Coating composition comprising copolymer and method for preparing same

Abstract

A coating composition according to an embodiment of the present disclosure may contain a copolymer, wherein the copolymer may comprise a polymer resin including bis-2-hydroxyethyl terephthalate and an unsaturated polybasic acid bonded to the bis-2-hydroxyethyl terephthalate, and an acrylic resin polymerized to the unsaturated polybasic acid via an unsaturated bond of the unsaturated polybasic acid.

Description

Paint composition containing copolymer and method for producing same

[0001] The embodiments disclosed in this document relate to a paint composition and a method for producing the same, for example, to a paint composition comprising a copolymer.

[0002] While conventional PET resin-based paints can achieve the same level of appearance quality as petroleum-based paints, the fewer reactive groups involved in polymer reactions when mixed with other resins (e.g., acrylic resins) and solvents, the paint's adhesiveness deteriorates, leading to problems such as film peeling, reduced chemical resistance, and poor stain resistance. Therefore, extensive research is being conducted to improve the physical properties of paints (e.g., compatibility and durability).

[0003] According to one embodiment of the present disclosure, a paint composition may include a copolymer, wherein the copolymer may include a polymer resin comprising an unsaturated polybasic acid bonded to bis-2-hydroxyethyl terephthalate and the BHET, and an acrylic resin polymerized to the unsaturated polybasic acid through an unsaturated bond of the unsaturated polybasic acid.

[0004] According to one embodiment of the present disclosure, a coating applied to a surface of an object includes a primer layer, a color coating layer, a top coating layer, and a copolymer, wherein the copolymer may be included in at least one of the primer layer, the color coating layer, and the top coating layer, and wherein the copolymer may include a polymer resin including bis-2-hydroxyethyl terephthalate (BHET) and an unsaturated polybasic acid bonded to the BHET, and an acrylic resin polymerized to the unsaturated polybasic acid through an unsaturated bond of the unsaturated polybasic acid.

[0005] FIG. 1 is a flowchart of a method for manufacturing a paint composition according to one embodiment of the present disclosure.

[0006] FIG. 2 is a flowchart of a method for manufacturing a paint composition according to one embodiment of the present disclosure.

[0007] FIG. 3 illustrates infrared spectral results for a coating film containing a copolymer according to one embodiment of the present disclosure.

[0008] FIG. 4 illustrates a coating film formed on a surface of an object (e.g., an electronic device) including a coating composition according to one embodiment of the present disclosure.

[0009] The following description of the accompanying drawings may provide an understanding of various exemplary implementations of the present disclosure, including the claims and their equivalents. While the exemplary embodiments disclosed in the following description include numerous specific details to aid understanding, they are to be considered as one example of various exemplary embodiments. Accordingly, those skilled in the art will appreciate that various modifications and variations of the various implementations described herein may be made without departing from the scope and spirit of the disclosure. Furthermore, descriptions of well-known functions and configurations may be omitted for clarity and conciseness.

[0010] The terms and words used in the following description and claims are not limited to their reference meanings and can be used to clearly and consistently describe one embodiment of the present disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various implementations of the disclosure is provided for illustrative purposes, not for the purpose of limiting the scope of the disclosure and its equivalents.

[0011] Unless the context clearly dictates otherwise, the singular forms of "a," "an," and "the" should be understood to include plural meanings. Thus, for example, "a component surface" could be understood to include one or more of the surfaces of the component.

[0012] The various embodiments and terminology used in this document are not intended to limit the technical features described in this document to specific embodiments, but should be understood to encompass various modifications, equivalents, or alternatives of the embodiments. In connection with the description of the drawings, similar reference numerals may be used to refer to similar or related components. The singular form of a noun corresponding to an item may include one or more of the items, unless the context clearly indicates otherwise.

[0013] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0014] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another, and do not qualify the components in any other respect (e.g., importance or order).

[0015] FIG. 1 is a flowchart of a method for manufacturing a paint composition according to one embodiment of the present disclosure.

[0016] Referring to FIG. 1, a method for manufacturing a paint composition according to one embodiment of the present disclosure may include a depolymerization step (S1), a mixing step of an unsaturated polybasic acid (S2), and a mixing step of an acrylic resin (S3). Hereinafter, each step of the method for manufacturing the paint composition will be described in detail with reference to chemical formulas and reaction formulas.

