KR100769463B1 - Syndiotactic Polystyrene Resin Composition with Improved Impact Strength and Method of Preparing Same - Google Patents

Abstract

Syndiotactic polystyrene resin composition according to the present invention comprises (A) 45 to 97 parts by weight of syndiotactic polystyrene resin, (B) 1 to 20 parts by weight of ethylene-vinyl-acetate copolymer (EVA) (C) polyphenylene oxide (C ₁ ), _{1 to} 15 parts by weight of reactive polystyrene (RPS) (C ₂ ) or a combination thereof, and (D) hydrogenated styrene / butadiene / styrene block copolymer (SEBS), hydrogen as an impact modifier of rubber component Addition of additional reactive ethylene-glycidyl methacrylate (E-GMA) copolymer to 1 to 20 parts by weight of styrene / butadiene / styrene-graft-maleic anhydride (SEBS-MA) or a combination thereof To prepare.

Syndiotactic polystyrene, ethylene-vinyl-acetate (EVA), polyphenylene oxide (PPO), reactive polystyrene (RPS), impact modifier, impact strength

Description

Syndiotactic Polystyrene Resin Composition with Improved Impact Strength and Method of Preparing Same}

1 to 4 are cross-sectional photographs of specimens injected with the resin composition prepared in Examples 4 to 7 according to the present invention.

Field of invention

The present invention relates to a syndiotactic polystyrene resin composition having excellent impact characteristics. More specifically, the present invention relates to ethylene-vinyl-acetate copolymer (EVA), (C) polyphenylene oxide (PPO), and / or (B) a thermoplastic resin based on (A) syndiotactic polystyrene resin (sPS). Or it relates to a resin composition exhibiting excellent impact characteristics consisting of the reactive polystyrene (RPS), and the impact modifier of the rubber component (D).                         

Background of the Invention

Syndiotactic polystyrene is a crystalline polystyrene having high heat resistance temperature and high mechanical properties but low impact characteristics. In order to compensate for these drawbacks, rubber reinforcing materials and various compatibilizers have been introduced to solve this problem. 5,352,727 and EP 0 978 536 A1 and the like. The impact characteristics of the sPS disclosed in these patents are Izod test values from 10 kgcm / cm up to 30 kgcm / cm, whereas the mechanical properties are lower than the syndiotactic polystyrene itself, and the flexural strength is 20,000 ~. 25,000 kgf / cm 2 level is shown.

In order to reinforce the impact of sPS resin, there are two methods of compensating elasticity through simple kneading with rubber component or improving the interface property between rigid syndiotactic polystyrene and rubber component to prevent phase separation. Can be classified. However, the latter case, rather than the former, may be a preferable method for formability and reproducibility of physical properties.

With respect to the syndiotactic polystyrene resin composition having excellent impact resistance, the present applicant has already filed as Korean Patent Application No. 99-26623 (July 2, 1999). This domestic patent application uses syndiotactic polystyrene-maleic anhydride (sPS-MA) and hydrogenated styrene-butadiene-styrene maleic anhydride (SEBS-MA) and adds diamine compound to the main ingredient. Disclosed is a method for increasing the impact strength by improving the interfacial properties between syndiotactic polystyrene and other polymers by imparting polarity to both syndiotactic polystyrene and added rubber components and connecting them with diamine compounds. Doing.

Until now, syndiotactic polystyrene is a crystalline polystyrene, which has high heat resistance and high rigidity, but has low impact characteristics. Therefore, in order to compensate for this, in many cases, it is necessary to reinforce the rubber component that can enhance the impact. The purpose of the present invention is to obtain a composition exhibiting particularly excellent impact characteristics, which maximizes the kneading performance through the optimized mixing of the components. In the present invention, while using the above-described SEBS, by using an ethylene-vinyl-acetate copolymer (EVA) as a polyolefin resin, it is to develop an optimal composition that can maximize the impact characteristics.

An object of the present invention is to provide a syndiotactic polystyrene (sPS) resin composition with improved impact strength using EVA excellent in impact properties.

Another object of the present invention is to provide a syndiotactic polystyrene resin composition which is advantageous in terms of the production cost of the final compound.

