Polypropylene-based resin composition

Abstract

The present invention relates to a polypropylene-based resin composition which exhibits mechanical properties such as excellent strength and more improved impact strength, and a molded article comprising the same. The polypropylene-based resin composition comprises: a polypropylene-based resin; and an olefin-based copolymer, and shows two or more elution temperatures at a predetermined temperature range when analyzing the olefin-based copolymer by temperature rising elution fractionation (TREF).

Claims

1. polypropylene-based resin composition comprising: a polypropylene-based resin; and an olefin-based copolymer containing an ethylene repeating unit, and an alpha-olefin-based repeating unit having 4 or more carbon atoms, wherein the olefin-based copolymer shows a single peak when analyzed by gel permeation chromatography, and shows three elution temperatures, Te1, Te2 and Te3, in a temperature range of 20 C. to 120 C. when analyzed by temperature rising elution fractionation (TREF), wherein the Te1 is present at a lower temperature than the Te2 and the Te2 is present at a lower temperature than the Te3, and the Te1 is 20 C. to 100 C., the Te2 is 0 C. to 120 C., and the Te3 is 20 C. to 120 C., wherein the olefin-based copolymer includes a first semi-crystalline olefin-based copolymer, a second semi-crystalline olefin-based copolymer and a third semi-crystalline olefin-based copolymer, and wherein when the olefin-based copolymer has been analyzed by TREF, a fraction ratio of a peak corresponding to the Te1 for the first semi-crystalline olefin copolymer is 30 to 80%, a fraction ratio of a peak corresponding to the Te2 for the second semi-crystalline olefin copolymer is 5 to 40%, and a fraction ratio of a peak corresponding to the Te3 for the third semi-crystalline olefin copolymer is 5 to 50%.

2. The polypropylene-based resin composition according to claim 1, wherein the olefin-based copolymer further satisfies the following requirements (1) to (3): (1) Density measured according to ASTM D-792: 0.850 to 0.910 g/cc, (2) Melt index measured at 190 C. under a load of 2.16 kg: 0.1 to 100 g/10 min, and (3) Molecular weight distribution: 1.5 to 4.0.

3. The polypropylene-based resin composition according to claim 1, wherein the olefin-based copolymer has a density measured according to ASTM D-792 of 0.86 to 0.88 g/cc, the Te1 is 20 C. to 30 C., the Te2 is 10 C. to 80 C., and the Te3 is 40 C. to 120 C.

4. The polypropylene-based resin composition according to claim 1, wherein the olefin-based copolymer has three crystallization temperatures (Te1, Te2, Te3) in DSC curve, Te1 is 5 C. or less, Te2 is 0 C. to 60 C., and Te3 is 80 C. to 130 C.

5. The polypropylene-based resin composition according to claim 1, wherein the olefin-based copolymer has a weight average molecular weight (Mw) of 10,000 to 500,000 g/mol.

6. The polypropylene-based resin composition according to claim 1, wherein the polypropylene-based resin comprises at least one of polypropylene homopolymer, propylene-alpha-olefin copolymer, or propylene-ethylene-alpha-olefin copolymer.

7. The polypropylene-based resin composition according to claim 1, wherein the composition comprises 50 to 90% by weight of the polypropylene-based resin and 10 to 50% by weight of the olefin-based copolymer.

8. The polypropylene-based resin composition according to claim 1, wherein the alpha-olefin-based repeating unit is a repeating unit derived from one or more alpha-olefins selected from the group consisting of 1-butene, 1-pentene, 1-hexene, 1-heptene 1-octene, 1-decene, 1-unclecene, 1-dodecene, 1-tetradecene and 1-hexadecene.

9. A molded product comprising the polypropylene-based resin composition of claim 1.

10. The polypropylene-based resin composition according to claim 1, wherein the olefin-based copolymer has a molecular weight distribution (MWD) of 1.5 to 4.0.

