Decrosslinked polyolefin resin, composition containing same and method for preparing same

Abstract

Disclosed in the present invention is a decrosslinked polyolefin resin having a Tan(δ) value at 0.1 rad / s, of 0.75 or greater, defined by equation 1, and a TVOCs concentration of 90 ppm or less. [Equation 1] Tan(δ) = G'' / G' (In equation 1, G'' is a loss modulus of the decrosslinked polyolefin resin at 0.1 rad / s, and G' is a storage modulus of the decrosslinked polyolefin resin at 0.1 rad / s.) The present invention can have a low gel fraction, reduced odor, and excellent decrosslinking properties.

Description

Decrosslinked polyolefin resin, composition containing the same, and method for manufacturing the same

[0001] The present invention relates to a decrosslinked polyolefin resin, a resin composition containing the same, and a method for manufacturing the same. More specifically, the present invention relates to a decrosslinked polyolefin resin obtained by recycling a crosslinked polyolefin resin, which has a low gel fraction, reduced odor, and excellent decrosslinkability, a composition containing the same, and a method for manufacturing the same.

[0002] Cross-linked polyolefin resins are used in applications such as power cables due to their excellent insulation properties and thermal and chemical resistance. Although various plastic recycling methods are currently being researched for resource conservation, most cross-linked polyolefin resins are not currently being effectively recycled. To address this, a method is required to de-crosslink the polyolefin by removing its cross-linking structure.

[0003] Conventional decrosslinked polyolefin resins undergo decrosslinking at high extruder temperatures to maintain a low gel fraction. However, during this process, various byproducts are generated, resulting in high concentrations of TVOCs (Total Volatile Organic Compounds) and strong odors. Additionally, if the processing temperature is lowered to reduce byproduct generation, there are problems such as a high gel fraction and insufficient decrosslinking reaction.

[0004] Therefore, it is necessary to develop a decrosslinked polyolefin resin having a low gel fraction and reduced odor, a resin composition containing the same, and a method for manufacturing the same.

[0005] Related prior art is Korean Patent Publication No. 10-2642395.

[0006] The objective of the present invention is to provide a decrosslinked polyolefin resin having a Tan(δ) value of 0.75 or higher, a low gel fraction, and reduced odor, a composition including the same, and a method for manufacturing the same.

[0007] Another objective of the present invention is to provide a decrosslinked polyolefin resin with excellent decrosslinkability, a composition containing the same, and a method for manufacturing the same.

[0008] The above and other objectives of the present invention can all be achieved by the present invention described below.

[0009] 1. One aspect of the present invention relates to a decrosslinked polyolefin resin. The decrosslinked polyolefin resin has a Tan(δ) value of 0.75 or higher at 0.1 rad / s defined by Formula 1 below, and a TVOC concentration of 90 ppm or lower:

[0010] [Equation 1]

[0011] Tan(δ) = G'' / G'

[0012] (In Equation 1, G'' is the loss modulus of the decrosslinked polyolefin resin at 0.1 rad / s, and G' is the storage modulus of the decrosslinked polyolefin resin at 0.1 rad / s).

[0013] 2. In the above 1 embodiment, the decrosslinked polyolefin resin may be 10% by weight or less.

[0014] 3. In the above 1 to 2 embodiments, the decrosslinked polyolefin resin may have a decrosslinking quality index (DQI) defined by Formula 2 below of 250 or less:

[0015] [Equation 2]

[0016] DQI = C0.5 * Vt

[0017] (In Equation 2, C is the gel fraction (wt%), and Vt is the concentration of TVOCs (total volatile organic compounds) (ppm).

[0018] 4. In the above 1 to 3 embodiments, the decrosslinked polyolefin resin may be a polyolefin resin crosslinked by peroxide, a polyolefin resin crosslinked by electron beam, or a decrosslinked body of a silane crosslinked polyolefin resin.

