Organic hypophosphite flame retardant, preparation method therefor, and flame-retardant polymer material

Abstract

The present invention provides an organic hypophosphite flame retardant as shown in formula (I). Compared with the prior art, the flame retardant provided by the present invention contains an aryl group, has high stability, relatively high phosphorus content and relatively high flame retardance, can be used for flame retardance of various high polymer materials such as polyurethane, epoxy resin and unsaturated polyester, and especially can endow a polyurethane material with good flame-retardant stability and good mechanical properties when being applied to polyurethane.

Description

An organic hypophosphite flame retardant, preparation method thereof and flame retardant polymer material

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on March 25, 2024, with application number 202410346835.6 and invention name “An organic hypophosphite flame retardant, its preparation method and flame retardant polymer material”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The invention belongs to the technical field of polymer materials, and in particular relates to an organic hypophosphite flame retardant, a preparation method thereof, and a flame retardant polymer material. Background Art

[0003] A common method for improving the flame retardancy of polymer materials is to directly add flame retardants. Phosphate ester flame retardants are the most widely used and widely applied of the phosphorus-based flame retardants. They are typically obtained by directly reacting phosphorus oxychloride, phosphorus trichloride, or phosphorus pentoxide with the corresponding alcohols, phenols, or epoxy compounds. These phosphate esters offer high flame retardancy and are easy to process and use. They are widely used in a variety of thermosetting and thermoplastic polymer materials, including epoxy resins, polyurethane resins, polycarbonates, and polyesters.

[0004] However, traditional phosphate ester flame retardants, such as TCPP, still contain halogens and cannot meet the current flame retardancy requirements for halogen-free polymer materials. Furthermore, most of these phosphate esters contain a high number of easily hydrolyzed POC bonds. After long-term use, these flame retardants are prone to decomposition, resulting in a decrease in the flame retardancy of the polymer. Furthermore, phosphate esters typically have a certain plasticizing effect. While meeting the flame retardancy requirements, this often leads to a decrease in the plasticity and mechanical properties of the flame-retarded polymer. Therefore, the industry urgently needs to develop a halogen-free flame retardant with excellent flame stability and superior mechanical properties. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide an organic hypophosphite flame retardant with high flame retardant stability and mechanical properties, a preparation method thereof and a flame retardant polymer material.

[0006] The present invention provides an organic hypophosphite flame retardant, as shown in formula (I):

[0007] Wherein, R1 and R2 are each independently selected from a C1 to C6 alkyl group;

[0008] R3 is selected from C1 to C4 alkylene;

[0009] n is the number of substituents, and is an integer selected from 0 to 3.

[0010] Preferably, n is 1 or 2.

[0011] Preferably, the acid value is less than or equal to 50 mgKOH / g.

[0012] Preferably, as shown in formula (I-1) to formula (I-8):

[0013] The present invention also provides a method for preparing an organic hypophosphite flame retardant, comprising the following steps:

[0014] S1) mixing a dialkylphosphinate halide represented by formula (II) with a first organic solvent to obtain a solution A;

[0015] Mixing an aryl alcohol represented by formula (III), an amine catalyst and a second organic solvent to obtain a solution B;

[0016] S2) mixing solution A with solution B to react to obtain an organic hypophosphite flame retardant represented by formula (I);

[0017] Wherein, R1 and R2 are each independently selected from a C1 to C6 alkyl group;

[0018] R3 is selected from C1 to C4 alkylene;

[0019] X is a halogen atom;

[0020] n is the number of substituents, and is an integer selected from 0 to 3.

[0021] The present invention also provides a flame retardant polymer material, comprising the above-mentioned organic hypophosphite flame retardant and the polymer material.

[0022] Preferably, the mass of the organic hypophosphite flame retardant is 3% to 40% of the mass of the flame retardant polymer material.

[0023] Preferably, it further comprises a polymer material; the mass of the polymer material is 60% to 97% of the mass of the flame retardant polymer material.

[0024] Preferably, other flame retardants are also included; the mass of the other flame retardants is 0.5% to 20% of the mass of the flame retardant polymer material.

