Regeneration method of waste polysiloxane box

Abstract

A method for regenerating a waste polysiloxane cassette according to an embodiment of the present application comprises the steps of: pulverizing a waste polysiloxane cassette comprising high density polyethylene (HDPE) and a polysiloxane sealant; carrying out surface friction processing on the waste polysiloxane box; and regenerating high density polyethylene (HDPE) from the waste polysiloxane cassette, in which the surface friction processing comprises: placing the crushed waste polysiloxane cassette into a driver, and generating friction on the surface of the waste polysiloxane cassette using the driver.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0081056 filed in the Korean Intellectual Property Office on June 23, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to a method for regenerating waste polysiloxane cartridges. Background Art

[0003] Waste silicone cartridges are generated at construction sites. The waste silicone cartridges contain high-density polyethylene (HDPE), a high-value material that can be used in a variety of applications, and silicone sealant.

[0004] That is, the method of regenerating the waste polysiloxane cartridge refers to a method of obtaining high-density polyethylene (HDPE) from the waste polysiloxane cartridge. However, there are problems in the regeneration of high-density polyethylene (HDPE) due to the adhesive polysiloxane sealant in the waste polysiloxane cartridge. Therefore, the discarded polysiloxane cartridge is landfilled or incinerated instead of being regenerated.

[0005] Therefore, after the waste silicone cartridges are separately recovered, a process of removing the silicone sealant is required.

[0006] However, the existing process consumes a lot of energy, and there is a problem that the impact strength and durability of high-density polyethylene (HDPE) obtained by the recycling method of the waste polysiloxane cartridges are reduced due to foreign matter mixed in the process of recycling the waste polysiloxane cartridges.

[0007] Therefore, there is a need to develop a method for regenerating waste polysiloxane cartridges that uses little energy and has improved impact strength and durability of high-density polyethylene (HDPE) obtained by the method. Summary of the invention

[0008] Technical issues

[0009] An object of the present invention is to provide a method for regenerating waste polysiloxane boxes, which can reduce unnecessary energy consumption by using energy within a certain range in the surface friction processing step, and can improve the impact strength and durability of high-density polyethylene (HDPE) obtained by the method for regenerating waste polysiloxane boxes.

[0010] Technical Solution

[0011] According to an exemplary embodiment of the present invention, a method for regenerating a waste polysiloxane box is provided, the method comprising: crushing a waste polysiloxane box containing high-density polyethylene (HDPE) and a polysiloxane sealant; performing surface friction processing on the waste polysiloxane box; and recovering high-density polyethylene (HDPE) from the waste polysiloxane box, wherein the surface friction processing comprises: placing the crushed waste polysiloxane box into a drive, and generating friction on the surface of the waste polysiloxane box by the drive.

[0012] Furthermore, another exemplary embodiment of the present invention provides a recycled high-density polyethylene satisfying Formula 1.

[0013] [Formula 1]

[0014] X=(A×0.03)+(B×0.05)+(C×0.1)<200

[0015] In formula 1,

[0016] X is the foreign matter score of the recycled high-density polyethylene,

[0017] A is the number of foreign matters with a size of 100 μm or more and less than 300 μm in the recycled high-density polyethylene,

[0018] B is the number of foreign matters with a size of 300 μm or more and less than 500 μm in the recycled high-density polyethylene, and

[0019] C is the number of foreign matters having a size of 500 μm or more in the recycled high-density polyethylene.

[0020] Beneficial Effects

[0021] The method of regenerating a waste polysiloxane cartridge according to an exemplary embodiment of the present invention has excellent energy efficiency.

[0022] The high-density polyethylene (HDPE) obtained by the method of regenerating a waste polysiloxane cartridge according to an exemplary embodiment of the present invention has excellent impact strength and durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The sequence of a method for regenerating a discarded silicone cartridge according to an exemplary embodiment of the present invention is schematically shown.

[0024] Figure 2 The figures show the waste silicone box before and after pulverization.

[0025] Figure 3 This is a graph showing the correlation between the total amount of energy applied to the waste silicone cartridges and the foreign matter score of the recovered high-density polyethylene in Examples and Comparative Examples.

