Poly(ethylene-vinyl acetate) vitrimer and method for manufacturing same

Abstract

The present invention relates to a novel polyethylene-vinyl acetate vitrimer. In an embodiment, the polyethylene-vinyl acetate vitrimer is manufactured from a composition comprising: a polyethylene-vinyl acetate copolymer; and a mixture of a first compound and a second compound, wherein the first and second compounds are represented by the following chemical formula 1 and chemical formula 2, respectively: [Chemical formula 1] M1(-O-L1-R1)n [Chemical formula 2] M2(-O-L2-R2)m (chemical formula 1 and chemical formula 2 are as described in the Detail Description). Unlike conventional crosslinked materials, the polyethylene-vinyl acetate vitrimer according to the present invention can be repeatedly recycled through a bond exchange reaction without a decomposition reaction such as pyrolysis, hydrolysis, and the like even when repeated thermoforming is performed,

Description

Polyethylene-vinyl acetate vitrifiers and their preparation methods

[0001] The present invention relates to a novel polyethylene-vinyl acetate vitrifier and a method for producing the same.

[0002]

[0003] Polyethylene-vinyl acetate copolymer (hereinafter referred to as EVA) is a polymer compound that is easy to process at low temperatures and is easy to crosslink. It has the advantages of low specific gravity, appropriate mechanical strength, and excellent impact-absorbing properties when crosslinked or crosslinked to form foam, and is widely used in industrial fields such as shoes and packaging materials, and its application range is gradually expanding.

[0004] However, with the recent environmental pollution caused by excessive plastic use becoming a major issue, discussions on recycling methods for plastics are actively underway. Crosslinked EVA and crosslinked foam products are no exception. Conventional crosslinked EVA and foam products are crosslinked and therefore cannot be reprocessed, making them unfriendly to the environment. They cannot be recycled and must be disposed of after use.

[0005] To address the above issues, research is being conducted on EVA vitrifiers. EVA vitrifiers are materials whose topology can be altered by thermally activated exchange reactions. At high temperatures, they flow like a viscoelastic liquid, but at low temperatures, bond exchange reactions proceed very slowly, resulting in a thermosetting behavior. Therefore, they are attracting significant attention as a potential alternative to conventional crosslinked EVA materials, offering the same properties as traditional EVA.

[0006] For example, Lin Chen ("Recyclable ethylene-vinyl acetate copolymer vitrimer foams." Polymer 222 (2021): 123662.) has developed an EVA vitrimer using boronic acid triethyl ester (BATEE), 2,2'-(1,4-Phenylene)-bis[4-methyl-1,3,2-dioxaborolane] (PBMDB), Triethyl phosphate (TEP), and / or dimethyl glutarate (DMG) as crosslinkers in EVA resin, and tetrabutyl titanate as a catalyst.

[0007] Also, EVA vitrifier prepared using triethyl borate as a cross-linking agent and bis(acetylacetonato)-dioxomolybdenum (VI) as a catalyst is known by Guo, Haochen ("Recycling poly (ethylene-vinyl acetate) with improved properties through dynamic cross-linking." Macromolecules 53.1 (2019): 458-464.).

[0008] In this way, the conventionally known EVA vitrifier has the limitation that a cross-linker and a catalyst must be used simultaneously, and the type of cross-linker used is limited, making it difficult to diversify the properties of the EVA vitrifier and use it for a wide range of purposes. Therefore, the development of a new EVA vitrifier is still required.

[0009]

[0010] The purpose of the present invention is to provide a new polyethylene-vinyl acetate vitrifier and a method for producing the same, which minimizes the deterioration of mechanical properties and is recyclable even when repeated thermal history is applied, such as through heat-induced esterification / de-esterification exchange reactions.

[0011] Another object of the present invention is to provide a molded product manufactured using the polyethylene-vinyl acetate vitrifier.

[0012] The present inventors have completed the present invention by developing a new polyethylene-vinyl acetate vitrifier that has similar physical properties to polyethylene-vinyl acetate crosslinked foams, but is capable of being thermoformed by repeated thermal processing, unlike conventional chemical crosslinked foams.

[0013]

[0014] 1. One aspect of the present invention relates to a polyethylene-vinylacetate vitrimer. In one embodiment, the present invention provides a polyethylene-vinylacetate vitrimer prepared from a composition comprising a polyethylene-vinylacetate copolymer; and a mixed compound containing a first compound and a second compound, wherein the first compound is represented by the following chemical formula 1, and the second compound is represented by the following chemical formula 2.

[0015] [Chemical Formula 1]

[0016] M1(-O-L1-R1) n

[0017] [Chemical Formula 2]

[0018] M2(-O-L2-R2) m

[0019] (In the above chemical formula 1, M1 and M2 are different metal elements, L1 and L2 are each independently a single bond, -C(=O)-, -O- and -OC(=O)-, and R1 and R2 are each independently hydrogen or C 1-30is a substituted or unsubstituted alkyl group, and n and m are each independently 1, 2, 3, or 4).

[0020] 2. In 1, the metal element may be any one selected from an alkali metal, an alkaline earth metal, a transition metal, and a post-transition metal.

[0021] 3. In 1-2, at least one of the first compound and the second compound may contain a transition metal or a post-transition metal as a central metal.

[0022] 4. In 1-3, at least one of the first compound and the second compound may contain titanium (Ti) or aluminum (Al) as a central metal.

[0023] 5. In 1-4, M1 and M2 may each independently be any one selected from lithium (Li), aluminum (Al), zinc (Zn), titanium (Ti), tin (Sn), or molybdenum (Mo).

[0024] 6. In 1-5, L1 and L2 are each independently a single bond or -C(=O)-, and R1 and R2 are each independently hydrogen or C 1-15 is an alkyl group, and n and m can each independently be 1, 2, 3, or 4.

[0025] 7. In 1-6, the mixed compound may be included in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the polyethylene-vinyl acetate copolymer.

[0026] 8. In 1-7, the first compound and the second compound may each be independently included in an amount of 5 wt% or more based on the total weight of the mixed compound.

[0027] 9. In 1-8, the polyethylene-vinyl acetate vitrifier may have a Tanδ(G" / G') of 1 or more at 200°C as a result of a temperature sweep test under an angular frequency condition of 0.1 rad / s or less and a shear strain condition of 1 to 30%.

