Polyol chemical composition

Abstract

To provide a polyol chemical composition that can be safely stored even in a high temperature environment without causing boiling or bumping.SOLUTION: Provided is a polyol composition that forms polyurethane foam by reaction with polyisocyanate, containing, along with a liquid polyol and as a foaming agent, at least a low boiling point foaming agent having a boiling point of less than 35°C, and constituted by, so that the contained amount of the low boiling point foaming agent is equal to or less than the solubility in the polyol, having the low boiling point foaming agent dissolved in the polyol.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyol liquid chemical composition, and more particularly to a polyol liquid chemical composition for polyurethane foams that can be safely stored even in a high-temperature environment. [Background technology]

[0002] Polyurethane foams have traditionally been used primarily as insulating materials, taking advantage of their excellent thermal insulation properties, adhesiveness, light weight, and other characteristics, for insulating interior and exterior building wall materials and panels, insulating metal siding and electric refrigerators, insulating and preventing condensation on the walls, ceilings, and roofs of buildings, condominiums, and cold storage warehouses, insulating infusion pipes, and also as backfill materials for filling voids that occur in civil engineering works and as reinforcing materials for civil engineering works. Such polyurethane foams are generally produced by continuously or intermittently mixing, in a mixing device, a composition A consisting of a polyol blend liquid (premix liquid) containing a polyol, a blowing agent, and, if necessary, various auxiliary agents such as a catalyst, a foam stabilizer, and a flame retardant, with a composition B mainly containing a polyisocyanate to form a foamable polyurethane foam composition, which is then foamed and cured by a method such as slab foaming, injection foaming, spray foaming, laminate continuous foaming, lightweight banking, or injection backfilling.

[0003] Furthermore, for producing such polyurethane foams, various compounds have been incorporated as blowing agents into the polyol liquid mixtures described above, which are polyol liquid chemical compositions, examples of which are disclosed in, for example, JP-A-7-97472, JP-A-2008-266569, JP-A-2018-70708, etc. Among these, hydrofluorocarbon (HFC) blowing agents such as HFC-134a, HFC-245fa, and HFC-365mfc, which are considered to have relatively advantageous global warming potential, are known as suitable blowing agents. These hydrofluorocarbon blowing agents are recognized as alternatives to fluorocarbons that cause little or no ozone layer depletion. However, it is expected that the use of such alternatives will be restricted in the near future due to strong demands to address environmental issues. As a result, alternative blowing agents have been developed that are chemically unstable and therefore have low global warming potentials, such as halogenated hydroolefin (halogenated alkene) blowing agents called hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs), as well as hydrocarbons (HCs) such as pentane and cyclopentane.

[0004]

[0005] Incidentally, polyol liquid chemical compositions containing the above-mentioned blowing agents are generally stored outdoors after production in containers such as drums. However, if the boiling point of the added blowing agent is lower than 35°C, when the container containing such a polyol liquid chemical composition is exposed to a high-temperature environment, for example, when stored outdoors in the summer, the ambient temperature may reach 35°C or higher, causing the polyol liquid chemical composition to boil in the container. Furthermore, when such a container is opened, there are problems such as the risk of the polyol liquid chemical composition bumping, or the blowing agent vaporizing, causing deterioration of the polyol liquid chemical composition. Furthermore, there is also the inherent problem of the polyol liquid chemical composition leaking from the container and causing contamination of the surrounding soil. In particular, solid substances or materials such as red phosphorus are added to the polyol chemical composition to improve the properties of the polyurethane foam formed by reaction with polyisocyanate. In this case, such solid substances act as bubble points, making the polyol chemical composition more likely to boil in the container. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-97472 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-266569 [Patent Document 3] Japanese Patent Application Publication No. 2018-70708 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made against the background of the above circumstances, and the problem to be solved by the present invention is to provide a polyol liquid chemical composition that can be safely stored even in a high-temperature environment without causing boiling or bumping, and also to provide a polyol liquid chemical composition that can be stored in a container and suitably stored outdoors in direct sunlight in the summer. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present invention can be suitably implemented in various aspects as listed below, and the aspects described below can be adopted in any combination. It should be understood that the aspects and technical features of the present invention are not limited to those described below, but can be recognized based on the description of the entire specification and the inventive ideas disclosed therein.

