JP2010085117A - Method for diagnosing resin-molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diagnostic method that can simply and accurately diagnose the deterioration degree of mechanical properties of a resin molded product subjected to outdoor exposure and determine the appropriate timing for repairing or replacement. <P>SOLUTION: The method for diagnosing a resin-molded product diagnoses the deterioration degree of a resin molded product 20, by estimating mechanical properties of the resin molded product 20 that is made of a second resin material and protected by a surface layer 10, made of a first resin material containing an ultraviolet absorber. The method includes an acquisition process for acquiring calibration curve data, showing the relationship between ultraviolet ray transmittance of a resin composition and mechanical properties of a test piece wherein an evaluation sample is the test piece that is made of the second resin material and protected by the resin composition that is made of a resin material of the same or of a different type as the first resin material and contains the ultraviolet absorber of the same or different type as the first resin material; a measurement process for determining ultraviolet ray transmittance of the surface layer 10; and a diagnostic process for estimating mechanical properties of the resin molded product 20 from the measured ultraviolet-ray transmittance of the surface layer 10 and the calibration curve data. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a diagnostic method for diagnosing the presence or absence of deterioration over time of a resin molded product.

  In recent years, resin materials have been widely used as structural members in outdoor exposure environments, for example, building materials such as roofs, exterior materials for automobiles, and civil engineering materials such as sound insulation walls. Even if the resin material is well maintained, the progress of aging is unavoidable, and from the viewpoint of safety against declining durability and aesthetics, it is necessary to repair or replace the aging resin material. Generally, resin materials deteriorate and harden when exposed to sunlight or wind and rain. The cured resin material is deteriorated in properties such as tensile elongation, tensile strength and transparency. The resin material that has further deteriorated is yellowed and progressed, and the impact resistance is reduced, so that the resin material is easily damaged by wind and rain or collision of foreign matter.

  Here, from the viewpoint of reducing the environmental load, it is required to appropriately diagnose the degree of deterioration of the resin material and repair or replace it at a suitable timing.

For this type of diagnostic technique, the following direct method and indirect method are conventionally known.
As a direct method, for example, a method is known in which a constructed resin material is removed, a test piece for measurement is cut out, and a physical property test such as a mechanical property test is performed.

As an indirect method, a method is known in which appearance changes such as yellowing and gloss of a resin material are inspected, and the degree of deterioration of the resin material is judged from the degree of yellowing and glossiness increase. .
Patent Document 1 listed below describes a method of measuring the propagation speed of ultrasonic waves in a resin material and judging the degree of deterioration of the resin material from the degree of decrease in the speed.
In Patent Document 2 below, the absorption spectrum of the coating is measured, the ratio of the absorbance derived from the coating component to the absorbance derived from the component of the resin molded product is measured, and the functional group of the coating component in the coating is measured. A method for determining the ratio between the amount and the functional group amount of the component of the resin molded product is described.

JP-A-11-352050 JP 2002-22648 A

However, since the direct diagnosis method described above is a destructive inspection of a resin material, even if the resin material from which the test piece is cut out is not deteriorated, there is a problem that it is necessary to replace it after diagnosis. .
In addition, among indirect diagnostic methods, in the case of visual inspection for observing yellowing, gloss, etc., there are large factors of variation due to the installation environment of the resin material. There is a problem that the accuracy of predicting the degree of deterioration of the mechanical characteristics from the inspection result is not high. In addition, since the mechanical properties of the resin material are generally already considerably degraded when yellowing or gloss is confirmed, there is a problem that the degradation of the resin material cannot be safely predicted in advance.

  Further, in the case of the diagnostic method described in Patent Document 1, since the propagation speed of ultrasonic waves greatly varies depending on the hardness of the resin and the influence of measurement error increases, the degree of decrease in the propagation speed is accurately determined. This is difficult and the diagnostic accuracy is not high.

  Further, the diagnostic method described in Patent Document 2 predicts the weather resistance of a resin molded product, and does not diagnose the degree of deterioration of a resin molded product actually used in an outdoor exposure environment. Therefore, with this method, it is impossible to individually diagnose the degree of deterioration of resin molded products that have been exposed to wind and rain and ultraviolet rays in various environments over a long period of time, and determine the appropriate timing for repairs and replacements. There is a problem that you can not.

  The present invention has been made in view of the above problems, and can easily and accurately diagnose the degree of deterioration of mechanical properties of a resin molded product exposed outdoors, and can determine the appropriate timing for repair or replacement. A method is provided.

According to the present invention, the degree of deterioration of the resin molded product is diagnosed by estimating the mechanical properties of the resin molded product made of the second resin material protected by the surface layer made of the first resin material containing the ultraviolet absorber. A way to
A test piece made of the second resin material, which is made of the same or different kind of resin material as the first resin material and protected by a resin composition containing the same or different kind of ultraviolet absorbent as the ultraviolet absorbent, is used as an evaluation sample. An acquisition step of acquiring calibration curve data indicating a relationship between the ultraviolet transmittance of the resin composition and the mechanical properties of the test piece;
A measuring step for determining the ultraviolet light transmitting ability of the surface layer;
From the measured ultraviolet transmittance of the surface layer and the calibration curve data, a diagnostic step of estimating the mechanical properties of the resin molded product,
A method for diagnosing a resin molded article containing the above is provided.

As the ultraviolet ray transmitting ability, typically, ultraviolet ray transmittance, ultraviolet ray absorbance, or ultraviolet absorber concentration can be used. In addition, the transmittance | permeability of an ultraviolet-ray here means the transmittance | permeability of the ultraviolet-ray within the degradation wavelength range of 2nd resin material so that it may mention later.
Further, the ultraviolet transmittance of the surface layer actually measured in the measurement step and the ultraviolet transmittance obtained from the resin composition in the acquisition step may be the same index or different indexes that can be converted to each other. . That is, in the measurement process, the ultraviolet ray transmission ability may be obtained by actually measuring the same index as the ultraviolet ray transmission ability constituting the calibration curve data from the surface layer, or a different index is actually measured from the surface layer and converted. Then, the ultraviolet ray transmitting ability may be obtained. For example, from a resin composition that protects a test piece, absorbance for a predetermined wavelength of ultraviolet light is acquired to obtain calibration curve data, and the maximum transmittance for ultraviolet light of a predetermined wavelength is measured for the surface layer to be diagnosed. May be. In this case, the measurement step includes a step of actually measuring the maximum transmittance of the surface layer and a step of converting the actually measured maximum transmittance into absorbance.

  Further, in the method for diagnosing a resin molded article according to the present invention, as a more specific aspect, in the acquisition step, the ultraviolet ray transmitting ability relating to the resin composition and the mechanical characteristics relating to the test piece, both of which are exposed to ultraviolet rays. The calibration curve data may be acquired in association with each time of ultraviolet exposure.

