A polyurethane foam, a method for producing the same, and use thereof

Abstract

This invention discloses a polyurethane foam, its preparation method, and its applications. The polyurethane composition, by weight, comprises the following components: 55-100 parts polyether polyol, 0-45 parts polyester polyol, 0.7-7 parts surfactant, 3-17 parts composite catalyst, 0.7-9 parts water, 7-65 parts composite blowing agent, and isocyanate with an isocyanate index of 1.1-1.6. The composite blowing agent, by weight (100%), comprises 9-70% pentane, 3-75% decafluorocyclopentane, and 0-35% butane. The blowing agents used in this invention produce a synergistic effect, reducing the defects caused by using individual physical blowing agents alone. This allows customers to obtain polyurethane products with superior foam performance, providing better choices for ultra-low energy consumption and inner liner materials in the industry.

Description

Technical Field

[0001] This invention relates to the field of polyurethane foam, and more particularly to a polyurethane foam, its preparation method, and its application. Background Technology

[0002] Polyurethane foam is a high-performance polymer material. Compositionally, it is mainly produced by the reaction of polyether polyols or polyester polyols with isocyanates, and also includes catalysts, foaming agents, flame retardants, and foam stabilizers. Functionally, polyurethane foam is characterized by its relatively low density, high compressive strength, good thermal insulation properties, and ease of production. In terms of applications, polyurethane foam is widely used in building exterior wall insulation, refrigeration equipment, automotive interiors, and various packaging materials, providing greater convenience to our lives. Currently, its most widespread application is in the insulation layer of refrigeration equipment, primarily refrigerators and freezers. Refrigeration equipment requires low energy consumption and low density to effectively reduce electricity consumption and transportation costs. To achieve this, it is necessary to improve the thermal insulation effect and foam strength of the polyurethane insulation layer.

[0003] The first-generation blowing agent CFC-11 (chloroform) and the second-generation blowing agent HCFC-141B (dichloroethane) were phased out by the industry due to their serious damage to the ozone layer. The third-generation blowing agent HFC-245fa (pentafluoropropane) has also been included in the quota control list. Alkane blowing agents and HFO blowing agents have become the consensus in the industry as alternatives.

[0004] Currently, the most common alkane blowing agents in the industry are pentane and butane. Because their global warming potential (GWP) and ozone depletion potential (ODP) are zero, they are widely used. However, pentane blowing agents still have many drawbacks in use. Using pentane as a blowing agent results in high gas thermal conductivity, high boiling point, low foam strength, poor compatibility with polyether polyols, and high concentrations can cause pentane to overflow, leading to cholesterol corrosion. These factors greatly limit the promotion and application of pentane blowing agents. Therefore, to address the shortcomings of pentane, the industry often adds low-boiling-point alkanes such as n-butane (R600) or isobutane (R600a) to the pentane system in pursuit of high strength. Although n-butane (R600) and isobutane (R600a) have good strength, their compatibility with polyethers is even worse than that of pentane, making them more prone to liner corrosion and liner collapse. Moreover, their poor thermal conductivity and limited addition amount cannot solve the problems of pentane foaming systems. To improve thermal conductivity, HFO foaming agent is added to the system. Therefore, the mainstream combination in the industry is CP / CI + HFO + R600 / R600a.

[0005] HFO-type blowing agents are hydrofluoroolefin blowing agents, including HFO-1233zd(E) (trans-1-chloro,3,3,3-trifluoropropene), HFO-1336mzz(Z) (cis-hexafluorobutene), HFO-1336mzz(E) (trans-hexafluorobutene), and HFO-1234ze(E) (trans-tetrafluoropropene), etc. HFO-1336mzz(Z) and HFO-1336mzz(E) are not widely used in the industry due to their complex production processes and high prices. HFO-1234z... Because e(E) is unstable and easily decomposes at high temperatures, its inherent properties cannot be fully realized. Therefore, the mainstream HFO in the industry is HFO-1233zd(E). Although HFO-1233zd(E) (1-chloro,3,3,3-trifluoropropylene) is popular in the industry, its storage time in the compound cannot be too long. This is because it easily undergoes a complexation reaction with the milky white catalyst, reducing its stability and causing it to lose its properties. Furthermore, because it contains double bonds, it will decompose under atmospheric pressure for a long time, causing air pollution. At the same time, since HFO-1233zd(E) itself has a relatively high boiling point of 19℃, it is not effective in reducing the overall injection volume of the compound. HFO-1233zd(E) also cannot compensate for the low solubility of pentane and butane in polyether compounds. On the contrary, the decomposition of HFO-1233zd(E) will further reduce the solubility of pentane and butane in the polyether compound, leading to more severe corrosion and pitting.

