KR20180033653A - MBS impact modifier, polyvinyl chloride resin composition comprising the same - Google Patents

Abstract

The present invention relates to an MBS impact modifier, and to a polyvinyl chloride resin composition comprising the same, and more particularly, to an MBS impact modifier, which is formed by graft-polymerizing a conjugated diene rubber core with inner and outer shells, and to a polyvinyl chloride resin composition comprising the same. Since the MBS impact modifier uses an aromatic acrylic monomer having an aromatic ring having a high refractive index during manufacture of the outer shell, when the MBS impact modifier is used as an additive for the polyvinyl chloride resin, compatibility with the resin is excellent to improve the workability and to increase the impact strength and transparency of resin molded articles.

Description

MBS impact modifier and a polyvinyl chloride resin composition containing the impact modifier,

The present invention relates to an MBS impact modifier and a polyvinyl chloride resin composition containing the MBS impact modifier, which enables production of a molded article having excellent transparency.

Polyvinyl chloride (PVC) resins are general-purpose resins widely used in various fields because of their excellent physical and chemical properties. However, since the processing temperature of the polyvinyl chloride resin is close to the pyrolysis temperature, the moldable temperature range is narrow, the melt viscosity is high and the fluidity is low, so that the polyvinyl chloride resin is adhered to the surface of the processing equipment during processing to form carbide, And the like.

In order to improve the processability of the conventional polyvinyl chloride resin, there has been proposed a process for producing a methyl methacrylate-butadiene-ethylenic unsaturated aromatic monomer (MMA-butadiene-styrene) (hereinafter referred to as MBS) graft Various attempts have been made such as changing the monomer composition of the copolymer, controlling the molecular weight, changing the structure, or changing the graft polymerization method.

However, such attempts have a limitation in improving the workability such as bulk density, fluidity, and caking characteristics of the polyvinyl chloride resin, and even if the workability is improved, there is a problem that the physical properties such as impact strength or transparency are lowered .

Improving workability and transparency usually reduces the impact strength. By introducing a monomer having a high refractive index, it is desired to improve workability and transparency without lowering the impact strength.

Usually, the refractive index of the polyvinyl chloride resin is as high as 1.5390, and the polymethyl methacrylate resins are as low as 1.45 to 1.49. However, the polymethyl methacrylate resins have a limitation in reducing the content because they have a large effect on workability and impact strength. In order to improve the refractive index, a large amount of polystyrene is used, but transparency is improved, but workability and impact strength are lowered.

Korean Patent Publication No. 2008-0049345 (2008.06.04), "Thermoplastic resin composition and molded article using the same" Korean Patent Registration No. 10-0837091 (2008.06.04), "Acrylic rubber impact stiffener having improved impact resistance and weather resistance and vinyl chloride resin containing the same"

As a result of various studies to solve the above problem, the present inventors have found that, in an impact modifier having a core-shell structure, the conjugated diene rubber core is grafted to form an inner shell and an outer shell, It has been found that the processability and transparency can be improved without lowering the impact strength in the production of polyvinyl chloride resin by using the acrylic monomer having a high aromatic ring, thereby completing the present invention.

Accordingly, an object of the present invention is to provide an MBS impact modifier wherein the conjugated diene rubber core is sequentially grafted to the inner shell and the outer shell, respectively.

Another object of the present invention is to provide a polyvinyl chloride resin composition having improved transparency including the MBS impact modifier.

In order to achieve the above object, the present invention relates to a composition comprising 100% by weight of the total of monomers

65 to 79% by weight of a conjugated diene-based rubber core in which a conjugated diene-based monomer, an aromatic vinyl monomer and a crosslinkable monomer are copolymerized;

8-15 wt% of a first graft shell surrounding the core, wherein methyl methacrylate and polyalkylene glycol monomer are grafted; And

And 11 to 25 wt% of a second graft shell surrounding the first graft shell and having an aromatic vinyl monomer and an aromatic acrylic monomer grafted thereon.

Wherein the conjugated diene rubber core is copolymerized with 46 to 59 wt% of a conjugated diene monomer, 15 to 20 wt% of an aromatic vinyl monomer, and 0.1 to 5 wt% of a crosslinkable monomer.

The first graft shell is characterized in that 8 to 15% by weight of methyl methacrylate and 0.05 to 5% by weight of polyalkylene glycol monomer are grafted.