  Here, regarding the calibration curve data, the acquisition timing for each UV exposure time related to the UV transmittance of the resin composition and the acquisition timing for each UV exposure time related to the mechanical properties of the test piece may be common or different from each other. Good. Moreover, the resin composition from which the ultraviolet ray transmission ability is acquired and the test piece do not need to be subjected to ultraviolet ray exposure at the same time. That is, a resin composition that is used for acquisition of ultraviolet transmittance and a resin composition that protects a test piece from which mechanical properties are acquired may be provided separately. In addition, ultraviolet exposure may be performed by direct outdoor exposure or artificially accelerated exposure.

  Moreover, in the method for diagnosing a resin molded product according to the present invention, as a more specific aspect, in the diagnostic step, when the ultraviolet transmittance of the surface layer belongs to a preset degradation region, the resin molded product The product may be diagnosed as being in a degraded state.

  Here, the deterioration region refers to a state in which it is estimated that the resin molded product and the surface layer to be diagnosed are exposed to ultraviolet rays, and the mechanical properties of the resin molded product are reduced below a predetermined level.

Further, in the method for diagnosing a resin molded article according to the present invention, as a more specific aspect, the ultraviolet transmittance of the resin composition drawn on the basis of the calibration curve data and the mechanical characteristics of the test piece The calibration curve showing the relationship of
The start point of the deterioration area may be set on the safe side with respect to the inflection point.
Here, the start point of the deterioration region is set to be safer than the inflection point. That is, the resin molded product is in a state before the mechanical properties of the test piece that deteriorates with time exceeds the inflection point. It means diagnosing that it is deteriorated, that is, it is time to repair or replace.

  In the method for diagnosing a resin molded product according to the present invention, as a more specific embodiment, the first resin material and the resin composition are substantially free of an inorganic filler having an ultraviolet shielding ability. Also good.

  In the method for diagnosing a resin molded product according to the present invention, as a more specific aspect, the first resin material and the resin composition may be made of different resin materials.

  In the method for diagnosing a resin molded product according to the present invention, as a more specific aspect, the ultraviolet absorbent contained in the first resin material and the ultraviolet absorbent contained in the resin composition are different. It may be a material.

  In the method for diagnosing a resin molded product according to the present invention, as a more specific aspect, the second resin material may be polycarbonate.

  The various components of the present invention including the surface layer and the resin molded product do not need to be individually independent, but a plurality of components are formed as one member, and one configuration An element is formed of a plurality of members, a certain component is a part of another component, a part of a certain component overlaps a part of another component, etc. But you can.

  Further, in explaining the method for diagnosing a resin molded product according to the present invention, a plurality of steps may be described in order, but the order of description does not necessarily limit the order in which the steps are executed, unless explicitly stated. is not. In addition, a plurality of processes are not limited to being executed at different timings unless explicitly stated, other processes may occur during execution of a certain process, execution timing of a certain process, and other timing. It may be that part or all of the process execution timing overlaps.

According to the method for diagnosing a resin molded product of the present invention, it is possible to simply and accurately diagnose the presence or absence of deterioration of a resin molded product installed outdoors and determine the appropriate timing for repair or replacement. it can. In the diagnostic method of the present invention, since the mechanical properties of the resin molded product are diagnosed from the ultraviolet ray transmitting ability of the surface layer protecting the resin molded product, the resin molded product can be inspected nondestructively.
Further, the resin composition for obtaining calibration curve data, the surface layer for protecting the resin molded product to be diagnosed, and the ultraviolet absorbers contained therein are not limited to the same type. For this reason, based on the calibration curve data acquired in advance, it is possible to diagnose the degree of deterioration of the mechanical characteristics for a large number of resin molded articles to be diagnosed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

  FIG. 1 is a schematic diagram showing a target member 30 whose degree of deterioration is diagnosed by the method for diagnosing a resin molded product according to the present embodiment.

First, an overview of the diagnostic method of the present embodiment will be described.
The diagnosis method according to the present embodiment estimates the mechanical characteristics of the resin molded product 20 made of the second resin material protected by the surface layer 10 made of the first resin material containing the ultraviolet absorber, and diagnoses the degree of deterioration. It is a method to do.
In the diagnostic method of the present embodiment, the second resin material is made of the same or different kind of resin material as the first resin material and protected by the resin composition containing the same or different kind of ultraviolet absorbent as the ultraviolet absorbent. An acquisition step of acquiring calibration curve data indicating the relationship between the ultraviolet transmittance of the resin composition and the mechanical properties of the second test piece 22, using the test piece (second test piece 22) made of And a diagnostic step of estimating mechanical properties of the resin molded product 20 from the measured ultraviolet transmittance of the surface layer 10 and calibration curve data.

Next, the diagnostic method of this embodiment will be described in detail.
<Target member>
The target member 30 shown in FIG. 5A is a diagnostic object installed in an ultraviolet exposure environment, and protects the surface of the resin molded product 20 made of the second resin material with the surface layer 10 made of the first resin material. It becomes. Of the resin molded product 20, only the surface side (upper side in the figure) on which the surface layer 10 is provided is exposed to ultraviolet rays.

The resin molded product 20 is formed by molding a second resin material made of one kind or two or more kinds of resin materials.
Examples of the second resin material include polycarbonate (PC), polymer alloy of polycarbonate (PC) and other resin materials, and polyvinyl chloride (PVC). Among these, as other resin material which comprises a polymer alloy, polyester, such as a polyethylene terephthalate (PET), can be illustrated.

In the second resin material, there is a unique degradation wavelength for each material that is easily broken by irradiation.
For example, in the case of polycarbonate, it is known that degradation is most likely when ultraviolet rays having a wavelength of 320 nm are irradiated among ultraviolet rays contained in sunlight. Hereinafter, among the ultraviolet rays contained in sunlight, the wavelength of the ultraviolet rays that most deteriorate the second resin material constituting the resin molded product 20 is referred to as a deteriorated wavelength. Such a degradation wavelength is determined based on the light absorption characteristics of the second resin material and the content ratio of the ultraviolet wavelength component in sunlight. In the present embodiment, an ultraviolet wavelength range (including the above-described degradation wavelength) that significantly degrades the second resin material is referred to as a degradation wavelength range. Hereinafter, the term “ultraviolet rays” without any notice may mean ultraviolet rays within a deterioration wavelength range with respect to the second resin material.

The surface layer 10 is a weathering layer formed on the surface of the resin molded product 20 and is made of a first resin material containing an ultraviolet absorber (UVA).
The first resin material constituting the surface layer 10 and the second resin material constituting the resin molded product 20 may be the same type of resin material or different types of resin materials.

