Acrylic copolymer, resin composition, and molded article

Abstract

The present invention relates to an acrylic copolymer, a resin composition same, and a biodegradable molded article, wherein the acrylic copolymer can enhance mechanical properties of a resin composition by improving compatibility between different kinds of biodegradable resins when applied as a chemical compatibilizer for improving compatibility between different kinds of biodegradable resins.

Description

Acrylic copolymers, resin compositions and molded articles

[0001] [Cross-citation with related applications]

[0002] This invention claims the benefit of priority to Korean Patent Application No. 10-2023-0165581, filed November 24, 2023, the entire contents of which are incorporated herein by reference.

[0003] [Technical Field]

[0004] The present invention relates to an acrylic copolymer, a resin composition, and a biodegradable molded article molded therefrom.

[0005] Thermoplastic resins have excellent mechanical and chemical properties and are used in a variety of fields, including drinking water containers, medical and food packaging, food containers, automotive moldings, and agricultural vinyl.

[0006] Among these, polyethylene films have excellent mechanical properties, are harmless to the human body, and can be continuously deformed when heat is applied, so they are mainly used as hot sealing bags for food packaging and mulching films for agricultural use.

[0007] Hot sealing bags for food packaging are widely used for vacuum packaging of foods, etc., and polyethylene film is mainly used because it can achieve excellent bonding strength even at low sealing temperatures.

[0008] Agricultural mulching films are primarily used in mulching farming. Mulching is a material used to cover the soil surface during crop cultivation. Covering the topsoil with various types of materials can inhibit the growth of weeds, prevent pests and diseases, and thus reduce pesticide use. Furthermore, they can easily regulate soil temperature, promote the growth of beneficial bacteria, prevent soil erosion, and maintain soil moisture. These mulching materials can be made from crop leaves such as straw or grass, or from polyolefin films. Synthetic resins such as polyethylene films are the most commonly used.

[0009] However, polyethylene film does not decompose in the natural environment, and recycling is limited. In particular, the recent phenomenon of discarded plastics, such as polyethylene film, flowing into the ocean and being broken down into tiny microplastics by ocean currents and sunlight has become a growing problem. Countless billions, if not hundreds of billions, of these microplastics are known to float in the ocean. They enter the bodies of marine life, accumulate within ecosystems, and impact the entire food chain.

[0010] Accordingly, interest in biodegradable plastics has recently increased. Among these, polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA) are attracting attention as biodegradable plastics, and ongoing efforts are being made to improve the compatibility of PBAT and PLA in biodegradable resin compositions containing both.

[0011] Compatibilizers for biodegradable resin compositions containing PBAT and PLA can be categorized into physical and chemical compatibilizers based on their operating principles. A typical physical compatibilizer is a copolymer containing PBAT or PLA. However, the use of such physical compatibilizers can lead to deterioration of mechanical properties, as they function similarly to plasticizers.

[0012] Meanwhile, Patent Publication No. 10-2045863 (Patent Document 1) discloses a biodegradable polyester film comprising a copolymer containing an epoxy group and based on styrene, acrylic acid ester, and / or methacrylic acid ester. When the copolymer disclosed in Patent Document 1 is used as a compatibilizer for PBAT and PLA, when used in an amount exceeding a certain amount, not only does PBAT-g-PLA form at the interface between PBAT and PLA, but also a large amount of PBAT-g-PBAT and / or PLA-g-PLA is formed in each resin, which causes a problem of rapidly increasing the viscosity of the resin composition. Since this rapid viscosity increase is difficult to control during processing of the resin composition, it limits the expansion of the uses of the resin composition. Therefore, in a biodegradable resin composition containing different biodegradable resins, it is important to secure a compatibilizer that maintains performance as a chemical compatibilizer while controlling the viscosity increase within an appropriate range to ensure processability.

[0013] [Prior Art Literature]

[0014] [Patent Document]

[0015] (Patent Document 1) KR 10-2045863 B1

[0016] The present invention has been devised to solve the problems of the above-mentioned prior art, and aims to provide an acrylic copolymer that can function as a chemical compatibilizer to improve compatibility between different types of biodegradable resins.

[0017] In addition, the present invention aims to provide a resin composition having excellent processability by improving mechanical properties through improving compatibility between different biodegradable resins by applying the acrylic copolymer as a chemical compatibilizer, while suppressing a dramatic increase in viscosity.

[0018] In addition, the present invention aims to provide a molded product that is molded from the resin composition and exhibits biodegradability.

[0019] To solve the above problem, the present invention provides a resin composition and a molded product.

[0020] (1) The present invention provides an acrylic copolymer comprising an alkyl (meth)acrylate monomer unit and a (meth)acrylate monomer unit including an epoxy group, having an epoxy equivalent weight (EEW) of 100 g / eq or more and 1,000 g / eq or less, an epoxy number per molecule based on number average molecular weight (Efn) of 30 or more and 80 or less, and an epoxy number per molecule based on weight average molecular weight (Efw) of 20 or more and 170 or less.

[0021] (2) The present invention provides an acrylic copolymer according to (1) above, wherein the acrylic copolymer has an epoxy equivalent weight (EEW) of 250 g / eq or more and 750 g / eq or less.

[0022] (3) The present invention provides an acrylic copolymer having a number average molecular weight of 5,000 g / mol or more and 50,000 g / mol or less in (1) or (2).

[0023] (4) The present invention provides an acrylic copolymer having a number average molecular weight of 10,000 g / mol or more and 20,000 g / mol or less in any one of the above (1) to (3).

[0024] (5) The present invention provides an acrylic copolymer having a weight average molecular weight of 5,000 g / mol or more and 100,000 g / mol or less in any one of the above (1) to (4).

[0025] (6) The present invention provides an acrylic copolymer having a weight average molecular weight of 15,000 g / mol or more and 40,000 g / mol or less in any one of the above (1) to (5).

[0026] (7) The present invention provides an acrylic copolymer in any one of the above (1) to (6), wherein the acrylic copolymer has an epoxy number per molecule (Efn) based on the number average molecular weight of 35 or more and 70 or less.

[0027] (8) The present invention provides an acrylic copolymer in any one of the above (1) to (7), wherein the acrylic copolymer has an epoxy number per molecule (Efw) based on the weight average molecular weight of 70 or more and 140 or less.

[0028] (9) The present invention provides an acrylic copolymer according to any one of the above (1) to (8), wherein the acrylic copolymer comprises 40 wt% or more and 75 wt% or less of an alkyl (meth)acrylate monomer unit and 25 wt% or more and 60 wt% or less of a (meth)acrylate monomer unit containing an epoxy group.

[0029] (10) The present invention provides an acrylic copolymer in any one of the above (1) to (9), wherein the alkyl (meth)acrylate monomer unit includes a methyl (meth)acrylate monomer unit and an alkyl (meth)acrylate monomer unit having 2 to 10 carbon atoms.

[0030] (11) The present invention provides an acrylic copolymer according to any one of the above (1) to (10), wherein the acrylic copolymer comprises 10 wt% or more and 65 wt% or less of a methyl (meth)acrylate monomer unit, 25 wt% or more and 60 wt% or less of a (meth)acrylate monomer unit containing an epoxy group, and 5 wt% or more and 60 wt% or less of an alkyl (meth)acrylate monomer unit having 2 to 10 carbon atoms.

