Plasticizer composition and resin composition including the same

Abstract

This invention relates to a plasticizer composition comprising 2-ethylhexyl (2-hydroxyethyl) p-phthalate, di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate, wherein the content of 2-ethylhexyl (2-hydroxyethyl) p-phthalate is 20 wt% or less based on the total plasticizer composition, and when the plasticizer composition is applied to resin, it can improve mechanical properties, anti-migration properties, and loss properties.

Description

Technical Field

[0001] The present invention relates to a plasticizer composition comprising 2-ethylhexyl (2-hydroxyethyl) p-phthalate, di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate, and a resin composition comprising the plasticizer composition. Cross-referencing of related applications []

[0002] This case claims the benefit of Korean Patent Application No. 10-2022-0024956, filed on February 25, 2022, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. [] Prior Technology

[0003] [] []

[0004] Typically, in plasticizers, alcohols react with polycarboxylic acids such as phthalic acid and adipic acid to form corresponding esters. Furthermore, considering domestic and international regulations concerning phthalate-based plasticizers that are harmful to human health, ongoing research has been conducted on plasticizer compositions that can replace phthalate-based plasticizers, such as phthalate-based, adipic acid ester-based, and other polymer-based plasticizers.

[0005] Meanwhile, in all plastics sol industries, the car-rendering industry, or the extrusion / injection compound industry that manufactures finished products such as flooring, wallpaper, soft and hard sheets, gloves, cables, hoses, and films, the demand for such environmentally friendly products is increasing. In order to enhance the quality characteristics, processability, and productivity of each finished product, appropriate plasticizers should be used with consideration for fading, migration, mechanical properties, etc.

[0006] In these different application areas, according to the characteristics required by each industry, such as tensile strength, elongation, light resistance, migration, gelation, or absorption rate, auxiliary raw materials such as plasticizers, fillers, stabilizers, viscosity reducers, dispersants, defoamers, and foaming agents are mixed into PVC resin.

[0007] For example, among plasticizer compositions applicable to PVC, when using the relatively inexpensive and most commonly used di(2-ethylhexyl) phthalate (DEHTP), the hardness or sol viscosity is high, the absorption rate of the plasticizer is relatively slow, and migration and stress deterioration are poor.

[0008] To improve this, the product of the butanol transesterification reaction can be used as a plasticizer as a DEHTP-containing component. However, although the plasticizing efficiency is improved, the mechanical properties are slightly reduced, and there is a regional problem of plasticizer leakage due to heat or physical force.

[0009] In addition, ensuring environmental protection has become very important recently. This includes not only ensuring the environmental friendliness of the final products themselves, but also ensuring the environmental friendliness of the supply, demand and methods of raw materials. However, this conflicts with the industry's primary task of ensuring cost competitiveness. Therefore, it is necessary to develop products that are environmentally friendly in terms of raw materials, preparation processes and final products, and are also cost-competitive. Summary of the Invention

[0010] Technical issues

[0011] This invention provides an environmentally friendly plasticizer composition that is non-toxic to reproductive system development and has properties equal to or higher than those of typical phthalate ester plasticizers by applying the composition obtained from the transesterification reaction of 2-ethylhexyl (2-hydroxyethyl) p-phthalate and di(2-ethylhexyl) p-phthalate with n-butanol during the decomposition process of polyethylene p-phthalate to plasticizers.

[0012] Furthermore, the present invention provides a method for preparing plasticizer compositions that can economically and environmentally prepare plasticizer compositions with excellent physical properties by using waste polyethylene terephthalate as a raw material. Technical solution

[0013] To address the aforementioned problems, the present invention provides a plasticizer composition, a method for preparing the plasticizer composition, and a resin composition comprising the plasticizer composition.

[0014] (1) The present invention provides a plasticizer composition comprising 2-ethylhexyl (2-hydroxyethyl) p-phthalate, di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate, wherein the content of 2-ethylhexyl (2-hydroxyethyl) p-phthalate is 20 wt% or less based on the total plasticizer composition.

[0015] (2) In (1) above, the present invention provides a plasticizer composition wherein the content of 2-ethylhexyl (2-hydroxyethyl) phthalate is from 0.01 wt% to 15 wt%.

[0016] (3) In (1) or (2) above, the present invention provides a plasticizer composition, wherein the plasticizer composition further comprises n-butyl (2-hydroxyethyl) p-phthalate.

[0017] (4) In any one of (1) to (3) above, the present invention provides a plasticizer composition, wherein the plasticizer composition further comprises di(n-butyl) isophthalate, (n-butyl)(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) isophthalate.

[0018] (5) In any one of (1) to (4) above, the present invention provides a plasticizer composition, wherein the plasticizer composition further comprises byproducts including any or more of the dimer compounds represented by formulas 1 to 5.

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] (6) In (5) above, the present invention provides a plasticizer composition, wherein the total content of the byproduct in the composition is from 0.1 wt% to 5.0 wt%.

[0025] (7) In (5) or (6) above, the present invention provides a plasticizer composition, wherein the weight ratio of the byproduct in the composition to 2-ethylhexyl (2-hydroxyethyl) phthalate is 1:1 to 10.

[0026] (8) In (5) to (7) above, the present invention provides a plasticizer composition, wherein the weight ratio between the byproduct in the composition and the total content of di(n-butyl) phthalate, di(n-butyl)(2-ethylhexyl) phthalate and di(2-ethylhexyl) phthalate is 1:20.0 to 150.0.

[0027] (9) The present invention provides a method for preparing a plasticizer composition according to any one of (1) to (8), wherein the method comprises a step of mixing polyethylene terephthalate and 2-ethylhexanol in the presence of a catalyst to carry out an esterification reaction, wherein the product of the esterification reaction comprises 2-ethylhexyl (2-hydroxyethyl) terephthalate and di(2-ethylhexyl) terephthalate.

[0028] (10) In (9) above, the present invention provides a method for preparing a plasticizer composition, wherein polyethylene terephthalate is mixed in an amount of 80 wt% or less relative to the total content of polyethylene terephthalate and 2-ethylhexanol.

[0029] (11) In (9) or (10) above, the present invention provides a method for preparing a plasticizer composition, wherein polyethylene terephthalate is mixed in an amount of 60 wt% or less relative to the total content of polyethylene terephthalate and 2-ethylhexanol.

[0030] (12) In any one of (9) to (11) above, the present invention provides a method for preparing a plasticizer composition, wherein the polyethylene terephthalate comprises waste and recycled polyethylene terephthalate.

[0031] (13) The present invention provides a resin composition comprising 100 parts by weight of resin and 5 to 150 parts by weight of a plasticizer composition according to any one of (1) to (8).

