Foaming agent composition, polyurethane composition, polyurethane foam and refrigeration equipment

Abstract

The invention provides a foaming agent composition, a polyurethane composition, polyurethane foam and refrigeration equipment. The foaming agent composition is prepared from the following components in parts by mass: 5 to 15 parts of trans-1, 1, 3, 4-tetrafluorobutene, 8 to 15 parts of cyclopentane, 1 to 3 parts of 1, 1-difluoroethane and 1.0 to 2.5 parts of silane modified starch. The environment-friendly property of the polyurethane foam can be improved.

Description

Technical Field

[0001] This application belongs to the field of polyurethane technology, and particularly relates to a foaming agent composition, a polyurethane composition, a polyurethane foam, and a refrigeration device. Background Technology

[0002] Currently, polyurethane foam is commonly used for insulation layers in refrigeration equipment. However, the blowing agents for existing polyurethane foams mostly rely on high GWP (Global Warming Potential) substances such as HFC-245fa (GWP=1030) and HFC-134a (GWP=1430). Moreover, the foam stabilizers are mostly siloxanes containing PFAS (per- and polyfluoroalkyl substances), which pose environmental residue risks and are difficult to meet environmental regulations. Summary of the Invention

[0003] This application provides a foaming agent composition, a polyurethane composition, a polyurethane foam, and a refrigeration device to solve the problem that existing foaming agent compositions are difficult to meet environmental regulations.

[0004] In a first aspect, embodiments of this application provide a foaming agent composition, which, by mass parts, comprises 5 to 15 parts of trans-1,1,3,4-tetrafluorobutene, 8 to 15 parts of cyclopentane, 1 to 3 parts of 1,1-difluoroethane, and 1.0 to 2.5 parts of silane-modified starch.

[0005] Optionally, the silane-modified starch is prepared by grafting starch and a first silane at a mass ratio of 9:1 to 11:1, with a grafting rate of 8% to 25%.

[0006] Optionally, the first silane includes one or more of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

[0007] Secondly, embodiments of this application provide a polyurethane composition comprising a polyol composition, an isocyanate, and the aforementioned foaming agent composition.

[0008] Optionally, the polyurethane composition comprises, by weight, 100 parts of the polyol composition, 15 to 33 parts of the foaming agent composition, and 120 to 150 parts of the isocyanate.

[0009] Optionally, by mass parts, the polyol composition comprises 20 to 35 parts of pentaerythritol branched polyether, 15 to 30 parts of toluene diamine polyether, 25 to 40 parts of sucrose polyether, and 5 to 15 parts of phthalic anhydride polyester polyol.

[0010] Optionally, the polyurethane composition further includes 0.5 to 2.0 parts by weight of modified nano-calcium carbonate, wherein the modified nano-calcium carbonate is nano-calcium carbonate with a second silane modified on its surface.

[0011] Optionally, the second silane has a mass fraction of 1.0% to 3.0% in the modified nano-calcium carbonate; and / or, the second silane includes one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane; and / or, the modified nano-calcium carbonate has a particle size of 50 nm to 100 nm. Optionally, by weight, the polyurethane composition further comprises 1.4 to 3.2 parts of a composite catalyst, wherein the composite catalyst comprises 0.1 to 0.4 parts of 1,1,3,3-tetramethylguanidine, 1.0 to 2.0 parts of dimethylcyclohexylamine, and 0.3 to 0.8 parts of (2-hydroxypropyl)trimethylformate; and / or, by weight, the polyurethane composition further comprises 0.8 to 1.5 parts of deionized water.

[0012] Thirdly, embodiments of this application also provide a polyurethane foam, which is obtained by foaming the above-mentioned polyurethane composition.

[0013] In some embodiments of this application, the polyurethane foam has a GWP ≤ 92 and a PFAS detection limit < 0.1 ppm; and / or, the polyurethane foam has a thermal conductivity λ ≤ 17.0 mW / (m²) at 10°C. K); and / or, the polyurethane foam has a compressive strength > 150 kPa, a density of 22 kg / m³ to 25 kg / m³, and a flow index > 0.9 cm / g; and / or, under a mold temperature of 40℃ ± 2℃, the demolding time of the polyurethane foam is ≤ 2.5 min.

[0014] Fourthly, 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 aforementioned polyurethane foam.

[0015] The foaming agent composition provided in this application, by employing low-GWP foaming agents such as trans-1,1,3,4-tetrafluorobutene, cyclopentane, and HFC-152a, combined with PFAS-free silane-modified starch foam stabilizer, enables the foaming agent composition to meet the environmental regulatory requirements of GWP≤100 and no PFAS residue (detection limit <0.1ppm), thus solving the problem that existing foaming agent compositions are difficult to meet environmental regulatory requirements.

