KR102412139B1 - Thermoplastic resin composition with improved solidification rate and molded article comprising the same - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition having an improved solidification rate and a molded article comprising the same, and more particularly, to an acrylonitrile-butadiene-styrene (ABS) resin, a polybutylene terephthalate (PBT) resin, or a polyethylene terephthalate (PET) resin. ) Resin, epoxy group-containing polymer, and ABS graft copolymer in a specific content, thereby exhibiting an improved solidification rate as well as excellent mechanical properties and injection moldability. .

Description

Thermoplastic resin composition with improved solidification rate and molded article comprising the same

The present invention relates to a thermoplastic resin composition having an improved solidification rate and a molded article comprising the same, and more particularly, to an acrylonitrile-butadiene-styrene (ABS) resin, a polybutylene terephthalate (PBT) resin, or a polyethylene terephthalate (PET) resin. ) Resin, epoxy group-containing polymer, and ABS graft copolymer in a specific content, thereby exhibiting an improved solidification rate as well as excellent mechanical properties and injection moldability. .

The ABS-based copolymer containing acrylonitrile-butadiene-styrene (ABS) has relatively good physical properties such as formability and gloss as well as mechanical strength such as impact resistance, so that electrical parts, electronic parts, It is widely used in office equipment or automobile parts, and its usage is gradually increasing. However, acrylonitrile-butadiene-styrene (ABS), a thermoplastic resin, has a disadvantage in that its solidification rate is slower than that of other resins, resulting in poor moldability during injection.

It is known that mechanical properties and compatibility of ABS/PBT and ABS/PET alloys are improved when SAG-002, one of the compatibilizers, is used. , there is a problem that the cooling time after injection is long because the solidification rate is not sufficiently shortened.

Accordingly, additional research is needed, and there is a need for development of an ABS-based alloy resin composition having sufficiently improved mechanical properties and at the same time having a shortened solidification rate and excellent moldability.

The present invention is to solve the problems of the prior art, acrylonitrile-butadiene-styrene (ABS) resin, polybutylene terephthalate (PBT) resin or polyethylene terephthalate (PET) resin, epoxy group-containing polymer and ABS It is a technical task to provide a thermoplastic resin composition, which is an ABS-based alloy resin composition, which exhibits an improved solidification rate as well as excellent mechanical properties and injection moldability by including the graft copolymer in a specific content, and a molded article including the same.

In order to achieve the above technical problem, the present invention provides an acrylonitrile-butadiene-styrene (ABS) resin in an amount of 30 to 80% by weight, based on 100% by weight of the total composition; 5 to 60% by weight of polybutylene terephthalate (PBT) resin, polyethylene terephthalate (PET) resin, or mixtures thereof; It provides a thermoplastic resin composition comprising 1 to 6% by weight of the epoxy group-containing polymer and 6 to 20% by weight of the ABS graft copolymer.

According to another aspect of the present invention, there is provided a molded article including the thermoplastic resin composition of the present invention.

The hardness (at 20 seconds after injection) measured by the shore hardness tester (D type) of the molded article made of the thermoplastic resin composition of the present invention is 7 to 30 HS, and improved solidification rate and injection compared to the conventional ABS-based resin composition Shows moldability. In addition, since the molded article of the present invention has excellent mechanical properties, such as showing an impact strength of 15 to 30 kgf * cm / cm, it can be applied to electric parts, electronic parts, office equipment or automobile parts.

1 shows the specimens of Comparative Example (ABS), Example 2 (ABS/PBT20wt%) and Example 5 (ABS/PBT50wt%) prepared in Examples of the present invention.
2 is a sample of Comparative Example (ABS), Example 2 (PBT20wt%), Example 3 (PBT30wt%), Example 4 (PBT40wt%) and Example 5 (PBT50wt%) prepared in Examples of the present invention It is a photograph comparing the difference in the solidification rate of each specimen after manufacturing.
Figure 3 shows the shore hardness tester used in the embodiment of the present invention.

