JP2007327877A - Analysis method of polyvinyl chloride composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine and analyze a deterioration degree and a residual lifetime with sufficient sensitivity and accuracy, by a method simplified more than a general procedure for measuring directly properties (tensile elongation, tensile strength or the like) of an analysis object. <P>SOLUTION: In this analysis method wherein a PVC composition comprising at least polyvinyl chloride and a plasticizer is used as the analysis object, a tensile elongation change characteristic or a tensile strength change characteristic to a plasticizer content change is acquired beforehand (a master curve is acquired) by performing thermal accelerated deterioration treatment of a polyvinyl chloride composition comprising the polyvinyl chloride and the plasticizer which are the same as the analysis object, and the plasticizer content is calculated from the plasticizer extracted from the analysis object, and collated with the tensile elongation change characteristic or the tensile strength change characteristic, to thereby measure indirectly the tensile elongation or the tensile strength of the analysis object. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for analyzing a polyvinyl chloride composition, for example, a polyvinyl chloride composition used in various devices such as an oil-filled transformer, a dry mold transformer, a switchgear, a switchboard, and a rotating machine. It measures the physical properties and analyzes the degree of deterioration and remaining life.

  Various devices such as oil-filled transformers, dry mold transformers, switchgears, switchboards, rotating machines (electric equipment, etc .; hereinafter referred to as devices) have various polymer material compositions such as desired insulation and elasticity. , Stress resistance (mechanical strength, etc.), sealability, liquid resistance (resistance to electrolytes, organic chemical solutions (oil, etc.)), gas resistance (resistance to insulating gases, organic chemical gases, etc.), corrosion resistance Compositions having physical properties such as heat resistance, heat resistance, cold resistance, and weather resistance (resistance to rainwater, sunlight (ultraviolet rays, etc.), temperature / humidity changes, etc.) are appropriately used. Specific examples thereof include polyvinyl chloride, a phthalate diester plasticizer (for example, di-2-ethylhexyl phthalate (hereinafter referred to as DOP)) and the like, and are used as covering materials for electric wires and the like. Compositions (such as hollow (cylindrical) polyvinyl chloride compositions (hereinafter referred to as PVC compositions) used on the outer peripheral side of so-called polyvinyl chloride wires (hereinafter referred to as PVC wires), etc.) It is done.

  The polymer material composition deteriorates with time (for example, having a lifetime (for example, a lifetime of about 10 to 15 years)) depending on, for example, the content of components and the usage status (usage environment, usage frequency, etc.) of the device. However, since there is a risk that problems may occur in the device, research on the polymer material composition is being conducted as appropriate.

  For example, in the case of a PVC composition for a PVC electric wire, a plasticizer such as DOP having good compatibility is generally used. However, when an aromatic nucleus is present in the molecular structure of the plasticizer, sufficient It is said that the cold resistance cannot be obtained. Moreover, it is known that a crack etc. will generate | occur | produce in PVC composition itself depending on the use environment of a PVC electric wire. Furthermore, it is estimated that the molecular structure of the PVC composition changes over time (deterioration of polyvinyl chloride, plasticizers, changes in chlorine elimination reaction, volatilization, etc.), resulting in a decrease in insulation, elasticity, stress resistance, etc. It was.

  For this reason, maintenance such as periodic replacement or repair is performed in the polymer material composition. In recent years, a part of a polymer material composition (that is, an object to be analyzed) is periodically collected and directly measured for physical properties (for example, directly measured for physical properties of an object to be analyzed). Analysis (determining the degree of deterioration and remaining life) and performing maintenance in accordance with the analysis results, for example, to reduce running costs are being studied.

  For example, in the case of electric wires such as PVC electric wires, since the insulation property tends to decrease when the elasticity (tensile elongation, etc.) of the PVC composition decreases, a technique for directly measuring the elasticity of the analysis target is adopted. . In addition, paying attention to the fact that the insulation is significantly lowered when the tensile elongation rate is below the standard value of 150%, the degree of deterioration and the remaining life of the analyte are determined based on the tensile elongation rate and the standard value. A method of judging and analyzing is generally adopted. In addition, the said standard value is corresponded to the reference | standard based on the JIS standard (JISZ8301) aiming at the product reliability guarantee of electric wires.