[0028] 10. In 1-9, the polyethylene-vinyl acetate vitrimer may have a complex viscosity at 115°C higher than the complex viscosity of the polyethylene-vinyl acetate copolymer as a result of a temperature sweep test under an angular frequency condition of 0.1 to 5 rad / s and a shear strain condition of 1 to 30%.

[0029] 11. In 1-10, the elongation at break (E) measured according to ASTM D638 after reprocessing the polyethylene-vinyl acetate vitrifier at least once under temperature conditions of 150 to 200℃ r ) is the elongation at break (E) before reprocessing i ) may be higher.

[0030] 12. Another aspect of the present invention relates to a molded article manufactured from the polyethylene-vinyl acetate bitrimer.

[0031] 13. Another aspect of the present invention relates to a polyethylene-vinylacetate composition for producing the polyethylene-vinylacetate vitrimer. In one embodiment, the present invention provides a polyethylene-vinylacetate composition for producing a vitrimer, comprising: a polyethylene-vinylacetate copolymer; and a mixed compound containing a first compound and a second compound; wherein the first compound is represented by the following chemical formula 1, and the second compound is represented by the following chemical formula 2.

[0032] [Chemical Formula 1]

[0033] M1(-O-L1-R1) n

[0034] [Chemical Formula 2]

[0035] M2(-O-L2-R2) m

[0036] (In the above chemical formulas 1 and 2, M1 and M2 are different metal elements, L1 and L2 are each independently a single bond, -C(=O)-, -O- and -OC(=O)-, and R1 and R2 are each independently hydrogen or C 1-30 is a substituted or unsubstituted alkyl group, and n and m are each independently 1, 2, 3, or 4).

[0037] 14. In 13, the metal element may be any one selected from an alkali metal, an alkaline earth metal, a transition metal, and a post-transition metal.

[0038] 15. In 13-14, at least one of the first compound and the second compound may include a transition metal or a post-transition metal as a central metal.

[0039] 16. In 13-15, at least one of the first compound and the second compound may contain titanium (Ti) or aluminum (Al) as a central metal.

[0040] 17. In 13-16, M1 and M2 may each independently be any one selected from lithium (Li), aluminum (Al), zinc (Zn), titanium (Ti), tin (Sn), or molybdenum (Mo).

[0041] 18. In 13-17, L1 and L2 are each independently a single bond or -C(=O)-, and R1 and R2 are each independently hydrogen or C 1-15 is an alkyl group, and n and m can each independently be 1, 2, 3, or 4.

[0042]

[0043] According to one embodiment of the present invention, unlike conventional crosslinked products, the polyethylene-vinyl acetate vitrifier can be repeatedly recycled through a bond exchange reaction without decomposition reactions such as thermal decomposition or hydrolysis even when repeatedly thermoforming.

[0044] The novel polyethylene-vinyl acetate vitrifier of the present invention has a higher complex viscosity than conventional non-crosslinked EVA resins due to its crosslinking properties, and at the same time can implement mechanical properties equivalent to those of conventional chemically crosslinked EVA. Specifically, the vitrifier exhibits elasticity properties at low temperatures and behaves like a thermosetting resin similar to conventional cross-linked EVA, but at high temperatures, for example, around 100 to 220°C, a cross-point occurs where the elastic modulus (G") becomes lower than the viscous modulus (or loss modulus), and viscosity becomes dominant. Therefore, it exhibits properties similar to a thermosetting resin at low temperatures, but exhibits the flowable rheological properties of a thermoplastic resin at temperatures above the cross-point. Accordingly, the vitrifier exhibits rheological properties different from conventional chemically cross-linked EVA that cannot be thermally processed, and thus has the advantage of being recyclable because it can be repeatedly thermally processed at high temperatures.

[0045]

[0046] FIG. 1 is a graph showing the complex viscosity of polyethylene-vinyl acetate vitrifier, EVA, and chemically cross-linked EVA according to Examples 1 to 3 and Comparative Examples 1 to 4 as a function of temperature.

[0047] FIG. 2 is a graph showing the rheological properties (storage modulus (G') and loss modulus (G")) of polyethylene-vinyl acetate vitriol, EVA, and chemically cross-linked EVA according to Examples 1 to 3 and Comparative Examples 1 to 4 depending on the temperature.

[0048] Figure 3 is a graph showing the rheological properties (storage modulus (G') and loss modulus (G")) according to temperature after repeatedly thermoforming (0 times, 5 times) the polyethylene-vinyl acetate vitrifier according to Example 1.

[0049]

[0050] The present invention will be described in more detail below through specific examples or embodiments, including the attached drawings. However, the following specific examples or embodiments are merely references for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

[0051] Additionally, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is merely for the purpose of describing specific embodiments and is not intended to be limiting.

[0052] Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

[0053] The term "including" in this specification means that other components may be included rather than excluding other components unless specifically stated to the contrary.

[0054] In this specification, "substituted" means that a hydrogen atom of a substituted moiety is replaced by a substituent. The substituent may be used without limitation as long as it is a known substituent. Examples of the substituent include hydroxy, halogen, nitro, cyano, amino, carboxyl, carboxylate, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 alkynyl, C 1-20 Haloalkyl, C 1-20 Alkoxy, C 1-20 Alkoxycarbonyl, C 3-30 Cycloalkyl, (C 6-30 )Ar(C 1-20 )alkyl, C 6-30 Aryl and C 3-30 It may be one or more selected from heteroaryl, but is not limited thereto.

[0055] The term "combination of these" in this specification means a mixture or combination of one or more of the described components.

[0056] As used herein, the term "and / or" is meant to include any and all combinations of one or more of the items described herein. As used herein, the term "or" means "and / or." The expressions "at least one" or "one or more" preceding elements herein may modify the entire list of elements and do not mean that they modify individual elements described above.

[0057] As used herein, the singular forms may be intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0058] Unless otherwise specified, units used herein are based on weight, and for example, units of % or ratio refer to weight% or weight ratio, and weight% refers to the weight% that any one component in the entire composition occupies in the composition unless otherwise defined. That is, weight% (% by weight) refers to an absolute number as (weight of any one component in the composition / total weight of the composition) x 100.

[0059] In this specification, part by weight means a relative value calculated by converting the weight of one substance to 1 (standard) and calculating the weight of another substance based on that.

