Dialkylphosphinate hybrid salts, their preparation method and use

Abstract

The present invention discloses a dialkylphosphinic acid hybrid salt, a method for preparing the same, and uses thereof. The dialkylphosphinic acid hybrid salt is at least one selected from compounds having a chemical formula represented by formula (I). The dialkylphosphinic acid hybrid salt having the composition of formula (I) provided by the present invention has a small addition amount, high flame retardancy efficiency for various polymer materials, good thermal stability, overcomes the drawback that the flame retardancy efficiency of diethylphosphinate for polymer materials is low, and at the same time overcomes the drawbacks that the long-chain dialkylphosphinate has low thermal stability and a large amount of smoke during combustion. Therefore, it can be widely used for flame retardancy of polymer materials that require high-temperature processing.

Description

Technical Field

[0001] The present invention relates to a dialkylphosphinic acid hybrid salt, a method for preparing the same, and use thereof, and particularly belongs to the field of preparing flame-retardant polymer materials.

Background Art

[0002] Dialkylphosphinate salts, especially aluminum diethylphosphinate, are widely used as halogen-free flame retardants for polymer materials. However, conventional dialkylphosphinate salts have limited flame-retardant efficiency for glass fiber reinforced polymer materials and need to be used together with synergists. US Patents US6207736, US6255371, US6547992, etc. disclose that dialkylphosphinate salts and inorganic compounds such as ammonium polyphosphate, melamine polyphosphate, and / or zinc stannate synergistically provide flame-retardant glass fiber reinforced polyamides and polyesters. However, the dosage of the flame retardant is large, the thermal stability of ammonium polyphosphate is not high, and melamine polyphosphate is easy to migrate.

[0003] US Patent US7420007 discloses aluminum diethylphosphinate containing 6% or less of a telomer phosphinate salt, i.e., a long-chain dialkylphosphinate salt. Chinese Patent CN104072537B discloses a method for removing long-chain dialkylphosphinate salts in the preparation process of diethylphosphinate salts. All of these patents emphasize avoiding the generation and use of long-chain dialkylphosphinate salts with high content and low thermal stability. In actual use, when using a long-chain dialkylphosphinate salt, such as aluminum dibutylphosphinate, to flame-retard glass fiber reinforced polyamide, there is a lot of smoke, which is disadvantageous for safe escape. A flame retardant with high flame-retardant effect and less smoke generation during combustion has always been the goal pursued by the industry.

[0004] Remarkably, hybrid salts consisting of relatively high concentrations of long-chain dialkylphosphinate ions and diethylphosphinate ions possess high thermal stability and extremely high flame retardancy. Therefore, they do not require the use of synergistic agents and can achieve flame retardancy of polymer materials even when used alone, while also producing less smoke when the flame-retardant material burns. [Overview of the project]

[0005] To solve the above technical problems, the present invention provides a dialkylphosphinate hybrid salt, a method for preparing the same, and its use. The dialkylphosphinate hybrid salt comprises a dialkylphosphinate hybrid salt represented by formula (I). The hybrid salt has high thermal stability, requires a small amount of additive, has high flame retardancy efficiency for various polymer materials, produces little smoke, can meet the processing requirements of engineering plastics that require high temperatures, and is highly economical.

[0006] According to a first aspect of the present invention, a dialkylphosphinate hybrid salt is provided. The dialkylphosphinate hybrid salt is at least one compound selected from compounds having the chemical formula represented by formula (I). In the formula JPEG0007912093000001.jpg20170, M is the central atom, and R1 and R2 are independently C4-C. 12 The alkyl groups are selected, and at least one of R1 and R2 is not an isobutyl group. Diethylphosphinate ion, ethyl R1 group phosphinate ion, and R1 group R2 group phosphinate ion are all ligands. M is selected from metallic elements, and the metallic element is at least one selected from group IIA, IIIA, IVA, VA metallic elements, transition metal elements, and lanthanide metallic elements. n is the valence of the metal element M, and n is selected from 2, 3, or 4. At least two of the ethyl R1 phosphinate ions, diethyl phosphinate ions, and R1-R2 phosphinate ions must coordinate to the same central atom M, and one of them must have an ethyl R1 phosphinate ion as its ligand coordinating to the central atom M. 0≦x≦0.76, 0.05≦y≦0.76, 0≦z≦0.76, and x+y+z=1.

[0007] In the embodiment of the present invention, R1 and R2 are each independently C4-C 12 Selected from alkyl groups. They may be the same or different. At least one of R1 and R2 is not an isobutyl group. C4-C 12 The alkyl group may be linear or branched alkyl, and may be n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, sec-pentyl group, tert-pentyl group, n-hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, n-heptyl group, isoheptyl group, sec-heptyl group, tert-heptyl group, n-octyl group This includes, but is not limited to, tyl groups, isooctyl groups, sec-octyl groups, tert-octyl groups, n-nonyl groups, sec-nonyl groups, tert-nonyl groups, n-decyl groups, isodecyl groups, sec-decyl groups, tert-decyl groups, n-undecyl groups, isoundecyl groups, sec-undecyl groups, tert-undecyl groups, n-dodecyl groups, isododecyl groups, sec-dodecyl groups, and tert-dodecyl groups.

[0008] In the present invention, when R1 or R2 contains a mixture of isomers, substances that are isomers of each other are treated as the same substance when calculating the y value. For example, when R1 is a butyl group, it includes n-butyl, isobutyl, sec-butyl, and tert-butyl groups. When calculating y in formula (I), the ethylbutylphosphinate ion (R1=butyl in formula (1)) includes ethyl-n-butylphosphinate ion, ethyl isobutylphosphinate ion, ethyl-sec-butylphosphinate ion, and ethyl-tert-butylphosphinate ion. y is the ratio of the total number of moles of these four types of ethylbutylphosphinate ions to the total number of moles of all dialkylphosphinate ions (i.e., the sum of the number of moles of diethylphosphinate ions, the number of moles of ethylbutylphosphinate ions, and the number of moles of R1 and R2 phosphinate ions). When calculating z in formula (I), if both R1 and R2 have isomers, similarly, substances that are isomers of each other are treated as the same substance using the method described above. In the embodiments of the present invention, when x exceeds 0.76 in formula (I), flame retardancy decreases. When Z exceeds 0.76, thermal stability decreases, which is unfavorable for the preparation and physical performance of the flame-retardant polymer material. When y exceeds 0.76, the preparation cost is high, and the economic efficiency is poor.

[0009] Selectively, the lower limit of x is independently chosen from 0, 0.01, 0.03, 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30, and the upper limit is independently chosen from 0.76, 0.70, 0.67, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, and 0.35.

[0010] Selectively, the lower limit of y is independently chosen from 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, and 0.40, and the upper limit is independently chosen from 0.76, 0.70, 0.67, 0.65, 0.60, 0.55, 0.50, and 0.45.

[0011] Selectively, the lower bound of z is independently chosen from 0, 0.001, 0.005, 0.01, 0.02, 0.03, 0.05, and 0.08, and the upper bound is independently chosen from 0.76, 0.70, 0.67, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.20, 0.15, and 0.10.

[0012] Selectively, the group IIA metallic element is at least one selected from Be, Mg, Ca, Sr, and Ba. The aforementioned Group IIIA metallic element is Al. The aforementioned IVA group metallic element is Sn. The aforementioned VA group metallic element is Sb. The transition metal element is at least one selected from Fe, Zn, Cu, Ti, Zr, and Mn. The aforementioned lanthanide metal element is Ce.

[0013] Selectively, the metal element is at least one selected from Al, Zn, Ca, and Fe.

[0014] Selectively, the metal element is Al, and n=3.

[0015] Selectively, 0 ≤ x ≤ 0.76, 0.05 ≤ y ≤ 0.67, and 0.005 ≤ z ≤ 0.76.

[0016] Selectively, 0 ≤ x ≤ 0.70, 0.05 ≤ y ≤ 0.67, and 0.005 ≤ z ≤ 0.70.

[0017] Selectively, 0.1 ≤ x ≤ 0.65, 0.30 ≤ y ≤ 0.67, and 0.01 ≤ z ≤ 0.50.

[0018] Selectively, 0.30 ≤ x ≤ 0.65, 0.30 ≤ y ≤ 0.65, and 0.02 ≤ z ≤ 0.40.

[0019] In the embodiments of the present invention, the larger the z value, the faster the thermoweight loss of the dialkylphosphinate hybrid salt.

[0020] The dialkylphosphinate hybrid salts in this invention are not simple physical mixtures of different dialkylphosphinates. For example, when R1 and R2 are butyl groups, they are not simple mixtures of aluminum diethylphosphinate, aluminum ethylbutylphosphinate, and aluminum dibutylphosphinate, but rather hybrid salts composed of at least two acid ions from diethylphosphinate ions, ethylbutylphosphinate ions, and dibutylphosphinate ions coordinated to the same aluminum atom, with one ligand of this hybrid salt being the ethylbutylphosphinate ion. The X-ray diffraction (XRD) spectra of these hybrid salts differ significantly from those of simple physical mixtures of dialkylphosphinates. A dialkylphosphinate hybrid salt having the composition of formula (I) shows a single peak in the region of strongest absorption peaks in the XRD spectrum. In contrast, the physical mixed salt obtained by simply mixing aluminum diethylphosphinate and aluminum dibutylphosphinate shows two completely independent peaks in the XRD spectrum, and their d values ​​are close to the d values ​​of aluminum diethylphosphinate and aluminum dibutylphosphinate, respectively.

