A hyperbranched polyester amide polyol, its method of preparation and use in rigid polyurethane foam

Abstract

The application discloses a kind of hyperbranched polyester amide polyols and preparation method and application in rigid polyurethane foam, it is related to polyurethane material technical field, high hydroxyl value, high functionality, low viscosity hyperbranched polyester amide polyols are synthesized using simple one-pot melt polymerization method, and it is applied in the preparation of rigid polyurethane foam.Utilize the three-dimensional branched structure of hyperbranched polyester amide polyols to reduce the viscosity of combination material, while through a large number of end group functional groups to enhance crosslinking density to enhance compression strength;Through the control of acid anhydride containing benzene ring and not containing benzene ring, the viscosity and rigidity of hyperbranched polyester amide polyols are synergistically adjusted;By introducing polyethylene glycol at one end of hyperbranched structure, the viscosity of polyester amide polyol is further reduced, while the compatibility of polyester amide polyol and commercial polyol is improved;With water to replace part of physical blowing agent, while ensuring environmental protection, control molecular chain urea group distribution, avoid foam embrittlement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane materials, in particular to a hyperbranched polyester amide polyol, a preparation method thereof and application thereof in rigid polyurethane foam. BACKGROUND

[0002] Foamed polyurethane materials have the advantages of low density, light weight, low thermal conductivity, good cushioning, sound absorption and heat insulation, and are widely used in the fields of transportation industry, packaging and building industry, sports goods and shoe materials. The conventional polyurethane foam material has insufficient bearing capacity and cannot adapt to high load working conditions. At the same time, the viscosity of the traditional polyol combination material is too large to meet the use requirements of the foaming equipment. The conventional methods for improving the compressive strength of polyurethane foam mainly include particle reinforcement, fiber reinforcement and structural reinforcement, but all have certain defects:

[0003] Particle reinforcement technology: the Chinese patent application with publication number CN1900132A discloses a high-strength rigid polyurethane foam, which adds nano inorganic materials to improve the mechanical properties of the material to a certain extent, but this particle reinforcement method will reduce the toughness of the rigid foam and greatly increase the viscosity of the polyol combination material system, making it difficult to disperse the particles and causing foaming difficulties, which cannot meet the process requirements. The Chinese patent with publication number CN103012738B discloses a preparation method of modified fly ash microsphere reinforced rigid polyurethane foam material, which improves the mechanical properties and heat resistance of the polyurethane foam material, reduces the production cost, and realizes the effective application of fly ash. However, fly ash as the main particle reinforcement will also increase the viscosity of the polyol combination material system, which is not conducive to industrialized production.

[0004] Fiber reinforcement technology: the Chinese patent application with publication number CN103819651A discloses a high-strength rigid polyurethane foam material, which obtains a rigid polyurethane foam material with improved strength and dimensional stability by adding a composite reinforcing material. However, the particles in the composite material not only reduce the toughness of the foam and increase the viscosity of the polyol combination material, but also increase the density of the foam product, making it unable to meet the lightweight requirements. In addition, the particles or fibers introduced in this physical reinforcement method may have an adverse effect on the normal operation of the foaming equipment.

[0005] Structure reinforcement: conventional structure reinforcement mostly uses linear polymers as the main material, which is generally prepared by reacting polyether (or polyester) polyols with a high hydroxyl value, a high number of functional groups and a low molecular weight, and polyisocyanate. The obtained foam plastic has a large hardness, a high compressive strength, good dimensional stability and temperature resistance due to the high number of network structures in the molecule (i.e. a large number of crosslinking points and high density). The crosslinking polyol usually has a high viscosity, which significantly increases the viscosity of the polyol combination, making it difficult to mix with low-viscosity isocyanate, resulting in uneven rigid foam, affecting the apparent quality of the foam product, and the high-viscosity polyol combination cannot meet the extraction and atomization requirements of the foaming equipment, and cannot meet the process requirements in large-scale industrial production. At the same time, increasing the intrinsic crosslinking degree of the material often leads to an increase in the brittleness of the material system, a decrease in the bending performance and impact resistance, and difficulty in meeting the use requirements of the actual scene. Therefore, there is a contradiction between the mechanical properties and the foaming process of the conventional polyurethane material using linear polymers as the main body, and a new material structure design idea needs to be developed for polyurethane materials to achieve a balanced development of their mechanical properties and process properties.

[0006] In traditional hyperbranched polyols, the introduction of benzene rings often leads to an increase in molecular chain rigidity, an increase in entanglement, and a significant increase in viscosity. For example, the Chinese invention patent with the publication number CN113024441B provides a kind of hyperbranched additive, the benzene ring in the molecular chain leads to poor molecular motion ability, and tends to form a solid. For another example, the Chinese invention patent application with the publication number CN118852594A provides a kind of hyperbranched polyester polyol, which only has one benzene ring at the end, and is controlled by other groups in the molecular chain, which has limited effect on strength improvement.

[0007] Therefore, through molecular structure design, a kind of hyperbranched polyol with high hydroxyl value, high functionality and low viscosity is synthesized and applied in the preparation of load-bearing / thermal insulation integrated polyurethane foam material, which is the main technical problem faced by the present application. SUMMARY

[0008] In view of this, the purpose of the present application is to provide a kind of hyperbranched polyester amide polyol and its preparation method and application in rigid polyurethane foam, aiming to improve the load-bearing capacity of polyurethane foam material, while reducing the viscosity of polyol combination, meeting the process requirements of foaming equipment. To achieve the above purpose, the present application provides a kind of load-bearing / thermal insulation integrated polyurethane foam material containing hyperbranched structure, and discloses a kind of preparation method of polyester amide hyperbranched polyol with high hydroxyl value, high functionality and low viscosity, and introduces it into polyurethane foam material, combines with foam formula design, effectively improves the compressive strength of polyurethane foam material, and improves the comprehensive performance of foam, which can be applied to the thermal insulation scene with high load-bearing working condition.

[0009] The object of the present application is achieved by the following technical solutions.

[0010] <First aspect>

[0011] A hyperbranched polyester amide polyol, the structural general formula is:

[0012]

[0013] wherein each R is independently selected from R1 or R2, (N-methylpropionamide group), (N-methylphthalimide group);

[0014] wherein m, n, x, y correspond to the shared starting position of the repeating functional groups, x = 1 ~ 10, y = 1 ~ 10, z = 1 ~ 20, m = 1 ~ 10, n = 1 ~ 10.

[0015] As an embodiment, in the structural formula of the hyperbranched polyester amide polyol, the R1 and R2 groups have a molar relationship: .

[0016] As an embodiment, in the structural formula of the hyperbranched polyester amide polyol, the R1 and R2 groups have a molar relationship: .

