Flame-retardant polyurethane foam containing halogen-free phosphorus flame retardant and preparation method of flame-retardant polyurethane foam

Abstract

The invention discloses flame-retardant polyurethane foam containing a halogen-free phosphorus flame retardant and a preparation method of the flame-retardant polyurethane foam. The flame-retardant polyurethane foam comprises the following components in percentage by weight: 60-150 parts of isocyanate, 100 parts of polyol, 10-30 parts of a phosphorus flame retardant composition and 5-38 parts of an auxiliary agent, and the density of the flame-retardant polyurethane foam is 10-120kg / m < 3 >; the phosphorus flame retardant composition comprises a phosphaphenanthrene flame retardant and a phosphate flame retardant, the phosphaphenanthrene flame retardant is a derivative of 9, 10-dihydro-9-oxa-10-phosphaphenanthrene oxide, and the phosphate flame retardant is poly-type phosphate; according to the invention, the phosphaphenanthrene derivative flame retardant with the active group hydroxyl and the polyphosphate type flame retardant are compounded and then used for flame retardant polyurethane foam, and the obtained polyurethane foam has the advantages of good flame retardant property, high oxygen index, good flame retardant property, good stability, excellent mechanical properties and good dimensional stability, and the flame retardant is not easy to migrate out.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flame-retardant polyurethane foam, in particular to a flame-retardant polyurethane foam containing halogen-free phosphorus flame retardant and a preparation method thereof. BACKGROUND

[0002] Polyurethane foam is a kind of polymer material with excellent performance, which has low thermal conductivity, excellent thermal insulation performance, high mechanical strength, strong adhesion and is easy to process. It is widely used in transportation, building, oil pipeline, civil household and other fields. However, the flame retardant performance of polyurethane foam is poor, and its oxygen index (LOI) is only between 16-18%, which is highly flammable, limiting its application. Therefore, more and more attention has been paid to the flame retardant of polyurethane foam, especially halogen-free flame retardant.

[0003] Disadvantages of the prior art: Currently, the method of adding flame retardant can be used to improve the flame retardant performance of polyurethane foam. The flame retardant used for polyurethane foam is mostly phosphate, such as tris (1-chloro-2-propyl) phosphate (TCPP), triethyl phosphate (TEP) and the like. Such phosphates are mostly liquid, with high phosphorus content and high flame retardant efficiency. At the same time, the viscosity is low, and the operation is convenient. It has a wide range of uses in the construction, household, thermal insulation material and other industries. However, it is found in actual use that such phosphates are mostly liquid, which is easy to precipitate on the surface of polyurethane after long-term use, resulting in poor flame retardant performance and poor flame retardant stability of the prepared polyurethane. Moreover, most liquid flame retardants have strong plasticizing effect, which has an adverse effect on the mechanical properties of polyurethane board, such as compression resistance. Even long-term use will cause shrinkage deformation of polyurethane foam itself, which cannot be used in some fields with high requirements for mechanical properties and dimensional stability of polyurethane, such as automobile, new energy automobile battery cover plate, door plate and the like. At the same time, with the increasing attention to environmental protection, the traditional halogen-based flame retardant has been gradually banned, which is more obvious in the application of automobile and high-speed rail fields in relevant legal regulations. SUMMARY

[0004] The present application aims to provide a flame-retardant polyurethane foam containing halogen-free phosphorus flame retardant and a preparation method thereof, to solve the problems in the background art.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a flame-retardant polyurethane foam containing halogen-free phosphorus flame retardant, which comprises, by weight percentage, isocyanate 60-150 parts, polyol 100 parts, phosphorus flame retardant composition 10-30 parts and auxiliary agent 5-38 parts, and the density of the flame-retardant polyurethane foam is 10-120 kg / m 3 .

[0006] Preferably, the phosphorus-based flame retardant composition comprises a phosphaphenanthrene flame retardant and a phosphate ester flame retardant, the phosphaphenanthrene flame retardant is a derivative of 9,10-dihydro-9-oxa-10-phosphaphenanthrene oxide, the phosphate ester flame retardant is a polymeric phosphate ester, and the mass ratio of the derivative of 9,10-dihydro-9-oxa-10-phosphaphenanthrene oxide to the polymeric phosphate ester is 1:0.5-1:4.

[0007] Preferably, the phosphaphenanthrene flame retardant is selected as at least one of DOPO-MEOH and DOPO-TBD, the structure of the DOPO-MEOH is: ; The structure of the DOPO-TBD is: .