11. The polypropylene-based resin composition according to claim 1, wherein the olefin-based copolymer is prepared by a method comprising the step of copolymerizing ethylene and alpha-olefin in the presence of a catalyst composition comprising a transition metal compound of the following Chemical Formula 1 and a transition metal compound of the following Chemical Formula 2: ##STR00010## in Chemical Formulae 1 and 2, M.sub.1 and M.sub.2 are each independently a Group 4 transition metal, Q.sub.1, Q.sub.2, Q.sub.3 and Q.sub.4 are each independently selected from the group consisting of hydrogen, a halogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, an alkylamido group having 1 to 20 carbon atoms, an arylamido group having 6 to 20 carbon atoms, and an alkylidene having 1 to 20 carbon atoms, R.sub.1 to R.sub.6 are each independently selected from the group consisting of hydrogen, a halogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms and a metalloid radical of a Group 14 metal substituted with a hydrocarbyl group having 1 to 20 carbon atoms; or at least two adjacent functional groups of R.sub.1 to R.sub.6 are connected to each other to form an aliphatic ring having 5 to 20 carbon atoms or an aromatic ring having 6 to 20 carbon atoms which is unsubstituted or substituted with at least one substituent selected from the group consisting of a halogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms and an aryl group having 6 to 20 carbon atoms, R.sub.7 to R.sub.11 are each independently selected from the group consisting of hydrogen, a halogen, an amino group, an alkyl amino group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, and a metalloid radical of a Group 14 metal substituted with a hydrocarbyl group having from 1 to 20 carbon atoms; or at least two adjacent functional groups of R.sub.7 to R.sub.11 are connected to each other to form an aliphatic ring having 5 to 20 carbon atoms or an aromatic ring having 6 to 20 carbon atoms which is unsubstituted or substituted with at least one substituent selected from the group consisting of a halogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms and an aryl group having 6 to 20 carbon atoms, R.sub.21 to R.sub.27 are each independently selected from the group consisting of hydrogen, a halogen, a silyl group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, and a metalloid radical of a Group 14 metal substituted with a hydrocarbyl group having from 1 to 20 carbon atoms, X.sub.1 to X.sub.3 are each independently selected from the group consisting of hydrogen, a halogen, a silyl group, an amino group, an alkyl amino group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms and an arylalkyl group having 7 to 20 carbon atoms; or at least two adjacent functional groups of X.sub.1 to X.sub.3 are connected to each other to form an aliphatic ring having 5 to 20 carbon atoms or an aromatic ring having 6 to 20 carbon atoms which is unsubstituted or substituted with at least one substituent selected from the group consisting of a halogen group, a silyl group, an amino group, an alkyl amino group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms and an aryl group having 6 to 20 carbon atoms, and Z is phosphorus (P), arsenic (As) or antimony (Sb).

12. The polypropylene-based resin composition according to claim 11, wherein the transition metal compound represented by Chemical Formula 1 is a compound represented by the following Chemical Formulas, or a mixture thereof: ##STR00011##

13. The polypropylene-based resin composition according to claim 11, wherein the transition metal compound represented by Chemical Formula 1 is a compound represented by the following Chemical Formula 3: ##STR00012## in Chemical Formula 3, M1, Q1, Q2, R1 to R9 are the same as defined in Chemical Formula 1, Cy is an aliphatic cyclic group having 4 or 5 carbon atoms including nitrogen (N), R, R12 and R13 are each independently selected from the group consisting of hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms and an arylalkyl group having 7 to 20 carbon atoms, and m is an integer of 0 to 2 when Cy is an aliphatic cyclic group having 4 carbon atoms, and it is an integer of 0 to 4 when Cy is an aliphatic ring having 5 carbon atoms.

14. The polypropylene-based resin composition according to claim 13, wherein the transition metal compound represented by Chemical Formula 3 is a compound represented by the following Chemical Formula 3a or Chemical Formula 3b: ##STR00013## in Chemical Formula 3a, Ra to Rd are each independently selected from the group consisting of hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, and an arylalkyl group having 7 to 20 carbon atoms, and M1, Q1, Q2, Ri to R9, R12 and R13 are the same as defined in Chemical Formula 3, ##STR00014## in Chemical Formula 3b, Re and Rf are each independently selected from the group consisting of hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, and an arylalkyl group having 7 to 20 carbon atoms, and M1, Q1, Q2, R1 to R9, R12 and R13 are the same as defined in Chemical Formula 3.

