JP6395495B2 - Film or sheet obtained from a polypropylene composition - Google Patents

Description

  The present invention relates to a film or sheet obtained from a polypropylene composition.

  Polypropylene is useful as a food container because it has excellent physical properties and excellent hygiene. For example, it has been proposed to produce a food container by mixing a nucleating agent with polypropylene to obtain a sheet and vacuum forming the sheet (Patent Documents 1 to 5). However, the polypropylene container thus obtained has a problem that the impact resistance is lowered when it is used at a low temperature. In order to improve this, for example, it has been proposed to add an ethylene-based copolymer to polypropylene (Patent Document 6).

JP 2000-334823 A JP 59-171625 A JP 2006-193539 A JP-A-7-286007 JP-A-10-292074 Special table 2011-513528

  The inventors preliminarily studied the technology described in the patent literature, and as a result of the addition of the ethylene copolymer, the transparency is lowered. Therefore, the conventional polypropylene sheet has satisfactory transparency and cold shock resistance. I got the knowledge that I did not. In view of such circumstances, an object of the present invention is to provide a sheet obtained from a polypropylene composition, which is excellent in transparency and cold shock resistance.

The inventors have found that the above problem can be solved by biaxially stretching a specific polypropylene composition under a specific temperature condition, and have completed the present invention. That is, the said subject is solved by the following this invention.
[1] Component (1) 70 to 97% by weight of a copolymer of 1.0 to 5.0% by weight of ethylene or propylene containing one or more C4 to C10-α-olefins;
Component (2) 3-30 wt% ethylene (co) polymer selected from the group consisting of ethylene polymers and copolymers of ethylene and one or more C3-C10-α-olefins; and Component (3 ) a nucleating agent, a melt mass Furore wells (230 ° C., load 21.18 N) is 1.0~10g / 10 min,
A polypropylene composition having an XSIV (intrinsic viscosity of xylene solubles) of 0.5 to 2.0 dl / g,
A sheet or film obtained by a method including a step of biaxial stretching at a temperature Ts (° C.),
In the second scan of the polypropylene composition with a differential scanning calorimeter (DSC), when the peak top temperature of the melting point on the highest temperature side derived from the component (1) or (2) is Tm (° C.),
0 ≦ Ts−Tm ≦ 10 is satisfied,
Sheet or film.
[2] A sheet or film according to [1] obtained by a method further comprising a step of cooling while maintaining the surface state of the molded body after biaxial stretching. [3] Of the components (1) and (2) The sheet or film according to [1] or [2], containing 0.05 to 1.0 part by weight of the nucleating agent with respect to 100 parts by weight in total. [4] The polypropylene composition is a raw material of the component (1) Propylene and ethylene or C4 to C10-α-olefin, and ethylene which is a raw material of component (2), or ethylene and C3 to C10 α-olefin using two or more reactors,
(A) a solid catalyst containing magnesium, titanium, halogen, and a dicarboxylic acid diester as an electron donor compound,
(B) An organoaluminum compound, and (C) A composition produced by a method comprising a step of polymerizing using a catalyst containing an external electron donor compound, according to any one of [1] to [3] Sheet or film.
[5] The sheet or film according to any one of [1] to [4], wherein the component (2) is a copolymer of ethylene and one or more C4 to C10-α-olefins.
[6] A molded article having a layer comprising the sheet or film according to any one of [1] to [5].
[7] A secondary molded body obtained by molding the sheet or film according to any one of [1] to [5].
[8] Component (1) 70 to 97% by weight of a copolymer of 1.0 to 5.0% by weight of ethylene or propylene containing one or more C4 to C10-α-olefins;
Component (2) 3-30 wt% ethylene (co) polymer selected from the group consisting of ethylene polymers and copolymers of ethylene and one or more C3-C10-α-olefins; and Component (3 ) Including nucleating agents,
Melt Mass Furore wells (230 ° C., load 21.18 N) is 1.0~10g / 10 min,
Preparing a polypropylene composition having an XSIV (intrinsic viscosity of xylene solubles) of 0.5 to 2.0 dl / g,
Biaxially stretching the polypropylene composition at a temperature Ts (° C.),
When the peak top temperature of the melting point on the highest temperature side derived from component (1) or (2) in the second scan in DSC of the polypropylene composition is Tm (° C.)
0 ≦ Ts−Tm ≦ 10 is satisfied,
A method for producing a sheet or film.
[9] The method for producing a sheet or film according to [8], further comprising a step of cooling while maintaining the surface state of the molded body after biaxial stretching.

  In the present invention, a sheet is a member having a thickness of 200 μm or more, and a film is a member having a thickness of less than 200 μm. The sheet of the present invention is obtained by biaxially stretching a specific polypropylene composition at a specific temperature. Hereinafter, the present invention will be described in detail. In the present invention, “X to Y” includes values at both ends, that is, X and Y.

