An electronic fluorination liquid water detection method

Abstract

The application provides a detection method for water content in electronic fluorination liquid, which uses external extraction method to pretreat the sample, adopts Karl Fischer coulometric method to measure the water content in the electronic fluorination liquid, and the Karl Fischer reagent is composed of 50% ethanol, 10% diethanolamine, 10% imidazole, 10% methanol, 5% sulfur dioxide, 5% hydroiodic acid, 5% hydrogen bromide, 5% iodine in mass fraction, and the sample needs to be pretreated by the external extraction method before the water content is detected; the water content m1 of the measured sample, the water content m2 of the extraction solvent, the weight x1 of the solvent and the weight x2 of the sample are recorded respectively, correction is conducted by using a correction formula, and finally the water content in the electronic fluorination liquid is determined.

Description

Technical Field

[0001] This invention belongs to the technical field of moisture detection methods for electronic fluorinated liquids, and specifically relates to a method for detecting moisture in electronic fluorinated liquids. Background Technology

[0002] Electronic fluorinated fluids are fluorinated fluids used in electronic products. They are special liquids with fluorides as the main component, usually composed of low molecular weight fluorinated compounds. They are colorless, odorless, transparent, low in viscosity, non-flammable, and chemically inert. Their main components include hydrofluoroethers (HFE), perfluoropolyethers (PFPE), and hydrofluorocarbons (HFCs). Electronic fluorinated fluids possess excellent chemical inertness, thermal conductivity, material compatibility, and electrical insulation properties. They are environmentally friendly, with an ODP (ozone depletion potential) value of 0. They are commonly used in electronic testing fluids, cleaning agents, refrigerants, and desiccants. Their applications in semiconductors, precision electronic equipment, aerospace, and medical fields reflect the chemical properties of fluorine and fully utilize its diverse application markets.

[0003] Excessive moisture in electronic fluorinated solutions can cause the following problems: 1. Moisture reacts with fluoride ions (such as F⁻), reducing their activity; 2. Increased moisture content significantly improves conductivity, affecting the dielectric strength and other properties of the electronic fluorinated solution; 3. The presence of moisture may disrupt the homogeneity of the fluorinated solution, creating localized areas of thermal resistance and affecting its heat transfer efficiency; 4. Moisture is a major cause of metal corrosion, and excessive moisture can lead to corrosion of metal components in equipment using electronic fluorinated solutions. Therefore, during use, the moisture concentration is generally required to be below 50 ppm.

[0004] Because electronic fluorinated liquids are immiscible with Karl Fischer reagents, direct addition will cause stratification, preventing moisture in the electronic fluorinated liquid from entering the anolyte in time, leading to lower measurement results. Although the combined Karl Fischer furnace-Karl Fischer moisture analyzer method is suitable for samples that separate from water at higher temperatures, are poorly soluble, or readily react with Karl Fischer reagents, this method involves heating the sample vial and using dry nitrogen to transport the evaporated moisture to the moisture analyzer's sample cell for detection. However, it still has some drawbacks when detecting sample moisture: 1. For high-boiling-point or large-molecule samples (such as asphalt and polymers), even high-temperature heating may not completely release bound water or water of crystallization, leading to lower results; 2. When the ambient temperature is low, the moisture carried away by the carrier gas easily condenses on the tube wall, leading to lower moisture measurements; 3. Setting the carrier gas flow rate too high may cause some moisture to escape without participating in the reaction, resulting in lower detection results.

[0005] The external extraction pretreatment method used in this paper not only ensures that the water is uniformly dispersed in the solution, but also obtains the water content detection results more quickly. Compared with the Karl Fischer drying oven method, it avoids the experimental errors caused by the carrier gas, providing more accurate and reliable water content determination results. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for detecting the moisture content of electronic fluorinated liquids.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a method for detecting moisture in electronic fluorinated liquids. This method uses an external extraction method to pretreat the sample and employs the Karl Fischer coulometric method to measure the moisture content in the electronic fluorinated liquid. The Karl Fischer reagent consists of ethanol, diethanolamine, imidazole, methanol, sulfur dioxide, hydroiodic acid, hydrogen bromide, and iodine by mass fraction. Before detecting moisture, the sample needs to be pretreated by external extraction. The water content m1 of the measured sample, the water content m2 of the extraction solvent, the weight x1 of the solvent, and the weight x2 of the sample are recorded. A correction formula is used for correction, ultimately achieving the determination of moisture in the electronic fluorinated liquid. The specific detection method is as follows:

[0008] Step 1: Inject the extraction solvent into a vial, seal it, extract a portion of the extraction solvent, and measure the water content of the extraction solvent using the Karl Fischer coulometric method. The measurement result is marked as x1.

