Method for producing high-purity phosphorus trifluoride

Abstract

The method for producing phosphorus trifluoride according to an embodiment of the present invention comprises reacting a metal fluoride salt and a phosphorus chloride compound solution.

Description

Method for manufacturing high-purity phosphorus trifluoride

[0001] The present invention relates to a method for producing high-purity phosphorus trifluoride.

[0002] Phosphorus trifluoride is an industrial gas that can be used, for example, as a specialty gas. Specialty gases possess a purity higher than that required for general industrial applications and are intended for specific uses. Specialty gases may include electronic and semiconductor gases, standard gases, rare gases, and mixed gases.

[0003] Specifically, phosphorus trifluoride can be used as a specialty gas for semiconductors, such as for semiconductor manufacturing and research, and for TFT-LCD production. As one example, phosphorus trifluoride can be used in the etching or cleaning processes that are part of the semiconductor fabrication process. In this case, the purity of phosphorus trifluoride can affect the etching degree and pattern formation of the semiconductor wafer. Thus, to be used as a specialty gas for semiconductors, a higher purity is required than that required for general industrial gases.

[0004] Conventional technology is known for producing phosphorus trifluoride by reacting hydrogen fluoride with a phosphorus compound. However, hydrogen fluoride, the raw material, requires special caution during handling because its strong hydrogen bonding can cause violent exothermic reactions or explosions upon contact with moisture in the air. Furthermore, since not only hydrogen fluoride but also the byproducts generated therefrom are highly acidic substances, there are significant limitations to their application in industrial settings.

[0005] Therefore, efforts are required to find safe raw materials that can replace hydrogen fluoride in the production of high-purity phosphorus trifluoride. However, in conventional technology, it is not easy to optimize processes such as chemical reaction, purification, mixing, and extraction to ensure process safety by changing the types of reactants, while simultaneously increasing the purity of phosphorus trifluoride gas.

[0006] (Prior Art) JP 1998-245211 A

[0007] One embodiment of the present invention provides a method for producing high-purity phosphorus trifluoride that can achieve excellent selectivity of the product phosphorus trifluoride while replacing hydrogen fluoride used as a reactant.

[0008] One embodiment of the present invention provides a method for producing high-purity phosphorus trifluoride that can improve the overall reaction rate or shorten the time to reach the equilibrium conversion rate of phosphorus trifluoride.

[0009] One embodiment of the present invention can provide a method for producing phosphorus trifluoride with increased purity and / or yield.

[0010] One embodiment of the present invention can provide a method for producing phosphorus trifluoride that can suppress the formation of byproduct HCl.

[0011] One embodiment of the present invention can provide a method for producing phosphorus trifluoride with improved economic efficiency by increasing the reaction rate of the phosphorus trifluoride formation reaction.

[0012] The problems of the present invention are not limited to those described above. A person skilled in the art to which the present invention pertains will have no difficulty understanding additional problems of the present invention from the overall contents of this specification.

[0013] A method for producing phosphorus trifluoride, which is an embodiment of the present invention, comprises reacting a metal fluoride salt with a phosphorus chloride compound solution.

[0014] The above phosphorus chloride compound solution is obtained by dissolving a phosphorus chloride compound in a solvent, and the solvent may be an organic solvent.

[0015] The above organic solvent may be a polar solvent.

[0016] The above phosphorus chloride compound solution is obtained by dissolving a phosphorus chloride compound in a solvent, and the solvent may be at least one selected from the group consisting of acetonitrile, (THF)tetrahydrofuran, toluene, NMP (N-methyl-2-pyrrolidone), and dimethylformamide (DMF).

[0017] The above metal fluoride salt may be a compound represented by the following chemical formula 1.

[0018] [Chemical Formula 1]

[0019] (M a ) n F m

[0020] In the above chemical formula 1, M a is an alkali metal or alkaline earth metal, and n and m are each independently 1 to 3, and said n and m are real numbers. The metal fluoride salt may be at least one selected from the group consisting of sodium fluoride (NaF), potassium fluoride (KF), calcium fluoride (CaF2) and magnesium fluoride (MgF2).