[0032] (14) In (13) above, the present invention provides a resin composition, wherein the resin is selected from one or more of the group consisting of: linear vinyl chloride polymers, paste vinyl chloride polymers, ethylene-vinyl acetate copolymers, ethylene polymers, propylene polymers, polyketides, polystyrene, polyurethane, polylactic acid, natural rubber, and synthetic rubber. Beneficial effects

[0033] According to one embodiment of the present invention, the plasticizer composition is an environmentally friendly material that is non-toxic to reproductive system development, and when used in resin compositions, it can improve mechanical properties, anti-migration properties, stress migration, and absorption rate compared to typical plasticizers. Furthermore, this top-down preparation method utilizes waste materials, making it an environmentally friendly preparation method, and at the same time, it can have excellent cost competitiveness. Implementation

[0034] []

[0035] The words or terms used in this specification and claims should not be construed as limited to their meanings as defined in commonly used dictionaries. Based on the principle that the inventor can appropriately define the words or terms that best interpret this invention, it will be further understood that such words or terms should be interpreted as having a meaning consistent with their meaning in the relevant technical content and the technical concept of this invention.

[0036] [Terminology Definition]

[0037] The term "composition" as used herein includes not only reaction products and decomposition products formed from the materials of the corresponding composition, but also mixtures of materials that include the corresponding composition.

[0038] As used herein, "linear vinyl chloride polymer" is one type of vinyl chloride polymer, which is polymerized through suspension polymerization, bulk polymerization, or similar methods. This polymer consists of porous particles with many pores, ranging in size from tens to hundreds of micrometers, exhibiting non-cohesiveness and excellent flowability.

[0039] As used in this article, "paste-like vinyl chloride polymer" is one type of vinyl chloride polymer, which is polymerized through micro-suspension polymerization, micro-seed polymerization, emulsion polymerization, or similar methods. This polymer consists of non-porous, fine, and dense particles with a size of tens to thousands of nanometers, exhibiting cohesiveness and poor flowability.

[0040] The terms “comprising” and “having,” and their derivatives, whether expressly disclosed or not, are not intended to exclude the presence of any additional components, steps, or processes. To avoid any ambiguity, unless otherwise stated, any additional additives, supplements, or compounds, whether polymers or otherwise, may be included in the entirety of the composition claimed by the use of the term “comprising.” Conversely, the term “substantially constitutes…” excludes any other components, steps, or processes from the scope of any subsequent description unless they are not essential to operability. The term “consisting of…” excludes any components, steps, or processes not expressly stated or listed.

[0041] [Measurement Method]

[0042] In this specification, the content analysis of the components in the composition is performed by gas chromatography, and the analysis is performed using an Agilent gas chromatography apparatus (product name: Agilent 7890 GC, column: HP-5, carrier gas: helium (flow rate 2.4 mL / min), detector: FID, injection volume: 1 uL, initial value: 70℃ / 4.2 min, final value: 280℃ / 7.8 min, calculation rate: 15℃ / min).

[0043] In this specification, "hardness" refers to the Shore hardness (Shore "A" and / or Shore "D") measured at 25°C under the conditions of 3T 10s using ASTM D2240. It can be used as an indicator to evaluate plasticizing efficiency; the lower the hardness, the better the plasticizing efficiency.

[0044] In this specification, "tensile strength" is calculated by the following Equation 1 after the time point of fracture of a 1T specimen after being subjected to a tensile test using the ASTM D638 method and the UTM (manufacturer: Instron, model: 4466) at a crosshead speed of 200 mm / min.

[0045] [Equation 1] Tensile strength (kgf / cm²) = Load (kgf) / Thickness (cm) x Width (cm)

[0046] In this specification, "elongation" is calculated by the following Equation 2 after the time point at which the specimen breaks following a 1T tensile test using UTM at a crosshead speed of 200 mm / min according to the ASTM D638 method.

[0047] [Equation 2] Elongation (%) = Length after elongation / Initial length x 100

[0048] In this specification, "migration loss" can be measured according to KSM-3156. Specifically, a test specimen with a thickness of 1 mm is obtained, and absorbent sheets of organic material that can move to both sides of the test specimen to absorb the material expelled to the surface of the test specimen are added. Then, a plate covering the entire test specimen is attached to it to apply a load of 1 kgf / cm². The test specimen is placed in a hot air circulating oven (80°C) for 72 hours, then removed from the oven and cooled to room temperature for 4 hours. Afterward, the plate and the absorbent sheets attached to both sides of the test specimen are removed, and the weight of the specimen is measured before and after it remains in the oven to calculate the migration loss using Equation 3 below.

[0049] [Equation 3] Migration loss (%) = {[(initial sample weight) - (sample weight after standing in the oven)] / (initial sample weight)} x 100

[0050] In this specification, "volatilization loss" is obtained by treating the sample at 80°C for 72 hours and then measuring the weight of the sample.

[0051] [Equation 4] Volatilization loss (%) = {[(Initial sample weight) - (Treatment sample weight)] / (Initial sample weight)} x 100

[0052] Under various measurement conditions, the detailed conditions such as temperature, rotational speed, time, etc. may vary slightly, and when the detailed conditions differ, the measurement method and its conditions are specified separately.

[0053] In this specification, the "absorption rate" is evaluated by measuring the time taken to mix the resin and plasticizer together using a planetary mixer (Brabender, P600) until the torque of the mixer stabilizes, under conditions of 77°C and 60 rpm.

[0054] Under the various measurement conditions described above, detailed conditions such as temperature, rotational speed, time, etc., may vary slightly depending on the circumstances, and when the detailed conditions differ, the measurement methods and conditions are specified separately.

[0055] The invention will be described in more detail below to aid in understanding it.

[0056] [Plasticizer Composition] [] []

[0057] The present invention provides a plasticizer composition comprising 2-ethylhexyl (2-hydroxyethyl) p-phthalate, di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate, wherein the content of 2-ethylhexyl (2-hydroxyethyl) p-phthalate is 20 wt% or less based on the total plasticizer composition.

[0058] Plasticizer compositions containing 2-ethylhexyl (2-hydroxyethyl) phthalate and di(2-ethylhexyl) phthalate can be obtained by transesterification of a product manufactured by a transesterification reaction between polyethylene terephthalate (hereinafter referred to as PET) and 2-ethylhexanol and n-butanol.

[0059] Typically, as a means of obtaining di(2-ethylhexyl) phthalate, used as a typical general-purpose plasticizer, there are instances of reacting PET with 2-ethylhexanol. However, this involves the generation of numerous byproducts and difficulties in separating the bis(2-hydroxyethyl) phthalate or 2-ethylhexyl(2-hydroxyethyl) phthalate from di(2-ethylhexyl) phthalate produced during the reaction process. Furthermore, since bis(2-hydroxyethyl) phthalate and 2-ethylhexyl(2-hydroxyethyl) phthalate are alcohol compounds containing hydroxyl groups in their intramolecular structures, there is a possibility of other side reactions with the target product, di(2-ethylhexyl) phthalate. Therefore, as a method for preparing di(2-ethylhexyl) phthalate, almost every manufacturer uses the direct esterification reaction of phthalic acid with 2-ethylhexanol or the transesterification reaction of dimethyl phthalate with 2-ethylhexanol, rather than methods using PET as a raw material.

