Polyether polyol and preparation method thereof, and polyurethane rigid foam and preparation method thereof

Abstract

The present invention relates to the field of polyurethane materials, and in particular to a polyether polyol and a preparation method thereof, and a polyurethane rigid foam and a preparation method thereof. The polyether polyol of formula (II) formed by using a compound of formula (I) as an initiator has a non-planar and rigid large circular hollow structure, and can form a polyphenyl ring structure in the polyurethane rigid foam skeleton, thereby improving the strength of the foam skeleton. In addition, during the reaction process, especially in the early stage of the reaction, the polyether polyol absorbs a volatilized physical foaming agent, reduces the volatilization rate of the physical foaming agent, and reduces the exchange between the foaming agent and air in the foam cells after the foam is formed, thereby reducing the thermal conductivity of the foam and reducing the thermal conductivity attenuation of the foam, so that the polyurethane rigid foam has low density, low thermal conductivity, high foam strength and excellent anti-aging ability.

Description

Technical Field

[0001] The present invention relates to the field of polyurethane materials, and in particular to a polyether polyol and a preparation method thereof, and a polyurethane rigid foam and a preparation method thereof. Background Art

[0002] As a polymer insulation material, polyurethane rigid foam offers the advantages of low density, low thermal conductivity, and high strength. It effectively fills various spaces and provides support, making it widely used in the casings of appliances such as refrigerators, freezers, and electric water heaters. Currently, the mainstream development of polyurethane rigid foam insulation materials for refrigerators, freezers, and electric water heaters is to reduce the injection volume to reduce costs and enhance market competitiveness. However, low injection volumes result in low pressure density, which places higher demands on the strength of the polyurethane rigid foam. Furthermore, to ensure product quality stability, provide customers with high-quality products, reduce after-sales service costs, and cultivate a positive market reputation, the demand for long-term product stability is becoming increasingly stringent.

[0003] As a thermal insulation material, polyurethane rigid foam itself has drawn greater attention from both environmental and energy-saving perspectives, particularly regarding thermal conductivity, which is closely linked to energy consumption. In polyurethane rigid foam, the gaseous physical blowing agent component accounts for 60-70% of the thermal conductivity, while the polyurethane solid-phase skeleton contributes 20-30%. This means that the lower thermal conductivity of the gaseous physical blowing agent significantly reduces the thermal conductivity of the polyurethane rigid foam. However, the use of physical blowing agents with low thermal conductivity during the preparation process results in low foam strength and susceptibility to aging.

[0004] In summary, while ensuring the low density of polyurethane rigid foam, the market has an urgent demand for polyether polyols to have lower thermal conductivity, higher foam strength and better anti-aging ability. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a polyether polyol and a preparation method thereof, and a polyurethane rigid foam and a preparation method thereof. The polyether polyol of formula (II) formed by using a compound of formula (I) as an initiator has a non-planar and rigid large circular hollow structure, which can form a multi-benzene ring structure in the polyurethane rigid foam skeleton, thereby improving the foam skeleton strength; and during the reaction process, especially in the early stage of the reaction, it adsorbs the volatilized physical foaming agent, reduces the volatility of the physical foaming agent, and reduces the exchange between the foaming agent and air in the foam cells after the foam is formed, thereby reducing the thermal conductivity of the foam and reducing the thermal conductivity attenuation of the foam, so that the polyurethane rigid foam has low density, low thermal conductivity, high foam strength and excellent anti-aging ability.

[0006] In order to achieve the above object of the invention, the technical solution provided by the present invention is as follows:

[0007] A compound, the structural formula of which is shown in formula (I):

[0008]

[0009] The compound represented by formula (I) of the present invention is a doubly bound dibenzotetraaza

[14] cycloolefin dimer, referred to as "DIT-tmtaa".

[0010] On the other hand, the present invention provides a polyether polyol, the structural formula of which is shown in formula (II):

[0011]

[0012] wherein n1, n2, n3 and n4 are each independently any integer from 0 to 4, m1, m2, m3 and m4 are each independently any integer from 0 to 7, and n1, n2, n3, n4, m1, m2, m3 and m4 are not all 0 at the same time.

[0013] The polyether polyol represented by formula (II) of the present invention is referred to as "DIT-tmtaa polyether polyol" for short.

[0014] Furthermore, n1, n2, n3 and n4 are each independently any integer from 1 to 3; and / or m1, m2, m3 and m4 are each independently any integer from 1 to 5.

[0015] Furthermore, the polyether polyol has a hydroxyl value of 100 to 260 mg KOH / g, preferably 135 to 145 mg KOH / g, and a functionality of 2.0 to 4.0, preferably 2.5 to 3.5.

