JP2005187713A - Instrument panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an instrument panel having high thermal deformation resistance and high rigidity as well as excellent impact resistance strength and excellent appearance (low glossiness and the like). <P>SOLUTION: The material for the instrument panel uses a polypropylene-based composition consisting of: (A) 60-80 mass% of polypropylene-based resin containing 3-15 mass% of an ethylene-propylene copolymer having 30-55 mass% of ethylene with intrinsic viscosity IV(in tetralin at 135°C) of 5.1-10 dL/g and 5-25 mass% of ethylene-butene copolymer having 60-80 mass% of ethylene with intrinsic viscosity IV(in tetralin at 135°C) of 2.0-5.0 dL/g; (B) 0-10 mass% of ethylene-based copolymer rubber; and (C)10-30 mass% of talc; and (D) 0.01-1.0 mass part of a rosin type nucleating agent for 100 mass parts of the above composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an instrument panel formed by molding a polypropylene resin composition, having high heat distortion resistance and rigidity, and having good impact strength and appearance performance (such as low gloss).

  For interior parts of automobiles, especially instrument panels that require rigidity and impact resistance, an instrument obtained by molding a polypropylene resin composition with improved rigidity by incorporating filler as a reinforcing material in polypropylene Panel: Polypropylene resin composition with improved impact resistance by blending polyethylene or rubber components (eg, polyisobutylene, polybutadiene, amorphous or low crystalline ethylene / propylene copolymer rubber) with polypropylene, etc. An instrument panel obtained in this manner is known (for example, Patent Document 1).

  By the way, since an instrument panel is located in front of the driver's seat of a car, sunlight may hit directly and it may rise to 100 ° C. For this reason, the instrument panel is required to have heat-resistant deformation. In addition, the instrument panel is required to have low gloss material characteristics so that sunlight is not reflected and an automobile driver is not dazzled.

As an instrument panel having low glossiness, an instrument panel obtained by molding a polypropylene resin composition comprising a specific propylene polymer and talc is proposed in Japanese Patent Application Laid-Open No. 9-71691 (Patent Document 2). ing. Moreover, as a polypropylene resin composition for obtaining an instrument panel having excellent heat distortion resistance and low gloss, a polypropylene polymer, talc having a specific particle size, and a specific weight average molecular weight (Mw) are used. The thing which consists of polysiloxane which has is proposed by Unexamined-Japanese-Patent No. 2001-164061 (patent document 3).
However, these polypropylene-based resin compositions have the disadvantage that the amount of talc must be increased and the specific gravity becomes heavier in order to provide high heat distortion resistance while maintaining good impact resistance. It was.
JP 59-47252 A JP-A-9-71691 JP 2001-164061 A

  Accordingly, an object of the present invention is to provide an instrument panel having high heat distortion resistance and rigidity, and excellent impact strength and appearance performance (such as low glossiness).

  As a result of intensive studies in order to achieve the above object, the present inventors have found that an ethylene / propylene copolymer and an ethylene / butene copolymer, which are characterized by intrinsic viscosity and ethylene content, are used as instrument panel materials. It has been found that the object can be achieved by using a polypropylene resin composition containing talc as a filler as a reinforcing material and a rosin nucleating agent as a nucleating agent. It was.

That is, the instrument panel of the present invention has an (A) ethylene / propylene copolymer having an intrinsic viscosity IV (in 135 ° C. tetralin) of 5.1 to 10 dl / g and an ethylene content of 30 to 55% by mass. An ethylene / butene copolymer having a limiting viscosity IV (in 135 ° C. tetralin) of 2.0 to 5.0 dl / g and an ethylene content of 60 to 80% by mass. 60 to 80% by mass of polypropylene resin containing 5 to 25% by mass,
(B) ethylene copolymer rubber 0-10% by mass, and (C) a composition (A + B + C) comprising talc 10-30% by mass,
A polypropylene resin composition containing 0.01 to 1.0 part by mass of (D) rosin nucleating agent is formed by molding with respect to 100 parts by mass of the composition (A + B + C). Is.

  Here, the component (A) other than the ethylene-propylene copolymer and the ethylene-butene copolymer of the polypropylene resin is preferably a homopolypropylene component.

