KR100475873B1 - Polypropylene-based resin composition for enhancing the paintability - Google Patents

Abstract

The present invention relates to a polypropylene-based powder resin composition for automobile interior materials, and more particularly, to a polypropylene-based terpolymer having a high melt melt index; Olefin rubbers and styrene rubbers; And an olefinic rubber grafted with a polar monomer; an appropriate amount of process oil, thereby providing a low temperature impact resistance, excellent heat resistance, no smell, and a resin composition capable of adhering with a surface treatment agent and a urethane foam layer without a primer. Polypropylene-based powder resin composition for automotive interior instrument panel (skin panel), which enables powder slush molding to powder the average particle into 200 ~ 300 ㎛ size through freeze-pulverization using liquid nitrogen It is about.

Description

Polypropylene-based resin composition for enhancing the paintability

The present invention has excellent low temperature impact resistance, heat resistance, no odor, excellent powder slush molding (Powder Slush Molding) moldability, and excellent coating properties with a surface treatment agent without the need for a coating primer, polypropylene-based powder resin for automotive interior materials More particularly, the composition relates to high melt index polypropylene terpolymers, olefin rubbers, styrene rubbers, and olefin rubbers in which a polar monomer is graft copolymerized. The resin composition added by content is powdered into an average particle size of 200 to 300 μm through freeze-pulverization using liquid nitrogen to enable powder slush molding, and for automotive interior panel instrument skins. The present invention relates to a polypropylene powder resin composition.

Polyvinyl chloride resin, which is currently used in many parts as interior materials for automobiles, can be molded for various prices and has good mechanical properties due to its excellent price, in panel, door trim, sunvisor, etc. It is widely used as a skin material of automobile interior materials, and an automobile interior mat backing material. However, the polyvinyl chloride resin has been steadily promoted to be replaced by other materials due to the movement of regulations in various countries around the world due to the heavy metals contained in the odor and heat stabilizer caused by a large amount of plasticizer.

In-car interior panels have a three-layer structure, and as a skin material, a blend of polyvinyl chloride or acrylonitrile-butadiene-styrene terpolymer and polyvinyl chloride has been used. . It is mainly produced by powder slush molding or by blow molding. The intermediate layer is a polyurethane foam, and the core layer is made of polycarbonate and acrylonitrile-butadiene-styrene terpolymer. Blends are mainly used.

As mentioned in the case of the above skin material, there are two types of molding methods, powder slush molding and blow molding, and now, the pressure molding method mainly consists of a high productivity and a relatively low price of raw materials compared to powder slush molding. . However, this method has the disadvantage that the appearance of the product is lower than that of powder slush molding due to the material loss and the local loss of the surface emboss due to the molding method. Therefore, the need for powder slush molding in terms of appearance quality is great.

Powder slush molding molding is a method of manufacturing a skin material by spraying and melting a powder-shaped resin in a mold heated by heating, and can be molded into a normal product only by having a rapid melting speed in the molding method. In that sense, polyvinyl chloride, a single material produced by polymerization, has several advantages in terms of powder powder properties and melt rate.

However, polyvinyl chloride, which is mainly used as a powder slush molding, is inferior in heat resistance and low temperature impact due to the characteristics of the material itself, so it is invisible passenger airbag for the recent increase in the warranty period and the quality of the product. Low temperature characteristics and heat resistance in the introduction of the technology not only adversely affect the deployment of the airbag, but also have a significant change in appearance due to the use of a plasticizer and a weakness in which the plasticizer is deposited after the surface transition on the windshield, and used to improve the heat resistance. The heat stabilizer contains a large amount of heavy metals, and it is emerging as a material that should be urgently replaced in terms of the physical properties of the material itself and the extension of the warranty period and environmental aspects, which are being recently strengthened in the automobile field.

In order to solve this problem, the present inventors have previously filed a resin composition of a suitable combination of polypropylene terpolymer, styrene rubber, olefin rubber, and processing oil through low temperature freeze grinding in Korean Patent Application No. 2002-30283. It has already been shown that when powdered to a certain particle size, it is not only excellent in molding of in-plane skin powder slush molding but also excellent in odor, heat resistance and low temperature impact.

