Reactive organic phosphate flame retardant and preparation method thereof and flame retardant material

Abstract

The present invention relates to the technical field of flame retardant materials, specifically, to a reactive organic phosphate flame retardant and a preparation method thereof and a flame retardant material. The composition of the reactive organic phosphate flame retardant comprises component A and component B; wherein component A comprises a hydrolyzate formed by hydrolysis of a compound shown in the following formula I: wherein R1 and R2 are independently selected from C1-C8 alkyl; component B is selected from a compound shown in the following formula II: wherein R3 is C1-C4 alkyl; the mass ratio of component A and component B is (99.0-99.95): (0.05-1.0). The flame retardant selects component A and component B as batching raw materials, which can improve the compressive strength, bending strength and other mechanical properties of resin materials, especially polyurethane materials, improve its foaming performance, and at the same time, has excellent flame retardant and fireproof properties.

Description

Technical Field

[0001] The invention relates to the technical field of flame retardant materials, and in particular to a reactive organic phosphate flame retardant and a preparation method thereof and a flame retardant material. Background Art

[0002] Synthetic resin is a type of artificially synthesized polymer. The most important application of synthetic resin is to make plastics and foams. Synthetic resins are widely used in many fields such as home furnishings, transportation, electrical appliances, construction and industrial insulation. However, plastics, foams or synthetic resins are very flammable, and the combustion process releases a lot of heat, smoke and toxic gases. Therefore, in many fields and occasions, synthetic resins, plastics and foams are required to be flame retardant, especially halogen-free flame retardant.

[0003] Existing flame retardants are roughly divided into additive flame retardants and reactive flame retardants. The former are mostly phosphates, such as tris(1-chloro-2-propyl) phosphate (TCPP), tris(chloroethyl) phosphate (TCEP) and triethyl phosphate (TEP), bisphenol A bis(diphenyl phosphate) (BDP), etc. Such phosphates are mostly liquids with suitable viscosity and convenient operation and use. They are widely used in industries such as home furnishing and thermal insulation materials. However, after long-term use, such phosphates will precipitate from the surface of synthetic polymer materials, which will reduce the flame retardant properties of polymer materials and also lead to a decrease in their mechanical properties. The molecular structure of reactive flame retardants often contains reactive groups such as active amino groups and / or hydroxyl groups, which can greatly improve the precipitation resistance of flame retardants and enhance the flame retardant stability of polymer materials. For example, the oligomeric phosphates disclosed in patents US5608100 and EP068561. However, this type of flame retardant is mostly made of highly corrosive and moisture-absorbing phosphorus pentoxide and flammable and explosive propylene oxide or ethylene oxide, etc., and there is a problem of high difficulty in process implementation. In addition, the phosphate ester molecular structure of this type of flame retardant contains a large number of POC bonds, and the phosphate ester is very easy to hydrolyze to form an acidic substance, which easily causes the catalyst to deactivate during the polymer foaming process, and also has the defects of inconvenience in storage and use. At the same time, in the process of using reactive flame retardants, it is also found that the mechanical properties such as compressive strength of the materials added with this type of phosphate ester flame retardant are seriously reduced, which limits the use of this type of flame retardant.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a reactive organic phosphate flame retardant and a preparation method and a flame retardant material thereof. The embodiment of the present invention provides a new organic phosphate flame retardant which can improve the mechanical properties of resin materials, especially polyurethane materials, such as compressive strength and flexural strength, improve its foaming performance, and at the same time, has excellent flame retardant and fireproof properties.

[0006] The present invention is achieved in that:

[0007] In a first aspect, the present invention provides a reactive organophosphate flame retardant, wherein the reactive organophosphate flame retardant comprises component A and component B;

[0008] Wherein, the component A comprises a hydrolyzate formed by hydrolysis of the compound represented by the following formula I:

[0009] Wherein, R1 and R2 are independently selected from C1-C8 alkyl;

[0010] The component B is selected from the compound represented by the following formula II:

[0011] Wherein, R3 is a C1-C4 alkyl group;

[0012] The mass ratio of the component A to the component B is (99.0-99.95):(0.05-1.0).

[0013] In a second aspect, the present invention provides a method for preparing the reactive organophosphate flame retardant described in the aforementioned embodiment, comprising: mixing a hydrolysis product formed by hydrolyzing the compound represented by formula I with the compound represented by formula II.