[0019] 5. In the above 1 to 4 embodiments, the decrosslinked polyethylene resin may satisfy Formula 3 below:

[0020] [Equation 3]

[0021] 65 ≤ G0' / G' ≤ 5000

[0022] (In Equation 3, G0' is the storage modulus of the cross-linked polyolefin resin at 0.1 rad / s, and G' is the storage modulus of the decross-linked polyolefin resin at 0.1 rad / s).

[0023] 6. In the above 1 to 5 embodiments, the decrosslinked polyolefin resin may satisfy the following Formula 4:

[0024] [Equation 4]

[0025] 55 ≤ V0 / V ≤ 2000

[0026] (In Equation 4, V0 is the complex viscosity of the cross-linked polyolefin resin at 0.1 rad / s, and V is the complex viscosity of the decross-linked polyolefin resin at 0.1 rad / s).

[0027] 7. In the above 1 to 6 embodiments, the decrosslinked polyolefin resin may be a crosslinked polyolefin resin biscuited in the presence of a subcritical fluid or a supercritical fluid.

[0028] 8. Another aspect of the present invention relates to a composition. The composition comprises the decrosslinked polyolefin resin of embodiments 1 to 8.

[0029] 9. In the above 8 embodiments, the resin composition may further include a cross-linked polyolefin resin.

[0030] 10. Another aspect of the present invention relates to a method for producing a decrosslinked polyolefin resin. The method comprises the step of biscuiting a crosslinked polyolefin resin such that at 0.1 rad / s defined by Formula 1 below, the Tan(δ) value is 0.75 or higher and the TVOCs concentration is 90 ppm or lower:

[0031] [Equation 1]

[0032] Tan(δ) = G'' / G'

[0033] (In Equation 1, G'' is the loss modulus of the decrosslinked polyolefin resin at 0.1 rad / s, and G' is the storage modulus of the decrosslinked polyolefin resin at 0.1 rad / s).

[0034] 11. In the above 10 embodiments, the twin-screw extrusion can be performed at a temperature of 220 ℃ to 350 ℃.

[0035] 12. In the above 10 embodiments, the twin-screw extrusion can be performed at a temperature of 220°C to 350°C in the presence of a subcritical fluid or a supercritical fluid.

[0036] 13. In the above 10 to 12 embodiments, the subcritical fluid or supercritical fluid may be selected from one or more of carbon dioxide, alcohol, acetone, and water.

[0037] 14. In the above 10 to 13 embodiments, the gel fraction of the decrosslinked polyolefin resin may be 10% by weight or less.

[0038] 15. In the above 10 to 14 embodiments, the decrosslinked polyolefin resin may have a decrosslinking quality index (DQI) defined by Formula 2 below of 250 or less:

[0039] [Equation 2]

[0040] DQI = C0.5 * Vt

[0041] (In Equation 2, C is the gel fraction (wt%), and Vt is the concentration of TVOCs (total volatile organic compounds) (ppm).

[0042] 16. In the above 10 to 15 embodiments, the cross-linked polyolefin resin may include a polyolefin resin cross-linked by peroxide, a polyolefin resin cross-linked by electron beam, or a silane cross-linked polyolefin resin.

[0043] The present invention has the effect of providing a decrosslinked polyolefin resin having a Tan(δ) value of 0.75 or higher, a low gel fraction, reduced odor, and excellent decrosslinkability, a composition including the same, and a method for manufacturing the same.

[0044] Figure 1 compares the complex viscosity according to frequency of Example 1, Comparative Example 1, and Comparative Example 2.

[0045] Figure 2 compares the storage modulus (G') and loss modulus (G'') according to frequency of Example 1, Comparative Example 1, and Comparative Example 2.

[0046] The present invention will be described in more detail below. Where terms such as 'comprising,' 'having,' and 'consisting of' are used in this specification, other parts may be added unless 'only' is used. Where a component is expressed in the singular, it includes cases where it includes the plural unless specifically stated otherwise.

