JP2006219667A - Polypropylene block copolymer, its use, and polypropylene resin composition comprising said polypropylene block copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molded product appearance improver for a resin, which can regulate the appearance of a large-sized molded component by incorporating it in a small amount, and a polypropylene resin composition, using the appearance improver, which can develop a good appearance, for example, in automotive exterior components and has excellent moldability. <P>SOLUTION: The invention relates to the propylene block copolymer comprising a crystalline propylene polymer moiety and a propylene-ethylene random copolymer moiety. The intrinsic viscosity [η]<SB>homo</SB>of the crystalline propylene polymer moiety is not more than 1.2 dL/g. The propylene-ethylene random copolymer moiety has an ethylene content of 30-70 wt% and intrinsic viscosity [η]<SB>copoly</SB>of 2.5-7.0 dL/g and occupies 40-80 wt% of the whole propylene block copolymer. The whole propylene block copolymer has an MFR value of 0.1-10 g/10 min and a [η]<SB>copoly</SB>/[η]<SB>homo</SB>value of 2.5-10. The polypropylene resin composition contains the propylene block copolymer as the molded product appearance improver. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a propylene-based block copolymer having a broad molecular weight distribution comprising a high-fluidity crystalline propylene polymer portion and a high-molecular-weight and high-content propylene / ethylene random copolymer portion, and the propylene-based block A polypropylene resin composition excellent in appearance of a molded product obtained by blending a predetermined amount of a molded product appearance modifier for polypropylene resin containing a copolymer, and a predetermined amount of the molded product appearance modifier for polypropylene resin, and having a molding processability The present invention relates to a polypropylene-based resin composition that is excellent in flow mark characteristics at the time of molding and suitable for injection molded products such as automobile exterior parts.

Polypropylene resins are light in weight and excellent in recyclability, so demand for automotive parts is increasing. Specifically, a polypropylene resin composition in which an ethylene-based thermoplastic elastomer component such as an ethylene / propylene copolymer or an ethylene / butene copolymer and an inorganic filler such as talc are blended with a crystalline polypropylene resin. . And it has been proposed to improve moldability, mechanical properties, appearance, and the like by appropriately selecting a polypropylene resin, various elastomer components, and an inorganic filler according to the purpose.
In particular, it has been found that so-called “polymerization blends” are effective for increasing the dispersibility of ethylene-based thermoplastic elastomer components (particularly ethylene / propylene copolymers) in crystalline polypropylene resins. A crystalline propylene resin (hereinafter sometimes referred to as a crystalline component) is produced in the first step, and an ethylene / propylene random copolymer (hereinafter sometimes referred to as a rubber component) is continued in the second step. It is well known to those skilled in the art that it is effective to use a propylene / ethylene block copolymer (hereinafter sometimes referred to as ICP) obtained by production.

Recently, there has been a demand for a polypropylene resin composition capable of molding a thinner molded product in a shorter molding time. One of the means for solving this problem is a technique using a so-called “high flow material” in which the melt flow rate (MFR) of ICP is increased. Such a high fluidity material has improved moldability and a thin molded product can be obtained, but there is a problem that a flow mark is easily generated. A flow mark is a tiger-striped pattern that appears on the surface appearance of a molded product, and a molded product in which the flow mark is generated impairs the design as a product and the product value is significantly reduced.
The technique for improving the flow mark is disclosed in, for example, Patent Document 1, Patent Document 2, or Patent Document 3.

  In Patent Document 1, it is an object to provide a propylene-based resin composition having excellent balance between physical properties such as moldability, rigidity, and impact strength. Among these solutions, an ICP (component a) having an overall MFR of 10 to 130 g / 10 min and a rubber component weight average molecular weight of 200,000 to 1,000,000 is disclosed. Also disclosed is an ICP (component b) having an overall MFR different from this ICP of 0.1 to 8 g / 10 min and a rubber component weight average molecular weight of 300,000 to 900,000. Furthermore, in addition to these components a and b, a technique of blending an inorganic filler (component c), polyethylene (component d), and fatty acid amide or a derivative thereof (component e) at a specific ratio is also disclosed. However, Patent Document 1 relates to the relationship between the flowability of the crystalline propylene polymer portion, the viscosity ratio of the crystalline propylene polymer portion and the ethylene / propylene random copolymer portion, and the appearance of the molded product represented by the flow mark characteristics. There is no disclosure or suggestion.

In Patent Document 2, it is an object to provide a polypropylene-based resin composition that is less likely to cause flow marks when it is formed into a molded body, has less fluffing, and has an excellent appearance. As this solution, the intrinsic viscosity ^[η] _{A P} propylene homopolymer portion and the intrinsic viscosity ^[eta] of the propylene-ethylene random copolymer _{A EP} is less than 3.0 dl / g or less 1.3 dl / g A polypropylene resin (A) having a portion is disclosed. Further, a polypropylene resin composition is disclosed in which the resin A and ICP (resin B) having different physical properties from the resin A are blended at a specific ratio. However, in Patent Document 2, it is difficult to say that the flow mark has been improved to a satisfactory level, and mechanical properties and moldability are also sacrificed.

In Patent Document 3, it is an object to provide a polypropylene resin composition that expresses a good appearance and is excellent in molding processing. As a means for solving this problem, the use of a moldability modifier comprising ICP having specific physical properties is disclosed. Specifically, the MFR of the propylene homopolymer portion (crystal component) is 500 g / 10 min or more, the MFR of the entire ICP is 100 g / 10 min or more, and the die swell ratio is 1.2 to 2.5. ICP is disclosed. However, in Patent Document 3, it is difficult to say that the flow mark has been improved to a satisfactory level, and mechanical properties (particularly, low temperature impact strength) and moldability are sacrificed.
JP 2001-288331 A JP 2002-12734 A JP 2004-18647 A

The present invention has been made in view of the above known technology and its problems, and its purpose is to produce a propylene block that is less likely to cause flow marks in order to efficiently produce large molded parts such as bumpers with high quality. An object of the present invention is to provide a molded product appearance modifier for a polypropylene-based resin that can improve the appearance of a molded product by blending a small amount with a copolymer and a general-purpose resin component.
Furthermore, using the molded product appearance modifier, a polypropylene-based material that exhibits a good appearance suitable for automobile exterior parts such as bumpers, rocker moldings, side moldings and over fenders, and has excellent molding processability. The object is to provide a resin composition.

  As a result of intensive studies to solve the above problems, the present inventors have found that a highly fluid crystalline propylene polymer portion and a propylene / ethylene random copolymer having a high ethylene content, a high molecular weight, and a high content. It has been found that a propylene block copolymer having a polymer portion and a wide molecular weight distribution can be used as a molded product appearance modifier that can solve the above problems by blending a small amount with a general-purpose resin component. Completed.

