Plasticizer composition and resin composition containing the same

Abstract

The present invention is characterized in that it comprises a terephthalate composition and a citrate composition, wherein the terephthalate composition comprises dihexyl terephthalate, hexyl (2-ethylhexyl) terephthalate and di(2-ethylhexyl) terephthalate, and the citrate composition comprises trihexyl citrate, and the hexyl of the terephthalate and the hexyl of the citrate are derived from an isomer mixture of hexanol. If the composition is applied to a resin, migration resistance and stress resistance can be improved, and on the other hand, mechanical properties can be improved.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority based on Korean Patent Application No. 10-2021-0013021 filed on January 29, 2021, which is hereby incorporated by reference in its entirety. Technical Field

[0004] The present invention relates to a plasticizer composition comprising a terephthalate ester composition and a citrate ester composition, and a resin composition comprising the same. Background Art

[0005] Generally, plasticizers are obtained by reacting alcohols with polycarboxylic acids such as phthalic acid and adipic acid to form corresponding esters. In addition, considering the domestic and international regulations on phthalate plasticizers that are harmful to the human body, research is continuing on plasticizer compositions such as terephthalate esters, adipic acid esters and other polymer plasticizers that can replace phthalate plasticizers.

[0006] At the same time, the demand for environmentally friendly products is increasing regardless of the industry type, including plastisol industry type, calendaring industry type, extrusion / injection composite industry type, etc., including floor materials, wallpapers, soft boards and hard boards. In order to enhance the quality characteristics, processability and productivity of the finished product, suitable plasticizers are required in consideration of discoloration, migration, mechanical properties, etc.

[0007] Supplementary materials such as plasticizers, fillers, stabilizers, viscosity reducers, dispersants, defoamers and foaming agents are mixed with PVC resin according to the properties required by the industry types in various application fields, such as tensile strength, elongation, light resistance, migration, gelling and absorption rate.

[0008] For example, in the case of di(2-ethylhexyl) terephthalate (DEHTP), which is relatively cheap and widely used in a plasticizer composition applicable to PCV, the hardness or sol viscosity is high, the absorption rate of the plasticizer is relatively slow, and the mobility and stress migration properties are poor.

[0009] As an improvement to the above limitations, it is possible to consider using a transesterification product with butanol as a plasticizer in a composition containing DEHTP. In this case, the plasticizing efficiency is improved, but the volatility loss or thermal stability is poor, the mechanical properties are slightly reduced, and the physical properties need to be improved. Therefore, there is generally no solution, but currently a method of compensating for the defects by mixing with a second plasticizer is adopted.

[0010] However, in the case of applying the second plasticizer, there are disadvantages that the following unexpected defects occur: changes in physical properties are difficult to predict; application may become a factor in increasing the unit cost of the product; improvement in physical properties is not clearly shown except in specific cases; and problems related to resin compatibility may occur.

[0011] In addition, if materials such as tri(2-ethylhexyl) trimellitate or triisononyl trimellitate are used as trimellitate products to improve the poor mobility and loss properties and light resistance of DEHTP products, the mobility or loss properties may be improved, but the plasticizing efficiency may be reduced, and a large amount of material needs to be injected to provide a suitable plasticizing effect for the resin, and considering the relatively high unit price of the product, its commercialization is impossible.

[0012] Likewise, if materials are mixed, not all excellent physical properties may be achieved, but there may be situations where only inferior physical properties are achieved, and there are tasks to be solved in the art, including the disadvantage that the advantages of the diluted mixed components occur very frequently and cannot be used as an improved product.

[0013] Products for solving the environmental problems of commonly used phthalate products or environmentally friendly plasticizers for improving the environmental problems of phthalate products have very excellent specific physical properties, but other specific properties are poor and cannot be used in large quantities. Therefore, it is necessary to develop a blended plasticizer product that has an excellent balance between physical properties without showing any poor properties and can achieve the advantages of only two components when blended. Summary of the invention

[0014] Technical issues

[0015] The present invention provides a plasticizer composition which can improve mechanical properties and plasticizing efficiency to a level comparable to or better than that of conventional plasticizers and at the same time significantly improve migration resistance and stress resistance.

[0016] Technical Solution

[0017] In order to solve the above-mentioned problems, the present invention provides a plasticizer composition and a resin composition.

[0018] (1) The present invention provides a plasticizer composition, which comprises a terephthalate ester composition and a citrate ester composition, wherein the terephthalate ester composition comprises dihexyl terephthalate, hexyl (2-ethylhexyl) terephthalate and di(2-ethylhexyl) terephthalate, and the citrate ester composition comprises trihexyl citrate, the hexyl group of the terephthalate ester and the hexyl group of the citrate ester are derived from an isomer mixture of hexanols, and the isomer mixture of hexanols comprises two or more selected from the group consisting of 1-hexanol, 1-methylpentanol, 2-methylpentanol, 3-methylpentanol, 4-methylpentanol, 1,1-dimethylbutanol, 1,2-dimethylbutanol, 1,3-dimethylbutanol, 2,2-dimethylbutanol, 2,3-dimethylbutanol, 3,3-dimethylbutanol, 1-ethylbutanol, 2-ethylbutanol, 3-ethylbutanol and cyclopentylmethanol.

[0019] (2) The present invention provides a plasticizer composition as described in (1) above, wherein the terephthalate composition comprises: 0.5 wt % to 50.0 wt % of dihexyl terephthalate; 3.0 wt % to 70.0 wt % of hexyl (2-ethylhexyl) terephthalate; and 0.5 wt % to 95.0 wt % of di(2-ethylhexyl) terephthalate.

[0020] (3) The present invention provides the plasticizer composition described in (1) or (2) above, wherein the citrate ester composition comprises one or more citrate esters of the following formula 1.

