JP2011149843A - Accelerated deterioration method for polyurethane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an accelerated deterioration testing method enhanced in a correlation with outdoor exposure with respect to a sealing material containing polyether based polyurethane, and to provide a deterioration degree evaluation method of high precision. <P>SOLUTION: The sealing material containing polyether based polyurethane is placed under a condition that a temperature range is 70-90°C and a humidity range is 0-10% RH to be accelerated in deterioration. Furthermore, the deterioration of the sealing material accelerated in deterioration is evaluated by measuring a change in the amount of the pyrolytic product originating from a polyether part using a pyrolytic gas chromatography method or a pyrolytic gas chromatography/mass analyzing method. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an accelerated deterioration method for evaluating the weather resistance of a polyether-based polyurethane.

  Polyether-based polyurethanes are mainly used as a sealing material because of their excellent mechanical properties and workability, and are often used particularly in the construction field. Architectural sealants are often used under harsh conditions such as outdoors, such as being exposed to high temperatures, and high weather resistance has been demanded. Currently, a sealing material having high weather resistance is being developed, but an accelerated deterioration method for quickly evaluating it has not yet been established.

  Normally, when testing the method of evaluating the degree of deterioration of a polymer material and evaluating its weather resistance, a deterioration acceleration test combining temperature, humidity (watering), or ultraviolet rays as factors that promote deterioration is performed. A method of artificially promoting the deterioration of the polymer material is employed.

  The sealing material may be directly exposed to the atmosphere or may be exposed to the atmosphere while being covered with an exterior coating film or the like. Therefore, when evaluating weather resistance, it is necessary to use an accelerated deterioration test method according to the exposure situation.

  Conventionally, as a method for accelerating deterioration of a polyurethane-based sealant, Patent Document 1 proposes a method in which temperature and relative humidity are combined. However, this method cannot keep the surface state uniform because the additive bleeds out and accumulates on the surface of the sealing material. Therefore, it is difficult to accurately reproduce the deterioration state of outdoor exposure.

  Non-Patent Document 1 introduces an accelerated deterioration method using a xenon weather meter or an ultraviolet fluorescent tube without covering the surface of a urethane-based sealing material. Methods for analyzing processing, color difference change, and crack generation have been proposed. However, this method has a problem that the surface deterioration is accelerated more than the inside and the effect of ultraviolet rays on the deterioration is unclear.

JP 2004-137383 A

EFFECT OF CONDITIONS OF LABORATORY WEATHERING ON THE CORRELATION WITH NATURAL EXPOSURES BASED ON THE RESULTS OF SEALANTS STUDIES, 4th International Symposium on Weatherability, 24-38 (2000)

This invention is made | formed in view of the said situation, and it aims at providing the accelerated deterioration method of the polyether-type polyurethane which can eliminate the said malfunction at least partially.
In particular, an object of the present invention is to provide an accelerated deterioration test method having a high correlation with outdoor exposure, and also provide a highly accurate deterioration degree evaluation method.

According to the first invention, a polyether-based polyurethane sealing is characterized in that a sealing material comprising a polyether-based polyurethane is placed under conditions of a temperature range of 70 ° C. to 90 ° C. and a humidity range of 0 to 10% RH. A method for accelerated degradation of materials is provided.
According to the second invention, there is provided an accelerated deterioration method for a polyether-based polyurethane sealing material according to the first invention, wherein the sealing material is a non-direct exposure type sealing material.
According to the third invention, there is provided a deterioration evaluation method for a sealing material, characterized by evaluating the deterioration of the polyether-based polyurethane sealing material whose deterioration is accelerated by the accelerated deterioration method of the first or second invention. Is done.
According to the fourth invention, in the third invention, there is provided a method for evaluating the degree of deterioration of a sealing material, characterized in that the deterioration of the sealing material is evaluated using a pyrolysis gas chromatography method.
According to the fifth invention, in the third invention, there is provided a method for evaluating the deterioration degree of a sealing material, characterized in that the deterioration of the sealing material is evaluated using pyrolysis gas chromatography / mass spectrometry. .
According to a sixth invention, in any one of the third to fifth inventions, the deterioration of the sealing material is evaluated by measuring a change in the amount of the thermal decomposition product derived from the polyether part. A method for evaluating the degree of deterioration of a sealing material is provided.