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

The thermoplastic resin composition of the present invention, based on 100% by weight of the total composition, 30 to 80% by weight of an acrylonitrile-butadiene-styrene (ABS) resin; 5 to 60% by weight of polybutylene terephthalate (PBT) resin, polyethylene terephthalate (PET) resin, or mixtures thereof; 1 to 6% by weight of the epoxy group-containing polymer and 6 to 20% by weight of the ABS graft copolymer.

As used herein, “solidification time” and “solidification rate” refer to the time during which the melt is solidified in the mold after injection and solidified to a state that can be released without deformation of the external shape. it means.

(1) acrylonitrile-butadiene-styrene (ABS) resin

The thermoplastic resin composition of the present invention may include an acrylonitrile-butadiene-styrene (ABS) resin as a thermoplastic resin.

The content of the acrylonitrile-butadiene-styrene (ABS) resin used in the present invention may be 30 wt% or more, 31 wt% or more, 32 wt% or more, or 33 wt% or more, based on 100 wt% of the total composition, 80 weight % or less, 79.5 wt% or less, 79 wt% or less, 78.5 wt% or less, or 78 wt% or less, for example 30 to 80 wt%, 31 to 79 wt% or 33 to 78 wt% . When the content of the acrylonitrile-butadiene-styrene (ABS) resin is less than the above range, there may be a problem in that mechanical strength is lowered. Conversely, if the content of the acrylonitrile-butadiene-styrene (ABS) resin is higher than the above range, the solidification rate may be lowered and injection moldability may be deteriorated.

(2) polybutylene terephthalate (PBT) resin, polyethylene terephthalate (PET) resin, or mixtures thereof

In addition to the ABS resin, the thermoplastic resin composition of the present invention may include a polybutylene terephthalate (PBT) resin, a polyethylene terephthalate (PET) resin, or a mixture thereof as a thermoplastic resin.

The content of the PBT resin, PET resin, or mixture thereof used in the present invention may be 5 wt% or more, 6 wt% or more, 8 wt% or more, or 10 wt% or more, based on 100 wt% of the total composition, and 60 wt% or less, 58 wt% or less, 55 wt% or less, 52 wt% or less, or 50 wt% or less, for example, 5 to 60 wt%, 6 to 55 wt%, or 10 to 50 wt%. If the content of the PBT resin, PET resin, or a mixture thereof is less than the above range, the solidification rate may be lowered and injection moldability may be deteriorated.

(3) Epoxy group-containing polymer

The thermoplastic resin composition of the present invention may include an epoxy group-containing polymer as a compatibilizer.

Although not particularly limited, the epoxy group-containing polymer of the present invention is a polymer comprising at least one monomer selected from the group consisting of glycidyl acrylic acid, glycidyl acrylate, glycidyl methacrylate and glycidyl methacrylic acid, or It may be a copolymer.

In one embodiment, the epoxy group-containing polymer may be a styrene-acrylonitrile-glycidyl methacrylate (SAN-GMA) copolymer having a structure represented by the following Chemical Formula 1:

[Formula 1]

The content of the epoxy group-containing polymer used in the present invention may be 1 wt% or more, 1.2 wt% or more, 1.5 wt% or more, or 1.8 wt% or more, 6 wt% or less, 5 wt% or less, based on 100 wt% of the total composition , 4 wt% or less, 3 wt% or less, or 2.5 wt% or less, for example, 1 to 6 wt%, 1.5 to 4 wt%, or 1.8 to 2.5 wt%. If the content of the epoxy group-containing polymer is less than the above range, mechanical properties and injection moldability may be reduced, and on the contrary, if it is more than the above range, it is difficult to expect additional effects.

(4) ABS graft copolymer

The thermoplastic resin composition of the present invention may include an ABS graft copolymer.

The ABS graft copolymer used in the present invention may be prepared by emulsion polymerization, but is not particularly limited, but may have a butadiene content of 50 to 70% by weight and a volume average rubber particle size of 0.1 to 0.3 μm.