[0016] The polyurethane composition provided in this application embodiment, by using the foaming agent composition provided in this application embodiment, enables the polyurethane foam prepared from the polyurethane composition to meet the environmental regulatory requirements of GWP≤100 and no PFAS residue (detection limit <0.1ppm). Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a flowchart illustrating the preparation method of polyurethane foam provided in an embodiment of this application. Detailed Implementation

[0019] 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.

[0020] In the description of this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. Additionally, 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 description," 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, features defined as "first" or "second" may explicitly or implicitly include one or more of the stated features.

[0021] 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.

[0022] This application provides a foaming agent composition, which, by mass parts, comprises 5 to 15 parts of trans-1,1,3,4-tetrafluorobutene (abbreviated as HFO-1336mzz(E)), 8 to 15 parts of cyclopentane, 1 to 3 parts of 1,1-difluoroethane (abbreviated as HFC-152a), and 1.0 to 2.5 parts of silane-modified starch.

[0023] Among them, trans-1,1,3,4-tetrafluorobutene (HFO-1336mzz(E)) has a GWP of 1, an ODP (ozone depletion potential) of 0, and a gas-phase thermal conductivity of <10 mW / (m K), is a core low-GWP component that can reduce the greenhouse effect of polyurethane foam and synergistically improve the thermal insulation properties of polyurethane foam (thermal conductivity ≤16.8mW / (m²)). K)), free of PFAS and with zero ozone depletion; cyclopentane is an alkane with GWP=0, ODP=0, and a boiling point of 49℃. It can synergistically reduce GWP, regulate the foaming rate (milky time 30s~40s), and optimize cell size (50-100μm). It is free of PFAS and with zero ozone depletion; 1,1-difluoroethane (HFC-152a) has GWP=125, ODP=0, and a boiling point of -25℃. It can improve the compatibility of foaming agents (stratification time>4h), enhance low-temperature (0℃~5℃) foaming stability (filling rate ≥98%), and is free of PFAS and has low GWP; the main function of silane-modified starch is to stabilize the cell structure and prevent cell collapse or merging during foaming (cell qualification rate>95%). It can replace silicone oil containing PFAS, and its environmental characteristics include no PFAS residue (detection limit <0.1ppm). This application utilizes low-GWP blowing agents such as trans-1,1,3,4-tetrafluorobutene, cyclopentane, and 1,1-difluoroethane, combined with PFAS-free silane-modified starch foam stabilizers, enabling the blowing agent composition to meet environmental regulations requiring GWP ≤ 100 and no PFAS residue (detection limit < 0.1 ppm), thus solving the problem that existing blowing agent compositions are difficult to meet environmental regulations.

[0024] For example, the mass fraction of trans-1,1,3,4-tetrafluorobutene 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 fraction of cyclopentane can be 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 fraction of 1,1-difluoroethane can be 1 part, The mass fractions of the silane-modified starch can be 1.2 parts, 1.5 parts, 1.8 parts, 2.0 parts, 2.2 parts, 2.5 parts, 2.7 parts, 3 parts, or any range between any two of the aforementioned values; the mass fractions of the silane-modified starch can be 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2.0 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, or any range between any two of the aforementioned values.

[0025] Optionally, the silane-modified starch comprises starch and a first silane grafted onto the starch. The silane-modified starch is prepared by grafting starch and the first silane at a mass ratio of 9:1 to 11:1, with a grafting rate of 8% to 25%. The first silane comprises one or more of γ-glycidoxypropyltrimethoxysilane (KH560), γ-aminopropyltriethoxysilane (KH550), γ-methacryloyloxypropyltrimethoxysilane (KH570), γ-mercaptopropyltriethoxysilane (KH580), and γ-glycidoxypropyltrimethoxysilane (KH590). For example, the mass ratio of starch to the first silane can be 9:1, 9.5:1, 10:1, 10.5:1, or 11:1, etc., and the grafting rate can be 8%, 10%, 12%, 15%, 16.5%, 18%, 20%, 22%, or 25%, etc. Silane-modified starch prepared using the above ratios is more conducive to stabilizing the cell structure, preventing cell collapse or merging during foaming, and can more effectively avoid PFAS residue.