[0014] In a third aspect, the present invention provides a flame retardant material, comprising a base material and the reactive organic phosphate flame retardant described in any one of the aforementioned embodiments;

[0015] Wherein, the matrix material comprises at least one of polyurethane, epoxy resin, polyamide, polyester, polyphenylene ether, polyvinyl chloride, phenolic resin, polyacrylic acid, polystyrene and polyurea.

[0016] The present invention has the following beneficial effects: the reactive organic phosphate flame retardant provided by the embodiment of the present invention can be applied to foaming, maintain its foaming rate and density, and at the same time, can improve the mechanical properties such as compressive strength and bending strength of the foam formed by the resin. It can also play an excellent flame retardant and fireproof effect. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0018] In a first aspect, the present invention provides a reactive organic phosphate flame retardant, wherein the reactive organic phosphate flame retardant comprises component A and component B.

[0019] Specifically, component A includes a hydrolyzate formed by hydrolysis of the compound represented by the following formula I: Wherein, R1 and R2 are independently selected from C1-C8 alkyl groups; preferably C1-C8 unsubstituted alkyl groups, such as C1-C8 straight-chain alkyl groups or C1-C8 branched alkyl groups, and more preferably C1-C4 unsubstituted alkyl groups, such as but not limited to one of methyl, ethyl, propyl, butyl, pentyl, hexyl and octyl groups. For example, preferably one of ethyl, butyl, isobutyl, sec-butyl and tert-butyl groups. And R1 and R2 can be selected from the same group or different groups.

[0020] The hydrolyzate includes at least one of the compounds described in the following structural formula:

[0021]

[0022]

[0023] The content of the compound represented by formula III in the hydrolyzate is higher than 60%; and the total content of the compounds represented by formula III, formula VA and formula VB is relatively high, for example, the total content is higher than 80%; preferably, the sum of the three is higher than 90%. The total content of formula III, formula VA and formula VB is higher than the total content of formula IVA and formula IVB, which makes the reactive organic phosphate flame retardant have better flame retardant properties. The total content of the compounds represented by formula IVA and formula IVB in the hydrolyzate is not higher than 0.4%.

[0024] Studies have found that if the content of the compound shown in Formula VI in the hydrolyzate is too high, the mechanical properties of the foam or plastic (such as polyurethane foam) formed therefrom, such as tensile properties, are reduced. This may be due to the fact that the organic hypophosphite shown in Formula VI is a monofunctional structure, which reduces the cross-linking density of the molecular chain in the polymer (such as polyurethane); therefore, the content of the compound shown in Formula VI in the hydrolyzate is less than 1%. At the same time, the experiment also found that the hydrolyzate also contains a small amount of glycerol by-product, and its content is relatively high, which will reduce the flame retardant efficiency of the organic phosphate flame retardant. In the present invention, the content of glycerol shown in Formula VII in the hydrolyzate is not higher than 2.5%.

[0025] After the hydrolysis reaction of the compound shown in Formula I, the compound shown in Formula III is the main component, and the compounds shown in Formula IVA, IVB, VA, VB, VI and VII are by-products of the hydrolysis reaction. The formation of the above by-products may be that during the hydrolysis reaction of the compound shown in Formula I, some of the products continue to undergo polycondensation reaction.

[0026] The embodiments of the present invention can confirm the structures of the compounds of Formula III, Formula IVA, Formula IVB, Formula VA, Formula VB, Formula VI and Formula VII through appropriate analytical test conditions, such as high performance liquid chromatography-mass spectrometry (HPLC-MS) or gas chromatography-mass spectrometry (GC-MS), combined with nuclear magnetic resonance spectroscopy.

[0027] Furthermore, component B is selected from the compound represented by the following formula II:

[0028] Wherein, R3 is a C1-C4 alkyl group; preferably a C1-C4 unsubstituted alkyl group, for example, a C1-C4 unsubstituted branched alkyl group or a C1-C4 unsubstituted straight alkyl group, for example, one of methyl, ethyl, propyl and butyl.

