KR20220128024A - Copolymer composition, method for preparing the copolymer composition and resin composition comprising the copolymer composition - Google Patents

Abstract

The present invention relates to a copolymer composition and, more particularly, to a copolymer composition, a manufacturing method thereof, and a resin composition comprising the same, wherein the copolymer composition comprises: 90 to 99 wt% of a graft copolymer; and 1 to 10 wt% of an acrylic copolymer. The graft copolymer comprises: 80 to 95 wt% of a rubbery polymer containing an alkyl (meth)acrylate monomer unit with 2 to 18 carbon atoms; and 5 to 20 wt% of an alkyl (meth)acrylate monomer unit with 1 to 18 carbon atoms. The acrylic copolymer comprises: 75 to 95 wt% of a methyl (meth)acrylate monomer unit; and 5 to 25 wt% of an alkyl (meth)acrylate monomer unit with 2 to 18 carbon atoms. The acrylic copolymer has a weight average molecular weight of 8,000,000 to 12,000,000 g/mol. The shock resistance of the resin composition can be enhanced.

Description

A copolymer composition, a method for producing the same, and a resin composition comprising the same

The present invention relates to a copolymer composition, and more particularly, to a copolymer composition excellent in processability and impact strength as an impact modifier for polylactic acid resin, a method for preparing the same, and a resin composition comprising the same.

Although plastic materials (PP, ABS, etc.) made from fossil resources such as petroleum and coal have excellent physical properties, they emit carbon dioxide when disposed of, causing global warming due to an increase in carbon dioxide in the atmosphere. Therefore, from the viewpoint of preventing global warming, the necessity of reducing the amount of such petrochemical materials used and developing an eco-friendly material that can replace them has emerged and is being studied.

On the other hand, plant-derived resin produced by photosynthesis using carbon dioxide and water as raw materials is incinerated to generate carbon dioxide, but the generated carbon dioxide corresponds to carbon dioxide originally present in the atmosphere, and consequently increases the amount of carbon dioxide in the atmosphere. don't make it In the case of using a carbon neutral material as described above, its importance is being emphasized from the viewpoint of preventing global warming by not increasing the total amount of carbon dioxide in the atmosphere.

A representative example of such a plant-derived resin is polylactic acid (PLA). The polylactic acid resin is obtained from corn or sugar cane and finally biodegradable into water and carbon dioxide (carbon neutral). However, since excellent mechanical properties and melt molding are possible, it is used for various purposes in various fields.

The polylactic acid resin has recently been attracting attention because it can be used for parts of automobiles or electronic products. In addition, there is a great advantage in terms of stable supply because the raw material is a permanently renewable plant rather than a petroleum resource that is expected to be depleted due to limited reserves. In this regard, "biodegradable resin" is known as a resin that can be decomposed by the action of naturally occurring microorganisms such as bacteria.

However, polylactic acid resin alone exhibits relatively hard and brittle properties compared to other general-purpose polymer materials, and has low heat resistance, so it is often difficult to use in members requiring high impact resistance and heat resistance, and adhesion (mold releasability) This is not good, so there is a disadvantage that productivity is lowered during molding. Therefore, in order to easily apply the polylactic acid resin, a method capable of overcoming the above-described disadvantages is required, and a method for blending a polycarbonate resin or other heterogeneous polymer with the polylactic acid resin is known.

For example, Japanese Patent Publication No. 3279768 discloses a resin composition made of aromatic polycarbonate/polylactic acid alloy, having pearl luster and excellent impact resistance and heat resistance, but the content of polylactic acid-based resin is limited to reduce carbon dioxide The disadvantage is that it is not very effective.

Accordingly, in order to improve the impact resistance of the polylactic acid resin, a method of applying a core-shell type impact modifier has been proposed. In order to improve the impact resistance by the impact modifier, it is necessary to use a high content of rubber. However, as the rubber content in the impact modifier increases, the shell (graft layer) inevitably decreases relatively, and accordingly, there is a problem in that the dispersibility and powder properties of the impact modifier are deteriorated.

JP3279768B2

The present invention has been devised to solve the problems of the prior art, and while minimizing a decrease in transparency of a polylactic acid resin having a low refractive index, and improving the impact resistance of the resin composition with a high rubber content, dispersibility and powder properties At the same time, an object of the present invention is to provide a copolymer composition as an improved acrylic impact modifier.

In addition, an object of the present invention is to provide a resin composition comprising the copolymer composition as an impact modifier, which has excellent impact resistance without deterioration of transparency, and excellent tensile strength and elongation.

In order to solve the above problems, the present invention comprises 90 wt% to 99 wt% of a graft copolymer and 1 wt% to 10 wt% of an acrylic copolymer, and the graft copolymer is an alkyl (meth) having 2 to 18 carbon atoms. ) 80 wt% to 95 wt% of a rubbery polymer comprising an acrylate monomer unit and 5 wt% to 20 wt% of an alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms, wherein the acrylic copolymer is methyl (meth) ) 75 wt% to 95 wt% of an acrylate monomer unit and 5 wt% to 25 wt% of an alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms, and having a weight average molecular weight of 8,000,000 g/mol to 12,000,000 g/mol It provides a copolymer composition that is

In addition, the present invention provides 80 wt% to 95 wt% of a rubbery polymer comprising an alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms and 5 wt% to 20 wt% of an alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms. % to prepare a graft copolymer containing (S10); 75 wt% to 95 wt% of methyl (meth)acrylate monomer units and 5 wt% to 25 wt% of alkyl (meth)acrylate monomer units having 2 to 18 carbon atoms, and having a weight average molecular weight of 8,000,000 g/mol to 12,000,000 g/mol preparing an acrylic copolymer (S20); and mixing 90 wt% to 99 wt% of the graft copolymer and 1 wt% to 10 wt% of the acrylic copolymer (S30).

In addition, the present invention provides a resin composition comprising a copolymer composition and a polylactic acid resin.

When the copolymer composition of the present invention is applied as an impact modifier to the polylactic acid resin, while minimizing the decrease in transparency of the low refractive index polylactic acid resin, the high rubber content improves the impact resistance of the resin composition, and at the same time, dispersibility and powder properties are simultaneously improved.

In addition, the resin composition of the present invention includes the copolymer composition as an impact modifier, thereby having excellent impact resistance without deterioration in transparency, and excellent tensile strength and elongation.

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

The terms or words used in the description and claims of the present invention should not be construed as being limited to their ordinary or dictionary meanings, and the inventor must properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

In the present invention, the term 'monomer unit' may refer to a component, structure, or material itself derived from a monomer. it could mean

As used herein, the term 'composition' includes reaction products and decomposition products formed from materials of the composition, as well as mixtures of materials comprising the composition.

