Resin composition, method for producing the same, polyester sheet, and polyester film

Abstract

A resin composition and a method for manufacturing the same, a polyester sheet, and a polyester film are provided. The resin composition comprises a polyester resin containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols, and the content of 2-methyl-1,3-dioxolane as an impurity is less than 10 ppm by weight.

Description

Technical Field

[0001] The invention relates to a resin composition and a method for manufacturing the same, as well as polyester sheets and polyester films. Background Technology

[0002] Polyester resin refers to a polymer resin with ester functional groups on its main chain. It is used in various industrial fields for packaging, displays, insulation materials, and many other applications.

[0003] As a representative example of polyester resin, polyethylene terephthalate (PET) resin, which is produced by the reaction of terephthalic acid (TPA) and ethylene glycol (EG), can be cited.

[0004] However, the main raw material for terephthalic acid is paraxylene, which is produced by refining crude oil. Therefore, the manufacture and use of terephthalic acid can lead to the depletion of crude oil resources. Furthermore, the decomposition of terephthalic acid increases carbon dioxide emissions, which can cause environmental pollution and contribute to climate change, such as global warming.

[0005] Therefore, there has been ongoing effort to replace terephthalic acid with 2,5-furandicarboxylicacid (FDCA) in the manufacture of polyester resins. FDCA is derived from biomass, which can help prevent the depletion of crude oil resources and minimize environmental pollution and climate change due to its biodegradability. Summary of the Invention

[0006] [Technical Issues]

[0007] One implementation aims to provide a resin composition that can be manufactured using environmentally friendly methods and is able to suppress the generation of volatile substances, i.e., impurities, thereby improving the optical properties and color realization properties of polyester sheets and polyester films.

[0008] [Technical Solution]

[0009] In one embodiment, a resin composition is provided comprising a polyester resin containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols, and

[0010] The content of 2-methyl-1,3-dioxolane as an impurity is less than 10 ppm by weight.

[0011] In another embodiment, a method for manufacturing a resin composition is provided, comprising: preparing a composition comprising a polyester resin containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols, wherein the content of 2-methyl-1,3-dioxolane, an impurity generated by light or heat in the polyester resin is adjusted to less than 10 ppm by weight in the composition.

[0012] In yet another implementation, a polyester sheet is provided comprising the aforementioned resin composition.

[0013] In yet another embodiment, a polyester film is provided comprising the aforementioned resin composition.

[0014] [Invention Effects]

[0015] One implementation provides a resin composition that can be manufactured using environmentally friendly methods and is able to suppress the generation of volatile substances, i.e., impurities, thereby improving the optical properties and color realization properties of polyester sheets and polyester films. Detailed Implementation

[0016] The following detailed description of specific implementation examples enables those skilled in the art to easily implement the invention. However, the present invention can be implemented in various different forms and is not limited to the implementation examples described herein.

[0017] The terminology used herein is merely illustrative of exemplary implementations and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0018] When a part is referred to as "including" a constituent element, it means, unless otherwise stated otherwise, that other constituent elements may also be included, rather than excluding other constituent elements.

[0019] As used in this specification, the term "moiety" refers to a portion or unit of a particular compound that is derived from that compound when it participates in a chemical reaction and is included in the products of that chemical reaction. More specifically, "moiety" derived from furan dicarboxylic acids and "moiety" derived from alkylene glycols refer to portions derived from furan dicarboxylic acids and portions derived from alkylene glycols, respectively.

[0020] Unless otherwise stated, the term "alkyl" as used in this specification refers to a saturated aliphatic hydrocarbon, including straight-chain and branched chains, having a specific number of carbon atoms (i.e., carbon number). For example, the aforementioned alkyl may typically be C1 to C10 (i.e., having 1 to 10 carbon atoms) alkyl, such as C1 to C8 alkyl, C1 to C5 alkyl, or C1 to C3 alkyl. Examples of the aforementioned alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, etc.

[0021] The foregoing description of "alkyl" also applies to monovalent aliphatic hydrocarbons, specifically "alkyl" and divalent "alkylene". On the other hand, the aforementioned "alkyl" or "alkyl" including "alkylene" can be substituted with additional substituents or remain unsubstituted; the description of "substitution" applies as described below. As an example, the aforementioned alkyl can be substituted with more than one halogen atom, up to the total number of hydrogen atoms present on the alkyl residue. As an example, C1 to C4 alkyl can be alkyl with or without halogen atoms substituted, for example, C1 to C4 alkyl can be substituted with or without fluorine (F), and representative examples include trifluoromethyl (-CF3) or difluoroethyl (-CH2CHF2), etc.

[0022] The alkyl group described herein as being substituted may be replaced by more than one substituent, unless otherwise stated, the substituents being chosen independently. The total number of substituents is the same as the total number of hydrogen atoms on the alkyl residue, up to a degree that satisfies chemigenicity. The substituted alkyl group may typically contain 1 to 6 arbitrary substituents, usually 1 to 5 arbitrary substituents, preferably 1 to 4 arbitrary substituents, and more preferably 1 to 3 arbitrary substituents.

[0023] "Substitution" can mean that at least one hydrogen atom is substituted by a halogen atom (F, Cl, Br, I), a hydroxyl group or a salt thereof, a C1 to C20 alkoxy group, a nitro group, a cyano group, an amino group, an imino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamoyl group, a thiol group or a salt thereof, a thioether group, an ester group, an ether group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C1 to C10 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C20 aryl group, a C3 to C20 cycloalkyl group, a C3 to C20 cycloalkenyl group, a C3 to C20 cycloalkynyl group, a C2 to C20 heterocyclic alkyl group, a C2 to C20 heterocyclic alkenyl group, a C2 to C20 heterocyclic alkynyl group, a C3 to C20 heteroaryl group, or a combination thereof. Alternatively, as an example, the term "substitution" may mean that at least one hydrogen atom is substituted by a halogen atom, a C1 to C10 alkyl group, a C6 to C20 aryl group, a C3 to C20 heteroaryl group, or a combination thereof.