[0006] This patent, CN114940738B, describes a combination of pentane, HFO-1233zd(E), and propane to improve foam performance, resulting in polyurethane foam with fine pores and good thermal conductivity. It also reduces foam density while maintaining foam stability, which helps control raw material costs and reduces corrosivity to the plastic liner. However, while this combination can reduce the probability of HFO-1233zd(E) complexing with the milky white catalyst, it cannot eliminate the possibility of complexation between HFO-1233zd(E) and the milky white catalyst, nor can it solve the problem of HFO-1233zd(E) decomposing in the atmosphere.

[0007] Therefore, how to create an environmentally friendly foaming agent for the preparation of polyurethane foam, so that the prepared foam has the advantages of low density, good stability, low thermal conductivity and high strength, is a key research focus in the industry. Summary of the Invention

[0008] To address the above technical problems, this invention proposes a polyurethane foam, its preparation method, and its applications.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A polyurethane foam comprising the following components in parts by weight:

[0011] 55-100 parts of polyether polyol,

[0012] 0-45 parts of polyester polyol

[0013] Surfactant 0.7 to 7 parts,

[0014] Catalyst 3-17 parts,

[0015] Water 0.7–9 parts,

[0016] 7-65 parts of compound foaming agent,

[0017] Isocyanates with an isocyanate index of 1.1 to 1.6;

[0018] The composite foaming agent, based on a total mass of 100%, includes pentane (9-70%), decafluorocyclopentane (3-75%), and butane (0-35%).

[0019] Preferably, the composite foaming agent comprises, by weight, 10-65% pentane, 5-70% decafluorocyclopentane, and 7-30% butane.

[0020] Decafluorocyclopentane, due to its cyclic structure, has better strength than HFO-1233zd(E), is structurally stable and does not decompose, and is less prone to complexation reactions with milky white catalysts. This can effectively reduce the injection volume and production costs. Since the gas thermal conductivity of decafluorocyclopentane is lower than that of HFO-1233zd(E), it can effectively reduce foam thermal conductivity, which can better reduce energy consumption in the refrigeration industry and prepare for the industry's ultra-high energy consumption level. As a solubilizer, decafluorocyclopentane can also improve the compatibility of pentane and butane, reduce liner corrosion and denting, and bring more choices to the liner industry.

[0021] In a preferred embodiment of the present invention, the polyether polyol includes polyether polyol A, polyether polyol B, polyether polyol C, and polyether polyol D;

[0022] The polyether polyol A has a hydroxyl value of 250-500 mgKOH / g and a functionality of 6-8. The initiator of the polyether polyol A is at least one of xylitol, sucrose, and sorbitol.

[0023] The polyether polyol B is an amino polyether polyol with a hydroxyl value of 250-500 mgKOH / g and a functionality of 3-6. The initiator of the polyether polyol B is one or more of o-toluenediamine, p-toluenediamine, and m-toluenediamine.

[0024] The polyether polyol C has a hydroxyl value of 200-500 mgKOH / g and a functionality of 3-6. The initiator of the polyether polyol C is vegetable oil, preferably one or more of soybean oil, castor oil, etc.

[0025] The polyether polyol D has a hydroxyl value of 120-270 mgKOH / g and a functionality of 2-4. The initiator of the polyether polyol D is one or more of diethylene glycol, propylene glycol, and glycerol.

[0026] In a preferred embodiment of the present invention, the polyether polyol, based on a total mass of 100%, has the following proportions for each component:

[0027] Polyether polyol A: 4-75%, preferably 7-70%.

[0028] Polyether polyol B: 3-79%, preferably 5-75%.

[0029] Polyether polyol C 0-70%, preferably 8-60%

[0030] The polyether polyol D is 0-40%, preferably 7-27%.

[0031] The polyether used in the polyether polyol can provide sufficient rigidity to the foam. The active amine polyether and highly active catalyst can effectively encapsulate low-boiling-point butane and decafluorocyclopentane, reducing the escape of low-boiling-point blowing agents, thereby improving the filling performance and density distribution of the foam, improving the dimensional stability of the foam, reducing foam breakage, and improving the smoothness of the foam surface.