[0026] Figure 4 This is a graph showing the correlation between the foreign matter score and the impact strength of the high-density polyethylene recovered in Examples and Comparative Examples.

[0027] Figure 5 This is a graph showing the correlation between the foreign matter score and ESCR of high-density polyethylene recovered in Examples and Comparative Examples. DETAILED DESCRIPTION

[0028] Hereinafter, the present specification will be described in more detail.

[0029] In the present specification, when a component is referred to as “including, comprising, etc.” a certain component, unless explicitly described otherwise, it means that the component may further include another component, not excluding the other component.

[0030] In this specification, “p to q” means a range of “p or more and q or less”.

[0031] In the present specification, "waste polysiloxane cartridge" refers to a material containing high-density polyethylene (HDPE) and a polysiloxane sealant, and the material obtained by the method of regenerating the waste polysiloxane cartridge is high-density polyethylene (HDPE).

[0032] Method for regenerating waste polysiloxane cartridges

[0033] According to an exemplary embodiment of the present invention, a method for regenerating a waste polysiloxane box includes the following steps: crushing a waste polysiloxane box containing high-density polyethylene (HDPE) and a polysiloxane sealant; performing surface friction processing on the waste polysiloxane box; and recovering high-density polyethylene (HDPE) from the waste polysiloxane box, wherein the surface friction processing includes: placing the crushed waste polysiloxane box into a driver, and using the driver to generate friction on the surface of the waste polysiloxane box.

[0034] In an exemplary embodiment of the present invention, the waste silicone box refers to a box that has been used as a packaging container for silicone sealant for construction or industrial use.

[0035] In an exemplary embodiment of the present invention, the total amount of energy applied to the waste silicone box during the surface friction processing step may be 35 J / kg to 100 J / kg.

[0036] The present invention provides a method for regenerating a waste polysiloxane box including a surface friction processing step. More specifically, the present invention has the following characteristics, namely, by applying a certain amount of energy relative to the weight of the waste polysiloxane box during the surface friction processing, a high-density polyethylene (HDPE) having excellent impact strength and ESCR (environmental stress crack resistance) is obtained.

[0037] Specifically, in an exemplary embodiment of the present invention, the surface friction processing step may include the steps of placing the pulverized waste silicone box into a driver, and generating friction on the surface of the waste silicone box using the driver.

[0038] In this case, the step of generating friction on the surface of the waste silicone box using the driver may include: the step of bringing the driver into contact with the surface of the waste silicone box; and the step of rotating the driver in a state where the driver is brought into contact with the surface of the waste silicone box.

[0039] That is, the friction heat generated by the mutual friction between the driver and the crushed waste silicone box can soften a part of the workpiece around the tool, and the plastic flow generated by the rotation of the driver can modify the surface. That is, in the process of generating friction, a certain amount of energy is applied to the waste silicone box.

[0040] In an exemplary embodiment of the present invention, the amount of energy applied to the waste polysiloxane box due to friction may be 35 J / kg to 100 J / kg, 40 J / kg to 100 J / kg, or 50 J / kg to 100 J / kg. In other words, the energy represents the amount of energy applied to the waste polysiloxane box by surface friction based on 1 kg of the waste polysiloxane box as the object of surface friction. That is, the fact that the amount of energy applied to the waste polysiloxane box due to friction is 35 J / kg means that in the case of surface friction processing of 1 kg of the waste polysiloxane box, the amount of energy applied to the waste polysiloxane box is 35 J.

[0041] Here, the driver is included in the surface friction processing device, corresponding to a component that accommodates the waste polysiloxane box and generates friction on the surface of the waste polysiloxane box. In addition, in this specification, the surface friction processing step can use a surface friction processing device commonly used in the relevant field. The surface friction processing step refers to processing an object by using surface friction.

[0042] In an exemplary embodiment of the present invention, in the step of feeding the crushed waste polysiloxane box into the driver, the crushed waste polysiloxane box may be fed into the driver at a rate of 500 kg / hr to 1500 kg / hr, preferably, at a rate of 550 kg / hr to 1200 kg / hr.

