Rigid polyurethane foam made with hydrocarbon blowing agents and 1,1,1,4,4,4-hexafluorobuto-2-ene

Abstract

Polyurethane insulation foams are made in the presence of small amounts of cis- and / or trans-1,1,1,4,4,4-hexafluorobut-2-ene and hydrocarbon blowing agents. Very low lambda values ​​are obtained.

Description

Technical Field

[0001] The present invention relates to a method for producing rigid polyurethane foam.

Summary of the Invention

Problems to be Solved by the Invention

[0002] Rigid polyurethane foams are widely used as insulation foams for equipment such as refrigerators and freezers, as well as for other applications. The heat insulation properties of the foam insulation material are very important for the overall performance of the equipment. Better heat insulation reduces energy consumption and operating costs. Therefore, there is always a demand for polyurethane foams with a lower lambda (λ) value, that is, with even better performance as insulation materials.

[0003] To achieve this result, much work has been done over the past few decades, and currently, the insulation ability of polyurethane foams is considered to be approaching the technical limit. Therefore, even small improvements are becoming difficult to achieve. However, due to strong demand, further improvements in insulation ability, even if they are small, are welcomed in the market.

[0004] Currently, rigid polyurethane foams in commercial applications with the highest insulation ability are produced from foam formulations containing mostly o-toluenediamine-initiated polyether polyols. By using this polyol in combination with, for example, a vacuum-assisted process as described in WO2010 / 046361, polyurethane foams with very low lambda values can be successfully produced in the manufacturing settings of commercial equipment. However, since o-toluenediamine-initiated polyols are expensive, it is desirable to limit the amount used in the foam formulation. The equipment required to perform the vacuum assist method may not be available at all manufacturing sites.

[0005] Certain hydrofluoroolefin (HFO) and hydrochlorofluoroolefin (HCFO) compounds are associated with low lambda values ​​when used as blowing agents in the production of rigid polyurethane foams. However, these compounds, like o-toluenediamine-started polyols, are relatively expensive, and their use as blowing agents adds a significant cost. A specific HFO, 1,1,1,4,4,4-hexafluorobuto-2-ene (HFO-1336mzz), is used in combination with cyclopentane and other blowing agents to produce rigid polyurethane foams. See, for example, AU2016-200022A and WO2019 / 096763. WO2019 / 096763 describes a polyurethane foam system containing 4-20 parts HFO-1336mzz and 2-10 parts cyclopentane (based on polyol weight). These foam systems are used to produce composite panels, such as composite panels for refrigeration / trailers. The foam produced using this process has a core density of approximately 45-50 kg / m³ at an average plate temperature of 25°C. 3 Furthermore, the lambda value has been reported to be 20 mW / mK or higher. HFO-1336mzz itself is said to cause the foam to become excessively brittle.

[0006] In one aspect of this invention, a) at least one polyisocyanate, b) at least one polyol, c) at least one urethane catalyst, d) at least one foam-stabilizing surfactant, e) Based on the total weight of components b), c), d), and e), add 0-3 weight percent water. f) 1 to 6 parts by weight of cis- and / or trans-1,1,1,4,4,4-tetrafluorobuto-2-ene per 100 parts by weight of components b), c), d), and e), g) A polyurethane foam is a reaction product of a reaction system comprising 8 to 30 parts by weight of one or more hydrocarbons having 4 to 6 carbon atoms per 100 parts by weight of components b), c), d), and e).

[0007] The present invention also relates to a method for producing polyurethane foam, which includes forming a reaction system as described in relation to the first aspect, and curing the reaction system to produce polyurethane foam.

[0008] The present invention also, A) Arranging the outer shell member and the inner liner member, and defining a cavity between them, B) Introducing the reaction system of the first embodiment into the cavity, C) A method for manufacturing an insulated cabinet, comprising curing the reaction system so that the reaction system expands and reacts, thereby generating a polyurethane foam that fills the cavity and adheres to the outer shell member and the inner liner member.

[0009] The foam produced according to the present invention is characterized by remarkably good insulation properties, i.e., a low lambda value. The lambda value is often reduced by 2-5% or more compared to other similar foams prepared using only hydrocarbon blowing agents. The lambda value obtained in the present invention is almost the same as the value obtained when 1,1,1,4,4,4-tetrafluorobuto-2-ene is used in large quantities as the sole physical blowing agent. The latter result is particularly remarkable and beneficial because it allows the present invention to replace most of the expensive 1,1,1,4,4,4-tetrafluorobuto-2-ene with a less expensive hydrocarbon blowing agent, reducing material costs.

