KR20070064925A - Thermoplastic transparent acrylonitrile-butadiene-styrene resin compoition with high hardness - Google Patents

Abstract

Provided is a thermoplastic transparent acrylonitrile-butadiene-styrene resin composition, which has excellent transparency, impact strength, processability, surface gloss, hardness and scratch resistance. The thermoplastic transparent acrylonitrile-butadiene-styrene resin composition comprises: (A) 25-75 wt% of a graft copolymer comprising conjugated diene-based rubber latex, alkyl methacrylate or alkyl acrylate compound, aromatic vinyl compound and a vinyl cyanide compound; and (B) 75-25 wt% of a methacrylate-styrene-acrylonitrile(MSAN) copolymer comprising an alkyl methacrylate or alkyl acrylate, aromatic vinyl compound and a vinyl cyanide compound. The resin composition has an average molecular weight of 100,000-300,000 and a rubber content of 4-10 parts by weight.

Description

High hardness thermoplastic transparent ABS resin composition {THERMOPLASTIC TRANSPARENT ACRYLONITRILE-BUTADIENE-STYRENE RESIN COMPOITION WITH HIGH HARDNESS}

The present invention relates to a thermoplastic transparent ABS resin composition, and more particularly, to a high hardness thermoplastic transparent ABS resin composition excellent in transparency and excellent in workability, surface gloss, hardness and scratch resistance.

Generally, acrylonitrile-butadiene-styrene (hereinafter, referred to as 'ABS') resin is used for automobile products and home appliances due to its physical strength and beautiful appearance characteristics such as stiffness and chemical resistance of acrylonitrile, impact resistance of butadiene, and workability of styrene. It is widely used in products, OA products, and the like.

However, because ABS resin is opaque, there is a disadvantage in that its use is limited in parts requiring transparency such as microwave oven transparent window, all-axis transparent window, game console housing, office equipment transparent window, PCS transparent window and the like. Accordingly, the development of transparent materials has been progressing in recent years.

Transparent resins mainly used for products requiring transparency include SAN, PC, GPPS, PMMA, and transparent ABS resins. Among these, the transparent ABS resin has transparency because it minimizes scattering and refraction of light generated at the interface between the dispersed phase and the continuous phase by matching the refractive index of the continuous phase matrix resin with the refractive index of the rubber in the dispersed phase, and has transparency. Due to the high impact strength and excellent workability, recent studies on transparent ABS resins as transparent materials have been actively conducted.

Until now, U.S. Patent No. 3,787,522 and Japanese Patent Laid-Open No. 63-42940 disclose a method of imparting impact resistance to a transparent PMMA resin as a technique for producing a transparent resin having excellent transparency and physical properties. It was excellent but the impact resistance was extremely weak, there was a problem in the application limitations. In addition, European Patent No. 0,702,325 discloses a method of imparting transparency to HIPS resin, which has a problem in that chemical resistance and scratch resistance are lowered. On the other hand, many studies on the transparent ABS resin having a relatively high chemical resistance and scratch resistance has been progressed, but there is a problem that most of the pencil hardness stays at the level of 2B or 3B.

Therefore, it is possible to design a more beautiful appearance, and in order to prevent surface damage for a long time, it is necessary to manufacture a high hardness transparent ABS resin having a scratch resistance of B or more or about HB.

In order to solve the problems of the prior art as described above, the present invention is excellent in transparency, but excellent in workability, surface gloss, hardness and scratch resistance, it is possible to design a beautiful appearance and to prevent long-term surface damage of high hardness It is an object to provide a thermoplastic transparent ABS resin composition.

