JP2005132992A - Propylene-ethylene random block copolymer and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a propylene-ethylene random block copolymer in which transparency and flexibility in a polyolefin-based elastomer are improved and the above properties and heat resistance are balanced and stickiness and bleedout are suppressed. <P>SOLUTION: The propylene-ethylene random block copolymer is obtained by carrying out successive polymerization by using a metallocene catalyst. The propylene-ethylene random block copolymer is obtained by successive polymerization of 30-70 wt.% crystalline copolymer component (A) having 105-145°C melting peak temperature in the first step and 70-30 wt.% low (non-)crystalline copolymer component (B) containing an ethylene content larger by 6-15 wt.% than the ethylene content contained in the component (A) in a second step and satisfies the following conditions: (i) the block copolymer has a single peak at ≤0°C in temperature-loss tangent curve; (ii) storage elastic modulus G' [MPa] at 23°C obtained by measurement of solid viscoelasticity is ≤200; (iii) the temperature Tα at which G' becomes 2 MPA is 100 to 140°C and (iv) the difference between the melting peak temperature Tm and Tα is ≤20°C. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a propylene-ethylene random block copolymer and a method for producing the same, and more specifically, excellent transparency, a high balance between flexibility and heat resistance, suppression of stickiness and bleedout of products, and particularly moldability. The present invention relates to a novel propylene-ethylene random block copolymer having a specific crystallinity distribution with improved moldability at low temperature and a method for producing the same.

  Olefin-based thermoplastic elastomers or plastomers are blends of polymer components such as random copolymers typified by ethylene-α-olefin copolymer elastomers. Since it is highly adaptable to problems and is lightweight and excellent in moldability and economic efficiency, it is widely used in a wide range of fields such as films and sheets, fibers and nonwoven fabrics, various containers and molded products, and modifiers.

Among such thermoplastic elastomers, what is called a block type reactor TPO, which produces crystalline polypropylene in the first step and a propylene-ethylene copolymer elastomer in the second step, is compared to a random copolymer type elastomer. It has the characteristics of excellent heat resistance, strength and productivity, and for elastomers manufactured by mechanical mixing, the product quality is stable and the manufacturing process is shortened, and the manufacturing cost is reduced. In recent years, it has been widely used because it has excellent characteristics such as excellent heat resistance and strength, good dispersibility of the elastomer, and a wide variation of the elastomer composition.
However, these reactors TPO are excellent in transparency, but often the difference in ethylene content between the crystalline polypropylene produced in the first step and the propylene-ethylene copolymer elastomer produced in the second step. Phase-separated due to, for example, the transparency is remarkably deteriorated, and many of them have low heat resistance and poor flexibility, and in particular, when the flexibility is improved, the heat resistance is extremely deteriorated. .
Therefore, if a polyolefin elastomer or plastomer having excellent transparency and flexibility and good heat resistance is realized, it is recognized as being extremely significant in the industry, and various improvements have been proposed so far.

For example, in order to improve flexibility and solve the deterioration of transparency, a polypropylene or propylene-ethylene copolymer having a low ethylene content in the first step and an ethylene content higher than that in the first step in the second step A technique is disclosed in which relatively few propylene-ethylene copolymer elastomers are continuously polymerized using a Ziegler-Natta catalyst (see Patent Citations 1 and 2). However, since Ziegler-Natta catalysts have multiple types of active sites, the resulting propylene-ethylene copolymer has a wide crystallinity and molecular weight distribution, and produces many low crystals and low molecular weight components. And bleed-out (exudation of low molecular weight components and additives) is strongly observed, and there is a drawback that problems such as blocking and poor appearance tend to occur.
In order to improve this method, a method of increasing the intrinsic viscosity of the elastomer, that is, the molecular weight more than a certain degree to suppress the formation of low molecular weight components has been disclosed (see Patent Document 3). Since the formation of sexual components is difficult to suppress, the transparency is not sufficient, the improvement of stickiness and bleed out is still insufficient, and the high molecular weight of the elastomer causes the appearance defects called “butsu” and “fish eye”. Since it tends to occur and extrudability deteriorates, it has many problems such as having to use an organic peroxide in the granulation process.

  In contrast to the reactor TPO produced using such Ziegler-Natta catalysts, a reactor TPO was also developed from a new point of view using a metallocene catalyst, and polypropylene was developed in the first step and propylene in the second step. And propylene copolymer showing a specific elution pattern in temperature rising elution fractionation by TREF by polymerizing ethylene and / or C4 to C18 α-olefin, and molecular weight distribution and Since the crystallinity distribution is narrow, there is no stickiness (see Patent Documents 4 and 5).

Specifically, in Patent Document 4, a component composed of a polypropylene component and a copolymer component of propylene and ethylene, and 50% of the components eluted up to 90 ° C. in the temperature rising elution fractionation method using an o-dichlorobenzene solvent. By the propylene-based resin composition satisfying the requirements such that the component eluting at a temperature of ˜99 wt% and 90 ° C. or higher is 50 to 1 wt% of the total, and the amount of the component eluting by 0 ° C. is 10 wt% or less. It is disclosed that this problem is solved.
However, although the propylene-based resin composition obtained by this method is excellent in transparency, in a region where there are relatively many components that elute at a temperature of 90 ° C. or higher, heat resistance is high but flexibility cannot be said to be sufficient. When the components eluted at a temperature of 90 ° C. or more are reduced, the flexibility is improved, but the heat resistance is remarkably deteriorated, and the blocking increases due to the increase in stickiness. Furthermore, the propylene-based resin composition obtained by such a method has a high crystal melting temperature and is not particularly suitable for molding at a low temperature such as calendar molding.

Moreover, in patent document 5, the method of increasing the ethylene content copolymerized at a 2nd process and increasing the component eluted at 0 degrees C or less is disclosed.
In this method, a propylene-based resin composition having very excellent flexibility can be obtained, but even if the haze value is not high, transparency is deteriorated due to the generation of a phase separation structure of the composition components, and the flexibility is flexible. The balance between heat resistance and heat resistance is not sufficient, and there are problems such as deterioration in appearance due to the occurrence of flow marks, reduction in total light transmittance, and inevitable stickiness and heat resistance. .

  However, the reactor TPO from the new viewpoint of using a metallocene-based catalyst is recognized as having the possibility of improving both flexibility and transparency and balancing heat resistance, and is a characteristic of the catalyst. It can be said that this technology should be attracted attention and developed in the future due to its high catalytic activity, the formation of sharp molecular weight distribution, and unique stereoregularity.

Japanese Patent Laid-Open No. 63-159212 (Claims, lower right column on page 2) JP 63-168414 (Claims, lower right column on page 2) Japanese Patent No. 3358441 (Claim 1 of Claims) JP 2000-239462 A (summary) JP 2001-64335 A (summary)

The present invention is based on the state of the prior art in the field of polyolefin-based elastomer or plastomer materials as described in detail in paragraphs 0002 to 0008, and the technical flow of the development of reactor TPO from the new viewpoint of using a metallocene-based catalyst. In line with the above, we are seeking to improve the quality of materials such as polyolefin-based elastomers, and to achieve the balance between transparency and flexibility of polyolefin-based elastomer materials and heat resistance, which are particularly important and important for improvement. The main object of the invention is to develop a very useful polymer material.
The present invention is a polyolefin-based elastomer material with improved transparency, flexibility and heat resistance. In addition, the present invention suppresses stickiness and bleed-out, does not cause appearance defects due to so-called blisters, and is formable. In addition, the present invention aims to commercialize an excellent propylene-ethylene random block copolymer that is advantageous as a molding material.

  In order to solve the above-described problems of the invention, the present inventors can say that the demand and importance of polyolefin elastomer materials in the polymer material field are very high. In the random block copolymer, while considering the prior art, considering the overall properties of the reactor TPO from the new viewpoint of using a metallocene catalyst, the raw materials and polymerization catalyst Alternatively, the investigation and experimental search are repeated over the polymerization conditions, performance identification and copolymer composition, and in those processes, in the production of the reactor TPO using the metallocene catalyst, the sequential (multistage) polymerization method is selected, The highly crystalline component of the block copolymer has a narrow crystallinity distribution and decreases crystallinity. Adopt specific propylene-ethylene random block copolymer, combine specific amount of specific low crystalline or non-crystalline propylene-ethylene random block copolymer, and further improve flexibility and heat resistance Can realize the balance between transparency and flexibility of polyolefin elastomer material and heat resistance by paying attention to solid viscoelasticity measurement related to elasticity and thermal properties of olefin polymer. As a result, the present invention was created.

Specifically, a specific block copolymer with a low crystallinity distribution and a reduced crystallinity In a highly crystalline component, the amount ratio, melting peak temperature or ethylene content for the low crystalline component is specified, and the block copolymer Specify the amount ratio and ethylene content of low-crystalline or non-crystalline components to high-crystalline components, and further, the temperature-loss tangent (tan δ) of solid viscoelasticity measurement related to the elasticity and thermal properties of olefin polymers The Tg peak characteristics in the curve, the storage elastic modulus in the measurement of solid viscoelasticity, or experimentally defining the characteristics in the melting peak curve obtained by the differential scanning calorimeter (DSC) are very transparent and flexible. Excellent, heat-resistant balance, new product with no stickiness of product, bleed-out is suppressed, and moldability is excellent Propylene - could be found to be an important requirement for obtaining ethylene block copolymer.
In addition, in the novel propylene-ethylene block copolymer of the present invention, the result that the moldability at low temperature is improved by lowering the melting point of the highly crystalline component is obtained. The novel propylene-ethylene block copolymer of the present invention has a supplementary effect on the slight decrease in heat resistance due to the lowering of the melting point, and is accompanied by this secondary effect. It can be said that it is important as a very useful polymer material.

Specifically, in such specification or regulation, the melting peak temperature obtained by the differential scanning calorimeter (DSC) is controlled by the range of the ethylene content of the high crystalline component, and the The amount ratio of the crystalline or non-crystalline component is controlled by the production amount in the first step and the second step, the ethylene content of both components is controlled by the amount of ethylene supplied to propylene in the first step and the second step, and the temperature -The peak characteristic of Tg in the loss tangent (tan δ) curve is controlled by the difference in ethylene content of both components, and the characteristic in the melting peak curve obtained by storage elastic modulus in solid viscoelasticity measurement or differential scanning calorimeter (DSC) is Further, the Mw of the block polymer is controlled by the viscosity [η] of the highly crystalline component. The amount of the low molecular weight component of the block polymer is controlled by the transfer time and monomer gas management in the transfer step from the first step to the second step, and the intrinsic viscosity [η] cxs is the hydrogen relative to the monomer in the second step. It has become possible to produce the novel propylene-ethylene block copolymer of the present invention by knowing that it is controlled by the supply amount ratio of the new propylene-ethylene block copolymer. It can be said that such a new method for obtaining is positioned at the forefront of the technical flow of the development of the reactor TPO from a new viewpoint of utilizing a metallocene catalyst in the future.
In other words, these requirements have been experimentally confirmed as a result of experimental investigation, reflected in the results of examples described later, and the embodiments of the invention, which will be described later, as well as examples and comparative examples. As is clear from the comparison of each data of the above, as a result of the accumulation of various deep experimental studies, it was possible to make a significant selection as the best invention component.