[0010] Another advantage of the present invention is that an excellent lambda value can be obtained even when the polyol component contains only a small amount of o-toluenediamine-initiated polyol. This benefit allows many of the o-toluenediamine-initiated polyols to be replaced with less expensive polyols, again reducing raw material costs while providing excellent thermal insulation properties.

[0011] Component a) is at least one organic polyisocyanate, examples of which include aliphatic, alicyclic, aromatic aliphatic, or aromatic polyisocyanates, or any two or more combinations thereof. The organic polyisocyanate may have, for example, up to 250 isocyanate equivalents. Specific organic polyisocyanates include, for example, alkylene diisocyanates, particularly those having 4 to 12 carbon atoms in the alkylene portion, such as 1,12-dodecane diisocyanate, 2-ethyltetramethylene 1,4-diisocyanate, 2-methyl-pentamethylene 1,5-diisocyanate, 2-ethyl-2-butylpentamethylene 1,5-diisocyanate, tetramethylene 1,4-diisocyanate, preferably This includes alicyclic diisocyanates such as hexamethylene 1,6-diisocyanate; cyclohexane-1,3- and -1,4-diisocyanate, as well as any mixture of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanato-methylcyclohexane (isophorone diisocyanate), 2,4- and 2,6-hexahydrotoluene diisocyanate and mixtures of these isomers, 4,4'-, 2,2 This includes '- and 2,4'-dicyclohexylmethane diisocyanates and mixtures of their isomers, aromatic aliphatic diisocyanates such as 1,4-xylylene diisocyanate and mixtures of xylylene diisocyanate isomers, preferably aromatic diisocyanates, as well as polyisocyanates, such as 2,4- and 2,6-toluene diisocyanates and mixtures of their corresponding isomers, 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanates and mixtures of their corresponding isomers, mixtures of 4,4'- and 2,4'-diphenylmethane diisocyanates, polyphenyl-polymethylene polyisocyanates, mixtures of 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanates, and polyphenyl-polymethylene polyisocyanates (crude MDI), as well as mixtures of crude MDI and toluene diisocyanate.

[0012] Modified polyisocyanates, i.e., products obtained by chemical reactions of organic diisocyanates and / or polyisocyanates, may also be used. Specific examples include esters, ureas, biuret, allophanates, uretonemine, carbodiimides, isocyanurates, uretdiones, and / or urethane-containing diisocyanates and / or polyisocyanates, which preferably contain 33.6 to 15 percent by weight, preferably 31 to 21 percent by weight, of isocyanate groups based on the total weight of the modified polyisocyanate.

[0013] Component b) is at least one polyol. A wide range of polyols can be used, depending in part on the desired properties of the polymer foam. Thus, useful polyols include polyether polyols, polyester polyols, hydroxyl-terminated polybutadiene rubbers, and polyacrylate polyols, as well as other types. Useful polyols have about 30 to 3000 hydroxyl equivalents, but it is preferable that at least one polyol has 30 to 1000, particularly 75 to 560 or 100 to 350 hydroxyl equivalents. Polyols may have a hydroxyl functional value of 2 to 8 or more hydroxyl groups per molecule.

[0014] Component b) preferably comprises at least one polyether polyol having a hydroxyl equivalent of 75 to 560, particularly 100 to 350, and a nominal hydroxyl functional value of at least 3, for example, 3 to 8. Examples of such polyether polyols include, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, glycerin, trimethylolpropane, trimethylolethane, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanediethanol, 1,2,6-hexanetriol, monoethanolamine, diethanolamine, triethanolamine, pentaerythritol, erythritol, sorbitol, The invention contains one or more ethoxylates and / or propoxylates of hydroxyl and / or amine groups containing a starter having 30 to 59 equivalents, comprising one or more of the following: sucrose, mannitol, o-toluenediamine (toluene-2,3-diamine and / or toluene-3,4-diamine), 2,4-, 2,5-, and / or 2,6-toluenediamine, N,N,N',N'-tetrakis(2-hydroxypropyl)-ethylenediamine, diethyltoluenediamine, dimethylthiotoluenediamine, and combinations thereof.

[0015] In some embodiments of the present invention, component b) contains an alkoxylated o-toluenediamine polyol in an amount of 65%, 50%, 40%, 35%, 30%, or 25% or less of the total weight of components b), c), d), and e). Such an alkoxylated o-toluenediamine polyol may have hydroxyl equivalents of 75 to 560 or 100 to 350. The alkoxylated o-toluenediamine polyol may be absent, or if present, may constitute at least 5%, at least 10%, or at least 15% of the total weight of components b), c), d), and e). A significant advantage of the present invention is that a very low lambda value can be obtained even when the alkoxylated o-toluenediamine polyol is absent or present in small amounts.

