Polymer additive as well as preparation method and application thereof

Abstract

The invention provides a polymer additive as well as a preparation method and application thereof, and the preparation method comprises the following steps: carrying out free radical reaction on a hypophosphorous acid aqueous solution and an antioxidant with ethylene under the action of an initiator to obtain a diethyl hypophosphorous acid aqueous solution; the diethyl phosphinic acid aqueous solution, sulfuric acid and metal hydroxide are subjected to a reaction, then alkali liquor is added, and diethyl phosphinate slurry with the pH value being 3.8-4.2 is obtained; mixing and stirring the diethyl hypophosphite slurry and a flocculating agent to obtain diethyl hypophosphite flocculate, and then filtering, washing and drying to obtain the polymer additive. Through the design of the preparation method, the polymer additive with a low acid value can be obtained, and when the polymer additive is used as a flame retardant to prepare a polymer material, the precipitation of an auxiliary agent in a high-temperature processing process can be inhibited, and mold scale can be reduced, so that the prepared polymer composition has relatively low content of water boiling precipitates, and the service life of the polymer composition under damp and hot conditions is prolonged.

Description

Technical Field

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

[0002] As a universal halogen-free flame retardant, dialkyl phosphinates not only have good flame retardant properties, small addition amount, and little effect on the physical and electrical properties of the base resin, but also dialkyl phosphinate flame retardant materials have the characteristics of small smoke emission during combustion and high CTI (comparative tracking index), and are highly valued by the industry. At the same time, materials such as polyamide flame-retarded with dialkyl phosphinates have excellent mechanical and electrical properties, and are increasingly favored by manufacturers in the electrical and electrical industry, and have very broad market prospects.

[0003] Braun U et al. found that when dialkyl phosphinates flame retard PBT and polyamide, dialkyl phosphinates will decompose during high temperature.

[0004] When dialkyl phosphinates are used to flame retard polyamide, polyamide contains more polar amide groups, which makes it easier to absorb water and has a higher water absorption rate. For example, the water absorption rate of PA66 resin can reach 2.7% at 23°C and 50% humidity. During the extrusion process or high-temperature injection molding process, dialkyl phosphinates themselves have a certain acidity, and the heating process will also decompose dialkyl phosphinate acidic substances, which can easily promote the decomposition of the system and cause a large amount of gas in the processing process. In the repeated injection molding process, severe mold scale often appears on the mold, affecting the appearance of the product. Due to the presence of mold scale, the mold needs to be cleaned frequently, resulting in low efficiency, making it difficult to promote the use of the product.

[0005] 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 adds calcium oxide to the system, which neutralizes some acidic substances in the system, reduces the acidity of the system, and reduces the decomposition of the matrix resin, thereby effectively reducing the corrosion to the mold during high-temperature injection molding; although this method is helpful in reducing 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.

[0006] CN112409786A adds a certain amount of ethylene copolymer to the system to prepare a halogen-free flame-retardant thermoplastic polyamide with lower mold fouling. CN114874616A adds metal oxides and polyhydroxy systems to the system to prepare a halogen-free flame-retardant thermoplastic polyamide with better yellowing resistance and more continuous mold opening and closing times (lower mold fouling).

[0007] Although the above technical solutions have certain improvements on the mold fouling of dialkyl phosphite flame-retardant polyamide, they all improve the acidity of the system and reduce the mold fouling by adding external additives. While increasing the cost, it is difficult to avoid the influence of the addition of new substances on other properties of the flame-retardant polyamide. For example, the addition of inorganic metal oxides will cause a decrease in the mechanical properties of the material. Moreover, due to the nature defects of dialkyl phosphite itself not being fundamentally improved, the additives in the products containing it are likely to precipitate during high-temperature processing. On the one hand, it will block the pipelines of the processing equipment, and on the other hand, it will cause apparent defects in the products.

[0008] Therefore, how to provide a new polymer additive with low acidity and use it for the flame-retardant modification of polymer materials, which can reduce the precipitation of additives during high-temperature processing, and the modified polymer materials have low mold fouling and less additive precipitation, has become an urgent problem to be solved in the current field. Summary of the Invention

[0009] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a polymer additive, its preparation method and application. Through the design and co-action of materials and processes in the preparation method, a polymer additive with a low acid value can be obtained. When the polymer additive is used as a flame retardant to prepare polymer materials, it can inhibit or avoid the precipitation of additives during high-temperature processing, effectively reduce the mold fouling, make the prepared polymer composition have a low water-boiling precipitate content, and improve its service life under humid and hot conditions.

[0010] To achieve this purpose, the present invention adopts the following technical solutions:

[0011] In the first aspect, the present invention provides a preparation method of a polymer additive, and the preparation method includes the following steps:

[0012] (1) An aqueous solution of hypophosphorous acid and an antioxidant react with ethylene under the action of an initiator to obtain an aqueous solution of diethyl phosphinic acid;

[0013] (2) React the aqueous solution of diethyl phosphinic acid, sulfuric acid and metal hydroxide, and then add an alkali solution to obtain a slurry of diethyl phosphinate with a pH value of 3.8 - 4.2;

[0014] (3) Mix the slurry of diethyl phosphinate and a flocculant, stir to obtain a floc of diethyl phosphinate; filter, wash and dry the floc of diethyl phosphinate to obtain the polymer additive.

[0015] The research of the present invention finds that the reaction process of hypophosphorous acid and ethylene generally proceeds in the presence of a free radical initiator. Due to the existence of the P-H bond, hypophosphorous acid has strong reducing properties. Therefore, during the process of step (1), generally both free radical reactions and oxidation reactions exist. In the present invention, an antioxidant is introduced in step (1), which can donate electrons to the oxidant, thereby reducing it to a more stable substance to achieve the effect of the oxidation performance of the initiator. On the other hand, the free radical reaction between hypophosphorous acid and ethylene is a strong exothermic reaction, which is prone to uncontrollable phenomena during the production process and produces many side reactions. Another mechanism of the antioxidant is to capture free radicals in the form of reacting with free radicals and neutralize their activity, which can effectively slow down the exothermic effect and reduce the occurrence of side reactions, making the production process controllable. Adding an antioxidant during the process of step (1) of the present invention can effectively reduce the water-soluble acid value and organic acid value of the final product.