  The technology for developing the reactor TPO from a new point of view using a metallocene catalyst can be found in the prior patent documents 4 and 5 as the prior art. These prior arts are described above in paragraphs 0005 to 0007. As described above, for the polypropylene component and the copolymer component of propylene and ethylene, the amount of each component of the medium-low temperature elution component and the high-temperature elution component in the temperature-temperature elution fractionation method and the ethylene unit content and the high-temperature elution of the medium-low temperature elution component The invention is intended to cover ordinary propylene-ethylene block copolymers simply by defining the propylene unit content in the components, etc., while the present invention uses a metallocene catalyst as a catalyst, Sequential (multistage) polymerization of block copolymer is selected, and the crystalline distribution is narrow and the crystallinity of the highly crystalline component in the copolymer is reduced. A specific propylene-ethylene random copolymer with reduced properties, a specific low crystalline or amorphous propylene-ethylene random copolymer combined in a specific amount, as detailed in paragraphs 0012-0013 Special provisions such as Tg peak characteristics in the temperature-loss tangent (tan δ) curve, storage elastic modulus in solid viscoelasticity measurement or melting peak curve obtained by differential scanning calorimeter (DSC), etc. This invention is an invention for obtaining a propylene-ethylene block copolymer, which is essentially different from these prior arts.

  In the above, the background of the creation of the present invention, the features of the structure of the invention and the differences from the prior art, etc. have been described generally, so that the overall structure of the present invention is clarified here in order to provide an overview of the present invention. In the present invention, the present invention is composed of the following group of invention units, the one described in [1] is a basic invention, and [2] the following invention adds an additional requirement to the basic invention, or The embodiment is to be realized. (The entire invention group is collectively referred to as “the present invention”.)

[1] Crystalline propylene-ethylene random copolymer component (A) having a melting peak temperature Tm (A) by a differential scanning calorimeter (DSC) of 105 to 145 ° C. in the first step using a metallocene catalyst 30% to 70% by weight (abbreviated as component (A)), a low crystalline or amorphous propylene-ethylene random copolymer containing 6 to 15% ethylene more than the ethylene content contained in component (A) in the second step. Propylene-ethylene obtained by polymerizing 70 to 30 wt% of polymer component (B) (abbreviated as component (B)) and satisfying the following conditions (i) to (iv) Random block copolymer.
(I) In the temperature-loss tangent (tan δ) curve, it has a single peak below 0 ° C. (ii) In the temperature-storage elastic modulus (G ′) curve obtained by solid viscoelasticity measurement (DMA), The storage elastic modulus G ′ at 23 ° C. (23) [MPa] is 200 or less (iii) The temperature Tα at which G ′ becomes 2 MPa is in the range of 100 to 140 ° C. (iv) The differential scanning calorimeter (DSC The difference between the melting peak temperatures Tm and Tα (Δ (Tm−Tα)) in the melting curve obtained by (1) is 20 ° C. or lower. [2] The following (v) is satisfied: Propylene-ethylene random block copolymer in 1].
(V) The weight average molecular weight Mw of the block copolymer obtained by gel permeation chromatography (GPC) measurement is in the range of 100,000 to 400,000, and the molecular weight W (M ≦ 5,000) is 0.8 wt% or less of the whole [3] The propylene-ethylene random block copolymer according to [1] or [2], which satisfies the following condition (vi) .
(Vi) 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] [4] The ethylene content in component (A) The propylene-ethylene random block copolymer according to any one of [1] to [3], wherein the content is 1 to 10 wt%.
[5] When component (A) and component (B) are sequentially polymerized using a metallocene catalyst, Tm (A) is controlled by the range of the ethylene content of component (A), and component (A) and component (B ) Is controlled by the production amount in the first step and the second step, the ethylene content of the component (A) and the component (B) is controlled by the amount of ethylene supplied to propylene in the first step and the second step, By making the difference in ethylene content between (A) and component (B) not more than 15% by weight, a single peak of condition (i) is obtained, and G ′ of condition (ii) and Tα of condition (iii) and Each of Δ (Tm−Tα) in the condition (iv) is controlled by the range of the ethylene content of the component (A) and the component (B), and the Mw of the block polymer in the condition (v) is determined by the viscosity [ [eta]], and the component amount W of the block polymer under the condition (v) M ≦ 5,000) is controlled by the transfer time and monomer gas management in the transfer process from the first process to the second process, and the intrinsic viscosity [η] cxs of the condition (vi) is controlled by adjusting the molecular weight in the second process. The manufacturing method of the propylene-ethylene random block copolymer in any one of [1]-[3] characterized by the above-mentioned.
[6] A molded article comprising a film and a sheet and a laminate or a container, which is molded from the propylene-ethylene random block copolymer according to any one of [1] to [4].

As is clear from the above explanation, the propylene-ethylene random block copolymer in the present invention is very excellent in flexibility and transparency, has a good balance of heat resistance, and has no stickiness of the product, and bleed. It is a polyolefin elastomer with controlled out and excellent moldability.
The propylene-ethylene random block copolymer as the polyolefin elastomer of the present invention can be effectively used as a molded product comprising a film and a sheet and a laminate or a container.

Hereinafter, the best mode for carrying out the present invention will be described in detail.
1. Propylene-ethylene block copolymer
1. -(1) Identification by Catalyst and Polymerization Method The novel propylene-ethylene block copolymer of the present invention comprises a crystalline propylene-ethylene random copolymer component (A) and a low crystalline or amorphous propylene- The present invention relates to a block copolymer under a common name obtained by sequential (multistage) polymerization of an ethylene random copolymer component (B) using a metallocene catalyst.
The first feature of the propylene-ethylene block copolymer of the present invention is a polyolefin elastomer copolymer as a reactor TPO obtained by sequential (multistage) polymerization using a metallocene catalyst.
In the Ziegler-Natta catalyst, as described in paragraph 0004, since the Ziegler-Natta catalyst has a plurality of types of active sites, the produced propylene-ethylene copolymer has a wide crystallinity and molecular weight distribution, and has a low crystallinity. By producing a lot of low molecular weight components, product stickiness and bleed-out (exudation of low molecular weight components and additives) are strongly seen, and problems such as blocking and poor appearance are likely to occur. In addition, since the formation of low crystalline components is difficult to be suppressed even when the molecular weight is increased, transparency is not sufficient, improvement in stickiness and bleedout is still insufficient, and the molecular weight of the elastomer is high. It is easy to generate poor appearance called as fisheye and fish eye, and the extrudability deteriorates, so organic peroxide must be used in the granulation process. It has a number of problems such as the stomach.
Therefore, in the present invention, first, a polymerization method using a metallocene catalyst is selected in order to eliminate the above-described drawbacks in the polyolefin elastomer copolymer as a reactor TPO using a Ziegler-Natta catalyst.
Conventionally, a crystalline propylene-ethylene random copolymer component (A) and a low crystalline or amorphous propylene-ethylene random copolymer component (B) are separately produced and mechanically mixed. In this method, since the good block copolymer performance aimed by the present invention cannot be obtained, the production of the block copolymer of the present invention is specified as the sequential polymerization method, particularly the sequential multistage polymerization method.

1. -(2) Crystalline component (A)
A. Melting peak temperature Tm (A) by differential scanning calorimeter (DSC)
In the block copolymer of the present invention, since the crystalline component (A) is a component necessary for maintaining heat resistance, it must have appropriate crystallinity, and the melting temperature becomes an important figure of merit. The melting peak temperature Tm (A) is preferably defined by a differential scanning calorimeter (DSC). If the melting peak temperature Tm (A) becomes too low, the heat resistance deteriorates. Therefore, in view of the heat resistance requirement for the polyolefin elastomer copolymer, Tm (A) is 105 ° C. or higher, preferably 110 ° C. or higher. It is necessary.
On the other hand, as the melting point increases, the crystallinity of the component (A) increases accordingly, and when the Tm (A) is 145 ° C. or higher, the rigidity of the component (A) becomes too high to impart flexibility. Since a very large amount of component (B) is required, Tm (A) needs to be 145 ° C. or lower, preferably 140 ° C. or lower.
Since component (A) needs to be a propylene-ethylene random copolymer, in order to make Tm (A) into the above range, the ethylene content in component (A) is about 1 to 10 wt%. It is preferable to do. Even if Tm (A) is within this range, when ethylene is not included, compatibility with component (B) decreases, transparency deteriorates, and the glass transition temperature does not decrease, so that resistance at low temperatures is reduced. This causes a problem that the impact property deteriorates, which is not preferable.
The melting peak temperature Tm (A) is measured as a melting peak temperature by a differential scanning calorimeter (DSC) by a conventional method with respect to a component (A) sampled in a small amount after the first step. Moreover, when sampling is difficult, you may perform with respect to the component (A) fractionated by the method as described in Paragraphs 0026-0027.

B. Weight ratio of crystalline component (A) The proportion of component (A) in the block copolymer is defined as 30 to 70 wt% in the block copolymer. Therefore, the ratio of a component (B) will be 70-30 wt%.
When the proportion of the component (A) is less than 30 wt%, the heat resistance is insufficient, whereas when it is 70 wt% or more, the flexibility is deteriorated.

C. Ethylene content Since the ethylene content in the crystalline component (A) is deeply related to the flexibility, transparency, heat resistance, etc. of the block copolymer, it is set in consideration of the balance of these properties. Further, the ethylene content in the component (A) is deeply related to Tm (A), Tα described in detail below, and the like, and can be controlled as specified. Further, the ethylene content in the component (A) is related to the Tg peak characteristics in the temperature-loss tangent (tan δ) curve as a definition of the difference from the ethylene content in the component (B).

1. -(3) Low crystalline or amorphous component (B)
The low crystalline or amorphous propylene-ethylene random copolymer component (B) is a component for imparting flexibility to the block copolymer.
A. Ethylene content In terms of improving flexibility, the lower the crystallinity of the component (B), the better. In the case of a propylene-ethylene random copolymer, the crystallinity can be lowered by increasing the ethylene content in the copolymer. Therefore, in the present invention, the ethylene content in component (B) needs to be 6 wt% or more, preferably 8 wt% or more, higher than component (A). On the other hand, if the ethylene content of the component (B) is excessively increased in the block copolymer, the component (A) and the component (B) take a phase-separated structure divided into a matrix and a domain, and the transparency is significantly deteriorated. The ethylene content of component (B) should not be increased too much. This is because polypropylene originally has low compatibility with polyethylene, and even in a propylene-ethylene random copolymer, the compatibility of two components having different ethylene contents decreases as the difference in ethylene content increases.
Therefore, in the present invention, the difference between the ethylene content [E] A (wt%) contained in the crystalline component (A) and the ethylene content [E] B (wt%) contained in the component (B), It is necessary not to increase the difference [E] gap ([E] B- [E] A) of ethylene content, and it is defined as 15 wt% or less, preferably 13 wt% or less.