[0047] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0048] In this specification, 'TVOCs (Total Volatile Organic Compounds)' refers to volatile organic compounds having 6 to 16 carbon atoms.

[0049]

[0050] Hereinafter, a decrosslinked polyolefin resin according to an embodiment of the present invention, a resin composition including the same, and a method for manufacturing the same will be described in detail with reference to the drawings.

[0051]

[0052] One aspect of the present invention relates to a decrosslinked polyolefin resin.

[0053] Generally, crosslinking refers to the bonding of one polymer chain to another, in which monomers are repeatedly connected, while de-crosslinking refers to the process of removing or weakening crosslinking bonds.

[0054] The decrosslinked polyolefin resin according to the present invention can be prepared by a decrosslinking reaction of a crosslinked polyolefin resin. The decrosslinking reaction can be performed to control the physical properties of the polymer or to improve recyclability.

[0055] The above polyolefin resin may include olefin-based homopolymers such as polyethylene and polypropylene, or olefin-based random or block copolymers formed from polymers of two or more olefin monomers. The above polyethylene may be ultra-low density polyethylene (ULDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), or a combination thereof. However, it is not limited to the types of polyethylene described above.

[0056] The above decrosslinked polyolefin resin has a Tan(δ) value of approximately 0.75 or higher at 0.1 rad / s as defined by Formula 1 below:

[0057] [Equation 1]

[0058] Tan(δ) = G'' / G'

[0059] (In Equation 1, G'' is the loss modulus of the decrosslinked polyolefin resin at 0.1 rad / s, and G' is the storage modulus of the decrosslinked polyolefin resin at 0.1 rad / s).

[0060] In a specific example, the Tan(δ) value of the decrosslinked polyolefin resin at 0.1 rad / s may be about 0.79 or higher, for example, about 1 to 8, preferably about 2 to 5. When the Tan(δ) value of the decrosslinked polyolefin resin at 0.1 rad / s is about 0.75 or higher, it has excellent decrosslinkability and can secure properties close to those of the polyolefin before crosslinking, thereby having excellent recyclability.

[0061] In addition, the above-mentioned decrosslinked polyolefin resin has a TVOC concentration of about 90 ppm or less. When decrosslinking a crosslinked polyolefin resin is carried out at a high extruder temperature, various by-products are generated, resulting in a high concentration of TVOCs (Total Volatile Organic Compounds). Among volatile organic compounds, particularly C6 to C16 compounds, such as hexane, benzene, toluene, styrene, xylene, naphthalene, decane, and dodecane, have a problem of having a strong, irritating odor. The present invention is characterized by a decrosslinked polyolefin in which the by-products generated during decrosslinking are reduced, the TVOC concentration is significantly reduced, and the odor is reduced.

[0062] In a specific example, the concentration of TVOCs in the decrosslinked polyolefin resin may be about 60 ppm or less, for example, about 30 ppm or less, preferably about 10 ppm or less, more preferably about 3 ppm to 5 ppm. The lower the concentration of TVOCs, the more the odor may be reduced.

[0063] The above decrosslinked polyolefin resin may have a gel fraction of about 10% by weight or less. In a specific example, the gel fraction may be about 8.5% by weight or less, for example about 5% by weight or less, preferably about 1% by weight or less, most preferably about 0.001 to 0.5% by weight.

[0064] The above decrosslinked polyolefin resin may have a decrosslinking quality index (DQI) defined by Formula 2 below of about 250 or less:

[0065] [Equation 2]

[0066] DQI = C0.5 * Vt

[0067] (In Equation 2, C is the gel fraction (wt%), and Vt is the concentration of TVOCs (total volatile organic compounds) (ppm).

[0068] In a specific example, the decrosslinking quality index (DQI) may be about 190 or less, for example, about 100 or less, preferably about 35 or less, and more preferably about 5 to 15. Within this range, not only is off-flavor reduction achieved, but excellent decrosslinkability can also be secured simultaneously.

