JP2006307120A - Propylene-based resin film and propylene-based resin laminated film and application thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a propylene-based resin film high in impact resistance and excellent in transparency and blocking resistance, etc. <P>SOLUTION: The propylene-based resin film meets the following requirements (A-i) to (A-iv): (A-i) It consists of a propylene-ethylene random block copolymer comprising 30-85 wt.% of (A1) a component obtained in a first step, 0.5-6 wt.% in ethylene content, synthesized using a metallocene-based catalyst and 70-15 wt.% of (A2) a component obtained in a second step, containing an ethylene component more than the component (A1) by 6-18 wt.%. (A-ii) In the TREF (temperature rising elution fractionation) elution curve, the peak T (A1) at higher temperature side falls within the range from 55°C to 96°C, while the peak T (A2) at lower temperature side falls below 45°C, and the temperature T (A4) at which 99 wt.% of the whole block copolymer is eluted is below 98°C. (A-iii) The MFR falls within the range of 1-50 g/10 min. (A-iv) The tanδ curve determined by solid viscoelasticity measurement has a single peak below 0°C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a propylene-based resin film, and in particular, has an appropriate flexibility and balance of transparency, blocking resistance, tear strength, impact resistance, heat resistance, low temperature heat sealability, and bending whitening resistance. The present invention relates to a propylene-based resin film and a propylene-based resin laminated film with little bleed-out and little odor, and uses thereof.

  Polypropylene film has various excellent properties such as transparency, rigidity and heat resistance, so it is widely used as packaging film for food, clothing, medicine, medicine, stationery, miscellaneous goods, industrial materials, industrial use, etc. It's being used. However, on the other hand, impact resistance, particularly low-temperature impact resistance is small, and heat sealability is inferior, so the use is somewhat limited.

In order to improve such a defect, a method of randomly copolymerizing ethylene as a copolymer component with propylene as a main component for the purpose of improving the impact resistance of a crystalline propylene resin is proposed (Patent Document 1). However, as the copolymerization ratio of ethylene increases, ethylene becomes easier to copolymerize with propylene, and when such a copolymer is used, the transparency of the film is significantly reduced, and blocking resistance and slippage are reduced. The film is significantly reduced, and the friction resistance during film processing hinders the speeding up of the film processing, the film is scratched, and the opening property of the obtained film bag material is extremely reduced. There was a drawback that a product suitable for the above could not be obtained.
A method for improving transparency and impact resistance by adding a nucleating agent to a specific propylene-based block copolymer has been proposed (Patent Document 2). However, there is a problem that the ethylene-containing component bleeds out over time and the transparency is lowered, and the balance between transparency and impact resistance does not necessarily satisfy the demand for high transparency.
In view of such problems, a propylene-based film having a good transparency and impact resistance made of a resin composition that specifies MFR, melting characteristics, and the like has also been proposed (Patent Document 3). For applications that require impact resistance, such as food packaging that is used at relatively low temperatures, such as vegetable packaging, a film with even higher impact strength is required, although the transparency is very good. Yes.
Furthermore, a propylene film having a good impact resistance and transparency composed of a specific resin composition and an elastomer has also been proposed (Patent Document 4). Although the impact resistance is very good, The transparency is lowered due to the influence of the blend, and it is not always satisfactory especially in the packaging field where high transparency is required.

On the other hand, studies have been made to improve the flexibility (flexibility), impact resistance, etc. of the resulting polypropylene film with polypropylene resins.
For example, the so-called block type reactor TPO, which produces crystalline polypropylene in the first step and propylene-ethylene copolymer elastomer in the second step, is more heat resistant and produced than random copolymer type elastomers. It has the characteristics that it has excellent properties, and has the advantageous characteristics that the quality of the product is stable and the manufacturing cost is reduced, and the composition of the elastomer can be widely varied, compared to the elastomer manufactured by mechanical mixing. It has high economic efficiency and has been very 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 elastomer or plastomer having excellent transparency and flexibility is realized, it is recognized as being extremely meaningful as a film 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 technique of continuously polymerizing relatively little propylene-ethylene copolymer elastomer using a Ziegler-Natta catalyst is disclosed (Patent Citation 5). However, since Ziegler-Natta catalysts have multiple types of active sites, the resulting propylene-ethylene copolymer has a broad crystallinity and molecular weight distribution, and produces many low-crystalline and low-molecular weight components, resulting in a sticky product. 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.
In order to improve this method, a method of increasing the intrinsic viscosity of the elastomer, that is, the molecular weight to a certain degree or more so as to suppress the formation of a low molecular weight component has been disclosed (Patent Document 6). The formation of the product has a small inhibitory effect, the transparency is not sufficient, the improvement of stickiness and bleed-out is still insufficient, and the high molecular weight of the elastomer causes the appearance defects such as butts and fish eyes. Since it becomes easy and extrudability deteriorates, there are many problems such as the use of an organic peroxide in the granulation step to significantly deteriorate odor.

A reactor TPO using a metallocene catalyst was developed after the reactor TPO produced using such a Ziegler-Natta catalyst. Polypropylene was used in the first step, propylene and ethylene and / or C4- A method of obtaining a propylene copolymer exhibiting a specific elution pattern in temperature rising elution fractionation by TREF by polymerizing an α-olefin of C18 has been disclosed, and the molecular weight distribution and crystallinity distribution are narrow. (Patent Document 7), and more specifically, elution up to 90 ° C. in a temperature-temperature elution fractionation method using an o-dichlorobenzene solvent consisting of a polypropylene component and a copolymer component of propylene and ethylene. The component that elutes at a temperature of 90 ° C. or higher is 50 to 99 wt% of the total It is disclosed that the above-mentioned problem is solved by a propylene-based resin composition that satisfies requirements such as 50 to 1 wt% of the body, and further the amount of the component eluted by 0 ° C is 10 wt% or less, However, the propylene-based resin film obtained by such a technique requires a large amount of low crystalline components to improve flexibility and impact resistance, and as a result, remarkable deterioration in heat resistance is seen, Moreover, the problem that the deterioration of blocking arises is presented.
More recently, a block type reactor TPO using a metallocene catalyst has also been disclosed, but a technology that improves the transparency, flexibility and impact resistance of polypropylene film in a well-balanced manner and applies it to packaging materials, etc. Is not yet seen.

By the way, from the viewpoint of environmental problems in recent years, various studies of alternative application of polypropylene film to surface protection films for which vinyl chloride films have been conventionally used have been conducted. For example, an adhesive layer or the like is laminated on polypropylene film Later, it has been studied to use it as a film for protecting a surface from being stained or scratched by being bonded to the surface of a metal plate such as stainless steel, a decorative plywood or a synthetic resin plate. Also, decorative sheets are often used on the surfaces of various interior and exterior building materials, joinery, home appliances, and office equipment, and a clear layer using a two-component curable urethane resin or the like is laminated on a polypropylene film. It has also been studied to form a film that protects the base material layer that is bonded to the outermost layer of the decorative sheet in the configuration and is subjected to wood grain printing or the like.
For example, the use of a soft propylene-based resin is proposed for such applications (Patent Document 8). If this material is used, there is no risk of toxic gas generation due to vinyl chloride, and the flexibility is high. When it is used as, it has processability equivalent to that of vinyl chloride resin for processing that requires processing followability such as bending workability. However, physical properties are not sufficient for bending whitening resistance and transparency, and it is necessary to perform MFR adjustment with an organic peroxide, resulting in a disadvantage that the manufacturing process is complicated.
In addition, although attempts have been made to apply highly crystalline polypropylene to the surface protective film of the decorative sheet (Patent Document 9), the resin is hard in this method, but the folding resistance when bending is performed. Bending whitening property is not sufficient, and a satisfactory surface protective film is not necessarily obtained.

Japanese Examined Patent Publication No. 3-54124 (Summary) JP 11-92619 A (summary) JP 11-269226 A (summary) Japanese Patent Laying-Open No. 2003-64194 (Summary and Claim 2) Japanese Patent Laid-Open No. 63-159212 (Claims, lower right column on page 2) JP-A-9-324022 (summary) JP 2000-239462 A (summary) JP-A-9-241442 (summary) JP 2000-246851 A (summary)

Problems to be solved by the invention

  As often described in the background art, even if propylene-based resins are widely used for packaging films because of their excellent performance, they do not have sufficient impact resistance, so a copolymer with ethylene or the like is added and a nucleating agent is added. Various improvement methods have been tried by setting the composition parameters with other resins, or adopting the reactor TPO, but improving the impact resistance, transparency, Since a resin material that uniformly satisfies many properties when used in the film field such as heat resistance and suppression of blocking and bleed-out has not yet been obtained, the present invention provides a specific reactor TPO based on a metallocene catalyst. Moderate flexibility, excellent transparency, low bleed out, blocking resistance, high tear strength, high impact resistance, heat resistance, low temperature heat seal In addition, the development of a propylene-based resin film having low odor property utilizing bending whitening resistance, etc., and providing a packaging material film having high practicality in many fields, is a problem to be solved by the invention. In order to expand the field of use, it is also an object of the present invention to expand its application to the surface protection film and to utilize it.

