KR101215729B1 - Thermoplastic elastomer resin with high flow property - Google Patents

Abstract

The present invention comprises (A) 5 to 35% by weight polypropylene resin, (B) 5 to 50% by weight thermoplastic elastomer, (C) 20 to 40% by weight processing oil, and (D) 1 to 30% by weight inorganic filler It relates to a thermoplastic resin composition.

High flow, flowability, automotive, interior parts, skin, polypropylene resin, thermoplastic resin,

Description

Thermoplastic elastomer resin with high flow property

The present invention relates to a thermoplastic resin composition having high flow characteristics, which is suitable for the skin of large interior parts such as door trim panels, instrument panels, etc. of automobiles.

In order to express the luxurious feeling of automobile interior materials, resin compositions made of PPF or PC / ABS are injected, and then the skin trimming and coating are made by attaching or coating the skin material made through various processes to enhance the sensitivity of door trim panels or instrument panels. This is being used. However, this process is a complicated process and there is a problem that the price of the product rises, it is applicable only to some high-end models. However, current consumers are demanding such a luxury not only luxury cars but also because of the importance of emotional quality. Therefore, the need to develop a material technology that can express the feeling of high-quality materials, which can be applied to general vehicles by simplifying the process and lowering the product cost.

When the partially developed crosslinked thermoplastic elastomer and the fully crosslinked thermoplastic elastomer are applied, the flow flowability is very low, so that double injection over a large injection molding is not easy. Even if the injection is attempted using these, even if the injection is made, it is difficult to apply to the door trim panel or the instrument panel because a short shot or a flow mark is generated. In addition, when the double injection by applying a polyolefin resin having a high flow characteristics developed in the existing high hardness, there is a problem that it is difficult to express a luxurious, soft feeling.

In this regard, US Pat. No. 6,207,754 relates to a thermoplastic olefin composition which is applicable to automotive interior skin preparations, comprising: (A) 40 to 60% by weight of impact modified polypropylene resin (B) 87 to 97.5 mol% 10 to 70% by weight (C) of a separate olefin copolymer elastomer having a density of 0.865 to 0.920 g / cc and a weight average molecular weight of 70,000 or more (C) a coupling agent and an activator compound It includes, and proposes a resin composition having a melt index of 0.5 ~ 5g / 10min of the thermoplastic olefin composition thus prepared. The thermoplastic olefin composition is a resin composition for calendering, and has a low melt flowability, so when it is applied to a double injection of a large product requiring high flow flowability for the skin agent, an unmolded or flow mark is generated and applied. it's difficult.

In addition, the Republic of Korea Patent 10-2002-0042507 discloses a polyolefin resin composition having a high flow characteristics for the application of large injections. (A) A homopolymer or propylene-ethylene copolymer of propylene, having a melt index of 20 to 80 g / 10 min (230 ° C.) and a high crystalline polypropylene resin of 60 to 80 wt%, having an isotactic index of 97 to 100, ( B) 10-30% by weight of ethylene-α-olefin copolymer rubber, and (C) talc, calcium carbonate, calcium sulfate, magnesium oxide, calcium stearate, mica, silica, calcium silicate, clay and carbon black It proposes a polypropylene resin composition containing 7 to 25% of at least one inorganic filler selected. However, the composition is not suitable as a double injection material for the skin material such as door trim panel or instrument panel of the automobile because it is difficult to express a soft and luxurious feeling due to the lack of rubber content showing soft properties.

The present invention solves the problems of the prior art as described above, exhibits a smooth texture and flexibility while having a high melt flow characteristics to enable double injection on a large water, and also complete the product by a single process of double injection. It is an object of the present invention to provide a thermoplastic resin composition which is very economical.

The present invention comprises (A) 5 to 35% by weight polypropylene resin, (B) 5 to 50% by weight thermoplastic elastomer, (C) 20 to 40% by weight processing oil, and (D) 1 to 30% by weight inorganic filler It relates to a thermoplastic resin composition.

