Recycled material-containing container, and method for manufacturing a recycled material-containing container.

Abstract

We provide a gray container containing recycled materials with excellent strength. [Solution] A method for manufacturing a recycled material-containing container, comprising injection molding a gray mixed material obtained by mixing a virgin material made of polypropylene resin with a recycled material containing polypropylene resin, wherein the method includes a mixing step of mixing the recycled material with the virgin material, and the melt flow rate of the mixed material is 40 g / 10 min or more, and the Izod impact value is 8.0 kJ / m 2 Ensure that it is as described above.

Description

Technical Field

[0001] The present invention relates to a container containing a recycled material obtained by mixing a recycled material with a virgin material of a synthetic resin, and a method for manufacturing the same.

Background Art

[0002] Containers for sorting and storing parts used in factories or products sold in stores are known. Such containers may be molded by an injection molding method in which molten resin is injected into a mold and cooled and cured.

[0003] Patent Document 1 describes an invention related to an integral molding die container molding method for injection molding a container using a fixed die and a movable die. In Patent Document 1, when molding a thin-walled container in response to the demands of weight reduction and thinning of the container, a plurality of resin gates are arranged on the side wall and the bottom wall so that the flow of resin in the cavity does not become uneven. This is to ensure the fluidity of the resin and the strength of the molded product. That is, in order to ensure the fluidity of the resin in the cavity narrowed due to the demand for thinning, it is necessary to increase the melt flow rate of the resin, but there is a problem that it is difficult to ensure the strength of the molded product when the melt flow rate is increased.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, due to the growing environmental concerns in recent years, there is a demand to use recycled materials made from discarded resin as materials for molding containers. However, recycled materials generally have a lower melt flow rate. Therefore, when recycled materials are mixed with virgin materials and injection molded, a difference in melt flow rate may occur between the virgin and recycled materials, resulting in uneven fluidity. If uneven fluidity is not achieved, the compatibility between the two materials is not good. This could potentially affect the strength of the molded product.

[0006] Furthermore, the overall melt flow rate of the mixed material containing recycled materials decreases, resulting in poorer fluidity of the mixed material within the mold. This can also lead to a decrease in the strength of the molded product. The effect of the fluidity of the mixed material is particularly pronounced when molding thin-walled containers for weight reduction. Thus, the problem of maintaining the strength of the molded product while increasing the melt flow rate is common to recycled material-containing containers that use recycled materials.

[0007] Furthermore, recycled materials contain various resin materials, resulting in a darker color. If the same color tone as containers molded from regular virgin materials cannot be achieved, the resulting mix of containers in various colors will be inconvenient to use. [Means for solving the problem]

[0008] To solve the above problems, the present invention provides a method for manufacturing a recycled material-containing container, comprising injection molding a gray mixed material obtained by mixing a recycled material containing polypropylene resin with a virgin material made of polypropylene resin, wherein the method comprises a mixing step of mixing the recycled material with the virgin material, and the melt flow rate is 40 g / 10 min or more, and the Izod impact value is 8.0 kJ / m 2 The above-mentioned mixed material is prepared.

[0009] In the above configuration, it is preferable that in the mixing step, the recycled material modified by adding organic peroxides in an amount of 0.2% by mass or more and 1.5% by mass or less is mixed. In the above configuration, the mixing step involves mixing the recycled material, thereby increasing the specific gravity of the mixed material to 0.89 g / cm³. 3 More than 0.93g / cm 3 It is preferable that the following conditions be met.

[0010] To solve the above problems, the recycled material-containing container of the present invention is a gray recycled material-containing container made by mixing a virgin material made of polypropylene resin with a recycled material containing polypropylene resin, and has a specific gravity of 0.89 g / cm³. 3 More than 0.93g / cm 3 The following is L, which represents brightness. * The value is between 36 and 65, the flexural modulus is 1100 MPa or higher, and the Izod impact value is 8.0 kJ / m 2 That's all.

