KR100863282B1 - Synthetic method for metal hydroxide phosphate - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the preparation of phosphates of metal hydroxide compounds. Specifically, in synthesizing aluminum hydroxide phosphate, magnesium hydroxide phosphate and calcium hydroxide phosphate, phosphoric acid is reacted with a hydroxyl group of aluminum hydroxide, magnesium hydroxide and calcium hydroxide in a high temperature aqueous solution. The present invention relates to a method of forming a new crystalline product each having a metal hydroxide and a phosphoric acid property by forming with a phosphate of a metal hydroxide, and a method for producing a synergistic effect on the use of the metal hydroxide or phosphoric acid by the method of preparing the same. According to the present invention, a difference occurs in the crystal structure and physical properties of the metal hydroxide formed according to the reaction equivalent of the phosphoric acid in the reaction of the phosphate of the metal hydroxide, in particular, aluminum hydroxide and magnesium hydroxide and calcium hydroxide and phosphoric acid. The difference in structure means that various salt compounds are formed, and a method of forming a stabilized salt product formed according to various changes in the reaction molar ratio of the metal hydroxide and phosphate, and a technique related to the preparation method thereof.

       To this end, the present invention, by dispersing the crystalline powder of aluminum hydroxide, magnesium hydroxide, calcium hydroxide as water as a metal hydroxide in water to raise the temperature to high temperature and then to the solid-liquid mixture (phosphoric acid or orthophosphoric acid) or oligomeric phosphoric acid (pyrophosphoric acid) acid, tripolyphosphoric acid, tetrapolyphosphoric acid), or cyclic phosphoric acid (trimeaphosphoric acid, phosphoric anhydride), or polyphosphoric acid, or trimethyl phosphate or hexamethyl phosphoric triamide. By dropping, metal hydroxide phosphate, i.e., aluminum hydroxide phosphate, magnesium hydroxide phosphate, and calcium hydroxide phosphate, respectively, is synthesized, thereby reducing the function of the acid to form salts, that is, physicochemically stable crystalline particles. Characterized by .

      Metal hydroxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, phosphoric acid, polymer type phosphoric acid, phosphate, aluminum hydroxide phosphate, magnesium hydroxide phosphate, calcium hydroxide phosphate

Description

Synthetic method for metal hydroxide phosphate

Generalized process diagram for the synthesis of phosphate of metal hydroxide compounds and the physical properties of the reaction of metal hydroxide compounds of the present invention, specifically, for example, aluminum hydroxide and magnesium hydroxide, and phosphoric acid reacting thereto, specifically phosphoric acid Comparison of chemical changes measured by XRD, SDT and SEM

The present invention is one method of extending the function of a metal hydroxide compound, for example, to enhance the effect of the flame retardant function of a metal hydroxide compound or to induce a sensitive change in thermal change or, conversely, to insensitive to thermal change. A method of forming a metal phosphate by reacting a metal compound with an inorganic and organic phosphoric acid, and more particularly, the crystallinity of the aluminum hydroxide, magnesium hydroxide and calcium hydroxide to form phosphates of aluminum hydroxide, magnesium hydroxide and calcium hydroxide. The powder particles are dispersed in water to form a slurry, and then phosphoric acid or high molecular phosphoric acid is added dropwise at various reaction equivalent ratios according to the hydroxyl equivalent of the metal hydroxide, and the metal hydroxide phosphate, that is, aluminum hydroxide phosphate, magnesium hydroxide phosphate and calcium hydroxide phosphate The present invention relates to a method for forming a metal hydroxide phosphate compound, each of which is synthesized into a physicochemically stable form. The present invention also relates to a method in which the acid function of phosphoric acid, such as corrosiveness or reactivity, needs to be reduced at room temperature, thereby reacting the phosphoric acid with a metal hydroxide compound to form a phosphate, thereby preventing the effect as a free acid. The present invention relates to a method for forming a new crystalline inorganic material having an intermediate function of metal and phosphoric acid.