[0024] In this specification, CIE1976 L a b The color system corresponds to the color space defined by the CIE (International Commission on Illumination), which has now become a global standard. This CIE 1976 L... a b In color space, L The value represents lightness in a color coordinate system, ranging from 0 to 100. A value of 0 represents pure black, and a value of 100 represents pure white. This indicates whether the value leans towards red or green; a positive "+" value indicates red, and a negative "-" value indicates green. This indicates whether the value leans towards yellow or blue. A positive value "+" indicates yellow, and a negative value "-" indicates blue.

[0025] Based on the definitions described above, implementation examples of the present invention will be described in detail. However, these are merely examples, and the present invention is not limited thereto, and is defined only by the scope of the claims described below.

[0026] Resin Composition

[0027] One embodiment provides a resin composition comprising a polyester resin containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols, wherein the content of 2-methyl-1,3-dioxolane as an impurity is less than 10 ppm by weight.

[0028] With the increasing demand for environmentally friendly polyester resins, a manufacturing technology is being developed to produce polyester resins by reacting furan dicarboxylic acid compounds, which are derived from biomass, with alkylene glycol compounds. This type of polyester resin offers several advantages: using furan dicarboxylic acid compounds, derived from biomass, instead of terephthalic acid compounds, which are derived from crude oil, as a raw material helps prevent the depletion of crude oil resources; furthermore, the resulting polyester resin exhibits biodegradability, making it environmentally friendly.

[0029] However, when polyester resins made from furan dicarboxylic acid compounds are formed into chips and stored, exposure to sunlight or high temperatures can easily lead to the formation of byproducts such as 2-methyl-1,3-dioxolane within the chips. These byproducts are volatile substances and may be inhaled, raising concerns about their potential adverse effects on the optical properties of films produced through high-temperature post-processing. Furthermore, furan dicarboxylic acid compounds used as raw materials for polyester resin manufacturing exhibit low thermal stability, causing the resulting polyester resins to yellow or brown, resulting in lower brightness and posing a disadvantage in achieving color accuracy in products utilizing them.

[0030] In one implementation, the aim is to improve the physical properties of the resin composition and the polyester film by controlling the generation of impurities such as 2-methyl-1,3-dioxolane that occur when a polyester resin containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols is exposed to sunlight or high temperatures, to a specific level.

[0031] One embodiment of the resin composition comprises a polyester resin containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols. In this case, the polyester resin has, for example, […]. (in, The terminal groups of the diol chain (indicating the bonding position) serve as the terminal groups of the main chain, but if exposed to sunlight or high temperatures, they undergo a decomposition reaction, breaking down into carboxyl terminal groups and acetaldehyde. Acetaldehyde reacts with alkylene glycols, which are raw materials for polyester resins, readily producing impurities such as 2-methyl-1,3-dioxolane. However, these impurities may be inhaled by the human body, and there are concerns about their adverse effects on the optical properties of polyester resins, or on the optical properties or color realization of polyester films obtained through subsequent processing.

[0032] Therefore, one embodiment of the resin composition is characterized by a low content of 2-methyl-1,3-dioxolane, which is an impurity, at 10 ppm or less (including 0 ppm) by weight (i.e., in the total weight of the resin composition). By meeting this condition, the amount of volatile substances that may be harmful to human health can be reduced, and the degradation of the physical properties of the resin composition and the polyester film caused by the aforementioned substances can be prevented. This not only improves the purity of the polyester resin in the resin composition itself, thereby enhancing optical properties, but also contributes to the realization of the optical properties and color of the polyester film produced therefrom.

[0033] In the above resin composition, 2-methyl-1,3-dioxolane exists as an impurity, and the lower the impurity content, the more preferred; therefore, there is no particular limitation on the lower limit of its content. In particular, it is preferred that the above resin composition does not contain impurities, and therefore, the case where the content of the above-mentioned 2-methyl-1,3-dioxolane is 0 ppm by weight is also included.

[0034] As an example, in the above-described resin composition, the content of 2-methyl-1,3-dioxolane by weight can be less than 5 ppm, for example, less than 4.1 ppm, less than 2.5 ppm, less than 2 ppm, or less than 1.4 ppm. As an example of the lower limit of the content of 2-methyl-1,3-dioxolane, it can be 0.1 ppm. Within this range, the inherent physical properties of the above-described resin composition can be further improved, and the optical properties and color effects of the polyester film can be maximized.

[0035] According to one embodiment, the above-described resin composition may further contain a hydrazine additive. In this case, the hydrazine additive preferentially reacts with acetaldehyde produced when the polyester resin decomposes under sunlight or high temperatures. Because this hydrazine additive participates in the reaction with acetaldehyde, it helps to suppress the formation of the aforementioned 2-methyl-1,3-dioxolane as an impurity.

[0036] For example, the resin composition described above may further contain additives represented by Chemical Formula 1A, Chemical Formula 1B, or combinations thereof as the aforementioned hydrazine additives. When using such hydrazine additives, acetaldehyde generated during the decomposition of the polyester resin can react effectively with the aforementioned hydrazine additives, and the content of 2-methyl-1,3-dioxolane as an impurity can be minimized. Therefore, when using the aforementioned hydrazine additives, the heat-induced yellowing or browning of the polyester resin can be effectively suppressed, thereby further improving the optical properties and color performance of the polyester film.

[0037] [Chemical Formula 1A]

[0038] [Chemical Formula 1B]

[0039] In the above chemical formula 1A, R1 to R4 are each independently hydrogen, or substituted or unsubstituted C1 to C5 alkyl groups, and X is carbonic acid, hydrochloric acid, sulfuric acid, nitric acid, or a combination thereof. In the above chemical formula 1B, X1 to X4 are each independently S, O, NR5, R5 is hydrogen, or a substituted or unsubstituted C1 to C5 alkyl group, Y1 - and Y2 - Each independently is -SO3 - -Cl - Or a combination of them, Z + NH4 + .