[0026] This application also provides a polyurethane composition comprising a polyol composition, a blowing agent composition, and an isocyanate. The specific structure of the blowing agent composition is as described in the above embodiments. The main functions of the blowing agents such as trans-1,1,3,4-tetrafluorobutene, cyclopentane, and HFC-152a in the blowing agent composition are to provide foaming power, control foam density (22 kg / m³~25 kg / m³), and ensure 100% filling rate of the ultra-thin cavity. The foam stabilizer silane-modified starch in the blowing agent composition stabilizes the cell structure and prevents cell collapse or merging during foaming. The main function of the polyol composition is to provide reactive groups, construct a three-dimensional foam skeleton, and balance flowability and mechanical properties. The isocyanate reacts with the polyol composition to form a rigid foam skeleton, determining mechanical properties and controlling crosslinking density to adapt to the ultra-thin structure support.

[0027] Since this polyurethane composition 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.

[0028] In some embodiments of this application, the polyurethane composition comprises, by weight, 100 parts of the polyol composition, 15 to 33 parts of the blowing agent composition, and 120 to 150 parts of the isocyanate. By controlling the proportions of each component in the polyurethane composition within the above range, the polyurethane foam prepared using the polyurethane composition of this application possesses both environmental friendliness, good flowability, and good mechanical properties.

[0029] For example, the mass fractions of the foaming agent composition can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, or any range between any two of the aforementioned values; the mass fractions of the isocyanate can be 120 parts, 122 parts, 125 parts, 128 parts, 130 parts, 133 parts, 135 parts, 137 parts, 140 parts, 142 parts, 145 parts, 148 parts, 150 parts, or any range between any two of the aforementioned values.

[0030] Optionally, by weight, the polyol composition comprises 20-35 parts of pentaerythritol branched polyether, 15-30 parts of toluene diamine polyether, 25-40 parts of sucrose polyether, and 5-15 parts of phthalic anhydride polyester polyol. The pentaerythritol branched polyether has a functionality of 4, a hydroxyl value of 400-500 mg KOH / g, and a viscosity of 3000 mPa at 25°C. s~5000mPa Pentaerythritol branched polyether can reduce the viscosity of the system to improve the flow index (>0.9 cm / g), and the highly branched structure can enhance the crosslinking density (suitable for ultra-thin fillers). Its environmentally friendly characteristics include being PFAS-free and having good biodegradability. Toluene diamine polyether (SD7100) is an aromatic polyether with a hydroxyl value of 360 mg KOH / g~500 mg KOH / g and a viscosity of 2800 mPa at 25°C. s~3500mPa Toluene diamine polyether can improve the compressive strength (>150kPa) and heat resistance (dimensional stability at -30℃ to 60℃) of polyurethane foam, and can also adjust the reactivity to match the demolding time. It is PFAS-free and has low environmental residue. Sucrose polyether (GR-4110G) is a multifunctional polyether with a hydroxyl value of 360mgKOH / g~480mgKOH / g and a viscosity of 3200mPa at 25℃. s~4000mPa sucrose polyether can balance the gel / foaming reaction rate to optimize cell uniformity (closed-cell rate > 92%) and reduce thermal conductivity (≤ 17.0 mW / (m²)). Phthalic anhydride polyester polyol (PS-3152) is a polyester polyol with a hydroxyl value of 250mgKOH / g~350mgKOH / g and an acid value of ≤1.0mgKOH / g. Phthalic anhydride polyester polyol can improve dimensional stability (change rate ≤0.5% at -30℃ / 60℃), reduce closed-cell rate fluctuation (within ±2%), and is free of PFAS and biodegradable.

[0031] For example, the mass fraction of the pentaerythritol branched polyether can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, or any range between two of the aforementioned values; the mass fraction of the toluene diamine polyether can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, etc. The mass fractions of sucrose polyether can be 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, or any two of the aforementioned values; the mass fractions of phthalic anhydride polyester polyol can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or any two of the aforementioned values.

[0032] Optionally, pentaerythritol branched polyether can be prepared by the following method: using pentaerythritol as an initiator, pentaerythritol is subjected to a ring-opening polymerization reaction with EO (ethylene oxide) and PO (propylene oxide) to obtain pentaerythritol branched polyether; wherein the mass ratio of EO (ethylene oxide) to PO (propylene oxide) is (2.5~3.5):(6~8).

[0033] In some embodiments of this application, the NCO content of the isocyanate is 30.5%~31.5%, and the viscosity at 25°C is 180 mPa. s -220mPa s, hydrolyzed chlorine ≤0.05%. Optionally, the isocyanate includes one or more of polymethyl polyphenyl polyisocyanate (PM-200), phenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI) and toluene diisocyanate (TDI).

