Polymer additive as well as preparation method and application thereof

Abstract

The invention provides a polymer additive and a preparation method and application thereof, the polymer additive comprises aluminum diethylphosphinate, and the particle size of the polymer additive meets the following relational expression: 1.1 < = 100 * (D75-D25) / (D50) < 2 > < = 1.8; 0.5 < = (D97 * D50) / (D10 * 100) < = 2.0; the D50 particle size of the polymer additive is 25-50 [mu] m. According to the invention, the particle size distribution of the polymer additive meets the relational expression of the formula I and the formula II, and the polymer additive has specific particle size distribution parameters, so that the uniform dispersion of the polymer additive in a polymer system is realized, a polymer composition containing the polymer additive does not have apparent defects such as heterochromatic spots and white spots, and the quality of a flame-retardant polymer product is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer additives, and in particular relates to a polymer additive and a preparation method and application thereof. Background Art

[0002] Flame retardants can prevent or delay the combustion of polymer materials and are important additives for polymer materials. With the increasing awareness of environmental protection, flame retardants must not only have flame retardant properties but also meet the development trend of environmental protection and ecological safety. In this context, some traditional flame retardants containing halogens have gradually withdrawn from the market. Organophosphorus flame retardants, as a halogen-free and environmentally friendly flame retardant, have high flame retardant efficiency, low toxicity, low corrosiveness and good compatibility, and have become a research hotspot in recent years.

[0003] Alkyl phosphinates are a new type of organophosphorus flame retardant with excellent flame retardancy, low smoke density, high CTI (Current Tracking Index), and environmental friendliness. They have minimal impact on the physical and electrical properties of the base polymer and are widely used in polyamide, polyester, and polyurethane materials, enabling flame-retardant polymer products containing them to exhibit superior mechanical and electrical properties. However, with the widespread use of alkyl phosphinates, it has been discovered that these flame retardants have poor dispersion properties in polymer systems, are difficult to shear disperse, and are prone to agglomeration. This can lead to flame retardant precipitation, decreased mechanical properties, and surface defects in finished products.

[0004] To improve the dispersibility of alkyl phosphinates, the main method in the industry is to modify them by adding other additives. For example, CN118240373A discloses a flame-retardant PA10T material. The raw materials include: 100 parts by weight of PA10T, 5-50 parts by weight of a modified flame retardant, 1-20 parts by weight of an additive, and 0-100 parts by weight of a filler. The modified flame retardant is diethylaluminum hypophosphite and magnesium hydroxide modified with a long-chain amide having 8-12 carbon atoms. Because the long-chain amide, which is highly compatible with PA10T, is used as a surface modifier, the modified flame retardant is less likely to agglomerate and is easier to disperse in the matrix, reducing raw material agglomeration. CN115353732A discloses a flame retardant composition for PA10T, comprising 5-50 parts by weight of melamine polyphosphate, 5-70 parts by weight of diethyl aluminum hypophosphite, and 5-20 parts by weight of chitosan oligosaccharide. The melamine polyphosphate and diethyl aluminum hypophosphite synergistically provide flame retardancy, and the addition of chitosan oligosaccharide promotes the dispersion of the flame retardant in PA10T, allowing it to better exert its synergistic flame retardant effect. CN111961340A discloses a halogen-free flame-retardant bio-based nylon 56 composite material, comprising 50-75 parts of bio-based PA56, 0.1-1 part of an antioxidant, 0.1-1 part of a lubricant, 15-20 parts of a halogen-free flame retardant, 10-30 parts of a reinforcing material, and 0.3-0.8 parts of a flow dispersant. The halogen-free flame retardant is diethyl aluminum hypophosphite, and the flow dispersant is CF-201 micropowder, a special flow modifier for nylon, which can improve the dispersion and precipitation problems of diethyl aluminum hypophosphite.

[0005] Although the addition of modifying and dispersing agents can improve the dispersibility of alkyl phosphinates to a certain extent, the type of agent needs to be adjusted accordingly based on the polymer matrix and other components. In other words, different types of agents need to be screened for different product formulations, which is quite difficult in practical applications. Moreover, the addition of agents usually causes varying degrees of degradation in the mechanical properties and stability of polymer products. The agent modification scheme does not fundamentally solve the problem of poor dispersion of alkyl phosphinates in the polymer matrix.

[0006] Therefore, how to fundamentally solve the dispersibility problem of alkyl phosphinates and how to improve the apparent defects of polymer products using them are the research focuses in this field. Summary of the Invention

[0007] In response to the deficiencies of the prior art, the present invention aims to provide a polymer additive and its preparation method and application. The polymer additive has specific particle size distribution parameters, which enables its uniform dispersion in the polymer system, so that the polymer composition containing it has no apparent defects such as discoloration spots, thereby greatly improving the quality of flame-retardant polymer products.

[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, comprising aluminum diethylphosphinate, wherein the particle size of the polymer additive satisfies the relationship shown in Formula I and Formula II:

[0010] 1.1≤100×(D 75 -D 25 ) / (D 50 ) 2 ≤1.8 Formula I;

[0011] 0.5≤(D 97 ×D 50 ) / (D 10 ×100)≤2.0 Formula II;

[0012] Among them, D 10 、D 25 、D 50 、D 75 、D 97 Respectively represent the particle sizes corresponding to the cumulative volume distribution percentages of the polymer additive being 10%, 25%, 50%, 75%, and 97%;

[0013] The polymer additive D 50 The particle size is 25-50μm.

[0014] The present invention has found that when the particle size of the flame retardant is too fine, agglomeration is likely to occur. When the particle size is too large, the large particles are not easily sheared and dispersed, resulting in uneven dispersion in polymer applications, causing white discoloration spots (i.e., undispersed flame retardant) or easy precipitation in polymer products. Based on this, the particle size distribution of the polymer additive provided by the present invention satisfies the relationship between Formula I and Formula II, and has specific particle size distribution parameters, which can achieve uniform dispersion in the polymer system, so that the polymer composition containing it has no apparent defects such as discoloration spots (no white spots), greatly improving the quality of flame-retardant polymer products.