[0060] The numerical ranges used herein include lower and upper limits and all values ​​within those ranges, increments logically derived from the shape and width of the defined range, all doubly defined values, and all possible combinations of upper and lower limits of numerical ranges defined in different shapes. Unless otherwise specified in the specification of the present invention, values ​​outside the numerical range that may arise due to experimental error or rounding of values ​​are also included in the defined numerical range.

[0061] In this specification, rheological characteristics may refer to rheological characteristics. In addition, the rheological characteristics may be characteristics that are exhibited by the flow and deformation of a fluid as a viscoelastic material.

[0062] Hereinafter, the polyethylene-vinyl acetate vitrimer (hereinafter, EVA (ethylene-vinyl acetate) vitrimer) of the present invention and the polyethylene-vinyl acetate composition (hereinafter, EVA (ethylene-vinyl acetate) composition) for producing the same will be described in detail.

[0063] The present invention relates to a polyethylene-vinyl acetate vitrimer manufactured from a composition comprising a polyethylene-vinyl acetate copolymer (hereinafter, EVA (ethylene-vinyl acetate)); and a mixed compound containing a first compound and a second compound, wherein the first compound is represented by the following chemical formula 1, and the second compound is represented by the following chemical formula 2.

[0064] [Chemical Formula 1]

[0065] M1(-O-L1-R1) n

[0066] [Chemical Formula 2]

[0067] M2(-O-L2-R2) m

[0068] In the above chemical formulas 1 and 2,

[0069] M1 and M2 are different metal elements,

[0070] L1 and L2 are each independently a single bond, -C(=O)-, -O-, and -OC(=O)-,

[0071] R1 and R2 are each independently hydrogen or C 1-30 is a substituted or unsubstituted alkyl group,

[0072] n and m are each independently 1, 2, 3, or 4.

[0073] In addition, another example of the present invention can provide a polyethylene-vinylacetate composition for producing a vitrimer, which comprises a polyethylene-vinylacetate copolymer and a mixed compound containing a first compound and a second compound, wherein the first compound is represented by the following chemical formula 1, and the second compound is represented by the following chemical formula 2.

[0074] [Chemical Formula 1]

[0075] M1(-O-L1-R1) n

[0076] [Chemical Formula 2]

[0077] M2(-O-L2-R2) m

[0078] In the above chemical formulas 1 and 2,

[0079] M1 and M2 are different metal elements,

[0080] L1 and L2 are each independently a single bond, -C(=O)-, -O-, and -OC(=O)-,

[0081] R1 and R2 are each independently hydrogen or C 1-30 is a substituted or unsubstituted alkyl group,

[0082] n and m are each independently 1, 2, 3, or 4.

[0083]

[0084] Hereinafter, each component of the present invention will be described in detail.

[0085] First, a polyethylene-vinyl acetate copolymer (or EVA (ethylene-vinyl acetate) resin) will be described. The polyethylene-vinyl acetate copolymer of the present invention is a copolymer obtained using an ethylene monomer and a vinyl acetate monomer, and can be obtained by various polymerization methods such as bulk polymerization, solution or emulsion polymerization, and therefore the manufacturing method is not limited.

[0086] In a specific embodiment of the present invention, the polyethylene vinyl acetate copolymer may have a vinyl acetate unit content of 5 to 70 wt%. When included in the above range, the polyethylene-vinyl acetate vitrimer can be manufactured, and the final product using the manufactured polyethylene-vinyl acetate vitrimer may have excellent physical properties such as elasticity. For example, the polyethylene vinyl acetate copolymer may have a vinyl acetate unit content of 10 to 60 wt%, 20 to 50 wt%, or 15 to 45 wt%.

[0087] In a specific embodiment of the present invention, the polyethylene vinyl acetate copolymer may have a melt index (MI) of 100 g / 10 min or less under measurement conditions of 190°C and 2.16 kg. When included within the above range, the processability and mechanical properties of the polyethylene-vinyl acetate vitrifier may be excellent. For example, the polyethylene vinyl acetate copolymer may have a melt index (MI) of 1 to 5 g / 10 min, or 1 to 60 g / 10 min, under measurement conditions of 190°C and 2.16 kg.

[0088] In addition, the polyethylene vinyl acetate copolymer may have a weight average molecular weight of 10,000 to 1,000,000 g / mol, but is not limited thereto. Under the above conditions, the processability and mechanical properties of the polyethylene-vinyl acetate vitriol may be excellent. For example, the polyethylene vinyl acetate copolymer may have a weight average molecular weight of 100,000 to 800,000 g / mol or 150,000 to 500,000 g / mol.

[0089] In one embodiment of the present invention, the polyethylene vinyl acetate copolymer is a copolymer of ethylene and vinyl acetate, but may also be produced by polymerizing monomers such as alpha-olefin monomers, acrylate monomers, and methacrylate monomers in addition to the monomers. As examples, the copolymer may include, but is not limited to, an ethylene / methacrylic acid / vinyl acetate copolymer, an ethylene / propylene / vinyl acetate copolymer, an ethylene / propylene / methacrylic acid / vinyl acetate copolymer, and the like.

[0090]

[0091] Next, a mixed compound containing the first compound and the second compound of the present invention will be described.

[0092] The present invention relates to a polyethylene-vinylacetate copolymer resin composition (hereinafter, EVA composition) in which a mixed compound containing a first compound represented by the following chemical formula 1 and a second compound represented by the following chemical formula 2 is mixed with a polyethylene-vinylacetate copolymer (hereinafter, EVA resin), and a polyethylene-vinylacetate copolymer vitrimer (hereinafter, EVA vitrimer) produced therefrom, wherein the first compound and the second compound have different central metals and are used in a mixture with the polyethylene-vinylacetate copolymer resin, and the vitrimer can be produced by heat processing.

[0093] In the present invention, a mixed compound composed of a first compound and a second compound having different central metals can be mixed with the polyethylene-vinyl acetate copolymer and reacted and processed by heat to provide an EVA vitrifier.