[0043] In an exemplary embodiment of the present invention, in the step of crushing the waste polysiloxane box containing high-density polyethylene (HDPE) and the polysiloxane sealant, the waste polysiloxane box can be crushed into pieces of a size of 20 mm or less. Here, the size of the waste polysiloxane box refers to the longest length from one end to the other end of the waste polysiloxane box.

[0044] The method of shredding the waste polysiloxane box may be compression, impact, cutting or impact cutting, etc., which are commonly used methods in the art.

[0045] In an exemplary embodiment of the present invention, before the step of pulverizing the waste silicone box containing high-density polyethylene (HDPE) and the silicone sealant, a step of solidifying the silicone sealant of the waste silicone box may be further included.

[0046] In an exemplary embodiment of the present invention, the step of hardening the silicone sealant of the waste silicone box can be performed by adding a silicone hardener, UV (ultraviolet) treatment or heat treatment, but is not limited thereto, and various methods can be used as long as they do not affect the composition of high-density polyethylene.

[0047] In an exemplary embodiment of the present invention, the step of recovering high-density polyethylene (HDPE) from the waste polysiloxane box may include the following steps: putting the waste polysiloxane box into water, separating the waste polysiloxane box into high-density polyethylene (HDPE) and polysiloxane sealant by wet specific gravity; recovering high-density polyethylene (HDPE); and drying high-density polyethylene. That is, the waste polysiloxane box containing high-density polyethylene (HDPE) and polysiloxane sealant is crushed, the crushed waste polysiloxane box is subjected to surface friction processing and then put into water, and the high-density polyethylene (HDPE) is recovered by wet specific gravity separation.

[0048] Specifically, when the waste polysiloxane box that has been subjected to surface friction processing is placed in water, the high-density polyethylene in the waste polysiloxane box floats on the water, and the polysiloxane sealant sinks. In other words, the high-density polyethylene exists in the upper part of the water, and the polysiloxane sealant exists in the lower part of the water.

[0049] Then, when the high-density polyethylene present in the upper part of the water is recovered, the purpose of the method of regenerating the spent silicone cartridge can be achieved.

[0050] The silicone sealant that is present, ie, the lower portion that has sunk into the water, may be removed.

[0051] That is, the method of regenerating a waste polysiloxane cartridge according to an exemplary embodiment of the present invention may also discard the step of discarding the polysiloxane sealant.

[0052] In an exemplary embodiment of the present invention, the step of discarding the polysiloxane sealant may include the steps of: placing the waste polysiloxane box in water to separate the waste polysiloxane box into high density polyethylene (HDPE) and the polysiloxane sealant by specific gravity; and recovering and discarding the polysiloxane sealant.

[0053] In an exemplary embodiment of the present invention, the step of drying the high-density polyethylene may be performed at a temperature of 70° C. to 90° C., and preferably 75° C. to 85° C. The moisture of the recycled high-density polyethylene is removed by the step of drying the high-density polyethylene. By removing the moisture, the efficiency of the subsequent step of extruding the high-density polyethylene (HDPE) can be further improved.

[0054] In an exemplary embodiment of the present invention, a step of extruding the recycled high-density polyethylene (HDPE) may also be included. Extrusion may also facilitate the use of the high-density polyethylene as a practical product.

[0055] Specifically, in the exemplary embodiment of the present invention, in the step of extruding the recycled high density polyethylene (HDPE), the high density polyethylene (HDPE) may be extruded at a temperature of 190°C to 220°C.

[0056] That is, Figure 1 As shown, the method for regenerating a waste polysiloxane box according to an exemplary embodiment of the present invention may include: a process of curing the polysiloxane sealant of the waste polysiloxane box; a process of crushing the cured waste polysiloxane box; a process of performing surface friction processing on the crushed waste polysiloxane box; a process of recovering high-density polyethylene by performing wet specific gravity separation on the surface friction processed waste polysiloxane box; a process of drying the recovered high-density polyethylene; and a process of extruding the recovered high-density polyethylene. In this case, the processes of crushing the waste polysiloxane box, performing surface friction processing on the crushed waste polysiloxane box, and recovering high-density polyethylene by performing wet specific gravity separation on the surface friction processed waste polysiloxane box can be said to be key processes in the method for regenerating the waste polysiloxane box.