1. Polypropylene Composition The polypropylene composition used in the present invention is (1) a copolymer of 70 to 97% by weight of propylene containing 1.0 to 5.0% by weight of ethylene or one or more C4 to C10-α-olefins. %, (2) ethylene polymer, and 3-30 wt% ethylene (co) polymer selected from ethylene and one or more C3-C10-α-olefin copolymers, and (3) nucleating agent including. The copolymer of propylene containing 1.0% by weight of ethylene is a copolymer in which the weight ratio of ethylene-derived units to propylene-derived units is 1.0: 99.0. The same applies to other copolymers.

(1) Copolymer of propylene The copolymer of propylene contains polypropylene and ethylene or C4-C10-α-olefin (hereinafter also referred to as “comonomer”). The content of conomomer is 1.0 to 5.0% by weight. When the comonomer content is less than the lower limit, the transparency of the resulting sheet or the like is lowered. On the other hand, when the comonomer content exceeds the upper limit value, the rigidity and the stretch processability deteriorate. From these viewpoints, the comonomer content is more preferably 1.5 to 3.5% by weight. Moreover, as a comonomer, ethylene or C4-C6-α-olefin is preferable from the viewpoint of availability, and ethylene is more preferable.

(2) Ethylene (co) polymer The content of ethylene in the ethylene (co) polymer is not limited, but is preferably 50 to 100% by weight. When the ethylene content is 100% by weight, the ethylene (co) polymer is an ethylene homopolymer. In particular, in the case of an ethylene copolymer, the ethylene content is more preferably 50 to 99% by weight, and more preferably 70 to 90% by weight. As the C3-C10-α-olefin, a C3-α-olefin or a C4-α-olefin is preferable from the viewpoint of availability.

(3) Nucleating agent The nucleating agent used in the present invention is an additive used to increase the transparency by controlling the size of the crystal component in the resin to be small. The nucleating agent is not particularly limited, and those commonly used in the field may be used, but nonitol nucleating agent, sorbitol nucleating agent, phosphate ester nucleating agent, triaminobenzene derivative nucleating agent, metal carboxylate It is preferably selected from a salt nucleating agent and a xylitol nucleating agent. Examples of nonitol nucleating agents include 1,2,3-trideoxy-4,6: 5,7-bis-[(4-propylphenyl) methylene] -nonitol.

  Examples of the xylitol-based nucleating agent include bis-1,3: 2,4- (5 ′, 6 ′, 7 ′, 8′-tetrahydro-2-naphthaldehydebenzylidene) 1-allylxylitol, bis-1,3: 2,4- (3 ′, 4′-dimethylbenzylidene) 1-propylxylitol is exemplified.

  Examples of sorbitol nucleating agents include bis-1,3: 2,4- (4′-ethylbenzylidene) 1-allylsorbitol, bis-1,3: 2,4- (3′-methyl-4′-fluoro, -Benzylidene) 1-propylsorbitol, bis-1,3: 2,4- (3 ', 4'-dimethylbenzylidene) 1'-methyl-2'-propenylsorbitol, bis-1,3,2,4-di Benzylidene 2 ′, 3′-dibromopropylsorbitol, bis-1,3,2,4-dibenzylidene 2′-bromo-3′-hydroxypropylsorbitol, bis-1,3: 2,4- (3′-bromo -4'-ethylbenzylidene) -1-allylsorbitol, mono-2,4- (3'-bromo-4'-ethylbenzylidene) -1-allylsorbitol, bis-1,3: 2,4- (4 -Ethylbenzylidene) 1-allylsorbitol, bis-1,3: 2,4- (3 ', 4'-dimethylbenzylidene) 1-methylsorbitol, bis (p-methylbenzylidene) sorbitol, 1,3: 2,4 -Bis-o- (4-methylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-o- (benzylidene) -D-sorbitol, 1,3: 2,4-bis-o- (3 , 4-dimethylbenzylidene) -D-sorbitol and the like.

  Among these, commercially available nucleating agents include, for example, Millad NX8000, NX8000K containing 1,2,3-trideoxy-4,6: 5,7-bis-[(4-propylphenyl) methylene] -nonitol in the nonitol system, NX8000J (manufactured by Milliken Japan Co., Ltd.), RiKAFAST R-1 (manufactured by Nippon Nippon Chemical Co., Ltd.), Millad 3988 (manufactured by Milliken Japan Co., Ltd.), gel all E-200 (manufactured by Nippon Nippon Chemical Co., Ltd.), gel all MD (made by Shin Nippon Rika Co., Ltd.) etc. are mentioned.

  As phosphate nucleating agent, aluminum-bis (4,4 ′, 6,6′-tetra-tert-butyl-2,2′-methylenediphenyl-phosphate) -hydroxide, phosphoric acid-2,2′- And methylene bis (4,6-di-tert-butylphenyl) lithium salt compound. Examples of commercially available phosphate ester nucleating agents include ADK STAB NA-21 (manufactured by ADEKA Corporation) and ADK STAB NA-71 (manufactured by ADEKA Corporation).