However, the resin composition has a fatal weakness in paintability due to mainly using an olefinic material. In the case of the interior material of automobiles, urethane and epoxy surface treatment agents are applied due to color and gloss adjustment and scratch problems on the surface, and primers are used to give adhesion due to the weak polarity of olefin materials. As a result, there is a burden of cost increase and the stability of the coating adhesive strength is not satisfactory despite the use of primers.

Accordingly, it is very important to develop a composition for automobile in-panel of a powder slush molding molding method having excellent coating property with a surface treatment agent and adhesive property with a foam layer without a primer. In developing such a material, an important point is to develop a material having excellent physical properties such as impact and heat resistance as a skin material, an excellent powder slush molding molding method, and excellent adhesion to a surface treatment agent and a foam layer.

Therefore, the problem to be solved is to find an appropriate material composition that has excellent low-temperature impact strength and heat resistance, excellent soft feel, fast melting speed when forming powder slush molding, and has a certain polarity characteristic for paintability. Can be.

Accordingly, the inventors of the present invention, in order to solve the conventional problems, a resin in which a certain amount of olefinic rubber graft copolymerized with a polar monomer is added to a resin composition composed of a suitable combination of polypropylene terpolymer, styrene rubber, olefin rubber, processing oil When the composition is powdered to a particle size of a certain size through low temperature freeze-pulverization, the present invention was completed by confirming that the automotive in-panel skin material powder slush molding molding and surface treatment agent and adhesiveness with the foam layer were excellent.

Therefore, the present invention is an odorless and excellent in hardness, flexibility, heat resistance, low temperature impact and powder slush molding moldability, as well as adhesion of the surface treatment agent and the foam layer without the primer process, the in-panel skin The purpose is to provide a resin composition for reuse.

Another object of the present invention is to provide an automotive interior inpanel skin material using the resin composition and a method of manufacturing the same.

The present invention is based on 100 parts by weight of the total composition,

(A) 1 to 40 parts by weight of a polypropylene terpolymer of solid solution melt index;

(B) 10 to 50 parts by weight of styrene rubber;

(C) 10 to 50 parts by weight of the ethylene-α-olefin copolymer rubber;

(D) 1 to 20 parts by weight of the processing oil;

(E) Polar monomer Grafted ethylene-α-olefin rubber copolymer 20 to 40 parts by weight, characterized in that the polypropylene-based resin composition for automobile interior inpanel skin material powder slush molding molding.

In addition, the present invention is a method for manufacturing a car interior material paneling material,

The resin composition of the above-mentioned substrate is characterized in that the method for producing the interior material of an automotive interior panel is characterized in that the particle size is freeze-pulverized to 200-300 µm under liquid nitrogen and manufactured by powder slush molding.

In another aspect, the present invention includes an automotive interior paneling skin produced by the above method.

Hereinafter, the present invention will be described in more detail.

Unlike the existing polypropylene, the present invention uses a polypropylene terpolymer having a very high melt index and a relatively low melting point compared to the conventional polypropylene, and uses styrene-ethylene-butadiene-styrene for low temperature impact and soft feeling. Ethylene-Butadiene-Styrene) copolymer was added, and processing oil was introduced to increase the melting rate of rubbers based on olefinic rubber and copolymer rubber grafted with polar monomer added for imparting paintability.

When explaining each component of the resin composition of this invention more concretely, it is as follows.

(A) Polypropylene Terpolymer of Solid Melt Index

The first component of the polypropylene terpolymer of the high melt melt index is used for improving the powder slush mold formability and heat resistance and low hardness.

The polypropylene terpolymer may have the advantage that the melting point is lowered by 10 to 20 ° C. or more compared to the conventional polypropylene using butene as a third component, unlike polypropylene composed of propylene alone or propylene-ethylene. In addition, the stiffness is also low to maintain the hardness of the composition compared to the conventional polypropylene. In addition, by introducing a controlled technology using peroxide to prepare a copolymer of high melt melt index of 80 g / 10 minutes (230 ℃, 2.16Kgf) or more, the polypropylene is very suitable for molding powder slush molding in use Can be.

