Phosphite materials, flame retardant additive compositions, flame retardant compositions, halogen-free flame retardant materials, methods of preparation and use

Abstract

The application relates to a phosphite material, a flame-retardant additive composition, a flame-retardant composition, a halogen-free flame-retardant material, a preparation method and application. The phosphite material has the following chemical formula: Al x Zn y (OH) z (HPO3)3.wH2O; wherein 1.5<=x<=2.5; 0 The phosphite material contains aluminum and zinc, has good thermal stability, and has a high foaming expansion speed at high temperature. The flame-retardant additive composition containing the phosphite material can be used to prepare a flame-retardant composition or a flame-retardant material, such as a halogen-free flame-retardant material, the use amount of the flame-retardant additive composition can be reduced, and the flame-retardant performance of the flame-retardant material can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of flame retardant technology, and in particular to phosphite materials, flame retardant additive compositions, flame retardant compositions, halogen-free flame retardant materials, preparation methods, and applications. Background Technology

[0002] Halogen-free flame retardants require a large amount to be added in applications, which not only increases material costs but also negatively impacts the material's physical properties. The addition of flame retardant synergists helps reduce the amount of flame retardant needed, thereby optimizing the material's physical properties and improving its flame-retardant effect. Traditional flame retardant synergists can reduce the amount of flame retardant used, but their thermal stability still cannot meet the high-temperature requirements of flame-retardant material processing. Summary of the Invention

[0003] Based on this, the present invention aims to provide a phosphite material, a flame retardant additive composition, a flame retardant composition, a halogen-free flame retardant material, a preparation method, and an application. By using a phosphite material containing aluminum and zinc, the flame retardant properties of the flame retardant material can be better improved.

[0004] A first aspect of this application provides a phosphite material having the following chemical formula:

[0005] Al x Zn y (OH) z (HPO3)3·wH2O

[0006] Where 1.5 ≤ x ≤ 2.5; 0 < y ≤ 1; 0 < z ≤ 1.5;

[0007] w is an integer from 0 to 4.

[0008] In some embodiments, the phosphite material satisfies one or more of the following characteristics:

[0009] The values ​​of x, y, and z satisfy: 5.5 ≤ 3x + 2y - z ≤ 6.5;

[0010] The values ​​of x and y satisfy: 1.5 ≤ x + y ≤ 2.2;

[0011] The values ​​of x and y satisfy: 0.01≤y / x≤0.1.

[0012] A second aspect of this application provides a method for preparing the phosphite material described in the first aspect, comprising the following steps:

[0013] A precursor solution was prepared by adding an aluminum ion source and a zinc ion source to an aqueous solution A containing phosphite source under continuous dispersion conditions of 80℃~90℃. The precursor solution was then reacted at 80℃~90℃ under continuous dispersion conditions, followed by solid-liquid separation, washing, and drying to obtain the phosphite material.

[0014] In some embodiments, the preparation method satisfies one or more of the following characteristics:

[0015] The addition rate of the aluminum ion source is 10–50 g / min;

[0016] The pH value of the precursor mixture is 2 to 7;

[0017] The reaction time is 2 hours to 4 hours;

[0018] The drying temperature is 150℃~220℃;

[0019] The drying time is 15h to 18h.

[0020] In some embodiments, the preparation method satisfies one or two of the following characteristics:

[0021] The aluminum ion source is selected from one or more of aluminum hydroxide, aluminum chloride, aluminum oxide, aluminum hydrated oxide, aluminum peroxide, aluminum peroxide hydrate, aluminum sulfate, hydrated aluminum sulfate, aluminum carbonate, and aluminum borate;

[0022] The zinc ion source is selected from one or more of zinc oxide, zinc chloride, zinc hydroxide, zinc hydrated oxide, zinc peroxide, zinc peroxide hydrate, zinc sulfate, hydrated zinc sulfate, zinc carbonate, and zinc borate.

[0023] A third aspect of this application provides a flame retardant additive composition comprising an alkylphosphinate and the phosphite material described in the first aspect.

[0024] In some embodiments, the flame retardant additive composition satisfies one or two of the following characteristics:

[0025] The alkylphosphinate is one or both of diethylaluminum hypophosphite and diethylzinc hypophosphite;

[0026] The mass ratio of the phosphite material to the alkylphosphinate is (0.05–0.5):1.

[0027] A fourth aspect of this application provides a flame retardant composition comprising, by weight percentage:

[0028] 40%–60% polymer,

[0029] 20%–40% glass fiber,

[0030] 0.5%–10% phosphite material, and

[0031] 5%–30% alkylphosphinates;

[0032] The phosphite material is the phosphite material described in the first aspect or the phosphite material prepared by the preparation method described in the second aspect.

[0033] The fifth aspect of this application provides the application of a phosphite material prepared by the preparation method of the phosphite material described in the first aspect or the second aspect in the preparation of flame-retardant materials.

[0034] A sixth aspect of this application provides a halogen-free flame retardant material comprising at least one of the following: the phosphite material described in the first aspect, the phosphite material prepared by the method described in the second aspect, the flame retardant additive composition described in the third aspect, and the flame retardant composition described in the fourth aspect.

[0035] The aluminum-zinc phosphite material provided in this application has good thermal stability, which is beneficial for its composite with polymer materials and does not cause the failure of flame retardant properties at processing temperatures. In addition, the phosphite material foams and expands rapidly at high temperatures, which can quickly and uniformly generate phosphoric acid to form a flame-retardant liquid film on the material surface. The phosphoric acid is further heated to generate polyphosphoric acid, which is beneficial for the dehydration, carbonization and coking process on the material surface, thereby better exerting the flame retardant effect.

[0036] The method for preparing phosphite materials provided in this application is simple and efficient. It can prepare phosphites with stable crystal structures at relatively low temperatures and normal pressure, and can achieve good high-temperature resistance.

[0037] The flame retardant additive composition provided in this application contains phosphite materials and alkyl phosphinates. These two components can work synergistically. When used in combination, they have good thermal stability, slow thermal weight loss at high temperatures, and high char residue, which is beneficial to improving flame retardant efficiency.

[0038] The flame retardant additive composition provided in this application can be used to prepare a flame retardant composition. The resulting flame retardant composition can withstand the high processing temperatures required for the processing and molding of polymer materials without damaging its flame retardant properties, and has good flame retardant performance (e.g., it can reach V-0 rating).

