KR20060095158A - Polypropylene resin composition with high modulus characteristics - Google Patents

Abstract

The present invention relates to a polypropylene resin composition of high rigidity characteristics, comprising a high crystalline polypropylene resin, a rubber component, an inorganic filler and a polypropylene nano masterbatch, a polypropylene resin composition, The present invention relates to a polypropylene resin composition for interior and exterior parts of automobiles, which can be harmonized with excellent plastic parts.

Polypropylene Nano Masterbatch

Description

POLYPROPYLENE RESIN COMPOSITION WITH HIGH MODULUS CHARACTERISTICS}

The present invention relates to a polypropylene resin composition of high rigidity characteristics, comprising a high crystalline polypropylene resin, a rubber component, an inorganic filler and a polypropylene nano masterbatch, a polypropylene resin composition, The present invention relates to a polypropylene resin composition for interior and exterior parts of automobiles, which can be harmonized with excellent plastic parts.

The demand for plastic materials used as automotive parts in the automotive field is continuously increasing as weight reduction and high performance of materials are continuously achieved. In particular, among various plastic materials, polyolefins are rapidly increasing in demand compared to other plastic materials due to light weight due to low specific gravity, ease of recycling, and relatively low price. Among the polyolefin resins, polypropylene resins are not only used for automobile interior parts such as panels, door trims, console bodies, pillars, and trims, but also bumpers ( It is a material that can be applied to various applications such as exterior parts such as bumpers and side moldings.

However, since polypropylene resin has a limitation of the material that it is difficult to obtain a resin composition of harmonized properties with good flow characteristics and excellent rigidity and impact characteristics, it is possible to control various properties of the inorganic additives and the amount of rubber component added. The method of obtaining the resin composition which has is developed.

In order to solve the problem, the polyolefin resin including the reactive rubber phase, which not only maximizes rigidity by applying high crystalline polypropylene (High Isotactic Polypropylene) to the base resin, but also improves the content of ethylene-propylene rubber during propylene polymerization. (Reactor-made Thermoplastic Poly Olefin (RTPO)) has been developed a polypropylene resin composition for automotive interior parts to modify the impact characteristics while minimizing the separate rubber formulation. However, there is a problem that it is difficult to obtain a harmonized resin composition having good flow characteristics and good rigidity and impact characteristics due to the limitation of the material of polypropylene.

In order to solve the above problems, an object of the present invention is to provide an excellent polypropylene resin composition in which not only high impact characteristics but also stiffnesses are complemented to balance mechanical and impact characteristics.

The high stiffness polypropylene resin composition of the present invention is 20 to 91% by weight of the high crystalline polypropylene resin, 3 to 35% by weight of the rubber component, 5 to 25% by weight of the inorganic filler, and poly with respect to the total weight of the polypropylene resin composition. Propylene nano masterbatch characterized in that it comprises 1 to 20% by weight.

In the polypropylene resin composition of the present invention, as the highly crystalline polypropylene resin, a highly crystalline homopolypropylene resin having an isotactic pentad fraction of 96% or more by C ¹³ -NMR method, air of α-olefin and propylene Preference is given to highly crystalline polypropylene resins which are copolymers, polypropylene including reactive rubber phases or mixtures thereof. For example, a high crystalline homo polypropylene, a propylene-ethylene comonomer, a propylene-1-butene copolymer, a propylene-1-hexene copolymer or a propylene-4-methyl-1-pentene copolymer is mentioned. Here, when the said polypropylene resin is a copolymer of an alpha olefin and a propylene, ethylene is preferable as an alpha olefin. The content of the high crystalline polypropylene resin is preferably 20 to 91% by weight based on the total weight of the composition.