[0094] An EVA vitrimer, which is produced by reacting a mixed compound containing first and second compounds having different central metals with EVA, exhibits a relatively high complex viscosity at high temperatures and a change in rheological elasticity compared to conventional non-crosslinked EVA resins. The reason for this change in rheological properties at high temperatures, unlike conventional EVA resins, is presumed to be due to the crosslinking properties of the EVA vitrimer. When measuring rheological properties under low frequency conditions, the EVA vitrifier of the present invention exhibits a rheological behavior with a predominant elasticity like a thermosetting resin at a low temperature of 50°C or lower or 30°C or lower because the Storage modulus (G"), which represents elasticity, is larger than the Loss modulus (G'), which represents viscosity, and thus becomes similar to a cross-linked state, and at a high temperature of 100°C to 220°C or lower or 200°C or lower because the Loss modulus (G'), which represents viscosity, is larger than the Storage modulus (G"), thereby enabling the EVA vitrifier to exhibit thermoplastic resin properties that can be heat-processed, thereby imparting properties like a thermosetting resin at low temperatures and implementing properties like a thermoplastic resin at higher temperatures, unlike the conventional EVA resin itself.

[0095] When the EVA resin itself, which is heat-processed without including the above-mentioned mixed compound, shows changes in the rheological properties of the viscoelastic properties below 100°C, it can be seen that the EVA vitrifier of the present invention has been manufactured based on the fact that it shows thermoplastic properties similar to a crosslinked state at low temperatures and non-crosslinked at high temperatures.

[0096] According to one embodiment of the present invention, the mixed compound is composed of a first compound represented by the following chemical formula 1 and a second compound represented by the following chemical formula 2, and the mixed compound includes the first compound and the second compound having different central metals, and reacts with an EVA resin to produce the EVA vitrimer of the present invention. When the first compound and the second compound include the same central metal, the rheological properties aimed for in the present invention cannot be obtained, making it difficult to produce the polyethylene vinyl acetate vitrimer. In addition, the compound may exist in the form of a hydrate, but is not limited thereto.

[0097] [Chemical Formula 1]

[0098] M1(-O-L1-R1) n

[0099] [Chemical Formula 2]

[0100] M2(-O-L2-R2) m

[0101] In the above chemical formulas 1 and 2, M1 and M2 are different metal elements, L1 and L2 are each independently a single bond, -C(=O)-, -O-, or -OC(=O)-, and R1 and R2 are each independently hydrogen or C 1-30 is an alkyl group, and n and m are each independently 1, 2, 3, or 4.

[0102] For example, in the above chemical formula 1, when n is 2 or more, each L1 may be different from each other and each R1 may be different from each other, and similarly, in the above chemical formula 2, when m is 2 or more, each L2 may be different from each other and each R2 may be different from each other.

[0103] According to one embodiment of the present invention, the metal element that is the central metal of the first compound and the second compound may be an n-valent metal element, specifically a monovalent, divalent, trivalent, or tetravalent metal element. For example, it may be any one selected from an alkali metal, an alkaline earth metal, a transition metal, and a post-transition metal.

[0104] As non-limiting examples, the alkali metals may include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr); the alkaline earth metals may include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra); the transition metals may include metallic elements in periods 4 to 7 and groups 3 to 12 of the periodic table, such as scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), palladium (Pd), lutetium (Ru), molybdenum (Mo), zirconium (Zr), and platinum (Pt); and the post-transition metals may include metallic elements in the p-block of the periodic table, such as aluminum (Al), gallium (Ga), Examples include indium (In) and tin (Sn).

[0105] According to one embodiment of the present invention, M1 and M2 are different metal elements, and may each independently be any one metal element selected from lithium (Li), aluminum (Al), zinc (Zn), titanium (Ti), tin (Sn), molybdenum (Mo), etc. Specifically, M1 and M2 may each independently be any one metal element selected from aluminum (Al), tin (Sn), titanium (Ti), or zinc (Zn). In addition, at least one of the first compound and the second compound may include titanium (Ti) or aluminum (Al) as a central metal, while the other may include any one selected from lithium (Li), aluminum (Al), zinc (Zn), titanium (Ti), tin (Sn), molybdenum (Mo), etc., as a central metal, and thereby the central metals of the first compound and the second compound may be different from each other.

[0106] According to one embodiment of the present invention, L1 and L2 are each independently a single bond or -C(=O)-, and R1 and R2 are each independently hydrogen or C 1-15 is an alkyl group, and n and m may be 1, 2, 3, or 4. In addition, when n is 2 or more, each L1 may be different from each other and each R1 may be different from each other, and when m is 2 or more, each L2 may be different from each other and each R2 may be different from each other.

[0107] In one embodiment, in the above chemical formula 1, L1 is a single bond or -C(=O)-, and R1 is C 1-15 is an alkyl group, and n may be 2, 3, or 4, and when n is 2 or more, each L1 may be different from each other and each R1 may be different from each other. Specifically, in the chemical formula 1, L1 is a single bond, and R1 is C 1-7 is an alkyl group, wherein n may be 3 or 4, each L1 may be different from each other, and each R1 may be different from each other.

[0108] In another embodiment, in the above chemical formula 2, L2 is a single bond or -C(=O)-, and R2 is C 1-15 is an alkyl group, and m may be 1, 2 or 3, and when m is 2 or more, each L2 may be different from each other and each R2 may be different from each other. Specifically, in the chemical formula 2, L2 is -C(=O)-, and R2 is C 1-7 is an alkyl group, and m may be 1 or 2, and when m is 2 or more, each L2 may be different from each other and each R2 may be different from each other.

[0109] According to one embodiment of the present invention, non-limiting examples of compounds satisfying the chemical formula 1 or 2 include lithium acetate, aluminum ethoxide, aluminum iso-propoxide, aluminum tert-butoxide, aluminum tri-butoxide, aluminum tri-sec-butoxide, aluminum stearate, aluminum monostearate, zinc acetate, zinc acetate dihydrate, zinc stearate, zinc undecylenate, titanium (IV) n-butoxide, titanium (IV) isopropoxide, titanium Titanium tetraisopropoxide, stannous dioctoate, stannous dioleate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and bis(acetylacetonato) dioxomolybdenum(VI) may be mentioned. For example, the mixed compound may be a combination of any two compounds having different central metals among these examples, or a combination of any several compounds among these examples.

[0110] According to one embodiment of the present invention, at least one of the first compound and the second compound may include a transition metal or a post-transition metal as a central metal, and preferably, at least one of the first compound and the second compound may include titanium (Ti) or aluminum (Al) as a central metal. Alternatively, at least one of the first compound and the second compound may include titanium (Ti) or aluminum (Al) as a central metal, while the other may include lithium (Li) or zinc (Zn) as a central metal.