[0016] The research of the present invention finds that the pH of the reaction system has a great influence on the crystallization behavior during the precipitation process of the additive, thereby affecting the acid value of the polymer additive. The present invention designs to adjust the pH value of the product of step (2) reaction, and control the pH value of the obtained diethylphosphite slurry to be 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, 4.18, etc.; thereby enabling the prepared polymer additive to have a low acid value while ensuring a high yield of the product. If the pH value of the slurry is too low, it is easy to cause the acidity of the polymer additive to be too high and the yield to decrease; if the pH value of the slurry is too high, it will also cause the acid value of the polymer additive to increase, and further increase in pH will lead to a further decrease in the yield.

[0017] The research of the present invention finds that the introduction of a flocculant can fix the surface of the polymer additive particles on the molecular chain of the flocculant to form a bridge of the polymer, thereby causing the particles to form aggregates and settle. The flocculant adsorbs and binds to the polymer additive in the slurry obtained in step (2), which can effectively improve the filtration and washing effect of the polymer additive, and at the same time can effectively reduce the acidity of the polymer additive after filtration and washing.

[0018] In summary, the present invention designs a preparation method for a polymer additive. By using an antioxidant and a flocculant during the preparation process of the polymer additive and controlling the pH value of the diethylphosphite slurry to be 3.8 - 4.2, a polymer additive with a low acid value is prepared. When using this polymer additive as a flame retardant to prepare a polymer composition, it can inhibit or avoid the precipitation of additives during high-temperature processing, significantly reduce mold fouling, make the polymer composition have a low water-boiling precipitate content, and greatly improve the service life of the polymer composition under humid and hot conditions.

[0019] The following are the preferred technical solutions of the present invention, but do not 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.

[0020] Preferably, the antioxidant includes any one or a combination of at least two of hindered amine antioxidants, hindered phenol antioxidants, phosphite antioxidants, and thioester antioxidants, and more preferably any one or a combination of at least two of hindered phenol antioxidants, phosphite antioxidants, and thioester antioxidants.

[0021] Further preferably, the antioxidant includes any one or a combination of at least two of pentaerythritol tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (antioxidant 1010), n-octadecyl 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), distearyl β,β'-thiodipropionate (antioxidant DSTP), antioxidant 215, and antioxidant 225.

[0022] The antioxidant in the present invention can be a single component, such as any one of the above-listed antioxidants, or a composite antioxidant composed of multiple components, such as a combination of hindered phenol antioxidants and phosphite antioxidants. A typical combination is a compound of antioxidant 1010 and antioxidant 168 in different ratios, such as antioxidant 215, antioxidant 225, etc.

[0023] Preferably, the initiator includes any one or a combination of at least two of organic peroxides, persulfates, azo initiators, and photoinitiators.

[0024] 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.

[0025] Preferably, the persulfate includes any one of sodium persulfate, potassium persulfate, and ammonium persulfate, or a combination of at least two of them.

[0026] Preferably, the azo initiator includes any one of azobisisobutyronitrile, azobisisoheptanenitrile, azobisisobutyramidine hydrochloride, azobisisobutylimidazoline hydrochloride, and azoisobutylcyanoformamide, or a combination of at least two thereof.

[0027] 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.

[0028] It should be noted that the initiator in step (1) 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 (1) can be added in advance, and the rest can be added continuously during the reaction process.

[0029] Preferably, the mass percentage of hypophosphorous acid in the hypophosphorous acid aqueous solution 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.

[0030] Preferably, the mass ratio of the hypophosphorous acid to the antioxidant 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, etc., and more preferably 100:(0.05 - 1).

[0031] Preferably, the mass ratio of the hypophosphorous acid 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.

[0032] Preferably, the molar ratio of the ethylene to the 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, etc.

[0033] Preferably, the temperature of the free radical reaction 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 the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not list all the specific point values included in the range exhaustively. More preferably, it is 70 - 100 °C, and further preferably 75 - 95 °C.

[0034] The free radical reaction in step (1) is carried out in the presence of an initiator. When the pressure of the reaction system basically no longer changes, it can be considered that the reaction is complete and the reaction is stopped.

[0035] Preferably, the free radical reaction is carried out in a protective atmosphere.

[0036] Preferably, the protective atmosphere includes a nitrogen atmosphere and / or an argon atmosphere.

[0037] Preferably, the metal hydroxide includes any one or a combination of at least two of aluminum hydroxide, calcium hydroxide, copper hydroxide, zinc hydroxide, iron hydroxide, and titanium hydroxide, and more preferably aluminum hydroxide.

[0038] Preferably, the iron hydroxide includes ferrous hydroxide and / or ferric hydroxide.

[0039] By using the above metal hydroxides, the cations in the obtained diethyl phosphite include any one of Al, Ca, Cu, Zn, Fe or Ti, and more preferably Al.

[0040] Preferably, based on the molar amount of the diethyl phosphinic acid being 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 the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range.

[0041] Preferably, based on the molar amount of the diethyl phosphinic acid being 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 the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 8 - 30 mol%, and more preferably 10 - 15 mol%.

[0042] Preferably, the temperature of the reaction in step (2) 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 the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 80 - 120 °C, and more preferably 90 - 100 °C.

[0043] Preferably, the reaction time in step (2) is 2 - 12 h, for example, it can be 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 the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range.

[0044] Preferably, the alkali solution includes sodium hydroxide solution and / or potassium hydroxide solution.