In the polypropylene resin composition of the present invention, the rubber component is one having at least one kind selected from the group consisting of an amorphous ethylene-α-olefin copolymer and a styrene-based thermoplastic elastomer, so as to have a suitable flexibility and rigidity balance in the composition. Do. In the amorphous ethylene-α-olefin copolymer, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, 4-methyl pentene-1, etc. may be mentioned as the α-olefin component. . Examples of the styrene-based thermoplastic elastomers include SEBS (styrene-ethylene-butadiene-styrene block copolymer), SEPS (styrene-ethylene-propylene-styrene block copolymer), SEP (styrene-ethylene-propylene block copolymer) and SBS ( Styrene-butadiene-styrene block copolymers). The content of the rubber component is preferably 3 to 35% by weight based on the total weight of the resin composition. If the content is less than 3% by weight, it is not preferable because the impact characteristics are inferior, and if it exceeds 35% by weight, the impact reinforcement is made, but the rigidity is insufficient to maintain the balance physical properties is not preferable.

In the polypropylene resin composition of the present invention, the inorganic filler is to have a suitable flexibility and rigidity balance in the composition, a group of glass fiber, talc, mica, calcium carbonate, wollastonite, barium sulfate, clay, magnesium sulfate and whisker It is preferable that it is at least 1 sort (s) chosen from, and talc is especially preferable. The inorganic fillers not only impart flexibility and rigidity to the composition, but also improve properties such as low temperature impact resistance. The content of the inorganic filler is preferably 5 to 25% by weight based on the total weight of the resin composition. If the content is less than 5% by weight, it is not preferable because the rigid complementary effect is inferior, and if it exceeds 25% by weight, it is not preferable to increase the weight.

In the polypropylene resin composition of the present invention, the polypropylene nano masterbatch effectively raises the flexural modulus of mechanical strength properties while minimizing the deterioration of the impact properties of the polypropylene resin composition of the present invention, thereby achieving a balanced physical property between stiffness and impact properties. For expression. The nano masterbatch is prepared by mixing the polypropylene resin, the nanomaterial, the graft monomer, and the peroxide so that the dispersion of the nanomaterial and the graft of the graft monomer occur simultaneously. That is, the preparation of the nano masterbatch may be performed in various ways under various conditions depending on the type and amount of polypropylene resin, the type and amount of nanomaterial, the type of monomer for graft, the amount of peroxide and the characteristics required for the nanocomposites to be manufactured. In particular, melt kneading in the temperature range of 180 ~ 230 ℃ is preferred. The mixing may be performed using a mixing equipment such as a K-kneader or a twin screw extruder.

The graft monomer used in the production of the polypropylene nanomaster batch is used to be grafted during some mixing of the polypropylene resin for the purpose of improving the dispersibility of the nanomaterial by modifying the hydrophilicity of the polypropylene resin. Therefore, any graft monomer generally used for grafting polypropylene resin can be used without particular limitation, and maleic acid is particularly preferable. The graft monomer may be used in various amounts depending on the type of monomer and the characteristics required for the nano-master batch to be prepared, and preferably 0.05 to 5 parts by weight based on 100 parts by weight of the polyolefin resin.

The peroxide used in the preparation of the polypropylene nano masterbatch is used as an initiator or a catalyst of a reaction for grafting a polypropylene resin into a monomer for grafting, and a peroxide generally used for grafting of a polypropylene resin. Can be used without any special limitation. The amount of the peroxide used may vary depending on the properties required for the nano-master batch to be produced, it is preferable that 0.05 to 5 parts by weight based on 100 parts by weight of the polyolefin resin.

Polypropylene nano masterbatch of the present invention can be used in various amounts according to the required properties, it is preferred that the polypropylene and nanoclay in the weight ratio 1: 0.05 ~ 1: 4, preferably 1: 0.25 ~ 1: 4 Do. The content of the polypropylene nano masterbatch is preferably 1 to 20% by weight based on the total weight of the resin composition. If the content is less than 1% by weight, it is not preferable because there is no rigid complementary effect. If the content is more than 20% by weight, it is not preferable because the economical and impact property deterioration is serious.