[0111] According to one embodiment of the present invention, at least one of the first compound and the second compound may be any one selected from aluminum ethoxide, aluminum iso-propoxide, aluminum tert-butoxide, aluminum tri-butoxide, aluminum tri-sec-butoxide, aluminum stearate, titanium (IV) n-butoxide, titanium (IV) isopropoxide, and titanium tetraisopropoxide. In addition, the other of the first compound and the second compound may be any one selected from lithium acetate, zinc acetate, zinc acetate dihydrate, zinc stearate, and zinc undecylenate.

[0112] According to one embodiment of the present invention, the mixed compound may be included in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the polyethylene-vinylacetate copolymer. When included under the above content conditions, the polyethylene-vinylacetate copolymer and the mixture may react to produce a polyethylene-vinylacetate vitrimer, and the produced polyethylene-vinylacetate vitrimer may have a higher complex viscosity at high temperatures than the raw material polyethylene-vinylacetate, be heat-processable compared to the cross-linked polyethylene-vinylacetate vitrimer, and be recyclable through repeated thermoforming. Specifically, the mixed compound may be included in an amount of 0.5 to 20 parts by weight, more specifically 1 to 15 parts by weight, or 5 to 15 parts by weight based on 100 parts by weight of the polyethylene-vinylacetate copolymer. For example, the above mixed compound is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, It may be included in 45, 46, 47, 48, 49 or 50 parts by weight.

[0113] According to one embodiment of the present invention, the first compound and the second compound may each independently be included in the mixed compound in an amount of 1 wt% or more, 5 wt% or more, or 50 wt% or more based on the total weight of the mixed compound, but is not necessarily limited thereto. When included under the above content conditions, the polyethylene-vinylacetate copolymer and the mixture have appropriate reactivity, and the manufactured polyethylene-vinylacetate vitriol has a higher complex viscosity at high temperatures than the raw material polyethylene-vinylacetate, is heat-processable compared to the cross-linked polyethylene-vinylacetate vitriol, and can be recycled through repeated thermoforming.

[0114] For example, if a mixed compound is composed of a first compound and a second compound, the composition ratio of the first compound to the second compound may be 1 to 99 wt% : 99 to 1 wt%, or 5 to 95 wt% : 95 to 5 wt%, or 50 to 95 wt% : 95 to 50 wt%. Specifically, the composition ratio of the first compound to the second compound may be 20 to 99 wt% : 1 to 80 wt%, or 30 to 95 wt% : 5 to 70 wt%, or 50 to 95 wt% : 5 to 50 wt%.

[0115] The present invention can provide a polyethylene-vinylacetate composition for producing a vitrimer (which may also be referred to as a polyethylene-vinylacetate resin composition), comprising the above-described polyethylene-vinylacetate copolymer; and a mixed compound containing a first compound represented by the above-described chemical formula 1 and a second compound represented by the above-described chemical formula 2; wherein the first compound and the second compound have different central metals. In addition, a polyethylene-vinylacetate vitrimer produced from the above-described composition can be provided.

[0116] In a polyethylene-vinyl acetate composition for producing a vitriol according to one embodiment of the present invention, the polyethylene-vinyl acetate copolymer may be included in an amount of 50 wt% or more, 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, 99 wt% or more, or 99.9 wt% or more based on the total weight of the composition.

[0117] The present invention can provide a molded article manufactured from the polyethylene-vinyl acetate composition for manufacturing the above-described vitrimer or a molded article manufactured from the polyethylene-vinyl acetate vitrimer. Examples of the molded article include those in the form of foam, sheet, roll, film, etc., but the molded article can be easily adjusted depending on the processing method. In particular, the polyethylene-vinyl acetate vitrimer has properties suitable for manufacturing a foam, and a molded article manufactured through the polyethylene-vinyl acetate vitrimer can be remolded, thereby realizing excellent environmental friendliness.

[0118]

[0119] Hereinafter, the method for manufacturing EVA vitrifier of the present invention will be described.

[0120] The method for manufacturing the bitrimer of the present invention can be manufactured by thermally processing the EVA bitrimer composition described above. The thermally processing method can be by kneading or extrusion.

[0121] Specifically, the method for manufacturing the vitrimer may include a step of premixing a mixed compound containing an EVA resin and the first and second compounds using a mixing means such as a Brabender, a step of reacting the premixed EVA resin by mixing it in an extruder, and extruding it to manufacture pellets. The reaction temperature according to the extrusion mixing may be performed at 150°C, or 150 to 250°C.

[0122] In addition, when molding using the above EVA bitrimer, it is possible to mold simultaneously with the reaction using the above extruder or injection molding machine, or it can be manufactured by limiting it to pellets as described above, mixing the pellets with other preparations, and re-extruding, injection molding, press molding, or vacuum molding. In addition, if necessary, a foaming agent can be added to manufacture a foamed body.

[0123] The polyethylene-vinyl acetate vitriol manufactured by the above-described method has the same effect as forming a cross-linked structure, exhibiting the behavior of a thermosetting resin at low temperatures and the behavior of a thermoplastic resin at high temperatures. Accordingly, it can be recycled through a bond exchange reaction without decomposition, and even after multiple remolding, the deterioration of cross-linking properties such as mechanical strength and heat resistance is minimal, allowing for repeated recycling.

[0124] According to one embodiment of the present invention, the polyethylene-vinyl acetate bitrimer may have a complex viscosity higher than that of the polyethylene-vinyl acetate copolymer itself as a raw material at 115°C as a result of a temperature sweep test under conditions of an angular frequency of 0.1 to 5 rad / s and a shear strain of 1 to 30%, as shown in FIG. 1.

[0125] For example, the complex viscosity of the polyethylene-vinyl acetate bitrimer may be 1.5 times or more, 2 times or more, 2.5 times or more, 3 times or more, or 4 times or more than the complex viscosity of the polyethylene-vinyl acetate copolymer.

[0126] For example, the polyethylene-vinyl acetate vitrifier has a complex viscosity of 50,000 Pa. . s or less, 40,000 Pa . s or less, or 25,000 Pa . It can be less than s, and the lower limit is not limited, but 5,000 Pa . s or more, 7,000 Pa .s or more, or 10,000 Pa . It may be s or more. In the case of a vitrifier satisfying the above range, it has the advantage of exhibiting higher melt tension or melt strength than the conventional EVA resin itself, which is advantageous in maintaining the pore shape during foam processing.

