WO2025110572A1 - Thermoplastic resin composition and molded article manufactured therefrom - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition and a molded article manufactured therefrom, the thermoplastic resin composition comprising: relative to 100 parts by weight of a base resin containing (A) 50 to 70 wt% of a polycarbonate resin, (B) 10 to 30 wt% of an alpha-methylstyrene-styrene-acrylonitrile copolymer, and (C) 10 to 30 wt% of a polysiloxane-polycarbonate copolymer resin, (D) 1 to 3 parts by weight of a siloxane-modified polyester, and (E) 1 to 3 parts by weight of syndiotactic polystyrene.

Description

Thermoplastic resin composition and molded article manufactured therefrom

The present invention relates to a thermoplastic resin composition and a molded article manufactured therefrom.

Thermoplastic resins have lower specific gravity than glass or metal and have advantages such as excellent formability and impact resistance. Recently, with the trend toward lower cost, larger size, and lighter weight of electrical and electronic products, plastic products using thermoplastic resins are rapidly replacing the areas of existing glass and metal, and are expanding their areas of use from electrical and electronic products to automobile parts.

Among thermoplastic resins, polycarbonate (PC) resins are lightweight and have excellent impact resistance, heat resistance, and rigidity, so they are widely used in electrical and electronic products and automobile parts. For example, polycarbonate resins can be used as unpainted materials for automobile interior/exterior materials, allowing molded products to be used as they are without going through a painting process, in line with strengthened environmental regulations.

However, polycarbonate resin has relatively poor scratch resistance, so when used as an unpainted material, there are problems such as appearance degradation and discoloration. In order to solve this problem, there have been many attempts to blend polycarbonate resin with other resins, but there is a problem that the mechanical properties, colorability, etc. are reduced due to blending of such resins, and the original effects of polycarbonate resin cannot be achieved.

Therefore, a thermoplastic resin composition that can secure a certain level of scratch resistance while maintaining excellent impact resistance and heat resistance, and at the same time exhibit excellent colorability is required.

One embodiment provides a thermoplastic resin composition having excellent impact resistance and scratch resistance as well as excellent colorability.

Another embodiment provides a molded article having excellent impact resistance, scratch resistance, and colorability, manufactured from the thermoplastic resin composition.

According to one embodiment, a thermoplastic resin composition comprises 100 parts by weight of a base resin including (A) 50 to 70 wt% of a polycarbonate resin; (B) 10 to 30 wt% of an alpha-methylstyrene-styrene-acrylonitrile copolymer; and (C) 10 to 30 wt% of a polysiloxane-polycarbonate copolymer resin; (D) 1 to 3 parts by weight of a siloxane-modified polyester; and (E) 1 to 3 parts by weight of a syndiotactic polystyrene.

The above (B) alpha-methylstyrene-styrene-acrylonitrile copolymer may include 50 to 60 wt% of structural units derived from alpha-methylstyrene, 15 to 30 wt% of structural units derived from styrene, and 20 to 30 wt% of structural units derived from acrylonitrile, based on 100 wt% of the copolymer.

The above (C) polysiloxane-polycarbonate copolymer resin comprises a siloxane structural unit and a carbonate structural unit, and the siloxane structural unit can be expressed by the following chemical formula 1:

[Chemical Formula 1]

In the above chemical formula 1,

R ³ and R ⁴ are, each independently, a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C3 to C30 cycloalkenyl group, a substituted or unsubstituted C3 to C30 cycloalkynyl group, a substituted or unsubstituted C6 to C30 aryloxy group, a substituted or unsubstituted C6 to C30 aryl group, or NRR' (wherein R and R' are the same as or different from each other and are a hydrogen atom or a substituted or unsubstituted C1 to C20 alkyl group),

* is a connection point.

The above (C) polysiloxane-polycarbonate copolymer resin may contain 1 to 50 wt% of a siloxane structural unit represented by the chemical formula 1 based on 100 wt% of the copolymer resin.

The above (C) polysiloxane-polycarbonate copolymer resin may have a weight average molecular weight of 10,000 to 100,000 g/mol.