B. TREF measurement The ratio of component (A) to component (B) and their ethylene content are measured by TREF (temperature-temperature elution fractionation method) as follows.
First, using the difference in crystallinity between the component (A) and the component (B), a temperature T (C) for dividing the components (A) and (B) is determined from the elution curve obtained by TREF measurement, and T The proportion of the component eluted until (C) is regarded as the proportion of component (B), and the proportion of the component eluted at T (C) or higher is regarded as the proportion of component (A).
The technique for evaluating the crystallinity distribution of the propylene-ethylene random copolymer by TREF measurement is well known to those skilled in the art. Glokner, J. et al. Appl. Polym. Sci: Appl. Poly. Symp. 45, 1-24 (1990), L .; Wild, Adv. Polym. Sci. 98, 1-47 (1990), J .; B. P. Soares, A .; E. A detailed measurement method is shown in Hamielec, Polymer; 36, 8, 1639-1654 (1995).

In the present invention, the measurement is specifically performed 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 TREF column at 140 ° C., 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 passed 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.
A component having a low elution temperature has a low crystallinity and is highly flexible. On the other hand, a component having a high elution temperature has a high crystallinity, thereby increasing rigidity and improving heat resistance. In the elution curve (elution amount dwt% / dT curve with respect to temperature) of the propylene-ethylene random block copolymer according to the present invention, a crystalline propylene-ethylene random copolymer component (A) and a low crystal The crystalline or amorphous propylene-ethylene random copolymer component (B) is observed as a component eluting at different temperatures due to the difference in crystallinity. That is, component (A) is observed on the high temperature side because of high crystallinity, and component (B) is observed on the low temperature side because it is low crystalline or amorphous, or does not show a peak within the TREF measurement temperature. When each peak temperature is T (A) and T (B) (when the peak is not shown, the lower limit of the measurement temperature is −15 ° C.), the temperature T (C) between the two peaks ({T (A) In + T (B)} / 2), both components are almost separable.

At this time, in TREF, the integrated amount of the components eluted up to T (C) is defined as W (B) wt%, and the integrated amount of the portion eluted at T (C) or higher is defined as W (A) wt%. W (B) substantially corresponds to the amount of the low crystallinity or amorphous component (B), and W (A) substantially corresponds to the amount of the high crystallinity component (A).
Here, since the flexibility of the block copolymer is improved by increasing the amount of the component (B), W (B) needs to be at least 30 wt% in order to exhibit the flexibility that is the object of the present invention. Yes, preferably 40 wt% or more.
When the component (B) is less than 30 wt%, the flexibility cannot be sufficiently exhibited, or in order to make it flexible, it is necessary to extremely reduce the crystallinity of the component (A), and the crystal melting temperature is accordingly increased. Since it becomes too low, heat resistance is deteriorated.
On the other hand, if the amount of the component (B) is too large, the amount of the component (A) necessary for maintaining the heat resistance becomes too small and the heat resistance is significantly deteriorated. % Or less, preferably 65 wt% or less.
As a result, W (B), which is the amount of component (B) in the present invention, needs to be in the range of 30 to 70 wt%, more preferably 40 to 65 wt%. Further, W (A), which is the amount of component (A), needs to be in the range of 70 to 30 wt%, more preferably 60 to 35 wt%.
The prescribed significance that W (B) is 30 to 70 wt% and W (A) is 70 to 30 wt% is also demonstrated from a comparison between Examples and Comparative Examples described later.

  Next, it fractionates into the component (B) of a T (C) soluble component, and the component (A) of a T (C) insoluble component by a temperature rising column fractionation method using a preparative type separation apparatus. The specific method of fractionation is based on T (C) determined by TREF measurement, and by using a preparative fractionator, a temperature rising column fractionation method is used to determine the components (B) and T (C) of T (C) soluble components. ) Fractionate into insoluble component (A), and determine the ethylene content of each component by NMR. The temperature rising column fractionation method refers to a measurement method disclosed in, for example, Macromolecules, 21, 314-319 (1988).

As the separation conditions, a glass bead carrier (80 to 100 mesh) is packed in a cylindrical column having a diameter of 50 mm and a height of 500 mm, 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 rate of temperature decrease of 10 ° C./hour. After holding at 0 ° C. for 1 hour, the column temperature is heated to T (C) 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 (C), 800 mL of o (dichlorobenzene) of T (C) is allowed to flow at a flow rate of 20 mL / min, whereby components soluble in T (C) existing in the column are obtained. Elute and collect.
Next, the column temperature is increased to 140 ° C. at a rate of temperature increase of 10 ° C./min, left at 140 ° C. for 1 hour, and then 800 mL of 140 ° C. solvent o-dichlorobenzene is flowed at a flow rate of 20 mL / min. , And eluting and recovering insoluble components at T (C).
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 collected by filtration and dried overnight in a vacuum dryer.
An example of the elution curve and elution integration described in detail above is illustrated in FIG. FIG. 1 is an actual measurement diagram in Example-1 described later. Referring to FIG. 1, the relationship between the above-described T (A), T (B), T (C) and the elution amounts W (A) and W (B) in the component (A) and the component (B). Becomes clear.
Then, the ethylene content of each fractionated component is determined by NMR. A specific method is shown below.

C. Measurement of ethylene content by NMR The ethylene content of each of component (A) and component (B) obtained by the above fractionation should be analyzed by a ¹³ C-NMR spectrum measured according to the following conditions by the proton complete decoupling method. Ask for.
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 spectral assignments measured under the above conditions are as shown in Table 1 below. In the table S is the symbol such as _{alpha alpha} Carman et al (Macromolecules, 10,536 (1977)) in accordance with notation, P is represented each methyl carbon, S is methylene carbon, T is a methine carbon.

Hereinafter, when “P” is a propylene unit in a copolymer chain and “E” is an ethylene unit, six kinds 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 and I indicates the spectral intensity. 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 consider these peaks derived from heterogeneous bonds and include them in the calculation. Therefore, the ethylene content of the present invention is obtained by using the relational expressions (1) to (7) as in the analysis of the copolymer produced with a Ziegler-Natta catalyst that does not substantially contain a heterogeneous bond. I will do it.
Conversion from mol% to wt% of ethylene content is carried out using the following formula: ethylene content (wt%) = (28 × X / 100) / {28 × X / 100 + 42 × (1−X) / 100 } × 100
Here, X is the ethylene content in mol%.
The ethylene content of the entire block copolymer is the weight of each component calculated from the ethylene contents [E] A, [E] B, and TREF of the components (A) and (B) measured above. It is calculated from the ratios W (A) and W (B) [wt%] by the following formula.
[E] W = [E] A × W (A) / 100 + [E] B × W (B) / 100 (wt%)

2. Solid viscoelasticity measurement
2. -(1) Definition by tan δ peak In the present invention, in the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA), it is necessary that tan δ has a single peak at 0 ° C. or less. is there.
Whether or not the copolymer has a phase separation structure can be discriminated in the temperature-tan δ curve in the measurement of solid viscoelasticity. To avoid the phase separation structure that affects the transparency of the molded product, tan δ is 0 ° C. or less. This is caused by having a single peak.
In order for the propylene-ethylene random block copolymer of the present invention to exhibit transparency, it is necessary that the temperature-tan δ curve in solid viscoelasticity measurement has a single peak at 0 ° C. or less. Is 0 ° C. or lower, preferably −5 ° C. or lower, more preferably −10 ° C. or lower in order to exhibit cold resistance.
Examples of tan δ curve peaks are shown in FIGS.

2. -(2) Measurement method 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 (G ′, G ″ in FIGS. 2 to 4), and the loss tangent tan δ (= loss elastic modulus / When storage modulus is plotted against temperature, it shows a sharp peak in the temperature range below 0 ° C. Generally, the tan δ peak below 0 ° C. is a glass transition of the amorphous part. The temperature is defined as the glass transition temperature Tg (° C.).

By lowering the glass transition temperature, embrittlement when the temperature is lowered is suppressed, and the block copolymer showing a glass transition temperature of 0 ° C. or lower, −5 ° C. or lower, and further −10 ° C. or lower of the present invention. The polymer exhibits the feature of excellent impact resistance at low temperatures.
On the other hand, when the copolymer has a phase separation structure, the glass transition temperature of the amorphous part contained in the component (A) and the glass transition temperature of the amorphous part contained in the component (B) are different from each other. Are plural (see FIG. 4). In this case, since the glass transition temperature of the propylene-ethylene random copolymer phase having a high ethylene content is extremely low, the impact resistance at low temperatures is improved, but the transparency is deteriorated, and as in the present invention. It is impossible to achieve both transparency and impact resistance at low temperatures.

2. -(3) Storage elastic modulus G 'at 23 ° C (23)
The block copolymer of the present invention has a storage elastic modulus G ′ (23) [MPa] at 200 ° C. of 200 (in a temperature-storage elastic modulus (G ′) curve obtained by solid viscoelasticity measurement (DMA). 200 × 10 ⁶ Pa) or less, which is exemplified in FIG. 2 (note that FIG. 2 is an actual measurement diagram in Example-1 described later).
G ′ (23) [MPa] is preferably 180 or less, more preferably 150 or less.
The storage elastic modulus G ′ (23) [MPa] at 23 ° C. represents the flexibility at room temperature. The larger this value, the lower the flexibility of the block copolymer, and G ′ (23) [MPa] is Since the flexibility is insufficient at 200 or more, the flexibility that is one object of the present invention cannot be exhibited.

2. -(4) Softening point temperature Tα
Moreover, although the softening point temperature showing heat resistance can be measured by various measuring methods, in this invention, softening point temperature was calculated | required from solid viscoelasticity measurement.
That is, the sample heated above the glass transition temperature in the solid viscoelasticity measurement softens as the temperature rises, and as a result, the storage elastic modulus generally decreases monotonically with the increase in normal temperature (G in FIG. 2). ').
At this time, in the semi-crystalline resin such as the block copolymer of the present invention, the amorphous part is constrained by the crystal structure, so that the temperature rises to some extent and crystal softening occurs until crystal melting starts. However, as the crystal melting starts, the sample suddenly softens, and a decrease in storage elastic modulus and an increase in tangent loss (tan δ in FIG. 2) are observed. On the other hand, when the proportion of the amorphous part is large and the restraint due to the crystal structure is weak, the degree of softening of the sample is large due to the increase in the mobility of the amorphous part due to the temperature rise, and the storage modulus at a lower temperature than the start of crystal melting Decrease and increase in tangent loss are observed.