  This general method is a method of directly measuring the tensile elongation rate or the like of the object to be analyzed, but it is considered that variations (for example, measurement errors depending on the test apparatus) are likely to occur. For this reason, for example, a PVC composition (analysis target) of a predetermined length (for example, 1.5 m long) is collected from the target PVC wire, and cut into multiple equal parts (for example, 10 parts) in the PVC composition. There is known a technique of performing processing operations such as removal of unnecessary core wires, obtaining an average value of tensile elongation rates of each processed object to be analyzed, and comparing the average value with a standard value.

  However, in the general method as described above, an excessive amount of an analysis target may be required for each analysis (excessive collection of the PVC composition). Further, in the above-mentioned large amount of objects to be analyzed, there is a risk that a great amount of work, time, etc., such as processing work such as removal of the core wire and direct measurement of the tensile elongation rate may be spent.

In addition, repeatedly apply a torsional force, determine the magnitude of the repulsive torque signal that results from it, and compare the torque value with a known torque value measured by a wire or cable with a known degradation state. Thus, there is known a technique for determining and evaluating the degree of deterioration in a non-destructive and simple and reliable manner in a live state.
7-52150

  As described above, it is simplified (for example, the amount of PVC composition to be collected and labor required for analysis), compared to a general method for directly measuring physical properties (tensile elongation, tensile strength, etc.) of an analysis target. Therefore, the advent of a method that can measure and analyze the physical properties with sufficient accuracy and contribute to the reduction of running costs related to maintenance, for example, has been desired.

  In order to solve the above-mentioned problems, the present invention is an analysis method that uses a PVC composition that is applied to various devices and contains a plasticizer (DOP or the like) as an object of analysis, and includes a plasticizer in the object of analysis. By measuring the rate, the physical properties of the object to be analyzed can be indirectly specified and analyzed with sufficient accuracy.

  Specifically, the invention according to claim 1 is an analysis method for subjecting a polyvinyl chloride composition comprising at least polyvinyl chloride and a plasticizer to be analyzed, wherein the polyvinyl chloride composition is thermally accelerated and deteriorated. Thus, the tensile elongation change characteristic with respect to the plasticizer content change is obtained in advance, and the plasticizer content calculated from the plasticizer extracted from the object to be analyzed is the tensile elongation change characteristic with respect to the plasticizer content change. And the tensile elongation of the object to be analyzed is indirectly measured.

  The invention according to claim 2 is an analysis method for analyzing a polyvinyl chloride composition comprising at least polyvinyl chloride and a plasticizer, and the plasticizer is obtained by subjecting the polyvinyl chloride composition to thermal accelerated deterioration treatment. Obtaining the tensile strength change characteristic with respect to the content rate change in advance, collating the plasticizer content calculated from the plasticizer extracted from the analysis target with the tensile strength change property with respect to the plasticizer content rate change, It is characterized by indirectly measuring the tensile strength of the object to be analyzed.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the acceleration time of the thermal accelerated deterioration treatment is converted into elapsed years according to the 10 ° C. half law, and the plasticizer content change characteristic with respect to the change in elapsed years Is obtained in advance, and the plasticizer content calculated from the plasticizer extracted from the analysis target is collated with the plasticizer content characteristics with respect to the aging, so that the age of the analysis target is indirectly determined. It is characterized by measuring.

  According to a fourth aspect of the present invention, in the first to third aspects of the present invention, the plasticizer is extracted by a Soxhlet extraction method.

  According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the plasticizer is a phthalic acid diester plasticizer.

  According to the first to fifth aspects of the invention, it is simplified (e.g., the amount of the PVC composition to be collected) than the general method of directly measuring the physical properties of the analysis target (tensile elongation, tensile strength, etc.) This is a method in which labor and time required for analysis are suppressed, and by measuring the content of the plasticizer in the analysis target (PVC composition), the physical properties of the analysis target are indirectly detected with sufficient accuracy. (For example, the degree of deterioration of physical properties can be specified).

  According to the invention described in claim 3, it is possible to indirectly specify the elapsed years of the analysis target with sufficient accuracy (for example, specify the remaining life).

  Hereinafter, the analysis method of the PVC composition in this Embodiment is demonstrated based on drawing etc. FIG.

  In this embodiment, in the PVC composition (analysis target) applied to various devices, the content of the plasticizer decreases with time, but the other polyvinyl chloride and the like hardly change, and the PVC There are specific correlation characteristics between the tensile elongation rate (tensile elongation rate, residual tensile elongation rate) of the composition, the tensile strength and the plasticizer content (for example, the tensile strength is increased by thermal accelerated deterioration treatment described later). Elongation rate characteristic line and tensile strength characteristic line (master curve) are obtained), which is a method for indirectly measuring and analyzing the physical properties of the PVC composition.