[0008] Preferably, the particle size D50 of the phosphaphenanthrene flame retardant is ≤5 μm.

[0009] Preferably, the structure of the polymeric phosphate ester is: .

[0010] Preferably, the phosphorus-based flame retardant composition further comprises water less than or equal to 0.3%.

[0011] Preferably, the isocyanate is selected as at least one of toluene diisocyanate and phenylmethane diisocyanate.

[0012] Preferably, the polyol is selected as a polyester polyol or a polyether polyol or a mixture of a polyester polyol and a polyether polyol, and the hydroxyl value of the polyol is 20-1000 mg KOH / g.

[0013] Preferably, the auxiliary agent is selected as a catalyst, a surfactant and a blowing agent, the catalyst is selected as an organic tin or an amine, the surfactant is selected as a siloxane-alkylene oxide copolymer or other organopolysiloxane, and the blowing agent is selected as at least one of water, cyclohexane or a fluorine-containing blowing agent.

[0014] The application further provides a preparation method of a halogen-free phosphorus-based flame-retardant polyurethane foam, and the preparation method specifically comprises: S1, adding a polyol, a hard foam silicone oil M88108, a catalyst, water and pentafluoropropane into a beaker and stirring for 15 s to prepare a mixed polyether; S2, adding a phosphaphenanthrene flame retardant and a phosphate ester flame retardant and stirring at a high speed for 20-30 s; S3, adding a polymeric MDI and stirring for 10 s to form a mixture; S4, pouring the mixture into a mold for foaming; S5, the mixture is placed into an oven for curing, the curing temperature is 70 DEG C, and the time is set to 5h, to obtain the halogen-free flame-retardant polyurethane foam.

[0015] Compared with the prior art, the application has the following advantages: 1. The flame-retardant polyurethane foam containing halogen-free phosphorus flame retardant and the preparation method thereof, the phosphorus hetero derivative flame retardant with active groups of hydroxyl is compounded with the polyphosphate flame retardant, and then used for the flame-retardant polyurethane foam, so that the obtained polyurethane foam has good flame-retardant performance, high oxygen index, good flame-retardant performance, good stability, and the flame retardant is not easy to migrate out, and has excellent mechanical properties and good dimensional stability.

[0016] 2. The flame-retardant polyurethane foam containing halogen-free phosphorus flame retardant and the preparation method thereof, the foaming condition is mild, the process is simple, and the method is suitable for large-scale preparation and popularization and use in various occasions. DETAILED DESCRIPTION

[0019] Example 1 The technical scheme of the flame-retardant polyurethane foam containing halogen-free phosphorus flame retardant provided by the application is as follows: the flame-retardant polyurethane foam comprises, according to the weight percentage, 60-150 parts of isocyanate, 100 parts of polyol, 10-30 parts of phosphorus flame retardant composition and 5-38 parts of auxiliary agent, and the density of the flame-retardant polyurethane foam is 10-120 kg / m 3 The isocyanate is a polyurethane black material, the polyol, the phosphorus flame retardant composition and the auxiliary agent are polyurethane white materials, and the isocyanate, the polyol, the phosphorus flame retardant composition and the auxiliary agent are reacted to obtain polyurethane; the phosphorus flame retardant composition comprises phosphorus hetero derivative flame retardant and phosphate flame retardant, the phosphorus hetero derivative flame retardant is a derivative of 9,10-dihydro-9-oxa-10-phosphaphenanthrene oxide, the phosphate flame retardant is a polymeric phosphate, the mass ratio of the derivative of 9,10-dihydro-9-oxa-10-phosphaphenanthrene oxide to the polymeric phosphate is 1:0.5-1:4, and the phosphorus flame retardant composition further comprises less than or equal to 0.3% of water, so as to avoid that too much water causes the polyurethane foaming process to be abnormal. The particle size D50 of the phosphorus hetero derivative flame retardant is less than or equal to 5 microns, so as to ensure that the phosphorus hetero derivative flame retardant is well dispersed in the polyurethane.

[0020] The phosphorus hetero derivative flame retardant is selected to be at least one of DOPO-MEOH and DOPO-TBD, the flame retardant with DOPO as a skeleton structure not only has good flame-retardant effect, but also has high thermal stability and chemical stability, the two kinds of flame retardants contain active hydroxyl groups in the molecular structure, can be reacted with isocyanate to be connected to the polyurethane matrix molecules to form an intrinsic flame-retardant flame retardant, and the flame retardant in the flame-retardant rigid polyurethane foam is more stable and not easy to migrate and separate out; wherein the structure of DOPO-MEOH is: ; The structure of DOPO-TBD is as follows: .

