JP2013024663A - Method for calculating patience time of exterior sealant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly accurate method for calculating patience time of a sealant.SOLUTION: There is provided a method for calculating patience time of an exterior sealant which includes: (1) performing accelerated degradation of a plurality of samples with the same composition as that of a sealant to be used as a calculation object by an accelerated degradation method; (2) calculating relation between accelerated degradation time t and a degradation degree d by a degradation degree evaluation method; (3) determining a relational expression between the accelerated degradation time t and the degradation degree d; (4) calculating accelerated degradation time tcorresponding to a degradation degree din a preset patience limit; (5) measuring a degradation degree dof an exterior sealant to be used as the calculation object in actual degradation time Tby the degradation degree evaluation method, and calculating accelerated degradation time tcorresponding to the degradation degree by using the relational expression; (6) calculating acceleration magnification N of an accelerated degradation test by the actual degradation time and the accelerated degradation time; and (7) calculating patience time Tof the exterior sealant to be used as the calculation object by accelerated degradation time tand the acceleration magnification N in the patience limit and the acceleration magnification N.

Description

  The present invention relates to a method for calculating the service life of an exterior sealing material used for an exterior of a building or the like.

Against the backdrop of population decline, declining birthrate and aging population, and environmental problems, efforts are being made in many ways to ensure a long life for the housing. As one of the representative initiatives, the Long-term Excellent Housing Promotion Law was enacted in 2009. In this context, there is a need for planned maintenance of materials that need to be renewed within the useful life of the house.
Architectural sealants are also subject to planned maintenance and maintenance, but it is difficult to accurately calculate the actual service life with the conventional evaluation methods for architectural sealants. In addition, in order to accurately calculate the service life, a highly accurate deterioration diagnosis method is required, but it is difficult to accurately measure with the conventional deterioration diagnosis method.

As a method for calculating the useful life of building materials and a method for diagnosing deterioration, for example, “Revised Building Sealing Materials: Basics and Correct Usage” (March 2002 edition) issued by the Japan Sealing Industry Association There is technology disclosed in “1.3.1 Lifetime of sealing joints”. This is a method of calculating by considering factors such as materials, adherends, and construction as factors in the service life based on 10 years.
For example, in terms of materials, one-component polyurethane sealants are grouped by material type, but even in the category of one-component polyurethane sealants, the durability depends on the type and amount of compounding material and urethane resin. I know it ’s very different. (Reference: Summary of Academic Lectures of the Architectural Institute of Japan, 2009, No. 1025 “Study on Weather Resistance of Architectural Sealing Materials”
That is, although the conventional method is a simple method for calculating the service life, there is a problem that the accuracy is low.

Moreover, there exists a technique disclosed by patent document 1 as a degradation diagnostic method. However, in the technique of Patent Document 1,
1. It is a technique for detecting deterioration early, and its correlation with service life is not disclosed.
2. It is a method of observing the morphology of the surface layer and analyzing the composition, and the internal information is unknown.
There is a problem.
That is, in the technique of Patent Document 1, since the relationship between deterioration and service life is unclear, the service life cannot be measured as it is. Moreover, the state of the whole material is inferred only by the information on the surface of the building material, and cannot be applied when there is no correlation between the surface and the internal deterioration.

For example, when the surface layer of the exterior sealing material has deteriorated significantly compared to the inside due to sunlight or rain and wind, the deterioration may be estimated to be high even if the actual layer has sufficient performance. In that case, an accurate service life cannot be estimated, and there is a high possibility of being economically disadvantageous.
On the other hand, when the inside is significantly deteriorated compared to the surface layer due to a transfer substance from the adherend, there is a risk that the deterioration is estimated to be low.

JP 2002-350326 A

This invention is made | formed in view of the said situation, and it aims at providing the calculation method of the lifetime of the exterior sealing material which can eliminate the said malfunction at least partially.
In particular, an object of the present invention is to provide a highly accurate method for calculating the service life of a sealing material.