The second graft shell is characterized in that 10 to 20% by weight of the aromatic vinyl monomer and 1 to 9% by weight of the aromatic acrylic monomer are grafted.

In this case, the MBS impact modifier has an average particle diameter of 160 to 300 nm.

The present invention also provides a polyvinyl chloride resin composition comprising the MBS impact modifier.

The MBS impact modifier according to the present invention is excellent in compatibility with the resin when used as an additive for a polyvinyl chloride resin by copolymerizing an acrylate monomer having an aromatic ring having a high refractive index in an outer shell, Can be increased.

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

MBS system Impact modifier

In the present invention, an impact modifier capable of increasing or decreasing the impact strength while improving transparency and processability by introducing a monomer having a high refractive index into an MBS impact modifier used for a polyvinyl chloride resin is proposed.

Specifically, the MBS impact modifier includes a conjugated diene rubber core, a first graft shell and a second graft shell sequentially surrounding the conjugated diene rubber core.

core

The conjugated diene rubber core is obtained through polymerization of a conjugated diene monomer. The polybutadiene polymerized with butadiene, which is a typical monomer, has a refractive index of 1.5170 and a low refractive index. The conjugated diene rubber core is crosslinked with an aromatic vinyl monomer as a comonomer together with the conjugated diene monomer The monomers are prepared by copolymerization.

First, the conjugated diene monomer is not particularly limited in the present invention, but may be, for example, butadiene, isoprene, chloroisoprene, etc., butadiene is preferably used.

The content of the conjugated diene monomer is used in an amount of 46 to 59% by weight, preferably 48 to 55% by weight based on 100% by weight of the total amount of the monomers. If the content is less than the above range, the rubber properties deteriorate to lower the impact resistance, which is difficult to use as a rubber core. On the other hand, when the content is in excess of the above range, the refractive index is lowered.

Further, the aromatic vinyl monomer has a high refractive index and can improve the transparency of the polyvinyl chloride resin. Specific examples of the aromatic vinyl monomer include styrene, alpha-methylstyrene, o-ethylstyrene, p-ethylstyrene, vinyltoluene, and combinations thereof, preferably styrene.

The aromatic vinyl monomer content is used in an amount of 15 to 20% by weight, preferably 16 to 19% by weight based on 100% by weight of the total amount of the monomers. If the content is less than the above range, the effect of increasing the refractive index can not be expected. On the contrary, when the content exceeds the above range, the Tg increases to increase the melting time and increase the melt pressure. do.

Also, the crosslinkable monomer may be selected from the group consisting of divinylbenzene, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, It is possible to use at least one member selected from the group consisting of allyl methacrylate, trimethylolpropane triacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, and combinations thereof, preferably allyl methacrylate Lt; / RTI >

The crosslinking monomer is preferably contained in an amount of 0.1 to 5% by weight, preferably 0.5 to 3% by weight based on 100% by weight of the total amount of the monomers. If the content is less than the above range, the grafting rate of the first grafting shell is low, which affects the workability and the impact strength. On the other hand, if the content exceeds the above range, the rubber core exhibits a brittle characteristic, .

At this time, the conjugated diene rubber core is spherical particles having an average particle diameter of 150 to 295 nm, preferably 180 to 280 nm in consideration of rubber properties and compatibility with the poly (lactic acid) resin.

The conjugated diene rubber core having such a composition is contained in an amount of 65 to 79% by weight in 100% by weight of the MBS impact modifier. If the content is less than the above range, there may occur a problem that the impact property is low due to a low rubber property to absorb the impact. On the contrary, when the content is above the range, the shell content is relatively low, Resulting in poor processing and dispersibility.

In the MBS impact modifier according to the present invention, the rubber core is sequentially grafted to the inner shell and the outer shell. These inner shells and outer shells are formed in order to improve the workability of the MBS-based impact modifier and improve the workability of the polyvinyl chloride resin to increase the impact resistance and increase the transparency. Hereinafter, the inner shell is referred to as a first graft shell and the outer shell is referred to as a second graft shell.

The first grafted shell is prepared through copolymerization through fine aggregation of methyl methacrylate and polyalkylene glycol monomer.

Herein, the term "microagglomeration " refers to raising the particle size by fine aggregation occurring simultaneously with graft polymerization by a salt added with a monomer unless otherwise specified.

