Biodegradable cosmetic container composition based on glycol-modified polyethylene terephthalate

Abstract

The present invention relates to a glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition comprising glycol-modified polyethylene terephthalate (PETG), a biodegradation promoter, a filler, and a processing aid, wherein the filler is kaolin with a surface coated with polyvinylpyrrolidone.

Description

Technology Field

[0001] The present invention relates to a biodegradable cosmetic container composition based on glycol-modified polyethylene terephthalate that not only possesses biodegradability but also can improve mechanical properties as a cosmetic container. Background Technology

[0003] Glycol-modified polyethylene terephthalate (PETG) is widely used in cosmetic containers, tubes, container bodies, caps, and dispensers due to its excellent impact resistance, chemical resistance, and moldability. However, glycol-modified polyethylene terephthalate is difficult to break down in the natural environment and is not easily accessible or ingested by microorganisms, so it can take hundreds of years to decompose.

[0004] To address this, a technology involving the incorporation of oxidizing agents or biodegradation promoters into glycol-modified polyethylene terephthalate has been proposed; however, issues remain, such as the induction of only initial oxidation without actual biodegradation, reduced mechanical strength, and stability problems related to cosmetic contents.

[0005] As an example of prior art, Korean Patent Registration No. 1541721 presents a biodegradable multilayer polymer reflector having a structure in which a first resin layer containing polylactic acid and a second resin layer containing an aromatic polyester or polyolefin are alternately laminated, wherein the difference in refractive index between the first resin layer and the second resin layer is 0.2 or more at 632.8 nm, the average thickness of the individual resin layers is 30 to 300 nm, and the biodegradability measured for 180 days according to KS M3100-1 is 40% or more.

[0006] However, even in the case of the above technology, there is a problem in that sufficient biodegradability and mechanical properties as a cosmetic container cannot be expected. Prior art literature

[0008] Republic of Korea Patent Registration No. 1541721 The problem to be solved

[0009] Therefore, the present invention has been devised to solve the aforementioned problems and aims to provide a glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition that is based on glycol-modified polyethylene terephthalate, ensures sufficient mechanical properties as a cosmetic container, and allows for the expectation of sufficient biodegradability after use. means of solving the problem

[0011] As a means to solve the aforementioned problems, the glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition of the present invention (hereinafter referred to as the "composition of the present invention") comprises glycol-modified polyethylene terephthalate (PETG), a biodegradation accelerator, a filler, and a processing aid, wherein the filler is characterized as being kaolin with a surface coated with polyvinylpyrrolidone.

[0012] As an example, it is characterized by further including a methyl methacrylate-butadiene-styrene copolymer.

[0013] As an example, the above-mentioned biodegradation promoter is characterized by including a microbial enzyme additive and a microbial inducer.

[0014] As one example, the above-mentioned biodegradation promoter is characterized by further including a photooxidizing agent.

[0015] As one example, the above microbial enzyme additive is characterized by being one or more of alkane hydroxylase, lipase, esterase, serine hydrolase, laccase, oxidase, aldehyde dehydrogenase, and alcohol dehydrogenase.

[0016] As one example, the above-mentioned microbial enzyme additive is characterized by being microencapsulated.

[0017] As an example, the microbial inducer is characterized by being one or more of starch, lignin, cellulose, lactide, aliphatic aromatic ester, and plant powder.

[0018] As an example, a microbial inducer is characterized by being esterified lignin.

[0019] delete

[0020] delete

[0021] As one example, the above kaolin is characterized by having its surface coated with polyethylene glycol terephthalate added to polyvinylpyrrolidone. Effects of the invention

[0023] As such, the present invention has the advantage of maintaining mechanical properties during use while enabling biodegradability after use. Brief explanation of the drawing

[0025] Figure 1 is a photograph showing glycol-modified polyethylene terephthalate as one composition of the present invention. FIG. 2 is a photograph showing a microbial enzyme additive as one composition of the present invention. FIG. 3 is a photograph showing a container manufactured by the composition of the present invention. Specific details for implementing the invention

[0026] In describing the present invention, terms and words used in this specification and claims must be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0028] The composition of the present invention is characterized by comprising glycol-modified polyethylene terephthalate (PETG), a biodegradation promoter, a filler, and a processing aid.