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

In order to achieve the above object, the present invention

25 to 75% by weight of a graft copolymer (A) consisting of a conjugated diene rubber latex, a methacrylic acid alkyl ester compound or an acrylic acid alkyl ester compound, an aromatic vinyl compound and a vinyl cyan compound; and

75-25% by weight of methacrylate-styrene-acrylonitrile (MSAN) copolymer (B) consisting of a methacrylic acid alkyl ester compound or an acrylic acid alkyl ester compound, an aromatic vinyl compound and a vinyl cyan compound

It comprises, but the weight average molecular weight is 100,000 to 300,000, and provides a thermoplastic transparent ABS resin composition, characterized in that the rubber content of 4 to 10 parts by weight.

Hereinafter, the present invention will be described in detail.

Graft Copolymer (A)

The graft copolymer (A) of the present invention is 10 to 20 parts by weight of the conjugated diene rubber latex, 40 to 70 parts by weight of the alkyl methacrylate or acrylic acid alkyl ester compound, 10 to 40 parts by weight of the aromatic vinyl compound and vinyl It is prepared by graft copolymerization of 1 to 20 parts by weight of a cyan compound.

As the conjugated diene rubber latex, a general butadiene rubber latex or a styrene-butadiene copolymer rubber latex may be used.

The conjugated diene rubber latex has an average particle diameter of 800 to 3500 mm 3, a gel content of 50 to 95%, and a swelling index of 10 to 20.

The conjugated diene rubber latex is preferably used in 10 to 20 parts by weight. When used in the above content has an excellent impact strength and hardness.

As said methacrylic acid alkylester compound or acrylic acid alkylester compound, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid 2-ethylhexyl ester, (meth) acrylic acid decyl Ester or (meth) acrylic acid lauryl ester, etc. can be used, Especially methyl methacrylate which is (meth) acrylic acid methyl ester is the most preferable.

The methacrylic acid alkyl ester compound or acrylic acid alkyl ester compound is preferably used at 40 to 70 parts by weight. When used in the above content is excellent in hardness and transparency.

As said aromatic vinyl compound, styrene, (alpha) -methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, vinyltoluene, etc. can be used, Especially styrene is preferable.

The aromatic vinyl compound is preferably used in 10 to 40 parts by weight. When used in the above content has an excellent transparency effect.

Acrylonitrile, methacrylonitrile or ethacrylonitrile may be used as the vinyl cyan compound.

The vinyl cyan compound is preferably used in 1 to 10 parts by weight. When used in the content is excellent in impact strength, there is no phenomenon affecting the color of the product is changed to a yellow color has excellent transparency effect.

The refractive index of the monomer mixture used in the preparation of the graft copolymer (A) has an absolute effect on the transparency, which is controlled by the amount of the monomer used and the mixing ratio. That is, in order to have transparency, the refractive index of the conjugated diene-based rubber latex used in the manufacture of the graft copolymer should be similar to the refractive index after polymerization of the entire monomer component grafted thereto, and the refractive index of the conjugated diene-based rubber latex It is preferable that the refractive indices of the entire grafted monomer components coincide.

Therefore, the graft copolymer (A) of the present invention has a refractive index of the conjugated diene rubber latex used in the production of the graft copolymer (A) and the polymerization index of the entire monomer component grafted to the conjugated diene rubber latex. It is preferable that the difference is less than 0.005. The refractive index after polymerization of each component used in the production of the graft copolymer (A) is about 1.518 butadiene, about 1.49 methyl methacrylate, about 1.592 styrene, about 1.52 acrylonitrile, The refractive index can be calculated by the following equation.

[Equation 1]

Refractive Index of Graft Polymer = Wt _M × RI _M + Wt _S × RI _S + Wt _A × RI _A

Wt _M : Weight% of methacrylic acid alkyl ester compound or acrylic acid alkyl ester compound

Wt _S : weight% of aromatic vinyl compound

Wt _A : weight% of vinyl cyan compound

RI _M : refractive index of methacrylic acid alkyl ester compound or acrylic acid alkyl ester compound

RI _S : refractive index of aromatic vinyl compound

RI _A : refractive index of vinyl cyan compound

Molecular weight modifiers may be used together to control the molecular weight in the preparation of the graft copolymer (A). As said molecular weight regulator, mercaptans, such as n-dodecyl mercaptan or t-dodecyl mercaptan, can be used.