[0015] Specifically, Formula I designed in the present invention can reflect the overall width of the particles of the polymer additive, and Formula II can balance the extreme particles, taking into account the influence of the intermediate and tail particles, and solving the problem that the traditional particle size distribution parameters ignore the tail distribution. The present invention, through the mutual combination of Formula I and Formula II, defines the distribution characteristics of the particle system of the polymer additive from multiple dimensions, reduces extreme particles, thereby controlling the uniformity, stability and functionality of the particles, increasing the bulk density of the particles, making them easy to disperse and having better fluidity, helping to reduce processing safety hazards, and avoiding surface defects of the polymer composition caused by uneven additives and the resulting adverse effects on mechanical properties.

[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] It should be noted that the polymer additive of the present invention includes aluminum diethylphosphinate, and optionally also includes a trace amount of aluminum ethylbutylphosphinate, an optional trace amount of ethyl aluminum phosphite, and the like.

[0018] In the present invention, the polymer additive D 10 、D 25 、D 50 、D 75 、D 97 The particle size distribution can be determined by laser diffraction method according to GB / T 19077-2016, using a laser particle size analyzer. For example, the determination method is a wet test using water as the dispersion medium.

[0019] In formula I, 1.1≤100×(D 75 -D 25 ) / (D 50 ) 2 ≤1.8,100×(D 75 -D 25 ) / (D 50 ) 2 It can be 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7 or 1.75, as well as specific values between the above values. Due to space limitations and for the sake of simplicity, the present invention will no longer exhaustively list the specific values included in the range. Preferably, 1.2≤100×(D 75 -D 25 ) / (D 50 ) 2 ≤1.7.

[0020] In formula II, 0.5≤(D 97 ×D 50 ) / (D 10 ×100)≤2.0, (D 97 ×D 50 ) / (D 10 ×100) can be 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 1.95 or 1.98, 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. Preferably, 0.8≤(D 97 ×D 50 ) / (D10 ×100)≤1.55.

[0021] The polymer additive D 50 The particle size is 25-50 μm, for example, it can be 26 μm, 28 μm, 30 μm, 32 μm, 35 μm, 38 μm, 40 μm, 42 μm, 45 μm or 48 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.

[0022] Preferably, the polymer additive has a D 25 The particle size is 20-40 μm, for example, it can be 22 μm, 24 μm, 25 μm, 28 μm, 30 μm, 32 μm, 35 μm or 38 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 21-30 μm is further preferred.

[0023] And / or, preferably, the polymer additive has a D 75 The particle size is 30-70 μm, for example, it can be 32 μm, 35 μm, 38 μm, 40 μm, 42 μm, 45 μm, 48 μm, 50 μm, 52 μm, 55 μm, 58 μm, 60 μm, 62 μm, 65 μm or 68 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 35-60 μm is further preferred.

[0024] Preferably, the polymer additive has a D 10 The particle size is 10-25 μm, for example, it can be 12 μm, 15 μm, 18 μm, 20 μm, 22 μm or 24 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 15-20 μm is further preferred.

[0025] And / or, preferably, the polymer additive has a D 97 The particle size is 40-90 μm, for example, it can be 42 μm, 45 μm, 48 μm, 50 μm, 52 μm, 55 μm, 58 μm, 60 μm, 62 μm, 65 μm, 68 μm, 70 μm, 72 μm, 75 μm, 78 μm, 80 μm, 82 μm, 85 μm or 88 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 45-80 μm is further preferred.

[0026] Preferably, the molar percentage of aluminum diethylphosphinate in the polymer additive is ≥90%, for example, it can be 91%, 92%, 94%, 95%, 96%, 98%, 99%, 99.5%, 99.7%, 99.8%, 99.9%, 99.99% or 100%, as well as specific values between the above points. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively enumerate the specific points included in the range, and 93-99.7% is further preferred.

[0027] Preferably, the polymer additive further comprises aluminum ethylbutylphosphinate and / or aluminum ethylphosphinate.

[0028] Preferably, the molar percentage of aluminum ethylbutylphosphinate in the polymer additive is ≤4%, for example, it can be 0, 0.01%, 0.05%, 0.1%, 0.2%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3% or 3.5%, 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, and is further preferably ≤3%.

[0029] Preferably, the molar percentage of aluminum ethylphosphite in the polymer additive is ≤1%, for example, it can be 0, 0.01%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.8% or 0.9%, 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, and is further preferably ≤0.7%.

[0030] In the present invention, the structure of aluminum diethylphosphinate is The structure of aluminum ethylbutylphosphinate is The structure of aluminum ethylphosphite is

[0031]

[0032] It should be noted that the polymer additive may also optionally include other homologues, such as any one or a combination of at least two of dibutyl aluminum phosphinate, ethylhexyl aluminum phosphinate, dihexyl aluminum phosphinate, etc.

[0033] Preferably, the sum of the molar contents of aluminum diethylphosphinate, aluminum ethylbutylphosphinate (if any) and aluminum ethylphosphinate (if any) in the polymer additive is ≥99.5%, for example, it can be 99.55%, 99.6%, 99.65%, 99.7%, 99.75%, 99.8%, 99.85%, 99.9%, 99.95%, 99.99% or 100%.

[0034] In a second aspect, the present invention provides a method for preparing the polymer additive according to the first aspect, the preparation method comprising:

[0035] providing a dispersion solution comprising a combination of water and a soluble flocculant;

[0036] The polymer additive is obtained by carrying out a double decomposition reaction between a soluble diethylphosphinate and a soluble aluminum salt in the presence of the dispersed solution using a continuous salt-forming process.