The calculation method of the service life of the exterior sealing material according to the present invention is as follows:
(1) a step of accelerating and degrading a plurality of samples having the same composition as the exterior sealing material to be calculated by a predetermined accelerating degradation method;
(2) obtaining a relationship between the accelerated deterioration time t and the deterioration degree d by the deterioration degree evaluation method based on a chemical change for the plurality of samples;
(3) determining a relational expression between the accelerated deterioration time t and the deterioration degree d based on the result of the step (2);
(4) by using the equation, and determining the accelerated aging time t _L corresponding to the deterioration degree d _L in preset life limit,
(5) The deterioration degree d ₁ of the exterior sealing material to be calculated in the actual deterioration time T ₁ is measured by the deterioration degree evaluation method, and the promotion corresponding to the deterioration degree d ₁ is performed using the relational expression. Determining a degradation time t ₁ ;
(6) A step of obtaining an acceleration factor N (N = T ₁ / t ₁ ) of the accelerated deterioration test from the actual deterioration time T ₁ and the accelerated deterioration time t ₁ ;
(7) A step of obtaining a useful time T _L (T _L = t _L × N) of the exterior sealing material to be calculated from the accelerated deterioration time t _L and the accelerated magnification N at the service life limit;
including.

  In one aspect of the present invention, the chemical change in the degradation degree evaluation method is a change in the amount of a substance whose generation amount increases or decreases with the progress of deterioration of the exterior sealing material over time. .

  In one aspect of the present invention, the exterior sealing material contains a polyether, and the deterioration evaluation method is based on measurement of a change in the amount of thermal decomposition products derived from the polyether portion of the exterior sealing material.

In one aspect of the present invention, the polyether is a polyether polyol.

  In one aspect of the present invention, the sealing material containing the polyether contains polyether triol, and the thermal decomposition product derived from the polyether part is diisopropyl ether.

  In one aspect of the present invention, the change in the amount of the pyrolysis product is measured by pyrolysis gas chromatography.

  In one aspect of the present invention, the change in the amount of pyrolysis product is measured by pyrolysis gas chromatography and mass spectrometry.

  In one aspect of the present invention, the accelerated deterioration method is characterized in that the deterioration is advanced by placing the plurality of samples in a temperature range of 70 ° C. to 90 ° C. and a humidity range of 0 to 10% RH.

  ADVANTAGE OF THE INVENTION According to this invention, the durable time calculation method of the sealing material for exteriors with high precision can be provided.

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. It is the figure which represented the step which calculates lifetime for the graph by a degradation degree and time. The pyrograms (retention time: 0 minutes to 10 minutes) of the sample before the accelerated deterioration test (0 hour) and the sample after the accelerated deterioration test of 10,000 hours are shown. In the figure, peak 1 is diisopropyl ether and peak 2 is 4-isopropoxy-2-butanone. The sample before the accelerated deterioration test (0 hour) and the sample after the accelerated deterioration test of 2000 hours, 4000 hours, 6000 hours, 8000 hours, and 10,000 hours were measured by pyrolysis gas chromatography. Calculate the area ratio of each peak of diisopropyl ether and 4-isopropoxy-2-butanone relative to the area of all the peaks of diisopropyl ether and 4-isopropoxy-2-butanone when the pre-accelerated deterioration is set to 1. The change of the area ratio is shown. Using a sealing material of the same composition as that of the sample subjected to the accelerated deterioration test, the sealing material collected from the south surface of the building after 5 years, 6 years, 11 years, and 14 years has been measured 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. It is the figure which represented the data of diisopropyl ether of FIG. 4 and FIG. 5 on the same graph by making acceleration magnification into about 16 times.

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

  Below, based on embodiment, the calculation method of the lifetime of the sealing material for exteriors (henceforth only a sealing material) which concerns on this invention is demonstrated, However, These embodiment is in order to help an understanding of this invention. The description is not intended to limit the invention to the described embodiments.

The sealing material targeted by the present invention is a sealing material containing polyether.
The calculation method of the service life of the sealing material according to the present embodiment includes the following steps.
(1) A step of accelerating and degrading a plurality of samples having the same composition as the sealing material to be calculated by a predetermined accelerating degradation method.
(2) A step of obtaining a relationship between the accelerated deterioration time t and the deterioration degree d by the deterioration degree evaluation method based on a chemical change for the plurality of samples.
(3) A step of determining a relational expression between the accelerated deterioration time t and the deterioration degree d based on the result of the step (2).
(4) using the above relationship to determine the accelerated aging time t _L corresponding to the deterioration degree d _L in preset service limit step.
(5) by the deterioration degree evaluation method, the deterioration degree d ₁ of exterior sealant to be the calculation and measurement at the actual degradation time T _1, corresponding to the deterioration degree d ₁ using the above relational expression promoting determining the degradation time _{t 1.}
(6) A step of obtaining an acceleration magnification N (N = T ₁ / t ₁ ) of the accelerated deterioration test from the actual deterioration time T ₁ and the accelerated deterioration time t ₁ .
(7) A step of obtaining a useful time T _L (T _L = t _L × N) of the exterior sealing material to be calculated from the accelerated deterioration time t _L and the accelerated magnification N at the service life limit.

