Polymer additive, preparation method and polymer composition

Abstract

The invention belongs to the technical field of flame retardant materials, and provides a polymer additive and a preparation method thereof, and a polymer composition, the polymer additive comprises the following components by mass: 95-99.88 parts of diethyl phosphinate, 0.1-3 parts of ethyl butyl phosphinate, 0.01-1 part of ethyl phosphonate, and 0.01-1 part of monoethyl phosphinate; the water-soluble acid value of the polymer additive is 0.1-0.3 mg KOH / g, and the polymer additive has low acidity, and when the polymer additive is used as a flame retardant for a polymer composition, the generation of high-temperature decomposition of dialkyl phosphinic acid can be slowed down, so that the polymer composition has lower water boiling precipitate content, the use stability of the polymer composition under damp and hot conditions is improved, the service life of the polymer composition is prolonged, and the service life of the polymer composition is prolonged. And moreover, the amount of mold scale generated in the injection molding process is smaller, the injection molding production efficiency can be improved, and the product appearance is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of flame retardant materials, and specifically relates to a polymer additive and a preparation method thereof, and a polymer composition. Background Art

[0002] Dialkyl phosphinate is a halogen-free, green and environmentally friendly flame retardant with the characteristics of high flame retardancy, small particle size, low specific gravity, low smoke, good dispersibility and compatibility, etc. It has little effect on the physical and electrical properties of the base resin. The flame retardant material using dialkyl phosphinate has a high CTI (comparative tracking index) and low smoke emission during combustion, which is highly valued by the industry. Moreover, the flame retardant polyamide using dialkyl phosphinate has excellent mechanical and electrical properties, and has a very broad application prospect in the electrical and electrical industry manufacturers.

[0003] In the commercial application of dialkyl phosphinate flame retardant materials, people have found that such materials have some performance deficiencies. For example, when dialkyl phosphinate flame retards PBT and polyamide, dialkyl phosphinate will decompose into dialkyl phosphinate during high temperature. Moreover, since polyamide contains more polar amide groups, when dialkyl phosphinate is used for flame retardant polyamide materials, polyamide is more likely to absorb water and has a higher water absorption rate. For example, the water absorption rate of polyamide 66 resin can reach 2.7% under the conditions of 23°C and 50% humidity. During the high-temperature processing of extrusion or injection molding, dialkyl phosphinate itself has a certain acidity, and the heating process will also decompose acidic substances such as dialkyl phosphinate, which can easily promote the decomposition of the system and lead to a large amount of gas in the processing process. In the process of repeated injection molding, serious mold scale often appears on the mold, and the mold needs to be cleaned frequently, resulting in low production efficiency; more importantly, the generation of mold scale will affect the appearance of the product, making it difficult to promote the use of the product.

[0004] At present, the main method to solve the mold scale problem in injection molding of dialkyl phosphinate flame retardant polyamide materials is to add an acid absorber to the system to reduce the acidity of the system. For example, EP2417191A1 discloses a halogen-free flame retardant polyamide composition, by adding calcium oxide to the system, it is neutralized with some acidic substances in the system, the acidity of the system is reduced, the decomposition of the matrix resin is reduced, and the corrosion to the mold during high-temperature injection molding is reduced. Although this method is helpful to reduce mold scale, calcium oxide is easy to absorb moisture, resulting in a high water absorption rate of the system, which is difficult to control during processing. CN114874616A discloses a halogen-free flame retardant polyamide composite material, by adding a composite system of metal oxides and polyhydroxy compounds in the system, the prepared polyamide material has better anti-yellowing properties, lower mold scale, and more continuous opening and closing times. CN112409786A adds a certain amount of ethylene copolymer as an adsorbent in the system, so that the prepared halogen-free flame retardant thermoplastic polyamide has lower mold scale.

[0005] Although the added adsorbent can improve the mold deposit of dialkyl phosphite flame retardant polyamide to a certain extent, the added additives will increase the cost, and the addition of new additives will inevitably affect other properties of flame retardant polyamide. For example, the addition of inorganic metal oxides will lead to a decrease in the mechanical properties of the material, there are compatibility issues between the additive and the matrix, and it brings a higher risk of additive precipitation.

[0006] Therefore, it is desired in the art to develop a new polymer additive which, when used for flame retardant modification of polymer materials, can make the polymer materials have lower mold deposit and less precipitation of the additive. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide a polymer additive and a preparation method and a polymer composition. The polymer additive has a low acid value and is used as a flame retardant to prepare a polymer composition, which can effectively reduce mold deposits and make the polymer composition have a lower content of water-boiling precipitates, thereby extending its service life under hot and humid conditions.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a polymer additive, wherein the polymer additive comprises the following components in parts by mass:

[0010] 95-99.88 parts of diethylphosphinate

[0011] Ethyl butyl phosphinate 0.1-3 parts

[0012] Ethylphosphonate 0.01-1 part

[0013] 0.01-1 part of monoethylphosphinate;

[0014] The water-soluble acid value of the polymer additive is 0.1-0.3 mg KOH / g.

[0015] The polymer additive provided by the present invention comprises a combination of diethyl phosphinate, ethyl butyl phosphinate, ethyl phosphonate and monoethyl phosphinate in specific contents, has low acidity, and when used as a flame retardant in a polymer composition, can slow down the occurrence of high-temperature decomposition of dialkyl phosphinate, so that the polymer composition has a lower content of boiled precipitates, improves its use stability under hot and humid conditions, prolongs its service life, and generates less mold deposit in the injection molding process, thereby improving the injection molding production efficiency and improving the appearance of the product.

[0016] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0017] The mass fraction of diethylphosphinate in the polymer additive is 95-99.88 parts, for example, it can be 95.5 parts, 96 parts, 96.2 parts, 96.5 parts, 96.8 parts, 96.9 parts, 97 parts, 97.2 parts, 97.5 parts, 97.8 parts, 98 parts, 98.2 parts, 98.5 parts, 98.8 parts, 99 parts, 99.2 parts, 99.5 parts, 99.6 parts or 99.8 parts, as well as specific points between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0018] Preferably, the mass percentage of diethylphosphinate in the polymer additive is ≥94%, for example, it can be 94.5%, 95%, 95.5%, 96%, 96.2%, 96.5%, 96.8%, 96.9%, 97%, 97.2%, 97.5%, 97.8%, 98%, 98.2%, 98.5%, 98.8%, 99%, 99.2%, 99.5%, 99.8% or 99.88%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0019] The mass fraction of ethyl butyl phosphinate in the polymer additive is 0.1-3 parts, for example, it can be 0.12 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.7 parts, 2.8 parts or 2.9 parts, as well as specific points between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0020] The mass fraction of ethyl phosphonate in the polymer additive is 0.01-1 part, for example, it can be 0.02 part, 0.05 part, 0.1 part, 0.15 part, 0.2 part, 0.25 part, 0.3 part, 0.35 part, 0.4 part, 0.45 part, 0.5 part, 0.55 part, 0.6 part, 0.65 part, 0.7 part, 0.75 part, 0.8 part, 0.85 part, 0.9 part or 0.95 part, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0021] The mass fraction of monoethylphosphinate in the polymer additive is 0.01-1 part, for example, it can be 0.02 part, 0.05 part, 0.1 part, 0.15 part, 0.2 part, 0.25 part, 0.3 part, 0.35 part, 0.4 part, 0.45 part, 0.5 part, 0.55 part, 0.6 part, 0.65 part, 0.7 part, 0.75 part, 0.8 part, 0.85 part, 0.9 part or 0.95 part, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0022] Exemplarily, the mass parts of diethylphosphinate, diethylphosphinate, ethylphosphonate, and monoethylphosphinate in the polymer additive can be obtained by liquid chromatography analysis and testing, for example, the sample to be tested is dissolved in a sulfuric acid aqueous solution (mass concentration 30%) with a mass ratio of 5 times that of the sample, and then diluted 10-30 times with a mobile phase for analysis and testing; the mobile phase is a mixture of water and methanol in a mass ratio of 9:1, trifluoroacetic acid with a volume content of 0.5%, a ShimNex CSC18 chromatographic column is added, and the flow rate is 0.6 mL / min; the mass content of each component is calculated by the area normalization method.

