Mixed Systems

Abstract

To provide a mixing system that heightens miscibility of a polyol composition and a polyisocyanate composition in a stationary mixer and prevents hardening in the stationary blending system.SOLUTION: A mixing system comprises a first container filled with a polyol composition, a second container filled with an isocyanate composition, the polyol composition discharged from the first container, and a stationary mixer that mixes the polyol composition discharged from the first container and the isocyanate composition discharged from the second container, in which the polyol composition comprises polyol, a catalyst and a low boiling point compound having a boiling point lower than 0°C, the isocyanate composition contains the isocyanate compound and a low boiling point compound having a boiling point lower than 0°C, each inner pressure of the first container and the second container is in the range of 0.3 to 1.0 MPa at 35°C, and a length of a mixer part of the stationary mixer is 30 to 230 mm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a mixing system, and more particularly to a mixing system for mixing a polyol composition and a polyisocyanate composition to obtain a polyurethane foam. [Background technology]

[0002] Conventionally, polyurethane foams have been used as heat insulating materials in vehicles such as automobiles, railroad cars, and ships, buildings, etc. They are also used as repair agents for filling defects in vehicles, buildings, etc. Recently, there has been an increasing need to impart flame retardancy to these heat insulating materials and repair agents.

[0003] A widely used polyurethane foam is a two-component polyurethane in which a polyol liquid and an isocyanate liquid filled in separate containers are mixed to form the foam. Two-component polyurethanes are sometimes used in aerosol containers because each liquid can be discharged from a container with a relatively simple structure and mixed. When two-component polyurethanes are used in aerosol containers, one container is filled with a polyol compound and a low-boiling compound, and the other container is filled with a polyisocyanate compound and a low-boiling compound. The polyol liquid and polyisocyanate liquid are discharged from each container by the vapor pressure of the low-boiling compound, and then mixed to form a polyurethane foam.

[0004] The low boiling point compounds used in aerosol containers include hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), dimethyl ether (DME), liquefied petroleum gas (LPG), etc. Furthermore, because HFCs and HCFCs have a high global warming potential, there is a demand for alternative compounds to replace them. For example, Patent Document 1 describes a two-liquid aerosol composition for rigid polyurethane foam that contains a specific amount of a low-boiling point compound, and describes that by using liquefied petroleum gas (LPG), dimethyl ether (DME), etc. as the low-boiling point compound, there is no adverse effect on global warming.

[0005] When using the above-mentioned two-component polyurethane, small devices such as caulking guns and spray cans are used. These small devices are equipped with a static mixer, such as a static mixer, to promote mixing of the two components (see, for example, Patent Document 3). Furthermore, in polyurethane foam, a flame retardant may be used to impart flame retardant properties. In two-component polyurethane aerosols, the flame retardant is mixed, for example, in polyol, and as such a flame retardant, a liquid phosphoric acid ester compound such as tris(β-chloropropyl)phosphate is used as disclosed in Patent Document 2. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2006-169474 A [Patent Document 2] Japanese Patent Application Publication No. 11-49837 [Patent Document 3] WO2020 / 067139 issue Summary of the Invention [Problem to be solved by the invention]

[0007] In two-component polyurethane aerosols, the discharge flow rate must be increased when the polyol liquid and isocyanate liquid are discharged from their respective containers. If the discharge flow rate is insufficient, the polyol liquid and the isocyanate liquid will not mix well, the polyurethane foam will not be properly formed, and various properties such as flame retardancy will be reduced.

[0008] In recent years, due to the growing awareness of disaster prevention, polyurethane foams used as heat insulating materials are required to have high flame retardant performance, and the use of flame retardants with high flame retardant effects has been considered. However, most flame retardants with high flame retardant effects are solid, and when they are mixed with polyol, for example, they reduce the fluidity of the polyol. As a result, the discharge flow rate of the polyol liquid in the aerosol becomes insufficient, and problems occur such as the polyol liquid not being mixed sufficiently with the isocyanate liquid, and the flame retardancy cannot be sufficiently improved.

[0009] In order to thoroughly mix the polyol liquid and the isocyanate liquid and to improve flame retardancy, it is possible to lengthen the mixer portion of the static mixer. However, if the mixer portion is too long, the mixture may harden in the mixer, resulting in poor discharge. SUMMARY OF THE PRESENT EMBODIMENTS The present invention aims to provide a mixing system that enhances the mixing of a polyol composition and a polyisocyanate composition in a static mixer and prevents hardening in the static mixer. [Means for solving the problem]

[0010] As a result of intensive research aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by controlling the internal pressures of a container filled with a polyol composition and a container filled with an isocyanate composition within certain ranges and by setting the length of the mixer portion of a static mixer within a specific range, thereby completing the present invention. That is, the present invention is as follows.

[0011] [1] A mixing system comprising a first container filled with a polyol composition, a second container filled with an isocyanate composition, and a static mixer for mixing the polyol composition discharged from the first container and the isocyanate composition discharged from the second container, wherein the polyol composition comprises a polyol, a catalyst, and a low-boiling compound having a boiling point of less than 0°C, the isocyanate composition comprises an isocyanate compound and a low-boiling compound having a boiling point of less than 0°C, the internal pressures of the first container and the second container are each in the range of 0.3 to 1.0 MPa at 35°C, and the length of the mixer portion of the static mixer is 30 to 230 mm. [2] The mixing system according to [1] above, wherein the polyol composition contains a trimerization catalyst as the catalyst. [3] The mixing system according to [1] or [2] above, wherein the static mixer has an inlet divided into two holes. [4] The mixing system according to any one of the above [1] to [3], wherein the polyol composition further contains a filler. [5] The mixing system according to any one of the above [1] to [4], wherein the low-boiling point compound comprises a hydrofluoroolefin. [6] The mixing system according to any one of the above [1] to [5], wherein the low-boiling point compound includes at least one selected from air, carbon dioxide, and an inert gas. [7] The mixing system according to [6] above, wherein the inert gas is nitrogen. [8] The mixing system according to any one of the above [1] to [7], further comprising a discharge gun. Effect of the Invention

