KR100656971B1 - Impact modifier with high refractive index for excellent coloring and toughening ability at low temperature, and method for preparing the same - Google Patents

Abstract

Provided are an impact modifier which has a high refractive index, its preparation method, and a thermoplastic resin composition containing the impact modifier which is excellent in coloration and low temperature impact resistance. The impact modifier comprises a rubber core which is prepared by firstly swelling polymerizing a styrene-based aromatic compound in the presence of an organosiloxane crosslinked polymer particle having a particle size of 50-400 nm to prepare a polymer, adding an alkyl acrylate to the polymer to secondly swell it, and crosslinking polymerizing it; and a plastic shell which is a polymer or copolymer prepared by graft polymerizing a vinyl monomer on the rubber core. The impact modifier has a refractive index of 1.490-1.590.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high refractive index impact modifier excellent in coloring property and low temperature impact resistance and a method for manufacturing the high refractive index impact modifier,

Field of invention

The present invention relates to an impact modifier added to a thermoplastic resin such as a polycarbonate resin. More specifically, the present invention relates to a high refractive index silicone impact modifier which is added to a thermoplastic resin and exhibits excellent coloring property and low temperature impact resistance.

BACKGROUND OF THE INVENTION

In general, polycarbonate resins are widely used in office automation equipment, electrical and electronic products as engineering plastics because they have excellent impact resistance, self-extinguishing properties, electrical properties, transparency, dimensional stability and thermal stability compared with other resins come.

However, since polycarbonate resins have a high melting point, they are required to have a high molding temperature due to low fluidity, resulting in a problem that the impact resistance is lowered due to overheating of the resin. To overcome these problems, various impact modifiers have been applied to polycarbonate resins.

A series of impact modifiers used to overcome the above problems also have another problem. The butadiene impact modifier, which is generally used as an impact modifier of polycarbonate resin, is greatly restricted in its use due to the degradation of the butadiene rubber and the degradation of thermal stability at a molding condition of 300 ° C or higher. Further, in the case of an acrylic impact modifier, there is a problem that it is poor in coloring property and low-temperature impact resistance, while being excellent in thermal stability and weather resistance.

U.S. Patent Nos. 4,994,522 and 5,132,359 disclose a silicone impact modifier as an impact modifier for a vinyl chloride resin. However, when applied to a polycarbonate resin, it is difficult to apply it to a polycarbonate resin because of its disadvantage in that it has poor heat resistance, low-temperature impact resistance and weather resistance, but has poor coloring ability.

In order to solve such coloring problem, JP-A-1994- 116470 discloses an impact reinforcing agent to which a silicone polymer having a particle diameter of 100 nm or less is applied. However, when it is applied to a polycarbonate resin, impact resistance is remarkably reduced. Japanese Laid-Open Patent Publication No. 2004-331726 discloses an impact modifier to which a silicone polymer having a particle size distribution of 300 to 2,000 nm is applied. However, this has the drawback that the coloring property decreases as the thickness of the resin increases.

Korean Patent No. 2005-0049973 discloses an impact modifier that improves the coloring property while maintaining impact resistance when applied to a polycarbonate resin by improving the refractive index. However, it has a low impact resistance at low temperatures and has a limitation in application at low temperatures.

Accordingly, the present inventors formed a rubber core through primary swelling polymerization of a styrenic aromatic compound in the presence of organosiloxane crosslinked (co) polymer particles having a specific size and refractive index range, and secondary swelling polymerization in which an alkyl acrylate is crosslinked and polymerized The polymer or copolymer of the vinyl monomer is formed into a plastic shell through graft polymerization to maintain a high refractive index and to lower the glass transition temperature of the alkyl acrylate resin to thereby provide excellent coloring property and low temperature impact resistance when applied to a thermoplastic resin To develop an impact modifier.

An object of the present invention is to provide an impact modifier capable of exhibiting excellent coloring property and low temperature impact resistance when applied to a thermoplastic resin by imparting a high refractive index and a low glass transition temperature while maintaining the existing physical properties of a silicone impact modifier.

Another object of the present invention is to provide an impact modifier which exhibits excellent thermal stability, coloring property, impact resistance and low temperature impact resistance when applied to a polycarbonate resin.

