KR20050064806A - Weather resistant thermoplastic resin composition having improved coloring property - Google Patents

Abstract

The weatherable thermoplastic resin composition having improved colorability according to the present invention comprises (A) 100 parts by weight of a monomer mixture composed of 20 to 30% by weight of a vinyl cyanide compound and 80 to 70% by weight of an aromatic vinyl compound in 20 to 60 parts by weight of an acrylic synthetic rubber. Acrylic graft polymers polymerized by a polymerization method; (B) Diene-based graft polymerized by 20 to 60 parts by weight of diene-based synthetic rubber, 100 parts by weight of a monomer mixture composed of 20 to 30% by weight of vinyl cyanide compound and 80 to 70% by weight of aromatic vinyl compound polymer; (C) a vinyl cyanide compound-aromatic vinyl compound copolymer having a weight average molecular weight of 100,000 to 400,000 copolymerized with 20 to 40 parts by weight of a vinyl cyanide compound and 80 to 60 parts by weight of an aromatic vinyl compound; And (D) a methacrylic acid alkyl ester compound copolymerized with 40 to 80 parts by weight of a methacrylic acid alkyl ester compound and 10 to 30 parts by weight of an aromatic vinyl compound, followed by copolymerization with 0 to 50 parts by weight of a vinyl cyanide compound. A vinyl cyanide compound-aromatic vinyl compound copolymer, wherein the weight ratio of (A) + (B) :( C) + (D) is in the range of 60:40 to 20:80, and of (A) :( B) The weight ratio is in the range of 90:10 to 50:50, and the weight ratio of (C) :( D) is in the range of 70:30 to 0: 100.

Description

Weather Resistant Thermoplastic Resin Composition Having Improved Coloring Property}

Field of invention

The present invention relates to weather resistant thermoplastic resin compositions. More specifically, in the present invention, an acrylic graft polymer, a diene graft copolymer, a vinyl cyanide compound-aromatic vinyl compound copolymer and a methacrylic acid alkylester compound-vinyl cyanide compound-aromatic vinyl compound copolymer The present invention relates to a weather resistant thermoplastic resin composition with improved colorability.

Background of the Invention

Generally, acrylonitrile-butadiene-styrene resin (hereinafter referred to as 'ABS resin') is widely used in electric / electronic products, automobile parts, and general merchandise because of its excellent impact resistance, mechanical strength, surface properties, and workability. Resin. However, ABS resins contain chemically unstable double bonds in the rubber components of the resin due to the resin properties, so that the rubber components can be easily aged by ultraviolet rays, so the weather resistance and light resistance are not good. Over time, discoloration and physical property deterioration are relatively large, which makes it unsuitable for outdoor use exposed to sunlight. Therefore, in order to compensate for this, the ABS resin molded article is subjected to post-processing such as painting or plating, or a method of adding a large amount of UV stabilizer during extrusion of ABS resin, but the former has a disadvantage in that the process is complicated and the defective rate is high. The disadvantage is that manufacturing costs are not increased and satisfactory long term weather resistance is not obtained.

In order to overcome the limitations of the use of ABS resins, various resins are known to have excellent weather resistance instead of ABS resins. Among them, acrylate-styrene-acrylonitrile resin (hereinafter referred to as 'ASA resin') is the most used. It is widely used.

ASA resins are generally vinyl cyanide compounds-aromatic vinyl compounds obtained by copolymerizing an acryl-based graft polymer, a vinyl cyanide compound, and an aromatic vinyl compound by graft polymerization of an acryl-based synthetic rubber with a vinyl cyanide compound and an aromatic vinyl compound. The copolymer is prepared by mixing and extruding. At this time, by controlling the physical properties and content of the acrylic synthetic rubber and acrylic graft polymer, and the matrix polymer, the vinyl cyanide compound-aromatic vinyl compound copolymer, and selectively adding a reinforcing material of a specific role, the desired physical resin can be obtained. have. Thus prepared ASA resin is excellent in weather resistance, light resistance, chemical resistance, heat resistance, etc., so it is suitable for use in outdoor exterior parts with high exposure to sunlight, such as outdoor electrical / electronic products, automotive exterior parts, building materials.

However, the ASA resin has a disadvantage in that the colorability is not as good as that of the ABS resin. For this reason, in order to express colored colors such as green, yellow, and red and high black color in ASA resins, a large amount of salt / pigment needs to be added compared to ABS resins. There may be problems such as poor physical properties and weather resistance.