These polypropylene terpolymers decompose terpolymers containing 3 to 20 wt% of ethylene and 1-butene in propylene and having a melt index of 1 to 30 g / 10 min (230 ° C, 2.16 Kgf) with molecular weight regulators. It is. The polypropylene terpolymer has a melt index of 80 g / 10 minutes (230 ° C., 2.16 Kgf) or more, preferably, a melt index of 80 to 300 g / 10 minutes (230 ° C., 2.16 Kgf). good.

At this time, as the molecular weight regulator, a peroxide is used, for example, lauryl peroxide, dicumyl peroxide, bis (t-butylperoxyisopropyl) benzene [Bis (t-butylperoxyisopropyl) benzene ], 2,5-dimethyl-2,5-di (t-butylperoxy) hexane [2,5-dimethyl-2,5-di (t-butylperoxy) hexane], 2,5-dimethyl-2,5 -Di (t-butylperoxy) hexane-3 [2,5-dimethyl-2,5-di (t-butyl peroxy) hexane-3].

The content of the polypropylene terpolymer as the component (A) is used in an amount of 1 to 40 parts by weight based on 100 parts by weight of the total composition, and if the content is less than 1 part by weight, there is a problem in moldability and heat resistance, and 40 parts by weight. If exceeded, there is a problem of rapid increase in hardness and low temperature of impulse, which is not preferable.

(B) styrene rubber

In addition, the resin composition of the present invention can control the low-temperature impact strength and hardness using styrene rubber and olefin rubber as the second and third components.

The styrene-based rubber of (B) is excellent in low-temperature impact strength and soft feel due to its unique structure. The styrene-based rubber has mechanical properties, such as vulcanized rubber, even at a relatively low viscosity, and has a low temperature impact characteristic of low glass transition temperature -80 ℃, which can measure the low temperature properties of the material. In addition, it is excellent in absorbing process oils and various fillers and has excellent performance on odors and can be used in various applications such as adhesives, impact modifiers, and rubber substitutes.

The styrene-based rubber of the present invention is preferably a styrene copolymer rubber composed of styrene, butadiene and ethylene copolymer, more preferably 10 to 60% by weight of styrene and 40 to 90% by weight of the sum of butadiene and ethylene. Styrene copolymer rubber having a melt index of 10 to 60 g / 10 min (200 ° C., 5 Kgf). The styrene, butadiene, and ethylene bonds, depending on the form of the two-dimensional copolymers, terpolymers, star-shaped terpolymers, such as a variety of forms exist, for example, the hardness of Shore 20 ~ 80A can be used. In addition, the styrene-based rubber is 20 to 40% by weight of styrene, the sum of butadiene and ethylene is 60 to 80% by weight, the melt index is 20 g / 10 minutes or more, the hardness of Shore 40A or less to use the low temperature impact and moldability More preferred in terms of balance.

The content of the styrene-based rubber (B) component is used in 10 to 50 parts by weight with respect to 100 parts by weight of the total composition, the content is less than 10 parts by weight of the soft feeling and low temperature impact is lowered, if it exceeds 50 parts by weight of the material There is a problem that toughness and rigidity are severely lowered and powder slush molding moldability is lowered. In addition, the rubber is a very expensive material and the pressure is severely increased.

(C) Ethylene-α-olefin Copolymer Rubber

The third component (C) ethylene-α-olefin copolymer rubber is used to improve impact resistance and lower hardness. The ethylene-α-olefin copolymer rubber is a copolymer of ethylene and an α-olefin having 2 to 10 carbon atoms, and α-olefins include propylene, butene, pentene, hexene, propene, octene and the like. As such ethylene-α-olefin copolymer rubber, ethylene-propylene rubber (EPR), ethylene-propylene-diene rubber (EPDM), ethylene-octene rubber (EOR) and the like can be used. Among these, in the case of ethylene-octene rubber, the length of the side chain of octene which is a comonomer is long, and since it is excellent in impact resistance at low temperature, it can use especially preferably. As the ethylene-octene rubber, an octene content of 10 to 40% by weight, a Mooney viscosity of 10 to 50 (ML1 + 4, 121 ° C) may be used, more preferably an octene content of 20 to 35% by weight, It is good to use a thing with a Mooney viscosity of 20-50. That is, the olefin rubbers may be ethylene-propylene, ethylene-butene, ethylene-octene, etc., but in view of the low temperature impact portion, which is the object of the present invention, the low temperature impact strength is very excellent, and is widely used for impact resistance modification. Preference is given to using commercially available ethylene-octene rubbers (US Dupont-Dow Elastomers).