The first resin material is an ultraviolet light transmissive resin material and does not substantially contain an inorganic filler having an ultraviolet shielding ability. As a specific first resin material, a weather-resistant resin such as an acrylic resin or polyester can be used.
In the present embodiment, the fact that the first resin material does not substantially contain the inorganic filler having ultraviolet shielding ability means that the purpose is other than ultraviolet shielding, that is, imparting heat resistance or flame retardancy, or light scattering. It is not excluded that an inorganic material is added to the first resin material for the purpose of decoration by the above.
The content of the inorganic filler having ultraviolet shielding ability is 1.0 wt% or less, preferably 0.1 wt% or less with respect to the first resin material.
By setting the content of the inorganic filler to 1.0 wt% or less, deterioration over time of the ultraviolet transmittance in the first resin material exposed to ultraviolet rays is generally significantly observed. Diagnosis can be made with high accuracy. Furthermore, by setting the content of the inorganic filler to 0.1 wt% or less, a sufficient time-dependent change width of the ultraviolet light transmission ability of the second resin material in a warning area to be described later is ensured. Can be predicted with high accuracy.

The absorption wavelength of the ultraviolet absorbent contained in the first resin material preferably includes at least the degradation wavelength of the resin molded product 20 and covers the entire degradation wavelength region.
As UV absorbers, paraaminobenzoic acid UV absorbers, anthranilic acid UV absorbers, salicylic acid UV absorbers, cinnamic acid UV absorbers, benzotriazole UV absorbers, benzophenone UV absorbers, triazine UV Those belonging to any kind selected from the group consisting of an absorber and a sugar-based ultraviolet absorber can be used.
Although the ultraviolet absorber to be used is not particularly limited, a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, or a triazine-based ultraviolet absorber is preferably used from the viewpoint of ultraviolet absorbing ability and durability.

Examples of the method for forming the surface layer 10 include the following three methods.
(1) A co-extrusion method in which the first resin material containing the ultraviolet absorber and the second resin material are co-extruded (two-layer extrusion) to integrally mold the surface layer 10 and the resin molded product 20.
(2) A sticking method in which a first resin material containing an ultraviolet absorber is formed into a thin film into a film shape, and this is attached to a pre-molded resin molded product 20.
(3) A coating method in which the first resin material is dissolved in an organic solvent or the like, an ultraviolet absorber is mixed, applied to a pre-molded resin molded product 20, and then dried and fired as necessary.

The layer thickness of the surface layer 10 is not particularly limited, but is set to a thickness that provides sufficient weather resistance over a long period of time that causes deterioration of the resin molded product 20 with time. Specifically, for example, the thickness can be about 5 to 200 μm.
On the other hand, the thickness of the resin molded product 20 serving as the base material of the target member 30 is not particularly limited, and can be set to 1 to 20 mm, for example, depending on the application. Therefore, by simple calculation, the resin molded product 20 has a thickness of 5 to 4000 times that of the surface layer 10. Among these, the mechanical strength of the target member 30 is mainly governed by the mechanical characteristics of the resin molded product 20 by setting the thickness ratio between the resin molded product 20 and the surface layer 10 to 10 times or more, preferably 100 times or more. The Rukoto. And according to the diagnostic method of this embodiment, since deterioration of the mechanical characteristic of the resin molded product 20 is estimated, estimation with high precision is also possible from the viewpoint of a decrease in the mechanical strength of the entire target member 30.

  The target member 30 installed outdoors and exposed to ultraviolet rays is irradiated with ultraviolet rays UV over a long period of time on the surface layer 10 as shown in FIG. The target member 30 at the beginning of installation is absorbed by the surface layer 10 due to the action of the ultraviolet absorber contained in the surface layer 10, and the ultraviolet rays UV within the degradation wavelength range of the resin molded product 20 are absorbed by the surface layer 10. do not do. At the beginning of outdoor installation, the absorbance of ultraviolet UV in the surface layer 10 is maximum, and the ultraviolet transmittance is substantially zero.

When a predetermined time elapses after the outdoor installation, the ultraviolet absorber is decomposed by the ultraviolet UV and volatilizes from the surface layer 10, and the ultraviolet absorbance of the surface layer 10 decreases. Then, when the ultraviolet absorbance in the surface layer 10 decreases and the ultraviolet transmittance changes from zero to positive, the ultraviolet UV irradiated to the target member 30 passes through the surface layer 10 as shown in FIG. To the resin molded product 20.
Thereafter, the resin molded product 20 gradually deteriorates in mechanical properties due to exposure to ultraviolet rays UV, and deteriorates as a whole.

<Specimen>
In the diagnosis method of this embodiment, prior to diagnosis of the target member 30, calibration curve data is acquired based on an ultraviolet exposure test of an evaluation sample. The calibration curve data is data that serves as an index for estimating the degree of deterioration of the mechanical properties of the resin molded product 20 from the ultraviolet transmittance of the surface layer 10.

2A to 2C are schematic views showing evaluation samples.
As the evaluation sample, at least a first test piece 12 that simulates the surface layer 10 and a second test piece 22 that simulates the resin molded product 20 are used.

(First specimen)
The first test piece 12 is made of the same or different resin material as the first resin material constituting the surface layer 10 of the target member 30 and is made of a resin composition containing the same or different ultraviolet absorber as the surface layer 10. . The resin material constituting the first test piece 12 has ultraviolet transparency and does not substantially contain an inorganic filler having ultraviolet shielding ability.

  Specifically, in the case of this embodiment, the surface layer 10 and the first test piece 12 are made of the same kind of resin material, and the ultraviolet absorbers contained are also common to each other.

Here, as the ultraviolet absorber contained in the first test piece 12, paraaminobenzoic acid ultraviolet absorber, anthranilic acid ultraviolet absorber, salicylic acid ultraviolet absorber, cinnamic acid ultraviolet absorber, benzophenone ultraviolet absorber Those belonging to any type selected from the group consisting of benzotriazole-based UV absorbers, triazine-based UV absorbers and sugar-based UV absorbers can be used.
From the viewpoint of the simulation accuracy of the surface layer 10 by the first test piece 12, the ultraviolet absorbent contained in the first test piece 12 and the ultraviolet absorbent contained in the surface layer 10 should be of the same type. Is preferred.

  Here, according to the study by the present inventors, the change over time in the ultraviolet transmittance of a resin material containing an ultraviolet absorber is dominated by the volatilization of the ultraviolet absorber from the resin material, and generally the resin material It has been clarified that the influence of the difference of each type of UV absorber is small. Therefore, the first test piece 12 used as an evaluation sample and the surface layer 10 used for diagnosis may be made of different resin materials, and the ultraviolet absorbers they contain are different from each other. Also good.

