Weatherproofing agent determination method

Abstract

To provide a weatherproofing agent determination method capable of determining whether or not a weatherproofing agent is contained in a resin material even when an addition amount of the weatherproofing agent is small and it is not possible to confirm a characteristic peak derived from the weatherproofing agent.SOLUTION: A calculation processing unit 10 smoothes a reflection or absorption spectrum obtained by reflected light 4 received from a resin 2 irradiated with infrared light 3 in a wavelength band of 1.4 μm or more and 2.3 μm or less, calculates a spectral intensity difference between the smoothed spectrum and the reflection or absorption spectrum, calculates an integrated value of an absolute value of the spectral intensity difference, and when the integrated value is evaluated to be equal to or larger than a preset threshold value, determines that the resin is a resin containing a weatherproof imparting agent.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a weather resister determining method for determining whether or not a weather resister is contained in a resin to be determined. [Background technology]

[0002] Economic activities involving mass consumption and mass waste have given rise to environmental problems on a global scale, such as global warming and resource depletion.

[0003] In light of this situation, and with the aim of building a resource-circulating society, the Home Appliance Recycling Law came into force in Japan in April 2001. This law requires the recycling of used home appliances (air conditioners, televisions, refrigerators, freezers, washing machines, clothes dryers, etc.).

[0004] As a result, used home appliances are crushed into small pieces at home appliance recycling plants, and then sorted and collected by material type using magnetism, wind power, vibration, etc., and recycled as recyclable materials. Polypropylene (hereinafter referred to as PP), polystyrene (hereinafter referred to as PS), and acrylonitrile butadiene styrene (hereinafter referred to as ABS) are commonly used resin materials in home appliances, and they are sorted and collected by resin type using a sorting device that uses the absorption properties of the resin in the near-infrared region due to its molecular structure.

[0005] In addition, some resins used in home appliances have weatherproofing agents added to them to improve their functionality. When recycling these functional resins, screening them to see whether they contain the functionality-imparting agent or not is effective in maintaining their physical properties during recycling. Therefore, it has become necessary to determine whether the weatherproofing agent is contained in the resin of the recycled material.

[0006] Conventional methods for determining whether a resin is recycled include infrared spectroscopy using infrared light (see Patent Document 1). This method detects the absorption spectrum of chemical bonds derived from the material composition and determines the composition of the resin by analyzing the peak area or the slope of the reflectance profile.

[0007] FIG. 7 is a schematic diagram of a conventional determination device described in Patent Document 1. In FIG.

[0008] FIG. 8 shows the absorption spectra of PS and ABS described in Patent Document 1.

[0009] In FIG. 7, 30 is a reflectance measuring section, 31 is a resin identifying section, 32 is resin flakes, 33 is a flake supply section, 34 is a flake transport section, 34a is a discharge port, 35 is a flake discriminating section, 36 is a resin recovery section, and 36a and 36b are flake recovery containers.

[0010] Next, the processing procedure according to the above configuration will be described with reference to FIG.

[0011] The flowchart in FIG. 9 shows the process steps executed by the resin identification unit 31.

[0012] In step S21, infrared light is irradiated onto resin flakes 32 made of PS resin or ABS resin, and the reflected light is received, and the reflectance profile is obtained using the reflectance measuring unit 30.

[0013] Next, in step S22, the wave number 2000 cm is determined from the profile. -1 The area in a predetermined wavenumber range in which the absorption of the PS resin is small is calculated as index A. In this example, the area in the wavenumber range of 1967 to 2229 cm -1 The reflectance area in this range is calculated and is designated as index A.

[0014] Next, in step S23, the calculated index A is compared with a preset threshold value, and if index A is greater than the threshold value, it is determined that the sample is not black and the process proceeds to step S24.2, whereas if index A is equal to or less than the threshold value, it is determined that the sample is black and the process proceeds to step S24.1.