[0012] According to the present invention, a mixing system can be provided that enhances mixing of a polyol composition and an isocyanate composition in a static mixer and prevents hardening in the static mixer. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a conceptual diagram showing one embodiment of a mixing system of the present invention. [Diagram 2] FIG. 2 is a conceptual diagram showing another embodiment of the mixing system of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] [Mixed system] The outline of the mixing system of the present invention will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing the outline of the mixing system of the present invention. The mixing system 10 of the present invention includes a first container 11 filled with a polyol composition, a second container 12 filled with an isocyanate composition, and a static mixer (static mixer) 13 that mixes the polyol composition discharged from the first container and the isocyanate composition discharged from the second container. The internal pressure of the first container 11 and the second container 12 at 35°C is both in the range of 0.3 to 1.0 MPa. If the internal pressure is less than 0.3 MPa, the injection pressure is low and sufficient discharge and mixing cannot be performed. On the other hand, if the internal pressure exceeds 1.0 MPa, the container needs to be made highly pressure-resistant. From the above viewpoints, the internal pressure of the first container and the second container is both preferably in the range of 0.4 to 0.9 MPa, more preferably in the range of 0.5 to 0.8 MPa. The internal pressure of the first container and the second container may be the same or different.

[0015] The first and second containers 11, 12 are preferably aerosol spray cans, and inside the first container 11, a portion of the polyol composition may vaporize to form a gas phase, and inside the second container 12, a portion of the isocyanate composition may vaporize to form a gas phase. The polyol composition and the isocyanate composition discharged from the first and second containers 11, 12 are mixed while being foamed by a foaming agent or the like, and the isocyanate and the polyol react with each other to form a polyurethane foam (polyurethane composition).

[0016] The mixing system 10 also includes a static mixer (hereinafter, sometimes simply referred to as a "mixer") 13. The static mixer 13 is a mixer without a driving section, in which the fluids are mixed by passing through the inside of the tube. An example of the static mixer is one in which a mixer element 13B is arranged inside a tube 13A as shown in FIG. 1. The mixer element 13B may be one formed in a spiral shape or one formed with a plurality of baffle plates. In the mixing system 10 of the present invention, the outlets 11A, 12A of the first and second containers 11, 12 are connected to the mixer 13 via the supply lines 11B, 12B. The outlets 11A, 12A may be provided with valves such as stem valves. The polyol composition and the isocyanate composition discharged from the first and second containers 11, 12 are supplied to the mixer 13 via the supply lines 11B, 12B, respectively, and are mixed in the mixer 13. Here, it is preferable that the static mixer has an injection port divided into two holes, and the polyol composition and the isocyanate composition are preferably supplied to the mixer 13 separately from the injection ports of the two holes. This makes it possible to prevent the polyol composition and the isocyanate composition from coming into contact with each other before being injected into the mixer. The polyol composition and the isocyanate composition mixed in the mixer 13 are sprayed onto the surface to be applied by a sprayer or the like. The static mixer may also function as an injector. In that case, the mixture of the polyol composition and the isocyanate composition mixed inside the tube 13A may be injected from the tip 13C of the tube, as shown in FIG. 1.

[0017] In the present invention, as shown in Fig. 1, it is essential that the length (t) of the mixer portion of the static mixer 13 is in the range of 30 mm to 230 mm. If the length of the mixer portion is less than 30 mm, the polyol composition and the polyisocyanate composition are not mixed sufficiently, resulting in problems such as insufficient foaming and insufficient flame retardancy of the formed urethane foam. On the other hand, if the length of the mixer portion exceeds 230 mm, a reaction occurs between the polyol composition and the isocyanate composition in the mixer of the static mixer, causing partial hardening and resulting in poor discharge. From the above viewpoints, the length of the mixer portion of the static mixer is preferably in the range of 50 mm to 200 mm, and more preferably in the range of 60 mm to 190 mm. The mixer portion here refers to the portion of the tube 13A having the mixer element 13B.

[0018] FIG. 1 shows an embodiment in which the polyol composition and the polyisocyanate composition discharged from the first and second containers 11 and 12 are introduced into a mixer, but a discharge gun, a jig, or the like may be provided before the polyol composition and the polyisocyanate composition are introduced into the mixer. As an example of an embodiment equipped with a discharge gun before being introduced into the mixer, a mixing system 20 is shown in FIG. 2. The mixing system 20 includes a first container 11, a second container 12, supply lines 11B and 12B, a discharge gun 14, and a mixer 13. The first container 11 and the second container 12 are as described above, and contain a polyol composition and a polyisocyanate composition, respectively. The polyol composition and the polyisocyanate composition are sent from the first and second containers to the discharge gun 14 via the supply lines 11B and 12B, respectively. The discharge gun 14 includes a lever 14A and has an ON-OFF mechanism for sending. Specifically, when the lever 14A is pulled, the polyol composition and the polyisocyanate composition are sent to the mixer 13, and when the lever 14A is released, the sending to the mixer 13 is stopped. By using the mixing system 20 equipped with the dispensing gun 14, liquid can be delivered as needed, improving workability when forming a polyurethane foam.

[0019] [Polyol composition] The polyol composition of the present invention comprises a polyol, a catalyst, and a low-boiling compound having a boiling point of less than 0°C. (Polyol) The polyol composition of the present invention contains a polyol. Examples of the polyol used in the present invention include polylactone polyols, polycarbonate polyols, aromatic polyols, alicyclic polyols, aliphatic polyols, polyester polyols, polymer polyols, and polyether polyols.

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

[0021] Examples of aromatic polyols include bisphenol A, bisphenol F, phenol novolac, and cresol novolac. Examples of alicyclic polyols include cyclohexanediol, methylcyclohexanediol, isophoronediol, dicyclohexylmethanediol, and dimethyldicyclohexylmethanediol. Examples of the aliphatic polyol include ethylene glycol, propylene glycol, butanediol, pentanediol, and hexanediol.