[0021] The weight ratio of the phosphorus chloride compound and the metal fluoride salt may be 1:1.5 to 1:20.

[0022] The weight ratio of the phosphorus chloride compound and the solvent may be 3:1 to 10:1.

[0023] The above phosphorus chloride compound may include phosphorus trichloride.

[0024] A method for producing phosphorus trifluoride, which is an embodiment of the present invention, may additionally include a catalyst.

[0025] The above catalyst may be a compound represented by the following chemical formula 2.

[0026] [Chemical Formula 2]

[0027] (M b ) x O m

[0028] (In the above chemical formula 2, M b is at least one selected from Sb, Fe, Sn, Ti, and Al, x is 1 or 2, and m is 1 to 3.)

[0029] The above catalyst may be a compound represented by the following chemical formula 3.

[0030] [Chemical Formula 3]

[0031] M c F l

[0032] (In the above chemical formula 3, Mc is at least one selected from Sb, Fe, Sn, Ti, and Al, and l is 3 to 4.)

[0033] The catalyst may be at least one selected from the group consisting of antimony trioxide (Sb2O3), antimony fluoride (SbF3), iron trioxide (Fe2O3), iron fluoride (FeF3), tin fluoride (SnF4), titanium fluoride (TiF4), and aluminum fluoride (AlF3).

[0034] The weight ratio of the solvent and the catalyst may be 1:0.1 to 1:0.0001.

[0035] A method for producing phosphorus trifluoride, which is an embodiment of the present invention, replaces hydrogen fluoride used as a reactant while achieving excellent selectivity for the product, phosphorus trifluoride.

[0036] A method for producing phosphorus trifluoride, which is an embodiment of the present invention, can improve the overall reaction rate or shorten the time required to reach the equilibrium conversion rate of phosphorus trifluoride.

[0037] A method for producing phosphorus trifluoride, which is an embodiment of the present invention, can increase the purity and / or yield of phosphorus trifluoride.

[0038] A method for producing phosphorus trifluoride, which is an embodiment of the present invention, can suppress the formation of HCl as a byproduct.

[0039] A method for producing phosphorus trifluoride, which is an embodiment of the present invention, can increase economic efficiency by increasing the reaction rate of the phosphorus trifluoride formation reaction.

[0040] The terms described below are defined with consideration of their functions in the present invention, and these may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification. The terms used in this specification are merely for describing the embodiments of the present invention and should not be limited in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form.

[0041] In this specification, expressions such as “include” or “comprising” are intended to refer to certain characteristics, numbers, steps, actions, elements, parts or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts or combinations thereof other than those described.

[0042] Unless otherwise specifically defined in the specification of the present invention, % units mean weight %.

[0043] Unless otherwise specifically defined in the specification of the present invention, alphabetic symbols represent the element represented by the corresponding element symbol.

[0044] The present invention will be described in detail below through each embodiment or example of the invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may also be combined with other embodiments or examples. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention.

[0045] A method for producing phosphorus trifluoride, which is an embodiment of the present invention, comprises reacting a metal fluoride salt with a solution of a phosphorus chloride compound. This method for producing phosphorus trifluoride, which is an embodiment of the present invention, replaces hydrogen fluoride used as a reactant while achieving excellent selectivity for the product, phosphorus trifluoride.

[0046] In addition, the method for producing phosphorus trifluoride, which is an embodiment of the present invention, can improve the overall reaction rate or shorten the time required to reach the equilibrium conversion rate of phosphorus trifluoride, increase purity and / or yield, suppress the formation of byproduct HCl, and increase economic efficiency by increasing the reaction rate of the production reaction.

