Polyol composition for production of flame-retardant polyurethane foam, and flame-retardant polyurethane foam

Abstract

To provide: a polyol composition that enables production of polyurethane foam having high flame retardancy and excellent mechanical properties; and polyurethane foam having high flame retardancy and excellent mechanical properties.SOLUTION: Provided is a polyol composition for production of flame-retardant polyurethane foam, comprising a bromine atom-containing polyol and a phosphate ester, wherein the weight ratio of the bromine atom contained in the polyol composition is 1-35 wt.%, the weight ratio of the phosphate ester contained in the polyol composition is 1-35 wt.%, and the total weight ratio of the bromine atom and the phosphate ester contained in the polyol composition is 8-35 wt.%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyol composition for producing a flame-retardant polyurethane foam and a flame-retardant polyurethane foam. [Background technology]

[0002] Polyurethane foam is used in a wide range of applications, including as insulation for building materials, refrigerators, freezers, etc., as well as structural materials and spray coatings for on-site construction, due to its insulating properties, dimensional stability at low temperatures, and ease of application. Depending on the application, these polyurethane foams are required to have not only mechanical strength but also strict flame retardancy. To meet this requirement, studies have been conducted to improve the flame retardancy of polyurethane foams by incorporating a flame retardant into the polyurethane foam or using a brominated polyol as a raw material polyol. For example, Patent Document 1 discloses a rigid polyurethane foam composed of a reaction product of a polyol composition containing a brominated polyol and a bromine-free aromatic polyester polyol, a foam stabilizer, a catalyst, a blowing agent, and a flame retardant, and an isocyanate composition. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-214651 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if flame retardants are used in excess of a certain amount, the mechanical properties (such as compressive strength) of polyurethane foam deteriorate, and achieving both flame retardancy and mechanical properties has been an issue. An object of the present invention is to provide a polyol composition capable of producing a polyurethane foam having high flame retardancy and excellent mechanical properties, and to provide a polyurethane foam having high flame retardancy and excellent mechanical properties. [Means for solving the problem]

[0005] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention. That is, the present invention provides a polyol composition for producing a flame-retardant polyurethane foam, which contains a bromine atom-containing polyol and a phosphoric acid ester, wherein the weight ratio of bromine atoms contained in the polyol composition is 1 to 35 wt % based on the weight of the polyol composition, the weight ratio of phosphoric acid ester contained in the polyol composition is 1 to 35 wt % based on the weight of the polyol composition, and the total weight ratio of the weight ratio of bromine atoms and the weight ratio of phosphoric acid ester contained in the polyol composition is 8 to 35 wt % based on the weight of the polyol composition; a flame-retardant polyurethane foam obtained by reacting a polyol composition for producing a flame-retardant polyurethane foam with a polyisocyanate, wherein the weight percentage of bromine atoms contained in the polyurethane foam is 0.5 to 20% by weight based on the weight of the polyurethane foam, the weight percentage of phosphate ester contained in the polyurethane foam is 0.5 to 20% by weight based on the weight of the polyurethane foam, and the total weight percentage of the weight percentage of bromine atoms and the weight percentage of phosphate ester contained in the polyurethane foam is 4 to 20% by weight based on the weight of the polyurethane foam. [Effects of the Invention]

[0006] The polyol composition for producing a flame-retardant polyurethane foam of the present invention can produce a polyurethane foam having high flame retardancy and excellent mechanical properties. The flame-retardant polyurethane foam of the present invention also has high flame retardancy and excellent mechanical properties. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present invention will be described in detail below. The present invention relates to a polyol composition for producing a flame-retardant polyurethane foam, which contains a bromine atom-containing polyol and a phosphate ester. Examples of the bromine atom-containing polyol include aromatic bromine atom-containing polyols and aliphatic bromine atom-containing polyols.

[0008] Examples of aromatic bromine atom-containing polyols include aromatic bromine atom-containing polyester polyols and aromatic bromine atom-containing polyether polyols. As the aromatic bromine atom-containing polyester polyol, for example, a product obtained by an esterification reaction between a bromine atom-containing polycarboxylic acid such as tetrabromophthalic acid and a polyhydric alcohol can be used. Examples of polyhydric alcohols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose, and bisphenol A. These may be used alone or in appropriate combination of two or more.