[0034] In some embodiments of this application, the polyurethane composition further includes 0.5 to 2.0 parts by weight of modified nano-calcium carbonate, wherein the modified nano-calcium carbonate is nano-calcium carbonate with a surface modified with a second silane. The second silane includes one or more of γ-aminopropyltriethoxysilane (KH550), γ-glycidyl etheroxypropyltrimethoxysilane (KH560), γ-methacryloyloxypropyltrimethoxysilane (KH570), γ-mercaptopropyltriethoxysilane (KH580), and γ-glycidyl etheroxypropyltrimethoxysilane (KH590). The modified nano-calcium carbonate has an activation degree ≥95%, a whiteness ≥93%, and can form "reinforcing points" on the cell walls, thereby improving the compressive strength of polyurethane foam at low density (more than 20% higher than without additives) without affecting flowability. It is environmentally friendly as it is PFAS-free and biodegradable.

[0035] For example, the mass fraction of the modified nano-calcium carbonate can be 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2.0 parts, or any range between any two of the aforementioned values.

[0036] Optionally, the mass fraction of the second silane in the modified nano-calcium carbonate is 1.0% to 3.0%, for example, it can be 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, or any range between two values. By controlling the mass fraction of the second silane within the above range, it is beneficial to improve the activation degree and whiteness of the modified nano-calcium carbonate, and the modified nano-calcium carbonate more effectively forms "reinforcing points" on the cell walls to improve the compressive strength of polyurethane foam.

[0037] Optionally, the modified nano-calcium carbonate has a particle size of 50 nm to 100 nm. For example, the particle size of the modified nano-calcium carbonate can be 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, or any range between two of the aforementioned values. By using modified nano-calcium carbonate with a particle size of 50 nm to 100 nm, the modified nano-calcium carbonate is easier to disperse and does not affect the flowability of the polyurethane foam.

[0038] In some embodiments of this application, the polyurethane composition further comprises, by weight, 1.4 to 3.2 parts of a composite catalyst, wherein the composite catalyst comprises 0.1 to 0.4 parts of 1,1,3,3-tetramethylguanidine (TMG), 1.0 to 2.0 parts of dimethylcyclohexylamine (PC-8), and 0.3 to 0.8 parts of (2-hydroxypropyl)trimethylformate (TMR-2). The main function of the composite catalyst is to regulate the reaction equilibrium to shorten the demolding time (≤2.5 min) and increase the degree of crosslinking to enhance storage stability (thermal conductivity change ≤1.1% over 3 months).

[0039] Among them, 1,1,3,3-tetramethylguanidine (TMG) is a guanidine-based strong basic catalyst with a purity ≥99% and a boiling point of 220℃. It can accelerate the isocyanate-hydroxyl gel reaction (30% faster than monoamine catalysis), is PFAS-free, and has low toxicity; dimethylcyclohexylamine (PC-8) is an aliphatic amine catalyst with a purity ≥98% and a viscosity of 5 mPa at 25℃. s~8mPa s can balance the foaming / gelation speed to avoid large pores, optimize the pore structure (increase the closed-cell rate by 3%~5%), and is PFAS-free and low in volatility; (2-hydroxypropyl)trimethylammonium formate (TMR-2) is an ammonium salt catalyst with a purity ≥97% and water solubility ≥99%. It can promote the trimerization reaction of isocyanates to improve the degree of crosslinking (increase the dimensional stability by 30%), reduce the high-temperature shrinkage rate, and is PFAS-free and low in toxicity.

[0040] For example, the mass fraction of the composite catalyst in the polyurethane composition can be 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts, 3.0 parts, 3.1 parts, 3.2 parts, or any range between any two of the aforementioned values. The mass fractions of 1,1,3,3-tetramethylguanidine can be 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, or any range between any two of the aforementioned values; the mass fractions of dimethylcyclohexylamine can be 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2.0 parts, or any range between any two of the aforementioned values; the mass fractions of (2-hydroxypropyl)trimethylformate can be 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.7 parts, 0.75 parts, 0.8 parts, or any range between any two of the aforementioned values.

[0041] Optionally, the polyurethane composition further comprises 0.8 to 1.5 parts by weight of deionized water. Exemplarily, the weight of deionized water can be 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5 parts, or any range between the aforementioned values. The deionized water has a conductivity ≤5 μS / cm and a pH of 6.5 to 7.5. As a chemical foaming agent, the deionized water can react with the NCO of isocyanate to generate CO2, assisting in adjusting the cell density. Its environmentally friendly characteristics include being harmless and pollution-free.

[0042] This application also provides a polyurethane foam, which is obtained by foaming the polyurethane composition according to any one of claims 3 to 9.