[0037] In the preparation method of the polymer additive provided by the present invention, a double decomposition reaction of a soluble diethylphosphinate and a soluble aluminum salt is carried out in the presence of a soluble flocculant. The addition of the soluble flocculant can control the particle distribution so that the formed polymer additive is neither too large nor too small, and makes the crystallization process of the product more compact and the particle distribution more uniform, thereby achieving a polymer additive having the specific particle size parameters of Formula I and Formula II.

[0038] Preferably, the soluble flocculant comprises polyaluminium sulfate and / or polyaluminium chloride.

[0039] Preferably, the mass ratio of water to soluble flocculant in the dispersed solution is 1:(0.002-0.01), for example, it can be 1:0.003, 1:0.004, 1:0.005, 1:0.006, 1:0.007, 1:0.008, 1:0.009, etc.

[0040] Preferably, the soluble diethylphosphinate includes any one or a combination of at least two of sodium diethylphosphinate, potassium diethylphosphinate, and ammonium diethylphosphinate, more preferably sodium diethylphosphinate.

[0041] Preferably, the soluble aluminum salt comprises aluminum sulfate and / or aluminum sulfate hydrate.

[0042] Preferably, the molar ratio of the soluble aluminum salt to the soluble diethylphosphinate is 1:(5.8-6.2), for example, it can be 1:5.82, 1:5.85, 1:5.88, 1:59, 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.

[0043] Preferably, the preparation method adopts a continuous salt formation method, and the preparation method comprises the following steps:

[0044] The dispersed solution is placed in a reaction device, and then a soluble diethylphosphinate aqueous solution and a soluble aluminum salt aqueous solution are respectively and simultaneously and continuously injected into the reaction device to carry out a double decomposition reaction to obtain the polymer additive.

[0045] Preferably, the mass ratio of the soluble diethylphosphinate aqueous solution to the soluble flocculant in the dispersed solution is 1:(0.0001-0.002), for example, it can be 1:0.0002, 1:0.0004, 1:0.0005, 1:0.0008, 1:0.0001, 1:0.0011, 1:0.0012, 1:0.0013, 1:0.0014, 1:0.0015, 1:0.0016, 1:0.0017, 1:0.0018 or 1:0.0019, etc.

[0046] Preferably, the concentration of soluble diethyl phosphinate in the aqueous solution of soluble diethyl phosphinate is 1-2 mol / kg, for example, 1.1 mol / kg, 1.2 mol / kg, 1.3 mol / kg, 1.4 mol / kg, 1.5 mol / kg, 1.6 mol / kg, 1.7 mol / kg, 1.8 mol / kg or 1.9 mol / kg, 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.

[0047] Preferably, the concentration of the soluble aluminum salt in the aqueous solution of soluble aluminum salt is 0.3-0.6 mol / kg, for example, it can be 0.32 mol / kg, 0.35 mol / kg, 0.38 mol / kg, 0.4 mol / kg, 0.42 mol / kg, 0.45 mol / kg, 0.48 mol / kg, 0.5 mol / kg, 0.52 mol / kg, 0.55 mol / kg or 0.58 mol / kg, 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.

[0048] Preferably, the soluble aluminum salt comprises aluminum sulfate and / or aluminum sulfate hydrate, and the feed molar ratio of the soluble aluminum salt to the soluble diethyl phosphinate is 1:(5.8-6.2), for example, it can be 1:5.82, 1:5.85, 1:5.88, 1:59, 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., and more preferably 1:(5.9-6.1).

[0049] Preferably, the temperature of the metathesis reaction is 20-90°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, 75°C, 80°C or 85°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 enumerates the specific point values included in the range, and 40-85°C is further preferred.

[0050] Preferably, the metathesis reaction method comprises: simultaneously and continuously feeding a soluble diethylphosphinate aqueous solution and a soluble aluminum salt aqueous solution in one stage and performing a first-stage reaction, and then feeding in two stages and performing a second-stage reaction to obtain the polymer additive.

[0051] As a preferred technical solution of the present invention, a soluble diethylphosphinate aqueous solution and a soluble aluminum salt aqueous solution are first fed simultaneously and continuously in a first stage and then kept warm for a period of time to react, thereby forming pre-preformed particles. During this stage, the presence of a soluble flocculant can control the distribution of the pre-preformed particles. Then, the soluble diethylphosphinate aqueous solution and the soluble aluminum salt aqueous solution are fed simultaneously and continuously in a second stage and subjected to a double decomposition salt-forming reaction. The presence of the soluble flocculant helps prevent the particles formed in the subsequent reaction from being too large or too small, making the product crystallization process more compact and the product particle distribution more uniform, thereby achieving the polymer additive meeting specific particle size parameters.

[0052] Preferably, the feeding time is 5-30 min, for example, it can be 6 min, 8 min, 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, 25 min or 28 min, 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 10-20 min is further preferred.

[0053] Preferably, the temperature of the first stage reaction is 20-90°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, 75°C, 80°C or 85°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, and 40-85°C is further preferred.

[0054] Preferably, the reaction time is 10-60 min, for example, it can be 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min or 55 min, 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 20-40 min is further preferred.

[0055] Preferably, the time for the second-stage feeding is 1-3h, for example, it can be 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h or 2.8h, 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.

[0056] Preferably, the temperature of the second-stage reaction is 20-90°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, 75°C, 80°C or 85°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 lists the specific points included in the range, and 40-85°C is further preferred.

[0057] Preferably, the residence time of the second-stage reaction is 10-50 min, for example, it can be 12 min, 15 min, 18 min, 20 min, 22 min, 25 min, 28 min, 30 min, 32 min, 35 min, 38 min, 40 min, 42 min, 45 min or 48 min, 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 20-40 min is further preferred.

[0058] In the present invention, regardless of the one-stage feeding or the two-stage feeding, the soluble diethylphosphinate aqueous solution and the soluble aluminum salt aqueous solution are simultaneously and continuously added to the reaction device, and the feed molar ratio of the soluble aluminum salt to the soluble diethylphosphinate is 1:(5.8-6.2).

