JP2016011380A - Polypropylene-based resin composition for high rigidity film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene-based resin composition for high rigidity film that is excellent in balance between transparency and rigidity.SOLUTION: A polypropylene-based resin composition contains 0.01 to 0.5 pts.wt. of a nucleating agent (c) comprising a compound represented by the formula (1) in 100 pts.wt. of a resin component comprising a component (a) shown below by 60 to 90 wt.% and a component (b) by 10 to 40 wt.%. The component (a): propylene-α-olefin random copolymer, the component (b): alicyclic hydrocarbon resin selected from the group consisting of petroleum resin, terpene resin, rosin-based resin, coumarone-indene resin and hydrogenated derivatives thereof.

Description

  The present invention relates to a polypropylene-based resin composition for high-rigidity films, and specifically relates to a polypropylene-based resin composition for high-rigidity films having an excellent balance between rigidity and transparency.

Conventionally, polypropylene films have been widely used for various packaging films, laminates, and the like by utilizing characteristics such as high rigidity, low specific gravity, transparency, heat resistance, and solvent resistance. In packaging applications, it is an element that enhances the value of a product that a product can be seen through a film and that a printed image can be seen clearly even in a laminate that provides surface protection.
Among them, polypropylene homopolymer (homo PP) is excellent in rigidity, but has high crystallinity, so that spherulites become large, transparency is insufficient, and impact strength at low temperature is lowered. On the other hand, propylene-ethylene random copolymers and the like are excellent in transparency, but have a drawback that they are inferior in rigidity compared to homo PP.

  In addition, due to the growing interest in global environmental issues, various companies are actively working to reduce depleted resources. Maintaining the properties of already used materials, such as rigidity and transparency, is indispensable for the need to reduce the thickness.

Therefore, recently, in order to obtain a film excellent in transparency, rigidity and dimensional stability, a polypropylene resin composition containing an ethylene polymer in which density and melt flow rate are adjusted with respect to a propylene polymer. Has been proposed (see, for example, Patent Document 1).
Also, from the viewpoint of balancing rigidity and transparency, paying attention to density, α crystal form content, orientation degree measured by wide angle X-ray diffraction method, etc., proposal of manufactured polypropylene unstretched film, etc. (For example, refer to Patent Document 2).
However, a film obtained by using the polypropylene resin composition disclosed in the above-mentioned patent documents is not necessarily satisfactory in terms of transparency, rigidity, or a balance thereof. There is a need for excellent films.

JP 2008-127487 A JP 2011-236357 A

  An object (problem) of the present invention is to provide a polypropylene-based resin composition for a high-rigidity film having an excellent balance between rigidity and transparency in view of the above-mentioned problems of the prior art.

  As a result of intensive studies to solve the above problems, the inventor of the present invention has a propylene-α-olefin random copolymer and a resin component containing a specific alicyclic hydrocarbon resin in a specific ratio. We found that when a specific amount of a nucleating agent represented by a specific chemical structural formula is blended, a polypropylene resin composition for a high-rigidity film that exhibits high heat resistance and excellent transparency and rigidity can be obtained. Based on this, the present invention has been completed.

That is, according to 1st invention of this invention, with respect to 100 weight part of resin components containing 60 to 90 weight% of component (a) shown below and component (b) 10 to 40 weight%, the following general formula A polypropylene resin composition for a high-rigidity film, comprising 0.01 to 0.5 parts by weight of a nucleating agent (c) comprising the compound represented by (1) is provided.
Component (a): Propylene-α-olefin random copolymer Component (b): Alicyclic hydrocarbon selected from the group consisting of petroleum resins, terpene resins, rosin resins, coumarone indene resins and hydrogenated derivatives thereof. resin

（式中、ｎは、０〜２の整数であり、Ｒ^１〜Ｒ^５は、それぞれ独立に、同一または異なって、水素原子、ハロゲン原子または炭素数１〜２０のアルキル基、アルケニル基、アルコキシ基、カルボニル基もしくはフェニル基であり、Ｒ^６は、炭素数が１〜２０のアルキル基である。）

(In the formula, n is an integer of 0 to 2, and R ^{1 to} R ⁵ are independently the same or different and are each a hydrogen atom, a halogen atom, or an alkyl group, alkenyl group, alkoxy group having 1 to 20 carbon atoms. Group, carbonyl group or phenyl group, and R ⁶ is an alkyl group having 1 to 20 carbon atoms.)

Moreover, according to the second invention of the present invention, there is provided a polypropylene resin composition for a high-rigidity film according to the first invention, wherein the α-olefin of component (a) is ethylene.
Further, according to the third invention of the present invention, in the first or second invention, the alicyclic hydrocarbon resin of the component (b) has a softening point temperature of 110 ° C. or higher, and has high rigidity. A polypropylene resin composition for a film is provided.

