WO2022182013A1 - Thermoplastic resin composition and molded article formed therefrom - Google Patents

Abstract

A thermoplastic resin composition of the present invention comprises: polycarbonate resin; polycarbonate-polysiloxane copolymer resin; and a polydimethylsiloxane oil having a kinematic viscosity of from about 50 cSt to about 70,000 cSt, wherein a polycarbonate block of the polycarbonate resin and the polycarbonate-polysiloxane copolymer resin has a continuous phase, a polysiloxane block of the polycarbonate-polysiloxane copolymer resin and the polydimethylsiloxane oil have a dispersed phase, and the maximum particle diameter of the dispersed phase is about 0.01 μm to about 0.5 μm. The thermoplastic resin composition has excellent low-temperature impact resistance, chemical resistance, molding processability, and the like.

Description

Thermoplastic resin composition and molded article prepared therefrom

The present invention relates to a thermoplastic resin composition and a molded article prepared therefrom. More specifically, the present invention relates to a thermoplastic resin composition having excellent low-temperature impact resistance, chemical resistance, molding processability, and the like, and a molded article prepared therefrom.

Polycarbonate resin has excellent impact resistance, toughness, transparency, thermal stability, self-extinguishing property, dimensional stability, etc. However, when applied to products requiring transparency, conventional polycarbonate resins have problems such as very poor scratch resistance compared to glass materials.

Accordingly, there is a need for a post-injection painting process to prevent life scratches and realize various colors, clear coating or to secure an appearance. In this case, after diluting the coating solution and paint with various organic solvents, the surface of the resin product After applying it, it goes through a drying process. However, organic solvents used as diluents in this process penetrate into the polycarbonate resin and act as a cause of lowering impact resistance and mechanical properties.

Therefore, there is a need for the development of a thermoplastic resin composition having excellent low-temperature impact resistance, chemical resistance, molding processability, and balance of physical properties thereof.

Background art of the present invention is disclosed in Korean Patent Publication No. 10-2010-0076643 and the like.

An object of the present invention is to provide a thermoplastic resin composition having excellent low-temperature impact resistance, chemical resistance, molding processability, and the like.

Another object of the present invention is to provide a molded article formed from the thermoplastic resin composition.

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

1. One aspect of the present invention relates to a thermoplastic resin composition. The thermoplastic resin composition comprises about 10 to about 90 wt% of a polycarbonate resin; about 10 to about 90 weight percent of a polycarbonate-polysiloxane copolymer resin; And, based on about 100 parts by weight of the polycarbonate resin and polycarbonate-polysiloxane copolymer resin, based on ASTM D445, a polydimethylsiloxane oil having a kinematic viscosity of about 50 to about 70,000 cSt measured at 40° C. from about 0.3 to about 2.5 weight part; wherein the polycarbonate resin and the polycarbonate-polycarbonate block of the polysiloxane copolymer resin are a continuous phase, and the polycarbonate-polysiloxane block of the polysiloxane copolymer resin and the polydimethylsiloxane oil are a dispersed phase, and transmit electrons It is characterized in that the maximum particle diameter of the dispersed phase measured under a microscope is about 0.01 to about 0.5 μm.

2. In the first embodiment, the polycarbonate resin may have a weight average molecular weight of about 20,000 to about 50,000 g/mol.

3. In embodiment 1 or 2, the polycarbonate-polysiloxane copolymer resin may include from about 1 to about 10% by weight of a polysiloxane block and from about 90 to about 99% by weight of a polycarbonate block.

4. In the above 1 to 3 embodiments, the polycarbonate-polysiloxane copolymer resin may have a weight average molecular weight of about 15,000 to about 50,000 g/mol.

5. In the above 1 to 4 embodiments, the thermoplastic resin composition has a notch Izod impact strength of about 40 to about 60 kgf·cm/cm of a thickness 1/4″ specimen measured at -30°C according to ASTM D256 can

6. In the above 1 to 5 embodiments, the thermoplastic resin composition is obtained by immersing a 2 mm thick specimen in a thinner solution for 2 minutes and 30 seconds, drying it at 80° C. for 20 minutes, leaving it at room temperature for 24 hours, and then 4 kg of The height at which the specimen is destroyed, measured by impact with a falling weight evaluation device of the DuPont drop test method using a weight, may be about 60 to about 90 cm.