[0009] Step 2: Weigh a certain amount of extraction solvent, record the weight as m1, then pour the sample to be tested (i.e., electronic fluorinated liquid) into the bottle, seal it, and record the weight as m2; after ultrasonic extraction, use the Karl Fischer coulomb method to measure the water content in the extracted sample, and mark the measurement result as x2;

[0010] Step 3: Correct the measured m1, m2, x1, and x2 using the formula to obtain an accurate result for the moisture content of the electronic fluorinated liquid.

[0011] The electronic fluorinated liquid includes fluorotert-butanol, perfluorodecylethylene, perfluorobutylpentane, etc., and perfluorobutylpentane is selected in the examples in this article.

[0012] Before measuring moisture using the Karl Fischer coulometric method, fresh Karl Fischer reagent is added to the titration cell of the coulometric moisture analyzer to begin pre-titering. The instrument then waits for the moisture in the Karl Fischer reagent to be removed and reaches standby mode.

[0013] In step one above, a syringe is used to inject 1-2 ml of anhydrous extraction solvent into the vial. The syringe is then shaken to remove moisture from the inner wall of the syringe and the syringe needle.

[0014] In the above steps, when taking a certain amount of extraction solvent or sample solution for measurement, the operation should be repeated three times to perform parallel experiments.

[0015] The Karl Fischer reagent comprises 40-60% ethanol, 5-15% diethanolamine, 5-15% imidazole, 5-15% methanol, 1-5% sulfur dioxide, 1-5% hydroiodic acid, 1-5% hydrogen bromide, and 1-5% iodine.

[0016] In a preferred embodiment, the Karl Fischer reagent comprises 50% ethanol, 10% diethanolamine, 10% imidazole, 10% methanol, 5% sulfur dioxide, 5% hydroiodic acid, 5% hydrogen bromide, and 5% iodine.

[0017] The extraction solvent is chloroform or toluene. In the experiments of this invention, it was found that chloroform can extract a maximum of 350 ppm, while toluene can extract a maximum of 600 ppm. Since the electronic fluorinated liquid has a low water content, chloroform is preferred as the extraction solvent.

[0018] The moisture content was detected by coulometric KF method; maximum initial drift: 20-30 μg / min; mixing time: 50-80 s; electrode polarization current: 2-5 μA; generating electrode current: 200-400 mA; stirring speed: 1000-1500 rpm / min; control endpoint: 80-120 mV; control zone: 200-300 mV; termination drift value: 1-3 μg / min.

[0019] The moisture content was detected by coulometric KF method; maximum initial drift: 25 μg / min; mixing time: 60 s; electrode polarization current: 5 μA; generating electrode current: 200-400 mA; stirring speed: 1500 rpm / min; control endpoint: 100 mV; control zone: 250 mV; termination drift value: 3 μg / min.

[0020] The proportion of samples pretreated by external extraction is:

[0021] Sample volume: extraction solvent = 1:10-20, with the preferred ratio being 1:10.

[0022] The corrected formula is:

[0023] )

[0024] x1: Water content (%, ppm) of the blank solvent

[0025] x2: Measure the water content (%, ppm) of the sample.

[0026] m1: Weight of solvent (g)

[0027] m2: The weight of the sample (g).