[0016] Another useful polyol is polyether polyols having hydroxyl equivalents of 75–560, particularly 100–350, and a nominal hydroxyl functional value of 6–8. Examples of such polyols are alkoxylated sorbitol or alkoxylated sucrose polyols. If present, such polyols may constitute, for example, at least 5%, at least 10%, or at least 25%, and up to 80%, or up to 60%, of the total weight of components b), c), d), and e).

[0017] Another useful polyol is a polyether having a nominal hydroxyl functional value of 2–4 and 75–560 hydroxyl equivalents, which is not an alkoxylate of o-toluenediamine. Examples of such polyether polyols include alkoxylates of one or more low molecular weight hydroxyl-containing compounds such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, glycerin, trimethylolpropane, trimethylolethane, erythritol, pentaerythritol, triethanolamine, triisopropanolamine, etc.; alkoxylates of one or more amines such as 2,4-toluenediamine, 2,5-toluenediamine, bis(aminoethyl)amine, ethylenediamine, etc.; and alkoxylates of alkanolamines such as monoethanolamine, diethanolamine, monoisopropanolamine, diisopropanolamine, aminoethylethanolamine, etc.

[0018] In any of the aforementioned polyols that are alkoxylates, the alkoxide may be one or more of the following, for example: 1,2-propylene oxide, 1,3-propylene oxide, ethylene oxide, 1,2- or 2,3-butylene oxide, tetrahydrofuran, styrene oxide, or cyclohexane oxide. Propoxylates and / or ethoxylates are particularly preferred. Such alkoxylates are preferably not halogenated.

[0019] Further useful polyols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, glycerin, trimethylolpropane, trimethylolethane, erythritol, pentaerythritol, sorbitol, and sucrose, which have 30 to 74 hydroxyl equivalents and a nominal hydroxyl functional value of 2 to 8, particularly 2 to 6 or 3 to 4.

[0020] Another useful polyol is polyester polyol. Useful polyester polyols may be reaction products of, for example, organic dicarboxylic acids (or their corresponding acid anhydrides or esters) having about 2 to about 12 carbon atoms, preferably aromatic dicarboxylic acids having 8 to 12 carbon atoms, with polyhydric alcohols, preferably diols and / or triols having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms. Suitable examples of dicarboxylic acids are succinic acid, glutaric acid, adipic acid, suberic acid, azelanic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, preferably orthophthalic acid, isophthalic acid, terephthalic acid, and the isomer naphthalenedicarboxylic acid. Dicarboxylic acids may be used alone or mixed with each other. Examples of dihydric and polyhydric alcohols used to produce polyester polyols include ethanediols, diethylene glycol, 1,2- and 1,3-propanediols, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, glycerol, and trimethylolpropane. Modified aromatic polyester polyols, such as those described in U.S. Patent No. 6,359,022, which contain one or more pendant aliphatic hydrocarbyl groups having six or more carbon atoms in a linear or branched chain, are also useful. Furthermore, polyester polyols made from lactones such as ε-caprolactone or hydroxycarboxylic acids such as ω-hydroxycaproic acid and hydrobenzoic acid may also be used. Hybrid polyether-polyester polyols, such as those described in WO2011 / 137011, are also useful.

[0021] Another useful polyol is a polyester or polyether polyol with more than 560 hydroxyl equivalents.

[0022] Component c) is a urethane catalyst, i.e., a material that catalyzes the reaction of an alcohol group or water with an isocyanate group. Among suitable urethane catalysts are tin(II) and tin(IV) catalysts, catalysts containing other Group III to Group XV metals, tertiary amine compounds, amidines, tertiary phosphines, etc. Among useful urethane catalysts are, for example, trimethylamine, triethylamine, N-methylmorpholine, N-ethylmorpholine, N,N-dimethylbenzylamine, N,N-dimethylethanolamine, dialkylimidazole compounds, 2,2'-dimorpholinodiethyl ether, N,N,N',N'-tetramethyl-1,4-butanediamine, N,N-dimethylpiperazine, 1,4-diazabicyclo-2,2,2-octane, tetraalkylguanidine compounds, 2,2,2-dimethylaminoethoxyethylmethylaminoethanol, N,N-dimethylcyclohexylamine, 1,3,5-tris[3-(dimethylamino)propyl]hexahydro-1,3,5-triazine, triethylenediamine, dimethylalkylamine having an alkyl group containing 4 to 18 carbon atoms, pentamethyldiethylenetriamine, tetramethylethylenediamine, dibutyltin dilaurate, dimethyltin dilaurate, stannous octoate, stannous oleate, stannic chloride, stannous chloride, di-n-butyltin bis(isooctyl mercaptoacetate), and other organotin compounds of the formula SnR n (OR) 4-n (where R is alkyl or aryl and n is 0 to 2).