The present invention provides a copolymer composition. The copolymer composition may be an impact modifier for the polylactic acid resin, and a specific example may be an acrylic impact modifier. In this case, the decrease in transparency of the polylactic acid resin having a low refractive index compared to the butadiene-based impact modifier can be minimized.

According to an embodiment of the present invention, the copolymer composition comprises 90 wt% to 99 wt% of the graft copolymer and 1 wt% to 10 wt% of the acrylic copolymer, and the graft copolymer has 2 to 18 carbon atoms. 80 wt% to 95 wt% of a rubbery polymer comprising an alkyl (meth)acrylate monomer unit of and 5 wt% to 20 wt% of an alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms; contains 75 wt% to 95 wt% of a methyl (meth)acrylate monomer unit and 5 wt% to 25 wt% of an alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms, and has a weight average molecular weight of 8,000,000 g/mol to It may be 12,000,000 g/mol.

According to an embodiment of the present invention, the copolymer composition may be in a powder form. That is, the copolymer composition may be in a powder form including a graft copolymer and an acrylic copolymer, and it may be used as an impact modifier for the polylactic acid resin as described above. In this case, as described below, while increasing the content of the rubbery polymer corresponding to the core in the graft copolymer, it is possible to prevent deterioration of dispersibility and powder properties due to the reduction of the graft layer corresponding to the shell, impact strength can be obtained. On the other hand, unlike the present invention, when only the graft copolymer is used as the impact modifier for the polylactic acid resin, when the content of the rubber polymer is increased to improve the impact strength, the average particle size of the powder phase is reduced due to the reduced shell (graft layer). This increases, and there is a problem in that dispersibility and powder properties are deteriorated. In addition, when an acrylic copolymer having a high molecular weight, such as the acrylic copolymer, is included as an individual component in the resin composition instead of in the copolymer composition as in the present invention, during melt kneading for molding a molded article from the resin composition, graft Acting independently of the copolymer, it does not affect the dispersibility or powder properties of the graft copolymer having a high rubbery polymer content. Therefore, in order to improve the dispersibility and powder properties of the graft copolymer having a high rubbery polymer content, the acrylic copolymer should be included as the copolymer composition as in the present invention.

According to an embodiment of the present invention, the average particle diameter of the powder phase of the copolymer composition may be 100 μm to 300 μm, 150 μm to 250 μm, 150 μm to 200 μm, or 162 μm to 195 μm, and within this range By exhibiting an appropriate level of particle size, it is possible to prevent a decrease in dispersibility due to particles having a large particle size, and to prevent agglomeration between particles having a small particle size, thereby improving dispersibility.

According to one embodiment of the present invention, the copolymer composition is 90 wt% to 99 wt%, 93 wt% to 99 wt%, 95 wt% of the graft copolymer in order to secure the dispersibility and powder properties as described above. to 99 wt%, or 95 wt% to 98 wt% and 1 wt% to 10 wt%, 1 wt% to 7 wt%, 1 wt% to 5 wt%, or 2 wt% to 3 wt% acrylic copolymer It may include, and while maintaining the average particle diameter of the copolymer composition powder at an appropriate level within this range, there is an effect of simultaneously improving the tensile strength and the elongation as well as the impact strength of the resin composition.

According to an embodiment of the present invention, the graft copolymer is 80% to 95% by weight, 85% to 95% by weight of a rubbery polymer comprising an alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms, or It may include 87 wt% to 93 wt% and 5 wt% to 20 wt%, 5 wt% to 15 wt%, or 7 to 13 wt% of an alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms.

According to an embodiment of the present invention, the rubber polymer is a core part in the core-shell type graft copolymer, and the impact strength of the rubber polymer can be maximally improved. If the content of the rubber polymer in the graft copolymer is not sufficient, the improvement in impact strength may be insignificant, and if the content of the rubber polymer is too high, the average particle size of the powder phase is rapidly increased, which may cause a decrease in dispersibility, Accordingly, the impact strength may be rather reduced.

According to an embodiment of the present invention, the rubbery polymer may include an alkyl (meth) acrylate monomer unit having 2 to 18 carbon atoms, and an alkyl (meth) acryl forming the alkyl (meth) acrylate monomer unit. The rate monomer may be an alkyl (meth)acrylate having 2 to 18 carbon atoms, an alkyl (meth)acrylate having 2 to 12 carbon atoms, or an alkyl (meth)acrylate having 2 to 6 carbon atoms. Here, (meth)acrylate may mean acrylate or methacrylate. The alkyl (meth) acrylate monomer having 2 to 18 carbon atoms may be ethyl (meth) acrylate, propyl (meth) acrylate or butyl (meth) acrylate, for example, butyl acrylate.

According to an embodiment of the present invention, the alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms of the graft copolymer is a shell part in the core-shell type graft copolymer, and is compatible with the polylactic acid resin. It is possible to prevent deterioration of powder properties while securing In the graft copolymer, when the content of the alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms as the shell portion is not sufficient, the average particle size of the powder phase is rapidly increased to cause a decrease in dispersibility, and thus Accordingly, even if the rubber polymer is included in a high content, the impact strength may be rather reduced, and when the content of the alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms as the shell part is too high, the improvement in impact strength may be insignificant.

According to an embodiment of the present invention, the alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms of the graft copolymer may be formed by graft polymerization to the rubbery polymer, and may form a shell by itself. have. The alkyl (meth) acrylate monomer forming the alkyl (meth) acrylate monomer unit of the graft copolymer is an alkyl (meth) acrylate having 1 to 18 carbon atoms, an alkyl (meth) acrylate having 1 to 12 carbon atoms, or It may be an alkyl (meth)acrylate having 1 to 6 carbon atoms. Here, (meth)acrylate may mean acrylate or methacrylate. The alkyl (meth)acrylate monomer having 1 to 18 carbon atoms may be methyl (meth)acrylate, and a specific example may be methyl methacrylate.

According to an embodiment of the present invention, the rubbery polymer may include a crosslinkable monomer unit in addition to the alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms, and a graft determined from the crosslinkable monomer unit. The copolymer may have a swelling index of 3 to 10, 3 to 8, or 4 to 7, and the impact strength of the resin composition including the copolymer composition as an impact modifier within this range is excellent, and the effect of excellent mechanical properties there is

According to an embodiment of the present invention, the crosslinkable monomer unit is to further improve impact strength by crosslinking the rubbery polymer, and the crosslinkable monomer forming the crosslinkable monomer unit is divinylbenzene, 3-butanediol di Acrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, allyl acrylate, allyl methacrylate, trimethylolpropane triacrylate, tetraethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, triallyl isocyanurate, triarylamine and diallylamine It may be at least one selected from the group consisting of, and a specific example may be allyl methacrylate.