[0021] [Formula 1]

[0022]

[0023] In Formula 1, R1 to R3 are each independently a n-hexyl group, a branched hexyl group or a cyclopentylmethyl group, and R4 is hydrogen.

[0024] (4) The present invention provides the plasticizer composition according to any one of (1) to (3) above, wherein the weight ratio of the terephthalate ester composition to the citrate ester composition is 95:5 to 5:95.

[0025] (5) The present invention provides the plasticizer composition described in any one of (1) to (4) above, wherein the weight ratio of the terephthalate ester composition to the citrate ester composition is 95:5 to 50:50.

[0026] (6) The present invention provides the plasticizer composition according to any one of (1) to (5) above, wherein the isomer mixture of hexanol contains 2-methylpentanol and 3-methylpentanol.

[0027] (7) The present invention provides the plasticizer composition according to any one of (1) to (6) above, wherein the isomer mixture contains 40 parts by weight or more of a branched alcohol based on 100 parts by weight of the isomer mixture of hexanol.

[0028] (8) The present invention provides the plasticizer composition described in any one of (1) to (7) above, wherein the isomer mixture contains 50 to 95 parts by weight of a branched alcohol based on 100 parts by weight of the isomer mixture of hexanol.

[0029] (9) The present invention provides the plasticizer composition according to any one of (1) to (8) above, wherein the isomer mixture of hexanol further contains 1-hexanol.

[0030] (10) The present invention provides the plasticizer composition according to any one of (1) to (9) above, wherein the isomer mixture contains 40 parts by weight or less of 1-hexanol based on 100 parts by weight of the isomer mixture of hexanol.

[0031] (11) The present invention provides the plasticizer composition according to any one of (1) to (10) above, wherein the isomer mixture of hexanol further contains 4-methylpentanol.

[0032] (12) The present invention provides the plasticizer composition according to any one of (1) to (11) above, wherein the isomer mixture of hexanol further contains cyclopentylmethanol.

[0033] (13) The present invention provides the plasticizer composition described in any one of (1) to (12) above, wherein the isomer mixture contains 20 parts by weight or less of cyclopentylmethanol based on 100 parts by weight of the isomer mixture of hexanol.

[0034] (14) 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 described in any one of (1) to (13) above.

[0035] (15) The present invention provides a resin composition as described in (14) above, wherein the resin is one or more selected from the group consisting of linear vinyl chloride polymers, paste vinyl chloride polymers, ethylene-vinyl acetate copolymers, ethylene polymers, propylene polymers, polyketones, polystyrene, polyurethanes, polylactic acid, natural rubber and synthetic rubber.

[0036] Beneficial Effects

[0037] When used in a resin composition, the plasticizer composition according to an embodiment of the present invention can improve mechanical properties and plasticization efficiency to a level comparable to or better than that of conventional plasticizers, and at the same time significantly improve migration resistance and stress resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a graph showing the evaluation results of the carbonization properties of the plasticizer compositions of Examples 1 to 5 of the present invention and the plasticizer compositions of Comparative Examples 1 to 6. DETAILED DESCRIPTION

[0039] It should be understood that the terms or words used in the present disclosure and claims should not be interpreted as having the meanings defined in general or dictionaries, but should be interpreted as being consistent with the technical scope of the present invention based on the concept that the inventor can appropriately define the terms in order to explain the present invention in its best way.

[0040] Definition of terms

[0041] The term "composition" as used in this disclosure includes mixtures comprising materials of the corresponding composition, as well as reaction products and decomposition products formed from the materials of the corresponding composition.

[0042] The "linear vinyl chloride polymer" used in the present disclosure may be a vinyl chloride polymer obtained by suspension polymerization, bulk polymerization, etc. The polymer has porous particles having a large number of pores with a size of tens to hundreds of micrometers, no agglomeration and excellent fluidity.

[0043] The "paste vinyl chloride polymer" used in the present disclosure may be a vinyl chloride polymer obtained by microsuspension polymerization, microseed polymerization, emulsion polymerization, etc. The polymer has fine and dense non-porous particles with a size of tens to thousands of nanometers, cohesiveness and poor fluidity.

[0044] With regard to the terms "comprising" and "having" and their derivatives in the present invention, whether or not these terms are specifically disclosed, they are not intended to exclude the presence of optional additional ingredients, steps or processes. In order to avoid any uncertainty, all compositions defined by the use of the term "comprising" may include optional additional additives, adjuvants or compounds, including polymers or any other materials, unless otherwise described to the contrary. In contrast, the term "consisting essentially of" excludes from the scope of the optional continuous description those that are not necessary for operation and does not include optional other ingredients, steps or processes. The term "consisting of" does not include optional ingredients, steps or methods that are not specifically described or illustrated.

[0045] Measurement method

[0046] In the present disclosure, the content analysis of the ingredients in the composition is carried out by gas chromatography measurement using a gas chromatography equipment of Agilent Co. (product name: Agilent 7890GC, column: HP-5, carrier gas: helium (flow rate 2.4 ml / min), detector: FID, injection volume: 1 μl, starting value: 70°C / 4.2 min, final value: 280°C / 7.8 min, program rate: 15°C / min).

[0047] In the present disclosure, "hardness" means Shore hardness (Shore "A" and / or Shore "D") at 25°C and is measured under the condition of 3T 10s using ASTMD 2240. Hardness can be an index for evaluating plasticization efficiency, and the lower the value, the better the plasticization efficiency.

