JP2006307072A - Water-cooled inflation molded polypropylene film and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene resin film having improved film blocking resistance, transparency, flexibility and impact resistance.
SOLUTION: Using a metallocene catalyst, 30 to 95 wt% of propylene-ethylene random copolymer component (A1) having propylene alone or ethylene content of 7 wt% or less in the first step, and from component (A1) in the second step. Is a propylene-ethylene block copolymer (A) obtained by sequential polymerization of 70 to 5 wt% of a propylene-ethylene random copolymer component (A2) containing 3 to 20 wt% of ethylene, and the MFR is In the temperature-loss tangent curve obtained by solid viscoelasticity measurement in the range of 1-20 g / 10 minutes, a tan δ curve has a single peak at 0 ° C. or less, and a water-cooled inflation is used. Polypropylene film formed by molding.
[Selection figure] None

Description

  The present invention relates to a water-cooled inflation-molded polypropylene film, and more specifically, water-cooled with little balance of transparency, heat resistance, and impact strength, excellent flexibility, good opening, blocking resistance, and low bleed-out. The present invention relates to an inflation-molded polypropylene-based film, and its preferred use.

Conventional technology

Polypropylene films are widely used as packaging films for food and general goods, taking advantage of their mechanical properties such as excellent rigidity and optical properties such as transparency and glossiness, and their excellent economics and moldability. Furthermore, the demand for film materials is increasing further due to its adaptability to environmental problems.
When used in these film applications, blocking, which causes the films to be in close contact with each other and is difficult to peel off, is a major problem that deteriorates the bag-making process and the opening during use. Various proposals have been made for this improvement. I came.
However, when a large amount of an antiblocking agent such as silica is added in order to improve the blocking resistance, there is a problem that the excellent transparency that is characteristic of the polypropylene film is impaired.

Therefore, various methods have been proposed to improve such problems in polypropylene. For example, a method using silica having different particle diameters has been proposed (Patent Document 1). Although blocking can be solved, scratches occur when the films are rubbed by silica having a large particle diameter, resulting in insufficient transparency. Also, a resin produced by a gas phase method has a molecular weight in the presence of a radical generator. A method aiming to improve degradation resistance and blocking resistance and transparency has also been proposed (Patent Document 2). Although this method has some effect, it is not sufficient. Furthermore, this method uses polypropylene to reduce molecular weight. A process with a radical generator, which causes problems such as deterioration of the end color of film-wrapped products and odor. It has caused come.
Although a water-cooled inflation film using a propylene resin having a narrow molecular weight distribution and a narrow crystallinity distribution has been proposed even without performing molecular weight degradation (Patent Document 3), the problem of the end face color and odor of the film is solved. There is a problem in film formation stability, particularly when the blow ratio is increased, bubble shake occurs, film formation stability is insufficient, and satisfactory results are not obtained with respect to film properties.

  In view of such various problems, a water-cooled inflation-molded polypropylene film having a good transparency composed of a resin composition of a specific crystalline polypropylene based on a metallocene catalyst and synthetic silica and a fatty acid amide has been proposed (Patent Document 4). ), This water-cooled inflation-molded polypropylene film is excellent in balance of transparency, slipperiness and blocking resistance, as well as scratch resistance and impact resistance. However, for applications that require strong impact resistance, such as food packaging used at relatively low temperatures, such as vegetable packaging, and heavy-weight packaging such as liquids, a film having further impact strength is desired.

On the other hand, with a specific polypropylene resin, studies to improve the flexibility (flexibility) and impact resistance of polypropylene films are also being conducted.
The so-called block type reactor TPO, which produces crystalline polypropylene in the first step and propylene-ethylene copolymer elastomer in the second step, has better heat resistance and productivity than the random copolymer type elastomer. It has excellent characteristics, and has advantageous properties such as stable product quality, lower production cost, and wide variation of the composition of elastomers compared to elastomers manufactured by mechanical mixing. Therefore, it is highly economical and has been widely used recently.
However, in many cases, the crystalline polypropylene produced in the first step and the propylene-ethylene copolymer elastomer produced in the second step are phase-separated, resulting in extremely poor transparency and flexibility. Since it has the disadvantage of being inferior, its use has been difficult in the field of films that require transparency.
Therefore, if a polypropylene-based elastomer or plastomer that is extremely excellent in transparency and flexibility is realized, it is recognized that it is very meaningful as a film material as a packaging material, and various improvement proposals have been made 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 in the second step than in the first step A method of continuously polymerizing relatively little propylene-ethylene copolymer elastomer using a Ziegler-Natta catalyst is disclosed (Patent Document 5). However, since Ziegler-Natta catalysts have multiple types of active sites, the produced propylene-ethylene copolymer has a wide crystallinity and molecular weight distribution, and produces many low molecular weight and low molecular weight components. Stickiness and bleed-out (exudation of low molecular weight components and additives) are strongly observed, and inherent disadvantages such as blocking and poor appearance are likely to occur.
For this reason, a technique of increasing the intrinsic viscosity of the elastomer, that is, the molecular weight, to some extent so as to suppress the generation of the low molecular weight component is disclosed (Patent Document 6). The effect is small, the transparency is not enough, and the improvement of stickiness and bleed-out is still insufficient. As a result, the use of organic peroxides in the granulation process presents many problems such as a significant deterioration in odor.
More recently, a block type reactor TPO using a metallocene catalyst has also been disclosed, but the transparency, flexibility and impact resistance of the polypropylene film are improved in a balanced manner to solve the blocking problem. The technique has not been seen yet.

JP-A-4-39343 JP-A-5-279522 JP-A-11-255825 JP2003-82180A (summary) Japanese Patent Laid-Open No. 63-159212 (Claims, lower right column on page 2) JP-A-9-324022 (summary)

  As outlined in the paragraphs 0002 to 0006 of the background art, an effective method for improving the blocking resistance of the film and improving the transparency, flexibility, impact resistance, etc. has not been developed. Many TPOs are inferior in transparency, and by using a polypropylene resin with improved transparency, a film having excellent transparency and flexibility can be formed, and its effective use is also desired. However, since the packaging film exhibits other problems such as stickiness and bleed out even if the transparency and flexibility are excellent, the present invention improves the blocking resistance of the film, and the transparency and flexibility and A block-type reactor that develops effective methods to improve impact resistance and can form films with excellent transparency and flexibility. Propylene is a TPO - that utilized effectively as a film material for ethylene block copolymer, it is an issue to be solved invention.

  The inventors of the present invention have previously had solid component viscoelastic characteristics, elution characteristics in temperature-elevated elution fractionation, etc., with specific component composition, molecular weight distribution, composition distribution, etc., by multistage polymerization using a metallocene catalyst. A series of research and development has been conducted on a propylene-ethylene block copolymer (hereinafter sometimes abbreviated as “block copolymer”), and an application has been filed as a prior invention (Japanese Patent Application No. 2003-371458 and others) ) When the polypropylene produced by the vapor phase process, which is the subject of the present invention, is used as a film, it is effective to improve the blocking resistance of the film and to improve the transparency, flexibility and impact resistance. As a film material for propylene-ethylene block copolymer, a block type reactor TPO In order to make effective use of such a prior invention, the propylene-ethylene block copolymer in the prior invention is used as a raw material to improve the blocking resistance of the film and make it transparent. We decided to seek a new method to improve the performance, flexibility and impact resistance.

  In order to find such a technique, the present inventors use a metallocene catalyst, and in the first step, more propylene-ethylene random copolymer component containing propylene alone or a small amount of ethylene in the second step than in the first step. In the propylene-ethylene block copolymer obtained by sequentially polymerizing propylene-ethylene random copolymer components containing ethylene, the component composition of each copolymer, ethylene content, crystallinity distribution and molecular weight distribution, Various considerations have been made on solid viscoelastic properties, elution characteristics in temperature-elevated elution fractionation methods, melt flow rates and melting peak temperatures measured by DSC, and various film forming methods. In the process of trials from various experiments under each condition, the above-mentioned problems of the present invention are solved. The present invention is created by effectively utilizing a water-cooled inflation method capable of forming a film having excellent balance of transparency, surface characteristics and heat resistance as a film forming method. It came to.

  Those basic requirements recognized as described above include, in the second step, a propylene-ethylene random copolymer component containing propylene alone or a small amount of ethylene in the first step using a metallocene catalyst. In the propylene-ethylene block copolymer obtained by sequentially polymerizing a propylene-ethylene random copolymer component containing more ethylene than in the first step, the component composition and ethylene content of each copolymer are specified, and such The copolymer is formed into a film by water-cooled inflation molding, and a tan δ curve is specified as the melt flow rate and solid viscoelastic properties of the propylene-ethylene block copolymer.

Specifically, in the first step, propylene alone or propylene-ethylene random copolymer component (A1) having an ethylene content of 7 wt% or less is 30 to 95 wt%, and in the second step, 3 to 20 wt% more than component (A1). 70 to 5 wt% of a propylene-ethylene random copolymer component (A2) containing a small amount of ethylene is sequentially polymerized, and the block copolymer has a melt flow rate (MFR) of 1 to 20 g / 10 due to moldability of water-cooled inflation. In the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA) for improving the transparency of the film, the tan δ curve has a single peak below 0 ° C. It is.
Such numerical definition is based on experimental verification and the like, and can be confirmed also by comparison with examples and comparative examples described later.

  In addition, incidentally, elution in a TREF elution curve obtained as a plot of molecular weight obtained by gel permeation chromatography (GPC) and elution amount (dWt% / dT) against temperature by temperature-temperature elution fractionation method (TREF) Characteristics, intrinsic viscosity [η] cxs measured in 135 ° C. decalin of 23 ° C. xylene-soluble component, and anti-blocking agent and its blending amount are also specified in order to enhance the blocking resistance of the film.

The present invention effectively utilizes the characteristics of excellent balance of transparency, gloss and heat resistance obtained by the water-cooled inflation method in the polypropylene film, and improves impact resistance to provide appropriate flexibility (flexibility). Propylene-ethylene block copolymer, which is a block type reactor TPO, that can suppress bleed out, blocking and odor, and can form a film with excellent transparency, flexibility and film opening. The effective use of the polymer as a film material has been realized. Such a polypropylene film is extremely excellent in transparency, has high heat resistance, and also has impact resistance and flexibility. Therefore, the polypropylene film is extremely suitable for use as a packaging material for foods and medical treatments that require a heat sterilization process. It can be used suitably.
Therefore, these features and the requirements of the configuration described in paragraph 0012 are not suggested or given by the prior art in the prior art.

  In the above, the background of the creation of the present invention and the configuration and characteristics of the invention have been described in general. If the overall configuration of the present invention is viewed here, the present invention comprises the following invention unit groups. Note that the invention described in [1] is a basic invention, and [2] the following invention adds an additional requirement to the basic invention or shows an embodiment.