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

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

[0024] Examples of polyether polyols include polymers obtained by ring-opening polymerization of at least one alkylene oxide (hereinafter also referred to as "AO") in the presence of at least one low molecular weight active hydrogen compound having two or more active hydrogens. Examples of AO include ethylene oxide (hereinafter also referred to as "EO"), 1,2-propylene oxide (hereinafter also referred to as "PO"), 1,3-propylene oxide, 1,2-butylene oxide, and 1,4-butylene oxide. Examples of AO include PO, EO, and 1,2-butylene oxide, and more preferably PO and EO. When two or more AOs are used (for example, PO and EO), the addition method may be block addition or random addition, or a combination of these. Examples of low molecular weight active hydrogen compounds having two or more active hydrogens include diols such as ethylene glycol, propylene glycol, butylene glycol, and 1,6-hexanediol; triols such as glycerin and trimethylolpropane; tetrahydric to octahydric alcohols such as pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, and dipentaerythritol; sucrose, glucose, mannose, fructose, methyl glucoside, and derivatives thereof; phloroglucinol, cresol, etc. Examples of suitable polyols include aromatic polyols such as pyrogallol, catechol, hydroquinone, bisphenol A, bisphenol F, bisphenol S, 1,3,6,8-tetrahydroxynaphthalene, and 1,4,5,8-tetrahydroxyanthracene; polyfunctional polyols such as castor oil polyol, (co)polymers of hydroxyalkyl (meth)acrylates, and polyvinyl alcohol; condensates of phenol and formaldehyde (novolaks), amines such as ethylenediamine, and butylenediamine.

[0025] The polyol used in the present invention is preferably a polyester polyol or a polyether polyol. Also, a polyol having two hydroxyl groups is preferred. Among them, a polyester polyol obtained by dehydration condensation of a polybasic acid having an aromatic ring such as isophthalic acid (m-phthalic acid) or terephthalic acid (p-phthalic acid) with a dihydric alcohol such as bisphenol A, ethylene glycol, or 1,2-propylene glycol is more preferred.

[0026] The hydroxyl value of the polyol is preferably 20 to 300 mgKOH / g, more preferably 30 to 250 mgKOH / g, and even more preferably 50 to 220 mgKOH / g. When the hydroxyl value of the polyol is equal to or less than the upper limit, the viscosity of the polyol composition is likely to decrease, which is preferable from the viewpoint of handling, etc. On the other hand, when the hydroxyl value of the polyol is equal to or more than the lower limit, the crosslink density of the polyurethane foam increases, thereby increasing the strength. The hydroxyl value of the polyol can be measured in accordance with JIS K 1557-1:2007.

[0027] The content of the polyol in the polyol composition of the present invention is preferably 10 to 80% by mass, more preferably 20 to 75% by mass, and even more preferably 25 to 70% by mass. When the content of the polyol is equal to or more than the lower limit, the polyol and the polyisocyanate are easily reacted. On the other hand, when the content of the polyol is equal to or less than the upper limit, the viscosity of the polyol composition does not become too high, and the handling property is improved.

[0028] (catalyst) The polyol composition of the present invention preferably contains at least a trimerization catalyst as a catalyst, and more preferably contains both a resinification catalyst and a trimerization catalyst. <Resinification catalyst> The resinification catalyst is a catalyst that promotes the reaction between a polyol compound and a polyisocyanate compound. Examples of the resinification catalyst include amine-based catalysts such as imidazole compounds and piperazine compounds, and metal-based catalysts. Examples of the imidazole compound 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. In addition, 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.

[0029] Examples of the metal catalyst 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, dioctyltin versatate, and organic acid bismuth salts such as bismuth trioctate, 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. Among the above, imidazole compounds are preferred.

[0030] The content of the resinification catalyst (the total when two or more kinds are contained) is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the polyol. When the content of the resinification catalyst is equal to or more than the lower limit, urethane bonds are easily formed and the reaction proceeds quickly. On the other hand, when the content is equal to or less than the upper limit, the reaction rate is easily controlled, and the mixture of the polyol composition and the isocyanate composition is hardened, so that clogging is less likely to occur in the static mixer. The polyol composition of the present invention may contain a substance containing impurities (e.g., diluent, etc.) other than the resinification catalyst component that functions as a resinification catalyst together with the resinification catalyst. In this case, the mass of only the resinification catalyst component excluding the impurities from the substance is the "content of the resinification catalyst".

[0031] <Trimerization catalyst> The polyol composition of the present invention preferably contains a trimerization catalyst. The trimerization catalyst is a catalyst that reacts the isocyanate group contained in the polyisocyanate to trimerize it and promote the formation of an isocyanurate ring. The inclusion of the trimerization catalyst improves the flame retardancy of the polyurethane foam. As the trimerization catalyst, nitrogen-containing aromatic compounds such as tris(dimethylaminomethyl)phenol, 2,4-bis(dimethylaminomethyl)phenol, and 2,4,6-tris(dialkylaminoalkyl)hexahydro-S-triazine, carboxylic acid alkali metal salts such as potassium acetate, potassium 2-ethylhexanoate, and potassium octylate, tertiary ammonium salts such as trimethylammonium salt, triethylammonium salt, and triphenylammonium salt, and quaternary ammonium salts such as tetramethylammonium salt, tetraethylammonium salt, tetraphenylammonium salt, triethylmonomethylammonium salt, and carboxylic acid quaternary ammonium salt can be used. These may be used alone or in combination of two or more.

[0032] Among the above, one or more carboxylates selected from the group consisting of alkali metal carboxylates and quaternary ammonium carboxylates are preferred. Among these, quaternary ammonium carboxylates are more preferred. These carboxylate trimerization catalysts proceed with the trimerization reaction immediately after initiation, and can reduce the amount of unreacted isocyanate. As a result, the flame retardancy of the polyurethane foam can be improved.

[0033] The content of the trimerization catalyst (the total when two or more kinds are contained) is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 2 to 10 parts by mass, based on 100 parts by mass of the polyol. When the content of the trimerization catalyst is equal to or more than the lower limit, the trimerization of the polyisocyanate is likely to occur, and the flame retardancy of the resulting polyurethane foam is improved. On the other hand, when the content of the trimerization catalyst is equal to or less than the upper limit, the reaction is easily controlled, and the mixture of the polyol composition and the isocyanate composition is hardened, and clogging does not occur in the static mixer. The polyol composition of the present invention may contain a substance containing impurities other than the trimerization catalyst component that functions as a trimerization catalyst together with the trimerization catalyst. In this case, the "content of the trimerization catalyst" refers to the mass of only the trimerization catalyst component obtained by excluding the impurities from the substance.

