as alkyl phosphoric acids may be used. Specific examples of metals include lithium, sodium, calcium, barium, iron, aluminum, titanium, zinc, etc. Specific examples of aliphatic amines include methylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, piperazine, etc. Specific examples of aromatic amines include pyridine, triazine, melamine, etc.

[0028] The phosphinate may be an inorganic phosphinate or an organic phosphinate, and examples thereof include various phosphinates of one or more metals or compounds selected from metals of Groups 1 to 14 of the periodic table, ammonia, aliphatic amines, and aromatic amines. The various phosphinic acids may be phosphinic acids or organic phosphinic acids such as alkylphosphinic acids. Specific examples of metals, aliphatic amines and aromatic amines include those similar to those mentioned above for the phosphates.

[0029] The phosphates and phosphinates may be subjected to a surface treatment such as a silane coupling agent treatment or a melamine coating treatment. From the viewpoint of further improving flame retardancy, the powder flame retardant may contain, in addition to the phosphate and the phosphinate, a component that can act as a flame retardant assistant, and it is preferable that the powder flame retardant contains, for example, a nitrogen-containing compound such as melamine phthalate, melamine cyanurate, or benzoguanamine. When the powder flame retardant contains a nitrogen-containing compound, the content thereof is preferably 200 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 50 parts by mass or less, per 100 parts by mass of the total of the phosphate and the phosphinate.

[0030] The powder flame retardant is preferably used in an amount of 10 to 55 parts by mass, more preferably 15 to 50 parts by mass, and even more preferably 20 to 40 parts by mass, per 100 parts by mass of the polyol composition, from the viewpoint of obtaining a rigid polyurethane foam having excellent flame retardancy.

[0031] <Liquid flame retardant> In addition to the powder flame retardant, the polyol composition preferably contains a liquid flame retardant. Here, the liquid flame retardant refers to a flame retardant that is liquid at 15° C. and 1 atmospheric pressure or that dissolves in the polyol composition. The liquid flame retardant preferably contains a phosphoric acid ester from the viewpoint of the effect of suppressing initial carbonization during heating or combustion of the rigid polyurethane foam.

[0032] The phosphate ester may be a monophosphate ester or a condensed phosphate ester. Examples of monophosphate esters include trimethyl phosphate, triethyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, and also tris(β-chloropropyl) phosphate, which is a halogen-containing phosphate ester. Examples of the condensed phosphate ester include trialkyl polyphosphate, resorcinol bisphenyl phosphate, and bisphenol A bisdiphenyl phosphate.

[0033] When the polyol composition contains a liquid flame retardant, the content thereof is preferably 1 to 50 parts by mass, more preferably 2 to 45 parts by mass, and even more preferably 5 to 40 parts by mass, per 100 parts by mass of the polyol composition, from the viewpoint of the effect of suppressing initial carbonization during heating or combustion of the rigid polyurethane foam.

[0034] <Anti-settling agent> The anti-settling agent has the role of suppressing the settling of powder particles having a large specific gravity, such as a powdery flame retardant, in the polyol composition, and is also called a thixotropic agent. The anti-settling agent acts to suppress the settling of the powder by thickening the polyol composition in a stationary state through the formation of hydrogen bonds in the polyol composition, the formation of crosslinked structures via the adsorption groups of the powder particles, the entanglement of polymer chains, etc. The hydrogen bonds, crosslinked structures, and entanglement of polymer chains are easily released when shear such as stirring is applied, so that the viscosity of the polyol composition and the raw material liquid of the flame-retardant rigid polyurethane foam is not too high during the production of the flame-retardant rigid polyurethane foam, and the workload for uniform mixing is not excessively high.

[0035] The anti-settling agent used in the present invention preferably includes at least one selected from organic bentonite, aliphatic amide wax, and hydrogenated castor oil wax. These may be used alone or in combination of two or more. These anti-settling agents are suitable because they can effectively inhibit the settling of powder even when contained in a small amount in the polyol composition. The content of the anti-settling agent in the polyol composition is preferably 0.01 to 5.00 parts by mass, more preferably 0.02 to 2.00 parts by mass, and even more preferably 0.05 to 1.00 parts by mass, per 100 parts by mass of the polyol composition.