[0023] One or more urethane catalysts are used in a catalytically effective amount. The urethane catalyst can constitute, for example, up to 5%, or up to 4%, of the total weight of components b), c), d), and e).

[0024] Component d) is one or more foam stabilizing surfactants. Suitable surfactants include silicones such as silicone oil, and organosilicone-polyether copolymers including polydimethylsiloxane and polydimethylsiloxane-polyoxyalkylene block copolymers as described in U.S. Patent No. 4,483,894, but are not limited thereto. Other suitable surfactants are linear siloxane-polyoxyalkylene block copolymers having an average molecular weight of at least 30,000 as disclosed in U.S. Patent 4,022,722. Still other suitable surfactants include organic surfactants such as nonylphenol ethoxylate and ethylene oxide / butylene oxide block copolymers. Suitable surfactants are widely commercially available from Evonik Industries, Momentive Performance Materials, and The Dow Chemical Company.

[0025] Component d) can constitute, for example, at least 0.25% and at most 10% of the total weight of components b), c), d), and e). Preferred amounts are, on the same basis, at least 0.5% or at least 1%, and at most 5% or at most 3%.

[0026] Component f) is the cis or trans isomer of 1,1,1,4,4,4-hexafluorobut-2-ene, or a mixture of the cis isomer and the trans isomer in any ratio. Component f) is present in an amount of 1 to 6 parts by weight per 100 parts by weight of components b), c), d), and e). Preferred amounts are, on the same basis, 1 to 4 parts by weight or 2 to 4 parts by weight.

[0027] Component g) is one or more hydrocarbons having 4 to 6 carbon atoms. Examples of such hydrocarbons include n-butane, isobutane, cyclobutane, n-pentane, isopentane, neopentane, cyclopentane, n-hexane, 2-methylpentane, 3-methylpentane, cyclohexane, 2-ethylbutane, 2,2-dimethylbutane, and 2,3-dimethylbutane, as well as any two or more mixtures thereof. One or more pentanes are preferred, and cyclopentanes are particularly preferred. Component g) is present in an amount of 8 to 30 parts by weight, preferably 10 to 20 parts by weight, or 12 to 20 parts by weight, per 100 parts by weight of components b), c), d), and e).

[0028] The reaction system may include a variety of optional components in addition to those already described. Such optional components may include isocyanate trimerization catalysts. Examples of isocyanate trimerization catalysts include strong bases such as alkali metal phenolates, alkali metal alkoxides, alkali metal carboxylates, and quaternary ammonium salts. Another optional component is one or more flame retardants such as phosphorus-containing flame retardants, halogenated flame retardants, and melamine. The reaction system may also contain one or more fillers and / or reinforcing agents such as fiberglass, carbon fiber, flake glass, mica, talc, and calcium carbonate; one or more pigments and / or colorants such as titanium dioxide, iron oxide, chromium oxide, azo / diazo dyes, phthalocyanines, dioxazine, and carbon black; one or more biocides; one or more preservatives; one or more antioxidants; and so on.

[0029] The foam is prepared according to the present invention by combining components a) to g) with any optional component, and then component g) volatilizes to create a reaction system that is cured under conditions such that the polyisocyanate reacts with the polyol, water, and other isocyanate-reactive components to produce a polymer foam. Cis and / or trans-1,1,1,4,4,4-hexafluorobuto-2-ene may also volatilize during the foaming process. The isocyanate index (100 times the ratio of isocyanate groups to isocyanate reactive groups provided to the reaction mixture) is at least 90, preferably at least 100 or at least 110. If a polyurethane-isocyanurate foam is desired, the isocyanate index is preferably at least 200, at least 250, or at least 300. In some embodiments, the isocyanate index may be up to 1000, up to 600, up to 500, or up to 450, up to 250, up to 200, up to 150, or up to 125.

