KR20110077805A - And thermoplastic composition having impact modifier having core-shell structure - Google Patents

Abstract

PURPOSE: A thermoplastic resin composition comprising a graft copolymer having a core-shell structure with high refractivity is provided to ensure excellent appearance property and impact property. CONSTITUTION: A thermoplastic resin composition comprises (A) 100 parts by weight of a polycarbonate resin, (B) 45-55 parts by weight of a rubber-modified aromatic vinyl-based resin, and (C) 10-20 parts by weight of a core-shell graft copolymer. The shell of the core-shell graft-copolymer comprises one or more selected from the group consisting of phenylmethacrylate, cyclohexylmethacrylate, benzylmethacrylate, and phenoxymethacrylate. The core is a rubber polymer in which C4-6 diene rubber, acrylate rubber and silicone rubber monomers are polymerized.

Description

Thermoplastic composition having a graft copolymer comprising a core-shell structure {and Thermoplastic composition having impact modifier having core-shell structure}

The present invention relates to a thermoplastic composition comprising a graft copolymer comprising a core-shell structure, and more particularly, to a thermoplastic composition in which a graft copolymer including a core-shell structure as an impact modifier is well dispersed. .

Polycarbonate resins are excellent in transparency, mechanical strength as well as heat resistance, and are widely used in applications such as electric, electronic products, and automobile parts. However, since polycarbonate resins have disadvantages of poor processability and notched impact strength, they are used in combination with other types of resins to improve them, for example, blends of polycarbonate resins and rubber-modified aromatic vinyl resins. Can be referred to as a resin mixture with improved workability while maintaining a high notch impact strength.

On the other hand, since the polycarbonate-based resin composition is usually applied to large injection moldings, such as computer housings or other office equipment, it is necessary to maintain a high mechanical strength with the flame retardancy.

As described above, an impact modifier may be used in the thermoplastic resin composition to increase mechanical strength. Such impact modifiers are added a lot to compensate for the impact resistance of the thermoplastic resins having a low impact resistance. The impact modifier is generally a core-shell type structure composed of a shell of a thermoplastic resin component to improve compatibility of the rubber core particles with the thermoplastic resin.

An object of the present invention is to provide a silicone-based impact modifier made of a graft copolymer comprising a core-shell structure having a high refractive index.

Another object of the present invention is to provide a thermoplastic resin comprising a silicone-based impact modifier composed of a graft copolymer having a core-shell structure having excellent appearance characteristics.

All of the above and other purposes of the present invention may be achieved in accordance with the present invention as described in detail.

In order to achieve the above technical problem, the present invention (A) 100 parts by weight of polycarbonate resin, (B) 45 to 55 parts by weight of rubber-modified aromatic vinyl resin and (C) 10 to 20 parts by weight of the core-shell graft copolymer And wherein the shell of the core-shell graft copolymer comprises at least one selected from the group consisting of phenyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate and phenoxy methacrylate. It provides a resin composition.

Preferably, at least one selected from the group consisting of phenyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate and phenoxy methacrylate included in the shell is included in the content of 45 to 55% by weight in the shell. do.

In order to achieve the above technical problem, the present invention provides a molded article prepared from the thermoplastic resin composition according to the present invention.

The thermoplastic resin composition according to the present invention has excellent impact characteristics.

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

The present invention provides a thermoplastic resin composition comprising (A) 100 parts by weight of polycarbonate resin, (B) 45 to 55 parts by weight of rubber-modified aromatic vinyl resin, and (C) 10 to 20 parts by weight of the core-shell graft copolymer. .

A substance having affinity for the polycarbonate resin is introduced into the shell of the core-shell graft copolymer (C), and the dispersion is excellent in the resin composition.

Hereinafter, each component of the resin composition of the present invention will be described in detail.

(A) polycarbonate resin

The polycarbonate resin may be prepared by reacting a dihydric phenol compound and a phosgene in the presence of a molecular weight modifier and a catalyst according to a conventional production method. In another embodiment, the polycarbonate resin may be prepared using an ester interchange reaction of a dihydric phenol compound and a carbonate precursor such as diphenyl carbonate.

In the production method of such a polycarbonate resin, a bisphenol-based compound may be used as the dihydric phenol compound, and preferably 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) may be used. have. In this case, the bisphenol A may be partially or wholly replaced by another type of dihydric phenol compound. Examples of other types of dihydric phenolic compounds that can be used include hydroquinone, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane and 1,1-bis (4-hydroxyphenyl) cyclo Hexane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) Halogenated bisphenols such as sulfoxide, bis (4-hydroxyphenyl) ketone or bis (4-hydroxyphenyl) ether, and 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane Can be mentioned.