The above (D) siloxane modified polyester can be expressed by the following chemical formula 2:

[Chemical formula 2]

In the above chemical formula 2,

R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a C1 to C5 alkylene group,

R ⁹ is a C1 to C4 alkyl group or a phenyl group,

R ¹⁰ is hydrogen, hydroxyl group, or methyl group,

l, m and n are each independently an integer greater than or equal to 1.

In the above chemical formula 2, R ⁵ and R ⁶ are each a propylene group, R ⁷ and R ⁸ are each a pentylene group, R ⁹ is a methyl group, and l, m and n may be integers of 1 or more satisfying l + m : n = 15 to 20 : 25 to 35.

The above (E) syndiotactic polystyrene may have a syndiotacticity of 97 to 100%.

The above (A) polycarbonate resin may have a weight average molecular weight of 10,000 to 100,000 g/mol.

The thermoplastic resin composition may further include at least one additive selected from a flame retardant, a nucleating agent, a coupling agent, glass fiber, a plasticizer, a lubricant, a mineral filler, an antibacterial agent, a release agent, a heat stabilizer, an antioxidant, a pigment, a dye, and an antistatic agent.

A molded article according to another embodiment is manufactured from a thermoplastic resin composition according to the above embodiment.

The above molded product may have a notched Izod impact strength of 15 kgf·cm/cm or more as measured in accordance with ASTM D256 for a 1/8 inch thick specimen.

The above molded product may have a brightness (L*) of 2.0 or less when measured in the Specular Component Excluded (SCE) mode according to ASTM E308 on a 2.5 mm thick black specimen.

The above molded product may have a brightness change (ΔL*) of 2.5 or less before and after scratch resistance evaluation as measured using an Erichsen Scratch Hardness Tester 430 P-I on a black specimen.

A thermoplastic resin composition according to one embodiment of the present invention and a molded article manufactured therefrom have excellent impact resistance and scratch resistance, as well as excellent colorability.

Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples, and the present invention is not limited thereby, and the present invention is defined only by the appended claims.

Unless specifically stated herein, “copolymer” includes random copolymerization, block copolymerization, and graft copolymerization, and “copolymer” includes random copolymer, block copolymer, and graft copolymer.

Unless otherwise specified herein, “weight average molecular weight” is the value obtained by dissolving a powder sample in an appropriate solvent and measuring it using Agilent Technologies’ 1200 series Gel Permeation Chromatography (GPC) (Shodex polystyrene is used as the standard sample).

According to one embodiment, a thermoplastic resin composition is provided, comprising (A) 50 to 70 wt% of a polycarbonate resin; (B) 10 to 30 wt% of an alpha-methylstyrene-styrene-acrylonitrile copolymer; and (C) 10 to 30 wt% of a polysiloxane-polycarbonate copolymer resin, relative to 100 wt% of a base resin, (D) 1 to 3 wt% of a siloxane-modified polyester; and (E) 1 to 3 wt% of a syndiotactic polystyrene.

In order to improve the scratch resistance of conventional polycarbonate resins, there have been attempts to blend acrylic resins, which have higher hardness than polycarbonate, with polycarbonate resins. However, in this case, although the scratch resistance could be improved, there was a problem that the optical properties were deteriorated because the acrylic resin had a lower refractive index than the polycarbonate resin. As another method, polycarbonate resins and phenyl methacrylate-methyl methacrylate copolymers (modified acrylic resins) were used together, but in this case as well, although the scratch resistance was improved, there was a problem that the mechanical properties were deteriorated.

Meanwhile, when blending a high refractive index resin having a similar refractive index to that of polycarbonate resin with polycarbonate resin, it was difficult to achieve excellent colorability due to low compatibility with the polycarbonate resin in most cases.

Accordingly, the inventors of the present invention confirmed that by mixing (B) an alpha-methylstyrene-styrene-acrylonitrile copolymer having a high refractive index and good compatibility with a polycarbonate resin, with (A) a polycarbonate resin, scratch resistance can be improved while maintaining excellent colorability, and further confirmed that a molded article manufactured from a thermoplastic resin composition further comprising (C) a polysiloxane-polycarbonate copolymer resin, (D) a siloxane-modified polyester, and (E) syndiotactic polystyrene has excellent physical properties such as impact resistance and scratch resistance, and at the same time has excellent colorability to the extent that it can realize a dark and deep color like piano black, thereby completing the present invention.

