Composition for forming polyurethane foam, polyurethane foam and heat insulating material

Abstract

To provide a composition for forming a polyurethane foam having excellent surface quality, particularly smoothness, of a formed article.SOLUTION: A composition for forming a polyurethane foam comprises a hydrofluoroolefin as a foaming agent and the composition comprises 0.2 to 6 pts.mass of at least one compound represented by Formula 1 relative to 100 pts.mass of the composition: RO(CH2CH2O)nR (Formula 1) where R is a C1 to C3 linear or branched alkyl, and n is an integer of 1 or more.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a composition for forming a polyurethane foam, a polyurethane foam formed from the composition, and a heat insulating material comprising the foam, and more specifically, to a composition for forming a polyurethane foam having excellent surface quality, particularly smoothness, of a molded article. [Background technology]

[0002] Among resin foams, polyurethane foams, particularly rigid polyurethane foams, have excellent heat insulating properties and are therefore widely used as foam-based heat insulating materials. Polyurethane foams are usually produced by mixing polyol and polyisocyanate together with catalysts, blowing agents, foam stabilizers, etc., which are appropriately blended as necessary, and foaming the mixture.

[0003] Conventionally, hydrofluorocarbon (HFC) blowing agents such as HFC-134a, HFC-245fa, and HFC-365mfc have been used as blowing agents for rigid polyurethane foams. However, although these hydrofluorocarbon blowing agents are recognized as alternative fluorocarbons that cause little or no ozone layer depletion, they have a high global warming potential because they are chemically stable, and there are concerns that the use of HFC blowing agents will lead to global warming, so a gradual reduction in their use is being promoted under the Montreal Protocol (Kigali Amendment).

[0004] In recent years, halogenated hydroolefin blowing agents called hydrofluoroolefins (HFOs), which are chemically unstable and therefore have a lower global warming potential, have begun to be used in place of these HFC blowing agents.

[0005] JP 2016-74886 A (Patent Document 1) describes an invention related to a polyol composition for rigid polyurethane foams that contains 1-chloro-3,3,3-trifluoropropene (HFO-1233zd) as an essential blowing agent component. The invention described in Patent Document 1 aims to provide a polyol composition for rigid polyurethane foams that has good stock solution storage stability even when HFO-1233zd is used as the blowing agent component and can suppress deterioration of the physical properties of the rigid polyurethane foam, and is characterized by containing ethyl diglycol acetate as a compatibilizer for HFO-1233zd.

[0006] In addition, although not characterized by the use of HFO as a blowing agent, JP2019-533754A (Patent Document 2) aims to provide a polyol composition that is stable under all conditions, specifically a polyol composition that is stable for at least 24 hours, and in some cases for more than 6 months, in order to solve the problem that polyol compositions used as raw materials for polyurethane foams tend to phase separate over time. The polyol composition described in Patent Document 2 is a polyol composition comprising two or more polyols and a polyol having the formula: RO(CH2CH2O) n H, where R is a C1-C31 linear or branched alkyl, and n is an integer of 1 or greater, and is characterized in that it contains an ethoxylated alcohol having a hydrophilic-lipophilic balance (HLB) value of about 3.7 or greater. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2016-74886 A [Patent Document 2] Special Publication No. 2019-533754 Summary of the Invention [Problem to be solved by the invention]

[0008] The present inventors have investigated the use of hydrofluoroolefins (HFOs) as blowing agents for polyurethane foams and have found that when polyurethane foam is molded integrally with a facing material, the smoothness of the facing material of the resulting molded product is inferior to that in the case of using other blowing agents, resulting in a problem of reduced surface quality.

[0009] It is therefore an object of the present invention to provide a composition for forming a polyurethane foam having excellent surface quality, particularly smoothness, of a molded product by solving the above-mentioned problems of the prior art. Another object of the present invention is to provide a polyurethane foam formed from the composition and a heat insulating material comprising the foam. [Means for solving the problem]

[0010] The inventors have confirmed that the use of hydrofluoroolefin (HFO) as a blowing agent causes shrinkage in polyurethane foam, and believe that this shrinkage tends to reduce the smoothness of the facing material.

[0011] The process of forming polyurethane foam generally consists of (1) foaming through the reaction of polyisocyanate with water, and (2) the formation of urethane bonds through the reaction of polyisocyanate with polyol, and the reactions begin in this order. However, when HFO is used as the blowing agent, it is thought that the HFO volatilizes before bubbles are generated through the foaming process (1) above, causing the polyurethane foam to shrink.