[0043] Specifically, the polyurethane foam has a GWP ≤ 92 (calculated according to IPCC AR5 method) and a PFAS detection limit < 0.1 ppm; and / or, the polyurethane foam has a thermal conductivity λ ≤ 17.0 mW / (m²) at 10°C. K); and / or, the polyurethane foam has a compressive strength > 150 kPa, a density of 22 kg / m³ to 25 kg / m³, and a flow index > 0.9 cm / g; and / or, under a mold temperature of 40℃ ± 2℃, the demolding time of the polyurethane foam is ≤ 2.5 min.

[0044] In some embodiments of this application, such as Figure 1 As shown, the method for preparing the polyurethane foam includes the following steps: S100. Mix the polyol composition and silane-modified starch to obtain a preliminary mixture; S200: Mix HFO-1336mzz(E), cyclopentane, HFC-152a and the initial mixture to obtain a premix; S300. The premixed material is mixed with isocyanate and foamed to obtain polyurethane foam.

[0045] Optionally, step S100 includes: stirring the polyol composition, composite catalyst, deionized water, silane-modified starch, and modified nano-calcium carbonate at 25℃±3℃ and 0.8MPa~1.2MPa for 1.0h~1.2h to obtain a preliminary mixture. Step S200 includes: mixing the foaming agent HFO-1336mzz(E), foaming agent HFC-152a, and the preliminary mixture at 0.7MPa~1.0MPa for 0.8h~1h, then adding cyclopentane, and mixing for a secondary time at 2.5MPa~3.0MPa for 0.5h~0.6h to obtain a premix. Step S300 includes: injecting the premix and isocyanate into the mold cavity of a mold at a pressure of 130bar±5bar with a filler factor of 1.2~1.4, and a mold temperature of 40℃±2℃, to obtain polyurethane foam after foaming.

[0046] This application reduces or avoids polyurethane foam delamination by employing a low-temperature premixing and two-stage pressurization process (first stage 0.7MPa~1.0MPa, second stage 2.5MPa~3.0MPa) when mixing the foaming agent (including HFO-1336mzz(E), HFC-152a and cyclopentane) with the initial mixture.

[0047] In summary, the polyurethane compositions provided in this application have, but are not limited to, the following advantages: (1) Using foaming agents such as HFO-1336mzz(E) (GWP=1), cyclopentane (GWP=0) and HFC-152a (GWP=125), and foam stabilizer silane-modified starch (PFAS detection limit <0.1ppm), a low GWP and PFAS-free synergistic system was formed. The overall GWP of the system was ≤100 (far lower than the requirement of GWP≤150 in the EU F-GAS regulations), PFAS was not detected (detection limit <0.1ppm), the gas phase thermal conductivity of the foaming agent was <10mW / (m•K), and the thermal conductivity of polyurethane foam at 10℃ was λ≤17.0mW / (m•K), which met the new energy efficiency standards and solved the problem of balancing environmental compliance and thermal insulation. The fluidity was improved by about 12% compared with the single HFO foaming system.

[0048] (2) By using pentaerythritol branched polyether (4 functionalities, high degree of molecular chain branching), it is beneficial to reduce the viscosity of the system and improve its fluidity; modified nano-calcium carbonate (silane-modified such as KH550) can combine with polyol hydroxyl groups to form "reinforcing points" on the cell wall, inhibiting cell collapse at low density, so that the density of polyurethane foam is 22 kg / m³. 3 ~25kg / m 3 (12%~15% lower than existing systems), compressive strength >150kPa (more than 20% higher than the unmodified nano-calcium carbonate system), flow index >0.9cm / g (more than 10% higher than existing systems), can fill 40mm ultra-thin refrigerator cavity (100% filling rate, no voids).

[0049] (3) A composite catalyst composed of TMG, PC-8 and TMR-2 is used. TMG is a strong alkaline catalyst that can accelerate the gelation reaction of isocyanate and hydroxyl groups. PC-8 can balance the foaming and gelation speeds. TMR-2 can promote the trimerization reaction of isocyanate and improve the degree of crosslinking. The three catalysts work together to shorten the curing time, so that the demolding time of polyurethane foam is ≤2.5min (about 37.5% shorter than the demolding time of the existing PC-5 catalyst system). After the polyurethane foam is stored at room temperature for 3 months, the change rate of milky white time and gel time is <5%, and the dimensional change rate at -30℃ / 60℃ for 24h is ≤0.5%, and the dimensional stability is improved by about 30%.

[0050] 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. Since this refrigeration device 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.