[0059] It is understood that the preparation method of the present invention adopts a continuous salt formation process. First, all the dispersed solution is added to the reaction device, and then the soluble diethyl phosphinate aqueous solution and the soluble aluminum salt aqueous solution are simultaneously and continuously fed for 5-30 minutes, and the reaction is kept at 20-90°C for 10-60 minutes; then the diethyl phosphinate aqueous solution and the soluble aluminum salt aqueous solution are simultaneously and continuously fed for 1-3 hours and a second-stage reaction is carried out. During this stage, the residence time of the feed liquid in the reaction device is 10-50 minutes, and the material is discharged to obtain a slurry containing the polymer additive.

[0060] Preferably, after the metathesis reaction is completed, a post-treatment step is further included, and the post-treatment includes filtering, washing and drying.

[0061] Preferably, the washing comprises water.

[0062] Preferably, the number of washings is 1-5 times, for example, 2 times, 3 times, 4 times, etc.

[0063] Preferably, the drying temperature is 120-200°C, for example, it can be 130°C, 140°C, 150°C, 160°C, 170°C, 180°C or 190°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.

[0064] It should be noted that the preparation of the polymer additive described in the first aspect is not limited to the preparation method provided in the second aspect of the present invention. Those skilled in the art may also select other methods or routes to obtain the polymer additive proposed in the present invention. For example, aluminum diethylphosphinate particles (aluminum diethylphosphinate particles whose particle size distribution does not meet the requirements of the present invention) can be sieved to obtain the polymer additive having specific particle size distribution parameters.

[0065] Preferably, the screening treatment device includes an air flow classifier, more preferably a two-stage air flow classifier.

[0066] In a third aspect, the present invention provides a use of the polymer additive as described in the first aspect in a polymer material.

[0067] Preferably, the polymer additive is applied to the polymer material as a flame retardant.

[0068] Preferably, the polymer material includes general plastics, general engineering plastics, special engineering plastics or elastomers.

[0069] In a fourth aspect, the present invention provides a polymer composition comprising a polymer matrix and the polymer additive according to the first aspect.

[0070] Preferably, the polymer composition comprises the following components in parts by mass:

[0071] 40-99 parts polymer matrix

[0072] The polymer additive is 2-35 parts.

[0073] Preferably, the mass parts of the polymer matrix are 40-99 parts, for example, 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.

[0074] Preferably, the mass fraction of the polymer additive is 2-35 parts, for example, it can be 4 parts, 5 parts, 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.

[0075] Preferably, the polymer matrix comprises any one of polyamide, polyester, polyurethane, styrene-based polymer, polyolefin, polyacrylate, or a combination of at least two thereof.

[0076] Preferably, the polyamide includes any one of polyamide resin and polyamide elastomer, or a combination of at least two of them.

[0077] 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 illustratively 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 illustratively 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 illustratively include but are not limited to: any one or a combination of at least two of caprolactam, capryllactam, undecane lactam, and laurolactam. The ω-amino acids illustratively 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.

[0078] Exemplarily, 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), and polyamide 10T (polydecanediamide), or a combination of at least two of them.

[0079] Illustratively, the polyamide elastomer comprises a hard segment derived from polyamide and a soft segment derived from a polyol, wherein the polyol comprises a polyether polyol and / or a polyester polyol, preferably a polyether polyol.

[0080] Preferably, the polyester comprises a condensation product of a dicarboxylic acid and / or its derivatives with 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 like; and the derivatives include acyl halides (chlorides), esters, anhydrides, etc. formed from the dicarboxylic acid. The diol exemplarily includes but is not limited to: any one or a combination of at least two of ethylene glycol, butanediol, and hexanediol.

[0081] Illustratively, the polyester includes polyethylene terephthalate (PET) and / or polybutylene terephthalate (PBT).

[0082] Preferably, the polyurethane includes polyurethane resin and / or polyurethane elastomer.

[0083] Preferably, the polyurethane comprises a reaction product of a polyol and an isocyanate, wherein the polyol illustratively includes but is not limited to: any one of polyether polyol, polyester polyol, polylactone polyol, polycarbonate polyol, or a combination of at least two thereof.

[0084] Preferably, the styrene-based polymer includes any one or a combination of at least two of a styrene homopolymer (PS), a styrene-acrylate copolymer, a styrene-olefin copolymer, and a styrene-olefin-acrylonitrile copolymer; the styrene-olefin copolymer exemplarily includes but is not limited to: any one or a combination of at least two of a styrene-(ethylene-propylene) diblock copolymer, a styrene-(ethylene-butylene)-ethylene triblock copolymer, a styrene-isoprene diblock copolymer, a styrene-isoprene-styrene triblock copolymer, and a styrene-ethylene-isoprene terpolymer.

[0085] Preferably, the polyolefin includes any one or a combination of at least two of polyethylene, α-olefin homopolymer, α-olefin copolymer, ethylene-α-olefin copolymer, and ethylene-α-olefin-diene copolymer; wherein the α-olefin exemplarily includes but is not limited to: any one or a combination of at least two of propylene, butene, pentene, hexene, heptene, and octene; the diene exemplarily includes but is not limited to: any one or a combination of at least two of butadiene, isoprene, and hexadiene.

[0086] It should be noted that the polymer composition of the present invention may further include any other additives that are added with motivation in the art.

[0087] Preferably, the polymer composition further includes 0-45 parts of reinforcing material in parts by mass, and the mass parts 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.

[0088] Preferably, the reinforcement material comprises glass fiber and / or carbon fiber.

[0089] Preferably, the polymer composition further comprises 0-40 parts of filler in parts by mass, and the mass proportion of the 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.