  The instrument panel of the present invention has higher heat distortion resistance and rigidity, and impact resistance and appearance performance (low glossiness) than an instrument panel molded using a conventional polypropylene resin composition. Etc.) is good.

The present invention will be described in detail below.
<(A) Polypropylene resin>
The (A) polypropylene resin in the present invention contains a specific ethylene / propylene copolymer and a specific ethylene / butene copolymer.
Here, the polypropylene resin containing an ethylene / propylene copolymer and an ethylene / butene copolymer is a polypropylene resin produced by a polymerization process of two or more stages, and the polymerization process of the first stage or later And an ethylene / propylene copolymer produced in the second or subsequent polymerization step and an ethylene / butene copolymer produced in the second or subsequent polymerization step. It means a mixture. The polypropylene component is preferably a homopolypropylene component, and more preferably a crystalline homopolypropylene component, from the viewpoint of imparting high heat distortion resistance and rigidity to the instrument panel.

  (A) Polypropylene resin may be one in which crystalline homopolypropylene and ethylene / propylene copolymer or ethylene / butene copolymer are chemically bonded, or crystalline homopolypropylene and ethylene / propylene copolymer. A polymer and an ethylene / butene copolymer may be simply mixed. A mixture of two or more types of crystalline homopolypropylene and an ethylene / propylene copolymer or / and an ethylene / butene copolymer may be used in combination.

(A) The intrinsic viscosity IV (IV = Intrinsic Viscosity) of the ethylene / propylene copolymer contained in the polypropylene resin is 5.1 to 10 dl / g, preferably 5.1 to 8.0 dl / g. . When the intrinsic viscosity IV is less than 5.1 dl / g, not only the appearance performance of the instrument panel is lowered, but also the probability that (C) talc is incorporated into the ethylene / propylene copolymer increases, It is difficult to obtain the high heat distortion resistance. In addition, if the intrinsic viscosity IV exceeds 10 dl / g, the impact resistance of the instrument panel is lowered, and further, gel is generated on the surface of the molded product, thereby reducing the quality of the instrument panel.
Here, the intrinsic viscosity IV of the ethylene / propylene copolymer is a value measured in tetralin at 135 ° C., and specifically, measured using a capillary viscometer.

The ethylene content of the ethylene / propylene copolymer is 30 to 55% by mass, preferably 40 to 45% by mass. When the ethylene content exceeds 55% by mass, the compatibility between the ethylene / propylene copolymer and the crystalline homopolypropylene polymerized in the first stage is lowered, and the impact strength improvement effect of the instrument panel becomes poor. . On the other hand, when the ethylene content is less than 30% by mass, the compatibility is excessively increased and the rigidity of the instrument panel is lowered.
Here, the ethylene content of the ethylene / propylene copolymer is specifically calculated by statistical analysis of ¹³ C-NMR of the ethylene / propylene copolymer.

  Content of an ethylene propylene copolymer is 3-15 mass% in (A) polypropylene resin (100 mass%), Preferably it is 5-10 mass%. If the content of the ethylene / propylene copolymer is less than 3% by mass, the impact resistance of the instrument panel will not be sufficiently exhibited, so the amount of (B) ethylene copolymer rubber described later must be increased. However, this is not practical because it results in an increase in cost. On the other hand, if the content of the ethylene / propylene copolymer exceeds 15% by mass, the heat distortion resistance of the instrument panel is lowered, and the gel is liable to be generated on the surface, thereby deteriorating the quality of the instrument panel. .

(A) The intrinsic viscosity IV of the ethylene / butene copolymer contained in the polypropylene resin is 2.0 to 5.0 dl / g. When the intrinsic viscosity IV is less than 2.0 dl / g, not only the appearance performance of the instrument panel is lowered, but also the probability that (C) talc is incorporated into the ethylene / butene copolymer is increased, and the present invention is characterized. It is difficult to obtain the high heat distortion resistance. On the other hand, if the intrinsic viscosity IV exceeds 5.0 dl / g, the impact resistance of the instrument panel is lowered.
Here, the intrinsic viscosity IV of the ethylene / butene copolymer is a value measured in tetralin at 135 ° C., and specifically, measured using a capillary viscometer.

