KR20150030847A - Acrylate-conjugated diene-aromatic vinyl-based copolymer and poly(lactic acid) resin composition comprising the same - Google Patents

Abstract

In the present invention, provided are a MBS based graft copolymer, which is allowed to improve the dispersing efficiency of impact reinforcing agents by increasing compatibility with poly(lactic acid) and introduces a certain emulsifying agent in a shell layer to significantly improve brittleness which is a disadvantage of the poly(lactic acid), a manufacturing method thereof and a poly(lactic acid) resin composition including the same. In the present invention, provided is a MBS based graft copolymer, comprising a rubber latex with an inner layer of a conjugated diene based rubber and an outer layer of an acrylic based polymer; and a multilayred core-shell structure as a graft shell to surround the rubber latex wherein at least one among the inner layer included in the core or the outer layer included in the shell or the both layer of an inner layer and an outer layer comprise an emulsifying agent denoted by chemical formula 1, thereby being manufactured wherein the poly(lactic acid) composition comprises 10-30 wt% of an acrylate-conjugated diene-aromatic vinyl based copolymer and 70-90 wt% of a poly(lactic acid) resin.

Description

[0001] The present invention relates to an acrylate-conjugated diene-aromatic vinyl copolymer and a poly (lactic acid) resin composition containing the same,

The present invention relates to an acrylate-conjugated diene-aromatic vinyl copolymer (hereinafter referred to as " MBS-based copolymer ") and a poly lactic acid resin composition containing the same. More particularly, In the graft copolymerization step for the synthesis of an acrylate-conjugated diene-aromatic vinyl copolymer having a shell structure, a polyethylene glycol-based monomer is contained, and a graff at the periphery of the core constituting the polylactic acid resin and MBS- The entanglement structure of the polymer chains is increased and the viscosity and elasticity of the blending of the polylactic acid resin and the MBS type copolymer are increased to increase the compatibility between the MBS type copolymer and the polylactic acid resin, The dispersibility of the impact modifier in the poly (lactic acid) resin is increased, and the brittleness, which is a disadvantage of the poly (lactic acid) resin, Capable of line acrylate-conjugated diene-relates to an aromatic vinyl copolymer and the polylactic acid resin composition comprising the same.

In general, the environmental pollution problem caused by the waste polymer is becoming a social problem, so the need for environmentally friendly polymer materials is required. In recent years, developed countries such as Europe have been striving to limit the use of hazardous substances that could cause environmental pollution problems and to use recycled products.

On the other hand, polylactic acid is used in a large amount to account for 20% of the entire bioplastic market due to its low cost and excellent physical properties compared with other biodegradable plastics. The use of polylactic acid is also used for automobile parts, Parts and so on. However, existing poly (lactic acid) resins are easily broken in the case of thin film products because of lack of moldability and mechanical strength, and heat resistance is low, so that when the external temperature rises by 60 ° C or more, there is a problem that the shape of the molded product is deformed.

In recent years, research is underway to blend polylactic acid with a general-purpose resin. When the polylactic acid is blended with a general-purpose resin, the use amount of the general-purpose resin derived from the petroleum raw material can be suppressed. As a result, the use amount of the petroleum raw material can be suppressed and also the generation of carbon dioxide gas and the heat of combustion can be lowered How to reduce the environmental burden is attracting attention.

Recently, a method of increasing the heat resistance and the like by using a composition containing an acrylonitrile-butadiene-styrene (ABS) resin as a polylactic acid resin has been proposed. Styrenic thermoplastic resins such as ABS resins are excellent in impact resistance, mechanical strength, surface characteristics and processability, and are widely used in electric / electronic products, automobile interior / exterior parts, general goods, and the like.

In particular, when an ABS resin and a polyester resin are alloyed with poly (lactic acid) in order to ensure chemical resistance and impact resistance, there is a problem in that the compatibility between these resins is not sufficient and the physical properties as expected can not be improved.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems of the prior art and to provide a method for improving the dispersibility of an impact modifier by increasing compatibility with a poly (lactic acid) resin, An MBS-based graft copolymer in which an emulsifier is introduced, a process for producing the MBS-based graft copolymer, and a poly (lactic acid) resin composition containing the same. Another object of the present invention is to provide an environmentally friendly poly (lactic acid) resin composition having excellent impact strength.