[0031] (12) The present invention provides an acrylic copolymer according to any one of the above (1) to (11), wherein the acrylic copolymer comprises a methyl methacrylate monomer unit, a glycidyl methacrylate monomer unit, and an alkyl (meth)acrylate monomer unit having 4 to 8 carbon atoms.

[0032] (13) The present invention provides a resin composition comprising at least one of a first biodegradable resin and a second biodegradable resin, an acrylic copolymer, and a compatibilizer formed from the acrylic copolymer, wherein the acrylic copolymer is an acrylic copolymer according to any one of (1) to (12).

[0033] (14) The present invention provides a molded product molded from a resin composition according to (13) above.

[0034] The acrylic copolymer of the present invention functions as a chemical compatibilizer for improving compatibility between different types of biodegradable resins, thereby improving the mechanical properties of a resin composition through improving compatibility between different types of biodegradable resins.

[0035] In addition, when the acrylic copolymer of the present invention is applied as a chemical compatibilizer, it is possible to suppress a dramatic increase in viscosity during processing of a resin composition, thereby preventing a decrease in the processability of the resin composition, and furthermore, the amount used can be freely adjusted within a relatively wide range, making it particularly useful for developing resin compositions for various purposes.

[0036] Hereinafter, the present invention will be described in more detail to help understand the present invention.

[0037] The terms or words used in the description and claims of the present invention should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0038] In the present invention, the term 'monomer unit' may indicate a component, structure, or substance itself derived from a monomer, and as a specific example, may mean a repeating unit formed within a polymer by a monomer introduced during polymerization of the polymer and participating in the polymerization reaction.

[0039] The term 'composition' as used in the present invention includes a mixture of materials comprising the composition as well as reaction products and decomposition products formed from the materials of the composition.

[0040]

[0041] The present invention provides an acrylic copolymer.

[0042] According to one embodiment of the present invention, the acrylic copolymer can function as a chemical compatibilizer for a resin composition comprising a heterogeneous biodegradable resin.

[0043] According to one embodiment of the present invention, the acrylic copolymer may include an alkyl (meth)acrylate monomer unit and a (meth)acrylate monomer unit including an epoxy group, and may have an epoxy equivalent weight (EEW) of 100 g / eq or more and 1,000 g / eq or less, an epoxy number per molecule (Efn) based on number average molecular weight of 30 or more and 80 or less, and an epoxy number per molecule (Efw) based on weight average molecular weight of 20 or more and 170 or less.

[0044] According to one embodiment of the present invention, the acrylic copolymer, in addition to controlling the monomer type and the epoxy equivalent in the copolymer, simultaneously controls the number of epoxy molecules per molecule (Efn) based on the number average molecular weight and the number of epoxy molecules per molecule (Efw) based on the weight average molecular weight, thereby improving compatibility when applied as a chemical compatibilizer to a resin composition containing different types of biodegradable resins, suppressing a dramatic increase in viscosity and preventing a decrease in processability, and enabling the amount used to be freely adjusted within a relatively wide range.

[0045] According to one embodiment of the present invention, the acrylic copolymer may be an acrylic copolymer copolymerized with an alkyl (meth)acrylate monomer and a (meth)acrylate monomer having an epoxy group. As a specific example, the acrylic copolymer may be a random copolymer copolymerized with an alkyl (meth)acrylate monomer and a (meth)acrylate monomer having an epoxy group, and may be a linear random copolymer. Here, '(meth)acrylate' means both acrylate and methacrylate.

[0046] According to one embodiment of the present invention, the alkyl (meth)acrylate monomer unit may include a methyl (meth)acrylate monomer unit and an alkyl (meth)acrylate monomer unit having 2 to 10 carbon atoms. When the alkyl (meth)acrylate monomer unit simultaneously includes a methyl (meth)acrylate monomer unit and an alkyl (meth)acrylate monomer unit having 2 to 10 carbon atoms, the flexibility of the polymer chain can be further increased.

[0047] According to one embodiment of the present invention, the acrylic copolymer may contain alkyl (meth)acrylate monomer units formed from alkyl (meth)acrylate monomers in an amount of 40 wt% or more and 75 wt% or less. As a specific example, the acrylic copolymer may contain alkyl (meth)acrylate monomer units formed from alkyl (meth)acrylate monomers in an amount of 40 wt% or more, 45 wt% or more, or 50 wt% or more, and further may contain 75 wt% or less, or 70 wt% or less, and within this range, the flexibility of the polymer chain can be further increased, the miscibility with PLA is excellent, and the compatibility with PBAT is relatively excellent, so that the compatibility between PBAT and PLA can be further improved, and when a film is manufactured from the resin composition, chain diffusion and entanglement between film interfaces can be increased.

[0048] According to one embodiment of the present invention, the acrylic copolymer may contain a (meth)acrylate monomer unit including an epoxy group formed from a (meth)acrylate monomer including an epoxy group in an amount of 25 wt% or more and 60 wt% or less. As a specific example, the acrylic copolymer may contain a (meth)acrylate monomer unit including an epoxy group formed from a (meth)acrylate monomer including an epoxy group in an amount of 25 wt% or more, or 30 wt% or more, and further may contain a content of 60 wt% or less, 55 wt% or less, 50 wt% or less, 45 wt% or less, or 40 wt% or less, and within this range, the flexibility of the polymer chain can be increased, the compatibility between different biodegradable resins can be further improved, and in particular, when a film is manufactured from the resin composition, chain diffusion and entanglement between film interfaces can be increased.

[0049] According to one embodiment of the present invention, the (meth)acrylate monomer containing an epoxy group may be a (meth)acrylate monomer containing a glycidyl group, and a specific example thereof may be a glycidyl (meth)acrylate monomer. The (meth)acrylate monomer containing an epoxy group may function as a chemical compatibilizer by reacting the epoxy group contained in the monomer with a hydroxyl group (-OH) or a carboxylic acid group (-COOH) contained in PBAT or PLA. In addition, when the reaction occurs at the interface between PBAT and PLA, the compatibility and interfacial adhesiveness between PBAT and PLA may be further improved.

[0050] According to one embodiment of the present invention, when the alkyl (meth)acrylate monomer unit includes a methyl (meth)acrylate monomer unit and an alkyl (meth)acrylate monomer unit having 2 to 10 carbon atoms, the acrylic copolymer may include a methyl (meth)acrylate monomer unit formed from the methyl (meth)acrylate monomer in an amount of 10 wt% or more and 65 wt% or less. As a specific example, the acrylic copolymer may contain methyl (meth)acrylate monomer units formed from methyl (meth)acrylate monomers in an amount of 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, or 35 wt% or more, and may also contain 65 wt% or less, 60 wt% or less, 55 wt% or less, or 50 wt% or less, and within this range, the copolymer has excellent compatibility with PLA and relatively excellent compatibility with PBAT, so that the compatibility of PBAT and PLA can be further improved.