The reason why ASA resin is poor in colorability compared to ABS resin is that the opacity is large because the refractive index difference between the acrylic synthetic rubber, the graft polymerization component, the matrix polymer component, the vinyl cyanide compound, and the aromatic vinyl compound is large. The greater the level of opacity, the poorer the colorability is, because only the exposed color is seen on the surface, not the color inside the product during coloring.

As a method for producing ASA resin, a method of copolymerizing acrylonitrile and styrene using US Pat. Nos. 4,753,988, 4,801,646, Japanese Patent Laid-Open No. 60-3350, and Japanese Patent Application No. 59-15331 using an acrylic rubber is disclosed. .

In addition, Japanese Patent Laid-Open Nos. 57-212215, 58-187411 and 57-167308 disclose a method of copolymerizing acrylonitrile and styrene on a rubber obtained by mixing polybutadiene rubber and acrylic rubber. However, these patents do not disclose methods for improving the colorability of ASA resins.

Therefore, the present inventors used a mixture of an acrylic graft polymer and a matrix polymer to improve colorability of the ASA resin, and methacrylic acid obtained by copolymerizing a part of the matrix polymer with a methacrylic acid alkylester compound, a vinyl cyanide compound, and an aromatic vinyl compound. By replacing with the alkyl ester compound-vinyl cyanide compound-aromatic vinyl compound copolymer, the colorability is improved by reducing the difference in refractive index between the graft polymer and the matrix to improve the transparency and diene graft to obtain satisfactory impact strength. By adding a polymer, the present invention was completed.

An object of the present invention is to provide a weather resistant thermoplastic resin composition with improved colorability.

Another object of the present invention is to provide a weather resistant thermoplastic resin composition which does not significantly decrease in physical properties such as impact strength even when the coloring property is improved.

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

The weatherable thermoplastic resin composition having improved colorability according to the present invention comprises (A) 100 parts by weight of a monomer mixture composed of 20 to 30% by weight of a vinyl cyanide compound and 80 to 70% by weight of an aromatic vinyl compound in 20 to 60 parts by weight of an acrylic synthetic rubber. Acrylic graft polymers polymerized by a polymerization method; (B) Diene-based graft polymerized by 20 to 60 parts by weight of diene-based synthetic rubber, 100 parts by weight of a monomer mixture composed of 20 to 30% by weight of vinyl cyanide compound and 80 to 70% by weight of aromatic vinyl compound polymer; (C) a vinyl cyanide compound-aromatic vinyl compound copolymer having a weight average molecular weight of 100,000 to 400,000 copolymerized with 20 to 40 parts by weight of a vinyl cyanide compound and 80 to 60 parts by weight of an aromatic vinyl compound; And (D) a methacrylic acid alkyl ester compound copolymerized with 40 to 80 parts by weight of a methacrylic acid alkyl ester compound and 10 to 30 parts by weight of an aromatic vinyl compound, followed by copolymerization with 0 to 50 parts by weight of a vinyl cyanide compound. A vinyl cyanide compound-aromatic vinyl compound copolymer, wherein the weight ratio of (A) + (B) :( C) + (D) is in the range of 60:40 to 20:80, and of (A) :( B) The weight ratio is in the range of 90:10 to 50:50, and the weight ratio of (C) :( D) is in the range of 70:30 to 0: 100. Hereinafter, the content of the present invention will be described in detail.

(A) Acrylic Graft Polymer

The acrylic graft polymer (A) of the present invention is prepared by a conventional emulsion graft polymerization method by mixing 100 parts by weight of a monomer mixture of a vinyl cyanide compound and an aromatic vinyl compound to 20 to 60 parts by weight (based on solids) of an acrylic synthetic rubber. .

As the monomer mixture of the vinyl cyanide compound and the aromatic vinyl compound, 20 to 30% by weight of vinyl cyanide compound and 80 to 70% by weight of aromatic vinyl compound are used, and the vinyl cyanide compound-aromatic vinyl compound grafted on the acrylic synthetic rubber is used. It is preferable that coaling is 40 to 70 weight% with respect to the whole acrylic graft polymer (A).

The acrylic synthetic rubber for producing the acrylic graft polymer (A) is preferably synthesized from alkyl acrylates having 2 to 8 carbon atoms. The average particle diameter of the acrylic synthetic rubber particles may be in the range of 0.05 to 0.5 µm, and preferably in the range of 0.1 to 0.3 µm.