Below, each said step is demonstrated.
In the step (1), a plurality of samples having the same composition as the sealing material to be calculated are accelerated and deteriorated by a predetermined accelerated deterioration method.

Applicant accurately reproduces 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 a polyether-containing sealing material. It has been found that an accelerated deterioration method can be obtained in which the correlation with deterioration due to outdoor exposure is extremely high.
That is, the sealing material containing polyether is generally known that the polyether portion of the soft segment undergoes a thermal oxidation reaction or hydrolysis reaction, but the applicant suppresses the hydrolysis reaction as much as possible, It was clarified that an appropriate thermal oxidation reaction is particularly important to reproduce the deterioration of the sealant due to outdoor exposure.

 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 enabling outdoor exposure to be reproduced in a short period of time. I found out. 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 applicant effectively removes plasticizers and additives that bleed out on the surface of the sealing material, and keeps the surface state of the sealing material constant. I found it necessary. This is because the diffusion rate of the plasticizer or additive in the surface direction needs to be kept constant. In order to keep the surface state of the sealing material sample constant, it is preferable to provide an absorbent body or an adsorbent body on the surface that can remove the plasticizer and additives that bleed out on the surface of the sealing material. 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 Can 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.

  As described above, the case where the exterior coating film is not provided on the surface of the sealing material has been described. However, the present accelerated deterioration method can be similarly applied to the non-direct exposure type sealing material provided with the exterior coating film on the surface of the sealing material. . In addition, when the non-direct exposure type sealing material is accelerated and deteriorated by this accelerated deterioration method, the above absorber or adsorbent may or may not be present, but bleed-out materials such as additives are efficiently removed from the sample surface. In order to remove, it is preferable to provide an absorber or an adsorbent.

  In the step (2), the relationship between the accelerated deterioration time t and the deterioration degree d is obtained for the plurality of samples by a deterioration degree evaluation method based on chemical change, and the deterioration degree is quantified.

  The chemical change in the degradation degree evaluation method is a change in the amount of a substance that increases or decreases with the progress of deterioration of the sealing material over time.

 The applicant does not evaluate the appearance or physical properties of the sealant, but the degree of change in the composition of a specific component of the sealant, specifically, the heat from the polyether part of the sealant containing the polyether. We succeeded in estimating the degree of deterioration of the sealing material by measuring the decomposition products.

 Conventionally, many of the sealing materials used for sealing materials for outdoor buildings have a three-dimensional cross-linking structure, the composition is extremely complicated, and many kinds of additives are blended, so it deteriorates. It was considered extremely difficult to analyze the sealing material itself and evaluate the degree of deterioration. However, as a result of diligent research, the applicant has determined that a certain pyrolysis condition is set, and a specific pyrolysis product derived from the polyether portion is generated regardless of the additives contained in the sealing material, and the heat It has been found that the amount of decomposition products increases approximately in proportion to the deterioration of the sealing material.

 In the degradation degree evaluation method described above, degradation of the sealing material containing polyether is measured by measuring the amount of pyrolysis product derived from the polyether part, for example, the composition ratio of the gas chromatogram, using pyrolysis gas chromatography. Estimate the degree. According to such a method, since the sealing material containing the deteriorated polyether can be directly applied to the analysis sample as it is without performing pretreatment, it is possible to evaluate the degree of deterioration with high accuracy.

  In addition, after qualitative analysis by pyrolysis gas chromatography mass spectrometry (analysis method that performs pyrolysis gas chromatography and mass spectrometry in succession) or at the same time, it contains polyether. Even if the types of the monomer components and additives constituting the sealing material are not known, it is possible to accurately evaluate the degree of deterioration.

  Sealing materials containing polyether usually contain a plasticizer in addition to the resin containing the polyether in the molecule, and further include a heat stabilizer, an ultraviolet absorber, a light stabilizer, an antioxidant, and an algaeproof agent. , Antifungal agents, antifoaming agents, thickeners, dispersants, fillers, pigments and the like are contained as appropriate.

  As long as the sealing material containing polyether contains polyether in the molecule, it may contain polyether in the main chain or as a pendant chain. And polyether-based polyurethane, polyether-modified silicone, polyether-modified polysulfide, and particularly polyether-based polyurethane.

  Hereinafter, a typical polyether-based polyurethane will be described. This 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 hydroxyphenyl triazine compound, and the light stabilizer includes a hindered amine compound.