[0017] According to one embodiment of the present disclosure, a coating composition may contain a copolymer comprising a plurality of polymers. The copolymer may include a polymer resin comprising bis-2-hydroxyethyl terephthalate (BHET) and an unsaturated polybasic acid bonded to the BHET. The copolymer may include an acrylic resin polymerized to the unsaturated polybasic acid via an unsaturated bond of the unsaturated polybasic acid.

[0018] The unsaturated polybasic acid described in this document may be understood as an acid having an unsaturated bond (e.g., a double bond or a triple bond) and multiple acidic hydrogens. For example, the unsaturated polybasic acid may include fumaric acid, tetrahydrophthalic anhydride, maleic acid, maleic anhydride, etc.

[0019] According to one embodiment of the present disclosure, the bis-2-hydroxyethyl terephthalate (BHET) included in the copolymer can be obtained through a depolymerization step (S1). As a method for obtaining bis-2-hydroxyethyl terephthalate (BHET), the depolymerization is only one example, and the bis-2-hydroxyethyl terephthalate can also be obtained by other methods.

[0020] According to one embodiment of the present disclosure, referring to the following [Reaction Scheme 1], it can be confirmed that in the depolymerization step (S1), the bis-2-hydroxyethyl terephthalate (BHET) is obtained. As an example, the bis-2-hydroxyethyl terephthalate (BHET) can be obtained through a glycolysis depolymerization method using ethylene glycol (Ethylene Glycol) from waste PET plastic.

[0021] [Reaction Formula 1]

[0022]

[0023] According to one embodiment of the present disclosure, in the step (S2) of mixing an unsaturated polybasic acid, the unsaturated polybasic acid and the obtained bis-2-hydroxyethyl terephthalate may be mixed. In the step (S2) of mixing an unsaturated polybasic acid, the unsaturated polybasic acid and the obtained bis-2-hydroxyethyl terephthalate may be combined with each other.

[0024] According to one embodiment of the present disclosure, the unsaturated polybasic acid may include an unsaturated bond (e.g., a double bond or a triple bond). The unsaturated polybasic acid may polymerize with another resin (e.g., an acrylic resin or an acrylic polyol) included in the paint through the unsaturated bond to form the copolymer.

[0025] Therefore, according to one embodiment of the present disclosure, the polymer resin including the unsaturated polybasic acid may have high miscibility with the other resin (e.g., acrylic resin). As an example, the unsaturated polybasic acid may be tetrahydrophthalic anhydride represented by the following [chemical formula 1]. As another example, the unsaturated polybasic acid may be fumaric acid represented by the following [chemical formula 2].

[0026] [Chemical Formula 1]

[0027]

[0028] [Chemical Formula 2]

[0029]

[0030] According to one embodiment of the present disclosure, the polymer resin may include the bis-2-hydroxyethyl terephthalate (BHET) and the unsaturated polybasic acid bonded to the bis-2-hydroxyethyl terephthalate. As an example, the bis-2-hydroxyethyl terephthalate and the unsaturated polybasic acid may be bonded to each other through an ester condensation reaction.

[0031] As an example, the following [Reaction Formula 2] shows a reaction in which the unsaturated polybasic acid is tetrahydrophthalic anhydride, and the tetrahydrophthalic anhydride and the bis-2-hydroxyethyl terephthalate combine through an ester condensation reaction to form the polymer resin.

[0032] [Reaction Formula 2]

[0033]

[0034] As another example, the following [Reaction Formula 3] shows a reaction in which the unsaturated polybasic acid is fumaric acid, and the fumaric acid and the bis-2-hydroxyethyl terephthalate combine through an ester condensation reaction to form the polymer resin.

[0035] [Reaction Formula 3]

[0036]

[0037] According to one embodiment of the present disclosure, the weight ratio of the bis-2-hydroxyethyl terephthalate may be 35 wt% to 60 wt% with respect to the total weight of the copolymer. If the weight ratio of the bis-2-hydroxyethyl terephthalate is less than 35 wt% with respect to the total weight of the copolymer, the adhesion and acid resistance of the coating film of the coating composition according to one embodiment of the present disclosure may be deteriorated, and if the weight ratio of the bis-2-hydroxyethyl terephthalate exceeds 60 wt%, the alkali resistance and thermal properties of the coating film of the coating composition according to one embodiment of the present disclosure may be deteriorated. Therefore, with respect to 100 wt% of the total weight of the copolymer, the weight ratio of the bis-2-hydroxyethyl terephthalate is preferably 35 wt% to 60 wt%.

