JP2009040950A - Molding modifier for polypropylene-based resin and polypropylene-based resin composition using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the appearance of molded articles by preventing the occurrence of flow marks of propylene-based resins. <P>SOLUTION: A molding modifier for polypropylene-based resin comprises a propylene-based block copolymer having ≥100 g/10 min MFR and composed of: a segment of a crystalline polypropylene polymer part (A) having ≥500 g/10 min MFR; and a segment of a propylene-ethylene random copolymer part (B) having ≤10<SP>-5</SP>g/10 min MFR. The polypropylene-based resin composition is obtained by blending the propylene-based block copolymer as a modifier with a propylene-based resin in the presence or absence of an elastomer or an inorganic filler. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a propylene / ethylene block copolymer having a high-fluidity propylene homopolymer part, a high-molecular-weight propylene / ethylene random copolymer part, and a moldability modification for polypropylene resin comprising the copolymer. When the injection molding is carried out by adding the agent and the polypropylene resin moldability modifier to the polypropylene resin, the molding processability is good, and the flow mark characteristics at the time of molding are excellent. The present invention relates to a polypropylene-based resin composition suitable for the injection molded product.

  Polypropylene resins are light in weight and excellent in recyclability, so demand for automotive parts is increasing. Specifically, a propylene / ethylene block copolymer composed of a crystalline polypropylene resin and a propylene / ethylene random copolymer is added to an ethylene-based thermoplastic elastomer component such as an ethylene / propylene copolymer or an ethylene / butene copolymer. Polypropylene resin compositions containing inorganic fillers such as talc are used. By appropriately selecting the polypropylene resin, various elastomer components, and inorganic fillers according to the purpose, moldability, mechanical properties, appearance, etc. It has been proposed to improve.

Recently, in order to more efficiently produce lighter vehicle parts, there is a demand for a higher-flow polypropylene resin that can form a thinner molded product in a shorter molding time. On the other hand, propylene / ethylene block copolymers for automobiles have recently been manufactured by a continuous gas phase method or a bulk-gas phase method which has a simple manufacturing process and can be manufactured at a low price. Most of the polypropylene produced by this process removes the heat of polymerization by the latent heat of propylene, and there is a problem that it is difficult to produce a high fluidity resin produced by supplying a large amount of hydrogen as an incompressible gas. In addition, the propylene / ethylene block copolymer produced by such a process generally tends to generate gels, so that a product having a high viscosity ratio between the crystalline polypropylene resin and the propylene / ethylene random copolymer is produced. There was a problem that it was difficult. In the case of a resin having a low viscosity ratio, there is a problem that a molding appearance defect such as a flow mark (tiger stripe-like pattern appearing on the surface appearance of the molded product) is likely to occur when a thin product is molded. Parts such as bumpers with a design where the painted part is exposed to the outside have a problem of impairing the design as a product.
The present inventors have developed a low-cost general-purpose propylene / ethylene block copolymer having a low fluidity and a low viscosity difference between the crystalline polypropylene component and the propylene / ethylene random copolymer component as a third component. We have developed a moldability modifier for polypropylene resins that can improve the appearance of molded products represented by fluidity and flow mark characteristics by adding a small amount, and has little influence on other physical properties.
In addition, the improvement technique of a flow mark is disclosed by patent document 1, patent document 2, and patent document 3, for example.

  In Patent Document 1, it is an object to provide a polypropylene-based resin composition that is less likely to cause flow marks when formed into a molded body, has less flaws, and has an excellent appearance. As a solution to this problem, the intrinsic viscosity [η] A polypropylene resin (A) having a propylene homopolymer portion having an AP of 1.3 dl / g or less and a propylene / ethylene random copolymer portion having an intrinsic viscosity [η] AEP of 3.0 dl / g or less; η] A polypropylene resin composition in which BEP is blended at a specific ratio of 8.0 dl / g to 15 dl / g is disclosed.

  Patent Document 2 discloses a method for producing a propylene / ethylene block copolymer having a propylene polymer MFR of 100 to 1000 g / 10 min and a propylene / ethylene copolymer of 5 to 10 wt% of the total weight.

  In Patent Document 3, it is an object to provide a polypropylene resin composition that expresses a good appearance and is excellent in molding. As a means for solving this problem, a propylene-ethylene block copolymer having specific physical properties is used. The use of moldability modifiers is disclosed. Specifically, the MFR of the propylene homopolymer portion (crystal component) is 500 g / 10 min or more, the MFR of the entire propylene-ethylene block copolymer is 100 g / 10 min or more, and the die swell ratio is 1.2. A propylene-ethylene block copolymer of ~ 2.5 is disclosed.

  In any method, the propylene homopolymer portion has a low-viscosity high MFR component, and the propylene / ethylene random copolymer portion has a high-viscosity component. The flow mark is improved by the improvement of fluidity due to the low shear stress caused by the high MFR propylene homopolymer part and the stabilization of the flow caused by the high normal stress caused by the high viscosity propylene / ethylene random copolymer part. It is believed that In particular, Patent Document 3 improves flow mark characteristics by blending into a general-purpose propylene / ethylene block copolymer as a third component.

  However, the resins disclosed in these prior art publications have an insufficient flow mark improving effect, and therefore there is a problem that the amount of blending needs to be increased in order to blend and control the appearance as the third component. It was.

  The reason is that the difference in viscosity between the propylene homopolymer and the propylene / ethylene random copolymer is insufficient. The reason why the viscosity disparity cannot be increased is that the hydrogen concentration of the chain transfer agent cannot be controlled during the production of propylene homopolymer and propylene / ethylene random copolymer, respectively. This is because a gel in which the propylene / ethylene random copolymer is not uniformly dispersed is formed in the homopolymer. Therefore, the MFR of the propylene homopolymer and the MFR of the propylene / ethylene random copolymer are limited.

  Patent document 4 is mentioned as resin which does not generate | occur | produce a gel and has sufficient flow mark improvement effect. In Patent Document 4, the component amount of the propylene / ethylene random copolymer is large and more than half, thereby preventing poor dispersion and gel. Specifically, propylene-ethylene random copolymer component (A) having an intrinsic viscosity [η] A measured in tetralin at 135 ° C. of 5 dl / g or more and an ethylene content of less than 8 to 20% by weight. A propylene-based polymer component obtained by polymerizing a monomer mainly composed of propylene having an intrinsic viscosity [η] B measured in tetralin at 135 ° C. of 51 to 75% by weight and 1.2 d / g or less (B) A propylene-based polymer comprising 25 to 49% by weight is disclosed.

However, the resin of this prior art publication has an extremely low MFR of the resin itself, and when blended as the third component, rather than improving the fluidity, the fluidity of the polypropylene resin composition after blending is extremely lowered. To do.

JP 2002-12734 A Japanese Patent Laid-Open No. 11-80298 JP 2004-18647 A JP-A-2005-146160

  The present invention has been made in view of the above-mentioned known technology and its problems, and by blending as a third component, moldability modification for polypropylene resin that can control the moldability and the appearance of the molded product. Another object is to provide a propylene-based block copolymer that can be used as an agent. A propylene-based resin composition that expresses a good appearance and is excellent in molding processability, suitable for automobile exterior parts and the like by blending the moldability modifier of the present invention, and an injection-molded product comprising the composition Can be provided.

  As a result of intensive studies to solve the above problems, the present inventors are composed of a propylene homopolymer portion of a specific MFR and a propylene / ethylene random copolymer portion having a specific MFR and ethylene content. It was found that by blending a propylene block copolymer with a small amount of polypropylene resin as a moldability modifier, the molding appearance characteristics and moldability of the polypropylene resin composition can be controlled, and the present invention was completed. It was.

That is, the gist of the present invention consists of a segment of a crystalline propylene polymer portion (A) and a segment of a propylene / ethylene random copolymer portion (B), and the MFR is 100 g / 10 min or more. (I) a propylene-based block copolymer (component (i)),
(A) MFR is 500 g / 10 min or more,
(B) MFR is 10 ⁻⁵ g / 10 min or less,
The ethylene content in (B) is 10 to 40% by weight
A block copolymer comprising:

  In addition, another aspect of the present invention is that the crystalline propylene polymer part (A) has a segment of 70 to 95% by weight and the propylene / ethylene random copolymer part (B) has a segment of 5 to 30% by weight. And (i) a moldability modifier for polypropylene resin comprising a propylene block copolymer.

  Another aspect of the present invention includes (i) 1 to 30 parts by weight of a moldability modifier comprising a propylene-based block copolymer, and (ii) a polypropylene-based resin (component (ii)) 70 to 70 The polypropylene-based resin composition having excellent molded appearance, comprising 99 parts by weight.

  Another aspect of the present invention is that (ii) the melt flow rate (JIS-K7210, temperature 230 ° C., load 21.18 N) of the polypropylene resin is 2 g / 10 min or more and less than 40 g / 10 min, A polypropylene resin composition having a ratio of 0.98 or more and less than 1.2 and a Q value of 3 or more and less than 7.

  Another aspect of the present invention is that (iii) an ethylene-based or styrene-based elastomer (i) is further added to 100 parts by weight of the total of (i) propylene-based block copolymer and (ii) polypropylene-based resin. The component (iii)) is blended in an amount of 1 to 40 parts by weight.

  Further, another aspect of the present invention is that (iv) an inorganic filler (component (iv) is further added to 100 parts by weight of the total of (i) propylene-based block copolymer and (ii) polypropylene-based resin. )) Is blended in an amount of 1 to 70 parts by weight.