However, the type of dihydric phenolic compound that can be used for the production of the polycarbonate resin is not limited thereto, and the polycarbonate resin may be manufactured using any dihydric phenolic compound.

In addition, the polycarbonate resin may be a homopolymer using one type of dihydric phenolic compound, a copolymer using two or more types of dihydric phenolic compounds, or a mixture thereof.

In general, the polycarbonate resin may take the form of a linear polycarbonate resin, a branched polycarbonate resin, or a polyester carbonate copolymer resin, and the like, and the polycarbonate resin included in the polycarbonate resin composition may be formed in a specific form. Without limitation, all of these linear polycarbonate resins, branched polycarbonate resins, polyester carbonate copolymer resins, and the like can be used.

Among these, as said linear polycarbonate resin, a bisphenol-A polycarbonate resin can be used, for example, As said branched polycarbonate resin, For example, polyfunctionality, such as trimellitic anhydride or trimellitic acid, Those prepared by reacting an aromatic compound with a dihydric phenolic compound and a carbonate precursor can be used. As the polyester carbonate copolymer resin, for example, one produced by reacting a bifunctional carboxylic acid with a dihydric phenol and a carbonate precursor can be used. In addition, conventional linear polycarbonate resins, branched polycarbonate resins, or polyester carbonate copolymer resins can be used without limitation.

On the other hand, the polycarbonate resin is included in the content range of 85 to 99 parts by weight. As the polycarbonate resin is included in such a content range, the impact resistance may be further improved while reducing the transparency of the polycarbonate-based thermoplastic resin due to the addition of the core-shell graft copolymer described later.

(B) rubber-modified aromatic vinyl copolymer resin

The rubber-modified aromatic vinyl copolymer resin (B) according to the present invention is a polymer in which a rubbery polymer is dispersed and present in a particle form in a matrix (continuous phase) made of an aromatic vinyl polymer.

In one embodiment, the rubber-modified aromatic vinyl copolymer resin (B) is composed of 20 to 50% by weight of rubbery polymer units, 40 to 60% by weight of aromatic vinyl units and 10 to 30% by weight of vinyl cyanide units.

The rubber-modified aromatic vinyl copolymer resin is polymerized by adding an aromatic vinyl monomer and a monomer copolymerizable with the aromatic vinyl monomer optionally to the rubbery polymer. Such rubber-modified aromatic vinyl copolymer resins can be produced by known polymerization methods such as emulsion polymerization, suspension polymerization, and bulk polymerization, and graft copolymer resins and copolymer resins are usually produced by mixed extrusion. In the case of the bulk polymerization, the rubber modified aromatic vinyl copolymer resin is produced by only one step reaction without producing the graft copolymer resin and the copolymer resin separately, but in any case, the final rubber modified aromatic vinyl copolymer resin (B) Among the components, the rubber content is most suitably about 1 to about 30% by weight. The particle size of the rubber is about 0.1 to about 6.0 μm in Z-average, and in order to obtain desirable physical properties, it is more preferable that the rubber particle size is about 0.25 to about 3.5 μm in Z-average.

The rubber-modified aromatic vinyl copolymer resin used in the present invention may be prepared by using graft copolymer resin alone or in combination with a graft copolymer resin and a copolymer resin. desirable.

(B1) graft copolymer resin

The graft copolymer resin of the present invention is obtained by graft copolymerization of a rubbery polymer, an aromatic vinyl monomer, a monomer copolymerizable with an aromatic vinyl monomer, and a monomer which selectively gives processability and heat resistance.

Examples of the rubbery polymer include diene rubbers such as polybutadiene, poly (styrene-butadiene) and poly (acrylonitrile-butadiene), and acrylic rubbers such as saturated rubbers, isoprene rubbers and polybutylacrylic acid hydrogenated with the diene rubbers. Rubber and ethylene-propylene-diene monomer terpolymer (EPDM); Among these, especially diene rubber is preferable and butadiene rubber is more preferable. The amount of the rubbery polymer is suitably about 5 to about 65% by weight of the total weight of the graft copolymer resin (B ₁ ). The average size of the rubber particles is preferably in the range of about 0.1 to about 4 ㎛ in consideration of impact strength and appearance.

The aromatic vinyl monomer in the graft copolymerizable monomer mixture may include styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, para t-butylstyrene, ethyl styrene, vinyl xylene, monochlorostyrene, dichlorostyrene, Dibromostyrene, vinyl naphthalene, or the like may be used, but is not necessarily limited thereto. Of these, styrene is most preferred. The aromatic vinyl monomer is graft copolymerized using about 34 to about 94 weight% of the total weight of the graft copolymer resin (B1).