[0032] In a preferred embodiment of the present invention, the polyester polyol has a hydroxyl value of 170-350 mgKOH / g and a functionality of 2-4. Preferably, the polyester polyol is an aromatic polyester polyol, and more preferably it is prepared by using phthalic anhydride and polyol.

[0033] In a preferred embodiment of the present invention, the surfactant is a silicon-carbon surfactant, preferably at least one of silicone oil B8471, silicone oil L6863, or silicone oil AK8830.

[0034] In a preferred embodiment of the present invention, the composite catalyst comprises a foaming catalyst, a gel catalyst, and a trimerizing catalyst, wherein the mass ratio of the foaming catalyst, the gel catalyst, and the trimerizing catalyst is (0-1.5):(0.3-5.5):(0-2.5), preferably (0-1.2):(1.5-4.5):(0.7-2.1).

[0035] Preferably, the foaming catalyst is an amine catalyst, and more preferably a mixture of one or more of pentamethyldiethylenetriamine and bis-dimethylaminoethyl ether in any proportion;

[0036] Preferably, the gel catalyst is an amine catalyst, and more preferably a mixture of one or more of methylimidazole, N,N-dimethylcyclohexylamine and N-methylpyrrolidone in any proportion;

[0037] Preferably, the trimerizing catalyst is one or more of potassium formate, 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine, 2-hydroxy-N,N,N-trimethyl-1-propylaminocarbamate (TMR-2), and potassium acetate in any proportion.

[0038] Preferably, the pentane is at least one of cyclopentane and isopentane, and more preferably cyclopentane or a mixture of cyclopentane and isopentane, wherein the mass content of the two in the mixture is 30-90% cyclopentane and 10-70% isopentane.

[0039] Preferably, the butane is at least one of n-butane and isobutane, and more preferably n-butane, because n-butane has a low boiling point, high strength, and low thermal conductivity.

[0040] Preferably, the decafluorocyclopentane has the characteristics of low boiling point, low thermal conductivity, good stability, and high strength.

[0041] In a preferred embodiment of the present invention, the isocyanate is polymeric MDI, preferably polymeric MDI with an NCO content of 29-32%, and more preferably one or more of Wanhua PM-200, Wanhua PM-2010 and Wanhua PM-400.

[0042] The present invention also provides a method for preparing the polyurethane foam described above, comprising the following steps:

[0043] 1) Mix polyether polyol, polyester polyol, surfactant, composite catalyst, water, and composite foaming agent evenly, and cool to below 10°C to obtain a mixture;

[0044] 2) Mix the mixture obtained in step 1) with isocyanate and foam to obtain rigid polyurethane foam;

[0045] Preferably, the foaming is high-pressure foaming, and the high-pressure foaming conditions are a nozzle pressure of 130-150 kPa and a temperature of 15-20°C.

[0046] The present invention also provides the application of the polyurethane foam described above as a refrigerator material.

[0047] The beneficial effects of the polyurethane composition in this invention are as follows:

[0048] (1) This polyurethane foam has an ODP of 0 and a low GWP value, making it an eco-friendly foam.

[0049] (2) The polyurethane foam prepared by the polyurethane composition of the present invention has strong rigidity, good dimensional stability, long storage time and good stability, which can effectively reduce the amount of foaming material used, thereby reducing the foam density and improving the customer return rate.

[0050] (3) The polyurethane foam prepared by the polyurethane composition of the present invention has a low thermal conductivity and good heat insulation performance, which can reduce the power consumption of the refrigerator and extend the service life of the refrigerator.

[0051] (4) The polyurethane foam prepared by the composition of the present invention has good filling performance, strong uniformity of cell structure, and can be quickly demolded and molded, which can effectively reduce bubble breakage and improve the flatness of the product. Detailed Implementation

[0052] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0053] The sources of the main materials and reagents involved in the following specific implementation methods are as follows:

[0054] trans-1-chloro-3,3,3-trifluoropropene (HFO-1233zd(E)): Honeywell

[0055] Decafluorocyclopentane: Wanrunda

[0056] Cyclopentane (CP): Longshan Chemical

[0057] Isopentane (IP): Longshan Chemical

[0058] n-Butane: Haolong Chemical

[0059] Polymerized MDI: Wanhua PM-200

[0060] Silicone Oil B8471: Evonik

[0061] Silicone oil L6863: Momentive

[0062] Silicone Oil AK8830: Demei Shichuang

[0063] Pentamethyldiethylenetriamine: Newdian Chemicals

[0064] Bis-dimethylaminoethyl ether: Qiguang Enterprise

[0065] Methylimidazole: Merck Chemicals

[0066] Potassium formate: Fengtai Chemical

[0067] 1,3,5-Tris(dimethylaminopropyl)hexahydrotriazine: New Classical Chemistry

[0068] N,N-Dimethylcyclohexylamine: Xindian Chemicals

[0069] N-Methylpyrrolidone: BASF

[0070] 2-Hydroxy-N,N,N-Trimethyl-1-propylcarbamate (TMR-2): New Classic Chemicals

[0071] Potassium acetate: Zhuochuang Chemical

[0072] Polyether polyol A1: sucrose as initiator, hydroxyl value 400 mg KOH / g, functionality 7, Wanhua Chemical (Ningbo) Rongwei

[0073] Polyether polyol A2: sucrose as the initiator, hydroxyl value of 500 mg KOH / g, functionality of 7.8, Wanhua Chemical (Ningbo) Rongwei

[0074] Polyether polyol A3: sorbitol as initiator, hydroxyl value 250 mg KOH / g, functionality 6.4, Wanhua Chemical (Ningbo) Rongwei

[0075] Polyether polyol A4: sorbitol as initiator, hydroxyl value 350 mg KOH / g, functionality 6.9, Wanhua Chemical (Ningbo) Rongwei

[0076] Polyether polyol B1: Initiated with o-toluenediamine, hydroxyl value 275 mg KOH / g, functionality 4.2, Wanhua Chemical (Ningbo) Rongwei

[0077] Polyether polyol B2: Initiated with o-toluenediamine, hydroxyl value 410 mgKOH / g, functionality 5, Wanhua Chemical (Ningbo) Rongwei

[0078] Polyether polyol B3: Initiated with o-toluenediamine, hydroxyl value 500 mg KOH / g, functionality 6, Wanhua Chemical (Ningbo) Rongwei

[0079] Polyether polyol C1: Soybean oil as initiator, hydroxyl value 205 mg KOH / g, functionality 3.1, Wanhua Chemical (Ningbo) Rongwei

[0080] Polyether polyol C2: Soybean oil as initiator, hydroxyl value 310 mg KOH / g, functionality 4.5, Wanhua Chemical (Ningbo) Rongwei

[0081] Polyether polyol C3: Castor oil initiator, hydroxyl value 450 mg KOH / g, functionality 5, Wanhua Chemical (Ningbo) Rongwei

[0082] Polyether polyol C4: Castor oil as initiator, hydroxyl value 490 mg KOH / g, functionality 5.7, Wanhua Chemical (Ningbo) Rongwei

[0083] Polyether polyol D1: Diethylene glycol as initiator, hydroxyl value 120 mg KOH / g, functionality 2.3, Wanhua Chemical (Ningbo) Rongwei

[0084] Polyether polyol D2: Diethylene glycol is used as the initiator, with a hydroxyl value of 190 mg KOH / g and a functionality of 3.1. (Wanhua Chemical (Ningbo) Rongwei)

[0085] Polyether polyol D3: Diethylene glycol as initiator, hydroxyl value 250 mg KOH / g, functionality 3.5, Wanhua Chemical (Ningbo) Rongwei

[0086] Polyether polyol D4: Propylene glycol as initiator, hydroxyl value 270 mg KOH / g, functionality 3.8, Wanhua Chemical (Ningbo) Rongwei

[0087] Phthalic anhydride polyester polyol E1: hydroxyl value 350 mg KOH / g, functionality 4.8, Nanjing Stepan Company.

[0088] Phthalic anhydride polyester polyol E2: hydroxyl value 175 mg KOH / g, functionality 2.7, Nanjing Stepan Company.

[0089] Phthalic anhydride polyester polyol E3: hydroxyl value 220 mg KOH / g, functionality 3, Nanjing Stepan Company

[0090] The specific implementation methods for testing the performance of polyurethane foam are as follows:

[0091] The foam core density test shall be conducted in accordance with the standard: GB / T 6343-2009

[0092] The thermal conductivity of foam was tested according to standard GB / T 10295-2008.