[0045] The present invention has no special limitation on the mass concentration of the sodium hydroxide solution and the potassium hydroxide solution. It is only necessary to add the sodium hydroxide solution and / or the potassium hydroxide solution to maintain the pH of the diethylphosphite slurry obtained in step (2) at 3.8 - 4.2.

[0046] Preferably, the flocculant includes a polyacrylamide flocculant, more preferably an anionic polyacrylamide and / or a non-ionic polyacrylamide, and even more preferably an anionic polyacrylamide.

[0047] As a preferred technical solution of the present invention, using a polyacrylamide-based flocculant can fix the surface of the polymer additive particles on the molecular chain of the flocculant to form a bridge of the polymer. Especially when an anionic polyacrylamide is added as the flocculant, adsorption bridging and enhancement effects can be generated, so that the particles form aggregates and settle, improving the filtration and washing effect of the polymer additive and reducing the acid value of the polymer additive after filtration and washing.

[0048] Preferably, based on the mass of the theoretically obtained diethylphosphite being 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 the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range.

[0049] Among them, the "mass of the theoretically obtained diethylphosphite" is calculated from the input amounts of diethylphosphinic acid and metal hydroxide in step (2).

[0050] Preferably, the flocculant and water can be first mixed at 20 - 30°C for 10 - 20 min to obtain a flocculant solution, and then the flocculant solution is mixed with the diethylphosphite slurry and stirred. Among them, the mass ratio of the flocculant to water is 1:10 - 1000, for example, it can be 1:50, 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900 or 1:950, etc.

[0051] Preferably, the temperature of the mixing in step (3) 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 the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range.

[0052] Preferably, the number of times of washing in step (3) is ≥ 4 times, for example, it can be 5 times, 6 times, 7 times, 8 times, 9 times, 10 times or 12 times, etc., and more preferably 5 - 10 times.

[0053] Preferably, the washing reagent used for washing is water.

[0054] As a preferred technical solution of the present invention, the diethyl hypophosphite flocculant is filtered and washed multiple times. The number of times of washing is ≥ 4 times, preferably 5 - 10 times, which can better remove impurities and acidic substances in the product and obtain the polymer additive with a low acid value.

[0055] Preferably, the mass ratio of water to solids in each washing is independently (1 - 10):1, for example, it can be 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 product obtained by filtration.

[0056] Preferably, the temperature of drying in step (3) 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 the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range, and more preferably 110 - 150 °C.

[0057] As a preferred technical solution of the present invention, the preparation method of the polymer additive specifically includes the following steps:

[0058] (1) In an atmosphere of protective gas, an aqueous solution of hypophosphorous acid and an antioxidant react with ethylene under the action of an initiator to obtain an aqueous solution of diethyl hypophosphonate;

[0059] Among them, the mass concentration of the aqueous solution of hypophosphorous acid 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;

[0060] (2) React the aqueous solution of diethyl hypophosphonate, sulfuric acid and metal hydroxide at 70 - 150 °C for 2 - 12 h, and then add an alkali solution to make the pH of the system 3.8 - 4.2 to obtain a diethyl hypophosphite slurry;

[0061] Among them, based on the molar amount of diethyl hypophosphonate being 100%, the molar amount of the metal hydroxide is 30 - 50 mol%, and the molar amount of sulfuric acid is 5 - 50 mol%;

[0062] (3) Mix the diethyl phosphite slurry and the flocculant solution at 40 - 60 °C, and stir to obtain diethyl phosphite flocs; filter the diethyl phosphite flocs, wash them ≥4 times, and dry to obtain the polymer additive;

[0063] Among them, based on the mass of the theoretically obtained diethyl phosphite being 100%, the mass of the flocculant is 0.01 - 0.5%.

[0064] In a second aspect, the present invention provides a polymer additive, which is prepared by the preparation method as described in the first aspect. The water-soluble acid value of the polymer additive is ≤0.3 mg KOH / g; the polymer additive includes the following components by mass parts:

[0065]

[0066] The alkali-insoluble matter is selected from any one or a combination of at least two of hydroxides, oxides, phosphates, phosphites, and other alkyl phosphites.

[0067] The polymer additive provided by the present invention has a low acidity, and the water-soluble acid value is ≤0.3 mg KOH / g. When it is used as a flame retardant in a polymer composition, it can inhibit the decomposition of dialkyl phosphinic acid during the high-temperature process, inhibit or avoid the precipitation of additives during the high-temperature processing process, thereby avoiding the blockage of the device pipeline by the precipitates, and making the polymer composition have a lower water-boiling precipitate content, greatly improving its use stability under humid and hot conditions, extending its service life, and having a small amount of mold scale generated during the injection molding process.

[0068] The mass parts of diethyl phosphite in the polymer additive are 95 - 98.98 parts, for example, it can be 95.5 parts, 95.8 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 or 98.9 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0069] Preferably, the mass percentage content of diethyl phosphite in the polymer additive is ≥94%, for example, it can be 94.5%, 95%, 95.5%, 95.8%, 96%, 96.2%, 96.5%, 96.8%, 96.9%, 97%, 97.2%, 97.5%, 97.8%, 98%, 98.2%, 98.5%, 98.8% or 98.98%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0070] The mass fraction of ethyl butyl phosphinate in the polymer additive is 1-3 parts, for example, it can be 1.1 parts, 1.2 parts, 1.5 parts, 1.6 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 the specific values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific values included in the above range.

[0071] The mass fraction of ethyl phosphonate in the polymer additive is 0.01-0.7 parts, for example, it can be 0.02 parts, 0.05 parts, 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts or 0.65 parts, as well as the specific values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific values included in the above range.

[0072] The mass fraction of monoethyl phosphinate in the polymer additive is 0.01-0.3 parts, for example, it can be 0.02 parts, 0.04 parts, 0.05 parts, 0.06 parts, 0.08 parts, 0.1 parts, 0.12 parts, 0.14 parts, 0.15 parts, 0.16 parts, 0.18 parts, 0.2 parts, 0.22 parts, 0.25 parts or 0.28 parts, as well as the specific values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific values included in the above range.