       In general, the metal hydroxide compound, for example, aluminum hydroxide to be addressed in the present invention has a variety of uses, such as resin, rubber, paper flame retardant, water treatment agent, zeolite, toothpaste, catalyst, refractory, etc., magnesium hydroxide is flame retardant Used in adsorbents, fertilizers, ceramics, artificial marble, heavy oil additives, detergents and FRP thickeners, calcium hydroxide is classified into a group of important inorganic substances used in construction, fertilizers, pulp and paper. Such metal hydroxide compounds are widely used as flame retardants belonging to one category of the present invention. For example, aluminum hydroxide, magnesium hydroxide, and calcium hydroxide, which are one of the recent concerns, have become a matter of application as a flame retardant. Aluminum hydroxide, magnesium hydroxide and calcium hydroxide, among them, aluminum hydroxide and magnesium hydroxide are known to have excellent flame retardant effect as the representative flame retardant of inorganic type, whereas the amount of addition is considerably increased compared to conventional halogen flame retardant. There is a limit to the application of these metal hydroxide compounds as flame retardants (KISTI In-depth Information Analysis Report, “Flame Retardants”, 2002. 12).

       Examining the use of the metal hydroxide compound as a flame retardant, which is a concern of the functional aspect of the phosphate of the present invention, most of the conventional flame retardants are bromine or bromine and antimony trioxide, phosphorus and chlorine, etc. In the case of flame retardants, it is urgent to replace them with non-toxic non-halogen flame retardants due to gas generation during injection and the possibility of dioxin generation during incineration.In addition, antimony trioxide flame retardants are mixed with halogen flame retardants to produce synergistic effects. It is known that the flame retardancy is limited when used alone. Phosphorus-based flame retardant is one of the effective flame retardants by forming a carbon film by dehydration of polymetaphosphoric acid, a principle of flame retardant mechanism. While it is used as a material, the flammable disadvantage of organic phosphoric acid is known to have an extremely limited application field. Inorganic systems that can be used instead of organophosphates are known to have corrosiveness, invasiveness, reactivity, etc., so that inorganic phosphoric acid is generally not used as a flame retardant unless the function as a free acid is properly controlled. Inorganic salts such as phosphate and ammonium phosphate are used in the field of flame retardants.

       As a method of increasing the utilization of the metal hydroxide compound, in the case of aluminum hydroxide in the form of boehmite (Boehmite) to synthesize the intermediate having thermal stability such as -AlOOH, -AlOOH US Patent 7029551, US Patent 6686053, U.S. Patent No. 6429172 introduces a patent for a method of forming boehmite which is thermally stable than aluminum hydroxide, more than magnesium hydroxide, and has a thermal decomposition of about 15% even at 500 ° C or higher, but 200 ° C is synthesized for the synthesis of -AlOOH and -AlOOH. Formed by a long time reaction at the high temperature mentioned above, the possibility of using it as a heat stable material or a flame retardant is proposed. As another method of increasing the utilization of metal hydroxide compounds as flame retardants, Japanese Patent 2004-269352 adopts a method of supporting manganese hydroxide compounds, which are hydrolyzates of transition metals, on the surface of aluminum hydroxide, that is, manganese hydroxide and manganese oxide. Hydrate, bivalent and trivalent iron hydroxide, cobalt hydroxide, cobalt oxide, and the like is composed of a flame retardant aid of aluminum hydroxide, in this case, the coloring of the supporting auxiliary flame retardant is generated, in particular affecting the color of the polymer material Contains restrictions that can be applied when none are available.

       As dealt with in the present invention, a method or a design for expanding the function of the metal hydroxide compound which can be applied to aluminum hydroxide, magnesium hydroxide, and calcium hydroxide by broadening the scope of application of the metal hydroxide compound has not yet been proposed. It should be said that the invention is simple and the reaction temperature or the reaction range is relatively low and various, and thus the production method is not difficult.

The present invention provides a solution to the above-mentioned problems, the metal hydroxides, especially aluminum hydroxide, magnesium hydroxide and calcium hydroxides of their own environmental friendliness and hydrates of these inorganic substances generated at high temperatures without the generation of toxic gases during pyrolysis process To give synergy to the effect of the process of absorbing ambient heat, inorganic and organic phosphates are reacted with the metal hydroxide compound to form a new phosphate salt of the metal hydroxide compound. It is an object of the present invention to provide a method for forming physicochemically stabilized metal hydroxide phosphate.

The present invention provides the addition of phosphoric acid to metal hydroxide compounds to form metal hydroxide phosphates from which metal hydroxide phosphates serve as new stabilized inorganic salts, for example, metal hydroxide compounds as flame retardants, ie aluminum hydroxide, magnesium hydroxide, calcium hydroxide. This branch has the role and synergistic effect of phosphoric acid in addition to the flame retardant function, and is characterized in that it is expected to be applied in some cases by increasing or decreasing the thermal decomposition function of the newly formed phosphate.