[0040] As an example, the above-mentioned resin composition may also contain additives represented by the following chemical formula 2A, additives represented by the following chemical formula 2B, or combinations thereof as the aforementioned hydrazine additives.

[0041] [Chemical Formula 2A]

[0042] [Chemical Formula 2B]

[0043] In the above chemical formula 2A, R1 to R4 are each independently hydrogen, or substituted or unsubstituted C1 to C5 alkyl groups, and X is carbonic acid, hydrochloric acid, sulfuric acid, nitric acid, or a combination thereof. In the above chemical formula 2B, R5 and R6 are each independently hydrogen, or substituted or unsubstituted C1 to C5 alkyl groups, Z + NH4 + .

[0044] As an example, the above-mentioned resin composition may also contain additives represented by the following chemical formula 3A, additives represented by the following chemical formula 3B, or combinations thereof as the aforementioned hydrazine additives.

[0045] [Chemical Formula 3A]

[0046] [Chemical Formula 3B]

[0047] In the above chemical formula 3A, R1 to R4 are each independently hydrogen, or substituted or unsubstituted C1 to C5 alkyl groups. In the above chemical formula 3B, R5 and R6 are each independently hydrogen, or substituted or unsubstituted C1 to C5 alkyl groups.

[0048] As an example, the above-mentioned resin composition may also contain additives represented by the following chemical formula 4A, additives represented by the following chemical formula 4B, or combinations thereof as the aforementioned hydrazine additives.

[0049] [Chemical Formula 4A]

[0050] [Chemical Formula 4B]

[0051] According to one implementation example, relative to 100% by weight of the above-described resin composition, 0.001% by weight to 0.01% by weight of the aforementioned hydrazine additive may be included. Within this range, without causing changes in the physical properties of the polyester resin due to the use of hydrazine additives, the optical and viscosity properties of the resin composition can be improved, and it is more conducive to ensuring the optical properties and color realization effect of the polyester film.

[0052] In one implementation, R1 to R4 may each be independently hydrogen, or a substituted or unsubstituted C1 to C3 alkyl group. Alternatively, R1 to R4 may each be independently hydrogen, or a substituted or unsubstituted C1 or C2 alkyl group. Alternatively, R1 to R4 may each be independently hydrogen, or an unsubstituted C1 or C2 alkyl group.

[0053] As an example, R5 and R6 can each be independently hydrogenated, or substituted or unsubstituted C1 to C3 alkyl groups. Alternatively, R5 and R6 can each be independently hydrogenated, or substituted or unsubstituted C1 or C2 alkyl groups. Alternatively, R5 and R6 can each be independently hydrogenated, or unsubstituted C1 or C2 alkyl groups.

[0054] The aforementioned polyester resin can be produced through a series of steps including esterification of furan dicarboxylic acid compounds with alkylene glycol compounds, prepolymerization, and polycondensation. The specific method for manufacturing the polyester resin can be any conventional method. The residues derived from furan dicarboxylic acid compounds and residues derived from alkylene glycol compounds are described in detail below.

[0055] Residues derived from furan dicarboxylic acid compounds

[0056] The aforementioned polyester resin contains residues derived from furan dicarboxylic acid compounds (hereinafter, 'residues derived from furan dicarboxylic acid compounds'), and exhibits excellent biodegradability due to the furan dicarboxylic acid compounds.

[0057] The above-mentioned furan dicarboxylic acid compounds can be represented by the following chemical formula 11A.

[0058] [Chemical Formula 11A]

[0059] In the above chemical formula 11A, L1 and L2 are each independently a single bond, or a substituted or unsubstituted C1 to C10 alkylene group.

[0060] As an example, in the above chemical formula 11A, L1 and L2 can each be independently a single-bonded, substituted, or unsubstituted C1 to C8 alkylene group. Alternatively, in the above chemical formula 11A, L1 and L2 can each be independently a single-bonded, substituted, or unsubstituted C1 to C5 alkylene group. Alternatively, in the above chemical formula 11A, L1 and L2 can each be independently a single-bonded, substituted, or unsubstituted C1 to C3 alkylene group.

[0061] As a representative example, the above-mentioned furan dicarboxylic acid compounds can be 2,5-furandicarboxylic acid, in which case both L1 and L2 of the above chemical formula 11A can be single bonds.

[0062] The residues derived from furan dicarboxylic acid compounds can be represented by the following chemical formula 11B.

[0063] [Chemical Formula 11B]

[0064] In the above chemical formula 11B, L1 and L2 are each independently a single bond, or a substituted or unsubstituted C1 to C10 alkylene group. Indicates the bonding location.

[0065] As an example, in the above chemical formula 11B, L1 and L2 can each independently be a single-bonded, substituted, or unsubstituted C1 to C8 alkylene group. Alternatively, in the above chemical formula 11B, L1 and L2 can each independently be a single-bonded, substituted, or unsubstituted C1 to C5 alkylene group. Alternatively, in the above chemical formula 11B, L1 and L2 can each independently be a single-bonded, substituted, or unsubstituted C1 to C3 alkylene group.

[0066] As a representative example, the above-mentioned furan dicarboxylic acid compounds can be 2,5-furandicarboxylic acid, in which case both L1 and L2 of the above chemical formula 11B can be single bonds.

[0067] Residues derived from alkylene glycols

[0068] The aforementioned polyester resin contains residues derived from alkylene glycol compounds (hereinafter, 'residues derived from alkylene glycol compounds'), and exhibits excellent compatibility and elongation properties due to the aforementioned residues derived from alkylene glycol compounds.

[0069] The aforementioned alkylene glycol compounds can be represented by the following chemical formula 21A.

[0070] [Chemical Formula 21A]

[0071] In the above chemical formula 21A, L3 and L4 are each independently substituted or unsubstituted C1 to C10 alkylene groups.