[0009] Examples of aromatic bromine atom-containing polyether polyols that can be used include those obtained by addition polymerization of a bromine atom-containing polyol such as tetrabromobisphenol A with one or more alkylene oxides (AO) such as ethylene oxide, propylene oxide, and butylene oxide. When a bromine atom-containing polyether polyol is used, it is particularly preferable to use an aromatic bromine atom-containing polyether polyol having a tetrabromobisphenol A skeleton.

[0010] Examples of the aliphatic bromine atom-containing polyol include aliphatic bromine atom-containing polyether polyols and aliphatic bromine atom-containing polyester polyols, and among these, aliphatic bromine atom-containing polyether polyols are preferred.

[0011] From the viewpoint of improving flame retardancy, the bromine atom-containing polyol is preferably an aromatic bromine atom-containing polyol, more preferably a compound in which at least one bromine atom is directly bonded to an aromatic ring, and particularly preferably an oxyalkylene ether of tetrabromobisphenol A or an oxyalkylene ether of tetrabromophthalic acid.

[0012] The hydroxyl value of the bromine atom-containing polyol is preferably from 50 to 400 mgKOH / g, more preferably from 80 to 350 mgKOH / g, and even more preferably from 100 to 300 mgKOH / g.

[0013] The polyol may include polyols other than the bromine atom-containing polyol. Examples of other polyols include polyhydric alcohols, polyether polyols, and polyester polyols. Examples of polyhydric alcohols include dihydric alcohols having 2 to 20 carbon atoms [aliphatic diols (ethylene glycol, propylene glycol, 1,3- or 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, etc.), alicyclic diols (cyclohexanediol, cyclohexanedimethanol, etc.)]; trihydric alcohols having 3 to 20 carbon atoms [aliphatic triols (glycerin, trimethylolpropane, trimethylolethane, hexanetriol, etc.)]; tetrahydric to octahydric or higher polyhydric alcohols having 5 to 20 carbon atoms [aliphatic polyols (pentaerythritol, sorbitol, mannitol, etc.), intramolecular dehydration products of aliphatic polyols (sorbitan, etc.), intermolecular dehydration products of aliphatic polyols (diglycerin, dipentaerythritol, etc.)]; and sugars and derivatives thereof (sucrose, glucose, mannose, fructose, methyl glucoside, etc.). Examples of polyether polyols include AO adducts of active hydrogen-containing compounds (such as the above-mentioned polyhydric alcohols, polyhydric phenols, ammonia, amines, carboxylic acids, and phosphoric acids) and mixtures thereof. Examples of AO include the same as those described above, and preferred embodiments are also the same. Examples of polyester polyols include condensation reaction products of the above polyhydric alcohols and / or the above polyether polyols with polycarboxylic acids, reaction products of the above polyhydric alcohols and / or the above polyether polyols with carboxylic acid anhydrides, and AO adducts thereof. These polyols may be used alone or in combination of two or more.

[0014] The polyol composition for producing a flame-retardant polyurethane foam of the present invention contains a phosphoric acid ester. Examples of the phosphate ester include phosphate monoester, phosphate diester, phosphate triester, and mixtures thereof. The phosphate ester also includes condensed phosphate ester. Examples of phosphoric acid monoesters and phosphoric acid diesters include mono- or diesters of C1-24 monoalcohols and phosphoric acid (mono- or dimethyl phosphate, mono- or diethyl phosphate, mono- or diisopropyl phosphate, mono- or dibutyl phosphate, mono- or di-(2-ethylhexyl) phosphate, mono- or diisodecyl phosphate, oleyl phosphate, stearyl phosphate, etc.), and mono- or diesters of phenols and phosphoric acid (mono- or diphenyl phosphate, mono- or dicresyl phosphate, mono- or dixylenyl phosphate, etc.).

[0015] Examples of the phosphoric acid triester include trialkyl phosphates (trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, trioctyl phosphate), triaryl phosphates (triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, hydroxylphenyl diphenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, isopropylphenyl diphenyl phosphate, bis-(isopropylphenyl)phenyl phosphate, tris-(isopropylphenyl)phosphate), and tris(1-chloro-2-propyl)phosphate; and aromatic condensed phosphoric acid ester compounds which are reaction products of phosphorus oxychloride, a dihydric phenolic compound, and a phenol (or an alkylphenol) [resorcinol bis-diphenyl phosphate, resorcinol bis-dixylenyl phosphate, bisphenol A bis-diphenyl phosphate, etc.].