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

 SUMMARY OF THE INVENTION

High-refractive-index impact modifier of the present invention (A) (a ₁₎ in the presence of a particle size of 50~400 nm organosiloxane cross-linked polymer particles (a ₂₎ a styrenic polymer and the aromatic compound (a ₃₎ alkyl acrylate cross-linked (B) a plastic shell formed through graft polymerization of a vinyl monomer, and has a high refractive index of 1.490 to 1.590.

The organosiloxane crosslinked polymer of the present invention preferably contains an aromatic group and has a refractive index of 1.410 to 1.500.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

(A) Rubber core

The rubber core of the present invention is obtained by firstly polymerizing a styrene-based aromatic compound (a ₂ ) in the presence of (a ₁ ) organosiloxane crosslinked polymer particles, adding (a ₃ ) alkyl acrylate to the first- Secondary swelling.

The organosiloxane crosslinked (co) polymer of the present invention contains an aromatic group and has a refractive index of 1.410 to 1.500 and a particle size of 50 to 400 nm. If an organosiloxane crosslinked polymer having a refractive index of less than 1.410 is used, it is difficult to impart a refractive index of 1.490 or more while maintaining the physical properties of the impact modifier. In the case of using an organosiloxane copolymer having a refractive index of more than 1.500, The glass transition temperature rises and compatibility with various organic solvents increases to cause serious deterioration of various physical properties such as impact resistance and chemical resistance. It is preferable that the refractive index is 1.410 to 1.500, and the refractive index is more preferably 1.420 to 1.450 in consideration of various physical property balances.

In addition, when the particle size of the organosiloxane crosslinked (co) polymer is less than 50 nm or exceeds 400 nm, the impact reinforcing effect is significantly reduced, so that the particle size is preferably 50 to 400 nm.

The organosiloxane crosslinked (co) polymer (a ₁ ) of the present invention is a crosslinked organosiloxane, specifically crosslinked dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane and the like. The organosiloxane crosslinked polymer composed only of pure dimethyl siloxane has a refractive index in the range of 1.390 to 1.405, and the refractive index can be controlled in the range of 1.410 to 1.500 by including an aromatic group, so that it is preferable to use an organosiloxane copolymer containing an aromatic group . More preferably, the aromatic group includes a phenyl group. The organosiloxane copolymer may be one which is not cross-linked, but if it is not cross-linked, the organosiloxane copolymer loses its rubber properties and the impact resistance is reduced, and the surface movement of the organosiloxane or instability of the morphology It is preferable to use a resin which is in a crosslinked state.

The crosslinking state of the organosiloxane copolymer can be determined by the degree of dissolution by various organic solvents. As the crosslinking state deepens, the degree of dissolution by the solvent becomes smaller. As the solvent for determining the crosslinking state, acetone, toluene or the like can be used. At this time, it is preferable to have a portion that is not dissolved by acetone or toluene, and more preferably, the insoluble matter to toluene of the organosiloxane copolymer is 30% or more.

The styrene-based aromatic compound may be styrene, alphamethylstyrene, divinylbenzene, vinyltoluene, etc. Styrene is preferably used.

The alkyl acrylate may be methyl acrylate, ethyl acrylate, n-butyl acrylate or the like, preferably n-butyl acrylate having a low glass transition temperature.

In the present invention, (a ₁₎ an organosiloxane cross-linked polymer and (a ₃₎ the weight ratio of alkyl acrylate cross-linked polymer is from 1: preferably 1: 6-6. Organosiloxane cross-linked polymer (a ₁₎ and the alkyl acrylate ratio of the cross-linked polymer (a _3): if 6 is less than the, and a significantly reduced impact reinforcing effects at a low temperature by the organosiloxane cross-linked polymers, 6: exceed one The effect of reinforcing the impact is deteriorated due to the decrease of the dendritic solubility due to the excessive amount of the organosiloxane crosslinked polymer and the production cost is increased.

In the present invention, the weight ratio of the styrene type aromatic compound polymer (a ₂ ) to the alkyl acrylate crosslinked polymer (a ₃ ) is preferably 1:20 to 1: 1. When the weight ratio of the styrene type aromatic compound polymer to the alkyl acrylate crosslinked polymer is less than 1:20, the refractive index and coloring property are remarkably decreased. When the weight ratio is more than 1: 1, the impact resistance is remarkably decreased.

