Preparation method and application of phosphate-based adhesive

Abstract

The invention relates to the technical field of inorganic adhesive production, and particularly discloses a preparation method and application of phosphate-based adhesive. According to the invention, trivalent chromium ions are introduced into the phosphoric acid solution or the aluminum-containing phosphoric acid solution through an electrolytic method to obtain the phosphate-based adhesive, so that the use of chromium trioxide is completely avoided, the generation of harmful substances in the production process is reduced, the burden of treating and disposing the harmful substances is also avoided, and the green environmental protection property of the production process is improved; meanwhile, no by-product is generated in the reaction process, the atom utilization rate of the chemical reaction is greatly increased, and efficient atom economy is achieved; moreover, the metal chromium is converted into trivalent chromium ions through an electrolytic method, so that additional chemical reagents are avoided, the utilization efficiency of raw materials in the reaction is improved, and the generation of waste materials is reduced. According to the preparation method of the phosphate-based adhesive, the technological process is simplified, energy consumption and material consumption are reduced, the preparation method is more environmentally friendly and economical, and industrial production is easier to achieve.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic adhesive production, and in particular relates to a preparation method and application of phosphate-based adhesive. Background Art

[0002] Phosphate-based adhesives have the characteristics of high bonding strength, good heat resistance, excellent dielectric properties, good oxidation resistance and water resistance, and low curing temperature, and can even be cured at room temperature, and are widely used in various rockets, missiles and space shuttles. Among them, chromium phosphate or chromium aluminum phosphate adhesives have good thermal stability, plasticity and adhesion. In terms of mechanical properties, the brittleness of this type of adhesive is reduced, the toughness is enhanced, and it is not easy to crack. The viscosity of the matrix is ​​lower than that of aluminum phosphate adhesives, so more fillers can be added when preparing composite materials. Moreover, due to the addition of chromium, in terms of material processing, the room temperature reaction activity of chromium phosphate or chromium aluminum phosphate adhesives is low, and it is not easy to stick to the mold when making composite materials or sintering materials. As the temperature rises, the chromium aluminum phosphate adhesive will gradually dehydrate and solidify, lose its bound water, and form a P2O5-Al2O3-Cr2O3 complex that melts below 1800°C without decomposition, and does not form a low eutectic with the filler, so it can be used as a high-temperature adhesive. The introduction of trivalent chromium ions also greatly enhances the storage stability of chromium aluminum phosphate or chromium phosphate matrix, for example, it can effectively prevent the phenomenon that it crystallizes at a lower temperature and becomes unusable. In the prior art, the introduction of trivalent chromium ions to prepare adhesives requires the reduction of chromium trioxide to obtain trivalent chromium ions by heating decomposition or reduction, which has the problems of cumbersome preparation methods and low efficiency. In addition, since chromium trioxide is extremely toxic, special attention should be paid to safety issues when using chromium trioxide to prepare adhesives.

[0003] In order to solve the above problems, Chinese patent application publication number CN118440603A provides a phosphate-based adhesive and a preparation method thereof, wherein impurity ions are incorporated into an aluminum phosphate adhesive system in the form of trivalent metal nitrates, and a method for preparing the phosphate-based adhesive is obtained by a double decomposition reaction; Chinese patent CN117777865A provides a phosphate-based adhesive and a preparation method thereof, wherein impurity ions are incorporated into an aluminum phosphate adhesive system in the form of trivalent metal halides, and a method for preparing the phosphate-based adhesive is obtained by a double decomposition reaction; both of the above preparation methods do not require a reduction reaction and directly use trivalent metals, but there is still the problem of generating acidic gases such as NO2 / HX when preparing the phosphate-based adhesive, and these by-products require additional treatment, which increases the production complexity and environmental burden.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for preparing a phosphate-based glue and its application. The present invention adopts an electrolytic method to directly introduce trivalent chromium ions into a reaction system to prepare a phosphate-based glue, which not only reduces the use of harmful chemicals and the generation of by-products, but also simplifies the process flow, reduces energy consumption and material consumption, greatly improves the atomic economy of the chemical reaction, and makes the entire preparation process more environmentally friendly and economical.