The same applies to the initial concentrations of the ultraviolet absorbents contained in the first test piece 12 and the surface layer 10, which may be the same or different. In addition, the initial concentration of the ultraviolet absorber related to the first test piece 12 refers to the concentration of the evaluation sample in the initial state of the ultraviolet exposure test, and the initial concentration related to the surface layer 10 refers to the concentration at the start of outdoor exposure.
The initial concentration of the ultraviolet absorber in the first test piece 12 and the surface layer 10 is sufficient so that the transmittance of the second resin material constituting the resin molded product 20 with respect to ultraviolet rays within the degradation wavelength region is substantially zero. Is preferably high. By setting the initial concentration to 1.5 to 2.0 wt%, the initial ultraviolet transmittance of the second resin material becomes 0% regardless of the type of the ultraviolet absorber.

The layer thickness of the first test piece 12 may be the same as or different from that of the surface layer 10 as long as sufficient weather resistance is obtained. In the 1st test piece 12 which does not contain an inorganic filler substantially, an ultraviolet-ray transmittance is dominantly determined by the ultraviolet absorber contained therein, and the influence by resin material itself can generally be disregarded. Therefore, the layer thickness of the first test piece 12 is not required to be equal to that of the surface layer 10.
In addition, about the content rate of the inorganic filler which the 1st test piece 12 contains, it is preferable that it is equivalent to the surface layer 10 of the target member 30 which is a diagnostic object, ie, the same order. In addition, when both the content rate of the inorganic filler which the surface layer 10 and the 1st test piece 12 contain is 1.0 wt% or less, the influence of the inorganic filler with respect to the ultraviolet-ray transmittance of the surface layer 10 and the 1st test piece 12 has an effect. The content ratios may be different from each other because they are sufficiently small.

As shown in FIG. 2A, the first test piece 12 is installed outdoors and exposed to ultraviolet rays UV at a predetermined irradiation intensity, and a pattern of change with time in ultraviolet transmittance is measured.
Various specific measurement methods can be employed, and the following three methods can be exemplified.
(1) With respect to the transmitted light of the sample of the first test piece 12 thinned to a predetermined thickness, an ultraviolet-visible spectrophotometer is measured using an ultraviolet-visible spectrophotometer, the maximum transmittance or absorbance of ultraviolet light, or the second resin Transmitted light measurement method for measuring the transmittance of ultraviolet light at the degradation wavelength of the material;
(2) With respect to the reflected ultraviolet light irradiated on the first test piece 12, an ultraviolet-visible spectrophotometer is measured using an ultraviolet-visible spectrophotometer, and the maximum transmittance or absorbance of ultraviolet light or the degradation wavelength of the second resin material is measured. Reflected light measurement method for measuring the transmittance of ultraviolet rays;
(3) Dissolve the first test piece 12 in an organic solvent to extract the UV absorber, calculate its concentration using chromatography, and convert it to the (maximum) transmittance and absorbance of UV according to (1) above. Concentration measurement method.

  In the present embodiment, the concentration of the ultraviolet absorber (absorbent concentration) is first measured using the concentration measurement method of (3) above, and this is converted into the maximum transmittance of ultraviolet rays within the deteriorated wavelength region. The ultraviolet ray transmitting ability of the test piece 12 is obtained. However, as the ultraviolet ray transmitting ability, the absorbent concentration may be used as it is instead of the maximum ultraviolet ray transmittance in the deteriorated wavelength region, or the absorbance of the deteriorated wavelength may be adopted. When the absorbance at the absorber concentration or the deteriorated wavelength is used as the ultraviolet ray transmitting ability, it is observed that the absorbance gradually decreases according to the exposure amount from the beginning of the ultraviolet exposure of the surface layer 10. For this reason, it can be said that the occurrence of deterioration of the resin molded product 20 can be grasped in advance by using the absorbent concentration and the ultraviolet absorbance instead of the maximum transmittance of ultraviolet rays.

(Second test piece)
The second test piece 22 shown in FIG. 2B is made of a second resin material, and the surface irradiated with ultraviolet rays is protected by the resin composition constituting the first test piece 12. That is, the second test piece 22 is provided with a surface protective layer 14 containing an ultraviolet absorber.

  Here, the temporal change pattern of the ultraviolet light transmission ability with respect to the surface protective layer 14 and the first test piece 12 is equal to the extent that does not significantly reduce the diagnostic accuracy of the resin molded product 20 according to the present embodiment, that is, substantially common. It is configured. For this reason, in this embodiment, the surface protective layer 14 and the first test piece 12 share the same resin composition, the type of ultraviolet absorber contained therein, and the initial concentration.

  Therefore, as shown in FIG. 2A, the first test piece 12 is used as an individual test piece for the UV exposure test, and the surface protective layer 14 corresponding to the surface layer of the laminated test piece 32 may be used as the first test piece 12. Good. That is, the ultraviolet ray exposure test is performed on the laminated test piece 32, and the surface protective layer 14 is taken as the first test piece 12 at every predetermined elapsed time to measure the ultraviolet transmittance, while the second test piece 22 is also measured. Calibration curve data may be acquired by measuring mechanical characteristics at every predetermined elapsed time.

As shown in FIG. 2B, the second test piece 22 is irradiated with ultraviolet rays UV through the surface protective layer 14, and the degree of deterioration of the mechanical properties is measured. As mechanical properties, tensile elongation or tensile strength is measured.
The measurement of the mechanical properties may be performed only for the second test piece 22 or may be performed for the laminated test piece 32 in which the second test piece 22 and the surface protective layer 14 are laminated. The mechanical characteristics of the laminated test piece 32 in which the thickness of the second test piece 22 is one digit or more larger than the thickness of the surface protective layer 14 as in this embodiment is because the mechanical characteristics of the second test piece 22 are dominant. It is.
Even when the weather resistance of the surface protective layer 14 is higher than that of the second test piece 22 and the deterioration of the surface protective layer 14 is negligible at the start of the deterioration of the second test piece 22, the tension of the second test piece 22 A decrease in elongation rate and tensile strength, that is, deterioration of the overall mechanical properties of the laminated test piece 32 is brought about.
Then, when the ultraviolet absorbance of the surface protective layer 14 decreases with time and the ultraviolet transmittance becomes positive, that is, when it becomes substantially zero, the irradiated ultraviolet UV is surface-protected as shown in FIG. It passes through the layer 14 and reaches the second test piece 22. Thereafter, the second test piece 22 starts to deteriorate due to ultraviolet irradiation, and the mechanical properties are lowered.

<Diagnosis method>
In the diagnostic method of the present embodiment, in the acquisition process, the change in the ultraviolet transmittance of the resin composition (first test piece 12, surface protective layer 14) with time and the mechanical characteristics of the second test piece 22 over time. Obtain calibration curve data that correlates with changes. Next, in the measurement process, the ultraviolet ray transmitting ability of the surface layer 10 is obtained. Then, in the diagnostic process, the mechanical properties of the resin molded product 20 are estimated from the measured ultraviolet transmittance of the surface layer 10 and calibration curve data.

