CN116947918A

CN116947918A - Dialkyl phosphinic acid hybrid salt and preparation method and application thereof

Info

Publication number: CN116947918A
Application number: CN202210412718.6A
Authority: CN
Inventors: 姚强; 赵月英; 曹微虹; 唐天波
Original assignee: Ningbo Institute of Material Technology and Engineering of CAS
Current assignee: Ningbo Institute of Material Technology and Engineering of CAS
Priority date: 2022-04-19
Filing date: 2022-04-19
Publication date: 2023-10-27

Abstract

The application discloses a dialkylphosphinic acid hybridization salt, a preparation method and application thereof, wherein the dialkylphosphinic acid hybridization salt is selected from at least one of compounds with chemical formulas shown in a formula (I). The dialkylphosphinic acid hybridization salt with the composition of the formula (I) has the advantages of small addition amount, high flame-retardant efficiency on various high polymer materials and good thermal stability, overcomes the defect of low flame-retardant efficiency on the high polymer materials by diethylphosphinate, overcomes the defects of low thermal stability and large dust of dipropylphosphinate, and can be widely applied to flame retardance on the high polymer materials requiring high-temperature processing.

Description

Dialkyl phosphinic acid hybrid salt and preparation method and application thereof

Technical Field

The application relates to a dialkyl phosphinic acid hybrid salt, a preparation method and application thereof, and belongs to the field of preparation of flame-retardant high polymer materials.

Background

The dialkylphosphinate, in particular to aluminum diethylphosphinate, has been widely used as a halogen-free flame retardant for high polymer materials, the density of the dialkylphosphinate flame retardant products is low, the consumption of the flame retardant is low, and the mechanical property is good, but the existing dialkylphosphinate has limited flame retardant efficiency as the flame retardant, for example, the dialkylphosphinate can be used as the flame retardant for glass fiber reinforced nylon, the flame retardant efficiency is low, and the physical property of the flame retardant high polymer materials can be greatly adversely affected when the flame retardant is used. It has also been reported that the use of aluminum dipropylphosphinate for flame retardance of nylon 6 has a relatively high flame retardance efficiency, but its thermal stability is relatively low, and it begins to degrade and volatilize substantially at 300 c, which is disadvantageous for engineering plastics such as nylon 66, which require high temperature processing.

In addition, when dialkylphosphinic salts are used as flame retardants, in addition to flame retardant properties, it is desirable that the flame retardants have large particle sizes and large densities at the time of preparation and use to reduce filtration time and dust, and that the free flow rates of the two in the loading barrel are not uniform due to excessively large density differences when mixed with polymeric materials, thereby causing poor uniformity of the distribution of the flame retardants in the flame retardant materials.

Therefore, obtaining a flame retardant with good flame retardancy, high thermal stability, and good processability is a great challenge in the industry. Now, surprisingly, dialkylphosphinic acid hybrid salts having specific compositions meet the above requirements well.

Disclosure of Invention

In order to solve the technical problems, the application provides the dialkyl phosphinic acid hybrid salt, and the preparation method and the application thereof, wherein the dialkyl phosphinic acid hybrid salt has the dialkyl phosphinic acid hybrid salt composed of the formula (I), and has the advantages of small addition amount, high flame retardant efficiency on various high polymer materials, good thermal stability, capability of meeting the processing requirements of engineering plastics requiring high temperature, large particles and low dust.

According to a first aspect of the present application, there is provided a dialkylphosphinic acid hybridization salt selected from at least one of compounds having a chemical formula represented by the formula (i):

Wherein M is a central atom; r, R ₁ 、R ₂ Are independently selected from any one of n-propyl and isopropyl; diethyl phosphinate ion, ethyl propyl phosphinate ion and dipropyl phosphinate ion are ligands; and at least two of diethyl phosphinate ion, ethyl propyl phosphinate ion and dipropyl phosphinate ion are paired with the same metal atom, and one of the ligands must be ethyl propyl phosphinate ion;

m is selected from metal elements; the metal element is at least one selected from group IIA, IIIA, IVA, VA metal element, transition metal element and lanthanide series metal element;

n is the valence of the metal M; n is selected from 2,3 or 4;

x is more than or equal to 0 and less than or equal to 0.80; y is more than or equal to 0.05 and less than or equal to 0.7; 0.ltoreq.z.ltoreq.0.95, and x+y+z=1.

Specifically, the propyl in the ethylpropylphosphinate ion and the dipropylphosphinate ion is n-propyl or isopropyl.

In the embodiment of the application, in the formula (I), if x is more than 0.80, the flame retardant property is poor. If z is greater than 0.95, the particles are small during preparation, the filtration is slow, the dust is large during use, and the thermal stability is reduced, so that the flame-retardant polymer material is unfavorable in preparation and physical properties. y is larger than 0.7, the preparation cost is high, the economy is poor, and the preparation and physical properties of the flame-retardant polymer material are unfavorable.

Alternatively, the lower limit of x is independently selected from 0, 0.03, 0.05, 0.10, 0.15; the upper limit is independently selected from 0.80, 0.75, 0.70, 0.65, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30.

Alternatively, the lower limit of y is independently selected from 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40; the upper limit is independently selected from 0.70, 0.65, 0.60, 0.55, 0.50, 0.45.

Alternatively, the lower limit of z is independently selected from 0, 0.001, 0.005, 0.01, 0.02, 0.05, 0.08; the upper limit is independently selected from 0.95, 0.9, 0.85, 0.80, 0.75, 0.7, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.3, 0.25, 0.2, 0.15, 0.10.

Optionally, the group iia metal element is selected from at least one of Be, mg, ca, sr, ba;

the III A metal element is Al;

the group IVA metal element is Sn;

the group VA metal element is Sb;

the transition metal element is selected from at least one of Fe, zn, cu, ti, zr, mn;

the lanthanide metal element is Ce.

Optionally, the metal element is selected from at least one of Al, zn, ca, fe.

Optionally, the metal element is Al, n=3.

Optionally, 0.ltoreq.x.ltoreq.0.80; y is more than or equal to 0.05 and less than or equal to 0.70; z is more than or equal to 0.005 and less than or equal to 0.92.

Optionally, 0.ltoreq.x.ltoreq.0.66; y is more than or equal to 0.30 and less than or equal to 0.70; z is more than or equal to 0.01 and less than or equal to 0.60.

Optionally, 0.ltoreq.x.ltoreq.0.30; y is more than or equal to 0.35 and less than or equal to 0.70; z is more than or equal to 0.05 and less than or equal to 0.60.

In the embodiment of the application, the larger the z value is, the earlier the thermal weight loss of the dialkylphosphinic acid hybrid salt is.

The dialkylphosphinic acid hybrid salt of the present application is not a simple physical mixture of different dialkylphosphinic salts, for example, a mixture of aluminum diethylphosphinate and aluminum ethylpropylphosphinate, but a hybrid salt comprising at least 2 ions of diethylphosphinate ion, ethylpropylphosphinate ion, dipropylphosphinate ion coordinated to the same aluminum atom, and one ligand of the hybrid salt is ethylpropylphosphinate ion. The X-ray diffraction spectra (XRD) of these hybrid salts are very different from those of the simple physically mixed salts of dialkylphosphinic salts. The dialkylphosphinic acid hybrid salt having the composition of formula (I) exhibits a single peak in the XRD spectrum at the strongest absorption peak region. And the largest peak also shows a different interplanar spacing than aluminum diethylphosphinate and aluminum dipropylphosphinate. The largest peak of aluminum diethylphosphinate shows a interplanar spacing d= 9.663, aluminum dipropylphosphinate d= 11.079, and the interplanar spacing d of the dialkylphosphinic acid hybrid salt having the formula (i) is substantially between the two. However, the physically mixed salts obtained by simple mixing of aluminum diethylphosphinate and aluminum dipropylphosphinate exhibit 2 completely independent peaks in the XRD pattern, and their d values are close to those of aluminum diethylphosphinate and aluminum dipropylphosphinate, respectively.

In the examples of the present application, after a dialkylphosphinic acid hybrid salt having the composition of formula (I) and aluminum diethylphosphinate or aluminum dipropylphosphinate were simply physically mixed, 2 independent peaks also appeared in the strongest absorption peak region in their XRD patterns. These results strongly illustrate that the dialkylphosphinic acid hybrid salts of the composition of formula (I) obtained according to the present application are not simply mixtures of aluminum diethylphosphinate, aluminum ethylpropylphosphinate, aluminum dipropylphosphinate, but rather comprise structures in which at least two of the ions diethylphosphinate, ethylpropylphosphinate, dipropylphosphinate are paired with the same aluminum atom.