[0048] In the present disclosure, "tensile strength" is obtained by stretching a sample at a crosshead speed of 200 mm / min (1 T) using a UTM testing device (manufacturer: Instron, model: 4466) according to the ASTM D638 method, measuring the point where the sample is cut, and calculating according to the following Mathematical Formula 1:

[0049] [Mathematical formula 1]

[0050] Tensile strength (kgf / cm 2 ) = load value (kgf) / thickness (cm) × width (cm)

[0051] In the present disclosure, "elongation" is calculated according to the ASTM D638 method by stretching a sample at a crosshead speed of 200 mm / min (1 T) using UTM, measuring the point at which the sample is cut, and according to the following Mathematical Formula 2:

[0052] [Mathematical formula 2]

[0053] Elongation (%) = elongated length / initial length × 100

[0054] In the present disclosure, "migration loss" is obtained according to KSM-3156, wherein a sample having a thickness of 2 mm or more is obtained, glass plates are attached to both sides of the sample, and 1 kgf / cm 2 The sample was placed in a hot air circulation oven (80°C) for 72 hours, then taken out and cooled at room temperature for 4 hours. Then, the glass plates attached to both sides of the sample were removed, the weights of the glass plates and the sample plate before and after being placed in the oven were measured, and the migration loss was calculated according to the following mathematical formula 3.

[0055] [Mathematical formula 3]

[0056] Migration loss (%) = {[(initial sample weight) - (sample weight after standing in the oven] / (initial sample weight)} × 100

[0057] In the present disclosure, "volatilization loss" is obtained by treating a sample at 80°C for 72 hours and then measuring the weight of the sample.

[0058] [Formula 4]

[0059] Volatilization loss (weight %) = {[(initial sample weight) - (sample weight after treatment)] / (initial sample weight)} × 100

[0060] In the case of various measurement conditions, the details of the conditions such as temperature, rotation speed and time may be slightly changed depending on the situation, and if the conditions are different, it is necessary to separately indicate the measurement method and its conditions.

[0061] Hereinafter, the present invention will be described in more detail to help understanding of the present invention.

[0062] According to an embodiment of the present invention, the plasticizer composition is characterized in that it comprises a terephthalate composition and a citrate composition, wherein the terephthalate composition comprises dihexyl terephthalate, hexyl (2-ethylhexyl) terephthalate and di(2-ethylhexyl) terephthalate, the citrate composition comprises trihexyl citrate, the hexyl group of the terephthalate and the hexyl group of the citrate are derived from an isomer mixture of hexanol, and the isomer mixture of hexanol comprises two or more selected from the group consisting of 1-hexanol, 1-methylpentanol, 2-methylpentanol, 3-methylpentanol, 4-methylpentanol, 1,1-dimethylbutanol, 1,2-dimethylbutanol, 1,3-dimethylbutanol, 2,2-dimethylbutanol, 2,3-dimethylbutanol, 3,3-dimethylbutanol, 1-ethylbutanol, 2-ethylbutanol, 3-ethylbutanol and cyclopentylmethanol.

[0063] As a component of the plasticizer composition according to the embodiment of the present invention, a terephthalate ester composition is used, and the terephthalate ester composition includes dihexyl terephthalate, hexyl (2-ethylhexyl) terephthalate, and di (2-ethylhexyl) terephthalate.

[0064] Generally, terephthalate compositions use alcohols with a large carbon number difference, thereby having the advantages of both alcohols with a small carbon number and alcohols with a large carbon number. However, in the present invention, it was confirmed that by combining hexanol and 2-ethylhexanol as two alcohols with a small carbon number difference, a balance between excellent plasticizing efficiency, good mechanical properties, excellent loss resistance and physical properties can be achieved.

[0065] In addition, according to an embodiment of the present invention, in the terephthalate-based composition, by obtaining a hexyl group from hexanol of the isomer mixture, when mixed with a citrate-based composition as another component, a maximized synergistic effect can be obtained.

[0066] The terephthalate composition may include 0.5 wt % to 50.0 wt % of dihexyl terephthalate, 3.0 wt % to 70.0 wt % of hexyl terephthalate (2-ethylhexyl) ester, and 0.5 wt % to 95.0 wt % of di(2-ethylhexyl) terephthalate. Preferably, the terephthalate composition may include 0.5 wt % to 30.0 wt % of dihexyl terephthalate, 10.0 wt % to 60.0 wt % of hexyl terephthalate (2-ethylhexyl) ester, and 35.0 wt % to 90.0 wt % of di(2-ethylhexyl) terephthalate. Using such a composition ratio has the advantage that the reproducibility of the above-mentioned effect is excellent, and the balance between the physical properties is appropriate.

[0067] The plasticizer composition according to the embodiment of the present invention uses a citrate ester composition as another component, and the citrate ester composition contains trihexyl citrate. In this case, the hexyl group is derived from hexanol of the isomer mixture.

[0068] As described above, in the application of the citric acid ester composition, if trihexyl citrate prepared by using an alcohol having 6 carbon atoms is applied, a suitable degree of absorption rate can be ensured, processability can be improved, and tensile strength, elongation and volatilization loss can be greatly improved compared to citric acid esters having less than 6 carbon atoms. Compared to citric acid esters having more than 6 carbon atoms, plasticizing efficiency can be excellent, and migration resistance and stress resistance can be greatly improved.

[0069] Meanwhile, compared with commonly used plasticizers, terephthalate ester compositions tend to exhibit relatively poor migration resistance, stress resistance, and elongation in mechanical properties, as well as excellent volatilization loss, carbonization properties, and residual rate properties. In addition, compared with commonly used plasticizers, citrate ester compositions have poor thermal properties and tensile strength, but have excellent plasticizing efficiency, migration resistance, and stress resistance.

[0070] Generally, if two compositions are mixed, the dilution results of the advantages and disadvantages of the two components are shown, but if the terephthalate ester composition and the citrate ester composition having the characteristics of the present invention are mixed, only the advantages of the two components can be shown. In these two components, the same hexyl group is used, but the hexyl group is used through the hexanol of the isomer mixture, so this synergistic effect can be achieved.