[0047] In one embodiment of the present invention, the metal fluoride salt may be a dried metal fluoride salt or a regenerated metal fluoride salt. Specifically, the metal fluoride salt may refer to a solid compound as a salt in which a metal and fluorine are combined. In one example, the metal fluoride salt may be in an anhydrous or hydrated state. In this case, it can replace the hydrogen fluoride used as a reactant, thereby improving the safety of the entire process.

[0048] The above metal fluoride salt may be a compound represented by the following chemical formula 1.

[0049] [Chemical Formula 1]

[0050] (M a ) n F m

[0051] In the above chemical formula 1, M a is an alkali metal or alkaline earth metal, and n and m are each independently 1 to 3, and said n and m are real numbers.

[0052] When the compound of Chemical Formula 1 above is used as a metal fluoride salt, the overall process safety and reactivity can be improved to an excellent degree.

[0053] Specifically, the metal fluoride salt may be at least one selected from the group consisting of sodium fluoride (NaF), potassium fluoride (KF), calcium fluoride (CaF2), magnesium fluoride (MgF2), etc., and more specifically, may be sodium fluoride (NaF). When the compound of the above example is used as the metal fluoride salt, the overall process safety can be further enhanced while achieving excellent selectivity for the product, phosphorus trifluoride.

[0054] The above phosphorus chloride compound may include phosphorus trichloride.

[0055] In addition, the phosphorus chloride compound solution refers to a solution in which a phosphorus chloride compound is dissolved in a solvent. The solvent may be an organic solvent. Specifically, the organic solvent may be a polar solvent. Polar solvents may have superior reactivity compared to non-polar solvents.

[0056] Specifically, the solvent may be at least one selected from the group consisting of acetonitrile, toluene, (THF)Tetrahydrofuran, NMP (N-methyl-2-pyrrolidone), dimethylformamide (DMF), etc. When using the compounds of the above examples as solvents, excellent selectivity for the product phosphorus trifluoride can be achieved while further increasing overall process safety, thereby further increasing the purity and / or yield of phosphorus trifluoride.

[0057] The weight ratio of the phosphorus chloride compound and the metal fluoride salt may be 1:1.5 to 1:20. Specifically, it may be 1:2.5 to 1:10. When the weight ratio of the phosphorus chloride compound and the metal fluoride salt is within the range described above, the formation of by-products can be suppressed, and in such cases, the conversion rate and reaction yield can be further improved.

[0058] Meanwhile, the weight ratio of the phosphorus chloride compound and the solvent may be 3:1 to 10:1, specifically 4:1 to 8:1. Within this range, the solubility characteristics are improved, and the final yield may be further improved.

[0059] One embodiment of the present invention may further include a catalyst. The catalyst may shorten the time required to reach an equilibrium conversion rate.

[0060] The above catalyst may be a compound represented by the following chemical formula 2.

[0061] [Chemical Formula 2]

[0062] (M b ) x A y

[0063] In the above chemical formula 2, M bis at least one selected from Sb, Fe, Sn, Ti, and Al, A is a halogen atom or an oxygen atom, and x and y are each independently 1 to 3. The above x and y are real numbers.

[0064] When the compound of Chemical Formula 2 above is used as a catalyst, the overall process safety and reactivity can be improved to an excellent degree, and the overall reaction rate can be improved or the time required to reach the equilibrium conversion rate of phosphorus trifluoride can be shortened.

[0065] Specifically, the catalyst may be at least one selected from the group consisting of diantimony trioxide (Sb2O3), antimony fluoride (SbF3), iron trioxide (Fe2O3), iron fluoride (FeF3), tin fluoride (SnF4), titanium fluoride (TiF4), aluminum fluoride (AlF3), etc., and specifically, it may be diantimony trioxide (Sb2O3). When the compound of the above example is used as a catalyst, the effect of improving the overall reaction rate or shortening the time to reach the equilibrium conversion rate of phosphorus trifluoride may be further enhanced.

