A polyether polyol, a method of making and a polyurethane rigid foam made therewith and a method of making the same

Abstract

The application discloses a polyether polyol and a preparation method thereof, and polyurethane rigid foam prepared from the polyether polyol and a preparation method thereof. The polyether polyol is prepared by addition reaction of 2,2'-diaminobenzyl as a starting agent and an alkylene oxide under self-catalysis, and the structure of the polyether polyol is shown in formula I: wherein n1, n2, n3 and n4 are independently selected from integers not less than 0, and preferably independently selected from integers of 1-5; R1-R4 are the same in H or methyl. The polyether polyol can be applied to preparation of a pure HFO-1233zd (also known as LBA, the same below) blowing agent system polyurethane foam of a thin-wall refrigerator, so that the flow performance of the system polyurethane foam is improved, the filling effect on the refrigerator is more favorable, filling defects and surface defects are reduced, and meanwhile, the flexibility is improved, the overall bending strength is improved, and the foam rupture phenomenon caused by large thickness change of the foam layer is reduced under the premise of ensuring the strength.

Description

Technical Field

[0001] This invention belongs to the field of polyether polyol technology, specifically relating to a pure LBA system polyether polyol for thin-walled refrigerators, its preparation method, and a rigid polyurethane foam made therefrom, as well as its preparation method. Background Technology

[0002] In recent years, with people's increasing pursuit of quality of life, a high-end, thin-walled refrigerator has emerged on the market. The side panels of this type of refrigerator are more than 50% thinner than those of traditional refrigerators. This allows for more storage space within the same external dimensions, resulting in more efficient space utilization. The thinner side panels also cater to the current trend of minimalist and elegant aesthetics. From an environmental perspective, the reduced volume of rigid polyurethane foam filling the refrigerator cavity significantly reduces the amount of solid waste generated when the refrigerator is discarded, achieving considerable environmental benefits.

[0003] Furthermore, as many countries around the world further raise their energy consumption standards, the commonly used CP system and mixed foaming agent systems such as CP and 245fa are increasingly unable to meet customer requirements at the highest energy consumption levels. Among them, LBA foaming agent, as a newer generation of foaming agent, has a lower thermal conductivity, lower ODP and GWP values, and good safety performance, and has received increasing attention and application. In particular, for the pure LBA system, its excellent performance in reducing energy consumption makes manufacturers more inclined to use it in low-energy-consumption products that build their own high-end brands, such as thin-walled refrigerator product lines that use the pure LBA system.

[0004] However, the current thin-walled refrigerator product line using the pure LBA system has also encountered some problems. Because of the reduced thickness of the refrigerator cavity, rigid polyurethane foam faces difficulties flowing inside the refrigerator, especially in the side panels, resulting in unsatisfactory filling and significant quality risks such as poor filling and numerous surface defects. These risks not only cause appearance defects but also greatly affect energy consumption test results, preventing the product from achieving its expected performance. Furthermore, because the side panels are thinner than the back panel, foam cracking, which was already prone to occur during daily use due to significant variations in foam layer thickness, becomes more likely. This is another quality risk that requires attention and a significant factor affecting energy consumption testing. Addressing the aforementioned flow and filling performance issues, as well as improving the foam cracking caused by significant variations in foam layer thickness, would effectively reduce quality risks during production and daily use, ensure energy efficiency ratings are maintained, solve problems in practical applications, and achieve a double benefit of economic and environmental advantages. Summary of the Invention

[0005] To address the aforementioned shortcomings in the prior art, this invention provides a 2,2'-diaminobibenzyl polyether polyol. This polyether polyol enhances the structure and properties of polyurethane foam in the flow and filling of the container, reduces the generation of surface defects, and also possesses better flexibility and certain compressive strength properties. The polyurethane foam prepared from this polyether polyol can be used as insulation material for household appliances such as refrigerators and freezers.

[0006] Another aspect of the present invention is to provide a method for preparing such a polyether polyol.

[0007] Another aspect of the present invention is to provide a pure LBA system rigid polyurethane foam using this polyether polyol as one of the raw materials. By using the novel polyether and optimizing the catalyst system, the flow and filling properties of the polyurethane foam system are effectively improved, ensuring compressive strength while taking into account better flexibility, resulting in a high-performance polyurethane foam system.

[0008] Another aspect of the present invention provides a method for preparing rigid polyurethane foam using the polyether polyol.

[0009] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0010] A polyether polyol with the general structural formula shown in Formula I:

[0011]

[0012] Wherein, n1, n2, n3 and n4 are each independently selected from integers not less than 0, preferably each independently selected from integers from 1 to 5; R1 to R4 are the same one of H or methyl.

[0013] In one specific embodiment, the hydroxyl value of the polyether polyol is 320–600 mg KOH / g, preferably 380–440 mg KOH / g.

[0014] In another aspect of the present invention, a method for preparing the aforementioned polyether polyol is to use 2,2'-diaminobibenzyl of formula (II) as a starting material and, under autocatalysis, perform an addition reaction with an oxidized olefin to obtain the polyether polyol of formula (I).

[0015]

[0016] In one specific embodiment, the oxidized olefin is ethylene oxide, propylene oxide, or a homogeneous mixture of ethylene oxide and propylene oxide, preferably propylene oxide; the molar ratio of 2,2'-diaminobibenzyl to the oxidized olefin is 1:2 to 10, preferably 1:3 to 8, and more preferably 1:4 to 8.

[0017] In one specific embodiment, the preparation method is as follows: after nitrogen purging, 2,2'-diaminobibenzyl is melted, stirred at 90-130°C, then mixed with oxidized olefins, reacted at 100-150°C, and maintained at 0.1-0.3 MPa pressure for 1-5 hours until the pressure no longer decreases, to obtain the polyether polyol.

