JP2006188563A - Polypropylene-based resin composition excellent in flexibility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polypropylene-based resin composition having flexibility, excellent in heat resistance and transparency, and decreased in stickiness. <P>SOLUTION: This polypropylene-based resin composition contains 99-70 wt% of a propylene-ethylene random block copolymer as a component (A) and 1-30 wt% of a process oil component as a component (B) and has a modulus of flexure of ≤250 MPa, wherein the component (A) comprises the propylene-ethylene random block copolymer obtained from sequential polymerization by using a metallocene-based catalyst, so that a crystalline propylene-ethylene random copolymer component having an ethylene content of 1-7 wt% is polymerized in an amount of 30-70 wt% in a first process and sequentially a low-crystalline or amorphous propylene-ethylene random copolymer component having an ethylene content higher than the ethylene content obtained in the first process by 6-15 wt% is polymerized in an amount of 70-30 wt% in a second process, and satisfies condition (i) as follows: (i) a tanδ curve obtained by solid viscoelasticity measurement of the component (A) has a single peak at a temperature of ≤0°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polypropylene resin composition, specifically, it contains a propylene-ethylene random block copolymer obtained by sequential polymerization using a metallocene catalyst and a process oil, and is extremely excellent in flexibility and transparency. The present invention relates to a novel polypropylene resin composition that has a good balance between heat resistance and blocking resistance and provides a molded product free from stickiness due to bleeding out.

Polypropylene resin is mainly a resin excellent in heat resistance and rigidity, is rich in economic efficiency and molding processability, and is suitable for environmental problems. Conventionally, various industrial materials such as automobile materials and packaging materials and Widely used as daily necessities or textile materials.
On the other hand, since its melting point is relatively high, in general, when flexibility is required, a technique of reducing crystallinity by a technique such as copolymerization of another comonomer is taken. However, if the amount of the comonomer is too large, flexibility is obtained but heat resistance is lost, and the resin becomes sticky, making polymerization and molding difficult. In this case, the comonomer content is usually at most several percent, and it is difficult to provide sufficient flexibility.
As a highly flexible polypropylene resin, a resin composition in which a soft elastomer copolymer is blended with a soft polypropylene resin has also been proposed (see Patent Document 1), but the elastomer compound resin composition is transparent. And insufficient in terms of formability.
In addition, due to the heavy use in a wide range of fields, the demands on the physical properties of polypropylene resins by customers are diversified and sophisticated, and it has excellent heat resistance and excellent transparency and other properties. There is a demand for highly flexible materials.

  For this purpose, a polypropylene-based resin material called a so-called block type reactor TPO, in which crystalline polypropylene is produced in the first step and propylene-ethylene copolymer elastomer is produced in the second step, has been developed. Such a reactor TPO is highly economical and excellent in flexibility, heat resistance and mechanical strength. Most of them are crystalline polypropylene produced in the first step and propylene-ethylene produced in the second step. The copolymer elastomer is phase-separated and exhibits the disadvantage that the transparency is extremely poor. Further, when the Ziegler catalyst is produced using a Ziegler catalyst, since the Ziegler catalyst has a plurality of types of active sites, the crystallinity distribution and molecular weight distribution of the propylene-ethylene copolymer are widened, and the By producing a lot of low molecular weight components, even if the moldability is excellent, the stickiness and bleed out of the product are strongly seen, and the disadvantage that problems such as blocking and appearance defects are easily derived is inevitable (see Patent Document 2) ).

In order to improve this problem, a technique has been proposed in which the intrinsic viscosity of the elastomer, that is, the molecular weight is increased to some extent so as to suppress the formation of low molecular weight components (see Patent Document 3). Since the generation of sexual components is not suppressed, the transparency is not sufficient, stickiness and bleed-out are still insufficient, and the high molecular weight of the elastomer results in appearance defects such as blisters and fish eyes. Since it becomes easy and extrudability deteriorates, there is a problem that an organic peroxide must be used in the granulation step.
As another method for improving flexibility, a composition for suppressing bleeding out by adding other additives such as a mineral oil softener and silicon dioxide to an elastomer blended with an olefin rubber has been proposed ( (See Patent Document 4), and it has not been sufficiently achieved to suppress bleed-out while maintaining transparency.

  By polymerizing polypropylene in the first step and propylene and ethylene in the second step, as a reactor TPO based on a metallocene catalyst that has been used after the reactor TPO produced using a Ziegler-based catalyst, A technique has been proposed to obtain a propylene copolymer with good flexibility that shows a specific elution pattern in temperature-temperature elution fractionation, and it has no stickiness due to its narrow molecular weight distribution and crystallinity distribution. However, since the crystallinity distribution is not controlled sufficiently narrow in this technique, the stickiness due to bleed-out and the transparency are still insufficient.

By the way, in order to improve moldability in the rubber material field, so-called process oil is widely used as an additive, but it is also used as a plasticizer in polypropylene resins (see Patent Document 6).
A technique for improving the flexibility of polypropylene resins by using such process oil as a softener has also been developed, and a technique for adding flexibility and heat resistance by blending process oil into a specific polypropylene resin and elastomer composition (See Patent Document 7), and a method of improving flexibility and stickiness by blending a naphthenic process oil with a composition of a polypropylene resin and an olefin-aromatic vinyl copolymer (see Patent Document 8), etc. However, even in these methods, even if flexibility is improved, other properties such as heat resistance and transparency have not been improved in a well-balanced manner.

  As described above, various methods for improving flexibility in polypropylene resins have been proposed, but heat resistance and transparency are well improved in a well-balanced manner along with flexibility, and stickiness is reduced and blocking resistance is reduced. It is difficult to obtain a polypropylene-based resin material that can be imparted at a high level, and depending on the specific application, a higher degree of flexibility is desired.

Japanese Patent Laid-Open No. 3-168233 (Claims) Japanese Patent Publication No. 3-17846 (Claim 1) Japanese Patent Laid-Open No. 9-324022 (claim 1) JP-A-5-287132 (summary) JP 2000-239462 (Abstract, Claim 4) JP-A-9-104801 (summary) JP-A-9-188787 (abstract, paragraph 0005) JP 2002-194153 A (summary)

  From the current state of the art, the demands on the physical properties of polypropylene-based resins are diversifying and sophisticated, and it is necessary to improve flexibility and improve properties such as heat resistance and transparency. There is also a demand for highly flexible materials, and the various improved techniques presented so far do not fully meet these needs and demands. , To obtain a polypropylene-based resin material whose flexibility is remarkably improved, heat resistance and transparency are well improved in a balanced manner, stickiness is also reduced, and blocking resistance is imparted at a high level. This is a problem to be solved by the invention.

The inventors of the present application need to improve the flexibility of the polypropylene resin by using process oil, as described in the paragraph 0006 as the prior art, because a special improvement in flexibility is indispensable to solve such a problem. Although the method was considered effective, in order to improve the heat resistance and transparency in a well-balanced manner and to reduce the stickiness, the method has high heat resistance and flexibility, transparency and stickiness. A specific propylene-based resin having characteristics that are particularly excellent in properties and the like is required.
On the other hand, the inventors of the present application have previously had a specific component composition, molecular weight distribution, crystallinity distribution, and the like by a specific manufacturing method, and also have solid viscoelastic characteristics and elution characteristics in a temperature rising elution fractionation method. -A series of research and development on ethylene random block copolymers has been conducted and an application has been filed as an earlier invention (Japanese Patent Application No. 2003-371458 and others). However, such propylene-ethylene random block copolymers are processed using process oil. As a result, it is possible to realize a propylene-based resin material in which heat resistance and transparency are sufficiently improved in a well-balanced manner and the stickiness is reduced. The present invention has been invented.

The present invention is a polypropylene resin composition in which a process oil for enhancing flexibility is blended with the above-mentioned specific propylene-ethylene random block copolymer, but a specific component composition and molecular weight distribution by a specific production method Propylene-ethylene random block copolymer that has crystallinity distribution, etc. and also has solid viscoelastic properties and elution characteristics in temperature rising elution fractionation method, etc. As a result, the heat resistance and transparency were well improved in a well-balanced manner, and stickiness and bleed out were reduced.
The softness of the process oil is added to the high flexibility of a specific propylene-ethylene random block copolymer, and the flexibility is significantly improved. This feature is demonstrated from the comparison of Examples and Comparative Examples described later. Has been.

  Specifically, the specific propylene-ethylene random block copolymer is a propylene-ethylene random block copolymer obtained by sequential polymerization using a metallocene catalyst, and has an ethylene content of 1 in the first step. Low crystalline or amorphous propylene-ethylene random copolymer containing ˜7 wt% crystalline propylene-ethylene random copolymer component containing 30-70 wt% ethylene in the second step and 6-15 wt% more ethylene than the first step. In the temperature-loss tangent (tan δ) curve obtained by sequentially polymerizing 70 to 30 wt% of the polymer component and obtained by solid viscoelasticity measurement (DMA), the tan δ curve is a copolymer having a single peak at 0 ° C. or lower. The resin composition of the present invention comprises 99 to 70 wt% of the copolymer and 1 to 30 wt% of a process oil component, Furthermore, it is a polypropylene resin composition characterized in that the flexural modulus of the molded product is 250 MPa or less.

The present invention has a main additional requirement of a temperature of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent in order to further improve flexibility and sufficiently ensure heat resistance and transparency in a well-balanced manner. In the TREF elution curve obtained as a plot of elution amount (dWt% / dT) against temperature by temperature rising elution fractionation method (TREF) in the range, the elution peak is specified, and peak T (A1) observed on the high temperature side Is in the range of 65 to 95 ° C., the peak T (A2) observed on the low temperature side is 45 ° C. or lower, or the peak T (A2) is not observed and the temperature T (A4) at which 99 wt% is eluted is 98 ° C. or lower, the temperature difference ΔT (T (A4) −T (A1)) from the peak T (A1) to T (A4) is 5 ° C. or lower, and in the TREF elution curve, Temperature T (A3) at the midpoint of both peaks of T (A1) and T (A2) (when component (A2) does not show a peak, T (A2) is -15 ° C., which is the lower limit of measurement temperature). The ratio H (A3) / H (A1) of the elution amount H (A3) in T and the elution amount H (A1) in T (A1) is defined to be 0.1 or less.
Other additional requirements include selection of process oil, specification of flexural modulus of copolymer, weight average molecular weight of copolymer, and identification of intrinsic viscosity of xylene soluble component at 23 ° C. Out.

  In addition, in the conventional technology of blending process oil with polypropylene resin, adding too much process oil, which is a softening agent, causes bleed out and causes stickiness. Even if a process oil is added to a propylene-based block copolymer, which is also called a polypropylene homopolymer, a random copolymer, or an impact copolymer, which has a relatively high modulus of elasticity, within a range without bleed out, a so-called elastomer It has been difficult to increase the flexibility by achieving a low elastic modulus in a region called “A”. Therefore, in order to obtain a highly flexible resin composition having a lower elastic modulus, it was necessary to use a resin having a lower elastic modulus than the conventional polypropylene-based resin, but such a low elastic modulus. As described above in the background art, it has been difficult for polypropylene-based resins to have high transparency and blocking resistance at the same time.