[0036] Carbon black, silica powder, and the like are known as anti-settling agents for red phosphorus, but although they exhibit a thickening effect in a polyol composition using the powder flame retardant, they tend to easily cause powder aggregation. Therefore, it is preferable to use one or more of organic bentonite, aliphatic amide wax, and hydrogenated castor oil wax as the anti-settling agent in the present invention.

[0037] Organic bentonite is an organically modified clay that is modified by ion-exchanging the cations between the crystal layers of the clay mineral montmorillonite with quaternary ammonium ions. Organic bentonite has low hydrophilicity and is difficult to disperse in water, but has high affinity with polyol compounds and exerts an excellent sedimentation suppressing effect on the powder in the polyol composition. Fatty acid amide wax has a long-chain fatty acid group and an amide group in the molecule, and is thermally and chemically stable. Hydrogenated castor oil wax is a triglyceride of saturated fatty acid obtained by hydrogenating refined castor oil. Hydrogenated castor oil wax and fatty acid amide wax are wax-based anti-settling agents, and both have excellent anti-settling effect on powder in the polyol composition.

[0038] <Dispersant> The dispersant plays a role in preventing the powder (solid) particles in the polyol composition from agglomerating, caking, or gelling. In the polyol composition containing the powder flame retardant of the present invention, if only an anti-settling agent as described above is used, it is difficult to uniformly disperse the powder in the raw material liquids of the polyol composition and the flame-retardant rigid polyurethane foam when stirring or the like is performed to mix them during the production of the flame-retardant rigid polyurethane foam, and a rigid polyurethane foam having excellent flame retardancy due to the powder flame retardant cannot be obtained. The polyol composition of the present invention, when used in combination with an anti-settling agent and a dispersant, can effectively suppress the settling and aggregation of powder in the raw material liquid for a flame-retardant rigid polyurethane foam, and by using such a raw material liquid, a rigid polyurethane foam having excellent flame retardancy can be obtained.

[0039] The dispersant in the polyol composition is adsorbed on the surface of the powder particles, and generates distance between the powder particles due to electrical repulsion or steric hindrance, thereby suppressing the aggregation of the powder. By using the dispersant, even if the powder in the polyol composition once settles, the powder can be easily dispersed by re-stirring the polyol composition.

[0040] The dispersant used in the present invention preferably contains at least one selected from organic ammonium salts, phosphoric acid esters, and phosphoric acid ester salts. Examples of organic ammonium salts include alkyl ammonium salts and alkylol ammonium salts. These may be used alone or in combination of two or more. These dispersants are suitable because even if their content in the polyol composition is small, they can effectively suppress the aggregation of powder when used in combination with an anti-settling agent. The content of the dispersant in the polyol composition is preferably 0.05 to 5.00 parts by mass, more preferably 0.10 to 2.00 parts by mass, and further preferably 0.15 to 1.00 parts by mass, per 100 parts by mass of the polyol composition.

[0041] The dispersant is preferably a polymer-type dispersant having a main chain of polyester, polyether, polycarboxylic acid, or the like, and has a group that is easily adsorbed to the powder flame retardant. The organic ammonium salt has a basic group based on a quaternary ammonium group, and the phosphate ester and the phosphate salt have a phosphate ester group.

[0042] <Other ingredients> As the raw materials for producing a flame-retardant rigid polyurethane foam, in addition to the main raw materials, that is, a polyol compound, a flame retardant, and a polyisocyanate compound, it is preferable to compound a blowing agent, a catalyst, a foam stabilizer, etc. These components may be added separately from the polyol composition when producing the flame-retardant rigid polyurethane foam, but from the viewpoint of reducing the workload when applying the flame-retardant rigid polyurethane foam, it is preferable that they are contained in the polyol composition. Furthermore, the polyol composition may contain additives such as a solvent, a filler, a colorant, and an antioxidant, if necessary, within the range that does not impair the effects of the present invention.