  Another aspect of the present invention is that (iii) an ethylene-based or styrene-based elastomer has a melt flow rate (JIS-K7210, temperature 230 ° C., load 21.18 N) of 0.3 to 150 g / 10 min. The polypropylene resin composition is characterized by the following.

  Another gist of the present invention resides in (iv) a polypropylene resin composition characterized in that the inorganic filler is talc.

In addition, another aspect of the present invention is that a pre-stage polymerization step (a) for producing a crystalline propylene polymer portion (A) component and a propylene / ethylene random copolymer portion (B) component are produced. In the method for producing a propylene-based block copolymer by a semi-batch method comprising at least two steps including the latter polymerization step (b), the former polymerization step (a) supplies hydrogen and propylene into the reactor. In the presence of a catalyst, propylene is polymerized while reducing the hydrogen concentration relative to propylene over time, and when a crystalline propylene polymer is obtained, the gas concentration ratio of hydrogen to propylene in the unreacted gas ( H ₂ / C ₃ ) is maintained at 0.1 molar ratio or less, and in the subsequent polymerization step (b), the supply amount of propylene is decreased with time, and the supply amount of ethylene is not increased with time. (I) a method for producing a propylene-based block copolymer.

  The (i) propylene-based block copolymer of the present invention has a unique structure of having a high MFR propylene homopolymer and an extremely low MFR propylene / ethylene random copolymer. By blending this into the polypropylene resin for molding as the third component, it can be used as a so-called moldability modifier for polypropylene resins, which can prevent moldability during molding and molding appearance defects such as flow marks. The effect of this modifier is that it is manifested regardless of the presence of elastomers, inorganic fillers, and optional components. By using the moldability modifier of the present invention, it is possible to provide a propylene-based resin composition having a good appearance and excellent moldability that is suitable for automobile exterior parts and the like. In addition, the (i) propylene-based block copolymer of the present invention is industrially efficient and can be easily produced by a semi-batch method.

BEST MODE FOR CARRYING OUT THE INVENTION

(1) Propylene-based block copolymer (i) The propylene-based block copolymer of the present invention is a segment of a crystalline propylene polymer portion (A) having an MFR (melt flow rate) of 500 g / 10 min or more. The propylene / ethylene random copolymer part (B) has an ethylene content of 10 to 50% by weight, an MFR of 10 ⁻⁵ g / 10 min or less, and an MFR of 100 g / 10 min or more. Is a propylene-based block copolymer. The feature of this block copolymer is that the MFR of the segment of the crystalline propylene polymer portion (A) is 500 g / 10 min or more, so that the melt flow is very high and the flow in the mold is improved. On the other hand, the segment of the propylene / ethylene random copolymer portion (B) has a very low fluidity property such that the MFR is 10 ⁻⁵ g / 10 min or less.
A polymer that can be recognized as one propylene-based block copolymer is a polymer in which a segment having a very high value of MFR and a segment having a very low value of MFR are mixed, but the overall MFR is 100 g. It has been difficult to produce a copolymer having a segment with an extremely large difference in MFR, such as / 10 minutes or more, because of problems such as MFR control of both components and gel. The present inventors have now made it possible to produce by a novel polymerization method.

  In consideration of the polymerization process, the propylene block copolymer (i) of the present invention is obtained by polymerizing the crystalline propylene polymer portion (A) in the previous stage in advance, and then propylene. The operation of polymerizing the ethylene random copolymer portion (B) is performed. Therefore, it can be expected that there is a structure like a block copolymer in which both are bonded (real block), but actually, in addition to the so-called block copolymer, only the crystalline propylene polymer portion (A) Or a propylene / ethylene random copolymer portion (B) alone is considered to be mixed, but here, it is described as a propylene-based block copolymer from the practice of those skilled in the art.

  The (i) propylene-based block copolymer of the present invention is a so-called high molecular weight material that can be recognized as a high molecular weight substance. In order to clarify that the component (i) is usually a so-called high molecular substance, which is usually a high molecular substance, a molecular weight (Mn number average molecular weight or Mw weight average) which is usually used conventionally is used. It can also be indicated by molecular weight), degree of polymerization, viscosity display, etc. However, the component (i) of the present invention has a specific composition ratio having a crystalline propylene polymer portion (A) and a propylene / ethylene random copolymer portion (B), an arrangement order, and the like. In addition, in the present invention, the most typical polymer substance, which is the essential requirement that it must have in providing it to a molding material, is a so-called melt flow rate (which is one of the indicators of the characteristics of the polymer material). MFR) is adopted in key areas. In low molecular weight materials, there is little need for problems such as MFR behavior, but on the other hand, the specification of a polymer substance by MFR is rational in recognizing that component (i) is a polymer substance. In addition to functioning, it plays the role of solving the problem of moldability of polymer materials. Thus, the fact that MFR is employed for the specification of the invention of the component (i), which belongs to the category of polymer substances, not only properly expresses that it is a polymer substance, One of the indicators that solves the problem of flow characteristics in plasticization in the molding process unique to polymer materials meets the requirements for flow marks. In this sense, the fact that the high-molecular substance as component (i) has been specified by MFR not only functions very rationally, but also presents problems, configurations and significance as the high-molecular substance of the present invention. It plays the role of expressing sex appropriately.

(2) Moldability modifier for polypropylene resin The moldability modifier for polypropylene resin of the present invention includes a crystalline propylene polymer portion (A) excellent in fluidity and propylene / ethylene having an extremely low MFR. The significance was found by subjecting the (i) propylene-based block copolymer containing the random copolymer portion (B) to a specific application called a moldability modifier for polypropylene-based resins. (Ii) In order to improve the moldability of a polypropylene-based resin, (i) by blending a moldability modifier composed of a propylene-based block copolymer, the problem of moldability can be solved. It was made. Thus, the (i) propylene-based block copolymer composed of segments having a large difference in MFR exhibits the effect of improving moldability, such as (ii) the effect of improving the flow mark of the polypropylene-based resin. Such knowledge is also found in the prior art, but the effect was not sufficient.

The effect of such moldability modification is sufficient if (ii) 1 to 30 parts by weight of the propylene block copolymer is added to 100 parts by weight of the polypropylene resin. This means that a very small blending amount is sufficient based on the normal blend amount.
This characteristic is obtained by blending other additives such as (iii) elastomers, (iv) inorganic fillers, (v) various compounding agents composed of optional components (component (v)) into (ii) polypropylene resin. However, regardless of the presence / absence of the compounding agent and the increase / decrease of the compounding amount, an effect of good moldability is exhibited.

The crystalline propylene polymer portion (A) constituting the moldability modifier may be one-stage polymerization or multistage polymerization. The MFR is 500 g / 10 min or more, preferably 600 g / 10 min or more, and more preferably 700 g / 10 min or more. If the value falls below the lower limit, the fluidity is lowered, which is disadvantageous in that the effect of improving the flow mark due to the low shear stress cannot be obtained. Although there is no upper limit in particular, it determines by MFR of the polypropylene resin after mix | blending as a 3rd component, the influence balance on a physical property, etc.
The MFR of the crystalline propylene polymer portion is the MFR when the polymerization of the crystalline propylene polymer portion is finished. When performing multistage polymerization, the MFR of the crystalline propylene polymer portion taken out from the final polymerization tank is used. It is.
In the production of crystalline propylene polymer, only propylene is usually used as a monomer component to be polymerized, and a propylene homopolymer is produced. Can be used. Such monomers include α-olefins such as ethylene and butene. The amount used is less than 3% by weight, preferably less than 1% by weight, based on propylene.

The propylene / ethylene random copolymer portion (B) constituting the moldability modifier may be one-stage polymerization or multistage polymerization. Further, the MFR is 10 ⁻⁵ g / 10 min or less, preferably 5 × 10 ⁻⁶ g / 10 min or less, and more preferably 10 ⁻⁶ g / 10 min or less. If the upper limit is exceeded, the flow mark improvement effect due to the high normal stress cannot be obtained, which is inconvenient. Although there is no lower limit in particular, it is determined by the MFR of the polypropylene resin after blended as the third component, the effect on physical properties, etc.
The MFR of the propylene / ethylene random copolymer portion is the MFR when the polymerization of the propylene / ethylene random copolymer portion is finished. When the propylene / ethylene random copolymer portion is subjected to multistage polymerization, the final polymerization is performed. This is the MFR at the time of completion. Since the MFR of the propylene / ethylene random copolymer portion cannot be directly measured, MFR _A and MFR _B are measured and calculated by the following formula.
log (MFR _{A + B} ) = (100−Wc) / 100 × log (MFR _A ) + Wc / 100 × log (MFR _B )
Here, Wc is the ratio of the propylene / ethylene random copolymer portion (B) in the propylene-based block copolymer, and is determined by the method described later.
In addition, propylene / ethylene random copolymer usually uses only propylene and ethylene as monomer components to be polymerized to produce a propylene / ethylene random copolymer, but is small in the range not impairing the object of the present invention. Other copolymerizable monomer components can be used. Such monomers include α-olefins such as butene.

  The ethylene content of the propylene / ethylene random copolymer portion (B) is 10 to 50% by weight, preferably 12 to 40% by weight, and more preferably 15 to 30% by weight. If the upper limit is exceeded, the flow mark is easily noticeable, and conversely if the lower limit is exceeded, the impact resistance deteriorates, which is inconvenient.