[0093] Demolding expansion rate test: The inner dimensions of the mold cavity are length * width * height = 70cm * 40cm * 10cm, the temperature inside the mold is 45℃; the ambient temperature is 25℃, and the humidity is 45%. During the evaluation experiment, the mold is placed horizontally (i.e., 10cm is upward), and foam raw material at a constant temperature (18℃) is injected into the mold. The foam is removed within 5 minutes, and the expansion coefficient of the foam in the 10cm thickness direction is measured, which is the demolding expansion.

[0094] The foam compressive strength test shall be conducted in accordance with the standard: GB / T 8813-2008

[0095] Foam dimensional stability testing was conducted according to standard GB / T 8811-2008.

[0096] Surface bubble test: The Laneige mold test method was used. The mold cavity dimensions were 5cm*20cm*200cm, and the mold temperature was 45℃; the ambient temperature was 25℃, and the humidity was 45%. During the evaluation experiment, the mold was placed vertically (200cm upwards), and 650g of foam material at a constant temperature (18℃) was injected into the mold. After curing, the foam was removed, and the surface bubble grade was judged based on the size and number of bubbles. Specifically, bubbles with a longest dimension of 3-6cm were designated as Class A bubbles, and bubbles with a longest dimension >6cm were designated as Class B bubbles. The number of Class A and Class B bubbles on the foam surface was counted, and one Class B bubble was counted as two Class A bubbles. The surface bubble grade was divided into three levels: I, II, and III. Level I indicates 1-10 Class A bubbles; Level II indicates 10-20 Class A bubbles; and Level III indicates >20 Class A bubbles.

[0097] Flow index: The Laneige mold test method was used. The mold cavity dimensions were 5cm*20cm*200cm, and the mold temperature was 45℃. The ambient temperature was 25℃ and the humidity was 45%. During the evaluation experiment, the mold was placed vertically (i.e., 200cm upwards), and 500g of foam raw material at a constant temperature (18℃) was injected into the mold. The initial height of the foam was recorded. After curing, the foam was removed, and the rising height of the foam was measured. The flow index is calculated as: foam height / foam weight.

[0098] Overfill rate: The Laneige mold test method was used. The mold cavity dimensions were 5cm*20cm*200cm, and the mold temperature was 45℃; the ambient temperature was 25℃, and the humidity was 45%. During the evaluation experiment, the mold was placed vertically (i.e., 200cm upwards), and foam material at a constant temperature (18℃) was injected into the mold. The amount of foam material that just filled the mold was measured as the exact fill (g). The specified filling amount (g) was then injected. The overfill rate was calculated as: specified filling amount / exact fill * 100%.

[0099]

Example 1

[0100] A polyurethane composition comprising the following components by weight:

[0101]

[0102] The composite foaming agent, based on a total mass of 100%, comprises 70% cyclopentane, 23% decafluorocyclopentane, and 7% isobutane.

[0103] The polyether polyol is composed of 75% polyether polyol A4, 3% polyether polyol B1, 22% polyether polyol C2, and 2% polyether polyol D3.

[0104] The polyester polyol is polyester polyol E1;

[0105] The composite catalyst contains 100% by mass N,N-dimethylcyclohexylamine.

[0106] The isocyanate is polymeric MDI, Wanhua PM-200.

[0107]

Example 2

[0108] A polyurethane composition comprising the following components by weight:

[0109]

[0110]

[0111] The composite foaming agent, based on a total mass of 100%, comprises 10% isopentane, 60% decafluorocyclopentane, and 30% isobutane.

[0112] The polyether polyol is composed of 4% polyether polyol A2, 79% polyether polyol B3, and 17% polyether polyol D1.

[0113] The polyester polyol is polyester polyol E2;

[0114] In the composite catalyst, the ratio of pentamethyldiethylenetriamine:N,N-dimethylcyclohexylamine:potassium acetate is 0.2:2:0.7 by mass.

[0115] The isocyanate is polymeric MDI, Wanhua PM-2010.

[0116]

Example 3

[0117] A polyurethane composition comprising the following components by weight:

[0118]

[0119] The composite foaming agent, based on a total mass of 100%, comprises 20% cyclopentane, 70% decafluorocyclopentane, and 10% isobutane.

[0120] The polyether polyol is composed of 10% polyether polyol A3, 20% polyether polyol B2, and 70% polyether polyol C3.