The polypropylene resin composition of the present invention may further include a colorant. Colorants which may additionally be added include, for example, aluminum flakes, aluminum powder, aluminum foil, zinc powder, bronze powder, pearl mica, titanium white, zinc oxide, zinc sulfide, chrome yellow, barium yellow, ultramarine blue, cobalt blue, Both inorganic pigments exemplified by cobalt green or carbon black and the like, or organic pigments exemplified by watching red, permanent red, palladium red, tallimal, benzidine yellow, or phthalocyanine green can be applied. The colorant may be added as it is or may be added in the form of a colorant masterbatch mixed with polypropylene in an appropriate ratio in advance, and the content thereof may be added to the entire resin composition in order to obtain a coloring effect without affecting the physical properties of the resin composition. 1-10 weight% is preferable with respect to weight.

In addition, additives known in the art may be additionally used in the polypropylene resin composition of the present invention. For example, long-term heat stabilizers, weather stabilizers, antistatic agents, lubricants, slip agents (SLIP agents), nucleating agents, flame retardants and the like can be added within a range not contrary to the object of the present invention.

Hereinafter, the present invention will be described in detail through examples. However, the following examples do not limit the content of the present invention.

EXAMPLE

Example 1

The ingredients shown in Table 1 were kneaded by kneading in a kneading extruder to prepare a resin composition. Next, in consideration of the weakening of the physical properties by water absorption, the prepared composition was dried for 3 hours in an 80 ℃ oven. The dry composition was prepared using a FCM-110 (molding force = 110 tons) injection machine manufactured by Samsung-Kluckner. The injection temperature was 180/200/200/200/200 ° C. in the order of the nozzle from the feeding hopper, and the injection pressure was formed at 60 to 100 bar. Physical properties of the prepared samples were measured after standing for 48 hours or more at room temperature.

According to ASTM standard, the measured specimens for physical properties were measured (melt index: measured at 230 ° C and 2.16kg based on ASTM D1238, density: ASTM D 1505, tensile strength and elongation:: 3.2mm thickness based on ASTM D638). Specimen measured at 50mm / min, flexural strength and flexural modulus: 3.2mm thick specimens, span 48mm, 4-speed 5mm / min based on ASTM D790, IZOD impact strength (-30 ° C): Notched Izod impact test using 3.2 mm thick specimen, notched type. Surface hardness: Rockwell hardness or shore A hardness measurement according to ASTM D785, Heat deflection temperature (HDT): HDT measuring instrument Measured the temperature at which deformation occurs at a load of 4.6kg), and the physical properties were evaluated, and the results are shown in Table 1.

Example 2

A specimen for measuring physical properties was prepared in the same manner as in Example 1, except that the contents of the highly crystalline polypropylene and polypropylene nano masterbatch were adjusted as shown in Table 1, and the physical properties were evaluated in the same manner as in Example 1. Was carried out. The results are shown in Table 1.

Example 3

Except that the content of high crystalline polypropylene and talc was adjusted as shown in Table 1, the specimen for measuring the physical properties was prepared in the same manner as in Example 1, and the physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 4

A specimen for measuring physical properties was prepared in the same manner as in Example 1, except that the contents of the highly crystalline polypropylene, talc, and polypropylene nano masterbatches were adjusted as shown in Table 1, and the physical properties were measured in the same manner as in Example 1. Evaluation was performed. The results are shown in Table 1.

Comparative Example 1

The content of the highly crystalline polypropylene was adjusted as shown in Table 1, except that the polypropylene nano masterbatch was prepared except that the test piece was prepared in the same manner as in Example 1, and the same method as in Example 1 The physical properties were evaluated. The results are shown in Table 1.