[0015] Next, in step S24.1, when the calculated index A is equal to or smaller than a threshold, index B is calculated. For example, the wave number is 2245 cm -1 The slope of the reflectance profile before and after is calculated as index B. At this time, index B for PS (black) will be very small or will have a negative value, while index B for ABS (black) will have a relatively large positive value, so by setting a threshold value for index B, these two types of resin can be clearly distinguished by index B.

[0016] In step S24.2, when the calculated index A is greater than the threshold value, the index C is calculated. -1 The slope of the reflectance plot before and after is calculated as index C. Index C is calculated when the sample is judged not to be black. -1 Looking at the slope of the reflectance profile with the endpoints at , the slope of the PS resin is smaller than that of the ABS resin. Therefore, by setting a threshold value Cth for index C, these two types of resins can be clearly distinguished by index C. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] JP 2015-121506 A Summary of the Invention [Problem to be solved by the invention]

[0018] However, in the discrimination method of Patent Document 1, qualitative and quantitative analysis is performed on the entire resin composition, so when a trace amount of additive is added to the resin composition, the peak of this additive is difficult to appear. An example of an additive that is added in a trace amount to a resin is a weathering agent that imparts weather resistance. In other words, in the conventional discrimination method, the amount of weathering agent added is small compared to the weather resistance imparting material, so the peak intensity derived from the weathering agent is small, making it difficult to discriminate the presence or absence of the weathering agent.

[0019] The present invention is devised to solve the above-mentioned problems of the conventional art, and aims to provide a weather resister discrimination method that can determine whether or not a weather resister is contained in a resin material, even when the amount of weather resister added is small and no characteristic peak derived from the weather resister can be confirmed. [Means for solving the problem]

[0020] The present invention is intended to solve the above-mentioned problems in the conventional art. According to a weathering agent identifying method according to one aspect of the present invention, a calculation processing unit: Among the reflection or absorption spectra obtained by the reflected light received from the resin irradiated with infrared light, a spectrum is smoothed in a wavelength band of 1.4 μm or more and 2.3 μm or less; Calculating a spectral intensity difference between the smoothed spectrum and the reflection or absorption spectrum; Calculating an integrated value of the absolute values ​​of the spectral intensity differences; When the integrated value is evaluated to be equal to or greater than a preset threshold value, the resin is determined to be a resin containing a weather resistance imparting agent. Effect of the Invention

[0021] As described above, according to the weather-resistant agent discrimination method of the above aspect of the present invention, the integrated value of the absolute values ​​of the spectrum intensity differences calculated from the reflection or absorption spectrum of the resin is compared with a threshold value, and depending on whether the integrated value is equal to or greater than the threshold value, a difference in the S / N ratio due to the weather-resistant agent can be detected, and whether the resin contains a weather-resistant agent can be discriminated. As a result, when discriminating whether the resin material contains a weather-resistant agent using the reflection or absorption spectrum of the sorting object, even if the amount of the weather-resistant agent added is small and a specific peak due to the weather-resistant agent cannot be confirmed, weather-resistant agent discrimination that discriminates whether the resin material contains a weather-resistant agent is possible. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic diagram of a weathering agent discrimination device according to a first embodiment of the present invention; [Diagram 2] Graph showing the spectrum of a weathering agent alone to be determined in the first embodiment of the present invention. [Diagram 3] Graph of spectrum used to determine whether or not weather resistance agent is contained in polypropylene to be determined in embodiment 1 of the present invention [Figure 4] 1 is a graph showing a spectrum obtained by smoothing the spectrum of polypropylene containing a weathering agent to be identified in the first embodiment of the present invention. [Diagram 5] A flowchart showing a procedure for determining a weathering agent according to the first embodiment of the present invention. [Figure 6] A flowchart showing the procedure for the weather resistance agent identification device to identify a resin in the first embodiment of the present invention. [Figure 7] Schematic diagram of a determination device described in Patent Document 1 [Figure 8] FIG. 1 shows the absorption spectra of PS and ABS described in Patent Document 1. [Figure 9] A flowchart showing the processing procedure executed by the resin recognition unit described in Patent Document 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0024] [Embodiment 1] FIG. 1 is a schematic diagram of a weathering agent identifying device 1 capable of implementing a weathering agent identifying method according to the first embodiment.