[0051] Optionally, the refrigeration equipment can be a refrigerator, freezer, biological sample transport box, or cold chain container, etc. Optionally, the thickness of the insulation layer is 35mm to 50mm, for example, it can be 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm, or any range between two of the aforementioned values.

[0052] 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.

[0053] Raw material preparation: Pentaerythritol branched polyether: In-house prepared. The specific preparation method is as follows: using pentaerythritol as an initiator, pentaerythritol is subjected to a ring-opening polymerization reaction with EO (ethylene oxide) and PO (propylene oxide). The mass ratio of EO to PO is 3:7, yielding pentaerythritol branched polyether. The hydroxyl value of the pentaerythritol branched polyether is 450 mg KOH / g, and its viscosity at 25°C is 4000 mPa. s; Toluene diamine polyether: Industrial grade, purchased from Jurong Ningwu New Materials Co., Ltd. (Toluene diamine polyether series); Sucrose polyether: industrial grade, purchased from Hebei Yadong Chemical Group; Phthalic anhydride polyester polyol: industrial grade, purchased from Zhangjiagang Nanguang Chemical Co., Ltd. HFO-1336mzz(E): Purchased from Chemours Chemical Company; Cyclopentane: purchased from Huntsman Corporation; HFC-152a: Industrial grade, purchased from Chemours Chemical Company; Silane-modified starch: self-made, specifically prepared by grafting starch and KH560 at a mass ratio of 10:1 to obtain silane-modified starch with a grafting rate of 16.5%. The viscosity of the silane-modified starch at 25℃ is 1000 mPa. s, solid content ≥98%; Modified nano-calcium carbonate: purchased from Nanoport Company, particle size 80nm; TMG: Industrial grade, purchased from Aladdin Reagents Company; PC-8: Industrial grade, purchased from Nanjing Shuguang Chemical Co., Ltd.; TMR-2: Industrial grade, purchased from Shanghai Yuanye Biotechnology Co., Ltd.; Deionized water: purchased from Wahaha Group; PM-200: Industrial grade, purchased from Wanhua Chemical Company.

[0054] Example 1 Example 1 provides a polyurethane foam, the preparation method of which includes the following steps: (1) Pentaerythritol branched polyether, toluene diamine polyether, sucrose polyether, phthalic anhydride polyester polyol, TMG, PC-8, TMR-2, deionized water, silane-modified starch and modified nano calcium carbonate were stirred at 25°C and 1.0 MPa for 1.0 h to obtain a preliminary mixture; (2) HFO-1336mzz(E), HFC-152a and the initial mixture were mixed at 1.0 MPa for 0.8 h, and then cyclopentane was added and the mixture was mixed for 0.5 h at 3.0 MPa to obtain a premix. (3) The premixed mixture and PM-200 (NCO31%) were injected into the mold cavity of the mold at a pressure of 130 bar with a fill factor of 1.3. The mold cavity size was 1100mm×300mm×40mm (ultra-thin refrigerator simulation cavity). The mold temperature was 40℃±2℃. Polyurethane foam was obtained after foaming.

[0055] Example 2 Example 2 is basically the same as Example 1, except that the mass fractions of HFO-1336mzz(E) and cyclopentane added in Example 2 are different from those in Example 1.

[0056] Example 3 Example 3 is basically the same as Example 1, except that the mass fraction of modified nano-calcium carbonate added in Example 3 is different from that in Example 1.

[0057] Example 4 Example 4 is basically the same as Example 1, except that the mass fractions of TMG and PC-8 added in Example 4 are different from those in Example 1.

[0058] Example 5 Example 5 is basically the same as Example 1, except that the mold cavity size used in Example 5 is 1200mm×400mm×35mm (the actual ultra-thin refrigerator compartment cavity).

[0059] Example 6 Example 6 is basically the same as Example 1, except that the premix in Example 6 is foamed after being sealed and stored at room temperature for 3 months.

[0060] The amounts (parts by mass) of each component in Examples 1 to 6 are shown in Table 1 below.

[0061] Table 1

[0062] Comparative Example 1 Comparative Example 1 is basically the same as Example 1, with the main difference being that LBA (i.e., trans-1-chloro-3,3,3-trifluoropropene) and HFC-245fa (i.e., 1,1,1,3,3-pentafluoropropane) are used in Comparative Example 1 to replace HFO-1336mzz(E) and HFC-152a in Example 1, and PFAS-containing silicone oil L-6952 is added.

[0063] Comparative Example 2 Comparative Example 2 is basically the same as Example 1, the main difference being that LBA and HFC-245fa are used to replace HFO-1336mzz(E) and HFC-152a in Example 1 in Comparative Example 2, and no modified nano calcium carbonate is added in Comparative Example 2.