Table 1

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 PP-1 ¹⁾ (wt%) 15 10 20 20 20 RTPO-1 ²⁾ (wt%) 50 50 50 50 50 EXRB-1 ³⁾ (wt%) 10 10 10 10 10 Talc ⁴⁾ (wt%) 20 20 15 10 20 PP-Nano ⁵⁾ (wt%) 5 10 5 10 - Melt index g / 10min 13.5 15.0 16.4 18.2 12.3 density g / cm ³ 1.0390 1.0431 1.0320 1.0282 1.035 Tensile Strength (Yield) kg / cm ² 198 212 199 218 173 Tensile Strength (break) kg / cm ² 154 169 158 174 146 Elongation at Break % 315 302 305 299 325 Flexural strength kg / cm ² 315 335 321 354 294 Flexural modulus kg / cm ² 19,850 22,570 19,950 23,252 18,519 IZOD impact strength (-30 ℃) kgcm / cm 6.4 6.3 6.5 6.4 6.6 Surface hardness R-scale 42 49 44 52 33.7 Heat Deflection Temperature (4.6kg load) ℃ 121.2 124.6 122.1 125.8 119.7

1) PP-1: an ethylene-propylene copolymer having an ethylene content of 11.5% by weight, a hardness of 90, a Rockwell index of 90, a flow index of 30g / 10min, and an isotactic pentad fraction of 96% or more.

2) RTPO-1: Polypropylene containing a reactive rubber phase having an ethylene content of 23.0% by weight, a hardness of rockwell index 41 and a flow index of 8.8 g / 10 min.

3) EXRB-1 (E-8942): an ethylene-octene copolymer having a density of 0.857 g / cm ³ , an octene content of 45% by weight, a hardness (Shore A) of 50, and a flow index of 1.0 g / 10 min.

4) Talc: Talc which selects only those having a particle size in the range of 3 ~ 5㎛.

5) PP-Nano: A masterbatch containing polypropylene and nanoclay in a ratio of 1: 0.67, with tensile strength of 428kgf / cm ² , flexural modulus of 24,930kgf / cm ² , and IZOD impact strength of 4.1kgfcm / cm. Masterbatch.

Comparative Example 1 is an example of a polypropylene resin composition generally used for automotive interior materials. As shown in Table 1, the polypropylene resin composition (Examples 1 to 4) including the polypropylene nano masterbatch according to the present invention has a basic mechanical stiffness such as tensile strength, flexural strength and flexural modulus as compared to Comparative Example 1. It became high and the impact characteristic became low, and the tendency which harmonized rigidity and impact characteristic was acquired. In particular, when comparing Examples 3 and 4, as the amount of the polypropylene nano masterbatch increases, the surface hardness increases, and the heat distortion temperature, which is a heat-resistant property, also increases, but the specific gravity is lowered. Therefore, it can be seen that a lightweight product having a reduced specific gravity can be obtained while increasing mechanical properties.

Example 5

The ingredients shown in Table 2 were kneaded by kneading in a kneading extruder to prepare a resin composition. Next, in consideration of the weakening of the physical properties by water absorption, the prepared composition was dried for 3 hours in an 80 ℃ oven. The dry composition was prepared using a FCM-110 (molding force = 110 tons) injection machine manufactured by Samsung-Kluckner. The injection temperature was 180/200/200/200/200 ° C. in the order of the nozzle from the feeding hopper, and the injection pressure was formed at 60 to 100 bar. Physical properties of the prepared samples were measured after standing for 48 hours or more at room temperature.

The prepared specimens were evaluated for physical properties in the same manner as in Example 1. The results are shown in Table 2.

Example 6

Specimens were prepared in the same manner as in Example 5, except that the content of talc and polypropylene nano masterbatches was adjusted as shown in Table 2, and the physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 7

Except that the content of high crystalline polypropylene and talc as shown in Table 2 was prepared in the same manner as in Example 5, and the physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 8

Specimens were prepared in the same manner as in Example 5 except that the contents of the highly crystalline polypropylene, talc and polypropylene nano masterbatches were adjusted as shown in Table 2, and the physical properties were evaluated in the same manner as in Example 1. It was. The results are shown in Table 2.