According to an embodiment of the present invention, when the rubbery polymer includes a crosslinkable monomer unit, the content of the crosslinkable monomer unit may be included within the content range of the entire rubbery polymer in the graft copolymer. It may be included in 0.1 wt% to 10.0 wt%, 0.1 wt% to 5.0 wt%, 0.1 wt% to 1.0 wt%, or 0.3 wt% to 0.8 wt% with respect to the copolymer.

According to an embodiment of the present invention, the graft copolymer may have an average particle diameter of 200 nm to 350 nm, and while maintaining the average particle diameter of the copolymer composition powder at an appropriate level within this range, the impact of the resin composition There is an effect of simultaneously improving tensile strength and elongation as well as strength.

According to an embodiment of the present invention, the acrylic copolymer is methyl (meth) acrylate monomer units 75 wt% to 95 wt%, 80 wt% to 90 wt%, or 83 wt% to 87 wt% and carbon number 2 to 18 may include 5 wt% to 25 wt%, 10 wt% to 20 wt%, or 13 wt% to 17 wt% of the alkyl (meth)acrylate monomer unit, and within this range, the amount of the copolymer composition powder The average particle diameter can be maintained at an appropriate level. When the content of the methyl (meth) acrylate monomer unit in the acrylic copolymer is not sufficient, the average particle diameter of the copolymer composition powder increases, which may cause a decrease in dispersibility. There is a problem in that the average particle diameter is reduced and agglomeration occurs between the copolymer composition powder particles, which may cause a decrease in dispersibility.

According to an embodiment of the present invention, the methyl (meth) acrylate monomer forming the methyl (meth) acrylate monomer unit of the acrylic copolymer may be methyl acrylate or methyl methacrylate, for example, methyl methacrylic It can be rate.

According to an embodiment of the present invention, the alkyl (meth) acrylate monomer forming the alkyl (meth) acrylate monomer unit of the acrylic copolymer is an alkyl (meth) acrylate having 2 to 18 carbon atoms, and an alkyl (meth) acrylate having 2 to 12 carbon atoms. It may be an alkyl (meth)acrylate, or an alkyl (meth)acrylate having 2 to 6 carbon atoms. Here, (meth)acrylate may mean acrylate or methacrylate. The alkyl (meth) acrylate monomer having 2 to 18 carbon atoms may be ethyl (meth) acrylate, propyl (meth) acrylate or butyl (meth) acrylate, for example, butyl acrylate.

According to an embodiment of the present invention, the acrylic copolymer may have a weight average molecular weight of 8,000,000 g/mol to 12,000,000 g/mol, and improve mechanical properties through a very high molecular weight within this range, as well as high Since it can have a glass transition temperature, the aggregation property is improved when the graft copolymer is mixed with the latex state, and accordingly, the average particle diameter of the powder phase can be maintained at an appropriate level, thereby improving dispersibility. In addition, when the copolymer composition is applied as an impact modifier for the polylactic acid resin, it is possible to increase the tensile strength of the resin composition by inducing entanglement with the polylactic acid resin. As a specific example, the acrylic copolymer may have a weight average molecular weight of 8,500,000 g/mol to 11,500,000 g/mol, 9,000,000 g/mol to 11,000,000 g/mol, or 9,500,000 g/mol to 10,500,000 g/mol, and the acrylic copolymer The weight average molecular weight of the copolymer can be adjusted from the content of the initiator added when preparing the acrylic copolymer.

The present invention provides a method for preparing a copolymer composition for preparing the copolymer composition.

According to an embodiment of the present invention, the method for preparing the copolymer composition comprises 80% to 95% by weight of a rubbery polymer comprising an alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms and an alkyl (meth) having 1 to 18 carbon atoms. ) preparing a graft copolymer comprising 5 wt% to 20 wt% of an acrylate monomer unit (S10); 75 wt% to 95 wt% of methyl (meth)acrylate monomer units and 5 wt% to 25 wt% of alkyl (meth)acrylate monomer units having 2 to 18 carbon atoms, and having a weight average molecular weight of 8,000,000 g/mol to 12,000,000 g/mol preparing an acrylic copolymer (S20); and mixing 90 wt% to 99 wt% of the graft copolymer and 1 wt% to 10 wt% of the acrylic copolymer (S30).

According to an embodiment of the present invention, the step (S10) is a step for preparing a graft copolymer, and polymerizing an alkyl (meth)acrylate monomer having 2 to 18 carbon atoms to prepare a rubbery polymer (S11) and polymerizing the rubbery polymer and an alkyl (meth)acrylate monomer having 1 to 18 carbon atoms to prepare a graft copolymer (S12).

According to an embodiment of the present invention, step (S11) is a step for preparing a rubbery polymer, and may be a step of polymerizing an alkyl (meth)acrylate monomer having 2 to 18 carbon atoms. Here, the alkyl (meth)acrylate monomer having 2 to 18 carbon atoms may be the same as the monomer for forming the alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms of the rubbery polymer described above.

According to one embodiment of the present invention, the step (S11) may be carried out by further including a crosslinking monomer in addition to the alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms. Here, the crosslinkable monomer may be the same as the monomer for forming the crosslinkable monomer unit of the rubbery polymer described above. In addition, when the step (S11) is carried out including a crosslinking monomer, the alkyl (meth)acrylate monomer having 2 to 18 carbon atoms and the crosslinkable monomer are the alkyl (meth)acrylate monomers having 2 to 18 carbon atoms of the rubbery polymer described above, respectively. It may be added in the same amount as the content of the unit formed from the meth)acrylate monomer and the crosslinkable monomer.

According to an embodiment of the present invention, the step (S11) may be carried out by emulsion polymerization, and thus the rubbery polymer may be obtained in the form of a rubbery polymer latex including the rubbery polymer.

According to an embodiment of the present invention, the step (S11) may be carried out by radical polymerization using a peroxide-based, redox, or azo-based initiator, and the redox initiator is, for example, t- It may be at least one selected from the group consisting of butyl hydroperoxide, diisopropylbenzene hydroperoxide and cumene hydroperoxide, and in this case, there is an effect of providing a stable polymerization environment.

In addition, according to an embodiment of the present invention, when the redox initiator is used, ferrous sulfate, disodium ethylenediaminetetraacetate, and sodium formaldehyde sulfoxylate may be further included as the redox catalyst.