[0029] The reactive organic phosphate flame retardant provided in the embodiment of the present invention can be used as a flame retardant in polyurethane materials to play a flame retardant and fireproof role. However, the study found that the foaming rate of the reactive organic phosphate flame retardant of component A alone in the foaming process of the polyurethane material is slow, and the obtained polyurethane foam has a lower foam density. Analysis and speculation may be due to the insufficient activity of the hydroxyl group in component A, which delays the reaction of the polyether and the isocyanate. In addition, the study also found that compared with other types of flame retardants with the same phosphorus content, the flame retardant efficiency of component A is lower. Therefore, the inventors have made creative efforts and found that when a small amount of component B is added to component A, the foaming process of the polyurethane foam can be accelerated and the density of the polyurethane foam can be reduced. Compared with the polyurethane foam without adding flame retardant, its foaming time can remain basically unchanged. This undoubtedly brings great convenience to the on-site use and processing of the product. At the same time, the compressive strength, bending strength and other properties of the polyurethane material treated with the reactive organic phosphate flame retardant provided in the embodiment of the present invention are significantly improved. This may be because component B itself has a bifunctional structure and has high reactivity, which is conducive to promoting the reaction of active groups in polyurethane materials. If component B is changed to other organic phosphates, the performance of polyurethane materials using reactive organic phosphate flame retardants may be reduced.

[0030] It should be noted that the reactive organic phosphate flame retardant provided in the embodiment of the invention can be used as a flame retardant not only in the polyurethane material described above, but also in other polymer materials to play a role of flame retardancy and fire prevention. For example, the polymer material includes but is not limited to at least one of epoxy resin, polyamide, polyester, polyphenylene ether, polyvinyl chloride, phenolic resin, polyacrylic acid, polystyrene and polyurea.

[0031] Wherein, the mass ratio of the component A to the component B is (99.0-99.95): (0.05-1.0). For example, it is any value between (99.0-99.95): (0.05-1.0) such as 99.0:1, 99.1:0.9, 99.2:0.8, 99.3:0.7, 99.4:0.6, 99.5:0.5, 99.6:0.4, 99.7:0.3, 99.8:0.2, 99.9:0.1 and 99.95:0.05. If the addition amount of component B is too high, the foaming rate is too fast, and the mechanical properties of the obtained foam or plastic or other flame retardant materials, such as tensile strength and impact strength, are reduced.

[0032] Furthermore, the reactive organic phosphate flame retardant also contains a certain amount of water, and the water content in the reactive organic phosphate flame retardant is less than 0.3% by weight; further preferably, the water content in the reactive organic phosphate flame retardant is less than 0.1%. Higher water content will affect the use of the reactive organic phosphate flame retardant, such as causing abnormal foaming process of polymers (such as polyurethane).

[0033] In a second aspect, an embodiment of the present invention provides a method for preparing the above-mentioned reactive organic phosphate flame retardant, comprising: mixing a hydrolysis product formed by hydrolyzing the compound represented by formula I with the compound represented by formula II.

[0034] The specific steps are as follows:

[0035] S1, hydrolysis reaction;

[0036] The compound shown in formula I (i.e., organic glycidyl hypophosphite) is subjected to a hydrolysis reaction under acidic conditions. The compound shown in formula I can be synthesized by referring to the method of patent CN112778368.

[0037] Specifically, the organic glycidyl hypophosphite is heated to a certain temperature, then mixed with water containing an acidic catalyst, and stirred for 2-8 hours to terminate the reaction, and then the water is removed to form component A.

[0038] The water containing the acidic catalyst may be added all at once or in a gradual dropwise manner.

[0039] The temperature of the hydrolysis reaction is 30-100°C; for example, any value between 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C and 100°C. If the hydrolysis temperature is lower than 30°C, the reaction rate is slow; when the temperature is higher than 100°C, the side reactions increase, and the content of the main product of formula III decreases, which affects the use effect of the final organic phosphate, such as affecting the bending strength of the flame-retardant polyurethane material thereof.

[0040] The acidic catalyst includes at least one of an inorganic acid, an organic acid and an acid salt. Specifically, it can be one or more of sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, phosphorous acid, formic acid, acetic acid, sodium hydrogen sulfate, potassium hydrogen sulfate and an acidic ion exchange resin; more preferably, it can be one or more of sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid and an acidic ion exchange resin.

[0041] The amount of the acidic catalyst is 0.001-0.1% of the mass of the compound represented by Formula I. For example, it is any value between 0.001%, 0.005%, 0.01%, 0.05% and 0.1%, etc. A higher amount of catalyst can promote the occurrence of the hydrolysis reaction.

[0042] The amount of water used is 0.6-3.0 times the molar amount of the compound represented by formula I; for example, it is any value between 0.6-3.0 times, such as 0.6 times, 1.5 times, 2 times, 2.5 times and 3.0 times.

[0043] Component A and component B are then mixed.