Specifically, the first graft shell is formed by using methyl methacrylate as a main monomer, and using other comonomers so that the graft ratio and the rubber core can be evenly wrapped. More specifically, 4 to 15% by weight, preferably 7 to 14% by weight, and 0.05 to 5% by weight, based on 100% by weight of the total of the monomers constituting the MBS impact modifier are methyl methacrylate, , Preferably 0.1 to 3 wt%, based on the total weight of the composition.

Methyl methacrylate is used for increasing the impact strength and compatibility, and this effect can not be secured when the content is out of the above range.

In addition, the polyalkylene glycol-based monomer is used to enhance the grafting reaction with the monomer constituting the subsequent second graft shell and to form the second graft shell so as to surround the first graft shell well. Therefore, if the content is outside the above range, such effects can not be obtained.

Examples of usable polyalkylene glycol monomers include poly (ethylene glycol) monoacrylate, poly (ethylene glycol) monomethacrylate, poly (propylene glycol) monoacrylate, poly (propylene glycol) monomethacrylate, poly (Propylene glycol) diacrylate, methoxypoly (ethylene glycol) monoacrylate, methoxypoly (ethylene glycol) diacrylate, poly (Ethylene glycol) monoacrylate, phenoxypoly (ethylene glycol) monoacrylate, methoxypoly (propylene glycol) monoacrylate, methoxypoly (propylene glycol) monomethacrylate, phenoxypoly Monomethacrylate, phenoxypoly (ethylene propylene) monoacrylate, and phenoxypoly (ethylene propylene) And monomethacrylate, and polyethylene glycol diacrylate is preferably used.

The polyalkylene glycol monomer may have a number average molecular weight (Mn) of 200 to 10,000 g / mol or 200 to 1,000 g / mol as a polymer.

The content of the first graft shell is 8 to 15% by weight based on 100% by weight of the MBS impact modifier. If the content of the first graft shell is less than the above range, the impact strength of the polyvinyl chloride resin may be lowered. On the contrary, if the content exceeds the above range, the transparency may be lowered. use.

The second graft shell is formed by wrapping a first graft shell, which is an inner shell, as an outer shell, and is made of a material for improving transparency and processability and improving compatibility with a polyvinyl chloride resin.

The second grafted shell preferably comprises an aromatic ring having a high impact strength and a high refractive index. Specifically, the second graft shell preferably comprises 10 to 20% by weight of an aromatic vinyl monomer and 1 to 9% by weight of an aromatic acrylic monomer, By graft polymerization.

As the aromatic vinyl monomer, the above-mentioned materials may be used, and styrene is preferably used.

Particularly, the aromatic acrylic monomer used in the second graft shell simultaneously contains an acrylic functional group having excellent processability together with an aromatic ring having an excellent refractive index, so that not only the transparency of the MBS impact modifier is increased but also the polyvinyl chloride resin and the processability . As the aromatic acrylic monomer, phenyl acrylate, phenyl methacrylate, or both are used.

Usually, the refractive index of the polyvinyl chloride resin is 1.54, the refractive index of polymethyl methacrylate is 1.49, the refractive index of polystyrene is 1.55, and the refractive index of polyphenyl methacrylate is 1.57, and when the aromatic ring is included, the refractive index is further increased . However, in consideration of the impact strength and compatibility with polyvinyl chloride resin (i.e., workability), it is preferable to use both polystyrene or polyphenyl methacrylate alone, It can satisfy all physical properties such as compatibility and processability at the same time.

When phenylmethacrylate (Example 2) as a monomer having an aromatic ring and cyclohexyl methacrylate (Comparative Example 3) as a monomer having an aliphatic ring are used respectively in the preferred embodiment and the comparative example of the present invention, When the monomer was used, the haze was 3.1%, which is lower than that of the monomer having an aliphatic ring (4.8). Thus, transparency is improved.

The content of the second graft shell is 11 to 25% by weight in 100% by weight of the MBS impact modifier. If the content of the second Graftshell is less than the above range, the transparency of the polyvinyl chloride resin may be lowered. On the contrary, if the content exceeds the above range, the transparency increases but the impact strength may decrease. Use properly within.

The MBS impact modifier containing the above-mentioned composition can be used as any method capable of forming a core-shell structure through grafting.