[0029] The above glycol-modified polyethylene terephthalate is an amorphous copolyester in which glycol (comonomer, usually CHDM) is introduced into PET to lower the degree of crystallinity.

[0030] In addition, the composition of the present invention further includes methyl methacrylate-butadiene-styrene copolymer (MBS) to compensate for the disadvantage of glycol-modified polyethylene terephthalate in terms of impact resistance compared to polyethylene.

[0031] Preferably, it is appropriate to formulate the mixture such that, for every 100 parts by weight of glycol-modified polyethylene terephthalate, 1 to 50 parts by weight of methyl methacrylate-butadiene-styrene copolymer, 1 to 50 parts by weight of biodegradation promoter, 1 to 50 parts by weight of filler, and 1 to 50 parts by weight of processing aid.

[0032] The glycol-modified polyethylene terephthalate above may be composed of an amorphous copolyester prepared by including one or more of 1,4-cyclohexanedimethanol (CHDM), neopentyl glycol (NPG), diethylene glycol (DEG), or polyethylene glycol (PEG) as comonomers.

[0033] Here, the above-mentioned biodegradation promoter includes a microbial enzyme additive and a microbial inducer, and preferably, it is appropriate to mix 10 to 20 parts by weight of the microbial enzyme additive with respect to 100 parts by weight of the microbial inducer.

[0034] As such, the present invention contributes to a substantial improvement in the biodegradation rate through a dual mechanism of microbial enzyme additives and microbial inducers, wherein the oxidative and hydrolytic decomposition of the surface of glycol-modified polyethylene terephthalate is accelerated by the microbial enzyme additive, and the microbial inducer rapidly forms microbial communities to shorten the decomposition rate.

[0035] The above microbial promoter directly provides microbial enzymes or similar active agents in the environment to accelerate oxidation, hydrolysis, and decomposition of the PETG matrix surface, and the above microbial enzyme additive is characterized by being one or more of alkane hydroxylase, lipase, esterase, serine hydrolase, laccase, oxidase, aldehyde dehydrogenase, and alcohol dehydrogenase.

[0036] The above-mentioned microbial enzyme additive improves the initial decomposition rate by converting low-molecular-weight glycol-modified polyethylene terephthalate fragments into a form that is easily ingested by microorganisms through the hydrophilization of the surface of the glycol-modified polyethylene terephthalate.

[0037] On the other hand, glycol-modified polyethylene terephthalate has a higher processing temperature compared to polyethylene, etc., so there may be a problem with the thermal denaturation of microbial enzyme additives during the processing.

[0038] Accordingly, the present invention provides an example in which thermal denaturation is controlled during the processing process by adding a microbial enzyme additive in a microencapsulated form.

[0039] Various known methods for microencapsulating microbial enzyme additives are presented here, and as an example, a powder form microencapsulated by spray drying can be applied.

[0040] To explain an example of microencapsulation of such microbial enzyme additives, a solution is prepared by dissolving 5 to 40 parts by weight of maltodextrin and 1 to 10 parts by weight of lactose in 100 parts by weight of water, and a feed solution is prepared by adding 0.1 to 10 parts by weight of microbial enzyme additive to 100 parts by weight of the solution, and then a microencapsulated microbial enzyme additive powder with an average particle size of 1 to 50 μm can be produced by spray drying under conditions of an inlet air temperature of 140 to 200°C and an exhaust air temperature of 60 to 100°C.

[0041] The above-mentioned microbial inducer is a component that actively promotes the attachment of microorganisms to the surface of glycol-modified polyethylene terephthalate and facilitates the formation of microbial colonies.

[0042] The above microbial inducer is characterized by being one or more of starch, lignin, cellulose, lactide, aliphatic aromatic ester, and plant powder.

[0043] It is reasonable to add lignin as a microbial inducer to promote dual microbial community formation while simultaneously controlling thermal denaturation of the matrix.

