Organic phosphonic acid polymer flame retardant as well as preparation method and application thereof

Abstract

The organic phosphonic acid polymer flame retardant is prepared by taking organic phosphinic acid containing alkylene as an initiator, and the organic phosphonic acid polymer flame retardant is high in phosphine content and convenient to synthesize. The synthesized organic phosphonic acid polymer flame retardant can provide better flame retardant property under the condition of lower additive amount, and as the organic phosphonic acid polymer flame retardant is a polymer, has large molecular weight and does not contain metal ions, a better bicontinuous phase is formed in resin, so that the resin has higher retention rate of mechanical property and electrical property, and the flame retardant has better flame retardant property. The flame retardant can be widely applied to the technical field of flame retardants.

Description

Technical Field

[0001] The present invention relates to the technical field of flame retardants, and particularly relates to an organophosphonic acid polymer flame retardant, a preparation method thereof, and an application thereof. Background Art

[0002] Organic polymers are a type of material with a relatively large consumption in the current materials market. Organic compounds are generally divided into rubbers with relatively low hardness and large elongation, plastics with relatively high hardness and large strength, as well as materials such as synthetic fibers and coatings. However, polymer molecules contain a large amount of C, H, O, and N elements, belonging to flammable materials, and will continue to burn when on fire, posing a great risk to people's lives and property safety. Especially for polymers related to electricity such as electronic appliances, wires, and cables, once they burn, the fire will spread rapidly. At the same time, with the strictness and halogen-free requirements of flame retardant standards in various countries and regions, such as the REACH regulation, the California Proposition 65 Act in the United States, and the sony flame retardant standard, higher requirements are put forward for the performance of flame retardants.

[0003] Most of the existing flame retardants are powder-added flame retardants. The compatibility of these powders with the resin matrix is poor, which easily destroys the microstructure of the resin, affects the crystallization performance of crystalline resins, and at the same time fills the amorphous region of the polymer to destroy the flexibility of the polymer, resulting in a relatively large decrease in the mechanical properties of the resin. Even when the addition amount is only about 20%, it will greatly reduce the toughness and melt viscosity of the resin, and will also greatly affect its mechanical properties for the resin. Summary of the Invention

[0004] The purpose of the present invention is to solve the above technical deficiencies and provide an organophosphonic acid polymer flame retardant, a preparation method thereof, and an application thereof.

[0005] To this end, the present invention provides a preparation method of an organophosphonic acid polymer flame retardant, comprising the following steps:

[0006] (1) Add an organic phosphinic acid containing an olefin group to an acyl halide reagent at -30°C - 60°C, and then raise the temperature to 10°C above the boiling point of the acyl halide reagent at a heating rate of 0.5 - 10°C / min and reflux, or directly set the device to 10°C higher than the boiling point of the acyl halide reagent and allow it to heat up naturally until reflux occurs; after the reflux ends, distill out the excess acyl halide reagent to obtain a phosphonyl halide containing an olefin group;

[0007] The reaction formula is:

[0008]

[0009] (2) Add an excessive amount of a nucleophilic reagent or an electrophilic reagent and an appropriate amount of a solvent to the phosphonyl halide containing an alkenyl group obtained in step (1) at -30°C to 60°C, then increase the temperature to 10°C above the boiling point of the added solvent at a heating rate of 0.5 - 10°C / min and reflux, or directly set the apparatus to 10°C higher than the boiling point of the added nucleophilic reagent or electrophilic reagent and let it warm up naturally until reflux occurs; after the reflux ends, distill off the excess solvent and nucleophilic reagent or electrophilic reagent to obtain an organophosphorus compound containing an alkenyl group;

[0010] The reaction formula is:

[0011]

[0012] Or

[0013]

[0014] (3) Put the organophosphorus compound containing an alkenyl group obtained in step (2) into a four-necked flask, add an appropriate amount of a solvent and an initiator, and polymerize at the initiation temperature of the initiator to obtain a polymeric organophosphonate or a polymeric organophosphonamide.