[0057] Recycled high-density polyethylene (HDPE)

[0058] Another exemplary embodiment of the present invention provides a recycled high-density polyethylene satisfying the following Formula 1.

[0059] [Formula 1]

[0060] X=(A×0.03)+(B×0.05)+(C×0.1)<200

[0061] In the above formula 1,

[0062] X is the foreign matter score of the recycled high-density polyethylene,

[0063] A is the number of foreign matter with a size of 100 μm or more and less than 300 μm in the recycled high-density polyethylene,

[0064] B is the number of foreign matter with a size of 300 μm or more and less than 500 μm in the recycled high-density polyethylene, and

[0065] C is the number of foreign matter with a size of 500 μm or more in the recycled high-density polyethylene.

[0066] The inventors have found that larger foreign matter in recycled high-density polyethylene (HDPE) can have an adverse effect on the cantilever impact strength, environmental stress crack resistance (ESCR), etc. of the high-density polyethylene (HDPE). Therefore, a factor that can reflect the size of the foreign matter is set according to the size of the foreign matter.

[0067] More specifically, the foreign matter score of recycled high-density polyethylene (HDPE) can be measured based on the gel counter method using Collin's Q film software. Specifically, the sample is prepared by dry mixing the new material for polysiloxane boxes (product name: ME 8000) and recycled high-density polyethylene in a ratio of 9:1. Here, 9:1 refers to the weight ratio. Subsequently, after the sample is placed in the gel counter, the number of foreign matters with a size of 100 μm or more and less than 300 μm, the number of foreign matters with a size of 300 μm or more and less than 500 μm, and the number of foreign matters with a size of 500 μm or more are determined using the gel counter, and the numerical value obtained by multiplying the number of each area by 0.03, 0.05 and 0.1 is scored as the foreign matter score. In this specification, the lower the foreign matter score, the better the quality of the recycled high-density polyethylene.

[0068] In an exemplary embodiment of the present invention, the foreign matter fraction of the recycled high-density polyethylene may be less than 200, less than 150, or less than 100. When the foreign matter fraction is 200 or more, foreign matter is excessively present in the recycled high-density polyethylene, and thus the corresponding high-density polyethylene cannot be used as a recycled product. In addition, when the foreign matter fraction of the recycled high-density polyethylene is less than 200, problems in the extrusion process due to foreign matter do not occur, and when used as a PCR (post-consumer recycled) box product, the deterioration of the physical properties of the finished product can be prevented, and the thermal stability and external color characteristics can be improved.

[0069] In an exemplary embodiment of the present invention, the recycled high density polyethylene (HDPE) has an Izod impact strength of 2.5 to 8 kg·cm / cm, preferably 2.5 to 7 kg·cm / cm. The Izod impact strength may be measured according to ASTM D 256.

[0070] In an exemplary embodiment of the present invention, the recycled high density polyethylene (HDPE) may have an environmental stress crack resistance (ESCR) of 0.6 to 5 hours, preferably 1.0 to 3.5 hours. ESCR may be measured by a method according to ASTM D 1693.

[0071] In an exemplary embodiment of the present invention, the recycled high-density polyethylene may be derived from waste polysiloxane cartridges. Therefore, the recycled high-density polyethylene may be high-density polyethylene recycled according to the above-mentioned method for regenerating waste polysiloxane cartridges.

[0072] Hereinafter, embodiment will be described in detail to specifically illustrate the present invention. However, embodiments according to the present invention may be modified in other forms, and the scope of the present invention should not be construed as being limited to the following embodiments. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

[0073] Example 1

[0074] Waste silicone cartridges are recovered from construction sites, etc. After the silicone component of the recovered waste silicone cartridges is solidified, the waste silicone cartridges are pulverized into fragments having a size of 20 mm or less.

