Polyurethane foam-forming composition, polyurethane foam additive, and polyurethane foam

Abstract

The polyurethane foam-forming composition contains a polyol, a polyisocyanate, and at least one aromatic compound selected from the group consisting of compounds represented by formula (1) and compounds represented by formula (2). [In the formulae, R1 represents a C1-3 aliphatic hydrocarbon group, R2 represents a hydrogen atom or a methyl group, L represents a single bond or a methylene group, n represents 1 or 2, and m represents an integer of 0 or 1 or more.]

Description

Polyurethane foam-forming composition, polyurethane foam additive, and polyurethane foam

[0001] The present disclosure relates to polyurethane foam additives, polyurethane foam-forming compositions, and polyurethane foams.

[0002] Polyurethane foams are widely used as insulation materials for refrigerators, freezer warehouses, building materials, etc., due to their excellent thermal insulation performance, dimensional stability, workability, etc. On the other hand, polyurethane foams have a problem in that their thermal conductivity increases over time (i.e., their thermal insulation performance decreases over time).

[0003] In response to this, for example, Patent Document 1 discloses a method of suppressing deterioration over time of the thermal conductivity of polyurethane foam, particularly deterioration over time of thermal conductivity in the early stages when the change is large, by after-aging the molded polyurethane foam in amine or alcohol vapor.

[0004] Japanese Patent Application Laid-Open No. 2002-302528

[0005] However, the method of Patent Document 1 requires complicated manufacturing steps and increases the manufacturing cost. Therefore, a technology for obtaining a polyurethane foam that can maintain low thermal conductivity for a long period of time without including complicated manufacturing steps is desired.

[0006] Therefore, one aspect of the present disclosure is to provide a polyurethane foam-forming composition for forming a polyurethane foam in which the increase in thermal conductivity over time is suppressed. Another aspect of the present disclosure is to provide a polyurethane foam additive that can suppress the increase in thermal conductivity of the polyurethane foam over time. Another aspect of the present disclosure is to provide a polyurethane foam in which the increase in thermal conductivity over time is suppressed.

[0007] Some aspects of the present disclosure provide the following [1] to [8].

[0008] [1] A polyurethane foam-forming composition comprising a polyol, a polyisocyanate, and at least one aromatic compound selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2): [In formula (1), R １ represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and R ２ represents a hydrogen atom or a methyl group, L represents a single bond or a methylene group, and n represents 1 or 2. １ When a plurality of are present, they may be the same or different, and when a plurality of L are present, they may be the same or different. [In formula (2), R １ is R in the formula (1). １ and m represents an integer of 0 or 1 or more. １ may be the same or different from each other.

[0009] [2] The polyurethane foam-forming composition according to [1], comprising a reaction product of at least one isocyanate selected from the group consisting of phenyl isocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and polymethylene polyphenyl polyisocyanate with an aliphatic monoalcohol having 1 to 3 carbon atoms.

[0010] [3] The polyurethane foam-forming composition according to [1] or [2], wherein the polyol comprises an aromatic polyester polyol.

[0011] [4] The polyurethane foam-forming composition according to any one of [1] to [3], further comprising at least one selected from the group consisting of a catalyst, a foam stabilizer, and a blowing agent.

[0012] [5] An additive for polyurethane foams, comprising at least one aromatic compound selected from the group consisting of compounds represented by the following formula (1) and compounds represented by the following formula (2): [In formula (1), R １ represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and R ２represents a hydrogen atom or a methyl group, L represents a single bond or a methylene group, and n represents 1 or 2. １ When a plurality of are present, they may be the same or different, and when a plurality of L are present, they may be the same or different. [In formula (2), R １ is R in the formula (1). １ and m represents an integer of 0 or 1 or more. １ may be the same or different from each other.

[0013] [6] The polyurethane foam additive according to [5], which contains a reaction product of at least one isocyanate selected from the group consisting of phenyl isocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and polymethylene polyphenyl polyisocyanate with an aliphatic monoalcohol having 1 to 3 carbon atoms.

[0014] [7] The additive for polyurethane foam according to [5] or [6], which is a thermal conductivity modifier.

[0015] [8] A polyurethane foam formed from the polyurethane foam-forming composition according to any one of [1] to [4].

[0016] According to one aspect of the present disclosure, there is provided a polyurethane foam-forming composition for forming a polyurethane foam in which an increase in thermal conductivity over time is suppressed. According to another aspect of the present disclosure, there is provided a polyurethane foam additive that can suppress an increase in the thermal conductivity of the polyurethane foam over time. According to another aspect of the present disclosure, there is provided a polyurethane foam in which an increase in thermal conductivity over time is suppressed.

[0017] In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. Furthermore, unless specifically stated otherwise, the units of the numerical values ​​before and after "to" are the same. In the numerical ranges described in stages in this specification, the upper limit or lower limit of a numerical range in a certain stage may be replaced with the upper limit or lower limit of a numerical range in another stage. Furthermore, in the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with a value shown in the examples. Furthermore, the upper limit and lower limit values ​​described individually can be combined in any combination.

[0018] Preferred embodiments of the present disclosure will be described below, but the present disclosure is not limited to the following embodiments.

[0019] <Additive for Polyurethane Foam> One embodiment of the present disclosure is an additive for polyurethane foam (hereinafter also referred to as “additive A”) containing at least one aromatic compound selected from the group consisting of aromatic compound A and aromatic compound B.

[0020] (Aromatic Compound A) Aromatic compound A is a compound represented by the following formula (1).

[0021] R in formula (1) １ represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms. The aliphatic hydrocarbon group preferably has 1 to 2 carbon atoms, and more preferably 1 carbon atom.