  (I) The MFR of the propylene-based block copolymer (moldability modifier) is 100 g / 10 min or more, preferably 100 to 300 g / 10 min, more preferably 100 to 200 g / 10 min. On the contrary, if the lower limit is not reached, the MFR of the polypropylene resin after blending as the third component becomes too low, which is inconvenient because the moldability is lowered. Although there is no upper limit in particular, it determines by MFR of the polypropylene resin after mix | blending as a 3rd component, the influence balance on a physical property, etc.

  In the propylene block copolymer (i) according to the method of the present invention, the proportion of the crystalline propylene polymer portion (A) in the propylene block copolymer is 70 to 95% by weight, preferably 75. It is -93 weight%, More preferably, it is 80-90 weight%. The proportion of the propylene / ethylene random copolymer portion (B) is 5 to 30% by weight, preferably 7 to 25% by weight, and more preferably 10 to 20% by weight. If the proportion of the component (A) exceeds the upper limit (the proportion of the component (B) falls below the lower limit), a sufficient flow mark improving effect cannot be obtained, which is inconvenient. When the proportion of the component (A) falls below the lower limit (the proportion of the component (B) exceeds the upper limit), the MFR of the propylene-based block copolymer is lowered, and the polypropylene after blending as the third component The MFR of the resin is too low, which is inconvenient because it causes a decrease in moldability.

  The (i) propylene-based block copolymer according to the method of the present invention includes, as necessary, known ultraviolet absorbers, heat stabilizers, antioxidants and neutralizers, electrification used in conventional polyolefins. Inhibitors and weathering agents may be added.

  The (i) propylene-based block copolymer according to the method of the present invention can be produced by a semi-batch method using a single reactor. Hereinafter, a polymerization solvent, a polymerization catalyst and hydrogen are charged into a single reactor, and propylene and hydrogen are continuously supplied to produce a crystalline propylene polymer. The reactor gas is purged once, and then propylene and ethylene are continuously supplied. The production by a semi-batch method will be described in which a propylene / ethylene random copolymer is produced and taken out.

(I) Polymerization reactor The polymerization reactor is not particularly limited in shape and structure, but is generally used in a tank with a stirrer generally used in slurry polymerization and bulk polymerization, a tube reactor, and gas phase polymerization. Examples thereof include a fluidized bed reactor and a horizontal reactor having a stirring blade. In the polymerization method using a single reactor, polymerization is performed using one reactor selected from these throughout the polymerization process.

(Ii) Polymerization catalyst The polymerization catalyst used in the production method of the present invention must be present at the start of the polymerization, and must be involved in the polymerization from the beginning of the polymerization. Do not add. When a catalyst is newly added after the start of polymerization, the ratio of the propylene / ethylene random copolymer to the crystalline propylene polymer in the powder polymerized with the added catalyst is high, which causes deterioration of powder properties and gel generation. Further, as a result, the amount of catalyst input increases and the catalyst activity decreases, which is disadvantageous in terms of an increase in catalyst cost and an increase in catalyst residue in the polymer, and the effects of the present invention cannot be achieved.

  The kind of the polymerization catalyst used in the production method of the present invention is not particularly limited, and a known catalyst can be used. For example, a so-called Ziegler-Natta catalyst or a metallocene catalyst (for example, JP-A-5-295022) in which a titanium compound and organic aluminum are combined can be used. The higher the intrinsic viscosity of the rubber component, the higher the molding appearance improvement effect when added as a modifier, that is, the high viscosity propylene / ethylene random copolymer component has the effect of improving the flow mark. Therefore, in general, a Ziegler-Natta catalyst with less chain transfer during polymerization is more preferable. The Ziegler-Natta catalyst is a titanium trichloride or titanium trichloride composition obtained by reduction with organoaluminum as a titanium compound, which is further activated by treatment with an electron donating compound (for example, JP-A-47-34478, JP-A-58-23806, JP-A-63-146906), a so-called supported catalyst obtained by supporting titanium tetrachloride on a carrier such as magnesium chloride (for example, JP-A-58-157808, JP-A-58-58). 83006, JP 58-5310, JP 61-218606) and the like. As these catalysts, known catalysts can be used without any particular limitation.

  An organoaluminum compound is used as a cocatalyst. For example, trialkylaluminum such as trimethylaluminum, triethylaluminum and triisobutylaluminum, alkylaluminum halide such as diethylaluminum chloride and diisobutylaluminum chloride, alkylaluminum hydride such as diethylaluminum hydride, alkylaluminum alkoxide such as diethylaluminum ethoxide, methyl Examples include alumoxanes such as alumoxane and tetrabutylalumoxane, and complex organoaluminum compounds such as dibutyl methylboronate and lithium aluminum tetraethyl. It is also possible to use a mixture of two or more of these.

  In addition, various polymerization additives for the purpose of improving stereoregularity, controlling particle properties, controlling soluble components, controlling molecular weight distribution, and the like can be used in the above-described catalyst. For example, organic silicon compounds such as diphenyldimethoxysilane and tert-butylmethyldimethoxysilane, esters such as ethyl acetate, butyl benzoate, methyl p-toluate and dibutyl phthalate, ketones such as acetone and methyl isobutyl ketone, diethyl ether And electron donating compounds such as ethers such as benzoic acid and propionic acid, and alcohols such as ethanol and butanol.

(Iii) Polymerization mode and polymerization solvent As the polymerization mode, slurry polymerization using an inert hydrocarbon such as hexane, heptane, octane, benzene or toluene as a polymerization solvent, bulk polymerization using propylene itself as a polymerization solvent, or raw material propylene It is possible to perform gas phase polymerization in which the polymer is polymerized in a gas phase. Moreover, it is also possible to carry out by combining these polymerization formats.
For example, a method in which a crystalline propylene polymer is carried out by bulk polymerization and a propylene / ethylene random copolymer is produced by gas phase polymerization, or a crystalline propylene polymer is carried out by bulk polymerization followed by gas phase polymerization to produce propylene / ethylene random Examples of the copolymer include a method performed by gas phase polymerization.
In the present invention, the crystalline propylene polymer has a high hydrogen concentration due to its high MFR, and the propylene / ethylene random copolymer also has a relatively high ethylene concentration, so that propylene is difficult to liquefy and pressure is required for bulk polymerization. Need to be higher. Therefore, slurry polymerization and gas phase polymerization are preferable.

(Iv) Polymerization additive Although it depends on the combination with the catalyst, it is preferable to add the polymerization additive because the case where an aromatic ester such as butyl benzoate is added to the titanium trichloride catalyst consumes more hydrogen. .

(V) Polymerization pressure In the semi-batch polymerization, it is possible to carry out the polymerization pressure at a constant value or to change it at any time during the production of the crystalline propylene polymer. While setting the polymerization pressure high has the advantage of increasing the catalyst activity, it has the disadvantage of increasing the amount of unreacted propylene to be recovered, so it is carried out at 0.2 to 5 MPa, preferably about 0.3 to 2 MPa. preferable.
Further, at the time of producing the propylene / ethylene random copolymer, the polymerization pressure can be kept constant or can be changed as needed. In order to obtain the (i) propylene-based block copolymer of the present invention, it is preferable to carry out at about 0.1 to 0.2 MPa.

(Vi) Polymerization temperature Although this invention is not specifically limited regarding polymerization temperature, Usually, 20-100 degreeC, Preferably it selects from the range of 40-80 degreeC. This polymerization temperature may be the same or different at the start of polymerization and at the end of polymerization.

(Vii) Polymerization time In the method of the present invention, the polymerization time is not particularly limited, but is usually 30 minutes to 10 hours. In general, the production of crystalline propylene polymer takes 2 to 5 hours for gas phase polymerization, 30 minutes to 2 hours for bulk polymerization, and 4 to 8 hours for slurry polymerization. The standard is 1 to 3 hours for polymerization, 20 minutes to 1 hour for bulk polymerization, and 1 to 3 hours for slurry polymerization.

(Vii) Production of crystalline propylene polymer portion In the successive multistage polymerization step of at least two steps, propylene and hydrogen are supplied as a chain transfer agent in the previous polymerization step, and propylene alone in the presence of the catalyst. Polymerization is performed to produce a crystalline propylene polymer portion.
At this time, not only the MFR of the crystalline propylene polymer portion (A) in the propylene-based block copolymer (i) of the present invention is 500 g / 10 min or more, but also in the subsequent polymerization step to be carried out subsequently. -MFR of ethylene random copolymer part (B) needs to be 10 <^-5> or less. For this purpose, in the preceding polymerization step, hydrogen and propylene are supplied into the reactor, and in the presence of a catalyst, propylene is polymerized while the hydrogen concentration relative to propylene is lowered over time, and a crystalline propylene polymer is obtained. When obtained, it is necessary to maintain the gas concentration ratio (H ₂ / C ₃ ) between hydrogen and propylene in the unreacted gas at 0.1 molar ratio or less.