[1] A water-cooled inflation molded polypropylene film formed by water-cooled inflation molding using a propylene-ethylene random block copolymer satisfying the following conditions (Ai) to (A-iii) as a raw material .
(Ai) 30 to 95 wt% of propylene-ethylene random copolymer component (A1) having propylene alone or ethylene content of 7 wt% or less in the first step using the metallocene catalyst, and component (A1) in the second step It is a propylene-ethylene block copolymer (A) obtained by successively polymerizing 70 to 5 wt% of a propylene-ethylene random copolymer component (A2) containing 3 to 20 wt% more ethylene than ( A-ii) Melt flow rate (MFR: 230 ° C. 2.16 kg) is in the range of 1 to 20 g / 10 minutes (A-iii) Temperature-loss tangent (tan δ) obtained by solid viscoelasticity measurement (DMA) In the curve, the tan δ curve has a single peak at 0 ° C. or lower. [2] The propylene-ethylene block copolymer (A) has the following conditions ( And satisfies the -iv), water-cooling inflation molding polypropylene-based film of [1].
(A-iv) The component amount W (Mw ≦ 5,000) of 5,000 or less in the molecular weight obtained by gel permeation chromatography (GPC) measurement is 0.8 wt% or less of the whole [3] Propylene -The water-cooled inflation-molded polypropylene film according to [1] or [2], wherein the ethylene block copolymer (A) satisfies the following conditions (Av) to (A-vi).
(Av) The component (A1) obtained in the first step is a propylene-ethylene random copolymer having an ethylene content in the range of 0.5 to 6 wt%, and the proportion of the block copolymer (A) in the whole Is in the range of 30 to 85 wt%, the component (A2) obtained in the second step is 6 to 18 wt% more ethylene content than (A1), and the proportion of the block copolymer (A) in the whole is 70 to (A-vi) Elution amount (dWt% / dT) with respect to temperature by temperature rising elution fractionation method (TREF) in a temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. ), The peak T (A1) observed on the high temperature side is in the range of 55 ° C. to 96 ° C., and the peak T (A2) observed on the low temperature side is below 45 ° C. Alternatively, the peak T (A2) is not observed, and the temperature T (A4) at which 99 wt% of the total propylene-ethylene block copolymer (A) elutes is 98 ° C. or lower. [4] Propylene-ethylene block copolymer The water-cooled inflation-molded polypropylene film according to any one of [1] to [3], wherein the coalescence (A) satisfies the following conditions (A-vii) to (A-iii):
(A-vii) The component (A1) obtained in the first step is a propylene-ethylene random copolymer having an ethylene content in the range of 1.5 to 6 wt%, and the ratio of the entire block copolymer (A) Is in the range of 30 to 70 wt%, the component (A2) obtained in the second step is 8 to 16 wt% more ethylene content than (A1), and the proportion of the block copolymer (A) in the whole is 70 to 70 wt%. Elution amount (dWt% / dT) with respect to temperature by temperature rising elution fractionation method (TREF) in a temperature range of −15 ° C. to 140 ° C. using (A-ix) o-dichlorobenzene solvent. ), The peak T (A1) observed on the high temperature side is in the range of 60 ° C. to 88 ° C., and the peak T (A2) observed on the low temperature side is 40 ° C. or higher. Or the peak T (A2) is not observed, and the temperature T (A4) at which 99 wt% of the total propylene-ethylene block copolymer (A) elutes is 90 ° C. or lower. [5] Propylene-ethylene block The water-cooled inflation molded polypropylene film according to any one of [1] to [4], wherein the copolymer satisfies the following condition (A-ix).
(A-ix) The intrinsic viscosity [η] cxs measured in decalin at 135 ° C. of the 23 ° C. xylene soluble component is in the range of 1 to 2 (dl / g) [6] Propylene-ethylene block copolymer An antiblocking agent having an average particle diameter of 1 to 7 μm and 0.01 to 1.0 part by weight and a fatty acid amide 0.01 to 1.0 part by weight are blended with 100 parts by weight of the union (A). The water-cooled inflation-molded polypropylene film according to any one of [1] to [5].
[7] The water-cooled inflation molded polypropylene film according to any one of [1] to [6], wherein the tensile elastic modulus is 400 MPa or less and the punching impact strength at 23 ° C. is 3000 J / mm or more.
[8] A polypropylene-based laminated film comprising at least one layer formed of the water-cooled inflation-molded polypropylene-based film according to any one of [1] to [7].
[9] A food packaging bag or a medical bag, which is made of the polypropylene film according to any one of [1] to [8] and is used after heat sterilization.

The water-cooled inflation-molded polypropylene film in the present invention has excellent balance of transparency, gloss, heat resistance, impact strength, etc. In addition, it has an appropriate flexibility (flexibility) and has good opening properties, It is a polypropylene film with low odor and particularly improved blocking properties and suppressed bleeding out.
The film of the present invention can be suitably used as a packaging material for foods because of its excellent transparency, flexibility, heat resistance, and economical efficiency.
In addition, the present invention can also be used effectively as a film material of a propylene-ethylene block copolymer, which is a block type reactor TPO, capable of forming a film having excellent transparency and flexibility. is there.

  In the following, embodiments of the present invention will be described in detail in order to explain the entire invention group of the present invention in detail.

1. Configuration of Propylene-Ethylene Block Copolymer (1) Basic Rules In the present invention, the propylene-ethylene block copolymer (A) used as a raw material for the water-cooled blown film is a metallocene catalyst in the first step. Propylene-ethylene random copolymer containing 30 to 95 wt% propylene-ethylene random copolymer component (A1) with propylene alone or ethylene content of 7 wt% or less, and 3 to 20 wt% more ethylene than the first step in the second step It is obtained by successively polymerizing 70 to 5 wt% of the combined component (A2).
Such a propylene-ethylene block copolymer (A) is commonly called a so-called block copolymer, but is in a blended state of the component (A1) and the component (A2), and both are polymerized. It is not something that is connected with.

(2) Component (A1) (2-1) Ethylene content E in component (A1) E (A1)
The component (A1) produced in the first step is a propylene homopolymer having a relatively high melting point and crystallinity, or propylene having an ethylene content of 7 wt% or less in order to suppress stickiness and develop heat resistance. -It must be an ethylene random copolymer. When the ethylene content exceeds 7 wt%, the melting point becomes too low and the heat resistance is deteriorated, so the ethylene content is 7 wt% or less, preferably 6 wt% or less.
The component (A1) exhibits improved flexibility, transparency and heat resistance even with a propylene homopolymer, but sufficient flexibility while maintaining transparency when the component (A1) is a propylene homopolymer. It is necessary to increase the proportion of the component (A2) described later in order to exhibit the above, and there is a concern that the heat resistance and remarkable deterioration such as stickiness and blocking may be caused.
On the other hand, when the component (A1) is a propylene-ethylene random copolymer, the heat resistance seems to deteriorate due to a decrease in the melting point of the component (A1) itself, but it is necessary for exhibiting sufficient flexibility. Since the amount of the component (A2) can be suppressed, the heat resistance of the block copolymer as a whole is rather improved, and stickiness and blocking are less deteriorated, which is preferable.
Furthermore, by reducing the melting point, a water-cooled inflation molded film having extremely excellent odor can be obtained by obtaining sufficient extrusion stability even if the molding temperature during water-cooled inflation molding is lowered.
From these viewpoints, the ethylene content in the component (A1) is preferably 0.5 wt% or more, more preferably 1.5 wt% or more.

(2-2) Proportion of component (A1) in block copolymer (A) If the proportion of component (A1) in propylene-ethylene block copolymer is too large, propylene-ethylene (A) block copolymer The effect of improving the flexibility, impact resistance and transparency of the coalescence cannot be sufficiently exhibited. Therefore, the proportion of the component (A1) is 95 wt% or less, preferably 85 wt% or less, more preferably 70 wt% or less.
On the other hand, if the proportion of the component (A1) becomes too small, the stickiness increases and the heat resistance is remarkably deteriorated. Therefore, the proportion of the component (A1) is 30 wt% or more, preferably 40 wt% or more.

(3) Regarding component (A2) (3-1) Ethylene content E (A2) in component (A2)
The propylene-ethylene random copolymer component (A2) produced in the second step is a component necessary for improving the flexibility, impact resistance and transparency of the propylene-ethylene block copolymer (A). .
Here, the component (A2) needs to have an ethylene content in a specific range in order to sufficiently exhibit the above effects. That is, in the block copolymer of the present invention, the lower the crystallinity of the component (A2) relative to the component (A1), the greater the flexibility improvement effect, and the crystallinity is the ethylene content in the propylene-ethylene random copolymer. Therefore, the ethylene content E (A2) in the component (A2) cannot be effective unless the ethylene content E (A1) in the component (A1) is 3 wt% or more, preferably 6 wt%. % Or more, more preferably 8 wt% or more, and more ethylene than component (A1).
Here, when the difference in ethylene content between the component (A1) and the component (A2) is defined as E (gap) (= E (A2) −E (A1)), E (gap) is 3 wt% or more, preferably 6 wt% % Or more, more preferably 8 wt% or more.
On the other hand, if the ethylene content is excessively increased to lower the crystallinity of the component (A2), the difference E (gap) between the ethylene content of the component (A1) and the component (A2) increases, and the phase is divided into a matrix and a domain. A separation structure is taken, and transparency is lowered. This is because polypropylene originally has low compatibility with polyethylene, and even in the propylene-ethylene random copolymer, although the ethylene content is different, the mutual compatibility decreases as the difference in ethylene content increases. The upper limit of E (gap) may be in a range where the peak of tan δ becomes single by solid viscoelasticity measurement described later in paragraph 0025. For that purpose, E (gap) is 20 wt% or less, preferably 18 wt%. % Or less, more preferably 16 wt% or less.

(3-2) The proportion of the component (A2) in the block copolymer (A) If the proportion of the component (A2) is too large, the stickiness increases, the blocking is deteriorated, and the heat resistance is significantly reduced. The ratio of the component (A2) needs to be suppressed to 70 wt% or less.
On the other hand, if the proportion of component (A2) becomes too small, the effect of improving flexibility and impact resistance cannot be obtained, so the proportion of (A2) needs to be 5 wt% or more, preferably 15 wt% or more. More preferably, it is 30 wt% or more.

(4) Melt flow rate (MFR) of block copolymer (A)
The MFR of the propylene-ethylene block copolymer (A) used for the polypropylene film of the present invention needs to be in the range of 1 to 20 g / 10 min.
That is, in order to achieve transparency and physical properties of the film which is the object of the present invention, it is necessary to take specific molding conditions. However, if MFR is too low in the molding conditions of the present invention, the surface of the film is sharked. Surface roughness called skin or melt fracture occurs and the transparency and appearance are significantly impaired. In addition, the motor load of the extruder increases and the resin itself cannot be extruded. On the other hand, if the MFR is too high, the bubble stability at the time of molding deteriorates, the width and thickness of the film fluctuate, and a product cannot be obtained.
Therefore, in the present invention, the MFR of the propylene-ethylene block copolymer (A) must be in the range of 1 to 20 g / 10 min, preferably 3 to 15 g / 10 min, more preferably 5 to 10 g / 10 min. Is preferable from the viewpoint of balance between molding stability, film appearance, and physical properties.
In addition, the melt flow rate (MFR) in this invention was measured on condition of test temperature: 230 degreeC Nominal load: 2.16kg Die shape: Diameter 2.095mm Length 8.00mm according to JISK7210A method condition M. Is.

(5) Specific by solid viscoelasticity (5-1) Specification by tan δ curve peak The propylene-ethylene block copolymer (A) used for the polypropylene film of the present invention is obtained by solid viscoelasticity measurement (DMA). In the resulting temperature-loss tangent (tan δ) curve, it is necessary that the tan δ curve has a single peak below 0 ° C.
When the component propylene-ethylene block copolymer (A) has a phase separation structure, the glass transition temperature of the amorphous part contained in the component (A1) and the glass transition temperature of the amorphous part contained in the component (A2) Since each is different, there are a plurality of peaks. In this case, there arises a problem that the transparency is remarkably deteriorated.
Whether or not the phase separation structure is taken can be determined in the tan δ curve in the measurement of solid viscoelasticity, and the avoidance of the phase separation structure that affects the transparency of the molded product has a single peak in the tan δ curve below 0 ° C. Is brought about by having.
In the present invention, it is necessary that the tan δ curve in the solid viscoelasticity measurement has a single peak in order to exhibit transparency.
In addition, the example of the peak of the tan-delta curve of this invention and the example of the tan-delta curve when it does not have a single peak for comparison are shown in FIG. 2 and FIG. It is shown.

(5-2) 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, and the loss tangent (= loss elastic modulus G ″ / storage elastic modulus G ′) defined by the ratio is plotted against the temperature. Then, a tan δ curve is obtained, and in the present invention, a sharp peak is shown in a temperature range of 0 ° C. or lower. In general, the peak of the tan δ curve at 0 ° C. or lower is for observing the glass transition of the amorphous part, and here, this peak temperature is defined as the glass transition temperature Tg (° C.).

(6) Specificity of each component (A1) and (A2) ethylene content E (A1) and E (A2) and each component amount W (A1) and W (A2) of component (A1) and (A2) Each ethylene content and component amount can be specified by the material balance at the time of polymerization (material balance), but in order to specify these more accurately, it is desirable to use the following analysis (fractionation method). .