The graft copolymer resin (B1) of the present invention can introduce at least one monomer copolymerizable with an aromatic vinyl monomer. As the monomer to be introduced, vinyl cyanide such as acrylonitrile and unsaturated nitrile based compounds such as ethacrylonitrile and methacrylonitrile are preferable, and may be used alone or in combination of two or more thereof. The monomer is copolymerized using about 1 to about 30% by weight of the total weight of the graft copolymer resin (B1).

Examples of the monomer for imparting the processability and heat resistance include acrylic acid, methacrylic acid, maleic anhydride, and N-substituted maleimide. The amount of monomer added is about 0 to about 15% by weight of the total weight of the graft copolymer resin (B1).

(B2) copolymer resin

The copolymer resin (B2) is prepared according to the monomer ratio and compatibility of the components of the graft copolymer resin (B1) except for rubber, styrene-based monomers, monomers copolymerizable with styrene-based monomers, and optionally workability and heat resistance The monomer which gives is added and copolymerized.

As the styrene monomer, styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, para t-butylstyrene, ethyl styrene, monochlorostyrene, dichlorostyrene, dibromostyrene, and the like may be used. It is not limited to this. Of these, styrene is most preferred. In the present invention, the styrene-based monomer is used to obtain the copolymer resin using about 60 to about 90% by weight of the total weight of the copolymer resin (B2).

As an example of the monomer copolymerizable with the styrene monomer, a vinyl cyanide compound such as acrylonitrile or an unsaturated nitrile compound such as ethacrylonitrile or methacrylonitrile is preferable, and may be used alone or in combination of two or more thereof. . The content of the monomer copolymerizable with the styrene-based monomer is about 10 to about 40% by weight of the total weight of the copolymer resin (B2).

Acrylic acid, methacrylic acid, maleic anhydride, N-substituted maleimide, etc. are mentioned as a monomer for providing the said processability and heat resistance. The content of the monomer added at the time of copolymerization to impart processability and heat resistance is about 0 to about 30% by weight of the total weight of the copolymer resin (B2).

Examples of the rubber-modified aromatic vinyl copolymer resin (B) used in the present invention include acrylonitrile-butadiene-styrene copolymer resins (ABS resins) and acrylonitrile-ethylenepropylene rubber-styrene copolymer resins (AES resins). And acrylonitrile-acryl rubber-styrene copolymer resin (AAS resin).

Rubber modified aromatic vinyl copolymer resin (B) used in the present invention is in the ratio of about 10 to about 100% by weight of the graft copolymer resin (B1) and about 0 to about 90% by weight of the copolymer resin (B2). Use a mixture. In an embodiment, the rubber-modified aromatic vinyl copolymer resin (B) is composed of about 55 to about 90 wt% of the graft copolymer resin (B1) and about 10 to about 45 wt% of the copolymer resin (B2). In another embodiment, the rubber-modified aromatic vinyl copolymer resin (B) may be composed of 15 to 50% by weight of the graft copolymer resin (B1) and 50 to 85% by weight of the copolymer resin (B2).

In the present invention, the (B) rubber-modified styrene copolymer resin is used in an amount of 45 to 55 Pa by weight relative to 100 parts by weight of the polycarbonate resin (A). (B) Since the rubber-modified styrenic copolymer resin plays a role of facilitating workability, impact resistance, appearance and flame retardancy, the above properties are lowered when applied to less than 45 wt%, and when used in excess of 55 wt%. , There may be a problem in which phase separation with the polycarbonate resin and the like appear.

(C) core-shell graft copolymer

The core-shell graft copolymer (C) has a core-shell structure by grafting an unsaturated monomer to a rubber core structure to form a hard shell, and serves as an impact modifier in the resin composition.

The rubber is preferably prepared by polymerizing one or more rubber monomers selected from the group consisting of monomers of 4 to 6 carbon atoms, acrylate rubbers, and silicone rubbers.

Examples of the acrylate rubber include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, hexyl methacrylate, 2-ethylhexyl (meth) acrylate, and the like. Acrylate monomers may be used, wherein ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate or 1,4-butylene glycol di Curing agents, such as (meth) acrylate, allyl (meth) acrylate, or triallyl cyanurate, can be used.

The silicone rubber is prepared from cyclosiloxane, and specific examples thereof include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, and tetramethyltetraphenyl. Cyclotetrosiloxane, an octaphenylcyclo tetrasiloxane, etc. are mentioned. One or more of these siloxanes can be selected to produce a silicone rubber, and at this time, a curing agent such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, or tetraethoxysilane can be used.