[0043] (foaming agent) The foaming agent has the effect of generating gas by heat generated during a resinification reaction in which a polyol compound reacts with a polyisocyanate compound to form a urethane bond, thereby foaming the polyurethane resin. Examples of the blowing agent include hydrofluoroolefins (HFOs), hydrochlorofluoroolefins (HCFOs), hydrofluorocarbons (HFCs), water, etc. These may be used alone or in combination of two or more. Among these, HFOs and HCFOs are blowing agents whose demand is expected to increase in the future in place of HFCs from the viewpoint of preventing global warming, etc., and it is preferable to use these. Specific examples include trans-1,3,3,3-tetrafluoropropene (trans-HFO-1234ze), 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz), trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), etc.

[0044] The isocyanate group of the polyisocyanate compound reacts with water to form a urea bond, and a foaming reaction that generates carbon dioxide gas also occurs. Water induces foaming in the initial stage of the production reaction of the rigid polyurethane foam, and from the viewpoint of reducing the density of the rigid polyurethane foam produced, water may be contained as a foaming agent.

[0045] The amount of the foaming agent to be added is preferably 5.0 to 40.0 parts by mass, more preferably 10.0 to 30.0 parts by mass, and even more preferably 12.0 to 25.0 parts by mass, based on 100 parts by mass of the polyisocyanate compound, from the viewpoint of appropriately foaming the polyurethane resin. In addition, when water is contained as a blowing agent, from the viewpoint of suppressing hydrolysis of the polyol compound, the content of water is preferably less than that of the blowing agents other than water, and is preferably 20.0 parts by mass or less, more preferably 15.0 parts by mass or less, and even more preferably 10.0 parts by mass or less, per 100 parts by mass of the total of the blowing agents other than water.

[0046] (catalyst) In the reaction for producing rigid polyurethane foam, from the viewpoint of promoting the resinification reaction and the foaming reaction, a tertiary amine catalyst, a metal-based urethane catalyst, etc. are preferably used. In addition, from the viewpoint of improving flame retardancy by partial nuration, a nurate catalyst (trimerization catalyst) is also preferably used. As these various catalysts, catalysts known in the production of rigid polyurethane foam can be used. These catalysts may be used alone or in combination of two or more.

[0047] Examples of the tertiary amine catalyst include dimethylethanolamine, triethylenediamine, methyldicyclohexylamine, dimethylcyclohexylamine, pentamethyldiethylenetriamine, bis(2-dimethylaminoethyl)ether, diethylmethylbenzenediamine, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1,4-diazabicyclo[2.2.2]octane, etc. These may be used alone or in combination of two or more. The amount of the tertiary amine catalyst to be added is preferably 0.1 to 10.0 parts by mass, more preferably 0.2 to 8.0 parts by mass, and even more preferably 0.5 to 5.0 parts by mass, per 100 parts by mass of the polyisocyanate compound, from the viewpoint of appropriately promoting the resinification reaction and the foaming reaction of the rigid polyurethane foam.

[0048] Examples of metal-based urethanization catalysts include dibutyltin diacetate, dibutyltin dilaurate, aluminum acetylacetone, zirconium acetylacetone, bismuth 2-ethylhexylate, bismuth neodecanoate, lead naphthenate, lead octylate, zinc naphthenate, zinc octylate, etc. These may be used alone or in combination of two or more. The amount of the metal-based urethane catalyst to be added is preferably 0.01 to 2.0 parts by mass, more preferably 0.02 to 1.0 parts by mass, and even more preferably 0.05 to 0.5 parts by mass, per 100 parts by mass of the polyisocyanate compound, from the viewpoint of appropriately promoting the resinification reaction and the foaming reaction of the rigid polyurethane foam.