[0016] On the other hand, the present invention provides a method for preparing the above-mentioned compound, comprising reacting a dibenzotetraaza

[14] cycloolefin represented by formula (III) with m-toluenedichloride in the presence of a solvent to obtain;

[0017]

[0018] Optionally, the organic solvent is one or more of acetonitrile, methanol, and acetone;

[0019] Optionally, the mass ratio of the dibenzotetraaza

[14] cycloolefin represented by formula (III) to m-toluenedichloride is 3:1 to 1:1.

[0020] Furthermore, dibenzotetraaza

[14] cycloolefins can be purchased commercially or prepared by conventional methods in the art, for example, by reacting o-phenylenediamine with acetylacetone in the presence of nickel acetate tetrahydrate to prepare an annulene complex, and then dissolving the annulene complex and introducing hydrogen chloride gas to react.

[0021] On the other hand, the present invention provides a method for preparing a polyether polyol, comprising the steps of: subjecting a compound represented by formula (I) to addition polymerization with ethylene oxide and / or propylene oxide to obtain;

[0022]

[0023] Optionally, the reaction temperature of the addition polymerization is 90 to 140°C;

[0024] Optionally, the addition polymerization occurs under a protective atmosphere;

[0025] Optionally, the mass ratio of ethylene oxide to propylene oxide is 1:1.6 to 2.5 (preferably 1:2.0);

[0026] Optionally, the solvent is water;

[0027] Optionally, the addition polymerization further includes filtering and drying steps.

[0028] Wherein, the protective atmosphere in the present invention can be nitrogen.

[0029] Furthermore, the preparation method of the polyether polyol comprises the following steps: dissolving the compound represented by formula (I) in water, replacing the water with nitrogen, adding ethylene oxide, reacting at 90-140° C., stopping the reaction when the pressure remains constant, and obtaining a crude polyether; the crude polyether is filtered and dried to obtain the product.

[0030] The present invention also provides a polyurethane rigid foam, the raw materials for its preparation include any of the above-mentioned polyether polyols or the polyether polyols prepared by the above-mentioned preparation method; preferably, the raw materials for the preparation of the polyurethane rigid foam include the following components in parts by weight:

[0031] (1) Composition: 90-100 parts, preferably 95-100 parts;

[0032] (2) physical foaming agent: 5 to 25 parts, preferably 10 to 18 parts;

[0033] (3) 130 to 160 parts, preferably 130 to 150 parts, of polyisocyanate; wherein the composition comprises a combined polyether, a surfactant, a catalyst, and water in a mass ratio of 88 to 96.6:1.0 to 4.0:1.0 to 5.0:1.5 to 3, and the combined polyether comprises the polyether polyol described above or the polyether polyol obtained by the preparation method.

[0034] In the present invention, the polyisocyanate comprises at least one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, p-phenylene diisocyanate, naphthalene diisocyanate, 1,4-cyclohexane diisocyanate, xylylene diisocyanate, and polymeric MDI, preferably polymeric MDI having an NCO content of 30-32%. Suitable polymeric MDIs include one or more of PM-200, PM-400, and PM-700 from Wanhua Chemical Group Co., Ltd.

[0035] The surfactant used in the present invention is a silicone surfactant, including but not limited to at least one of silicone oil AK8805 and silicone oil AK8830 produced by Nanjing Demeishi Chemical Co., Ltd., and silicone oil B8525 and silicone oil B8545 produced by Evonik Degussa.

[0036] The catalyst used in the present invention is at least one of an amine catalyst and an organotin catalyst, preferably at least two of pentamethyldiethylenetriamine, dimethylcyclohexylamine, potassium acetate and stannous octoate.

[0037] More preferably, the catalyst contains, by weight, 0.1-2.0 parts of pentamethyldiethylenetriamine, 0.4-1.5 parts of dimethylcyclohexylamine and 0.1-0.5 parts of potassium acetate.

[0038] The physical foaming agent used in the present invention is at least one of pentane foaming agents, preferably cyclopentane.

[0039] Furthermore, the composite polyether comprises the following components in parts by weight:

[0040] (a) polyether polyol A, 20 to 55 parts, preferably 20 to 30 parts, of any of the above-mentioned polyether polyols or a polyether polyol prepared by the above-mentioned preparation method;

[0041] (b) polyether polyol B, 15 to 40 parts, preferably 30 to 35 parts, of which the polyether polyol B is prepared by addition reaction of sucrose as an initiator with propylene oxide;

[0042] (c) polyether polyol C, prepared by addition reaction of propylene oxide with sorbitol as an initiator to obtain 20 to 30 parts, preferably 25 to 30 parts, of polyether polyol C;

[0043] (d) polyether polyol D, prepared by addition reaction of diethylene glycol as an initiator with propylene oxide to obtain 5 to 15 parts, preferably 5 to 10 parts, of polyether polyol D;

[0044] Preferably, the hydroxyl value of the polyether polyol B is 350-430 mgKOH / g, and the functionality is 5.7-6.4; the hydroxyl value of the polyether polyol C is 410-485 mgKOH / g, and the functionality is 5.0-7.0; the hydroxyl value of the polyether polyol D is 180-275 mgKOH / g, and the functionality is 1.8-2.5.

