Film Deterioration Diagnosis Method

Abstract

To provide a novel method for diagnosing a film for degradation which allows a more efficient and more secure determination of a degraded state of the film based on resin.SOLUTION: The present invention relates to a method for diagnosing a film based on resin for degradation to achieve the object, the method using an analysis technique B as a non-destructive method as described below: the analysis technique B is a technique of confirming the presence or absence of acid anhydride and a sign of a hydrolysis reaction in the film by Fourier transform infrared spectroscopy analysis.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for diagnosing deterioration of film, and more particularly to a method for diagnosing deterioration of resin-based archival film. [Background technology]

[0002] Resin-based archival film (hereinafter simply referred to as "resin film") has traditionally been used to record and preserve various historical materials and documents in the form of "cinematograph film," "microfilm," "photographic film," "magnetic recording film," etc. Among resins, film using triacetate cellulose (TAC) as its base material (hereinafter referred to as "TAC film") is particularly flame-resistant compared to the nitrocellulose film used in the past, and has been called a safety film and touted as being capable of preserving data for over 100 years.

[0003] However, in recent years, it has become clear that under normal storage conditions, a phenomenon known as vinegar syndrome occurs, and even when TAC film is used, degradation begins after approximately 30 years. When TAC film is stored in a high-temperature, high-humidity environment, the temperature and humidity can cause TAC hydrolysis. The acetic acid gas generated during TAC hydrolysis acts as a catalyst, accelerating the TAC hydrolysis reaction. Vinegar syndrome refers to this rapid film degradation caused by TAC hydrolysis.

[0004] When TAC film deteriorates due to factors other than the vinegar syndrome phenomenon mentioned above, such as oxidation, leaching of plasticizers, or cracks in the image-generating layer, there is a risk of losing the information recorded on the TAC film. Therefore, various methods have been used to diagnose the deterioration of resin films, including TAC.

[0005] For example, Non-Patent Document 1 describes a method using a paper strip impregnated with bromocresol green sodium salt. That is, in the method described in Non-Patent Document 1, the paper strip is placed in a film storage can together with a TAC film, and the presence or absence of acetic acid gas inside the storage can is detected based on the color change of the paper strip after a certain period of time has passed.

[0006] Patent Document 1 also describes a method using a glass detector tube filled with inorganic particles coated with sodium metasilicate and cresol red. That is, the method described in Patent Document 1 determines the concentration of acetic acid gas from the amount of color change of the particles inside the glass detector tube when gas present around a film storage can is passed through the glass detector tube.

[0007] Furthermore, Non-Patent Document 2 describes that as the deterioration of a TAC film progresses, the water content in the TAC film increases and the pH on the surface of the TAC film decreases. That is, the method described in Non-Patent Document 2 checks the water content in the TAC film or checks the presence or absence of acetic acid attached to the TAC film by measuring pH.

[0008] Furthermore, Non-Patent Document 3 describes that when a TAC film plasticized with diethyl phthalate is subjected to accelerated aging, the decrease in the plasticizer content in the TAC film can be confirmed by thermogravimetric differential thermal analysis (hereinafter referred to as "TG-DTA") and Fourier transform infrared spectroscopy (hereinafter referred to as "FT-IR") analysis. That is, the method described in Non-Patent Document 3 confirms the thermal stability of the TAC film by TG-DTA analysis, or confirms the presence or absence of acid anhydride and signs of hydrolysis by FT-IR analysis.

[0009] Furthermore, Non-Patent Document 4 describes that when a TAC film that has deteriorated over time is analyzed in a room temperature environment, a phthalate ester-based plasticizer is eluted onto the surface of the TAC film, and then hydrolyzed and detected as white crystals. That is, the method described in Non-Patent Document 4 confirms the presence or absence of white crystals eluted onto the surface of the TAC film.