  That is, an analysis method using at least a PVC composition composed of polyvinyl chloride and a plasticizer as an object to be analyzed, and in the polyvinyl chloride composition comprising the same polyvinyl chloride and plasticizer as the object to be analyzed, heat accelerated deterioration treatment The tensile elongation change characteristic and tensile strength change characteristic with respect to the plasticizer content change are obtained in advance, and the plasticizer content is calculated from the plasticizer extracted from the subject to be analyzed. The tensile elongation rate and the tensile strength of the object to be analyzed are indirectly measured in comparison with the strength change characteristic.

  Next, after verifying various changes in the PVC composition with respect to the thermal accelerated deterioration treatment in verification examples 1 to 5 using various samples (analysis target), the tensile elongation of the PVC composition in accordance with examples 1 and 2 Specific examples of analytical methods that can indirectly measure the rate and tensile strength and determine the degree of deterioration and remaining life are shown.

  The tensile elongation and tensile strength described below are measured in accordance with the JIS standard C3005 rubber / plastic insulated wire test method, and the core wire is removed from a part of the PVC wire (opened in the longitudinal direction as necessary). The PVC composition that has been confirmed to have no core wire left) is used as a sample (a sample having a length of 150 mm), a marked line with an interval of 50 mm is attached to the center of the sample, and the tensile speed is set to 500 mm / min. went.

  The thermal accelerated deterioration treatment was performed by a method designed based on the 10 ° C. half law (Arrhenius law). Specifically, a constant temperature bath (“Hello Soyokaze” manufactured by Espec Corp.) is used, and a processing time (hereinafter referred to as acceleration time) and a processing temperature (hereinafter referred to as acceleration temperature) in the constant temperature bath are set. Was carried out by heating. The acceleration time and acceleration temperature are appropriately set based on the following formula (1) according to the degree of elapsed years to be accelerated (for example, acceleration corresponding to +10 years, +20 years, +30 years), for example, the rated temperature of the sample, etc. In consideration of the above, 90 ° C., which has a track record with the KIV line, was set to the center (90 ° C., 105 ° C., etc.). The greater the difference between the acceleration temperature and the reference temperature (eg, 20 ° C.), the faster the acceleration of the elapsed years, even when the acceleration temperature is set relatively low (eg, 70 ° C.). However, by setting the acceleration time to be long, for example, the same thermal acceleration deterioration process as that when the center is set at 90 ° C. can be performed.

  “Acceleration time (days)” = (“Elapsed years to be accelerated (years)” × 365 (days)) / (2 ^ ((“acceleration temperature” − “reference temperature”) / 10)) (1).

  Furthermore, the Soxhlet extraction method is used to measure the amount of plasticizer in a sample for the purpose of creating a tensile elongation characteristic line and a tensile strength characteristic line (master curve), which are criteria for judging the degree of deterioration and remaining life of the sample. Applied. In the measurement by this Soxhlet extraction method, a Soxhlet extraction system comprising a flask, eggplant flask, mantle heater, cooling device, temperature measuring instrument, etc. is used, and as shown in FIG. Through the extraction step S2, the cooling step S3, and the calculation step S4, the plasticizer content was measured. Specifically, in the eggplant flask constant weight step S1a, the eggplant flask is heated in a constant temperature bath (105 ° C.) (1 hour), cooled in a desiccator (30 minutes), and weighed (constant weight value ± 0.0005 g or less). Was repeated. In the pretreatment step S1b to be analyzed, a PVC composition sampled from a part (about 1 g) of the PVC electric wire and the core wire removed (cut in the longitudinal direction as necessary to confirm that the core wire does not remain) is used as a sample. The sample was cut into granules (about 0.3 mm in size), and about 1 g of the electric wire was collected, weighed to 1 g using a balance, and filled into a cylindrical filter paper. In the extraction step S2, boiling stone (glass) and diethyl ether (130 ml) are put into the flask, placed in a predetermined location of the cylindrical filter paper, and the temperature in the cooling pipe (13 ° C.) is confirmed. The sample was extracted while the mantle heater was turned on and the temperature in the flask (about 100 ° C.) was confirmed (continuous for 6 hours). In the cooling step S3, the extract in the flask is moved into the eggplant flask, the inner wall of the flask is washed with ethyl ether (three times), the solvent in the eggplant flask is removed by an evaporator, and then in a thermostatic chamber (80 ° C.). The eggplant flask was repeatedly heated (1 hour), cooled in the desiccator (30 minutes), and weighed (constant value ± 0.0005 g or less) to obtain a concentrated solution (extracted plasticizer). And in the calculation step, flask weight subtraction calculation (“the eggplant flask weight at the cooling step S3 (including the plasticizer) /“ the eggplant flask weight at the eggplant flask constant weight step S1a ”) × 100 = based on the plasticizer content (%) The plasticizer content was determined by performing calculation.