[0008] (1) A polyol composition that forms polyurethane foam by reaction with polyisocyanate, characterized in that it contains, as a blowing agent, at least a low-boiling blowing agent having a boiling point of less than 35°C together with a liquid polyol, and the content of the low-boiling blowing agent is not more than the solubility in the polyol, so that the low-boiling blowing agent is dissolved in the polyol. (2) The polyol liquid chemical composition according to the above aspect (1), wherein the low-boiling point blowing agent is selected from the group consisting of hydrocarbons, hydrofluorocarbons, and halogenated alkenes. (3) The polyol liquid chemical composition according to the above aspect (1) or (2), wherein the foaming agent contains, together with the low-boiling-point foaming agent, another foaming agent having a boiling point of 35°C or higher. (4) The above-mentioned embodiment ( ) is characterized in that the foaming agent is contained in a total amount of 10 to 40 parts by mass per 100 parts by mass of the polyol. The polyol chemical composition according to any one of the above aspects (1) to (3). (5) The polyol chemical composition according to any one of the above aspects (1) to (4), wherein the polyol is an aromatic polyester polyol. (6) The polyol chemical composition according to any one of the aspects (1) to (5), wherein an aromatic polyester polyol and a polyether polyol are used in combination as the polyol. (7) The polyol chemical composition according to any one of the above aspects (1) to (6), further comprising a nonionic surfactant. (8) The polyol chemical composition according to any one of the aspects (1) to (7), wherein the nonionic surfactant is contained in an amount of 5 to 30 parts by mass per 100 parts by mass of the polyol. (9) The polyol chemical composition according to any one of the above aspects (1) to (8), further comprising a flame retardant. (10) The polyol liquid chemical composition according to the above aspect (9), wherein the flame retardant is a solid substance. (11) The polyol chemical composition according to any one of the aspects (1) to (10), characterized in that the viscosity at 20°C is 80 to 600 mPa·s. [Effects of the Invention]

[0009] Thus, in the polyol liquid chemical composition according to the present invention, a low-boiling-point blowing agent having a boiling point of less than 35°C is used as the blowing agent. Even when this low-boiling-point blowing agent is blended with a liquid polyol, the low-boiling-point blowing agent is used in a proportion not exceeding its solubility in the polyol, and the low-boiling-point blowing agent can be completely dissolved in the polyol. This makes it possible to increase the boiling point of the polyol liquid chemical composition as a whole. As a result, when such a polyol liquid chemical composition is stored in a container such as a drum and outdoors in direct sunlight in the summer, it is possible to effectively prevent the low-boiling-point blowing agent in the polyol liquid chemical composition from boiling due to an increase in temperature, and it is also possible to advantageously prevent the polyol liquid chemical composition stored in the container from bumping due to a change in pressure when the container is opened.

[0010] Furthermore, in the polyol liquid chemical composition according to the present invention, the low-boiling point blowing agent used as the blowing agent is present in a form in which it is sufficiently dissolved in the liquid polyol. Therefore, even at an environmental temperature higher than the boiling point of the low-boiling point blowing agent contained in the polyol liquid chemical composition, boiling of the polyol liquid chemical composition can be effectively prevented, and cloudiness of the liquid chemical composition due to insufficient dissolution of the low-boiling point blowing agent in the polyol can be advantageously prevented or suppressed. As a result, the long-term storage stability of the polyol liquid chemical composition can be effectively improved, and the long-term physical properties of the polyurethane foam formed by the reaction with polyisocyanate can be advantageously maintained.

[0011] Furthermore, in such a polyol liquid chemical composition according to the present invention, by further containing a nonionic surfactant together with the polyol and the low-boiling-point blowing agent, the solubility of the low-boiling-point blowing agent in the polyol can be effectively improved, making it possible to prepare a more uniform polyol liquid chemical composition, and thus making it possible to further increase the boiling temperature of such a polyol liquid chemical composition.

[0012] In addition, the polyol chemical composition according to the present invention exhibits the characteristic that even if a specified solid substance is added thereto, such a solid substance becomes a bubble point, and boiling of the polyol chemical composition in the storage container can be effectively suppressed. DETAILED DESCRIPTION OF THE INVENTION

[0013] The specific constitution of the polyol chemical composition according to the present invention will be explained in detail below.

[0014] First, the polyol chemical composition according to the present invention is composed primarily of a liquid polyol. The polyol is reacted with a predetermined polyisocyanate and foamed with a blowing agent containing at least a low-boiling blowing agent having a boiling point of less than 35°C to produce the desired polyurethane foam. The liquid polyol used therein may be any of various known liquid polyol compounds, such as polyester polyols, polyether polyols, polyolefin polyols, acrylic polyols, and polymer polyols, used alone or in suitable combinations. Among these, polyester polyols are preferred for use in the present invention. The total proportion of polyol in the polyol chemical composition is generally about 50 to 90% by mass, preferably about 60 to 85% by mass.