The content of the ethylene-α-olefin copolymer rubber of (C) is used in an amount of 10 to 50 parts by weight based on 100 parts by weight of the total composition. When the content is less than 10 parts by weight, the soft feeling and low temperature impact are lowered, and 50 parts by weight. If exceeded, there is a problem that the toughness and rigidity of the material is severely lowered and the powder slush molding formability is lowered.

(D) processing oil

In the case of the styrene-ethylene-butadiene-styrene copolymer and ethylene-octene rubber, the melt rate is low when the powder slush molding is used, and thus the molding stability is not excellent, which is mainly due to the high molecular weight. Therefore, the present invention adds (D) covalently to the fourth component to reinforce the flexibility (low hardness) and formability of the composition.

The processing oil penetrates the molecular chain of the rubber to straighten the chain, so that the processability is very good and the hardness is excellent. Such processed oil is a kind of softener. Softener is a generic term for rubber compounding oil which is intended to facilitate the flexibility and processability of rubber and to increase the volume, and is divided into process oil and extender oil. Are called process oils.

Processed oil is used to increase the workability, processability, and flexibility of rubber, and paraffinic, naphthenic, and aromatic oils are preferred, and paraffinic is preferable in terms of odor. Therefore, the use of the processing oil not only increases the processability of the impact resistant rubber having a high molecular weight, but is also advantageous in making a low hardness product of a desired level even with a low rubber content. That is, when the processing oil is introduced into the powder slush molding, it is expected to improve the melt rate relatively while maintaining impact resistance and low hardness.

The paraffinic oils include normal paraffine and iso-paraffins, and have little discoloration contamination and excellent odor in terms of rubber, while low in strength and excellent in compressibility, low temperature, and stain resistance. Is low. Naphthenic is intermediate between paraffin and aromatic, and has good pollution resistance, low temperature property, processability, aging resistance, and cold resistance, but its tensile strength and elasticity are not good. In the case of the aromatic system as well as naphthenic system, various physical properties are good, but has a weak point in the smell problem. Therefore, in terms of odor, which is one object of the present invention, it is preferable to use paraffin system. Paraffin-based oils may have various types of 10 to 800 centistokes (cSt, 40 ° C.) depending on kinematic viscosity, but it is preferable to use high molecular weight products of 400 to 600 centistokes to prevent surface migration.

The content of the processed oil of (D) is used in 1 to 20 parts by weight based on 100 parts by weight of the total composition, if the content is less than 1 part by weight there is a problem that does not impart proper moldability to the rubber, more than 20 parts by weight If this happens, the process oil may transfer to the surface, causing serious contamination of the windshield glass of the vehicle.

(E) Polar monomer grafted ethylene-α-olefin copolymer rubber

The polar monomer grafted ethylene-α-olefin copolymer rubber of (E) is used as the fifth component to improve adhesion to the surface treatment agent and the foam layer of the final resin composition.

The polar group graft rubber is a rubber in which a monomer having various kinds of polar groups is bonded to the side chain of the rubber by chemical reaction using an organic peroxide as an initiator to the ethylene-α-olefin copolymer rubber of the component (C). The production method may be prepared in a reactor using a general extruder or in solution. In the ethylene-α-olefin copolymer rubber of the component (C), 0.5 to 2% by weight of a polar monomer is grafted to the copolymer, and the greater the content of the polar monomer, the higher the coating adhesion. The higher the content rate of the polar monomer is, the better. The monomers include methacrylates such as maleic anhydride methyl methacrylate, ethyl methacrylate, glycidyl methacrylate, and acrylates. There is Ryu. Of these, maleic anhydride or glycidyl methacrylate is preferably grafted to ethylene-propylene rubber and ethylene-octene rubber, and a monomer content of 0.5% or more is preferable, and if possible, a Mooney viscosity of 40 (121 ° C, ML1 + 4) It is preferable to graf the polar monomer to the following rubbers.