[0090] Preferably, the filler includes any one or a combination of at least two of silicon dioxide, talc, titanium dioxide, barium sulfate, kaolin, calcium sulfate, boehmite, mica, magnesium carbonate, and glass microspheres.

[0091] 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.

[0092] Preferably, the other additives include any one or a combination of at least two of an antioxidant, an ultraviolet absorber, a lubricant, a nucleating agent, a stabilizer, an antistatic agent, and a colorant.

[0093] Preferably, the mass fractions of the antioxidant, ultraviolet absorber, lubricant and nucleating agent in the polymer composition are each independently 0.01-2 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, 1.5 parts or 1.8 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 said range.

[0094] In a preferred technical solution, the polymer composition comprises the following components in parts by mass:

[0095] 40-99 parts polymer matrix

[0096] 2-35 parts of the polymer additive

[0097] 0-45 parts of reinforcing material.

[0098] 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 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.

[0099] The polymer additive has a flame retardant effect. Preferably, the mass percentage of the polymer additive in the polymer composition is 2%-35%, for example, it can be 4%, 5%, 6%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32% or 34%, 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.

[0100] Illustratively, the method for preparing the polymer composition includes: melt-blending the components of the polymer composition and then extruding to obtain the polymer composition.

[0101] Preferably, the polymer matrix, polymer additives, optional reinforcing materials, optional fillers, and optional other auxiliary agents are first premixed to obtain a premix; and then the premix is melt-blended and extruded to obtain the polymer composition.

[0102] Preferably, the melt blending is carried out in a screw extruder.

[0103] Preferably, the screw extruder is a twin-screw extruder.

[0104] Preferably, the temperature of the screw extruder is 180-340°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.

[0105] Preferably, the extrusion further includes granulation and drying steps.

[0106] Compared with the prior art, the present invention has the following beneficial effects:

[0107] The polymer additive provided by the present invention has a particle size distribution that satisfies the relationship between Formula I and Formula II, and has specific particle size distribution parameters, thereby achieving uniform dispersion of the polymer additive in the polymer system. This ensures that the polymer composition containing the polymer additive is free of surface defects such as discolored spots and white spots, thereby greatly improving the quality of flame-retardant polymer products. DETAILED DESCRIPTION

[0108] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0109] As used herein, the terms "comprises," "including," "having," "containing" or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a listed element 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.

[0110] The polymer additive and the preparation method thereof of the present invention will be described in detail below with reference to a number of embodiments, but the polymer additive and the preparation method thereof are not limited to these embodiments.

[0111] In the following specific embodiments, the D of the polymer additive is 10 、D 25 、D 50 、D 75 、D 97 The particle size data was obtained by referring to the particle size distribution laser diffraction method according to the standard GB / T19077-2016 and using a laser particle size analyzer (model LS-609, OMEC). The specific method is as follows: wet test, take 0.2 g of the sample to be tested, add 2 mL of ethanol to moisten the sample, and then add 10 g of water, and disperse for 2 minutes under ultrasonic assistance to obtain a dispersion; the dispersion is tested by a laser particle size analyzer, and the instrument parameters are set as follows: sample refractive index 1.6, dispersion medium refractive index 1.33, and shading rate 10%.

[0112] The content of aluminum diethylphosphinate, aluminum ethylbutylphosphinate, and aluminum ethylphosphinate in the polymer additive was determined by nuclear magnetic phosphorus spectroscopy (P-NMR). The specific method includes using a Bruker nuclear magnetic resonance (NMR) spectrometer, model AVANCENEO 400MHz. The sample needs to be digested into a liquid with a deuterated sodium hydroxide aqueous solution, and the addition ratio is 10mg / 1g. The nuclear magnetic resonance frequency is 160MHz, and the number of scans is 1024. The peak positions of different components are obtained from the NMR results, and the mass content of each component is calculated by integration.

[0113] Example 1

[0114] A polymer additive A1, prepared as follows:

[0115] (1) preparing a dispersion solution: adding deionized water (1 / 5 of the volume of the container) to the bottom of a reaction container, adding polyaluminum sulfate thereto so that the mass ratio of deionized water to polyaluminum sulfate is 1:0.01, and mixing uniformly to obtain a dispersion solution;

[0116] (2) preparing a sodium diethylphosphinate aqueous solution with a sodium diethylphosphinate concentration of 1.5 mol / kg and an aluminum sulfate aqueous solution with an aluminum sulfate concentration of 0.45 mol / kg; using a continuous salt-forming method, starting stirring, and simultaneously and continuously injecting the sodium diethylphosphinate aqueous solution and the aluminum sulfate aqueous solution into a reaction vessel containing a dispersed solution, feeding for 15 minutes, and then keeping the temperature at 60°C for 30 minutes; then simultaneously and continuously injecting the sodium diethylphosphinate aqueous solution and the aluminum sulfate aqueous solution and reacting, the feeding time is 2 hours, and the reaction residence time is 20 minutes to obtain a slurry; the temperature is controlled at 60°C during the entire reaction process, the feeding molar ratio of aluminum sulfate to sodium diethylphosphinate is 1:6; the mass ratio of the sodium diethylphosphinate aqueous solution to the polyaluminum sulfate in the dispersed solution is 1:0.0015;

[0117] The slurry was heated to 80° C. and kept warm for 5 minutes. The slurry was filtered, washed three times with 3 times the amount of water, and dried at 150° C. to obtain the polymer additive A1, which contained 2.62 mol % of ethylbutyl aluminum phosphinate and 0.49 mol % of ethyl aluminum phosphinate. The parameters related to particle size are shown in Table 1.

[0118] Example 2

[0119] A polymer additive A2, the preparation method of which differs from that of Example 1 only in that the mass of the polyaluminum sulfate in step (1) is adjusted so that the mass ratio of deionized water to the polyaluminum sulfate in the dispersed solution is 1:0.008; the mass ratio of the sodium diethylphosphinate aqueous solution to the polyaluminum sulfate in the dispersed solution is 1:0.0012; the amounts of other materials, process steps, and parameters are the same as those in Example 1, to obtain a polymer additive A2 containing 2.95 mol% of ethylbutyl aluminum phosphinate and 0.21 mol% of ethyl aluminum phosphinate; parameters related to particle size are shown in Table 1.