Another object of the present invention is to provide a syndiotactic polystyrene resin composition which can be expected to be compatible with additional polyolefins and styrene resins when the base compound is expanded to other new compounds by maximizing the impact strength. .

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

Summary of the Invention

Syndiotactic polystyrene resin composition according to the present invention comprises (A) 45 to 97 parts by weight of syndiotactic polystyrene resin, (B) 1 to 20 parts by weight of ethylene-vinyl-acetate copolymer (EVA) (C) polyphenylene oxide (C ₁ ), _{1 to} 15 parts by weight of reactive polystyrene (RPS) (C ₂ ) or a combination thereof, and (D) hydrogenated styrene / butadiene / styrene block copolymer (SEBS), hydrogen as an impact modifier of rubber component Addition of additional reactive ethylene-glycidyl methacrylate (E-GMA) copolymer to 1 to 20 parts by weight of styrene / butadiene / styrene-graft-maleic anhydride (SEBS-MA) or a combination thereof To prepare.

Detailed Description of the Invention                     

It is known that a resin composition based on syndiotactic polystyrene based on hydrogenerated styrene-butadiene-styrene (SEBS) and polyphenylene oxide (PPO) has an effect on improving impact. However, in the present invention, in addition to reactive polystyrene for modifying syndiotactic polystyrene, which is a matrix, in order to optimize EVA and select EVA among polyolefin resins in consideration of economical aspects of production cost in the resin composition which is the basis of impact improvement, Was added. In addition, all of the blends were subjected to continuous operation with a twin screw extruder to facilitate commercialization, and pellets were obtained. EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the resin composition of this invention is described in detail.

(A) Syndiotactic Polystyrene (sPS)

Syndiotactic polystyrene is polymerized in a catalyst system consisting of a novel metallocene catalyst and a cocatalyst. The metallocene catalyst has a structure in which an auxiliary ligand of a transition metal compound and a functional group of the compound are linked to each other, and vary greatly depending on the kind of the transition metal compound or the kind of the compound having two or more functional groups and the molar ratio of each reactant. May exist in the form.

The syndiotactic structure is a stereodiode structure having a stereodiode in which a phenyl group, which is a side chain with respect to a main chain formed of a carbon-carbon bond, is alternately located in the opposite direction, and its tacticity is isotope It is quantified by carbon nuclear resonance ( ¹³ C-NMR). Tacticity measured by ¹³ C-NMR can be expressed as abundance of a plurality of consecutive units, such as diamond in two cases, triad in three cases, and pentad in five cases. Syndiotactic polystyrene polymer as used herein refers to polystyrenes having syndiotacticity of at least 75%, preferably at least 85%, or at least 30%, preferably at least 50%, with racemicdia.

(B) ethylene-vinyl-acetate copolymer (EVA)

Ethylene-vinyl acetate copolymer (EVA) is excellent in elasticity in the polyolefin resin, it is easy to utilize its own rubber properties, and can control the degree of polarity by the vinyl-acetate content is advantageous for further blend production.

(C) polyphenylene oxide (PPO) (or polyphenylene ether (PPE)) (C ₁ ) and / or reactive polystyrene (RPS) (C ₂ )

(C ₁ ) polyphenylene oxide (PPO) (or polyphenylene ether (PPE))