Therefore, in the present invention, the temperature at which the storage elastic modulus G ′ decreases as the temperature increases and the softening progresses until the numerical value reaches 2 MPa is defined as Tα, which is defined as the softening point temperature (see FIG. 2).
Since the block copolymer of the present invention is excellent in heat resistance, the softening point temperature Tα needs to be 100 ° C. or higher, preferably 105 ° C. or higher, more preferably 110 ° C. or higher. At this time, since the DSC crystal melting temperature cannot be in the range of 145 ° C. or higher from the balance with flexibility, the upper limit of Tα is also 140 ° C.

3. Δ (Tm-Tα)
In the block copolymer of the present invention, the block copolymer having the softening point temperature as described above has heat resistance, while regarding the crystal melting, the DSC melting peak temperature Tm is in the range of 105 to 145 ° C. And has the feature of being easily melted.
In the present invention, the difference (Δ (Tm−Tα)) between the melting peak temperature Tm of the block copolymer and the softening point temperature Tα in the melting curve obtained by a differential scanning calorimeter (DSC) is 20 ° C. or less. It is necessary to be.
Here, as Δ (Tm−Tα) is smaller, the molding temperature can be lowered while having heat resistance. However, in the present invention, Δ (Tm−Tα) is 20 ° C. or less and has heat resistance. It can be said that the material is very easy to mold.
The polymer having such a softening point temperature is obtained by using a metallocene catalyst and a specific crystalline propylene-ethylene random copolymer component (A) and a specific low crystalline or amorphous propylene-ethylene random copolymer. The coalescence component (B) can be obtained by producing by multistage polymerization while maintaining a specific relationship.

4). 3. Molecular weight of block copolymer -(1) Regulation in molecular weight In the present invention, preferably, the weight average molecular weight Mw of the block copolymer obtained by gel permeation chromatography (GPC) measurement is in the range of 100,000 to 400,000. It is also characterized in that the component amount W (M ≦ 5,000) having a molecular weight of 5,000 or less is 0.8 wt% or less of the whole.
The block copolymer in the present invention is characterized in that it has few low molecular weight components. 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 a 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.

4). -(2) Molecular weight measurement In this invention, a weight average molecular weight (Mw) and a number average molecular weight (Mn) say what was measured by the gel permeation chromatography (GPC) method.
Conversion from the retention volume to the molecular weight is performed using a standard curve prepared in advance by 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. The following numerical value is used for [η] = K × M ^α in the viscosity formula used for conversion to molecular weight.
PS: K = 1.38 × 10 ⁻⁴ α = 0.7
PE: K = 3.92 × 10 ⁻⁴ α = 0.733
PP: K = 1.03 × 10 ⁻⁴ α = 0.78
The measurement conditions for GPC are as follows.
Apparatus: GPC (ALC / GPC 150C) manufactured by WATERS
Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
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.
FIG. 5 schematically shows a baseline definition method in a chromatogram of GPC measurement.
From the plot of the elution ratio against the molecular weight obtained by GPC measurement, the amount of components having a molecular weight of 5,000 or less can also be determined.
In order to obtain such a block copolymer having a low molecular weight component, there is a method of washing the produced block copolymer with a solvent, but in this case, productivity is remarkably lowered. It is also possible to increase the average molecular weight to suppress the generation of the low molecular weight side, but when the average molecular weight is increased, the viscosity of the entire block copolymer becomes too high, resulting in deterioration of moldability. In order to solve this problem, it is possible to control the rheology with the organic peroxide, but there arises a problem that the odor becomes worse due to the decomposition product of the organic peroxide.

5). Intrinsic viscosity [η] cxs
In the present invention, the intrinsic viscosity [η] cxs measured in 135 ° C. decalin of the 23 ° C. xylene-soluble component is specified to be in the range of 1 to 2 [dl / g] as necessary.
In block copolymers, stickiness and bleed-out are particularly problematic because they are components (CXS components) that are soluble in xylene at room temperature. Therefore, the intrinsic viscosity [η] (dl / g) is measured using the CXS component. It is preferable to carry out with respect to.
Here, the CXS component is prepared by dissolving the block copolymer in p-xylene at 130 ° C. to form a solution, and then leaving it at 25 ° C. for 12 hours, filtering the precipitated polymer, and evaporating p-xylene from the filtrate. The intrinsic viscosity [η] cxs of the obtained CXS component can be measured using Decalin as a solvent at a temperature of 135 ° C. using an Ubbelohde viscometer.
At this time, since the block copolymer of the present invention does not increase the generation of a component having a molecular weight of 5,000 or less that tends to bleed out, the conventional Ziegler-Natta catalyst has problems such as manufacturing problems and blocking. Even if the intrinsic viscosity [η] cxs of the CXS component, which has a practical problem due to deterioration, is in the region of 2 or less, it can be produced and used without causing any particular deterioration in physical properties.
Such a block copolymer that does not increase the component having a molecular weight of 5,000 or less while reducing 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. And the appearance of less appearance defects called fish eyes. In addition, the propylene-ethylene random block copolymer of the present invention has a low molecular weight component even in a low crystalline component or an amorphous component which causes a problem due to being particularly sticky when bleeding out by specifying a catalyst and polymerization conditions. Since there is little production | generation of, it has the characteristics that the intrinsic viscosity of a low crystalline or an amorphous component can be lowered | hung.

6). Metallocene catalyst
The method for producing the propylene-ethylene random block copolymer of the present invention requires the use of a metallocene catalyst, and the Ziegler-Natta catalyst is an excellent propylene-ethylene random block copolymer of the present invention. It is clear from comparison between the examples and comparative examples described later that the above cannot be obtained.
The type of the metallocene-based catalyst is not particularly limited as long as the copolymer having the performance of the present invention can be produced. However, in order to satisfy the requirements of the present invention, for example, the following components ( It is preferable to use a metallocene catalyst comprising A), (B), and component (C) used as necessary.
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) Solid component of seed (b-1) Fine particle carrier on which organoaluminum compound is supported (b-2) An ionic compound capable of reacting with component (A) to convert component (A) into a cation or (B-3) Solid acid fine particles (b-4) Ion exchange layered silicate Component (C): Organoaluminum compound

6). -(1) 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 -aR 1}} ) (C 5 H 4 -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 a hydrogen atom, a halogen atom, An 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 is shown, and X and Y may be independently, ie, the same or different. R ¹ and R ² are 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. Show. 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, Q has a divalent hydrocarbon group, a silylene group, an oligosilylene group, or a hydrocarbon group as a substituent. Examples include a silylene group, an oligosilylene group, or a germylene group having a hydrocarbon group as a substituent. Among these, preferred are a divalent hydrocarbon group and a silylene group having 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. X and Y may be independent of each other, that is, may be the same or different.
R ¹ and R ² are 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. Represents. 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, 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 includes a methoxy group, an ethoxy group, a phenoxy group. Typical examples include trimethylsilyl group, diethylamino group, diphenylamino group, pyrazolyl group, indolyl group, dimethylphosphino group, diphenylphosphino group, diphenylboron group, and 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 copolymer of the present invention is a substituted cyclopentadienyl crosslinked with a silylene group, a germylene group or an alkylene group having a hydrocarbon substituent. Is a transition metal compound comprising a ligand having a group, a substituted indenyl group, a substituted fluorenyl group, or a substituted azulenyl group, and particularly preferably 2,4-bridged with a silylene group having a hydrocarbon substituent or a germylene group. It is a transition metal compound comprising a ligand having a position-substituted 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-isopropyl-4-phenanthrylindenyl) zirconium dichloride, dimethyl Silylene bis (2-methyl-4-phenylazulenyl) zirconium dichloride, dimethylsilylene bis {2-methyl-4- (4-chlorophenyl) azurenyl} zirconium dichloride, dimethylsilyl Bis (2-ethyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis (2-isopropyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis {2-ethyl-4- (2-fluorobiphenyl) azurenyl} Zirconium dichloride, dimethylsilylenebis {2-ethyl-4- (4-t-butyl-3-chlorophenyl) azurenyl} zirconium dichloride, and the like can be given. 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 thereby. It is.

6). -(2) 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, and the like.
Here, as the fine particulate simple substance used for component (b-1) and 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 simple substances such as polypropylene, polyethylene, polystyrene, styrene divinyl benzene copolymer, and acrylic acid copolymer.
Further, as a non-limiting specific example of the component (B), a particulate carrier on which methylalumoxane, isobutylalumoxane, methylisobutylalumoxane, aluminum butylboronate tetraisobutyl, etc. are supported as the component (b-1). As component (b-2), triphenylborane, tris (3,5-difluorophenyl) borane, tris (pentafluorophenyl) borane, triphenylcarbonium tetrakis (pentafluorophenyl) borate, N, N-dimethyl Particulate carrier carrying anilinium tetrakis (pentafluorophenyl) borate, etc. as component (b-3), alumina, silica alumina, magnesium chloride, etc. as component (b-4), montmorillonite, zakonite, beidellite , Nontronic , Saponite, 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.

6). -(3) 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.

6). -(4) Formation of catalyst Component (A), component (B) and, if necessary, component (C) are brought into contact to form a catalyst. The contact method is not particularly limited, but can be contacted in the following order. Further, 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 bringing component (B) and component (C) into contact. In addition, three components may be contacted at the same time.

The amount of components (A), (B) and (C) used in the present invention 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 transition metal is 0.001 to 100 μmol, particularly preferably 0.005 to 50 μmol, relative to 1 g of component (C). Therefore, the amount of component (C) to component (A) is preferably in the range of 10 ⁻⁵ to 50, particularly preferably 10 ^{−4 to} 5 in terms of the molar ratio of the transition metal.

It is preferable that the catalyst of the present invention is subjected to a prepolymerization treatment comprising a small amount of polymerization by contacting an olefin in advance. 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 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.

7). Polymerization Method 7- (1) Sequential Polymerization In carrying out the present invention, a crystalline propylene-ethylene random copolymer component (A) and a low crystalline or amorphous propylene-ethylene random copolymer component (B ) Must be polymerized sequentially. Here, sequential polymerization means that both components are polymerized sequentially, a method of polymerizing component (B) after polymerizing component (A), or a component after polymerizing component (B). Any method of polymerizing (A) may be used. In the present invention, since a copolymer having a low molecular weight and easily sticking alone may be used as the component (B), the component (A) is polymerized after the component (A) is polymerized in order to prevent problems such as adhesion to the reactor. It is desirable to use a method of polymerizing B).
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.
If sequential polymerization is not employed and single polymerization or mechanical blending is used, the effects of the present invention cannot be obtained.
In the case of a batch method, it is possible to polymerize component (A) and component (B) separately using a single reactor by changing the polymerization conditions with time. As long as the effects of the present invention are not impaired, 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 or in parallel because it is necessary to polymerize component (A) and component (B) separately, but this hinders the effects of the present invention. Unless otherwise specified, a plurality of reactors may be connected in series and / or in parallel for each of the component (A) and the component (B).