[0030] The order in which components a) to g) are mixed is not particularly important, but if all other components are already present, it is generally preferable to combine the polyisocyanate with water and the polyol. Components b) to e), b) to f), or b) to g) may be combined first to form a compounded polyol component, which may then be combined with the remaining components to produce a reaction system. In certain embodiments, components b) to e) or b) to f) are combined to form a compounded polyol component, which may then be mixed with components f) (if necessary), g), and a) either simultaneously or sequentially to produce a reaction system. However, producing reaction reactions by combining various components at once or in various subcombinations is also within the scope of the present invention.

[0031] Polyisocyanates, polyols, and water typically react spontaneously when mixed, even at room temperature, and the exothermic reaction heat is often sufficient to generate the temperature required to volatilize the hydrocarbon blowing agents (component g)) and components f). Therefore, in many cases, it is only necessary to form the reaction mixture at or near room temperature, such as 10–35°C, and the curing reaction can be completed without further heating. However, if necessary, the components may be heated when or before the reaction mixture is formed, and / or once the reaction system is formed, it may be heated to a higher temperature to accelerate the curing reaction.

[0032] The foam can be produced in a free-rise process, which allows the foam formulation to be distributed into an open area and allowed to rise freely vertically to generate a bunstock. In other embodiments, the foam is produced in a continuous process by continuously distributing the reaction mixture onto a moving belt or substrate. The substrate is a pair of sheets or panels, and a second layer of the pair of sheets or panels may be placed continuously on top of the reaction mixture to form a sandwich structure. The reaction mixture hardens to form a foam that adheres to the substrate.

[0033] In embodiments of particular interest, the foam is produced by introducing a reaction mixture into a cavity or defined space in which expansion and curing are carried out. The cavity or defined space may be defined, for example, by an insulating panel or wall, or by the wall of a refrigerator, freezer, cooler, dishwasher, water heater, or other appliance. The cavity or defined space may be an annular mold or cavity, such as those used to produce pre-insulated pipes. In particular, the cavity can be formed by arranging an outer shell member and an inner liner member and defining a space between them. The outer shell layer may form, for example, the outer wall of an appliance in which insulation is desired. The inner liner may form, for example, the inner wall of such an appliance. The outer shell and inner liner may each be made of a metal such as steel or aluminum, and a variety of structural thermoplastic or thermosetting resins such as polystyrene, high-impact polystyrene (HIPS), acrylonitrile-butadiene-styrene interpolymer, polyamide, polyester, or rigid polyurethane resin. In certain embodiments, the device is a refrigerator or freezer, the outer shell is metal, and the inner liner is a structural thermoplastic resin such as polystyrene, high-impact polystyrene (HIPS), acrylonitrile-butadiene-styrene interpolymer, polyamide, polyester, or rigid polyurethane resin.

[0034] The outer shell and inner liner are arranged to form a cavity into which the reaction system is introduced and cured to form a polyurethane foam. The shell and liner can be held in their respective positions using jigs or other mechanical devices.

[0035] The reaction system is introduced into the cavity, for example, by pouring or injecting it through one or more injection ports. The amount of reaction system introduced is at least sufficient to fill the cavity as the reaction system expands and hardens. As the reaction mixture expands, the cavity may be "overpacked" by introducing some excess reaction mixture beyond the minimum amount required to fill the cavity. For example, the cavity may be 5-40% overpacked, i.e., as the reaction mixture expands, 5-40% or more of the reaction system is introduced beyond the minimum amount required to fill the cavity.

[0036] Once introduced, the reaction system expands and hardens, producing polyurethane foam within the cavity. The polyurethane foam typically adheres to both the outer shell and the inner liner, providing insulation in addition to imparting mechanical strength and stability to the resulting assembly.

[0037] For example, as described in WO2007 / 058793 and WO2010 / 044361, subatmospheric pressure may be maintained in the cavity during the filling step and, optionally, for at least part of the curing step. Reduced pressure may be, for example, 300-950 mbar (30-95 kPa), preferably 400-950 mbar (40-95 kPa), and more preferably 700-950 mbar (50-95 kPa), before or immediately after the foam-forming composition is charged into the mold. Reduced pressure is preferably maintained until the reaction system is introduced into the mold, and more preferably until the reaction system expands and gels (i.e., forms a three-dimensional polymer network).

[0038] The foam produced according to the present invention has a density of 20-120 kg / m³ when measured, for example, according to ASTM 1622-88. 3 , 24~80 kg / m 3 , 28~64 kg / m 3 , or 28-40 kg / m 3The foam may have a density of . The bubbles may be at least about 70 percent isolated, at least about 80 percent isolated, or at least about 85 percent isolated. The foam often has a lambda value of 20.0 or less, 19.0 or less, 18.5 or less, and even 18.25 mW / m-°K or less when measured according to EN-12667 at an average plate temperature of 10°C.