Means for solving the problem

  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 on the propylene-ethylene random block copolymer is also carried out, and an application has been filed as a previous invention (Japanese Patent Application No. 2003-371458 and others), but in order to effectively use this material as a film material, Utilizing such a prior invention, the above-mentioned problem of the present invention, which is highly necessary as a packaging material film, moderate flexibility, high impact resistance, transparency, low bleed out and blocking resistance, We decided to develop an effective method to improve various properties such as low odor and seek new applications.

  In order to find out such a technique, the present inventors use a metallocene catalyst, and in the first step, contain a propylene-ethylene random copolymer component containing ethylene in the first step, which contains more ethylene than in the first step. In the propylene-ethylene block copolymer obtained by sequentially polymerizing propylene-ethylene random copolymer components, the composition of each copolymer, ethylene content, crystallinity distribution, molecular weight distribution, and solid viscoelastic properties The process of conducting various trials under each of these conditions, including various considerations regarding elution characteristics in the elution fractionation method, temperature melt elution fractionation, melt flow rate, and various film forming methods and additives. In the above, it is possible to newly recognize requirements that can solve the above-described problems of the present invention, and further, a film forming method It is then, as possible to effectively use the T-die molding method capable of forming a film excellent in balance of transparency and surface properties and heat resistance, which resulted in the creation of the present invention.

  The basic requirements recognized as described above include a metallocene catalyst and a propylene-ethylene random copolymer component containing ethylene in the first step, and the second step from the first step. In the propylene-ethylene block copolymer obtained by sequentially polymerizing propylene-ethylene random copolymer components containing a large amount of ethylene, the component composition and ethylene content of each copolymer are specified, and such copolymer is A film is formed by T-die molding, and a tan δ curve is specified as elution characteristics, melt flow rate, and solid viscoelastic characteristics in the temperature-temperature elution fractionation method of a propylene-ethylene block copolymer.

Specifically, 30 to 85 wt% of the propylene-ethylene random copolymer component (A1) having an ethylene content of 0.5 to 6 wt% or less in the first step and 6 to 18 wt% of the component (A1) in the second step. A propylene-ethylene random copolymer component (A2) containing a large amount of ethylene is successively polymerized in an amount of 70 to 15 wt%, and in the block copolymer, the temperature range of the elution peak in the temperature-temperature elution fractionation method is defined, and T From the moldability of the die method, the melt flow rate (MFR) is in the range of 1 to 50 g / 10 min, and the temperature-loss tangent (tan δ) obtained by solid viscoelasticity measurement (DMA) for improving the transparency of the film. ) In the curve, the tan δ curve has a single peak at 0 ° C. or lower.
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, molecular weight obtained by gel permeation chromatography (GPC) measurement, intrinsic viscosity [η] cxs measured in 135 ° C. decalin of 23 ° C. xylene soluble component, and film blocking resistance In order to increase the anti-blocking agent and its blending amount are also specified.

The present invention effectively utilizes the characteristics of the propylene resin film that are excellent in the balance of transparency, gloss, and heat resistance obtained by the T-die molding method, and also improves impact resistance and has an appropriate flexibility (flexibility). Propylene-ethylene random, a block type reactor TPO, that can suppress bleed-out, blocking, and odor, and can also form a film with excellent transparency, flexibility and film opening. The block copolymer can be effectively used as a film material. Such a propylene resin film has high impact resistance, extremely excellent transparency, high heat resistance, and excellent flexibility. It can be used very suitably for use as a packaging material such as a surface protective film that requires folding whitening.
Accordingly, these features and the requirements of the configuration described in paragraph 0013 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 propylene-based resin molded by a T-die molding method using a propylene-ethylene random block copolymer (A) satisfying the following conditions (Ai) to (A-iv) as a raw material Resin film.
(Ai) Propylene-ethylene random copolymer in which the ethylene content of the component (A1) obtained in the first step is in the range of 0.5 to 6 wt% using the metallocene-based catalyst, the proportion in the whole (A) 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 ratio in the whole (A) is in the range of 70 to 15 wt%. (A-ii) It is obtained as a plot of elution amount (dWt% / dT) against temperature by the temperature rising elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. In the TREF elution curve, 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 the peak (A2) is not observed, and the temperature T (A4) at which 99 wt% of the total propylene-ethylene block copolymer elutes is 98 ° C. or less. (A-iii) Melt flow rate (MFR; 2.16 kg 230 ° C.) ) Is in the range of 1 to 50 g / 10 min. (A-iv) In the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA), the tan δ curve has a single peak below 0 ° C. [2] The propylene-based resin film described in [1], wherein the propylene-ethylene random block copolymer (A) satisfies the following conditions (A-v).
(Av) The component amount W (Mw ≦ 5,000) of 5,000 or less in the molecular weight of the block copolymer obtained by gel permeation chromatography (GPC) measurement is 0. [3] The propylene-ethylene random block copolymer (A) satisfies the following conditions (A-vi) to (A-vii): [1] to [3] The propylene-based resin film described in any of the above.
(A-vi) The propylene-ethylene random copolymer in which the ethylene content of the component (A1) obtained in the first step is in the range of 1.5 to 6 wt%, and the proportion in the whole (A) is in the range of 30 to 70 wt%. The component (A2) obtained in the second step contains 8 to 16 wt% more ethylene than (A1), and the ratio in the whole (A) is in the range of 70 to 30 wt%.
(A-vii) TREF obtained as a plot of elution amount (dWt% / dT) against temperature by temperature-elevated elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using o-dichlorobenzene solvent In the elution curve, the peak T (A1) observed on the high temperature side is in the range of 60 ° C. to 88 ° C., the peak T (A2) observed on the low temperature side is 40 ° C. or lower, or the peak T (A2) Is not observed, and the temperature T (A4) at which 99% by weight of the total propylene-ethylene block copolymer elutes is 90 ° C. or lower. [4] The propylene-ethylene random block copolymer (A) has the following conditions ( The propylene-based resin film described in any one of [1] to [4], wherein A-ix) is satisfied.
(A-viii) The intrinsic viscosity [η] cxs measured in a decalin at 135 ° C. of the 23 ° C. xylene soluble component is in the range of 1 to 2 (dl / g). [5] For propylene-ethylene random block [1] to [4], wherein 0.01 to 1.0 part by weight of an antiblocking agent having an average particle diameter of 1 to 7 μm is blended with respect to 100 parts by weight of the polymer (A). The propylene-type resin film described in any one.
[6] Any of [1] to [5], wherein 0.01 to 1.0 part by weight of fatty acid amide is contained with respect to 100 parts by weight of the propylene-ethylene random block copolymer (A). The propylene-based resin film described in the above.
[7] A propylene-based resin laminate comprising at least one layer composed of the propylene-based resin film described in any one of [1] to [6], and molded using a T-die coextrusion molding method the film.
[8] A food packaging bag material comprising the propylene-based resin film or the propylene-based resin laminated film described in any one of [1] to [7], and being used after being heat-sterilized. Or medical packaging bag material.
[9] A surface protective film using the propylene-based resin film or the propylene-based resin laminated film described in any one of [1] to [7].

The invention's effect

The propylene-based resin film and the propylene-based resin laminated film obtained by the T-die molding method in the present invention have high impact resistance, have moderate flexibility (flexibility), transparency, blocking resistance, Tear strength, heat resistance, low-temperature heat sealability, bending whitening resistance, etc. are excellent in balance, bleeding out is suppressed, and propylene-based resin films and propylene-based resin laminated films with little odor can be put into practical use.
In addition, it is used for food packaging bags, medical packaging bags, metal plates, decorative plywood, synthetic resin plates, surface protection films, various interior and exterior building materials, joinery, home appliances, and office equipment. It can use suitably for the surface protection film use of the used decorative sheet.

1. Configuration of Propylene-Ethylene Random Block Copolymer (A) (1) Basic Rules The propylene-ethylene random block copolymer (A) used in the propylene-based resin film in the present invention is a first metallocene catalyst. 30 to 85 wt% of propylene-ethylene random copolymer component (A1) having an ethylene content of 0.5 to 6 wt% or less in the step, and propylene containing 6 to 18 wt% more ethylene than the first step in the second step It can be obtained by successively polymerizing 70 to 15 wt% of the ethylene random copolymer component (A2).
Such a propylene-ethylene block copolymer is commonly called a so-called block copolymer, but is in a blended state of component (A1) and component (A2), and both are bonded by polymerization. It is not what you have.

