Acid radical intercalation hydrotalcite-like compound of naphthalene disulfonic acid and / or derivative thereof as well as preparation method and application of acid radical intercalation hydrotalcite-like compound

Abstract

The invention discloses naphthalene disulfonic acid and / or naphthalene disulfonic acid derivative acid radical intercalation hydrotalcite as well as a preparation method and an application of the naphthalene disulfonic acid and / or naphthalene disulfonic acid derivative acid radical intercalation hydrotalcite. The chemical general formula of the naphthalene disulfonic acid and / or derivative acid radical intercalation hydrotalcite is # imgabs0 #, x is more than 0 and less than 1, A < 2-> is naphthalene disulfonic acid radical and / or naphthalene disulfonic acid derivative acid radical, M < 2 + > is selected from any one or a combination of more of magnesium, zinc, calcium and nickel, and M < 3 + > is selected from aluminum and / or iron. The naphthalene disulfonic acid and / or its derivative acid radical intercalated hydrotalcite solves the problem that the traditional hydrotalcite cannot simultaneously enhance the mechanical properties of organic polymers and improve the flame retardancy and ultraviolet light absorptivity, and provides an effective way for the high-valued development of Qinghai magnesium chloride resources. According to the invention, mechanical property maintenance, flame retardance and ultraviolet absorbability of organic polymers can be effectively realized.

Description

Technical Field

[0001] The invention belongs to the technical field of flame retardants, and in particular relates to a naphthalene disulfonic acid and / or its derivative acid radical intercalated hydrotalcite and a preparation method and application thereof. Background Art

[0002] LDHs (layered double hydroxides) is a typical anion intercalated layered compound, a general term for hydrotalcite (HT) and hydrotalcite-like compounds (HTLCs). Its layers are composed of binary or polybasic metal hydroxides, and the interlayers are filled with corresponding anions to balance the charge in the layers. The typical representative of LDHs is natural hydrotalcite (Mg 6 Al 2 (OH) 16 ·4H 2 O), other divalent (such as Mn 2+ 、Ni 2+ 、Zn 2+ etc.) and trivalent (such as Fe 3+ 、Co 3+ Cr 3+ Metal ions (such as hydrotalcite) can also form similar layered compounds, which can be collectively referred to as hydrotalcite-like compounds. The interlayer anions can be assembled into the metal hydroxide interlayer through ion exchange, direct precipitation and memory effect methods.

[0003] LDHs have unique physical and chemical properties such as light, electricity, magnetism, catalysis, and adsorption, and are widely used in catalysis and adsorption, optics, electrochemistry, corrosion resistance, UV resistance, and flame retardancy. Because of the controllability of the types and proportions of cations in the LDHs layer, and the exchangeability and intercalation of interlayer anions, the properties of LDHs are highly controllable. It is possible to design materials by selecting the anions and cations involved in LDHs according to different needs, and to achieve the functionalization of materials or modify their own functions by regulating the layer ions in LDHs according to the diversified requirements for material properties. Therefore, LDHs have great development and application potential.

[0004] The main synthesis methods of LDHs include coprecipitation, hydrothermal, ion exchange, calcination reduction and other derivative methods. Coprecipitation is one of the most commonly used methods for preparing LDHs, with the characteristics of simple operation and mild reaction conditions. Because nitrate ions are almost the most easily replaced by other anions among common anions, nitrates are mostly used for the reaction when synthesizing LDHs by coprecipitation, while chlorides and sulfates are relatively less used. However, the oxidizing property, toxicity and price of nitrates are not conducive to the large-scale production of LDHs. my country has abundant reserves of magnesium chloride resources, and the coprecipitation method for synthesizing LDHs with magnesium chloride as raw material has huge cost advantages. The hydrothermal method is a type of solvothermal method, which has the advantages of high product crystallization integrity, uniform particle size distribution, high product purity and low particle agglomeration. The disadvantages of the hydrothermal method are that it has high requirements for reaction equipment and high reaction temperature, which makes it energy-intensive, increases production costs, and is not conducive to the synthesis of some organic acid intercalated LDHs with poor stability. The ion exchange method is a method for preparing LDHs by drying the precipitate and adding the anion salt solution to be intercalated after synthesizing nitrate intercalated LDHs by coprecipitation. It also takes advantage of the fact that nitrate in nitrate intercalated LDHs is easily replaced. The ion exchange method is easier to synthesize special ion intercalated LDHs and is the most frequently used method in scientific research. Another advantage of the ion exchange method is that the synthesized LDHs can maintain the original morphology and particle size distribution of nitrate intercalated LDHs to the maximum extent, that is, the morphology of intercalated LDHs can be indirectly controlled by controlling the morphology and particle size of nitrate LDHs. Its disadvantages are complicated operation, incomplete interlayer ion replacement, poor continuous production operability, and inconvenient large-scale production. The calcination reduction method mainly utilizes the structural memory effect of LDHs. First, water and thermal decomposition products of interlayer ions are released by heating, and then the calcined oxide is placed in a solution of specific anions to re-establish the intercalation structure of LDHs, and finally obtain LDHs with corresponding anion intercalation. Its characteristics are that the interlayer anions in the synthesized LDHs are of high purity and there are no other impurity ions. The roasting reduction method is suitable for the synthesis of large guest anion intercalation LDHs. Its disadvantages are that the synthetic product may contain a certain amount of amorphous solids, high energy consumption in actual production, poor reaction continuity, and increased costs. In short, each method has its own advantages and disadvantages. Different synthesis methods can be selected for synthesis of LDHs of different values ​​and different application fields.

[0005] Organic polymer materials are widely used in production and life due to their excellent comprehensive properties, but most organic polymers are flammable, so they must be treated with flame retardant. LDHs, as an additive flame retardant, has a very broad application prospect. When natural hydrotalcite or traditional inorganic acid-intercalated magnesium-aluminum or zinc-aluminum hydrotalcite is directly added to polymer flame retardant, its performance is similar to that of magnesium hydroxide, aluminum hydroxide, etc. The flame retardant method is mainly to absorb heat through decomposition reaction and release H 2 O and CO 2 And produce an oxide layer to isolate the diffusion of combustible gas and flame retardant. The oxide produced can not only catalyze the combustible into carbon to a certain extent, but also can effectively suppress smoke by adsorbing smoke. However, in order to achieve a good flame retardant effect, a large amount of addition must be carried out, and the mechanical properties will decrease significantly at this time. There are two main ways to solve this problem. The first is to prepare LDHs with transition metal layers. LDHs containing transition metal layer metal elements have good flame retardant properties, but their synthesis generally uses nitrate as a raw material, and the preparation process has high requirements for temperature and pressure conditions, which greatly increases its production complexity and cost. The second is to prepare LDHs with special structure anion intercalation, such as organic acid groups such as gluconate and DOPO modified sulfonate. At this time, the compatibility of LDHs with organic polymers will be further increased, so that it can still maintain good mechanical properties when added in a relatively large amount. However, as far as the current technology is concerned, there are problems such as poor crystallinity of organic acid intercalation LDHs, limited improvement in flame retardant efficiency, poor mechanical property retention, and difficulty in finding suitable anions.

[0006] In summary, when natural hydrotalcite is used for flame retardancy, the addition amount is large and the mechanical properties decrease significantly. Without the use of special addition equipment, it is impossible to achieve a large addition amount (when the addition amount is large, the inorganic powder will settle in the polymer or even precipitate on the surface, which seriously affects the mechanical properties), and flame retardancy cannot be effectively achieved. When transition metals are used to prepare LDHs with high catalytic activity, the preparation process is often complicated and the cost is high, and mass production is impossible. At present, organic acid root intercalated LDHs flame retardants generally have problems such as poor crystallinity and limited flame retardancy, and further systematic research is needed. In addition, most LDHs-based flame retardants are difficult to put into practical applications due to problems such as high raw material prices or complex production processes. The design of inorganic powder fillers only strives to enhance the performance of one aspect, and cannot simultaneously achieve the flame retardant, UV resistance and other comprehensive properties of the matrix organic polymer, and cannot maintain the mechanical properties at a large addition amount. Summary of the invention

[0007] The main purpose of the present invention is to provide a naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite and its preparation method and application, so as to overcome the shortcomings of the prior art.

[0008] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0009] The embodiment of the present invention provides a naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite, the naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite having a general chemical formula of Among them, 0 <x<1,A 2- is naphthalene disulfonic acid radical and / or naphthalene disulfonic acid derivative radical, M 2+ Any one or more combinations selected from magnesium, zinc, calcium, and nickel, M 3+ Selected from aluminum and / or iron.

