KR20030026675A - A polypropylene resin composition reinforced with a long glass fiber - Google Patents

Abstract

PURPOSE: Provided is a long fiber reinforced polypropylene resin composition excellent in stiffness, chemical-resistance, heat-resistance, and impact-resistance, which can be applied to the interior and exterior material of cars like instrument panels. CONSTITUTION: The long fiber reinforced polypropylene resin composition contains: 30-70wt% of a propylene polymer comprising 0-30wt% of a propylene homopolymer and 70-100wt% of a propylene-ethylene copolymer, wherein the propylene homopolymer has a pentad fraction(%mmm) of more than 96% measured by 13C-NMR and an intrinsic viscosity of 0.7-2.5dl/g and the propylene-ethylene copolymer has an intrinsic viscosity of 3.0-6.0dl/g and the ethylene content of 3-20wt%; 10-30wt% of an ethylene-alpha-olefin copolymer rubber comprising 60-95wt% of an ethylene-propylene copolymer rubber and 5-40wt% of an ethylene-alpha-olefin copolymer; 10-50wt% of long glass fiber using E-glass chop strands with 8-16mm.

Description

A polypropylene resin composition reinforced with a long glass fiber}

The present invention relates to a long-fiber-reinforced polypropylene resin composition for automotive interior and exterior trim, more specifically (A) propylene homopolymer having a pentad fraction (% mmmm) or more than a certain level, or propylene having a specific range of extreme viscosity- Propylene polymers composed of ethylene copolymers or mixtures thereof; (B) an ethylene-α-olefin copolymer rubber in which an ethylene-propylene copolymer rubber and an ethylene-α-olefin copolymer are mixed; (C) The present invention relates to a thermoplastic long fiber reinforced polypropylene resin composition containing long glass fiber and other additives as a reinforcing agent.

Conventionally, in order to use plastics as interior materials of automobiles, basic conditions such as impact resistance, chemical resistance, and moldability must be satisfied. Thus, a mixture of polycarbonate and acrylonitrile-butadiene-styrene copolymer (ABS) or the acrylonitrile-butadiene-styrene copolymer containing the above physical properties of the engineering plastic (EP) material Has been used.

However, the resin is excellent in physical properties, but very expensive and has a disadvantage that the chemical resistance and recycleability is inferior to polyolefin-based resin, in particular propylene-based resin is gradually replaced by a polypropylene resin composition.

Recently, polyethylene and polypropylene, which are polyolefin resins, have superior moldability, impact resistance, chemical resistance, etc., and have low specific gravity and low cost, compared to conventional polypropylene resins, and thus, interior materials, such as automobile bumpers, and various fillers. It is widely used for the purpose. However, these also had a problem that the structural reinforcement such as increased thickness, rib reinforcement, etc. must be made because the rigidity and heat resistance are inferior to the existing engineering plastic materials, and there is a need for improvement.

Accordingly, the inventors of the present invention have made intensive efforts to solve the above problems, and as a result, ethylene? -Olefin copolymers and feldspar containing ethylene propylene copolymer rubber in propylene homopolymer or propylene ethylene block copolymer alone or in a mixture thereof It can prescribe fiber and other additives such as heat stabilizers, anti-aging agents, lubricants, and black pigments to enhance the strength and heat resistance of the existing engineering plastics, as well as to improve the chemical resistance of the existing polyolefin resins. The present invention was completed by confirming that the physical properties can be improved.

After all, the main object of the present invention

(A) 30 to 70% by weight of propylene polymer consisting of 0 to 30% by weight of propylene homopolymer and 70 to 100% by weight of propylene-ethylene copolymer;

(B) 10 to 30% by weight of ethylene-α-olefin copolymer rubber composed of 60 to 95% by weight of ethylene-propylene copolymer rubber and 5 to 40% by weight of ethylene-α-olefin copolymer;

(C) Long-fiber polypropylene resin, characterized in that it comprises 10 to 50% by weight of long glass fibers composed of 10 to 50% by weight using chop strands of 8 to 16 mm E-glass. It is to provide a composition.