Hereinafter, each component included in the thermoplastic resin composition will be described in detail.

(A) Polycarbonate resin

(A) Polycarbonate (PC) resin is a polyester having a carbonate bond, and its type is not particularly limited, and any polycarbonate resin available in the field of thermoplastic resin compositions can be used. Polycarbonate resin has excellent properties such as impact resistance, heat resistance, and lightness, and thus a molded product manufactured from a thermoplastic resin composition containing the same can have excellent impact resistance.

For example, the polycarbonate resin (A) above can be produced by reacting a diphenol represented by the following chemical formula X with a compound selected from the group consisting of phosgene, halogen acid ester, carbonic ester, or a combination thereof.

[chemical formula X]

In the above chemical formula X,

A is a linking group selected from the group consisting of a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C2 to C5 alkenylene group, a substituted or unsubstituted C2 to C5 alkylidene group, a substituted or unsubstituted C1 to C30 haloalkylene group, a substituted or unsubstituted C5 to C6 cycloalkylene group, a substituted or unsubstituted C5 to C6 cycloalkenylene group, a substituted or unsubstituted C5 to C10 cycloalkylidene group, a substituted or unsubstituted C6 to C30 arylene group, a substituted or unsubstituted C1 to C20 alkoxylene group, a halogen acid ester group, a carbonic acid ester group, C=O, S and SO ₂ , R ¹ and R ² are each independently a substituted or unsubstituted C1 to C30 alkyl group or a substituted or unsubstituted C6 to C30 aryl group, and n1 and n2 are each independently 0 to It is an integer of 4.

In the above chemical formula X, A is, for example, a single bond, or a substituted or unsubstituted C1 to C10 alkylene group, R ¹ and R ² are each independently a substituted or unsubstituted C1 to C10 alkyl group, and n1 and n2 are each independently 0 or 1, but are not limited thereto.

Two or more diphenols represented by the above chemical formula X may be combined to form the repeating unit of the above (A) polycarbonate resin.

Specific examples of the above diphenols include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2-bis(4-hydroxyphenyl)propane (also called "bisphenol-A"), 2,4-bis(4-hydroxyphenyl)-2-methylbutane, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(3-chloro-4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, Bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)ketone, bis(4-hydroxyphenyl)ether, etc. can be mentioned. Among the above diphenols, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, or 1,1-bis(4-hydroxyphenyl)cyclohexane can be preferably used. 2,2-bis(4-hydroxyphenyl)propane can be more preferably used.

The above (A) polycarbonate resin may be a mixture of copolymers prepared from two or more diphenols. In addition, the above (A) polycarbonate resin may use linear polycarbonate resin, branched polycarbonate resin, polyester carbonate copolymer resin, etc.

A specific example of the linear polycarbonate resin may be a bisphenol-A based polycarbonate resin. A specific example of the branched polycarbonate resin may be a resin produced by reacting a polyfunctional aromatic compound, such as trimellitic anhydride or trimellitic acid, with diphenols and carbonates. The polyester carbonate copolymer resin may be produced by reacting a difunctional carboxylic acid with diphenols and carbonates, and the carbonate used here may be a diaryl carbonate, such as diphenyl carbonate, or ethylene carbonate.

The above (A) polycarbonate resin may have a weight average molecular weight of 10,000 to 100,000 g/mol, for example, 10,000 to 80,000 g/mol, for example, 10,000 to 60,000 g/mol, for example, 10,000 to 50,000 g/mol, for example, 10,000 to 30,000 g/mol, but is not limited thereto. When the weight average molecular weight of the above (A) polycarbonate resin is within the above range, the thermoplastic resin composition of the present invention and the molded article manufactured therefrom can obtain excellent impact resistance and fluidity.

The above (A) polycarbonate resin can be included in an amount of 50 to 70 wt%, for example, 50 to 60 wt%, for example, 60 to 70 wt%, based on 100 wt% of the base resin including (A) polycarbonate resin, (B) alpha-methylstyrene-styrene-acrylonitrile copolymer to be described later, and (C) polysiloxane-polycarbonate copolymer resin. In the above wt% range, the thermoplastic resin composition of the present invention and the molded article manufactured therefrom can exhibit excellent mechanical properties.