The above and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention has a multi-layer core-shell structure composed of an inner layer of a conjugated diene rubber, a rubber latex of an outer layer of an acrylic polymer, and a graft shell surrounding the rubber latex, The present invention provides an MBS-based graft copolymer obtained by either one of an inner layer constituting an outer layer constituting the shell or an outer layer constituting the shell, or both an inner layer and an outer layer, each containing an emulsifier represented by the following formula:

[Chemical Formula 1]

Wherein R is alkyl having from 12 to 14 carbon atoms, n is an integer from 4 to 8, and m is 1 or 2.

According to one embodiment of the present invention, preferably, "sodium salt of polyoxyethylene alkyl ether phosphate" (hereinafter referred to as "PAP") may be used as the emulsifier.

This is to improve the problem that the impact strength is relatively lowered as described in the following examples when a core-shell structure incorporating an outer layer of an acrylic polymer surrounding the inner layer of the rubber core is used , It is introduced into the grafting step of the specific emulsifier shown in the present invention to increase the grafting efficiency and maintain the impact strength.

The emulsifier represented by the formula 1 used in the present invention may be contained in the range of 1.0 to 4.0 wt% based on the total weight of the total monomers constituting the shell. When the amount is outside the above range, for example, when the amount is less than 1.0% by weight, the impact strength is lowered. When the amount is used in excess of 4.0% by weight, the dispersibility is lowered and the coagulation is not performed well. Can be.

Specifically, the emulsifier of Formula 1 may include, but is not limited to, polyoxyethylene-9-lauryl ether, polyoxyethylene-9-stearyl ether, polyoxyethylene-8-stearyl ether, polyoxyethylene- Lauryl ether, polyoxyethylene-3,5-lauryl ether, and polyoxyethylene-2,3-lauryl ether can be used.

Particularly, in the MBS-based copolymer of the present invention, the inner layer is a copolymer of the crosslinkable monomer and the crosslinking monomer in an amount of 1.0 to 10 parts by weight based on the total weight of all the monomers constituting the inner layer. To 4.0% by weight, preferably from 2.0 to 3.0% by weight. Within this range, the impact strength is excellent.

According to the present invention, there is also provided a method for producing a rubber latex, which comprises forming an inner layer of a conjugated diene rubber core and then forming an outer layer of an acrylic polymer so as to surround the inner layer to obtain a rubber latex, Methacrylate polymer, wherein the inner layer, the outer layer and the outermost layer are each obtained under the emulsifying agent represented by the above formula (1) MBS-based graft copolymer.

The acrylate-conjugated diene-aromatic vinyl-based copolymer of the present invention for achieving the above objects comprises (1) a conjugated diene-based rubber polymer core; And (2) a shell obtained by graft copolymerizing the (meth) acrylic acid alkyl ester monomer and the polyethylene glycol monomer onto the conjugated diene rubber polymer core.

In order to accomplish the above object, the present invention also provides a method for producing an acrylate-conjugated diene-aromatic vinyl copolymer, comprising: (a) preparing a core to produce a conjugated diene-based rubber polymer core; And (b) 10 to 30% by weight of a (meth) acrylic acid alkyl ester monomer and 10 to 30% by weight of a polyethylene glycol monomer in the presence of 50 to 80% by weight of a conjugated diene rubber polymer core obtained in the core preparation step Graft copolymerization to obtain an acrylate-conjugated diene-aromatic vinyl-based copolymer having a core-shell structure, wherein the inner layer constituting the core or the outer layer constituting the shell Or both the inner layer and the outer layer are each obtained by including an emulsifier represented by the following formula (1)

[Chemical Formula 1]

Wherein R is alkyl having from 12 to 14 carbon atoms, n is an integer from 4 to 8, and m is 1 or 2.