[0023] In the present invention, the water-soluble acid value of the polymer additive is 0.1-0.3 mg KOH / g, for example, it can be 0.11 mg KOH / g, 0.12 mg KOH / g, 0.15 mg KOH / g, 0.18 mg KOH / g, 0.2 mg KOH / g, 0.22 mgKOH / g, 0.25 mg KOH / g, 0.28 mg KOH / g or 0.29 mg KOH / g, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0024] For example, the water-soluble acid value of the polymer additive can be obtained by testing as follows: 1 g of the sample to be tested is diluted with ethanol (the mass of ethanol is m 乙醇 ) is evenly moistened, add water (the mass of water is m 水 ), boiled in a sealed water tank at 90℃ for 1 h, cooled to 25℃ and kept at constant temperature for 30 min, and then supplemented with ethanol water solution to the total mass before boiling; filtered, and the mass of the clear filtrate was m 11 The filtrate was tested by potentiometric titration to determine the acid value (m 水 +m 乙醇 ), wherein the concentration of potassium hydroxide solution used for titration is 0.05 mol / L, and the water-soluble acid value of polymer additive = test acid value × (m 水 +m 乙醇 ) / m 11 -Blank acid value.

[0025] Preferably, the organic acid value of the polymer additive is ≤0.05 mg KOH / g, for example, it may be 0.001 mg KOH / g, 0.005 mg KOH / g, 0.008 mg KOH / g, 0.01 mg KOH / g, 0.02 mg KOH / g, 0.025 mg KOH / g, 0.028 mg KOH / g, 0.03 mg KOH / g, 0.032 mg KOH / g, 0.035 mg KOH / g, 0.038 mg KOH / g, 0.04 mg KOH / g or 0.045 mg KOH / g, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and 0.001-0.04 mg KOH / g is further preferred.

[0026] For example, the organic acid value of the polymer additive can be obtained by testing as follows: 1 g of the sample to be tested is diluted with dichloromethane (the mass of dichloromethane is m 二氯甲烷) was uniformly moistened, and then boiled in a sealed container at 90°C for 1 h, cooled to 25°C and kept at this temperature for 30 min, and dichloromethane was added to the total mass before boiling; filtered, and the mass of the clear filtrate was m 12 The filtrate is tested by potentiometric titration to determine the acid value, and the weight is determined by potentiometric titration to determine the m 二氯甲烷 The blank acid value of the titration was 0.05 mol / L potassium hydroxide solution. The organic acid value of the polymer additive = test acid value × m 二氯甲烷 / m 12 -Blank acid value.

[0027] Preferably, the mass content of sulfate in the polymer additive is 100-500 ppm, for example, it can be 120 ppm, 150 ppm, 200 ppm, 250 ppm, 270 ppm, 300 ppm, 350 ppm, 400 ppm, 420 ppm, 450 ppm or 480 ppm, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 110-430 ppm is further preferred.

[0028] For example, the mass content of sulfate in the polymer additive is determined by an external standard method using ion chromatography technology with reference to the method in standard EN 14582:2007-Determination of halogen content.

[0029] Preferably, the diethylphosphinate includes any one of diethylphosphinate aluminum, diethylphosphinate calcium, diethylphosphinate copper, diethylphosphinate zinc, diethylphosphinate iron, diethylphosphinate titanium, or a combination of at least two thereof, and diethylphosphinate aluminum is further preferred.

[0030] Preferably, the ethylbutylphosphinate includes any one of ethylbutylphosphinate aluminum, ethylbutylphosphinate calcium, ethylbutylphosphinate copper, ethylbutylphosphinate zinc, ethylbutylphosphinate iron, ethylbutylphosphinate titanium or a combination of at least two thereof, and ethylbutylphosphinate aluminum is further preferred.

[0031] Preferably, the ethylphosphonate includes any one of aluminum ethylphosphonate, calcium ethylphosphonate, copper ethylphosphonate, zinc ethylphosphonate, iron ethylphosphonate, and titanium ethylphosphonate, or a combination of at least two thereof, and aluminum ethylphosphonate is further preferred.

[0032] Preferably, the monoethylphosphinate includes any one of monoethylphosphinate aluminum, monoethylphosphinate calcium, monoethylphosphinate copper, monoethylphosphinate zinc, monoethylphosphinate iron, monoethylphosphinate titanium, or a combination of at least two thereof, and monoethylphosphinate aluminum is further preferred.

[0033] Preferably, the polymer additive further includes alkali-insoluble substances, and the alkali-insoluble substances include any one of hydroxides, oxides, phosphates, pyrophosphates, polyphosphates, and phosphites, or a combination of at least two of them.

[0034] Preferably, the alkali-insoluble material includes any one of aluminum hydroxide, aluminum oxide, aluminum phosphate, aluminum pyrophosphate, aluminum polyphosphate, and aluminum phosphite, or a combination of at least two thereof.

[0035] Preferably, the mass fraction of alkali-insoluble matter in the polymer additive is ≤3 parts, for example, it can be 0, 0.01 parts, 0.02 parts, 0.05 parts, 0.08 parts, 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts or 2.8 parts, as well as specific point values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0036] Exemplarily, the mass fraction of alkali-insoluble matter in the polymer additive is tested by the following method: the sample to be tested is mixed with an aqueous sodium hydroxide solution (mass concentration 3%) at a mass ratio of 1:100, stirred at 35°C for 30 min, filtered through filter paper with an accuracy of ≤2 μm, and rinsed with water 3 times. The filter paper is dried and weighed, and the mass increase relative to the mass before filtration with filter paper (dry filter paper) is the mass of the insoluble matter, and the ratio of the mass of the insoluble matter to the mass of the sample to be tested is the mass content of the alkali-insoluble matter.

[0037] Optionally, the polymer additive also includes other phosphorus-containing compounds, and the mass fraction of other phosphorus-containing compounds in the polymer additive is ≤1%, for example, it can be 0, 0.01 part, 0.05 part, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part or 0.95 part, and specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 0.05-0.4 part is further preferred.

[0038] It should be noted that the other phosphorus-containing compounds are alkali-soluble and phosphorus-containing substances different from diethyl phosphinate, ethyl butyl phosphinate, ethyl phosphonate, and monoethyl phosphinate, and their mass fractions can be measured by nuclear magnetic phosphorus spectrum. In the nuclear magnetic phosphorus spectrum, the integrated area of ​​other peaks except diethyl phosphinate, ethyl butyl phosphinate, ethyl phosphonate, and monoethyl phosphinate represents the content of the other phosphorus-containing compounds.

[0039] Preferably, the polymer additive has a D 50The particle size is 1-100 μm, for example, it can be 10 μm, 20 μm, 30 μm, 33 μm, 35 μm, 38 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 95 μm, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 20-60 μm is further preferred.

[0040] The D of the polymer additive 50 The particle size refers to the particle size corresponding to 50% of the cumulative volume distribution percentage, which can be measured by a laser particle size analyzer with reference to the standard GB / T 19077-2016 particle size distribution laser diffraction method.

[0041] Preferably, the water content of the polymer additive is ≤1 wt%, for example, it can be 0, 0.01 wt%, 0.02 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt% or 0.9 wt%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 0.05-0.3 wt% is further preferred.

[0042] For example, the water content of the polymer additive can be obtained by testing with an infrared moisture analyzer, for example, using the MA 35 infrared moisture analyzer produced by Sartorius of Germany, and automatically testing the water content of the sample after it is placed at 120° C. for 30 minutes.

[0043] Preferably, the phosphorus content of the polymer additive is 22-25 wt%, for example, it may be 22.2 wt%, 22.5 wt%, 22.8 wt%, 23 wt%, 23.2 wt%, 23.5 wt%, 23.8 wt%, 24 wt%, 24.2 wt%, 24.5wt% or 24.8 wt%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0044] For example, the phosphorus content of the polymer additive can be tested by the following method: dissolving the sample to be tested in an aqueous sulfuric acid solution (mass concentration 30%), and testing with reference to standard GB / T 11893-1989 "Determination of total phosphorus in water - ammonium molybdate spectrophotometry".