In the embodiment of the application, under the same dosage, the pure aluminum dipropylphosphinate has good flame retardant effect, but has low thermal stability, and is difficult to meet the requirement of high-molecular materials which need high-temperature processing. And the pure aluminum dipropyl phosphinate powder is large in dust and difficult to operate. And because the pure aluminum dipropyl phosphinate particles are fine, when the aluminum dipropyl phosphinate is mixed with a high polymer material, local layering is easy to cause, and the mixing uniformity is poor. In contrast, the dialkylphosphinic acid hybrid salt with the composition of the formula (I) has high thermal stability, large particles and no dust, and has similar flow speed with high molecular particles in a feeding barrel and good mixing uniformity.

In the embodiment of the application, under the same dosage, the flame retardant effect of the pure diethyl phosphinate is poor and far less good than that of the dialkyl phosphinate hybridized salt with the composition shown in the formula (I).

According to a second aspect of the present application, there is provided a process for preparing the above dialkylphosphinic acid hybridization salt, the process comprising:

carrying out reaction I on a material containing the mixture A and a metal element M source in a water phase to obtain the dialkylphosphinic acid hybrid salt;

the mixture A comprises diethyl phosphinic acid and/or alkali metal salt thereof, ethyl propyl phosphinic acid and/or alkali metal salt thereof and dipropyl phosphinic acid and/or alkali metal salt thereof.

Optionally, the metal element is Al, and the pH value of the reaction I is 0-4; preferably 1 to 3.5; more preferably 2.3 to 3.3.

Specifically, reaction I above has a pH that is too low to precipitate. Too high a pH will produce metal ion hydroxides, introducing impurities.

Optionally, the molar ratio of diethyl phosphinic acid and/or its alkali metal salt, ethyl propyl phosphinic acid and/or its alkali metal salt, dipropyl phosphinic acid and/or its alkali metal salt to the source of metal element M is close to x: y: z: q, said propyl being selected from n-propyl, isopropyl, wherein q = 1/n.

Due to the difference in M, the solubility of the hybrid salt in water is not the same. For the high solubility hybrid salt, the values of x, y, z in the solution for diethylphosphinic acid and/or its alkali metal salt, ethylpropylphosphinic acid and/or its alkali metal salt, dipropylphosphinic acid and/or its alkali metal salt and the hybrid salt will vary, and thus the molar ratio to the M source will also vary. In addition, the molar proportions of the reactants x, y, z and M may also exceed the theoretical calculated values in order to obtain a greater M-containing precipitate.

In the actual operation process, the actual values of x, y, z and q can be judged through phosphorus nuclear magnetism.

Optionally, the molar ratio of diethylphosphinic acid and/or alkali metal salt thereof, ethylpropylphosphinic acid and/or alkali metal salt thereof to dipropylphosphinic acid and/or alkali metal salt thereof in the mixture A is the same or substantially the same as the x, y, z ratio in formula (I).

Alternatively, the conditions of reaction I are: the temperature is 0-250 ℃; the pressure is 0.1MPa-10MPa; the time is 0.1-20h.

Optionally, the obtaining of the mixture a comprises the steps of:

introducing ethylene and propylene into an aqueous solution containing phosphinic acid and/or alkali metal salt thereof and a free radical initiator, and reacting II to obtain the mixture A.

Optionally, the molar ratio of the phosphinic acid and/or alkali metal salt thereof, ethylene and propylene is 1:0.05-1.8:0.2-1.95.

In practice, the consumption of olefins is higher than the theoretical ratio due to the presence of side reactions, such as long chain dialkylphosphinates obtained by polymerization of ethylene and/or propylene.

Alternatively, the molar ratio of phosphinic acid and/or alkali metal salt thereof, ethylene, propylene is the same or close to the x, y, z values in formula (I). Since y has a maximum value of less than 1 during the reaction of hypophosphorous acid or its alkali metal salt with ethylene or propylene, x or z increases after reaching this maximum value, and y cannot reach 1. If y=1 is to be produced, the reaction intermediate product needs to be separated and purified to remove diethyl phosphinic acid and/or dipropyl phosphinic acid or salts thereof, which is disadvantageous in economical efficiency.

Specifically, in reaction II, the order of addition of ethylene and propylene may be interchanged, may be added simultaneously, or may be partially added first.

Alternatively, in reaction II, hypophosphorous acid and/or its alkali metal salt is reacted with propylene to obtain the corresponding y, z value and then reacted substantially or completely with ethylene. By substantially completely is meant that the sum of the phosphorus content of the ethyl phosphinate, propyl phosphinate, phosphinate in the reaction mixture is less than 5 mole% of the sum of all the phosphorus content in the reaction mixture.

Optionally, in the aqueous solution, the mass of the water is 10-99% of the total mass of the aqueous solution.

Specifically, in the aqueous solution, too little water is used, the salting-out effect causes low solubility of olefin in water, the reaction speed is slow, too much water is used, and the utilization rate of the reaction kettle is reduced.

Optionally, in the aqueous solution, the mass of the water is 20-95% of the total mass of the aqueous solution.

Optionally, in the aqueous solution, the mass of the water is 45-92% of the total mass of the aqueous solution.

Optionally, in the aqueous solution, the mass of the water is 50-90% of the total mass of the aqueous solution.

Optionally, in the aqueous solution, the mass of the water is 55-90% of the total mass of the aqueous solution.

Alternatively, the conditions of reaction II are: the temperature is 0-250 ℃; the time is 0.01-50h; the pressure is 0-3MPa.

Specifically, the reaction II has low temperature, low reaction speed and high temperature, and hypophosphite is easy to decompose.

Alternatively, the temperature of reaction II is 10-200 ℃.

Specifically, the pressure of the reaction II is higher than 3MPa, the requirement on reaction equipment is increased, and the operation is difficult.

Alternatively, the pressure of reaction II is 0.2-1.5MPa.

Optionally, the molar ratio of the free radical initiator to the hypophosphorous acid and/or its alkali metal salt is 0.001-0.1:1.

Optionally, the free radical initiator is at least one selected from azo initiator, peroxide initiator and photoinitiator. Wherein the addition amount of the free radical initiator can be determined according to actual needs.

Optionally, the azo initiator is selected from cationic and/or non-cationic azo initiators, including one or more of azobisisobutyronitrile, 4 '-azobis (4-cyanovaleric acid), 2' -azobis (2-methylbutyronitrile), 2 '-azobis (2-amidinopropane) dihydrochloride, 2' -azobispropylamidine dihydrochloride.

Alternatively, the peroxide-based initiator is preferably an inorganic peroxide and an organic peroxide radical initiator, and particularly preferably one or more of hydrogen peroxide, ammonia persulfate, potassium persulfate, sodium percarbonate, benzoyl peroxide, di-t-butyl peroxide, t-butyl perbenzoate, peracetic acid.

Preferably, the free radical initiator is a peroxide species. Particularly preferably, the free radical initiator is selected from one of ammonium persulfate, potassium persulfate, sodium persulfate.

Optionally, the molar ratio of the free radical initiator to the phosphinic acid and/or alkali metal salt thereof is from 0.003 to 0.05:1.

Optionally, the obtaining of the mixture a comprises the steps of:

propylene is introduced into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator for reaction, after the molar ratio of the introduced propylene to the total phosphorus of the hypophosphorous acid and/or alkali metal salt thereof reaches (y+2z)/1 in the formula (I), the introduced propylene is stopped, and then ethylene reaction is continued, so that the mixture A is obtained.

Optionally, the obtaining of the mixture a comprises the steps of:

propylene is introduced into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator, and after the propylene is reacted completely or nearly completely, ethylene is continuously introduced for reaction, so that the mixture A is obtained.

Alternatively, hypophosphorous acid and/or its alkali metal salt is reacted with propylene to obtain monopropyl phosphinic acid or its alkali metal salt having or substantially close to the value y, and z is controlled to 0.95 or less, then the addition of propylene is stopped, ethylene is added instead, and the reaction is continued in the presence of an initiator, followed by reaction with the desired metal salt to obtain a flame retardant having the formula (I).