The polylactic acid resin composition of the present invention comprises 10 to 30% by weight of the obtained acrylate-conjugated diene-aromatic vinyl copolymer and 70 to 90% by weight of the polylactic acid resin.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, by increasing the compatibility with a poly (lactic acid) resin and by increasing the dispersing effect of an acrylate-conjugated diene-aromatic vinyl copolymer as an impact modifier in poly It is possible to remarkably improve the brittleness which is a disadvantage of the resin, and at the same time to provide an eco-friendly poly (lactic acid) resin composition excellent in impact strength.

Hereinafter, the present invention will be described in more detail.

The present inventors have found that when a graft copolymerization step of a butadiene-based rubber latex having excellent impact resistance is carried out by copolymerizing a polyethylene glycol monomer together with a vinyl monomer, a core-shell acrylate-conjugated diene-aromatic vinyl based copolymer Wherein the inner layer of the core or the outer layer constituting the shell or both of the inner layer and the outer layer are each provided with an emulsifier represented by the following formula 1 to serve as a crosslinking agent, Conjugated diene-aromatic vinyl copolymer and the poly (lactic acid) resin as a result of the increase of the size of the acrylate-conjugated diene-aromatic vinyl copolymer and the dispersion effect of the impact modifier in the poly (lactic acid) resin And the brittleness, which is a disadvantage of the polylactic acid resin, And the present invention has been completed.

[Chemical Formula 1]

Wherein R is alkyl having from 12 to 14 carbon atoms, n is an integer from 4 to 8, and m is 1 or 2.

The present invention relates to (1) a conjugated diene rubber polymer core; And (2) a shell obtained by graft copolymerizing a (meth) acrylic acid alkyl ester monomer and a polyethylene glycol monomer onto the conjugated diene rubber polymer core, wherein the inner layer constituting the core or the outline constituting the shell Any one of the layers or the inner layer Wherein the acrylate-conjugated diene-aromatic vinyl-based copolymer is obtained by including an emulsifier represented by the following formula (1), wherein the acrylate-conjugated diene-aromatic vinyl- It can be used as an impact modifier mixed with lactic acid to enhance brittleness:

[Chemical Formula 1]

Wherein R is alkyl having from 12 to 14 carbon atoms, n is an integer from 4 to 8, and m is 1 or 2.

The acrylate-conjugated diene-aromatic vinyl copolymer is obtained by copolymerizing 10 to 30% by weight of a (meth) acrylic acid alkyl ester monomer and 10 to 30% by weight of a polyethylene glycol monomer in 50 to 80% by weight of a conjugated diene rubber- Which is obtained by copolymerizing 50 to 80% by weight of an impact modifier for a poly (lactic acid) resin using 10 to 30% by weight of a (meth) acrylic acid alkyl ester monomer and 10 to 30% by weight of a polyethylene glycol comonomer in a butadiene rubber latex , And it is particularly preferable that the conjugated diene rubber polymer core has an average particle diameter within a range of 1,500 to 3,500 angstroms.

The conjugated diene-based rubber polymer core used in the graft copolymerization may be prepared from a monomer selected from the group consisting of butadiene, isoprene, chloroisoprene and a mixture of two or more thereof. Of these, butadiene is preferably used. The conjugated diene-based rubber polymer core may preferably be produced by emulsion polymerization.

In the graft copolymerization, the conjugated diene-based rubber polymer core contains the total amount of reactants participating in copolymerization, that is, the total amount of the conjugated diene rubber polymer core, (meth) acrylic acid alkyl ester monomer, and polyethylene glycol monomer Is used in an amount within a range of 50 to 80% by weight, preferably 55 to 75% by weight, more preferably 60 to 70% by weight based on the total amount of the acrylate-conjugated diene- When the aromatic vinyl-based copolymer is mixed with the poly (lactic acid) resin, the impact strength is improved and the compatibility with the poly (lactic acid) resin is improved so that the dispersion in the poly (lactic acid) resin can be performed well.