Specifically, the MBS impact modifier according to the present invention comprises

(S1) copolymerizing a conjugated diene monomer, an aromatic vinyl monomer and a crosslinkable monomer to prepare a rubber core;

A step (S2) of forming a first graft shell by graft-polymerizing methyl methacrylate and a polyalkylene glycol monomer on the rubber core; And

And a step (S3) of forming a second graft shell by graft-polymerizing an aromatic vinyl monomer and an aromatic acrylic monomer to the first graft shell.

Each step will be described in detail below.

First, a conjugated diene monomer, an aromatic vinyl monomer and a crosslinkable monomer are copolymerized to prepare a rubber core (S1).

The production of the conjugated diene rubber core is not particularly limited in the present invention, and may be carried out by various methods such as emulsion polymerization, bulk polymerization, suspension polymerization, solution polymerization, etc., preferably emulsion polymerization.

Upon emulsion polymerization, the monomer may further contain an initiator, an emulsifier, and additives commonly known in the art such as a molecular weight regulator, an activator, a redox catalyst, and ionized water.

 As the initiator, a water-soluble initiator can be used, and inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, hydrogen peroxide and the like; t-butyl peroxide, cumene hydroperoxide, p-menthol hydroperoxide, di-t-butyl peroxide, t-butyl cumyl peroxide, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide Organic peroxides such as oxides, 3,5,5-trimethylhexanol peroxide, t-butyl peroxyisobutyrate; Nitrogen compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, and azobisisobutyric acid (butyl acid) methyl. These initiators are used in an amount of 0.03 to 0.2 part by weight based on 100 parts by weight of the total monomers.

The emulsifier may be selected from the group consisting of an anionic emulsifier, a cationic emulsifier and a nonionic emulsifier, and is not particularly limited in the present invention. Examples of the emulsifier include sulfonate, carboxylate, succinate, sulfosuccinate and metal salts thereof, such as alkylbenzenesulfonic acid, sodium alkylbenzenesulfonate, alkylsulfonic acid, sodium alkylsulfonate, sodium poly Anionic surfactants commonly used in emulsion polymerization such as sodium stearate, oxyethylene nonylphenyl ether sulfonate, sodium stearate, sodium dodecyl sulfate, sodium lauryl sulfate, sodium dodecyl sulfosuccinate, potassium oleate, Emulsifiers; A cationic emulsifier to which an amine halide, an alkylammonium salt, an alkylpyridinium salt or the like is bonded as a functional group of a higher aliphatic hydrocarbon; And nonionic emulsifiers such as polyvinyl alcohol and polyoxyethylene nonylphenyl. These emulsifiers are not limited to these emulsifiers. Such an emulsifier may be used in an amount of 0.1 part by weight to 5 parts by weight based on 100 parts by weight of the monomer mixture.

The molecular weight regulator is not particularly limited, and examples thereof include mercaptans such as a-methylstyrene dimer, t-octenyl mercaptan, n-dodecyl mercaptan and octyl mercaptan; Halogenated hydrocarbons such as carbon tetrachloride, methylene chloride, and methylene bromide; Containing sulfur compounds such as tetraethyldiallyldisulfide, dipentamethylenediuramydisulfide, and diisopropylkantogen disulfide, and may be used in an amount of 0.1 part by weight to 3 parts by weight based on 100 parts by weight of the monomer mixture.

Activators include, but are not limited to, at least one selected from sodium hydrogensulfate, sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, lactose, dextrose, sodium lorolene, and sodium sulfate. Based on 100 parts by weight of the total of the monomers, within the range of 0.01 to 0.15 parts by weight.

The redox catalyst may be, for example, sodium formaldehyde sulfoxylate, ferrous sulfate, disodium ethylenediamine tetraacetate, and cupric sulfate, and may be used in an amount of 0.01 to 0.1 parts by weight per 100 parts by weight of the monomer mixture. Parts by weight.

The polymerization may be carried out at 40 to 80 ° C for 2 to 12 hours.

Next, a methyl methacrylate and a polyalkylene glycol-based monomer are graft-polymerized on the rubber core to form a first graft shell (S2);

The primary graft polymerization for internal shell formation is as described in the emulsion polymerization described above. For example, it is preferable that the initiator, emulsifier and various additives necessary for emulsion polymerization are added and the reaction is carried out at a temperature of 40 to 60 DEG C for 3 to 5 hours. In this case, various compositions and reaction conditions are not particularly limited in the present invention, and are well known in the art.