The ethylene content of the ethylene / butene copolymer is 60 to 80% by mass, preferably 70 to 80% by mass. When the ethylene content exceeds 80% by mass, the compatibility between the ethylene / butene copolymer and the crystalline homopolypropylene polymerized in the first stage is lowered, and the impact strength improvement effect of the instrument panel becomes poor. . On the other hand, when the ethylene content is less than 60% by mass, the compatibility is excessively increased and the rigidity of the instrument panel is lowered.
Here, the ethylene content of the ethylene / butene copolymer is specifically calculated by statistical analysis of ¹³ C-NMR of the ethylene / butene copolymer.

  Content of an ethylene butene copolymer is 5-25 mass% in (A) polypropylene resin (100 mass%), Preferably it is 10-20 mass%. If the content of the ethylene / butene copolymer is less than 5% by mass, the impact resistance of the instrument panel will not be sufficiently developed, so it is necessary to add a large amount of (B) ethylene copolymer rubber described later. However, this results in increased costs and is not realistic. On the other hand, if the content of the ethylene / butene copolymer exceeds 25% by mass, the rigidity and heat distortion resistance of the instrument panel are lowered.

<(B) Ethylene copolymer rubber>
In the present invention, in view of obtaining an instrument panel having good impact resistance, heat distortion resistance and low glossiness, (B) ethylene copolymer rubber is further blended with (A) polypropylene resin. It is preferable to do.
Examples of the ethylene copolymer rubber include ethylene / propylene copolymer elastomer, ethylene / 1-butene copolymer elastomer, ethylene / 1-hexene copolymer elastomer, ethylene / 1-octene copolymer elastomer. Olefin-based elastomers such as ethylene / propylene / diene copolymer elastomers; hydrogenated styrene-based elastomers such as styrene / butadiene copolymer elastomers, styrene / butadiene / styrene copolymer elastomers, and styrene / isoprene / styrene copolymer elastomers Examples of the added copolymer include styrene / ethylene / butylene / styrene copolymer elastomers. These may be used alone or in combination of two or more.
Among these, an ethylene / propylene copolymer elastomer, an ethylene / 1-butene copolymer elastomer, and an ethylene / 1-octene copolymer elastomer are preferable, and an ethylene / 1-octene copolymer elastomer is more preferable.

(B) The melt flow rate (MFR) of the ethylene copolymer rubber is not particularly limited, but is preferably 0.1 to 30 g / 10 minutes, and more preferably 0.5 to 20 g / 10 minutes. (B) If the MFR of the ethylene copolymer rubber is less than 0.1 g / 10 minutes, uniform dispersion in the composition (A + B + C) may be difficult. On the other hand, if the MFR of the (B) ethylene copolymer rubber exceeds 30 g / 10 minutes, the impact strength of the instrument panel may not be sufficiently improved.
Here, the MFR of (B) ethylene copolymer rubber is specifically measured under the conditions of 230 ° C. and 2.16 kg load according to JIS K7210.

  Taking into account that the blending amount of the (B) ethylene copolymer rubber imparts good impact resistance, heat distortion resistance and low glossiness within a practical cost range, the composition (A + B + C) (100 mass) %) Is preferably 10% by mass or less. Moreover, the blending amount of the (B) ethylene copolymer rubber is more preferably 5 to 8% by mass in order to impart sufficient impact resistance, heat distortion resistance and low gloss to the instrument panel.

<(C) Talc>
The (C) talc in the present invention is not particularly limited, but the (C) talc is particularly preferably an average particle diameter of 0.10 to 4.0 μm, and an average particle diameter of 0.20 to 3.0 μm. Is more preferable. When the average particle diameter of (C) talc is less than 0.10 μm, (C) talc causes secondary aggregation during kneading, which may reduce the mechanical properties of the instrument panel. On the other hand, if the average particle size of (C) talc exceeds 4.0 μm, the mechanical properties, particularly impact resistance, of the instrument panel may be reduced.

  (C) The amount of talc blended is as light as possible, and the polypropylene resin composition used in the present invention in consideration of obtaining an instrument panel having good heat distortion resistance, rigidity, and impact resistance. In the product (A + B + C) (100 mass%), it is 10 mass% to 30 mass%, preferably 15 mass% to 25 mass%.

