Plasticizer composition and resin composition containing same

Abstract

The present invention relates to 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 the 2-ethylhexyl(2-hydroxyethyl)terephthalate is 20% by weight or less based on the total weight of the plasticizer composition, and the plasticizer composition can improve mechanical properties, migration resistance, and weight loss properties when applied to a resin.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0024956, filed on February 25, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a plasticizer composition containing 2-ethylhexyl(2-hydroxyethyl)terephthalate, di(n-butyl)terephthalate, (n-butyl)(2-ethylhexyl)terephthalate, and di(2-ethylhexyl)terephthalate, and a resin composition containing the same. [Background technology]

[0003] Plasticizers are usually prepared by reacting alcohol with polycarboxylic acids such as phthalic acid and adipic acid to form the corresponding esters. In addition, in view of domestic and international regulations on phthalate-based plasticizers, which are harmful to the human body, research is ongoing into plasticizer compositions that can replace phthalate-based plasticizers, such as terephthalate-based, adipate-based, and other polymer-based plasticizers.

[0004] Meanwhile, the need for such environmentally friendly products is increasing in the plastisol industry, calendar industry, and extrusion / injection compound industry, which manufacture finished products such as flooring, wallpaper, soft and hard sheets, gloves, electric wires, hoses, and films. In order to enhance the quality characteristics, processability, and productivity of each finished product, appropriate plasticizers must be used taking into consideration discoloration, migration, mechanical properties, etc.

[0005] Depending on the characteristics required for each industry in these various areas of use, such as tensile strength, elongation, light resistance, migration, gelling properties, and absorption speed, PVC resin is mixed with secondary materials such as plasticizers, fillers, stabilizers, viscosity reducers, dispersants, defoamers, and foaming agents.

[0006] For example, when di(2-ethylhexyl) terephthalate (DEHTP), which is relatively inexpensive and is the most widely used plasticizer composition applicable to PVC, is applied, the hardness or sol viscosity is high, the absorption rate of the plasticizer is relatively slow, and the migration property and stress migration property are not good.

[0007] One possible solution to this problem is to use the product of a transesterification reaction with butanol as a plasticizer in a composition containing DEHTP. However, while this improves the plasticization efficiency, it also results in a slight decrease in mechanical properties and the chronic problem of the plasticizer leaking out due to heat or physical forces.

[0008] Moreover, in recent years, ensuring environmental friendliness has become extremely important. This means that not only is the final product itself environmentally friendly, but the supply and demand of raw materials and ensuring the environmental friendliness of processes are also very important in industry. However, due to a conflict of interest with the primary challenge in industry, which is to ensure cost competitiveness, there is a need to develop products that are environmentally friendly in terms of raw materials, manufacturing processes, and final products, as well as being cost competitive. Summary of the Invention Problem that the invention aims to solve

[0009] The present invention aims to provide a plasticizer composition that has performance equal to or better than that of conventional phthalate-based plasticizers, is free from reproductive and developmental toxicity, and is environmentally friendly, by applying a composition obtained by subjecting 2-ethylhexyl(2-hydroxyethyl)terephthalate and di(2-ethylhexyl)terephthalate, which are obtained during the decomposition of polyethylene terephthalate, to a transesterification reaction with n-butanol.

[0010] Another object of the present invention is to provide a method for producing a plasticizer composition, which is economical and environmentally friendly and has excellent physical properties, by using discarded polyethylene terephthalate as a raw material. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention provides a plasticizer composition, a method for producing the same, and a resin composition containing the plasticizer composition. (1) The present invention provides 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 the 2-ethylhexyl(2-hydroxyethyl)terephthalate is 20% by weight or less based on the total weight of the plasticizer composition.

[0012] (2) In the present invention, there is provided the plasticizer composition according to (1) above, in which the content of the 2-ethylhexyl (2-hydroxyethyl) terephthalate is 0.01 to 15% by weight.

[0013] (3) The present invention provides the plasticizer composition according to (1) or (2) above, further comprising n-butyl (2-hydroxyethyl) terephthalate.

[0014] (4) The present invention provides the plasticizer composition according to any one of (1) to (3) above, further comprising di(n-butyl)isophthalate, (n-butyl)(2-ethylhexyl)isophthalate, and di(2-ethylhexyl)isophthalate.

[0015] (5) The present invention provides the plasticizer composition according to any one of (1) to (4) above, further comprising a by-product containing one or more dimer compounds represented by the following chemical formulas 1 to 5:

[0016] [ka]

[0017] [ka]

[0018] [ka]

[0019] [ka]

[0020] [ka]

[0021] (6) The present invention provides the plasticizer composition according to (5) above, wherein the total content of the by-products in the composition is 0.1 to 5.0% by weight.

[0022] (7) The present invention provides the plasticizer composition according to (5) or (6) above, wherein the weight ratio of the by-product to 2-ethylhexyl (2-hydroxyethyl) terephthalate in the composition is 1:1-10.

[0023] (8) The present invention provides the plasticizer composition according to any one of (5) to (7) above, wherein a weight ratio of the by-product to a total content of di(n-butyl) terephthalate, (n-butyl)(2-ethylhexyl) terephthalate, and di(2-ethylhexyl) terephthalate in the composition is 1:20.0 to 150.0.

[0024] (9) The present invention provides a method for producing the plasticizer composition according to any one of (1) to (8) above, comprising a step of mixing polyethylene terephthalate and 2-ethylhexanol in the presence of a catalyst to cause an esterification reaction, wherein a product of the esterification reaction includes 2-ethylhexyl(2-hydroxyethyl)terephthalate and di(2-ethylhexyl)terephthalate.

[0025] (10) In the present invention, there is provided the method according to (9) above, wherein the polyethylene terephthalate is mixed in an amount of 80% by weight or less based on the total content of polyethylene terephthalate and 2-ethylhexanol.

[0026] (11) In the present invention, there is provided the method according to (9) or (10) above, wherein the polyethylene terephthalate is mixed in an amount of 60% by weight or less based on the total content of the polyethylene terephthalate and 2-ethylhexanol.

[0027] (12) In the present invention, there is provided the method according to any one of (9) to (11) above, wherein the polyethylene terephthalate includes discarded and recycled polyethylene terephthalate.

