WO2021137489A1 - Thermoplastic resin composition and molded product formed therefrom - Google Patents

Abstract

A thermoplastic resin composition of the present invention comprises: about 100 parts by weight of an aromatic vinyl-cyanide vinyl-based copolymer resin; about 1 to about 13 parts by weight of a styrene-butadiene rubber polymer; and about 0.05 to about 5 parts by weight of a cyclohexyl (meth)acrylate copolymer. The thermoplastic resin composition is excellent in impact resistance, heat resistance, chemical resistance, transparency, and the like.

Description

Thermoplastic resin composition and molded article formed therefrom

The present invention relates to a thermoplastic resin composition and a molded article formed therefrom. More specifically, the present invention relates to a thermoplastic resin composition having excellent impact resistance, heat resistance, chemical resistance, transparency, and the like, and a molded article formed therefrom.

Tempered glass products used as exterior materials for electrical/electronic products have low impact strength and high specific gravity, making it difficult to reduce product weight. In order to overcome these disadvantages, a transparent resin has been applied instead of tempered glass products.

Transparency resins used in products requiring transparency include polycarbonate resins, transparent ABS resins, SAN resins, polystyrene resins, and PMMA resins. Polycarbonate resin has excellent transparency and impact resistance, but has disadvantages in that it is expensive and lacks scratch resistance and chemical resistance. Transparent ABS resins such as MABS resin can secure transparency and impact resistance, but scratch resistance , heat resistance, etc. are insufficient. In addition, SAN resins, polystyrene resins, and PMMA resins have excellent transparency and are inexpensive, but lack impact resistance, etc., and thus have limitations in use as exterior materials.

Therefore, there is a need to develop a transparent thermoplastic resin composition that can be used as an exterior material (replacement material for tempered glass products) for electrical/electronic products, etc. because it has excellent impact resistance, heat resistance, chemical resistance, transparency, and the like.

Background art of the present invention is disclosed in Korean Patent Publication No. 2007-0108008 and the like.

An object of the present invention is to provide a thermoplastic resin composition having excellent impact resistance, heat resistance, chemical resistance, transparency, 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 100 parts by weight of an aromatic vinyl-vinyl cyanide-based copolymer resin; about 1 to about 13 parts by weight of a styrene-butadiene rubbery polymer; and about 0.05 to about 5 parts by weight of the cyclohexyl (meth)acrylate copolymer.

2. In the first embodiment, the aromatic vinyl-vinyl cyanide copolymer resin is a polymer of a monomer mixture comprising about 50 to about 80 wt% of an aromatic vinylic monomer and about 20 to about 50 wt% of a vinyl cyanide monomer can

3. In the first or second embodiment, the aromatic vinyl-vinyl cyanide copolymer resin may have a weight average molecular weight of about 100,000 to about 400,000 g/mol as measured by gel permeation chromatography (GPC).

4. In the above 1 to 3 embodiments, the styrene-butadiene rubbery polymer may be a polymer of about 50 to about 80% by weight of styrene and about 20 to about 50% by weight of butadiene.

5. In the above 1 to 4 embodiments, the weight ratio of the styrene-butadiene rubber polymer and the cyclohexyl (meth)acrylate copolymer may be about 1: 0.01 to about 1:1.

6. In the above 1 to 5 embodiments, the thermoplastic resin composition is a cracking height of a 3.2 mm thick specimen measured using a dart weighing 900 g based on the DuPont drop measurement method. may be about 20 to about 70 cm, and according to ISO 306, the Vicat softening temperature of a 6.4 mm thick flexural specimen measured under a 5 kg load and 50° C./hr condition may be about 95 to about 115° C., and the thickness After applying 300 ml of an aqueous detergent solution (detergent:water (weight ratio)=4:1) to a 3.2 mm ASTM D638 tensile specimen, cracks, stains, and erosion occurred even when left at 90°C and 95% relative humidity for 16 hours may not be doing it.

7. In embodiments 1 to 6, the thermoplastic resin composition may have a haze of about 0.5 to about 20% of a 2.5 mm thick specimen measured according to ASTM D1003, and a light transmittance of about 78 to about 99 It can be %.

8. 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 7.