(2) Component (A1) (2-1) Ethylene content E in component (A1) E (A1)
Component (A1) produced in the first step is propylene having a relatively high melting point and a crystalline ethylene content in the range of 0.5 to 6 wt% in order to suppress stickiness and develop heat resistance. -It must be an ethylene random copolymer. If the ethylene content exceeds 6 wt%, the melting point becomes too low and the heat resistance is deteriorated, so the ethylene content is set to 6 wt% or less.
In the case where the component (A1) is a propylene homopolymer, the ratio of the component (A2) needs to be extremely increased in order to exhibit sufficient flexibility while maintaining transparency. It causes noticeable deterioration such as stickiness and blocking.
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.
Further, by reducing the melting point, even if the molding temperature at the time of T-die molding is lowered, a sufficient propylene stability can be obtained, whereby a propylene-based resin film having extremely excellent odor can be obtained.
From these viewpoints, the ethylene content in the component (A1) needs to be 0.5 wt% or more, preferably 1.5 wt% or more.

(2-2) Proportion of component (A1) in propylene-ethylene random block copolymer (A) If the proportion of component (A1) in propylene-ethylene random block copolymer (A) is too large, propylene -The effect of improving the flexibility, impact resistance and transparency of the ethylene random block copolymer (A) cannot be exhibited sufficiently. Therefore, the proportion of component (A1) is 85 wt% or less, preferably 70 wt% or less.
On the other hand, when the proportion of the component (A1) is 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 necessary for improving the flexibility and impact resistance and transparency of the propylene-ethylene random block copolymer (A). It is an ingredient.
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 propylene-ethylene random block copolymer (A) 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 propylene-ethylene random Since the ethylene content E (A2) in the component (A2) is controlled by the ethylene content in the copolymer, the effect is effective unless the ethylene content E (A1) in the component (A1) is 6 wt% or more. It cannot be exhibited, and preferably contains 8 wt% or more ethylene more than the component (A1).
Here, when the difference in ethylene content between the component (A1) and the component (A2) is defined as E (gap) (= E (A2) −E (A1)), E (gap) is 6 wt% or more, preferably 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 case of propylene-ethylene random copolymers, the compatibility between them is different when the difference in ethylene content increases. The upper limit of E (gap) may be within a range in which the peak of tan δ is single by solid viscoelasticity measurement described later in paragraph 0026. For that purpose, E (gap) is 18 wt% or less, preferably 16 wt%. The range is as follows.

(3-2) Proportion of component (A2) in propylene-ethylene random block copolymer (A) If the proportion of component (A2) is too large, stickiness increases and blocking is deteriorated, and heat resistance is also reduced. In order to become remarkable, it is necessary to suppress the ratio of the component (A2) 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. Therefore, the proportion of (A2) needs to be 15 wt% or more, preferably 30 wt% or more. It is.

(4) Propylene-ethylene random block copolymer (A) melt flow rate (MFR)
The MFR of the propylene-ethylene random block copolymer (A) used for the polypropylene film of the present invention needs to be in the range of 1 to 50 g / 10 min. That is, in order to achieve the transparency and physical properties of the film which is the object of the present invention, it is necessary to adopt the molding conditions described above. However, if the 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 remarkably impaired. 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 random block copolymer (A) must be in the range of 1 to 50 g / 10 min, preferably 2 to 30 g / 10 min, more preferably 4 to 15 g / min. A range of 10 minutes 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 is according to JISK7210A method condition M Test temperature: 230 degreeC Nominal load: 2.16kg Die shape: Diameter 2.095mm Length 8.00mm
It was measured under the conditions of

(5) Solid viscoelasticity measurement (5-1) Specification by peak of tan δ curve The propylene-ethylene random 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 propylene-ethylene random 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.
The propylene-ethylene random block copolymer used in the present invention needs to have a single peak in the tan δ curve in solid viscoelasticity measurement in order to exhibit transparency.
In addition, the example of the peak of a tan-delta curve is shown in FIG.2 and FIG.3 as an example in superposition | polymerization manufacture example-1 and the superposition | polymerization manufacture example-14 in the case of not having a single peak.

(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 sharp peak is shown in a temperature range of 0 ° C. or lower. Generally, 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) Specific components (A1) and (A2) of ethylene content E (A1) and E (A2) of each component of components (A1) and (A2), and each component amount W (A1) and W (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, the following analysis (fractionation method) should be used. Is desirable.

(6-1) Identification of component amounts W (A1) and W (A2) by temperature-temperature elution fractionation (TREF) The method of evaluation is well known to those skilled in the art, and for example, detailed measurement methods are shown in the following documents.
G. Glockner, J. et al. Appl. Polym. Sci. : Appl. Polym. 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 random 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.

6-1-2. TREF elution curve In the TREF elution curve (plot of elution amount against temperature), components (A1) and (A2) show their elution peaks in T (A1) and T (A2), respectively, due to the difference in crystallinity. Since it is sufficiently large, separation is possible at an intermediate temperature T (A3) (= {T (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 in the range. (At this time, the concentration of the component (A2) dissolved in the solvent is detected at the measurement temperature lower limit (that is, −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 −15 ° C., which is the lower limit of the measurement temperature. It is defined as
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 device (carbon nuclear resonance frequency of 100 MHz or more)
Solvent: o-dichlorobenzene / heavy benzene = 4/1 (volume ratio)
Concentration: 100 mg / ml
Temperature: 130 ° C
Pulse angle: 90 °
Pulse interval: 15 seconds Integration count: 5,000 times or more The attribution of the spectrum may be performed with reference to Macromolecules 17 1950 (1984), for example. 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 (T _ββ ) (1)
[PPE] = k × I (T _βδ ) (2)
[EPE] = k × I (T _δδ ) (3)
[PEP] = k × I (S _ββ ) (4)
[PEE] = k × I (S _βδ ) (5)
[EEE] = k × {I (S _δδ ) / 2 + I (S _γδ ) / 4} (6)
Here, [] indicates the fraction of triads, for example, [PPP] is the fraction of PPP triads in all triads.
Therefore, [PPP] + [PPE] + [EPE] + [PEP] + [PEE] + [EEE] = 1 (7)
It is. Further, k is a constant, I indicates a spectral intensity, and for example, I (T _ββ ) means the intensity of a 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
The propylene-ethylene random block copolymer used in the present invention contains a small amount of propylene heterogeneous bonds (2,1-bonds and / or 1,3-bonds). A peak is produced.

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 to specify the amount of each component, the propylene-ethylene random block copolymer used in the present invention is used. Additional features can be found in the crystalline distribution.
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 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, the component (A1) is a random copolymer in the range of 0.5 to 6 wt% of ethylene, but T (A1) can be lowered by increasing the ethylene content. At this time, in order to exhibit sufficient balance between flexibility, transparency, and heat resistance, T (A1) needs to be 96 ° C. or lower, and a preferable range is 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) needs to be 55 ° C. or higher, and 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 to the high crystal side can be evaluated by TREF measurement, and the elution end temperature T (A4) of the entire propylene-ethylene random block copolymer with respect to the peak temperature T (A1) (however, TREF measurement Since it is difficult to define the temperature at which all elution occurs, it is preferable that the temperature at which 99 wt% is eluted is defined as the elution end temperature T (A4)) is not high. If there is an elution component on the side, the crystallinity of the component will increase. Therefore, in the propylene-ethylene random block copolymer used in the present invention, T (A4) is 98 ° C. or less, preferably 90 ° C. or less. is there.
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)
If the crystallinity of the component (A2) is not sufficiently lowered, the flexibility and transparency of the propylene-ethylene random block copolymer (A) cannot be secured. Therefore, T (A2) is preferably 45 ° C. or less, Is 40 ° C. or lower.

(7) Molecular Weight (7-1) Regulation of Molecular Weight The propylene-ethylene random block copolymer (A) in the present invention is additionally characterized by a small amount of 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; 371023-1033 (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 value is used for [η] = K × M ^α in the viscosity formula used for conversion to molecular weight.
PS: K = 1.38 × 10 ⁻⁴ α = 0.7
PE: K = 3.92 × 10 ⁻⁴ α = 0.733
PP: K = 1.03 × 10 ⁻⁴ α = 0.78
The measurement conditions for GPC are as follows.
Apparatus: GPC (ALC / GPC 150C) manufactured by WATERS
Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
Column: AD806M / S (3 pieces) manufactured by Showa Denko KK
Mobile phase solvent: 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 random 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 ) Is preferably performed on the CXS component.
Here, the CXS component was prepared by dissolving a propylene-ethylene random 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- The intrinsic viscosity [η] cxs of the CXS component obtained by evaporating xylene 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 random block copolymer used in the present invention does not increase the generation of a component having a molecular weight of 5,000 or less that tends to bleed out, the conventional Ziegler-Natta catalyst is Even if the intrinsic viscosity [η] cxs of the CXS component is in the region of 2 or less, which has been a practical problem due to problems such as blocking and blocking, it can be produced and used without causing any particular deterioration in physical properties. it can.
The propylene-ethylene random block copolymer which does not increase the component having a molecular weight of 5,000 or less while lowering the intrinsic viscosity of the CXS component has characteristics in terms of physical properties such as excellent impact resistance and tear strength. It shows the effect that there are few occurrences of appearance defects called “butsu” and “fish eyes”.