[0044] It should be noted that when the reactive organic phosphate flame retardant is used in a polymer material, component A and component B can be fully pre-mixed and then added to the polymer material or its precursor; component A and component B can also be added to the polymer material or its precursor separately, and the final flame retardant material contains a composition composed of component A and component B.

[0045] The aforementioned precursors can be raw materials for preparing polymer materials, or can be premixes of raw materials for preparing polymer materials. For example, when preparing polyurethane, the raw material polyether used can be expressed as a precursor of the polyurethane material.

[0046] Therefore, in a third aspect, an embodiment of the present invention provides a flame retardant material, which includes a base material and the reactive organic phosphate flame retardant described in any one of the aforementioned embodiments.

[0047] The weight proportion of the matrix material in the flame retardant material is 60-97wt%, for example, 60wt%, 70wt%, 80wt%, 90wt%, 95wt% and 97wt%, any value between 60-97wt% or a range between any two values, for example, preferably 60-95wt%.

[0048] The weight proportion of the reactive organic phosphate flame retardant in the flame retardant material is 3-40wt%, for example, 3wt%, 8wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt% and 40wt%, etc., any value between 3-40wt% or a range value between any two values. For example, it is preferably 8-35wt%, or preferably 5-40wt%. Here, if the amount of reactive organic phosphate flame retardant added is low, it will not have a flame retardant effect. If the amount added is too high, it will affect other properties of the flame retardant material, such as reducing the mechanical properties of the flame retardant material. The specific amount of reactive organic phosphate flame retardant used within the above range depends on the structure of the base material.

[0049] The matrix material includes at least one of polyurethane, epoxy resin, polyamide, polyester, polyphenylene ether, polyvinyl chloride, phenolic resin, polyacrylic acid, polystyrene and polyurea.

[0050] The polyurethane matrix material is a high molecular polymer generated by the reaction of polyols, isocyanates, etc., and is selected from at least one of polyester polyurethane, polyether polyurethane, polycarbonate polyurethane, and polycaprolactone polyurethane.

[0051] Furthermore, the flame retardant material further comprises a functional additive, and the mass content of the functional additive in the flame retardant material is 5-40%.

[0052] The functional additives are selected from at least one of a reinforcing agent, an anti-dripping agent, a light stabilizer, a heat stabilizer, a lubricant, a pigment, a carbon-forming catalyst, an antistatic agent, a hydrolysis stabilizer, a chain extender, a plasticizer, a solubilizer, an inorganic filler, an organic filler, an antioxidant, and an antibacterial agent.

[0053] The flame retardant material also includes other flame retardants X. The mass content of the flame retardant X in the flame retardant material is 0.1-10%.

[0054] The flame retardant X is selected from at least one of a phosphorus flame retardant and a nitrogen flame retardant. For example, the phosphorus flame retardant is selected from at least one of a phosphate ester, a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative, and a hexachlorocyclotriphosphazene derivative. Optionally, the phosphate ester is triethyl phosphate or dimethyl methylphosphonate.

[0055] The nitrogen-based flame retardant is selected from at least one of melamine cyanurate, melamine polyphosphate, and etherified melamine formaldehyde resin.

[0056] The raw materials and tests used in the embodiments of the present invention are as follows:

[0057] (1) Dialkylphosphinate glycidyl esters (including diethylphosphinate glycidyl ester and ethylbutylphosphinate glycidyl ester), diethylphosphinate chloride, methylphosphonic acid, ethylphosphonic acid, Jiangsu Liside New Materials Co., Ltd.

[0058] The structure of the methylphosphonic acid used is:

[0059] The structure of ethyl phosphate is:

[0060] The structure of phenylphosphonic acid is:

[0061] (2) Glycerol monohydrate, sulfuric acid, acidic ion exchange resin, Shanghai Aladdin Biochemical Technology Co., Ltd.

[0062] (3) Polyurethane rigid foam polyether 6305, rigid foam silicone oil M88108, Nanjing Meside Chemical Co., Ltd.

[0063] (4) The polyurethane rigid foam catalyst is dimethylcyclohexylamine (PC-8), and the blowing agent is pentafluoropropane (HFC-245fa), polymeric MDI, triethyl phosphate (TEP), dimethyl methyl phosphate (DMMP), and tris(2-chloropropyl) phosphate (TCPP), which are purchased through commercial channels.

[0064] test:

[0065] (1) Moisture determination: The test was carried out using the Karl Fischer method.