[0015] Among the polyols described above, polyester polyols that are preferably used include known polyols such as polyhydric alcohol-polycarboxylic acid condensation polyols and cyclic ester ring-opening polymer polyols. Examples of polyhydric alcohols that can be used include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, and pentaerythritol. Examples of polycarboxylic acids that can be used include succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, terephthalic acid, isophthalic acid, and anhydrides thereof. Examples of cyclic esters include ε-caprolactone.

[0016] In the present invention, among the polyester polyols described above, aromatic polyester polyols are preferred from the viewpoint of improving compatibility with low-boiling blowing agents and the flame retardancy of the resulting polyurethane foam. Specifically, phthalic acid-based polyester polyols are preferred, and combining two or more of these polyester polyols is also effective. Phthalic acid-based polyester polyols composed of condensates of phthalic acid, terephthalic acid, isophthalic acid, or anhydrides thereof with dihydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol are preferred. The aromatic polyester polyols are preferably used in a proportion of 50% by mass or more, preferably 60% by mass or more, and more preferably 70% by mass or more, of the polyol.

[0017] In the present invention, polyether polyols are also suitable as polyols, and their use in combination with the above-mentioned aromatic polyester polyols is particularly recommended. The use of such polyether polyols can advantageously improve the physical properties, such as strength, of the polyurethane foam formed by the reaction with polyisocyanate. The polyether polyols used here are obtained by reacting alkylene oxide with at least one initiator, such as a polyhydric alcohol, a sugar, an aliphatic amine, an aromatic amine, a phenol, or a Mannich condensation product. Examples of alkylene oxides include propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, and ethylene oxide. Polyhydric alcohols usable as initiators include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.; sugars include sucrose, dextrose, sorbitol, etc.; aliphatic amines include alkanolamines such as diethanolamine and triethanolamine, and polyamines such as ethylenediamine; aromatic amines include various methyl-substituted phenylenediamines, collectively known as tolylenediamine, as well as derivatives in which substituents such as methyl, ethyl, acetyl, and benzoyl have been introduced into the amino group, 4,4'-diaminodiphenylmethane, p-phenylenediamine, o-phenylenediamine, and naphthalenediamine; and phenols include bisphenol A and novolac phenolic resins. Mannich condensation products include those obtained by subjecting phenols, aldehydes, and alkanolamines to a Mannich condensation reaction.

[0018] The polyol liquid chemical composition according to the present invention contains, as at least one blowing agent, a low-boiling blowing agent having a boiling point of less than 35° C., together with the liquid polyol as described above, and such a low-boiling blowing agent is appropriately selected from various known non-fluorocarbon or fluorocarbon blowing agents having a boiling point of less than 35° C. In particular, in the present invention, organic low-boiling blowing agents belonging to halogenated alkenes, such as hydrocarbons (HCs) and hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), and hydrochlorofluoroolefins (HCFOs), are advantageously used.

[0019] Specifically, examples of hydrocarbons (HC) that are non-fluorocarbon blowing agents include isopentane, and examples of hydrofluorocarbons (HFCs) that are fluorocarbon blowing agents include 1,1,1,3,3-pentafluoropropane (HFC245fa). Further, examples of hydrofluoroolefins (HFOs) include pentafluorobutene isomers (HFO1354), hexafluorobutene isomers (HFO1336) such as 1,1,1,4,4,4-hexafluoro-2-butene (HFO1336mzz), heptafluoropentene isomers (HFO1447), and octafluoropentene isomers (HFO1438). In addition, examples of hydrochlorofluoroolefins (HCFOs) include 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), and 1-chloro-2,3,3-tetrafluoropropene (HCFO-1224yd).

[0020] In particular, among the low-boiling-point blowing agents described above, hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs) are chemically unstable and therefore have low global warming potentials, and therefore can be suitably used as environmentally friendly blowing agents. In order to improve the handleability of the blowing agents and further to advantageously enjoy the effects of the present invention, it is generally desirable that the lower limit of the boiling point of the low-boiling-point blowing agents described above is about 10°C.

[0021] Such low-boiling blowing agents are used in a proportion equal to or less than their solubility in the polyol constituting the polyol chemical composition to which they are added. This allows the low-boiling blowing agent to be completely dissolved in the polyol, resulting in a chemical composition that can be safely stored at high temperatures without problems such as boiling or bumping. The solubility of such low-boiling blowing agents varies depending on the type of low-boiling blowing agent and the type of polyol constituting the polyol chemical composition. Therefore, the solubility of the low-boiling blowing agent added is determined at 25°C for the polyol used, and the low-boiling blowing agent is added to the polyol chemical composition in a proportion equal to or less than the solubility. When a polyol chemical composition is prepared using multiple polyols, the solubility of the low-boiling blowing agent in a mixture of the multiple polyols is used, and the low-boiling blowing agent is added in a proportion equal to or less than the solubility.