2. Production method of propylene-ethylene random block polymer (A) (1) Metallocene catalyst The method of producing the propylene-ethylene random block copolymer (A) used in the present invention requires the use of a metallocene catalyst. Is.
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 random block copolymer, but in the propylene-ethylene random block copolymer used in the present invention, However, in order to suppress stickiness and bleed-out, it is necessary to polymerize using a metallocene catalyst that can narrow the molecular weight and crystallinity distribution. In the Ziegler-Natta catalyst, the excellent propylene-ethylene random block of the present invention is used. The fact that a copolymer cannot be obtained is also apparent from a comparison between 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 transition metal compounds represented by formula (1) Component (b): At least one selected from the following (b-1) to (b-4) Solid component of seed (b-1) Particulate carrier carrying organoaluminoxy compound (b-2) An ionic compound capable of reacting with component (a) to convert component (a) into a cation or (B-3) Solid acid fine particles (b-4) Ion exchange layered silicate component (c): Organoaluminum compound.

(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-fluoropiphenyl) azurenyl} Zirconium dichloride, dimethylsilylenebis {2-ethyl-4- (4-tert-butyl-3-chlorophenyl) azurenyl} zirconium dichloride, and the like can be given.
A compound in which the silylene group of the compound of these specific examples is replaced with a germylene group and zirconium is replaced with hafnium is also exemplified as a suitable compound.
In addition, since the catalyst component is not an important element of the present invention, it avoids complicated listing and is limited to a representative example, but it is obvious that the effective range of the present invention is not limited thereby. It is.

(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 AIR _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 In producing the component propylene-ethylene random block copolymer (A) of the present invention, the crystalline propylene-ethylene random copolymer component (A1) and the low crystalline or amorphous propylene- It is necessary to sequentially polymerize the ethylene random copolymer component (A2).
In the case of 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 the ethylene content is increased in order to improve these physical properties. Not only does the heat resistance become extremely deteriorated and the production becomes difficult, but it is difficult to satisfy all the required qualities.
Therefore, in the present invention, the propylene-ethylene random block copolymer is a block copolymer obtained by sequentially polymerizing components having different ethylene contents in the first step and the second step. It is necessary to balance.
In addition, since the present invention may use a copolymer having a low molecular weight and easily sticking alone as the component (A2), in order to prevent problems such as adhesion to the reactor, the component (A1) is polymerized. It is desirable to use a method of polymerizing component (A2).
(2-1) Sequential polymerization In producing the propylene-ethylene random block polymer (A) of the present invention, the crystalline propylene-ethylene random copolymer component (A1) and the low crystalline or amorphous propylene- It is necessary to sequentially polymerize the ethylene 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 the component (A1) and the 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 or liquefied propylene, it is desirable to use a gas phase method for the production of the component (A2).
Any process may be used for the production of the crystalline propylene-ethylene random copolymer component (A1), but in the case of producing the component (A1) having relatively low crystallinity, adhesion, etc. In order to avoid this problem, it is desirable to use a vapor phase method.
Therefore, using a continuous method, the crystalline propylene-ethylene random copolymer component (A1) is first polymerized by the bulk method or the gas phase method, and then the low crystalline or amorphous propylene-ethylene random copolymer elastomer is used. It is most desirable to polymerize component (A2) by a gas phase method.

(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 component (A1) is sequentially polymerized in the first step and the component (A2) is sequentially polymerized in the second step, it is desirable to add a polymerization inhibitor to 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. Control Method of Components of Propylene-Ethylene Random Block Copolymer (A) Each component of propylene-ethylene random block copolymer (A) used in the polypropylene film of the present invention is controlled as follows, and the present invention The propylene-ethylene random block copolymer (A) can be produced so as to satisfy the constituent requirements.

(1) About component (A1) About crystalline propylene-ethylene random copolymer component (A1), it is necessary to control ethylene content E (A1) and T (A1).
In the present invention, in order to control E (A1) within a predetermined range, the amount ratio of propylene and ethylene supplied to the polymerization tank in the first step may be appropriately adjusted. The relationship between the supply ratio and the ethylene content in the resulting propylene-ethylene random copolymer varies depending on the type of metallocene catalyst used, but the component (A1) having the ethylene content E (A1) required by adjusting the supply ratio is added. Can be manufactured. For example, when controlling E (A1) to 0.5 to 6 wt%, the supply weight ratio of ethylene to propylene is in the range of 0.001 to 0.3, preferably in the range of 0.005 to 0.2. do it.
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 6 to 18 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 as the ethylene content is increased, T (A2) is decreased as E (A2) is increased as in the case of 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 decrease W (A2), the production amount of the second step may be reduced while maintaining the production amount of the first step, which shortens the residence time of the second step. It can be easily controlled by lowering the polymerization temperature or increasing the amount of the polymerization inhibitor. The reverse is also true.
When actually setting the conditions, it is necessary to consider the activity decay. That is, in the range of the ethylene 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 random block copolymer 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) is 18 wt% or less, 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 amorphous copolymer component (A2) is within an appropriate range. It is possible to obtain a polymer having a predetermined [E] gap by setting the supply weight ratio of ethylene to propylene during the polymerization of component (A2).
The Tg of the block copolymer that does not take a phase separation structure as in the present invention is the ethylene content E (A1) in the component (A1), the ethylene content E (A2) in the component (A2), and It is affected by the ratio of both components. In the present invention, the amount of the component (A2) is 15 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, whereas in the block copolymer component (A) of the present invention, the component (A1) has crystallinity and relatively few amorphous parts, This is because the component (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 random block copolymer (A) of the present invention, a crystalline copolymer component (A1) and a low crystalline or amorphous material are used to maintain transparency. Component elastomer (A2) must be compatible, viscosity (η) A1 of component (A1), viscosity [η] A2 of component (A2), propylene-ethylene random block Between the viscosity [η] W of the entire copolymer (A), the apparent viscosity mixing rule is generally established. That is,
Log [η] W = {W (A1) × Log [η] A1 + W (A2) × Log [η] A2} / 100
Is generally established. In general, there is a certain correlation between MFR and [η], so 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 component (A1) is, the closer T (A4) is to T (A1) (lower). ), Controlling T (A4) to be low is nothing other than controlling the crystallinity distribution of component (A1) and component (A2) narrowly.
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 random block copolymer to those having desirable physical properties, the component (A1) and the component (A2) need to have different specific polymer compositions. That is, in the first step and the second step, it is necessary to keep the polymerization conditions corresponding to the respective polymer compositions, particularly the monomer gas composition, at different specific values. Therefore, when the crystallinity distribution of the component (A2) is wide in the adopted process, the transfer step is adjusted so that the specific monomer gas mixture corresponding to the first step is not brought into the second step from the first step. It is necessary to devise such as. Specifically, the crystallinity distribution of the component (A2) can be narrowed by increasing the purge amount in the transfer step, or by diluting or substituting with an inert gas such as nitrogen. That is, 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 changed with an inert gas such as nitrogen in the transfer step. By completely substituting, 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 random 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 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). Additional ingredients (additives)
In the propylene-ethylene random block copolymer (A) used in the present invention, in addition to the above (A), properties such as transparency are further enhanced and other properties such as oxidation resistance are added. In addition, an additional component may be added as an optional component within a range that does not significantly impair the effects of the present invention.
(1) Antiblocking agent The antiblocking agent used for the propylene-type resin film of this invention is 1-7 micrometers in average particle diameter, Preferably it is 1-5 micrometers, More preferably, it is 1-4 micrometers. 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 property are remarkably inferior. 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.
Moreover, as an organic type, polymethyl methacrylate, polymethylsilyltosesquioxane (silicone), polyamide, polytetrafluoroethylene, epoxy resin, polyester resin, benzoguanamine / formaldehyde (urea resin), phenol resin, etc. are used. be able to.
In particular, synthetic silica and polymethyl methacrylate are preferable from the balance of dispersibility, transparency, blocking resistance, and scratch resistance.
The anti-blocking agent may be surface-treated, and as the surface treating agent, surfactant, metal soap, acrylic acid, oxalic acid, citric acid, tartaric acid and other organic acids, higher alcohols, esters, Condensed phosphates such as silicone, fluorine resin, silane coupling agent, sodium hexametaphosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium trimetaphosphate, etc. can be used, especially those treated with citric acid among organic acids Is preferred. The treatment method is not particularly limited, and a known method such as surface spraying or dipping 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 antiblocking agents can be used singly or in combination of two or more in a range that does not impair the effects of the present object.
The compounding amount of the antiblocking agent 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 random block copolymer of the present invention. When the blending amount is less than the above range, the antiblocking 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 Examples of the fatty acid amide 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, hydroxystearic acid amide and the like as saturated fatty acid monoamides.
Examples of the unsaturated fatty acid monoamide include oleic acid amide, erucic acid amide, ricinoleic acid amide and the like.
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 the unsaturated fatty acid bisamide include ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N, N′-dioleoyl adipic acid amide, N, N′-dioleyl sepasin 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 random block copolymer of the present invention. Is 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.