  Examples of the triaminobenzene derivative nucleating agent include 1,3,5-tris (2,2-dimethylpropanamide) benzene. As a commercially available triaminobenzene derivative nucleating agent, IRGACEAR XT386 (made by BASF Japan Ltd.) etc. are mentioned, for example.

  Examples of the carboxylic acid metal salt nucleating agent include 1,2-cyclohexanedicarboxylic acid calcium salt. Examples of commercially available carboxylic acid metal salt nucleating agents include Hyperform HPN-20E (manufactured by Milliken Japan Co., Ltd.). In particular, in order to maintain transparency after secondary molding including heating, it is preferable to use a nonitol nucleating agent or a sorbitol nucleating agent. Here, secondary molding means compression molding or vacuum molding, etc., to a film or sheet that is a primary molded product, and processing into a molded product with a different shape, or by fusing the film or sheet together. The obtained molded body is called a secondary molded body.

(4) Blending ratio The blending ratio of the components (1) and (2) is (1) :( 2) = 70-97: 3-30 in weight ratio. When the amount of the component (2) exceeds this upper limit, the rigidity of the obtained sheet or the like decreases, and when it is less than the lower limit, the cold shock resistance of the obtained sheet or the like decreases. From this viewpoint, the compounding ratio of components (1) and (2) is preferably 80 to 96: 4 to 20.

  The blending amount of the nucleating agent is preferably 0.05 to 1.0 part by weight with respect to 100 parts by weight of the total of components (1) and (2). If the amount of the nucleating agent exceeds this upper limit, the cost increases, and if it is less than this lower limit, the transparency of the obtained sheet or the like may be lowered. From this viewpoint, the blending ratio of the nucleating agent is more preferably 0.1 to 1.0, still more preferably 0.2 to 0.7 weight, with respect to 100 parts by weight of the total of the components (1) and (2). Part.

(5) Characteristics 1) Melt 230 ° C. Mass Furore wells polypropylene composition, also referred to as melt mass Furore wells in load 21.18 N (hereinafter "MFR") is 1.0~10g / 10 min. The value of the melt mass Furore wells is, this exceeds the upper limit value and drawdown resistance is reduced at the time of processing, the torque at the time of processing is less than the lower limit value increases. In this respect, the melt mass Furore wells is preferably 1.5~7.0g / 10 min.

2) XSIV
XSIV is the intrinsic viscosity of the xylene-soluble component of the polypropylene composition, and is also an index of the molecular weight of the component having no crystallinity in the composition. XSIV is obtained by obtaining a component soluble in xylene at 25 ° C. and measuring the intrinsic viscosity of the component by a conventional method. In the present invention, XSIV is 0.5 to 2.0 dl / g. When XSIV exceeds 2.0 dl / g, transparency of the sheet | seat etc. which are obtained will fall. If XSIV is less than 0.5 dl / g, the production becomes difficult.

(6) Other components Furthermore, the polypropylene resin composition of the present invention includes an antioxidant, a hydrochloric acid absorbent, a heat stabilizer, a light stabilizer, an ultraviolet absorber, an internal lubricant, an external lubricant, an antistatic agent, a flame retardant, Add conventional additives commonly used in olefin polymers such as dispersants, copper damage inhibitors, neutralizers, plasticizers, anti-bubble agents, crosslinking agents, peroxides, oil-extended and other organic and inorganic pigments May be.

2. Biaxial stretching The biaxially stretched sheet or film of the present invention has at least one layer composed of the polypropylene composition. When the biaxially stretched sheet or film has a layer other than the above polypropylene composition, the other layers are not particularly limited, but a propylene homopolymer, random copolymer, block copolymer, or any of these And a composition containing a polymer other than polypropylene as a main component.

  The biaxially stretched sheet or film of the present invention is preferably obtained by preparing a sheet (preliminary sheet) in advance from the above polypropylene composition and stretching it in the width direction and the flow direction of the preliminary sheet. Stretching in the width direction and the flow direction may be performed simultaneously, or may be performed with a time difference as described later. In a typical method for producing a biaxially stretched polypropylene film, first, a polypropylene composition is melted with an extruder, then extruded into a sheet form from a T-die to prepare a preliminary sheet, and this is cooled and solidified with a cooling roll. Next, the obtained sheet is stretched in the machine direction through a number of heating rolls (longitudinal stretching). Subsequently, the film is stretched in the transverse direction through a heating furnace composed of a preheating part, a stretching part and a heat treatment part (lateral stretching). In compression molding, vacuum molding, or the like, which is also used as a secondary molding technique, a preliminary sheet obtained in advance is biaxially stretched to be shaped to a desired thickness or shape. When the sheet or the like of the present invention has a layer other than the polypropylene composition, a preliminary sheet in which the layer of the polypropylene composition and the other layers are laminated is prepared and stretched as described above. The biaxially stretched sheet of the present invention can be produced.