[0069] The above-mentioned decrosslinked polyolefin resin may be a polyolefin resin crosslinked by peroxide, a polyolefin resin crosslinked by electron beam, or a decrosslinked product of a silane-crosslinked polyolefin resin, and preferably may be a decrosslinked product of a polyolefin resin crosslinked by peroxide. However, it is not limited to the crosslinked polyolefin resins described above.

[0070] The above decrosslinked polyolefin resin can satisfy Formula 3 below:

[0071] [Equation 3]

[0072] 65 ≤ G0' / G' ≤ 5000

[0073] (In Equation 3, G0' is the storage modulus of the cross-linked polyolefin resin at 0.1 rad / s, and G' is the storage modulus of the decross-linked polyolefin resin at 0.1 rad / s).

[0074] In a specific example, the above G0' / G may be 80 to 3500, for example, about 100 to 2000, preferably about 200 to 1500, more preferably about 400 to 1000. In the above range, decrosslinkability is excellent.

[0075] The above decrosslinked polyolefin resin can satisfy Formula 4 below.

[0076] [Equation 4]

[0077] 55 ≤ V0 / V ≤ 2000

[0078] (In Equation 4, V0 is the complex viscosity of the cross-linked polyolefin resin at 0.1 rad / s, and V is the complex viscosity of the decross-linked polyolefin resin at 0.1 rad / s).

[0079] In a specific example, the above V0 / V may be about 70 to 1900, for example, about 100 to 1800, preferably about 150 to 1700. In the above range, decrosslinkability is excellent.

[0080] The above-mentioned decrosslinked polyolefin resin can be biscuited from a crosslinked polyolefin resin in the presence of a subcritical or supercritical fluid. The supercritical fluid has excellent solute penetration and reactivity, allowing it to penetrate into the polymer resin with a large free volume and uniformly transfer thermal energy. Through this, recycled resin of uniform quality can be produced during the decrosslinking process of crosslinked products. Furthermore, when using the subcritical fluid, temperature and pressure can be easily controlled, making reuse after decrosslinking easier.

[0081] The above fluid may be a carbon-10 alcohol, acetone, water, an organic solvent, carbon dioxide, etc. The above alcohol may be a monohydric, dihydric, or polyhydric alcohol. In specific examples, methanol, ethanol, etc. may be used. However, it is not limited to the fluids described above. The pressure of the above fluid may be about 10 bar to 80 bar, about 15 bar to 75 bar in specific examples, for example, about 20 bar to 70 bar. Excellent decrosslinkability can be secured within the above range.

[0082] In addition, the above fluid may be introduced in an amount of about 0.1 wt% to 20 wt%, in a specific example about 1 wt% to 15 wt%, for example about 3 wt% to 9 wt%. In the above range, not only can excellent decrosslinkability be secured, but a low gel fraction is also obtained. Furthermore, in the above range, by-products generated during decrosslinking are reduced, so the concentration of TVOCs is significantly reduced and odor can be reduced.

[0083]

[0084] Another aspect of the present invention relates to a composition comprising the above-described decrosslinked polyolefin resin.

[0085] The above composition may include a cross-linked polyolefin resin. When a mixture of decross-linked polyolefin and cross-linked polyolefin is applied in this manner, mechanical properties that may be low when using only decross-linked polyolefin resin can be reinforced, and additionally, resin color and odor can be diluted.

[0086] The above composition can be applied by mixing a cross-linked polyolefin resin in an amount of about 0.01 to 80 parts by weight with 100 parts by weight of a decross-linked polyolefin resin. In a specific example, it may be about 1 to 70 parts by weight, for example, about 10 to 60 parts by weight. Within the above range, it has excellent decrosslinkability, and the by-products generated during decrosslinking are reduced, so the odor can be reduced.