[0051] According to one embodiment of the present invention, when the alkyl (meth)acrylate monomer unit includes a methyl (meth)acrylate monomer unit and an alkyl (meth)acrylate monomer unit having 2 to 10 carbon atoms, the acrylic copolymer may include an alkyl (meth)acrylate monomer unit having 2 to 10 carbon atoms formed from an alkyl (meth)acrylate monomer having 2 to 10 carbon atoms in an amount of 5 wt% to 60 wt%. As a specific example, the acrylic copolymer may contain 5 wt% or more, 6 wt% or more, 7 wt% or more, 8 wt% or more, 9 wt% or more, 10 wt% or more, 11 wt% or more, 12 wt% or more, 13 wt% or more, 14 wt% or more, or 15 wt% or more of an alkyl (meth)acrylate monomer unit having 2 to 10 carbon atoms formed from an alkyl (meth)acrylate monomer having 2 to 10 carbon atoms, and may also contain 60 wt% or less, 55 wt% or less, 50 wt% or less, 45 wt% or less, 40 wt% or less, 35 wt% or less, 30 wt% or less, 25 wt% or less, or 20 wt% or less, and within this range, the flexibility of the polymer chain can be increased and the compatibility between different biodegradable resins can be further improved. In particular, when a film is manufactured from a resin composition, chain diffusion and entanglement between film interfaces can be increased.

[0052] According to one embodiment of the present invention, the alkyl (meth)acrylate monomer having 2 to 10 carbon atoms may be at least one selected from the group consisting of ethyl (meth)acrylate, n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, iso-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, iso-decyl (meth)acrylate, dodecyl (meth)acrylate, iso-bornyl (meth)acrylate, and lauryl (meth)acrylate. As a specific example, the alkyl (meth)acrylate monomer having 2 to 10 carbon atoms may be an alkyl (meth)acrylate monomer having 3 to 9 carbon atoms, or 4 to 8 carbon atoms, and as a more specific example, may be at least one selected from the group consisting of butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate.

[0053] According to one embodiment of the present invention, the acrylic copolymer may include a methyl methacrylate monomer unit, a glycidyl methacrylate monomer unit, and an alkyl (meth)acrylate monomer unit having 4 to 8 carbon atoms, and the content of each monomer unit may be appropriately selected according to the desired resin composition within the content range described above.

[0054] According to one embodiment of the present invention, the acrylic copolymer can be produced by emulsion polymerization of a monomer mixture including the alkyl (meth)acrylate monomer and the (meth)acrylate monomer including an epoxy group, and a polymerization composition including a polymerization initiator and an emulsifier.

[0055] According to one embodiment of the present invention, when polymerizing the acrylic copolymer, the polymerization temperature and polymerization time can be performed as needed, and as a specific example, the polymerization can be performed within a polymerization temperature range of 50°C or more and 200°C or less with a polymerization time of 0.5 hours or more and 20 hours or less.

[0056] According to one embodiment of the present invention, the polymerization initiator may be an inorganic or organic peroxide, and specific examples thereof include water-soluble polymerization initiators including potassium persulfate, sodium persulfate, ammonium persulfate, and the like, and oil-soluble polymerization initiators including cumene hydroperoxide, benzoyl peroxide, and the like.

[0057] According to one embodiment of the present invention, an activator may be used together with the polymerization initiator to promote the initiation of the reaction of the peroxide, and as such an activator, at least one selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediaminetetraacetate, ferrous sulfate, and dextrose may be used.

[0058] According to one embodiment of the present invention, the polymerization initiator may be added in an amount of 0.1 to 10 parts by weight, and as a specific example, 0.1 to 5 parts by weight, based on 100 parts by weight of the monomer mixture on a dry weight basis.

[0059] According to one embodiment of the present invention, the polymerization may be carried out by further including a chain transfer agent (or, chain transfer agent) from the viewpoint of increasing the efficiency of the polymerization reaction. The chain transfer agent may play a role in introducing homopolymers, which are polymers composed of only one type of monomer, into micelles during the polymerization process. The chain transfer agent may be a straight-chain or branched-chain alkylthiol compound having 5 to 20 carbon atoms, and specific examples thereof include hexanethiol, cyclohexanethiol, adamantanethiol, heptanethiol, octanethiol, nonanethiol, decanethiol, undecanethiol, dodecanethiol, hexadecanethiol, octadecanethiol, and the like. In addition, the chain transfer agent may be introduced in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the monomer mixture on a dry weight basis, and specific examples thereof include 0.1 to 5 parts by weight.

[0060] According to one embodiment of the present invention, the emulsion polymerization may be performed including the following steps (S10) to (S30).

[0061] (S10) Step: A step of preparing an emulsion by dispersing an emulsifier in a solvent.

[0062] (S20) Step: A step of preparing a pre-emulsion by mixing a monomer mixture containing each monomer component and an emulsifier, etc.

[0063] (S30) Step: A step of mixing the emulsion prepared in the step (S10) and the pre-emulsion prepared in the step (S20) in the presence of a polymerization initiator and performing emulsion polymerization.

[0064] According to one embodiment of the present invention, emulsion polymerization for polymerizing the acrylic copolymer can be performed according to steps (S10) to (S30).

[0065] First, in step (S10), an emulsion containing an emulsifier is prepared. This is separate from the pre-emulsion preparation process below. The emulsifier may be an anionic emulsifier alone or may include an anionic emulsifier, a cationic emulsifier, and a nonionic emulsifier. By mixing these emulsifier components with a solvent such as water, an emulsion may be prepared. During the emulsion preparation process, micelle initial particles having a size of several nanometers can be stably formed. Then, in step (S20), a pre-emulsion is prepared by mixing the above-described monomer mixture with water to prepare the pre-emulsion. At this time, as the emulsifier, an anionic emulsifier may be used alone or an anionic emulsifier and the above-described nonionic emulsifier may be used together. In this process, nano-sized latex particles can be formed within the pre-emulsion. That is, the above-described emulsifier can be used in at least one of the emulsion preparation step and the pre-emulsion preparation step. Then, in step (S30), after a polymerization initiator is added to the prepared emulsion, the pre-emulsion and the polymerization initiator are continuously added at equal ratios for a predetermined period of time.

[0066] The content of the polymerization initiator added to the above emulsion may be 0 to 1 part by weight based on 100 parts by weight of the monomer mixture, and the content of the polymerization initiator added together with the pre-emulsion may be 0.1 to 2 parts by weight based on 100 parts by weight of the monomer mixture, and the time of the continuous addition may be about 3 to about 7 hours. Through this process, the floating monomers or polymers in the pre-emulsion may be introduced into the initial particles generated in the emulsion. The results of this reaction may then undergo a process of heating polymerization in the presence of an additional polymerization initiator, through which the polymerization of the remaining monomers occurs. At this time, the polymerization initiator may be additionally added in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the monomer mixture, and the heating polymerization may be performed at a temperature of about 75°C to about 85°C for about 40 to about 80 minutes. This emulsion polymerization method is divided into an emulsion preparation process and a pre-emulsion preparation process, and can be performed by a simple method of mixing the pre-emulsion into the emulsion thereafter, thereby improving process stability and productivity compared to conventional methods.