  As described above, the present invention has a basic composition of the invention of a composition in which process oil is blended with a novel and unique propylene-ethylene random block copolymer. Is an invention that has sufficiently solved the current problem in the polypropylene resin described in paragraph 0007, and is not suggested by the prior art using the process oil described in paragraph 0006. It is clear that it is an invention.

  In the above, the background of the creation of the invention of the present application and the main configuration and features of the invention have been described in general. When the overall configuration of the invention of the present application is clarified collectively, the present invention comprises the following invention unit groups. The invention described in [1] is a basic invention, and [2] the following inventions add or require additional requirements to the basic invention.

[1] A propylene-ethylene random block copolymer obtained by sequential polymerization using a metallocene-based catalyst as component (A), wherein the propylene-ethylene random block copolymer has an ethylene content of 1 to 7 wt% in the first step. 30 to 70 wt% of ethylene random copolymer component, 70 to 30 wt% of low crystalline or amorphous propylene-ethylene random copolymer component containing 6 to 15 wt% more ethylene than the first step in the second step 99 to 70 wt% of a propylene-ethylene random block copolymer that is sequentially polymerized and satisfies the following condition (i), and contains 1 to 30 wt% of a process oil component as a component (B), and has a flexural modulus of elasticity. A polypropylene resin composition having a pressure of 250 MPa or less.
(I) In the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA), the tan δ curve has a single peak at 0 ° C. or lower.
[2] The polypropylene resin composition according to [1], wherein the component (B) is a paraffinic oil having a weight average molecular weight of 200 to 2,000.
[3] The polypropylene resin composition according to [1] or [2], wherein the flexural modulus of the component (A) alone is 450 MPa or less.
[4] The polypropylene resin composition according to any one of [1] to [3], wherein the component (A) satisfies the following conditions (ii) and (iii):
(Ii) TREF elution curve obtained as a plot of elution amount (dWt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. , The peak T (A1) observed on the high temperature side is in the range of 65 to 95 ° C., the peak T (A2) observed on the low temperature side is below 45 ° C., or the peak T (A2) is observed The temperature T (A4) at which 99 wt% elutes is 98 ° C. or less, and the temperature difference ΔT (T (A4) −T (A1)) from the peak T (A1) to T (A4) is 5 ° C. or less. There is.
(Iii) Both peaks of peaks T (A1) and T (A2) in the TREF elution curve (when component (A2) does not show a peak, T (A2) is −15 ° C., which is the lower limit of the measurement temperature). The ratio H (A3) / H (A1) of the elution amount H (A3) at the temperature T (A3) at the midpoint between and the elution amount H (A1) at T (A1) is 0.1 or less.
[5] The polypropylene resin composition according to any one of [1] to [4], wherein the component (A) satisfies the following conditions (iv) and (v):
(Iv) The weight average molecular weight Mw obtained by gel permeation chromatography (GPC) measurement is in the range of 100,000 to 400,000, and the component weight W having a weight average molecular weight of 5,000 or less is 0.8 wt. % Or less.
(V) The intrinsic viscosity [η] cxs measured in 135 ° C. decalin of the 23 ° C. xylene soluble component is in the range of 1 to 2 (dl / g).
[6] A film, sheet or molded product obtained by molding the polypropylene resin composition according to any one of [1] to [5].

The polypropylene-based resin composition of the present invention has exceptionally improved flexibility, and has been well improved in a well-balanced manner such as heat resistance and transparency. Further, the stickiness is reduced and blocking resistance is imparted at a high level. The
Therefore, it is possible to sufficiently meet the diversified and sophisticated demands on the physical properties of polypropylene resins, derived from the heavy use of polypropylene resins in a wide range of fields, and films, sheets and various molded products For example, a plastic material that is very useful industrially can be used.

Hereinafter, in order to describe the invention group in the present invention in detail, embodiments of the invention will be described in detail.
1. About resin composition (1) Component of composition The present invention is a specific propylene-ethylene random block copolymer 99-70% by weight obtained by sequential polymerization using a metallocene catalyst as component (A). And as a component (B), it is a polypropylene-type resin composition which consists of 1-30 weight% of process oils. Other components other than the component (A) and the component (B) may be contained.
The propylene-ethylene random block copolymer is a crystalline propylene-ethylene random copolymer component (referred to as “component (A1)”) and a low crystalline or amorphous propylene-ethylene random copolymer. This is a block copolymer under a common name, which is obtained by sequentially polymerizing a combined component (referred to as “component (A2)”).
This block copolymer is a polymer or a mixture of copolymers produced at each stage, and is generally called a propylene block copolymer.

Process oil is a component that imparts flexibility to the resin composition, and the ratio of the process oil to the entire composition is 1 to 30 wt%, preferably 2 to 25 wt%, and more preferably 3 to 23 wt%. If the amount is less than 1 wt%, sufficient flexibility cannot be obtained, and if it exceeds 30 wt%, the process oil bleeds out and stickiness occurs.
Therefore, the ratio of the propylene-ethylene random block copolymer to the whole composition is 99 to 70 wt%, preferably 98 to 75 wt%, more preferably 97 to 77 wt%.

(2) Flexural modulus of composition The resin composition of the present invention is a polypropylene-based resin composition with excellent flexibility, characterized in that the flexural modulus (FM) of the molded product is 250 MPa or less. .
The bending elastic modulus of the composition does not need to have a lower limit, but is preferably 1 MPa or more, more preferably 5 MPa or more. If it is less than 1 MPa, for example, a cutting failure occurs during pelletization, and production is substantially difficult.
The flexural modulus was measured in accordance with JIS K-7171 (ISO178) by punching out a test piece having a thickness of 2.0 mm, a width of 25.0 mm, and a length of 40.0 mm from a 2 mm thick sheet obtained by injection molding. Shall.

2. Propylene-ethylene random block copolymer component (A) (1) Basic rules of component (A) The main component in the present invention is a random block of propylene and ethylene obtained by sequential polymerization using a metallocene catalyst. 30% to 70% by weight of a crystalline propylene-ethylene random copolymer component (A1) having a content of ethylene of 1 to 7 wt% or less in the first step. The second step was obtained by sequentially polymerizing 70 to 30 wt% of a low crystalline or amorphous propylene-ethylene random copolymer component (A2) containing 6 to 15 wt% more ethylene than the first step. It is a propylene-ethylene random block copolymer.
The crystallinity of component (A1) is a propylene-ethylene random copolymer having high stereoregularity and relatively low ethylene in the copolymer, and low crystallinity or amorphousness of component (A2) is TREF. In various methods for evaluating crystallinity such as the above, it means a polymer whose crystallinity is lower than that of component (A1) or whose crystallinity cannot be observed.
In addition, the propylene-ethylene random copolymer produced in each polymerization step is a polymer in which propylene and ethylene are randomly copolymerized, each having a different ethylene content.

Such a block copolymer component (A) needs to have a solid viscoelastic behavior described in detail in paragraph 0044. For this reason, it is preferable to narrowly control the composition distribution of each component. It is necessary to carry out sequential multistage polymerization using a metallocene catalyst.
The propylene-ethylene random block copolymer component (A) is a so-called block copolymer obtained by sequentially polymerizing a component (A1) and a component (A2) having different crystallinity, and is defined by solid viscoelasticity measurement (DMA). Having a single phase.
Further, as described in detail in paragraphs 0040-0043, it has a specific crystallinity distribution defined by an elution curve of a temperature rising elution fractionation method (TREF), which is defined by the component (A). It is preferable because it can exhibit excellent flexibility, heat resistance and high transparency, and the conventional polyolefin resin cannot satisfy all of them at the same time. It is necessary to have a crystalline distribution, and in order to realize this, it is necessary to use a specific block copolymer composed of components (A1) and (A2) having different crystallinity.

(2) Ethylene content [E] A1 in component (A1)
The crystalline propylene-ethylene random copolymer component (A1) produced in the first step is a component mainly responsible for the heat resistance of the block polymer and has an ethylene content of 1 to 7 wt%, and the component (A1) When the ethylene content [E] A1 in the content is less than 1 wt%, the crystallinity of the random block copolymer becomes high and the flexibility becomes insufficient. When the ethylene content exceeds 7 wt%, the crystallinity becomes too low and the heat resistance and blocking resistance are deteriorated.

(3) Ethylene content [E] A2 in component (A2)
The low crystalline or amorphous propylene-ethylene random copolymer component (A2) produced in the second step is a component necessary for improving the flexibility, transparency and impact resistance of the block copolymer. It is.
In order for the component (A2) to fully exhibit the above-described effects, it is necessary that the ethylene content is in the following specific range.

That is, in the block copolymer component of the present invention, the lower the crystallinity of the component (A2) with respect to the component (A1), the greater the flexibility improvement effect, and the crystallinity is the ethylene content in the propylene-ethylene random copolymer. Therefore, if the ethylene content [E] A2 in the component (A2) is not more than 6 wt% higher than the ethylene content [E] A1 in the component (A1), the effect is not sufficient, preferably 7 wt% % Or more, more preferably 8 wt%, should contain more ethylene than component (A1).
Here, when the difference in ethylene content between the component (A1) and the component (A2) is defined as [E] gap (= [E] A2- [E] A1), [E] gap is 6 wt% or more, preferably 7 wt% % Or more, more preferably 8 wt% or more.

On the other hand, if the ethylene content is increased too much to lower the crystallinity of the component (A2), the difference [E] gap in the ethylene content between the component (A1) and the component (A2) becomes too large and the matrix and domain are separated. The phase separation structure is taken, and the transparency is remarkably deteriorated.
This is because polypropylene originally has low compatibility with polyethylene, and even in a propylene-ethylene random copolymer, the compatibility of both components having different ethylene contents decreases as the difference in ethylene content increases.
Therefore, the upper limit of [E] gap may be in a range where the peak of tan δ is single by solid viscoelasticity measurement described later. For that purpose, [E] gap is 15 wt% or less, preferably 14 wt% or less. More preferably, it should be in the range of 13 wt% or less.

(4) Ratio of components (A1) and (A2) in the random block copolymer When the ratio W (A1) of component (A1) in the random block copolymer component is too large, flexibility and transparency are obtained. Deteriorating, and accordingly, the transparency and flexibility of the entire composition are hindered. Therefore, the ratio of the component (A1) is 70 wt% or less, preferably 60 wt% or less.
On the other hand, if the proportion of the component (A1) becomes too small, the stickiness increases and the heat resistance is remarkably deteriorated. Therefore, the proportion of the component (A1) is 30 wt% or more, preferably 40 wt% or more.
Correspondingly, the lower limit of the proportion W (A2) of the component (A2) in the random block copolymer component is 30 wt% or more, preferably 40 wt% or more, and the upper limit is 70 wt% or less, preferably 60 wt%. If the amount is less than 30 wt%, it cannot sufficiently contribute to flexibility, and if it exceeds 70 wt%, the stickiness becomes remarkable, which is not preferable.