[0028] (13) The present invention provides a resin composition comprising 100 parts by weight of a resin and 5 to 150 parts by weight of the plasticizer composition according to any one of (1) to (8) above.

[0029] (14) In the present invention, there is provided the resin composition according to (13) above, wherein the resin is at least one selected from the group consisting of 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. Effect of the Invention

[0030] The plasticizer composition according to one embodiment of the present invention is an environmentally friendly substance with no reproductive or developmental toxicity, and when used in a resin composition, it can improve mechanical properties, migration resistance, stress migration, and absorption rate compared to conventional plasticizers. Such a top-down manufacturing method utilizes waste materials, making it an environmentally friendly manufacturing method and highly cost-competitive. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The terms and words used in this specification and the claims should not be interpreted in a limited manner to their ordinary or dictionary meanings, but should be interpreted in a manner that is consistent with the technical idea of ​​the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best describe their invention.

[0032] Definition of Terms The term "composition" as used herein includes mixtures of materials which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0033] As used herein, "straight vinyl chloride polymer" is a type of vinyl chloride polymer, which is polymerized by suspension polymerization or bulk polymerization, etc. This polymer is a porous particle having multiple pores, has a size of tens to hundreds of micrometers, does not aggregate, and has excellent flowability.

[0034] As used herein, a "paste vinyl chloride polymer" is a type of vinyl chloride polymer, which is polymerized by microsuspension polymerization, microseed polymerization, emulsion polymerization, etc. This polymer is a fine, dense particle without voids, has a size of tens to thousands of nanometers, has a tendency to aggregate, and has poor flowability.

[0035] The terms "comprise", "have" and their derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether these are specifically disclosed or not. To avoid any uncertainty, all compositions claimed using the term "comprise" may include any additional additives, adjuvants, or compounds, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term "consisting essentially of" excludes from the scope of any running description any other component, step, or procedure, except those that are not essential to operability. The term "consisting of" excludes any component, step, or procedure not specifically described or listed.

[0036] Measurement method In this specification, the content analysis of the components in the composition is performed by gas chromatography measurement, and analysis is performed using a gas chromatography device manufactured by Agilent (product name: Agilent 7890 GC, column: HP-5, carrier gas: helium (flow rate 2.4 mL / min), detector: FID, injection amount: 1 uL, initial value: 70°C / 4.2 min, final value: 280°C / 7.8 min, program rate: 15°C / min).

[0037] In this specification, "hardness" refers to the Shore hardness (Shore "A" and / or Shore "D") at 25°C in accordance with ASTM D2240, measured under conditions of 3T 10s, and can be an index for evaluating the plasticization efficiency, with a lower hardness indicating a more excellent plasticization efficiency.

[0038] In this specification, the "tensile strength" is calculated according to the ASTM D638 method by measuring the point at which a test piece breaks after pulling it at a cross head speed of 200 mm / min (1T) using a UTM test device (manufacturer: Instron, model name: 4466) and calculating according to the following formula 1.

[0039] [Formula 1] Tensile strength (kgf / cm 2 ) = Load value (kgf) / thickness (cm) x width (cm)

[0040] In this specification, the "elongation rate" is calculated according to the following formula 2, after pulling a test piece at a cross head speed of 200 mm / min (1T) using the UTM in accordance with ASTM D638, the point at which the test piece breaks is measured.

[0041] [Formula 2] Elongation rate (%) = length after elongation / initial length x 100

[0042] In this specification, the "migration loss" can be measured according to KSM-3156. Specifically, a test piece having a thickness of 1 mm is obtained, absorbent paper capable of absorbing organic matter that migrates and flows out onto the surface is attached to both sides of the test piece, and then a plate capable of covering the entire test piece is attached on top of the absorbent paper, and the test piece is subjected to a pressure of 1 kgf / cm. 2 A load of 10 ...

[0043] [Formula 3] Migration loss (%) = {[(initial weight of test piece) - (weight of test piece after leaving in oven)] / (initial weight of test piece)} x 100

[0044] In this specification, the "volatile loss" is measured by measuring the weight of a test piece after working the test piece at 80°C for 72 hours.

[0045] [Formula 4] Heat loss (%) = {[(initial weight of test piece) - (weight of test piece after processing)] / (initial weight of test piece)} x 100

[0046] In the case of the various measurement conditions described above, the detailed conditions such as temperature, rotation speed, time, etc. may vary slightly depending on the case, and in such a case, the measurement method and conditions will be specified separately.

[0047] In this specification, the "absorption rate" is evaluated by measuring the time it takes for the resin and the plasticizer to be mixed together using a planetary mixer (Brabender, P600) at 77°C and 60 rpm until the torque of the mixer stabilizes.

[0048] In the case of the various measurement conditions described above, the detailed conditions such as temperature, rotation speed, time, etc. may vary slightly depending on the case, and in such a case, the measurement method and conditions will be specified separately. The present invention will now be described in more detail to aid in understanding the invention.

[0049] Plasticizer Composition The present invention provides 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 the 2-ethylhexyl(2-hydroxyethyl)terephthalate is 20% by weight or less based on the total weight of the plasticizer composition.

[0050] The plasticizer composition containing 2-ethylhexyl(2-hydroxyethyl)terephthalate and di(2-ethylhexyl)terephthalate is obtained by transesterifying polyethylene terephthalate (hereinafter, referred to as PET) with 2-ethylhexanol, and then transesterifying the resulting product with n-butanol.

[0051] Generally, PET and 2-ethylhexanol are reacted to obtain di(2-ethylhexyl)terephthalate, which is used as a conventional plasticizer. However, this produces a large amount of by-products, and in the case of bis(2-hydroxyethyl)terephthalate and 2-ethylhexyl(2-hydroxyethyl)terephthalate produced during the reaction, it is difficult to separate the product from di(2-ethylhexyl)terephthalate. In addition, since bis(2-hydroxyethyl)terephthalate and 2-ethylhexyl(2-hydroxyethyl)terephthalate are alcohol-based compounds containing a hydroxyl group in their molecular structure, there is another problem that they may cause a side reaction with the target product, di(2-ethylhexyl)terephthalate. Therefore, almost all manufacturers use the direct esterification reaction of terephthalic acid and 2-ethylhexanol or the transesterification reaction of dimethyl terephthalate and 2-ethylhexanol to produce di(2-ethylhexyl)terephthalate, and there is no established method to use PET as a raw material.