[0044] In the injection, extrusion, and blow molding processes of cosmetic containers, high temperatures of 180 to 230°C can cause thermal oxidation of the PETG matrix, and this thermal oxidation acts as a factor that degrades mechanical properties such as strength. Therefore, it is most desirable to add lignin to improve thermal stability.

[0045] In addition, the present invention provides an example in which esterified lignin is added as the microbial inducer.

[0046] While the above lignin particles are highly polar (rich in -OH groups), glycol-modified polyethylene terephthalate is non-polar and has low mutual affinity and compatibility, resulting in agglomeration. Problems such as deterioration due to stress concentration, crack initiation, and reduced low-temperature impact resistance occur around the aggregated particles.

[0047] To solve these problems, the present invention provides an example in which lignin is treated with fatty acid chloride or the like to introduce ester groups onto the surface, thereby increasing hydrophobicity and improving compatibility with glycol-modified polyethylene terephthalate.

[0048] The aliphatic esterification of lignin can be achieved by applying various known technologies; for example, it can be esterified by reacting with an aliphatic carboxylic acid anhydride. Specifically, lignin is dispersed in an organic solvent, and C8 to C 18 After adding fatty acid anhydride, by heating to 60–120°C in the presence of a catalyst such as pyridine or 4-dimethylaminopyridine (DMAP), aliphatic esterified lignin in which an aliphatic ester group is introduced to the hydroxyl group of lignin can be produced.

[0049] On the other hand, in the case of PETG, there may be a problem in that sufficient biodegradation effects cannot be expected using only the aforementioned microbial enzyme additives and microbial inducers, as the resistance to microbial / enzyme penetration is higher than that of PE and PP.

[0050] Accordingly, the present invention provides an example in which a photooxidizing agent is further added to the biodegradation promoter in addition to microbial enzyme additives and microbial inducers.

[0051] Preferably, it is appropriate to mix 10 to 20 parts by weight of a microbial enzyme additive and 5 to 10 parts by weight of a photooxidizing agent with respect to 100 parts by weight of a microbial inducer.

[0052] By adding more photooxidizing agents in this way, the PETG chains are partially cleaved by photooxidation by the photooxidizing agent during biodegradation and converted into low molecular weight fragments containing ester and carboxyl groups, allowing microbial enzyme additives to subsequently act on these fragments, thereby promoting the biodegradation reaction. In other words, by causing microcracks and low molecular weight oligomers to form on the PETG surface by the photooxidizing agent, the accessibility of microbial enzyme additives is doubled, thereby promoting the biodegradation reaction.

[0053] Here, various known substances may be used as photo-oxidizing agents, such as carbonyl organic photo-oxidizing agents like benzophenone, 4-hydroxybenzophenone, 4-methoxybenzophenone, acetophenone and their derivatives, benzoyl peroxide, and 2-hydroxy-2-methylpropiophenone.

[0054] The above filler is characterized by being one or more of talc, mica, and kaolin.

[0055] More preferably, kaolin is added as a filler. The addition of kaolin enables it to function as a microbial carrier by increasing the surface area for microbial colonization through its porous structure during biodegradation. In other words, since kaolin, as a filler, contains micropores between its layered structures to promote the attachment of microorganisms or enzymes, it enables a favorable effect in promoting biodegradation.

[0056] Meanwhile, adding kaolin as a filler is advantageous in terms of the microbial carrier as previously mentioned, but the adhesion between the matrix and the interface is reduced, which can lead to a decrease in mechanical properties due to peeling, etc. Accordingly, the present invention provides an example in which the deterioration of mechanical properties when added as a filler is controlled by coating the surface of kaolin with polyvinylpyrrolidone (hereinafter referred to as "PVP").

[0057] In other words, by adding kaolin surface-modified with PVP as a filler, the kaolin is well dispersed during use and storage as a container, and the interfacial adhesion with PET is good so that strength and impact resistance are maintained, while during biodegradation, that is, when exposed to soil and moisture after disposal, the surface-modified layer is gradually broken or dissolved by moisture or microorganisms, exposing the porous surface of the kaolin so that it functions as a microorganism carrier.