[0022] In the present invention, in addition to using only the low-boiling blowing agent described above as the blowing agent contained in the polyol liquid chemical composition, other blowing agents having a boiling point different from that of the low-boiling blowing agent, i.e., a boiling point of 35°C or higher, can also be selected from various known blowing agents and used together with such low-boiling blowing agents. In such cases, organic blowing agents such as high-boiling (boiling point of 35°C or higher) hydrocarbons (HC), high-boiling hydrofluorocarbons (HFC), high-boiling hydrofluoroolefins (HFO), and high-boiling hydrochlorofluoroolefins (HCFO), specifically, normal pentane, 1,1,1,3,3-pentafluorobutane (HFC365mfc), isopropyl chloride, etc., are advantageously selected as the other blowing agents.

[0023] Furthermore, in the present invention, water as a blowing agent is advantageously used together with the low-boiling blowing agent described above, or together with the low-boiling blowing agent and other blowing agents. Thus, the presence of water in the polyol chemical composition allows the polyol chemical composition and the polyisocyanate (composition) to be mixed and reacted. When the water reacts with the polyisocyanate to produce carbon dioxide, reaction heat is generated. This heat effectively promotes the urethanization reaction and the isocyanuration reaction, further increasing the compressive strength of the resulting polyurethane foam. Furthermore, the presence of water in the polyol chemical composition allows the carbon dioxide generated during the reaction with the polyisocyanate to contribute to polyurethane foaming.

[0024] The amount of water used is generally selected to be 0.5 to 8 parts by mass, preferably 1 to 5 parts by mass, per 100 parts by mass of the total polyol in the polyol chemical composition. If the amount of water used exceeds 8 parts by mass per 100 parts by mass of the total polyol, the strength of the resulting polyurethane foam will be reduced. This is because the urea bonds formed by the reaction between water and polyisocyanate increase in the resin, and the polyisocyanate used in the isocyanuration reaction is consumed in the reaction with water, resulting in a decrease in the amount of polyisocyanate in the reaction system. On the other hand, if the amount of water used is less than 0.5 parts by mass, the effect of the water as a blowing agent will not be fully achieved.

[0025] The total content of the blowing agents, including the low-boiling blowing agent, in the polyol chemical composition according to the present invention is determined appropriately taking into consideration the solubility of the low-boiling blowing agent, but is generally 10 to 40 parts by mass, preferably 15 to 35 parts by mass, per 100 parts by mass of the total polyol in the polyol chemical composition. If the total amount of blowing agents is too small, the foaming properties will deteriorate, leading to problems such as insufficient foaming in spray foaming, for example. If the total amount of blowing agents is too large, problems such as the polyol chemical composition being prone to boiling in high-temperature environments will arise.

[0026] In addition, the polyol chemical composition according to the present invention preferably contains a nonionic surfactant in addition to the polyol and the low-boiling-point blowing agent described above. This nonionic surfactant functions as a compatibilizer between the polyol and the low-boiling-point blowing agent, and the inclusion of such a nonionic surfactant further improves the solubility of the low-boiling-point blowing agent in the polyol, thereby enabling the low-boiling-point blowing agent to be easily and completely dissolved in the polyol, thereby providing the advantage of increasing the boiling temperature of the polyol chemical composition.

[0027] Examples of the nonionic surfactants used herein include ether-type surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene lauryl ethers, polyoxyalkylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene polyoxypropylene monobutyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene nonylphenyl ethers, and polyoxyethylene polyoxypropylene monobutyl ethers; polyoxyethylene oleic acid esters, glycerin fatty acid esters, polyoxyethylene stearic acid esters, polyoxyethylene fatty acid (lauryl) methyl esters, and polyethylene glycol oleic acid monoesters. Examples of suitable olefins include ester-ether types such as polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl esters, sucrose fatty acid esters, and sorbitan fatty acid esters, alkyl glycosides such as octyl glucoside, alkanolamide types such as polyoxyethylene oleic acid amide and polyoxyethylene alkylamide, amine oxides such as dodecyl dimethylamine oxide and tetradecyl dimethylamine oxide, alkylamine types such as polyoxyethylene alkylamines and polyoxypropylene polyoxyethylene alkylamines, higher alcohols such as cetanol, stearyl alcohol, and oleyl alcohol, and polyoxyethylene distyrenated phenyl ether. Among these, polyoxyalkylene alkyl ethers are particularly preferred in the present invention because of their low freezing point and good affinity.

