Premixed polyether, polyurethane composition, polyurethane foam, preparation method of polyurethane foam and refrigeration equipment

Abstract

The invention provides premixed polyether polyol, a polyurethane composition, polyurethane foam, a preparation method of the polyurethane foam and refrigeration equipment. The combined polyether comprises polyether polyol, a fluoride-free foaming agent and a chain extender, and the chain extender comprises 1, 2, 6-hexanetriol, 1, 10-decanediol and 1, 3, 5-cyclohexanetriol. The heat conductivity coefficient of the polyurethane foam can be reduced under the condition that the fluoride-free foaming agent is used, and the requirement for balance of fluoride-free and low heat conductivity coefficients of the polyurethane foam is met.

Description

Technical Field

[0001] This application belongs to the field of polyurethane technology, and particularly relates to a combined polyether, a polyurethane composition, a polyurethane foam, a method for preparing the same, and a refrigeration device. Background Technology

[0002] Rigid polyurethane foam possesses high strength, low thermal conductivity, and good plasticity, and is commonly used as an insulation layer in refrigeration equipment such as refrigerators and freezers. LBA (trans-1-chloro-3,3,3-trifluoropropylene), as a physical blowing agent, has a GWP (Global Warming Potential) of 3.25 and a gas-phase thermal conductivity of 9.94 mW / (m²). Adding a small amount of K can significantly reduce the thermal conductivity of polyurethane foam, thereby reducing the energy consumption of refrigeration equipment. Therefore, it is widely used in the foaming system of refrigeration equipment.

[0003] With increasing environmental awareness and stricter regulations on fluorinated gases in various countries, the refrigeration equipment industry faces the challenge of removing low thermal conductivity LBA blowing agent from polyurethane foam, which is used as insulation material. However, removing the low thermal conductivity LBA blowing agent increases the thermal conductivity of the polyurethane foam, leading to an increase in the overall energy consumption of refrigeration equipment.

[0004] Therefore, there is an urgent need to develop a fluorine-free polyurethane foam with low thermal conductivity. Summary of the Invention

[0005] This application provides a combination of polyether, a polyurethane composition, a polyurethane foam, a method for preparing the same, and a refrigeration device to solve the technical problems of existing polyurethane foams being "non-compliant with fluorine content and having high thermal conductivity without fluorine".

[0006] In a first aspect, embodiments of this application provide a composite polyether comprising a polyether polyol, a fluorine-free foaming agent, and a chain extender, wherein the chain extender comprises 1,2,6-hexanetriol, 1,10-decanediol, and 1,3,5-cyclohexanetriol.

[0007] Optionally, by mass parts, the combined polyether comprises 60 to 75 parts of the polyether polyol, 14 to 19 parts of the fluorine-free foaming agent, and 15 to 45 parts of the chain extender.

[0008] Optionally, by weight, the chain extender comprises 5 to 15 parts of 1,2,6-hexanetriol, 5 to 15 parts of 1,10-decanediol, and 5 to 15 parts of 1,3,5-cyclohexanetriol; and / or, by weight, the fluorine-free foaming agent comprises 1.8 to 2.6 parts of deionized water and 12 to 16 parts of cyclopentane.

[0009] Optionally, the polyether polyol includes polyether polyol A, polyether polyol B, and polyether polyol C, wherein the hydroxyl value of polyether polyol A is 410 mg KOH / g to 450 mg KOH / g, the hydroxyl value of polyether polyol B is 300 mg KOH / g to 350 mg KOH / g, and the hydroxyl value of polyether polyol C is 400 mg KOH / g to 500 mg KOH / g.

[0010] Optionally, by mass parts, the polyether polyol comprises 20 to 25 parts of polyether polyol A, 20 to 25 parts of polyether polyol B, and 20 to 25 parts of polyether polyol C.

[0011] Optionally, the polyether complex further includes 1 to 5 parts of catalyst by mass, wherein the catalyst includes a foaming catalyst, a gel catalyst and a trimerizing catalyst, and the mass ratio of the foaming catalyst, the gel catalyst and the trimerizing catalyst is (1~2)∶(1~2.5)∶(0.5~1).

[0012] Optionally, the foaming catalyst comprises one or more of pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, and N,N-dimethylbenzylamine; and / or, the gel catalyst comprises one or more of triethylenediamine, a gel catalyst with the designation BX011, and a gel catalyst with the designation BX6215; and / or, the trimerizing catalyst comprises one or more of 2-hydroxy-N,N,N-trimethyl-1-propylaminocarbamate and 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine.

[0013] Optionally, the polyether complex further includes 1 to 5 parts of surfactant, which includes silicone oil, by weight.

[0014] Secondly, embodiments of this application also provide a polyurethane composition comprising isocyanate and the above-described combined polyether.

[0015] Optionally, the polyurethane composition comprises, by weight, 91 to 150 parts of the combined polyether and 140 to 150 parts of the isocyanate; and / or, the NCO content of the isocyanate is 30.5% to 32.0%.

[0016] Thirdly, embodiments of this application also provide a polyurethane foam, which is obtained by foaming the above-mentioned polyurethane composition.

[0017] Optionally, the thermal conductivity of the polyurethane foam is ≤15.5 mW / (m²). K), closed-cell ratio ≥98%; and / or, the compressive strength of the polyurethane foam ≥195kPa and the density is 30.5kg / m³~32kg / m³.