[0039] The halogen-free flame retardant material provided in this application contains phosphite materials, flame retardant additive compositions of phosphite materials and alkyl phosphinates, or flame retardant compositions with good thermal stability, and can reduce the amount of flame retardant additives used compared to traditional halogen-free flame retardant materials. This halogen-free flame retardant material also boasts superior flame retardant performance and lower cost. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0041] Figure 1 The X-ray diffraction (XRD) patterns of the phosphite materials in Example 1 and Comparative Example 1 of this application, where B# represents Example 1 and A# represents Comparative Example 1;

[0042] Figure 2 Scanning electron microscope (SEM) image of the phosphite material in Example 1 of this application;

[0043] Figure 3 Particle size distribution diagram of the phosphite material in Example 1 of this application;

[0044] Figure 4 Scanning electron microscope (SEM) image of the phosphite material in Comparative Example 1 of this application;

[0045] Figure 5 The particle size distribution diagram of the phosphite material in Comparative Example 1 of this application. Detailed Implementation

[0046] To facilitate understanding of the present invention, a more comprehensive description is provided below, along with preferred embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0048] the term

[0049] The term “and / or” as used herein includes any and all combinations of one or more of the related listed items.

[0050] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0051] In this invention, terms such as "multiple," "various," and "multiple times" refer to quantities greater than or equal to 2 unless otherwise specified. For example, "one or more" means one or more types.

[0052] In this invention, terms such as "preferred," "better," "more suitable," and "ideal" merely describe implementation methods or embodiments that yield better results and should be understood not to limit the scope of protection of this invention. If multiple "preferred" terms appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "preferred" term shall be independent.

[0053] In this invention, terms such as "further," "even more," and "particularly" are used for descriptive purposes and to indicate differences in content, but should not be construed as limiting the scope of protection of this invention.

[0054] In this invention, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features.

[0055] In this invention, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the distribution of selectable values ​​within a numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include numerical interval types such as percentage intervals, ratio intervals, and proportion intervals.

[0056] In this invention, unless otherwise specified, the temperature parameters are allowed to be either constant temperature or vary within a certain temperature range. It should be understood that the constant temperature treatment allows temperature fluctuations within the precision range controlled by the instrument. Fluctuations are permitted within ranges such as ±5℃, ±4℃, ±3℃, ±2℃, and ±1℃.

[0057] In this invention, if the unit of a data range is only followed by the right endpoint, it indicates that the units of the left and right endpoints are the same. For example, 3-5h means that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0058] Charcoal formation or carbonization: refers to the rapid cross-linking and coking of organic matter on the surface of a product during combustion, forming a dense carbon layer that blocks oxygen and prevents further combustion.

[0059] Flame retardant technology is a key research area in the application of polymer-containing flame retardant materials. Halogen-free flame retardants produce little smoke when heated and do not generate toxic or corrosive gases, making them a current hot topic in flame retardant technology research and application. Typical halogen-free flame retardant additives include phosphorus compounds and metal hydroxides, but these additives often have limitations. When added alone, the prepared flame-retardant polymer materials are prone to foaming and decomposition during processing, not only losing their flame-retardant ability but also potentially causing degradation and a significant decline in material performance. Meanwhile, some traditional halogen-free flame retardants require large dosages in applications, significantly increasing the cost of flame-retardant polymers. Flame retardant synergists are flame retardant additives used in combination with flame retardants. Some studies have shown that adding flame retardant synergists not only helps improve the flame-retardant efficiency of the main flame retardant but also optimizes the physical properties of the material and prevents polymer degradation and mechanical property decline during processing. Aluminum phosphite, as a flame retardant synergist, can form a foamed layer on the surface of materials during combustion. Its expanded structure can provide some thermal insulation. However, the thermal stability of aluminum phosphite still cannot meet the requirements of high-temperature processing of some polymer materials, resulting in poor overall stability. Traditional methods for preparing phosphites require high-temperature and high-pressure conditions to obtain stable phosphites with good heat resistance and flame retardant effects. This process is not only complex but also involves pressurized reactions, raising safety concerns and increasing costs.

[0060] A first aspect of this application provides a specific phosphite material containing aluminum and zinc.

[0061] The inventors of this application have developed a phosphite material through extensive experimentation. This phosphite material, a specific phosphite material containing aluminum and zinc, exhibits good thermal stability, can withstand high heat treatment temperatures without flame retardant failure, and further demonstrates rapid foaming expansion at high temperatures, stable flame retardant effect, and high char residue.

[0062] In some embodiments, a phosphite material is provided, the phosphite material having the following chemical formula:

[0063] Al x Zn y (OH) z (HPO3)3·wH2O

[0064] Where 1.5 ≤ x ≤ 2.5; 0 < y ≤ 1; 0 < z ≤ 1.5;

[0065] w is an integer from 0 to 4.

[0066] This aluminum and zinc phosphite material exhibits good thermal and structural stability. It foams and expands rapidly at high temperatures, quickly and uniformly generating phosphoric acid to form a flame-retardant liquid film on the material surface. The phosphoric acid further reacts with heat to form polyphosphoric acid, facilitating dehydration, carbonization, and coking on the material surface, thus enhancing its flame-retardant effect. This aluminum and zinc phosphite material (an alloy of aluminum and zinc phosphite, a pure substance) possesses better thermal stability and higher flame-retardant efficiency without exhibiting more stable foaming properties.

[0067] Understandably, the chemical formula of this phosphite material is a nominal composition, and the phosphite material may not be a pure substance.

[0068] Understandably, other metallic elements can also be introduced into the chemical formula of phosphite materials.

[0069] In some embodiments, the value of x in the chemical formula of the phosphite material satisfies: 1.5 ≤ x ≤ 2.5, further can be 1.8 ≤ x ≤ 2.2, and even further can be 2 ≤ x ≤ 2.2. x can also be selected from one or any interval consisting of two of the following values: 1.5, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, 1.6, 1.6, 1.61. 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69, 1.7, 1.7, 1.71, 1.72, 1.73, 1.74, 1.75, 1.76, 1.77, 1.78, 1.79, 1.8, 1.8, 1.81, 1.82, 1.83, 1.84, 1.85, 1.86, 1.87, 1.88, 1.89, 1.9, 1.9, 1 .91, 1.92, 1.93, 1.94, 1.95, 1.96, 1.97, 1.98, 1.99, 2, 2.0, 2.01, 2.02, 2.03, 2.04, 2.05, 2.06, 2.07, 2.08, 2.09, 2.1, 2.1, 2.11, 2.12, 2.13, 2.14, 2.15, 2.16, 2.17, 2.18, 2.19, 2.2, 2.2 Values ​​2.21, 2.22, 2.23, 2.24, 2.25, 2.26, 2.27, 2.28, 2.29, 2.3, 2.31, 2.32, 2.33, 2.34, 2.35, 2.36, 2.37, 2.38, 2.39, 2.4, 2.41, 2.42, 2.43, 2.44, 2.45, 2.46, 2.47, 2.48, 2.49, and 2.5, etc. A more suitable value for x is more beneficial to improving the flame retardant properties of phosphite materials. If the value of x in the structural formula of phosphite materials is too high, it may cause the phosphite structure to be unstable and prone to collapse at high temperatures, resulting in poor foaming or flame retardant properties. If the value of x in the structural formula of phosphite materials is too low, it may cause the phosphite skeleton structure to be too dense, resulting in insufficient product expansion at high temperatures and affecting flame retardant efficiency.