7). -(2) Polymerization process The polymerization process can use arbitrary polymerization methods, such as a slurry method, a bulk method, and a gaseous-phase method. Although supercritical conditions can be used 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 particular distinction.
Since the low crystalline or amorphous propylene-ethylene random copolymer component (B) 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 (B). .
For the production of the crystalline propylene-ethylene random copolymer component (A), there is no particular problem even if any process is used, but in the case of producing the component (A) having relatively low crystallinity. In order to avoid problems such as adhesion, it is desirable to use a vapor phase method.
Therefore, using a continuous method, first, a crystalline propylene-ethylene random copolymer component (A) is polymerized by a bulk method or a gas phase method, and then a low-crystalline or amorphous propylene-ethylene random copolymer component is polymerized. It is most desirable to polymerize the polymer elastomer component (B) by a gas phase method.

7). -(3) Other 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, 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 from 0 to 200 MPa, preferably 0.1 to 50 MPa can be used. At this time, it is also preferable that an inert gas such as nitrogen coexists.
When the sequential polymerization of the component (A) in the first step and the component (B) in the second step is performed, it is preferable 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 the reactor for carrying out the ethylene-propylene random copolymerization in the second step, the particle properties (fluidity etc.) of the resulting powder, gel, etc. Can improve the product quality. Various technical studies have been made on this technique, and examples thereof include JP-B 63-54296, JP-A 7-25960, and JP-A 2003-2939. It is desirable to apply the method to the present invention.

8). Next, a method for controlling each element of the present invention will be described in detail. In the present invention, each element of the invention can be controlled to produce the propylene-ethylene block copolymer of the present invention. Therefore, such control is important for producing the novel propylene-ethylene block copolymer of the present invention, which is defined by various components such as melting peak temperature, ethylene content or solid viscoelasticity measurement.

8). -(1) Summary of Control As a preferred typical embodiment of the method for controlling the constituent elements of the invention in the present invention, Tm (A) is used in the sequential polymerization of component (A) and component (B) using a metallocene catalyst. (A) is controlled by the range of the ethylene content of component (A), and the amount ratio of component (A) to component (B) is controlled by the production amount in the first step and second step, and component (A) and component (B) The ethylene content in the first step and the second step is controlled by the amount of ethylene supplied to propylene, and the difference in ethylene content between the component (A) and the component (B) is 15% by weight or less. The range of the ethylene content of component (A) and component (B) is set to G ′ in condition (ii), Tα in condition (iii), and Δ (Tm−Tα) in condition (iv). Block polymerization under the condition (v) Mw of the component (A) is controlled by the viscosity [η] of the component (A), and the block polymer component amount W (M ≦ 5,000) in the condition (v) is transferred in the transfer step from the first step to the second step. And the monomer gas management, and the intrinsic viscosity [η] cxs of the condition (vi) is controlled by adjusting the molecular weight in the second step.

8). -(2) Control of Tm (A) Tm (A) is a melting peak temperature obtained by DSC measurement in the component (A), and a melting peak temperature Tm by a differential scanning calorimeter (DSC) at 105 to 145 ° C. Although identified as (A), it is controlled by adjusting the range of the ethylene content of component (A).
Since the component (A) of the present invention is a component of a propylene-ethylene random copolymer, the higher the ethylene content [E] A in the component (A), the lower the Tm and the lower [E] A. The Tm becomes higher. Therefore, in order to satisfy Tm within the scope of the present invention, [E] A and the relationship between them may be grasped and [E] A may be controlled to be within a predetermined range. The relationship between the amount ratio of propylene and ethylene supplied to the polymerization tank and the ethylene content in the resulting propylene-ethylene random copolymer varies depending on the type of metallocene catalyst used, but by adjusting the supply amount ratio as appropriate. Component (A) having any ethylene content [E] A can be produced. For example, when [E] A is controlled to 1 to 10 wt%, the supply weight ratio of ethylene to propylene should be in the range of 0.001 to 0.3, preferably in the range of 0.005 to 0.2. It ’s fine.
The propylene-ethylene random block copolymer having such a component (A) has a melting peak temperature Tm obtained by DSC measurement of 105 to 140 ° C, more preferably 110 to 135 ° C. It has a low melting point and can be processed at a low temperature.
In order to make Tm (A) in such a range, the ethylene content in component (A) is controlled so that the ethylene content is about 1 to 10 wt%, preferably 1.5 to 6 wt%. That's fine.

8). -(2) Quantity ratio of component (A) and component (B) In order to make the quantity ratio of component (A) and component (B) 30-70 wt% / 70-30 wt%, component (A) and It controls by the manufacturing amount in the 1st process and 2nd process of a component (B).
That is, the amount W (A) of the component (A) and the amount W (B) of the component (B) change the ratio of the production amount of the first step for producing the component (A) and the production amount of the component (B). Can be controlled. For example, in order to increase W (A) and reduce W (B), 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 decreasing the polymerization temperature or increasing the amount of the polymerization inhibitor. The reverse is also true.

8). -(3) Ethylene content of component (A) and component (B) The ethylene content of component (A) and component (B) can be controlled by the amount of ethylene supplied to propylene in the first step and the second step, respectively.
When actually setting the conditions, it is necessary to consider the activity decay. That is, in the range of the ethylene contents [E] A and [E] B 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] A is increased and the production amount W (A ), If necessary, lower the polymerization temperature and / or shorten the polymerization time (residence time), or increase the ethylene content [E] B in the second step and increase the production W (B) If necessary, the conditions may be set by a method that raises the polymerization temperature and / or lengthens the polymerization time (residence time).

8). -(4) Tg peak in temperature-loss tangent (tan δ) curve The block copolymer of the present invention needs to have a single Tg peak at 0 ° C or lower in the temperature-loss tangent (tan δ) curve. Yes, in order for Tg to have a single peak, the difference between the ethylene content [E] A in component (A) and the ethylene content [E] B in component (B) = [E] B- [E] A) may be 15 wt% or less, preferably 13 wt% or less. Depending on the ethylene content [E] A of the crystalline copolymer component (A), the [E] B content of the low crystalline or amorphous copolymer component (B) is within the proper range. It is possible to obtain a polymer having a predetermined [E] gap by setting the supply weight ratio of ethylene to propylene during the polymerization of component (B).
The Tg of the block copolymer that does not take a phase separation structure as in the present invention is the ethylene content [E] A in the component (A), the ethylene content [E] B in the component (B), and It is affected by the ratio of both components. In the present invention, the amount of the component (B) is 30 to 70 wt%, but in this range, Tg is more strongly affected by the ethylene content [E] B in the component (B).
That is, Tg reflects the glass transition of the amorphous part. In the block copolymer of the present invention, the component (A) has crystallinity and relatively few amorphous parts, whereas the component (B). This is because they are low crystalline or amorphous and most of them are amorphous parts.
Therefore, the value of Tg is controlled almost by [E] B, and the control method of [E] B is as described above in paragraph 0059.

8). -(5) Storage elastic modulus G '(23)
The copolymer of the present invention has a storage elastic modulus G ′ (23) [MPa] at 23 ° C. of 200 or less in a temperature-storage elastic modulus (G ′) curve obtained by solid viscoelasticity measurement (DMA). And the storage modulus G ′ (23) is controlled by the ethylene content of component (A) and component (B).
The storage elastic modulus G ′ (23) [MPa] at 23 ° C. represents the flexibility at room temperature. The larger this value, the lower the flexibility of the block copolymer, and G ′ (23) [MPa] is Since the flexibility is insufficient at 200 or more, the flexibility that is one object of the present invention cannot be exhibited.

8). -(6) Temperature Tα
The copolymer of the present invention requires that the temperature Tα at which G ′ becomes 2 MPa is in the range of 100 to 140 ° C., and Tα is W (A) within the range of the present invention of 30 wt% or more. In the region, since it is mainly controlled by crystal relaxation, it is almost determined by the melting point Tm (A) of the crystalline propylene-ethylene random copolymer component (A) and is therefore generally controlled by [E] A.
On the other hand, as described above, when W (B) is 70 wt% or more, Tα is drastically lowered. Therefore, in order to maintain Tα, W (B) must be controlled to be 70 wt% or less.
What is important is that when softening, W (B) is increased within a range of 70 wt% or less, and [E] A is increased to reduce the thickness of the crystal lamella for the amount insufficient for the target flexibility. Is to control the whole in a way. At this time, it is necessary to keep [E] gap within a certain range in order to maintain transparency, and when changing [E] A, forget to change [E] B in the same direction at the same time. Don't be. Since the threshold value of W (B) at which Tα rapidly decreases is somewhat influenced by [E] A, it is necessary to finely adjust W (B) in accordance with [E] A. In other words, when making Tα more flexible while maintaining Tα, the ethylene content [E] A is increased in the first step and the production amount W (A) is decreased, or the ethylene content [E] in the second step. What is necessary is just to take the method of raising B and raising the production amount W (B).

When actually setting the conditions, as described in paragraph 0059, it is necessary to consider the decay of activity. That is, in the range of the ethylene contents [E] A and [E] B carried out in the present invention, generally, in order to increase the ethylene content, if the ratio of ethylene supply to propylene is increased, the polymerization activity increases and simultaneously the activity is increased. Attenuation 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] A is increased and the production amount W (A) If necessary, lower the polymerization temperature and / or shorten the polymerization time (residence time) or increase the ethylene content [E] B in the second step and increase the production W (B). Accordingly, the conditions may be set by a method of increasing the polymerization temperature and / or increasing the polymerization time (residence time).
A method of hardening Tα while maintaining it and a method of increasing or decreasing Tα while maintaining flexibility can be controlled by the same concept.

8). − (7) Δ (Tm−Tα)
The block copolymer of the present invention is required to have a difference between melting peak temperatures Tm and Tα (Δ (Tm−Tα)) of 20 ° C. or less in a melting curve obtained by a differential scanning calorimeter (DSC). Yes, this can be done by combining the control of Tm (A) described in paragraph 0057 with the control of Tα described in paragraphs 0062-0063.