[0012] Therefore, the present inventors have conducted extensive research to achieve the above object, and have discovered that in a polyurethane foam-forming composition containing HFO as a blowing agent, a compound represented by the formula 1: RO(CHCHO) n The inventors have found that a polyurethane foam having excellent surface smoothness can be formed by using a compound represented by the formula R (wherein R is a C1-C3 linear or branched alkyl, and n is an integer of 1 or more), and have thus completed the present invention.

[0013] That is, the composition of the present invention is a composition for forming a polyurethane foam, which contains a hydrofluoroolefin as a blowing agent and 0.2 to 6 parts by mass of at least one compound represented by the following formula 1 per 100 parts by mass of the composition. RO(CH2CH2O) n R (Formula 1) [In the formula, R is a C1 to C3 linear or branched alkyl, and n is an integer of 1 or more.]

[0014] In a preferred embodiment of the composition of the present invention, the polyether polyol is contained in an amount of 25 parts by mass or more based on 100 parts by mass of the composition.

[0015] In another preferred embodiment of the composition of the present invention, the isocyanate index is 150 or less.

[0016] In another preferred embodiment of the composition of the present invention, the viscosity of the polyol contained in the composition is 500 mPas (25° C.) or more.

[0017] The polyurethane foam of the present invention is obtained by foaming the above-mentioned composition.

[0018] A preferred embodiment of the polyurethane foam of the present invention is a polyurethane foam with a facing material.

[0019] The heat insulating material of the present invention is made of the above polyurethane foam. Effect of the Invention

[0020] The composition of the present invention can provide a composition for forming a polyurethane foam having excellent surface quality, particularly smoothness, of a molded product. The polyurethane foam of the present invention can provide a polyurethane foam formed from the composition, and the insulating material of the present invention can provide an insulating material made of the polyurethane foam. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention will be described in detail below.

[0022] One aspect of the present invention is a composition for forming a polyurethane foam. The composition contains a polyol, a polyisocyanate, and a blowing agent, and by mixing these, a reaction between the polyol and the polyisocyanate proceeds, making it possible to form a polyurethane foam. In this specification, the composition for forming a polyurethane foam of the present invention is also referred to as the composition of the present invention.

[0023] The polyol is a compound having a plurality of hydroxyl groups, and is preferably a polymer polyol. Specific examples of the polyol include polyether polyol, polyester polyol, polycarbonate polyol, polylactone polyol, polybutadiene polyol, polymer polyol, Mannich polyol, etc.

[0024] In the composition of the present invention, the amount of polyol is appropriately adjusted depending on the amount of polyisocyanate, and is, for example, 25 to 40 parts by mass per 100 parts by mass of the composition. The polyol may be used alone or in combination of two or more kinds.

[0025] A representative example of the polyether polyol is a polyoxyalkylene polyol. The polyoxyalkylene polyol can be produced by subjecting a compound having two or more hydroxyl groups, primary amino groups, secondary amino groups, or other active hydrogen-containing groups as a starting material to a ring-opening addition reaction with an alkylene oxide.

[0026] Starting materials for polyoxyalkylene polyols include polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, diglycerin, mannose, sucrose, fructose, dextrose, and sorbitol; alkanolamines such as ethanolamine, diethanolamine, triethanolamine, and methyldiethanolamine; polyhydric amines such as ethylenediamine, tolylenediamine, diethyltoluenediamine, 1,3-propanediamine, 1,6-hexanediamine, isophoronediamine, diethylenetriamine, and triethylenepentamine; polyhydric phenols such as bisphenol A, bisphenol F, resorcinol, and hydroquinone; and modified products thereof. These starting materials may be used alone or in combination of two or more.

[0027] When producing a polyoxyalkylene polyol, examples of the alkylene oxide to be subjected to a ring-opening addition reaction include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, and styrene oxide. These alkylene oxides may be used alone or in combination of two or more.

[0028] Examples of the polymer polyol include those in which polymer particles such as polyacrylonitrile particles or polystyrene particles are dispersed in a polyoxyalkylene polyol. Since the polymer polyol contains a polyoxyalkylene polyol, it is a type of polyether polyol.

[0029] Mannich polyols can be produced by condensation reaction of phenols, aldehydes, alkanolamines, etc., and further performing a ring-opening addition reaction of alkylene oxides such as ethylene oxide, propylene oxide, etc. Mannich polyols are a type of polyether polyols because they have multiple ether bonds in the molecule.