[0016] Of these, trialkyl phosphate, triaryl phosphate, and condensed phosphate ester are preferred from the viewpoint of improving flame retardancy and viscosity, and triethyl phosphate and tris(1-chloro-2-propyl) phosphate are more preferred.

[0017] The weight percentage of bromine atoms contained in the polyol composition for producing a flame-retardant polyurethane foam of the present invention is 1 to 35 wt % based on the weight of the polyol composition. If the weight percentage of bromine atoms contained in the polyol composition is less than 1 wt % based on the weight of the polyol composition, the flame retardancy of the resulting polyurethane foam will be insufficient, and if it exceeds 35 wt % based on the weight of the polyol composition, the mechanical properties (compressive strength) of the resulting polyurethane foam will deteriorate. From the viewpoint of achieving both flame retardancy and mechanical properties of the resulting polyurethane foam, the weight proportion of bromine atoms contained in the polyol composition is preferably 1 to 15% by weight based on the weight of the polyol composition.

[0018] The weight proportion of bromine atoms contained in the polyol composition can be adjusted by the weight proportion of bromine atom-containing polyol contained in the polyol.

[0019] The weight percentage of bromine atoms contained in the polyol composition can be calculated from the blending ratio of each raw material when the polyol composition is produced. If the blending ratio is unknown, it is measured by the method specified in JIS K7392 (2009 edition).

[0020] The weight proportion of the phosphate ester contained in the polyol composition for producing a flame-retardant polyurethane foam of the present invention is 1 to 35 wt % based on the weight of the polyol composition. If the weight proportion of the phosphate ester contained in the polyol composition is less than 1 wt % based on the weight of the polyol composition, the flame retardancy of the resulting polyurethane foam will be insufficient, and if it exceeds 35 wt % based on the weight of the polyol composition, the mechanical properties (compressive strength) of the resulting polyurethane foam will deteriorate. From the viewpoint of achieving both flame retardancy and mechanical properties of the resulting polyurethane foam, the weight proportion of the phosphate ester contained in the polyol composition is preferably 1 to 15% by weight based on the weight of the polyol composition.

[0021] The weight proportion of the phosphate ester contained in the polyol composition can be calculated from the blending ratio of each raw material when the polyol composition is produced. If the blending ratio is unknown, it can be measured by analysis using gas chromatography mass spectrometry (GC-MS).

[0022] The total weight percentage of the bromine atoms and the phosphate ester contained in the polyol composition for producing a flame-retardant polyurethane foam of the present invention is 8 to 35% by weight based on the weight of the polyol composition. If the total weight percentage of the bromine atoms and the phosphate ester contained in the polyol composition is less than 8% by weight based on the weight of the polyol composition, the flame retardancy of the resulting polyurethane foam will be insufficient, and if it exceeds 35% by weight based on the weight of the polyol composition, the mechanical properties (compressive strength) of the resulting polyurethane foam will deteriorate. From the viewpoint of achieving both flame retardancy and mechanical properties of the resulting polyurethane foam, the total weight proportion of the weight proportion of bromine atoms and the weight proportion of phosphate ester contained in the polyol composition is preferably 10 to 30% by weight based on the polyol composition.

[0023] The polyol composition for producing a flame-retardant polyurethane foam of the present invention may contain, in addition to the polyol and the phosphate ester, a catalyst, a blowing agent, a foam stabilizer, a flame retardant, and other auxiliaries, as necessary. Any catalyst that promotes a urethanization reaction can be used as the catalyst. From the viewpoint of moldability, however, preferred catalysts include tertiary amines {triethylenediamine, N-ethylmorpholine, N,N-dimethylaminoethanol, bisdimethylaminoethyl ether, N-(N',N',-2-dimethylaminoethyl)morpholine, etc.} and metal carboxylates (potassium acetate, potassium octoate, stannous octoate, dibutyl stannous dilaurate, lead octoate, etc.). Among these, triethylenediamine, stannous octoate and dibutyl stannic dilaurate are preferred from the viewpoints of foam hardness and rebound resilience.

[0024] From the viewpoint of moldability, the amount of catalyst used is preferably 0.01 to 5% by weight, more preferably 0.05 to 2% by weight, based on the weight of the polyol composition. One type of catalyst may be used alone, or two or more types may be used in combination.