[0022] The aliphatic hydrocarbon group may be linear or branched, and may be saturated or unsaturated.

[0023] The aliphatic hydrocarbon group is preferably an alkyl group, more preferably a linear alkyl group. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and an isopropyl group.

[0024] In formula (1), R １ When there are a plurality of groups, they may be the same or different.

[0025] R in formula (1)２ represents a hydrogen atom or a methyl group. ２ is preferably a hydrogen atom. ２ is a methyl group, the group in the parentheses in formula (1) (—NHCOOR １ ) is R ２ It may be located at any of the ortho, meta, and para positions.

[0026] In formula (1), L represents a single bond or a methylene group. When a plurality of Ls are present in formula (1), they may be the same or different.

[0027] In formula (1), n ​​represents 1 or 2. n is preferably 1. When n is 2, the group (—NHCOOR １ ) can be in the ortho, meta, or para position relative to each other.

[0028] As the aromatic compound A, one compound may be used alone, or two or more compounds may be used in combination.

[0029] (Aromatic Compound B) Aromatic compound B is a compound represented by the following formula (2).

[0030] R in formula (2) １ is R in the above formula (1) １ The preferred examples thereof are also the same. １ may be the same or different from each other.

[0031] In formula (2), m represents an integer of 0 or greater than 1. The upper limit of m may be 8, for example.

[0032] Aromatic compound B may be used singly or in combination of two or more. For example, a mixture of a compound (binuclear compound) in which m in formula (2) is 0 and a compound (polynuclear compound) in which m in formula (2) is 1 or more may be used as aromatic compound B. The content of the dinuclear compound in the mixture may be 20 to 100% by mass, 30 to 80% by mass, or 40 to 70% by mass based on the total mass of the mixture.

[0033] The additive A may contain only one of the aromatic compound A and the aromatic compound B, or may contain both the aromatic compound A and the aromatic compound B. The aromatic compound A and the aromatic compound B may be solid or liquid at room temperature (23°C). When the aromatic compound A and the aromatic compound B are solid at room temperature, they preferably have solubility in polyol and / or polyisocyanate, and more preferably have solubility in aromatic polyester polyol.

[0034] From the viewpoint of enhancing the effect of additive A, the content of aromatic compound A may be 80% by mass or more (for example, 80 to 100% by mass), 90% by mass or more, or 95% by mass or more, based on the total mass of additive A.

[0035] From the viewpoint of enhancing the effect of additive A, the content of aromatic compound B may be 80% by mass or more (for example, 80 to 100% by mass), 90% by mass or more, or 95% by mass or more, based on the total mass of additive A.

[0036] From the viewpoint of enhancing the effect of additive A, the total content of aromatic compound A and aromatic compound B may be 80% by mass or more (for example, 80 to 100% by mass), 90% by mass or more, or 95% by mass or more, based on the total mass of additive A. When additive A contains aromatic compound A and aromatic compound B, the content of aromatic compound A may be 10 to 90% by mass, 20 to 80% by mass or more, or 30 to 70% by mass, based on the total content of aromatic compound A and aromatic compound B.

[0037] The additive A may consist solely of the aromatic compound A and / or the aromatic compound B, or may contain components other than the aromatic compound A and the aromatic compound B (for example, components that may be unavoidably mixed in during the production process of the aromatic compounds).

[0038] In one embodiment, additive A preferably comprises a reaction product (hereinafter referred to as "reaction product A") of at least one isocyanate selected from the group consisting of phenyl isocyanate, tolylene diisocyanate, diphenylmethane diisocyanate (hereinafter referred to as "MDI"), and polymethylene polyphenyl polyisocyanate with an aliphatic monoalcohol having 1 to 3 carbon atoms. Here, the aliphatic monoalcohol having 1 to 3 carbon atoms is represented by the formula: R １ The R of aliphatic monoalcohol is a compound represented by OH. １ is R in the above formula (1). １ The polymethylene polyphenyl polyisocyanate has the same meaning as above, and preferred examples thereof are also the same. Furthermore, polymethylene polyphenyl polyisocyanate is a compound represented by the following formula (3).

[0039] In formula (3), l represents an integer of 1 or greater. The upper limit of l may be 8, for example.

[0040] MDI exists in three isomers: 4,4'-diphenylmethane diisocyanate (hereinafter referred to as "4,4'-MDI"), 2,4'-diphenylmethane diisocyanate (hereinafter referred to as "2,4'-MDI"), and 2,2'-diphenylmethane diisocyanate (hereinafter referred to as "2,2'-MDI"). As MDI, one of these may be used alone, or two or more may be used in combination.

[0041] The content of 4,4'-MDI in MDI may be, for example, 40 to 100% by mass, 60 to 100% by mass, or 80 to 100% by mass, based on the total amount of MDI. The content of 2,4'-MDI in MDI may be, for example, 0 to 60% by mass, based on the total amount of MDI. The content of 2,2'-MDI in MDI may be, for example, 0 to 5% by mass, based on the total amount of MDI.

[0042] The reaction product A contains at least one of an aromatic compound A and an aromatic compound B. The reaction product A may contain a compound other than the aromatic compound A and the aromatic compound B (for example, a compound in which some of the multiple isocyanate groups (—NCO) in formula (3) remain unreacted), but the total content of the aromatic compound A and the aromatic compound B in the reaction product A is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0043] Reaction product A may be a reaction product between multiple types of isocyanates and an aliphatic monoalcohol having 1 to 3 carbon atoms. For example, reaction product A may be a reaction product between polymeric MDI, which is a mixture of diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate, and an aliphatic monoalcohol having 1 to 3 carbon atoms.