Optionally, the obtaining of the mixture a comprises the steps of:

propylene and part of ethylene are introduced into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator for reaction, the total phosphorus mole ratio of ethylene to hypophosphorous acid and/or alkali metal salt thereof is smaller than (2x+y)/1 in the formula (I), after the total phosphorus mole ratio of propylene to hypophosphorous acid and/or alkali metal salt thereof reaches (y+2z)/1 in the formula (I), the introduction of propylene is stopped, and the reaction of the rest of ethylene is continued, so that the mixture A is obtained.

Optionally, the obtaining of the mixture a comprises the steps of:

introducing propylene and part of ethylene into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator, and continuing to introduce the rest part of ethylene for reaction after the propylene and part of ethylene react completely or nearly completely to obtain a mixture A;

the molar ratio of the total amount of ethylene to the propylene is 0.026-9:1.

Optionally, the obtaining of the mixture a comprises the steps of:

and (3) introducing part of ethylene into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator, wherein the mole ratio of the part of ethylene to the hypophosphorous acid and/or alkali metal salt thereof total phosphorus is (2x+y)/1 in the formula (I), continuing introducing propylene for reaction after the part of ethylene is reacted completely, and stopping introducing propylene for reaction after the mole ratio of the introduced propylene to the total phosphorus in the initial hypophosphorous acid and/or alkali metal salt thereof reaches (y+2z)/1 in the formula (I), thereby obtaining the mixture A.

Optionally, the obtaining of the mixture a comprises the steps of:

introducing part of ethylene into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator, continuously introducing propylene for reaction after the part of ethylene is reacted completely or nearly completely, and introducing the rest part of ethylene for reaction after the propylene is reacted completely or nearly completely to obtain a mixture A;

the molar ratio of the total amount of ethylene to the propylene is 0.026-9:1.

Optionally, the metal element M source is selected from at least one of metal element M salts.

Optionally, the metal element M salt is selected from at least one of nitrate, sulfate, hydrochloride, acetate, and oxide of the metal element M.

Optionally, hypophosphorous acid and/or alkali metal salt thereof and propylene and partial ethylene are simultaneously reacted in the presence of a free radical initiator, the amounts of propylene and ethylene are controlled, the mole percent of propylphosphinic acid or alkali metal salt thereof in the reaction system is close to y value, the mole percent of dipropylphosphinic acid or alkali metal salt thereof is close to z value, and z is less than or equal to 0.95, the addition of propylene is stopped, the addition of the rest ethylene is continued, the reaction is continued to the end in the presence of the initiator, and then the reaction is carried out with a required metal salt, so as to obtain the dialkylphosphinic acid hybridization salt with the formula (I).

Optionally, the obtaining of the mixture a comprises the steps of:

introducing ethylene into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator, controlling the amount of ethylene, stopping introducing ethylene after the molar ratio of the introduced ethylene to the total phosphorus of the hypophosphorous acid and/or alkali metal salt thereof reaches (y+2x)/1 in the formula (I), continuously adding propylene, and continuously reacting in the presence of the initiator until the reaction is finished, thus obtaining the mixture A.

Specifically, after the reaction II is finished, the next reaction is directly carried out without separating diethyl phosphinic acid, ethyl propyl phosphinic acid, dipropyl phosphinic acid or a mixture of alkali metals thereof.

According to a third aspect of the present application there is also provided a flame retardant comprising at least one of the above dialkylphosphinic acid hybrid salts.

Optionally, the flame retardant further contains at least one selected from the group consisting of phosphate ions, phosphite ions, alkylphosphonate ions and alkylphosphinate ions, and the molar content of these phosphate ions 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 element contained therein.

According to a fourth aspect of the present application, there is provided a flame retardant material comprising a flame retardant P and a thermoplastic polymer material;

the flame retardant P is at least one selected from the dialkylphosphinic acid hybridization salt and the flame retardant.

Optionally, the mass content of the flame retardant P in the flame retardant material is 1-35%.

Optionally, the flame retardant material comprises 1-35wt% of flame retardant P and 65-99wt% of thermoplastic polymer material.

The thermoplastic polymer material of the present application is a plastic having heat softening and cooling hardening properties.

Specifically, the amount of the flame retardant P depends on the thermoplastic polymer material.

Optionally, the mass content of the flame retardant P in the flame retardant material is 3-20%.

Optionally, in the flame retardant material, functional additives are further included;

the functional additive is at least one selected from reinforcing agents, anti-dripping agents, stabilizing agents, pigments, dyes, char-forming catalysts, dispersing agents, nucleating agents, inorganic fillers and antioxidants.

Optionally, the reinforcing agent is selected from glass fibers.

Optionally, the anti-drip agent is selected from Teflon.

Optionally, the inorganic filler is selected from at least one of mica stone, calcium carbonate, calcium oxide and silica.

Optionally, the functional additive is present in the flame retardant material in an amount of 5 to 40% by mass.

Optionally, in the flame retardant material, a flame retardant Q is further included;

the flame retardant Q is at least one selected from nitrogen flame retardants and boron flame retardants.

Optionally, 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.

Optionally, the mass content of the flame retardant Q in the flame retardant material is 0.5-20%.

Optionally, the thermoplastic polymer material is at least one selected from polyamide and polyester.

Optionally, the polyamide is selected from at least one of aliphatic polyamide, aromatic polyamide, semi-aromatic polyamide, and copolymer of semi-aromatic polyamide and aliphatic polyamide.

Polyamides, also known as chinlon or nylon, are a generic term for polymers containing-NH-C (O) -amide groups 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, in accordance with common general knowledge in the art. Polyamides are generally classified into aliphatic polyamides, aromatic polyamides and semiaromatic polyamides according to the composition of the main chain thereof. Semi-aromatic polyamide means that at least one of its synthetic monomers contains aromatic groups in its structure.

Optionally, the aliphatic polyamide is selected from one or a mixture of more than one of a copolymer of polyamide 6 and polyamide 66, polyamide 6 and polyamide 66.

Alternatively, the semi-aromatic polyamide can be prepared from any one or more aromatic dicarboxylic acids and any one or more aliphatic diamines, and also can be prepared from any one or more aromatic diamines and any one or more aliphatic dicarboxylic acids. One or more of dicarboxylic acid, diamine, lactam and amino acid can be optionally added into the system to prepare the polyamide copolymer with corresponding properties. The added dicarboxylic acid is aromatic dicarboxylic acid and/or aliphatic dicarboxylic acid; the diamine added is aromatic diamine and/or aliphatic diamine; the added lactam may be an aliphatic or aromatic lactam. The amino acid added may be an aromatic or aliphatic amino acid.

Alternatively, the semiaromatic polyamide is made from one or more aromatic dicarboxylic acids, optionally selected from terephthalic acid, isophthalic acid and naphthalene dicarboxylic acid, and one or more aliphatic diamines, selected from Ren Xuanzi butanediamine, hexamethylenediamine, octanediamine, decanediamine and 2-methylpentanediamine.

Alternatively, the semiaromatic polyamide is made from aliphatic diamines, aromatic dicarboxylic acids and aliphatic dicarboxylic acids.

Optionally, the semi-aromatic polyamide is prepared from aliphatic diamine and aromatic dicarboxylic acid; optionally, an aliphatic dicarboxylic acid may be added thereto, wherein the mole fraction of the aliphatic dicarboxylic acid is 0-45% of the total amount of dicarboxylic acids, i.e., the mole number of aliphatic dicarboxylic acid/(mole number of aliphatic dicarboxylic acid+mole number of aromatic dicarboxylic acid) =0-45%.

Optionally, the aromatic dicarboxylic acid is any one or more selected from terephthalic acid, isophthalic acid and naphthalene dicarboxylic acid; the aliphatic diamine is selected from one or more of butanediamine, hexanediamine, octanediamine, decanediamine and 2-methylpentanediamine; the aliphatic dicarboxylic acid is one or more selected from adipic acid, succinic acid, sebacic acid and suberic acid.

Optionally, the polyamide is selected from one or more of poly (hexamethylene terephthalamide) (abbreviated as PA 6T), poly (hexamethylene isophthalamide) (abbreviated as PA 6I), a terephthalic acid/hexamethylene diamine/caprolactam copolymer (abbreviated as PA 6T/6), a terephthalic acid/hexamethylene diamine/adipic acid copolymer (abbreviated as PA 6T/66), a terephthalic acid/hexamethylene diamine/adipic acid/isophthalic acid copolymer (abbreviated as PA 6T/6I/66), poly (hexamethylene terephthalamide) (abbreviated as PA 9T), poly (hexamethylene terephthalamide) (abbreviated as PA 10T), poly (hexamethylene terephthalamide) (abbreviated as PA 12T), poly (m-xylylene adipamide) (abbreviated as MXD 6), a terephthalic acid/hexamethylene diamine/2-methylpentanediamine copolymer (abbreviated as PA 6T/2-MPMDT), terephthalic acid/2, 4 trimethylhexamethylene diamine/2, 4-trimethylhexamethylene diamine or a copolymer.