[0021] In the embodiments of the present invention, when a dialkylphosphinate hybrid salt having the composition of formula (I) is simply mixed with aluminum diethylphosphinate or aluminum dibutylphosphinate, two independent peaks appear in the region of the strongest absorption peak in their XRD spectra. These results strongly indicate that the dialkylphosphinate hybrid salt having the composition of formula (I) obtained in the present invention is not a simple mixture of aluminum diethylphosphinate, ethyl R1 phosphinate, or R1-R2 phosphinate, but rather has a structure in which at least two of the acid ions among diethylphosphinate ions, ethyl R1 phosphinate ions, and R1-R2 phosphinate ions are coordinated to the same aluminum atom, and that one of the ligands is the ethyl R1 phosphinate ion.

[0022] In the embodiments of the present invention, at the same dose, pure long-chain aluminum dialkylphosphinate (R1, R2 are C4-C 12 Alkyl compounds have low thermal stability, making it difficult to meet the requirements of polymer materials that require high-temperature processing, and their flame retardancy is not high. In actual use, when polymers flame-retardanted with long-chain aluminum dialkylphosphinate burn, they produce more smoke compared to systems flame-retardanted with aluminum diethylphosphinate. However, even when using pure aluminum diethylphosphinate alone, the flame retardancy is not high. It is difficult to provide a good flame retardant effect to polymer materials when used alone. In contrast, the dialkylphosphinate hybrid salt having the composition of formula (I) has higher thermal stability, produces less smoke, and exhibits a higher flame retardant effect than both pure aluminum diethylphosphinate and pure long-chain aluminum dialkylphosphinate, which is quite unexpected.

[0023] According to a second aspect of the present invention, a method for preparing the dialkylphosphinate hybrid salt is provided. The preparation method is as follows: The process includes the step of carrying out a reaction I in an aqueous phase with a raw material containing mixture A and a source of metal element M to obtain the dialkylphosphinic acid hybrid salt. The mixture A comprises diethylphosphinic acid and / or its alkali metal salt, ethyl R1-group phosphinic acid and / or its alkali metal salt, and R1-R2-group phosphinic acid and / or its alkali metal salt.

[0024] Selectively, the conditions for reaction I are a temperature of 0-250°C, a pressure of 0.1 MPa-10 MPa, and a time of 0.01-20 h.

[0025] Selectively, reaction I is carried out at a pH of 0 to 4.

[0026] Selectively, the metal element is Al, and the pH of reaction I is 0 to 4, preferably 1 to 3.5, more preferably 2.3 to 3.3.

[0027] Specifically, in reaction I, if the pH is too low, no precipitate will form. If the pH is too high, metal ion hydroxides will be generated, resulting in the introduction of impurities.

[0028] Selectively, the molar ratio of diethylphosphinic acid and / or its alkali metal salt, ethyl R1-group phosphinic acid and / or its alkali metal salt, R1-group R2-group phosphinic acid and / or its alkali metal salt to the metal element M source is x:y:z:q or close to it, where q = 1 / n.

[0029] Selectively, the molar ratio of diethylphosphinic acid and / or its alkali metal salt, ethyl R1-group phosphinic acid and / or its alkali metal salt, and R1-R2-group phosphinic acid and / or its alkali metal salt in mixture A is the same as or substantially the same as the ratio of x, y, and z in formula (I).

[0030] Due to the difference in M, the solubility of the hybrid salt in water is different. For the hybrid salt with high solubility, the value calculated by the number of moles of diethylphosphinic acid and / or its alkali metal salt, ethyl R1 group phosphinic acid and / or its alkali metal salt, R1 group R2 group phosphinic acid and / or its alkali metal salt in the mixture A is different from the values of x, y, z in the hybrid salt, so the molar ratio with the M source also changes. Also, in order to obtain more M-containing precipitates, when adding raw materials, the molar ratio of x, y, z corresponding to the reactants and M may exceed the theoretical calculated value.

[0031] In the actual operation process, the actual values of x, y, z and q are judged by phosphorus nuclear magnetic resonance.

[0032] Optionally, the acquisition of the mixture A includes the following steps. Ethylene and C4-C 12 olefins are introduced into an aqueous solution containing phosphinic acid and / or its alkali metal salt and a free radical initiator, and reaction II is carried out to obtain the mixture A.

[0033] Optionally, the molar ratio of the phosphinic acid and / or its alkali metal salt, ethylene, C4-C 12 olefins is 1:0.24 - 1.76:1.76 - 0.24.

[0034] In the actual reaction, due to the existence of some side reactions such as the polymerization of ethylene and / or C4-C 12 olefins to obtain longer-chain dialkylphosphinate salts, etc., the consumption of ethylene and / or C4-C 12 olefins is higher than the theoretical value.

[0035] Optionally, the phosphinic acid and / or its alkali metal salt, ethylene, C4-C 12The molar ratio of olefins is the same as or close to the theoretical value calculated according to formula (I)n for x, y, and z values. In the reaction process between phosphinic acid or its alkali metal salt and ethylene or other olefins, the y value has a maximum value less than 1. Depending on the type of olefin, this maximum value is 0.76 or less, and is generally about 0.66. After reaching this maximum value, x or z becomes high, so y never reaches 1. Attempting to prepare y=1 is economically uneconomical because it requires separating and purifying the reaction intermediate products to remove diethylphosphinic acid and / or its alkali metal salts, as well as R1-R2 phosphinic acid and / or its alkali metal salts.

[0036] Specifically, in reaction II, ethylene and C4-C 12 The order in which the olefins are added can be interchanged; they may be added simultaneously, or some may be added first.

[0037] Selectively, in reaction II, phosphinic acid and / or its alkali metal salt are first C4-C 12 It reacts with olefins to obtain the corresponding y and z values, and then reacts completely or nearly completely with ethylene. Nearly complete reaction means that the total amount of phosphorus in the ethylphosphinate ion, R1-group phosphinate ion, R2-group phosphinate ion, and phosphinate ion in the reaction mixture is less than 5% mole of the total phosphorus in the reaction mixture.

[0038] Selectively, in reaction system II, the mass of water is 10-99% of the total mass of the aqueous solution.

[0039] Specifically, in the above-mentioned reaction system II, if there is too little water, the solubility of the olefin in water decreases due to the salting-out effect, slowing down the reaction rate. On the other hand, if there is too much water, the utilization rate of the reactor decreases.

[0040] Selectively, in reaction system II, the mass of water is 20-95% of the total mass of the aqueous solution.

[0041] Selectively, in reaction system II, the mass of water is 45-92% of the total mass of the aqueous solution.

[0042] Selectively, in reaction system II, the mass of water is 50-90% of the total mass of the aqueous solution.

[0043] Selectively, in reaction system II, the mass of water is 55-90% of the total mass of the aqueous solution.

[0044] Selectively, the conditions for reaction II are a temperature of 0-250°C, a time of 0.01-50 hours, and a pressure of 0-3 MPa.

[0045] Specifically, if the temperature of reaction II is too low, the reaction rate will be slow, while if the temperature is too high, the phosphinate will decompose more easily.

[0046] Selectively, the temperature of reaction II is 10-200°C.

[0047] Specifically, when the pressure of reaction II exceeds 3 MPa, the demands on the reaction equipment increase, making operation difficult.

[0048] Selectively, the pressure of reaction II is 0.2–1.5 MPa.

[0049] Selectively, the molar ratio of the free radical initiator to the phosphinic acid and / or its alkali metal salt is 0.001-0.1:1.

[0050] Selectively, the molar ratio of the free radical initiator to the phosphinic acid and / or its alkali metal salt is 0.003-0.05:1.

[0051] Selectively, the free radical initiator is at least one selected from azo initiators, peroxide initiators, and photoinitiators. Here, the amount of free radical initiator added can be determined according to actual requirements.

[0052] Selectively, the azo initiator is selected from cationic and / or non-cationic azo initiators and comprises one or more of azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-amidinopropane)dihydrochloride, and 2,2'-azodipropylamidine dihydrochloride.

[0053] Selectively, the peroxide-based initiator is preferably an inorganic peroxide and an organic peroxide, and particularly preferably one or more of hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, sodium percarbonate, benzoyl peroxide, di-tert-butyl peroxide, tert-butyl perbenzoate, and peracetic acid.

[0054] Preferably, the free radical initiator is a peroxide-based initiator. Particularly preferably, the free radical initiator is one selected from ammonium persulfate, potassium persulfate, and sodium persulfate.