Styrenic aromatic compound polymer of the present invention (a _second) and the cross-linked polymer alkyl acrylate (a ₃₎ is an organosiloxane cross-linked (co) polymer (a ₁₎ were combined in sequential swelling in the presence of the particles in two stages alkyl acrylate It is preferable that the glass transition temperature of the cross-linking polymer is maintained at -10 to -40 占 폚. If the styrene-based aromatic compound and the alkyl acrylate are simultaneously copolymerized, the glass transition temperature of the alkyl acrylate crosslinked polymer is increased and the impact resistance is lowered. In addition, when a styrene-based aromatic compound or an alkyl acrylate cross-linked polymer is produced by a graft polymerization method in which the polymerization is proceeded with the continuous introduction of monomers, the physical properties such as impact resistance and coloring property are lowered, and thus the styrene type aromatic compound or alkyl acrylate cross- It is preferable to prepare by the swelling polymerization method in which the polymerization initiator is added by polymerizing the monomer sufficiently after the swelling time is added.

(B) Plastic shell

The plastic shell of the present invention is formed on the outer surface of the rubber core (A) by graft polymerization of a vinyl monomer to the rubber core (A) as a polymer or copolymer of a vinyl monomer.

As the vinyl-based monomer in the present invention, alkyl methacrylate, acrylate, and ethylenically unsaturated aromatic compounds can be used. Preferably, a single substance such as methyl methacrylate, styrene, acrylonitrile, or a mixture of two or more thereof is used . It is more preferable to use a styrene-based aromatic compound in order to maximize the refractive index and coloring property.

The weight ratio of the rubber core (A) to the plastic shell (B) of the present invention is preferably 5: 5 to 9: 1. If the ratio of the plastic shell (B) to the rubber core (A) is less than 5: 5, the impact reinforcing effect is remarkably deteriorated due to the insufficient rubber content. When the ratio is 9: 1 or more, There is a problem that the cost of production is excessively increased with the decrease of the effect.

The impact modifier of the present invention has a refractive index in the range of 1.490 to 1.590, preferably in the range of 1.500 to 1.570. If the refractive index of the impact modifier is less than 1.490 as in the case of the conventional silicone impact modifier, the difference in refractive index from the polycarbonate resin having a refractive index of 1.570 to 1.590 is significant and the coloring property is remarkably lowered.

Hereinafter, the production process of the silicone impact modifier of the present invention will be described in detail.

The high refractive index impact modifier of the present invention is prepared by primary swelling polymerization of an organosiloxane crosslinked polymer having an aromatic group and having a refractive index of 1.410 to 1.500 and a particle size of 50 to 400 nm by adding a styrenic aromatic compound, Swelling and cross-linking to prepare a rubber core, and graft-polymerizing the vinyl-based monomer to the rubber core to form a plastic shell.

The organosiloxane crosslinked polymer of the present invention uses a silicone latex which is stably dispersed on an ion exchange water using an emulsifier.

Also, the organosiloxane crosslinked polymer is a crosslinked organosiloxane, wherein the organosiloxane is selected from the group consisting of dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane, and mixtures / copolymers thereof. In the present invention, the organosiloxane crosslinked polymer is used in an amount of 5 to 90 parts by weight, preferably 10 to 50 parts by weight, based on the total weight of the reactants.

As the emulsifier, anionic emulsifiers such as sodium, ammonium or potassium salts of alkyl sulfates having 4 to 30 carbon atoms can be used. Specifically, sodium dodecyl sulfate or sodium dodecylbenzenesulfate is used. It is preferred to use sodium dodecylbenzenesulphate which is available at double wide pH ranges. In the present invention, the emulsifier is used in an amount of 0.1 to 5 parts by weight, preferably 0.1 to 2 parts by weight, based on the total weight of the reactants.

The styrene-based aromatic monomer is added to the silicone latex under a nitrogen stream and the temperature is raised to 50 to 100 ° C to swell the styrene-based aromatic monomer to the organosiloxane crosslinked (co) polymer. Thereafter, the polymerization initiator is added and polymerization proceeds at 50 to 100 캜.