[0018] Fourthly, embodiments of this application also provide a method for preparing polyurethane foam, the method comprising the following steps: S100: Provides polyether polyols, fluorine-free foaming agents and chain extenders, wherein the chain extenders include 1,2,6-hexanetriol, 1,10-decanediol and 1,3,5-cyclohexanetriol; S200: The polyether polyol, the fluorine-free foaming agent and the chain extender are mixed to obtain a combined polyether; S300: The combined polyether is mixed with isocyanate and foamed to obtain polyurethane foam.

[0019] Optionally, step S200 includes: mixing polyether polyol, fluorine-free foaming agent and chain extender, stirring at a speed of 1500 rpm to 2500 rpm for 80 s to 100 s to obtain a combined polyether; and / or, step S300 includes: mixing the combined polyether with isocyanate, stirring at a speed of 1500 rpm to 2500 rpm for 25 s to 40 s, injecting into a mold, and curing to obtain polyurethane foam.

[0020] Fifthly, embodiments of this application also provide a refrigeration device, the refrigeration device including a heat insulation layer, the heat insulation layer being made of the above-mentioned polyurethane foam, or the heat insulation layer being made of polyurethane foam prepared by the above-mentioned method for preparing polyurethane foam.

[0021] The combined polyether, polyurethane composition, polyurethane foam, and their preparation method and refrigeration equipment provided in this application embodiment utilize chain extenders such as 1,2,6-hexanetriol, 1,10-decanediol, and 1,3,5-cyclohexanetriol in combination with a fluorine-free blowing agent. Specifically, 1,2,6-hexanetriol introduces a 6-carbon suspended chain into the polyurethane foam, 1,10-decanediol introduces a 10-carbon suspended chain, and 1,3,5-cyclohexanetriol introduces a 6-carbon cyclic suspended chain. These suspended chains possess steric hindrance effects and polar groups. The dilution effect improves the compatibility of the soft and hard segments of polyurethane, thereby avoiding the formation of continuous high heat conduction paths and reducing differences in heat transfer efficiency and interfacial thermal resistance. At the same time, these suspension chains can also enable polyurethane foam to maintain a high closed-cell ratio and optimize cell size. This allows for a reduction in the thermal conductivity of polyurethane foam when using fluorine-free blowing agents, that is, achieving low thermal conductivity of polyurethane foam in a fluorine-free system. This meets the need for a balance between fluorine-free and low thermal conductivity in polyurethane foam, and solves the technical problem of existing polyurethane foams being "non-compliant with fluorine content and having high thermal conductivity when fluorine-free". Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of this application. Those skilled in the art can obtain other drawings based on these drawings without creative effort. In the following description, the same reference numerals denote the same parts.

[0023] Figure 1 This is a flowchart illustrating the preparation method of polyurethane foam provided in an embodiment of this application. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0025] In the description of this application, the term "comprising" means "including but not limited to". The term "exemplary" is used to mean "serving as an example, illustration, or illustration", and any embodiment described as "exemplary" is not necessarily to be construed as being more preferred or advantageous than other embodiments. The term "and / or" includes any and all combinations of one or more of the associated listed items. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features.

[0026] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, which applies regardless of the range.

[0027] This application provides a composite polyether comprising a polyether polyol, a fluorine-free blowing agent, and a chain extender. The chain extender comprises 1,2,6-hexanetriol (HTO), 1,10-decanediol (DDO), and 1,3,5-cyclohexanetriol (CTO).

[0028] The combined polyethers provided in this application embodiment utilize chain extenders such as 1,2,6-hexanetriol, 1,10-decanediol, and 1,3,5-cyclohexanetriol in combination with a fluorine-free blowing agent. Specifically, 1,2,6-hexanetriol introduces 6-carbon suspended chains into the polyurethane foam, 1,10-decanediol introduces 10-carbon suspended chains, and 1,3,5-cyclohexanetriol introduces 6-carbon cyclic suspended chains. These suspended chains exhibit steric hindrance and polar group dilution effects, and can improve the soft and hard segment phases of the polyurethane. The suspension chains are compatible, thus avoiding the formation of continuous high heat conduction paths and reducing differences in heat transfer efficiency and interfacial thermal resistance. At the same time, these suspension chains can also maintain a high closed-cell ratio and optimize cell size in polyurethane foam. This enables the reduction of the thermal conductivity of polyurethane foam when using fluorine-free blowing agents. In other words, it achieves low thermal conductivity of polyurethane foam in a fluorine-free system (without using fluorine-containing blowing agents), meeting the need for a balance between fluorine-free and low thermal conductivity in polyurethane foam, and solving the technical problem of existing polyurethane foams being "non-compliant with fluorine content and having high thermal conductivity when fluorine-free".