[0030] Examples of suitable polyether polyols include polyoxyalkylene polyols such as (di)ethylene glycol-based polyether polyols obtained by addition reaction of ethylene oxide and / or propylene oxide, (di)propylene glycol-based polyether polyols, (di)glycerin-based polyether polyols, trimethylolpropane-based polyether polyols, pentaerythritol-based polyether polyols, sucrose-based polyether polyols, dextrose-based polyether polyols, sorbitol-based polyether polyols, mono(di, tri)ethanolamine-based polyether polyols, ethylenediamine-based polyether polyols, tolylenediamine-based polyether polyols, and bisphenol A-based polyether polyols; polymer polyols in which polymer particles are dispersed in polyoxyalkylene-based polyols; and Mannich polyols.

[0031] The polyester polyol can be produced by adjusting the production conditions of the polyester, and examples thereof include polyester polyols having at least hydroxyl groups at both ends of the main chain, more specifically, linear polyester polyols, slightly branched polyester polyols, etc. The polyester polyol can be prepared by a known method using an aliphatic, alicyclic or aromatic dicarboxylic acid, a diol, and optionally a polyvalent carboxylic acid and / or a trifunctional or higher polyol.

[0032] The polylactone polyol is a homopolymer or copolymer of lactone, and examples thereof include polylactones having hydroxyl groups at both ends of the main chain. Specifically, the polylactone polyol can be produced by ring-opening addition reaction of lactones such as ε-caprolactone, β-butyrolactone, γ-butyrolactone, γ-valerolactone, and δ-valerolactone, starting from a compound having two or more active hydrogen-containing groups as described above in the polyoxyalkylene polyol. Note that polylactone polyols are a type of polyester polyols because they have multiple ester bonds in the molecule.

[0033] The polycarbonate polyol can be produced by adjusting the production conditions of the polycarbonate, and examples of the polycarbonate polyol include polycarbonate having at least hydroxyl groups at both ends of the main chain, and the polybutadiene polyol includes polybutadiene having at least hydroxyl groups at both ends of the main chain.

[0034] The composition of the present invention preferably contains a polyether polyol as a polyol. The amount of the polyether polyol is preferably 25 parts by mass or more, more preferably 25 to 40 parts by mass, and even more preferably 30 to 35 parts by mass, based on 100 parts by mass of the composition of the present invention. When the polyether polyol, particularly the polyether polyol having a high hydroxyl value that shows a relatively hydrophilic property, is used in the above-specified amount, the effect of the compound represented by formula 1 described later is easily exhibited.

[0035] In the composition of the present invention, the hydroxyl value of the polyol is preferably from 200 to 500 mgKOH / g, and more preferably from 300 to 400 mgKOH / g.

[0036] In this specification, the hydroxyl value refers to the number of milligrams of sodium hydroxide required to neutralize the free hydroxyl groups in 1 g of a sample after complete acetylation with a carboxylic anhydride (e.g., phthalic anhydride or acetic anhydride) (see JIS K 1557 2007).

[0037] In the composition of the present invention, the molecular weight of the polyol is preferably from 400 to 800 g / mol, and more preferably from 500 to 600 g / mol.

[0038] In this specification, the molecular weight of a polyol is a number average molecular weight calculated in terms of polystyrene as measured by gel permeation chromatography.

[0039] In the composition of the present invention, the functionality (fn) of the polyol is preferably 2.5 to 4.5, and more preferably 3.0 to 4.0.

[0040] In this specification, the number of functional groups (fn) per one molecule of polyol is calculated from the hydroxyl value (OHV) and number average molecular weight (Mn) of the polyol by the following formula. fn=Mn(g / mol)×OHV(mgKOH / g) / 56100

[0041] The viscosity of the polyol contained in the composition of the present invention is preferably 500 mPas (25°C) or more, more preferably 600 to 3000 mPas (25°C), and even more preferably 700 to 2000 mPas (25°C). If the viscosity of the polyol contained in the composition of the present invention is less than 500 mPas (25°C), the composition may splash during application, which may cause defects in the foam. The viscosity of the polyol can be easily increased, for example, by using an aromatic amine-based polyether polyol.

[0042] In this specification, the viscosity is measured in accordance with JIS K 7117-1:1999 using a Brookfield rotational viscometer type B.