[0070] In some embodiments, the value of y in the chemical formula of the phosphite material satisfies: 0 < y ≤ 1, further can be 0.02 ≤ y ≤ 0.2, and even further can be 0.02 ≤ y ≤ 0.12. y can also be selected from one or any two of the following values ​​or an interval consisting of any two values: 0.001, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0. 7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, and 1, etc. A more suitable value for y is more beneficial to improving the flame retardant properties of phosphite materials. If the value of y in the structural formula of a phosphite material is too high, it may result in poor overall high-temperature resistance and decreased flame retardant properties; if the value of y in the structural formula of a phosphite material is too low, it may lead to a decrease in the overall flame retardant effect of the product.

[0071] In some embodiments, the value of z in the chemical formula of the phosphite material satisfies: 0 < z ≤ 1.5, further can be 0 < z ≤ 0.5, and even further can be 0.74 ≤ z ≤ 0.24. z can also be selected from one or any two of the following values ​​or an interval consisting of any two values: 0.001, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22. 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0. 65, 0.66, 0.67, 0.68, 0.69, 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1. Values ​​such as 08, 1.09, 1.1, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.2, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, 1.3, 1.31, 1.32, 1.33, 1.34, 1.35, 1.36, 1.37, 1.38, 1.39, 1.4, 1.41, 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.49, and 1.5 are provided. A more suitable value for z is more beneficial for improving the flame retardant properties of phosphite materials. If the value of z in the structural formula of phosphite material is too high, it may result in an excessively high residual acid content in the product, incomplete reaction, and affect overall stability and temperature resistance. If the value of z in the structural formula of phosphite material is too low, it may result in an excessively high content of crystal water inside the crystal, leading to poor stability of the crystal skeleton structure, easy collapse at high temperatures, and a decrease in flame retardant performance.

[0072] In some embodiments, in the chemical formula of the phosphite material, w is an integer from 0 to 4, further can be an integer from 1 to 4, and even further can be an integer from 2 to 4, or can be selected from any one value or any interval consisting of two values ​​from 0, 1, 2, 3, and 4, such as 1 to 4, 2 to 3, etc. A more suitable value of w is more conducive to improving the flame retardant performance of the phosphite material. If the value of w in the structural formula of the phosphite material is too high, it may result in a higher water content, leading to more severe phosphite agglomeration, which is not conducive to problems such as dispersibility during storage or subsequent processing and utilization.

[0073] In some embodiments, the w in the chemical formula of the phosphite material may also be selected from one or any two of the following values ​​or a range consisting of any two values: 0.001, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, and 4, such as 1.8–3.9, 1.5–3.8, 1.2–4, etc.

[0074] In some embodiments, the chemical formula of the phosphite material contains 1.8 ≤ x ≤ 2.2, 0.02 ≤ y ≤ 0.2, 0 < z ≤ 0.5, and w is an integer from 1 to 4.

[0075] In some embodiments, the chemical formula of the phosphite material contains 1.8≤x≤2.2, 0.3≤y≤0.5, 0<z≤0.5, and w is an integer from 1 to 4.

[0076] In some embodiments, the chemical formula of the phosphite material contains 1.8≤x≤2.2, 0.52≤y≤0.7, 0<z≤0.5, and w is an integer from 1 to 4.

[0077] In some embodiments, in the chemical formula of the phosphite material, 2≤x≤2.2, 0.02≤y≤0.12, 0.04≤z≤0.24, and w is an integer from 2 to 4.

[0078] In some embodiments, the chemical formula of the phosphite material contains 2≤x≤2.2, 0.02≤y≤0.2, 0.01≤z≤0.42, and w is an integer from 2 to 4.

[0079] In some embodiments, in the chemical formula of the phosphite material, 2≤x≤2.2, 0.12≤y≤0.2, 0.01≤z≤0.42, and w is an integer from 1 to 3.

[0080] In some embodiments, the values ​​of x, y, and z in the chemical formula of the phosphite material satisfy: 5.5≤3x+2y-z≤6.5, further, 5.6≤3x+2y-z≤6.4, and even further, 5.2≤3x+2y-z≤6.2. The value of 3x+2y-z can also be selected from one of the following values ​​or any interval consisting of two of the following values: 5.5, 5.6, 5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, and 6.5, etc.

[0081] In some embodiments, the values ​​of x and y in the chemical formula of the phosphite material satisfy: 1.5 ≤ x + y ≤ 2.2, further can be 2 ≤ x + y ≤ 2.15, and even further can be 2.02 ≤ x + y ≤ 2.12. The sum of the values ​​of x and y (i.e., x + y) can also be selected from one or any two of the following values ​​or an interval consisting of any two values: 1.5, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, 1.6, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69, 1.7, 1.71, 1.72, 1 .73, 1.74, 1.75, 1.76, 1.77, 1.78, 1.79, 1.8, 1.81, 1.82, 1.83, 1.84, 1.85, 1.86, 1.87, 1.88, 1.89, 1.9, 1.91, 1.92, 1.93, 1.94, 1.95, 1.96, 1.97, 1.98, 1.99, 2, 2.01, 2.02, 2.03, 2.04, 2.05, 2.06, 2.07, 2.08, 2.09, 2.1, 2.11, 2.12, 2.13, 2.14, 2.15, 2.16, 2.17, 2.18, 2.19, 2.2, etc. A more suitable value for x+y is more conducive to improving the flame retardant properties of phosphite materials.

[0082] In some embodiments, the values ​​of x and y in the chemical formula of the phosphite material satisfy the condition: 0.15 ≤ x + y ≤ 2.2.

[0083] In some embodiments, the values ​​of x and y in the chemical formula of the phosphite material satisfy the condition: 0.15 ≤ x + y ≤ 2.15.

[0084] In some embodiments, the values ​​of x and y in the chemical formula of the phosphite material satisfy the condition: 0.15 ≤ x + y ≤ 2.12.

[0085] In some embodiments, the values ​​of x and y in the chemical formula of the phosphite material satisfy the condition: 0.18 ≤ x + y ≤ 2.12.

[0086] In some embodiments, the values ​​of x and y in the chemical formula of the phosphite material satisfy: 0.01≤y / x≤0.2, that is, the elemental ratio of Zn to Al is 0.01 to 0.2.

[0087] In some embodiments, the values ​​of x and y in the chemical formula of the phosphite material satisfy: 0.01≤y / x≤0.1, that is, the elemental ratio of Zn to Al is 0.01 to 0.1.

[0088] In some embodiments, the values ​​of x and y in the chemical formula of the phosphite material satisfy: 0.01 ≤ y / x ≤ 0.1, further preferably 0.01 ≤ y / x ≤ 0.08, and even further preferably 0.01 ≤ y / x ≤ 0.06. They can also be selected from one or a range of two values: 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, and 0.06. A more suitable value for y / x is more beneficial for improving the flame retardant properties of the phosphite material. If this value is too high or too low, it may cause poor foaming performance of the phosphite material or changes in the rate of dehydration and carbonization upon heating, thereby affecting its flame retardant characteristics.