[0045] On the other hand, the present invention provides a method for preparing the polyurethane rigid foam, comprising the following steps: mixing raw materials except polyisocyanate, then mixing with polyisocyanate, and foaming to obtain the polyurethane rigid foam.

[0046] During the foaming process, the material temperature is 18-22° C. and the pressure is 110-150 MPa.

[0047] The polyurethane rigid foam involved in the present invention is mainly used for the thermal insulation layer of refrigerators and freezers.

[0048] The technical solution of the present invention has the following advantages:

[0049] 1. Pentane-based physical foaming agents easily absorb the heat released by the polyurethane reaction in the early stages of foaming, easily rupturing the uncured polyurethane rigid foam skeleton during the foaming process and escaping into the atmosphere. This reduces the amount of pentane-based foaming agents, which have low thermal conductivity, with a typical volatilization rate of 3-5%. It also damages the foam cell structure, causing foam to coalesce or shift in cell orientation. Both of these factors increase the foam's thermal conductivity and weaken its strength. The compound of formula (I) provided by the present invention, and the polyether polyol of formula (II) formed using the compound of formula (I) as an initiator, have a non-planar, rigid, large, annular hollow structure that can form a polyphenyl ring structure within the polyurethane rigid foam skeleton, thereby enhancing the foam's strength. Furthermore, during the reaction, especially in the early stages, they absorb volatilized physical foaming agents, reducing their volatilization rate and minimizing the exchange between the foaming agent and air within the cells after foam formation. This reduces the foam's thermal conductivity and thermal conductivity attenuation, resulting in a polyurethane rigid foam with low density, low thermal conductivity, high foam strength, and excellent aging resistance.

[0050] 2. The polyether polyol provided by the present invention has a structure of formula (II). The compound of the initiator structure of formula (I) has four active hydrogen atoms. After reacting with ethylene oxide and / or propylene oxide, the steric hindrance around the active hydrogen atoms increases. At the same time, the structure itself is a large ring, and the active sites are spaced further apart. This results in the polyether polyol being less active than traditional o-toluenediamine (OTDA) polyethers, resulting in a more gentle foam flow and improved fluidity. This improves the filling capacity of the box, the strength of the foam in the box, and the dimensional stability of the foam after aging. Overall, the polyether polyol of the present invention has better overall performance than OTDA polyethers.

[0051] 3. The preparation method of the polyether polyol provided by the present invention is simple, easy to operate, and suitable for industrial production.

[0052] 4. The polyurethane rigid foam of the present invention, by using DIT-TMTAA polyether polyol in combination with a pentane blowing agent, can absorb the pentane blowing agent that volatilizes during the reaction, especially in the early stages of the reaction. This reduces the volatility of the pentane blowing agent and reduces the exchange between the blowing agent and air within the foam cells after foam formation. This reduces the size of the foam cells and makes their size distribution uniform, thereby reducing the foam's thermal conductivity and thermal conductivity attenuation. Due to the non-planar, rigid, large, circular hollow structure of the amine polyether polyol of the present invention, the active sites are widely spaced and have large steric hindrance, resulting in low catalyst activity. Therefore, the polyurethane rigid foam has better fluidity than traditional polyether polyols, resulting in better foam strength in the box and better dimensional stability after foam aging. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 The dibenzotetraaza

[14] cycloolefin synthesized in Example 1 1 HNMR spectrum;

[0055] Figure 2 The DIT-tmtaa synthesized in Example 1 1 HNMR spectrum. DETAILED DESCRIPTION

[0056] The following is a clear and complete description of the technical solution of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0057] If specific experimental procedures or conditions are not specified in the examples, the procedures or conditions described in conventional experimental literature in the field can be followed. Reagents or instruments used without manufacturer's information are commercially available. Raw materials for producing polyether polyols, such as o-phenylenediamine, acetylacetone, and nickel acetate tetrahydrate, can be purchased directly, for example, from Aladdin.

[0058] Polyether polyol A is prepared according to an embodiment of the present invention, using DIT-tmtaa as a raw material and undergoing addition polymerization of ethylene oxide and / or propylene oxide, with a hydroxyl value of 100 to 260 mg KOH / g and a functionality of 2.5 to 4.0.

[0059] Polyether polyol B, prepared by addition reaction of propylene oxide with sucrose as the initiator, has a hydroxyl value of 415 mgKOH / g and a functionality of 6.4. Manufacturer: Wanhua Chemical (Ningbo) Rongwei Polyurethane Co., Ltd.