7. Another aspect of the present invention relates to a molded article. The molded article is characterized in that it is formed from the thermoplastic resin composition according to any one of 1 to 6.

The present invention has the effect of providing a thermoplastic resin composition excellent in low-temperature impact resistance, chemical resistance, molding processability, and the like, and a molded article formed therefrom.

Hereinafter, the present invention will be described in detail as follows.

The thermoplastic resin composition according to the present invention comprises (A) a polycarbonate resin; (B) polycarbonate-polysiloxane copolymer resin; and (C) polydimethylsiloxane oil.

In the present specification, "a to b" representing a numerical range is defined as "≥a and ≤b".

(A) polycarbonate resin

As the polycarbonate resin according to an embodiment of the present invention, a polycarbonate resin used in a conventional thermoplastic resin composition may be used. For example, an aromatic polycarbonate resin produced by reacting diphenols (aromatic diol compounds) with a precursor such as phosgene, halogen formate or diester carbonate can be used.

In an embodiment, the diphenols include 4,4'-biphenol, 2,2-bis(4-hydroxyphenyl)propane, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1 , 1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, and the like may be exemplified, but the present invention is not limited thereto. . For example, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4- Hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane or 1,1-bis(4-hydroxyphenyl)cyclohexane may be used, and specifically, bisphenol- It is possible to use 2,2-bis(4-hydroxyphenyl)propane called A.

In an embodiment, the polycarbonate resin may be one having a branched chain, for example, based on the total amount of diphenols used for polymerization, from about 0.05 to about 2 mol% of a trivalent or higher polyfunctional compound, specifically , a branched polycarbonate resin prepared by adding a compound having a trivalent or higher phenol group may be used.

In an embodiment, the polycarbonate resin may be used in the form of a homo polycarbonate resin, a copolycarbonate resin, or a blend thereof. In addition, the polycarbonate resin may be partially or entirely replaced with an aromatic polyester-carbonate resin obtained by polymerization in the presence of an ester precursor, for example, a bifunctional carboxylic acid.

In an embodiment, the polycarbonate resin may have a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of about 20,000 to about 50,000 g/mol, for example, about 25,000 to about 40,000 g/mol. In the above range, the thermoplastic resin composition may have excellent impact resistance, fluidity (processability), and the like.

In an embodiment, the polycarbonate resin is about 10 to about 90 wt%, for example, about 20 wt%, based on 100 wt% of the polycarbonate resin (A) and the polycarbonate-polysiloxane copolymer resin (B) total (A+B) to about 80% by weight. When the content of the polycarbonate resin is less than about 10% by weight, there is a fear that the molding processability (exfoliation, discoloration, etc., occur during molding) and chemical resistance of the thermoplastic resin composition may decrease, and when it exceeds about 90% by weight , there is a fear that the low-temperature impact resistance, chemical resistance, etc. of the thermoplastic resin composition may decrease.

(B) polycarbonate-polysiloxane copolymer resin

The polycarbonate-polysiloxane copolymer resin according to an embodiment of the present invention is applied together with the polycarbonate resin, polydimethylsiloxane oil, etc. to improve the low-temperature impact resistance, chemical resistance, molding processability, etc. of the thermoplastic resin composition. , polysiloxane blocks and polycarbonate blocks.

In an embodiment, the polycarbonate block may include a structural unit derived from the aforementioned polycarbonate resin (A), and the polysiloxane block may include a structural unit represented by Formula 1 below.