[0015] The reaction formula is:

[0016]

[0017] Or

[0018]

[0019] Preferably, the organic phosphinic acid containing an olefin group in step (1) is selected from vinylmethylphosphinic acid, vinylethylphosphinic acid, bis(vinyl)phosphinic acid, vinylpropylphosphinic acid, vinylbutylphosphinic acid, vinylpentylphosphinic acid, vinylhexylphosphinic acid, vinyloctylphosphinic acid, vinylstearylphosphinic acid, vinylcyclobutylphosphinic acid, vinylcyclopentylphosphinic acid, vinylcyclohexylphosphinic acid, vinylphenylphosphinic acid, vinylbenzylphosphinic acid, vinylphenethylphosphinic acid, vinylnaphthylphosphinic acid, vinylstearylphosphinic acid, allylmethylphosphinic acid, allylethylphosphinic acid, bis(allyl)phosphinic acid, allylpropylphosphinic acid, allylbutylphosphinic acid, allylpentylphosphinic acid, allylhexylphosphinic acid, allyloctylphosphinic acid, allylstearylphosphinic acid, allylcyclobutylphosphinic acid, allylcyclopentylphosphinic acid, allylcyclohexylphosphinic acid, allylphenylphosphinic acid, allylbenzylphosphinic acid, allylphenethylphosphinic acid, allylnaphthylphosphinic acid, allylstearylphosphinic acid, butenylmethylphosphinic acid, butenylethylphosphinic acid, bis(butenyl)phosphinic acid, butenylpropylphosphinic acid, butenylbutylphosphinic acid, butenylpentylphosphinic acid, butenylhexylphosphinic acid, butenyloctylphosphinic acid, butenylstearylphosphinic acid, butenylcyclobutylphosphinic acid, butenylcyclopentylphosphinic acid, butenylcyclohexylphosphinic acid, butenylphenylphosphinic acid, butenylbenzylphosphinic acid, butenylphenethylphosphinic acid, butenylnaphthylphosphinic acid, butenylstearylphosphinic acid, pentenylmethylphosphinic acid, pentenylethylphosphinic acid, bis(pentenyl)phosphinic acid, pentenylpropylphosphinic acid, pentenylbutylphosphinic acid, pentenylpentylphosphinic acid, pentenylhexylphosphinic acid, pentenyloctylphosphinic acid, pentenylstearylphosphinic acid, pentenylcyclobutylphosphinic acid, pentenylcyclopentylphosphinic acid, pentenylcyclohexylphosphinic acid, pentenylphenylphosphinic acid, pentenylbenzylphosphinic acid, pentenylphenethylphosphinic acid, pentenylnaphthylphosphinic acid, pentenylstearylphosphinic acid, hexenylmethylphosphinic acid, hexenylethylphosphinic acid, bis(hexenyl)phosphinic acid, hexenylpropylphosphinic acid, hexenylbutylphosphinic acid, hexenylpentylphosphinic acid, hexenylhexylphosphinic acid, hexenyloctylphosphinic acid, hexenylstearylphosphinic acid, hexenylcyclobutylphosphinic acid, hexenylcyclopentylphosphinic acid, hexenylcyclohexylphosphinic acid, hexenylphenylphosphinic acid, hexenylbenzylphosphinic acid, hexenylphenethylphosphinic acid, hexenylnaphthylphosphinic acid, hexenylstearylphosphinic acid, octenylmethylphosphinic acid, octenylethylphosphinic acid, bis(octenyl)phosphinic acid, octenylpropylphosphinic acid, octenylbutylphosphinic acid, octenylpentylphosphinic acid, octenylhexylphosphinic acid, octenyloctylphosphinic acid, octenylstearylphosphinic acid, octenylcyclobutylphosphinic acid, octenylcyclopentylphosphinic acid, octenylcyclohexylphosphinic acid, octenylphenylphosphinic acid, octenylbenzylphosphinic acid, octenylphenethylphosphinic acid, octenylnaphthylphosphinic acid,At least one of octenyl octadecylphosphinic acid, octenyl methylphosphinic acid, octenyl ethylphosphinic acid, bis(octenyl)phosphinic acid, cyclobutenyl methylphosphinic acid, cyclobutenyl ethylphosphinic acid, cyclobutenyl propylphosphinic acid, cyclobutenyl butylphosphinic acid, cyclobutenyl pentylphosphinic acid, cyclobutenyl hexylphosphinic acid, cyclobutenyl octylphosphinic acid, cyclobutenyl octadecylphosphinic acid, cyclobutenyl cyclobutylphosphinic acid, cyclobutenyl cyclopentylphosphinic acid, cyclobutenyl cyclohexylphosphinic acid, cyclobutenyl phenylphosphinic acid, cyclobutenyl benzylphosphinic acid, cyclobutenyl phenethylphosphinic acid, cyclobutenyl naphthylphosphinic acid, cyclobutenyl octadecylphosphinic acid, cyclohexenyl methylphosphinic acid, cyclohexenyl ethylphosphinic acid, cyclohexenyl propylphosphinic acid, cyclohexenyl butylphosphinic acid, cyclohexenyl pentylphosphinic acid, cyclohexenyl hexylphosphinic acid, cyclohexenyl octylphosphinic acid, cyclohexenyl octadecylphosphinic acid, cyclohexenyl cyclobutylphosphinic acid, cyclohexenyl cyclopentylphosphinic acid, cyclohexenyl cyclohexylphosphinic acid, cyclohexenyl phenylphosphinic acid, cyclohexenyl benzylphosphinic acid, cyclohexenyl phenethylphosphinic acid, cyclohexenyl naphthylphosphinic acid, cyclohexenyl octadecylphosphinic acid, styryl methylphosphinic acid, styryl ethylphosphinic acid, styryl propylphosphinic acid, styryl butylphosphinic acid, styryl pentylphosphinic acid, styryl hexylphosphinic acid, styryl octylphosphinic acid, styryl octadecylphosphinic acid, styryl cyclobutylphosphinic acid, styryl cyclopentylphosphinic acid, styryl cyclohexylphosphinic acid, styryl phenylphosphinic acid, styryl benzylphosphinic acid, styryl phenethylphosphinic acid, styryl naphthylphosphinic acid, styryl octadecylphosphinic acid.

