Resin molded product and method of determining deterioration thereof

Abstract

To enable easy determination of deterioration of resin molded products.SOLUTION: A resin molded product 10 is made of a given resin material and is provided with a discoloring portion 20 designed to exhibit color change before appearance of discoloration due to deterioration of the resin molded product 10.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a resin molded product made of a predetermined resin material, such as a component constituting an apparatus, and a method for determining deterioration thereof. [Background technology]

[0002] 2. Description of the Related Art Conventionally, resin molded products (resin parts) made of a predetermined resin material have been used as components in various devices (industrial products) (see, for example, Patent Document 1). Once such resin molded products have completed their useful life in the market and are collected from the market, their degree of deterioration is assessed at recycling plants, etc., and a decision is made as to whether or not they can be reused depending on the degree of deterioration.

[0003] On the other hand, Patent Document 1 discloses a technology for embedding an electronic tag that stores information about a resin molding in the resin molding and coloring the electronic tag so that the embedding position can be identified, with the aim of improving the efficiency of the recycling process of the resin molding. Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, it has not been possible to determine the deterioration of resin molded products without much effort. On the other hand, the technology in Patent Document 1 involves obtaining information about a resin molded product from an electronic tag embedded in the resin molded product and storing the necessary information in the electronic tag, but is not able to adequately determine the deterioration of the resin molded product.

[0005] The present invention has been made to solve the above-mentioned problems, and has an object to provide a resin molded product and a method for determining deterioration of a resin molded product, which makes it possible to easily determine deterioration. [Means for solving the problem]

[0006] The resin molded product in the present invention is a resin molded product made of a predetermined resin material, and is provided with a discoloration portion that changes color before discoloration due to deterioration occurs in the resin molded product. Effect of the Invention

[0007] According to the present invention, it is possible to provide a resin molded product and a method for determining deterioration of a resin molded product, which allows deterioration to be easily determined. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing an apparatus according to an embodiment of the present invention; [Diagram 2] 1A is a perspective view showing a resin molding in an undegraded state, and FIG. 1B is a perspective view showing a resin molding in a deteriorated state. [Diagram 3] This is a flowchart showing the process from the manufacturing process of resin molded products to the reuse and recycling process. [Figure 4] 1 is a graph showing the relationship between strain and stress in a resin molded product. [Diagram 5] FIG. 13 is a perspective view showing a resin molded product as a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and the duplicated description will be appropriately simplified or omitted.

[0010] As shown in FIG. 1, a device 1 is provided with a reusable resin molded product 10. The resin molded product 10 is made of a predetermined resin material (for example, PC resin, PET resin, ABS resin, etc.). Then, when the device 1 reaches the end of its useful life in the market, the device 1 is collected from the market, and the degree of deterioration of the resin molded product 10 disassembled from the device 1 at a recycling plant or the like is judged. Then, depending on the degree of deterioration, it is determined whether or not the resin molded product 10 can be reused.

[0011] In this embodiment, an image forming device such as a printer is used as the device 1, but the device 1 is not limited to this and may be any industrial product. In addition, in this embodiment, a resin exterior cover is used as the reusable resin molded product 10, but the reusable resin molded product 10 is not limited to this, and any resin molded product may be applicable. Furthermore, in this embodiment, the resin molded product 10 is a component part of the device 1 that is distributed on the market, but the resin molded product 10 may also be a product that is distributed on the market by itself. Industrial products include home appliances, electronic products, communication devices, and other electronics products, transportation equipment such as automobiles, vehicles, and elevators, unit products for kitchens and bathrooms, structures such as houses and buildings, civil engineering parts such as road signs, exterior casing parts for daily necessities, various storage containers, toys, audio equipment, beauty equipment, etc. More specifically, examples of such components include electric kettles, humidifiers, rice cookers, rice cake makers, coffee makers, and dishwashers and dryers, air conditioner components, connector housings for electrical connections in automotive wire harnesses, and storage trays for semiconductor components.