[0010] Furthermore, Non-Patent Document 5 describes that the plasticizer contained in a TAC film can be analyzed by pyrolysis gas chromatography / mass spectrometry (hereinafter referred to as "Py-GC / MS") or solvent extraction, and the deterioration state of the film can be estimated based on the residual plasticizer components. That is, the method described in Non-Patent Document 5 confirms the type of plasticizer in a TAC film by Py-GC / MS analysis. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application No. 2009-257838 [Non-patent literature]

[0012] [Non-Patent Document 1] E. Fran▲c▼ais, “The Safe and Accurate Way to Check Film for Vinegar Syndrome”, Image Permanence Institute, Rochester, NY (2001). [Non-patent document 2] NS Allen, M. Edge, JH Appleyard, TS Jewitt, CV Horie, D. Francis, “Acid-catalysed degradation of historic cellulose triacetate, cinematographic film: Influence of various film parameters”, Eur. Polym. J., 24(8), 707-712, (1988). [Non-patent document 3] E. Richardson, MT Giachet, M. Schilling, T. Learner, “Assessing the physical stability of archival cellulose acetate films by monitoring plasticizer loss”, Polym. Degrad. Stabil., 107, 231-236 (2014). [Non-patent document 4] Keiko Takahashi, Dai Hayakawa, Tomohiro Okamoto, Shoji Fujiwara, and Jin Yajima, "Analysis of White Solids Precipitated from Deteriorated Cinema Films - Chemical Verification of Vinegar Syndrome (1)," Bulletin of the Faculty of Engineering, Tokyo Polytechnic University, 36(1), 27-33 (2013). [Non-Patent Document 5] MT Giachet, M. Schilling, K. McCormick, J. Mazurek, E. Richardson, H. Khanjian, T. Learner, “Assessment of the composition and condition of animation cels made from cellulose acetate”, Polym. Degrad. Stabil., 107, 223-230 (2014). Summary of the Invention [Problem to be solved by the invention]

[0013] However, while the methods described in Non-Patent Document 1 and Patent Document 1 enable simple and low-cost detection of acetic acid gas, they make it difficult to accurately determine whether acetic acid gas has been generated from TAC film because acetic acid gas may be mixed into the film storage can from the external environment. Furthermore, the methods described in Non-Patent Document 1 and Patent Document 1 make it difficult to accurately detect signs of film deterioration other than vinegar syndrome, such as oxidation reactions, plasticizer elution, and cracking in the image-receiving layer. Furthermore, the AD Strips described in Non-Patent Document 1 and the detector tube described in Patent Document 1 can only determine the acetic acid gas concentration approximately based on color changes.

[0014] Furthermore, the methods described in Non-Patent Documents 2 and 3 involve forcibly accelerating the degradation of TAC films under high temperature and humidity conditions, but the reactions that occur during this process are not necessarily identical to the reactions that occur during aging at room temperature in an actual storage site. Therefore, the methods described in Non-Patent Documents 2 and 3 may be evaluating a state of degradation that differs from the state of degradation in an actual storage site.

[0015] Furthermore, the methods described in Non-Patent Document 4 and Non-Patent Document 5 have the problem that they do not provide clear indicators for determining and diagnosing the state of deterioration.

[0016] In view of the above, an object of the present invention is to provide a new film deterioration diagnosis method that can grasp the deterioration state of a resin film more efficiently and reliably than conventional methods. [Means for solving the problem]

[0017] As a result of extensive research, the present inventors have achieved the above object by employing the following film deterioration diagnosis method.

[0018] The film deterioration diagnosis method according to the present invention is a method for diagnosing deterioration of a resin film, and is characterized by using the following analysis method A and / or analysis method B, which are non-destructive analysis methods. Analysis method A: Check for any abnormalities in the resin film by visual observation and olfactory testing Analysis method B: Fourier transform infrared spectroscopy is used to check for the presence of acid anhydrides in the resin film and for signs of hydrolysis.

[0019] Furthermore, in the film deterioration diagnosis method according to the present invention, it is preferable to use the analysis method A and / or the analysis method B, followed by the analysis method C and / or the analysis method D shown below, which are non-destructive analysis methods. Analysis method C: Check for the presence or absence of acetic acid attached to the resin film by pH measurement Analysis method D: Confirm the concentration of acetic acid gas released from the film by high performance liquid chromatography (hereinafter referred to as "HPLC") analysis.