[0025] As the foam stabilizer, known foam stabilizers (such as silicone-based foam stabilizers and non-silicone-based foam stabilizers) used in the production of polyurethane foams can be used, and examples thereof include commercially available foam stabilizers such as "SZ-1959," "SF-2904," "SZ-1142," "SZ-1720," "SZ-1675t," "SF-2936F," "SZ-3601," "SRX-294A," and "SH-193" manufactured by Dow Corning Toray Co., Ltd., "L-540" and "L-3601" manufactured by Nippon Unicar Co., Ltd., "L-595," "L-598," and "L-626" manufactured by Momentive Performance Materials, Inc., and "B8715 LF2" manufactured by Evonik Degussa Japan Co., Ltd.

[0026] The amount of the foam stabilizer used is preferably 0.4 to 5% by weight, more preferably 0.4 to 3% by weight, based on the weight of the polyol composition, from the viewpoints of moldability and impact resilience. One type of foam stabilizer may be used alone, or two or more types may be used in combination.

[0027] Examples of the foaming agent include water, liquefied carbon dioxide gas, and low-boiling compounds having a boiling point of -5 to 70°C. Examples of low-boiling compounds include hydrogen atom-containing halogenated hydrocarbons and low-boiling hydrocarbons. Specific examples of hydrogen atom-containing halogenated hydrocarbons and low-boiling hydrocarbons include methylene chloride, HCFCs (hydrochlorofluorocarbons) (HCFC-123, HCFC-141b, HCFC-142b, etc.), HFCs (hydrofluorocarbons) (HFC-134a, HFC-152a, HFC-356mff, HFC-236ea, HFC-245ca, HFC-245fa, HFC-365mfc, etc.), HFOs (hydrofluoroolefins) (HFO-1336mzz, HFO-1224yd, HFO-1233zd, etc.), butane, pentane, and cyclopentane. Of these, from the viewpoint of moldability, it is preferable to use water, liquefied carbon dioxide gas, methylene chloride, cyclopentane, HCFC-141b, HFC-134a, HFC-356mff, HFC-236ea, HFC-245ca, HFC-245fa, HFC-365mfc, HFO-1336mzz, HFO-1224yd, HFO-1233zd, and mixtures of two or more of these as the blowing agent.

[0028] The amount of water used as a blowing agent is preferably 1.0 to 8% by weight, more preferably 1.5 to 4% by weight, based on the weight of the polyol composition, from the viewpoint of foam density. From the viewpoint of moldability, the amount of the low boiling point compound used is preferably 50% by weight or less, and more preferably 5 to 45% by weight, based on the weight of the polyol composition. The amount of liquefied carbon dioxide gas used is preferably 30% by weight or less, more preferably 1 to 25% by weight, based on the weight of the polyol composition.

[0029] The flame retardant referred to here refers to a flame retardant other than the bromine atom-containing polyol and phosphate ester, such as melamine and phosphazene. The amount of the flame retardant used is preferably 0.01 to 5% by weight, more preferably 0.05 to 3% by weight, based on the weight of the polyol composition, from the viewpoint of the viscosity (operability) of the polyol composition.

[0030] Other auxiliaries include known auxiliary components such as colorants (dyes and pigments), plasticizers (phthalates, adipates, etc.), organic fillers (synthetic short fibers, hollow microspheres made of thermoplastic or thermosetting resins, etc.), antioxidants (triazoles, benzophenones, etc.), and antioxidants (hindered phenols, hindered amines, etc.).

[0031] The amount of these auxiliaries added is preferably 1% by weight or less for the colorant, 10% by weight or less for the plasticizer, and more preferably 5% by weight or less for the organic filler. The amount of the antioxidant is preferably 1% by weight or less, and more preferably 0.01 to 0.5% by weight. The amount of the antioxidant is preferably 1% by weight or less, and more preferably 0.01 to 0.5% by weight. The total amount of auxiliaries used is preferably 50% by weight or less, and more preferably 0.2 to 30% by weight, based on the weight of the polyol composition.

[0032] The flame-retardant polyurethane foam of the present invention is a flame-retardant polyurethane foam obtained by reacting the polyol composition for producing a flame-retardant polyurethane foam with a polyisocyanate. The polyisocyanate may be any compound having two or more isocyanate groups in the molecule, and any known compound used in the production of polyurethane foams may be used. Specific examples include aromatic polyisocyanates, linear or branched aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, and modified products thereof. As the polyisocyanate, one type may be used, or two or more types may be used in combination.