[0064] Comparative Example 3 Comparative Example 3 is basically the same as Example 1, except that LBA and HFC-245fa are used to replace HFO-1336mzz(E) and HFC-152a in Example 1, and PC-5 is used to replace TMG in Example 1.

[0065] Comparative Example 4 Comparative Example 4 is basically the same as Example 1, the main difference being that LBA and HFC-245fa are used to replace HFO-1336mzz(E) and HFC-152a in Example 1, and PFAS-containing silicone oil L-6988 is added.

[0066] The amounts (parts by mass) of each component in Comparative Examples 1 to 4 are shown in Table 2 below.

[0067] Table 2

[0068] Performance tests were conducted on the polyurethane foams of Examples 1-6 and Comparative Examples 1-4, and the test results are detailed in Table 3 below. The performance test items included: GWP, PFAS detection amount, thermal conductivity at 10℃, density, compressive strength, flow index, filler content, demolding time, dimensional change rate at -30℃, dimensional change rate at 60℃, and thermal conductivity change rate after 3 months of storage.

[0069] The testing methods for each performance aspect are as follows: GWP: Calculated according to IPCC AR5 method; PFAS: Determined by ion chromatography according to GB / T 5750.10-2023; Thermal conductivity at 10℃: measured according to ISO 12939-01; Density: Measured according to ASTM 1622-88; Compressive strength: measured according to DIN 53421-06-84; Flow index: Vertical mold (30cm high) foaming method, test foam height / injection weight (cm / g); Demolding time: The time from when foam is injected into the mold cavity to when the mold is opened and no foam sticks to the surface; Dimensional change rate: According to GB / T 8811-2008, the dimensional change rate of polyurethane foam at -30℃ for 24 hours and at 60℃ for 24 hours were tested.

[0070] Fill rate: The percentage of void area was measured using CT scans of the polyurethane foam.

[0071] Table 3

[0072] As shown in Table 3, none of the polyurethane foams in Examples 1 to 6 contained PFAS, and their GWP was ≤92, which was far superior to the polyurethane foam in Comparative Example 1 (GWP=580, and contained PFAS) and the polyurethane foam in Comparative Example 4 (containing PFAS), meeting the environmental regulations (GWP≤100, no PFAS).

[0073] The polyurethane foam of Example 5 has a flow index of 0.94 cm / g and can fill 100% of a 35mm ultrathin cavity, exhibiting good ultrathin adaptability. In contrast, the polyurethane foam of Comparative Example 1 has a flow index of 0.82 cm / g and a filling rate of only 85%.

[0074] The polyurethane foam of Example 3 (with 1.5 parts of modified nano-calcium carbonate added) has a compressive strength of 165 kPa, which is 28.9% higher than that of Comparative Example 2 (without modified nano-calcium carbonate). The polyurethane foam density of Example 3 is still 23.6 kg / m³, achieving low density and high strength.

[0075] Example 4 (with 0.3 parts of TMG catalyst added) had a demolding time of 2.0 min, which was 55.6% shorter than Comparative Example 3 (with PC-5 catalyst added); Example 6 had a thermal conductivity change rate of only 1.1% after 3 months of storage, which was better than Comparative Example 1 (thermal conductivity change rate of 5.6%), achieving rapid demolding and good stability.

[0076] In summary, the polyurethane foam provided in this application can solve the following technical problems: (1) Solving the problem of insufficient environmental compliance of existing polyurethane foam: Existing polyurethane foam relies on high GWP blowing agents such as HFC-245fa (GWP=1030) and HFC-134a (GWP=1430) and uses siloxane stabilizers containing PFAS, which does not comply with F-GAS regulations (limiting GWP>150) and REACH regulations (limiting PFAS); This application uses HFO-1336mzz(E) (GWP=1), cyclopentane (GWP=0) and HFC-152a (GWP=125) as ternary blowing agents, combined with PFAS-free silane-modified starch stabilizers, to achieve GWP≤100 and PFAS not detected (detection limit<0.1ppm), meeting the requirements of environmental regulations.

[0077] (2) Solving the problem of poor compatibility of ultra-thin refrigerators: Ultra-thin refrigerators (foam thickness ≤ 50 mm) require foam with high fluidity to fill complex narrow channel cavities. The existing polyurethane foam has a flow index ≤ 0.86 cm / g, which makes it difficult to fill ultra-thin cavities ≤ 50 mm (prone to problems of incomplete filling and uneven density), and has a low density (< 25 kg / m³). 3 The compressive strength under the given conditions is <140kPa, which cannot meet the structural support requirements. This application uses pentaerythritol branched polyether (to reduce viscosity and improve flowability) and modified nano-calcium carbonate with KH550 surface modification (to strengthen the cell walls) to achieve a polyurethane foam flow index >0.9cm / g (capable of 100% filling a 35mm cavity) and a density of 22kg / m³. 3 ~25kg / m 3 With a compressive strength >150kPa, it achieves high strength and high fluidity at low density, making it suitable for ultra-thin refrigerators.