[0029] Understandably, the core mechanism by which this application achieves low thermal conductivity in a fluorine-free system through the construction of carbon atom suspended chains using HTO, DDO, and CTO with multi-carbon atom structures stems from a three-tiered synergistic effect of "molecular chain regulation - microstructure optimization - macroscopic performance enhancement," as detailed below: 1. At the molecular chain level, the suspension chain has the following three regulatory effects: (1) Steric hindrance effect: The 6-carbon long chain suspension chain introduced by HTO, the 10-carbon long chain suspension chain introduced by DDO and the 6-carbon cyclic suspension chain introduced by CTO, and the polyhydroxyl groups contained in HTO, DDO and CTO as suspension chains, these suspension chains can hinder the micro-region aggregation of polyurethane hard segments (i.e. the reaction products of isocyanate and chain extender) and avoid the formation of continuous "high thermal conductivity pathways"; (2) Polar group dilution effect: The suspension chain can disperse the strong polar groups (such as urethane groups) in the polyurethane hard segments, reduce the density of intermolecular hydrogen bonds (hydrogen bonds will enhance intermolecular thermal conductivity), and reduce the heat transfer efficiency after dilution; (3) Improvement of polyurethane soft and hard segment compatibility: The suspension chain can optimize the interface bonding between the soft segment (polyether polyol) and the hard segment, reduce the interface thermal resistance difference, and avoid the local thermal conductivity enhancement caused by interface defects. 2. At the microstructure level, precise control of cell structure: (1) Maintaining closed cell rate: Since the long carbon chain (non-polar) of the suspension chain will dilute the polar group density of the polyurethane hard segment and destroy the local hydrogen bond aggregation, the reaction of -NCO and -OH will change from "local concentrated rapid reaction" to "uniform and slow reaction". The gel rate will not change abruptly. Thus, the suspension chain can regulate the foaming reaction rate and the gel rate to match, so that the closed cell rate of polyurethane foam is ≥98%. The closed cell structure can reduce gas convection heat transfer (convective heat transfer is one of the main ways of heat loss of porous materials); (2) Optimizing cell size: The suspension chain can regulate the viscosity of the system and optimize the nucleation environment, creating a prerequisite for the surfactant to accurately play the "bubble stabilizing role". Through the synergistic effect of the suspension chain and the surfactant, the geometric mean diameter of the cell can be controlled at 100μm~150μm. This size can reduce radiative heat transfer, while the pore size of polyurethane foam using LBA foaming agent is 200μm~250μm.

[0030] 3. Macroscopic performance level: There is no need to use fluorinated blowing agents such as LBA. Instead, multi-carbon chain extenders such as HTO, DDO, and CTO are used in combination with fluorine-free blowing agents. Through the dual regulation of the suspended chain constructed by the fluorine-free blowing agent and the multi-carbon chain extender, the thermal conductivity of polyurethane foam can be reduced, achieving a balance between fluorine-free and low thermal conductivity. This meets the requirements of fluorine-free and low thermal conductivity balance for the insulation layer of refrigeration equipment such as refrigerators and freezers.

[0031] Furthermore, this application utilizes carbon atom suspended chains constructed by introducing chain extenders such as 1,2,6-hexanetriol, 1,10-decanediol, and 1,3,5-cyclohexanetriol. These chains optimize the crosslinking network of polyurethane foam, increasing its compressive strength to 195 kPa. This strength is sufficient to withstand the weight of refrigeration equipment like refrigerators and the impact of external forces during transportation, thus meeting structural support requirements. Specifically, the suspended chains, by regulating the distribution of crosslinking points, suppressing the aggregation of hard polyurethane segments, and optimizing network toughness, transform the traditional "locally dense, overall uneven" crosslinking network of polyurethane foam into an optimized structure that is "uniform, dense, and combining rigidity and flexibility." This allows for uniform stress transmission under load, thereby improving the overall strength of the polyurethane foam.

[0032] In some embodiments of this application, the combined polyether comprises, by weight parts, 60 to 75 parts of the polyether polyol, 14 to 19 parts of the fluorine-free blowing agent, and 15 to 45 parts of the chain extender. By controlling the amount of each component of the combined polyether within the above range, the polyurethane foam prepared using the combined polyether of this application can possess environmental friendliness, good thermal insulation, and good mechanical properties.

[0033] For example, the mass fraction of the polyether polyol can be 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, or any range between any two of the aforementioned values; the mass fraction of the fluorine-free foaming agent can be 14 parts, 14.5 parts, 15 parts, 15.5 parts, 16 parts, 16.5 parts, 17 parts, 17.5 parts, 18 parts, 18.5 parts, 19 parts, or any range between any two of the aforementioned values; the mass fraction of the chain extender can be 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, or any range between any two of the aforementioned values.

[0034] In some embodiments of this application, the chain extender comprises, by weight parts, 5 to 15 parts of 1,2,6-hexanetriol, 5 to 15 parts of 1,10-decanediol, and 5 to 15 parts of 1,3,5-cyclohexanetriol. This configuration allows the polyurethane foam to control the molecular weight and length of the suspended chain carbon by adjusting the proportions of 1,2,6-hexanetriol, 1,10-decanediol, and 1,3,5-cyclohexanetriol, thereby improving the flexibility and adaptability of the technology.

[0035] For example, the mass fractions of 1,2,6-hexanetriol can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, or any range between any two of the aforementioned values; the mass fractions of 1,10-decanediol can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, or any range between any two of the aforementioned values; the mass fractions of 1,3,5-cyclohexanetriol can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, or any range between any two of the aforementioned values.

[0036] In some embodiments of this application, the fluorine-free blowing agent comprises, by weight, 1.8 to 2.6 parts deionized water and 12 to 16 parts cyclopentane. Deionized water serves as a chemical blowing agent, replacing the fluorine-containing physical blowing agent, and generates CO2 to help adjust the cell density and balance the thermal conductivity and strength of the polyurethane foam; cyclopentane is used as a physical blowing agent. This application improves the environmental friendliness of polyurethane by using fluorine-free blowing agents such as deionized water and cyclopentane; through the dual regulation of the suspended chain constructed by the chemical blowing agent and the multi-carbon chain extender, the thermal conductivity of the polyurethane foam can be reduced to as low as 15.5 mW / (m²). K), achieving a balance between fluorine-free and low thermal conductivity.