The graft copolymer (A) preferably has a weight average molecular weight of 80,000 to 300,000. In the case of the weight average molecular weight, the impact strength of the final product is excellent, and the flowability is excellent, thereby improving workability.

The method for preparing the graft copolymer (A) is not particularly limited, but emulsion polymerization is generally preferred. In the case of the bulk polymerization, the grafting is not performed well, and thus the gloss of the final product is lowered, and a rubber having a large particle diameter is generated, thereby lowering the hardness.

The graft copolymer (A) may be included in the thermoplastic transparent ABS resin composition in an amount of 25 to 75 wt%.

Methacrylate-styrene-acrylonitrile (MSAN) copolymer (B)

The methacrylate-styrene-acrylonitrile (MSAN) copolymer (B) of the present invention is 40 to 80 parts by weight of an alkyl methacrylate compound or an acrylic acid alkyl ester compound, 10 to 50 parts by weight of an aromatic vinyl compound and vinyl cyan It is prepared by copolymerizing 1 to 30 parts by weight of the compound.

The methacrylic acid alkyl ester compound or the acrylic acid alkyl ester compound, the aromatic vinyl compound, and the vinyl cyan compound may be the same as those used for the preparation of the graft copolymer (A).

It is preferable to use the said methacrylic acid alkylester compound or the acrylic acid alkylester compound at 40-80 weight part. When used in the above content is excellent in hardness and transparency.

The aromatic vinyl compound is preferably used in 10 to 50 parts by weight. When used in the above content has an excellent transparency effect.

The vinyl cyan compound is preferably used in 1 to 30 parts by weight. When used in the content is excellent in impact strength, there is an effect that does not occur a phenomenon that affects the color of the product is changed to yellow.

The amount of use and the mixing ratio of the monomers used in the production of the MSAN graft copolymer (B) are very important factors for the preparation of the transparent resin, and thus the refractive index varies. That is, in order to have transparency, the refractive indices of the graft copolymer (A) and the MSAN copolymer (B) should be similar, and the refractive indices are preferably identical.

Therefore, the MSAN copolymer (B) of the present invention preferably has a difference between the refractive index of the MSAN copolymer (B) and the refractive index of the graft copolymer (A) is less than 0.005. The refractive index of each component used in the production of the MSAN copolymer (B) is about 1.49 methyl methacrylate, about 1.592 styrene, about 1.52 of acrylonitrile, and the refractive index of the MSAN copolymer (B) is Can be calculated as 1.

In the preparation of the MSAN copolymer (B), a molecular weight modifier may be used together to control the molecular weight. As said molecular weight regulator, mercaptans, such as n-dodecyl mercaptan or t-dodecyl mercaptan, can be used.

The MSAN copolymer (B) preferably has a weight average molecular weight of 80,000 to 300,000. In the case of the weight average molecular weight, the impact strength of the final product is excellent, and the flowability is excellent, thereby improving workability.

The manufacturing method of the MSAN copolymer (B) is not particularly limited, but suspension polymerization or bulk polymerization may be used, and particularly, when the production of the MSAN copolymer (B) is carried out by continuous bulk polymerization, the hardness may be further improved. In the case of emulsion polymerization or bulk polymerization, there is a problem of polymerizing in an aqueous phase to use an emulsifier or a dispersant and remaining in the resin even after dehydration to reduce hardness.

The MSAN copolymer (B) may be included in an amount of 75 to 25 wt% in the thermoplastic transparent ABS resin composition.

Thermoplastic Transparent ABS Resin Composition

The transparent ABS resin composition of the present invention is prepared by kneading 25 to 75 wt% of the graft copolymer (A) and 75 to 25 wt% of the MSAN copolymer (B).