[0034] In addition, the total content of the trimerization catalyst and the resinification catalyst in the polyol composition of the present invention is not particularly limited, but is preferably 1 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. When the total content of both catalysts in the polyol composition of the present invention is equal to or more than these lower limits, the formation of urethane bonds and trimerization proceed appropriately, and the flame retardancy of the polyurethane foam is likely to be good. In addition, when the total content of both catalysts in the polyol composition of the present invention is equal to or less than these upper limits, the control of the urethane formation and trimerization reaction is easy, and the mixture of the polyol composition and the isocyanate composition is hardened, and clogging is unlikely to occur in a static mixer.

[0035] In the polyol composition of the present invention, the trimerization catalyst content / resinification catalyst content is preferably in the range of 1 / 10 to 1 / 1, more preferably 1 / 5 to 1 / 1, and even more preferably 1 / 3 to 1 / 1. When the trimerization catalyst content / resinification catalyst content is equal to or greater than the lower limit, the formation of urethane bonds and trimerization proceed appropriately, and the flame retardancy of the polyurethane foam is likely to be good. On the other hand, when the trimerization catalyst content / resinification catalyst content is equal to or less than the upper limit, the resinification catalyst and trimerization catalyst contents are reduced, and the mixture of the polyol composition and the isocyanate composition is cured, making it difficult for clogging to occur in a static mixer.

[0036] (low boiling point compound) The polyol composition and isocyanate composition of the present invention each contain a low-boiling compound having a boiling point of less than 0°C. The low-boiling compound can control the internal pressure of the first container and the second container at 35°C to 0.3 to 1.0 MPa. The higher the vapor pressure of the low-boiling compound, the higher the internal pressure in the container, and the higher the compatibility with the polyol or isocyanate, the lower the internal pressure in the container. Therefore, the internal pressure in the container can be controlled by the vapor pressure and content of the low-boiling compound, the compatibility of the low-boiling compound with the polyol, and the compatibility of the low-boiling compound with the isocyanate. In addition, the low boiling point compound in the polyol composition is vaporized when the polyol composition is discharged, and foams the polyol composition and the polyurethane composition described later. That is, it also functions as a foaming agent. In this specification, the boiling point means the boiling point at 1 atmospheric pressure. In addition, it means the boiling point of the low boiling point compound alone, and does not mean, for example, the boiling point of the azeotropic low boiling point compound with another compound. When the boiling point of the low-boiling compound exceeds 0° C., it becomes difficult to discharge the polyol composition, particularly the polyol composition containing a filler. From the viewpoint of making the polyol composition easier to discharge, the boiling point of the low-boiling compound is preferably −10° C. or lower, and more preferably −15° C. or lower.

[0037] The low boiling point compound used in the present invention is not particularly limited as long as it has a boiling point of less than 0° C., and examples thereof include hydrocarbons having 2 to 5 carbon atoms, dimethyl ether (DME, boiling point: −24° C.), hydrofluoroolefins (HFOs), hydrofluorocarbons (HFCs), air (compressed air), carbon dioxide (boiling point: −78.5° C.), inert gases, etc. Examples of inert gases include nitrogen (boiling point: −195.8° C.) and argon (boiling point: −185.8° C.). Among these, it is preferable to use an inert gas such as HFO, air, carbon dioxide, or nitrogen. By using HFO, air, carbon dioxide, or an inert gas, the low boiling point compound does not become a combustible product, and the flame retardancy of the polyurethane foam is easily improved. In addition, from the viewpoint of handling, it is more preferable that the low boiling point compound contains an HFO. The low boiling point compounds may be used alone or in combination. For example, it is preferable to use dimethyl ether in combination with LPG, and it is also preferable to further combine these with nitrogen. It is particularly preferable to use HFO such as 1,3,3,3-tetrafluoropropene (HFO-1234ze) in combination with air, carbon dioxide, or an inert gas, and it is even more preferable to use HFO such as HFO-1234ze in combination with nitrogen. By using HFO in combination with an inert gas, the decrease in discharge pressure due to use is suppressed, and the mixability is further improved.

[0038] Specific examples of the hydrocarbon having 2 to 5 carbon atoms include propane (boiling point: -42°C), isobutane (boiling point: -11.7°C), normal butane (boiling point: -0.5°C), etc. Among the hydrocarbon having 2 to 5 carbon atoms and dimethyl ether, preferred specific examples include dimethyl ether, and a mixed solvent of dimethyl ether with propane, isobutane, or normal butane, etc. Another suitable example is LPG (liquefied petroleum gas), which contains propane and butanes as its main components.

[0039] Examples of hydrofluoroolefins include fluoroalkenes having about 3 to 6 carbon atoms. The hydrofluoroolefins may be hydrochlorofluoroolefins having chlorine atoms, and therefore may be chlorofluoroalkenes having about 3 to 6 carbon atoms. Preferred hydrofluoroolefins are fluoroalkenes having 3 or 4 carbon atoms, and more preferred hydrofluoroolefins are fluoroalkenes having 3 carbon atoms. 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, examples thereof include trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E), boiling point: -19°C), cis-1,2,3,3,3-pentafluoropropene (HFO-1225ye(Z), boiling point: -19°C), 3,3,3-trifluoropropene (HFO-1243zf, boiling point: -18°C), 2,3,3,3-tetrafluoropropene (HFO-1234yf, boiling point: -29°C), 1,1,3,3,3-pentafluoropropene (HFO-1225zc, boiling point: -21°C), trans-1,2,3,3,3-pentafluoropropene (HFO-1225ye(E), boiling point: -10°C), and the like. These hydrofluoroolefins may be used alone or in combination of two or more kinds.

[0040] Specific examples of hydrofluorocarbons (HFCs) include trifluoromethane (HFC-23, boiling point: about -82°C), difluoromethane (HFC-32, boiling point: about -51.7°C), and 1,1,1,2-tetrafluoroethane (HFC-134a, boiling point: about -26.2°C). These hydrofluorocarbons may be used alone or in combination of two or more. The above HFOs and HFCs may also be used in combination.