[Formula 1]

In Formula 1, R ₁ and R ₂ are each independently a hydrogen atom, C1 to C20 alkyl group, C2 to C20 alkenyl group, C2 to C20 alkynyl group, C1 to C20 alkoxy group, C3 to C30 cycloalkyl group, C3 to C30 a cycloalkenyl group, a C3 to C30 cycloalkynyl group, a C6 to C30 aryl group, a C6 to C30 aryloxy group, or NRR′ (wherein R and R′ are each independently a hydrogen atom or a C1 to C20 alkyl group); , m (average degree of polymerization) is from about 10 to about 150.

In an embodiment, the average degree of polymerization of the polysiloxane block may be from about 10 to about 150, for example, from about 20 to about 100. Within the above range, the thermoplastic resin composition may have excellent chemical resistance, low temperature impact resistance, and the like.

In an embodiment, the polycarbonate-polysiloxane copolymer resin may be prepared according to a conventional polycarbonate-polysiloxane copolymer preparation method. For example, it can be prepared by reacting polysiloxane containing the structural unit represented by Formula 1 and diphenols (aromatic diol compound) with a precursor such as phosgene, halogen formate, or diester carbonate. The reaction may be carried out by a conventional polymerization method such as interfacial polymerization and melt polymerization, for example, may be carried out by interfacial polymerization using phosgene.

In an embodiment, the polycarbonate-polysiloxane copolymer resin comprises from about 1 to about 10% by weight of a polysiloxane block, for example from about 1 to about 7% by weight, specifically from about 4 to about 6% by weight, and from about 90 to about 90% by weight of a polycarbonate block. about 99% by weight, for example about 93 to about 99% by weight, specifically about 94 to about 96% by weight. Within the above range, the low-temperature impact resistance and chemical resistance of the thermoplastic resin composition may be excellent.

In an embodiment, the polycarbonate-polysiloxane copolymer resin has a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of about 15,000 to about 50,000 g/mol, for example, about 15,000 to about 40,000 g/mol. can In the above range, molding processability, chemical resistance, etc. of the thermoplastic resin composition may be excellent.

In an embodiment, the polycarbonate-polysiloxane copolymer resin is from about 10 to about 90 wt% of the total (A + B) 100 wt% of the polycarbonate resin (A) and the polycarbonate-polysiloxane copolymer resin (B), for example For example, it may be included in an amount of about 20 to about 80% by weight. When the content of the polycarbonate-polysiloxane copolymer resin is less than about 10% by weight, there is a risk that the chemical resistance, low-temperature impact resistance, etc. of the thermoplastic resin composition may be deteriorated, and when it exceeds about 90% by weight, molding of the thermoplastic resin composition There is a possibility that the workability (during the molding process, peeling, discoloration, etc. occur), chemical resistance, etc. may be deteriorated.

(C) polydimethylsiloxane oil

The polydimethylsiloxane oil according to an embodiment of the present invention may be distributed at the interface between the polycarbonate resin and the polycarbonate-polysiloxane copolymer resin, and in the thermoplastic resin composition, the polycarbonate resin is a continuous phase (matrix), the When the polycarbonate-polysiloxane copolymer resin forms a morphology in which the dispersed phase (domain) is formed, the maximum particle diameter of the dispersed phase can be adjusted to about 0.01 to about 0.5 μm, and the low-temperature impact resistance, chemical resistance, and molding processability of the thermoplastic resin composition etc. can be improved.

In an embodiment, the polydimethylsiloxane oil may have a kinematic viscosity of about 50 to about 70,000 cSt, for example, about 100 to about 60,000 cSt, measured at 40°C, based on ASTM D445. When the kinematic viscosity of the polydimethylsiloxane oil is less than about 50 cSt, there is a fear that the low-temperature impact resistance of the thermoplastic resin composition may decrease, and if it exceeds about 70,000 cSt, the molding processability of the thermoplastic resin composition may decrease. .

In an embodiment, the polydimethylsiloxane oil is about 0.3 to about 2.5 parts by weight, for example, based on about 100 parts by weight of the polycarbonate resin (A) and the polycarbonate-polysiloxane copolymer resin (B) total (A + B) For example, it may be included in an amount of about 0.5 to about 2 parts by weight. When the content of the polycarbonate-polysiloxane copolymer resin is less than about 0.3 parts by weight, there is a fear that the low-temperature impact resistance and chemical resistance of the thermoplastic resin composition may be lowered, and when it exceeds about 2.5 parts by weight, the low-temperature resistance of the thermoplastic resin composition Impact resistance, chemical resistance, molding processability, etc. may be deteriorated.