[0055] Selectively, obtaining mixture A includes the following steps: A C4-C 12 The olefin is introduced and reacted, and the introduced C4-C 12 After the molar ratio of olefin to total phosphorus of phosphinic acid and / or its alkali metal salt reaches (y+2z) / 1 in formula (I), C4-C 12 The introduction of olefins is stopped, and ethylene is introduced and the reaction is continued to obtain the mixture A. Here, C4-C 12 Olefins are pure C4-C 12 Olefin or C4-C 12 A mixed olefin may also be used.

[0056] Selectively, obtaining mixture A includes the following steps: A C4-C 12 Introducing an olefin, the C4-C12 After the olefin has reacted completely or almost completely, ethylene is subsequently introduced and the reaction continues to obtain mixture A. Here, C4-C 12 Olefins are pure C4-C 12 Olefin or C4-C 12 A mixed olefin may also be used.

[0057] Selectively, phosphinic acid and / or its alkali metal salts are C4-C 12 A single R1 group phosphinic acid or its alkali metal salt having a y value or a value substantially close to the y value is obtained by reacting it with an olefin, and z is controlled to 0.76 or less, and then C4-C 12 The introduction of olefins is stopped, and instead, ethylene is introduced, and the reaction continues in the presence of an initiator, and then the required metal salt is reacted to obtain a flame retardant having formula (I). Here, C4-C 12 Olefins are pure C4-C 12 Olefin or C4-C 12 A mixed olefin may also be used.

[0058] Selectively, obtaining mixture A includes the following steps: A C4-C 12 By introducing olefins and some ethylene, the C4-C 12 After the olefin and some of the ethylene have reacted completely or almost completely, the remaining ethylene is introduced and the reaction continues to obtain the mixture A. Here, C4-C 12 Olefins are pure C4-C 12 Olefin or C4-C 12 A mixed olefin may also be used.

[0059] Selectively, obtaining mixture A includes the following steps: A C4-C 12The reaction is carried out by introducing olefins and some ethylenes. The molar ratio of ethylene to phosphinic acid and / or its alkali metal salts to total phosphorus is less than (2x+y) / 1 in equation (I). The introduced C4-C 12 After the molar ratio of olefin to total phosphorus of phosphinic acid and / or its alkali metal salt reaches (y+2z) / 1 in formula (I), C4-C 12 The introduction of olefins is stopped, and the remaining ethylene is continued to be introduced and the reaction is carried out to obtain mixture A. Here, C4-C 12 Olefins are pure C4-C 12 Olefin or C4-C 12 A mixed olefin may also be used.

[0060] Selectively, obtaining mixture A includes the following steps: A portion of ethylene is introduced into an aqueous solution containing phosphinic acid and / or its alkali metal salt and a free radical initiator, such that the molar ratio of the portion of ethylene to the total phosphorus of the phosphinic acid and / or its alkali metal salt is less than or equal to (2x+y) / 1 in equation (I). After the portion of ethylene has completely reacted, C4-C 12 The olefin is introduced and the reaction is carried out, and the introduced C4-C 12 After the molar ratio of olefin to total phosphorus of phosphinic acid and / or its alkali metal salt reaches (y+2z) / 1 in formula (I), C4-C 12 The introduction of olefins is stopped, and the remaining ethylene is continued to be introduced and the reaction is carried out to obtain mixture A. Here, C4-C 12 Olefins are pure C4-C 12 Olefin or C4-C 12 A mixed olefin may also be used.

[0061] Selectively, obtaining mixture A includes the following steps: A portion of ethylene is introduced into an aqueous solution containing phosphinic acid and / or its alkali metal salt, and a free radical initiator, and after the portion of ethylene has reacted completely or nearly completely, C4-C 12 Introducing an olefin and carrying out the reaction, the C4-C 12After the olefin has reacted completely or almost completely, the remaining ethylene is introduced and reacted to obtain mixture A. Here, C4-C 12 Olefins are pure C4-C 12 Olefin or C4-C 12 A mixed olefin may also be used.

[0062] Selectively, the total amount of ethylene and the C4-C 12 The molar ratio with olefin is 0.14-7.33:1.

[0063] Selectively, the metal element M source is at least one selected from the metal element M salts.

[0064] Selectively, the metal element M salt is at least one selected from nitrates, sulfates, hydrochlorides, acetates, and oxides of the metal element M.

[0065] Selectively, phosphinic acid and / or its alkali metal salts are C4-C 12 Olefins and some ethylenes react simultaneously in the presence of a free radical initiator, C4-C 12 The amounts of olefin and ethylene are controlled. In the reaction system, the molar percentage of ethyl R1 group phosphinic acid or its alkali metal salt is close to the y value, and the molar percentage of R1 group R2 group phosphinic acid or its alkali metal salt is close to the z value, and z is 0.76 or less. 12 The addition of olefins is stopped, and the remaining ethylene is introduced and the reaction is continued in the presence of the initiator until it is completely reacted, and then the required metal salt is reacted to obtain a dialkylphosphinate hybrid salt having formula (I). Here, C4-C 12 Olefins are pure C4-C 12 Olefin or C4-C 12 A mixed olefin may also be used.

[0066] Selectively, obtaining mixture A includes the following steps: Ethylene is introduced into an aqueous solution containing phosphinic acid and / or its alkali metal salt, and a free radical initiator, and the amount of ethylene is controlled. After the molar ratio of the introduced ethylene to the total phosphorus of the phosphinic acid and / or its alkali metal salt reaches (y+2x) / 1 in equation (I), the introduction of ethylene is stopped, and C4-C 12 The olefin is added and the reaction is continued in the presence of an initiator until it is completely reacted to obtain mixture A. Here, C4-C 12 Olefins are pure C4-C 12 Olefin or C4-C 12 A mixed olefin may also be used.

[0067] Specifically, after reaction II is complete, there is no need to separate diethylphosphinic acid, ethyl R1-group phosphinic acid, R1-group R2-group phosphinic acid and / or their alkali metal salts; the next reaction can proceed directly.

[0068] A third aspect of the present invention provides a flame retardant. The flame retardant is at least one selected from the dialkylphosphinate hybrid salt and the dialkylphosphinate hybrid salt prepared by the method described above.

[0069] Selectively, the flame retardant further includes at least one selected from phosphates, phosphates, alkylphosphonates, and alkylphosphinates. The molar content of these phosphorus-containing impurities in the flame retardant is 10% or less, and the number of moles of the flame retardant is calculated based on the number of moles of phosphorus contained therein.

[0070] According to a fourth aspect of the present invention, a flame-retardant material is provided. The flame-retardant material comprises a flame retardant P and a thermoplastic polymer material. The flame retardant P is at least one selected from the flame retardants.

[0071] Selectively, the flame retardant P has a mass content of 1-35% in the flame retardant material.

[0072] Selectively, the flame retardant material comprises 1-35 wt% of a flame retardant P and 65-99 wt% of a thermoplastic polymer material.

[0073] In this invention, the term "thermoplastic polymer material" refers to a plastic that has the property of softening when heated and hardening when cooled.

[0074] Specifically, the amount of flame retardant P used depends on the thermoplastic polymer material.

[0075] Selectively, the flame retardant P is present in a mass content of 3-20% in the flame retardant material.

[0076] Selectively, the flame retardant material further contains functional additives. The functional additive comprises at least one selected from reinforcing agents, anti-dropping agents, stabilizers, pigments, dyes, carbon generation catalysts, dispersants, nucleating agents, inorganic fillers, and antioxidants. Preferably, the functional additive is present in the flame retardant material at a mass content of 5-40%.

[0077] Selectively, the reinforcing agent is selected from glass fibers.

[0078] The drip-preventing agent is selectively selected from Teflon.

[0079] Selectively, the inorganic filler is at least one selected from mica, calcium carbonate, calcium oxide, and silica.

[0080] Selectively, the flame retardant further contains flame retardant Q. The flame retardant Q is at least one selected from nitrogen-based flame retardants and boron-based flame retardants.

[0081] Selectively, the nitrogen-based flame retardant is at least one selected from melamine cyanurate, melamine polyphosphate, and ammonium polyphosphate. The boron-based flame retardant is selected from zinc borate.

[0082] Selectively, the flame retardant Q has a mass content of 0.5-20% in the flame retardant material.

[0083] Selectively, the thermoplastic polymer material is at least one selected from polyamide and polyester.

[0084] Selectively, the polyamide is at least one selected from aliphatic polyamides, aromatic polyamides, semi-aromatic polyamides, and copolymers of semi-aromatic polyamides and aliphatic polyamides.

[0085] According to the ordinary knowledge of the art, polyamides, also known as nylon, are a general term for polymers containing an -NH-C(O)-amide group in their structural units, and are synthesized by condensation or ring-opening reactions of one or more dicarboxylic acids and one or more diamines, and / or one or more amino acids, and / or one or more lactams. Based on the composition of their main chain, polyamides are usually classified into aliphatic polyamides, aromatic polyamides, and semi-aromatic polyamides. Semi-aromatic polyamides are those in which at least one monomer structure of the synthetic monomer contains an aromatic group.