<(D) Rosin nucleating agent>
The (D) rosin nucleating agent in the present invention comprises a rosin acid partial metal salt which is a reaction product of rosin acid and a metal compound. (D) As the rosin-based nucleating agent, calcium salts are particularly preferable from the viewpoint of the thermal stability of the composition. Although it does not specifically limit as rosin acid, Dehydroabietic acid, dihydroabietic acid, dihydropimalic acid, etc. are preferable.

  The blending amount of (D) rosin nucleating agent is 0.01-1 with respect to 100 parts by mass of (A) polypropylene resin, (B) ethylene copolymer rubber and (C) talc composition (A + B + C). 0.0 part by mass. (D) If the blending amount of the rosin-based nucleating agent is less than 0.01 parts by mass, the effect of improving the heat distortion resistance and rigidity of the instrument panel cannot be obtained. On the other hand, when the blending amount of the (D) rosin-based nucleating agent exceeds 1.0 part by mass, not only the improvement effect is saturated and the loss increases, but also the impact resistance of the instrument panel decreases, coloring, etc. It tends to deteriorate the appearance.

<Polypropylene resin composition>
The polypropylene resin composition in the present invention comprises (A) polypropylene resin, (C) talc and (D) rosin nucleating agent as essential components, and (B) ethylene copolymer rubber as necessary. It is.

  The polypropylene resin composition further includes, for example, calcium carbonate, clay, silica, magnesium carbonate, barium sulfate, aluminum hydroxide, magnesium hydroxide, wollastonite, magnesium oxysulfate as long as the effects of the present invention are not impaired. , Inorganic fillers such as fibrous potassium titanate, organic fillers such as wood powder, rice husk powder, cellulose, antioxidants, hydrochloric acid absorbents, heat stabilizers, light stabilizers, lubricants, antistatic agents, mold release agents Additives such as foaming agents, pigments, dyes, dispersants, copper damage inhibitors, flame retardants, ultraviolet absorbers, plasticizers, decomposition agents, impact resistance improvers such as thermoplastic elastomers, and the like may be appropriately blended.

The polypropylene resin composition is obtained by melt-kneading (A) polypropylene resin, (C) talc and (D) rosin nucleating agent, and (B) ethylene copolymer rubber and other additives as necessary. Prepared.
As the melt-kneading method, a known method may be appropriately employed, and examples thereof include a method using a melt-kneader such as a single screw extruder, a twin screw extruder, a Banbury mixer, a kneader, and a roll.
Moreover, mixing of each component may be performed simultaneously and may be performed by dividing | segmenting. Examples of the method of split mixing include a method of preparing a talc highly filled master batch in which (A) a polypropylene resin is filled with (C) talc at a high concentration, and melt-kneading this and the remaining components. .

<Instrument panel>
FIG. 1 is a view showing an example of an instrument panel of the present invention. This instrument panel 1 is obtained by molding the above-described polypropylene resin composition into a desired shape by a generally adopted molding method.
As a molding method, for example, an injection molding method, a stamping method, an injection compression method, or the like can be employed.

The instrument panel of the present invention may be provided with a leather-like, pear-like pattern or the like on its surface in order to have design properties.
In addition, the instrument panel of the present invention is not limited to a single-layer molded article composed only of the above-described polypropylene resin composition. As another form of the instrument panel of the present invention, for example, a skin material bonded to the surface of a base material made of a polypropylene resin composition; a base material made of another material, a polypropylene resin composition A laminated body such as one having a layer made of a foam in addition to a layer made of a polypropylene resin composition can be exemplified.