That is, according to the first invention of the present invention, the propylene comprises a crystalline propylene polymer portion and a propylene / ethylene random copolymer portion, and satisfies the following requirements (a) to (d): A system block copolymer is provided.
(A) Intrinsic viscosity [η] _homo measured with decalin as a solvent at 135 ° C. of the crystalline propylene polymer portion is 1.2 dl / g or less. (B) The propylene / ethylene random copolymer portion is The ethylene content is 30 to 70% by weight, the intrinsic viscosity [η] _copolymer is 2.5 to 7.0 dl / g, and the proportion of the portion in the entire propylene-based block copolymer is 40 to 80% by weight. (C) The total melt flow rate of the propylene-based block copolymer is in the range of 0.1 to 10 g / 10 min. (D) Intrinsic viscosity [η] _{homo of the} crystalline propylene polymer portion the intrinsic viscosity _{[eta] copoly} ratio of propylene-ethylene random copolymer component _{([η] copoly / [η} ] homo) for the range of 2.5 to 10 That there

According to a second aspect of the present invention, the propylene comprises a crystalline propylene polymer portion and a propylene / ethylene random copolymer portion, and satisfies the following requirements (a) to (d): There is provided a molded article appearance modifier containing a system block copolymer as an active ingredient.
(A) Intrinsic viscosity [η] _homo measured with decalin as a solvent at 135 ° C. of the crystalline propylene polymer portion is 1.2 dl / g or less. (B) The propylene / ethylene random copolymer portion is The ethylene content is 30 to 70% by weight, the intrinsic viscosity [η] _copolymer is 2.5 to 7.0 dl / g, and the proportion of the portion in the entire propylene-based block copolymer is 40 to 80% by weight. (C) The total melt flow rate of the propylene-based block copolymer is in the range of 0.1 to 10 g / 10 min. (D) Intrinsic viscosity [η] _{homo of the} crystalline propylene polymer portion the intrinsic viscosity _{[eta] copoly} ratio of propylene-ethylene random copolymer component _{([η] copoly / [η} ] homo) for the range of 2.5 to 10 That there

  Moreover, according to the 3rd invention of this invention, it contains 100 weight part of polypropylene resin to-be-modified materials, and (A) molded product appearance modifier 1-25 weight part of 2nd invention. A characteristic polypropylene-based resin composition is provided.

  According to a fourth aspect of the present invention, in the third aspect, the polypropylene resin-modified material contains (B) a propylene-ethylene block copolymer. Things are provided.

According to the fifth aspect of the present invention, in the third aspect, the polypropylene resin-modified material is:
(B) Propylene-ethylene block copolymer 65 to 99% by weight, and (C) Inorganic filler 1 to 35% by weight.
There is provided a polypropylene resin composition characterized by being a polypropylene resin composition containing

According to the sixth invention of the present invention, in the third invention, the polypropylene resin-modified material is:
(B) propylene-ethylene block copolymer 65 to 99% by weight, and (D) ethylene elastomer or styrene elastomer 1 to 35% by weight.
There is provided a polypropylene resin composition characterized by being a polypropylene resin composition containing

According to the seventh invention of the present invention, in the third invention, the polypropylene resin-modified material is:
(B) 45 to 98% by weight of propylene-ethylene block copolymer,
(C) Inorganic filler 1 to 40% by weight and (D) Ethylene elastomer or styrene elastomer 1 to 40% by weight
There is provided a polypropylene resin composition characterized by being a polypropylene resin composition containing

  The propylene-based block copolymer of the present invention can be used as a molded product appearance modifier that can improve the molded appearance of a polypropylene resin composition with a small amount of addition without impairing physical properties and moldability. In addition, the polypropylene resin composition containing the polypropylene resin molded product appearance modifier is excellent in moldability and flow mark characteristics, and is particularly suitable as a material for large injection molded products such as automobile exterior parts. It is.

  The present invention relates to a propylene-based block copolymer comprising a crystalline propylene polymer portion and a propylene / ethylene random copolymer portion and having specific physical properties, a molded product appearance modifier containing the same, and the molded product appearance It is a polypropylene resin composition containing a modifier. This will be described in detail below.

[I] Propylene-based block copolymer Physical Properties of Propylene Block Copolymer The propylene block copolymer of the present invention comprises a crystalline propylene polymer portion (crystal component) and a propylene / ethylene random copolymer portion (rubber component). And the whole meets the following requirements (a) to (d).

(A) Intrinsic viscosity [η] _{homo of} crystalline polypropylene polymer part
The intrinsic viscosity [η] _homo of the crystalline polypropylene polymer part constituting the propylene-based block copolymer of the present invention is 1.2 dl / g or less, preferably 0.7 to 1.2 dl / g. More preferably, it is 0.9-1.1 dl / g. When [η] _homo exceeds 1.2 dl / g, the effect of improving the flow mark when a propylene-based block copolymer is added to a propylene-based resin or the like as a molded product appearance modifier is not preferable. On the other hand, if it is less than 0.7 dl / g, impact resistance tends to be inferior.
The intrinsic viscosity [η] _homo of the crystalline polypropylene polymer part is the polymerization of the propylene homopolymer part (however, even if a very small amount of comonomer such as 0.5% by weight or less is copolymerized so as not to lose crystallinity). It is the intrinsic viscosity when finished. The propylene homopolymer may be polymerized in a single stage or may be polymerized in multiple stages. Intrinsic viscosity [η] _homo is the intrinsic viscosity of the crystalline polypropylene polymer portion taken out from the final polymerization tank when performing multistage polymerization. In order to adjust the intrinsic viscosity, hydrogen can be added during polymerization to control and adjust the molecular weight.
Here, the intrinsic viscosity [η] _homo is a value measured by a method described later.

(B) Propylene / ethylene random copolymer portion (rubber component)
(B-1) Ethylene content in propylene / ethylene copolymer portion The ethylene content of the propylene / ethylene copolymer portion (rubber component) constituting the propylene-based block copolymer of the present invention is 30 to 70% by weight. Yes, preferably 30 to 60% by weight, particularly preferably 40 to 60% by weight. When the ethylene content is less than 30% by weight, the effect as a molded article appearance modifier is low (the flow mark appearance is not improved), and when it exceeds 70% by weight, the copolymer itself or the molded article appearance modifier is obtained. Since the modifier component tends not to be uniformly dispersed in the material to be reformed when the material added as an injection molding is injection molded, it is not preferable.
Here, the ethylene content in the propylene / ethylene random copolymer portion is a value measured by the method described later.

(B-2) propylene-ethylene intrinsic viscosity of the random copolymer portion _{[eta] copoly}
The intrinsic viscosity _{[eta] copoly} of the propylene-ethylene random copolymer portion (rubber component) is 2.5~7.0dl / g, preferably 3.0~7.0dl / g, particularly preferably 4.5 to 6.5 dl / g. [Η] When the _copolymer is less than 2.5 dl / g, the appearance of the flow mark is inferior when injection-molded with the additive added as a modifier, and when it exceeds 7.0 dl / g, the entire propylene-based block copolymer With the decrease in the MFR, there is a disadvantage that the molding processability of the resin composition is inferior when injection molding is performed.
Here, the intrinsic viscosity [eta] _copoly of the propylene-ethylene random copolymer portion is a value measured by the method described below.

(B-3) Proportion of propylene / ethylene random copolymer portion The proportion of the propylene / ethylene random copolymer portion (rubber component) in the entire propylene block copolymer is 40 to 80% by weight, preferably It is 45 to 75% by weight, more preferably 45 to 60% by weight. When the propylene / ethylene random copolymer portion is less than 40% by weight, the appearance of the flow mark is not sufficiently improved, and physical properties and moldability are deteriorated. If the amount exceeds 80% by weight, the copolymer itself or a material added as a modifier is injection-molded and is not uniformly dispersed in the material to be reformed.
Here, the ratio of the propylene / ethylene random copolymer portion (rubber component) is a value measured by the method described later.

(C) MFR
The MFR of the propylene-based block copolymer of the present invention is 0.1 to 10 g / 10 minutes, preferably 0.1 to 9 g / 10 minutes. If the MFR is less than 0.1 g / 10 min, the molding processability as a resin composition is inferior at the time of injection molding, and if it exceeds 10 g / 10 min, the improvement in the appearance of the flow mark becomes insufficient.
Here, MFR is a value measured at a temperature of 230 ° C. and a load of 21.18 N in accordance with JIS K7210.

(D) Intrinsic Viscosity Ratio Intrinsic Viscosity [η] of Crystalline Propylene Polymer Part Constructing Propylene-Based Block Copolymer of the Present Invention [η] Intrinsic Viscosity [η] of Propylene / Ethylene Random Copolymer Part (Rubber Component) with respect to _homo the ratio of the _{copoly ([η] copoly / [} η] homo) is 2.5 to 10, preferably 3 to 9, particularly preferably 4 to 8. When [η] _copy / [η] _homo is less than 2.5, the effect as a molded article appearance modifier is low (flow mark appearance is not improved), and when 10 is exceeded, the rubber component is poorly dispersed. This is not preferable because a gel is generated.