[0006] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0007] The first object of the present invention provides a method for preparing a phosphate-based adhesive, the preparation method comprising:

[0008] (1) preparing a phosphoric acid solution or a phosphoric acid solution containing aluminum;

[0009] (2) The zero-valent metallic chromium is converted into trivalent chromium ions through an electrolytic reaction and dissolved in a phosphoric acid solution or an aluminum-containing phosphoric acid solution to obtain a phosphate-based glue.

[0010] The present invention directly introduces the required trivalent chromium ions into the phosphate-based glue reaction system by electrolysis, completely avoiding the use of chromium trioxide, reducing the generation of harmful substances in the production process, and also avoiding the burden of processing and disposing of these harmful substances, thereby improving the green environmental protection of the production process; at the same time, no other by-products are generated in the reaction process, which greatly improves the atomic utilization rate of the chemical reaction, which means that almost all reactants are converted into target products, achieving efficient atomic economy. The present invention directly converts metallic chromium into trivalent chromium ions by electrolysis, avoiding additional chemical reagents, thereby improving the utilization efficiency of raw materials in the reaction, reducing the generation of waste, simplifying the process flow, and reducing energy consumption and material consumption.

[0011] In the above technical solution, when the electrolysis reaction is carried out, the inert electrode serves as the cathode and the metal chromium serves as the anode.

[0012] Optionally, the purity of the metallic chromium is above 98%. The higher the purity of the metallic chromium, the more favorable it is to avoid introducing other impurity ions into the reaction system.

[0013] Optionally, the inert electrode is selected from at least one of a carbon electrode, a platinum electrode, and a gold electrode.

[0014] Optionally, the mass fraction of phosphoric acid in the phosphoric acid solution is 10% to 100%.

[0015] Optionally, the mass fraction of phosphoric acid in the phosphoric acid solution is 85%.

[0016] The optional electrolysis reaction can be carried out in an electrolysis device, which includes a power supply, a cathode and a cathode, a beaker, a stirring and heating device, a phosphoric acid solution or a phosphoric acid solution containing aluminum.

[0017] In the above technical solution, the quality of the introduced trivalent chromium ions is controlled by controlling the quality of the electrolyzed metallic chromium.

[0018] Alternatively, the quality of the electrolytic metallic chromium can be controlled by controlling the voltage and / or time of the electrolytic reaction and / or the contact area between the metallic chromium and the phosphoric acid solution or the aluminum-containing phosphoric acid solution.

[0019] Optionally, the mass of the introduced trivalent chromium ions does not exceed 50% of the mass of the phosphoric acid.

[0020] Optionally, the mass of the introduced trivalent chromium ions is 0.2%-15% of the mass of the phosphoric acid.

[0021] Optionally, the voltage of the electrolysis reaction is 12V.

[0022] The present invention can use metal chromium of any shape, wherein a metal chromium rod is used as an example. The specification of the metal chromium rod is 10 mm in diameter and 100 mm in length.

[0023] In the above technical solution, when the electrolysis reaction is carried out, the temperature of the system is controlled to be 10°C-40°C.

[0024] Optionally, the temperature of the system is controlled to 25°C.

[0025] The electrolytic method of introducing trivalent chromium ions into the reaction system can be carried out at room temperature. The electrolytic reaction mainly relies on the action of electric current passing through phosphoric acid or aluminum-containing phosphoric acid solution to drive the ion reaction. The temperature of the electrolytic cell usually does not need to be specially heated, but the rate at which metallic chromium dissolves in the reaction solution can be controlled by adjusting the reaction temperature.

[0026] The second object of the present invention is to provide a method for preparing a chromium phosphate-based glue, comprising:

[0027] (1) preparing a phosphoric acid solution;

[0028] (2) An inert electrode is used as a cathode and metal chromium is used as an anode, and inserted into a phosphoric acid solution to perform an electrolytic reaction to obtain a chromium phosphate-based glue.

[0029] The present invention has no strict restrictions on the mass of trivalent chromium ions electrolyzed, but usually in chromium phosphate-based glue, the mass of chromium is generally not more than 50% of the mass of phosphoric acid. The specific ratio can be appropriately adjusted according to application requirements and actual process conditions to achieve the desired effect.