[0020] Furthermore, it is more preferable that the film deterioration diagnosis method of the present invention uses the non-destructive analysis method, and then uses one or a combination of two or more of the following destructive analysis methods, Analysis Methods E to H. Analysis Method E: Check the moisture content in the resin film using a Karl Fischer (hereinafter referred to as "KF") moisture meter. Analysis method F: Confirm the thermal stability of the resin film by thermogravimetric differential thermal analysis Analysis method G: Identify the plasticizer species in the resin film by pyrolysis gas chromatography mass spectrometry Analysis method H: Check the mechanical strength of the resin film by tensile testing

[0021] Furthermore, in the film deterioration diagnosis method according to the present invention, the resin film is preferably a cellulose triacetate film. [Effects of the Invention]

[0022] According to the present invention, the deterioration state of a resin film can be grasped more efficiently and reliably than conventionally. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 10 is a diagram showing an FT-IR spectrum obtained by analysis method B according to the present embodiment. [Figure 2] FIG. 10 is a diagram showing the peak intensity ratio of the FT-IR spectrum obtained by analysis method B according to the present embodiment. [Figure 3] FIG. 10 is a diagram showing the pH measurement results obtained by analysis method C according to the present embodiment. [Figure 4] FIG. 10 is a diagram showing the acetic acid gas concentration inside a film storage canister determined by HPLC measurement using analysis method D according to the present embodiment. [Figure 5] FIG. 10 is a diagram showing the results of moisture content measurement by analysis method E according to the present embodiment. [Figure 6] FIG. 10 is a diagram showing the results of TG curve measurement using analysis method F according to the present embodiment. [Figure 7] FIG. 10 is a diagram showing the thermal decomposition peak temperatures in analysis method F according to the present embodiment. [Figure 8] FIG. 10 is a diagram showing the results of Py-GC / MS measurement (undegraded film A) using analysis method G according to the present embodiment. [Figure 9] FIG. 10 is a diagram showing the results of Py-GC / MS measurement (undegraded film B) using analysis method G according to the present embodiment. [Figure 10] FIG. 10 is a diagram showing the results of Py-GC / MS measurement (undegraded C film) using analysis method G according to the present embodiment. [Figure 11] FIG. 10 is a diagram showing the results of Py-GC / MS measurement (film A without odor) using analysis method G according to the present embodiment. [Figure 12] FIG. 10 is a diagram showing the results of Py-GC / MS measurement (odorless film B) using analysis method G according to the present embodiment. [Figure 13] FIG. 10 is a diagram showing the results of Py-GC / MS measurement (odorless C film) using analysis method G according to the present embodiment. [Figure 14] FIG. 10 is a diagram showing the results of Py-GC / MS measurement (film A with odor) using analysis method G according to the present embodiment. [Figure 15] FIG. 10 is a diagram showing the results of Py-GC / MS measurement (film B having an odor) using analysis method G according to the present embodiment. [Figure 16] FIG. 10 is a diagram showing stress values ​​at film breakage obtained from a tensile test using analysis method H according to the present embodiment. [Figure 17] 1 is a chart showing an outline of a film deterioration diagnosis method according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the film deterioration diagnosis method according to the present invention will be described.

[0025] The film deterioration diagnosis method according to the present invention is a method for diagnosing deterioration of a resin film, and is characterized by using the following analysis method A and / or analysis method B, which are non-destructive analysis methods. Analysis method A: Check for any abnormalities in the film through visual observation and olfactory testing Analysis Method B: Fourier transform infrared spectroscopy (FT-IR) analysis is used to check the film for the presence of acid anhydrides and signs of hydrolysis.

[0026] The film deterioration diagnosis method of the present invention uses at least one non-destructive analysis method, namely, analysis method A and analysis method B. If film deterioration can be sufficiently confirmed by analysis method A or analysis method B, there is no need to perform analysis methods C to G described below. Therefore, analysis method A and / or analysis method B are essential analysis methods in the film deterioration diagnosis method of the present invention. Analysis method A and analysis method B will be described below.

[0027] (A) Analysis Method A Analysis Method A uses visual observation and olfactory testing to check for any abnormalities in the resin film, allowing for a simple assessment of the state of deterioration of the resin film. Visual observation involves checking for the presence of plasticizer elution and mold growth on the film surface. Significant deterioration of a resin film can lead to plasticizer elution and mold growth, which can be easily detected visually. Olfactory testing involves sampling the air inside a container in which the resin film is stored and using a person's sense of smell to check for any abnormalities. For example, when TAC film deteriorates, the TAC releases acetic acid gas through a hydrolysis reaction. This acetic acid generates an acetic acid odor inside the film storage container. Thus, the occurrence of an abnormal odor detectable by humans inside the film storage container can indicate significant deterioration of the resin film.