(3) Other additives In order to further enhance properties such as transparency and to add other properties such as oxidation resistance to the propylene-ethylene random block copolymer (A) used in the present invention. In addition, an additional component may be added as an optional component 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 compounding quantity of these additives is 0.0001-3 weight part with respect to 100 weight part of propylene-ethylene random block copolymers of this invention, Preferably it is 0.001-1 weight part.
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 compounding quantity of an elastomer is 1-30 weight part with respect to 100 weight part of propylene-ethylene random block copolymers of this invention, Preferably it is 5-20 weight part.

(3-1) 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- Sorbitol compounds such as di (p-methylbenzylidene) rubitol, hydroxy-di (t-butylbenzoate aluminum), 2,2-methylene-bis (4,6-di-t-butylphenyl) phosphoric acid and carbon atoms of 8 to 20 aliphatic monocarboxylic acid lithium salt mixture (trade name NA21 manufactured by Asahi Denka Co., Ltd.), polyethylene resin and the like.
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-hydroxypentyl) -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-g 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 Phosphite can be mentioned.
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.

(3-2) Elastomer Material 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 0.86 to 0.90 g / cm ³ . The melt flow rate (MFR) at 190 ° C. and a load of 2.16 kg is 0.01 to 100 g / 10 min, preferably 0.05 to 50 g / 10 min. 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.

(4) Addition method These additional components can be directly added to the propylene-ethylene random block copolymer (A) used in the present invention obtained by polymerization and melt kneaded for use. It 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.

5. Film (1) T-die molding The propylene-based resin film of the present invention is obtained by a T-die molding method. T-die molding is widely used for the production of polyolefin resin films. The raw material is melted by an extruder, the molten resin is extruded flatly through a T-die, and the air supplied from a cooling roll, blower, etc. It is a method of forming a film by spraying the outer surface and solidifying by cooling and then taking it out.
As the T-die molding machine used in the present invention, any known type can be used. However, a machine including the elements described later and capable of taking specific molding conditions is preferable.

(1-1) Extruder Various known extruders can be used as the extruder, but it is preferable to use a single screw extruder in order to keep the resin temperature low and obtain stable discharge. As a screw shape used for a single screw extruder, a type generally used for extrusion of polyolefin can be widely used, but unmelted material such as a barrier type screw or a Maddock type mixing is generated in order to stabilize plasticization. A difficult shape is preferred. Further, even if the set temperature is low, if the heat generated by shearing is too large, there is a concern that the odor will be worsened, so the groove depth of the metering part is preferably 1 mm or more, and preferably about 2 mm. is there. 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.

(1-2) Dies Various known T dice used for T die molding can be used as the dice, but generally T dice used for single layer film molding are straight type T dice or coat hangers. Type T dice etc. are mentioned. Examples of the die used in the co-extrusion molding include a multi-manifold type multi-layer T die, a feed block type multi-layer T die, a multi-manifold, and a feed block type multi-layer T die.

(1-3) Cooling roll There are no particular limitations on the cooling roll, such as a mirror surface roll or a semi-matt roll, and various known cooling rolls can be used. It is advantageous for suppressing poor adhesion such as fish eyes.
Further, the surface roughness of the semi-matt roll is preferably about 2 to 4 μm, and if the surface roughness is large, the trace of the cooling roll is transferred to the film and the transparency is deteriorated. Furthermore, the cooling roll may be installed not only in one step but also in two or more steps. Further, it is more effective to suppress the bleed out of the additive by providing a sweeper roll in combination with the cooling roll. Further, when the molten resin comes into contact with the cooling roll, in order to suppress the occurrence of draw resonance (uneven thickness unevenness in the molten resin flow (MD) direction) due to insufficient cooling of the molten resin, in the direction of pressing the film against the cooling roll. Blow air supplied from a blower or the like. As a device for blowing air, various known devices used for T-die molding represented by an air knife can be used. In recent years, speeding up of molding has been demanded to improve productivity. However, vacuum-type air chambers that prevent the air from being caught between the roll and the film and improve film formation stability and the film edge Air blowing with an air nozzle that stabilizes shaking, an edge type pinning method using a discharge method, and the like can also be suitably used.

(1-4) Molding temperature Although it does not specifically limit as a temperature which shape | molds the T-die molded film in this invention, It is more than the melting peak temperature obtained by the DSC measurement of a propylene-ethylene block copolymer (A). It is preferable to take a range of less than 300 ° C. Usually, propylene-based resins have a higher melting point than polyethylene-based resins and are molded at a relatively high temperature. On the other hand, when the molding temperature is high, the thermal deterioration of the polymer and additives and the 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 described later, a stable extrusion can be obtained even when the molding temperature is lowered, so that the odor is remarkably improved. That is, when the extrusion temperature is 300 ° C. or higher, the odor is deteriorated even if a raw material with a low molecular weight component or an oligomer is used, so that a film with low odor which is one of the objects of the present invention is obtained. The molding temperature is preferably less than 300 ° C. More preferably, it is less than 260 degreeC, More preferably, it is less than 240 degreeC.
On the other hand, at temperatures below the melting point of the propylene-ethylene block copolymer (A), it cannot be sufficiently plasticized and stable extrusion is impossible, and therefore, by 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 a set temperature in each area from the cylinder part excluding the feed part of the extruder and from the extruder to the die outlet.

(1-5) 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.

(1-6) Film-forming speed The film-forming speed is determined by the film thickness and width and the amount of extrusion, and can be adjusted within a range where film-forming stability can be maintained. Generally, in T-die molding, it is 1 to 800 m / min, preferably 5 to 500 m / min, more preferably 10 to 300 m / min.

(2) Film thickness In the propylene-based resin film and the propylene-based resin laminated film of the present invention, the thickness of the film is not particularly limited, but the thickness when used alone is 10 to 500 μm. The thickness is preferably 10 to 250 μm, more preferably 15 to 100 μm. Moreover, when shape | molding and using as a propylene-type resin laminated | multilayer film, the thickness of the film layer of the propylene-ethylene block copolymer (A) of this invention is 10 of the whole laminated film with respect to the thickness of the whole laminated film. Used in the range of% to 90%. When used in a laminated film, the thickness of the film layer of the present invention is 1 to 500 μm, preferably 1 to 250 μm, and more preferably 1 to 100 μm.

(3) Layer constitution of propylene-based resin laminated film The layer constitution of the propylene-based resin laminated film of the present invention is any layer as long as it contains at least one film layer of the propylene-ethylene block copolymer (A) of the present invention. Can also be used. 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, or both surface layers.
Further, the propylene-based resin film and the propylene-based resin laminated film of the present invention may be used alone or used for further laminating (laminating) on various base materials to impart this function to the base materials. May be.
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. 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) Post-treatment The surface treatment usually employed industrially can be applied to the propylene-based resin film obtained in the present invention. 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.

6). Applications The propylene-based resin film obtained in the present invention has high impact resistance, no whiteness, clear transparency, and less bleed-out than the polypropylene film obtained by the conventional technology. The material is extremely high in commercial value.
Although it does not specifically limit as a use, It uses suitably for packaging uses, such as a foodstuff, clothing, a medical treatment, a medicine, a stationery, miscellaneous goods, an industrial material, and an industrial use.
(1) Examples of suitable uses Since the propylene-based resin film of the present invention has moderate flexibility and excellent hygiene, it is suitably used for food packaging applications, medical and pharmaceutical packaging applications. Furthermore, since it has heat resistance, it is also suitably used for heat-sterilized packaging bags.
In addition, because it is environmentally friendly and excellent in transparency and bending whitening resistance, surface protection films for metal plates, decorative plywood and synthetic resin plates as well as various interior and exterior building materials, joinery, home appliances, It is suitable for use as a surface protective film for decorative sheets used in office equipment and the like.