[0089] A second aspect of this application provides a method for preparing a phosphite material, which can be used to prepare the phosphite material described in the first aspect. The preparation method includes the following steps: adding an aluminum ion source and a zinc ion source to an aqueous solution A containing a phosphite source to obtain a precursor solution; subjecting the precursor solution to a metathesis reaction; separating the solid and liquid components; washing; and drying to obtain the phosphite material.

[0090] In some embodiments, a method for preparing a phosphite material is provided, comprising the following steps:

[0091] A precursor solution is prepared by adding an aluminum ion source and a zinc ion source to an aqueous solution containing phosphite source under mixing temperature T1 (e.g., 80℃~90℃) and continuous dispersion conditions. The precursor solution is then reacted at a reaction temperature T2 (e.g., 80℃~90℃) under continuous dispersion conditions. After solid-liquid separation, washing, and drying, the phosphite material is obtained.

[0092] The preparation method of this phosphite material is simple and efficient, and it can prepare phosphites with stable crystal structure at low temperature and normal pressure, achieving good high temperature resistance.

[0093] In some embodiments, the preparation method includes the following steps:

[0094] A precursor solution was prepared by adding an aluminum ion source and a zinc ion source to an aqueous solution A containing phosphite source under continuous dispersion conditions of 80℃~90℃. The precursor solution was then reacted at 80℃~90℃ for a suitable time under continuous dispersion conditions. After solid-liquid separation, washing, and drying at a suitable temperature for a suitable time, the phosphite material was obtained.

[0095] In some embodiments, the system temperature in the preparation method is 80℃~90℃, further 80℃~88℃, and even further 80℃~85℃, or selected from one or any two of the following temperature ranges: 80℃, 81℃, 82℃, 83℃, 84℃, 85℃, 86℃, 87℃, 88℃, 89℃, and 90℃, etc. A more suitable system temperature is more conducive to improving the reaction rate of phosphorous acid with metal ion-containing materials. If the system temperature is too high, the reaction degree may be too high, resulting in unstable product characteristics and even safety risks; if the system temperature is too low, the synthesized phosphite crystal structure may have poor stability and poor product performance.

[0096] In some embodiments, the aluminum ion source is added at a rate of 10–50 g / min, more specifically 20–40 g / min, and even more specifically 30 g / min. It can also be selected from one or any two of the following rates: 10 g / min, 15 g / min, 20 g / min, 25 g / min, 30 g / min, 35 g / min, 40 g / min, 45 g / min, and 50 g / min.

[0097] In some embodiments, the pH value of the precursor mixture in the preparation method is 2-7, more specifically 2-5, and even more specifically 3. It can also be selected from one or any two of the following values: 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, and 7. A more suitable pH value for the precursor mixture is more conducive to improving the reaction rate between phosphorous acid and materials containing metal ions. If the pH value of the precursor mixture is too high, it may result in an excessively high content of water of crystallization in the phosphite structure, leading to insufficient stability of the product performance; if the pH value of the precursor mixture is too low, it may result in an excessively high residual acid value on the surface of the phosphite, affecting the product processing performance.

[0098] In some embodiments, the reaction time in the preparation method is 2h to 4h, more specifically 2h to 3h, and even more specifically 2.5h to 3h. It can also be selected from one or any two of the following time intervals: 2h, 2.5h, 3h, 3.5h, and 4h. A more suitable reaction time is more beneficial for improving the crystal form and performance stability of the phosphite. If the reaction time is too short, it may lead to insufficient product maturation, potentially resulting in a deviation in the overall stability of the crystal.

[0099] In some embodiments, the drying temperature in the preparation method is 180℃~220℃, further 190℃~210℃, and even further 200℃~210℃, or selected from one or any two of the following temperatures: 180℃, 185℃, 190℃, 195℃, 200℃, 205℃, 210℃, 215℃, and 200℃, etc.

[0100] In some embodiments, the drying time in the preparation method is 15h to 18h, further 15h to 17h, and even further 15h to 16h. It can also be selected from one or any two of the following time intervals: 15h, 15.5h, 16h, 16.5h, 17h, 17.5h, and 18h.

[0101] In some embodiments, the preparation method includes the following steps:

[0102] A precursor solution was prepared by adding aluminum ion source and zinc ion source to an aqueous solution A containing phosphite source under continuous dispersion conditions at 80℃~90℃. The precursor solution was then reacted at 80℃~90℃ for 2h~4h under continuous dispersion conditions. After solid-liquid separation, washing, and drying at 180℃~220℃ for 15h~18h, the phosphite material was obtained.

[0103] In some embodiments, the phosphorous acid source in the preparation method is selected from one or more of phosphorous acid, alkali metal phosphite materials, alkaline earth metal phosphite materials, and hypophosphite.

[0104] In some embodiments, in the preparation method, when the phosphorous acid source includes phosphorous acid, the purity of the phosphorous acid is ≥97%, further ≥98%, and even further ≥99%.

[0105] In some embodiments, the preparation method includes an aqueous solution A containing a phosphite source, which is formed by mixing a phosphite source with water; the phosphite accounts for 40wt% to 60wt% of the aqueous solution by mass percentage, more specifically 45wt% to 60wt%, and even more specifically 45wt% to 50wt%, and may also be selected from one or any two of the following mass percentages or ranges: 40wt%, 42wt%, 44wt%, 45wt%, 46wt%, 48wt%, 50wt%, 50wt%, 52wt%, 54wt%, 55wt%, 56wt%, 58wt%, and 60wt%, etc.

[0106] In some embodiments, when the aqueous solution A containing phosphite is a mixture of phosphorous acid and water, the phosphorous acid accounts for 40wt% to 60wt% of the aqueous solution A, more specifically 40wt% to 55wt%, and even more specifically 45wt% to 50wt%. A more suitable phosphorous acid content is more beneficial for improving the reaction rate between phosphite and materials containing metal ions. If the phosphorous acid content is too high, it may cause crystal twinning and deviations in product stability; if the phosphorous acid content is too low, it may lead to excessively high costs and excessively high phosphorus-containing wastewater content.

[0107] In some embodiments, the preparation method further includes adding an acid solution to the aqueous solution A containing phosphite. Understandably, the purpose of adding the acid solution is to regulate the system environment, and there are no specific requirements regarding the type of acid used.

[0108] In some embodiments, the acid solution in the preparation method is selected from one or more of hydrochloric acid, sulfuric acid, nitric acid, or organic acids.

[0109] In some embodiments, the aluminum ion source in the preparation method is selected from one or more of aluminum hydroxide, aluminum chloride, aluminum oxide, aluminum hydrated oxide, aluminum peroxide, aluminum peroxide hydrate, aluminum sulfate, hydrated aluminum sulfate, aluminum carbonate, and aluminum borate.

[0110] In some embodiments, the aluminum ion source can be hydrolyzed to generate aluminum ions in the preparation method.