[0086] Selectively, the aliphatic polyamide is a copolymer of polyamide 6 and polyamide 66, or a mixture of one or more polyamides arbitrarily selected from polyamide 6 and polyamide 66.

[0087] Selectively, the semi-aromatic polyamide can be prepared using any one or more aromatic dicarboxylic acids and any one or more aliphatic diamines, or using any one or more aromatic diamines and any one or more aliphatic dicarboxylic acids. A polyamide copolymer having the corresponding properties can be prepared by further adding one or more selected from dicarboxylic acids, diamines, lactams, and amino acids to the reaction system. The added dicarboxylic acid is an aromatic dicarboxylic acid and / or an aliphatic dicarboxylic acid. The added diamine is an aromatic diamine and / or an aliphatic diamine. The added lactam may be an aliphatic or aromatic lactam. The added amino acid may be an aromatic or aliphatic amino acid.

[0088] Selectively, the semi-aromatic polyamide is prepared using one or more aromatic dicarboxylic acids selected from terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and one or more aliphatic diamines selected from butanediamine, hexamethylenediamine, octanediamine, decanediamine, and 2-methylpentanediamine.

[0089] Selectively, the semi-aromatic polyamides are prepared using aliphatic diamines, aromatic dicarboxylic acids, and aliphatic dicarboxylic acids.

[0090] Selectively, the semi-aromatic polyamide is prepared using an aliphatic diamine and an aromatic dicarboxylic acid. Selectively, an aliphatic dicarboxylic acid may be further added. The mole fraction of the aliphatic dicarboxylic acid is 0-45% of the total amount of dicarboxylic acid. That is, the number of moles of aliphatic dicarboxylic acid / (number of moles of aliphatic dicarboxylic acid + number of moles of aromatic dicarboxylic acid) = 0-45%.

[0091] Selectively, the aromatic dicarboxylic acid is one or more selected from terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid. The aliphatic diamine is one or more selected from butanediamine, hexamethylenediamine, octanediamine, decanediamine, and 2-methylpentanediamine. The aliphatic dicarboxylic acid is one or more selected from adipic acid, succinic acid, sebacic acid, and suberic acid.

[0092] Selectively, the polyamides include polyhexamethylene terephthalamide (abbreviated as PA6T), polyhexamethylene isophthalamide (abbreviated as PA6I), terephthalic acid / hexamethylenediamine / caprolactam copolymer (abbreviated as PA6T / 6), terephthalic acid / hexamethylenediamine / adipic acid copolymer (abbreviated as PA6T / 66), terephthalic acid / hexamethylenediamine / adipic acid / isophthalic acid copolymer (abbreviated as PA6T / 6I / 66), polynonameethylene terephthalamide (abbreviated as PA9T), and polydecanediamine. It is one or more selected from terephthalamide (abbreviated as PA10T), polidodecylterephthalamide (abbreviated as PA12T), terephthalic acid / hexamethylenediamine / deuterolactam copolymer (abbreviated as PA6T / 12), poly(m-xylyleneadipamide) (abbreviated as MXD6), terephthalic acid / hexamethylenediamine / 2-methylpentanediamine copolymer (abbreviated as PA6T / 2-MPMDT), and terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine copolymer.

[0093] Selectively, the aliphatic polyamide is at least one selected from polyamide 6, polyamide 66, and a copolymer of polyamide 6 and polyamide 66.

[0094] Selectively, the semi-aromatic polyamide is selected from polyphthalamides (PPAs).

[0095] Selectively, the polyester is selected from polybutylene terephthalate (PBT).

[0096] In the embodiments of the present invention, the values ​​of x, y, and z in formula (I) are x+y+z=1 and x+z>0, without considering the amount of other phosphorus-containing impurities. The flame retardant having the composition of formula (I) may contain trace amounts of other phosphorus-containing impurities. Due to impurities being present in the raw materials or generated during the synthesis process, some trace amounts of phosphates, phosphates, alkylphosphonates, and alkylphosphinates may be present in the flame retardant. Some ethylene and / or C4-C 12 Telomer products obtained by polymerizing or copolymerizing olefins, such as ethyl-n-tetradecylphosphinate and ethylhexadecylphosphinate, may also be present as impurities in flame retardants having the composition of formula (I). However, if the total molar amount of these other phosphorus-containing ions is 5% or less of the total molar amount of phosphorus, it will not affect the normal function of the flame retardant having the composition of formula (I).

[0097] In the embodiments of the present invention, the proportions of x, y, and z in formula (I) are determined after the flame retardant is subjected to alkaline hydrolysis or acid hydrolysis. 31 This can be determined by P-NMR (nuclear magnetic resonance). Diethylphosphinate ions, ethyl R1-group phosphinate ions, and R1-group R2-group phosphinate ions are different. 31 It has a chemical shift of P, 31 In many cases, independent peaks appear in the P-NMR spectrum.

[0098] The peak areas of these peaks correspond to the molar concentrations of each dialkylphosphinate ion, and some dialkylphosphinate ions with the same chemical formula may exhibit different peaks in the phosphorus nuclear magnetic resonance spectrum because they have isomers. When calculating the x, y, and z values, these isomers are treated as the same substance. For example, when R1 and R2 are butyl groups, the resulting dialkylphosphinate hybrid salt 31Five groups of peaks appear in the P-NMR spectrum. These five groups of peaks correspond to the ethyl-sec-butylphosphinate ion, n-butyl-sec-butylphosphinate ion, diethylphosphinate ion, ethyl-n-butylphosphinate ion, and di-n-butylphosphinate ion, respectively. Here, the molar concentration of the diethylphosphinate ion corresponds to x, the sum of the molar concentrations of ethyl-sec-butylphosphinate ion and ethyl-n-butylphosphinate ion (collectively referred to as the molar concentration of ethylbutylphosphinate ion) corresponds to y, and the sum of the molar concentrations of di-n-butylphosphinate ion and n-butyl-sec-butylphosphinate ion (collectively referred to as the molar concentration of dibutylphosphinate ion) corresponds to z. The ratio of these three is the value of x, y, and z. In this case, telomerized alkylphosphinate ions are present, and since their amount is very small and their chemical shift is close to that of the corresponding dialkylphosphinate ion, they are attributed to the corresponding dialkylphosphinate ion during integration.

[0099] The beneficial effects of the present invention are as follows: (1) The dialkylphosphinate hybrid salt having the composition of formula (I) provided in the present invention requires a small amount of additive, has high thermal stability, high flame retardancy efficiency for polymer materials, and is economical. It overcomes the disadvantage of low flame retardancy efficiency for polymer materials when using diethylphosphinate and long-chain dialkylphosphinate alone, and also overcomes the disadvantage of low thermal stability and high amount of flame retardant smoke of long-chain dialkylphosphinate, so it can be widely used for flame retardation of polymer materials that require high-temperature processing. (2) The present invention provides a method for preparing dialkylphosphinic acid hybrid salts. This avoids the drawback of having to prepare different dialkylphosphinic acids independently, and is environmentally friendly as it uses water as the reaction solvent, the raw materials are readily available, and it is economically efficient. [Brief explanation of the drawing]

[0100] [Figure 1]This is a graph of the thermogravimetric loss of dialkylphosphinate hybrid aluminum salts (where R1 and R2 in formula (I) are butyl groups, and the C4-C12 olefin used in reaction II is butene), aluminum diethylphosphinate, and aluminum dibutylphosphinate, each having different x, y, and z values. [Figure 2] Figures 2a and 2b are XRD curves of dialkylphosphinate hybrid aluminum salts (where R1 and R2 in formula (I) are butyl groups, and the C4-C12 olefin used in reaction II is butene), aluminum diethylphosphinate, aluminum dibutylphosphinate, and a physical mixed salt of aluminum dibutylphosphinate and aluminum diethylphosphinate, each with different x, y, and z values. Here, Figure 2b is a magnified view of a portion of the strongest absorption peak in Figure 2a. [Figure 3] This is the 31P-NMR spectrum after alkaline hydrolysis of the dialkylphosphinic acid hybrid salt prepared in Example 3 (where R1 and R2 in formula (I) are butyl groups, and the C4-C12 olefin used in reaction II is butene). [Figure 4] This is the 31P-NMR spectrum after alkaline hydrolysis of the dialkylphosphinic acid hybrid salt prepared in Example 4 (where R1 and R2 in formula (I) are butyl groups, and the C4-C12 olefin used in reaction II is butene). [Modes for carrying out the invention]

[0101] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0102] Unless otherwise specified, all raw materials used in the embodiments of this invention were purchased through commercial channels.