(2) Protective film The protective film of the present invention only needs to contain at least one single-layer film or laminated film obtained in the present invention. For example, the propylene-based resin for adhesion to a metal substrate layer A film adhesive layer or the like may be laminated, or an easy-adhesion layer may be laminated for adhesion to a substrate layer other than metal, for example, a polyolefin-based film. In order to impart scratch resistance, a clear layer or the like may be laminated on the propylene-based resin film.
The pressure-sensitive adhesive used as the pressure-sensitive adhesive layer is not particularly limited, and examples thereof include acrylic resins, styrene-isobutylene-styrene copolymers, styrene-butylene-styrene copolymers, styrene-ethylene-butylene-styrene copolymers, polyisobutylene. A general resin made of a resin, a natural rubber resin, a styrene-butadiene copolymer, a styrene-isoprene copolymer, or the like can be used. The method for forming the pressure-sensitive adhesive layer is not particularly limited, and examples thereof include a melt coating method and a method in which the molding material and the pressure-sensitive adhesive are co-extruded at the time of producing a film. Appropriate selection may be made according to the conditions. Although the thickness of an adhesion layer is not specifically limited, Usually, it is 1-100 micrometers, Preferably it is the range of 3-50 micrometers.
Acrylic resin, vinyl chloride-vinyl acetate copolymer, polyester resin, urethane resin, chlorinated polypropylene, and chlorinated polyethylene are used as the easy adhesion layer (also referred to as primer layer or anchor layer). Resin is desirable. Although the thickness of an easily bonding layer is not specifically limited, Usually, it is the range of 0.1-5 micrometers.
The material for forming the clear layer is not particularly limited. For example, a general coating agent mainly composed of a melamine resin, a fluorine resin, a polyurethane resin, a polysiloxane resin, or a modified resin thereof may be used. it can. There is no restriction | limiting in particular as the application | coating method of these coating agents, A conventional method can be used as it is. That is, a roll coater, a reverse roll coater, an air knife coater, a blade coater, a spray or the like can be used. Although the thickness of a clear layer is not specifically limited, Usually, sufficient effect is expressed in the range of 1-50 micrometers, Preferably it is 3-20 micrometers.

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

[Methods for measuring physical properties of propylene-ethylene random block copolymer (A)]
1) Melt flow rate (MFR)
According to JIS K7210A 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 processing glass beads Heating method: Aluminum heat block Cooling method: Peltier element (Peltier element cooling is water-cooled)
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 (thickness 2 mm, width 30 mm, length 90 mm)

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 0042.

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 0033-0037.
9) Heat resistance Using the test piece used for the measurement of solid viscoelasticity, the heat resistance of the block copolymer was evaluated under the following conditions.
Standard number: JIS K7206 (Conforms to the 50 method except that the load is 250 g)
Measuring machine: Fully automatic HDT measuring machine (manufactured by Toyo Seiki)
Shape of the test piece: 2 mm thick 25 mm × 25 mm Two flat plates are prepared. Test piece preparation: Injection molded flat plate is punched into the above shape. Condition: Room temperature is 23.degree. Leave as it is (no annealing)
Test weight: 250g
Temperature increase rate: 50 ° C./hour Number of test pieces: 3

[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, with 2.80 mg (0.3 mM) of (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azulenyl}] zirconium mixed in 870 ml of 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 remaining 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 46 ° C. under reduced pressure. A prepolymerized catalyst containing 2.0 g of re-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 / hour, 4.2 kg / hour, and 21.2 g / hour, 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 propylene-ethylene random copolymer obtained in the first step 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.
When the propylene-ethylene random block copolymer thus obtained was analyzed, the activity was 8.7 kg / g-catalyst, the BD was 0.41 g / cc, the MFR was 7.0 g / 10 min, and the ethylene content was 8. It was 7 wt%.

(Granulation)
The following antioxidant, neutralizing agent, anti-blocking agent and lubricant were added to the blender to the block copolymer powder obtained in Polymerization Production Example A-1, 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 Neutralizer: calcium stearate (Nippon Yushi Co., Ltd.) Co., Ltd., calcium stearate G) 0.05 parts by weight Antiblocking agent: Synthetic silica (manufactured by Fuji Silysia Co., Ltd., Silicia 430, particle size 2 μm) 0.20 parts by weight Lubricant: erucic acid amide (Nippon Seika ( Co., Ltd., Neutron S), 0.10 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, Melted and 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 diameter of about 2 mm and a length of about 3 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 the requirements as component (A).
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]
The propylene-ethylene random block copolymer obtained in Polymerization Production Example A-1 is not the antiblocking agent (Silicia 430) used in Production Example PP-1, but Silicia 770 (manufactured by Fuji Silysia Ltd., synthetic silica, PP-1B raw material pellets were obtained by the same additive formulation and granulation conditions as in Production Example PP-1 except that the antiblocking agent had a particle size of 6 μm. Various analysis results were the same as those of Production Example PP-1.
[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 random 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 Examples PP-2 to 12]
[Polymerization Production Examples A-2 to 12]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene (random) block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
From the obtained polymer powder, PP-2 to 12 raw material pellets were obtained 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, and production of a propylene-ethylene random copolymer was carried out. 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 Examples PP-14-15]
[Polymerization Production Examples A-14 to 15]
In the same manner as in Polymerization Production Example A-1, the polymerization conditions were changed to produce a propylene-ethylene random block copolymer. The polymerization conditions and polymerization results are shown in Table 3.
PP-14-15 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 fully nitrogen-substituted flask, and then 2.6 moles of MgCl ₂ and 5.2 moles 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. To this, 100 g of the n-heptane slurry of the solid catalyst component (A) prepared above was introduced 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 prepolymerized catalyst thus obtained 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 random block copolymer was produced in the same manner as described above. 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 random block copolymer. The polymerization conditions and 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-18]
In addition to the same additives as in Production Example PP-1, the propylene-ethylene random block copolymer obtained in Polymerization Production Example A-17 was used as an organic peroxide (2,5-dimethyl-2,5-bis). (Tertiary butyl peroxy) 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)
The obtained PP-1 pellets were an extruder of 35 mm in diameter and L / D = 24, a coat hanger type single-layer T die having a width of 300 mm and a lip width of 1 mm, an air knife, an air nozzle, and a semi-matt type having a surface roughness of 2 μm. Using a T-die film manufacturing apparatus equipped with a cooling roll, a molding process was performed at an extrusion resin temperature of 230 ° C., a cooling roll temperature of 35 ° C., and a film take-up speed of 20 m / min, and a corona treatment of 42 mN / m was applied to one side. An unstretched propylene-based resin film having a thickness of 25 μm was obtained. The physical properties of the obtained film were evaluated for the following items. The results are shown in Table 5.

(Evaluation of the physical properties)
1) HAZE
The obtained film was conditioned for 24 hours under an atmosphere of 23 ° C. and 50% RH, and then measured with a haze meter in accordance with 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 for 2 hours in an atmosphere of 23 ° C. and 50% RH. -Measure HAZE 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) Blocking resistance A sample film of 2 cm (width) x 15 cm (length) was taken from the obtained film, and the corona treatment inner portions were overlapped over a length of 5 cm (contact area 10 cm ² ), 0.5 N / cm ² After conditioning for 24 hours under an atmosphere of 40 ° C. under load, after removing the load and conditioning for 2 hours under an atmosphere of 23 ° C. and 50% RH, 500 mm / min using a shopper type tensile tester The force required for shear peeling of the sample was determined at a speed (unit: N / 10 cm ² ). It means that blocking resistance is so good that this value is small.

4) Slip (slip)
The resulting film was conditioned for 24 hours in an atmosphere at a temperature of 23 ° C. and 50% RH, and then the friction between the corona-treated surfaces of the film was evaluated by a static friction coefficient by a slip tester method in accordance with ASTM-D1894. . The smaller this value, the better the slipperiness.

5) Punching impact strength After the obtained film was allowed to stand in an atmosphere of 23 ° C. for 24 hours to adjust the state, each atmosphere was adjusted using a film impact tester manufactured by Toyo Seiki Seisakusho in accordance with JIS-P8134. The measurement was performed below (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) Heat sealability (HS)
Using a heat seal bar of width 5 mm × length 200 mm, the non-processed surfaces of the obtained film were melt-extruded in a film under conditions of a heat seal pressure of 0.2 MPa and a heat seal time of 1 second at each temperature setting. A sample having a width of 15 mm was taken from the sample sealed so as to be perpendicular to (MD), and pulled away in the MD direction at a tensile speed of 500 mm / min using a shopper type tester, and the load was read. The heat sealability was evaluated at the seal temperature when the load reached 3 N (unit: ° C.). It means that low temperature heat-sealing property is excellent, so that this value is small.

