KR100583525B1 - High Impact Polystyrene Resin with Good Falling Dart Impact and Anti-Abrasion Prepared by Continuous Mass Polymerization Process - Google Patents

Abstract

The high impact polystyrene resin of the present invention comprises 5 to 15 parts by weight of polymer (I) of styrene monomer and polybutadiene rubber 1 having a rubber particle diameter of 0.3 to 0.6 µm; 70 to 85 parts by weight of polymer (II) of styrene monomer and polybutadiene rubber 2 having a rubber particle diameter of 1.5 to 2.0 µm; And 5 to 20 parts by weight of polymer (III) of styrene-based monomer and polybutadiene rubber 3 having a diameter of 3.5 to 4.5 µm of rubber particles, and further polymerize 0.5 to 1.5 parts by weight of silicone oil, The dispersed rubber particles are characterized by having a trimodal form.

High impact polystyrene resin, styrene monomer, polybutadiene rubber, silicone oil, drop impact strength, wear resistance

Description

High Impact Polystyrene Resin with Good Falling Dart Impact and Anti-Abrasion Prepared by Continuous Mass Polymerization Process}             

1 is a process chart showing a bulk polymerization continuous process for producing a high impact polystyrene resin of the present invention.

Field of invention

The present invention relates to a high impact polystyrene resin excellent in drop impact strength and wear resistance. More specifically, the present invention relates to a rubber-modified polystyrene resin having excellent drop impact strength and wear resistance by introducing a rubber particle size dispersed in a polystyrene resin composition into a trimodal form and injecting a high viscosity silicone oil during the polymerization process.

Background of the Invention

Styrene-based resins have been produced commercially a lot of excellent transparency, thermal stability, processability. In particular, a rubber-modified polystyrene resin has been developed by introducing rubber particles into a styrene resin to enhance impact resistance. This is called high impact polystyrene (HIPS). Such high impact polystyrene resins have a low Tg in rubber, especially cross-linked polybutadiene particles, such as styrene, alpha-methylstyrene, and ring-substituted styrene. It is dispersed in, and has good physical properties such as impact resistance, heat resistance, fluidity, and the like, and is widely used as an electric and electronic component. In particular, as consumer preferences for large products have increased in recent years, home appliance companies have increased the output of large products, and at the same time, measures to reduce the thickness of products have been attempted to reduce the weight and manufacturing cost of large products. However, when the thickness of the product is reduced, the drop impact strength is lowered, so there is a problem that a crack occurs in the appearance of the molded product even with a small impact. In addition, in the case of the conventional high-impact polystyrene resin, there is a problem such as wear of the molded product, scratch on the surface, generation of powder on the assembly line due to the lack of wear resistance when used as the sliding material. Therefore, resin manufacturers are developing products with excellent drop impact strength and wear resistance to compensate for these disadvantages.

Conventional techniques for solving the above problems include a technique of adding polydimethylsiloxane to styrene resins, such as Japanese Patent No. 60-217254, but this technique still suffers from a lack of drop impact strength and wear resistance.

Therefore, the inventors of the present invention provide a rubber-modified polystyrene having excellent drop impact strength and abrasion resistance by introducing a trimodal form of rubber particles dispersed on a polystyrene resin composition and injecting high-viscosity silicone oil during the polymerization process in order to solve the above problems. Resin was developed.

An object of the present invention is to provide a high impact polystyrene resin excellent in drop impact strength and wear resistance.

Another object of the present invention is to provide a rubber-modified polystyrene resin having excellent drop impact strength and abrasion resistance by adding a high viscosity silicone oil in the polymerization process in the form of trimodal rubber particles introduced into the high impact polystyrene resin.

Another object of the present invention is to provide a rubber-modified polystyrene resin with improved wear resistance so that even when the high-impact polystyrene resin is used as a sliding material, wear of molded products, scratches on the surface, and powder of the assembly line are not generated. will be.

The above and other objects of the present invention can be achieved by the present invention described below. Hereinafter, the content of the present invention will be described in detail.

The high impact polystyrene resin of the present invention comprises 5 to 15 parts by weight of polymer (I) of styrene monomer and polybutadiene rubber 1 having a rubber particle diameter of 0.3 to 0.6 µm; 70 to 85 parts by weight of polymer (II) of styrene monomer and polybutadiene rubber 2 having a rubber particle diameter of 1.5 to 2.0 µm; And 5 to 20 parts by weight of polymer (III) of styrene-based monomer and polybutadiene rubber 3 having a diameter of 3.5 to 4.5 µm of rubber particles, and further polymerize 0.5 to 1.5 parts by weight of silicone oil, The dispersed rubber particles have a trimodal form.