[0011] In the above configuration, it is preferable that the melt flow rate is 40 g / 10 min or more. [Effects of the Invention]

[0012] According to the present invention, a gray recycled material-containing container with excellent strength can be obtained. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a perspective view of the container according to this embodiment. [Modes for carrying out the invention]

[0014] The following describes a recycled material-containing container, which is one embodiment of the present invention. The recycled material-containing container 1 of this embodiment (hereinafter referred to as "container 1") is used, for example, to sort and store parts used in an assembly plant according to their specifications.

[0015] <About Container 1> As shown in Figure 1, container 1 consists of a bottom wall 11 and four side walls 12, and is a rectangular box-shaped body with dimensions of approximately 25 cm × 50 cm × 25 cm. The upper part of the side walls 12 forms an opening that opens upward. Six protrusions 14 reinforced with ribs 13 are formed on the bottom surface of the bottom wall 11. All six protrusions 14 are the same shape and size. Grooves 15 are formed between the protrusions 14, extending perpendicularly to each other. The width of the grooves 15 is the same.

[0016] The container 1 of this embodiment is a modular container 1 that can be used in a modular fashion. Multiple containers 1 can be stacked, and it is also possible to stack containers 1 of different sizes. In the case of containers 1 of different sizes, for example, it is a cubic box, and four protrusions 14 of the same shape and size are formed on the bottom surface of the bottom wall 11. Preferably, the length-to-width ratio of the bottom wall 11 of the container 1 is up to about 6.0 times. In order to use the container 1 in a modular fashion, a group of square-shaped ribs 13 are formed on the protrusions 14. Also, in order to use it in a modular fashion, the colors need to be unified.

[0017] When stacking multiple containers 1, the upper end of the side wall 12 of the lower container 1 fits into a groove 15 that extends along the outer circumference of the bottom wall 11 of the upper container 1. Furthermore, since the groove 15 extends perpendicularly, it is also possible to stack multiple containers 1 with a horizontal offset.

[0018] Container 1 is a so-called thin-wall container, with relatively thin side walls 12. The wall thickness of the side walls 12 is preferably about 1.7 to 2.9 mm, and more preferably about 1.9 to 2.5 mm. To reinforce the side walls 12, multiple vertical flanges 16 extending in the vertical direction and horizontal flanges 17 extending in the horizontal direction are formed on the side walls 12. The vertical flanges 16 and horizontal flanges 17 are formed to be thicker than the side walls 12. This improves the strength of container 1.

[0019] Container 1 is manufactured by injection molding a mixed material obtained by mixing a virgin material made of polypropylene resin with a recycled material (hereinafter sometimes referred to as modified recycled material) which contains polypropylene resin and has been modified by adding organic peroxides.

[0020] Furthermore, recycled materials generally contain polyethylene and polyvinyl chloride in addition to polypropylene. When these resins are mixed in, the mixed material may not flow uniformly during the molding of container 1. In addition, since the bottom surface of container 1 has alternating protrusions 14 and recesses 15, the flow of resin injected from the gate is not consistent. For this reason, the width of the recesses 15 is set to more than twice the length of the ribs 13 in order to stabilize the flow of the mixed material in the recesses 15 and facilitate its flow to the ribs 13. Also, the thickness at the base of the ribs 13 is greater than the thickness of the bottom wall 11. This is because the recycled material, when mixed in, is more prone to deformation than when only virgin material is used. Furthermore, the difference in shrinkage also makes it more prone to deformation.

[0021] Recycled materials are used after processing discarded synthetic resin products, such as by crushing. Recycled materials may contain polypropylene resin as the main component, along with other materials such as polyethylene resin and polyvinyl chloride resin, or even if they are polypropylene resins, they may be unevenly mixed with block polypropylene resin, random polypropylene resin, or homopolypropylene resin. Therefore, container 1 mixed with recycled materials will have a different color tone and inferior mechanical properties such as fluidity, flexural strength, and impact resistance compared to a container made only of virgin material.