[0078] (3) Solving the problems of low production efficiency and poor storage stability: The existing polyurethane foam has a demolding time of ≥4min and a slow curing speed, which restricts the production line cycle time. In addition, the storage temperature stability of some foaming systems using LBA is poor. After one month of storage at room temperature, the thermal conductivity increases by ≥0.5mW / (m K), increasing the difficulty of production control; this application uses a composite catalytic system composed of TMG, PC-8 and TMR-2 to accelerate curing and ensure dimensional stability, shortening the demolding time to ≤2.5min (increasing production efficiency by 60%), and the thermal conductivity change rate after the premix is ​​stored at room temperature for 3 months is only 1.1%, and the dimensional change rate (-30℃ / 60℃) is ≤0.6%, reducing the difficulty of production control.

[0079] 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.

[0080] The above provides a detailed description of the foaming agent composition, polyurethane composition, polyurethane foam, 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 foaming agent composition, characterized in that, By mass, it includes 5 to 15 parts of trans-1,1,3,4-tetrafluorobutene, 8 to 15 parts of cyclopentane, 1 to 3 parts of 1,1-difluoroethane, and 1.0 to 2.5 parts of silane-modified starch.

2. The foaming agent composition according to claim 1, characterized in that, The silane-modified starch is prepared by grafting starch and first silane at a mass ratio of 9:1 to 11:1, with a grafting rate of 8% to 25%.

3. The foaming agent composition according to claim 2, characterized in that, The first silane includes one or more of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

4. A polyurethane composition, characterized in that, It includes a polyol composition, a foaming agent composition, and an isocyanate, wherein the foaming agent composition is the foaming agent composition according to any one of claims 1 to 3.

5. The polyurethane composition according to claim 4, characterized in that, The polyurethane composition comprises, by weight, 100 parts of the polyol composition, 15 to 33 parts of the foaming agent composition, and 120 to 150 parts of the isocyanate.

6. The polyurethane composition according to claim 5, characterized in that, The polyol composition comprises, by weight parts, 20 to 35 parts of pentaerythritol branched polyether, 15 to 30 parts of toluene diamine polyether, 25 to 40 parts of sucrose polyether, and 5 to 15 parts of phthalic anhydride polyester polyol.

7. The polyurethane composition according to any one of claims 4 to 6, characterized in that, The polyurethane composition further comprises 0.5 to 2.0 parts of modified nano-calcium carbonate by weight, wherein the modified nano-calcium carbonate is nano-calcium carbonate with a second silane modified on its surface.

8. The polyurethane composition according to claim 7, characterized in that, The second silane has a mass fraction of 1.0% to 3.0% in the modified nano-calcium carbonate; And / or, the second silane comprises one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane; And / or, the particle size of the modified nano-calcium carbonate is 50nm~100nm.

9. The polyurethane composition according to claim 4, characterized in that, The polyurethane composition further comprises, by weight, 1.4 to 3.2 parts of a composite catalyst, wherein the composite catalyst comprises 0.1 to 0.4 parts of 1,1,3,3-tetramethylguanidine, 1.0 to 2.0 parts of dimethylcyclohexylamine, and 0.3 to 0.8 parts of (2-hydroxypropyl)trimethylformate. And / or, by weight, the polyurethane composition further comprises 0.8 to 1.5 parts of deionized water.

10. A polyurethane foam, characterized in that, The polyurethane foam is obtained by foaming the polyurethane composition according to any one of claims 4 to 9.

11. The polyurethane foam according to claim 10, characterized in that, The polyurethane foam has a GWP ≤ 92 and a PFAS detection limit < 0.1 ppm; And / or, the thermal conductivity λ of the polyurethane foam at 10°C is ≤17.0 mW / (m K); And / or, the polyurethane foam has a compressive strength >150KPa, a density of 22kg / m³~25kg / m³, and a flow index >0.9cm / g; And / or, under the condition of a mold temperature of 40℃±2℃, the demolding time of the polyurethane foam is ≤2.5min.

12. A refrigeration device, characterized in that, Includes an insulation layer, wherein the insulation layer is made of polyurethane foam as described in any one of claims 10 to 11.

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