[0127] According to one embodiment of the present invention, the polyethylene-vinyl acetate vitrimer may have a Tanδ(G" / G') of 1 or more at 200°C as a result of a temperature sweep test under an angular frequency condition of 1 rad / s or less, 0.5 rad / s or less, or 0.1 rad / s or less, specifically, an angular frequency measurement condition of 0.1 rad / s and a shear strain condition of 1 to 30%, as shown in FIG. 2. That is, the vitrimer may have a crosspoint where the elastic modulus (G") becomes lower than the viscous modulus (or loss modulus) at 100 to 220°C, or 200°C or less. Specifically, the above-mentioned vitrifier exhibits a rheological behavior with a high elasticity, such as a thermosetting resin, at low temperatures of 50°C or lower or 30°C or lower, since the Storage modulus (G"), which represents elasticity, is greater than the Loss modulus (G'), which represents viscosity, and behaves similarly to a cross-linked state. However, at high temperatures of over 100°C or about 200°C, the Loss modulus (G') is greater than the Storage modulus (G"), and thus the vitrifier may exhibit thermoplastic resin properties that are heat-processable.

[0128] The above vitrifier exhibits a higher complex viscosity at a high temperature of 115°C than that of a conventional non-crosslinked EVA resin, which allows for confirmation of crosslinking. In addition, the chemically crosslinked EVA without including the mixed compound according to one embodiment exhibits a Tanδ(G" / G') of less than 1 even at a high temperature of 200°C and even at 100°C, and the elastic modulus (G") is higher than the viscous modulus (G`) in a low frequency range (measuring condition of angular frequency of 0.1 rad / s). It can be seen that the manufactured EVA vitrifier has thermoplastic properties similar to a crosslinked state at low temperatures and non-crosslinked at high temperatures, and based on this, it can be seen that the EVA vitrifier targeted by the present invention has been manufactured.

[0129] According to one embodiment of the present invention, the polyethylene-vinyl acetate vitrimer or vinyl acetate-based vitrimer composition may have a difference in the crossover temperature at which tanδ(=G" / G')=1 measured before and after five reprocessings under temperature conditions of 150 to 200°C is 15°C or less, 10°C or less, or 5°C or less. In this case, the crossover temperature is performed under the same conditions as the temperature sweep test measurement described below.

[0130] According to one embodiment of the present invention, the elongation at break (E0) of the polyethylene-vinyl acetate vitriol is measured according to ASTM D638 to the elongation at break (E0) of the polyethylene-vinyl acetate copolymer. i ) of the ratio (E) i / E0) may be 0.8 or more. For example, the elongation at break (E0) of the polyethylene-vinyl acetate vitriol to the elongation at break (E) of the polyethylene-vinyl acetate copolymer i ) of the ratio (E) i / E0) can be 0.9 or greater or 1.0 or greater. For example, it can be 5 or less.

[0131] According to one embodiment of the present invention, the polyethylene-vinyl acetate vitrifier is reprocessed at least once under temperature conditions of 150 to 200°C and then has an elongation at break (E) measured according to ASTM D638. r ) is the elongation at break (E) before reprocessing i ) is equal to or higher than (E i <E r ), or 50% of the elongation at break before reprocessing (0.5xE i ) is higher than (0.5xE i <E r ) may be. Specifically, the polyethylene-vinyl acetate vitrifier may be 0.5xE i < E r < 5xE i , 0.8xE i < E r < 3xE i , 0.9xE i < E r < 3xE i , or E i < E r < 2xE i may satisfy, but is not limited to.

[0132] The above reprocessing can be performed without significant limitations as long as it is a conventional or known polymer processing method, and can be performed in a processing device such as a mixer, injection molding machine, or extruder at a processing temperature of 120 to 250°C, specifically 150 to 220°C, and a Screw RPM of 20 to 200 rpm, specifically 50 to 100 rpm, for 1 to 120 minutes, specifically 3 to 60 minutes, but is not limited thereto.

[0133]

[0134] Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, the following examples are intended to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples.

[0135]

[0136] [Example 1]

[0137] 100 parts by weight of polyethylene vinylacetate copolymer (EVA) (Hanwha Solutions, product name: 1828, VA content 28%, MI: 4 g / 10 min), 4 parts by weight of lithium acetate, and 6 parts by weight of titanium (IV) butoxide were added to a mixer (Measuring Mixer W50, Brabender), and mixed for 10 minutes at 190°C and Screw RPM 50 rpm to produce EVA.

[0138] As a result of the temperature sweep test of the EVA manufactured above, as shown in Fig. 1, it can be confirmed that the complex viscosity increases and crosslinking progresses compared to Comparative Example 1. In addition, as shown in Fig. 2, a cross point with a Tanδ value of 1.01 at 200°C can be confirmed. In other words, it can be seen that the cross point (cross temperature) where the viscoelastic properties are reversed each other is shown, so that it exhibits thermosetting properties at low temperatures and thermoplastic properties above the cross temperature, and through this, it can be seen that the EVA vitrifier targeted in the present invention was manufactured. In addition, the physical properties of the vitrifier manufactured in Example 1 are shown in Table 2 below.

[0139]

[0140] [Example 2]

[0141] The same procedure as in Example 1 was followed, except that 4 parts by weight of zinc acetate dehydrate and 6 parts by weight of titanium butoxide were used instead of lithium acetate. The resulting physical properties are shown in Table 1. Similar to Example 1, a higher complex viscosity was observed than in Comparative Example 1, confirming the progress of crosslinking. In addition, the production of a vitrifier was confirmed by confirming that the Tanδ value was 1.0 or higher at 200°C. In addition, the measured physical properties are shown in Table 2 below.

[0142] .

[0143] [Example 3]

[0144] The same procedure as in Example 1 was followed, except that 3 parts by weight of zinc acetate was used instead of lithium acetate, and 5 parts by weight of aluminum isopropoxide was used instead of titanium butoxide. Similar to Example 1, a higher complex viscosity was observed than in Comparative Example 1, confirming the progress of crosslinking. Furthermore, the production of a vitrifier was confirmed by confirming that the Tanδ value was 1.0 or higher at 200°C. In addition, the measured physical properties are shown in Table 2 below.