[0060] However, in this invention, it has been confirmed that by focusing on the function of 2-ethylhexyl (2-hydroxyethyl) p-phthalate, which is typically considered an impurity and therefore a target for removal, and by allowing a predetermined amount of 2-ethylhexyl (2-hydroxyethyl) p-phthalate to be included in the plasticizer composition instead of removing it, a plasticizer composition with improved performance compared to typical plasticizer products can be provided. 2-ethylhexyl (2-hydroxyethyl) p-phthalate is not easily separated from di(2-ethylhexyl) p-phthalate, but can be used to address the compression migration of di(2-ethylhexyl) p-phthalate, i.e., the problem of plasticizer expulsion due to heat or pressure. Specifically, due to the presence of hydroxyl groups in its intramolecular structure, 2-ethylhexyl (2-hydroxyethyl) p-phthalate can bond more firmly to the resin to be mixed and can play a role in retaining the main component of the plasticizer composition, di(2-ethylhexyl) p-phthalate, from being expelled from the resin.

[0061] Furthermore, the plasticizer composition of the present invention is obtained by further transesterification of the product obtained from the reaction between PET and 2-ethylhexanol with n-butanol, and includes a compound in which at least one 2-ethylhexyl group of di(2-ethylhexyl) phthalate is substituted with n-butyl, more specifically, including di(n-butyl) phthalate and (n-butyl)(2-ethylhexyl) phthalate. These two components supplement the plasticizing efficiency of di(2-ethylhexyl) phthalate and ethylhexyl(2-hydroxyethyl) phthalate in the plasticizer composition, thereby further improving the overall plasticizing efficiency of the plasticizer composition.

[0062] Based on the combined weight of di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate in the plasticizer composition, it may contain 0.1 wt% to 20 wt% of di(n-butyl) p-phthalate, 5 wt% to 50 wt% of (n-butyl)(2-ethylhexyl) p-phthalate, and 30 wt% to 90 wt% of di(2-ethylhexyl) p-phthalate. When the wt% of each component is within the above range, the overall physical properties are excellent, and the balance between the physical properties is also excellent.

[0063] According to one embodiment of the present invention, the content of 2-ethylhexyl (2-hydroxyethyl) phthalate, based on the total plasticizer composition, may be 20 wt% or less. For example, based on the total plasticizer composition, the content of 2-ethylhexyl (2-hydroxyethyl) phthalate may be 0.01 wt% or more, 0.05 wt% or more, 0.06 wt% or more, 0.08 wt% or more, 0.10 wt% or more, 0.50 wt% or more, 0.90 wt% or more, 1.0 wt% or more, 2.0 wt% or more, 3.0 wt% or more, 4.0 wt% or more, 4.5 wt% or more, 4.9 wt% or more, 5.0 wt% or more, 5.5 wt% or more, 7.5 wt% or more, 8.0 wt% or more, 20.0 wt% or less, 19.5 wt% or less, 19.0 wt% or less, 18.0 wt% or less, 17.0 wt% or less, 16.0 wt% or less, 15.0 wt% or less. wt% or less, 14.9 wt% or less, 14.5 wt% or less, 13.0 wt% or less, 12.8 wt% or less, 12.5 wt% or less, 12.4 wt% or less, 12.0 wt% or less, 11.7 wt% or less, 11.5 wt% or less, 11.3 wt% or less, 11.0 wt% or less, 10.5 wt% or less, 10.0 wt% or less, 9.5 wt% or less, 9.3 wt% or less, 8.0 wt% or less, 8.6 wt% or less, 8.5 wt% or less, 8.0 wt% or less, 7.5 wt% or less, 7.2 wt% or less, 7.0 wt% or less, 6.5 wt% or less, 6.0 wt% or less, 5.5 The content of phthalate esters may be 1.0 wt% or less, 5.0 wt% or less, 4.5 wt% or less, 4.0 wt% or less, 3.5 wt% or less, 3.0 wt% or less, 2.5 wt% or less, or 2.0 wt% or less. Preferably, the content of phthalate esters may be from 1.0 wt% to 20 wt% based on the total plasticizer composition. Furthermore, the weight ratio between 2-ethylhexyl (2-hydroxyethyl) phthalate and di(2-ethylhexyl) phthalate may be from 1:3.5 to 10000, more preferably from 1:3.5 to 1000, and even more preferably from 1:3.5 to 100.When the content of 2-ethylhexyl (2-hydroxyethyl) p-phthalate in the plasticizer composition is too low, the aforementioned effect on improving the anti-migration properties of 2-ethylhexyl (2-hydroxyethyl) p-phthalate will be negligible. Conversely, when the content of 2-ethylhexyl (2-hydroxyethyl) p-phthalate is too high, the content of di(2-ethylhexyl) p-phthalate becomes relatively low, resulting in poorer volatilization loss and an excessively increased absorption rate. This leads to instability in the blending with the resin and the processing conditions of the finished product. Consequently, the overall heat resistance of the resin composition or the finished product obtained from it will deteriorate. Specifically, when 2-ethylhexyl (2-hydroxyethyl) p-phthalate is included as a major component in the plasticizer composition, its relatively low molecular weight makes it difficult to blend with the resin, and the subsequent rolling process or similar procedures may not proceed smoothly. When the content of 2-ethylhexyl (2-hydroxyethyl) phthalate meets the above-mentioned preferred range, appropriate volatilization loss and appropriate absorption rate can be achieved, thus providing a plasticizer composition with excellent heat resistance and stable compatibility with resin components.

[0064] In addition to the components described above, the plasticizer composition of this invention may further include butyl(2-hydroxyethyl) p-phthalate. Similar to di(2-ethylhexyl) p-phthalate, butyl(2-hydroxyethyl) p-phthalate, formed by the transesterification reaction between PET and 2-ethylhexanol, can also react with subsequently added n-butanol. Furthermore, since the 2-ethylhexyl group of butyl(2-hydroxyethyl) p-phthalate is substituted with n-butyl, butyl(2-hydroxyethyl) p-phthalate can be included in the plasticizer composition. Butyl(2-hydroxyethyl) p-phthalate can achieve similar functions to the aforementioned butyl(2-hydroxyethyl) p-phthalate, and the amount included, based on the total plasticizer composition content, is 20 wt% or less, 15 wt% or less, 10 wt% or less, or 5 wt% or less.

[0065] In addition, the plasticizer composition of the present invention may further include di(n-butyl) isophthalate, (n-butyl)(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) isophthalate in addition to the above-mentioned components.