8). -(8) Molecular weight Mw and M≤5,000
The copolymer of the present invention has a weight average molecular weight Mw of a block copolymer obtained by gel permeation chromatography (GPC) measurement in the range of 100,000 to 400,000, and a molecular weight of 5,000 or less. The component amount W (M ≦ 5,000) is preferably 0.8 wt% or less of the whole.
In the propylene-ethylene random block copolymer of the present invention, the compatibility between the crystalline copolymer component (A) and the low crystalline or amorphous copolymer elastomer component (B) in order to maintain transparency. Since the viscosity [η] A of the component (A), the viscosity [η] B of the component (B), and the viscosity [η] W of the propylene-ethylene random block copolymer are The apparent viscosity mixing rule is generally true. That is,
{W (A) + W (B)} × Log [η] W = W (A) × Log [η] A + W (B) × Log [η] B
Is generally established. Generally, since there is a certain correlation between Mw and [η], from the viewpoint of flexibility and heat resistance, [η] B, W (A), and W (B) are set first. Mw can be freely controlled by changing [η] A according to the above equation.

  Regarding the component amount W (M ≦ 5,000) having a molecular weight of 5,000 or less, the molecular weight distribution is generally narrower than that of the Ziegler-Natta catalyst by using a metallocene catalyst, and W (M ≦ 5, However, in a system that performs sequential polymerization as in the present invention, it is not always sufficient to use a metallocene catalyst in order 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 changed with an inert gas such as nitrogen in the transfer step. It is necessary to control W (M ≦ 5,000) to be small independently of the polymerization conditions by completely replacing it.

8). -(9) Intrinsic viscosity [η] cxs
The copolymer of the present invention preferably has an intrinsic viscosity [η] cxs of a 23 ° C. xylene-soluble component measured in 135 ° C. decalin within a range of 1 to 2 [dl / g].
[η] cxs can be controlled by changing the molecular weight Mw of the component (B). 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, since the metallocene catalyst tends to have a lower molecular weight of the polymer as the polymerization temperature is higher, it is also possible to control [η] cxs by changing the polymerization temperature. [Η] cxs can also be controlled by combining both the hydrogen supply ratio and the polymerization temperature.

9. -Additional ingredients (additives)
In the propylene-ethylene block copolymer of the present invention, in order to add various functions to the block copolymer, an additive component (arbitrary component) is used as an additive so long as the effects of the present invention are not significantly impaired. It can also be blended.
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 agents, lubricants, antistatic agents, metal deactivators, peroxides, fillers, antibacterial and antifungal agents, and optical brighteners can be added.
The amount of these additives is generally 0.0001 to 3 wt%, preferably 0.001 to 1 wt%.

Specific examples of the nucleating agent include sodium 2,2-methylene-bis (4,6-di-t-butylphenyl) phosphate, talc, 1,3,2,4-di (p-methylbenzylidene) sorbitol, etc. Sorbitol compound, hydroxy-di (aluminum t-butylbenzoate, 2,2-methylene-bis (4,6-di-t-butylphenyl) phosphoric acid and aliphatic monocarboxylic acid lithium salt mixture having 8 to 20 carbon atoms (Trade name NA21 manufactured by Asahi Denka Co., Ltd.).
Specific examples of phenolic antioxidants include tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, 1,1,3-tris (2-methyl-4-hydroxy-5). -T-butylphenyl) butane, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis {3- (3,5-di-t-butyl-4 -Hydroxyphenyl) propionate}, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 3,9-bis [2- {3 -(3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] unde Emissions, such as 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid.
Specific examples of phosphorus antioxidants include tris (mixed, mono-dinonylphenyl phosphite), tris (2,4-di-t-butylphenyl) phosphite, 4,4′-butylidenebis (3- Methyl-6-tert-butylphenyl-di, tridecyl) phosphite, 1,1,3-tris (2-methyl-4-di, tridecylphosphite-5-tert-butylphenyl) butane, tetrakis (2, 4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,4-di-t-butyl-5-methylphenyl) -4,4'-biphenylenediphosphonite, etc. be able to.
Specific examples of the sulfur-based antioxidant include di-stearyl, thio, di-propionate, di-myristyl, thio, di-propionate, pentaerythritol, tetrakis- (3-lauryl, thio-propionate) and the like. it can.
Specific examples of the neutralizing agent include calcium stearate, zinc stearate, hydrotalcite, and Mizukarak (manufactured by Mizusawa Chemical Co., Ltd.).
Specific examples of hindered amine stabilizers include polycondensates of dimethyl oxalate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, tetrakis (1,2 , 2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, N, N- Bis (3-aminopropyl) ethylenediamine · 2,4-bis {N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino} -6-chloro-1,3,5 -Triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, poly {6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine -2 4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}, poly (6-morpholino -S-triazine-2,4-diyl) {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino } Etc. can be mentioned.
Specific examples of the lubricant include higher fatty acid amides such as oleic acid amide, stearic acid amide, behenic acid amide, and ethylene bis stearoid, silicone oil, higher fatty acid ester, and the like.
Examples of the antistatic agent include higher fatty acid glycerin ester, alkyl diethanolamine, alkyl diethanolamide, alkyl diethanolamide fatty acid monoester and the like.
In addition, the effects of the present invention are remarkably impaired by resins other than the propylene-ethylene random block copolymer of the present invention such as ethylene / propylene rubber, ethylene / butene rubber, ethylene / hexene rubber, and ethylene / octene rubber. It can also be blended within a range not included. Resins other than those used in the present invention can be blended up to a maximum of 30 wt%, preferably 20 wt%.

These additional components can be directly added to the propylene-ethylene random block copolymer of the present invention obtained by polymerization and melt kneaded for use, or may be added during melt kneading. . Furthermore, it can be added directly after melt-kneading, or can be added as a master batch within a range that does not significantly impair the effects of the present invention. Moreover, you may add by these composite methods.
In general, additives such as antioxidants and neutralizing agents are blended, mixed, melted and kneaded before being molded into a product. It is also possible to add and use other resins or other additional components (including a masterbatch) as long as the effects of the present invention are not significantly impaired during molding.
For the mixing, melting, and kneading, any conventionally known methods can be used. Usually, Henschel mixer, super mixer, V blender, tumbler mixer, ribbon blender, Banbury mixer, kneader blender, uniaxial or biaxial kneading extrusion Can be implemented on the machine. Among these, it is preferable to perform mixing or melt-kneading with a uniaxial or biaxial kneading extruder.

10. Use and molding method of the present invention The propylene-ethylene random block copolymer of the present invention is excellent in flexibility and transparency, can be molded at low temperatures while the product has heat resistance, and has no stickiness or bleed. Since it has the feature of being suppressed, it is suitably used for films, sheets, laminates, various containers, various molded products, various coating materials and the like.
In particular, a film or sheet is suitable because bleeding is suppressed and the sticky feeling is remarkably reduced, so that blocking hardly occurs and the appearance is good.
Moreover, when used as various containers, the content contamination by bleed is very small, and it is suitable for food, medical and industrial fields.
Also as a molded article, there is no deterioration in appearance over time due to bleeding, and it can be suitably used.

As a molding method for these various products, a known molding method can be used without limitation.
Examples of film or sheet molding methods include air-cooled inflation molding, water-cooled inflation molding, non-stretching molding using a T-die, uniaxial stretching molding, biaxial stretching molding, and calendar molding.
Moreover, when using as a film or a sheet | seat, the use as a layer in a multilayer structure is also possible in a laminated body. That is, it can be used for the intermediate layer by taking advantage of its flexibility, and can also be used as a surface layer by taking advantage of its excellent strength without forming stickiness and bleed-out and enabling molding at low temperature.
As container molding, hot pressure molding, pressure molding, vacuum molding, vacuum pressure molding, blow molding, stretch blow molding, injection molding, or the like can be used.
In order to obtain a molded product, not only normal injection molding but also insert molding, sandwich molding, gas assist molding, and the like can be performed, and press molding, stamping molding, rotational molding, and the like can also be used.
Since these molded products have heat resistance, they are suitable for sterilization with hot water and use at relatively high temperatures, and not only do not deform, but also deteriorate transparency due to bleed-out when heat is applied. It also has the feature that it does not occur.

In order to describe the present invention more specifically, examples and comparative examples will be described below. However, the present invention is not limited by these examples.
The measuring methods of various physical properties of the block copolymers obtained in the following examples and comparative 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) Melting peak temperature Using a Seiko DSC, take 5.0 mg of sample, hold it at 200 ° C for 5 minutes, crystallize it to 40 ° C at a rate of temperature decrease of 10 ° C / minute, and further increase the temperature by 10 ° C / minute. The melting peak temperature when melted at a temperature rate was defined as Tm (unit: ° C.). DHm was determined from the area of the endothermic curve at the time of temperature increase.
3) Ethylene content of each component First, using the difference in crystallinity between component (A) and component (B), the temperature at which component (A) and component (B) are divided from the elution curve obtained by TREF measurement. decide. Next, it fractionates into the component (B) of a T (C) soluble component, and the component (A) of a T (C) insoluble component by a temperature rising column fractionation method using a preparative type separation apparatus. Then, the ethylene content of each fractionated component is determined by NMR. The NMR method is detailed in paragraphs 0028-0032.
4) TREF
A sample is dissolved in o-dichlorobenzene (containing 0.5 mg / mL BHT) at 140 ° C. to prepare 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 allowed to flow through the column at a flow rate of 1 mL / min, and components dissolved in o-dichlorobenzene at −15 ° C. in the TREF column. Elution is performed for 10 minutes, and then the column is linearly heated to 140 ° C. at a heating rate of 100 ° C./hour to obtain an elution curve.
[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: Micro flow cell for LC-IR Optical path length: 1.5 mm Window shape: 2φ x 4 mm long circle Synthetic sapphire window measurement temperature: 140 ° C
(Pump part)
Liquid feed pump: SSC-3461 pump manufactured by Senshu Kagaku Co. [Measurement conditions]
Solvent: o-orthodichlorobenzene (containing 0.5 mg / mL BHT)
Sample concentration: 5 mg / mL
Sample injection volume: 0.1 mL
Solvent flow rate: 1 mL / min 5) Solid viscoelasticity measurement Samples cut into 2 mm thick strips of 10 mm width × 18 mm length × 2 mm thickness were used as samples. The apparatus used was ARES manufactured by Rheometric Scientific. The frequency is 1 Hz. The measurement temperature was raised stepwise from −60 ° C., and 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%.
6) 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 standard curve prepared in advance by standard polystyrene.
The measurement method is the method detailed in paragraph 0041.
7) 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.
8) Intrinsic viscosity (synonymous with intrinsic viscosity)
Using an Ubbelohde viscometer, decalin was used as a solvent and the temperature was measured at 135 ° C.