[0052] However, the present invention has focused on the function of 2-ethylhexyl (2-hydroxyethyl) terephthalate, which was previously targeted for removal as an impurity, and instead of removing it, has confirmed that it is possible to provide a plasticizer composition with improved performance compared to conventional plasticizer products by including it in a certain amount in the plasticizer composition. 2-Ethylhexyl (2-hydroxyethyl) terephthalate is not easily separated from di(2-ethylhexyl) terephthalate, but it functions to solve the problem of pressure migration of di(2-ethylhexyl) terephthalate, that is, the problem of plasticizer leakage due to heat or pressure. In particular, 2-ethylhexyl (2-hydroxyethyl) terephthalate can be more firmly bonded to the resin to be mixed due to the presence of a hydroxyl group in the molecular structure, and can play a role in holding di(2-ethylhexyl) terephthalate, the main component of the plasticizer composition, so that it is not discharged outside the resin.

[0053] Furthermore, the plasticizer composition of the present invention is obtained by again transesterifying the product obtained as a result of the reaction of PET with 2-ethylhexanol with n-butanol, and contains a compound in which at least one 2-ethylhexyl group of the previously obtained di(2-ethylhexyl)terephthalate is replaced with an n-butyl group, more specifically, di(n-butyl)terephthalate and (n-butyl)(2-ethylhexyl)terephthalate. The two components complement the plasticizing efficiency of di(2-ethylhexyl)terephthalate and ethylhexyl(2-hydroxyethyl)terephthalate in the plasticizer composition, and can further improve the plasticizing efficiency of the entire plasticizer composition.

[0054] Based on the total weight of di(n-butyl) terephthalate, (n-butyl)(2-ethylhexyl) terephthalate, and di(2-ethylhexyl) terephthalate in the plasticizer composition, the composition may contain 0.1 to 20 wt% di(n-butyl) terephthalate, 5 to 50 wt% (n-butyl)(2-ethylhexyl) terephthalate, and 30 to 90 wt% di(2-ethylhexyl) terephthalate. When the weight percentage of each component is within the above-mentioned range, the composition can have excellent overall physical properties and an excellent balance between the physical properties.

[0055] According to one embodiment of the present invention, the content of the 2-ethylhexyl (2-hydroxyethyl) terephthalate may be 20% by weight or less based on the entire plasticizer composition. Exemplarily, the content of the 2-ethylhexyl (2-hydroxyethyl) terephthalate is 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, 6.0 wt % or more, 6.5 wt % or more, 7.0 wt % or more, 7.1 wt % or more, 7.2 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, or 16.0 wt % or less. , 15.0% by weight or less, 14.9% by weight or less, 14.5% by weight or less, 13.0% by weight or less, 12.8% by weight or less, 12.5% ​​by weight or less, 12.4% by weight or less, 12.0% by weight or less Bottom, 11.7% by weight or less, 11.5% by weight or less, 11.3% by weight or less, 11.0% by weight or less, 10.5% by weight or less, 10.0% by weight or less, 9.5% by weight or less, 9.3% by weight or less, It may be 8.0% by weight or less, 8.6% by weight or less, 8.5% by weight or less, 8.0% by weight or less, 7.5% by weight or less, 7.2% by weight or less, 7.0% by weight or less, 6.5% by weight or less, 6.0% by weight or less, 5.5% by weight or less, 5.0% by weight or less, 4.5% by weight or less, 4.0% by weight or less, 3.5% by weight or less, 3.0% by weight or less, 2.5% by weight or less, or 2.0% by weight or less. Preferably, the content of terephthalate may be 1.0 to 20% by weight based on the entire plasticizer composition. In addition, the weight ratio of the 2-ethylhexyl (2-hydroxyethyl) terephthalate to di(2-ethylhexyl) terephthalate may be 1:3.5 to 10,000, preferably 1:3.5 to 1000, and more preferably 1:3.5 to 100.If the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate in the plasticizer composition is too low, the effect of improving the migration resistance of 2-ethylhexyl (2-hydroxyethyl) terephthalate is insignificant, and conversely, if the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate is too high, the content of di(2-ethylhexyl) terephthalate is relatively low, resulting in poor heat loss and an excessively fast absorption rate, which makes the blending with resin and the process conditions of the finished product unstable, and thus the heat resistance of the overall resin composition or the finished product obtained from the resin composition may be reduced. In particular, if the 2-ethylhexyl (2-hydroxyethyl) terephthalate is included as a major component in the plasticizer composition, the relatively low molecular weight of 2-ethylhexyl (2-hydroxyethyl) terephthalate makes it difficult to blend with the resin, and problems such as rolling after blending may occur. When the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate satisfies the above-mentioned preferred range, suitable heat loss and absorption speed can be realized, and therefore a plasticizer composition that has excellent heat resistance and can be stably blended into a resin composition can be provided.

[0056] The plasticizer composition of the present invention may further include n-butyl(2-hydroxyethyl)terephthalate in addition to the above-mentioned components. 2-Ethylhexyl(2-hydroxyethyl)terephthalate formed as a result of the transesterification reaction between PET and 2-ethylhexanol may react with n-butanol added thereafter, similarly to di(2-ethylhexyl)terephthalate, and the 2-ethylhexyl group of 2-ethylhexyl(2-hydroxyethyl)terephthalate may be substituted with an n-butyl group, so that n-butyl(2-hydroxyethyl)terephthalate may be included in the plasticizer composition. The n-butyl(2-hydroxyethyl)terephthalate may achieve the same function as the above-mentioned 2-ethylhexyl(2-hydroxyethyl)terephthalate, and may be included in an amount of 20% by weight or less, 15% by weight or less, 10% by weight or less, or 5% by weight or less based on the total content of the plasticizer composition.

[0057] In addition to the above-mentioned components, the plasticizer composition of the present invention may further contain di(n-butyl)isophthalate, (n-butyl)(2-ethylhexyl)isophthalate, and di(2-ethylhexyl)isophthalate.