(6-1) Identification of component amounts W (A1) and W (A2) by temperature-temperature elution fractionation method (TREF) 6-1-1. Temperature Elevated Elution Fractionation Method A technique for evaluating the crystallinity distribution of a propylene-ethylene random copolymer by temperature elevated elution fractionation method (TREF) is well known to those skilled in the art. Detailed measurement methods are shown.
G. Glockner, J. et al. Appl. Polym. Sci. : Appl. Po
lym. Symp. 45, 1-24 (1990)
L. Wild, Adv. Polym. Sci. 98, 1-47 (1990)
J. et al. B. P. Soares, A .; E. Hamielec, Polymer; 36,
8, 1639-1654 (1995)
The propylene-ethylene block copolymer (A) in the present invention has a large difference in crystallinity between the components (A1) and (A2), and each crystallinity is produced by using a metallocene catalyst. Since the distribution is narrow, there are very few intermediate components between the two, and both can be accurately separated by TREF.

In the TREF elution curve obtained as a plot of elution amount (dWt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using o-dichlorobenzene solvent, (A1) and (A2) show their elution peaks at the respective temperatures T (A1) and T (A2) due to the difference in crystallinity, and since the difference is sufficiently large, the intermediate temperature T (A3) (= {T Separation is possible in (A1) + T (A2)} / 2).
In addition, the lower limit of the TREF measurement temperature is −15 ° C. in the apparatus used for this measurement, but in the case where the crystallinity of the component (A2) is very low or an amorphous component, There may be no peak within the range (at this time, the concentration of the component (A2) dissolved in the solvent is detected at the lower limit of the measurement temperature (ie, −15 ° C.)). In this case, T (A2) is considered to exist below the lower limit of the measurement temperature, but the value cannot be measured. In such a case, T (A2) is the lower limit of the measurement temperature − It is defined as 15 ° C.
Here, if the integrated amount of the component eluted before T (A3) is defined as W (A2) wt%, and the integrated amount of the component eluted at T (A3) or higher is defined as W (A1) wt%, W (A2) Almost corresponds to the amount of the low-crystalline or amorphous component (A2), and the integrated amount W (A1) of the component eluted at T (A3) or higher is the component (A1) having a relatively high crystallinity. Almost corresponds to the amount of. In addition, the example of a TREF elution curve is illustrated by FIG. 1 as an example in superposition | polymerization manufacture example A-1.

6-1-2. TREF Measurement Method In the present invention, specifically, measurement is 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 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, a component of −15 ° C. o-dichlorobenzene (containing 0.5 mg / ml BHT), which is a solvent, flows through the column at a flow rate of 1 ml / min, and is dissolved in o-dichlorobenzene at −15 ° C. in the TREF column. Is eluted 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.

(6-2) Identification of ethylene content E (A1) and E (A2) in each component 6-2-1. Separation of components (A1) and (A2) Based on T (A3) determined by the previous TREF measurement, the components of soluble components in T (A3) (by temperature rising column fractionation using a preparative fractionator ( A2) and the insoluble component (A1) in T (A3) are fractionated, and the ethylene content of each component is determined by NMR.
The temperature rising column fractionation method is a measurement method as disclosed in, for example, Macromolecules 21 314-319 (1988). Specifically, the following method was used in the present invention.

6-2-2. Fractionation conditions A cylindrical column having a diameter of 50 mm and a height of 500 mm is filled with a glass bead carrier (80 to 100 mesh) and maintained at 140 ° C. Next, 200 ml of the o-dichlorobenzene solution (10 mg / ml) of the sample dissolved at 140 ° C. is introduced into the column. Thereafter, the temperature of the column is cooled to 0 ° C. at a temperature decreasing rate of 10 ° C./hour. After holding at 0 ° C. for 1 hour, the column temperature is heated to T (A3) at a heating rate of 10 ° C./hour and held for 1 hour. Note that the temperature control accuracy of the column through a series of operations is ± 1 ° C.
Next, while keeping the column temperature at T (A3), 800 ml of o-dichlorobenzene of T (A3) is flowed at a flow rate of 20 ml / min, so that T (A3) -soluble components present in the column can be 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 o-dichlorobenzene as a solvent at 140 ° C. is flowed at a flow rate of 20 ml / min. , T (A3) is eluted and recovered.
The polymer-containing solution obtained by fractionation is concentrated to 20 ml using an evaporator and then precipitated in 5 times the amount of methanol. The precipitated polymer is recovered by filtration and then dried overnight in a vacuum dryer.

6-2-3. ¹³ C-NMR by measuring the fractionated by components obtained ethylene content and (A1) (A2) an ethylene content of each was measured according to the following conditions by complete proton decoupling ^method, a 13 C-NMR spectrum Obtained by analysis.
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 number: 5,000 times or more The attribution of the spectrum may be performed with reference to, for example, Macromolecules 17 1950 (1984). The spectral attributions measured under the above conditions are shown in Table 1. In the table, symbols such as S _αα are in accordance with the notation of Carman et al. (Macromolecules 10 536 (1977)), P represents a methyl carbon, S represents a methylene carbon, and T represents a methine carbon.

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

In order to obtain an accurate ethylene content, it is necessary to include these peaks derived from heterogeneous bonds in the calculation, but it is difficult to completely separate and identify the peaks derived from heterogeneous bonds, and the amount of heterogeneous bonds is small. 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 performed using the following formula.
Ethylene content (% by weight) = (28 × X / 100) / {28 × X / 100 + 42 × (1−X / 100)} × 100 where X is the ethylene content in mol%.
Further, the ethylene content E (W) of the entire block copolymer is calculated from the ethylene contents E (A1), E (A2) and TREF of the components (A1) and (A2) measured above. The weight ratio W (A1) and W (A2) wt% is calculated by the following formula.
E (W) = {E (A1) × W (A1) + E (A2) × W (A2)} / 100 (wt%)

(6-3) Additional requirement of crystallinity distribution by TREF elution curve By using the TREF elution curve used for specifying the amount of each component, the propylene-ethylene block copolymer of the present invention has a crystallinity distribution. Additional features can be found in
6-3-1. Elution peak temperature T (A1)
The higher the elution peak temperature T (A1) of the component (A1) in the TREF elution curve, the higher the crystallinity of the component (A1). At this time, the higher the crystallinity of the component (A1), the higher the propylene-ethylene block content. The component (A2) necessary to improve the flexibility and transparency of the polymer (A) must be increased.
On the other hand, if the proportion of the component (A2) is too large, stickiness and heat resistance are deteriorated. Therefore, in order to improve the balance between flexibility and transparency, T (A1) should not be too high. Further, odor properties and the like tend to worsen with an increase in molding temperature, but it is also preferable in that stable plasticization can be obtained by reducing T (A1) even if the extrusion temperature is lowered.
In the present invention, component (A1) is propylene alone or a random copolymer of ethylene of 7 wt% or less, but T (A1) can be decreased by increasing the ethylene content. At this time, in order to exhibit sufficient balance between flexibility, transparency, and heat resistance, T (A1) is preferably 96 ° C. or lower, and most preferably in the range of 88 ° C. or lower.
On the other hand, when the peak temperature T (A1) is less than 55 ° C., the temperature at which the component (A1) crystals melt is low, and the block copolymer cannot exhibit sufficient heat resistance, resulting in poor blocking. Therefore, in the present invention, the peak temperature T (A1) is preferably 55 ° C. or higher, and more preferably 60 ° C. or higher.

6-3-2. Elution end temperature T (A4)
Even when T (A1) is low, transparency is deteriorated when the crystallinity distribution is present on the high crystal side. The cause is not clear, but if there is a crystalline distribution on the high crystal side, the density of the crystal structure increases and the density difference from the amorphous part increases, or the nucleation frequency decreases and the spherulite size increases. This is probably because of this.
Therefore, it is preferable to suppress the spread of crystallinity to the high temperature side in the TREF elution curve. The spread of crystallinity toward the high crystal side can be evaluated by TREF measurement, and the elution end temperature T (A4) of the entire propylene-ethylene block copolymer (A) with respect to the peak temperature T (A1) Considering the error in TREF measurement, it is difficult to define the temperature at which all elution occurs. Therefore, in the present invention, the temperature at which 99 wt% of the total elution is defined as the elution end temperature T (A4)) is preferably not high. If there is an elution component on the high temperature side, the crystallinity of the component increases. Therefore, as a preferable requirement of the present invention, T (A4) is 98 ° C. or less, preferably 90 ° C. or less.
Furthermore, the temperature difference ΔT (T (A4) −T (A1)) from the elution peak to the end is preferably 5 ° C. or less, more preferably 4 ° C. or less, and even more preferably 3 ° C. or less.

6-3-3. Elution peak temperature T (A2)
Since the flexibility and transparency of the propylene-ethylene block copolymer (A) cannot be ensured unless the crystallinity of the component (A2) is sufficiently reduced, T (A2) is preferably 45 ° C. or less. More preferably, it is 40 degrees C or less.

(7) About molecular weight (7-1) Definition of molecular weight The propylene-ethylene block copolymer (A) in the present invention has an additional characteristic 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 1023-1103 (1999).
Therefore, the block copolymer in the present invention has a low molecular weight component, and the amount of the component having a weight average molecular weight of 5,000 or less is 0.8 wt% or less, preferably 0.5 wt% or less.

(7-2) 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 calibration curve prepared in advance with standard polystyrene.
Standard polystyrenes used are the following brands manufactured by Tosoh Corporation. F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000
A calibration curve is prepared 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 values are 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.
Equipment: 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: o-dichlorobenzene Measurement temperature: 140 ° C.
Flow rate: 1.0 ml / min
Injection volume: 0.2ml
Sample Preparation Prepare a 1 mg / ml solution using o-dichlorobenzene (containing 0.5 mg / ml BHT) and dissolve it at 140 ° C. for about 1 hour.
The amount of the component having a molecular weight of 5,000 or less can also be determined from a plot of the elution ratio with respect to the molecular weight obtained by GPC measurement.

(8) Intrinsic viscosity [η] cxs
In the propylene-ethylene block copolymer (A), stickiness and bleed-out are particularly problematic because it is a component that is soluble in xylene at room temperature (CXS component), so that the intrinsic viscosity [η] (dl / g) The measurement of is preferably performed on the CXS component.
Here, the CXS component was prepared by dissolving a propylene-ethylene block copolymer in p-xylene at 130 ° C. to form a solution, and then leaving it at 25 ° C. for 12 hours. The precipitated polymer was separated by filtration, and p-xylene was removed from the filtrate. The intrinsic viscosity [η] cxs of the obtained CXS component can be measured using a Ubbelohde viscometer at a temperature of 135 ° C. using decalin as a solvent.
At this time, since the propylene-ethylene block copolymer of the present invention does not increase the generation of a component having a molecular weight of 5,000 or less that easily bleeds out, the conventional Ziegler-Natta catalyst has problems in production. Even if the intrinsic viscosity [η] cxs of the CXS component, which has a practical problem due to deterioration such as blocking, is in the region of 2 or less, it can be produced and used without causing any particular deterioration in physical properties.
The propylene-ethylene block copolymer which does not increase the component having a molecular weight of 5,000 or less while lowering the intrinsic viscosity of such a CXS component has characteristics in terms of physical properties such as high tensile elongation at break and high tensile strength at break. In addition, there is an effect that appearance defects called “butsu” and “fish eyes” are less likely to occur.

2. Propylene-ethylene block polymer production method (1) metallocene catalyst
The method for producing the propylene-ethylene block copolymer (A) of the present invention requires the use of a metallocene catalyst.
It is well known to those skilled in the art that stickiness and bleedout deteriorate when the molecular weight and crystallinity distribution are wide in the propylene-ethylene block copolymer, but also in the propylene-ethylene block copolymer used in the present invention, In order to suppress stickiness and bleed-out and to exhibit sufficient transparency in water-cooled inflation molding, it is necessary to polymerize using a metallocene catalyst that can narrow the molecular weight and crystallinity distribution. The fact that the propylene-ethylene block copolymer of the present invention cannot be obtained with a Natta-based catalyst is also apparent from the comparison of Examples and Comparative Examples described later.

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) and (b) and, if necessary, the component (c) used.
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) (B-1) 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.