[0067] The emulsifier used in the above emulsion polymerization may include at least one selected from the group consisting of anionic emulsifiers, cationic emulsifiers, and nonionic emulsifiers. The emulsifier is a substance having both a hydrophilic group and a hydrophobic group, and forms a micelle structure during the emulsion polymerization process, allowing polymerization of each monomer to occur within the micelle structure. Emulsifiers commonly used in emulsion polymerization can be divided into anionic emulsifiers, cationic emulsifiers, and nonionic emulsifiers, and two or more types may be mixed and used in terms of polymerization stability in emulsion polymerization. As a specific example, the nonionic emulsifier may include at least one selected from the group consisting of polyethylene oxide alkyl aryl ether, polyethylene oxide alkyl amine, and polyethylene oxide alkyl ester. In addition, the anionic emulsifier may include at least one selected from the group consisting of sodium alkyl diphenyl ether disulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene aryl ether sulfate, sodium alkyl sulfate, sodium alkyl benzene sulfonate, and dialkyl sodium sulfosuccinate. These may be used alone or in combination of two or more, and may be more effective when an anionic emulsifier and a nonionic emulsifier are used in combination. In addition, the emulsifier may be used in an amount of about 0.1 part by weight to about 10 parts by weight, or about 1 part by weight to about 5 parts by weight, based on 100 parts by weight of the total monomer components used in the production of the latex particles.

[0068] According to one embodiment of the present invention, the polymerization composition may further include an aqueous solvent such as water, in addition to the emulsifier or monomer component. At this time, the aqueous solvent may be used in an amount of about 10 to about 1,000 parts by weight based on 100 parts by weight of the latex particles, in terms of stability and viscosity control of the latex particles, and may be used so that the total solid content (TSC) is controlled to about 10% by weight to about 60% by weight based on the total amount of the composition.

[0069] According to one embodiment of the present invention, the acrylic copolymer may have an epoxy equivalent weight (EEW) of 100 g / eq or more and 1,000 g / eq or less. As a specific example, the acrylic copolymer may have an epoxy equivalent weight (EEW) of 100 g / eq or more, 110 g / eq or more, 120 g / eq or more, 130 g / eq or more, 140 g / eq or more, 150 g / eq or more, 160 g / eq or more, 170 g / eq or more, 180 g / eq or more, 190 g / eq or more, 200 g / eq or more, 210 g / eq or more, 220 g / eq or more, 230 g / eq or more, 240 g / eq or more, 250 g / eq or more, 260 g / eq or more, 270 g / eq or more, or 280 g / eq or more, and 1,000 g / eq or less, 950 g / eq or less, 900 g / eq or less Below, it may be 850 g / eq or less, 800 g / eq or less, 750 g / eq or less, 700 g / eq or less, 650 g / eq or less, 600 g / eq or less, 550 g / eq or less, or 500 g / eq or less, and within this range, the compatibility between different biodegradable resins can be further improved. In particular, when the biodegradable resin is a polyester-based resin, it can effectively react with a hydroxyl group or a carboxylic acid group of the polyester-based resin to further improve its performance as a chemical compatibilizer. The epoxy equivalent may be calculated using the following Equation 3 based on the number average molecular weight (Mn) value and the number of epoxy molecules per molecule based on the number average molecular weight (Efn) for the acrylic copolymer, and the part after the decimal point may be rounded off and expressed. Here, the epoxy equivalent refers to the equivalent of an epoxy group in a polymer and / or copolymer containing an epoxy group, and is expressed as the number of grams of epoxy groups contained in 1 mol of the polymer and / or copolymer, and is expressed as g / mol or g / eq. The present invention expresses the unit of the epoxy equivalent as g / eq, which is equivalent to g / mol, according to a conventional method.

[0070] [Formula 3]

[0071] EEW(g / eq) = Mn (g / mol) / Efn

[0072] In the above equation 3, Efn is the number of epoxy molecules per molecule (Efn) based on the number average molecular weight described below.

[0073] According to one embodiment of the present invention, the number average molecular weight may be 5,000 g / mol or more and 50,000 g / mol or less. As a specific example, the acrylic copolymer may have a weight average molecular weight of 5,000 g / mol or more, 10,000 g / mol or more, 15,000 g / mol or more, or 20,000 g / mol or more, and further may have a weight average molecular weight of 50,000 g / mol or less, 45,000 g / mol or less, 40,000 g / mol or less, 35,000 g / mol or less, 30,000 g / mol or less, 25,000 g / mol or less, or 20,000 g / mol or less, and within this range, the function as a chemical stone compatibilizer may be more excellent without impairing the inherent properties of a heterogeneous biodegradable resin, particularly a polyester resin.

[0074] According to one embodiment of the present invention, the acrylic copolymer may have an epoxy number per molecule (Efn) based on the number average molecular weight of 30 or more and 80 or less. As a specific example, the acrylic copolymer may have an epoxy number per molecule (Efn) based on a number average molecular weight of 30 or more, 31 or more, 32 or more, 33 or more, 34 or more, 35 or more, 36 or more, 37 or more, 38 or more, 39 or more, 40 or more, 41 or more, 42 or more, 43 or more, 44 or more, or 45 or more, and may also have an epoxy number of 80 or less, 79 or less, 78 or less, 77 or less, 76 or less, 75 or less, 74 or less, 73 or less, 72 or less, 71 or less, or 70 or less, and when the acrylic copolymer is applied as a chemical compatibilizer to a resin composition containing a heterogeneous biodegradable resin within this range, a dramatic increase in viscosity is suppressed as much as possible, so that the amount of the acrylic copolymer used can be freely adjusted within a relatively wide range, and thus, it may be particularly useful in the development of resin compositions for various purposes. The above number of epoxy molecules per molecule (Efn) based on the average molecular weight may be calculated using the following equation 2, and the decimal part may be expressed by rounding it down.

[0075] [Formula 2]

[0076] Efn = DP / Molar ratio of (meth)acrylate monomer units containing epoxy groups

[0077] In the above formula 2, the molar ratio of the (meth)acrylate monomer unit containing an epoxy group is the same value as the molar ratio of the (meth)acrylate monomer unit containing an epoxy group defined in the DP calculation in formula 1 below.

[0078] The above DP can be calculated by measuring the molar ratio of each monomer unit according to nuclear magnetic resonance spectroscopy using a 700 MHz NMR spectrometer from Bruker for an acrylic copolymer, and then calculating the degree of polymerization (DP) of the total monomer unit (repeating unit) according to Equation 1 below using the number average molecular weight (Mn) value of the acrylic copolymer.

[0079] [Formula 1]

[0080] Mn(g / mol) = DP{(molecular weight of the first monomer (g / mol) * molar ratio of the first monomer) + 쪋 + (molecular weight of the nth monomer (g / mol) * molar ratio of the nth monomer)}

[0081] In the above formula 1, the value of "molecular weight * molar ratio" for the first to nth monomers in {} is determined according to the number n of monomers included in the acrylic copolymer, and when the acrylic copolymer is a binary copolymer, the nth monomer means the second monomer, when it is a ternary copolymer, the nth monomer means the third monomer, and when it is a quaternary copolymer, the nth monomer means the fourth monomer. The molar ratio of each monomer is a relative value based on the molar ratio of any one monomer among the first to nth monomers. At this time, the part following the decimal point can be expressed by rounding.