[0030] The third object of the present invention is to provide a method for preparing an aluminum chromium phosphate-based glue, comprising:

[0031] (1) preparing a phosphoric acid solution;

[0032] (2) An inert electrode is used as the cathode and metal chromium is used as the anode, which are inserted into a phosphoric acid solution to carry out an electrolytic reaction;

[0033] (3) After the reaction is completed, an aluminum source is added to the reaction system to obtain aluminum chromium phosphate-based glue.

[0034] The fourth object of the present invention is to provide another method for preparing a chromium aluminum phosphate-based glue, comprising:

[0035] (1) preparing a phosphoric acid solution, adding an aluminum source, and completely dissolving the aluminum source to obtain an aluminum-containing phosphoric acid solution;

[0036] (2) An inert electrode is used as a cathode and metallic chromium is used as an anode, and inserted into a phosphoric acid solution containing aluminum; an electrolytic reaction is performed to obtain an aluminum chromium phosphate-based glue.

[0037] In the above technical solution, the aluminum source is selected from one or more of aluminum hydroxides, oxides or nitrides.

[0038] Optionally, the aluminum source is aluminum hydroxide.

[0039] The present invention has no strict restrictions on the mass of the aluminum source input, but usually in the aluminum chromium phosphate base glue, the molar ratio of chromium to aluminum hydroxide does not exceed 1:1, and the total mass of the chromium source and the aluminum source generally does not exceed 50% of the mass of phosphoric acid. The specific ratio can be appropriately adjusted according to application requirements and actual process conditions to achieve the desired effect.

[0040] When adding an aluminum source to the reaction system or preparing an aluminum-containing phosphoric acid solution, the dissolution rate of the aluminum source can be accelerated by heating.

[0041] The fifth object of the present invention is to provide a use of a phosphate-based glue in the preparation of an inorganic adhesive.

[0042] Alternatively, the phosphate-based glue is used directly as an adhesive.

[0043] Alternatively, phosphate-based glues can be used as adhesives by heating to evaporate the water.

[0044] Optionally, the heating temperature is 80°C-250°C.

[0045] Optionally, the heating temperature is 150°C.

[0046] The phosphate-based adhesive provided by the present invention can evaporate excess water through subsequent heating to obtain a phosphate-based adhesive with a higher density. The phosphate-based adhesive with a higher density has better mechanical properties and a lower shrinkage rate when used as an adhesive, and can maintain better stability in a humid environment.

[0047] The sixth object of the present invention is to provide a phosphate-based adhesive, which is made of the phosphate-based glue provided by the present invention.

[0048] Alternatively, a phosphate-based glue is mixed with a curing agent to obtain a phosphate-based adhesive.

[0049] The phosphate-based adhesive introduced with trivalent ions provided by the present invention is used to prepare an adhesive, so that the curing time of the phosphate-based adhesive mixed with a curing agent can be adjusted, and the adhesive can be cross-linked and cured at room temperature. The formation of an amorphous continuous structure during the gelling process of the phosphate-based adhesive is promoted, so that the brittleness of the adhesive is reduced, the tensile strength is high, and the adhesive is not easy to break.

[0050] The present invention has no strict restrictions on the mass ratio of the curing agent to the phosphate-based adhesive, but the mass ratio generally used is 3:1 or 2:1, which is a more common ratio range. The specific ratio can be appropriately adjusted according to application requirements and actual process conditions to achieve the desired curing effect.

[0051] Optionally, the curing agent is selected from one or more of copper oxide, aluminum oxide, calcium oxide, magnesium oxide, zinc oxide, zirconium oxide, iron oxide, chromium oxide, scandium oxide and gallium oxide.

[0052] Optionally, the curing agent is copper oxide and magnesium oxide.

[0053] After adopting the above technical scheme, the present invention has the following beneficial effects compared with the prior art.