  The biaxially stretched sheet or film of the present invention is obtained by biaxially stretching in the stage where the molten resin extruded from the die is solidified after melting the polypropylene composition with an extruder, as in calendar molding or inflation molding. Is also possible.

  In the present invention, a sheet or film is obtained by a method including a step of biaxially stretching a polypropylene composition at a specific temperature Ts. When the biaxial stretching process such as the longitudinal stretching and the lateral stretching is composed of a plurality of stages, stretching is performed at Ts at least in the last stage. The temperature Ts is determined by a differential scanning calorimeter (DSC). Specifically, Ts is determined as follows by second-scanning the composition using DSC to obtain melting points derived from components (1) and (2).

  The second scan means that a polypropylene composition is crystallized after being melted using DSC, and is subjected to thermal analysis using DSC after being kept at room temperature for 5 minutes. Specifically, 1) the polypropylene composition was heated to the melting temperature (230 ° C.), held at that temperature for 5 minutes, cooled to 30 ° C. at a temperature lowering rate of 10 ° C./min, held for 5 minutes, and then 2 ) Heat analysis is performed up to 230 ° C. at a temperature increase rate of 10 ° C./min.

  The polypropylene composition of the present invention is required to obtain a melting point peak derived from the component (1) or (2) by the thermal analysis. When the peak top temperature of the melting point on the highest temperature side derived from component (1) or (2) is Tm (° C.) in the second scan of the polypropylene composition by DSC, Ts satisfies 0 ≦ Ts−Tm ≦ 10. To be decided. When component (1) or (2) or both have a plurality of peaks, the peak top temperature on the highest temperature side is Tm.

  The temperature range of Ts is a state where most of the crystals derived from the components (1) and (2) of the polypropylene composition are melted together and the sheet shape can be maintained. Therefore, biaxial stretching becomes difficult when the temperature during biaxial stretching exceeds the upper limit, and transparency of the obtained sheet or the like decreases when the temperature is less than the lower limit. The deterioration of the transparency of the sheet or the like finally obtained is that when there are many unmelted components containing high melting point crystals in one of the components (1) or (2) during stretching, This is because the surface is uneven as a result of the component being stretched in a depressed state. In this invention, since a polypropylene composition is extended | stretched by said Ts, it is thought that the sheet | seat etc. which were excellent in transparency are obtained. However, it is not limited to this theory. The lower limit of Ts-Tm is 0 or more, preferably 2 or more, and more preferably 3 or more. Moreover, although the upper limit of Ts-Tm is 10 or less, 9 or less is more preferable.

3. Cooling The molded body obtained by biaxial stretching in the above temperature range has a smooth surface and high transparency as a result of stretching components (1) and (2) in a molten state. In this step, it is preferable to maintain the smooth surface state while cooling to maintain the transparency of the sheet or the like. Since crystals with a large size cause surface roughness, it is preferable to cool to a temperature at which crystals produced during cooling after biaxial stretching do not grow in order to maintain smoothness. Although the specific value is not limited, the cooling temperature is preferably 80 ° C. or lower, and more preferably 50 ° C. or lower. The cooling method is not particularly limited, and for example, a molded body obtained by biaxial stretching can be water-cooled or air-cooled. Furthermore, you may cool, after once hold | maintaining the molded object obtained by biaxial stretching at the temperature over 80 degreeC and Tm or less, for example, the temperature of 100-140 degreeC. However, from the viewpoint of work efficiency and transparency, it is preferable not to provide such a process.

4). Method for Producing Polypropylene Composition The polypropylene composition may be produced by any method. In the present invention, (A) a solid catalyst containing magnesium, titanium, halogen, and a dicarboxylic acid diester as an electron donor compound, ( It is preferable to produce using a catalyst containing B) an organoaluminum compound and (C) an external electron donor compound.

(1) Component (A): Solid catalyst Component (A) can be prepared by a known method, for example, by bringing a magnesium compound, a titanium compound and an electron donor compound into contact with each other.

As a titanium compound used for preparation of a component (A), the tetravalent titanium compound represented by general formula: Ti (OR) _{gX4 -g} is suitable. In the formula, R is a hydrocarbon group, X is a halogen, and 0 ≦ g ≦ 4. As titanium compounds, TiCl ₄ and more specifically, TiBr _4, titanium tetrahalides such as _{TiI 4; Ti (OCH 3)} Cl 3, Ti (OC 2 H 5) Cl 3, Ti (O n -C 4 H _{9) Cl 3, Ti (OC} 2 H 5) Br 3, Ti (OisoC 4 H 9) trihalide, alkoxy titanium such as _{Br 3; Ti (OCH 3)} 2 Cl 2, Ti (OC 2 H 5) 2 Cl ₂ , Di (halogenated alkoxytitanium) such as Ti (O _n —C ₄ H ₉ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₂ Br ₂ ; Ti (OCH ₃ ) ₃ Cl, Ti (OC ₂ H ₅ ) ₃ Cl _{, Ti (O n -C 4 H} 9) 3 Cl, Ti (OC 2 H 5) 3 monohalogenated trialkoxy titanium such as _{Br; Ti (OCH 3) 4} , Ti (OC 2 H 5) _{4, Ti (O n -C 4} H 9) 4 and the like tetraalkoxytitanium such. Among these, preferred are halogen-containing titanium compounds, particularly titanium tetrahalides, and more particularly preferred is titanium tetrachloride.