[0082] According to one embodiment of the present invention, the acrylic copolymer may have a weight average molecular weight of 5,000 g / mol or more and 100,000 g / mol or less. As a specific example, the acrylic copolymer may have a weight average molecular weight of 5,000 g / mol or more, 10,000 g / mol or more, 15,000 g / mol or more, or 20,000 g / mol or more, and may also have a weight average molecular weight of 100,000 g / mol or less, 90,000 g / mol or less, 80,000 g / mol or less, 70,000 g / mol or less, 60,000 g / mol or less, 50,000 g / mol or less, or 40,000 g / mol or less, and within this range, the mechanical properties of the resin composition can be further improved without impairing the inherent properties of a heterogeneous biodegradable resin, particularly a polyester resin.

[0083] According to one embodiment of the present invention, the acrylic copolymer may have an epoxy number per molecule (Efw) based on a weight average molecular weight of 20 or more and 170 or less. As a specific example, the acrylic copolymer may have an epoxy number per molecule (Efw) based on a weight average molecular weight of 20 or more, 25 or more, 30 or more, 35 or more, 40 or more, 45 or more, 50 or more, 55 or more, 60 or more, 65 or more, 70 or more, 75 or more, or 80 or more, and further, 170 or less, 169 or less, 168 or less, 167 or less, 166 or less, 165 or less, 164 or less, 163 or less, 162 or less, 161 or less, 160 or less, 159 or less, 158 or less, 157 or less, 156 or less, 155 or less, 154 or less, 153 or less, 152 or less, 151 or less, 150 or less, 149 or less, 148 or less, 147 or less, 146 Below, it can be 145 or less, 144 or less, 143 or less, 142 or less, 141 or less, or 140 or less, and when the acrylic copolymer is applied as a chemical compatibilizer to a resin composition containing a heterogeneous biodegradable resin within this range, a dramatic increase in viscosity can be suppressed as much as possible, thereby further preventing a decrease in processability. The epoxy number per molecule (Efw) based on the weight average molecular weight can be calculated through the following equation 4, and the part after the decimal point can be expressed by rounding off.

[0084] [Formula 4]

[0085] Efw = Mw (g / mol) / EEW (g / eq)

[0086] In the above formula 4, Mw is the weight average molecular weight of the acrylic copolymer, and EEW means the epoxy equivalent.

[0087] According to one embodiment of the present invention, the acrylic copolymer may have a glass transition temperature of 45° C. or higher and 85° C. or lower. As a specific example, the acrylic copolymer may have a glass transition temperature of 45° C. or higher, 46° C. or higher, 47° C. or higher, 48° C. or higher, 49° C. or higher, or 50° C. or higher, and may also have a glass transition temperature of 85° C. or lower, 84° C. or lower, 83° C. or lower, 82° C. or lower, 81° C. or lower, or 80° C. Within this range, processing as a compatibilizer for a resin composition including a different type of biodegradable resin may be easier.

[0088]

[0089] The present invention provides a resin composition.

[0090] The above resin composition may be a biodegradable resin composition comprising different types of biodegradable resins. As a specific example, the resin composition may comprise at least one of a first biodegradable resin and a second biodegradable resin, an acrylic copolymer, and a compatibilizer formed from the acrylic copolymer, wherein the acrylic copolymer may be the acrylic copolymer described above.

[0091] The first biodegradable resin and the second biodegradable resin are different types of biodegradable resins, and any resin known as a biodegradable resin can be used. However, as a specific example, the first biodegradable resin may be a polyester-based resin including an aliphatic polyester unit and an aromatic polyester unit. As a more specific example, the first biodegradable resin may include polybutylene adipate terephthalate (PBAT). PBAT is a random copolymer of adipic acid, 1,4-butanediol, and terephthalic acid, and is proposed as an alternative to low-density polyethylene as a biodegradable resin. In particular, the PBAT can secure biodegradability from the aliphatic polyester unit formed by adipic acid and 1,4-butanediol, while securing mechanical properties from the aromatic polyester unit formed by terephthalic acid and 1,4-butanediol.

[0092] The second biodegradable resin may be any biodegradable resin different from the first biodegradable resin. However, as a specific example, the second biodegradable resin may include polylactic acid (PLA). PLA is an environmentally friendly biodegradable resin produced from bio-based raw materials and naturally decomposes into water and carbon dioxide within several months through the action of microorganisms.

[0093] The resin composition may contain the second biodegradable resin in an amount of 1 part by weight or more and 1,000 parts by weight or less, based on 100 parts by weight of the first biodegradable resin. As a specific example, the resin composition may contain the second biodegradable resin in an amount of 1 part by weight or more, 10 parts by weight or more, 20 parts by weight or more, 30 parts by weight or more, 40 parts by weight or more, or 50 parts by weight or more, based on 100 parts by weight of the first biodegradable resin, and may also contain the second biodegradable resin in an amount of 1,000 parts by weight or less, 900 parts by weight or less, 800 parts by weight or less, 700 parts by weight or less, 600 parts by weight or less, 500 parts by weight or less, 400 parts by weight or less, 300 parts by weight or less, 200 parts by weight or less, or 150 parts by weight or less, based on 100 parts by weight of the first biodegradable resin. Within this range, the mechanical properties and processability may be further improved.

[0094] The resin composition may contain at least one of the acrylic copolymer and the compatibilized portion formed from the acrylic copolymer in an amount of 0.01 parts by weight or more and 10 parts by weight or less, based on 100 parts by weight of the first biodegradable resin. As a specific example, the resin composition may include at least one of the acrylic copolymer and the compatibilized part formed from the acrylic copolymer in an amount of 0.01 part by weight or more, 0.05 part by weight or more, 0.10 part by weight or more, 0.20 part by weight or more, 0.30 part by weight or more, 0.40 part by weight or more, 0.50 part by weight or more, 0.60 part by weight or more, 0.70 part by weight or more, 0.80 part by weight or more, 0.90 part by weight or more, or 1.00 part by weight or more, based on 100 parts by weight of the first biodegradable resin, and further, in an amount of 10.00 parts by weight or less, 9.00 parts by weight or less, 8.00 parts by weight or less, 7.00 parts by weight or less, 6.00 parts by weight or less, 5.00 parts by weight or less, 4.00 parts by weight or less, 3.00 parts by weight or less, or 2.00 parts by weight or less. It may include.

[0095] According to one embodiment of the present invention, the acrylic copolymer is a copolymer containing a reactive functional group such as an epoxy group, and may be included as a chemical compatibilizer to improve the compatibility of a different type of biodegradable resin in the resin composition. The acrylic copolymer may exist as such in the resin composition, or may exist in the form of a compatibilizing portion through a chemical bond formed by a reaction of the reactive functional group with the different type of biodegradable resin, or both forms may coexist.

[0096] According to one embodiment of the present invention, the resin composition may have a weight average molecular weight of the entire resin composition of 100,000 g / mol or more and 200,000 g / mol or less. As a specific example, the resin composition may have a weight average molecular weight of the entire resin composition of 100,000 g / mol or more, 105,000 g / mol or more, 110,000 g / mol or more, 115,000 g / mol or more, 120,000 g / mol or more, 125,000 g / mol or more, or 130,000 g / mol or more, and further, 200,000 g / mol or less, 195,000 g / mol or less, 190,000 g / mol or less, 185,000 g / mol or less, 180,000 g / mol or less, 175,000 g / mol or less, 170,000 g / mol or less, 165,000 g / mol or less, 160,000 g / mol or less, or 155,000 g / mol. It may be as follows, and the tensile properties of the resin composition can be further improved within this range.