[0018] In another aspect of the present invention, a rigid polyurethane foam is prepared by foaming and injection molding of a component comprising the following parts by weight using a high-pressure foaming machine:

[0019] (a) 100 parts of the composition;

[0020] (b) 20-40 parts of foaming agent;

[0021] (c) 120–175 parts of isocyanate;

[0022] The composition comprises 86-95 parts of a polyether; 2-5 parts of a surfactant; 2-6 parts of a catalyst; and 1-3 parts of water. The polyether is composed of 40-60 parts of the aforementioned polyether polyol A, 10-40 parts of polyether polyol B obtained by addition reaction of sucrose with propylene oxide, 0-20 parts of polyether polyol C obtained by addition reaction of sorbitol with propylene oxide, and 1-8 parts of polyether polyol D obtained by addition reaction of glycerol with propylene oxide.

[0023] In one specific embodiment, the polyether polyol A has a hydroxyl value of 380–440 mg KOH / g; the polyether polyol B has a hydroxyl value of 350–410 mg KOH / g; the polyether polyol C has a hydroxyl value of 410–470 mg KOH / g; and the polyether polyol D has a hydroxyl value of 160–220 mg KOH / g.

[0024] In one specific implementation, the foaming agent is LBA foaming agent;

[0025] The isocyanate is polymeric MDI, preferably polymeric MDI with an NCO content of 30-32%; most preferably one or more of polymeric MDI Wanhua PM-200, polymeric MDI Wanhua PM-2010 and polymeric MDI Wanhua PM-400; preferably, the isocyanate index of the rigid polyurethane foam is 1.08-1.30.

[0026] In one specific embodiment, the surfactant is at least one of the following: alkali metal salt of fatty acid, amine salt of fatty acid, castor oil, ricinoleic acid, and siloxane polymer, preferably at least one of silicone oil AK8805, silicone oil AK8830, silicone oil B8525, and silicone oil B8545.

[0027] The catalyst is a composite catalyst, including a foaming catalyst, a gel catalyst and a trimerizing catalyst. Preferably, the mass ratio of the foaming catalyst to the gel catalyst and the trimerizing catalyst is 1-2:2-7:0.1-2.

[0028] More preferably, the foaming catalyst is one or more of pentamethyldiethylenetriamine, tetramethylhexanediamine, or bis-dimethylethyl ether;

[0029] The gel catalyst is one or more of dimethylbenzylamine, dimethylcyclohexane, or triethylenediamine;

[0030] The trimerizing catalyst is one or a mixture of potassium acetate or 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine.

[0031] In another aspect of the present invention, a method for preparing the aforementioned rigid polyurethane foam includes the following steps: mixing a combination of polyether, surfactant, catalyst and water uniformly according to a formula to obtain a composition, mixing the composition and a foaming agent uniformly, and filling the isocyanate and the composition containing the foaming agent into a mold using a high-pressure foaming machine to prepare rigid polyurethane foam; preferably, the operating conditions of the foaming machine are: material temperature 14-18°C, operating pressure 100-150 bar.

[0032] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0033] 1) The polyether polyol of this invention is a novel polyether monomer using 2,2'-diaminobibenzyl as an initiator. The distance between the two amine groups in the initiator group structure is relatively large, resulting in less steric hindrance between the group structures. This allows the hydrogen atom on the nitrogen atom to react more completely with the added olefin oxide, significantly reducing the overall reactivity of the structure with the NCO group. Consequently, the proportion of hydrogen atoms directly bonded to the nitrogen atom in the prepared polyether polyol product is significantly reduced, meaning the content of highly reactive amine groups in the product is significantly lower, resulting in a lower overall product activity. Then, in the initial stage of the polyurethane foam foaming reaction, the amine groups and NCO groups... The reaction can be reduced, so that in the early stage when the foam has good filling and flow properties, the degree of cross-linking does not increase too quickly. The foam can maintain good flow properties for a longer reaction time, thereby achieving a better filling effect. At the same time, it reduces the surface defects caused by the foam shearing after contact with the outer board during the flow filling process due to excessively rapid and high cross-linking. It has better appearance performance, reduces the flow and filling difficulties caused by excessively narrow foam channels, and reduces more surface defects. The resulting refrigerator products have a smooth and good appearance, which ensures the overall performance of the refrigerator and solves the concerns and engineering problems of enterprises in the actual application process.

[0034] 2) The polyurethane foam produced by this invention, during daily use, has a certain degree of flexibility due to the presence of ethyl alkane linkages in the 2,2'-diaminobibenzyl polyether polyol, which allows for free rotation. This improves the foam's resilience caused by the increased variation in foam layer thickness after thinning the side panels. Furthermore, the presence of benzene rings ensures that structural rigidity is not compromised while improving flexibility, thus guaranteeing the overall strength of the foam product. This prevents long-term performance in refrigerators from being affected, particularly in terms of appearance and energy efficiency, greatly enhancing the user experience. Attached Figure Description

[0035] Figure 1 The image shows the nuclear magnetic resonance spectrum of the amine polyether polyol obtained in Example 2 of this invention.

[0036] Figure 2 The image shows the nuclear magnetic resonance spectrum of the amine polyether polyol obtained in Example 5 of this invention. Detailed Implementation

[0037] To better understand the technical solution of the present invention, the following embodiments will further illustrate the method provided by the present invention. However, the present invention is not limited to the listed embodiments, but should also include any other well-known modifications within the scope of the claims of the present invention.

[0038] The present invention relates to a polyether polyol using 2,2'-diaminobibenzyl as an initiator, the general structural formula of which is shown in formula (I):

[0039]

[0040] Wherein, n1, n2, n3, and n4 are each independently selected from positive integers not less than 0, preferably from positive integers from 1 to 5, for example, each independently selected from 1, 2, 3, 4, or 5. That is, n1, n2, n3, and n4 can be the same or different. R1 to R4 are H or methyl groups. R1 to R4 can be the same or different. Preferably, R1 to R4 are the same.