[0033] Examples of aromatic polyisocyanates include aromatic diisocyanates having 6 to 16 carbon atoms (excluding carbon atoms in NCO groups; the same applies to the following polyisocyanates), aromatic triisocyanates having 6 to 20 carbon atoms, and crude products of these isocyanates. Specific examples include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (hereinafter abbreviated as TDI), crude TDI, 2,4'- or 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI), polymethylene polyphenylene polyisocyanate (crude MDI), naphthylene-1,5-diisocyanate, and triphenylmethane-4,4',4''-triisocyanate.

[0034] Examples of linear or branched aliphatic polyisocyanates include aliphatic diisocyanates having 6 to 10 carbon atoms. Specific examples include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate.

[0035] Examples of alicyclic polyisocyanates include alicyclic diisocyanates having 6 to 16 carbon atoms, such as isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, and norbornane diisocyanate.

[0036] Examples of the araliphatic polyisocyanate include araliphatic diisocyanates having a carbon number of 8 to 12. Specific examples include xylylene diisocyanate and α,α,α',α'-tetramethylxylylene diisocyanate.

[0037] These modified products include modified products of the above-mentioned various isocyanates (e.g., modified products containing a urethane group, a carbodiimide group, an allophanate group, a urea group, a biuret group, an isocyanurate group, and an oxazolidone group), and specific examples of modified polyisocyanates include urethane-modified MDI, urethane-modified TDI, carbodiimide-modified MDI, and carbodiimide-modified TDI.

[0038] From the viewpoint of reactivity, the polyisocyanate is preferably an aromatic polyisocyanate or a modified product thereof, more preferably at least one selected from the group consisting of TDI, crude TDI, MDI, crude MDI, and modified products of these isocyanates, and particularly preferably at least one selected from the group consisting of TDI, MDI, and crude MDI.

[0039] The weight percentage of bromine atoms contained in the flame-retardant polyurethane foam of the present invention is 0.5 to 20% by weight based on the weight of the polyurethane foam. If the weight percentage of bromine atoms contained in the polyurethane foam is less than 0.5% by weight based on the weight of the polyol composition, the polyurethane foam will have insufficient flame retardancy, while if it exceeds 20% by weight based on the weight of the polyurethane foam, the mechanical properties (compressive strength) of the polyurethane foam will deteriorate. From the viewpoint of achieving both flame retardancy and mechanical properties of the polyurethane foam, the weight proportion of bromine atoms contained in the polyurethane foam is preferably 0.5 to 8% by weight based on the weight of the polyurethane foam.

[0040] The weight percentage of bromine atoms contained in the polyurethane foam can be calculated from the blending ratio of each raw material when producing the polyurethane foam. If the blending ratio is unknown, it can be measured by the method specified in JIS K7392 (2009 edition).

[0041] The weight percentage of the phosphate ester contained in the flame-retardant polyurethane foam of the present invention is 0.5 to 20% by weight based on the weight of the polyurethane foam. If the weight percentage of the phosphate ester contained in the polyurethane foam is less than 0.5% by weight based on the weight of the polyurethane foam, the flame retardancy of the polyurethane foam will be insufficient, and if it exceeds 20% by weight based on the weight of the polyurethane foam, the mechanical properties (compression strength) of the polyurethane foam will deteriorate. From the viewpoint of achieving both flame retardancy and mechanical properties of the polyurethane foam, the weight proportion of the phosphate ester contained in the polyurethane foam is preferably 4 to 15% by weight based on the weight of the polyurethane foam.

[0042] The weight percentage of phosphate ester contained in polyurethane foam can be calculated from the blending ratio of each raw material when making the polyurethane foam. If the blending ratio is unknown, it can be measured by analyzing it using gas chromatography-mass spectrometry (GC-MS).

[0043] The total weight percentage of the bromine atoms and the phosphate ester contained in the flame-retardant polyurethane foam of the present invention is 4 to 20% by weight based on the weight of the polyurethane foam. If the total weight percentage of the bromine atoms and the phosphate ester contained in the polyurethane foam is less than 4% by weight based on the weight of the polyurethane foam, the flame retardancy of the polyurethane foam will be insufficient, and if it exceeds 35% by weight based on the weight of the polyurethane foam, the mechanical properties (compressive strength) of the polyurethane foam will deteriorate. From the viewpoint of achieving both flame retardancy and mechanical properties of the polyurethane foam, it is preferable that the total weight proportion of the bromine atoms and the phosphate ester contained in the polyurethane foam is 5 to 15 weight % based on the weight of the polyurethane foam.