The transparent ABS resin composition is preferably a rubber content of 4 to 10 parts by weight. In the case of the rubber content, the impact strength is excellent, and hardness and scratch resistance are improved.

The transparent ABS resin composition preferably has a weight average molecular weight of 100,000 to 300,000. In the case of the weight average molecular weight, the impact strength of the final product is excellent, the fluidity is improved, and the workability is excellent.

The transparent ABS resin composition may further include a silicone oil when kneading. As the silicone oil, polydimethylsiloxane or polymethylphenylsiloxane may be used. Particularly, polymethylphenylsiloxane is particularly preferable because the refractive index is similar to that of the graft copolymer (A) and the MSAN copolymer (B). .

The silicone oil may be included in an amount of 0.01 to 1.0 parts by weight in the transparent ABS resin composition, it is included in the content has the effect of further improving scratch resistance, without lowering the transparency.

The thermoplastic transparent ABS resin composition of the present invention may further include additives such as lubricants, heat stabilizers, antioxidants, light stabilizers, anti-drip agents, pigments and inorganic fillers, depending on the application.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Preparation Example 1 Preparation of Graft Copolymer (A) -1

The graft copolymer is prepared by emulsion polymerization and has a gel content of 70%, 18 parts by weight of rubber latex having an average particle diameter of 0.3 μm, 100 parts by weight of ion-exchanged water, 0.5 parts by weight of sodium oleate emulsifier, 59 parts by weight of methyl methacrylate, and styrene. 25 parts by weight, 3 parts by weight of acrylonitrile, 0.3 parts by weight of t-dodecyl mercaptan, 0.048 parts by weight of sodium pyrophosphate, 0.012 parts by weight of dextrose, 0.001 parts by weight of ferrous sulfide, and 0.04 parts by weight of cumene hydroperoxide The reaction was continuously performed at 75 ° C. for 5 hours. After the reaction, the temperature was raised to 80 ° C., and aged for 1 hour to terminate the reaction. At this time, the polymerization conversion was 99.8% and the solidified content was 0.1%.

The latex prepared above was coagulated with an aqueous calcium chloride solution and washed to obtain a powder. The refractive index of the graft copolymer (A) -1 obtained was 1.516, and the weight average molecular weight was about 150,000.

Preparation Example 2 Preparation of Graft Copolymer (A) -2

Except that 0.7 parts by weight of t-dodecyl mercaptan in Preparation Example 1 was carried out in the same manner as in Preparation Example 1.

The refractive index of the graft copolymer (A) -2 obtained was 1.516, and the weight average molecular weight was about 60,000.

Preparation Example 3 Preparation of Graft Copolymer (A) -3

In Preparation Example 1, except that 40 parts by weight of rubber latex, 42.5 parts by weight of methyl methacrylate, and 17.5 parts by weight of styrene were used in the same manner as in Preparation Example 1.

The refractive index of the obtained graft copolymer (A) -3 was 1.516, and the weight average molecular weight was about 140,000.

Preparation Example 4 Preparation of MSAN Copolymer (B) -1

An average reaction time of 3 hours was obtained when a raw material obtained by mixing 68 parts by weight of methyl methacrylate, 22 parts by weight of styrene, and 10 parts by weight of acrylonitrile as a solvent and 30 parts by weight of toluene as a solvent and 0.15 parts by weight of t-dodecyl mercaptan as a molecular weight regulator. The reaction temperature was continuously maintained at 148 ° C. as much as possible. The polymer solution discharged from the reactor was heated in a preheating bath, the unreacted monomer was volatilized in the volatilization tank, and the temperature of the polymer was maintained at 210 ° C., so that the copolymer resin was processed into pellets using a polymer transfer pump extrusion machine.

The refractive index of the prepared MSAN copolymer (B) -1 was 1.516, and the weight average molecular weight was about 150,000.

Preparation Example 5 Preparation of MSAN Copolymer (B) -2

The preparation was carried out in the same manner as in Preparation Example 4, except that methyl methacrylate was used in 40 parts by weight and styrene was used in 50 parts by weight.