[0041] The novel polyether polyol has a hydroxyl value of 320–600 mgKOH / g, such as 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 550, 560, 580, 600 mgKOH / g, preferably 380–440 mgKOH / g.

[0042] The preparation method of the polyether polyol of the above general formula (I) includes: using 2,2'-diaminobibenzyl as the starting material, reacting it with oxidized olefins to obtain the polyether polyol shown in formula (I).

[0043] The 2,2'-diaminobibenzyl structure is shown in formula (II), and a polyether polyol with a specific structure is obtained by polymerization addition with an oxidized olefin.

[0044]

[0045] The 2,2'-diaminobibenzyl is commercially available, for example, from Shanghai Mairui Chemical Co., Ltd. The oxidized olefin is propylene oxide and / or ethylene oxide, for example, a mixture of propylene oxide, ethylene oxide, propylene oxide, and ethylene oxide, more preferably propylene oxide. The molar ratio of the 2,2'-diaminobibenzyl to the oxidized olefin is 1:2 to 10, for example, 1:4, 1:6, 1:8, 1:9, or 1:10, preferably 1:3 to 8, more preferably 1:4 to 8. When the oxidized olefin is a mixture of propylene oxide and ethylene oxide, the ratio is not particularly limited, for example, a molar ratio of 1:1, 1:2, 1:3, 1:5, 2:1, 3:1, or 5:1, etc.

[0046] The preparation method of the polyether polyol is well known in the art. In one embodiment, the preparation method of the polyether polyol of the above general formula (I) is as follows: After nitrogen purging, 2,2'-diaminobibenzyl is melted, stirred at 100°C, and then mixed with oxidized olefins. The mixture is reacted at 100-150°C, for example, at 110°C, 130°C, 140°C, and 150°C, while maintaining a pressure of 0.1-0.3 MPa for 1-5 hours, for example, at 0.1 MPa for 1 hour. The pressure was applied for 2 hours, then for 3 hours at 0.1 MPa, then for 4 hours at 0.1 MPa, then for 5 hours at 0.1 MPa, then for 1 hour at 0.2 MPa, then for 2 hours at 0.2 MPa, then for 3 hours at 0.2 MPa, then for 4 hours at 0.2 MPa, then for 5 hours at 0.2 MPa, then for 1 hour at 0.3 MPa, then for 2 hours at 0.3 MPa, then for 3 hours at 0.3 MPa, then for 4 hours at 0.3 MPa, then for 5 hours at 0.3 MPa, until the pressure no longer decreased, resulting in polyether polyol.

[0047] The present invention also provides a rigid polyurethane foam prepared using the above-mentioned polyether polyol, which is obtained by foaming a component comprising the following parts by weight using a foaming machine, preferably by mixing in a high-pressure foaming machine:

[0048] (a) 100 parts of the composition;

[0049] (b) 20 to 40 parts of foaming agent, for example, 20, 24, 28, 32, 36, or 40 parts;

[0050] (c) 120 to 175 parts of isocyanate, for example 136, 140, 148, or 160 parts;

[0051] The composition comprises 86-95 parts of a polyether, for example 88, 90, 92, or 94 parts; 2-5 parts of a surfactant, for example 3 parts; 2-6 parts of a catalyst, for example 2, 3, 4, 5, or 6 parts; and 1-3 parts of water, for example 2 parts. The polyether is composed of 40-60 parts of polyether polyol A of the above general formula (I), for example 40, 50, or 60 parts; 10-40 parts of polyether polyol B obtained by addition reaction of sucrose with propylene oxide, for example 10, 20, 30, or 40 parts; 0-20 parts of polyether polyol C obtained by addition reaction of sorbitol with propylene oxide, for example 0, 10, or 20 parts; and 1-8 parts of polyether polyol D obtained by addition reaction of glycerol with propylene oxide, for example 2, 4, or 6 parts.

[0052] In the polyurethane rigid foam component composition according to the present invention, preferably, the polyether polyol A of formula (I) has a hydroxyl value of 320 to 600 mgKOH / g, for example, 340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 540, 560, 580, 600 mgKOH / g.

[0053] The polyether polyol B has a hydroxyl value of 350–410 mgKOH / g, for example, 350, 360, 370, 380, 390, or 400 mgKOH / g, and is prepared by addition reaction of sucrose with propylene oxide.

[0054] The polyether polyol has a C-hydroxyl value of 410-470 mgKOH / g, for example, 410, 420, 430, 440, 450, or 460 mgKOH / g, and is prepared by addition reaction of sorbitol with propylene oxide.

[0055] The polyether polyol has a D hydroxyl value of 160-220 mgKOH / g, for example, 160, 170, 180, 190, or 200 mgKOH / g, and is prepared by addition reaction of glycerol as an initiator with propylene oxide.

[0056] In the polyurethane rigid foam composition according to the present invention, the surfactant is at least one selected from the following: alkali metal salt of fatty acid, amine salt of fatty acid, castor oil, ricinoleic acid, and siloxane polymer, preferably at least one selected from the following: silicone oil AK8805 and silicone oil AK8830 from Nanjing Demeishichuang Chemical Co., Ltd., or silicone oil B8525 and silicone oil B8545 from Evonik Degussa. These surfactants have strong nucleation effects and good stability, which is beneficial for reducing the thermal conductivity of the foam.

[0057] In the composition of the rigid polyurethane foam component according to the present invention, the catalyst is a composite catalyst, which includes a foaming catalyst, a gel catalyst and a trimerizing catalyst, wherein the mass ratio of the foaming catalyst to the gel catalyst and the trimerizing catalyst is 1-2:3-7:0.1-2, for example 1:3:1, 2:4:2 or 2:5:1, but not limited thereto.