Hereinafter, the present invention will be described in detail.

(A) polypropylene resin

Polypropylene resin used in the present invention is a propylene homopolymer; Copolymers of propylene and ethylene; And one or two or more selected from the group consisting of terpolymers of propylene, ethylene and α-olefin can be used, the usable melt index (230 ℃, 2.16Kg) is in the range of 0.1 ~ 100g / 10min, Preferably it is resin in the range of 0.1-60 g / 10min. If the fluidity is lower than 0.1g / 10min, there is a problem that the flow characteristics of the product is lowered, if the fluidity is higher than 100g / 10min it is difficult to process the Banbary Kneader (Banbary Kneader). As the α-olefin monomer, one or more selected from ethylene, 1-butene, 1-pentene and 1-hexene may be used.

The polypropylene resin may be included in 5 to 35% by weight based on the total composition, preferably 10 to 28% by weight. If the content is less than 5% by weight, the mechanical properties such as tensile strength of the final product is lowered, if more than 35% by weight there is a problem that the desired soft feeling is lost to increase the hardness.

(B) thermoplastic elastomer

The thermoplastic elastomer used in the present invention is an α-olefin copolymer, an olefin copolymer rubber, or a styrene copolymer.

Among the α-olefin copolymer resins or olefin copolymer rubbers, a random copolymer obtained by partially crystalline or copolymerizing two or more mono olefins as an amorphous material may be used. In particular, copolymerization is based on ethylene and propylene. Preference is given to using ethylene-propylene-diene terpolymer copolymer rubber or ethylene-propylene rubber (Ethylene-propylene-rubber).

Representative examples are selected from the group consisting of dicyclo pentadiene, 1,4-hexaexene methylene norbonene, ethylidene norbonene and derivatives thereof It is preferable to use, and it is more preferable to use the ethylene-propylene-ethylidene norbornene copolymer which has a high crosslinking reaction rate more preferably.

The olefin copolymer rubber is ethylene-propylene-dicyclopentadiene, ethylene-propylene-1,4-hexadiene, ethylene-propylene-methylenenorbornene, ethylene-propylene-ethylidene-norbornene, ethylene-propylene-cyclohexa It is preferable that it is 1 or more types chosen from the group which consists of dienes and these derivatives.

The styrene-based copolymer is preferably a copolymer elastomer of styrene and an aliphatic unsaturated hydrocarbon having 2 to 10 carbon atoms. The styrene-based elastomer is styrene-butadiene-styrene copolymer elastomer (SBS), styrene-isoprene-styrene copolymer elastomer (SIS), styrene-ethylene-propylene-styrene copolymer elastomer (SEPS), styrene-ethylene-butylene- Preference is given to styrene copolymer elastomers (SEBS) or mixtures thereof.

It is preferable that the said thermoplastic elastic body is pattern viscosity ML1 _{+ 4} 125 degreeC 20-100.

The thermoplastic elastomer may be included in 5 to 50% by weight based on the total composition, preferably 10 to 40% by weight. If the content is less than 5% by weight, the content of non-conjugated dienes, which may cause crosslinking reaction, decreases, resulting in poor physical and chemical properties due to the low degree of crosslinking. It is difficult to apply to products that require flow characteristics.

(C) processing oil

The processing oil used in the present invention is used to improve processability and physical properties, and is generally paraffin-based, naphthene-based, or aromatic-based, but preferably has a ignition temperature. It is recommended to use paraffin mineral oil in the range of 250 ~ 580 ℃. The use of aromatic oils is undesirable because it presents odor problems and limitations in color implementation.

The processing oil may be included in 20 to 40% by weight based on the total composition, more preferably 32 to 40% by weight. If less than 20% by weight, there is a problem that the fluidity of the material is lowered, if it exceeds 40% by weight, there is a problem of poor productivity productivity, or a problem that the oil of the finished injection molded product.