Optionally, the aliphatic polyamide is selected from at least one of polyamide 6, polyamide 66, and a copolymer of polyamide 6 and polyamide 66.

Optionally, the semiaromatic polyamide is selected from polyphthalamides (PPA).

Optionally, the polyester is selected from polybutylene terephthalate (PBT).

In embodiments of the present invention, the values of x, y, z in formula (i) are independent of the amount of other phosphorus-containing impurities, x+y+z=1, and x+z > 0. The flame retardant having the composition of formula (I) may contain trace amounts of other phosphorus-containing ions. Some trace amounts of phosphate ions, phosphite ions, alkylphosphonate ions, alkylphosphinate ions may be present in the flame retardant due to impurities contained in the raw material or impurities generated by the synthesis process. Some oligomeric products polymerized from ethylene and or propylene, such as ethyl n-butylphosphinate ion, ethylhexyl phosphinate ion, butyl butylphosphinate ion, butyl hexylphosphinate ion, propyl hexylphosphinate ion, may also be present as impurities in flame retardants having the composition of formula (I). But as long as the total amount of these other phosphate-containing acid ions does not exceed 5 mole% of the total phosphorus, and does not affect the proper operation of the flame retardant composition of formula (I).

In embodiments of the application, the x, y, z ratio of formula (I) may be determined by either alkaline hydrolysis or acidolysis of the flame retardant ³¹ P-NMR (nuclear magnetic resonance). Diethyl phosphinate, ethyl n-propyl phosphinate, ethyl isopropyl phosphinate, di-n-propyl phosphinate, n-propyl isopropyl phosphinate have different properties ³¹ Chemical shift of P in ³¹ The P-NMR spectrum showed five peaks independently, the peak areas of which correspond to the molar concentrations of five dialkylphosphinate ions, respectively. In some cases, long chain dialkylphosphinate ions are present in small amounts and are chemically displaced close to the corresponding dialkylphosphinate ions, and thus, are incorporated into the corresponding dialkylphosphinate ions when integrated. From this ratio of peak areas, the values of x, y and z can be conveniently calculated, for example, the molar concentration of diethyl phosphinate corresponds to x, the sum of the molar concentrations of ethyl n-propyl phosphinate and ethyl isopropyl phosphinate (abbreviated as the molar concentration of ethyl propyl phosphinate) corresponds to y, the sum of the molar concentrations of di-n-propyl phosphinate and n-propyl isopropyl phosphinate (abbreviated as the molar concentration of dipropyl phosphinate) corresponds to z, and the ratio of the three is the values of x, y and z.

The application has the beneficial effects that:

(1) The dialkylphosphinic acid hybridization salt with the composition of the formula (I) provided by the application has the advantages of small addition amount, easy filtration of large-particle-size products, less dust, high thermal stability, high flame retardant efficiency on high polymer materials and good economy. The method not only overcomes the defect of low flame retardant efficiency of diethyl phosphinate to high polymer materials, but also overcomes the defect of low thermal stability and large dust of dipropyl phosphinate, and can be widely applied to flame retardance of high polymer materials needing high-temperature processing;

(2) The application provides a preparation method of dialkyl phosphinic acid hybrid salt, which avoids the defect that different dialkyl phosphinic acids are required to be prepared independently, uses water as a reaction solvent, and has good environmental protection. The raw materials are easy to obtain, and the economy is high.

Drawings

FIG. 1 is a graph of thermal weight loss of dialkylphosphinic acid hybrid salts and aluminum diethylphosphinate and aluminum dipropylphosphinate having different x, y, z values;

FIGS. 2a, 2b are XRD plots of dialkylphosphinic acid hybrid salts, aluminum diethylphosphinate, and aluminum dipropylphosphinate having different x, y, z values, where FIG. 2b is a partial magnified view of the strongest absorption peak of FIG. 2 a;

FIG. 3 is a graph showing the results of dialkylphosphinic acid hybridization of saline-alkali solution in example 7 ³¹ P-NMR spectrum.

Detailed Description

The present application is described in detail below with reference to examples, but the present application is not limited to these examples.

Unless otherwise indicated, all starting materials in the examples of the present application were purchased commercially.

The raw materials used in the examples are as follows:

PA66 (also known as polyamide 66 or nylon 66): dupont Zytel 70g35 HSL NC010, 35% glass fiber by weight;

PA6 (also known as polyamide 6 or nylon 6) dupont Zytel 73G30L nc010, 30% glass fiber content by weight;

ADP-aluminum diethylphosphinate, exolit OP1230, a company of Clariant, germany;

antioxidant 1010: pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], shanghai Michlin Biochemical technology Co.

Antioxidant 168: tris [2, 4-di-t-butylphenyl ] phosphite, strem, USA.

And (3) compounding an antioxidant: antioxidant 1010 (tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] pentaerythritol) and antioxidant 168 (tris [2, 4-di-tert-butylphenyl ] phosphite) were mixed in a 1:1 weight ratio.

Combustion test standard: GB/T2408-2008 standard;

nuclear Magnetic Resonance (NMR) test: the apparatus used was of the type AVANCE III MHz, bruker, germany.

Nuclear magnetic resonance phosphorus spectrum [ ] ³¹ P-NMR) test method: pre-delay d1=10 seconds, scan 32 times, and use the ratio of peak area as the ratio of moles of diethyl phosphinate, ethyl propyl phosphinate, dipropyl phosphinate ion.

The instrument model used for X-ray diffraction (XRD) testing: d8 ADVANCE DAVINCI Bruker, germany.

The type of the instrument used for TGA thermal weightlessness treatment: q500, america TA, nitrogen atmosphere, heating rate 10 ℃/min.

Particle size D50 New Patag laser particle sizer Heloise-oasis HELOS (H3938), germany, dry test.

R, R in the present application ₁ 、R ₂ All are selected from any one of n-propyl and isopropyl, and 2 different propyl groups can fall in the same unit structure shown by y or z. That is, in the unit structure shown in the same y, R is both n-propyl and isopropyl, but the specific R value cannot be defined in detail in the specific embodiment because it is not the only value. It is not necessary to define how much of each of the n-propyl and isopropyl groups is required in the unit structure shown in each y or z, only that the total amount meets the criteria. The applicant gives a specific description in table 1 by way of example: for example, the subscript of the formula of the double mixture corresponds to y, which comprises double mixture 1 (r=isopropyl), and double mixture 2 (r=n-propyl).

Example 1

Preparation of a hybrid salt having the composition of formula (i), wherein x=0, y=0.086, z=0.914, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise any more. The reaction solution was heated to about 90℃and then stirred into a sodium persulfate aqueous solution having a concentration of 4% by mass at a constant speed of 10ml/h under a pressure of 0.75MPa,and continuously introducing propylene into the reaction kettle, and metering the introducing amount of olefin through a gas flowmeter. After 9 hours, the propylene was stopped and ethylene was started. After 16 hours, the pressure of the reaction kettle is not reduced any more, the temperature is reduced, the pressure is relieved, and N is reduced ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 1:

TABLE 1

Note that: double addition product: a product of the addition of 2P-H bonds on the hypophosphite to an olefinic double bond; monoaddition products: a product of 1P-H bond on hypophosphite added to olefinic double bond; double mixing 1: ethyl isopropyl phosphinate ion (r=isopropyl); double mixing 2: ethyl n-propyl phosphinate ion (r=n-propyl); bis-B: diethyl phosphinate ions; bipropy: n-propyl isopropyl phosphinate ion (R) ₁ ≠R ₂ N-propyl and isopropyl) plus di-n-propylphosphinate (R) ₁ ＝R ₂ =n-propyl) ions; single B: monoethyl phosphinate ion; monopropyl 1: monoisopropyl phosphinate ion; monopropyl 2: mono-n-propyl phosphinate ions; single oxidation: the sum of ethyl phosphonate ions plus propyl phosphonate ions. The following is the same.

551.94 g (0.6 mol phosphorus) of the above partial solution was mixed with a 10% by mass aqueous solution containing 66.64 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 93 g of a white solid. And (3) dissolving the sample in a sodium hydroxide aqueous solution to obtain 8.6mol% of ethyl propyl phosphinate ions, 91.0mol% of dipropyl phosphinate ions and 0.4% of propyl phosphinate ions by using a phosphorus nuclear magnet. Normalization yields x=0, y=0.086, z=0.914.