The above (A) polycarbonate resin may have a melt flow index (MI) of 5 to 30 g/10 min, for example, 5 to 10 g/10 min, as measured under the conditions of 300° C. and 1.2 kg according to ASTM D1238. When the melt flow index of the above (A) polycarbonate resin is within the above range, the thermoplastic resin composition of the present invention and the molded article manufactured therefrom may exhibit excellent moldability and excellent impact resistance.

The above (A) polycarbonate resin can be used by mixing two or more polycarbonate resins having different weight average molecular weights or melt flow indices. By mixing and using polycarbonate resins having different weight average molecular weights or melt flow indices, it is easy to control the thermoplastic resin composition to have the desired fluidity.

(B) alpha-methylstyrene-styrene-acrylonitrile copolymer

A thermoplastic resin composition according to one embodiment can improve scratch resistance and also realize excellent colorability by including (B) an alpha-methylstyrene-styrene-acrylonitrile copolymer. This is because (B) an alpha-methylstyrene-styrene-acrylonitrile copolymer has a similar refractive index to (A) a polycarbonate resin and excellent compatibility.

The above (B) alpha-methylstyrene-styrene-acrylonitrile copolymer comprises a structural unit derived from alpha-methylstyrene, a structural unit derived from styrene, and a structural unit derived from acrylonitrile.

The above (B) alpha-methylstyrene-styrene-acrylonitrile copolymer may contain 50 to 60 wt% of a structural unit derived from alpha-methylstyrene, 15 to 30 wt% of a structural unit derived from styrene, and 20 to 30 wt% of a structural unit derived from acrylonitrile, based on 100 wt% of the copolymer. In the above range, the compatibility with the (A) polycarbonate resin is excellent, so that the thermoplastic resin composition of the present invention and the molded article manufactured therefrom can excellently maintain the colorability and scratch resistance.

The above (B) alpha-methylstyrene-styrene-acrylonitrile copolymer may be included in an amount of 10 to 30 wt% based on 100 wt% of the base resin, for example, 10 to 25 wt%, for example, 15 to 30 wt%, for example, 15 to 25 wt%, for example, 20 to 30 wt%. In the above wt% range, the thermoplastic resin composition of the present invention and the molded article manufactured therefrom may have excellent scratch resistance and colorability.

(C) Polysiloxane-polycarbonate copolymer resin

A thermoplastic resin composition according to one embodiment of the present invention includes (C) a polysiloxane-polycarbonate copolymer resin, thereby improving compatibility between each component in the thermoplastic resin composition and implementing excellent impact resistance.

The above (C) polysiloxane-polycarbonate copolymer resin comprises a siloxane structural unit and a carbonate structural unit, and the siloxane structural unit can be expressed by the following chemical formula 1:

[Chemical Formula 1]

In the above chemical formula 1,

R ³ and R ⁴ are each independently a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C3 to C30 cycloalkenyl group, a substituted or unsubstituted C3 to C30 cycloalkynyl group, a substituted or unsubstituted C6 to C30 aryloxy group, a substituted or unsubstituted C6 to C30 aryl group, or NRR' (wherein R and R' are the same as or different from each other and are a hydrogen atom, or a substituted or unsubstituted C1 to C20 alkyl group),

* is a connection point.

The above (C) polysiloxane-polycarbonate copolymer resin can contain 1 to 50 wt% of the siloxane structural unit represented by the above chemical formula 1 based on 100 wt% of the copolymer resin, for example, 1 to 40 wt%, for example, 1 to 30 wt%, for example, 1 to 20 wt%, for example, 1 to 10 wt%, but is not limited thereto. When the (C) polysiloxane-polycarbonate copolymer resin contains the siloxane structural unit in the above range, the scratch resistance and impact resistance of the thermoplastic resin composition of the present invention and the molded article manufactured therefrom can be further improved.

The above (C) polysiloxane-polycarbonate copolymer resin may have a weight average molecular weight of 10,000 to 100,000 g/mol, for example, 10,000 to 80,000 g/mol, for example, 10,000 to 60,000 g/mol, for example, 10,000 to 40,000 g/mol, for example, 15,000 to 40,000 g/mol, for example, 15,000 to 35,000 g/mol. In the above range, the impact resistance of the thermoplastic resin composition of the present invention and the molded article manufactured therefrom may be excellent.