9. In the eighth embodiment, the molded article may be a transparent material for a drum washing machine.

The present invention has the effect of providing a thermoplastic resin composition excellent in impact resistance, heat resistance, chemical resistance, transparency, 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) an aromatic vinyl-vinyl cyanide-based copolymer resin; (B) a styrene-butadiene rubbery polymer; and (C) a cyclohexyl (meth)acrylate copolymer.

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

(A) Aromatic vinyl-vinyl cyanide copolymer resin

The aromatic vinyl-vinyl cyanide-based copolymer resin of the present invention can improve mechanical properties such as chemical resistance and rigidity of the thermoplastic resin composition, and is a polymer of a monomer mixture including an aromatic vinyl-based monomer and a vinyl cyanide-based monomer. .

In an embodiment, the aromatic vinyl-vinyl cyanide-based copolymer resin is a copolymer comprising a repeating unit derived from an aromatic vinyl-based monomer and a repeating unit derived from a vinyl cyanide-based monomer, and the monomer mixture is subjected to a known polymerization method. It can be obtained by reacting accordingly. In addition, if necessary, by further including a monomer that imparts processability and heat resistance to the monomer mixture, an aromatic vinyl-vinyl cyanide copolymer resin further comprising a repeating unit derived from a monomer imparting processability and heat resistance can be obtained. have.

In an embodiment, the aromatic vinyl-based monomer is polymerized with a vinyl cyanide-based monomer and the like to form a repeating unit derived from the aromatic vinyl-based monomer, and includes styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, pt-butylstyrene, ethylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene, vinylnaphthalene, and the like may be exemplified, but the present invention is not limited thereto. These can be used individually or in mixture of 2 or more types. The content of the aromatic vinyl-based monomer (repeating unit derived from the aromatic vinyl-based monomer) is about 50 to about 80% by weight, for example, about 55% by weight of 100% by weight of the monomer mixture (aromatic vinyl-cyanide-based copolymer resin) to about 75% by weight. In the above range, the thermoplastic resin composition may have excellent moldability, appearance characteristics, and the like.

In an embodiment, the vinyl cyanide monomer may be polymerized with an aromatic vinyl monomer and the like to form a repeating unit derived from a vinyl cyanide monomer, and may include acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile, and the like. nitrile, α-chloroacrylonitrile, fumaronitrile, and the like can be exemplified. These can be used individually or in mixture of 2 or more types. For example, acrylonitrile, methacrylonitrile, etc. can be used. The content of the vinyl cyanide monomer (repeating unit derived from the vinyl cyanide monomer) is about 20 to about 50 wt %, for example about 25, in 100 wt % of the monomer mixture (aromatic vinyl-vinyl cyanide copolymer resin). to about 45% by weight. In the above range, the thermoplastic resin composition may have excellent chemical resistance, heat resistance, rigidity, and the like.

In embodiments, the monomer for imparting the processability and heat resistance may include (meth)acrylic acid, maleic anhydride, N-substituted maleimide, and the like, but is not limited thereto. When the monomer for imparting the processability and heat resistance is used, the content thereof may be about 30 parts by weight or less, for example, about 1 to about 25 parts by weight based on about 100 parts by weight of the monomer mixture. Within the above range, processability and heat resistance may be imparted to the thermoplastic resin composition without deterioration of other physical properties.

In an embodiment, the aromatic vinyl-vinyl cyanide copolymer resin is a copolymer of styrene and acrylonitrile, a copolymer of styrene, α-methylstyrene and acrylonitrile, and a copolymer of α-methylstyrene and acrylonitrile. It may include one or more types.

In an embodiment, the aromatic vinyl-vinyl cyanide copolymer resin has a weight average molecular weight measured by gel permeation chromatography (GPC) of about 100,000 to about 400,000 g/mol, for example, about 150,000 to about 350,000 g/mol. Within the above range, the thermoplastic resin composition may have excellent heat resistance, rigidity, impact resistance, and the like. In addition, the aromatic vinyl-vinyl cyanide-based copolymer resin may be a mixture of two or more aromatic vinyl-cyanide-based copolymer resins having different weight average molecular weights (Mw).

(B) styrene-butadiene rubbery polymer

The styrene-butadiene rubber polymer of the present invention is applied together with a cyclohexyl (meth)acrylate copolymer to an aromatic vinyl-vinyl cyanide-based copolymer resin, thereby improving the impact resistance of the thermoplastic resin composition without lowering the transparency. As one, it can be obtained by polymerizing styrene and butadiene. The polymerization may be performed by a known polymerization method such as emulsion polymerization or suspension polymerization.