[0037] For example, the mass fraction of the deionized water can be 1.8 parts, 1.9 parts, 2.0 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, or any range between any two of the aforementioned values; the mass fraction of the cyclopentane can be 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, or any range between any two of the aforementioned values.

[0038] In some embodiments of this application, the polyether polyol includes polyether polyol A, polyether polyol B, and polyether polyol C, wherein the hydroxyl value of polyether polyol A is 410 mg KOH / g to 450 mg KOH / g, the hydroxyl value of polyether polyol B is 300 mg KOH / g to 350 mg KOH / g, and the hydroxyl value of polyether polyol C is 400 mg KOH / g to 500 mg KOH / g.

[0039] Among them, high-hydroxyl-value polyether polyol A provides high reactivity, rapidly forming a large number of microbubble nuclei and laying the foundation for dense pores; medium- to low-hydroxyl-value polyether polyol B reduces the overall reaction rate of the system, extends the bubble growth window, and prevents pore collapse and merging; high-hydroxyl-value polyether polyol C synergistically constructs a dense cross-linked network with polyether polyol A, improving the structural rigidity and closed-cell integrity of polyurethane foam. This application, by using the above-mentioned polyether polyols A, B, and C in a compound, can achieve the control of reaction kinetic gradients and optimize the pore structure, thereby comprehensively improving the thermal insulation performance, mechanical strength, and dimensional stability of polyurethane foam.

[0040] For example, the hydroxyl value of the polyether polyol A can be 410 mg KOH / g, 420 mg KOH / g, 430 mg KOH / g, 440 mg KOH / g, 450 mg KOH / g, or any range between two of the aforementioned values; the hydroxyl value of the polyether polyol B can be 300 mg KOH / g, 310 mg KOH / g, 320 mg KOH / g, 330 mg KOH / g, 340 mg KOH / g, 350 mg KOH / g, or any range between two of the aforementioned values. g or a range between any two of the aforementioned values; the hydroxyl value of the polyether polyol C can be 400 mg KOH / g, 410 mg KOH / g, 420 mg KOH / g, 430 mg KOH / g, 440 mg KOH / g, 450 mg KOH / g, 460 mg KOH / g, 470 mg KOH / g, 480 mg KOH / g, 490 mg KOH / g, 500 mg KOH / g or a range between any two of the aforementioned values.

[0041] Optionally, the polyether polyol A has a functionality of 4 to 6, a density of 1.00 g / cm³ to 1.20 g / cm³, and a viscosity of 2000 mPa·s to 3000 mPa·s at 25°C. As a high-functionality polyol, the polyether polyol A enables the polyurethane foam to produce sufficient crosslinking and rigidity. For example, the functionality of the polyether polyol A can be 4, 4.5, 5.5, 6, or any two of the aforementioned values; the density of the polyether polyol A can be 1.00 g / cm³, 1.05 g / cm³, 1.10 g / cm³, 1.15 g / cm³, 1.20 g / cm³, or any two of the aforementioned values; and the viscosity of the polyether polyol A at 25°C can be 2000 mPa·s, 2200 mPa·s, 2500 mPa·s, 2800 mPa·s, 3000 mPa·s, or any two of the aforementioned values.

[0042] Optionally, the polyether polyol B has a functionality of 3-4, a density of 0.95 g / cm³-1.15 g / cm³, and a viscosity of 1000 mPa·s-2000 mPa·s at 25°C. As a low-functionality polyol, the polyether polyol B has low viscosity and good flowability, ensuring the basic structure of the polyurethane foam. For example, the functionality of the polyether polyol B can be 3, 3.5, 4, or any two of the aforementioned values; the density of the polyether polyol B can be 0.95 g / cm³, 1.05 g / cm³, 1.15 g / cm³, or any two of the aforementioned values; and the viscosity of the polyether polyol B at 25°C can be 1000 mPa·s, 1200 mPa·s, 1500 mPa·s, 1700 mPa·s, 2000 mPa·s, or any two of the aforementioned values.

[0043] Optionally, the polyether polyol C has a functionality of 4-8, a density of 1.05 g / cm³-1.25 g / cm³, and a viscosity of 6000 mPa·s-8000 mPa·s at 25°C. As a high-functionality polyol, the polyether polyol C enables the polyurethane foam to achieve sufficient crosslinking and rigidity. For example, the functionality of the polyether polyol C can be 4, 5, 6, 7, 8, or any two of the aforementioned values; the density of the polyether polyol C can be 1.05 g / cm³, 1.15 g / cm³, 1.25 g / cm³, or any two of the aforementioned values; and the viscosity of the polyether polyol C at 25°C can be 6000 mPa·s, 6500 mPa·s, 7000 mPa·s, 7500 mPa·s, 8000 mPa·s, or any two of the aforementioned values.

[0044] In some embodiments of this application, the polyether polyol comprises, by weight, 20-25 parts of polyether polyol A, 20-25 parts of polyether polyol B, and 20-25 parts of polyether polyol C. By controlling the amounts of polyether polyol A, polyether polyol B, and polyether polyol C within the aforementioned range, this application enables the polyurethane foam to achieve a balance of good thermal insulation performance, mechanical strength, and dimensional stability.