[0087]

[0088] Another aspect of the present invention relates to a method for manufacturing a decrosslinked polyolefin resin. The method comprises the step of biscuiting a crosslinked polyolefin resin such that at 0.1 rad / s defined by Formula 1, the Tan(δ) value is about 0.75 or higher and the TVOCs concentration is about 90 ppm or lower.

[0089] The above-described twin-screw extrusion can be performed in the presence of a subcritical fluid or a supercritical fluid at a temperature of about 220°C to 350°C. The subcritical fluid or supercritical fluid is as described above and is therefore omitted below. In addition, in a specific example, the temperature may be about 230°C to 330°C, preferably about 250°C to 330°C. In this range, not only can excellent decrosslinkability be secured, but a low gel fraction is also obtained. Furthermore, in this range, by-products generated during decrosslinking are reduced, so the concentration of TVOCs is significantly reduced and odor can be reduced. The subcritical fluid or supercritical fluid may be selected from one or more of carbon dioxide, alcohol, acetone, and water. In a specific example, alcohols having 1 to 4 carbon atoms, organic solvents, carbon dioxide, etc. may be used. For example, it may be methanol, ethanol, 1-propanol, and 2-propanol, etc. However, it is not limited to fluids as described above.

[0090] The above-mentioned cross-linked polyolefin resin may include a polyolefin resin cross-linked by peroxide, a polyolefin resin cross-linked by electron beam, or a silane cross-linked polyolefin resin, and preferably may be a polyolefin resin cross-linked by peroxide. However, it is not limited to the cross-linked polyolefin resins described above.

[0091]

[0092] The present invention is to be explained more specifically below through examples and comparative examples; however, these examples are for illustrative purposes only and should not be interpreted as limiting the invention.

[0093]

[0094] Examples

[0095] Each component used in the following examples and comparative examples is as follows:

[0096] (a1) XLPE: Cross-linked polyethylene resin (XLPE wire waste) with a density (ASTM D1505) of 0.919 g / cm3 and a gel fraction of 48.5% was used.

[0097] (a2) XLPE: A cross-linked polyethylene resin (HD cross-linked pipe) with a density (ASTM D1505) of 0.932 g / cm3 and a gel fraction of 80.5% was used.

[0098] (a3) XLPE: Cross-linked polyethylene resin (XLPE pipe waste) with a density (ASTM D1505) of 0.918 g / cm3 and a gel fraction of 90.5% was used.

[0099]

[0100] Example 1

[0101] Decrosslinked polyethylene resin was prepared by decrosslinking XLPE (a1) using a twin-screw extruder (SM Platek, 30mm Screw) at 330℃ and a die temperature of 250℃ to achieve a TVOC concentration of 15 ppm.

[0102]

[0103] Example 2

[0104] The above example was performed in the same manner as Example 1, except that XLPE (a1) was decrosslinked by injecting 4 wt% of supercritical ethanol (b) at a die temperature of 300 ℃ and 250 ℃ so that the TVOCs concentration was 10 ppm.

[0105]

[0106] Example 3

[0107] The procedure was performed in the same manner as Example 1, except that XLPE (a2) was used instead of XLPE (a1) to perform decrosslinking extrusion so that the TVOCs concentration was 13 ppm.

[0108]

[0109] Example 4

[0110] The procedure was carried out in the same manner as Example 3 above, except that 4 wt% of supercritical ethanol (b) was injected to make the TVOC concentration 3 ppm and decrosslinking extrusion was performed.

[0111]

[0112] Example 5

[0113] The procedure was performed in the same manner as Example 1, except that XLPE (a3) ​​was used instead of XLPE (a1), and decrosslinking extrusion was carried out by injecting 4 wt% of supercritical CO2 (c) to achieve a TVOC concentration of 8 ppm.