[0028] (B) Analysis Method B Analysis Method B uses FT-IR analysis to check for the presence or absence of acid anhydrides in resin films and signs of hydrolysis, making it possible to determine the deterioration state of resin films even when no abnormalities are detected in the olfactory test of Analysis Method A. For example, even if no acetic acid odor is detected in TAC films, hydrolysis may be progressing and plasticizers may be precipitation or decomposition may be occurring. A film deterioration diagnosis method using Analysis Method B will be described in detail below with reference to an embodiment.

[0029] In the analysis method B according to the present embodiment, an FT-IR Nicolet iS50 manufactured by Thermo Fisher Scientific Co., Ltd. was used as the apparatus. The measurement conditions were a resolution of 4 cm -1 , the number of accumulations is 32, and the measurement wave number range is 500 cm -1 From 4000cm -1 The automatic atmospheric correction was turned on, and a diamond crystal was used. The base side of the TAC film was measured using attenuated total reflectance (ATR). The resulting spectrum was then corrected for ATR using an angle of incidence of 45°, one reflection, and a refractive index of 1.5.

[0030] The TAC films used in the analysis method B according to the present embodiment were undegraded and degraded films. The undegraded films were prepared by visual and olfactory inspection using the analysis method A, and showed no signs of degradation (undegraded films A to C (developed after 2010)). The degraded films were prepared by visual and olfactory inspection using the analysis method A, and showed no signs of degradation (odorless films A to C (developed in April 1958)). The degraded films were prepared by visual and olfactory inspection using the analysis method A, and showed signs of degradation (odorful films A and B (developed in December 1958)).

[0031] Figure 1 shows the FT-IR spectra for three films: undegraded A, odorless A, and odorous A. Table 1 below shows the assignments of the main peaks in the FT-IR spectra obtained from Figure 1.

[0032] [Table 1]

[0033] As shown in Figure 1 and Table 1, in the odorless and odorous films A and A, the peak due to acid anhydride C=O was observed at a wavenumber of 1790 cm -1 From 1850cm -1 The peaks derived from acid anhydride C=O were observed because acetic anhydride was formed by dehydration condensation of acetic acid molecules, and phthalate esters contained as plasticizers were eluted onto the film surface to form phthalic anhydride. For undegraded film A, no peaks derived from acid anhydride C=O were observed, suggesting that no acetic acid gas was generated or plasticizers were eluted. In this way, the presence or absence of peaks derived from acid anhydrides can be used as one indicator of film degradation for TAC film.

[0034] Figure 2 also shows the peak intensity ratios of the FT-IR spectra for eight films: undegraded A to C, odorless A to C, and odorous A and B. This peak intensity ratio is the value obtained by dividing the peak intensity derived from OH groups by the peak intensity derived from CH groups for each TAC film, specifically, the peak intensity at a wavenumber of 3480 cm -1 The peak intensity at wavenumber 1370 cm -1 The error bars in the figure indicate the standard error of the peak intensity ratio. Figure 2 shows that the peak intensity ratio increases in the order of undegraded film, odorless film, and odorous film. This result indicates that as the hydrolysis reaction of TAC progresses, the peak intensity derived from OH groups increases, and bonds derived from acetyl groups in TAC (e.g., CH3 groups, C=O groups, CO - Therefore, although the results in this embodiment are based on the CH group, the film deterioration diagnosis method according to the present invention is based on the CO - O group and C=O Motoyoshi Next of The peak intensity can also be used. In this way, the degree of deterioration of the resin film can also be determined from the peak intensity ratio.

[0035] The above-described analytical method A and analytical method B are effective when the deterioration of the resin film has progressed significantly. If the deterioration of the resin film can be confirmed using at least one of these non-destructive analytical methods, analytical method A and analytical method B, there is no need for further deterioration diagnosis.

[0036] Furthermore, in the film deterioration diagnosis method according to the present invention, it is preferable to use the above-mentioned analytical method A and / or the above-mentioned analytical method B, and then use the following analytical method C and / or analytical method D, which are non-destructive analytical methods. Analysis method C: Check for the presence of acetic acid attached to the film by pH measurement Analysis method D: Confirm the concentration of acetic acid gas released from the film by HPLC analysis

[0037] In the film deterioration diagnosis method according to the present invention, the deterioration state of a resin film can be more reliably grasped by using the nondestructive analysis method of the above-mentioned analysis method A and / or the above-mentioned analysis method B, and then using the nondestructive analysis method of at least one of the above-mentioned analysis method C and analysis method D. These analysis methods C and D will be described below.