[0045] For example, the mass fraction of polyether polyol A can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, or any range between any two of the aforementioned values; the mass fraction of polyether polyol B can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, or any range between any two of the aforementioned values; the mass fraction of polyether polyol C can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, or any range between any two of the aforementioned values.

[0046] In some embodiments of this application, the combined polyether further includes 1 to 5 parts of catalyst by weight. The catalyst includes a foaming catalyst, a gelling catalyst, and a trimerizing catalyst, and the mass ratio of the foaming catalyst, the gelling catalyst, and the trimerizing catalyst is (1~2):(1~2.5):(0.5~1). By employing the above-mentioned catalyst, this application helps to control the reaction rate, reduce the thermal conductivity of the polyurethane foam, and ensure good mechanical properties.

[0047] For example, the mass fraction of the catalyst can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, or any range between any two of the aforementioned values; the mass ratio of the foaming catalyst, the gel catalyst, and the trimerizing catalyst can be 1:1:0.5, 1:1:1, 1:2.5:0.5, 1:2.5:1, 2:1:0.5, 2:1:1, 2:2.5:0.5, 2:2.5:1, 1.5:1.8:0.7, or any range between any two of the aforementioned ratios.

[0048] Optionally, the foaming catalyst may include one or more of pentamethyldiethylenetriamine (PC-5), pentamethyldipropylenetriamine (PC-77), and N,N-dimethylbenzylamine (BDMA). Optionally, the gel catalyst may include one or more of triethylenediamine, a gel catalyst with the designation BX011, and a gel catalyst with the designation BX6215. Optionally, the trimerizing catalyst may include one or more of 2-hydroxy-N,N,N-trimethyl-1-propylaminocarbamate (TMR-2) and 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine (PC-41).

[0049] In some embodiments of this application, the combined polyether further includes 1 to 5 parts by weight of a surfactant, wherein the surfactant includes silicone oil. By using silicone oil as a surfactant, this application can stabilize the cell structure and prevent cell breakage / coalescence, thus giving the polyurethane foam good mechanical properties. Optionally, the silicone oil may be selected from one or more of silicone oils with the designation UR5960, UR-5981, and UR-5961.

[0050] Understandably, through the synergistic effect of the suspension chain and the surfactant, the geometric mean diameter of the foam cells can be controlled within 100μm~150μm. This size reduces radiative heat transfer, thereby helping to lower the thermal conductivity of polyurethane foam. Specifically, the suspension chain creates the conditions for the surfactant to accurately exert its "bubble stabilizing effect" by regulating the system viscosity and optimizing the nucleation environment; the surfactant locks in small-sized cells by reducing interfacial tension and preventing bubble coalescence; the two work together to achieve "multiple nucleation, slow growth, and no coalescence" of bubbles, ultimately controlling the cell diameter to 100μm~150μm, which is smaller than the cell size (200μm~250μm) of polyurethane foam using LBA blowing agent.

[0051] For example, the mass fraction of the surfactant can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, or any range between any two of the aforementioned values; the silicone oil can be selected from one or more of silicone oil with brand name UR5960, silicone oil with brand name UR-5981, and silicone oil with brand name UR-5961.

[0052] This application also provides a polyurethane composition comprising a combined polyether and an isocyanate, wherein the specific structure of the combined polyether is as described in the above embodiments. Since the polyurethane composition employs all the technical solutions of the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0053] In some embodiments of this application, the polyurethane composition comprises, by weight, 91 to 150 parts of the combined polyether and 140 to 150 parts of the isocyanate. By controlling the amount of each component of the polyurethane composition within the above range, the polyurethane foam prepared using the polyurethane composition of this application can possess environmental friendliness, good thermal insulation, and good mechanical properties.

[0054] For example, the mass fraction of the polyether combination can be 91 parts, 95 parts, 100 parts, 105 parts, 110 parts, 115 parts, 120 parts, 125 parts, 130 parts, 140 parts, 145 parts, 150 parts, or any range between any two of the aforementioned values; the mass fraction of the isocyanate can be 140 parts, 141 parts, 142 parts, 143 parts, 144 parts, 145 parts, 146 parts, 147 parts, 148 parts, 149 parts, 150 parts, or any range between any two of the aforementioned values.

[0055] Optionally, the density of the isocyanate is 1.22 g / cm³ to 1.25 g / cm³, and the NCO content of the isocyanate is 30.5% to 32.0%. For example, the density of the isocyanate can be 1.22 g / cm³, 1.23 g / cm³, 1.24 g / cm³, 1.25 g / cm³, or any range between two of the aforementioned values; the NCO content of the isocyanate can be 30.5%, 30.7%, 31.0%, 31.2%, 31.5%, 31.8%, 32.0%, or any range between two of the aforementioned values.

[0056] Optionally, the isocyanate may include one or more of polymethylene polyphenyl isocyanate (PAPI), diphenylmethane diisocyanate (MDI), polymeric diphenylmethane diisocyanate (polymeric MDI), isophorone diisocyanate (IPDI), and toluene diisocyanate (TDI).

[0057] This application also provides a polyurethane foam, which is obtained by foaming the above-described polyurethane composition. Since this polyurethane foam adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0058] Optionally, the thermal conductivity of the polyurethane foam is ≤15.5 mW / (m²). K), wherein the thermal conductivity of the polyurethane foam has a closed-cell ratio ≥98%, for example, the closed-cell ratio can be 98%, 98.5%, 99%, 99.5%, 100%, or any range between the aforementioned two values.