[0072] As an example, in the above chemical formula 21A, L3 and L4 can each independently be a single-bonded, substituted, or unsubstituted C1 to C8 alkylene group. Alternatively, in the above chemical formula 21A, L3 and L4 can each independently be a single-bonded, substituted, or unsubstituted C1 to C5 alkylene group. Alternatively, in the above chemical formula 21A, L3 and L4 can each independently be a single-bonded, substituted, or unsubstituted C1 to C3 alkylene group.

[0073] As a representative example, the aforementioned alkylene glycol compounds can be ethylene glycol. In this case, in the aforementioned chemical formula 21A, L3 can be a C1 alkylene (i.e., methylene) and L4 can be a C1 alkylene (i.e., methylene).

[0074] The residues derived from the above-mentioned alkylene glycol compounds can be represented by the following chemical formula 21B.

[0075] [Chemical Formula 21B]

[0076] In the above chemical formula 21B, L3 and L4 are each independently a substituted or unsubstituted C1 to C10 alkylene group. Indicates the bonding location.

[0077] As an example, in the above chemical formula 21B, L3 and L4 can each be independently substituted or unsubstituted C1 to C8 alkylene groups. Alternatively, in the above chemical formula 21B, L3 and L4 can each be independently substituted or unsubstituted C1 to C5 alkylene groups. Alternatively, in the above chemical formula 21B, L3 and L4 can each be independently substituted or unsubstituted C1 to C3 alkylene groups.

[0078] As a representative example, the aforementioned alkylene glycol compounds can be ethylene glycol. In this case, in the above chemical formula 21B, L3 can be a C1 alkylene (i.e., methylene) and L4 can be a C1 alkylene (i.e., methylene).

[0079] In the aforementioned polyester resin, the molar ratio of the residues derived from furan dicarboxylic acids to the residues derived from alkylene glycol compounds can be 9:1 to 1:9, 8:2 to 2:8, or 1:1 to 1:2. Within this range, the effects of the residues derived from furan dicarboxylic acids and the residues derived from alkylene glycol compounds can be coordinated and ensured.

[0080] The aforementioned polyester resin can be an alternating copolymer, a random copolymer, or a block copolymer.

[0081] In one implementation example, the aforementioned polyester resin can be represented by the following chemical formula 31A.

[0082] [Chemical Formula 31A]

[0083] In the above chemical formula 31A, the definitions of each substituent are as described above.

[0084] As an example, the aforementioned polyester resin can be represented by the following chemical formula 31B.

[0085] [Chemical Formula 31B]

[0086] As a representative example, the polyester resin represented by the above chemical formula 31A corresponds to the following situation: the residues derived from furan dicarboxylic acid compounds are residues derived from furan dicarboxylic acid, the residues derived from ethylene glycol compounds are residues derived from ethylene glycol, and the molar ratio of the residues derived from ethylene glycol to the residues derived from ethylene glycol is 1:1. For example, the above polyester resin can be poly(ethylene furandicarboxylate); PEF.

[0087] The number-average molecular weight (Mn) of the aforementioned polyester resin can be 20,000 g / mol or more, 21,000 g / mol or more, 22,000 g / mol or more, 23,000 g / mol or more, or 24,000 g / mol or more. Alternatively, the number-average molecular weight (Mn) of the aforementioned polyester resin can be 40,000 g / mol or less, 35,000 g / mol or less, or 32,000 g / mol or less. When the number-average molecular weight of the aforementioned polyester resin composition meets the above-mentioned ranges, suitable viscosity can be ensured, and film-forming processing can be easily performed.

[0088] The weight-average molecular weight (Mw) / number-average molecular weight (Mn) ratio of the aforementioned polyester resin, i.e., the molecular weight distribution (MWD), can be 1 or more, 1.2 or more, 1.4 or more, or 1.5 or more. Furthermore, the weight-average molecular weight (Mw) / number-average molecular weight (Mn) ratio of the aforementioned polyester resin, i.e., the molecular weight distribution (MWD), can be 2.5 or less, 2 or less, 1.95 or less, or 1.92 or less. When these conditions are met, the advantage is that not only is process control easier, but the uniform molecular weight distribution also reduces the product defect rate.

[0089] As an example, the above-mentioned resin composition is in accordance with CIE 1976 L a b L in color scheme The value can be between 58.0 and 75.5, for example, it can be between 58.99 and 75.5, 60.0 and 75.5, or 60.12 and 75.12. The above L... The higher the value of L, the closer the color is to white. Therefore, when the above L is satisfied... Under certain conditions, polyester sheets, polyester films, and processed products with excellent transmittance can be obtained.

[0090] As an example, the above-described resin composition is in accordance with CIE 1976 L a b b in color system The value can range from 7.0 to 15.0, for example, it can be from 7.14 to 14.34 or from 13.0 to 14.12. (Referring to b above) The lower the value, the lighter the yellow and the darker the blue. Therefore, when the above b is satisfied... Under certain conditions, polyester sheets and films can be obtained that exhibit reduced heat discoloration and a light yellow color.

[0091] In one implementation example, the intrinsic viscosity (Ⅳ) of the above-mentioned resin composition can be from 0.6 dl / g to 0.8 dl / g, for example, from 0.64 dl / g to 0.8 dl / g or from 0.64 dl / g to 0.66 dl / g. When this condition is met, polyester sheets with excellent processability can be obtained. Specifically, when the intrinsic viscosity (Ⅳ) is less than 0.6 dl / g, the additional solid-state polymerization required to achieve the intrinsic viscosity of 0.8 dl / g or higher for bottle manufacturing consumes a significant amount of time, potentially negatively impacting production efficiency. Furthermore, when the intrinsic viscosity (Ⅳ) exceeds 0.8 dl / g, it cannot be discharged in large quantities from the reactor's internal walls, potentially negatively impacting production yield. Therefore, precise control of the intrinsic viscosity (Ⅳ) is necessary.

[0092] At this point, the intrinsic viscosity (IV) of the above resin composition can be measured using an Ostwald viscometer at 25°C. Alternatively, 0.5 g of the above resin composition and 10 ml of a solution prepared by mixing phenol and tetrachloroethane in a 1:1 volume ratio can be placed in a 20 ml vial, completely dissolved in an oil bath at 100°C, and then the intrinsic viscosity (IV) can be measured using an Ostwald viscometer at 25°C.