The above (C) polysiloxane-polycarbonate copolymer resin may be included in an amount of 10 to 30 wt% based on 100 wt% of the base resin, for example, 10 to 25 wt%, for example, 15 to 30 wt%, for example, 15 to 25 wt%, for example, 20 to 30 wt%. In the above wt% range, the compatibility between each component in the thermoplastic resin composition is excellent, and the thermoplastic resin composition of the present invention and the molded article manufactured therefrom may have excellent scratch resistance and impact resistance.

(D) Siloxane modified polyester

A thermoplastic resin composition according to one embodiment can improve scratch resistance by including (D) a siloxane-modified polyester, and the (D) siloxane-modified polyester can be represented by the following chemical formula 2:

[Chemical formula 2]

In the above chemical formula 2,

R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a C1 to C5 alkylene group,

R ⁹ is a C1 to C4 alkyl group or a phenyl group,

R ¹⁰ is hydrogen, hydroxyl group, or methyl group,

l, m and n are each independently an integer greater than or equal to 1.

In the above chemical formula 2, the siloxane structural unit is indicated as being located in the center of the copolymer, and the ester structural units are located at both ends, but this does not specify the positions of the structural units. That is, the (D) siloxane-modified polyester according to one embodiment may be a random copolymer as well as a block copolymer. Therefore, in the above chemical formula 2, the ester structural unit and the siloxane structural unit are indicated as being included in the copolymer in numbers of l + m and n, respectively, and each structural unit is not limited to being present at a specific position in the form of a block.

In one embodiment, R ⁵ and R ⁶ of the chemical formula 2 are each a propylene group, R ⁷ and R ⁸ are each a pentylene group, R ⁹ is a methyl group, and l, m and n may be integers of 1 or more satisfying l + m : n = 15 to 20 : 25 to 35.

The above (D) siloxane-modified polyester may be included in an amount of 1 to 3 parts by weight based on 100 parts by weight of the base resin, for example, 1 to 2 parts by weight, for example, 2 to 3 parts by weight. In the above weight range, the thermoplastic resin composition of the present invention and the molded article manufactured therefrom may have excellent scratch resistance.

(E) Syndiotactic polystyrene

A thermoplastic resin composition according to one embodiment can improve impact resistance by including (E) syndiotactic polystyrene.

Polystyrene can generally be divided into atactic, isotactic, and syndiotactic structures depending on the location of the benzene rings in the side chain. Atactic polystyrene has the benzene rings arranged irregularly, while isotactic polystyrene has the benzene rings arranged on one side of the polymer main chain. On the other hand, syndiotactic polystyrene has the benzene rings arranged regularly and alternately.

In one embodiment, the (E) syndiotactic polystyrene can be used, and the (E) syndiotactic polystyrene can be produced by using a catalyst system comprising a styrene monomer, a metallocene catalyst, and a cocatalyst. The metallocene catalyst has a structure in which one or two cycloalkane dienyl groups (cyclopentadienyl groups, indenyl groups, fluorenyl groups, and derivatives thereof) are linked to a group Ⅳ transition metal complex of the periodic table, such as Ti, Zr, and Hf.

As a prior art for polystyrene having high stereoregularity, high melting point, and excellent molecular weight distribution, U.S. Patent No. 6,010,974 discloses a method for polymerizing styrene monomer using a new alkyl-bridged dinuclear metallocene catalyst, a silyl-bridged dinuclear metallocene catalyst, and an alkyl-silyl bridged dinuclear metallocene catalyst, and U.S. Patent No. 6,284,700 discloses a method for producing syndiotactic polystyrene using a catalyst system comprising a metallocene catalyst and a cocatalyst. The disclosures of these patents are incorporated by reference in their entirety into the present specification.

The above (E) syndiotactic polystyrene may have a syndiotacticity of 97 to 100%.

The above (E) syndiotactic polystyrene may be included in an amount of 1 to 3 parts by weight, for example, 1 to 2 parts by weight, for example, 2 to 3 parts by weight, based on 100 parts by weight of the base resin. In the above weight range, the thermoplastic resin composition of the present invention and the molded article manufactured therefrom may have excellent impact resistance.

