Raw material composition for rigid isocyanurate foam, rigid isocyanurate foam, and sound-absorbing material

Abstract

The present invention provides a raw material composition suitable for producing rigid isocyanurate foams that exhibit both excellent energy absorption and sound absorption properties, while also exhibiting excellent foam moldability, appearance, and breathability. The raw material composition for rigid isocyanurate foams of the present invention contains a polyol composition and a polyisocyanate. The polyol composition includes: a tri- or higher functional polyether polyol (C) having a hydroxyl value of 300 mgKOH / g or more; a polyether polyol (A) different from the polyether polyol (C) and having an ethylene oxide content of 50 mass% or more, based on the total amount of alkylene oxide in the polyether polyol (A); and a polyether polyol (B) different from the polyether polyol (C) and having an ethylene oxide content of 10 mass% or less, based on the total amount of alkylene oxide in the polyether polyol (B). The raw material composition has an isocyanate index of 105 or more and 400 or less. The content of component (A) is 30 parts by mass or more and 50 parts by mass or less, and the content of component (C) is 5 parts by mass or more and 35 parts by mass or less, based on 100 parts by mass of the total amount of the raw material composition excluding the polyisocyanate.

Description

[Technical Field]

[0001] The present invention relates to a raw material composition for rigid isocyanurate foam, a method for producing rigid isocyanurate foam, a rigid isocyanurate foam, and a sound-absorbing material containing the rigid isocyanurate foam. [Background technology]

[0002] Rigid isocyanurate foam is a type of resin foam obtained by the reaction of polyol and polyisocyanate, and is known to be a lightweight material with excellent mechanical properties. Rigid isocyanurate foams with these characteristics are highly useful in a variety of fields, including automobiles, construction, and civil engineering. Rigid isocyanurate foams have been actively improved from various perspectives to further enhance their functionality.

[0003] For example, Patent Document 1 discloses a rigid polyurethane foam consisting of three layers, a surface high-density layer, an internal low-density layer, and a surface high-density layer, in order to improve impact absorption and sound absorption. Patent Document 2 discloses a sound-absorbing impact absorber consisting of a rigid polyisocyanurate foam composed of a specific polyol component and a specific polyisocyanate component. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-272806 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-47338 Summary of the Invention [Problem to be solved by the invention]

[0005] However, Patent Document 1 discloses that rigid polyurethane foam has a compressive stress of 300 to 700 N at 10 to 60% strain. Assuming that the stress forms a curve that increases with displacement, rigid polyurethane foam is not considered to have sufficient energy absorption performance. The polyurethane foam disclosed in Patent Document 2 lacks cell stability within the foam, and does not necessarily achieve both sound absorption performance and energy absorption performance, leaving room for improvement.

[0006] In particular, there is a trade-off between the impact absorption performance (energy absorption performance) and the sound absorption performance of rigid isocyanurate foams, and it is not easy to improve both performances. However, both energy absorption performance and sound absorption performance are required in many applications, and from this perspective, there is a strong demand for rigid isocyanurate foams that are excellent in energy absorption performance and sound absorption performance.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a raw material composition suitable for producing a rigid isocyanurate foam that exhibits excellent foam moldability, appearance, and breathability while also exhibiting excellent energy absorption performance and sound absorption performance, and to provide a rigid isocyanurate foam and a sound-absorbing material. [Means for solving the problem]

[0008] As a result of extensive research to achieve the above object, the present inventors have found that the object can be achieved by using a specific polyol composition and a specific polyisocyanate as essential components, and have thus completed the present invention.

[0009] Specifically, the present invention includes, for example, the subject matter described in the following items:

[0010] Item 1 A raw material composition for a rigid isocyanurate foam, the raw material composition comprising a polyol composition and a polyisocyanate, The polyol composition is a polyether polyol (A) having an ethylene oxide content of 50% by mass or more, based on the total amount of alkylene oxides in the polyether polyol (A); a polyether polyol (B) having an ethylene oxide content of 10% by weight or less, based on the total amount of alkylene oxide in the polyether polyol (B); and Contains a tri- or higher functional polyether polyol (C) having a hydroxyl value of 300 mgKOH / g or more, where: The content of component (A) is 30 parts by mass or more and 50 parts by mass or less, and the content of component (C) is 5 parts by mass or more and 35 parts by mass or less, relative to 100 parts by mass of the total amount of the raw material composition excluding polyisocyanate; and A composition, wherein the raw material composition has an isocyanate index of 105 or greater and 400 or less.

[0011] Item 2 Item 2. The raw material composition according to item 1, wherein the content of component (B) is 10 parts by mass or more and 15 parts by mass or less, based on 100 parts by mass of the total amount of the raw material composition excluding the polyisocyanate.

[0012] Item 3 Item 3. A method for producing a rigid isocyanurate foam, comprising a step of reacting the raw material composition according to Item 1 or 2.

[0013] Item 4 A rigid isocyanurate foam obtained by reacting the raw material composition according to item 1 or 2.

[0014] Item 5 A sound-absorbing material comprising the rigid isocyanurate foam of item 4. [Effects of the Invention]

[0015] The raw material composition for rigid isocyanurate foam of the present invention is suitable as a raw material for producing rigid isocyanurate foam that exhibits excellent foam moldability, appearance, and breathability, while also exhibiting excellent energy absorption performance and sound absorption performance. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described in detail. In this specification, the terms "comprise" and "include" encompass the concepts of "contain," "consist essentially of," and "consist of."

[0017] 1.Raw material composition for rigid isocyanurate foam The raw material composition for rigid isocyanurate foams of the present invention contains a polyol composition and a polyisocyanate. In this specification, the raw material composition for rigid isocyanurate foams of the present invention will be simply referred to as the "raw material composition of the present invention."