(Acquisition process)
In the obtaining step, calibration curve data is obtained by associating the ultraviolet ray transmitting ability relating to the resin composition and the mechanical properties relating to the second test piece 22 that are both exposed to ultraviolet rays for each ultraviolet ray exposure time.
The calibration curve data can be calculated in advance in the form of a table, a calibration curve (graph), or a mathematical formula that associates the ultraviolet transmittance of the resin composition with the mechanical properties of the second test piece 22.
The ultraviolet transmittance of the resin composition and the mechanical properties of the second test piece 22 have a positive or negative correlation.

  And in the diagnostic method of this embodiment, after the ultraviolet ray begins to permeate through the resin composition (surface protective layer 14), that is, after the ultraviolet exposure of the second test piece 22 starts, the machine of the second test piece 22 It has been clarified by the present inventors that the characteristic takes a peculiar pattern in which the characteristic gradually decreases over a predetermined period and then drops sharply. According to the knowledge of the present inventors, the mechanical properties of many resin materials (second resin materials) that have been exposed to continuous ultraviolet rays are also rapidly abruptly irradiated with a predetermined amount of ultraviolet rays. It has become clear that

  And in this embodiment, paying attention to the time lag from when the ultraviolet transmittance of the resin composition (surface protective layer 14) turns positive, until the mechanical properties of the second test piece 22 protected by this suddenly drop, The degree of deterioration of the mechanical properties of the second test piece 22 is estimated based on the ultraviolet ray transmitting ability of the resin composition (surface protective layer 14). Thereby, the deterioration diagnosis on the safe side before the mechanical characteristic of the 2nd test piece 22 falls rapidly is enabled.

As the calibration curve data, a conversion table and a conversion formula for converting each other with respect to the ultraviolet transmittance of the surface layer 10 and the first test piece 12 or the mechanical characteristics of the second test piece 22 and the resin molded product 20 are used. You may use it in combination.
For example, calibration curve data in which the ultraviolet absorbance related to the first test piece 12 is associated with the tensile elongation rate related to the second test piece 22 is calculated, and based on the ultraviolet transmittance actually measured from the surface layer 10 of the target member 30. The tensile elongation rate and tensile strength of the resin molded product 20 may be estimated. This is because the ultraviolet transmittance and ultraviolet absorbance, and the tensile elongation and tensile strength can be converted with a predetermined accuracy.

(Measurement process)
In the measurement process, the ultraviolet ray transmitting ability of the surface layer 10 is obtained. Specifically, in the same manner as the first test piece 12, the resin molded product 20 (second resin material) is obtained as the ultraviolet transmittance of the surface layer 10 by the above-described transmitted light measurement method, reflected light measurement method, concentration measurement method, or the like. ) Is measured for the absorbance, ultraviolet transmittance or absorbent concentration with respect to ultraviolet rays within the degradation wavelength range.
Then, whether the resin molded product 20 is in a deteriorated state after converting the actually measured ultraviolet transmittance of the surface layer 10 into an index value of the calibration curve (in the case of the present embodiment, the maximum transmittance) as necessary. Diagnose whether or not.

  It should be noted that the absorbance of the ultraviolet rays and the absorbent concentration gradually decrease from the start of outdoor exposure. On the other hand, the ultraviolet transmittance of the surface layer 10 remains substantially zero while the absorbance and the absorbent concentration are sufficiently high. Then, when the absorbance becomes less than or equal to the predetermined value, the ultraviolet transmittance turns positive. When the absorbance or the absorbent concentration is measured, it can be converted into the ultraviolet transmittance by a known method. In the case where the ultraviolet transmittance is not zero, the absorbance can be converted by a known method from the measured value of the ultraviolet transmittance.

(Diagnosis process)
In the diagnosis step, when the ultraviolet ray transmitting ability of the surface layer 10 belongs to a preset degradation region, it is diagnosed that the resin molded product 20 is in a degraded state. Specifically, the starting point corresponding to the lower limit value of the degradation region of the resin molded product 20 is set in advance with respect to the calibration curve, and the magnitude relationship between the ultraviolet ray transmitting ability of the surface layer 10 and the starting point obtained in the measurement process. Thus, it is diagnosed whether or not the resin molded product 20 is in a considerably deteriorated state.

  The starting point of the degradation region can be set from various viewpoints with respect to the calibration curve data.

  Further, in the diagnosis process, in addition to the life region in which the resin molded product 20 is considerably deteriorated and needs to be repaired or collected, the warning region and A safety area may be provided. For example, the safe region can be determined while the maximum transmittance of ultraviolet rays in the surface layer 10 is zero. Then, it is possible to determine the warning area from the start of the ultraviolet irradiation to the resin molded product 20 to the start point of the deteriorated state.

Hereinafter, the present invention will be described based on examples.
<Aging change of UV absorber>
A laminated test piece 32 shown in FIG. 2B was prepared, and an outdoor exposure test was performed based on method A (direct exposure) of JIS K7219.
Polycarbonate was used as the second resin material constituting the second test piece 22 as an evaluation sample. As the surface protective layer 14 for covering the surface of the second test piece 22, a resin composition obtained by mixing an ultraviolet absorber at a concentration of 1.5 to 2.0 wt% with respect to the acrylic resin material was used. The thickness of the surface protective layer 14 was 0.05 mm, and the thickness of the second test piece 22 was 5 mm.

  As the ultraviolet absorber, a total of three types of two types of benzotriazole type ultraviolet absorbers and triazine type ultraviolet absorbers were used. All of these ultraviolet absorbers are commercially available.

  FIG. 3 is a graph with the horizontal axis representing the elapsed time from the start of UV exposure and the vertical axis representing the residual concentration (retention rate) when the initial concentration of the UV absorber is 100%. The elapsed period is standardized. From the figure, it can be seen that the UV absorbers have different rates of decrease depending on the type.

<Aging change of tensile elongation of laminated specimen>
FIG. 4 is a graph showing the secular change of the elongation of the laminated test piece 32 in which the second test piece 22 is covered with the surface protective layer 14 containing the above three kinds of ultraviolet absorbers. The horizontal axis is the normalized elapsed time from the start of UV exposure, and the vertical axis is the tensile elongation retention when the initial tensile elongation is 100%.
In addition, the measurement of the tensile elongation rate was performed based on JIS K7162.

  From this result, even when different UV absorbers are used, the tensile elongation of the laminated test piece 32 is consistent with the tendency to rapidly decrease across the inflection point as a result of the lapse of a predetermined year. I understood.

  Since the tensile rigidity of the surface protective layer 14 is negligible with respect to the second test piece 22, the decrease in the tensile elongation rate of the laminated test piece 32, that is, the decrease in the tensile elongation rate of the second test piece 22. Means.

  However, as shown in FIG. 4, the number of years that have reached the inflection point related to the tensile strength of the second test piece 22 differs depending on the type of the ultraviolet absorber.