[0021] The structure of the polymeric phosphate ester is as follows: .

[0022] The polymeric phosphate ester has a large molecular weight and is not easy to precipitate, and the phosphate ester group is connected to the polymer chain to form a polymer with a specific molecular weight and distribution, which has good hydrolysis stability, good thermal stability, good flame-retardant stability of the prepared polyurethane, and low content of volatile organic compounds.

[0023] The isocyanate is selected as at least one of toluene diisocyanate and phenylmethane diisocyanate.

[0024] The polyol is selected as a polyester polyol or a polyether polyol or a mixture of a polyester polyol and a polyether polyol, and the hydroxyl value of the polyol is 20-1000 mg KOH / g.

[0025] The auxiliary is selected as a catalyst, a surfactant and a foaming agent, the catalyst is selected as an organic tin or an amine, the organic tin is, for example, a tin(II) salt of an organic carboxylic acid, such as tin(II) acetate, stannous octoate, tin(II) laurate; and a dialkyl tin(IV) salt of an organic carboxylic acid, the amine contains, for example, N,N,N-triethylaminoethoxyethanol, dimethylcyclohexylamine, trimethylhydroxyethyl ethylenediamine, dimethylbenzylamine, triethylamine, triethylenediamine, pentamethyldipropylene triamine, dimethylethanolamine, tetramethylhexamethylenediamine, tris(dimethylaminopropyl)hexahydrotriazine, dimethylaminopropylamine; the surfactant is selected as a siloxane-alkylene oxide copolymer or other organopolysiloxane; and the foaming agent is selected as at least one of water, cyclohexane or fluorine-containing foaming agent.

[0026] The application also provides a preparation method of a flame-retardant polyurethane foam containing a halogen-free phosphorus-based flame retardant, and the preparation method specifically comprises the following steps: S1, 100 parts of polyol 6305, 1.6 parts of hard foam silicone oil M88108, 3.5 parts of catalyst PC-8, 1.5 parts of water, 25.0 parts of pentafluoropropane are added in a beaker and stirred for 15 s to prepare a mixed polyether; S2, 12 parts of phosphine flame retardant DOPO-MEOH and 13 parts of polyphosphate flame retardant are added and stirred at high speed for 30 s; S3, 113 parts of polymeric MDI are added and stirred for 10 s to form a mixture; S4, the mixture is poured into a mold and foamed; S5, the mixture is placed into an oven for curing, the curing temperature is 70 DEG C, and the time is set to 5h, to obtain a halogen-free flame-retardant polyurethane foam, denoted as M1.

[0027] Further, the properties of the halogen-free flame-retardant polyurethane foam prepared by the process are shown in Table 1, wherein the flame-retardant stability change is investigated by placing the polyurethane foam into a 70 DEG C oven for aging for 48 hours, placing at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance test is performed according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed into a 70 DEG C oven for storage for 48 hours, and storage at -20 DEG C for 48h, and the length size change rate of the sample piece of the polyurethane foam before and after aging is tested according to GB-T8811-2008, and the size change rate formula is: wherein L2 is the length of the sample piece after aging, and L1 is the length of the sample piece before aging.

[0028] Example 2 The application provides a preparation method of a flame-retardant polyurethane foam containing a halogen-free phosphorus-based flame retardant, and the preparation method specifically comprises the following steps: S1, 100 parts of polyol 6305, 1.8 parts of hard foam silicone oil M88108, 3.2 parts of catalyst PC-8, 1.8 parts of water, and 25.0 parts of pentafluoropropane are added into a beaker and stirred for 15s to prepare a mixed polyether; S2, 15 parts of a phosphine oxide flame retardant DOPO-TBD and 18 parts of a polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 118 parts of polymeric MDI are added and stirred for 15s to form a mixture; S4, the mixture is poured into a mold for foaming; S5, the mixture is placed into an oven for curing, the curing temperature is 70 DEG C, and the time is set to 5h, to obtain a halogen-free flame-retardant polyurethane foam, denoted as M2.