[0010] The present invention also provides a method for preparing the aforementioned naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite, which comprises:

[0011] At least one of the following methods is adopted: coprecipitation method, ion exchange method and roasting reduction method to prepare naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite.

[0012] The embodiment of the present invention also provides the use of the aforementioned naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite in the flame retardant of organic polymers.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite provided by the present invention can improve the flame retardancy, UV resistance and mechanical retention of the organic polymer after being added to the organic polymer;

[0015] (2) The method for preparing the naphthalene disulfonic acid and / or its derivatives intercalated hydrotalcite provided by the present invention can utilize magnesium chloride and aluminum chloride, which are abundant and inexpensive in my country, as metal ion sources, naphthalene disulfonic acid and / or its derivatives or salts thereof as anion sources, and sodium hydroxide or potassium hydroxide as alkali sources. The method is low in cost and convenient for mass production, thereby realizing high-value utilization of magnesium resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is the XRD pattern of LDHs prepared in Example 1 of the present invention;

[0018] Figure 2This is the XRD pattern of LDHs prepared in Example 2 of the present invention;

[0019] Figure 3 This is the XRD pattern of LDHs prepared in Example 3 of the present invention;

[0020] Figure 4 This is the XRD pattern of LDHs prepared in Example 4 of the present invention;

[0021] Figure 5 This is the XRD pattern of LDHs prepared in Example 5 of the present invention;

[0022] Figure 6 This is the XRD pattern of LDHs prepared in Example 6 of the present invention;

[0023] Figure 7 This is the XRD pattern of LDHs prepared in Example 7 of the present invention;

[0024] Figure 8 This is the XRD pattern of LDHs prepared in Example 8 of the present invention;

[0025] Fig. 9 This is the XRD pattern of LDHs prepared in Example 9 of the present invention;

[0026] Fig.10 This is the XRD pattern of LDHs prepared in Example 10 of the present invention;

[0027] Fig.11 This is the XRD pattern of LDHs prepared in Example 11 of the present invention;

[0028] Fig.12 The schematic diagram is a structural diagram of a hydrotalcite-like compound intercalated with naphthalene disulfonic acid and / or its derivatives in a typical embodiment of the present invention. DETAILED DESCRIPTION

[0029] In view of the defects of the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Specifically, as one aspect of the technical solution of the present invention, the chemical formula of a naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite is Among them, 0<x<1, A 2- is naphthalene disulfonic acid radical and / or naphthalene disulfonic acid derivative radical, M 2+Any one or more combinations selected from magnesium, zinc, calcium, and nickel, M 3+ Selected from aluminum and / or iron.

[0031] The characteristic of the naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite in the present invention is that it is naphthalene disulfonic acid group, which is different from naphthalene carboxylic acid group in that their acid groups are different. At the same time, the naphthalene disulfonic acid group in the present invention can increase the flame retardancy, and the divalent ions can reduce the mass fraction of the organic acid group in the LDHs, that is, the amount of the organic acid group is as small as possible, and the performance will be good.

[0032] In some preferred embodiments, the naphthalene disulfonate and / or naphthalene disulfonic acid derivative acid radicals include 1,3-naphthalene disulfonate, 1,5-naphthalene disulfonate, 1,6-naphthalene disulfonate, 2,6-naphthalene disulfonate, 2,7-naphthalene disulfonate, 6-amino-1,3-naphthalene disulfonate, 5,6-diamino-1,3-naphthalene disulfonate, 7-amino-1,3-naphthalene disulfonate, 7-hydroxy-1,3-naphthalene disulfonate, 3-amino-1,5-naphthalene disulfonate, 8-amino-1,5-naphthalene disulfonate, Acid radical, 3,6-dihydroxy-2,7-naphthalene disulfonate, 3-amino-2,7-naphthalene disulfonate, 3-amino-5-hydroxy-2,7-naphthalene disulfonate, 4-amino-5-hydroxy-2,7-naphthalene disulfonate, 1-hydroxy-3,6-naphthalene disulfonate, 2-hydroxy-3,6-naphthalene disulfonate, 1,8-dihydroxy-3,6-naphthalene disulfonate, 2-amino-4,8-naphthalene disulfonate, and any one or more combinations of 1-amino-3,8-naphthalene disulfonate, and are not limited thereto.

[0033] The schematic structural diagram of the hydrotalcite-like layer intercalated with naphthalene disulfonic acid and / or its derivatives in the present invention is as follows: Fig.11 shown.

[0034] Another aspect of the embodiments of the present invention further provides a method for preparing the aforementioned naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite, which comprises:

[0035] At least one of the following methods is adopted: coprecipitation method, ion exchange method and roasting reduction method to prepare naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite.

[0036] In some preferred embodiments, the preparation method specifically includes (co-precipitation method): reacting a first mixed reaction system comprising naphthalene disulfonic acid and / or its derivatives or alkali metal salts of naphthalene disulfonic acid and / or its derivatives, divalent metal inorganic salts, trivalent metal sources and alkaline substances to obtain naphthalene disulfonic acid and / or its derivatives acid group intercalated hydrotalcite.

[0037] Further, the naphthalene disulfonic acid and / or its derivatives include 1,3-naphthalene disulfonic acid, 1,5-naphthalene disulfonic acid, 1,6-naphthalene disulfonic acid, 2,6-naphthalene disulfonic acid, 2,7-naphthalene disulfonic acid, 6-amino-1,3-naphthalene disulfonic acid, 5,6-diamino-1,3-naphthalene disulfonic acid, 7-amino-1,3-naphthalene disulfonic acid, 7-hydroxy-1,3-naphthalene disulfonic acid, 3-amino-1,5-naphthalene disulfonic acid, 8-amino-1,5-naphthalene disulfonic acid, 3,6- Any one or more combinations of dihydroxy-2,7-naphthalene disulfonic acid, 3-amino-2,7-naphthalene disulfonic acid, 3-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 4-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 1-hydroxy-3,6-naphthalene disulfonic acid, 2-hydroxy-3,6-naphthalene disulfonic acid, 1,8-dihydroxy-3,6-naphthalene disulfonic acid, 2-amino-4,8-naphthalene disulfonic acid, and 1-amino-3,8-naphthalene disulfonic acid are also included, and are not limited thereto.

[0038] Furthermore, the naphthalene disulfonic acid and / or its derivatives include compounds and / or salts thereof in which two hydrogen atoms on the naphthalene ring are replaced by sulfonic acid groups, but are not limited thereto.

[0039] Further, the alkali metal salt of naphthalene disulfonic acid and / or its derivatives includes any one or more combinations of sodium salt of naphthalene disulfonic acid and / or its derivatives and potassium salt of naphthalene disulfonic acid and / or its derivatives, but is not limited thereto.

[0040] Furthermore, the divalent metal element in the divalent metal inorganic salt includes any one or more combinations of magnesium, copper, calcium, zinc, and manganese, but is not limited thereto.

[0041] Furthermore, the divalent metal inorganic salt includes any one or more combinations of chlorides, nitrates, and sulfates, but is not limited thereto.

[0042] Furthermore, the trivalent metal source includes any one or more combinations of trivalent metal inorganic salts, aluminum hydroxide, sodium aluminate, and sodium metaaluminate, but is not limited thereto.

[0043] Furthermore, the trivalent metal inorganic salt includes aluminum salt and / or iron salt, but is not limited thereto.

[0044] Further, the alkaline substance includes alkali metal hydroxide, but is not limited thereto.

[0045] Furthermore, the molar amount of the alkaline substance in the first mixed reaction system is 0.9×(2(n M +n A )+n O )~1.1×(2(n M +n A )+n O ), where n Mis the molar amount of the divalent metal element in the divalent metal inorganic salt, n A is the molar amount of the trivalent metal element in the trivalent metal source, n O is the molar amount of naphthalene disulfonic acid and / or its derivatives or the alkali metal salts of naphthalene disulfonic acid and / or its derivatives.

[0046] Furthermore, the molar ratio of the divalent metal element to the trivalent metal element in the first mixed reaction system is 2:1-3:1.

[0047] Furthermore, the molar ratio of the trivalent metal element to naphthalene disulfonic acid and / or its derivatives or the alkali metal salt of naphthalene disulfonic acid and / or its derivatives in the first mixed reaction system is 1:1-1:4.

[0048] Furthermore, the preparation method specifically comprises:

[0049] dissolving a divalent metal inorganic salt and a trivalent metal source in water to obtain a first solution;

[0050] dissolving naphthalene disulfonic acid and / or its derivatives or alkali metal salts of naphthalene disulfonic acid and / or its derivatives and a base in water to obtain a second solution;

[0051] And, the first solution and the second solution are mixed and reacted at 20-90° C. for 0.5-3 hours to obtain naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite.