[0038] (C) Analysis Method C Analysis method C confirms the presence or absence of acetic acid attached to the film by measuring pH, and is therefore effective when the deterioration state of the resin film cannot be sufficiently confirmed using analysis method A and / or analysis method B. A film deterioration diagnosis method using analysis method C will be described in detail below with reference to an embodiment.

[0039] In the analytical method C according to the present embodiment, a portable pH meter D-71 manufactured by Horiba, Ltd. was used. The ultrapure water was collected from a Direct-Q UV5 ultrapure water production system directly connected to tap water manufactured by Merck Ltd. 100 mL of ultrapure water was then placed in a glass beaker, and a portion of the TAC film (3.5 cm wide x 10 cm long) was immersed in the ultrapure water for 10 seconds, after which the pH of the immersed solution was measured. The TAC films used for measurement in analytical method C according to the present embodiment were the eight films shown in analytical method B according to the above embodiment: undegraded films A to C, odorless films A to C, and odorous films A and B.

[0040] Figure 3 shows the pH measurement results for eight films: undegraded A-C, odorless A-C, and odorous A and B. The error bars in the figure indicate the standard error of the pH measurement results. Figure 3 shows a trend of decreasing pH in the following order: undegraded A-C, odorless A-C, and odorous A and B. This is thought to be due to acetic acid molecules adhering to the TAC film dissolving in the ultrapure water. The pH of odorless B and C films is lower than that of odorless A, suggesting that a larger number of acetic acid molecules may have adhered to the film. While the pH of ultrapure water is theoretically 7.0, due to the immediate absorption of carbon dioxide from the air, the pH becomes slightly acidic (6.9–6.0) over time after sampling from the ultrapure water production system. As TAC film deteriorates, the amount of acetic acid adhering to its surface tends to increase. Therefore, when the pH of the water in which the film is immersed drops below 6.0, deterioration can be considered to be progressing. Thus, the presence or absence of acetic acid adhering to a resin film can be used to determine its state of deterioration.

[0041] (D) Analysis Method D Analysis method D uses HPLC analysis to confirm the concentration of acetic acid gas released from the film, and is therefore effective when the deterioration state of the resin film cannot be sufficiently confirmed using analysis method A and / or analysis method B. A film deterioration diagnosis method using analysis method D will be described in detail below with reference to an embodiment.

[0042] In the analysis method D according to this embodiment, a Prominence LC-20A HPLC system and an SPD-20A UV-vis detector manufactured by Shimadzu Corporation were used. A Shim-pack SCR-102H column manufactured by Shimadzu GLC Corporation was used. The analysis conditions were a 5.0 mM perchloric acid aqueous solution (pH 2.3) as the mobile phase, a flow rate of 1.5 mL / min, a UV detection wavelength of 210 nm, a cell temperature of 40°C, and a sample solution injection volume of 20 μL. A hole was drilled in the center of the lid of a film storage canister (diameter 27.8 cm, height 4.5 cm) made of galvanized steel, and the canister was sealed with a silicone rubber stopper and caulking agent. A TAC film roll was placed in the film storage canister and the lid was then closed. After leaving the canister at room temperature for one week, a hole was drilled in the silicone stopper with a syringe needle. 60 mL of gas was collected from the canister using a 100 mL glass syringe manufactured by Tsubasa Kogyo Co., Ltd., and dissolved in 1 mL of ultrapure water to prepare the sample solution for HPLC analysis.

[0043] Since the area value of the peak observed at a retention time of approximately 7.1 minutes in the chromatogram is proportional to the acetic acid concentration, the acetic acid gas concentration in the film storage can was calculated from the calibration curve. The calibration curve was created using acetic acid (special grade, 99.7% purity) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. The TAC films used for measurements in analysis method D according to this embodiment were the eight films shown in analysis method B according to the above embodiment: undegraded films A to C, odorless films A to C, and odorous films A and B.

[0044] Figure 4 shows the acetic acid gas concentration inside the film storage can, determined by HPLC measurements for eight films: undegraded A-C, odorless A-C, and odorous A and B. Figure 4 confirms that undegraded A-C and odorless A films did not release acetic acid gas into the film storage can. Meanwhile, odorless B film released approximately 14 ppm of acetic acid gas, odorless C film approximately 28 ppm, and odorous A and B films approximately 1300-1500 ppm. Thus, HPLC measurements can be used to quantitatively evaluate the acetic acid gas concentration of resin films during long-term storage in storage cans, enabling the state of degradation to be ascertained.