[0012] Now, referring to FIG. 2 etc., resin molded product 10 in the present embodiment is provided in a part thereof with discolored portion 20 (printed portion). The discolored portion 20 is a portion that discolors before discoloration due to deterioration occurs in the resin molded product 10. In particular, the discolored portion discolors to a color different from other portions before discoloration due to deterioration occurs in the resin molded product 10. Specifically, when no deterioration has occurred in the resin molded product 10, as shown in FIG. 2(A), the discolored portion 20 is substantially the same color (or transparent) as the other portions (portions other than the discolored portion 20), making them virtually indistinguishable. In contrast, as shown in FIG. 2(B), when external factors such as heat, ultraviolet light, temperature, and humidity are about to cause discoloration due to deterioration in the resin molded product 10 (i.e., the parts other than the discolored part 20), the discolored part 20 will significantly discolor to a different color before that occurs. Whether or not the resin molded product 10 can be reused is determined based on the presence or absence of discoloration in the discolored portion 20. That is, if there is no discoloration in the discolored portion 20, it is determined that the resin molded product 10 has not deteriorated significantly and can be reused, whereas if there is discoloration in the discolored portion 20, it is determined that the resin molded product 10 has deteriorated significantly and cannot be reused.

[0013] Such discolored portion 20 is formed to have poorer weather resistance than other portions of resin molded product 10. In other words, discoloration of discolored portion 20 due to external factors such as heat, ultraviolet light, temperature, and humidity is accelerated compared to other portions. Specifically, for example, an accelerator for accelerating discoloration, such as an ultraviolet light absorber, may be applied to or mixed into discolored portion 20, or a coating that makes discoloration less likely to occur due to external factors such as heat, ultraviolet light, temperature, and humidity may be applied to portions other than discolored portion 20.

[0014] More specifically, the deterioration determining method for the resin molded product 10 includes a determining step of determining that deterioration has occurred in the resin molded product 10 when the discolored portion 20 is discolored. This determination process includes a selection process in which the resin molded product 10 determined to be deteriorated is not considered for reuse. Specifically, resin molded products 10 that are determined to have discolored and deteriorated will not be reused, but will be discarded as is, or recycled (returned to resin material and used again as another resin molded product).On the other hand, only resin molded products 10 that are determined to have no discoloration and no deterioration will be reused.

[0015] In this way, the deterioration of the resin molded product 10 in this embodiment can be determined simply by visually checking whether or not there is discoloration in the discolored area 20 formed on the resin molded product 10, without using a measuring instrument or the like, making the determination process easy.

[0016] In this embodiment, discoloration portion 20 is formed so that the printed portion (printed portion) becomes visible when discoloration portion 20 changes to a color different from that of other portions. The printed portion (printed section) is formed so that information about the resin molded product 10 (at least one of the material, grade, lot number, and molding date of the resin molded product 10) can be read. The printed portion (printed portion) is any one of a bar code, a QR code, a number, and a symbol. In this embodiment, the QR code is formed so as to emerge in the discolored portion 20 as the deterioration of the resin molded product 10 progresses (see FIG. 2(B)).

[0017] More specifically, the discolored portion 20 (printed portion) is the same color as the other portions (or transparent) when the resin molded product 10 is not degraded, and discolors in response to factors that cause resin degradation, such as ultraviolet rays, heat, temperature and humidity, the integrated cumulative amount, and the maximum instantaneous value, and therefore discolors due to degradation caused by the influence of the above-mentioned factors, causing the QR code (printed portion) to emerge. The cumulative amount and maximum values ​​of such ultraviolet rays, heat, temperature and humidity can be easily determined by the emergence of the printed portion, making it possible to determine the deterioration of the resin molded product 10. That is, since the weather resistance of the discolored portion 20 (printed portion) to ultraviolet rays, heat, temperature and humidity, etc. is lower than that of the other resin portions, the discolored portion 20 (printed portion) becomes visible due to deterioration. The discolored portion 20 (printed portion) is a QR code (or a barcode, serial number, etc.) as a unique number for identifying the resin molded product 1, and by managing this in a separate system, it can also be used to trace the number of times it has been reused or recycled. The discolored portion 20 (printed portion) also records the original material, grade, lot number, molding date, etc. as a unique number, and information about the resin molded product 10 can be read from it. Furthermore, by providing such a discolored portion 20 (printed portion) on the resin molded product 10, it is possible to know in what environment the device 1 in which the resin molded product 10 was installed was used.