[0017] As an embodiment, in the structural formula of the hyperbranched polyester amide polyol, the molar ratio of R1 and R2 groups is 1 ~ 4 : 1.

[0018] As an embodiment, the functionality of the hyperbranched polyester amide polyol is 7.5 ~ 16, the hydroxyl value is 200 ~ 420 mgKOH·g -1 , the viscosity is 500 ~ 1500 mPa·s, the molecular weight is 800 ~ 5000 g / mol, the branching degree is 0.15 ~ 0.66, and the moisture content is ≤0.8%.

[0019] As an embodiment, the functionality of the hyperbranched polyester amide polyol is 7.9 ~ 10.4, the hydroxyl value is 320 ~ 400 mgKOH·g -1 , the viscosity is 600 ~ 1200 mPa·s, the molecular weight is 1158 ~ 2200 g / mol, the branching degree is 0.52 ~ 0.54, and the moisture content is ≤0.6%.

[0020] As an embodiment, the functionality of the hyperbranched polyester amide polyol is 7.9 ~ 9.2, the hydroxyl value is 320 ~ 400 mgKOH·g -1, a viscosity of 600-1000 mPa-s, a molecular weight of 1158-1500 g / mol, a degree of branching of 0.52-0.54, and a moisture content of <0.6%.

[0021] As one embodiment, the hyperbranched polyester amide polyol has a functionality of 7.9-9.2, a hydroxyl number of 320-400 mgKOH-g -1 , a viscosity of 700-1000 mPa-s, a molecular weight of 1342-1500 g / mol, a degree of branching of 0.53-0.54, and a moisture content of <0.5%.

[0022] As one embodiment, the hyperbranched polyester amide polyol has a functionality of 8-9.2, a hydroxyl number of 320-380 mgKOH-g -1 , a viscosity of 700-900 mPa-s, a molecular weight of 1340-1470 g / mol, a degree of branching of 0.53-0.54, and a moisture content of <0.5%.

[0023] In some embodiments, the hyperbranched polyester amide polyol has a functionality of 8.3-9.2, a hydroxyl number of 340-380 mgKOH-g -1 , a viscosity of 700-800 mPa-s, a molecular weight of 1342 g / mol, a degree of branching of 0.54, and a moisture content of 0.5%.

[0024] In some embodiments, the hyperbranched polyester amide polyol has a functionality of 8-9, a hydroxyl number of 320-360 mgKOH-g -1 , a viscosity of 800-900 mPa-s, a molecular weight of 1470 g / mol, a degree of branching of 0.53, and a moisture content of 0.4%.

[0025] In some embodiments, the hyperbranched polyester amide polyol has a functionality of 8.3-9.2, a hydroxyl number of 340-380 mgKOH-g -1 , a viscosity of 700-800 mPa-s, a molecular weight of 1340 g / mol, a degree of branching of 0.54, and a moisture content of 0.5%.

[0026] In some embodiments, the hyperbranched polyester amide polyol has a functionality of 7.9-8.7, a hydroxyl number of 340-400 mgKOH-g -1 , a viscosity of 900-1000 mPa-s, a molecular weight of 1500 g / mol, a degree of branching of 0.53, and a moisture content of 0.5%.

[0027] In some embodiments, the hyperbranched polyester amide polyol has a functionality of 8.3-9.0, a hydroxyl value of 335-375 mgKOH.g -1 , a viscosity of 600-700 mPa.s, a molecular weight of 1158 g / mol, a branching degree of 0.52, and a moisture content of 0.6%.

[0028] In some embodiments, the hyperbranched polyester amide polyol has a functionality of 9.5-10.4, a hydroxyl value of 360-400 mgKOH.g -1 , a viscosity of 1000-1200 mPa.s, a molecular weight of 2200 g / mol, a branching degree of 0.54, and a moisture content of 0.6%.

[0029] <Second aspect>

[0030] A method for preparing a hyperbranched polyester amide polyol, comprising the following steps:

[0031] Under a protective atmosphere, the aliphatic alcohol amine monomer, the acid anhydride, and the monomethyl ether polyethylene glycol are stirred and reacted at a first temperature for a first time, and then are continuously stirred and reacted at a second temperature for a second time, and are cooled to room temperature to obtain the hyperbranched polyester amide polyol.

[0032] As an embodiment, the molar ratio of the aliphatic alcohol amine monomer, the acid anhydride, and the monomethyl ether polyethylene glycol is 1:1:0.1-0.125.

[0033] In some embodiments, the molar ratio of the acid anhydride and the monomethyl ether polyethylene glycol is 8:1.

[0034] As an embodiment, the aliphatic alcohol amine monomer is one or more of aminoethanediol, aminopropanediol, aminobutanediol, aminopentanediol, N,N-bis(2-hydroxyethyl)ethylenediamine, N,N-bis(2-hydroxymethyl)ethylenediamine, N,N-bis(2-hydroxymethyl)methylenediamine, N,N-bis(2-hydroxyethyl)methylenediamine, and tris(hydroxymethyl)aminomethane.

[0035] In some embodiments, the aliphatic alcohol amine monomer is aminopropanediol.

[0036] As an embodiment, the acid anhydride is an acid anhydride with a benzene ring and / or an acid anhydride without a benzene ring.

[0037] As an embodiment, the acid anhydride with a benzene ring is 1,2,4-benzene tricarboxylic anhydride.

[0038] As an embodiment, the acid anhydride without benzene ring is one or more of succinic anhydride, glutaric anhydride, 1,2,4-cyclohexane tricarboxylic anhydride, 2,5-dihydroxy-2,5-dioxo-3-furancarboxylic acid, cis-aconitic anhydride, 2-(2'-carboxyethyl)maleic anhydride, 2,5-dihydroxy-4-methyl-2,5-dioxo-3-furancarboxylic acid, α-methyl-cis-aconitic anhydride, 2,5-dihydroxy-4-methyl-2,5-dioxo-3-furancarboxylic acid.

[0039] As an embodiment, the acid anhydride with benzene ring in the acid anhydride is 20% to 100% in mole fraction in the acid anhydride.

[0040] As an embodiment, the acid anhydride without benzene ring in the acid anhydride is 50% to 100% in mole fraction in the acid anhydride.

[0041] As an embodiment, the mole ratio of the acid anhydride with benzene ring and the acid anhydride without benzene ring in the acid anhydride is 1:1 to 4.

[0042] In some embodiments, the acid anhydride includes 1,2,4-benzene tricarboxylic anhydride.

[0043] In some embodiments, the acid anhydride is 1,2,4-benzene tricarboxylic anhydride and succinic anhydride.

[0044] As an embodiment, the first temperature is 90 to 120℃ and the first time is 0.5 to 4h.

[0045] As an embodiment, the second temperature is 120 to 240℃ and the second time is 1 to 8h.