[0120] Example 3

[0121] A polymer additive A3, the preparation method of which differs from that of Example 1 only in that the mass of the polyaluminum sulfate in step (1) is adjusted so that the mass ratio of deionized water to the polyaluminum sulfate in the dispersed solution is 1:0.006; the mass ratio of the sodium diethylphosphinate aqueous solution to the polyaluminum sulfate in the dispersed solution is 1:0.0009; the amounts of other materials, process steps, and parameters are the same as those in Example 1, to obtain a polymer additive A3 containing 2.78 mol% of ethylbutyl aluminum phosphinate and 0.43 mol% of ethyl aluminum phosphinate; parameters related to particle size are shown in Table 1.

[0122] Example 4

[0123] A polymer additive A4, the preparation method of which differs from that of Example 1 only in that the mass of the polyaluminum sulfate in step (1) is adjusted so that the mass ratio of deionized water to the polyaluminum sulfate in the dispersed solution is 1:0.004; the mass ratio of the sodium diethylphosphinate aqueous solution to the polyaluminum sulfate in the dispersed solution is 1:0.0006; the amounts of other materials, process steps, and parameters are the same as those in Example 1, to obtain a polymer additive A4 containing 2.86 mol% of ethylbutyl aluminum phosphinate and 0.34 mol% of ethyl aluminum phosphinate; parameters related to particle size are shown in Table 1.

[0124] Example 5

[0125] A polymer additive A5, the preparation method of which differs from that of Example 1 only in that the mass of the polyaluminum sulfate in step (1) is adjusted so that the mass ratio of deionized water to the polyaluminum sulfate in the dispersed solution is 1:0.002; the mass ratio of the sodium diethylphosphinate aqueous solution to the polyaluminum sulfate in the dispersed solution is 1:0.0003; the amounts of other materials, process steps, and parameters are the same as those in Example 1, to obtain a polymer additive A5 containing 2.58 mol% of ethylbutyl aluminum phosphinate and 0.57 mol% of ethyl aluminum phosphinate; parameters related to particle size are shown in Table 1.

[0126] Example 6

[0127] A polymer additive A6, the preparation method of which differs from that of Example 1 only in that the flocculant in step (1) is adjusted to polyaluminum chloride, and the amounts of other materials, process steps and parameters are the same as those in Example 1, to obtain a polymer additive A6 containing 2.86 mol% of ethylbutyl aluminum phosphinate and 0.36 mol% of ethyl aluminum phosphinate; the parameters related to particle size are shown in Table 1.

[0128] Example 7

[0129] A polymer additive A7 was prepared by a method different from that of Example 1, wherein the concentration of the aqueous sodium diethyl hypophosphite solution in step (2) was adjusted to 1.2 mol / kg. The amounts of other materials, process steps, and parameters were the same as those of Example 1. The resulting polymer additive A7 contained 2.9 mol% of aluminum ethylbutylphosphinate and 0.34 mol% of aluminum ethylphosphinate. Parameters related to particle size are shown in Table 1.

[0130] Example 8

[0131] A polymer additive A8 was prepared by a method different from that of Example 1, wherein the concentration of the aluminum sulfate aqueous solution in step (2) was adjusted to 0.35 mol / kg. The amounts of other materials, process steps, and parameters were the same as those of Example 1. The resulting polymer additive A8 contained 2.42 mol% of aluminum ethylbutylphosphinate and 0.64 mol% of aluminum ethylphosphinate. Parameters related to particle size are shown in Table 1.

[0132] Example 9

[0133] A polymer additive A9, the preparation method of which differs from that of Example 1 in that step (2) is different, specifically as follows:

[0134] A sodium diethylphosphinate aqueous solution with a sodium diethylphosphinate concentration of 1.5 mol / kg and an aluminum sulfate aqueous solution with an aluminum sulfate concentration of 0.45 mol / kg were prepared; a continuous salt formation method was used, stirring was started, and the sodium diethylphosphinate aqueous solution and the aluminum sulfate aqueous solution were respectively and simultaneously and continuously injected into a reaction vessel containing a dispersed solution, and the feeds were directly and continuously fed for 2 hours and a reaction residence time of 20 minutes, after which a slurry was obtained; the temperature was controlled at 60° C. during the entire reaction process, and the feed molar ratio of aluminum sulfate to sodium diethylphosphinate was 1:6; the mass ratio of the sodium diethylphosphinate aqueous solution to the polyaluminum sulfate in the dispersed solution was 1:0.0015;

[0135] The slurry was heated to 80° C. and kept warm for 5 minutes. The slurry was filtered, washed three times with 3 times the amount of water, and dried at 150° C. to obtain the polymer additive A9, which contained 2.37 mol% of ethylbutyl aluminum phosphinate and 0.60 mol% of ethyl aluminum phosphinate. The parameters related to particle size are shown in Table 1.

[0136] Comparative Example 1

[0137] A polymer additive D1, the preparation method of which differs from that of Example 1 in that step (2) is different, specifically as follows:

[0138] A sodium diethylphosphinate aqueous solution with a concentration of 1.5 mol / kg and an aluminum sulfate aqueous solution with an aluminum sulfate concentration of 0.45 mol / kg were prepared; using an intermittent salt formation method, 1 mol of the sodium diethylphosphinate aqueous solution was directly added to the reaction vessel, and then a trace amount of polyaluminum sulfate was added to achieve a mass ratio of the sodium diethylphosphinate aqueous solution to the polyaluminum sulfate in the dispersed solution of 1:0.0015. Stirring was started, and the prepared aluminum sulfate solution was continuously fed into the reaction vessel at a constant rate to react. The temperature of the reaction vessel was controlled at 60° C. during the feeding period, and the feeding time was 2.5 hours. The total molar ratio of aluminum sulfate to sodium diethylphosphinate was ultimately 1:6. After the feeding was completed, a slurry was obtained; the slurry was heated to 80° C. and maintained at this temperature for 5 minutes. The slurry was filtered, washed three times with 3 times the amount of water, and dried at 150° C. to obtain the polymer additive D1, which contained 2.73 mol% of aluminum ethylbutylphosphinate and 0.39 mol% of aluminum ethylphosphinate. Parameters related to particle size are shown in Table 1.