  In the instrument panel of the present invention described above, the filler is added to the (A) polypropylene resin containing an ethylene / propylene copolymer and an ethylene / butene copolymer characterized by intrinsic viscosity IV and ethylene content. As a specific filler, that is, (C) talc is added, and as a nucleating agent, a specific nucleating agent, that is, a polypropylene resin composition to which (D) rosin-based nucleating agent is added is used. In addition, the impact resistance strength and appearance performance (low glossiness, etc.) are good.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.
In the examples and comparative examples, each physical property was measured as follows.
[Intrinsic viscosity IV]
The intrinsic viscosity IV was measured using a capillary viscometer at 135 ° C. in tetralin.
[Ethylene content]
The ethylene content was calculated by statistical analysis of ¹³ C-NMR measurement of the sample using JEOL's INM-GSX400. Here, the conditions for the ¹³ C-NMR measurement are as follows.
Measurement mode: proton decoupling method, pulse width: 8.0 μs, pulse repetition time: 3.0 s, integration number: 1000 times, measurement temperature: 120 ° C., internal standard: hexamethyldisiloxane, solvent: 1, 2, 4 -Trichlorobenzene / benzene-d6 (volume ratio 3/1), sample concentration: 0.1 g / ml.

[Melt flow rate (MFR)]
The MFR of the polypropylene resin composition was measured for the pellets under the conditions of 230 ° C. and 2.16 kg in accordance with ASTM D-1238.
[Flexural modulus (FM)]
The flexural modulus of the molded product made of the polypropylene resin composition was determined by performing a bending test under the following conditions in accordance with ASTM D-790.
Bending speed: 2 mm / min, measuring temperature: 23 ° C.

[Izod impact value (IZOD)]
The Izod impact value of a molded article made of a polypropylene resin composition was measured under the following conditions in accordance with ASTM D-256.
Measurement temperature: 23 ° C.
[Heat deformation temperature (HDT)]
The heat distortion temperature of the molded product made of the polypropylene resin composition was measured under the following conditions in accordance with ASTM D-648.
Load; 455 kPa and 1820 kPa.

[appearance]
A flat molded product with dimensions of 400 mm in length × 200 mm in width × 3 mm in thickness and with a leather-like surface is injection-molded at a resin temperature of 230 ° C. and a mold temperature of 40 ° C., and its appearance is observed with the naked eye. Judged.
○: No or almost no flow mark or gloss unevenness is observed on the surface of the molded product, and it is judged that it can be put to practical use.
X: Flow mark and gloss unevenness are observed on a part or the whole of the molded product surface, and it is judged that it cannot be put to practical use.

Each component used in the examples and comparative examples is shown below.
<(A) Polypropylene resin>
[Production of PP-1]
(Preparation of solid catalyst)
56.8 g of anhydrous magnesium chloride was completely added to 100 g of absolute ethanol, 500 ml of petroleum oil “CP15N” manufactured by Idemitsu Kosan Co., Ltd. and 500 ml of silicone oil “KF96” manufactured by Shin-Etsu Silicone Co., Ltd. at 120 ° C. under a nitrogen atmosphere. Dissolved. This mixture was stirred for 2 minutes at 120 ° C. and 5000 rpm using a TK homomixer manufactured by Tokushu Kika Kogyo Co., Ltd. While maintaining stirring, it was transferred into 2 liters of anhydrous heptane so as not to exceed 0 ° C. The obtained white solid was thoroughly washed with anhydrous heptane, vacuum-dried at room temperature, and partially deethanolated under a nitrogen stream. 30 g of the resulting spherical solid of MgCl ₂ .1.2C ₂ H ₅ OH was suspended in 200 ml of anhydrous heptane. While stirring at 0 ° C., 500 ml of titanium tetrachloride was added dropwise over 1 hour. Next, when heating was started and the temperature reached 40 ° C., 4.96 g of diisobutyl phthalate was added, and the temperature was raised to 100 ° C. in about 1 hour. After reacting at 100 ° C. for 2 hours, the solid portion was collected by hot filtration. Thereafter, 500 ml of titanium tetrachloride was added to the reaction product and stirred, followed by reaction at 120 ° C. for 1 hour. After completion of the reaction, the solid portion was again collected by hot filtration, and washed 7 times with 1.0 liter of hexane at 60 ° C. and 3 times with 1.0 liter of hexane at room temperature to obtain a solid catalyst. It was 2.36 mass% when the titanium content rate in the obtained solid catalyst component was measured.