Examples of the method for controlling the gas concentration ratio (H ₂ / C ₃ ) of hydrogen and propylene in the unreacted gas at the end of the previous polymerization step include the following methods.
That is, as described above, in the semi-batch polymerization, the crystalline propylene polymer can be produced at a constant polymerization pressure or can be changed at any time, so that the gas concentration ratio between hydrogen and propylene in the unreacted gas ( H ₂ / C ₃ ) can be reduced by (i) a method in which the supply amount of propylene is kept constant and the supply amount of hydrogen is decreased, and (ii) a supply pressure of propylene is increased by keeping the polymerization pressure constant. And (iii) a method for decreasing the supply amount of both propylene and hydrogen, and (iv) a method for increasing the supply amount of both propylene and hydrogen. (Ii) A method of increasing the supply amount of propylene and decreasing the supply amount of hydrogen, that is, hydrogen supplied to the reactor, because of the simplicity of control. And a method in which the ratio of propylene to propylene (H ₂ / C ₃ ) is gradually decreased.
In batch polymerization, most of the required amount is charged before production, and the hydrogen consumption rate is adjusted, so that the gas concentration ratio of hydrogen to propylene (H ₂ / C ₃ ) in the unreacted gas is 0.1. Control can be performed so that the molar ratio is equal to or lower.

  The hydrogen consumption varies depending on the catalyst, the presence or absence of a polymerization additive, the polymerization time, etc., but in the present invention, in order to keep the hydrogen concentration at the end of production of the crystalline propylene polymer low, the hydrogen consumption rate is larger. Is preferred. From the viewpoint of the consumption rate of hydrogen, a Ziegler catalyst is generally preferable to a metallocene catalyst, and among Ziegler catalysts, a titanium trichloride type is more preferable than a so-called magnesium chloride-supported catalyst.

In this way, the amount of hydrogen is controlled, and at the end of the previous polymerization step (a), the gas concentration ratio of hydrogen to propylene (H ₂ / C ₃ ) in the unreacted gas (H ₂ / C ₃ ) is 0.1 molar ratio or less, preferably Must be 0.09 molar ratio or less, more preferably 0.08 molar ratio or less. If it is at least the upper limit, hydrogen is brought in during the subsequent production of the propylene / ethylene random copolymer, which is disadvantageous in that a highly viscous copolymer cannot be obtained.

  As the timing of supplying hydrogen necessary for the crystalline propylene polymer, it is preferable to charge most of the necessary amount before production. In addition, during the semi-batch polymerization, the amount of hydrogen supplied to propylene can be gradually reduced. By doing so, the average residence time of hydrogen can be made longer than the average residence time in the reactor of propylene, hydrogen can be used more efficiently, the supply amount can be reduced, and as a result Finally, the hydrogen concentration can also be kept low. Further, hydrogen may be supplied at the end of propylene polymerization, or supply may be stopped. When the hydrogen supply is stopped, the supply may be stopped simultaneously with the end of the propylene polymerization, or the supply may be stopped in the middle of the polymerization.

FIG. 1 schematically shows an embodiment in which hydrogen supply to propylene monotonously decreases. The horizontal axis (α) indicates the start of propylene polymerization, (β) indicates the end of polymerization, and the vertical axis indicates the amount of hydrogen supplied to propylene. (1) and (2) of FIG. 1 show the case where it falls linearly, (3)-(5) show the case where it falls like a curve, and (6) shows the case where it falls intermittently.
In the present invention, among the aspects of the hydrogen supply amount, a preferable aspect can be selected as appropriate, but the hydrogen supply amount linearly decreases as shown in FIG. Embodiments are preferred.

(Ix) Production of Propylene / Ethylene Random Copolymer Portion In the previous polymerization step (a), propylene is continuously supplied to produce a crystalline propylene polymer, and after once purging the reactor gas, In the subsequent polymerization step (b), a propylene / ethylene random copolymer portion is produced.
In the subsequent polymerization step (b), propylene, ethylene and hydrogen are continuously supplied, and propylene is present in the presence of the catalyst (the catalyst used in the previous polymerization step (a) (first step)). And propylene / ethylene random copolymer part are produced, and a propylene block copolymer is obtained as a final product.

At this time, since the MFR of the propylene / ethylene random copolymer portion (B) in the (i) propylene-based block copolymer of the present invention needs to be 10 ⁻⁵ g / 10 min or less, the type of process and catalyst However, it is necessary to control the MFR by adjusting the hydrogen of the chain transfer agent to a relatively low concentration.

  In principle, hydrogen is not supplied during the production of the propylene / ethylene random copolymer, but a small amount can be supplied for the purpose of finely adjusting the MFR of the resulting propylene / ethylene random copolymer. If hydrogen is supplied too much, the MFR increases and the flow mark improving effect cannot be obtained.

Further, when the propylene / ethylene random copolymer part (B) is produced, the supply amount of propylene must be decreased over time, while the supply amount of ethylene must be increased while increasing. . By doing so, it becomes possible to reduce MFR of the propylene / ethylene random copolymer portion to 10 ⁻⁵ or less. This is because the chain transfer agent hydrogen is brought in somewhat from the polymerization step (a) to the polymerization step (b), but is consumed at the beginning of the polymerization step (b), and the ethylene concentration in the latter stage of polymerization where there is almost no hydrogen. It is thought that the higher the polymerization rate with respect to chain transfer, the further improvement of the molecular weight, and the reduction of the MFR are possible due to the increase.

  The MFR of the (i) propylene-based block copolymer of the present invention needs to be 100 g / 10 min or more. The MFR of the propylene / ethylene block copolymer is determined by the MFR of the crystalline propylene polymer component, the MFR of the propylene / ethylene random copolymer component, and the quantity ratio of both components.

2. Polypropylene resin composition (1) Component (i): Moldability modifier Component (i) in the polypropylene resin composition of the present invention is used for the purpose of expressing a good flow mark appearance, A moldability modifier for resin is used. This moldability modifier is composed of a propylene homopolymer having extremely excellent fluidity and a propylene / ethylene copolymer having an extremely large molecular weight, and the performance is achieved by combining both.

(2) Component (ii): Polypropylene resin The polypropylene resin represented by component (ii) in the polypropylene resin composition of the present invention is a main component of the polypropylene resin composition and is a resin component that serves as a skeleton. . (Ii) As a polypropylene resin, a propylene / ethylene block copolymer is mainly used, but its production method is not particularly limited, and any known production method can be applied, and commercially available products can be used as they are. Can do. Among these, the following propylene / ethylene block copolymers are preferable.

(Ii) The polypropylene resin is preferably a block copolymer containing a crystalline polypropylene part (A unit part) and a propylene / ethylene random copolymer part (B unit part). 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% as an isotactic index (insoluble matter by boiling n-heptane extraction).
As mentioned above, Preferably it is 95 to 100%. When the crystallinity is small, (ii) the polypropylene resin is inferior in mechanical strength, particularly in bending elastic modulus.

On the other hand, the B unit is a rubbery component obtained by random copolymerization of propylene and ethylene. A unit part is usually 50 to 95% by weight, preferably 60 to 90% by weight of the total polymerization amount.
The B unit is usually adjusted to 5 to 50% by weight, preferably 10 to 40% by weight of the total polymerization amount. 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, (ii) the composition of the polypropylene resin can be determined for the polymer after production by extraction analysis with the above-described orthodichlorobenzene.

  (Ii) The MFR of the polypropylene resin used in the composition of the present invention is preferably 2 g / 10 min or more and less than 40 g / 10 min, more preferably 15 to 40 g / 10 min. If the MFR is less than 2 g / 10 minutes, the moldability is inferior, and if it exceeds 40 g / 10 minutes, the impact resistance is lowered, which is not preferable.

The die swell ratio of the (ii) polypropylene resin used in the composition of the present invention is preferably 0.98 or more and less than 1.2, and more preferably 1.0 or more and less than 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.
The die swell ratio of the (ii) polypropylene resin used in the composition of the present invention is as follows: (ii) After the polypropylene resin is inserted into a 190 ° C. heating cylinder, it is heated and held for 6 minutes, and has a diameter of 1 mm and length. It is a value obtained by extruding from an 8 mm orifice at a rate of 0.1 g / min, measuring the strand diameter, and calculating from the strand diameter / orifice diameter.

The Q value of the (ii) polypropylene resin used in the composition of the present invention is preferably 3 or more and less than 7, more preferably 3.5 to 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, (ii) The Q value of the polypropylene resin used in the composition of the present invention is a weight average molecular weight (Mw) and a number average molecular weight (Mn) using a GPC apparatus (Millipore 150C) equipped with an infrared detector. Was measured and calculated as Mw / Mn. Measurement conditions were measured using orthodichlorobenzene as the mobile phase solvent, high density polyethylene of Mn 18000 and Mw 52200 as the standard substance, and the set temperature of the column and the sample injection part being 140 ° C.

  For the production of the above (ii) polypropylene resin, a method of polymerizing using a highly stereoregular catalyst is preferably used. As the catalyst and the polymerization method, the same method as the method for producing the propylene block copolymer moldability modifier is used. In the production of a polypropylene-based resin having a large amount of propylene / ethylene random copolymer part (B unit part) (ii), 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.