  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 containing polyether was calculated by calculating the composition ratio of the gas chromatogram of the pyrolysis product derived from the polyether part of the sealing material containing polyether by using pyrolysis gas chromatography for the sampled sample. Evaluation is made by observing the change of the numerical value over time. The degree of deterioration is estimated by utilizing the phenomenon that the composition ratio of the thermal decomposition product derived from the polyether portion increases with the deterioration of the sealing material containing the polyether.

  Here, the “composition ratio of the thermal decomposition product derived from the polyether portion of the sealing material containing polyether” means the polyether with respect to the total thermal decomposition product generated by pyrolyzing the sealing material containing polyether. It means the content ratio of a specific pyrolysis product derived from part. 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 above method, the sample for evaluating the degree of deterioration of the sealing material containing the polyether may be several mg, for example, and at least about 0.01 mg can be evaluated. Therefore, even when diagnosing the deterioration of the sealing material of an aged building, the sample can be easily collected with minimal damage to the building, for example, 0.01 to 1.0 mg is accurately weighed, It can use for a measurement sample. Therefore, in order to improve the reproducibility of the measurement, it is preferable to use the same amount of sample each time in the range of 0.3 to 0.5 mg.

  In addition, in the sealing material, in addition to a plasticizer, usually a heat stabilizer, an ultraviolet absorber, a light stabilizer, an antioxidant, an algae-proofing agent, an antifungal agent, an antifoaming agent, a thickener, a dispersant, Various additives such as fillers and pigments are included, but even if they are present, there is no problem in the evaluation of the deterioration degree of the sealing material.

  In the method of the present invention, since pyrolysis gas chromatography is used as an analysis method, it is possible to perform highly sensitive and highly accurate measurement even in a solid state 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 kind of the sealing material containing the polyether, and is usually preferably 400 ° C. to 700 ° C. If the temperature is lower than 400 ° C., the decomposition of the sealing material containing the polyether hardly occurs. The analysis cannot be performed, and at temperatures higher than 700 ° C., the decomposition of the sealing material and the additive containing the polyether proceeds so much that a large amount of unnecessary components are produced, making it difficult to determine. 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 at the time of heating, the sealing material containing the polyether 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 sample to be analyzed is input to 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. A gas generated by heating and decomposing the 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.

  In such pyrolysis gas chromatography mass spectrometry, qualitative analysis of samples is possible, not only a sealing material resin containing polyether, but also a plasticizer, a hindered phenol thermal stabilizer, a hindered amine light stabilizer (HALS). ) And qualitative and quantitative analysis of additives such as ultraviolet absorbers (UVA). Therefore, it is also possible to know the remaining amount of hindered phenol heat stabilizer, HALS and UVA of the sealing material containing the deteriorated polyether. The stabilizing effect of heat stabilizers, HALS and UVA, or the effect of such additives on the weather resistance of a sealing material containing polyether can be confirmed.

  In the step (3), a relational expression between the accelerated deterioration time t and the deterioration degree d is determined based on the result of the deterioration degree evaluation method. The relational expression is obtained by regression analysis such as a least square method using the relationship between the accelerated deterioration time and the deterioration degree of a plurality of samples.

In the step (4), an accelerated deterioration time t _L (limit deterioration time) corresponding to a deterioration degree d _L (limit deterioration degree) at an end-of-life limit set in advance is obtained using the relational expression.
Here, the service life limit arbitrarily set in advance is set based on any condition such as loss of aesthetics or deterioration of waterproofness. For example, if it is known that the waterproofness of the sealing material is significantly impaired at a certain degree of deterioration and needs to be replaced, this is set as the service life limit.

  The relational expression is not limited to a linear expression, but the relation between the accelerated deterioration time t and the deterioration degree d may be represented by a straight line (deterioration straight line) as shown in FIG. The durability classification can also be obtained from the slope of this deterioration line. Further, when the deterioration changes linearly, the service life can be estimated even for a sample of a relatively shallow building (several years).

In the step (5) above, the seal material, which is the target of calculating the service life, collected from the actual building _whose age is known (the actual degradation time T1 _is known) is actually measured using the above degradation degree evaluation method. The degree of degradation d ₁ at the degradation time T ₁ is measured. Then, an accelerated deterioration time t ₁ corresponding to the deterioration degree d ₁ is obtained using the above relational expression.

Here, the sealing material to measure the deterioration degree d ₁ is preferably taken from the south side of the building. Since the south side of the building is stably exposed to sunlight, there is an advantage that the deterioration proceeds more than the other side and the result on the safe side is obtained.

In the step (6), the acceleration rate N (N = T ₁ / t ₁ ) of the accelerated deterioration test is obtained from the actual deterioration time T ₁ and the accelerated deterioration time t ₁ obtained by the above relational expression.