[0121] The polyester polyol is polyester polyol E3;

[0122] In the composite catalyst, the ratio of bis-dimethylaminoethyl ether: N-methylpyrrolidone: TMR-2 is 0.5:2.5:1, by mass.

[0123] The isocyanate is polymeric MDI, Wanhua PM-200.

[0124]

Example 4

[0125] A polyurethane composition comprising the following components by weight:

[0126]

[0127] The composite foaming agent, based on a total mass of 100%, comprises 70% of a pentane mixture (cyclopentane and isopentane 19:1), 5% of decafluorocyclopentane, and 25% of isobutane.

[0128] The polyether polyol is composed of 25% polyether polyol A2, 20% polyether polyol B2, 25% polyether polyol C1, and 30% polyether polyol D3.

[0129] The polyester polyol is polyester polyol E1;

[0130] In the composite catalyst, the ratio of pentamethyldiethylenetriamine: N-methylpyrrolidone: potassium formate is 0.7:3:1.5 by mass.

[0131] The isocyanate is polymeric MDI, Wanhua PM-400.

[0132]

Example 5

[0133] A polyurethane composition comprising the following components by weight:

[0134]

[0135] The composite foaming agent, based on a total mass of 100%, comprises 30% of a pentane mixture (cyclopentane and isopentane 3:7), 65% of decafluorocyclopentane, and 5% of isobutane.

[0136] The polyether polyol is composed of 55% polyether polyol A1, 30% polyether polyol B3, 8% polyether polyol C3, and 7% polyether polyol D2.

[0137] The polyester polyol is polyester polyol E3;

[0138] In the composite catalyst, the ratio of bis-dimethylaminoethyl ether: N-methylpyrrolidone: potassium acetate is 0.8:4:1.8, by mass.

[0139] The isocyanate is polymeric MDI, Wanhua PM-200.

[0140]

Example 6

[0141] A polyurethane composition comprising the following components by weight:

[0142]

[0143] The composite foaming agent, based on a total mass of 100%, comprises 41% of a pentane mixture (cyclopentane and isopentane 5:5), 51% of decafluorocyclopentane, and 8% of isobutane.

[0144] The polyether polyol is composed of 20% polyether polyol A3, 40% polyether polyol B1, 20% polyether polyol C4, and 20% polyether polyol D1.

[0145] The polyester polyol is polyester polyol E2;

[0146] In the composite catalyst, the ratio of bis-dimethylaminoethyl ether: N,N-dimethylcyclohexylamine: TMR-2 is 1:5:2, by mass.

[0147] The isocyanate is polymeric MDI, Wanhua PM-2010.

[0148]

Example 7

[0149] A polyurethane composition comprising the following components by weight:

[0150]

[0151] The composite foaming agent, based on a total mass of 100%, comprises 57% isopentane, 30% decafluorocyclopentane, and 13% isobutane.

[0152] The polyether polyol is composed of 70% polyether polyol A4, 5% polyether polyol B3, 10% polyether polyol C1, and 15% polyether polyol D2.

[0153] The polyester polyol is polyester polyol E1;

[0154] The composite catalyst contains 100% methylimidazole by mass.

[0155] The isocyanate is polymeric MDI, Wanhua PM-200.

[0156]

Example 8

[0157] A polyurethane composition comprising the following components by weight:

[0158]

[0159] The composite foaming agent, based on a total mass of 100%, comprises 47% cyclopentane, 37% decafluorocyclopentane, and 16% isobutane.

[0160] The polyether polyol is composed of 35% polyether polyol A2, 50% polyether polyol B1, 8% polyether polyol C1, and 7% polyether polyol D3.

[0161] The polyester polyol is polyester polyol E2;

[0162] In the composite catalyst, the ratio of pentamethyldiethylenetriamine: N,N-dimethylcyclohexylamine: potassium acetate is 0.2:1.5:0.7 by mass.

[0163] The isocyanate is polymeric MDI, Wanhua PM-2010.

[0164]

Example 9

[0165] A polyurethane composition comprising the following components by weight:

[0166]

[0167]

[0168] The composite foaming agent, based on a total mass of 100%, comprises 20% pentane (cyclopentane:isopentane 4:6), 44% decafluorocyclopentane, and 19% isobutane.