  According to the present invention, an accelerated deterioration test method having a high correlation with outdoor exposure can be obtained for a polyether-based polyurethane sealing material, and weather resistance can be evaluated accurately and quickly.

It is the schematic of the thermal decomposition gas chromatography mass spectrometer which can be used in order to implement the degradation degree evaluation method concerning one Embodiment of this invention. Pyrograms (holding time :) of a sealing material sample before performing the accelerated deterioration method according to an embodiment of the present invention (0 hour) and a sealing material sample after performing the accelerated deterioration method at an accelerated deterioration time of 10000 hours 0 min to 10 min). In the figure, peak 1 is diisopropyl ether and peak 2 is 4-isopropoxy-2-butanone. The sealing material sample before the accelerated degradation method according to an embodiment of the present invention (0 hour) and the accelerated degradation method with accelerated degradation times of 2000 hours, 4000 hours, 6000 hours, 8000 hours, and 10,000 hours. The sealing material sample after the measurement was measured by pyrolysis gas chromatography, and the area ratio of each peak of diisopropyl ether and 4-isopropoxy-2-butanone to the area of all the peaks in the sample was calculated. The change of the area ratio of each peak in diisopropyl ether and 4-isopropoxy-2-butanone when is set to 1 is shown. Measure the sealing material collected from the south side of the building 5 years, 6 years, 11 years, 14 years after completion using the same composition as the one with the accelerated deterioration method by pyrolysis gas chromatography, The area ratio of each peak of diisopropyl ether and 4-isopropoxy-2-butanone to the area of all the peaks in the sealing material sample was calculated, and diisopropyl ether and 4-isopropoxy-2-butanone when the pre-deterioration was assumed to be 1 The change of the area ratio of each peak in is shown.

  The inventors of the present invention accurately control the deterioration state of the sealing material due to outdoor exposure by appropriately controlling the temperature and humidity at which the sealing material is exposed to the sealing material mainly composed of polyether-based polyurethane. It was found that an accelerated deterioration method that can be reproduced and has a very high correlation with deterioration due to outdoor exposure is obtained. In other words, it is generally known that polyether-based polyurethanes undergo thermal oxidation reaction or hydrolysis reaction of the polyether portion of the soft segment. It has been clarified that it is particularly important to cause the thermal oxidation reaction to reproduce the deterioration state of the sealing material due to outdoor exposure. Moreover, in order to achieve such conditions, the sealing material may be placed under conditions of a temperature range of 70 ° C. to 90 ° C. and a humidity range of 0 to 10% RH, thereby reproducing outdoor exposure in a short period of time. I found out that I can do it. Here, when the temperature is 70 ° C. or lower, the acceleration of deterioration is low and the test takes a long time. On the other hand, when the temperature is 90 ° C. or higher, the thermal oxidative decomposition is severe and the outdoor exposure deterioration state cannot be reproduced. On the other hand, when the humidity is 10% RH or more, the hydrolysis is severe and the deterioration state of outdoor exposure cannot be reproduced.

  Furthermore, in order to accurately reproduce the deterioration state of outdoor exposure, the present inventors efficiently remove plasticizers and additives that bleed out on the surface of the sealing material, and keep the surface state of the sealing material constant. Found that it is necessary to keep on. This is because the diffusion rate of the plasticizer or additive in the surface direction needs to be kept constant. Therefore, in one embodiment of the present invention, in order to keep the surface state of the sealing material sample constant, an absorbent body or an adsorbent body that can remove the plasticizer and additive that bleed out on the surface of the sealing material is provided on the surface. Such an absorber or adsorbent serves to keep the surface state of the sealing material constant and to keep the diffusion rate of the plasticizer and additives in the surface direction constant, as well as a constant temperature and humidity chamber for performing accelerated deterioration tests To prevent surface contamination.