PPO is added to increase the compatibility of syndiotactic polystyrene with the rubber component, an impact modifier. PPO is a known compound, usually prepared by an oxidative coupling reaction which produces a homopolymer or heteropolymer in the presence of a copper amine complex, at least one two or three substituted phenols. The copper amine complex here may use a copper amine complex derived from the first, second and / or third amines. Examples of PPO include poly (2,3-dimethyl-6-ethyl-1,4-phenylene ether), poly (2-methyl-6-chloromethyl-1,4-phenylene ether), poly (2-methyl -6-hydroxyethyl-1,4-ferene ether), poly (2-methyl-6-n-butyl-1,4-phenylene ether), poly (2-ethyl-6-isopropyl-1,4 -Phenylene ether), poly (2-ethyl-n-propyl-1,4-phenylene ether), poly (2,3,6-trimethyl-1,4-phenylene ether), poly (2-ethyl ( 4'-methylphenyl) -1,4-phenylene ether), poly (2-bromo-6-phenyl-1,4-phenylene ether), poly (2-methyl-6-phenyl-1,4-phenyl Lene ether), poly (2-phenyl-1,4-phenylene ether), poly (2-chloro-1,4-phenylene ether), poly (2-methyl-1,4-phenylene ether), poly (2-chloro-6-ethyl-1,4-phenylene ether), poly (2-chloro-6-bromo-1,4-phenylene ether), poly (2,6-di-n-propyl- 1,4-phenylene ether), poly (2-methyl-6-isopropyl-1,4-phenylene ether), poly (2-chloro-6-methyl-1,4-phenylene ether), poly ( 2-methyl-6-ethyl-1,4-phenyl Lene ether), poly (2,6-dichloro-1,4-phenylene ether), poly (2,6-diethyl-1,4-phenylene ether), poly (2,6-dimethyl-1,4 -Phenylene ether), poly (2,6-dibromo-1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether), and the like. In addition, copolymers derived from two or more kinds of phenolic compounds such as those used for preparation of the homopolymer may be used. Moreover, what modified | denatured these with the denaturing agent including maleic anhydride, a fumic acid, etc. is used. Especially preferred among these are poly (2,6-dimethyl-1,4-phenylene ether).

(C ₂ ) reactive polystyrene (RPS)

Reactive polystyrene (RPS) may be used instead of the PPO, and RPS may be used together with PPO. RPS is used for the purpose of inducing polarization of the matrix, syndiotactic polystyrene. A representative example of reactive polystyrene (RPS) is oxazoline-containing polystyrene.

(D) Rubber component

Hydrogenated Styrene / Butadiene / Styrene Block Copolymer (SEBS) is a rubber component that is added to increase the impact strength of syndiotactic polystyrene, and has a high molecular weight and excellent moldability at high temperatures (about 300 ° C). This is suitable. Hydrogenated styrene-butadiene-styrene maleic anhydride (SEBS-MA) may be used instead of SEBS as the impact modifier.

(E) Other ingredients

Ethylene-glycidyl methacrylate (E-GMA): This is a copolymer, as described above, the ethylene block has affinity with polyolefins and glycidyl methacrylate has a carboxyl group (-COOH), a hydroxyl group (- and containing a polar group that has reactivity with a functional group such as OH), amine group (-NH _2).

Inorganic fillers: fibrous, granular, powdery or not a problem. Glass fibres, carbon fibers, whiskers, etc. are recommended as fibrous fillers. The shape includes a cloister shape, a mat shape, a focusing cut shape, a short fiber, a filament shape, a whisker and the like. However, in the case of a connection cut shape, the length is preferably 0.05 to 50 mm and the fiber diameter is 5 to 20 μm. Moreover, as these fillers, what was surface-treated is preferable. The coupling agent used for the surface treatment is used to improve adhesion between the filler and the resin, and for example, a silane coupling agent or a titanium coupling agent may be arbitrarily selected and used. On the other hand, as granular and powdery fillers, for example, talc, carbon black, graphite, titanium dioxide, mica, silica, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, oxalate, tin oxide, alumina, kaolin , Silicon carbide, metal powder, glass powder, glass flakes, glass beads, etc. are suitable. Among such fillers, in particular glass fillers such as glass powder, glass flakes, glass beads, glass filaments, glass beads and the like are recommended.

Syndiotactic polystyrene resin composition of the present invention, if necessary, antioxidants, nucleating agents, plasticizers, processing aids, heat stabilizers, light stabilizers, flame retardants, flame retardant aids, thermoplastic resins and dyes, pigments in a range that does not impair the object of the present invention , Additives such as an antistatic agent can be blended. In addition, about each of these, only 1 type can be used individually or in combination of 2 or more types.

Antioxidant: It can select arbitrarily from well-known things, such as phosphorus type, a phenol type, and sulfur type.

Nucleating agents: Nucleating agents may be prescribed to promote crystallization of syndiotactic polystyrene. Nucleating agents include metal salts of carboxylic acids, including aluminum di (p-tert-butylbenzoate), metal phosphates salts of methylenebis (2,4-di-tert-butylphenol) acid phosphate, talc, It can be used selecting arbitrarily from well-known things, such as a procyanine derivative.