2. Method for Analyzing Physical Properties of Propylene Block Copolymer Ratio of propylene / ethylene random copolymer portion (rubber component) in the propylene block copolymer of the present invention (Wc), ethylene content in rubber component, intrinsic viscosity The following measurement is performed by the following procedure using the following apparatus and conditions.

(1) Analytical device to be used (i) Cross fractionation device CFC T-100 (abbreviated as CFC) manufactured by Dia Instruments Co., Ltd.
(Ii) Fourier transform infrared absorption spectrum analysis FT-IR, Perkin Elmer 1760X
A fixed wavelength infrared spectrophotometer attached as a CFC detector is removed and an FT-IR is connected instead, and this FT-IR is used as a detector. The transfer line from the outlet of the solution eluted from the CFC to the FT-IR is 1 m long, and the temperature is maintained at 140 ° C. throughout the measurement. The flow cell attached to the FT-IR has an optical path length of 1 mm and an optical path width of 5 mmφ, and the temperature is maintained at 140 ° C. throughout the measurement.
(Iii) Gel permeation chromatography (GPC)
The GPC column in the latter part of the CFC is used by connecting three AD806MS manufactured by Showa Denko KK in series.

(2) CFC measurement conditions (i) Solvent: orthodichlorobenzene (ODCB)
(Ii) Sample concentration: 4 mg / mL
(Iii) Injection volume: 0.4 mL
(Iv) Crystallization: The temperature is lowered from 140 ° C. to 40 ° C. over about 40 minutes.
(V) Sorting method:
The fractionation temperature at the time of temperature-raising elution fractionation is 40, 100, and 140 ° C., and the fraction is separated into three fractions in total. The elution ratio (unit weight%) of the component eluting at 40 ° C. or lower (fraction 1), the component eluting at 40 to 100 ° C. (fraction 2), and the component eluting at 100 to 140 ° C. (fraction 3) is W _40, is defined as _{W 100, W 140.} W ₄₀ + W ₁₀₀ + W ₁₄₀ = 100. Moreover, each fractionated fraction is automatically transported to the FT-IR analyzer as it is.
(Vi) Elution solvent flow rate: 1 mL / min

(3) Measurement conditions for FT-IR After elution of the sample solution from GPC at the latter stage of the CFC starts, FT-IR measurement is performed under the following conditions, and GPC-IR data is collected for each of the above-described fractions 1 to 3. .
(I) Detector: MCT
(Ii) Resolution: 8 cm ⁻¹
(Iii) Measurement interval: 0.2 minutes (12 seconds)
(Iv) Number of integrations per measurement: 15 times

(4) Post-treatment and analysis of measurement results The elution amount and molecular weight distribution of the components eluted at each temperature are obtained using the absorbance at 2945 cm ⁻¹ obtained by FT-IR as a chromatogram. The elution amount is normalized so that the total elution amount of each elution component is 100%. Conversion from the retention volume to the molecular weight is performed using a calibration curve prepared in advance with standard polystyrene.
Standard polystyrenes used are the following brands manufactured by Tosoh Corporation.
F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000.
A calibration curve is created by injecting 0.4 mL of a solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. The calibration curve uses a cubic equation obtained by approximation by the least square method. Conversion to molecular weight uses a general-purpose calibration curve with reference to “Size Exclusion Chromatography” written by Sadao Mori (Kyoritsu Shuppan). The following numerical values are used for the viscosity equation ([η] = K × M ^α ) used at that time.
(I) Calibration curve using standard polystyrene K = 0.000138, α = 0.70
(Ii) Sample measurement of propylene-based block copolymer K = 0.000103, α = 0.78
The ethylene content distribution (distribution of ethylene content along the molecular weight axis) of each eluted component is a ratio of the absorbance of 2956 cm ⁻¹ and the absorbance of 2927 cm ⁻¹ obtained by FT-IR, and is obtained by using polyethylene, polypropylene, or ¹³ Converted to ethylene content (% by weight) using a calibration curve prepared in advance using ethylene-propylene rubber (EPR) and mixtures thereof whose ethylene content is known by C-NMR measurement, etc. Ask.

(5) Propylene / ethylene random copolymer portion ratio (Wc)
The ratio (Wc) of the propylene / ethylene random copolymer portion in the propylene-based block copolymer in the present invention is theoretically defined by the following formula (I), and is determined by the following procedure.
Wc (% by weight) = W ₄₀ × A ₄₀ / B ₄₀ + W ₁₀₀ × A ₁₀₀ / B ₁₀₀ (I)
In the formula (I), W ₄₀ and W ₁₀₀ are elution ratios (unit:% by weight) in each of the above-described fractions, and A ₄₀ and A ₁₀₀ are actual values in the respective fractions corresponding to W ₄₀ and W _100. the average ethylene content of measurement (unit: wt%), B _40, B _100, the ethylene content of the propylene-ethylene random copolymer portion contained in each fraction (unit: wt%). A method for _obtaining A ₄₀ , A ₁₀₀ , B ₄₀ , and B ₁₀₀ will be described later.

The meaning of the formula (I) is as follows. That is, the first term on the right side of the formula (I) is a term for calculating the amount of the propylene / ethylene random copolymer portion contained in the fraction 1 (portion soluble at 40 ° C.). When fraction 1 contains only propylene / ethylene random copolymer and no propylene homopolymer, W ₄₀ contributes to the content of propylene / ethylene random copolymer portion derived from fraction 1 as it is in the whole However, since fraction 1 contains a small amount of components derived from propylene homopolymer (components with extremely low molecular weight and atactic polypropylene) in addition to components derived from propylene / ethylene random copolymer, this part has been corrected. There is a need to. Therefore, by multiplying W ₄₀ by A ₄₀ / B ₄₀ , the amount derived from the propylene / ethylene random copolymer component in fraction 1 is calculated. For example, when the average ethylene content (A ₄₀ ) of fraction 1 is 30% by weight and the ethylene content (B ₄₀ ) of the propylene / ethylene random copolymer contained in fraction 1 is 40% by weight, fraction 1 30/40 = 3/4 (i.e. 75% by weight) is derived from a propylene / ethylene random copolymer, and 1/4 is derived from a propylene homopolymer. Thus, the operation of multiplying A ₄₀ / B ₄₀ by the first term on the right side means that the contribution of the propylene / ethylene random copolymer is calculated from the weight% of fraction 1 (W ₄₀ ). The same applies to the second term on the right side. For each fraction, the contribution of the propylene / ethylene random copolymer is calculated and added to form the propylene / ethylene random copolymer partial content.

(I) As described above, the average ethylene contents corresponding to fractions 1 and 2 obtained by CFC measurement are A ₄₀ and A ₁₀₀ , respectively (unit is weight%). A method for obtaining the average ethylene content will be described later.

(Ii) The ethylene content corresponding to the peak position in the differential molecular weight distribution curve of fraction 1 is defined as B ₄₀ (unit is% by weight). Fraction 2 is considered to be substantially defined as B ₁₀₀ = 100 in the present invention because it is considered that the rubber part is completely eluted at 40 ° C. and cannot be defined with the same definition. B ₄₀ and B ₁₀₀ are the ethylene content of the propylene / ethylene random copolymer portion contained in each fraction, but it is practically impossible to obtain this value analytically. This is because there is no means for completely separating and fractionating the propylene homopolymer and the propylene / ethylene random copolymer mixed in the fraction. As a result of investigations using various model samples, B ₄₀ can explain the effect of improving material properties well by using the ethylene content corresponding to the peak position of the differential molecular weight distribution curve of fraction 1. all right. Further, B ₁₀₀ has crystallinity derived from ethylene chain, and the amount of propylene / ethylene random copolymer contained in these fractions is larger than the amount of propylene / ethylene random copolymer contained in fraction 1. For the reason of the relatively few points, approximating 100 is closer to the actual situation and hardly causes an error in calculation. Therefore, the analysis is performed with B ₁₀₀ = 100.