[0044] The MDI content in the polymeric MDI may be 20 to 99% by mass, 30 to 80% by mass, or 40 to 70% by mass, based on the total mass of the polymeric MDI.

[0045] The isocyanate group content of the polymeric MDI may be 27 to 33 mass %, 28 to 32 mass %, or 29 to 32 mass %, based on the total mass of the polymeric MDI.

[0046] From the viewpoint of enhancing the effect of additive A, the content of reaction product A may be 85% by mass or more (for example, 85 to 100% by mass) based on the total mass of additive A, or may be 90% by mass or more, or 95% by mass or more.

[0047] The additive A described above has the function of suppressing the deterioration of the thermal insulation performance of polyurethane foam (particularly rigid polyurethane foam) over time. Therefore, additive A can also be called a thermal conductivity modifier for polyurethane foam (or an agent for suppressing the increase in thermal conductivity of polyurethane foam over time). However, because additive A may have effects other than the effect of suppressing the increase in thermal conductivity of polyurethane foam over time, it does not necessarily have to be used for the purpose of modifying the thermal conductivity (suppressing the increase in thermal conductivity over time).

[0048] <Polyurethane Foam-Forming Composition> Another embodiment of the present disclosure is a polyurethane foam-forming composition (hereinafter also referred to as "composition A") comprising a polyol, a polyisocyanate, and at least one aromatic compound selected from the group consisting of aromatic compound A and aromatic compound B. Here, "polyurethane foam-forming" means that the composition has the property of being able to form a polyurethane foam by itself.

[0049] (Polyol) Polyol is a compound having two or more hydroxyl groups. Examples of polyols include polyester polyol, polyether polyol, polycaprolactone polyol, polycarbonate polyol, etc. One type of polyol may be used alone, or multiple types may be used in combination.

[0050] As the polyol, an aromatic polyester polyol is preferably used from the viewpoint of easily obtaining higher heat insulating performance (initial and long-term heat insulating properties). Here, the aromatic polyester polyol is a polyester polyol having an aromatic ring in the molecule. The aromatic polyester polyol may be, for example, a polyester polyol obtained by a condensation polymerization reaction between an acid component containing at least one selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, and anhydrides thereof and a polyfunctional alcohol.

[0051] The polyfunctional alcohol is preferably a low-molecular-weight polyol having a molecular weight of not more than 500. Examples of polyfunctional alcohols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimer diol, an ethylene oxide or propylene oxide adduct of bisphenol A, bis(β-hydroxyethyl)benzene, xylylene glycol, glycerin, trimethylolpropane, and pentaerythritol.

[0052] As the aromatic polyester polyol, a condensation polymerization reaction product of an acid component containing at least one of phthalic acid, isophthalic acid, terephthalic acid, or anhydrides thereof, and a polyfunctional alcohol containing at least one selected from the group consisting of ethylene glycol and diethylene glycol is preferably used, from the viewpoint of making it easier to obtain higher heat insulating performance (initial and long-term heat insulating properties).

[0053] From the viewpoint of making it easier to obtain higher heat insulating performance (initial and long-term heat insulating properties), the number average molecular weight of the polyol may be 300 to 1500, 350 to 1000, or 400 to 700. The number average molecular weight of the polyol is a polystyrene-equivalent number average molecular weight measured using gel permeation chromatography (GPC).

[0054] The hydroxyl value of the polyol may be 70 to 800 mgKOH / g, 100 to 650 mgKOH / g, or 150 to 450 mgKOH / g, from the viewpoint of making it easier to obtain higher heat insulating performance (initial and long-term heat insulating properties). The hydroxyl value is a value measured in accordance with JIS K1557-1.

[0055] The content of the polyol may be 10 to 50 mass %, 15 to 45 mass %, or 20 to 40 mass %, based on the total mass of composition A.

[0056] (Polyisocyanate) Polyisocyanate is a compound having a plurality of isocyanate groups. Examples of polyisocyanate include diphenylmethane diisocyanate (MDI), polyphenylene polymethylene polyisocyanate, and various modified products of MDI or polyphenylene polymethylene polyisocyanate (urethane modified product, urea modified product, allophanate modified product, nurate modified product, biuret modified product, etc.). One type of polyisocyanate may be used alone, or multiple types may be used in combination.

[0057] The content of the polyisocyanate may be 30 to 70 mass %, 35 to 65 mass %, or 40 to 60 mass %, based on the total mass of composition A.

[0058] (Aromatic Compound) Details of the aromatic compound A and the aromatic compound B are the same as those of the aromatic compound A and the aromatic compound B described above. When the aromatic compound A and the aromatic compound B are solid at room temperature, they preferably have solubility in the polyol and / or polyisocyanate contained in the composition A.

[0059] Aromatic compound A and aromatic compound B may be contained in composition A as components of an additive for polyurethane foam (e.g., a thermal conductivity modifier). In other words, composition A may contain additive A.

[0060] Composition A may contain only one of aromatic compound A and aromatic compound B, or may contain both aromatic compound A and aromatic compound B.

[0061] The content of aromatic compound A may be 0.1 to 20% by mass, based on the total mass of composition A. When the content of aromatic compound A is 0.1% by mass or more, there is a tendency for the increase in thermal conductivity of the polyurethane foam over time to be further suppressed, while when it is 20% by mass or less, there is a tendency for the increase in thermal conductivity of the polyurethane foam over time to be suppressed without impairing the mechanical properties of the polyurethane foam. From the same viewpoint, the content of aromatic compound A may be 0.5% by mass or more or 1% by mass or more, based on the total mass of composition A, and may be 15% by mass or less or 10% by mass or less. In one embodiment, the content of aromatic compound A based on the total amount of polyol, polyisocyanate, and aromatic compound A may be within the above range (e.g., 0.1 to 20% by mass).