[0071] Without the use of a common hexyl group and without the use of an isomeric mixture of hexanol, such a synergistic effect may not be achieved and the results of a mutual dilution of the advantages and disadvantages of the two components may be shown.

[0072] In order to maximize this synergistic effect, the plasticizer composition of the present invention may include a terephthalate composition and a citrate composition in a weight ratio of 95:5 to 5:95, 95:5 to 10:90, 95:5 to 20:80, 95:5 to 30:70, 95:5 to 50:50, 95:5 to 70:30, 90:10 to 10:90, 90:10 to 30:70, 90:10 to 50:50 or 90:10 to 70:30. In the application of the plasticizer composition of the present invention, considering that the terephthalate composition has better thermal stability than the citrate composition, if it is necessary to work under a high temperature environment, a plasticizer composition with a relatively small amount of the citrate composition and a large amount of the terephthalate composition can be used. In contrast, considering that the citrate-based composition has better elongation and migration resistance than the terephthalate-based composition, a plasticizer composition having a large amount of the citrate-based composition and a small amount of the terephthalate-based composition can be used for products requiring high elongation and high migration resistance.

[0073] The citrate composition according to the embodiment of the present invention may include one or more citrates of the following Formula 1.

[0074] [Formula 1]

[0075]

[0076] In Formula 1, R1 to R3 are each independently a n-hexyl group, a branched hexyl group or a cyclopentylmethyl group, and R4 is hydrogen.

[0077] According to an embodiment of the present invention, the hexyl groups of terephthalate and citrate are derived from an isomeric mixture of hexanol.

[0078] The isomer mixture of hexanol includes two or more selected from the group consisting of 1-hexanol, 1-methylpentanol, 2-methylpentanol, 3-methylpentanol, 4-methylpentanol, 1,1-dimethylbutanol, 1,2-dimethylbutanol, 1,3-dimethylbutanol, 2,2-dimethylbutanol, 2,3-dimethylbutanol, 3,3-dimethylbutanol, 1-ethylbutanol, 2-ethylbutanol, 3-ethylbutanol and cyclopentylmethanol.

[0079] According to the alcohol contained in such hexanol isomers, the hexyl groups of terephthalate and citrate can be determined, and the component ratio in the final composition can be determined according to the component ratio of the reacted alcohol.

[0080] The plasticizer composition of the embodiment of the present invention can include 2-methyl amyl alcohol and 3-methyl amyl alcohol in the isomer mixture of hexanol, and can include 1-hexanol, 2-methyl amyl alcohol and 3-methyl amyl alcohol, 2-methyl amyl alcohol, 3-methyl amyl alcohol and 4-methyl amyl alcohol, or 1-hexanol, 2-methyl amyl alcohol, 3-methyl amyl alcohol and 4-methyl amyl alcohol in some cases.If 2-methyl amyl alcohol and 3-methyl amyl alcohol are included together, the balance between the physical properties can be maintained, and excellent effects can be obtained in terms of volatility loss.

[0081] Based on 100 weight parts of isomer mixture, the content of the branched hexanol comprising one or more of 2-methyl amyl alcohol, 3-methyl amyl alcohol and 4-methyl amyl alcohol can be more than 40 weight parts, more than 50 weight parts, more than 60 weight parts, preferably more than 65 weight parts, more than 70 weight parts. As a maximum amount, all can be branched type, or can include less than 99 weight parts, less than 98 weight parts, preferably less than 95 weight parts or less than 90 weight parts. If the branched hexanol is included within the scope, the improvement of mechanical properties can be expected.

[0082] In addition, the content of the linear alcohol 1-hexanol can be 50 parts by weight or less, 40 parts by weight or less, preferably 30 parts by weight or less, based on 100 parts by weight of the isomer mixture. 1-Hexanol may not be present in the composition, but may be included in an amount of at least 2 parts by weight, in which case the advantages of maintaining a balance between physical properties and improving mechanical properties can be achieved. It is theoretically known that linear alcohols show excellent effects, but in the present invention, results different from such theoretical results are obtained. It has been confirmed that if an isomer mixture containing branched alcohols is used, the balance between physical properties is even more excellent.

[0083] The plasticizer composition of the embodiment of the present invention may further include cyclopentylmethanol in the isomer mixture of hexanol. Preferably, by further including cyclopentylmethanol, the balance between physical properties can be maintained, and even the volatility loss can be further improved.

[0084] In this case, cyclopentylmethanol may be 20 parts by weight or less, preferably 15 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the isomer mixture, or may not exist, and in order to obtain the effect thereby, the minimum amount may be 2 parts by weight.

[0085] In particular, depending on the characteristics including the degree of ratio of the branched alkyl group in the total alkyl groups present in the final composition and the degree of ratio of the specific branched alkyl group present in the branched alkyl groups, the balance of the physical properties of plasticizing efficiency and migration / loss properties can be adjusted, and the mechanical properties such as tensile strength and elongation and stress resistance can be maintained at the same or better levels.

[0086] Thereby, environmental problems of conventional phthalate-based products can be eliminated, and products having further improved loss properties can be obtained, and products having a significantly improved balance between physical properties compared with conventional products can be obtained.

[0087] According to an embodiment of the present invention, R4 of Formula 1 as the citrate contained in the citrate composition is hydrogen. If R4 is hydrogen, excellent plasticizing efficiency, migration resistance and light resistance can generally be achieved, and the advantage of maintaining the absorption rate at an appropriate level can be achieved.

[0088] The method for preparing the plasticizer composition according to the embodiment of the present invention is a method known in the art, and any method for preparing the above-mentioned plasticizer composition may be applied without specific limitation.