[0045] In a second aspect, the present invention provides a method for preparing the polymer additive as described in the first aspect, wherein the preparation method comprises method I or method II.

[0046] The method I comprises the following steps:

[0047] (A1) a hypophosphite aqueous solution and an antioxidant react with ethylene in the presence of an initiator to obtain a diethylphosphinate aqueous solution;

[0048] (A2) mixing the aqueous solution of diethylphosphinate obtained in step (A1), the aqueous solution of metal salt and alkaline solution, and reacting them at a pH value of 3.5-3.8 to obtain a diethylphosphinate metal salt slurry;

[0049] (A3) mixing the diethylphosphinate metal salt slurry obtained in step (A2) with a flocculant, stirring to obtain diethylphosphinate metal salt flocs; filtering, washing and drying the diethylphosphinate metal salt flocs to obtain the polymer additive.

[0050] The method II comprises the following steps:

[0051] (B1) the hypophosphorous acid aqueous solution and the antioxidant react with ethylene under the action of an initiator to produce a diethylphosphinic acid aqueous solution;

[0052] (B2) reacting the aqueous solution of diethylphosphinic acid obtained in step (B1), sulfuric acid and a metal hydroxide, and then adding an alkali solution to obtain a diethylphosphinic acid salt slurry having a pH value of 3.8-4.2;

[0053] (B3) mixing the diethylphosphinate slurry obtained in step (B2) with a flocculant, stirring, and obtaining diethylphosphinate flocs; filtering, washing, and drying the diethylphosphinate flocs to obtain the polymer additive.

[0054] The present invention has found that the reaction process of hypophosphorous acid or its salt with ethylene is generally carried out in the presence of an initiator of a free radical initiator. Hypophosphorous acid or its salt has strong reducing properties due to the presence of a PH bond, so free radical reaction and oxidation reaction exist simultaneously. The present invention uses an antioxidant, which can donate electrons to the oxidant, thereby reducing it to a relatively stable substance. Moreover, the free radical reaction of hypophosphorous acid or its salt with ethylene is a strong exothermic reaction, which is prone to uncontrollable phenomena in the production process, and is accompanied by many side reactions. The antioxidant can capture free radicals in the form of free radical reactions and neutralize their activity, which can effectively slow down the exothermic effect and reduce the occurrence of side reactions, making the production process controllable. Further, the present invention has found that the pH of the reaction system has a great influence on the crystallization behavior of the additive precipitation process, thereby affecting the acid value of the polymer additive. The present invention controls the pH of the step of preparing diethylphosphinate slurry, which can improve the acidity of the target product. In addition, the present invention also introduces a flocculant, so that the polymer additive particles are adsorbed and bonded to the molecular chain of the flocculant, improves the effect of filtering and washing the polymer additive, and can effectively reduce the acidity of the polymer additive after filtering and washing.

[0055] In summary, the present invention designs a preparation method for a polymer additive. By designing materials such as antioxidants and flocculants, designing process steps and process parameters such as pH, and their combined effects, the polymer additive with a low acid value is prepared. When used as a flame retardant to prepare a polymer composition, it can reduce mold deposits and make the polymer composition have a lower content of water-boiling precipitates, thereby greatly improving the service life of the polymer composition under hot and humid conditions.

[0056] Preferably, the antioxidants in step (A1) and step (B1) independently include any one of hindered phenol antioxidants, hindered amine antioxidants, phosphite antioxidants, and thioester antioxidants, or a combination of at least two thereof, preferably any one of hindered phenol antioxidants, phosphite antioxidants, and thioester antioxidants, or a combination of at least two thereof.

[0057] Further preferably, the antioxidants in step (A1) and step (B1) independently include any one of pentaerythritol tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1010), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine (antioxidant 1098), tris(2,4-di-tert-butylphenyl)phosphite (antioxidant 168), 2,6-di-tert-butyl-p-cresol (antioxidant BHT), distearyl β,β-thiodipropionate (antioxidant DSTP), antioxidant 215, and antioxidant 225, or a combination of at least two thereof.

[0058] The antioxidant in the present invention can be a single component, such as any one of the antioxidants listed above, or a combination of multiple compound antioxidants, such as a combination of a hindered phenol antioxidant and a phosphite antioxidant. A typical combination is a compound of antioxidant 1010 and antioxidant 168 in different proportions, such as antioxidant 215, antioxidant 225, etc.

[0059] Preferably, the initiators in step (A1) and step (B1) independently include any one of organic peroxides, persulfates, azo initiators, and photoinitiators, or a combination of at least two of them.

[0060] Preferably, the organic peroxide comprises diisobutyryl peroxide, benzoyl peroxide, bis(2-ethylhexyl) peroxydicarbonate, diisopropyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxypivalate, tert-butyl peroxypivalate, t-pentyl peroxypivalate, dilauroyl peroxide, di(3,3,5-trimethylacetyl) peroxide, 2,5-dimethyl-2,5-di(2-ethylacetyl peroxide)hexane, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl) peroxide, 2-(2-ethylhexanoate) peroxide, di(4-methylbenzoyl) peroxide, di(2 ... Any one of tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, 1,1-di-tert-butyl peroxy-3,3,5-trimethylcyclohexane, 1,1-di-tert-pentyl peroxycyclohexane, 1,1-di-tert-butyl peroxycyclohexane, di-tert-butyl peroxide, di-tert-pentyl peroxide, diisopropylbenzene peroxide, 2,5-di-tert-butyl peroxide-2,5-dimethylhexane, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-butyl peroxymaleate, and tert-butyl peroxy-2-ethylhexyl carbonate, or a combination of at least two thereof.

[0061] Preferably, the persulfate includes any one of sodium persulfate, potassium persulfate, and ammonium persulfate, or a combination of at least two of them.

[0062] Preferably, the azo initiator includes any one of azobisisobutyronitrile, azobisisoheptanenitrile, azobisisobutyramidine hydrochloride, azobisisobutylimidazoline hydrochloride, and azoisobutylcyanoformamide, or a combination of at least two thereof.

[0063] It should be noted that the present invention does not have any special restrictions on the specific selection of the photoinitiator, and all commonly used photoinitiators in the art are applicable.

[0064] Preferably, the flocculants in step (A3) and step (B3) independently include any one of polyacrylamide flocculants, starch flocculants, and chitosan flocculants, or a combination of at least two of them, more preferably polyacrylamide flocculants, and further preferably anionic polyacrylamide and / or nonionic polyacrylamide.

[0065] In method I, the hypophosphite preferably comprises sodium hypophosphite and / or potassium hypophosphite, and the resulting sodium diethylphosphinate aqueous solution and / or potassium diethylphosphinate aqueous solution are preferably used.

[0066] It should be noted that the hypophosphite may be anhydrous hypophosphite and / or hypophosphite hydrate.

[0067] Preferably, the hypophosphite is sodium hypophosphite, and the aqueous solution of sodium diethylphosphinate is obtained in step (A1).

[0068] Preferably, the mass percentage of hypophosphite in the hypophosphite aqueous solution in step (A1) is 10-60%, for example, it can be 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% or 55%, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and 30-40% is further preferred.

[0069] Preferably, the mass ratio of the hypophosphite to the antioxidant in step (A1) is 100:(0.02-1.2), for example, it can be 100:0.04, 100:0.05, 100:0.06, 100:0.08, 100:0.1, 100:0.2, 100:0.3, 100:0.4, 100:0.5, 100:0.6, 100:0.7, 100:0.8, 100:0.9, 100:0.95, 100:1, 100:1.05, 100:1.1 or 100:1.15, and more preferably 100:(0.05-1).

[0070] Preferably, in step (A1), the mass ratio of the hypophosphite to the initiator is 100:(0.1-5), for example, it can be 100:0.2, 100:0.5, 100:1, 100:1.5, 100:2, 100:2.5, 100:3, 100:3.5, 100:4, 100:4.5 or 100:4.8, etc.

[0071] It should be noted that the initiator in step (A1) can be added all at once, in batches, or continuously during the reaction; and a portion of the initiator in step (A1) can be added in advance, and the rest can be added continuously during the reaction.