  According to the fourth invention of the present invention, in any one of the first to third inventions, the propylene-α-olefin random copolymer of component (a) is polymerized by a single site catalyst. A polypropylene resin composition for high-rigidity films is provided.

According to a fifth aspect of the present invention, at least one layer containing a polypropylene resin composition for a high-rigidity film according to any one of the first to fourth aspects is provided. A rigid multilayer film is provided.
Furthermore, according to a sixth aspect of the present invention, there is provided the high-rigidity multilayer film according to the fifth aspect, wherein the layer containing the polypropylene resin composition for a high-rigidity film is an intermediate layer. The

  The polypropylene resin composition for high-rigidity films of the present invention has high commercial value as having both transparency and rigidity. The film obtained from this polypropylene resin composition can be widely used as packaging products in various fields such as foods, detergents, and medical supplies.

The polypropylene resin composition for high-rigidity films of the present invention comprises a propylene-α-olefin random copolymer (hereinafter also referred to as component (a)) 60 to 90% by weight, a petroleum resin, a terpene resin, and a rosin resin. 100 parts by weight of a resin component containing 10 to 40% by weight of an alicyclic hydrocarbon resin (hereinafter also referred to as component (b)) selected from the group consisting of resins, coumarone indene resins and hydrogenated derivatives thereof And 0.05 to 1 part by weight of the nucleating agent (c) represented by the general formula (1).
Hereinafter, the polypropylene resin composition for high-rigidity films will be described in detail for each item.

1. Propylene-α-olefin random copolymer (component (a))
In the polypropylene resin composition for high-rigidity films of the present invention, a propylene-α-olefin random copolymer is used as component (a).

The propylene-α-olefin random copolymer used in the present invention is preferably polymerized with a single-site catalyst (based on a combination of a supported or non-supported metallocene type compound and an organoaluminum compound). Used.
A single site catalyst refers to a catalyst having the same active site (single site), and specifically includes a metallocene catalyst. The propylene-α-olefin random copolymer obtained with such a single-site catalyst is rich in flexibility and a large amount compared to the propylene-α-olefin random copolymer obtained with a conventional Ziegler catalyst. Even if the inorganic filler is blended, flexibility can be maintained. Moreover, melting | fusing point is also high compared with an ethylene-type copolymer, and can improve the heat resistance of a polypropylene-type resin composition.

In the propylene-α-olefin random copolymer according to the present invention, examples of the α-olefin used include α-olefins having 2 to 20 carbon atoms excluding propylene, such as ethylene, 1-butene and 1-pentene. 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1 Examples include -tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene and the like.
Moreover, the α-olefin copolymerized with propylene may be used alone or in combination of two or more. Of these, ethylene and butene-1 are preferred. The content of the α-olefin is preferably 1.0 to 10.0% by weight, more preferably 1.10% by weight with respect to 100% by weight of the propylene-α-olefin random copolymer from the viewpoint of a balance between rigidity and transparency. 0 to 5.5% by weight.

The polymerization method of the propylene-α-olefin random copolymer is not particularly limited and is preferably a slurry method using an inert solvent in the presence of a single site catalyst, a gas phase method substantially using no solvent, Examples thereof include a solution method and a bulk polymerization method using a polymerization monomer as a solvent.
The propylene-α-olefin random copolymer used in the present invention preferably has a melt flow rate (MFR) measured in accordance with JIS K7210 (230 ° C., 2.1 kg load) from the viewpoint of moldability, preferably 2. -15 g / 10 min, more preferably 2-10 g / 10 min. The method for controlling the MFR value is well known, and can be easily adjusted by adjusting the temperature and pressure, which are polymerization conditions, or by controlling the amount of hydrogen or other chain transfer agent added during the polymerization. it can.

The melting point of the propylene-α-olefin random copolymer used in the present invention is preferably 120 to 155 ° C, more preferably 125 to 145 ° C, from the viewpoint of the balance between rigidity and transparency. Control of the melting point of the propylene-α-olefin random copolymer is well known, and can be achieved by appropriately adjusting the amount ratio of propylene supplied to the polymerization layer and α-olefin such as ethylene. In order to control the melting point (Tm) to, for example, 125 to 145 ° C., the content of α-olefin such as ethylene is about 1.5 to 3.5% by weight, although it depends on the type of catalyst used. By adjusting within the range, a propylene-α-olefin random copolymer having a desired melting point can be produced.
The melting point of the propylene-α-olefin random copolymer is measured by a differential scanning calorimeter (DSC) in accordance with JIS K7121: 1987 “Method for measuring plastic transition temperature”. It is a peak temperature of a melting curve when melted from 10 ° C. to 200 ° C. at a heating rate of 10 ° C./min. The melting point is measured by using DSC / RDC220U manufactured by Seiko Co., Ltd., taking 5.0 mg of sample, holding at 40 ° C. for 1 minute, and then melting to 200 ° C. at a heating rate of 10 ° C./min. Was the melting point (Tm) (unit: ° C.).
A commercially available product can be used as such a propylene-α-olefin random copolymer. Specifically, trade name “WINTEC WFW5T” (propylene-ethylene random copolymer) manufactured by Nippon Polypro Co., Ltd. and the like can be mentioned.