[0111] In some embodiments, when the aluminum ion source comprises aluminum hydroxide, the average particle size of the aluminum hydroxide is 1 μm to 20 μm, more specifically 5 μm to 15 μm, and even more specifically 8 μm to 10 μm. A suitable average particle size of aluminum hydroxide is beneficial for improving the reaction rate in the preparation of phosphite materials.

[0112] Unless otherwise specified, the average particle size referred to in this application is 10 μm (micrometer).

[0113] In some embodiments, the zinc ion source in the preparation method is selected from one or more of zinc oxide, zinc chloride, zinc hydroxide, zinc hydrated oxide, zinc peroxide, zinc peroxide hydrate, zinc sulfate, hydrated zinc sulfate, zinc carbonate, and zinc borate.

[0114] In some embodiments, the zinc ion source can be hydrolyzed to generate zinc ions in the preparation method.

[0115] In some embodiments, when the zinc ion source comprises zinc oxide, the average particle size of the zinc oxide is 5 μm to 50 μm, more specifically 5 μm to 20 μm, and even more specifically 10 μm to 15 μm. A suitable average particle size of zinc oxide is beneficial for improving the reaction rate in the preparation of phosphite materials.

[0116] When aluminum phosphite is used alone as a flame retardant synergist in combination with alkyl phosphinates, its thermal stability is not high enough, and it will produce gases such as PH3 under processing temperature conditions. Moreover, aluminum phosphite is weak in promoting char formation of materials, resulting in a low amount of char residue after combustion of flame retardant materials, which leads to low flame retardant efficiency.

[0117] A third aspect of this application provides a flame retardant additive composition comprising an alkylphosphinate and the phosphite material described in the first aspect.

[0118] This flame retardant additive composition contains a blend of phosphite materials and flame retardants such as alkyl phosphinates. The phosphite materials and alkyl phosphinates work synergistically, resulting in good overall flame retardant efficiency of the composition. This flame retardant additive composition also exhibits good temperature resistance and is not easily decomposed during blending with polymer materials, thus maintaining good thermal stability. It demonstrates high flame retardant efficiency and stable char residue during combustion.

[0119] In some embodiments, the alkylphosphinate in the flame retardant additive composition is one or both of diethylaluminum hypophosphite and diethylzinc hypophosphite.

[0120] In some embodiments, the mass ratio of the phosphite material to the alkylphosphinate in the flame retardant additive composition is (0.05–0.5):1, more further (0.1–0.3):1, and even more further 0.2:1. It can also be selected from one or any two of the following mass ratios or a range thereof: 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, 0.11:1, 0.12:1, 0.13:1, 0.14:1, 0.15:1, 0.16:1, 0.17:1, 0.18:1, 0.19: 1, 0.2:1, 0.21:1, 0.22:1, 0.23:1, 0.24:1, 0.25:1, 0.26:1, 0.27:1, 0.28:1, 0.29:1, 0.3:1, 0.31:1, 0.32:1, 0.33:1, 0.34:1, 0.35:1, 0.36:1, 0.37:1, 0.38:1, 0.39:1, 0.4:1, 0.41:1, 0.42:1, 0.43:1, 0.44:1, 0.45:1, 0.46:1, 0.47:1, 0.48:1, 0.49:1, and 0.5:1, etc.

[0121] In some embodiments, the flame retardant additive composition has a 1% thermal weight loss temperature of 375°C or greater in a 99% nitrogen atmosphere, further comprising 380°C, and even further comprising 390°C, and may also be selected from the following temperatures: 375°C, 376°C, 377°C, 378°C, 379°C, 380°C, 381°C, 382°C, 383°C, 384°C, 385°C, 386°C, 387°C, 388°C, and 390°C.

[0122] In some embodiments, the flame retardant additive composition has a 2% thermal weight loss temperature of 400°C or greater in a 99% nitrogen atmosphere, further comprising 405°C, and even further comprising 410°C, and may also be selected from one or any two of the following temperature ranges: 400°C, 401°C, 402°C, 403°C, 404°C, 405°C, 406°C, 407°C, 408°C, 409°C, and 410°C, etc.

[0123] In some embodiments, the char residue of the flame retardant additive composition in a 99% nitrogen atmosphere is greater than or equal to 35 wt%, further can be 38 wt%, and even further can be 40 wt%, and can also be selected from one or any two of the following temperature ranges: 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, and 40 wt%.

[0124] A fourth aspect of this application provides a flame retardant composition comprising, by weight percentage:

[0125] 40%–60% polymer,

[0126] 20%–40% glass fiber,

[0127] 0.5%–10% phosphite material, and

[0128] 10%–30% alkylphosphinates;

[0129] The phosphite material is the phosphite material described in the first aspect or the phosphite material prepared by the preparation method described in the second aspect.

[0130] This flame retardant composition contains phosphite materials that are compatible with alkyl phosphinates, thus exhibiting good flame retardancy. Both phosphite and alkyl phosphinates possess high temperature resistance, meeting the requirements of high-temperature polymer processing. Therefore, this flame retardant composition exhibits good thermal stability and flame retardant properties. Furthermore, it can reduce the amount of flame retardants such as alkyl phosphinates used, helping to maintain the original properties of the polymer material.

[0131] In some implementations, the halogen-free flame retardant material comprises, by mass percentage, 40% to 60% polymer, further 42% to 58%, and even further 45% to 55%, and may also be selected from the following mass percentages or ranges consisting of one or two mass percentages: 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, and 60%, etc.

[0132] In some implementations, the halogen-free flame retardant material comprises, by weight percentage, 20% to 40% glass fiber, further 22% to 38%, and even further 25% to 35%, and may also be selected from one or two weight percentages: 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, and 40%, etc.

[0133] In some implementations, the halogen-free flame retardant material comprises, by mass percentage, 0.5% to 10% phosphite material, further comprising 2% to 8%, and even further comprising 3% to 6%, and may also be selected from one or a range of two mass percentages:

[0134] In some implementations, the halogen-free flame retardant material comprises, by mass percentage, 10% to 30% alkylphosphinate, and further, may be selected from one or more of the following mass percentages or ranges of two mass percentages: 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, and 30%, etc.

[0135] In some implementations, the halogen-free flame retardant material comprises a polymer. Further, the polymer may include at least one of polyamide (such as nylon, and more specifically, nylon 66, nylon 6, high-temperature nylon, etc.), polyester, etc.

[0136] In some implementations, the polymer comprises nylon, and may further be nylon.

[0137] In some implementations, the polymer includes nylon 66 (PA66).

[0138] In some implementations, the polymer comprises nylon 6 (PA6).

[0139] Understandably, the halogen-free flame retardant material can also be used in other types of flame retardant applications, such as cotton fabrics and plastic products.

[0140] In some embodiments, the flame retardant composition is tested according to the UL94 standard, and the flame retardant performance of the flame retardant composition reaches the UL94 V-0 level;

[0141] The phosphite material accounts for 1% to 10% of the flame retardant material by mass percentage.