In addition, according to an embodiment of the present invention, the emulsifier used in the emulsion polymerization of step (S11) may be at least one selected from the group consisting of anionic emulsifiers, cationic emulsifiers and nonionic emulsifiers, and specifically, alkylaryl sulfonate , alkali methyl alkyl sulfate, alkali alkyl sulfate, soap of fatty acid, alkali oleic acid salt, alkali rosin acid salt, alkali lauric acid salt, sodium diethylhexyl phosphate, phosphonate polyoxyethylene alcohol and phosphonate polyoxy It may be at least one selected from the group consisting of ethylene phenol and the like, and in this case, there is an effect of providing a stable polymerization environment. The emulsifier may be added, for example, in an amount of 5.0 parts by weight or less, 3.0 parts by weight or less, or 0.1 to 2.5 parts by weight based on 100 parts by weight of the total amount of the monomer added in step (S11).

According to an embodiment of the present invention, the emulsion polymerization in step (S11) may be carried out in an aqueous solvent, and the aqueous solvent may be ion-exchanged water.

According to an embodiment of the present invention, step (S12) is a step for preparing a graft copolymer, and may be a step of graft polymerization of an alkyl (meth)acrylate monomer having 1 to 18 carbon atoms in a rubbery polymer. . Here, the alkyl (meth)acrylate monomer having 1 to 18 carbon atoms may be the same as the monomer for forming the alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms in the graft copolymer described above. In addition, the alkyl (meth) acrylate monomer having 1 to 18 carbon atoms may be added in the same amount as the content of the alkyl (meth) acrylate monomer unit having 1 to 18 carbon atoms in the aforementioned graft copolymer.

According to an embodiment of the present invention, the graft polymerization in step (S12) may be carried out by emulsion polymerization, and thus the graft copolymer is in the form of a graft copolymer latex including the graft copolymer. can be obtained.

According to an embodiment of the present invention, the graft polymerization in step (S12) may be carried out by radical polymerization using a peroxide-based, redox, or azo-based initiator, and the redox initiator is For example, it may be at least one selected from the group consisting of t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, and cumene hydroperoxide, and in this case, there is an effect of providing a stable polymerization environment.

In addition, according to an embodiment of the present invention, when the redox initiator is used, ferrous sulfate, sodium ethylenediaminetetraacetate and/or sodium formaldehyde sulfoxylate may be further included as a redox catalyst. .

In addition, according to an embodiment of the present invention, the emulsifier used in the emulsion polymerization in step (S12) may be at least one selected from the group consisting of anionic emulsifiers, cationic emulsifiers and nonionic emulsifiers, and specifically, alkylaryl sulfonate , alkali methyl alkyl sulfate, alkali alkyl sulfate, soap of fatty acid, alkali oleic acid salt, alkali rosin acid salt, alkali lauric acid salt, sodium diethylhexyl phosphate, phosphonate polyoxyethylene alcohol and phosphonate polyoxy It may be at least one selected from the group consisting of ethylene phenol and the like, and in this case, there is an effect of providing a stable polymerization environment. The emulsifier may be added in an amount of 5.0 parts by weight or less, 3.0 parts by weight or less, or 0.01 parts by weight to 2.5 parts by weight, based on 100 parts by weight of the total amount of the rubber polymer and monomer added in step (S12).

According to an embodiment of the present invention, the graft polymerization in step (S12) may be carried out in an aqueous solvent, and the aqueous solvent may be ion-exchanged water.

According to an embodiment of the present invention, the step (S20) is a step for preparing an acrylic copolymer, a step of copolymerizing a methyl (meth) acrylate monomer and an alkyl (meth) acrylate monomer having 2 to 18 carbon atoms. can Here, the methyl (meth) acrylate monomer and the alkyl (meth) acrylate monomer having 2 to 18 carbon atoms are the methyl (meth) acrylate monomer unit and the alkyl (meth) acrylic having 2 to 18 carbon atoms of the acrylic copolymer described above, respectively. It may be the same as the monomer for forming the rate monomer unit. In addition, the methyl (meth) acrylate monomer and the alkyl (meth) acrylate monomer having 2 to 18 carbon atoms are the methyl (meth) acrylate monomer unit and the alkyl (meth) acrylic having 2 to 18 carbon atoms of the acrylic copolymer described above. It may be added in the same content as the content of the rate monomer unit.

According to an embodiment of the present invention, the step (S20) is performed separately from the step (S10), and simultaneously with the step (S10), before the step (S10), or the step (S10) It can be carried out after

According to an embodiment of the present invention, the step (S20) may be carried out by emulsion polymerization, and thus the acrylic copolymer may be obtained in the form of an acrylic copolymer latex including the acrylic copolymer.

According to an embodiment of the present invention, the step (S20) may be carried out by radical polymerization using a peroxide-based, redox, or azo-based initiator, and the redox initiator is, for example, t- It may be at least one selected from the group consisting of butyl hydroperoxide, diisopropylbenzene hydroperoxide and cumene hydroperoxide, and in this case, there is an effect of providing a stable polymerization environment.

In addition, according to an embodiment of the present invention, when the redox initiator is used, ferrous sulfate, disodium ethylenediaminetetraacetate, and sodium formaldehyde sulfoxylate may be further included as the redox catalyst.

In addition, according to an embodiment of the present invention, the emulsifier used in the emulsion polymerization in step (S20) may be at least one selected from the group consisting of anionic emulsifiers, cationic emulsifiers and nonionic emulsifiers, and specifically, alkylaryl sulfonate , alkali methyl alkyl sulfate, alkali alkyl sulfate, soap of fatty acid, alkali oleic acid salt, alkali rosin acid salt, alkali lauric acid salt, sodium diethylhexyl phosphate, phosphonate polyoxyethylene alcohol and phosphonate polyoxy It may be at least one selected from the group consisting of ethylene phenol and the like, and in this case, there is an effect of providing a stable polymerization environment. The emulsifier may be added, for example, in an amount of 5.0 parts by weight or less, 3.0 parts by weight or less, or 0.1 to 2.5 parts by weight based on 100 parts by weight of the total amount of the monomer added in step (S20).

According to an embodiment of the present invention, the emulsion polymerization of step (S20) may be carried out in an aqueous solvent, and the aqueous solvent may be ion-exchanged water.