[0018] In the raw material composition of the present invention, the polyol composition comprises: a tri- or higher functional polyether polyol (C) having a hydroxyl value of 300 mgKOH / g or more; a polyether polyol (A) different from the polyol (C) and having an ethylene oxide content of 50 mass% or more based on the total amount of alkylene oxide in the polyether polyol (A); and a polyether polyol (B) different from the polyol (C) and having an ethylene oxide content of 10 mass% or less based on the total amount of alkylene oxide in the polyether polyol (B).

[0019] In the raw material composition of the present invention, the content of component (A) is 30 parts by mass or more and 50 parts by mass or less, and the content of component (C) is 5 parts by mass or more and 35 parts by mass or less, relative to 100 parts by mass of the total amount of the raw material composition excluding polyisocyanate. The raw material composition of the present invention has an isocyanate index of 105 or more and 400 or less. "The total amount of the raw material composition excluding polyisocyanate" means the total amount of all components contained in the raw material composition of the present invention excluding polyisocyanate.

[0020] Due to the polyol composition and polyisocyanate, the raw material composition of the present invention can produce a rigid isocyanurate foam that is excellent in both energy absorption performance and sound absorption performance while exhibiting excellent foam moldability, appearance, and breathability. Specifically, the raw material composition of the present invention is suitable as a raw material for producing a rigid isocyanurate foam that is excellent in both energy absorption performance and sound absorption performance.

[0021] Polyol Composition As described above, the polyol composition includes a trifunctional or higher polyether polyol (C) having a hydroxyl value of 300 mg KOH / g or more, a polyether polyol (A) having an ethylene oxide content of 50 mass% or more based on the total amount of alkylene oxide in the polyether polyol (A) and different from the polyol (C), and a polyether polyol (B) having an ethylene oxide content of 10 mass% or less based on the total amount of alkylene oxide in the polyether polyol (B) and different from the polyol (C). In this specification, these components are simply referred to as "component (C)," "component (A)," and "component (B)," respectively. The ethylene oxide content, in a more precise sense, refers to the content of structural units derived from ethylene oxide based on the total content of structural units derived from alkylene oxide, and also refers to the content of structural units formed by polymerization of ethylene oxide.

[0022] Component (A) is a polyether polyol compound having an ethylene oxide unit content of 50% by mass or more, based on the total amount of alkylene oxide in polyether polyol (A). Component (A) preferably has an ethylene oxide unit content of 60% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or less, based on the total amount of alkylene oxide in polyether polyol (A). In the context of the present invention, the content of a specific alkylene oxide in a specific polyol should be understood based on the total amount of alkylene oxide in said specific polyol, unless otherwise specified.

[0023] Component (A) may contain one or more additional structural units other than ethylene oxide units, as long as component (A) has an ethylene oxide unit content of 50% by mass or more based on the total amount of alkylene oxide in polyether polyol (A). The additional structural units may be selected from a wide range of structural units contained in conventional rigid isocyanurate foams. Examples include structural units derived from various cyclic ethers such as alkylene oxides having three or more carbon atoms and styrene oxide. The cyclic ether may be, for example, the cyclic ethers described below, a specific example of which is propylene oxide units. For example, component (A) may be a polyether polyol compound containing ethylene oxide units and propylene oxide units. Component (A) may also contain structural units derived from polyhydric alcohols, as described below.

[0024] Component (A) preferably has an average active hydrogen number (f) of 2 or more, more preferably 3 or more, and more preferably 5 or less. An example of the active hydrogen of component (A) is a hydroxyl group.

[0025] In this specification, the average number of active hydrogen atoms refers to the number of active hydrogen atoms per molecule, particularly the number of hydroxyl groups per molecule. The average number of active hydrogen atoms can be controlled by the number of active hydrogen atoms of the initiator used for synthesis. The average number of active hydrogen atoms (f) can be calculated from the hydroxyl value (OHV) and number average molecular weight (Mn) of the polyol using the following formula:

[0026]

number

[0027] Component (A) preferably has a hydroxyl number of less than 300 mg KOH / g, more preferably 7-87 mg KOH / g, and most preferably 17-57 mg KOH / g.

[0028] In this specification, the hydroxyl value refers to the amount of potassium hydroxide in milligrams required to neutralize the free hydroxyl groups (in 1 g of sample) that have been completely acetylated with acetic anhydride, and means the value measured in accordance with JIS K1557 (2007). Specifically, the hydroxyl value is determined as follows: The hydroxyl groups in the sample are acetylated with acetic anhydride, and the acetic anhydride that has not been involved in the acetylation is titrated with an ethanolic solution of potassium hydroxide. The result is applied to the following equation:

[0029]

number

[0030] The mass average molecular weight (Mw) of component (A) is not particularly limited and can be, for example, in the same range as that of polyether polyol compounds used in the production of conventional rigid isocyanurate foams. For example, the mass average molecular weight (Mw) of component (A) is preferably 1,000 or more and 10,000 or less. The mass average molecular weight (Mw) (also referred to as "weight average molecular weight") used in this specification is one of the average molecular weights of a synthetic polymer. When the molecular weight of component i contained in the polymer is Mi, the weight fraction is wi, and the number of molecules is Ni, the mass average molecular weight ΣMiwi is calculated using the following formula:

[0031]

number

[0032] Specifically, the weight average molecular weight refers to the sum of the molecular weights of the individual components of the polymer multiplied by their weight fractions. The weight average molecular weight can be measured by GPC.