  Magnesium compounds used for the preparation of component (A) include magnesium compounds having a magnesium-carbon bond or magnesium-hydrogen bond, such as dimethylmagnesium, diethylmagnesium, dipropylmagnesium, dibutylmagnesium, diamylmagnesium, dihexylmagnesium, Examples include decylmagnesium, ethylmagnesium chloride, propylmagnesium chloride, butylmagnesium chloride, hexylmagnesium chloride, amylmagnesium chloride, butylethoxymagnesium, ethylbutylmagnesium, butylmagnesium hydride and the like. These magnesium compounds can also be used, for example, in the form of a complex compound with organic aluminum or the like, and may be liquid or solid. Further preferred magnesium compounds include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, magnesium fluoride; methoxy magnesium chloride, ethoxy magnesium chloride, isopropoxy magnesium chloride, butoxy magnesium chloride, octoxy magnesium chloride, and the like. Alkoxymagnesium halides; aryloxymagnesium halides such as phenoxymagnesium chloride and methylphenoxymagnesium chloride; alkoxymagnesiums such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-octoxymagnesium and 2-ethylhexoxymagnesium; phenoxy Magnesium, allyloxymagnesium such as dimethylphenoxymagnesium; Magnesium Ulin acids, such as carboxylic acid salts of magnesium such as magnesium stearate and the like.

The electron donor compound used for the preparation of component (A) is generally referred to as “internal electron donor”. In the present invention, the electron donor compound is preferably a dicarboxylic acid diester.

  A dicarboxylic acid is a compound having two carboxyl groups. Among dicarboxylic acid diesters, diesters of succinic acid, substituted succinic acid, phthalic acid, maleic acid, and substituted malonic acid are more preferable, and aromatic dicarboxylic acid diesters such as phthalic acid diester are particularly preferable. The alcohol used as the starting material for the ester is preferably an alcohol having 2 or more carbon atoms.

(2) Component (B): Organoaluminum compound The organoaluminum compound of the component (B) includes the following.
Trialkylaluminum such as triethylaluminum, tributylaluminum;
Trialkenyl aluminum such as triisoprenyl aluminum:
Dialkylaluminum alkoxides such as diethylaluminum ethoxide and dibutylaluminum butoxide;
Alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide;

Partially halogenated alkylaluminums such as alkylaluminum dihalogenides such as ethylaluminum dichloride, propylaluminum dichloride, butylaluminum dibromide and the like;
Dialkylaluminum hydrides such as diethylaluminum hydride, dibutylaluminum hydride;
Partially hydrogenated alkylaluminums such as alkylaluminum dihydrides such as ethylaluminum dihydride, propylaluminum dihydride;
Partially alkoxylated and halogenated alkylaluminums such as ethylaluminum ethoxychloride, butylaluminum butoxychloride, ethylaluminum ethoxybromide.

(3) Component (C): Electron Donor Compound The electron donor compound of component (C) is generally referred to as “external electron donor”. Such an electron donor compound is preferably an organosilicon compound. The following is mentioned as a preferable organosilicon compound.

  Trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyl Dimethoxysilane, diphenyldiethoxysilane, bis o-tolyldimethoxysilane, bism-tolyldimethoxysilane, bisp-tolyldimethoxysilane, bisp-tolyldiethoxysilane, bisethylphenyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxy Silane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyl Riethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyl Triethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, texyltrimethoxysilane, n-butyltriethoxysilane, iso-butyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chloro Triethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, 2-norbornanetrimethoxy Lan, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxysilane, vinyltris (β-methoxyethoxysilane), vinyltriacetoxysilane, Dimethyltetraethoxydisiloxane.

  Among them, ethyltriethoxysilane, n-propyltriethoxysilane, n-propyltrimethoxysilane, t-butyltriethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-butylethyldimethoxysilane, t-butylpropyldimethoxysilane, t-butylt-butoxydimethoxysilane, t-butyltrimethoxysilane, i-butyltrimethoxysilane, isobutylmethyldimethoxysilane, i-butylsec-butyldimethoxysilane, ethyl (perhydroisoquinoline 2- Yl) dimethoxysilane, bis (decahydroisoquinolin-2-yl) dimethoxysilane, tri (isopropenyloxy) phenylsilane, texyltrimethoxysilane, vinyltriethoxysilane, phenyltrie Xysilane, phenyltrimethoxysilane, vinyltributoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, i-butyli-propyldimethoxysilane, cyclopentyl t-butoxydimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, Cyclohexyl i-butyldimethoxysilane, cyclopentyl i-butyldimethoxysilane, cyclopentylisopropyldimethoxysilane, di-sec-butyldimethoxysilane, diethylaminotriethoxysilane, tetraethoxysilane, tetramethoxysilane, isobutyltriethoxysilane, phenylmethyldimethoxysilane, Phenyltriethoxylane, bis p-tolyldimethoxy Silane, p-tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylethyldimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, diphenyldiethoxysilane, methyl (3,3,3-trifluoropropyl) dimethoxy Silane and ethyl silicate are preferred.