[0046] As an embodiment, the second time is 1 to 4h.

[0047] In some embodiments, the first temperature is 100℃ and the first time is 1.5h.

[0048] In some embodiments, the second temperature is 220 to 240℃ and the second time is 1 to 4h.

[0049] As an embodiment, the protective atmosphere is nitrogen.

[0050] <Third aspect>

[0051] The present application provides a preparation method of rigid polyurethane foam containing the above hyperbranched polyester amide polyol, comprising the following steps:

[0052] Mixing the A component and performing first stirring to a uniform state to obtain a polyol combination material;

[0053] adding polyisocyanate to the polyol composition and stirring for a second time at the third temperature to obtain a PU slurry;

[0054] injecting the PU slurry into a preheated mold for foaming, then treating the PU slurry together with the mold at a fourth temperature and cooling to room temperature to obtain the rigid polyurethane foam;

[0055] The component A comprises, by mass, 70-120 parts of hyperbranched polyester amide polyol, 20-55 parts of polyether polyol, 0.6-5.0 parts of catalyst, 1-3 parts of foam stabilizer, 5-15 parts of cross-linking agent, 0.5-20 parts of physical foaming agent, 0.5-20 parts of chemical foaming agent, 5-15 parts of flame retardant, and 100-150 parts of polyisocyanate.

[0056] The mass ratio of the polyisocyanate to the polyol combination is 1-1.2:1.

[0057] As an embodiment, the functionality of the hyperbranched polyester amide polyol is 7.9-9.2, and the hydroxyl value is 320-400 mgKOH·g -1 , viscosity is 600~1000 mPa·s, molecular weight is 1158~1500 g / mol, degree of branching is 0.52~0.54, and moisture content is ≤0.6%.

[0058] As an embodiment, the mass ratio of the hyperbranched polyester amide polyol to the polyether polyol is 7-12:3.

[0059] In some embodiments, the mass ratio of the hyperbranched polyester amide polyol to the polyether polyol is 7:3.

[0060] In some embodiments, the mass ratio of the hyperbranched polyester amide polyol to the polyether polyol is 4:1.

[0061] As an embodiment, the mass ratio of the physical foaming agent to the chemical foaming agent is 1.5~5:1.

[0062] In some embodiments, the mass ratio of the physical foaming agent to the chemical foaming agent is 25:9.

[0063] In some embodiments, the mass ratio of the physical foaming agent to the chemical foaming agent is 7.78:1.56.

[0064] In some embodiments, the mass ratio of the physical foaming agent to the chemical foaming agent is 3.23:2.15.

[0065] As an embodiment, the functionality of the polyether polyol is 4.6-5.8 and the hydroxyl value is 360-400 mgKOH·g -1, viscosity 10000~12500 mPa-s.

[0066] In some embodiments, the polyether polyol has a functionality of 4.6~5.8, a hydroxyl value of 360~400 mg KOH-g -1 , viscosity 10000~12500 mPa-s.

[0067] As an embodiment, the catalyst is one or more of tetramethylethylenediamine, triethanolamine, triethylenediamine, N,N-dimethylcyclohexylamine, 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine, pentamethyldiethylene triamine, triethylene diamine, A-33, PT303, stannous octoate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin diacetate, MB20, butyl titanate.

[0068] In some embodiments, the catalyst is pentamethyldiethylene triamine and dibutyltin dilaurate.

[0069] As an embodiment, the foam stabilizer is one or more of M-8805, M-8808, M-8809, M-8815, M-8860, M-88308, M-88310, M-88108, M-88109, M-88716, M-88719.

[0070] In some embodiments, the foam stabilizer is M-88308.

[0071] As an embodiment, the crosslinking agent is one or more of glycerol, pentaerythritol, sorbitol, sucrose, polyether 403.

[0072] In some embodiments, the crosslinking agent is polyether 403.

[0073] As an embodiment, the physical blowing agent is one or more of HFC-245fa, HFC-134a, HFC-365mfc, HFC-227ea, HCFC-141b, CFC-11, cyclopentane, n-pentane, cyclo-iso-pentane, 3,3-trifluoropropene.

[0074] In some embodiments, the physical blowing agent is monofluorodichloroethane.

[0075] As an embodiment, the chemical blowing agent is water.

[0076] As an embodiment, the flame retardant is one or more of TCPP, TCEP, and TEP.

[0077] In some embodiments, the flame retardant is tris(2-chloropropyl) phosphate.

[0078] As an embodiment, the -NCO content of the polyisocyanate is 30% to 35%, the functionality is 2.5 to 2.9, the viscosity is 150 to 250 mPa•s, and the density is 1.20 to 1.30 g•cm -3 .

[0079] As an embodiment, the stirring speed of the first stirring is 800 to 2000 r / min, and the stirring time is 20 to 50 min.

[0080] In some embodiments, the stirring speed of the first stirring is 1000 r / min, and the stirring time is 30 min.

[0081] As an embodiment, the stirring speed of the second stirring is 800 to 2000 r / min, and the stirring time is 10 to 30 s.

[0082] In some embodiments, the stirring speed of the second stirring is 1000 r / min, and the stirring time is 15 s.

[0083] As an embodiment, the third temperature is 25 to 35℃.

[0084] As an embodiment, the mold preheating temperature is 40 to 90℃.

[0085] As an embodiment, the fourth temperature is 60 to 120℃, and the treatment time is 12 to 48 h.

[0086] Compared with the prior art, the present application has the following beneficial effects:

[0087] The present application provides a hyperbranched polyester amide polyol and a preparation method and application thereof in rigid polyurethane foam. Through molecular structure design, a high-hydroxyl-value, high-functionality, and low-viscosity polyester amide hyperbranched polyol is synthesized by a simple one-pot melt polymerization method, and is introduced into a polyurethane foam material, so that the polyurethane foam has a load / thermal insulation integrated function, improves the comprehensive performance of the material, and meets the foaming equipment requirements. The synthesis method has wide raw material sources and low cost, has certain advantages in time and cost, and is easy to realize large-scale industrialized preparation. The main advantages are as follows:

[0088] 1) Simultaneous adjustment of viscosity and rigidity of hyperbranched polyester amide polyol

[0089] Due to the structural rigidity of the benzene ring, the structural strength of the foam material can be improved by introducing the benzene ring structure. Further, the performance of the required polyurethane foam material is further adjusted by adjusting the ratio and type of the required monomers of the hyperbranched polyester amide polyol.

[0090] The application realizes the regulation of N-methyl propionamide group and N-methyl phthalimide group by regulating the proportion of acid anhydride containing a benzene ring and acid anhydride not containing a benzene ring, can reduce the viscosity of hyperbranched polyol while improving the strength, realizes the synergistic adjustment of the viscosity and rigidity of the hyperbranched polyester amide polyol, and meets the balanced demand of the mechanical properties and process properties of subsequent rigid polyurethane foam.