[0025] Preferably, the other flame retardants are selected from phosphorus-based flame retardants and / or nitrogen-based flame retardants; the phosphorus-based flame retardants are selected from one or more of phosphates, phosphazenes, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivatives.

[0026] Preferably, the polymer material is selected from one or more of polyurethane, unsaturated polyester resin, epoxy resin, polyolefin, polystyrene olefin, polyamide, polyester, polyphenylene ether, polyvinyl chloride and polyacrylic acid.

[0027] The present invention provides an organic hypophosphite flame retardant, as shown in formula (I). Compared with the prior art, the flame retardant provided by the present invention contains aromatic groups with high stability and a high phosphorus content, resulting in high flame retardancy. It can be used to flame retard a variety of polymer materials such as polyurethane, epoxy resin, and unsaturated polyester. In particular, when used in polyurethane, it can impart good flame retardant stability and good mechanical properties to the polyurethane material. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is an HNMR diagram of the product obtained in Example 1 of the present invention;

[0029] FIG2 is an HNMR diagram of the product obtained in Example 3 of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] The present invention provides an organic hypophosphite flame retardant, as shown in formula (I):

[0032] Wherein, R1 and R2 are each independently a C1-C6 alkyl group, preferably a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group; in the present invention, the propyl group, the butyl group, the pentyl group and the hexyl group may be a straight chain or a branched alkyl group, without any special restrictions; the types of R1 and R2 may be the same or different, without any special restrictions; more specifically, in one embodiment provided by the present invention, R1 and R2 are ethyl groups; in another embodiment provided by the present invention, one of R1 and R2 is a butyl group and the other is an ethyl group.

[0033] R3 is a C1-C4 alkylene group, which may be a linear alkylene group or a branched alkylene group, and is not particularly limited. In the present invention, it is preferably a methylene group, an ethylene group, a propylene group or a butylene group, and more preferably a methylene group, an ethylene group or a propylene group.

[0034] n is the number of substituents, and is an integer of 0 to 3, specifically 0, 1, 2, 3; preferably 0, 1, 2; and more preferably 1 or 2.

[0035] In a specific embodiment provided by the present invention, the organic hypophosphite flame retardant is as shown in Formula (I-1) to Formula (I-8):

[0036] According to the present invention, the acid value of the organic hypophosphite flame retardant is preferably less than or equal to 50 mgKOH / g, more preferably less than or equal to 40 mgKOH / g, even more preferably less than or equal to 30 mgKOH / g, even more preferably less than or equal to 20 mgKOH / g, even more preferably less than or equal to 10 mgKOH / g, and most preferably less than or equal to 8 mgKOH / g; in some embodiments provided by the present invention, the acid value of the organic hypophosphite flame retardant is specifically 3.7 mgKOH / g, 7.6 mgKOH / g, 5.1 mgKOH / g, 3.6 mgKOH / g or 4.9 mgKOH / g.

[0037] The flame retardant provided by the present invention has high aromatic stability and a high phosphorus content, and has high flame retardancy. It can be used for flame retardancy of various polymer materials such as polyurethane, epoxy resin, and unsaturated polyester. In particular, when used in polyurethane, it can give the polyurethane material good flame retardant stability and good mechanical properties.

[0038] The present invention also provides a method for preparing an organic hypophosphite flame retardant, comprising the following steps: S1) mixing a dialkyl hypophosphite halide represented by formula (II) with a first organic solvent to obtain a solution A; mixing an aromatic alcohol represented by formula (III), an amine catalyst, and a second organic solvent to obtain a solution B; S2) mixing solution A with solution B to react to obtain an organic hypophosphite flame retardant represented by formula (I);

[0039] Wherein, R1 and R2 are each independently a C1-C6 alkyl group, preferably a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group; in the present invention, the propyl group, the butyl group, the pentyl group and the hexyl group may be a straight chain or a branched alkyl group, without any special restrictions; the types of R1 and R2 may be the same or different, without any special restrictions; more specifically, in one embodiment provided by the present invention, R1 and R2 are ethyl groups; in another embodiment provided by the present invention, one of R1 and R2 is a butyl group and the other is an ethyl group.