[0039] The following examples are provided to illustrate the present invention, but do not limit its scope. All parts and percentages are by weight unless otherwise indicated.

[0040] The compounded polyol A is a mixture of polyether polyol, urethane catalyst, silicone surfactant, and water. It contains 1.8% by weight of water and 25% by weight of o-TDA polyol having a functional value of 4 and a hydroxyl value of approximately 440 mg KOH / g. The compounded polyol A has a hydroxyl value of 395 mg KOH / g.

[0041] The compounded polyol B is a mixture of polyether polyol, urethane catalyst, silicone surfactant, glycerin, and water. It contains 1.5% by weight of water and 59% by weight of o-TDA polyol having a functional value of 4 and a hydroxyl value of 370-440 mg KOH / g. The compounded polyol B has a hydroxyl value of 418 mg KOH / g.

[0042] PMDI is a polymeric MDI with an isocyanate content of approximately 31% by weight.

[0043] Example 1 and Comparative Sample A To prepare Example 1, 100 parts by weight of compounded polyol A is combined with 3 parts by weight of trans-1,1,1,4,4,4-hexafluorobuto-2-ene, 13.2 parts by weight of cyclopentane, and then 140 parts of PMDI (122 index) at approximately 23°C to form a reaction mixture. A portion of the reaction mixture is immediately poured into a rectangular "bullet" mold having dimensions of 200cm x 20cm x 5cm (~6'6" x 8" x 2"). The bullet mold is oriented perpendicular to the 200cm direction and preheated to 45±5°C. The bullet mold is at atmospheric pressure. The composition is allowed to expand relative to its own weight and harden inside the mold. An amount of polyurethane-forming composition is selected such that the resulting foam just fills the mold. The density of the resulting foam is then measured and reported as the minimum filling density (MFD). The foam is removed from the mold, except that the mold is 10% overpacked, and the experiment is repeated. The lambda value of the resulting form is determined according to EN 12667 using an average plate temperature of 10°C.

[0044] Pour another portion of the reaction mixture into a 20cm x 20cm x 20cm box and visually assess the creaming time. Press a spatula onto the surface of the curing reaction mixture and assess the gelling time (the time after mixing when the polymer strings adhere to the spatula) and the tack-free time (the time after mixing when the polymer no longer adheres to the spatula).

[0045] The aforementioned experiment is repeated using the formulation from Example 1, except that a partial vacuum (-0.2 atmospheres, actually 80 kPa) is drawn in a bullet shape during filling and bubble expansion until the reaction system gels.

[0046] Comparative sample A is prepared in a similar manner by combining 100 parts by weight of compounded polyol A with 14.5 parts of cyclopentane and 140 parts of PMDI (1.22 index). Cream time, gel time, and tack-free time are measured as before. Minimum pack density and lambda value are determined for foams prepared in a bullet type at atmospheric pressure and reduced pressure, as described for Example 1.

[0047] The results of the aforementioned tests are shown in Table 1. [Table 1]

[0048] As the data in Table 1 show, a significant decrease in lambda is achieved by adding 3 parts by weight of 1,1,1,4,4,4-hexafluorobuto-2-ene to the formulation and reducing the amount of cyclopentane by approximately 10%. The lambda value obtained in Example 1 is very low, especially considering that the foam formulation contains a fairly low proportion of o-TDA-initiated polyol. No significant changes were observed in cream, gelation, or tack-free time.

[0049] Examples 2 and 3 and Comparative Sample B Foam Examples 2 and 3 were prepared by combining 100 parts of formulated polyol B with 3 parts of either trans- or cis-1,1,1,4,4,4-hexafluorobuto-2-ene, 14.8 parts of cyclopentane, and PMDI (119 index), using the same general method as described in the previous example. Comparative sample B was prepared by combining 100 parts of formulated polyol B with 16 parts of cyclopentane and PMDA (121 index), and foaming the reaction mixture obtained by a similar method. Cream, gel, and tack-free times were measured in each case, and the minimum packing density and lambda were also measured for the foam produced in bullet form at atmospheric pressure and reduced pressure, respectively. The results of the foam tests are shown in Table 2. [Table 2]

[0050] The data in Table 2 demonstrate that a significant reduction in lambda value is achieved in the present invention using either the cis or trans isomer of 1,1,1,4,4,4-hexafluorobuta-2-ene. In this case, the improvement in insulating ability is also achieved in foam formulations containing most o-TDA-initiated polyols. Such foams have long been known to have very low lambda values, and the further significant reduction is unexpected and quite beneficial.