The refractive index of the prepared MSAN copolymer (B) -2 was 1.542, and the weight average molecular weight was about 150,000.

Preparation Example 6 Preparation of MSAN Copolymer (B) -3

The preparation was carried out in the same manner as in Preparation Example 4, except that t-dodecyl mercaptan was used in 0.5 parts by weight.

The refractive index of the prepared MSAN copolymer (B) -3 was 1.516, and the weight average molecular weight was about 60,000.

Physical properties of the graft copolymer (A) and the MSAN copolymer (B) prepared in Preparation Examples 1 to 6 were measured by the following method.

* Refractive index: The sample was thinned to a thickness of about 0.2 mm, and measured with an Abbe refractometer at 25 ° C.

* Weight average molecular weight: The weight average molecular weight was measured using GPC. After verification using the PMMA standard, the weight average molecular weight of the sample was measured.

Examples 1 to 3 and Comparative Examples 1 to 4

The graft copolymer (A) prepared in Preparation Examples 1 to 3 and the MSAN copolymer (B) prepared in Preparation Examples 4 to 6 were mixed in the compositions shown in Table 1 below, and 0.1 parts by weight of a lubricant and an antioxidant 0.2 parts by weight was prepared in pellet form using a twin screw extruder at a cylinder temperature of 220 ℃. The prepared pellets were injected into specimens.

division Graft Copolymer (A) MSAN copolymer (B) Weight average molecular weight Silicone oil (parts by weight) Rubber content (parts by weight) A-1 A-2 A-3 B-1 B-2 B-3 Example 1 44.4 55.6 150,000 - 8 Example 2 27.8 72.2 150,000 - 5 Example 3 44.4 55.6 150,000 0.3 8 Comparative Example 1 44.4 55.6 150,000 - 8 Comparative Example 2 44.4 55.6 60,000 - 8 Comparative Example 3 37.5 62.5 147,000 - 15 Comparative Example 4 20 80 148,000 - 8 Silicone Oil: Polymethylfetylsiloxane

Physical properties of the transparent ABS resin composition specimens prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 2 below.

* Transparency (Haze Value): Measured according to ASTM1003.

* Hardness (Rockwell Hardness, R-scale): measured according to ASTM D-785.

* Pencil Hardness: Measured according to ASTM D-3365.

* Notched Izod Impact Strength: Measured according to ASTM D-256 using 1/4 specimen.

division Transparency (Haze) Hardness (R-scale) Pencil hardness Impact Strength (kgcm / cm) Example 1 1.5 120 HB 10 Example 2 1.8 123 H 7 Example 3 1.7 119 H 10 Comparative Example 1 5.6 118 B 9 Comparative Example 2 2.9 115 HB 4 Comparative Example 3 3.1 100 3B 15 Comparative Example 4 2.2 120 HB 3

Through Table 2, the thermoplastic transparent ABS resin composition of Examples 1 to 3 of the present invention prepared using the graft copolymer (A) and the MSAN copolymer (B) having similar refractive indices has a hardness of 119 or more, and a pencil The hardness was more than H, the impact strength was 7 kg · cm / cm or more, it was confirmed that the excellent physical properties while excellent in transparency.

On the other hand, the thermoplastic transparent ABS resin composition of Comparative Example 1 prepared using the graft copolymer (A) and the MSAN copolymer (B) having different refractive indices did not have good transparency and color, and graft air having a low weight average molecular weight. In the thermoplastic transparent ABS resin composition of Comparative Example 2 prepared using the copolymer (A) and the MSAN copolymer (B), the weight average molecular weight of the final product was also less than 100,000, and it was confirmed that the impact strength rapidly decreased. In addition, the thermoplastic transparent ABS resin composition of Comparative Example 3 in which the final rubber content does not fall within the scope of the present invention did not have good hardness and pencil hardness, and the final rubber content falls within the range of the present invention, but the graft copolymer (A It was confirmed that the impact strength of the thermoplastic transparent ABS resin composition of Comparative Example 4 in which the rubber content of) does not fall within the scope of the present invention is sharply lowered.