[0073] The mass fraction of alkali-insoluble substances in the polymer additive is 0-3 parts, for example, it can be 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 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts or 2.8 parts, as well as the specific values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific values included in the above range.

[0074] Exemplarily, the mass fractions of diethyl phosphinate, diethyl phosphonate, ethyl phosphonate, and monoethyl phosphinate in the polymer additive can be analyzed and tested by liquid chromatography. For example, the sample to be tested is dissolved in a sulfuric acid aqueous solution (mass concentration 30%) five times the mass of the sample, and then diluted 10-30 times with the mobile phase for analysis and testing; the mobile phase is a mixed solution of water and methanol with a mass ratio of 9:1, adding 0.5% trifluoroacetic acid by volume, using a ShimNex CSC18 chromatographic column, and the flow rate is 0.6 mL / min; the mass content of each component is calculated by the area normalization method.

[0075] Exemplarily, the mass fraction of alkali-insoluble matter in the polymer additive is obtained by the following method: Mix the sample to be tested with an aqueous sodium hydroxide solution (mass concentration 3%) at a mass ratio of 1:100, stir at 35 °C for 30 min, filter with a filter paper with a precision ≤ 2 μm, and wash with water 3 times. After drying the filter paper, weigh it. The mass increase relative to the filter paper before filtration (dry filter paper) is the mass of the insoluble matter. 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.

[0076] Preferably, the polymer additive comprises the following components by mass fraction:

[0077]

[0078] Preferably, the cations in the diethyl phosphinate, ethyl butyl phosphinate, ethyl phosphonate, and monoethyl phosphinate are the same, and are selected from Al 3+ , Ca 2+ , Cu 2+ , Zn 2+ , Fe 2+ , Fe 3+ or Ti 4+ or a combination of any one or at least two of them.

[0079] In the present invention, the water-soluble acid value of the polymer additive is ≤ 0.3 mg KOH / g, and can be, for example, 0.1 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 mg KOH / 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 does not exhaustively list the specific point values included in the range. Preferably, it is 0.1 - 0.3 mg KOH / g.

[0080] Exemplarily, the water-soluble acid value of the polymer additive can be obtained by the following method: After uniformly wetting 1 g of the sample to be tested with ethanol (the mass of ethanol is m 乙醇 ), add water (the mass of water is m 水 ), boil in a sealed container at 90 °C for 1 h, then cool to 25 °C and keep constant temperature for 30 min, and make up the water to the total mass before boiling; filter to obtain the mass of the clear filtrate as m 1 . The acid value of the clear filtrate is measured by potentiometric titration. Among them, the concentration of the potassium hydroxide solution used in the titration is 0.05 mol / L. The water-soluble acid value of the polymer additive = measured acid value × (m 水 + m 乙醇 ) / m 1 .

[0081] Preferably, the organic acid value of the polymer additive is ≤ 0.05 mg KOH / g. For example, it can be 0.001 mg KOH / g, 0.01 mg KOH / g, 0.02 mg KOH / g, 0.022 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 point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 0.02 - 0.04 mg KOH / g.

[0082] Exemplarily, the organic acid value of the polymer additive can be tested by the following method: After uniformly wetting 1 g of the sample to be tested with dichloromethane (the mass of dichloromethane is m 二氯甲烷 ), boil it in a closed container at 90 °C for 1 h, then cool it to 25 °C and keep it at a constant temperature for 30 min, and make up dichloromethane to the total mass before boiling; filter to obtain the mass of the clear filtrate as m 1 , and measure the acid value of the clear filtrate by potentiometric titration. Among them, the concentration of the potassium hydroxide solution used for titration is 0.05 mol / L, and the organic acid value of the polymer additive = test acid value × m 二氯甲烷 / m 1 .

[0083] Preferably, the mass content of sulfate in the polymer additive is 100 - 700 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, 500 ppm, 550 ppm, 600 ppm, 650 ppm or 680 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 does not exhaustively list the specific point values included in the range. Further preferably, it is 270 - 420 ppm.

[0084] Exemplarily, the mass content of sulfate in the polymer additive is measured by external standard method using ion chromatography technology with reference to the method in Standard EN 14582 - "Determination of Halogen Content".

[0085] Preferably, the D of the polymer additive 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 does not exhaustively list the specific point values included in the above range. Further preferably, it is 20 - 60 μm, and more preferably 33 - 38 μm.

[0086] The D of the polymer additive 50 The particle size is the particle size corresponding to the cumulative volume distribution percentage of 50%, and can be measured by a laser particle size analyzer with reference to the standard GB / T 19077 - 2016 Laser diffraction method for particle size distribution.

[0087] Preferably, the water content of the polymer additive is 0.01 - 1 wt%, for example, it can be 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 does not exhaustively list the specific point values included in the above range. Further preferably, it is 0.05 - 0.3 wt%, and more preferably 0.1 - 0.25 wt%.

[0088] Exemplarily, the water content of the polymer additive can be tested by an infrared moisture analyzer, for example, using the MA 35 infrared moisture analyzer of Sartorius in Germany. After the sample is placed at 120 °C for 30 min, the water content is automatically tested.

[0089] Preferably, the phosphorus content of the polymer additive is 22 - 25 wt%, for example, it can 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%, 24.5 wt% 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 does not exhaustively list the specific point values included in the above range. Further preferably, it is 23 - 24 wt%.

[0090] Exemplarily, the phosphorus content of the polymer additive can be tested by the following method: Dissolve the sample to be tested with a sulfuric acid aqueous solution (mass concentration 30%), and test it with reference to the standard GB / T 11893 - 1989 "Determination of total phosphorus in water - Ammonium molybdate spectrophotometric method".

[0091] In a third aspect, the present invention provides an application of the polymer additive as described in the second aspect in a polymer material.