[0051] Example 4 and comparative samples C and D Comparative sample C is prepared by combining 100 parts by weight of compounded polyol A with 14.5 parts of cyclopentane and PMDI (112 index) using a reduced-pressure mold and 10% overpacking, in the same general manner as described in the previous example, and processing the resulting reaction mixture into a foam. Comparative sample D is prepared in a similar manner by combining 100 parts by weight of compounded polyol A with 6.6 parts of cyclopentane, 18 parts of cis-1,1,1,4,4,4-hexafluorobuto-2-ene and PMDI (112 index).

[0052] Example 4 is prepared in the same general manner by combining 100 parts of compounded polyol B, 3 parts of cis-1,1,1,4,4,4-hexafluorobuto-2-ene, 14.8 parts of cyclopentane, and PMDI (112 index).

[0053] Lambda was measured. The foam density was approximately 35 g / L in all cases. The composition and foam test results for each case are shown in Table 3. [Table 3]

[0054] As can be seen by comparing comparative samples C and D, a 5.8% lambda reduction (compared to comparative sample C) is obtained by reducing the amount of cyclopentane to 6.6 parts while including 18 parts of cis-1,1,1,4,4,-hexafluorobuta-2-ene. This result requires a large amount of expensive 1,1,1,4,4,4-hexafluorobuta-2-ene material, resulting in a significant cost disadvantage, as 18 parts of cis-1,1,1,4,4,4-hexafluorobuta-2-ene are required to achieve a 1.1 mW / m-°K reduction in lambda. Examples 1 and 4 demonstrate that in two different polyol systems, more than half to almost 75% of the benefit can be obtained in the present invention by adding only 1 / 6 (3 parts) of the amount of 1,1,1,4,4,4-hexafluorobuta-2-ene instead. In Example 1, a reduction of 0.6 mW / m-°K was obtained using only 3 parts of 1,1,1,4,4,4-hexafluorobuta-2-ene, and in Example 4, 0.8 mW / m-°K was obtained while using 3 parts of 1,1,1,4,4,4-hexafluorobuta-2-ene. In this invention, most of the advantages of using 1,1,1,4,4,4-hexafluorobuta-2-ene are obtained at only a fraction of the usage level and at only a fraction of the cost. The invention described in the original claims of this application is listed below. [1] A method for producing polyurethane foam, comprising forming a reaction system and curing the reaction system to produce the polyurethane foam, wherein the reaction system is a) at least one polyisocyanate, b) at least one polyol, c) at least one urethane catalyst, d) at least one foam-stabilizing surfactant, e) Based on the total weight of components b), c), d), and e), add 0-3 weight percent water. f) 1 to 6 parts by weight of cis- and / or trans-1,1,1,4,4,4-tetrafluorobuto-2-ene per 100 parts by weight of components b), c), d), and e), g) A method comprising 8 to 30 parts by weight of one or more hydrocarbons having 4 to 6 carbon atoms per 100 parts by weight of components b), c), d), and e). [2] The method according to [1], wherein the reaction system contains 2 to 4 parts by weight of cis and / or trans-1,1,1,4,4,4-tetrafluorobuto-2-ene per 100 parts by weight of components b), c), d), and e). [3] The method according to [1] or [2], wherein the reaction system contains 12 to 20 parts by weight of one or more hydrocarbons having 4 to 6 carbon atoms per 100 parts by weight of components b), c), d), and e). [4] The method according to any one of [1] to [3], wherein the reaction system contains 30 weight percent or less of alkoxylated o-toluenediamine polyol based on the total weight of components b), c), d), and e). [5] The method according to any one of [1] to [4], wherein the reaction system is introduced into a cavity, cured in the cavity, and a pressure of 700 to 950 millibars is actually maintained in the cavity when the reaction system is introduced into the cavity. [6] A polyurethane foam manufactured by any of the methods described in [1] to [5]. [7] The form described in [6] exhibits a maximum lambda value of 18.5 mw / m-°K when measured according to EN 12667 at an average plate temperature of 10°C. [8] The form described in [6] exhibits a maximum lambda value of 18.25 mw / m-°K when measured according to EN 12667 at an average plate temperature of 10°C. [9] When measured according to ASTM 1622-88, 28-40 kg / m 3 A form having the density of any of the following: [6] to [8].