[0044] The flame-retardant polyurethane foam of the present invention can be produced, for example, by a production method including a step of reacting a polyol composition with a polyisocyanate in the presence of a catalyst and a blowing agent (foam-forming step). When the polyol composition is reacted with the polyisocyanate, one or more of a foam stabilizer, a flame retardant, and other additives may be present in addition to the catalyst and the blowing agent. The catalyst, blowing agent, foam stabilizer, flame retardant and other auxiliary agents may be the same as those described above, and the preferred contents thereof are also the same as those described above.

[0045] The foam-forming step can be carried out by a known method, except that the polyol composition of the present invention is used as the polyol component. A specific example of the foam forming process is shown below. First, a mixture is prepared by mixing a polyol composition, a catalyst, a blowing agent, and, if necessary, other additives (foam stabilizers, flame retardants, and other auxiliaries). Next, the mixture is rapidly mixed with a polyisocyanate component using a polyurethane foaming machine or a mixer, and the resulting mixture (foaming liquid) is poured into a mold and cured for a predetermined time. The mixture is then demolded to obtain a polyurethane foam. The mold may be either an open mold (free foaming) or a closed mold (molded foaming). Curing may be performed at room temperature or under heat (e.g., 30 to 80°C). Spray foaming or continuous foaming may also be used. The one-shot method is preferred for the urethane reaction, since the viscosity of the raw solution obtained by mixing the components increases with the prepolymer method. This manufacturing method can be applied to both slab foam and molding by RIM (reaction injection molding), and can also be used to obtain polyurethane foam by the mechanical froth method.

[0046] In the foam-forming step, the isocyanate index (NCO INDEX) [(NCO group / active hydrogen atom-containing group) equivalent ratio × 100] is preferably 70 or more, more preferably 100 to 800, even more preferably 200 to 700, and particularly preferably 300 to 600, from the viewpoint of the mechanical properties and flame retardancy of the polyurethane foam.

[0047] The density (kg / m) of the molded polyurethane foam obtained by the production method of the present invention 3 In mold foaming, the core density with skin is preferably 80 or less, more preferably 15 to 78, particularly preferably 20 to 75, and most preferably 25 to 70. In free foaming, the core density is preferably 50 or less, more preferably 10 to 65, particularly preferably 15 to 63, and most preferably 20 to 61.

[0048] The compressive strength (N / cm) of the polyurethane foam obtained by the production method of the present invention 2 ) is preferably 12.0 or more, more preferably 14.0 or more, and even more preferably 15.0 or more.

[0049] The thermal conductivity (mW / m·K) of the polyurethane foam obtained by the production method of the present invention is preferably 27.0 or less, more preferably 24.0 or less, and even more preferably 23.0 or less.

[0050] The total calorific value (MJ / m) of the polyurethane foam obtained by the production method of the present invention2 From the viewpoint of flame retardancy, the saturation index is preferably 8.0 or less after a heating time of 5 minutes, more preferably 8.0 or less after a heating time of 5 minutes and 10 minutes, and particularly preferably 8.0 or less after a heating time of 5 minutes, 10 minutes, and 20 minutes. [Example]

[0051] The present invention will be further explained below with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, % means % by weight and parts means parts by weight.

[0052] <Production Example 1> An autoclave was charged with 100 parts of tetrabromobisphenol A, 1 part of triethylamine, and 50 parts of methyl ethyl ketone, and nitrogen substitution was performed (oxygen concentration in the gas phase: 450 ppm). 24 parts of 1,2-propylene oxide was introduced into the autoclave under conditions of a temperature of 100-120°C and a pressure of 0.05-0.35 MPa (gauge pressure), and added with stirring for 3 hours. Subsequently, triethylamine and methyl ethyl ketone were distilled off under reduced pressure under conditions of a temperature of 100-120°C and a pressure of -0.1 to -0.05 MPa (gauge pressure), yielding a bromine atom-containing polyol (A-1). The hydroxyl value of (A-1) was 172 mgKOH / g, and the bromine atom content was 48.4%.