Since the component (E) has a polar group and has no primer, it also has strength in adhesion to the surface treatment agent and the foam, and the rubber itself is basically intact so that it does not significantly affect low temperature impact and low hardness. It can play a big role in finding a resin composition according to the object of the invention.

The content of the polar monomer grafted ethylene-α-olefin copolymer rubber (E) is used in an amount of 20 to 40 parts by weight based on 100 parts by weight of the total composition, and when the content is less than 20 parts by weight, the effect of coating adhesion is very low. If it is not large and is 40 parts by weight or more, the polarity characteristic is excessively transferred to the surface, so that the releasability in the mold after powder slush molding is a problem.

In addition, the present invention can manufacture a vehicle interior material in-panel skin material using the resin composition. The automotive interior paneling skin may be prepared using a conventional method, and preferably, the resin composition is freeze-pulverized under liquid nitrogen and powder slush molding is carried out. It is preferable that the particle size at the time of pulverization is in the range of 200 to 300 μm, and in this case, if the particle size is out of the above range, there is a problem that moldability is poor.

As described above, the resin composition according to the present invention uses a polypropylene terpolymer of a high melt index thermally decomposed into a peroxide for formability, and lowers the hardness and adds styrene and olefin rubbers added for low temperature impact reinforcement. The olefinic rubber grafted with a polar monomer that enables coating without hardness, low temperature impact, and primer is used to increase the melt rate of the rubber and to formulate a processing oil capable of maintaining low hardness with low rubber content. Shore 70 ~ 80A, odorless, excellent in flexibility, heat resistance, low temperature impact and powder slush molding moldability, as well as excellent adhesion to the olefinic rubber with polar group by chemical reaction with coating paint, eliminating primer process In addition, most of the components are olefin-based, so odor and heavy metal content problems none.

Therefore, the resin composition of the present invention can contribute to the increase in sales of automobiles by avoiding restrictions on exports of automobiles through the improvement of durability of inpanel and improvement of odors and heavy metal content problems to cope with the increased warranty period in the future, and the primer process. It can also contribute to securing cost competitiveness and environmentally friendly aspects.

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

Examples 1-4

Examples 1 to 4 prepared a polypropylene resin composition with the composition and content shown in Table 1 below. At this time, the conditions of each (A), (B), (C), (D), and (E) component are as follows.

(A): polypropylene terpolymer having a melt index of 120 g / 10 minutes or more,

(B): styrene-based copolymer rubber having 20% by weight of styrene, butadiene and ethylene is 80% by weight, melt index of 25 g / 10 minutes or more, Shore 42A,

(C): ethylene-octene rubber having a Mooney viscosity of (ML1 + 4, 121 ° C) 35 and an octene content of 35% by weight,

(D): Paraffin-based processing oil having a kinematic viscosity of 500 centistokes (40 ° C)

(E): Ethylene-propylene copolymer rubber having a melt index of 25 g / 10 min (230 ° C., 2.16 Kgf) and 2% by weight of glycidyl methacrylate

That is, the resin composition mixed in the content shown in Table 1 was mixed for 5 minutes in a tumbler mixer, and then extruded and cooled to a solid screw extruder at 190 to 220 ° C to obtain a pellet-like composition. Each composition obtained was ground to a size of 250 μm through a freeze mill using liquid nitrogen. The pulverized powder is placed in a 20cm × 20cm × 10cm box and installed in a 20cm × 20cm rectangle heated for 30 minutes in a 400 ℃ oven under an electroforming mold made of nickel and silicone resin, and then rotated left and right to manufacture a sheet. Was measured for the above evaluation items and the results are shown in Table 2.