15. The polypropylene-based resin composition according to claim 13, wherein the transition metal compound represented by Chemical Formula 3 is at least one compound represented by a Chemical Formula selected from: ##STR00015##

16. The polypropylene-based resin composition according to claim 11, wherein the transition metal compound represented by Chemical Formula 2 is at least one compound represented by a Chemical Formula selected from: ##STR00016## wherein Cy denotes a cyclohexyl group, tBu denotes a t-butyl group, Me denotes a methyl group, and Ph denotes a phenyl group.

17. The polypropylene-based resin composition according to claim 11, wherein the catalyst composition comprises the transition metal compound represented by Chemical Formula 1 and the transition metal compound represented by Chemical Formula 2 in a weight ratio of 99:1. to 1:99.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows the results of the temperature rising elution fractionation (TREF) analysis of an olefin-based copolymer of Preparation Example 3.

(2) FIG. 2 shows the results of the gel permeation chromatography (GPC) analysis of an olefin-based copolymer of Preparation Example 3.

(3) FIG. 3 shows the results of the temperature rising elution fractionation (TREF) analysis of an olefin-based copolymer of Comparative Preparation Example 1.

EXAMPLES

(4) Hereinafter, preferred examples will be set forth for better understanding of the present invention. The following examples are merely illustrative of the present invention, and the scope of the present invention should not be construed to be limited thereby.

(5) In the following examples, organic reagents and solvents were purchased from Aldrich and Merck, and purified by a standard method. In all synthesis steps, the contact between air and moisture were blocked to enhance the reproducibility of experiments. In addition, in the following examples, the term overnight means a period of about 12 to 16 hours, and the term room temperature refers to a temperature of 20 to 25 C. The synthesis of all the transition metal compounds and the preparation of experiments were carried out using the dry box technique or glass tools maintained in dry condition under the dry nitrogen atmosphere. All the solvents used in the examples were of the HPLC level and dried before use.

Preparation Example 1

Preparation of 8-(1,2-dimethyl-1H-benzo[b]cyclopenta[d]thiophen-3-yl)-2-methyl-1,2,3,4-tetrahydroquinoline

(6) nBuLi (14.9 mmol, 1.1 eq) was slowly added dropwise in a solution of 2-methyl-1,2,3,4-tetrahydroquinoline (2 g, 13.6 mmol) dissolved in 10 mL of ether at 40 C. The temperature was slowly elevated to room temperature, and the mixture was stirred at room temperature for 4 hours. The temperature was lowered to 40 C., again and CO.sub.2(g) was injected. The reaction was maintained for 0.5 hours at a low temperature. The temperature was slowly elevated, and remaining CO.sub.2(g) was removed via a bubbler. THF (17.6 mmol, 1.4 ml) and tBuLi (10.4 mmol, 1.3 eq) were injected in the reaction mixture at 20 C., and then aged at a low temperature at 20 C. for 2 hours. The ketone (1.9 g, 8.8 mmol) was dissolved in diethyl ether solution and slowly added dropwise to the reaction mixture. After stirring at room temperature for 12 hours, 10 mL of water was injected and hydrochloric acid (2N, 60 mL) was added to the reactant, followed by stirring for 2 minutes. Organic solvents were extracted and the reactant was neutralized with a NaHCO.sub.3 aqueous solution. Then, the organic solvent was extracted and dried with MgSO.sub.4. Through silica gel column chromatography, a yellow oil (1.83 g, yield 60%) was obtained.