[0020] Preferably, the acyl halide reagent in step (1) is any one of thionyl chloride, phosgene, oxalyl chloride, thionyl bromide, oxalyl bromide, and NBS.

[0021] Preferably, the nucleophile or electrophile is any one of C1-C18 alcohols or amines or C1-C10 amino alcohols.

[0022] Preferably, the nucleophile or electrophile is any one of methanol, ethanol, propanol, propanol, butanol, pentanol, hexanol, octanol, octadecyl alcohol, phenol, benzyl alcohol, phenethyl alcohol, naphthol, naphthyl alcohol, naphthyl ethanol, methylamine, ethylamine, propylamine, butylamine, pentylamine, cyclohexylamine, aminocyclohexane, aniline, diphenylamine, biphenyl diamine, naphthylmethylamine, ethanolamine, dimethylamine.

[0023] Preferably, the solvent is at least one of water, ethyl acetate, butyl acetate, toluene, xylene, DMF, DMSO, DMAC, methyl ethyl ketone, tetrahydrofuran, chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, vinylidene chloride, perchloroethane, 1,1,2,2-tetrafluoroethane, vinylidene fluoride, 1,2-difluoroethane, naphthalene, methanol, ethanol, propanol, isopropanol, butanol, and isobutanol.

[0024] Preferably, the initiator is any one of a radical initiator and an anionic initiator.

[0025] Preferably, the initiator is any one of hydrogen peroxide, hydrogen peroxide-ferrous (II) sulfate, hydrogen peroxide-sulfite, benzoyl peroxide, perbenzoic acid, sodium percarbonate, potassium percarbonate, sodium persulfate, potassium persulfate, ammonium persulfate, azobisisobutyronitrile, sodium naphthalene, butyllithium, and butylaluminum.