In an embodiment, the styrene-butadiene rubbery polymer comprises from about 50% to about 80% by weight of styrene, such as from about 55% to about 75% by weight, and from about 20% to about 50% by weight of butadiene, such as from about 25% to about 45% by weight. % of the polymer. In the above range, the thermoplastic resin composition may have excellent impact resistance, transparency, and the like.

In an embodiment, the styrene-butadiene rubbery polymer has an MVR (melt volume rate, 200° C./5 kg) of about 5 to about 20 cm ³ /10 min, for example, about 10 to about 15 cm ^{3 measured by the ISO 1133 method.} /10 min. In the above range, the thermoplastic resin composition may have excellent impact resistance.

In an embodiment, the styrene-butadiene rubbery polymer may have a transmittance of about 89 to about 95%, for example, about 90 to about 94, as measured by the ASTM D1003 method, and a haze of about 0.5 to about 4%, for example, from about 1 to about 3%. In the above range, transparency of the thermoplastic resin composition may be excellent.

In an embodiment, the styrene-butadiene rubbery polymer may be included in an amount of about 1 to about 13 parts by weight, for example, about 3 to about 10 parts by weight, based on 100 parts by weight of the aromatic vinyl-vinyl cyanide-based copolymer resin. When the content of the styrene-butadiene rubber polymer is less than about 1 part by weight based on about 100 parts by weight of the aromatic vinyl-vinyl cyanide-based copolymer resin, there is a risk that the impact resistance of the thermoplastic resin composition may be lowered, and about 13 parts by weight When it exceeds the part, there is a fear that the heat resistance, chemical resistance, transparency, rigidity, etc. of the thermoplastic resin composition may decrease.

(C) cyclohexyl (meth)acrylate copolymer

The cyclohexyl (meth)acrylate copolymer of the present invention is applied to an aromatic vinyl-vinyl cyanide-based copolymer resin together with a styrene-butadiene rubber polymer to improve the chemical resistance, impact resistance, heat resistance, etc. of the thermoplastic resin composition. As such, a commercially available cyclohexyl (meth)acrylate copolymer may be used.

In an embodiment, the cyclohexyl (meth) acrylate copolymer is used in an amount of about 0.05 to about 5 parts by weight, for example, about 0.1 to about 3 parts by weight, based on 100 parts by weight of the aromatic vinyl-vinyl cyanide-based copolymer resin. may be included. When the content of the cyclohexyl (meth) acrylate copolymer is less than about 0.05 parts by weight based on 100 parts by weight of the aromatic vinyl-vinyl cyanide copolymer resin, there is a risk that the chemical resistance of the thermoplastic resin composition may be lowered, and , When it exceeds about 5 parts by weight, there is a fear that the impact resistance, transparency, etc. of the thermoplastic resin composition may decrease.

In an embodiment, the weight ratio (B:C) of the styrene-butadiene rubbery polymer (B) and the cyclohexyl (meth)acrylate copolymer (C) is about 1: 0.01 to about 1:1, for example about 1 : 0.02 to about 1: 0.6. In the above range, the thermoplastic resin composition may have excellent impact resistance, chemical resistance, heat resistance, transparency, and balance of these properties.

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, an antioxidant, an anti-drip agent, a lubricant, a mold release agent, a nucleating agent, an antistatic agent, a stabilizer, a pigment, a dye, and a mixture thereof. When the additive is used, its content may be from about 0.001 to about 40 parts by weight, for example, from about 0.1 to about 10 parts by weight, based on about 100 parts by weight of the aromatic vinyl-vinyl cyanide-based copolymer resin.

The thermoplastic resin composition according to an embodiment of the present invention is in the form of pellets that are melt-extruded at about 200 to about 280°C, for example, about 210 to about 260°C, by mixing the above components and using a conventional twin-screw extruder. can

In an embodiment, the thermoplastic resin composition has a cracking drop height of about 20 to about 70 of a 3.2 mm thick specimen measured using a dart weighing 900 g based on the DuPont drop measurement method. cm, for example, it may be about 30 to about 65 cm, and according to ISO 306, the Vicat softening temperature of the 6.4 mm thick flexural specimen measured under the conditions of 5 kg load and 50° C./hr is about 95 to about 115° C., For example, it may be about 98 to about 110 ℃, after applying 300 ml of an aqueous detergent solution (detergent: water (weight ratio) = 4:1) to an ASTM D638 tensile specimen having a thickness of 3.2 mm, 90 ℃ and 95% relative humidity It may be that cracks, stains and erosion do not occur even if left for 16 hours.