[0142] The fifth aspect of this application provides the application of a phosphite material prepared by the preparation method of the phosphite material described in the first aspect or the second aspect in the preparation of flame-retardant materials.

[0143] Using this phosphite material to prepare flame-retardant compound can not only effectively improve the flame-retardant efficiency of the flame retardant and reduce the overall amount of flame retardant used, but also help improve the comprehensive performance of the flame-retardant polymer.

[0144] A sixth aspect of this application provides a halogen-free flame retardant material comprising at least one of the following: the phosphite material described in the first aspect, the phosphite material prepared by the method described in the second aspect, the flame retardant additive composition described in the third aspect, and the flame retardant composition described in the fourth aspect.

[0145] This halogen-free flame retardant material contains phosphite materials, flame retardant additive compositions or flame retardant compositions in combination with alkyl phosphinates, which have good thermal stability and help broaden the processing options for flame retardant materials, such as composite polymers that require high-temperature processing. Compared with traditional halogen-free flame retardant materials, it can reduce the amount of flame retardant additives used, obtain better flame retardant performance and reduce costs.

[0146] In some embodiments, the halogen-free flame retardant material comprises a polymer. The definition of the polymer can be found in the fourth aspect of this invention.

[0147] In some embodiments, the polymer may include one or more of polyamides (such as nylon, and further such as nylon 66, nylon 6, high-temperature nylon, etc.), polyesters, etc.

[0148] To facilitate understanding and implementation of the present invention, the following more specific and detailed embodiments and comparative examples that are easier to implement are provided for reference.

[0149] Unless otherwise specified, the raw materials used in the following experiments can be purchased from the market.

[0150] Aluminum diethylphosphinic acid, TF-9103, Zhejiang Chuanhua Huayang Chemical Co., Ltd.

[0151] Nylon 66, EPR27, China Pingmei Shenma Energy Chemical Co., Ltd.

[0152] Fiberglass, ER14-2000-988A, Jushi Group.

[0153] The testing methods and standards are as follows:

[0154] (1) Foaming height

[0155] Foaming height test method:

[0156] 1.0 g of the prepared phosphite material was spread evenly at the bottom of a 30 mL ceramic crucible and placed in a muffle furnace (Shanghai Yiheng Scientific Instruments Co., Ltd., BSX2-6-12TP) preheated to 500 °C for 1 hour. After removal, the volume change was observed and measured to evaluate the degree of foaming of the phosphite material. Specifically, the distance from the highest point of the top of the expanded residue after removal from the muffle furnace to the bottom of the crucible is the foaming height, measured in millimeters (mm).

[0157] Foaming ability grading standard:

[0158] Better: Foaming height ≥ 22mm;

[0159] Acceptable: 18mm ≤ foaming height ≤ 22mm;

[0160] Poor: Foaming height ≤18mm.

[0161] (2) Flame retardant properties of flame retardant additive compositions

[0162] Flame retardant additive composition flame retardant performance test method:

[0163] The prepared phosphite material and alkyl phosphinate were mixed in a high-speed mixer at a weight ratio of 1:4. Thermogravimetric analysis (TGA / DSC3+) was used to perform thermogravimetric analysis on the mixtures of phosphite material and alkyl phosphinate, and the 1% and 2% thermogravimetric temperatures and the char residue were calculated. Specific test conditions were: 99% nitrogen atmosphere, heating and cooling program of 10℃ / min, and temperature range of 50–600℃. Unless otherwise specified, the alkyl phosphinate used in this application for flame retardant performance testing is aluminum diethylphosphinate.

[0164] The 1% thermogravimetric temperature refers to the temperature at which the substance being tested loses 1% of its own weight during the heating process under the aforementioned atmosphere and heating procedure. The unit of the 1% thermogravimetric temperature is °C.

[0165] The 2% thermogravimetric temperature is defined as the temperature at which the substance being tested loses 2% of its own weight during the heating process under the aforementioned atmosphere and heating procedure. The unit of the 2% thermogravimetric temperature is °C.

[0166] The meaning of carbon residue is the percentage of the mass of the analyte remaining after the heating process under the aforementioned atmosphere, relative to the original mass of the analyte; the unit of carbon residue is %.

[0167] In this application, it is believed that the 1% thermal weight loss temperature, 2% thermal weight loss temperature, and char residue of the mixture obtained by thermogravimetric characterization can indicate the flame retardant properties of the flame retardant additive composition (phosphite material and alkyl phosphinate).

[0168] The flame retardant properties of the flame retardant additive compositions are shown in the table below (Table 1) standard:

[0169] Table 1.

[0170] standard <![CDATA[T 1wt％ (℃)]]> <![CDATA[T 2wt％ (℃)]]> Residual carbon content (%) better ≥375℃ ≥400℃ 35wt% qualified ≥350℃ ≥380℃ 30wt% Poor ≤350℃ ≤380℃ <20wt%

[0171] (3) Flame retardant properties of flame retardant compositions

[0172] Flame retardant composition flame retardant performance test method:

[0173] The flame retardant performance of the flame retardant composition was tested according to the UL94 standard. The V-0 to V-2 standards are shown in Table 2 below:

[0174] Table 2.

[0175] Test project level V-0 V-1 V-2 Number of samples 5 5 5 Number of times ignited 2 2 2 The maximum total flaming combustion time (s) for ten ignitions of five splines. 50 250 250 Maximum flaming time (s) for a single sample strip after each ignition. 10 30 30 Maximum flameless combustion time (s) for a single sample strip after the second ignition. 30 60 60 Flaming droplets none none have

[0176] Table 3.

[0177]

[0178] In Example 1, 1400g of phosphorous acid (purity ≥97%) was added to 1400g of water to prepare a 50% aqueous solution, which was then heated to 80°C. At this temperature, 887.9g of aluminum hydroxide (average particle size 8μm) and 9.3g of zinc oxide (average particle size 10μm) were slowly added while stirring to create a viscous solution. The solution was stirred continuously for 3 hours while maintaining the temperature at 80°C to allow crystallization to complete. The reaction slurry was then filtered and washed, and the filter cake was dried at 200°C for 16 hours to obtain a phosphite material. The chemical formula of the obtained phosphite material is Al₂Zn₄. 0.02 (OH) 0.04 (HPO3)3. Figure 1 The XRD pattern of the phosphite material prepared in Example 1 shows that it is a relatively uniform crystal, with three distinct crystal form characteristic peaks. Figure 2 The image shows the SEM image of the phosphite material prepared in Example 1. It can be seen that the phosphite material has a spherical morphology, uniform crystal morphology, and uniform particle size. Figure 3 The particle size distribution of the phosphite material in Example 1 was calculated to be Dv(50) 37.0 μm and Dv(97) 66.1 μm. Moreover, it can be seen from the figure that the particle size distribution of the phosphite material sample is relatively concentrated, which also indicates that its particle size is uniform.