[0062] The content of aromatic compound B may be 0.1 to 20% by mass, based on the total mass of composition A. When the content of aromatic compound B is 0.1% by mass or more, there is a tendency for the increase in thermal conductivity of the polyurethane foam over time to be further suppressed, while when it is 20% by mass or less, there is a tendency for the increase in thermal conductivity of the polyurethane foam over time to be suppressed without impairing the mechanical properties of the polyurethane foam. From the same viewpoint, the content of aromatic compound B may be 0.5% by mass or more or 1% by mass or more, based on the total mass of composition A, and may be 15% by mass or less or 10% by mass or less. In one embodiment, the content of aromatic compound B, based on the total amount of polyol, polyisocyanate, and aromatic compound B, may be within the above range (e.g., 0.1 to 20% by mass).

[0063] The total content of aromatic compound A and aromatic compound B may be 0.1 to 20% by mass, based on the total mass of composition A. When the total content of aromatic compound A and aromatic compound B is 0.1% by mass or more, there is a tendency for the increase in thermal conductivity of the polyurethane foam over time to be more effectively suppressed, while when it is 20% by mass or less, there is a tendency for the increase in thermal conductivity of the polyurethane foam over time to be suppressed without impairing the mechanical properties of the polyurethane foam. From the same viewpoint, the total content of aromatic compound A and aromatic compound B may be 0.5% by mass or more or 1% by mass or more, and may be 15% by mass or less or 10% by mass or less, based on the total mass of composition A. In one embodiment, the content of additive A may be within the above range (e.g., 0.1 to 20% by mass), the contents of aromatic compound A and aromatic compound B based on the total amount of polyol, polyisocyanate, aromatic compound A, and aromatic compound B may be within the above range (e.g., 0.1 to 20% by mass), and the content of additive A based on the total amount of polyol, polyisocyanate, and additive A may be within the above range (e.g., 0.1 to 20% by mass).

[0064] When composition A contains aromatic compound A and aromatic compound B, the content of aromatic compound A may be 10 to 90 mass%, 20 to 80 mass% or more, or 30 to 70 mass%, based on the total content of aromatic compound A and aromatic compound B.

[0065] (Other Components) Composition A may contain, as other components, polyurethane foam and known components used for forming the same. Specific examples of other components include catalysts, flame retardants, blowing agents, foam stabilizers, plasticizers, colorants, etc. Note that the other components are optional components and are not necessarily required.

[0066] [Catalyst] As the catalyst, various urethanization catalysts, isocyanuration catalysts, etc. known in the art can be used. A urethanization catalyst and an isocyanuration catalyst (trimerization catalyst) may be used in combination.

[0067] Examples of urethanization catalysts include triethylenediamine, N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'',N"-pentamethyldiethylenetriamine, N,N,N',N'',N''',N'''-hexamethyltriethylenetetramine, bis(dimethylaminoethyl)ether, 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-S-triazine, 2,4,6-tris(dimethylaminomethyl)phenol, 2,4-bis(dimethylaminomethyl)phenol, N-dimethylaminoethyl-N'-methylpiperazine, N,N,N',N'-tetramethylhexamethylenediamine, 1,2-dimethylimidazole, 1-isobutyl-2-methylpropanol ... and alkanolamines such as N-(3-dimethylaminopropyl)-N,N-diisopropanolamine, N-(2-hydroxyethyl)-N'-methylpiperazine, N,N-dimethylaminohexanol, and 5-dimethylamino-3-methyl-1-pentanol. These urethane-forming catalysts may be used singly or in combination.

[0068] Examples of the isocyanurate catalyst include quaternary ammonium salts, alkali metal salts of carboxylic acids having 2 to 12 carbon atoms, alkali metal salts of acetylacetone, salicylaldehyde, etc., Lewis acid complex salts of amines, metal catalysts, etc. These isocyanurate catalysts may be used alone or in combination of two or more.

[0069] The amount (content) of the catalyst may be 0.1 to 20 parts by mass based on 100 parts by mass of the total amount of the polyol and polyisocyanate.

[0070] [Foam stabilizer] As the foam stabilizer, a foam stabilizer known in the art (for example, a foam stabilizer for forming rigid polyurethane foam) can be used. The foam stabilizer is, for example, a surfactant, and may be a nonionic surfactant such as an organic silicone surfactant. One type of foam stabilizer may be used alone, or multiple types may be used in combination.

[0071] Commercially available foam stabilizers can also be used. Examples of commercially available products include L5420, L5340, L6188, L6877, L6889, L6900, L6866, L6643, and L6978 manufactured by Momentive Corporation; B8040, B8155, B8239, B8244, B8330, B8443, B8450, B8460, B8462, B8465, B8466, B8467, B8481, B8484, B8485, B8486, B8496, B8870, and B8871 manufactured by Evonik; SZ-1328, SZ-1642, SZ-1677, and SH-193 manufactured by Dow-Toray; and DC-193 and DC5598 manufactured by Air Products Co., Ltd.

[0072] The amount of the foam stabilizer may be 0.1 to 5.0 parts by mass based on 100 parts by mass of the total amount of the polyol and polyisocyanate.