[0028] The amount of nonionic surfactant used is determined appropriately depending on the type of polyol and low-boiling-point blowing agent, the amount of low-boiling-point blowing agent used, etc., but is generally used in an amount of 5 to 30 parts by mass, preferably 8 to 25 parts by mass, per 100 parts by mass of the total polyol in the polyol liquid chemical composition. If the amount of nonionic surfactant used is less than 5 parts by mass, the compatibility-improving effect cannot be fully exerted, and if it exceeds 30 parts by mass, the foam properties of the polyurethane foam formed by reaction with polyisocyanate will be reduced.

[0029] Furthermore, various known flame retardants may be added to the polyol chemical composition of the present invention to impart the required flame retardancy to the polyurethane foam formed by the reaction with the polyisocyanate. The flame retardant used here is not particularly limited, and may be either liquid or solid. However, the features of the present invention are advantageously exhibited when a solid flame retardant is used. When the flame retardant is a solid substance such as a powder or granule, such a solid substance acts as a zeolite, making the polyol chemical composition prone to boiling and bumping, resulting in a lowered boiling point. However, according to the present invention, by dissolving a low-boiling point blowing agent in a polyol at a ratio equal to or less than its solubility in the polyol, particularly in the presence of a nonionic surfactant, the polyol chemical composition can maintain a high boiling point without lowering the boiling point, while also exhibiting the characteristic of further improving flame retardancy, even when such a solid flame retardant is included.

[0030] Examples of such solid flame retardants include known ones such as red phosphorus, phosphate-containing flame retardants, boron-containing flame retardants, metal stannate-containing flame retardants, metal hydroxides, etc. Such flame retardants are generally blended in an amount of 5 to 60 parts by mass, preferably 10 to 40 parts by mass, per 100 parts by mass of the total polyol in the polyol chemical composition.

[0031] In addition to the above-described components, the polyol chemical composition of the present invention may also contain known catalysts and foam stabilizers, as needed. The catalysts are used to promote the reaction between the polyol and polyisocyanate in the polyol chemical composition, and may be appropriately selected from various known catalysts. For example, well-known amine catalysts and imidazole catalysts may be used alone or in combination. Furthermore, urethane-forming catalysts and isocyanurate-forming catalysts may also be used in combination with these catalysts, as needed. Examples of urethanization catalysts include dibutyltin dilaurate, fatty acid bismuth salts such as bismuth octoate (bismuth 2-ethylhexyl), bismuth neodecanoate, bismuth neododecanoate, and bismuth naphthenate, lead naphthenate, and lead octoate (lead 2-ethylhexyl), while examples of isocyanuration catalysts include quaternary ammonium salts, fatty acid alkali metal salts such as potassium octoate and sodium acetate, and tris(dimethylaminopropyl)hexahydrotriazine. These various catalysts are typically used in an amount of 0.1 to 7 parts by mass, and preferably 0.5 to 5 parts by mass, per 100 parts by mass of the total polyol in the polyol chemical composition.

[0032] The foam stabilizer is used to uniformly adjust the cell structure of the polyurethane foam, and is appropriately selected from known foam stabilizers. Specific examples include polyoxyalkylene-modified dimethylpolysiloxane, polysiloxane oxyalkylene copolymer, polyoxyethylene sorbitan fatty acid ester, castor oil ethylene oxide adduct, and lauryl fatty acid ethylene oxide adduct. One of these may be used alone, or two or more may be used in combination. The amount of foam stabilizer to be added is determined appropriately depending on the desired foam characteristics and the type of foam stabilizer used, but is generally selected within the range of 0.1 to 10 parts by mass, preferably 1 to 8 parts by mass, per 100 parts by mass of the total polyol in the polyol chemical composition.

[0033] In addition, various conventionally known additives, such as formaldehyde scavengers such as urea and melamine, bubble-refining agents, plasticizers, and reinforcing substrates, can be appropriately selected and blended into the polyol chemical composition according to the present invention, as needed.

[0034] On the other hand, the polyisocyanate to be reacted with the polyol chemical composition according to the present invention reacts with the polyol in the polyol chemical composition to produce a polyurethane (resin). It is an organic isocyanate compound having two or more isocyanate groups (NCO groups) in the molecule, such as aromatic polyisocyanates such as diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, tolylene diisocyanate, polytolylene triisocyanate, xylylene diisocyanate, and naphthalene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate; urethane prepolymers having isocyanate groups at the molecular terminals, isocyanurate-modified polyisocyanates, carbodiimide-modified polyisocyanates, etc. These polyisocyanate compounds may be used alone or in combination of two or more. Generally, polymethylene polyphenylene polyisocyanate (polymeric MDI) is preferably used from the viewpoints of reactivity, economy, ease of handling, etc. Such polyisocyanates can also be used in the form of a composition in which various conventionally known auxiliaries are appropriately blended, as necessary.