[0072] Preferably, in step (A1), the molar ratio of ethylene to hypophosphite is (2-2.1):1, for example, it can be 2.01:1, 2.02:1, 2.04:1, 2.05:1, 2.06:1, 2.08:1 or 2.09:1, etc.

[0073] Preferably, the free radical reaction in step (A1) is carried out in a protective atmosphere.

[0074] Preferably, the protective atmosphere includes a nitrogen atmosphere and / or an argon atmosphere.

[0075] Preferably, the temperature of the free radical reaction in step (A1) is 70-120°C, for example, it can be 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or 115°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, more preferably 80-110°C, and further preferably 90-105°C.

[0076] The free radical reaction in step (A1) is carried out in the presence of an initiator. When the pressure of the reaction system substantially stops changing, the reaction is considered complete and the reaction is stopped.

[0077] Preferably, the time of the free radical reaction in step (A1) is 2-16 h, for example, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 or 15 h, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention no longer exhaustively enumerates the specific points included in the range.

[0078] In the present invention, the metal salt in step (A2) is a water-soluble metal salt. Preferably, the metal salt includes metal sulfate and / or metal chloride, more preferably metal sulfate.

[0079] Preferably, the metal in the metal salt in step (A2) includes any one of Al, Ca, Cu, Zn, Fe, Ti or a combination of at least two thereof, and Al is more preferred.

[0080] Preferably, the metal salt in step (A2) comprises aluminum sulfate.

[0081] It should be noted that the metal salt may be an anhydrous metal salt and / or a metal salt hydrate.

[0082] Preferably, the mass percentage of the metal salt in the metal salt aqueous solution in step (A2) is 20-40%, for example, it can be 22%, 25%, 28%, 30%, 32%, 35% or 38%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0083] Preferably, the molar ratio of the metal salt to diethylphosphinate in step (A2) is 1:(5.8-6.2), for example, 1:5.82, 1:5.85, 1:5.88, 1:5.9, 1:5.92, 1:5.95, 1:5.98, 1:6, 1:6.02, 1:6.05, 1:6.08, 1:6.1, 1:6.12, 1:6.15 or 1:6.18, etc., more preferably 1:6.

[0084] In the present invention, the pH value of the reaction system in step (A2) is 3.5-3.8, for example, it can be 3.52, 3.55, 3.58, 3.6, 3.62, 3.65, 3.68, 3.7, 3.72, 3.75 or 3.78, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0085] Preferably, the alkali solution in step (A2) comprises sodium hydroxide solution and / or potassium hydroxide solution.

[0086] The present invention does not have any special restrictions on the mass concentration of the sodium hydroxide solution and the potassium hydroxide solution. It only needs to add the sodium hydroxide solution and / or the potassium hydroxide solution to maintain the pH of the reaction system obtained in step (A2) at 3.5-3.8.

[0087] Preferably, the reaction temperature in step (A2) is 20-80°C, for example, it can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C or 75°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and it is further preferably 40-60°C.

[0088] Preferably, the reaction time of step (A2) is 0.1-5 h, for example, 0.2 h, 0.5 h, 0.8 h, 1 h, 1.2 h, 1.5 h, 1.8 h, 2 h, 2.2 h, 2.5 h, 2.8 h, 3 h, 3.2 h, 3.5 h, 3.8 h, 4 h or 4.5 h, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention no longer exhaustively enumerates the specific points included in the range.

[0089] It should be noted that in step (A2) of the present invention, the metal salt aqueous solution and the alkali solution are simultaneously added to the diethylphosphinate aqueous solution for reaction, or the metal salt aqueous solution, the alkali solution and the diethylphosphinate aqueous solution are continuously added to a reaction device (such as a stirred reactor, a static mixer, a dynamic mixer) at a constant flow rate for sufficient mixing reaction. Wherein, when the metal salt aqueous solution and the alkali solution are simultaneously added to the diethylphosphinate aqueous solution for reaction, the reaction temperature is 20-80°C, preferably 30-70°C, and more preferably 40-60°C, and the dropwise addition time of the metal salt aqueous solution and the alkali solution is 0.1-5 h (for example, 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, etc.), preferably 0.5-3 h, and more preferably 1 h - 3 h; when the metal salt aqueous solution, the alkali solution and the diethylphosphinate aqueous solution are continuously added to the reaction container at a constant flow rate, the reaction temperature is 40-80°C, preferably 50-60°C, and the reaction space velocity is 0.1-2 / h (for example, 0.2 / h, 0.5 / h, 0.8 / h, 1 / h, 1.2 / h, 1.5 / h, 1.8 / h, etc.), preferably 0.3-1 / h, and more preferably 0.5-0.8 / h.

[0090] Preferably, in step (A3), based on the theoretical mass of the metal diethylphosphinate as 100%, the mass of the flocculant is 0.01-0.5%, for example, it can be 0.02%, 0.05%, 0.08%, 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, 0.22%, 0.25%, 0.28%, 0.3%, 0.32%, 0.35%, 0.38%, 0.4%, 0.42%, 0.45% or 0.48%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0091] The “theoretical mass of the metal salt of diethylphosphinate” is calculated based on the input amounts of the diethylphosphinate and the metal salt in step (A2).

[0092] Preferably, the flocculant and water are first mixed at 20-30° C. for 10-20 min to obtain a flocculant solution, and then the flocculant solution is mixed with the diethylphosphinate metal salt slurry and stirred. The mass ratio of the flocculant to water is 1:(10-1000), for example, 1:50, 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900 or 1:950, etc.

[0093] Preferably, the mixing temperature in step (A3) is 40-60°C, for example, it can be 42°C, 44°C, 46°C, 48°C, 50°C, 52°C, 54°C, 56°C or 58°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0094] Preferably, the number of washing in step (A3) is ≥ 4 times, for example, it can be 5 times, 6 times, 7 times, 8 times, 9 times, 10 times or 12 times, and more preferably 5-10 times.

[0095] Preferably, the washing agent used in the washing is water.

[0096] As a preferred technical solution of the present invention, the diethylphosphinate metal salt flocculent is filtered and then washed multiple times, the number of washings being ≥4 times, preferably 5-10 times, so as to better remove impurities and acidic substances in the product and obtain the polymer additive with low acid value and better thermal stability.

[0097] Preferably, the mass ratio of water to solids in each washing is independently (1-10):1, for example, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, etc., and more preferably (1.5-6):1. The solids are the solid products obtained by filtration.

[0098] Preferably, the drying temperature in step (A3) is 105-250°C, for example, it can be 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 180°C, 200°C, 220°C or 240°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and 110-150°C is further preferred.

[0099] As a preferred technical solution of the present invention, the method I specifically comprises the following steps:

[0100] (A1) in a protective gas atmosphere, reacting a hypophosphite aqueous solution and an antioxidant with ethylene in the presence of an initiator to obtain a diethylphosphinate aqueous solution;

[0101] The mass percentage of hypophosphite in the hypophosphite aqueous solution is 10-60%, and the mass ratio of hypophosphite, antioxidant and initiator is 100:(0.02-1.2):(0.1-5); the temperature of the free radical reaction is 70-120° C., and the reaction is terminated when the pressure of the system no longer changes;

[0102] (A2) mixing the diethylphosphinate aqueous solution, the metal salt aqueous solution and the alkali solution, and reacting them at a pH of 3.5-3.8 and a temperature of 40-60° C. to obtain a diethylphosphinate metal salt slurry;

[0103] Wherein, the molar ratio of the metal salt to diethylphosphinate is 1:(5.9-6.1), and the mass percentage of the metal salt in the metal salt aqueous solution is 20-40%;

[0104] (A3) mixing the diethylphosphinate metal salt slurry and the flocculant solution at 40-60° C., stirring to obtain diethylphosphinate metal salt flocs; filtering the diethylphosphinate metal salt flocs, washing ≥4 times, and drying to obtain the polymer additive;

[0105] Wherein, based on the theoretical mass of the diethylphosphinate metal salt being 100%, the mass of the flocculant is 0.01-0.5%.

[0106] Preferably, the mass percentage of hypophosphorous acid in the hypophosphorous acid aqueous solution in step (B1) is 20-70%, for example, it can be 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60% or 65%, and specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and 45-55% is further preferred.