[0066] The molecular structure of polyethylene terephthalate (PET) contains trace amounts of isophthalate, which is an isomer of PET. This isophthalate structure can be converted into di(n-butyl) isophthalate, (n-butyl)(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) isophthalate through the aforementioned series of transesterification reactions. In typical reaction processes for recovering di(2-ethylhexyl) PET from PET, these isophthalate components are considered impurities and are therefore removed from the final composition. However, in this invention, when the aforementioned isophthalate components are partially included in the plasticizer composition, better physical properties can be achieved than when PET is used alone, while maintaining a balance of physical properties. Therefore, the plasticizer composition of this invention may further include di(n-butyl) isophthalate, (n-butyl)(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) isophthalate.

[0067] Because the isophthalate content in the reactant PET is low, the isophthalate component content in the plasticizer composition of the present invention obtained from PET is also low. Specifically, the combined content of these three components, based on the total composition, can be 5 wt% or less, preferably 0.3 wt% to 3 wt%. Due to the structure of the reactant PET, the isophthalate component content is not easily increased to above the above range, and when the isophthalate component content is below the above range, the improvement effect obtained by including the isophthalate component is negligible.

[0068] Meanwhile, when the plasticizer composition further includes di(n-butyl) isophthalate, (n-butyl)(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) isophthalate, the percentage of content therein can also be applied as the above-mentioned content of di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate.

[0069] According to one embodiment of the present invention, the plasticizer composition of the present invention may further include byproducts comprising any or more of the dimer compounds represented by formulas 1 to 5.

[0070]

[0071]

[0072]

[0073]

[0074]

[0075] In this invention, as described above, 2-ethylhexyl (2-hydroxyethyl) phthalate (a dimer compound, which is one of the byproducts) having the structure (p-phthalate or isophthalate)-(ethylene glycol)-(p-phthalate or isophthalate) is included in the plasticizer composition in a controlled manner at a predetermined content. Therefore, it has been confirmed that a plasticizer composition with improved performance compared to typical plasticizer products can be provided. The molecular structure of polyethylene terephthalate contains trace amounts of isophthalate, which is an isomer of p-phthalate. This isophthalate structure can be generated as a dimer compound containing isophthalate through the above-described series of transesterification reaction procedures.

[0076] The dimer compounds contained in the byproducts can be prepared in various forms and contents depending on the type of alcohol used or the reaction conditions in the depolymerization process of PET. Since compounds with this structure are included in the plasticizer composition together with phthalate plasticizers, they can compensate for the compression migration of typical phthalate plasticizers.

[0077] For example, in the process of synthesizing the monomer di(2-ethylhexyl) phthalate by reacting 2-ethylhexanol with PET, a dimer compound of 2-ethylhexanol bonded to each end of the two p-phthalic acids can be produced, and the dimer compound can be included in the final plasticizer composition.

[0078] The above-described procedure for forming dimer compounds is an example, and in addition to the above-described procedure, various combinations of dimer compounds can be formed by various reactions in di(2-hydroxyethyl) phthalate, 2-ethylhexyl(2-hydroxyethyl) phthalate, and 2-ethylhexyl(2-hydroxyethyl) isophthalate.

[0079] Furthermore, the contents of di(2-ethylhexyl) phthalate, 2-ethylhexyl(2-hydroxyethyl) phthalate, and the dimer compound can be controlled by deliberately controlling the transesterification reaction in the above preparation method. Simultaneously, in addition to the dimer compound, the byproducts may further include trimer and / or tetramer compounds. When controlling the reaction time during the transesterification reaction, a relatively large amount of byproducts such as trimer and / or tetramer compounds and dimer compounds may be generated depending on the reaction time. Due to the byproducts, the final processing physical properties of the overall plasticizer composition of di(2-ethylhexyl) phthalate and 2-ethylhexyl(2-hydroxyethyl) phthalate are maintained at an usable level without performance degradation. The reaction product containing the above-mentioned byproducts can be used as a plasticizer composition.

[0080] Furthermore, the content of byproducts can be determined based on the amount of catalyst used in the preparation method, the amount of 2-ethylhexanol and n-butanol to be added, the reaction pressure and time, the reaction progress time, etc. Specifically, as the amount of added n-butanol increases, n-butanol decomposes the bonds of the dimer compounds in the byproducts and converts the dimer compounds into p-phthaloyl(n-butyl)(2-ethylhexyl) ester and p-phthaloyl(n-butyl) ester. Therefore, the content of p-phthaloyl(n-butyl)(2-ethylhexyl) ester and p-phthaloyl(n-butyl) ester will increase, while the content of dimer compounds and byproducts containing them will decrease. In the plasticizer composition provided by the present invention, the total content of the byproduct of the dimer compound in the composition can be from 0.1 wt% to 5.0 wt%. For example, the total content of the dimer compound in the composition can be 0.1 wt% or more, 0.2 wt% or more, 0.3 wt% or more, 0.5 wt% or more, 0.8 wt% or more, 1.0 wt% or more, 1.2 wt% or more, 1.5 wt% or more, 5.0 wt% or less, 4.5 wt% or less, 4.0 wt% or less, 3.5 wt% or less, 3.2 wt% or less, 3.1 wt% or less, 3.0 wt% or less, 2.7 wt% or less, 2.5 wt% or less, 2.3 wt% or less, 2.0 wt% or less, or 1.7 wt% or less. Preferably, the total content of byproducts in the composition is from 0.5 wt% to 3.5 wt%. When the content of byproducts is controlled within the above range, a plasticizer composition with plasticizing efficiency properties equal to or higher than those of typical plasticizer products, as well as excellent mechanical properties such as tensile strength and tensile residual rate, migration loss, absorption rate, and stress resistance, can be provided.

[0081] Furthermore, the weight ratio of the byproducts in the composition to 2-ethylhexyl (2-hydroxyethyl) p-phthalic acid ester can be from 1:1 to 10, for example, 1:1.0 or greater, 1.2 or greater, 1.5 or greater, 1.7 or greater, 2.0 or greater, 2.5 or greater, 2.7 or greater, 3.0 or greater, 3.5 or greater, 4.0 or greater, 4.5 or greater, 4.7 or greater, 5.0 or greater, 10.0 or less, 9.7 or less, 9.5 or less, 9.2 or less, 9.0 or less, 8.5 or less, 8.3 or less, 8.0 or less, 7.5 or less, 7.0 or less, 6.5 or less, 6.0 or less, 5.7 or less, or 5.5 or less. Preferably, the weight ratio of the byproducts in the composition to 2-ethylhexyl (2-hydroxyethyl) p-phthalic acid ester can be from 1:5 to 8. When the weight ratio between the byproducts in the plasticizer composition and 2-ethylhexyl (2-hydroxyethyl) phthalate meets the above range, the effect of improving anti-migration properties can be excellent, and the volatilization loss and absorption rate can be excellent, so as to smoothly carry out the blending with the resin and the rolling process after blending, thus improving the processing stability.