[0058] Meanwhile, since PVP is hydrophilic and may have weak interfacial bonding with non-polar PETG, the present invention provides an example in which polyethylene glycol terephthalate is added in addition to PVP as a surface modifier for kaolin.

[0059] Polyethylene glycol terephthalate (hereinafter referred to as "PET-PEG") has high compatibility within the PETG substrate, thereby strengthening interfacial bonding and improving mechanical strength, and the PEG segments can promote long-term biodegradation.

[0060] In other words, PVP is a hydrophilic water-soluble polymer that improves the dispersibility of fillers when coated on the surface of kaolin particles. When the container is discarded and exposed to soil or a moist environment, it is removed by dissolving or swelling due to moisture, thereby exposing the porous surface of the kaolin and providing it with the function of a microbial carrier. However, since PVP has relatively low compatibility with the base resin PETG, the effect of improving interfacial adhesion is limited, and thus it is insufficient to adequately compensate for mechanical properties such as tensile strength and impact resistance that are reduced by the filler.

[0061] Accordingly, in the present invention, by including PET-PEG in addition to PVP, the interfacial adhesion is improved, thereby significantly supplementing mechanical properties such as tensile strength and impact resistance compared to a PVP-only coating. At the same time, after disposal, the accessibility of moisture and microorganisms is doubled by the PEG segments in both PVP and PET-PEG, thereby exposing the porous structure of kaolin and enabling the expression of a function that promotes biodegradation as a microorganism carrier.

[0062] Various known methods can be applied to surface modification of the kaolin surface with PVP and PET-PEG, for example, by (i) a step of preparing a mixed solution by adding 3 to 15 parts by weight of PVP, 2 to 8 parts by weight of PET-PEG, and 0.1 to 1 part by weight of a nonionic surfactant to 100 parts by weight of water into a container and then applying shearing for 10 to 60 minutes at a stirring speed of 500 to 1,500 rpm at a temperature of 70 to 95°C; (ii) a step of mixing and dispersing 80 to 200 parts by weight of kaolin to 100 parts by weight of the mixed solution; and (iii) a step of removing the solvent from the mixed solution.

[0063] The above processing aid is characterized by being one or more of polyethylene wax, oxidized polyethylene wax, and fatty acid amides.

[0065] The embodiments of the present invention are described below through experimental examples. In the following examples, the lipase added as a microbial enzyme additive was prepared by adding 3 parts by weight of lipase to 100 parts by weight of a solution prepared by dissolving 30 parts by weight of maltodextrin and 5 parts by weight of lactose in 100 parts by weight of water, and then spray-drying the solution under conditions of an inlet air temperature of 140 to 200°C and an exhaust air temperature of 60 to 100°C to add microencapsulated lipase powder with an average particle size of 1 to 50 μm.

[0067] <Example 1>

[0068] A sample was prepared by mixing 20 parts by weight of methyl methacrylate-butadiene-styrene copolymer, 20 parts by weight of biodegradation accelerator, 20 parts by weight of talc, and 5 parts by weight of fatty acid amide for every 100 parts by weight of glycol-modified polyethylene terephthalate, wherein the biodegradation accelerator was mixed with 15 parts by weight of lipase and 5 parts by weight of benzophenone for every 100 parts by weight of lactide.

[0070] <Example 2>

[0071] A sample was prepared by mixing 20 parts by weight of methyl methacrylate-butadiene-styrene copolymer, 20 parts by weight of biodegradation accelerator, 20 parts by weight of talc, and 5 parts by weight of fatty acid amide for every 100 parts by weight of glycol-modified polyethylene terephthalate, wherein the biodegradation accelerator was mixed with 15 parts by weight of lipase and 5 parts by weight of benzophenone for every 100 parts by weight of lignin.