[0114]

[0115] Example 6

[0116] The procedure was carried out in the same manner as Example 5 above, except that 4 wt% of supercritical ethanol (b) was injected instead of supercritical CO2 (c) to achieve a TVOC concentration of 6 ppm.

[0117]

[0118] Comparative Example 1

[0119] XLPE (a1) that was not subjected to decrosslinking extrusion was used.

[0120]

[0121] Comparative Example 2

[0122] The procedure was carried out in the same manner as Example 1 above, except that decrosslinking extrusion was performed at 260 ℃ to achieve a TVOC concentration of 7 ppm.

[0123]

[0124] Comparative Example 3

[0125] XLPE (a2) that was not subjected to decrosslinking extrusion was used.

[0126]

[0127] Comparative Example 4

[0128] XLPE (a3) ​​that was not subjected to decrosslinking extrusion was used.

[0129]

[0130] Comparative Example 5

[0131] The procedure was performed in the same manner as Example 1 above, except that decrosslinking extrusion was carried out using a uniaxial extruder at 400 ℃ to achieve a TVOC concentration of 94 ppm.

[0132]

[0133] The physical properties of the above examples and comparative examples were evaluated by the following method, and the results are shown in Table 1:

[0134]

[0135] Methods for evaluating physical properties

[0136] (1) Gel fraction (wt%)

[0137] Gel fraction was analyzed using Xylene according to ASTM D2765. In this case, 120-mesh stainless steel was used, and the gel content was measured by extracting in Xylene at a temperature of 140°C or higher and drying, and the gel fraction was defined as the percentage of the weight of the insoluble matter relative to the weight of the raw sample.

[0138]

[0139] (2) Tan(δ) (loss factor)

[0140] ​A frequency sweep test of the sample was conducted using a rheological property measuring instrument (Modular Compact Rheometer 301 (MCR 301, Anton Paar)) at a temperature of 190 ℃, a shear strain of 1%, and a frequency of 0.1 rad / s to 500 rad / s.

[0141] The above sample was manufactured in the form of a sheet with a diameter of 25 mm and a thickness of 1 mm using a hot press.

[0142] At this time, the storage modulus (G') and loss modulus (G'') of the sample were measured at a temperature of 190 ℃ and a frequency of 0.1 rad / s, and Tan(δ) was calculated using G'' / G' according to Equation 1 below:

[0143] [Equation 1]

[0144] Tan(δ) = G'' / G'

[0145] (In Equation 1, G'' is the loss modulus of the decrosslinked polyolefin resin at 0.1 rad / s, and G' is the storage modulus of the decrosslinked polyolefin resin at 0.1 rad / s).

[0146]

[0147] In addition, the storage modulus before and after decrosslinking at 0.1 rad / s was measured, and the ratio of the storage modulus (G0' / G') was calculated. G0' is the storage modulus of the crosslinked polyolefin resin at 0.1 rad / s, and G' is the storage modulus of the decrosslinked polyolefin resin at 0.1 rad / s.

[0148]

[0149] (3) Concentration of TVOCs (ppm)

[0150] The concentration of TVOCs in the sample was measured using HSS (PerkinElmer) and GC (Agilent) instruments.

[0151] The above sample was used by heating the sample at 150°C for 30 minutes using HSS equipment and concentrating the volatile gas components within the Headspace released into the adsorption tube using a cold trap.

[0152]

[0153] (4) Decrosslinking Quality Index (DQI)

[0154] After obtaining Tan(δ) from Equation 1, it was calculated using Equation 2 below:

[0155] [Equation 2]

[0156] DQI = C0.5 * Vt

[0157] (In Equation 2, C is the gel fraction (wt%), and Vt is the concentration of TVOCs (total volatile organic compounds) (ppm).

[0158]

[0159] (5) Complex viscosity (Pa s)

[0160] A frequency sweep test of the sample was conducted using a Modular Compact Rheometer 301 (MCR 301, Anton Paar) at a temperature of 190 ℃, a shear strain of 1%, and a frequency of 0.1 rad / s to 500 rad / s.