(4) Polymerization Propylene and ethylene or C4 to C10-α-olefin as raw materials for component (1), and ethylene and C3 to C10-α-olefin as raw materials for component (2) are reacted in two or more. It is preferable to produce a polypropylene composition by polymerization using a vessel.

The polymerization may be carried out in liquid phase, gas phase or liquid-gas phase. The polymerization pressure is preferably in the range of 33 to 45 bar when carried out in the liquid phase and in the range of 5 to 30 bar when carried out in the gas phase. Conventional molecular weight regulators known in the art such as chain transfer agents (eg, hydrogen or ZnEt ₂ ) may be used.

  Moreover, as a method of obtaining the polypropylene composition of this invention, the method of performing using the superposition | polymerization device which has a gradient of monomer concentration and superposition | polymerization conditions is mentioned. In such a polymerization vessel, for example, a monomer in which at least two polymerization regions are connected can be used, and the monomer can be polymerized by gas phase polymerization. Specifically, in the presence of a catalyst, a monomer is supplied and polymerized in a polymerization region including a riser, and a monomer is supplied and polymerized in a downcomer connected to the riser. The polymer product is recovered while circulating. This method comprises means for completely or partially preventing the gas mixture present in the riser from entering the downcomer. Also, a gas and / or liquid mixture having a different composition from the gas mixture present in the riser is introduced into the downcomer. As the above polymerization method, for example, a method described in JP-T-2002-520426 can be applied.

  Component (1) or Component (2) can also be obtained by polymerizing the raw material monomer by a known method (for example, the method described in International Publication No. 2006/102155) using a metallocene catalyst or a half metallocene catalyst. Can be manufactured.

  The addition of the nucleating agent is performed by, for example, stirring the polymer obtained by polymerization and the nucleating agent together with an antioxidant with a Henschel mixer, Brabender, etc., and then melt blending at 180 ° C. to 280 ° C. using an extruder. be able to. The addition of the nucleating agent and the antioxidant may be performed using an extruder connected to a polymerization apparatus after undergoing polymerization, residual monomer removal, and a drying step.

  In particular, in the present invention, the polymerization powder and the nucleating agent may be melt-kneaded and mixed. Polymerized powder is a powdery polypropylene obtained after polymerization, after removal of residual monomers and drying. The polymer powder has an average particle size (by light scattering method) of 50 to 5,000 μm. By mixing the polymerization powder having a large surface area and the nucleating agent, the nucleating agent is dispersed well, and the transparency of the obtained sheet is further improved. In the present invention, a so-called master batch in which a high concentration nucleating agent is melt-kneaded with polypropylene may be mixed with the polypropylene resin at the time of sheet molding.

5. Applications The sheet or film of the present invention can be formed into a desired shape and used for various applications. For example, the sheet of the present invention is useful as a packaging material, a container material, particularly a food container. For example, a sheet or the like can be formed into a container by vacuum forming or the like. Since the obtained container is excellent in transparency and cold shock resistance, it is useful as a container for ice and ice confectionery, and a container for a cooled drink.

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto.
1. Preparation of polymer (1) Solid catalyst A solid catalyst used for polymerization was prepared by the following method. The solid catalyst is one in which Ti and diisobutyl phthalate as an internal donor are supported on MgCl ₂ .
Solid catalyst A: Prepared by the method described in Example 5 of EP 728769.
Solid catalyst B: prepared by the method described in Example 1 of European Patent No. 6749991.

(2) Polymer A
Using the above solid catalyst A, triethylaluminum (TEAL) as the organoaluminum compound and dicyclopentyldimethoxysilane (DCPMS) as the external electron donor compound, the weight ratio of TEAL to the solid catalyst is 20, and the weight ratio of TEAL / DCPMS is Contact was made at a temperature of 12 ° C. for 24 minutes. The resulting catalyst system was prepolymerized by holding it in liquid propylene in suspension for 5 minutes at 20 ° C. The obtained prepolymer is introduced into a first polymerization reactor of a polymerization apparatus equipped with a two-stage polymerization reactor in series to produce a propylene-ethylene copolymer, and ethylene is produced in the second polymerization reactor. A -1-butene copolymer was produced. This corresponds to mixing (polymerization blend) of the ethylene-1-butene copolymer and the propylene-ethylene copolymer from the first stage. During the polymerization, temperature and pressure were adjusted, and hydrogen was used as a molecular weight modifier. Further, the ratio of the polymer obtained in each stage was controlled by adjusting the residence time distribution in the first stage and the second stage.