9) Smell A film sample obtained so that the volume of the Erlenmeyer flask becomes about 1/2 of the volume of the Erlenmeyer flask is put into a 300 ml Erlenmeyer flask with a stopper, stoppered, heated for 2 hours in a constant temperature bath at 80 ° C. and taken out. Odor sensory evaluation was performed within 10 minutes according to the following criteria.
○: Odorless or finally odor is felt Δ: Slightly odor ×: Smelly xx ×: Smells violently 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 PP-1C having different additive blends from PP-1 were used as raw materials. The evaluation results are shown in Table 5.
[Examples 4 to 9]
A film was formed and evaluated in the same manner as in Example 1 except that PP-2 to 7 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-8 was used as a raw material. The evaluation results are shown in Table 5.
[Comparative Example-2]
Except for using PP-9 as a raw material, film formation was carried out in the same manner as in Example 1. However, the film formation stability was poor, the film thickness varied, and an evaluation sample could not be obtained.
[Comparative Examples-3 to 11]
Except having changed PP-1 of Example-1 into PP-10-18, film shaping was implemented and evaluated similarly to Example-1. The evaluation results are shown in Table 5.

[Example-10]
The obtained PP-2 pellets were used as a sealant layer and an intermediate layer, as well as a polypropylene random copolymer (trade name WINTEC: WMB3, manufactured by Nippon Polypro Co., Ltd.) having a melting peak temperature of 142 ° C. and an MFR of 8.0 g / 10 min. PP-19 pellets obtained from the granulated powder by the same additive formulation and granulation conditions as in Production Example PP-1 were used as the surface layer, and the thickness ratio of the surface layer / intermediate layer / sealant layer was 1/4/1. Thus, three extruders each having three layers (surface layer: L / D = 25, caliber 20 mmψ / intermediate layer: L / D = 24, caliber 35 mmψ / sealant layer: L / D = 25, caliber 20 mmψ) Machine), a 300 mm wide multi-manifold three-layer T die, a semi-matt type cooling roll (diameter 300 mmφ) with a surface roughness of 2 μm, and an air knife. Using the three-type three-layer T-die molding method (installed in an air gap of 50 mm), the melt was melt-extruded so that the sealant layer would contact the cooling roll at an extrusion resin temperature of 230 ° C. The film was drawn at a film forming speed of 8 m / min at 0 ° C. to obtain an unstretched propylene-based resin laminated film having a thickness of 60 μm. The surface layer was subjected to corona treatment. The corona treatment was carried out so that the wetting tension according to JIS K6768 was 42 mN / m immediately after molding. Furthermore, a biaxially stretched nylon film having a thickness of 15 μm is used as a base material, and a biaxially stretched nylon film is dry laminated on the surface layer subjected to corona treatment of the propylene resin laminated film through an ester adhesive. To obtain a laminated laminate. The laminate was aged for 6 days in an atmosphere at 45 ° C., and the physical properties of the obtained film were evaluated for the following items. The results are shown in Table 6.

[Physical property evaluation before and after heat sterilization treatment of laminated laminate]
1) Evaluation before heat sterilization treatment Laminate laminates obtained in the examples were cut into two pieces with a size of 120 mm in the MD direction and 100 mm in the TD direction, the MD direction and the TD direction were matched, and the base film (biaxial stretching) After superimposing the nylon film so that it faces outward, as shown in FIG. 4, two sides in the MD direction and one side in the TD direction are thermocompression bonded with a width of 10 mm (conditions: 200 ° C., 0.2 MPa / cm ^2). 1.0 seconds) to obtain a laminated bag for packaging. This laminated bag for packaging was used as a product before heat sterilization treatment. However, in FIG. 4, 1 and 2 are laminated laminates, 3 is a heat fusion part (heat seal part), and 4 is a test piece for heat seal strength measurement.
Haze before heat sterilization (unit:%): Measured according to JIS K7105-1981.
Heat seal strength before heat sterilization treatment (unit: N): Measured by the following method in accordance with JIS Z1707-1995.
As shown in FIG. 4, the test piece 4 having a length of 100 mm and a width of 15 mm in the TD direction is cut out from the laminated bag for packaging before heat sterilization so as to include the thermocompression bonding portion in the TD direction, As shown in FIG. 5, the test piece 4 was peeled off at a tensile speed of 500 mm / min using a shopper type tensile tester to obtain the strength.
2) Evaluation after heat sterilization treatment The packaging bag obtained above was then filled with 20 ml of tap water, subjected to heat sterilization treatment conditions at 120 ° C. for 30 minutes, and physical properties were removed after removing tap water. evaluated. Haze after heat sterilization treatment (unit:%): Measured according to JIS K7105-1981.
Heat seal strength after heat sterilization treatment (unit: N): Measured by the following method according to JIS Z1707-1995.
As shown in FIG. 4, the test piece 4 having a length of 100 mm and a width of 15 mm in the TD direction is cut out from the laminated bag for packaging after the heat sterilization process so as to include the thermocompression bonding portion in the TD direction. As shown in FIG. 5, the test piece 4 was subjected to heat seal strength using a shopper type tensile tester at a tensile speed of 500 mm / min.
The smaller the difference in haze before and after heat sterilization, the smaller the effect on the treatment and the better. The smaller the decrease in heat seal strength before and after heat sterilization, the smaller the effect on the treatment and the better.
3) Fusion property after heat sterilization (heat resistance)
The laminated bag obtained above was subjected to heat sterilization treatment conditions at 120 ° C. for 30 minutes without filling the contents, and the physical properties were evaluated. The fusing property between the inner untreated surfaces of the packaging laminated bag after the heat sterilization treatment was visually evaluated in four stages.
◎: Very good without fusing ○: Some fusing is good, but △: Fusing is seen slightly poor ×: Fusing is bad, and the film is stuck in a plate shape and bad

[Comparative Examples-12 to 17]
Except having changed PP-2 of Example-10 into PP-11, PP-13-16, and PP-18, film forming was performed and evaluated in the same manner as in Example-10. The evaluation results are shown in Table 6.

[Example-14]
PP-1 pellets, 35 mm diameter, L / D = 24 extruder, 300 mm wide, coat hanger type single layer T die with 1 mm lip width, air knife, air nozzle, and semi-matt type cooling roll with surface roughness of 2 μm Using a T-die method film production apparatus equipped with a thickness of extrusion resin temperature 230 ° C., cooling roll temperature 35 ° C., film take-up speed 5 m / min, and corona treatment of 42 mN / m on both sides. An unstretched propylene-based resin film having a thickness of 100 μm was obtained.
A two-component curable urethane resin was applied to one side of the obtained film as a clear layer to a thickness of 5 μm and dried. Table 7 shows the HAZE of the obtained film.
Furthermore, as a base material, a non-stretched polypropylene film with a black solid print having a thickness of 100 μm is used, and the surface opposite to the clear layer of the propylene-based resin laminated film is mediated by a urethane two-component reactive adhesive. Further, the printed surface side of the unstretched polypropylene film was bonded by dry laminating to obtain a laminated laminate. The physical properties of the obtained laminate were evaluated for the following items. The results are shown in Table 7.

1) Evaluation of normal temperature bending whitening property The surface protective film bonded to the base material layer obtained in the example was folded in two in a 23 ° C. atmosphere with a 10 cm × 10 cm sheet and the clear layer side as a mountain side. did. The crease was rubbed 10 times on a glass plate with a metal plate weighing 2 kg. After returning the fold to a flat surface, it was observed at a magnification of 20 times using a polarizing microscope, and the state of the fold was judged according to the following criteria to make a folding whitening evaluation.
○: The crease is not whitened. △: The crease is slightly whitened. ×: The crease is markedly whitened. The film was folded in two into a 10 cm × 10 cm sheet with the clear layer side as the mountain side in an atmosphere of 5 ° C. The crease was rubbed 10 times on a glass plate with a metal plate weighing 2 kg. After returning the fold to a flat surface, it was observed at a magnification of 20 times using a polarizing microscope, and the state of the fold was judged according to the following criteria to make a folding whitening evaluation.
○: The crease is not whitened △: The crease is slightly whitened ×: The crease is markedly whitened

[Example-12]
Except having changed PP-1 of Example-11 into PP-3, film forming was performed and evaluated in the same manner as Example-11. Table 7 shows the evaluation results.
[Comparative Examples-18 to 22]
Except having changed PP-1 of Example-11 into PP-18-22, film shaping was implemented and evaluated similarly to Example-11. Table 7 shows the evaluation results.

[Consideration by contrast between Example and Comparative Example]
In consideration of each of the above Examples and Comparative Examples in contrast, in the propylene resin film using the specific propylene-ethylene random block copolymer of the present invention that satisfies the respective regulations in the configuration of the present invention. It is clear that the transparency and impact resistance are very excellent, the product is not blocking, the bleed-out is suppressed, and the bending whitening resistance is improved. It is understood that each provision is reasonable and confirmed by experimental data.