[0161] At this time, the complex viscosity before and after decrosslinking was measured and the ratio of complex viscosities (V0 / V) was calculated. V0 is the complex viscosity of the crosslinked polyolefin resin at 0.1 rad / s, and V is the complex viscosity of the decrosslinked polyolefin resin at 0.1 rad / s.

[0162]

[0163] Gel fraction (wt%) Tan(δ) Concentration of TVOCs (ppm) Balance index (BI) G0' / G' V0 / V Example 1 1.0 1.0 2 15 15 10 876 Example 2 2 3.0 9 10 28.8 89 70 Example 3 3.0 3.5 7 13 7.1 53 50 97 55 Example 4 4.0 2.1 23 1.8 9 43 51 87 Example 5 5.0 6 1.4 38 6.1 62 21 127 Example 6 6.0 6 5.3 4 10 168 Comparative Example 1 > 50 0.1 55 74 03 11 Comparative Example 2 15 0.6 87 27.1 63 53 Comparative Example 3 > 80 0.1 21 32 11 80 11 Comparative Example 4>900.05269255011Comparative Example 50.24.329441540,407123,289

[0164] As shown in Table 1 above, it can be confirmed that Examples 1-6 according to the present invention have a significantly low gel fraction, excellent decrosslinkability, and a low concentration of TVOCs. On the other hand, Comparative Examples 1, 3, and 4 showed higher gel fractions and TVOC concentrations and lower Tan(δ) values ​​compared to Examples 1-6, while Comparative Example 2 secured a low concentration of TVOCs but showed a high gel fraction and a low Tan(δ) value. Comparative Example 5 showed a low gel fraction and a high Tan(δ), but showed a high concentration of TVOCs.

[0165]

[0166] Figure 1 compares the complex viscosity of Example 1, Comparative Example 1, and Comparative Example 2 according to frequency. The complex viscosity was measured to evaluate flow characteristics such as the physical state, degree of crosslinking, and processability of the polymer. As shown in Figure 1, since Example 1 has a lower degree of crosslinking compared to Comparative Examples 1 and 2, it can be seen that the complex viscosity value is lower. In addition, when calculating the complex viscosity ratio (V0 / V) before and after decrosslinking, it was confirmed that Example 1 has a higher complex viscosity ratio compared to Comparative Example 2.

[0167]

[0168] Figure 2 compares the storage modulus (G') and loss modulus (G'') according to frequency of Example 1, Comparative Example 1, and Comparative Example 2. It is presumed that crosslinking proceeded when G' > G' at low frequencies such as 0.1 rad / s.

[0169] As shown in FIG. 2, it can be confirmed that Example 1 exhibits unique rheological behavior compared to Comparative Examples 1 and 2. Comparative Example 1, which has a high gel fraction, showed a Tan(δ) value of 0.15 at 0.1 rad / s. On the other hand, Example 1 produced a product with a Tan(δ) value of 1.02. In addition, Comparative Example 2 was found to have a Tan(δ) value of only 0.68.

[0170]

[0171] Simple variations or modifications of the present invention can be easily implemented by those skilled in the art, and all such variations or modifications are considered to be included within the scope of the present invention.

Claims

1. As a decrosslinked polyolefin resin, At 0.1 rad / s defined by Equation 1 below, the Tan(δ) value is 0.75 or greater, and Decrosslinked polyolefin resin having a TVOCs concentration of 90 ppm or less: [Equation 1] Tan(δ) = G'' / G' (In Equation 1, G'' is the loss modulus of the decrosslinked polyolefin resin at 0.1 rad / s, and G' is the storage modulus of the decrosslinked polyolefin resin at 0.1 rad / s).

2. In Paragraph 1, The above decrosslinked polyolefin resin is a decrosslinked polyolefin resin having a gel fraction of 10 weight% or less.