  In the polypropylene resin composition for high-rigidity films of the present invention, the blending amount of the propylene-α-olefin random copolymer is 60 to 90% by weight, preferably 65 to 85% by weight, more preferably 70 to 80%. % By weight.

2. Alicyclic hydrocarbon resin (component (b))
In the polypropylene resin composition for high-rigidity films of the present invention, the alicyclic hydrocarbon resin component used as component (b) is petroleum resin, terpene resin, rosin resin, coumarone indene resin, and hydrogenated derivatives thereof. One or more selected from the group consisting of
Among these, resins having no polar group or resins having a hydrogenation rate of 95% by weight or more by adding hydrogen are preferable. Further preferred resins are petroleum resins or hydrogenated derivatives of petroleum resins. Examples of such petroleum resins include the trade name “Arcon” manufactured by Arakawa Chemical Industries, Ltd. or the trade name “Opera” manufactured by Tonen Chemical Co., Ltd. (OPPERA) "etc. are mentioned.

The alicyclic hydrocarbon resin component (b) preferably has a softening point temperature of 110 to 160 ° C, more preferably 120 to 145 ° C. If the softening point temperature is less than 110 ° C, bleeding to the film surface may occur and the transparency may be lowered. On the other hand, if the softening point temperature exceeds 160 ° C, the transparency may be impaired. .
The softening point of the alicyclic hydrocarbon resin component can be measured by, for example, the method of JIS K2207.

In the polypropylene resin composition for high-rigidity films of the present invention, the amount of the alicyclic hydrocarbon resin component (b) is 10 to 40% by weight, preferably 15 to 35% by weight, more preferably 20 to 20%. 30% by weight. That is, the blending amount of the propylene-α-olefin random copolymer (a) is 60 to 90% by weight, preferably 65 to 85% by weight, and more preferably 70 to 80% by weight.
When the blending amount of the alicyclic hydrocarbon resin component (b) is less than the above range, the rigidity is lowered, whereas when it exceeds the above range, the transparency is impaired.

3. Nucleator (c)
A nucleating agent (c) is blended in the polypropylene resin composition for high-rigidity films of the present invention.
As the nucleating agent, a nucleating agent represented by the following general formula (1) is used.

（式中、ｎは、０〜２の整数であり、Ｒ^１〜Ｒ^５は、それぞれ独立に、同一または異なって、水素原子、ハロゲン原子または炭素数１〜２０のアルキル基、アルケニル基、アルコキシ基、カルボニル基もしくはフェニル基であり、Ｒ^６は、炭素数が１〜２０のアルキル基である。）

(In the formula, n is an integer of 0 to 2, and R ^{1 to} R ⁵ are independently the same or different and are each a hydrogen atom, a halogen atom, or an alkyl group, alkenyl group, alkoxy group having 1 to 20 carbon atoms. Group, carbonyl group or phenyl group, and R ⁶ is an alkyl group having 1 to 20 carbon atoms.)

In the general formula (1), preferably, n is an integer of 0 to 2, R ¹ , R ² , R ⁴ and R ⁵ are each a hydrogen atom, and R ³ and R ⁶ are the same or different. And an alkyl group having 1 to 20 carbon atoms.
More preferably, n is an integer of 0 to 2, R ¹ , R ² , R ⁴ and R ⁵ are each a hydrogen atom, and R ³ is —CH ₃ , —CH ₂ CH ₃ , —CH. _{2 CH 2 CH 3, -CH 2} CH 2 CH 2 CH 3, -CH 2 CH = CH 2, -CH (CH 3) CH = CH 2, -CH 2 CH-X 1 -CH 2 -X 2, - CH ₂ CH—X ³ —CH ₂ CH ₃ , —CH ₂ CH—X ⁴ —CH ₂ OH or —CH ₂ OH—CH (OH) —CH ₂ OH (where X ^{1 to} X ⁴ are each It is a group containing an independent halogen atom.), R ⁶ is preferably an alkyl group having 1 to 20 carbon atoms.

  Further, when the nucleating agent is represented by the following chemical structural formula (2), the transparency is extremely excellent and the gel-sol transition temperature is 170 ° C., which is a typical nucleating agent, dibenzylidene sorbitol. Compared to the system nucleating agent, the temperature is lowered by about 20 ° C., so that even when the molding temperature is lowered by about 20 ° C. or more, good transparency can be obtained, which is very preferable.