[0029] Further, the properties of the halogen-free flame-retardant polyurethane foam prepared by the process are shown in Table 1, wherein the flame-retardant stability change is investigated by placing the polyurethane foam into a 70 DEG C oven for aging for 48 hours, placing at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance test is performed according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed into a 70 DEG C oven for storage for 48 hours, and storage at -20 DEG C for 48h, and the length size change rate of the sample piece of the polyurethane foam before and after aging is tested according to GB-T8811-2008, and the size change rate formula is: Wherein, L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0030] Example 3 The present application provides a preparation method of a halogen-free phosphorus-based flame-retardant polyurethane foam, and the preparation method specifically comprises: S1, 100 parts of polyol 6305, 2.0 parts of hard foam silicone oil M88108, 3.2 parts of catalyst PC-8, 1.6 parts of water, 22.0 parts of pentafluoropropane are added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 5 parts of phosphine flame retardant DOPO-MeOH and 7 parts of polyphosphate flame retardant are added and stirred at high speed for 20s; S3, 82 parts of polymeric MDI are added and stirred for 15s to form a mixture; S4, the mixture is poured into a mold to foam; S5, the mixture is placed in an oven for curing, the curing temperature is 70℃, and the time is set to 5h to obtain a halogen-free flame-retardant polyurethane foam, which is denoted as M3.

[0031] Further, the properties of the halogen-free flame-retardant polyurethane foam prepared by the process are shown in Table 1, wherein the polyurethane foam is placed in a 70℃ oven for aging for 48 hours, and after being placed at room temperature for five days, the change in flame-retardant stability is investigated according to GB-T2406.2-2009; the compression performance is tested according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed in a 70℃ oven for storage for 48 hours, and is stored at-20℃ for 48h, and the dimensional change rate of the sample before and after aging of the polyurethane foam is tested according to GB-T8811-2008, and the dimensional change rate formula is: Wherein, L2 is the length of the sample after aging, and L1 is the length of the sample before aging Example 4 The present application provides a preparation method of a halogen-free phosphorus-based flame-retardant polyurethane foam, and the preparation method specifically comprises: S1, 100 parts of polyol 6305, 1.9 parts of hard foam silicone oil M88108, 3.5 parts of catalyst PC-8, 2.0 parts of water, 25.0 parts of pentafluoropropane are added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 5 parts of phosphine flame retardant DOPO-TBD, 8 parts of phosphine flame retardant DOPO-MeOH and 16 parts of polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 115 parts of polymeric MDI are added and stirred for 15s to form a mixture; S4, the mixture is poured into a mold to foam; S5, the mixture is placed in an oven to cure, the curing temperature is 70℃, and the time is set to 5h, to obtain a halogen-free flame-retardant polyurethane foam, denoted as M4.

[0032] Further, the properties of the halogen-free flame-retardant polyurethane foam prepared by the process are shown in Table 1, wherein the flame-retardant stability change is investigated by placing the polyurethane foam in a 70℃ oven for 48 hours, placing it at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance is tested according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed in a 70℃ oven for 48 hours and stored at -20℃ for 48h, and the length size change rate of the polyurethane foam sample before and after aging is tested according to GB-T8811-2008, and the size change rate formula is: wherein L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0033] Example 5 The present application provides a preparation method of a flame-retardant polyurethane foam containing a halogen-free phosphorus-based flame retardant, and the preparation method specifically comprises: S1, 70 parts of polyol 6305, 30 parts of polyether 635, 1.9 parts of hard foam silicone oil M88108, 4.0 parts of catalyst PC-8, 2.0 parts of water, 25.0 parts of pentafluoropropane are added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 5 parts of phosphine oxide flame retardant DOPO-TBD and 20 parts of polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 109 parts of polymeric MDI are added and stirred for 15s to form a mixture; S4, the mixture is poured into a mold to foam; S5, the mixture is placed in an oven to cure, the curing temperature is 70℃, and the time is set to 5h, to obtain a halogen-free flame-retardant polyurethane foam, denoted as M5.