[0033] Component (A) contained in the polyol composition may be one type or two or more types, i.e., it may be composed of one type of polyether polyol or two or more different polyether polyols, and each polyether polyol of component (A) has an ethylene oxide unit content of 50 mass% or more based on the total amount of alkylene oxide in each polyether polyol of component (A).

[0034] Component (B) is a polyether polyol compound having an ethylene oxide unit content of 10% by mass or less, based on the total amount of alkylene oxide in polyether polyol (B). Component (B) preferably has an ethylene oxide unit content of 5% by mass or less, more preferably 1% by mass or less, based on the total amount of alkylene oxide in polyether polyol (B). Component (B) may have an ethylene oxide unit content of 0% by mass, i.e., component (B) may not contain ethylene oxide units.

[0035] Component (B) contains one or more additional structural units other than ethylene oxide units. The additional structural units may be selected from a wide range of structural units contained in conventional rigid isocyanurate foams. Examples include structural units derived from various cyclic ethers, such as alkylene oxides having three or more carbon atoms and styrene oxide. The cyclic ethers may be, for example, any of the wide range of cyclic ethers described below. For example, component (B) may be a polyether polyol compound containing ethylene oxide units and propylene oxide units. Component (B) may also be a polyether polyol compound that does not contain ethylene oxide units but contains propylene oxide units. Component (B) may also contain structural units derived from polyhydric alcohols, as described below.

[0036] Component (B) preferably has an average active hydrogen number (f) of 2 or more, more preferably 3 or more, and more preferably 5 or less. An example of the active hydrogen of component (B) is a hydroxyl group.

[0037] Component (B) preferably has a hydroxyl value of less than 300 mgKOH / g, more preferably 20 to 92 mgKOH / g, and most preferably 36 to 76 mgKOH / g. The hydroxyl value of component (B) can be determined in the same manner as the hydroxyl value of component (A) above.

[0038] The mass average molecular weight (Mw) of component (B) is not particularly limited and can be, for example, in the same range as that of polyether polyol compounds used in the production of conventional rigid isocyanurate foams. For example, the mass average molecular weight (Mw) of component (B) is preferably 1,000 or more and 10,000 or less. The mass average molecular weight of component (B) can also be measured by GPC in the same manner as for component (A).

[0039] Component (B) contained in the polyol composition may be one type or two or more types, i.e., it may be composed of one type of polyether polyol or two or more different polyether polyols, and each polyether polyol of component (B) has an ethylene oxide unit content of 10 mass % or less based on the total amount of alkylene oxide in each polyether polyol of component (B).

[0040] Component (C) is a tri- or higher functional polyether polyol compound having a hydroxyl value of 300 mg KOH / g or more. Components (A) and (B) are different from component (C) (in other words, components (A) and (B) are polyether polyol compounds having a hydroxyl value of 300 mg KOH / g or more other than tri- or higher functional polyether polyol compounds).

[0041] Component (C) is preferably a polyether polyol compound having 4 or more functionalities, and more preferably an 8 or less functional polyether polyol compound. An example of the active hydrogen of component (C) is a hydroxyl group.

[0042] From the viewpoint of facilitating the formation of a rigid isocyanurate foam excellent in both energy absorption performance and sound absorption performance, component (C) preferably has a hydroxyl value of 400 mgKOH / g or more. The upper limit of the hydroxyl value of component (C) is not particularly limited, and is, for example, preferably 800 mgKOH / g or less, more preferably 500 mgKOH / g or less. The hydroxyl value of component (C) can be determined in the same manner as the hydroxyl value of component (A) above.

[0043] The mass average molecular weight (Mw) of component (C) is not particularly limited, but is preferably, for example, from 100 to 1000. The mass average molecular weight of component (C) can be measured by GPC in the same manner as component (A).

[0044] The type of structural unit of component (C) is not particularly limited, as long as component (C) is a trifunctional or higher polyether polyol compound having a hydroxyl value of 300 mgKOH / g or more. For example, the structural unit contained in component (C) may be selected from a wide range of structural units contained in conventional rigid isocyanurate foams. Examples include structural units derived from various cyclic ethers such as alkylene oxides and styrene oxides having three or more carbon atoms. Examples of cyclic ethers include the wide range of cyclic ethers described below, and a specific example is propylene oxide units. Component (C) may also contain structural units derived from polyhydric alcohols described below.

[0045] Component (C) contained in the polyol composition may be one type or two or more types, i.e., it may be composed of one type of polyether polyol or two or more different polyether polyols, and the polyether polyol of component (C) is a tri- or higher functional polyether polyol compound having a hydroxyl value of 300 mgKOH / g or more.

[0046] The methods for producing components (A), (B), and (C) are not particularly limited, and these components can be produced by known methods, for example. Specifically, these components can be produced by polyaddition of a cyclic ether, condensation of a polyhydric alcohol, or addition polymerization of a cyclic ether and a polyhydric alcohol. The types of cyclic ether and polyhydric alcohol used as raw materials are not particularly limited, and can be appropriately selected depending on the structure of the polyether polyol compound (target substance). In particular, in the production of component (A), raw materials can be selected so that the oxyethylene unit content in component (A) is 50% by mass or more. In the production of component (B), raw materials can be selected so that the oxyethylene unit content in component (B) is 10% by mass or less.

[0047] Examples of cyclic ethers include ethylene oxide, styrene oxide, propylene oxide, tetrahydrofuran, butylene oxide, and epichlorohydrin. These cyclic ethers may be used alone or in combination of two or more. Examples of polyhydric alcohols include diol compounds such as ethanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-dihydroxycyclohexane, 1,4-dimethylolcyclohexane, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol; and tri- or higher functional polyols such as trimethylolpropane, glycerol (glycerin), and pentaerythritol. These polyhydric alcohols may be used alone or in combination. The polyhydric alcohol for preparing component (C) is preferably pentaerythritol.