[0040] R3 is a C1-C4 alkylene group, which may be a linear alkylene group or a branched alkylene group, and is not particularly limited. In the present invention, it is preferably a methylene group, an ethylene group, a propylene group or a butylene group, and more preferably a methylene group, an ethylene group or a propylene group.

[0041] X is a halogen atom, preferably chlorine.

[0042] n represents the number of substituents, and is an integer of 0 to 3, specifically 0, 1, 2, and 3, preferably 0, 1, and 2, and more preferably 1 or 2.

[0043] The present invention has no particular limitation on the sources of all raw materials, and any commercially available raw materials may be used.

[0044] The dialkyl hypophosphite halide represented by formula (II) is mixed with a first organic solvent to obtain solution A; the first organic solvent is an organic solvent well known to those skilled in the art and is not particularly limited. In the present invention, it is preferably one or more of toluene, xylene, chloroalkane, tetrahydrofuran, alcohol ether, acetonitrile and dimethyl sulfoxide.

[0045] An aromatic alcohol represented by formula (III), an amine catalyst, and a second organic solvent are mixed to obtain a solution B; the amine catalyst is preferably triethylamine and / or N,N-dimethyl-p-toluidine; the second organic solvent is any organic solvent well known to those skilled in the art and is not particularly limited. In the present invention, it is preferably one or more of toluene, xylene, chloroalkane, tetrahydrofuran, alcohol ether, acetonitrile, and dimethyl sulfoxide; the mass of the amine catalyst is preferably 20% to 50% of the mass of the aromatic alcohol represented by formula (III), and more preferably 24% to 48%.

[0046] Solution A and solution B are mixed to react; in the present invention, solution A is preferably slowly added to solution B and mixed; the addition of solution A is preferably completed within 0.5 to 2 hours; in some embodiments provided by the present invention, the addition of solution A is specifically completed within 1 hour, 0.5 hours, 1.5 hours, 2 hours or 1.2 hours; the mixing temperature is preferably 40°C to 120°C; and the reaction time is preferably 2 to 4 hours.

[0047] After the reaction is completed, it is preferably filtered, the solvent is removed, and the organic hypophosphite flame retardant represented by formula (I) is obtained by vacuum distillation or extraction separation; the method for removing the solvent is a method well known to those skilled in the art and is not particularly limited. In the present invention, the solvent is preferably removed by rotary evaporation; after removing the solvent, it is preferably filtered again, and then vacuum distillation or extraction separation is performed; the solvent used for the extraction separation is an organic solvent well known to those skilled in the art and is not particularly limited. In the present invention, dichloromethane is preferably used.

[0048] The present invention also provides the use of the organic hypophosphite flame retardant represented by the above formula (I) as a flame retardant for polymer materials.

[0049] The organic hypophosphite flame retardant provided by the present invention can be used as a flame retardant. It can be used alone or mixed with other flame retardants and added to polymer materials to play a flame retardant and fireproof role.

[0050] The present invention also provides a flame retardant polymer material, comprising the above-mentioned organic hypophosphite flame retardant.

[0051] In the present invention, the organic hypophosphite flame retardant included in the flame-retardant polymer material may be one or more, without special restrictions; in one embodiment provided by the present invention, the organic hypophosphite flame retardant in the flame-retardant polymer material includes the organic hypophosphite flame retardant represented by formula (I) when n is 0 and the organic hypophosphite flame retardant represented by formula (I) when n is 1 to 3; the mass ratio of the organic hypophosphite flame retardant represented by formula (I) when n is 0 to the organic hypophosphite flame retardant represented by formula (I) when n is 1 to 3 is preferably 1: (5 to 15), more preferably 1: (7 to 12), more preferably 1: (8 to 10), and most preferably 1: 9.

[0052] In one embodiment provided by the present invention, the organic hypophosphite flame retardant in the flame-retardant polymer material includes the organic hypophosphite flame retardant represented by formula (I) when n is 0 and the organic hypophosphite flame retardant represented by formula (I) when n is 1 or 2; the mass ratio of the organic hypophosphite flame retardant represented by formula (I) when n is 0 to the organic hypophosphite flame retardant represented by formula (I) when n is 1 or 2 is preferably 1: (5 to 15), more preferably 1: (7 to 12), further preferably 1: (8 to 10), and most preferably 1: 9.

