Electronic fluorinated liquid moisture detection method

Abstract

The invention provides a method for detecting the moisture content in electronic fluorinated liquid, which comprises the following steps of: pretreating a sample by using an external extraction method, and measuring the moisture content in the electronic fluorinated liquid by using a Karl-Fischer coulomb method. The Karl Fischer reagent comprises the following components in percentage by mass: 50% of ethanol, 10% of diethanol amine, 10% of imidazole, 10% of methanol, 5% of sulfur dioxide, 5% of hydroiodic acid, 5% of hydrogen bromide and 5% of iodine, an external extraction method is required to pretreat a sample before moisture detection, and the water content m1 of the measured sample, the water content m2 of an extraction solvent, the weight x1 of the solvent and the weight x2 of the sample are recorded respectively; a correction formula is used for correction, and finally moisture measurement of the electronic fluorinated liquid is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of moisture detection methods for electronic fluorinated liquids, and particularly relates to a moisture detection method for electronic fluorinated liquids. Background Art

[0002] Electronic fluorinated fluids are specialized liquids used in electronic products. These fluids are primarily composed of fluorides, typically low-molecular-weight fluorinated compounds. They are colorless, odorless, transparent, low-viscosity, non-flammable, and chemically inert. Their primary components include hydrofluoroethers (HFEs), perfluoropolyethers (PFPEs), and hydrofluorocarbons (HFCs). They exhibit excellent chemical inertness, thermal conductivity, material compatibility, and electrical insulation properties. They are environmentally friendly, with an ODP (ozone depletion potential) of zero. They are commonly used in electronic testing fluids, cleaning agents, refrigerants, and desiccants. Their applications in semiconductors, precision electronics, aerospace, and medical fields reflect the chemical properties of fluorine and fully leverage its diverse market potential.

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

[0004] Because electronic fluoride solution is not miscible with Karl Fischer reagent, direct addition will cause stratification, preventing the water in the electronic fluoride solution from entering the anolyte in a timely manner, resulting in low measurement results. While the combined cassette furnace and Karl Fischer titrator method is suitable for samples that separate from water at higher temperatures, are poorly soluble, or react readily with the Karl Fischer reagent, this method heats the sample vial and transports the evaporated water using dry nitrogen to the sample cell of the moisture analyzer for detection. However, there are still some drawbacks to measuring 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 crystal water, resulting in low results; 2. At low ambient temperatures, water carried by the carrier gas can easily condense on the tube walls, resulting in low moisture measurements; 3. Setting the carrier gas flow rate too high can cause some water to escape without participating in the reaction, resulting in low test results.

[0005] The external extraction pretreatment method used in this paper can not only ensure that the water is evenly dispersed in the solution, but also obtain the water detection results more quickly. Compared with the Karl Fischer drying oven water measurement, it will not cause experimental errors and other measurement difficulties due to the carrier gas, and provide more accurate and reliable water content measurement results. Summary of the Invention

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

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions: a method for detecting moisture in electronic fluoride liquid, which uses an external extraction method to pretreat the sample, and uses the Karl Fischer coulometric method to measure the moisture content in the electronic fluoride liquid. The Karl Fischer reagent is composed of ethanol, diethanolamine, imidazole, methanol, sulfur dioxide, hydroiodic acid, hydrogen bromide, and iodine in mass fractions. Before detecting moisture, the sample needs to be pretreated by external extraction, and 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. The correction formula is used for correction, and finally the moisture determination of the electronic fluoride liquid is realized. The specific detection method is as follows: Step 1: Pour the extraction solvent into a vial, seal it, extract some of the extraction solvent, and measure the water content of the extraction solvent using the Karl Fischer Coulometry method. The measurement result is marked as x1. Step 2: Weigh a certain amount of extraction solvent, record the weight as m1, then pour the sample to be tested (i.e., electronic fluoride liquid) 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 of the extracted sample, and mark the measurement result as x2; Step 3: Use the formula to correct the above measured m1, m2, x1, and x2 to obtain an accurate moisture detection result of the electronic fluoride liquid.