The polymerization temperature and the molar ratio of the reactants are as follows: in the first stage reactor, the polymerization temperature, hydrogen concentration, and ethylene concentration are 70 ° C., 0.10 mol%, 0.84 mol%, and in the second stage reactor. The polymerization temperature, H2 / C2, and C4 / (C2 + C4) were 85 ° C., 0.27 molar ratio, and 0.48 molar ratio, respectively. The polymer obtained by the polymerization blend is a polypropylene composition comprising the following components (1) and (2).
Component (1): Propylene-ethylene copolymer containing 3.2% by weight of ethylene 82% by weight
Component (2): ethylene-1-butene copolymer containing 23% by weight of 1-butene 18% by weight

  Furthermore, 0.25 parts by weight of ADEKA STAB NA-71 (phosphate ester-based, manufactured by ADEKA Corporation) as a nucleating agent was added to 100 parts by weight of the polymer powder, and B225 manufactured by BASF was added as an antioxidant in an amount of 0. 2 parts by weight, 0.05 part by weight of calcium stearate manufactured by Tamnan Chemical Co., Ltd. was added as a neutralizer, and the mixture was stirred for 1 minute with a Henschel mixer and mixed. This mixture was extruded at a cylinder temperature of 230 ° C. using an NVC φ50 mm single screw extruder manufactured by Nakatani Machinery Co., Ltd., and the strand was cooled in water and then cut with a pelletizer to obtain a pellet-shaped propylene resin composition. It was. Polymer A is a polypropylene composition containing a nucleating agent.

(3) Polymer B1
The solid catalyst B, triethylaluminum (TEAL) and diisopropyldimethoxysilane (DIPMS) are added in an amount such that the weight ratio of TEAL to the solid catalyst is 11, and the weight ratio of TEAL / DIPMS is 3.2. For 5 minutes. The resulting catalyst system was prepolymerized by holding it in liquid propylene in suspension for 5 minutes at 20 ° C.

  After the obtained prepolymer is introduced into the polymerization reactor, hydrogen, propylene, and ethylene are fed to set the polymerization temperature, hydrogen concentration, and ethylene concentration to 75 ° C., 0.12 mol%, and 0.45 mol%, respectively. The propylene-ethylene copolymer was produced by adjusting the pressure. The polymer is component (1) and is a copolymer of polypropylene containing 1.7% by weight of ethylene. Polymer B1 was obtained in the same manner as Polymer A, except that 0.25 parts by weight of Millad 3988 (sorbitol, manufactured by Milliken Japan Co., Ltd.) was added as a nucleating agent to 100 parts by weight of the polymer powder. Polymer B1 is a composition obtained by adding a nucleating agent to component (1).

(4) Polymer B2
The polymer B2 is made of a polypropylene copolymer containing 1.7% by weight of ethylene, the same as the polymer B1, and is a composition that does not contain a nucleating agent. It was produced using the polymer powder in the same manner as the polymer B1, except that the nucleating agent was not added.

(5) Polymer C
Kernel KF370 manufactured by Nippon Polyethylene Co., Ltd. was used. Kernel KF370 is a homopolymer of ethylene produced by a high-pressure method using a metallocene catalyst and corresponds to component (2).

(6) Polymer D
Component (1) Polypropylene alone using a prepolymer prepared in the same manner as the prepolymer used in the polymerization of polymers B1 and B2, except that DCPMS was used instead of DIPMS as an external electron donor The polymer and component (2) ethylene-propylene copolymer were subjected to multistage polymerization to produce a polymer blend. In the first reactor, the polymerization temperature and hydrogen concentration are 70 ° C. and 0.10 mol%, respectively, and in the second reactor, the polymerization temperature, hydrogen concentration and C2 / (C2 + C3) are 85 ° C. and 1.13, respectively. The polymerization pressure was adjusted while adjusting the mol% to 0.48 molar ratio. Further, the ratio of the polymer obtained in each stage was controlled by adjusting the residence time distribution in the first stage and the second stage. The polymer D obtained by the polymerization blend is a polypropylene composition composed of the following components (1) and (2). Similarly to the polymer A, the polymer powder was used.
Component (1): Propylene homopolymer 80% by weight
Component (2): ethylene-propylene copolymer containing 51.5% by weight of propylene 20% by weight
The compositions of the polymers thus prepared are summarized in Table 1.

2. Manufacture of sheet Press molding polypropylene composition (preheating at 230 ° C for 5 minutes, repeating degassing operation between 0 and 60 MPa for 30 seconds, holding at 60 MPa for 3 minutes, then cooling at 30 ° C A plate having a thickness of 1.5 mm was obtained. This plate was cut into a size of 10.5 cm × 10.5 cm, heated for 120 seconds at the temperature shown in Table 2 using a Bruckner film stretching apparatus (KARO), and simultaneously stretched at a speed of 350 mm / second. The film was stretched in two directions, and biaxial stretching of 2.3 times by 2.3 times was performed. After stretching, the sheet was cooled to obtain a sheet.