[0048] Components (A), (B) and (C) may be, for example, commercially available products.

[0049] The polyol composition may contain other components as long as it contains component (A), component (B), and component (C). For example, as long as the effects of the present invention are not impaired, the polyol composition may contain one or more additional polyether polyol compounds other than component (A), component (B), and component (C), or may contain other polyol compounds such as polyester polyol, polycarbonate polyol, polyester ether polyol, polyester polycarbonate polyol, polylactone polyol, polybutadiene polyol, polymer polyol, or silicone polyol.

[0050] The polyol compound contained in the polyol composition may be only a polyether polyol compound, or may consist of component (A), component (B), and component (C).

[0051] The polyol composition may contain, in addition to components (A), (B), and (C), various additives for use in producing rigid isocyanurate foams. Note that the polyol composition does not contain a polyisocyanurate, which will be described later.

[0052] Examples of additives that can be contained in the polyol composition include a foaming agent, a catalyst, a crosslinking agent, a foam stabilizer, and an emulsifier.

[0053] The blowing agent can be of any type, and can be selected from a wide range of known blowing agents used in the production of conventional rigid isocyanurate foams. Examples of blowing agents include chemical blowing agents such as water and carboxylic acid compounds; and physical blowing agents such as halogenated hydrocarbon compounds including hydrofluoroolefins and hydrochlorofluoroolefins. The blowing agent contained in the polyol composition is preferably water. The blowing agent contained in the polyol composition can be one type or two or more types.

[0054] The content of the blowing agent is not particularly limited and may be, for example, the same content as that of a blowing agent in a known rigid isocyanurate foam, and is preferably 1 to 20 mass% based on the total mass of the polyol composition and a polyisocyanate described below.

[0055] The catalyst may be of any type, and may be selected from a wide range of known catalysts used in the production of conventional rigid isocyanurate foams. Preferably, the catalyst is, for example, a catalyst that promotes the reaction between water and isocyanate (blowing catalyst), a catalyst that promotes the reaction between polyol and isocyanate (resinification catalyst), or a catalyst that promotes the trimerization of isocyanate (i.e., the formation of isocyanurate rings) (trimerization catalyst). The polyol composition may contain one or more types of catalysts.

[0056] Examples of blowing 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'-hydroxyethylbisaminoethyl ether.

[0057] Examples of resinification catalysts include amine catalysts such as 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) Examples of suitable catalysts include amines; alkanolamine catalysts such as N,N-dimethylaminoethanol, N,N,N'-trimethylaminoethylethanolamine, N-(3-dimethylaminopropyl)-N,N-diisopropylamine, N-(2-hydroxyethyl)-N'-methylpiperazine, N,N-dimethylaminohexanol, and 5-dimethylamino-3-methyl-1-pentanol; and metal catalysts such as tin 2-ethylhexanoate, dibutyltin dilaurate, lead octoate, bismuth carboxylate, and zirconium complexes. These amine and alkanolamine catalysts may be amine carbonates synthesized by adding carbonic acid, or may be amine carboxylates synthesized by adding a carboxylic acid such as formic acid or acetic acid.

[0058] Examples of trimerization catalysts 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; metal salts of carboxylic acids such as potassium acetate, potassium 2-ethylhexanoate, and potassium octoate; and quaternary ammonium salts of carboxylic acids; and onium salts of carboxylic acids.

[0059] The catalyst content in the polyol composition is not particularly limited, and may be, for example, the same as that in known rigid isocyanurate foams. The catalyst content is preferably 0.1 to 1 mass % based on the total mass of the polyol composition and the polyisocyanate described below.

[0060] The crosslinking agent can be of any type and can be selected from a wide range of known crosslinking agents used in the production of conventional rigid isocyanurate foams. Examples of crosslinking agents include polyhydric alcohols such as 1,4-butanediol, ethylene glycol, diethylene glycol, and glycerin; amines such as ethanolamine and polyethylene polyamine. The polyol composition may contain one or more crosslinking agents.

[0061] The content of the crosslinking agent is not particularly limited, and may be, for example, the same as that of a known rigid isocyanurate foam. The content of the crosslinking agent is preferably 0.5 to 5 mass% based on the total mass of the polyol composition and the polyisocyanate described below.

[0062] The foam stabilizer may be of any type, and may be selected from a wide range of known foam stabilizers. Examples of the foam stabilizer include silicone-based foam stabilizers and fluorine-containing compound-based foam stabilizers, with silicone-based foam stabilizers being preferred. The foam stabilizer may be one type, or may be a composition formed by combining two or more types of foam stabilizers.

[0063] The silicone-based foam stabilizer may be, for example, a silicone foam stabilizer containing a polyoxyalkylene-dimethylpolysiloxane copolymer as a main component. The silicone-based foam stabilizer may be a polyoxyalkylene-dimethylpolysiloxane copolymer alone, or may be this copolymer in combination with other components. Examples of the other components to be combined include polyalkylmethylsiloxane, glycol, and polyoxyalkylene compound. In another preferred embodiment, the foam stabilizer may be a composition containing two or more of the following components: a polyoxyalkylene-dimethylpolysiloxane copolymer, a polyalkylmethylsiloxane, and a polyoxyalkylene compound. This foam stabilizer is advantageous from the viewpoint of foam stability.