Performing sample processingParticle size test, D ₅₀ ＝53.71μm。

XRD testing of the sample, wherein the layer spacing corresponding to the characteristic peak with highest relative intensity measured by the obtained XRD is (100％)。

Example 2 preparation of a hybrid salt having the composition of formula (i) wherein x=0, y=0.192, z=0.808, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise any more. The reaction mixture was heated to about 90℃and the pressure gauge was set at 0.75MPa, and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and propylene was continuously fed into the reaction vessel, whereby the feed amount of olefin was measured by the gas flow meter. After 8.5 hours, the propylene feed was stopped and ethylene feed was started. After 15.5 hours, the pressure of the reaction kettle is not reduced any more, and the temperature and the pressure are reduced, and N is removed ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 2:

TABLE 2

559.8 g (0.6 mol phosphorus) of the above partial solution was mixed with a 10% by mass aqueous solution containing 66.64 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 90 g of a white solid in 98.4% yield. The sample is dissolved in sodium hydroxide aqueous solution to be made into nuclear magnetism, and the nuclear magnetism can be obtained from a phosphorus spectrum: the sum of dipropylphosphinate ions was 80.8mol% and the sum of ethylpropylphosphinate ions was 19.2mol%. Thus x=0, y=0.192, z=0.808.

Particle size test of sample, D ₅₀ ＝24.66μm。

XRD testing of the sample, wherein the layer spacing corresponding to the characteristic peak with highest relative intensity measured by the obtained XRD is(100％)。

Example 3 preparation of a hybrid salt having the composition of formula (i) wherein x=0, y=0.412, z=0.588, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise any more. The reaction solution was heated to about 90℃and the pressure gauge showed about 0.70MPa, and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and propylene was continuously fed into the reaction vessel, whereby the feed amount of olefin was measured by the gas flow meter. After 6 hours, the propylene was stopped and ethylene was started to be fed, and the pressure was maintained at 0.8MPa. After 17.5 hours, the pressure of the reaction kettle is not reduced any more, and the temperature and the pressure are reduced, and N is removed ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 3:

TABLE 3 Table 3

559.94 g (0.6 mol phosphorus) of the above partial solution was mixed with a 10% by mass aqueous solution containing 66.64 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 87.3 g of a white solid in 98% yield. The sample is dissolved in sodium hydroxide aqueous solution to be made into nuclear magnetism, and the nuclear magnetism can be obtained from a phosphorus spectrum: the total amount of dipropylphosphinate ions is 58.3mol%, the total amount of ethylpropylphosphinate ions is 40.9mol%, and the rest 0.8mol% is other phosphorus-containing impurities including monopropylphosphinate ions, propylphosphonate ions, etc. Normalization yields x=0, y=0.412, and z=0.588.

Particle size test of sample, D ₅₀ ＝27.69μm。

Example 4 preparation of a hybrid salt having the composition of formula (i) wherein x=0.033, y=0.610, z=0.357, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise any more. The reaction solution was heated to about 90℃and the pressure gauge showed about 0.70MPa, and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and propylene was continuously fed into the reaction vessel, whereby the feed amount of olefin was measured by the gas flow meter. After 5.5 hours, the propylene was stopped and ethylene was started to be fed, and the pressure was maintained at 0.8MPa. After 16 hours, the pressure of the reaction kettle is not reduced any more, the temperature is reduced, the pressure is relieved, and N is reduced ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 4:

TABLE 4 Table 4

536.33 g (0.6 mol phosphorus) of the above partial solution was mixed with a 10% by mass aqueous solution containing 66.64 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 86.1 g of a white solid in 98% yield. Dissolving a sample in a sodium hydroxide aqueous solution to prepare a nuclear magnetism, and obtaining the nuclear magnetism from a phosphorus spectrum: diethyl phosphinate ion 3.3mol%, dipropyl phosphinate ion total 35.7mol%, ethyl propyl phosphinate ion total 61.0mol% gives x=0.033, y=0.610, z=0.357.

Particle size test of sample, D ₅₀ ＝29.98μm。

Example 5 preparation of a hybrid salt having the composition of formula (i) wherein x=0.082, y=0.694, z=0.224, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise any more. The reaction solution was heated to about 90℃and the pressure gauge showed about 0.70MPa, and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and propylene was continuously fed into the reaction vessel, whereby the feed amount of olefin was measured by the gas flow meter. After 5 hours, the propylene was stopped and ethylene was started to be fed, and the pressure was maintained at 0.8MPa. After 15 hours, the pressure of the reaction kettle is not reduced, the temperature is reduced, the pressure is relieved, and N is added ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 5:

TABLE 5

548.44 g (0.6 mol phosphorus) of the above partial solution was mixed with a 10% by mass aqueous solution containing 66.64 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 84 g of a white solid in 99% yield. Dissolving a sample in a sodium hydroxide aqueous solution to prepare a nuclear magnetism, and obtaining the nuclear magnetism from a phosphorus spectrum: 8.1mol% of diethylphosphinate ions, 22.2mol% of dipropylphosphinate ions and 68.5mol% of ethylpropylphosphinate ions, and 1.3mol% of other phosphorus-containing impurities such as monopropylphosphinate ions. After normalization, x=0.082, y=0.694, and z=0.224 are obtained.

Particle size test of sample, D ₅₀ ＝49.26μm。

Example 6 preparation of a hybrid salt having the composition of formula (i) wherein x=0.251, y=0.647, z=0.102, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise any more. The reaction solution was heated to about 90℃and the pressure gauge showed about 0.70MPa, and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and propylene was continuously fed into the reaction vessel, whereby the feed amount of olefin was measured by the gas flow meter. After 4.5 hours, the propylene was stopped and ethylene was started to be fed, and the pressure was maintained at 0.8MPa. After 15.5 hours, the pressure of the reaction kettle is not reduced any more, and the temperature and the pressure are reduced, and N is removed ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 6:

TABLE 6

544.38 g (0.6 mol phosphorus) of the above partial solution was mixed with a 10% by mass aqueous solution containing 66.64 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 80.4 g of a white solid in 96% yield. Dissolving a sample in a sodium hydroxide aqueous solution to prepare a nuclear magnetism, and obtaining the nuclear magnetism from a phosphorus spectrum: 25.1mol% of diethylphosphinate ions, 10.2mol% of dipropylphosphinate ions and 64.7mol% of ethylpropylphosphinate ions give x=0.251, y=0.647 and z=0.102.

Particle size test of sample, D ₅₀ ＝49.85μm。

Example 7 preparation of a hybrid salt having the composition of formula (i) wherein x=0.257, y=0.652, z=0.091, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise any more. The reaction solution was heated to about 90℃and the pressure gauge showed about 0.70MPa, and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and propylene was continuously fed into the reaction vessel, whereby the feed amount of olefin was measured by the gas flow meter. After 5 hours, the propylene was stopped and ethylene was started to be fed, and the pressure was maintained at 0.8MPa. After 15.5 hours, the pressure of the reaction kettle is not reduced any more, and the temperature and the pressure are reduced, and N is removed ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 7:

TABLE 7

471.95 g (phosphorus content: 0.54 mol) of the above-mentioned partial solution was mixed with a 10% by mass aqueous solution containing 59.98 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH value was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120 ℃ to give 72 g of a white solid in 96% yield. Dissolving a sample in a sodium hydroxide aqueous solution to prepare a nuclear magnetism, and obtaining the nuclear magnetism from a phosphorus spectrum: 25.7mol% diethylphosphinate ion, 9.1mol% dipropylphosphinate ion total, 65.2mol% ethylpropylphosphinate ion extended alkanedialkylphosphinate ion total, gives x=0.257, y=0.652, z=0.091.

Particle size test of sample, D ₅₀ ＝62.31μm。

The nuclear magnetism of the hybridized alkaline solution obtained in the embodiment is measured, ³¹ the P-NMR (nuclear magnetic resonance) spectrum is shown in FIG. 3, and the peak areas of the six peaks correspond to the molar concentrations of the six phosphinate groups respectively, so that the values of x, y and z can be conveniently calculated by the ratio of the peak areas, and the peak areas of the long-chain dialkylphosphinate ions and the ethylpropylphosphinate ions are combined during calculation.