Comparative Example 1

In Comparative Example 1, polyvinyl chloride (PVC), which is currently commercially available, was evaluated in molding in the same manner as in Example.

Comparative Examples 2 to 4

Comparative Example 2 did not use (E) in the composition of Example 1, Comparative Example 3 is less than 10 parts by weight of the component (E), 40 parts by weight of the component (E) in Comparative Example 4 the same as in the above Example Table 1 shows the results of the evaluation after the molding.

Ingredients (parts by weight) (A) polypropylene terpolymer (B) Styrene Copolymer Rubber (C) ethylene-octene rubber (D) Paraffinic Processing Oil (E) Ethylene-propylene copolymer rubber Example 1 30 20 20 10 20 Example 2 30 20 10 10 30 Example 3 30 10 10 10 40 Example 4 30 10 10 20 30 Comparative Example 1 Polyvinyl chloride Comparative Example 2 30 30 30 10 - Comparative Example 3 30 30 25 10 5 Comparative Example 4 30 10 5 10 45

The physical property evaluation method of the various compositions adopted by the following examples and comparative examples was carried out by the following test method, the results obtained are shown in Table 2 below.

(1) Shore A hardness:

The test was conducted according to JIS K 6301 and measured on a 15 cm × 15 cm × 0.6 cm size specimen using a Shore hardness tester of Zwick, Switzerland. Retention time was 10 seconds.

(2) heat aging resistance:

The sheet formed by powder slush molding in a hot air circulating oven at 120 ° C. was evaluated for the crack state and the change rate of tensile strength of the surface after standing for 500 hours. The results are shown in Table 1 below.

(3) low temperature impact:

The sheet prepared by the powder slush molding method was fixed to a cup-type mold, and then left standing for 4 hours in a -40 ° C chamber, and a shape of 50 mm diameter and 5 kg mass freely falling at 1 m height was observed to be broken. It was evaluated that the low-temperature impact property was low when debris was formed during brittle behavior during fracture.

(4) smell:

The smell was cut into 10cm × 10cm × 1.5cm sheets made of powder slush molding, put into a sealed container of 4 liter capacity, heated at 602 ℃ for about 1 hour 20 minutes, cooled for 20 minutes, and then smell was measured. . Odor evaluation was performed by five people, and the total number of people who evaluated odor was evaluated by subtracting from five. Normally, automotive companies wanted a level of 4 or better.

(5) Fogging Value:

The soaking odor was cut into a sheet made of powder slush molding into a 70 mm diameter circle, placed in a beaker, covered with a clean glass plate, and heated at 100 ° C. for 4 hours by placing a bath in a container filled with silicone oil. After heating, the glass plate was measured with a hazemeter.

(6) formability:

The moldability is heated to an electric casting mold consisting of nickel and silicone resin in a rectangle of 20cm × 20cm for 30 minutes in an oven at 400 ° C., freeze-pulverizing the composition of Table 1, powdered and sprayed onto the surface to form the surface of the rear surface. Evaluation was based on smoothness.

(7) powder particle size;

Freeze-pulverized powder was passed through each mesh according to ASTM Standard E-11 to calculate the weight of each mesh and the weight of the passage and residual amount. Using the conversion table, the average size of the powder particles was expressed in terms of μm.

(8) Paint adhesion

Peel strength (180o, Peel Strength) for paintability test was applied to a two-component urethane-based paint with a thickness of 50㎛ without pretreatment, dried at 90 ° C for 30 minutes, and allowed to stand at room temperature for 48 hours to prepare a test piece for measuring paintability. Got it. The test piece thus prepared was cut into a width of 1 cm and a length of 15 cm, and then measured by an Instron universal tester.

division Average particle size (㎛) Hardness (A) Heat aging Low temperature impact Litter smell Formability Peeling strength (g / cm) Example 1 250 71 Prize Prize 2 4 Prize 1,100 Example 2 250 72 Prize Prize 2 4 Prize 1,200 Example 3 250 74 Prize Prize 2 4 Prize 1,245 Example 4 250 67 Prize Prize 3 4 Prize 1,170 Comparative Example 1 180 71 Ha Ha 2 2.5 Prize 1,230 Comparative Example 2 250 71 Prize Prize 2 4 Prize 457 Comparative Example 3 250 73 Prize Prize 13 4 Prize 570 Comparative Example 4 250 73 Prize Prize 2 4 Of ¹⁾ 1,280  1) Good moldability but bad mold release when mold release, so sheet is locally stretched and torn.