[0052] Furthermore, the ion concentration of the divalent metal element in the first solution is 0.1-1.6 mol / L.

[0053] Furthermore, the ion concentration of the trivalent metal element in the first solution is 0.1-0.8 mol / L.

[0054] Furthermore, the concentration of effective hydroxide ions in the second solution is 0.1-4.0 mol / L.

[0055] Furthermore, the preparation method specifically comprises:

[0056] dissolving a divalent metal inorganic salt, naphthalene disulfonic acid and / or its derivatives, or an alkali metal salt of naphthalene disulfonic acid and / or its derivatives in water to obtain a third solution;

[0057] dissolving a trivalent metal source and a base in water to obtain a fourth solution;

[0058] And, the third solution and the fourth solution are mixed and reacted at 20-90° C. for 0.5-3 hours to obtain naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite.

[0059] Furthermore, the ion concentration of the divalent metal element in the third solution is 0.1-1.6 mol / L.

[0060] Furthermore, the ion concentration of the trivalent metal element in the fourth solution is 0.1-0.8 mol / L.

[0061] Furthermore, the concentration of effective hydroxide ions in the fourth solution is 0.1-4.0 mol / L.

[0062] Furthermore, the preparation method further comprises: after the reaction of the first mixed reaction system is completed, aging, washing and drying the obtained product.

[0063] Furthermore, the aging temperature is 20-200°C and the time is 3-72h.

[0064] Furthermore, the drying temperature is 20-200°C.

[0065] Furthermore, the second solution is added into the first solution at a uniform speed.

[0066] Furthermore, the fourth solution is added to the third solution at a uniform speed.

[0067] Furthermore, the first solution is added into the second solution at a uniform speed.

[0068] Furthermore, the third solution is added into the fourth solution at a uniform speed.

[0069] Furthermore, the first solution and the second solution are added into the reaction container simultaneously.

[0070] Furthermore, the third solution and the fourth solution are added into the reaction container simultaneously.

[0071] In some more specific embodiments, the co-precipitation method for preparing the naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite comprises:

[0072] (1) Solution preparation

[0073] Scheme 1: Naphthalenedisulfonic acid and / or its derivatives as organic ion source

[0074] Weigh a certain amount of substance as n M and n A divalent and trivalent metal inorganic salts to ensure that the total amount of divalent metal elements to trivalent metal elements ratio is a specified value (n M :n A=2.0~3.0), add water to prepare a mixed solution A with a certain concentration of trivalent metal ions (0~0.8mol / L). Weigh naphthalene disulfonic acid and / or its derivatives n according to a certain multiple (1~4) of the amount of the trivalent metal element. O , weigh a certain amount of alkali so that the amount of substance is (2(n M +n A )+n O )*(1±0.1), and prepare solution B with water. The concentration of effective hydroxide ions in solution B is (0.1~4.0mol / L).

[0075] Scheme 2: Alkali metal salts of naphthalene disulfonic acid and / or its derivatives as organic ion sources

[0076] At this time, due to the different ways of adding materials, two ways of adding materials (a) and (b) can be used to prepare solutions A and B.

[0077] (a) Weigh a certain amount of substance n M and n A divalent and trivalent metal inorganic salts to ensure that the total amount of divalent metal elements to trivalent metal elements ratio is a specified value (n M :n A =2.0~3.0), add water to prepare a mixed solution A with a certain concentration of trivalent metal ions (0~0.8mol / L). Weigh the alkali metal salt of naphthalene disulfonic acid and / or its derivatives according to a certain multiple (1N4) of the amount of the trivalent metal element. OA , weigh a certain amount of alkali so that its amount of substance is 2(n M +n A )*(1±0.1), and prepare solution B with water. The concentration of effective hydroxide ions in solution B is (0.1~4.0mol / L).

[0078] (b) Weigh a certain amount of substance n M The divalent metal inorganic salt is weighed according to a certain multiple (1 to 4) of the amount of the trivalent metal element, and the alkali metal salt of naphthalene disulfonic acid and / or its derivative is weighed. oA , add water to prepare a mixed solution A with a certain concentration of divalent metal ions (0-0.8 mol / L). Weigh a certain amount of substance as n A trivalent metal inorganic salts to ensure that the total amount of divalent metal elements and trivalent metal elements is the specified value (n M :n A =2.0~3.0), weigh a certain amount of alkali so that the amount of substance is 2(n M +n A)*(1±0.1), and water is used to prepare solution B, and the concentration of effective hydroxide ions in solution B is (0.1-4.0 mol / L). When synthesizing hydrotalcite-like substances using scheme 2, aluminum hydroxide and sodium aluminate can be used as aluminum sources. At this time, the amount of alkali can be appropriately reduced according to the type and amount of the added aluminum source.

[0079] (2) Reaction, aging, filtration and drying

[0080] The entire reaction can be carried out by stirring or ultrasonication with or without nitrogen protection (a portion of LDHs converted into carbonate intercalation will be used without nitrogen protection). The reaction can be added in any of the following three ways: (a) placing A in a reaction vessel, controlling the reaction temperature to a specified temperature (20-90°C), and then adding B to the A solution at a constant speed; (b) placing B in a reaction vessel, controlling the reaction temperature to a specified temperature (20-90°C), and then adding A to the B solution at a constant speed; (c) preheating the reaction vessel and keeping it warm to a specified temperature (20-90°C), and then adding the A and B solutions to the reaction vessel at a proportional speed, ensuring that the addition is started and completed at the same time. After adding the materials, continue to keep the temperature in the reactor and stir for a certain period of time (0.5 to 3 hours), then transfer to an aging container (when the aging temperature is higher than the boiling point of water, a pressure-resistant and temperature-resistant container must be used), and after aging for a certain period of time (3 to 72 hours) at a certain temperature (20 to 200 degrees Celsius), filter and wash with water until the filtrate is neutral, and then use a certain amount of water (0.1 to 2 times the volume of the reaction liquid) to excessively wash the solid to further wash away soluble impurities. The filter cake is dried to constant weight in a vacuum or nitrogen atmosphere at a certain temperature (normal temperature to 200°C), or air drying can be selected. The disadvantage is that a small part of LDHs may be converted into carbonate-intercalated hydrotalcite or partial oxidation of naphthalene disulfonic acid and its derivative acid radicals may occur at higher temperatures.

[0081] In some preferred embodiments, the preparation method specifically includes (ion exchange method):

[0082] reacting a second mixed reaction system comprising a divalent metal inorganic salt, a trivalent metal source, and an alkaline substance to obtain an inorganic acid root intercalated hydrotalcite;

[0083] And, the inorganic acid group intercalated hydrotalcite is reacted with an alkali metal salt of naphthalene disulfonic acid and / or its derivatives to obtain the naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite.

[0084] Furthermore, the divalent metal element in the divalent metal inorganic salt includes any one or more combinations of magnesium, copper, calcium, zinc, and manganese, but is not limited thereto.

[0085] Furthermore, the divalent metal inorganic salt includes any one or more combinations of chlorides, nitrates, and sulfates, but is not limited thereto.

[0086] Furthermore, the trivalent metal source includes any one or more combinations of trivalent metal inorganic salts, aluminum hydroxide, sodium aluminate, and sodium metaaluminate, but is not limited thereto.

[0087] Furthermore, the trivalent metal inorganic salt includes aluminum salt and / or iron salt, but is not limited thereto.

[0088] Further, the alkaline substance includes alkali metal hydroxide, but is not limited thereto.

[0089] Furthermore, the molar amount of the alkaline substance in the second mixed reaction system is 0.9×2(n M +n A )~1.1×2(n M +n A ), where n M is the molar amount of the divalent metal element in the divalent metal inorganic salt, n A is the molar amount of the trivalent metal element in the trivalent metal source.

[0090] Furthermore, the molar ratio of the divalent metal element to the trivalent metal element in the second mixed reaction system is 2:1-3:1.

[0091] Furthermore, the preparation method specifically comprises:

[0092] dissolving a divalent metal inorganic salt and a trivalent metal source in water to obtain a fifth solution;

[0093] dissolving an alkaline substance in water to obtain a sixth solution;

[0094] And, the fifth solution and the sixth solution are mixed and reacted at 20-90° C. for 0.5-3 h to obtain an inorganic acid intercalated hydrotalcite.

[0095] Furthermore, the ion concentration of the trivalent metal element in the fifth solution is 0.1-0.8 mol / L.

[0096] Furthermore, the ion concentration of the divalent metal element in the fifth solution is 0.1-1.6 mol / L.

[0097] Furthermore, the concentration of effective hydroxide ions in the sixth solution is 0.1-4.0 mol / L.