As described above, according to the present invention, it is excellent in transparency, impact strength, processability, surface gloss, hardness and scratch resistance, it is possible to design a beautiful appearance and high hardness thermoplastic that can prevent surface damage for a long time There is an effect of providing a transparent ABS resin composition. Although described in detail above with reference to the specific embodiments of the present invention, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and such variations and modifications belong to the appended claims. It is also natural.

Claims (12)

25 to 75% by weight of a graft copolymer (A) consisting of a conjugated diene rubber latex, a methacrylic acid alkyl ester compound or an acrylic acid alkyl ester compound, an aromatic vinyl compound and a vinyl cyan compound; and 75-25% by weight of methacrylate-styrene-acrylonitrile (MSAN) copolymer (B) consisting of a methacrylic acid alkyl ester compound or an acrylic acid alkyl ester compound, an aromatic vinyl compound and a vinyl cyan compound Including but not limited to, A weight average molecular weight of 100,000 to 300,000, a rubber content of 4 to 10 parts by weight of the thermoplastic transparent ABS resin composition. The method of claim 1, The graft copolymer (A) is 10 to 20 parts by weight of a conjugated diene rubber latex, 40 to 70 parts by weight of an alkyl methacrylate compound or an acrylic acid alkyl ester compound, 10 to 40 parts by weight of an aromatic vinyl compound and vinyl cyan compound 1 To 20 parts by weight of graft copolymerization, characterized in that the thermoplastic transparent ABS resin composition. The method of claim 1, The conjugated diene rubber latex has an average particle diameter of 800 to 3500 mm 3, a gel content of 50 to 95%, and a swelling index of 10 to 20, characterized in that the thermoplastic transparent ABS resin composition. The method of claim 1, The conjugated diene-based rubber latex has a refractive index difference from the refractive index after polymerization of the entire monomer component grafted onto the conjugated diene-based rubber latex, the thermoplastic transparent ABS resin composition, characterized in that. The method of claim 1, The graft copolymer (A) is a thermoplastic transparent ABS resin composition, characterized in that the weight average molecular weight of 80,000 to 300,000. The method of claim 1, The methacrylate-styrene-acrylonitrile (MSAN) copolymer (B) is a methacrylic acid alkyl ester compound or acrylic acid alkyl ester compound 40 to 80 parts by weight, aromatic vinyl compound 10 to 50 parts by weight and vinyl cyan compound 1 to Thermoplastic transparent ABS resin composition characterized in that it is produced by copolymerizing 30 parts by weight. The method of claim 1, The methacrylate-styrene-acrylonitrile (MSAN) copolymer (B) has a refractive index difference from the refractive index of the graft copolymer (A) is less than 0.005 thermoplastic transparent ABS resin composition. The method of claim 1, The methacrylate-styrene-acrylonitrile (MSAN) copolymer (B) has a weight average molecular weight of 80,000 to 300,000, characterized in that the thermoplastic transparent ABS resin composition. The method of claim 1, The methacrylic acid alkyl ester compound or the acrylic acid alkyl ester compound is (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid 2-ethylhexyl ester, (meth) acrylic acid decyl ester And (meth) acrylic acid lauryl ester. The thermoplastic transparent ABS resin composition, characterized in that at least one selected from the group consisting of. The method of claim 1, The at least one aromatic vinyl compound is selected from the group consisting of styrene, α-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, and vinyltoluene. The method of claim 1, The vinyl cyan compound is at least one member selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile. The method of claim 1, The thermoplastic transparent ABS resin composition is a thermoplastic transparent ABS resin composition, characterized in that it further comprises 0.01 to 1.0 parts by weight of silicone oil.