A commercially available product can be used as such a nucleating agent. Specific examples include trade names Mirad NX8000 and NX8000J manufactured by Milliken.
Further, the nucleating agent (c) according to the present invention not only prevents the development of spherulites by simply refining the crystal of the polypropylene polymer, but also homogenizes and refines the amorphous portion having a relatively low melting point. By doing so, the crystallization temperature of the polypropylene-based polymer is increased, which results in increasing the strength of the waist as a packaging film.

  In the polypropylene resin composition for high-rigidity films of the present invention, the compounding amount of the nucleating agent (c) is propylene-α-olefin random copolymer (component (a)) and alicyclic hydrocarbon resin component (component). It is 0.01-0.5 weight part with respect to 100 weight part of total resin components of (b)). The blending amount of the nucleating agent is more preferably 0.05 to 0.4 parts by weight, further preferably 0.1 to 0.3 parts by weight. When the blending amount of the nucleating agent is less than the above range, the transparency is lowered, and exceeding the above range is economically undesirable.

Further, in the polypropylene resin composition for high-rigidity films of the present invention, aromatic carboxylic acid metal salts, aromatic phosphate metal salts, sorbitol derivatives as other nucleating agents within the range not inhibiting the effects of the present invention. An amine compound can be used, and it can be used in combination with the nucleating agent represented by the general formula (1).
Among these nucleating agents, p-t-butylbenzoate aluminum, 2,2′-methylenebis (4,6-di-t-butylphenyl) sodium phosphate, 2,2′-methylenebisphosphate (4 , 6-Di-tert-butylphenyl) aluminum, p-methyl-benzylidene sorbitol, p-ethyl-benzylidene sorbitol, 1,3,2,4-dibenzylidene sorbitol, 1,3,2,4-bis (p- Methylbenzylidene) sorbitol, 1,3-p-chlorobenzylidene-2,4-p-methylbenzylidenesorbitol, 1,3,2,4-bis (p-ethylbenzylidene) sorbitol, 1,3,2,4 -A nucleating agent such as bis (3,4-dimethylbenzylidene) sorbitol.

4). Other Additives In the polypropylene resin composition for high-rigidity films of the present invention, in addition to the propylene-α-olefin random copolymer (a), the alicyclic hydrocarbon resin (b), and the nucleating agent (c). In addition, various antioxidants, neutralizers, lubricants, ultraviolet absorbers, light stabilizers and the like that are used as stabilizers for propylene polymers can be blended.

Specifically, as the antioxidant, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, di-stearyl-pentaerythritol-di-phosphite, bis ( 2,4-di-t-butylphenyl) pentaerythritol-diphosphite, tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-t-butylphenyl) -4 Phosphorous antioxidants such as 4,4'-biphenylene-diphosphonite, tetrakis (2,4-di-t-butyl-5-methylphenyl) -4,4'-biphenylene-diphosphonite, 2,6-di-t-butyl-p-cresol, tetrakis [methylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate)] methane, 1, , 5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, etc. Phenolic antioxidants, di-stearyl-ββ'-thio-di-propionate, di-myristyl-ββ'-thio-di-propionate, di-lauryl-ββ'-thio-di-propionate, etc. An inhibitor etc. are mentioned.
Also, amine antioxidants, lactone antioxidants such as 5,7-di-t-butyl-3- (3,4-di-methyl-phenyl) -3H-benzofuran-2-one, vitamin E series An antioxidant etc. can be mentioned.

Specific examples of the neutralizing agent include metal fatty acid salts such as calcium stearate, zinc stearate, and magnesium stearate, hydrotalcite, and the like.
Specific examples of the lubricant include known lubricants, and examples thereof include fatty acid amides such as oleic acid amide, stearic acid amide, erucic acid amide, and behenic acid amide, butyl stearate, and silicone oil.
Examples of the ultraviolet absorber include 2-hydroxy-4-n-octoxybenzophenone, 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) -5-chlorobenzotriazole, 2- And UV absorbers such as (2′-hydroxy-3′-t-butyl-5′-methylphenyl) -5-chlorobenzotriazole.

  Examples of the light stabilizer include n-hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate, 2,4-di-t-butylphenyl-3 ′, 5′-di-t-butyl-4 ′. Examples thereof include light stabilizers such as -hydroxybenzoate and dimethyl-2- (4-hydroxy-2,2,6,6-tetramethyl-1-piperidyl) ethanol condensate of succinate.

  In addition, anti-blocking agents, antistatic agents, dispersants such as fatty acid metal salts, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, olefin-based elastomers, and the like are within a range that does not impair the purpose of the present invention. Can be appropriately blended. When linear low density polyethylene and an olefin elastomer are blended, those polymerized with a metallocene catalyst are preferred from the viewpoint of transparency.