[0103] The raw materials used in the examples are as follows: PA66 (also known as polyamide 66 or nylon 66): Zytel 70G35 HSL NC010 from DuPont, USA, with a glass fiber content of 35% by weight. PA6 (also known as polyamide 6 or nylon 6): Zytel 73G30L NC010 from DuPont, USA, with a glass fiber content of 30% by weight. ADP: Aluminum diethylphosphinate, ExolIt OP1230 from Clariant GmbH, Germany. MPP: Melamine polyphosphate, Suzhou Kaima Chemical Technology Co., Ltd. Zinc borate: Sinopharmaceutical Group Chemical Reagents Co., Ltd. Antioxidant 1010: Tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester, Shanghai McLean Biochemical Technology Co., Ltd. Antioxidant 168: Tri[2,4-di-tert-butylphenyl] phosphite, Strem, USA Combined antioxidant: A mixture of antioxidant 1010 (tetra[β-(3,5-di-tert-butyl-4-hydroxyphenylpropionic acid]pentaerythritol ester) and antioxidant 168 (tri[2,4-di-tert-butylphenyl] phosphite) in a 1:1 weight ratio. Combustion test standard: GB / T 2408-2008 standard Nuclear Magnetic Resonance-Phosphorus (NMR) Test: Instruments used: AVANCE III 600MHz and AVANCE III 400MHz, Bruker GmbH, Germany. Nuclear magnetic resonance-phosphorus spectrum ( 31 P-NMR) Test method: Preliminary delay D1 = 10 seconds, 32 scans, the ratio of peak areas is taken as the ratio of the number of moles of each phosphonate ion. Model number of the instrument used for the X-ray diffraction (XRD) test: D8 ADVANCE DAVINCI, Bruker GmbH, Germany Equipment model used for TGA thermogravimetric treatment: Q500, TA Corporation, USA, nitrogen atmosphere, heating rate 10°C / min

[0104] Example 1 Preparation of a hybrid salt having the composition of formula (I): x=0.40, y=0.56, z=0.04, M=Al, n=3 100g of sodium phosphinate monohydrate was dissolved in 500g of water and placed in a 1L stainless steel pressure vessel. The reactor was purged twice with nitrogen gas, evacuated, and then butene was introduced until the pressure stopped rising. The reaction mixture was heated to approximately 90°C, and after the pressure gauge showed 0.25 MPa, a 4% sodium persulfate aqueous solution was added at a constant rate of 10 ml / h, continuing to introduce butene into the reactor, and the amount of olefin introduced was measured with a gas flow meter. After 4 hours, the introduction of butene was stopped and ethylene was introduced. After 12 hours, the pressure in the reactor stopped decreasing, so it was cooled to release the pressure, purged with N2, and the materials were discharged to obtain a colorless, transparent reaction solution. The reaction solution was sampled during and at the end of the reaction. 31 Table 1 shows the results of the P-NMR nuclear magnetic resonance measurements.

[0105] [Table 1] Note: In the table, ethylbutylphosphinate ion includes ethyl-sec-butylphosphinate ion and ethyl-n-butylphosphinate ion, dibutylphosphinate ion includes n-butyl-sec-butylphosphinate ion (R1≠R2, n-butyl and sec-butyl respectively) and di-n-butylphosphinate ion (R1=R2=n-butyl), and other douplication products include di-sec-butylphosphinate ion and telomerized alkylphosphinate ion polymerized with ethylene and / or butene. Butylphosphinate ion is the sum of sec-butylphosphinate ion and n-butylphosphinate ion, and butylphosphonate ion is the sum of sec-butylphosphonate ion and n-butylphosphonate ion. The same applies hereafter.

[0106] A portion of the above solution, 307.59 g (containing 0.36 moles of phosphorus), was slowly mixed at atmospheric pressure with 39.99 g of a 10% aluminum sulfate 18-hydrate aqueous solution. The reaction temperature was controlled to 70°C, and the pH was adjusted to 3.0 or less to obtain a large precipitate. After adding the raw materials and mixing, the mixture was incubated for 0.5 hours. The solution was thermally filtered, and the filtered cake was washed with clean water until the pH was >4.5. The filtered cake was then dried at 120°C to obtain 48.15 g of a white solid. The sample was dissolved in an aqueous sodium hydroxide solution, and phosphorus nuclear magnetic resonance measurements were performed. 31 As can be seen from the P-NMR spectrum, the molar content of diethylphosphinate ions was 40.23%, the molar content of ethyl-n-butylphosphinate ions was 51.98%, the molar content of ethyl-sec-butylphosphinate ions was 4.10%, and the molar content of di-n-butylphosphinate ions was 3.69%. The mole fractions of phosphinate ions with the same chemical formula were added together (i.e., the y value was calculated using the sum of ethyl-n-butylphosphinate ions and ethyl-sec-butylphosphinate ions), and the values ​​x=0.40, y=0.56, and z=0.04 were obtained.

[0107] XRD measurements of the sample revealed that the interlayer distance corresponding to the characteristic peak with the highest relative intensity obtained by XRD was 11.143 angstroms (100%).

[0108] Example 2 Preparation of a hybrid salt having the composition of formula (I): x=0, y=0.24, z=0.76, M=Al, n=3 100g of sodium phosphinate monohydrate was dissolved in 500g of water and placed in a 1L stainless steel pressure vessel. The reactor was purged twice with nitrogen gas, evacuated, and then butene was introduced until the pressure stopped rising. The reaction mixture was heated to approximately 90°C, and after the pressure gauge showed 0.25 MPa, a 4% sodium persulfate aqueous solution was added at a constant rate of 10 ml / h, continuing to introduce butene into the reactor, and the amount of olefin introduced was measured with a gas flow meter. After 8.5 hours, the introduction of butene was stopped, and the introduction of ethylene was started. After 15 hours, the pressure in the reactor stopped decreasing, so it was cooled to release the pressure, purged with N2, and the materials were discharged to obtain a colorless, transparent reaction mixture. The reaction mixture was sampled and measured by nuclear magnetic resonance. 31 The P-NMR results are shown in Table 2.

[0109] [Table 2]

[0110] A portion of the above solution, 353.74 g (containing 0.36 moles of phosphorus), was slowly mixed at atmospheric pressure with 39.99 g of a 10% aluminum sulfate 18-hydrate aqueous solution. The reaction temperature was controlled to 70°C, and the pH was adjusted to 3.0 or less to obtain a large precipitate. After adding the raw materials and mixing, the mixture was incubated for 0.5 hours. The solution was thermally filtered, and the filtered cake was washed with clean water until the pH was >4.5. The filtered cake was then dried at 120°C to obtain 66.54 g of a white solid. The sample was dissolved in an aqueous sodium hydroxide solution, and phosphorus nuclear magnetic resonance measurements were performed. 31As can be seen from the P-NMR spectrum, the molar content of ethyl-sec-butylphosphinate ions was 2.42%, the molar content of ethyl-n-butylphosphinate ions was 21.13%, the molar content of n-butyl-sec-butylphosphinate ions was 7.25%, the molar content of di-n-butylphosphinate ions was 68.63%, and the total molar content of other phosphorus-containing impurities, such as butylphosphinate ions and butylphosphonate ions, was 0.57%. The mole fractions of phosphinate ions with the same chemical formula were added (i.e., the y value was calculated by adding the mole fractions of ethyl-n-butylphosphinate ions and ethyl-sec-butylphosphinate ions; the z value was calculated by adding the mole fractions of n-butyl-sec-butylphosphinate ions and telomeres of dialkylphosphinate ions), and normalized to obtain x=0, y=0.24, and z=0.76.

[0111] XRD measurements of the sample revealed that the interlayer distance corresponding to the characteristic peak with the highest relative intensity obtained by XRD was 12.468 angstroms (100%).

[0112] Example 3 Preparation of a hybrid salt having the composition of formula (I): x=0, y=0.32, z=0.68, M=Al, n=3 100g of sodium phosphinate monohydrate was dissolved in 500g of water and placed in a 1L stainless steel pressure vessel. The reactor was purged twice with nitrogen gas, evacuated, and then butene was introduced until the pressure stopped rising. The reaction mixture was heated to approximately 90°C, and after the pressure gauge showed 0.25 MPa, a 4% sodium persulfate aqueous solution was added at a constant rate of 10 ml / h, continuing to introduce butene into the reactor, and the amount of olefin introduced was measured with a gas flow meter. After 7 hours, the introduction of butene was stopped, and the introduction of ethylene was started. After 15.5 hours, the pressure in the reactor stopped decreasing, so it was cooled to release the pressure, purged with N2, and the materials were discharged to obtain a colorless, transparent reaction mixture. The reaction mixture was sampled and measured by nuclear magnetic resonance. 31 The P-NMR results are shown in Table 3.