[0066] (2) 1 H NMR, 31 P NMR test: The test was carried out using a BRUKER AVANCE 400 instrument.

[0067] (3) GC-MS test: Angilent-8860-5977 gas chromatography-mass spectrometry instrument was used for testing.

[0068] (4) Test of dialkyl hypophosphorous acid content: An Angilent-1260-GG125B liquid chromatography-mass spectrometry instrument was used for testing.

[0069] The features and properties of the present invention are further described in detail below in conjunction with the examples. Unless otherwise specified, all percentages in the following examples are by weight.

[0070] Synthesis example 1

[0071] Synthesis of dialkyl hypophosphites:

[0072] At 90°C, 13.9 g of 0.005% dilute sulfuric acid solution was slowly added to 100.3% dialkyl glycidyl hypophosphite (containing 98.5% diethyl glycidyl hypophosphite and 1.5% ethyl butyl glycidyl hypophosphite) solution. 31 The reaction process was monitored by P NMR method. The addition was completed within about 1 hour. After the addition was completed, stirring was continued for 5 hours to terminate the reaction. Excess water was removed by rotary evaporation to obtain dialkyl hypophosphite, i.e. component A.

[0073] Synthesis example 2

[0074] Synthesis of dialkyl hypophosphites:

[0075] At 90°C, 28.2 g of 0.02% dilute sulfuric acid solution was slowly added to a 100.1% mixed solution of dialkyl glycidyl hypophosphite (containing 98% of diethyl glycidyl hypophosphite and 2% of ethyl butyl glycidyl hypophosphite). 1 The reaction process was monitored by P NMR. The addition was completed within about 2 hours. After the addition was completed, stirring was continued for 5 hours to terminate the reaction. Excess water was removed by rotary evaporation to obtain dialkyl hypophosphite, i.e. component A.

[0076] Synthesis example 3

[0077] Synthesis of dialkyl hypophosphites:

[0078] At 50°C, 6.2 g of 1.6% dilute sulfuric acid solution was slowly added to 100.9 g of dialkyl glycidyl hypophosphite (containing 98% diethyl glycidyl hypophosphite and 2% ethylbutyl glycidyl hypophosphite) solution. 31 The reaction process was monitored by PNMR method. The addition was completed within about 1 hour. After the addition was completed, stirring was continued for 2 hours to terminate the reaction. Excess water was removed by rotary evaporation to obtain dialkyl hypophosphite, i.e. component A.

[0079] Synthesis example 4

[0080] Synthesis of dialkyl hypophosphites:

[0081] At 80°C, 13.2 g of 0.002% dilute sulfuric acid solution was slowly added to 100.6 g of dialkyl glycidyl hypophosphite (containing 98% diethyl glycidyl hypophosphite and 2% ethylbutyl glycidyl hypophosphite) solution. 31 The reaction process was monitored by P NMR method. The addition was completed within about 2 hours. After the addition was completed, stirring was continued for 6 hours to terminate the reaction. Excess water was removed by rotary evaporation to obtain dialkyl hypophosphite, i.e. component A.

[0082] Synthesis example 5

[0083] Synthesis of organophosphite having formula VIII:

[0084] 1) 161.6 g of diethylphosphinoyl chloride was mixed with 300 ml of toluene to obtain an M solution.

[0085] 2) At the same time, 113.5 g of diglycerol and 25.6 g of N,N-dimethyl-p-toluidine were dissolved in 120 ml of toluene to obtain solution N.

[0086] 3) At 98°C, slowly add the M solution into the N solution through a dropping funnel, start stirring, and use 31 The reaction process was monitored by P NMR method. The addition was completed within about 2 hours. After the addition was completed, stirring was continued for 2 hours to terminate the reaction. The generated N, N-dimethyl-p-toluidine salt was filtered out, and the solvent was removed by rotary evaporation. The above solution was added to 400 ml of a mixed solution of n-hexane / toluene (mass ratio 5:1), and the generated N, N-dimethyl-p-toluidine salt was filtered out again, and the solvent was removed by rotary evaporation to obtain an organic hypophosphite of formula VIII with a content of 92%.

[0087]

[0088] Synthesis example 6

[0089] Synthesis of the organophosphite having formula IX:

[0090] 1) 158.9 g of diethylphosphinoyl chloride was mixed with 200 ml of toluene to obtain an M solution.