[0053] In one embodiment provided by the present invention, the organic hypophosphite flame retardant in the flame-retardant polymer material includes the organic hypophosphite flame retardant represented by formula (I) when n is 0 and the organic hypophosphite flame retardant represented by formula (I) when n is 1; the mass ratio of the organic hypophosphite flame retardant represented by formula (I) when n is 0 to the organic hypophosphite flame retardant represented by formula (I) when n is 1 or 2 is preferably 1: (5 to 15), more preferably 1: (7 to 12), further preferably 1: (8 to 10), and most preferably 1: 9.

[0054] In the present invention, the mass of the organophosphite flame retardant is preferably 3% to 40% of the mass of the flame-retardant polymer material; optionally, the mass of the organophosphite flame retardant is any value among 3%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35% and 40% of the mass of the flame-retardant polymer material, or a range of values ​​therebetween. Specifically, the amount of the organophosphite flame retardant having the structure of formula (I) used depends on the structure of the polymer material.

[0055] According to the present invention, the flame retardant polymer material preferably also includes a polymer material; the mass of the polymer material is preferably 60% to 97% of the mass of the flame retardant polymer material; the polymer material can be a polymer material of those skilled in the art without any special restrictions. In the present invention, it is preferably one or more of polyurethane, unsaturated polyester resin, epoxy resin, polyolefin, polystyrene olefin, polyamide, polyester, polyphenylene ether, polyvinyl chloride and polyacrylic acid, more preferably one or more of polyurethane, epoxy resin, unsaturated polyester resin and polyvinyl chloride, further preferably one or more of polyurethane, epoxy resin and unsaturated polyester resin.

[0056] According to the present invention, the flame retardant polymer material preferably also includes functional additives other than flame retardants; the mass of the functional additives is preferably 5% to 40% of the mass of the flame retardant polymer material; the functional additives are preferably one or more of a reinforcing agent, an anti-dripping agent, a stabilizer, a pigment, a carbonizing catalyst, a dispersant, a nucleating agent, an inorganic filler, an organic filler and an antioxidant; the inorganic filler is preferably one or more of silicon dioxide, mica, calcium carbonate, aluminum oxide, aluminum hydroxide, aluminum nitride, talc, calcium oxide, calcium silicate and silica.

[0057] According to the present invention, the flame-retardant polymer material preferably further includes other flame retardants; the other flame retardants are flame retardants other than the organic hypophosphite flame retardant represented by formula (I); the mass of the other flame retardants is preferably 0.5% to 20% of the mass of the flame-retardant polymer material; the other flame retardants are flame retardants that can be used in polymer materials that are well known to those skilled in the art, and there are no special restrictions. In the present invention, phosphorus-based flame retardants and / or nitrogen-based flame retardants are preferably selected from the group consisting of phosphates, phosphazenes, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivatives.

[0058] In a specific embodiment provided by the present invention, the flame retardant polymer material is preferably a flame retardant polyurethane material; the flame retardant polyurethane material includes an organic hypophosphite flame retardant represented by formula (I) and polyurethane; the mass of the organic hypophosphite flame retardant represented by formula (I) is preferably 5% to 35% of the mass of the flame retardant polyurethane material; optionally, the mass of the organic hypophosphite flame retardant represented by formula (I) is any value of 5%, 10%, 15%, 20%, 25%, 30%, 35% by weight of the mass of the flame retardant polyurethane material or a range value between any two of them; the mass of the polyurethane is preferably 65% ​​to 95% of the mass of the flame retardant polyurethane material; the flame retardant polyurethane material preferably also includes functional additives other than flame retardants; the functional additives are functional additives well known to those skilled in the art and are not particularly limited. In the present invention, they are preferably one or more of a reinforcing agent, an anti-dripping agent, a stabilizer, a pigment, a dye, a carbonizing catalyst, a dispersant, a nucleating agent, an inorganic filler, an organic filler and an antioxidant.