The present invention provides a composition comprising: (A) 30 to 70% by weight of a propylene polymer composed of 0 to 30% by weight of a propylene homopolymer and 70 to 100% by weight of a propylene-ethylene copolymer;

(B) 10 to 30% by weight of ethylene-α-olefin copolymer rubber composed of 60 to 95% by weight of ethylene-propylene copolymer rubber and 5 to 40% by weight of ethylene-α-olefin copolymer;

(C) Features a long fiber polypropylene resin composition comprising 10 to 50% by weight of long glass fibers composed of 10 to 50% by weight using chop strands of 8 to 16 mm E-glass. It is done.

When the long fiber reinforced polypropylene resin composition thus prepared is injection molded, an automobile interior molded article suitable for an instrument panel can be obtained. In addition, when the molded article is mounted on a vehicle, an instrument panel having excellent physical properties can be manufactured.

The components and properties of the long fiber-reinforced polypropylene resin composition of the present invention will be described in more detail as follows.

(A) propylene polymer

The propylene polymer is a crystalline polymer composed of a propylene homopolymer having a propylene monomer as a main component and a propylene-ethylene copolymer containing ethylene, and is used alone or in combination with a propylene homopolymer.

The propylene homopolymer has a pentad fraction (% mmmm) measured by 13 C-NMR is 96% or more, preferably 96.5% or more, more preferably 97% or more. At this time, if the% mmmm fraction is less than 96%, the stiffness, heat resistance, and the like falls. Further, the propylene polymer has an intrinsic viscosity [?] Measured in 135 ° C decalin of 0.7 to 2.5 dl / g, preferably 0.85 to 2.2 dl / g, more preferably 0.9 to 2.0 dl / g. If the intrinsic viscosity is less than 0.7 dl / g, the impact strength drops, and if it exceeds 2.5 dl / g, the moldability is lowered.

As the propylene-ethylene copolymer, an intrinsic viscosity [η] of the xylene extract in 135 ° C decalin is used in the range of 3.0 to 6.0 dL / g. If the intrinsic viscosity is less than 3.0 dl / g, the impact strength is lowered. More preferred intrinsic viscosity is at least 3.5 dl / g, in particular at least 4.0 dl / g. In addition, the content of ethylene is 3 to 20% by weight, preferably 5 to 15% by weight.

In addition, the mixing ratio of the propylene homopolymer and the propylene-ethylene copolymer is preferably 0 to 30: 100 to 70% by weight, more preferably 0 to 20: 100 to 80% by weight in view of impact strength and fluid balance. The propylene homopolymer lacks impact resistance, and the propylene-ethylene copolymer lacks moldability, rigidity, heat resistance, and the like, so that the two components can be mixed and used complementarily.

The blending ratio of such propylene polymer (A) is 30 to 70% by weight, preferably 45 to 65% by weight based on the total resin composition. At this time, when the content exceeds 70% by weight, the impact strength is lowered, when the content is less than 30% by weight, the moldability is lowered.

(B) ethylene-α-olefin copolymer rubber

The ethylene-α-olefin copolymer rubber is composed of an ethylene-propylene copolymer rubber and an ethylene-α-olefin copolymer, and is added to increase the impact resistance by imparting elasticity to the entire polypropylene resin composition.

The ethylene-propylene copolymer rubber (EPR) has a Mooney viscosity (125 ° C) of 50 to 80 dl / g, preferably 55 to 70 dl / g. If the Mooney viscosity exceeds 80 dl / g, it will cause dispersion defects, as well as poor appearance and mechanical properties, and if it is less than 50 dl / g, impact resistance will be lowered. Ethylene-propylene copolymer rubber has a propylene content of 20 to 80% by weight, preferably 40 to 80% by weight, but when the propylene content is less than 20% by weight, the impact strength is lowered. Degrades.

In addition, the ethylene-α-olefin copolymer is mainly ethylene butene-1 copolymer (EBM) or ethylene octene-1 copolymer (EOM) is used, the α-olefin content of 12 to 45% by weight is used. In the case of the EBM, butene (C4) content is 12 to 25% by weight, preferably 15 to 20% by weight, and the melt index (MI) is 0.5 to 10 g / 10min, preferably 1 to 5 g / 10min. Use it. In the case of the EOM, the octene (C8) content is 15 to 45% by weight, preferably 25 to 35% by weight, and the Mooney viscosity [η] ML 1 + 4 (121 ° C) is 1 to 50 dl / g, Preferably it is 1.5-35 dl / g, the density is 0.86-0.91 g / cm <3>, Preferably the thing which is 0.87-0.90 g / cm <3> is used.