[0058] Polyethylene terephthalate contains a small amount of isophthalate, which is an isomer of terephthalate, in its molecular structure, and this isophthalate structure can form the di(n-butyl)isophthalate, (n-butyl)(2-ethylhexyl)isophthalate, and di(2-ethylhexyl)isophthalate through the above-mentioned series of transesterification reaction processes. In the conventional reaction process for recovering di(2-ethylhexyl)terephthalate from PET, such isophthalate-based components are considered as impurities and are completely removed from the final composition, but in the present invention, when the above-mentioned isophthalate-based components are partially contained in the plasticizer composition, it is possible to achieve better physical properties than when terephthalate is used alone, and to maintain a balance of physical properties. Therefore, the plasticizer composition of the present invention may further contain di(n-butyl)isophthalate, (n-butyl)(2-ethylhexyl)isophthalate, and di(2-ethylhexyl)isophthalate.

[0059] Since the content of isophthalate in the reaction raw material PET is low, the content of isophthalate-based components in the plasticizer composition of the present invention obtained from PET is also at a low level, and specifically, the total content of the above three components may be 5% by weight or less, preferably 0.3 to 3% by weight, based on the entire composition. It is not easy to increase the content of the isophthalate-based components above the above-mentioned range due to the structure of the reaction raw material PET, and when the content of the isophthalate-based components is lower than the above-mentioned range, the improvement effect obtained by including the isophthalate-based components is insignificant.

[0060] On the other hand, when the plasticizer composition further contains di(n-butyl)isophthalate, (n-butyl)(2-ethylhexyl)isophthalate, and di(2-ethylhexyl)isophthalate, the above-mentioned percentage contents of di(n-butyl)terephthalate, (n-butyl)(2-ethylhexyl)terephthalate, and di(2-ethylhexyl)terephthalate can be similarly applied to the percentage contents therebetween.

[0061] According to one embodiment of the present invention, the plasticizer composition of the present invention may further include a by-product containing any one or more of the dimer compounds represented by the following chemical formulas 1 to 5.

[0062] [ka]

[0063] [ka]

[0064] [ka]

[0065] [ka]

[0066] [ka]

[0067] In the present invention, it has been confirmed that a plasticizer composition with improved performance compared to conventional plasticizer products can be provided by controlling the content of a dimer compound with a (terephthalate or isophthalate)-(ethylene glycol)-(terephthalate or isophthalate) structure, which is one of the by-products, such as the above-mentioned 2-ethylhexyl(2-hydroxyethyl)terephthalate, in the plasticizer composition to be constant. Polyethylene terephthalate contains a small amount of isophthalate, an isomer of terephthalate, in its molecular structure, and this isophthalate structure can be produced as a dimer compound containing the isophthalate through the above-mentioned series of transesterification reaction processes.

[0068] The dimer compound contained in the by-product can be produced in various forms and contents depending on the type of alcohol used and the reaction conditions in the depolymerization process of PET. When a compound having such a structure is contained in the plasticizer composition together with a terephthalate-based plasticizer, it can complement the compression migration of the conventional terephthalate-based plasticizer.

[0069] For example, in the process of synthesizing the monomer di(2-ethylhexyl)terephthalate by the reaction of 2-ethylhexanol with PET, a dimer compound in which 2-ethylhexanol is bonded to each end of two terephthalic acids may be produced, and such a dimer compound may be included in the final plasticizer composition.

[0070] The above-mentioned process for forming the dimer compound is only one example. In addition to the above-mentioned process, various combinations of dimer compounds can be formed by various reactions between di(2-hydroxyethyl)terephthalate, 2-ethylhexyl(2-hydroxyethyl)terephthalate, and 2-ethylhexyl(2-hydroxyethyl)isophthalate.

[0071] In addition, the transesterification reaction may be intentionally controlled during the above-mentioned preparation method to control the contents of the di(2-ethylhexyl) terephthalate, 2-ethylhexyl(2-hydroxyethyl) and dimer compounds. Meanwhile, the by-product may further include trimer and / or tetramer compounds in addition to the dimer compounds. When the reaction time is controlled during the transesterification reaction, not only the dimer compounds but also the trimer and / or tetramer compounds may be relatively produced in large amounts depending on the reaction time. The by-products maintain the final processing properties of the entire plasticizer composition of di(2-ethylhexyl) terephthalate and 2-ethylhexyl(2-hydroxyethyl) terephthalate at a usable level without deteriorating the above-mentioned properties, so that the reaction product containing the by-products may be used as the plasticizer composition as it is.

[0072] In addition, the content of the by-products can be determined depending on the amount of catalyst used in the preparation method, the amounts of 2-ethylhexanol and n-butanol added, the reaction pressure and temperature, the reaction progress time, etc. In particular, as the amount of n-butanol added increases, the n-butanol breaks the bonds of the dimer compounds in the by-products and is converted to (n-butyl)(2-ethylhexyl) terephthalate and di(n-butyl) terephthalate, so that the content of (n-butyl)(2-ethylhexyl) terephthalate and di(n-butyl) terephthalate increases, but the content of the dimer compounds and by-products containing the same can decrease. In the plasticizer composition provided by the present invention, the total content of the by-products including the dimer compound in the composition may be 0.1 to 5.0% by weight, and for example, the total content of the dimer compound in the composition may be 0.1% by weight or more, 0.2% by weight or more, 0.3% by weight or more, 0.5% by weight or more, 0.8% by weight or more, 1.0% by weight or more, 1.2% by weight or more, 1.5% by weight or more, 5.0% by weight or less, 4.5% by weight or less, 4.0% by weight or less, 3.5% by weight or less, 3.2% by weight or less, 3.1% by weight or less, 3.0% by weight or less, 2.7% by weight or less, 2.5% by weight or less, 2.3% by weight or less, 2.0% by weight or less, or 1.7% by weight or less. Preferably, the total content of the by-products in the composition may be 0.5 to 3.5% by weight. When the content of the by-products is controlled within the above-mentioned range, it is possible to provide a plasticizer composition having plasticizer efficiency characteristics equal to or greater than those of conventional plasticizer products, and excellent mechanical properties such as tensile strength and tensile retention, migration loss, absorption rate, and stress resistance characteristics.