[0169] The polyether polyol is composed of 15% polyether polyol A4, 23% polyether polyol B2, 60% polyether polyol C2, and 12% polyether polyol D2.

[0170] The polyester polyol is polyester polyol E3;

[0171] In the composite catalyst, the ratio of bis-dimethylaminoethyl ether: N-methylpyrrolidone: TMR-2 is 0.5:2.5:1, by mass.

[0172] The isocyanate is polymeric MDI, Wanhua PM-200.

[0173]

Example 10

[0174] A polyurethane composition comprising the following components by weight:

[0175]

[0176] The composite foaming agent, based on a total mass of 100%, comprises 60% of a pentane mixture (cyclopentane and isopentane 6:4), 17% of decafluorocyclopentane, and 23% of isobutane.

[0177] The polyether polyol is composed of 8% polyether polyol A3, 70% polyether polyol B2, 14% polyether polyol C3, and 8% polyether polyol D1.

[0178] The polyester polyol is polyester polyol E1;

[0179] In the composite catalyst, the ratio of pentamethyldiethylenetriamine:methylimidazole:potassium acetate is 0.7:3:1.5 by mass.

[0180] The isocyanate is polymeric MDI, Wanhua PM-400.

[0181]

Example 11

[0182] A polyurethane composition comprising the following components by weight:

[0183]

[0184] The composite foaming agent, based on a total mass of 100%, comprises 61% of a pentane mixture (cyclopentane and isopentane 7:3), 11% of decafluorocyclopentane, and 28% of isobutane.

[0185] The polyether polyol is composed of 27% polyether polyol A1, 18% polyether polyol B1, 40% polyether polyol C4, and 15% polyether polyol D4.

[0186] In the composite catalyst, the ratio of bis-dimethylaminoethyl ether: N-methylpyrrolidone: potassium formate is 0.8:4:1.8, by mass.

[0187] The isocyanate is polymeric MDI, Wanhua PM-200.

[0188] Comparative Example 1

[0189] A polyurethane composition was provided using a method substantially the same as that in Example 1, except that decafluorocyclopentane was replaced with the same mass of HFO-1233ZD(E).

[0190] Comparative Example 2

[0191] A polyurethane composition was provided using a method substantially the same as that in Example 1, except that the composite blowing agent was replaced with the same mass of cyclopentane.

[0192] Comparative Example 3

[0193] A polyurethane composition was provided using a method substantially the same as that in Example 1, except that the composite blowing agent was replaced with the same mass of isobutane.

[0194] Comparative Example 4

[0195] A polyurethane composition was provided using a method substantially the same as that in Example 1, except that the proportions of the substances in the composite foaming agent were modified so that, based on a total mass of 100%, the composite foaming agent comprised 7% cyclopentane, 58% decafluorocyclopentane, and 35% isobutane.

[0196]

Application Example

[0197] Polyurethane foams were prepared using the polyurethane compositions prepared in Examples 1-11 and Comparative Examples 1-6, respectively, according to the following method:

[0198] 1) Mix polyether polyol, polyester polyol, surfactant, composite catalyst, water, and composite foaming agent evenly, and cool to below 10°C to obtain a mixture;

[0199] 2) The mixture obtained in step 1) is mixed with isocyanate and foamed under high pressure to obtain rigid polyurethane foam.

[0200] The high-pressure foaming conditions are: nozzle pressure 140 kPa and temperature 18°C.

[0201] The polyurethane foams prepared from the polyurethane compositions in each embodiment and the comparative example were subjected to the performance tests shown in Table 1. As can be seen from Table 1, the polyurethane foams prepared using the method of the present invention, under the same overfill rate, exhibit better thermal conductivity, demolding expansion coefficient, surface bubbles, and foam strength than the comparative example. Therefore, under the same process parameters, the technical solution of the present invention can effectively reduce the amount of raw material injected and decrease the foam density, thereby reducing production costs.

[0202] Table 1. Performance Parameters of Polyurethane Foam

[0203]

[0204]

Claims

1. A polyurethane foam, characterized in that, The components comprise the following parts by weight: 55-100 parts of polyether polyol, 0-45 parts of polyester polyol Surfactant 0.7 to 7 parts, Catalyst 3-17 parts, Water 0.7–9 parts, 7-65 parts of compound foaming agent, Isocyanates with an isocyanate index of 1.1 to 1.6; The composite foaming agent, based on a total mass of 100%, comprises 9-70% pentane, 3-75% decafluorocyclopentane, and 0-35% butane; Preferably, the composite foaming agent comprises, by weight, 10-65% pentane, 5-70% decafluorocyclopentane, and 7-30% butane.