[Verification Example 1]
In this verification example 1, the change in the molecular structure of the PVC composition due to the thermal accelerated deterioration treatment was verified. First, a PVC composition sample S1 is obtained from an unused PVC electric wire (new 2cm ² KIV wire) applied to a general distribution board, and the core wire is removed, and the absorbance characteristics are measured by the FT-IR method. The results are shown in the spectral characteristic line L1a (without thermal accelerated deterioration treatment) in FIG. Further, by subjecting the sample S1 to thermal acceleration deterioration treatment, after deterioration of a predetermined acceleration time (acceleration time corresponding to about 15 years converted to 10 ° C. half law), the spectral characteristic line L Absorbance characteristics were measured in the same manner as in the case of _1a , and the results are shown in the spectral characteristic line L _1b (with thermal accelerated deterioration treatment) in FIG.

In the results shown in FIG. 2, when attention is paid to the absorbance decrease the degree of spectral characteristic line L _1b as compared to the spectral characteristic line L _1a, is relatively large decrease in peak of the wavelength from a plasticizer (1725 cm ^-1) However, it can be seen that there is almost no decrease in the peaks related to wavelengths derived from other components. In general, it is known that when a PVC composition itself is thermally accelerated and deteriorated, for example, a chlorine elimination reaction is caused in the PVC composition. From the spectral characteristic lines L _1a and L _1b shown in FIG. No change from the chlorine elimination reaction was observed.

  Therefore, in the PVC composition, it was confirmed that although the plasticizer content decreased by the heat accelerated deterioration treatment (in other words, with the passage of time (age)), the components such as PVC hardly decreased.

[Verification Example 2]
In this verification example 2, the change of the tensile elongation rate of the PVC composition and the change of the plasticizer content rate due to the thermal accelerated deterioration treatment were verified. First, in the sample S1 subjected to various acceleration time degradation by the thermal accelerated degradation treatment, the tensile elongation rate was measured and the plasticizer content rate was measured by the Soxhlet extraction method.

Then, by comparing the measured values with the initial values (tensile elongation rate and plasticizer content rate before thermal accelerated deterioration treatment), the tensile elongation residual rate and the plasticizer amount residual rate are calculated, respectively. The respective calculation results are shown in the tensile elongation residual rate change characteristic line L _{1c with} respect to the acceleration time in FIG. 3 and the plasticizer amount residual rate change characteristic line L _1d with respect to the acceleration time in FIG.

From the characteristic lines L _1c and L _1d shown in FIG. 3 and FIG. 4, it can be read that the tensile elongation residual ratio and the plasticizer amount residual ratio tend to decrease as the acceleration time of the thermal accelerated deterioration process increases. .

  Therefore, the PVC composition is between the acceleration time by the thermal accelerated deterioration treatment and the tensile elongation rate (tensile elongation rate, residual tensile elongation rate) and plasticizer content rate (residual amount of plasticizer) of the PVC composition. It was confirmed that there was a correlation characteristic of each specific tendency.

[Verification Example 3]
In this verification example 3, the change of the tensile elongation rate of various PVC compositions was verified. First, three kinds of unused PVC electric wires (new 2 cm ² KIV wires) applied to a general switchboard were prepared, and the core wires were removed to obtain PVC composition samples S2, S3, and S4. Thereafter, in the same manner as in Verification Example 2 above, in each of the samples S2 to S4 subjected to various acceleration time degradation by the thermal acceleration degradation treatment, measurement of the tensile elongation rate, measurement of the plasticizer content by the Soxhlet extraction method, respectively. Went.

Then, the tensile elongation residual rate is calculated by comparing the measured value of the tensile elongation rate with the initial value, and the calculated results are respectively shown in the tensile elongation residual rate change characteristic line L ₂ (sample S2 with respect to the acceleration time in FIG. 5). ), L ₃ (sample S3), L ₄ (sample S4). Further, the measured values of the tensile elongation rates of the samples S2, S3, and S4 are collectively shown as characteristic diagrams with respect to the plasticizer content rate change in FIG.