1 is a process chart showing a bulk polymerization continuous process for producing a high impact polystyrene resin of the present invention.

The styrene monomer and the polybutadiene rubber 1 are mixed in the R-1-1 reactor and polymerized at 110 to 140 ° C. for 1.5 to 2.5 hours at a conversion rate of 20 to 30%. In this case, the styrene monomers used are styrene, α-methyl styrene, α-ethyl styrene, ρ-methyl styrene, and the like, and polybutadiene rubber 1 has a 1,4-cis content of 43 wt% or less and 95 parts by weight of styrene. The viscosity of the rubber solution consisting of the monomer and 5 parts by weight of the polybutadiene rubber 1 is 40 to 60 centipoise level. Polymer (I) polymerized in the R-1-1 reactor has a rubber particle diameter of 0.3 to 0.6 mu m.

In the R-1-2 reactor, a styrene monomer and a polybutadiene rubber 2 are mixed and polymerized at 110 to 140 ° C. for 1.5 to 2.5 hours at a conversion rate of 20 to 30%. In this case, the styrene monomer used is the same as the monomer used in the polymer (I), polybutadiene-based rubber 2 has a 1,4-cis content of 40% by weight or less, 95 parts by weight of styrene monomer and 5 parts by weight of the The viscosity of the rubber solution which consists of polybutadiene-type rubber 2 is 155-185 centipoise level. Polymer (II) polymerized in the R-1-2 reactor has a rubber particle diameter of 1.5 to 2.0 mu m.

In the R-1-3 reactor, the styrene monomer and the polybutadiene rubber 3 are mixed and polymerized at 110 to 140 ° C. for 1.5 to 2.5 hours at a conversion rate of 20 to 30%. In this case, the styrene monomer used is the same as the monomer used in the polymer (I), polybutadiene-based rubber 3 has a 1,4-cis content of 45% by weight or less, 95 parts by weight of styrene monomer and 5 parts by weight of the The viscosity of the rubber solution consisting of polybutadiene-based rubber 3 is 190 to 250 centipoise. Polymer (II) polymerized in the R-1-2 reactor has a rubber particle diameter of 3.5 to 4.5 µm.

The polymer (I), the polymer (II), and the polymer (III) are mixed and then further polymerized to prepare in the R-2 reactor and the R-3 reactor.

That is, the polymer (I), the polymer (II), and the polymer (III) introduced into the R-2 reactor are polymerized at 150 to 180 ° C. for 1 to 2 hours, at 35% conversion of mineral oil, antioxidant, and A molecular weight modifier is added to achieve a conversion of 45-50%. The silicone oil is introduced into the middle line between the R-2 and R-3 reactors, the polymer containing the silicone oil is introduced into the R-3 reactor, and polymerized at 170 to 200 ° C. for 0.5 to 1.5 hours, thereby converting between 70 and 70%. 75%.

The silicone oil used in the present invention has a viscosity of 500,000 to 1,000,000 centistokes at room temperature.

The silicone oil is used in an amount of 0.5 to 1.5 parts by weight based on 100 parts by weight of the total resin composition. If the amount is less than 0.5 parts by weight, the abrasion resistance is lowered, and a process difficulty occurs in excess of 1.5 parts by weight.

The devolatilizer recovers unreacted monomers and sends them to a condensation condenser. When the process is completed, a high impact polystyrene (HIPS) resin having a conversion rate of 99.9% is prepared. The high impact polystyrene (HIPS) resin prepared as described above contains silicone oil and rubber particles are dispersed in a trimodal form.

The high impact polystyrene resin of the present invention may be more clearly understood by the following examples, which are only illustrative purposes of the present invention and are not intended to limit the scope of the present invention.

Example

Preparation of Polymer (I) with Rubber Particles of 0.3 to 0.6 µm in Diameter

91.5 parts by weight of styrene monomer and 8.5 parts by weight of polybutadiene-based rubber 1 were added, and 0.08 parts by weight of tertiary butyl peroxyacetate was added as an initiator, followed by polymerization at 116 ° C. for 2 hours to synthesize a polymer having a conversion ratio of 27%. At this time, the diameter of the rubber particles was 0.3 ~ 0.6 ㎛.