The (meth) acrylic acid alkyl ester monomers used in the graft copolymerization are used collectively as the alkyl acrylate monomer and the methacrylate alkyl ester monomer, preferably alkyl acrylate or alkyl methacrylate, More preferably, it may be selected from the group consisting of methyl methacrylate, n-butyl methacrylate, benzyl methacrylate, lauryl methacrylate, stearyl methacrylate, and mixtures of two or more thereof. Methyl methacrylate is preferably used.

The (meth) acrylic acid alkyl ester monomer is used in an amount within a range of 10 to 30% by weight, preferably 10 to 20% by weight based on the total amount of the reactants. The acrylate-conjugated diene- When the aromatic vinyl-based copolymer is mixed with the poly (lactic acid) resin, the compatibility with the poly (lactic acid) resin is improved, the dispersion in the poly (lactic acid) resin can be performed well, and the impact strength can be improved. Particularly, when the amount of the (meth) acrylic acid alkyl ester monomer is less than 10% by weight, compatibility may be poor and dispersion may be problematic. On the contrary, when the amount is more than 30% by weight, the proportion of the polyethylene glycol- There is a problem that the strength is lowered.

The polyethylene glycol-based monomer used in the graft copolymer is _{A- (CH 2 -CH 2 -O)} n -A, A- (CH 2 -CH 2 -O) n -H, A- (CH 2 -CH ₂ -O) _n -CH ₃ , wherein A is a monomer having a double bond such as acrylate or methacrylate, n is an integer of 3 to 14, and a weight average molecular weight (Mn) 10,000. The polyethylene glycol monomer is preferably selected from the group consisting of polyethylene glycol acrylate, poly (ethylene glycol) methacrylate, poly (ethylene glycol) diacrylate, Poly (propylene glycol) acrylate, and mixtures of two or more thereof. However, the present invention is not intended to be limited thereto.

The polyethylene glycol monomer is used in an amount within a range of 10 to 30% by weight, preferably 10 to 20% by weight, based on the total amount of the reactants, as an impact modifier. The acrylate-conjugated diene- When the copolymer is mixed with the poly (lactic acid) resin, the compatibility with the poly (lactic acid) resin is improved so that the dispersion in the poly (lactic acid) resin can be performed well and the impact strength can be improved.

In order to accomplish the above object, the present invention also provides a method for producing an acrylate-conjugated diene-aromatic vinyl copolymer, comprising: (a) preparing a core to produce a conjugated diene-based rubber polymer core; And (b) 10 to 30% by weight of a (meth) acrylic acid alkyl ester monomer and 10 to 30% by weight of a polyethylene glycol monomer in the presence of 50 to 80% by weight of a conjugated diene rubber polymer core obtained in the core preparation step Graft copolymerization to obtain an acrylate-conjugated diene-aromatic vinyl-based copolymer having a core-shell structure, wherein the inner layer constituting the core or the outer layer constituting the shell Or both of the inner layer and the outer layer are each obtained by including an emulsifier represented by the following formula (1).

[Chemical Formula 1]

Wherein R is alkyl having from 12 to 14 carbon atoms, n is an integer from 4 to 8, and m is 1 or 2.

The core preparation step (a) may be a step of preparing a conjugated diene rubber polymer core, preferably from monomers selected from the group consisting of butadiene, isoprene, chloroisoprene, and a mixture of two or more thereof, Butadiene can be preferably used, and the conjugated diene rubber polymer core can be preferably produced by emulsion polymerization.

The average particle diameter of the conjugated diene rubber polymer is preferably in the range of 1,500 to 3,500 angstroms, preferably 2,000 to 3,000 angstroms, and the impact obtained by graft copolymerization using the conjugated diene rubber polymer within this range as a core When the acrylate-conjugated diene-aromatic vinyl copolymer as the reinforcing agent is mixed with the poly (lactic acid) resin, the impact strength improving effect is excellent, and when the average particle diameter of the conjugated diene rubber polymer core is less than 1,500 angstroms, There may be a problem that the effect becomes insufficient. On the other hand, when the average particle diameter is more than 3,500 ANGSTROM, the reaction time for the preparation thereof is long and it is difficult to secure the stability of the latex.