[0073] The weight ratio of the by-product to 2-ethylhexyl (2-hydroxyethyl) terephthalate in the composition may be 1:1 to 10, and may be, for example, 1:1.0 or more, 1.2 or more, 1.5 or more, 1.7 or more, 2.0 or more, 2.5 or more, 2.7 or more, 3.0 or more, 3.5 or more, 4.0 or more, 4.5 or more, 4.7 or more, 5.0 or more, 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 by-product to 2-ethylhexyl (2-hydroxyethyl) terephthalate in the composition may be 1:5 to 8. When the weight ratio of the by-product to 2-ethylhexyl (2-hydroxyethyl) terephthalate in the plasticizer composition satisfies the above-mentioned range, the plasticizer composition can have an excellent effect of improving migration resistance, excellent heat loss and absorption speed, and can smoothly blend with the resin and smoothly perform the rolling process after the blending, thereby increasing process stability.

[0074] In addition, the weight ratio of the by-product to the total content of di(n-butyl) terephthalate, (n-butyl)(2-ethylhexyl) terephthalate, and di(2-ethylhexyl) terephthalate in the composition may be 1:20 to 150, and may be, for example, 1:20 or more, 25 or more, 30 or more, 35 or more, 40 or more, 45 or more, 50 or more, 55 or more, 60 or more, 65 or more, 70 or more, 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 by-product to the total content of di(n-butyl) terephthalate, (n-butyl)(2-ethylhexyl) terephthalate, and di(2-ethylhexyl) terephthalate in the composition may be 1:20 to 80. When the ratio of the by-product to the total content of di(n-butyl) terephthalate, (n-butyl)(2-ethylhexyl) terephthalate, and di(2-ethylhexyl) terephthalate is within the above-mentioned range, the effect of improving migration resistance achieved by including a by-product containing a dimer compound in the plasticizer composition is maximized.

[0075] A hydrogenation method can be applied to the plasticizer composition of the present invention. The present invention can provide a plasticizer composition comprising 2-ethylhexyl(2-hydroxyethyl)cyclohexane-1,4-dicarboxylate and di(2-ethylhexyl)cyclohexane-1,4-dicarboxylate, and the content of the 2-ethylhexyl(2-hydroxyethyl)cyclohexane-1,4-dicarboxylate is 20% by weight or less based on the total weight of the plasticizer composition. The plasticizer composition may further comprise a hydrogenation product of the dimer compound represented by the chemical formulas 1 to 5.

[0076] The plasticizer composition containing 2-ethylhexyl(2-hydroxyethyl)cyclohexane-1,4-dicarboxylate and di(2-ethylhexyl)cyclohexane-1,4-dicarboxylate is obtained by hydrogenating a product produced by transesterification of polyethylene terephthalate (hereinafter, PET) with 2-ethylhexanol, and the order of the transesterification and hydrogenation reactions may be changed. The product contains the above-mentioned 2-ethylhexyl(2-hydroxyethyl)terephthalate, di(n-butyl)terephthalate, (n-butyl)(2-ethylhexyl)terephthalate, and di(2-ethylhexyl)terephthalate, and may further contain the dimer compounds of the above-mentioned chemical formulas 1 to 5.

[0077] The plasticizer composition can eliminate environmental problems and significantly improve migration and weight loss properties, and can realize products with significantly improved light resistance and heat resistance compared to conventional commercial products.

[0078] Method for producing plasticizer composition The present invention provides a method for producing the aforementioned plasticizer composition. Specifically, the present invention includes a method for producing the plasticizer composition, 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. The product produced by the transesterification reaction of mixing polyethylene terephthalate and 2-ethylhexanol includes 2-ethylhexyl(2-hydroxyethyl)terephthalate and di(2-ethylhexyl)terephthalate, and may further include by-products including any one or more of the dimer compounds represented by the above-mentioned chemical formulas 1 to 5.

[0079] The PET and 2-ethylhexanol are converted into a composition containing the two components through a transesterification reaction. Specifically, the PET is represented by the following chemical formula a:

[0080] [ka]

[0081] In the transesterification reaction of PET and 2-ethylhexanol, 2-ethylhexanol reacts with an ester group present in PET to unchain the polymer chain of PET. Depending on how the reaction is controlled, the ratio of the two components, 2-ethylhexyl(2-hydroxyethyl)terephthalate and di(2-ethylhexyl)terephthalate, can be adjusted. It is important to adjust not only the ratio of the two components but also the ratio of the by-product including the dimer compound within the above-mentioned range.

[0082] The PET may be contained in an amount of 80% by weight or less, preferably 60% by weight or less, more preferably 50% by weight, 40% by weight, or 35% by weight or less, based on the total content of the PET and 2-ethylhexanol. When the PET content is within the above range, the amount of 2-ethylhexanol added is sufficient, which can minimize side reactions and maximize the desired transesterification reaction between PET and 2-ethylhexanol. In particular, when the PET content is within the above range, the composition obtained through the manufacturing process satisfies the above-mentioned preferred content conditions, which is advantageous in that post-treatment after the manufacturing process can be minimized and a plasticizer composition with excellent physical properties can be readily manufactured.

[0083] On the other hand, the PET may contain 50% by weight or more of waste PET, preferably 60% by weight or more, and more preferably 70% by weight or more. Even if waste PET is used, the ratio of components in the final product does not change, so if the color of the plasticizer and the impurity content can be controlled, it is possible to use all of the waste PET. Since waste PET is utilized in this way, it is very cost-competitive compared to di(2-ethylhexyl) terephthalate produced from terephthalic acid or dimethyl terephthalate, and it is possible to prevent the energy consumption and environmental pollution used in producing terephthalic acid or dimethyl terephthalate, which can greatly contribute to improving the environment.

[0084] In the manufacturing method according to one embodiment of the present invention, by-products generated during the reaction, such as ethylene glycol, are recovered outside the system, but a part of the by-products may remain in the reaction system. If a part of the ethylene glycol is maintained in the reaction system so as to participate in the reaction, an appropriate level of 2-ethylhexyl (2-hydroxyethyl) terephthalate and the dimer compounds of the chemical formulas 1 to 5 are formed from the ethylene glycol remaining in the reaction system, and the 2-ethylhexyl (2-hydroxyethyl) terephthalate and the dimer compounds of the chemical formulas 1 to 5 contribute to improving the performance of the plasticizer composition, so that there is no need to consume additional energy to remove the formed 2-ethylhexyl (2-hydroxyethyl) terephthalate and the dimer compounds of the chemical formulas 1 to 5, and the manufacturing process can be operated economically. In particular, since ethylene glycol is used as a reactant for forming the 2-ethylhexyl (2-hydroxyethyl) terephthalate and the dimer compounds of the chemical formulas 1 to 5, the content of ethylene glycol in the final composition is naturally very low, and the separation process can be simplified.