Preparation of Polymer (II) with Rubber Particles of 1.5 to 2.0 µm in Diameter

91.5 parts by weight of styrene monomer and 8.5 parts by weight of polybutadiene-based rubber 2 were added, and 0.07 parts by weight of tertiary butyl peroxyacetate was added as an initiator, followed by polymerization at 115 ° C. for 2 hours to synthesize a polymer having a conversion ratio of 26%. At this time, the diameter of the rubber particles was 1.5 to 2.0 ㎛.

Preparation of Polymer (III) with Rubber Particles of 3.5 to 4.5 µm in Diameter

91.5 parts by weight of styrene monomer and 8.5 parts by weight of polybutadiene-based rubber 3 were added, and 0.06 parts by weight of tertiary butyl peroxyacetate was added as an initiator, followed by polymerization at 116 ° C. for 2 hours to synthesize a polymer having a conversion ratio of 25%. At this time, the diameter of the rubber particles was 3.5 to 4.5 ㎛.

Example 1 Polymerization of High Impact Polystyrene Resin

5 parts by weight of polymer (I) (conversion rate 27%), 85 parts by weight of polymer (II) (conversion rate 26%), and 10 parts by weight of polymer (III) (conversion rate 25%) synthesized by the above method were mixed. Rubber dispersed in the resin by polymerization of 1.5 parts by weight of mineral oil, 0.05 parts by weight of antioxidant, 0.08 parts by weight of molecular weight regulator, and 0.5 parts by weight of silicone oil, and polymerization so that the conversion rate is 99.9% using the bulk polymerization continuous process shown in FIG. HIPS having a rubber content of 8.5% by weight while having a particle size of trimodal form was prepared. After the injection molding machine by injection molding the test specimen, the physical properties were measured and the results are shown in Table 1.

Example 2 Polymerization of High Impact Polystyrene Resin

It carried out similarly to Example 1 except using 10 weight part of polymers (I), 70 weight part of polymers (II), 20 weight part of polymers (III), and 1.0 weight part of silicone oil. As a result, HIPS having a rubber particle size of trimodal form and rubber content of 8.5% was prepared, and the results are shown in Table 1 below.

Example 3 Polymerization of High Impact Polystyrene Resin

It carried out similarly to Example 1 except using 15 weight part of polymers (I), 80 weight part of polymers (II), 5 weight part of polymers (III), and 1.5 weight part of silicone oil. As a result, HIPS having a rubber particle size of trimodal form and rubber content of 8.5% was prepared, and the results are shown in Table 1 below.

Comparative Example 1

It carried out similarly to Example 1 except using 50 weight part of polymers (I), 50 weight part of polymers (II), and 0.1 weight part of silicone oil. As a result, HIPS having a rubber particle size of bimodal form and rubber content of 8.5% was prepared, and the results are shown in Table 1 below.

Comparative Example 2

It carried out similarly to Example 1 except using 50 weight part of polymers (I), 50 weight part of polymers (III), and 0.1 weight part of silicone oil. As a result, HIPS having a rubber particle size of bimodal form and rubber content of 8.5% was prepared, and the results are shown in Table 1 below.

Comparative Example 3

It carried out similarly to Example 1 except using 50 weight part of polymers (II), 50 weight part of polymers (III), and 0.1 weight part of silicone oil. As a result, HIPS having a rubber particle size of bimodal form and rubber content of 8.5% was prepared, and the results are shown in Table 1 below.

Comparative Example 4

The same process as in Example 1 was carried out except that 100 parts by weight of polymer (I) and 0.3 parts by weight of silicone oil were used. As a result, HIPS with a rubber particle size of monomodal form and rubber content of 8.5% was prepared, and the results are shown in Table 1 below.

Comparative Example 5

The same procedure as in Example 1 was carried out except that 100 parts by weight of polymer (II) and 0.3 parts by weight of silicone oil were used. As a result, HIPS with a rubber particle size of monomodal form and rubber content of 8.5% was prepared, and the results are shown in Table 1 below.

Comparative Example 6

It carried out similarly to Example 1 except using 100 weight part of polymers (III) and 0.3 weight part of silicone oils. As a result, HIPS with a rubber particle size of monomodal form and rubber content of 8.5% was prepared, and the results are shown in Table 1 below.