3. In Paragraph 1, The above decrosslinked polyolefin resin is a decrosslinked polyolefin resin having a decrosslinking quality index (DQI) defined by Formula 2 below of 250 or less: [Equation 2] DQI = C0.5 * Vt (In Equation 2, C is the gel fraction (wt%), and Vt is the concentration of TVOCs (total volatile organic compounds) (ppm).

4. In Paragraph 1, The above-mentioned decrosslinked polyolefin resin is a decrosslinked body of a polyolefin resin crosslinked by peroxide, a polyolefin resin crosslinked by electron beam, or a silane-crosslinked polyolefin resin.

5. In Paragraph 4, The above decrosslinked polyolefin resin is a decrosslinked polyolefin resin satisfying Formula 3 below: [Equation 3] 65 ≤ G0' / G' ≤ 5000 (In Equation 3, G0' is the storage modulus of the cross-linked polyolefin resin at 0.1 rad / s, and G' is the storage modulus of the decross-linked polyolefin resin at 0.1 rad / s).

6. In Paragraph 4, The above decrosslinked polyolefin resin is a decrosslinked polyolefin resin satisfying Formula 4 below: [Equation 4] 55 ≤ V0 / V ≤ 2000 (In Equation 4, V0 is the complex viscosity of the cross-linked polyolefin resin at 0.1 rad / s, and V is the complex viscosity of the decross-linked polyolefin resin at 0.1 rad / s) 7. In Paragraph 1, The above-mentioned decrosslinked polyolefin resin is a decrosslinked polyolefin resin that is biscuitly extruded from a crosslinked polyolefin resin in the presence of a subcritical fluid or a supercritical fluid.

8. A composition comprising a decrosslinked polyolefin resin according to any one of claims 1 to 7.

9. In Paragraph 8, The above composition is a composition further comprising a cross-linked polyolefin resin.

10. A method for manufacturing a decrosslinked polyolefin resin, comprising the step of biscuitly extruding a crosslinked polyolefin resin such that at 0.1 rad / s defined by Formula 1 below, the Tan(δ) value is 0.75 or higher and the TVOCs concentration is 90 ppm or lower: [Equation 1] Tan(δ) = G'' / G' (In Equation 1, G'' is the loss modulus of the decrosslinked polyolefin resin at 0.1 rad / s, and G' is the storage modulus of the decrosslinked polyolefin resin at 0.1 rad / s).

11. In Paragraph 10, A method for manufacturing a decrosslinked polyolefin resin, wherein the above-mentioned twin-screw extrusion is performed at a temperature of 220 ℃ to 350 ℃.

12. In Paragraph 10, A method for manufacturing a decrosslinked polyolefin resin, wherein the above-mentioned twin-screw extrusion is performed at a temperature of 220°C to 350°C in the presence of a subcritical fluid or a supercritical fluid.

13. In Paragraph 12, A method for manufacturing a decrosslinked polyolefin resin, wherein the above subcritical fluid or supercritical fluid is selected from one or more of carbon dioxide, alcohol, acetone, and water.

14. In Paragraph 10, A method for manufacturing a decrosslinked polyolefin resin, wherein the decrosslinked polyolefin resin has a gel fraction of 10 weight% or less.

15. In Paragraph 10, A method for manufacturing a decrosslinked polyolefin resin, wherein the above decrosslinked polyolefin resin has a decrosslinking quality index (DQI) defined by Formula 2 below of 250 or less: [Equation 2] DQI = C0.5 * Vt (In Equation 2, C is the gel fraction (wt%), and Vt is the concentration of TVOCs (total volatile organic compounds) (ppm).

16. In Paragraph 10, A method for manufacturing a decrosslinked polyolefin resin, wherein the crosslinked polyolefin resin comprises a polyolefin resin crosslinked by peroxide, a polyolefin resin crosslinked by electron beam, or a silane crosslinked polyolefin resin.

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