  The properties that the absorber or adsorbent should have are that it absorbs plasticizers and additives, allows water vapor to pass, and does not chemically react with the sample. Therefore, as the absorber or adsorbent, cellulose-based, polyethylene-based, polypropylene-based, polyester-based, glass fiber-based, polyvinylidene fluoride-based, polytetrafluoroethylene-based nonwoven fabric, woven fabric or porous sheet, zeolite-based, Inorganic adsorbents such as silica, alumina, and tobermorite, or activated carbon can be used.

When arranging the absorber or adsorbent, it is desirable to apply pressure from above the absorber or adsorbent in order to improve adhesion to the sample and enable efficient removal of the plasticizer and additives. . The pressure for such pressurization is preferably 0.01 to 1 g / cm ² . If it is 0.01 g / cm ² or less, it cannot be efficiently removed. On the other hand, if it is 1 g / cm ² or more, deformation of the sheet occurs, which is not preferable. Furthermore, when using an absorber or an adsorbent, it is preferable to replace the absorber or adsorbent as appropriate in order to efficiently remove the plasticizer and additives.

  Here, the sealing material comprising the polyether-based polyurethane as a main component of the present invention will be described. The sealing material contains the above-described plasticizer and additives in addition to the polyether-based polyurethane. As additives, heat stabilizers, ultraviolet absorbers, light stabilizers, antioxidants, algaeproofing agents, fungicides, antifoaming agents, thickeners, dispersants, fillers, pigments, etc. are appropriately selected. The

  The polyether-based polyurethane is obtained by a reaction between a curing agent having at least two isocyanate groups and a polyol compound having at least two hydroxyl groups.

The one-component polyether-based polyurethane is, for example, cured by reacting with moisture in the air using a prepolymer obtained by reaction of diisocyanate with polyether diol and polytriol as a raw material. The two-component polyether polyurethane is cured by reacting a prepolymer obtained by reaction of diisocyanate with polyether diol and polytriol and a polyol or polyamine as a curing agent.
Examples of the above-mentioned isocyanate include toluene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate.

  The above-mentioned polyol has two or more hydroxyl groups per molecule, and the number average molecular weight is preferably in the range of 400 to 7000. Examples of the diol include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxyhexamethylene glycol, and an ethylene oxide / propylene oxide copolymer. Examples of the triol include polyoxyethylene triol, polyoxypropylene triol, polyoxytetramethylene triol, and polyoxyhexamethylene triol. It is also preferable to use a mixture of triol and diol as appropriate.

  As the plasticizer, polymer plasticizers such as phthalate ester compounds, polyesters or aliphatic polyurethanes can be used alone or in combination. Typical examples of the heat stabilizer include a hindered phenol compound, the ultraviolet absorber includes a benzotriazole compound or a hydroxyphenyltriazine compound, and the light stabilizer includes a hindered amine compound.

  In the above description, the case where the exterior coating film is not provided on the surface of the sealing material has been described. However, the accelerated deterioration method of the present invention is the same for the non-direct exposure type sealing material provided with the exterior coating film on the surface of the sealing material. Applicable to. In addition, when the non-direct exposure type sealing material is accelerated and deteriorated by the accelerated deterioration method of the present invention, the aforementioned absorber or adsorbent may or may not be present. In order to remove it, it is preferable to provide an absorber or an adsorbent.

  In addition to the above accelerated deterioration method, here, a sealing material deterioration degree evaluation method for evaluating the deterioration of the sealing material whose deterioration has been accelerated by the accelerated deterioration method is also disclosed. That is, the inventors of the present invention have found that the degree of change in the composition of a specific component of the polyether-based polyurethane indicates the degree of deterioration, not a method for evaluating the appearance or physical shape of the sealing material. Estimate the degree of degradation of polyether polyurethane by measuring pyrolysis products derived from the polyether part of polyether polyurethane using pyrolysis gas chromatography or pyrolysis gas chromatography and mass spectrometry Succeeded in doing.