[0066] The weight ratio of the solvent and the catalyst included in the above mixture may be 1:0.1 to 1:0.0001. If the weight ratio of the catalyst to the solvent exceeds 1:0.1, economic efficiency may decrease and catalytic activity may be lowered, and if it is less than 1:0.0001, the role of the catalyst may become negligible.

[0067] A method for producing phosphorus trifluoride, which is an embodiment of the present invention, may include the steps of: introducing a metal fluoride salt into a reactor; vacuum purging the inside of the reactor with an inert gas; and introducing a phosphorus trichloride (PCl3) compound solution into the reactor to obtain a reaction product containing phosphorus trifluoride (PF3). The reactor may be a closed-type reactor. Specifically, the reactor may be a batch-type reactor.

[0068] In one embodiment of the present invention, moisture and / or oxygen inside the reactor can be removed by vacuum purging the inside of the reactor with an inert gas. In this case, the occurrence of moisture and / or oxygen inside the reactor reacting with the product phosphorus trichloride to produce the byproduct HCl is reduced, thereby further increasing the purity and / or yield of phosphorus trifluoride.

[0069] The above inert gas is not particularly limited, but may be, for example, nitrogen, helium, etc.

[0070] A method for producing phosphorus trifluoride, which is an embodiment of the present invention, may additionally perform the step of capturing, purifying, or concentrating phosphorus trifluoride from a reaction product containing phosphorus trifluoride.

[0071] In a method for producing phosphorus trifluoride according to one embodiment of the present invention, the reaction product containing phosphorus trifluoride may contain, in addition to the desired product, phosphorus trifluoride, unreacted raw materials, unreacted solvents, reaction by-products, moisture, etc., in low proportions. By additionally performing a step of capturing, purifying, or concentrating phosphorus trifluoride from the reaction product containing phosphorus trifluoride, the purity and / or yield of phosphorus trifluoride can be further increased.

[0072] The above-mentioned capture may involve capturing phosphorus trifluoride using a cold-trap method. The temperature of the cold-trap method may be -20°C or lower. Depending on the cold-trap method, other byproducts may be in a liquid or solid state, and phosphorus trifluoride in a gaseous state may be captured.

[0073] Examples

[0074] The present invention will be described in detail below through examples. However, it should be noted that the examples described below are intended only to illustrate and embody the present invention and are not intended to limit the scope of the present invention.

[0075] Examples 1 to 6

[0076] NaF dried with metal fluoride is introduced into a closed reactor and at room temperature (25 o After purging with an inert gas (N2) in C), a vacuum atmosphere was formed to sufficiently remove internal moisture and oxygen.

[0077] Afterwards, a mixed solution was prepared by mixing PCl3 with phosphorus trichloride and acetonitrile with a solvent in the weight ratios shown in Table 1 below, and then introduced into the reactor.

[0078] In the reaction product containing phosphorus trifluoride prepared as above, the formation of phosphorus trifluoride was evaluated as described in the experimental example below.

[0079] (Unit: Weight ratio) NaFPCl3Acetonitrile Example 1 2.75 10.1 Example 2 2.75 10.2 Example 3 2.75 11 Example 4 9.2 10.2 Example 5 2.5 10.2 Example 6 1 10.2

[0080] Examples 7 to 11

[0081] In the same manner as in Examples 1 to 7 above, a metal fluoride salt was introduced into a closed reactor and purged to sufficiently remove internal moisture and oxygen.

[0082] Subsequently, PCl3 as phosphorus trichloride, acetonitrile as a solvent, and a catalyst were mixed in the weight ratios shown in Table 2 below to prepare a mixed solution, which was then introduced into the reactor.

[0083] In the reaction product containing phosphorus trifluoride prepared as above, the formation of phosphorus trifluoride was evaluated as described in the experimental example below.