[0025] In Fig. 1, 2 denotes a resin to be discriminated, 2a denotes a resin to be discriminated that contains a weather-resistant agent, 2b denotes a resin to be discriminated that does not contain a weather-resistant agent, 3 denotes irradiated light, 4 denotes reflected light, 5 denotes a conveyor, 6 denotes an input area, 7 denotes a detection area, 8 denotes an infrared detection unit, 9 denotes a digital data conversion device, 10 denotes a calculation processing device as an example of a calculation processing section, 10a denotes a spectrum calculation section, 10b denotes a calculation section, and 10c denotes a judgment section. The resin 2 is a resin for which it is unknown whether or not it contains a weather-resistant agent. The configuration of a weather-resistant agent discrimination device 1 that detects a weather-resistant agent from the resin 2 will be described with reference to Fig. 1.

[0026] The weathering agent identifying device 1 includes an infrared detection unit 8, a digital data conversion device 9, and an arithmetic processing device 10.

[0027] The infrared detection unit 8 has a function of irradiating the resin 2 with infrared light, which is an example of the irradiated light 3 , and a function of receiving the reflected light 4 of the irradiated light 3 from the resin 2 .

[0028] The digital data conversion device 9 converts the electrical signal output by the infrared detection unit 8 in response to the reflected light 4 into digital data.

[0029] The calculation processing device 10 calculates the reflection or absorption spectrum (hereinafter simply referred to as the “absorption spectrum”) of the resin 2 based on the digital data output from the digital data conversion device 9. 1, a conveyor belt 5 is moved at a constant speed by a driving device such as a motor, and is an example of a transfer section that transfers resin 2 placed on the conveyor belt 5. The resin 2 is transferred by this conveyor belt 5 from an input area 6 to a detection area 7 along the longitudinal direction of the conveyor belt 5.

[0030] Moreover, above the detection area 7 of the conveyor belt 5, an infrared detection unit 8 is disposed.

[0031] The arithmetic processing device 10 includes a spectrum calculation unit 10a, a calculation unit 10b, and a judgment unit 10c. The spectrum calculation unit 10a of the arithmetic processing device 10 analyzes the information output from the digital data conversion device 9 to obtain the absorption spectrum of the resin 2. The calculation unit 10b of the arithmetic processing device 10 detects the presence or absence of a weathering agent by evaluating this absorption spectrum. Furthermore, the judgment unit 10c of the arithmetic processing device 10 judges the resin 2 in which a weathering agent has been detected as a resin 2a containing a weathering agent, and judges the resin 2 in which a weathering agent has not been detected as a resin 2b not containing a weathering agent.

[0032] Here, a method in which the spectrum calculation section 10a of the processor 10 calculates the absorption spectrum from the input digital data will be briefly described.

[0033] The electric signal photoelectrically converted by the infrared detection unit 8 in response to the reflected light 4 depends on the intensity of the received light. Therefore, it is possible to obtain information on the intensity of the reflected light 4 from the resin 2 from the digital data converted by the digital data conversion device 9. The absorption spectrum of the resin 2 can be obtained by the spectrum calculation unit 10a from the obtained intensity of the reflected light 4. The presence or absence of a weather resistance agent is detected by evaluation by the judgment unit 10c from this absorption spectrum, and it is determined whether or not the resin 2 contains a weather resistance agent.

[0034] Next, the results of an experiment conducted based on the method for detecting the presence or absence of a weather resistance agent according to the first embodiment will be described.

[0035] Figure 2 is a graph of the spectrum of the weathering agent alone. The horizontal axis of the graph in Figure 2 represents the wave number band, and the vertical axis represents the reflection intensity. From the results in Figure 2, characteristic peaks derived from the weathering agent were confirmed around 1.45 μm and 1.55 μm.