[0058] The foaming catalyst is one or more of pentamethyldiethylenetriamine, tetramethylhexanediamine and bis-dimethylethyl ether in any proportion; the gel catalyst is one or more of dimethylbenzylamine, dimethylcyclohexane and triethylenediamine in any proportion; and the trimerizing catalyst is one or more of potassium acetate or 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine in any proportion.

[0059] In the components of the rigid polyurethane foam according to the present invention, the blowing agent is 20 to 40 parts of LBA blowing agent, for example 20, 25, 30, 35, or 40 parts; preferably, 26 to 34 parts of LBA blowing agent, for example, LBA blowing agent from Honeywell, such as HFO-1233zd, which is a commercially available product.

[0060] The isocyanate in the components of the rigid polyurethane foam according to the present invention is polymeric MDI (polymethylene polyphenyl polyisocyanate), preferably polymeric MDI with an NCO content of 30-32%; most preferably one or more of polymeric MDI Wanhua PM-200, polymeric MDI Wanhua PM-2010 and polymeric MDI Wanhua PM-400, all of which are commercially available products.

[0061] According to the rigid polyurethane foam of the present invention, the isocyanate index of the rigid polyurethane foam is 1.08 to 1.30, for example 1.15, wherein the index is the ratio of the actual amount of isocyanate added to the theoretically calculated amount required to just consume the hydroxyl groups in the combined polyether and water.

[0062] The preparation process of the rigid polyurethane foam is well known in the art. In one embodiment, the preparation method of the rigid polyurethane foam of the present invention involves uniformly mixing the combined polyether, surfactant, catalyst and distilled water according to the aforementioned ratio to obtain a composition, uniformly mixing the composition with a blowing agent, and filling the isocyanate and the composition containing the blowing agent into a mold using a high-pressure foaming machine to prepare rigid polyurethane foam. The operating conditions of the foaming machine are: material temperature 14-18°C, for example 15, 16, 17 or 18°C, and operating pressure 100-150 bar, for example 110, 120, 130 or 140 bar.

[0063] The present invention will be further explained and illustrated below through more specific embodiments, but these do not constitute any limitation.

[0064] The sources of the main materials and reagents in the following examples and comparative examples are as follows:

[0065] 2,2'-Diaminobibenzyl, Shanghai Mairui Chemical Co., Ltd.;

[0066] Foaming agent: LBA(HFO-1233zd) (Honeywell);

[0067] Isocyanate: Wanhua Chemical PM-200;

[0068] Surfactant: Silicone oil B8545, Evonik;

[0069] Catalysts: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerization catalyst is potassium acetate (Evonik).

[0070] Polyether polyol A was prepared according to the embodiments of the present invention, and other polyether polyols were purchased from Wanhua Chemical (Ningbo) Rongwei.

[0071] Polyether polyol A1 is a traditional amine polyether in the industry, using o-toluenediamine as an initiator, with a hydroxyl value of 440 mgKOH / g.

[0072] Polyether polyol B uses sucrose as an initiator, and the product has a hydroxyl value of 380 mgKOH / g.

[0073] Polyether polyol C uses sorbitol as an initiator, and the hydroxyl value of the product is 435 mgKOH / g.

[0074] Polyether polyol D uses glycerol as an initiator, and the product has a hydroxyl value of 190 mg KOH / g.

[0075] Unless otherwise specified, all reagents used below are of analytical grade.

[0076] Polyurethane foam performance testing methods:

[0077] The foam core density test shall be conducted in accordance with the standard GB / T 6343-2009;

[0078] The thermal conductivity of foam was tested according to standard GB / T 10295-2008.

[0079] The foam compressive strength test shall be conducted in accordance with the standard GB / T 8813-2008;

[0080] The foam bending performance test shall be conducted in accordance with the standard: ISO 1209-2-90(E);

[0081] Foam dimensional stability testing was conducted in accordance with standard GB / T 8811-2008.

[0082] Example 1

[0083] 2,2'-Diaminobibenzyl (424 g, 2 mol) was added to the reactor, pressure was tested by nitrogen purging, and the mixture was heated to 100°C with stirring. 400 g of ethylene oxide was added to the reactor at a flow rate of 800 g / h, and the reaction was carried out at 110°C. The pressure was maintained at 0.1 MPa for 2 hours until the pressure no longer decreased, yielding a polyether polyol, where R1–R4 are all H, and n1, n2, n3, and n4 are all 1. The hydroxyl value, tested using the phthalic anhydride esterification method, was 591 mg KOH / g.

[0084] Example 2

[0085] 2,2'-Diaminobibenzyl (424 g, 2 mol) was added to a reactor, pressure was tested by nitrogen purging, and the mixture was heated to 100°C with stirring. 400 g of ethylene oxide was added to the reactor at a flow rate of 800 g / h, and the reaction was carried out at 130°C. The pressure was maintained at 0.1 MPa for 2.5 h until the pressure no longer decreased, yielding a polyether polyol, where R1–R4 are all H, and n1, n2, n3, and n4 are all 1. The hydroxyl value, tested using the phthalic anhydride esterification method, was 588 mg KOH / g.

[0086] The nuclear magnetic resonance spectrum of the prepared polyether polyol is as follows: Figure 1 As shown, the data is as follows: 1 H NMR (400MHz, CDCl3) δ = 7.14-7.08 (m, 2H), 6.92 (d, J = 6.8Hz, 2H), 6.62 (d, J = 6.8 Hz,2H),6.48-6.40(m,2H),4.85(s,4H),4.20(m,8H),3.73(m,8H),2.82(s,4H).