[0073] [Blowing Agent] The blowing agent is, for example, water. Water reacts with isocyanate groups to generate carbon dioxide gas, which causes foaming. In addition to water, which is a chemical blowing agent, a physical blowing agent can also be used as the blowing agent. Conventionally known physical blowing agents such as hydrocarbon compounds, HFCs, HFOs, and HCFOs can be used as the blowing agent. These physical blowing agents may be used alone or in combination of two or more. From the viewpoint of easily reducing the global warming potential of the blowing agent itself and easily obtaining high thermal insulation performance (initial and long-term thermal insulation), it is particularly preferable to use at least one selected from the group consisting of HFOs and HCFOs in combination with water.

[0074] The amount of the chemical foaming agent may be 0.1 to 10 parts by mass based on 100 parts by mass of the total amount of the polyol and polyisocyanate, and the amount of the physical foaming agent may be 1 to 80 parts by mass based on 100 parts by mass of the total amount of the polyol and polyisocyanate.

[0075] [Flame Retardant] Known flame retardants can be used as the flame retardant. Specific examples of the flame retardant include phosphate esters such as tris(chloropropyl)phosphate, and organophosphazenes such as methoxyphenoxycyclophosphazene.

[0076] The blending amount (content) of the flame retardant may be 0 to 100 parts by mass based on 100 parts by mass of the total amount of the polyol and polyisocyanate.

[0077] Composition A may contain the reaction product A. The content of reaction product A may be 0.1 to 20% by mass, based on the total mass of composition A. When the content of reaction product A is 0.1% by mass or more, the increase in thermal conductivity of the polyurethane foam over time tends to be more suppressed, while when the content is 20% by mass or less, the increase in thermal conductivity of the polyurethane foam over time tends to be suppressed without impairing the mechanical properties of the polyurethane foam. From the same perspective, the content of reaction product A may be 0.5% by mass or more or 1% by mass or more, based on the total mass of composition A, and may be 15% by mass or less or 10% by mass or less. In one embodiment, the content of reaction product A based on the total amount of polyol, polyisocyanate, and reaction product A may be within the above range (e.g., 0.1 to 20% by mass).

[0078] Composition A may be a one-component composition or a multi-component composition consisting of two or more components. The multi-component composition may be, for example, a two-component composition comprising a first component containing a polyol (e.g., a polyol composition) and a second component containing a polyisocyanate (e.g., a polyisocyanate composition). The specific aromatic compounds (aromatic compound A and aromatic compound B) may be contained in at least one of the first and second components, or may be contained in a component different from the first and second components. That is, the multi-component composition may also comprise a third component containing the specific aromatic compounds (aromatic compound A and aromatic compound B) in addition to the first and second components.

[0079] Among the above examples, when the specific aromatic compounds (aromatic compound A and aromatic compound B) are contained in the polyol composition, the aromatic compounds tend to be easily dispersed uniformly in composition A. Therefore, composition A is preferably a one-component composition or a multi-component composition comprising a first component containing a polyol and at least one aromatic compound selected from the group consisting of aromatic compound A and aromatic compound B, and a second component containing a polyisocyanate.

[0080] The isocyanate index of composition A may be 100 to 400. Here, the isocyanate index (NCO index) means the percentage of the number of moles of all isocyanate groups (NCO groups) in the isocyanate group-containing compounds relative to the number of moles of all active hydrogen groups in the active hydrogen group-containing compounds contained in composition A (NCO groups / active hydrogen groups × 100). The active hydrogen group-containing compounds include not only polyols but also water. The isocyanate index (NCO index) may be 150 to 300 or 180 to 250.

[0081] Composition A described above can be used to form a polyurethane foam in which the increase in thermal conductivity over time is suppressed. Specifically, for example, a polyurethane foam can be formed by reacting a polyol and a polyisocyanate in composition A, and then foaming and curing composition A. When composition A is a multi-component composition, a polyurethane foam can be formed by mixing the liquids that make up composition A (e.g., a first liquid containing a polyol and a second liquid containing a polyisocyanate) and reacting (foaming and curing) them. The reaction (foaming and curing) can be carried out by a conventionally known method, for example, by heating in a mold.

[0082] Composition A is suitable for use as a material for heat insulating materials (polyurethane foams for heat insulating materials). Composition A can be used to form either flexible polyurethane foams (e.g., polyurethane foams having a 10% deformation compressive stress of less than 20 kPa measured in accordance with JIS K7220) or rigid polyurethane foams (e.g., polyurethane foams having a 10% deformation compressive stress of 20 kPa or more measured in accordance with JIS K7220), but is particularly suitable for use in forming rigid polyurethane foams.

[0083] <Polyurethane Foam> Another embodiment of the present disclosure is a polyurethane foam (hereinafter referred to as "polyurethane foam A") formed from the composition A described above.

[0084] The polyurethane foam A may be a polyurethane foam that contains a polyurethane resin that is a reaction product of the above-mentioned polyol and polyisocyanate, and at least one aromatic compound selected from the group consisting of aromatic compound A and aromatic compound B, and may also contain other components that can be contained in the above-mentioned composition A (catalyst, flame retardant, blowing agent, foam stabilizer, plasticizer, colorant, etc.).

[0085] The content of aromatic compound A may be 0.1 to 20 parts by mass per 100 parts by mass of polyurethane resin. When the content of aromatic compound A is 0.1 part by mass or more, there is a tendency that the increase in thermal conductivity of the polyurethane foam over time can be further suppressed, and when the content is 20 parts by mass or less, there is a tendency that the increase in thermal conductivity of the polyurethane foam over time can be suppressed without impairing the mechanical properties of the polyurethane foam. From the same viewpoint, the content of aromatic compound A may be 0.5 parts by mass or more, or 1 part by mass or more, and may be 15 parts by mass or less, or 10 parts by mass or less, per 100 parts by mass of polyurethane resin.