Example 8 preparation of a hybrid salt having the composition of formula (i) wherein x=0.544, y=0.436, z=0.020, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water and poured into 1L of waterThe stainless steel autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise. The reaction solution was heated to about 90℃and the pressure gauge showed about 0.70MPa, and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and propylene was continuously fed into the reaction vessel, whereby the feed amount of olefin was measured by the gas flow meter. After 5 hours, the propylene was stopped and ethylene was started to be fed, and the pressure was maintained at 0.8MPa. After 14.5 hours, the pressure of the reaction kettle is not reduced any more, and the temperature and the pressure are reduced, and N is removed ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 8:

TABLE 8

458.58 g (phosphorus content: 0.54 mol) of the above-mentioned partial solution was mixed with a 10% by mass aqueous solution containing 59.98 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH value was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 56.3 g of a white solid in 93% yield. Dissolving a sample in a sodium hydroxide aqueous solution to prepare a nuclear magnetism, and obtaining the nuclear magnetism from a phosphorus spectrum: 54.4mol% diethylphosphinate ion, 2.0mol% dipropylphosphinate ion total, 43.6mol% ethylpropylphosphinate ion total, gives x=0.544, y=0.436, z=0.020.

Particle size test of sample, D ₅₀ ＝70.79μm。

Example 9 preparation of a hybrid salt having the composition of formula (i) wherein x=0.631, y=0.351, z=0.018, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise any more. The reaction solution was heated to about 90℃and the pressure gauge showed about 0.70MPa, and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and propylene was continuously fed into the reaction vessel, whereby the feed amount of olefin was measured by the gas flow meter. After 3 hours, the propylene was stopped and ethylene was started to be fed, and the pressure was maintained at 0.8MPa. After 12 hours, the pressure of the reaction kettle is not reduced any more, the temperature is reduced, the pressure is relieved, and N is reduced ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 9:

TABLE 9

376.79 g (0.45 mol phosphorus) of the above partial solution was mixed with a 10% strength by mass aqueous solution containing 49.98 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 56.3 g of a white solid in 94% yield. Dissolving a sample in a sodium hydroxide aqueous solution to prepare a nuclear magnetism, and obtaining the nuclear magnetism from a phosphorus spectrum: 62.7mol% of diethyl phosphinate ion, 1.7mol% of dipropyl phosphinate ion total, 34.9mol% of ethyl propyl phosphinate ion total, 0.4 mol% of propyl phosphinate ion and 0.3% of other phosphorus-containing compounds. After normalization, x=0.631, y=351, z=0.018.

Particle size test of sample, D ₅₀ ＝79.96μm。

Example 10 preparation of a hybrid salt having the composition of formula (i) wherein x=0.764, y=0.231, z=0.005, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise any more. The reaction solution was heated to about 90℃and the pressure gauge showed about 0.50MPa, and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and propylene was continuously fed into the reaction vessel, whereby the feed amount of olefin was measured by the gas flow meter. After 3 hours, the propylene was stopped and ethylene was started to be fed, and the pressure was maintained at 0.8MPa. After 13.5 hours, the pressure of the reaction kettle is not reduced any more, and the temperature and the pressure are reduced, and N is removed ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 10:

table 10

449.42 g (phosphorus content: 0.54 mol) of the above-mentioned partial solution was mixed with a 10% by mass aqueous solution containing 59.98 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH value was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 68.1 g of a white solid in 96% yield. Dissolving a sample in a sodium hydroxide aqueous solution to prepare a nuclear magnetism, and obtaining the nuclear magnetism from a phosphorus spectrum: 76.4mol% of diethylphosphinate ions, 0.5mol% of dipropylphosphinate ions and 23.1mol% of ethylpropylphosphinate ions, giving x=0.764, y=0.231 and z=0.005.

Particle size test of sample, D ₅₀ ＝69.99μm。

XRD testing of samples, relative of the resulting XRD measurementsThe layer spacing corresponding to the characteristic peak with highest intensity is(100％)。

Example 11 (comparative) preparation of a hybrid salt having the composition of formula (i) wherein x=0.902, y=0.096, z=0.002, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, ethylene was charged to a pressure of 0.8MPa. The reaction solution was heated to about 90℃and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and ethylene was continuously fed into the reaction vessel, whereby the amount of olefin fed was measured by a gas flow meter. After 4.5 hours, the ethylene introduction was stopped, and propylene introduction was started, with the pressure kept at about 0.8MPa. After 10.5 hours, the pressure of the reaction kettle is not reduced any more, and the temperature and the pressure are reduced, and N is removed ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 11:

TABLE 11

759.4 g (phosphorus content: 0.93 mol) of the above-mentioned partial solution was mixed with a 10% by mass aqueous solution containing 103.29 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH value was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 116.6 g of a white solid in 97% yield. Dissolving a sample in a sodium hydroxide aqueous solution to prepare a nuclear magnetism, and obtaining the nuclear magnetism from a phosphorus spectrum: 90.2mol% of diethylphosphinate ions, 0.2mol% of dipropylphosphinate ions and 9.6mol% of ethylpropylphosphinate ions give x=0.902, y=0.096 and z=0.002.

Particle size test of sample, D ₅₀ ＝80.56μm。

Example 12 (comparative) preparation of a hybrid salt having the composition of formula (i), wherein x=0.969, y=0.031, z=0, m=al, n=3

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, ethylene was charged to a pressure of 0.8MPa. The reaction solution was heated to about 90℃and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and ethylene was continuously fed into the reaction vessel, whereby the amount of olefin fed was measured by a gas flow meter. After 6.5 hours, the ethylene introduction was stopped, and propylene introduction was started, with the pressure kept at about 0.8MPa. After 9.5 hours, the pressure of the reaction kettle is not reduced any more, and the temperature and the pressure are reduced, and N is removed ₂ Purging and discharging to obtain colorless transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 12:

table 12

751.4 g (phosphorus content: 0.93 mol) of the above-mentioned partial solution was mixed with a 10% by mass aqueous solution containing 103.29 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH value was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the solution is hot, and washing the filter cake with clear water until the pH value is more than 4.5. The filter cake was then dried at 120℃to give 115.2 g of a white solid in 97% yield. A small part of white solid is taken to be dissolved in sodium hydroxide aqueous solution to be used as nuclear magnetism, and the obtained phosphorus spectrum is: 96.3mol% of diethyl phosphinate ion, 0mol% of dipropyl phosphinate ion total, 3.1mol% of ethyl propyl phosphinate ion total and 0.6mol% of propyl phosphinate ion total. After normalization, x=0.969, y=0.031, and z=0.

Particle size test of sample, D ₅₀ ＝76.33μm。

TGA tests were performed on the dialkylphosphinic acid hybrid salts, aluminum dipropylphosphinate and ADP obtained in examples 1-12, and the results are shown in FIG. 1, FIG. 1 being a graph of thermal weight loss (TGA) for hybrid salts having different x, y, z values and for ADP and aluminum dipropylphosphinate. From the figure, the higher the z value, the lower the thermal stability of the hybrid salt, and the higher the x, the higher the thermal stability.

FIG. 2a is an XRD pattern of the dialkylphosphinic acid hybrid salts, aluminum dipropylphosphinate, ADP and the physically mixed salts of aluminum dipropylphosphinate and ADP obtained in examples 1 to 12. As can be seen from fig. 2b, the simple physical mixed salt has 2 independent peaks in the XRD spectrum in the strongest absorption peak region and their d values are close to those of aluminum diethylphosphinate and aluminum dipropylphosphinate, respectively, and the hybrid salt having the composition of formula (i) has only one peak or overlapping peaks and d values substantially between those of aluminum diethylphosphinate and aluminum dipropylphosphinate. This means that the dialkylphosphinic acid hybrid salts of the present invention having the composition of formula (I) are not simply mixtures of aluminum diethylphosphinate, aluminum ethylpropylphosphinate, aluminum dipropylphosphinate, but rather comprise hybrid salts of structures in which at least two of the ions diethylphosphinate, ethylpropylphosphinate, dipropylphosphinate are paired with the same aluminum atom.

Example 13

Polyamide PA66, the hybrid salt prepared in example 1 and the compound antioxidant are mixed in a weight ratio of 79.6:20:0.4 in an internal mixer with a rotation speed of 50 revolutions per minute, the temperature is set to 280 ℃, and the mixture is taken out, cooled and dried after 5 minutes. Then filling the mixture into a mould, preheating the mixture for 10 minutes in a flat vulcanizing machine at 280 ℃, maintaining the pressure for 5 minutes under 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating of the 1.6mm sample was UL 94V-1.