[0059] Optionally, the compressive strength of the polyurethane foam is ≥195 kPa; the density of the polyurethane foam is 30.5 kg / m³ to 32 kg / m³, for example, it can be 30.5 kg / m³, 30.6 kg / m³, 30.7 kg / m³, 30.8 kg / m³, 30.9 kg / m³, 31.0 kg / m³, 31.1 kg / m³, 31.2 kg / m³, 31.3 kg / m³, 31.4 kg / m³, 31.5 kg / m³, 31.6 kg / m³, 31.7 kg / m³, 31.8 kg / m³, 31.9 kg / m³, 32 kg / m³, or any range between the aforementioned two values.

[0060] This application also provides a method for preparing polyurethane foam, which can be used to prepare the above-mentioned polyurethane foam. For example... Figure 1 As shown, the method for preparing the polyurethane foam includes the following steps: S100: Provides polyether polyols, fluorine-free foaming agents and chain extenders, including 1,2,6-hexanetriol, 1,10-decanediol and 1,3,5-cyclohexanetriol; S200: A composite polyether is obtained by mixing polyether polyol, fluorine-free foaming agent and chain extender; S300: Polyurethane foam is obtained by mixing polyether with isocyanate and then foaming.

[0061] The polyurethane foam preparation method provided in this application, by completely removing fluorinated foaming agents such as LBA, can reduce the thermal conductivity and increase the compressive strength of the polyurethane foam, thus achieving a combination of environmental compliance, excellent thermal insulation and structural support.

[0062] In some embodiments of this application, step S200 includes: mixing polyether polyol, fluorine-free foaming agent and chain extender, and stirring at a speed of 1500 rpm to 2500 rpm (e.g., 1500 rpm, 2000 rpm or 2500 rpm, etc.) for 80 s to 100 s (e.g., 80 s, 90 s or 100 s, etc.) to obtain combined polyether.

[0063] Optionally, step S200 may include: adding polyether polyol, fluorine-free foaming agent, chain extender, catalyst and surfactant into a stirred tank and stirring at a speed of 1500rpm~2500rpm for 80s~100s to obtain a combined polyether.

[0064] In some embodiments of this application, step S300 includes: mixing the combined polyether with isocyanate, stirring at a speed of 1500 rpm to 2500 rpm (e.g., 1500 rpm, 2000 rpm, or 2500 rpm) for 25 s to 40 s (e.g., 25 s, 30 s, 35 s, or 40 s), and then injecting the mixture into a mold and curing it to obtain polyurethane foam.

[0065] Optionally, step S300 may include: rapidly adding isocyanate to the polyether mixture and stirring at 1500 rpm to 2500 rpm for 25 to 40 seconds to obtain a mixture; injecting the mixture into a mold and allowing it to foam freely at 23°C to 28°C; demolding after cooling to 23°C to 28°C; and then curing at 23°C to 28°C to obtain polyurethane foam.

[0066] This application also provides a refrigeration device, which includes an insulation layer made of polyurethane foam. The specific structure of the polyurethane foam is described in the above embodiments. The refrigeration device provided in this application, by using the aforementioned polyurethane foam as the insulation layer, can improve insulation performance, thereby reducing overall energy consumption. Furthermore, it is fluorine-free and more environmentally friendly.

[0067] Since this refrigeration equipment adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0068] Optionally, the refrigeration equipment can be a refrigerator, freezer, biological sample transport box, or cold chain container, etc. Taking a refrigerator as an example, the insulation layer can be applied to the side walls of the refrigerator body, the inner lining of the drawers, the partition layer, and the foam layer of the door.

[0069] The technical solutions and effects of this application will be described in detail below through specific embodiments and comparative examples. The following embodiments are only some embodiments of this application and are not intended to limit this application.

[0070] Raw material preparation: Polyether polyol A: hydroxyl value of 430 mg KOH / g, density of 1.10 cm³, viscosity of 3000 mPa·s at 25℃, purchased from Shandong Dongda Chemical Co., Ltd., product brand name NT-430W.

[0071] Polyether polyol B: hydroxyl value of 325 mg KOH / g, density of 1.05 cm³, viscosity of 1500 mPa·s at 25℃, purchased from Nanjing Hongbaoli Company, product brand H6437.

[0072] Polyether polyol C: hydroxyl value of 450 mg KOH / g, density of 1.15 cm³, viscosity of 6000 mPa·s at 25℃, purchased from Nanjing Hongbaoli Company, product brand name GR8231.

[0073] Chain extender A: 1,2,6-hexanetriol (analytical grade), purchased from Rongsheng New Material Technology (Nantong, Jiangsu) Co., Ltd.

[0074] Chain extender B: 1,10-decanediol (analytical grade), purchased from Hubei Watson Chemical Technology Co., Ltd.

[0075] Chain extender C: 1,3,5-cyclohexanetriol (analytical grade), purchased from Hubei Shixing Chemical Co., Ltd.

[0076] Fluorine-free foaming agent: includes deionized water and cyclopentane. The deionized water is prepared by conventional methods, and the cyclopentane is purchased from Shandong Xuchen Chemical Co., Ltd., CAS No. 287-92-3.

[0077] Catalyst: It is a mixture of pentamethyldiethylenetriamine (PC-5), gel catalyst and 2-hydroxy-N,N,N-trimethyl-1-propylamine carbamate (TMR-2) in a mass ratio of 1.5:1.8:0.8; wherein PC-5 was purchased from Evonik, TMR-2 was purchased from Newtech Chemicals, and the gel catalyst was purchased from Jiahe Chemicals, brand name BX011.