(7) 1H NMR (C6D6): 1.30 (s, 3H, CH3), 1.35 (s, 3H, CH3), 1.891.63 (m, 3H, Cp-H quinoline-CH2), 2.622.60 (m, 2H, quinoline-CH2), 2.612.59 (m, 2H, quinoline-NCH2), 2.702.57 (d, 2H, quinoline-NCH2), 3.153.07 (d, 2H, quinoline-NCH2), 3.92 (broad, 1H, NH), 6.796.76 (t, 1H, aromatic), 7.006.99 (m, 2H, aromatic), 7.307.23 (m, 2H, aromatic), 7.547.53 (m, 1H, aromatic), 7.627.60 (m, 1H, aromatic) ppm

Preparation of 8-(1,2-dimethyl-1H-benzo[b]cyclopenta[d]thiophen-3-yl)-2-methyl-1,2,3,4-tetrahydroquinoline-titanium Dichloride

(8) nBuLi (3.0 mmol, 2.1 eq) was slowly added dropwise to the ligand of 8-(1,2-dimethyl-1H-benzo[b]cyclopenta[d]thiophen-3-yl)-2-methyl-1,2,3,4-tetrahydroquinoline prepared above (1.0 g, 2.89 mmol) at 20 C. It was observed that a yellow slurry was formed, and the temperature was slowly elevated to room temperature, followed by stirring at room temperature for 12 hours. TiCl.sub.4DME (806 mg, 2.89 mmol, 1.0 eq) was added dropwise thereto, and then stirred at room temperature for 12 hours. After removal of the solvent, the reactant was extracted with toluene to obtain a red solid (700 mg, yield 52%).

(9) 1H NMR (C6D6): 1.461.467 (t, 2H, quinoline-NCH2), 1.85 (s, 3H, Cp-CH3), 1.79 (s, 3H, Cp-CH3), 2.39 (s, 3H, Cp-CH3), 2.37 (s, 3H, Cp-CH3), 2.102.07 (t, 2H, quinoline-NCH2), 5.225.20 (m, 1H, NCH), 5.265.24 (m, 1H, NCH), 6.896.87 (m, 2H, aromatic) 6.996.95 (m, 1H, aromatic), 7.197.08 (m, 2H, aromatic), 7.737.68 (m, 1H, aromatic) ppm

Preparation Example 2

(10) The compound (1.30 g, 2.37 mmol) represented by the following Chemical Formula i was dissolved in toluene (20 ml) and then MeMgBr (1.62 ml. 4.86 mmol, 2.05 eq.) was slowly added dropwise thereto at room temperature (23 C.). The mixture was then stirred at room temperature for 12 hours. It was confirmed by NMR that the starting material was disappeared, and the toluene solvent was filtered under reduced pressure, and the reaction mixture was dissolved in hexane (30 ml). The solid was then removed via filtration. The hexane solvent in the resulting solution was filtered under reduced pressure to obtain a transition metal compound of the following Chemical Formula ii.

(11) ##STR00009##

(12) <Preparation of Olefin-Based Copolymer>

Preparation Example 3

(13) In a 1.5 L autoclave continuous process reactor, a hexane solvent (4.67 kg/h) and 1-octene (1.55 kg/h) were added, and the temperature of the upper end of the reactor was pre-heated to 160 C. A triisobutylaluminum compound (0.03 mmol/min), a mixture of the transition metal compound prepared in Preparation Example 1 and the compound prepared in Preparation Example 2 (mixing ratio by weight=75:25, 0.75 mol/min), and dimethylanilinium tetrakis(pentafluorophenyl)borate cocatalyst (2.25 mol/min) was simultaneously introduced into the reactor. Then, ethylene (0.87 kg/h) was introduced in the autoclave reactor, and the reaction mixture was maintained under a pressure of 89 bar at 160 C. for 30 minutes, and then a copolymerization reaction was performed in a continuous process to produce an ethylene-1-octene copolymer as an olefin-based copolymer. Next, the remaining ethylene gas was withdrawn and the polymer solution was dried in a vacuum oven for 12 hours or more, and then the physical properties were measured.

Preparation Example 4

(14) An olefin-based polymer was prepared in the same manner as in Example 1, except 1-octene (1.51 kg/h), triisobutylaluminum compound (0.05 mmol/min), a mixture of the transition metal compound prepared in Preparation Example 1 and the compound prepared in Preparation Example 2 (mixing ratio by weight=75:25, 0.75 mol/min), and dimethylanilinium tetrakis(pentafluorophenyl)borate cocatalyst (2.25 mol/min) were used.