(1-1) 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 hydrogen atoms. Atom, halogen atom, hydrocarbon group, alkoxy group, amino group, nitrogen-containing hydrocarbon group, phosphorus-containing hydrocarbon group or silicon-containing hydrocarbon group, X and Y are each independently, ie, the same or different. Also good. R ₁ and R _{2 each} represent hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, an oxygen-containing hydrocarbon group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon group. . a and b are the number of substituents. ]

Specifically, Q represents a divalent linking group that bridges two conjugated five-membered ring ligands, and has, for example, a divalent hydrocarbon group, a silylene group or 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 is a silylene group having a divalent hydrocarbon group and a hydrocarbon group as a substituent.
X and Y each represents a hydrogen atom, a halogen atom, a hydrocarbon group, an alkoxy group, an amino group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, or a silicon-containing hydrocarbon group. And chlorine, methyl, isobutyl, phenyl, dimethylamide, diethylamide group and the like. X and Y may be independent, that is, may be the same or different.
R ₁ and R ₂ represent hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, an oxygen-containing hydrocarbon group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon group. . Specific examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a phenyl group, a naphthyl group, a butenyl group, and a butadienyl group. In addition, halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing hydrocarbon group, boron-containing hydrocarbon group or phosphorus-containing hydrocarbon group include methoxy group, ethoxy group, phenoxy group, trimethylsilyl group. Typical examples include a group, a diethylamino group, a diphenylamino group, a pyrazolyl group, an indolyl group, a dimethylphosphino group, a diphenylphosphino group, a diphenylboron group, and a dimethoxyboron group. Among these, a hydrocarbon group having 1 to 20 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, and a butyl group are particularly preferable. By the way, adjacent R ₁ and R ₂ may combine to form a ring, on which a hydrocarbon group, halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing You may have a substituent which consists of a hydrocarbon group, a boron containing hydrocarbon group, or a phosphorus containing hydrocarbon group.
Me is a metal atom selected from titanium, zirconium and hafnium, preferably zirconium and hafnium.

  Among the components (a) described above, preferred for the production of the propylene polymer of the present invention is a substituted cyclopentadienyl group crosslinked with a silylene group, a germylene group or an alkylene group having a hydrocarbon substituent. A transition metal compound comprising a ligand having a substituted indenyl group, a substituted fluorenyl group, or a substituted azulenyl group, particularly preferably a 2,4-position crosslinked by a silylene group having a hydrocarbon substituent or a germylene group It is a transition metal compound comprising a ligand having a 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-propyl-4-phenanthrylindenyl) zirconium dichloride, dimethyl Silylenebis (2-methyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) azurenyl} zirconium dichloride, dimethylsilylenebi (2-Ethyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis (2-isopropyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis {2-ethyl-4- (2-fluorobiphenyl) azurenyl} zirconium Examples thereof include dichloride, dimethylsilylene bis {2-ethyl-4- (4-t-butyl-3-chlorophenyl) azurenyl} zirconium dichloride, and the like.
A compound in which the silylene group of the compound of these specific examples is replaced with a germylene group and zirconium is replaced with hafnium is also exemplified as a suitable compound.
In addition, since the catalyst component is not an important element of the present invention, it avoids complicated listing and is limited to a representative example, but it is obvious that the effective range of the present invention is not limited thereby. It is.

(1-2) 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, JP-A No. 2003-105015, and the like.
Here, as the particulate carrier used for the component (b-1) and the component (b-2), inorganic oxides such as silica, alumina, magnesia, silica alumina, silica magnesia, magnesium chloride, magnesium oxychloride, chloride Examples thereof include inorganic halides such as aluminum and lanthanum chloride, and porous organic carriers such as polypropylene, polyethylene, polystyrene, styrene divinyl benzene copolymer, and acrylic acid copolymer.

Further, as a non-limiting specific example of the component (b), as the component (b-1), a particulate carrier on which methylalumoxane, isobutylalumoxane, methylisobutylalumoxane, aluminum butylboronate tetraisobutyl and the like are supported 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., component (b-3), alumina, silica alumina, magnesium chloride, etc., 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.

(1-3) 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.

(1-4) 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 the contact can be made in the following order. Moreover, this contact may be performed not only at the time of catalyst preparation but also at the time of prepolymerization with olefin or at the time of polymerization of olefin.
1) Contact component (a) and component (b) 2) Add component (c) after contacting component (a) and component (b) 3) Contact component (a) and component (c) 4) Add component (b) after contact 4) Add component (a) after contacting component (b) and component (c) 5) Contact three components simultaneously

(1-5) Component Amounts The amounts of components (a), (b) and (c) used in the present invention are 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 (b). Therefore, the amount of the component (c) to the 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.

(1-6) Prepolymerization It is preferable that the catalyst of the present invention is subjected to a prepolymerization treatment in which a small amount of the olefin is brought into contact with the catalyst 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, but may be dried if necessary.
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.

(2) Production method When the component propylene-ethylene block copolymer (A) of the present invention is produced, the crystalline propylene-ethylene random copolymer component (A1) and the low crystalline or amorphous propylene-ethylene are used. It is necessary to sequentially polymerize the random copolymer component (A2).
When the propylene-ethylene block copolymer is a random copolymer obtained by simply copolymerizing ethylene with propylene, if the ethylene content is low, the flexibility, impact resistance and transparency are not sufficient, and these properties are improved. Therefore, when the ethylene content is increased, the heat resistance is extremely deteriorated and the production becomes difficult, and it is difficult to satisfy all the required qualities.
Therefore, in the present invention, the propylene-ethylene block copolymer is a block copolymer obtained by sequentially polymerizing components having different ethylene contents in the first step and the second step. Necessary to balance.
Further, in the present invention, since a copolymer having a low molecular weight and easily sticking alone may be used as the component (A2), in order to prevent problems such as adhesion to the reactor, the component (A1) is polymerized. It is desirable to use a method of polymerizing component (A2).
(2-1) Sequential Polymerization When the propylene-ethylene block polymer (A) of the present invention is produced, a crystalline propylene-ethylene random copolymer component (A1) and a low crystalline or amorphous propylene-ethylene are used. It is necessary to sequentially polymerize the random copolymer component (A2) for the reasons described above.
When performing sequential polymerization, either a batch method or a continuous method can be used, but it is generally desirable to use a continuous method from the viewpoint of productivity.
In the case of a batch method, it is possible to polymerize component (A1) and component (A2) 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 the continuous method, it is necessary to use a production facility in which two or more reactors are connected in series because it is necessary to individually polymerize the component (A1) and the component (A2). A plurality of reactors may be connected in series and / or in parallel for each of component (A1) and component (A2).

(2-2) Polymerization process As the polymerization process (polymerization method), an arbitrary polymerization method such as a slurry method, a bulk method, or a gas phase method can be used. Although it is possible to use supercritical conditions as intermediate conditions between the bulk method and the gas phase method, they are substantially the same as the gas phase method, and are therefore included in the gas phase method without any particular distinction.
Since the low crystalline or amorphous propylene-ethylene random copolymer component (A2) is easily soluble in organic solvents such as hydrocarbons and liquefied propylene, it is desirable to use a gas phase method for the production of the component (A2).
Any process may be used for the production of the crystalline propylene-ethylene random copolymer component (A1), but in the case of producing the component (A1) having a relatively low crystallinity, adhesion, etc. In order to avoid this problem, it is desirable to use a gas phase method.
Therefore, using a continuous method, first, the crystalline propylene-ethylene random copolymer component (A1) is polymerized by a bulk method or a gas phase method, and subsequently a low crystalline or amorphous propylene-ethylene random copolymer elastomer. Most preferably, component (A2) is polymerized by a gas phase process.

(2-3) Other polymerization conditions The polymerization temperature can be used without any particular problem as long as it is within a commonly used temperature range. Specifically, a range of 0 ° C. to 200 ° C., more preferably 40 ° C. to 100 ° C. can be used.
Although the polymerization pressure varies depending on the process to be selected, it can be used without any problem as long as it is in a pressure range usually used. Specifically, a range of greater than 0 to 200 MPa, more preferably 0.1 MPa to 50 MPa can be used. At this time, an inert gas such as nitrogen can be coexisted.
When the sequential polymerization of the component (A1) in the first step and the component (A2) in the second step is performed, it is desirable to add a polymerization inhibitor into the system in the second step. In the case of producing a propylene-ethylene block copolymer, if a polymerization inhibitor is added to a reactor that performs ethylene-propylene random copolymerization in the second step, the particle properties (fluidity, etc.) of the resulting powder, gel, etc. Product quality can be improved. Various technical studies have been made on this 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.

3. Method for Controlling Components of Propylene-Ethylene Block Copolymer Each element of propylene-ethylene block copolymer (A) used in the polypropylene film of the present invention is controlled as follows, and the propylene-ethylene block of the present invention is controlled. It can manufacture so that the structural requirements required for a copolymer (A) may be satisfy | filled.

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

(2) Component (A2) For the low crystalline or amorphous propylene-ethylene random copolymer component (A2), it is necessary to control the ethylene content E (A2), T (A2), and [η] cxs. is there.
In the present invention, in order to control E (A2) within a predetermined range, the ratio of ethylene supply to propylene in the second step may be controlled in the same manner as E (A1).
For example, when E (A2) is controlled to 5 to 20 wt%, the supply weight ratio of ethylene to propylene may be in the range of 0.01 to 5, preferably in the range of 0.05 to 2. At this time, although the crystallinity distribution of the component (A2) is slightly increased with the increase of the ethylene content, T (A2) is decreased with the increase of E (A2) like the component (A1).
Therefore, in order for T (A2) to satisfy the scope of the present invention, the relationship between E (A2) and T (A2) is grasped, and E (A2) is controlled to be within a predetermined range. Good. Note that [η] cxs is described in paragraph 0067.

(3) About W (A1) and W (A2) The amount W (A1) of component (A1) and the amount W (A2) of component (A2) are the production amounts of the first step for producing component (A1). It can be controlled by changing the ratio of the production amount of the component (A2). For example, in order to increase W (A1) and reduce W (A2), the production amount of the second step may be reduced while maintaining the production amount of the first step, which shortens the residence time of the second step. It can be easily controlled by reducing the polymerization pressure or polymerization temperature or increasing the amount of the polymerization inhibitor. The reverse is also true.
When actually setting the conditions, it is necessary to consider the activity decay. That is, in the range of the ethylene content E (A1) and E (A2) carried out in the present invention, generally, the polymerization activity increases when the ratio of ethylene supply to propylene is increased in order to increase the ethylene content. 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, the production amount W (A1) is lowered in the first step, and the polymerization is performed as necessary. Lower the temperature and / or shorten the polymerization time (residence time), or increase the ethylene content E (A2) in the second step, increase the production W (A2), and raise the polymerization temperature as necessary And / or conditions may be set in such a way as to increase the polymerization time (residence time).

(4) Glass transition temperature Tg In the propylene-ethylene block copolymer (A) used in the present invention, the glass transition temperature Tg described in paragraph 0025 needs to have a single peak. In order for Tg to have a single peak, the difference [E] gap or E (A2) between the ethylene content E (A1) in component (A1) and the ethylene content E (A2) in component (A2) ) -E (A1) may be 20 wt% or less, preferably 18 wt%, more preferably 16 wt% or less, and E (gap) may be reduced to a range where Tg becomes a single peak in actual measurement.
Depending on the ethylene content E (A1) of the crystalline copolymer component (A1), the ethylene content E (A2) of the low crystalline or non-crystalline copolymer component (A2) is within an appropriate range. By setting the supply weight ratio of ethylene to propylene during the polymerization of component (A2), it is possible to obtain a polymer having a predetermined [E] gap.
Moreover, Tg of the block copolymer (A) which does not take a phase-separation structure like this invention is ethylene content E (A1) in a component (A1), and ethylene content E (A2) in a component (A2). ) And the amount ratio of both components. In the present invention, the amount of the component (A2) is 5 to 70 wt%, but in this range, Tg is more strongly affected by the ethylene content E (A2) in the component (A2).
That is, Tg reflects the glass transition of the amorphous part. In the block copolymer (A) of the present invention, the component (A1) has crystallinity and relatively few amorphous parts. This is because (A2) is low crystalline or amorphous and most of it is an amorphous part.
Therefore, the value of Tg is controlled approximately by E (A2), and the control method of E (A2) is as described above in paragraph 0060.