[0107] Preferably, the mass ratio of the hypophosphorous acid to the antioxidant in step (B1) is 100:(0.02-1.2), for example, it can be 100:0.04, 100:0.05, 100:0.06, 100:0.08, 100:0.1, 100:0.2, 100:0.3, 100:0.4, 100:0.5, 100:0.6, 100:0.7, 100:0.8, 100:0.9, 100:0.95, 100:1, 100:1.05, 100:1.1 or 100:1.15, and more preferably 100:(0.05-1).

[0108] Preferably, in step (B1), the mass ratio of hypophosphorous acid to initiator is 100:(0.1-5), for example, it can be 100:0.2, 100:0.5, 100:1, 100:1.5, 100:2, 100:2.5, 100:3, 100:3.5, 100:4, 100:4.5 or 100:4.8, etc.

[0109] It should be noted that the initiator in step (B1) of the present invention can be added all at once, in batches, or continuously during the reaction process; and a portion of the initiator in step (B1) can be added in advance, and the rest can be added continuously during the reaction process.

[0110] Preferably, in step (B1), the molar ratio of ethylene to hypophosphorous acid is (2-2.1):1, for example, it can be 2.01:1, 2.02:1, 2.04:1, 2.05:1, 2.06:1, 2.08:1 or 2.09:1.

[0111] Preferably, the free radical reaction in step (B1) is carried out in a protective atmosphere.

[0112] Preferably, the protective atmosphere includes a nitrogen atmosphere and / or an argon atmosphere.

[0113] Preferably, the temperature of the free radical reaction in step (B1) is 60-105°C, for example, it can be 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 98°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, more preferably 70-100°C, and further preferably 75-95°C.

[0114] The free radical reaction in step (B1) is carried out in the presence of an initiator. When the pressure of the reaction system substantially stops changing, the reaction is considered complete and the reaction is stopped.

[0115] Preferably, the time of the free radical reaction in step (B1) is 2-16 h, for example, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 or 15 h, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention no longer exhaustively enumerates the specific points included in the range.

[0116] Preferably, the metal hydroxide in step (B2) comprises any one of aluminum hydroxide, calcium hydroxide, copper hydroxide, zinc hydroxide, iron hydroxide, titanium hydroxide or a combination of at least two thereof, more preferably aluminum hydroxide.

[0117] Preferably, the iron hydroxide includes ferrous hydroxide and / or ferric hydroxide.

[0118] By using the above metal hydroxide, the cation in the diethylphosphinate obtained in step (B2) includes any one of Al, Ca, Cu, Zn, Fe or Ti, more preferably Al.

[0119] Preferably, in step (B2), based on the molar amount of the diethylphosphinic acid as 100%, the molar amount of the metal hydroxide is 30-50 mol%, for example, it can be 32 mol%, 33 mol%, 33.3 mol%, 34 mol%, 35 mol%, 36 mol%, 38 mol%, 40 mol%, 42 mol%, 45 mol% or 48 mol%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0120] Preferably, in step (B2), based on the molar amount of the diethylphosphinic acid as 100%, the molar amount of the sulfuric acid is 5-50 mol%, for example, it can be 8 mol%, 10 mol%, 12 mol%, 15 mol%, 18 mol%, 20 mol%, 22 mol%, 25 mol%, 28 mol%, 30 mol%, 32 mol%, 35 mol%, 38 mol%, 40 mol%, 42 mol%, 45 mol% or 48 mol%, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and 8-30 mol% is further preferred, and 10-15 mol% is more preferred.

[0121] Preferably, the reaction temperature in step (B2) is 70-150°C, for example, it can be 75°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 145°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and further preferably 80-120°C, more preferably 90-100°C.

[0122] Preferably, the reaction time of step (B2) is 2-12 h, for example, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h or 11.5 h, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention no longer exhaustively enumerates the specific points included in the range.

[0123] In the present invention, the pH value of the diethylphosphinate slurry in step (B2) is 3.8-4.2, for example, it can be 3.82, 3.85, 3.88, 3.9, 3.92, 3.95, 3.98, 4, 4.02, 4.05, 4.08, 4.1, 4.12, 4.15 or 4.18, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0124] Preferably, the alkali solution in step (B2) comprises sodium hydroxide solution and / or potassium hydroxide solution.

[0125] The present invention does not have any special restrictions on the mass concentration of the sodium hydroxide solution and the potassium hydroxide solution. It only needs to add the sodium hydroxide solution and / or the potassium hydroxide solution to maintain the pH of the diethylphosphinate slurry obtained in step (B2) at 3.8-4.2.

[0126] Preferably, in step (B3), based on the theoretical mass of the diethylphosphinate as 100%, the mass of the flocculant is 0.01-0.5%, for example, it can be 0.02%, 0.05%, 0.08%, 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, 0.22%, 0.25%, 0.28%, 0.3%, 0.32%, 0.35%, 0.38%, 0.4%, 0.42%, 0.45% or 0.48%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0127] The “theoretical mass of diethylphosphinate” is calculated based on the input amounts of diethylphosphinate and metal hydroxide in step (B2).

[0128] Preferably, the flocculant and water are first mixed at 20-30° C. for 10-20 min to obtain a flocculant solution, and then the flocculant solution is mixed with the diethylphosphinate slurry and stirred. The mass ratio of the flocculant to water is 1:10-1000, for example, 1:50, 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900 or 1:950, etc.

[0129] Preferably, the mixing temperature in step (B3) is 40-60°C, for example, it can be 42°C, 44°C, 46°C, 48°C, 50°C, 52°C, 54°C, 56°C or 58°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0130] Preferably, the number of washing in step (B3) is ≥ 4 times, for example, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times or 12 times, etc., more preferably 5-10 times.

[0131] Preferably, the washing agent used in the washing is water.

[0132] Preferably, the mass ratio of water to solids in each washing is independently (1-10):1, for example, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, etc., and more preferably (1.5-6):1. The solids are the solid products obtained by filtration.

[0133] Preferably, the drying temperature in step (B3) is 105-250°C, for example, it can be 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 180°C, 200°C, 220°C or 240°C, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and 110-150°C is further preferred.

[0134] As a preferred technical solution of the present invention, the method II specifically comprises the following steps:

[0135] (B1) In a protective gas atmosphere, an aqueous solution of hypophosphorous acid and an antioxidant react with ethylene under the action of an initiator to produce an aqueous solution of diethylphosphinic acid;

[0136] The mass concentration of the hypophosphorous acid aqueous solution is 20-70%, and the mass ratio of hypophosphorous acid, antioxidant and initiator is 100:(0.02-1.2):(0.1-5); the temperature of the free radical reaction is 60-100° C., and the reaction is terminated when the pressure of the system no longer changes;

[0137] (B2) reacting the diethylphosphinic acid aqueous solution, sulfuric acid and metal hydroxide at 70-150° C. for 2-12 h, and then adding alkali solution to adjust the pH of the system to 3.8-4.2 to obtain a diethylphosphinic acid salt slurry;

[0138] Wherein, based on the molar amount of the diethylphosphinic acid as 100%, the molar amount of the metal hydroxide is 30-50 mol%, and the molar amount of the sulfuric acid is 5-50 mol%;

[0139] (B3) mixing the diethylphosphinate slurry and the flocculant solution at 40-60° C., stirring to obtain diethylphosphinate flocs; filtering the diethylphosphinate flocs, washing ≥4 times, and drying to obtain the polymer additive;

[0140] Wherein, based on the theoretical mass of the diethylphosphinate being 100%, the mass of the flocculant is 0.01-0.5%.

[0141] It should be noted that the preparation method of the polymer additive proposed in the present invention is not limited to the aforementioned method I and method II, and those skilled in the art may also select other methods or routes to obtain the polymer additive with a low acid value proposed in the present invention.

[0142] In a third aspect, the present invention provides a use of the polymer additive as described in the first aspect in a polymer material.

[0143] Preferably, the polymer additive is applied to the polymer material as a flame retardant.