[0097] According to one embodiment of the present invention, the resin composition may have a melt index of 1.5 g / 10 min or more and 14.0 g / 10 min or less, measured at 190°C under a load of 5 kg according to ASTM D1238. As a specific example, the resin composition may have a melt index measured at 190° C. under a load of 5 kg according to ASTM D1238 of 1.5 g / 10 min or more, 2.0 g / 10 min or more, 3.0 g / 10 min or more, 3.5 g / 10 min or more, 3.5 g / 10 min or more, 4.0 g / 10 min or more, 4.5 g / 10 min or more, 5.0 g / 10 min or more, 5.5 g / 10 min or more, or 6.0 g / 10 min or more, and may also have a melt index of 14.0 g / 10 min or less, 13.5 g / 10 min or less, 13.0 g / 10 min or less, 12.5 g / 10 min or less, or 12.0 g / 10 min or less, and within this range, the tensile strength of the resin composition is excellent while maintaining the viscosity at an appropriate level, thereby further improving processability.

[0098] According to one embodiment of the present invention, the resin composition has a tensile strength of 200 kgf / cm as measured according to ASTM D638. 2 Above, 500 kgf / cm 2 It may be as follows. As a specific example, the resin composition has a tensile strength of 200 kgf / cm as measured according to ASTM D638. 2 Above, 210 kgf / cm 2 Above, 220 kgf / cm 2 Above, 230 kgf / cm 2 Above, 240 kgf / cm 2 Above, 250 kgf / cm 2 Above, 260 kgf / cm 2 Above, 270 kgf / cm 2 Above, 280 kgf / cm 2 Above, 290 kgf / cm 2or more than 300 kgf / cm 2 It may be more than 500 kgf / cm 2 Below, 490 kgf / cm 2 Below, 480 kgf / cm 2 Below, 470 kgf / cm 2 Below, 460 kgf / cm 2 Below 450 kgf / cm 2 Below, 440 kgf / cm 2 Below, 430 kgf / cm 2 or less, or 420 kgf / cm 2 It could be as follows:

[0099] According to one embodiment of the present invention, the resin composition may have an elongation of 150% or more as measured according to ASTM D638. As a specific example, the resin composition may have an elongation measured according to ASTM D638 of 150% or more, 160% or more, 170% or more, 180% or more, 190% or more, 200% or more, 210% or more, 220% or more, 230% or more, 240% or more, 250% or more, 260% or more, 270% or more, 280% or more, 290% or more, 300% or more, or 310% or more, and further, 700% or less, 690% or less, 680% or less, 670% or less, 660% or less, 650% or less, 640% or less, 630% or less, 620% or less, 610% or less, 600% or less, 590% or less, 580% or less, 570% or less, It may be 560% or less, 550% or less, 540% or less, 530% or less, 520% ​​or less, 510% or less, 500% or less, 490% or less, 480% or less, 470% or less, 460% or less, 450% or less, 440% or less, 430% or less, 420% or less, 410% or less, or 400% or less.

[0100]

[0101] The present invention provides a molded product.

[0102] The above molded article may be a biodegradable molded article molded from the above resin composition, i.e., a biodegradable resin composition. Here, the molded article includes both an injection molded article formed through injection molding or the like as well as a film molded article formed through film formation.

[0103] The above-mentioned molded product may be a biodegradable film, and a specific example thereof may be a film for use as an agricultural mulching film or a food packaging material.

[0104]

[0105] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0106]

[0107] Examples and Comparative Examples: Preparation of Acrylic Copolymer

[0108] Example 1

[0109] In a 3 L glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, 100 parts by weight of monomers such as methyl methacrylate, glycidyl methacrylate, and butyl acrylate, 200 parts by weight of distilled water, and 0.5 parts by weight of sodium dioctyl sulfosuccinate (sodium bis(2-ethylhexyl) sulfosuccinate) as an emulsifier were added and stirred. During stirring, the inside of the reactor was replaced with nitrogen gas, and then the glass reactor was heated to 70°C, 0.2 parts by weight of potassium persulfate was added, and stirred for 10 minutes.

[0110] Separately, 50 parts by weight of methyl methacrylate, 30 parts by weight of glycidyl methacrylate, and 20 parts by weight of butyl acrylate as monomers were added to a beaker and thoroughly mixed for 30 minutes. 0.7 parts by weight of 1-octanethiol as a chain transfer agent was added here based on 100 parts by weight of the total monomers, and after sufficient mixing with a stirrer, this mixture was continuously and evenly added to the glass reactor for 4 hours.

[0111] After this, after 4 hours of polymerization reaction time, the temperature inside the glass reactor was maintained at 70°C for 30 minutes while stirring, and then cooled to room temperature. The obtained emulsion polymerization product was coagulated using a calcium acetate aqueous solution, heat-treated at an elevated temperature of 90°C, dehydrated, and dried at 60°C for 16 hours to produce an acrylic copolymer.

[0112]

[0113] Example 2

[0114] An acrylic copolymer was obtained in the same manner as in Example 1, except that methyl methacrylate was added in an amount of 45 parts by weight instead of 50 parts by weight, glycidyl methacrylate was added in an amount of 40 parts by weight instead of 30 parts by weight, butyl acrylate was added in an amount of 15 parts by weight instead of 20 parts by weight, and 1-octanethiol was added in an amount of 1.0 parts by weight instead of 0.7 parts by weight.

[0115]

[0116] Example 3

[0117] An acrylic copolymer was obtained in the same manner as in Example 1, except that methyl methacrylate was added in an amount of 35 parts by weight instead of 50 parts by weight, glycidyl methacrylate was added in an amount of 50 parts by weight instead of 30 parts by weight, butyl acrylate was added in an amount of 15 parts by weight instead of 20 parts by weight, and 1-octanethiol was added in an amount of 1.4 parts by weight instead of 0.7 parts by weight.

[0118]

[0119] Example 4

[0120] An acrylic copolymer was obtained by performing the same method as in Example 1, except that methyl methacrylate was added in an amount of 35 parts by weight instead of 50 parts by weight, glycidyl methacrylate was added in an amount of 50 parts by weight instead of 30 parts by weight, and butyl acrylate was added in an amount of 15 parts by weight instead of 20 parts by weight.

[0121]

[0122] Comparative Example 1

[0123] No acrylic copolymer was produced.

[0124]

[0125] Comparative Example 2

[0126] An acrylic copolymer was obtained by performing the same method as in Example 1, except that 75 parts by weight of methyl methacrylate was added instead of 50 parts by weight, and 5 parts by weight of glycidyl methacrylate was added instead of 30 parts by weight.

[0127]

[0128] Comparative Example 3

[0129] An acrylic copolymer was obtained by performing the same method as in Example 1, except that methyl methacrylate was added in an amount of 70 parts by weight instead of 50 parts by weight and glycidyl methacrylate was added in an amount of 10 parts by weight instead of 30 parts by weight.

[0130]

[0131] Comparative Example 4

[0132] An acrylic copolymer was obtained by performing the same method as in Example 1, except that methyl methacrylate was added in an amount of 60 parts by weight instead of 50 parts by weight, glycidyl methacrylate was added in an amount of 20 parts by weight instead of 30 parts by weight, and 1-octanethiol was added in an amount of 1.4 parts by weight instead of 0.7 parts by weight.