Next, an MBS impact modifier having a core-shell structure is prepared through a step (S3) of forming a second graft shell by grafting-polymerizing an aromatic vinyl monomer and an aromatic acrylic monomer onto the composite obtained in the step (S2) (S3).

The secondary graft polymerization for the formation of the outer shell follows the procedure described in the emulsion polymerization described above.

The MBS-based impact modifier prepared through the above steps is agglomerated by adding 0.2 to 8 parts by weight of sulfuric acid based on 100 parts by weight of latex at a temperature of 40 to 60 ° C, and then dried to prepare powder.

Poly polyvinyl chloride  Resin composition

The thus prepared MBS impact modifier has a relatively high average particle size of 160 to 300 nm, preferably 180 to 250 nm, a refractive index of 1.5300 to 1.5400, a haze of 3.1% or less and a refractive index of 1.5390 Based resin is used as an additive in the processing step of the resin to improve the processability and the produced molded article has high impact strength and transparency.

Specifically, the polyvinyl chloride resin composition according to the present invention is added in an amount of 0.1 to 30 parts by weight as an MBS impact modifier to 100 parts by weight of a vinyl chloride resin, and various molded articles are produced through various molding processes. The content of the MBS-based impact modifier is intended to improve the impact resistance and the surface condition of the finally obtained molded article. If the content of the impact modifier is less than the above range, improvement in impact resistance can not be expected. If the content exceeds the above range, Therefore, it should be adjusted within the above range.

If necessary, various additives commonly used in this field may be further included. Examples of the additive include a processing aid, a heat stabilizer, a lubricant, a plasticizer, a UV stabilizer, a flame retardant, a colorant, a filler, a flame retardant, an antibacterial agent, a releasing agent, an antioxidant, a compatibilizing agent, a colorant, a surfactant, a nucleating agent, May be added, and they may be used alone or in admixture of two or more.

The molding using the polyvinyl chloride resin composition is not particularly limited in the present invention, but follows a known method.

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 spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims. The contents given below are based on solids content.

[Example]

Example  One : MBS system Impact modifier  Produce

(1) Production of rubber latex

80 parts by weight of ion-exchanged water, 52.5 parts by weight of 1,3-butadiene (BD), 16.8 parts by weight of styrene (SM), 0.7 parts by weight of divinylbenzene (DVB) and 0.95 part by weight of potassium oleate were added to a polymerization reactor (autoclave) , 0.1 part by weight of sodium formaldehyde sulfoxylate, 0.05 part by weight of diisopropylbenzene hydroperoxide, 0.11 part by weight of ethylenediaminetetra sodium acetate and 0.19 part by weight of ferrous sulfate.

Subsequently, the mixture was reacted at a reaction temperature of 70 ° C until the polymerization conversion rate reached 30 to 40%, and then 0.65 parts by weight of potassium oleate was added thereto, followed by reaction at 70 ° C until the polymerization conversion rate reached 60%. Subsequently, 0.65 part by weight of potassium oleate was further added thereto, and the temperature was raised to 80 DEG C, and the reaction was terminated at a polymerization conversion of 95%.

The time required for the polymerization was 23 hours, and the average particle size of the prepared butadiene-based latex polymer core was 190 nm.

(2) Primary Graft  polymerization

The obtained rubber latex was charged in a sealed reactor, and then nitrogen was charged. Then, 0.05 part by weight of ethylenediaminetetra sodium acetate, 0.009 part by weight of ferrous sulfate and 0.05 part by weight of sodium formaldehyde sulfoxylic acid were added thereto, , 11.8 parts by weight of methyl methacrylate (MMA), 0.2 part by weight of polyethylene glycol diacrylate (PEGDA), 0.20 part by weight of potassium oleate, 20 parts by weight of ion-exchanged water, and 0.07 part by weight of t-butylhydroperoxide, After 3 hours of addition, polymerization was further carried out for 1.5 hours.

(3) Secondary Graft  polymerization

A flask equipped with a stirrer, a thermometer, a nitrogen inlet, and a circulating condenser was charged with 120 parts by weight of ionized water, 16 parts by weight of styrene (SM), 2 parts by weight of phenyl methacrylate (PHMA) And 0.3 parts by weight of SDS were added, and the mixture was adjusted to 40 캜 and then nitrogen was injected for 20 minutes. To this, 0.1 part by weight of initiator (TBHP) was added, followed by reaction for 2 hours to carry out secondary graft polymerization.