[0034] Further, the properties of the halogen-free flame-retardant polyurethane foam made by the process are shown in Table 1, wherein the flame-retardant stability change is investigated by placing the polyurethane foam in a 70℃ oven for 48 hours, placing it at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance test is performed according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed in a 70℃ oven for 48 hours and stored at -20℃ for 48 hours, and the length size change rate of the polyurethane foam sample before and after aging is tested according to GB-T8811-2008, and the size change rate formula is: wherein L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0035] Example 6 The present application provides a preparation method of a flame-retardant polyurethane foam containing a halogen-free phosphorus-based flame retardant, and the preparation method specifically comprises: S1, 70 parts of polyol 6305, 30 parts of polyether 635, 1.6 parts of hard foam silicone oil M88108, 3.6 parts of catalyst PC-8, 2.5 parts of water, 20.0 parts of pentafluoropropane and 5 parts of tetrafluoroethane are added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 10 parts of phosphine flame retardant DOPO-TBD and 9 parts of polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 103 parts of polymeric MDI are added and stirred for 15s to form a mixture; S4, the mixture is poured into a mold to foam; S5, the mixture is placed in an oven for curing, the curing temperature is 70℃, and the time is set to 5h to obtain a halogen-free flame-retardant polyurethane foam, which is denoted as M6.

[0036] Further, the properties of the halogen-free flame-retardant polyurethane foam made by the process are shown in Table 1, wherein the flame-retardant stability change is investigated by placing the polyurethane foam in a 70℃ oven for 48 hours, placing it at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance test is performed according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed in a 70℃ oven for 48 hours and stored at -20℃ for 48 hours, and the length size change rate of the polyurethane foam sample before and after aging is tested according to GB-T8811-2008, and the size change rate formula is: wherein L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0037] Example 7 The present application provides a preparation method of a halogen-free phosphorus-based flame-retardant polyurethane foam, which specifically comprises: S1, 100 parts of polyol 6305, 1.6 parts of hard foam silicone oil M88108, 3.8 parts of catalyst PC-8, 2.7 parts of water, 22.0 parts of pentafluoropropane and 3 parts of tetrafluoroethane are added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 12 parts of phosphine flame retardant DOPO-TBD and 7 parts of polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 90 parts of polymeric MDI are added and stirred for 15s to form a mixture; S4, the mixture is poured into a mold to foam; S5, the mixture is placed in an oven for curing, the curing temperature is 70℃, and the time is set to 5h to obtain a halogen-free flame-retardant polyurethane foam, which is recorded as M7.

[0038] Further, the properties of the halogen-free flame-retardant polyurethane foam prepared by the process are shown in Table 1, wherein the flame-retardant stability change is investigated by placing the polyurethane foam in a 70℃ oven for 48 hours, placing it at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance is tested according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed in a 70℃ oven for 48 hours and stored at-20℃ for 48h, and the length size change rate of the polyurethane foam sample before and after aging is tested according to GB-T8811-2008, and the size change rate formula is: Wherein, L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0039] Example 8 The present application provides a preparation method of a halogen-free phosphorus-based flame-retardant polyurethane foam, which specifically comprises: S1, 100 parts of polyol 6305, 2.0 parts of hard foam silicone oil M88108, 3.9 parts of catalyst PC-8, 2.9 parts of water, 24.5 parts of pentafluoropropane are added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 13 parts of phosphine flame retardant DOPO-TBD and 8 parts of polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 85 parts of polymeric MDI are added and stirred for 15s to form a mixture; S4, the mixture is poured into a mold to foam; S5, the mixture is placed into an oven for curing, the curing temperature is 70°C, and the time is set to 5h, to obtain a halogen-free flame-retardant polyurethane foam, denoted as M8.

[0040] Further, the properties of the halogen-free flame-retardant polyurethane foam prepared by the process are shown in Table 1, wherein the flame-retardant stability change is investigated by placing the polyurethane foam into a 70°C oven for aging for 48 hours, placing at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance is tested according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed into a 70°C oven for storage for 48 hours, and stored at -20°C for 48h, and the dimensional change rate of the sample piece before and after aging of the polyurethane foam is tested according to GB-T8811-2008, and the dimensional change rate formula is: wherein L2 is the length of the sample piece after aging, and L1 is the length of the sample piece before aging.

[0041] Comparative Example 1 In addition, a polyurethane foam preparation scheme is provided: S1, 100 parts of polyol 6305, 1.6 parts of hard foam silicone oil M88108, 3.5 parts of catalyst PC-8, 1.5 parts of water, and 25.0 parts of pentafluoropropane are added into a beaker and stirred for 15s to prepare a mixed polyether; S2, 4 parts of phosphine oxide flame retardant DOPO-MEOH and 4 parts of polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 110 parts of polymeric MDI are added and stirred for 10s to form a mixture; S4, the mixture is poured into a mold for foaming; S5, the mixture is placed into an oven for curing, the curing temperature is 70°C, and the time is set to 5h, to obtain a halogen-free flame-retardant polyurethane foam, denoted as M9.