[0086] The content of aromatic compound B may be 0.1 to 20 parts by mass per 100 parts by mass of polyurethane resin. When the content of aromatic compound B is 0.1 part by mass or more, there is a tendency that the increase in thermal conductivity of the polyurethane foam over time can be further suppressed, and when the content is 20 parts by mass or less, there is a tendency that the increase in thermal conductivity of the polyurethane foam over time can be suppressed without impairing the mechanical properties of the polyurethane foam. From the same viewpoint, the content of aromatic compound B may be 0.5 parts by mass or more, or 1 part by mass or more, and may be 15 parts by mass or less, or 10 parts by mass or less, per 100 parts by mass of polyurethane resin.

[0087] The total content of aromatic compound A and aromatic compound B may be 0.1 to 20 parts by mass per 100 parts by mass of polyurethane resin. When the content of aromatic compound A and aromatic compound B is 0.1 part by mass or more, there is a tendency that the increase in thermal conductivity of the polyurethane foam over time can be further suppressed, and when it is 20 parts by mass or less, there is a tendency that the increase in thermal conductivity of the polyurethane foam over time can be suppressed without impairing the mechanical properties of the polyurethane foam. From the same viewpoint, the total content of aromatic compound A and aromatic compound B may be 0.5 parts by mass or more or 1 part by mass or more, and may be 15 parts by mass or less or 10 parts by mass or less, per 100 parts by mass of polyurethane resin.

[0088] Polyurethane foams are suitably used as heat insulating materials for, for example, roofs and walls of buildings, underground structures, bridge decks, water tanks, tanks, the inside of housings such as refrigerators, and the like.

[0089] The present disclosure will be described in more detail below using examples and comparative examples, but the present disclosure is not limited to the following examples.

[0090] Details of the materials used in this example are shown below. Polyol a: Maximol RFK-505 (manufactured by Air Water Performance Chemicals, Inc., phthalic acid-based polyester polyol, hydroxyl value 250 mg KOH / g) Polyol b: Maximol RFK-556 (manufactured by Air Water Performance Chemicals, Inc., phthalic acid-based polyester polyol, hydroxyl value 250 mg KOH / g) Additive A-1: ​​Ethyl carbanilate (manufactured by Tokyo Chemical Industry Co., Ltd., solid at 23°C, purity 99%) Additive A-2: Methyl carbanilate (manufactured by Tokyo Chemical Industry Co., Ltd., solid at 23°C, purity 98%) Additive A-3: Aromatic compound synthesized in Synthesis Example 1 below (solid at 23°C) Additive A-4: Aromatic compound synthesized in Synthesis Example 2 below (solid at 23°C) Additive A-5: Aromatic compound synthesized in Synthesis Example 3 below (solid at 23°C) Additive A-6: Aromatic compound synthesized in Synthesis Example 4 below (solid at 23°C) Additive B-1: Ethyl N-methylcarbamate (manufactured by Tokyo Chemical Industry Co., Ltd., liquid at 23°C, purity 98%) Additive B-2: Aromatic compound synthesized in Synthesis Example 5 below (viscous liquid at 23°C) Additive B-3: Aromatic compound synthesized in Synthesis Example 6 below (solid at 23°C) Additive B-4: Aromatic compound synthesized in Synthesis Example 7 below (viscous liquid at 23°C) Additive B-5: Aromatic compound synthesized in Synthesis Example 8 below (solid at 23°C) Additive B-6: Aromatic compound synthesized in Synthesis Example 9 below (solid at 23°C) Additive B-7: Aromatic compound synthesized in Synthesis Example 10 below (viscous liquid at 23°C) Foam stabilizer: VORASURF SH-193 fluid (manufactured by Dow-Toray Industries, Inc.) Urethane catalyst: DM70 (manufactured by Tosoh Corporation, imidazole-based catalyst) Trimerization catalyst: TOYOCAT TRX (manufactured by Tosoh Corporation, quaternary ammonium salt)

[0091] Synthesis Example 1 300 ml of methanol that had been dehydrated in advance with molecular sieves was placed in a 500 ml separable flask. Next, the methanol was cooled in an ice bath while stirring at 300 rpm, and 50 g of polyisocyanate (Millionate MR-200, polymeric MDI manufactured by Tosoh Corporation, NCO content 31% by mass, dinuclear content 41%) was placed therein. Next, the reaction solution was stirred for 10 minutes while cooling with ice, and then further stirred for 30 minutes at room temperature. Next, a sample of the reaction solution was taken and FT-IR was measured, and it was found that a peak of about 2250 cm originating from the isocyanate group of the polymeric MDI was observed. ―１ It was confirmed that the peak of [alpha] completely disappeared. Next, after distilling off the methanol under reduced pressure, the resulting pale yellow solid was ground in a mortar to form a powder, and further dried overnight in a vacuum dryer at 80°C. This yielded Additive A-3 in which the isocyanate group of the polymeric MDI was capped with a urethane bond formed by reaction with the hydroxyl group of methanol.

[0092] Synthesis Example 2 242.6 g of Millionate MR-200 was placed in a 500 ml separable flask. Next, while stirring the polyisocyanate at 150 rpm, 57.4 g of ethanol that had been previously dehydrated with a molecular sieve was added in several portions while appropriately cooling the reaction solution so that the temperature did not exceed 70°C. After the heat generation subsided, the reaction solution was further stirred for 3 hours while adjusting the temperature to 70 to 80°C, and then sampled and measured by FT-IR. －１ It was confirmed that the peak of 2000 ppm had disappeared. This gave Additive A-4 in which the isocyanate group of the polymeric MDI was capped with a urethane bond formed by reaction with the hydroxyl group of ethanol.