(Iii) For the above reason, the ratio (Wc) of the propylene / ethylene random copolymer portion is determined according to the following formula.
Wc _{(wt%) = W 40 × A 40} / B 40 + W 100 × A 100/100 ... (II)
That is, W ₄₀ × A ₄₀ / B ₄₀ which is the first term on the right side of the formula (II) indicates the content (% by weight) of propylene / ethylene random copolymer having no crystallinity, and W ₁₀₀ which is the second term. × _a 100/100 indicates the propylene-ethylene random copolymer portion content with crystalline (wt%).
_Here, the average ethylene content _A 40 of _{B 40} and each of the fractions obtained by the CFC measurement 1 and _{2, A 100} is determined as follows.
Ethylene content corresponding to the peak position of the differential molecular weight distribution curve is B _40. In addition, the sum of the products of the weight ratio for each data point and the ethylene content for each data point, which is captured as data points at the time of measurement, is the average ethylene content A _{40 of} fraction 1. The average ethylene content A _{100 of} fraction 2 is determined in the same manner.

The significance of setting the three types of fractionation temperatures is as follows. In the CFC analysis of the present invention, polymers having no crystallinity at 40 ° C. (for example, most of propylene / ethylene random copolymer, or extremely low molecular weight component and atactic component in propylene homopolymer portion) ) Only is necessary and sufficient temperature fractionation. 100 ° C. means a component that is insoluble at 40 ° C. but becomes soluble at 100 ° C. (for example, a component having crystallinity due to a chain of ethylene and / or propylene in a propylene / ethylene random copolymer, and a crystal The temperature is necessary and sufficient to elute only the propylene homopolymer having low properties. 140 ° C. means a component that is insoluble at 100 ° C. but becomes soluble at 140 ° C. (for example, a component having particularly high crystallinity in a propylene homopolymer, and an extremely high molecular weight in a propylene / ethylene random copolymer) The temperature is necessary and sufficient to elute only the component having extremely high ethylene crystallinity and recover the entire amount of the propylene-based block copolymer used for the analysis. W ₁₄₀ does not contain any propylene / ethylene random copolymer component, or even if it is present, it is extremely small and can be substantially ignored, so the ratio of propylene / ethylene random copolymer and propylene / ethylene random copolymer Excluded from the calculation of the ethylene content of the copolymer.

(6) Ethylene content of propylene / ethylene random copolymer portion The ethylene content of the propylene / ethylene random copolymer portion in the propylene-based block copolymer in the present invention is the value described above, and Desired.
Ethylene content (% by weight) of propylene / ethylene random copolymer portion = (W ₄₀ × A ₄₀ + W ₁₀₀ × A ₁₀₀ ) / Wc
However, Wc is the ratio (% by weight) of the propylene / ethylene random copolymer portion determined previously.

(7) intrinsic intrinsic viscosity of the crystalline propylene polymer portion in the propylene block copolymer and propylene-ethylene random copolymer portion in the measurement present invention viscosity _{[η] homo, [η]} copoly is Ubbelohde viscometer Is measured at a temperature of 135 ° C. using decalin as a solvent.
First, after the polymerization of the crystalline propylene polymer portion is completed, a part is sampled from the polymerization tank, and the intrinsic viscosity [η] _homo is measured. Next, after polymerizing the crystalline propylene polymer portion, the intrinsic viscosity [η] _F of the final polymer (F) obtained by polymerizing the propylene / ethylene random copolymer is measured. [Η] _copy is obtained from the following relationship.
[Η] _F = (100−Wc) / 100 × [η] _homo + Wc / 100 × [η] _copy

3. Propylene Block Copolymer Production Method The propylene block copolymer of the present invention is a reaction mixture of a crystalline propylene polymer portion and a propylene / ethylene random copolymer portion. This is obtained by a production process of polymerization of a propylene homopolymer portion (first stage) which is a crystalline propylene polymer portion and subsequent polymerization of a propylene / ethylene random copolymer portion (second stage). The crystalline propylene polymer is produced by a polymerization step of one stage or two or more stages (the reaction conditions in each stage are the same or different), and the propylene / ethylene random copolymer portion is also one stage or two or more stages (in each stage). The reaction conditions are the same or different. Accordingly, the entire production process of the propylene-based block copolymer of the present invention is a sequential multistage polymerization process of at least two stages.

  The catalyst used for the polymerization is not particularly limited, and is a so-called Ziegler comprising a combination of an organoaluminum compound component and a solid component essentially comprising a titanium atom, a magnesium atom, a halogen atom and an electron donating compound. Any known catalyst such as a Natta catalyst or a metallocene catalyst can be used. Since the rubber component having a higher intrinsic viscosity has a higher effect of improving the molding appearance when added as a modifier, a Ziegler-Natta catalyst is generally more preferred because it has less chain transfer during polymerization.

In the sequential multistage polymerization process of at least two stages, hydrogen is supplied as propylene and a chain transfer agent in the preceding polymerization process, and the temperature is 50 to 150 ° C., preferably 50 to 70 ° C. in the presence of the catalyst. Propylene homopolymerization is carried out under the condition of a partial pressure of 0.5 to 4.5 MPa, preferably 1.0 to 3.0 MPa to produce a crystalline propylene polymer portion.
At this time, since the intrinsic viscosity [η] _homo of the crystalline propylene polymer portion in the propylene-based block copolymer of the present invention needs to be 1.2 dl / g or less, depending on the process and the type of catalyst, It is necessary to control the [η] _homo by adjusting the hydrogen of the chain transfer agent to a relatively high concentration.
The propylene block copolymer of the present invention is characterized in that the proportion of the propylene / ethylene random copolymer portion (rubber component) is high. Therefore, in the polymerization of the rubber component in the latter stage, the conditions for suppressing the activity of the catalyst are preferred in the polymerization in the former stage, in which the polymerization temperature and propylene partial pressure are low, the polymerization time is short. It is.
The crystalline propylene polymer portion may be copolymerized with an α-olefin other than propylene as long as the effects of the present invention are not impaired.

Subsequently, in the latter polymerization step, propylene, ethylene and hydrogen are supplied, and in the presence of the catalyst (the catalyst used in the first step polymerization step), the temperature is 50 to 150 ° C., preferably 50 to 90 ° C. Propylene and ethylene are subjected to random copolymerization under the conditions of partial pressure of 0.3 to 4.5 MPa, preferably 0.5 to 3.5 MPa, to produce a propylene / ethylene random copolymer portion. As a final product, a propylene-based block copolymer is obtained.
The propylene / ethylene random copolymer portion may be copolymerized with α-olefin other than propylene and ethylene as long as the effects of the present invention are not impaired.

At this time, the intrinsic viscosity _{[eta] copoly} the 2.5~7.0dl / g of propylene-ethylene random copolymer portion in the propylene block copolymer of the present invention, the ratio of the intrinsic viscosity _{[η] copoly} / [η ] Since it is necessary to set _homo to 2.5 to 10, it is necessary to adjust [η] _copolymer by adjusting the hydrogen of the chain transfer agent to a relatively low concentration, although it depends on the type of process and catalyst.
Moreover, the ethylene content in the propylene / ethylene random copolymer portion (rubber component) in the propylene-based block copolymer of the present invention is maintained within a specific range. Therefore, it is necessary to control the ethylene content in the rubber by adjusting the ethylene concentration relative to the latter propylene concentration.
Further, since it is necessary to increase the content of the propylene / ethylene random copolymer portion (rubber component) in the propylene-based block copolymer of the present invention, conditions for increasing the activity of the catalyst (polymerization temperature) , Propylene and ethylene have high partial pressures and a long polymerization time). However, if the polymerization temperature is too high, the fluidity of the powder particles deteriorates. Therefore, a relatively low temperature is preferred in order to maintain the fluidity of the powder particles well.