[0093] In the above resin composition, except for impurities including 2-methyl-1,3-dioxolane, the remaining portion may be polyester resin.

[0094] Method for manufacturing resin composition

[0095] One embodiment provides a method for manufacturing a resin composition, comprising: preparing a composition comprising a polyester resin containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols, wherein the content of 2-methyl-1,3-dioxolane, an impurity generated by light or heat in the polyester resin is adjusted to below 10 ppm by weight in the composition.

[0096] The aforementioned manufacturing method pertains to the manufacturing method of a resin composition as an example. Therefore, the following description of the resin composition, which is repeated in the foregoing, will be omitted, and the manufacturing process of the resin composition as an example will be described in detail.

[0097] First, a composition comprising a polyester resin containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols is prepared. The aforementioned polyester resin, which is a commercially available product containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols, can be used, or a product prepared by conventional methods known in the art.

[0098] In one implementation example, the manufacture of the aforementioned polyester resin may include: subjecting a monomer mixture comprising a furan dicarboxylic acid compound and an alkylene glycol compound to an esterification reaction, prepolymerizing the product of the esterification reaction, and polycondensing the prepolymerized product. The descriptions of the furan dicarboxylic acid compound and the alkylene glycol compound are the same as those described above; the various stages of the esterification reaction, prepolymerization reaction, and polycondensation reaction are described in detail below.

[0099] In one embodiment of the method for manufacturing a resin composition, a monomer mixture comprising a furan dicarboxylic acid compound and an alkylene glycol compound may be subjected to an esterification reaction. During this stage, oligomers with a low degree of polymerization may be formed.

[0100] The monomer mixture in the above-mentioned esterification reaction stage may contain 100 to 200 moles of the above-mentioned alkylene glycol compounds, calculated as 100 moles of the above-mentioned furan dicarboxylic acid compounds. When the contents of the above-mentioned furan dicarboxylic acid compounds and alkylene glycol compounds are within the above-mentioned range, the viscosity rise rate in the polycondensation reaction can be increased, and the color of the polymer can be improved.

[0101] On the other hand, considering the amount of substances lost or unreacted during the aforementioned esterification reaction, approximately 120% excess of alkylene glycol compounds can be used, based on furan dicarboxylic acid compounds. Therefore, when the molar ratio of the reactants is adjusted to the aforementioned range, a copolymer with the content of each residue controlled within the aforementioned range can be formed. More specifically, based on 100 moles of the aforementioned furan dicarboxylic acid compounds, the alkylene glycol compounds may be present in amounts of 100 moles or more, 110 moles or more, 115 moles or more, or 120 moles or more but less than 200 moles, 190 moles or less, 180 moles or less, or 150 moles or less.

[0102] The esterification reaction described above can be carried out in a nitrogen (N2) atmosphere, at a temperature range of 180 to 220°C, and at a pressure of 1 to 5.5 atm for 1 to 5 hours. For example, the esterification reaction can be carried out at temperatures above 180°C, above 182°C, above 184°C, or above 185°C and below 220°C, below 210°C, below 200°C, or below 195°C. Furthermore, the esterification reaction can be carried out at a pressure of 1 atm and below 5.5 atm, below 5 atm, below 3 atm, or below 1.5 atm, for 1 hour or more, 1.5 hours or more, or 2 hours or more and below 5 hours, below 4 hours, or below 3 hours. When the temperature, pressure, and reaction time of the esterification reaction are within the above ranges, the advantage is a high reaction yield and a complete reaction, thereby improving the physical properties of the final polyester and reducing the possibility of yellowing of the resulting polyester.

[0103] The esterification reaction described above can be carried out in a batch or continuous manner, and each raw material can be added individually. However, as an example, it can be added in the form of a slurry containing a furan dicarboxylic acid and the alkylene glycol described above.

[0104] The esterification reaction described above can also be carried out in the presence of esterification catalysts, including titanium (Ti) compounds, tin (Sn) compounds, and antimony (Sb) compounds. In particular, these esterification catalysts can improve the reaction rate from the initial stage of the reaction and shorten the time the polyester resin composition is exposed to heat. Depending on the central atom in the synthesized polyester, the concentration of the esterification catalyst can be from 1 ppm to 100 ppm. When the content of the esterification catalyst is within the above range, it has the advantage of improving the physical properties of the obtained polyester and significantly increasing the efficiency of the esterification reaction.

[0105] Next, the esterification product can be prepolymerized to obtain an oligomer with a higher degree of polymerization than the esterification product. More specifically, water is generated during the reaction of the furan dicarboxylic acid compound and the alkylene glycol compound. The esterification reaction ends when all the furan dicarboxylic acid compound dissolves and reaches the clear point.

[0106] The aforementioned prepolymerization can be carried out under temperature-controlled conditions (thermal pre-condensation). More specifically, the prepolymerization can include the following stages: heating up to a temperature range of 220 to 280°C or 220 to 260°C; and maintaining the above temperature to allow the esterification reaction product to prepolymerize. Additionally, the pressure can be reduced during the heating up until it reaches 0 to 1 atm or 0 to 0.5 atm, and then the pressure is maintained while maintaining the reached temperature. When the reached temperature, pressure, and reaction time during the prepolymerization process are within the aforementioned ranges, the advantage is that the reaction proceeds sufficiently, thereby improving the physical properties of the final polyester and reducing the likelihood of yellowing.

[0107] Following the prepolymerization described above, the prepolymer can undergo a polycondensation reaction. This polycondensation reaction can be carried out at a temperature of 220 to 280°C or 220 to 260°C and a pressure of less than 1 torr or 0.4 torr to 0.8 torr for 2 to 6 hours. When the temperature, pressure, and reaction time during the polycondensation are within the aforementioned ranges, the byproduct of the polycondensation reaction, namely the diol, can be effectively removed, thereby resulting in a final product exhibiting an appropriate intrinsic viscosity and reducing the likelihood of the obtained polyester yellowing.