[0038] According to one embodiment of the present disclosure, in the mixing step (S3) of the acrylic resin, the polymer resin formed by combining the unsaturated polybasic acid and the bis-2-hydroxyethyl terephthalate and the acrylic resin may be mixed. As an example, the copolymer may be obtained by mixing and reacting 35 wt% to 70 wt% of the polymer resin and 5 wt% to 15 wt% of the acrylic resin. In the mixing step (S3) of the acrylic resin, the polymer resin and the acrylic resin may be polymerized with each other.

[0039] According to one embodiment of the present disclosure, due to the unsaturated bond of the derivative portion of the unsaturated polybasic acid included in the polymer resin, the miscibility of the polymer resin and the acrylic resin can be improved. As an example, the polymer resin and the acrylic resin can be polymerized with each other through a radical reaction via the unsaturated bond. The copolymer can have a weight average molecular weight of 70,000 to 120,000. The glass transition temperature of the copolymer can be 50 to 110 degrees Celsius.

[0040] According to one embodiment of the present disclosure, the acrylic resin may be understood as a polymer comprising an acrylic monomer. As an example, the acrylic monomer may comprise methyl methacrylate.

[0041] According to one embodiment of the present disclosure, the weight ratio of the acrylic resin may be 20 wt% to 50 wt% with respect to the total weight of the copolymer. If the weight ratio of the acrylic resin with respect to 100 wt% of the total weight of the copolymer is less than 20 wt%, the alkali resistance and thermal properties of the coating film of the paint composition according to one embodiment of the present disclosure may deteriorate, and if the weight ratio of the acrylic resin exceeds 50 wt%, the adhesion and impact resistance of the coating film of the paint composition according to one embodiment of the present disclosure may deteriorate. Therefore, the weight ratio of the acrylic resin with respect to 100 wt% of the total weight of the copolymer is preferably 20 wt% to 50 wt%.

[0042] As an example, the following [Chemical Formula 3] represents a copolymer according to one embodiment of the present disclosure, wherein the polymer resin and the acrylic resin are polymerized with each other through an unsaturated bond of the unsaturated polybasic acid (e.g., tetrahydrophthalic anhydride).

[0043] [Chemical Formula 3]

[0044]

[0045] As another example, the following [Chemical Formula 4] represents a copolymer according to one embodiment of the present disclosure, wherein the polymer resin and the acrylic resin are polymerized with each other through an unsaturated bond of the unsaturated polybasic acid (e.g., fumaric acid).

[0046] [Chemical Formula 4]

[0047]

[0048] FIG. 2 is a flowchart of a method for manufacturing a paint composition according to one embodiment of the present disclosure.

[0049] Referring to FIG. 2, the method for manufacturing the paint composition according to one embodiment of the present disclosure may further include a step of mixing a silicone additive (S4) performed after the step of mixing an acrylic resin (S3). Hereinafter, the step of mixing a silicone additive (S4) of the method for manufacturing the paint composition will be described in detail with reference to chemical formulas and reaction formulas.

[0050] According to one embodiment of the present disclosure, in the mixing step (S4) of the silicone additive, the copolymer and the silicone additive according to one embodiment of the present disclosure may be mixed. As an example, the monomer of the silicone additive may be a modified silicone additive represented by the following [Chemical Formula 5]. As an example, the silicone additive may include a silicone phthalate additive. As another example, the silicone additive may include a polyester-modified polydimethyl siloxane, a polyether-modified polydimethyl siloxane, or a polymer thereof.

[0051] [Chemical Formula 5]

[0052]

[0053] According to one embodiment of the present disclosure, in the silicone additive mixing step (S4), by polymerizing the silicone additive into the copolymer according to one embodiment of the present disclosure, the durability (e.g., chemical resistance, adhesion, contamination resistance, and / or heat resistance, etc.) of the coating film of the paint composition according to one embodiment of the present disclosure can be improved.

[0054] According to one embodiment of the present disclosure, the silicone additive may be bonded (or polymerized) to the derivative portion of the acrylic resin of the copolymer or the derivative portion of the bis-2-hydroxyethyl terephthalate. As an example, the following [Chemical Formula 6] shows a copolymer in which tetrahydrophthalic anhydride is used as the unsaturated polybasic acid, and the silicone additive is polymerized to the derivative portion of the bis-2-hydroxyethyl terephthalate of the copolymer.