(3) Component (iii): Elastomer In the polypropylene resin composition of the present invention, an elastomer component (iii) can be blended as necessary.
Specific examples of the elastomer component (iii) include, for example, ethylene / propylene copolymer elastomer (ethylene propylene rubber; EPR), ethylene / butene copolymer elastomer (EBR), ethylene / hexene copolymer elastomer (EHR), and ethylene / octene. Ethylene / α-olefin copolymer elastomer such as copolymerized elastomer (EOR); Ethylene / α such as ethylene / propylene / ethylidenenorbornene copolymer, ethylene / propylene / butadiene copolymer, ethylene / propylene / isoprene copolymer -Olefin-diene terpolymer elastomer (EPDM); styrene-butadiene-styrene triblock (SBS), styrene-isoprene-styrene triblock (SIS), styrene-butadiene-styrene Styrenic elastomers such as triblock hydrogenated products (SEBS) and styrene / isoprene / styrene triblock hydrogenated products (SEPS) can be used.
The above hydrogenated product of styrene / butadiene / styrene triblock is generally abbreviated as SEBS because the polymer main chain is styrene-ethylene-butene-styrene when viewed in monomer units.
These elastomer components (iii) can be used by mixing two or more kinds.

  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 Corporation, Tuffmer P series and Tuffmer A series manufactured by Mitsui Chemicals, and Engage EG series manufactured by DuPont Dow, all of which are used in the present invention. Can do.

  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). Method) and a styrene-butadiene diblock copolymer after first producing a triblock body using a coupling agent, followed by hydrogenation. Moreover, the hydrogenated product (SEPS) of a styrene-isoprene-styrene triblock body can be similarly manufactured by using isoprene instead of butadiene.

  The MFR of the elastomer (component (iii)) used in the composition of the present invention is preferably 0.5 to 150 g / 10 min, more preferably 0.7 to 100 g / 10 min, particularly preferably 0.7 to 80 g / min. 10 minutes. In consideration of the automobile exterior material which is the main application of the present invention, those having an MFR in the above range are particularly preferable.

(4) Component (iv): Inorganic filler In the polypropylene resin composition of the present invention, an inorganic filler (component (iv)) can be blended as necessary. Component (iv) is used for improving the flexural modulus and decreasing the linear expansion coefficient. As an inorganic filler of this invention, a composition, a shape, etc. are not specifically limited. Any commercially available polymer filler can be used. The shape can be arbitrarily selected from fiber, single fiber, perfect circle, powder, and flake. A particle size of 0.1 to 100 μm, preferably about 0.5 to 20 μm can be arbitrarily used, but is not limited to this particle size.

  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, carbonic acid Examples thereof include granular inorganic fillers such as magnesium and balun-like inorganic fillers such as glass balloons. Among them, talc is particularly preferable from the viewpoint of physical properties and cost.

When using a preferable talc as a filler, the average particle diameter is preferably 10 μm or less, preferably 0.5 to 8 μm.
The average particle diameter is a cumulative amount of 50% by weight read from a particle size cumulative distribution curve measured by a laser diffraction method (for example, LA920W manufactured by Horiba, Ltd.) or a liquid layer sedimentation method light transmission method (for example, CP type manufactured by Shimadzu Corporation). It can obtain | require from the particle size value of. The measured values in the examples of the present invention are those obtained by the former method.

These talcs can be obtained by classifying one that has been produced naturally by mechanically pulverizing one or more times. Examples of the pulverizer include a jaw crusher, a hammer crusher, a roll crusher, a screen mill, a jet pulverizer, a colloid mill, a roller mill, and a vibration mill.
These pulverized talcs are wet once or repeatedly in an apparatus such as a cyclone, a cyclone air separator, a micro separator, a cyclone air separator, a sharp cut separator to adjust to the average particle size shown in the present invention. Perform dry classification. It is preferable to perform classification operation with a sharp cut separator after pulverization to a specific particle size.

  These talcs are modified polyolefins grafted with various organic titanate coupling agents, organic silane coupling agents, unsaturated carboxylic acids, or anhydrides for the purpose of improving the adhesion or dispersibility with the polymer. What was surface-treated with a fatty acid, a fatty acid metal salt, a fatty acid ester, or the like may be used.

(5) Component (v); additional component (optional component)
In the polypropylene resin composition of the present invention, in addition to the above components (i) to (iv), other additional components (optional components) (component (v ) Can be added.
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.

3. Blending Ratio of Polypropylene Resin Composition The polypropylene resin composition of the present invention is produced by appropriately combining the components (i) to (v). Typically, compositions of components (i) and (ii), compositions of components (i), (ii) and (iii), compositions of components (i), (ii) and (iv), components (I), (ii), (iii) and (iv) compositions, etc., and further usually component (v) is blended.

In the compounding ratio of the components (i) and (ii), (i) the moldability modifier is 1 to 30 parts by weight, preferably 2 to 25 parts by weight, particularly preferably 3 to 20 parts by weight. a section, (ii) polypropylene resin, 70 to 99 parts by weight, preferably 75 to 98 parts by weight, particularly preferably 80 to 97 parts by weight. (I) If the moldability modifier is less than 1 part by weight, the molding appearance improving effect is inferior. Conversely, if it exceeds 30 parts by weight, the impact resistance is inferior.

Below, modifier 3 consisting of component (i) based on Example 3 and polypropylene resin of component (ii) (A unit part: about 75% by weight, B unit part: about 25% by weight, MFR: about 30 g / 10 A standard embodiment or sample standard specification for a composition comprising

Specification number 1 2 3 4 5
Component (i) (parts by weight) 0.5 5 15 25 35
Component (ii) (parts by weight) 99.5 95 85 75 65

A test piece for evaluating physical properties using a conventional mixing apparatus and a molding apparatus such as injection molding, which are usually used for various materials of component (i) and component (ii) shown by these specification numbers 1 to 5, or A molded product is formed arbitrarily.
If it evaluates comprehensively, in the specification number 1, the compounding quantity of component (i) is as very small as about 0.5 weight part, and the effect of the moldability of component (i) cannot be expected. On the other hand, if the compounding amount of the component (i) is 35 parts by weight as in the specification number 5 or, in some cases, 40 parts by weight or 50 parts by weight, the original resin characteristics of the component (ii) are It is not preferable because it is lost and impact resistance is extremely lowered. The behavior of these physical properties is a property that appears on a continuous line that is generally linked to the change in the amount of blending, and as shown in the detailed description by Examples 1 to 6 and Comparative Examples described later, component (i) The proper blending amount is 1 to 30 parts by weight including the range of the specification numbers 2 to 4, and the proper blending amount is 3 to 20 parts by weight, preferably 5 to 15 parts by weight. It is possible to provide a material that is well balanced in terms of formability and physical property values.

  In the blending ratio in the composition of components (i), (ii) and (iii), the blending ratio of components (i) and (ii) is the same as above, and component (iii) ) And (ii), preferably 1 to 40 parts by weight, more preferably 2 to 30 parts by weight, and particularly preferably 3 to 20 parts by weight. When the component (iii) is less than 1 part by weight, the effect of addition is not sufficiently exhibited. Conversely, when the component (iii) exceeds 40 parts by weight, there is a concern about reduction in rigidity, and there is a problem in cost. However, there are various blends depending on the purpose and application, and the compound is not limited to the above depending on the type of elastomer, and it is also important to select according to the application and purpose.

Below, modifier 1 consisting of component (i) based on Example 1 and polypropylene resin of component (ii) (A unit part: about 75% by weight, B unit part: about 25% by weight, MFR: about 30 g / 10 The standard embodiment or sample standard specification in the case of using the ethylene / propylene elastomer of component (iii) in combination with a composition consisting of about a minute).

Specification number 1 2 3 4 5
Ingredient (i) (parts by weight) 5 15 22 25 30
Component (ii) (parts by weight) 95 85 78 75 70
Ingredient (iii) (parts by weight) 1 15 32 40 50

The physical properties of the components (i), (ii) and (iii) indicated by these specification numbers 1 to 5 are measured using a conventional mixing apparatus and a molding apparatus such as injection molding, which are usually used. A test piece to be evaluated or a molded product can be arbitrarily formed.
If it evaluates comprehensively, in the specification numbers 1-5, it is the material of the specification which the compounding quantity of a component (i)-a component (ii) satisfy | fills the range specified by this invention, and ethylene of the component (iii) used together with this The trend of the compounding amount of a styrene-based elastomer or a styrene-based elastomer is shown. The behavior of the amount of component (iii) appears, for example, from the state in which 1 part by weight of component (iii) is added to 100 parts by weight of the total of component (i) and component (ii) shown in specification number 1. The material behavior of component (iii) shown in specification numbers 2 to 4 meets the purpose of the present invention. On the other hand, when the blending amount of component (iii) is 50 parts by weight as in specification number 5 and exceeds the limited range of the present invention, the properties of the elastomer appear and the properties of component (ii) of the base polymer are lost.
The meaning of using the component (iii) elastomer together is mainly to improve the impact resistance, particularly the low temperature impact resistance of the polypropylene resin of the component (ii). When the blend amount of the component (iii) is monotonously increased according to the specification numbers 1 to 5, the impact resistance of the polypropylene resin of the component (ii) tends to increase in proportion. However, if the amount of component (iii) increases, the original characteristics of component (ii) disappear and the rigidity tends to decrease monotonously.
The behavior of these physical properties is such that it is placed on a continuous line that is generally linked to the change in the blend amount, and as shown in the detailed description by Examples 1 to 6 and Comparative Examples described later, the component (iii) The proper blending amount is 1 to 40 parts by weight including the range of specification numbers 1 to 4, and the proper blending amount is 3 to 20 parts by weight for improving the impact resistance of the polypropylene resin of component (ii). Therefore, it is possible to provide a material that is well balanced in terms of moldability and physical properties of the polypropylene resin composition.