The styrene-based aromatic compound monomer of the present invention may be styrene, alphamethylstyrene, divinylbenzene, vinyltoluene, or a mixture thereof, preferably styrene. The styrene-based aromatic compound monomer is used in an amount of 0.01 to 50 parts by weight, preferably 1 to 30 parts by weight, based on the total weight of the reactants.

After the temperature of the solution is lowered to room temperature, an alkyl acrylate monomer and a crosslinking agent are introduced under a nitrogen stream, and the temperature is raised again to 50 to 100 DEG C to swell the organosiloxane crosslinked polymer-styrene type aromatic compound polymer. Thereafter, a polymerization initiator is added and polymerization is carried out at 50 to 100 캜 to prepare a rubber core.

As the alkyl acrylate monomer of the present invention, methyl acrylate, ethyl acrylate, n-butyl acrylate and the like can be used, and the n-butyl acrylate having a low glass transition temperature is preferably used. In the present invention, the alkyl acrylate monomer is used in an amount of 5 to 90 parts by weight, preferably 10 to 50 parts by weight, based on the total weight of the reactants.

As the crosslinking agent in the present invention, allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene and the like can be used. Preferably, allyl methacrylate or triallyl isocyanonate is used. More preferably, triallyl isocyanurate is used. In the present invention, the crosslinking agent is used in an amount of 0.01 to 10 parts by weight, preferably 0.01 to 5 parts by weight, based on the weight of the total reactants.

The polymerization initiator uses free-radical initiators which are initiators that generate free radicals by thermal decomposition or oxidation-reduction reaction. Specifically, it is possible to use potassium persulfate, magnesium persulfate, benzoyl peroxide, hydrogen peroxide, dibenzyl peroxide, cumene hydroperoxide, tert -butyl hydroperoxide and the like, and it is preferable to use water-soluble potassium persulfate. In the present invention, the polymerization initiator is used in an amount of 0.1 to 5 parts by weight, preferably 0.1 to 2 parts by weight, based on the weight of the total reactants.

Thereafter, a polymerization initiator and a vinyl monomer are continuously introduced at 50 to 100 占 폚 to form a plastic shell, followed by coagulation and filtration using a coagulant to produce a high refractive index silicone impact modifier.

The vinyl monomer may be an alkyl methacrylate, an acrylate or an ethylenically unsaturated aromatic compound. Preferably, the vinyl monomer is a single substance such as methyl methacrylate, styrene, or acrylonitrile, or a mixture of two or more thereof. In the present invention, the vinyl monomer is used in an amount of 5 to 90 parts by weight, preferably 10 to 50 parts by weight, based on the total weight of the reactants.

As the coagulant, a metal salt is used in a large amount. Specifically, magnesium chloride, calcium chloride, magnesium sulfate, calcium sulfate and the like can be used.

The impact modifier prepared by the above-mentioned method has a high refractive index of 1.490 to 1.590, and when applied to a thermoplastic resin, can exhibit excellent coloring property and low temperature impact resistance. The thermoplastic resin which can be applied to the impact modifier of the present invention is not particularly limited and can be applied to vinyl chloride resin, styrene resin, styrene-acrylonitrile resin, acrylic resin, ester resin, ABS resin and polycarbonate resin And the effect is maximized when it is applied to a polycarbonate resin used as an exterior material of an electronic apparatus.

In particular, when the high refractive index impact modifier of the present invention is applied to polycarbonate resin, 0.5 to 30 parts by weight of the high refractive index impact modifier is preferably included relative to 100 parts by weight of the polycarbonate resin.

The present invention may be better understood by the following examples, which are for the purpose of illustrating the invention and are not intended to limit the scope of protection defined by the appended claims.

Example 1

90 g of a dimethylsiloxane-diphenylsiloxane crosslinked copolymer having a refractive index of 1.429, a particle size of 220 nm and a toluene insoluble content of 65%, and 3.2 g of sodium dodecylbenzene sulfate were dispersed in 970 g of ion- 36 g were mixed at room temperature for 1 hour and then the temperature of the mixture was raised to 75 캜. A solution prepared by dissolving 0.4 g of potassium persulfate in 22.5 g of ion-exchanged water was added and the temperature was maintained at 75 캜 for 2 hours.