[0022] Generally, recycled materials have a low brightness and are close to black because they contain a mixture of synthetic resin materials of different shades. On the other hand, conventional gray containers that are injection-molded from virgin materials to sort and store parts according to specifications have a low brightness, represented by the color L. *The value is about 45 to 60. From the perspective of being easy to use even when used with a conventional container injection-molded only from virgin material and being useful as a substitute for a conventional container, the container 1 of the present embodiment is molded using a mixed material in which a recycled material (modified recycled material) is mixed with a virgin material. L representing the lightness of the modified recycled material * The value is preferably 36 or more and less than 70, more preferably 36 or more and less than 65, and even more preferably 45 or more and less than 60.

[0023] Also, the lightness of the mixed material, that is, the lightness of the container 1 obtained by injection-molding a mixed material in which a modified recycled material is mixed with a virgin material is L * The value is preferably 36 or more and less than 70, more preferably 36 or more and less than 65, and even more preferably 45 or more and less than 60. L * When the value is within this range, it has the same lightness as a container made only of a conventional virgin material and is easy to use.

[0024] The specific gravity of the virgin material of polypropylene is 0.9 g / cm 3 whereas the specific gravity of the mixed material, that is, the specific gravity of the container 1 is preferably 0.89 g / cm 3 or more and 0.93 g / cm 3 or less.

[0025] When injection-molding the container 1 shown in FIG. 1, for example, in an injection mold, a molten resin material (mixed material) is injected into the cavity from a resin gate formed at a position corresponding to the central portion of the bottom wall 11. Therefore, if the fluidity of the mixed material is low, the molten resin will not sufficiently spread in the cavity, causing a deterioration in the quality of the molded product. This is particularly prominent when the container 1 is large or the wall thickness is thin. In the container 1 of the present embodiment, for reinforcement, the vertical flange 16 and the horizontal flange 17 are formed thicker than the side wall 12. Therefore, good fluidity is required also from the point that a large amount of resin needs to flow.

[0026] From the viewpoint of ensuring sufficient distribution of the mixed material, which is a mixture of virgin material and modified recycled material, within the cavity to secure the strength of the molded product, the container 1 of this embodiment is molded using a mixed material in which modified recycled material, which has been modified by adding organic peroxides, is mixed with virgin material. This brings the melt flow rate (MFR), which indicates the fluidity of the modified recycled material, closer to that of the virgin material, while also setting the MFR of the mixed material above a predetermined value. By bringing the MFR of the modified recycled material closer to that of the virgin material, the compatibility between the modified recycled material and the virgin material is improved, and a decrease in the physical properties of the molded container 1 can be suppressed.

[0027] The MFR of the modified and recycled material is preferably 20 g / 10 min or more, and more preferably 40 g / 10 min or more. When the MFR of the modified and recycled material is within this range, it has good compatibility with the virgin material. It can suppress uneven mixing when the modified and recycled material is mixed with the virgin material.

[0028] Furthermore, the MFR of the mixed material is preferably 40 g / 10 min or more. In other words, the MFR of the resin constituting the molded container 1 is preferably 40 g / 10 min or more.

[0029] On the other hand, when recycled materials are modified by adding organic peroxides, the mechanical properties of the molded container 1, such as bending strength and impact strength, may be inferior. Therefore, the amount of organic peroxide added needs to be adjusted in balance with the MFR value and the mechanical properties of the molded product.

[0030] The amount of organic peroxide added to the recycled material is preferably 0.2% to 1.5% by mass, more preferably 0.2% to 0.8% by mass, and even more preferably 0.2% to 0.6% by mass, per 100 parts by mass of the recycled material. When the amount of organic peroxide added is within this range, the MFR of container 1 is 40 or more, the flexural modulus is 1100 MPa or more, and the Izod impact value is 8 kJ / m 2The above can be achieved. If the organic peroxide content is 1.5% by mass or less, the decrease in impact strength of container 1 can be suppressed.