[0060] Polyether polyol C is prepared by the addition reaction of propylene oxide with sorbitol as the initiator. It has a hydroxyl value of 455 mgKOH / g and a functionality of 5.5. Manufacturer: Wanhua Chemical (Ningbo) Rongwei Polyurethane Co., Ltd.

[0061] Polyether polyol D is prepared by addition reaction of diethylene glycol with propylene oxide. It has a hydroxyl value of 190 mgKOH / g and a functionality of 2.2. Manufacturer: Wanhua Chemical (Ningbo) Rongwei Polyurethane Co., Ltd.

[0062] Surfactant: B8525 (Evonik).

[0063] Physical foaming agent: cyclopentane (CP), Meilong Company.

[0064] Polyisocyanate: Wanhua PM-200 (polymeric MDI).

[0065] The following tests are carried out according to the standard GB / T 12008.3-1989 to test the hydroxyl value and functionality of polyether polyols.

[0066] Example 1

[0067] This embodiment provides a method for preparing polyether polyols. The process flow and preparation method are as follows:

[0068]

[0069]

[0070] (1) Synthesis of dibenzotetraaza

[14] cycloalkene: 0.2 mol of o-phenylenediamine, 0.2 mol of acetylacetone, and 0.1 mol of nickel acetate tetrahydrate were added to 250 mL of ethanol as solvent, and heated under reflux under N2 protection for 50 h. After cooling to room temperature, the mixture was filtered, washed twice with ethanol, and twice with water. The filter cake was dried to obtain an annulene complex. The complex was dissolved in 500 mL of ether, and hydrogen chloride (HCl) gas was introduced at a flow rate of 20 mL / min for half an hour. The mixture was filtered, dried, dissolved in pyridine, poured into water to precipitate a solid, filtered, and dried to obtain dibenzotetraaza

[14] cycloalkene.

[0071] dibenzotetraaza

[14] cycloolefin 1 H NMR spectrum Figure 1 As shown. ESI m / z: 686.5[M + ]. 1 H NMR (300 MHz, CDCl3): δ = 7.42 (m, 4H), 7.33 (m, 2H), 7.22 (m, 2H), 6.93 (m, 2H), 6.84 (m, 2H), 2.37 (s, 2H), 2.26 (s, 2H), 1.31 (s, 12H), proving that dibenzotetraaza

[14] cycloolefin was successfully synthesized.

[0072] (2) Dibenzotetraaza

[14] cycloolefin (290 mg, 0.843 mmol) was dissolved in anhydrous acetonitrile CH3CN (250 mL), and m-toluenedicarboxylic acid chloride (160 mg, 0.788 mmol) dissolved in anhydrous acetonitrile CH3CN (250 mL) was added under N2 atmosphere within 40 minutes. After completion, the reaction was continued at 100-120°C for 3 hours. The reaction mixture was filtered while hot, and the solid particles were stored at 4°C for 12 hours after removing the filtrate. The resulting solid precipitate was collected by filtration and washed several times with cold CH3CN to obtain DIT-tmtaa.

[0073] DIT-TMTAA 1 H NMR spectrum Figure 2 As shown. ESI m / z: 686.5[M + ]. 1 H NMR (300 MHz, CDCl3): δ = 7.69 (m, 4H), 7.42 (m, 2H), 7.22 (m, 2H), 6.93 (m, 2H), 6.84 (m, 2H), 2.26 (s, 2H), 2.07 (s, 2H), proving that DIT-tmtaa was successfully synthesized.

[0074] (3) Water (5098 g, 283.2 mol) and DIT-tmtaa (498.2 g, 0.53 mol) were added to the reactor. After nitrogen replacement, the mixture was slowly heated to 50°C. After 1 hour, stirring was started. The mixture was then slowly heated and the stirring speed was slowly increased. After 6 hours, the mixture was heated to 120°C and maintained for 2 hours. Ethylene oxide (58.3 g, 1.325 mol) was added at a flow rate of 40 g / h, and the pressure was controlled to be ≤0.6 MPa. After the pressure in the reactor remained constant, propylene oxide (153.7 g, 2.65 mol) was added at a flow rate of 80 g / h to continue the autocatalytic reaction. After the pressure in the reactor remained constant, the reaction was stopped to obtain a crude polyether. The crude polyether was filtered and dried to obtain a product, which was recorded as DIT-tmtaa polyether polyol A1. The obtained DIT-tmtaa polyether polyol A1 was tested to have a hydroxyl value of 110 KOH / g and a functionality of 2.5.