<Relationship between tensile elongation of laminated specimen and UV transmittance>
On the other hand, by plotting the relationship between the ultraviolet light transmission ability of the surface protective layer 14 and the tensile elongation rate of the laminated test piece 32, the influence on the diagnosis result due to the difference in the type of the ultraviolet absorbent can be eliminated. In other words, the characteristic diagram regarding the ultraviolet light transmission ability by the surface protective layer 14 and the tensile elongation rate of the laminated specimen 32 is linear (calibration curve).

  FIG. 5 is a graph of a calibration curve in which the horizontal axis represents the ultraviolet transmittance of the surface protective layer 14 and the vertical axis represents the tensile elongation retention rate of the laminated test piece 32. In the figure, the test results regarding the above three kinds of ultraviolet absorbers are integrated and plotted, and the calibration curve is drawn together.

  From these results, it was found that both the ultraviolet light transmission ability by the surface protective layer 14 and the tensile elongation rate of the laminated test piece 32 had a high correlation regardless of the type of the ultraviolet absorber. Moreover, it turned out that the tensile elongation rate of the lamination | stacking test piece 32 falls rapidly regardless of the kind of ultraviolet absorber because the surface protective layer 14 straddles predetermined ultraviolet-ray transmittance.

  Specifically, as shown in FIG. 5, when the ultraviolet transmittance of the surface protective layer 14 exceeded 10 to 20%, the tensile elongation rate of the laminated test piece 32 rapidly decreased.

  As described above, the calibration curve is obtained in advance by obtaining the correlation with the tensile elongation rate of the laminated test piece 32 or the second test piece 22 using the ultraviolet ray transmittance such as the ultraviolet ray transmittance of the surface protective layer 14 as an index. As a result, deterioration diagnosis can be performed even for a diagnosis target whose initial concentration of the ultraviolet absorber is unknown.

<Diagnosis of construction products>
FIG. 6 shows a calibration curve obtained by performing an outdoor exposure test on the above-described laminated test piece 32 based on JIS K7219 A method (direct exposure), and a construction product installed outdoors with different UV exposure environments. It is the graph which plotted the measurement result regarding a certain 10 types of object member 30. FIG.
The horizontal axis represents the ultraviolet transmittance of the surface protective layer 14 or the surface layer 10, and the vertical axis represents the tensile elongation retention rate of the second test piece 22 or the resin molded product 20.

  The target member 30 is common to the laminated test piece 32 in that polycarbonate is used for the resin molded product 20 as a base material. The tensile elongation retention rate of the resin molded product 20 is obtained by dividing the tensile elongation value measured from the construction product based on JIS K7162 by the initial state of the polycarbonate.

In addition, the thickness of the surface layer 10 is 200 μm or less, and is common to the laminated test piece 32 in that the tensile rigidity can be ignored with respect to the mechanical characteristics of the target member 30.
Moreover, the classification of the ultraviolet absorber contained in the surface layer 10 of the target member 30 is different for each target member 30 that is a construction product.

The calibration curve shown in FIG. 6 has an inflection point IP when the ultraviolet transmittance is about 35%.
And the ultraviolet transmittance measured from 10 kinds of construction products and the retention of tensile elongation are both in good agreement with the calibration curve, and the region A has good mechanical properties of the target member 30 before and after the inflection point IP. It was found that it can be clearly distinguished from the region B in which the mechanical characteristics are deteriorated.

  In addition, the 10 types of construction products were diagnosed with different UV exposure environments and different types of UV absorbers, but all well matched the calibration curve. Therefore, in the present Example, it turned out that the fluctuation factors, such as ultraviolet exposure environment and the kind of ultraviolet absorber, do not affect a diagnostic result.

In the present embodiment, the starting point of the deterioration region indicating that the resin molded product 20 is deteriorated is set on the safer side than the inflection point IP.
In FIG. 6, the safe side means a state in which the tensile elongation is close to the initial state, and corresponds to a region A in the figure.
That is, in this example, when the maximum transmittance of ultraviolet rays obtained from the surface layer 10 to be diagnosed exceeds a predetermined value set to 35% or less, the resin molded product 20 protected by this is protected. Is diagnosed as being in a degraded state.

More specifically, the maximum transmittance of the surface layer 10 obtained with the measurement timing provided every predetermined period (for example, several months to several years) crosses the inflection point IP at the next measurement timing. It is good to determine the time when it is predicted as the start point (point C in the figure) of the degradation region of the resin molded product 20.
And the area | region where the maximum transmittance | permeability of the ultraviolet-ray in the surface layer 10 becomes larger than a starting point can be diagnosed as the lifetime area | region where the resin molded product 20 deteriorated.

On the other hand, the area from the start of UV exposure to the start point (point C) of the deteriorated area can be defined as a safe area or a warning area.
In the case of the present embodiment, the time during which the maximum transmittance of ultraviolet rays in the surface layer 10 is zero can be determined as the safety region of the resin molded product 20. Then, a region belonging to the region A from when the maximum transmittance of ultraviolet light turns positive until the start point (point C) of the deteriorated region can be determined as a warning region of the resin molded product 20.

  According to the present embodiment, by using the characteristic diagram (calibration curve) shown in FIG. 6, it can be determined at a glance whether the constructed target member 30 belongs to the safety area, the warning area, or the life area. The degree of deterioration can be grasped.

In addition, in the said Example, when the initial concentration of the ultraviolet absorber which a resin composition (surface protective layer 14) contains is increased / decreased, ultraviolet rays permeate | transmit the surface protective layer 14 and the 2nd test piece 22 is exposed to ultraviolet rays. Although the number of years until the time fluctuates, the mode of change over time in the mechanical characteristics after the start of exposure of the second test piece 22 to the ultraviolet rays does not change. Therefore, when the initial concentration of the ultraviolet absorber contained in the resin composition is sufficiently high (for example, it has a period in which the maximum transmittance of ultraviolet rays is zero), the calibration curve shown in FIG. The shape of is unchanged.
For this reason, even when the initial concentration of the ultraviolet absorber contained in the surface layer 10 to be diagnosed is different from the initial concentration of the ultraviolet absorbing ability contained in the surface protective layer 14 as the evaluation sample, the surface layer 10 at the time of measurement is different. The degree of deterioration can be diagnosed by estimating the mechanical characteristics of the resin molded product 20 on the basis of the ultraviolet absorption ability and the calibration curve data shown in FIG.

FIG. 7 shows the results obtained by performing an outdoor exposure test on the laminated test piece 32 described above, and the horizontal axis indicates the concentration (wt%) of the ultraviolet absorber contained in the surface protective layer 14 or the surface layer 10. It is the graph which calculated | required the calibration curve similarly to. Moreover, the measurement result regarding 10 types of object members 30 which are the installation goods installed outdoors is plotted in this figure.
A benzotriazole-based ultraviolet absorber was mixed in the surface protective layer 14 of the laminated test piece 32 at an initial concentration of 1.5 wt%.