[0082] Furthermore, the weight ratio between the byproducts in the composition and the total content of di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate can be from 1:20 to 150, for example, 1:20 or greater, 25 or greater, 30 or greater, 35 or greater, 40 or greater, 45 or greater, 50 or greater, 55 or greater, 60 or greater, 65 or greater, 70 or greater, 150 or less, 145 or less, 140 or less, 135 or less, 130 or less, 125 or less, 120 or less, 115 or less, 110 or less, 105 or less, 100 or less, 95 or less, 90 or less, 85 or less, 80 or less, or 75 or less. Preferably, the weight ratio of the byproducts in the composition to the total content of di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate can be from 1:20.0 to 80. When the ratio of the byproducts to the total content of di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate is within the above range, the effect of improving anti-migration properties achieved by including the byproducts containing dimer compounds in the plasticizer composition can be maximized.

[0083] A method for hydrogenating the plasticizer composition of the present invention can be applied. The present invention provides a plasticizer composition comprising 2-ethylhexyl(2-hydroxyethyl)cyclohexane-1,4-dicarboxylate and di(2-ethylhexyl)cyclohexane-1,4-dicarboxylate, wherein the content of 2-ethylhexyl(2-hydroxyethyl)cyclohexane-1,4-dicarboxylate is 20 wt% or less based on the total plasticizer composition. Furthermore, the plasticizer composition may further comprise a hydrogenated form of a dimer compound represented by formulas 1 to 5.

[0084] A plasticizer composition comprising 2-ethylhexyl(2-hydroxyethyl)cyclohexane-1,4-dicarboxylate and di(2-ethylhexyl)cyclohexane-1,4-dicarboxylate can be obtained by hydrogenation of a product produced by a transesterification reaction between polyethylene terephthalate (hereinafter referred to as PET) and 2-ethylhexanol, wherein the order of the transesterification and hydrogenation reactions may be reversed. The product comprises the aforementioned 2-ethylhexyl(2-hydroxyethyl) phthalate and di(n-butyl) phthalate, butyl(2-ethylhexyl) phthalate and di(2-ethylhexyl) phthalate, and may further comprise dimer compounds of formulas 1 to 5.

[0085] Plasticizer compositions can significantly improve migration and loss properties while eliminating environmental problems, and can achieve products with significantly improved light and heat resistance compared to typical commercial products.

[0086] [Method for preparing plasticizer compositions] [] []

[0087] The present invention provides a method for preparing the above-mentioned plasticizer composition.

[0088] Specifically, the present invention includes a method for preparing the above-mentioned plasticizer composition, the method comprising mixing polyethylene terephthalate and 2-ethylhexanol in the presence of a catalyst to carry out a transesterification reaction, and adding n-butanol to the reactants to carry out a transesterification reaction. The product produced by the transesterification reaction of polyethylene terephthalate and 2-ethylhexanol comprises 2-ethylhexyl (2-hydroxyethyl) terephthalate and di(2-ethylhexyl) terephthalate, and may further comprise byproducts of any or more of the dimer compounds represented by formulas 1 to 5 above.

[0089] PET and 2-ethylhexanol are converted into a composition containing both components through a transesterification reaction. Specifically, PET is represented by the following formula (a).

[0090]

[0091] In the transesterification reaction of PET and 2-ethylhexanol, 2-ethylhexanol reacts with the ester groups present in PET, thereby releasing the polymer chains of PET. Depending on the control of the reaction, the ratio of the two components, 2-ethylhexyl (2-hydroxyethyl) p-phthalate and di(2-ethylhexyl) p-phthalate, can be controlled. Importantly, not only the ratio of the two components is controlled within the above range, but also the ratio of byproducts containing dimer compounds is controlled within the above range.

[0092] Based on the total content of PET and 2-ethylhexanol, the composition may contain 80 wt% or less, preferably 60 wt% or less, more preferably 50 wt%, 40 wt%, or 35 wt% or less of PET. When the PET content is within the above range, the amount of 2-ethylhexanol added is sufficient to minimize this side reaction and maximize the desired transesterification reaction between PET and 2-ethylhexanol. In detail, when the PET content is within the above range, the composition obtained through this preparation process meets the above-mentioned preferred content conditions, thus having the advantage of directly preparing plasticizer compositions with excellent physical properties while minimizing post-processing after the preparation process.

[0093] Meanwhile, the PET may contain 50 wt% or more of waste PET, preferably 60 wt% or more, and even more preferably 70 wt% or more. Even with the use of waste PET, the component ratio in the final product remains unchanged. Therefore, as long as the color or plasticizer impurity content can be controlled, all waste PET can be used. As described above, the use of waste PET is extremely cost-competitive compared to di(2-ethylhexyl) phthalate manufactured from phthalic acid or dimethyl phthalate. The energy consumption used in the preparation of phthalic acid or dimethyl phthalate can be reduced, and environmental pollution can be prevented, thus making a significant contribution to environmental improvement.

[0094] In the preparation method according to one embodiment of the present invention, byproducts generated during the reaction, such as ethylene glycol, can be recovered outside the system, while some of them may remain in the reaction system. When some ethylene glycol remains in the reaction system to participate in the reaction, appropriate levels of 2-ethylhexyl (2-hydroxyethyl) p-phthalate and dimer compounds of formulas 1 to 5 can be formed from the ethylene glycol remaining in the reaction system. Since 2-ethylhexyl (2-hydroxyethyl) p-phthalate and dimer compounds of formulas 1 to 5 help improve the performance of the plasticizer composition, no additional energy is required to remove the formed 2-ethylhexyl (2-hydroxyethyl) p-phthalate and dimer compounds of formulas 1 to 5, thus the preparation process can be operated economically. In detail, since ethylene glycol is used as a reactant for forming 2-ethylhexyl (2-hydroxyethyl) p-phthalate and dimer compounds of formulas 1 to 5, the content of ethylene glycol in the final composition is naturally greatly reduced, thus having the advantage of simplifying the separation process.

[0095] Examples of catalysts may be selected from one or more of the following: acid catalysts, such as sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, p-toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butyric acid, and alkyl sulfuric acid; metal salts, such as aluminum lactate, lithium fluoride, potassium chloride, cesium chloride, calcium chloride, ferric chloride, and phosphoric acid; metal oxides, such as heteroacids; natural / synthetic zeolites; cation and anion exchange resins; catalysts containing choline compounds such as choline chloride, choline hydroxide, choline bicarbonate, choline stannate, dihydrocholine citrate, and choline sulfate; organometallic compounds, such as alkyl titanates, such as tetraalkyl titanate or polymers thereof; and organometallic compounds containing zirconium or tin. Preferably, the catalyst may be tetraalkyl titanate.