(D) Inorganic filler

Inorganic fillers used in the present invention include talc, calcium carbonate (CaCO ₃ ), barium sulfate (BaSO ₄ ), aluminum hydroxide (A1 ₂ O ₃ ), titanium dioxide (TiO ₂ ), zinc oxide (ZnO), and oxidation Magnesium (MgO), Mica, Wallastonite, Silica, Clay, Glass Fiber, and Carbon Black may be used one or two or more selected from the group consisting of, and talc is used. It is desirable to. In addition, the inorganic filler is preferably used having a particle size of 0.1 ~ 15μm, more preferably a particle size of 0.1 ~ 10μm or less.

The inorganic filler may be included in 1 to 30% by weight based on the total composition, preferably 5 to 20% by weight. If the content is less than 1% by weight, there is a problem that the use of the inorganic filler is insignificant to increase the gloss in the final molded product. When the content exceeds 30% by weight, the specific gravity is increased, the flow characteristics are reduced, and the aggregation of the inorganic filler Due to the phenomenon, there is a problem that the mechanical properties decrease, which is not preferable.

The thermoplastic resin composition of the present invention may further include an organic peroxide crosslinking agent (E).

Examples of the organic peroxide crosslinking agent include benzoyl peroxide, lauryl peroxide, dicumyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene, di-t-butylperoxide, 2,5- Dimethyl-2,5-di (t-butylperoxyl) hexane, 2,5-dimethyl-2,5-di (t-butylperoxyl) hexane-3, p-chlorobenzoyl peroxide, n-butyl-4 One or more selected from the group consisting of, 4-bis (t-butylperoxy) valate, and 2,4-dichlorobenzoyl peroxide can be used. It is most effective to use 1,3-bis (t-butylperoxyisopropyl) benzene in terms of odor and Scorch stability. In addition, the content can be adjusted according to the degree of crosslinking and fluidity of the final product.

It is preferable that the said crosslinking agent is contained in 0.02-5 weight% based on the total weight of said (A), (B), (C), and (D) component. If it is less than 0.02% by weight, the crosslinking effect is very insignificant, resulting in a problem that the properties of the crosslinked rubber cannot be exhibited. If the content exceeds 5% by weight, the decomposition of the polypropylene resin is accelerated to deteriorate the mechanical properties.

The thermoplastic resin composition of the present invention may further include a crosslinking aid (G).

The crosslinking aid is added to prevent excessive degradation of the polypropylene resin and to maintain the stability of radicals generated by the crosslinking agent. The crosslinking aids that can be used are divinylbenzene, triarylcyanurate, and ethylene glycol dimethacrylate. It may be used one or more selected from the group consisting of, triallyl cyanurate, diethylene glycol dimethacrylate, allyl methacrylate, and trimethylolpropane trimethacrylate. In particular, triallyl cyanurate is effective.

It is preferable that the said crosslinking adjuvant is contained in 0.02-5 weight% based on the total weight of said (A), (B), (C), and (D) component. It is preferably included in 0.1 to 5% by weight. If it is less than 0.1% by weight, there is a problem in that it cannot act as a crosslinking aid added to the crosslinking reaction, and if it exceeds 5% by weight, it may react with other stabilizers to reduce the thermal stability or weather resistance of the final resin. .

In addition to the above components, the thermoplastic resin composition of the present invention may be an antioxidant, an ultraviolet stabilizer, a pigment, a heat stabilizer, a lubricant, a foaming agent, Additives such as antistatic agents can be used in small amounts within the appropriate content range.

Existing injection-type products are manufactured through the three-step process of skin material production (1), injection molding (2), bonding (3), but using the thermoplastic resin composition of the present invention by a single process of double injection Since the process can be completed, cost reduction of about 40% can be achieved due to the shortening of the process.