Plasticizer: Polyethylene glycol, polyamide oligomer, ethylenebis stearamide, phthalic acid ester, polystyrene oligomer, polyethylene wax, mineral oil, silicone oil and the like can be arbitrarily selected and used.

Release agent: It can select arbitrarily from well-known things, such as polyethylene wax, silicone oil, long chain carboxylic acid, and long chain carboxylic acid metal salt.

Flame retardants and flame retardants: Flame retardants include silicified polymers including silicified polystyrenes, silicated syndiotactic polystyrenes, silicified polyphenylene ethers, silicified diphenylalkanes and silicified diphenyl ethers It can select arbitrarily from a well-known thing, such as an aromatic compound, a tricredyl oxate, a triphenyl oxate, and a phosphorus flame retardant including a tris-3-chloropropyl oxate. Moreover, as a drip prevention agent, it can select arbitrarily and can use from well-known things, such as Teflon.

Thermoplastics: linear high density polyethylene (HDPE), linear low density polyethylene (LLDPE), high pressure low density polyethylene (LDPE), isotactic polypropylene, syndiotactic polypropylene, block polypropylene, random polypropylene, polybutene, 1 Polyolefin resins including polyolefin resins, including poly-polybutadiene, cyclic polyolefins, poly-4-methyl pentene, and high-impact polystyrene (HIPS), polystyrene resins including ABS, SMA, polycarbonate (PC), polyethylene Polyester resins starting with terephthalate (PET) or polybutylene terephthalate (PBT), polyamide 6 or polyamide resins starting with polyamide 6,6, polyarylene sulfide resins and the like. Can be used arbitrarily selected.

The other additives are selected according to the respective uses, and their contents may be easily carried out by those skilled in the art to which the present invention pertains.

The method for preparing the styrene resin composition according to the present invention is not particularly limited and can be prepared by a known method. For example, the resin composition of the present invention may be obtained by melting the above components and various additives using a ribbon blender, Henschel mixer, Banbury mixer, drum tumbler, single screw extruder, twin screw extruder, simultaneous kneader, multi screw extruder and the like. Can be.

It is preferable that the temperature of the molten resin is properly maintained at 240 to 280 ° C. in consideration of the heat of the resin so that the temperature of the resin becomes 290 ° C. or more so that thermal decomposition does not occur.

In the embodiment of the present invention, compounding based on about 3 kg using a twin screw extruder, which is one of the continuous processes, so that commercialization can be easily induced, all the compositions were pelletized.

The molding method of the styrene resin composition according to the present invention is not particularly limited, and may be molded by a known method such as injection molding or extrusion molding. The processing temperature during molding should be higher than the melting point of syndiotactic polystyrene based on the resin temperature, but not too high so as not to be higher than 300 ° C. If the melting point is lower than 270 ° C, the surface appearance of the molded product will be deteriorated. In addition, productivity may be lowered due to a decrease in flowability.

Syndiotactic polystyrene composition of the present invention can be more clearly understood by the following examples, the following examples are merely illustrative purposes of the present invention and are not intended to limit the scope of the invention.

Example

(A) Syndiotactic Polystyrene (sPS), (B) Ethylene-Vinyl Acetate Copolymer (EVA), (C) Polyphenylene Oxide (PPO) and Li used in the resin compositions of Examples 1-7 below Active polystyrene (RPS: Oxazoline), (D) hydrogenated styrene / butadiene / styrene block copolymer (SEBS) and / or hydrogenated styrene / butadiene / styrene-graft-maleic hydride (SEBS-MA), and ( E) Specifications of ethylene-glycidyl methacrylate (E-GMA) etc. as other components are as follows.

(A) Syndiotactic Polystyrene (sPS)

In order to control the morphology of the resulting polymer, it was polymerized in a laboratory scale glass reactor to obtain polystyrene having a syndiotacticity of 97% or more (weight average molecular weight: 400,000 to 600,000, molecular weight distribution: 2.7).

(B) Ethylene-Vinyl Acetate Copolymer (EVA)

E180F, a commercial product of Samsung General Chemicals, was used.