[0096] The amount of catalyst to be used may vary depending on its type. For example, homogeneous catalysts may be in the range of 0.01 wt% to 5 wt%, 0.01 wt% to 3 wt%, 1 wt% to 5 wt%, or 2 wt% to 4 wt% based on 100 wt% of reactants, while heterogeneous catalysts may be in the range of 5 wt% to 200 wt%, 5 wt% to 100 wt%, 20 wt% to 200 wt%, or 20 wt% to 150 wt% based on the total weight of reactants.

[0097] According to one embodiment of the present invention, the transesterification reaction is preferably carried out at a reaction temperature of 120°C to 240°C, more preferably 135°C to 230°C, and even more preferably 141°C to 220°C for 10 minutes to 12 hours, more preferably 30 minutes to 10 hours, and even more preferably 1 to 8 hours. Within the above temperature and time ranges, the composition ratio of the final plasticizer composition can be efficiently controlled. In this case, the reaction time can be calculated from the point when the temperature of the reactants is raised to the point when the reaction temperature is reached.

[0098] Furthermore, this method can be further included with the step of removing unreacted 2-ethylhexanol and the reaction byproduct ethylene glycol after the transesterification reaction is complete. Since ethylene glycol has high solubility in water, it can be removed after the reaction by neutralization and washing in water, and residual 2-ethylhexanol can be removed by extractive distillation after neutralization and washing in water. Through these steps, a plasticizer composition meeting the desired components and composition ratios can be prepared.

[0099] After completing the transesterification reaction between PET and 2-ethylhexanol, a transesterification reaction between the reaction product and n-butanol can be carried out. The conditions described above can also be used as the reaction conditions for this step, including the catalyst, reaction temperature, and time. In this step, the amount of n-butanol input, based on the weight of di(2-ethylhexyl) phthalate produced in the previous step, can be from 5 wt% to 40 wt%, preferably from 10 wt% to 30 wt%. When the amount of n-butanol input is appropriately controlled within the above range, it contains appropriate amounts of each component in the final plasticizer composition, thus maintaining an excellent overall physical property balance.

[0100] According to another embodiment of the present invention, a resin composition comprising the aforementioned plasticizer composition and resin is provided.

[0101] Resins well known in the art can be used as resins. For example, mixtures selected from one or more of the following groups can be used as resins: linear vinyl chloride polymers, paste-like vinyl chloride polymers, ethylene-vinyl acetate copolymers, ethylene polymers, propylene polymers, polyketides, polystyrene, polyurethane, polylactic acid, natural rubber, synthetic rubber, and thermoplastic elastomers. However, the invention is not limited thereto.

[0102] It may contain a plasticizer composition in an amount of 5 to 150 parts by weight, preferably 5 to 130 parts by weight, or 10 to 120 parts by weight, based on 100 parts by weight of resin.

[0103] Typically, resins containing plasticizer components can be processed into resin products through melt processing or plastisol processing, and melt-processed resins and plastisol-processed resins can be manufactured differently depending on the polymerization method.

[0104] For example, when vinyl chloride polymer systems are used in melt processing, solid resin particles with a large average particle size, manufactured by suspension polymerization or similar processes, are used; such vinyl chloride polymer systems are called linear vinyl chloride polymers. When used in plastisol processing, sol-like resins with fine resin particles, manufactured by emulsification polymerization or similar processes, are used; such vinyl chloride polymer systems are called paste-like vinyl chloride resins.

[0105] In the case of linear vinyl chloride polymers, the plasticizer is preferably contained in the range of 5 to 80 parts by weight based on 100 parts by weight of the polymer, and in the case of paste-like vinyl chloride polymers, the plasticizer is preferably contained in the range of 40 to 120 parts by weight based on 100 parts by weight of the polymer.

[0106] The resin composition may further include fillers. Based on 100 parts by weight of resin, the filler may be 0 to 300 parts by weight, preferably 50 to 200 parts by weight, and even more preferably 100 to 200 parts by weight.

[0107] The packing material can be any packing material known in the art and is not particularly limited. For example, the packing material can be a mixture of one or more of the following: silica, magnesium carbonate, calcium carbonate, hard coal, talc, magnesium hydroxide, titanium dioxide, magnesium oxide, calcium hydroxide, aluminum hydroxide, aluminum silicate, magnesium silicate, and barium sulfate.

[0108] In addition, the resin composition may contain other additives, such as stabilizers, as needed. Based on 100 parts by weight of resin, other additives such as stabilizers may be 0 to 20 parts by weight, preferably 1 to 15 parts by weight.

[0109] The stabilizer may be, for example, a calcium-zinc (Ca-Zn) stabilizer, such as a calcium-zinc stearate, or a barium-zinc (Ba-Zn) stabilizer, but is not particularly limited thereto.

[0110] As mentioned above, resin compositions can be used in both melt processing and plastisol processing. For example, they can be used in automotive color processing, extrusion processing, or injection processing as melt processing, and in coating processing or similar processes as plastisol processing.

[0111] [Example]

[0112] The present invention will now be described in detail with reference to embodiments. However, embodiments of the present invention may be modified into various other forms, and the scope of the present invention should not be construed as limited to the embodiments described below. Embodiments of the present invention are provided to provide a more complete explanation of the invention to those skilled in the art.

[0113] [Example] [1] []

[0114] 1.5 g of catalyst (TnBT), 500 g of waste polyethylene terephthalate (PET), and 1220 g of 2-ethylhexanol were added to a reactor equipped with a stirrer, condenser, and decanter. The transesterification reaction was then carried out at a reaction temperature of 150°C to 230°C under a nitrogen atmosphere for 3 to 8 hours. After the reaction was complete, unreacted 2-ethylhexanol was removed under reduced pressure. Through the above procedure, a composition containing 0.2 wt% 2-hydroxyethyl(2-ethylhexyl) PET and 97.5 wt% di(2-ethylhexyl) PET (DEHTP) was obtained. The composition did not contain any residual components, including byproducts and intermediates generated during the reaction process.

[0115] Subsequently, 1000 g of the above-obtained reactants and 190 g of n-butanol (equivalent to 19 parts by weight based on 100 parts by weight of reactants) were added, and the mixture was subjected to transesterification at a reaction temperature of 160°C under a nitrogen atmosphere for 2 hours. Then, through a purification process, an ester-based plasticizer composition was finally obtained, comprising 0.9 wt% of 2-ethylhexyl (2-hydroxyethyl) p-phthalate, 5.3 wt% of di(n-butyl) p-phthalate, 38.2 wt% of (n-butyl)(2-ethylhexyl) p-phthalate, and 53.9 wt% di(2-ethylhexyl) p-phthalate. The composition does not contain residual components of the above four components, such as dimer compounds and byproducts generated during the reaction process, and the content of byproducts is shown in Table 1 below.