[0018] Hereinafter, a flow from the manufacturing process of the resin molded product 10 to the reuse and recycling process will be described with reference to FIG. First, when the resin molded product 10 is molded in a manufacturing factory, a desired discolored portion 20 (a QR code that appears when the color changes) is formed in a part of the resin molded product 10 (step S1). Then, the device 1 in which the resin molded product 10 with the discolored portion 20 formed therein is installed is shipped from the manufacturing factory, delivered to the market, and put into operation (step S2). Then, when the device 1 has completed its role in the market, the device 1 is collected from the market (step S3), and the resin molded product 10 is removed from the collected device and collected (step S4). Then, in the collected resin molded product 10, it is determined whether or not the QR code has lifted due to discoloration of the discolored portion 20 (step S5). As a result, if the lifting due to discoloration of the discolored portion 20 (QR code) is not visible, it is determined that there is no unacceptable deterioration of the resin molded product 10 and that the resin molded product 10 can be reused, and the resin molded product 10 itself is assembled as is into the next target device 1 (steps S6, S7). On the other hand, if the discoloration of the discolored portion 20 (QR code) is visible as lifting in step S5, it is determined that there is unacceptable deterioration of the resin molded product 10, and the resin molded product 10 is not reused but is discarded or recycled (step S8).

[0019] Note that Figure 4 is a graph showing the relationship between strain ? and stress σ in resin molded product 10, where Figure 4(A) shows the relationship when no deterioration has occurred in resin molded product 10, and Figure 4(B) shows the relationship when deterioration has occurred in resin molded product 10. 4(A), there is no deterioration in the initial state of the resin molded product 10, and when force is applied to the resin molded product 10, it undergoes elastic deformation up to a certain stress (see range X1), and when that stress is exceeded, it undergoes plastic deformation, and when the deformation becomes even larger, it finally breaks (see range X2). The stress at the time of plastic deformation or breakage at this time can be roughly regarded as the strength of the material (resin molded product 10). In contrast, as shown in Fig. 4(B), when the strength of the resin molded product 10 deteriorates over time due to the effects of heat, ultraviolet rays, temperature and humidity, for example due to a decrease in the molecular weight of the resin material, its Young's modulus (the slope of the graph within the elastic region) remains almost unchanged, but deterioration that causes sudden destruction with almost no plastic deformation occurs at a smaller stress than in a state without deterioration becomes more likely. The strength of the material (resin molded product 10) at this time becomes smaller than in a state without deterioration (the state in Fig. 4(A)). In the present embodiment, when the resin molded product 10 has deteriorated to the extent that the relationship between strain ? and stress σ is as shown in Figure 4(B), the discolored portion 20 will discolor and rise up, making it possible to grasp such a deteriorated state at a glance.

[0020] <Modification> As shown in FIG. 5, the resin molded product 10 in the modified example has a plurality of discolored portions (in this embodiment, two discolored portions: a first discolored portion 20A and a second discolored portion 20B). The first color-changing portion 20A is a color-changing portion that changes color in response to at least one of heat, ultraviolet light, temperature, and humidity (for example, heat and ultraviolet light) as an external factor. In contrast, second color changing portion 20B is a color changing portion that changes color due to at least one of heat, ultraviolet light, temperature, and humidity (for example, temperature and humidity) that is different from that of first color changing portion 20A due to an external factor. By providing a plurality of discolored portions 20A, 20B having different external factors causing discoloration in this manner, the cause of deterioration can be identified, making it easier to grasp the characteristics of the resin molded product 10. For example, in the above example, if the discoloration of the first discolored portion 20A is visible, it can be determined that the strength has deteriorated due to heat or ultraviolet rays and that reuse is difficult, and if the discoloration of the second discolored portion 20B is visible, it can be determined that the strength has deteriorated due to accelerated hydrolysis of the resin material due to temperature and humidity, and that reuse is difficult.

[0021] As described above, the resin molded product 10 in this embodiment is a resin molded product made of a predetermined resin material, and is provided with a discoloration portion 20 that changes color before discoloration occurs due to deterioration in the resin molded product 10. This makes it possible to easily determine the deterioration of the resin molded product 10.

[0022] It is clear that the present invention is not limited to the present embodiment, and that the present embodiment may be modified as appropriate within the scope of the technical concept of the present invention in addition to the modifications suggested in the present embodiment. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and may be any number, position, shape, etc. suitable for implementing the present invention. [Explanation of symbols]

[0023] 1 equipment (image forming device), 10 Resin molded products (resin exterior cover), 20 Discolored area, 20A: First discolored area; 20B: Second discolored area.