[0087] Example 3

[0088] 2,2'-Diaminobibenzyl (424 g, 2 mol) was added to a reaction vessel, pressure was tested by nitrogen purging, and the mixture was heated to 100°C with stirring. 550 g of propylene oxide was added to the reaction vessel at a flow rate of 800 g / h, and the reaction was carried out at 130°C. The pressure was maintained at 0.1 MPa for 3.5 h until the pressure no longer decreased, yielding a polyether polyol, wherein R1–R4 are all methyl groups, and n1, n2, n3, and n4 are all 1. The hydroxyl value, tested using the phthalic anhydride esterification method, was 524 mg KOH / g.

[0089] Example 4

[0090] 2,2'-Diaminobibenzyl (424 g, 2 mol) was added to a reactor, pressure was tested by nitrogen purging, and the mixture was heated to 100 °C with stirring. 550 g of propylene oxide was added to the reactor at a flow rate of 800 g / h, and the reaction was carried out at 130 °C. The pressure was maintained at 0.2 MPa for 3.5 h until the pressure no longer decreased, yielding a polyether polyol, wherein R1–R4 are all methyl groups, and n1, n2, n3, and n4 are all 1. The hydroxyl value, tested using the phthalic anhydride esterification method, was 515 mg KOH / g.

[0091] Example 5

[0092] 2,2'-Diaminobibenzyl (424 g, 2 mol) was added to a reaction vessel, pressure was tested by nitrogen purging, and the mixture was heated to 100 °C with stirring. 800 g of propylene oxide was added to the reaction vessel at a flow rate of 800 g / h, and the reaction was carried out at 140 °C. The pressure was maintained at 0.2 MPa for 4 hours until the pressure no longer decreased, yielding a polyether polyol, wherein R1–R4 are all methyl groups, and n1, n2, n3, and n4 are 2, 1, 2, and 1, respectively. The hydroxyl value, tested using the phthalic anhydride esterification method, was 411 mg KOH / g.

[0093] The nuclear magnetic resonance spectrum of the prepared polyether polyol is as follows: Figure 2 As shown, the data is as follows: 1 H NMR (400MHz, CDCl3) δ=7.14-7.08(m,2H),6.92(d,J=6.8Hz,2H),6.62(d,J=6.8Hz,2H),6.48-6.40(m,2H),5.37(s, 4H),3.96-3.84(m,2H),3.57-3.65(m,6H),3.38-3.30(m,8H),3.14-3.08(m,2H),2.82(s,4H),1.14-1.08(m,18H).

[0094] Example 6

[0095] 2,2'-Diaminobibenzyl (424 g, 2 mol) was added to a reaction vessel, pressure was tested by nitrogen purging, and the mixture was heated to 100 °C with stirring. 1000 g of propylene oxide was added to the reaction vessel at a flow rate of 800 g / h, and the reaction was carried out at 150 °C. The pressure was maintained at 0.3 MPa for 4.5 h until the pressure no longer decreased, yielding a polyether polyol, wherein R1–R4 are all methyl groups, and n1, n2, n3, and n4 are 3, 1, 3, and 1, respectively. The hydroxyl value, tested using the phthalic anhydride esterification method, was 341 mg KOH / g.

[0096] Example 7

[0097] Rigid polyurethane foam using the 2,2'-diaminobibenzyl polyether polyol system, raw material composition:

[0098] The mass ratio of the composition (89.7 parts of combined polyether, 3 parts of surfactant, 5.3 parts of composite catalyst, and 2 parts of distilled water) to LBA (Honeywell, the same below) and polyisocyanate (polymeric MDI Wanhua PM-200, the same below) is 100:32:151.8.

[0099] Combination polyethers (parts by weight): 50 parts of 2,2'-diaminobibenzyl polyether polyol A (prepared in Example 1); 25.7 parts of sucrose polyether polyol B (hydroxyl value 380 mg KOH / g); 10 parts of sorbitol polyether polyol C (hydroxyl value 435 mg KOH / g); and 4 parts of glycerol polyether polyol D (hydroxyl value 190 mg KOH / g).

[0100] Surfactant: 3 parts silicone oil B8545 (Evonik, the same below).

[0101] Composite catalyst: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerizing catalyst is potassium acetate. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:5.1:1 (mass ratio).

[0102] The preparation method of rigid polyurethane foam includes the following steps:

[0103] 1) Weigh each raw material according to the ratio, put the combined polyether, surfactant, composite catalyst, water and foaming agent into a container, and mix them thoroughly to obtain the composition mixture;

[0104] 2) The obtained mixture is mixed with polyisocyanate, foamed under high pressure at a material temperature of 17°C and a pressure of 130 bar (gauge pressure). The filling coefficient of the reaction mixture in the mold is 1.15, and the demolding time is 240 s to obtain rigid polyurethane foam.

[0105] Example 8

[0106] Rigid polyurethane foam using the 2,2'-diaminobibenzyl polyether polyol system, raw material composition:

[0107] The mass ratio of the composition (89.4 parts of combined polyether, 3 parts of surfactant, 5.6 parts of composite catalyst, and 2 parts of distilled water) to LBA and polyisocyanate (polymeric MDI Wanhua PM-200) is 100:32:151.8.

[0108] Combination polyethers (parts by weight): 50 parts of 2,2'-diaminobibenzyl polyether polyol A (prepared in Example 2); 25.4 parts of sucrose polyether polyol B (hydroxyl value 380 mg KOH / g); 10 parts of sorbitol polyether polyol C (hydroxyl value 435 mg KOH / g); and 4 parts of glycerol polyether polyol D (hydroxyl value 190 mg KOH / g).

[0109] Surfactant: 3 parts of silicone oil B8545.

[0110] Composite catalyst: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerizing catalyst is potassium acetate. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:5.5:1 (mass ratio).

[0111] The preparation method for rigid polyurethane foam is the same as in Example 7.