Example 14

Polyamide PA6, the hybrid salt prepared in example 1 and the compound antioxidant are mixed in an internal mixer with the rotating speed of 50 revolutions per minute according to the weight ratio of 79.6:20:0.4, the temperature is set to 260 ℃, and the mixture is taken out, cooled and dried after 5 minutes. Then filling the mixture into a mould, preheating the mixture for 10 minutes at 260 ℃ by a flat vulcanizing machine, maintaining the pressure for 5 minutes at 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating of the 1.6mm sample was UL 94V-1.

Examples 15 to 51

The hybrid salts prepared in examples 1 to 10 were prepared and tested in polyamide PA66, PA6 in the same manner as in examples 13, 14, respectively, and the results are shown in tables 14, 15 and 16.

Comparative example 1 aluminum dipropylphosphinate

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and the solution was put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, propylene was charged until the pressure did not rise any more. The reaction solution was heated to about 90℃and the pressure gauge was set at 0.8MPa, and then a sodium persulfate aqueous solution having a concentration of 4% by mass was fed at a constant rate of 10ml/h, and propylene was continuously fed into the reaction vessel, and the propylene feed rate was measured by the gas flow meter. After 15.5 hours, the system pressure is not reduced any more, the reaction is stopped, the temperature is reduced, the pressure is relieved, and N is removed ₂ And (5) purging and discharging to obtain transparent reaction liquid.

Sampling in the middle of the reaction, making nuclear magnetism, ³¹ the P-NMR results are shown in Table 13:

TABLE 13

525 g (0.6 mol of phosphorus) of the partial solution is slowly mixed with 10% mass concentration aqueous solution containing 66.64 g of aluminum sulfate octadecabydrate, the reaction temperature is controlled to be 70 ℃, and the pH value is regulated to be less than or equal to 3.0, so that a large amount of precipitate is obtained. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the filter cake is hot, filtering slowly, and washing the filter cake with clear water until the pH is more than 4.5. The filter cake was then dried at 120℃to give 92.8 g of a white solid in 98% yield.

Particle size test of sample, D ₅₀ ＝5.21μm。

Comparative example 2 aluminum diethylphosphinate

100 g of sodium hypophosphite monohydrate was dissolved in 500 g of water, and put into a 1L stainless steel autoclave, the autoclave was replaced twice with nitrogen, and after vacuum pumping, ethylene was charged to 0.8MPa. The reaction solution was heated to about 90℃and then a 4% strength by mass aqueous sodium persulfate solution was fed at a constant speed of 10ml/h, and ethylene was continuously fed into the reaction vessel, and the ethylene feed was measured by a gas flow meter. After 8 hours, the system pressure is not reduced any more, the reaction is stopped, the temperature is reduced, the pressure is relieved, and N is added ₂ And (5) purging and discharging to obtain transparent reaction liquid. Sampling after the reaction is finished, making nuclear magnetism, ³¹ the P-NMR results showed that:

190 g (0.24 mol phosphorus) of the partial solution was mixed with a 10% aqueous solution containing 26.66 g of aluminum sulfate octadecabydrate, the reaction temperature was controlled to 70℃and the pH was adjusted to 3.0 or less to obtain a large amount of precipitate. After the addition and mixing are completed, the temperature is kept for 0.5 hour. Filtering while the filter cake is hot, filtering slowly, and washing the filter cake with clear water until the pH is more than 4.5. The filter cake was then dried at 120℃to give 29.8 g of a white solid in 95.4% yield.

Particle size test of sample, D ₅₀ ＝29.5μm。

Comparative example 3

Mixing polyamide PA66, aluminum dipropyl phosphinate prepared in comparative example 1 and a compound antioxidant according to the weight ratio of 84.6:15:0.4, in an internal mixer with the rotating speed of 50 revolutions per minute, setting the temperature to 280 ℃, taking out after 5 minutes, cooling and drying. Then filling the mixture into a mould, preheating the mixture for 10 minutes in a flat vulcanizing machine at 280 ℃, maintaining the pressure for 5 minutes under 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating of the 1.6mm sample was UL 94V-0.

Comparative example 4

Mixing polyamide PA66, aluminum dipropyl phosphinate prepared in comparative example 1 and a compound antioxidant according to the weight ratio of 87.1:12.5:0.4, in an internal mixer with the rotating speed of 50 revolutions per minute, setting the temperature to 280 ℃, taking out after 5 minutes, cooling and drying. Then filling the mixture into a mould, preheating the mixture for 10 minutes in a flat vulcanizing machine at 280 ℃, maintaining the pressure for 5 minutes under 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating of the 1.6mm sample was UL 94V-0.

Comparative example 5

Mixing polyamide PA66, aluminum dipropyl phosphinate prepared in comparative example 1 and a compound antioxidant according to the weight ratio of 89.6:10:0.4, in an internal mixer with the rotating speed of 50 revolutions per minute, setting the temperature to 280 ℃, taking out after 5 minutes, cooling and drying. Then filling the mixture into a mould, preheating the mixture for 10 minutes in a flat vulcanizing machine at 280 ℃, maintaining the pressure for 5 minutes under 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating of the 1.6mm sample was UL 94V-1.

Comparative example 6

Mixing polyamide PA6, aluminum dipropyl phosphinate prepared in comparative example 1 and a compound antioxidant according to the weight ratio of 84.6:15:0.4, in an internal mixer with the rotating speed of 50 revolutions per minute, setting the temperature to 260 ℃, taking out after 5 minutes, cooling and drying. Then filling the mixture into a mould, preheating the mixture for 10 minutes at 260 ℃ by a flat vulcanizing machine, maintaining the pressure for 5 minutes at 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating of the 1.6mm sample was UL-94V-1.

Comparative example 7

Mixing polyamide PA66, the diethyl aluminum phosphinate prepared in comparative example 2 and the compound antioxidant according to the weight ratio of 84.6:15:0.4, in an internal mixer with the rotating speed of 50 revolutions per minute, setting the temperature to 280 ℃, taking out after 5 minutes, cooling and drying. Then filling the mixture into a mould, preheating the mixture for 10 minutes in a flat vulcanizing machine at 280 ℃, maintaining the pressure for 5 minutes under 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating for the 1.6mm sample was UL94 no rating.

Comparative example 8

Mixing polyamide PA6, the diethyl aluminum phosphinate prepared in comparative example 2 and the compound antioxidant according to the weight ratio of 84.6:15:0.4 in an internal mixer with the rotating speed of 50 revolutions per minute, setting the temperature to 260 ℃, taking out after 5 minutes, cooling and drying. Then filling the mixture into a mould, preheating the mixture for 10 minutes at 260 ℃ by a flat vulcanizing machine, maintaining the pressure for 5 minutes at 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating of the 1.6mm sample was UL-94 no rating.

Comparative example 9

Mixing polyamide PA66, ADP and compound antioxidant according to the weight ratio of 84.6:15:0.4 in an internal mixer with the rotating speed of 50 revolutions per minute, setting the temperature to 280 ℃, taking out after 5 minutes, cooling and drying. Then filling the mixture into a mould, preheating the mixture for 10 minutes in a flat vulcanizing machine at 280 ℃, maintaining the pressure for 5 minutes under 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating for the 1.6mm sample was UL94 no rating.

Comparative example 10

Mixing polyamide PA6, ADP and compound antioxidant according to the weight ratio of 84.6:15:0.4 in an internal mixer with the rotating speed of 50 revolutions per minute, setting the temperature to 260 ℃, taking out after 5 minutes, cooling and drying. Then filling the mixture into a mould, preheating the mixture for 10 minutes at 260 ℃ by a flat vulcanizing machine, maintaining the pressure for 5 minutes at 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating of the 1.6mm sample was UL-94 no rating.

Comparative example 11

Polyamide PA66, the hybrid salt prepared in example 11 and the compound antioxidant are mixed in an internal mixer with the rotating speed of 50 revolutions per minute according to the weight ratio of 84.6:15:0.4, the temperature is set to 280 ℃, and the mixture is taken out for cooling and drying after 5 minutes. Then filling the mixture into a mould, preheating the mixture for 10 minutes in a flat vulcanizing machine at 280 ℃, maintaining the pressure for 5 minutes under 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating for the 1.6mm sample was UL94 no rating.