(5) Specific by temperature-temperature elution fractionation (TREF) The method for evaluating the crystallinity distribution of a propylene-ethylene random block copolymer by TREF is well known to those skilled in the art. Detailed measurement method is shown in.
G. Glockner, J. et al. Appl. Polym. Sci. : Appl. Po
lym. Symp. 45, 1-24 (1990)
L. Wild, Adv. Polym. Sci. 98, 1-47 (1990)
J. et al. B. P. Soares, A .; E. Hamielec, Polymer; 36,
8, 1639-1654 (1995)
In TREF measurement, the lower the crystallinity, the lower the elution, and the higher the crystallinity, the higher the elution, so it is possible to accurately grasp the distribution of the crystallinity of the polypropylene resin. .
The propylene-ethylene random block copolymer in the present invention has a large difference in crystallinity of each of the components (A1) and (A2), and each crystallinity distribution is produced by using a metallocene catalyst. Since it is narrow, there are very few intermediate components of both components, and both components can be accurately separated by TREF.

Specifically, TREF obtained as a plot of elution amount (dWt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. In the elution curve, components (A1) and (A2) show their elution peaks at T (A1) and T (A2), respectively, due to the difference in crystallinity, and the difference is sufficiently large, so the intermediate temperature T (A3) ( = {T (A1) + T (A2)} / 2).
The lower limit of the TREF measurement temperature is −15 ° C. in the apparatus used for this measurement. However, when the crystallinity of the component (A2) is very low or an amorphous component, There may be no peak in the range. (At this time, the concentration of the component (A2) dissolved in the solvent is detected at the measurement temperature lower limit (ie, −15 ° C.).) In this case, T (A2) is considered to exist below the measurement temperature lower limit. However, since the value cannot actually be measured, T (A2) is defined as −15 ° C. which is the lower limit of the measurement temperature.

Here, if the integrated amount of the component eluted before T (A3) is defined as W (A2) wt%, and the integrated amount of the component eluted at T (A3) or higher is defined as W (A1) wt%, W (A2) Almost corresponds to the amount of the low-crystalline or amorphous component (A2), and the integrated amount W (A1) of the component eluted at T (A3) or higher is a component with relatively high crystallinity ( Almost corresponds to the amount of A1).
In addition, the example of a TREF elution curve is illustrated in FIG. 1 about the propylene-ethylene random block copolymer in Example 1 (manufacture example 1).

In the present invention, TREF is specifically measured as follows.
A sample is dissolved in o-dichlorobenzene (containing 0.5 mg / mL BHT) at 140 ° C. to obtain a solution. This is introduced into a 140 ° C. TREF column, cooled to 100 ° C. at a rate of 8 ° C./min, subsequently cooled to −15 ° C. at a rate of 4 ° C./min, and held for 60 minutes. Thereafter, o-dichlorobenzene (containing 0.5 mg / mL BHT) as a solvent is flowed through the column at a flow rate of 1 mL / min, and components dissolved in o-dichlorobenzene at −15 ° C. are eluted in the TREF column for 10 minutes. Next, the column is linearly heated to 140 ° C. at a heating rate of 100 ° C./hour to obtain an elution curve.

(6) Measurement of ethylene content [E] A1 and [E] A2 (a) Separation of components (A) and (B) Based on T (A3) determined by the previous TREF measurement, a preparative separation apparatus was used. Using the temperature rising column fractionation method, the component (A2) of the soluble component at T (A3) and the component (A1) of the insoluble component at T (A3) are fractionated, and the ethylene content of each component is determined by NMR. Ask.
The temperature rising column fractionation method is a measurement method as disclosed in, for example, Macromolecules, 21, 314 to 319 (1988). Specifically, the following method was used in the present invention.

(B) Fractionation condition A cylindrical column having a diameter of 50 mm and a height of 500 mm is filled with a glass bead carrier (80 to 100 mesh) and maintained at 140 ° C. Next, 200 mL of an o-dichlorobenzene solution (10 mg / mL) of the sample dissolved at 140 ° C. is introduced into the column. Thereafter, the temperature of the column is cooled to 0 ° C. at a temperature decreasing rate of 10 ° C./hour. After holding at 0 ° C. for 1 hour, the column temperature is heated to T (A3) at a heating rate of 10 ° C./hour and held for 1 hour. Note that the temperature control accuracy of the column through a series of operations is ± 1 ° C.
Next, while maintaining the column temperature at T (A3), 800 mL of o-dichlorobenzene of T (A3) is allowed to flow at a flow rate of 20 mL / min, so that components soluble in T (A3) existing in the column can be obtained. Elute and collect.
Next, the column temperature is increased to 140 ° C. at a temperature rising rate of 10 ° C./hour, and left at 140 ° C. for 1 hour, and then 800 mL of a 140 ° C. solvent (o-dichlorobenzene) is flowed at a flow rate of 20 mL / min. , T (A3) is eluted and recovered.
The solution containing the polymer obtained by fractionation is concentrated to 20 mL using an evaporator and then precipitated in 5 times the amount of methanol. The precipitated polymer is recovered by filtration and then dried overnight in a vacuum dryer.

(C) Measurement of ethylene content by ¹³ C-NMR The ethylene content of each of the components (A1) and (A2) obtained by the above fractionation was measured by the proton complete decoupling method according to the following conditions. ¹³ C-NMR Obtained by analyzing the spectrum.
Model: GSX-400 manufactured by JEOL Ltd. or equivalent equipment (carbon nuclear resonance frequency of 100 MHz or more)
Solvent: o-dichlorobenzene: heavy benzene = 4: 1 (volume ratio)
Concentration: 100 mg / mL
Temperature: 130 ° C
Pulse angle: 90 °
Pulse interval: 15 seconds Integration count: 5,000 times or more The attribution of the spectrum may be performed with reference to, for example, Macromolecules, 17 , 1950 (1984). The attribution of spectra measured under the above conditions is as shown in the table below. Symbols such as S _αα in the table follow the notation of Carman et al. (Macromolecules, 10 , 536 (1977)), P represents a methyl carbon, S represents a methylene carbon, and T represents a methine carbon.

Hereinafter, when “P” is a propylene unit in a copolymer chain and “E” is an ethylene unit, six types of triads of PPP, PPE, EPE, PEP, PEE and EEE may exist in the chain. As described in Macromolecules, 15 , 1150 (1982), the concentration of these triads and the peak intensity of the spectrum are linked by the following relational expressions (1) to (6).
[PPP] = k × I (T _ββ ) (1)
[PPE] = k × I (T _βδ ) (2)
[EPE] = k × I (T _δδ ) (3)
[PEP] = k × I (S _ββ ) (4)
[PEE] = k × I (S _βδ ) (5)
[EEE] = k × {I (S _δδ ) / 2 + I (S _γδ ) / 4} (6)
Here, [] indicates the fraction of triads, for example, [PPP] is the fraction of PPP triads in all triads. Therefore,
[PPP] + [PPE] + [EPE] + [PEP] + [PEE] + [EEE] = 1 (7)
It is. Further, k is a constant, I indicates the spectral intensity, and for example, I (T _ββ ) means the intensity of the peak at 28.7 ppm attributed to T _ββ .
By using the relational expressions (1) to (7) above, the fraction of each triad is obtained, and the ethylene content is obtained from the following expression.
Ethylene content (mol%) = ([PEP] + [PEE] + [EEE]) × 100
In addition, the propylene random copolymer of the present invention contains a small amount of a propylene hetero bond (2,1-bond and / or 1,3-bond), thereby producing the following minute peak.

In order to obtain an accurate ethylene content, it is necessary to include these peaks derived from heterogeneous bonds in the calculation, but it is difficult to completely separate and identify the peaks derived from heterogeneous bonds. Since it is a small amount, the ethylene content of the present invention should be determined using the relational expressions (1) to (7) as in the analysis of the copolymer produced with a Ziegler catalyst that does not substantially contain a heterogeneous bond. And
Conversion from mol% to wt% of ethylene content is performed using the following formula.
Ethylene content (% by weight) = (28 × X / 100) / {28 × X / 100 + 42 × (1−X / 100)} × 100 where X is the ethylene content in mol%.
In addition, the ethylene content [E] W of the entire block copolymer is the components (A1) and (A2) measured from the above, and each component calculated from the respective ethylene contents [E] A1, [E] A2 and TREF The weight ratio W (A1) and W (A2) wt% is calculated by the following formula.
[E] W = {[E] A1 × W (A1) + [E] A2 × W (A2)} / 100 (wt%)

(7) Additional requirement of crystallinity distribution by TREF elution curve By using the TREF elution curve used for specifying the component amount of each component, etc., additional in the crystallinity distribution of component (A) of the present invention. Special features can be found.
(A) Elution peak temperature T (A1)
The higher the elution peak temperature T (A1) of the component (A1) in the TREF elution curve, the higher the crystallinity and the heat resistance of the component (A1). At this time, the crystallinity of the component (A1) increases. The component (A2) required for improving the flexibility and transparency of the random block copolymer must be increased.
On the other hand, if the proportion of the component (A2) is too large, stickiness and heat resistance are deteriorated. Therefore, in order to improve the balance between flexibility and transparency, T (A1) should not be too high. Preferably it is 95 degrees C or less, More preferably, it is 90 degrees C or less, More preferably, it is 88 degrees C or less.
If T (A1) is too low, the composition cannot exhibit sufficient heat resistance, and stickiness and bleed-out deteriorate, so it is necessary that the temperature be 65 ° C. or higher.

(B) Elution end temperature T (A4)
Even if T (A1) is low, when the crystallinity distribution is on the high crystal side, the transparency is deteriorated. Therefore, it is preferable to suppress the crystallinity spread to the high temperature side in the TREF elution curve. This broadening of crystallinity toward the high crystal side defines the elution end temperature T (A4) of the entire random block copolymer with respect to the peak temperature T (A1). Therefore, in the present invention, it is desirable that the temperature at which 99 wt% of the total elutes is defined as the elution end temperature T (A4)) is not high. As a desirable requirement of the present invention, T (A4) is 98 ° C or lower, preferably 93 ° C or lower, more preferably 90 ° C or lower.
The temperature difference T (A4) -T (A1) from the elution peak T (A1) to the end is 5 ° C. or less, preferably 4 ° C. or less, more preferably 3 ° C. or less.

(C) Elution peak temperature T (A2)
On the other hand, if the crystallinity of the component (A2) is not sufficiently lowered, the flexibility and transparency of the random block copolymer component cannot be secured, so T (A2) is 45 ° C. or less, preferably 40 ° C. It is as follows.

(D) Elution ratio H (A3) / H (A1)
If there are many components having an intermediate crystallinity between components (A1) and (A2), both components may exhibit heat resistance deterioration due to co-crystallization, so there are few intermediate components between the two components. Better.
Here, the ratio of the intermediate component between the two components is the elution amount H (A3) dwt% / dT at the temperature T (A3) intermediate between T (A1) and T (A2), and the elution amount at T (A1). It can be evaluated by the ratio H (A3) / H (A1) of H (A1) dwt% / dT. In the present invention, H (A3) / H (A1) is preferably 0.1 or less.