[0049] Examples of the nurate catalyst include 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 salts of carboxylates such as potassium acetate and potassium 2-ethylhexylate; tertiary ammonium salts such as trimethylammonium salts, triethylammonium salts, and triphenylammonium salts; and quaternary ammonium salts such as tetramethylammonium salts, tetraethylammonium, and tetraphenylammonium salts. These may be used alone or in combination of two or more. The amount of the nurate catalyst to be added is preferably 0.1 to 10.0 parts by mass, more preferably 0.2 to 8.0 parts by mass, and even more preferably 0.5 to 5.0 parts by mass, relative to 100 parts by mass of the polyisocyanate compound, from the viewpoint of appropriately promoting the nurate reaction of isocyanate.

[0050] (Foam stabilizer) The foam stabilizer is added from the viewpoint of obtaining a homogeneous flame-retardant rigid polyurethane foam, and any foam stabilizer known in the art for producing rigid polyurethane foams can be used. In general, silicone-based foam stabilizers are preferably used, such as siloxane-polyalkylene oxide copolymers. The amount of the foam stabilizer to be added is appropriately set depending on the type of polyurethane resin to be produced, but is preferably 0.1 to 10.0 parts by mass, more preferably 0.2 to 8.0 parts by mass, and even more preferably 0.5 to 5.0 parts by mass, relative to 100 parts by mass of the polyisocyanate compound.

[0051] <Method of producing polyol composition> The method for producing the polyol composition of the present invention is not particularly limited, and the polyol composition can be produced by blending the above-mentioned components contained in the polyol composition and stirring and mixing them using a known stirring device such as a homodisper or a planetary stirrer.

[0052] [Flame-retardant rigid polyurethane foam] The flame-retardant rigid polyurethane foam of the present invention is a reaction product of the polyol composition and a polyisocyanate compound. When a polyol composition in which the powder is not sufficiently uniformly dispersed is used, it is difficult to obtain a homogeneous rigid polyurethane foam having excellent flame retardancy overall. In contrast, according to the polyol composition of the present invention, as described above, even if the polyol composition contains a powder flame retardant having a large specific gravity, the settling and aggregation of the powder in the raw material liquid of the polyol composition and the flame-retardant rigid polyurethane foam can be effectively suppressed. Therefore, when producing a flame-retardant rigid polyurethane foam, the workload of stirring and the like for uniformly mixing the polyol composition and the raw material liquid of the flame-retardant rigid polyurethane foam can be reduced, and the uniform dispersion of the powder in the raw material liquid can be improved. In addition, the produced flame-retardant rigid polyurethane foam is obtained as one having excellent flame retardancy due to the powder flame retardant.

[0053] <Polyisocyanate compounds> The polyisocyanate compound is an isocyanate compound having two or more isocyanate groups, and produces a polyurethane resin by a polyaddition reaction with a polyol compound. The polyisocyanate compound may be either an aromatic polyisocyanate or an aliphatic polyisocyanate, and one of these may be used alone, or two or more of them may be used in combination.

[0054] Examples of aromatic polyisocyanates include diphenylether-2,4'-diisocyanate, diphenylether-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, 4,6-dimethyl-1,3-phenylene diisocyanate, monomeric MDI such as 2,2'-diphenylmethane diisocyanate (2,2'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), and 4,4'-diphenylmethane diisocyanate (4,4'-MDI), polymethylene polyphenyl polyisocyanate (crude MDI or polymeric MDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate, and m-xylylene diisocyanate. The aliphatic polyisocyanate may be either an acyclic or an alicyclic polyisocyanate, and examples thereof include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate. Of these, from the viewpoints of reactivity and the flame retardancy of the produced rigid polyurethane foam, preferably, monomeric MDI such as 2,2'-MDI, 2,4'-MDI or 4,4'-MDI, crude MDI or polymeric MDI is used, and further, from the viewpoints of availability, cost, etc., crude MDI or polymeric MDI is more preferably used.

