JP2010243225A - Method for diagnosing deterioration of insulating material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To diagnose the degree of deterioration of an insulating material in a short time by taking a very small amount of a sample. <P>SOLUTION: The insulating material used in an electronic device or the like is measured by a pyrolytic GC-MS method and the degree of deterioration of the insulating material is diagnosed on the basis of the measured peaks of a total ion chromatogram (TIC). The peak increased by the deterioration of the insulating material in the peak of TIC serves as a deterioration peak and the peak not depending on the deterioration of the insulating material among the peaks of TIC serves as a fundamental peak. A peak area ratio is calculated by dividing the area of the deterioration peak by the area of the fundamental peak and a correlation between the peak area ratio and a physical tensile strength value is taken to diagnose the degree of deterioration of the insulating material. If an actually used insulating material is periodically sampled out when the correlation between the peak area ratio and the tensile strength value is taken, a more precise master curve is formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a deterioration diagnosis technique for insulating materials used in electrical equipment. The present invention relates to a technique for measuring a peak area that increases due to deterioration of an insulating material by a pyrolysis GC-MS method and diagnosing the degree of deterioration of the insulating material based on the peak area.

  At present, a binding band made of polyamide resin is used to collectively support and fix wiring of electric devices and the like. This binding band is used indoors and outdoors, and when it is used outdoors for a long period of time, it deteriorates with time due to the irradiation of ultraviolet rays and cannot support wiring or the like.

  When the cable tie cannot support the wiring, an abnormal load may be applied to the terminal portion of the wiring and the wiring may be cut off. Therefore, the state of the wiring is managed by regular visual inspection. Moreover, the quality control of the binding band is measured by a loop tensile strength test (Electrical Equipment Association Standard “Synthetic Resin Bundling Band for Wiring” IEIEJ-P-0001 (2005), JESC-E0017 (2005) standard product). The new standard value is managed as an index.

  As a method for diagnosing deterioration of insulating materials of electrical equipment, a correlation between a conventionally used diagnostic method (for example, a method for measuring a weight reduction rate) and a new diagnostic method (for example, a TG-DTA method) is taken, and the correlation Based on the above, there is a technique for performing a deterioration diagnosis of an insulating material by a new diagnosis method (for example, Patent Document 1).

JP 2005-338045 A

  However, physical tests such as the loop tensile strength test have problems such as variations in test results, the need for many test samples, and labor and time. Moreover, it is virtually impossible to manage the state of the binding band by frequently collecting the binding band and measuring the tensile strength.

  Therefore, it is required to sample a small amount of sample from the binding band, diagnose the deterioration and predict the life, but there is no such technique at present. Accordingly, an object of the present invention is to provide a method for accurately diagnosing the degree of deterioration of an insulating material (for example, a binding band) by collecting a small amount of sample.

  The insulating material deterioration diagnosis method of the present invention that achieves the above object is a method of measuring an insulating material by a pyrolysis GC-MS method and diagnosing the degree of deterioration of the insulating material based on a peak of a total ion chromatogram obtained by the measurement. The peak that increases due to the deterioration of the insulating material among the peaks is a deterioration peak, the peak that does not depend on the deterioration of the insulating material is the basic peak, and the area of the deterioration peak is the area of the basic peak. The deterioration degree of the insulating material is diagnosed based on the divided peak area ratio.

  Therefore, according to the above invention, it is possible to accurately diagnose the deterioration degree of the insulating material in a short time by collecting a very small amount of sample.

(A) TIC (total ion chromatogram) detected by measuring a polyamide resin by a pyrolysis GC-MS method, (b) TIC detected by measuring a polyamide resin by a pyrolysis GC-MS method ( Enlarged view). (A) Mass spectrum of degradation peak (peak detected at about 21 minutes in TIC obtained from measurement by pyrolysis GC-MS method), (b) Standard database (2-Cyclopen-1-one, 2-methyl) Mass spectrum of -3-pentyl-). (A) Mass spectrum of basic peak (peak detected at about 3 minutes in TIC obtained from measurement by pyrolysis GC-MS method), (b) Mass spectrum of standard database (Cyclopentane). The relationship figure of ultraviolet irradiation time and a peak area ratio. The correlation figure of a peak area ratio and a loop tensile strength value.

