KR20130032101A - Reused complexed polypropylene of light weight and strength for use car interior and exterior materials - Google Patents

Abstract

PURPOSE: A composite polypropylene for car interior and exterior materials is provided to improve dimensional stability, processability, and moldability while maintaining the uniformity of products. CONSTITUTION: A composite polypropylene for car interior and exterior materials comprises 50-90 weight% recycled polypropylene, 5-20 weight% talc, 10-30 weight% glass fiber, 1-20 weight% glass bubble semi-product, and 5-20 weight% rubber. The ratio of recycled polypropylene : glass fiber : glass bubble semi-product is 15 : 25 : 3-5 : 1. The melt index of the recycled polypropylene is 18 g/10 minutes or more, the tensile strength is 180 kgf/cm^2 or more, the elongation is 110 % or more, and the specific gravity is 0.99 or less.

Description

Lightweight Rigidity Recycling Composite Polypropylene for Automobile Interior and Exterior Materials TECHNICAL FIELD

The present invention relates to a composite polypropylene material for use as an interior exterior material of an automobile, and more particularly, to a recycled composite polypropylene composition having the required rigidity while reducing weight.

The automotive industry, like other industries, is developing into an eco-friendly industry.As a result, the issues of fuel efficiency improvement and energy consumption reduction in the manufacturing process are concentrated on the light weight of materials, especially glass bubble and glass fiber. Light weight has been spreading to parts of the body such as TRUNK or HOOD using lightweight and high rigidity materials using glass fiber and carbon fiber. In addition, the quality and quality of plastics have been increased and quality has been improved by restricting the amount of environmentally harmful substances on heavy metals such as cadmium (Cd), lead (Pb), mercury (Hg), hexavalent chromium (Cr + 6) and recycling regulations. This is required.

Metals such as iron and aluminum, which are frequently used in automobiles, are being replaced by synthetic resins in many parts, and research on lightweighting by replacing existing thermosetting synthetic resins with olefin-based low-weight plastic materials is ongoing. In particular, polyolefins are rapidly increasing in demand compared to other plastic materials due to light weight, ease of recycling, and relatively low price.However, since engine room parts are parts that are directly exposed to high heat or indirectly exposed, they can be used in addition to stiffness and durability. I need it. Conventionally, the air conditioning and engine room parts of automobiles have used a nylon reinforced resin composition having excellent heat resistance, but to achieve light weight and cost reduction, polyolefin reinforced resin compositions such as polypropylene are used, and various proposals have been proposed. The heat deflection temperature of polypropylene itself is about 110 ~ 120 ℃, so polypropylene alone cannot be used, so it is compounded with inorganic fillers such as talc, glass fiber and mica.

However, the polypropylene composite resin compounded with the inorganic filler is improved in heat resistance and rigidity as the content of the filler is increased. However, the weight of the inorganic filler is increased and the weight and hardness and impact strength are reduced.

In addition, the hard-type instrument panel of the instrument panel, which is a representative part of automobile interior materials, is injection-molded a material called PPF (a material in which an inorganic filler such as rubber and talc is compounded in PP). The foam type instrument panel is used by injecting PC + ABS blend material, which is an engineering plastic, as the core material, but the core material for foam is recently using PPF material in terms of material integration, cost reduction, and light weight. Although the applied products are increasing, the weight reduction effect due to the use of talc is insignificant, but problems such as lowering of resin flowability, lowering of dimensional stability, and increased foam molding defects are occurring.

In Patent Document 1 (Japanese Patent Laid-Open No. Hei 9-165477) and Patent Document 2 (Japanese Patent Laid-Open No. Hei 9-165478), 50 to 95% by weight of crystalline polypropylene resin and 5 to 60% by weight of inorganic filler ( Talc) and up to 30% by weight of ethylene-propylene rubber and other additives are proposed to process polypropylene composite resin for automotive functional parts. However, the above-described conventional technology has a problem that the weight is increased due to the high content of talc due to the use of polypropylene resin having low heat resistance, rigidity, and impact strength, and the price is high and the rigidity is poor due to the use of talc and rubber. .

According to Patent Document 3 (Korea Patent Registration No. 10-0683229) according to the polypropylene composite material composition to improve the mechanical properties such as tensile strength, flexural modulus, etc. by improving the compatibility (compatibility) between polypropylene and glass bubble polypropylene 50-80 Polypropylene composite comprising weight%, talc 6-30% by weight, rubber 10-30% by weight, glass bubble 3-15% by weight and 0.5-7% by weight of the binder represented by the following formula (1) The average particle size of the glass bubble used as the material composition is 14-18 μm, and the average molecular weight of the compound represented by Formula 1 is 100-5,000, but the glass bubble having the particle size of 14-18 μm has a particle size of It is not practical considering the large and low specific gravity and the dispersibility, and the price is also 3 ~ 4 times of synthetic resin.

In addition, according to Patent Document 4 (Korean Patent Registration No. 10-0399834), the isotactic peptide by the C-NMR method isotactic polypropylene, or propylene-ethylene copolymer, propylene-1-butene copolymer, propylene-1- Copolymers of propylene or other alpha olefins such as hexene copolymers, propylene-4-methyl-1-pentene copolymers, or mixtures thereof, having a melt index of 10 to 50 g / 10 minutes (ASTM D1238, 230 ° C.) The nanostructured compound having a content of 69 to 90% by weight and having methyl, phenyl, phenethyl, isooctyl, cyclohexyl, cyclophenyl and isobutyl units for improving heat resistance is in the form of a white powder or a yellow liquid, Average particle size is 10 ~ 20 10, contains 1 ~ 15% by weight of weight average molecular weight (Mw) 800 ~ 1200, and 5 ~ 20% by weight of talc having 1 ~ 5㎛. In addition, modified polypropylene resin or modified polyolefin copolymer rubber contains 1 to 10% by weight, which increases the heat resistance and increases the rigidity and impact strength while reducing the content of the inorganic filler, but the nano structure compound and the graft modification corresponding to 1 to 15% The price of olefin copolymer rubber is very high and the heat resistance temperature is not as high as expected.