Among the rubbers, it is more preferable to use a silicone rubber or to use a silicone rubber and an acrylate rubber in combination. In addition, it is more preferable that the rubber has an average particle diameter of 0.4 to 1 µm for maintaining impact resistance and coloring balance.

In addition, the rubber is preferably included in 50 to 90 parts by weight of the core-shell graft copolymer (C). It is preferable because it is excellent in compatibility with resin within the said range, and can show the outstanding impact reinforcement effect as a result.

As the unsaturated monomer graftable to the rubber, at least one unsaturated compound selected from the group consisting of (meth) acrylic acid alkyl esters, (meth) acrylic acid esters, acid anhydrides, alkyl or phenyl nucleosubstituted maleimides can be used. have.

The methacrylic acid alkyl esters or acrylic acid alkyl esters are monohydryl alcohols as esters of acrylic acid or methacrylic acid, respectively. Specific examples of these include methacrylic acid methyl ester, methacrylic acid ethyl ester, methacrylic acid propyl ester, and the like, and among these, methacrylic acid methyl ester is more preferable.

Examples of the acid anhydride include carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride.

The shell of the core-shell graft copolymer includes a material that is friendly to the polycarbonate resin, thereby enhancing the affinity with the polycarbonate resin phase so that the impact modifier can be evenly distributed, thereby improving the impact characteristics.

The polycarbonate resin-friendly material is phenyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenoxy methacrylate, and the like, and may be included in the shell and polymerized.

Preferably, the content of phenyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenoxy methacrylate, etc., which are friendly to the polycarbonate resin contained in the shell, is 45 to 55% by weight of the shell. to be. When included in a small amount less than the above range may be low compatibility with the PC, when included in excess over the above range may result in low polymerization stability or increase the overall refractive index may cause Haze when compounding.

Further, preferably, at least one selected from the group consisting of phenyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate and phenoxy methacrylate contained in the shell is selected from the group consisting of 5 or more of the core-shell graft copolymers. To 10% by weight.

The (C) core-shell graft copolymer may be preferably composed of 65 to 75% by weight of the core and 25 to 35% by weight of the shell. Within the above range, it is excellent in compatibility with the resin, and as a result can exhibit an excellent impact reinforcing effect.

The core-shell graft copolymer (C) is preferably included in an amount of 10 parts by weight to 20 parts by weight, more preferably 5 to 8 parts by weight, relative to 100 parts by weight of the polycarbonate resin (A). When included in the content range it is possible to obtain an impact reinforcement effect, and also to improve the mechanical strength, such as tensile strength, flexural strength, and flexural modulus.

(D) other additives

The thermoplastic resin composition having the composition as described above may contain other additives such as flame retardants, lubricants, antibacterial agents, mold release agents, nucleating agents, plasticizers, thermal stabilizers, antioxidants, light stabilizers, compatibilizers, pigments, dyes, inorganic additives, and the like. It may contain 0.1 to 0.8 parts by weight relative to 100 parts by weight of the polycarbonate resin.

The thermoplastic resin composition having the composition as described above may be prepared by a known method for preparing a resin composition, and for example, the components and other additives may be mixed at the same time, and then melt-extruded in an extruder to prepare pellets. .

The thermoplastic resin composition may be usefully applied to manufacturing various molded articles such as exterior parts of electric and electronic products such as TVs, computers, mobile phones, and office automation devices, and automobile precision parts.

Accordingly, the present invention provides a molded article prepared from the thermoplastic resin composition according to the present invention.

This invention may be better understood than by the following embodiments, which are intended to illustrate the purposes of the present invention and are not intended to limit the scope of protection, which is limited by the appended claims.

Manufacturing example  One

70 parts by weight of polybutadiene latex (Cheil Wool), a stearic acid solution and water were mixed as an emulsifier, a mixed solution was prepared and dispersed as a core, followed by 15 parts by weight of methyl methacrylate (Samjeon Pure Chemical Co., Ltd.) and phenyl methacrylate ( Daelim Chemical) 15 parts by weight were added together with a redox-based initiator (KPS) to graft polymerize to form a shell. The impact modifier powder was obtained by aggregating, washing with water and drying with an aqueous solution of MgSO ₄ .

Manufacturing example  2

An impact modifier powder was obtained in the same manner as in Preparation Example 1, except that cyclohexyl methacrylate (Aldrich) was used instead of phenyl methacrylate (Daelim Chemical) as a monomer component to form the shell.

Manufacturing example  3

An impact modifier powder was obtained in the same manner as in Preparation Example 1, except that benzyl methacrylate (Aldrich) was used instead of phenyl methacrylate (Daelim Chemical) as a monomer component for forming the shell.