[0085] The catalyst may be one or more selected from the following: acid catalysts such as sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, paratoluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, and alkylsulfuric acid; metal salts such as aluminum lactate, lithium fluoride, potassium chloride, cesium chloride, calcium chloride, iron chloride, and aluminum phosphate; metal oxides such as heteropolyacids; natural / synthetic zeolites; cation and anion exchange resins; catalysts containing choline compounds such as choline chloride, choline hydroxide, choline bicarbonate, choline hydrogen tartrate, choline dihydrogen citrate, and choline sulfate; organic metals such as alkyl titanates such as tetra alkyl titanate or their polymers; and organic metals containing zirconium or tin. Preferably, tetra alkyl titanate may be used as the catalyst.

[0086] The amount of catalyst used may vary depending on the type. For example, in the case of a homogeneous catalyst, the amount may be within the range of 0.01 to 5 wt%, 0.01 to 3 wt%, 1 to 5 wt%, or 2 to 4 wt%, relative to 100 wt% of the total amount of reactants. In the case of a heterogeneous catalyst, the amount may be within the range of 5 to 200 wt%, 5 to 100 wt%, 20 to 200 wt%, or 20 to 150 wt% of the total amount of reactants.

[0087] 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, preferably 135°C to 230°C, more preferably 141°C to 220°C for 10 minutes to 12 hours, preferably 30 minutes to 10 hours, more preferably 1 to 8 hours. Within the above-mentioned temperature and time ranges, the component ratio of the final plasticizer composition can be efficiently controlled. In this case, the reaction time can be calculated from the time when the reaction temperature is reached after the temperature of the reactants is increased.

[0088] In addition, the method may further include a step of removing unreacted 2-ethylhexanol and reaction by-products such as ethylene glycol after the transesterification reaction is completed. Ethylene glycol has high solubility in water, so it can be removed through a neutralization and water washing process after the reaction is completed, and the remaining 2-ethylhexanol can be removed by extractive distillation after neutralization and water washing. Through the above steps, a plasticizer composition having the desired components and composition ratio can be produced.

[0089] After the above-mentioned transesterification reaction between PET and 2-ethylhexanol is completed, a transesterification reaction between the reaction product and n-butanol can be continued. The reaction conditions in this step, including the catalyst, reaction temperature, and time, can be the same as those in the above-mentioned steps. In this step, the amount of n-butanol added can be 5 to 40 wt %, preferably 10 to 30 wt %, based on the weight of di(2-ethylhexyl) terephthalate produced in the previous step. When the amount of n-butanol added is appropriately adjusted within the above-mentioned range, each component in the final plasticizer composition is contained in an appropriate content, and the overall physical property balance can be well maintained.

[0090] According to another embodiment of the present invention, there is provided a resin composition comprising the plasticizer composition described above and a resin. The resin may be any resin well known in the art, such as, but not limited to, a mixture of one or more selected from the group consisting of straight vinyl chloride polymer, paste vinyl chloride polymer, ethylene-vinyl acetate copolymer, ethylene polymer, propylene polymer, polyketone, polystyrene, polyurethane, polylactic acid, natural rubber, synthetic rubber, and thermoplastic elastomer.

[0091] The plasticizer composition may be included 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 the resin.

[0092] Generally, the resins in which the plasticizer composition is used can be manufactured into resin products by melt processing or plastisol processing, and melt-processed resins and plastisol-processed resins may be produced differently depending on the polymerization method.

[0093] For example, when vinyl chloride polymer is used in melt processing, it is produced by suspension polymerization or the like, and solid resin particles with a large average particle size are used, and such vinyl chloride polymer is called straight vinyl chloride polymer, and when it is used in plastisol processing, it is produced by emulsion polymerization or the like, and a resin in a sol state is used as fine resin particles, and such vinyl chloride polymer is called paste vinyl chloride resin.

[0094] In this case, in the case of the straight vinyl chloride polymer, the plasticizer is preferably contained in a range of 5 to 80 parts by weight per 100 parts by weight of the polymer, and in the case of a paste vinyl chloride polymer, the plasticizer is preferably contained in a range of 40 to 120 parts by weight per 100 parts by weight of the polymer.

[0095] The resin composition may further contain a filler, the amount of which may be 0 to 300 parts by weight, preferably 50 to 200 parts by weight, and more preferably 100 to 200 parts by weight, based on 100 parts by weight of the resin.

[0096] The filler may be any filler known in the art, and is not particularly limited.For example, it may be a mixture of one or more selected from silica, magnesium carbonate, calcium carbonate, hard carbon, talc, magnesium hydroxide, titanium dioxide, magnesium oxide, calcium hydroxide, aluminum hydroxide, aluminum silicate, magnesium silicate, and barium sulfate.

[0097] Furthermore, the resin composition may further contain other additives such as a stabilizer, if necessary. The amount of each of the other additives such as a stabilizer may be, for example, 0 to 20 parts by weight, preferably 1 to 15 parts by weight, based on 100 parts by weight of the resin.

[0098] The stabilizer may be, for example, a calcium-zinc (Ca-Zn) stabilizer such as a calcium-zinc complex stearate or a barium-zinc (Ba-Zn) stabilizer, but is not limited thereto.

[0099] The resin composition may be applied to both melt processing and plastisol processing as described above. For example, the melt processing may be a calendar process, an extrusion process, or an injection process, and the plastisol processing may be a coating process.

[0100] Working Example The present invention will be described in detail below with reference to examples. However, the examples of the present invention may be modified in various different forms, and the scope of the present invention should not be construed as being limited to the examples described below. The examples of the present invention are provided to more completely explain the present invention to those having ordinary skill in the art.

[0101] Example 1 1.5g of catalyst TnBT, 500g of waste polyethylene terephthalate, and 1220g of 2-ethylhexanol were added to a reactor equipped with an agitator, condenser, and decanter, and then trans-esterification reaction was carried out for 3 to 8 hours at a reaction temperature of 150 to 230°C under a nitrogen atmosphere. After the reaction was completed, the unreacted 2-ethylhexanol was removed by reducing the pressure. Through the above process, a composition containing 0.2% by weight and 97.5% by weight of 2-hydroxyethyl (2-ethylhexyl) terephthalate and di(2-ethylhexyl) terephthalate (DEHTP), respectively, was obtained. The remaining components in the composition, excluding the above two components, include by-products and intermediates generated during the reaction process.