According to an embodiment of the present invention, the acrylic copolymer prepared in step (S20) may have a weight average molecular weight of 8,000,000 g/mol to 12,000,000 g/mol, and specifically, 8,500,000 g/mol to 11,500,000 g/mol mol, 9,000,000 g/mol to 11,000,000 g/mol, or 9,500,000 g/mol to 10,500,000 g/mol, the weight average molecular weight of the acrylic copolymer may be adjusted from the content of the initiator input in the step (S20). can

According to an embodiment of the present invention, in step (S30), the graft copolymer prepared in step (S10) and the acrylic copolymer prepared in step (S20) are mixed to prepare a copolymer composition. may be a step. At this time, the graft copolymer and the acrylic copolymer are 90 wt% to 99 wt%, 93 wt% to 99 wt%, 95 wt% of the graft copolymer in order to secure dispersibility and powder properties as described above. % to 99 wt%, or 95 wt% to 98 wt% and 1 wt% to 10 wt%, 1 wt% to 7 wt%, 1 wt% to 5 wt%, or 2 wt% to 3 wt% acrylic copolymer can be mixed with

According to an embodiment of the present invention, the graft copolymer prepared in the step (S10) may be prepared in the state of the graft copolymer latex including the graft copolymer as described in the step (S12) above. And, the acrylic copolymer prepared in the step (S20) may be prepared in the state of the acrylic copolymer latex including the acrylic copolymer as described in the step (S20) above. Accordingly, the mixing of the step (S30) may be carried out in the state of the graft copolymer latex and the acrylic copolymer latex, and in this case, according to the step (S40) that may be carried out after the step (S30) The graft copolymer and the acrylic copolymer may exist in a uniformly mixed form in the powder phase prepared by agglomeration and drying, and the agglomeration property is improved by the acrylic copolymer having a high glass transition temperature, thereby reducing the average particle size of the powder phase. It can be maintained at an appropriate level, which has the effect of improving dispersibility.

According to an embodiment of the present invention, the method for preparing the copolymer composition may include aggregating and drying the copolymer latex composition prepared in the step (S30) (S40). By performing the step (S40), a copolymer composition can be obtained in a powder phase, and the agglomeration and drying can be carried out by a conventional method within a range that does not change the average particle diameter of the powder phase of the copolymer composition. have.

The present invention provides a resin composition comprising the copolymer composition as an impact modifier.

According to an embodiment of the present invention, the resin composition may include the copolymer composition and the polylactic acid resin.

According to an embodiment of the present invention, the polylactic acid resin is a polymer prepared by using lactic acid as a monomer, and includes poly(L-lactide), poly(D-lactide) and poly(L,D). -lactic acid) may be at least one selected from the group consisting of. The poly(L-lactide) is polymerized using L-lactic acid as a monomer, poly(D-lactide) is polymerized using D-lactic acid as a monomer, and poly(L,D-lactide) is L -Lactic acid and D-lactic acid are copolymerized as monomers.

According to an embodiment of the present invention, according to an embodiment of the present invention, the polylactic acid resin has a weight average molecular weight of 10,000 g/mol or more, 30,000 g/mol or more, 50,000 g/mol or more, or 100,000 g/mol or more or more, and may be 500,000 g/mol or less, 450,000 g/mol or less, 400,000 g/mol, or 300,000 g/mol or less, and may be applied in a dehydrated state when applied to the resin composition.

According to an embodiment of the present invention, the polylactic acid resin may have a PDI of 1.0 to 3.0, 1.2 to 2.5, or 1.5 to 2.0. In addition, the polylactic acid resin may have a glass transition temperature (Tg) of 45 ℃ to 65 ℃, 50 ℃ to 60 ℃, or 52 ℃ to 58 ℃, the melting temperature (Tm) is 155 ℃ to 170 ℃, 160 It may be ℃ to 170 ℃, or 162 ℃ to 168 ℃.

According to an embodiment of the present invention, the resin composition comprises 0.5% to 20.0% by weight of the copolymer composition, 5% to 20% by weight, or 5% to 15% by weight, and 80.0% to 99.5% by weight of the polylactic acid resin Weight%, 80% to 95% by weight, or 85% to 95% by weight may be included, and within this range, the impact strength, tensile strength and elongation of the resin composition are all excellent effects.

According to an embodiment of the present invention, the resin composition may optionally include a lubricant, a heat stabilizer, a flame retardant, an antioxidant, a light stabilizer, a reaction catalyst, a mold release agent, a pigment, an antistatic agent, a conductivity imparting agent, an EMI shielding agent, a magnetization agent, It may further include one or more additives selected from the group consisting of a crosslinking agent, an antibacterial agent, a processing aid, a metal deactivator, a flame retardant, a fluorine-based anti-drip agent, an inorganic filler, glass fiber, a friction and abrasion resistance agent, and a coupling agent. At this time, the additive may be included in an amount as needed with respect to 100 parts by weight of the polylactic acid resin in the resin composition, or 100 parts by weight of the total of the polylactic acid resin and the copolymer composition.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein.

Example

Example 1

<Production of graft copolymer latex>

In a reactor equipped with a stirrer, thermometer, nitrogen inlet and circulation condenser, based on 100 parts by weight of butyl acrylate, allyl methacrylate and methyl methacrylate, 90 parts by weight of ion-exchanged water, 0.02 parts by weight of sodium bicarbonate as an additive , 0.001 parts by weight of ferrous sulfate, and 0.02 parts by weight of disodium ethylenediaminetetraacetate were added, and the internal temperature of the reactor was maintained at 55° C. under a nitrogen atmosphere. As a monomer pre-emulsion for preparing a rubbery polymer, 40 parts by weight of ion-exchanged water, 0.8 parts by weight of sodium lauryl sulfate, 89.5 parts by weight of butyl acrylate and 0.5 parts by weight of allyl methacrylate were added to prepare a monomer pre-emulsion. The monomer preemulsion, 0.07 parts by weight of t-butyl hydroperoxide, and 0.1 parts by weight of sodium formaldehyde sulfoxylate were continuously introduced into the reactor at an internal temperature of 55° C. for 3 hours to proceed with polymerization. Then, 30 minutes after the addition of the monomer pre-emulsion was completed, 0.01 parts by weight of t-butyl hydroperoxide and 0.01 parts by weight of sodium formaldehyde sulfoxylate were further added and aged for 1 hour to prepare a rubbery polymer latex.

After the entire amount of the prepared rubbery polymer latex was put into the sealed reactor, the temperature inside the reactor was maintained at 55°C. As a monomer pre-emulsion for preparing the graft copolymer, 15 parts by weight of ion-exchanged water, 0.2 parts by weight of sodium lauryl sulfate, and 10 parts by weight of methyl methacrylate were added to prepare a monomer pre-emulsion. The monomer preemulsion, 0.03 parts by weight of t-butyl hydroperoxide and 0.03 parts by weight of sodium formaldehyde sulfoxylate were continuously added to the reactor at an internal temperature of 55° C. for 1 hour to proceed with a polymerization reaction. Then, 30 minutes after the addition of the monomer pre-emulsion is completed, 0.01 parts by weight of t-butyl hydroperoxide and 0.01 parts by weight of sodium formaldehyde sulfoxylate are additionally added and aged for 1 hour to prepare a graft copolymer latex did.