[0031] Furthermore, the amount of organic peroxide added to recycled materials can be reduced if the following two equations are satisfied. (Formula 1)A>B×0.25 (Formula 2)(A×a / 100)+(B×b / 100)>B×0.8 Here, A represents the MFR of recycled material, a represents the amount of recycled material blended, B represents the MFR of virgin material, and b represents the amount of virgin material blended.

[0032] <About the manufacturing method of Container 1> Next, we will explain the manufacturing method of container 1, along with its operation. The manufacturing method for container 1 comprises a modification step of modifying recycled material, a mixing step of mixing the modified recycled material with virgin material, and a molding step of injecting the mixed material into a mold and performing injection molding.

[0033] In the modification process, an organic peroxide is added to the recycled material to obtain a modified recycled material. Furthermore, as described above, the amount of organic peroxide added is preferably 0.2% by mass or more and 1.5% by mass or less per 100 parts by mass of the recycled material, more preferably 0.2% by mass or more and 0.8% by mass or less, and even more preferably 0.2% by mass or more and 0.6% by mass or less.

[0034] In the mixing process, the modified and recycled material is added to the virgin material and kneaded. The kneading temperature is preferably around 200-250°C. The modified and recycled material has a higher MFR due to the addition of organic peroxides, and the difference in MFR between it and the virgin material is small, resulting in good compatibility with the virgin material and suppression of uneven mixing.

[0035] In the molding process, for example, a mold consisting of a fixed mold and a movable mold is set up, with a resin gate formed at a position corresponding to the central part of the bottom wall 11 of the container 1. After clamping the mold, a molten mixed material is injected into the formed cavity through the resin gate.

[0036] The mold used in the molding process of this embodiment has a flow length of L from the resin gate to the end of the container 1, where L is the flow length and T is the thickness of the cavity, with L / T being 250 or more. In other words, the wall thickness of the bottom wall 11 and the side walls 12 are relatively thin compared to the size of the container 1. In this regard, since the MFR of the mixed material is prepared to be 40 g / 10 min or more, the mixed material spreads from the resin gate, which is located at a position corresponding to the central part of the bottom wall 11, toward the region in the cavity corresponding to the bottom wall 11 and the region corresponding to the side walls 12. With mixing unevenness suppressed, it also spreads to the regions corresponding to the ribs 13 of the protrusions 14 and the vertical flanges 16 and horizontal flanges 17 of the side walls 12. In this way, the mixed material is evenly distributed to the end of the cavity. After that, the container 1 is obtained by cooling the mold and demolding.

[0037] The following effects can be obtained with the container 1 and its manufacturing method according to this embodiment. (1) Container 1 is formed by injection molding of a gray mixed material which is a mixture of virgin material made of polypropylene resin and modified recycled material containing polypropylene resin. The mixed material constituting Container 1 has a specific gravity of 0.89 g / cm³. 3 More than 0.93g / cm 3 The following is L, which represents brightness. * The value is between 36 and 65. Also, the Izod impact value is 8.0 kJ / m 2 That concludes the explanation. Therefore, although Container 1 contains recycled materials, it has a hue (brightness) and strength comparable to that of a container molded solely from virgin materials.

[0038] (2) The melt flow rate of container 1 is 40 g / 10 min or more. Because it is injection molded with a mixed material having such a melt flow rate, the resin spreads well within the mold, and a container 1 with excellent moldability is obtained.

[0039] (3) In the manufacturing method of container 1, in the mixing step in which virgin material is mixed with recycled material, modified recycled material to which organic peroxide has been added is mixed. As a result the melt flow rate of the mixed material is 40 g / 10 min or more, and the Izod impact value of container 1 is 8.0 kJ / m 2 This is how it is designed. As a result, it is possible to manufacture a gray container 1 with superior strength.

[0040] (4) In the mixing process, modified recycled material is mixed in which organic peroxides are added in an amount of 0.2% by mass or more and 1.5% by mass or less. As a result, a mixed material with excellent fluidity can be obtained with an MFR of 40 g / 10 min or more.