  Therefore, in the degradation degree evaluation method according to an embodiment of the present invention, pyrolysis gas chromatography is used, and the amount of pyrolysis products derived from the polyether portion of the polyether polyurethane, for example, the composition ratio of the gas chromatogram is calculated. By measuring, the degree of deterioration of the polyether-based polyurethane is estimated. In the degradation degree evaluation method according to another embodiment of the present invention, the pyrolysis gas chromatography / mass spectrometry (pyrolysis gas chromatography) can be used even if the types of the monomer components and additives constituting the polyether polyurethane are not known. By performing quantitative analysis after or simultaneously with qualitative analysis by an analytical method in which chromatography and mass spectrometry are continuously performed, it is possible to accurately evaluate the degree of deterioration.

  Pyrolysis gas chromatography (PyGC) is a separation / analysis method that instantly pyrolyzes a small amount of sample, introduces and separates the pyrolysis products into a gas chromatograph, and obtains a pyrogram (Koji Hiroshi, 2002). Hokkaido Industrial Research Institute Technical Information, Vol. 24, No. 4, p. 11). Thermal decomposition of samples such as black rubber, which was difficult with thermal analysis methods such as infrared spectroscopy and differential scanning calorimetry, and polymers with no melting point such as rubber and thermosetting resins Gas chromatography is applicable.

  Mass spectrometry (MS) is an analytical method used when determining the mass-to-charge ratio (value obtained by dividing mass by the number of charges) of a sample. In the method of the present invention, electron impact ionization, chemical ionization, field ionization, or fast atom bombardment ionization method can be used, and a single focusing magnetic field deflection type, a quadrupole type, an ion trap type, a double focusing type, or an ion cyclotron. A type of mass spectrometer can be used, but is not limited thereto.

  The degree of deterioration of the sealing material is calculated by calculating the composition ratio of the gas chromatogram of the pyrolysis product derived from the polyether part of the polyether polyurethane by pyrolysis gas chromatography with respect to the sampled sealing material. Evaluate by looking at This is to estimate the degree of deterioration of the polyether polyurethane by utilizing the phenomenon that the composition ratio of the thermal decomposition products derived from the polyether part in the polyether polyurethane increases with the deterioration of the polyether polyurethane. .

  Here, “the composition ratio of the thermal decomposition product derived from the polyether part in the polyether-based polyurethane” means a specific part derived from the polyether part relative to the total thermal decomposition product generated by pyrolyzing the polyether-based polyurethane. It means the content ratio of pyrolyzate. This content ratio can be estimated from the peak area ratio of the chromatogram.

  Further, the “thermal decomposition product derived from the polyether part” is alcohol, ether or ketone produced by the thermal decomposition of the polyether part. The thermal decomposition products when polyoxypropylene triol is used as the polyol are diisopropyl ether and 4-isopropoxy-2-butanone. In particular, diisopropyl ether has high sensitivity to deterioration, which is advantageous in determining the degree of deterioration.

  In the method of the present invention, the sample for evaluating the degree of deterioration of the polyether-based polyurethane may be several mg, for example, and at least about 0.01 mg can be evaluated.

  In addition, in the sealing material, as described above, in addition to the plasticizer, a heat stabilizer, an ultraviolet absorber, a light stabilizer, an antioxidant, an antialgae, an antifungal agent, an antifoaming agent, a thickener, Although various additives such as a dispersant, a filler, and a pigment are included, there is no problem in evaluating the deterioration degree of the sealing material even if they are present.