In an embodiment, the thermoplastic resin composition may have a haze of about 0.5 to about 20%, for example, about 2 to about 15%, of a 2.5 mm thick specimen measured according to ASTM D1003, and a light transmittance of about 78 to about 99%, such as about 80 to about 95%.

The molded article according to the present invention is formed from the thermoplastic resin composition. The thermoplastic resin composition may be prepared in the form of pellets, and the manufactured pellets may be manufactured into various molded articles (products) through various molding methods such as injection molding, extrusion molding, vacuum molding, and casting molding. Such a molding method is well known by those of ordinary skill in the art to which the present invention pertains. The molded article has excellent impact resistance, heat resistance, chemical resistance, transparency, and the like, and is useful as exterior materials (replacement materials for tempered glass products) such as electrical/electronic products. In particular, the molded article is very useful as a transparent material for a drum washing machine.

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) Aromatic vinyl-vinyl cyanide copolymer resin

A SAN resin (weight average molecular weight: 140,000 g/mol) in which 66 wt% of styrene and 34 wt% of acrylonitrile were polymerized was used.

(B) styrene-butadiene rubbery polymer

A styrene-butadiene rubbery polymer (manufacturer: INEOS Styrolution, product name: KR38) in which 65% by weight of styrene and 35% by weight of butadiene were polymerized was used.

(C) (meth)acrylate compound

(C1) Cyclohexyl (meth)acrylate copolymer (manufacturer: EK chemicals, product name: Polaris-FL®M970) was used.

(C2) Polymethyl methacrylate (manufacturer: LG MMA, product name: IH830) was used.

Examples 1 to 4 and Comparative Examples 1 to 5

After adding each of the components in the amounts as shown in Tables 1 and 2 below, the pellets were prepared by extrusion at 230°C. For extrusion, a twin-screw extruder with L/D=36 and a diameter of 45 mm was used, and the produced pellets were dried at 80° C. for 4 hours or more, and then injected in a 6 Oz injection machine (molding temperature 230° C., mold temperature: 60° C.). was 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) Surface impact strength (unit: cm): Based on the DuPont drop measurement method, a drop height of 3.2 mm thick specimen was measured using a dart weighing 900 g.

(2) Vicat Softening Temperature (VST) (unit: ℃): In accordance with ISO 306, the Vicat softening temperature of a 6.4 mm thick flexural specimen measured under a 5 kg load and 50° C./hr condition was measured.

(3) Chemical resistance evaluation: 300 ml of aqueous detergent solution (detergent (manufacturer: LG Household & Health Care, product name: Tech UP):water (weight ratio) = 4:1) was applied to a tensile specimen of ASTM D638 with a thickness of 3.2 mm, and then applied at 90 ° C. And it was left for 16 hours in a constant temperature/humidity chamber (ESPEC, SH-661) under the condition of 95% relative humidity, and then it was checked whether cracks, stains, or erosion occurred in the specimen.

(4) Haze and light transmittance (unit: %): Haze and light transmittance (total light transmittance) of a 2.5 mm thick specimen were measured using a Haze meter NDH 2000 equipment manufactured by Nippon Denshoku in accordance with ASTM D1003.

	Example
	One	2	3	4
(A) (parts by weight)	100	100	100	100
(B) (parts by weight)	5	10	5	5
(C1) (parts by weight)	One	One	0.1	3
(C2) (parts by weight)	-	-	-	-
Surface impact strength (cm)	50	60	50	35
VST (℃)	101	98	101	100
Evaluation of chemical resistance (whether cracks, stains, or erosion occurred)	non-occurring	non-occurring	non-occurring	non-occurring
Haze (%)	10	15	10	15
light transmittance (%)	85	80	85	80

	comparative example
	One	2	3	4	5
(A) (parts by weight)	100	100	100	100	100
(B) (parts by weight)	0.1	15	5	5	5
(C1) (parts by weight)	One	One	0.01	6	-
(C2) (parts by weight)	-	-	-	-	5
Surface impact strength (cm)	15	80	50	15	10
VST (℃)	105	93	101	99	100
Assessment of chemical resistance (whether cracks, stains or erosion has occurred)	non-occurring	Occur	Occur	non-occurring	Occur
Haze (%)	5	25	10	25	5
light transmittance (%)	90	70	85	75	90

From the above results, it can be seen that the thermoplastic resin compositions (Examples 1 to 5) of the present invention have excellent impact resistance, heat resistance, chemical resistance, transparency, and the like.