[10] A method for manufacturing an insulated cabinet, A) Arranging the outer shell member and the inner liner member, and defining a cavity between them, B) Introducing the reaction system into the cavity, C) The reaction system is cured so that it expands and reacts, thereby generating a polyurethane foam that fills the cavity and adheres to the outer shell member and the inner liner member, wherein the reaction system a) at least one polyisocyanate, b) at least one polyol, c) at least one urethane catalyst, d) at least one foam-stabilizing surfactant, e) Based on the total weight of components b), c), d), and e), add 0-3 weight percent water. f) 1 to 6 parts by weight of cis- and / or trans-1,1,1,4,4,4-tetrafluorobuto-2-ene per 100 parts by weight of components b), c), d), and e), g) A method comprising 8 to 30 parts by weight of one or more hydrocarbons having 4 to 6 carbon atoms per 100 parts by weight of components b), c), d), and e).

[11] The method according to

[10] , wherein the reaction system contains 2 to 4 parts by weight of cis and / or trans-1,1,1,4,4,4-tetrafluorobuto-2-ene per 100 parts by weight of components b), c), d), and e), and 12 to 20 parts by weight of one or more hydrocarbons having 4 to 6 carbon atoms per 100 parts by weight of components b), c), d), and e).

[12] The method according to

[10] or

[11] , wherein the reaction system contains 65 weight percent or less of alkoxylated o-toluenediamine polyol based on the total weight of components b), c), d), and e).

[13] The method according to any one of

[10] to

[12] , wherein the reaction system contains 30 weight percent or less of alkoxylated o-toluenediamine polyol based on the total weight of components b), c), d), and e).

[14] The method according to any one of

[10] to

[13] , wherein subatmospheric pressure is maintained in the cavity for at least step B).

[15] The method according to

[14] , wherein the subatmospheric pressure is actually 700 to 950 millibars.

Claims

1. A method for producing polyurethane foam, comprising forming a reaction system and curing the reaction system to produce the polyurethane foam, wherein the reaction system is a) At least one polyisocyanate, b) at least one polyol, c) At least one urethane catalyst, d) at least one foam-stabilizing surfactant, e) Based on the total weight of components b), c), d), and e), add 0 to 3 weight percent water, f) 2 to 3 parts by weight of cis- and / or trans-1,1,1,4,4,4-hexafluorobuto-2-ene per 100 parts by weight of components b), c), d), and e), g) comprising 12 to 20 parts by weight of one or more hydrocarbons having 4 to 6 carbon atoms per 100 parts by weight of components b), c), d), and e), The reaction system contains 25% by weight of alkoxylated o-toluenediamine polyol based on the total weight of components b), c), d), and e), The reaction system is introduced into the cavity, hardens within the cavity, and a pressure of 700 to 950 millibars is actually maintained within the cavity when the reaction system is introduced into the cavity. method.

2. A polyurethane foam produced by the method described in claim 1, When measured according to EN 12667 at an average plate temperature of 10°C, it exhibits a maximum lambda value of 18.5 mW / m-°K. Polyurethane foam.

3. The form according to claim 2, which exhibits a maximum lambda value of 18.25 mW / m-°K when measured according to EN 12667 at an average plate temperature of 10°C.

4. When measured according to ASTM 1622-88, the values ​​were 28-40 kg / m³. ３ The form according to claim 2 or 3, having the density of .

5. A method for manufacturing an insulated cabinet, A) Arranging the outer shell member and the inner liner member, and defining a cavity between them, B) Introducing the reaction system into the cavity, C) The reaction system is cured so that it expands and reacts, thereby generating a polyurethane foam that fills the cavity and adheres to the outer shell member and the inner liner member, wherein the reaction system a) At least one polyisocyanate, b) at least one polyol, c) At least one urethane catalyst, d) at least one foam-stabilizing surfactant, e) Based on the total weight of components b), c), d), and e), add 0 to 3 weight percent water, f) 2 to 3 parts by weight of cis- and / or trans-1,1,1,4,4,4-hexafluorobuto-2-ene per 100 parts by weight of components b), c), d), and e), g) comprising 12 to 20 parts by weight of one or more hydrocarbons having 4 to 6 carbon atoms per 100 parts by weight of components b), c), d), and e), The reaction system contains 25% by weight of alkoxylated o-toluenediamine polyol based on the total weight of components b), c), d), and e), A subatmospheric pressure of 700-950 millibars is actually maintained in the cavity for at least the duration of step B). method.

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