[0026] Preferably, in step (1), the reflux reaction time is 0.1 - 24 h; in step (2), the dropping time of the nucleophilic reagent or electrophilic reagent and the solvent is 0.1 - 24 h, and the reflux reaction time is 0.1 - 24 h; in step (3), the initiator initiation temperature is -10 - 150 °C, and the polymerization reaction time is 0.2 - 24 h.

[0027] An organophosphonic acid polymer flame retardant is prepared by the above method.

[0028] Preferably, the organophosphonate containing an olefin structure has the following structure:

[0029]

[0030] Or

[0031]

[0032] In the structural formula I or II, R1 is selected from any one of a C1 - C18 hydrocarbon group or hydrogen; R2 is selected from any one of a C1 - C18 alkylene group or R2 does not exist, that is, a carbon atom is directly connected to phosphorus; R3 is selected from any one of a C1 - C18 hydrocarbon group; R4 is selected from any one of a C1 - C18 hydrocarbon group or a substituted hydrocarbon group; n is an integer not less than 3; the molecular weight of the polymer is between 500 and 500,000.

[0033] Preferably, R1 and R3 are selected from at least one of methyl, ethyl, propyl, butyl, pentyl, naphthyl, phenyl, phenethyl, cyclohexyl, cyclobutyl, cyclopentyl, octyl, octadecyl; when R2 is absent, the phosphine is directly connected to the 2nd carbon element, and when R2 is present, R2 is selected from any one of methylene, ethylene, propylene, butylene; R4 is selected from any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, octadecyl, glycidyl, epoxybutyl, epoxyvalyl, allyl, butenyl.

[0034] The present invention provides an organophosphonic acid polymer flame retardant, its preparation method and application, and has the following beneficial effects:

[0035] The organophosphonic acid polymer flame retardant synthesized by the present invention has a high phosphorus content and is convenient to synthesize. The polymeric organophosphorus flame retardant not only has a flame retardant effect on the resin, but also can provide a certain toughening effect, and also has anti-precipitation properties and can pass the double 85@176h test. At the same time, compared with the traditional aluminum diethylphosphinate flame retardant, it has higher flame retardancy under the same addition amount. And because the organophosphonic acid polymer itself is a polymer with a large molecular weight and no metal ions, it forms a good double continuous phase in the resin, so that the resin simultaneously has a higher retention rate of mechanical properties and electrical properties, and thus has a lower impact on the mechanical properties of the material after addition than the traditional additive flame retardant.

[0036] Therefore, compared with the existing additive flame retardants, the traditional additive halogen-free flame retardants do not have a melting point, and the particles are rigid particles, which cause great damage to the mechanical properties of the polymer. However, the polymeric organophosphonic acid compound flame retardant synthesized by the present invention can reduce the damage of the flame retardant to the mechanical properties of the polymer and improve the flame retardancy. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is the infrared spectrum of the organophosphonic acid polymer flame retardant prepared by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0038] The present invention will be further described below in conjunction with the drawings and specific embodiments to help understand the content of the present invention. The methods used in the present invention are all conventional methods unless otherwise specified; the raw materials and devices used are all conventional commercially available products unless otherwise specified.

[0039] Example 1

[0040] Add 6 mol of thionyl chloride into a four-necked flask, and set up a reflux device, a tail gas collection device and a buffer device. Then cool the thionyl chloride to -30 °C, and while stirring, dropwise add 1 mol of vinylmethylphosphinic acid over 0.1 h. Then heat it up to 88 °C at a rate of 10 °C / min and reflux for 24 h. After the reflux is completed, distill out the excess thionyl chloride, and then add an excess of methanol and reflux to react to obtain the intermediate methyl vinylmethylphosphinate; add 500 ml of naphthalene to the system, and fully displace it with nitrogen so that the system is under a nitrogen atmosphere, and then add a solution containing 10 -1 mol of sodium naphthalene-naphthalene solution, and raise the temperature to 60 °C and react for 0.2 h, and then quench the sodium naphthalene with ethanol to obtain poly(methyl vinylmethylphosphinate).