[0042] Further, the properties of the halogen-free flame-retardant polyurethane foam prepared by the process are shown in Table 1, wherein the flame-retardant stability change is investigated by placing the polyurethane foam into a 70°C oven for aging for 48 hours, placing at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance is tested according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed into a 70°C oven for storage for 48 hours, and stored at -20°C for 48h, and the dimensional change rate of the sample piece before and after aging of the polyurethane foam is tested according to GB-T8811-2008, and the dimensional change rate formula is: Wherein, L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0043] Comparative Example 2 Further provided is a polyurethane foam preparation scheme: S1, 100 parts of polyol 6305, 1.6 parts of hard foam silicone oil M88108, 3.5 parts of catalyst PC-8, 1.5 parts of water, 25.0 parts of pentafluoropropane are added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 10 parts of phosphine flame retardant DOPO-MEOH and 28 parts of polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 113 parts of polymeric MDI are added and stirred for 10s to form a mixture; S4, the mixture is poured into a mold to foam; S5, the mixture is placed in an oven for curing, the curing temperature is 70℃, and the time is set to 5h to obtain a halogen-free flame-retardant polyurethane foam, which is denoted as M10.

[0044] Further, the properties of the prepared polyurethane foam are shown in Table 1, wherein the polyurethane foam is placed in a 70℃ oven for 48 hours, and after being placed at room temperature for five days, the flame retardant stability change is investigated according to GB-T2406.2-2009 to test the oxygen index; the compression performance test is carried out according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed in a 70℃ oven for 48 hours and stored at-20℃ for 48 hours, and the size change rate of the sample before and after aging of the polyurethane foam is tested according to GB-T8811-2008, and the size change rate formula is: Wherein, L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0045] Comparative Example 3 Further provided is a polyurethane foam preparation scheme: S1, 100 parts of polyol 6305, 1.8 parts of hard foam silicone oil M88108, 3.2 parts of catalyst PC-8, 1.8 parts of water, 25.0 parts of pentafluoropropane are added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 4 parts of phosphine flame retardant DOPO-TBD and 23 parts of polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 113 parts of polymeric MDI are added and stirred for 15s to form a mixture; S4, the mixture is poured into a mold to foam; S5, the mixture is placed in an oven for curing, the curing temperature is 70℃, and the time is set to 5h to obtain a halogen-free flame-retardant polyurethane foam, which is denoted as M11.

[0046] Further, the prepared polyurethane foam was tested for performance as shown in Table 1, wherein the flame-retardant stability was investigated by placing the polyurethane foam in a 70°C oven for 48 hours, placing it at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance was tested according to GB-T8813-2022; the oxygen index was tested according to GB-T2406.2-2009; the polyurethane foam was placed in a 70°C oven for 48 hours and stored at -20°C for 48 hours, and the dimensional change rate of the sample before and after aging of the polyurethane foam was tested according to GB-T8811-2008, and the dimensional change rate formula was: wherein L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0047] Comparative Example 4 In addition, a polyurethane foam preparation scheme is provided: S1, 100 parts of polyol 6305, 1.6 parts of hard foam silicone oil M88108, 3.6 parts of catalyst PC-8, 1.5 parts of water, and 25.0 parts of pentafluoropropane were added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 12 parts of phosphine oxide flame retardant DOPO-MEOH and 14 parts of TCPP flame retardant were added and stirred at high speed for 30s; S3, 113 parts of polymeric MDI were added and stirred for 10s to form a mixture; S4, the mixture was poured into a mold and foamed; S5, the mixture was placed in an oven for curing, the curing temperature was 70°C, and the time was set to 5h to obtain a halogen-free flame-retardant polyurethane foam, which was denoted as M12.