[0144] Preferably, the polymer material comprises any one of polyamide, polyester, polyurethane, styrene-based polymer, polyolefin, polyphenylene ether, polyacrylate or a combination of at least two thereof, more preferably polyamide and / or polyester.

[0145] In a fourth aspect, the present invention provides a polymer composition, comprising a polymer matrix and the polymer additive as described in the first aspect.

[0146] Preferably, the polymer composition comprises the following components in parts by mass:

[0147] Polymer matrix 40-99 parts

[0148] The polymer additive is 5-35 parts.

[0149] Preferably, the mass parts of the polymer matrix are 40-99 parts, for example, they can be 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, 95 parts or 98 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0150] Preferably, the mass percentage of the polymer matrix in the polymer composition is ≥35%, for example, it can be 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0151] Preferably, the mass parts of the polymer additive are 5-35 parts, for example, they can be 6 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts or 34 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0152] Preferably, the mass percentage of the polymer additive in the polymer composition is ≥3%, for example, it can be 5%, 6%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32% or 35%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 6%-20% is further preferred.

[0153] Preferably, the polymer matrix comprises polyamide and / or polyester.

[0154] Preferably, the polyamide includes any one of polyamide resin and polyamide elastomer, or a combination of at least two of them.

[0155] As a polyamide, it includes any one or a combination of at least two of the condensation products of dicarboxylic acids and diamines, condensation products of ω-amino acids, and ring-opening polymerization products of cyclic lactams. The dicarboxylic acids exemplarily include but are not limited to: any one or a combination of at least two of adipic acid, sebacic acid, dodecanedioic acid, terephthalic acid, and isophthalic acid. The diamines exemplarily include but are not limited to: any one or a combination of at least two of pentamethylenediamine, hexamethylenediamine, decanediamine, dodecanediamine, butanediamine, p-phenylenediamine, and m-phenylenediamine. The cyclic lactams exemplarily include but are not limited to: any one or a combination of at least two of caprolactam, capryllactam, undecane lactam, and lauryl lactam. The ω-amino acids exemplarily include but are not limited to: any one or a combination of at least two of the ω-amino acids and aminobenzoic acids formed by the ring opening of the aforementioned cyclic lactams.

[0156] Preferably, the polyamide includes any one of polyamide 6 (polycaprolactam), polyamide 11 (polyundecalactam), polyamide 12 (polydodecalactam), polyamide 56 (polypentamethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610 (polyhexamethylene sebacamide), polyamide 612 (polyhexamethylene dodecane diamide), polyamide 1010 (polydecanediamide), polyamide 1012 (polydecanediamide), polyamide 1212 (polydodecane diamide), polyamide 6T (polyhexamethylene terephthalamide), polyamide 10T (polydecanediamide), and PPA (polyparaphenylene terephthalamide), or a combination of at least two thereof.

[0157] Preferably, the polyester comprises a condensation product of a dicarboxylic acid and / or its derivatives and a diol, wherein the dicarboxylic acid exemplarily includes but is not limited to: any one or a combination of at least two of terephthalic acid, isophthalic acid, phthalic acid, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, cyclohexanedicarboxylic acid, hydrogenated isophthalic acid, hydrogenated phthalic acid, and the derivatives include acyl halides (chlorides), esters, anhydrides, etc. formed by dicarboxylic acids. The diol exemplarily includes but is not limited to: any one or a combination of at least two of ethylene glycol, butanediol, and hexanediol.

[0158] Exemplarily, the polyester includes polyethylene terephthalate (PET) and / or polybutylene terephthalate (PBT).

[0159] It should be noted that the polymer composition of the present invention may also include any other fillers, other additives, etc. that are added with motivation in the art.

[0160] Preferably, the polymer composition further comprises reinforcing materials and / or fillers.

[0161] Preferably, the reinforcing material comprises glass fiber and / or carbon fiber.

[0162] Preferably, the mass fraction of the reinforcing material in the polymer composition is ≤45 parts, and the mass fraction of the reinforcing material can be 0, 0.5, 1, 2, 5, 8, 10, 15, 20, 25, 30, 35, 40, 42 or 44 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0163] Preferably, the filler includes any one of silicon dioxide, talc, titanium dioxide, barium sulfate, kaolin, calcium sulfate, boehmite, mica, magnesium carbonate, and glass microspheres, or a combination of at least two thereof.

[0164] Preferably, the mass fraction of filler in the polymer composition is ≤40 parts, and the mass fraction of filler can be 0, 0.5, 1, 2, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35 or 38 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0165] Preferably, the polymer composition further includes 0-15 parts by mass of other additives, and the mass parts of the other additives can be 0, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12 or 14 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0166] Preferably, the other additives include any one of an antioxidant, an ultraviolet absorber, a lubricant, a nucleating agent, a stabilizer, an antistatic agent, and a colorant, or a combination of at least two of them.

[0167] Preferably, the polymer composition further comprises any one of an antioxidant, an ultraviolet absorber, a lubricant, a nucleating agent, a stabilizer, an antistatic agent, and a colorant, or a combination of at least two thereof.

[0168] Preferably, the weight parts of antioxidant, ultraviolet absorber, lubricant and nucleating agent in the polymer composition are each independently 0.01-1.5 parts, for example, 0.05 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 parts, 1.2 parts or 1.4 parts, as well as specific points between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0169] Preferably, the antioxidant in the polymer composition includes any one of a hindered amine antioxidant, a hindered phenol antioxidant, a phosphite antioxidant, and a thioester antioxidant, or a combination of at least two thereof.

[0170] Exemplarily, the antioxidant in the polymer composition includes any one of tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) pentaerythritol ester (antioxidant 1010), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl) hexanediamine (antioxidant 1098), tris(2,4-di-tert-butylphenyl)phosphite (antioxidant 168), bis(2,4-dicumylphenyl)pentaerythritol diphosphite (antioxidant 608), 2,6-di-tert-butyl-p-cresol (antioxidant BHT), β,β-distearyl thiodipropionate (antioxidant DSTP), antioxidant 215, and antioxidant 225, or a combination of at least two thereof.

[0171] Preferably, the lubricant includes any one of ester lubricants, alcohol lubricants, hydrocarbon lubricants, fatty acid lubricants, fatty acid amide lubricants, and metal soap lubricants, or a combination of at least two of them.

[0172] Preferably, the polymer composition further comprises a synergistic flame retardant.

[0173] Preferably, the mass ratio of the polymer additive to the synergistic flame retardant is 1:(0.1-5), for example, it can be 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.5, 1:3, 1:3.5, 1:4 or 1:4.5, etc., further preferably 1:(0.1-1), and more preferably 1:(0.1-0.5).

[0174] Preferably, the polymer composition further includes 0-18 parts by mass of a synergistic flame retardant, and the mass percentage of the synergistic flame retardant can be 0, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15 or 16 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0175] Preferably, the synergistic flame retardant includes any one of melamine derivatives, zinc borate, zinc stannate, zinc sulfide, and boehmite, or a combination of at least two thereof.

[0176] Preferably, the melamine derivative includes any one of polyphosphate melamine salt, polyphosphate melamine, and melam, or a combination of at least two of them.

[0177] In a preferred technical solution, the polymer composition comprises the following components in parts by mass:

[0178] Polymer matrix 40-99 parts

[0179] 5-35 parts of the polymer additive

[0180] Reinforcement material 0-45 parts

[0181] Synergistic flame retardant 0-18 parts

[0182] Lubricant 0-1.5 parts

[0183] Antioxidant 0-1.5 parts.

[0184] Illustratively, the method for preparing the polymer composition comprises: melt-blending the components of the polymer composition and then extruding to obtain the polymer composition.

[0185] Preferably, the melt blending is carried out in a screw extruder.

[0186] Preferably, the screw extruder is a twin-screw extruder.

[0187] Preferably, the temperature of the screw extruder is 180-330°C, for example, it can be 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C or 320°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0188] Preferably, the extrusion further includes granulation and drying steps.