5). Method for Producing Polypropylene Resin Composition The polypropylene resin composition for high-rigidity films of the present invention comprises a propylene-α-olefin random copolymer (a), an alicyclic hydrocarbon resin (b), a nucleating agent (c ) And other additives used as necessary into a Henschel mixer, super mixer, ribbon blender, etc., and then mixed, then a normal single screw extruder, twin screw extruder, Banbury mixer, Brabender, roll, etc. Can be obtained by melt-kneading in a temperature range of 180 to 280 ° C.

6). Use of Polypropylene Resin Composition The polypropylene resin composition of the present invention is particularly excellent in the balance between rigidity and transparency. Therefore, it is suitably used for film applications, in particular, packaging applications such as food, medicine, stationery, and miscellaneous goods.
In addition, a film using the polypropylene resin composition of the present invention has no whiteness, has a clear transparency, and has extremely high commercial value as a packaging material having excellent rigidity.
The film formed by molding the polypropylene resin composition of the present invention is also preferably used as a protective film for electrical products, furniture, and industrial products such as automobiles.

In order to produce such a film, it can be formed using a known casting method, inflation method, stretching method or the like. Of these, the casting method and the water-cooled inflation method are preferable.
The casting method is a method for producing an extrusion-molded body such as a sheet or a film (unstretched film). The resin composition melt-kneaded by an extruder is extruded from a T-die and passed through a roll through which a coolant such as water passes. Since the film is cooled by being brought into contact with the film and can generally produce a film having good transparency and glossiness and good thickness accuracy, it is a preferable production method for the film.

  When the film using the polypropylene resin composition of the present invention is molded and used as a single layer film, the thickness is usually 5 to 500 μm, preferably 10 to 200 μm. Even if the thickness is less than 5 μm or more than 500 μm, the processing becomes difficult.

  A film using the polypropylene resin composition of the present invention may be produced by an inflation method. The inflation method is a method for producing a film by melting it with an extruder with an annular die, extruding it into a tube shape, and cooling it with water cooling and air cooling. The thickness of the film is usually preferably 10 to 150 μm.

  Further, the film using the polypropylene resin composition of the present invention may be in the form of a stretched film. In that case, the stretched film is a sheet or film obtained as described above using a known stretching device. It can be manufactured by stretching. Examples of these stretching apparatuses include a tenter method, a simultaneous biaxial stretching method, and a uniaxial stretching method. The stretch ratio of the stretched film is desirably 10 to 70 times in the case of a biaxially stretched film, and desirably 2 to 10 times in the case of a uniaxially stretched film. Moreover, it is desirable that the thickness of the stretched film is usually 5 to 200 μm.

From the viewpoint of transparency and rigidity characteristics of the film using the polypropylene resin composition of the present invention, the significance of the film for packaging as a specific application will be described in more detail.
The packaging film is required to have characteristics that can be adapted to diversification of packaging forms, taking advantage of its characteristics. For example, in addition to general packaging applications, it can also be used in the field of utilization forms in which many packaging films have been used recently.
(I) Wrapped or stretch wrapping: It is a normal form of use for tightly wrapping with a molded unstretched or stretched wrapping film, which can be expressed as wrap or stretch wrapping.
(II) Shrink wrapping: This is a form of wrapping utilizing the heat-shrinkable nature of the packaging film, and this is expressed as shrink wrapping.
(III) Vacuum packaging: This is a technique in which the contents are covered with a film, and the intervening air is sucked by a vacuum forming machine and closely packed.
(IV) Retort packaging; a packaging form corresponding to retort processing.
(V) Laminated film: A composite film in which a film using the polypropylene resin composition of the present invention is laminated with another polypropylene packaging film or a polyethylene packaging film other than polypropylene.
Thus, the film using the polypropylene resin composition of the present invention includes embodiments that can be used in various packaging forms and packaging methods, and such a packaging form as the polypropylene packaging film of the present invention. It has characteristics and performance that can be applied to diversification.

In the above (V) laminated film (multilayer film), as a layer other than the film formed by molding the polypropylene resin composition of the present invention, for example, a layer composed of a resin mainly composed of polypropylene other than the present invention, Examples thereof include a layer made of a resin mainly composed of an ethylene polymer, a layer made of a polyester resin, and a layer made of a polyamide resin.
Moreover, in the laminated film (multilayer film) according to the present invention, the layer containing the polypropylene-based resin composition for high-rigidity film of the present invention is preferably an intermediate layer.
The thickness of the entire film is preferably 10 to 500 μm, more preferably 10 to 100 μm. The film may be subjected to a surface treatment such as a corona discharge treatment, a flame treatment, a plasma treatment, an ozone treatment or the like by a method that is usually employed industrially.