[0092] Preferably, the polymer additive is applied as a flame retardant to the polymer material.

[0093] Preferably, the polymer material includes any one or a combination of at least two of polyamide, polyester, polyurethane, styrenic polymer, polyolefin, polyphenylene ether, and polyacrylate, more preferably polyamide and / or polyester.

[0094] In a fourth aspect, the present invention provides a polymer composition, which includes a polymer matrix and the polymer additive as described in the second aspect.

[0095] Preferably, the polymer composition includes the following components by mass parts:

[0096] Polymer matrix 40 - 99 parts

[0097] The polymer additive 5 - 35 parts.

[0098] Preferably, the mass parts of the polymer matrix are 40 - 99 parts, for example, it 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 the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0099] Preferably, the mass parts of the polymer additive are 5 - 35 parts, for example, it 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 the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0100] Preferably, the polymer matrix includes polyamide and / or polyester.

[0101] Preferably, the polyamide includes any one or a combination of at least two of polyamide resin and polyamide elastomer.

[0102] As a polyamide, it includes any one or a combination of at least two of the condensation products of dicarboxylic acids and diamines, the condensation products of ω-amino acids, and the ring-opening polymerization products of cyclic lactams. Exemplarily, the dicarboxylic acids 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. Exemplarily, the diamines include, but are not limited to, any one or a combination of at least two of pentanediamine, hexanediamine, decanediamine, dodecanediamine, butanediamine, p-phenylenediamine, and m-phenylenediamine. Exemplarily, the cyclic lactams include, but are not limited to, any one or a combination of at least two of caprolactam, octanolactam, undecanolactam, and dodecanolactam. Exemplarily, the ω-amino acids include, but are not limited to, any one or a combination of at least two of the ω-amino acids formed by the ring-opening of the aforementioned cyclic lactams and aminobenzoic acid.

[0103] Preferably, the polyamide includes any one or a combination of at least two of polyamide 6 (polycaprolactam), polyamide 11 (polyundecanolactam), polyamide 12 (polydodecanolactam), polyamide 56 (polyadipoyl pentanediamine), polyamide 66 (polyadipoyl hexanediamine), polyamide 610 (polydecadipoyl hexanediamine), polyamide 612 (polydodecanedipoyl hexanediamine), polyamide 1010 (polydecadipoyl decanediamine), polyamide 1012 (polydodecanedipoyl decanediamine), polyamide 1212 (polydodecanedipoyl dodecanediamine), polyamide 6T (polyterephthaloyl hexanediamine), polyamide 10T (polyterephthaloyl decanediamine), and PPA (polyterephthaloyl p-phenylenediamine).

[0104] Preferably, the polyester includes the condensation product of a dicarboxylic acid and / or its derivative and a diol, wherein the dicarboxylic acid 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, and hydrogenated phthalic acid, and the derivatives include acid halides (acyl chlorides), esterified products, acid anhydrides, etc. formed from the dicarboxylic acid. Exemplarily, the diol includes, but is not limited to, any one or a combination of at least two of ethylene glycol, butanediol, and hexanediol.

[0105] Exemplarily, the polyester includes polyethylene terephthalate (PET) and / or polybutylene terephthalate (PBT).

[0106] It should be noted that the polymer composition of the present invention may further include any other fillers, other additives, etc. that are motivated to be added in the art.

[0107] Preferably, the polymer composition further includes a reinforcing material and / or a filler.

[0108] Preferably, the reinforcing material includes glass fiber and / or carbon fiber.

[0109] Preferably, the mass parts of the reinforcing material in the polymer composition ≤ 45 parts, and the mass parts of the reinforcing material can be 0, 0.5 part, 1 part, 2 parts, 5 parts, 8 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 42 parts or 44 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0110] Preferably, the filler includes any one or a combination of at least two of silica, talcum powder, titanium dioxide, barium sulfate, kaolin, calcium sulfate, boehmite, mica, magnesium carbonate, glass microspheres.

[0111] Preferably, the mass parts of the filler in the polymer composition ≤ 40 parts, and the mass parts of the filler can be 0, 0.5 part, 1 part, 2 parts, 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts or 38 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0112] Preferably, the polymer composition further includes 0 - 15 parts of other additives by mass parts, and the mass parts of the other additives can be 0, 0.1 part, 0.5 part, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts or 14 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0113] Preferably, the other additives include any one or a combination of at least two of antioxidant, ultraviolet absorber, lubricant, nucleating agent, stabilizer, antistatic agent, colorant.

[0114] Preferably, the polymer composition further includes any one or a combination of at least two of antioxidant, ultraviolet absorber, lubricant, nucleating agent, stabilizer, antistatic agent, colorant.

[0115] Preferably, the mass parts of antioxidant, ultraviolet absorber, lubricant, nucleating agent in the polymer composition are each independently 0.01 - 1.5 parts, for example, can be 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, 1 part, 1.2 part or 1.4 part, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0116] Preferably, the antioxidant in the polymer composition includes any one or a combination of at least two of hindered amine antioxidants, hindered phenol antioxidants, phosphite antioxidants, and thioester antioxidants.

[0117] Exemplarily, the antioxidant in the polymer composition includes any one or a combination of at least two of pentaerythritol tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (antioxidant 1010), n-octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate (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), distearyl thiodipropionate (antioxidant DSTP), antioxidant 215, and antioxidant 225.

[0118] Preferably, the lubricant includes any one or a combination of at least two of ester lubricants, alcohol lubricants, hydrocarbon lubricants, fatty acid lubricants, fatty acid amide lubricants, and metal soap lubricants.

[0119] Preferably, the polymer composition further includes 0-15 parts by mass of a synergistic flame retardant. The mass parts of the synergistic flame retardant can be 0, 0.1 part, 0.5 part, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, or 14 parts, as well as the specific point values between the above point values. For the sake of brevity and due to space limitations, the specific point values included in the scope of the present invention are not exhaustively listed herein.