[0189] Compared with the prior art, the present invention has the following beneficial effects:

[0190] The polymer additive provided by the present invention comprises a combination of diethyl phosphinate, ethyl butyl phosphinate, ethyl phosphonate and monoethyl phosphinate, and has low acidity. When the polymer additive is used as a flame retardant in a polymer composition, it can slow down the occurrence of high-temperature decomposition of dialkyl phosphinic acid, so that the polymer composition has a lower content of boiled precipitates, improves its use stability under hot and humid conditions, prolongs its service life, and generates less mold deposit during the injection molding process, which can improve the injection molding production efficiency and improve the appearance of the product. DETAILED DESCRIPTION

[0191] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0192] As used herein, the terms "comprises," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0193] In the following specific implementation manner, the testing method of the polymer additive is as follows:

[0194] (1) Content test of diethylphosphinate, ethylbutylphosphinate, ethylphosphonate and monoethylphosphinate

[0195] The results were obtained by liquid chromatography (LC20A, Shimadzu, Japan), wherein diethyl phosphinate was obtained by commercial standard, ethyl butyl phosphinate was obtained by its pure product (prepared by referring to Example 4 of CN103172668A) as standard, ethyl phosphonate was obtained by its pure product (prepared by referring to Example 2 of CN104371142A) as standard, and monoethyl phosphinate was obtained by its pure product (prepared by referring to Example 1 of CN103172668A) as standard; the sample to be tested was dissolved in a sulfuric acid aqueous solution (mass concentration 30%) 5 times the mass of the sample, and then diluted 20 times with a mobile phase for analysis and testing; the mobile phase was a mixture of water and methanol in a mass ratio of 9:1, and trifluoroacetic acid with a volume content of 0.5% was added, the chromatographic column was ShimNex CS C18 5μm, 4.6×250 mm, and the flow rate was 0.6 mL / min; the mass content of each component was calculated by the area normalization method.

[0196] (2) Content of alkali-insoluble matter

[0197] Take 5 g of the sample to be tested, stir it with 500 g of sodium hydroxide aqueous solution (mass concentration 3%) at 35°C for 30 min, filter it with filter paper with a precision of ≤2 μm, and rinse it with 100 g of water for 3 times. After the filter paper is dried, weigh it. The mass increase relative to the mass before filtration (dry filter paper) is the mass of insoluble matter, and the ratio of the mass of insoluble matter to the mass of the sample to be tested (5 g) is the mass content of alkali-insoluble matter.

[0198] (3) Content of other phosphorus-containing compounds

[0199] The sample to be tested is mixed with a deuterated aqueous solution of deuterated sodium hydroxide (mass concentration 10%) at a mass ratio of 1:30 to completely dissolve the sample, filter it, and measure the nuclear magnetic phosphorus spectrum of the resulting clear liquid by a nuclear magnetic resonance instrument (NMR, Bruker nuclear magnetic resonance NMR spectrometer, AVANCENEO 400 MHz). The nuclear magnetic phosphorus spectrum is integrated, and the integrated area ratio of other peaks except the known diethyl phosphinate, ethyl butyl phosphinate, ethyl phosphonate, and monoethyl phosphinate is regarded as the content of the other phosphorus-containing compounds.

[0200] (4) Water-soluble acid value

[0201] Take 1 g of the sample to be tested and add 5.00 ± 0.01 g (m 乙醇 ) ethanol evenly wetted, add 50 ± 0.01 g (m 水 ) Room temperature water, with bottle and stirring weighing total weight m 01 , boiled in a sealed water container at 90℃ for 1 h, cooled to 25℃ and kept at constant temperature for 30 min, and then supplemented with ethanol aqueous solution (the mass ratio of ethanol to water was 1:10) to a total weight of m 01 . Filter and obtain the filtrate with a mass of m11 The filtrate was tested by potentiometric titration to determine the acid value (m 水 +m 乙醇 ), wherein the concentration of potassium hydroxide solution used for titration is 0.05 mol / L, and the water-soluble acid value of polymer additive = test acid value × (m 水 +m 乙醇 ) / m 11 -Blank acid value.

[0202] (5) Organic acid value

[0203] Take 1 g of the sample to be tested and add 50.0±0.01 g (m 二氯甲烷 ) After being uniformly moistened in dichloromethane, weigh the total weight m with bottle and stirring 02 , boiled in a sealed container at 90℃ for 1 h, cooled to 25℃ and kept at constant temperature for 30 min, and then added with dichloromethane to a total weight of m 02 ; Filter, and the mass of the clear filtrate is m 12 The filtrate is tested by potentiometric titration to determine the acid value, and the weight is determined by potentiometric titration to determine the m 二氯甲烷 The blank acid value of the test sample is 0.05 mol / L, where the concentration of the potassium hydroxide solution used for titration is 0.05 mol / L. The organic acid value of the polymer additive = test acid value × m 二氯甲烷 / m 12 -Blank acid value.

[0204] (6) Sulfate mass content

[0205] Referring to the method in standard EN 14582:2007-Determination of halogen content, the measurement was carried out using ion chromatography technology and external standard method.

[0206] In the following specific embodiments of the present invention, all materials for which no preparation method is provided are commercially available chemicals, and the specific information of some materials is as follows:

[0207]

[0208] The polymer additive and the preparation method thereof of the present invention will be described in detail below by taking a plurality of embodiments as examples, but the polymer additive and the preparation method thereof are not limited to these embodiments.

[0209] Examples 1-5, Comparative Examples 1-6

[0210] A polymer additive and a preparation method thereof, wherein the preparation method is as follows:

[0211] (1) Mix 31.8 kg solid sodium hypophosphite monohydrate, 50 kg water, 500 g sodium persulfate, and a mass of m 1The antioxidant 1010 and the mass m 2 The antioxidant 168 was put into an autoclave, and the atmosphere was replaced with nitrogen for 3 times. The ethylene pressure was kept constant at 1.5 MPa by a pressure reducer, and the autoclave was heated to 95°C and kept warm for 4 h. 2500 g of a 20% sodium persulfate aqueous solution was continuously added during the 4 h of keeping warm. The autoclave was then kept warm at 95°C for 1 h, cooled and vented to obtain a sodium diethylphosphinate aqueous solution.

[0212] (2) diluting the sodium diethylphosphinate aqueous solution obtained in step (1) to a mass content of 20% sodium diethylphosphinate (containing 6 mol of sodium diethylphosphinate), and heating to a temperature T 1 , continuously dripping an aluminum sulfate aqueous solution (aluminum sulfate 18-hydrate is 1 mol, with a mass content of 28%) within 1 hour, and controlling the pH value with a potassium hydroxide solution (with a mass content of 5%), to obtain a diethyl aluminum phosphinate slurry;

[0213] (3) Adding a mixture of m 3 A flocculant aqueous solution prepared by mixing 50 g of anionic polyacrylamide and 50 g of water was stirred until flocculated, filtered, and the filter cake was washed n times with 3 times the mass of water, and dried at 120°C to constant weight to obtain a polymer additive.

[0214] The specific process parameters of the preparation method and the relevant data of the prepared polymer additive are shown in Table 1.

[0215] Table 1

[0216]

[0217] Examples 6-8, Comparative Examples 7-10

[0218] A polymer additive and a preparation method thereof, wherein the preparation method is as follows:

[0219] (1) 39.6 kg of 50% hypophosphorous acid aqueous solution, 500 g of sodium persulfate, and a mass of m 4 The antioxidant was put into an autoclave, and the atmosphere was replaced with nitrogen three times. The ethylene pressure was kept constant at 1.5 MPa by a pressure reducer, and the autoclave was heated to 85°C and kept warm for 5.5 hours. 3500 g of a 10% sodium persulfate aqueous solution was continuously added during the heat preservation process, and then the autoclave was kept warm at 85°C for 1.5 hours, cooled and vented to obtain a diethylphosphinic acid aqueous solution.

[0220] (2) The diethylphosphinic acid aqueous solution (6 mol of diethylphosphinic acid) obtained in step (1), the sulfuric acid aqueous solution (the mass content of sulfuric acid is 30%, the molar amount is 0.6 mol) and 2 mol of aluminum hydroxide are mixed, heated to 90° C. and stirred for reaction for 8 h, and the pH value is adjusted with a sodium hydroxide solution (mass content is 10%) to obtain a diethylphosphinic acid aluminum slurry;

[0221] (3) Adding a mixture of m 5 A flocculant aqueous solution prepared with 50 g of anionic polyacrylamide and 50 g of water was stirred to form diethyl aluminum phosphinate floccules, filtered, and the filter cake was washed 5 times with 3 times the mass of water, and dried at 110°C to constant weight to obtain a polymer additive.