[0102] Then, 1000g of the reactant obtained above and 190g of n-butanol (19 parts by weight based on 100 parts by weight of the reactant) were added, and a trans-esterification reaction was carried out for 2 hours at a reaction temperature of 160°C under a nitrogen atmosphere, and a purification process was carried out to obtain an ester-based plasticizer composition containing 0.9% by weight of 2-ethylhexyl (2-hydroxyethyl) terephthalate, 5.3% by weight of di(n-butyl) terephthalate (DBTP), 38.2% by weight of (n-butyl) (2-ethylhexyl) terephthalate, and 53.9% by weight of di(2-ethylhexyl) terephthalate. The remaining components in the composition, such as dimer compounds, except for the four components, include by-products generated during the reaction process, and the contents of the by-products are shown in Table 1 below.

[0103] Example 2 By adjusting the amount of 2-ethylhexanol added and the reaction time in the same manner as in Example 1, an ester-based plasticizer composition containing 8.6 wt% 2-hydroxyethyl(2-ethylhexyl)terephthalate, 3.8 wt% di(n-butyl)terephthalate, 34.1 wt% (n-butyl)(2-ethylhexyl)terephthalate, and 50.2 wt% di(2-ethylhexyl)terephthalate was obtained. The remaining components in the composition, such as dimer compounds, excluding the above four components, include by-products generated during the reaction process, and the contents of the by-products are shown in Table 1 below.

[0104] Example 3 By adjusting the amount of 2-ethylhexanol added and the reaction time in the same manner as in Example 1, an ester-based plasticizer composition containing 19.4 wt% 2-hydroxyethyl(2-ethylhexyl)terephthalate, 1.9 wt% di(n-butyl)terephthalate, 28.7 wt% (n-butyl)(2-ethylhexyl)terephthalate, and 45.3 wt% di(2-ethylhexyl)terephthalate was obtained. The remaining components in the composition, such as dimer compounds, excluding the above four components, include by-products generated during the reaction process, and the contents of the by-products are shown in Table 1 below.

[0105] Reference example 1.5g of catalyst TnBT, 500g of discarded polyethylene terephthalate, and 1220g of 2-ethylhexanol were added to a reactor equipped with an agitator, a condenser, and a decanter, and then trans-esterification reaction was carried out for 8 hours at a reaction temperature of 150-230°C under a nitrogen atmosphere. After the reaction was completed, the unreacted 2-ethylhexanol was removed by reducing the pressure. Then, 100g of a 3 wt% aqueous sodium hydroxide solution was added to neutralize the catalyst, and a small amount of unreacted 2-ethylhexanol was removed by distillation. Through the above process, all of the 2-hydroxyethyl (2-ethylhexyl) terephthalate in the composition was removed, and a composition containing 99.9 wt% di(2-ethylhexyl) terephthalate (DEHTP) was obtained.

[0106] Comparative Example 1 The same procedure as in Example 1 was repeated, but by adjusting the amount of 2-ethylhexanol added and the reaction time, all of the 2-hydroxyethyl(2-ethylhexyl)terephthalate in the composition was removed, and an ester-based plasticizer composition containing 5.9% by weight of di(n-butyl)terephthalate, 39.2% by weight of (n-butyl)(2-ethylhexyl)terephthalate, and 54.9% by weight of di(2-ethylhexyl)terephthalate was obtained.

[0107] Comparative Example 2 By adjusting the amount of 2-ethylhexanol added and the reaction time in the same manner as in Example 1, an ester-based plasticizer composition containing 22.5 wt% 2-hydroxyethyl(2-ethylhexyl)terephthalate, 1.7 wt% di(n-butyl)terephthalate, 26.7 wt% (n-butyl)(2-ethylhexyl)terephthalate, and 41.2 wt% di(2-ethylhexyl)terephthalate was obtained. The remaining components in the composition, such as dimer compounds, excluding the above four components, include by-products generated during the reaction process, and the contents of the by-products are shown in Table 1 below.

[0108] [Table 1]

[0109] Experimental example 1: Evaluation of seat performance Using the plasticizers of the Examples and Comparative Examples, test pieces were prepared according to the following recipe and preparation conditions in accordance with ASTM D638.

[0110] (1) Formulation: 100 parts by weight of straight vinyl chloride polymer (LS100), 50 parts by weight of plasticizer, and 3 parts by weight of stabilizer (BZ-153T). (2) Blending: Mix at 98°C and 700 rpm (3) Preparation of test pieces: 1T~3T sheets were prepared by working in a roll mill at 160°C for 4 minutes, and in a press at 180°C for 2.5 minutes (low pressure) and 2 minutes (high pressure).

[0111] (4) Evaluation items 1)Hardness : Shore hardness (Shore "A" and "D") at 25°C was measured for 10 seconds on a 3T test piece in accordance with ASTM D2240. The smaller the value, the better the plasticization efficiency.

[0112] 2) Tensile strength According to ASTM D638, a tester UTM (manufacturer: Instron, model name: 4466) was used to measure the point at which a 1T specimen broke after pulling at a cross head speed of 200 mm / min. The tensile strength was calculated as follows: Tensile strength (kgf / cm 2 ) = Load value (kgf) / thickness (cm) x width (cm)

[0113] 3) Measurement of elongation rate: According to the ASTM D638 method, the UTM was used to pull the 1T test piece at a cross head speed of 200 mm / min, and the point at which the 1T test piece broke was measured, and the elongation was calculated as follows: The elongation rate (%) was calculated as follows: length after elongation / initial length×100.

[0114] 4) Measurement of tensile and elongation retentionTensile and elongation retention was measured by heating the test piece at 100°C for 168 hours and then measuring the tensile strength and elongation remaining in the test piece. The measurement method was the same as that for measuring tensile strength and elongation.