[0091] 2) Meanwhile, 30 g of glycerol and 5.6 g of N,N-dimethyl-p-toluidine were dissolved in 90 ml of toluene to obtain solution N.

[0092] 3) At 110°C, slowly add the M solution into the N solution through a dropping funnel, start stirring, and use 31 The reaction process was monitored by P NMR. The addition was completed within about 2 hours. After the addition was completed, stirring was continued for 2 hours to terminate the reaction. The generated N, N-dimethyl-p-toluidine salt was filtered out, the solvent was removed by rotary evaporation, and the solution was added to 350 ml of a mixed solution of n-hexane / toluene (mass ratio 5:1), the generated N, N-dimethyl-p-toluidine salt was filtered out again, and the solvent was removed by rotary evaporation to obtain diethyl hypophosphite of formula IX, with a content of 91%.

[0093]

[0094] Example 1

[0095] The embodiment of the present invention provides a reactive organic phosphate flame retardant S1, which is prepared as follows:

[0096] 99.2 g of the dialkyl hypophosphite formed in Synthesis Example 1, namely component A, and 0.06 g of ethyl phosphoric acid, namely component B, were mixed and stirred thoroughly to form a reactive organic phosphate flame retardant S1. The moisture content of the reactive organic phosphate flame retardant S1 was 0.09%.

[0097] The composition of S1 is as follows:

[0098]

[0099] Example 2

[0100] The embodiment of the present invention provides a reactive organic phosphate flame retardant S2, which is prepared as follows:

[0101] 99.6 g of the dialkyl hypophosphite formed in Synthesis Example 2, namely component A, and 0.2 g of ethyl phosphoric acid, namely component B, were mixed and stirred sufficiently to obtain a reactive organic phosphate flame retardant S2, wherein the moisture content of the reactive organic phosphate flame retardant S2 was 0.10%.

[0102] The composition of S2 is as follows:

[0103]

[0104] Example 3

[0105] The embodiment of the present invention provides a reactive organic phosphate flame retardant S3, which is prepared as follows:

[0106] 99.3 g of the dialkyl hypophosphite formed in Synthesis Example 3, namely component A, and 0.9 g of methyl phosphoric acid, namely component B, were mixed and stirred sufficiently to obtain a reactive organic phosphate flame retardant S3, whose moisture content was 0.1%.

[0107] The composition of S3 is as follows:

[0108]

[0109] Example 4

[0110] The embodiment of the present invention provides a reactive organic phosphate flame retardant S4, which is prepared as follows:

[0111] 99.0 g of the dialkyl hypophosphite formed in Synthesis Example 4, namely component A, and 0.1 g of ethyl phosphoric acid, namely component B, were mixed and stirred sufficiently to obtain a reactive organic phosphate flame retardant S4, the moisture content of which was 0.16%.

[0112] The composition of S4 is as follows:

[0113]

[0114] Example 5

[0115] The embodiment of the present invention provides a reactive organic phosphate flame retardant S5, which is prepared as follows:

[0116] 99.6 g of the dialkyl hypophosphite formed in Synthesis Example 4, namely component A, 0.1 g of ethyl phosphoric acid, namely component B, and 5.1 g of triethyl phosphate were mixed and stirred thoroughly to obtain a reactive organic phosphate flame retardant S5, whose moisture content was 0.06%.

[0117] The composition of S5 is as follows:

[0118]

[0119] Example 6

[0120] The embodiment of the present invention provides a reactive organic phosphate flame retardant S6, which is prepared as follows:

[0121] 99.6 g of the dialkyl hypophosphite formed in Synthesis Example 4, i.e., component A, was mixed with 0.1 g of ethyl phosphoric acid, i.e., component B, and 3.3 g of dimethyl methyl phosphate, and stirred thoroughly to obtain a reactive organic phosphate flame retardant S6, whose moisture content was 0.08%.

[0122] The composition of S6 is as follows:

[0123]

[0124] Comparative Example 1

[0125] The dialkyl hypophosphite formed in Synthesis Example 1, namely component A, was used as a flame retardant and was recorded as flame retardant S7.

[0126] Comparative Example 2

[0127] The dialkyl hypophosphite formed in Synthesis Example 2, namely component A, was used as a flame retardant and was recorded as flame retardant S8.

[0128] Comparative Example 3

[0129] This comparative example provides a flame retardant S9, which is prepared as follows:

[0130] 99.8 g of the dialkyl hypophosphite formed in Synthesis Example 2, namely component A, and 0.5 g of ethyl phosphoric acid, namely component B, were mixed and stirred sufficiently to obtain a reactive organic phosphate flame retardant S9, the moisture content of which was 0.10%.