[0113] [Table 3]

[0114] A portion of the above solution, 334.45 g (containing 0.36 moles of phosphorus), was slowly mixed at atmospheric pressure with 39.99 g of a 10% aluminum sulfate 18-hydrate aqueous solution. The reaction temperature was controlled to 70°C, and the pH was adjusted to 3.0 or less to obtain a large precipitate. After adding the raw materials and mixing, the mixture was incubated for 0.5 hours. The solution was thermally filtered, and the filtered cake was washed with clean water until the pH was >4.5. The filtered cake was then dried at 120°C to obtain 64.81 g of a white solid. The sample was dissolved in an aqueous sodium hydroxide solution, and phosphorus nuclear magnetic resonance measurements were performed. 31 The P-NMR spectrum is shown in Figure 3. 31 As can be seen from the P-NMR spectrum, the molar content of ethyl-sec-butylphosphinate ions was 2.45%, the molar content of ethyl-n-butylphosphinate ions was 29.44%, the molar content of n-butyl-sec-butylphosphinate ions was 6.83%, and the molar content of di-n-butylphosphinate ions was 61.28%. The mole fractions of phosphinate ions with the same chemical formula were added together (i.e., the y value was calculated by adding the mole fractions of ethyl-n-butylphosphinate ions and ethyl-sec-butylphosphinate ions, and the z value was calculated by adding the mole fractions of n-butyl-sec-butylphosphinate ions and di-n-butylphosphinate ions), and normalized to obtain x=0, y=0.32, and z=0.68.

[0115] XRD measurements of the sample revealed that the interlayer distance corresponding to the characteristic peak with the highest relative intensity obtained by XRD was 12.319 angstroms (100%).

[0116] Example 4 Preparation of a hybrid salt having the composition of formula (I): x=0.02, y=0.63, z=0.35, M=Al, n=3 100g of sodium phosphinate monohydrate was dissolved in 500g of water and placed in a 1L stainless steel pressure vessel. The reactor was purged twice with nitrogen gas, evacuated, and then butene was introduced until the pressure stopped rising. The reaction mixture was heated to approximately 90°C, and after the pressure gauge showed 0.25 MPa, a 4% sodium persulfate aqueous solution was added at a constant rate of 10 ml / h, continuing to introduce butene into the reactor, and the amount of olefin introduced was measured with a gas flow meter. After 5.5 hours, the introduction of butene was stopped, and ethylene was introduced. After 13 hours, the pressure in the reactor stopped decreasing, so it was cooled to release the pressure, purged with N2, and the materials were discharged to obtain a colorless, transparent reaction mixture. The reaction mixture was sampled and measured by nuclear magnetic resonance. 31 The P-NMR results are shown in Table 4.

[0117] [Table 4]

[0118] A portion of the above solution, 329.57 (containing 0.36 moles of phosphorus), was slowly mixed at atmospheric pressure with 39.99 g of a 10% aluminum sulfate 18-hydrate aqueous solution. The reaction temperature was controlled to 70°C, and the pH was adjusted to 3.0 or less to obtain a large precipitate. After adding the raw materials and mixing, the mixture was incubated for 0.5 hours. The solution was thermally filtered, and the filtered cake was washed with clean water until the pH was >4.5. The filtered cake was then dried at 120°C to obtain 59.60 g of a white solid. The sample was dissolved in an aqueous sodium hydroxide solution, and phosphorus nuclear magnetic resonance measurements were performed. 31 The P-NMR spectrum is shown in Figure 4. 31As can be seen from the P-NMR spectrum, the molar content of diethylphosphinate ions was 1.99%, the molar content of ethyl-sec-butylphosphinate ions was 4.30%, the molar content of ethyl-n-butylphosphinate ions was 58.22%, the molar content of n-butyl-sec-butylphosphinate ions was 3.44%, the molar content of di-n-butylphosphinate ions was 30.67%, and the total molar content of other phosphorus-containing impurities, such as ethylphosphinate ions, butylphosphinate ions, ethylphosphonate ions, and butylphosphonate ions, was 1.38%. The mole fractions of phosphinate ions with the same chemical formula were added together (i.e., the y value was calculated by adding the mole fractions of ethyl-n-butylphosphinate ion and ethyl-sec-butylphosphinate ion, and the z value was calculated by adding the mole fractions of n-butyl-sec-butylphosphinate ion and di-n-butylphosphinate ion and dialkylphosphinate telomers. Here, the dialkylphosphinate telomers are also attributed to the similar di-n-butylphosphinate ion), and normalized to obtain x=0.02, y=0.63, and z=0.35.

[0119] XRD measurements of the sample revealed that the interlayer distance corresponding to the characteristic peak with the highest relative intensity obtained by XRD was 11.934 angstroms (100%).

[0120] Example 5 Preparation of a hybrid salt having the composition of formula (I): x=0.22, y=0.67, z=0.11, M=Al, n=3 100g of sodium phosphinate monohydrate was dissolved in 500g of water and placed in a 1L stainless steel pressure vessel. The reactor was purged twice with nitrogen gas, evacuated, and then butene was introduced. The reaction mixture was heated to approximately 90°C, and after the pressure gauge showed 0.15 MPa, a 4% sodium persulfate aqueous solution was added at a constant rate of 10 ml / h to continue introducing butene into the reactor, and the amount of olefin introduced was measured with a gas flow meter. After 7.5 hours, the introduction of butene was stopped, and the introduction of ethylene was started. After 21 hours, the pressure in the reactor had almost stopped decreasing, so it was cooled to release the pressure, purged with N2, and the materials were discharged to obtain a colorless, transparent reaction mixture. The reaction mixture was sampled and measured by nuclear magnetic resonance. 31 The P-NMR results are shown in Table 5.

[0121] [Table 5]

[0122] A portion of the above solution, 374.84 g (containing 0.36 moles of phosphorus), was slowly mixed at atmospheric pressure with 39.99 g of a 10% aluminum sulfate 18-hydrate aqueous solution. The reaction temperature was controlled to 70°C, and the pH was adjusted to 3.0 or less to obtain a large precipitate. After adding the raw materials and mixing, the mixture was incubated for 0.5 hours. The solution was thermally filtered, and the filtered cake was washed with clean water to a pH > 4.5. The filtered cake was then dried at 120°C to obtain 52.13 g of a white solid. The sample was dissolved in an aqueous sodium hydroxide solution, and phosphorus nuclear magnetic resonance measurements were performed. 31As can be seen from the P-NMR spectrum, the molar content of diethylphosphinate ions was 21.32%, the molar content of ethyl-sec-butylphosphinate ions was 4.52%, the molar content of ethyl-n-butylphosphinate ions was 62.02%, the molar content of n-butyl-sec-butylphosphinate ions was 1.11%, the molar content of di-n-butylphosphinate ions was 9.66%, and the total molar content of other phosphorus-containing impurities, such as ethylphosphinate ions, butylphosphinate ions, ethylphosphonate ions, butylphosphonate ions, and phosphite ions, was 1.37%. The mole fractions of phosphinate ions with the same chemical formula were added (i.e., the y value was calculated by adding the mole fractions of ethyl-n-butylphosphinate ion and ethyl-sec-butylphosphinate ion, and the z value was calculated by adding the mole fractions of n-butyl-sec-butylphosphinate ion and di-n-butylphosphinate ion), and normalized to obtain x=0.22, y=0.67, and z=0.11. XRD measurements of the sample showed that the interlayer distance corresponding to the characteristic peak with the highest relative intensity obtained by XRD measurement was 11.384 angstroms (100%).

[0123] Example 6 Preparation of a hybrid salt having the composition of formula (I): x=0.59, y=0.39, z=0.02, M=Al, n=3 100g of sodium phosphinate monohydrate was dissolved in 500g of water and added to a 1L stainless steel pressure vessel along with 39.7g of hexene. The reactor was purged twice with nitrogen gas, evacuated, and then some ethylene was introduced. The reaction mixture was heated to approximately 90°C, and then a 4% sodium persulfate aqueous solution was added at a constant rate of 10ml / h. After reacting for 8.5 hours, the remaining ethylene was introduced. After 14.5 hours, the reactor pressure stopped decreasing, so it was cooled to release the pressure, purged with N2, and the materials were discharged to obtain a colorless, transparent reaction solution. The reaction solution was sampled and measured by nuclear magnetic resonance. 31 The P-NMR results are shown in Table 6.

[0124] [Table 6] Note: In the table, ethylhexylphosphinate ions include ethyl-sec-hexylphosphinate ions and ethyl-n-hexylphosphinate ions; dihexylphosphinate ions include n-hexyl-sec-hexylphosphinate ions (R1≠R2, which are n-hexyl and sec-hexyl, respectively) and di-n-hexylphosphinate ions (R1=R2=n-hexyl); hexylphosphinate ions include sec-hexylphosphinate ions and n-hexylphosphinate ions; and hexylphosphonate ions are the sum of sec-hexylphosphonate ions and n-hexylphosphonate ions.

[0125] A portion of the above solution, 367.37 g (containing 0.36 moles of phosphorus), was slowly mixed at atmospheric pressure with 39.99 g of a 10% aluminum sulfate 18-hydrate aqueous solution. The reaction temperature was controlled to 70°C, and the pH was adjusted to 3.0 or less to obtain a large precipitate. After adding the raw materials and mixing, the mixture was incubated for 0.5 hours. The solution was thermally filtered, and the filtered cake was washed with clean water until the pH was >4.5. The filtered cake was then dried at 120°C to obtain 50.35 g of a white solid. The sample was dissolved in an aqueous sodium hydroxide solution, and phosphorus nuclear magnetic resonance measurements were performed. 31 As can be seen from the P-NMR spectrum, the molar content of diethylphosphinate ions was 57.54%, the molar content of ethylhexylphosphinate ions was 38.19%, and the molar content of dihexylphosphinate ions was 2.21%. The total molar content of other phosphorus-containing impurities, such as ethylphosphinate ions, hexylphosphinate ions, ethylphosphonate ions, hexylphosphonate ions, and phosphite ions, was 2.06%. After normalization, x=0.59, y=0.39, and z=0.02 were obtained. XRD measurements of the sample revealed that the interlayer distance corresponding to the characteristic peak with the highest relative intensity obtained by XRD was 11.639 angstroms (100%).