[0054] The present invention introduces trivalent chromium ions into the phosphate-based glue reaction system by electrolysis, thereby completely avoiding the use of chromium trioxide, not only reducing the generation of harmful substances in the production process, but also avoiding the burden of processing and disposing of these harmful substances, thereby improving the green environmental protection of the production process; the present invention introduces trivalent chromium ions into the phosphate-based glue reaction system by electrolysis, and no by-products are generated in the reaction process, thereby greatly improving the atomic utilization rate of the chemical reaction and achieving efficient atomic economy; the present invention converts metallic chromium into trivalent chromium ions by electrolysis, thereby avoiding additional chemical reagents, improving the utilization efficiency of raw materials in the reaction, and reducing the generation of waste.

[0055] The present invention adopts electrolysis to introduce trivalent chromium ions to prepare phosphate-based glue, which not only reduces the use of harmful chemicals and the generation of by-products, but also simplifies the process flow and reduces energy consumption and material consumption. The atomic utilization rate of the whole process is improved, and resource waste is reduced, which complies with the atomic economy principle of green chemistry. Therefore, the preparation method of phosphate-based glue provided by the present invention is more environmentally friendly and economical, and is easier to realize industrial production.

[0056] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the drawings described below are only some embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the accompanying drawings:

[0058] Figure 1 This is a schematic diagram of the reaction of electrolyzing metal chromium to prepare a phosphate-based adhesive according to the present invention;

[0059] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0061] Example 1

[0062] Combined with Figure 1 The reaction diagram shown in the figure uses phosphoric acid solution (mass fraction of 85%) and high-purity metallic chromium (diameter 10mm×length 150mm) with a purity of more than 99.99% as raw materials to prepare chromium phosphate-based glue:

[0063] (1) Prepare an electrolysis device (including a power supply, a metal platinum electrode, a metal chromium), a stirring and heating device, a 2L three-necked flask, and an electronic balance;

[0064] (2) Weigh the mass of metallic chromium to be 84.66 g;

[0065] (3) Add 1000 mL of phosphoric acid solution to a 2 L three-necked flask at room temperature (25°C) and set the stirring speed of the stirring and heating device to 250 r / min;

[0066] (4) Use a platinum electrode as the cathode and chromium as the anode, insert the platinum electrode and chromium 10 cm below the surface of the phosphoric acid solution. Turn on the DC power supply with an output voltage of 12 V, start the electrolysis reaction, and wait until the mass of the chromium is 51.33 g. Turn off the power supply and end the electrolysis. At this time, the mass of the chromium has decreased by 33.33 g, and the reaction system has turned dark green.

[0067] (5) Adjust the heating temperature of the stirring and heating device so that the temperature in the reaction system reaches 150°C, maintain it for 2 hours to remove moisture, and then stop heating. Plug the mouth of the reaction bottle with a rubber stopper and cool it naturally to room temperature to obtain chromium phosphate-based glue.

[0068] (6) The solidification temperature range of the obtained chromium aluminum phosphate based glue was tested using an ice point meter. The test results are shown in Table 1.

[0069] Example 2

[0070] Combined with Figure 1 The reaction diagram shown in the figure uses phosphoric acid solution (mass fraction of 85%), analytically pure aluminum hydroxide and high-purity metallic chromium (diameter 10 mm × length 150 mm) with a purity of more than 99.99% as raw materials to prepare chromium aluminum phosphate-based glue with a molar ratio of aluminum ions to chromium ions of 5:1:

[0071] (1) Prepare an electrolysis device (including a power supply, a metal platinum electrode, a metal chromium), a stirring and heating device, a 2L three-necked flask, and an electronic balance;

[0072] (2) Weigh the mass of metallic chromium to be 84.66 g;

[0073] (3) Add 1000 mL of phosphoric acid solution to a 2 L three-necked flask at room temperature (25°C) and set the stirring speed of the stirring and heating device to 250 r / min;

[0074] (4) Use a platinum electrode as the cathode and chromium as the anode, insert the platinum electrode and chromium into the phosphoric acid solution 5 cm below the surface. Turn on the DC power supply, the output voltage is 12V, start the electrolysis reaction, until the mass of chromium is 78.06g, turn off the power supply, and end the electrolysis. At this time, the mass of chromium decreases by 6.6g, and the reaction system turns dark green;

[0075] (5) Add 50g of aluminum hydroxide to the above system, set the heating temperature of the stirring and heating device to 100°C, and after stirring for 0.5h, the reaction system is basically clear. Adjust the heating temperature so that the temperature in the reaction system reaches 150°C, maintain it for 2h to remove moisture, and then stop heating. Plug the mouth of the reaction bottle with a rubber stopper and cool it naturally to room temperature to obtain chromium aluminum phosphate based glue.