[0041] The content of the low boiling point compound is preferably 1 to 60 parts by mass, more preferably 5 to 50 parts by mass, even more preferably 7 to 45 parts by mass, and even more preferably 10 to 40 parts by mass, relative to 100 parts by mass of the polyol. When the content of the blowing agent is equal to or more than the lower limit, foaming is promoted, 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.

[0042] The polyol composition of the present invention may contain water from the viewpoint of adjusting the isocyanate index and from the viewpoint of ease of handling.

[0043] (phosphate ester) The polyol composition of the present invention may contain a phosphoric acid ester. When the polyol composition of the present invention contains a phosphoric acid ester, the flame retardancy of the polyurethane foam can be improved. The phosphoric acid ester is preferably a liquid flame retardant that is liquid at room temperature (23° C.) and normal pressure (1 atm.) By including a phosphoric acid ester, which is a liquid flame retardant, the flame retardancy of the polyurethane composition of the present invention can be improved without substantially decreasing the discharge flow rate and mixability of the polyol composition of the present invention.

[0044] As the phosphoric acid ester, it is preferable to use monophosphoric acid ester, condensed phosphoric acid ester, etc. As the monophosphoric acid ester, for example, trialkyl phosphate such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri(2-ethylhexyl)phosphate, halogen-containing phosphoric acid ester such as tris(β-chloropropyl)phosphate, trialkoxy phosphate such as tributoxyethyl phosphate, aromatic ring-containing phosphoric acid ester such as tricresyl phosphate, trixylenyl phosphate, tris(isopropylphenyl)phosphate, cresyl diphenyl phosphate, diphenyl(2-ethylhexyl)phosphate, monoisodecyl phosphate, diisodecyl phosphate, and other acidic phosphoric acid esters are listed. Among them, halogen-containing phosphoric acid ester, particularly tris(β-chloropropyl)phosphate, etc. are preferable.

[0045] 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.

[0046] Among these, from the viewpoint of reducing the viscosity of the mixture of the polyol composition and the isocyanate composition of the present invention to facilitate the production of polyurethane foam, and from the viewpoint of improving the flame retardancy of the polyurethane foam, monophosphate esters are preferred, and tris(β-chloropropyl) phosphate is more preferred.

[0047] When the polyol liquid contains a phosphoric acid ester, the content of the phosphoric acid ester in the polyol liquid is preferably 5 to 90 parts by mass, more preferably 15 to 80 parts by mass, and even more preferably 25 to 70 parts by mass, based on 100 parts by mass of the polyol. By making the content of the phosphoric acid ester equal to or greater than these lower limits, the effect of containing the phosphoric acid ester is easily exhibited. In addition, by making the content equal to or less than the upper limits, the foaming of the polyurethane foam is not inhibited by the phosphoric acid ester.

[0048] (Filler) The polyol composition of the present invention preferably contains a filler. By including a filler, various properties such as flame retardancy of the polyurethane foam can be easily improved. The filler preferably contains a flame retardant. By using a flame retardant as a filler, high flame retardancy can be imparted to the polyurethane foam. The flame retardant used as the filler is a solid flame retardant. In the present invention, by using a solid flame retardant, the flame retardancy can be more effectively improved. The solid flame retardant is a flame retardant that becomes solid at room temperature (23°C) and normal pressure (1 atm). The solid flame retardant used in the present invention is preferably at least one selected from the group consisting of phosphate-containing flame retardants, red phosphorus-based flame retardants, bromine-containing flame retardants, boron-containing flame retardants, antimony-containing flame retardants, metal hydroxides, and needle-shaped fillers.

[0049] Examples of the phosphate-containing flame retardant include phosphates consisting of salts of various phosphoric acids and at least one metal or compound selected from metals in 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-triidine, 2,4,6-trimethylaniline, anisidine, 3-(trifluoromethyl)aniline, etc. Examples of the heterocyclic compound containing nitrogen in the ring include pyridine, triazine, melamine, etc.

[0050] Specific examples of phosphate-containing flame retardants include monophosphates such as aluminum triphosphate, pyrophosphates, polyphosphates, etc. Here, the polyphosphates are not particularly limited, but include, for example, 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. In the present invention, aluminum tertiary phosphate is preferred.

[0051] The red phosphorus-based flame retardant may be composed of red phosphorus alone, may be red phosphorus coated with a resin, a metal hydroxide, a metal oxide, or the like, or may be a mixture of red phosphorus and a resin, a metal hydroxide, a metal oxide, or the like. The resin that coats the red phosphorus or is mixed with the red phosphorus is not particularly limited, but examples thereof include thermosetting resins such as phenol resins, epoxy resins, unsaturated polyester resins, melamine resins, urea resins, aniline resins, and silicone resins. 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.

[0052] The bromine-containing flame retardant is not particularly limited as long as it contains bromine in its molecular structure and is a solid at room temperature and pressure. Examples of the bromine-containing flame retardant 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, ethylene bis(pentabromophenyl), ethylene bis(tetrabromophthalimide), and tetrabromobisphenol A.

[0053] In addition, the brominated aromatic ring-containing aromatic compound may be a bromine compound polymer.Specific examples include brominated polycarbonates such as polycarbonate oligomers produced from brominated bisphenol A as a raw material, copolymers of this polycarbonate oligomer and bisphenol A, and diepoxy compounds produced by the reaction of brominated bisphenol A and epichlorohydrin.Furthermore, examples include brominated epoxy compounds such as monoepoxy compounds obtained by the reaction of brominated phenols and epichlorohydrin, poly(brominated benzyl acrylate), brominated phenol condensates of brominated polyphenylene ether, brominated bisphenol A, and cyanuric chloride, brominated (polystyrene), poly(brominated styrene), brominated polystyrene such as crosslinked brominated polystyrene, crosslinked or non-crosslinked brominated poly(-methylstyrene), and the like. In addition, compounds other than brominated aromatic ring-containing aromatic compounds such as hexabromocyclododecane may 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 hexabromobenzene are preferred.