[0108] In the above-mentioned polycondensation, a polycondensation catalyst can be used. This polycondensation catalyst can be added to the product of the esterification reaction before the start of the polycondensation reaction, or it can be added before the esterification reaction, or it can be added midway through the esterification reaction. As the above-mentioned polycondensation catalyst, titanium compounds, germanium compounds, antimony compounds, aluminum compounds, tin compounds, or mixtures thereof can be used. Examples of titanium compounds include tetraethyl titanate, acetyltripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, polybutyl titanate, 2-ethylhexyl titanate, octylene glycol titanate, lactate titanate, triethanolamine titanate, acetyl acetonate titanate, ethylacetoaceticester titanate, isostearyl titanate, titanium dioxide, titanium dioxide / silica copolymer, titanium dioxide / zirconium dioxide copolymer, etc. Examples of germanium compounds mentioned above include germanium dioxide (GeO2), germanium tetrachloride (GeCl4), germanium ethyleneglycoxide, germanium acetate, copolymers thereof, and mixtures thereof.

[0109] In the above composition, the content of the impurity 2-methyl-1,3-dioxolane generated by light or heat in the above polyester resin is adjusted to less than 10 ppm by weight.

[0110] In one implementation example, adjusting the content of the above-mentioned 2-methyl-1,3-dioxolane to below 10 ppm by weight can be achieved by performing the four heat treatment stages described later during the manufacturing process of the above-mentioned polyester resin, or by adding hydrazine additives.

[0111] In one implementation, the manufacturing of the polyester resin may include: after performing the aforementioned esterification reaction, prepolymerization and polycondensation reaction in the same manner, subjecting the product of the polycondensation reaction to an additional heat treatment of the four stages described later.

[0112] As an example, the above four stages of heat treatment may include a first heat treatment, a second heat treatment, a third heat treatment, and a fourth heat treatment performed at different temperatures. For instance, the second heat treatment may be performed at a higher temperature than the first heat treatment, the third heat treatment may be performed at a higher temperature than the second heat treatment, and the fourth heat treatment may be performed at a higher temperature than the third heat treatment. Under these conditions, the viscosity of the resin composition can be increased, and the content of impurities in the polyester resin generated by light or heat, namely the aforementioned 2-methyl-1,3-dioxolane, can be effectively reduced.

[0113] As an example, the heat treatment in all four stages described above can be performed within a temperature range of 50°C to 300°C. For instance, the first heat treatment can be performed at 40°C to 90°C, the second heat treatment at 100°C to 150°C, the third heat treatment at 160°C to 200°C, and the fourth heat treatment at 201°C to 250°C. Within this range, the formation of the aforementioned 2-methyl-1,3-dioxolane as an impurity can be effectively suppressed, thereby obtaining a polyester film with excellent optical properties and color performance.

[0114] As an example, the first heat treatment may include raising the temperature to 40°C to 90°C within 30 minutes to 1 hour and then holding it for 30 minutes to 1 hour; the second heat treatment may include raising the temperature to 100°C to 150°C within 30 minutes to 1 hour and then holding it for 30 minutes to 1 hour; the third heat treatment may include raising the temperature to 160°C to 200°C within 30 minutes to 2 hours and then holding it for 30 minutes to 1 hour; and the fourth heat treatment may include raising the temperature to 201°C to 250°C within 30 minutes to 2 hours and then holding it for 1 hour to 10 hours. Within this range, the formation of the aforementioned 2-methyl-1,3-dioxolane as an impurity can be effectively suppressed, thereby obtaining a polyester film with excellent optical properties and color performance.

[0115] On the other hand, another embodiment provides a polyester sheet comprising the aforementioned resin composition. Furthermore, yet another embodiment provides a polyester film comprising the aforementioned resin composition.

[0116] Implementation

[0117] The following describes embodiments and comparative examples of the present invention. These embodiments are merely examples of the present invention, and the present invention is not limited to these embodiments.

[0118] Example 1

[0119] In the hopper of a 10L autoclave reactor, 2,5-furandicarboxylic acid (FDCA, 5.48 mol, 856.9 g), a furandicarboxylic acid compound, and ethylene glycol (EG, 6.58 mol, 408.9 g), an alkylene glycol compound, were added at an equivalent ratio of 1:1.2.

[0120] Next, 10 ppm of a Ti-based chelating catalyst (AC436) as the esterification (ES) catalyst, based on metal content, and 10 ppm of aminoguanidine bicarbonate as an additive represented by the following chemical formula 5A, based on 1 kg of the complex, were added. The mixture was then stirred at 120 rpm and reacted for 3.5 hours at a pressure of 2.5 bar (approximately 2.467 atm), a temperature of 210°C, and a nitrogen atmosphere. After the 3.5-hour reaction, the pressure was reduced to atmospheric pressure, and the esterification reaction was terminated when more than 90% of the theoretical effluent water generated as a byproduct was discharged.

[0121] [Chemical Formula 5A]

[0122] Next, the internal temperature of the reactor is raised for 1 hour to reach a temperature range of 260°C. Then, the pressure is reduced in stages for 1 hour using a vacuum pump to bring the internal pressure of the reactor to a vacuum state below 0.8 torr, while prepolymerization is carried out.

[0123] Next, a polycondensation reaction was carried out at 260°C under a vacuum of less than 0.5 torr for 2 to 6 hours. When the load transferred to the torque meter of the autoclave reached the desired load, the product of the polycondensation reaction was dried immediately to obtain a polyester resin with a number average molecular weight (Mn) of 24,840 g / mol and a MWD of 1.89.

[0124] Example 2

[0125] A polyester resin with a number-average molecular weight (Mn) of 24,440 g / mol and a MWD of 1.92 was prepared by adding 100 ppm of the additive represented by the above chemical formula 5A, except by a method substantially the same as that in Example 1.