[0091] Meanwhile, by introducing polyethylene glycol at one end of the hyperbranched structure, the viscosity of the polyester amide polyol is further reduced, and the compatibility of the polyester amide polyol with commercial polyols is also improved.

[0092] 2) Environmental protection breakthrough

[0093] The ozone layer depletion potential of water is zero, completely avoiding the damage to the ozone layer and the greenhouse effect problem of traditional fluorochlorocarbon blowing agents, and the preparation process is green and environmentally friendly, meeting the sustainable development demand;

[0094] The hyperbranched structure makes the polyol maintain low viscosity at high molecular weight, reduces the viscosity of the combined material, meets the flowability requirement of the foaming process, does not need additional solvent adjustment, and the hyperbranched polyester amide polyol is in a flowing state, can be miscible with other components of the combined material under the condition of no solvent, and reacts with isocyanate, avoiding the use of organic solvents and reducing pollution.

[0095] 3) Cost and process advantages

[0096] The preparation process of the hyperbranched polyol provided by the application synthesizes the hyperbranched polyol by using a simple one-pot melt polymerization method, does not need to add raw materials in batches, does not need to grind the product into a powder after synthesis is completed, saves post-treatment time, and the preparation process is simple; meanwhile, the raw materials are widely sourced and low in cost, and have certain advantages in time consumption and cost, and are easy to mass-produce industrially.

[0097] 4) The role of chemical blowing agent

[0098] When all water is used as a blowing agent, the following problems exist in the physical properties of the foam:

[0099] ① The foam is brittle and low in strength. When the required foam density is low, a large amount of water needs to react with isocyanate to generate enough CO2, so that the foam body becomes brittle due to excessive generation of urea groups, the toughness of the foam decreases, and the foam is easy to powder and fall off. At the same time, low-density foam (such as <30 kg / m 3 ) is particularly obvious, which is manifested as insufficient compressive strength and low elongation at break;

[0100] ② Poor dimensional stability. Since the overflow speed of CO2 is 10 times faster than the infiltration speed of air, a negative pressure is easily formed in the foam, which leads to shrinkage and deformation of the foam (especially low-density foam in low-temperature or high-humidity environment).

[0101] ③ Closed cell rate is usually only 90%~92% (ideal value needs >95%), which affects waterproofness and long-term stability.

[0102] There are the following problems in process performance:

[0103] ① High viscosity and poor flowability of the system. Due to lack of dilution effect of physical foaming agent, the viscosity of the combined polyether is large, which leads to uneven mixing, large cell, and incomplete filling (especially for complex molds);

[0104] ② Severe reaction heat release. Without water participating in the endothermic process (such as physical foaming agent vaporization can absorb heat), the accumulated reaction heat is easy to cause burning core and cracking.

[0105] Therefore, by using water to partially replace the physical foaming agent, the urea group can be generated in the molecular chain, the strength and rigidity of the foam body are improved, and the mechanical properties of the polyurethane foam are improved. At the same time, the above problems are avoided, and it is more green and environmentally friendly, simple to operate, and low in cost.

[0106] 5) Role of hyperbranched polyester amide polyol

[0107] The hyperbranched polyester amide polyol has a three-dimensional spatial topological structure and a large number of active functional groups, which can give the material excellent strength and special functionality. Its special branched structure makes it have low viscosity, a large number of end group functional groups, a large free volume, non-crystallinity, high solubility and other characteristics.

[0108] The hyperbranched structure significantly increases the crosslinking density of the polyurethane foam by a large number of end group functional groups on the polyol, which simultaneously improves the compression strength, wear resistance and temperature resistance; the free volume introduced by the hyperbranched structure improves the toughness and impact resistance of the material, solving the contradiction that high-strength materials are easy to be brittle; a large number of amide bonds exist in the hyperbranched polyester amide polyol, which can further improve the structural rigidity of the foam material as hard segments, and the existence of amide bonds provides more intermolecular hydrogen bonds, further improving the temperature resistance of the polyurethane foam. BRIEF DESCRIPTION OF DRAWINGS

[0109] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the following drawings:

[0110] Figure 1 The compression strength comparison chart of the rigid polyurethane foam prepared by the hyperbranched polyester amide polyol of Example 1 of the present application 1 H NMR spectrum

[0111] Figure 2 The compression strength comparison chart of the rigid polyurethane foam prepared by the hyperbranched polyester amide polyol of Example 1 of the present application

[0112] Figure 3 Comparison chart of compressive strength of rigid polyurethane foams prepared for Inventive Example 8, Inventive Example 11, Inventive Example 12, and Comparative Example 3;

[0113] Figure 4 Comparison chart of compressive strength of rigid polyurethane foams prepared for Inventive Example 8, Inventive Example 13, Inventive Example 14, Inventive Example 15, and Inventive Example 18;

[0114] Figure 5 Comparison chart of compressive strength of rigid polyurethane foams prepared for Inventive Example 8, Inventive Example 16, and Inventive Example 17. DETAILED DESCRIPTION

[0115] The application will be described in detail below with reference to the embodiments. The following embodiments will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be noted that those skilled in the art can make several adjustments and improvements without departing from the concept of the application. These are within the scope of protection of the application.

[0116] For the convenience of understanding, first, the abbreviations or nouns mentioned in the following are explained:

[0117] PC-5: pentamethyldiethylenetriamine;

[0118] T-12: dibutyltin dilaurate;

[0119] HCFC-141b: one fluorine dichloroethane;

[0120] TCPP: tris (2-chloropropyl) phosphate.

[0121] The specific embodiment provides a hyperbranched polyester amide polyol, which is a random copolymer, and the structural general formula is:

[0122]

[0123] wherein each R is independently selected from R1or R2, , ;

[0124] wherein x = 1-10, y = 1-10, z = 1-20, m = 1-10, n = 1-10.

[0125] It should be noted that in the structural general formula, the starting position of the repeat functional groups corresponding to n, x, and y is consistent with the starting position of the repeat functional groups corresponding to m, that is, the repeat functional groups corresponding to m, n, x, and y share the starting position.

[0126] Next, the preparation method of the hyperbranched polyester amide polyol is introduced, and the steps are as follows:

[0127] Under the protection of nitrogen, the aliphatic alcohol amine monomer, acid anhydride and monomethyl ether polyethylene glycol are loaded into a three-necked round-bottom flask with a condensate water receiving device, stirred at a first temperature for a first time; then the reaction temperature is increased to a second temperature, and the stirring is continued for a second time, then the flask is cooled to room temperature, and the hyperbranched polyester amide polyol is obtained.