[0048] Further, the prepared polyurethane foam was tested for performance as shown in Table 1, wherein the flame-retardant stability was investigated by placing the polyurethane foam in a 70°C oven for 48 hours, placing it at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance was tested according to GB-T8813-2022; the oxygen index was tested according to GB-T2406.2-2009; the polyurethane foam was placed in a 70°C oven for 48 hours and stored at -20°C for 48 hours, and the dimensional change rate of the sample before and after aging of the polyurethane foam was tested according to GB-T8811-2008, and the dimensional change rate formula was: wherein L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0049] Comparative Example 5 Further provided is a polyurethane foam preparation scheme: S1, 100 parts of polyol 6305, 1.6 parts of hard foam silicone oil M88108, 3.5 parts of catalyst PC-8, 1.5 parts of water, and 25.0 parts of pentafluoropropane are added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 12 parts of TPP and 13 parts of polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 113 parts of polymeric MDI are added and stirred for 10s to form a mixture; S4, the mixture is poured into a mold and foamed; S5, the mixture is placed in an oven for curing, the curing temperature is 70°C, and the time is set to 5h to obtain a halogen-free flame-retardant polyurethane foam, which is denoted as M13.

[0050] Further, the properties of the prepared polyurethane foam are shown in Table 1, wherein the flame-retardant stability change is investigated by placing the polyurethane foam in a 70°C oven for 48 hours, placing it at room temperature for five days, and testing the oxygen index according to GB-T2406.2-2009; the compression performance is tested according to GB-T8813-2022; the oxygen index is tested according to GB-T2406.2-2009; the polyurethane foam is placed in a 70°C oven for 48 hours and stored at -20°C for 48h, and the length size change rate of the polyurethane foam sample before and after aging is tested according to GB-T8811-2008, and the size change rate formula is: Wherein, L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0051] Comparative Example 6 Further provided is a polyurethane foam preparation scheme: S1, 100 parts of polyol 6305, 1.6 parts of hard foam silicone oil M88108, 3.5 parts of catalyst PC-8, 1.5 parts of water, and 25.0 parts of pentafluoropropane are added in a beaker and stirred for 15s to prepare a mixed polyether; S2, 12 parts of phosphine flame retardant DOPO-MEOH and 13 parts of polyphosphate flame retardant are added and stirred at high speed for 30s; S3, 55 parts of polymeric MDI are added and stirred for 10s to form a mixture for foaming; Thus, the foam does not rise and cannot foam normally.

[0052] Comparative Example 7 Further provided is a polyurethane foam preparation scheme: S1, 100 parts of polyol 6305, 1.6 parts of hard foam silicone oil M88108, 3.5 parts of catalyst PC-8, 1.5 parts of water, 25.0 parts of pentafluoropropane were added in a beaker and stirred for 15 s to prepare a mixed polyether; S2, 12 parts of phosphine flame retardant DOPO-MEOH and 13 parts of polyphosphate flame retardant were added and stirred at high speed for 30 s; S3, 170 parts of polymeric MDI were added and stirred for 10 s to form a mixture and wait for foaming; Therefore, the viscosity of the system is too low, the reaction is too fast, and the foaming fails.

[0053] The raw materials used in the experiment are as follows: DOPO-MEOH, product moisture 0.05%, particle size D50: 2.3 μm; Nantong Yasi Flame Retardant Technology Co., Ltd.; DOPO-TBD was synthesized according to DOI: 10.15925 / j.cnki.issn1005-3360.2023.08.004; product moisture 0.08%, particle size D50: 2.3 μm; polyphosphate, Changzhou Younuo New Material Co., Ltd.; Polyurethane rigid foam polyether 6305, polyurethane rigid foam polyether 635, hard foam silicone oil M88108, Nanjing Meiside Chemical Co., Ltd.; polyurethane rigid foam catalyst is dimethylcyclohexylamine (PC-8), foaming agent is pentafluoropropane (HFC-245fa) or tetrafluoroethane, polymeric MDI, tris (2-chloropropyl) phosphate (TCPP), triphenyl phosphate (TPP) are all purchased through commercial channels.

[0054] The polyurethane foams obtained by M1-M13 above were respectively tested for flame retardant performance, flame retardant stability and compressive strength, and the results are shown in Table 1: Table 1 Performance test of halogen-free flame-retardant polyurethane As can be seen from Table 1, the polyurethane foams (M1-M8) prepared by mixing isocyanate, polyol, phosphorus-based flame retardant composition and auxiliary in certain proportions exhibit excellent compression resistance, flame resistance, flame resistance stability, and low size change rate of the foamed polyurethane foam (<1%), which can be seen from M1-M8. In Comparative Example 1 (M9), the amount of the phosphorus-based flame retardant composition is changed, and the flame resistance of the polyurethane foam is deteriorated; in Comparative Example 2 (M10), the amount of the phosphorus-based flame retardant composition is further changed, and although the flame resistance of the polyurethane foam is maintained, the compression resistance of the polyurethane foam is deteriorated; in Comparative Example 3 (M11), the ratio of the two flame retardants in the phosphorus-based flame retardant composition is changed, and the compression resistance of the obtained polyurethane foam is poor, the thermal size stability of the obtained polyurethane foam is deteriorated, and the use is affected; in Comparative Example 4 (M12) and Comparative Example 5 (M13), the types of the phosphorus-based flame retardant are further changed, the flame resistance of the polyurethane foam is deteriorated, and the flame resistance stability and size stability of the polyurethane foam are also greatly changed. In Comparative Example 6 and Comparative Example 7, the ratio of isocyanate and polyol is changed, which directly leads to foaming failure.