(C) polyphenylene oxide (PPO) and reactive polystyrene (RPS: Oxazoline)

(C ₁ ) polyphenylene oxide (PPO)

As the PPO, P401, a commercial product of Asahi Corp., was used.

(C ₂ ) Reactive Polystyrene (RPS: Oxazoline)

Epocros 1005 (Oxazoline 5%) from Shokubai, Japan, was used.

(D) Hydrogenated Styrene / Butadiene / Styrene Block Copolymer (SEBS)

SEBS was used as Kraton G-1651, a commercial product from Shell. As hydrogenated styrene / butadiene / styrene-graft-maleic anhydride (SEBS-MA), a commercial product of M-1913, a Japanese company, was used.

(E) Other ingredients

As ethylene-glycidyl methacrylate (E-GMA), Lotader AX-8840 (MI: 5, GMA content: 8%), commercialized by Atofina, was used.

Molding of the resin composition of the embodiment was extruded pelletized using a twin screw extruder (32mmΦ, L / D-40) in the form of a continuous process, 1% styrene antioxidant (primary, secondary) before kneading Was added and extruded at 135 rpm (rotation per minute) at a barrel temperature of 240 to 280 ° C., which was injection molded at 300 ° C. and then cooled to 100 ° C. in a mold to obtain tensile strength / flexural strength / impact strength / heat Simultaneously prepared specimens capable of measuring strain temperature were prepared. The physical properties of the prepared specimens were measured according to the standard (ASTM D-638 / 790/256).

Example 1-3

In the basic experiment according to the present invention, the experiment was conducted to determine the singularity of the physical properties depending on the addition of each component, and the impact resistance was improved to a strength of more than 10 kgf / ㎠ in some compositions. Table 1 shows the molding conditions of the twin-screw extruder for each resin composition. The injection-molded specimens of the resin composition prepared from pellets were granulated, and the content of the components and the measurement results are shown in Table 2.

Item Raw material Example 1 Example 2 Example 3 Processing temperature (℃) Set Real Set Real Set Real C1 160 160 160 160 160 160 C2 190 190 190 190 190 190 C3 210 209 210 210 210 210 C4 240 240 240 243 240 240 C5 260 260 260 259 260 260 C6 260 260 260 260 260 260 C7 270 271 270 271 270 270 C8 270 270 270 270 270 270 C9 270 269 270 270 270 270 AD 270 270 270 269 270 270 Die 260 261 260 261 260 260 Main Motor (rpm) Main Screw (rpm) Extrusion Load (A) 904-9 134-5 14 905-9 134-5 14 904-9 134-5 14 Feeder screw speed (rpm) 18 18 18 Side feeder speed (rpm) 16 16 16 Resin Temperature (℃) 287 287 287 Resin Pressure (㎏ / ㎠) 17-8 17 17-18 Coolant temperature (℃) 40 40 40 Cutter Speed (rpm) Cutter Load (A) 458 24-25 458 25 458 24-25

 division  sPS pellet  PPO P401  RPS 1005  SEBS G-1651  SEBS-MA M-1913  EVA E180F  Flexural Strength (㎏f / ㎠)  Impact strength (kgfcm / cm) Tensile Strength (㎏f / ㎠)  Elongation (%)  HDT (℃) Example 1 76 4 - 8 4 8 25,080 10.9 379 8 92.0 Example 2 76 - 4 8 4 8 24,740 8.9 380 8 89.2 Example 3 80 4 - 8 - 8 27,920 4.0 501 4 94.1

Example 4-7

Reflecting the results of Example 1-3 and using the RPS for further polarization of the sPS, and experimented by optimizing the resin composition by slightly changing the rubber component and EVA content, the impact characteristics of the impact strength of 10 or more in the two compositions The visible resin composition was obtained. 1 to 4 show photographs of SEM measurement results of cross sections broken in liquid nitrogen for the samples of Examples 4-7, respectively, for cross-sectional observation of the specimens having the above impact properties. As can be seen from the picture, it can be seen that the size and dispersion degree of the rubber component is better than the case of the fracture surface having impact resistance properties (Examples 4 and 5). Table 3 shows the molding conditions of the twin-screw extruder for each resin composition, granulated the injection-molded specimen of the resin composition prepared from pellets, and the results of component content and physical properties are shown in Table 4.