After the reaction solution was cooled to room temperature, 190 g of n-butyl acrylate and 9 g of triallyl isocyanurate were mixed at room temperature for 1 hour. After raising the temperature of the mixed solution to 75 캜 again, a solution prepared by dissolving 0.9 g of potassium persulfate in 22.5 g of ion exchange water was added and maintained at 75 캜 for 2 hours to prepare a rubber core.

Thereafter, a solution prepared by dissolving 0.7 g of potassium persulfate in 22.5 g of ion-exchanged water was further added, and then 135 g of styrene was added for 15 minutes. Thereafter, it was kept at 75 DEG C for 4 hours and then cooled to room temperature. The final reaction conversion rate was 96.8%.

The 1.5% MgSO ₄ aqueous solution and the final reaction solution were mixed at 75 ° C, washed with water and dried to obtain an impact modifier powder.

Example 2

A rubber core was prepared in the same manner as in Example 1, and then a solution prepared by dissolving 0.7 g of potassium persulfate in 22.5 g of ion-exchanged water was further added. Then, 101.25 g of styrene and 33.75 g of acrylonitrile were mixed, . Thereafter, it was kept at 75 DEG C for 4 hours and then cooled to room temperature. The final conversion rate was 96.3%.

The 1.5% MgSO ₄ aqueous solution and the final reaction solution were mixed at 75 ° C, washed with water and dried to obtain an impact modifier powder.

Example 3

90 g of a dimethylsiloxane-diphenylsiloxane crosslinked copolymer having a refractive index of 1.424, a particle size of 295 nm and a toluene insoluble content of 60%, and 3.2 g of sodium dodecylbenzene sulfate were dispersed in 970 g of ion-exchanged water, 22.5 g were mixed at room temperature for 1 hour and then the temperature of the mixture was raised to 75 캜. A solution prepared by dissolving 0.3 g of potassium persulfate in 6.4 g of ion-exchanged water was added and the temperature was maintained at 75 캜 for 1 hour.

After cooling the reaction solution to 50 캜, 202.5 g of n-butyl acrylate and 2.5 g of triallyl isocyanurate were mixed and stirred for 1 hour. After raising the temperature of the mixed solution to 75 캜 again, a solution prepared by dissolving 1.5 g of potassium persulfate in 32.5 g of ion exchanged water was added and maintained at 75 캜 for 2 hours to prepare a rubber core.

Then, a solution prepared by dissolving 1 g of potassium persulfate in 21 g of ion-exchanged water was further added, and then 135 g of styrene was added for 30 minutes. Thereafter, it was kept at 75 DEG C for 2 hours and then cooled to room temperature. The final reaction conversion rate was 97.2%.

The 1% MgSO ₄ aqueous solution and the final reaction solution were mixed at 75 ° C, washed with water and dried to obtain an impact modifier powder.

Example 4

90 g of a dimethylsiloxane-diphenylsiloxane crosslinked copolymer having a refractive index of 1.429, a particle size of 198 nm and a toluene insoluble content of 63%, and 3.2 g of sodium dodecylbenzene sulfate were dispersed in 970 g of ion-exchanged water, 22.5 g were mixed at room temperature for 1 hour and then the temperature of the mixture was raised to 75 캜. A solution prepared by dissolving 0.3 g of potassium persulfate in 6.4 g of ion-exchanged water was added and the temperature was maintained at 75 캜 for 1 hour.

After cooling the reaction solution to 50 캜, 189 g of n-butyl acrylate and 9 g of allyl methacrylate were mixed and stirred for 1 hour. After raising the temperature of the mixed solution to 75 캜 again, a solution prepared by dissolving 1.5 g of potassium persulfate in 32.5 g of ion exchanged water was added and maintained at 75 캜 for 2 hours to prepare a rubber core.

Then, a solution prepared by dissolving 1 g of potassium persulfate in 21 g of ion-exchanged water was further added, and then 135 g of styrene was added for 30 minutes. Thereafter, it was kept at 75 DEG C for 2 hours and then cooled to room temperature. The final reaction conversion rate was 93.9%.