(5) Melt flow rate (MFR) In the propylene-ethylene block copolymer (A) of the present invention, a crystalline copolymer component (A1) and a low crystallinity or amorphous property are maintained in order to maintain transparency. It is essential that the copolymer elastomer component (A2) is compatible, so that the viscosity [η] A1 of the component (A1), the viscosity [η] A2 of the component (A2), propylene-ethylene block copolymer An apparent viscosity mixing rule is generally established between the total viscosity [η] W of the combined (A). That is,
Log [η] W = {W (A1) × Log [η] A1 + W (A2) × Log [η] A2} / 100
Is generally established. Generally, since there is a certain correlation between MFR and [η], from the viewpoint of flexibility and heat resistance, [η] A2, W (A1), and W (A2) are set first. By changing [η] A1 according to the above equation, the MFR can be freely controlled.

(6) About T (A4) T (A4) is an index indicating the crystallinity distribution, and the narrower the crystallinity distribution of the component (A1) is, the closer T (A4) is to T (A1) (lower). ), Controlling T (A4) to be low is nothing but controlling the crystallinity distribution of the component (A1) and the component (A2) to be narrow.
In general, by using a metallocene catalyst, a polymer having a narrower crystallinity distribution can be obtained than when using a Ziegler-Natta catalyst. It is not necessary and sufficient to use a metallocene catalyst in order to narrow the sex distribution.
In order to adjust the final propylene-ethylene block copolymer (A) to those having desirable physical properties, the component (A1) and the component (A2) must have different specific polymer compositions. That is, in the first step and the second step, it is necessary to keep the polymerization conditions corresponding to the respective polymer compositions, particularly the monomer gas composition, at different specific values. Therefore, when the crystallinity distribution of the component (A2) is wide in the adopted process, the transfer step is adjusted so that the specific monomer gas mixture corresponding to the first step is not brought into the second step from the first step. It is necessary to devise such as. Specifically, the crystallinity distribution of the component (A2) can be narrowed by increasing the purge amount in the transfer step, or by diluting or substituting with an inert gas such as nitrogen. That is, T (A4) can be controlled to be low by adjusting the transfer process.

(7) About W (Mw ≦ 5,000) In general, a polymer having a narrower molecular weight distribution than that of a Ziegler-Natta catalyst can be obtained by using a metallocene catalyst. 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 replaced with an inert gas such as nitrogen in the transfer step. By completely replacing it, W (Mw ≦ 5,000) can be controlled to be small independently of the polymerization conditions.

(8) Intrinsic Viscosity For [η] cxs, since the propylene-ethylene block copolymer (A) of the present invention uses a metallocene catalyst, the component (A1) contains almost no CXS component. It can be controlled by changing the molecular weight of the component (A2).
Therefore, 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, a metallocene catalyst tends to have a lower molecular weight of the polymer as the polymerization temperature is higher. Therefore, [η] cxs can be controlled by changing the polymerization temperature. [Η] cxs can also be controlled by combining both the hydrogen supply ratio and the polymerization temperature.

4). Specific compounding agent (1) Anti-blocking agent In the water-cooled inflation molded film according to the present invention, an anti-blocking agent is preferably added to prevent blocking.
The antiblocking agent used in the polypropylene resin composition of the present invention has an average particle diameter of 1 to 7 μm, preferably 1 to 5 μm, and more preferably 1 to 4 μm. If the average particle size is less than 1 μm, the slipperiness and openability of the resulting film are inferior. On the other hand, if it exceeds 7 μm, the transparency and scratching properties deteriorate, which is not preferable. Here, the average particle diameter is a value obtained by Coulter counter measurement.

Specific examples of the antiblocking agent include, for example, inorganic or synthetic silica (silicon dioxide), magnesium silicate, aluminosilicate, talc, zeolite, aluminum borate, calcium carbonate, calcium sulfate, barium sulfate, calcium phosphate. Etc. are used.
As the organic system, polymethyl methacrylate, polymethylsilyltosesquioxane (silicone), polyamide, polytetrafluoroethylene, epoxy resin, polyester resin, benzoguanamine / formaldehyde (urea resin), phenol resin, and the like can be used.
In particular, synthetic silica and polymethyl methacrylate are preferable from the balance of dispersibility, transparency, blocking resistance, and scratch resistance.

Anti-blocking agents may be surface-treated, and as surface treating agents, surfactants, metal soaps, acrylic acids, oxalic acid, citric acid, tartaric acid and other organic acids, higher alcohols, esters, silicones, Condensed phosphates such as fluorine resin, silane coupling agent, sodium hexametaphosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium trimetaphosphate, etc. can be used. is there. The treatment method is not particularly limited, and a known method such as surface spraying or immersion can be employed.
The anti-blocking agent may have any shape, and can be any shape such as a spherical shape, a square shape, a columnar shape, a needle shape, a plate shape, and an indefinite shape.
These anti-blocking agents can be used singly or in combination of two or more in a range that does not impair the effects of this object.
The compounding amount of the antiblocking agent is 0.01 to 1.0 part by weight, preferably 0.1 to 0.7 part by weight, more preferably 0 to 100 parts by weight of the propylene-ethylene block copolymer of the present invention. .2 to 0.5 parts by weight. When the blending amount is less than the above range, the anti-blocking property, slipping property and opening property of the film are inferior. When the above range is exceeded, the transparency of the film is impaired.

(2) Fatty acid amide In the water-cooled inflation molded film according to the present invention, a fatty acid amide is preferably added to improve slipperiness.
Examples of fatty acid amides include monoamides, substituted amides, bisamides, and the like, which can be used alone or in combination of two or more.

Specific examples of monoamides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide as saturated fatty acid monoamides. Examples of the unsaturated fatty acid monoamide include oleic acid amide, erucic acid amide, and ricinoleic acid amide. Specific examples of substituted amides include N-stearyl stearic acid amide, N-oleyl oleic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, N-oleyl palmitic acid amide Etc.
Specific examples of bisamides include, as saturated fatty acid bisamides, methylene bis stearic acid amide, ethylene biscapric acid amide, ethylene bis lauric acid amide, ethylene bis stearic acid amide, ethylene bisisostearic acid amide, ethylene bishydroxystearic acid amide, Ethylene bis behenic acid amide, hexamethylene bis stearic acid amide, hexamethylene bis behenic acid amide, hexamethylene bishydroxy stearic acid amide, N, N'-distearyl adipic acid amide, N, N'-distearyl Sepacic acid amide etc. are mentioned.
Examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sepacic acid amide and the like.
Examples of the aromatic bisamide include m-xylylene bis stearic acid amide and N, N′-distearylisophthalic acid amide.
In particular, among the above fatty acid amides, oleic acid amide, erucic acid amide, and behenic acid amide are preferably used.
The blending amount of the fatty acid amide is 0.01 to 1.0 part by weight, preferably 0.05 to 0.7 part by weight, more preferably 100 parts by weight of the propylene-ethylene block copolymer of the present invention. 0.1 to 0.4 parts by weight. If it is less than the said range, opening property and slipperiness will be inferior. If the above range is exceeded, the fatty acid amide will be excessively raised and the transparency will deteriorate.

5. Additional ingredients (additives)
(1) Additive In the propylene-ethylene block copolymer of the present invention, an additional component is used as an optional component in order to enhance properties such as transparency and to add other properties such as oxidation resistance. Further, it can be blended within a range that does not significantly impair the effects of the present invention.
As this additional component, a nucleating agent, an antioxidant, a neutralizing agent, a light stabilizer, an ultraviolet absorber, an antistatic agent, a metal deactivator, a peroxide used as a conventionally known compounding agent for polyolefin resin Various additives such as fillers, antibacterial and antifungal agents, and fluorescent whitening agents can be added. The amount of these additives is 0.0001 to 3 parts by weight, preferably 0.001 to 1 part by weight, based on 100 parts by weight of the propylene-ethylene block copolymer of the present invention.
Furthermore, an elastomer can be mix | blended as a component which provides a softness | flexibility within the range which does not impair the effect of this invention remarkably. The blending amount of the elastomer is 1 to 30 parts by weight, preferably 5 to 20 parts by weight with respect to 100 parts by weight of the propylene-ethylene block copolymer of the present invention.

(2) Specific examples of additives Specific examples of the nucleating agent include sodium 2,2-methylene-bis (4,6-di-t-butylphenyl) phosphate, talc, 1,3,2,4-di ( sorbitol compounds such as p-methylbenzylidene) sorbitol, aluminum hydroxy-di (t-butylbenzoate), 2,2-methylene-bis (4,6-di-t-butylphenyl) phosphoric acid and 8 to 20 carbon atoms Aliphatic monocarboxylic acid lithium salt mixture (trade name NA21 manufactured by Asahi Denka Co., Ltd.), polyethylene resin and the like can be mentioned.
As a polyethylene-type resin, a density is 0.91-0.98 g / cm < ³ >, Preferably, it is 0.94-0.97 g / 10 cm < ³ >. If the density is outside this range, the effect of improving transparency cannot be obtained. The polyethylene resin has a 190 ° C. melt flow rate (MFR) of 5 g / 10 min or more, preferably 7 to 500 g / 10 min, and more preferably 10 to 100 g / 10 min. When the MFR is less than 5 g / 10 min, the dispersion diameter of the polyethylene resin is not sufficiently reduced, and the dispersed particles are reflected as irregularities on the film surface, leading to deterioration of transparency. In order to finely disperse the polyethylene resin, the MFR of the polyethylene resin is preferably larger than the MFR of the propylene-ethylene block copolymer.
The production of the polyethylene resin used in the present invention is not particularly limited with respect to the polymerization method and catalyst as long as a polymer having the desired physical properties can be produced, but a polyethylene resin obtained by an intermediate pressure process is preferred. . Among them, high density polyethylene is preferable.
For catalysts, Ziegler type catalysts (ie based on a combination of supported or unsupported halogen-containing titanium compounds and organoaluminum compounds), Kaminsky type catalysts (ie supported or unsupported metallocene compounds and organoaluminum compounds, in particular alumoxanes). Based on the combination).
There is no restriction | limiting about the shape of a polyethylene-type resin, A pellet form may be sufficient and a powder form may be sufficient.

Specific examples of the phenolic antioxidant as the antioxidant 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-t-butyl-4-hydroxybenzyl) benzene, 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspir [5,5] undecane, etc. 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid.
Specific examples of phosphorus antioxidants include tris (mixed, mono and 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, bis (2, 4-di-t-butylphenyl) pentaerythritol-di-phosphite, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,4-di-t -Butyl-5-methylphenyl) -4,4'-biphenylenediphosphonite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di- Or the like can be mentioned Sufaito.
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 the hindered amine stabilizer 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 , 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}] and the like.

In the present invention, an elastomer means a soft polymer material, and generally has a density of 0.90 g / cm ³ or less, preferably in the range of 0.86 to 0.90 g / cm ³ , and 2.16 Kg at 190 ° C. It is preferable that the melt flow rate (MFR) under load is in the range of 0.01 to 100 g / 10 minutes, preferably 0.05 to 50 g / 10 minutes. The elastomer has a crystallinity of less than 30% as measured by an X-ray diffraction method, or is amorphous.

Specific examples include propylene-based elastomers and ethylene-based elastomers. As the propylene-based elastomer, a copolymer elastomer of propylene and an α-olefin having 4 to 20 carbon atoms is used. The content of units derived from propylene is 5 to 95 mol%, preferably 20 to 92 mol%, more preferably 50 to 90 mol%, and the content of units derived from an α-olefin having 4 to 20 carbon atoms is 5 to 95 mol%, preferably 8 to 80 mol%, more preferably 10 to 50 mol%. As the ethylene elastomer, a copolymer elastomer of ethylene and an α-olefin having 3 to 20 carbon atoms is used. The content of units derived from ethylene is 5 to 95 mol%, preferably 20 to 92 mol%, more preferably 50 to 90 mol%, and the content of units derived from an α-olefin having 3 to 20 carbon atoms is 5 to 95 mol%, preferably 8 to 80 mol%, more preferably 10 to 50 mol%.
Examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and mixtures thereof. be able to. Among these, an α-olefin having 3 to 10 carbon atoms is preferable.
Further, in the present invention, in addition to propylene or ethylene and α-olefin, in addition to the component units derived from α-olefin, such as component units derived from vinyl compounds and diene compounds, as long as the characteristics are not lost. Of component units. Such component units include 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene. Such chain non-conjugated dienes, cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6 -Cyclic non-conjugated dienes such as chloromethyl-5-propenyl-2-norbornene, diene compounds such as 2,3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, or styrene or vinyl acetate And so on.