[0133]

[0134] Comparative Example 5

[0135] An acrylic copolymer was obtained by performing the same method as in Example 1, except that methyl methacrylate was added in an amount of 60 parts by weight instead of 50 parts by weight and glycidyl methacrylate was added in an amount of 20 parts by weight instead of 30 parts by weight.

[0136]

[0137] Comparative Example 6

[0138] An acrylic copolymer was obtained by performing the same method as in Example 1, except that methyl methacrylate was added in an amount of 15 parts by weight instead of 50 parts by weight, glycidyl methacrylate was added in an amount of 70 parts by weight instead of 30 parts by weight, and butyl acrylate was added in an amount of 15 parts by weight instead of 20 parts by weight.

[0139]

[0140] Experimental example

[0141] Experimental Example 1: Characterization of Acrylic Copolymers

[0142] For the acrylic copolymers manufactured in Examples 1 to 4 and Comparative Examples 2 to 6, the number average molecular weight and the weight average molecular weight were measured by the following methods, and the number of epoxy units (Efn) per number average molecular weight calculated according to Equation 2, the epoxy equivalent calculated according to Equation 3, and the number of epoxy units (Efw) per weight average molecular weight calculated according to Equation 4 were shown in Table 1 below.

[0143]

[0144] * Weight average molecular weight (Mw) and number average molecular weight (Mn): The weight average molecular weight and number average molecular weight of the obtained acrylic copolymer sample were measured using gel permeation chromatography (GPC: gel permeation chromatography, PL GPC220, Agilent Technologies) under the following conditions. At this time, the sample was used as a part of a solution dissolved in the solvent Tetrahydrofuran (Stabilized with BHT) at a concentration of 2 mg / ml.

[0145] - Column: PL MiniMixed BX 2

[0146] - Solvent: Tetrahydrofuran (Stabilized with BHT)

[0147] - Flow rate: 0.3 ml / min

[0148] - Sample concentration: 2.0 mg / ml

[0149] - Column temperature: 40 ℃

[0150] - Detector: Waters 2414 Refractive Index Detector

[0151] - Data processing: Empower

[0152] - Black curve: Polystyrene standards (9 types with molecular weights of 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000) used

[0153]

[0154] * Number of epoxy units per molecule based on number-average molecular weight (Efn): For each acrylic copolymer of the examples and comparative examples, the molar ratio of each monomer unit was measured by nuclear magnetic resonance spectroscopy using a 700 MHz NMR spectrometer from Bruker. Then, using the number-average molecular weight (Mn) value measured according to the above measurement method, the degree of polymerization (DP) of the total monomer unit (repeating unit) was calculated according to Equation 1-1 below.

[0155] [Formula 1-1]

[0156] Mn(g / mol) = DP{(Methyl methacrylate molecular weight(g / mol) * Molar ratio of methyl methacrylate monomer units) + (Glycidyl methacrylate molecular weight(g / mol) * Molar ratio of glycidyl methacrylate monomer units) + (Butyl acrylate molecular weight(g / mol) * Molar ratio of butyl acrylate monomer units)}

[0157] In the above formula 1-1, the molar ratio of each monomer is a relative value based on the molar ratio of glycidyl methacrylate.

[0158] For each acrylic copolymer of the examples and comparative examples, the degree of polymerization for the total monomer unit calculated according to Equation 1 above based on the molar ratio of glycidyl methacrylate (based on a GMA molar ratio of 1) is shown in Table 1 below. In this case, the part after the decimal point was rounded off.

[0159] Next, using the following Equation 2-1, the number of epoxy molecules per molecule based on the number average molecular weight was calculated. At this time, the part after the decimal point was rounded.

[0160] [Formula 2-1]

[0161] Efn = DP / Molar ratio of glycidyl methacrylate monomer units

[0162] In the above formula 2-1, the molar ratio of the glycidyl methacrylate monomer unit is the same value as the molar ratio of the glycidyl methacrylate monomer unit defined when calculating DP in the above formula 1-1.

[0163]

[0164] * Epoxy equivalent (EEW, g / eq (=g / mol)): For each acrylic copolymer of the examples and comparative examples, the epoxy equivalent was calculated using Equation 3 below based on the number average molecular weight (Mn) value measured according to the above measurement method and the number of epoxy groups per molecule (Efn) calculated according to the number average molecular weight according to the above measurement method. At this time, the part after the decimal point was rounded. Here, the epoxy equivalent means the equivalent of an epoxy group in a polymer and / or copolymer containing an epoxy group, and is expressed as the number of grams of epoxy groups contained in 1 mol of polymer and / or copolymer, and is expressed in g / mol or g / eq. The present invention is expressed by expressing the unit of epoxy equivalent as g / eq, which is equivalent to g / mol, according to a conventional method.

[0165] [Formula 3]

[0166] EEW(g / eq) = Mn (g / mol) / Efn

[0167]

[0168] * Number of epoxy molecules per molecule based on weight-average molecular weight (Efw): For each acrylic copolymer of the examples and comparative examples, the number of epoxy molecules per molecule based on weight-average molecular weight was calculated using Equation 4 below based on the measured weight-average molecular weight (Mw) and epoxy equivalent weight (EEW). In this case, the decimal part was rounded off.

[0169] [Formula 4]

[0170] Efw = Mw (g / mol) / EEW (g / eq)

[0171]

[0172] Distinctive monomer unit molar ratio DPMnMwE.E.WEfnEfwMMA1) GMA 2) BA 3) (g / mol)(g / mol)(g / eq)Example 12.351.000.754220,00040,0004734285Example 21.631.000.425620,00030,0003595684Example 31.001.000.343510,00020,0002863570Example 41.001.000.347020,00040,00028670140Comparative Example 1---------Comparative Example 222.001.004.50720,00040,0002,918714Comparative Example 310.001.002.201420,00040,0001,4241428Comparative example 44.301.001.101410,00020,0007131428Comparative example 54.301.001.102820,00040,0007132856Comparative example 61.009920,00040,000203991971) MMA: Methyl methacrylate2) GMA: Glycidyl methacrylate3) BA: Butyl acrylate

[0173] As shown in Table 1 above, it was confirmed that the acrylic copolymers manufactured in Examples 1 to 4 had epoxy equivalents, weight-average molecular weights, and epoxy number per molecule (Efw) based on weight-average molecular weights controlled within the ranges defined in the present invention.

[0174] On the other hand, it was confirmed that the acrylic copolymer manufactured in Comparative Example 2 had a very high epoxy equivalent, which was outside the range limited by the present invention, and accordingly, the number of epoxy molecules per molecule (Efw) based on the weight average molecular weight was very low.

[0175] In addition, it was confirmed that the acrylic copolymer manufactured in Comparative Example 3 had an epoxy number per molecule (Efw) based on the weight average molecular weight that was controlled within the range limited by the present invention, but the epoxy equivalent was very high, exceeding the range limited by the present invention.

[0176] In addition, it was confirmed that the acrylic copolymer manufactured in Comparative Example 4 had a very low epoxy equivalent, and accordingly, the number of epoxy molecules per molecule (Efw) based on the weight average molecular weight was very high.