The copolymerization step (b) is a step of copolymerizing 10 to 30% by weight of a (meth) acrylic acid alkyl ester monomer and 10 to 30% by weight of a polyethylene glycol monomer in the presence of 50 to 80% by weight of a conjugated diene- , And graft copolymerization is carried out to obtain an acrylate-conjugated diene-aromatic vinyl copolymer having a core-shell structure. In the above, each monomer and its content are the same as or similar to those described above , And repeated descriptions are avoided. The graft copolymerization is preferably carried out at a temperature within the range of 40 to 60 ° C, preferably 50 to 60 ° C for 3 to 5 hours, preferably 4 to 5 hours, more preferably 4.5 hours.

The polylactic acid resin composition of the present invention is characterized by containing 10 to 30% by weight of the acrylate-conjugated diene-aromatic vinyl copolymer and 70 to 90% by weight of the polylactic acid resin.

The poly (lactic acid) resin composition may further contain additives such as a flame retardant, a lubricant, an antioxidant, a light stabilizer, a reaction catalyst, a releasing agent, a pigment, an antistatic agent, a conductivity imparting agent, an EMI shielding agent, An antistatic agent, an antimicrobial agent, a processing aid, a metal deactivator, a suppressing agent, a fluorine antistatic agent, an inorganic filler, a glass fiber, an antiwear friction agent, a coupling agent and a mixture of two or more thereof.

The method of melt-kneading and processing the polylactic acid resin, the impact modifier, and other additives is not particularly limited, but specific examples thereof include a primary mixer in a super mixer, and a conventional mixer such as a twin-screw extruder, a single screw extruder, a roll mill, a kneader or a Bambari mixer Kneading using one of blending machines, obtaining pellets by a pelletizer, and then sufficiently drying the pellets with a dehumidifying dryer or a hot-air dryer, followed by injection molding to obtain a final molded article.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Changes and modifications may fall within the scope of the appended claims.

[Example]

Example 1

Preparation of conjugated diene rubber polymer

The weight percentages of the following compounds are based on 100 weight percent of the monomer mixture used for the preparation of the conjugated diene rubber polymer, and parts by weight are based on 100 parts by weight of the monomer mixture.

To a 120 L high-pressure polymerization vessel equipped with a stirrer, 150 parts by weight of ion exchange water, 0.5 part by weight of sodium sulfate as an additive, 1.0 part by weight of potassium oleate, 0.0048 part by weight of ethylenediaminetetra sodium acetate, 0.003 part by weight of ferrous sulfate, 0.02 part by weight of sulfoxyacid and 0.2 part by weight of diisopropylbenzene hydroperoxide were initially charged.

100% by weight of butadiene was added thereto and polymerization was carried out at 70 DEG C for 18 hours to obtain a conjugated diene rubber polymer core having an average particle diameter of 2,000 ANGSTROM, and the final polymerization conversion ratio thereof was 95%.

Preparation of acrylate-conjugated diene-aromatic vinyl copolymer

The weight percentages of the following compounds are based on 100 weight percent of the monomer mixture used for the preparation of the acrylate-conjugated diene-aromatic vinyl-based copolymer, and parts by weight are based on 100 parts by weight of the monomer mixture.

60% by weight (based on solid content) of the resultant conjugated diene-based rubber polymer core was charged into a closed reactor and then charged with nitrogen. To this, 0.05 part by weight of ethylenediaminetetra sodium acetate, 0.009 part by weight of ferrous sulfate, 0.05 part by weight of aldehyde sulfoxylic acid was added and then 20 parts by weight of methyl methacrylate and 20 parts by weight of polyethylene glycol methacrylate (poly (ethylene glycol) methacrylate), 2.0 parts by weight of sodium salt of polyoxyethylene alkyl ether phosphate, 20 parts by weight of exchanged water and 0.07 parts by weight of t-butyl hydroperoxide were added at 60 캜 for 3 hours, and then further polymerized for 1.5 hours.