[0008] The electronic fluorinated liquid includes tert-butyl fluoroalcohol, perfluorodecylethylene, perfluorobutylpentane, etc., and perfluorobutylpentane is selected in the embodiment of this article.

[0009] Before measuring moisture using the Karl Fischer coulometric method, fresh Karl Fischer reagent is added to the titration cell of the coulometric moisture meter to start pre-titration, waiting for the moisture in the Karl Fischer reagent to be removed and the instrument to reach a standby state.

[0010] In the above step 1, a syringe is used to inject the extract into the vial, that is, 1-2 ml of anhydrous extraction solvent is drawn into the syringe, and the syringe is shaken to eliminate moisture on the inner wall of the syringe and the syringe needle.

[0011] In the above steps, when a certain amount of extraction solvent or sample solution is taken for measurement, the operation is repeated three times to perform parallel tests.

[0012] The Karl Fischer reagent comprises, by mass fraction, 40-60% of ethanol, 5-15% of diethanolamine, 5-15% of imidazole, 5-15% of methanol, 1-5% of sulfur dioxide, 1-5% of hydroiodic acid, 1-5% of hydrogen bromide, and 1-5% of iodine.

[0013] In a preferred embodiment, 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.

[0014] The extraction solvent is chloroform or toluene. In the experiments of the present invention, it was found that chloroform can extract up to 350ppm and toluene can extract up to 600ppm. Since the electronic fluorine liquid has a low water content, chloroform is preferably used as the extraction solvent.

[0015] The moisture content is detected by the Coulometric method (KF); the maximum initial drift is 20-30 μg / min; the mixing time is 50-80 s; the electrode polarization current is 2-5 μA; the generating electrode current is 200-400 mA; the stirring speed is 1000-1500 rpm / min; the control endpoint is 80-120 mV; the control zone is 200-300 mV; and the termination drift value is 1-3 μg / min.

[0016] The moisture content is 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 end point: 100 mV; control zone: 250 mV; termination drift value: 3 μg / min.

[0017] The ratio of samples pretreated by external extraction method is: Sample volume: extraction solvent = 1:10-20, the preferred ratio is 1:10.

[0018] The correction formula is: ) x1: Water content of blank solvent (%, ppm) x2: Measure the water content of the sample (%, ppm) m1: weight of solvent (g) m2: weight of the sample (g).

[0019] The beneficial effects of the present invention are as follows: a suitable moisture detection pretreatment method is selected for the electronic fluorinated liquid, and the detection method is optimized, so that the moisture can be ensured to be evenly dispersed in the solution, and the moisture detection result can be obtained more quickly. Compared with the measurement of moisture in a Karl Fischer drying furnace, there will be no measurement difficulties such as experimental errors due to carrier gas, and more accurate and reliable moisture content measurement results are provided, with the variance preferably controlled within 2.3%, preferably within 1.5%, and further preferably within 1.0%. DETAILED DESCRIPTION

[0020] Example 1 Determination method using a combined furnace and Karl Fischer titrator Weigh approximately 1g of sample (accurate to 0.001g) into a vial, seal it with a septum, and place it in the appropriate position on the injector. Also, prepare an empty vial without sample, seal it with a septum, and place it in the "BLANK" position. Also, place another empty vial at the "zero" position on the injector for drift determination. When the set method is activated, the instrument first performs a drift determination. Upon completion, the instrument prompts you to enter the sample mass and then automatically runs the sequence to determine the water content of the sample. Operating conditions: temperature of the cassette furnace autosampler: 110 ℃ ± 1 ℃; heating time of the cassette furnace autosampler: 20 min; carrier gas flow rate: 40 mL / min; endpoint relative drift: 10 μg / min; extraction time: 5 min. Table 1 Moisture determination results using a combined oven and Karl Fischer titrator

[0021] External dissolution pretreatment determination method Step 1: Set the Karl Fischer titrator parameters as follows: Coulometric method (KF); Maximum initial drift: 25 μg / min; Mixing time: 60 s; Electrode polarization current: 5 μA; Generator electrode current: 200 mA; Stirring speed: 1500 rpm / min; Control endpoint: 100 mV; Control zone: 250 mV; End drift: 3 μg / min. Then, add 100 ml of fresh Karl Fischer reagent to the titration cell of the coulometric titrator and begin a pre-titration. Wait for the water in the KF reagent to be removed and the instrument to reach standby mode. 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 (all examples use this Karl Fischer reagent).