[0128] Next, the preparation method of the hyperbranched polyester amide polyol is introduced, and the steps are as follows:

[0129] Example 1

[0130] Table 1

[0131]

[0132] The hyperbranched polyester amide polyol prepared in this example has a functionality of 8.3 ~ 9.2, a hydroxyl value of 340 ~ 380 mgKOH·g -1 , a viscosity of 700 ~ 800 mPa·s, a molecular weight of 1342 g / mol, a branching degree of 0.54, and a water content of 0.5%. It has the characteristics of high hydroxyl value, high functionality and low viscosity. The low viscosity is due to the introduction of monomethyl ether polyethylene glycol (PEG) in this example, which reduces the hydrogen bonding between hyperbranched polyester amide polyols.

[0133] Figure 1 The hyperbranched polyester amide polyol prepared in this example has a functionality of 8.3 ~ 9.2, a hydroxyl value of 340 ~ 380 mgKOH·g 1 H NMR spectrum, in which the resonance peaks at 3.65-3.54, 4.40-4.24, 4.11-4.02 and 4.85-4.54 ppm are assigned to the terminal, linear and branched methylene protons of the hyperbranched polymer, confirming its hyperbranched structure.

[0134] In the hyperbranched polyester amide polyol prepared in this example, the number ratio of R1 and R2 is 4:1.

[0135] Example 2

[0136] Table 2

[0137]

[0138] The hyperbranched polyester amide polyol prepared in this example has a functionality of 8.0 ~ 9.0, a hydroxyl value of 320 ~ 360 mgKOH·g -1, viscosity 800~900 mPa·s, molecular weight 1470 g / mol, branching degree 0.53, moisture content 0.4%, with the characteristics of high hydroxyl value, high functionality, low viscosity. But compared with Example 1, the viscosity rises to a certain extent.

[0139] In the hyperbranched polyester amide polyols prepared in this example, the number ratio of R1 and R2 is 1:1.

[0140] Example 3

[0141] Table 3

[0142]

[0143] The hyperbranched polyester amide polyols prepared in this example have a functionality of 8.3~9.0, a hydroxyl value of 335~375 mgKOH·g -1 , viscosity 600~700 mPa·s, molecular weight 1158 g / mol, branching degree 0.52, moisture content 0.6%, with the characteristics of high hydroxyl value, high functionality, low viscosity. Compared with Example 1, the viscosity further decreases.

[0144] In the hyperbranched polyester amide polyols prepared in this example, R is R1.

[0145] Example 4

[0146] Table 4

[0147]

[0148] The hyperbranched polyester amide polyols prepared in this example have a functionality of 7.9~8.7, a hydroxyl value of 340~400 mgKOH·g -1 , viscosity 900~1000 mPa·s, molecular weight 1500 g / mol, branching degree 0.53, moisture content 0.5%, with the characteristics of high hydroxyl value, high functionality, low viscosity. But compared with Example 2, the viscosity further rises.

[0149] In the hyperbranched polyester amide polyols prepared in this example, R is R2.

[0150] Example 5

[0151] Table 5

[0152]

[0153] The hyperbranched polyester amide polyols prepared in this example have a functionality of 9.5~10.4, a hydroxyl value of 360~400 mgKOH·g -1, viscosity 1000~1200 mPa·s, molecular weight 2200 g / mol, branching degree 0.54, moisture content 0.6%, with the characteristics of high hydroxyl value, high functionality, low viscosity. But compared with Example 1, the second time is extended, the polymerization reaction time is extended, the molecular weight is significantly increased, and the viscosity is increased.

[0154] In the hyperbranched polyester amide polyols prepared in this example, the number ratio of R1 and R2 is 4:1.

[0155] Example 6

[0156] Table 6

[0157]

[0158] The difference between this example and Example 1 is only that the second temperature is increased to 240℃ and the second time is reduced to the lower limit of 1h. The functionality of the hyperbranched polyester amide polyols prepared is 8.3~9.2, the hydroxyl value is 340~380 mgKOH·g -1 , the viscosity is 700~800 mPa·s, the molecular weight is 1340 g / mol, the branching degree is 0.54, the moisture content is 0.5%, with the characteristics of high hydroxyl value, high functionality, low viscosity. Basically the same as Example 1, the reason is that appropriate increase of the second temperature can accelerate the reaction process of the second stage, and achieve the same polymerization effect in a shorter time.

[0159] In the hyperbranched polyester amide polyols prepared in this example, the number ratio of R1 and R2 is 4:1.

[0160] Example 7

[0161] Table 7

[0162]

[0163] The functionality of the hyperbranched polyester amide polyols prepared in this example is 8.2~9.1, the hydroxyl value is 330~360 mgKOH·g -1 , the molecular weight is 1200 g / mol, the branching degree is 0.54, the moisture content is 0.6%, with the characteristics of high hydroxyl value, high functionality. The hyperbranched polyester amide polyols synthesized in this example do not contain polyethylene glycol groups, resulting in a solid product that is difficult to achieve mutual compatibility with commercial polyols and cannot be foamed.

[0164] Next, the method for preparing rigid polyurethane foam using the hyperbranched polyester amide polyols prepared above is introduced, the steps are as follows:

[0165] Mixing and first stirring A component (hyperbranched polyester amide polyol, high functionality polyether polyol, catalyst, foam stabilizer, crosslinking agent, physical foaming agent, chemical foaming agent, flame retardant) to uniform state, to obtain polyol combination material;

[0166] Quickly add B component (polyisocyanate) to the polyol combination material, and secondly stir at room temperature to obtain PU slurry;

[0167] Quickly inject the PU slurry into the previously preheated mold for foaming, and then put it into the oven together with the mold for processing, and cool to room temperature.

[0168] Open the mold, peel off and take out the white product to obtain the hard polyurethane foam containing hyperbranched structure.

[0169] The preparation method of the hard polyurethane foam containing hyperbranched structure is specifically introduced by examples 8 to 18.

[0170] Example 8

[0171] This example provides a preparation method of hard polyurethane foam using the hyperbranched polyester amide polyol prepared in example 1, specifically:

[0172] The high functionality polyether polyol in this example has a functionality of 4.6~5.8, a hydroxyl value of 360~400 mg KOH•g -1 , and a viscosity of 10000~12500 mPa·s; the polyisocyanate has an-NCO content of 30~35%, a functionality of 2.5~2.9, a viscosity of 150~250 mPa·s, and a density of 1.20~1.30 g / cm 3 .

[0173] The polyether polyol used in this example is purchased from Langfang Huayu Innovation Technology Co., Ltd., and the brand is 380.