  In addition, since the degradation evaluation method of the present invention uses pyrolysis gas chromatography as an analysis method, it is possible to measure with high sensitivity and high accuracy even in a solid sample. In the measurement, the gas generated by heating the sample is separated by a column to perform qualitative and quantitative measurement. Here, the heating temperature can be changed depending on the type of the polyether-based polyurethane, and is usually preferably 400 ° C. to 700 ° C. If the temperature is lower than 400 ° C., the decomposition of the polyether-based polyurethane hardly occurs. If the temperature is higher than 0 ° C., the decomposition of the polyether-based polyurethane and the additive proceeds so much that a large amount of unnecessary components are produced, making it difficult to quantify. The heating conditions are preferably performed in a short time of 0.1 to 2 seconds uniformly over the entire sample. This is because when the heating time is prolonged, a side reaction occurs and a component different from the decomposition product is generated. Further, by raising the temperature during heating, the polyether polyurethane and the additive can be identified and analyzed.

  As a method for thermally decomposing a sample, a filament type, induction heating type, or heating furnace type pyrolysis apparatus is used, and an optimum one may be selected depending on the sample to be measured. The gas chromatograph apparatus may be a general apparatus, and the column stationary phase may be selected according to the sample to be measured. Regarding the detector, there are a flame ionization detector, a thermal conductivity detector, an electron capture detector, and the like, which can be selected as necessary.

  Moreover, when the component obtained by separating by pyrolysis gas chromatography is unknown, each component can be identified by performing mass spectrometry. It is preferable to use pyrolysis gas chromatography mass spectrometry (PyGC-MS) mass spectrometry using a series of apparatuses in which a pyrolysis gas chromatograph apparatus and a mass spectrometer are directly connected.

  FIG. 1 is a schematic view of a pyrolysis gas chromatography mass spectrometer. A polyether-based polyurethane sealing material sample to be analyzed is put into the sample injection unit 2. When the temperature of the thermal decomposition apparatus 3 reaches a predetermined value, the input sample is supplied into the thermal decomposition apparatus 3 and rapidly heated to be decomposed. The gas generated by heating and decomposing the polyether-based polyurethane sealing material sample is introduced into the column 4 by the carrier gas 1. When performing a gas chromatograph analysis, it is analyzed by the detector 6 through the splitter 5. When mass analysis is necessary, it is introduced into the interface 7 through the splitter 5 and then introduced into the mass spectrometer 8 to perform mass analysis. A double shot pyrolyzer PY-1020D manufactured by Frontier Laboratories can be used for the thermal decomposition section (thermal decomposition apparatus 3). Agilent's P-6890 can be used for the gas chromatograph part (detector 6). For the mass spectrometer (mass spectrometer 8), AutoMass-II manufactured by JEOL can be used.

  Such pyrolysis gas chromatography mass spectrometry enables qualitative analysis of samples, not only polyether polyurethane, but also plasticizer, hindered phenol thermal stabilizer, hindered amine light stabilizer (HALS) and ultraviolet absorber. Qualitative and quantitative determination of additives such as (UVA) is possible. Therefore, it is possible to know the amount of hindered phenol heat stabilizer of the deteriorated polyether polyurethane, the remaining amount of HALS and UVA, together with the evaluation of the deterioration degree of the polyether polyurethane, the heat stabilizer of hindered phenol, The stabilizing effect of HALS and UVA or the effect of such additives on the weather resistance of the polyether polyurethane can be confirmed.

  In summary, according to the present invention, it is important for the reproduction of the deterioration state of outdoor exposure to suppress the hydrolysis reaction of the polyether polyurethane as much as possible and to cause an appropriate thermal oxidation reaction. I found out. Therefore, in one embodiment of the present invention, the deterioration condition of outdoor exposure is accurately reproduced by accelerated deterioration of the polyether-based polyurethane sealing material in the temperature range of 70 ° C. to 90 ° C. and humidity of 0% RH to 10% RH. can do.