In addition, the mixing ratio of the ethylene-propylene copolymer rubber (EPR) and the ethylene-α-olefin copolymer is 60 to 95:40 to 5% by weight, more preferably 80 to 95:20 to 15% by weight. Effective in terms of rigid balance. That is, when there is no ethylene-α-olefin copolymer, the rigidity is inferior, and when the ethylene propylene copolymer rubber (EPR) is less than 60% by weight, the impact resistance is inferior.

The blending ratio of such ethylene-α-olefin copolymer rubber is 10 to 30% by weight, preferably 15 to 25% by weight based on the total resin composition. At this time, when the content is more than 30% by weight, the rigidity and moldability are lowered, and when the content is less than 10% by weight, the impact strength is lowered.

(C) long glass fiber

Glass fiber is this glass (E GLASS), ISI glass (ECRGLASS) which improved corrosion resistance, high strength S, S-2, R, tea glass (S, S-2, R, T GLASS), acid-resistant seed, CA GLASS, etc. are used, and E-GLASS is especially preferable from a commercial point of view. A chop strand of 8 to 16 mm is used, but when the length of the fiber is less than 8 mm, impact resistance is lowered, and when it exceeds 16 mm, moldability is lowered. Such long glass fibers are contained in the range of 10 to 50% by weight based on the total resin composition, but when the content is less than 10% by weight, the rigidity and heat resistance are lowered, and when the amount exceeds 50% by weight, the moldability is lowered.

Additives which may be added in the present invention are conventional and are, for example, antioxidants, neutralizing agents, coupling agents, antistatic agents, and the like, which are contained within an appropriate content range. Here, as an antioxidant, a phenolic antioxidant, a phosphite antioxidant, a thiodipropionate synergy, etc. may be used, and as a neutralizing agent, calcium stearate, zinc oxide, etc. may be used, and a coupling agent may be used, such as maleic acid. A polymer having a reactive functional group may be used, and these or other additives may be easily used by those skilled in the art.

The melt index (MI) of the composition finally prepared with such ingredients and compositions is preferably 3 to 20 g / 10 min. If the MI is less than 3 g / 10 min, the decrease in productivity and the flow mark on the final product May occur, and when MI exceeds 20 g / 10min, it is difficult to obtain desired physical properties in terms of stiffness and impact strength.

The manufacturing method of the long fiber reinforced polypropylene resin composition of this invention mix | blended with the above components is not limited to a specific thing. For example, the long fiber-reinforced polypropylene resin composition of the present invention is prepared by mixing the components (A) and (B) by a conventional mechanical kneading method and by preheating the component (C) to (A) and (B). Coating by impregnation method to make interfacial bonding between the mixture of component) and the component (C), and the mixture of components (A), (B) and (C) obtained here is cooled and solidified by a bushing nozzle and Prepare pellets. Specifically, for example, the mixing of the components (A) and (B) may employ a method using a general melt kneading machine such as a short-variety mixer, a single screw extruder, a twin screw extruder, and a multi-wheel screw extruder. In addition, it is preferable to perform kneading temperature at 180-240 degreeC. The individual glass fibers constituting the fiber bundle (component (C)) by impregnating the fiber bundle (component (C)) preheated by the pretreatment and then released from the above mixture and the roving type fiberglass cake. The resin of the present invention is controlled by cutting the various glass fiber contents such as 30%, 40%, 40% through the bushing nozzle located at the end of the molding facility, cooling and solidifying the filaments, and cutting them into pellets of any shape by a cutter. Get

In the case of the molding process for the composition of the present invention, extrusion molding, blow molding, injection molding, sheet molding, etc. are all possible, but not particularly limited, injection molding is most suitable.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by Examples.

Examples and Comparative Examples

First, components (A), (B) and (C) are prepared as shown in the following Tables 1 to 3 to prepare a long fiber reinforced polypropylene resin composition, and then each component is prepared at a composition ratio as shown in Table 4 below. Blended. At this time, the (A) and (B) components were mixed and prepared by a conventional mechanical kneading method, and the (C) component was preheated to form an interfacial bond between the mixture of the (A) and (B) components and the (C) component. It was coated by the impregnation method in order to cut the mixture of the components (A), (B), (C) obtained here to prepare pellets for the resin composition of 3 to 5 mm in diameter, 12 mm in length.