[0076] (6) The solidification temperature range of the obtained chromium aluminum phosphate based glue was tested using an ice point meter. The test results are shown in Table 1.

[0077] Example 3

[0078] Combined with Figure 1The reaction diagram shown in the figure uses phosphoric acid solution (mass fraction of 85%), analytically pure aluminum hydroxide and high-purity metallic chromium (diameter 10 mm × length 150 mm) with a purity of more than 99.99% as raw materials to prepare chromium aluminum phosphate-based glue with a molar ratio of aluminum ions to chromium ions of 1:1:

[0079] (1) Prepare an electrolysis device (including a power supply, a metal platinum electrode, a metal chromium), a stirring and heating device, a 2L three-necked flask, and an electronic balance;

[0080] (2) Weigh the mass of metallic chromium to be 84.66 g

[0081] (3) Add 1000 mL of phosphoric acid solution and 25 g of aluminum hydroxide to a 2 L three-necked flask at room temperature (25°C), set the heating temperature of the stirring and heating device to 100°C and the stirring speed to 250 r / min, and after stirring for 0.5 h until the aluminum hydroxide is completely dissolved, stop heating to obtain an aluminum-containing phosphoric acid solution.

[0082] (4) Use a platinum electrode as the cathode and chromium as the anode, insert the platinum electrode and chromium into the aluminum-containing phosphoric acid solution 5 cm below the surface. Turn on the DC power supply with an output voltage of 12 V, start the electrolysis reaction, and wait until the mass of the chromium is 67.99 g. Turn off the power supply and end the electrolysis. At this time, the mass of the chromium has decreased by 16.67 g, and the reaction system has turned dark green.

[0083] (5) Adjust the heating temperature of the stirring and heating device so that the temperature in the reaction system reaches 150°C, maintain it for 2 hours to remove moisture, and then stop heating. Plug the mouth of the reaction bottle with a rubber stopper and cool it naturally to room temperature to obtain chromium aluminum phosphate-based glue.

[0084] (6) The solidification temperature range of the obtained chromium aluminum phosphate based glue was tested using an ice point meter. The test results are shown in Table 1.

[0085] Table 1:

[0086] Serial number Mass of metallic chromium consumed (g) Solidification temperature range Example 1 33.33 <-20℃ Example 2 6.6 <-15℃ Example 3 16.67 <-30℃

[0087] Embodiment 4:

[0088] The chromium phosphate adhesive prepared in Example 1 was prepared using the chromium phosphate-based adhesive:

[0089] (1) Mix copper oxide and magnesium oxide in a mass ratio of 100:5, grind thoroughly, and dry in an oven at 80°C for 10 hours. After drying, pass through a 300-mesh sieve to obtain a curing agent, which is then sealed and stored;

[0090] (2) stirring and mixing 60 g of chromium phosphate-based adhesive and curing agents of different masses at room temperature to obtain a chromium phosphate adhesive;

[0091] (3) The tensile strength of the obtained adhesive was tested using a 25 mm × 12.5 mm stretch sheet. The adhesive was coated on the stretch sheet to prepare a stretch sheet sample. The tensile strength was tested after curing at room temperature for 6 h, 12 h, and 18 h. The test results are shown in Table 2.

[0092] Embodiment 5:

[0093] The chromium aluminum phosphate based glue prepared in Example 2 was used to prepare the chromium aluminum phosphate adhesive. The preparation steps were the same as those in Example 4. The tensile strength test results of the prepared adhesive are shown in Table 2.

[0094] Embodiment 6:

[0095] The chromium aluminum phosphate based glue prepared in Example 3 was used to prepare the chromium aluminum phosphate adhesive. The preparation steps were the same as those in Example 4. The tensile strength test results of the prepared adhesive are shown in Table 2.