[0075] Figure 2 The waste silicone box is shown before and after being shredded. Figure 2 As shown, the recycled waste silicone boxes can be crushed into pieces with a size of less than 20 mm.

[0076] The crushed waste polysiloxane box is fed into the driver of the surface friction processing device at a speed of 900 kg / hr. The surface friction processing device includes a motor for rotating the driver. Then, the driver is rotated while the waste polysiloxane box is in contact with the driver, and the surface friction processing is performed.

[0077] After the surface friction process is completed, the waste silicone box is put into water.

[0078] At this time, the amount of energy applied to the waste silicone box from the time the waste silicone box was placed in the actuator of the surface friction processing device until the surface friction processing was completed was 42.4 J / kg.

[0079] After the waste polysiloxane box that has been subjected to surface friction processing is put into water, the high-density polyethylene (HDPE) floating on the water is recovered, and the polysiloxane sealant that has sunk under the water is recovered and discarded. In other words, the high-density polyethylene (HDPE) and the polysiloxane sealant in the waste polysiloxane box are separated by wet specific gravity separation.

[0080] The recycled high density polyethylene (HDPE) was then measured for foreign matter score, Izod impact strength and ESCR.

[0081] At this time, as described above, for the foreign matter score, after preparing a sample by dry-blending the new material for silicone boxes (product name: ME8000) and recycled high-density polyethylene in a ratio of 9:1, the number of foreign matter with a size of 100 μm or more and less than 300 μm, the number of foreign matter with a size of 300 μm or more and less than 500 μm, and the number of foreign matter with a size of 500 μm or more are determined using a gel counter, and the numerical value obtained by multiplying the number of each area by 0.03, 0.05 and 0.1 is scored as the foreign matter score.

[0082] In addition, the Izod impact strength and ESCR were measured by methods according to ASTM D 256 and ASTM D 1693, respectively.

[0083] The results are shown in Table 1 below.

[0084] Comparative Example 1

[0085] The waste silicone cartridge was pulverized in the same manner as in Example 1.

[0086] Next, unlike Example 1, the surface friction process was not performed, and the pulverized waste silicone box was put into water, and high-density polyethylene (HDPE) was recovered in the same manner as in Example 1.

[0087] Next, in the same manner as in Example 1, the foreign matter score, Izod impact strength, and ESCR of the recovered high-density polyethylene (HDPE) of Comparative Example 1 were measured.

[0088] Examples 2 to 10 and Comparative Examples 2 to 6

[0089] High-density polyethylene (HDPE) was recovered in the same manner as in Example 1 except that the amount of energy applied to the waste polysiloxane box in Example 1 was changed as shown in Table 1 (Examples 2 to 10 and Comparative Examples 2 to 6).

[0090] For Examples 2 to 10 and Comparative Examples 2 to 6, the foreign matter score, Izod impact strength and ESCR of the recycled high density polyethylene (HDPE) of Examples 2 to 10 and Comparative Examples 2 to 6 were measured in the same manner as in Example 1, and the results are shown in Table 1 below.

[0091] Table 1

[0092]

[0093] In Table 1, energy refers to the total amount of energy applied to the waste silicone box during the surface friction processing step.

[0094] Comparing the results of Comparative Example 1 with other Examples and Comparative Examples, it can be confirmed that the quality of the recovered high-density polyethylene (HDPE) is excellent when the surface friction processing step is performed. In Comparative Example 6, the quality of the recovered high-density polyethylene (HDPE) could not be measured.

[0095] In addition, it can be confirmed from the results of Comparative Examples 2 to 6 and Examples 1 to 10 that the method for regenerating waste polysiloxane boxes according to the present invention applies a certain amount of energy per unit weight to the waste polysiloxane boxes in the surface friction processing step, resulting in excellent foreign matter score, impact strength and ESCR (environmental stress crack resistance) of the recycled high-density polyethylene (HDPE).

[0096] This is considered to be because the surface friction processing is most efficiently performed when the above energy range is satisfied.