[0054] The boron-containing flame retardant used in the present invention includes borax, boron oxide, boric acid, borate, 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 kinds. The boron-containing flame retardant used in the present invention is preferably a borate, more preferably zinc borate.

[0055] 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 include sodium pyroantimonate and potassium pyroantimonate. The antimony-containing flame retardants 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.

[0056] Examples of the 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, and tin hydroxide. The metal hydroxides may be used alone or in combination of two or more. The preferred metal hydroxide used in the present invention is aluminum hydroxide.

[0057] Examples of needle-like fillers include potassium titanate whiskers, aluminum borate whiskers, magnesium-containing whiskers, silicon-containing whiskers, wollastonite, sepiolite, zonolite, elestadite, boehmite, rod-shaped hydroxyapatite, glass fibers, carbon fibers, graphite fibers, metal fibers, slag fibers, gypsum fibers, silica fibers, alumina fibers, silica alumina fibers, zirconia fibers, boron nitride fibers, boron fibers, and stainless steel fibers. These needle-like fillers can be used alone or in combination of two or more.

[0058] The aspect ratio (length / diameter) of the needle-like filler used in the present invention is preferably in the range of 5 to 50, and more preferably in the range of 10 to 40. The aspect ratio can be determined by observing the needle-like filler with a scanning electron microscope and measuring its length and width.

[0059] (Anti-settling agent) The polyol composition of the present invention may contain an anti-settling agent as a filler. By using the anti-settling agent, precipitation of the solid flame retardant dispersed in the polyol composition can be prevented. In addition, by using the anti-settling agent, the solid flame retardant can be easily dispersed uniformly. The anti-settling agent is generally solid at room temperature and normal pressure, and usually becomes a solid content (insoluble content) in the polyol composition.

[0060] The anti-settling agent is not particularly limited, but it is preferable to use one or more selected from, for example, carbon black, powdered silica, organic clay, etc., and among these, powdered silica is more preferable. The carbon black used in the anti-settling agent may be produced by a furnace method, a channel method, a thermal method, etc. The carbon black may be appropriately selected from commercially available products. As the powdered silica, fumed silica, colloidal silica, silica gel, etc. can be used. Of these, fumed silica is preferable. As the fumed silica, Aerosil (registered trademark) from Nippon Aerosil Co., Ltd. can be used.

[0061] The content of the anti-settling agent is not particularly limited, but is, for example, 0.5 to 20 parts by mass, preferably 1 to 10 parts by mass, and more preferably 1.5 to 5 parts by mass, relative to 100 parts by mass of the polyol. By setting the content of the anti-settling agent within the above range, it is possible to prevent the settling of the solid flame retardant and improve its dispersibility without increasing the solid content more than necessary.

[0062] As the filler, inorganic fillers other than the solid flame retardant and anti-settling agent may be used. Examples of inorganic fillers include silica, diatomaceous earth, alumina, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dawsonite, hydrotalcite, calcium sulfate, barium sulfate, calcium silicate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass beads, silica balloons, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon balloons, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, various magnetic powders, fly ash, silica alumina fiber, and zirconia fiber. These inorganic fillers may be used alone or in combination of two or more.

[0063] When the polyol composition of the present invention contains a filler, the content thereof is preferably 10 to 150 parts by mass, more preferably 15 to 130 parts by mass, even more preferably 30 to 120 parts by mass, and even more preferably 40 to 100 parts by mass, relative to 100 parts by mass of the polyol. When the content of the filler is equal to or more than the lower limit, the polyurethane foam produced using the polyol composition can be sufficiently imparted with performance such as flame retardancy. On the other hand, when the content of the filler is equal to or less than the upper limit, the flowability of the polyol is not reduced, the discharge flow rate of the polyol composition is sufficient, and the polyol composition can be sufficiently mixed with the isocyanate composition, thereby making it possible to improve various performances such as flame retardancy.

[0064] (Foam stabilizer) The polyol composition of the present invention may contain a foam stabilizer for the purpose of facilitating foaming of the mixture of the polyol composition and the isocyanate composition. Examples of the foam stabilizer include polyoxyalkylene-based foam stabilizers such as polyoxyalkylene alkyl ethers, and surfactants such as silicone foam stabilizers such as organopolysiloxanes. These foam stabilizers may be used alone or in combination of two or more.

[0065] The content of the foam stabilizer in the polyol composition of the present invention is preferably 0.1 to 10 parts by mass, more preferably 1 to 8 parts by mass, and even more preferably 1 to 5 parts by mass, based on 100 parts by mass of the polyol. When the content of the foam stabilizer is equal to or more than the lower limit, the mixture of the polyol composition and the isocyanate composition is easily foamed, so that a homogeneous polyurethane foam can be obtained. When the content of the foam stabilizer is equal to or less than the upper limit, the balance between the production cost and the obtained effect is optimal.

[0066] (Other ingredients) Furthermore, the polyol composition of the present invention may contain, as necessary, one or more selected from phenol-based, amine-based, sulfur-based and other antioxidants, heat stabilizers, metal inhibitors, antistatic agents, stabilizers, crosslinking agents, lubricants, softeners, pigments, and the like, within the scope of the object of the present invention.

[0067] (Method of producing polyol composition) The method for producing the polyol composition of the present invention is not particularly limited, and the components other than the low boiling point compound are stirred with a known stirring device, and then a blowing agent is added to the obtained raw material, which is then stirred and filled into a container such as an empty aerosol can. The aerosol can is sealed with a stem valve, and the low boiling point compound is injected through the stem valve to produce a polyol composition filled in the container.

[0068] [Isocyanate composition] The polyisocyanate used in the isocyanate composition may be any known polyisocyanate compound used in the formation of polyurethane foam, such as aromatic polyisocyanate, alicyclic polyisocyanate, and 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.

[0069] Examples of the alicyclic polyisocyanate include cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and dimethyldicyclohexylmethane diisocyanate.

[0070] Examples of the aliphatic polyisocyanate include methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate.