In the blending ratio of the components (i), (ii) and (iv) in the composition, the blending ratios of the components (i) and (ii) are the same as described above, and the component (iv) is the component (i). And 1-70 weight part is preferable with respect to a total of 100 weight part of (ii), More preferably, it is 2-50 weight part, Especially preferably, it is 5-40 weight part. (Iv) If the inorganic filler is less than 1 part by weight, the effect of addition is not sufficiently exhibited and the flexural modulus is insufficient. Conversely, if it exceeds 70 parts by weight, the embrittlement temperature deteriorates and the moldability also decreases.

  In the compounding ratio of the components (i), (ii), (iii), and (iv), the components (i) and (ii) are the same as described above, and the component (iii) 1-40 weight part is preferable with respect to a total of 100 weight part of i) and (ii), More preferably, it is 2-30 weight part, Especially preferably, it is 3-20 weight part. Component (iv) is preferably 1 to 70 parts by weight, more preferably 2 to 50 parts by weight, particularly preferably 100 parts by weight in total of components (i), (ii) and (iii). Is 5 to 40 parts by weight.

Below, modifier 3 consisting of component (i) based on Example 3 and polypropylene resin of component (ii) (A unit part: about 75% by weight, B unit part: about 25% by weight, MFR: about 30 g / 10 The standard embodiment or sample standard specification when the inorganic filler of the component (iv) is used in combination with the composition of the component (iii) and the ethylene / butene copolymer elastomer of the component (iii) is shown. Specification number 1; calcium carbonate, specification numbers 2 and 3; talc, specification number 4; silica, specification number 5; standard specification for talc.

Specification number 1 2 3 4 5
Ingredient (i) (parts by weight) 10 10 22 22 30
Component (ii) (parts by weight) 90 90 78 78 70
Ingredient (iii) (parts by weight) 5 10 14 20 35
Ingredient (iv) (parts by weight) 3 15 22 34 50

Using a conventional mixing apparatus and a molding apparatus such as injection molding that normally use various materials of component (i), component (ii), component (iii), and component (iv) indicated by these specification numbers 1 to 5 Thus, a test piece for evaluating physical properties or a molded product can be arbitrarily formed.
If it performs comprehensive evaluation, in the specification numbers 1-5, it is the material of the specification with which the compounding quantity of a component (i)-a component (iii) satisfy | fills the range specified by this invention, and the inorganic of the component (iv) used together with this The specifications and trends in the amount of fillers are shown. The behavior of the blending amount of component (iv) appears, for example, from the state in which 3 parts by weight of component (iv) is added to 100 parts by weight of components (i) to (iii) shown in specification number 1. The material behavior based on the added amount of component (iv) shown in the numbers 2 to 4 is suitable for the purpose of the present invention. When the blending amount of the component (iv) is about 50 weight as in the specification number 5, the characteristics of the component (ii) as the base polymer are lost.
The meaning of adding the inorganic filler of component (iv) is mainly to improve the rigidity, low warpage, dimensional stability, weight gain, etc. of the polypropylene resin of component (ii). When the addition amount of the component (iv) is monotonously increased according to the specification numbers 1 to 5, the tensile characteristics, compression characteristics, and heat distortion resistance of the polypropylene resin of the component (ii) are improved. If the amount of addition increases as in specification number 5, the embrittlement temperature and flexibility tend to deteriorate.
When the addition amount is small, the flexural modulus is insufficient and the effect of adding the component (iv) cannot be expected. On the other hand, if the amount of component (iv) is increased, the plasticizing and kneading operations become very difficult. By using a lubricant such as paraffin wax, fatty acid metal salt, and fatty acid amide in combination, there is a problem in processing. Can be overcome.
The behavior of the physical properties by these additives shows a characteristic that tends to be placed on a continuous line that is generally linked to the change in the amount of the additive, but will be described in detail in Examples 1 to 6 and Comparative Examples described later. As shown.

  As described above, the composition of the present invention is characterized by the presence or absence of such component (iii) elastomer, component (iv) inorganic filler, and the increase or decrease in blend or addition amount thereof. The moldability modifier for polypropylene resin comprising the propylene-based block copolymer of component (i) exhibits the effect of improving the flow mark characteristics during molding of the polypropylene-based resin composition of component (ii). That is an unexpected behavior.

4). Production of Polypropylene Resin Composition Production of the polypropylene resin composition of the present invention is carried out by using the above-mentioned constituent components in the above proportions in ordinary kneaders such as extruders, Banbury mixers, rolls, Brabender plastographs, kneaders, etc. And kneading at a set temperature of 180 ° C to 250 ° C. Among these kneaders, it is preferable to produce using an extruder, particularly a twin screw extruder.

5). 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 Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples. Analysis and evaluation methods performed in Examples and Comparative Examples are as follows.

1. Melt flow rate (MFR)
Measured according to JIS-K-7210, temperature 230 ° C., load 21.18 N (unit: g / 10 minutes).
2. Molecular weight distribution (Mw / Mn)
It was determined by GPC measurement under the following apparatus and conditions.
Apparatus: Waters, GPC150C type Column: Showa Denko, AD80M / S, 3 Measurement temperature: 140 ° C
Concentration: 20mg / 10ml
Solvent: Orthodichlorobenzene

3. Method for Analyzing Physical Properties of Propylene Block Copolymer (i) Ratio of propylene / ethylene random copolymer portion (B) (hereinafter sometimes referred to as rubber component) in propylene block copolymer Wc) and the ethylene content and intrinsic viscosity in the rubber component are measured 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. In addition, the elution ratio (unit:% by 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), respectively W ₄₀ , W ₁₀₀ , and W ₁₄₀ are defined. 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 of FT-IR After elution of the sample solution from the 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 × Mα) used at that time.
(I) When creating a 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 (l)
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 (l) is as follows. That is, the first term on the right side of the formula (l) 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 part 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 A40 / B40 in the first term on the right side means that the contribution of the propylene / ethylene random copolymer is calculated from the weight% (W ₄₀ ) of fraction 1. 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, it is possible to successfully explain the effect of improving the physical properties of B ₄₀ when the ethylene content corresponding to the peak position of the differential molecular weight distribution curve of fraction 1 is used. all right. Also, B ₁₀₀ is to have a crystallinity of ethylene-derived chain, and, as compared to the amount of propylene-ethylene random copolymer the amount of propylene-ethylene random copolymer contained in these fractions is 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. is 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) In addition, 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

<Example 1>
1. Production of solid catalyst component (a) 20 liters of dehydrated and deoxygenated n-heptane and 20 liters of MgCl ₂ , Ti (On -C ₄ H ₉ ) ₄ was introduced in an amount of 20 mol and reacted at 95 ° C. for 2 hours. After completion of the reaction, the temperature was lowered to 40 ° C., and then 12 liters of methylhydropolysiloxane (20 centistokes) was introduced and reacted for 3 hours. The resulting solid component was washed with n-heptane.
Subsequently, 5 liters of n-heptane purified as described above was introduced into the tank using the tank equipped with a stirrer, and 3 mol of the solid component synthesized above was introduced in terms of Mg atoms. Subsequently, 5 mol of SiCl ₄ was mixed with 2.5 liters of n-heptane, introduced into the flask at 30 ° C. for 30 minutes, and reacted at 70 ° C. for 3 hours. After completion of the reaction, washing with n-heptane was performed.
Next, 2.5 liters of n-heptane was introduced into the tank equipped with a stirrer, 0.3 mol of phthalic acid chloride was mixed, introduced at 70 ° C. for 30 minutes, and reacted at 90 ° C. for 1 hour. After completion of the reaction, washing with n-heptane was performed. Next, 2 liters of TiCl ₄ was introduced and reacted at 110 ° C. for 3 hours. After completion of the reaction, the solid component (a1) for producing the solid catalyst component (a) was obtained by washing with n-heptane. The titanium content of this solid component was 2.0% by weight.
Next, 8 liters of n-heptane and 400 grams of the solid component (a1) synthesized above were introduced into the tank equipped with a stirrer substituted with nitrogen, and 0.6 liter of SiCl ₄ was introduced as the component (a2) at 90 ° C. The reaction was performed for 2 hours. After completion of the reaction, 0.54 mol of (CH ₂ ═CH) Si (CH ₃ ) ₃ as the component (a3) and (tC ₄ H ₉ ) (CH ₃ ) Si (OCH ₃ ) ₂ as the component (a4) 0.27 mol and 1.5 mol of Al (C ₂ H ₅ ) ₃ as component (a5) were sequentially introduced and contacted at 30 ° C. for 2 hours. After completion of the contact, the product was thoroughly washed with n-heptane to obtain 390 g of component (a) mainly composed of magnesium chloride. The titanium content of this product was 1.8% by weight.