<Production of acrylic copolymer latex>

In a reactor equipped with a stirrer, thermometer, nitrogen inlet and circulation condenser, 100 parts by weight of ion-exchanged water, 0.002 parts by weight of ferrous sulfate, disodium ethylenediaminetetra based on 100 parts by weight of methyl methacrylate and butyl acrylate. 0.04 parts by weight of acetate was added, and the temperature inside the reactor was maintained at 40° C. under a nitrogen atmosphere. As a monomer pre-emulsion for preparing the acrylic copolymer, 70 parts by weight of ion-exchanged water, 0.6 parts by weight of sodium lauryl sulfate, 85 parts by weight of methyl methacrylate, and 15 parts by weight of butyl acrylate were added to prepare a monomer pre-emulsion. In the reactor where the internal temperature is maintained at 40 ° C., the monomer pre-emulsion, 0.001 parts by weight of t-butyl hydroperoxide and 0.05 parts by weight of sodium formaldehyde sulfoxylate are continuously added for 3 hours to proceed with the polymerization reaction, Coalesced latex was prepared.

<Preparation of copolymer composition>

95 parts by weight of the prepared graft copolymer latex (based on solid content) and 5 parts by weight of the prepared acrylic copolymer latex (based on solid content) were mixed in a latex state to prepare a copolymer latex composition. After maintaining the temperature of the prepared copolymer latex composition at 40 ° C., and adding 4 parts by weight of calcium chloride based on 100 parts by weight of the copolymer latex composition (based on solid content) to agglomerate to obtain a slurry, the obtained slurry is ion exchanged After washing 2 to 3 times with water, the washing water was removed through filtration and dried using a small fluidized bed dryer to obtain a copolymer composition in powder form.

<Preparation of resin composition>

Based on 100 parts by weight of the total polylactic acid resin and the copolymer composition, 90 parts by weight of a polylactic acid resin (product name: PLA 4032D, manufacturer: NatureWorks) and 10 parts by weight of the copolymer composition powder prepared above, 0.5 parts by weight of a lubricant and a heat stabilizer 0.2 parts by weight was melt-kneaded at 190° C. and 30 rpm for 10 minutes using a Rheomix 600 batch mixer manufactured by Haake to prepare a resin composition.

Example 2

In Example 1, when preparing the copolymer composition, 98 parts by weight (based on solids) instead of 95 parts by weight (based on solids) of graft copolymer latex, 5 parts by weight of acrylic copolymer latex (based on solids) instead of 2 parts by weight (based on solids) It was carried out in the same manner as in Example 1, except that parts (based on solid content) were mixed.

Example 3

In Example 1, in the preparation of the resin composition, the polylactic acid resin was mixed in 95 parts by weight instead of 90 parts by weight, and the copolymer composition powder was mixed in 5 parts by weight instead of 10 parts by weight. did.

Comparative Example 1

100 parts by weight of polylactic acid resin (product name: PLA 4032D, manufacturer: NatureWorks) was melted at 190° C. and 30 rpm for 10 minutes using a Rheomix 600 batch mixer manufactured by Haake.

Comparative Example 2

<Production of graft copolymer latex>

In a reactor equipped with a stirrer, thermometer, nitrogen inlet and circulation condenser, based on 100 parts by weight of butyl acrylate, allyl methacrylate and methyl methacrylate, 90 parts by weight of ion-exchanged water, 0.02 parts by weight of sodium bicarbonate as an additive , 0.001 parts by weight of ferrous sulfate, and 0.02 parts by weight of disodium ethylenediaminetetraacetate were added, and the internal temperature of the reactor was maintained at 55° C. under a nitrogen atmosphere. As a monomer pre-emulsion for preparing a rubbery polymer, 40 parts by weight of ion-exchanged water, 0.8 parts by weight of sodium lauryl sulfate, 89.5 parts by weight of butyl acrylate and 0.5 parts by weight of allyl methacrylate were added to prepare a monomer pre-emulsion. The monomer preemulsion, 0.07 parts by weight of t-butyl hydroperoxide, and 0.1 parts by weight of sodium formaldehyde sulfoxylate were continuously introduced into the reactor at an internal temperature of 55° C. for 3 hours to proceed with polymerization. Then, 30 minutes after the addition of the monomer pre-emulsion was completed, 0.01 parts by weight of t-butyl hydroperoxide and 0.01 parts by weight of sodium formaldehyde sulfoxylate were further added and aged for 1 hour to prepare a rubbery polymer latex.

After the entire amount of the prepared rubbery polymer latex was put into the sealed reactor, the temperature inside the reactor was maintained at 55°C. As a monomer pre-emulsion for preparing the graft copolymer, 15 parts by weight of ion-exchanged water, 0.2 parts by weight of sodium lauryl sulfate, and 10 parts by weight of methyl methacrylate were added to prepare a monomer pre-emulsion. The monomer preemulsion, 0.03 parts by weight of t-butyl hydroperoxide and 0.03 parts by weight of sodium formaldehyde sulfoxylate were continuously added to the reactor at an internal temperature of 55° C. for 1 hour to proceed with a polymerization reaction. Then, 30 minutes after the addition of the monomer pre-emulsion is completed, 0.01 parts by weight of t-butyl hydroperoxide and 0.01 parts by weight of sodium formaldehyde sulfoxylate are additionally added and aged for 1 hour to prepare a graft copolymer latex did.

<Preparation of graft copolymer powder>

The temperature of the prepared graft copolymer latex was maintained at 40° C., and 4 parts by weight of calcium chloride was added with respect to 100 parts by weight of the graft copolymer latex (based on solid content) to obtain a slurry, and then the obtained slurry was prepared After washing 2 to 3 times with ion-exchanged water, the washing water was removed through filtration and dried using a small fluidized bed dryer to obtain a graft copolymer in powder form.

<Preparation of resin composition>

Based on 100 parts by weight of the total polylactic acid resin and the graft copolymer, 90 parts by weight of a polylactic acid resin (product name: PLA 4032D, manufacturer: NatureWorks) and 10 parts by weight of the prepared graft copolymer powder, 0.5 parts by weight of a lubricant and 0.2 parts by weight of the heat stabilizer was melt-kneaded at 190° C. and 30 rpm for 10 minutes using a Rheomix 600 batch mixer manufactured by Haake to prepare a resin composition.