[0036] Next, it was confirmed whether characteristic peaks derived from the weathering agent were observed in the resin containing the weathering agent.

[0037] Below, an experiment was carried out in the case where the resin was polypropylene.

[0038] FIG. 3 is a graph of the spectrum when the resin is polypropylene.

[0039] In Fig. 3, 20 is the absorption spectrum of polypropylene with a weathering agent added, obtained by the spectrum calculation unit 10a, and 20a is the absorption spectrum of polypropylene alone. Here, the absorbance value on the vertical axis is relatively changed in the absorption spectrum 20a to make it easier to compare with the absorption spectrum 20.

[0040] From the results in FIG. 3, when the resin was polypropylene, no difference in peak intensity at around 1.45 μm and 1.55 μm resulting from the weathering agent could be confirmed.

[0041] This is because the amount of weathering agent added is so small, around 1%, that it cannot be detected with the resolution of existing spectrometers.

[0042] However, the spectrum of polypropylene with weathering agent added, shown in Figure 3, has a different S / N ratio in the band above 1.7 μm when compared to the spectrum of polypropylene alone, while no difference in S / N ratio can be confirmed in the band below 1.7 μm.

[0043] For this reason, the present inventors considered that it would be possible to determine whether or not a weather resistance agent is contained by evaluating the spectrum of the infrared bands onward from 1.7 μm and below 1.7 μm.

[0044] In addition, when the type of resin is known, a similar evaluation as described above can be performed to detect differences in the S / N ratio due to weathering agents, making it possible to determine whether or not weathering agents are contained not only in polypropylene but also in polystyrene or ABS resin.

[0045] Next, a weather resistance agent determining method performed by the calculation unit 10b and the determination unit 10c will be described with reference to the flowchart of FIG.

[0046] The light source in the infrared detection unit 8 is provided with a light source capable of irradiating the resin 2 with light having a wavelength of 1.4 μm or more and 2.3 μm or less.

[0047] The infrared detection unit 8 is also provided with light receiving elements for receiving the reflected waves from the light sources.

[0048] FIG. 4 shows an absorption spectrum 20 of polypropylene with added weathering agent obtained by the spectrum calculation unit 10a, and a smoothed spectrum 21 calculated by the operation unit 10b.

[0049] The flowchart in FIG. 5 shows the processing steps in the calculation unit 10b and the determination unit 10c.

[0050] First, step S1 in FIG. 5 will be described. In step S1, the calculation unit 10b performs smoothing processing on the absorption spectrum 20 calculated by the spectrum calculation unit 10a, and the calculation unit 10b calculates a smooth spectrum 21. One example of the smoothing processing is to add data on both sides of a certain point of the acquired spectrum and take an average to obtain the data. Here, the spectrum to be smoothed is a spectrum in a smoothing processing band in a wavelength band of 1.4 μm or more and 2.3 μm or less. The smoothing processing band may be the entire wavelength band of 1.4 μm or more and 2.3 μm or less, a band for which an integrated value is obtained, or an intermediate band between the entire wavelength band of 1.4 μm or more and 2.3 μm or less and the band for which an integrated value is obtained.

[0051] Next, step S2 in Fig. 5 will be described. In step S2, the calculation unit 10b calculates the absorbance intensity difference between the absorption spectrum 20 and the smoothed spectrum 21. This calculated absorbance intensity difference, i.e., the spectral intensity difference, makes it possible to detect the difference in S / N ratio caused by the weathering agent.

[0052] Next, step S3 in FIG. 5 will be described. In step S3, the absolute value of the absorbance intensity difference calculated in step S2 is integrated by the calculation unit 10b, and the integrated value of the absolute value of the absorbance intensity difference between the absorption spectrum 20 and the smooth spectrum 21 is calculated by the calculation unit 10b, and this is set as the integrated value A. Here, the integrated value is calculated as the absolute value of the absorbance intensity difference, i.e., the spectrum intensity difference, in the integration processing band. The integration processing band is a band in the smoothing processing band (for example, a wavelength band of 1.4 μm or more and 2.3 μm or less) in which a difference in the S / N ratio is likely to occur (for example, a wavelength band of 1.8 μm or more and 1.9 μm or less), and based on the reflection or absorption spectrum of a wavelength band of at least 0.1 μm, the judgment unit 10c can judge whether or not the resin contains a weather resistance imparting agent in the following steps. Here, the integration processing band is further selected and integrated from the smoothing processing band in order to make the judgment easier by extracting a band in which a difference in the S / N ratio is likely to occur.