[0098] Furthermore, the preparation method specifically comprises:

[0099] dissolving a divalent metal inorganic salt in water to obtain a seventh solution;

[0100] dissolving a trivalent metal source and an alkaline substance in water to obtain an eighth solution;

[0101] And, the seventh solution and the eighth solution are mixed and reacted at 20-90° C. for 0.5-3 h to obtain an inorganic acid intercalated hydrotalcite.

[0102] Furthermore, the ion concentration of the divalent metal element in the seventh solution is 0.1-1.6 mol / L.

[0103] Furthermore, the ion concentration of the trivalent metal element in the eighth solution is 0.1-0.8 mol / L.

[0104] Furthermore, the concentration of effective hydroxide ions in the eighth solution is 0.1-4.0 mol / L.

[0105] Furthermore, the sixth solution is added to the fifth solution at a uniform speed.

[0106] Furthermore, the eighth solution is added into the seventh solution at a uniform speed.

[0107] Furthermore, the fifth solution is added into the sixth solution at a uniform speed.

[0108] Furthermore, the seventh solution is added into the eighth solution at a uniform speed.

[0109] Furthermore, the fifth solution and the sixth solution are added into the reaction container simultaneously.

[0110] Furthermore, the seventh solution and the eighth solution are added into the reaction container simultaneously.

[0111] Furthermore, the preparation method further comprises: after the reaction of the second mixed reaction system is completed, aging, washing and drying the obtained product to obtain the inorganic acid-intercalated hydrotalcite.

[0112] Furthermore, the aging temperature is 20-200°C and the time is 3-72h.

[0113] Furthermore, the drying temperature is 20-200°C.

[0114] Furthermore, the molar ratio of the trivalent metal element in the trivalent metal source to the alkali metal salt of naphthalene disulfonic acid and / or its derivatives is 1:1-1:4.

[0115] Furthermore, the co-precipitation method for preparing the inorganic acid intercalated hydrotalcite includes:

[0116] (1) Solution preparation

[0117] Weigh a certain amount of substance as n M and n A divalent and trivalent metal inorganic salts to ensure that the total amount of divalent metal elements to trivalent metal elements ratio is a specified value (n M :n A =2.0~3.0), add water to prepare a mixed solution A with a certain concentration of trivalent metal ions (0~0.8mol / L). Weigh a certain amount of alkali so that the amount of substance is 2(n M +n A )*(1±0.1), and prepare solution B with water. The concentration of effective hydroxide ions in solution B is (0.1~4.0mol / L).

[0118] (2) Reaction, aging, filtration and drying

[0119] The entire reaction can be carried out with stirring or ultrasound under nitrogen protection or without protection (a portion of the LDHs may be converted into carbonate intercalated LDHs when nitrogen protection is not added). The reaction can be added in any of the following three ways: (a) placing A in a reaction vessel, controlling the reaction temperature to a specified temperature (20-90°C), and then adding B to the A solution at a certain speed; (b) placing B in a reaction vessel, controlling the reaction temperature to a specified temperature (20-90°C), and then adding A to the B solution at a certain speed; (c) preheating the reaction vessel and keeping it warm to a specified temperature (20-90°C), and then adding the A and B solutions to the reaction vessel at a proportional speed to ensure that the addition is started and completed at the same time. After adding the materials, continue to keep the temperature in the reactor and stir for a certain period of time (0.5 to 3 hours), then transfer to an aging container (when the aging temperature is higher than the boiling point of water, a pressure-resistant and temperature-resistant container must be used), and after aging for a certain period of time (3 to 72 hours) at a certain temperature (20 to 200 degrees Celsius), filter and wash with water until the filtrate is neutral, and then use a certain amount of water (0.1 to 2 times the volume of the reaction liquid) to excessively wash the solid to further wash away soluble impurities. The filter cake is dried to constant weight in a vacuum or nitrogen atmosphere at a certain temperature (normal temperature to 200°C), or air drying can be selected, the disadvantage of which is that a small part of the LDHs may be converted into carbonate-intercalated hydrotalcite.

[0120] Furthermore, the preparation method specifically comprises: mixing the inorganic acid group intercalated hydrotalcite with a solution of an alkali metal salt of naphthalene disulfonic acid and / or its derivatives and reacting them at 20-90° C. for 0.5-3 h to obtain naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite.

[0121] Further, the alkali metal salt of naphthalene disulfonic acid and / or its derivatives includes any one or more combinations of sodium salt of naphthalene disulfonic acid and / or its derivatives and potassium salt of naphthalene disulfonic acid and / or its derivatives, but is not limited thereto.

[0122] Furthermore, the naphthalene disulfonic acid and / or its derivatives in the alkali metal salt of naphthalene disulfonic acid and / or its derivatives include 1,3-naphthalene disulfonic acid, 1,5-naphthalene disulfonic acid, 1,6-naphthalene disulfonic acid, 2,6-naphthalene disulfonic acid, 2,7-naphthalene disulfonic acid, 6-amino-1,3-naphthalene disulfonic acid, 5,6-diamino-1,3-naphthalene disulfonic acid, 7-amino-1,3-naphthalene disulfonic acid, 7-hydroxy-1,3-naphthalene disulfonic acid, 3-amino-1,5-naphthalene disulfonic acid, 8-amino-1,5 -naphthalene disulfonic acid, 3,6-dihydroxy-2,7-naphthalene disulfonic acid, 3-amino-2,7-naphthalene disulfonic acid, 3-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 4-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 1-hydroxy-3,6-naphthalene disulfonic acid, 2-hydroxy-3,6-naphthalene disulfonic acid, 1,8-dihydroxy-3,6-naphthalene disulfonic acid, 2-amino-4,8-naphthalene disulfonic acid, and any one or more combinations of 1-amino-3,8-naphthalene disulfonic acid, and are not limited thereto.

[0123] The naphthalene disulfonic acid and its derivatives in the present invention are important organic synthesis raw materials. The carbon atoms in the plane of the molecular ions are mutually conjugated, and through structural design and optimization, good ultraviolet or visible light absorption performance can be obtained. The naphthalene ring can also undergo π-π stacking with the organic polymer containing an aromatic ring, so that the naphthalene disulfonic acid and its derivative acid group intercalated hydrotalcite-like seasoning can slightly enhance the stretching of the organic polymer. Under alkaline conditions, two sulfonic acid groups can lose protons to form negative ions, thereby being inserted into the hydrotalcite-like to generate the acid group intercalated hydrotalcite-like of naphthalene disulfonic acid and its derivatives. The aromatic conjugated structure of naphthalene disulfonic acid and its derivatives also makes it easy to form carbon during thermal decomposition. This means that when it is inserted into hydrotalcite-like substances to prepare LDHs flame retardants, it can also promote carbon formation during the combustion of organic polymers, thereby improving the flame retardancy of organic polymers. At the same time, after naphthalene disulfonic acid and its derivatives are inserted into hydrotalcite-like substances as organic anions, they can increase the lipophilicity of the hydrotalcite-like substance surface, thereby improving the compatibility of LDHs with organic polymers and maintaining the mechanical properties of organic polymers after addition.

[0124] Furthermore, the preparation method further comprises: after the reaction of the inorganic acid group intercalated hydrotalcite and the alkali metal salt of naphthalene disulfonic acid and / or its derivatives is completed, aging, washing and drying the obtained product to obtain the naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite.

[0125] Furthermore, the aging temperature is 20-200°C and the time is 3-72h.

[0126] Furthermore, the drying temperature is 20-200°C.

[0127] In some preferred embodiments, the preparation method specifically includes (calcination reduction method):

[0128] reacting a second mixed reaction system comprising a divalent metal inorganic salt, a trivalent metal source, and an alkaline substance to obtain an inorganic acid root intercalated hydrotalcite;

[0129] calcining the inorganic acid-intercalated hydrotalcite to obtain a mixed oxide;

[0130] And, the mixed oxide is reacted with an alkali metal salt of naphthalene disulfonic acid and / or its derivatives to prepare a naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite.

[0131] Furthermore, the divalent metal element in the divalent metal inorganic salt includes any one or more combinations of magnesium, copper, calcium, zinc, and manganese, but is not limited thereto.

[0132] Furthermore, the divalent metal inorganic salt includes any one or more combinations of chlorides, nitrates, and sulfates, but is not limited thereto.

[0133] Furthermore, the trivalent metal source includes any one or more combinations of trivalent metal inorganic salts, aluminum hydroxide, sodium aluminate, and sodium metaaluminate, but is not limited thereto.

[0134] Furthermore, the trivalent metal inorganic salt includes aluminum salt and / or iron salt, but is not limited thereto.

[0135] Further, the alkaline substance includes alkali metal hydroxide, but is not limited thereto.