[0024] The present invention can also be embodied in the following combinations of Supplementary Notes 1 to 11. (Appendix 1) A resin molded product made of a predetermined resin material, A resin molded product comprising a discoloration portion which changes color before discoloration due to deterioration occurs in the resin molded product. (Appendix 2) The resin molded product described in Appendix 1, characterized in that the discolored portion changes color to a different color from other portions before discoloration due to deterioration occurs in the resin molded product. (Appendix 3) 3. The resin molded product according to claim 1, wherein the discolored portion makes the printed portion visible when it changes color to the different color. (Appendix 4) The resin molded product described in Appendix 3, characterized in that the printed portion is formed so that information regarding the resin molded product can be read. (Appendix 5) 5. The resin molded product according to claim 4, wherein the information is at least one of the material, grade, lot number, and molding date of the resin molded product. (Appendix 6) 6. The resin molded product according to any one of claims 3 to 5, wherein the printed portion is any one of a bar code, a QR code, a number, and a symbol. (Appendix 7) A plurality of the discolored portions are provided, The resin molded product described in any one of Appendix 1 to Appendix 6, characterized in that the multiple discoloration areas include a first discoloration area that changes color in response to at least one of heat, ultraviolet light, temperature, and humidity as an external factor, and a second discoloration area that changes color in response to at least one of heat, ultraviolet light, temperature, and humidity as an external factor different from that of the first discoloration area. (Appendix 8) 8. The resin molded product according to claim 1, wherein the discolored portion has poorer weather resistance than the other portions. (Appendix 9) 9. The resin molded product according to any one of claims 1 to 8, wherein the reusability of the resin molded product is determined based on the presence or absence of discoloration in the discolored portion. (Appendix 10) A method for determining deterioration of a resin molded product made of a predetermined resin material, comprising: the resin molding has a discoloration portion that changes color before discoloration due to deterioration occurs in other portions, A deterioration determining method for a resin molded product, comprising a determining step of determining that deterioration has occurred in the resin molded product when the discolored portion is discolored. (Appendix 11) A method for determining deterioration of a resin molded product as described in Appendix 10, characterized in that the determination process includes a sorting process in which the resin molded product determined to be deteriorated is not eligible for reuse. [Prior art documents] [Patent documents]

[0025] [Patent Document 1] JP 2005-225079 A

Claims

1. A resin molded product made of a predetermined resin material, A resin molded product comprising a discoloration portion which changes color before discoloration due to deterioration occurs in the resin molded product.

2. 2. The resin molded product according to claim 1, wherein the discolored portion changes color to a color different from other portions before discoloration due to deterioration occurs in the resin molded product.

3. 3. The resin molded product according to claim 2, wherein the printed portion becomes visible when the discolored portion changes to the different color.

4. 4. The resin molded product according to claim 3, wherein the printed portion is formed so that information regarding the resin molded product can be read.

5. 5. The resin molded product according to claim 4, wherein the information is at least one of the material, grade, lot number, and molding date of the resin molded product.

6. 6. The resin molded product according to claim 4, wherein the printed portion is any one of a bar code, a QR code, a number, and a symbol.

7. A plurality of the discolored portions are provided, The resin molded product described in claim 1 or claim 2, characterized in that the multiple discoloration areas include a first discoloration area that changes color due to at least one of heat, ultraviolet rays, temperature, and humidity as an external factor, and a second discoloration area that changes color due to at least one of heat, ultraviolet rays, temperature, and humidity as an external factor different from that of the first discoloration area.

8. 3. The resin molded product according to claim 1, wherein the discolored portion has poorer weather resistance than the other portions.

9. 3. The resin molded product according to claim 1, wherein the reusability of the resin molded product is determined based on the presence or absence of discoloration of the discolored portion.

10. A method for determining deterioration of a resin molded product made of a predetermined resin material, comprising: the resin molding has a discoloration portion that changes color before other portions change color due to deterioration, A deterioration determining method for a resin molded product, comprising a determining step of determining that deterioration has occurred in the resin molded product when the discolored portion is discolored.

11. 11. The method for determining deterioration of a resin molded product according to claim 10, wherein the determination step includes a selection step of excluding the resin molded product determined to be deteriorated from the reuse target.

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