(Preliminary polymerization)
Under a nitrogen atmosphere, 500 ml of n-heptane, 6.0 g of triethylaluminum, 0.99 g of cyclohexylmethyldimethoxysilane, and 10 g of the above polymerization catalyst were put into a 3 liter autoclave and stirred for 5 minutes at a temperature range of 0 to 5 ° C. did. Next, propylene was supplied into the autoclave so that 10 g of propylene per 1 g of the polymerization catalyst was polymerized, and prepolymerized at a temperature range of 0 to 5 ° C. for 1 hour. The obtained prepolymerized catalyst was washed with 500 ml of n-heptane three times and used for the following polymerization.

(Main polymerization)
(First stage: Production of homopolypropylene component)
In a nitrogen atmosphere, an autoclave with a stirrer having an internal volume of 60 liters was charged with 2.0 g of the prepolymerized solid catalyst prepared by the above method, 11.4 g of triethylaluminum, and 1.88 g of cyclohexylmethyldimethoxysilane, and then 18 kg of propylene and propylene. On the other hand, hydrogen was charged so as to be 18,000 molppm, and the temperature was raised to 70 ° C. to perform polymerization for 1 hour. After 1 hour, unreacted propylene was removed and the polymerization was terminated.

(Second stage: Production of ethylene / propylene copolymer component)
As described above, after the first stage polymerization is completed, the liquid propylene is removed, and the mixed gas of ethylene / propylene = 37/63 (mass ratio) at a temperature of 75 ° C. is 2.2 Nm ³ / hour, hydrogen is converted into ethylene Then, it was supplied so as to be 1,000 molppm with respect to the total amount of propylene and hydrogen, and polymerized for 30 minutes. After 40 minutes, the unreacted gas was removed and the polymerization was terminated.

(Third stage: Production of ethylene / butene copolymer component)
As described above, after the polymerization in the second stage is completed, the liquid propylene is removed, and at a temperature of 75 ° C., a mixed gas of ethylene / butene = 74/26 (mass ratio) 2.2 Nm ³ / hour, hydrogen is converted into ethylene. , Butene and hydrogen were fed to a total amount of 60,000 molppm and polymerized for 60 minutes. After 40 minutes, unreacted gas was removed to terminate the polymerization, and PP-1 was obtained.

The intrinsic viscosity IV, the ethylene content, and the content of each copolymer in PP-1 are shown below for the obtained ethylene / propylene copolymer and ethylene / butene copolymer in PP-1.
PP-1: Intrinsic viscosity IV (in 135 ° C. tetralin) is 5.7 dl / g, ethylene content is 9% by mass with ethylene content of 40% by mass, and intrinsic viscosity IV (in 135 ° C. in tetralin) ) Is 2.3 dl / g, and includes 15% by mass of an ethylene / butene copolymer having an ethylene content of 75% by mass, and a propylene-based block copolymer having an MFR of 23 g / 10 min.

<Other polypropylene resins>
[Production of PP-2]
PP-2 was produced in the same manner as PP-1 except that the third stage was performed as follows.
(3rd stage: Production of ethylene / propylene copolymer component)
After completion of the second stage polymerization, the liquid propylene was removed, and a mixed gas of ethylene / propylene = 68/32 (mass ratio) of 2.2 Nm ³ / hour at a temperature of 75 ° C., hydrogen, ethylene, propylene and hydrogen Was fed to 50,000 mol ppm with respect to the total amount, and polymerized for 60 minutes. After 40 minutes, the unreacted gas was removed and the polymerization was terminated to obtain PP-2.

About each ethylene-propylene copolymer in obtained PP-2, intrinsic viscosity IV, ethylene content, and content of each copolymer in PP-2 are shown below.
PP-2: 9% by mass of an ethylene / propylene copolymer having an intrinsic viscosity IV (in 135 ° C. tetralin) of 5.7 dl / g and an ethylene content of 40% by mass, and an intrinsic viscosity IV (in 135 ° C. tetralin) ) Is 2.1 dl / g, and the propylene-based block copolymer having an MFR of 23 g / 10 min, containing 15% by mass of an ethylene / propylene copolymer having an ethylene content of 70% by mass.