  Further, a deterioration degree evaluation method for evaluating deterioration of a sealing material whose deterioration is accelerated by the accelerated deterioration method of the invention is provided. According to one embodiment of the invention, the deterioration of the sealing material whose deterioration is accelerated is provided. The degradation degree evaluation method for evaluating the degradation of the sealing material for estimating the degradation degree is provided by measuring the change in the amount of the thermal decomposition product derived from the polyether part in the polyether polyurethane. Rather than evaluating the appearance and physical shape, it is possible to objectively evaluate the degree of degradation compared to conventional methods by measuring changes in the components that form polyether polyurethane and the amount of thermal decomposition products derived from the polyether part. It is possible to carry out, and the accuracy of deterioration degree evaluation is excellent.

  According to one embodiment of the present invention, the degree of deterioration is estimated by measuring the change in the amount of pyrolysis products derived from the polyether portion in the polyether-based polyurethane by pyrolysis gas chromatography. In this form, the deteriorated polyether polyurethane can be directly applied to the analysis sample as it is without pretreatment, and the accuracy of the deterioration evaluation can be improved. Are better. In addition, it is possible to estimate the degree of deterioration even with a small amount of sample of several mg or less, and it is not affected by the color and melting point of the sample much like spectroscopic analysis methods such as infrared spectroscopic analysis and differential scanning calorimetry. There are also advantages.

  Furthermore, in one embodiment, the degradation degree is estimated by measuring a change in the amount of pyrolysis products derived from the polyether portion in the polyether-based polyurethane by pyrolysis gas chromatography and mass spectrometry. Quantitative analysis is possible after qualitative analysis by pyrolysis gas chromatography and mass spectrometry, even if the type of polyether polyurethane and additive is not known. Can be performed. Therefore, since it can be used even when the types of the polyether-based polyurethane and additives are unknown, the polyether-based polyurethane capable of evaluating the deterioration degree is excellent in a wide range. Moreover, even if many additives, such as a heat stabilizer and a ultraviolet absorber, are contained, it is excellent also in that they are not affected by them.

As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable.
Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1
<Creation of sealing material>
10% by weight of polyoxypropylene triol having a weight average molecular weight of 5000, 50% by weight of polyoxypropylene glycol having a weight average molecular weight of 2000 and 29% by weight of di-2-ethylhexyl phthalate are placed in a reaction vessel, and the pressure is reduced at 110 ° C. and 50 mmHg for 2 hours. Dehydrated. Thereafter, the reaction product was cooled to 80 ° C., and 11% by weight of 4,4-diphenylmethane diisocyanate was added and stirred. It was made to react at 80 degreeC for 30 hours, and the isocyanate containing urethane prepolymer was obtained.

60% by weight of the isocyanate-containing urethane prepolymer obtained above is placed in a kneading vessel filled with dry nitrogen gas, and further, 25% by weight of calcium carbonate, 5% by weight of silica, and 10% of xylene as a solvent as fillers. % By weight and kneaded in a stirrer to obtain a urethane-based sealing composition. The urethane-based sealing composition thus obtained was prepared into a sheet having a thickness of 2 mm, and was cured for 4 weeks at 23 ° C. and 50% relative humidity.
The following test was performed using the test body cut out from the above sample.

<Accelerated deterioration test>
As an accelerated deterioration test, both sides of the prepared sheet were sandwiched between 1 mm thick cellulose-based non-woven sheets adsorbing oil components, pressurized at 0.5 g / cm ² , and exposed to constant temperature and humidity. Moreover, this cellulose nonwoven fabric sheet was replaced every 2000 hours. The conditions of the accelerated deterioration test were a temperature of 80 ° C. and a humidity of 5% RH, and the accelerated deterioration test time was 2000 hours, 4000 hours, 6000 hours, 8000 hours, and 10,000 hours. Each sheet subjected to each accelerated deterioration test was taken out of the thermo-hygrostat after the test, and used for analysis. A 0.5 mg sample for analysis was obtained from the inside (near the center) of the sheet before and after the accelerated deterioration test, and used for pyrolysis gas chromatography mass spectrometry.