[0022] Step 2: Use a 10ml syringe to draw 1-2ml of anhydrous toluene solvent into the syringe, shake the syringe to eliminate the moisture on the inner wall of the syringe and the syringe needle, discard the extraction reagent used to rinse the syringe, and repeat the above operation three times; Step 3: Inject the extraction solvent into a vial sealed with a septum. At the same time, use a syringe to extract part of the extraction solvent and measure its water content. The measurement result is marked as x1.

[0023] Step 4: Weigh a certain amount of extraction solvent (m1) at a ratio of 1:10 (w / w). Pour perfluorobutylpentane into the bottle and seal it with a septum. The added weight is m2. Place the sample in an ultrasonic chamber to extract the water from the sample.

[0024] Step 5: Take a certain amount of sample solution for measurement. The measurement result of the sample is marked as x2. Repeat the above operation five times to perform parallel experiments.

[0025] Step 6: Use the following formula to correct the above-measured m1, m2, x1, and x2 to obtain an accurate moisture detection result of the electronic fluoride liquid.

[0026] ) x1: Water content of blank solvent (%, ppm) x2: Measure the water content of the sample (%, ppm) m1: weight of solvent (g) m2: weight of the sample (g).

[0027] Table 2 Moisture determination results

[0028] Table 3 Moisture determination results after corrected formula

[0029] Example 2 Step 1: Set the Karl Fischer titrator parameters as follows: Coulometric KF; Maximum Initial Drift: 25 μg / min; Mixing Time: 60 s; Electrode Polarization Current: 5 μA; Generator Current: 300 mA; Stirring Speed: 1500 rpm / min; Control Endpoint: 100 mV; Control Zone: 250 mV; End Drift: 3 μg / min. Then, add 100 ml of fresh Karl Fischer reagent to the titration cell of the coulometric titrator and begin a pre-titration. Wait for the water in the Karl Fischer reagent to be removed and for the instrument to reach standby mode. Step 2: Use a 10ml syringe to draw 1-2ml of anhydrous toluene solvent into the syringe, shake the syringe to eliminate the moisture on the inner wall of the syringe and the syringe needle, discard the extraction reagent used to rinse the syringe, and repeat the above operation three times; Step 3: Inject the extraction solvent into a vial sealed with a septum. At the same time, use a syringe to extract part of the extraction solvent and measure its water content. The measurement result is marked as x1.

[0030] Step 4: Weigh a certain amount of extraction solvent (m1) at a ratio of 1:10 (w / w). Pour perfluorobutylpentane into the bottle and seal it with a septum. The added weight is m2. Place the sample in an ultrasonic chamber to extract the water from the sample.

[0031] Step 5: Take a certain amount of sample solution for measurement. The measurement result of the sample is marked as x2. Repeat the above operation five times to perform parallel experiments.

[0032] Step 6: Use the following formula to correct the above-measured m1, m2, x1, and x2 to obtain an accurate moisture detection result of the electronic fluoride liquid.

[0033] ) x1: Water content of blank solvent (%, ppm) x2: Measure the water content of the sample (%, ppm) m1: weight of solvent (g) m2: weight of the sample (g).

[0034] Table 4 Moisture determination results

[0035] Table 5 Moisture determination results after corrected formula

[0036] Example 3 Step 1: Set the Karl Fischer titrator parameters as follows: Coulometric KF; Maximum Initial Drift: 25 μg / min; Mixing Time: 60 s; Electrode Polarization Current: 5 μA; Generator Current: 400 mA; Stirring Speed: 1500 rpm / min; Control Endpoint: 100 mV; Control Zone: 250 mV; End Drift: 3 μg / min. Then, add 100 ml of fresh Karl Fischer reagent to the titration cell of the coulometric titrator and begin a pre-titration. Wait for the water in the Karl Fischer reagent to be removed and the instrument to reach standby mode. Step 2: Use a 10ml syringe to draw 1-2ml of anhydrous toluene solvent into the syringe, shake the syringe to eliminate the moisture on the inner wall of the syringe and the syringe needle, discard the extraction reagent used to rinse the syringe, and repeat the above operation three times; Step 3: Inject the extraction solvent into a vial sealed with a septum. At the same time, use a syringe to extract part of the extraction solvent and measure its water content. The measurement result is marked as x1.