[0055] The amount of the polyisocyanate compound in the raw material liquid for the flame-retardant rigid polyurethane foam is appropriately set depending on the type of polyisocyanate compound, but from the viewpoints of sufficient reactivity with the polyol compound, ease of handling during mixing of the raw material liquid, and the like, the amount is preferably 50 to 200 parts by mass, more preferably 70 to 150 parts by mass, and even more preferably 80 to 120 parts by mass, per 100 parts by mass of the polyol composition.

[0056] <Method for producing flame-retardant rigid polyurethane foam> In the method for producing a flame-retardant rigid polyurethane foam of the present invention, the polyol composition and a polyisocyanate compound are mixed, foamed and cured to obtain a flame-retardant rigid polyurethane foam. The foaming and curing method for obtaining the flame-retardant rigid polyurethane foam is not particularly limited, and for example, known methods such as various moldings such as slab molding, mold molding, laminate molding, injection molding, spray foaming, etc. can be applied. In these various foaming and curing methods, a raw material liquid for the flame-retardant rigid polyurethane foam, which is a mixture of the polyol composition and the polyisocyanate compound, is foamed and cured, whereby a homogeneous rigid polyurethane foam having excellent flame retardancy overall can be produced.

[0057] As described above, the polyol composition suppresses the settling and aggregation of the powder contained therein, and therefore, when the polyol composition is mixed with a polyisocyanate compound, the powder can be easily and uniformly dispersed without requiring a large shear force, for example, by using a general stirrer equipped with a stirring blade, etc. Therefore, by using the polyol composition, the raw material liquid can be mixed with a small workload, and the efficiency of production of a rigid polyurethane foam having excellent flame retardancy can be improved. EXAMPLES

[0058] The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

[0059] [Preparation of polyol composition] Details of each raw material used in the preparation of the polyol compositions in the following Examples and Comparative Examples are shown below. <Polyol compound> Polyester polyol (RFK-556): Terephthalic acid-based polyester polyol; "Maximol (registered trademark) RFK-556", manufactured by Kawasaki Kasei Chemical Industries, Ltd.; hydroxyl value 224 mg KOH / g Mannich polyol (NB-622): "Exenol (registered trademark) NB-622", manufactured by AGC Corporation, hydroxyl value 500 mg KOH / g <Powder flame retardant> Phosphinic acid salt (CM-6R): "Furan CM-6R", manufactured by Yamato Chemical Industry Co., Ltd.; nitrogen-containing compound Phosphate (R1910-4); "Non-Nen (registered trademark) R1910-4" manufactured by Marubishi Yuka Kogyo Co., Ltd.; nitrogen-containing compound Red phosphorus: "Nova Excel (registered trademark) 140", manufactured by Rinkagaku Kogyo Co., Ltd. <Liquid flame retardant> Halogen-containing phosphate ester (TMCPP): Tris(β-chloropropyl)phosphate; "TMCPP", manufactured by Daihachi Chemical Industry Co., Ltd. <Anti-settling agent> Organic bentonite (BENTONE 38); "BENTONE® 38", manufactured by Elementis Specialties, Inc., powder Fatty acid amide wax (PFA-131); "Disparlon PFA-131", manufactured by Kusumoto Chemicals Co., Ltd.; active ingredient 10% by weight Hydrogenated castor oil wax (SN Thickener 4040); "SN Thickener 4040", manufactured by San Nopco Ltd. <Dispersant> Organic ammonium salt (BYK-2155): "DISPERBYK (registered trademark; hereinafter the same)-2155", BYK Japan Co., Ltd.; block copolymer having basic groups Alkylol ammonium salt (BYK-180): "DISPERBYK-180", BYK Japan Co., Ltd.; Alkylol ammonium salt of copolymer containing acid group Phosphate ester (BYK-111): "DISPERBYK-111", BYK Japan Co., Ltd.; Phosphate ester with phosphate groups at both ends of the copolymer Phosphate ester salt (BYK-145): "DISPERBYK-145", BYK Japan Co., Ltd.; Copolymer of phosphate ester salt <Foaming agent> HCFO (LBA): trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd); "Solstice (registered trademark) LBA", manufactured by Honeywell International, Inc. <Catalyst> Tertiary amine catalyst (KL-120); 1-isobutyl-2-methylimidazole; "Kao Raiser (registered trademark) No. 120", manufactured by Kao Corporation Metal-based urethane catalyst (DINP17); Lead octoate; "Nikka Octix (registered trademark) Lead 17% DINP", manufactured by Nippon Kagaku Sangyo Co., Ltd.; Pb content 17% by mass Nurate catalyst (U-18X); Triethylmethylammonium 2-ethylhexane salt; "U-CAT 18X", manufactured by San-Apro Co., Ltd. <Foam stabilizer> L-6100: Silicone foam stabilizer; "Niax(R) silicone L-6100", manufactured by Momentive Performance Materials, Inc.