(2) Addition method These additional components can be directly added to each component of the present invention obtained by polymerization and used after melt-kneading, or may be added during melt-kneading. Furthermore, it can be added directly after melt-kneading, or can be added as a masterbatch 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 an antioxidant and a neutralizing agent are blended, mixed, melted and kneaded, and then molded into a product for use. 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 mixing, melting, and kneading, any conventionally known method can be used. Usually, a Henschel mixer, a super mixer, a V blender, a tumbler mixer, a ribbon blender, a Banbury mixer, a kneader blender, a single or twin screw kneading extruder. Can be implemented. Among these, it is preferable to perform mixing or melt-kneading with a uniaxial or biaxial kneading extruder.

6). Water-cooled inflation film (1) Water-cooled inflation The water-cooled inflation-molded polypropylene film of the present invention refers to a polypropylene film obtained by a water-cooled inflation molding method. The raw material is melted by an extruder and the molten resin is extruded into a tube shape through an annular die. It is a method of cooling with water confined inside, water cooling using a sizing ring or a water-cooling ring of water tank type, etc., cooling and solidifying, folding it with a pinch roll through a guide plate, and taking it out with a take-up machine.
Any known type of molding machine, extruder, die, water-cooled ring, guide plate, pinch roll, and film take-up machine that can be used in this molding method can be used. What can take a molding condition is suitable.

(2) Molding apparatus and molding method (2-1) Extruder Although various known extruders can be used as the extruder, in order to keep the resin temperature low and obtain stable discharge, a single-screw extruder Is preferably used. As the screw shape used for a single screw extruder, the type used for normal polyolefin extrusion can be widely used, but in order to stabilize plasticization, unmelted such as barrier type screw and mudock type mixing. It is preferable that the shape is difficult to produce. Further, even if the set temperature is low, there is a concern that if the heat generated by shearing is too great, the odor property may be deteriorated. Therefore, the groove depth of the metering part is preferably 1 mm or more, and preferably about 2 mm. It is. The compression rate expressed as the ratio of the groove depth between the feed portion and the metering portion is preferably about 1.2 to 4. Further, in order to suppress heat generation, it is preferable to use a grooved barrel having a groove in a feed portion where an increase in discharge amount per rotation speed can be obtained.

(2-2) Die Various die dies used for inflation molding can be used as the die. However, it is preferable to use a spiral mandrel die with less weld generation and excellent thickness uniformity.

(2-3) Molding temperature Although it does not specifically limit as a temperature which shape | molds the water-cooled inflation molding method film in this invention, It is more than melting peak temperature obtained by DSC measurement of a propylene-ethylene block copolymer, 270 It is preferable to take a range of less than ° C.
Usually, a polypropylene resin has a higher melting point than a polyethylene resin and is molded at a relatively high temperature. On the other hand, when the molding temperature is high, thermal deterioration of the polymer and additives and volatilization of low molecular weight components such as oligomers are promoted, and the odor is deteriorated.
In the present invention, by using a specific propylene-ethylene block copolymer, a stable extrusion can be obtained even when the molding temperature is lowered, so that the odor is remarkably improved. When the extrusion temperature is 270 ° C. or higher, the odor is deteriorated even if a raw material having a low molecular weight component or oligomer is used, so that it is formed to obtain a film having a low odor which is one of the objects of the present invention. The temperature is preferably less than 270 ° C. More preferably, it is the range of less than 250 degreeC, More preferably, it is less than 230 degreeC.
On the other hand, at temperatures below the melting point of the propylene-ethylene block copolymer (A), it is not possible to sufficiently plasticize and stable extrusion is impossible. Therefore, according to DSC measurement of the propylene-ethylene block copolymer (A). It is necessary to take a molding temperature higher than the melting peak temperature obtained.
The molding temperature in the present invention represents the set temperature in the cylinder portion excluding the feed portion of the extruder and in each area from the extruder to the die outlet.

(2-4) Lip width In the above temperature range, the problem when extruding a resin at a low temperature is the occurrence of film surface roughness called shark skin or melt fracture due to an increase in viscosity, and the anisotropic nature of the film. This is a decrease in the longitudinal tear strength and impact resistance due to the improvement of the properties.
That is, if the lip width is too narrow, surface roughness called shark skin or melt fracture occurs and the film appearance is remarkably impaired. In order to suppress these appearance defects, measures such as increasing the molding temperature and MFR to reduce the viscosity of the molten resin flowing through the die are usually taken, but the molding temperature should be in the above range from the viewpoint of odor. Is necessary, and the MFR needs to be within the above-described range, so that the lip width is preferably 0.5 mm or more.
On the other hand, if the lip width is too wide, the longitudinal orientation applied to the film becomes tight, the tear strength in the longitudinal direction is lowered, and the impact resistance is deteriorated accordingly. The film according to the present invention has improved longitudinal tear strength and impact resistance even when the width is 2 mm or more, but the lip width is 2 mm or less in order to obtain a film with a better balance and high commercial value. Is preferred. A more preferable lip width is 0.7 mm or more and 1.5 mm or less.

(2-5) Cooling ring Although the cooling ring is very important for cooling and solidifying the film, a well-known cooling ring for water-cooled inflation molding that is usually used in the present invention can be widely used. . Among these cooling rings, a water tank type water cooling ring can be used particularly suitably, and a film having a high commercial value with a better balance of transparency and impact strength can be obtained.

(2-6) Film-forming speed The forming (film-forming) speed is determined by the film thickness and width and the amount of extrusion, and can be adjusted within a range in which film-forming stability can be maintained. Generally, in water-cooled inflation molding, it is 1 to 150 m / min, preferably 5 to 100 m / min, more preferably 10 to 50 m / min.

(3) Film (3-1) Thickness The thickness of the water-cooled inflation molded polypropylene film in the present invention varies depending on the application and is not particularly limited, but is within the range of 10 to 500 μm, more preferably 15 to 400 μm. If it is, since the film excellent in transparency can be shape | molded stably, it is preferable.

(3-2) Post-treatment As other items, the polypropylene film obtained in the present invention can be subjected to a surface treatment usually employed industrially. Examples of general surface treatment methods include various treatment methods such as a corona discharge treatment method, an ozone treatment method, a flame treatment method, and a low-temperature plasma treatment method. Of these, the corona discharge treatment method is the most common and preferred.

(3-3) Layer structure The film can be used not only in a single layer but also in a laminated film by a coextrusion method. In the case of a laminated film by a coextrusion method, the polypropylene film of the present invention can be used in any layer as long as it contains at least one layer. Specific examples include the use of one layer of a two-layer film, an intermediate layer of a three-layer film, one surface layer of a three-layer film, and both surface layers. When using the laminated film by the co-extrusion method, the thickness of the film layer of the propylene-ethylene block copolymer of the present invention is in the range of 10% to 90% of the whole laminated film with respect to the whole film thickness. Is done.
Moreover, you may use for the composite film formed by laminating | stacking (laminate) various base materials further to the single layer film and laminated | multilayer film in this invention. Examples of the substrate to be laminated include nylon film, polyester film, polystyrene film, polypropylene film, polyethylene film, ethylene / vinyl alcohol copolymer film, aluminum foil, and paper. When the substrate is stretchable, it may be stretched uniaxially or biaxially. The biaxially stretched nylon film, the biaxially stretched polyester film, and the biaxially stretched polypropylene film may be subjected to surface treatment such as metal deposition such as aluminum, silica, and alumina, or polyvinylidene chloride coating.
Examples of the method for laminating the base film include a dry laminating method, a wet laminating method, a non-sol laminating method, and an extrusion laminating method. Among these, the dry laminating method is preferable from the viewpoint of excellent adhesive strength.
In the case of laminating with a base film, the surface of the treatment layer is surface-treated in advance. Examples of the surface treatment method include various treatment methods such as a corona discharge treatment method, an ozone treatment method, a flame treatment method, and a low temperature plasma treatment method as described above. Of these, the corona discharge treatment method is the most common and preferred. When laminating, after performing such surface treatment, a dry laminating adhesive, such as a polyether polyurethane adhesive, a polyester polyurethane adhesive, or the like is applied to the surface of the treatment layer, and then a base film is laminated.

(4) Film properties (4-1) Transparency In the packaging material field where transparency is required, the smaller the HAZE, which is one of the measures of transparency, the less the cloudiness of the film and the better the commercial value. In a 30 μm thick film, if it exceeds 5%, the commercial value is inferior. The water-cooled blown polypropylene film of the present invention is excellent in transparency as compared with the polypropylene film obtained by the conventional water-cooled blown film, has a small HAZE, generally 3% or less, and further 2.5% or less, which is extremely excellent in transparency. It has the characteristics.
In addition, HAZE of the film in this invention is measured based on JIS-K7136-2000.

(4-2) Impact resistance The water-cooled inflation-molded polypropylene film of the present invention is characterized by excellent impact resistance. There are various methods for evaluating the impact resistance of the film. In the present invention, the punching impact strength is used for the evaluation of the impact resistance evaluation.
The punching impact strength required varies depending on the contents and the state of use, but when packaging relatively heavy products such as liquids and fruits and vegetables, tearing occurs when packaging is generally less than 1,000 J / mm It is easy to do and is not preferable. Usually, a polypropylene film has a small value so that it is not used in a field where impact resistance is required.
On the other hand, the film obtained in the present invention is excellent in impact resistance, is generally 3000 J / mm or more, and has a characteristic that it exhibits an extremely high value of 5000 J / mm or more and further 7000 J / mm or more. It can also be suitably used in fields where strength is required.

(4-3) Tensile Elastic Modulus The water-cooled inflation molded polypropylene film of the present invention is further characterized by excellent flexibility. The flexibility of the film increases and becomes more flexible as the tensile modulus is lower. If the tensile modulus is high, the film becomes stiff and the waist strength is improved, but the feeling of firmness becomes strong, and when the contents are flexible foods, there is a problem that they are easily damaged.
The film obtained by the present invention has a characteristic that it has a low elastic modulus and excellent flexibility, is generally 600 MPa or less, and is excellent in flexibility such as 400 MPa or less, and further 300 MPa or less.

7). Applications The water-cooled inflation-molded polypropylene film obtained by the present invention has no whiteness, a clear transparency, and is excellent in flexibility and impact resistance as compared with the water-cooled inflation-molded polypropylene film obtained by the conventional technology. Since the opening property is good, it is easy to process and use, and it has a very high commercial value as a packaging material.
Although it does not specifically limit as a use, It uses suitably for packaging uses, such as a foodstuff, clothing, a medicine, stationery, and miscellaneous goods. Among these, it is particularly suitable for food and medical use because of its low odor characteristics. More specifically, a confectionery wrapping material, a retort wrapping material, an infusion bag, etc. are mentioned.

In the following, in order to more specifically and clearly describe the present invention, the present invention will be described in contrast to examples and comparative examples to demonstrate the rationality and significance of the requirements of the configuration of the present invention.
The evaluation methods and resins used in the examples and comparative examples are as follows.

[Method for measuring physical properties of propylene-ethylene block copolymer (A)]
1) Melt flow rate (MFR)
According to JIS K7210 A method condition M, it measured on condition of the following.
Test temperature: 230 ° C
Nominal weight: 2.16kg
Die shape: Diameter 2.095mm Length 8.00mm

2) TREF
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 caused 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-dichlorobenzene (containing 0.5 mg / ml BHT)
Sample concentration: 5 mg / ml
Sample injection volume: 0.1 ml
Solvent flow rate: 1 ml / min

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

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

5) GPC
The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured by gel permeation chromatography (GPC).
Conversion from the retention volume to the molecular weight is performed using a calibration curve prepared in advance with standard polystyrene. The measurement method is the method detailed in paragraph 0041.

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

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

8) Calculation of ethylene content According to the method detailed in paragraphs 0032-0036.