[0071] Among these, from the viewpoints of ease of use and availability, aromatic polyisocyanates are preferred, and polymethylene polyphenyl polyisocyanates are more preferred. The polyisocyanate compounds may be used alone or in combination of two or more.

[0072] The isocyanate composition usually further contains a low-boiling compound. As the low-boiling compound, the above-mentioned low-boiling compounds having a boiling point of 0° C. or less can be used without any particular limitation. The low-boiling compound used in the polyisocyanate composition may be the same as or different from the low-boiling compound used in the polyol composition. The proportion of the low boiling point compound contained in the polyisocyanate composition is preferably 1 to 30 mass%, more preferably 2 to 25 mass%, and even more preferably 3 to 20 mass%. When the proportion of the low boiling point compound is equal to or higher than the lower limit, sufficient ejection force can be obtained, and when the proportion is equal to or lower than the upper limit, the foaming density does not become too low, and appropriate physical properties can be obtained. Furthermore, the isocyanate composition may appropriately contain known additives contained in polyisocyanate compounds before being mixed with the polyol composition.

[0073] The polyol composition and the isocyanate composition preferably have substantially the same volume. Specifically, the volume ratio of the isocyanate composition to the polyol composition is preferably 0.8 to 1.2, more preferably 0.9 to 1.1, and further preferably 0.95 to 1.05.

[0074] [Polyurethane composition] The polyurethane composition according to the present invention is formed from a mixture in which the polyol composition according to the present invention and the isocyanate composition are mixed in a static mixer.

[0075] (Isocyanate Index) The isocyanate index of the polyurethane composition of the present invention is not particularly limited, but is preferably 200 or more. If the amount of the polyisocyanate compound relative to the polyol compound is excessive, a large amount of the trimerization catalyst is required, but in the present invention, a specific amount of the resinification catalyst is used together with the trimerization catalyst, so that the amount of the trimerization catalyst used can be reduced. If the isocyanate index is equal to or greater than the lower limit, the amount of the polyisocyanate compound relative to the polyol compound becomes excessive, which makes it easier to generate isocyanurate bonds due to the trimerization of the polyisocyanate compound, and as a result, the flame retardancy of the polyurethane foam is improved. In addition, it is possible to impart non-flammability. Furthermore, if the isocyanate index is equal to or greater than the above lower limit, it is easy to produce a polyurethane foam having isocyanurate bonds, i.e., a polyurethane foam having both flame retardancy and heat insulation at a high level. From these viewpoints, the isocyanate index is more preferably 250 or more, even more preferably 300 or more, and particularly preferably 350 or more. The isocyanate index is preferably not more than 1000, more preferably not more than 800, and particularly preferably not more than 500. When the isocyanate index is not more than the upper limit, the resulting polyurethane foam has 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 compound ÷ (number of equivalents of polyol compound + number of equivalents of water) × 100 Here, each equivalent number can be calculated as follows: Equivalent number of polyisocyanate compound = Amount of polyisocyanate compound used (g) × NCO content (mass%) / Molecular weight of NCO (mol) × 100 Equivalent number of polyol compound = OHV × amount of polyol compound used (g) ÷ molecular weight of KOH (mmol) OHV is the hydroxyl value (mgKOH / g) of the polyol compound. Equivalents of water = amount of water used (g) / molecular weight of water (mol) × number of OH groups in water In the above formulas, the molecular weight of NCO is 42 (mol), the molecular weight of KOH is 56100 (mmol), the molecular weight of water is 18 (mol), and the number of OH groups in water is 2.

[0077] (Method of producing polyurethane composition) The method for producing the polyurethane composition of the present invention is not particularly limited, but the polyurethane composition is formed by mixing the polyol composition of the present invention and the isocyanate composition in a static mixer and discharging the mixture from a dispenser such as a caulking gun or a sprayer. The method for forming the polyurethane composition of the present invention using a caulking gun is, for example, carried out as follows: The polyol composition of the present invention and the isocyanate composition are discharged from cartridge containers each filled with the two compositions, and mixed in a static mixer such as a static mixer, and the mixture is sprayed from a caulking gun to cause foaming. The method for forming the polyurethane composition of the present invention by spraying is, for example, carried out as follows: The polyol composition of the present invention and the isocyanate composition are discharged from pressure-resistant spray containers each filled with the composition, and the two compositions are mixed in a static mixer such as a static mixer, and the mixture is sprayed from the tip of the static mixer to cause foaming.

[0078] (Uses of polyurethane compositions) In the present invention, the polyurethane composition can be used in various applications, but is preferably used as a heat insulating material. The polyurethane composition is preferably used to form a polyurethane foam. By forming a polyurethane foam, a large number of bubbles are formed, which provides a heat insulating effect. The polyurethane composition is more preferably used as a heat insulating material for vehicles or buildings. Examples of vehicles include railroad cars, automobiles, ships, and aircraft. The polyurethane composition of the present invention has high flame retardancy by using the above-mentioned polyol composition. Therefore, from the viewpoint of disaster prevention and safety, it can be suitably used for applications in vehicles or buildings. The mixing system of the present invention is also suitable for use as a small device and is well suited for repair applications. EXAMPLES

[0079] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these.

[0080] The components used in the examples and comparative examples are shown below, and the content (parts by mass) of each component is shown in Table 1.