The prepared graft copolymer on the latex was solidified with hydrochloric acid to separate the polymer and water, and then dehydrated and dried to obtain a powdery acrylate-conjugated diene-aromatic vinyl copolymer.

Preparation of poly (lactic acid) resin composition

80% by weight of a polylactic acid resin and 20% by weight of an acrylate-conjugated diene-aromatic vinyl copolymer obtained by the above method were mixed and melted and kneaded at 250 DEG C using an extruder to obtain a pelletized polylactic acid resin composition Respectively. The obtained pellets were subjected to T-die extrusion at a die temperature of 220 DEG C to prepare a sheet having a thickness of 0.5 mm.

Example 2

A conjugated diene rubber polymer core having an average particle diameter of 2,000 Å was used in the production of the acrylate-conjugated diene-aromatic vinyl copolymer, and 3.0 parts by weight of the sodium salt of polyoxyethylene alkyl ether phosphate in the shell polymerization step The procedure of Example 1 was otherwise repeated.

Example 3

A conjugated diene rubber polymer core having an average particle diameter of 2,000 ANGSTROM was used in the production of the acrylate-conjugated diene-aromatic vinyl copolymer. In the conjugated diene rubber production step, sodium oleate of polyoxyethyleneglycol alkyl ether phosphate The procedure of Example 1 was repeated except that 1.0 part by weight of a salt was used and 2.0 parts by weight of sodium salt of polyoxyethyleneglycol alkyl ether phosphate was used in the shell polymerization step.

Comparative Example 1

Acrylate-conjugated diene-aromatic vinyl copolymer was not used and only 100 wt% of polylactic acid resin was used.

Comparative Example 2

Acrylate-conjugated diene-aromatic vinyl copolymer was used in place of the sodium salt of the polyoxyethylene alkyl ether phosphate in the shell polymerization step of Example 1 Except that 2.0 parts by weight of potassium oleate was used.

Comparative Example 3

A conjugated diene rubber polymer core having an average particle diameter of 2,000 ANGSTROM was used in the production of the acrylate-conjugated diene-aromatic vinyl copolymer. In the conjugated diene rubber production step, sodium oleate of polyoxyethyleneglycol alkyl ether phosphate The procedure of Example 1 was repeated except that 1.0 part by weight of a salt was used.

Comparative Example 4

Acrylate-conjugated diene-aromatic vinyl copolymer, a conjugated diene-based rubber polymer core having an average particle diameter of 2,000 Å was used. In the shell polymerization step, 1.0 part by weight of a sodium salt of polyoxyethylene alkyl ether phosphate and 1.0 part by weight of potassium oleate Except that 1.0 part by weight of a polyisocyanate compound was used.

Comparative Example 5

A conjugated diene rubber polymer core having an average particle diameter of 2,000 ANGSTROM was used in the preparation of the acrylate-conjugated diene-aromatic vinyl copolymer, and 1.0 part by weight of potassium oleate was used in the preparation of the conjugated diene rubber. Except that 1.0 part by weight of sodium salt of oxyethylenic alkyl ether phosphate and 1.0 part by weight of potassium oleate were used.

Comparative Example 6

In the preparation of the acrylate-conjugated diene-aromatic vinyl copolymer, a conjugated diene-based rubber polymer core having an average particle diameter of 2,000 Å was used, and 5.0 parts by weight of a sodium salt of polyoxyethylene alkyl ether phosphate in the shell polymerization step was used in a large amount The procedure of Example 1 was otherwise repeated.

[Test Example]

The physical properties of the polylactic acid resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 6 were evaluated as follows, and the results are shown in Table 1 below.

Izod Impact Strength: Evaluation was made on 1/8 inch notched specimens by ASTM D256 test method.