[0131] The composition of S9 is as follows:

[0132]

[0133] Comparative Example 4

[0134] This comparative example provides a flame retardant S10, which is prepared as follows:

[0135] The reactive organic phosphate flame retardant S1 of Example 1 and the organic hypophosphite of Synthesis Example 5 were mixed at a mass ratio of 6:4 and stirred thoroughly to obtain a reactive organic phosphate flame retardant S10, the moisture content of which was 0.13%.

[0136] The composition of S10 is as follows:

[0137]

[0138] Comparative Example 5

[0139] This comparative example provides a flame retardant S11, which is prepared as follows:

[0140] The reactive organic phosphate flame retardant S1 of Example 1 and the organic hypophosphite of Synthesis Example 5 were mixed in a mass ratio of 4:6 and stirred thoroughly to obtain a reactive organic phosphate flame retardant S11, the moisture content of which was 0.05%.

[0141] The composition of S11 is as follows:

[0142]

[0143] Comparative Example 6

[0144] This comparative example provides a flame retardant S12, which is prepared as follows:

[0145] The reactive organic phosphate flame retardant S1 of Example 1 and the organic hypophosphite of Synthesis Example 6 were mixed at a mass ratio of 9.5:0.5 and stirred thoroughly to obtain a reactive organic phosphate flame retardant S12, the moisture content of which was 0.07%.

[0146] The composition of S12 is as follows:

[0147]

[0148] Comparative Example 7

[0149] The flame retardant TCPP is selected and recorded as flame retardant S13.

[0150] Comparative Example 8

[0151] This comparative example provides a flame retardant S14, which is prepared as follows:

[0152] 99.8 g of the dialkyl hypophosphite formed in Synthesis Example 2, namely component A, was mixed with 0.8 g of phenyl phosphoric acid, and the mixture was stirred thoroughly to obtain a reactive organic phosphate flame retardant S14, the moisture content of which was 0.13%.

[0153] The composition of S14 is as follows:

[0154]

[0155] Test example

[0156] Add polyether 6305, rigid foam silicone oil M88108, catalyst PC-8, water, and blowing agent HFC-245fa into a beaker at a mass ratio of 72:1.6:3.5:1.5:24.4, and stir at high speed for 20 seconds to obtain a mixed polyether; add the reactive organic phosphate flame retardant of the above-mentioned Examples 1-6 and the flame retardant of Comparative Examples 1-7. Continue to stir at high speed for 30 seconds with a high-speed stirrer to mix them evenly, then add polymerized MDI to the resulting mixed system, stir again for 10 seconds with a high-speed stirrer, and pour the mixture into a mold after it turns white to allow it to foam freely, record the milky time and the drawing time, and after the reaction is complete, put it into a 70°C oven for aging for 5 hours to obtain a polyurethane foam. The components and their specific composition ratios are as follows:

[0157]

[0158] The performance indicators of flame retardant polyurethane foam are as follows:

[0159] 1) Flame retardant properties:

[0160] The prepared M1-M14 polyurethane foams were cut into specific sizes, and the oxygen index was tested according to GB-T2406.2-2009 to examine the flame retardant properties.

[0161] 2) Foaming rate (milky time and drawing time during foaming process).

[0162] The time it takes for the surface of the foam to turn milky white after the polyurethane stock solution is foamed (milky time) and the time it takes for the glass rod to reach wire drawing when it is inserted and pulled back during the foaming process (wire drawing time) were recorded.

[0163] 3) Mechanical properties:

[0164] The obtained M1-M14 polyurethane foams were cut into specific sizes and tested for maximum bending load and compressive strength according to GB-T8811-2008. The test results are as follows:

[0165]