JP 09-165477 A (1997-06-24) JP 09-165478 A (1997-06-24) KR 10-0683229 B1 (2007-02-08) KR 10-0399834 B1 (2003-09-18)

It is an object of the present invention to mix a glass bubble semifinished product which is not compatible with recycled polypropylene, which has not been commercialized so far, with inorganic materials having a low specific gravity, and to impart interfacial properties, for example, to recycle light and high rigidity that can be used as interior and exterior materials of automobiles. To provide a composite polypropylene.

Recyclable composite polypropylene according to the present invention to achieve the above object is made of a composition of polypropylene, talc, glass fiber, glass bubble semi-finished product and rubber.

Preferably the ratio of recycled polypropylene: glass fiber: glass bubble semifinished product is 15-25: 3-5: 1.

The recycled composite polypropylene according to the present invention uses an inexpensive glass bubble semi-finished product in recycled polypropylene, and thus is more than 1/2 cheaper than using the glass bubble, and has excellent dispersibility, thereby maintaining uniformity of the product. Even in the case of large parts, shrinkage is less likely to occur, resulting in improved dimensional stability, deformation after molding, and improved workability and formability.

This is fundamentally different from using glass bubbles. In addition, the conventional glass bubble is more than three times more expensive than semi-finished products, the particle size is larger and the specific gravity is lower than that of the resin, so the dispersibility is low. When the glass bubble is densified, the compressive strength decreases sharply. In this complex case, shrinkage due to the breakdown of the glass bubble appears. On the other hand, when using the glass bubble semi-finished product, the specific gravity is larger than glass bubble but the apparent specific gravity is 1 or less, and the size is very small (less than 5㎛). Shrinkage does not occur as with glass bubbles.

For the practice of the present invention, 50 to 90% by weight of recycled polypropylene, 5 to 20% by weight of talc, 10 to 30% by weight of glass fibers, 1 to 20% by weight of semi-finished glass bubbles, 5 to 30% by weight of rubber, trace amounts of heat A lightweight rigid recycled composite polypropylene composition was prepared comprising a stabilizer and an antioxidant.

Recycled polypropylene is used to crush waste bumper to separate coating film, wash and dry the crude product by adding fluidizing agent, rubber, etc., or mixing 10 ~ 50% by weight of polypropylene generated from domestic waste or newly produced 10 ~ 50% by weight of mixed polypropylene extruded, the melt index 18g / 10 minutes or more, tensile strength 180kgf / ㎠ or more, elongation 110% or more, flexural strength 240kgf / ㎠ or more, flexural modulus 12,000kgf / ㎠ or more specific gravity 0.99 or less It is desirable to be satisfied. In addition, the rubber is preferably a polyolefin elastomer and it is preferable to use non-halogen-based heat stabilizers and antioxidants.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments of the present invention.

The composite polypropylene containing the glass-finished bar (G / F) and the semi-finished glass bubble in recycled polypropylene and its physical properties are shown in Table 1 below.

No Mixing ratio Properties PP G / F
Glass
Bubble importance Impact strength The tensile strength Elongation Flexural strength Flexural modulus g / cm3 kgf / cm kgf / cm2 % kgf / cm2 kgf / cm2 One 80 17 3 1.018 10.0 237 30 324 20,666 2 78 17 5 1.016 10.7 250 36 310 20,440

In this manufacturing method, recycled polypropylene and semi-finished glass bubble are put into a large ribbon mixer, mixed for 30 to 2 hours, and then put into a main hopper, and a glass fiber bar is put into a side feeding hopper, and the twin screw extruder is prepared at the ratio shown in Table 1 above. It is injected into pellets by extrusion.

As shown in Table 1, the specific gravity was 1.02 or less, and the impact strength was 10kgf / cm and the flexural modulus was 20,000kgf / cm 2, respectively.

The composite polypropylene and the physical properties of the talc and the semi-finished glass bubble instead of the glass fiber were shown in Table 2 below.

No
Mixing ratio Properties PP
G / F
Glass
Bubble importance
Impact strength
The tensile strength
Elongation
Flexural strength
Flexural modulus
3 80 17 3 1.012 6.9 252 68 352 17,965 4 78 17 5 1.019 8.9 237 81 321 17,095 5 66 17 7 1.023 8.8 232 101 299 15,195

The strength of the flexural modulus, etc., was slightly lower than that of glass fiber, and the specific gravity exceeded 1.02 and the lightness was slightly lower when the amount of polypropylene was reduced.

Claims (5)

Light weight stiffening material composition for automobile interior using recycled composite polypropylene. The composition of claim 1 wherein the recycled composite polypropylene consists of a composition of polypropylene, talc, glass fiber, glass bubble semifinished product and rubber. The method according to claim 2, wherein the composition is 50 to 90% by weight of recycled polypropylene, 5 to 20% by weight of talc, 10 to 30% by weight of glass fiber, semi-finished glass bubble 1 to 20, rubber 5 to 20% by weight. The method according to claim 2, wherein the ratio of the recycled polypropylene: glass fiber: glass bubble semifinished product is 15-25: 3-5: 1. The method according to any one of claims 2 to 4, wherein the recycled polypropylene has a melt index of 18 g / 10 minutes or more, a tensile strength of 180 kgf / cm 2 or more, elongation of 110% or more, and a specific gravity of 0.99 or less.