[Production Example PP-1]
[Polymerization Production Example A-1]
Preparation of prepolymerization catalyst (chemical treatment of ion-exchange layered silicate) In a glass separable flask equipped with a 10-liter stirring blade, 3.75 liters of distilled water, followed by 2.5 kg of concentrated sulfuric acid (96%) Slowly added. At 50 ° C., 1 kg of montmorillonite (Menzawa Chemical Co., Ltd. Benclay SL; average particle size = 25 μm, particle size distribution = 10-60 μm) was dispersed, heated to 90 ° C., and maintained at that temperature for 6.5 hours. After cooling to 50 ° C., the slurry was filtered under reduced pressure to recover the cake. 7 liters of distilled water was added to this cake to reslurry it, and then filtered. This washing operation was performed until the pH of the washing solution (filtrate) exceeded 3.5. The collected cake was dried at 110 ° C. overnight under a nitrogen atmosphere. The weight after drying was 707 g.
(Drying of ion-exchanged layered silicate) The silicate previously chemically treated was dried by a kiln dryer. Specifications and drying conditions are as follows.
Rotating cylinder: Cylindrical inner diameter 50 mm Heating zone 550 mm (electric furnace) Number of rotations with lifting blade: 2 rpm Tilt angle: 20/520 Silicate feed rate: 2.5 g / min Gas flow rate: Nitrogen 96 liters / hour Countercurrent drying Temperature: 200 ° C (powder temperature)
(Preparation of catalyst) An autoclave having an internal volume of 16 liters having a stirring and temperature control device was sufficiently replaced with nitrogen. 200 g of the silicate was introduced, 1,160 ml of mixed heptane and 840 ml of a heptane solution of triethylaluminum (0.60 M) were added and stirred at room temperature. After 1 hour, the mixture was washed with mixed heptane to prepare a silicate slurry to 2,000 ml. Next, 9.6 ml of a heptane solution of triisobutylaluminum (0.71 ML) was added to the silicate slurry prepared above and reacted at 25 ° C. for 1 hour. In parallel, 270 ml of (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azulenyl}] zirconium and 2,180 mg (0.3 mM) of mixed heptane Then, 33.1 ml of a heptane solution of triisobutylaluminum (0.71 M) was added, and the mixture reacted at room temperature for 1 hour was added to the silicate slurry. After stirring for 1 hour, 5,000 ml was added with mixed heptane. Prepared.
(Preliminary polymerization / washing) Subsequently, the temperature in the tank was raised by 40 ° C., and when the temperature was stabilized, propylene was supplied at a rate of 100 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 residual monomer was purged, stirring was stopped and the mixture was allowed to stand for about 10 minutes, and then the supernatant was decanted to 2,400 ml. Subsequently, 9.5 ml of a heptane solution of triisobutylaluminum (0.71 ML) and 5600 ml of mixed heptane were further added, stirred for 30 minutes at 40 ° C., allowed to stand for 10 minutes, and then 5600 ml of the supernatant was removed. This operation was further repeated 3 times. When the component analysis of the final supernatant was performed, the concentration of the organoaluminum component was 1.23 mmol / liter, the Zr concentration was 8.6 × 10 −6 g / L, It was 0.016%. Subsequently, 170 ml of a heptane solution of triisobutylaluminum (0.71 ML) was added, followed by drying at 45 ° C. under reduced pressure. A prepolymerized catalyst containing 2.0 g of polypropylene per 1 g of catalyst was obtained.

First Step In the first step, propylene-ethylene random copolymerization was carried out using a liquid phase polymerization tank with a stirrer having an internal volume of 0.4 m ³ . Liquefied propylene, liquefied ethylene and triisobutylaluminum were continuously fed at 90 kg / hr, 4.2 kg / hr and 21.2 g / hr, respectively. The hydrogen supply amount was adjusted so that the MFR in the first step became a target value. Further, the above prepolymerized catalyst was supplied as a catalyst (excluding the weight of the prepolymerized polymer) so as to be 6.9 g / hour. The polymerization tank was cooled so that the polymerization temperature was 45 ° C.
When the obtained propylene-ethylene random copolymer was analyzed, BD (bulk density) was 0.46 g / cc, MFR was 7.0 g / 10 min, and ethylene content was 3.7 wt%.

Second Step In the second step, propylene-ethylene random copolymerization was performed 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 66.97 vol%, 32.99 vol%, and 420 vol ppm, respectively. Furthermore, ethanol was supplied to the gas phase polymerization tank as an activity inhibitor. The supply amount of ethanol was set to 0.3 mol / mol with respect to aluminum in TIBA supplied along with the polymer particles supplied to the gas phase polymerization tank.
Analysis of the resulting propylene-ethylene block copolymer revealed an activity of 8.7 kg / g-catalyst, a BD of 0.41 g / cc, an MFR of 7.0 g / 10 min, and an ethylene content of 8.7 wt%. Met.

(Granulation)
An antioxidant, a neutralizing agent, an antiblocking agent, and a lubricant were added to the block copolymer powder obtained in Polymerization Production Example A-1 by a blender, and the mixture was sufficiently stirred and mixed.
Antioxidant: Tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (manufactured by Ciba Specialty Chemicals, Inc., Irganox 1010) 0.05 Parts by weight, tris (2,4-di-t-butylphenyl) phosphite (manufactured by Ciba Specialty Chemicals Co., Ltd. Irgafos 168) 0.10 parts by weight neutralizing agent: calcium stearate (manufactured by Nippon Oil & Fats Co., Ltd.) Stearate G) 0.05 part by weight anti-blocking agent: synthetic silica (Silicia 430 manufactured by Fuji Silysia Co., Ltd., particle size 2 μm) 0.40 part by weight Lubricant: oleic acid amide (manufactured by Nippon Seika Co., Ltd. Neutron) 0.30 parts by weight

  The copolymer powder to which the additive has been added is mixed at a high speed at 750 rpm for 1 minute at room temperature with a Henschel mixer, and then a screw rotation speed of 200 rpm, a discharge rate of 10 kg / hr, The melted resin is melt kneaded at an extruder temperature of 190 ° C., 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 cut into a length of about 3 mm and a diameter of about 2 mm using a strand cutter. -The raw material pellet (PP-1) of the ethylene block copolymer was obtained.

(analysis)
Using the obtained PP-1 pellets, TREF, ethylene content, DSC, GPC, CXS, CXS [η], solid viscoelasticity, and Vicat softening point temperature were measured.
Table 4 shows each data obtained by the measurement.
From the measurement results obtained, it can be said that PP-1 satisfies all requirements as a propylene-ethylene block copolymer.
Here, in order to show the position of each parameter in the TREF measurement result, an elution curve is illustrated in FIG. In order to show the position of each parameter in the solid viscoelasticity measurement results, FIG. 2 illustrates changes in storage elastic modulus G ′, loss elastic modulus G ″ and loss tangent tan δ with respect to temperature.

[Production Example PP-1B]
In the propylene-ethylene block copolymer obtained in Polymerization Production Example A-1, not the anti-blocking agent (Silicia 430) used in Production Example PP-1, but Silysia 770 (manufactured by Fuji Silysia Ltd., synthetic silica, granules) PP-1B raw material pellets were obtained by the same additive formulation and granulation conditions as in Production Example PP-1 except that the anti-blocking agent (diameter 6 μm) was used. Various analysis results were the same as in Production Example PP-1. Met.
[Production Example PP-1C]
As in Production Example PP-1, except that the amount of oleic acid amide used in Production Example PP-1 was changed to 0.8 parts by weight in the propylene-ethylene block copolymer obtained in Polymerization Production Example A-1. PP-1C raw material pellets were obtained according to the additive formulation and granulation conditions. Various analysis results were the same as those of Production Example PP-1.

[Production Example PP-2]
[Polymerization Production Example A-2]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-2 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.
PP-2 raw material pellets were obtained from the block copolymer powder obtained in Polymerization Production Example A-2 under the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-3]
[Polymerization Production Example A-3]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-3 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-4]
[Polymerization Production Example A-4]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-4 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-5]
[Polymerization Production Example A-5]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-5 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-6]
[Polymerization Production Example A-6]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-6 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-7]
[Polymerization Production Example A-7]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-7 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-8]
[Polymerization Production Example A-8]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-8 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-9]
[Polymerization Production Example A-9]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-9 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-10]
[Polymerization Production Example A-10]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-10 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-11]
[Polymerization Production Example A-11]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-11 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-12]
[Polymerization Production Example A-12]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-12 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-13]
[Polymerization Production Example A-13]
In Polymerization Production Example A-1, polymerization was carried out in the same manner as in Polymerization Production Example A-1, except that only the first step was carried out without carrying out the second step, to produce a propylene-ethylene random copolymer. Went. The polymerization conditions and polymerization results are shown in Table 3.
PP-13 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-14]
[Polymerization Production Example A-14]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-14 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-15]
[Polymerization Production Example A-15]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-15 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-16]
[Polymerization Production Example A-16]
(Preparation of solid catalyst component)
2,000 milliliters of dehydrated and deoxygenated n-heptane was introduced into a flask thoroughly purged with nitrogen, and then 2.6 mol of MgCl ₂ and 5.2 mol of Ti (On-C ₄ H ₉ ) ₄ were introduced. The mixture was introduced and reacted at 95 ° C. for 2 hours. After completion of the reaction, the temperature was lowered to 40 ° C., and then 320 ml of methylhydropolysiloxane (20 centistokes) was introduced and reacted for 3 hours. The resulting solid component was washed with n-heptane.
Next, 4,000 milliliters of n-heptane purified in the same manner as described above was introduced into a sufficiently nitrogen-substituted flask, and 1.46 mol of the solid component synthesized above was introduced in terms of Mg atoms. Next, 25 ml of n-heptane was mixed with 2.62 mol of SiCl ₄ , introduced into the flask at 30 ° C. for 30 minutes, and reacted at 70 ° C. for 3 hours. After completion of the reaction, washing with n-heptane was performed. Next, 0.15 mol of phthalic acid chloride was mixed with 25 ml of n-heptane, introduced into the flask at 70 ° C. for 30 minutes, and reacted at 90 ° C. for 1 hour. After completion of the reaction, washing with n-heptane was performed. Next, 11.4 mol of TiCl ₄ was introduced and reacted at 110 ° C. for 3 hours. After completion of the reaction, the solid component (A1) was obtained by washing with n-heptane. The titanium content of this solid component was 2.0 wt%.
Next, the autoclave having an internal volume of 16 liters having a stirring and temperature control device was sufficiently replaced with nitrogen, and 5,000 milliliters of n-heptane purified in the same manner as above was introduced into the solid component (A1 ) Was introduced, and 0.875 mol of SiCl ₄ was introduced and reacted at 90 ° C. for 2 hours. After completion of the reaction, further (CH ₂ ═CH) Si (CH ₃ ) ₃ 0.15 mol, (t-C ₄ H ₉ ) (CH ₃ ) Si (OCH ₃ ) ₂ 0.075 mol and Al (C ₂ H ₅ ) ₃ 0.4 mol was sequentially introduced and contacted at 30 ° C. for 2 hours. After completion of the contact, the solid catalyst component (A) mainly composed of magnesium chloride was obtained by thoroughly washing with n-heptane. The titanium content of this product was 1.8 wt%.
(Preliminary polymerization)
An autoclave with an internal volume of 16 liters equipped with a stirring and temperature control device was sufficiently replaced with nitrogen. 100 g of the n-heptane slurry of the solid catalyst component (A) prepared above was introduced here as the solid catalyst component (A), and n-heptane was further introduced to adjust the liquid level to 5,000 ml. Next, the temperature in the tank was adjusted to 15 ° C., and 0.1 mol of triethylaluminum / n-heptane solution (10 wt%) was added as Al (C ₂ H ₅ ) ₃ . Thereafter, prepolymerization was performed by supplying propylene at a rate of 50 g / hour for 2 hours. After completion of the prepolymerization, the residual monomer was purged, and the solid catalyst was thoroughly washed with n-heptane. After the washing, drying under reduced pressure was performed to obtain a prepolymerized catalyst. The prepolymerized catalyst contained 2.0 g of polypropylene per 1 g of the solid catalyst component.
Polymerization Production Example A-1 except that the obtained prepolymerization catalyst was used and triethylaluminum was continuously supplied at 10 g / hour instead of triisobutylaluminum, and the polymerization conditions shown in Table 3 were used. Propylene-ethylene block copolymer was produced in the same manner. The polymerization results are shown in Table 3.
PP-16 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-17]
[Polymerization Production Example A-17]
In the same manner as in Polymerization Production Example A-16, the polymerization conditions were changed to produce a propylene-ethylene block copolymer. The polymerization conditions and polymerization results are shown in Table 3. PP-17 raw material pellets were obtained from the obtained polymer powder by the same additive formulation and granulation conditions as in Production Example PP-1. Various analysis results are shown in Table 4.