[Production Example-1]
Preparation of prepolymerization catalyst Silicate chemical treatment: To a glass separable flask with a 10 liter stirrer blade, 3.75 liters of distilled water was added slowly followed by 2.5 kg of concentrated sulfuric acid (96%). At 50 ° C., montmorillonite (Mizusawa Chemical Benclay SL; average particle size =
1 kg of 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. The chemically treated silicate was dried by a kiln dryer.
Preparation of catalyst: 20 g of the dried silicate obtained above was introduced into a glass reactor equipped with a stirring blade having an internal volume of 1 liter, and 116 ml of mixed heptane and 84 ml of a heptane solution of triethylaluminum (0.60 M) were added. Stir at room temperature. 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 prepared silicate slurry and reacted at 25 ° C. for 1 hour. In parallel, [(r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azurenyl}] zirconium] (synthesized in JP-A-10-226712) (Performed according to the example) 3.31 ml of a heptane solution of triisobutylaluminum (0.71 M) was added to 218 mg (0.3 mmol) and 87 ml of mixed heptane, and the mixture reacted at room temperature for 1 hour was added to a silicate slurry. In addition, after stirring for 1 hour, mixed heptane was added to prepare 500 ml.
Prepolymerization: Subsequently, the previously prepared silicate / metallocene complex slurry was introduced into a stirring autoclave having an internal volume of 1.0 liter that had been 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 at 40 ° C. for 30 minutes, 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 conducted, the concentration of the organoaluminum component was 1.23 mmol / L and the Zr concentration was 8.6 × 10 ⁻⁶ g / L, and the abundance in the supernatant with respect to the amount charged. 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. By this operation, a prepolymerized catalyst containing 2.0 g of polypropylene per 1 g of catalyst was obtained. (Preparation polymerization catalyst was prepared by the method described in Example 1 of JP-A-2002-284808)
Using this prepolymerized catalyst, a propylene-ethylene random block copolymer was produced according to the following procedure.

First Step After fully 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, followed by 27 g of ethylene, 250 ml of hydrogen, and then 750 g of liquid propylene was introduced and the temperature was raised to 70 ° C. to maintain the temperature. The above prepolymerized catalyst was slurried with n-heptane, and 15 mg of the catalyst (excluding the weight of the prepolymerized polymer) was injected to initiate polymerization. Polymerization was continued for 20 minutes while maintaining the bath temperature at 70 ° 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 2.6 wt%, the MFR was 16.2 g / 10 min, the DSC melting peak temperature was Tm (A) 131 ° C., and the dHm (A) was 69 mJ / mg.
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 25.96 vol%, propylene 73.89 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 97 minutes at a polymerization temperature of 80 ° C. and a pressure of 2.5 MPaG. Thereafter, 10 ml of ethanol was introduced to terminate the polymerization. The recovered polymer was sufficiently dried in an oven. The yield was 313 g, the activity was 20.9 kg / g-catalyst, the ethylene content was 7.6 wt%, and the MFR was 16.2 g / 10 min.

[Production Example-2]
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, ethylene, and triisobutylaluminum were continuously fed at 90 kg / hr, 1.4 kg / hr, and 21.2 g / hr, respectively. Hydrogen was continuously supplied so that the concentration in the gas phase portion was 200 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. Further, the polymerization tank was cooled so that the polymerization temperature became 70 ° C.
When the propylene-ethylene random copolymer obtained in the first step was analyzed, BD (bulk density) was 0.48 g / cc, MFR was 16.2 g / 10 min, ethylene content was 1.1 wt%, DSC melting The peak temperature was Tm (A) 141 ° C. and dHm (A) 79 mJ / mg.
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 concentrations of propylene, ethylene, and hydrogen in the total partial pressure of propylene, ethylene, and hydrogen were controlled to be 76.93 vol%, 22.98 vol%, and 900 volppm, respectively. Furthermore, ethanol was supplied to the gas phase polymerization tank as an activity inhibitor. The amount of ethanol supplied was 0.4 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 16.6 kg / g-catalyst, BD was 0.43 g / cc, MFR was 16.6 g / 10 min, and the ethylene content was 6.1 wt. %Met.

[Production Examples 3 to 10]
Propylene-ethylene random block copolymer was produced in the same manner as Production Example-1. Table 3 shows the polymerization conditions and the polymerization results.

[Production Example-11]
Propylene-ethylene random copolymer was produced using the prepolymerization catalyst used in Production Example-1. After fully substituting propylene for a 3 L internal volume autoclave with stirring and temperature control device, 2.76 ml (2.02 mmol) of a triisobutylaluminum / n-heptane solution was added, followed by 27 g of ethylene, 250 ml of hydrogen, and then 750 g of liquid propylene. Was introduced and the temperature was raised to 70 ° C. to maintain the temperature. The above prepolymerized catalyst was slurried with n-heptane, and 25 mg of the catalyst (excluding the weight of the prepolymerized polymer) was injected to initiate polymerization. Polymerization was continued for 20 minutes while maintaining the bath temperature at 70 ° 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. Yield was 238 g, activity was 9.5 kg / g-catalyst, ethylene content 2.6 wt%, MFR 16.2 g / 10 min, DSC melting peak temperature Tm (A) 131 ° C., dHm (A) 69 mJ / mg.

[Production Examples 12-18]
Propylene-ethylene random block copolymer was produced in the same manner as in Production Example-1. Table 4 shows the polymerization conditions and the polymerization results.

[Production Example-19]
A propylene-ethylene random block copolymer was produced in the same manner as in Production Example 1 except that 70 g of ethylene, 250 ml of hydrogen, 35 mg of catalyst, and a polymerization temperature of 45 ° C. were used in the first step. When the residual monomer was purged at the end of the first step, a poor stirring occurred, and thus the second step was not performed and the polymerization was stopped. When the autoclave was opened, significant adhesion was confirmed. When a part of the sample was collected and analyzed, the ethylene content was 7.0 wt%.

[Production Examples-20 to 21]
A solid catalyst component was prepared by the method described in Example 1 of JP-A-11-80235. A propylene-ethylene random block copolymer was prepared in the same manner as in Production Example 1 except that this solid catalyst component was used and a triethylaluminum / n-heptane solution (4.82 mmol) was used instead of the triisobutylaluminum / n-heptane solution. A polymer was produced. The polymerization conditions and polymerization results are shown in Table 5.

[Example-1]
The following antioxidant and neutralizing agent were added to the block copolymer powder obtained in Production Example 1, and the mixture was sufficiently stirred and mixed.
Additive blended antioxidant: tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane 500 ppm, tris (2,4-di-t-butylphenyl) Phosphite 500ppm
Neutralizer: Calcium stearate 500ppm
The copolymer powder with the granulation additive added is melt-kneaded under the following conditions, the molten resin extruded from the strand die is taken out while being cooled and solidified in a cooling water tank, and the strand is about 2 mm in diameter using a strand cutter. The raw material pellet was obtained by cutting to about 3 mm in length.
Extruder: KZW-15-45MG twin-screw extruder manufactured by Technobel Co., Ltd .: 15 mm diameter L / D45
Extruder set temperature: (from below the hopper) 40 80 160 200 220 22
(Die) [℃]
Screw rotation speed: 400rpm
Discharge amount: Adjusted to 1.5 kg / h with a screw feeder Die: 3 mm diameter strand die 2 hole analysis Using the obtained raw material pellets, TREF, NMR ethylene content, DSC, GPC, CXS, CXS [ [η] was measured. Table 6 shows the parameters obtained by the measurement.
In order to show the positioning of each parameter for the TREFF measurement result, an elution curve is illustrated in FIG.
Molding The obtained raw material pellets were injection molded under the following conditions to obtain flat plate test pieces for evaluating physical properties.
Standard number: JIS-K7152 (ISO 294-1) Reference molding machine: TU-15 injection molding machine molding machine manufactured by Toyo Machine Metal Co., Ltd. Setting temperature: (from under the hopper) 80 160 200 200 200 ° C.
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 (thickness 2mm, width 30mm, length 90mm)
Measurement of Solid Viscoelasticity The solid viscoelasticity of the block copolymer was measured using the obtained injection molded article. Table 6 shows the parameters obtained by the measurement.

In order to show the position of each parameter in the solid viscoelasticity measurement results, FIG. 2 shows changes in storage elastic modulus G ′ [Pa], loss elastic modulus G ″ [Pa] and loss tangent tan δ with respect to temperature in Example-1. Is illustrated.
Evaluation of physical properties The physical properties of the obtained block copolymer were evaluated for the following items. The results are shown in Table 7.
Transparency The transparency of the obtained block copolymer was evaluated under the following conditions.
Standard number: JIS K-7136 (ISO14782), JIS K-7136-1 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 Molding section for molding)
Condition adjustment: After molding, the number of test pieces left for 24 hours in a temperature-controlled room adjusted to room temperature 23 ° C. and humidity 50%: n = 3
Evaluation items: haze (Haze), total light transmittance (Tt)
Tensile test The tensile properties of the obtained block copolymer were evaluated under the following conditions.
Standard number: JIS K-7162 (ISO 527-1) compliant testing machine: Precision universal testing machine Autograph AG-5kNG-with micro extensometer (manufactured by Shimadzu Corporation)
Specimen sampling direction: Flow direction Specimen shape: JIS K7162-5A type Specimen preparation method: Injection molded flat plate is punched into the above shape (see Molding section for molding)
Condition adjustment: Room temperature adjusted to 23 ° C. and humidity 50% for 24 hours or longer Test room: Number of temperature controlled specimens adjusted to room temperature 23 ° C. and humidity 50%: n = 5
Test speed: 1.0 mm / min (elongation up to 5 mm), 25.0 mm / min (elongation over 5 mm)
Evaluation Items: Tensile Elastic Modulus, Tensile Yield Stress, Tensile Fracture Stress, and Tensile Fracture Strain Impact Test The obtained block copolymer was impacted at high speed and the impact resistance was evaluated from the tensile behavior at that time. Evaluation conditions are shown below.
Tester: Servo pulsar high-speed impact tester EHF-2H-20L type-with thermostatic chamber (manufactured by Shimadzu Corporation)
Specimen sampling direction: Flow direction Specimen shape: JIS K7162-5A type Specimen preparation method: Injection molded flat plate is punched into the above shape (see Molding section for molding)
Condition adjustment: Number of test specimens for 24 hours or more in a temperature-controlled room adjusted to room temperature 23 ° C. and humidity 50%: n = 5
Tensile speed: 2m / sec
Measurement temperature: 23 ° C. and 0 ° C. (In the case of 0 ° C., set the temperature chamber to 0 ° C., set the sample and keep the temperature of the temperature chamber at the set temperature ± 1 ° C. for 10 minutes or more. Then measure)
Evaluation items: elongation at break and absorbed energy up to break = energy at break (elongation-area of tension diagram)
Evaluation of Stickiness The stickiness of the obtained block copolymer was evaluated by the following method in a thermostatic chamber adjusted to a room temperature of 23 ° C. and a humidity of 50%.
Two injection-molded flat plates (see the molding section for molding) are stacked between two steel plates, and 1 kg is applied to the steel plates and left for 10 minutes. The stickiness was evaluated.
The symbols in the table indicate the following states.
○: The sample did not stick, and peeled off immediately after removal. Δ: The sample was stuck, but it was easily peeled off by hand.
X: Evaluation of bleed-out in which the sample was in close contact and required considerable force to peel off The bleed-out of the obtained block copolymer was evaluated by the following method.
The surface of a test piece with a thickness of 2 mm obtained by injection molding is wiped clean with a cloth once within 24 hours after molding and then left in a constant temperature bath at 40 ° C. for 24 hours. Evaluated out.
The symbols in the table indicate the following states.
○: The sample had no bleed-out, and there was no change in the state before being left. △: Some bleed-out was observed in the sample, but it was not noticeable. is expected.
×: Many bleed-outs were observed in the sample, and marked whitening occurred on the surface

[Examples 2 to 8]
The same additives as in Example-1 were blended in the block copolymers obtained in Production Examples-2 to 8, respectively, and granulation and injection molding were performed under the same conditions. The physical properties were also evaluated under the same conditions for the same items. The results are shown in Tables 6 and 7.