[0055] [Chemical Formula 6]

[0056]

[0057] As another example, the following [Chemical Formula 7] shows a copolymer according to one embodiment of the present disclosure, wherein tetrahydrophthalic anhydride is used as the unsaturated polybasic acid, and the silicone additive is polymerized into the derivative portion of the acrylic resin of the copolymer.

[0058] [Chemical Formula 7]

[0059]

[0060] As another example, the following [Chemical Formula 8] shows a copolymer in which fumaric acid is used as the unsaturated polybasic acid and the silicone additive is polymerized on the derivative portion of the bis-2-hydroxyethyl terephthalate of the copolymer.

[0061] [Chemical Formula 8]

[0062]

[0063] As another example, the following [Chemical Formula 9] shows a copolymer according to one embodiment of the present disclosure, wherein fumaric acid is used as the unsaturated polybasic acid, and the silicone additive is polymerized into the derivative portion of the acrylic resin of the copolymer.

[0064] [Chemical Formula 9]

[0065]

[0066] Meanwhile, FIG. 3 illustrates an infrared spectral result (graph) for a coating film containing a copolymer according to an embodiment of the present disclosure. The infrared spectral result illustrated in FIG. 3 can be understood as a result obtained by performing FT-IR (Fourier Transform Infrared Spectroscopy) analysis on a coating film (e.g., top coat) containing the copolymer according to an embodiment of the present disclosure.

[0067] Referring to FIG. 3, it can be confirmed that the coating film containing the copolymer according to one embodiment of the present disclosure has an ester group (R-COO-R') peak value in the wavenumber range of about 1245 to 1274. Therefore, since the coating composition containing the copolymer according to one embodiment of the present disclosure has a peak value in the wavenumber range corresponding to the ester group (R-COO-R') in the FT-IR analysis result, it can be understood that the coating includes the coating composition according to one embodiment of the present disclosure.

[0068] FIG. 4 illustrates a coating film including a coating composition according to one embodiment of the present disclosure formed on a surface of an object (e.g., an outer cover (380) of an electronic device (101)).

[0069] FIG. 4 illustrates an electronic device (101) including, by way of example, a frame structure (310), a display (330), a printed circuit board (360), a battery (350), a camera (207), and / or an outer cover (380).

[0070] Referring to FIG. 4, according to one embodiment of the present disclosure, the paint composition may be applied in the form of a paint film (200) on an outer surface (e.g., an outer cover (380)) of an article (e.g., an electronic device (101)). As an example, the paint film (200) may be understood as a film coated on the outer cover (380) of the electronic device (101). As another example, according to one embodiment of the present disclosure, the paint film (200) including the paint composition may be coated on a frame structure (310) of the electronic device (101).

[0071] According to one embodiment of the present disclosure, the coating film (200) may include a plurality of layers. For example, the coating film (200) may include a primer layer (210) (or a lower layer), a color coating layer (220) (or an intermediate layer), and / or a top coating layer (230) (or a top layer). The primer layer (210), the color coating layer (220), and the top coating layer (230) are layers of a general coating film, and can be understood based on their names and general technical common sense of a person skilled in the art. As an example, the primer layer (210) may be understood as a first layer applied to improve adhesion between a substrate (e.g., an outer cover (380)) and an upper coating layer (e.g., a color coating layer (220)), the color coating layer (220) may be understood as a second layer applied to provide an appearance (color), and the top coating layer (230) may be understood as a final protective layer applied to protect the lower coating layers (e.g., the primer layer (210) and the color coating layer (220)) from the external environment.

[0072] According to one embodiment of the present disclosure, a paint composition including the copolymer may be applied to at least one of a primer layer (210), a color coating layer (220), and a top coating layer (230) of a coating film (200). Hereinafter, the compositions of the primer layer (210), the color coating layer (220), and the top coating layer (230) according to one embodiment of the present disclosure will be described.

[0073] According to one embodiment of the present disclosure, the primer layer (210) of the coating film (200) may include a paint composition containing the copolymer described above. The primer layer (210) may include 30 wt% to 60 wt% of the copolymer, 5 wt% to 30 wt% of an acrylic resin containing biomass, 1 wt% to 5 wt% of cellulose acetate butyrate, 1 wt% to 3 wt% of a pigment, and / or 30 wt% to 50 wt% of a mixed solvent. The copolymer included in the primer layer (210) may include the polymer resin, the acrylic resin, and / or the silicone additive.