[0037] Step 4: Weigh a certain amount of extraction solvent (m1) at a ratio of 1:10 (w / w). Pour perfluorobutylpentane into the bottle and seal it with a septum. The added weight is m2. Place the sample in an ultrasonic chamber to extract the water from the sample.

[0038] Step 5: Take a certain amount of sample solution for measurement. The measurement result of the sample is marked as x2. Repeat the above operation five times to perform parallel experiments.

[0039] Step 6: Use the following formula to correct the above-measured m1, m2, x1, and x2 to obtain an accurate moisture detection result of the electronic fluoride liquid.

[0040] ) x1: Water content of blank solvent (%, ppm) x2: Measure the water content of the sample (%, ppm) m1: weight of solvent (g) m2: weight of the sample (g).

[0041] Table 6 Moisture determination results

[0042] Table 7 Moisture determination results after correcting the formula

[0043] Example 4 Step 1: Set the Karl Fischer titrator parameters as follows: Coulometric KF; Maximum Initial Drift: 25 μg / min; Mixing Time: 60 s; Electrode Polarization Current: 5 μA; Generator Current: 300 mA; Stirring Speed: 1500 rpm / min; Control Endpoint: 100 mV; Control Zone: 250 mV; End Drift: 3 μg / min. Then, add 100 ml of fresh Karl Fischer reagent to the titration cell of the coulometric titrator and begin a pre-titration. Wait for the water in the Karl Fischer reagent to be removed and for the instrument to reach standby mode. Step 2: Use a 10ml syringe to draw 1-2ml of anhydrous chloroform solvent into the syringe, shake the syringe to eliminate the moisture on the inner wall of the syringe and the syringe needle, discard the extraction reagent used to rinse the syringe, and repeat the above operation three times; Step 3: Inject the extraction solvent into a vial sealed with a septum. At the same time, use a syringe to extract part of the extraction solvent and measure its water content. The measurement result is marked as x1.

[0044] Step 4: Weigh a certain amount of extraction solvent (m1) at a ratio of 1:10 (w / w). Pour perfluorobutylpentane into the bottle and seal it with a septum. The added weight is m2. Place the sample in an ultrasonic chamber to extract the water from the sample.

[0045] Step 5: Take a certain amount of sample solution for measurement. The measurement result of the sample is marked as x2. Repeat the above operation five times to perform parallel experiments.

[0046] Step 6: Use the following formula to correct the above-measured m1, m2, x1, and x2 to obtain an accurate moisture detection result of the electronic fluoride liquid.

[0047] ) x1: Water content of blank solvent (%, ppm) x2: Measure the water content of the sample (%, ppm) m1: weight of solvent (g) m2: weight of the sample (g).

[0048] Table 8 Moisture determination results

[0049] Table 9 Moisture determination results after corrected formula

[0050] Example 5 Step 1: Set the Karl Fischer titrator parameters as follows: Coulometric KF; Maximum Initial Drift: 25 μg / min; Mixing Time: 60 s; Electrode Polarization Current: 5 μA; Generator Current: 300 mA; Stirring Speed: 1500 rpm / min; Control Endpoint: 100 mV; Control Zone: 250 mV; End Drift: 3 μg / min. Then, add 100 ml of fresh Karl Fischer reagent to the titration cell of the coulometric titrator and begin a pre-titration. Wait for the water in the Karl Fischer reagent to be removed and for the instrument to reach standby mode. Step 2: Use a 10ml syringe to draw 1-2ml of anhydrous toluene solvent into the syringe, shake the syringe to eliminate the moisture on the inner wall of the syringe and the syringe needle, discard the extraction reagent used to rinse the syringe, and repeat the above operation three times; Step 3: Inject the extraction solvent into a vial sealed with a septum. At the same time, use a syringe to extract part of the extraction solvent and measure its water content. The measurement result is marked as x1.