General functions required for the packaging film include the following.
(I) It has a quality function that appropriately expresses the appearance, state, freshness, and aesthetic appearance of the contents as well as the protection of the contents during transportation, storage, store display, etc. of the contents.
The performance that is excellent in the balance between rigidity and transparency of the film using the polypropylene resin composition of the present invention has the performance that satisfies the above requirements.
(Ii) Increase product value.
Usually, the polypropylene packaging film has a HAZE of about 3 to 10%, and the film using the polypropylene resin composition of the present invention has a HAZE of 4% or less, preferably 2% or less, more preferably 1.0. % Or less can be evaluated as having excellent performance. Similarly, the rigidity is very good.
The characteristics of these packaging films are extremely useful in packaging fresh goods, trendy fibers, clothing and other commodities that require introspection, and for enhancing the commercial value of the contents.
It can be said that the film using the polypropylene resin composition of the present invention has sufficient properties, characteristics, functions, and operational effects that satisfy the requirements (i) to (ii).

Regarding other usage forms, for example, in the applications (I) to (V), the film using the polypropylene resin composition of the present invention has significance, and has high transparency and From the viewpoint of rigidity and the like, it is extremely useful for increasing the commercial value of the contents as shown in (i) to (ii).
As described above, the high-rigidity film using the polypropylene resin composition of the present invention not only plays a role of increasing commercial value in any packaging form, but also maintains the working environment and improves moldability in molding. , With multifaceted significance.

  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 to demonstrate the rationality and significance of the constituent elements of the present invention. The invention is not limited to these examples. In addition, the materials used in Examples and Comparative Examples, physical property measurement methods, and the like are as follows.

1. Resin used (resin composition for high rigidity film for intermediate layer)
(1) Propylene-α-olefin copolymer (component (a))
The following were used as a propylene-alpha-olefin copolymer.
Product name “WINTEC WFW5T” (Propylene-ethylene random copolymer, polymerized with metallocene catalyst, MFR: 7 g / 10 min, melting point: 145 ° C.)
(2) Alicyclic hydrocarbon resin (component (b))
The following were used as the alicyclic hydrocarbon resin.
(B-1): Tonen Chemical Co., Ltd., trade name “OPPERA PR130” (softening point: 137 ° C.)
(B-2): Arakawa Chemical Industries, trade name “Arcon P140” (softening point: 140 ° C.)
(3) Nucleating agent (component (c))
The following nucleating agents were used.
Product name “Millad NX8000J” manufactured by Milliken Chemical

2. Resin used (resin used on outer and inner layers)
(1) Resin used for outer layer and inner layer The following were used as propylene polymers.
Product name “WINTEC WFX4TA” manufactured by Nippon Polypro Co., Ltd. (propylene-ethylene random copolymer, polymerized with metallocene catalyst, MFR: 7 g / 10 min, melting point: 125 ° C.)

3. Compound of nucleating agent master batch In order to add the nucleating agent constituting the resin composition for high rigidity film with good dispersion, a master batch based on propylene-ethylene random copolymer powder was prepared in advance.
90% by weight of propylene-ethylene random copolymer powder (WINTEC WFW5T), 10% by weight of a nucleating agent (Millad NX8000J), and other additives such as antioxidants are added and dry-blended and melt-kneaded for nucleation. An agent master batch pellet (C) was obtained.

4). Compound of resin composition for high-rigidity film As a base of resin composition for high-rigidity film, component (a) and component (b) are dry-blended as shown in Table 1 below, melt-kneaded, and resin composition for high-rigidity film The base material (A-1-4) of the thing was obtained.

5). Manufacture of multi-layer film As an extruder for an intermediate layer, a single-screw extruder with a diameter of 35 mm, an extruder for an outer layer and an inner layer, a single-screw extruder with a diameter of 20 mm, an opening length of 300 mm and a Lip width of 0.7 mm Extruded from a three-type three-layer multi-manifold die at a set temperature of 240 ° C., cooled by a cooling roll flowing water at a temperature of 30 ° C., molded at a speed of 15 m / min, cut off both ends with non-uniform thickness, The thickness of each layer was 4 μm (outer layer) / 9 μm (intermediate layer) / 12 μm (inner layer), and a film having a total thickness of 25 μm was obtained.
Next, the obtained multilayer film was conditioned for 24 hours or more in an atmosphere of 23 ° C. and 50% RH. The physical properties of the obtained multilayer film were evaluated.

6). Evaluation method of multilayer film (1) Transparency (HAZE)
Based on JIS K7136-2000, the transparency of the formed multilayer film was measured with a haze meter.
The smaller the obtained value, the better the transparency. When this value is 7% or less, it is excellent in obtaining a display effect (visualization of contents, finished processing such as laminate), and 4% or less. Is preferable, 2% or less is more preferable, and 1.0% or less is particularly preferable.