As shown in FIG. 5, the tensile elongation residual rate change characteristics with respect to the acceleration time in each of the samples S2 to S4 tend to decrease as the acceleration time by the thermal acceleration deterioration process increases, but the tendency (degree of decrease). Is different for each of the samples S2 to S4. On the other hand, from the results shown in FIG. 6, even if the samples S2 to S4 are of different types, the characteristic lines L _{2 to 4} (ie, plastic It can be read that it is represented by a master curve of the agent content and tensile elongation.

  Therefore, in the PVC composition, even if the types are different (the tensile elongation rate change characteristic with respect to the acceleration time by the thermal accelerated deterioration treatment is different), the tensile elongation rate (tensile elongation rate, tensile elongation) of the PVC composition is different. It was confirmed that there is a correlation characteristic having approximately the same tendency between the residual ratio) and the plasticizer content, and that this characteristic line can be applied as a master curve of the plasticizer content and the tensile elongation.

[Verification Example 4]
In this verification example 4, first, four types of unused PVC electric wires (new 2 mm ² KIV wires) that are applied to a general switchboard are prepared, and the core wires are removed to obtain PVC composition samples S5 and S6. , S7, S8 were obtained. Then, the measurement of the plasticizer content rate by the Soxhlet extraction method similar to the said verification example 2 was performed 3 times for every sample S5-S8. Then, an average value, a standard deviation, and a coefficient of variation were calculated from each of the measured values, and are shown in Table 1 below.

  In the results shown in Table 1 above, since the coefficient of variation in each sample S5 to S8 is relatively low (3.49 or less), when the Soxhlet extraction method is applied in the measurement of the plasticizer content of the PVC composition, It can be read that there is sufficient reproducibility.

[Verification Example 5]
In this verification example 5, first, an unused PVC electric wire (new 0.2 mm ² electronic wire wire cross-linked by electron irradiation) applied to a general switchboard is prepared, and the core wire is removed to prepare a PVC composition. Sample S9 was obtained. Then, the plasticizer content rate was measured three times by the same Soxhlet extraction method as in the above-mentioned verification example 4. Then, an average value, a standard deviation, and a coefficient of variation were calculated from each measured value, and are shown in Table 2 below.

  In the results shown in Table 2, similar to the results shown in Table 1, since the coefficient of variation is relatively low in the sample S9 (0.74), the Soxhlet extraction method is used in the measurement of the plasticizer content of the PVC composition. Is applied, it can be seen that even if the type of PVC composition is different, it has sufficient reproducibility.

[Example 1]
In Example 1, first, an unused PVC electric wire (new 2 mm ² KIV wire) applied to a general switchboard was prepared, and the core wire was removed to obtain a PVC composition sample S10. Thereafter, in the same manner as in the above-described verification example 3, in the sample S10 subjected to various acceleration time degradations by the thermal acceleration degradation treatment, the tensile elongation rate was measured and the plasticizer content rate was measured by the Soxhlet extraction method. .

Then, based on the tensile elongation characteristics and the plasticizer content characteristics with respect to the acceleration time measured as described above, the correlation characteristic between the plasticizer content and the tensile elongation characteristics is shown as a master curve MC ₁ in FIG. Indicated. Further, the acceleration time in terms of elapsed years by 10 ° C. half rule, shown in FIG. 8 the properties of the plasticizer content with respect to the number of years elapsed as a master curve MC _2.

In the master curve MC ₁ shown in FIG. 7, focusing on the standard value of 150% based on the JIS standard, it can be seen that the insulation of the sample S10 is remarkably low when the plasticizer content is 20 mass% or less. Further, wherein when the plasticizer content of 20 mass% is as, if matching master curve MC ₂ shown in FIG. 8, it can read the number of years elapsed sample S10 is of the order of 40 years.

  Therefore, by obtaining the master curve of the plasticizer content and the tensile elongation characteristics as described above, the tensile elongation is measured indirectly, for example, by simply measuring the plasticizer content to be analyzed. It was confirmed that the deterioration degree and the like can be judged and analyzed. In addition, when the master curve of the plasticizer content relative to the elapsed years was obtained, it was confirmed that the elapsed years of the analysis target were indirectly measured based on the plasticizer content, and the remaining life could be determined and analyzed. .

[Example 2]
In this example 2, as in the case of the example 1, in the sample S10 subjected to various acceleration time degradations by the thermal acceleration degradation process, the tensile strength measurement and the plasticizer content measurement by the Soxhlet extraction method are performed, respectively. Went.