[0053] <Production Example 2> A bromine atom-containing polyol (A-2) was obtained in the same manner as in Production Example 1, except that 24 parts of 1,2-propylene oxide was changed to 18 parts of ethylene oxide. The hydroxyl value of (A-2) was 178 mgKOH / g, and the bromine atom content was 50.1%.

[0054] <Production Example 3> An autoclave was charged with 100 parts of tetrabromophthalic anhydride, 0.2 parts of N-ethylmorpholine, 100 parts of methyl ethyl ketone, and 13.5 parts of ethylene glycol, and the mixture was purged with nitrogen (oxygen concentration in the gas phase: 450 ppm). The mixture was allowed to react for 5 hours with stirring at a temperature of 110-130°C and a pressure of 0.05-0.35 MPa (gauge pressure). Then, 10.5 parts of ethylene oxide was added to the autoclave with stirring for 3 hours at a temperature of 110-130°C and a pressure of 0.05-0.35 MPa (gauge pressure). The N-ethylmorpholine and methyl ethyl ketone were then distilled off under reduced pressure at a temperature of 100-120°C and a pressure of -0.1 to -0.05 MPa (gauge pressure), yielding a bromine-containing polyol (A-3). The hydroxyl value of (A-3) was 195 mgKOH / g, and the bromine atom content was 55.7%.

[0055] <Production Example 4> A bromine atom-containing polyol (A-4) was obtained in the same manner as in Production Example 1, except that 1 part of triethylamine was replaced with 0.3 parts of tetramethylammonium hydroxide and 24 parts of 1,2-propylene oxide was replaced with 40 parts of ethylene oxide. The hydroxyl value of (A-4) was 147 mgKOH / g, and the bromine atom content was 41.8%.

[0056] <Production Example 5> A bromine atom-containing polyol (A-5) was obtained in the same manner as in Production Example 1, except that 1 part of triethylamine was replaced with 0.3 parts of tetramethylammonium hydroxide and 24 parts of 1,2-propylene oxide was replaced with 81 parts of ethylene oxide. The hydroxyl value of (A-5) was 114 mg KOH / g, and the bromine atom content was 32.5%.

[0057] The raw materials for the polyurethane foams in Examples 1 to 10 and Comparative Examples 1 to 3 are as follows. (1) Polyol (P) containing no bromine atoms (P-1) Polyester polyol obtained from phthalic acid and ethylene glycol (hydroxyl value 250 mg KOH / g) (2) Bromine atom-containing polyol (A) (A-1) Bromine atom-containing polyol obtained in Production Example 1 (hydroxyl value 172 mg KOH / g, bromine atom content 48.4%) (A-2) Bromine atom-containing polyol obtained in Production Example 2 (hydroxyl value 178 mg KOH / g, bromine atom content 50.1%) (A-3) Bromine atom-containing polyol obtained in Production Example 3 (hydroxyl value 195 mg KOH / g, bromine atom content 55.7%) (A-4) Bromine atom-containing polyol obtained in Production Example 4 (hydroxyl value 147 mg KOH / g, bromine atom content 41.8%) (A-5) Bromine atom-containing polyol obtained in Production Example 5 (hydroxyl value 114 mg KOH / g, bromine atom content 32.5%) (3) Phosphate ester (B) (B-1) Tris(1-chloro-2-propyl)phosphate (manufactured by Daihachi Chemical Industry Co., Ltd.) (4) Catalyst (C) (C-1) "Dabco33LV" (Air Products Japan Co., Ltd.) (C-2) "Dabco K-15" (Air Products Japan Co., Ltd.) (C-3) "DabcoTMR7" (Air Products Japan Co., Ltd.) (5) Foam stabilizer (D) (D-1) "SH-193" (Dow Corning Toray Co., Ltd.) (6) Foaming agent (E) (E-1) Water (E-2)HFO-1233zdE (7) Polyisocyanate (F) (F-1) Crude MDI "MR-200" (manufactured by Tosoh Corporation), NCO%=31.5

[0058] <Examples 1 to 10 and Comparative Examples 1 to 3> The polyurethane foams of Examples 1 to 10 and Comparative Examples 1 to 3 were produced by the following methods: A polyol composition was prepared by blending predetermined amounts of bromine-free polyol (P), bromine-containing polyol (A), phosphate ester (B), catalyst (C), foam stabilizer (D), and blowing agent (E) in the amounts shown in Table 1. The polyol composition and the polyisocyanate (F) were each adjusted to a temperature of 20±5°C and rapidly mixed at 8000 rpm for 7 seconds using a Homodisper (manufactured by Primix Corporation).The mixed liquid was then quickly poured into a 300 x 300 x 50 mm mold adjusted to a temperature of 70°C, and the mold foaming was carried out to obtain a molded polyurethane foam.