[0041] (5) In the mixing process, the specific gravity of the mixed materials is 0.89 g / cm³. 3 More than 0.93g / cm 3 The following is the result. Therefore, L represents the brightness of container 1. * Values ​​between 35 and 65 can be represented as gray.

[0042] The above embodiment can be modified as follows. Note that the above embodiment and the following modifications can be combined and applied to the extent that they do not contradict each other technically. The shape of container 1 is not limited to that shown in Figure 1. The vertical flange 16 and horizontal flange 17 may be omitted. Also, the protrusion 14 and recessed groove 15 may be omitted.

[0043] The size and wall thickness of Container 1 are not limited to those mentioned above. • As for the mold, it is not necessary to use one in which a resin gate is formed in the central part of the bottom wall 11. Alternatively, a mold with multiple resin gates may be used, or a mold with multiple resin gates formed only on the bottom wall 11 may be used.

[0044] The specific gravity of virgin material made from polypropylene resin is 0.89 g / cm³. 3 More than 0.93g / cm 3 The following range is also acceptable. The specific gravity of the modified and recycled material is 0.89 g / cm³. 3 More than 0.93g / cm 3 The following range is also acceptable.

[0045] The specific gravity of the modified and recycled material may be equivalent to that of the virgin material made of polypropylene resin. · Virgin material consisting of modified recycled material and polypropylene resin is L * The difference in values ​​is 1 to 10, specific gravity (g / cm³). 3 The difference between ) may be in the range of 0.001 to 0.040, the difference between Izod impact values ​​may be in the range of 0.1 to 5.0, and the difference between MFR (g / 10min) may be in the range of 1.0 to 10.0.

[0046] The difference between the modified recycled material and the virgin material made of polypropylene resin may be in the range of 1 to 30 for flexural modulus, 1.0 to 5.0 for flexural strength, and 0.1 to 2.0 for weld strength.

[0047] The technical concepts that can be understood from the above embodiments are described below. (i) A method for manufacturing a recycled material-containing container, comprising injection molding a gray mixed material obtained by mixing a virgin material made of polypropylene resin with a recycled material containing polypropylene resin, wherein the method comprises a mixing step of mixing the virgin material with the recycled material, and in the mixing step, the recycled material is modified by adding organic peroxides in an amount of 0.2% by mass or more and 1.5% by mass or less, so that the melt flow rate of the mixed material is 40 g / 10 min or more and the lightness is L *The value should be between 45 and 65, and the flexural modulus of the recycled material-containing container should be 1100 MPa or higher, with an Izod impact value of 8.0 kJ / m 2 A method for manufacturing a recycled material-containing container, characterized in that the above conditions are met.

[0048] (b) A method for manufacturing a recycled material-containing container having a reinforcing flange formed on the side wall by injection molding a gray mixed material obtained by mixing a virgin material made of polypropylene resin with a recycled material containing polypropylene resin, comprising a mixing step of mixing the virgin material with the recycled material to obtain a mixed material, and a molding step of injecting the mixed material into a mold and injection molding, wherein in the molding step, a mold is used in which the L / T ratio is 250 or more, when the maximum flow length from the resin gate is L and the thickness of the cavity is T, and in the mixing step, the recycled material is mixed in which organic peroxide is added and modified to be 0.2% by mass or more and 1.5% by mass or less, so that the melt flow rate of the mixed material is 40 g / 10 min or more and the lightness L * The value should be between 45 and 65, and the flexural modulus of the recycled material-containing container should be 1100 MPa or higher, with an Izod impact value of 8.0 kJ / m 2 A method for manufacturing a recycled material-containing container, characterized in that the above conditions are met.