The latex was solidified with sulfuric acid through the steps (1) to (3) to separate the polymer and water, followed by dehydration and drying to obtain an MBS impact modifier powder.

Example  2: MBS system Impact modifier  Produce

The MBS impact modifier powder was obtained in the same manner as in Example 1 except that 13 parts by weight of styrene (SM) and 5 parts by weight of phenyl methacrylate (PHMA) were used in the preparation of the second graft shell.

Comparative Example  One: MBS system Impact modifier  Produce

An MBS impact modifier powder was obtained in the same manner as in Example 1 except that 18 parts by weight of styrene (SM) was used in the preparation of the second graft shell.

Comparative Example  2: MBS system Impact modifier  Produce

The MBS impact modifier powder was obtained in the same manner as in Example 1 except that 16.8 parts by weight of methyl methacrylate (MMA) was used in the preparation of the first graft shell.

Comparative Example  3: MBS system Impact modifier  Produce

MBS impact modifier powder was obtained in the same manner as in Example 1 except that 13 parts by weight of styrene (SM) and 5 parts by weight of cyclohexyl methacrylate (CHMA) were used in the preparation of the second graft shell.

Comparative Example  4: MBS system Impact modifier  Produce

MBS impact modifier powder was obtained in the same manner as in Example 1 except that 8 parts by weight of styrene (SM) and 10 parts by weight of phenyl methacrylate (PHMA) were used in the preparation of the second graft shell.

Comparative Example  5: MBS system Impact modifier  Produce

MBS impact modifier powder was obtained in the same manner as in Example 1 except that 13 parts by weight of styrene (SM) and phenyl methacrylate (PHMA) were used in the preparation of the second graft shell.

Comparative Example  6: MBS system Impact modifier  Produce

The MBS impact modifier powder was obtained in the same manner as in Example 1, except that styrene (SM) weight parts and phenyl methacrylate (PHMA) were used in the preparation of the second graft shell.

Comparative Example  7: MBS system Impact modifier  Produce

MBS impact modifier powder was obtained in the same manner as in Example 1 except that styrene (SM) amount and phenyl methacrylate (PHMA) were used in the preparation of the second graft shell.

The contents, average particle diameter and refractive index (Abbe Refractometer) of the monomers constituting the MBS impact modifier powder prepared in the above Examples and Comparative Examples are summarized in Table 1 below.

Composition (% by weight) Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Rubber core BD 52.5 52.5 52.5 52.5 52.5 52.5 52.5 45 60 SM 16.8 16.8 16.8 16.8 16.8 16.8 16.8 14.4 19.2 DVB 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.6 0.8 The first graft shell MMA 11.8 11.8 11.8 16.8 11.8 11.8 11.8 16.8 6.8 PEGDA 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 The second graft shell SM 16 13 18 13 13 8 13 18 8 PHMA 2 5 0 0 0 10 5 5 5 CHMA 0 0 0 0 5 0 0 0 0 Average particle diameter (nm) 200 200 200 200 200 200 150 200 200 Refractive index 1.5390 1.5386 1.5393 1.5343 1.5351 1.5379 1.5386 1.5391 1.5381

Experimental Example  1: Preparation of polyvinyl chloride resin composition and measurement of physical properties

80% by weight of a poly (lactic acid) resin and 20% by weight of an MBS impact modifier prepared by the above method were mixed and melted and kneaded at 250 캜 using an extruder to obtain pellets. The obtained pellets were subjected to T-die extrusion at a die temperature of 220 占 폚 to obtain a sheet having a thickness of 0.5 mm.

The physical properties of the vinyl chloride resin obtained in the above Examples and Comparative Examples were evaluated as follows, and the results are shown in Table 1 below.

- Izod Impact Strength: evaluated according to ASTM D256 test method for 1/8 inch and 1/4 inch notched specimens. At this time, the measurement was carried out in a chamber kept at room temperature and -40 ° C., aging the 1/8 inch and 1/4 inch notched specimens at -40 ° C. for 6 hours, taking out the specimens, and performing the ASTM D256 test .