[0126] Example 3

[0127] The polyester resin with a number-average molecular weight (Mn) of 24,750 g / mol and a MWD of 1.82 was prepared by using an additive represented by chemical formula 5B instead of the additive represented by chemical formula 5A, otherwise the same method as in Example 1 was used.

[0128] [Chemical Formula 5B]

[0129] Example 4

[0130] The polyester resin with a number-average molecular weight (Mn) of 24,850 g / mol and a MWD of 1.8 was prepared by using 100 ppm of the additive represented by chemical formula 5B instead of the additive represented by chemical formula 5A, and otherwise by a method substantially the same as that in Example 1.

[0131] Example 5

[0132] The product of the above polycondensation reaction was placed in a vacuum oven, and the vacuum inside the oven was maintained at 0.5 Torr using a vacuum pump. After a first heat treatment (heating to 60°C for 30 minutes and holding for 1 hour), a second heat treatment (heating the product to 140°C for 1 hour and holding for 1 hour), a third heat treatment (heating the product to 200°C for 1 hour and holding for 1 hour), and a fourth heat treatment (heating the product to 210°C for 1 hour and holding for 6 hours), a polyester resin with a number average molecular weight (Mn) of 32,000 g / mol and a MWD of 1.85 was obtained at room temperature and pressure. Otherwise, the polyester resin was prepared by a method substantially the same as that described in Comparative Example 1 below.

[0133] Comparative Example 1

[0134] Aminoguanidine bicarbonate was not used as the additive represented by the above chemical formula 5A. Otherwise, a polyester resin with a number average molecular weight (Mn) of 24,800 g / mol and a MWD of 1.91 was prepared by substantially the same method as in Example 1.

[0135] Comparative Example 2

[0136] In the hopper of a first high-pressure reactor with a capacity of 10L, 2,5-furandicarboxylic acid (FDCA), a furandicarboxylic acid compound, and ethylene glycol (EG), an alkylene glycol compound, were added at an equivalent ratio of 1:1.3. Otherwise, a polyester resin with a number average molecular weight (Mn) of 24,340 g / mol and a MWD of 1.71 was prepared by substantially the same method as Comparative Example 1.

[0137] Comparative Example 3

[0138] In the hopper of a first high-pressure reactor with a capacity of 10L, 2,5-furandicarboxylic acid (FDCA), a furandicarboxylic acid compound, and ethylene glycol (EG), an alkylene glycol compound, were added at an equivalent ratio of 1:1.5. Otherwise, a polyester resin with a number average molecular weight (Mn) of 25,000 g / mol and a MWD of 1.82 was prepared by substantially the same method as Comparative Example 1.

[0139] Comparative Example 4

[0140] A polyester resin with a number-average molecular weight (Mn) of 24,860 g / mol and a MWD of 1.97 was prepared by adding 50 ppm of the above-mentioned Ti-based chelating catalyst (AC436) based on metal content, except by a method substantially the same as that used in Comparative Example 1.

[0141] Comparative Example 5

[0142] During the esterification reaction (ES), an additional 5 ppm of phosphoric acid (PA) as a heat stabilizer was added, and otherwise a polyester resin with a number average molecular weight (Mn) of 24,760 g / mol and a MWD of 1.95 was prepared by substantially the same method as Comparative Example 1.

[0143] Evaluation Example 1: Evaluation of the Physical Properties of Polyester Sheets

[0144] In Examples 1 to 5 and Comparative Examples 1 to 5, the valves at the bottom of the reactors for each polycondensation reaction were opened, and the resin composition containing the obtained polyester resin was extruded in filament form. After cooling in a water bath, the filamentous resin composition was placed between rollers using a pelletizer and cut by a cutter at the end to obtain polyester sheets with a certain width and thickness. The physical properties of the polyester sheets thus obtained were evaluated using the method described below, and are shown in Table 1.

[0145] Content evaluation of 2-methyl-1,3-dioxolane

[0146] Prepare 2-methyl-1,3-dioxolane (manufacturer: Sigma-Aldrich, product number: 292206). Dissolve 2-methyl-1,3-dioxolane in chloroform at concentrations of 1 ppm, 10 ppm, 50 ppm, and 100 ppm. Plot calibration curves for each concentration using GC-MS, at which point the reliability is adjusted to above 99.95%.

[0147] The 0.2 g of each polyester sheet manufactured in Examples 1 to 5 and Comparative Examples 1 to 5 was measured using the ASTM F 2013 method. 2-Methyl-1,3-dioxolane was measured at the same retention time as the calibration curve. The content of 2-methyl-1,3-dioxolane in the polyester sheet was measured based on the difference in area with each content calibration curve and is shown in Table 1.

[0148] Color difference meter evaluation

[0149] Fill more than half the capacity of the measuring container with polyester sheet, leaving the remainder empty. Then measure the L using a Nippon Denshoku (sa-4000) Chip colorimeter. and b The values ​​are shown in Table 1 below.

[0150] Inherent viscosity (Ⅳ) evaluation

[0151] 0.5 g of polyester sheet and 10 ml of solvent phenol:tetrachloroethane 1:1 (v:v) solution were completely dissolved in a 20 ml vial in an oil bath at 100 °C. The intrinsic viscosity (Ⅳ) was measured at 25 °C using an Ostwald viscometer and is shown in Table 1 below.

[0152] [Table 1]

[0153] Referring to Table 1 above, in the cases of Examples 1 to 5, the content of 2-methyl-1,3-dioxolane was less than 10 ppm. This confirms that, compared to Comparative Examples 1 to 5, with the decrease in L... The value increases, resulting in excellent transmittance, and with the increase of b The lower the value, the less heat discoloration, and the better the color of the polyester chip.

[0154] Evaluation Example 2: Evaluation of the Physical Properties of Polyester Film

[0155] In Evaluation Example 1, polyester films were manufactured using the polyester sheets produced in Examples 1 to 5 and Comparative Examples 1 to 5. Specifically, each polyester sheet was melted in an extruder at 180°C to 260°C, and then the melt was extruded through a die to form a sheet, which was then rapidly cooled. The resulting sheet was stretched 3.0 times in the longitudinal direction (MD) and 3.7 times in the transverse direction (TD), and to impart dimensional stability, the stretched film was heat-fixed under tension at 120°C to 160°C, thereby obtaining a biaxially stretched polyester film.