[0059] In order to further illustrate the present invention, an organic hypophosphite flame retardant, a preparation method thereof and a flame retardant polymer material provided by the present invention are described in detail below with reference to the examples.

[0060] The reagents used in the following examples are all commercially available.

[0061] raw material:

[0062] (1) Diethylphosphinic acid chloride (containing 98.5 wt% diethylphosphinic acid chloride and 1.5 wt% ethylbutylphosphinic acid chloride), Jiangsu Liside New Materials Co., Ltd.

[0063] (2) Benzyl alcohol, p-phenylenediol, m-phenylenediol, 3-phenyl-propanol, triethylamine, N,N-dimethyl-p-toluidine, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0064] (3) Polyurethane rigid foam polyether 6305, polyurethane rigid foam polyether 635, rigid foam silicone oil M88108, Nanjing Meiside Chemical Co., Ltd.;

[0065] (4) The polyurethane rigid foam catalyst is dimethylcyclohexylamine (PC-8), and the blowing agent is pentafluoropropane (HFC-245fa), polymeric MDI (PM200), triethyl phosphate (TEP), trichloroethyl phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), triphenyl phosphate (TPP), diethyl ethyl phosphate (DEEP), and diaminodiphenylmethane (DDM), all of which were purchased through commercial channels.

[0066] (5) Epoxy resin is E51, Nantong Xingchen Synthetic Materials Co., Ltd.

[0067] test:

[0068] (1) Acid value determination: The test was performed using KOH ethanol solution titration method.

[0069] (2) 1 H NMR test: The test was performed using a BRUKER AVANCE 400 instrument.

[0070] Example 1

[0071] 1.1 Dissolve 100 g of diethylphosphinoyl chloride in 300 mL of tetrahydrofuran to obtain solution A.

[0072] 1.2 Dissolve 50 g of phenylmethanol and 20 g of triethylamine catalyst in 200 mL of tetrahydrofuran to obtain solution B.

[0073] 1.3 At 65°C, slowly add Solution A to Solution B via a dropping funnel with stirring. Monitor the reaction progress using 31P NMR. Addition was complete within approximately 1 hour. After the addition was complete, continue stirring for 2 hours to terminate the reaction. Filter to remove the amine salt, remove the solvent by rotary evaporation, and filter the resulting triethylamine salt again. Vacuum distillation was performed to obtain an organic hypophosphite flame retardant with an 88% yield and an acid value of 3.7 mgKOH / g. The H NMR spectrum of the resulting product is shown in Figure 1.

[0074] Example 2

[0075] 2.1 Dissolve 100 g of diethylphosphinoyl chloride in 300 mL of toluene solvent to obtain solution A.

[0076] 2.2 Dissolve 50 g of phenylmethanol and 20 g of triethylamine catalyst in 150 mL of toluene to obtain solution B.

[0077] 2.3 At 100°C, slowly add Solution A to Solution B via a dropping funnel with stirring. Monitor the reaction progress using 31P NMR. Addition should be complete within approximately 30 minutes. After completion, continue stirring for 2 hours to terminate the reaction. Filter to remove the amine salt, remove the solvent by rotary evaporation, and filter the resulting triethylamine salt again. Distill under reduced pressure to obtain an organic hypophosphite flame retardant with a yield of 82%. The resulting hypophosphite flame retardant has an acid value of 7.6 mgKOH / g.

[0078] Example 3

[0079] 3.1 Dissolve 100 g of diethylphosphinoyl chloride in 200 mL of toluene solvent to obtain solution A.

[0080] 3.2 Dissolve 50 g of p-phenylenediol and 22 g of triethylamine catalyst in 150 mL of toluene to obtain solution B.

[0081] 3.3 At 105°C, solution A was slowly added to solution B via a dropping funnel with stirring. The reaction progress was monitored using 31P NMR. The addition was complete within approximately 1.5 hours. After the addition was complete, stirring was continued for 2 hours to terminate the reaction. The amine salt was filtered to remove the solvent, and the resulting triethylamine salt was filtered again. The filtrate was extracted with dichloromethane and dried to obtain an organic hypophosphite flame retardant with a yield of 77%. The acid value of the resulting hypophosphite flame retardant was 5.1 mgKOH / g. The H NMR spectrum of the resulting product is shown in Figure 2.