- Haze (%): Measured using a haze meter, the lower the value, the higher the transparency.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Impact strength (rpm) 1090 1140 1000 1180 1150 950 870 830 1050 Haze (%) 2.7 3.1 2.2 5.7 4.8 3.5 2.8 2.1 4.5

Referring to Table 2, it can be seen that the polyvinyl chloride resin produced by using the MBS impact modifier prepared according to the present invention has high impact strength and low haze, so that impact resistance and transparency are excellent.

In comparison, in Comparative Example 1 using an aromatic vinyl monomer alone without using an aromatic acrylic monomer as the second graft shell, the transparency was excellent but the impact strength was low.

In addition, in Comparative Example 2 in which the content of the methyl methacrylate monomer in the first graft shell was excessively used to increase the impact strength, the impact strength was improved but the transparency was lowered.

Thus, in Comparative Example 3 in which an aliphatic acrylic monomer other than an aromatic type was used in the second graft shell, the impact strength was increased but the transparency was also lowered.

Based on these results, when the aromatic acrylic monomer was used in excess, the impact strength and transparency were lowered at the same time as in Comparative Example 4.

When the MBS impact modifier has a small average particle size as in Comparative Example 5, it is understood that the impact strength and transparency are affected even when the content of the rubber core is excessive or small.

The MBS impact modifier according to the present invention can be used as an additive for a polyvinyl chloride resin composition to produce a molded article having excellent transparency and impact resistance.

Claims (9)

Based on 100% by weight of the total of the monomers constituting the MBS-based impact modifier,
65 to 79% by weight of a conjugated diene-based rubber core in which a conjugated diene-based monomer, an aromatic vinyl monomer and a crosslinkable monomer are copolymerized;
8-15 wt% of a first graft shell surrounding the core, wherein methyl methacrylate and polyalkylene glycol monomer are grafted; And
And 11 to 25 wt% of a second graft shell surrounding the first graft shell and having an aromatic vinyl monomer and an aromatic acrylic monomer grafted therein. The method according to claim 1,
The MBS-based impact modifier
A conjugated diene rubber core copolymerized with 46 to 59% by weight of a conjugated diene monomer, 15 to 20% by weight of an aromatic vinyl monomer, and 0.1 to 5% by weight of a crosslinkable monomer;
A first grafted shell grafted with 8-15 wt% methyl methacrylate and 0.05-5 wt% polyalkylene glycol monomer; And
A second graft shell having 10 to 20% by weight of an aromatic vinyl monomer and 1 to 9% by weight of an aromatic acrylic monomer grafted therein. The method according to claim 1,
Wherein the conjugated diene monomer is one selected from the group consisting of butadiene, isoprene, chloroisoprene, and combinations thereof. The method according to claim 1,
Wherein the aromatic vinyl monomer is one selected from the group consisting of styrene, alpha-methylstyrene, o-ethylstyrene, p-ethylstyrene, vinyltoluene, and combinations thereof. The method according to claim 1,
The crosslinkable monomer may be selected from the group consisting of divinylbenzene, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, , Allyl methacrylate, trimethylolpropane triacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, and combinations thereof. The MBS impact modifier according to claim 1, The method according to claim 1,
The polyalkylene glycol monomer may be selected from the group consisting of poly (ethylene glycol) monoacrylate, poly (ethylene glycol) monomethacrylate, poly (propylene glycol) monoacrylate, poly (propylene glycol) monomethacrylate, poly ) Diacrylate, poly (ethylene glycol) dimethacrylate, poly (propylene glycol) diacrylate, poly (propylene glycol) dimethacrylate, methoxypoly (ethylene glycol) monoacrylate, methoxy ) Monomethacrylate, phenoxypoly (ethylene glycol) monoacrylate, phenoxypoly (ethylene glycol) monomethacrylate, methoxypoly (propylene glycol) monoacrylate, Phenoxy poly (ethylene propylene) monoacrylate, phenoxy poly (ethylene propylene) monomethacrylate And combinations thereof. ≪ RTI ID = 0.0 > 1. < / RTI > The method according to claim 1,
Wherein the aromatic acrylic monomer is one selected from the group consisting of phenyl acrylate, phenyl methacrylate, and mixtures thereof. The method according to claim 1,
Wherein the MBS impact modifier has an average particle diameter of 160 to 300 nm. A polyvinyl chloride resin composition comprising the MBS impact modifier according to any one of claims 1 to 8.