[0043] When the composition of the present invention contains a plurality of polyols, the viscosity of the polyol is the viscosity of the entire polyol, and can be calculated, for example, from the viscosity and mass fraction of each polyol as follows. [Polyol Viscosity] When the composition of the present invention contains n types of polyols, the viscosity of each polyol is V1 , V 2 , , ,V n The mass fraction of each polyol in the entire polyol is W 1 , W 2 , , W n can be calculated using the following formula: Viscosity of polyol = exp(W 1 ×ln(V 1 )+W 2 ×ln(V 2 )+···+W n ×ln(V n ))

[0044] Polyisocyanates are compounds having a plurality of isocyanate groups, and examples thereof include aliphatic, alicyclic, aromatic, or araliphatic polyisocyanates, and also include modified products of these polyisocyanates. Examples of modified polyisocyanates include polyisocyanates having structures such as uretdione, isocyanurate, urethane, urea, allophanate, biuret, carbodiimide, iminooxadiazinedione, oxadiazinetrione, and oxazolidone. In addition, as the polyisocyanate, an isocyanate group-containing prepolymer obtained by reacting a polyol with a polyisocyanate may be used. The polyisocyanate may be used alone or in combination of two or more kinds.

[0045] Among the polyisocyanates, examples of aromatic polyisocyanates include phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, polymethylene polyphenyl polyisocyanate, etc. Examples of alicyclic polyisocyanates include cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, dimethyldicyclohexylmethane diisocyanate, etc. Examples of aliphatic polyisocyanates include methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, etc.

[0046] The polyisocyanate preferably has an isocyanate group content of 20 to 40 mass %, more preferably 25 to 35 mass %. In this specification, the isocyanate group content is determined in accordance with JIS K 1603-1:2007.

[0047] In the composition of the present invention, the amount of polyisocyanate can be indicated, for example, by the isocyanate index. In the composition of the present invention, from the viewpoint of the heat insulating property of the polyurethane foam, it is preferable that the isocyanate index is set low. Specifically, the isocyanate index is preferably 150 or less, more preferably 90 to 150, further preferably 90 to 130, and particularly preferably 100 to 125.

[0048] In this specification, the isocyanate index is a value obtained by multiplying by 100 the ratio of the isocyanate groups of a polyisocyanate to the total of active hydrogens that react with isocyanate groups of polyols, foaming agents, and the like.

[0049] The foaming agent is generally classified into a physical foaming agent and a chemical foaming agent. The foaming agent may be used alone or in combination of two or more kinds. A physical foaming agent and a chemical foaming agent may be used in combination. The amount of the foaming agent is preferably 0.5 to 15 parts by mass, more preferably 3 to 12 parts by mass, based on 100 parts by mass of the composition of the present invention.

[0050] Specific examples of physical blowing agents include fluorocarbons such as hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), hydrocarbons such as heptane, hexane, pentane, and cyclopentane, carbon dioxide, etc. On the other hand, specific examples of chemical blowing agents include water, and carboxylic acids such as formic acid and acetic acid, etc.

[0051] The composition of the present invention contains hydrofluoroolefin as a blowing agent. Hydrofluoroolefin (HFO) is a blowing agent that is suitably used as a physical blowing agent that does not fall under fluorocarbons. HFO is an olefin compound containing a fluorine atom, and also includes those that further contain a halogen atom other than fluorine (e.g., a chlorine atom). Among HFOs, those that further contain a chlorine atom are also called hydrochlorofluoroolefin (HCFO). The composition of the present invention preferably contains hydrochlorofluoroolefin. Note that HFO and HCFO may be distinguished, but in this specification, HFO includes HCFO as described above.

[0052] The hydrofluoroolefin preferably has 2 to 5 carbon atoms and 3 to 7 fluorine atoms. The molecular weight of the HFO is preferably 100 to 200 g / mol. Specific examples of the HFO include 1,2,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene, 1,2,3,3-tetrafluoropropene, 3,3,3-trifluoropropene, 1,1,1,4,4,4-hexafluorobutene, 1-chloro-3,3,3-trifluoropropene, 2-chloro-3,3,3-trifluoropropene, 3,3-dichloro-3-fluoropropene, 2-chloro-1,1,1,4,4,4-hexafluorobutene, and 2-chloro-1,1,1,3,4,4,4-heptafluorobutene. The HFO may be either a cis or trans isomer. These HFOs may be used alone or in combination of two or more.

[0053] The amount of the hydrofluoroolefin is, for example, 0.5 to 15 parts by mass, and preferably 3 to 12 parts by mass, relative to 100 parts by mass of the composition of the present invention.

[0054] From the viewpoint of improving the appearance and strength of the foam, the composition of the present invention preferably contains water as a blowing agent. The amount of water is, for example, 0.2 to 10 parts by mass, preferably 0.5 to 3 parts by mass, based on 100 parts by mass of the composition of the present invention.

[0055] The composition of the present invention comprises at least one compound represented by the following formula 1: RO(CH2CH2O) n R (Formula 1) [In the formula, R is a C1 to C3 linear or branched alkyl, and n is an integer of 1 or more.]