[0075] Example 2

[0076] This embodiment provides a method for preparing a polyether polyol, comprising the following steps:

[0077] Water (5098 g, 283.2 mol) and DIT-tmtaa (498.2 g, 0.53 mol) were added to the reactor. After nitrogen replacement, the mixture was slowly heated to 50°C. After 1 hour, stirring was started. Subsequently, the mixture was slowly heated and the stirring speed was slowly increased. After 6 hours, the mixture was heated to 120°C and maintained for 2 hours. Ethylene oxide (69.96 g, 1.58 mol) was added at a flow rate of 40 g / h, and the pressure was controlled to be ≤0.6 MPa during the reaction. After the pressure in the reactor remained constant, propylene oxide (184.44 g, 3.18 mol) was added at a flow rate of 80 g / h to continue the autocatalytic reaction. After the pressure in the reactor remained constant, the reaction was stopped to obtain a crude polyether; the crude polyether was filtered and dried to obtain a product, which was recorded as DIT-tmtaa polyether polyol A2. The hydroxyl value of the obtained DIT-tmtaa polyether polyol A2 was found to be 140 KOH / g and the functionality was 3.0.

[0078] Example 3

[0079] This embodiment provides a method for preparing a polyether polyol, comprising the following steps:

[0080] Water (5098 g, 283.2 mol) and DIT-tmtaa (498.2 g, 0.53 mol) were added to the reactor. After nitrogen replacement, the mixture was slowly heated to 50°C. After 1 hour, stirring was started. Subsequently, the mixture was slowly heated and the stirring speed was slowly increased. After 6 hours, the mixture was heated to 120°C and maintained for 2 hours. Ethylene oxide (81.84 g, 1.86 mol) was added at a flow rate of 40 g / h, and the pressure was controlled to be ≤0.6 MPa during the reaction. After the pressure in the reactor remained constant, propylene oxide (215.76 g, 3.72 mol) was added at a flow rate of 80 g / h to continue the autocatalytic reaction. After the pressure in the reactor remained constant, the reaction was stopped to obtain a crude polyether; the crude polyether was filtered and dried to obtain a product, which was recorded as DIT-tmtaa polyether polyol A3. The hydroxyl value of the obtained DIT-tmtaa polyether polyol A3 was 135KOH / g and the functionality was 3.5.

[0081] Example 4

[0082] This embodiment provides a polyurethane rigid foam using DIT-tmtaa polyether polyol, the raw material composition of which is as follows:

[0083] The mass ratio of the composition to cyclopentane (CP) and polyisocyanate (Wanhua PM-200) is 100:16:148.48. The composition, by weight, consists of 93.2 parts of a composite polyether, 253.0 parts of surfactant B85, 1.7 parts of a catalyst, and 2.1 parts of distilled water. The composite polyether, by weight, consists of 25 parts of polyether polyol A1 (prepared in Example 1), 31.2 parts of polyether polyol B, 25 parts of polyether polyol C, and 12 parts of polyether polyol D. The catalyst consists of pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate, with the mass ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate being 1:4:2.

[0084] The preparation method is as follows: 1) Mix polyether polyol A1, polyether polyol B, polyether polyol C, and polyether polyol D to obtain a composite polyether; uniformly mix pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate to obtain a catalyst. The composite polyether, surfactant, catalyst, and water are then uniformly mixed to obtain a composition; 2) The composition is uniformly mixed with cyclopentane, a physical blowing agent; 3) The product of step 2) is mixed with polyisocyanate in a high-pressure foaming machine to obtain a polyurethane rigid foam. The operating parameters of the high-pressure foaming machine are: material temperature: 18-22°C, pressure: 110-130 MPa. The mixture is overfilled in the mold at 115%, and cured for 200 seconds. The mold is then opened to remove the finished polyurethane rigid foam.

[0085] Example 5

[0086] This embodiment provides a polyurethane rigid foam using DIT-tmtaa polyether polyol, the raw material composition of which is as follows:

[0087] The mass ratio of the composition to cyclopentane (CP) and polyisocyanate (Wanhua PM-200) is 100:16:148.48. The composition, by weight, consists of 92.4 parts of a composite polyether, 253.0 parts of surfactant B85, 2.5 parts of a catalyst, and 2.1 parts of distilled water. The composite polyether, by weight, consists of 15 parts of polyether polyol A2 (prepared in Example 2), 40.4 parts of polyether polyol B, 25 parts of polyether polyol C, and 12 parts of polyether polyol D. The catalyst consists of pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate, with the mass ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate being 1:5:2.