[0064] Examples of commercially available foam stabilizers include the following products manufactured by Momentive: L-580, L-590, L-620, L-680, L-682, L-690, SC-154, SC-155, SC-240, L-598, L-2100, L-2171, SH-210, L-2114, SE-232, L-533, L-534, L-539, M-6682B, L-626, L-627, L-3001, Examples of such compounds include L-3111, L-3415, L-3002, L-3010, L-3222, L-3416, L-3003, L-3333, L-3417, L-2171, L-3620, L-3630, L-3640, L-3170, L-3360, L-3350, L-3555, L-3167, L-3150 / L-3151, L-5309, SH-209, and L-3184 (trade names). Other examples of commercially available products include the following products (trade names) manufactured by Dow Coming Toray Co., Ltd.: SF-2964, SF-2962, SF-2969, SF-2971, SF-2902L, SF-2904, SF-2908, SF-2909, SRX-274C, SZ-1328, SZ-1329, SZ-1330, SZ-1336, SZ-1346, SZ-3601, SRX-294A, SRX-280A, SRX-294A, SRX-298, SH-190, SH-192, and SH-194.

[0065] The content of the foam stabilizer is not particularly limited, and may be, for example, the same content as that of a known rigid isocyanurate foam. The content of the foam stabilizer is preferably 0.5 to 5 mass% based on the total mass of the polyol composition and the polyisocyanate described below.

[0066] The emulsifier can be of any type, including anionic surfactants, cationic surfactants, or amphoteric surfactants. Among these, nonionic surfactants are preferred. Nonionic surfactants are surfactants that do not dissociate into ions in aqueous solution and have long-chain lipophilic atomic groups, such as hydroxyl groups (-OH), ether bonds (-O-), ester groups (-COOR), or carbamoyl groups (-CONH2), and alkyl or alkyl-substituted aryl groups, in their molecules. Specific nonionic surfactants include ethylene oxide-based nonionic surfactants, polyoxyalkyl ethers, polyoxyalkylaryl ethers, polyoxyalkylene alkyl ethers, polyoxyalkylamines, fatty acid ester-based nonionic surfactants, polyoxyalkylene fatty acid esters, polyethylene glycol dioleates, polyoxyethylene fatty acid diesters, polyglycerin fatty acid esters, polyanhydrosorbitol fatty acid esters, and polyethyleneimines.

[0067] The content of the emulsifier is not particularly limited, and may be, for example, the same content as that of a known rigid isocyanurate foam. The content of the foam stabilizer is preferably 0.5 to 10 mass% based on the total mass of the polyol composition and the polyisocyanate described below.

[0068] The polyol composition may contain various other components in addition to the blowing agent, catalyst, crosslinking agent, foam stabilizer, and emulsifier described above. Examples include additives such as anti-settling agents, cell breakers, antioxidants, UV absorbers, light stabilizers, plasticizers, flame retardants, water repellents, antibacterial agents, antifungal agents, pigments, and dyes. These additives can be selected from a wide range of additives used in the production of conventional rigid isocyanurate foams, and each additive may be used alone or in combination of two or more.

[0069] Polyisocyanate The raw material composition of the present invention contains polyisocyanate as an essential component. Polyisocyanate is a compound having two or more isocyanate groups.

[0070] The polyisocyanate can be of any type and can be selected from a wide range of, for example, aliphatic, cycloaliphatic, aromatic, or araliphatic polyisocyanates.

[0071] Examples of aromatic polyisocyanates include phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, and polymethylene polyphenyl polyisocyanate. Examples of alicyclic polyisocyanates include cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and dimethyldicyclohexylmethane diisocyanate. Examples of aliphatic polyisocyanates include methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate.

[0072] The polyisocyanate may be a modified polyisocyanate. Examples include polyisocyanates having structures such as uretdione, isocyanurate, urethane, urea, allophanate, biuret, carbodiimide, iminooxadiazinedione, oxadiazinetrione, or oxazolidone. The polyisocyanate to be used may be an isocyanate group-containing prepolymer obtained by reacting a polyol with a polyisocyanate.

[0073] The polyisocyanate contained in the raw material composition may be one type or two or more types, that is, it may be one type of polyisocyanate or two or more different types of polyisocyanates.

[0074] Raw material composition As described above, the raw material composition of the present invention contains a polyol composition and a polyisocyanate.

[0075] The raw material composition of the present invention has an isocyanate index of 105 or more and 400 or less. An isocyanate index within this range provides a raw material composition that makes it easier to produce a rigid isocyanurate foam that has excellent both energy absorption performance and sound absorption performance.

[0076] The isocyanate index is the ratio of the isocyanate groups in the polyisocyanate component to the total active hydrogen atoms that react with the isocyanate groups in the polyol composition multiplied by 100. The active hydrogen atoms that react with the isocyanate groups in the polyol composition are derived, for example, from the polyol component. When the blowing agent is, for example, a carboxylic acid or water, these blowing agents also have active hydrogens that react with the isocyanate groups.

[0077] From the viewpoint of easily producing a rigid isocyanurate foam excellent in both energy absorption performance and sound absorption performance, the isocyanate index is preferably 120 or more, more preferably 130 or more, even more preferably 140 or more, particularly preferably 180 or more; even more preferably 300 or less, more preferably 220 or less, even more preferably 200 or less, particularly preferably 190 or less.

[0078] As long as the raw material composition contains a polyol composition and a polyisocyanate, the raw material composition may contain other components. The raw material composition may be composed of a polyol composition and a polyisocyanate. In the present invention, all components other than the polyisocyanate are considered to constitute the polyol composition, and therefore the raw material composition of the present invention preferably consists of a polyol composition and a polyisocyanate.