[0089] For example, a terephthalate ester composition can be prepared by a direct esterification reaction of an isomeric mixture of hexanol and an alcohol mixture of 2-ethylhexanol with terephthalic acid or its anhydride, and a citrate ester composition can be prepared by a direct esterification reaction of citric acid or its anhydride with an isomeric mixture of hexanol.

[0090] In addition, the terephthalate-based composition can be prepared by transesterification of di(2-ethylhexyl)terephthalate with an isomeric mixture of hexanol, and the citrate-based composition can be prepared by transesterification of trihexyl citrate with an isomeric mixture of hexanol.

[0091] The plasticizer composition of the embodiment of the present invention is a material prepared by appropriately performing an esterification reaction, and the preparation method is not particularly limited as long as the above conditions are met, especially controlling the ratio of branched alcohols in the isomer mixture alcohol and containing specific components.

[0092] For example, the direct esterification reaction can be carried out by the following steps: a step of injecting an acid or its derivative and two or more mixed alcohols, adding a catalyst and reacting under a nitrogen atmosphere; a step of removing unreacted raw materials; a step of neutralizing (or deactivating) the unreacted raw materials and the catalyst; and a step of removing (for example, distilling under reduced pressure) impurities and filtering.

[0093] The components of the isomer mixture of hexanol and the weight ratio of each component are the same as above. In the direct esterification reaction, based on 100 mol% of the acid, the alcohol can be used in the range of 150 mol% to 900 mol%, 200 mol% to 700 mol%, 200 mol% to 600 mol%, 250 mol% to 500 mol% or 270 mol% to 400 mol%, and by controlling the amount of the alcohol, the ratio of the components in the final composition can be controlled.

[0094] The catalyst can be, for example, one or more selected from the following substances: acid catalysts such as sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, p-toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid and alkyl sulfates; metal salts such as aluminum lactate, lithium fluoride, potassium chloride, cesium chloride, calcium chloride, ferric chloride and aluminum phosphate; metal oxides such as heteropoly acids; natural / synthetic zeolites; cation and anion exchange resins; and organic metals such as tetraalkyl titanate, and polymers thereof. In a particular embodiment, the catalyst can use tetraalkyl titanate. Preferably, p-toluenesulfonic acid or methanesulfonic acid, etc., as an acid catalyst with a low activation temperature, may be suitable.

[0095] The amount of the catalyst used may vary depending on its type, for example, the amount of the homogeneous catalyst may be 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 a total of 100 wt % of the reactants, and the amount of the heterogeneous catalyst may be 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 the reactants.

[0096] In this case, the reaction temperature may be in the range of 100°C to 280°C, 100°C to 250°C, or 120°C to 230°C.

[0097] In another embodiment, the transesterification reaction may be a reaction of terephthalate or citrate with an alcohol having an alkyl group different from that of terephthalate or citrate. Here, the alkyl groups of the ester and the alcohol may be exchanged.

[0098] The "transesterification reaction" used in the present invention refers to the reaction of an alcohol and an ester to exchange the alkyl group of the ester with the alkyl group of the alcohol.

[0099] The composition ratio of the mixture prepared by the transesterification reaction can be controlled according to the amount of alcohol added. Based on 100 parts by weight of terephthalate or citrate, the amount of alcohol added can be 0.1 to 200 parts by weight, particularly 1 to 150 parts by weight, and more particularly 5 to 100 parts by weight. For reference, the determination of the component ratio in the final composition can be the amount of alcohol added as in the direct esterification reaction.

[0100] According to an embodiment of the present invention, the transesterification reaction can be carried out at a reaction temperature of 120°C to 190°C, preferably 135°C to 180°C, more preferably 141°C to 179°C for 10 minutes to 10 hours, preferably 30 minutes to 8 hours, more preferably 1 to 6 hours. Within this temperature and time range, the composition ratio of the final plasticizer composition can be effectively controlled. In this case, the reaction time can be calculated from the point at which the reaction temperature is reached after the reactant temperature is increased.

[0101] The transesterification reaction may be performed under an acid catalyst or a metal catalyst, and in this case, an effect of reducing the reaction time may be achieved.

[0102] The acid catalyst may include, for example, sulfuric acid, methanesulfonic acid, or p-toluenesulfonic acid, and the metal catalyst may include, for example, an organic metal catalyst, a metal oxide catalyst, a metal salt catalyst, or a metal itself.

[0103] The metal component may be, for example, any one selected from the group consisting of tin, titanium, and zirconium, or a mixture of two or more thereof.

[0104] In addition, after the transesterification reaction, the step of removing unreacted alcohol and reaction byproducts by distillation can be further included. The distillation can be, for example, a two-step distillation, by which the difference in boiling points is utilized to separate alcohol and byproducts. In another embodiment, the distillation can be a mixed distillation. In this case, it is possible to achieve the effect of the ester plasticizer composition being relatively stably ensured with a desired composition ratio. Mixed distillation refers to distilling unreacted alcohol and byproducts simultaneously.

[0105] According to another embodiment of the present invention, a resin composition including the above plasticizer composition and a resin is provided.

[0106] The resin may be any resin known in the art, for example, a mixture of one or more selected from the group consisting of a linear vinyl chloride polymer, a pasty vinyl chloride polymer, an ethylene-vinyl acetate copolymer, an ethylene polymer, a propylene polymer, a polyketone, a polystyrene, a polyurethane, a polylactic acid, a natural rubber, a synthetic rubber, and a thermoplastic elastomer, but not limited thereto.

[0107] 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.

[0108] Generally, a resin using a plasticizer composition may be prepared into a resin product by melt processing or plastisol processing, and a resin by melt processing and a resin from plastisol processing may be variously produced according to various polymerization methods.