[0078] Surfactant; silicone oil, purchased from Jiangsu Ausjia Materials Technology Co., Ltd., grade UR5960.

[0079] Isocyanate: Polymeric diphenylmethane diisocyanate (polymeric MDI), with an NCO content of 31.5%, purchased from Wanhua Chemical Company, brand name PM-200.

[0080] Example 1 Example 1 provides a polyurethane foam, the preparation method of which includes the following steps: (1) Add polyether polyol A, polyether polyol B, polyether polyol C, chain extender A, chain extender B, chain extender C, deionized water, cyclopentane, silicone oil and catalyst into a stirred tank and stir at 2000 rpm for 80 s to obtain a uniform polyether combination. (2) Add the polymeric MDI to the polyether mixture quickly and stir at 2000 rpm for 25 seconds to form a mixture; (3) The mixture is injected into a mold (1100 mm high, 300 mm long, 50 mm wide, and 20 mm thick), and allowed to foam freely at room temperature (25°C). After cooling to room temperature, the mixture is demolded and then cured at room temperature to obtain polyurethane foam.

[0081] Example 2 Example 2 is basically the same as Example 1, except that the amount of some components used in Example 2 is different from that in Example 1.

[0082] Example 3 Example 3 is basically the same as Example 1, except that the amount of some components used in Example 3 is different from that in Example 1.

[0083] Example 4 Example 4 is basically the same as Example 1, except that the amount of some components used in Example 4 is different from that in Example 1.

[0084] Example 5 Example 5 is basically the same as Example 1, except that the amount of some components used in Example 5 is different from that in Example 1.

[0085] Comparative Example 1 Comparative Example 1 is basically the same as Example 1, with the main difference being that chain extender A, chain extender B and chain extender C were not added in Comparative Example 1, and LBA (i.e. trans-1-chloro-3,3,3-trifluoropropene) was used to replace part of the cyclopentane in Example 1 in Comparative Example 1.

[0086] The amounts (parts by mass) of each component in Examples 1-5 and Comparative Example 1 are shown in Table 1 below.

[0087] Table 1

[0088] The polyurethane foams of Examples 1-5 and Comparative Example 1 were subjected to performance tests, and the test results are detailed in Table 2 below. The performance test items included: thermal conductivity at 10℃, closed-cell ratio, compressive strength, core density, and environmental friendliness.

[0089] The testing methods for each performance aspect are as follows: Thermal conductivity at 10℃: measured using an EKOHC-074-200 thermal conductivity meter at an average temperature of 10℃ (2℃ for the upper plate and 18℃ for the lower plate) in accordance with ISO 12939-01 / DIN 52612; specifically, the foam sample was cut from the center of the molded part 24 hours after the polyurethane foam was prepared, and the foam sample was measured immediately after cutting.

[0090] Closed-cell rate: The closed-cell rate of polyurethane foam was determined according to the requirements of GB / T 26689-2024 "Rigid polyurethane foam for refrigerators and freezers" and the method in GBT 10799-2008.

[0091] Compressive strength: measured according to DIN 53421-06-84 using Shimadzu AGS-J(500N)5.

[0092] Core density: The core density of polyurethane foam was determined by the water displacement method according to GB / T6343-2009. Environmental friendliness: In accordance with HJ 1057-2019, gas chromatography-mass spectrometry was used to determine whether polyurethane foam contained fluorine.

[0093] Table 2

[0094] As shown in Table 2: The thermal conductivity of the polyurethane foams (using chain extenders and fluorine-free blowing agents) in Examples 1-5 at 10°C is 15.3 mW / (m²). K)~15.5mW / (m The thermal conductivity (K) of the polyurethane foam in Comparative Example 1 (using a fluorinated blowing agent) at 10°C is lower than that of the polyurethane foam in Comparative Example 1 (17.5 mW / (m²)). The closed-cell ratios of polyurethane foams in Examples 1-5 (98.7%-98.9%) were all greater than those in Comparative Example 1 (95%). Furthermore, the polyurethane foams in Examples 1-5 were fluorine-free, while the polyurethane foam in Comparative Example 1 contained fluorine. This indicates that Examples 1-5, without using LBA low thermal conductivity blowing agent, could effectively reduce the thermal conductivity of polyurethane foam by using a chain extender in combination with a fluorine-free blowing agent, while simultaneously improving the environmental friendliness of the polyurethane foam, achieving a balance between fluorine-free and low thermal conductivity.

[0095] The core density of the polyurethane foams in Examples 1-5 (30.5 kg / m³ to 31.5 kg / m³) was lower than that of the polyurethane foam in Comparative Example 1 (33 kg / m³). However, the compressive strength of the polyurethane foams in Examples 1-5 (195 kPa to 199 kPa) was higher than that of the polyurethane foam in Comparative Example 1 (175 kPa). This indicates that the suspended chains constructed by introducing chain extenders such as HTO, DDO, and CTO in Examples 1-5 can effectively optimize the crosslinking network of polyurethane foam, thereby improving the compressive strength of polyurethane foam.