[0120] Preferably, the synergistic flame retardant includes any one or a combination of at least two of melamine polyphosphate, melamine polyphosphate salt, zinc borate, zinc stannate, zinc sulfide, and boehmite.

[0121] In a preferred technical solution, the polymer composition includes the following components in parts by mass:

[0122]

[0123]

[0124] Preferably, the mass percentage of the polymer matrix in the polymer composition is 40%-99%, for example, it can be 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0125] Preferably, the mass percentage of the polymer additive in the polymer composition is 5%-35%, for example, it can be 6%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32% or 34%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 6%-20%.

[0126] Exemplarily, the preparation method of the polymer composition includes: melting and blending the components of the polymer composition and then extruding to obtain the polymer composition.

[0127] Preferably, first premix the polymer matrix, optionally the filler, and optionally other additives to obtain a premix; then melt and blend the premix, the polymer additive, and optionally the reinforcing material and extrude to obtain the polymer composition.

[0128] Preferably, the melting and blending is carried out in a screw extruder.

[0129] Preferably, the screw extruder is a twin-screw extruder.

[0130] 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 the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0131] Preferably, after extrusion, it further includes the steps of pelletizing and drying.

[0132] Compared with the prior art, the present invention has the following beneficial effects:

[0133] In the preparation method of the polymer additive provided by the present invention, through the design of materials such as antioxidants and flocculants, the design of processes and their parameters, and their combined action, a polymer additive with a low acid value is obtained. When using this polymer additive as a flame retardant to prepare a polymer composition, it can inhibit or avoid the precipitation of additives during high-temperature processing, prevent the precipitates from clogging the device pipelines, and at the same time significantly reduce the mold scale generated during injection molding, and make the polymer composition have a low content of water-boiled precipitates, greatly improving the stability and service life of the polymer composition under humid and hot conditions. Detailed Embodiments

[0134] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0135] As used herein, the terms "comprising", "including", "having", "containing" or any other variation thereof are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or device containing the recited elements is not necessarily limited to those elements, but may also include other elements not expressly listed or elements inherent to such composition, step, method, article or device.

[0136] In the following specific embodiments, the test methods for the parameters of the polymer additive are as follows:

[0137] (1) Content test of diethyl phosphinate, ethyl butyl phosphinate, ethyl phosphonate, and monoethyl phosphinate

[0138] It is analyzed and tested by a liquid chromatograph (LC20A, Shimadzu, Japan). Among them, diethyl phosphinate uses a commercially available standard sample, ethyl butyl phosphinate uses its pure product (prepared according to Example 4 of CN103172668A) as a standard sample, ethyl phosphonate uses its pure product (prepared according to Example 2 of CN104371142A) as a standard sample, and monoethyl phosphinate uses its pure product (prepared according to Example 1 of CN103172668A) as a standard sample; the sample to be tested is dissolved in a sulfuric acid aqueous solution (mass concentration 30%) 5 times the mass of the sample, and then diluted 20 times with the mobile phase for analysis and testing; the mobile phase uses a mixed solution of water and methanol with a mass ratio of 9:1, adding trifluoroacetic acid with a volume content of 0.5%, the chromatographic column uses ShimNex CS C18 5μm, 4.6×250mm, and the flow rate is 0.6 mL / min; the mass content of each component is calculated by the area normalization method.

[0139] (2) Content of alkali-insoluble substances

[0140] 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 a filter paper with a precision ≤ 2 μm, and wash it 3 times with 100 g of water. After drying the filter paper and weighing it, the mass increase relative to the filter paper before filtration (dry filter paper) is the mass of the insoluble matter. The ratio of the mass of the insoluble matter to the mass of the sample to be tested (5 g) is the mass content of the alkali-insoluble matter.

[0141] (3) Water-soluble acid value

[0142] Take 1 g of the sample to be tested, add 5.00 ± 0.01 g (m 乙醇 ) of ethanol and wet it evenly, then add 50 ± 0.01 g (m 水 ) of normal temperature water. Weigh the total weight m 0 of the bottle with stirring. After boiling it in a sealed state at 90 °C for 1 h, cool it to 25 °C and keep it at a constant temperature for 30 min, and make up the water to the total weight m 0 ; Filter it to obtain a clear filtrate with a mass of m 1 . Measure the acid value of the test by the potentiometric titration test method for the clear filtrate. Among them, the concentration of the potassium hydroxide solution used for titration is 0.05 mol / L. The water-soluble acid value of the polymer additive = test acid value × (m 水 + m 乙醇 ) / m 1 .

[0143] (4) Organic acid value

[0144] Take 1 g of the sample to be tested, add 50.0 ± 0.01 g (m 二氯甲烷 ) of dichloromethane and wet it evenly. Weigh the total weight m 0 of the bottle with stirring. After boiling it in a sealed state at 90 °C for 1 h, cool it to 25 °C and keep it at a constant temperature for 30 min, and make up dichloromethane to the total weight m 0 ; Filter it to obtain a clear filtrate with a mass of m 1 . Measure the acid value of the test by the potentiometric titration test method for the clear filtrate. Among them, 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 1 .

[0145] (5) Mass content of sulfate

[0146] Refer to the method in the standard EN 14582: 2007 - "Determination of halogen content", and use ion chromatography technology to measure by the external standard method.

[0147] (6) D 50 Particle size

[0148] Take 0.1 g of the sample to be tested, moisten it with 5 g of ethanol, then add 50 mL of water for dilution, and conduct the test using a Mastersizer 3000 laser particle size analyzer.

[0149] (7) Moisture content

[0150] Place the sample to be tested in an infrared moisture analyzer (Model MA 35, Sartorius, Germany), and automatically measure the water content after placing it at 105 °C for 30 min.

[0151] (8) Phosphorus content

[0152] Take 0.1 g of the sample to be tested, add 2 g of sulfuric acid aqueous solution (mass concentration 30%) for dissolution, and conduct the test with reference to Standard GB / T 11893-1989 "Determination of Total Phosphorus in Water - Ammonium Molybdate Spectrophotometry".