       The metal hydroxide compound used in the present invention, specifically, aluminum hydroxide, magnesium hydroxide, calcium hydroxide belongs to the base material which has many uses by itself, in view of the flame retardant which is an application field of the present invention still has a range of applications as expected. It is not widening. The main reason for this is that the pyrolysis temperature of the metal hydroxide compound is relatively low, and it is interpreted that the improvement of the input amount to obtain a flame retardant effect is still insufficient.

       Phosphorus-based compounds used to form phosphates of the metal hydroxide compound in the present invention are inorganic phosphoric acid (phosphoric acid, orthophosphoric acid), pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid (tetrapolyphosphoric acid) , Trimetaphosphoric acid, phosphoric anhydride and polyphosphoric acid, and trimethyl phosphate and hexamethyl phosphoric triamide as organic compounds. The addition reaction forms phosphate.

       The form of the metal hydroxide phosphate used in the present invention can be divided into three types, aluminum hydroxide phosphate, magnesium hydroxide phosphate, calcium hydroxide phosphate, which allows the formation of inorganic salts having a significantly different reaction molar ratio. That is, the reason for varying in the form of phosphate produced according to the form of phosphoric acid reacting with the metal hydroxide compound may be explained through the structure of the reactants as follows.

       First, as a specific example of the metal hydroxide compound, aluminum hydroxide has a structure as shown in the following figure (1), so that three hydroxyl sites (-OH-) form three reaction sites that react with the weak acid. . Magnesium hydroxide (Mg (OH) 2) and calcium hydroxide (Ca (OH) 2), which have similar structures, have two reaction sites, because they have two hydroxyl groups in a similar form to aluminum hydroxide.

                                      (One)

        In the present invention, the phosphoric acid reacting with the basic skeleton is represented by using various inorganic phosphoric acid and organic phosphoric acid as a reactant. Specific examples of phosphoric acid (phosphoric acid and orthophosphoric acid) are shown in the following figure (2). As can be formed three acid groups (-H +) and also three reaction sites with weak bases. As the macromolecular phosphoric acid, the pyrophosphoric acid proposed in the present invention has a structure in which the diphosphoric acid dehydrated by one molecular phosphoric acid has a structure as shown in Fig. (3). The tripolyphosphoric acid shown in Fig. (4) is similar to pyrophosphoric acid and two water molecules are dehydrated and the reaction site of the acid group has five reaction sites. Tetrapolyphosphoric acid in (5), trimetaphosphoric acid in Figure (6), and phosphoric anhydride in Figure (7) have the same reaction site as each acid group. Phosphoric acid, polyphosphoric acid, can form n + 2 reaction sites when the polymer form of phosphorus (P) is expressed as [Hn + 2PnO3n + 1]. .

            (2) (3) (4)

            (5) (6) (7)

In addition, the organic phosphoric acid trimethyl phosphate (trimethyl phosphate) and hexamethylphosphoric triamide (hexamethylphosphoric triamide), the reaction site is connected to the methyl group or amide group, and may be reactive depending on the reaction conditions.

       In the reaction form of the metal hydroxide phosphate used in the present invention, due to the above-mentioned diversity of reactivity, as the metal hydroxide compound, each of three hydroxyl groups of aluminum hydroxide and each acid group of phosphoric acid can cause a coupling reaction. When various phosphates are formed by the number of branches, in the case of magnesium hydroxide, the formation of phosphate induced by the coupling reaction by two hydroxyl groups and the acid groups according to the type of phosphoric acid, and in the case of calcium hydroxide, two hydroxyl groups and also the type of phosphoric acid It appears in the form of binding reaction by acid groups. Therefore, it is complicated and tedious to explain all these reaction forms, and here we will describe the case where one mole of aluminum hydroxide (Al (OH) 3) reacts with one mole of acid group (-H +) of phosphoric acid to form a salt. It can be expressed by the following reaction steps.

