Determination apparatus

Abstract

To provide a powder coating formed from a recycled material as a raw material and exhibiting stable quality.SOLUTION: A powder coating containing recycled PET has an IV value of 0.6 or more and has a heat generation amount upon temperature rise of 1 mJ / mg or less. A determination apparatus 1 measures an IV value and a heat generation amount upon temperature rise of a recycled PET pellet or a recycled PET powder coating and determines as acceptable a recycled PET pellet or a recycled PET powder coating having an IV value of 0.6 or more and a heat generation amount upon temperature rise of 1 mJ / mg or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a powder paint and a determination device. [Background technology]

[0002] Powder coating is sometimes applied to metal equipment to protect it from corrosion caused by salt damage, etc. One of the raw materials used in powder coating is petroleum-derived polyethylene terephthalate (PET) resin.

[0003] In recent years, due to growing global environmental concerns and unstable supplies of crude oil due to geopolitical factors, there has been a demand for the development of products made not only from petroleum-derived PET, but also from recycled PET. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-002987 [Non-patent literature]

[0005] [Non-Patent Document 1] "Anti-rust paint SAPOE5000 (thermoplastic polyester resin powder paint)," NTT-AT Creative Corporation, Internet <URL: https: / / www.ntt-atcr.co.jp / item / originalproducts / item29.html?_sm_nck=1> Summary of the Invention [Problem to be solved by the invention]

[0006] Compared to petroleum-derived PET, recycled PET has advantages in terms of "environmental friendliness" and "eliminating the instability of crude oil supplies." When petroleum-derived PET is replaced with recycled PET to produce powder coatings, there are issues with unstable quality, such as poor coating film formation in each production lot and poor performance in durability tests. A method is needed to produce powder coatings with stable quality using recycled PET as a raw material.

[0007] The present disclosure has been made in view of the above, and aims to provide a powder coating material that is made from recycled materials and has stable quality. [Means for solving the problem]

[0008] The powder coating material according to one embodiment of the present disclosure is a powder coating material containing recycled polyethylene terephthalate, has an intrinsic viscosity of 0.6 or more, and does not exhibit an exothermic peak upon heating.

[0009] An evaluation device according to one embodiment of the present disclosure is a device for evaluating the quality of recycled polyethylene terephthalate or powder paint containing recycled polyethylene terephthalate, which is used as a raw material for powder paint, and obtains the intrinsic viscosity of the recycled polyethylene terephthalate or the powder paint, obtains the heat generation amount of the recycled polyethylene terephthalate or the powder paint when the temperature is increased, and evaluates the recycled polyethylene terephthalate or the powder paint as acceptable if the intrinsic viscosity is 0.6 or higher and no heat generation peak is detected when the temperature is increased. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a powder coating material that is made from recycled materials and has stable quality. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a functional block diagram showing an example of the configuration of a determination device that determines the acceptability of raw materials for powder coatings and powder coatings. [Figure 2]FIG. 2 is a flowchart showing an example of the flow of processing by the determination device. [Figure 3] FIG. 3 shows an example of the results of DSC analysis of PET pellets. [Figure 4] FIG. 4 shows an example of the results of DSC analysis of a powder coating material. [Figure 5] Figure 5 is an example of a microscope image of powder paint. [Figure 6] Figure 6 is an example of a microscope image of powder paint. [Figure 7] Figure 7 is an example of a microscope image of powder paint. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0013] Figure 1 is a functional block diagram showing an example of the configuration of a determination device 1 that determines the pass / fail of powder coating raw materials and powder coating materials. When recycled PET pellets or recycled PET powder coating materials, which are used as raw materials for powder coating, are fed into the determination device 1, the determination device 1 measures the intrinsic viscosity (IV) value and the amount of heat generated when heated, and determines the pass / fail of the recycled PET pellets or recycled PET powder coating based on the IV value and the amount of heat generated. The determination device 1 can be used to screen recycled PET pellets used as raw materials for powder coating or to control the quality of recycled PET powder coating materials.