  The polymerization may be any of batch, continuous, and semi-batch. The polymerization in the first stage polymerization step may be performed in the gas phase or liquid phase, and the polymerization after the second stage polymerization step may be performed. It is preferable to carry out in the phase or liquid phase, particularly in the gas phase, and the residence time of each stage is preferably 0.5 to 10 hours, preferably 1 to 5 hours.

  Further, for the purpose of imparting fluidity to the powder particles of the composition produced by the at least two sequential multi-stage polymerization processes, and when the copolymer is injection-molded, gel generation that is poor dispersion of rubber is generated. For the purpose of prevention, the active hydrogen-containing compound is added to the central metal atom in the solid component of the catalyst (titanium in the case of a Ziegler-Natta catalyst) after the polymerization in the former polymerization step, before the polymerization in the latter polymerization step or during the polymerization. It is preferable to add in an amount of 100 to 1000 times mol with respect to atoms) and 2 to 5 times mol with respect to the organoaluminum compound of the catalyst.

  Here, examples of the active hydrogen-containing compound include water, alcohols, phenols, aldehydes, carboxylic acids, acid amides, ammonia, amines, and the like.

[II] Polypropylene-based resin composition The polypropylene-based resin composition of the present invention uses the above-mentioned propylene-based block copolymer as a molded product appearance modifier, and a general-purpose polypropylene-based resin-modified material as a third component. It is a polypropylene resin composition that is excellent in the appearance of a molded product obtained by blending, and is a polypropylene resin composition that is improved in the appearance of a molded product mainly represented by flow mark characteristics.
Specifically, it can be expressed as a polypropylene resin composition of (A) a molded product appearance modifier containing the above propylene block copolymer as an active ingredient and a polypropylene resin modified material. Examples of the material to be modified include (B) a propylene-ethylene block copolymer, and if necessary, (C) an inorganic filler and / or (D) an ethylene-based elastomer or a styrene-based elastomer. The polypropylene resin composition to contain can be mentioned. Hereinafter, each component will be described in detail.

1. Each component (A) component of polypropylene resin composition: Molded article appearance modifier (A) Molded article appearance modifier used in the polypropylene resin composition of the present invention is the above-mentioned propylene block copolymer. Contains as an ingredient.
The content of the propylene block copolymer in the (A) molded product appearance modifier is preferably 20 to 100% by weight, more preferably, based on the total weight of the (A) molded product appearance modifier. Is 50 to 100% by weight, more preferably 70 to 100% by weight, and particularly preferably 100% by weight.
(A) The molded product appearance modifier may contain other components in addition to the propylene-based block copolymer. Examples of such other components include polyolefin resins such as polyethylene, polypropylene, modified polyethylene, and modified polypropylene, and thermoplastic resins other than polyolefin such as polyamide, polycarbonate, and polyester.

Component (B): Propylene-ethylene block copolymer The propylene-ethylene block copolymer (B) used in the polypropylene resin composition of the present invention includes a crystalline polypropylene polymer part (A unit part) and ethylene / propylene. A block copolymer containing a random copolymer part (B unit part) is preferred. The A unit is usually a crystalline polymer obtained by homopolymerization of propylene, and in some cases, by copolymerizing a small amount of other α-olefin with propylene, and preferably has a high density. The crystallinity of the A unit part is usually 90% or more, preferably 95 to 100% as an isotactic index (insoluble matter by boiling n-heptane extraction). If the crystallinity is small, the mechanical strength of the polypropylene resin (B), in particular, the bending elastic modulus is inferior.
On the other hand, the B unit is a rubbery component obtained by random copolymerization of propylene and ethylene.

  The A unit part is usually 50 to 95% by weight of the total polymerization amount, preferably 60 to 90% by weight, and the B unit part is usually 5 to 50% by weight, preferably 10 to 40% by weight of the total polymerization amount. It is adjusted to become. The A unit part does not elute at 100 ° C. or lower in the extraction with orthodichlorobenzene, but the B unit part elutes easily. Therefore, for the polymer after production, the composition of the propylene-ethylene block copolymer (B) can be determined by extraction analysis with the above-described orthodichlorobenzene.

The MFR of the propylene-ethylene block copolymer (B) used in the polypropylene resin composition of the present invention is preferably 10 to 200 g / 10 minutes, more preferably 15 to 150 g / 10 minutes. If the MFR is less than 10 g / 10 min, the moldability is inferior, and if it exceeds 200 g / 10 min, the impact resistance is lowered, which is not preferable.
Further, the die swell ratio of the component (B) is preferably 0.98 to 1.2, and more preferably 1.0 to 1.2. If the die swell ratio is less than 0.9, the moldability tends to deteriorate, and if it exceeds 1.2, it tends to be difficult to produce at a low cost in a general-purpose manufacturing process.
Furthermore, 3-7 are preferable and, as for Q value of (B) component, More preferably, it is 3.5-6.5. If the Q value is less than 3, molding processability and impact characteristics tend to be lowered, and if it exceeds 7, it tends to be difficult to produce at a low cost in a general-purpose production process.
In addition, MFR in (B) component is the value measured similarly to the said propylene-type block copolymer, Q value is a value calculated | required from the weight average molecular weight measured using GPC, and a number average molecular weight, The die swell ratio is a value obtained by the following method.
The temperature in the cylinder of the melt indexer is set to 190 ° C. The orifice has a length of 8.00 mm, a diameter of 1.00 mmφ, and L / D = 8. Also, place a graduated cylinder containing ethyl alcohol directly under the orifice (the distance between the orifice and the ethyl alcohol liquid surface is 20 ± 2 mm). In this state, the sample is put into the cylinder, and the load is adjusted so that the extrusion amount per minute becomes 0.10 ± 0.03 g. The extrudate after 6 to 7 minutes is dropped into ethanol and solidified before being collected. The maximum and minimum values of the diameter of the strand-shaped sample of the collected extrudate were measured at 3 locations, 1 cm from the top, 1 cm from the bottom, and the center. Ratio.

  For the production of the component (B), a method of polymerizing using a highly stereoregular catalyst is preferably used. Any conventionally known method can be employed as the polymerization method. In producing the component (B) having a large amount of propylene / ethylene random copolymer part (B unit part), the gas phase fluidized bed method is particularly preferable. Further, by newly adding an electron donor compound in the subsequent reaction, it is possible to avoid problems of adhesion and blockage and improve the operability of polymerization.

Component (C): Inorganic filler In the polypropylene resin composition of the present invention, an inorganic filler (C) can be blended as necessary. The component (C) is used for improving the flexural modulus of the polypropylene resin composition and reducing the linear expansion coefficient.
In the present invention, the inorganic filler (C) is not particularly limited in composition, shape and the like. Any commercially available polymer filler can be used.
Specifically, plate-like inorganic fillers such as talc, mica and montmorillonite, short fiber glass fibers, long fiber glass fibers, carbon fibers, aramid fibers, alumina fibers, boron fibers, zonorites and other fibrous inorganic fillers, titanium Potassium acid, magnesium oxysulfate, silicon nitride aluminum borate, basic magnesium sulfate, zinc oxide, wollastonite, acicular inorganic filler such as calcium carbonate, precipitated calcium carbonate, heavy calcium carbonate, magnesium carbonate Examples thereof include granular inorganic fillers such as balun-like inorganic fillers such as glass balloons. Among them, talc is particularly preferable from the viewpoint of physical properties and cost.

  Talc is a modified polyolefin, fatty acid, grafted with various organic titanate coupling agents, organic silane coupling agents, unsaturated carboxylic acids, or anhydrides for the purpose of improving adhesion or dispersibility with the polymer. You may use what was surface-treated with fatty acid metal salt, fatty acid ester, etc.