Vinyl cyanide compounds for preparing the acrylic graft polymer (A) of the present invention include acrylonitrile, methacrylonitrile, and the like, and these may be used alone or in combination.

In addition, aromatic vinyl compounds for preparing the acrylic graft polymer (A) include styrene, alpha-methylstyrene, pt-butylstyrene, 2,4-dimethylstyrene, vinyltoluene, etc., which may be used alone or in combination. Can be.

(B) diene graft polymer

The diene graft polymer (B) of the present invention is mixed with 20 to 60 parts by weight (based on solids) of diene-based synthetic rubber by mixing 100 parts by weight of a monomer mixture of a vinyl cyanide compound and an aromatic vinyl compound by a conventional emulsion graft polymerization method. Manufacture.

The monomer mixture of the vinyl cyanide compound and the aromatic vinyl compound is composed of 20 to 30% by weight of vinyl cyanide compound and 80 to 70% by weight of aromatic vinyl compound, and vinyl cyanide compound-aromatic vinyl grafted on diene-based synthetic rubber. The compound copolymer is preferably 40 to 70% by weight based on the total diene graft polymer (B).

The diene synthetic rubber for preparing the diene graft polymer (B) may include polybutadiene, polyisoprene, polychloroprene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, and the like, among which polybutadiene and butadiene -Styrene copolymer and butadiene-acrylonitrile copolymer are preferred. The average particle diameter of the diene synthetic rubber particles is preferably in the range of 0.1 to 0.6 mu m, more preferably in the range of 0.2 to 0.5 mu m.

Vinyl cyanide compounds for preparing the diene graft polymer (B) of the present invention include acrylonitrile, methacrylonitrile, and the like, and these may be used alone or in combination.

Aromatic vinyl compounds for preparing the diene graft polymer (B) include styrene, alpha-methylstyrene, pt-butylstyrene, 2,4-dimethylstyrene, vinyltoluene, and the like, which may be used alone or in combination. .

(C) Vinyl Cyanide Compound-Aromatic Vinyl Compound Copolymer

The vinyl cyanide compound-aromatic vinyl compound copolymer (C) of the present invention is prepared by a conventional polymerization method using 20 to 40 parts by weight of a vinyl cyanide compound and 80 to 60 parts by weight of an aromatic vinyl compound, and has a weight average molecular weight of 100,000 to 400,000. It is preferable that it is a range.

When the weight average molecular weight of the copolymer (C) is lower than 100,000, the fluidity is increased, but mechanical properties such as tensile strength and impact strength are not sufficient, and when the weight average molecular weight is higher than 400,000, the fluidity is low and it is difficult to process the molded article.

As a vinyl cyanide compound which comprises the vinyl cyanide compound-aromatic vinyl compound copolymer (C) of this invention, an acrylonitrile, methacrylonitrile, etc. can be used individually or in mixture. As the aromatic vinyl compound, a single or a mixture of styrene, alpha-methylstyrene, p-t-butylstyrene, 2,4-dimethylstyrene, vinyltoluene, and the like may be used. In addition, these may be copolymerized with N-phenylmaleimide, N-cyclohexyl maleide, maleic anhydride, and the like, and as a preparation method, an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, or a bulk polymerization method may be applied.

(D) Methacrylic acid alkyl ester compound-vinyl cyanide compound-aromatic vinyl compound copolymer

The methacrylic acid alkyl ester compound-vinyl cyanide compound-aromatic vinyl compound copolymer (D) of the present invention copolymerizes a mixture of 40 to 80 parts by weight of the methacrylic acid alkyl ester compound with 10 to 30 parts by weight of an aromatic vinyl compound, and then 0-50 weight part of vinyl cyanide compounds are prepared by copolymerization.

The methacrylic acid alkyl ester compound constituting the copolymer (D) is a methacrylic acid alkyl ester having 1 to 10 carbon atoms, that is, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and the like. Rate is preferred. In addition, the vinyl cyanide compound constituting the copolymer (D) may be used alone or a mixture of acrylonitrile, methacrylonitrile, and the like. As the aromatic vinyl compound, styrene, alpha-methylstyrene, pt-butylstyrene, Single or a mixture of 2,4-dimethylstyrene, vinyltoluene and the like can be used.