[0014] 1 includes an indication determination unit 11, an IV value measurement unit 12, a DSC measurement unit 13, and a calculation and recording unit 14. Each unit included in the determination device 1 may be configured by at least one computer including an arithmetic processing unit, a storage device, etc., and the processing of each unit may be executed by a program. This program is stored in a storage device included in the determination device 1, and can also be recorded on a computer-readable non-transitory recording medium such as a magnetic disk, an optical disk, or a semiconductor memory, or provided via a network.

[0015] When a sample (recycled PET pellets or recycled PET powder paint) is fed into the judgment device 1, the instruction judgment unit 11 controls the IV value measurement unit 12 and the DSC measurement unit 13 to perform a series of measurements, judges whether the sample passes or fails based on the measurement results, and records the measurement results and pass or fail in the calculation recording unit 14.

[0016] The IV value measurement unit 12 measures the IV value of the sample using a viscometer. The IV value of PET is an index that represents the degree of polymerization of the PET resin raw material. For example, PET with an IV value of approximately 0.8 is used for PET bottles. The IV value of recycled PET decreases due to the heat applied during the recycling process.

[0017] The DSC measurement unit 13 uses a differential scanning calorimeter (DSC) to measure the amount of heat generated when the temperature of a sample is increased. A DSC is a device that detects the thermal behavior of a substance when it is heated or cooled, and can observe phase transition phenomena such as crystallization of the sample.

[0018] The calculation and recording unit 14 records the measurement results and pass / fail for each sample.

[0019] The IV value measurement unit 12 may acquire the IV value of a sample measured by another device, and the DSC measurement unit 13 may acquire the calorific value of a sample measured by another device during heating. That is, the determination device 1 may input the IV value of a sample and the calorific value during heating, and determine whether the sample is pass or fail based on the input measurement results.

[0020] Next, an example of the flow of processing by the determination device will be described with reference to the flowchart of FIG.

[0021] In step S11, the determination device 1 measures the IV value of the sample.

[0022] In step S12, the determination device 1 determines whether the sample is unacceptable based on the IV value. Specifically, the determination device 1 determines that a sample with an IV value of less than 0.6 is unacceptable. The grounds for the IV value condition and the heat generation amount condition during temperature rise will be described later.

[0023] In step S13, the determination device 1 performs DSC measurement on the sample. In the DSC measurement, it is advisable to raise the temperature from room temperature to about 300° C. (the temperature at the time of powder coating) and observe the heat generation and endothermic behavior of the sample.

[0024] In step S14, the determination device 1 determines that a sample in which an exothermic peak is detected during heating is unacceptable. Specifically, the determination device 1 determines that a sample in which the amount of heat generated during heating is 1 mJ / mg or less is acceptable, and determines that a sample in which the amount of heat generated during heating is greater than 1 mJ / mg is unacceptable.

[0025] The order of steps S11 and S12 and steps S13 and S14 does not matter. The IV value may be measured after the DSC measurement, or the DSC measurement and the IV value measurement may be performed in parallel.

[0026] The evaluation device 1 evaluates a sample that meets the standards for both the IV value and the heat generation amount during heating as passing. If the sample that has been evaluated as passing is made of recycled PET pellets, the powder paint is manufactured using recycled PET pellets from the same production lot as the sample. If the sample that has been evaluated as passing is recycled PET powder paint, the quality of the recycled PET powder paint for that sample is passing.

[0027] Furthermore, since recycled PET powder paint is made by mixing additives such as antioxidants and UV absorbers with raw materials made from recycled PET pellets, it is not possible to measure the characteristics of the PET resin alone, it is difficult to dissolve it in a solvent when measuring the IV value, and the IV value does not change before and after the powder paint is applied. Therefore, when judging powder paint, it is not necessary to carry out the processing of steps S11 and S12, provided that a raw material with an IV value of 0.6 or higher is used.