(F) Additive

A thermoplastic resin composition according to one embodiment may further include, in addition to the components (A) to (E), one or more additives necessary to balance the properties under conditions of maintaining excellent scratch resistance, impact resistance, and colorability, or depending on the final use of the thermoplastic resin composition.

In one embodiment, at least one additive selected from flame retardants, nucleating agents, coupling agents, glass fibers, plasticizers, lubricants, mineral fillers, antimicrobial agents, release agents, heat stabilizers, antioxidants, pigments, dyes, and antistatic agents may be used.

These additives may be appropriately included within a range that does not impair the properties of the thermoplastic resin composition, and may be included in amounts of, for example, 0.1 to 20 parts by weight, 0.1 to 15 parts by weight, or 0.1 to 10 parts by weight relative to 100 parts by weight of the base resin, but are not limited thereto.

The thermoplastic resin composition of the present invention can be produced by a known method for producing a thermoplastic resin composition.

For example, the thermoplastic resin composition of the present invention can be manufactured in the form of pellets by mixing the components of the present invention and other additives, and then melting/mixing them in an extruder. The manufactured pellets can be manufactured into various molded articles (products) through various molding methods such as injection molding, extrusion molding, vacuum molding, and casting molding. Such molding methods are well known to those skilled in the art to which the present invention pertains. Since the molded article has excellent impact resistance, scratch resistance, and colorability, it can be utilized as interior/exterior materials for automobiles, interior/exterior materials for electrical and electronic products, and building materials. For example, since the molded article has excellent colorability to the extent that it can realize a dark and deep color such as piano black, it can be utilized as an unpainted material for the interior/exterior of automobiles.

Another embodiment of the present invention provides a molded article manufactured from the thermoplastic resin composition described above.

The above molded article may have a notched Izod impact strength of at least 15 kgf·cm/cm, for example at least 16 kgf·cm/cm, or at least 18 kgf·cm/cm, as measured in accordance with ASTM D256 on a 1/8 inch thick specimen, but is not limited thereto.

The above molded article may have a lightness (L*) of 2.0 or less, for example, 1.7 or less, for example, 1.5 or less, for example, 1.4 or less, as measured on a black 2.5 mm thick specimen in specular elimination mode (SCE Mode) according to ASTM E308, but is not limited thereto.

The above molded product may have a brightness change (ΔL*) before and after a scratch resistance evaluation measured using an Erichsen Scratch Hardness Tester 430 P-I on a black specimen of 2.5 or less, for example, 2.3 or less, for example, 2.0 or less, for example, 1.5 or less, for example, 1.3 or less, for example, 1.1 or less, but is not limited to these ranges.

Hereinafter, preferred embodiments of the present invention will be described. However, the following embodiments are only preferred embodiments of the present invention, and the present invention is not limited to the following embodiments.

Examples 1 to 5 and Comparative Examples 1 to 6

Thermoplastic resin compositions of Examples 1 to 5 and Comparative Examples 1 to 6 were prepared according to the component content ratios described in Table 1 below. Specifically, a mixture containing the components of Table 1 below and 0.5 part by weight of carbon black as an additive for implementing a black color was continuously fed into the feed section of a twin-screw extruder (L/D = 29, diameter = 45 mm), melted/kneaded, extruded, and processed to obtain a thermoplastic resin composition in the form of pellets. At this time, the barrel temperature of the twin-screw extruder was set to about 260°C. Subsequently, the pelletized thermoplastic resin composition was dried at about 80°C for about 4 hours, and then a 6-ounce injection molding machine having a cylinder temperature of about 270°C and a mold temperature of about 60°C was used to prepare a specimen for measuring physical properties.

In Table 1 below, (A) to (C), and (b) represent the weight % of each component among 100 weight % of the base resin, and (D) and (E) represent weight parts based on 100 weight parts of the base resin ((A) + (B) + (C)).

division Example Comparative example 1 2 3 4 5 1 2 3 4 5 6 (A) 60 70 50 60 50 80 80 60 30 60 60 (B) 20 10 20 20 30 - 20 - 50 20 20 (b) - - - - - - - 20 - - - (C) 20 20 30 20 20 20 - 20 20 20 20 (D) 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 - 1.5 (E) 2 2 2 1 2 2 2 2 2 2 -

The components listed in Table 1 above are as follows.