  In the present invention, deterioration determination of a polyamide-based resin used in an electronic device or the like is performed using a pyrolysis gas chromatograph mass spectrometer (Pyrolysis-Gas Chromatography-Mass Spectrometry, hereinafter abbreviated as a pyrolysis GC-MS apparatus).

  The principle of the pyrolysis GC-MS method is that a sample such as a polymer material is heated at a constant temperature rise rate in a heating furnace in an inert gas atmosphere, and a gas desorbed from the sample is introduced into the mass spectrometer. is there. As for the generated gas, an organic substance that is the generated gas is converted into an ion state by an electron impact ionization method (EI method), and the mass is distributed in the quadrupole rod and the mass is detected by a photomultiplier tube. Degradation is determined by the EGA-MS method using this pyrolysis GC-MS apparatus.

  As a method for determining the degree of deterioration, a polyamide resin having a different degree of deterioration is measured by a pyrolysis GC-MS method, a decomposition product is separated, a total ion chromatogram (hereinafter abbreviated as TIC) is measured, and a decomposition product is generated. Identify the thing.

  When measuring by the pyrolysis GC-MS method, about 50 μg of the sample is weighed into the measurement sample cup and measured. However, it is very difficult to take a constant μg order and weigh it into the measurement sample cup.

  Therefore, in the TIC obtained from the measurement by the pyrolysis GC-MS method, a peak whose peak intensity increases with deterioration is defined as a degradation peak, and a peak that does not depend on degradation is defined as a reference peak. The peak area ratio is calculated by dividing the deterioration peak area based on the deterioration peak by the reference peak area based on the reference peak.

  In other words, if the sampling weight is constant, when the ultraviolet irradiation time is changed, the deterioration peak area value increases as the ultraviolet irradiation time becomes longer. On the other hand, since the basic peak has a correlation with the sample weight, if the sample weight is constant, the basic peak area does not change even if the ultraviolet irradiation time is changed. Therefore, by comparing each sample with the peak area ratio calculated by dividing the degradation peak area by the basic peak area, the sample collection weight can be corrected, so that a measurement result independent of the sample weight can be obtained. it can.

  First, in order to obtain a master curve serving as a reference for deterioration diagnosis, a polyamide resin is irradiated with ultraviolet rays to create a sample that is artificially deteriorated. For example, UV exposure times of 0h, 500h, 1000h, and 2000h are used as simulated samples.

  The ultraviolet exposure sample is measured by a pyrolysis GC-MS method, the peak area ratio is calculated, and the relationship between the ultraviolet exposure time and the peak area ratio is calculated.

  On the other hand, a loop tensile strength test is performed on the UV-exposed sample, and the value at which the tensile strength is half the initial value (50%) is defined as the life point.

  Then, by creating a master curve that is a correlation between the measurement result of the pyrolysis GC-MS method and the test result of the loop tensile strength test, the polyamide resin as the evaluation target sample is measured by the pyrolysis GC-MS method. In addition, it is possible to diagnose deterioration of the sample to be evaluated based on the calculated peak area ratio and the master curve.

  FIG. 1 (a) and FIG. 1 (b) show the TIC detected by measuring a polyamide-based resin (ultraviolet light exposure time 0h, 500h, 1000h, 2000h) by the pyrolysis GC-MS method. FIG. 1B is an enlarged view of FIG.

The measurement apparatus and measurement conditions used for the measurement by the pyrolysis GC-MS method are shown.
Measuring device / gas chromatograph mass spectrometer (Shimadzu Corporation)
GC-MS equipment (Gas Chromatography-Mass Spectrometer)
QP-2010 [Data processing software: GC-MS solution Ver. 2.20]
・ Pyrolysis device (Frontier Lab Co., Ltd.)
D-SP (Double-Shot Pyrolzer) apparatus PY-2020iD type measurement condition gas chromatograph (GC)
-Column oven temperature: 300 ° C, vaporization chamber temperature: 330 ° C
-Ion source temperature: 200 ° C, injection mode: split-Total flow rate: 50 ml / min, column flow rate: 0.65 ml / min
-Linear velocity: 32.1 cm / sec, purge flow rate: 3 ml / min
Split ratio: 71.5 to 1.0
Detector / detection mode: EI (Electron Impact), detector voltage: 0.1 kV
Mass detection / measurement mode: scan, measurement time [start to end]: 0.1 min to 28 min
Mass range: 35 m / z to 500 m / z, measurement interval: 0.5 sec
・ Scanning speed: 1000
EGA
・ Temperature range: 600 ° C
As is apparent from the portion surrounded by the dotted line in the TIC shown in FIG. 1B, a peak (peak detected at about 21 minutes, hereinafter referred to as a degradation peak) where the peak intensity increases as the ultraviolet exposure time increases is observed. It could be confirmed. FIG. 2A shows the result of mass spectrum measurement for the peak component.