On the other hand, in Comparative Example 1 in which a small amount of styrene-butadiene rubber polymer was applied, it can be seen that the impact resistance of the thermoplastic resin composition was lowered, and in Comparative Example 2 in which an excessive amount of styrene-butadiene rubber polymer was applied, the heat resistance of the thermoplastic resin composition, It can be seen that chemical resistance, transparency, and the like are lowered. In addition, in the case of Comparative Example 3 in which a small amount of the cyclohexyl (meth) acrylate copolymer was applied, it was found that the chemical resistance of the thermoplastic resin composition was lowered, and the cyclohexyl (meth) acrylate copolymer was applied in an excessive amount of Comparative Example 4 In this case, it can be seen that the transparency, impact resistance, etc. of the thermoplastic resin composition are lowered, and in Comparative Example 5 in which polymethyl methacrylate (C2) is applied instead of the cyclohexyl (meth) acrylate copolymer of the present invention, the thermoplastic It can be seen that the impact resistance, chemical resistance, etc. of the resin composition are reduced.

Simple modifications or changes of the present invention can be easily carried out by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (9)

1. About 100 parts by weight of an aromatic vinyl-vinyl cyanide-based copolymer resin;

   about 1 to about 13 parts by weight of a styrene-butadiene rubbery polymer; and

   A thermoplastic resin composition comprising; about 0.05 to about 5 parts by weight of a cyclohexyl (meth)acrylate copolymer.
2. According to claim 1, wherein the aromatic vinyl-vinyl cyanide copolymer resin is a polymer of a monomer mixture comprising about 50 to about 80 wt% of an aromatic vinylic monomer and about 20 to about 50 wt% of a vinyl cyanide monomer. A thermoplastic resin composition comprising
3. The thermoplastic resin composition according to claim 1 or 2, wherein the aromatic vinyl-vinyl cyanide copolymer resin has a weight average molecular weight of about 100,000 to about 400,000 g/mol as measured by gel permeation chromatography (GPC). .
4. 4. The thermoplastic resin composition of any one of claims 1 to 3, wherein the styrene-butadiene rubbery polymer is a polymer of about 50 to about 80 weight percent styrene and about 20 to about 50 weight percent butadiene.
5. 5. The thermoplastic resin according to any one of claims 1 to 4, wherein the weight ratio of the styrene-butadiene rubbery polymer and the cyclohexyl (meth)acrylate copolymer is from about 1: 0.01 to about 1:1. composition.
6. The method according to any one of claims 1 to 5, wherein the thermoplastic resin composition is a 3.2 mm mm thick specimen measured using a dart weighing 900 g based on the DuPont drop measurement method. Crack) occurrence drop height is about 20 to about 70 cm, and according to ISO 306, the Vicat softening temperature of a 6.4 mm thick flexural specimen measured under a 5 kg load and 50 ° C / hr condition is about 95 to about 115 ° C, After 300 ml of an aqueous detergent solution (detergent:water (weight ratio)=4:1) was applied to a tensile specimen of ASTM D638 with a thickness of 3.2 mm, cracks, stains and erosion were not observed even when left at 90°C and 95% relative humidity for 16 hours. A thermoplastic resin composition characterized in that it does not occur.
7. The method according to any one of claims 1 to 6, wherein the thermoplastic resin composition has a haze of about 0.5 to about 20% and a light transmittance of about 78 to about 20% of a 2.5 mm thick specimen measured according to ASTM D1003. A thermoplastic resin composition, characterized in that about 99%.
8. A molded article, characterized in that it is formed from the thermoplastic resin composition according to any one of claims 1 to 7.
9. The molded article according to claim 8, wherein the molded article is a transparent material for a drum washing machine.