[0084] (Unit: Weight ratio) NaFPCl3 Acetonitrile Catalyst Catalyst Type Example 7 2.75 10.2 0.003 Sb2O3 Example 8 2.75 10.2 0.003 SbF3 Example 9 2.75 10.2 0.003 FeF3 Example 10 2.75 10.2 0.003 SnF2 Example 112.75 10.2 0.003 TiF4

[0085] Comparative Example 1

[0086] NaF dried with metal fluoride is introduced into a closed reactor and at room temperature (25 o After purging with an inert gas (N2) in C), a vacuum atmosphere was formed to sufficiently remove internal moisture and oxygen.

[0087] Afterwards, PCl3 was added without solvent using phosphorus trichloride in the weight ratios shown in Table 3 below to prepare a mixed solution, which was then introduced into the reactor.

[0088] (Unit: weight ratio) NaFPCl3 Comparative Example 12.751 Comparative Example 29.21

[0089]

[0090] [Experimental Examples and Evaluation]

[0091] Experimental Example 1. Preparation of Phosphorus Chloride Solution

[0092] For the phosphorus trifluoride production reaction according to an embodiment of the present invention, a phosphorus chloride compound was introduced into a closed-type reactor made of glass, and phosphorus chloride compound solutions of samples 1 to 5 were prepared by changing the type of solvent as indicated in Table 4 below. The formation of the phosphorus chloride compound solution was evaluated, and the results are shown in Table 4 below. If the phosphorus chloride compound dissolved in the solvent and there was no visually observable precipitate, the evaluation result was indicated as "O", and if the phosphorus chloride compound did not dissolve well and a large amount of precipitate was visually observable, the evaluation result was indicated as "X".

[0093] Phosphorus chloride compound solvent, Phosphorus chloride compound solution Evaluation Sample 1 PCl3AcetonitrileO2 Sample 2 PCl3TolueneO2 Sample 3 PCl3THFO Sample 4 PCl3NMPO Sample 5 PCl3CyclohexaneX2

[0094] It was confirmed that the phosphorus chloride compound solutions of samples 1 to 4 were prepared as phosphorus chloride compound solutions. On the other hand, it was confirmed that the phosphorus chloride compound of sample 5 did not dissolve and precipitated, resulting in low usability as a solution.

[0095] Experimental Examples 2 to 6. Evaluation of whether the reaction proceeds between a metal fluoride salt and a phosphorus chloride compound solution

[0096] NaF was introduced into a closed glass reactor, and the solvents presented in Table 5 were added in an amount sufficient to fully submerge the NaF. Subsequently, PCl3 was added at an equivalent ratio (molar ratio) of 1 / 3 of the NaF equivalent, and the reaction was observed. Reactivity was confirmed through the formation of bubbles and mass spectra, while the presence of side reactions in the solvent was visually inspected.

[0097] F : Cl Solvent Phosphorus Chloride Compound Solution Presence of PF3 Formation Presence of Side Reactions Experiment Example 23:1 AcetonitrileOOX Experiment Example 33:1 TolueneOOX Experiment Example 43:1 THFOO Experiment Example 53:1 NMPOOO Experiment Example 63:1 CyclohexaneXXX

[0098] It was confirmed that PF3 was formed in the phosphorus chloride compound solutions of the above sample Experiment Examples 2 to 5. Meanwhile, it was confirmed that the solvent was oxidized due to side reactions in Experiment Examples 4 and 5, and it was confirmed that PF3 was not formed in Experiment Example 6 because it was not a phosphorus chloride compound solution.

[0099] Experimental Example 7. Measurement of conversion rate and selectivity of phosphorus trifluoride

[0100] The PF3 conversion rate and selectivity for the reaction products containing phosphorus trifluoride prepared in the aforementioned Examples 1 to 12 and Comparative Example 1 were measured and are shown in Table 6.

[0101] The progress of the phosphorus trifluoride production reaction was monitored by checking the pressure gauge installed in the reactor to calculate the PF3 conversion rate after 4 hours, and unreacted acetonitrile and PCl3 were removed by flowing a dry trap at -20°C at a rate of 0.2 L / min, and the gas was collected in a collection cylinder. The PF3 selectivity was analyzed via mass spectrum.