[0074] According to one embodiment of the present disclosure, the color coating layer (220) of the coating film (200) may include a paint composition containing the copolymer described above. The color coating layer (220) of the coating film (200) may include 20 wt% to 50 wt% of the copolymer, 5 wt% to 15 wt% of an acrylic resin containing biomass, 1 wt% to 5 wt% of cellulose acetate butalate, 0.1 wt% to 1 wt% of a silicone additive, 1 wt% to 3 wt% of a pigment, and / or 25 wt% to 45 wt% of a mixed solvent.

[0075] According to one embodiment of the present disclosure, the copolymer included in the primer layer (210) and / or the color coating layer (220) can be obtained by mixing and reacting 35 wt% to 70 wt% of the polymer resin and 5 wt% to 15 wt% of the acrylic resin. The weight average molecular weight of the copolymer included in the primer layer (210) and / or the color coating layer (220) can be 10,000 to 150,000 g / mol. The glass transition temperature of the copolymer included in the primer layer (210) and / or the color coating layer (220) can be 50 degrees Celsius to 110 degrees Celsius. If the glass transition temperature of the above copolymer is lower than 50 degrees Celsius, the heat resistance of the coating film (200) may be reduced, and if it is higher than 110 degrees Celsius, the coating film (200) may be easily broken or the durability may be reduced.

[0076] According to one embodiment of the present disclosure, the cellulose acetate butalate may have a weight average molecular weight (Mw) of 20,000 to 40,000 g / mol. The cellulose acetate butalate may have a hydroxyl group content of 0.1 to 0.3 wt%. The glass transition temperature (Tg) may be 50 to 100°C. The cellulose acetate butalate may have a glass transition temperature of 50 to 100°C.

[0077] According to one embodiment of the present disclosure, the mixed solvent may be an ester, a ketone, an aromatic, or a mixture thereof.

[0078] According to one embodiment of the present disclosure, a method for painting a primer layer (210) and / or a color coating layer (220) may include adding a curing agent at a ratio of 5 wt% to 20 wt% based on a total of 100 wt% of the paint composition as a mixing ratio of the paint and the curing agent, adjusting the viscosity of the paint to about 10.0 to 15.0 Ford Cup No. 4 (sec) using a diluting solvent, and performing the painting by spraying, and thereafter, pretreating a PC or PC-ABS material with IPA or the like, applying the diluted paint at a thickness of 5 μm to 15 μm, and then drying at 60 degrees Celsius for 10 minutes.

[0079] According to one embodiment of the present disclosure, the top coating layer (230) of the coating film (200) may include a UV topcoat layer coated on the color coating layer and including a photoinitiator, and an acrylic urethane topcoat layer coated on the UV topcoat layer. The acrylic urethane topcoat layer may include 30 wt% to 50 wt% of the copolymer, 10 wt% to 20 wt% of an acrylic urethane resin containing biomass, 1 wt% to 3 wt% of a silicone additive, and 30 wt% to 50 wt% of a mixed solvent. The copolymer included in the acrylic urethane topcoat layer may have a hydroxyl value of 70 to 150 mgKOH / g and include hydroxyl groups having a weight average molecular weight of 5,000 to 10,000.

[0080] While conventional PET resin-based paints can achieve the same level of appearance quality as petroleum-based paints, the fewer reactive groups involved in polymer reactions when mixed with other resins (e.g., acrylic resins) and solvents, the paint's adhesiveness deteriorates, leading to problems such as film peeling, reduced chemical resistance, and poor stain resistance. Therefore, extensive research is being conducted to improve the physical properties of paints (e.g., compatibility and durability).

[0081] The problem to be solved in the present disclosure may be to improve the miscibility between resins contained in paint.

[0082] The problem to be solved in the present disclosure may be improving the durability of paint.

[0083] However, the problem to be solved in this disclosure is not limited to the problem mentioned above, and may be determined in various ways without departing from the spirit and scope of this disclosure.

[0084] The paint composition according to various embodiments of the present disclosure can improve miscibility with other resins by adding a monomer having an unsaturated bond.

[0085] The paint composition according to various embodiments of the present disclosure can improve the durability of the paint by adding a modified silicone component to a copolymer included in the paint.

[0086] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the above description.

[0087] According to one embodiment of the present disclosure, the paint composition may include (or contain) a copolymer.