In Table 2, both the low-temperature impact properties and the moldability of Examples 1 to 4 of the present invention were excellent, and the coating film peeling strength, which is an object of the present invention, was also equivalent to that of polyvinyl chloride. On the other hand, polyvinyl chloride of Comparative Example 1 was excellent in paint adhesion and formability, but exhibited weakness in low temperature impact and heat aging. Comparative Example 2 showed a weakness in the coating adhesion as in the conventional olefinic material, 5 parts by weight in Comparative Example 3 did not have a significant difference from not using the (E) component, Comparative Example 4 is excessive use of the (E) component As a result, many problems were revealed in mold release after molding.

As described above, the powder resin composition for automobile in-panel skin powder slush molding of the present invention has a high melt index polypropylene terpolymer and a polar monomer in a styrene-butadiene-ethylene-styrene rubber and ethylene-octene rubber mixture. Powder slush molding improves moldability, impact resistance and heat resistance by using graft copolymerized olefin rubber and processing oil, and has excellent flexibility, no smell and no heavy metals. In addition to the improvement of the technical aspects, it is possible to secure the desired level of coating adhesion even without the primer treatment process, which is inevitably required during the coating, which was recognized as a weak point of the existing soft olefinic material. Can contribute in terms of

Claims (8)

Per 100 parts by weight of the total composition, (A) 1 to 40 parts by weight of a polypropylene terpolymer of solid solution melt index; (B) 10 to 50 parts by weight of styrene rubber; (C) 10 to 50 parts by weight of the ethylene-α-olefin copolymer rubber; (D) 1 to 20 parts by weight of the processing oil; And (E) 20 to 40 parts by weight of polar monomer grafted ethylene-α-olefin copolymer rubber A polypropylene-based resin composition for molding a powder slush molding for automobile interiors that can be painted without a primer process. According to claim 1, wherein the polypropylene terpolymer of (A) is A ternary copolymer obtained by decomposing a propylene copolymer containing a ethylene and 1-butene in an amount of 3 to 20% by weight and having a melt index of 1 to 30 g / 10 minutes (230 ° C, 2.16 Kgf) by a molecular weight modifier. The terpolymer is a resin composition, characterized in that the melt index is 80 ~ 300 g / 10 minutes (230 ℃, 2.16Kgf). The styrene rubber of claim 1, wherein Ternary copolymer rubber composed of 10 to 60% by weight of styrene and 40 to 90% by weight of butadiene and ethylene, and the styrene-based rubber has a melt index of 10 to 60 g / 10 minutes (200 DEG C, 5 Kgf). Resin composition, characterized in that. The ethylene-α-olefin copolymer rubber according to claim 1, wherein the ethylene-α-olefin copolymer rubber of (C) is an ethylene-octene rubber having an octene content of 10 to 40% by weight and a Mooney viscosity of 10 to 40 (ML1 + 4, 121 ° C). Resin composition characterized by the above-mentioned. 2. The resin composition according to claim 1, wherein the processing oil of (D) is paraffin, aromatic, or naphthenic processing oil having a kinematic viscosity of 10 to 800 centistokes (cSt, 40 ° C). The rubber composition according to claim 1, wherein the rubber of (E) is a 0.5-2 wt% graft copolymer of maleic anhydride, methacrylate-based, or acrylate-based monomers in an ethylene-α-olefin copolymer rubber. In the manufacturing method of the automotive interior material in-panel skin material, A method for producing an automotive interior paneling skin material, wherein the resin composition of claim 1 is prepared by low temperature freeze-pulverization and powder slush molding molding under liquid nitrogen to an average particle size of 200 to 300 µm. An automotive interior paneling material manufactured by the method comprising the resin composition of claim 1.