[0126] Example 7 Preparation of a hybrid salt having the composition of formula (I): x=0.01, y=0.52, z=0.47, M=Cu, n=2 A portion of the solution obtained in the first step of Example 4 (containing 0.15 moles of phosphorus) was slowly mixed at atmospheric pressure with 18.73 g of a 25% mass concentration aqueous solution containing copper sulfate pentahydrate. The reaction temperature was controlled to 70°C, and the pH was adjusted to less than 4 to obtain a large amount of precipitate. After adding the raw materials and mixing, the mixture was incubated for 0.5 hours. The solution was thermally filtered, and the filtered cake was washed with clean water until the pH was >4.5. The filtered cake was then dried at 120°C to obtain 19.53 g of solid with a yield of 70%. The sample was dissolved in an aqueous sodium hydroxide solution, and phosphorus nuclear magnetic resonance measurements were performed. 31 As can be seen from the P-NMR spectrum, the molar content of diethylphosphinate ions was 0.80%, ethyl-sec-butylphosphinate ions was 2.76%, ethyl-n-butylphosphinate ions was 49.60%, n-butyl-sec-butylphosphinate ions was 4.48%, and di-n-butylphosphinate ions was 42.36%. The molar fractions of phosphinate ions with the same chemical formula were added together (i.e., the y value was calculated using the sum of ethyl-n-butylphosphinate ions and ethyl-sec-butylphosphinate ions), and the values ​​x=0.01, y=0.52, and z=0.47 were obtained. Due to the different solubility of the different dialkylphosphinate copper salts, the yield in this example was low, and the x, y, and z values ​​of the final hybrid salt differed significantly from the x, y, and z values ​​of other metal hybrid salts obtained from the same phosphorus starting material.

[0127] XRD measurements of the sample revealed that the interlayer distance corresponding to the characteristic peak with the highest relative intensity obtained by XRD was 14.292 angstroms (100%).

[0128] Figure 1 shows the thermal weight loss (TGA) graphs for hybrid salts with different x, y, and z values ​​(Examples 1, 4, and 5) and for aluminum diethylphosphinate and aluminum dibutylphosphinate (Comparative Example 1). As can be seen from the figure, the larger the z value, the lower the thermal stability of the hybrid salt, and the larger the x value, the higher the thermal stability.

[0129] Figure 2a shows the XRD spectra of hybrid salts (Examples 1-5), aluminum dibutylphosphinate (Comparative Example 1), aluminum diethylphosphinate (ADP), and a physical mixed salt of aluminum dibutylphosphinate and aluminum diethylphosphinate, each with different x, y, and z values. Figure 2b is a magnified view of a portion of the strongest absorption peaks in Figure 2a. As can be seen from Figure 2b, the simple physical mixed salt has two independent peaks in the strongest absorption peak region in the XRD spectrum, and their d values ​​are close to those of aluminum diethylphosphinate and aluminum dibutylphosphinate, respectively. The hybrid salt having the composition of formula (I) has only one peak or overlapping peaks, and its d value is basically between the d values ​​of aluminum diethylphosphinate and aluminum dibutylphosphinate. This demonstrates that the dialkylphosphinate hybrid salt having the composition of formula (I) described in the present invention is not a simple mixture of aluminum diethylphosphinate, aluminum ethylbutylphosphinate, and aluminum dibutylphosphinate, but rather a hybrid salt having a structure in which at least two acid ions from among the diethylphosphinate ion, ethylbutylphosphinate ion, and dibutylphosphinate ion are coordinated with the same aluminum atom.

[0130] Example 8 Polyamide PA66, the hybrid salt prepared in Example 1, and a composite antioxidant were mixed in a weight ratio of 79.6:20:0.4 in a closed mixer at a rotation speed of 50 rpm, the temperature was set to 280°C, and after 5 minutes, the mixture was removed, cooled, and dried. The mixture was then filled into a mold, preheated in a flat vulcanizer at 280°C for 10 minutes, held under pressure of 10 MPa for 5 minutes, and then cold-pressed. After cooling, a sample was cut and tested. The flame retardancy grade of the 1.6 mm sample was UL94 V-0.

[0131] Example 9 Polyamide PA6, the hybrid salt prepared in Example 1, and a composite antioxidant were mixed in a weight ratio of 79.6:20:0.4 in a closed mixer at a rotation speed of 50 rpm, the temperature was set to 260°C, and after 5 minutes, the mixture was removed, cooled, and dried. The mixture was then filled into a mold, preheated in a flat vulcanizer at 260°C for 10 minutes, held under pressure of 10 MPa for 5 minutes, and then cold-pressed. After cooling, a sample was cut and tested. The flame retardancy grade of the 1.6 mm sample was UL94 V-0.

[0132] Examples 10-22 Using the hybrid salts prepared in Examples 1-7, samples were prepared and tested in polyamide PA66 and PA6, respectively, according to the instructions in Examples 8 and 9. The results are shown in Table 7.

[0133] Comparative Example 1: Preparation of aluminum dibutylphosphinate 100 g of sodium phosphinate monohydrate was dissolved in 500 g of water and placed in a 1 L stainless steel pressure vessel. The reactor was purged twice with nitrogen gas, evacuated, and then butene was introduced until the pressure stopped rising. The reaction mixture was heated to approximately 90°C, and then a 4% sodium persulfate aqueous solution was added at a constant rate of 10 ml / h to continue introducing butene into the reactor. The amount of butene introduced was measured using a gas flow meter. After 25.5 hours, the pressure of the system stopped decreasing, so the reaction was stopped, the system was cooled to release the pressure, purged with N2, and the materials were discharged to obtain a clear reaction solution. The reaction solution was sampled and measured by nuclear magnetic resonance. 31P-NMR results showed that the molar content of n-butyl-sec-butylphosphinic acid was 10.56%, the molar content of di-n-butylphosphin was 84.92%, the molar content of dibutylphosphinic acid telomer was 3.52%, and the remaining 1.00% consisted of by-products such as butylphosphinic acid, butylphosphonic acid, and phosphorous acid.

[0134] A portion of the above solution (containing 0.3996 moles of phosphorus) was slowly mixed at atmospheric pressure with 44.38 g of a 10% aluminum sulfate 18-hydrate aqueous solution. The reaction temperature was controlled to 70°C, and the pH was adjusted to 3.0 or less to obtain a large amount of precipitate. After adding the raw materials and mixing, the mixture was kept warm for 0.5 hours. Slow thermal filtration was performed, and the filtered cake was washed with clean water until the pH was >4.5. The filtered cake was then dried at 120°C to obtain 67.28 g of a white solid.

[0135] XRD measurements of the sample revealed that the interlayer distance corresponding to the characteristic peak with the highest relative intensity obtained by XRD was 12.770 angstroms (100%).

[0136] Comparative Example 2 Polyamide PA66, aluminum dibutylphosphinate prepared in Comparative Example 1, and a composite antioxidant were mixed in a weight ratio of 79.6:20:0.4 in a closed mixer at a rotation speed of 50 rpm. The temperature was set to 280°C, and after 5 minutes, the mixture was removed, cooled, and dried. It was then filled into a mold, preheated in a flat vulcanizer at 280°C for 10 minutes, held under pressure of 10 MPa for 5 minutes, and then cold-pressed. After cooling, samples were cut and tested. The flame retardancy grade of the 1.6 mm sample was UL94 grade none.

[0137] Comparative Example 3 Polyamide PA6, aluminum dibutylphosphinate prepared in Comparative Example 1, and a composite antioxidant were mixed in a weight ratio of 79.6:20:0.4 in a closed mixer at a rotation speed of 50 rpm. The temperature was set to 260°C, and after 5 minutes, the mixture was removed, cooled, and dried. The mixture was then filled into a mold, preheated in a flat vulcanizer at 260°C for 10 minutes, held under pressure of 10 MPa for 5 minutes, and then cold-pressed. After cooling, a sample was cut and tested. The flame retardancy grade of the 1.6 mm sample was UL-94 V-1.

[0138] Comparative Example 4 Polyamide PA66, aluminum diethylphosphinate, and a composite antioxidant were mixed in a weight ratio of 79.6:20:0.4 in a closed mixer at a rotation speed of 50 rpm, the temperature was set to 280°C, and after 5 minutes, the mixture was removed, cooled, and dried. It was then filled into a mold, preheated in a flat vulcanizer at 280°C for 10 minutes, held under pressure of 10 MPa for 5 minutes, and then cold-pressed. After cooling, a sample was cut and tested. The flame retardancy grade of the 1.6 mm sample was UL94 grade none.