Comparative Example 3

In Example 1, when preparing the copolymer composition, 85 parts by weight (based on solids) instead of 95 parts by weight (based on solids) of the graft copolymer latex, and 5 parts by weight of acrylic copolymer latex (based on solids) instead of 15 parts by weight (based on solids) It was carried out in the same manner as in Example 1, except that parts (based on solid content) were mixed.

Comparative Example 4

In Example 1, when preparing the graft copolymer latex, butyl acrylate was added in an amount of 96.5 parts by weight instead of 89.5 parts by weight, and methyl methacrylate was added in an amount of 3 parts by weight instead of 10 parts by weight. was carried out in the same way as

Comparative Example 5

In Example 1, when preparing the graft copolymer latex, butyl acrylate was added in an amount of 74.5 parts by weight instead of 89.5 parts by weight, and methyl methacrylate was added in an amount of 25 parts by weight instead of 10 parts by weight. was carried out in the same way as

Comparative Example 6

In Example 1, when preparing the acrylic copolymer latex, 70 parts by weight of methyl methacrylate instead of 85 parts by weight and 30 parts by weight of butyl acrylate instead of 15 parts by weight were added. The same method as in Example 1 was carried out with

Comparative Example 7

In Example 1, when preparing the acrylic copolymer latex, methyl methacrylate in 97 parts by weight instead of 85 parts by weight and butyl acrylate in 3 parts by weight instead of 15 parts by weight The same method as in Example 1 was carried out with

Comparative Example 8

In Example 1, when preparing the acrylic copolymer latex, t-butyl hydroperoxide was added in 0.002 parts by weight instead of 0.001 parts by weight, and sodium formaldehyde sulfoxylate was added in 0.10 parts by weight instead of 0.05 parts by weight. It was carried out in the same manner as in Example 1.

Experimental example

The average particle diameter of the graft copolymer particles prepared in Examples 1 to 3 and Comparative Examples 1 to 8, the swelling index of the graft copolymer, the average particle diameter of the copolymer composition powder or the graft copolymer powder, and the acrylic copolymer The weight average molecular weight of was measured in the following way, and is shown in Tables 1 and 2 together with each composition.

In addition, for the resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 8, impact strength, tensile strength and elongation were measured by the following method, and are shown in Tables 1 and 2 below.

* Average particle diameter of graft copolymer particles (nm): After diluting each graft copolymer latex prepared in Examples 1 to 3 and Comparative Examples 2 to 8 in distilled water to a concentration of 200 ppm or less, respectively, at room temperature (23 ℃) using NICOMP 380 (PSS), using a dynamic laser light scattering (Dynamic Laser Light Scattering) method according to the intensity Gaussian distribution (Intensity Gaussian Distribution) of the graft copolymer particles dispersed in the graft copolymer latex The average particle diameter was measured.

* Swelling index of the graft copolymer: A portion of the graft copolymer powder prepared in Examples 1 to 3 and Comparative Examples 2 to 8 was collected and the weight was measured. After that, the graft copolymer powder was added to toluene and stored for 24 hours, the weight of the swollen graft copolymer was measured, and the swelling index was calculated according to Equation 1 below.

[Equation 1]

Swelling index of graft copolymer = weight of graft copolymer swollen in toluene/weight of graft copolymer powder

* Average particle diameter (㎛) of copolymer composition powder (or graft copolymer powder): Sympatec the average particle diameter of the copolymer composition powder or graft copolymer powder prepared in Examples 1 to 3 and Comparative Examples 2 to 8 It was measured using the company's Particle Size Analyzer.

* Weight average molecular weight (Mw, g/mol) of the acrylic copolymer: The acrylic copolymer prepared in Examples 1 to 3 and Comparative Examples 3 to 8 was dissolved in tetrahydrofuran (THF) to a concentration of 0.25 wt% Then, the weight average molecular weight was measured under the following conditions by gel permeation chromatography (GPC, Gel Permeation Chromatography).

- Column: A combination of two PLgel Olexis (Polymer Laboratories) columns and one PLgel mixed-C (Polymer Laboratories) column is used.

- Solvent: THF

- Flow rate: 1.0 ml/min

- Column temperature: 40 ℃

- Detector: Differential refractive index detector (RI)

- Standard material: PS (polystyrene)

* Impact strength (Notched Izod Impact Streangth, kgf cm/cm ² ): The resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 8 were compression molded at 200 ° C. for 10 minutes at 0.20 MPa to 3.2 mm (1 /8") thick specimen was prepared. A notch having a depth of 2.54 mm was formed in the prepared specimen, and the impact strength at room temperature (23±3° C.) was measured according to ASTM D256, Method A.

* Tensile strength (Tensile Strength, MPa) and elongation (Elongation, %): The resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 8 were compression molded at 200 ° C. for 10 minutes at 0.20 MPa to 3.2 mm (1 /8") thick specimen was prepared. Using the prepared specimen, a specimen for measuring tensile strength and elongation was prepared according to the ASTM D638 method, and a test device, U.T.M (Manufacturer: Instron Corporation, model name: 4466), after pulling the cross head speed to 200 mm/min, the point at which the specimen was cut was measured, and the tensile strength was measured from the load values for thickness and width, and the initial length Elongation was determined from the length after contrast stretching.

division Example One 2 3 rubbery polymer BA ¹⁾ (parts by weight) 89.5 89.5 89.5 AMA ²⁾ (parts by weight) 0.5 0.5 0.5 graft copolymer MMA ³⁾ (parts by weight) 10.0 10.0 10.0 average particle diameter (nm) 250 250 250 swelling index 6.2 6.2 6.2 Acrylic copolymer MMA ³⁾ (parts by weight) 85.0 85.0 85.0 BA ¹⁾ (parts by weight) 15.0 15.0 15.0 Mw (g/mol) 10,000,000 10,000,000 10,000,000 copolymer composition graft copolymer (parts by weight) 95.0 98.0 95.0 Acrylic copolymer (parts by weight) 5.0 2.0 5.0 Powder average particle size (μm) 162 195 162 resin composition PLA ⁴⁾ (parts by weight) 90.0 90.0 95.0 copolymer composition (parts by weight) 10.0 10.0 5.0 impact strength (kgf cm/cm ² ) 5.2 5.8 4.2 The tensile strength (MPa) 72 56 52 elongation (%) 21 17 16 1) BA: butyl acrylate
2) AMA: allyl methacrylate
3) MMA: methyl methacrylate
4) PLA: polylactic acid resin