The thermoplastic resin composition according to an embodiment of the present invention may further include an additive included in a conventional thermoplastic resin composition. The additive may include, but is not limited to, a flame retardant, a filler, an antioxidant, an anti-drip agent, a lubricant, a mold release agent, a nucleating agent, a stabilizer, a pigment, a dye, and mixtures thereof. When the additive is used, the content is about 0.001 to about 40 parts by weight, for example, based on about 100 parts by weight of the total (A + B) of the polycarbonate resin (A) and the polycarbonate-polysiloxane copolymer resin (B) It may be about 0.1 to about 10 parts by weight.

In the thermoplastic resin composition according to an embodiment of the present invention, the polycarbonate block of the polycarbonate-polysiloxane copolymer resin is a continuous phase, and the polysiloxane block of the polycarbonate-polysiloxane copolymer resin and the polydimethylsiloxane oil have a morphology of a dispersed phase. The injection specimen was cut to a thickness of 150 nm by microtomming, and after dyeing with osmium tetroxide, the maximum particle diameter of the dispersed phase (the particle diameter of the dispersed phase having the maximum size) measured with a transmission electron microscope was about 0.01 to about 0.5 μm, for example about 0.05 to about 0.4 μm. When the maximum particle diameter of the dispersed phase exceeds about 0.5 μm, there is a fear that the low-temperature impact resistance and molding processability of the thermoplastic resin composition may be deteriorated.

In an embodiment, the thermoplastic resin composition may be in the form of pellets that are melt-extruded at about 200 to about 280°C, for example, about 250 to about 260°C, by mixing the components and using a conventional twin-screw extruder.

In an embodiment, the thermoplastic resin composition has a notch Izod impact strength of about 40 to about 60 kgf·cm/cm, for example, about 40 to about 1/4″ thick specimen measured at -30°C according to ASTM D256 It may be about 50 kgf·cm/cm.

In an embodiment, the thermoplastic resin composition is a 2 mm thick specimen immersed in a thinner solution for 2 minutes and 30 seconds, dried at 80° C. for 20 minutes, left at room temperature for 24 hours, and then DuPont drop test using a 4 kg weight. (Dupont drop test) The height at which the specimen is destroyed by impact with a falling weight evaluation device may be about 60 to about 90 cm, for example, about 61 to about 80 cm.

The molded article according to the present invention is formed from the thermoplastic resin composition. For example, it can be manufactured from the thermoplastic resin composition through various molding methods such as injection molding, extrusion molding, vacuum molding, casting molding, and the like. Such a molding method is well known by those of ordinary skill in the art to which the present invention pertains. Since the molded article is excellent in low-temperature impact resistance, chemical resistance, molding processability, and the balance of these properties, it is useful as an interior/exterior material for automobile parts or electrical and electronic products. In particular, it can be used for interior/exterior materials such as mobile phones and notebook computers that include a painting process.

Hereinafter, the present invention will be described in more detail through examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example

Hereinafter, the specifications of each component used in Examples and Comparative Examples are as follows.

(A) polycarbonate resin

Bisphenol-A-based polycarbonate resin (manufacturer: Lotte Chemical, weight average molecular weight: 25,000 g/mol) was used.

(B) polycarbonate-polysiloxane copolymer resin

A polycarbonate-polysiloxane copolymer resin having an average degree of polymerization of the polysiloxane block of 50 (manufacturer: Lotte Chemical, Si content: 5 wt%, weight average molecular weight: 21,248 g/mol) was used.

(C) polydimethylsiloxane

(C1) Polydimethylsiloxane oil (manufacturer: Momentive, product name: Element14 PDMS 100, kinematic viscosity: 100 cSt) was used.