[0079] In the raw material composition of the present invention, the contents of component (A) and component (C) are determined as described above as follows. Specifically, the content of component (A) is 30 to 50 parts by mass, and the content of component (C) is 5 to 35 parts by mass, relative to 100 parts by mass of the total amount of the raw material composition excluding polyisocyanate. A content of component (A) of less than 30 parts by mass in the raw material composition may reduce the breathability of the rigid isocyanurate foam, making it impossible to achieve the desired sound absorption coefficient. A content of component (A) of more than 50 parts by mass makes it difficult to adjust the reactivity during the production of the rigid isocyanurate, making it impossible to achieve the desired impact absorption performance. A content of component (C) of less than 5 parts by mass in the raw material composition may make it impossible to form a rigid isocyanurate foam. A content of component (C) of more than 35 parts by mass in the raw material composition may reduce the breathability of the rigid isocyanurate foam, making it impossible to achieve the desired sound absorption coefficient.

[0080] In the raw material composition, the "total amount of the raw material composition excluding the polyisocyanate" refers to the total amount of all components contained in the raw material composition excluding the polyisocyanate. Therefore, when the raw material composition consists of a polyol composition and a polyisocyanate, the "total amount of the raw material composition excluding the polyisocyanate" is synonymous with the total amount of the polyol composition. In the present application, the content of the components of the polyol composition in parts by mass is understood to be per 100 parts by mass of the total amount of the raw material composition excluding the polyisocyanate, unless otherwise specified.

[0081] The content of component (A) is preferably 32 parts by mass or more, preferably 48 parts by mass or less, more preferably 46 parts by mass or less, even more preferably 45 parts by mass or less, and particularly preferably 40 parts by mass or less, per 100 parts by mass of the total amount of the raw material composition excluding the polyisocyanate.

[0082] The content of component (C) is preferably 10 parts by mass or more, more preferably 13 parts by mass or more, even more preferably 15 parts by mass or more, and particularly preferably 20 parts by mass or more, per 100 parts by mass of the total amount of the raw material composition excluding the polyisocyanate.

[0083] The content of component (C) is preferably 34 parts by mass or less, more preferably 32 parts by mass or less, and even more preferably 30 parts by mass or less, per 100 parts by mass of the total amount of the raw material composition excluding polyisocyanate.

[0084] The content of component (B) in the raw material composition is not particularly limited. From the viewpoint of easily producing a rigid isocyanurate foam excellent in both energy absorption performance and sound absorption performance, the content of component (B) is preferably 10 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the total amount of the raw material composition excluding the polyisocyanate.

[0085] The method for preparing the raw material composition is not particularly limited. For example, the raw material composition can be prepared by mixing a polyol composition and a polyisocyanate in a predetermined ratio. The method for preparing the polyol composition is also not particularly limited. For example, the polyol composition can be obtained by mixing component (A), component (B), and component (C) with optional additives in a predetermined ratio. For example, it is preferable to mix the polyol composition and the polyisocyanate at a constant liquid temperature. In this case, the liquid temperature is preferably 25 to 35°C. This makes it easier for the viscosity and fluidity of the composition to fall within an appropriate range, improving the filling of the composition. This reduces voids in the rigid isocyanurate foam. In preparing the polyol composition, components other than the blowing agent may be added in advance and then mixed with the blowing agent.

[0086] 2. Rigid isocyanurate foam The raw material composition of the present invention can be used as a raw material for producing a rigid isocyanurate foam. Specifically, the raw material composition can be used to produce a rigid isocyanurate foam. Therefore, the rigid isocyanurate foam is a molded foam of the raw material composition.

[0087] The method for obtaining a rigid isocyanurate foam using the raw material composition is not particularly limited. For example, a wide range of known methods for producing rigid isocyanurate foams can be used in the present invention. Therefore, the rigid isocyanurate foam can be produced by foaming the raw material composition according to an appropriate method and optionally molding the foam.

[0088] The foaming method for the raw material composition is not particularly limited, and the method for use may be any known foaming technique, such as hand mixing foaming, simple foaming, continuous foaming, injection foaming, froth injection foaming, or spray foaming. The molding method for the rigid isocyanurate foam is also not particularly limited, and the method for use may be any known molding technique, such as mold molding, slab molding, laminate molding, or in-situ foam molding.

[0089] In molding a rigid isocyanurate foam, the mold surface temperature is preferably 50 to 70°C. This ensures appropriate reactivity and allows the raw material composition to be efficiently filled into the molding die. The demolding time (the time from the start of injection of the foam-producing composition to the start of mold opening for the molded article) is preferably 120 to 600 seconds, more preferably 180 to 360 seconds. Open molding allows rigid isocyanurate foam to be molded in a short time, easily improving production efficiency.

[0090] As described above, by using the raw material composition of the present invention, a rigid isocyanurate foam can be obtained, that is, the rigid isocyanurate foam is a foam of the raw material composition of the present invention.

[0091] The shape and size of the rigid isocyanurate foam are not particularly limited and can be appropriately determined depending on the application.

[0092] The rigid isocyanurate foam can have any density. The density of the rigid isocyanurate foam is, for example, preferably 20 to 200 kg / m 3 , more preferably 40 to 140 kg / m 3 The density of the rigid isocyanurate foam can be measured in accordance with JIS K7222:1999.

[0093] The air permeability of the rigid isocyanurate foam is, for example, 1 to 80 L / min, preferably 2 to 60 L / min. This makes it easier to impart excellent sound absorption performance to the rigid isocyanurate foam. The air permeability of the rigid isocyanurate foam can be measured in accordance with JIS K6400-7A (negative pressure type).

[0094] The rigid isocyanurate foam formed from the raw material composition of the present invention has excellent energy absorption properties and sound absorption properties.