(8) Definition by solid viscoelasticity measurement (tan δ peak) In the present invention, in the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA), tan δ has a single peak at 0 ° C. or less. It is necessary to have.
When the random block copolymer has a phase separation structure, the glass transition temperature of the amorphous part contained in the component (A1) is different from the glass transition temperature of the amorphous part contained in the component (A2). Are plural. In this case, there arises a problem that the transparency is remarkably deteriorated.
Whether or not the phase separation structure is taken can be discriminated in the tan δ curve in the solid viscoelasticity measurement, and avoidance of the phase separation structure that affects the transparency of the molded product has a single peak at tan δ of 0 ° C. or less. Is brought about by
In order to obtain a highly transparent resin composition as in the present invention, it is necessary that the random block copolymer alone, which is a constituent component, has good transparency, and the copolymer alone has a Haze value. Is preferably less than 60. At this time, the Haze value is a measurement value in a test piece having a thickness of 2 mm obtained by injection molding.
As an example of what is compatible, FIG. 2 shows an example of the peak of the tan δ curve for the propylene-ethylene random block copolymer in Example 1 (Production Example 1). As an example of the phase separation, FIG. 3 shows an example of the peak of the tan δ curve for the propylene-ethylene random block copolymer in Comparative Example 7 (Production Example 5).

  Specifically, solid viscoelasticity measurement is performed by applying a sinusoidal strain of a specific frequency to a strip-shaped sample piece and detecting the generated stress. Here, the frequency is 1 Hz, and the measurement temperature is raised stepwise from −60 ° C. until the sample is melted and cannot be measured. Further, it is recommended that the magnitude of distortion is about 0.1 to 0.5%. From the obtained stress, the storage elastic modulus and the loss elastic modulus are obtained by a known method, and the loss tangent (= loss elastic modulus / storage elastic modulus) defined by the ratio thereof is plotted against the temperature. A sharp peak is shown in the temperature region. In general, the peak of tan δ at 0 ° C. or lower is for observing the glass transition of the amorphous part, and here, this peak temperature is defined as the glass transition temperature Tg (° C.). The lower limit of the peak temperature is not particularly required, but usually the peak appears at a temperature higher than −20 ° C. when the material components are in the compatible range.

(9) Flexural modulus The propylene-ethylene random block copolymer component (A) of the present invention has a flexural modulus alone of 450 MPa or less, preferably 400 MPa or less, more preferably 350 MPa or less. It is preferable when producing a resin composition rich in.

(10) Molecular Weight (a) Additional Requirements for Molecular Weight The random block copolymer component in the present invention has an additional feature that the low molecular weight component is small. It is considered that a low molecular weight component, particularly a component whose molecular weight is less than the molecular weight between the entanglement points, bleeds out to the surface of the molded article, and deteriorates stickiness and transparency.
The molecular weight between the entanglement points of polypropylene is about 5,000, as described in Journal of Polymer Science: Part B: Polymer Physics; 37, 1023-1033 (1999).
Therefore, the block copolymer in the present invention has a low molecular weight component, and the weight average molecular weight of 5,000 or less is 0.8 wt% or less, preferably 0.5 wt% or less. .
The lower limit of the weight average molecular weight is not particularly limited, but if the molecular weight is too low in the range where the component of Mw ≦ 5,000 does not exceed 0.8 wt%, a problem of moldability and a decrease in strength occur. , Preferably in the range of 1,000 or more. The upper limit is 400,000, and if it is more than this, the moldability and the like are lowered.

(B) Molecular weight measurement In the present invention, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are those measured by gel permeation chromatography (GPC).
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 0.2 mL of a solution dissolved in o-dichlorobenzene (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. In the viscosity formula [η] = K × M ^α used for conversion to molecular weight, the molecular weight is converted to polypropylene using the following numerical values.
PS: K = 1.38 × 10 ⁻⁴ α = 0.7
PP: K = 1.03 × 10 ⁻⁴ α = 0.78
The measurement conditions for GPC are as follows.
Equipment: GPC (ALC / GPC 150C) manufactured by WATERS
Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.4)
2μm)
Column: AD806M / S (3 pieces) manufactured by Showa Denko KK
Mobile phase solvent: ο-dichlorobenzene Measurement temperature: 140 ° C
Flow rate: 1.0 ml / min Injection volume: 0.2 ml
Sample Preparation Prepare a 1 mg / mL solution using o-dichlorobenzene (containing 0.5 mg / mL BHT) and dissolve it at 140 ° C. for about 1 hour.
The amount of the component having a molecular weight of 5,000 or less can also be determined from a plot of the elution ratio with respect to the molecular weight obtained by GPC measurement.

(11) Intrinsic viscosity [η] cxs
In the random block copolymer component, stickiness and bleed out are particularly problematic because it is a component soluble in xylene at room temperature (CXS component), and the measurement of intrinsic viscosity [η] (dl / g) It is preferable to carry out for the CXS component.
Here, the CXS component was prepared by dissolving a random block copolymer in p-xylene at 130 ° C. to form a solution, and then leaving it at 25 ° C. for 12 hours, separating the precipitated polymer by filtration, and evaporating p-xylene from the filtrate. The intrinsic viscosity [η] cxs of the obtained CXS component can be measured by using an Ubbelohde viscometer at a temperature of 135 ° C. using decalin as a solvent.

At this time, the random block copolymer of the present invention does not increase the generation of a component having a molecular weight of 5,000 or less, which is likely to bleed out. Therefore, the conventional Ziegler catalyst deteriorates manufacturing problems and blocking. Thus, even if the intrinsic viscosity [η] cxs of the CXS component, which has a practical problem, is in the region of 2 or less, it can be produced and used without causing any particular deterioration in physical properties.
Such a random block copolymer that does not increase the component having a molecular weight of 5,000 or less while lowering the intrinsic viscosity of the CXS component has characteristics in terms of physical properties such as high tensile elongation at break and high tensile strength at break. It shows the effect that there are few occurrences of appearance defects called “butsu” and “fish eyes”.

3. Production method of propylene-ethylene random block polymer component (A) (1) Production with metallocene catalyst
The method for producing the propylene-ethylene random block copolymer component of the present invention requires the use of a metallocene catalyst. 30 to 70 wt% of propylene-ethylene random copolymer containing 1 to 7 wt% ethylene as component (A1) in the first step, and propylene containing 6 to 15 wt% more ethylene than the first step in the second step It is necessary to sequentially polymerize 70-30 wt% of an ethylene random copolymer.
It is well known to those skilled in the art that the propylene-ethylene random copolymer has a wide molecular weight distribution and crystallinity distribution, and the stickiness and bleedout deteriorate. However, the block copolymer component used in the present invention is also sticky In order to suppress bleed out, it is necessary to polymerize using a metallocene-based catalyst having a narrow molecular weight distribution and crystallinity distribution. In the case of a Ziegler catalyst, the excellent propylene-ethylene random block copolymer No coalescence is obtained.

(2) Metallocene-based catalyst The type of the metallocene-based catalyst is not particularly limited as long as it can produce a copolymer having the performance of the present invention, but in order to satisfy the requirements of the present invention, for example, It is preferable to use a metallocene catalyst comprising components (a) and (b) as shown in FIG.
Component (a): At least one metallocene transition metal compound selected from the transition metal compounds represented by the general formula (1) Component (b): At least one selected from the following (b-1) to (b-4) Seed solid
Component (b-1) A particulate carrier carrying an organoaluminoxy compound (b-2) An ionic compound or Lewis acid capable of reacting with component (a) to convert component (a) into a cation Supported particulate carrier (b-3) Solid acid particulate (b-4) Ion exchange layered silicate Component (c): Organoaluminum compound

(I) Component (a)
As the component (a), at least one metallocene transition metal compound selected from transition metal compounds represented by the following general formula (1) can be used.
^{_{Q (C 5 H 4-a}} -aR 1) (C 5 H 4-b -bR 2) MeXY (1)
[Wherein Q represents a divalent linking group that bridges two conjugated five-membered ring ligands, Me represents a metal atom selected from titanium, zirconium, and hafnium, and X and Y represent hydrogen atoms. , A halogen atom, a hydrocarbon group, an alkoxy group, an amino group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group or a silicon-containing hydrocarbon group, and X and Y are each independently, that is, the same or different Good. R ¹ and R ² represent hydrogen, hydrocarbon group, halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing hydrocarbon group, boron-containing hydrocarbon group or phosphorus-containing hydrocarbon group. . a and b are the number of substituents. ]

Specifically, Q represents a divalent linking group that bridges two conjugated five-membered ring ligands. For example, a divalent hydrocarbon group, a silylene group, an oligosilylene group, or a hydrocarbon group as a substituent. Examples thereof include a silylene group or an oligosilylene group, or a germylene group having a hydrocarbon group as a substituent. Among these, preferred is a silylene group having a divalent hydrocarbon group and a hydrocarbon group as a substituent.
X and Y each represents a hydrogen atom, a halogen atom, a hydrocarbon group, an alkoxy group, an amino group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, or a silicon-containing hydrocarbon group. And chlorine, methyl, isobutyl, phenyl, dimethylamide, diethylamide group and the like.
R ¹ and R ² represent hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, an oxygen-containing hydrocarbon group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon group. . Specific examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a phenyl group, a naphthyl group, a butenyl group, and a butadienyl group. In addition, halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing hydrocarbon group, boron-containing hydrocarbon group or phosphorus-containing hydrocarbon group include methoxy group, ethoxy group, phenoxy group, trimethylsilyl group. Typical examples include a group, a diethylamino group, a diphenylamino group, a pyrazolyl group, an indolyl group, a dimethylphosphino group, a diphenylphosphino group, a diphenylboron group, and a dimethoxyboron group. Among these, a hydrocarbon group having 1 to 20 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, and a butyl group are particularly preferable.
By the way, adjacent R ¹ and R ² may combine to form a ring, on which a hydrocarbon group, halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing You may have a substituent which consists of a hydrocarbon group, a boron containing hydrocarbon group, or a phosphorus containing hydrocarbon group.
Me is a metal atom selected from titanium, zirconium and hafnium, preferably zirconium and hafnium.
Among the components (a) described above, preferred for the production of the propylene polymer of the present invention is a substituted cyclopentadienyl group crosslinked with a silylene group, a germylene group or an alkylene group having a hydrocarbon substituent. A transition metal compound comprising a ligand having a substituted indenyl group, a substituted fluorenyl group, or a substituted azulenyl group, and particularly preferably a 2,4-position-substitution bridged by a silylene group or a germylene group having a hydrocarbon substituent It is a transition metal compound comprising a ligand having an indenyl group and a 2,4-position substituted azulenyl group.

Non-limiting specific examples include dimethylsilylene bis (2-methyl-4-phenylindenyl) zirconium dichloride, diphenylsilylene bis (2-methyl-4-phenylindenyl) zirconium dichloride, dimethylsilylene bis (2-methyl). Benzoindenyl) zirconium dichloride, dimethylsilylenebis {2-isopropyl-4- (3,5-diisopropylphenyl) indenyl} zirconium dichloride, dimethylsilylenebis (2-propyl-4-phenanthrylindenyl) zirconium dichloride, dimethyl Silylenebis (2-methyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) azurenyl} zirconium dichloride, dimethylsilylenebi (2-Ethyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis (2-isopropyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis {2-ethyl-4- (2-fluorobiphenyl) azurenyl} zirconium Examples thereof include dichloride, dimethylsilylene bis {2-ethyl-4- (4-t-butyl-3-chlorophenyl) azurenyl} zirconium dichloride, and the like. A compound in which the silylene group of the compound of these specific examples is replaced with a germylene group and zirconium is replaced with hafnium is also exemplified as a suitable compound.
In addition, since the catalyst component is not an important element of the present invention, it avoids complicated listing and is limited to a representative example, but it is obvious that the effective range of the present invention is not limited by this. It is.