As shown in FIG. 7, it was found that the inflection point IP also exists in the calibration curve indicating the relationship between the concentration of the ultraviolet absorber and the mechanical characteristics of the target member 30. In this embodiment, the inflection point IP is about 0.25 wt%.
Similarly to FIG. 6, before and after the inflection point IP, it is possible to clearly distinguish between a region A in which the target member 30 to be diagnosed has good mechanical properties and a region B in which the mechanical properties have deteriorated. I understand.

  As described above, even when the concentration of the ultraviolet absorber of the surface layer 10 at the time of diagnosis is used as the ultraviolet shielding ability of the surface layer 10 related to the diagnosis target, the deterioration diagnosis of the target member 30 is performed using the calibration curve obtained from the evaluation sample. It is understood that is possible.

Further, even when the type of the ultraviolet absorber contained in the resin composition (surface protective layer 14) is changed, the tendency of the calibration curve is not changed as shown in FIG. 5, and the surface protective layer 14 corresponding to the inflection point IP is not changed. The numerical value of the ultraviolet ray transmitting ability (maximum transmittance) does not vary greatly. Therefore, regardless of the difference between the ultraviolet absorbers contained in the surface protective layer 14 and the surface layer 10, the resin molded product 20 to be diagnosed is an inflection point using the calibration curves shown in FIGS. It is possible to diagnose whether or not the deterioration is more than IP.
The same applies to the difference between the resin material constituting the surface protective layer 14 and the first resin material constituting the surface layer 10, and even when these are different from each other, the calibration curves shown in FIGS. Thus, the degree of deterioration of the mechanical properties of the resin molded product 20 to be diagnosed can be diagnosed.

The effects of the diagnostic method for the resin molded product 20 according to the embodiment and the example (hereinafter referred to as the present embodiment) will be described.
In the method for diagnosing a resin molded product according to the present embodiment, the mechanical characteristics of the resin molded product 20 are estimated from calibration curve data acquired from the evaluation sample and the ultraviolet transmittance of the surface layer 10. Thereby, even if the elapsed years since the resin molded product 20 to be diagnosed installed outdoors is unknown, the degree of deterioration is diagnosed.

  Moreover, in the diagnostic method of this embodiment, since the resin molded product 20 is protected by the surface layer 10, the influence of pollution by external environments, such as a wind and rain, earth and sand, is excluded. As a result, the deterioration of the resin molded product 20 is dominated by the factor that penetrates the surface layer 10, that is, the influence of crosslinking breakage due to exposure to ultraviolet rays. Therefore, as in the present embodiment, it is possible to estimate the mechanical characteristics of the resin molded product 20 based on the ultraviolet ray transmitting ability of the surface layer 10 that protects the resin molded product 20.

In the present embodiment, the degree of deterioration of the mechanical properties of the resin molded product 20 at that time is diagnosed by measuring the ultraviolet ray transmitting ability of the surface layer 10. Further, according to the present embodiment for measuring the ultraviolet light transmitting ability of the surface layer 10 at the time of diagnosis, the resin molded product 20 and the surface layer 10 are exposed to the ultraviolet light, that is, whether the installation location is sunny or shaded. The degree of deterioration of the mechanical properties of the molded product 20 can be estimated. As a result, when the mechanical properties of the resin molded product 20 installed in the shade where the progress of deterioration due to ultraviolet light exposure is slow and the resin molded product 20 installed in the sun where the progress of degradation is fast are deteriorated to the same extent, respectively. The resin molded product 20 is diagnosed as having deteriorated.
Therefore, according to the diagnosis method of the present embodiment, unlike the method of uniformly diagnosing deterioration based on the number of years since installation, the deterioration diagnosis according to the ultraviolet exposure environment of the resin molded product 20 is possible. There is no possibility that the undegraded resin molded product 20 will be repaired or replaced, and the environmental load can be reduced.

Further, in the diagnostic method of the present embodiment, the ultraviolet ray transmission ability regarding the resin composition and the mechanical characteristics relating to the second test piece 22 that are both exposed to ultraviolet rays in the acquisition step of acquiring the calibration curve data are obtained for each ultraviolet exposure time. Calibration curve data is acquired in association with. By using such calibration curve data, the first resin material constituting the surface layer 10 and the layer thickness of the surface layer 10, the type and initial content of the ultraviolet absorber contained therein, the surface layer 10 and the resin molded product The deterioration diagnosis of the resin molded product 20 becomes possible regardless of various factors such as the ultraviolet exposure environment (ultraviolet irradiation intensity). This is because the ultraviolet shielding ability of the resin composition constituting the first test piece 12 and the mechanical properties of the second test piece 22 are associated with each other based on the ultraviolet exposure time. This is because the calibration curve (characteristic diagram) drawn based on the calibration curve data has the same shape.
Therefore, the UV transmittance measured from the surface layer 10 regardless of the difference in the components and dimensions of the surface layer portion between the evaluation sample and the diagnosis target, and the difference between the UV exposure test environment of the evaluation sample and the outdoor exposure environment of the diagnosis target. Based on the calibration curve data, according to the present embodiment, the degree of deterioration of the resin molded product 20 is diagnosed.

In the diagnosis method of the present embodiment, the starting point of the degradation region is set on the safe side with respect to the inflection point IP of the calibration curve. Thereby, the fall of the mechanical characteristic by deterioration of the resin molded product 20 can be avoided safely.
Further, in the conventional diagnostic method based on the appearance inspection including yellowing and gloss, it is expected that the mechanical properties of the resin molded product have already deteriorated to a considerable extent when yellowing or gloss is observed ( However, according to the present embodiment, it is possible to freely set the start point of the deteriorated region, which can be set on the safe side with respect to the inflection point IP of the mechanical characteristics.

  In the diagnostic method of the present embodiment, the surface layer 10 (first resin material) and the first test piece 12 (resin composition) do not substantially contain an inorganic filler having an ultraviolet shielding ability. As a result, the surface layer 10 and the first test piece 12 have the ultraviolet transmittance remarkably changed according to the volatilization of the ultraviolet absorbent over time, and the deterioration degree of the resin molded product 20 is accurately determined by the diagnostic method of the present embodiment. It can be measured well.

  In the diagnostic method of the present embodiment, polycarbonate is used as the second resin material. Polycarbonate is excellent in impact resistance and transparency, and is widely used as a structural member that requires daylighting, such as skylights and carports, but yellowing over time and deterioration of mechanical properties due to ultraviolet irradiation become a significant problem. This method is a material that can be suitably used.

  The present invention is not limited to the above-described embodiment, and includes various modifications and improvements as long as the object of the present invention is achieved.