[0222] The specific process parameters of the preparation method and the relevant data of the prepared polymer additive are shown in Table 2; "--" means that the material is not added.

[0223] Table 2

[0224]

[0225] Combining Table 1 and Table 2, it can be seen that the polymer additives provided in Examples 1-8 of the present invention all have relatively low acid values, and their water-soluble acid values ​​are 0.1-0.3 mg KOH / g, while the polymer additives provided in Comparative Examples 1-10 have significantly higher acid values.

[0226] The application of the polymer additive of the present invention will be described in detail below using application examples, but the application of the polymer additive is not limited to these application examples.

[0227] In the following application examples, the materials for which the preparation methods are not provided are all commercially available chemicals. The specific information is as follows:

[0228]

[0229] Application examples 1-8, comparative application examples 1-10

[0230] A polymer composition, specifically a polyamide composition, the types and amounts of the components are shown in Table 3 and Table 4, and the units of the amounts of the components are all "parts by mass".

[0231] The preparation method of the polyamide composition comprises: mixing polyamide 66, polyamide 6, glass fiber, polymer additive, MPP, antioxidant and lubricant according to the formula amount to obtain a premix; adding the premix to a twin-screw extruder, the screw speed of the twin-screw extruder is 380 rpm, the temperatures of zones 1-12 are 90° C., 180° C., 260° C., 250° C., 230° C., 230° C., 220° C., 220° C., 220° C., 220° C., 260° C., and 260° C. respectively, and obtaining polyamide composition particles through melt mixing and extrusion granulation.

[0232] The following performance tests were performed on the polyamide composition:

[0233] (1) Boiling phosphorus content test: Take 50 g of polyamide composition particles, add them into 500 mL of 90°C hot water, boil for 1 h, cool to room temperature, filter, and measure the phosphorus content of the filtrate using the ammonium molybdate spectrophotometric method in accordance with GB / T 11893-1989;

[0234] (2) Mold deposit test method: Using an injection molding machine, the polyamide composition pellets are continuously injected for 150 times at injection temperatures of 290°C, 285°C, 280°C, and 260°C. The mold deposit sample collected from the last mold is taken out and weighed using an analytical balance.

[0235] The test data are shown in Table 3 and Table 4.

[0236] Table 3

[0237]

[0238] Table 4

[0239]

[0240] According to the data in Table 3, the polymer additive with a low acid value provided by the present invention is used as a flame retardant in a polyamide composition, which can significantly reduce the mold deposit generated by injection molding, making the mold deposit ≤5.6 mg, and the water-boiled phosphorus content of the polyamide composition ≤464 ppm, thereby reducing the content of water-boiled precipitates and improving the stability and service life of the polyamide composition under hot and humid conditions.

[0241] According to the test data in Table 4, due to the high acid value of the polymer additives in Comparative Examples 1-10, when used as flame retardants in polyamide compositions, more injection mold deposits are produced, the water-boiled phosphorus content is increased, and the stability under hot and humid conditions is obviously insufficient.

[0242] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the polymer additive and preparation method and polymer composition of the present invention, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A polymer additive, characterized in that The polymer additive comprises the following components in parts by mass: 95-99.88 parts of diethylphosphinate Ethyl butyl phosphinate 0.1-3 parts Ethylphosphonate 0.01-1 part 0.01-1 part of monoethylphosphinate; The water-soluble acid value of the polymer additive is 0.1-0.3 mg KOH / g.

2. The polymer additive according to claim 1, characterized in that The organic acid value of the polymer additive is ≤0.05 mg KOH / g; And / or, the mass content of sulfate in the polymer additive is 100-500 ppm.

3. The polymer additive according to claim 1, characterized in that The diethylphosphinate includes any one of diethylphosphinate aluminum, diethylphosphinate calcium, diethylphosphinate copper, diethylphosphinate zinc, diethylphosphinate iron, and diethylphosphinate titanium, or a combination of at least two thereof; And / or, the ethylbutylphosphinate includes any one of ethylbutylphosphinate aluminum, ethylbutylphosphinate calcium, ethylbutylphosphinate copper, ethylbutylphosphinate zinc, ethylbutylphosphinate iron, ethylbutylphosphinate titanium or a combination of at least two thereof; And / or, the ethylphosphonate includes any one of ethylphosphinate aluminum, ethylphosphinate calcium, ethylphosphinate copper, ethylphosphinate zinc, ethylphosphinate iron, ethylphosphinate titanium, or a combination of at least two thereof; And / or, the monoethylphosphinate includes any one of monoethylphosphinate aluminum, monoethylphosphinate calcium, monoethylphosphinate copper, monoethylphosphinate zinc, monoethylphosphinate iron, monoethylphosphinate titanium, or a combination of at least two thereof.

4. The polymer additive according to claim 1, characterized in that The polymer additive further includes an alkali-insoluble substance, which includes any one of hydroxides, oxides, phosphates, pyrophosphates, polyphosphates, and phosphites, or a combination of at least two thereof; And / or, the mass fraction of alkali-insoluble matter in the polymer additive is ≤3 parts.

5. A method for preparing a polymer additive according to any one of claims 1 to 4, characterized in that: The preparation method includes method I or method II; The method I comprises the following steps: (A1) a hypophosphite aqueous solution and an antioxidant react with ethylene in the presence of an initiator to obtain a diethylphosphinate aqueous solution; (A2) mixing the aqueous solution of diethylphosphinate obtained in step (A1), the aqueous solution of metal salt and alkaline solution, and reacting them at a pH value of 3.5-3.8 to obtain a diethylphosphinate metal salt slurry; (A3) mixing the diethylphosphinate metal salt slurry obtained in step (A2) with a flocculant, stirring, to obtain diethylphosphinate metal salt flocs; filtering, washing and drying the diethylphosphinate metal salt flocs to obtain the polymer additive; The method II comprises the following steps: (B1) the hypophosphorous acid aqueous solution and the antioxidant react with ethylene under the action of an initiator to produce a diethylphosphinic acid aqueous solution; (B2) reacting the aqueous solution of diethylphosphinic acid obtained in step (B1), sulfuric acid and a metal hydroxide, and then adding an alkali solution to obtain a diethylphosphinic acid salt slurry having a pH value of 3.8-4.2; (B3) mixing the diethylphosphinate slurry obtained in step (B2) with a flocculant, stirring, and obtaining diethylphosphinate flocs; filtering, washing, and drying the diethylphosphinate flocs to obtain the polymer additive.

6. The preparation method according to claim 5, characterized in that: The antioxidants in step (A1) and step (B1) independently include any one of hindered phenol antioxidants, hindered amine antioxidants, phosphite antioxidants, and thioester antioxidants, or a combination of at least two thereof; And / or, the initiators in step (A1) and step (B1) independently include any one of organic peroxides, persulfates, azo initiators, and photoinitiators, or a combination of at least two thereof; And / or, the flocculants in step (A3) and step (B3) each independently include polyacrylamide flocculants.

7. The preparation method according to claim 5, characterized in that: The temperature of the free radical reaction in step (A1) is 70-120°C; And / or, the reaction temperature in step (A2) is 20-80°C; And / or, the mixing temperature in step (A3) is 40-60°C; and / or, the number of washing in step (A3) is ≥ 4 times; and / or, the temperature of the free radical reaction in step (B1) is 60-105°C; And / or, the reaction temperature in step (B2) is 70-150°C; And / or, the mixing temperature in step (B3) is 40-60°C; And / or, the number of washing times in step (B3) is ≥ 4 times.

8. Use of the polymer additive according to any one of claims 1 to 4 in polymer materials.

9. A polymer composition, characterized in that The polymer composition comprises a polymer matrix and the polymer additive according to any one of claims 1 to 4.

10. The polymer composition according to claim 9, characterized in that The polymer composition comprises the following components in parts by mass: Polymer matrix 40-99 parts The polymer additive is 5-35 parts.

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