(B) Component (b)
As the component (b), at least one solid component selected from the components (b-1) to (b-4) described above is used. Each of these components is known and can be used by appropriately selecting from known techniques. Specific examples and manufacturing methods thereof are described in detail in JP-A No. 2002-284808, JP-A No. 2002-53609, JP-A No. 2002-69116, JP-A No. 2003-105015, and the like.
Here, as the particulate carrier used for the component (b-1) and the component (b-2), inorganic oxides such as silica, alumina, magnesia, silica alumina, silica magnesia, magnesium chloride, magnesium oxychloride, chloride Examples thereof include inorganic halides such as aluminum and lanthanum chloride, and porous organic carriers such as polypropylene, polyethylene, polystyrene, styrene divinyl benzene copolymer, and acrylic acid copolymer.

As a non-limiting specific example of the component (b), as the component (b-1), a fine particle carrier on which methylalumoxane, isobutylalumoxane, methylisobutylalumoxane, aluminum butylboronate tetraisobutyl or the like is supported, As component (b-2), triphenylborane, tris (3,5-difluorophenyl) borane, tris (pentafluorophenyl) borane, triphenylcarbonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium Particulate carrier carrying tetrakis (pentafluorophenyl) borate, etc. as component (b-3), alumina, silica alumina, magnesium chloride, etc. as component (b-4), montmorillonite, zakonite, beidellite, non Tronite, Sa Knight, hectorite, stevensite, bentonite, smectite group such as taeniolite, vermiculite, and the like mica group. These may form a mixed layer.
Particularly preferred among the above components (b) is the ion-exchange layered silicate of component (b-4), and more preferred are chemical treatments such as acid treatment, alkali treatment, salt treatment and organic matter treatment. It is an ion exchange layered silicate applied.

(C) Component (c)
Examples of organoaluminum compounds used as component (c) as needed are:
General formula AlR _a X _3-a
(Wherein R is a hydrocarbon group having 1 to 20 carbon atoms, X is hydrogen, halogen, alkoxy group, a is a number of 0 <a ≦ 3), trimethylaluminum, triethylaluminum, tripropylaluminum, Trialkylaluminum such as triisobutylaluminum or halogen- or alkoxy-containing alkylaluminum such as diethylaluminum monochloride, diethylaluminum monomethoxide. In addition, aluminoxanes such as methylaluminoxane can also be used. Of these, trialkylaluminum is particularly preferred.

(D) Formation of catalyst Component (A) and component (B) and, if necessary, component (c) are brought into contact to form a catalyst. The contact method is not particularly limited, but the contact can be made in the following order. Moreover, this contact may be performed not only at the time of catalyst preparation but also at the time of prepolymerization with olefin or at the time of polymerization of olefin.
1) Contact component (a) and component (b) 2) Add component (c) after contacting component (a) and component (b) 3) Contact component (a) and component (c) 4) Add component (b) after contact 4) Add component (a) after contacting component (b) and component (c) 5) Contact three components simultaneously Component (a) used in the present invention The amount of (b) and (c) used is arbitrary. For example, the amount of component (a) used relative to component (b) is preferably in the range of 0.1 μmol to 1,000 μmol, particularly preferably 0.5 μmol to 500 μmol, relative to 1 g of component (b). The amount of component (c) used relative to component (b) is preferably such that the amount of aluminum metal is 0.001 to 100 mmol, particularly preferably 0.005 to 50 mmol, relative to 1 g of component (b). Therefore, the amount of component (c) to component (a) is preferably in the range of 10 ⁻³ to 10 ⁶ , particularly preferably 10 ⁻² to 10 ⁵ , in terms of the molar ratio of the metal.

(E) Pre-polymerization treatment The catalyst of the present invention is preferably subjected to a pre-polymerization treatment consisting of preliminarily contacting an olefin and polymerizing a small amount. The olefin to be used is not particularly limited, but ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane, styrene and the like can be used. It is possible to use, and it is particularly preferable to use propylene. The olefin can be supplied by any method such as a supply method for maintaining the olefin at a constant speed or in a constant pressure state, a combination thereof, or a stepwise change. The prepolymerization temperature and time are not particularly limited, but are preferably in the range of −20 ° C. to 100 ° C. and 5 minutes to 24 hours, respectively. The amount of prepolymerization is preferably 0.01 to 100, more preferably 0.1 to 50 with respect to the component (b). After completion of the prepolymerization, the catalyst can be used as it is, depending on the usage form of the catalyst. However, if necessary, drying can also be performed.
Furthermore, a polymer such as polyethylene, polypropylene, or polystyrene, or an inorganic oxide solid such as silica or titania can be allowed to coexist during or after the contact of the above components.

(3) Polymerization method (A) Sequential polymerization In producing the random block copolymer of the present invention, the crystalline propylene-ethylene random copolymer component (A1) and the low crystalline or amorphous propylene-ethylene random are used. It is necessary to sequentially polymerize the copolymer component (A2).
When the copolymer is simply a random copolymer obtained by copolymerizing ethylene with propylene, if the ethylene content is low, the flexibility and transparency are not sufficient. When it is increased, the heat resistance deteriorates, and it is difficult to satisfy all of these.
Therefore, in the present invention, the copolymer is a block copolymer obtained by sequentially polymerizing components having different ethylene contents in the first step and the second step in order to balance transparency, flexibility and heat resistance. is necessary.
In addition, since the present invention may use a copolymer having a low molecular weight and easily sticking alone as the component (A2), in order to prevent problems such as adhesion to the reactor, the component (A1) is polymerized. It is necessary to use a method of polymerizing component (A2).

When performing sequential polymerization, either a batch method or a continuous method can be used, but it is generally desirable to use a continuous method from the viewpoint of productivity.
In the case of the batch method, it is possible to polymerize the component (A1) and the component (A2) individually using a single reactor by changing the polymerization conditions with time. As long as the effect of the present invention is not hindered, a plurality of reactors may be connected in parallel.
In the case of a continuous process, it is necessary to use a production facility in which two or more reactors are connected in series because it is necessary to individually polymerize the component (A1) and the component (A2), but as long as the effects of the present invention are not impaired. A plurality of reactors may be connected in series and / or in parallel for each of component (A1) and component (A2).

(B) Polymerization process As the polymerization process, any polymerization method such as a slurry method, a bulk method, or a gas phase method can be used. Although it is possible to use supercritical conditions as intermediate conditions between the bulk method and the gas phase method, they are substantially the same as the gas phase method, and are therefore included in the gas phase method without any particular distinction.
Since the low crystalline or amorphous propylene-ethylene random copolymer component (A2) is easily soluble in organic solvents such as hydrocarbons or liquefied propylene, it is desirable to use a gas phase method for the production of the component (A2).
Any process may be used for the production of the crystalline propylene-ethylene random copolymer component (A1), but in the case of producing the component (A1) having a relatively low crystallinity, adhesion, etc. In order to avoid this problem, it is desirable to use a gas phase method.
Therefore, using a continuous method, first, the crystalline propylene-ethylene random copolymer component (A1) is polymerized by a bulk method or a gas phase method, and subsequently a low crystalline or amorphous propylene-ethylene random copolymer elastomer. It is most desirable to polymerize component (A2) by a gas phase method.

(C) Other polymerization conditions The polymerization temperature can be used without any particular problem as long as it is within a commonly used temperature range. Specifically, a range of 0 ° C. to 200 ° C., more preferably 40 ° C. to 100 ° C. can be used.
The polymerization pressure varies depending on the process to be selected, but can be used without any problem as long as it is in a pressure range usually used. Specifically, a range of greater than 0 to 200 MPa, more preferably 0.1 MPa to 50 MPa can be used. In that case, inert gas, such as nitrogen, can also coexist.
When the component (A1) is sequentially polymerized in the first step and the component (A2) is sequentially polymerized in the second step, it is desirable to add a polymerization inhibitor into the system in the second step. In the case of producing a propylene-ethylene block copolymer, if a polymerization inhibitor is added to a reactor that performs ethylene-propylene random copolymerization in the second step, the particle properties (fluidity, etc.) of the resulting powder, gel, etc. Product quality can be improved. Various technical studies have been made on this method, and examples thereof include Japanese Patent Publication No. 63-54296, Japanese Patent Application Laid-Open No. 7-25960, Japanese Patent Application Laid-Open No. 2003-2939, and the like. It is desirable to apply the method to the present invention.

4). Method for controlling component of component (A) Each element of the propylene-ethylene random block copolymer used in the resin composition of the present invention is controlled as follows, and is required for the random block copolymer of the present invention. Can be manufactured to meet the structural requirements.
(1) About component (A1) About crystalline propylene-ethylene random copolymer component (A1), it is necessary to control ethylene content [E] A1 and T (A1).
In the present invention, in order to control [E] A1 within a predetermined range, the amount ratio of propylene and ethylene supplied to the polymerization tank in the first step may be appropriately adjusted. The relationship between the supply ratio and the ethylene content in the resulting propylene-ethylene random copolymer varies depending on the type of metallocene catalyst used, but the component (A1) having the ethylene content [E] A1 required by adjusting the supply ratio is added. Can be manufactured. For example, when [E] A1 is controlled to 0 to 7 Wt%, the supply weight ratio of ethylene to propylene may be in the range of 0 to 0.3, preferably in the range of 0 to 0.2.
At this time, the component (A1) has a narrow crystallinity distribution, and T (A1) decreases as [E] A1 increases. Therefore, in order to satisfy T (A1) within the scope of the present invention, [E] A1 and the relationship between them are grasped and adjusted to take a target range.

(2) Component (A2) For the low crystalline or amorphous propylene-ethylene random copolymer component (A2), it is necessary to control the ethylene content [E] A2, T (A2) and [η] cxs. is there.
In the present invention, in order to control [E] A2 within a predetermined range, the ratio of ethylene supply to propylene in the second step may be controlled as in [E] A1. For example, when [E] A2 is controlled to 5 to 27 wt%, the supply weight ratio of ethylene to propylene may be in the range of 0.01 to 5, preferably in the range of 0.05 to 2.
At this time, although the crystallinity distribution of the component (A2) is slightly increased with the increase of the ethylene content, T (A2) is decreased with the increase of [E] A2 in the same manner as the component (A1). Therefore, in order for T (A2) to satisfy the scope of the present invention, the relationship between [E] A2 and T (A2) is grasped and [E] A2 is controlled to be within a predetermined range. That's fine.

(3) About W (A1) and W (A2) The amount W (A1) of component (A1) and the amount W (A2) of component (A2) are the production amounts of the first step for producing component (A1). It can be controlled by changing the ratio of the production amount in the second step of producing the component (A2). For example, in order to increase W (A1) and decrease W (A2), the production amount of the second step may be reduced while maintaining the production amount of the first step, which shortens the residence time of the second step. It can be easily controlled by lowering the polymerization temperature or increasing the amount of the polymerization inhibitor. The reverse is also true.
When actually setting the conditions, it is necessary to consider the activity decay. That is, in the range of the ethylene contents [E] A1 and [E] A2 carried out in the present invention, generally, when the ratio of ethylene supply to propylene is increased in order to increase the ethylene content, the polymerization activity increases. The activity decay tends to increase. Therefore, in order to maintain the activity of the second step, it is necessary to suppress the polymerization activity of the first step. Specifically, in the first step, the ethylene content [E] A1 is lowered and the production amount W (A1 ), If necessary, lower the polymerization temperature and / or shorten the polymerization time (residence time), or increase the ethylene content [E] A2 in the second step and increase the production W (A2) If necessary, the conditions may be set by a method that raises the polymerization temperature and / or lengthens the polymerization time (residence time).