[0139] Comparative Example 5 Polyamide PA6, aluminum diethylphosphinate, and a composite antioxidant were mixed in a weight ratio of 79.6:20:0.4 in a closed mixer at a rotation speed of 50 rpm, the temperature was set to 260°C, and after 5 minutes, the mixture was removed, cooled, and dried. It was then filled into a mold, preheated in a flat vulcanizer at 260°C for 10 minutes, held under pressure of 10 MPa for 5 minutes, and then cold-pressed. After cooling, a sample was cut and tested. The flame retardancy grade of the 1.6 mm sample was UL94 grade none.

[0140] JPEG0007912093000008.jpg62170

[0141] As can be seen from Example 8-22, the flame retardant containing the dialkylphosphinate hybrid salt described in the present invention has excellent flame retardancy for polyamides. The prepared flame retardant PA66 has good toughness in the sample bar and shows no significant degradation. In the combustion test of the flame retardant polyamide, there is no significant smoke. As can be seen from Comparative Examples 2-3, dibutylphosphinate has lower flame retardancy for polyamides than the hybrid salt having the formula (I) structure described in the present invention, and when the flame retardant polyamide burns, it produces a lot of smoke, which is unfavorable for escape. Also, as can be seen from Figure 1, its thermal stability is too low, the prepared flame retardant PA66 is very brittle and shows degradation. As can be seen from Comparative Examples 4-5, aluminum diethylphosphinate has low flame retardancy for polyamides.

[0142] The above description represents only some embodiments of the present invention and does not limit it. While the present invention has been disclosed in the above preferred embodiments, this does not limit it. Modifications or alterations made by those skilled in the art based on the above technical content within the scope of the technical means of the present invention are equivalent to the equivalent embodiments and are all included within the scope of the present invention.

Claims

1. A dialkylphosphinate hybrid salt characterized by being at least one compound selected from compounds having the chemical formula represented by formula (I). (In the formula, M is the central atom, and R １ , R ２ Each is independently C ４ -C １２ Selected from alkyl groups, and R １ , R ２ At least one of them is not an isobutyl group, Diethylphosphinic acid ion, ethyl R １ group phosphinic acid ion, R １ group R ２ group phosphinic acid ions are all ligands, M is selected from metallic elements, and the metallic element is at least one selected from group IIA, IIIIA, IVA, VA metallic elements, transition metallic elements, and lanthanide metallic elements. n is the valence of the metal element M, and n is selected from 2, 3, or 4. Ethyl R １ Base phosphinate ion, diethylphosphinate ion, R １ group R ２ At least two of the phosphinate ions are coordinated to the same central atom M, and one of them has a ligand coordinated to the central atom M that is ethyl R １ It is a phosphinate ion, (0 ≤ x ≤ 0.76, 0.05 ≤ y ≤ 0.76, 0.001 ≤ z ≤ 0.76, and x + y + z = 1.)

2. The aforementioned Group IIA metallic element is selected from Be, Mg, Ca, Sr, and Ba, and is at least one of them. The aforementioned Group IIIA metallic element is Al, The aforementioned IVA group metallic element is Sn, The aforementioned VA group metallic element is Sb, The transition metal element is at least one selected from Fe, Zn, Cu, TI, Zr, and Mn. The aforementioned lanthanide metal element is Ce, The dialkylphosphinic acid hybrid salt according to claim 1, characterized in that 0 ≤ x ≤ 0.76, 0.05 ≤ y ≤ 0.67, and 0.005 ≤ z ≤ 0.

76.

3. The dialkylphosphinic acid hybrid salt according to claim 1, characterized in that 0 ≤ x ≤ 0.70, 0.05 ≤ y ≤ 0.67, and 0.005 ≤ z ≤ 0.

70.

4. The dialkylphosphinic acid hybrid salt according to claim 1, characterized in that 0.1 ≤ x ≤ 0.65, 0.30 ≤ y ≤ 0.67, and 0.01 ≤ z ≤ 0.

50.

5. The dialkylphosphinic acid hybrid salt according to claim 1, characterized in that 0.30 ≤ x ≤ 0.65, 0.30 ≤ y ≤ 0.65, and 0.02 ≤ z ≤ 0.

40.

6. The dialkylphosphinic acid hybrid salt according to claim 1, characterized in that M = Al and n = 3.

7. A method for preparing a dialkylphosphinate hybrid salt according to any one of claims 1 to 6, The process includes the step of reacting mixture A and a raw material containing a metal element M source in an aqueous phase to obtain the dialkylphosphinic acid hybrid salt, The mixture A contains diethylphosphinic acid and / or its alkali metal salt, ethyl R １ Phosphinic acid and / or its alkali metal salt, and R １ group R ２ It contains a phosphinic acid and / or its alkali metal salt, The conditions for reaction I are a temperature of 0–250°C, a pressure of 0.1 MPa–10 MPa, and a time of 0.01–20 h. The preparation method is characterized in that the reaction I is carried out at a pH of 0 to 4.

8. The acquisition of the mixture A is An aqueous solution containing phosphinic acid and / or its alkali metal salt, a free radical initiator, and ethylene and C ４ -C １２ The step includes introducing an olefin, carrying out reaction II, and obtaining the mixture A, The preparation method according to claim 7, characterized in that the conditions for reaction II are a temperature of 0-250°C, a time of 0.01-50h, and a pressure of 0-3 MPa.

9. The phosphinic acid and / or its alkali metal salt, ethylene, C ４ -C １２ The molar ratio of olefins is 1:0.24-1.76:1.76-0.

24. In the aqueous solution, the mass of water is 10-99% of the total mass of the aqueous solution. The preparation method according to claim 8, characterized in that the molar ratio of the free radical initiator to the phosphinic acid and / or its alkali metal salt is 0.001-0.1:

1.

10. The acquisition of the aforementioned mixture A is C ４ -C １２ Introducing olefins, and introducing C ４ -C １２ After the molar ratio of the olefin to the total phosphorus of phosphinic acid and / or its alkali metal salt reaches (y + 2z) / 1 in formula (I), C ４ -C １２ The process includes the step of stopping the introduction of olefins and continuing the reaction by introducing ethylene to obtain the mixture A, or C ４ -C １２ The reaction involves introducing olefins and some ethylenes, and the molar ratio of ethylene to phosphinic acid and / or its alkali metal salts of total phosphorus is less than (2x + y) / 1 in formula (I), and the introduced C ４ -C １２ After the molar ratio of the olefin to the total phosphorus of phosphinic acid and / or its alkali metal salt reaches (y + 2z) / 1 in formula (I), C ４ -C １２ The process includes the step of stopping the introduction of the olefin and continuing to introduce the remaining ethylene to proceed with the reaction, thereby obtaining the mixture A, or A portion of ethylene is introduced into an aqueous solution containing phosphinic acid and / or its alkali metal salt, and a free radical initiator, wherein the molar ratio of the portion of ethylene to the total phosphorus of the phosphinic acid and / or its alkali metal salt is less than or equal to (2x + y) / 1 of formula (I), and after the portion of ethylene has completely reacted, C continues to react. ４ -C １２ The olefin is introduced and the reaction is carried out, and the introduced C ４ -C １２ After the molar ratio of the olefin to the total phosphorus of phosphinic acid and / or its alkali metal salt reaches (y + 2z) / 1 in formula (I), C ４ -C １２ The preparation method according to claim 7, characterized by comprising the step of stopping the introduction of the olefin and continuing to introduce the remaining ethylene to carry out the reaction to obtain the mixture A.

11. The total amount of ethylene and the C ４ -C １２ The preparation method according to claim 10, characterized in that the molar ratio of the total amount of olefin is 0.14-7.33:

1.

12. The metal element M source is at least one selected from salts of the metal element M. The preparation method according to claim 7, characterized in that the salt of the metal element M is at least one selected from nitrate, sulfate, hydrochloride, acetate, and oxide of the metal element M.

13. A flame retardant characterized by being a dialkylphosphinic acid hybrid salt as described in Claim 1.

14. It contains a flame retardant P and a thermoplastic polymer material. The flame retardant P is characterized in that it is at least one selected from the flame retardants described in claim 13.

15. The flame retardant P has a mass content of 1-35% in the flame retardant material. The aforementioned flame-retardant material further contains a functional additive, The functional additive is at least one selected from reinforcing agents, stabilizers, pigments, dyes, dispersants, inorganic fillers, and antioxidants. The reinforcing agent is selected from glass fibers, The functional additive has a mass content of 5-40% in the flame retardant material. The aforementioned flame-retardant material further comprises a flame retardant Q, The aforementioned flame retardant Q is at least one selected from nitrogen-based flame retardants and boron-based flame retardants. The flame retardant Q has a mass content of 0.5-20% in the flame retardant material. The flame retardant material according to claim 14, characterized in that the thermoplastic polymer material is at least one selected from polyamide and polyester.

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