[0049] (h) A gray recycled material-containing container made by mixing a virgin material made of polypropylene resin with a modified recycled material containing polypropylene resin, wherein the ratio of the maximum length from the resin gate mark to the thickness of the side wall is 250 or more, the melt flow rate is 40 g / 10 min or more, and the specific gravity is 0.89 g / cm³ 3 More than 0.93g / cm 3 The following is L, which represents brightness. * The value is between 36 and 65, the flexural modulus is 1100 MPa or higher, and the Izod impact value is 8.0 kJ / m 2 A recycled material-containing container characterized by the above. [Examples]

[0050] <Modification of Recycled Materials with Organic Peroxides> The properties and mechanical characteristics of the modified recycled materials were evaluated when organic peroxides were added to the recycled materials. Also, the properties and mechanical characteristics of the mixed materials were evaluated when the modified recycled materials were mixed with virgin materials. The MFR of the recycled materials before modification was 7.7 g / 10 min, the flexural modulus was 1150 MPa, and the Izod impact value was 5.7 kJ / m 2 It was.

[0051] Perbutyl (registered trademark) P-40 (manufactured by NOF Corporation) was used as the organic peroxide. The recycled materials were modified by adding the organic peroxide at 0.1, 0.3, 0.5, and 0.7 mass%, respectively. For the organic peroxide-modified recycled materials after adding the organic peroxide, the MFR, flexural modulus, and Izod impact value were measured, respectively.

[0052] Also, the modified recycled materials were mixed with virgin polypropylene materials at 30 mass% to prepare mixed materials. The MFR of the virgin material was 52.7 g / 10 min. For the mixed materials, the MFR, flexural modulus, and Izod impact value were measured, respectively.

[0053] <Measurement of MFR> In accordance with JIS K7210, it was measured using a melt indexer tester under the conditions of a temperature of 230 °C and a load of 2.16 kg.

[0054] The evaluation criteria for the MFR of the modified recycled materials are as follows. 〇: The MFR is 40 g / 10 min or more, and the compatibility with the virgin material is good. △: The MFR is 20 g / 10 min or more and less than 40 g / 10 min, and the compatibility with the virgin material is generally good. ×: The MFR is less than 20 g / 10 min, and the compatibility with the virgin material is not good.

[0055] The evaluation criteria for the MFR of the mixed materials are as follows. ○; The MFR is 40g / 10min or higher, indicating good fluidity during injection molding. ×; The MFR is less than 40g / 10min, indicating poor fluidity during injection molding.

[0056] <Measurement of flexural modulus> Measurements were taken using an autograph tester in accordance with JIS K7171, under the following conditions: test speed 10 mm / min, support distance 60 mm, support base radius 5 mm, and indenter radius 5 mm.

[0057] The evaluation criteria for the flexural modulus of mixed materials are as follows: ○; The flexural modulus is 1100 MPa or higher, and the flexural strength of the molded product is good. ×; The flexural modulus is less than 1100 MPa, and the flexural strength of the molded product is not good.

[0058] <Measurement of Izod impact value> The measurement was performed in accordance with JIS K7110, using an Izod impact tester, under conditions of a hammer weighing capacity of 2.75 J.

[0059] The evaluation criteria for Izod impact values ​​for mixed materials are as follows: ○; Izod impact value is 8 kJ / m 2 In conclusion, the molded product exhibits good fracture strength against impact. △; Izod impact value is 7 kJ / m 2 More than 8kJ / m 2 The value is less than [value missing], and the fracture strength of the molded product against impact is not good. ×; Izod impact value is 7 kJ / m 2 The value is less than [value missing], and the fracture strength of the molded product against impact is not good.

[0060] The results for the properties and mechanical characteristics are shown in Table 1.

[0061] [Table 1] As shown in Table 1, when organic peroxides were added to the recycled material at a concentration of 0.2% by mass or more, the MFR of the modified recycled material was 20 g / 10 min or more, indicating generally good compatibility with the virgin material. Furthermore, when organic peroxides were added to the recycled material at a concentration of 0.3% by mass or more, the MFR of the mixed material, obtained by mixing the modified recycled material with the virgin material, was 40 g / 10 min or more, indicating good fluidity.