(4) Glass transition temperature Tg In the propylene-ethylene random block copolymer component of the present invention, the glass transition temperature Tg needs to have a single peak. In order for Tg to have a single peak, the difference between the ethylene content [E] A1 in component (A1) and the ethylene content [E] A2 in component (A2) [E] gap (= [E ] A2- [E] A1) is made 15 wt% or less, preferably 14 wt% or less, more preferably 13 wt% or less, and [E] gap may be reduced to a range where Tg becomes a single peak in actual measurement.
Depending on the ethylene content [E] A1 of the crystalline copolymer component (A1), the ethylene content [E] A2 of the low crystalline or amorphous copolymer component (A2) is within an appropriate range. By setting the supply weight ratio of ethylene to propylene during the polymerization of component (A2), it is possible to obtain a polymer having a predetermined [E] gap.

The Tg of the block copolymer that does not take a phase separation structure as in the present invention is the ethylene content [E] A1 in the component (A1), the ethylene content [E] A2 in the component (A2), and both. It is affected by the quantity ratio of the components. In the present invention, the amount of the component (A2) is 30 to 70 wt%, but in this range, Tg is more strongly affected by the ethylene content [E] A2 in the component (A2).
That is, Tg reflects the glass transition of the amorphous part. In the block copolymer component of the present invention, the component (A1) has crystallinity and relatively few amorphous parts, whereas the component (A2 ) Is low crystalline or amorphous, most of which is amorphous.
Therefore, the value of Tg is almost controlled by [E] A2, and the control method of [E] A2 is as described above in paragraph 0066.

(5) Molecular weight The propylene-ethylene random block copolymer of the present invention is a low crystalline or amorphous component that causes problems due to particular stickiness when bleeded out by specifying the catalyst and polymerization conditions. In addition, the formation of low molecular weight components can be suppressed, and the intrinsic viscosity of low crystalline or amorphous components can also be lowered.
In the propylene-ethylene random block copolymer of the present invention, in order to maintain transparency, the compatibility of the crystalline copolymer component (A1) and the low crystalline or amorphous copolymer component (A2) is improved. Since the viscosity [η] A1 of the component (A1), the viscosity [η] A2 of the component (A2), and the viscosity [η] W of the entire propylene-ethylene random block copolymer component are The apparent viscosity mixing rule is generally established. That is,
Log [η] W = {W (A1) × Log [η] A1 + W (A2) × Log [η] A2} / 100
Is generally established. In general, there is a certain correlation between Mw and [η], so from the viewpoint of flexibility and heat resistance, [η] A2, W (A1), and W (A2) are set first. Mw can be controlled freely by changing [η] A1 according to the above equation.

(6) About H (A3) and T (A4) H (A3) and T (A4) are both indices indicating crystallinity distribution. As the crystallinity distribution of component (A1) is narrower, T (A4) is closer (lower) to T (A1), and the crystallinity distributions of both component (A1) and component (A2) are both narrower. The larger the difference, the smaller the value of H (A3). That is, controlling H (A3) to be small and T (A4) to be low is nothing but controlling the crystallinity distribution of the components (A1) and (A2) to be narrow.
In general, by using a metallocene catalyst, a polymer having a narrower crystallinity distribution can be obtained than when using a Ziegler catalyst. However, in a system in which sequential polymerization is performed as in the present invention, the crystallinity distribution is obtained. It is not necessary and sufficient to use a metallocene catalyst in order to narrow the range. More specifically, the use of a metallocene catalyst alone does not satisfy the necessary and sufficient conditions for narrowing the crystallinity distribution of component (A2).

In order to adjust the final propylene-ethylene random block copolymer to those having desirable physical properties, the component (A1) and the component (A2) need to have different specific polymer compositions. That is, in the first step and the second step, it is necessary to keep the polymerization conditions corresponding to the respective polymer compositions, particularly the monomer gas composition, at different specific values. Therefore, when the crystallinity distribution of the component (A2) is wide in the adopted process, the transfer step is adjusted so that the specific monomer gas mixture corresponding to the first step is not brought into the second step from the first step. It is necessary to devise such as.
Specifically, the crystallinity distribution of the component (A2) can be narrowed by increasing the purge amount in the transfer step, or by diluting or substituting with an inert gas such as nitrogen. That is, H (A3) can be controlled to be small by adjusting the transfer process.

(7) About W (Mw ≦ 5,000) A method of controlling the component amount W (Mw ≦ 5,000) having a weight average molecular weight of 5,000 or less can be controlled by using the same method as described above. Generally, by using a metallocene catalyst, a polymer having a narrower molecular weight distribution than that of a Ziegler catalyst can be obtained. However, in a system that performs sequential polymerization as in the present invention, it is not always sufficient to use a metallocene catalyst to narrow the molecular weight distribution. In particular, in order to prevent the formation of low molecular weight components, the time for transferring from the first step to the second step can be shortened, or the monomer gas mixture corresponding to the first step can be replaced with an inert gas such as nitrogen in the transfer step. By completely replacing it, W (Mw ≦ 5,000) can be controlled to be small independently of the polymerization conditions.

(8) Intrinsic Viscosity For [η] cxs, the block copolymer component of the present invention uses a metallocene catalyst, so that the component (A1) contains almost no CXS component. It can be controlled by changing the molecular weight.
In order to control [η] cxs, the ratio of hydrogen supply to the monomer in the second step may be controlled as usual. In general, metallocene catalysts tend to have a lower molecular weight of the polymer as the polymerization temperature is higher. Therefore, [η] cxs can also be controlled by changing the polymerization temperature. [Η] cxs can also be controlled by combining both the hydrogen supply ratio and the polymerization temperature.

5. Regarding the process oil of component (B) (1) Process oil As the process oil of component (B) used in the present invention, a so-called process oil, which is a softening agent for improving the molding processability of rubber materials, is generally used. And added in order to increase the flexibility of the polypropylene resin composition.
The process oil can be applied to any mineral oil and synthetic oil. Specific examples of the mineral oil include paraffinic oil, naphthenic oil, and aromatic oil. Examples of the synthetic oil include alkylbenzene and polybutene. .
A normal process oil is a mixture of three types of paraffins, naphthenes and aromatics, and those whose paraffin chain carbon number occupies 50% by weight or more of the total carbon number is called paraffinic oil. Those having a ring carbon number of 30 to 45% by weight are called naphthenic oils, and those having more than 30% by weight of aromatic carbons are called aromatic oils to be distinguished.
In these, it is preferable from a heat resistant viewpoint to use paraffinic oil. The weight average molecular weight is 200 to 2,000, preferably 300 to 1,500.

(2) Blending amount The blending ratio of the process oil to the entire composition is 1 to 30 wt%, preferably 2 to 25 wt%, more preferably 3 to 23 wt%, as described above in paragraph 0020.
If the amount is less than 1 wt%, sufficient flexibility cannot be obtained, and if it exceeds 30 wt%, the process oil bleeds out and causes stickiness.

6). Production of Composition The resin composition comprising the random block copolymer and process oil in the present invention can be produced using any conventionally known melt-kneading method.
For example, the random block copolymer and the process oil may be mixed at room temperature, and the resin may be sufficiently impregnated with the oil, followed by melt kneading using a uniaxial or biaxial kneading extruder. Alternatively, it may be produced by providing a feed hole in the middle of the kneading extruder, feeding oil from the feed hole, and simultaneously performing mixing and melt-kneading of the resin and oil.

7). Additional component In the propylene-ethylene block copolymer composition of the present invention, in addition to the essential component, an additional component (optional component) can be blended within a range that does not significantly impair the effects of the present invention.
These additional components include nucleating agents, phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, neutralizers, light stabilizers, and UV absorbers that are conventionally used as polyolefin resin compounding agents. Various additives such as an agent, a lubricant, an antistatic agent, a metal deactivator, a peroxide, a filler, an antibacterial and antifungal agent, and a fluorescent brightening agent can be added.
The amount of these additives is generally 0.0001 to 3 wt%, preferably 0.001 to 1 wt%.

8). Use of composition The use of the composition of the present invention is not particularly limited and can be used for various applications in various technical fields.
In particular, it is useful as a molded product such as a film and a sheet, a fiber material, a container or a vehicle material.

In order to describe the present invention more specifically, examples and comparative examples will be described below. However, in order to clarify the present invention more clearly, examples and the like will be described. This demonstrates the significance and effectiveness of each requirement of the composition in the invention.
The measurement methods of various physical properties of the ethylene-propylene random block copolymer component and the resin composition obtained in the following production examples are as follows.

1) Melt flow rate (MFR)
According to JIS K7210 A method condition M, it measured on condition of the following.
Test temperature: 230 ° C
Nominal weight: 2.16kg
Die shape: Diameter 2.095mm Length 8.00mm

2) TREF
[Create elution curve]
According to the method described above in paragraph 0032.
[apparatus]
(TREF part)
TREF column: 4.3 mmφ × 150 mm stainless steel column Column packing material: 100 μm Surface inactive glass beads Heating method: Aluminum heat block Cooling method: Peltier device (Peltier device is cooled by water)
Temperature distribution: ± 0.5 ° C
Temperature controller: Chino Corporation Digital Program Controller KP1000 (Valve Oven)
Heating method: Air bath oven Measurement temperature: 140 ° C
Temperature distribution: ± 1 ° C
Valve: 6-way valve 4-way valve (Sample injection part)
Injection method: Loop injection method Injection volume: Loop size 0.1ml
Inlet heating method: Aluminum heat block measurement temperature: 140 ° C
(Detection unit)
Detector: Fixed wavelength infrared detector FOXBORO MIRAN 1A
Detection wavelength: 3.42 μm
High-temperature flow cell: LC-IR micro flow cell Optical path length 1.5mm Window shape 2
φ × 4mm long round Synthetic sapphire window measurement temperature: 140 ℃
(Pump part)
Liquid feed pump: SSC-3461 pump manufactured by Senshu Kagaku Co. [Measurement conditions]
Solvent: o-dichlorobenzene (containing 0.5 mg / mL BHT)
Sample concentration: 5 mg / mL
Sample injection volume: 0.1 mL
Solvent flow rate: 1 mL / min

3) Measurement of solid viscoelasticity A sample cut into a strip of 10 mm width × 18 mm length × 2 mm thickness from a 2 mm thick sheet injection molded under the following conditions was used. The apparatus used was ARES manufactured by Rheometric Scientific. The frequency is 1 Hz. The measurement temperature was raised stepwise from −60 ° C., and the measurement was performed until the sample melted and became impossible to measure. The strain was performed in the range of 0.1 to 0.5%.
[Create specimen]
Standard number: JIS-7152 (ISO294-1)
Molding machine: TU-15 injection molding machine manufactured by Toyo Machine Metal Co., Ltd. Molding machine set temperature: 80, 80, 160, 200, 200, 200 ° C. from below the hopper
Mold temperature: 40 ℃
Injection speed: 200 mm / s (speed in the mold cavity)
Injection pressure: 800 kgf / cm ²
Holding pressure: 800 kgf / cm ²
Holding time: 40 seconds
Mold shape: Flat plate (2mm thickness, 30mm width, 90mm length)

4) DSC
Using a Seiko DSC, take 5.0 mg of sample, hold at 200 ° C. for 5 minutes, crystallize to 40 ° C. at a rate of temperature decrease of 10 ° C./minute, and further melt at a temperature increase rate of 10 ° C./minute. The melting peak temperature was Tm (unit: ° C.). DHm was determined from the area of the endothermic curve at the time of temperature increase.