Hereinafter, the present invention will be described through Examples and Comparative Examples. The following examples are presented as a preferred composition to aid the understanding of the present invention, and are merely illustrative of the present invention, the scope of the present invention is not limited by the above examples.

Example 1: Preparation of Thermoplastic Resin Composition

25 wt% of random polypropylene with melt flow index 1g / 10min, 20 wt% of ethylene propylene diene monomer (EPDM) with a Mooney viscosity of ML1 + 4 125 ° C 50 and 10 wt% of EPDM with a Mooney viscosity of ML1 + 4 125 ° C of 80 %, 35% by weight of processing oil, 5% by weight of Styrene-Ethylene-Butylene-Styrene (SEBS) having a melt index of 5g / 10min, and 5% by weight of inorganic filler talc were uniformly mixed using a preheated half-barrier. . Thereafter, 3% by weight of crosslinking agent, 1.5% by weight of crosslinking aid, 2.0% by weight of other antioxidants and 3.0% by weight of weathering stabilizer were added to the pre-blended product, and then extruded using a twin screw extruder of 190 ° C to 230 ° C, and cooled To obtain a pellet-like composition.

Example 2.

30% by weight of random polypropylene with melt flow index 1g / 10min and 20% by weight of EPDM with ML1 + 4 125 ° C 50 and 10% by weight of EPDM with ML1 + 4 125 ° C 80 and 30% processing oil Except for including the% was carried out in the same manner as in Example 1.

Example 3.

30% by weight of random polypropylene with a melt flow index of 1g / 10min, 10% by weight of EPDM with a Mooney viscosity of ML1 + 4 125 ° C 50 and 20% by weight of EPDM with a Mooney viscosity of ML1 + 4 125 ° C, 80% of processing oil %, And 10% by weight of inorganic filler talc, except that does not contain SEBS was carried out in the same manner as in Example 1.

Comparative Example 1

The same process as in Example 2 was carried out except that the content of the random polypropylene was adjusted to 40% by weight and the content of the processing oil to 20%.

Comparative Example 2

The same procedure as in Example 2 was carried out except that the content of the random polypropylene was adjusted to the content of 45% by weight processing oil to 15% by weight.

Test Example

Performance evaluation

The thermoplastic resin compositions prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were double injection-molded using an injection molding machine having a temperature of 200 ° C., and performance was measured according to the method described for the following evaluation items.

<Flow index>

It evaluated based on ASTMD1238 standard.

Tensile Strength and Elongation

It evaluated based on ASTMD412 standard.

<Hardness>

Evaluation was made according to the ASTM D2240 standard.

<Plasticity>

After double injection molding of the instrument panel, flow traces, weld lines, partial gloss, and appearance were observed.

The test results are shown in Table 1 below.

◎: Very good, ○: Excellent, △: Normal, ｘ: Poor

Propylene: Flow Index 1g / 10min (230 ℃)

EPDM-1: Mooney Viscosity ML1 + 4 125 ° C 50

EPDM-1: Mooney Viscosity ML1 + 4 125 ℃ 80

SEBS: Melt Index 5g / 10min (230 ℃)

Processing oil: Flash point 300 ℃

Inorganic filler: Talc with particle size 5㎛

The present invention provides a thermoplastic resin having excellent injection moldability and soft texture flexibility by controlling the crosslinking degree and flow characteristics of the thermoplastic resin to have high flow flow characteristics.

In addition, the conventional injection-molded product was manufactured through a three-step process of skin material production (1), injection molding (2), and bonding (3), but using the thermoplastic resin composition of the present invention in a single process of double injection As the product can be finished, the cost can be reduced by 40% compared to the existing product due to the shortening of the process.