2. (I) Production of propylene-based block copolymer A stainless steel autoclave with a stirrer having an internal volume of 400 liters was sufficiently substituted with propylene gas, and 120 liters of dehydrated and deoxygenated n-heptane was added as a polymerization solvent. Next, 30 g of triethylaluminum, 147 liters of hydrogen, and 17 g of the catalyst “a” were added under a temperature of 70 ° C. After the temperature of the autoclave was raised to an internal temperature of 75 ° C., propylene was supplied so that the pressure became 0.3 MPaG, and polymerization was started. Hydrogen started to be supplied at a hydrogen / propylene ratio of 13.6 (L / Kg), and was reduced at a constant rate so as to reach 0 after 230 minutes. After 230 minutes, the introduction of propylene was stopped, and the unreacted gas in the vessel was released to 0.03 MPaG to obtain a crystalline propylene polymer portion (preliminary polymerization step). The hydrogen concentration (hydrogen / propylene) in the reactor was 0.24 molar ratio at the start of polymerization, but gradually decreased, and 0.08 molar ratio when propylene supply was stopped.
Next, after setting the autoclave at an internal temperature of 65 ° C., 12.5 cc of n-butanol was introduced, and then the propylene was reduced at a constant rate so that it became 0 120 minutes after the start of feeding at 5.25 Kg / Hr. 120 minutes after that, it was supplied at a constant rate so as to be 2.25 Kg / Hr. After 120 minutes, the supply of ethylene and propylene was stopped to complete the polymerization. The pressure was 0.03 MPaG at the start of ethylene and propylene supply, but was 0.03 MPaG when the supply was stopped (second-stage polymerization step).
The obtained slurry was transferred to the next tank equipped with a stirrer, 2.5 liters of butanol was added, treated at 70 ° C. for 3 hours, further transferred to the next tank equipped with a stirrer, and 100 g of pure water in which 20 g of sodium hydroxide was dissolved. After adding 1 liter and treating for 1 hour, the aqueous layer was allowed to stand and then separated to remove the catalyst residue. The slurry was treated with a centrifuge to remove heptane, and then treated with a dryer at 80 ° C. for 3 hours to completely remove heptane to obtain 59.6 kg of (Modifier 1).

3. Production of solid catalyst component (b) 20 liters of dehydrated and deoxygenated n-heptane is introduced into a tank equipped with a stirrer with an internal volume of 50 liters purged with nitrogen, and then 10 moles of magnesium chloride and 20 moles of tetrabutoxytitanium are introduced. Then, after reacting at 95 ° C. for 2 hours, the temperature was lowered to 40 ° C., 12 liters of methylhydropolysiloxane (viscosity 20 centistokes) was introduced, and further reacted for 3 hours. The 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 (b) (390 g) was obtained by washing with heptane.
The obtained solid catalyst component (b) 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 (b) in which 0.9 g of propylene was polymerized per 1 g of solid was obtained.

4). (Ii) Production of polypropylene resin 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 75 ° C., a propylene partial pressure of 1.8 MPa, and hydrogen as a molecular weight controlling agent are continuously fed so that the molar ratio of hydrogen / propylene is 0.047. Was supplied at 5.25 g / hr as the solid catalyst component (b) so that the polymer polymerization rate was 20 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 60 kg and transferred continuously to the second reactor (pre-stage polymerization step). .
Propylene and ethylene are continuously supplied at a polymerization temperature of 80 ° C. and a pressure of 2.0 MPa so that the molar ratio of ethylene / propylene is 0.37. Further, hydrogen as a molecular weight control agent is In addition to continuously supplying 0.016 in the molar ratio of / propylene, 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 extracted into the vessel so that the amount of powder held in the reactor is 40 kg, and the reaction is stopped by supplying nitrogen gas containing moisture to obtain a polypropylene resin. (Post polymerization process). The obtained polypropylene resin was used as the base PP.
When the base PP was analyzed, the MFR was 31 g / 10 min, the rubber content was 27 wt%, the die swell ratio was 1.0, and the Q value was 4.6.

5). Evaluation of molded product appearance flow mark generation distance Ethylene butene having the above base PP (55 wt%), talc (15 wt%) having an average particle diameter of 5 μm, MFR of 6.3 g / 10 min, and density of 0.862 g / cc As an antioxidant, tetrakis [methylene-3- (3′5′-di-t-) was used as an antioxidant with respect to 100 parts by weight of the copolymer elastomer (15% by weight) and the mixture of the above modifier 1 (15% by weight). Butyl-4′-hydroxyphenyl) propionate] methane (product name: Irganox 1010) 0.1 part by weight, tris (2,4-di-t-butylphenyl) phosphite (product manufactured by Ciba Geigy) Name: Irgafos 168) 0.05 part by weight was mixed and mixed for 5 minutes with a Henschel mixer, then 210 ° C. with a twin-screw kneader (Kobe Steel Corporation: KCM). To obtain a polypropylene resin composition by kneading granulation at a constant temperature. About the obtained polypropylene resin composition, MFR and flow mark generation distance were performed.
The generation distance of the flow mark is an injection molding machine with a clamping pressure of 170 tons, using a mold with a film gate with a width of 2 mm on the short side, and a molding sheet of 350 mm × 100 mm × 2 mmt is injection molded at a molding temperature of 220 ° C. Then, the generation of the flow mark was visually observed, and the distance from the gate to the portion where the flow mark was generated was measured.

For each example, Table 1 shows the polymerization conditions, and Table 2 shows the physical properties of the produced polymer.

<Example 2>
In Example 1, the supply amount of hydrogen was started at 18.0 (L / Kg) of hydrogen / propylene in the pre-stage polymerization step, and decreased at a constant rate so that it became 0 after 230 minutes. Example 1 except that ethylene was lowered at a constant rate so that it would be 0 after 120 minutes from the start of feeding at 7.35 Kg / Hr, and ethylene was fed at a constant rate so that it would be 3.15 Kg / Hr after 120 minutes from 0. Propylene / ethylene block copolymer (Modifier 2) was produced according to 1. The hydrogen concentration (hydrogen / propylene) in the reactor of the pre-stage polymerization process was 0.09 molar ratio when propylene supply was stopped. Moreover, the obtained product amount was 59.1 kg.
Further, the evaluation of the generation distance of the flow mark was performed according to Example 1 with the modifier 1 being changed to the modifier 2.

<Example 3>
In Example 1, the supply amount of hydrogen in the first-stage polymerization step was started at a hydrogen / propylene ratio of 10.0 (L / Kg), and decreased at a constant rate so that it became 0 after 230 minutes. Example 1 except that ethylene was lowered at a constant rate so that it became 0 after 120 minutes from the start of feeding at 5.25 Kg / Hr, and ethylene was fed at a constant rate so that it would become 2.25 Kg / Hr after 120 minutes from 0. Propylene / ethylene block copolymer (Modifier 3) was produced according to 1. The hydrogen concentration (hydrogen / propylene) in the reactor of the pre-stage polymerization step was 0.07 molar ratio when propylene supply was stopped. Moreover, the obtained product amount was 58.3 kg.
Moreover, the evaluation of the generation distance of the flow mark was performed according to Example 1 with the modifier 1 changed to the modifier 3.

<Example 4>
In Example 1, the supply amount of hydrogen was started at 13.6 (L / Kg) of hydrogen / propylene in the pre-stage polymerization step, and decreased at a constant rate so that it became 0 after 230 minutes. Example 1 except that ethylene was lowered at a constant rate so as to become 0 after 60 minutes from the start of supply at 10.5 Kg / Hr, and ethylene was supplied at a constant rate so as to become 4.5 Kg / Hr after 0 to 60 minutes. Propylene / ethylene block copolymer (Modifier 4) was produced according to 1. The hydrogen concentration (hydrogen / propylene) in the reactor of the pre-stage polymerization step was 0.08 molar ratio when propylene supply was stopped. Moreover, the obtained product amount was 59.4 kg.
Further, the evaluation of the generation distance of the flow mark was performed according to Example 1 with the modifier 1 changed to the modifier 4.

<Example 5>
In Example 1, the supply amount of hydrogen was started at 13.6 (L / Kg) of hydrogen / propylene in the pre-stage polymerization step, and decreased at a constant rate so that it became 0 after 230 minutes. Example 1 except that ethylene was lowered at a constant rate so that it became 0 after 120 minutes from the start of feeding at 7.65 Kg / Hr, and ethylene was fed at a constant rate so that it became 1.35 Kg / Hr after 0 to 120 minutes. Propylene / ethylene block copolymer (Modifier 5) was produced according to 1. The hydrogen concentration (hydrogen / propylene) in the reactor of the pre-stage polymerization step was 0.08 molar ratio when propylene supply was stopped. Moreover, the obtained product amount was 58.9 kg.
The evaluation of the flow mark generation distance was performed according to Example 1 with the modifier 1 changed to the modifier 5.

<Example 6>
In Example 1, the supply amount of hydrogen was started at 13.6 (L / Kg) of hydrogen / propylene in the pre-stage polymerization step, and decreased at a constant rate so that it became 0 after 230 minutes. Example 3 except that ethylene was lowered at a constant rate so as to become 0 after 120 minutes from the start of feeding at 3.75 Kg / Hr, and ethylene was fed at a constant rate so as to become 3.75 Kg / Hr after 0 to 120 minutes. Propylene / ethylene block copolymer (Modifier 6) was produced according to 1. The hydrogen concentration (hydrogen / propylene) in the reactor of the pre-stage polymerization step was 0.07 molar ratio when propylene supply was stopped. Moreover, the obtained product amount was 59.6 kg.
Further, the evaluation of the generation distance of the flow mark was performed according to Example 1 with the modifier 1 changed to the modifier 6.

<Comparative Example 1>
In Example 1, the catalyst amount was set to 20 g, and in the pre-stage polymerization process, the supply amount of hydrogen / propylene was started at 10.0 (L / Kg), and decreased at a constant rate so that it became 0 after 230 minutes. In the latter polymerization step, propylene / ethylene block was carried out in the same manner as in Example 1 except that propylene was supplied at a constant rate of 2.63 Kg / Hr, ethylene at 1.13 Kg / Hr, and the supply was stopped after 120 minutes. A copolymer (Modifier 8) was produced. The hydrogen concentration (hydrogen / propylene) in the reactor of the pre-stage polymerization step was 0.06 molar ratio when propylene supply was stopped. Moreover, the obtained product amount was 55.4 kg.
Further, the evaluation of the flow mark generation distance was performed in accordance with Example 1 with the modifier 1 changed to the modifier 8.