[0045] Furthermore, in the film degradation diagnosis method according to the present invention, it is preferable to use the above-mentioned non-destructive analysis method, and then use one or a combination of two or more of the following destructive analysis methods, namely, Analysis Methods E to H. Analysis method E: Check the moisture content in the film using a KF moisture meter Analysis Method F: Thermogravimetric Differential Thermal Analysis (TG-DTA) to confirm the thermal stability of the film Analysis method G: Identifying plasticizer species in film by pyrolysis gas chromatography mass spectrometry Analysis Method H: Check the mechanical strength of the film by tensile testing

[0046] In the film degradation diagnosis method according to the present invention, the degradation state of the resin film can be more reliably grasped by using at least one of the destructive analysis methods (Analysis Methods E to H) after using the non-destructive analysis methods (Analysis Methods A to D). These Analysis Methods E to H will be described below.

[0047] (E) Analysis Method E Analysis method E uses a KF moisture meter to confirm the moisture content in the film, and is therefore effective when the deterioration state of the resin film cannot be sufficiently confirmed using the above non-destructive analysis methods (Analysis methods A to D). A film deterioration diagnosis method using analysis method E will be described in detail below with reference to an embodiment.

[0048] In the analysis method E according to the present embodiment, a KF moisture meter AQ-2100 and a moisture vaporizer EV-5A manufactured by Hiranuma Sangyo Co., Ltd. were used. The measurement was carried out by placing a TAC film sample in a heating furnace maintained at 120°C, and quantifying the amount of moisture generated in 20 minutes using the KF method. The TAC films used for the measurement in the analysis method E according to the present embodiment were the eight films shown in the analysis method B according to the above embodiment: undegraded films A to C, odorless films A to C, and odorous films A and B.

[0049] Figure 5 shows the moisture content measurement results for eight films: undegraded A-C, odorless A-C, and odorous A and B. The error bars in the figure indicate the standard error of the KF moisture measurement results. Figure 5 shows that the moisture content in the film tends to increase as the TAC film deteriorates. It is thought that leaving TAC film in the atmosphere for an extended period of time causes moisture to adhere to the base of the TAC film or to be absorbed into the image-generating layer of the film. This is thought to be the reason for the low moisture content in undegraded A-C films. Furthermore, because TAC hydrolysis, once initiated, progresses at an accelerated rate, odorous A and B films are likely to absorb more moisture than odorless A-C films.

[0050] It is known that as resin films deteriorate, their moisture content tends to increase. Therefore, if the moisture content exceeds a certain value, it suggests that the relative humidity in the film storage environment is high, making it more likely that hydrolysis will occur in the future. According to the results shown in Figure 5, a moisture content of 5.5 wt% in the film can be used as a benchmark for film deterioration.

[0051] (F) Analysis Method F Analysis method F is effective when the deterioration state of a resin film cannot be sufficiently confirmed using the above non-destructive analysis methods (Analysis methods A to D) because it confirms the thermal stability of the film by TG-DTA analysis. Hereinafter, a film deterioration diagnosis method using analysis method F will be described in detail based on an embodiment.

[0052] Analysis method F according to this embodiment used a Thermo Plus EVO2 differential thermobalance manufactured by Rigaku Corporation. The measurement conditions were a N2 gas atmosphere, a flow rate of 100 mL / min, a heating rate of 20 °C / min, a measurement temperature range of 25 to 450 °C, a Rigaku α-alumina powder reference, an Al sample pan, and a data acquisition interval of 1.0 s. After placing the TAC film and reference in the sample chamber, N2 gas was allowed to flow for approximately 15 minutes, and measurements were initiated after confirming that the mass had reached a steady state. The TAC films used in analysis method F according to this embodiment were the eight films shown in analysis method B according to the embodiment above: undegraded films A to C, odorless films A to C, and odorous films A and B.

[0053] Figure 6 shows the TG curve measurement results for three films: undegraded A, odorless A, and odorous A. Figure 6 shows that as the degradation of the TAC film progresses, mass loss tends to begin to occur at lower temperatures. The TG curve was differentiated with respect to time, and the temperature at which the slope of the tangent to the TG curve was greatest was defined as the peak thermal decomposition temperature, and these values ​​were compared for each film.