[0096] Table 2:

[0097]

[0098] It can be seen from Table 2 that the phosphate-based adhesive prepared by the technical solution provided by the present invention has high tensile strength and is not easy to break.

[0099] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the present invention can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. A method for preparing a phosphate-based adhesive, characterized in that: include: (1) preparing a phosphoric acid solution or a phosphoric acid solution containing aluminum; (2) The zero-valent metallic chromium is converted into trivalent chromium ions through an electrolytic reaction and dissolved in a phosphoric acid solution or an aluminum-containing phosphoric acid solution to obtain a phosphate-based glue.

2. The method for preparing a phosphate-based adhesive according to claim 1, characterized in that: When the electrolysis reaction is carried out, the inert electrode acts as the cathode and the metallic chromium acts as the anode; Preferably, the purity of the metallic chromium is above 98%; Preferably, the inert electrode is selected from at least one of a carbon electrode, a platinum electrode and a gold electrode.

3. The method for preparing a phosphate-based adhesive according to claim 1, characterized in that: The quality of the introduced trivalent chromium ions is controlled by controlling the quality of the electrolyzed metallic chromium; Preferably, the mass of the introduced trivalent chromium ions is 0.2%-15% of the mass of the phosphoric acid; Preferably, the quality of the electrolytic metal chromium is controlled by controlling the voltage and / or time of the electrolytic reaction and / or the contact area between the metal chromium and the phosphoric acid solution or the aluminum-containing phosphoric acid solution; Preferably, the voltage of the electrolysis reaction is 12V.

4. The method for preparing a phosphate-based adhesive according to claim 1, characterized in that: When the electrolysis reaction is carried out, the temperature of the system is controlled to be 10°C-40°C; Preferably, the temperature of the system is controlled to be 25°C.

5. A method for preparing a phosphate-based adhesive according to any one of claims 1 to 4, characterized in that: include: (1) preparing a phosphoric acid solution; (2) An inert electrode is used as a cathode and metal chromium is used as an anode, and inserted into a phosphoric acid solution to perform an electrolytic reaction to obtain a chromium phosphate-based glue.

6. A method for preparing a phosphate-based adhesive according to any one of claims 1 to 4, characterized in that: include: (1) preparing a phosphoric acid solution; (2) An inert electrode is used as the cathode and metal chromium is used as the anode, which are inserted into a phosphoric acid solution to carry out an electrolytic reaction; (3) After the reaction is completed, an aluminum source is added to the reaction system to obtain aluminum chromium phosphate-based glue.

7. A method for preparing a phosphate-based adhesive according to any one of claims 1 to 4, characterized in that: include: (1) preparing a phosphoric acid solution, adding an aluminum source, and completely dissolving the aluminum source to obtain an aluminum-containing phosphoric acid solution; (2) An inert electrode is used as the cathode and metallic chromium is used as the anode, inserted into a phosphoric acid solution containing aluminum; Conduct electrolytic reaction to obtain aluminum chromium phosphate based glue.

8. The preparation method according to any one of claims 6 to 7, characterized in that: The aluminum source is selected from one or more of aluminum hydroxide or aluminum oxide; Preferably, the aluminum source is aluminum hydroxide.

9. Use of the phosphate-based adhesive prepared by the preparation method according to any one of claims 1 to 7 in the preparation of an inorganic adhesive; Preferably, the phosphate-based glue is used directly as an adhesive; Preferably, the phosphate-based glue is used as an adhesive after evaporating the water by heating; Preferably, the heating temperature is 80°C-250°C; Preferably, the heating temperature is 150°C.

10. A phosphate-based adhesive, made by the phosphate-based adhesive prepared by the preparation method according to any one of claims 1 to 7; Preferably, a phosphate-based adhesive is obtained by mixing a phosphate-based glue with a curing agent; Preferably, the curing agent is selected from one or more of copper oxide, aluminum oxide, calcium oxide, magnesium oxide, zinc oxide, zirconium oxide, iron oxide, chromium oxide, scandium oxide and gallium oxide; Preferably, the curing agent is copper oxide and magnesium oxide.

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