[0028] The beneficial effects of this invention are: a suitable pretreatment method for moisture detection has been selected for electronic fluorinated liquids, and the detection method has been optimized, which can ensure that moisture is uniformly dispersed in the solution and obtain moisture detection results quickly. Compared with the Karl Fischer drying furnace measurement of moisture, it does not have the experimental error and other measurement problems caused by the carrier gas, and provides more accurate and reliable moisture content measurement results. The variance is preferably controlled within 2.3%, preferably within 1.5%, and even more preferably within 1.0%. Detailed Implementation

[0029] Example 1

[0030] Determination method using a combined cassette burner and Karl Fischer moisture analyzer

[0031] Weigh approximately 1g of sample (accurate to 0.001g) into a sample vial, seal the vial with a diaphragm, and place the vial in the corresponding position on the injector. Simultaneously, prepare an empty sample vial, seal it with a diaphragm, and place it in the "BLANK" position. Additionally, place another empty sample vial in the "zero" position on the injector for drift measurement. To start the instrument, it will first perform a drift measurement. After completion, the instrument will prompt you to input the sample mass and then automatically run the sequence to obtain the water content in the sample.

[0032] Operating conditions: Autosampler temperature: 110 ℃±1 ℃; Autosampler heating time: 20 min; Carrier gas flow rate: 40 mL / min; Endpoint relative drift: 10 μg / min; Extraction time: 5 min.

[0033] Table 1. Moisture determination results using a combined cassette burner and Karl Fischer moisture analyzer.

[0034]

[0035] External dissolution pretreatment determination method

[0036] Step 1: Set the Karl Fischer moisture analyzer parameters as follows: Coulometric method (KF); maximum initial drift: 25 μg / min; mixing time: 60 s; electrode polarization current: 5 μA; generating electrode current: 200 mA; stirring speed: 1500 rpm / min; control endpoint: 100 mV; control range: 250 mV; termination drift value: 3 μg / min. Then, add 100 ml of fresh Karl Fischer reagent to the titration cell of the coulometric moisture analyzer and begin pre-titering. Wait for the moisture in the Karl Fischer reagent to be removed, and for the instrument to reach standby mode.

[0037] The Karl Fischer reagent is composed of 50% ethanol, 10% diethanolamine, 10% imidazole, 10% methanol, 5% sulfur dioxide, 5% hydroiodic acid, 5% hydrogen bromide, and 5% iodine (this Karl Fischer reagent was used in all examples).

[0038] Step 2: Draw 1-2 ml of anhydrous toluene solvent into a 10 ml syringe and inject it into the syringe. Shake the syringe to remove moisture from the inner wall of the syringe and the syringe needle. Discard the extraction reagent used to rinse the syringe. Repeat the above operation three times.

[0039] Step 3: Inject the extraction solvent into a small vial sealed with a diaphragm, and at the same time use a syringe to draw out a portion of the extraction solvent and measure its water content. The measurement result is marked as x1.

[0040] Step 4: Weigh a certain amount of extraction solvent, denoted as m1, with an extraction solvent ratio of 1:10 (w / w). Then pour perfluorobutylpentane into the bottle and seal it with a diaphragm. The added weight is denoted as m2. Place the sample in an ultrasonic chamber to extract the water from the sample.

[0041] Step 5: Take a certain amount of sample solution and measure it. Mark the measurement result of the sample as x2. Repeat the above operation five times to make parallel experiments.

[0042] Step Six: Correct the measured m1, m2, x1, and x2 using the following formula to obtain an accurate result for the moisture content of the electronic fluorinated liquid.

[0043] )

[0044] x1: Water content (%, ppm) of the blank solvent

[0045] x2: Measure the water content (%, ppm) of the sample.

[0046] m1: Weight of solvent (g)

[0047] m2: The weight of the sample (g).

[0048] Table 2 Moisture content determination results

[0049]

[0050] Table 3. Moisture determination results after formula correction

[0051]

[0052] Example 2

[0053] Step 1: Set the Karl Fischer moisture analyzer parameters as follows: Coulometric method (KF); maximum initial drift: 25 μg / min; mixing time: 60 s; electrode polarization current: 5 μA; generating electrode current: 300 mA; stirring speed: 1500 rpm / min; control endpoint: 100 mV; control range: 250 mV; termination drift value: 3 μg / min. Then, add 100 ml of fresh Karl Fischer reagent to the titration cell of the coulometric moisture analyzer and begin pre-titering. Wait for the moisture in the Karl Fischer reagent to be removed, and for the instrument to reach standby mode.