[0081] 1) Polyol compound: phthalic acid polyester polyol (manufactured by Kawasaki Chemical Industries, Ltd., product name: Maximol RLK-087, hydroxyl value = 200 mg KOH / g) 2) Trimerization catalyst: quaternary ammonium carboxylate (concentration 45 to 55% by mass, diluted with ethylene glycol) (manufactured by Evonik Japan, product name: DABCO TMR-7) 3) Resinification catalyst: Imidazole derivative (concentration 65-75% by mass, Kao Corporation, product name: KL No. 390) 4) Liquid flame retardant (phosphate ester): Tris(β-chloropropyl)phosphate (manufactured by Daihachi Chemical Industry Co., Ltd., product name: TMCPP) 5) Solid flame retardants (fillers) Red phosphorus: manufactured by Rinkagaku Kogyo Co., Ltd. Product name: Nova Excel 140 Zinc borate: Hayakawa Shoji Co., Ltd., product name: FIREBREAK ZB Brominated flame retardant: Ethylenebis(pentabromophenyl), manufactured by Albemarle Corporation, product name: SAYTEX (registered trademark) 8010 6) Anti-settling agent: Fumed silica (manufactured by Nippon Aerosil Co., Ltd., product name: Aerosil R976S) 7)Low boiling point compounds DME / LPG: A mixture of dimethyl ether (DME) and liquefied petroleum gas (LPG), mixing ratio: DME:LPG = 6:4 (by mass) (manufactured by Iwatani Gas, product name: LPG-D, boiling point: below 0°C) Boiling point of DME: -24℃ Boiling point of propane, which is a component of LPG: -42℃ Boiling point of isobutane, which is a component of LPG: -11.7℃ Boiling point of normal butane, which is a component of LPG: -0.5℃ HFO-1234ze (1,3,3,3-tetrafluoropropene): manufactured by Honeywell, product name: Solstice (registered trademark) GBA, boiling point: -19°C Nitrogen, boiling point: -195.8℃ 8) Polyisocyanate: Diphenylmethane-4,4'-diisocyanate (MDI), manufactured by Bayer, product name: DESMODUR (registered trademark) 44V20L

[0082] Examples 1 to 10 and Comparative Examples 1 to 3 The components other than the low boiling point compound were mixed in the amounts shown in Table 1, and the mixture was poured into an empty aerosol can. The aerosol can was then sealed with a stem valve. The low boiling point compound was poured through the stem valve to the mass shown in Table 1, to form a first container. Next, polyisocyanate was poured into another empty aerosol can so that the mass was as shown in Table 1, and the aerosol can was sealed with the stem valve. A low-boiling compound was poured into the stem valve so that the mass was as shown in Table 1, to form a second container.

[0083] The re-dischargeability of the mixture and the flame retardancy of the polyurethane foam were evaluated as follows. The results are shown in Table 1.

[0084] (1) Re-dischargeability of the mixture (clogging) The stem valves of the first and second containers were pressed simultaneously for 5 seconds to discharge the polyol composition and the polyisocyanate composition, which were then injected into a static mixer (manufactured by Ritter, product name: ACF Helix 8-18) using a tube. These compositions were mixed in the mixer and discharged to form a polyurethane foam. After 5 seconds of ejection, the composition was left for 30 seconds, and the stem valve was pressed again for 5 seconds in the same manner as above to eject each composition, and then the composition was left for 30 seconds. This cycle of 5 seconds of ejection and 30 seconds of leaving was repeated, and the re-ejectability was evaluated based on how many times ejection was possible. The evaluation criteria were as follows: ○: Discharge was possible three or more times. ×: Only two ejections were possible.

[0085] (2) Flame retardancy of polyurethane foam The stem valves of the first and second containers were pressed simultaneously to discharge the polyol composition and the polyisocyanate composition, which were then injected into the static mixer (mentioned above) using a tube. These compositions were mixed in the mixer and discharged to form a polyurethane foam on a gypsum board with a thickness of 12.5 mm. After the polyurethane foam was cured, the gypsum board and the polyurethane foam were cut into a size of 10 cm x 10 cm and a thickness of 30 mm. The obtained sample was subjected to a test for a radiant heat intensity of 50 kW / m according to the test method of ISO-5660. 2 The total calorific value was measured using a cone calorimeter when the sample was heated at 40°C for 5 minutes. The evaluation criteria are as follows: ◎: Total heat generated over 5 minutes is 8MJ or less 〇: Total heat output for 5 minutes is over 8MJ and is 10MJ or less ×: Total heat generated over 5 minutes exceeds 10MJ

[0086] (3) How to measure internal pressure In each of the Examples and Comparative Examples, each container filled with the polyol composition and the polyisocyanate composition was immersed in a thermostatic water bath at 35°C for 90 minutes, and then a Bourdon tube pressure gauge was connected to the stem valve of the container to measure the internal pressure of each container.

[0087] [Table 1] *The values ​​for the polyol composition and isocyanate composition are in parts by mass, and the units for the internal pressure are in MPa.

[0088] In the examples, both the re-ejection evaluation (clogging) and the flame retardancy evaluation were good. On the other hand, in Comparative Example 1, in which the internal pressure of the first container filled with the polyol composition and the second container filled with the isocyanate composition was less than 0.3 MPa, clogging occurred. In Comparative Example 2, in which a static mixer with a mixer part length of less than 30 mm was used, it was found that the flame retardancy of the produced polyurethane foam was insufficient. In Comparative Example 3, in which a static mixer with a mixer part length of more than 230 mm was used, curing proceeded in the mixer, causing clogging. [Explanation of symbols]

[0089] 10 Mixed Systems 11 First Container 12 Second Container 11A, 12A outlet 11B,12B supply line 13 Static mixer 13A Body 13B Mixer Element 13C Tip 14 Discharge gun 14A Lever 20 Mixed Systems

Claims

1. A mixing system including a first container filled with a polyol composition, a second container filled with an isocyanate composition, and a static mixer that mixes the polyol composition discharged from the first container and the isocyanate composition discharged from the second container, The polyol composition comprises a polyol, a catalyst, a flame retardant, and a low-boiling compound having a boiling point of less than 0° C. The isocyanate composition contains an isocyanate compound and a low-boiling point compound having a boiling point of less than 0°C, The low-boiling compounds each having a boiling point of less than 0° C. each contain a hydrofluoroolefin, The internal pressure of each of the first and second containers is in the range of 0.3 to 1.0 MPa at 35° C., and the length of the mixer portion of the static mixer is 30 to 230 mm.

2. 10. The mixing system of claim 1, wherein said polyol composition comprises as said catalyst a trimerization catalyst.

3. 3. The mixing system according to claim 1, wherein the static mixer has an inlet divided into two holes.

4. The mixing system of any one of claims 1 to 3, wherein the polyol composition further comprises a filler.

5. A mixing system described in any one of claims 1 to 4, wherein the low-boiling point compound contained in the polyol composition and / or the isocyanate composition further contains nitrogen.

6. The mixing system according to any one of claims 1 to 5, further comprising a dispensing gun.

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