[0060] Example 1 A 500 mL plastic bottle was charged with 28.04 parts by mass of polyester polyol RFK-556 as a polyol compound, 1.26 parts by mass of KL-120, 0.14 parts by mass of DINP17, and 3.78 parts by mass of U-18X as catalysts, 20.16 parts by mass of liquid flame retardant TMCPP, and 1.4 parts by mass of foam stabilizer L-6100, and the mixture was stirred at 3000 rpm for 20 seconds with an electric drill fitted with a cage attachment (the stirring method was the same below). To this, 30.0 parts by mass of powder flame retardant CM-6R, 0.76 parts by mass of anti-settling agent BENTONE 38, and 0.46 parts by mass of dispersant BYK-2155 were added and stirred for 20 seconds, and then 14.0 parts by mass of foaming agent (HCFO) LBA was added and stirred for another 20 seconds, and then the mixture was kept warm in a thermostatic water bath at 20°C to prepare a polyol composition.

[0061] (Examples 2 to 15, Comparative Examples 1 to 11) Polyol compositions were prepared in the same manner as in Example 1 using the raw material blend compositions shown in Table 1 or Table 2 below.

[0062] [Production of rigid polyurethane foam] 100 parts by mass of each polyol composition prepared in each of the above Examples and Comparative Examples was stirred at 15°C, and placed in a 1 L descup together with 90 parts by mass of polymethylene polyphenyl polyisocyanate (Polymeric MDI: "Millionate (registered trademark) MR-200", manufactured by Tosoh Corporation) as a polyisocyanate compound, and mixed and foamed for 5 seconds. After standing for 30 minutes, the cured product was removed from the descup to obtain a rigid polyurethane foam.

[0063] [evaluation] The polyol compositions prepared in the above Examples and Comparative Examples and the rigid polyurethane foams produced using the same were evaluated for the following items. The evaluation results are shown in Tables 1 and 2 below.

[0064] <Sedimentation> A 50 mL vial containing 30 g of the polyol composition was left to stand at room temperature (25° C.) By visual observation, the height position (based on the liquid level) of the upper surface of the powder (solid) sediment after one day was measured. These measured values ​​were evaluated based on the following evaluation criteria. (Evaluation Criteria) AA: The height of the top surface of the sediment is less than 1 mm from the liquid surface. A: The height of the top surface of the sediment is 1mm or more but less than 3mm above the liquid surface. B: The height of the top surface of the sediment is 3 mm or more but less than 5 mm above the liquid surface. C: The height of the top surface of the sediment is 5 mm or more above the liquid surface. In the case of the evaluation AA, it can be considered that almost no sedimentation has occurred. In the cases of the evaluations A and B, the sedimentation has occurred to some extent, but it can be said that the sedimentation has been well suppressed. In the case of the evaluation C, the sedimentation has occurred significantly, and the polyol composition was judged to be unsuitable for practical use.