Then, based on the tensile strength characteristics and the plasticizer content characteristics with respect to the acceleration time measured as described above, the correlation characteristics between the plasticizer content and the tensile strength characteristics are shown as a master curve MC ₃ in FIG. . Further, the acceleration time was converted into elapsed years according to the 10 ° C. half law, and the characteristics of the plasticizer content with respect to the elapsed years are shown in FIG. 10 as a master curve MC ₄ .

In the master curve MC ₃ shown in FIG. 9, when the tensile strength is 25 MPa or less, the plasticizer content is 20 mass% or less. With reference to the result of FIG. It can be seen that it is extremely low. Further, when the tensile strength is 25 MPa or less as described above, it can be read that the elapsed time is about 40 years as in the result of FIG. 8 of Example 1 when the master curve MC ₄ shown in FIG. 10 is collated. .

  Therefore, by obtaining the master curve of the plasticizer content and the tensile strength as described above, for example, by simply measuring the plasticizer content of the object to be analyzed, the tensile strength is indirectly measured and the degree of deterioration is determined. It was confirmed that it was possible to determine and analyze the above. Moreover, when the master curve of the tensile strength with respect to the elapsed years was obtained, it was confirmed that the elapsed years of the object to be analyzed were indirectly measured by the tensile strength, and the remaining life and the like could be determined and analyzed.

  Although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention. Such variations and modifications are naturally within the scope of the claims.

  For example, although the specific example regarding the PVC composition which contains di-2-ethylhexyl phthalate as a plasticizer was mentioned in the above-mentioned Example, the same effect | action also in the PVC composition which contains other phthalic acid diester type | system | groups as a plasticizer. It is clear that an effect can be obtained.

The schematic process drawing of the measurement by Soxhlet extraction method applicable to a present Example. FIG. 6 is an absorbance characteristic diagram for the thermal accelerated deterioration process in Verification Example 1. The tensile elongation residual rate change characteristic view with respect to the acceleration time in Verification Example 2. The plasticizer amount residual rate change characteristic view with respect to the acceleration time in Verification Example 2. FIG. 10 is a graph showing a change in tensile elongation remaining rate with respect to acceleration time in Verification Example 3. The tensile elongation rate change characteristic view with respect to the plasticizer content rate in Verification Example 3. Schematic which shows the master curve of the plasticizer content rate in Example 1, and a tensile elongation rate characteristic. The characteristic view which shows the master curve of the elapsed years in Example 1, and a plasticizer content rate. Schematic which shows the master curve of the plasticizer content rate and tensile strength characteristic in Example 2. FIG. The characteristic view which shows the master curve of the elapsed years in Example 2, and tensile strength.

Claims (5)

An analysis method for analyzing a polyvinyl chloride composition comprising at least polyvinyl chloride and a plasticizer,
By preliminarily obtaining a tensile elongation change characteristic with respect to a change in plasticizer content by subjecting the polyvinyl chloride composition to thermal accelerated deterioration treatment,
By comparing the plasticizer content calculated from the plasticizer extracted from the analyte with the tensile elongation change characteristic with respect to the plasticizer content change, the tensile elongation of the analyte is indirectly determined. A method for analyzing a vinyl chloride composition, comprising measuring. An analysis method for analyzing a polyvinyl chloride composition comprising at least polyvinyl chloride and a plasticizer,
By preliminarily obtaining a tensile strength change characteristic with respect to a change in plasticizer content by subjecting the polyvinyl chloride composition to thermal accelerated deterioration treatment,
The plasticizer content calculated from the plasticizer extracted from the analysis target is collated with the tensile strength change characteristic with respect to the plasticizer content change, and the tensile strength of the analysis target is indirectly measured. A method for analyzing a vinyl chloride composition. The acceleration time of the thermal accelerated deterioration treatment is converted to the elapsed years according to the 10 ° C. half law, and the plasticizer content change characteristic with respect to the elapsed years change is obtained in advance,
The plasticizer content calculated from the plasticizer extracted from the analysis target is collated with the plasticizer content characteristics with respect to the secular change, and the elapsed time of the analysis target is indirectly measured. The method for analyzing a vinyl chloride composition according to claim 1 or 2.   The method for analyzing a vinyl chloride composition according to any one of claims 1 to 3, wherein the plasticizer is extracted by a Soxhlet extraction method.   The method for analyzing a vinyl chloride composition according to any one of claims 1 to 4, wherein the plasticizer is a phthalic acid diester plasticizer.

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