<Pyrolysis gas chromatography mass spectrometry>
Thermal decomposition was performed at a thermal decomposition temperature of 600 ° C. using a thermal decomposition apparatus (Double Shot Pyrolyzer PY-1020D manufactured by Frontier Laboratories). The column used in the gas chromatography was Durabond DB-1 (inner diameter: 0.25 mm, length: 30 m, film thickness: 0.25 μm), and a detector (P-6890) manufactured by Agilent was used. The temperature conditions were maintained at 50 ° C. for 5 minutes, heated from 50 ° C. to 320 ° C. (temperature increase rate: 10 ° C./minute), and maintained at 320 ° C. for 8 minutes. For mass spectrometry, AutoMass-II manufactured by JEOL was used. The mass spectrometric measurement conditions are an electron impact ionization method and a mass measurement range: m / z = 10 to 700 (m: mass, z: charge).

  The sealant sample before the accelerated deterioration test was analyzed by pyrolysis gas chromatography to obtain a pyrogram (0 hr in FIG. 2). Furthermore, about the sealing material sample before implementation of an accelerated deterioration test, each component was qualitatively acquired by acquiring the mass spectrometry spectrum of each component isolate | separated with the gas chromatograph. As a result, diisopropyl ether was detected at a retention time of 6.1 minutes, 1,2,4-trimethylcyclopentane (a peak unique to the sealing material) was detected at 6.3 minutes, and 4 minutes at 6.5 minutes. -Isopropoxy-2-butanone was detected. Moreover, 4,4-diphenylmethane diisocyanate and di-2-ethylhexyl phthalate could be detected in the portion with a long retention time.

In addition, pyrolysis gas chromatography analysis was performed in the same manner as described above for the sealing samples subjected to the accelerated degradation test at 80 ° C., 5% RH, 2000 hours, 4000 hours, 6000 hours, 8000 hours, and 10,000 hours. Thus, a pyrogram was obtained for each sample (only a sealing sample subjected to a 10,000 hour accelerated deterioration test is shown in FIG. 2).
Comparing the pyrogram obtained from the sealing material sample before the accelerated deterioration test (0 hour) with the pyrogram obtained from the sealing material sample subjected to the accelerated deterioration test for each deterioration test time, the accelerated deterioration test time increases. As a result, the peak area ratio of diisopropyl ether and 4-isopropoxy-2-butanone increased, and the correlation with the accelerated deterioration test time was high. On the other hand, for 1,2,4-trimethylcyclopentane, the area ratio decreased with the accelerated deterioration test time, and the correlation was not so high.

  Diisopropyl ether and 4 for the area of all peaks in the sealant sample before the accelerated degradation test (0 hour) and the sealant samples subjected to the accelerated degradation test for 2000 hours, 4000 hours, 6000 hours, 8000 hours, and 10,000 hours. -The area ratio of each peak of isopropoxy-2-butanone was calculated, and the increase / decrease ratio of each peak area of diisopropyl ether and 4-isopropoxy-2-butanone when the pre-accelerated deterioration was set to 1 was obtained. Indicated. As can be seen from this result, the accelerated deterioration test time increased, and the increase / decrease ratio of diisopropyl ether and 4-isopropoxy-2-butanone increased. That is, it was found that the degree of deterioration of the sealing material can be estimated from the value of the increase / decrease ratio of each peak area of diisopropyl ether and 4-isopropoxy-2-butanone. It was also found that the initial deterioration state has a good correlation with the accelerated deterioration time, and the initial deterioration state can be grasped. In particular, diisopropyl ether has high sensitivity to deterioration, and is considered more suitable as an indicator of deterioration.