(A) propylene polymer

Table 1 below shows the properties of the propylene polymer components used in the experiments.

In this case, the propylene homopolymer used had a fraction of 96.8% mmmm as measured by 13 C NMR for the isotactic pentad fraction of propylene monomers connected in series in the propylene unit. In addition, when measuring intrinsic viscosity, the propylene homopolymer and the propylene-ethylene copolymer were completely dissolved in decalin at 135 ° C., and the viscosity of the solution was measured using an Ubbeholde viscometer.

(B) Ethylene-propylene copolymer rubber

Table 2 shows the characteristics of the ethylene-propylene copolymer rubber and the ethylene-α-olefin copolymer used in the experiment.

(C) long glass fiber

Table 3 shows the characteristics of the long glass fibers used in the experiment.

Experimental Example: Physical property test of pellets formed from long fiber reinforced polypropylene resin composition

Pellets of the respective compositions prepared in the above Examples and Comparative Examples were prepared for the measurement of physical properties using an injection molding machine set to 220 ℃.

Then, the tensile strength, impact strength, flexural strength, scratch resistance, heat deformation tests were performed in accordance with the following test methods to investigate the properties and workability of the test pieces.

(1) Melt index (MFR)

: Melt index according to ASTM D1238 was measured at a load of 230 ℃, 10 kgf.

(2) Izod impact strength

: Measured at room temperature (23 ° C) and low temperature (-10 ° C) according to ASTM D256.

(3) flexural modulus

: Measured according to ASTM D790.

(4) Rockwell hardness

: Measured according to ASTM D 785.

(5) Heat Distortion Temperature

: Measured according to ASTM D 648.

From the results shown in Table 5, it can be seen that any of the resin compositions of Examples 1 to 4 can obtain molded articles having impact resistance, rigidity and heat resistance. On the other hand, when using a low-viscosity ethylene-propylene rubber alone as in Comparative Example 1, the impact resistance is low, safety problems, in Comparative Example 2 in the case of short fibers short glass fiber flexural modulus , Heat deflection temperature, and Rockwell hardness are lowered. In particular, there is a sharp decrease in impact strength. In the case of the comparative example 3, the propylene ethylene copolymer component with high flowability is used too much, and a physical property fall, especially an impact resistance is bad. In Comparative Example 4, when the propylene ethylene copolymer having high flowability and short fibers are simultaneously applied, the impact strength is very low.

As described above, the present invention relates to a long-fiber polypropylene resin composition, the resin according to the present invention is excellent in stiffness, chemical resistance, heat resistance and the like than conventional, particularly excellent impact resistance instrument panel and the like It can be applied to a wide range of automotive interior and exterior materials.

Claims (5)

(A) 30 to 70% by weight of propylene polymer consisting of 0 to 30% by weight of propylene homopolymer and 70 to 100% by weight of propylene-ethylene copolymer; (B) 10 to 30% by weight of ethylene-α-olefin copolymer rubber composed of 60 to 95% by weight of ethylene-propylene copolymer rubber and 5 to 40% by weight of ethylene-α-olefin copolymer; (C) A long fiber polypropylene resin composition comprising 10 to 50% by weight of long glass fibers composed of 10 to 50% by weight of chop strands having 8 to 16 mm of E-glass. The propylene homopolymer of claim 1, wherein the propylene homopolymer has a pentad fraction (% mmmm) measured by 13 C-NMR of 96% or more and an intrinsic viscosity of 0.7 to 2.5 dl / g; The propylene-ethylene copolymer has an intrinsic viscosity of 3.0 to 6.0 dl / g, the content of ethylene is 3 to 20% by weight of a long fiber polypropylene resin composition. According to claim 1, wherein the ethylene-propylene copolymer rubber (EPR) has a Mooney viscosity (125 ℃) of 50 to 80 dl / g, the propylene content of the ethylene-propylene copolymer rubber 20 to 80% by weight Long fiber polypropylene resin composition. The long fiber polypropylene resin composition according to claim 1, wherein the ethylene-α-olefin copolymer has an α-olefin content of 12 to 45% by weight and a melt index (MI) of 0.5 to 10 g / 10min. An automotive interior molded article wherein the long fiber polypropylene resin composition of claim 1 is injection, extrusion, or press molding.