[0136] Furthermore, the molar amount of the alkaline substance in the second mixed reaction system is 0.9×2(n M +n A )~1.1×2(n M +n A ), where n M is the molar amount of the divalent metal element in the divalent metal inorganic salt, n A is the molar amount of the trivalent metal element in the trivalent metal source.

[0137] Furthermore, the molar ratio of the divalent metal element to the trivalent metal element in the second mixed reaction system is 2:1-3:1.

[0138] Furthermore, the preparation method specifically comprises:

[0139] dissolving a divalent metal inorganic salt and a trivalent metal source in water to obtain a ninth solution;

[0140] dissolving the alkaline substance in water to obtain a tenth solution;

[0141] And, the ninth solution and the tenth solution are mixed and reacted at 20-90° C. for 0.5-3 h to obtain an inorganic acid intercalated hydrotalcite.

[0142] Furthermore, the ion concentration of the trivalent metal element in the ninth solution is 0.1-0.8 mol / L.

[0143] Furthermore, the ion concentration of the divalent metal element in the ninth solution is 0.1-1.6 mol / L.

[0144] Furthermore, the concentration of effective hydroxide ions in the tenth solution is 0.1-4.0 mol / L.

[0145] Furthermore, the preparation method specifically comprises:

[0146] dissolving a divalent metal inorganic salt in water to obtain an eleventh solution;

[0147] dissolving a trivalent metal source and an alkaline substance in water to obtain a twelfth solution;

[0148] And, the eleventh solution and the twelfth solution are mixed and reacted at 20-90° C. for 0.5-3 h to obtain an inorganic acid intercalated hydrotalcite.

[0149] Furthermore, the ion concentration of the divalent metal element in the eleventh solution is 0.1-1.6 mol / L.

[0150] Furthermore, the ion concentration of the trivalent metal element in the twelfth solution is 0.1-0.8 mol / L.

[0151] Furthermore, the concentration of effective hydroxide ions in the twelfth solution is 0.1-4.0 mol / L.

[0152] Furthermore, the tenth solution is added into the ninth solution at a uniform speed.

[0153] Furthermore, the twelfth solution is added into the eleventh solution at a uniform speed.

[0154] Furthermore, the ninth solution is added into the tenth solution at a uniform speed.

[0155] Furthermore, the eleventh solution is added into the twelfth solution at a uniform speed.

[0156] Furthermore, the ninth solution and the tenth solution are added into the reaction container simultaneously.

[0157] Furthermore, the eleventh solution and the twelfth solution are added into the reaction container simultaneously.

[0158] Furthermore, the preparation method further comprises: after the reaction of the second mixed reaction system is completed, aging, washing and drying the obtained product to obtain the inorganic acid-intercalated hydrotalcite.

[0159] Furthermore, the aging temperature is 20-200°C and the time is 3-72h.

[0160] Furthermore, the drying temperature is 20-200°C.

[0161] Furthermore, the calcination treatment is carried out at a temperature of 400-560° C. and for a time of 0.5-10 h.

[0162] Furthermore, the molar ratio of the trivalent metal element in the trivalent metal source to the alkali metal salt of naphthalene disulfonic acid and / or its derivatives is 1:1-1:4.

[0163] Furthermore, the preparation method specifically comprises: mixing the mixed oxide with a solution of an alkali metal salt of naphthalene disulfonic acid and / or its derivatives and reacting at 20-90° C. for 0.5-3 h to obtain naphthalene disulfonic acid and / or its derivatives acid group intercalated hydrotalcite.

[0164] Furthermore, the molar ratio of the trivalent metal element in the mixed oxide to the alkali metal salt of naphthalene disulfonic acid and / or its derivatives is 1:1-1:6.

[0165] Further, the alkali metal salt of naphthalene disulfonic acid and / or its derivatives includes any one or more combinations of sodium salt of naphthalene disulfonic acid and / or its derivatives and potassium salt of naphthalene disulfonic acid and / or its derivatives, but is not limited thereto.

[0166] Furthermore, the naphthalene disulfonic acid and / or its derivatives in the alkali metal salt of naphthalene disulfonic acid and / or its derivatives include 1,3-naphthalene disulfonic acid, 1,5-naphthalene disulfonic acid, 1,6-naphthalene disulfonic acid, 2,6-naphthalene disulfonic acid, 2,7-naphthalene disulfonic acid, 6-amino-1,3-naphthalene disulfonic acid, 5,6-diamino-1,3-naphthalene disulfonic acid, 7-amino-1,3-naphthalene disulfonic acid, 7-hydroxy-1,3-naphthalene disulfonic acid, 3-amino-1,5-naphthalene disulfonic acid, 8-amino-1,5 -naphthalene disulfonic acid, 3,6-dihydroxy-2,7-naphthalene disulfonic acid, 3-amino-2,7-naphthalene disulfonic acid, 3-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 4-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 1-hydroxy-3,6-naphthalene disulfonic acid, 2-hydroxy-3,6-naphthalene disulfonic acid, 1,8-dihydroxy-3,6-naphthalene disulfonic acid, 2-amino-4,8-naphthalene disulfonic acid, and any one or more combinations of 1-amino-3,8-naphthalene disulfonic acid, and are not limited thereto.

[0167] Furthermore, the preparation method further comprises: after the reaction of the mixed oxide and the alkali metal salt of naphthalene disulfonic acid and / or its derivatives is completed, aging, washing and drying the obtained product to obtain naphthalene disulfonic acid and / or its derivatives acid group intercalated hydrotalcite.

[0168] Furthermore, the aging temperature is 20-200°C and the time is 3-72h.

[0169] Furthermore, the drying temperature is 20-200°C.

[0170] Another aspect of the embodiments of the present invention further provides the use of the aforementioned naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite in flame retardancy of organic polymers.

[0171] In summary, the present invention provides naphthalene disulfonic acid and / or its derivatives acid group intercalated hydrotalcite and a synthesis method thereof. This material is naphthalene disulfonic acid and / or its derivatives acid group intercalated hydrotalcite, which is prepared by using divalent or trivalent inorganic salts as metal ion sources, naphthalene disulfonic acid and its derivatives or their salts as anion sources, and sodium hydroxide or potassium hydroxide as an alkali source to prepare a type of hydrotalcite material that can simultaneously improve the flame retardancy, UV resistance and mechanical retention of organic polymers.

[0172] The present invention discloses a potential high-efficiency organic acid root intercalated magnesium-based hydrotalcite flame retardant filler, which can significantly improve the flame retardancy of organic polymers through the carbonization of organic acid roots themselves, catalytic carbonization of organic polymers, physical barrier of hydroxides and absorption of heat; can effectively improve the lipophilicity of hydrotalcite-like materials through interlayer organic anions, thereby improving its compatibility with organic polymers and achieving mechanical enhancement; and can achieve the improvement of the ultraviolet absorption performance of NSLDHs through the conjugation of naphthalene rings. The NSLDHs synthesized by the method disclosed in the present invention can solve the problem that traditional hydrotalcites cannot simultaneously achieve the enhancement of mechanical properties of organic polymers and the improvement of flame retardancy and ultraviolet light absorption. It provides an effective way for the high-value development of Qinghai magnesium chloride resources, which can effectively achieve the maintenance of mechanical properties of organic polymers and the improvement of flame retardancy and ultraviolet absorption, and is a potential large-scale application of organic acid root intercalated magnesium-based hydrotalcite.

[0173] The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments and drawings. This embodiment is implemented on the premise of the technical solution of the invention, and a detailed implementation method and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0174] Unless otherwise specified, the experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

[0175] Example 1

[0176] Preparation of 1,5-Naphthalenedisulfonate Intercalated Magnesium-Aluminum LDHs

[0177] Weigh 2.03g of magnesium chloride hexahydrate and 1.21g of aluminum chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 2.50g of sodium 1,5-naphthalene disulfonate and 1.2g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, put it in an 80℃ oven for aging for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 1,5-naphthalene disulfonate intercalated magnesium aluminum LDHs with a magnesium aluminum ratio of 2:1 was obtained. Its XRD pattern is shown in the figure below. Figure 1 shown.

[0178] Example 2

[0179] Preparation of 1,6-Naphthalenedisulfonate Intercalated Magnesium-Aluminum LDHs

[0180] Weigh 2.03g of magnesium chloride hexahydrate and 1.21g of aluminum chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 2.50g of 1,6-naphthalene disulfonic acid and 1.83g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, put it in an 80℃ oven for aging for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 1,6-naphthalene disulfonate intercalated magnesium aluminum LDHs with a magnesium aluminum ratio of 2:1 was obtained. Its XRD pattern is shown in the figure below. Figure 2 shown.