[0174] The A component is as follows in terms of mass fraction:

[0175] Hyperbranched polyester amide polyol: 70 parts;

[0176] High functionality polyether polyol: 30 parts;

[0177] Catalyst: PC-5, 1.8 parts;

[0178] Catalyst: T-12, 0.6 parts;

[0179] Foam stabilizer: M-88308, 1.5 parts;

[0180] Crosslinking agent: polyether 403, 10 parts;

[0181] Physical blowing agent: HCFC-141b, 5 parts;

[0182] Chemical blowing agent: deionized water, 1.8 parts;

[0183] Flame retardant: TCPP, 10 parts.

[0184] The B component is: a polyisocyanate, the mass fraction of which is the total mass fraction of the A component.

[0185] The first stirring parameter is 1000 r / min, and the stirring time is 30 min; the second stirring parameter is 1000 r / min, and the stirring time is 15 s.

[0186] The mold is preheated to 60°C, the PU slurry is poured into the mold, foamed for 1 h, and then moved into a 60°C oven for 24 h.

[0187] The viscosity of the polyol combination material obtained in this example is 900-1000 mPa·s, which can meet the foaming process requirements (the viscosity requirement of a general polyurethane foaming machine for a combined polyether is ≯1500 mPa·s).

[0188] The rigid polyurethane foam containing a hyperbranched structure prepared in this example has a density of 52 kg / m 3 , a thermal conductivity of 0.019 W / (m·K), a compressive strength of 0.82 MPa, and a dimensional change rate of 0.22%. The rigid polyurethane foam containing a hyperbranched structure prepared in this example has a light weight, a strong load-bearing capacity, a good thermal insulation performance, and excellent dimensional stability.

[0189] Example 9

[0190] This example provides a method for preparing a rigid polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 1, and the steps are basically the same as those of Example 8, except that:

[0191] In the A component, the hyperbranched polyester amide polyol is 80 parts, and the high-functionality polyether polyol is 20 parts.

[0192] The viscosity of the polyol combination material obtained in this example is 800-900 mPa·s, which can meet the foaming process requirements.

[0193] The rigid polyurethane foam containing a hyperbranched structure prepared in this example has a density of 53 kg / m 3, the thermal conductivity is 0.025 W / (m·K), the compressive strength is 0.50 MPa, the dimensional change rate is 0.29%, the foaming is insufficient, irregular, uneven and not dense.

[0194] Example 10

[0195] This example provides a preparation method of hard polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 1, and the steps are basically the same as those of Example 8, and the difference is that:

[0196] In the A component, the hyperbranched polyester amide polyol is 20 parts, and the high-functionality polyether polyol is 80 parts.

[0197] The polyol combination material obtained in this example has a viscosity of 4000-6000 mPa·s, which cannot meet the foaming process requirements.

[0198] The hard polyurethane foam containing hyperbranched structure prepared in this example has a density of 55 kg / m 3 , the thermal conductivity is 0.025 W / (m·K), the compressive strength is 0.50 MPa, the dimensional change rate is 0.29%, the foaming is insufficient, irregular, uneven and not dense.

[0199] Compared with Example 8, the strength of the hard polyurethane foam prepared in this example is significantly reduced, which is due to the reduction of the content of the hyperbranched polyester amide polyol. On the one hand, the viscosity of the polymer increases, affecting the uniform expansion of the bubbles in the foaming process. The uneven bubble structure (such as different pore diameters and weak pore walls) will weaken the supporting capacity of the foam, resulting in a decrease in the compressive strength. On the other hand, the crosslinking density is reduced, and the foam structure strength is low.

[0200] Example 11

[0201] This example provides a preparation method of hard polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 1, and the steps are basically the same as those of Example 8, and the difference is that:

[0202] In the A component, the physical foaming agent is 7.78 parts, and the chemical foaming agent is 1.56 parts.

[0203] The polyol combination material obtained in this example has a viscosity of 800-900 mPa·s, which can meet the foaming process requirements.

[0204] The hard polyurethane foam containing hyperbranched structure prepared in this example has a density of 53 kg / m 3, the thermal conductivity is 0.018 W / (m·K), the compression strength is 0.81 MPa, the dimensional change rate is 0.21%, the cells are regular, uniform and dense.

[0205] Compared with Example 8, the content of chemical foaming agent water is slightly reduced, the viscosity of combined polyether is slightly reduced, the generation of urea groups by reaction with isocyanate is slightly reduced, the compression strength is slightly reduced, and the dimensional stability is slightly improved.

[0206] Example 12

[0207] This example provides a method for preparing a rigid polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 1, the steps of which are basically the same as those of Example 8, except that:

[0208] In the A component, the physical foaming agent is 3.23 parts; the chemical foaming agent is 2.15 parts.

[0209] The viscosity of the polyol combination material obtained in this example is 1100-1200 mPa·s, which can meet the processability requirements of foaming.

[0210] The rigid polyurethane foam prepared in this example containing hyperbranched structure has a density of 52 kg / m 3 , the thermal conductivity is 0.020 W / (m·K), the compression strength is 0.83 MPa, the dimensional change rate is 0.24%, and the cells are regular, uniform and dense.

[0211] Compared with Example 8, the content of chemical foaming agent water is increased, the viscosity of combined polyether is increased, the generation of urea groups by reaction with isocyanate is increased, the compression strength is increased, and the dimensional stability is slightly reduced.

[0212] Example 13

[0213] This example provides a method for preparing a rigid polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 2, the steps of which are basically the same as those of Example 8, except that:

[0214] The viscosity of the polyol combination material obtained in this example is 1000-1100 mPa·s, which can meet the processability requirements of foaming.

[0215] The rigid polyurethane foam prepared in this example containing hyperbranched structure has a density of 55 kg / m 3 , the thermal conductivity is 0.020 W / (m·K), the compression strength is 0.84 MPa, the dimensional change rate is 0.21%, and the cells are regular, uniform and dense. The rigid polyurethane foam containing hyperbranched structure prepared in this example is light in weight, strong in load-bearing capacity, good in thermal insulation performance and excellent in dimensional stability.

[0216] Compared with Example 8, the benzene ring content in the hyperbranched polyester amide polyol synthesized in this example is increased, and thus the compressive strength is increased.

[0217] Example 14

[0218] This example provides a method for preparing rigid polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 3. The steps are basically the same as those in Example 8, except that:

[0219] The viscosity of the polyol composition obtained in this example is 800-900 mPa·s, which can meet the foaming process requirements.

[0220] The rigid polyurethane foam containing hyperbranched structure prepared in this example has a density of 57 kg / m 3 The thermal conductivity was 0.021 W / (m·K), the compressive strength was 0.75 MPa, the dimensional change rate was 0.25%, and the cells were regular, uniform, and dense. This demonstrates that the rigid polyurethane foam containing a hyperbranched structure prepared in this example is lightweight, has a strong load-bearing capacity, good thermal insulation properties, and excellent dimensional stability.