[0056] The composition of the present invention preferably contains a polyether polyol. The polyether polyol has hydrophilic properties that are easily soluble in water due to its structure. Therefore, as the reaction between the polyol and the polyisocyanate proceeds, a hydrophobic structure is formed, but the hydrophilicity is maintained to a certain extent.

[0057] On the other hand, hydrofluoroolefin (HFO) used as a foaming agent is hydrophobic, so it moves to the hydrophobic side during the reaction process between polyol and polyisocyanate. As the reaction heat gradually increases, HFO also volatilizes, but if there are many hydrophilic structures such as polyether polyol, HFO is difficult to dissolve, so HFO volatilizes all at once in the early stages of the reaction. When HFO volatilizes all at once, the resin becomes soft in certain places due to the high solubility of HFO in resin, and this softness is thought to cause the foam to shrink and lose the smoothness of the surface of the facing material.

[0058] The compound represented by the above formula 1 is relatively hydrophobic, and therefore, for example, it is possible to control the dissolution of HFO into a resin obtained from a raw material containing a hydrophilic polyether polyol, thereby solving the problem of the resin becoming soft at specific locations.

[0059] In the above formula 1, R is a C1 to C3 linear or branched alkyl, specific examples of which include methyl, ethyl, and propyl (normal propyl, isopropyl). The two R in formula 1 may be the same or different.

[0060] In the above formula 1, n is an integer of 1 or more, preferably an integer of 1 or more and 12 or less, and more preferably an integer of 5 or more and 10 or less.

[0061] The amount of the compound represented by the above formula 1 is preferably 0.2 to 6 parts by mass, and more preferably 0.5 to 3 parts by mass, relative to 100 parts by mass of the composition of the present invention. If the amount of the compound represented by the above formula 1 is too large, the compound tends to come out to the surface, and the flammability is reduced, making the composition more flammable.

[0062] The composition of the present invention preferably contains a catalyst, such as a catalyst (foaming catalyst) that promotes the reaction between water and polyisocyanate, a catalyst (resinification catalyst) that promotes the reaction between polyol and polyisocyanate, and a catalyst (trimerization catalyst) that promotes the trimerization reaction of polyisocyanate (i.e., the formation of an isocyanurate ring).

[0063] Examples of foaming catalysts include dimorpholine-2,2-diethyl ether, N,N,N',N'',N''-pentamethyldiethylenetriamine, bis(dimethylaminoethyl)ether, 2-(2-dimethylaminoethoxy)ethanol, and N,N,N'-trimethyl-N'-hydroxyethyl bisaminoethyl ether.

[0064] Examples of the resinification catalyst include triethylenediamine, N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'',N''',N'''-hexamethyltriethylenetetramine, N-dimethylaminoethyl-N'-methylpiperazine, N,N,N',N'-tetramethylhexamethylenediamine, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, N,N-dimethylaminopropylamine, and bis(dimethylaminopropyl)amine. Examples of suitable catalysts include amine catalysts such as N,N-dimethylaminoethanol, N,N,N'-trimethylaminoethylethanolamine, N-(3-dimethylaminopropyl)-N,N-diisopropanolamine, N-(2-hydroxyethyl)-N'-methylpiperazine, N,N-dimethylaminohexanol, and 5-dimethylamino-3-methyl-1-pentanol, as well as metal catalysts such as stannous octoate, dibutyl stannous dilaurate, lead octoate, bismuth carboxylate, and zirconium complexes. As these amine catalysts and alkanolamine catalysts, amine carbonates synthesized by adding carbonic acid and amine carboxylates synthesized by adding carboxylic acids such as formic acid and acetic acid may be used.

[0065] Examples of the trimerization catalyst include aromatic compounds such as 2,4,6-tris(dialkylaminoalkyl)hexahydro-s-triazine, 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-s-triazine, 2,4,6-tris(dimethylaminomethyl)phenol, and 2,4-bis(dimethylaminomethyl)phenol; alkali metal salts of carboxylic acids such as potassium acetate, potassium 2-ethylhexanoate, and potassium octylate; quaternary ammonium salts of carboxylic acids; and other onium salts.

[0066] The amount of the catalyst is, for example, 0.1 to 5 parts by mass, and preferably 0.3 to 1.5 parts by mass, based on 100 parts by mass of the composition of the present invention. The catalyst may be used alone or in combination of two or more kinds.

[0067] The composition of the present invention may contain a foam stabilizer. The foam stabilizer is preferably a surfactant. The surfactant may be an ionic surfactant such as anionic, cationic, or amphoteric surfactant, or a nonionic surfactant, and the nonionic surfactant is preferable. In addition, specific examples of the surfactant include silicone surfactants and fluorine surfactants. The amount of the foam stabilizer is preferably 1 to 5 parts by mass relative to 100 parts by mass of the composition of the present invention. The foam stabilizer may be used alone or in combination of two or more kinds.