[0097] in addition, Figure 3 The correlation between the total energy applied to the waste polysiloxane box and the foreign matter fraction of the recycled high-density polyethylene in the examples and comparative examples is shown. Figure 3 As shown in the results of , it was confirmed that the foreign matter score can be minimized when the total amount of energy applied to the waste silicone box in the step of performing the surface friction processing is 35 J / kg to 100 J / kg.

[0098] in addition, Figure 4 The correlation between the foreign matter score and the impact strength of the high-density polyethylene recovered in the examples and comparative examples is shown. Figure 5 The correlation between the foreign matter fraction and ESCR of the high-density polyethylene recovered in the examples and comparative examples is shown. Figure 4 and Figure 5 As shown in the results, it can be confirmed that when the foreign matter fraction of the recycled high-density polyethylene is low, the impact strength and ESCR characteristics are excellent.

Claims

1. A method for regenerating a waste polysiloxane cartridge, the method comprising: shredding waste silicone boxes containing high density polyethylene (HDPE) and silicone sealant; performing surface friction processing on the waste polysiloxane box; and recovering high density polyethylene (HDPE) from the waste polysiloxane cartridges, The surface friction processing includes placing the crushed waste polysiloxane box into a driver, and generating friction on the surface of the waste polysiloxane box through the driver.

2. The method according to claim 1, wherein: The waste silicone boxes have been used as packaging containers for silicone sealants for construction or industrial purposes.

3. The method according to claim 1, wherein: The total amount of energy applied to the waste silicone box during the surface friction process is 35 J / kg to 100 J / kg.

4. The method according to claim 1, wherein: The step of using the actuator to generate friction on the surface of the waste silicone box includes: contacting the actuator with a surface of the waste silicone cartridge; and The actuator is rotated in a state where the actuator is in contact with a surface of the waste silicone box.

5. The method according to claim 1, wherein: In the step of placing the shredded waste polysiloxane box into the driver, the shredded waste polysiloxane box is placed into the driver at a rate of 500 kg / hr to 1500 kg / hr.

6. The method according to claim 1, wherein: The steps of recovering high density polyethylene from the waste polysiloxane cartridges include: placing the waste polysiloxane box into water, and separating the waste polysiloxane box into high-density polyethylene and polysiloxane sealant according to specific gravity; recovering the high density polyethylene; and The high density polyethylene is dried.

7. The method according to claim 6, wherein: When the high-density polyethylene is dried, the high-density polyethylene is dried at a temperature of 70°C to 90°C.

8. The method according to claim 1, wherein: In the step of pulverizing the waste silicone box containing high-density polyethylene and silicone sealant, the waste silicone box is pulverized into pieces having a size of 20 mm or less.

9. The method according to claim 1, further comprising: Before the waste silicone box containing high density polyethylene and silicone sealant is shredded, the silicone sealant of the waste silicone box is cured.

10. The method of claim 1, further comprising extruding the recovered high density polyethylene.

11. The method according to claim 10, wherein: When the recycled high-density polyethylene is extruded, the high-density polyethylene is extruded at a temperature of 190°C to 220°C.

12. A recycled high-density polyethylene, which satisfies Formula 1: [Formula 1] X=(A×0.03)+(B×0.05)+(C×0.1)<200 In the above formula 1, X is the foreign matter score of the recycled high-density polyethylene, A is the number of foreign matter with a size of 100 μm or more and less than 300 μm in the recycled high-density polyethylene, B is the number of foreign matters with a size of 300 μm or more and less than 500 μm in the recycled high-density polyethylene, and C is the number of foreign matters having a size of 500 μm or more in the recycled high-density polyethylene.

13. The recycled high-density polyethylene according to claim 12, wherein: The recycled high-density polyethylene has an Izod impact strength of 2.5 kg·cm / cm to 8 kg·cm / cm.

14. The recycled high-density polyethylene according to claim 12, wherein: The recycled high-density polyethylene has an environmental stress crack resistance (ESCR) of 0.6 hours to 5 hours.

15. The recycled high-density polyethylene according to claim 12, wherein: The recycled high density polyethylene is derived from waste silicone cartridges.

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