(D) Component: Ethylene-based elastomer or styrene-based elastomer In the polypropylene-based resin composition of the present invention, an ethylene-based elastomer or a styrene-based elastomer (D) can be blended as necessary. Specific examples of the ethylene elastomer or styrene elastomer (D) include, for example, ethylene / propylene copolymer elastomer (EPR), ethylene / butene copolymer elastomer (EBR), ethylene / hexene copolymer elastomer (EHR), ethylene Ethylene / α-olefin copolymer elastomers such as octene copolymer elastomer (EOR); ethylene / propylene / ethylidene norbornene copolymer elastomers, ethylene / propylene / butadiene copolymer elastomers, ethylene / propylene / isoprene copolymer elastomers, etc. Ethylene / α-olefin / diene terpolymer elastomer (EPDM); styrene / butadiene / styrene triblock (SBS), styrene / isoprene / styrene triblock ( Styrenic elastomers such as SIS), hydrogenated styrene / butadiene / styrene triblock (SEBS), and hydrogenated styrene / isoprene / styrene triblock (SEPS) can be used.
The hydrogenated styrene / butadiene / styrene triblock is usually abbreviated as SEBS because the polymer main chain is styrene-ethylene-butene-styrene when viewed in monomer units.
Moreover, these ethylene-type elastomer or styrene-type elastomer (D) can be used in mixture of 2 or more types.

  The ethylene / α-olefin copolymer elastomer is produced by polymerizing each monomer in the presence of a catalyst. Examples of the catalyst include titanium compounds such as titanium halide, organoaluminum-magnesium complexes such as alkylaluminum-magnesium complexes, so-called Ziegler-type catalysts such as alkylaluminum or alkylaluminum chloride, WO-91 / 04257, etc. The metallocene compound catalyst described in 1) can be used. As the polymerization method, polymerization can be performed by applying a production process such as a gas phase fluidized bed, a solution method, or a slurry method. Examples of commercially available products include ED series manufactured by JSR, Tafmer P series and Tuffmer A series manufactured by Mitsui Chemicals, Engage EG series manufactured by DuPont Dow, and Tuftech H series manufactured by Asahi Kasei. Can also be used in the present invention.

  Here, an outline of a method for producing a hydrogenated product (SEBS, SEPS) of a triblock copolymer in the styrene elastomer will be described. These triblock copolymers can be produced by a general anion living polymerization method. A method of sequentially polymerizing styrene, butadiene and styrene to produce a triblock, followed by hydrogenation (production of SEBS). And a method of first hydrogenating the triblock body using a coupling agent after producing a diblock copolymer of styrene-butadiene. Moreover, the hydrogenated product (SEPS) of a styrene-isoprene-styrene triblock body can be similarly manufactured by using isoprene instead of butadiene.

  The MFR (measured at 230 ° C., 2.16 kg load) of the ethylene elastomer or styrene elastomer (D) used in the polypropylene resin composition of the present invention is preferably 0.5 to 150 g / 10 minutes, more preferably 0. 0.7 to 150 g / 10 min, particularly preferably 0.7 to 80 g / 10 min. In consideration of the automotive exterior material which is the main use of the polypropylene resin composition having an excellent molded appearance according to the present invention, those having an MFR in the above range are particularly preferable.

(E) Additional component (optional component)
In the polypropylene resin composition of the present invention, in addition to the above components (A) to (D), other additional components (arbitrary components) may be added as long as the effects of the present invention are not significantly impaired. Can do. Such additional components (optional components) include phenolic and phosphorus antioxidants, hindered amines, benzophenones, benzotriazoles, weathering deterioration inhibitors, nucleating agents such as organoaluminum compounds and organophosphorus compounds, Examples thereof include dispersants represented by metal salts of stearic acid, and coloring substances such as quinacridone, perylene, phthalocyanine, titanium oxide, and carbon black.

2. Component Composition of Polypropylene Resin Composition The polypropylene resin composition of the present invention is obtained by combining the components (A) to (D). Typically, compositions of components (A) and (B), compositions of components (A), (B) and (C), compositions of components (A), (B) and (D), components (A), (B), (C) and (D) compositions, and further, component (E) is blended as necessary.

(1) Polypropylene resin composition comprising components (A) and (B) In the polypropylene resin composition comprising components (A) and (B), (A) the molded product appearance modifier is ( B) 1 to 25 parts by weight, preferably 2 to 20 parts by weight, more preferably 2 to 15 parts by weight, and particularly preferably 2 to 15 parts by weight with respect to 100 parts by weight of the ethylene / propylene block copolymer. 9 parts by weight, most preferably 3 to 7 parts by weight. (A) If the molded product appearance modifier is less than 1 part by weight, the molded appearance effect is inferior. Conversely, if it exceeds 25 parts by weight, the fluidity is lowered.

(2) Polypropylene resin composition comprising components (A), (B) and (C) In the polypropylene resin composition comprising components (A), (B) and (C), (A) molding The product appearance modifier is 1 to 25 parts by weight, preferably 2 to 20 parts by weight, more preferably 2 to 15 parts by weight with respect to 100 parts by weight of the total of components (B) and (C). Particularly preferably 2 to 9 parts by weight, and most preferably 3 to 7 parts by weight. The ratio of the component (B) and the component (C) to the entire polypropylene resin-modified material is such that the component (B) is 65 to 99% by weight, preferably 70 to 98% by weight, more preferably 75 to 98% by weight, particularly preferably 80 to 97% by weight, and component (C) is 1 to 35% by weight, preferably 2 to 30% by weight, more preferably 2 to 25% by weight, particularly preferably 3 to 20%. % By weight. If the component (C) is less than 1% by weight, the effect of addition is not sufficiently exhibited and the flexural modulus is insufficient. Conversely, if it exceeds 35% by weight, the embrittlement temperature deteriorates and the moldability also decreases.

(3) Polypropylene resin composition comprising components (A), (B) and (D) In the polypropylene resin composition comprising components (A), (B) and (D), (A) molding The product appearance modifier is 1 to 25 parts by weight, preferably 2 to 20 parts by weight, more preferably 2 to 15 parts by weight with respect to 100 parts by weight of the total of components (B) and (D). Particularly preferably 2 to 9 parts by weight, and most preferably 3 to 7 parts by weight. The ratio of the component (B) and the component (D) to the entire polypropylene resin-modified material is such that the component (B) is 65 to 99% by weight, preferably 70 to 98% by weight, more preferably 75 to 98% by weight, particularly preferably 83 to 97% by weight, and component (D) is 1 to 35% by weight, preferably 2 to 30% by weight, more preferably 2 to 25% by weight, particularly preferably 3 to 17%. % By weight. When the component (D) is less than 1% by weight, the effect of addition is not sufficiently exhibited. On the other hand, when the component (D) exceeds 35% by weight, there is a concern about rigidity reduction, and there is a problem in cost. However, depending on the purpose and application, there are various blends, and depending on the type of elastomer, it is not limited to the above, but it is also important to select according to the application and purpose

(4) Polypropylene resin composition comprising components (A), (B), (C) and (D) To a polypropylene resin composition comprising components (A), (B), (C) and (D) In this case, (A) the molded article appearance modifier is 1 to 25 parts by weight, preferably 2 to 20 parts by weight, based on 100 parts by weight of the total of components (B), (C) and (D). Parts, more preferably 2 to 15 parts by weight, particularly preferably 2 to 9 parts by weight, and most preferably 3 to 7 parts by weight. The ratio of the component (B), the component (C), and the component (D) with respect to the entire polypropylene resin-modified material is such that the component (B) is 45 to 98% by weight, preferably 47 to 96% by weight, More preferably, it is 50 to 92% by weight, component (C) is 1 to 40% by weight, preferably 2 to 35% by weight, more preferably 4 to 32% by weight, and component (D) is 1 to 40% by weight. It is 40% by weight, preferably 2 to 35% by weight, more preferably 4 to 32% by weight.