[0179] Understandably, 1g of the raw material for preparing the aforementioned phosphite material is equivalent to one part by weight; the raw material in Example 1, by weight, is equivalent to the following composition: 1400 parts of phosphorous acid, 1400 parts of water, 887.9 parts (or 888 parts) of aluminum hydroxide, and 9.3 parts of zinc oxide; the composition of the raw materials used in the examples in this application can all be understood as converted by weight.

[0180] The foaming height of the phosphite material was measured to be 23 mm using the aforementioned method. Following the same method, the prepared phosphite material was mixed with aluminum diethylphosphinate at a weight ratio of 1:4 to obtain a flame retardant additive composition. The mixture was then subjected to thermogravimetric analysis (TGA) to calculate the Tf. 1wt％ The temperature is 377℃, T 2wt％ The temperature was 401℃, and the residual carbon content was 34% (see Table 3).

[0181] According to the mass percentage, 50% PA66 (Nylon 66), 30% glass fiber, 4% of the phosphite material prepared in Example 1, and 16% aluminum diethylphosphonate TF-9103 (Zhejiang Chuanhua Huayang Chemical Co., Ltd.) were mixed and added to a twin-screw extruder. The mixture was extruded at an operating temperature of 260℃~280℃, and then water-cooled, cut, and granulated to obtain a PA66-glass fiber flame retardant composition. After the flame retardant composition was thoroughly dried, the molding material was processed into 0.8mm thick strips in an injection molding machine at a material temperature of 260℃~290℃. The strips were subjected to a UL94 vertical burning test using the aforementioned method, and the test results showed that the strips met the V-0 flame retardant standard.

[0182] Example 2

[0183] The preparation method of Example 2 is basically the same as that of Example 1, except that the amount of zinc oxide added in Example 2 is different, which is changed from 9.3g to 27.8g.

[0184] The foaming height of the phosphite material was measured to be 38 mm using the same test method as in Example 1; the T of the flame retardant additive composition was... 1wt％ The temperature was 386℃, T 2wt％ The temperature was 413℃, and the residual carbon content was 42% (see Table 3).

[0185] The same method as in Example 1 was used to prepare the flame retardant composition of PA66-glass fiber, and the obtained flame retardant composition was subjected to a UL94 vertical burning test. The test results showed that the sample met the V-0 flame retardant standard.

[0186] Example 3

[0187] The preparation method of Example 2 is basically the same as that of Example 1, except that the amount of zinc oxide added in Example 2 is different, which is changed from 9.3g to 55.6g.

[0188] The foaming height of the phosphite material was measured to be 50 mm using the same test method as in Example 1; the T of the flame retardant additive composition was... 1wt％ The temperature was 393℃, T 2wt％ The temperature was 416℃, and the residual carbon content was 45% (see Table 3).

[0189] The same method as in Example 1 was used to prepare the flame retardant composition of PA66-glass fiber, and the obtained flame retardant composition was subjected to a UL94 vertical burning test. The test results showed that the sample met the V-0 flame retardant standard.

[0190] The phosphite materials prepared in Examples 1-3 exhibit good foaming properties, and the flame-retardant additive compositions obtained by mixing them with flame retardants also demonstrate good flame-retardant properties, specifically higher 1% and 2% thermal weight loss temperatures and higher char residue. The flame-retardant compositions using this phosphite material as a flame-retardant synergist exhibit good flame-retardant properties. The introduced zinc helps increase the char residue of the flame-retardant material, resulting in better thermal stability and higher flame-retardant efficiency compared to pure aluminum phosphite, without affecting or minimally affecting the foaming characteristics of aluminum phosphite. Furthermore, Examples 1-3 also demonstrate that when the aluminum content in the phosphite material is the same, appropriately increasing the zinc content can further improve its foaming properties and the flame-retardant properties of the flame-retardant additive compositions obtained by mixing it with flame retardants.

[0191] Table 4.

[0192]

[0193] Comparative Example 1

[0194] The preparation method of Comparative Example 1 is basically the same as that of Example 1, except that the amount of aluminum hydroxide and zinc oxide added is different. The amount of aluminum hydroxide added is changed from 887.9 g to 739.9 g, and the amount of zinc oxide added is changed from 9.3 g to 231.6 g. The chemical formula of the obtained phosphite material is Al. 1.67 Zn 0.68 (OH) 0.5 (HPO3)3. Figure 1 The XRD spectrum of the phosphite material prepared in Comparative Example 1 is included. The characteristic peaks in the spectrum can be partially matched with the characteristic peaks of multiple crystal forms, and there are obvious impurity peaks, indicating that the phosphite material prepared in Comparative Example 1 has a complex composition and contains multiple crystal forms as a mixed crystal phase. Figure 4 The image shows the SEM image of the phosphite material prepared in Comparative Example 1. It can be seen that although the phosphite material has a spherical morphology, the particle size is uneven, including fine particles as well as agglomerated large particles. The crystal growth is incomplete and the crystal morphology is complex. Figure 5 To compare the particle size distribution of the phosphite material in Example 1, its Dv(50) was calculated to be 20.6 μm and Dv(97) to be 161 μm. Furthermore, the figure shows that the particle size distribution of this phosphite material sample exhibits two distinct peaks, indicating that the particle size is not concentrated. Using the same testing method as in Example 1, the foaming height of this phosphite material was measured to be 16 mm; the Tf of the flame retardant additive composition... 1wt％ The temperature was 338℃, T 2wt％The temperature was 384℃, and the residual carbon content was relatively high, reaching 49% (see Table 4). The foaming height of the phosphite material in Comparative Example 1 was slightly lower than that in Examples 1-3. The possible reason is that the zinc content was higher and the aluminum content was lower, resulting in a higher density of the phosphite structure and poorer overall foaming performance of the product. At the same time, the temperature resistance of the phosphite in Comparative Example 1 was lower. The main reason for this was that the excessive zinc content introduced OH-, leading to a decrease in structural toughness.

[0195] Comparative Example 2

[0196] The preparation method of Comparative Example 2 is basically the same as that of Example 1, except that the amount of aluminum hydroxide and zinc oxide added is different. The amount of aluminum hydroxide added is changed from 887.9 g to 591.9 g, and the amount of zinc oxide added is changed from 9.3 g to 463.2 g. The chemical formula of the obtained phosphite material is Al. 1.43 Zn 1.2 (OH) 0.8 (HPO3)3.

[0197] The foaming height of the phosphite material was measured to be 11 mm using the same test method as in Example 1; the T of the flame retardant additive composition was... 1wt％ The temperature is 320℃, T 2wt％ The temperature was 376℃, and the residual char content was 37% (see Table 4). The foaming height of the phosphite material in Comparative Example 2 was significantly lower than that in Examples 1-3, and also inferior to that in Comparative Example 1. This may be because the higher zinc content led to a decrease in the overall foaming performance of the phosphite. The flame retardant additive composition obtained by mixing the phosphite material of Comparative Example 2 with aluminum diethylphosphonate had lower flame retardant performance than that of Comparative Example 1. This may be because the flame retardant performance of the product further decreased with a further increase in zinc content. At the same time, the temperature resistance of Comparative Example 2 also further decreased.