[0093] Synthesis Example 3 Additive A-5 was obtained in which the isocyanate group of polymeric MDI was capped with a urethane bond formed by reaction with the hydroxyl group of 2-propanol in the same manner as in Synthesis Example 2, except that the amount of Millionate MR-200 charged was changed to 207.8 g and 92.2 g of 2-propanol was used instead of ethanol.

[0094] Synthesis Example 4 Additive A-6 in which the isocyanate groups of TDI were capped with urethane bonds formed by reaction between the hydroxyl groups of ethanol and the isocyanate groups of TDI was obtained in the same manner as in Synthesis Example 1, except that tolylene diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd., a mixture of approximately 80% by mass of 2,4-tolylene diisocyanate and approximately 20% by mass of 2,6-tolylene diisocyanate; hereinafter referred to as "TDI") was used instead of Millionate MR-200 and ethanol was used instead of methanol.

[0095] Synthesis Example 5 Additive B-2 in which the isocyanate group of phenyl isocyanate was reacted with the hydroxyl group of 2-ethylhexanol to form a urethane bond was obtained in the same manner as in Synthesis Example 2, except that 143.3 g of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of Millinate MR-200 and 156.7 g of 2-ethylhexanol was used instead of ethanol.

[0096] Synthesis Example 6 Additive B-3 in which the isocyanate group of polymeric MDI was capped with a urethane bond formed by the reaction between the isocyanate group and the hydroxyl group of 1-butanol was obtained in the same manner as in Synthesis Example 2, except that the amount of Millionate MR-200 charged was changed to 194 g and 106 g of 1-butanol was used instead of ethanol.

[0097] Synthesis Example 7 Additive B-4 was obtained in which the isocyanate group of monomeric MDI was reacted with the hydroxyl group of 2-ethylhexanol to form a urethane bond, and in which the isocyanate group of monomeric MDI was capped with a urethane bond.

[0098] Synthesis Example 8 Additive B-5 was obtained in which the isocyanate group of TDI was reacted with the hydroxyl group of 2-chloroethanol to form a urethane bond, and in which the isocyanate group was capped with a urethane bond, in the same manner as in Synthesis Example 2, except that 155.9 g of TDI was used instead of Millionate MR-200 and 144.1 g of 2-chloroethanol was used instead of ethanol.

[0099] Synthesis Example 9 Additive B-6 was obtained in which the isocyanate group of TDI was reacted with the hydroxyl group of 1-butanol to form a urethane bond, and the isocyanate group of TDI was capped with a urethane bond, in the same manner as in Synthesis Example 2, except that 162.1 g of TDI was used instead of Millionate MR-200 and 137.9 g of 1-butanol was used instead of ethanol.

[0100] Synthesis Example 10 Additive B-7 in which the isocyanate group of TDI was reacted with the hydroxyl group of 2-ethylhexanol to form a urethane bond was obtained in the same manner as in Synthesis Example 2, except that 120.2 g of TDI was used instead of Millionate MR-200 and 179.8 g of 2-ethylhexanol was used instead of ethanol.

[0101] Preparation Example 1 Polyol a and polyol b were charged into a 300 mL separable flask, followed by addition of additive A-1. The temperature in the system was adjusted to 80°C, and the mixture was stirred at 300 rpm for 30 minutes. This resulted in a mixed liquid in which additive A-1 was dissolved in polyol (mixed liquid of polyol a and polyol b). Next, the temperature of the resulting mixed liquid was cooled to 30°C or below, and then a foam stabilizer, a urethane catalyst, a trimerization catalyst, and water were added to the mixed liquid, and the mixture was stirred at 300 rpm for 5 minutes while maintaining the liquid temperature at 15°C to 30°C. This resulted in polyol composition (1). The blending amounts of each component were as shown in Table 1. The blending amounts shown in Table 1 are in parts by mass.

[0102] <Preparation Example 2> A polyol composition (2) was obtained in the same manner as in Preparation Example 1, except that Additive A-2 was used instead of Additive A-1 and the blending amounts of each component were changed as shown in Table 1.

[0103] Preparation Example 3: Polyol a, polyol b, a foam stabilizer, a urethane catalyst, a trimerization catalyst, and water were added to a 300 mL separable flask and stirred at 300 rpm for 5 minutes while maintaining the liquid temperature at 15°C to 30°C. This yielded polyol composition (3). The blending amounts of each component are as shown in Table 1.

[0104] Preparation Example 4 Polyol a, polyol b, additive B-1, foam stabilizer, urethanization catalyst, trimerization catalyst, and water were added to a 300 mL separable flask and stirred at 300 rpm for 5 minutes while maintaining the liquid temperature at 15°C to 30°C. This yielded polyol composition (4). The blending amounts of each component are as shown in Table 1.

[0105] <Preparation Examples 5 to 13> Polyol compositions (5) to (14) were obtained in the same manner as in Preparation Example 1, except that Additives A-3 to A-6 or B-2 to B-7 were used instead of Additive A-1, and the blending amounts of each component were changed as shown in Table 1.