(2) Rigidity (tensile modulus)
Based on JIS K7127-1989, the tensile elastic modulus about the flow direction (MD) and the width direction (TD) of the multilayer film shape | molded on the following conditions was measured, and it evaluated by the total value of TD and MD.
The larger the value obtained, the higher the rigidity, and when the total value of TD and MD is 1000 MPa or more, the workability at the time of post-processing such as laminating (film cutting work, etc.) is excellent, and 1200 MPa or more. Is preferable, and 1400 MPa or more is particularly preferable.
・ Sample length: 150mm
・ Sample width: 15mm
・ Distance between chucks: 100mm
・ Crosshead speed: 1mm / min

[Example 1]
Propylene-α-olefin random copolymer (component (a)) (trade name “WINTEC WFW5T” (propylene-ethylene random copolymer) manufactured by Nippon Polypro Co., Ltd.) and alicyclic hydrocarbon resin (component) (B)) (Tonen Kagaku brand name “OPPER PR130” (softening point: 137 ° C.) (B-1)) 20% by weight of dry blend, melt kneaded, and base material for resin composition for high rigidity film ( A-1) was obtained.
Add 90% by weight of propylene-ethylene random copolymer powder (WINTEC WFW5T), 10% by weight of a nucleating agent (product name “Millad Chemical NX8000J” manufactured by Milliken Chemical), and other additives such as antioxidants as appropriate. Blending and melt-kneading yielded a nucleating agent master batch pellet (C).
With respect to 100 parts by weight of the base material (A-1), 1 part by weight of the nucleating agent master batch pellet (C) was blended to obtain an intermediate layer use resin.
As the resin used for the outer layer and the inner layer, a propylene polymer (trade name “WINTEC WFX4TA” manufactured by Nippon Polypro Co., Ltd.) was used.
As an intermediate layer extruder, a 35 mm diameter single screw extruder, and as an outer layer and inner layer extruder, a 20 mm diameter single screw extruder, three types and three layers with an opening length of 300 mm and a Lip width of 0.7 mm Extruded from a multi-manifold die at a set temperature of 240 ° C., cooled by a cooling roll flowing water at a temperature of 30 ° C., molded at a speed of 15 m / min, cut off both ends with non-uniform thickness, and the thickness of each layer A film having a total thickness of 25 μm was obtained at 4 μm (outer layer) / 9 μm (intermediate layer) / 12 μm (inner layer).
Next, the obtained multilayer film was conditioned for 24 hours or more in an atmosphere of 23 ° C. and 50% RH. The physical properties of the obtained multilayer film were evaluated.
The evaluation results are shown in Table 2 below.

[Example 2]
In Example 1, the multilayer film is formed in the same manner as in Example 1 except that the amount of the nucleating agent master batch pellet (C) is 2 parts by weight with respect to 100 parts by weight of the base material (A-1). Obtained.
The physical properties of the obtained multilayer film were evaluated. The evaluation results are shown in Table 2 below.

[Example 3]
In Example 1, the multilayer film was formed in the same manner as in Example 1 except that the amount of the nucleating agent master batch pellet (C) was 3 parts by weight with respect to 100 parts by weight of the base material (A-1). Obtained.
The physical properties of the obtained multilayer film were evaluated. The evaluation results are shown in Table 2 below.

[Example 4]
In Example 1, the base material (A-2) was obtained by setting the content of the component (a) to 70% by weight and the content of the component (b) to 30% by weight in the high-rigidity film resin composition. Furthermore, the compounding quantity of the nucleating agent master batch pellet (C) was 2 parts by weight with respect to 100 parts by weight of the base material (A-2). Other than that was carried out similarly to Example 1, and obtained the multilayer film.
The physical properties of the obtained multilayer film were evaluated. The evaluation results are shown in Table 2 below.

[Example 5]
In Example 2, as the component (b), instead of the trade name “OPPER PR130” (softening point: 137 ° C.) (B-1) manufactured by Tonen Chemical Co., Ltd., the trade name “Arcon P140” (softening) manufactured by Arakawa Chemical Industries, Ltd. Point: 140 ° C.) (B-2) was used to obtain the base material (A-3) while keeping the content of the component (b) in the resin composition for high-rigidity films. Other than that was carried out similarly to Example 2, and obtained the multilayer film.
The physical properties of the obtained multilayer film were evaluated. The evaluation results are shown in Table 2 below.

[Example 6]
In Example 5, the base material (A-4) was obtained by setting the content of the component (a) to 70% by weight and the content of the component (b) to 30% by weight in the high-rigidity film resin composition. Other than that was carried out similarly to Example 5, and obtained the multilayer film.
The physical properties of the obtained multilayer film were evaluated. The evaluation results are shown in Table 2 below.