3. Production of Polypropylene Resin Composition Production of the polypropylene resin composition of the present invention is carried out by mixing the above components at the above ratios, or extruders such as a single screw extruder or twin screw extruder, a Banbury mixer, It can be produced by kneading at a preset temperature of 180 ° C. to 250 ° C. using a normal kneader such as a roll, a Brabender plastograph, a kneader. Among these kneaders, it is preferable to produce using an extruder, particularly a twin screw extruder.

4). Molding of Polypropylene Resin Composition The polypropylene resin composition of the present invention is processed into a desired molded product. The molding method is not particularly limited, and can be molded by various molding methods depending on the purpose. For example, an injection molding method, an extrusion molding method, and the like can be applied. However, when applied to a large injection molding method, the molding processability, flow mark characteristics, weld appearance, etc. are excellent, and the effect is great. Therefore, it is suitable for automotive exterior parts such as bumpers, rocker moldings, side moldings and over fenders.

Examples The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds that.
In addition, the physical-property measuring method used in the Example and the manufacture example of used resin are as follows.

1. Physical property measurement method (1) Melt flow rate (MFR): Based on ASTM-D1238, it was measured at a temperature of 230 ° C. under a load of 2.16 kg.
(2) Izod impact strength: Measured with a notch at a temperature of −30 ° C. according to JIS-K7110, and judged according to the following criteria.
○: Equivalent to the material to be modified ×: 10% or more lower than the material to be modified (3) Appearance of molded product: An injection molding machine with a clamping pressure of 170 tons and a mold with a film gate with a width of 2 mm Using, a molding sheet of 350 mm × 100 mm × 2 mmt was injection molded at a molding temperature of 220 ° C. The occurrence of the flow mark was visually observed, the distance from the gate to the portion where the flow mark was generated was measured, and judged according to the following criteria.
○: Generation distance exceeds 200 mm ×: Generation distance is 200 mm or less

2. Propylene block copolymer (A)
The propylene-based block copolymers produced in Production Examples 1 to 9 below were used as (Modifier-1) to (Modifier-9). Table 1 shows the reaction conditions of each polymerization step, and various physical properties of the obtained crystalline propylene polymer and ethylene / propylene random copolymer.

(Production Example 1)
(I) Production of solid catalyst component (a) 20 liters of dehydrated and deoxygenated n-heptane was introduced into a tank equipped with a stirrer with an internal volume of 50 liters purged with nitrogen, then 10 moles of magnesium chloride and 20 moles of tetrabutoxytitanium And then reacting at 95 ° C. for 2 hours, lowering the temperature to 40 ° C., introducing 12 liters of methylhydropolysiloxane (viscosity 20 centistokes) and further reacting for 3 hours, then taking out the reaction solution The resulting solid component was washed with n-heptane.
Subsequently, 5 liters of dehydrated and deoxygenated n-heptane was introduced into the tank using the tank equipped with a stirrer, and then 3 mol of the solid component synthesized above was introduced in terms of magnesium atom. Next, 5 liters of silicon tetrachloride was mixed with 2.5 liters of n-heptane and introduced at 30 ° C. for 30 minutes. The temperature was raised to 70 ° C. and reacted for 3 hours. Then, the reaction solution was taken out, The resulting solid component was washed with n-heptane.

  Subsequently, 2.5 liters of dehydrated and deoxygenated n-heptane was introduced into the tank using the tank with a stirrer, and 0.3 mol of phthalic acid chloride was mixed and introduced at 90 ° C. for 30 minutes. And reacted at 95 ° C. for 1 hour. After completion of the reaction, washing with n-heptane was performed. Next, 2 liters of titanium tetrachloride was added at room temperature, and the temperature was raised to 100 ° C., followed by reaction for 2 hours. After completion of the reaction, washing with n-heptane was performed. Further, 0.6 liters of silicon tetrachloride and 8 liters of n-heptane were introduced, reacted at 90 ° C. for 1 hour, and sufficiently washed with n-heptane to obtain a solid component. This solid component contained 1.30% by weight of titanium.

Next, 8 liters of n-heptane, 400 g of the solid component obtained above, 0.27 mol of t-butyl-methyl-dimethoxysilane and 0.27 mol of vinyltrimethylsilane were introduced into the tank equipped with a stirrer substituted with nitrogen. And contacted at 30 ° C. for 1 hour. Next, the mixture was cooled to 15 ° C., 1.5 mol of triethylaluminum diluted in n-heptane was introduced over 15 minutes under 15 ° C., and after the introduction, the temperature was raised to 30 ° C. and reacted for 2 hours. The solid catalyst component (a) (390 g) was obtained by washing with heptane.
The obtained solid catalyst component (a) contained 1.22% by weight of titanium.
Furthermore, 6 liters of n-heptane and 1 mol of triisobutylaluminum diluted in n-heptane were introduced over 30 minutes at 15 ° C., and then about 0.4 kg / kg of propylene was controlled so as not to exceed 20 ° C. Preliminarily polymerized by introducing for 1 hour. As a result, a polypropylene-containing solid catalyst component (a) in which 0.9 g of propylene was polymerized per 1 g of solid was obtained.

(Ii) Production of propylene / ethylene block copolymer Polymerization was carried out using a continuous reaction apparatus in which two fluidized bed reactors having an internal volume of 230 liters were connected. First, in a first reactor, a polymerization temperature of 55 ° C., a propylene partial pressure of 18 kg / cm ² (absolute pressure), and hydrogen as a molecular weight control agent are continuously fed so that the molar ratio of hydrogen / propylene is 0.056. In addition, triethylaluminum was supplied at 5.25 g / hr as the solid catalyst component (a) so that the polymer polymerization rate was 14 kg / hr. The powder polymerized in the first reactor (crystalline propylene polymer) was continuously withdrawn so that the amount of powder held in the reactor was 40 kg and transferred continuously to the second reactor (pre-stage polymerization step). .

  Propylene and ethylene are continuously supplied so that the molar ratio of ethylene / propylene is 0.50 at a polymerization temperature of 80 ° C. and a pressure of 2.0 MPa. Further, hydrogen as a molecular weight control agent is While supplying continuously at a molar ratio of / propylene of 0.0013, ethyl alcohol was supplied as an active hydrogen compound so that the molar ratio was 2.1 times that of triethylaluminum. The powder polymerized in the second reactor is continuously withdrawn into the vessel so that the amount of powder held in the reactor is 50 kg, and the reaction is stopped by supplying moisture-containing nitrogen gas. A polymer was obtained (second-stage polymerization step). The resulting propylene / ethylene block copolymer was defined as (Modifier-1).

(Production Examples 2-4, 6-9)
Table 1 shows the amount of propylene and hydrogen in the preceding polymerization step, the amount of propylene and ethylene supplied and the amount of hydrogen in the subsequent polymerization step, the polymerization time in each step, and the polymerization temperature. Thus, propylene / ethylene block copolymers (Modifiers 2 to 4 and 6 to 9) were produced.

(Production Example 5)
After fully replacing the stainless steel autoclave with an internal volume of 200 liters with propylene gas, 60 liters of n-heptane, 5 g of the catalyst used in Production Example 1 and 15 g of triethylaluminum were added, the temperature was raised to 75 ° C., and 10 kg / hr of propylene was added. Was fed at a rate of 3.4 Hr. During this period, hydrogen was also continuously supplied so that the MFR was 160 g / 10 min. At this time, the pressure in the reactor was 0.55 MPa, but the supply of propylene and hydrogen was stopped, and the pressure in the reactor was lowered to 0.20 MPa over 30 minutes to complete the pre-stage polymerization step.
Next, the gas in the reactor is purged until the pressure in the reactor reaches 0.02 MPa, the hydrogen is removed, the temperature is changed to 65 ° C., 1.65 Kg / Hr of propylene, ethylene is changed in the presence of the pre-polymerization part. 1.3 Hr was supplied at a rate of 1.20 Kg / Hr. At this time, the pressure in the reactor was 0.03 MPa, and the reaction was terminated when the supply of propylene and ethylene was stopped and the pressure in the reactor became 0.02 MPa (second-stage polymerization step).
After 1.8 liters of butanol was added to the obtained block copolymer and the catalyst was decomposed at 70 ° C. for 3 hours, the catalyst was removed by washing with water. Further, a propylene / ethylene block copolymer (Modifier-5) was obtained through centrifugation and drying steps.