2. The polyurethane foam according to claim 1, characterized in that, The polyether polyols include polyether polyol A, polyether polyol B, polyether polyol C, and polyether polyol D; The polyether polyol A has a hydroxyl value of 250-500 mgKOH / g and a functionality of 6-8. The initiator of the polyether polyol A is at least one of xylitol, sucrose, and sorbitol. The polyether polyol B is an amino polyether polyol with a hydroxyl value of 250-500 mgKOH / g and a functionality of 3-6. The initiator of the polyether polyol B is one or more of o-toluenediamine, p-toluenediamine, and m-toluenediamine. The polyether polyol C has a hydroxyl value of 200-500 mgKOH / g and a functionality of 3-6. The initiator of the polyether polyol C is vegetable oil, preferably one or more of soybean oil and castor oil. The polyether polyol D has a hydroxyl value of 120-270 mgKOH / g and a functionality of 2-4. The initiator of the polyether polyol D is one or more of diethylene glycol, propylene glycol, and glycerol.

3. The polyurethane foam according to any one of claims 1-2, characterized in that, The polyether polyol, based on a total mass of 100%, has the following proportions for each component: Polyether polyol A: 4-75%, preferably 7-70%. Polyether polyol B: 3-79%, preferably 5-75%. Polyether polyol C 0-70%, preferably 8-60% The polyether polyol D is 0-40%, preferably 7-27%.

4. The polyurethane foam according to any one of claims 1-3, characterized in that, The polyester polyol has a hydroxyl value of 170-350 mgKOH / g and a functionality of 2-4. Preferably, the polyester polyol is an aromatic polyester polyol, and more preferably it is prepared by using phthalic anhydride and polyol.

5. The polyurethane foam according to any one of claims 1-4, characterized in that, The surfactant is a silicon-carbon surfactant, preferably at least one of silicone oil B8471, silicone oil L6863, or silicone oil AK8830.

6. The polyurethane foam according to any one of claims 1-5, characterized in that, The composite catalyst includes a foaming catalyst, a gel catalyst, and a trimerizing catalyst, wherein the mass ratio of the foaming catalyst, the gel catalyst, and the trimerizing catalyst is (0-1.5):(0.3-5.5):(0-2.5), preferably (0-1.2):(1.5-4.5):(0.7-2.1). Preferably, the foaming catalyst is an amine catalyst, and more preferably a mixture of one or more of pentamethyldiethylenetriamine and bis-dimethylaminoethyl ether in any proportion; Preferably, the gel catalyst is an amine catalyst, and more preferably a mixture of one or more of methylimidazole, N,N-dimethylcyclohexylamine and N-methylpyrrolidone in any proportion; Preferably, the trimerizing catalyst is one or more of potassium formate, 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine, 2-hydroxy-N,N,N-trimethyl-1-propylaminocarbamate (TMR-2), and potassium acetate in any proportion.

7. The polyurethane foam according to any one of claims 1-6, characterized in that, The pentane is at least one of cyclopentane and isopentane, and more preferably cyclopentane or a mixture of cyclopentane and isopentane, wherein the mass content of the two in the mixture is 30-90% cyclopentane and 10-70% isopentane. Preferably, the butane is at least one of n-butane and isobutane, and more preferably n-butane.

8. The polyurethane foam according to any one of claims 1-7, characterized in that, The isocyanate is polymeric MDI, preferably polymeric MDI with an NCO content of 29-32%.

9. The method for preparing polyurethane foam according to any one of claims 1-8, characterized in that, Includes the following steps: 1) Mix polyether polyol, polyester polyol, surfactant, composite catalyst, water, and composite foaming agent evenly, and cool to below 10°C to obtain a mixture; 2) Mix the mixture obtained in step 1) with isocyanate and foam to obtain rigid polyurethane foam; Preferably, the foaming is high-pressure foaming, wherein the high-pressure foaming conditions are a nozzle pressure of 130-150 kPa and a temperature of 15-20°C.

10. The application of the polyurethane foam according to any one of claims 1-8 or the polyurethane foam prepared by the preparation method according to claim 9 as a refrigerator material.

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