Comparative example 12

The polyamide PA6, the hybrid salt prepared in example 11 and the compound antioxidant are mixed in an internal mixer with the rotating speed of 50 revolutions per minute according to the weight ratio of 84.6:15:0.4, the temperature is set to 260 ℃, and the mixture is taken out for cooling and drying after 5 minutes. Then filling the mixture into a mould, preheating the mixture for 10 minutes at 260 ℃ by a flat vulcanizing machine, maintaining the pressure for 5 minutes at 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating of the 1.6mm sample was UL-94 no rating.

Comparative example 13

Polyamide PA66, the hybrid salt prepared in example 12 and the compound antioxidant are mixed in an internal mixer with the rotating speed of 50 revolutions per minute according to the weight ratio of 84.6:15:0.4, the temperature is set to 280 ℃, and the mixture is taken out for cooling and drying after 5 minutes. Then filling the mixture into a mould, preheating the mixture for 10 minutes in a flat vulcanizing machine at 280 ℃, maintaining the pressure for 5 minutes under 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating for the 1.6mm sample was UL94 no rating.

Comparative example 14

The polyamide PA6, the hybrid salt prepared in example 12 and the compound antioxidant are mixed in an internal mixer with the rotating speed of 50 revolutions per minute according to the weight ratio of 84.6:15:0.4, the temperature is set to 260 ℃, and the mixture is taken out for cooling and drying after 5 minutes. Then filling the mixture into a mould, preheating the mixture for 10 minutes at 260 ℃ by a flat vulcanizing machine, maintaining the pressure for 5 minutes at 10MPa, and then cold pressing the mixture. And cutting the sample after the sample is cooled, and testing. The flame retardant rating of the 1.6mm sample was UL-94 no rating.

Comparative examples 3-14 the test results are shown in Table 17.

Examples 15-51 illustrate the outstanding flame retardant efficiency of polyamides with flame retardants containing the dialkylphosphinic acid hybrid salts of the present invention. When preparing flame-retardant polyamide, the operation has no obvious dust. The prepared flame-retardant PA66 spline has good toughness and no obvious degradation. Comparative example demonstrates that under the same conditions, the particle sizes of the aluminum dipropylphosphinate and aluminum diethylphosphinate obtained are small compared to the particle size of the hybrid salt, which is unexpected. Comparative examples 3-6 show that dipropylphosphinate has a certain flame retardancy, but its flame retardant efficiency for polyamides is inferior to the hybrid salts having the structure of formula (I) according to the present invention, see examples 17, 21, 22, 27, 30, 31, 34, 35, 40, 44 and 47. And in the preparation of flame-retardant polyamide, dipropyl phosphinate is observed to have large dust, so that the operation environment is poor. In addition, as can be seen from fig. 1, the thermal stability is too low, and the prepared flame-retardant PA66 has high brittleness, which indicates that the degradation is serious. Comparative examples 7-10 demonstrate the low flame retardant efficiency of pure aluminum diethylphosphinate to polyamides. Comparative examples 11 to 14 show that when the proportion of diethylphosphinate in the hybrid salt having the structure of formula (I) is too high, i.e., x >0.8, the flame retardant efficiency of the hybrid salt to polyamide is lowered.

While the application has been described in terms of preferred embodiments, it will be understood by those skilled in the art that various changes and modifications can be made without departing from the scope of the application, and it is intended that the application is not limited to the specific embodiments disclosed.

Claims

1. A dialkylphosphinic acid hybrid salt, characterized in that the dialkylphosphinic acid hybrid salt is selected from at least one of the compounds having the chemical formula shown in formula (i):

wherein M is a central atom; r, R ₁ 、R ₂ Are independently selected from any one of n-propyl and isopropyl; diethyl phosphinate ionThe ethyl propyl phosphinate ion and the dipropyl phosphinate ion are all ligands; and at least two of diethyl phosphinate ion, ethyl propyl phosphinate ion and dipropyl phosphinate ion are paired with the same metal atom, and one of the ligands must be ethyl propyl phosphinate ion;

n is the valence of the metal M; n is selected from 2,3 or 4;

2. The dialkylphosphinic acid hybridization salt according to claim 1, wherein the group IIA metal element is selected from at least one of Be, mg, ca, sr, ba;

the III A metal element is Al;

the group IVA metal element is Sn;

the group VA metal element is Sb;

the lanthanide metal element is Ce;

preferably, 0.ltoreq.x.ltoreq.0.80; y is more than or equal to 0.05 and less than or equal to 0.70; z is more than or equal to 0.005 and less than or equal to 0.92;

preferably, 0.ltoreq.x.ltoreq.0.66; y is more than or equal to 0.30 and less than or equal to 0.70; z is more than or equal to 0.01 and less than or equal to 0.60;

preferably, 0.ltoreq.x.ltoreq.0.30; y is more than or equal to 0.35 and less than or equal to 0.70; z is more than or equal to 0.05 and less than or equal to 0.60;

preferably, m=al; n=3.

3. A process for the preparation of a dialkylphosphinic acid hybrid salt according to claim 1 or 2, characterized in that said process comprises:

4. A process according to claim 3, characterized in that the obtaining of the mixture a comprises the following steps:

introducing ethylene and propylene into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator, and reacting II to obtain a mixture A;

preferably, in the aqueous solution, the mass of the water is 10-99% of the total mass of the aqueous solution;

preferably, the conditions of reaction II are: the temperature is 0-250 ℃; the time is 0.01-50 h; the pressure is 0-3MPa;

preferably, the molar ratio of the free radical initiator to the total amount of hypophosphorous acid and/or its alkali metal salts is from 0.001 to 0.1:1, a step of;

preferably, the molar ratio of hypophosphorous acid and/or its alkali metal salt, ethylene and propylene is 1:0.05-1.8:0.2-1.95;

preferably, the obtaining of the mixture a comprises the following steps:

introducing propylene into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator for reaction, stopping introducing propylene after the molar ratio of the introduced propylene to the total phosphorus of the hypophosphorous acid and/or alkali metal salt thereof reaches (y+2z)/1 in the formula (I), and continuing introducing ethylene for reaction to obtain a mixture A;

preferably, the obtaining of the mixture a comprises the following steps:

Introducing propylene and part of ethylene into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator to react, wherein the total phosphorus mole ratio of ethylene to hypophosphorous acid and/or alkali metal salt thereof is smaller than (2x+y)/1 in the formula (I), stopping introducing propylene after the total phosphorus mole ratio of the introduced propylene to hypophosphorous acid and/or alkali metal salt thereof reaches (y+2z)/1 in the formula (I), and continuing introducing the rest of ethylene to react to obtain a mixture A;

preferably, the obtaining of the mixture a comprises the following steps:

introducing part of ethylene into an aqueous solution containing hypophosphorous acid and/or alkali metal salt thereof and a free radical initiator, wherein the mole ratio of the part of ethylene to the hypophosphorous acid and/or alkali metal salt thereof total phosphorus is (2x+y)/1 in the formula (I), continuing introducing propylene to react after the part of ethylene is reacted completely, and stopping introducing propylene to react after the mole ratio of the introduced propylene to the total phosphorus in the initial hypophosphorous acid and/or alkali metal salt thereof reaches (y+2z)/1 in the formula (I), thereby obtaining the mixture A;

preferably, the source of the metal element M is selected from at least one of metal element M salts;

Preferably, the metal element M salt is selected from at least one of nitrate, sulfate, hydrochloride, acetate, and oxide of the metal element M.

5. A flame retardant selected from at least one of the dialkylphosphinic acid hybrid salts according to claim 1 or 2, and the dialkylphosphinic acid hybrid salts prepared according to any one of the methods of claim 3 or 4.

6. The flame retardant material is characterized by comprising a flame retardant P and a thermoplastic polymer material;

the flame retardant P is at least one selected from the flame retardants described in claim 5.

7. The flame retardant material according to claim 6, wherein the mass content of the flame retardant P in the flame retardant material is 1 to 35%;

preferably, in the flame retardant material, a functional additive is further included;

the functional additive is at least one selected from reinforcing agents, anti-dripping agents, stabilizing agents, pigments, dyes, char-forming catalysts, dispersing agents, nucleating agents, inorganic fillers and antioxidants;

preferably, the functional additive is present in the flame retardant material in an amount of 5 to 40% by mass.

8. The flame retardant material according to claim 7, further comprising a flame retardant Q in the flame retardant material;

9. The flame retardant material according to claim 8, wherein the mass content of the flame retardant Q in the flame retardant material is 0.5 to 20%.

10. The flame retardant material according to claim 6, wherein the thermoplastic polymer material is at least one selected from the group consisting of polyamide and polyester.