[0035] The polyol liquid chemical composition containing the specified components according to the present invention can be produced by various conventionally known methods. Generally, the composition is prepared by mixing a polyol with a blowing agent containing a specified low-boiling-point blowing agent, and then, if necessary, adding a nonionic surfactant, a catalyst, a foam stabilizer, and other additives to form a uniform mixture. This is then used as a premix liquid and reacted with a polyisocyanate. When a nonionic surfactant is added, it is advantageous to first mix the nonionic surfactant with the polyol, and then mix the low-boiling-point blowing agent and other ingredients. Mixing the nonionic surfactant with the polyol first facilitates the subsequent mixing of the low-boiling-point blowing agent and the polyol through the surfactant. In this way, by adding and mixing a blowing agent containing a low-boiling point blowing agent with a polyol in the presence of a nonionic surfactant, the compatibility between the polyol and the blowing agent can be effectively increased.

[0036] The polyol liquid chemical composition prepared in this manner desirably has a viscosity at 20° C. of 80 to 600 mPa·s, preferably 100 to 550 mPa·s, and more preferably 150 to 500 mPa·s. If the viscosity is lower than 80 mPa·s, problems such as the liquid chemical composition being prone to boiling will arise, while if the viscosity is higher than 600 mPa·s, problems such as the liquid chemical composition being prone to bumping will arise.

[0037] The polyol liquid chemical composition according to the present invention obtained as described above is mixed with a polyisocyanate and foamed and cured to produce the desired polyurethane foam. Various known polyurethane foam production techniques can be employed, such as a laminate continuous foaming method in which a mixture of the polyol liquid chemical composition and the polyisocyanate is applied to a surface material and foamed and cured into a plate; an injection foaming method in which the mixture is injected and filled into a space requiring thermal insulation, such as an electric refrigerator, or into the honeycomb structure of a lightweight, high-strength board, and foamed and cured; or a spray foaming method in which the foamable composition according to the present invention is sprayed from the spray gun head of an on-site foaming machine onto a predetermined substrate (structure) and foamed and cured, thereby forming the desired polyurethane foam.

[0038] In particular, the polyol liquid chemical composition according to the present invention as described above can be safely stored even in a high-temperature environment without causing problems such as boiling or bumping. Therefore, even if the composition is placed in a container such as a drum prior to use in each of the above-mentioned applications and placed outdoors in direct sunlight in the summer, for example, boiling of the blowing agent can be advantageously suppressed or prevented, and problems such as bumping of the liquid chemical due to changes in air pressure when a container such as a drum is opened can be advantageously avoided. It also becomes possible to store the polyol liquid chemical composition for a long period of time and advantageously maintain the long-term physical properties of the polyurethane foam formed. [Example]

[0039] Below, several examples of the present invention will be shown and compared with comparative examples to more specifically clarify the features of the present invention, but it goes without saying that the present invention is not limited in any way by the description of such examples. Furthermore, it should be understood that in addition to the following examples and the specific description above, various changes, modifications, improvements, etc. can be made to the present invention based on the knowledge of those skilled in the art, as long as they do not deviate from the spirit of the present invention. Furthermore, unless otherwise specified, percentages (%) and parts shown below are all expressed on a mass basis.

[0040] The viscosity, foaming property, boiling property, and turbidity of the polyol liquid chemical compositions obtained in the following Examples and Comparative Examples were evaluated as follows.

[0041] (1) Viscosity measurement Measurement is carried out in accordance with JIS-K-7117-1 (1999) at a measurement temperature of 20°C using a Brookfield rotational viscometer, type B.

[0042] (2) Evaluation of foaming properties The polyol liquid chemical compositions prepared in the following Examples and Comparative Examples were used as test solutions, filled into sealable transparent glass bottles, sealed, and then heated in a hot water bath at temperatures of 30°C, 35°C, 38°C, or 40°C for 30 minutes. The bottles were then removed from the hot water bath and the foaming state of the test solutions was visually observed upon opening the lids. The foaming properties of each test solution were evaluated according to the following criteria, with a rating of "good" or better considered a pass. ◎: The test solution is not foaming. ○: Some bubbles were observed in the test solution. △: The test solution does not overflow from the glass bottle, but is quite foamy. ×: The test solution foams and overflows from the glass bottle.

[0043] (3) Evaluation of boiling properties Each test liquid is placed in a beaker and heated in a hot water bath at 35°C for 30 minutes, after which the test liquid in the beaker is visually observed to determine whether it boils or not. If the test liquid in the beaker is not boiling, it is rated as "○", if it is about to boil, it is rated as "△", and if it has boiled further, it is rated as "×". Of these ratings, "○" is considered to be a pass.