[0116] [Example] [2] []

[0117] By controlling the input amount of 2-ethylhexanol and the reaction time, an ester-based plasticizer composition comprising 8.6 wt% 2-hydroxyethyl(2-ethylhexyl) p-phthalate, 3.8 wt% di(n-butyl) p-phthalate, 34.1 wt% (n-butyl)(2-ethylhexyl) p-phthalate, and 50.2 wt% di(2-ethylhexyl) p-phthalate was obtained in the same manner as in Example 1. The composition does not contain residual components of the above four components, such as dimer compounds or byproducts generated during the reaction process, and the content of these byproducts is shown in Table 1 below. [] []

[0118] [Example] [3] []

[0119] By controlling the input amount of 2-ethylhexanol and the reaction time, an ester-based plasticizer composition comprising 19.4 wt% of 2-hydroxyethyl(2-ethylhexyl) p-phthalate, 1.9 wt% of di(n-butyl) p-phthalate, 28.7 wt% of (n-butyl)(2-ethylhexyl) p-phthalate, and 45.3 wt% of di(2-ethylhexyl) p-phthalate was obtained in the same manner as in Example 1. The composition does not contain residual components of the above four components, such as dimer compounds or byproducts generated during the reaction process, and the content of these byproducts is shown in Table 1 below.

[0120] [Reference Example]

[0121] 1.5 g of catalyst (TnBT), 500 g of waste polyethylene terephthalate (PET), and 1220 g of 2-ethylhexanol were added to a reactor equipped with a stirrer, condenser, and decanter. The transesterification reaction was then carried out at a reaction temperature of 150°C to 230°C under a nitrogen atmosphere for 8 hours. After the reaction was complete, unreacted 2-ethylhexanol was removed by vacuum decompression. Subsequently, 100 g of a 3 wt% sodium hydroxide aqueous solution was added to neutralize the catalyst, and a small amount of unreacted 2-ethylhexanol was removed by distillation. Through the above procedure, all 2-hydroxyethyl(2-ethylhexyl) PET was removed from the composition, yielding a composition containing 99.9 wt% di(2-ethylhexyl) PET (DEHTP).

[0122] [Comparative Example] [1] []

[0123] By controlling the input amount of 2-ethylhexanol and the reaction time, an ester-based plasticizer composition containing 5.9 wt% of di(n-butyl) p-phthalate, 39.2 wt% of (n-butyl)(2-ethylhexyl) p-phthalate, and 54.9 wt% of di(2-ethylhexyl) p-phthalate was obtained in the same manner as in Example 1, after all 2-hydroxyethyl(2-ethylhexyl) p-phthalate was removed from the composition.

[0124] [Comparative Example] [2] []

[0125] By controlling the input amount of 2-ethylhexanol and the reaction time, an ester-based plasticizer composition comprising 22.5 wt% of 2-hydroxyethyl(2-ethylhexyl) p-phthalate, 1.7 wt% of di(n-butyl) p-phthalate, 26.7 wt% of (n-butyl)(2-ethylhexyl) p-phthalate, and 41.2 wt% of di(2-ethylhexyl) p-phthalate was obtained in the same manner as in Example 1. The composition does not contain residual components of the above four components, such as dimer compounds, or byproducts generated during the reaction process, and the content of these byproducts is shown in Table 1 below.

[0126]

[0127] [Experimental Example] [1] Evaluation of Thin-Layer Performance

[0128] Using plasticizers from the examples and comparative examples, the samples were manufactured according to ASTM D638 under the following formulation and manufacturing conditions.

[0129] [(1)] [Formula:] 100 parts by weight of linear vinyl chloride polymer (LS100), 50 parts by weight of plasticizer, and 3 parts by weight of stabilizer (BZ-153T)

[0130] [(2)] [Blending:] Mix at 700 rpm at 98°C

[0131] [(3)] [Sample Manufacturing:] 1T to 3T sheets were manufactured by treating the sheets with a roller mill at 160°C for 4 minutes and with a press at 180°C for 2.5 minutes (low pressure) and 2 minutes (high pressure).

[0132] [(4)] [Evaluation Items]

[0133] 1) Hardness: Using ASTM D2240, the Shore hardness (Shore "A" and / or Shore "D") is measured at 25°C with a 3T specimen for 10 seconds. The smaller the value, the better the plasticizing efficiency.

[0134] 2) Tensile strength: Using the ASTM D638 method, a 1T specimen was stretched using a UTM testing apparatus (manufacturer: Instron, model: 4466) at a crosshead speed of 200 mm / min, and the time point at which the 1T specimen fractured was measured. The tensile strength was calculated as follows.

[0135] Tensile strength (kgf / cm²) = Load (kgf) / Thickness (cm) x Width (cm)

[0136] 3) Elongation Measurement: Using the ASTM D638 method, a 1T specimen was stretched using a UTM at a crosshead speed of 200 mm / min, and the time of fracture of the 1T specimen was measured. The elongation was calculated as follows:

[0137] Elongation (%) = Length after elongation / Initial length x 100

[0138] 4) Measurement of Tensile Strength and Elongation Residue: The measurement of tensile strength and elongation residue is used to measure the tensile strength and elongation remaining in the specimen after being heated to 100°C for 168 hours, and the measurement method is the same as that for tensile strength and elongation.

[0139] 5) Measurement of migration loss: This measurement was performed according to KSM-3156. Specifically, a test specimen with a thickness of 1 mm was obtained, and absorbent sheets that could move to both sides of the test specimen to absorb organic material discharged to the surface of the test specimen were added. Then, a plate covering the entire test specimen was attached to it to apply a load of 1 kgf / cm². The test specimen was placed in a hot air circulating oven (80°C) for 72 hours, then removed from the oven and cooled to room temperature for 4 hours. Afterward, the plate and the absorbent sheets attached to both sides of the test specimen were removed, and the weight of the specimen was measured before and after it remained in the oven to calculate the migration loss using Equation 3 below.

[0140] Migration loss (%) = {(Initial weight of the sample at room temperature - Weight of the sample after standing in the oven) / Initial weight of the sample at room temperature} x 100

[0141] 6) Measurement of evaporation loss: After treating the prepared sample at 80°C for 72 hours, measure the weight of the sample.

[0142] Volatilization loss (wt%) = Initial sample weight - (Sample weight after 72 hours of treatment at 80°C) / Initial sample weight x 100

[0143] 7) Stress test (stress resistance): A 2 mm thick sample is bent and left to stand at 23°C for 168 hours. The degree of migration (leakage) is then observed on the first, third, and seventh days, and the results are described numerically. The closer the value is to 0, the better the stress resistance.