[0054] Step 2: Draw 1-2 ml of anhydrous toluene solvent into a 10 ml syringe and inject it into the syringe. Shake the syringe to remove moisture from the inner wall of the syringe and the syringe needle. Discard the extraction reagent used to rinse the syringe. Repeat the above operation three times.

[0055] Step 3: Inject the extraction solvent into a small vial sealed with a diaphragm, and at the same time use a syringe to draw out a portion of the extraction solvent and measure its water content. The measurement result is marked as x1.

[0056] Step 4: Weigh a certain amount of extraction solvent, denoted as m1, with an extraction solvent ratio of 1:10 (w / w). Then pour perfluorobutylpentane into the bottle and seal it with a diaphragm. The added weight is denoted as m2. Place the sample in an ultrasonic chamber to extract the water from the sample.

[0057] Step 5: Take a certain amount of sample solution and measure it. Mark the measurement result of the sample as x2. Repeat the above operation five times to make parallel experiments.

[0058] Step Six: Correct the measured m1, m2, x1, and x2 using the following formula to obtain an accurate result for the moisture content of the electronic fluorinated liquid.

[0059] )

[0060] x1: Water content (%, ppm) of the blank solvent

[0061] x2: Measure the water content (%, ppm) of the sample.

[0062] m1: Weight of solvent (g)

[0063] m2: The weight of the sample (g).

[0064] Table 4 Moisture content determination results

[0065]

[0066] Table 5. Moisture determination results after formula correction

[0067]

[0068] Example 3

[0069] Step 1: Set the Karl Fischer moisture analyzer parameters as follows: Coulometric method (KF); maximum initial drift: 25 μg / min; mixing time: 60 s; electrode polarization current: 5 μA; generating electrode current: 400 mA; stirring speed: 1500 rpm / min; control endpoint: 100 mV; control range: 250 mV; termination drift value: 3 μg / min. Then, add 100 ml of fresh Karl Fischer reagent to the titration cell of the coulometric moisture analyzer and begin pre-titering. Wait for the moisture in the Karl Fischer reagent to be removed, and for the instrument to reach standby mode.

[0070] Step 2: Draw 1-2 ml of anhydrous toluene solvent into a 10 ml syringe and inject it into the syringe. Shake the syringe to remove moisture from the inner wall of the syringe and the syringe needle. Discard the extraction reagent used to rinse the syringe. Repeat the above operation three times.

[0071] Step 3: Inject the extraction solvent into a small vial sealed with a diaphragm, and at the same time use a syringe to draw out a portion of the extraction solvent and measure its water content. The measurement result is marked as x1.

[0072] Step 4: Weigh a certain amount of extraction solvent, denoted as m1, with an extraction solvent ratio of 1:10 (w / w). Then pour perfluorobutylpentane into the bottle and seal it with a diaphragm. The added weight is denoted as m2. Place the sample in an ultrasonic chamber to extract the water from the sample.

[0073] Step 5: Take a certain amount of sample solution and measure it. Mark the measurement result of the sample as x2. Repeat the above operation five times to make parallel experiments.

[0074] Step Six: Correct the measured m1, m2, x1, and x2 using the following formula to obtain an accurate result for the moisture content of the electronic fluorinated liquid.

[0075] )

[0076] x1: Water content (%, ppm) of the blank solvent

[0077] x2: Measure the water content (%, ppm) of the sample.

[0078] m1: Weight of solvent (g)

[0079] m2: The weight of the sample (g).

[0080] Table 6 Moisture content determination results

[0081]

[0082] Table 7. Moisture determination results after the modified formula.

[0083]

[0084] Example 4

[0085] Step 1: Set the Karl Fischer moisture analyzer parameters as follows: Coulometric method (KF); maximum initial drift: 25 μg / min; mixing time: 60 s; electrode polarization current: 5 μA; generating electrode current: 300 mA; stirring speed: 1500 rpm / min; control endpoint: 100 mV; control range: 250 mV; termination drift value: 3 μg / min. Then, add 100 ml of fresh Karl Fischer reagent to the titration cell of the coulometric moisture analyzer and begin pre-titering. Wait for the moisture in the Karl Fischer reagent to be removed, and for the instrument to reach standby mode.