The 1.5% MgSO ₄ aqueous solution and the final reaction solution were mixed at 75 ° C, washed with water and dried to obtain an impact modifier powder.

Comparative Example 1

90 g of a dimethylsiloxane-diphenylsiloxane crosslinked copolymer having a refractive index of 1.429, a particle size of 220 nm and a toluene insoluble content of 65%, and 3.2 g of sodium dodecylbenzene sulfate were dispersed in 970 g of ion-exchanged water, 190 g of butyl acrylate, 36 g of styrene and 9 g of triallyl isocyanurate were mixed at room temperature for 1 hour. Thereafter, the temperature of the mixed solution was raised to 75 DEG C, and a solution prepared by dissolving 1.8 g of potassium persulfate in 45 g of ion-exchanged water was added and maintained at 75 DEG C for 4 hours to prepare a rubber core.

Thereafter, a solution prepared by dissolving 0.7 g of potassium persulfate in 22.5 g of ion-exchanged water was further added, and then a solution prepared by mixing 101.25 g of styrene and 33.75 g of acrylonitrile was added for 15 minutes. Thereafter, it was kept at 75 DEG C for 4 hours and then cooled to room temperature. The final exchange rate was 96.6%.

The 1.5% MgSO ₄ aqueous solution and the final reaction solution were mixed at 75 ° C, washed with water and dried to obtain an impact modifier powder.

Comparative Example 2

A solution prepared by dissolving 0.7 g of potassium persulfate in 22.5 g of ion-exchanged water was further added to the rubber core prepared in Comparative Example 1, and then a solution prepared by mixing 135 g of methyl methacrylate was added dropwise for 15 minutes. Thereafter, it was kept at 75 DEG C for 4 hours and then cooled to room temperature. The final conversion rate was 97.9%.

The 1.5% MgSO ₄ aqueous solution and the final reaction solution were mixed at 75 ° C, washed with water and dried to obtain an impact modifier powder.

Comparative Example  3

157.5 g of a dimethylsiloxane crosslinked polymer having a refractive index of 1.404, a particle size of 300 nm and a toluene insoluble content of 69%, and 3.15 g of sodium dodecylbenzene sulfate were dispersed in 976 g of ion-exchanged water, and a silicone latex having a n-butyl acrylate 153 g and 4.5 g of allyl methacrylate were mixed at room temperature for 1 hour.

The same procedure as in Comparative Example 1 was followed to obtain an impact modifier powder. The final conversion rate was 97.6%.

Comparative Example 4

90 g of a dimethylsiloxane-diphenylsiloxane crosslinked copolymer having a refractive index of 1.424, a particle size of 295 nm and a toluene insoluble content of 60%, and 3.2 g of sodium dodecylbenzene sulfate were dispersed in 970 g of ion-exchanged water, g were mixed at room temperature and the temperature of the mixture was raised to 75 캜. A solution prepared by dissolving 0.3 g of potassium persulfate in 6.4 g of ion-exchanged water was added and the temperature was maintained at 75 캜 for 2 hours.

Thereafter, a solution prepared by dissolving 1.5 g of potassium persulfate in 32.5 g of ion-exchanged water was added, and a solution prepared by mixing 202.5 g of n-butyl acrylate and 2.5 g of triallyl isocyanurate was added dropwise for 1 hour, And maintained for 1 hour.

The same procedure as in Example 1 was followed to obtain an impact modifier powder. The final conversion rate was 95.6%.

The silicone impact modifier particles obtained through the above process were evaluated for physical properties through the following methods.

(1) Refractive index and glass transition temperature: A specimen (thickness: 1 mm) was obtained by using a hot press. The refractive indices of the specimens were measured using a prism coupler type laser refractometer (Sairon Tech., SPA-4000) using a light source with a wavelength of 632.8 nm. Using a dynamic mechanical analyzer (Rheometric Scientific, MKII) The glass transition temperature of the rubber phase was measured.

(2) Colorability: The color of the specimen prepared by mixing polycarbonate, impact modifier and dye in a ratio of 97: 3: 0.2 was evaluated by the five-point method.