As for the thermoplastic resin composition of this invention, the weight ratio of (A) + (B) :( C) + (D) with respect to 100 weight part of total resin compositions has the preferable range of 60: 40-20: 80. When the weight of (A) + (B) exceeds 60 parts by weight with respect to the entire resin composition, the fluidity is significantly lowered, and when less than 20 parts by weight, the impact strength is lowered and is not practical. In addition, the weight ratio of (A) :( B) is preferably in the range of 90:10 to 50:50. If the weight ratio of (A) is greater than 90, the impact strength is lowered and not practical, and if the weight ratio of (A) is less than 50, the weather resistance is insufficient and the value as weathering resin is inferior. In addition, the weight ratio of (C) :( D) is preferably in the range of 70:30 to 0: 100, but it is not preferable when the weight ratio of (D) is less than 30 because the colorability is insufficient.

The thermoplastic resin composition of the present invention may be prepared by further adding a specific antioxidant, lubricant, impact modifier, light stabilizer, filler, inorganic additives, pigments and / or dyes, etc., selectively according to each use.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

(A) acrylic graft polymer, (B) diene graft polymer, (C) vinyl cyanide compound-aromatic vinyl compound copolymer and (D) methacrylic acid alkyl ester compound used in the following Examples and Comparative Examples The specifications of the vinyl cyanide compound-aromatic vinyl compound copolymer are as follows.

(A) Acrylic Graft Polymer

100 parts by weight of a monomer mixture composed of 25% by weight of acrylonitrile and 75% by weight of styrene acrylate rubber was used as a core-shell graft ASA resin having a rubber particle diameter of about 0.2 μm. .

(B) diene graft polymer

A core-shell graft ABS resin having a rubber particle size of about 0.3 μm of a graft emulsion-polymerized rubber was used in 58 parts by weight of butadiene rubber and 100 parts by weight of a monomer mixture composed of 225% by weight of acrylonitrile and 75% by weight of styrene.

(C) Vinyl Cyanide Compound-Aromatic Vinyl Compound Copolymer

A styrene-acrylonitrile copolymer resin (hereinafter referred to as 'SAN resin') having an acrylonitrile content of 28% by weight, a styrene content of 72% by weight, and a weight average molecular weight of about 120,000 was used.

(D) Methacrylic acid alkyl ester compound-vinyl cyanide compound-aromatic vinyl compound copolymer

Methyl methacrylate-acrylonitrile-styrene copolymer resin having a styrene content of 20% by weight, 75% by weight of methyl methacrylate, 5% by weight of acrylonitrile, and a weight average molecular weight of about 100,000 (hereinafter, 'M-SAN Copolymer resin ').

Examples 1 to 3

0.1 parts by weight of octadil-3- (4-hydroxy-3,5-di-tert-butylphenyl) propionate as antioxidant, 0.3 parts by weight of magnesium stearate as lubricant, and dimethyl as impact modifier Pellets were prepared by adding 0.02 parts by weight of polysiloxane and 0.5 parts by weight of carbon black as a pigment to a content as shown in Table 1, followed by melting and kneading extrusion. The extrusion was performed using a twin screw extruder having a diameter of L / D = 29, 45 mm and the cylinder temperature was set to 220 ℃. The physical properties of the pellets were measured by injection molding, and the physical properties of the pellets were measured by using 10 cm × 10 cm × 0.3 cm sized specimens. The results are shown in Table 2 below.

Comparative Example 1

A specimen was prepared in the same manner as in Example 1 except that 40 parts by weight of the graft ASA resin (A) was used instead of the graft ABS resin (B).

Comparative Example 2

A specimen was prepared in the same manner as in Example 1 except that 60 parts by weight of the SAN resin (C) was used instead of the M-SAN copolymer resin (D).

Comparative Example 3

The sum of the graft ASA resin (A) and the graft ABS resin (B), the SAN resin (C), and the M content of the graft ASA resin (A) and the SAN resin (C) was 12 parts by weight and 43 parts by weight, respectively. Same as Example 1 except that the ratio of (A) + (B) :( C) + (D), which is the weight ratio of the sum of the SAN copolymer resins (D), was outside the range of 60:40 to 20:80 The specimen was prepared.

(A) Graft ASA Resin (B) graft ABS resin (C) SAN resin (D) M-SAN Copolymer Resin Example One 35 5 20 40 2 35 5 - 60 3 30 10 20 40 Comparative Example One 40 - 20 40 2 35 5 60 - 3 12 5 43 40

Physical properties of the specimens prepared by the Examples and Comparative Examples were evaluated by the following methods, and the results are shown in Table 2.

(1) Notched Izod impact strength was measured according to ASTM D256 (1/4 ", 23 ° C).