[0086] Step 2: Use a 10ml syringe to draw 1-2ml of anhydrous chloroform solvent and inject it into the syringe. Shake the syringe to remove moisture from the inner wall of the syringe and the syringe needle. Discard the extraction reagent used to rinse the syringe. Repeat the above operation three times.

[0087] Step 3: Inject the extraction solvent into a small vial sealed with a diaphragm, and at the same time use a syringe to draw out a portion of the extraction solvent and measure its water content. The measurement result is marked as x1.

[0088] Step 4: Weigh a certain amount of extraction solvent, denoted as m1, with an extraction solvent ratio of 1:10 (w / w). Then pour perfluorobutylpentane into the bottle and seal it with a diaphragm. The added weight is denoted as m2. Place the sample in an ultrasonic chamber to extract the water from the sample.

[0089] Step 5: Take a certain amount of sample solution and measure it. Mark the measurement result of the sample as x2. Repeat the above operation five times to make parallel experiments.

[0090] Step Six: Correct the measured m1, m2, x1, and x2 using the following formula to obtain an accurate result for the moisture content of the electronic fluorinated liquid.

[0091] )

[0092] x1: Water content (%, ppm) of the blank solvent

[0093] x2: Measure the water content (%, ppm) of the sample.

[0094] m1: Weight of solvent (g)

[0095] m2: The weight of the sample (g).

[0096] Table 8 Moisture content determination results

[0097]

[0098] Table 9. Moisture determination results after formula correction

[0099]

[0100] Example 5

[0101] Step 1: Set the Karl Fischer moisture analyzer parameters as follows: Coulometric method (KF); maximum initial drift: 25 μg / min; mixing time: 60 s; electrode polarization current: 5 μA; generating electrode current: 300 mA; stirring speed: 1500 rpm / min; control endpoint: 100 mV; control range: 250 mV; termination drift value: 3 μg / min. Then, add 100 ml of fresh Karl Fischer reagent to the titration cell of the coulometric moisture analyzer and begin pre-titering. Wait for the moisture in the Karl Fischer reagent to be removed, and for the instrument to reach standby mode.

[0102] Step 2: Draw 1-2 ml of anhydrous toluene solvent into a 10 ml syringe and inject it into the syringe. Shake the syringe to remove moisture from the inner wall of the syringe and the syringe needle. Discard the extraction reagent used to rinse the syringe. Repeat the above operation three times.

[0103] Step 3: Inject the extraction solvent into a small vial sealed with a diaphragm, and at the same time use a syringe to draw out a portion of the extraction solvent and measure its water content. The measurement result is marked as x1.

[0104] Step 4: Weigh a certain amount of extraction solvent, denoted as m1, with an extraction solvent ratio of 1:20 (w / w). Then pour perfluorobutylpentane into the bottle and seal it with a diaphragm. The added weight is denoted as m2. Place the sample in an ultrasonic chamber to extract the water from the sample.

[0105] Step 5: Take a certain amount of sample solution and measure it. Mark the measurement result of the sample as x2. Repeat the above operation five times to make parallel experiments.

[0106] Step Six: Correct the measured m1, m2, x1, and x2 using the following formula to obtain an accurate result for the moisture content of the electronic fluorinated liquid.

[0107] )

[0108] x1: Water content (%, ppm) of the blank solvent

[0109] x2: Measure the water content (%, ppm) of the sample.

[0110] m1: Weight of solvent (g)

[0111] m2: The weight of the sample (g).