[0065] <Cohesiveness> The state of sediment in the above evaluation of <sedimentation property> was visually observed and evaluated based on the following evaluation criteria. (Evaluation Criteria) AA: When the vial is turned on its side, the sediment flows and when it is stood upright again, it returns to its original state within 5 minutes. A: If you turn the vial on its side, the sediment will move, and if you stand it upright again, it will gradually return to its original state. Even if you leave it still for 5 minutes, the sediment will not return to its original state completely, but it will not adhere to the inner wall of the vial. B: When the vial is turned on its side, the sediment flows, and when it is turned upright again, it gradually returns to its original state. Even after being left to stand for 5 minutes, the sediment does not return to its original state completely, and some deposits remain on the inner wall of the vial. C: The sediment does not flow even when the vial is turned on its side. In the case of the evaluation AA, the powder aggregation suppression effect is particularly excellent, and in the cases of the evaluations A and B, the powder aggregation is suppressed well. On the other hand, in the case of the evaluation C, the aggregation suppression effect was not sufficient, and the polyol composition was judged to be unsuitable for practical use.

[0066] <Flame retardancy> A sample of 98 mm×98 mm×thickness (height) 25 mm was cut out from the rigid polyurethane foam produced above. In accordance with ISO 5660-1, a cone calorimeter ("Cone Calorimeter III", manufactured by Toyo Seiki Seisakusho Co., Ltd.; non-combustible base material: gypsum board (thickness 12.5 mm)) was used to measure 50KW / m 2The heat quantity was applied to the sample, and at the same time, ignition was performed for 10 seconds using an ignition plug. The total heat generation amount after heating for 20 minutes was measured. These measured values ​​were evaluated based on the following evaluation criteria. (Evaluation Criteria) A: Total calorific value 8MJ / m 2 less than B: Total heat output 8MJ / m 2 More than 11MJ / m 2 less than C: Total heat output 11MJ / m 2 More than 20MJ / m 2 less than D: Total heat output 20MJ / m 2 End In the case of rating A, the material has the highest flame retardancy and can be called a non-combustible material. In the case of rating B, the material also has a sufficiently high flame retardancy and can be called a semi-non-combustible material. In the cases of rating C or D, the material was judged to not have sufficient flame retardancy.

[0067] [Table 1]

[0068] [Table 2]

[0069] As can be seen from the results shown in Tables 1 and 2, it was found that the polyol compositions (Examples 1 to 15) in which an anti-settling agent and a dispersant were blended with a polyol composition containing a powder flame retardant suppressed the settling and aggregation of the powder and produced rigid polyurethane foams having flame retardancy equivalent to or greater than that of semi-noncombustible materials. On the other hand, when no anti-settling agent and / or dispersant was added (Comparative Examples 1 to 5), or when red phosphorus was used as the powder flame retardant (Comparative Examples 6 to 11), no polyol composition was obtained that showed good evaluation results in terms of the powder settling inhibition effect and aggregation inhibition effect, and the flame retardancy of the rigid polyurethane foam.

Claims

1. A polyol composition for use in the production of a flame-retardant rigid polyurethane foam, comprising a polyol compound, a powder flame retardant other than red phosphorus, an anti-settling agent, and a dispersant, The powder flame retardant contains at least one selected from a phosphate and a phosphinate, The anti-settling agent is at least one selected from organic bentonite, aliphatic amide wax, and hydrogenated castor oil wax; The dispersant is at least one selected from organic ammonium salts, phosphoric acid esters, and phosphoric acid ester salts. Polyol composition.

2. The polyol composition of claim 1 , wherein the polyol compound comprises a Mannich-type polyol.

3. The polyol composition according to claim 1 or 2, further comprising a blowing agent.

4. The polyol composition according to claim 3, wherein the blowing agent comprises at least one selected from hydrofluoroolefins and hydrochlorofluoroolefins.

5. The polyol composition according to any one of claims 1 to 4, further comprising a catalyst.

6. The polyol composition according to any one of claims 1 to 5, further comprising a foam stabilizer.

7. A flame-retardant rigid polyurethane foam which is a reaction product of the polyol composition according to any one of claims 1 to 6 and a polyisocyanate compound.

8. A method for producing a flame-retardant rigid polyurethane foam, comprising mixing the polyol composition according to any one of claims 1 to 6 with a polyisocyanate compound, and foaming and curing the mixture to obtain a flame-retardant rigid polyurethane foam.

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