Preparation Example 5

(15) An olefin-based polymer was prepared in the same manner as in Example 1, except 1-octene (1.42 kg/h), triisobutylaluminum compound (0.03 mmol/min), a mixture of the transition metal compound prepared in Preparation Example 1 and the compound prepared in Preparation Example 2 (mixing ratio by weight=75:25, 0.675 mol/min), and dimethylanilinium tetrakis(pentafluorophenyl)borate cocatalyst (2.03 mol/min) were used.

Preparation Example 6

(16) An olefin-based polymer was prepared in the same manner as in Example 1, except 1-octene (1.30 kg/h), triisobutylaluminum compound (0.04 mmol/min), a mixture of the transition metal compound prepared in Preparation Example 1 and the compound prepared in Preparation Example 2 (mixing ratio by weight=75:25, 0.58 mol/min), and dimethylanilinium tetrakis(pentafluorophenyl)borate cocatalyst (1.40 mol/min) were used.

Comparative Preparation Example 1

(17) An ethylene-1-octene copolymer having a talc coating layer (product name: Eg8407) from Dow Co., which was prepared by using only one type of metallocene catalyst, was prepared.

Comparative Preparation Example 2

(18) An ethylene-1-octene copolymer (product name: LC670) from LG Chem. Ltd., which was prepared by using only one type of metallocene catalyst, was prepared.

Comparative Preparation Example 3

(19) An ethylene-1-octene copolymer (product name: Eg8200) from Dow Co., which was prepared by using only one type of metallocene catalyst, was prepared.

Comparative Preparation Example 4

(20) An ethylene-1-octene copolymer (product name: LC170) from LG Chem. Ltd., which was prepared by using only one type of metallocene catalyst, was prepared.

Experimental Example 1: Evaluation of Physical Properties of Olefin-Based Copolymer

(21) Various physical properties of the olefin-based copolymers prepared in Preparation Examples 3-6 and Comparative Preparation Examples 1-4 were measured and evaluated by the methods described below.

(22) (1) Density of a polymer (g/cc); measured according to ASTM D-792.

(23) (2) Melt index of a polymer (MI, g/10 min); measured according to ASTM D-1238 (condition E, 190 C., load of 2.16 kg).

(24) (3) Weight average molecular weight (Mw, g/mol) and molecular weight distribution (MWD); Each of a number average molecular weight (Mn) and a weight average molecular weight (Mw) was measured using gel permeation chromatography (GPC), and the weight average molecular weight was divided by the number average molecular weight to calculate molecular weight distribution (MWD).

(25) (4) TREF (Temperature rising elution fractionation)

(26) TREF was measured with a TREF equipment from Polymer Char using o-dichlorobenzene as a solvent in a range of 20 C. to 120 C. In detail, 40 mg of a polymer sample was dissolved in 20 ml of an o-dichlorobenzene solvent at 135 C. for 30 minutes and stabilized at 95 C. for 30 minutes. The resultant solution was introduced in a TREF column and cooled up to 20 C., at a cooling rate of 0.5 C./min, and the temperature was kept for 2 minutes. Then, the temperature was increased by heating from 20 C. to 120 C., at a heating rate of 1 C./min, and the concentration of an eluted polymer was measured while flowing the o-dichlorobenzene solvent in the column at the flowing rate of 0.5 mL/min.

(27) (5) Number of GPC peak: observed through gel permeation chromatography (GPC) analysis.

(28) The above-described physical property measurement and evaluation results are shown in Table 1 and FIGS. 1 to 3. FIGS. 1 and 2 shows the results of the temperature rise elution fractionation (TREF) analysis and gel permeation chromatography (GPC) analysis of the olefin-based copolymer prepared in Preparation Example 3, and FIG. 3 shows the results of the temperature rise elution fractionation (TREF) analysis of the olefin-based copolymer obtained in Comparative Preparation Example 1.