[0044] (4) Evaluation of turbidity Each test solution is weighed out to a total volume of 100 ml, and left to stand for 10 minutes in an atmosphere of 25°C, after which the turbidity of the weighed test solution is evaluated visually. The visual evaluation is carried out by 10 panelists according to the following evaluation criteria, and the obtained evaluation levels are averaged to evaluate the merits and demerits. ◎: No turbidity was observed in the test solution. ○: Almost no turbidity was observed in the test solution. △: The test solution is slightly cloudy. ×: The test solution is observed to be cloudy.

[0045] First, the following raw materials were prepared as components used in the following Examples and Comparative Examples. Note that the solubility of the blowing agent was determined at 25°C. Polyisocyanate: Polymeric MDI (Wannat e PM-130 manufactured by Wanka Chemical Japan Co., Ltd.) Polyol: Terephthalic acid-based polyester polyol (RFK 505 manufactured by Kawasaki Chemical Industries, Ltd.) (HCFO-1233zd Solubility: 35g / 100g - Polyol HFO-1336mzz Solubility: 5g / 100g - Polyol HFC245fa solubility: 20g / 100g-polyol HFC365mfc Solubility: 10g / 100g - Polyol Water solubility: 20g / 100g (polyol) Polyol: Isophthalic acid-based polyester polyol (RDK 142 manufactured by Kawasaki Chemical Industries, Ltd.) (HCFO-1233zd Solubility: 25g / 100g - Polyol HFO-1336mzz Solubility: 15g / 100g - Polyol Water solubility: 55g / 100g (polyol) Polyol: Polypropylene glycol (GP1000 manufactured by Sanyo Chemical Industries, Ltd.) (HCFO-1233zd Solubility: 40g or more / 100g - Polyol Water solubility: 100g or more / 100g-polyol) Foam stabilizer: Silicone foam stabilizer (SH-193 manufactured by Toray Dow Corning Co., Ltd.) Catalyst: Alkali metal carboxylate catalyst (Pucat 15G, potassium octylate, manufactured by Nippon Chemical Industry Co., Ltd.) Catalyst: Imidazole catalyst (Kao Corporation, Kao Raiser No. 390, 1,2-dimethylimidazole:dipropylene glycol = 70:30 [mass ratio]) Nonionic surfactant: Polyoxyalkylene alkyl ether (Emulgen LS106 manufactured by Kao Corporation) Nonionic surfactant: Polyoxyalkylene alkyl ether (Emulgen LS110 manufactured by Kao Corporation) Nonionic surfactant: nonylphenol polyethylene glycol ether (Tergitol NP-9, manufactured by The Dow Chemical Company) Flame retardant: Red phosphorus (Nova Excel 140, powder, manufactured by Rinkagaku Kogyo Co., Ltd.) Flame retardant: Phosphate (Fujifilm Wako Pure Chemical Industries, Ltd., ammonium dihydrogen phosphate, powder) Flame retardant: Phosphate ester [manufactured by Daihachi Chemical Industry Co., Ltd., TMCPP: tris(1-chloro-2-propyl)phosphate, liquid] Blowing agent: HCFO-1233zd (Honeywell, 1-chloro-3,3,3-trifluoropropene, boiling point 18.3°C) Blowing agent: HFO-1336mzz (manufactured by Chemours, 1,1,1,4,4,4-hexafluoro-2-butene, boiling point 33.4°C) Blowing agent: HFC245fa (manufactured by Central Glass Co., Ltd., 1,1,1,3,3-pentafluoropropane, boiling point 15.3°C) Blowing agent: HFC365mfc (SOLVAY Corporation, 1,1,1,3,3-pentafluorobutane, boiling point 40.2°C) Foaming agent: Water

[0046] The various raw materials prepared above, i.e., polyol, blowing agent, foam stabilizer, catalyst, nonionic surfactant, and flame retardant, were uniformly mixed in the various combinations and blending ratios shown in Tables 1 to 3 below to prepare various polyol liquid chemical compositions according to Examples 1 to 14 and Comparative Examples 1 to 6. When a nonionic surfactant was added, the nonionic surfactant was first mixed with the polyol and mixed uniformly, and then other additive components such as a blowing agent were added.

[0047] The various polyol liquid chemical compositions thus obtained were used as test liquids to evaluate their foaming, boiling, and turbidity, and the results obtained are summarized in Tables 1 to 3 below.