[0028] Next, the conditions for the IV value and the amount of heat generated during temperature rise will be described.

[0029] In order to clarify the physical property parameters of recycled PET that distinguish between acceptable and unacceptable powder coatings, the inventors prepared powder coatings Samples 1 to 5 and examined their film-forming ability and durability. Samples 1 to 5 are powder coatings made from recycled PET pellets with different crystallization states and IV value grades. The manufacturing and testing methods for the test specimens are explained below.

[0030] Powder coatings for Samples 1 to 5 were prepared and each was applied to a 150 x 70 x 3.2 mm steel plate in the laboratory using the fluidized bed method. Specifically, the steel plate to be coated was heated to 300°C or higher, immersed in a fluidized bed tank containing the powder coating for several seconds, and then cooled with water for at least 1 minute to coat the steel plate.

[0031] In Samples 1, 2, and 5, the coating did not adhere well to the steel sheet, and a clean coating could not be formed.

[0032] Samples 3 and 4 were subjected to durability tests, including an alkali resistance test, a salt spray test, and a weather resistance test.

[0033] For the alkali resistance test, a commercially available 10% NaOH aqueous solution was placed in a plastic case, and the test specimen was hung in it, with approximately the bottom three-quarters of the specimen immersed in the solution. The test equipment was placed in an indoor environment (with air conditioning on when people were present). After seven days, the pass criteria were no change in appearance and a mass change rate within ±3%.

[0034] In the salt spray test, the test specimens were subjected to repeated cycles under the conditions shown in Table 1. The pass criterion was that no rust or corrosion was observed after 2000 hours.

[0035] [Table 1]

[0036] In the weather resistance test, a weather resistance tester SX-75 (manufactured by Suga Test Instruments Co., Ltd.) was used, and the test specimens were repeatedly subjected to the conditions shown in Table 2. Light with a wavelength of 300 nm to 400 nm was used, and the irradiance was set to 60 W / m 2 Distilled water was used for spraying. The pass criterion was that no rust or corrosion was observed after 2000 hours.

[0037] [Table 2]

[0038] Sample 3 failed all durability tests, but Sample 4 passed all durability tests. From the test results, the inventors discovered that the heat generation rate is key to coating film formation, and the IV value is key to durability. Table 3 shows the blending ratio of PET and recycled PET, the heat generation rate at temperature rise, the IV value, and the test results for Samples 1 to 5. ○ indicates a pass, and × indicates a fail.

[0039] [Table 3]

[0040] Table 3 also shows the test results for an example in which recycled PET pellets were screened using the aforementioned evaluation method and powder coatings were produced from recycled PET pellets that were judged to pass. Samples 2 to 5 were powder coatings produced by mixing petroleum-derived PET and recycled PET, while the example was produced without mixing petroleum-derived PET and instead using recycled PET pellets with an IV value of 0.6 and a heat release rate of less than 1 mJ / mg upon heating. Sample 1 also did not mix petroleum-derived PET, but the recycled PET pellets were not screened.

[0041] The test pieces of the examples were also produced by applying the powder coating of the examples to steel plates using the fluidized bed method, similar to samples 1 to 5. The powder coating of the examples was able to form a coating film on the steel plates. The test pieces of the examples were also subjected to alkali resistance tests, salt spray tests, and weather resistance tests, similar to samples 3 and 4. The test pieces of the examples met the pass criteria in all tests.

[0042] The powder coating of sample 4 contains recycled PET, has an IV value of 0.6 or more, and generates less than 1 mJ / mg of heat upon heating, so it can be said to be a powder coating of the present invention.

[0043] Next, an example of the results of DSC analysis will be described.

[0044] PET pellets (samples A, B, and C), which are used as raw materials for powder coatings, were heated from 30°C to 300°C at a rate of 10°C / min (temperature condition A) and then cooled from 300°C to 30°C (temperature condition B) using a DSC7000X (Hitachi) to measure the heat transfer to and from the samples. Sample A is a petroleum-derived PET pellet. Samples B and C are recycled PET pellets. Table 4 shows the DSC measurement results, and Figure 3 shows a graph of the DSC analysis results.