(C2) Polydimethylsiloxane oil (manufacturer: Dow, product name: DC200-A, kinematic viscosity: 60,000 cSt) was used.

(C3) Polydimethylsiloxane (manufacturer: Momentive, product name: Element14 PDMS 10, kinematic viscosity: 10 cSt) was used.

(C4) Polydimethylsiloxane (manufacturer: Dow, product name: Dowsil 4-7081, kinematic viscosity: 150,000 cSt) was used.

Examples 1 to 6 and Comparative Examples 1 to 7

After adding each of the components in the amounts as shown in Tables 1 and 2 below, extrusion was performed at 250° C. to prepare pellets. For extrusion, a twin-screw extruder with L/D=36 and a diameter of 45 mm was used, and the manufactured pellets were dried at 100°C for 4 hours or more, and then injected in a 6 oz injection machine (mold temperature: 60°C, molding temperature: 300°C). Specimens were prepared. The physical properties of the prepared specimens were evaluated by the following method, and the results are shown in Tables 1 and 2 below.

How to measure physical properties

(1) Low-temperature impact resistance evaluation: In accordance with ASTM D256, the notched Izod impact strength (unit: kgf·cm/cm) of a 1/4″ thick specimen at -30°C was measured.

(2) Evaluation of chemical resistance (impact resistance after painting): A 2 mm thick specimen is immersed in a thinner solution for 2 minutes and 30 seconds, dried at 80°C for 20 minutes, left at room temperature for 24 hours, and then a 4 kg weight is applied. The height (unit: cm) at which the specimen is destroyed was measured by impact with a falling weight evaluation device of the Dupont drop test method.

(3) Moldability evaluation: After injecting an injection product having a pin-gate structure with a thickness of 1 m, it was visually checked whether the surface was peeled off near the gate.

(4) Maximum particle diameter of dispersed phase (unit: ㎛): After cutting the injection specimen to a thickness of 150 nm by microtoming, dyeing it using osmium tetroxide, and a transmission electron microscope (manufacturer: JEOL, device name: JEM- 1400) to measure the particle size of the dispersed phase having the largest size.

Example One 2 3 4 5 6 (A) (wt%) 90 50 10 50 50 50 (B) (wt%) 10 50 90 50 50 50 (C1) (parts by weight) One One One 0.5 2 - (C2) (parts by weight) - - - - - One (C3) (parts by weight) - - - - - - (C4) (parts by weight) - - - - - - Notched Izod Impact Strength
(-30℃, kgf cm/cm) 40.2 46.8 40.2 42.9 47.5 47.8 Specimen breaking height (cm) 61.5 76.0 70.0 67.5 75.0 74.0 Whether peeling doesn't exist doesn't exist doesn't exist doesn't exist doesn't exist doesn't exist Dispersed phase maximum particle size (㎛) 0.16 0.14 0.14 0.14 0.18 0.2

* Parts by weight: parts by weight based on 100 parts by weight of the total (A+B) polycarbonate resin (A) and polycarbonate-polysiloxane copolymer resin (B)

comparative example One 2 3 4 5 6 7 (A) (wt%) 95 5 50 50 50 50 50 (B) (wt%) 5 95 50 50 50 50 50 (C1) (parts by weight) One One 0.1 3 - - - (C2) (parts by weight) - - - - 3 - - (C3) (parts by weight) - - - - - One - (C4) (parts by weight) - - - - - - One Notched Izod Impact Strength
(-30℃, kgf cm/cm) 25 42.6 28 22 25 37.7 45.2 Specimen breaking height (cm) 45.7 75.0 55.0 48.5 42.3 45.7 62.5 Whether peeling doesn't exist Occur doesn't exist Occur Occur doesn't exist Occur Dispersed phase maximum particle size (㎛) 0.32 0.55 0.09 2.2 2.7 0.1 3.0

* Parts by weight: parts by weight based on 100 parts by weight of the total (A+B) polycarbonate resin (A) and polycarbonate-polysiloxane copolymer resin (B)

From the above results, it can be seen that the thermoplastic resin composition of the present invention has excellent low-temperature impact resistance, chemical resistance, molding processability, and balance of physical properties thereof.