[0053] Next, step S4 in Fig. 5 will be described. In step S4, the determination unit 10c compares the calculated integrated value A with a preset threshold value, and if the determination unit 10c determines that the integrated value A is equal to or greater than the threshold value, the determination unit 10c can determine that the resin to be determined contains a weather resistance agent. On the other hand, if the determination unit 10c determines that the integrated value A is less than the threshold value, the determination unit 10c can determine that the resin to be determined does not contain a weather resistance agent.

[0054] Here, the threshold value is set by calculating in advance the integrated values ​​A of the resin to which no weather resisting agent is added and the resin to which the weather resisting agent is added by the calculation unit 10b, and comparing the respective integrated values ​​A by the judgment unit 10b. Specifically, since the integrated value A of the resin to which the weather resisting agent is added is greater than the integrated value A of the resin not containing the weather resisting agent, a value near the midpoint between the two integrated values ​​A is set as the threshold value.

[0055] An example of an actual processing method will now be described with reference to the flow chart of FIG.

[0056] The following describes an example of a treatment method for a resin made of polypropylene alone and a resin made of polypropylene with a weathering agent added thereto.

[0057] Step S1 in Fig. 5 will be described below. In step S1, the calculation unit 10b calculates a smoothed spectrum by averaging 10 points of measurement data for the absorption spectrum between 1.8 µm and 1.9 µm as the smoothing processing band.

[0058] Next, a description will be given of step S2 in Fig. 5. In step S2, the calculation unit 10b calculates the intensity difference between the absorption spectrum in the smoothing processing band from 1.8 µm to 1.9 µm and the smoothed spectrum.

[0059] Next, step S3 in Fig. 5 will be described. In step S3, the absolute values ​​of the absorbance intensity differences calculated in step S2 are integrated by the calculation unit 10b, and the integrated value is set as an integrated value A. In this example, the integration processing band is the same as the smoothing processing band. In addition, the integrated value of the polypropylene alone was 3.017, and the integrated value of the resin in which a weathering agent is added to polypropylene was 4.538.

[0060] Next, in step S4, the threshold value of this processing example is set to 3.7, so that the presence or absence of a weather resistant agent can be determined from the value of the integrated value A. That is, the calculated integrated values ​​3.017 and 4.538 are compared with the preset threshold value of 3.7 by the judgment unit 10c. When the integrated value of the resin in which a weather resistant agent is added to polypropylene is 4.538, the judgment unit 10c judges that the integrated value 4.538 is greater than the threshold value 3.7, and the judgment unit 10c judges that the resin to be judged contains a weather resistant agent. On the other hand, when the integrated value of polypropylene alone is 3.017, the judgment unit 10c judges that the integrated value 3.017 is less than the threshold value 3.7, and the judgment unit 10c judges that the resin to be judged does not contain a weather resistant agent.

[0061] Next, the operation of the weather resistance agent identifying apparatus 1 in FIG. 1 will be described with reference to the flowchart in FIG.

[0062] Here, the flow will be described up to the point where it is determined whether or not a weather resistance agent is contained, focusing on one resin 2 among the multiple resins present.

[0063] First, in step S11, the resin 2 is poured into the pouring area 6 on the conveyor belt 5 which is moving at a constant speed.

[0064] Next, in step S12, the infrared detection unit 8 irradiates the resin 2 that has reached the detection area 7 with infrared irradiation light 3 and detects the reflected light 4 from the resin 2.