[Production of PP-3]
PP-3 was produced in the same manner as in the production of PP-1, except that the second and third stages were performed as follows.
(Second stage: Production of ethylene / propylene copolymer component)
After the completion of the first stage polymerization, the liquid propylene was removed, and the mixed gas of ethylene / propylene = 49/51 (mass ratio) at a temperature of 75 ° C., 2.2 Nm ³ / hour, hydrogen, ethylene, propylene and hydrogen The amount was 26,000 molppm based on the total amount, and polymerization was performed for 30 minutes. After 40 minutes, the unreacted gas was removed and the polymerization was terminated.

(3rd stage: Production of ethylene / propylene copolymer component)
After completion of the second stage polymerization, the liquid propylene was removed, and a mixed gas of ethylene / propylene = 68/32 (mass ratio) of 2.2 Nm ³ / hour at a temperature of 75 ° C., hydrogen, ethylene, propylene and hydrogen The total amount of 30,000 molppm was fed and polymerized for 60 minutes. After 40 minutes, the unreacted gas was removed and the polymerization was terminated to obtain PP-3.

About each ethylene-propylene copolymer in obtained PP-3, intrinsic viscosity IV, ethylene content, and content of each copolymer in PP-3 are shown below.
PP-3: Intrinsic viscosity IV (in 135 ° C. tetralin) is 3.0 dl / g, ethylene content is 50% by mass, ethylene / propylene copolymer 9% by mass, and intrinsic viscosity IV (in 135 ° C. tetralin) ) Is 3.0 dl / g, and a propylene-based block copolymer having an MFR of 23 g / 10 min, containing 15% by mass of an ethylene / propylene copolymer having an ethylene content of 70% by mass.

<(B) Ethylene copolymer rubber>
Ethylene / octene copolymer rubber having an ethylene content of 74% by mass and an MFR of 12 g / 10 min (DuPont Dow Elastomer Japan, Engage EG8200).
<(C) Talc>
Untreated talc with an average particle size of 2.8 μm (Hayashi Kasei Co., Ltd., Micron White # 5000S).

<(D) Rosin nucleating agent>
D-1: rosin acid partial calcium salt (Arakawa Chemical Industries, Pine Crystal KR-50M).
<Other nucleating agents>
D-2: 2,2′-methylenebis (4,6-di-t-butylphenyl) sodium phosphate (manufactured by Asahi Denka Kogyo Co., Ltd., Adeka Stub NA-11).
D-3: Hydroxy-di-paratert-butylaluminum benzoate (manufactured by Shell Japan, AL-PTBBA).

[Example 1]
75 parts by mass of a polypropylene resin (PP-1), 5 parts by mass of ethylene / octene copolymer rubber, 20 parts by mass of talc, and 0.2 parts by mass of the nucleating agent (D-1) are mixed, and further 100 parts by mass of this mixture. In contrast, 0.2 parts by mass of Irganox B225 (manufactured by Ciba Specialty Chemicals, antioxidant), 0.1 parts by mass of DHT-4A (manufactured by Kyowa Chemical), and mainly containing carbon black and titanium oxide 1.2 parts by weight of a gray dry pigment was added, and these were kneaded and granulated at a resin temperature of 220 ° C. with a twin-screw extruder to obtain a polypropylene resin composition. Each physical property was measured using this polypropylene resin composition. The results are shown in Table 1.

  Furthermore, this polypropylene resin composition was molded into an instrument panel as shown in FIG. 1 using an injection molding machine. The obtained instrument panel had high heat distortion resistance and rigidity, and had good impact strength and appearance.

[Example 2]
A polypropylene resin composition was obtained in the same manner as in Example 1 except that the amount of the nucleating agent (D-1) was changed from 0.2 parts by mass to 0.6 parts by mass. Each physical property was measured using this polypropylene resin composition. The results are shown in Table 1.
Further, this polypropylene resin composition was molded into an instrument panel as shown in FIG. The obtained instrument panel had high heat distortion resistance and rigidity, and had good impact strength and appearance.

[Example 3]
A polypropylene resin composition was obtained in the same manner as in Example 1 except that the amount of the polypropylene resin (PP-1) was changed from 75 parts by weight to 80 parts by weight and no ethylene-octene copolymer rubber was added. . Each physical property was measured using this polypropylene resin composition. The results are shown in Table 1.
Further, this polypropylene resin composition was molded into an instrument panel as shown in FIG. The obtained instrument panel had high heat distortion resistance and rigidity, and had good impact strength and appearance.