[0088] The preparation method is as follows: 1) Mix polyether polyol A2, polyether polyol B, polyether polyol C, and polyether polyol D to obtain a composite polyether; uniformly mix pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate to obtain a catalyst. The composite polyether, surfactant, catalyst, and water are then uniformly mixed to obtain a composition; 2) The composition is uniformly mixed with cyclopentane, a physical blowing agent; 3) The product of step 2) is mixed with polyisocyanate in a high-pressure foaming machine to obtain a polyurethane rigid foam. The operating parameters of the high-pressure foaming machine are: material temperature: 18-22°C, pressure: 110-130 MPa. The mixture is overfilled in the mold at 115%, and cured for 200 seconds. The mold is then opened to remove the finished polyurethane rigid foam.

[0089] Example 6

[0090] This embodiment provides a polyurethane rigid foam using DIT-tmtaa polyether polyol, the raw material composition of which is as follows:

[0091] The mass ratio of the composition to cyclopentane (CP) and polyisocyanate (Wanhua PM-200) is 100:16:148.48. The composition, by weight, consists of 92.9 parts of a composite polyether, 253.0 parts of surfactant B85, 2.0 parts of a catalyst, and 2.1 parts of distilled water. The composite polyether, by weight, consists of 25 parts of polyether polyol A2 (prepared in Example 2), 34.9 parts of polyether polyol B, 25 parts of polyether polyol C, and 8 parts of polyether polyol D. The catalyst consists of pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate, with the mass ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate being 1:4:2.

[0092] The preparation method is as follows: 1) Mix polyether polyol A2, polyether polyol B, polyether polyol C, and polyether polyol D to obtain a composite polyether; uniformly mix pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate to obtain a catalyst. The composite polyether, surfactant, catalyst, and water are then uniformly mixed to obtain a composition; 2) The composition is uniformly mixed with cyclopentane, a physical blowing agent; 3) The product of step 2) is mixed with polyisocyanate in a high-pressure foaming machine to obtain a polyurethane rigid foam. The operating parameters of the high-pressure foaming machine are: material temperature: 18-22°C, pressure: 110-130 MPa. The mixture is overfilled in the mold at 115%, and cured for 200 seconds. The mold is then opened to remove the finished polyurethane rigid foam.

[0093] Example 7

[0094] This embodiment provides a polyurethane rigid foam using DIT-tmtaa polyether polyol, the raw material composition of which is as follows:

[0095] The mass ratio of the composition to cyclopentane (CP) and polyisocyanate (Wanhua PM-200) is 100:16:148.48. The composition, by weight, consists of 93.2 parts of a composite polyether, 253.0 parts of surfactant B85, 1.7 parts of a catalyst, and 2.1 parts of distilled water. The composite polyether, by weight, consists of 35 parts of polyether polyol A2 (prepared in Example 2), 28.2 parts of polyether polyol B, 25 parts of polyether polyol C, and 5 parts of polyether polyol D. The catalyst consists of pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate, with the mass ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate being 1:3:2.

[0096] The preparation method is as follows: 1) Mix polyether polyol A2, polyether polyol B, polyether polyol C, and polyether polyol D to obtain a composite polyether; uniformly mix pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate to obtain a catalyst. The composite polyether, surfactant, catalyst, and water are then uniformly mixed to obtain a composition; 2) The composition is uniformly mixed with cyclopentane, a physical blowing agent; 3) The product of step 2) is mixed with polyisocyanate in a high-pressure foaming machine to obtain a polyurethane rigid foam. The operating parameters of the high-pressure foaming machine are: material temperature: 18-22°C, pressure: 110-130 MPa. The mixture is overfilled in the mold at 115%, and cured for 200 seconds. The mold is then opened to remove the finished polyurethane rigid foam.

[0097] Example 8

[0098] This embodiment provides a polyurethane rigid foam using DIT-tmtaa polyether polyol, the raw material composition of which is as follows:

[0099] The mass ratio of the composition to cyclopentane (CP) and polyisocyanate (Wanhua PM-200) is 100:16:148.48. The composition, by weight, consists of 92.5 parts of a composite polyether, 253.0 parts of surfactant B85, 2.4 parts of a catalyst, and 2.1 parts of distilled water. The composite polyether, by weight, consists of 25 parts of polyether polyol A3 (prepared in Example 3), 36.5 parts of polyether polyol B, 25 parts of polyether polyol C, and 6 parts of polyether polyol D. The catalyst consists of pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate, with the mass ratio of pentamethyldiethylenetriamine:dimethylcyclohexylamine:potassium acetate being 1:5:2.

[0100] The preparation method is as follows: 1) Polyether polyol A3, polyether polyol B, polyether polyol C, and polyether polyol D are mixed to obtain a composite polyether; pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate are mixed to obtain a catalyst. The composite polyether, surfactant, catalyst, and water are mixed to obtain a composition; 2) The composition is mixed with cyclopentane, a physical blowing agent; 3) The product of step 2) is mixed with polyisocyanate in a high-pressure foaming machine to obtain a polyurethane rigid foam. The operating parameters of the high-pressure foaming machine are: material temperature: 18-22°C, pressure: 110-130 MPa. The mixture is overfilled in the mold at 115%, and cured for 200 seconds. The mold is then opened to remove the finished polyurethane rigid foam.