Item Raw material Example 4 Example 5 Example 6 Example 7 Processing temperature (℃) Set Real Set Real Set Real Set Real C1 160 162 160 160 160 160 160 160 C2 190 193 190 190 190 190 190 190 C3 210 210 210 210 210 210 210 210 C4 240 244 240 237 240 239 240 238 C5 260 258 260 259 260 260 260 260 C6 260 260 260 260 260 260 260 260 C7 270 270 270 269 270 270 270 270 C8 270 272 270 270 270 270 270 270 C9 270 272 270 270 270 270 270 270 AD 270 272 270 270 270 270 270 270 Die 260 260 260 260 260 260 260 261 Main Motor (rpm) Main Screw (rpm) Extrusion Load (A) 905 134-5 14-15 904-907 134-135 14 904-908 134 14 904-909 134 14 Feeder screw speed (rpm) 18 17-18 17-18 17-18 Side feeder speed (rpm) 16 16 16 16 Resin Temperature (℃) 290 290 290 289 Resin Pressure (㎏ / ㎠) 14 13-14 11-12 12-14 Coolant temperature (℃) 38 39 35 36 Cutter Speed (rpm) Cutter Load (A) 444 to 450 26 459 26 459 25 558 27

 division  sPS pellet  PPO P401  RPS 1005  SEBS G-1651  SEBS-MA M-1913  EVA E180F  Flexural Strength (㎏f / ㎠)  Impact strength (kgfcm / cm) Tensile Strength (㎏f / ㎠)  Elongation (%)  HDT (℃) Example 4 72 4 4 12 4 4 23,390 19.5 406 8 96.0 Example 5 72 4 4 8 4 8 22,910 11.2 400 9 96.0 Example 6 72 4 6 4 4 10 24,780 5.5 478 4 96.6 Example 7 72 4 6 - 6 12 24,990 4.1 525 4 96.9

The present invention adds a new compatibilizer and maximizes the kneading property, so that the impact properties as well as other mechanical properties are excellent, and also advantageous in terms of production cost of the final compound, and maximizes the impact strength of the base compound to other new compounds. It has the effect of the invention to provide a syndiotactic polystyrene resin composition which can be expected to be compatible with additional polyolefin and styrenic resin upon development of and a method for producing the same.

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 (4)

(A) 45 to 97 parts by weight of syndiotactic polystyrene resin; (B) 1 to 20 parts by weight of ethylene-vinyl-acetate copolymer (EVA); (C) 1 to 15 parts by weight of reactive polystyrene (RPS); And (D) hydrogenated styrene / butadiene / styrene block copolymer (SEBS), hydrogenated styrene / butadiene / styrene-graft-maleic hydride (SEBS-MA) or mixtures thereof 1 to 20 parts by weight of impact reinforcing material; Syndiotactic polystyrene resin composition having excellent impact characteristics, comprising a. The syndiotactic polystyrene resin composition having excellent impact characteristics according to claim 1, wherein the reactive polystyrene is oxazoline-containing polystyrene. (A) 45 to 97 parts by weight of syndiotactic polystyrene resin; (B) 1 to 20 parts by weight of ethylene-vinyl-acetate copolymer (EVA); (C) _{1 to} 15 parts by weight of polyphenylene oxide (C ₁ ), reactive polystyrene (RPS) (C ₂ ) or a combination thereof; And (D) Impact characteristics characterized by further adding an ethylene-glycidyl methacrylate (E-GMA) copolymer or thermoplastic resin to the syndiotactic polystyrene resin composition comprising 1 to 20 parts by weight of the impact modifier of the rubber component. The manufacturing method of this excellent syndiotactic polystyrene resin composition. The impact characteristic according to claim 3, further comprising an inorganic filler, an antioxidant, a nucleating agent, a plasticizer, a processing aid, a heat stabilizer, a light stabilizer, a flame retardant, a flame retardant aid, a dye, a pigment, an antistatic agent or a combination thereof. The manufacturing method of this excellent syndiotactic polystyrene resin composition.

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