[0055] The above shows and describes the basic principles, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A flame-retardant polyurethane foam comprising a halogen-free phosphorus-based flame retardant, characterized in that: The flame-retardant polyurethane foam comprises, in terms of weight percentage, isocyanate 60-150 parts, polyol 100 parts, phosphorus-based flame retardant composition 10-30 parts, and auxiliary agent 5-38 parts, and the density of the flame-retardant polyurethane foam is 10-120 kg / m 3 .

2. A flame-retardant polyurethane foam comprising a halogen-free phosphorus-based flame retardant according to claim 1, characterized in that: The phosphorus-based flame retardant composition comprises a phosphaphenanthrene flame retardant and a phosphate ester flame retardant, the phosphaphenanthrene flame retardant is a derivative of 9,10-dihydro-9-oxa-10-phosphaphenanthrene oxide, the phosphate ester flame retardant is a polymeric phosphate ester, and the mass ratio of the derivative of 9,10-dihydro-9-oxa-10-phosphaphenanthrene oxide to the polymeric phosphate ester is 1:0.5-1:

4.

3. A flame-retardant polyurethane foam comprising a halogen-free phosphorus-based flame retardant according to claim 2, characterized in that: The phosphaphenanthrene flame retardant is selected as at least one of DOPO-MEOH and DOPO-TBD, the structure of the DOPO-MEOH is as follows: ； The structure of the DOPO-TBD is as follows: 。 4. A flame-retardant polyurethane foam comprising a halogen-free phosphorus-based flame retardant according to claim 2, characterized in that: The particle size D50 of the phosphaphenanthrene flame retardant is less than or equal to 5 μm.

5. A flame-retardant polyurethane foam comprising a halogen-free phosphorus-based flame retardant according to claim 2, characterized in that: The structure of the polymeric phosphate ester is as follows: 。 6. A flame-retardant polyurethane foam comprising a halogen-free phosphorus-based flame retardant according to claim 1, characterized in that: The phosphorus-based flame retardant composition further comprises less than or equal to 0.3% of water.

7. A flame-retardant polyurethane foam comprising a halogen-free phosphorus- based flame retardant according to claim 1, characterized in that: The isocyanate is selected as at least one of toluene diisocyanate and phenylmethane diisocyanate.

8. A flame-retardant polyurethane foam comprising a halogen-free phosphorus- based flame retardant according to claim 1, characterized in that: The polyol is selected as a polyester polyol or a polyether polyol or a mixture of a polyester polyol and a polyether polyol, and the hydroxyl value of the polyol is 20-1000 mg KOH / g.

9. A flame-retardant polyurethane foam comprising a halogen-free phosphorus- based flame retardant according to claim 1, characterized in that: The auxiliary agent is selected as a catalyst, a surfactant and a foaming agent, the catalyst is selected as an organic tin or an amine, the surfactant is selected as a siloxane-alkylene oxide copolymer or other organopolysiloxane, and the foaming agent is selected as at least one of water, cyclohexane or a fluorine-containing foaming agent.

10. A process for the preparation of a flame retarded polyurethane foam comprising a halogen-free phosphorus-based flame retardant according to any one of claims 1 to 9, characterized in that: The preparation method specifically comprises the following steps: S1, adding a polyol, hard foam silicone oil M88108, a catalyst, water and pentafluoropropane into a beaker and stirring for 15 s to obtain a mixed polyether; S2, adding a phosphaphenanthrene flame retardant and a phosphate ester flame retardant and stirring at a high speed for 20-30 s; S3, adding polymeric MDI and stirring for 10 s to form a mixture; S4, pouring the mixture into a mold to foam; S5, placing the mixture into an oven to solidify, the solidification temperature is 70°C, and the time is set to 5 h to obtain a halogen-free flame-retardant polyurethane foam.

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