[0177]

[0178] Experimental Example 2: Preparation of Resin Composition

[0179] Polybutylene adipate terephthalate (manufacturer: Xinjiang Blueridge Tunhe Chemical Industry Co., Ltd., product name: TH801T) and polylactic acid (manufacturer: Natureworks Co., Ltd., product name: Ingeo Biopolymer 2003D) were each dried in an oven at 60°C for 24 hours.

[0180] Next, 50 parts by weight of polybutylene adipate terephthalate, 50 parts by weight of polylactic acid, and 1 part by weight of the acrylic copolymer prepared in the above examples and comparative examples were mixed, and blended at 170°C and 60 rpm for 10 minutes using a Haake Rheomix OS Lab mixer from Thermo Electron Karlsruhe GmbH. Subsequently, the mixture was pulverized to prepare resin compositions for each of the examples and comparative examples.

[0181] At this time, the resin composition according to Comparative Example 1 was manufactured without adding an acrylic copolymer.

[0182]

[0183] Experimental Example 3: Evaluation of Resin Compositions

[0184] For the resin compositions of each example and comparative example manufactured in the above experimental example 2, the melting index, tensile strength, elongation, and melting index were measured using the following method and are shown in Table 2 below.

[0185]

[0186] * Melting index (g / 10 min): The melting index of the manufactured resin composition sample was measured according to ISO 1133 (190 ℃, 5 kg) using Gottfert MI-4.

[0187]

[0188] * Tensile strength and elongation: Each of the manufactured resin compositions was placed in a mold measuring 125 mm X 125 mm X 2 mm, preheated at 180 ℃ for about 5 minutes, pressed for 3 minutes under a compressive load of 10 MPa, and then quenched at room temperature to prepare a specimen. The manufactured specimens were prepared as test specimens according to the ASTM D638, Type 4 standard, and the elongation and tensile strength were measured according to the ASTM D638 standard at 50 mm / min using a universal testing machine (Instron 3365) from Instron.

[0189]

[0190] Melting index tensile strength elongation (g / 10 min) (kgf / cm) 2 )(%)Example 18.0300310Example 26.0390390Example 33.5420390Example 45.0410400Comparative Example 115.316840Comparative Example 215.016030Comparative Example 313.818080Comparative Example 410.0260280Comparative Example 512.0260270Comparative Example 61.0380100

[0191] As shown in Table 2 above, it was confirmed that the resin compositions in which the acrylic copolymers of Examples 1 to 4 of the present invention were applied as compatibilizers prevented a rapid decrease in melt index compared to the resin composition prepared in Comparative Example 1 that did not include a compatibilizer, while the tensile strength and elongation were significantly improved.

[0192] On the other hand, it was confirmed that the resin compositions in which the acrylic copolymers of Comparative Examples 2 and 3 were applied as a compatibilizer maintained the melt index, tensile strength, and elongation at the same level as the resin composition prepared in Comparative Example 1 that did not include a compatibilizer.

[0193] In addition, it was confirmed that the resin compositions in which the acrylic copolymers of Comparative Examples 4 and 5 were applied as compatibilizers had somewhat improved tensile strength and elongation compared to the resin composition prepared in Comparative Example 1 that did not include a compatibilizer, but that the improvement in tensile strength and elongation was minimal compared to the resin compositions in which the acrylic copolymers of Examples 1 to 4 were applied as compatibilizers.

[0194] In addition, it was confirmed that the melt index of the resin composition in which the acrylic copolymer of Comparative Example 6 was applied as a compatibilizer was drastically reduced compared to the resin composition prepared in Comparative Example 1 that did not include a compatibilizer, and thus the processability was significantly reduced. It was also confirmed that there was almost no improvement in elongation compared to the resin composition in which the acrylic copolymer of Examples 1 to 4 was applied as a compatibilizer.

[0195]

[0196] From these results, it was confirmed that the acrylic copolymer of the present invention functions as a chemical compatibilizer for improving compatibility between different types of biodegradable resins, thereby improving the mechanical properties of the resin composition through improving compatibility between different types of biodegradable resins, and preventing a decrease in the processability of the resin composition by suppressing a dramatic increase in viscosity during processing of the resin composition.

Claims

1. Containing an alkyl (meth)acrylate monomer unit and a (meth)acrylate monomer unit containing an epoxy group, The epoxy equivalent weight (EEW) is 100 g / eq or more and 1,000 g / eq or less, The number of epoxy molecules (Efn) per molecule based on the average molecular weight is 30 or more and 80 or less, An acrylic copolymer having an epoxy number per molecule (Efw) based on the weight average molecular weight of 20 or more and 170 or less.

2. In paragraph 1, The above acrylic copolymer is an acrylic copolymer having an epoxy equivalent weight (EEW) of 250 g / eq or more and 750 g / eq or less.

3. In paragraph 1, The above acrylic copolymer is an acrylic copolymer having a number average molecular weight of 5,000 g / mol or more and 50,000 g / mol or less.

4. In paragraph 1, The above acrylic copolymer is an acrylic copolymer having a number average molecular weight of 10,000 g / mol or more and 20,000 g / mol or less.

5. In paragraph 1, The above acrylic copolymer is an acrylic copolymer having a weight average molecular weight of 5,000 g / mol or more and 100,000 g / mol or less.

6. In paragraph 1, The above acrylic copolymer is an acrylic copolymer having a weight average molecular weight of 15,000 g / mol or more and 40,000 g / mol or less.

7. In paragraph 1, The above acrylic copolymer is an acrylic copolymer having an epoxy number per molecule (Efn) based on the number average molecular weight of 35 or more and 70 or less.

8. In paragraph 1, The above acrylic copolymer is an acrylic copolymer having an epoxy number per molecule (Efw) based on the weight average molecular weight of 70 or more and 140 or less.

9. In paragraph 1, The above acrylic copolymer is, 40 wt% or more and 75 wt% or less of alkyl (meth)acrylate monomer units, and An acrylic copolymer comprising 25 wt% or more and 60 wt% or less of a (meth)acrylate monomer unit containing an epoxy group.

10. In paragraph 1, An acrylic copolymer wherein the above alkyl (meth)acrylate monomer unit includes a methyl (meth)acrylate monomer unit and an alkyl (meth)acrylate monomer unit having 2 to 10 carbon atoms.

11. In paragraph 1, The above acrylic copolymer is, 10 wt% or more and 65 wt% or less of methyl (meth)acrylate monomer unit, 25 wt% or more and 60 wt% or less of a (meth)acrylate monomer unit containing an epoxy group, and An acrylic copolymer comprising 5 to 60 wt% of an alkyl (meth)acrylate monomer unit having 2 to 10 carbon atoms.

12. In paragraph 1, The above acrylic copolymer is an acrylic copolymer comprising a methyl methacrylate monomer unit, a glycidyl methacrylate monomer unit, and an alkyl (meth)acrylate monomer unit having 4 to 8 carbon atoms.

13. Comprising at least one of a first biodegradable resin and a second biodegradable resin, an acrylic copolymer, and a commercially available portion formed from the acrylic copolymer; A resin composition wherein the acrylic copolymer is an acrylic copolymer according to any one of claims 1 to 12.

14. A molded product molded from a resin composition according to Article 13.