For example, in the said embodiment, you may form the 1st resin material which comprises the surface layer 10, and the resin composition which comprises the 1st test piece 12 with a different resin material.
Further, the ultraviolet absorber contained in the first resin material and the ultraviolet absorber contained in the resin composition may be different materials.
Thus, even when the resin material and the ultraviolet absorber are different between the surface layer 10 and the first test piece 12, according to the present embodiment, the mechanical characteristics of the resin molded product 20 are estimated and the degree of deterioration is diagnosed. can do. That is, it is possible to diagnose deterioration of a wide variety of resin molded products 20 based on a small number of calibration curve data.

Moreover, in the said embodiment, although the position is set from a viewpoint of providing with respect to the inflection point IP of a calibration curve regarding the starting point of the degradation area | region of the resin molded product 20, this is the present invention Not limited to.
For example, the last measurement time point at which the resin molded product 20 satisfies the nominal strain defined in JIS K6735 may be determined as the start point of the degradation region. That is, the index value (maximum transmittance) of the first test piece 12 corresponding to the case where the nominal strain at the time of tensile failure of the second test piece 22 matches the lower limit value of the predetermined value is calculated in advance from the calibration curve. Then, the case where the maximum transmittance in the surface layer 10 matches this may be diagnosed as the starting point of the deteriorated region of the resin molded product 20.

  Further, the impact resistance of the resin molded article 20 is generally lowered after the tensile elongation rate and the tensile strength are lowered. Therefore, in the case of diagnosing the deterioration degree of the resin molded product 20 based on the calibration curve obtained by adopting the tensile elongation rate and the tensile strength as the mechanical characteristics of the resin molded product 20, If the starting point is within a predetermined width from the inflection point IP of the calibration curve, it can be set on the dangerous side. Specifically, the deterioration of the resin molded product 20 occurs when the ultraviolet ray transmitting ability of the surface layer 10 obtained by providing a measurement time point every predetermined period (for example, one year) crosses the inflection point IP. It may be determined as the start point of the region.

The initial concentration of the ultraviolet absorber contained in the surface layer 10 is sufficiently high so that the ultraviolet transmittance in the surface layer 10 becomes substantially zero at the start of the outdoor installation of the target member 30. It is preferable to secure a long period until the start point of the deteriorated region. However, regarding the diagnosis method of the present embodiment, the ultraviolet transmittance of the surface layer 10 may exceed zero when the outdoor installation of the target member 30 is started. In such a case, the deterioration diagnosis result of the resin molded product 20 is shifted to the safe side.
Therefore, the deterioration diagnosis of the resin molded product 20 is performed using the calibration curve calculated based on the first test piece 12 in which the initial concentration of the ultraviolet absorber is sufficiently high (for example, the maximum ultraviolet transmittance in the initial state is zero). As long as this is performed, the degree of deterioration of the resin molded product 20 can be diagnosed on the safe side regardless of the initial concentration of the ultraviolet absorber in the surface layer 10.

  In the present embodiment, the target member 30 in which the surface layer 10 is provided only on one side of the resin molded product 20 made of the second resin material is exemplified, but the diagnosis method of the present invention is not limited to this. When diagnosing deterioration due to ultraviolet exposure for the target member 30 provided with the surface layer 10 on both surfaces of the resin molded product 20, it is diagnosed that the surface layer 10 on either side has reached the deterioration region or the warning region. It may be determined that the target member 30 has deteriorated or has started to deteriorate. This is because the mechanical properties of the entire resin molded product 20 are remarkably deteriorated by curing starting on one side of both surfaces of the resin molded product 20.

It is a schematic diagram which shows the object member used for the diagnostic method concerning embodiment of this invention. (A)-(c) is a schematic diagram which shows the test piece which calculates calibration curve data. It is a graph with the elapsed time from the start of UV exposure as the horizontal axis and the residual concentration (retention rate) when the initial concentration of the UV absorber is 100% as the vertical axis. It is a graph which shows the secular change of the elongation of the laminated test piece which coat | covered the 2nd test piece with the surface protective layer which each contains three types of ultraviolet absorbers. It is a graph of a calibration curve in which the horizontal axis is the ultraviolet transmittance of the surface protective layer, and the vertical axis is the tensile elongation retention rate of the laminated specimen. It is the graph which plotted the calibration curve obtained by performing an outdoor exposure test about a lamination test piece, and the measurement result about ten kinds of object members which are construction goods installed outdoors. It is the graph which calculated | required the analytical curve similarly to FIG. 6 by making a horizontal axis into the density | concentration of the ultraviolet absorber contained in a surface protective layer or a surface layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Surface layer 12 1st test piece 14 Surface protective layer 20 Resin molding 22 Second test piece 30 Target member 32 Lamination test piece IP Inflection point

Claims (8)

A method of diagnosing the degree of deterioration of a resin molded product by estimating the mechanical properties of a resin molded product made of a second resin material protected by a surface layer made of a first resin material containing an ultraviolet absorber,
A test piece made of the second resin material, which is made of the same or different kind of resin material as the first resin material and protected by a resin composition containing the same or different kind of ultraviolet absorbent as the ultraviolet absorbent, is used as an evaluation sample. An acquisition step of acquiring calibration curve data indicating a relationship between the ultraviolet transmittance of the resin composition and the mechanical properties of the test piece;
A measuring step for determining the ultraviolet light transmitting ability of the surface layer;
From the measured ultraviolet transmittance of the surface layer and the calibration curve data, a diagnostic step of estimating the mechanical properties of the resin molded product,
Method for diagnosing resin molded product containing   In the obtaining step, the calibration curve data is obtained by associating the ultraviolet ray transmitting ability relating to the resin composition and the mechanical properties relating to the test piece, which are both exposed to ultraviolet rays, for each ultraviolet ray exposure time. The method for diagnosing a resin molded product according to claim 1.   3. The resin molded product according to claim 1, wherein, in the diagnosis step, the resin molded product is diagnosed as being in a deteriorated state when the ultraviolet transmittance of the surface layer belongs to a preset deterioration region. Diagnosis method. A calibration curve drawn on the basis of the calibration curve data and showing the relationship between the ultraviolet transmittance of the resin composition and the mechanical properties of the test piece has an inflection point,
The method for diagnosing a resin molded product according to claim 3, wherein a start point of the deterioration region is set on a safer side than the inflection point.   The method for diagnosing a resin molded product according to any one of claims 1 to 4, wherein the first resin material and the resin composition do not substantially contain an inorganic filler having an ultraviolet shielding ability.   The method for diagnosing a resin molded product according to any one of claims 1 to 4, wherein the first resin material and the resin composition are made of different resin materials.   The diagnostic method for a resin molded product according to any one of claims 1 to 6, wherein the ultraviolet absorber contained in the first resin material and the ultraviolet absorber contained in the resin composition are different materials.   The diagnostic method for a resin molded product according to any one of claims 1 to 7, wherein the second resin material is polycarbonate.

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