(3) Impact resistance: Polycarbonate and an impact modifier were mixed in a ratio of 97: 3 to prepare a pellet using a twin-screw extruder = 45 mm. The pellets were dried at 110 ° C. for 3 hours or more and then injected in a 10 oz injection machine at a molding temperature of 260 to 330 ° C. and a mold temperature of 60 to 100 ° C. to prepare 1/4 "specimens. The impact strength was measured by ASTM D-256 ≪ / RTI >

As shown in Table 1, the impact modifier prepared in Examples 1 to 4 had a high refractive index of 1.490 or more and a low butyl acrylate rubber-phase glass transition temperature of -10 ° C or less as compared with the impact modifiers of Comparative Examples 1 to 3 It looked. Also, it showed excellent coloring property and low temperature impact resistance. In addition, as can be seen from Comparative Example 4, when the rubber core was produced by the graft polymerization method without swelling polymerization, it was confirmed that the coloring property and the low temperature impact resistance were reduced.

The present invention relates to a method of swelling-polymerizing a styrenic aromatic compound in the presence of an organosiloxane crosslinked (co) polymer particle having an aromatic group and having a refractive index of 1.410 to 1.500 and a particle size of 50 to 400 nm, and then subjecting the alkyl acrylate monomer to swelling- (Co) polymer of a vinyl monomer as a plastic shell, thereby providing a silicone-based impact modifier having a high refractive index of 1.490 to 1.590. When this is applied to a thermoplastic resin, it has an effect of excellently exhibiting coloring property and low temperature impact resistance.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

(A) polymerizing a styrene-based aromatic compound in the presence of organosiloxane crosslinked polymer particles having a particle size of 50 to 400 nm by primary swollen polymerization, adding the alkyl acrylate to the polymer formed by the first swollen polymerization A rubber core produced by cross-linking after secondary swelling; And (B) a plastic shell formed of a polymer or copolymer graft-polymerized with a vinyl monomer on the rubber core; , And has a refractive index of 1.490 to 1.590. The impact modifier of claim 1, wherein the organosiloxane crosslinked polymer comprises an aromatic group and has a refractive index in the range of 1.410 to 1.500. The organosiloxane crosslinked polymer of claim 1, wherein the organosiloxane crosslinked polymer is 5 to 90 parts by weight; The styrene-based aromatic compound is 0.01 to 50 parts by weight; The alkyl acrylate is 5 to 90 parts by weight; And the polymer or copolymer of the vinyl monomer (B) is 5 to 90 parts by weight. 2. The composition of claim 1, wherein the organosiloxane is selected from the group consisting of dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane and mixtures or copolymers thereof; Wherein said styrenic aromatic compound is selected from the group consisting of styrene, alphamethylstyrene, divinylbenzene and vinyltoluene; Wherein the alkyl acrylate is selected from the group consisting of methyl acrylate, ethyl acrylate and n-butyl acrylate; And the vinyl-based monomer is selected from the group consisting of methyl methacrylate, styrene, acrylonitrile, and mixtures thereof. The impact modifier according to claim 1, wherein allyl methacrylate or triallyl isocyanate is used as a crosslinking agent in the production of the cross-linked polymer of the alkyl acrylate. The impact modifier according to claim 1, wherein the weight ratio of the rubber core (A) to the plastic shell (B) is 5: 5 to 9: 1. Swelling polymerizing the styrene-based aromatic compound at 50 to 100 DEG C in the presence of organosiloxane crosslinked polymer particles having a particle size of 50 to 400 nm, swelling the acrylate monomer at a temperature of 80 DEG C or less, crosslinking at 50 to 100 DEG C Producing a rubber core; And Graft polymerization of the vinyl monomer to the rubber core to form a plastic shell; By weight based on the total weight of the impact modifier. A thermoplastic resin composition comprising an impact modifier according to any one of claims 1 to 6. The thermoplastic resin composition according to claim 8, wherein the thermoplastic resin is selected from the group consisting of a vinyl chloride resin, a styrene resin, a styrene-acrylonitrile resin, an acrylic resin, an ester resin, an ABS resin and a polycarbonate resin And a thermoplastic resin composition. The thermoplastic resin composition according to claim 9, wherein when the thermoplastic resin is a polycarbonate resin, the thermoplastic resin composition contains 0.5 to 30 parts by weight of an impact modifier based on 100 parts by weight of the polycarbonate resin.