Specifically, in Comparative Example-1, since the MFR of the propylene-ethylene random block copolymer (A) was too low, the film surface was rough and the appearance was extremely deteriorated. In Comparative Example-2, since the MFR of the propylene-ethylene random block copolymer (A) was too high, draw resonance occurred at the time of molding, and a film with an unstable and uniform thickness could not be obtained. . Therefore, the physical properties could not be evaluated.
In Comparative Example-3, since the component (A1) of the propylene-ethylene block copolymer (A) is a propylene homopolymer, the flexibility is poor, impact resistance and tear strength are weak, and the heat seal temperature is low. High and low temperature heat sealability is poor. In Comparative Examples-4 and 6, the case where the propylene-ethylene random copolymer alone or the component (A2) is too small was shown. At this time, the flexibility is insufficient and the impact strength and tear strength are poor. In Comparative Example-5, the case where the ethylene content in the component (A2) is small was shown. At this time, flexibility and impact resistance are insufficient. In Comparative Example-7, the case where tan δ in the solid viscoelasticity measurement did not have a single peak but had a phase separation structure was shown. In this case, the transparency is significantly deteriorated. In comparative example-8, the case where there were too many components (A2) was shown. At this time, the blocking of the film is deteriorated and the heat resistance is also inferior. In Comparative Example-9, a propylene-ethylene block copolymer polymerized using a Ziegler-Natta catalyst was used, but the transparency was inferior and the amount of the low molecular weight component W (M ≦ 5000) was large. Therefore, blocking, stickiness and bleed out are remarkable. In Comparative Example-10, the case where a Ziegler-Natta catalyst was used as in Comparative Example-9 and the overall molecular weight was increased to reduce the low molecular weight component in order to improve stickiness and bleedout was shown. At this time, the surface appearance deteriorates and a film having excellent transparency cannot be obtained. In Comparative Example-11, in order to improve the appearance defect of Comparative Example-10, the molecular weight is lowered by adding an organic peroxide to PP-17 used in Comparative Example-9 at the time of granulation, and the amount of low molecular weight components is reduced. An attempt was made to improve fluidity while suppressing. However, as a result, the improvement of blocking was not so much, the film appearance was improved, but the transparency was not excellent, and the odor was greatly deteriorated by the use of organic peroxide.
Compared to the propylene-based resin film comprising the propylene-ethylene random block copolymer of the present invention, which has excellent properties such as transparency, flexibility, and impact resistance, less blocking and bleed out, and excellent odor. And in each comparative example, quality is inferior and the characteristic of the propylene-type resin film of this invention is made to stand out.

In Example-10 and Comparative Examples-12-17, the evaluation at the time of laminating and using as a sealant was shown. In Example-10, the transparency is good, the heat sealing temperature is low, and no fusion occurs even after heating.
In Comparative Example-12, since the component (A1) of the propylene-ethylene block copolymer (A) is a propylene homopolymer, the heat seal temperature is high, the low temperature heat seal property is inferior, and the heat seal strength is insufficient. To do. In Comparative Example-13, a propylene-ethylene random copolymer not containing the component (A2) was used. At this time, since the impact resistance was low, the heat resistance deteriorated when the melting point was lowered, and problems such as deterioration in transparency and fusion occurred after heat sterilization. In Comparative Example-14, the case where tan δ in the solid viscoelasticity measurement did not have a single peak but had a phase separation structure was shown. In this case, the transparency is significantly deteriorated. In comparative example-15, the case where there were too many components (A2) was shown. The bag deformed greatly during heat sterilization due to low heat resistance. In Comparative Examples 16 and 17, a propylene-ethylene random block copolymer polymerized using a Ziegler-Natta system was used, but there were many bleedouts after heat sterilization treatment, resulting in a large decrease in transparency, Blocking is bad.

In Examples-11, 12 and Comparative Examples-18-22, evaluation as a surface protective film was performed. In Examples 11 and 12, transparency and bending whitening resistance are good.
In Comparative Example-18, since the component (A1) of the propylene-ethylene block copolymer (A) is a propylene homopolymer, the bending whitening resistance is poor. In Comparative Example-19, since the component (A2) of the propylene-ethylene block copolymer (A) is small and not flexible, the bending whitening resistance is inferior. In Comparative Example-20, since the used raw material is a normal propylene-ethylene random copolymer and does not contain the component (A2) and is not flexible, the bending whitening resistance is poor. In Comparative Example-21, a propylene-ethylene random block copolymer polymerized using a Ziegler-Natta catalyst was used, but the transparency deteriorates and the bending whitening resistance is inferior. In Comparative Example-22, PP-17 used in Comparative Example-20 was added with an organic peroxide during granulation to lower the molecular weight and improve the fluidity while suppressing the amount of low molecular weight components. Although the folding whitening property has been improved to some extent, the transparency is poor as in Comparative Example 19. Also, the odor worsened.

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. It is explanatory drawing of test piece collection for measuring the heat seal intensity | strength of the laminated body for heat sterilization processing packaging. It is explanatory drawing of the test piece for measuring the heat seal intensity | strength of the laminated body for heat sterilization processing packaging.

Explanation of symbols

1; Heat sterilization packaging bag material 2; Heat sterilization packaging bag material 3; Heat seal part 4; Test piece for heat seal measurement

Claims (9)

A propylene-based resin film formed by a T-die molding method using a propylene-ethylene random block copolymer (A) satisfying the following conditions (Ai) to (A-iv) as a raw material.
(Ai) Propylene-ethylene random copolymer in which the ethylene content of the component (A1) obtained in the first step is in the range of 0.5 to 6 wt% using the metallocene-based catalyst, the proportion in the whole (A) 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 ratio in the whole (A) is in the range of 70 to 15 wt%. (A-ii) Obtained as a plot of elution amount (dWt% / dT) against temperature by temperature-elevated elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using an o-dichlorobenzene solvent. In the TREF elution curve, 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. T (A2) is not observed, and the temperature T (A4) at which 99 wt% of the total propylene-ethylene block copolymer elutes is 98 ° C. or less (A-iii) Melt flow rate (MFR; 2.16 kg 230 ° C) is in the range of 1 to 50 g / 10 min. (A-iv) In the temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA), the tan δ curve has a single peak below 0 ° C. Having The propylene-based resin film according to claim 1, wherein the propylene-ethylene random block copolymer (A) satisfies the following conditions (A-v).
(Av) The component amount W (Mw ≦ 5,000) of 5,000 or less in the molecular weight of the block copolymer obtained by gel permeation chromatography (GPC) measurement is 0. 8wt% or less The propylene-based copolymer according to any one of claims 1 to 3, wherein the propylene-ethylene random block copolymer (A) satisfies the following conditions (A-vi) to (A-vii): Resin film.
(A-vi) The propylene-ethylene random copolymer in which the ethylene content of the component (A1) obtained in the first step is in the range of 1.5 to 6 wt%, and the proportion in the whole (A) is in the range of 30 to 70 wt%. The component (A2) obtained in the second step contains 8 to 16 wt% more ethylene than (A1), and the ratio in the whole (A) is in the range of 70 to 30 wt%.
(A-vii) TREF obtained as a plot of elution amount (dWt% / dT) against temperature by temperature-elevated elution fractionation method (TREF) in the temperature range of −15 ° C. to 140 ° C. using o-dichlorobenzene solvent In the elution curve, the peak T (A1) observed on the high temperature side is in the range of 60 ° C. to 88 ° C., the peak T (A2) observed on the low temperature side is 40 ° C. or lower, or the peak T (A2) Is not observed, and the temperature T (A4) at which 99 wt% of the total propylene-ethylene block copolymer elutes is 90 ° C. or lower. The propylene-based resin film according to any one of claims 1 to 4, wherein the propylene-ethylene random block copolymer (A) satisfies the following condition (A-ix).
(A-viii) The intrinsic viscosity [η] cxs of the 23 ° C. xylene soluble component measured in decalin at 135 ° C. is in the range of 1 to 2 (dl / g).   The antiblocking agent having an average particle diameter of 1 to 7 µm is blended in an amount of 0.01 to 1.0 parts by weight with respect to 100 parts by weight of the propylene-ethylene random block copolymer (A). The propylene-type resin film described in any one of Claims 1-4.   The fatty acid amide is contained in an amount of 0.01 to 1.0 part by weight with respect to 100 parts by weight of the propylene-ethylene random block copolymer (A), according to any one of claims 1 to 5. Propylene-based resin film.   A propylene-based resin laminate film comprising at least one layer composed of the propylene-based resin film according to any one of claims 1 to 6 and formed using a T-die coextrusion molding method.   A food packaging bag material or a medical packaging comprising the propylene-based resin film or the propylene-based resin laminated film according to any one of claims 1 to 7, and being used after being heat-sterilized. Bag material.   A film for surface protection using the propylene-based resin film or the propylene-based resin laminated film according to any one of claims 1 to 7.

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