[0041] Example 2

[0042] Add 6 mol of thionyl chloride into a four-necked flask, and set up a reflux device, a tail gas collection device and a buffer device. Then cool the thionyl chloride to -30 °C, and while stirring, dropwise add 1 mol of vinyl ethylphosphinic acid over 0.1 h. Then heat it up to 88 °C at a rate of 0.5 °C / min and reflux for 24 h. After the reflux is completed, distill out the excess thionyl chloride, and then add an excess of methanol and reflux to react to obtain the intermediate ethyl vinyl ethylphosphinate; add 500 ml of deionized water to the system, and then add 10 -2 mol of ammonium persulfate, and raise the temperature to 60 °C and react for 0.2 h, and then raise the temperature to 100 °C and reflux for 1 h to obtain poly(ethyl vinyl ethylphosphinate).

[0043] Example 3

[0044] Add 6 mol of thionyl chloride into a four-necked flask, and set up a reflux device, a tail gas collection device and a buffer device. Then cool the thionyl chloride to -30 °C, and while stirring, dropwise add 1 mol of vinylpropylphosphinic acid over 0.1 h. Then heat it up to 88 °C at a rate of 0.2 °C / min and reflux for 24 h. After the reflux is completed, distill out the excess thionyl chloride, and then add an excess of ethanol and reflux for 12 h to obtain the intermediate ethyl vinylpropylphosphinate; add 500 ml of naphthalene to the system, and fully displace it with nitrogen so that the system is under a nitrogen atmosphere, and then add a solution containing 10 -2 mol of sodium naphthalene-naphthalene solution, and raise the temperature to 60 °C and react for 2 h, and then quench the sodium naphthalene with ethanol to obtain poly(ethyl vinylpropylphosphinate).

[0045] Example 4

[0046] Add 8 mol of thionyl chloride into a four-necked flask, and set up a reflux device, a tail gas collection device and a buffer device. Then cool the thionyl chloride to -30 °C, and while stirring, dropwise add 1 mol of vinylcyclohexylphosphinic acid over 0.8 h. Then heat it up to 88 °C at a rate of 5 °C / min and reflux for 24 h. After the reflux is completed, distill out the excess thionyl chloride, then add an excess of propanol and reflux for 1 h to obtain the intermediate vinylcyclohexylpropyl phosphinate; add 500 ml of naphthalene to the system, and fully displace it with nitrogen so that the system is under a nitrogen atmosphere, and then add a naphthalene-sodium naphthalene solution containing 10 -4 mol, and raise the temperature to 60 °C and react for 24 h. Then quench the sodium naphthalene with ethanol to obtain poly(vinylcyclohexylpropyl phosphinate).

[0047] Example 5

[0048] Add 8 mol of thionyl bromide into a four-necked flask, and set up a reflux device, a tail gas collection device and a buffer device. Then cool the thionyl bromide to 20 °C, and while stirring, dropwise add 1 mol of allylbutylphosphinic acid over 10 h. After the addition is completed, set the temperature to 158 °C. When the temperature reaches 158 °C, keep it warm and reflux for 24 h. After the reflux is completed, distill out the excess thionyl bromide, then add an excess of propanol and reflux for 6 h to obtain the intermediate allylbutylpropyl phosphinate; add 500 ml of naphthalene to the system, and fully displace it with nitrogen so that the system is under a nitrogen atmosphere, and then add a naphthalene-sodium naphthalene solution containing 10 -3 mol, and raise the temperature to 60 °C and react for 14 h. Then quench the sodium naphthalene with ethanol to obtain poly(allylbutylpropyl phosphinate).