[0198] Comparative Example 3

[0199] The preparation method of Comparative Example 3 is basically the same as that of Example 2, except that the amount of aluminum hydroxide added in Comparative Example 3 is different, changing from 887.9 g to 870.1 g. The chemical formula of the obtained phosphite material is Al. 1.96 Zn 0.06 (HPO3)3.

[0200] The foaming height of the phosphite material was measured to be 17 mm using the same test method as in Example 1; the T of the flame retardant additive composition was... 1wt％ The temperature was 393℃, T 2wt％The temperature was 409℃, and the residual char content was 31% (see Table 4). The foaming height of the phosphite material in Comparative Example 3 was significantly lower than that in Examples 1-3. This may be because the zinc content was low, and the overall zinc-aluminum ratio of metal ions was easily imbalanced during the synthesis process, resulting in insufficient structural stability. The measured residual char content of the flame retardant additive composition obtained by mixing the phosphite material of Comparative Example 3 with aluminum diethylphosphinate was lower than that in Examples 1-3, which may be related to the relatively low zinc content in the phosphite material.

[0201] Comparative Example 4

[0202] The preparation method of Comparative Example 4 is basically the same as that of Example 1, except that zinc oxide was not added in Comparative Example 4, and the amount of aluminum hydroxide added is different, changing from 9.3g to 925g.

[0203] The foaming height of the phosphite material was measured to be 18 mm using the same test method as in Example 1; the T of the flame retardant additive composition was... 1wt％ The temperature is 364℃, T 2wt％ The temperature was 390°C, and the char residue was 19% (see Table 4). The foaming height of the phosphite material in Comparative Example 4 was significantly lower than that in Examples 1-3. The possible reason is that the phosphite contains only aluminum and no zinc, resulting in a less dense carbon layer structure formed under heating conditions. Consequently, the char residue of the flame retardant additive composition of aluminum phosphite and diethyl phosphite was lower than that in Examples 1-3 under the same test, and the flame retardant effect was worse.

[0204] Comparative Example 5

[0205] The preparation method of Comparative Example 5 is basically the same as that of Example 1, except that aluminum hydroxide was not added in Comparative Example 5, and the amount of zinc oxide added was changed from 9.3g to 923.4g. The chemical formula of the obtained phosphite material is Zn2(OH)2(HPO3).

[0206] The foaming height of the phosphite material was measured to be 5 mm using the same test method as in Example 1; the T of the flame retardant additive composition was... 1wt％ The temperature was 334℃, T 2wt％ At 350℃, the residual char content was 19% (see Table 4). The foaming height of the phosphite material in Comparative Example 5 was significantly lower. This may be because the phosphite contains only zinc, which has poor expansion under heat. The aluminum-free phosphite skeleton is too dense, resulting in insufficient expansion of the product at high temperatures. Furthermore, the temperature corresponding to the residual char content of the flame retardant additive composition of this phosphite material mixed with diethylphosphite, as tested under the same conditions, was significantly lower than that in Examples 1-3 and also significantly lower than that in Comparative Examples 1-4. This may be because zinc phosphite has poor temperature resistance and flame retardant ability, resulting in a lower residual char content under the same conditions.

[0207] The comparison of Comparative Examples 1 to 5 shows that when the aluminum content in phosphite materials is reduced, even if the zinc content is increased (Comparative Examples 1 to 3), the foaming performance of the resulting phosphite materials still decreases (the foaming height decreases). When only aluminum or only zinc is present, the foaming performance of the resulting phosphite materials also decreases. The foaming performance is even worse when aluminum is not present. Moreover, when only aluminum phosphite or zinc phosphite is present, the flame retardant effect is poor and the char residue is low.

[0208] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0209] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A phosphite material, characterized in that, The phosphite material has the following chemical formula: Al x Zn y (OH) z (HPO3)3·wH2O Wherein, 1.8≤x≤2.2; 0<y≤1; 0<z≤1.5; 3x+2y-z=6; w is an integer between 0 and 4.

2. The phosphite material according to claim 1, characterized in that, It meets one or more of the following characteristics: （1）x=2； （2）0.02≤y≤0.2； (3) The values ​​of x and y satisfy: 2.02≤x+y≤2.2; (4) The values ​​of x and y satisfy: 0.01≤y / x≤0.

1.

3. A method for preparing the phosphite material according to claim 1 or 2, characterized in that, Includes the following steps: A precursor solution was prepared by adding an aluminum ion source and a zinc ion source to an aqueous solution A containing phosphite source under continuous dispersion conditions at 80℃~90℃. The precursor solution was then reacted at 80℃~90℃ under continuous dispersion conditions, followed by solid-liquid separation, washing, and drying to obtain the phosphite material.

4. The preparation method according to claim 3, characterized in that, It meets one or more of the following characteristics: (1) The addition rate of the aluminum ion source is 10~50 g / min; (2) The pH value of the precursor solution is 2~7; (3) The reaction time is 2 h to 4 h; (4) The drying temperature is 150℃~220℃; (5) The drying time is 15 h to 18 h.

5. The preparation method according to claim 3, characterized in that, It satisfies one or two of the following characteristics: The aluminum ion source is selected from one or more of aluminum hydroxide, aluminum chloride, aluminum oxide, aluminum hydrated oxide, aluminum peroxide, aluminum peroxide hydrate, aluminum sulfate, hydrated aluminum sulfate, aluminum carbonate, and aluminum borate; The zinc ion source is selected from one or more of zinc oxide, zinc chloride, zinc hydroxide, zinc hydrated oxide, zinc peroxide, zinc peroxide hydrate, zinc sulfate, hydrated zinc sulfate, zinc carbonate, and zinc borate.

6. A flame retardant additive composition, characterized in that, Includes alkylphosphinates and phosphite materials as described in claim 1 or 2.

7. The flame retardant additive composition according to claim 6, characterized in that, It meets one or two of the following characteristics: The alkylphosphinate is one or both of diethylaluminum hypophosphite and diethylzinc hypophosphite; The mass ratio of the phosphite material to the alkylphosphinate is (0.05~0.5):

1.

8. A flame retardant composition, characterized in that, According to mass percentage, it includes the following components: 40%~60% polymer, 20%~40% glass fiber, 0.5%~10% phosphite material, and 5%~30% alkylphosphinates; Wherein, the phosphite material is the phosphite material according to claim 1 or 2 or the phosphite material prepared by any one of claims 3 to 5.

9. The application of the phosphite material according to claim 1 or 2 or the phosphite material according to any one of claims 3 to 5 in the preparation of flame retardant materials.

10. A halogen-free flame retardant material, characterized in that, The material comprises at least one of the following: the phosphite material according to claim 1 or 2; the phosphite material prepared by the method of any one of claims 3 to 5; the flame retardant additive composition according to claim 6 or 7; and the flame retardant composition according to claim 8.

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