(1) Formation of aluminum hydroxide orthophosphate

       Al (OH) 3 + H3PO4 ----> (OH) 2-Al- (OH)-+ H + -O-P (= O)-(OH) 2

                      ----> (OH) 2-Al- (OH): (HO) -P (= O)-(OH) 2

 (2) forming aluminum hydroxide pyrophosphate

  Al (OH) 3 + H4P2O7 ----> (OH) 2-Al- (OH)-+ H + -O-P (= O) (-OH) -O-P (= O) (-OH) 2

                     ----> (OH) 2-Al- (OH): (HO) -P (= O) (-OH) -O-P (= O) (-OH) 2

(3) forming aluminum hydroxide tripolyphosphate

  Al (OH) 3 + H5P3O10 ----> (OH) 2-Al- (OH)-+ H + -OP (= O) (-OH) -OP (= O) (-OH) -OP (= O ) (-OH) 2

                     ----> (OH) 2-Al- (OH): (HO) -P (= O) (-OH) -O-P (= O) -OH) -O-P (= O) (-OH) 2

 (4) forming aluminum hydroxide polyphosphate

 Al (OH) 3 + Hn + 2PnO3n + 1 ---> (OH) 2-Al- (OH)-+ H + O- [P (= O) (-OH) -O-] n-1-P (= O) (-OH) 2

             ----> (OH) 2-Al- (OH): (HO)-[P (= O) (-OH) -O-] n-1-P (= O) (-OH) 2

In the case of all possible reactions in which the metal hydroxide compound and the phosphoric acid metal phosphate formed by the reaction of the present invention can be produced, the reaction moles of the hydroxyl group (-OH-) of aluminum hydroxide and the acid group (-H +) of phosphoric acid Since the number of moles can be formed separately, for example, aluminum hydroxide has 3 moles of hydroxyl groups and can react with 3 moles of acid groups of phosphoric acid, whereas phosphoric acid has 3 moles of acid groups and can react with 3 moles of hydroxyl groups of aluminum hydroxide. have. Therefore, the molar ratio of aluminum hydroxide to phosphoric acid is 1: 3 to 3: 1, that is, the ratio of aluminum hydroxide to phosphoric acid is 1: 3 (33% molar ratio of aluminum hydroxide), 1: 2, 1: 1 And 2: 1, 3: 1 (300% molar molar ratio based on aluminum hydroxide), and in addition to the above integer ratio, 2: 3 (66% molar molar ratio based on aluminum hydroxide) or 3: 2 (hydroxyl). Reaction molar ratios corresponding to the above categories, such as 150% based on aluminum).
That is, as described above, it can be seen that the number of reactions in which metal hydroxide and phosphoric acid react to generate metal hydroxide phosphate may exist in various forms in one product in a molar ratio.
For example, in the case of aluminum hydroxide phosphate, the reaction molar ratio of aluminum hydroxide and phosphoric acid is composed of one or more reaction molar ratios selected from the group consisting of 1: 2, 1: 1, 2: 1, and 3: 1, and magnesium hydroxide phosphate is hydroxide hydroxide. The reaction molar ratio of magnesium and phosphoric acid is composed of one or more reaction molar ratios selected from the group consisting of 1: 1, 1: 2, and 2: 1, and calcium hydroxide phosphate has a molar ratio of calcium hydroxide and phosphoric acid of 1: 1, 1: And at least one reaction molar ratio selected from the group consisting of 2 and 2: 1.

       The metal hydroxide compound described in the present invention also corresponds to magnesium hydroxide and calcium hydroxide. By the above method, magnesium hydroxide has 2 moles of hydroxyl groups, which can react with 2 moles of phosphoric acid to form magnesium hydroxide phosphate, and calcium hydroxide. Figure 2 has a molar hydroxyl group and reacts with 2 moles of phosphoric acid to form calcium hydroxide phosphate, it is possible to form a variety of reaction molar ratio as the reaction of the aluminum hydroxide and phosphoric acid described above.

       Phosphoric acid used in the present invention, including phosphoric acid (phosphoric acid or orthophosphoric acid), and pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, etc., in which the phosphoric acid is dehydrated with each other, the same molecular weight, The reaction, the reaction with magnesium hydroxide, the reaction with calcium hydroxide is made, which will not be described herein.