[0068] The composition of the present invention may contain a flame retardant. The flame retardant is preferably a phosphorus-based flame retardant. Specific examples include tricresyl phosphate (TCP), triethyl phosphate (TEP), tris(β-chloroethyl) phosphate (TCEP), tris(β-chloropropyl) phosphate (TCPP), etc. In addition, solid (powder) flame retardants such as ammonium polyphosphate and red phosphorus may also be used as needed. The amount of the flame retardant is preferably 3 to 15 parts by mass relative to 100 parts by mass of the composition of the present invention. The flame retardant may be used alone or in combination of two or more kinds.

[0069] The composition of the present invention may contain, as other components, additives such as colorants, fillers, antioxidants, ultraviolet absorbers, heat stabilizers, light stabilizers, plasticizers, fungicides, antibacterial agents, crosslinking agents, solvents, viscosity reducers, pressure reducing agents, and separation inhibitors, etc. Commercially available products can be suitably used for these components.

[0070] The composition of the present invention can be prepared by mixing various components appropriately selected as necessary. For example, the composition of the present invention can be prepared by mixing a polyol component containing a polyol and a polyisocyanate component containing a polyisocyanate.

[0071] The composition of the present invention is often composed of a stock solution consisting of a pair of a polyol component and a polyisocyanate component. The polyol component contains a polyol, and usually contains a foaming agent, a foam stabilizer, and a catalyst, and may contain a flame retardant or further additives. The polyisocyanate component is composed of a polyisocyanate, but may contain additives such as a foaming agent and a flame retardant. The foaming agent may be added when the polyol component and the polyisocyanate component are mixed.

[0072] Another aspect of the present invention is a polyurethane foam. The polyurethane foam of the present invention is produced by foaming the polyurethane foam-forming composition of the present invention described above. Since the composition of the present invention contains a polyol and a polyisocyanate, the reaction proceeds by mixing the two, and it is possible to form a polyurethane foam. The temperature during polyurethane foam formation is preferably 20 to 80°C.

[0073] The foaming method of the polyurethane foam is not particularly limited, and known foaming means such as hand mixing foaming, simple foaming, injection method, froth injection method, spray method, etc. The molding method of the polyurethane foam is also not particularly limited, and known molding means such as mold molding, slab molding, laminate molding, in-situ foam molding, etc. can be used.

[0074] The polyurethane foam of the present invention can be used for various applications such as ships, vehicles, plants, thermally insulated equipment, architecture, civil engineering, furniture, and interior design, and is preferably used as a thermal insulation material, specifically as a thermal insulation component for thermally insulated equipment, for example, a refrigerated warehouse or a frozen warehouse.

[0075] The polyurethane foam of the present invention is preferably a polyurethane foam with a facing material, more preferably a polyurethane foam with a metal facing material. In this specification, a facing polyurethane foam refers to a plate-shaped composite material in which a facing material such as a foil or a plate is attached to one or both sides of a polyurethane foam, and can be used as a heat insulating material for various purposes.

[0076] Suitable examples of the adherend such as a surface material include metals and other inorganic materials, particularly aluminum and its alloys, stainless steel and its alloys, iron and its alloys, copper and its alloys, etc. Furthermore, the surface of the adherend to which the composition of the present invention is to be attached may be coated as desired. Examples of the coating include organic polymer coating agents such as polyester resins. The thickness of the adherend is preferably 0.2 to 0.6 mm.

[0077] The polyurethane foam of the present invention has a density of, for example, 5 to 80 kg / m 3 25-70kg / m 3 is preferably 40 to 65 kg / m 3 In this specification, the density of the polyurethane foam is measured in accordance with JIS K 7222:2005.

[0078] The polyurethane foam of the present invention preferably has a thermal conductivity of 0.0185 to 0.0280 W / m·K, and more preferably 0.0190 to 0.0260 W / m·K, when the measurement center temperature is 23° C. In this specification, the thermal conductivity is measured in accordance with JIS A 1412-2:1999.

[0079] The polyurethane foam of the present invention can be suitably applied to various applications requiring heat insulation, and in particular, the polyurethane foam of the present invention can be advantageously used as a construction material or heat insulation material for various facilities such as collective housing such as apartment buildings, detached houses, schools, and commercial buildings, as well as for cold storage warehouses, bathtubs, factory piping, and automobiles and railroad cars.