[0045] [Table 4]

[0046] As can be seen from the graph in Figure 3, no exothermic peak due to recrystallization was detected in samples A, B, and C. The crystallization temperature of PET is approximately 130°C. The film-forming ability of the powder coatings produced from samples A, B, and C was good. The DSC measurement results for the pellets showed that it is possible to screen powder coatings for their ability to form films.

[0047] As with the PET pellets, the powder coatings (samples D, E, F, and G) were also measured using a Hitachi DSC7000X. The samples were heated from 30°C to 300°C at a rate of 10°C / min (temperature condition A) and then cooled from 300°C to 30°C (temperature condition B), and the heat transfer to and from the samples was measured. Sample D is a powder coating made from petroleum-derived PET pellets. Samples E, F, and G are powder coatings made from recycled PET pellets. Table 5 shows the DSC measurement results, and Figure 4 shows a graph of the DSC analysis results.

[0048] [Table 5]

[0049] As can be seen from the graph in Figure 4, no exothermic peak due to recrystallization was detected in samples D, E, and F, but an exothermic peak due to recrystallization (at the location indicated by the symbol 100) was detected in sample G. Samples D, E, and F had good film-forming ability, but sample G was unable to form a film. It is presumed that sample G experienced a phase transition from amorphous to recrystallized at around 130°C, which prevented the coating from adhering to the steel plate and prevented film formation. The DSC measurement results for powder coatings demonstrated that quality control of powder coating film formation is possible.

[0050] Microscope images of powder paints are shown in Figures 5 to 7. Figures 5 and 6 are microscope images of recycled PET powder paints, and Figure 7 is a microscope image of petroleum-derived PET powder paints. In both PET powder paints, the particle shapes were irregular, and particle sizes varied from 10 to 200 μm.

[0051] As described above, the powder coating material of this embodiment is a powder coating material containing recycled PET, has an IV value of 0.6 or more, and generates heat at temperature of 1 mJ / mg or less, making it possible to provide a powder coating material made from recycled materials and having stable quality.

[0052] The evaluation method of this embodiment measures the IV value and calorific value of recycled PET pellets when heated, and evaluates recycled PET pellets that have an IV value of 0.6 or more and a calorific value of 1 mJ / mg or less when heated as acceptable. This allows for appropriate screening of raw materials used in the production of powder coatings.

[0053] The evaluation method of this embodiment measures the IV value and calorific value of a powder coating material when it is heated, and evaluates a powder coating material that has an IV value of 0.6 or more and a calorific value of 1 mJ / mg or less when it is heated as passing the test. This allows quality control of the powder coating material. [Explanation of symbols]

[0054] 1 Judgment device 11 Instruction judgment section 12 IV value measurement unit 13 DSC measurement section 14 Calculation Recording Section

Claims

1. A powder paint containing recycled polyethylene terephthalate, The intrinsic viscosity is 0.6 or more, and no exothermic peak is detected during heating. Powder paint.

2. The powder coating material according to claim 1, The heat generation amount during temperature rise is 1 mJ / mg or less. Powder paint.

3. A device for determining the quality of recycled polyethylene terephthalate or powder paint containing recycled polyethylene terephthalate, which is used as a raw material for powder paint, Obtaining the intrinsic viscosity of the recycled polyethylene terephthalate or the powder paint; The amount of heat generated when the recycled polyethylene terephthalate or the powder paint is heated is obtained, The recycled polyethylene terephthalate or the powder coating having an intrinsic viscosity of 0.6 or more and no exothermic peak detected during the temperature rise is judged to be acceptable. Judgment device.

4. The determination device according to claim 3, The recycled polyethylene terephthalate or the powder paint having a calorific value of 1 mJ / mg or less upon temperature rise is judged as passing. Judgment device.

Images