[0101] Comparative Example 1

[0102] This comparative example provides a polyurethane rigid foam using DIT-tmtaa polyether polyol, the raw material composition of which is as follows:

[0103] The mass ratio of the composition to cyclopentane (CP) and polyisocyanate (Wanhua PM-200) is 100:16:148.48. The composition, by weight, consists of 92.1 parts of a composite polyether, 253.0 parts of surfactant B85, 2.8 parts of a catalyst, and 2.1 parts of distilled water. The composite polyether, by weight, consists of 47.1 parts of polyether polyol B, 30 parts of polyether polyol C, and 5 parts of polyether polyol D. The catalyst consists of pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate, with the mass ratio of pentamethyldiethylenetriamine: dimethylcyclohexylamine: potassium acetate being 1:6:2.

[0104] The preparation method is as follows: 1) Mix polyether polyol B, polyether polyol C, and polyether polyol D to obtain a composite polyether; uniformly mix pentamethyldiethylenetriamine, dimethylcyclohexylamine, and potassium acetate to obtain a catalyst. The composite polyether, surfactant, catalyst, and water are then uniformly mixed to obtain a composition; 2) The composition is uniformly mixed with cyclopentane, a physical blowing agent; 3) The product of step 2) is mixed with polyisocyanate in a high-pressure foaming machine to obtain a polyurethane rigid foam. The operating parameters of the high-pressure foaming machine are: material temperature: 18-22°C, pressure: 110-130 MPa. The mixture is overfilled in the mold at 115%, and cured for 200 seconds. The mold is then opened to remove the finished polyurethane rigid foam.

[0105] Test Case

[0106] The performance test of the polyurethane rigid foam prepared in each embodiment and comparative example is as follows:

[0107] The flow index test method is as follows: Prepare a mold with dimensions of 30mm x 50mm x 1100mm (length x width x height) at 45°C. Inject a certain amount of mixture from the bottom of the mold until the mold is completely filled (weight x g). The mold height is 1100mm. Divide the mold height by x to obtain the flow index. Foam core density is tested according to GB / T 6343-2009; foam thermal conductivity is tested according to GB / T 10295-2008; foam compressive strength is tested according to GB / T 8813-2008; and foam dimensional stability is tested according to GB / T 8811-2008. Test conditions: Test at 0.1 MPa for 30 minutes. Dimensional stability is calculated based on the volume change before and after compression. Observe the number of surface defects, and record the number of defects with a diameter ≥ 3 cm.

[0108] The results are shown in Table 1.

[0109] Table 1 Properties of polyurethane rigid foam

[0110]

[0111] Compared with Comparative Example 1, the polyurethane rigid foams prepared in each embodiment of the present invention have significantly improved compression strength, significantly reduced deformation rate, significantly reduced number of surface defects, significantly improved flow index, and reduced thermal conductivity, indicating that these polyurethane rigid foams have low thermal conductivity, high foam strength, good fluidity and excellent anti-aging ability, especially Example 8. The foam core density of the polyurethane rigid foam of the present invention is 32-33 kg / m 3 This shows that these polyurethane rigid foams also have low density properties.

[0112] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A polyether polyol, characterized in that Its structural formula is shown in formula (II): (II) wherein n1, n2, n3 and n4 are each independently any integer from 0 to 4, m1, m2, m3 and m4 are each independently any integer from 0 to 7, and n1, n2, n3, n4, m1, m2, m3 and m4 are not all 0 at the same time.

2. The polyether polyol according to claim 1, wherein n1, n2, n3 and n4 are each independently any integer from 1 to 3; and / or m1, m2, m3 and m4 are each independently any integer from 1 to 5.

3. The polyether polyol according to claim 1 or 2, characterized in that The polyether polyol has a hydroxyl value of 100 to 260 mg KOH / g and a functionality of 2.0 to 4.

0.

4. The polyether polyol according to claim 3, characterized in that The polyether polyol has a hydroxyl value of 135 to 145 mg KOH / g and a functionality of 2.5 to 3.

5.

5. A method for preparing a polyether polyol, characterized in that: The method comprises the following steps: subjecting a compound represented by formula (I) to addition polymerization with ethylene oxide and / or propylene oxide in the presence of a solvent to obtain a product; （I）。 6. The method for preparing polyether polyol according to claim 5, wherein The reaction temperature of the addition polymerization is 90-140°C.

7. The method for preparing polyether polyol according to claim 5, wherein The addition polymerization takes place under a protective atmosphere.