[0145]

[0146] [Comparative Example 1]

[0147] Only the polyethylene-vinyl acetate copolymer used in Example 1 was processed and its properties were measured. The resulting properties are shown in Table 2.

[0148]

[0149] [Comparative Example 2]

[0150] The same procedure as Example 1 was followed, except that lithium acetate and titanium butoxide were not added and 0.6 parts by weight of DCP (Dicumylperoxide) was added. The resulting physical properties are shown in Table 2.

[0151]

[0152] [Comparative Example 3]

[0153] The same procedure as Example 1 was followed, except that only 6 parts by weight of titanium butoxide was added instead of lithium acetate. The resulting physical properties are shown in Table 2.

[0154]

[0155] [Comparative Example 4]

[0156] The same procedure as in Example 3 was followed, except that only 5 parts by weight of aluminum isopropoxide was added instead of zinc acetate. The resulting physical properties are shown in Table 2.

[0157]

[0158] [Evaluation Example] Recyclability Evaluation

[0159] The polyethylene-vinyl acetate vitrimer according to Examples 1 to 5 and Comparative Examples 1 and 2 was re-introduced into the mixer and reprocessed multiple times (5 times) under the same conditions. The rheological properties and elongation at break of the reprocessed polyethylene-vinyl acetate vitrimer after reprocessing were measured according to the following methods and are shown in Figure 3 below. However, the polyethylene-vinyl acetate copolymer of Comparative Example 1 was reprocessed once.

[0160]

[0161] <Method of measuring physical properties>

[0162] 1. Rheological properties

[0163] (1) Complex viscosity [Pa·S]

[0164] In order to analyze the rheological properties of the polyethylene-vinyl acetate vitrifier of the present invention, rheology was measured using a rheometer (Modular Compact Rheometer 702 (MCR 702, Anton Paar)). The measurement specimen was manufactured into a 2 mm thick sheet using a hot press, and was used after cutting into a rectangular size of 10 to 15 mm in width and 20 to 30 mm in height. The tortion evaluation was performed according to temperature under the conditions of normal force of 0 to 1 N, heating temperature of 30 to 120°C (measured from low temperature to high temperature), angular frequency of 0.1 to 5 rad / s, and shear strain of 1 to 30% (specifically, about 1%). Complex viscosity (Pa s) according to temperature change of the solid specimen . s) The graph is shown in Fig. 1. In addition, the complex viscosity values ​​at high temperature (115°C) that can estimate crosslinking characteristics are shown in Table 2.

[0165] (2) tanδ(=G" / G')

[0166] In order to analyze the rheological properties of the polyethylene-vinyl acetate vitrifier of the present invention, rheology was measured using a parallel plate rheometer (Modular Compact Rheometer 702 (MCR 702, Anton Paar)). The measurement specimen was manufactured into a sheet with a diameter of 25 mm and a thickness of 1 mm using a hot press, and a temperature sweep test was performed under the conditions of a normal force of 1 N, a cooling temperature of 80 to 220°C (measured by cooling from a high temperature to a low temperature), an angular frequency of 0.1 rad / s or less (0.1 rad / s), and a shear strain of 1% to 30% (specifically, about 1%). The graph of the rheological properties (storage modulus (G') and loss modulus (G")) according to temperature change is shown in Fig. 2. At this time, the part [tanδ(=G" / G')=1] where G' and G" show the same value (where G' and G" intersect in the graph) was defined as the intersection temperature, and the tanδ(=G" / G') value at high temperature (200℃), which is the processing temperature range, is shown in Table 2 below.

[0167] 2. Elongation at break [%]

[0168] The elongation at break of polyethylene-vinyl acetate vitrifier was measured according to ASTM D638 using a UTM (Intstron 5966 USA). The specimens were manufactured according to Type Ⅵ of ASTM D638, and the measurements were made at 25°C with a 250 N load cell and a crosshead speed of 200 mm / min. The measured results are shown in Figure 3 below.

[0169]

[0170] The compositions of the above examples and comparative examples are summarized below.

[0171] [Table 1]

[0172]

[0173] [Table 2]

[0174]

[0175]

[0176] As shown in Table 2 and Figures 1 and 2, the polyethylene-vinyl acetate vitrifiers of Examples 1 to 3 each had a complex viscosity of 5,000 to 50,000 Pa at 115°C. . s, preferably 10,000 to 25,000 Pa . s, and tanδ at 200°C was 1 or less. This shows that the vitrimers of Examples 1 to 3 of the present invention exhibited a higher complex viscosity at 115°C than Comparative Example 1, which is a conventional EVA resin (polyethylene-vinyl acetate copolymer). In addition, the vitrimers of Examples 1 to 3 all exhibited a crossover temperature, i.e., a crosspoint, at temperatures of 100 to 220°C, confirming that the vitrimer according to one embodiment has both crosslinking properties and recyclability.

[0177] In particular, in the case of Examples 1 and 2, they have a high complex viscosity compared to the non-crosslinked Comparative Example 1, and through this characteristic, it can be seen that the bitrimer according to one embodiment has excellent crosslinking properties, and has the advantage of exhibiting melt tension or melt strength that is advantageous during processing compared to Comparative Example 1, which has a complex viscosity that is too low, or Comparative Examples 3 and 4, which have an excessively high complex viscosity.

[0178] Specifically, in Fig. 2, based on the temperature where Tanδ=1, if G' shows a tendency to be generally lower than G" above that temperature, it means that the flow properties (viscosity) of the polymer are dominant, and if G' is higher than G" over the entire temperature range of the graph as in Comparative Example 2, it means that the solid properties (elasticity) are more dominant. In the case of Example 1, at 100℃, G' is higher than G", showing solid properties, but it was confirmed that, starting from the crossover temperature where Tanδ=1, the flow properties (viscosity) where G' is lower than G" become dominant as the temperature increases. In other words, Tanδ(=G" / G') being 1 or more at a temperature of 200℃ indicates flow properties at 200℃, which may mean that reprocessing is possible. As shown in Table 2 above, Examples 1 to 3 all showed Tanδ(=G" / G') being 1 or more at a temperature of 200℃, but Comparative Examples 2 to 4 all showed Tanδ(=G" / G') being less than 1 at a temperature of 200℃, indicating elasticity, making recycling difficult. Through this, it was confirmed that the vinyl acetate-based vitriol composition according to one embodiment maintains excellent mechanical properties at low temperatures and has superior flow properties at high temperatures, making reprocessing possible.