[Comparative Example 1]
A polypropylene resin composition was obtained in the same manner as in Example 1 except that the nucleating agent (D-1) was not added. Each physical property was measured using this polypropylene resin composition. The results are shown in Table 1.
Further, this polypropylene resin composition was molded into an instrument panel as shown in FIG. Since the obtained instrument panel did not contain a nucleating agent, the heat distortion resistance and rigidity were inferior.

[Comparative Example 2]
A polypropylene resin composition was obtained in the same manner as in Example 1 except that the nucleating agent (D-1) was changed to the nucleating agent (D-2). Each physical property was measured using this polypropylene resin composition. The results are shown in Table 1.
Further, this polypropylene resin composition was molded into an instrument panel as shown in FIG. The obtained instrument panel was inferior in impact resistance because the nucleating agent was not (D) rosin-based nucleating agent.

[Comparative Example 3]
A polypropylene resin composition was obtained in the same manner as in Example 1 except that the nucleating agent (D-1) was changed to the nucleating agent (D-3). Each physical property was measured using this polypropylene resin composition. The results are shown in Table 1.
Further, this polypropylene resin composition was molded into an instrument panel as shown in FIG. The obtained instrument panel was inferior in heat distortion resistance because the nucleating agent was not (D) rosin nucleating agent.

[Comparative Example 4]
A polypropylene resin composition was obtained in the same manner as in Example 1 except that the polypropylene resin (PP-1) was changed to the polypropylene resin (PP-2). Each physical property was measured using this polypropylene resin composition. The results are shown in Table 1.
Further, this polypropylene resin composition was molded into an instrument panel as shown in FIG. The obtained instrument panel was inferior in impact resistance because the polypropylene resin did not contain a specific ethylene / butene copolymer.

[Comparative Example 5]
A polypropylene resin composition was obtained in the same manner as in Example 1 except that the polypropylene resin (PP-1) was changed to the polypropylene resin (PP-3). Each physical property was measured using this polypropylene resin composition. The results are shown in Table 1.
Further, this polypropylene resin composition was molded into an instrument panel as shown in FIG. The obtained instrument panel was inferior in appearance because the polypropylene resin did not contain a specific ethylene / propylene copolymer and a specific ethylene / butene copolymer.

[Comparative Example 6]
A polypropylene resin composition was obtained in the same manner as in Example 3 except that the polypropylene resin (PP-1) was changed to the polypropylene resin (PP-3). Each physical property was measured using this polypropylene resin composition. The results are shown in Table 1.
Further, this polypropylene resin composition was molded into an instrument panel as shown in FIG. The obtained instrument panel was inferior in impact resistance and appearance because the polypropylene resin did not contain a specific ethylene / propylene copolymer and a specific ethylene / butene copolymer.

  The instrument panel of the present invention has higher heat distortion resistance and rigidity, and impact resistance and appearance performance (low glossiness) than an instrument panel molded using a conventional polypropylene resin composition. Etc.) is good.

It is the schematic which shows an example of the instrument panel of this invention.

Explanation of symbols

1 Instrument panel

Claims (2)

(A) The intrinsic viscosity IV (in 135 ° C. tetralin) is 5.1 to 10 dl / g, and the ethylene content is 3 to 15% by mass, and the ethylene content is 30 to 55% by mass. Polypropylene resin 60 having a viscosity IV (in 135 ° C. tetralin) of 2.0 to 5.0 dl / g and an ethylene / butene copolymer of 5 to 25% by mass with an ethylene content of 60 to 80% by mass. ˜80 mass%,
(B) ethylene copolymer rubber 0-10% by mass, and (C) a composition (A + B + C) comprising talc 10-30% by mass,
That a polypropylene resin composition containing 0.01 to 1.0 part by mass of (D) rosin-based nucleating agent is molded from 100 parts by mass of the composition (A + B + C). Characteristic instrument panel. The instrument panel according to claim 1, wherein the component (A) other than the ethylene-propylene copolymer and the ethylene-butene copolymer of the polypropylene resin is a homopolypropylene component.

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