In the step (7), the service life time T _L (T _L = t _L × N) of the sealing material to be used for service life calculation is obtained from the accelerated deterioration time t _L at the service life limit and the acceleration magnification N.
The remaining life of the sealing material can also be obtained from the difference between the service life and the actual deterioration time of the sealing material (the age of the building).

  Since the calculation method of the service life of the exterior sealing material according to the present embodiment can be evaluated with a minute amount of about 1 mg, building damage can be minimized. In addition, it is advantageous that the time required for quantification is as short as several hours.

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 sample of the sealing material before the accelerated deterioration test was analyzed by pyrolysis gas chromatography to obtain a pyrogram (0 hr in FIG. 3). 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. Then, a pyrogram was obtained for each sample (only a sealing sample subjected to a 10,000 hour accelerated deterioration test is shown in FIG. 3).
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.

 4 and 5, in the case of diisopropyl ether, accelerated degradation test time of 550 hours corresponds to almost one year of actual exposure (exposure by actual aged buildings), and in the case of 4-isopropoxy-2-butanone The accelerated degradation test time of 610 hours was found to correspond to almost one year of actual exposure (exposure with 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.

  FIG. 6 is a graph showing the relationship between the degree of accelerated deterioration of the sealing material by the accelerated deterioration method and the accelerated deterioration time (accelerated magnification: about 16 times), and the actual aging of the sealing material. The straight line in the graph is a straight line that satisfies the relationship calculated from the degree of accelerated deterioration by the accelerated deterioration method and the accelerated deterioration time.

As described above, the method of calculating the service life of the exterior sealing material of the present invention can provide a highly accurate method of calculating the service life of the sealant.
Moreover, the calculation method of the lifetime of the exterior sealing material according to the present invention can be applied not only to the evaluation of building sealing materials but also the sealing materials for fixing car window glass.

Claims (8)

(1) a step of accelerating and degrading a plurality of samples having the same composition as the exterior sealing material to be calculated by a predetermined accelerating degradation method;
(2) obtaining a relationship between the accelerated deterioration time t and the deterioration degree d by the deterioration degree evaluation method based on a chemical change for the plurality of samples;
(3) determining a relational expression between the accelerated deterioration time t and the deterioration degree d based on the result of the step (2);
(4) by using the equation, and determining the accelerated aging time t _L corresponding to the deterioration degree d _L in preset life limit,
(5) The deterioration degree d ₁ of the exterior sealing material to be calculated in the actual deterioration time T ₁ is measured by the deterioration degree evaluation method, and the promotion corresponding to the deterioration degree d ₁ is performed using the relational expression. Determining a degradation time t ₁ ;
(6) A step of obtaining an acceleration factor N (N = T ₁ / t ₁ ) of the accelerated deterioration test from the actual deterioration time T ₁ and the accelerated deterioration time t ₁ ;
(7) A step of obtaining a useful time T _L (T _L = t _L × N) of the exterior sealing material to be calculated from the accelerated deterioration time t _L and the accelerated magnification N at the service life limit;
A method for calculating the service life of an exterior sealant, characterized by comprising: The chemical change in the deterioration evaluation method is a change in the amount of a substance that increases or decreases with the progress of deterioration of the exterior sealing material over time. The calculation method of the service life of the exterior sealing material according to 1. The exterior sealing material contains a polyether, and the deterioration evaluation method is based on measurement of a change in the amount of thermal decomposition products derived from the polyether portion of the exterior sealing material. The calculation method of the service life of the exterior sealing material according to 2. The said polyether is polyether polyol, The calculation method of the lifetime of the sealing material for exterior | packing of Claim 3 characterized by the above-mentioned. The said polyether contains polyether triol and the thermal decomposition product derived from the said polyether part is diisopropyl ether, The calculation method of the lifetime of the sealing material for exterior | packing of Claim 3 characterized by the above-mentioned. The method for calculating the service life of an exterior sealing material according to claim 3 or 4, wherein the change in the amount of the pyrolysis product is measured by pyrolysis gas chromatography. The method for calculating the service life of an exterior sealant according to claim 3 or 4, wherein the change in the amount of the pyrolysis product is measured by pyrolysis gas chromatography and mass spectrometry. 8. The accelerated deterioration method according to claim 2, wherein the deterioration of the sealing material is caused to progress by placing the sealing material under conditions of a temperature range of 70 ° C. to 90 ° C. and a humidity range of 0 to 10% RH. A method of calculating the service life of the exterior sealing material according to any one of the above.