       Hereinafter, the present invention will be described in more detail with reference to Examples. In the present Example, specific examples of the metal hydroxide compound of the present invention, such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and phosphoric acid reacting thereto, include phosphoric acid. It is too cumbersome to explain all the examples of the metal hydroxide compound phosphate obtained by reacting pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid and trimethyl phosphate and trimethyl phosphate and hexamethyl phosphate triamide in the reaction molar ratio which can form a reaction, respectively. In the case of aluminum hydroxide and magnesium hydroxide, only the phosphate reaction process of the present invention will be described, and the phosphoric acid to be reacted with it is limited to one substance of phosphoric acid (phosphoric acid or orthophosphoric acid). Thus, examples of metal hydroxides, which are omitted from the description of the present embodiment, are considered to be within the scope of the present invention for examples of products that can be formed by all the reactants described above in the case of calcium hydroxide and also in all cases of polymeric phosphoric acid.

           The metal hydroxide phosphate of the present invention is formed as a salt by the addition reaction of the metal hydroxide compound and phosphoric acid, and a change occurs in the amount of metal hydroxide phosphate which is a product obtained according to the molar ratio of the metal hydroxide compound and phosphoric acid. The main reason for the change in phosphate production is due to the difference in the degree of hydroxyl groups and acid groups participating in the reaction when forming metal hydroxide phosphate.In the case of using inorganic phosphoric acid, water is used as a reaction medium. In this case, the yield of the metal hydroxide phosphate obtained as a solid content is decreased when the molar ratio of phosphate participating in the reaction is high.However, if the phosphate formation reaction is continued, the filtrate is filtered. Yield can be increased by reusing as tea and tertiary starting materials.

       In the present invention, the result of the reaction of aluminum hydroxide, magnesium hydroxide and calcium hydroxide with orthophorphoric acid and polymeric phosphoric acid resulted in the formation of aluminum hydroxide and magnesium hydroxide phosphate. Indicates.

(1) Al (OH) 3: H3PO4 = 1: 1 reaction example-156 grams (98% purity, 1.96 gram mol) of aluminum hydroxide powder was dissolved in 1000 grams of DFW to form a slurry, and the slurry liquid was then heated to 90 ° C to 95 ° C. 196 grams (1.70 grams mole) of phosphoric acid with 85% purity were reacted in a dropwise manner. The water evaporated when the phosphoric acid was added dropwise to the aluminum hydroxide slurry was condensed by a condenser to reflux and synthesized aluminum hydroxide phosphate through a reaction and aging for 2 hours. The synthesized product slurry was cooled, washed with DFW to neutralize the pH of the wash, filtered and dried to give 173 grams (0.98 grams mole, 100% yield, 58% yield) of the product.

(2) Al (OH) 3: H 3 PO 4 = 2: 1 Example of Reaction-A slurry containing 520 grams (6.53 gram mole) of aluminum hydroxide powder in 800 grams of DFW was maintained at 85 ° C. or higher and 384 grams of phosphoric acid with 85% purity. (3.33 gram mole) was added dropwise and reacted for 2 hours. The solid was filtered through the same method as in (1), washed with DFW, and dried to obtain 518 grams (2.04 gram mole, 61% yield) of the reaction product.

(3) Al (OH) 3: H 3 PO 4 = 3: 1 Example of reaction-780 grams (9.8 gram mole) of aluminum hydroxide powder was added to 1000 grams of DFW, maintaining the temperature of the slurry at 90 ° C. or higher and 384 grams of phosphoric acid with 85% purity. (3.33 gram mole) was added dropwise and reacted for 3 hours, followed by the same method as in (1), to obtain 1028.5 grams (3.10 gram mole, 95% yield) of the final reaction product.

(4) Al (OH) 3: H 3 PO 4 = 1: 2 Example of reaction-78 grams (0.98 gram mole) of aluminum hydroxide was added to DFW 600 and the slurry temperature was maintained at 80 to 90 ° C. Gram (1.96 gram mole) was added dropwise to give 1 hour reaction and 1 hour aging to give 181.5 grams (0.66 gram mole, 66% yield) of solid final product of the reaction product in the same manner as in (1) above. .

(5) Mg (OH) 2: H 3 PO 4 = 1: 1 reaction example-A slurry containing 205 grams (95% purity, 3.34 gram mol) of magnesium hydroxide powder in 600 grams of DFW was maintained at a temperature of 90 ° C. or higher and 85% of phosphoric acid. Magnesium hydroxide phosphate was synthesized by dropping 384 grams (3.33 gram mole) and then proceeding for 2.5 hours. After synthesis, the slurry was subjected to the same filtration, washing, and drying process as in (1) to obtain a reaction product of 460 grams (2.94 gram mole based on 100%, 88% yield).