[0095] Since there is a trade-off between energy absorption performance and sound absorption performance, it has been difficult to achieve both. However, rigid isocyanurate foam is formed from raw materials containing specific components, a polyol composition and a polyisocyanate, and therefore excels in both performances.

[0096] Thus, the rigid isocyanurate foam formed from the raw material composition of the present invention has a wide range of applications requiring energy absorption and sound absorption performance. For example, the rigid isocyanurate foam can be used in various fields, such as vehicles, ships, plants, thermal insulation equipment, architecture, civil engineering, furniture, and interior decoration. In particular, due to its excellent energy absorption and sound absorption performance, the rigid isocyanurate foam is suitable for automobile interior parts.

[0097] The rigid isocyanurate foam of the present invention can be widely used in areas where either energy absorption performance or sound absorption performance is required. For example, since the rigid isocyanurate foam has excellent impact absorption performance, it can be suitably used in various safety components.

[0098] 3. Sound-absorbing materials Rigid urethane foam has excellent sound-absorbing properties and can be used as a sound-absorbing material. Such a sound-absorbing material is not particularly limited as long as it contains a rigid isocyanurate foam. For example, the sound-absorbing material can be constructed in the same manner as known sound-absorbing materials. The sound-absorbing material may be formed by combining a rigid isocyanurate foam with other components, or may be formed solely from a rigid isocyanurate foam.

[0099] The sound-absorbing material of the present invention contains the rigid isocyanurate foam obtained from the raw material composition described above, and therefore has excellent energy absorption and sound absorption properties. Therefore, the sound-absorbing material of the present invention can be suitably used as an automobile interior part.

[0100] In another embodiment of the sound-absorbing material of the present invention, a sound-absorbing material can be obtained using a sound-absorbing material composition containing component (A), component (B), component (C), and a polyol composition containing a polyisocyanate. Specifically, a rigid isocyanurate foam formed by foaming and molding the sound-absorbing material composition can be used as the sound-absorbing material. Furthermore, the sound-absorbing material of this embodiment has excellent both energy absorption performance and sound absorption performance. [Example]

[0101] Example The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the embodiments of these examples.

[0102] To produce the rigid isocyanurate foams of the Examples and Comparative Examples, raw materials were appropriately selected from the raw materials (polyol compositions and polyisocyanates) shown below.

[0103] Polyol Composition The polyol composition was prepared by selecting materials from the following components (A), (B), (C), a crosslinking agent, a catalyst, a foam stabilizer, a foaming agent, and an emulsifier.

[0104] Component (A) Propylene oxide and ethylene oxide were used to perform addition polymerization on glycerin to obtain a polyether polyol (A) having an average active hydrogen number (f) of 3.0, a hydroxyl value of 37 mgKOH / g, a mass average molecular weight of approximately 4,500, and an ethylene oxide unit content of 70 mass%.

[0105] Ingredient (B) Propylene oxide was used to carry out addition polymerization with glycerin to obtain a polyether polyol (B) having an average active hydrogen number (f) of 3.0, a hydroxyl value of 56 mgKOH / g, and a mass average molecular weight of about 3,000.

[0106] Ingredients (C) Propylene oxide was used to carry out addition polymerization of pentaerythritol to obtain a polyether polyol (C) having an average active hydrogen number (f) of 4.0, a hydroxyl value of 410 mgKOH / g, and a mass average molecular weight of about 487.

[0107] Crosslinking agent Crosslinker 1: Glycerin (Kao Corporation)

[0108] catalyst Catalyst: DABCO BL-11 (manufactured by Evonik Industries AG) Catalyst: DABCO EG (manufactured by Evonik Industries AG) Catalyst 3: DABCO K-15 (manufactured by Evonik Industries AG) Catalyst 4: Potassium acetate

[0109] foaming agent ·water

[0110] foam stabilizer ·SRX-280A (manufactured by Dow Corning Toray Co., Ltd.)

[0111] emulsifier Emulsifier 1: EMALEX DEG-di-O (manufactured by Nihon Emulsion Co., Ltd.) Emulsifier 2: IONET DO-600 (Sanyo Chemical Industries, Ltd.)

[0112] Polyisocyanate Polymethylene polyphenyl polyisocyanate (isocyanate group content: 31.5% by mass)

[0113] Example 1 According to the formulation in Table 1, a raw material composition containing a polyol composition and a polyisocyanate was prepared as follows. First, 40 parts by weight of component (A), 12 parts by weight of component (B), 5 parts by weight of component (C), and additives (crosslinking agent, catalyst, foam stabilizer, and emulsifier) ​​were mixed in a mixing pot according to the formulation shown in Table 1. Next, a foaming agent was added to the mixture obtained according to the formulation shown in Table 1 to prepare a polyol composition. While maintaining this polyol composition at 30°C, a polyisocyanate was added to it in an amount to achieve the isocyanate index shown in Table 1, and the mixture was mixed with stirring. The liquid mixture was poured into a mold, foamed, and cured. Foaming was carried out using a high-pressure foam molding machine by injecting the polyol composition into the mold. In this process, the composition of the present invention was prepared by mixing the polyol mixture and the polyisocyanate to form a single composition, which was then poured into the mold. The high-pressure foam molding machine used was a Model A System 40 manufactured by Canon Inc. The mixture was poured into a mold at a discharge rate of 200-250 g / sec, a mixing pressure of 15 MPa, and an injection time of 0.5-0.8 sec to obtain a molded product (200 mm x 200 mm x 50 mm). The surface temperature was maintained at around 60°C during molding. The desired rigid isocyanurate foam was obtained by the above procedure.