On the other hand, in the case of Comparative Example 1 in which the content of the polycarbonate resin exceeds the range of the present invention, and the content of the polycarbonate-polysiloxane copolymer resin is less than the range of the present invention, it can be seen that low-temperature impact resistance, chemical resistance, etc. are lowered and , It can be seen that in Comparative Example 2, wherein the content of the polycarbonate resin is less than the range of the present invention, and the content of the polycarbonate-polysiloxane copolymer resin exceeds the range of the present invention, molding processability and the like are reduced. In the case of Comparative Example 3 in which the content of polydimethylsiloxane oil is less than the range of the present invention, it can be seen that low-temperature impact resistance, chemical resistance, etc. are lowered, and Comparative Example 4 in which the content of polydimethylsiloxane oil exceeds the range of the present invention, In the case of 5, it can be seen that low-temperature impact resistance, chemical resistance, molding processability, etc. are lowered, and the maximum particle size of the dispersed phase is outside the scope of the present invention. In addition, in the case of Comparative Example 6 in which polydimethylsiloxane (C3) is applied instead of the polydimethylsiloxane oil of the present invention, it can be seen that low-temperature impact resistance and chemical resistance are reduced, and the polydimethylsiloxane (C4) is applied in Comparative Example In the case of 7, it can be seen that the molding processability and the like are lowered, and the maximum particle size of the dispersed phase is outside the scope of the present invention.

Up to now, the present invention has been mainly examined in the examples. Those of ordinary skill in the art to which the present invention pertains will understand that the present invention can be implemented in modified forms without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments are to be considered in an illustrative rather than a restrictive sense. The scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

Claims (7)

about 10 to about 90 weight percent polycarbonate resin; about 10 to about 90 weight percent of a polycarbonate-polysiloxane copolymer resin; and Based on about 100 parts by weight of the polycarbonate resin and the polycarbonate-polysiloxane copolymer resin, based on ASTM D445, about 0.3 to about 2.5 parts by weight of a polydimethylsiloxane oil having a kinematic viscosity of about 50 to about 70,000 cSt measured at 40° C. including; The polycarbonate resin and the polycarbonate-polycarbonate block of the polysiloxane copolymer resin are a continuous phase, and the polycarbonate-polysiloxane block of the polysiloxane copolymer resin and the polydimethylsiloxane oil are a dispersed phase, The thermoplastic resin composition, characterized in that the maximum particle diameter of the dispersed phase measured by a transmission electron microscope is about 0.01 to about 0.5 ㎛. The thermoplastic resin composition of claim 1, wherein the polycarbonate resin has a weight average molecular weight of about 20,000 to about 50,000 g/mol. The thermoplastic resin composition of claim 1 , wherein the polycarbonate-polysiloxane copolymer resin comprises from about 1 to about 10% by weight of a polysiloxane block and from about 90 to about 99% by weight of a polycarbonate block. The thermoplastic resin composition of claim 1, wherein the polycarbonate-polysiloxane copolymer resin has a weight average molecular weight of about 15,000 to about 50,000 g/mol. The method according to claim 1, wherein the thermoplastic resin composition has a notch Izod impact strength of about 40 to about 60 kgf·cm/cm, measured at -30°C at -30°C, according to ASTM D256. Thermoplastic resin composition. According to claim 1, wherein the thermoplastic resin composition is a 2 mm thick specimen immersed in a thinner solution for 2 minutes and 30 seconds, dried at 80 ° C. for 20 minutes, left at room temperature for 24 hours, and then left at room temperature for 24 hours, followed by DuPont using a weight of 4 kg. The thermoplastic resin composition, characterized in that the height at which the specimen is destroyed is about 60 to about 90 cm, measured by impact with a drop test equipment of a drop test method. A molded article, characterized in that it is formed from the thermoplastic resin composition according to any one of claims 1 to 6.