Comparative Example 2

The content of the highly crystalline polypropylene is adjusted as shown in Table 2, except that the polypropylene nano masterbatch is not included, the specimen is prepared in the same manner as in Example 5, and the physical properties are evaluated in the same manner as in Example 1. It was. The results are shown in Table 2.

[Table 2]

division Example 5 Example 6 Example 7 Example 8 Comparative Example 2 PP-2 ⁶⁾ (wt%) 20 20 20 15 20 PP-3 ⁷⁾ (wt%) 33 33 38 38 38 EXRB-2 (wt%) 26 26 26 26 26 Talc (% by weight) 16 11 11 11 16 PP-Nano (% by weight) 5 10 5 10 - Melt index g / 10min 32.1 34.5 33.2 35.4 31 density g / cm ³ 0.9978 0.9991 0.9652 0.9785 0.9962 Tensile Strength (Yield) kg / cm ² 185 198 205 224 178 Tensile Strength (break) kg / cm ² 149 165 182 192 132 Elongation at Break % 405 401 389 395 410 Flexural strength kg / cm ² 298 315 332 348 277 Flexural modulus kg / cm ² 16,521 17,592 19,215 20,154 15,050 IZOD impact strength (23 ℃) kgcm / cm 45.3 42.3 40.2 36.5 46.9 IZOD impact strength (-30 ℃) kgcm / cm 6.4 6.2 6 5.8 6.5 Surface hardness R-scale 25.9 29.5 35.6 38.9 22.4 Heat Deflection Temperature (4.6kg load) ℃ 116.2 119.6 123.1 125.4 114.4

6) PP-2: an ethylene-propylene copolymer having an ethylene content of 11.5% by weight, a hardness of Rockwell index 84, a flow index of 45g / 10min, and an isotactic pentad fraction of 96% or more.

7) PP-3: Ethylene-propylene copolymer having an ethylene content of 11.0% by weight, a hardness of 87, a Rockwell index of 87, a flow index of 60g / 10min, and an isotactic pentad fraction of 96% or more.

8) EXRB-2 (E-8130): an ethylene-octene copolymer having a density of 0.864 g / cm ³ , an octene content of 42% by weight, a hardness (Shore A) of 60, and a flow index of 13 g / 10 min.

Comparative Example 2 is an example of a polypropylene resin composition generally used for automotive exterior materials such as bumpers. As shown in Table 2, in the polypropylene resin composition (Examples 5 to 8) to which the polypropylene nanomaster batch was added according to the present invention, the mechanical properties (tensile strength, Flexural strength, flexural modulus, and hardness) were improved. That is, in the polypropylene resin composition including the polypropylene nano masterbatch as in the present invention, when the rubber content is constant, the performance difference of the impact strength characteristics is insignificant, but it can be seen that the mechanical strength can be improved by 15% or more as a whole. .

The present invention provides an excellent polypropylene resin composition in which not only high impact characteristics but also rigidity are complemented to balance mechanical and impact characteristics.

Claims (6)

20-91% by weight of highly crystalline polypropylene resin having an isotactic pentad fraction of 96% or more by C ¹³ -NMR method, 3-35% by weight of rubber component, 5-25% by weight of inorganic filler and polypropylene nano masterbatch 1 Polypropylene resin composition comprising ~ 20% by weight. The polypropylene resin according to claim 1, wherein the high crystalline polypropylene resin is a high crystalline homo polypropylene resin, a copolymer of? -Olefin and propylene, a polypropylene including a reactive rubber phase, or a mixture thereof. Composition. The polypropylene resin composition according to claim 1, wherein the rubber component is at least one selected from the group consisting of amorphous ethylene-α-olefin copolymers and styrene-based thermoplastic elastomers. The polypropylene resin composition according to claim 1, wherein the inorganic filler is talc. The polypropylene resin composition according to claim 1, wherein the polypropylene nano masterbatch is manufactured by mixing polypropylene and nanoclay in a weight ratio of 1: 0.05 to 1: 4. The polypropylene resin composition according to claim 1, further comprising 1 to 10% by weight of a colorant masterbatch.