[0059] Table 1 shows the measurement results of the molded article density, compressive strength, heat insulating property (thermal conductivity) and flammability of the molded articles obtained in each of the Examples and Comparative Examples.

[0060] <Method for measuring molded product density> After obtaining a molded product by the above method, the elastic modulus was calculated using the following formula. Molded product density (kg / m 3 ) = Weight of molded product (g) / Volume of molded product (cm 3 ) x 1000

[0061] <Method for measuring compressive strength> According to JIS K7220, a sample piece measuring 50 x 50 x 35 mm was cut out from the molded product. The sample piece was compressed by 10% of its thickness to measure the compressive stress. The compressive stress was then divided by the cross-sectional area to determine the compressive strength.

[0062] <Method for measuring thermal conductivity> According to JIS A1412-2, a sample piece measuring 200 × 200 × 50 mm was cut out from the molded product, and the thermal conductivity was then measured using a thermal conductivity measuring instrument "AUTO-Λ HC-074" (manufactured by Eiko Seiki Co., Ltd.).

[0063] <Method for measuring flammability (cone calorimeter)> A sample piece measuring 100 x 100 x 40 mm was cut from the center of the molded product. In accordance with ISO 5660, the total heat generation was measured using a "Cone Calorimeter C3" (manufactured by Toyo Seiki Seisakusho Co., Ltd.) after heating for 5, 10, and 20 minutes.

[0064] [Table 1]

[0065] As shown in Table 1, the polyurethane foams of Examples 1 to 10 all exhibit desirable properties in terms of molded article density, compressive strength, heat insulation (thermal conductivity), and flammability (flame retardancy). On the other hand, in Comparative Examples 1 and 2, the bromine atom content or the total amount of bromine atoms and phosphate ester in the polyol composition is insufficient, resulting in poor flame retardancy. In Comparative Example 3, the total amount of bromine atoms and phosphate ester in the polyol composition is excessive, resulting in poor compressive strength. [Industrial Applicability]

[0066] The flame-retardant polyurethane foam obtained using the polyol composition for producing a flame-retardant polyurethane foam of the present invention has high flame retardancy and excellent mechanical properties, and therefore can be advantageously used as an insulating material (particularly for sandwich panels, boards, siding, or spray applications) for building components such as ceilings, roofs, and walls of buildings such as apartment buildings and other collective housing, detached houses, and commercial buildings, as well as for various applications requiring flame retardancy and mechanical properties.

Claims

1. A polyol composition for producing a flame-retardant polyurethane foam, comprising a bromine atom-containing polyol and a phosphoric acid ester, the weight ratio of bromine atoms contained in the polyol composition is 1 to 35% by weight based on the weight of the polyol composition; the weight ratio of the phosphoric acid ester contained in the polyol composition is 1 to 35% by weight based on the weight of the polyol composition; A polyol composition for producing a flame-retardant polyurethane foam, wherein the total weight ratio of the weight ratio of bromine atoms and the weight ratio of phosphate ester contained in the polyol composition is 8 to 35% by weight based on the weight of the polyol composition.

2. 2. The polyol composition for producing a flame-retardant polyurethane foam according to claim 1, wherein the bromine atom-containing polyol is a compound in which at least one bromine atom is directly bonded to an aromatic ring.

3. A flame-retardant polyurethane foam obtained by reacting the polyol composition for producing a flame-retardant polyurethane foam according to claim 1 with a polyisocyanate, the weight ratio of bromine atoms contained in the polyurethane foam is 0.5 to 20% by weight based on the weight of the polyurethane foam; the weight ratio of the phosphate ester contained in the polyurethane foam is 0.5 to 20% by weight based on the weight of the polyurethane foam; A flame-retardant polyurethane foam, wherein the total weight ratio of the bromine atoms and the phosphate ester contained in said polyurethane foam is 4 to 20% by weight based on the weight of said polyurethane foam.

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