[0096] In summary, this application has, but is not limited to, the following advantages: (1) Environmental compliance: The polyurethane foam completely removes fluorinated foaming agents such as LBA and no fluorinated compounds are detected. It complies with the EU F-GAS regulations on banning fluorinated greenhouse gases in refrigerators and freezers from 2026 and is in line with global environmental control trends. (2) Excellent thermal insulation performance: The thermal conductivity of polyurethane foam is as low as 15.5 mW / (m The thermal conductivity (K) is much lower than that of traditional polyurethane foam using LBA blowing agent (17.5 mW / (m²)). K)) to improve thermal insulation performance while ensuring environmental friendliness; (3) Strong process adaptability: The preparation process is compatible with the existing high-pressure foaming process of polyurethane foam production, and no modification of production equipment is required. It can be directly applied on a large scale. (4) Cost controllable: The raw materials used (such as chain extenders) are industrial-grade conventional reagents, and the cost of raw materials is controllable.

[0097] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0098] The above provides a detailed description of the combined polyether, polyurethane composition, polyurethane foam, preparation method, and refrigeration equipment provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A composite polyether, characterized in that, It includes polyether polyol, fluorine-free foaming agent and chain extender, wherein the chain extender includes 1,2,6-hexanetriol, 1,10-decanediol and 1,3,5-cyclohexanetriol.

2. The composite polyether according to claim 1, characterized in that, By weight, the polyether composition comprises 60 to 75 parts of the polyether polyol, 14 to 19 parts of the fluorine-free foaming agent, and 15 to 45 parts of the chain extender.

3. The composite polyether according to claim 1, characterized in that, The chain extender comprises, by mass parts, 5 to 15 parts of 1,2,6-hexanetriol, 5 to 15 parts of 1,10-decanediol and 5 to 15 parts of 1,3,5-cyclohexanetriol; And / or, by mass parts, the fluorine-free foaming agent comprises 1.8 to 2.6 parts of deionized water and 12 to 16 parts of cyclopentane.

4. The composite polyether according to claim 1, characterized in that, The polyether polyols include polyether polyol A, polyether polyol B, and polyether polyol C. The hydroxyl value of polyether polyol A is 410 mg KOH / g to 450 mg KOH / g, the hydroxyl value of polyether polyol B is 300 mg KOH / g to 350 mg KOH / g, and the hydroxyl value of polyether polyol C is 400 mg KOH / g to 500 mg KOH / g.

5. The composite polyether according to claim 4, characterized in that, Based on parts by weight, the polyether polyol comprises 20 to 25 parts of polyether polyol A, 20 to 25 parts of polyether polyol B, and 20 to 25 parts of polyether polyol C.

6. The combined polyether according to any one of claims 1 to 5, characterized in that, The polyether complex further includes 1 to 5 parts of catalyst by mass; the catalyst includes a foaming catalyst, a gel catalyst and a trimerizing catalyst, and the mass ratio of the foaming catalyst, the gel catalyst and the trimerizing catalyst is (1~2)∶(1~2.5)∶(0.5~1).

7. The composite polyether according to claim 6, characterized in that, The foaming catalyst includes one or more of pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, and N,N-dimethylbenzylamine; And / or, the gel catalyst includes one or more of triethylenediamine, a gel catalyst with the designation BX011, and a gel catalyst with the designation BX6215; And / or, the trimerizing catalyst comprises one or more of 2-hydroxy-N,N,N-trimethyl-1-propylaminocarbamate and 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine.

8. The combined polyether according to any one of claims 1 to 5, characterized in that, The polyether complex further includes 1 to 5 parts of surfactant by weight, wherein the surfactant includes silicone oil.

9. A polyurethane composition, characterized in that, It includes isocyanates and the polyether combinations according to any one of claims 1 to 8.

10. The polyurethane composition according to claim 9, characterized in that, The polyurethane composition comprises, by weight parts, 91 to 150 parts of the combined polyether and 140 to 150 parts of the isocyanate; And / or, the NCO content of the isocyanate is 30.5%~32.0%.

11. A polyurethane foam, characterized in that, The polyurethane foam is obtained by foaming the polyurethane composition according to any one of claims 9 to 10.

12. The polyurethane foam according to claim 11, characterized in that, The thermal conductivity of the polyurethane foam is ≤15.5 mW / (m K), closed-cell ratio ≥98%; And / or, the polyurethane foam has a compressive strength ≥195kPa and a density of 30.5kg / m³~32kg / m³.

13. A method for preparing polyurethane foam, characterized in that, Includes the following steps: S100: Provides polyether polyols, fluorine-free foaming agents and chain extenders, wherein the chain extenders include 1,2,6-hexanetriol, 1,10-decanediol and 1,3,5-cyclohexanetriol; S200: The polyether polyol, the fluorine-free foaming agent and the chain extender are mixed to obtain a combined polyether; S300: The combined polyether is mixed with isocyanate and foamed to obtain polyurethane foam.

14. The method for preparing polyurethane foam according to claim 13, characterized in that, Step S200 includes: mixing polyether polyol, fluorine-free foaming agent and chain extender, and stirring at a speed of 1500rpm~2500rpm for 80s~100s to obtain combined polyether; And / or, step S300 includes: mixing the combined polyether with isocyanate, stirring at a speed of 1500 rpm to 2500 rpm for 25 s to 40 s, injecting into a mold, and curing to obtain polyurethane foam.

15. A refrigeration device, characterized in that, The refrigeration equipment includes an insulation layer, which is made of polyurethane foam as described in any one of claims 11-12, or the insulation layer is made of polyurethane foam prepared by the method described in any one of claims 13-14.

Images