[0181] Example 3

[0182] Preparation of 2,6-Naphthalene Disulfonate Intercalated Magnesium-Aluminum LDHs

[0183] Weigh 2.03g of magnesium chloride hexahydrate and 1.21g of aluminum chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 2.50g of sodium 2,6-naphthalene disulfonate and 1.2g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, put it in an 80℃ oven for aging for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 2,6-naphthalene disulfonate intercalated magnesium aluminum LDHs with a magnesium aluminum ratio of 2:1 was obtained. Its XRD pattern is shown in the figure below. Figure 3 shown.

[0184] Example 4

[0185] Preparation of 2,6-naphthalene disulfonate intercalated calcium aluminum LDHs

[0186] Weigh 2.19g of calcium chloride hexahydrate and 1.21g of aluminum chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 2.50g of sodium 2,6-naphthalene disulfonate and 1.2g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, put it in an 80℃ oven for aging for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 2,6-naphthalene disulfonate intercalated calcium aluminum LDHs with a calcium-aluminum ratio of 2:1 was obtained. Its XRD pattern is shown in the figure below. Figure 4 shown.

[0187] Example 5

[0188] Preparation of 2,6-Naphthalenedisulfonate Intercalated Zn-Al LDHs

[0189] Weigh 1.36g zinc chloride hexahydrate and 1.21g aluminum chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 2.50g of sodium 2,6-naphthalene disulfonate and 1.2g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, put it in an 80℃ oven for aging for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 2,6-naphthalene disulfonic acid intercalated zinc-aluminum LDHs with a zinc-aluminum ratio of 2:1 were obtained. Its XRD pattern is shown in the figure below. Figure 5 shown.

[0190] Example 6

[0191] Preparation of 2,6-Naphthalene Disulfonate Intercalated Magnesium-Aluminum LDHs

[0192] Weigh 3.05g of magnesium chloride hexahydrate and 1.21g of aluminum chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 2.50g of sodium 2,6-naphthalene disulfonate and 1.2g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, put it in an 80℃ oven for aging for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 2,6-naphthalene disulfonate intercalated magnesium aluminum LDHs with a magnesium aluminum ratio of 3:1 was obtained. Its XRD pattern is shown in the figure below. Figure 6 shown.

[0193] Example 7

[0194] Preparation of 2,6-naphthalene disulfonate intercalated magnesium iron LDHs

[0195] Weigh 2.03g of magnesium chloride hexahydrate and 1.35g of ferric chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 2.50g of sodium 2,6-naphthalene disulfonate and 1.2g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, put it in an 80℃ oven for aging for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 2,6-naphthalene disulfonate intercalated magnesium-iron LDHs with a magnesium-iron ratio of 2:1 were obtained. Its XRD pattern is shown in the figure below. Figure 7 shown.

[0196] Example 8

[0197] Preparation of 2,6-Naphthalene Disulfonate Intercalated Magnesium-Aluminum LDHs

[0198] Weigh 2.03g of magnesium chloride hexahydrate and 1.21g of aluminum chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 1.67g of sodium 2,6-naphthalene disulfonate and 1.2g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, put it in an 80℃ oven for aging for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 2,6-naphthalene disulfonate intercalated magnesium aluminum LDHs with a magnesium aluminum ratio of 2:1 was obtained. Its XRD pattern is shown in the figure below. Figure 8 shown.

[0199] Example 9

[0200] Preparation of 2,6-Naphthalene Disulfonate Intercalated Magnesium-Aluminum LDHs

[0201] Weigh 2.03g of magnesium chloride hexahydrate and 1.21g of aluminum chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 3.33g of sodium 2,6-naphthalene disulfonate and 1.2g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, put it in an 80℃ oven for aging for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 2,6-naphthalene disulfonate intercalated magnesium aluminum LDHs with a magnesium aluminum ratio of 2:1 was obtained. Its XRD pattern is shown in the figure below. Fig. 9 shown.

[0202] Example 10

[0203] Preparation of 2,6-Naphthalene Disulfonate Intercalated Magnesium-Aluminum LDHs

[0204] Weigh 2.03g of magnesium chloride hexahydrate and 1.21g of aluminum chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 1.67g of sodium 2,6-naphthalene disulfonate and 1.2g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, age it at room temperature for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 2,6-naphthalene disulfonate intercalated magnesium aluminum LDHs with a magnesium aluminum ratio of 2:1 was obtained. Its XRD pattern is shown in the figure below. Fig.10 shown.

[0205] Embodiment 11

[0206] Preparation of 3-amino-1,5-naphthalene disulfonate intercalated magnesium aluminum LDHs

[0207] Weigh 2.03g of magnesium chloride hexahydrate and 1.21g of aluminum chloride hexahydrate, add 50mL of distilled water that has been boiled to remove carbon dioxide to prepare solution A, transfer it into a 500mL round-bottom three-necked flask, pass gas protection, and put the flask into a 60℃ constant temperature water bath for 30min. Weigh 1.75g ​​of sodium 3-amino-1,5-naphthalene disulfonate and 1.2g of sodium hydroxide, add 50mL of distilled water to prepare solution B. Slowly add solution B to solution A at a rate of 2mL / min, and pass gas for protection. Continue stirring for 1h after adding. The reaction is carried out in a 60℃ water bath. After the reaction, transfer it to a conical flask, age it at room temperature for 24 hours, and filter it after taking it out. The aged suspension was washed with secondary water for several times and filtered until the pH of the filtrate at the funnel outlet was 7, and then 150 mL of secondary water was added for further washing for several times until the filter cake cracked. The filter cake was placed in a 60°C vacuum drying oven and fully dried. After being taken out and ground, it was sieved with a 200-mesh sieve. Thus, 3-amino-1,5-naphthalene disulfonic acid intercalated magnesium aluminum LDHs with a magnesium aluminum ratio of 2:1 was obtained. Its XRD pattern is shown in the figure below. Fig.11 shown.

[0208] Comparative Example

[0209] In order to demonstrate that the naphthalene disulfonate intercalated hydrotalcite synthesized in the present invention can be used for flame retardant of organic polymers, the present invention selects epoxy resin (E44) cured with diaminodiphenylmethane (DDM) as the organic polymer substrate to carry out corresponding comparative studies, and at the same time, selects analytically pure aluminum hydroxide as a general flame retardant for comparison.

[0210] The preparation process of epoxy resin and epoxy resin composite material is as follows: preheat epoxy resin in a 90 degree Celsius oil bath. If a composite material is prepared, add flame retardant to preheated epoxy resin in a certain mass ratio and stir evenly. Then add curing agent DDM to preheated epoxy resin in a certain mass ratio at a certain rate, remove bubbles by vacuum method, pour into mold for curing, and use limiting oxygen index instrument to measure limiting oxygen index of corresponding materials. In this comparative example, the proportion of corresponding species in epoxy resin composite material is: epoxy resin: flame retardant: curing agent is 73.8wt.%: 10wt.%: 16.2wt.%, while the proportion of epoxy resin: curing agent in epoxy resin is 82wt.%: 18wt.%. The limiting oxygen index test results are as follows.

[0211] The limiting oxygen index of pure epoxy resin substrate is 25.1%;

[0212] The limiting oxygen index of the epoxy resin composite material with aluminum hydroxide added is 26.5%;

[0213] The limiting oxygen index of the epoxy resin composite material with 1,5-naphthalene disulfonate intercalated Mg-Al LDHs is 29.2%;

[0214] The limiting oxygen index of the epoxy resin composite material with 1,6-naphthalene disulfonate intercalated Mg-Al LDHs is 28.9%;

[0215] The limiting oxygen index of the epoxy resin composite material with 2,6-naphthalene disulfonate intercalated Mg-Al LDHs is 29.1%;

[0216] The limiting oxygen index of the epoxy resin composite material with 3-amino-1,5-naphthalene disulfonate intercalated Mg-Al LDHs is 28.5%;

[0217] It can be seen from the flame retardant test results of the comparative examples that the naphthalene disulfonate intercalated LDHs described in the present invention have good limiting oxygen index test performance.

[0218] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0219] It should be understood that the technical solution of the present invention is not limited to the above-mentioned specific implementation cases. Any technical deformation made according to the technical solution of the present invention without departing from the scope of protection of the purpose of the present invention and the claims shall fall within the protection scope of the present invention.

Claims

1. A naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite, characterized in that: The chemical formula of the naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite is: Among them, 0<x<1, A 2- is naphthalene disulfonic acid radical and / or naphthalene disulfonic acid derivative radical, M 2+ Any one or more combinations selected from magnesium, zinc, calcium, and nickel, M 3+ Selected from aluminum and / or iron.