[0115] 5) Measurement of migration loss Measured according to KSM-3156. Specifically, a test piece with a thickness of 1 mm was obtained, and absorbent paper capable of absorbing organic matter that migrates and flows onto the surface was attached to both sides of the test piece, and then a plate capable of covering the entire test piece was attached on top of the absorbent paper, and the test piece was subjected to a pressure of 1 kgf / cm 2 A load of 10 ... Migration loss (%) = {(initial weight of test piece at room temperature - weight of test piece after leaving in oven) / initial weight of test piece at room temperature} x 100

[0116] 6) Measurement of volatile loss The test piece prepared above was worked at 80°C for 72 hours, and then the weight of the test piece was measured. Heat loss (wt %)=initial test piece weight−(test piece weight after 72 hours at 80° C.) / initial test piece weight×100.

[0117] 7) Stress test (stress resistance) : A 2mm thick test piece was left in a bent state at 23℃ for 168 hours, and the degree of migration (exudation) was observed on the 1st, 3rd, and 7th days, and the results were expressed as a numerical value. The closer the numerical value is to 0, the better the stress resistance.

[0118] 8) Measurement of absorption rate The processability was evaluated by measuring the time it took for the resin and plasticizer to be mixed together using a planetary mixer (Brabender, P600) at 73°C and 60 rpm and for the torque of the mixer to stabilize.

[0119] (5) Evaluation results The evaluation results for the above-mentioned items are shown in Tables 2 and 3 below.

[0120] [Table 2]

[0121] [Table 3]

[0122] Referring to Tables 2 and 3, in the case of Examples 1 to 3, compared with the Reference Example, which is a di(2-ethylhexyl) terephthalate-based plasticizer composition that is a ready-to-use product, waste PET is used as a raw material, which is environmentally friendly and reduces manufacturing costs, and even though it contains by-products, it shows excellent results in terms of mechanical properties, migration loss, absorption rate, and stress resistance. That is, the plasticizer composition of the present invention shows improvements in stress resistance, migration loss, absorption rate, and mechanical properties without a decrease in conventional physical properties by applying both 2-ethylhexyl(2-hydroxyethyl) terephthalate and by-products containing any one or more of Chemical Formulas 1 to 5. In general, in the case of a composition in which two components are mixed, the effect of the mixed composition appears in the direction in which the effects of each component are diluted by each other, but in the present invention, unlike this, the conventional level of physical properties is maintained and improvements in stress resistance and mechanical properties are achieved, and it can be confirmed that the present invention achieves effects that cannot be predicted from conventional techniques.

[0123] On the other hand, in Comparative Example 1, the amount of 2-ethylhexanol added and the reaction time were adjusted to completely remove 2-ethylhexyl (2-hydroxyethyl) terephthalate from the final composition, and although the manufacturing process cost was higher than that of Examples 1 to 3, the properties of the plasticizer composition finally obtained were at the same level as those of the plasticizer compositions of Examples 1 to 3, and in particular, the heat loss, migration resistance, stress resistance, and mechanical properties were inferior to those of the Examples. From this, it can be confirmed that the plasticizer composition of the present invention has a lower manufacturing cost and is superior in function of the plasticizer itself compared to the conventional plasticizer compositions containing di(n-butyl) terephthalate, (n-butyl)(2-ethylhexyl) terephthalate, and di(2-ethylhexyl) terephthalate recovered from polyethylene terephthalate.

[0124] Meanwhile, Comparative Example 2 is a plasticizer composition prepared from polyethylene terephthalate in the same manner as in the Examples of the present invention, but the amount of 2-ethylhexanol added and the reaction time were adjusted, and the content of by-products including 2-ethylhexyl (2-hydroxyethyl) terephthalate and / or dimer compounds according to the present invention was different. Although the plasticization efficiency was at the same level as in Examples 1 to 3, the mechanical properties and stress resistance were inferior to those of the Examples. In particular, the elongation retention rate among the mechanical properties was significantly inferior to those of Examples 1 to 3. From this, it can be confirmed that the plasticizer composition of the present invention limits the content of each compound to maximize the improvement of various properties such as mechanical properties, stress resistance, heat resistance, and migration resistance, and has superior functionality as a plasticizer compared to the plasticizer of Comparative Example 2, which does not contain the content of by-products including 2-ethylhexyl (2-hydroxyethyl) terephthalate and / or dimer compounds according to the present invention.

Claims

1. 2-ethylhexyl(2-hydroxyethyl)terephthalate, di(n-butyl)terephthalate, (n-butyl)(2-ethylhexyl)terephthalate, and di(2-ethylhexyl)terephthalate, The plasticizer composition has a content of 2-ethylhexyl (2-hydroxyethyl) terephthalate of 20% by weight or less based on the total weight of the plasticizer composition.

2. 2. The plasticizer composition of claim 1, wherein the content of 2-ethylhexyl (2-hydroxyethyl) terephthalate is 0.01 to 15% by weight.

3. 10. The plasticizer composition of claim 1 further comprising n-butyl (2-hydroxyethyl) terephthalate.

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

5. The plasticizer composition of claim 1, further comprising a by-product comprising any one or more of the dimer compounds represented by the following formulas 1 to 5: 【Chemistry 1】

6. The plasticizer composition of claim 5, wherein the total content of said by-products in the composition is 0.1-5.0 wt.%.

7. The plasticizer composition of claim 5, wherein the weight ratio of said by-product to 2-ethylhexyl (2-hydroxyethyl) terephthalate in the composition is 1:1-10.

8. The plasticizer composition of claim 5, wherein the weight ratio of the by-products to the total content of di(n-butyl) terephthalate, (n-butyl)(2-ethylhexyl) terephthalate, and di(2-ethylhexyl) terephthalate in the composition is 1:20.0-150.

0.

9. mixing polyethylene terephthalate and 2-ethylhexanol in the presence of a catalyst to cause a transesterification reaction; and adding n-butanol to the reactants to effect a transesterification reaction.

10. The method according to claim 9, wherein the polyethylene terephthalate is mixed in an amount of 80% by weight or less based on the total content of the polyethylene terephthalate and 2-ethylhexanol.

11. The method according to claim 9, wherein the polyethylene terephthalate is mixed in an amount of 60% by weight or less based on the total content of the polyethylene terephthalate and 2-ethylhexanol.

12. 10. The method of claim 9, wherein the polyethylene terephthalate comprises discarded recycled polyethylene terephthalate.

13. A resin composition comprising 100 parts by weight of a resin and 5 to 150 parts by weight of the plasticizer composition of claim 1.

14. The resin composition according to claim 13, wherein the resin is at least one selected from the group consisting of 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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