[0049] Example 6

[0050] Add 8 mol of oxalyl chloride into a four-necked flask, and set up a reflux device, a tail gas collection device and a buffer device. Then keep the oxalyl chloride at 40 °C, and while stirring, dropwise add 1 mol of butenylmethylphosphinic acid over 24 h. After the addition is completed, set the temperature to 75 °C. When the temperature reaches 75 °C, keep it warm and reflux for 12 h. After the reflux is completed, distill out the excess oxalyl chloride, then add an excess of methanol and reflux for 4 h to obtain the intermediate butenylmethyl methyl phosphinate; add 500 ml of naphthalene to the system, and fully displace it with nitrogen so that the system is under a nitrogen atmosphere, and then add a naphthalene-sodium naphthalene solution containing 5×10 -2 mol, and raise the temperature to 60 °C and react for 6 h. Then quench the sodium naphthalene with ethanol to obtain poly(butenylmethyl methyl phosphinate).

[0051] Example 7

[0052] Add 8 mol of oxalyl chloride into a four-necked flask, and set up a reflux device, a tail gas collection device and a buffer device. Then keep the oxalyl chloride at 40 °C, and while stirring, slowly add 1 mol of butenylmethylphosphinic acid dropwise over 24 h. After the addition, set the temperature to 75 °C. When the temperature reaches 75 °C, keep the temperature and reflux for 12 h. After the reflux is completed, distill out the excess oxalyl chloride, then add an excess of methanol and reflux for 4 h to obtain the intermediate methyl butenylmethylphosphinate. Add 500 ml of deionized water to the system, and then add 5×10 -2 mol of ammonium persulfate in batches, and raise the temperature to 60 °C and react for 24 h, then raise the temperature to 100 °C and reflux for 4 h to obtain poly(methyl butenylmethylphosphinate).

[0053] Example 8

[0054] Add 8 mol of oxalyl chloride into a four-necked flask, and set up a reflux device, a tail gas collection device and a buffer device. Then keep the oxalyl chloride at 40 °C, and while stirring, slowly add 1 mol of vinyl ethylphosphinic acid dropwise over 12 h. After the addition, set the temperature to 75 °C. When the temperature reaches 75 °C, keep the temperature and reflux for 24 h. After the reflux is completed, distill out the excess oxalyl chloride, then add an excess of methanol and reflux for 8 h to obtain the intermediate methyl vinyl ethylphosphinate. Add 500 ml of deionized water to the system, and then add 5×10 -2 mol of ammonium persulfate in batches, and raise the temperature to 60 °C and react for 24 h, then raise the temperature to 100 °C and reflux for 4 h to obtain poly(methyl vinyl ethylphosphinate).

[0055] Example 9

[0056] Add 8 mol of oxalyl chloride into a four-necked flask, and set up a reflux device, a tail gas collection device and a buffer device. Then keep the oxalyl chloride at 40 °C, and while stirring, slowly add 1 mol of vinyl ethylphosphinic acid dropwise over 12 h. After the addition, set the temperature to 75 °C. When the temperature reaches 75 °C, keep the temperature and reflux for 24 h. After the reflux is completed, distill out the excess oxalyl chloride, then add an excess of ethanolamine and reflux for 8 h to obtain the intermediate N-(2-hydroxyethyl) vinyl ethylphosphonamide. Add 500 ml of deionized water to the system, and then add 5×10 -2 mol of ammonium persulfate in batches, and raise the temperature to 60 °C and react for 24 h, then raise the temperature to 100 °C and reflux for 4 h to obtain poly(N-(2-hydroxyethyl) vinyl ethylphosphonamide).

[0057] Example 10

[0058] Add 8 mol of phosgene into a four-necked flask, and set up a reflux device, a tail gas collection device and a buffer device. Then keep the phosgene at -20 °C, and while stirring, dropwise add 1 mol of vinyl ethylphosphinic acid over 12 h. After the addition is completed, set the temperature to 55 °C. When the temperature reaches 55 °C, keep it warm and reflux for 24 h. After the reflux is completed, distill out the excess phosgene, then add an excess of dimethylamine and reflux for 8 h to obtain the intermediate vinyl ethylphosphonic acid dimethylamide. Add 500 ml of deionized water to the system, and then add 5×10 -2 mol of azobisisobutyronitrile in batches, raise the temperature to 60 °C and react for 24 h, and then raise the temperature to 100 °C and reflux for 4 h to obtain polyvinyl ethylphosphonic acid dimethylamide.