[0080] The polyurethane foam of the present invention can also be used for producing thermal insulation materials and condensation prevention materials for on-site application by a spray method, and for producing building materials such as panels and boards in a factory line. Thus, according to one embodiment of the present invention, the polyurethane foam is a spray-applied rigid polyurethane foam for building insulation as specified in JIS A 9526:2017.

[0081] Another aspect of the present invention is a heat insulating material. The heat insulating material of the present invention is a heat insulating material made of the polyurethane foam of the present invention described above. Examples of the heat insulating material include heat insulating components for heat insulating equipment, such as refrigerated warehouses and freezer warehouses. The heat insulating material of the present invention can be used in various facilities such as collective housing such as condominiums, detached houses, schools and commercial buildings, freezer warehouses, bathtubs, factory piping, automobiles and railroad cars. EXAMPLES

[0082] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0083] 1. Overview Using a high-pressure foaming machine, a mixture of polyol and foaming agent (polyol component) is mixed with polyisocyanate at a specified ratio, and the mixture is discharged at a certain temperature and pressure into a mold with metal facing materials arranged above and below to obtain polyurethane foam, and after a certain time the depth near the injection point on the bottom surface is measured.

[0084] 2. Apparatus and Equipment High pressure foaming machine (HK-650P, Hennecke) Disposable chopsticks Stopwatch (with lap function) Mold (aluminum, inner dimensions: length 2000mm, width 900mm, thickness 100mm)

[0085] 3.Material 1) Polyol Polyol A: Polyether polyol [SBU Polyol 0517: manufactured by Sumika Covestro Urethane Co., Ltd.], functionality: 4.1, hydroxyl value: 480 mg KOH / g, viscosity: 3400 mPa·s (25°C) Polyol B: Polyether polyol [SBU Polyol 0487: manufactured by Sumika Covestro Urethane Co., Ltd.], number of functional groups: 4, hydroxyl value 410 mg KOH / g, viscosity 1500 mPa s (25°C) Polyol C: Aromatic amine-based polyether polyol [SBU Polyol Z450: manufactured by Sumika Covestro Urethane Co., Ltd.], functionality: 4, hydroxyl value: 340 mg KOH / g, viscosity: 12,000 mPa·s (25°C) Polyol D: Polyether polyol [SBU Polyol S429: manufactured by Sumika Covestro Urethane Co., Ltd.], number of functional groups: 3, hydroxyl value 250 mg KOH / g, viscosity 230 mPa s (25°C) 2) Polyisocyanate Polyisocyanate: Polymeric MDI [Sumidur 44V20 L: manufactured by Sumika Covestro Urethane Co., Ltd.], isocyanate group content: 31.5% by mass 3) Foaming agent Blowing agent A: Water Foaming agent B: HCFO-1233zd (molecular weight 130) Foaming agent C: HFO-1224yd (molecular weight 148.5) Foaming agent D: HFO-1336mzz(Z) (molecular weight 164) 4) Compatibilizer Compatibilizer A: Diethylene glycol dimethyl ether, molecular weight 134, viscosity 1 mPa·s (25°C) Compatibilizer B: Tetraethylene glycol dimethyl ether, molecular weight 222, viscosity 4 mPa·s (25°C) Compatibilizer C: Polyoxyethylene-dimethyl ether [UNIOX MM-400: NOF Corporation], average molecular weight 400, viscosity 100 mPa·s (25°C) Compatibilizer D: Diethylene glycol monobutyl ether, molecular weight 162, hydroxyl value 346, viscosity 6 mPa·s (25°C) Compatibilizer E: Ethyl diglycol acetate, molecular weight 176, viscosity 2.5 mPa·s (25°C) 4) Other additives Catalyst A: Dimorpholine-2,2-diethyl ether Catalyst B: 70% by mass of 1,2-dimethylimidazole + 30% by mass of diethylene glycol Foam stabilizer: Silicone-based non-ionic surfactant [TEGOSTAB B8460: Evonik Japan Co., Ltd.] Flame retardant: Tris(2-chloroisopropyl)phosphate 5) Surface material Aluminum surface material