[0112] Example 9

[0113] Rigid polyurethane foam using the 2,2'-diaminobibenzyl polyether polyol system, raw material composition:

[0114] The mass ratio of the composition (90.8 parts of combined polyether, 3 parts of surfactant, 4.2 parts of composite catalyst, and 2 parts of distilled water) to LBA and polyisocyanate (polymeric MDI Wanhua PM-200) is 100:32:151.8.

[0115] Combination polyethers (parts by weight): 50 parts of 2,2'-diaminobibenzyl polyether polyol A (prepared in Example 3); 26.8 parts of sucrose polyether polyol B (hydroxyl value 380 mg KOH / g); 10 parts of sorbitol polyether polyol C (hydroxyl value 435 mg KOH / g); and 4 parts of glycerol polyether polyol D (hydroxyl value 190 mg KOH / g).

[0116] Surfactant: 3 parts of silicone oil B8545.

[0117] Composite catalyst: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerizing catalyst is potassium acetate. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:4.1:0.5 (mass ratio).

[0118] The preparation method for rigid polyurethane foam is the same as in Example 7.

[0119] Example 10

[0120] Rigid polyurethane foam using the 2,2'-diaminobibenzyl polyether polyol system, raw material composition:

[0121] The mass ratio of the composition (90.5 parts of combined polyether, 3 parts of surfactant, 4.5 parts of composite catalyst, and 2 parts of distilled water) to LBA and polyisocyanate (polymeric MDI Wanhua PM-200) is 100:32:151.8.

[0122] Combination polyethers (parts by weight): 50 parts of 2,2'-diaminobibenzyl polyether polyol A (prepared in Example 4); 26.5 parts of sucrose polyether polyol B (hydroxyl value 380 mg KOH / g); 10 parts of sorbitol polyether polyol C (hydroxyl value 435 mg KOH / g); and 4 parts of glycerol polyether polyol D (hydroxyl value 190 mg KOH / g).

[0123] Surfactant: 3 parts of silicone oil B8545.

[0124] Composite catalyst: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerizing catalyst is potassium acetate. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:4.4:0.5 (mass ratio).

[0125] The preparation method for rigid polyurethane foam is the same as in Example 7.

[0126] Example 11

[0127] Rigid polyurethane foam using the 2,2'-diaminobibenzyl polyether polyol system, raw material composition:

[0128] The mass ratio of the composition (90.2 parts of combined polyether, 3 parts of surfactant, 4.8 parts of composite catalyst, and 2 parts of distilled water) to LBA and polyisocyanate (polymeric MDI Wanhua PM-200) is 100:32:151.8.

[0129] Combination polyethers (parts by weight): 50 parts of 2,2'-diaminobibenzyl polyether polyol A (prepared in Example 5); 26.2 parts of sucrose polyether polyol B (hydroxyl value 380 mg KOH / g); 10 parts of sorbitol polyether polyol C (hydroxyl value 435 mg KOH / g); and 4 parts of glycerol polyether polyol D (hydroxyl value 190 mg KOH / g).

[0130] Surfactant: 3 parts of silicone oil B8545.

[0131] Composite catalyst: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerizing catalyst is potassium acetate. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:4.7:0.5 (mass ratio).

[0132] The preparation method for rigid polyurethane foam is the same as in Example 7.

[0133] Example 12

[0134] Rigid polyurethane foam using the 2,2'-diaminobibenzyl polyether polyol system, raw material composition:

[0135] The mass ratio of the composition (90.1 parts of combined polyether, 3 parts of surfactant, 4.9 parts of composite catalyst, and 2 parts of distilled water) to LBA and polyisocyanate (polymeric MDI Wanhua PM-200) is 100:32:151.8.

[0136] Combination polyethers (parts by weight): 50 parts of 2,2'-diaminobibenzyl polyether polyol A (prepared in Example 6); 26.1 parts of sucrose polyether polyol B (hydroxyl value 380 mg KOH / g); 10 parts of sorbitol polyether polyol C (hydroxyl value 435 mg KOH / g); and 4 parts of glycerol polyether polyol D (hydroxyl value 190 mg KOH / g).

[0137] Surfactant: 3 parts of silicone oil B8545.

[0138] Composite catalyst: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerizing catalyst is potassium acetate. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:4.9:0.5 (mass ratio).

[0139] The preparation method for rigid polyurethane foam is the same as in Example 7.

[0140] Example 13

[0141] Rigid polyurethane foam using the 2,2'-diaminobibenzyl polyether polyol system, raw material composition:

[0142] The mass ratio of the composition (89.9 parts of combined polyether, 3 parts of surfactant, 5.1 parts of composite catalyst, and 2 parts of distilled water) to LBA and polyisocyanate (polymeric MDI Wanhua PM-200) is 100:32:151.8.

[0143] Combination polyethers (parts by weight): 40 parts of 2,2'-diaminobibenzyl polyether polyol A (prepared in Example 5); 35.9 parts of sucrose polyether polyol B (hydroxyl value 380 mg KOH / g); 10 parts of sorbitol polyether polyol C (hydroxyl value 435 mg KOH / g); and 4 parts of glycerol polyether polyol D (hydroxyl value 190 mg KOH / g).

[0144] Surfactant: 3 parts of silicone oil B8545.

[0145] Composite catalyst: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerizing catalyst is potassium acetate. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:4.9:0.5 (mass ratio).

[0146] The preparation method for rigid polyurethane foam is the same as in Example 7.

[0147] Example 14

[0148] Rigid polyurethane foam using the 2,2'-diaminobibenzyl polyether polyol system, raw material composition:

[0149] The mass ratio of the composition (90.5 parts of combined polyether, 3 parts of surfactant, 4.5 parts of composite catalyst, and 2 parts of distilled water) to LBA and polyisocyanate (polymeric MDI Wanhua PM-200) is 100:32:151.8.