[0082] Example 4

[0083] 4.1 Dissolve 100 g of diethylphosphinoyl chloride in 200 mL of tetrahydrofuran solvent to obtain solution A.

[0084] 4.2 Dissolve 50 g of m-phenylenediol and 24 g of N,N-dimethyl-p-toluidine catalyst in 180 mL of tetrahydrofuran to obtain solution B.

[0085] 4.3 At 66°C, slowly add Solution A to Solution B via a dropping funnel with stirring. Monitor the reaction progress using 31P NMR. Addition should be complete within approximately 2 hours. After the addition is complete, continue stirring for 3 hours to terminate the reaction. Remove the amine salt by filtration, remove the solvent by rotary evaporation, and filter the resulting N,N-dimethyl-p-toluidine salt again. Extract the filtrate with dichloromethane to obtain an organic hypophosphite flame retardant in an 86% yield. The resulting hypophosphite flame retardant has an acid value of 3.6 mgKOH / g.

[0086] Example 5

[0087] 5.1 Dissolve 100 g of diethylphosphinoyl chloride in 220 mL of tetrahydrofuran solvent to obtain solution A.

[0088] 5.2 Dissolve 54 g of 3-phenyl-propanol and 21 g of N,N-dimethyl-p-toluidine catalyst in 180 mL of tetrahydrofuran to obtain solution B.

[0089] 5.3 At 66°C, slowly add Solution B to Solution A via a dropping funnel with stirring. Monitor the reaction progress using 31P NMR. Addition should be complete within approximately 1.2 hours. After the addition is complete, continue stirring for 3 hours to terminate the reaction. Filter to remove the amine salt, remove the solvent by rotary evaporation, and filter the resulting N,N-dimethyl-p-toluidine salt again. Distill under reduced pressure to obtain an organic hypophosphite flame retardant with a yield of 81%. The resulting hypophosphite flame retardant has an acid value of 11.2 mgKOH / g.

[0090] Example 6

[0091] 10 wt% of the hypophosphite flame retardant prepared in Example 1 was mixed with 90 wt% of the hypophosphite flame retardant prepared in Example 3 to obtain a mixture of the two flame retardants, with an acid value of 4.9 mgKOH / g.

[0092] Application of halogen-free flame retardants:

[0093] The hypophosphite flame retardant prepared in Examples 1 to 6 was applied to polyurethane, and the specific operation process was as follows:

[0094] Polyether 6305, polyether 635, rigid foam silicone oil M88108, catalyst PC-8, water, and blowing agent HFC-245fa were added to a beaker in a mass ratio of 70:30:2.0:4.0:2:25 and stirred at high speed for 10 seconds to produce a mixed polyether. The organic hypophosphite flame retardant prepared in the above example was then added. High-speed stirring was continued for 20 seconds to uniformly mix the components. Polymeric MDI was then added to the resulting mixture and stirred again for 10 seconds. After the mixture turned white, it was poured into a mold and allowed to foam freely. After the reaction was complete, it was oven-cured at 80°C for 4 hours to produce a highly efficient, environmentally friendly, flame-retardant polyurethane foam. The specific components and their proportions are shown in Table 1.

[0095] The epoxy resin and the organic hypophosphite flame retardant prepared in the embodiment were stirred at high speed for 20 seconds using a high-speed stirrer to mix evenly, and then the curing agent DDM was added to the resulting mixed system, stirred again for 10 seconds using a high-speed stirrer, and placed in an 80°C oven for aging for 4 hours to obtain a flame-retardant epoxy resin.

[0096] Table 1 Composition of polyurethane foam material and flame retardant epoxy resin

[0097] The main performance indicators of flame retardant polyurethane foam and flame retardant epoxy resin are as follows, and the results are shown in Table 2:

[0098] Dimensional stability: The obtained M1-M10 polyurethane foam was aged in a 70℃ oven for 48 hours and then placed at room temperature for three days. The length of the sample before and after aging was tested according to GB-T8811-2008.