[0086] 3. Method <Preparation of polyol component> 1) Put the specified amounts of various polyols and catalysts, etc. into a nitrogen-purged mixing vessel and mix them. 2) Stir for at least 30 minutes and visually check that the mixture is thoroughly mixed. 3) Add the foaming agent to the mixture confirmed in 2) until the specified amount is reached, and mix thoroughly. After mixing, add the weighed amount of foaming agent and mix again. The blending recipe (parts by mass) of the polyol component is shown in Tables 1-2. <Production of polyurethane foam> 4) Using a high-pressure foaming machine HK-650P manufactured by Hennecke, the polyol component and polyisocyanate component were adjusted to 19 to 23°C, and urethane injection molding was performed at a discharge pressure of 12 MPa. The mixing mass ratio of the polyol component and the polyisocyanate component is shown in Tables 1 and 2. 5) The foam-forming composition is poured into a single point at the center of a mold (inner dimensions: length 2000 mm, width 900 mm, thickness 100 mm) that has been preheated to 40°C and has aluminum panels arranged above and below. 6) Inject polyurethane foam in the length direction of the mold so that it does not completely clog the mold. Cut off both ends of the semicircle to sample a rectangular parallelepiped. Then measure the weight and volume and determine the just density (kg / m 3 The density of the sample filled in the mold is called the just density. 7) From the just density, calculate the just weight of the mold (inner dimensions: length 2000 mm, width 900 mm, thickness 100 mm), and inject 1.25 times that amount of foam to produce a polyurethane foam molded product. 8) 20 minutes after the foam-forming composition is injected, the polyurethane foam molding with the facing is removed from the mold. 9) After removing the polyurethane foam, place it under 0°C conditions within 30 minutes, and then leave it for approximately 24 hours. 10) Place a straight ruler at a right angle on the underside of the surface material where the urethane has been injected, and measure the maximum gap between the straight ruler and the surface material using a thickness gauge (Niigata Seiki Co., Ltd. 100ML) or a taper gauge (Niigata Seiki Co., Ltd. 270A). The results obtained are shown in Tables 1 and 2 as the "maximum concavity of the injected underside." 11) For the lower surface of the panel, the image of the fluorescent light (straight tube type) reflected on the panel was visually observed and the smoothness was evaluated according to the following criteria. The evaluation results are shown in Tables 1 and 2. (Evaluation Criteria) : The surface was smooth and the image of the fluorescent light was visible as a straight line. ◯: The surface was smooth and the image of the fluorescent light was seen as a straight line, but there appeared to be slight irregularities. ×: The surface was not smooth, and wavy patterns of the fluorescent light image were visible.

[0087] <How to measure gel time> In order to confirm the reactivity of the foam-forming composition, a certain amount of the composition was poured into a 2 L death cup at a certain temperature and pressure, and the time until the mixture started to form threads when touched with chopsticks after pouring was measured as the gel time (seconds). The measurement results are shown in Tables 1 and 2.

[0088] <Combustibility evaluation> In accordance with JIS A 9511:2017, test pieces with a thickness of 10 mm, length of 200 mm, and width of 25 mm were used and evaluated according to the following criteria. The measurements were performed by cutting test pieces of the above dimensions from the manufactured polyurethane foam and measuring them at standard temperature condition class 3 (23°C ± 5°C) and standard humidity condition class 3 (50°C ± 5°C) as specified in JIS K 7100:1999. +20、-10 The samples were left to stand under conditions of 50°C (RH = 20°F) and 1% (RH) for one week after production. The evaluation results are shown in Tables 1 and 2. (Evaluation Criteria) ○ (Pass): The flame goes out within 3 seconds, there is no residual fuel, and the fire does not burn beyond the flammability limit indicator line. × (Fail): Does not meet the above pass criteria.

[0089] [Table 1]

[0090] [Table 2]

[0091] It can be seen from Tables 1 and 2 that the polyurethane foams of the Examples have superior surface quality of the molded articles compared to Comparative Examples 1 and 5 to 8. It can also be seen that the polyurethane foams of Comparative Examples 2 to 4 have poor flammability because the amount of the compound represented by formula 1 used was too large.

Claims

1. A composition for forming a polyurethane foam, comprising a hydrofluoroolefin as a blowing agent and 0.2 to 6 parts by mass of at least one compound represented by the following formula 1, per 100 parts by mass of the composition: RO(CH ２ CH ２ O) ｎ R (Formula 1) [In the formula, R is a C1-C3 linear or branched alkyl, and n is an integer of 1 or more.]

2. The composition according to claim 1 , comprising at least 25 parts by weight of polyether polyol per 100 parts by weight of the composition.

3. 3. The composition of claim 1 or 2, having an isocyanate index of 150 or less.

4. The composition according to any one of claims 1 to 3, wherein the viscosity of the polyol contained in the composition is 500 mPas (25°C) or more.

5. A polyurethane foam obtained by foaming the composition according to any one of claims 1 to 4.

6. The polyurethane foam according to claim 5, which is a faced polyurethane foam.

7. A heat insulating material comprising the polyurethane foam according to claim 5 or 6.

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