[0166] As can be seen from the above table, when component A and component B are mixed in a certain proportion, the reactive organic phosphate flame retardant obtained is used in polyurethane, and the milky time and drawing time of the polyurethane foam are close to those of the blank sample; the obtained polyurethane foam shows excellent flame retardant properties, maximum bending load, and compressive strength, which can be seen from M1-M6. The types and addition amounts of component A and component B are also very important. In Comparative Examples 1 and 2, when component A is used alone, the milky time and drawing time of the polyurethane foam become longer, affecting the use; in Comparative Example 3, more component B is added, and the maximum bending load and compressive strength of the polyurethane foam decrease significantly. In addition, the composition of the organophosphorus flame retardant is also very important. In Comparative Examples 4 and 5, the content of the IVA structural flame retardant is increased, and the flame retardant properties (oxygen index) of the obtained polyurethane foam decrease. In Comparative Example 6, after increasing the content of the flame retardant of Formula VI structure, the maximum bending load and compressive strength of the polyurethane foam decreased seriously; and compared with the common flame retardant and the blank sample (Comparative Example 7, blank), the organic phosphate flame retardant (Examples 1-4) showed higher flame retardant efficiency. In Comparative Example 8, when replacing component B with compounds of other structures, the milky time and drawing time of the foam during the polyurethane foaming process were not significantly improved.

[0167] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A reactive organophosphate flame retardant, characterized in that: The reactive organic phosphate flame retardant comprises component A and component B; Wherein, the component A comprises a hydrolyzate formed by hydrolysis of the compound represented by the following formula I: Formula I; wherein R1 and R2 are independently selected from C1-C8 alkyl; The component B is selected from the compound represented by the following formula II: Formula II, wherein R3 is a C1-C4 alkyl group; The mass ratio of the component A to the component B is (99.0-99.95): (0.05-1.0); The hydrolyzate is selected from the compounds described in the following structural formula: Formula III Formula IVA Formula IVB VA VB Form VI Formula VII; Wherein, the content of the compound represented by formula III in the hydrolyzate is higher than 60%; The total content of the compounds represented by formula IVA and formula IVB in the hydrolyzate is not higher than 0.4%; The total content of the compounds represented by formula III, formula VA and formula VB in the hydrolyzate is higher than 80%; The content of the compound represented by formula VI in the hydrolyzate is less than 1%; The content of the compound represented by formula VII in the hydrolyzate is not higher than 2.5%.

2. The reactive organic phosphate flame retardant according to claim 1, characterized in that: R1 and R2 are independently selected from C1-C8 unsubstituted alkyl; R3 is a C1-C4 unsubstituted alkyl group.

3. The reactive organic phosphate flame retardant according to claim 1, characterized in that: The moisture content in the reactive organophosphate flame retardant is less than 0.3%.

4. A method for preparing the reactive organophosphate flame retardant according to claim 1, characterized in that: include: The hydrolysis product formed by hydrolyzing the compound represented by formula I and the compound represented by formula II are mixed.

5. The preparation method according to claim 4, characterized in that: The hydrolysis comprises: mixing the compound represented by formula I, an acidic catalyst and water to carry out a hydrolysis reaction; Wherein, the temperature of the hydrolysis reaction is 30-100°C; The acidic catalyst includes at least one of an inorganic acid, an organic acid and an acid salt; The amount of water used is 0.6-3.0 times the molar amount of the compound represented by formula I; The amount of the acidic catalyst used is 0.001-0.1% by mass of the compound represented by formula I.

6. The preparation method according to claim 5, characterized in that: The acidic catalyst includes one or more of sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, phosphorous acid, formic acid, acetic acid, sodium bisulfate, potassium bisulfate and acidic ion exchange resin.

7. A flame retardant material, characterized in that: It comprises a base material and the reactive organic phosphate flame retardant according to any one of claims 1 to 3, Wherein, the matrix material comprises at least one of polyurethane, epoxy resin, polyamide, polyester, polyphenylene ether, polyvinyl chloride, phenolic resin, polyacrylic acid, polystyrene and polyurea.

8. The flame retardant material according to claim 7, characterized in that: The weight proportions of the reactive organic phosphate flame retardant and the matrix material in the flame retardant material are respectively: reactive organic phosphate flame retardant: 3-40wt%, matrix material: 60-97wt%.

9. The flame retardant material according to claim 7, characterized in that: The flame retardant material further includes one or more of a functional additive and a flame retardant X, wherein: The mass content of the functional additive in the flame retardant material is 5-40%; The functional additives include at least one of a reinforcing agent, an anti-dripping agent, a light stabilizer, a heat stabilizer, a lubricant, a pigment, a carbon-forming catalyst, an antistatic agent, a hydrolysis stabilizer, a chain extender, a plasticizer, a solubilizer, an inorganic filler, an organic filler, an antioxidant and an antibacterial agent; The mass content of the flame retardant X in the flame retardant material is 0.1-10%; The flame retardant X is selected from at least one of a phosphorus-based flame retardant and a nitrogen-based flame retardant.

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