Claims (16)

Thermoplastic resin comprising (A) 5 to 35% by weight of polypropylene resin, (B) 5 to 50% by weight of thermoplastic elastomer, (C) 20 to 40% by weight of processing oil, and (D) 1 to 30% by weight of inorganic filler Composition. The method of claim 1, wherein the polypropylene resin is a propylene homopolymer; Copolymers of propylene and ethylene; And at least one selected from the group consisting of terpolymers of propylene, ethylene and α-olefin. The thermoplastic resin composition of claim 1, wherein a melt index (230 ° C., 2.16 Kg) of the polypropylene resin is 0.1 to 100 g / 10 min. The thermoplastic resin composition of claim 1, wherein the thermoplastic elastomer is an α-olefin copolymer, an olefin copolymer rubber, or a styrene copolymer. The method of claim 4, wherein the olefin copolymer rubber is ethylene-propylene-dicyclopentadiene, ethylene-propylene-1,4-hexadiene, ethylene-propylene-methylenenorbornene, ethylene-propylene-ethylidene norbornene, It is 1 or more types chosen from the group which consists of ethylene-propylene-cyclohexadiene, and derivatives thereof, The thermoplastic resin composition characterized by the above-mentioned. The thermoplastic resin composition according to claim 4, wherein the styrene copolymer rubber is a copolymer elastomer of styrene and an aliphatic unsaturated hydrocarbon having 2 to 10 carbon atoms. The copolymer elastomer of claim 6 wherein the copolymer elastomer of styrene and aliphatic unsaturated hydrocarbon having 2 to 10 carbon atoms is styrene-butadiene-styrene copolymer elastomer (SBS), styrene-isoprene-styrene copolymer elastomer (SIS), styrene-ethylene-propylene A styrene copolymer elastomer (SEPS), a styrene-ethylene-butylene-styrene copolymer elastomer (SEBS), or a mixture thereof. The thermoplastic resin composition of claim 1, wherein the thermoplastic elastomer has a pattern viscosity of ML _{1 + 4} 125 ° C 20 to 100. The thermoplastic resin composition of claim 1, wherein the processing oil is a paraffin-based mineral oil having a ignition temperature of 250 to 580 ° C. The method of claim 1, wherein the inorganic filler is talc, calcium carbonate (CaCO ₃ ), barium sulfate (BaSO ₄ ), aluminum hydroxide (A1 ₂ O ₃ ), titanium dioxide (TiO ₂ ), zinc oxide (ZnO), MgO, Mica, Wallastonite, Silica, Clay, Glass Fiber, Carbon Black, and thermoplastic resin composition characterized in that at least two or more selected from the group consisting of carbon black. . The thermoplastic resin composition of claim 1, wherein the inorganic filler has a particle size of 0.1 to 15 µm. The thermoplastic resin according to claim 1, further comprising 0.02 to 5% by weight of (E) organic peroxide crosslinking agent, based on the total weight of the components (A), (B), (C), and (D). Resin composition. The method according to claim 12, wherein the (E) organic peroxide crosslinking agent is benzoyl peroxide, lauryl peroxide, dicumyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene, di-t-butyl Peroxide, 2.5-dimethyl-2.5-di (t-butylperoxyl) hexane, 2.5-dimethyl-2.5-di (t-butylperoxyl) hexane-3, P-chlorobenzol peroxide, n-butyl-4.4- A bis (t-butylperoxy) valate, and a thermoplastic resin composition, characterized in that at least one member selected from the group consisting of 2.4-dichlorobenzoyl peroxide. The thermoplastic resin composition according to claim 1, further comprising 0.02 to 5% by weight of (G) crosslinking aid based on the total weight of the components (A), (B), (C), and (D). The method according to claim 14, wherein the (G) crosslinking aid is divinylbenzene, triaryl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, allyl methacrylate, and trimethylolpropane trimethacrylate It is at least one member selected from the group consisting of a thermoplastic resin composition The method according to any one of claims 1, 12, and 14, wherein the antioxidant, ultraviolet stabilizer, pigment, heat stabilizer, lubricant, foaming agent, The thermoplastic resin composition further comprises at least one selected from the group consisting of antistatic agents.