[0088] According to one embodiment of the present disclosure, the copolymer may include a polymer resin comprising bis-2-hydroxyethyl terephthalate (BHET) and an unsaturated polybasic acid bonded to the BHET.

[0089] According to one embodiment of the present disclosure, the copolymer may include an acrylic resin polymerized to the unsaturated polybasic acid through an unsaturated bond of the unsaturated polybasic acid.

[0090] According to one embodiment of the present disclosure, the copolymer may comprise 35 wt% to 60 wt% of the bis-2-hydroxyethyl terephthalate, based on the total weight of the copolymer.

[0091] According to one embodiment of the present disclosure, the copolymer may have a weight average molecular weight of 70,000 to 120,000.

[0092] According to one embodiment of the present disclosure, the glass transition temperature of the copolymer may be from 50 degrees Celsius to 110 degrees Celsius.

[0093] According to one embodiment of the present disclosure, the bis-2-hydroxyethyl terephthalate can be obtained through depolymerization.

[0094] According to one embodiment of the present disclosure, polymerization of the acrylic resin and the unsaturated polybasic acid may proceed after the combination of the unsaturated polybasic acid and the bis-2-hydroxyethyl terephthalate.

[0095] According to one embodiment of the present disclosure, the copolymer may include 20 wt% to 50 wt% of the acrylic resin based on the total weight of the copolymer.

[0096] According to one embodiment of the present disclosure, the unsaturated polybasic acid can be combined with the bis-2-hydroxyethyl terephthalate through an ester condensation reaction.

[0097] According to one embodiment of the present disclosure, the acrylic resin can be polymerized with the unsaturated polybasic acid through a radical reaction.

[0098] According to one embodiment of the present disclosure, the copolymer may include a silicone additive polymerized with the bis-2-hydroxyethyl terephthalate or the acrylic resin.

[0099] According to one embodiment of the present disclosure, the silicone additive may be a polyester-modified polydimethyl siloxane, a polyether-modified polydimethyl siloxane, or a polymer thereof.

[0100] According to one embodiment of the present disclosure, the paint composition may be included in at least one of a primer layer (210), a color coating layer (220), or a top coating layer (230) of a coating film (200).

[0101] A paint comprising a paint composition according to one embodiment of the present disclosure can be applied to a surface of an object (380) to form a coating film (200).

[0102] According to one embodiment of the present disclosure, the coating (200) may include a primer layer (210), a color coating layer (220), and / or a top coating layer (230).

[0103] According to one embodiment of the present disclosure, at least one of the primer layer (210), the color coating layer (220), and the top coating layer (230) may include a copolymer according to one embodiment of the present disclosure.

[0104] According to one embodiment of the present disclosure, the primer layer (210) may include 30 wt% to 60 wt% of the copolymer.

[0105] According to one embodiment of the present disclosure, the primer layer (210) may include 5 wt% to 30 wt% of an acrylic resin containing biomass.

[0106] According to one embodiment of the present disclosure, the primer layer (210) may include 1 wt% to 5 wt% of cellulose acetate butyrate.

[0107] According to one embodiment of the present disclosure, the primer layer (210) may include 1 wt% to 3 wt% of a pigment and 30 wt% to 50 wt% of a mixed solvent.

[0108] According to one embodiment of the present disclosure, the copolymer may include a silicone additive polymerized with the bis-2-hydroxyethyl terephthalate or the acrylic resin.

[0109] According to one embodiment of the present disclosure, the color coating layer (220) may include 20 wt% to 50 wt% of the copolymer.

[0110] According to one embodiment of the present disclosure, the color coating layer (220) may include 5 wt% to 15 wt% of an acrylic resin containing biomass.

[0111] According to one embodiment of the present disclosure, the color coating layer (220) may include 1 wt% to 5 wt% of cellulose acetate butyrate.

[0112] According to one embodiment of the present disclosure, the color coating layer (220) may include 0.1 wt% to 1 wt% of a silicone additive.

[0113] According to one embodiment of the present disclosure, the color coating layer (220) may include 1 wt% to 3 wt% of pigment.

[0114] According to one embodiment of the present disclosure, the color coating layer (220) may include 25 wt% to 45 wt% of a mixed solvent.

[0115] According to one embodiment of the present disclosure, the top coating layer (230) may include a UV topcoat layer coated on the color coating layer and including a photoinitiator, and an acrylic urethane topcoat layer coated on the UV topcoat layer.