[0054] Figure 7 shows the thermal decomposition peak temperature of TAC film obtained from the TG curves for eight films: undegraded A-C, odorless A-C, and odorous A and B. Figure 7 shows a tendency for the thermal decomposition peak temperature to decrease as the degradation of the TAC film progresses. It also shows that the thermal decomposition peak temperature of odorless A-C films is approximately 5°C lower than that of undegraded A-C films. This is thought to be due to main chain scission of the TAC occurring with aging, resulting in a decrease in the degree of polymerization.

[0055] From the above, it can be seen that when the thermal decomposition peak temperature of TAC film falls below a certain value, the degree of polymerization decreases due to main chain cleavage in the resin structure, suggesting the progression of oxidation reactions and plasticizer leaching. In this way, by focusing on the thermal decomposition peak temperature, it is possible to quantitatively determine the state of deterioration of a resin film. The thermal decomposition peak temperature does not require a baseline to be drawn, and can be easily calculated using software, making it an indicator with little reading error.

[0056] (G) Analysis Method G Analysis method G uses Py-GC / MS analysis to identify the type of plasticizer in the film, and is therefore effective when the deterioration state of the resin film cannot be adequately confirmed using the above non-destructive analysis methods (Analysis methods A to D). A film deterioration diagnosis method using analysis method G will be described in detail below with reference to an embodiment.

[0057] In the analysis method G according to the present embodiment, a GC-MS system 7890B / 5977B manufactured by Agilent Technologies Inc. and a multi-shot pyrolyzer EGA / PY-3030D manufactured by Frontier Labs Inc. were used as the apparatus. In addition, a UA column manufactured by Frontier Labs Inc. was used as the column. + We used a Phenomenex ZB-MultiResidue-1 or ZB-xLB-HT Inferno. TAC film analysis was performed using these instruments and columns. GC conditions were: inlet temperature 300 °C, carrier gas He, column flow rate 1.2 mL / min (constant flow mode), split ratio 50:1, furnace temperature 550 °C, ITF temperature 300 °C, oven temperature 40 °C (2 min) - 20 °C / min - 300 °C (5 min). MS conditions were: electron ionization (70 eV), ion source temperature 250 °C, quadrupole temperature 150 °C, interface temperature 250 °C, scan range m / z 29–400 (sampling 3), and gain 1. The TAC films used for measurement in analysis method G of this embodiment were eight films shown in analysis method B of the above embodiment: undegraded A to C, odorless A to C, and odorous A and B.

[0058] Figure 8 shows the Py-GC / MS results for undegraded film A, Figure 9 shows undegraded film B, and Figure 10 shows undegraded film C. Figure 11 shows the Py-GC / MS results for odorless film A, Figure 12 shows odorless film B, Figure 13 shows odorless film C, Figure 14 shows odorous film A, and Figure 15 shows odorous film B. Figures 8-15 indicate that triphenyl phosphate was detected in all films. Ethyl phthalyl ethyl glycolate was detected in odorless films A-C, but not in undegraded films A-C or odorous films A and B. Phthalic anhydride was detected in odorous films A and B. This is thought to be the result of the decomposition of ethyl phthalyl ethyl glycolate, which was originally present in the films, during degradation. These results suggest that the presence or absence of ethyl phthalyl ethyl glycolate may be related to the progression of degradation.

[0059] From the above, analysis method G according to this embodiment yielded results indicating that ethylphthalyl ethyl glycolate is contained as a plasticizer in the TAC film, suggesting the possibility that this content is related to film deterioration. Thus, Py-GC / MS is positioned as a method for qualitatively analyzing whether the plasticizer in the resin film has volatilized or decomposed, and for determining whether deterioration is progressing, and is effective in evaluating the presence or absence of plasticizer-derived precipitates and whether the film contains the plasticizer necessary to prevent deterioration.

[0060] (H) Analysis Method H Analysis method H is effective when the deterioration state of a resin film cannot be adequately confirmed using the above non-destructive analysis methods (Analysis methods A to D) because it confirms the mechanical strength of the film through a tensile test. A film deterioration diagnosis method using analysis method H will be described in detail below with reference to an embodiment.