Manufacturing example  4

An impact modifier powder was obtained in the same manner as in Preparation Example 1, except that phenoxyethyl methacrylate (Aldrich) was used instead of phenyl methacrylate (Daelim Chemical) as a monomer component to form the shell.

Manufacturing example  5

Except that 15 parts by weight of methyl methacrylate (Samjeon Pure Chemical Co., Ltd.) and 30 parts by weight of methyl methacrylate (Samjeon Pure Chemical) were used instead of 15 parts by weight of phenyl methacrylate (Daelim Chemical) as a monomer component for forming the shell. The impact modifier powder was obtained in the same manner as in Example 1.

Example  One

A specimen was prepared by mixing and processing 8% by weight of the impact modifier powder prepared in Preparation Example 1 in PC-ABS resin (Cheil Industries, Staroy HP-1001N).

A transmission electron microscope (TEM) photograph of the resin prepared in the above example is shown in FIG. 1.

Example  2

The specimen was prepared by mixing and processing 8% by weight of the impact modifier powder prepared in Preparation Example 2 in PC-ABS resin (Cheil Industries, Staroy HP-1001N).

Example  3

The specimen was prepared by mixing and processing 8% by weight of the impact modifier powder prepared in Preparation Example 3 in PC-ABS resin (Cheil Industries, Staroy HP-1001N).

Example  4

A specimen was prepared by mixing and processing 8% by weight of the impact modifier powder prepared in Preparation Example 4 in PC-ABS resin (Cheil Industries, Staroy HP-1001N).

Comparative example

Izod impact specimens were prepared by mixing and processing 8% by weight of the impact modifier powder prepared in Preparation Example 5 in PC-ABS resin (Cheil Industries, Staroy HP-1001N).

A transmission electron microscope (TEM) photograph of the resin prepared in Comparative Example is shown in FIG. 2.

Table 1 shows the IZOD impact strength of the specimens prepared in Examples and Comparative Examples obtained through the above procedure.

Izod impact strength: measured by ASTM D-256 method. Unit is kgfcm / cm

Physical property evaluation results for Preparation Examples 1 to 5, Examples and Comparative Examples are shown in Table 1 below.

Example  One Example  2 Example  3 Example  4 Comparative example IZOD 1/4 " 47.1 46.3 46.1 45.1 43.9 1/8 " 92.9 91.9 91.0 90.9 88.4 weld 16.1 16.2 15.8 15.4 12.3

From Table 1, the Example was found to have good polymerizability, but the IZOD value was better than the Comparative Example.

1 is a transmission electron microscope (TEM) photograph of a specimen prepared from a thermoplastic resin composition according to one embodiment of the present invention.

FIG. 2 is a transmission electron microscope (TEM) image of a specimen prepared from a thermoplastic resin composition including an impact modifier in which a methyl methacrylate is graft polymerized on a butadiene latex core to form a shell.

Claims (7)

(A) 100 parts by weight of polycarbonate resin; (B) 45 to 55 parts by weight of rubber-modified aromatic vinyl resin; And (C) 10 to 20 parts by weight of the core-shell graft copolymer, The shell of the core-shell graft copolymer is at least one selected from the group consisting of phenyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate and phenoxy methacrylate thermoplastic resin composition. The thermoplastic resin composition of claim 1, wherein the core is a rubber polymer obtained by polymerizing a diene rubber, an acrylate rubber, and a silicone rubber monomer having 4 to 6 carbon atoms. The core-shell structure of claim 1, wherein the shell is grafted with an unsaturated monomer selected from the group consisting of (meth) acrylic acid alkyl esters, (meth) acrylic acid esters, acid anhydrides, and alkyl or phenyl-substituted maleimides. The thermoplastic resin composition characterized in that it was formed. According to claim 3, wherein at least one selected from the group consisting of phenyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate and phenoxy methacrylate contained in the shell content of 45 to 55% by weight in the shell Thermoplastic resin composition, characterized in that it is included as. The thermoplastic resin composition of claim 1, wherein the (C) core-shell graft copolymer comprises 65 to 75 wt% of the core and 35 to 45 wt% of the shell. According to claim 1, 0.1 to 0.8 parts by weight of one or more additives selected from the group consisting of flame retardants, lubricants, antibacterial agents, mold release agents, nucleating agents, plasticizers, heat stabilizers, antioxidants, light stabilizers, compatibilizers, pigments, dyes and inorganic additives It further comprises a thermoplastic resin composition. The molded article manufactured from the thermoplastic resin composition of any one of Claims 1-6.

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