[0116] According to one embodiment of the present disclosure, the acrylic urethane topcoat layer may include 30 wt% to 50 wt% of the copolymer.

[0117] According to one embodiment of the present disclosure, the acrylic urethane topcoat layer may include 10 wt% to 20 wt% of an acrylic urethane resin containing biomass.

[0118] According to one embodiment of the present disclosure, the acrylic urethane topcoat layer may include 1 wt% to 3 wt% of a silicone additive.

[0119] According to one embodiment of the present disclosure, the acrylic urethane topcoat layer may include 30 wt% to 50 wt% of a mixed solvent.

[0120] According to one embodiment of the present disclosure, the copolymer may include hydroxyl groups having a hydroxyl value of 70 to 150 mgKOH / g and a weight average molecular weight of 5,000 to 10,000.

[0121] A copolymer according to one embodiment of the present disclosure may include a polymer resin comprising bis-2-hydroxyethyl terephthalate (BHET) and an unsaturated polybasic acid bonded to the BHET, and an acrylic resin polymerized to the unsaturated polybasic acid through an unsaturated bond of the unsaturated polybasic acid.

[0122] Although the detailed description of this document has described specific embodiments, it will be apparent to those skilled in the art that various modifications are possible without departing from the scope of this document.

Claims

1. In a paint composition containing a copolymer, The above copolymer: A polymer resin comprising bis-2-hydroxyethyl terephthalate (BHET) and an unsaturated polybasic acid bonded to the BHET; and A paint composition comprising an acrylic resin polymerized to an unsaturated polybasic acid through an unsaturated bond of the unsaturated polybasic acid.

2. In paragraph 1, A paint composition comprising 35 wt% to 60 wt% of the bis-2-hydroxyethyl terephthalate based on the total weight of the copolymer.

3. In paragraph 1 or 2, The above copolymer is, A paint composition having a weight average molecular weight of 70,000 to 120,000.

4. In any one of paragraphs 1 to 3, A paint composition wherein the glass transition temperature of the above copolymer is 50 to 110 degrees Celsius.

5. In any one of paragraphs 1 to 4, The above bis-2-hydroxyethyl terephthalate is a paint composition obtained through depolymerization.

6. In any one of paragraphs 1 to 5, A paint composition in which polymerization of the acrylic resin and the unsaturated polybasic acid is performed after the combination of the unsaturated polybasic acid and the bis-2-hydroxyethyl terephthalate.

7. In any one of paragraphs 1 to 6, A paint composition comprising 20 wt% to 50 wt% of the acrylic resin based on the total weight of the copolymer.

8. In any one of paragraphs 1 to 7, The above unsaturated polybasic acid is, A paint composition combined with the above bis-2-hydroxyethyl terephthalate through an ester condensation reaction.

9. In any one of paragraphs 1 to 8, The above acrylic resin is, A paint composition that polymerizes with the unsaturated polybasic acid through a radical reaction.

10. In any one of paragraphs 1 to 9, The above copolymer: A paint composition comprising a silicone additive polymerized with the above bis-2-hydroxyethyl terephthalate or the above acrylic resin.

11. In paragraph 10, The above silicone additive is, A paint composition comprising polyester-modified polydimethyl siloxane, polyether-modified polydimethyl siloxane, or a polymer thereof.

12. In any one of paragraphs 1 to 11, The above paint composition, A paint composition included in at least one of a primer layer (210), a color coating layer (220), or a top coating layer (230) of a coating film (200).

13. In any one of paragraphs 1 to 11, The above polymer resin is obtained by polymerizing the above bis-2-hydroxyethyl terephthalate (BHET) and the above unsaturated polybasic acid, The above copolymer is a paint composition obtained by polymerizing the above polymer resin and the above acrylic resin through an unsaturated bond of the above unsaturated polybasic acid.

14. In the paint manufacturing method, A step (S2) of mixing bis-2-hydroxyethyl terephthalate (BHET) and an unsaturated polybasic acid having an unsaturated bond to obtain an intermediate in which the BHET and the unsaturated polybasic acid are polymerized; and A method for manufacturing a paint, comprising a step (S3) of mixing a sizing intermediate and an acrylic resin to obtain a copolymer in which the intermediate and the acrylic resin are polymerized through the unsaturated bond.

15. In paragraph 14, A paint manufacturing method further comprising a step (S4) of mixing the copolymer and the silicone additive and polymerizing the copolymer and the silicone additive.

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