8. The method for preparing polyether polyol according to claim 5, wherein The mass ratio of ethylene oxide to propylene oxide is 1:1.6-2.

5.

9. The method for preparing polyether polyol according to claim 5, wherein The solvent is water.

10. The method for preparing polyether polyol according to claim 5, wherein The addition polymerization further includes filtering and drying steps.

11. The method for preparing polyether polyol according to claim 5, wherein The preparation method of the polyether polyol comprises the following steps: dissolving the compound represented by formula (I) in water, replacing the water with nitrogen, adding ethylene oxide, reacting at 90-140°C, stopping the reaction when the pressure remains constant, and obtaining a crude polyether; and filtering and drying the crude polyether to obtain the product.

12. The method for preparing polyether polyol according to claim 5, wherein The method for preparing the compound represented by formula (I) is characterized by comprising reacting the dibenzotetraaza[14]cycloolefin represented by formula (III) with m-toluene dicarbonyl chloride in the presence of an organic solvent to obtain; (III).

13. The method for preparing polyether polyol according to claim 12, characterized in that: The organic solvent is one or more of acetonitrile, methanol and acetone.

14. The method for preparing polyether polyol according to claim 12, wherein: The mass ratio of the dibenzotetraaza[14]cycloolefin represented by formula (III) to m-toluenedichloride is 3:1 to 1:

1.

15. A polyurethane rigid foam, characterized in that: The raw materials for its preparation include the polyether polyol described in any one of claims 1 to 4 or the polyether polyol prepared by the preparation method described in any one of claims 5 to 14.

16. The polyurethane rigid foam according to claim 15, characterized in that The raw materials for preparing the polyurethane rigid foam include the following components in parts by weight: (1) Composition: 90-100 parts; (2) Physical foaming agent: 5-25 parts; (3) 130-160 parts of polyisocyanate; wherein the composition comprises a combined polyether, a surfactant, a catalyst and water in a mass ratio of 88-96.6:1.0-4.0:1.0-5.0:1.5-3, and the combined polyether comprises the polyether polyol according to any one of claims 1-4 or the polyether polyol prepared by the preparation method according to any one of claims 5-14.

17. The polyurethane rigid foam according to claim 16, characterized in that The raw materials for preparing the polyurethane rigid foam include the following components in parts by weight: (1) Composition: 95-100 parts; (2) Physical foaming agent: 10-18 parts; (3) 130-150 parts of polyisocyanate; wherein the composition comprises a combined polyether, a surfactant, a catalyst and water in a mass ratio of 88-96.6:1.0-4.0:1.0-5.0:1.5-3, and the combined polyether comprises the polyether polyol according to any one of claims 1-4 or the polyether polyol prepared by the preparation method according to any one of claims 5-14.

18. The polyurethane rigid foam according to claim 16 or 17, characterized in that The composite polyether comprises the following components in parts by weight: (a) polyether polyol A, 20-55 parts of the polyether polyol according to any one of claims 2 to 4 or the polyether polyol prepared by the preparation method according to claim 6 or 7; (b) polyether polyol B, 15-40 parts of polyether polyol B prepared by addition reaction of sucrose as an initiator with propylene oxide; (c) polyether polyol C, prepared by addition reaction of sorbitol as an initiator with propylene oxide to obtain 20 to 30 parts of polyether polyol C; (d) Polyether polyol D: 5 to 15 parts of polyether polyol D are prepared by addition reaction of diethylene glycol as an initiator with propylene oxide.

19. The polyurethane rigid foam according to claim 18, characterized in that The composite polyether comprises the following components in parts by weight: (a) polyether polyol A, 20-30 parts of the polyether polyol according to any one of claims 2 to 4 or the polyether polyol prepared by the preparation method according to claim 6 or 7; (b) polyether polyol B, 30-35 parts of polyether polyol B prepared by addition reaction of sucrose as an initiator with propylene oxide; (c) polyether polyol C, prepared by addition reaction of sorbitol as an initiator with propylene oxide to obtain 25-30 parts of polyether polyol C; (d) Polyether polyol D: 5 to 10 parts of polyether polyol D are prepared by addition reaction of diethylene glycol as an initiator with propylene oxide.

20. The polyurethane rigid foam according to claim 19, characterized in that The polyether polyol B has a hydroxyl value of 350-430 mgKOH / g and a functionality of 5.7-6.4; the polyether polyol C has a hydroxyl value of 410-485 mgKOH / g and a functionality of 5.0-7.0; the polyether polyol D has a hydroxyl value of 180-275 mgKOH / g and a functionality of 1.8-2.

5.

21. A method for preparing the polyurethane rigid foam according to any one of claims 15 to 20, comprising the steps of: mixing raw materials other than polyisocyanate, then mixing with polyisocyanate, and foaming to obtain the polyurethane rigid foam.

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