[0150] Combination polyethers (parts by weight): 60 parts of 2,2'-diaminobibenzyl polyether polyol A (prepared in Example 5); 16.5 parts of sucrose polyether polyol B (hydroxyl value 380 mg KOH / g); 10 parts of sorbitol polyether polyol C (hydroxyl value 435 mg KOH / g); and 4 parts of glycerol polyether polyol D (hydroxyl value 190 mg KOH / g).

[0151] Surfactant: 3 parts of silicone oil B8545.

[0152] Composite catalyst: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerizing catalyst is potassium acetate. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:4.5:0.5 (mass ratio).

[0153] The preparation method for rigid polyurethane foam is the same as in Example 7.

[0154] Example 15

[0155] Rigid polyurethane foam using the 2,2'-diaminobibenzyl polyether polyol system, raw material composition:

[0156] The mass ratio of the composition (90.2 parts of combined polyether, 3 parts of surfactant, 4.8 parts of composite catalyst, and 2 parts of distilled water) to LBA and polyisocyanate (polymeric MDI Wanhua PM-200) is 100:32:151.8.

[0157] Combination polyethers (parts by weight): 50 parts of 2,2'-diaminobibenzyl polyether polyol A (prepared in Example 5); 18.2 parts of sucrose polyether polyol B (hydroxyl value 380 mg KOH / g); 20 parts of sorbitol polyether polyol C (hydroxyl value 435 mg KOH / g); and 2 parts of glycerol polyether polyol D (hydroxyl value 190 mg KOH / g).

[0158] Surfactant: 3 parts of silicone oil B8545.

[0159] Composite catalyst: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerizing catalyst is potassium acetate. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:4.7:0.5 (mass ratio).

[0160] The preparation method for rigid polyurethane foam is the same as in Example 7.

[0161] Example 16

[0162] Rigid polyurethane foam using the 2,2'-diaminobibenzyl polyether polyol system, raw material composition:

[0163] The mass ratio of the composition (90.2 parts of combined polyether, 3 parts of surfactant, 4.8 parts of composite catalyst, and 2 parts of distilled water) to LBA and polyisocyanate (polymeric MDI Wanhua PM-200) is 100:32:151.8.

[0164] Combination polyethers (parts by weight): 50 parts of 2,2'-diaminobibenzyl polyether polyol A (prepared in Example 5); 34.2 parts of sucrose polyether polyol B (hydroxyl value 380 mg KOH / g); 0 parts of sorbitol polyether polyol C (hydroxyl value 435 mg KOH / g); and 6 parts of glycerol polyether polyol D (hydroxyl value 190 mg KOH / g).

[0165] Surfactant: 3 parts of silicone oil B8545.

[0166] Composite catalyst: The foaming catalyst is pentamethyldiethylenetriamine, the gel catalyst is dimethylcyclohexylamine, and the trimerizing catalyst is potassium acetate. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:4.7:0.5 (mass ratio).

[0167] The preparation method for rigid polyurethane foam is the same as in Example 7.

[0168] The raw material composition and performance parameters of the polyurethane rigid foams prepared in Examples 7-16 are shown in Table 1.

[0169] Table 1: Composition (parts by weight) and performance parameters of polyurethane rigid foam raw materials in Examples 7-16

[0170]

[0171]

[0172] Comparative Example 1

[0173] In Example 11, 2,2'-diaminobibenzyl polyether polyol A was replaced with an equal part by weight of o-toluenediamine polyether polyol A1 (hydroxyl value of 440 mg KOH / g), and other conditions were the same as in Example 11.

[0174] Comparative Example 2

[0175] The polyether composition does not include 2,2'-diaminobibenzyl polyether polyol A. The total weight parts of the polyether composition remain unchanged, as do the weight ratios of sucrose polyether polyol B, sorbitol polyether polyol C, and glycerol polyether polyol D. The composite catalyst is: pentamethyldiethylenetriamine as the foaming catalyst, dimethylcyclohexylamine as the gelling catalyst, and potassium acetate as the trimerizing catalyst. The ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate is 1:6.1:1.5 (mass ratio). Other conditions are the same as in Example 11.

[0176] Comparative Example 3

[0177] The number of molars of the foaming agent remains unchanged, but the LBA foaming agent is replaced with the CP foaming agent, and other conditions are the same as in Example 11.

[0178] Table 2: Properties of rigid polyurethane foams prepared in Comparative Examples 1-3

[0179]

[0180]

[0181] Comparing Comparative Example 1 and Example 11, after replacing the polyether polyol A1, because the structure of polyether polyol A1 lacks freely movable connecting units, it is more brittle and easily breaks under external forces. Furthermore, the close proximity of the two amine groups increases steric hindrance, preventing the hydrogen atoms directly bonded to the nitrogen atoms from reacting completely. The overall group still maintains high reactivity with the NCO groups. In the early stages of polyurethane foam foaming, the degree of crosslinking increases too rapidly, limiting the foam's flow properties, resulting in poor filling effect. Moreover, the rapid increase in crosslinking degree easily increases the shear strength of the foam and the surface material. The number of surface defects was compared. Comparing Comparative Example 2 and Example 11, although the bending performance of the prepared polyurethane foam was improved, the strength performance of the foam was significantly reduced due to the decrease in the number of rigid benzene rings in the overall structure. Furthermore, the lack of amine groups that could react with NCO groups in the early stages of foaming prevented the rapid and efficient formation of a network structure to encapsulate the overflowing blowing agent, resulting in a double loss in thermal conductivity and strength. This comparison indicates that the polyether polyol A in this invention achieves the expected application effect. Comparing Comparative Example 3 and Example 11, the performance of the comparative example after changing the blowing agent system was significantly reduced, especially in terms of thermal conductivity, and the actual application effect could not reach the ideal state. This comparison indicates that the polyurethane foam system in this invention achieves the expected application effect. In summary, the above comparisons show that the polyurethane foam system of this invention, after applying the polyether polyol A, achieves the claimed application effect.