2. The naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite according to claim 1, characterized in that: The naphthalene disulfonate and / or naphthalene disulfonic acid derivative acid radicals include 1,3-naphthalene disulfonate, 1,5-naphthalene disulfonate, 1,6-naphthalene disulfonate, 2,6-naphthalene disulfonate, 2,7-naphthalene disulfonate, 6-amino-1,3-naphthalene disulfonate, 5,6-diamino-1,3-naphthalene disulfonate, 7-amino-1,3-naphthalene disulfonate, 7-hydroxy-1,3-naphthalene disulfonate, 3-amino-1,5-naphthalene disulfonate, 8-amino-1,5-naphthalene disulfonate. , 3,6-dihydroxy-2,7-naphthalene disulfonate, 3-amino-2,7-naphthalene disulfonate, 3-amino-5-hydroxy-2,7-naphthalene disulfonate, 4-amino-5-hydroxy-2,7-naphthalene disulfonate, 1-hydroxy-3,6-naphthalene disulfonate, 2-hydroxy-3,6-naphthalene disulfonate, 1,8-dihydroxy-3,6-naphthalene disulfonate, 2-amino-4,8-naphthalene disulfonate, and any one or more combinations of 1-amino-3,8-naphthalene disulfonate.

3. The method for preparing the naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite according to claim 1 or 2, characterized in that: include: At least one of the following methods is adopted: coprecipitation method, ion exchange method and roasting reduction method to prepare naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite.

4. The preparation method according to claim 3, characterized in that: Specifically include: A first mixed reaction system comprising naphthalene disulfonic acid and / or its derivatives or alkali metal salts of naphthalene disulfonic acid and / or its derivatives, divalent metal inorganic salts, trivalent metal sources and alkaline substances is reacted to obtain naphthalene disulfonic acid and / or its derivatives acid group intercalated hydrotalcite.

5. The preparation method according to claim 4, characterized in that: The naphthalene disulfonic acid and / or its derivatives include 1,3-naphthalene disulfonic acid, 1,5-naphthalene disulfonic acid, 1,6-naphthalene disulfonic acid, 2,6-naphthalene disulfonic acid, 2,7-naphthalene disulfonic acid, 6-amino-1,3-naphthalene disulfonic acid, 5,6-diamino-1,3-naphthalene disulfonic acid, 7-amino-1,3-naphthalene disulfonic acid, 7-hydroxy-1,3-naphthalene disulfonic acid, 3-amino-1,5-naphthalene disulfonic acid, 8-amino-1,5-naphthalene disulfonic acid, 3,6 -dihydroxy-2,7-naphthalene disulfonic acid, 3-amino-2,7-naphthalene disulfonic acid, 3-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 4-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 1-hydroxy-3,6-naphthalene disulfonic acid, 2-hydroxy-3,6-naphthalene disulfonic acid, 1,8-dihydroxy-3,6-naphthalene disulfonic acid, 2-amino-4,8-naphthalene disulfonic acid, 1-amino-3,8-naphthalene disulfonic acid, any one or more combinations thereof; And / or, the naphthalene disulfonic acid and / or its derivatives include compounds and / or salts thereof in which two hydrogen atoms on the naphthalene ring are replaced by sulfonic acid groups; And / or, the alkali metal salt of naphthalene disulfonic acid and / or its derivatives includes any one or more combinations of sodium salt of naphthalene disulfonic acid and / or its derivatives and potassium salt of naphthalene disulfonic acid and / or its derivatives; And / or, the divalent metal element in the divalent metal inorganic salt includes any one or more combinations of magnesium, copper, calcium, zinc, and manganese; and / or, the divalent metal inorganic salt includes any one or more combinations of chlorides, nitrates, and sulfates; And / or, the trivalent metal source includes any one or more combinations of trivalent metal inorganic salts, aluminum hydroxide, sodium aluminate, and sodium metaaluminate; preferably, the trivalent metal inorganic salt includes aluminum salt and / or iron salt; and / or, the alkaline substance comprises an alkali metal hydroxide; And / or, the molar amount of the alkaline substance in the first mixed reaction system is 0.9×(2(n M +n A )+n O )~1.1×(2(nM+n A )+n O ), where n M is the molar amount of the divalent metal element in the divalent metal inorganic salt, n A is the molar amount of the trivalent metal element in the trivalent metal source, n O is the molar amount of naphthalene disulfonic acid and / or its derivatives or alkali metal salts of naphthalene disulfonic acid and / or its derivatives; and / or, the molar ratio of the divalent metal element to the trivalent metal element in the first mixed reaction system is 2:1-3:1; and / or, the molar ratio of the trivalent metal element to naphthalene disulfonic acid and / or its derivatives or the alkali metal salt of naphthalene disulfonic acid and / or its derivatives in the first mixed reaction system is 1:1-1:4; And / or, the preparation method specifically comprises: dissolving a divalent metal inorganic salt and a trivalent metal source in water to obtain a first solution; dissolving naphthalene disulfonic acid and / or its derivatives or alkali metal salts of naphthalene disulfonic acid and / or its derivatives and a base in water to obtain a second solution; And, the first solution and the second solution are mixed and reacted at 20-90° C. for 0.5-3h to obtain naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite; preferably, the ion concentration of the divalent metal element in the first solution is 0.1-1.6 mol / L; preferably, the ion concentration of the trivalent metal element in the first solution is 0.1-0.8 mol / L; preferably, the concentration of effective hydroxide ions in the second solution is 0.1-4.0 mol / L; And / or, the preparation method specifically comprises: dissolving a divalent metal inorganic salt, naphthalene disulfonic acid and / or its derivatives, or an alkali metal salt of naphthalene disulfonic acid and / or its derivatives in water to obtain a third solution; dissolving a trivalent metal source and a base in water to obtain a fourth solution; And, the third solution and the fourth solution are mixed and reacted at 20-90° C. for 0.5-3 h to obtain naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite; preferably, the ion concentration of the divalent metal element in the third solution is 0.1-1.6 mol / L; preferably, the ion concentration of the trivalent metal element in the fourth solution is 0.1-0.8 mol / L; preferably, the concentration of effective hydroxide ions in the fourth solution is 0.1-4.0 mol / L; And / or, the preparation method further comprises: after the reaction of the first mixed reaction system is completed, aging, washing and drying the obtained product; preferably, the aging temperature is 20-200°C and the time is 3-72h; preferably, the drying temperature is 20-200°C.

6. The preparation method according to claim 3, characterized in that: Specifically include: reacting a second mixed reaction system comprising a divalent metal inorganic salt, a trivalent metal source, and an alkaline substance to obtain an inorganic acid root intercalated hydrotalcite; And, the inorganic acid group intercalated hydrotalcite is subjected to ion exchange reaction with an alkali metal salt of naphthalene disulfonic acid and / or its derivatives to obtain the naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite.