[Comparative Example 1]
Propylene-α-olefin random copolymer (component (a)) (manufactured by Nippon Polypro Co., Ltd., trade name “WINTEC WFW5T” (propylene-ethylene random copolymer)) is 100% by weight, and component (b) (alicyclic ring) An intermediate layer use resin containing no formula hydrocarbon resin) and component (c) (nucleating agent master batch pellet (C)) was obtained. Other than that was carried out similarly to Example 1, and obtained the multilayer film.
The physical properties of the obtained multilayer film were evaluated. The evaluation results are shown in Table 2 below.

[Comparative Example 2]
In Example 2, the base material (A-1) consisting of the component (a) 80% by weight and the component (b) 20% by weight of the base material of the resin composition for film was obtained. The resin used for intermediate | middle layer was obtained, without mix | blending a component (c) (nucleating agent masterbatch pellet (C)) with this. Other than that was carried out similarly to Example 2, and obtained the multilayer film.
The physical properties of the obtained multilayer film were evaluated. The evaluation results are shown in Table 2 below.

[Comparative Example 3]
In Example 4, a base material (A-2) composed of 70% by weight of component (a) and 30% by weight of component (b) in the amount of the base material of the resin composition for film was obtained. The resin used for intermediate | middle layer was obtained, without mix | blending a component (c) (nucleating agent masterbatch pellet (C)) with this. Other than that was carried out similarly to Example 4, and obtained the multilayer film.
The physical properties of the obtained multilayer film were evaluated. The evaluation results are shown in Table 2 below.

[Comparative Example 4]
In Example 5, the base material (A-3) comprising the component (a) 80% by weight and the component (b) 20% by weight of the base material of the resin composition for film was obtained. The resin used for intermediate | middle layer was obtained, without mix | blending a component (c) (nucleating agent masterbatch pellet (C)) with this. Other than that was carried out similarly to Example 5, and obtained the multilayer film.
The physical properties of the obtained multilayer film were evaluated. The evaluation results are shown in Table 2 below.

[Comparative Example 5]
In Example 6, a base material (A-4) comprising 70% by weight of the component (a) and 30% by weight of the component (b) in the blending amount of the base material of the resin composition for film was obtained. The resin used for intermediate | middle layer was obtained, without mix | blending a component (c) (nucleating agent masterbatch pellet (C)) with this. Other than that was carried out similarly to Example 6, and obtained the multilayer film.
The physical properties of the obtained multilayer film were evaluated. The evaluation results are shown in Table 2 below.

  As is clear from Table 2, the multilayer films of Examples 1 to 6 using the polypropylene resin composition for high-rigidity films of the present invention as an intermediate layer have high tensile elastic modulus and good transparency. I understand. On the other hand, it turns out that the multilayer film of Comparative Examples 1-5 is not good balance of tensile elasticity modulus and transparency. In particular, Comparative Examples 4 and 5 have the same level of transparency as Examples 5 and 6, but the tensile elastic modulus is inferior and the balance between tensile elastic modulus and transparency is not good.

  The polypropylene resin composition for high-rigidity films of the present invention is extremely useful as having both transparency and rigidity. By film-processing this, it can be widely used especially as packaging products in various fields such as foods, detergents and medical supplies. Further, the molding has multifaceted significance such as maintenance of working environment and improvement of moldability.

Claims (6)

A nucleating agent comprising a compound represented by the following general formula (1) with respect to 100 parts by weight of a resin component containing 60 to 90% by weight of the component (a) shown below and 10 to 40% by weight of the component (b) ( c) A polypropylene-based resin composition for high-rigidity films, containing 0.01 to 0.5 part by weight.
Component (a): Propylene-α-olefin random copolymer Component (b): Alicyclic hydrocarbon selected from the group consisting of petroleum resins, terpene resins, rosin resins, coumarone indene resins, and hydrogenated derivatives thereof. resin

(In the formula, n is an integer of 0 to 2, and R ^{1 to} R ⁵ are independently the same or different and are each a hydrogen atom, a halogen atom, or an alkyl group, alkenyl group, alkoxy group having 1 to 20 carbon atoms. Group, carbonyl group or phenyl group, and R ⁶ is an alkyl group having 1 to 20 carbon atoms.)   The α-olefin as the component (a) is ethylene, and the polypropylene-based resin composition for high-rigidity films according to claim 1.   The polypropylene resin composition for a high-rigidity film according to claim 1 or 2, wherein the alicyclic hydrocarbon resin as the component (b) has a softening point temperature of 110 ° C or higher.   The polypropylene resin composition for a high-rigidity film according to any one of claims 1 to 3, wherein the propylene-α-olefin random copolymer of the component (a) is polymerized by a single site catalyst. object.   A high-rigidity multilayer film comprising at least one layer containing the polypropylene-based resin composition for a high-rigidity film according to any one of claims 1 to 4.   The high-rigidity multilayer film according to claim 5, wherein the layer containing the polypropylene-based resin composition for a high-rigidity film is an intermediate layer.