[0059] Example 11 group

[0060] Take the polyvinyl methylphosphinic acid methyl ester prepared in Example 1, add 15% in a 30% GF-reinforced PBT system and carry out melt blending and extrusion granulation to obtain reinforced flame-retardant PBT. Then injection mold to obtain standard specimens and test their mechanical properties and flame retardancy, as shown in Table 1;

[0061] Example 12 group

[0062] Take the polyvinyl methylphosphinic acid methyl ester prepared in Example 1, add 15% in a 30% GF-reinforced PET system and carry out melt blending and extrusion granulation to obtain reinforced flame-retardant PET. Then injection mold to obtain standard specimens and test their mechanical properties and flame retardancy, as shown in Table 1;

[0063] Example 13 group

[0064] Take the polyvinyl propylphosphinic acid propyl ester prepared in Example 3, add 15% in a 30% GF-reinforced PA66 system and carry out melt blending and extrusion granulation to obtain reinforced flame-retardant PA66. Then injection mold to obtain standard specimens and test their mechanical properties and flame retardancy, as shown in Table 1;

[0065] Example 14 group

[0066] Take the polyvinyl propylphosphinic acid propyl ester prepared in Example 3, add 15% in a 30% GF-reinforced PA6 system and carry out melt blending and extrusion granulation to obtain reinforced flame-retardant PA6. Then injection mold to obtain standard specimens and test their mechanical properties and flame retardancy, as shown in Table 1;

[0067] Example 15 group

[0068] Take the polyvinyl propylphosphinic acid propyl ester prepared in Example 3, add 8% in a PA6 system and carry out melt blending and extrusion granulation to obtain flame-retardant PA6. Then injection mold to obtain standard specimens and test their mechanical properties and flame retardancy, as shown in Table 1;

[0069] Control Example 1 Group

[0070] 15% aluminum diethylphosphinate was added to the 30% GF-reinforced PBT system and melt-blended and pelletized to obtain flame-retardant PBT. Then, standard specimens were injection-molded to test their mechanical and flame-retardant properties, as shown in Table 1;

[0071] Control Example 2 Group

[0072] 15% aluminum diethylphosphinate was added to the 30% GF-reinforced PET system and melt-blended and pelletized to obtain flame-retardant PET. Then, standard specimens were injection-molded to test their mechanical and flame-retardant properties, as shown in Table 1;

[0073] Control Example 3 Group

[0074] 15% aluminum diethylphosphinate was added to the 30% GF-reinforced PA66 system and melt-blended and pelletized to obtain flame-retardant PA66. Then, standard specimens were injection-molded to test their mechanical and flame-retardant properties, as shown in Table 1;

[0075] The experimental performance comparisons are as follows:

[0076] Table 1

[0077]

[0078] Through Figure 1 Examples 11-15 groups and Control Examples 1-3 groups, it can be seen that the polymeric organophosphorus flame retardant can not only provide flame retardancy to the resin, but also provide a certain toughening effect, and also has anti-bleeding properties and can pass the double 85@176h test. At the same time, compared with the traditional aluminum diethylphosphinate flame retardant, it has higher flame retardancy at the same addition amount. Since the organophosphonic acid polymer itself is a polymer with a large molecular weight and no metal ions, it forms a better double continuous phase in the resin, enabling the resin to have higher retention rates of mechanical and electrical properties. Therefore, the addition has a lower impact on the mechanical properties of the material than traditional additive flame retardants.

[0079] In summary, the organophosphonic acid polymer flame retardant synthesized in the present invention not only has a high phosphorus content and is easy to synthesize, but also has no melting point compared with traditional additive halogen-free flame retardants, and the particles are rigid particles, which do not significantly damage the mechanical properties of the polymer. The polymeric organophosphonic acid compound flame retardant synthesized in the present invention can reduce the damage of the flame retardant to the mechanical properties of the polymer and improve the flame retardancy.