[0156] Y transmittance (D65) evaluation

[0157] The polyester films manufactured in Examples 1 to 5 and Comparative Examples 1 to 5 were cut into 10 cm × 10 cm (longitudinal length × transverse length) pieces to prepare samples. The parallel transmittance and diffuse transmittance of these samples were measured using a Minolta CM-3600A measuring instrument according to the ASTM D1003-97 method. The transmittance was defined as the sum of the parallel transmittance and diffuse transmittance. The transmittance values ​​are shown in Table 2 below.

[0158] Yellowness (Yellow Index) and b Value Evaluation

[0159] The polyester films manufactured in Examples 1 to 5 and Comparative Examples 1 to 5 were cut into 10 cm × 10 cm (longitudinal length × transverse length) pieces to prepare samples. The yellowness (yellow index) and b of these samples were measured according to ASTM E313 method. The values ​​are shown in Table 2 below.

[0160] Haze rating

[0161] For the polyester films manufactured in Examples 1 to 5 and Comparative Examples 1 to 5, the haze of the films was measured using a Murakami ColorResearch Lab. (hm-150) device, i.e., a haze meter, and the results are shown in Table 2 below.

[0162] [Table 2]

[0163] Referring to Table 2 above, it can be confirmed that in the cases of Examples 1 to 5, compared with Comparative Examples 1 to 5, the transmittance (D65) is higher and the transmittance is excellent, but the yellowness and b are lower. It has a low value, less thermal discoloration, and low haze, thus exhibiting excellent optical properties.

[0164] The preferred embodiments have been described in detail above, but the scope of the present invention is not limited thereto. Various modifications and improvements made by those skilled in the art using the basic concepts defined in the following claims also fall within the scope of the present invention.

Claims

1. A resin composition comprising a polyester resin containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols, and The content of 2-methyl-1,3-dioxolane as an impurity is less than 10 ppm by weight.

2. A resin composition, wherein, According to CIE 1976 L a b b in color system Values ​​range from 7.0 to 15.

0.

3. The resin composition of claim 1, wherein, According to CIE 1976 L a b L in color scheme The value ranges from 58.0 to 75.

5.

4. The resin composition of claim 1, further comprising hydrazine additives.

5. The resin composition of claim 1, further comprising an additive represented by chemical formula 1A, an additive represented by chemical formula 1B, or a combination thereof. [Chemical Formula 1A] [Chemical Formula 1B] In the above chemical formula 1A, R1 to R4 are each independently hydrogen, or substituted or unsubstituted C1 to C5 alkyl groups, and X is carbonic acid, hydrochloric acid, sulfuric acid, nitric acid, or a combination thereof. In the above chemical formula 1B, X1 to X4 are each independently S, O, NR5, R5 is hydrogen, or a substituted or unsubstituted C1 to C5 alkyl group, Y1 - and Y2 - Each independently is -SO3 - -Cl - Or a combination of them, Z + NH4 + .

6. The resin composition of claim 1, further comprising an additive represented by chemical formula 2A, an additive represented by chemical formula 2B, or a combination thereof. [Chemical Formula 2A] [Chemical Formula 2B] In the above chemical formula 2A, R1 to R4 are each independently hydrogen, or substituted or unsubstituted C1 to C5 alkyl groups, and X is carbonic acid, hydrochloric acid, sulfuric acid, nitric acid, or a combination thereof. In the above chemical formula 2B, R5 and R6 are each independently hydrogen, or substituted or unsubstituted C1 to C5 alkyl groups, Z + NH4 + .

7. The resin composition of claim 1, further comprising an additive represented by chemical formula 3A, an additive represented by chemical formula 3B, or a combination thereof. [Chemical Formula 3A] [Chemical Formula 3B] In the above chemical formula 3A, R1 to R4 are each independently hydrogen, or substituted or unsubstituted C1 to C5 alkyl groups. In the above chemical formula 3B, R5 and R6 are each independently hydrogen, or substituted or unsubstituted C1 to C5 alkyl groups.

8. The resin composition of claim 1, further comprising an additive represented by chemical formula 4A, an additive represented by chemical formula 4B, or a combination thereof. [Chemical Formula 4A] [Chemical Formula 4B] 。 9. The resin composition of claim 1, wherein, The content of the above-mentioned 2-methyl-1,3-dioxolane is less than 5 ppm by weight.

10. The resin composition of claim 1, wherein, The content of the above-mentioned 2-methyl-1,3-dioxolane is less than 2 ppm by weight.

11. A method for manufacturing a resin composition, comprising: Prepare a composition comprising a polyester resin containing residues derived from furan dicarboxylic acids and residues derived from alkylene glycols. In the above composition, the content of the impurity 2-methyl-1,3-dioxolane generated by light or heat in the above polyester resin is adjusted to less than 10 ppm by weight.

12. The method for manufacturing the resin composition according to claim 11, wherein, Adjusting the content of 2-methyl-1,3-dioxolane to below 10 ppm by weight involves either heat treatment in four stages during the manufacturing process of the aforementioned polyester resin, or the addition of hydrazine additives.

13. The method for manufacturing the resin composition according to claim 12, wherein, The four stages of heat treatment mentioned above include a first heat treatment, a second heat treatment, a third heat treatment, and a fourth heat treatment performed at different temperatures. The first heat treatment described above is carried out at a temperature between 40°C and 90°C. The second heat treatment described above is carried out at 100°C to 150°C. The third heat treatment mentioned above is carried out at 160°C to 200°C. The aforementioned fourth heat treatment was carried out at 201°C to 250°C.

14. A polyester sheet comprising the resin composition of claim 1.

15. A polyester film comprising the resin composition of claim 1.

Images