[Example-9]
The block copolymer obtained in Production Example-9 was blended with the same additive as in Example-1. In the granulation, sharkskin was generated in the strand under the same conditions as in Example 1. Therefore, the temperature in the two zones from the tip was set to 230 ° C. Injection molding had a large sink under the conditions of Example 1, and a sample having a uniform thickness could not be obtained, so the holding pressure was increased to 1,200 kgf / cm ² . The physical properties were evaluated for the same items under the same conditions. The results are shown in Tables 6 and 7.

[Example-10]
The block copolymer obtained in Production Example-10 was blended with the same additive as in Example-1. For granulation, under the same conditions as in Example-9, sharkskin was generated in the strands, and the motor load increased. Therefore, the discharge rate was reduced to 1.0 kg / h 2. Injection molding has a large sink under the conditions of Example-9, and the holding pressure was increased to 2,000 kgf / cm ² because a sample having a uniform thickness could not be obtained. I couldn't get a sample.
The physical properties were evaluated for the same items under the same conditions. The results are shown in Tables 6 and 7.

[Comparative Examples-1 to 8]
Each of the random copolymer obtained in Production Example-11 and the block copolymer obtained in Production Examples-12 to 18 were blended with the same additives as in Example-1, and granulated and injected under the same conditions. Molding was performed. The physical properties were also evaluated under the same conditions for the same items. The results are shown in Tables 6 and 7.
The solid viscoelasticity measurement results of Comparative Examples 3 and 5 are shown in FIG. 3 and FIG. 4 as an example of behavior when heat resistance deteriorates and a case where phase separation and tan δ do not take a single peak.

[Comparative Example-9]
In the block copolymer obtained in Production Example-20, the same additive as in Example-1 was blended, and the granulation was performed under the same conditions as in Example-1. The temperature was 230 ° C. Injection molding had a large sink under the conditions of Example 1, and a sample having a uniform thickness could not be obtained, so the holding pressure was increased to 1,200 kgf / cm ² . The physical properties were evaluated for the same items under the same conditions. The results are shown in Tables 6 and 7.

[Comparative Example-10]
Since the same additive as in Example-1 was blended with the block copolymer obtained in Production Example-21, sharkskin was generated in the strand under the same conditions as in Comparative Example-8, and the motor load increased. The discharge rate was reduced to 1.0 kg / h. Injection molding increased the holding pressure to 2,000 kgf / cm ² because a sample with large sink marks and a uniform thickness could not be obtained under the conditions of Comparative Example-9, but uneven flow called flow marks occurred on the surface. A clean sample could not be obtained. The physical properties were evaluated for the same items under the same conditions. The results are shown in Tables 6 and 7.

[Comparative Example-11]
The block copolymer obtained in Production Example-20 is blended with the same additive as in Example-1 and further 2,5-dimethyl-2,5-bis (t-butylperoxy) as an organic peroxide. 0.05 part by weight of hexane was added and mixed with a super mixer for 3 minutes. This mixture was supplied to the twin-screw extruder used in Example 1, and after melt-kneading at a cylinder temperature of 200 ° C. and a screw rotation speed of 200 rpm, the strand was cut to obtain a pellet-shaped resin modified product.
The obtained pellets had a strong acid odor due to decomposition of organic peroxides or residuals, and had a yellowish hue. The MFR was 5.0 g / 10 minutes. The obtained pellets were injection molded under the same conditions as in Example-1. The physical properties were also evaluated under the same conditions for the same items. The results are shown in Tables 6 and 7.

[Consideration by contrast between Example and Comparative Example]
Considering each of the above Examples and Comparative Examples in contrast, in the novel propylene-ethylene block copolymer of the present invention that satisfies the respective provisions of the constitution of the present invention, transparency and tensile properties, etc. It is clear that the expressed flexibility is well balanced with heat resistance, the product is not sticky, bleed out is clearly suppressed, and the requirements for solid viscoelasticity It is understood that each provision of the constituent requirements of the present invention is reasonable and confirmed by experimental data.
In Comparative Example-1, since component (B) is not produced in the second step, W (A), W (B), etc. cannot be defined, and flexibility and transparency are inferior. In Comparative Example-2, the amounts of the component (A) and the component (B) are outside the scope of the present invention, the amount of the component (B) is less than the lower limit of the present invention, and G ′ (23) is from the definition of the present invention. Detachment, flexibility and transparency are inferior. In Comparative Example-3, the amount of component (A) and component (B) is outside the range of the present invention, and the amount of component (B) exceeds the upper limit of the range of the present invention. , Tα is too low (also clearly shown in FIG. 3), Δ (Tm−Tα) deviates from the definition of the present invention, and stickiness and heat resistance are reduced. In Comparative Example-4, [E] gap is too low, G ′ (23) falls outside the definition of the present invention, and flexibility and transparency are inferior. In Comparative Example-5, [E] gap is too high, By taking the separation structure, the transparency is remarkably deteriorated (FIG. 4 also shows that the Tg peak is not single and shows a phase separation structure), and the stickiness is also poor.
In Comparative Example-6, G ′ (23) deviates from the definition of the present invention, Tm (A) is too high,
Rigidity becomes too high, transparency and flexibility deteriorate, and in Comparative Example-7, the amount of component (A) and component (B) is outside the scope of the present invention, and the amount of component (B) is the amount of the present invention. Exceeding the upper limit of the range, Δ (Tm−Tα) deviates from the definition of the present invention, Tm (A) is too high, and deterioration in stickiness and decrease in heat resistance are observed. In Comparative Example-8, [E] Gap and Tm (A) are too high, and transparency and low-temperature moldability are deteriorated by taking a phase separation structure.
In Comparative Examples-9 to 11, an attempt was made to obtain a block copolymer similar to the Example of the present invention using a Ziegler-Natta catalyst, but in Comparative Example-9, Tm (A) and Mw ≦ 5000 is too high, and in Comparative Examples-10 and 11, Tm (A) is too high, and [η] cxs falls outside the definition of the present invention, both of which have poor transparency, lack of flexibility, stickiness and bleeding out. Is also significantly worse.
The polymer of each comparative example is inferior as a polymer material compared to the propylene-ethylene block copolymer of the present invention, which is generally superior in various properties such as transparency and flexibility, and the copolymer of the present invention. The outstanding features of
In addition, the necessity for the use of the metallocene catalyst in the present invention is confirmed from the comparison with Comparative Examples-9 to 11 of the copolymer produced by the Ziegler-Natta catalyst.

It is a graph which shows the elution amount curve and elution amount integration in Example-1. It is a graph which shows the solid viscoelasticity measurement in Example-1. It is a graph which shows the solid viscoelasticity measurement in the comparative example-3. It is a graph which shows the solid viscoelasticity measurement in the comparative example-5. It is the schematic which shows prescription | regulation of the baseline in the chromatogram of GPC measurement.

Claims (6)

Using a metallocene catalyst, a crystalline propylene-ethylene random copolymer component (A) having a melting peak temperature Tm (A) by a differential scanning calorimeter (DSC) of 105 to 145 ° C. in the first step (hereinafter, Low crystalline or amorphous propylene-ethylene random copolymer containing 30 to 70 wt% of component (A) and 6 to 15 wt% ethylene more than the ethylene content contained in component (A) in the second step Propylene-ethylene random obtained by sequentially polymerizing 70 to 30 wt% of component (B) (hereinafter referred to as component (B)) and satisfying the following conditions (i) to (iv) Block copolymer.
(I) In the temperature-loss tangent (tan δ) curve, it has a single peak below 0 ° C. (ii) In the temperature-storage elastic modulus (G ′) curve obtained by solid viscoelasticity measurement (DMA), The storage elastic modulus G ′ (23) [MPa] at 200 ° C. is 200 or less (iii) The temperature Tα at which G ′ becomes 2 MPa is in the range of 100 to 140 ° C. (iv) The differential scanning calorimeter (DSC) ) The difference (Δ (Tm−Tα)) between the melting peak temperatures Tm and Tα in the melting curve obtained by The propylene-ethylene random block copolymer according to claim 1, wherein the following condition (v) is satisfied.
(V) The weight average molecular weight Mw of the block copolymer obtained by gel permeation chromatography (GPC) measurement is in the range of 100,000 to 400,000, and the molecular weight W (M ≦ 5,000) is 0.8 wt% or less of the whole The propylene-ethylene random block copolymer according to claim 1 or 2, wherein the following condition (vi) is satisfied.
(Vi) 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 propylene-ethylene random block copolymer according to any one of claims 1 to 3, wherein the ethylene content in the component (A) is 1 to 10 wt%. In the sequential polymerization of the component (A) and the component (B) using the metallocene catalyst, the Tm (A) is controlled by the range of the ethylene content of the component (A), and the amount of the component (A) and the component (B) The ratio is controlled by the production amount in the first step and the second step, the ethylene content of the component (A) and the component (B) is controlled by the amount of ethylene supplied to propylene in the first step and the second step, and the component (A) The component (B) has a difference in ethylene content of not more than 15% by weight to give a single peak of the condition (i), G ′ of the condition (ii), Tα of the condition (iii) and the condition (iv) Δ (Tm−Tα) of the component (A) is controlled by the range of the ethylene content of the component (A), Mw of the block polymer of the condition (v) is controlled by the viscosity [η] of the component (A), and the condition (v) The component amount W (M ≦ 5,000) of the block polymer of It is controlled by the transfer time and the monomer gas management in the transfer process from the second process to the second process, and the intrinsic viscosity [η] cxs in the condition (vi) is controlled by the ratio of hydrogen supply to the monomer in the second process. The method for producing a propylene-ethylene random block copolymer according to any one of claims 1 to 3. The molded article which consists of a film, a sheet | seat, a laminated body, or a container shape | molded with the propylene-ethylene random block copolymer as described in any one of Claims 1-4.

Images