[0221] Compared with Example 8, the hyperbranched polyester amide polyol synthesized in this example does not contain a benzene ring, resulting in a relatively low compressive strength.

[0222] Example 15

[0223] This example provides a method for preparing rigid polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 4. The steps are basically the same as those in Example 8, except that:

[0224] The viscosity of the polyol composition obtained in this embodiment is 1100-1200 mPa·s, which can meet the foaming process requirements.

[0225] The rigid polyurethane foam containing hyperbranched structure prepared in this example has a density of 56 kg / m 3 The thermal conductivity was 0.022 W / (m·K), the compressive strength was 0.86 MPa, the dimensional change rate was 0.20%, and the cells were regular, uniform, and dense. This demonstrates that the rigid polyurethane foam containing a hyperbranched structure prepared in this example is lightweight, has a strong load-bearing capacity, good thermal insulation properties, and excellent dimensional stability.

[0226] Compared with Example 8, the hyperbranched polyester amide polyol synthesized in this embodiment contains only anhydrides with benzene rings. The benzene rings increase chain rigidity and reduce segment motion. At the same time, physical cross-linking points may be formed due to π-π stacking, thereby increasing viscosity and increasing strength due to rigid groups.

[0227] Example 16

[0228] The present example provides a method for preparing rigid polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 5, the steps of which are substantially the same as those of Example 8, except that:

[0229] The polyol compound obtained in the present example has a viscosity of 2400-2500 mPa-s, which cannot meet the process requirements of the foaming equipment.

[0230] The rigid polyurethane foam prepared in the present example has a density of 55 kg / m 3 , a thermal conductivity of 0.029 W / (m-K), a compressive strength of 0.63 MPa, and a dimensional change rate of 0.30%. The foaming is not sufficient, and the cells are irregular, non-uniform, and non-dense.

[0231] However, compared with Example 8, the molecular weight of the hyperbranched polyester amide polyol synthesized in the present example is significantly increased, and the viscosity is increased, which affects the uniform expansion of the bubbles during the foaming process. The non-uniform bubble structure (such as different pore diameters and weak pore walls) can weaken the supporting capacity of the foam, resulting in a decrease in the compressive strength, which cannot meet the process requirements of the foaming process well.

[0232] Example 17

[0233] The present example provides a method for preparing rigid polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 6, the steps of which are substantially the same as those of Example 8, and the foam performance is also substantially the same as that of Example 8. The density is 51 kg / m 3 , the thermal conductivity is 0.018 W / (m-K), the compressive strength is 0.83 MPa, and the dimensional change rate is 0.21%. The cells are regular, uniform, and dense. It is shown that the rigid polyurethane foam containing hyperbranched structure prepared in the present example is light in weight, strong in bearing capacity, good in thermal insulation performance, and excellent in dimensional stability.

[0234] Example 18

[0235] The present example provides a method for preparing rigid polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 7, the steps of which are substantially the same as those of Example 8, except that:

[0236] The polyol compound obtained in the present example has a viscosity of 2400-2500 mPa-s, which cannot meet the process requirements of the foaming equipment.

[0237] The rigid polyurethane foam containing hyperbranched structure prepared in the embodiment has a density of 56 kg / m 3 , a thermal conductivity of 0.025 W / (m·K), a compressive strength of 0.48 MPa, and a dimensional change rate of 0.28%. The foam has irregular, uneven and non-dense cells. Compared with Example 8, the rigid polyurethane foam containing hyperbranched structure prepared in the embodiment has weaker load-bearing capacity, poorer thermal insulation performance and poorer dimensional stability.

[0238] Comparative Example 1

[0239] The embodiment provides a preparation method of rigid polyurethane foam without hyperbranched polyester amide polyol, and the steps are basically the same as those of Example 8, and the difference lies in that:

[0240] The high-functionality polyether polyol in the A component is 100 parts, and the hyperbranched polyester amide polyol is not contained.

[0241] In the embodiment, the viscosity of the polyol combination is 5000-8000 mPa·s, and the rigid polyurethane foam prepared has a density of 50 kg / m 3 , a thermal conductivity of 0.024 W / (m·K), a compressive strength of 0.45 MPa, and a dimensional change rate of 0.30%. The foam is not fully foamed, irregular, uneven and non-dense.

[0242] Compared with Example 8, the strength of the rigid polyurethane foam prepared in the embodiment is significantly reduced, because the hyperbranched polyester amide polyol is not contained. On the one hand, the viscosity of the polymer is increased, which affects the uniform expansion of the bubbles in the foaming process. The uneven bubble structure (such as different pore diameters and weak pore walls) will weaken the supporting capacity of the foam, resulting in a decrease in the compressive strength. On the other hand, the crosslinking density is low, and the foam structure strength is low.

[0243] Comparative Example 2

[0244] The embodiment provides a preparation method of rigid polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 1, and the steps are basically the same as those of Example 8, and the difference lies in that:

[0245] The hyperbranched polyester amide polyol in the A component is 30 parts, and the high-functionality polyether polyol is 70 parts.

[0246] In the embodiment, the viscosity of the polyol combination is 3000-5000 mPa·s, which cannot meet the process requirements of the foaming equipment.

[0247] The rigid polyurethane foam containing hyperbranched structure prepared in the embodiment has a density of 53 kg / m 3The thermal conductivity is 0.023 W / (m·K), the compressive strength is 0.54 MPa, the dimensional change rate is 0.28%, the foaming is insufficient, irregular, uneven, and not dense.

[0248] Compared with Example 8, the strength of the rigid polyurethane foam prepared in this example is significantly reduced. The reason is that the content of hyperbranched polyester amide polyol is reduced, which on the one hand leads to an increase in the viscosity of the polymer, affecting the uniform expansion of bubbles during the foaming process. The uneven bubble structure (such as different pore sizes and weak pore walls) will weaken the supporting capacity of the foam, resulting in a decrease in compressive strength; on the other hand, the cross-linking density is reduced and the foam structure strength is low.

[0249] Comparative Example 3

[0250] This example provides a method for preparing rigid polyurethane foam using the hyperbranched polyester amide polyol prepared in Example 1. The steps are basically the same as those in Example 8, except that:

[0251] In component A, the physical foaming agent: HCFC-141b is 14 parts, and the chemical foaming agent deionized water is not contained.

[0252] In this embodiment, the viscosity of the polyol composition is 700-800 mPa·s, which can meet the foaming process requirements.

[0253] The rigid polyurethane foam containing hyperbranched structure prepared in this example has a density of 45 kg / m 3 , thermal conductivity is 0.020 W / (m·K), compressive strength is 0.70 MPa, dimensional change rate is 0.20%, and the pores are regular, uniform and dense.