[0073] <Example 3>

[0074] The composition is formulated to include 20 parts by weight of methyl methacrylate-butadiene-styrene copolymer, 20 parts by weight of biodegradation accelerator, 20 parts by weight of talc, and 5 parts by weight of fatty acid amide per 100 parts by weight of glycol-modified polyethylene terephthalate, wherein the biodegradation accelerator is formulated to include 15 parts by weight of lipase and 5 parts by weight of benzophenone per 100 parts by weight of lignin, and wherein esterified lignin is added to the lignin.

[0075] Here, for esterified lignin, 10g of lignin is added to a 500mL flask, 100g of pyridine is added and stirred for about 30 minutes under heating at 40℃, then 30g of lauric anhydride and 0.5g of 4-dimethylaminopyridine are added sequentially, the flask is heated to 80℃, and a stirring reaction is carried out under a nitrogen atmosphere for 3 to 6 hours.

[0076] Next, the flask was cooled to room temperature, and the reaction mixture was slowly poured into 1 L of 0.1 N aqueous hydrochloric acid solution diluted in ice water. Then, the precipitated solid was filtered, and the filtered solid was washed 3 to 5 times with distilled water. After drying the washed precipitate in a vacuum oven at about 60°C for 24 hours, an aliphatic esterified lignin with an average particle size of 10 to 50 μm was prepared using a grinder.

[0078] <Example 4>

[0079] A sample was prepared by mixing 20 parts by weight of methyl methacrylate-butadiene-styrene copolymer, 20 parts by weight of biodegradation accelerator, 20 parts by weight of kaolin, and 5 parts by weight of fatty acid amide for every 100 parts by weight of glycol-modified polyethylene terephthalate, wherein the biodegradation accelerator is mixed with 15 parts by weight of lipase and 5 parts by weight of benzophenone for every 100 parts by weight of lignin.

[0081] <Example 5>

[0082] A mixture is formulated to include 20 parts by weight of methyl methacrylate-butadiene-styrene copolymer, 20 parts by weight of biodegradation accelerator, 20 parts by weight of kaolin, and 5 parts by weight of fatty acid amide per 100 parts by weight of glycol-modified polyethylene terephthalate, wherein the biodegradation accelerator is formulated to include 15 parts by weight of lipase and 5 parts by weight of benzophenone per 100 parts by weight of lignin, and the kaolin is modified to PVP. The modification comprises: (i) a step of preparing a mixed solution by adding 10 parts by weight of PVP and 0.3 parts by weight of a nonionic surfactant per 100 parts by weight of water to a container and applying shearing for 30 minutes at a stirring speed of approximately 1,000 rpm at a temperature of 70 to 95°C; and (ii) a step of mixing and dispersing 90 parts by weight of kaolin per 100 parts by weight of the mixed solution. (iii) a step of removing the solvent from the above mixed solution; was prepared by passing through this step.

[0084] <Example 6>

[0085] A mixture is formulated to include 20 parts by weight of methyl methacrylate-butadiene-styrene copolymer, 20 parts by weight of biodegradation accelerator, 20 parts by weight of kaolin, and 5 parts by weight of fatty acid amide per 100 parts by weight of glycol-modified polyethylene terephthalate, wherein the biodegradation accelerator is formulated to include 15 parts by weight of lipase and 5 parts by weight of benzophenone per 100 parts by weight of lignin, and wherein the kaolin is modified with PVP and PET-PEG. The modification comprises: (i) a step of preparing a mixed solution by adding 10 parts by weight of PVP, 3 parts by weight of PET-PEG, and 0.3 parts by weight of a nonionic surfactant per 100 parts by weight of water to a container, and then applying shearing for 30 minutes at a stirring speed of approximately 1,000 rpm at a temperature of 70 to 95°C; and (ii) a step of mixing and dispersing 90 parts by weight of kaolin per 100 parts by weight of the mixed solution. (iii) a step of removing the solvent from the above mixed solution; was prepared by passing through this step.

[0087] <Impact Resistance and Biodegradability Test>

[0088] After dry blending the above samples, pellets were prepared by melt-kneading in a twin-screw extruder (cylinder temperature: 160~190℃, screw rotation speed: 200 rpm).