The content of the ABS graft copolymer used in the present invention may be 6 wt% or more, 7 wt% or more, 8 wt% or more, or 10 wt% or more, 20 wt% or less, 19 wt% based on 100 wt% of the total composition % or less, 18 wt% or less, 16 wt% or less, or 15 wt% or less, for example, 6 to 20 wt%, 8 to 16 wt%, or 10 to 15 wt%. When the content of the ABS graft copolymer is less than the above range, mechanical properties, particularly impact strength, may be significantly reduced.

(5) other additives

The thermoplastic resin composition of the present invention, in addition to the above-mentioned components (1) to (4), may further include one or more other additives commonly added to the thermoplastic resin composition for injection molding or extrusion molding. The resin composition of the present invention is, for example, one selected from the group consisting of inorganic particles, light diffusing agents, antioxidants, lubricants, ultraviolet absorbers, light stabilizers, impact modifiers, matting agents, flame retardants, or mixtures of two or more thereof The above additives may be further included.

Specifically, as the inorganic particle component included in the thermoplastic resin composition of the present invention, glass particles, mica, graphite, talc, pearl particles, wollastonite, TiO ₂ or a combination thereof may be used, preferably TiO ₂ can be used

The inorganic particles may have an average particle diameter of 10 to 200 μm, preferably 10 to 180 μm, more preferably 10 to 150 μm, more preferably 10 to 120 μm, even more preferably 10 to 100 μm, and , the thickness may be 0.1 to 10 μm, preferably 0.3 to 10 μm, more preferably 0.5 to 9 μm, still more preferably 1.0 to 8.5 μm, even more preferably 1.0 to 8 μm.

Specifically, the light diffusing agent may be a silicone-based light diffusing agent, an acrylic light diffusing agent, a polystyrene-based light diffusing agent, or a mixture of two or more thereof.

Specifically, as the antioxidant, phenol-based, phosphite-based, thioester-based, or a mixture of two or more thereof may be used.

Specifically, as the lubricant, polyethylene-based, ethylene-ester-based, ethylene glycol-glycerin ester-based, montan-based, ethylene glycol-glycerin-montanic acid ester-based lubricant, or a mixture of two or more thereof may be used.

The ultraviolet absorber is not particularly limited, and commercially available products may be used.

Specifically, as the light stabilizer, a benzotriazole-based compound, a hydroxyphenyltriazine-based compound, a pyrimidine-based compound, a cyanoacrylate-based compound, or a mixture of two or more thereof may be used.

Specifically, as the impact modifier, at least one core-shell structure copolymer selected from an acrylate-based copolymer, an ethylene-acrylate-based copolymer, a silicone-containing copolymer, or a polyalkyl methacrylate-based copolymer may be used. However, the present invention is not limited thereto. The impact modifier may perform a function of stabilizing excellent and uniform physical properties by improving compatibility between resins or components in the composition as well as the function of impact reinforcement.

Specifically, an inorganic compound or an organic compound may be used as the matting agent, and silica, magnesium oxide, zirconia, alumina, titania, or a mixture of two or more thereof may be used as the inorganic compound, and the organic compound is cross-linked A vinyl-based copolymer may be used, and the monomer of the vinyl-based copolymer is at least one monomer selected from styrene, acrylonitrile, methyl (meth) acrylate, ethyl (meth) acrylate or butyl (meth) acrylate. can be

Specifically, the flame retardant may include at least one of a phosphate compound, a phosphonate compound, a polysiloxane, a phosphazene compound, a phosphinate compound, or a melamine-based compound, which is a material that reduces combustibility, but is not limited thereto .

The content of the other additives is not particularly limited, and is an amount that can be used to add additional functions within a range that does not impair the desired physical properties of the thermoplastic resin composition of the present invention.

According to one embodiment of the present invention, the content of other additives may be 0.1 to 5% by weight, preferably 0.5 to 2% by weight, based on 100% by weight of the thermoplastic resin composition of the present invention. When the content of the other additives is less than 0.1% by weight, the effect of improving various functions according to the use of the other additives may be insignificant, and when the content of the other additives is more than 5% by weight, mechanical properties may be poor.

According to another aspect of the present invention, there is provided a molded article including the thermoplastic resin composition of the present invention.