(A) Polycarbonate resin

Panlite® L-1250WP from Teijin, having a weight-average molecular weight of approximately 25,000 g/mol, was used.

(B) alpha-methylstyrene-styrene-acrylonitrile copolymer

Alpha-methylstyrene-styrene-acrylonitrile copolymer from Lotte Chemical Co., Ltd. was used as a copolymer composed of about 54 wt% of structural units derived from alpha-methylstyrene, about 19 wt% of structural units derived from styrene, and about 27 wt% of structural units derived from acrylonitrile.

(b) alpha-methylstyrene-acrylonitrile copolymer

Alpha-methylstyrene-acrylonitrile copolymer from Lotte Chemical Co., Ltd. was used as a copolymer consisting of about 32 wt% of structural units derived from acrylonitrile and about 68 wt% of structural units derived from alpha-methylstyrene.

(C) Polysiloxane-polycarbonate copolymer resin

A polysiloxane-polycarbonate copolymer resin having a weight average molecular weight of approximately 24,000 g/mol and containing approximately 3 to 6 wt% of siloxane structural units was used, a product of Samyang Corporation.

(D) Siloxane modified polyester

H-Si 6441 P from Evonik Industries was used.

(E) Syndiotactic polystyrene

Idemitsu Kosan's 130ZC was used.

evaluation

The following evaluations were performed on specimens for measuring physical properties manufactured from thermoplastic resin compositions according to the above examples and comparative examples, and the results are as shown in Table 2 below.

(1) Impact strength: Notched Izod impact strength (unit: kgf·cm/cm) was measured for 1/8 inch thick specimens according to ASTM D256.

(2) Colorability: The brightness (L*) value was measured in the specular elimination mode (SCE Mode) for 2.5 mm thick specimens using the Konica Minolta CM-3700D according to ASTM E308. The lower the brightness, the better the black color expression, so it was judged that the colorability was good.

(3) Scratch resistance: Using an Erichsen Scratch Hardness Tester 430 P-I, a test tip with a diameter of 1 mm was used to apply scratches to the specimen at 2 mm intervals for 20 times in a grid pattern under the conditions of a load of 10 N and a scratch speed of 1 m/min. The change in brightness (ΔL*) of the specimen before and after the scratch evaluation was measured using a Konica Minolta CM-3700D in the specular emission elimination mode (SCE Mode). When scratches are applied, microcracks occur on the surface of the specimen, creating flaws that increase the brightness of the specimen. Therefore, it was determined that the higher the change in brightness (ΔL*), the more damage caused by the scratches, and thus the lower the scratch resistance.

division Example Comparative example 1 2 3 4 5 1 2 3 4 5 6 Izod impact strength 25 30 28 18 16 75 8 12 7 11 10 Brightness(L*) 1.2 0.9 1.3 1.1 1.4 0.9 4.5 3.6 2.8 1.1 1.1 Change in brightness (ΔL*) 1.0 2.5 1.2 1.1 0.9 4.7 1.1 1.1 0.8 4.8 1.0

Referring to Tables 1 and 2 above, in the case of thermoplastic resin compositions according to comparative examples in which any one of the components (A) polycarbonate resin, (B) alpha-methylstyrene-styrene-acrylonitrile copolymer, (C) polysiloxane-polycarbonate copolymer resin, (D) siloxane-modified polyester, and (E) syndiotactic polystyrene is excluded, it can be confirmed that at least one of the properties of impact resistance, colorability, and scratch resistance is reduced. On the other hand, it can be confirmed that the thermoplastic resin composition according to the example including all of the components has excellent impact resistance and scratch resistance, as well as excellent colorability.

The above characteristics are characteristics required for unpainted materials for automobile interior/exterior, and it can be confirmed that a molded product manufactured from a thermoplastic resin composition according to one embodiment exhibits all of the required levels of impact resistance, scratch resistance, and colorability.

Although the present invention has been described above through preferred embodiments as described above, the present invention is not limited thereto, and those engaged in the technical field to which the present invention pertains will easily understand that various modifications and variations are possible without departing from the concept and scope of the patent claims described below.