[0139] Example 10

[0140] A polymer additive A10 was prepared as follows: the polymer additive A1 provided in Example 1 and the polymer additive D1 provided in Comparative Example 1 were mixed in a mass ratio of 1:1, and then processed using a two-stage airflow classifier, wherein the first stage classification speed was 3000 rpm for 30 minutes and the second stage classification speed was 5000 rpm for 60 minutes. Ultrafine powder and coarse particles were removed step by step to obtain the polymer additive A10. Parameters related to the particle size of the polymer additive A10 are shown in Table 1.

[0141] Comparative Example 2

[0142] A polymer additive D2, prepared as follows:

[0143] (1) Add 1 / 5 of the volume of deionized water to the bottom of the reaction vessel;

[0144] (2) preparing a sodium diethylphosphinate aqueous solution with a sodium diethylphosphinate concentration of 1.5 mol / kg and an aluminum sulfate aqueous solution with an aluminum sulfate concentration of 0.45 mol / kg; using a continuous salt formation method, the sodium diethylphosphinate aqueous solution and the aluminum sulfate aqueous solution were simultaneously and continuously injected into a reaction vessel filled with deionized water for a feeding time of 2.5 hours to obtain a slurry; the temperature was controlled at 60° C. during the entire reaction process, and the feeding molar ratio of aluminum sulfate to sodium diethylphosphinate was 1:6;

[0145] The slurry was heated to 80° C. and kept warm for 5 minutes. The slurry was filtered, washed three times with 3 times the amount of water, and dried at 150° C. to obtain the polymer additive D2, which contained 2.69 mol% of ethylbutyl aluminum phosphinate and 0.42 mol% of ethyl aluminum phosphinate. The parameters related to particle size are shown in Table 1.

[0146] Comparative Example 3

[0147] A polymer additive D3 was prepared by a method different from that of Comparative Example 2, except that the reaction temperature was controlled at 30°C. The material amounts, process steps, and other parameters were the same as those of Comparative Example 2. The resulting polymer additive D3 contained 2.46 mol% of ethylbutyl aluminum phosphinate and 0.68 mol% of ethyl aluminum phosphinate. Parameters related to particle size are shown in Table 1.

[0148] Comparative Example 4

[0149] A polymer additive D4 is prepared as follows:

[0150] (1) Add 1 / 5 of the volume of deionized water to the bottom of the reaction vessel;

[0151] (2) preparing a sodium diethylphosphinate aqueous solution with a sodium diethylphosphinate concentration of 1.5 mol / kg and an aluminum sulfate aqueous solution with an aluminum sulfate concentration of 0.45 mol / kg; using a continuous salt-forming method, injecting the sodium diethylphosphinate aqueous solution and the aluminum sulfate aqueous solution into a reaction vessel filled with deionized water simultaneously and continuously, feeding the feed for 15 minutes, and then keeping the temperature at 60°C for 20 minutes; then continuing to inject the sodium diethylphosphinate aqueous solution and the aluminum sulfate aqueous solution simultaneously and continuously and reacting, the feeding time is 2 hours, the reaction residence time is 20 minutes, and a slurry is obtained; the temperature is controlled at 60°C during the entire reaction process, and the feeding molar ratio of aluminum sulfate to sodium diethylphosphinate is 1:6;

[0152] The slurry was heated to 80° C. and kept warm for 5 minutes. The slurry was filtered, washed three times with 3 times the amount of water, and dried at 150° C. to obtain the polymer additive D4, which contained 2.53 mol% of ethylbutyl aluminum phosphinate and 0.55 mol% of ethyl aluminum phosphinate. The parameters related to particle size are shown in Table 1.

[0153] Table 1

[0154]

[0155]

[0156] 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.

[0157] Application Examples

[0158] A polyamide composition comprising the following components in parts by mass:

[0159] 61 parts of polyamide 10T

[0160] 15 parts glass fiber

[0161] 14 parts of flame retardant additives;

[0162] The brand of polyamide 10T is G-KFHP611A (Golden); the brand of glass fiber is E7CS10-03-568H (China Jushi); and the flame retardant additives are the polymer additives provided in Examples 1-9 and Comparative Examples 1-4, respectively.

[0163] The preparation method of the polyamide composition is as follows: polyamide 10T, glass fiber and flame retardant additive are mixed according to the formula to obtain a premix; the premix is added to a twin-screw extruder with a screw speed of 400 rpm and a processing temperature of 320° C., and polyamide composition particles are obtained by melt mixing and extrusion granulation.