5) GPC
The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured by gel permeation chromatography (GPC).
Conversion from the retention volume to the molecular weight is performed using a calibration curve prepared in advance with standard polystyrene.
The measurement method is the method detailed in paragraph 0048.

6) Room temperature xylene soluble component (CXS)
A 2 g sample is dissolved in 300 ml of p-xylene (containing 0.5 mg / ml BHT) at 130 ° C. to make a solution, and then left at 23 ° C. for 12 hours. Thereafter, the precipitated polymer is filtered off, p-xylene is evaporated from the filtrate, and further dried under reduced pressure at 100 ° C. for 12 hours, and CXS is collected and weighed.

7) Intrinsic viscosity (Intrinsic viscosity is synonymous)
Using an Ubbelohde viscometer, decalin was used as a solvent and the temperature was measured at 135 ° C.

8) Calculation of ethylene content According to the method detailed in paragraphs 0033-0039.

[Production Example 1]
1) Preparation of prepolymerization catalyst (chemical treatment of silicate) Slowly add 3.75 liters of distilled water, followed by 2.5 kg of concentrated sulfuric acid (96%) to a 10-liter glass separable flask equipped with a stirring blade. Added. At 50 ° C., 1 kg of montmorillonite (Menzawa Chemical Co., Ltd. Benclay SL; average particle size = 25 μm, particle size distribution = 10-60 μm) was dispersed, heated to 90 ° C., and maintained at that temperature for 6.5 hours. After cooling to 50 ° C., the slurry was filtered under reduced pressure to recover the cake. 7 liters of distilled water was added to this cake to reslurry it, and then filtered. This washing operation was performed until the pH of the washing solution (filtrate) exceeded 3.5. The collected cake was dried at 110 ° C. overnight under a nitrogen atmosphere. The weight after drying was 707 g.
(Drying of silicate) The silicate previously chemically treated was dried by a kiln dryer. Specifications and drying conditions are as follows.
Rotating cylinder: Cylindrical inner diameter 50 mm Heating zone 550 mm (electric furnace) Number of rotations with lifting blade: 2 rpm Tilt angle: 20/520 Silicate feed rate: 2.5 g / min Gas flow rate: Nitrogen 96 liters / hour Countercurrent drying Temperature: 200 ° C (powder temperature)
(Preparation of catalyst) 20 g of dry silicate was introduced into a glass reactor equipped with a stirring blade having an internal volume of 1 liter. did. After 1 hour, the mixture was washed with mixed heptane to prepare a silicate slurry to 200 ml. Next, 0.96 ml of a heptane solution of triisobutylaluminum (0.71 M / L) was added to the silicate slurry prepared above and reacted at 25 ° C. for 1 hour. In parallel, 218 mg (0.3 mM) of (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azulenyl}] zirconium and 87 ml of mixed heptanes were added to A mixture obtained by adding 3.31 ml of a heptane solution of isobutylaluminum (0.71 M) and reacting at room temperature for 1 hour was added to the silicate slurry, and after stirring for 1 hour, mixed heptane was added to prepare 500 ml.
(Preliminary polymerization / washing) Subsequently, the previously prepared silicate / metallocene complex slurry was introduced into a stirring autoclave having an internal volume of 1.0 liter sufficiently substituted with nitrogen. When the temperature was stabilized at 40 ° C., propylene was supplied at a rate of 10 g / hour to maintain the temperature. After 4 hours, the supply of propylene was stopped and maintained for another 2 hours.
After completion of the prepolymerization, the remaining monomer was purged, stirring was stopped, and the mixture was allowed to stand for about 10 minutes, and then the supernatant was decanted. Subsequently, 0.95 ml of a heptane solution of triisobutylaluminum (0.71 M / L) and 560 ml of mixed heptane were further added, stirred for 30 minutes at 40 ° C., allowed to stand for 10 minutes, and then 560 ml of the supernatant was removed. This operation was further repeated 3 times. When the component analysis of the final supernatant was performed, the concentration of the organoaluminum component was 1.23 mmol / liter and the Zr concentration was 8.6 × 10 ⁻⁶ g / L. Was 0.016%. Subsequently, 17.0 ml of a heptane solution of triisobutylaluminum (0.71 M / L) was added, followed by drying at 45 ° C. under reduced pressure. A prepolymerized catalyst containing 2.0 g of polypropylene per 1 g of catalyst was obtained.
Using this prepolymerized catalyst, a propylene-ethylene random block copolymer was produced according to the following procedure.

2) First Step After sufficiently replacing an autoclave with an internal volume of 3 L having a stirring and temperature control device with propylene, 2.76 ml (2.02 mmol) of a triisobutylaluminum / n-heptane solution was added, 38 g of ethylene, 80 ml of hydrogen, Subsequently, 750 g of liquid propylene was introduced, and the temperature was raised to 45 ° C. to maintain the temperature. The above prepolymerized catalyst was slurried with n-heptane, and 35 mg of the catalyst (excluding the weight of the prepolymerized polymer) was injected to initiate polymerization. Polymerization was continued for 75 minutes while maintaining the temperature in the tank at 45 ° C. Thereafter, the residual monomer was purged to normal pressure and further completely replaced with purified nitrogen. When a part of the produced polymer was sampled and analyzed, the ethylene content was 3.7 wt% and the MFR was 16.3 g / 10 min.

3) Second step Separately, a mixed gas used in the second step was prepared using an autoclave having an internal volume of 20 L having a stirring and temperature control device. The preparation temperature was 80 ° C., and the mixed gas composition was ethylene 32.95 vol%, propylene 66.90 vol%, and hydrogen 1500 vol ppm. After a part of the polymer was sampled in the first step, this mixed gas was supplied to a 3 L autoclave to start the polymerization in the second step. The polymerization was continued for 29 minutes at a polymerization temperature of 80 ° C. and a pressure of 2.5 MPa. Thereafter, 10 ml of ethanol was introduced to terminate the polymerization. The recovered polymer was sufficiently dried in an oven. The yield was 331 g, the activity was 9.5 kg / g-catalyst, the ethylene content was 8.7 wt%, and the MFR was 16.6 g / 10 min.

[Production Example-2]
1) First Step In the first step, propylene-ethylene random copolymerization was carried out using a liquid phase polymerization tank equipped with a stirrer having an internal volume of 0.4 m ³ . Liquefied propylene, liquefied ethylene, and triisobutylaluminum were continuously supplied at 90 kg / hr, 3.0 kg / hr, and 21.2 g / hr, respectively. Hydrogen was continuously supplied so that the concentration in the gas phase was 600 volppm.
Further, the prepolymerized catalyst used in Production Example-1 was supplied as a catalyst (excluding the weight of the prepolymerized polymer) so as to be 7.1 g / hr. The polymerization tank was cooled so that the polymerization temperature was 65 ° C.
When the propylene-ethylene random copolymer obtained in the first step was analyzed, BD (bulk density) was 0.47 g / cc, MFR was 16.3 g / 10 min, and ethylene content was 2.2 wt%. .

2) Second Step In the second step, propylene-ethylene random copolymerization was carried out using a stirred gas phase polymerization tank having an internal volume of 0.5 m ³ . The slurry containing polymer particles was continuously withdrawn from the liquid phase polymerization tank in the first step, flushed with liquefied propylene, and then pressurized with nitrogen and continuously supplied to the gas phase polymerization tank.
The polymerization tank was controlled so that the temperature was 80 ° C. and the total partial pressure of propylene, ethylene, and hydrogen was 1.5 MPa. At that time, the concentration of propylene, ethylene, and hydrogen in the total partial pressure of propylene, ethylene, and hydrogen was controlled to 70.93 vol%, 28.98 vol%, and 900 volppm, respectively.
Furthermore, ethanol was supplied to the gas phase polymerization tank as an activity inhibitor. The supply amount of ethanol was set to 0.5 mol / mol with respect to aluminum in TIBA supplied along with the polymer particles supplied to the gas phase polymerization tank.
When the propylene-ethylene random block copolymer thus obtained was analyzed, the activity was 16.3 kg / g-catalyst, the BD was 0.40 g / cc, the MFR was 16.6 g / 10 min, and the ethylene content was 7. It was 2 Wt%.

[Production Example-3]
Propylene-ethylene random copolymer was produced using the prepolymerization catalyst used in Production Example-1.
The autoclave with an internal volume of 3 L having a stirring and temperature control device was sufficiently replaced with propylene, and then 2.76 ml (2.02 mmol) of a triisobutylaluminum / n-heptane solution was added, followed by 38 g of ethylene, 80 ml of hydrogen, and then 750 g of liquid propylene. The temperature was raised to 45 ° C. and maintained at that temperature. The above prepolymerized catalyst was slurried with n-heptane, and 45 mg of the catalyst (excluding the weight of the prepolymerized polymer) was injected to initiate polymerization. Polymerization was continued for 75 minutes while maintaining the temperature in the tank at 45 ° C. Thereafter, 10 ml of ethanol was introduced to terminate the polymerization, the remaining monomer was purged to normal pressure, and further completely replaced with purified nitrogen. The recovered polymer was sufficiently dried in an oven. The yield was 209 g, the activity was 4.6 kg / g-catalyst, the ethylene content was 3.7 wt%, and the MFR was 16.3 g / 10 min.

[Production Example-4]
Using the same prepolymerization catalyst as in Production Example-1, a propylene-ethylene random block copolymer was produced under the following conditions.
1) First Step After the autoclave with an internal volume of 3 L having a stirring and temperature control device was sufficiently substituted with propylene, 2.76 ml (2.02 mmol) of triisobutylaluminum / n-heptane solution was added, 38 g of ethylene, 80 ml of hydrogen, Subsequently, 750 g of liquid propylene was introduced, and the temperature was raised to 45 ° C. to maintain the temperature. The above prepolymerized catalyst was slurried with n-heptane, and 45 mg of the catalyst (excluding the weight of the prepolymerized polymer) was injected to initiate polymerization. Polymerization was continued for 75 minutes while maintaining the temperature in the tank at 45 ° C. Thereafter, the residual monomer was purged to normal pressure and further completely replaced with purified nitrogen. When a part of the produced polymer was sampled and analyzed, the ethylene content was 3.7 wt% and the MFR was 16.3 g / 10 min.