[0109] For example, when a vinyl chloride polymer is used in melt processing, solid phase resin particles having a large average particle size are prepared by suspension polymerization or the like and used, and the vinyl chloride polymer is called a linear vinyl chloride polymer. When a vinyl chloride polymer is used in plastisol processing, a sol-state resin as minute resin particles is prepared by emulsion polymerization or the like and used, and the vinyl chloride polymer is called a paste-like vinyl chloride resin.

[0110] In the case of a linear vinyl chloride polymer, the content of the plasticizer may preferably be 5 to 80 parts by weight based on 100 parts by weight of the polymer, and in the case of a paste vinyl chloride polymer, the content of the plasticizer may preferably be 40 to 120 parts by weight based on 100 parts by weight of the polymer.

[0111] The resin composition may further include a filler. The filler may be present in an amount of 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.

[0112] The filler can use fillers known in the art and is not particularly limited. For example, the filler can be a mixture of one or more selected from silicon dioxide, magnesium carbonate, calcium carbonate, hard coal, talc, magnesium hydroxide, titanium dioxide, magnesium oxide, calcium hydroxide, aluminum hydroxide, aluminum silicate, magnesium silicate and barium sulfate.

[0113] In addition, the resin composition may further include other additives such as stabilizers, if necessary. Various other additives such as stabilizers 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.

[0114] As the stabilizer, for example, a calcium-zinc (Ca-Zn) stabilizer such as calcium-zinc complex stearate or a barium-zinc (Ba-Zn) stabilizer may be used, but there are no particular limitations.

[0115] The resin composition can be applied to melt processing and plastisol processing as described above, and calendar processing, extrusion processing, or injection processing can be applied to melt processing, and coating processing or the like can be applied to plastisol processing.

[0116] Example

[0117] Hereinafter, embodiments will be described in detail to specifically illustrate the present invention. However, the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be sufficient and complete, and the scope of the inventive concept will be fully conveyed to those skilled in the art.

[0118] The contents of the components in the isomer mixture of hexanol were analyzed by gas chromatography measurement using a gas chromatography apparatus from Agilent Co. (product name: Agilent 7890GC, column: HP-5, carrier gas: helium (flow rate 2.4 ml / min), detector: FID, injection volume: 1 μl, starting value: 70°C / 4.2 min, final value: 280°C / 7.8 min, program rate: 15°C / min).

[0119] Preparation Example 1: Preparation of terephthalate ester composition

[0120] 498 g of terephthalic acid, 343 g of an isomer mixture of hexanol, 656 g of 2-ethylhexanol and 1.5 g of tetraisopropyl titanate catalyst were injected into a 3-liter four-necked reactor equipped with a cooler, a condenser, a decanter, a reflux pump, a temperature controller and a stirrer, the reaction temperature was set to 220° C., and a direct esterification reaction was carried out for about 8 hours while continuously injecting nitrogen. When the acid value reached 0.1, the reaction was terminated.

[0121] After the reaction is completed, in order to remove the unreacted raw materials, distillation extraction is carried out under reduced pressure. After the distillation extraction, a neutralization process, a dehydration process and a filtration process are carried out to obtain a terephthalate composition containing dihexyl terephthalate, hexyl (2-ethylhexyl) terephthalate and di (2-ethylhexyl) terephthalate.

[0122] In addition to the above composition, various terephthalate ester compositions were prepared by changing the type and composition of the isomers contained in the isomer mixture of hexanol used in the above process, and the composition ratio of the isomer mixture of hexanol to 2-ethylhexanol, and the composition of the isomer mixture of hexanol used in each case, and the composition ratio of the isomer mixture of hexanol to 2-ethylhexanol are summarized in the following Table 1. Meanwhile, in this preparation example, "hexyl" is a general expression referring to all hexyl groups having various structures derived from the isomer mixture of hexanol.

[0123] Table 1

[0124]

[0125] Preparation Example 2: Preparation of citrate ester composition

[0126] Into a 3-liter four-necked reactor equipped with a cooler, a condenser, a decanter, a reflux pump, a temperature controller and a stirrer, 384 g of citric acid, 857 g of an isomer mixture of hexanol and 1.5 g of tetraisopropyl titanate catalyst were injected, the reaction temperature was set to 200° C., and a direct esterification reaction was carried out for about 8 hours while continuously injecting nitrogen. When the acid value reached 1, the reaction was terminated.

[0127] After the reaction is completed, in order to remove the unreacted raw materials, distillation extraction is performed under reduced pressure. After the distillation extraction, a neutralization process, a dehydration process and a filtration process are performed to obtain a citric acid ester composition containing trihexyl citrate.

[0128] In addition to this composition, various citrate-based compositions were prepared by changing the types of isomers contained in the isomer mixture of hexanol used in the process and the composition of each isomer, and the composition of the isomer mixture of hexanol used in each case is summarized in the following Table 2. Meanwhile, in this preparation example, "hexyl" is a general expression referring to all hexyl groups having various structures derived from the isomer mixture of hexanol.

[0129] Table 2

[0130]

[0131] Example

[0132] The terephthalate ester composition and the citrate ester composition prepared above were mixed in a specific weight ratio to prepare a plasticizer composition. The types of the terephthalate ester composition and the citrate ester composition used in each example and the weight ratio therebetween are summarized in Table 3 below.

[0133] Table 3

[0134]

[0135] Comparative Examples 1 to 4

[0136] Four common plasticizers were used as Comparative Examples 1 to 4. Dioctyl phthalate (DOP) was used as Comparative Example 1, diisononyl phthalate (DINP) was used as Comparative Example 2, di(2-ethylhexyl) terephthalate (product name: GL300, manufacturer: LG Chem) was used as Comparative Example 3, and a mixture of di(2-ethylhexyl) terephthalate, butyl (2-ethylhexyl) terephthalate, and dibutyl terephthalate (product name: GL500, manufacturer: LgChem) was used as Comparative Example 4.