(2) The flow index was measured according to ISO 1133 (10 kg, 220 ° C.).

(3) Colorability was visually evaluated and classified into upper, middle and lower.

Notched Izod Impact Strength (1/4 ″) (kgfcm / cm) Flow index (g / 10 min) Coloring Example One 15 12 Prize 2 13 12 Prize 3 18 9 Prize Comparative Example One 8 11 medium 2 16 11 Ha 3 7 18 Prize

From the results of Table 2, in the case of Comparative Example 1 in which no graft ABS resin (B) was used at all, the impact strength was very low, and the comparison in which the M-SAN copolymer resin (D) was not used at all was performed. In the case of Example 2, blackness was remarkably dropped, and colorability was not good. In addition, in Comparative Example 3 having a low content of graft ASA resin (A), the colorability was excellent and the flow index was increased, but the impact strength was very low.

The present invention uses a part of the matrix polymer to replace the methacrylic acid alkyl ester compound-vinyl cyanide compound-aromatic vinyl compound copolymer in mixing and using the acrylic graft polymer and the matrix polymer in preparing the acrylic weathering thermoplastic resin composition, By reducing the difference in refractive index between the graft polymer and the matrix to improve the transparency to improve the colorability and adding an appropriate amount of diene graft polymer to it has the effect of providing a weather resistant thermoplastic resin composition having a satisfactory impact strength.

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

Claims (5)

(A) Acrylic graft polymer obtained by polymerizing 100 parts by weight of a monomer mixture composed of 20 to 30% by weight of vinyl cyanide compound and 80 to 70% by weight of aromatic vinyl compound in 20 to 60 parts by weight of acrylic synthetic rubber; (B) Diene-based graft polymerized by 20 to 60 parts by weight of diene-based synthetic rubber, 100 parts by weight of a monomer mixture composed of 20 to 30% by weight of vinyl cyanide compound and 80 to 70% by weight of aromatic vinyl compound polymer; (C) a vinyl cyanide compound-aromatic vinyl compound copolymer having a weight average molecular weight of 100,000 to 400,000 copolymerized with 20 to 40 parts by weight of a vinyl cyanide compound and 80 to 60 parts by weight of an aromatic vinyl compound; And (D) A methacrylic acid alkyl ester compound-cyanide copolymerized with a mixture of 40 to 80 parts by weight of an alkyl methacrylate compound and 10 to 30 parts by weight of an aromatic vinyl compound, followed by copolymerization with 0 to 50 parts by weight of a vinyl cyanide compound. Vinyl compound-aromatic vinyl compound copolymer; As a weather-resistant thermoplastic resin composition comprising a, the weight ratio of (A) + (B): (C) + (D) is in the range of 60: 40 to 20: 80, the weight ratio of (A): (B) is 90: A weather resistant thermoplastic resin composition, wherein the weight ratio of (C) :( D) is in the range of 10:50:50, and in the range of 70: 30-0: 100. The method of claim 1, wherein the acrylic synthetic rubber has an average particle diameter of 0.05 to 0.5 ㎛, synthesized from alkyl acrylate of 2 to 8 carbon atoms; The diene synthetic rubber has an average particle diameter of 0.1 to 0.6 탆, and is selected from the group consisting of polybutadiene, polyisoprene, polychloroprene, butadiene-styrene copolymer, and butadiene-acrylonitrile copolymer; The vinyl cyanide compound is selected from the group consisting of acrylonitrile, methacrylonitrile and mixtures thereof; The aromatic vinyl compound is selected from the group consisting of styrene, alpha-methylstyrene, p-t-butylstyrene, 2,4-dimethylstyrene, vinyltoluene and mixtures thereof; And the methacrylic acid alkyl ester compound is selected from the group consisting of methacrylic acid alkyl ester compounds having 1 to 10 carbon atoms. The content of the vinyl cyanide compound-aromatic vinyl compound copolymer grafted on the acrylic synthetic rubber is 40 to 70% by weight relative to the total acrylic graft polymer and grafted on the diene synthetic rubber. The content of the vinyl cyanide compound-aromatic vinyl compound copolymer is 40 to 70% by weight based on the total diene graft polymer. The weatherable thermoplastic resin composition of claim 1, wherein the resin composition further comprises an antioxidant, a lubricant, an impact modifier, a light stabilizer, a filler, an inorganic additive, a pigment, and / or a dye. Alloy resin composition prepared by blending the resin composition of any one of claims 1 to 4.