Example 2
<Evaluation of degradation level of actual exposed paint film>
Sampling the sealant from the south of a building that has been used for 5 years, 6 years, 11 years, and 14 years after completion using a sealant with the same composition as the one subjected to accelerated deterioration test, and pyrolysis gas chromatography mass spectrometry It was used for. Perform the same analysis as above, calculate the area ratio of each peak of diisopropyl ether and 4-isopropoxy-2-butanone to the area of all the peaks in the sealing material sample, and diisopropyl ether peak when 1 before deterioration And the increase / decrease ratio of each peak area of 4-isopropoxy-2-butanone was calculated | required and it showed in FIG. As a result, it was found that the peak area ratio had a good correlation with the actual exposure time even in the actual exposure test.

  3 and 4, in the case of diisopropyl ether, the accelerated deterioration test time is 400 hours, which corresponds to almost one year of actual exposure (exposure by actual aged buildings). In the case of 4-isopropoxy-2-butanone The accelerated degradation test time of 420 hours was found to correspond to almost one year of actual exposure (exposure over actual aged buildings). As a result, it was found that the degree of deterioration can be accurately evaluated by quantifying the thermal decomposition product derived from the polyether part, and can be applied to deterioration diagnosis.

Comparative Example 1
<Accelerated deterioration test>
Using the sheet prepared in Example 1, an accelerated deterioration test was performed under the same conditions as in Example 1 except that the temperature was 100 ° C. and the humidity was 5% RH. The accelerated deterioration test time was 10,000 hours. The sheet subjected to this accelerated deterioration test was taken out of the thermo-hygrostat after the test time and used for analysis. In addition, 0.5 mg of an analytical sample was obtained from the inside (near the center) of the sheet before and after the accelerated deterioration test, and used for pyrolysis gas chromatography mass spectrometry.
As a result of analysis, the peak area ratio of diisopropyl ether was extremely large, and outdoor exposure was not reproduced at all.

Comparative Example 2
<Accelerated deterioration test>
Using the sheet prepared in Example 1, an accelerated deterioration test was performed under the same conditions as in Example 1 except that the temperature was 80 ° C. and the humidity was 80% RH. The accelerated deterioration test time was 500 hours. The sheet subjected to this accelerated deterioration test was taken out of the thermo-hygrostat after the test time and used for analysis. In addition, 0.5 mg of an analytical sample was obtained from the inside (near the center) of the sheet before and after the accelerated deterioration test, and used for pyrolysis gas chromatography mass spectrometry.
As a result of analysis, the peak area ratio of diisopropyl ether was extremely large, and outdoor exposure was not reproduced at all.

  As described above, the accelerated deterioration method of the polyether-based polyurethane sealing material of the present invention can evaluate the weather resistance quickly and accurately, and thus obtain basic data for developing a new material and estimating the service life. It is extremely useful as a method.

DESCRIPTION OF SYMBOLS 1 Carrier gas supply 2 Sample injection part 3 Pyrolysis apparatus 4 Column 5 Splitter 6 Gas chromatograph detector 7 Interface 8 Mass spectrometer

Claims (6)

  A method for accelerating deterioration of a polyether-based polyurethane sealing material, comprising placing a sealing material comprising a polyether-based polyurethane under conditions of a temperature range of 70 ° C. to 90 ° C. and a humidity range of 0 to 10% RH.   2. The accelerated deterioration method for a polyether-based polyurethane sealing material according to claim 1, wherein the sealing material is a non-direct exposure type sealing material.   A deterioration evaluation method for a sealing material, wherein the deterioration of the polyether-based polyurethane sealing material whose deterioration has been accelerated by the accelerated deterioration method according to claim 1 or 2 is evaluated.   The deterioration evaluation method for a sealing material according to claim 3, wherein the deterioration of the sealing material is evaluated using a pyrolysis gas chromatography method.   The deterioration evaluation method for a sealing material according to claim 3, wherein the deterioration of the sealing material is evaluated by using pyrolysis gas chromatography / mass spectrometry.   The deterioration evaluation method for a sealing material according to any one of claims 3 to 5, wherein the deterioration of the sealing material is evaluated by measuring a change in the amount of the thermal decomposition product derived from the polyether part.

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