[0080] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. An organic phosphonic acid polymer flame retardant, characterized in that: The organic phosphonic acid polymer flame retardant has the following structure: or In the structural formula I or II, R1 is selected from any one of C1-C18 hydrocarbon groups or hydrogen; R2 is selected from any one of C1-C18 alkylene groups or R2 does not exist, that is, the carbon atom is directly connected to the phosphine; R3 is selected from any one of C1-C18 hydrocarbon groups; R4 is selected from any one of C1-C18 hydrocarbon groups or substituted hydrocarbon groups; n is an integer not less than 3.

2. The organic phosphonic acid polymer flame retardant according to claim 1, characterized in that: The molecular weight of the organic phosphonic acid polymer flame retardant is between 500 and 500,000.

3. A method for preparing an organic phosphonic acid polymer flame retardant, characterized in that: The following steps are involved: (1) adding an organic phosphinic acid containing an olefin group to an acyl halide reagent at a temperature of -30°C to 60°C, then raising the temperature to 10°C above the boiling point of the acyl halide reagent at a heating rate of 0.5°C to 10°C / min and refluxing; after the reflux is completed, distilling off the excess acyl halide reagent to obtain a phosphonic acid halide containing an olefin group; (2) adding an excess of a nucleophilic agent or an electrophilic agent and an appropriate amount of a solvent to the phosphonyl halide containing an olefin group obtained in step (1) at a temperature of -30°C to 60°C, then raising the temperature to 10°C above the boiling point of the solvent at a heating rate of 0.5°C to 10°C / min and refluxing; after the reflux is completed, distilling off the excess solvent and the nucleophilic agent or the electrophilic agent to obtain an organic phosphine compound containing an olefin group; (3) placing the organic phosphine compound containing an olefin group obtained by the reaction in step (2) into a four-necked flask, adding an appropriate amount of solvent and initiator, and polymerizing at the initiation temperature of the initiator to obtain a polymerized organic phosphonate or a polymerized organic phosphonic acid amide.

4. The method for preparing an organic phosphonic acid polymer flame retardant according to claim 3, characterized in that: The acyl halide reagent in step (1) is any one of thionyl chloride, phosgene, oxalyl chloride, thionyl bromide or oxalyl bromide and NBS.

5. The method for preparing an organic phosphonic acid polymer flame retardant according to claim 3, characterized in that: The nucleophile or electrophile is any one of a C1-C18 alcohol or amine or a C1-C10 alcohol amine.

6. The method for preparing an organic phosphonic acid polymer flame retardant according to claim 3, characterized in that: The solvent is at least one of water, ethyl acetate, butyl acetate, toluene, xylene, DMF, DMSO, DMAC, butanone, tetrahydrofuran, chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, ethylene dichloride, perchloroethane, 1,1,2,2-tetrafluoroethane, ethylene difluoride, 1,2-difluoroethane, naphthalene, methanol, ethanol, propanol, isopropanol, butanol, and isobutanol.

7. The method for preparing an organic phosphonic acid polymer flame retardant according to claim 3, characterized in that: The initiator is any one of a free radical initiator and an anion initiator.

8. The method for preparing an organic phosphonic acid polymer flame retardant according to claim 3, characterized in that: In step (1), the reflux reaction time is 0.1-24h; in step (2), the nucleophilic reagent or electrophilic reagent and the solvent are added dropwise for 0.1-24h, and the reflux reaction time is 0.1-24h; in step (3), the initiation temperature of the initiator is -10-150°C, and the polymerization reaction time is 0.2-24h.

9. An application of an organic phosphonic acid polymer flame retardant, characterized in that: The organic phosphonic acid polymer flame retardant described in any one of claims 1 to 9 can be used alone or in combination with a phosphine-based flame retardant, a phosphine-nitrogen-based flame retardant, or a nitrogen-based flame retardant to improve the flame retardant properties of the polymer.

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