7. The preparation method according to claim 6, characterized in that: The divalent metal element in the divalent metal inorganic salt includes any one or more combinations of magnesium, copper, calcium, zinc, and manganese; and / or the divalent metal inorganic salt includes any one or more combinations of chloride, nitrate, and sulfate; And / or, the trivalent metal source includes any one or more combinations of trivalent metal inorganic salts, aluminum hydroxide, sodium aluminate, and sodium metaaluminate; preferably, the trivalent metal inorganic salt includes aluminum salt and / or iron salt; and / or, the alkaline substance comprises an alkali metal hydroxide; And / or, the molar amount of the alkaline substance in the second mixed reaction system is 0.9×2(n M +n A )~1.1×2(n M +n A ), where n M is the molar amount of the divalent metal element in the divalent metal inorganic salt, n A is the molar amount of the trivalent metal element in the trivalent metal source; and / or, the molar ratio of the divalent metal element to the trivalent metal element in the second mixed reaction system is 2:1-3:1; And / or, the preparation method specifically comprises: dissolving a divalent metal inorganic salt and a trivalent metal source in water to obtain a fifth solution; dissolving an alkaline substance in water to obtain a sixth solution; And, the fifth solution and the sixth solution are mixed and reacted at 20-90° C. for 0.5-3 h to obtain an inorganic acid root intercalated hydrotalcite; preferably, the ion concentration of the trivalent metal element in the fifth solution is 0.1-0.8 mol / L; preferably, the ion concentration of the divalent metal element in the fifth solution is 0.1-1.6 mol / L; preferably, the concentration of effective hydroxide ions in the sixth solution is 0.1-4.0 mol / L; And / or, the preparation method specifically comprises: dissolving a divalent metal inorganic salt in water to obtain a seventh solution; dissolving a trivalent metal source and an alkaline substance in water to obtain an eighth solution; And, the seventh solution and the eighth solution are mixed and reacted at 20-90° C. for 0.5-3h to obtain an inorganic acid root intercalated hydrotalcite; preferably, the ion concentration of the divalent metal element in the seventh solution is 0.1-1.6 mol / L; preferably, the ion concentration of the trivalent metal element in the eighth solution is 0.1-0.8 mol / L; preferably, the concentration of effective hydroxide ions in the eighth solution is 0.1-4.0 mol / L; And / or, the preparation method further comprises: after the reaction of the second mixed reaction system is completed, aging, washing and drying the obtained product to obtain an inorganic acid root intercalated hydrotalcite; preferably, the aging temperature is 20-200°C and the time is 3-72h; preferably, the drying temperature is 20-200°C; and / or, the molar ratio of the trivalent metal element in the trivalent metal source to the alkali metal salt of naphthalene disulfonic acid and / or its derivative is 1:1-1:4; And / or, the preparation method specifically comprises: mixing the inorganic acid group intercalated hydrotalcite with a solution of an alkali metal salt of naphthalene disulfonic acid and / or its derivatives and reacting at 20-90° C. for 0.5-3 h to obtain the naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite; And / or, the alkali metal salt of naphthalene disulfonic acid and / or its derivatives includes any one or more combinations of sodium salt of naphthalene disulfonic acid and / or its derivatives, potassium salt of naphthalene disulfonic acid and / or its derivatives; preferably, the naphthalene disulfonic acid and / or its derivatives in the alkali metal salt of naphthalene disulfonic acid and / or its derivatives include 1,3-naphthalene disulfonic acid, 1,5-naphthalene disulfonic acid, 1,6-naphthalene disulfonic acid, 2,6-naphthalene disulfonic acid, 2,7-naphthalene disulfonic acid, 6-amino-1,3-naphthalene disulfonic acid, 5,6-diamino-1,3-naphthalene disulfonic acid, 7-amino-1,3-naphthalene disulfonic acid, 7 -hydroxy-1,3-naphthalene disulfonic acid, 3-amino-1,5-naphthalene disulfonic acid, 8-amino-1,5-naphthalene disulfonic acid, 3,6-dihydroxy-2,7-naphthalene disulfonic acid, 3-amino-2,7-naphthalene disulfonic acid, 3-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 4-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 1-hydroxy-3,6-naphthalene disulfonic acid, 2-hydroxy-3,6-naphthalene disulfonic acid, 1,8-dihydroxy-3,6-naphthalene disulfonic acid, 2-amino-4,8-naphthalene disulfonic acid, 1-amino-3,8-naphthalene disulfonic acid any one or more combinations; And / or, the preparation method further comprises: after the reaction of the inorganic acid group intercalated hydrotalcite with the alkali metal salt of naphthalene disulfonic acid and / or its derivatives is completed, aging, washing and drying the obtained product to obtain naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite; preferably, the aging temperature is 20-200°C and the time is 3-72h; preferably, the drying temperature is 20-200°C.

8. The preparation method according to claim 3, characterized in that: Specifically include: reacting a second mixed reaction system comprising a divalent metal inorganic salt, a trivalent metal source, and an alkaline substance to obtain an inorganic acid root intercalated hydrotalcite; calcining the inorganic acid-intercalated hydrotalcite to obtain a mixed oxide; And, the mixed oxide is reacted with an alkali metal salt solution of naphthalene disulfonic acid and / or its derivatives to prepare naphthalene disulfonic acid and / or its derivatives acid group intercalated hydrotalcite.

9. The preparation method according to claim 8, characterized in that: The divalent metal element in the divalent metal inorganic salt includes any one or more combinations of magnesium, copper, calcium, zinc, and manganese; and / or the divalent metal inorganic salt includes any one or more combinations of chloride, nitrate, and sulfate; And / or, the trivalent metal source includes any one or more combinations of trivalent metal inorganic salts, aluminum hydroxide, sodium aluminate, and sodium metaaluminate; preferably, the trivalent metal inorganic salt includes aluminum salt and / or iron salt; and / or, the alkaline substance comprises an alkali metal hydroxide; And / or, the molar amount of the alkaline substance in the second mixed reaction system is 0.9×2(n M +n A )~1.1×2(n M +n A ), where n M is the molar amount of the divalent metal element in the divalent metal inorganic salt, n A is the molar amount of the trivalent metal element in the trivalent metal source; and / or, the molar ratio of the divalent metal element to the trivalent metal element in the second mixed reaction system is 2:1-3:1; And / or, the preparation method specifically comprises: dissolving a divalent metal inorganic salt and a trivalent metal source in water to obtain a ninth solution; dissolving the alkaline substance in water to obtain a tenth solution; And, the ninth solution and the tenth solution are mixed and reacted at 20-90° C. for 0.5-3h to obtain an inorganic acid root intercalated hydrotalcite; preferably, the ion concentration of the trivalent metal element in the ninth solution is 0.1-0.8 mol / L; preferably, the ion concentration of the divalent metal element in the ninth solution is 0.1-1.6 mol / L; preferably, the concentration of effective hydroxide ions in the tenth solution is 0.1-4.0 mol / L; And / or, the preparation method specifically comprises: dissolving a divalent metal inorganic salt in water to obtain an eleventh solution; dissolving a trivalent metal source and an alkaline substance in water to obtain a twelfth solution; And, the eleventh solution and the twelfth solution are mixed and reacted at 20-90° C. for 0.5-3h to obtain an inorganic acid root intercalated hydrotalcite; preferably, the ion concentration of the divalent metal element in the eleventh solution is 0.1-1.6 mol / L; preferably, the ion concentration of the trivalent metal element in the twelfth solution is 0.1-0.8 mol / L; preferably, the concentration of effective hydroxide ions in the twelfth solution is 0.1-4.0 mol / L; And / or, the preparation method further comprises: after the reaction of the second mixed reaction system is completed, aging, washing and drying the obtained product to obtain an inorganic acid root intercalated hydrotalcite; preferably, the aging temperature is 20-200°C and the time is 3-72h; preferably, the drying temperature is 20-200°C; And / or, the calcination temperature is 400-560°C and the time is 0.5-10h; and / or, the molar ratio of the trivalent metal element in the trivalent metal source to the alkali metal salt of naphthalene disulfonic acid and / or its derivative is 1:1-1:4; And / or, the preparation method specifically comprises: mixing the mixed oxide with a solution of an alkali metal salt of naphthalene disulfonic acid and / or its derivatives and reacting at 20-90° C. for 0.5-3 h to obtain a naphthalene disulfonic acid and / or its derivative acid group intercalated hydrotalcite; and / or, the molar ratio of the trivalent metal element in the mixed oxide to the alkali metal salt of naphthalene disulfonic acid and / or its derivative is 1:1-1:6; And / or, the alkali metal salt of naphthalene disulfonic acid and / or its derivatives includes any one or more combinations of sodium salt of naphthalene disulfonic acid and / or its derivatives, potassium salt of naphthalene disulfonic acid and / or its derivatives; preferably, the naphthalene disulfonic acid and / or its derivatives in the alkali metal salt of naphthalene disulfonic acid and / or its derivatives include 1,3-naphthalene disulfonic acid, 1,5-naphthalene disulfonic acid, 1,6-naphthalene disulfonic acid, 2,6-naphthalene disulfonic acid, 2,7-naphthalene disulfonic acid, 6-amino-1,3-naphthalene disulfonic acid, 5,6-diamino-1,3-naphthalene disulfonic acid, 7-amino-1,3-naphthalene disulfonic acid, 7 -hydroxy-1,3-naphthalene disulfonic acid, 3-amino-1,5-naphthalene disulfonic acid, 8-amino-1,5-naphthalene disulfonic acid, 3,6-dihydroxy-2,7-naphthalene disulfonic acid, 3-amino-2,7-naphthalene disulfonic acid, 3-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 4-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 1-hydroxy-3,6-naphthalene disulfonic acid, 2-hydroxy-3,6-naphthalene disulfonic acid, 1,8-dihydroxy-3,6-naphthalene disulfonic acid, 2-amino-4,8-naphthalene disulfonic acid, 1-amino-3,8-naphthalene disulfonic acid any one or more combinations; And / or, the preparation method further comprises: after the reaction of the mixed oxide and the alkali metal salt of naphthalene disulfonic acid and / or its derivatives is completed, aging, washing and drying the obtained product to obtain naphthalene disulfonic acid and / or its derivatives acid group intercalated hydrotalcite; preferably, the aging temperature is 20-200°C and the time is 3-72h; preferably, the drying temperature is 20-200°C.

10. Use of the naphthalenedisulfonic acid and / or its derivative acid group intercalated hydrotalcite as claimed in claim 1 or 2 in flame retardant of organic polymers.

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