[0153] In the following specific embodiments of the present invention, all materials for which the preparation method is not provided are commercially available chemicals, and the specific information of some materials is as follows:

[0154] Brand, Manufacturer Antioxidant 1076 RIANOX 1076, commercially available Antioxidant 1010 RIANOX 1010, commercially available Antioxidant 608 Revonox 608, commercially available Flocculant: Anionic polyacrylamide Gongyi Xinqi Polymer Co., Ltd. Polyamide 66 (PA66) PA66 M2000, Guangdong Xinhui Meida Nylon Co., Ltd. Polyamide 6 (PA6) PA6 EPR24, Shenma Industry Co., Ltd. Melamine polyphosphate (MPP) BUDIT 3141, Budenheim, Germany Glass fiber ECS10-03-568H, China National Bluestar (Group) Co., Ltd. Lubricant TR044W, Struktol, Germany Antioxidant 1098 RIANOX 1098, commercially available Antioxidant 168 RIANOX 168, commercially available

[0155] The following will take multiple examples to elaborate on the polymer additive and its preparation method described in the present invention, but the polymer additive and its preparation method are not limited to these examples.

[0156] Examples 1-9, Comparative Examples 1-5

[0157] A polymer additive and its preparation method are as follows:

[0158] (1) Put 39.6 kg of hypophosphorous acid aqueous solution with a mass content of 50%, 500 g of sodium persulfate, and an antioxidant with a mass of m 1 into an autoclave, displace with nitrogen 3 times, keep the pressure of ethylene constant at 1.5 MPa through a pressure reducer, heat to a temperature of T 1 , keep warm for 5.5 h, continuously supplement 3500 g of sodium persulfate aqueous solution with a mass content of 10% during the heat preservation process, and then keep warm at temperature T 1 for 1.5 h, cool and vent to obtain an aqueous solution of diethylphosphinic acid;

[0159] (2) Mix the aqueous solution of diethylphosphinic acid obtained in step (1) (diethylphosphinic acid is 6 mol), sulfuric acid aqueous solution (mass content of sulfuric acid is 30%, molar amount is n 1 ) and 2 mol of aluminum hydroxide, heat to temperature T 2 , stir and react for 8 h, and adjust the pH value with sodium hydroxide solution (mass content is 10%) to obtain a diethylphosphinate slurry;

[0160] (3) At 50 °C, an aqueous solution of a flocculant prepared from anionic polyacrylamide with a mass of m 2 and 50 g of water was added to the diethyl phosphinate slurry obtained in step (2), stirred until in a flocculated state, filtered, the filter cake was washed 5 times with 3 times its mass of water, and dried at 110 °C to constant weight to obtain a polymer additive.

[0161] The specific process parameters of the preparation method and the relevant data of the obtained polymer additive are shown in Tables 1 and 2; "--" indicates that the material was not added.

[0162] Table 1

[0163]

[0164]

[0165] Table 2

[0166]

[0167] As can be seen from Table 1, the present invention designs a preparation method for a polymer additive. In particular, through the use of antioxidants, flocculants, and control of the pH value of the slurry, a polymer additive with a low acid value is prepared, and its water-soluble acid value ≤ 0.3 mg KOH / g. The polymer additive includes the following components by mass parts: 95 - 98.98 parts of diethyl phosphinate, 1 - 3 parts of ethyl butyl phosphinate, 0.01 - 0.7 parts of ethyl phosphonate, 0.01 - 0.3 parts of monoethyl phosphinate, and 0 - 3 parts of alkali-insoluble substances.

[0168] In Table 2, the pH values of the slurries in Comparative Examples 1 - 2 exceeded the defined range of the present invention, antioxidants were not used in Comparative Examples 3 - 4, and a flocculant was not added in Comparative Example 5, resulting in a significant increase in both the water-soluble acid value and the organic acid value of the polymer additive.

[0169] Next, the application of the polymer additive of the present invention will be described in detail by taking application examples as an example, but the application of the polymer additive is not limited to these application examples.

[0170] Application Examples 1 - 9, Comparative Application Examples 1 - 5

[0171] A polymer composition, specifically a polyamide composition, the types and dosages of each component are shown in Tables 3 and 4, and the dosage unit of each component is "mass part".

[0172] 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 amounts to obtain a premix; adding the premix to a twin-screw extruder, with the screw speed of the twin-screw extruder being 400 rpm and the temperatures of zones 1 - 12 being 90°C, 180°C, 260°C, 250°C, 230°C, 230°C, 220°C, 220°C, 220°C, 220°C, 260°C, 260°C respectively, and performing melt mixing and pelletizing by extrusion to obtain polyamide composition pellets.

[0173] The following performance tests were conducted on the polyamide composition:

[0174] (1) Water-boiling phosphorus content test: Take 50 g of the polyamide composition pellets, add them to 500 mL of hot water at 90°C, boil for 1 h, cool to room temperature, filter, and measure the phosphorus content of the filtrate by the ammonium molybdate spectrophotometric method of GB / T 11893 - 1989.

[0175] (2) Mold fouling test method: Using an injection molding machine, at injection molding temperatures of 290°C, 285°C, 280°C, and 260°C for the polyamide composition pellets, continuously inject 150 molds, take the mold fouling sample in the finally collected mold, and weigh it using an analytical balance.

[0176] (3) Exudation amount during extrusion: Add a cyclone separator with jacket cooling to the vacuum pipeline of a twin-screw extruder with a diameter of 75 mm and a length-diameter ratio of 48:1 to separate the exuded substances evacuated by vacuum during the extrusion process. After continuously producing 2000 kg of products, weigh the exuded substances in the cyclone separator, which is the exudation amount during extrusion; among them, blockage represents an excessive exudation amount, resulting in the vacuum system being blocked before 8 h of production is completed.