Claims (14)

(A) 50 to 70 wt% of polycarbonate resin; (B) 10 to 30 wt% of alpha-methylstyrene-styrene-acrylonitrile copolymer; and (C) For 100 parts by weight of a base resin containing 10 to 30 wt% of a polysiloxane-polycarbonate copolymer resin (D) 1 to 3 parts by weight of siloxane-modified polyester; and (E) 1 to 3 parts by weight of syndiotactic polystyrene A thermoplastic resin composition comprising: In paragraph 1, The above (B) alpha-methylstyrene-styrene-acrylonitrile copolymer is a thermoplastic resin composition comprising 50 to 60 wt% of a structural unit derived from alpha-methylstyrene, 15 to 30 wt% of a structural unit derived from styrene, and 20 to 30 wt% of a structural unit derived from acrylonitrile, based on 100 wt% of the copolymer. In paragraph 1 or 2, The above (C) polysiloxane-polycarbonate copolymer resin comprises a siloxane structural unit and a carbonate structural unit, and the siloxane structural unit is a thermoplastic resin composition represented by the following chemical formula 1: [Chemical Formula 1]

In the above chemical formula 1, R ³ and R ⁴ are, each independently, a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C3 to C30 cycloalkenyl group, a substituted or unsubstituted C3 to C30 cycloalkynyl group, a substituted or unsubstituted C6 to C30 aryloxy group, a substituted or unsubstituted C6 to C30 aryl group, or NRR' (wherein, R and R' are the same as or different from each other and are a hydrogen atom, or a substituted or unsubstituted C1 to C20 alkyl group), * is a connection point. In paragraph 3, The above (C) polysiloxane-polycarbonate copolymer resin is a thermoplastic resin composition containing 1 to 50 wt% of a siloxane structural unit represented by the chemical formula 1 based on 100 wt% of the copolymer resin. In any one of paragraphs 1 to 4, The above (C) polysiloxane-polycarbonate copolymer resin is a thermoplastic resin composition having a weight average molecular weight of 10,000 to 100,000 g/mol. In any one of paragraphs 1 to 5, The above (D) siloxane modified polyester is a thermoplastic resin composition represented by the following chemical formula 2: [Chemical formula 2]

In the above chemical formula 2, R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a C1 to C5 alkylene group, R ⁹ is a C1 to C4 alkyl group or a phenyl group, R ¹⁰ is hydrogen, hydroxyl group, or methyl group, l, m and n are each independently an integer greater than or equal to 1. In Article 6, A thermoplastic resin composition, wherein R ⁵ and R ⁶ of the above chemical formula 2 are each a propylene group, R ⁷ and R ⁸ are each a pentylene group, R ⁹ is a methyl group, and l, m and n are integers of 1 or more satisfying l + m : n = 15 to 20 : 25 to 35. In any one of paragraphs 1 to 7, The above (E) syndiotactic polystyrene is a thermoplastic resin composition having a syndiotacticity of 97 to 100%. In any one of paragraphs 1 to 8, The above (A) polycarbonate resin is a thermoplastic resin composition having a weight average molecular weight of 10,000 to 100,000 g/mol. In any one of paragraphs 1 to 9, A thermoplastic resin composition further comprising at least one additive selected from a flame retardant, a nucleating agent, a coupling agent, glass fiber, a plasticizer, a lubricant, a mineral filler, an antibacterial agent, a release agent, a heat stabilizer, an antioxidant, a pigment, a dye, and an antistatic agent. A molded product manufactured from a thermoplastic resin composition according to any one of claims 1 to 10. In Article 11, The above molded product is a molded product having a notched Izod impact strength of 15 kgf·cm/cm or more as measured in accordance with ASTM D256 for a 1/8 inch thick specimen. In Article 11 or 12, The above molded product is a molded product having a brightness (L*) of 2.0 or less when measured in the specular reflection removal mode according to ASTM E308 on a black 2.5 mm thick specimen. In any one of Articles 11 to 13, The above molded product is a molded product in which the brightness change (ΔL*) before and after the scratch resistance evaluation measured using an Erichsen Scratch Hardness Tester 430 P-I on a black specimen is 2.5 or less.