(29) TABLE-US-00001 TABLE 1 TREF Numben Number Te1( C.); Te2( C.); Te1( C.); of TREF of GPC Density Melt index fraction fraction fraction peak peak Unit g/cc g/10 min ratio (%) ratio (%) ratio (%) number number Preparation 0.867 24.5 6.7; 58 38.8; 22 87.6; 20 3 1 Example 3 Preparation 0.871 6.3 0.3; 45 41.0; 22 88.0; 33 3 1 Example 4 Preparation 0.869 10 0.5; 70 41.4; 18 89.0; 12 3 1 Example 5 Preparation 0.873 1.7 20.0; 44 30.1; 14 89.6; 42 3 1 Example 6 Comparative 0.871 27.9 33.2; 100 1 1 Preparation Example 1 Comparative 0.869 5.1 26.6; 100 1 1 Preparation Example 2 Comparative 0.873 4.9 34.8; 100 1 1 Preparation Example 3 Comparative 0.872 1.1 28.4; 100 1 1 Preparation Example 4

(30) Referring to Table 1 and FIGS. 1 to 3, the olefin-based copolymers of Preparation Examples 3 to 6 showed three peaks of Te1, Te2 and Te3 on TREF within a density range of 0.850 to 0.910 g/cc. In contrast, the polymers of Comparative Preparation Examples 1 to 4 showed only one peak within the same density range.

Examples 1 to 4 and Comparative Examples 1 to 4: Preparation of Polypropylene-Based Resin Composition

(31) 20 wt % of the polymers of Preparation Examples 3 to 6 and Comparative Preparation Examples 1 to 4 and 80 wt % of polypropylene (trade name: M1600, LG Chem. Ltd.) were mixed to prepare a polypropylene-based resin composition. More specifically, first, the above components were homogeneously mixed using a Henschel mixer to prepare the above composition. Such composition was pelletized with a co-rotating twin screw extruder and specimens for measuring physical properties were prepared using an injection machine.

Experimental Example 2: Evaluation of Physical Properties of Polypropylene-Based Resin Composition

(32) For the polypropylene-based resin composition specimens respectively prepared in Examples 1 to 4 and Comparative Examples 1 to 4, the flexural strength, flexural modulus, tensile strength, impact strength at low temperature and normal temperature, and shrinkage were measured by the following methods, and the results are summarized in Table 2 below.

(33) 1) Flexural strength and flexural modulus: measured according to ASTM D 790 standard using an INSTRON 3365 instrument.

(34) 2) Tensile strength: measured according to ASTM D 639 standard using an INSTRON 4465 instrument.

(35) 3) Normal-temperature Izod impact strength (IZOD, @ 23 C.): measured under the conditions of ASTM D 256, 1/4, 235 C.

(36) 4) Low-temperature Izod impact strength (IZOD, @ 30 C.): measured under the conditions of ASTM D 256, 1/4, 305 C.

(37) TABLE-US-00002 TABLE 2 Sample Comparative Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 4 Example 1 Example 2 Example 3 Example 4 Polymer Comparative Comparative Comparative Comparative Preparation Preparation Preparation Preparation Preparation Preparation Preparation Preparation Example 1 Example 2 Example 3 Example 4 Example 3 Example 4 Example 5 Example 6 Flexural 261 244 249 247 240 247 246 245 strength (kgf/cm.sup.2) Flexural 8684 8058 8077 8210 8055 8197 8190 8198 modulus (Secant 1%) (kgf/cm.sup.2) Tensile 194 183 186 183 181 187 186 181 strength (kgf/cm.sup.2) Low- 4.8 5.5 5.2 5.9 6.5 6.9 6.8 7.6 temperature impact strength (30 C.) (kgf .Math. m/m) Normal- 53.9 61.6 60.1 66.2 62.3 66.6 66.2 71 temperature impact strength (23 C.) (kgf .Math. m/m)

(38) Referring to Table 2 above, it was confirmed that the specimens of Examples 1 to 4 exhibited more improved impact strength while other physical properties were equal to or higher than those of the specimens of Comparative Examples 1 to 4.

(39) For reference, it was confirmed that the specimen of Comparative Example 1 in which a talc layer was treated on the commercial product itself, exhibited slightly higher flexural strength, flexural modulus, and tensile strength than those of Examples, but it was confirmed that in the absence of the talc layer as the reinforcing material, it showed the flexural strength, flexural modulus and tensile strength similar to those of the specimens of Examples, and that the specimen of Comparative Example 1 exhibited inferior impact strength as compared with Examples.