(6) Mg (OH) 2: H 3 PO 4 = 2: 1 Example of Reaction-A slurry containing 260 grams of magnesium hydroxide (4.24 grams mol) in 600 grams of DFW was maintained at 90 ° C. and 244 grams (2.12 grams mol) of 85% phosphoric acid. Was added dropwise and reacted for about 3 hours to synthesize magnesium hydroxide phosphate. After synthesis, the mixed product was filtered, washed, and dried in the order of (1) to obtain 391 grams (1.82 gram mole, 86% yield) of a compound.

(7) Mg (OH) 2: H 3 PO 4 = 1: 2 Example of reaction-65 grams (1.06 gram mol) of magnesium hydroxide was added to 800 grams of DFW and the slurry was kept at 80-90 ° C. with 244 grams of 85% phosphoric acid (2.12) Gram mole) was reacted for 3 hours to give 88 grams (0.35 gram mole, 33% yield) as a final solid powder.

       A generalized process diagram for phosphate synthesis of the metal hydroxide compound by the seven reactions shown as an example in the present invention is shown in FIG. 1, and the synthesis results according to the various reaction molar ratios can be summarized as follows.

(a) In the reaction of aluminum hydroxide with phosphoric acid, the yield is high when the reaction ratio of aluminum hydroxide is high.

(b) The reaction yield of magnesium hydroxide is higher than that of aluminum hydroxide.

       The result of the reaction of pure aluminum hydroxide (Al (OH) 3) and magnesium hydroxide (Mg (OH) 2) with the final products (1) to (7) obtained as a result of the reaction in the present invention, ie for example ( 2) XRD, DSC & TGA (or SDT in total) and SEM were measured to compare the physical properties of the products according to various reaction molar ratios including Al (OH) 3: H3PO4 = 2: 1 reaction product. The results of the synthesis examples are shown in Figure 2 (XRD photo), Figure 3 (DSC & TGA photo) and Figure 4 (SEM photo).

       As shown in FIG. 2, in the X-ray diffraction (XRD) experiment, the value of 2 of aluminum hydroxide is shown as the main peak at 18 ° and 20 °, whereas aluminum hydroxide phosphate (for example, phosphoric acid: aluminum hydroxide = 2: 1). The value of 2) is explained by interference with other crystal structures in addition to the main peak of existing aluminum hydroxide. Synthesis examples in which the reaction molar ratio of phosphoric acid and aluminum hydroxide are different show similar distributions of two values as a result of the phosphoric acid: aluminum hydroxide = 2: 1 reaction. Magnesium hydroxide phosphate also showed major peaks at magnesium hydroxide 2 at 18 °, 38 °, 51 °, and 59 °, whereas magnesium hydroxide phosphate was newly found at 11 ° and 27 °. Summarizing this, the two values of XRD measurements when the reaction molar ratio of phosphate is larger in the reaction of magnesium hydroxide (or aluminum hydroxide) and phosphate are more complicated, suggesting that the crystal shape is changing to a more complex structure.

       In Figure 3 showing the results of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), some dissolution began to occur in the vicinity of 230 ° C in the case of aluminum hydroxide, and then peaked at 307.5 ° C and 737 J / g up to 370 ° C. Absorption of the heat of dissolution and approximately 70% of the structure has changed from 259.16 ° C to 381.0 ° C, whereas the peak temperature of 116.9 ° C for aluminum hydroxide phosphate (e.g. aluminum hydroxide: phosphoric acid = 2: 1 reaction). Starting from a thermal change in which some of the aluminum hydroxide phosphate causes thermal decomposition and absorbs heat of 84.0 J / g, after which a small amount of thermal change occurs at 248.7 ° C, followed by a peak at 304.9 ° C and up to 370 ° C. It exhibits heat absorption and pyrolysis behavior similar to that of aluminum hydroxide. From this, it can be seen that phosphoric acid is decomposed at about 120 ° C. in the crystal structure of the aluminum hydroxide phosphate used in the present invention. In the reaction of aluminum hydroxide with phosphoric acid, the amount of heat of dissolution of aluminum is large in the DSC measurement.In the same example, the molar ratio of phosphoric acid and aluminum hydroxide is the same as the heat of absorption and decomposition of aluminum hydroxide. The magnitude of the heat of absorption appears to have a similar scale. Pyrolysis of magnesium hydroxide is compared with the heat of fusion, which occurs at about 400 ° C as a peak, and has a more complicated decomposition form than that of aluminum hydroxide phosphate during pyrolysis of magnesium hydroxide phosphate. 4 shows the scanning electron microscope (SEM) measurement results magnified 10000 times, and the crystal structure of aluminum hydroxide is about 10 μm in size, whereas in aluminum hydroxide phosphate, it is less than 1 μm around a large crystal having a size of 10 μm. You can see small crystals growing. Magnesium hydroxide appears to grow in particle size, taking the form of phosphate in the form of small particles.