[0065] Next, in step S13, information on the reflected light 4 detected by the infrared detection unit 8 is output from the infrared detection unit 8 through the digital data conversion device 9 to the calculation processing device 10, and in the calculation processing device 10, the spectrum of the resin 2 is calculated in the spectrum calculation section 10a based on the input information on the reflected light 4.

[0066] Next, in step S14, the calculation unit 10b performs a smoothing process (step S1) of the spectrum calculated by the spectrum calculation unit 10a, calculates the spectral intensity difference (step S2), and calculates the integrated value of the absolute value of the spectral intensity difference (step S3).Then, the judgment unit 10c compares the integrated value with a preset threshold value and evaluates whether the calculated integrated value is equal to or greater than the threshold value, and judges whether or not the resin 2 contains a weather resistance agent.

[0067] As described above, according to the weather resister discrimination method of the first embodiment, the integrated value of the absolute values ​​of the spectral intensity differences calculated from the reflection or absorption spectrum of the resin 2 is compared with a threshold value, and depending on whether the integrated value is equal to or greater than the threshold value, a difference in the S / N ratio due to the weather resister can be detected, and it can be determined whether the resin contains a weather resister. As a result, when determining whether a weather resister is contained in a resin material using the reflection or absorption spectrum of the sorting object, even if the amount of weather resister added is small and a specific peak due to the weather resister cannot be confirmed, it is possible to perform weather resister discrimination to determine whether a weather resister is contained in a resin material.

[0068] In addition, by appropriately combining any of the various embodiments or modifications described above, it is possible to achieve the effects of each of them. In addition, combinations of embodiments, combinations of examples, or combinations of embodiments and examples are possible, and combinations of features of different embodiments or examples are also possible. [Industrial Applicability]

[0069] The weather resistance agent determining method for determining whether or not a resin contains a weather resistance agent according to the above-mentioned aspect of the present invention can quickly determine whether or not a resin contains a weather resistance agent, and therefore can be used in recycling processes, etc., in which items to be sorted are quickly sorted. [Explanation of symbols]

[0070] 1 Weatherproofing agent identification device 2. Resin 2a resin 2b resin 3. Irradiation light 4 Reflected light 5. Conveyor Belt 6 Input area 7 Detection Area 8 Infrared Detection Unit 9. Digital Data Conversion Device 10 Processing unit 10a Spectral calculation section 10b Arithmetic unit 10c Judgment section 20 Absorption Spectrum 20a Absorption spectrum 21 Smooth Spectrum 30 Reflectance measurement section 31 Resin Identification Department 32 Resin flakes 33 Flake Supply Section 34 Flake conveying section 34a Outlet 35 Flake discrimination section 36 Resin Recovery Section 36a Flake collection container 36b Flake collection container

Claims

1. The calculation processing unit: A reflection or absorption spectrum obtained by reflecting light received from a resin irradiated with infrared light is subjected to a smoothing process within a wavelength band of 1.4 μm or more and 2.3 μm or less; Calculating a spectral intensity difference between the smoothed spectrum and the reflection or absorption spectrum; Calculating an integrated value of the absolute values ​​of the spectral intensity differences; When the integrated value is evaluated to be equal to or greater than a preset threshold value, the resin is determined to be a resin containing a weather resistance imparting agent. How to identify weatherproofing agents.

2. The spectrum to be smoothed is a spectrum in a smoothing band within a wavelength band of 1.4 μm or more and 2.3 μm or less, The weathering agent identifying method according to claim 1 , wherein the integrated value is an absolute value of the spectral intensity difference in an integrated processing band.

3. 3. The weather resistance agent determining method according to claim 2, wherein, when determining whether or not the resin is a resin containing a weather resistance agent, the calculation processing unit determines whether or not the resin contains a weather resistance agent based on the reflection or absorption spectrum in the wavelength band of 1.4 μm or more and 2.3 μm or less, which is the smoothing processing band, of a wavelength band of at least 0.1 μm as the integration processing band within the wavelength band of 1.7 μm or more and 2.3 μm or less.

Images