The molded article may be manufactured by extruding or injection molding the thermoplastic resin composition of the present invention. In one embodiment, the thermoplastic resin composition of the present invention is 150 ° C. to 300 ° C., such as 220 ° C. to 240 ° C. and 100 rpm to 300 rpm, such as 200 rpm to 250 rpm conditions in a 32 pie twin screw extruder (L / D = 39) , 25 mm) can be used for extrusion, and an injection specimen can be prepared using an injection machine having a clamping force of 100 tons to 200 tons under the same temperature conditions as above.

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples. However, the scope of the present invention is not limited thereto.

[Example]

Example 1

Acrylonitrile-butadiene-styrene (ABS) resin 78 wt%, Polybutylene terephthalate (PBT) resin 10 wt%, Epoxy group-containing polymer (Compatibilizer, SAG-002, Fine- Blend company) 2.0 wt%, ABS graft copolymer (G-ABS) 10.0 wt% mixture is extruded into a twin-screw extruder with L/D of 39 and screw diameter of 25mm as a ZSK-25 model from W&P, with a die temperature of 240°C. Pellets were prepared by mixing and extruding under the conditions of a rotation speed of 200 rpm and a discharge amount of 15 kg/hr.

The ABS graft copolymer (G-ABS) (LG Chem's DP270 was used, which was prepared by emulsion polymerization, butadiene content was 60 wt%, and the volume average rubber particle size was 0.3 µm.

In the case of injection specimens for measuring the solidification rate, the specimens were prepared in the form of rods with a size of 127 mm × 12.7 mm × 6.4 mm, and after injection using a Shore hardness tester-D, from 0 to 40 seconds in units of 10 seconds. The hardness was measured with a furnace (based on 20 seconds after injection). In the case of injection specimens for measuring mechanical properties, injection specimens meeting each ASTM standard were prepared to be suitable for measurement of tensile strength, flexural strength, and impact strength.

Examples 2 to 8

An injection specimen was prepared in the same manner as in Example 1, except that the ABS, PBT, PET resin and ABS graft copolymer contents were changed as described in Table 1.

Comparative Examples 1 to 16

An injection specimen was prepared in the same manner as in Example 1, except that the contents of the thermoplastic resin, ABS graft copolymer, compatibilizer and impact modifier were changed as described in Tables 2 and 3.

The physical properties of the 　 injection 　 specimens prepared from the thermoplastic resin compositions of Examples 1 to 8 and Comparative Examples 1 to 16 are shown in Tables 1 to 3. In addition, the specimens of Comparative Example (ABS), Example 2 (ABS/PBT20wt%) and Example 5 (ABS/PBT50wt%) among the prepared specimens are shown in FIG. 1, Comparative Example (ABS), Example 2 ( After preparing the specimens of PBT20wt%), Example 3 (PBT30wt%), Example 4 (PBT40wt%) and Example 5 (PBT50wt%), a photograph comparing the difference in the solidification rate of each specimen is shown in FIG. it was

As can be seen in FIGS. 1 and 2 , when the injected specimen is directly placed between the upper plate and lower plate jig (JIG) having a constant weight, the comparative example, which is a single ABS specimen, is slow to solidify and bends considerably, and the PBT resin is made of Alloy It can be seen that the degree of bending of the specimens of the present invention is different for each content.

In addition, the shore hardness tester used in Examples of the present invention is shown in FIG. 3 .

<Evaluation of physical properties>

(1) Tensile strength

Tensile strength was measured in accordance with ASTM D638 for 　 injection 　 specimens prepared from the thermoplastic resin compositions of Examples 1 to 8 and Comparative Examples 1 to 16.

(2) Flexural strength

Flexural strength was measured in accordance with ASTM D760 for 　 injection 　 specimens prepared from the thermoplastic resin compositions of Examples 1 to 8 and Comparative Examples 1 to 16.

(3) Impact strength

Impact strength (Izod Notched type) was measured according to ASTM D256 for the 　 injection 　 specimens prepared from the thermoplastic resin compositions of Examples 1 to 8 and Comparative Examples 1 to 16.

(4) solidification properties

For the 　 injection 　 specimens prepared from the thermoplastic resin compositions of Examples 1 to 8 and Comparative Examples 1 to 16, using a shore hardness tester (Shore hardness tester-D) was quantified in units of 10 seconds.