[0179] In addition, through FIG. 3, it was confirmed that the vinyl acetate-based vitriol composition according to one embodiment can maintain similar rheological properties even after multiple reprocessings by showing a crosspoint at a temperature near 200°C even after five reprocessings.

[0180] In addition, as a result of measuring the change in elongation at break before / after one reprocessing of Example 1 and Comparative Example 2, it was confirmed that Example 1 increased by approximately 120% from the initial value from 410% to 510% after one reprocessing, whereas Comparative Example 2, which is a cross-linked EVA, rapidly decreased by 30% from 250% to 75% after one reprocessing. Through this, it was confirmed that the bitrimer according to one embodiment can be recycled multiple times because the physical properties such as the elongation at break did not deteriorate excessively even after reprocessing, such that the elongation at break did not excessively increase or decrease.

[0181] As described above, the present invention has been described with specific details and limited examples and drawings, but these are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above examples, and those skilled in the art to which the present invention pertains can make various modifications and variations based on this description.

[0182] Therefore, the idea of ​​the present invention should not be limited to the described embodiments, and all things that are equivalent or equivalent to the claims described below as well as the claims are considered to fall within the scope of the idea of ​​the present invention.

Claims

1. Polyethylene-vinyl acetate copolymer; and A polyethylene-vinylacetate vitriol manufactured from a composition comprising a mixed compound containing a first compound and a second compound, The above first compound is represented by the following chemical formula 1, The second compound is a polyethylene-vinyl acetate vitriol represented by the following chemical formula 2: [Chemical Formula 1] M 1 (-O-L 1 -R 1 ) n [Chemical formula 2] M 2 (-O-L 2 -R 2 ) m (In the above chemical formulas 1 and 2, M 1 and M 2 are different metallic elements, L 1 and L 2 are each independently a single bond, -C(=O)-, -O-, and -OC(=O)-, R 1 and R 2 are each independently hydrogen or C 1-30 is a substituted or unsubstituted alkyl group, n and m are each independently 1, 2, 3, or 4).

2. In the first paragraph, the metal element is a polyethylene-vinyl acetate vitriol selected from an alkali metal, an alkaline earth metal, a transition metal, and a post-transition metal.

3. A polyethylene-vinylacetate vitriol in the first paragraph, wherein at least one of the first compound and the second compound contains a transition metal or a post-transition metal as a central metal.

4. A polyethylene-vinyl acetate vitriol in the first paragraph, wherein at least one of the first compound and the second compound contains titanium (Ti) or aluminum (Al) as a central metal.

5. In paragraph 1, the M 1 and M 2 Polyethylene-vinylacetate vitriol, each independently lithium (Li), aluminum (Al), zinc (Zn), titanium (Ti), tin (Sn), or molybdenum (Mo).

6. In paragraph 1, the L 1 and L 2 are each independently a single bond or -C(=O)-, and the R 1 and R 2 are each independently hydrogen or C 1-15 A polyethylene-vinylacetate bitrimer, wherein n and m are each independently 1, 2, 3, or 4.

7. In the first paragraph, the polyethylene-vinyl acetate vitriol is contained in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the polyethylene-vinyl acetate copolymer.

8. In the 7th paragraph, the first compound and the second compound are each independently included in an amount of at least 5 wt% based on the total weight of the mixed compound, a polyethylene-vinyl acetate vitriol.

9. In the first paragraph, the polyethylene-vinyl acetate vitrimer has a Tanδ(G" / G') of 1 or more at 200°C as a result of a temperature sweep test under an angular frequency condition of 0.1 rad / s or less and a shear strain condition of 1 to 30%.

10. In the first paragraph, the polyethylene-vinylacetate vitrimer is a polyethylene-vinylacetate vitrimer, wherein, as a result of a temperature sweep test under an angular frequency condition of 0.1 to 5 rad / s and a shear strain condition of 1 to 30%, the complex viscosity of the polyethylene-vinylacetate vitrimer at 115°C is higher than the complex viscosity of the polyethylene-vinylacetate copolymer.

11. In the first paragraph, the elongation at break (E) measured according to ASTM D638 after reprocessing the polyethylene-vinyl acetate vitrifier at least once under temperature conditions of 150 to 200°C r ) is the elongation at break (E) before reprocessing. i ) polyethylene-vinyl acetate vitriol having a higher molecular weight.

12. A molded product manufactured from a polyethylene-vinyl acetate vitrifier according to any one of claims 1 to 11.

13. Polyethylene-vinyl acetate copolymer; and A mixed compound comprising a first compound and a second compound; The above first compound is represented by the following chemical formula 1, A polyethylene-vinyl acetate composition for producing a vitriol, wherein the second compound is represented by the following chemical formula 2. [Chemical Formula 1] M 1 (-O-L 1 -R 1 ) n [Chemical formula 2] M 2 (-O-L 2 -R 2 ) m In the above chemical formulas 1 and 2, M 1 and M 2 are different metallic elements, L 1 and L 2 are each independently a single bond, -C(=O)-, -O-, and -OC(=O)-, R 1 and R 2 are each independently hydrogen or C 1-30 is a substituted or unsubstituted alkyl group, n and m are each independently 1, 2, 3, or 4.

14. A polyethylene-vinyl acetate composition for producing a bitrimer, wherein the metal element in paragraph 13 is any one selected from an alkali metal, an alkaline earth metal, a transition metal, and a post-transition metal.

15. A polyethylene-vinyl acetate composition for producing a bitrimer in claim 13, wherein at least one of the first compound and the second compound contains a transition metal or a post-transition metal as a central metal.

16. A polyethylene-vinyl acetate composition for producing a vitriol in claim 13, wherein at least one of the first compound and the second compound contains titanium (Ti) or aluminum (Al) as a central metal.

17. In the 13th paragraph, the M 1 and M 2 A polyethylene-vinyl acetate composition for manufacturing a bitrimer, wherein each of the bitrimer is independently selected from lithium (Li), aluminum (Al), zinc (Zn), titanium (Ti), tin (Sn), and molybdenum (Mo).

18. In the 13th paragraph, the L 1 and L 2 are each independently a single bond or -C(=O)-, and the R 1 and R 2 are each independently hydrogen or C 1-15 A polyethylene-vinyl acetate composition for producing a vitriol, wherein n and m are each independently 1, 2, 3, or 4.

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