[0106]

[0107] Example 1 First, an aluminum mold equipped with a lid (mold inner dimensions: height 250 mm, width 250 mm, thickness 50 mm) was temperature-controlled in a 60°C thermostatic chamber. Next, the polyol composition (1) obtained in Preparation Example 1 and the physical foaming agent HFO-1233zd (Solstice LBA, manufactured by Honeywell) were mixed in the mass ratio shown in Table 2. Next, the resulting mixture was temperature-controlled to 20°C and poured into a 500 mL polypropylene cup. To this was added polyisocyanate (Millionate MR-200, Polymeric MDI manufactured by Tosoh Corporation, NCO content 31% by mass) separately temperature-controlled to 20°C, and the mixture was mixed at 6000 rpm for 3 seconds using a lab mixer. At this time, the amount of polyisocyanate added was adjusted so that the isocyanate index was 200, and the content of additive A-1 based on the total amount of the blended components was 5.0% by mass. Next, approximately 133 g (133 ± 2 g) of the resulting mixture (polyurethane foam-forming composition) was poured into the mold, immediately covered, and heated in a 60°C thermostatic chamber for 20 minutes to react, foam, and cure. This resulted in a rectangular parallelepiped polyurethane foam (rigid polyurethane foam). The resulting polyurethane foam was immediately removed from the mold after the reaction was completed and used for density and core density measurements and thermal conductivity evaluation.

[0108] The mass and dimensions of the polyurethane foam immediately after demolding were measured, and the foam density of the polyurethane foam was calculated in accordance with JIS A9521. Next, all six skin layers were immediately cut off to cut out a core panel from the center of the polyurethane foam, and the mass and dimensions of the core panel were measured to calculate the core density. The results are shown in Table 2. The dimensions of the core panel were 200 mm x 200 mm x 14 mm.

[0109] Examples 2 to 6 and Comparative Examples 1 to 8 Polyurethane foams of Examples 2 to 6 and Comparative Examples 1 to 8 were obtained in the same manner as in Example 1, except that polyol compositions (2) to (14) were used instead of polyol composition (1) in the blending ratios shown in Table 2 or Table 3. The content of each additive (A-2 to A-6 and B-1 to B-7) based on the total amount of the blended components in the polyurethane foam-forming compositions of Examples 2 to 6 and Comparative Examples 2 to 8 was all 5.0 mass%.

[0110] <Evaluation> The amount of change in heat insulating performance over time was evaluated by measuring the thermal conductivity of the polyurethane foams obtained in Examples 1 to 6 and Comparative Examples 1 to 8 over time. Specifically, the thermal conductivity λ (initial value) of the core panel immediately after cutting and the thermal conductivity λ of the core panel after a storage test were measured at an average temperature of 23°C using an Auto λHC-074 / 314 manufactured by Eiko Seiki Co., Ltd., according to the heat flow meter method specified in JIS A1412. The storage test was carried out by storing the core panel after initial value measurement in a constant temperature and humidity chamber at 23°C / 50% RH for 28 days.

[0111] This test was an accelerated test based on the concept of scaling coefficients as specified in JIS A1486, and aging the 14 mm thick core panel for 28 days corresponds to aging a 50 mm thick core panel for approximately one year. The results are shown in Tables 2 and 3. Note that Comparative Example 6 was marked "N / A" because it could not be evaluated due to foam shrinkage.

[0112]

[0113]

[0114] Content C in Tables 2 and 3 Ａis the content of additive A (a compound represented by formula (1) or formula (2)) in the polyurethane foam relative to 100 parts by mass of the polyurethane resin. The amount of polyurethane resin in the polyurethane foam was determined by subtracting the "mass of carbon dioxide gas generated during the reaction between water and polyisocyanate" from the total blend mass of the polyols (polyol a and polyol b), polyisocyanate, and water.

[0115] It was confirmed that in Examples 1 to 6 in which Additive A was used, the increase in thermal conductivity of the polyurethane foam over time was suppressed.

Claims

1. A polyurethane foam-forming composition comprising a polyol, a polyisocyanate, and at least one aromatic compound selected from the group consisting of compounds represented by the following formula (1) and compounds represented by the following formula (2): [In formula (1), R １ represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms; R ２ represents a hydrogen atom or a methyl group, L represents a single bond or a methylene group, and n represents 1 or 2. １ When there are a plurality of R, they may be the same or different, and when there are a plurality of L, they may be the same or different. [In formula (2), R １ is R in the formula (1). １ and m represents an integer of 0 or 1 or more. １ may be the same or different.

2. The polyurethane foam-forming composition according to claim 1, comprising a reaction product of at least one isocyanate selected from the group consisting of phenyl isocyanate, tolylene diisocyanate, diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate with an aliphatic monoalcohol having 1 to 3 carbon atoms.

3. The polyurethane foam-forming composition of claim 1, wherein said polyol comprises an aromatic polyester polyol.

4. The polyurethane foam-forming composition according to claim 1, further comprising at least one member selected from the group consisting of a catalyst, a foam stabilizer and a blowing agent.

5. An additive for polyurethane foams, comprising at least one aromatic compound selected from the group consisting of compounds represented by the following formula (1) and compounds represented by the following formula (2): [In formula (1), R １ represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms; R ２ represents a hydrogen atom or a methyl group, L represents a single bond or a methylene group, and n represents 1 or 2. １ When a plurality of are present, they may be the same or different, and when a plurality of L are present, they may be the same or different. [In formula (2), R １ is R in the formula (1). １ and m represents an integer of 0 or 1 or more. １ may be the same or different.

6. The polyurethane foam additive according to claim 5, which comprises a reaction product of at least one isocyanate selected from the group consisting of phenyl isocyanate, tolylene diisocyanate, diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate with an aliphatic monoalcohol having 1 to 3 carbon atoms.

7. The polyurethane foam additive according to claim 5 or 6, which is a thermal conductivity modifier.

8. A polyurethane foam formed from the polyurethane foam-forming composition according to any one of claims 1 to 4.

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