[0177] The test data for each item are shown in Tables 3 and 4.

[0178] Table 3

[0179]

[0180] Table 4

[0181]

[0182] According to the data in Table 3, it can be seen that the polymer additive provided by the present invention, when used as a flame retardant in the polyamide composition, can effectively inhibit the exudation of additives during the extrusion process, reduce the risk of blockage, and at the same time significantly reduce the mold fouling generated during injection molding, making the mold fouling ≤ 7.2 mg, and the water-boiling phosphorus content of the polyamide composition ≤ 490 ppm, reducing the content of water-boiling exudates and improving the stability and service life of the polyamide composition under humid and hot conditions.

[0183] According to the test data in Table 4, since the polymer additives in Comparative Examples 1-5 have a high acid value, when used as flame retardants in polyamide compositions, there are obvious problems of additive precipitation during the extrusion process, which easily leads to pipeline blockage problems, and there are more injection mold scales, and the phosphorus content in boiling water increases, indicating that their stability under humid and hot conditions is significantly insufficient.

[0184] The applicant declares that the present invention uses the above embodiments to illustrate the polymer additives of the present invention and their preparation methods and applications, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the products of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a polymer additive, characterized in that: The preparation method comprises the following steps: (1) the hypophosphorous acid aqueous solution and the antioxidant react with ethylene under the action of an initiator to obtain a diethylphosphinic acid aqueous solution; (2) reacting the diethylphosphinic acid aqueous solution, sulfuric acid and metal hydroxide, and then adding alkali solution to obtain a diethylphosphinic acid salt slurry with a pH value of 3.8-4.2; (3) mixing the diethyl phosphinate slurry and the flocculant, stirring to obtain diethyl phosphinate flocs; filtering, washing and drying the diethyl phosphinate flocs to obtain the polymer additive.

2. The preparation method according to claim 1, characterized in that: The antioxidant includes any one of hindered amine antioxidants, hindered phenol 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; Preferably, the antioxidant includes any one of tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), n-octadecylβ-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, 2,6-di-tert-butyl-p-cresol, and distearylβ,β-thiodipropionate, or a combination of at least two thereof; Preferably, the initiator includes any one of an organic peroxide, a persulfate, an azo initiator, and a photoinitiator, or a combination of at least two of them.

3. The preparation method according to claim 1, characterized in that: The mass percentage of hypophosphorous acid in the hypophosphorous acid aqueous solution is 20-70%, preferably 45-55%; Preferably, the mass ratio of the hypophosphorous acid to the antioxidant is 100:(0.02-1.2), and more preferably 100:(0.05-1); Preferably, the mass ratio of the hypophosphorous acid to the initiator is 100:(0.1-5).

4. The preparation method according to claim 1, characterized in that: The temperature of the free radical reaction is 60-105°C, preferably 70-100°C, and more preferably 75-95°C; Preferably, the free radical reaction is carried out in a protective atmosphere; Preferably, the protective atmosphere includes a nitrogen atmosphere and / or an argon atmosphere.

5. The preparation method according to claim 1, characterized in that: The metal hydroxide includes any one of aluminum hydroxide, calcium hydroxide, copper hydroxide, zinc hydroxide, iron hydroxide, and titanium hydroxide, or a combination of at least two thereof, preferably aluminum hydroxide; Preferably, based on the molar amount of the diethylphosphinic acid as 100%, the molar amount of the metal hydroxide is 30-50 mol%; Preferably, based on the molar amount of the diethylphosphinic acid as 100%, the molar amount of the sulfuric acid is 5-50 mol%, further preferably 8-30 mol%, and more preferably 10-15 mol%; Preferably, the reaction temperature in step (2) is 70-150°C, more preferably 80-120°C, and more preferably 90-100°C; Preferably, the reaction time in step (2) is 2-12 hours.

6. The preparation method according to claim 1, characterized in that: The flocculant includes a polyacrylamide flocculant, preferably anionic polyacrylamide and / or nonionic polyacrylamide, more preferably anionic polyacrylamide; Preferably, based on the theoretical mass of the diethylphosphinate being 100%, the mass of the flocculant is 0.01-0.5%; Preferably, the mixing temperature in step (3) is 40-60°C; Preferably, the number of washing steps in step (3) is ≥ 4 times.

7. A polymer additive, characterized in that The polymer additive is prepared by the preparation method according to any one of claims 1 to 6, and the water-soluble acid value of the polymer additive is ≤0.3 mg KOH / g; The polymer additive comprises the following components in parts by mass: The alkali-insoluble substance is selected from any one of hydroxides, oxides, phosphates, phosphites, and other alkyl phosphonates, or a combination of at least two thereof.

8. The polymer additive according to claim 7, characterized in that The water-soluble acid value of the polymer additive is 0.1-0.3 mg KOH / g; Preferably, the organic acid value of the polymer additive is ≤0.05 mg KOH / g, more preferably 0.02-0.04 mg KOH / g; Preferably, the mass content of sulfate in the polymer additive is 100-700 ppm, more preferably 270-420 ppm; Preferably, the polymer additive has a D 50 The particle size is 1-100 μm, more preferably 20-60 μm, and further preferably 33-38 μm; Preferably, the water content of the polymer additive is 0.01-1wt%, more preferably 0.05-0.3wt%, and even more preferably 0.1-0.25wt%; Preferably, the phosphorus content of the polymer additive is 22-25 wt %, more preferably 23-24 wt %.

9. Use of the polymer additive according to claim 7 or 8 in a polymer material; Preferably, the polymer additive is applied to the polymer material as a flame retardant.

10. A polymer composition, characterized in that The polymer composition comprises a polymer matrix and the polymer additive according to claim 7 or 8; Preferably, the polymer composition comprises the following components in parts by mass: Polymer matrix 40-99 parts 5-35 parts of the polymer additive; Preferably, the polymer matrix comprises polyamide and / or polyester.

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