[0051] Step 4: Weigh a certain amount of extraction solvent (m1) at a ratio of 1:20 (w / w). Pour perfluorobutylpentane into the bottle and seal it with a septum. The added weight is m2. Place the sample in an ultrasonic chamber to extract the water from the sample.

[0052] Step 5: Take a certain amount of sample solution for measurement. The measurement result of the sample is marked as x2. Repeat the above operation five times to perform parallel experiments.

[0053] Step 6: Use the following formula to correct the above-measured m1, m2, x1, and x2 to obtain an accurate moisture detection result of the electronic fluoride liquid.

[0054] ) x1: Water content of blank solvent (%, ppm) x2: Measure the water content of the sample (%, ppm) m1: weight of solvent (g) m2: weight of the sample (g).

[0055] Table 8 Moisture determination results

[0056] Table 9 Moisture determination results after corrected formula

[0057] The external extraction pretreatment method for measuring moisture in electronic fluoride liquid showed more accurate results than the combined cassette furnace and Karl Fischer titrator method, completely releasing water from the sample. While the results were slightly higher than those obtained with the combined cassette furnace and Karl Fischer titrator, they were closer to the true value. By varying the electrode polarization current and generator electrode current parameters of the Karl Fischer titrator, the optimal parameters for the measured moisture content were determined to be 5μA (electrode polarization current) and 300mA (generator electrode current), resulting in the same water content as 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 fluoride liquid, with a 1:10 ratio of anhydrous toluene being the optimal addition. Therefore, anhydrous toluene was selected as the extraction solvent.

[0058] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The embodiments and features in the embodiments of this application may be arbitrarily combined with each other unless they conflict. The scope of protection of the present invention shall be the technical solutions described in the claims, including equivalent alternatives to the technical features of the technical solutions described in the claims. Equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for detecting moisture in electronic fluorinated liquid, characterized in that: The detection method is as follows: Step 1: Pour the extraction solvent into a vial, seal it, extract some of the extraction solvent, and measure the water content of the extraction solvent using the Karl Fischer Coulometry method. The measurement result is marked as x1. 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 of the extracted sample, and mark the measurement result as x2; Step 3: Use the formula to correct the above measured m1, m2, x1, and x2 to obtain an accurate moisture detection result of the electronic fluoride liquid.

2. The method for detecting moisture in an electronic fluorinated liquid according to claim 1, wherein: The electronic fluorinated liquid includes any one of tert-fluorobutanol, perfluorodecylethylene, and perfluorobutylpentane.

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

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

5. The method for detecting moisture in electronic fluorinated liquid according to claim 1, wherein: Before measuring using the Karl Fischer coulometric method, fresh Karl Fischer reagent is added to the titration cell of the coulometric titrator to start pre-titration, waiting for the water in the Karl Fischer reagent to be removed and the instrument to reach the standby state.

6. The method for detecting moisture in electronic fluorinated liquid according to claim 1, wherein: The extraction solvent is chloroform or toluene.

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

8. The method for detecting moisture in electronic fluorinated liquid according to claim 7, wherein: The moisture content was detected by the Coulometric KF method; the maximum initial drift was 25 μg / min; the mixing time was 60 s; the electrode polarization current was 5 μA; the generating electrode current was 300 mA; the stirring speed was 1500 rpm / min; and the control endpoint was 100 mV. Control area: 250mV; termination drift value: 3μg / min.

9. The method for detecting moisture in electronic fluorinated liquid according to claim 1, wherein: The ratio of the sample pretreated by the external extraction method is the sample to be tested: extraction solvent = 1:10-20 (w / w); preferably 1:10 (w / w).

10. The method for detecting moisture in electronic fluorinated liquid according to claim 1, wherein: The correction formula is: ) x1: Water content of blank solvent (%, ppm) x2: Measure the water content of the sample (%, ppm) m1: weight of solvent (g) m2: weight of the sample (g).

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