[0114] Example 2-13 Rigid isocyanurate foams were obtained in the same manner as in Example 1, except that the types and amounts of raw materials were changed as shown in Table 1.

[0115] Comparative Examples 1-4 Rigid isocyanurate foams were obtained in the same manner as in Example 1, except that the types and amounts of raw materials were changed as shown in Table 1.

[0116] Evaluation method The rigid isocyanurate foams (test pieces) obtained in each of the Examples and Comparative Examples were measured for density, air permeability, sound absorption coefficient, presence or absence of free form, compressive strength, and compressive stress.

[0117] Sound absorption coefficient The sound absorption coefficient of the rigid isocyanurate foam was measured in accordance with JIS A1405-2. A sound absorption coefficient of 10% or more (preferably 15% or more) at 2000 Hz was judged as acceptable, and a sound absorption coefficient of 20% or more at 3150 Hz was judged as unacceptable.

[0118] Freeform Shaping and Appearance Separately, raw material compositions prepared in the same manner as in the Examples and Comparative Examples according to the formulations shown in Table 1 were individually added to 2L cups, foamed, and cured. Foaming was carried out using a high-pressure foaming machine by injecting each polyol composition into a mold. In this process, the composition of the present invention was prepared as a single composition by mixing the polyol mixture and polyisocyanate, and then injected into the mold. The high-pressure foaming machine used was a Model A System 40 manufactured by Canon Inc. Open injection and molding were carried out at an injection rate of 250 g / sec, a mixing pressure of 15 MPa, and an injection time of 0.4 sec to obtain free-form evaluation samples. The appearance of the obtained samples (foam rise, collapse, and shrinkage) was visually observed and evaluated based on the following criteria. A: Excellent foaming without collapse, and no shrinkage or deformation occurred. B: Collapse occurred, bubbles did not rise, and shrinkage and deformation occurred.

[0119] Compressive strength, compressive stress, and energy absorption capacity Rigid isocyanurate foam cut into small pieces measuring 50 mm x 50 mm x 50 mm was used as the measurement sample. The measurement device used was a precision universal testing machine (manufactured by MinebeaMitsumi Inc.). The measurement sample was placed flat in the center of the table of the testing machine, and then a pressure plate was placed on top of the test sample. When the load reached 1 N (initial thickness measurement load), the thickness of the sample was read to the nearest 0.1 mm, and this thickness was taken as the initial thickness. The pressure plate was then pressed against the measurement sample at a speed of 10 mm / min until the thickness reached 80% of the initial thickness, and the load at this time was taken as the compressive strength (N) of the rigid isocyanurate foam. The compressive stress was calculated using the following formula:

[0120]

number

[0121] The energy absorption performance was evaluated based on the increase in compressive stress expressed by the following formula.

[0122]

number

[0123] A compressive stress increase of 40% or less was determined to be a pass (the sample had good energy absorption capabilities).

[0124] density The density of the rigid isocyanurate foam was measured in accordance with JIS K7222:1999.

[0125] Breathable The air permeability of the rigid isocyanurate foam was measured in accordance with JIS K6400-7A (negative pressure method). Air permeability of 0.5 L / min or more was determined to be acceptable. In this measurement, the core part (50 mm x 50 mm x 25 mm) of the rigid isocyanurate foam was used as the measurement sample.

[0126] Table 1 [Table 1]

[0127] As shown in Table 1, the rigid isocyanurate foams obtained in the examples had good free-formability and appearance, and were evaluated as being excellent in foam formability, appearance, and breathability. In Comparative Example 1, physical properties could not be measured due to defects in foam formability. The rigid isocyanurate foams obtained in Comparative Examples 2 and 5 had a breathability of "0," clearly indicating a lack of desired sound absorption performance.

[0128] Furthermore, all of the rigid isocyanurate foams obtained in the examples had a sound absorption coefficient of more than 10% at 2000 Hz, demonstrating excellent sound absorption performance. The rigid isocyanurate foams obtained in the examples showed a low rate of increase in compressive stress (40% or less) when compressed 10% to 50%, a high retention rate, and excellent energy absorption performance. Therefore, it was found that rigid isocyanurate foams obtained from raw materials containing a specific polyol composition and a specific polyisocyanate have excellent both sound absorption performance and energy absorption performance.

Claims

1. A raw material composition for a rigid isocyanurate foam, the raw material composition comprising a polyol composition and a polyisocyanate, The polyol composition is (C) a tri- or higher functional polyether polyol having a hydroxyl value of 300 mg KOH / g or more; a polyether polyol (A) different from the polyol (C), having an ethylene oxide content of 50% by mass or more, based on the total amount of alkylene oxide in the polyether polyol (A); and a polyether polyol (B) different from the polyol (C), having an ethylene oxide content of 10% by mass or less, based on the total amount of alkylene oxide in the polyether polyol (B); Including, where: the content of the component (A) is 30 parts by mass or more and 50 parts by mass or less, and the content of the component (C) is 5 parts by mass or more and 35 parts by mass or less, per 100 parts by mass of the total amount of the raw material composition excluding the polyisocyanate; and The raw material composition has an isocyanate index of 105 or greater and 400 or less.

2. 2. The raw material composition according to claim 1, wherein the content of the component (B) is 10 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the total amount of the raw material composition excluding the polyisocyanate.

3. A method for producing a rigid isocyanurate foam, comprising a step of reacting the raw material composition according to claim 1 or 2.

4. A rigid isocyanurate foam obtained by reacting the raw material composition according to claim 1 or 2.

5. A sound absorbing material comprising the rigid isocyanurate foam of claim 4.

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