[Table 1]

[Table 2]

[Table 3]

As can be seen in Table 1 above, acrylonitrile-butadiene-styrene (ABS) resin, polybutylene terephthalate (PBT) resin or polyethylene terephthalate (PET) resin, epoxy group-containing polymer and ABS graft copolymer In Examples 1 to 8 containing a specific content, it was confirmed that not only exhibited an improved solidification rate but also excellent mechanical properties and injection moldability.

However, Comparative Example 1 containing only the ABS resin showed a shore hardness D of 4.8 even after 20 seconds of injection, and was in a very soft state (that is, the solidification rate was very low), and as in Comparative Examples 2 to 6, the ABS graft copolymer (G In the case of a composition containing ABS/PBT/SAG-002 without -ABS), even if the impact strength is improved by adding an impact reinforcing material, it has an impact strength of about 5.5 to 11 kgf*cm/cm, practice including PBT It was confirmed that the impact strength was significantly lowered compared to Examples 1 to 5. In addition, in Comparative Example 7 having a low ABS resin content, it was confirmed that the impact strength was lowered.

In addition, as in Comparative Examples 8 to 10, the composition including ABS/PET/SAG-002 without G-ABS exhibited significantly lower impact strength compared to Examples 6 to 8 including PET, even when an impact reinforcing material was added. In addition, in the case of Comparative Examples 11 and 12 having a low G-ABS content in ABS/PBT/SAG-002, the impact strength was lower than that of Examples 1 to 4.

In addition, as in Comparative Example 13, when only G-ABS was included without including the epoxy group-containing polymer (SAG-002), the impact strength was lowered, and in Comparative Example 14 in which the ABS graft copolymer was excessive, additional effects could be confirmed. there was no In addition, in the case of the compositions (Comparative Examples 15 and 16) containing a large amount of SAG-002 without including G-ABS, the impact strength was significantly reduced even when an impact modifier was added, and the melt index was also significantly higher than that of Examples, and the solidification rate was significantly higher than in Examples. can be seen to be poor. That is, in order for the ABS/PBT or PET alloy composition to have sufficient impact strength and a rapid solidification rate from this, either the epoxy group-containing polymer (SAG-002) or the ABS graft copolymer (G-ABS) It was confirmed that it is not enough just to include the

Claims (8)

Based on 100% by weight of the total composition,
33 to 68% by weight of an acrylonitrile-butadiene-styrene (ABS) resin;
20 to 50% by weight of polybutylene terephthalate (PBT) resin, polyethylene terephthalate (PET) resin, or mixtures thereof;
1.8 to 2.5 wt% of an epoxy group-containing polymer, and
ABS graft copolymer comprising 10 to 15% by weight,
Thermoplastic resin composition. The polymer or copolymer according to claim 1, wherein the epoxy group-containing polymer comprises at least one monomer selected from the group consisting of glycidyl acrylic acid, glycidyl acrylate, glycidyl methacrylate and glycidyl methacrylic acid. Chain, thermoplastic resin composition. The thermoplastic resin composition according to claim 1, wherein the epoxy group-containing polymer has a structure represented by the following formula (1):
[Formula 1]

The thermoplastic resin composition according to claim 1, wherein the butadiene content of the ABS graft copolymer is 50 to 70 wt%. The thermoplastic resin composition of claim 1, wherein the volume average rubber particle size of the ABS graft copolymer is 0.1 to 0.3 μm. The method of claim 1, further comprising an additive selected from the group consisting of inorganic particles, light diffusing agents, antioxidants, lubricants, ultraviolet absorbers, light stabilizers, impact modifiers, matting agents, flame retardants, or mixtures of two or more thereof. , a thermoplastic resin composition. A molded article comprising the thermoplastic resin composition according to any one of claims 1 to 6. The molded article according to claim 7, wherein the impact strength is 15 to 30 kgf*cm/cm, and the hardness (at 20 seconds after injection) measured with a shore hardness tester (D type) is 7 to 30 HS.

Images