Example 1 Example 2 Example 3 article

castle core BD (% by weight) 100 100 100 OLK (% by weight) 1.0 1.0 - PAP (% by weight) - - 1.0 Shell Core (wt%) 60 60 60 MMA (% by weight) 20 20 20 PEGMA (wt%) 20 20 20 PAP (% by weight) 2.0 3.0 2.0 OLK (% by weight) - - - Average particle diameter (A) 2,000 2,000 2,000 MBS usage (% by weight) 20 20 20  PLA usage (wt%) 80 80 80 Lubricant (% by weight) 0.5 0.5 0.5 Stabilizer (% by weight) 0.5 0.5 0.5 Impact strength
Izod (1/8 ", kg · cm / cm) 50.0 50.0 50.0 BD = butadiene rubber,
MMA = methyl methacrylate,
PEGMA = polyethylene glycol methacrylate,
MBS = methyl methacrylate-butadiene-styrene resin (acrylate-conjugated diene-aromatic vinyl copolymer)
PLA = poly lactic acid resin
PAP = sodium salt of polyoxyethylene alkyl ether phosphate

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 article

castle core BD (% by weight) - 100 100 100 100 100 OLK (% by weight) - 1.0 - 1.0 - 1.0 PAP (% by weight) - - 1.0 - 1.0 - Shell Core (wt%) - 60 60 60 60 60 MMA (% by weight) - 20 20 20 20 20 PEGMA (wt%) - 20 20 20 20 20 PAP (% by weight) - - - 1.0 1.0 5.0 OLK (% by weight) - 2.0 2.0 1.0 1.0 - Average particle diameter (A) - 2,000 2,000 2,000 2,000 2,000 MBS usage (% by weight) - 20 20 20 20 20  PLA usage (wt%) 100 80 80 80 80 80 Lubricant (% by weight) 0.5 0.5 0.5 0.5 0.5 0.5 Stabilizer (% by weight) 0.5 0.5 0.5 0.5 0.5 0.5 Impact strength
Izod (1/8 ", kg · cm / cm) 3.2 43.0 43.5 45.6 45.3 X BD = butadiene rubber,
MMA = methyl methacrylate,
PEGMA = polyethylene glycol methacrylate,
MBS = methyl methacrylate-butadiene-styrene resin (acrylate-conjugated diene-aromatic vinyl copolymer)
PLA = poly lactic acid resin
PAP = sodium salt of polyoxyethylene alkyl ether phosphate

As shown in Tables 1 and 2, it was confirmed that Examples 1 to 3 including the acrylate-conjugated diene-aromatic vinyl copolymer according to the present invention had an excellent impact strength as compared with Comparative Examples 1 to 6 .

On the other hand, in Comparative Example 2, it was found that when an impact modifier in which PA was not added to shell polymerization during the production of an acrylate-conjugated diene-aromatic vinyl copolymer was used for polylactic acid, . In addition, in Comparative Example 3, it was confirmed that when PAP was used for polymerizing the rubber polymer core without being used for shell polymerization, it was not effective in improving the Izod impact strength of the poly (lactic acid) resin composition.

In Comparative Example 3, when potassium oleate and PAP were used together in the shell polymerization, 1.0 part by weight of PAP was less in content and sufficient entanglement with the poly (lactic acid) resin did not occur, It was found that the addition of PAP to the rubber polymer core did not improve the impact strength of the polylactic acid resin even when the total weight was increased and that the addition of the PAP emulsifier to the shell polymer portion had an effect of improving the impact strength of the polylactic acid resin composition I could.

In Comparative Example 6, when a large amount of the PAP emulsifier was introduced into the shell polymerization portion, the graft copolymer on the latex was not phase-separated in the step of solidifying the graft copolymer on the latex with hydrochloric acid. Thus, the powdery acrolein-conjugated diene- Copolymer was not obtained.