[Production Example PP-18]
In addition to the same additives as in Production Example PP-1, the propylene-ethylene block copolymer obtained in Polymerization Production Example A-17 was added as an organic peroxide (2,5-dimethyl-2,5-bis ( (Tert-butylperoxy) hexane) 0.05 parts by weight was added, and PP-18 raw material pellets were obtained under the same granulation conditions as in Production Example PP-1. The obtained pellets had a strong acid odor due to decomposition of organic peroxides or residuals, and had a yellowish hue. Various analysis results are shown in Table 4.

[Example-1]
(Film forming)
PP-1 pellets were water-cooled by inflation molding under the following conditions using the following molding machine.
Extruder: caliber 45 mm / D = 24, grooved barrel type, temperature control 3 zone screw: feed section groove depth 4 mm, metering section groove depth 2 mm, mixing temperature setting of Maddock mixing section and dull image mixing section extruder : Hopper water cooling, 180, 190, 190 from feed side
Die: 120mm diameter φ spiral mandrel die, lip width 1mm
Die setting temperature: Adapter 190 ° C Die body 190 ° C
Cooling ring: Water-cooled mandrel system Water temperature 20 ° C
Discharge rate: 17kg / h (adjusted by screw speed)
Blow ratio (ratio of bubble diameter to die diameter): 1.1
Take-off speed: 20 m / min Film thickness: 30 μm

〔Evaluation of the physical properties〕
1) HAZE
The obtained film was conditioned at 23 ° C. under an atmosphere of 50% RH for 24 hours, and then measured with a haze meter according to JIS-K7136-2000. The smaller the value obtained, the better the transparency.
2) Evaluation of bleed-out 1) The film measured by HAZE was left in a constant temperature bath at 40 ° C. for 1 week, and then left at 23 ° C. in an atmosphere of 50% RH for 2 hours to adjust the condition. HAZE was measured according to -K7136-2000. The difference between HAZE after 1 week at 40 ° C. and HAZE measured at 23 ° C., 50% RH for 24 hours was determined, and the amount of bleed out was evaluated. The greater the difference in HAZE, the greater the amount of bleed out.
3) Opening property The opening property of the tubular film immediately after film formation and after 10 minutes was evaluated according to the following criteria.
◎: Open by simply shaking light ○: Ordinarily twist with your finger to open once △: Strongly twist with your finger to open once ×: Slightly twist with your finger to hardly open 4) Slip (slip) )
The resulting film was conditioned at a temperature of 23 ° C. under an atmosphere of 50% RH for 24 hours, and the friction between the inner surfaces of the tubes was evaluated by a static test coefficient by a slip tester method in accordance with ASTM-D1894. The smaller this value, the better the slipperiness.
5) Punching impact strength In accordance with JIS-P8134, the obtained film was allowed to stand for 24 hours or more in an atmosphere of 50% RH at 23 ° C., and after adjusting the condition, a film impact tester manufactured by Toyo Seiki Seisakusho was used. The measurement was performed at 23 ° C. in an atmosphere of 50% RH (unit: J / mm). The penetrating part used was a 25.4 mmφ hemispherical metal. The larger this value, the better the impact resistance.
6) Tensile elastic modulus: Based on JIS K-7127-1989, the tensile elastic modulus in each of the film flow direction (MD) and the orthogonal direction (TD) was measured under the following conditions.
Sample length: 150mm
Sample width: 15mm
Distance between chucks: 100mm
Crosshead speed: 1mm / min
7) Tear strength Measured by the Elmendorf tear method according to JIS-K7128-1991, with the take-up direction at the time of forming the obtained film as the vertical direction (MD) and the direction perpendicular to the take-off direction (TD) : N / mm). The larger this value, the better the tear strength.
8) Odor A 300 ml Erlenmeyer flask with a stopper is filled with a film sample obtained so that the volume of the Erlenmeyer flask becomes about 1/2, and then stoppered, heated in a thermostatic bath at 80 ° C. for 2 hours, and then taken out. Odor sensory evaluation was performed within 10 minutes according to the following criteria.
○: Odorless or slightly odor is felt Δ: Slightly odor ×: Smelly odor xx: Smelly violent Table 5 shows the evaluation results of the above physical properties.

[Examples 2 and 3]
A film was formed and evaluated in the same manner as in Example 1 except that PP-1B and 1C having different additive blends from PP-1 were used as raw materials. The evaluation results are shown in Table 5.
[Examples 4 to 12]
A film was formed and evaluated in the same manner as in Example 1 except that PP-2 to 10 were used as raw materials. The evaluation results are shown in Table 5.

[Comparative Example-1]
A film was formed in the same manner as in Example 1 except that PP-11 was used as a raw material. The film had a pronounced sharkskin and the appearance was very poor. Table 5 shows the quality evaluation results.
[Comparative Example-2]
A film was formed in the same manner as in Example 1 except that PP-12 was used as a raw material. Since the bubbles became unstable at the time of molding and a film having a uniform thickness could not be obtained, the physical properties could not be evaluated.
[Comparative Examples-3 to 8]
Except for using PP-13 to 18 as a raw material, film forming was performed and evaluated in the same manner as in Example-1. The evaluation results are shown in Table 5.

[Consideration by contrast between Example and Comparative Example]
Considering each of the above examples and each comparative example in comparison, in the water-cooled blown film molded using the novel propylene-ethylene block copolymer of the present invention that satisfies the respective regulations in the configuration of the present invention. It is clear that it has excellent transparency and impact resistance, has good flexibility, further suppresses bleed-out, improves film slipperiness, openability and tear strength, and has less odor. It is understood that each provision of the constituent features of the present invention is reasonable and significant and is confirmed by experimental data.

Specifically, in Comparative Example-1, the MFR of the propylene-ethylene block copolymer is too low, the surface appearance is deteriorated due to the remarkable generation of shark skin, and the transparency is also poor. In Comparative Example-2, the MFR of the propylene-ethylene block copolymer is too high, the bubbles become unstable, and stable film formation cannot be performed. In Comparative Example-3, since the raw material used is a normal propylene-ethylene random copolymer and does not contain the component (A2), the transparency is improved by using a metallocene catalyst, but the flexibility and impact resistance are improved. Lack of sex. In Comparative Example-4, tan δ in the solid viscoelasticity measurement does not have a single peak and takes a phase separation structure, and the transparency is significantly deteriorated. In comparative example-5, there are too many components (A2) and the opening property of a film is getting worse. In Comparative Example-6, a propylene-ethylene block copolymer polymerized using a Ziegler-Natta catalyst was used, but the transparency was poor, the bleed out was poor, and the slipping property and the opening property were also poor. In Comparative Example-7, a Ziegler-Natta catalyst was used as in Comparative Example-6 to increase the overall molecular weight and reduce low molecular weight components in order to improve stickiness and bleed out. It deteriorates and a film with excellent transparency cannot be obtained. In Comparative Example-8, in order to improve the appearance defect of Comparative Example-7, an attempt was made to improve the fluidity while reducing the molecular weight by adding an organic peroxide during granulation and suppressing the amount of low molecular weight components. However, although the film appearance was improved, the transparency was not excellent, and the odor was greatly deteriorated by the use of organic peroxide.
As described above, water-cooled inflation comprising the propylene-ethylene block copolymer of the present invention, which has excellent properties such as transparency, flexibility and impact resistance, less blocking and bleed-out, and excellent slip properties, openability and odor. In each comparative example, the quality is generally inferior to the molded film, and the superiority of the water-cooled inflation molded polypropylene film of the present invention is highlighted.

It is a graph which shows the elution amount curve and elution amount integration of PP-1 in polymerization manufacture example A-1. It is a graph which shows the solid viscoelasticity measurement of PP-1 in superposition | polymerization manufacture example A-1. It is a graph which shows the solid viscoelasticity measurement of PP-14 in superposition | polymerization manufacture example A-14.

Claims (9)

A water-cooled inflation-molded polypropylene film characterized by being molded by water-cooled inflation molding using a propylene-ethylene block copolymer satisfying the following conditions (Ai) to (A-iii) as a raw material.
(Ai) Using a metallocene-based catalyst, 30 to 95 wt% of propylene-ethylene random copolymer component (A1) having propylene alone or ethylene content of 7 wt% or less in the first step, and component (A1) in the second step It is a propylene-ethylene block copolymer (A) obtained by sequentially polymerizing 70 to 5 wt% of a propylene-ethylene random copolymer component (A2) containing 3 to 20 wt% more ethylene than ( A-ii) Melt flow rate (MFR: 230 ° C. 2.16 kg) is in the range of 1 to 20 g / 10 minutes (A-iii) Temperature-loss tangent (tan δ) obtained by solid viscoelasticity measurement (DMA) In the curve, the tan δ curve has a single peak below 0 ° C The water-cooled inflation molded polypropylene film according to claim 1, wherein the propylene-ethylene block copolymer (A) satisfies the following condition (A-iv).
(A-iv) The component amount W (Mw ≦ 5,000) of 5,000 or less in the molecular weight obtained by gel permeation chromatography (GPC) measurement is 0.8 wt% or less of the whole. The water-cooled inflation-molded polypropylene film according to claim 1 or 2, wherein the propylene-ethylene block copolymer (A) satisfies the following conditions (Av) to (A-vi): .
(Av) The component (A1) obtained in the first step is a propylene-ethylene random copolymer having an ethylene content in the range of 0.5 to 6 wt%, and the proportion of the block copolymer (A) in the whole Is in the range of 30 to 85 wt%, the component (A2) obtained in the second step is 6 to 18 wt% more ethylene content than (A1), and the proportion of the block copolymer (A) in the whole is 70 to (A-vi) Elution amount (dWt% / dT) with respect to temperature by temperature rising elution fractionation method (TREF) in a temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. ), The peak T (A1) observed on the high temperature side is in the range of 55 ° C. to 96 ° C., and the peak T (A2) observed on the low temperature side is below 45 ° C. , Or peak T (A2) is not observed, the total propylene - that ethylene block copolymer temperature 99 wt% of (A) is eluted T (A4) is 98 ° C. or less The water-cooled inflation molding according to any one of claims 1 to 3, wherein the propylene-ethylene block copolymer (A) satisfies the following conditions (A-vii) to (A-ix): Polypropylene film.
(A-vii) The component (A1) obtained in the first step is a propylene-ethylene random copolymer having an ethylene content in the range of 1.5 to 6 wt%, and the ratio of the entire block copolymer (A) Is in the range of 30 to 70 wt%, the component (A2) obtained in the second step is 8 to 16 wt% more ethylene content than (A1), and the proportion of the block copolymer (A) in the whole is 70 to 70 wt%. Elution amount (dWt% / dT) with respect to temperature by temperature rising elution fractionation method (TREF) in a temperature range of −15 ° C. to 140 ° C. using (A-ix) o-dichlorobenzene solvent. ), The peak T (A1) observed on the high temperature side is in the range of 60 ° C. to 88 ° C., and the peak T (A2) observed on the low temperature side is 40 ° C. or higher. It ethylene block copolymer temperature 99 wt% of (A) is eluted T (A4) is 90 ° C. or less - to have, or the peak T (A2) is not observed, the total propylene The water-cooled inflation molded polypropylene film according to any one of claims 1 to 4, wherein the propylene-ethylene block copolymer (A) satisfies the following condition (A-ix).
(A-ix) 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). 0.01-1.0 part by weight of an antiblocking agent having an average particle diameter of 1-7 μm and 0.01-1.0 part by weight of a fatty acid amide with respect to 100 parts by weight of the propylene-ethylene block copolymer (A). The water-cooled inflation molded polypropylene film according to any one of claims 1 to 5, wherein the film is blended. The water-cooled inflation-molded polypropylene film according to any one of claims 1 to 6, wherein the tensile elastic modulus is 400 MPa or less, and the punching impact strength at 23 ° C is 3000 J / mm or more. A polypropylene-based laminated film comprising at least one layer comprising a water-cooled inflation-molded polypropylene-based film according to any one of claims 1 to 7. A food packaging bag or a medical bag, which is made of the polypropylene film according to any one of claims 1 to 8, and is used after heat sterilization.

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