3. Ingredients (B)-(D)
As component (B) propylene-ethylene block copolymer, (PP-1) and (PP-2) shown in Table 2 and as component (C) inorganic filler (talc-1) and (talc- 2) (Elastomer-1) to (Elastomer-4) shown in Table 4 were used as component (D) ethylene elastomer or styrene elastomer.
In addition, the composition which consists of component (B)-(D) shown in Tables 2-4 is previously mix | blended in the ratio shown in Table 5, and also tetrakis [methylene-3- (3'5 ') as antioxidant. -Di-t-butyl-4'-hydroxyphenyl) propionate] methane (manufactured by Ciba Geigy, trade name: Irganox 1010) 0.1 part by weight, tris (2,4-di-t-butylphenyl) phosphite ( Ciba Geigy Co., Ltd., trade name: Irgafos 168) 0.05 part by weight was mixed and mixed for 5 minutes with a Henschel mixer, and then kneaded at a set temperature of 210 ° C. with a twin-screw kneader (Kobe Steel Co., Ltd .: 2FCM). It was granulated and used as the material to be modified (base material-1 to base material-8).

Example 1
As an antioxidant, tetrakis [methylene-3- (3′5′-di-t) is used as an antioxidant with respect to 100 parts by weight of a mixture of base material-1 (100 parts by weight) and modifier-1 (5 parts by weight). -Butyl-4'-hydroxyphenyl) propionate] Methane (manufactured by Ciba Geigy, trade name: Irganox 1010) 0.1 part by weight, tris (2,4-di-t-butylphenyl) phosphite (manufactured by Ciba Geigy) (Product name: Irgafos 168) Mix 0.05 parts by weight, mix for 5 minutes with a Henschel mixer, and knead and granulate with a twin-screw kneader (Kobe Steel Corporation: 2FCM) at a set temperature of 210 ° C. Thus, a polypropylene resin composition was obtained. The obtained polypropylene resin composition was evaluated for physical properties (MFR, flow mark generation distance, Izod impact strength at −30 ° C.). The evaluation results are shown in Table 6.

(Examples 2 to 10, Comparative Examples 1 to 14)
By blending the modifier shown in Table 1 and the base material shown in Table 5 at the ratio of the composition shown in Table 6, blending the antioxidant in the same manner as in Example 1, and kneading and granulating A polypropylene resin composition was obtained. The obtained polypropylene resin composition was evaluated for physical properties (MFR, flow mark generation distance, Izod impact strength at −30 ° C.). The evaluation results are shown in Table 6.

As is clear from Table 6, the polypropylene resin compositions (Examples 1 to 3, Examples 4, 5, 6, 7, 8, 9, 10) using the modifier of the present invention have the corresponding bases. Compared to the materials (Comparative Examples 4, 5, 6, 7, 8, 9, 10, 11, 12, 14), the flow mark generation distance is longer than 200 mm, the appearance of the molded product is improved, and the physical properties are affected. (Examples 1 to 10). In Comparative Example 13, although the flow mark generation distance was increased, gel was seen on the surface of the molded product. [Η] When _homo was large, the flow mark generation distance hardly increased (Comparative Example 1). When the propylene / ethylene content was low and the MFR was high, the flow mark generation distance slightly increased but was not sufficient, and the physical properties also decreased (Comparative Example 2). When [η] _copy was small, [η] _copy / [η] _homo was small, and MFR was high, the flow mark generation distance hardly increased (Comparative Example 3).

The propylene block copolymer of the present invention is a molded product that can control the moldability during injection molding and flow mark characteristics during molding of a polypropylene resin composition simply by blending with a general-purpose polypropylene resin. A polypropylene resin composition that can be used as an appearance modifier, and is blended with the polypropylene resin molded product appearance modifier, is excellent in molding processability and flow mark characteristics. In particular, bumper, rocker molding, side molding It is suitable for large injection molding of automobile exterior parts such as over fenders. Therefore, an improvement effect can be expected by adding an injection molded product such as an automobile exterior part currently used to a case where the molded appearance is a problem. In particular, as the globalization of economic activities progresses, there is a strong demand for resin materials that can solve the aforementioned problems in resin compositions based on general-purpose resins that are available anywhere in the world (main component). However, general-purpose molded article appearance modifying resins that are available anywhere in the world have a large amount of additive and have a large effect on physical properties. It becomes technology.

Claims (7)

A propylene-based block copolymer comprising a crystalline propylene polymer portion and a propylene / ethylene random copolymer portion and satisfying the following requirements (a) to (d).
(A) Intrinsic viscosity [η] _homo measured with decalin as a solvent at 135 ° C. of the crystalline propylene polymer portion is 1.2 dl / g or less. (B) The propylene / ethylene random copolymer portion is The ethylene content is 30 to 70% by weight, the intrinsic viscosity [η] _copolymer is 2.5 to 7.0 dl / g, and the proportion of the portion in the entire propylene-based block copolymer is 40 to 80% by weight. (C) The total melt flow rate of the propylene-based block copolymer is in the range of 0.1 to 10 g / 10 min. (D) Intrinsic viscosity [η] _{homo of the} crystalline propylene polymer portion the intrinsic viscosity _{[eta] copoly} ratio of propylene-ethylene random copolymer component _{([η] copoly / [η} ] homo) for the range of 2.5 to 10 That there Appearance of molded product comprising a propylene-based block copolymer comprising a crystalline propylene polymer portion and a propylene / ethylene random copolymer portion and satisfying the following requirements (a) to (d): Modifier.
(A) Intrinsic viscosity [η] _homo measured with decalin as a solvent at 135 ° C. of the crystalline propylene polymer portion is 1.2 dl / g or less. (B) The propylene / ethylene random copolymer portion is The ethylene content is 30 to 70% by weight, the intrinsic viscosity [η] _copolymer is 2.5 to 7.0 dl / g, and the proportion of the portion in the entire propylene-based block copolymer is 40 to 80% by weight. (C) The total melt flow rate of the propylene-based block copolymer is in the range of 0.1 to 10 g / 10 min. (D) Intrinsic viscosity [η] _{homo of the} crystalline propylene polymer portion the intrinsic viscosity _{[eta] copoly} ratio of propylene-ethylene random copolymer component _{([η] copoly / [η} ] homo) for the range of 2.5 to 10 That there   A polypropylene resin composition comprising 100 parts by weight of a polypropylene resin-modified material and 1 to 25 parts by weight of the (A) molded product appearance modifier according to claim 2.   The polypropylene resin composition according to claim 3, wherein the polypropylene resin-modified material contains (B) a propylene-ethylene block copolymer. Polypropylene resin modified material
(B) Propylene-ethylene block copolymer 65 to 99% by weight, and (C) Inorganic filler 1 to 35% by weight.
The polypropylene resin composition according to claim 3, which is a polypropylene resin composition containing Polypropylene resin modified material
(B) propylene-ethylene block copolymer 65 to 99% by weight, and (D) ethylene elastomer or styrene elastomer 1 to 35% by weight.
The polypropylene resin composition according to claim 3, which is a polypropylene resin composition containing Polypropylene resin modified material
(B) 45 to 98% by weight of propylene-ethylene block copolymer,
(C) Inorganic filler 1 to 40% by weight and (D) Ethylene elastomer or styrene elastomer 1 to 40% by weight
The polypropylene resin composition according to claim 3, which is a polypropylene resin composition containing