[0061] In the analysis method H according to the present embodiment, the equipment used was a benchtop precision universal testing machine Autograph AGS-X manufactured by Shimadzu Corporation and an SD-type lever-type sample cutter SDL-100 manufactured by Dumbbell Corporation. The measurement conditions were a load cell of 1 kN, a test speed of 10 mm / min, and a gripper distance of 20 mm. The film samples used were TAC films cut into a JIS K6251 dumbbell No. 7 shape, and the stress (breaking force) at the moment of breakage was measured. The TAC films used for measurement in the analysis method H according to the present embodiment were the eight films shown in the analysis method B according to the above embodiment: undegraded A to C, odorless A to C, and odorous A and B.

[0062] Figure 16 shows the stress values ​​at film breakage obtained from tensile tests on eight films: undegraded A-C, odorless A-C, and odorous A and B. The error bars in the figure indicate the standard error of the stress values ​​at film breakage. Figure 16 shows a tendency for the breaking strength to decrease as hydrolysis progresses in the TAC film. Furthermore, the breaking strength of odorless B and C films was lower than that of undegraded A-C and odorless A films. This is thought to be due to a decrease in plasticizer content and a decrease in molecular weight due to TAC main chain cleavage, suggesting that such degradation occurs in aged TAC films other than hydrolysis.

[0063] It is generally known that the mechanical strength of a polymer decreases as it deteriorates. Therefore, according to the results shown in Figure 16, the breaking strength is 120 N / mm 2 The following can be used as one of the criteria for TAC film degradation indicators. In this way, by conducting a tensile test in addition to chemical analysis methods, it is possible to evaluate the state of degradation of the resin film from the perspective of physical strength.

[0064] In the film deterioration diagnosis method according to the present invention, the resin film is preferably a TAC film. TAC film has high flame resistance and can be stored for a long period of time, making it suitable for use as a film for archival purposes. Furthermore, the deterioration state of TAC film can be efficiently and reliably determined using the film deterioration diagnosis method according to the present invention, which significantly enhances the safety and reliability of TAC film as a film for archival purposes compared to other resin films.

[0065] The above describes an embodiment of the film deterioration diagnosis method of the present invention. The film deterioration diagnosis method of the present invention can improve the accuracy of determining the deterioration of resin films compared to conventional methods by combining multiple types of analysis results and making complementary judgments.

[0066] FIG. 17 is a chart showing an outline of the film deterioration diagnosis method according to the present embodiment. The film deterioration diagnosis method according to the present invention obtains fixed information for each analysis item, and determines the state of deterioration based on whether the analysis result exceeds (or falls below) a certain threshold. Therefore, the film deterioration diagnosis method according to the present invention can perform comprehensive and highly accurate deterioration diagnosis by performing multiple types of analysis methods in stages. Furthermore, although the analysis procedure shown in FIG. 17 follows the order of analysis methods A to H described above, the film deterioration diagnosis method according to the present invention does not necessarily have to follow this same procedure, and it is not necessarily required to perform all of the analysis methods. Therefore, the film deterioration diagnosis method according to the present invention can efficiently perform deterioration diagnosis. [Industrial Applicability]

[0067] According to the present invention, the deterioration state of a resin film can be grasped more efficiently and reliably than before, which allows measures to be taken to prevent deterioration of the resin film as soon as possible, and prevents the loss of valuable historical materials, documents, etc. recorded on the film.

Claims

1. A method for diagnosing deterioration of a cellulose triacetate film, comprising the use of the following analytical method B, which is a non-destructive analytical method. Analysis method B: The cellulose triacetate film is analyzed by Fourier transform infrared spectroscopy to check for the presence or absence of a peak derived from an acid anhydride observed at wave numbers of 1790 cm −1 to 1850 cm −1 , or to check the peak intensity ratio, which is the value obtained by dividing the peak intensity derived from OH groups by the peak intensity derived from CH 3 groups, C═O groups, or C—O—O groups.

2. The method for diagnosing deterioration of a cellulose triacetate film according to claim 1, further comprising the step of using one or a combination of two or more of the following destructive analytical methods E to H after the non-destructive analytical method has been used: Analysis Method E: The moisture content in the cellulose triacetate film is determined using a Karl Fischer moisture meter. Analysis Method F: The thermal stability of the cellulose triacetate film is confirmed by thermogravimetric differential thermal analysis. Analysis Method G: The type of plasticizer in the cellulose triacetate film is identified by pyrolysis gas chromatography mass spectrometry. Analysis Method H: The mechanical strength of the cellulose triacetate film is confirmed by a tensile test.

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