<Comparative example 2>
In Example 1, hydrogen / propylene was supplied at a constant rate of 2.0 (L / Kg) in the pre-stage polymerization step, and the supply was stopped after 220 minutes. In the post-stage polymerization step, propylene was added at 3.5 Kg. Propylene / ethylene block copolymer (Modifier 9) was carried out in the same manner as in Example 1 except that ethylene was supplied at a constant rate of 1.5 Kg / Hr at / Hr and stopped after 90 minutes. Manufactured. The hydrogen concentration (hydrogen / propylene) in the reactor of the pre-stage polymerization step was 0.14 molar ratio when propylene supply was stopped. Moreover, the obtained product amount was 59.6 kg.
Further, the evaluation of the flow mark generation distance was performed according to Example 1 with the modifier 1 changed to the modifier 9.

<Comparative Example 3>
In Example 1, the supply amount of hydrogen was started at 13.6 (L / Kg) of hydrogen / propylene in the pre-stage polymerization step, and decreased at a constant rate so that it became 0 after 230 minutes. Example 1 except that ethylene was reduced at a constant rate so that it became 0 after 120 minutes from the start of supply at 2.7 Kg / Hr, and ethylene was supplied at a constant rate so that it became 6.3 Kg / Hr after 0 to 120 minutes. Propylene / ethylene block copolymer (Modifier 10) was produced according to 1. The hydrogen concentration (hydrogen / propylene) in the reactor of the pre-stage polymerization process was 0.09 molar ratio when propylene supply was stopped. Moreover, the obtained product amount was 59.4 kg.
Further, the evaluation of the flow mark generation distance was carried out according to Example 1 with the modifier 1 changed to the modifier 10.

<Comparative example 4>
In Example 1, the supply amount of hydrogen was started at 13.6 (L / Kg) of hydrogen / propylene in the pre-stage polymerization step, and decreased at a constant rate so that it became 0 after 230 minutes. Example 1 except that ethylene was lowered at a constant rate so as to become 0 after 120 minutes from the start of supply at 10.8 Kg / Hr, and ethylene was supplied at a constant rate so as to become 1.2 Kg / Hr after 120 minutes from 0. Propylene / ethylene block copolymer (Modifier 11) was produced according to 1. The hydrogen concentration (hydrogen / propylene) in the reactor of the pre-stage polymerization step was 0.08 molar ratio when propylene supply was stopped. Moreover, the obtained product amount was 60.1 kg.
Moreover, the evaluation of the generation distance of the flow mark was performed according to Example 1 with the modifier 1 changed to the modifier 11.

<Comparative Example 5>
In Example 1, the supply amount of hydrogen was started at 13.4 (L / Kg) of hydrogen / propylene in the pre-stage polymerization step, and decreased at a constant rate so that it became 0 after 230 minutes. Example 1 except that ethylene was lowered at a constant rate so as to become 0 after 120 minutes from the start of supply at 8.4 kg / hr, and ethylene was fed at a constant rate so as to reach 3.6 kg / hr after 120 minutes. Propylene / ethylene block copolymer (Modifier 12) was produced according to 1. The hydrogen concentration (hydrogen / propylene) in the reactor of the pre-stage polymerization step was 0.08 molar ratio when propylene supply was stopped. Moreover, the obtained product amount was 58.3 kg.
Further, the evaluation of the flow mark generation distance was performed in accordance with Example 1 with the modifier 1 changed to the modifier 12.

<Comparative Example 6>
The evaluation of the flow mark generation distance was carried out without any modifier. That is, in Example 1, a propylene / ethylene block copolymer (73 parts by weight) having a rubber content of 27 wt% and an MFR of 31 g / 10 min, talc (15 parts by weight) having an average particle diameter of 5 μm, and an MFR of 6.3 g / 10 min, a polypropylene resin composition in which an antioxidant was mixed with a mixture of ethylene / butene copolymer elastomer (12 parts by weight) having a density of 0.862 g / cc, and the others were carried out according to Example 1. .

The following matters were found from the above examples and comparative examples.
(1) Examples 1 to 6 are moldings for a polypropylene resin comprising a high flow propylene / ethylene block copolymer having a high MFR crystalline propylene polymer part and a low MFR propylene / ethylene random copolymer part. From the comparison of Comparative Examples 1 and 2, the flow mark generation distance is long.
(2) Comparative Example 1 is an example in which the MFR of the propylene / ethylene random copolymer portion is high, and the flow mark generation distance is short as compared with Examples 1-6.
(3) Comparative Example 2 is an example in which the MFR of the crystalline propylene polymer part is low and the MFR of the propylene / ethylene random copolymer part is high. From comparison with Examples 1 to 6, the flow mark generation distance is short.
(4) Comparative Examples 3 and 4 are examples in which the ethylene content of the propylene / ethylene random copolymer portion does not fall within the range of 10 to 50 wt%. From comparison with Examples 1 to 6, the flow mark generation distance is short. .
(5) Comparative Example 5 is an example in which the MFR of the propylene / ethylene block copolymer part is less than 100 g / 10 min. From a comparison with Examples 1 to 6, the MFR of the polypropylene resin composition is low.
(6) Comparative Example 6 is an example in which the propylene / ethylene block copolymer part was not added. From a comparison with Examples 1 to 6, the polypropylene resin composition had a low MFR and a short flow mark generation distance. .

  It can be processed into various general-purpose products such as sheets, films, fibers, ropes, strings and bands by extrusion molding. By injection molding, housing, home appliances, industrial products, buckets, trays, tableware, toys, stationery, fasteners, buttons, daily necessities, screws, bolts, packing, bumpers, front grills, radiator fans, instrument panels, radiator grills It can be used in the application fields of general-purpose materials such as interior materials and exterior materials such as creep-resistant and impact-resistant automotive materials, pipes, underground drainage perforated pipes, agricultural materials, construction materials, and building materials. It can also be used for blown or injection molded products such as containers, tanks, water tanks, bathtubs and bottles.

The figure which shows typically the example of an embodiment in which the ratio of hydrogen and propylene falls monotonously

Claims (10)

(I) a propylene-based block comprising a segment of a crystalline propylene polymer portion (A) and a segment of a propylene / ethylene random copolymer portion (B), and having an MFR of 100 g / 10 min or more Copolymer.
(A) MFR is 500 g / 10 min or more,
(B) MFR is 10 ⁻⁵ g / 10 min or less,
The ethylene content in (B) is 10 to 50% by weight.   It consists of 70 to 95 weight% of segments of a crystalline propylene polymer part (A), and 5 to 30 weight% of segments of a propylene-ethylene random copolymer part (B). (I) A moldability modifier for polypropylene resins comprising a propylene block copolymer.   It comprises 1 to 30 parts by weight of a moldability modifier according to claim 1 or 2 and (ii) 70 to 99 parts by weight of a polypropylene resin, comprising (i) a propylene-based block copolymer. Polypropylene resin composition with excellent molded appearance.   (Ii) The melt flow rate (JIS-K7210, temperature 230 ° C., load 21.18 N) of the polypropylene resin is 2 g / 10 min or more and less than 40 g / 10 min, the die swell ratio is 0.98 or more and less than 1.2, Q value The polypropylene resin composition according to claim 3, wherein is 3 or more and less than 7.   1 to 40 parts by weight of (iii) ethylene-based or styrene-based elastomer is further added to 100 parts by weight of the total of (i) propylene-based block copolymer and (ii) polypropylene-based resin. Item 5. The polypropylene resin composition according to Item 3 or 4.   (Ii) The polypropylene resin composition according to any one of claims 3 to 5, wherein the polypropylene resin is a propylene / ethylene block copolymer.   4. The method according to claim 3, wherein (iv) 1 to 70 parts by weight of an inorganic filler is further added to 100 parts by weight of the total of (i) propylene-based block copolymer and (ii) polypropylene-based resin. 5. The polypropylene resin composition according to 4.   (Iii) The melt flow rate (JIS-K7210, temperature 230 ° C., load 21.18 N) of the ethylene-based or styrene-based elastomer is 0.3 to 150 g / 10 min, according to claim 5. Polypropylene resin composition.   (Iv) The polypropylene resin composition according to claim 7, wherein the inorganic filler is talc. At least two stages including a pre-stage polymerization step (a) for producing the crystalline propylene polymer part (A) component and a post-stage polymerization step (b) for producing the propylene / ethylene random copolymer part (B) component In the method for producing a propylene-based block copolymer by a semi-batch method comprising steps, the polymerization step (a) in the previous stage supplies hydrogen and propylene into a reactor, and the hydrogen concentration relative to propylene is adjusted in the presence of a catalyst. When propylene is polymerized while being lowered over time to obtain a crystalline propylene polymer, the gas concentration ratio (H ₂ / C ₃ ) of hydrogen and propylene in the unreacted gas is 0.1 molar ratio or less. The propylene supply amount is decreased with time in the subsequent polymerization step (b), and the ethylene supply amount is supplied while being increased with time. The manufacturing method of the propylene-type block copolymer of 2.