[0137] Comparative Examples 5 and 6

[0138] The terephthalate-based composition prepared in Preparation Example 1-5 was used as the only plasticizer in Comparative Example 5, and the citrate-based composition prepared in Preparation Example 2-1 was used as the only plasticizer in Comparative Example 6.

[0139] Experimental Example 1: Sheet Performance Evaluation

[0140] By using the plasticizers of Examples and Comparative Examples, samples were manufactured according to ASTM D638 and the following formulations and manufacturing conditions.

[0141] (1) Formulation: 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)

[0142] (2) Mixing: Mix at 98°C and 700 rpm

[0143] (3) Preparation of samples: 1T, 2T and 3T sheets were prepared by treatment at 160°C for 4 minutes by a roll mill and by treatment at 180°C for 2.5 minutes (low pressure) and 2 minutes (high pressure) by a press.

[0144] (4) Test items

[0145] 1) Hardness: Shore hardness at 25° C. (Shore “A” and “D”) was measured for 10 seconds using a 3T test specimen using ASTM D2240. If the value is small, the plasticization efficiency is evaluated to be excellent.

[0146] 2) Tensile strength: The sample was stretched at a crosshead speed of 200 mm / min using a UTM (manufacturer: Instron, model: 4466) by ASTM D638 method, and the point at which the 1T sample was cut was measured. The tensile strength was calculated as follows:

[0147] Tensile strength (kgf / cm 2 ) = load value (kgf) / thickness (cm) × width (cm)

[0148] 3) Elongation measurement: According to the ASTM D638 method, the sample is stretched using UTM at a crosshead speed of 200 mm / min, and the point where the 1T sample is cut is measured. The elongation is calculated as follows:

[0149] Elongation (%) = elongated length / initial length × 100

[0150] 4) Migration loss measurement: According to KSM-3156, a sample with a thickness of 2 mm or more was obtained, glass plates were attached to both sides of the 1T sample, and 1 kgf / cm 2 The sample was placed in a hot air circulation oven (80°C) for 72 hours, then taken out and cooled at room temperature for 4 hours. Then, the glass plates attached to both sides of the sample were removed, the weights of the glass plates and the sample plate before and after being placed in the oven were measured, and the migration loss was calculated as follows.

[0151] Migration loss (%) = {[(initial weight of sample at room temperature) - (weight of sample after standing in oven] / (initial weight of sample at room temperature)} × 100

[0152] 5) Volatilization loss measurement: The manufactured sample was treated at 80° C. for 72 hours, and then the weight of the sample was measured.

[0153] Volatilization loss (weight %) = (initial sample weight) - (sample weight after 80°C treatment for 72 hours) / (initial sample weight) × 100

[0154] 6) Stress test (stress resistance): A sample with a thickness of 2 mm in a bent state was left at 23° C. for 168 hours, and the degree of migration (degree of exudation) was observed. The result was recorded as a numerical value, and if the number was close to 0, it showed excellent properties.

[0155] 7) Absorption rate measurement

[0156] The absorption rate was evaluated by measuring the time taken to mix the resin and the ester compound using a planetary mixer (Brabender, P600) under the conditions of 77° C. and 60 rpm until the torque of the mixer stabilized.

[0157] The evaluation results of the test items of Examples and Comparative Examples are summarized in Tables 4 and 5 below.

[0158] Table 4

[0159]

[0160] Table 5

[0161] distinguish Stress testing Absorption rate (min:sec) Example 1-1 0.5 5:45 Example 1-2 0.5 5:50 Examples 1-3 0.5 5:50 Examples 1-4 0.5 5:35 Examples 1-5 0.5 5:50 Example 2-1 0.0 4:20 Example 2-2 0.5 6:00 Example 2-3 1.0 6:20 Example 3-1 0.5 5:50 Example 3-2 0.5 5:45 Example 4-1 0.5 5:55 Example 4-2 0.5 5:55 Example 4-3 0.5 6:00 Example 4-4 0.5 6:00 Comparative Example 1 0.5 5:30 Comparative Example 2 0.5 6:50 Comparative Example 3 3.0 7:30 Comparative Example 4 1.5 5:30 Comparative Example 5 1.5 6:00 Comparative Example 6 0.5 5:55

[0162] Referring to the results in Tables 4 and 5, it can be confirmed that the plasticizer composition according to the embodiment of the present invention shows the same or better plasticizing efficiency, as well as excellent effects in mechanical properties, migration resistance and thermal stability, compared with the plasticizer compositions of Comparative Examples 1 to 4 which are conventional plasticizer products.

[0163] In particular, Comparative Examples 1 and 2 are the most commonly used phthalate plasticizer products, and the examples of the present invention show similar levels of plasticizing efficiency as Comparative Example 1 and improved mechanical properties such as tensile strength and elongation compared to Comparative Example 1. In addition, in contrast to Comparative Example 2, the examples of the present invention show improved plasticizing efficiency and elongation, as well as similar results for the remaining physical properties. Considering that the plasticizer products of Comparative Examples 1 and 2 are not currently easy to use due to environmental regulations, it can be confirmed that the plasticizer compositions of the examples of the present invention can be fully used as environmentally friendly alternatives to conventional plasticizer products.

[0164] In addition, Comparative Examples 3 and 4 are environmentally friendly plasticizers for replacing Comparative Examples 1 and 2, and it can be confirmed that the plasticizer compositions of Comparative Examples 3 and 4 show significantly reduced migration resistance and stress resistance compared with the plasticizer compositions of the embodiments of the present invention. If the migration resistance and stress resistance are poor as in Comparative Examples 3 and 4, there is a fatal defect that the plasticizer mixed in the resin composition may be easily dissolved and harm the human body.