Example Comparative example One 2 3 One 2 3 4 5 6 Composition Polymer I (parts by weight) 5 10 15 50 50 0 100 0 0 Polymer II (parts by weight) 85 70 80 50 0 50 0 100 0 Polymer III (parts by weight) 10 20 5 0 50 50 0 0 100 Silicone oil (parts by weight) 0.5 1.0 1.5 0.1 0.1 0.1 0.3 0.3 0.3 Rubber content (% by weight) 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 water                                                                                                    castle Tensile Strength (kgcm / kg) 302 314 327 331 319 305 338 312 295 % Elongation 94 98 87 58 69 105 51 99 112 Fluidity (g / 10min) 3.5 3.6 3.4 3.4 3.6 3.4 3.5 3.5 3.4 Drop impact strength (Joule) 21.3 19.8 18.9 7.6 10.6 8.9 1.8 11.4 7.9 Resin wear amount (mg) 0.16 0.1 0.04 2.55 2.55 2.55 1.86 1.86 1.86 Static friction coefficient 0.15 0.11 0.05 0.98 0.98 0.98 0.76 0.76 0.76 Dynamic friction coefficient 0.15 0.11 0.05 0.98 0.98 0.98 0.76 0.76 0.76

Tensile strength was measured by ASTM D638 (test speed: 20 mm / min), and elongation was measured by ASTM D638 (test speed: 20 mm / min). The fluidity was evaluated by ASTM D1238 (200 ° C., 5 kg) and the drop impact strength by JIS K7211. The test conditions for the amount of resin wear are as follows:

① Wear ring material: CS-17 ② Test load: 1kg / ㎠

③ Test time: 60 minutes ④ Test speed: 200RPM, 60cm / sec

The physical property measurement results are as shown in Table 1, in the case of Examples 1 to 3 containing 0.5 to 1.5 parts by weight of silicone oil and introducing three kinds of rubber particles having different diameters, the wear resistance is excellent and the rubber particles are trimodal in the polystyrene resin. Although dispersed in the form of excellent drop impact strength, Comparative Examples 1 to 6 containing less than 0.5 parts by weight of silicone oil and the rubber particles introduced into the resin in the form of mono-modal or bi-modal is bad wear resistance and drop impact strength It can be seen that is significantly reduced.

The high impact polystyrene resin of the present invention prepares three kinds of polymers having different diameters of rubber particles, and polymerizes them again to disperse the rubber particles in a trimodal form and to contain high viscosity silicone oil to reduce impact strength and wear resistance. This has an excellent effect.

Simple modifications and variations of the present invention can be readily used by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

Claims (5)

5 to 15 parts by weight of polymer (I) of styrene-based monomer and polybutadiene-based rubber 1 having a rubber particle diameter of 0.3 to 0.6 µm; 70 to 85 parts by weight of polymer (II) of styrene monomer and polybutadiene rubber 2 having a rubber particle diameter of 1.5 to 2.0 µm; And 5 to 20 parts by weight of polymer (III) of styrene-based monomer and polybutadiene rubber 3 having a diameter of 3.5 to 4.5 µm of rubber particles, and further polymerize 0.5 to 1.5 parts by weight of silicone oil, High impact polystyrene resin, characterized in that the dispersed rubber particles have a trimodal form. The high impact polystyrene resin according to claim 1, wherein the styrene monomer is selected from the group consisting of styrene, α-methyl styrene, α-ethyl styrene, and ρ-methyl styrene. According to claim 1, wherein the polybutadiene-based rubber 1 has a 1,4-cis content of 43% by weight or less, the viscosity of the rubber solution mixed with 95% by weight of the styrene monomer is 40 to 60 centipoise; The polybutadiene rubber 2 has a 1,4-cis content of 40 wt% or less, and a viscosity of the rubber solution mixed with 95 wt% of a styrene monomer is 155 to 185 centipoise; And The polybutadiene rubber 3 has a 1,4-cis content of 45% by weight or less and a high impact polystyrene resin having a viscosity of 190 to 250 centipoise of a rubber solution mixed with 95% by weight of a styrene monomer. . The polymer (I), the polymer (II), and the polymer (III) according to any one of claims 1 to 3, respectively, are polymerized at 110 to 140 DEG C with a conversion rate of 20 to 30% for 1.5 to 2.5 hours. High impact polystyrene resin, characterized in that. The high impact polystyrene resin of claim 1, wherein the silicone oil has a viscosity of 500,000 to 1,000,000 centistokes at room temperature.

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