division comparative example One 2 3 4 5 6 7 8 rubbery polymer BA ¹⁾ (parts by weight) - 89.5 89.5 96.5 74.5 89.5 89.5 89.5 AMA ²⁾ (parts by weight) - 0.5 0.5 0.5 0.5 0.5 0.5 0.5 graft copolymer MMA ³⁾ (parts by weight) - 10.0 10.0 3.0 25.0 10.0 10.0 10.0 average particle diameter (nm) - 250 250 252 245 250 250 250 swelling index - 6.2 6.2 6.5 6.0 6.2 6.2 6.2 Acrylic copolymer MMA ³⁾ (parts by weight) - - 85.0 85.0 85.0 70.0 97.0 85.0 BA ¹⁾ (parts by weight) - - 15.0 15.0 15.0 30.0 3.0 15.0 Mw (g/mol) - - 10,000,000 10,000,000 10,000,000 9,500,000 10,200,000 5,000,000 copolymer composition graft copolymer (parts by weight) - 100.0 85.0 95.0 95.0 95.0 95.0 95.0 Acrylic copolymer (parts by weight) - - 15.0 5.0 5.0 5.0 5.0 5.0 Powder average particle size (μm) - 315 122 684 127 326 84 165 resin composition PLA ⁴⁾ (parts by weight) 100.0 90.0 90.0 90.0 90.0 90.0 90.0 90.0 copolymer composition (parts by weight) - 10.0 10.0 10.0 10.0 10.0 10.0 10.0 impact strength (kgf cm/cm ² ) 0.5 4.3 4.5 0.2 1.1 5.6 5.1 4.5 The tensile strength (MPa) 51 35 122 55 56 65 75 38 elongation (%) 15 5 9 6 22 7 8 6 1) BA: butyl acrylate
2) AMA: allyl methacrylate
3) MMA: methyl methacrylate
4) PLA: polylactic acid resin

As shown in Tables 1 and 2, the copolymer composition prepared according to the present invention maintains the average particle diameter of the powder at an appropriate level, while maintaining the same level of tensile strength and elongation as compared to Comparative Example 1 using only polylactic acid resin or its It was confirmed that, while improving to the above level, the impact strength was significantly improved.

On the other hand, in the case of Comparative Example 2, in which the powder was prepared only by the graft copolymer itself without including the acrylic copolymer, it was confirmed that the average particle diameter of the powder was increased compared to the copolymer composition powder according to the embodiment of the present invention, and the tensile strength It was confirmed that the strength and elongation were rather decreased. In addition, even if the acrylic copolymer was included, in the case of Comparative Example 3 including an excessive amount, it was confirmed that the tensile strength was rapidly increased, and the elongation was rather decreased.

In addition, in the case of Comparative Example 4, in which the ratio of the core was excessively increased during the preparation of the graft copolymer, the dispersibility was lowered due to the abrupt increase in the average particle size of the powder, and it was confirmed that the impact strength was rather poor and the elongation was also lowered. In the case of Comparative Example 5, in which the proportion of the shell was excessively increased, the content of the rubber polymer in the graft copolymer was not sufficient, so it was confirmed that the improvement in impact strength was very insignificant.

In addition, in the case of Comparative Examples 6 and 7, in which the composition of each monomer was outside the preferred range during the preparation of the acrylic copolymer, it was confirmed that the average particle diameter of the powder increased or decreased outside the appropriate level, and thus the elongation was lowered. could confirm that

In addition, in the case of Comparative Example 8, in which the weight average molecular weight of the acrylic copolymer was not sufficiently high, it was confirmed that the tensile strength and elongation were decreased.

From these results, when the copolymer composition of the present invention is applied as an impact modifier to the polylactic acid resin, while minimizing the decrease in transparency of the low refractive index polylactic acid resin, the high rubber content improves the impact resistance of the resin composition At the same time, it was confirmed that the dispersibility and powder properties were improved at the same time, and the tensile strength and elongation were excellent.

Claims (11)

90% to 99% by weight of the graft copolymer and 1% to 10% by weight of the acrylic copolymer,
The graft copolymer is 80 wt% to 95 wt% of a rubbery polymer comprising an alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms and 5 wt% to 20 wt% of an alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms. % by weight,
The acrylic copolymer includes 75 wt% to 95 wt% of a methyl (meth)acrylate monomer unit and 5 wt% to 25 wt% of an alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms, and has a weight average molecular weight of 8,000,000 g/mol to 12,000,000 g/mol. According to claim 1,
The copolymer composition is in the form of a powder,
The average particle diameter of the powder phase is 100㎛ to 300㎛ copolymer composition. According to claim 1,
The graft copolymer is 85 wt% to 95 wt% of a rubbery polymer comprising an alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms and 5 wt% to 15 wt% of an alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms. % by weight of the copolymer composition. According to claim 1,
The rubbery polymer comprises a crosslinkable monomer unit,
The graft copolymer is a copolymer composition having a swelling index of 3 to 10. According to claim 1,
The graft copolymer has an average particle diameter of 200 nm to 350 nm. According to claim 1,
The acrylic copolymer is a copolymer composition comprising 80 wt% to 90 wt% of a methyl (meth)acrylate monomer unit and 10 wt% to 20 wt% of an alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms. Graph comprising 80 wt% to 95 wt% of a rubbery polymer comprising an alkyl (meth)acrylate monomer unit having 2 to 18 carbon atoms and 5 wt% to 20 wt% of an alkyl (meth)acrylate monomer unit having 1 to 18 carbon atoms preparing a copolymer (S10);
75 wt% to 95 wt% of methyl (meth)acrylate monomer units and 5 wt% to 25 wt% of alkyl (meth)acrylate monomer units having 2 to 18 carbon atoms, and having a weight average molecular weight of 8,000,000 g/mol to 12,000,000 g/mol preparing an acrylic copolymer (S20); and
A method for preparing a copolymer composition comprising the step (S30) of mixing 90 wt% to 99 wt% of the graft copolymer and 1 wt% to 10 wt% of the acrylic copolymer. 8. The method of claim 7,
The graft copolymer prepared in step (S10) is prepared in the state of the graft copolymer latex containing the graft copolymer,
The acrylic copolymer prepared in step (S20) is prepared in the state of an acrylic copolymer latex containing the acrylic copolymer,
The mixing of the step (S30) is a copolymer composition manufacturing method that is carried out in the state of the graft copolymer latex and the acrylic copolymer latex. 9. The method of claim 8,
The method for preparing the copolymer composition comprises:
A method for preparing a copolymer composition comprising the step (S40) of agglomeration and drying the copolymer latex composition prepared in the step (S30). A resin composition comprising the copolymer composition and polylactic acid resin according to any one of claims 1 to 6. 11. The method of claim 10,
The resin composition is a resin composition comprising 0.5 wt% to 20.0 wt% of the copolymer composition and 80.0 wt% to 99.5 wt% of the polylactic acid resin.