[0112] Table 8 Moisture content determination results

[0113]

[0114] Table 9. Moisture determination results after formula correction

[0115]

[0116] The external extraction pretreatment method for measuring the moisture content of electronic fluorinated liquids showed better accuracy compared to the combined method using a cassette furnace-Karl Fischer moisture analyzer, as it completely released water from the sample. While the measured value was slightly higher than that obtained using the combined cassette furnace-Karl Fischer method, it was closer to the true value. By adjusting the electrode polarization current and generating electrode current parameters of the Karl Fischer moisture analyzer, the optimal parameters were determined to be an electrode polarization current of 5 μA and a generating electrode current of 300 mA, resulting in a moisture content that matched the true value. By varying the type and ratio of the extraction solvent, anhydrous toluene was found to be more effective than anhydrous chloroform in extracting moisture from the electronic fluorinated liquids, with an optimal ratio of 1:10 for anhydrous toluene. Therefore, anhydrous toluene was selected as the extraction solvent.

[0117] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The embodiments and features described in these embodiments can be arbitrarily combined without conflict. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for detecting the moisture content of an electronic fluorinated liquid, characterized in that, The detection method is as follows: Step 1: Inject the extraction solvent into a vial, seal it, extract a portion of the extraction solvent, and measure the water content of the extraction solvent using the Karl Fischer coulometric method. The measurement result is marked as x1. The extraction solvent is chloroform or toluene. Step 2: Weigh a certain amount of extraction solvent, record the weight as m1, then pour the sample to be tested into the bottle, seal it, and record the weight as m2; after ultrasonic extraction, use the Karl Fischer coulometric method to measure the water content in the extracted sample, and mark the measurement result as x2; Step 3: Correct the measured m1, m2, x1, and x2 using the formula to obtain an accurate result for the moisture content of the electronic fluorinated liquid; The corrected formula is: ) x1: Water content (%, ppm) of the blank solvent x2: Measure the water content (%, ppm) of the sample. m1: Weight of solvent (g) m2: The weight of the sample (g).

2. The method for detecting moisture in an electronic fluorinated liquid according to claim 1, characterized in that: The electronic fluorinated liquid includes any one of fluorotert-butanol, perfluorodecylethylene, and perfluorobutylpentane.

3. The method for detecting moisture in an electronic fluorinated liquid according to claim 2, characterized in that: The Karl Fischer reagent comprises 40-60% ethanol, 5-15% diethanolamine, 5-15% imidazole, 5-15% methanol, 1-5% sulfur dioxide, 1-5% hydroiodic acid, 1-5% hydrogen bromide, and 1-5% iodine.

4. The method for detecting moisture in an electronic fluorinated liquid according to claim 3, characterized in that: The Karl Fischer reagent is composed of 50% ethanol, 10% diethanolamine, 10% imidazole, 10% methanol, 5% sulfur dioxide, 5% hydroiodic acid, 5% hydrogen bromide, and 5% iodine by mass fraction.

5. The method for detecting moisture in an electronic fluorinated liquid according to claim 1, characterized in that: Before using the Karl Fischer coulometric method for measurement, fresh Karl Fischer reagent is added to the titration cell of the coulometric moisture analyzer to begin pre-titration. The instrument is then allowed to reach standby mode after the water in the Karl Fischer reagent has been removed.

6. The method for detecting moisture in an electronic fluorinated liquid according to claim 1, characterized in that: The moisture content was detected by coulometric KF method; maximum initial drift: 20-30 μg / min; mixing time: 50-80 s; electrode polarization current: 2-5 μA; generating electrode current: 200-400 mA; stirring speed: 1000-1500 rpm / min; control endpoint: 80-120 mV; control zone: 200-300 mV; termination drift value: 1-3 μg / min.

7. The method for detecting moisture in an electronic fluorinated liquid according to claim 6, characterized in that: The moisture content was detected by coulometric KF method; maximum initial drift: 25 μg / min; mixing time: 60 s; electrode polarization current: 5 μA; generating electrode current: 300 mA; stirring speed: 1500 rpm / min; control endpoint: 100 mV. Control range: 250mV; Termination drift value: 3μg / min.

8. The method for detecting moisture in an electronic fluorinated liquid according to claim 1, characterized in that: The ratio of sample pretreatment by external extraction is 1:10-20 (w / w) between the sample to the extraction solvent.

9. The method for detecting moisture in an electronic fluorinated liquid according to claim 8, characterized in that: Extraction solvent = 1:10 (w / w).

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