  When searching and identifying the components of the degradation peak based on the standard database, they were very similar to 2-Cyclopen-1-one and 2-methyl-3pentyl- shown in FIG.

  In the TIC shown in FIG. 1A, a portion surrounded by a dotted line (a peak detected at about 3 minutes) was selected as a reference peak. FIG. 3A shows the result of mass spectrum measurement for the peak component.

  When searching and identifying the components of the reference peak based on the standard database, it was very similar to the Cyclopentane shown in FIG.

  Generally, in the pyrolysis GC-MS method, the type of polyamide resin can be identified. For example, when Cyclopentanone is detected, it is determined that it is nylon 6 and 6, and when Caprolactam is detected, it is determined that it is nylon 6.

  Table 1 shows deterioration peaks, reference peaks, and peak area ratios when polyamide resins (ultraviolet exposure times 0 h, 500 h, 1000 h, 2000 h) were measured by the pyrolysis GC-MS method. And the master curve obtained by plotting ultraviolet exposure time and peak area ratio is shown in FIG.

  On the other hand, the relationship between the ultraviolet exposure time and the loop tensile strength value was obtained, and the correlation between the peak area ratio and the loop tensile strength value was obtained. The relationship between the peak area ratio and the loop tensile strength value is shown in FIG.

  Since the loop tensile strength value of the binding band when the UV exposure time was 0 h was 179.3 N, the lifetime region was set to about 90 N or less, which is a value obtained by halving the loop tensile strength value. By subtracting, the lifetime region in the peak area ratio is set.

  Therefore, if a master curve as shown in FIG. 5 is created, the peak area ratio of the binding band actually used can be calculated, and the degree of deterioration and the remaining life can be measured.

  As described above, according to the method for diagnosing deterioration of an insulating material according to the present invention, the degree of deterioration can be diagnosed with a very small amount (about 50 μg) of a sample by using the pyrolysis GC-MS method.

  In addition, if the binding band placed in the actual environment is measured by pyrolysis GC-MS method and loop tensile strength, a master curve showing the correlation between the obtained peak area ratio and loop tensile strength value should be prepared. Therefore, it is possible to accurately perform the deterioration diagnosis and the remaining life estimation of the binding band.

  As described above, if the pyrolysis GC-MS method is used, the degree of deterioration can be evaluated in a short time, and therefore, it can be applied to the quality control of the binding band.

  The insulation material deterioration diagnosis method of the present invention is not limited to the contents described in the embodiment, the measurement method and measurement conditions can be set as appropriate, and the data correlated with the peak area ratio is also the loop tensile strength. A conventionally used method (for example, bending strength, mass reduction rate measurement) may be used without being limited to the above. In particular, the insulating material is not limited to a polyamide-based resin, and any insulating material having a degradation peak can be applied as appropriate.

Claims (5)

In a method of measuring an insulating material by a pyrolysis GC-MS method and diagnosing the degree of deterioration of the insulating material based on a peak of a total ion chromatogram obtained by the measurement,
Among the peaks, a peak that increases due to deterioration of the insulating material is a deterioration peak,
The peak that does not depend on the deterioration of the insulating material among the peaks is a basic peak,
A method for diagnosing deterioration of an insulating material, wherein the deterioration degree of the insulating material is diagnosed based on a peak area ratio obtained by dividing the area of the deterioration peak by the area of the basic peak. The insulation material deterioration diagnosis method according to claim 1, wherein the deterioration degree of the insulating material is diagnosed by correlating the peak area ratio with a result of a physical tensile strength test. The insulating material is a polyamide resin,
The insulation material deterioration diagnosis method according to claim 1 or 2, wherein the type of the polyamide resin is specified based on the basic peak. The insulation material deterioration diagnosis method according to claim 3, wherein the polyamide resin is a binding band of wiring. Periodically collect the binding band,
5. The insulation material deterioration diagnosis method according to claim 4, wherein a correlation between the peak area ratio and a result of a physical tensile strength test is taken for each of the collected samples.

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