[0099] Where L2 is the length of the sample after aging, and L1 is the length of the sample before aging.

[0100] Compression performance: The prepared M1-M10 flame retardant polyurethane foam was tested according to GB-T8813-2022 rigid foam compression performance test.

[0101] Oxygen index: For the prepared M1-M10 flame retardant polyurethane foam and M10-M13 flame retardant epoxy resin, the oxygen index is tested according to GB-T2406.2-2009.

[0102] Stability test: M1 to M10 flame-retardant polyurethane foams were aged in a 70°C oven for 48 hours. After being placed at room temperature for three days, the oxygen index was tested to examine changes in flame retardant stability.

[0103] The M11-M12 epoxy resins were aged in an oven at 85°C for 48 hours. After cooling, the color number changes were compared using the Pt-Co colorimetry method to investigate the stability changes.

[0104] Table 2 Performance test of halogen-free flame retardant polyurethane and flame retardant epoxy resin

[0105] As shown in Table 2, the flame-retardant polymer material prepared by using the organic hypophosphite flame retardant provided by the present invention as a polymer flame retardant has good flame retardant stability and good mechanical properties.

[0106] The preferred embodiments of the present invention disclosed above are merely intended to help illustrate the present invention, but the present invention is not limited thereto. Those skilled in the art will appreciate that, within the scope of the technical concept of the present invention, the technical solutions of the present invention may be modified, or some of the technical features may be combined in any other manner. Such modifications or combinations do not deviate from the essence of the corresponding technical solutions from the spirit and scope of the various technical solutions of the present invention, and should be regarded as the contents disclosed by the present invention and fall within the scope of protection of the present invention.

Claims

1. An organic hypophosphite flame retardant, characterized in that As shown in formula (I): Wherein, R1 and R2 are each independently selected from a C1 to C6 alkyl group; R3 is selected from C1 to C4 alkylene; n is the number of substituents, and is an integer selected from 0 to 3.

2. The organic hypophosphite flame retardant according to claim 1, characterized in that n is 1 or 2.

3. The organic hypophosphite flame retardant according to claim 1, wherein the acid value is less than or equal to 50 mgKOH / g.

4. The organic hypophosphite flame retardant according to claim 1, characterized in that As shown in formula (I-1) to formula (I-8):

5. A method for preparing an organic hypophosphite flame retardant, characterized in that: The following steps are involved: S1) mixing a dialkylphosphinate halide represented by formula (II) with a first organic solvent to obtain a solution A; Mixing an aryl alcohol represented by formula (III), an amine catalyst and a second organic solvent to obtain a solution B; S2) mixing solution A with solution B to react to obtain an organic hypophosphite flame retardant represented by formula (I); Wherein, R1 and R2 are each independently selected from a C1 to C6 alkyl group; R3 is selected from C1 to C4 alkylene; X is a halogen atom; n is the number of substituents, and is an integer selected from 0 to 3.

6. A flame retardant polymer material, characterized in that: The invention comprises the organic hypophosphite flame retardant according to any one of claims 1 to 4 or the organic hypophosphite flame retardant prepared by the preparation method according to claim 5 and a polymer material.

7. The flame retardant polymer material according to claim 6, characterized in that: The mass of the organic hypophosphite flame retardant is 3% to 40% of the mass of the flame retardant polymer material.

8. The flame retardant polymer material according to claim 6, characterized in that: It also includes other flame retardants; the mass of the other flame retardants is 0.5% to 20% of the mass of the flame retardant polymer material.

9. The flame retardant polymer material according to claim 8, characterized in that: The other flame retardants are selected from phosphorus-based flame retardants and / or nitrogen-based flame retardants; the phosphorus-based flame retardants are selected from one or more of phosphates, phosphazenes, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivatives.

10. The flame retardant polymer material according to any one of claims 6 to 9, characterized in that: The polymer material is selected from one or more of polyurethane, unsaturated polyester resin, epoxy resin, polyolefin, polystyrene olefin, polyamide, polyester, polyphenylene ether, polyvinyl chloride and polyacrylic acid.

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