2) Second Step Separately, a mixed gas used in the second step was prepared using an autoclave having an internal volume of 20 L having a stirring and temperature control device. The preparation temperature was 80 ° C., and the mixed gas composition was ethylene 32.95 vol%, propylene 66.90 vol%, and hydrogen 1500 vol ppm. After a part of the polymer was sampled in the first step, this mixed gas was supplied to a 3 L autoclave to start the polymerization in the second step. The polymerization was continued for 5 minutes at a polymerization temperature of 80 ° C. and a pressure of 2.5 MPa. Thereafter, 10 ml of ethanol was introduced to terminate the polymerization. The recovered polymer was sufficiently dried in an oven. The yield was 247 g, the activity was 5.5 kg / g-catalyst, the ethylene content was 5.2 wt%, and the MFR was 16.6 g / 10 min.

[Production Example-5]
Using the same prepolymerization catalyst as in Production Example-1, a propylene-ethylene random block copolymer was produced under the following conditions.
1) First Step After the autoclave with an internal volume of 3 L having a stirring and temperature control device was sufficiently substituted with propylene, 2.76 ml (2.02 mmol) of triisobutylaluminum / n-heptane solution was added, 38 g of ethylene, 80 ml of hydrogen, Subsequently, 750 g of liquid propylene was introduced, and the temperature was raised to 45 ° C. to maintain the temperature. The above prepolymerized catalyst was slurried with n-heptane, and 35 mg of the catalyst (excluding the weight of the prepolymerized polymer) was injected to initiate polymerization. Polymerization was continued for 75 minutes while maintaining the temperature in the tank at 45 ° C. Thereafter, the residual monomer was purged to normal pressure and further completely replaced with purified nitrogen. When a part of the produced polymer was sampled and analyzed, the ethylene content was 3.7 wt% and the MFR was 16.3 g / 10 min.

2) Second Step Separately, a mixed gas used in the second step was prepared using an autoclave having an internal volume of 20 L having a stirring and temperature control device. The preparation temperature was 80 ° C., and the mixed gas composition was ethylene 46.93 vol%, propylene 52.92 vol%, and hydrogen 1500 vol ppm. After a part of the polymer was sampled in the first step, this mixed gas was supplied to a 3 L autoclave to start the polymerization in the second step. The polymerization was continued at a polymerization temperature of 80 ° C. and a pressure of 2.5 MPa for 22 minutes. Thereafter, 10 ml of ethanol was introduced to terminate the polymerization. The recovered polymer was sufficiently dried in an oven. The yield was 331 g, the activity was 9.5 kg / g-catalyst, the ethylene content was 11.7 wt%, and the MFR was 16.6 g / 10 min.

The production examples shown above were repeated several times as necessary to obtain a sufficient amount of polymer and used for the following evaluation.
[Example 1]
The following antioxidant and neutralizing agent were added to the block copolymer powder obtained in Production Example 1 and mixed thoroughly.
[Additive formulation]
Antioxidant: Tetrakis {methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate} methane 500 ppm Tris (2,4-di-t-butylphenyl) phosphite 500 ppm
Neutralizer: Calcium stearate 500ppm
Table 3 shows the results of a characteristic evaluation (TREF NMR DMA GPC CXS intrinsic viscosity bending test) using a block copolymer alone for a part of this granulated and molded under the following conditions.

[Production of composition]
Process oil PW-90 manufactured by Idemitsu Kosan Co., Ltd. (paraffinic oil average molecular weight 539, kinematic viscosity of 95.5 cst at 40 ° C.) as a process oil was added to the block copolymer powder blended with additives. After blending so that the polymer was 90 wt% and the process oil was 10 wt%, the mixture was sufficiently stirred and impregnated, and then melt-kneaded under the following conditions to produce pellets.

[Granulation]
Extruder: KZW-15-45MG twin screw extruder manufactured by Technobel Co., Ltd .: Diameter 15 mm L / D = 45
Extruder set temperature: (from below the hopper) 40, 80, 160, 200, 220, 220 (die temperature)
Screw rotation speed: 400rpm
Discharge amount: Adjusted to 1.5 kg / h with a screw feeder Die: 3 mm diameter Strand die Number of holes 2

[Molding]
The obtained raw material pellet was injection-molded under the following conditions to obtain a flat test piece for evaluating physical properties.
Standard number: JIS K-7152 (ISO294-1) Reference molding machine: TU-15 injection molding machine molding machine manufactured by Toyo Machine Metal Co., Ltd.
Mold temperature: 40 ℃
Injection speed: 200 mm / s (speed in the mold cavity)
Injection pressure: 800 kgf / cm ²
Holding pressure: 800 kgf / cm ²
Holding time: 40 seconds
Mold shape: Flat plate (2mm thickness, 30mm width, 90mm length)

[Bending characteristics test]
The bending elastic modulus of the obtained resin composition was evaluated under the following conditions.
Standard number: JIS K-7171 (ISO178) compliant tester: Precision universal tester Autograph AG-20kNG (manufactured by Shimadzu Corporation)
Specimen sampling direction: Flow direction Specimen shape: Thickness 2.0 mm Width 25.0 mm Length 40.0 mm
Test piece preparation method: Injection molded flat plate is punched to the above dimensions (see paragraph 0100 for molding)
Condition adjustment: Room temperature 23 ° C., humidity controlled at 50% humidity for 24 h or longer Test room: Room temperature 23 ° C. Number of temperature controlled specimens adjusted at 50% humidity: n = 5
Distance between fulcrums: 32.0mm
Test speed: 1.0 mm / min

[Bleed Out]
The bleed out of the oil was evaluated in the injection molded piece of the resin composition. The evaluation results are as follows.
○ ・ ・ ・ Oil bleed-out is not observed and the molded piece is not sticky △ ・ ・ ・ Slight bleed-out is observed × ・ ・ ・ A large amount of oil bleed-out is observed, and the molded piece is sticky

[Measurement of transparency (Haze)]
The transparency of the block copolymer was evaluated under the following conditions.
Standard number: JIS K-7136 (ISO 14782) JIS K-7361-1 compliant measuring machine: Haze meter NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.)
Test piece thickness: 2 mm
Test piece preparation method: injection molded flat plate (see the molding section for molding)
Condition adjustment: Number of test pieces left for 24 hours in a temperature-controlled room adjusted to 50% humidity at room temperature 23 ° C after molding: 3
Evaluation item: Haze

[Heat-resistant]
The Vicat softening point of the block copolymer was evaluated under the following conditions.
Standard number: JIS7206 reference (Complies with 50 methods except for load 250g)
Measuring machine: Fully automatic HDT measuring machine (manufactured by Toyo Seiki)
Specimen shape: 2mm thickness 25mm x 25mm Two flat plate stacking method Specimen creation method: Injection molded flat plate is punched into the above shape (see molding section for molding)
Condition adjustment: 24 hours or more in a temperature-controlled room at 23 ° C and 50% humidity (no annealing)
Test weight: 250g
Temperature increase rate: 50 ° C./hour Number of test pieces: 3
The above evaluation results are shown in Table 4.

[Examples 2 to 6] and [Comparative Examples 1 to 6]
The same procedure as in Example 1 was conducted except that the types and blending amounts of the block copolymer and process oil were as shown in Table 2. The results are shown in Table 4.

[Consideration by contrast between Example and Comparative Example]
Considering each of the above examples and each comparative example in contrast, in each example of the novel polypropylene resin composition that satisfies each rule in the configuration of the present invention, it is represented by the flexural modulus. It is understood that it is obvious that the flexibility is excellent, the transparency expressed by Haze% and the heat resistance expressed by the Vicat softening point are also good, and the bleed-out is suppressed.
In Comparative Examples 1 and 2, although the component (A) satisfies the prescribed requirements, the blending amount of the component (B) is too large, resulting in deterioration of bleed out. In addition, since the component (A) uses the thing of this invention, a softness | flexibility is remarkably excellent based on this.
In Comparative Examples 3 to 4, the component (A) does not have the component (A2), and the tan δ curve does not have a peak at 0 ° C. or lower, so the flexibility is poor.
In Comparative Example 5, since the component (A2) in the component (A) is too small, the flexibility is inferior. Similarly, in Comparative Example 6, the component (A2) in the component (A) is too small, so that the flexibility is low. Although it is inferior, since the component (B) is increased, the flexibility is not lowered as in Comparative Example 5. However, transparency is slightly inferior.
In Comparative Example 7, as can be seen from the fact that the random block copolymer component has two peaks in tan δ, the phase separation causes poor transparency, and even if a process oil is blended, the flexibility is excellent. The transparency of things is inferior.
From the above results, it is clarified that each definition of the constituent requirements in the composition of the present invention is significant and confirmed by experimental data.

It is a graph which shows the elution amount curve and elution amount integration in manufacture example-1. It is a graph which shows the solid viscoelasticity measurement in manufacture example-1. It is a graph which shows the solid viscoelasticity measurement in manufacture example-5.

Claims (6)

As a component (A), a propylene-ethylene random block copolymer obtained by sequential polymerization using a metallocene catalyst, which is a crystalline propylene-ethylene random copolymer having an ethylene content of 1 to 7 wt% in the first step. The polymer component is 30 to 70 wt%, and the second step is a sequential polymerization of 70 to 30 wt% of a low crystalline or amorphous propylene-ethylene random copolymer component containing 6 to 15 wt% more ethylene than the first step. 99 to 70 wt% of a propylene-ethylene random block copolymer satisfying the following condition (i) and 1 to 30 wt% of a process oil component as a component (B), and a flexural modulus is 250 MPa or less A polypropylene-based resin composition characterized by being.
(I) In the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA), the tan δ curve has a single peak at 0 ° C. or lower. The polypropylene resin composition according to claim 1, wherein the component (B) is a paraffinic oil having a weight average molecular weight of 200 to 2,000. The polypropylene resin composition according to claim 1 or 2, wherein the component (A) alone has a flexural modulus of 450 MPa or less. The polypropylene resin composition according to any one of claims 1 to 3, wherein the component (A) satisfies the following conditions (ii) and (iii).
(Ii) TREF elution curve obtained as a plot of elution amount (dWt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. , The peak T (A1) observed on the high temperature side is in the range of 65 to 95 ° C., the peak T (A2) observed on the low temperature side is below 45 ° C., or the peak T (A2) is observed The temperature T (A4) at which 99 wt% elutes is 98 ° C. or less, and the temperature difference ΔT (T (A4) −T (A1)) from the peak T (A1) to T (A4) is 5 ° C. or less. There is.
(Iii) Both peaks of peaks T (A1) and T (A2) in the TREF elution curve (when component (A2) does not show a peak, T (A2) is −15 ° C., which is the lower limit of the measurement temperature). The ratio H (A3) / H (A1) of the elution amount H (A3) at the temperature T (A3) at the midpoint between and the elution amount H (A1) at T (A1) is 0.1 or less. The component (A) satisfies the following conditions (iv) and (v): The polypropylene resin composition according to any one of claims 1 to 4.
(Iv) The weight average molecular weight Mw obtained by gel permeation chromatography (GPC) measurement is in the range of 100,000 to 400,000, and the component weight W having a weight average molecular weight of 5,000 or less is 0.8 wt. % Or less.
(V) The intrinsic viscosity [η] cxs measured in 135 ° C. decalin of the 23 ° C. xylene soluble component is in the range of 1 to 2 (dl / g). The film and sheet | seat or molded article formed by shape | molding the polypropylene resin composition as described in any one of Claims 1-5.

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