[0102] (Unit: Weight Ratio) Conversion (%) Selectivity (%) Example 1: 258 4.6 Example 2: 429 0.9 Example 3: 327 1.7 Example 4: 968 9.3 Example 5: 378 9.4 Example 6: 307 3.1 Example 7: 469 1.57 Example 8: 439 2.37 Example 9: 379 1.25 Example 1: 1039 91.68 Example 1: 11369 2.15 Comparative Example 1: 100 Comparative Example 2: 200

[0103] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be obvious to those skilled in the art that various modifications and variations are possible within the scope of the technical concept of the present invention as described in the claims.

Claims

1. A method for producing phosphorus trifluoride comprising reacting a metal fluoride salt with a solution of a phosphorus chloride compound.

2. In Paragraph 1, The above phosphorus chloride compound solution is obtained by dissolving a phosphorus chloride compound in a solvent, The above solvent is a method for manufacturing phosphorus trifluoride, which is an organic solvent.

3. In Paragraph 2, The above organic solvent is a polar solvent used in the method for producing phosphorus trifluoride.

4. In Paragraph 1, The above phosphorus chloride compound solution is obtained by dissolving a phosphorus chloride compound in a solvent, A method for producing phosphorus trifluoride, wherein the solvent is at least one selected from the group consisting of acetonitrile, toluene, (THF)Tetrahydrofuran, NMP (N-methyl-2-pyrrolidone), and dimethylformamide (DMF).

5. In Paragraph 1, A method for preparing phosphorus trifluoride, the above-mentioned metal fluoride salt being a fluoride represented by the following chemical formula 1: [Chemical Formula 1] (M a ) n F m (In the above chemical formula 1, M a is an alkali metal or an alkaline earth metal, n and m are each independently 1 to 3, and said n and m are real numbers.) 6. In Paragraph 1, A method for producing phosphorus trifluoride, wherein the metal fluoride salt is at least one selected from the group consisting of sodium fluoride (NaF), potassium fluoride (KF), calcium fluoride (CaF2), and magnesium fluoride (MgF2).

7. In Paragraph 1, A method for producing phosphorus trifluoride, wherein the weight ratio of the phosphorus chloride compound and the metal fluoride salt is 1:1.5 to 1:

20.

8. In Paragraph 2, A method for preparing phosphorus trifluoride, wherein the weight ratio of the phosphorus chloride compound and the solvent is = 3:1 to 10:

1.

9. In Paragraph 1, The above phosphorus chloride compound is phosphorus trichloride, a method for manufacturing phosphorus trifluoride.

10. In Paragraph 1, A method for producing phosphorus trifluoride, further comprising a catalyst.

11. In Paragraph 10, A method for producing phosphorus trifluoride, wherein the catalyst is at least one selected from catalysts represented by the following chemical formula 2: [Chemical Formula 2] (M b ) x O m (In the above chemical formula 2, M b is at least one selected from Sb, Fe, Sn, Ti, and Al, and x is 1 or 2, and m is 1 to 3.) 12. In Paragraph 10, A method for producing phosphorus trifluoride, wherein the catalyst is at least one selected from the catalysts represented by the following chemical formula 3: [Chemical Formula 3] M C F l (In the above chemical formula 3, M C is at least one selected from Sb, Fe, Sn, Ti, and Al, and l is 3 or 4.) 13. In Paragraph 10, A method for producing phosphorus trifluoride, wherein the catalyst is at least one selected from the group consisting of diantimony trioxide (Sb2O3), antimony fluoride (SbF3), iron trioxide (Fe2O3), iron fluoride (FeF3), tin fluoride (SnF4), titanium fluoride (TiF4), and aluminum fluoride (AlF3).

14. In Paragraph 10, A method for producing phosphorus trifluoride, wherein the weight ratio of the solvent and the catalyst is = 1 : 0.1 to 1 : 0.0001.