[0144] 8) Measurement of absorption rate: Processability was evaluated by measuring the time taken to mix the resin and plasticizer with each other using a planetary mixer (Brabender, P600) until the torque of the mixer stabilized under conditions of 73°C and 60 rpm.

[0145] [(5)] [Evaluation Results]

[0146] The project evaluation results are shown in Tables 2 and 3 below.

[0147]

[0148]

[0149] Referring to Tables 2 and 3 above, compared with the reference examples of ready-made phthalic acid di(2-ethylhexyl) ester-based plasticizer compositions, Examples 1 to 3 use waste PET as raw material, thus being environmentally friendly and reducing manufacturing costs. Furthermore, even with the presence of byproducts, Examples 1 to 3 still exhibit excellent results in terms of mechanical properties, migration loss, absorption rate, and stress resistance. This means that the plasticizer composition of the present invention, when used together with 2-ethylhexyl (2-hydroxyethyl) phthalic acid and byproducts comprising one or more of formulas 1 to 5, exhibits improvements in stress resistance, migration loss, absorption rate, and mechanical properties without deterioration of existing physical properties. Typically, in the case of a composition that combines two components, the effect of the combined composition is exhibited in the direction of reduced effectiveness of each component. However, conversely, in the present invention, improvements in stress resistance and mechanical properties are achieved while maintaining physical properties at the same level as existing ones. This confirms that the present invention achieves effects that the prior art could not predict.

[0150] Meanwhile, in Comparative Example 1, by adjusting the input amount of 2-ethylhexanol and the reaction time, 2-ethylhexyl (2-hydroxyethyl) phthalate was completely removed from the final composition. The manufacturing process cost was higher than in Examples 1 to 3, but the physical properties of the final plasticizer composition were similar to those of the plasticizer compositions in Examples 1 to 3. In particular, the volatility loss, migration resistance, stress resistance, and mechanical properties were inferior to those of the examples. From the above, it can be confirmed that the plasticizer composition of the present invention has a lower manufacturing cost than typical plasticizer compositions containing di(n-butyl) phthalate, (n-butyl)(2-ethylhexyl) phthalate, and di(2-ethylhexyl) phthalate recovered from polyethylene terephthalate, while also exhibiting excellent functionality.

[0151] Meanwhile, Comparative Example 2 was prepared from polyethylene terephthalate in a manner similar to the embodiments of the present invention by controlling the input amount of 2-ethylhexanol and the reaction time. It was a plasticizer composition containing an excess of 2-ethylhexyl (2-hydroxyethyl) terephthalate and / or byproducts of the dimer compound according to the present invention. Although the plasticizing efficiency was similar to Examples 1 to 3, the results showed that the mechanical properties and stress resistance were inferior to the aforementioned examples. Specifically, the results showed that in terms of mechanical properties, its elongation residue was significantly inferior to that of Examples 1 to 3. From the above, it can be confirmed that the plasticizer composition of the present invention, which limits the content of each compound to maximize the improvement of various physical properties such as mechanical properties, stress resistance, heat resistance, and migration resistance, exhibits superior plasticizer function compared to the plasticizer of Comparative Example 2, which contains an excess of 2-ethylhexyl (2-hydroxyethyl) terephthalate and / or byproducts of the dimer compound.

Claims

1. A plasticizer composition comprising 2-ethylhexyl(2-hydroxyethyl) terephthalate, di(n-butyl) terephthalate, (n-butyl)(2-ethylhexyl) terephthalate, and di(2-ethylhexyl) terephthalate, wherein, The content of 2-ethylhexyl (2-hydroxyethyl) p-phthalate, based on the total plasticizer composition, is from 0.01 wt% to 20 wt%, wherein the total weight of di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate, based on the total weight of the plasticizer composition, is from 75.9 to 97.4 wt%. Based on the combined weight of di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate in the plasticizer composition, it includes 0.1 wt% to 20 wt% of di(n-butyl) p-phthalate, 5 wt% to 50 wt% of (n-butyl)(2-ethylhexyl) p-phthalate, and 30 wt% to 90 wt%. Di(2-ethylhexyl) p-phthaloate in wt%.

2. The plasticizer composition as claimed in claim 1, wherein, The content of 2-ethylhexyl(2-hydroxyethyl) phthalate is from 0.01 wt% to 15 wt%.

3. The plasticizer composition of claim 1 further comprises n-butyl (2-hydroxyethyl) p-phthalate.

4. The plasticizer composition of claim 1 further comprises di(n-butyl) isophthalate, (n-butyl)(2-ethylhexyl) isophthalate, and di(2-ethylhexyl) isophthalate.

5. The plasticizer composition of claim 1 further comprises byproducts including any one or more of the dimer compounds represented by formulas 1 to 5:

6. The plasticizer composition as claimed in claim 5, wherein, The total content of this byproduct in the composition is from 0.1 wt% to 5.0 wt%.

7. The plasticizer composition as claimed in claim 5, wherein, The weight ratio of the byproduct in the composition to 2-ethylhexyl (2-hydroxyethyl) phthalate is 1:1 to 10.

8. The plasticizer composition as claimed in claim 5, wherein, The weight ratio of the byproduct in the composition to the total content of di(n-butyl) p-phthalate, (n-butyl)(2-ethylhexyl) p-phthalate, and di(2-ethylhexyl) p-phthalate is from 1:20.0 to 150.

0.

9. A method for preparing a plasticizer composition as claimed in claim 1, the method comprising the steps of: mixing polyethylene terephthalate and 2-ethylhexanol in the presence of a catalyst to carry out a transesterification reaction; and adding n-butanol to the reactants to carry out a transesterification reaction, wherein, Based on the total content of PET and 2-ethylhexanol, it contains 80 wt% or less of polyethylene terephthalate, wherein the transesterification reaction is carried out at a reaction temperature of 120°C to 240°C for 10 minutes to 12 hours.

10. As in request item 9, wherein, Poly(p-phthalic acid) is mixed in a total amount of 80 wt% or less relative to the total content of polyethylene terephthalate and 2-ethylhexanol.

11. As in request item 9, wherein, Poly(p-phthalic acid) is mixed in an amount where the total content of polyethylene terephthalate and 2-ethylhexanol is 60 wt% or less.

12. As in request item 9, wherein, Poly(p-phthalate) contains waste and recycled polyethylene terephthalate.

13. A resin composition comprising: 100 parts by weight of a resin; and 5 to 150 parts by weight of a plasticizer composition as claimed in claim 1.

14. The resin composition as claimed in claim 13, wherein, The resin is selected from one or more of the following groups: straight vinyl chloride polymer, paste vinyl chloride polymer, ethylene-vinyl acetate copolymer, ethylene polymer, propylene polymer, polyketone, polystyrene, polyurethane, polylactic acid, natural rubber, and synthetic rubber.

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