[0254] Compared with Example 8, in this example, except for a small amount of water in the synthesized hyperbranched polyester amide polyol, no additional water reacts with isocyanate to form urea groups. At the same time, the HCFC-141b volatilized during the foaming process requires corresponding tail gas treatment to avoid environmental pollution.

[0255] Performance testing methods

[0256] The rigid polyurethane foam prepared in the present invention was tested using the following method:

[0257] Apparent core density: The density of the foam was measured according to GB / T 6343-2009. The size was 100 mm × 100 mm × 50 mm. Five samples were grouped together and the average value was taken.

[0258] Compression performance test: cut the foam plastic into 100 mm x 100 mm x 50 mm size sample, according to GB / T 8813-2008, compression performance test was carried out on the electronic universal testing machine. The compression rate was 5 mm / min. Five samples were a group, and the data was averaged. Figures 2 to 5 The compression strength comparison chart of the samples prepared for each embodiment and the comparative example.

[0259] Dimensional stability test: according to GB / T 8811-2008, the dimensional stability of the foam was tested, the size specification was 100 mm x 100 mm x 25 mm, three samples were a group, and the data was averaged.

[0260] Thermal conductivity test: according to GB / T 3399-1982, the thermal conductivity of the foam was tested, the size specification was 40 mm x 40 mm x 5 mm, two samples were a group, and the data was averaged.

[0261] In summary, by molecular structure design, the high hydroxyl value, high functionality and low viscosity polyester amide hyperbranched polyol is synthesized by simple one-pot melt polymerization method, and it is introduced into the polyurethane foam material, which effectively improves the compression strength of the polyurethane foam material, so that the polyurethane foam has the function of bearing / heat insulation integration, improves the comprehensive performance of the material, at the same time meets the demand of foaming equipment, can be applied to the heat insulation scene with high bearing working condition. The synthesis method has wide raw material sources and low cost, has certain advantages in time and cost, and is easy to realize large-scale industrialized preparation.

[0262] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the above specific embodiments, and those skilled in the art can make various modifications or modifications within the scope of the claims, which does not affect the essential content of the present application.

Claims

1. A method for preparing rigid polyurethane foam, characterized in that, The following steps are involved: Mixing component A and stirring for the first time until the mixture is uniform to obtain a polyol composition; adding polyisocyanate to the polyol composition, and stirring for a second time at the third temperature to obtain a PU slurry; injecting the PU slurry into a preheated mold for foaming, then treating the PU slurry together with the mold at a fourth temperature and cooling to room temperature to obtain the rigid polyurethane foam; The component A comprises, by mass, 70-120 parts of hyperbranched polyester amide polyol, 20-55 parts of polyether polyol, 0.6-5.0 parts of catalyst, 1-3 parts of foam stabilizer, 5-15 parts of cross-linking agent, 0.5-20 parts of physical foaming agent, 0.5-20 parts of chemical foaming agent, and 5-15 parts of flame retardant; The polyisocyanate is 100 to 150 parts; The chemical foaming agent is water; The physical foaming agent is one or more of HFC-245fa, HFC-134a, HFC-365mfc, HFC-227ea, HCFC-141b, CFC-11, cyclopentane, n-pentane, cycloisopentane, and 3,3-trifluoropropylene; The mass ratio of the polyisocyanate to the polyol combination is 1-1.2:1; The mass ratio of the hyperbranched polyester amide polyol to the polyether polyol is 7-12:3; The mass ratio of the physical foaming agent to the chemical foaming agent is 1.5-5:1; The functionality of the hyperbranched polyester amide polyol is 7.9-9.2, and the hydroxyl value is 320-400 mgKOH·g -1 , viscosity 600~1000 mPa·s, molecular weight 1158~1500 g / mol, degree of branching 0.52~0.54, moisture content ≤0.6%; The preparation method of the hyperbranched polyester amide polyol comprises the following steps: Under a protective atmosphere, aliphatic alcohol amine monomer, acid anhydride and monomethyl ether polyethylene glycol in a molar ratio of 1:1:0.1-0.125 are reacted by stirring at 90-120°C for 0.5-4 hours by heating under reflux, then the reaction is continued with stirring at a reaction temperature of 120-240°C for 1-4 hours, and the reaction is cooled to room temperature to obtain the hyperbranched polyester amide polyol, wherein the acid anhydride is a phenyl ring-containing acid anhydride and / or a phenyl ring-free acid anhydride; The aliphatic alcohol amine monomer is: 3-amino-1,2-propylene glycol; The anhydride containing phenyl ring is: 1,2,4-benzenetricarboxylic anhydride; The anhydride containing no phenyl ring is: succinic anhydride; The functionality of the polyether polyol is 4.6-5.8, and the hydroxyl value is 360-400 mgKOH·g -1 , viscosity is 10000~12500mPa·s; The polyisocyanate has an -NCO content of 30% to 35%, a functionality of 2.5 to 2.9, a viscosity of 150 to 250 mPa•s, and a density of 1.20 to 1.30 g•cm -3 .

2. The method according to claim 1, characterized in that Also includes at least one of the following technical features: A2, the molar fraction of the acid anhydride with a benzene ring in the acid anhydride is 20% to 100%; B2, the molar fraction of the acid anhydride without a benzene ring in the acid anhydride is 50% to 100%; C2, the molar ratio of the acid anhydride with a benzene ring to the acid anhydride without a benzene ring in the acid anhydride is 1: 1~4.

3. The method according to claim 1, characterized in that It also includes one or more of the following technical features: A4. The catalyst is one or more of tetramethylethylenediamine, triethanolamine, triethylenediamine, N,N-dimethylcyclohexylamine, 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine, pentamethyldiethylenetriamine, triethylenediamine, A-33, PT303, stannous octoate, dibutyltin dilaurate, dibutyltin mercaptan, dibutyltin diacetate, MB20, and butyl titanate; B4. The foam stabilizer is one or more of M-8805, M-8808, M-8809, M-8815, M-8860, M-88308, M-88310, M-88108, M-88109, M-88716, and M-88719; C4, the cross-linking agent is one or more of glycerol, pentaerythritol, sorbitol, sucrose, and polyether 403; E4. The flame retardant is one or more of TCPP, TCEP and TEP.

4. The method according to claim 1, wherein It also includes one or more of the following technical features: A5, the stirring speed of the first stirring is 800~2000 r / min, and the stirring time is 20~50 min; B5, the stirring speed of the second stirring is 800~2000 r / min, and the stirring time is 10~30 s; C5, the third temperature is 25-35°C; D5. The mold preheating temperature is 40~90℃; E5. The fourth temperature is 60-120° C., and the treatment time is 12-48 h.

5. A rigid polyurethane foam, characterized in that It is prepared according to the method according to any one of claims 1 to 4.

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