[0164] The obtained polyamide composition pellets were tested for discoloration spots using the following method: 100 g of the pellets to be tested were visually observed for white spots on the surface of the extruded pellets. These were discoloration spots caused by uneven dispersion of the additive. The general control standard was that the size of the discoloration spots was ≤ 0.2 mm and less than 6. The test results are shown in Table 2:

[0165] Table 2

[0166] polymer additives <![CDATA[100×(D 75 -D 25 ) / (D 50 ) 2 ]]> <![CDATA[(D 97 ×D 50 ) / (D 10 ×100)]]> Different color point situation Example 1 1.64 1.04 No discoloration Example 2 1.35 0.88 No discoloration Example 3 1.27 1.16 No discoloration Example 4 1.72 1.60 ≤0.2mm 1 piece Example 5 1.71 1.96 ≤0.2mm 4 pieces Example 6 1.66 1.08 No discoloration Example 7 1.59 1.31 No discoloration Example 8 1.61 1.34 No discoloration Example 9 1.80 1.32 ≤0.2mm 5 pieces Example 10 1.55 1.20 No discoloration Comparative Example 1 1.82 1.56 ≤0.2mm 8 pieces Comparative Example 2 1.54 2.40 ≤0.2mm 15 pieces Comparative Example 3 1.21 1.84 ≤0.2mm 14 pieces Comparative Example 4 1.93 1.47 ≤0.2mm>15 pieces

[0167] According to the data in Table 2, the particle size of the polymer additives provided in Examples 1-10 of the present invention satisfies 1.1≤100×(D 75 -D 25 ) / (D 50 ) 2 ≤1.8 and 0.5≤(D 97 ×D 50 ) / (D 10×100)≤2.0, it has a specific particle size distribution and has an excellent dispersion effect in the polyamide system, making the discoloration points of the polyamide composition qualified and even making the white discoloration points completely disappear.

[0168] The particle size of the polymer additives in Comparative Examples 1-2 and 4 cannot satisfy both Formula I and Formula II, resulting in the polyamide composition containing them being unable to effectively improve the white spot situation. 50 >50 μm, the particles are too large and may lead to white spots in the polyamide composition even though they satisfy Formula I and Formula II.

[0169] The applicant declares that while the above-described embodiments illustrate the polymer additive, its preparation method, and its application, the present invention is not limited to these embodiments. This does not necessarily mean that the present invention must rely on these embodiments in order to be implemented. Those skilled in the art will understand that any improvements to the present invention, equivalent substitutions for raw materials in the present invention, addition of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A polymer additive, characterized in that The polymer additive includes aluminum diethylphosphinate, and the particle size of the polymer additive satisfies the relationship shown in Formula I and Formula II: 1.1≤100×(D 75 -D 25 ) / (D 50 ) 2 ≤1.8 Formula I; 0.5≤(D 97 ×D 50 ) / (D 10 ×100)≤2.0 Formula II; Among them, D 10 、D 25 、D 50 、D 75 、D 97 Respectively represent the particle sizes corresponding to the cumulative volume distribution percentages of the polymer additive being 10%, 25%, 50%, 75%, and 97%; The D of the polymer additive 50 The particle size is 25-50μm.

2. The polymer additive according to claim 1, characterized in that The D of the polymer additive 25 Particle size is 20-40 μm; and / or, the polymer additive D 75 Particle size is 30-70 μm; and / or, the polymer additive D 10 Particle size is 10-25 μm; and / or, the polymer additive D 97 The particle size is 40-90μm.

3. The polymer additive according to claim 1, characterized in that The polymer additive further comprises aluminum ethylbutylphosphinate and / or aluminum ethylphosphinate; Preferably, the molar percentage of ethylbutyl phosphinate aluminum in the polymer additive is ≤4%; Preferably, the molar percentage of aluminum ethylphosphite in the polymer additive is ≤1%.

4. A method for preparing a polymer additive according to any one of claims 1 to 3, characterized in that: The preparation method comprises: providing a dispersion solution comprising a combination of water and a soluble flocculant; The polymer additive is obtained by carrying out a double decomposition reaction between a soluble diethylphosphinate and a soluble aluminum salt in the presence of the dispersed solution using a continuous salt-forming process.

5. The preparation method according to claim 4, characterized in that The soluble flocculant includes polyaluminium sulfate and / or polyaluminium chloride; Preferably, the mass ratio of water to soluble flocculant in the dispersed solution is 1:(0.002-0.01).

6. The preparation method according to claim 4, characterized in that The preparation method comprises the following steps: placing the dispersed solution in a reaction device, and then simultaneously and continuously injecting a soluble diethylphosphinate aqueous solution and a soluble aluminum salt aqueous solution into the reaction device to perform a double decomposition reaction to obtain the polymer additive; Preferably, the mass ratio of the soluble diethylphosphinate aqueous solution to the soluble flocculant in the dispersed solution is 1:(0.0001-0.002); Preferably, the concentration of soluble diethylphosphinate in the soluble diethylphosphinate aqueous solution is 1-2 mol / kg; Preferably, the concentration of the soluble aluminum salt in the soluble aluminum salt aqueous solution is 0.3-0.6 mol / kg; Preferably, the soluble aluminum salt comprises aluminum sulfate and / or aluminum sulfate hydrate, and the feed molar ratio of the soluble aluminum salt to the soluble diethylphosphinate is 1:(5.8-6.2); Preferably, the temperature of the metathesis reaction is 20-90°C.

7. The preparation method according to claim 6, characterized in that The double decomposition reaction method comprises: simultaneously and continuously feeding a soluble diethylphosphinate aqueous solution and a soluble aluminum salt aqueous solution in one stage and performing a first-stage reaction, and then feeding in two stages and performing a second-stage reaction to obtain the polymer additive; Preferably, the feeding time is 5-30 min; Preferably, the temperature of the first stage reaction is 20-90°C and the time is 10-60 minutes; Preferably, the second-stage feeding time is 1-3h; Preferably, the temperature of the second-stage reaction is 20-90° C., and the residence time is 10-50 min.

8. The preparation method according to claim 4, characterized in that After the metathesis reaction is completed, the step of post-treatment is further included, and the post-treatment includes washing and drying.

9. Use of the polymer additive according to any one of claims 1 to 3 in polymer materials; 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 any one of claims 1 to 3; Preferably, the polymer composition comprises the following components in parts by mass: 40-99 parts polymer matrix 2-35 parts of the polymer additive; Preferably, the polymer matrix comprises any one of polyamide, polyester, polyurethane, styrene-based polymer, polyolefin, polyacrylate, or a combination of at least two thereof.

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