[0062] On the other hand, if the amount of organic peroxide added to the recycled material is 1.5% by mass or less, the flexural modulus of the mixed material will be 1100 MPa or higher, and the Izod impact value will be 7 kJ / m 2 The above results indicate that the mechanical properties of the molded product were satisfactory. In particular, when the amount of organic peroxide added was 0.6% by mass or less, the flexural modulus was 1100 MPa or higher and the Izod impact value was 8 kJ / m 2 As a result, the mechanical strength of the molded product has been further improved.

[0063] <L of mixed materials * value, a * value, b * Measurement of values ​​and specific gravity > L * value, a * value, b * Three types of modified and recycled materials with different values ​​(each value is shown in Table 2) were mixed with virgin polypropylene material in amounts of 30, 50, and 80% by mass to prepare a mixed material. * The value is 57.47, a * The value is -1.59, b * The value was 1.17. For each of the mixed materials, L * value, a * value, b * The values ​​and specific gravity were measured.

[0064] Note that virgin material a * The value is preferably in the range of -3 to +3. Also, for virgin material b * The value is preferably in the range of -2 to +4. <L * Measurement of values ​​> In accordance with JIS Z8722, a spectrophotometer was used to measure L in the color space. *The value was measured.

[0065] L of mixed material * The evaluation criteria (brightness judgment) for the values ​​are as follows: ◎;L * A value between 45 and 60 indicates a gray color, similar to virgin material. 〇;L * The value is between 36 and 45, resulting in a slightly darker gray than virgin material, or L * A value between 60 and 65 results in a slightly lighter gray color than virgin material. △;L * A value between 65 and 70 indicates a slightly lighter gray color than virgin material. ×;L * The value is less than 36, and the whole thing becomes dark, or L * The value is 70 or higher, and the overall appearance becomes whitish.

[0066] <Measurement of specific gravity> Measurements were taken using an electronic hydrometer in accordance with JIS K7112. L of mixed material * value, a * value, b * The values ​​and specific gravities are shown in Table 2.

[0067] [Table 2] From the results in Table 2, L * value, a * value, b * Mixed materials obtained by mixing modified recycled materials with different values ​​with virgin polypropylene material all have a L value. * The value was between 45 and 60, resulting in a brightness level similar to that of virgin material. [Explanation of Symbols]

[0068] 1…Container 11...Bottom wall 12…Side wall 16…Vertical flange 17…Side flange

Claims

1. A method for manufacturing a recycled material-containing container, comprising injection molding a gray mixed material obtained by mixing a virgin material made of polypropylene resin with a recycled material containing polypropylene resin, The process includes a mixing step of mixing the virgin material with the recycled material, The melt flow rate is 40 g / 10 min or higher, and the Izod impact value is 8.0 kJ / m². ２ A method for producing a recycled material-containing container, characterized by preparing the above-mentioned mixed material.

2. The method for producing a recycled material-containing container according to claim 1, characterized in that the recycled material, which has been modified by adding organic peroxides in an amount of 0.2% by mass or more and 1.5% by mass or less, is mixed in the mixing step.

3. In the mixing step, by mixing the recycled material, the specific gravity of the mixed material becomes 0.89 g / cm³. ３ 0.93g / cm or more ３ A method for producing a recycled material-containing container according to claim 2, characterized in that the following is achieved.

4. A gray recycled material-containing container made by mixing virgin material made of polypropylene resin with recycled material containing polypropylene resin, having a specific gravity of 0.89 g / cm³. ３ 0.93g / cm or more ３ The following is L, which represents brightness. ＊ The value is gray (35 or more and less than 65), the flexural modulus is 1100 MPa or more, and the Izod impact value is 8.0 kJ / m ２ A recycled material-containing container characterized by the above.

5. The recycled material-containing container according to claim 4, characterized in that the melt flow rate is 40 g / 10 min or more.

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