Claims (9)

(1) a conjugated diene-based rubber polymer core; And
(2) a shell obtained by graft copolymerizing 50 to 75% by weight of the conjugated diene rubber polymer core with 10 to 30% by weight of a (meth) acrylic acid alkyl ester monomer and 10 to 30% by weight of a polyethylene glycol monomer, ,
Wherein either one of the inner layer constituting the core or the outer layer constituting the shell or both the inner layer and the outer layer are each obtained by including an emulsifier represented by the following Chemical Formula 1 wherein the conjugated diene rubber polymer core is 1,500- Wherein the average particle diameter of the copolymer is in the range of 3,000 to 3,000 ANGSTROM. The acrylate-conjugated diene-aromatic vinyl-
[Chemical Formula 1]

Wherein R is alkyl having from 12 to 14 carbon atoms, n is an integer from 4 to 8, and m is 1 or 2. The method according to claim 1,
Wherein the conjugated diene-based rubber polymer core is prepared from a monomer having at least one member selected from the group consisting of butadiene, isoprene and chlorisoprene, and the emulsifier represented by the formula 1 is added to the acrylate-conjugated diene- Is contained in the range of 1.0 to 4.0 wt% based on the total weight of the total monomers constituting the shell. The method according to claim 1,
Wherein the (meth) acrylic acid alkyl ester monomer is at least one member selected from the group consisting of methyl methacrylate, n-butyl methacrylate, benzyl methacrylate, lauryl methacrylate and stearyl methacrylate. Acrylate-conjugated diene-aromatic vinyl-based copolymer. The method according to claim 1,
The polyethylene glycol-based monomer is _{A- (CH 2 -CH 2 -O)} n -A, A- (CH 2 -CH 2 -O) n -H, A- (CH 2 -CH 2 -O) n -CH ₃ , wherein A is a carbon-carbon double bond, n is an integer of 3 to 14, and a weight average molecular weight (Mn) is 300 to 10,000. Rate-conjugated diene-aromatic vinyl-based copolymer. 5. The method of claim 4,
Wherein the polyethylene glycol monomer is selected from the group consisting of polyethylene glycol acrylate, poly (ethylene glycol) methacrylate, poly (ethylene glycol) diacrylate, and polypropylene glycol Acrylate, and poly (propylene glycol) acrylate. 2. The acrylate-conjugated diene-aromatic vinyl copolymer according to claim 1, wherein the acrylate-conjugated diene-aromatic vinyl copolymer is at least one selected from the group consisting of poly (propylene glycol) acrylate. (a) a core-making step of producing a conjugated diene-based rubber polymer core; And
(b) 10 to 30% by weight of a (meth) acrylic acid alkyl ester monomer and 10 to 30% by weight of a polyethylene glycol monomer in the presence of 50 to 75% by weight of a conjugated diene rubber polymer core obtained in the core production step, Copolymerization step to obtain an acrylate-conjugated diene-aromatic vinyl-based copolymer having a core-shell structure;
, ≪ / RTI &
Wherein either one of the inner layer constituting the core or the outer layer constituting the shell, or both of the inner layer and the outer layer are obtained by including an emulsifier represented by the following general formula (1): ???????? Acrylate-conjugated diene- Method of preparing the coalescent:
[Chemical Formula 1]

Wherein R is alkyl having from 12 to 14 carbon atoms, n is an integer from 4 to 8, and m is 1 or 2. The method according to claim 6,
Wherein the graft copolymerization reaction is carried out at a temperature within a range of 40 to 60 ° C for 3 to 5 hours in the copolymerization step. 10. A poly (lactic acid) resin composition, comprising 10 to 30% by weight of an acrylate-conjugated diene-aromatic vinyl copolymer according to any one of claims 1 to 5 and 70 to 90% by weight of a poly (lactic acid) resin. 9. The method of claim 8,
Wherein the polylactic acid resin composition is selected from the group consisting of a flame retardant, a lubricant, an antioxidant, a light stabilizer, a reaction catalyst, a releasing agent, a pigment, an antistatic agent, a conductivity imparting agent, an electromagnetic interference shielding agent, , A metal deactivator, a suppressing agent, a fluorine-based antistatic agent, an inorganic filler, a glass fiber, an anti-friction wear-inhibiting agent, a coupling agent and a mixture of two or more thereof.