[0089] First, impact test specimens (KS M ISO 180, notch impact) were prepared using a single-axis injection molding machine (cylinder temperature: 170~200℃, mold temperature: 25℃) from the pellets manufactured for the impact strength test. The specimens were subjected to impact strength tests at a test temperature of 23±2℃, a specimen thickness of 3.0mm, and a V-notch depth of 2mm, and the results are shown in Table 1.

[0090] Next, for the biodegradation experiment, the pellets were crushed to a powder with an average particle size of ≤2 mm. The powdered pellets were irradiated with ultraviolet light using a UVA-340 lamp at 60±2℃ for 8 hours, followed by a 12-hour cycle repeated 20 times with a condensation (wetting) stage at 50±2℃ for 4 hours. Then, 10% by weight of the pellet powder relative to the compost and inoculum was added, and the experiment was conducted for 90 days at a temperature of 58±2℃ (ISO 14855-1 standard composting temperature) and with a moisture content of 50~60%. The experiment calculated the biodegradability by deriving the amount of CO2 generated from the actual sample based on the theoretically generated amount of CO2, and the results are shown in Table 1.

[0092] division Notch impact strength (kJ / ㎡) Biodegradability (%) Example 1 4.2 33 Example 2 5.0 33 Example 3 5.5 31 Example 4 3.8 42 Example 5 4.2 40 Example 6 5.1 39

[0094] Comparing Example 1 and Example 2, it can be seen that Example 2 is advantageous in terms of impact strength, which is attributed to the fact that lignin, as a microbial inducer, is advantageous in high-temperature stability compared to lactide. Additionally, it can be seen that Example 3 is more advantageous in terms of impact strength than Example 2, which is attributed to the improvement in compatibility with glycol-modified polyethylene terephthalate due to the addition of esterified lignin.

[0095] Comparing Example 2 and Example 4, it can be seen that Example 4 is advantageous in terms of biodegradability. This is attributed to the fact that, unlike Example 2 which contains talc as a filler, Example 4 contains porous kaolin, which functions as a microbial carrier during biodegradation. However, it can be seen that it is disadvantageous in terms of impact strength. This is attributed to the reduced adhesion between the matrix and the interface due to the porosity of the kaolin.

[0096] Accordingly, in the case of Example 5, kaolin is added, and the kaolin is surface-modified with PVP, so that the biodegradability is maintained at almost the same level while an advantageous effect is exhibited in terms of impact strength. In particular, in the case of Example 6, the kaolin is surface-modified with PVP and PET-PEG, so that not only is the biodegradability maintained but an even more advantageous effect is exhibited in terms of impact strength.

[0098] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

Claims

Claim 1 A glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition comprising glycol-modified polyethylene terephthalate (PETG), a biodegradation promoter, a filler, and a processing aid, wherein the filler is kaolin with a surface coated with polyvinylpyrrolidone. Claim 2 A glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition according to claim 1, further comprising a methyl methacrylate-butadiene-styrene copolymer. Claim 3 A glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition according to claim 1, wherein the biodegradation promoter comprises a microbial enzyme additive and a microbial inducer. Claim 4 A glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition according to claim 3, characterized in that the biodegradation promoter further comprises a photooxidizing agent. Claim 5 A glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition according to claim 3, wherein the microbial enzyme additive is one or more of alkane hydroxylase, lipase, esterase, serine hydrolase, laccase, oxidase, aldehyde dehydrogenase, and alcohol dehydrogenase. Claim 6 A glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition characterized in that, in claim 5, the microbial enzyme additive is microencapsulated. Claim 7 A glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition according to claim 3, characterized in that the microbial inducer is one or more of starch, lignin, cellulose, lactide, aliphatic aromatic ester, and plant powder. Claim 8 A glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition characterized in that, in claim 7, the microbial inducer is esterified lignin. Claim 9 delete Claim 10 delete Claim 11 A glycol-modified polyethylene terephthalate-based biodegradable cosmetic container composition according to claim 1, wherein the surface of the kaolin is coated by adding polyethylene glycol terephthalate to polyvinylpyrrolidone.

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