[0048] [Table 1]

[0049] [Table 2]

[0050] [Table 3]

[0051] As is clear from the results in Tables 1 and 2, the polyol chemical compositions prepared in Examples 1 to 14 according to the present invention were all found to be excellent in resistance to foaming, boiling, and turbidity. In particular, the polyol chemical compositions of Examples 8 to 11, which further contained a nonionic surfactant, were found to be even more excellent in resistance to foaming and turbidity. These results indicate that the polyol chemical compositions prepared in Examples 1 to 14, even when stored in a container such as a drum and exposed to a high-temperature environment, for example, outdoors in direct sunlight in the summer, are prevented from causing problems such as boiling in the container or bumping when the container is opened. Furthermore, it is believed that the risk of deterioration of the properties of the chemical composition due to vaporization of the blowing agent can be advantageously avoided.

[0052] In contrast, as is clear from the results shown in Table 3, in the polyol chemical compositions prepared in Comparative Examples 1 to 6, the amount of foaming agent used was greater than the solubility of the foaming agent in the polyol constituting the polyol chemical composition, and therefore the compositions were prone to foaming at high temperatures and had insufficient boiling and turbidity. Therefore, the polyol chemical compositions of these Comparative Examples are likely to cause problems such as boiling and bumping in high-temperature environments, making them difficult to store safely.

[0053] -Flame retardancy evaluation- The polyol chemical compositions containing the flame retardants prepared in Examples 12 to 14 were used, and the previously prepared polyisocyanate was applied to a 910 mm x 910 mm flexible board using a foaming machine (Graco A-25), with a base blow of 5 mm or less, followed by lamination to a thickness of 30 mm or less, to produce foams with a total thickness of approximately 60 mm. In this spray foaming, the polyol chemical composition and the polyisocyanate were mixed in a volume ratio of 1:1.

[0054] The foams thus obtained were evaluated for flame retardancy in accordance with JIS-A-9511 (2017) combustion test method B. Specifically, test pieces measuring 50 mm x 150 mm x 13 mm were cut from each foam, and one end of each test piece was burned for 60 seconds using a Bunsen burner equipped with a fishtail light. The time until the flame went out and the burning distance were then measured, and the results were evaluated according to the following criteria, with the results shown in Table 4 below. ◎: Burning distance is less than 30 mm and burning time is less than 60 seconds. ○: Burning distance is less than 60 mm and burning time is less than 120 seconds. △: Burning distance is 60mm or more or burning time is 120 seconds or more. ×: Burning distance is 60 mm or more and burning time is 120 seconds or more.

[0055] [Table 4]

[0056] As is clear from the results in Table 4, it was confirmed that the polyurethane foams obtained from any of the polyol chemical compositions had excellent flame retardancy. In particular, Examples 12 and 13 used red phosphorus and phosphate, respectively, which are powdered flame retardants. It can be seen that the inclusion of such powdered (solid) flame retardants did not cause any deterioration in the properties of the polyol chemical compositions.

Claims

1. 1. A polyol composition that forms a polyurethane foam upon reaction with a polyisocyanate, comprising: A polyol liquid chemical composition comprising a liquid polyol and an imidazole catalyst (excluding imidazole compounds in which a secondary amine functional group in the imidazole ring is substituted with a cyanoethyl group), and further comprising, as a blowing agent, at least a low-boiling-point blowing agent consisting of a halogenated alkene having a boiling point of less than 35°C and water, wherein the content of the low-boiling-point blowing agent is not more than its solubility in the polyol, and the low-boiling-point blowing agent is dissolved in the polyol, and the total content of the blowing agent including the low-boiling-point blowing agent and water is 15 to 35 parts by mass per 100 parts by mass of the polyol.

2. 2. The polyol liquid chemical composition according to claim 1, wherein the foaming agent contains, in addition to the low-boiling point foaming agent and water, another foaming agent having a boiling point of 35[deg.] C. or higher.

3. The polyol chemical composition according to claim 1 or 2, characterized in that water as the blowing agent is contained in an amount of 1 to 8 parts by mass per 100 parts by mass of the polyol.

4. 4. The polyol chemical composition according to claim 1, wherein the polyol is an aromatic polyester polyol.

5. 4. The polyol chemical composition according to claim 1, wherein an aromatic polyester polyol and a polyether polyol are used in combination as the polyol.

6. 6. The polyol chemical composition according to claim 1, further comprising a nonionic surfactant.

7. 7. The polyol chemical composition according to claim 6, wherein the nonionic surfactant is contained in an amount of 5 to 30 parts by mass per 100 parts by mass of the polyol.

8. 8. The polyol chemical composition according to claim 1, further comprising a flame retardant.

9. 9. The polyol chemical composition according to claim 8, wherein the flame retardant is a solid substance.

10. The polyol chemical composition according to any one of claims 1 to 9, characterized in that the viscosity at 20°C is 80 to 600 mPa·s.

11. 11. The polyol chemical composition according to claim 1, further comprising an alkali metal carboxylate catalyst in addition to the imidazole catalyst.

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