       2 to 4 show the physical and chemical changes in the reaction of the metal hydroxide compound of the present invention, for example, aluminum hydroxide and magnesium hydroxide, and phosphoric acid reacting thereto, specifically, phosphoric acid. In addition, the results measured by SEM have been described in comparison, and in other specific examples already mentioned in the present invention, for example, a metal hydroxide compound, calcium hydroxide is added, and a specific example to be added in the above-described phosphoric acid reacting thereto is pyro Phosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid, polyphosphoric acid, trimetaphosphoric acid, phosphoric anhydride, and the like are reacted with trimethyl phosphate, hexamethyl phosphate triamide, etc. in an organic system, and the reaction equivalents of the metal hydroxide compound and phosphoric acid are respectively In compounds, the equivalents of hydroxyl groups can be changed; in phosphoric acids, the equivalents of acid groups can be changed. Can do, because they can be given the physical and chemical changes in the resulting product of all those reactions it will be described the features of the product with the contents as follows.

(a) The phosphate of the metal hydroxide compound obtained in the reaction of the metal hydroxide compound presented in the present invention with the phosphoric acid proposed in the present invention is shown to share the properties of the metal hydroxide compound and the property of phosphoric acid,

(b) the thermal decomposition characteristics of metal hydroxide compounds and the pyrolysis characteristics of phosphoric acid in the form of reaction molar ratios;

(c) In the case of reactive phosphoric acid, low molecular weight phosphoric acid shows characteristics of low molecular weight phosphoric acid, and high molecular weight phosphoric acid shows characteristics of high molecular weight phosphoric acid.

As described above, the present invention forms a phosphate of a metal hydroxide compound by a relatively low reaction conditions and a gentle method, specifically forming aluminum hydroxide phosphate, magnesium hydroxide phosphate, calcium hydroxide phosphate, the phosphoric acid is in the form of inorganic substances and salts In the method of forming a metal hydroxide phosphate having a new structure crystallized with phosphate, the reactive phosphoric acid for phosphate formation is selected from the group consisting of phosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid, polyphosphoric acid, trimetaic acid and phosphoric anhydride. By selecting trimethyl phosphate and hexamethyl phosphate as an organic system, the phosphate of a metal hydroxide compound is designed to have various pyrolysis processes from a relatively low temperature to a high temperature distribution even in a pyrolysis process. In this way, when the metal hydroxide compound phosphate acts as a filler, reactant, or catalyst of an inorganic salt including a flame retardant, it forms a composition having high miscibility and storage stability so as not to cause coloring phenomenon or physical or chemical change.

Claims (4)

delete delete delete A first step of dispersing the crystalline powder of the metal hydroxide compound in a solvent to form a slurry; To prepare a metal hydroxide phosphate comprising a second step of dropping a phosphorus compound containing an organic phosphorus compound or an inorganic phosphorus compound to the metal hydroxide compound slurry prepared in the first step,  The metal hydroxide compound is calcium hydroxide, the metal hydroxide phosphate is calcium hydroxide phosphate, The inorganic phosphorus compounds include phosphoric acid (phosphoric acid and orthophosphoric aicd), pyrophosphoric aicd, tripolyphosphoric aicd, tetrapolyphosphoric acid, polyphosphoric acid, trimetaphosphoric acid ) And any one or more phosphorus compounds are selected from the group consisting of phosphoric anhydride, and the organic phosphorus compounds are any one or more from the group consisting of trimethyl phosphate and hexamethylphosphoric acid triamide. Phosphorous compounds are selected to react with the metal hydroxide compound, As the metal hydroxide phosphate, The calcium hydroxide phosphate has a reaction molar ratio of the calcium hydroxide and the phosphoric acid is composed of any one of the reaction molar ratio selected from the group consisting of 1: 1, 1: 2 and 2: 1, flame retardant metal hydroxide phosphate manufacturing method .

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