[0182] Although the present invention has been described in detail through the preferred embodiments described above, it should be understood that the above description should not be considered as a limitation of the present invention. Those skilled in the art will understand that modifications or adjustments can be made to the present invention based on the teachings of this specification. These modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A polyether polyol, the general structure of which is shown in Formula I: ###0001### wherein n1, n2, n3 and n4 are independently selected from integers of 1 to 5; and R1 to R4 are selected from the same one of H or methyl. wherein The polyether polyol has a hydroxyl value of 320 to 600 mgKOH / g.

2. The polyether polyol of claim 1, wherein, The polyether polyol has a hydroxyl value of 380 to 440 mgKOH / g.

3. The polyether polyol of claim 2, wherein, The polyether polyol of Formula (I) is prepared by addition reaction of 2,2'-diaminobiphenyl (Formula II) with alkylene oxide under autocatalysis.

4. A process for the preparation of a polyether polyol as claimed in claim 1 or 2 or 3, characterized in that, The alkylene oxide is ethylene oxide, propylene oxide or a homogeneous mixture of ethylene oxide and propylene oxide; and the molar ratio of 2,2'-diaminobiphenyl to alkylene oxide is 1:2 to 10.

5. The preparation method according to claim 4, characterized in that, The alkylene oxide is propylene oxide; and the molar ratio of 2,2'-diaminobiphenyl to alkylene oxide is 1:3 to 8.

6. The production method according to claim 5, wherein The molar ratio of 2,2'-diaminobiphenyl to alkylene oxide is 1:4 to 8.

7. The production method according to claim 6, characterized by, The preparation method specifically comprises: after nitrogen replacement, melting 2,2'-diaminobiphenyl, stirring at 90 to 130°C, mixing with alkylene oxide, reacting at 100 to 150°C, maintaining 0.1 to 0.3 MPa pressure for 1 to 5 h until the pressure no longer decreases, to obtain the polyether polyol.

8. The method of any one of claims 4-7, wherein, The polyurethane rigid foam is prepared by foaming injection mold of a high-pressure foaming machine with components comprising the following parts by weight:

9. A polyurethane rigid foam characterized by, (a) composition 100 parts; (b) foaming agent 20 to 40 parts; (c) isocyanate 120 to 175 parts; The composition comprises combination polyether 86 to 95 parts; surfactant 2 to 5 parts; catalyst 2 to 6 parts; water 1 to 3 parts; the combination polyether is prepared from the polyether polyol of any one of claims 1 to 3 or the polyether polyol A prepared by the preparation method of any one of claims 4 to 8, polyether polyol B prepared by addition reaction of sucrose with propylene oxide, polyether polyol C prepared by addition reaction of sorbitol with propylene oxide, and polyether polyol D prepared by addition reaction of glycerol with propylene oxide.

10. The polyurethane rigid foam of claim 9, wherein, The polyether polyol A has a hydroxyl value of 320 to 600 mgKOH / g. The polyether polyol B has a hydroxyl value of 350 to 410 mgKOH / g. The polyether polyol C has a hydroxyl value of 410 to 470 mgKOH / g. The polyether polyol D has a hydroxyl value of 160 to 220 mgKOH / g. The foaming agent is LBA foaming agent.

11. The polyurethane rigid foam according to claim 9, characterized in that, The isocyanate is polymeric MDI. The isocyanate is polymeric MDI with NCO content of 30 to 32%.

12. The polyurethane rigid foam according to claim 11, characterized in that, The isocyanate is any one or more of polymeric MDI Wanhua PM-200, polymeric MDI Wanhua PM-2010 or polymeric MDI Wanhua PM-400.

13. The polyurethane rigid foam according to claim 12, characterized in that, The polyurethane rigid foam has an isocyanate index of 1.08 to 1.

30.

14. The polyurethane rigid foam according to claim 13, characterized in that, ​ 15. The polyurethane rigid foam according to claim 9, characterized in that, The surface active agent is at least one of alkali metal salt of fatty acid, amine salt of fatty acid, castor oil, ricinoleic acid, and silicone polymer; The catalyst is a composite catalyst, including a foaming catalyst, a gelation catalyst, and a trimerization catalyst.

16. The polyurethane rigid foam according to claim 15, characterized in that, The surface active agent is at least one of silicone oil AK8805, silicone oil AK8830, silicone oil B8525, and silicone oil B8545.

17. The polyurethane rigid foam according to claim 15, characterized in that, The mass ratio of the foaming catalyst to the gelation catalyst and the trimerization catalyst is 1-2:3-7:0.1-2.

18. The polyurethane rigid foam according to claim 15, characterized in that, The foaming catalyst is one or more of pentamethyldiethylenetriamine, tetramethylhexanediamine, and bis-dimethyl ethyl ether; The gelation catalyst is one or more of dimethylbenzylamine, dimethylcyclohexane, and triethylenediamine; The trimerization catalyst is one or more of potassium acetate and 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine.

19. A process for the preparation of the polyurethane rigid foam according to any one of claims 9 to 18, characterized in that, The method comprises the following steps: uniformly mixing a combined polyether, a surface active agent, a catalyst, and water according to a weight ratio to obtain a composition, uniformly mixing the composition and a foaming agent, and filling isocyanate and the composition containing the foaming agent into a mold by using a high-pressure foaming machine to prepare a polyurethane rigid foam.

20. The method of claim 19, wherein, The operation condition of the foaming machine is that the material temperature is 14-18 ℃, and the operation pressure is 100-150 bar.

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