[0165] Comparative Examples 5 and 6 used any one of the terephthalate composition and the citrate composition as the plasticizer composition of the embodiments of the present invention, and the case of Comparative Example 5 using only the terephthalate composition showed poor results in terms of plasticization efficiency, elongation, and migration loss compared to the embodiments; the case of Comparative Example 6 using only the citrate composition showed significantly poor tensile strength compared to the embodiments, and showed a defect that the plasticized product may be easily broken. In particular, if Example 4-4 in which the terephthalate composition and the citrate composition were mixed at a weight ratio of 9:1 was compared with Comparative Example 5 using only the terephthalate composition, it was confirmed that Comparative Example 5 showed significant deterioration in tensile strength and a large increase in migration loss, thereby confirming that even if a small amount of the citrate composition is included in the plasticizer composition, mechanical properties and migration resistance can be improved.

[0166] From the above results, it can be confirmed that if a terephthalate ester composition and a citrate ester composition are used in combination, a derivative from an isomer mixture of hexyl alcohol is used as the alkyl group of the terephthalate ester composition and the citrate ester composition, and a hexyl group and a 2-ethylhexyl group are used as the alkyl group of the terephthalate ester composition, environmental friendliness and performance equal to or better than that of conventional plasticizer products can be achieved, and conventional plasticizer products can be successfully replaced.

[0167] Experimental Example 2: Evaluation of carbonization properties

[0168] Using the plasticizer compositions of Examples 1-5 and Comparative Examples 1 to 6, samples with a size of 40 cm×40 cm and a thickness of 0.25 mm were manufactured under the same conditions as in Experimental Example 1. For the manufactured samples, a carbonization test was performed in a Mathis oven at 230° C. at a rate of 5 mm / 10 seconds, and the results are shown in Figure 1 middle.

[0169] If through Figure 1 It was confirmed that the plasticizer compositions of Examples 1 to 5 of the present invention showed excellent carbonization properties similar to those of conventional plasticizer products, but the plasticizer composition of Comparative Example 6 using only citrate esters showed extremely poor carbonization properties. This means that discoloration occurs due to poor thermal stability of the citrate ester compound itself when exposed to high temperatures, and it can be confirmed that the plasticizer composition of the present invention overcomes this defect of the citrate ester compound itself by mixing with terephthalate ester.

Claims

1. A plasticizer composition comprising a terephthalate ester composition and a citrate ester composition, wherein: The terephthalate composition comprises 0.5 wt % to 50.0 wt % of dihexyl terephthalate, 3.0 wt % to 70.0 wt % of hexyl (2-ethylhexyl) terephthalate, and 0.5 wt % to 95.0 wt % of di(2-ethylhexyl) terephthalate, The citrate ester composition comprises trihexyl citrate, The hexyl group of the terephthalate and the hexyl group of the citrate are derived from an isomeric mixture of hexanol, and The isomer mixture of hexanol includes two or more selected from the group consisting of 1-hexanol, 1-methylpentanol, 2-methylpentanol, 3-methylpentanol, 4-methylpentanol, 1,1-dimethylbutanol, 1,2-dimethylbutanol, 1,3-dimethylbutanol, 2,2-dimethylbutanol, 2,3-dimethylbutanol, 3,3-dimethylbutanol, 1-ethylbutanol, 2-ethylbutanol, 3-ethylbutanol and cyclopentylmethanol.

2. The plasticizer composition according to claim 1, wherein The citrate composition comprises one or more citrates of the following formula 1: [Formula 1] In Formula 1, R1 to R3 are each independently a n-hexyl group, a branched hexyl group or a cyclopentylmethyl group, and R4 is hydrogen.

3. The plasticizer composition according to claim 1, wherein The weight ratio of the terephthalate ester composition to the citrate ester composition is 95:5 to 5:

95.

4. The plasticizer composition according to claim 1, wherein The weight ratio of the terephthalate ester composition to the citrate ester composition is 95:5 to 50:

50.

5. The plasticizer composition according to claim 1, wherein The isomeric mixture of hexanol comprises 2-methylpentanol and 3-methylpentanol.

6. The plasticizer composition according to claim 1, wherein The isomer mixture includes 40 parts by weight or more of a branched alcohol based on 100 parts by weight of the isomer mixture of hexanol.

7. The plasticizer composition according to claim 1, wherein The isomer mixture includes 50 to 95 parts by weight of a branched alcohol based on 100 parts by weight of the isomer mixture of hexanol.

8. The plasticizer composition according to claim 5, wherein The isomeric mixture of hexanol further comprises 1-hexanol.

9. The plasticizer composition according to claim 8, wherein The isomer mixture includes 40 parts by weight or less of 1-hexanol based on 100 parts by weight of the isomer mixture of hexanol.

10. The plasticizer composition according to claim 5 or 8, wherein The isomeric mixture of hexanol also contains 4-methylpentanol.

11. The plasticizer composition according to claim 5 or 8, wherein The isomeric mixture of hexanol also contains cyclopentylmethanol.

12. The plasticizer composition according to claim 11, wherein The isomer mixture includes 20 parts by weight or less of cyclopentylmethanol based on 100 parts by weight of the isomer mixture of hexanol.

13. A resin composition comprising: 100 parts by weight of 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 one or more selected from the group consisting of linear vinyl chloride polymers, pasty vinyl chloride polymers, ethylene polymers, propylene polymers, polyketones, polystyrenes, polyurethanes, polylactic acid, natural rubbers, and synthetic rubbers.

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