3. Analysis and evaluation (1) MFR
According to JIS K 7210, the measurement was performed under conditions of a temperature of 230 ° C. and a load of 21.18 N.
(2) XSIV
2.5 g of sample was placed in a flask containing 250 ml of o-xylene (solvent) and stirred for 30 minutes at 135 ° C. while purging with nitrogen using a hot plate and a reflux apparatus to completely dissolve the sample. . The solution was then cooled at 25 ° C. for 1 hour. Filter the resulting solution using filter paper, collect 100 ml of the filtrate, transfer to an aluminum cup, etc., evaporate to dryness at 150 ° C. while purging with nitrogen, and allow to stand at room temperature for 30 minutes to dissolve xylene. Got the minute. Using an Ubbelohde viscometer, the intrinsic viscosity was measured in 135 ° C. tetrahydronaphthalene of the xylene solubles to obtain XSIV (dl / g).

(3) Stretchability A case where no problem such as breakage occurred during stretching was evaluated as good, and a case where a problem occurred was evaluated as poor.
(4) Transparency Based on ISO 14782, the haze measurement of the sheet | seat obtained as mentioned above was performed using Murakami Color Research Laboratory make and HM-150, and transparency was evaluated. At the same time, liquid paraffin (Liquid Paraffin Cat. No. 32033-00, manufactured by Kanto Chemical Co., Ltd.) was applied to both sides of the sheet with a brush in order to eliminate the influence of the unevenness of the sheet surface due to molding and cooling conditions. Haze measurement was performed. The former was defined as “all haze” and the latter as “internal haze”. Further, in order to see the contribution of the sheet surface, “external haze” (“total haze” − “internal haze”) was defined.

(5) Cold shock resistance A type D2 small square plate specified by JIS K7152 was prepared. Next, this plate was punched to prepare an A-shaped test piece defined by JIS K7216. Using the test piece, the embrittlement temperature was measured in accordance with JIS K7216, and the cold shock resistance was evaluated. The lower the embrittlement temperature, the better the cold shock resistance.

(6) Polymer or ethylene content of each component of polymer JNM LA-400 ( ^13C resonance) manufactured by JEOL Ltd. for a sample dissolved in 1,2,4-trichlorobenzene / deuterated benzene mixed solvent The frequency was calculated from the value measured by the ¹³ C-NMR method.
(7) Differential scanning calorimetry (DSC)
Using a Perkin Elmer diamond DSC, the second scan defined above was performed and measured.

[Example 1]
25% by weight of polymer A and 75% by weight of polymer B1 were mixed and kneaded using a 15 mmφ single screw extruder manufactured by Thermo Plastic Industry Co., Ltd. (kneading temperature 200 ° C.). Obtained. The obtained pellets were press-molded to produce a 10.5 cm × 10.5 cm × 1.5 mmt (thickness) plate. The section of the plate was heated at 10 ° C./min under a nitrogen atmosphere using a diamond DSC manufactured by Perkin Elmer and held at 230 ° C. for 5 minutes. Next, the temperature was lowered to 30 ° C. at 10 ° C./min. After maintaining at 30 ° C. for 5 minutes, the temperature was subsequently raised at 10 ° C./min and a second scan was performed, and the highest temperature side melting point Tm derived from component (1) and component (2) was measured. Tm was 152 ° C. From this value, the temperature Ts during biaxial stretching was set to 157 ° C. This Ts satisfies 0 ≦ Ts−Tm ≦ 10. As described above, a flat plate made of a polypropylene composition was biaxially stretched at 157 ° C., and then immersed in ice water and rapidly cooled to obtain a sheet. This sheet was evaluated, and as shown in Table 2, it was confirmed that it had excellent transparency and cold shock resistance.

[Example 2]
As a polypropylene composition, 35% by weight of polymer A and 65% of polymer B1 were mixed, and thereafter, biaxially stretched in the same process as in Example 1 to obtain a sheet. As in Example 1, it was confirmed that the film had excellent transparency and cold shock resistance.

[Example 3]
As a polypropylene composition, 45% by weight of polymer A and 55% by weight of polymer B1 were mixed, and then biaxially stretched in the same process as in Example 1 to obtain a sheet. As in Example 1, it was confirmed that the film had excellent transparency and cold shock resistance.

[Example 4]
As a polypropylene composition, 85% by weight of polymer A and 15% by weight of polymer B1 were mixed, and then biaxially stretched in the same process as in Example 1 to obtain a sheet. As in Example 1, it was confirmed that the film had excellent transparency and cold shock resistance.

[Example 5]
A polymer A alone was used as a polypropylene composition, and a 10.5 cm × 10.5 cm × 1.5 mmt (thickness) plate was produced by press molding. Thereafter, a sheet was obtained by biaxial stretching in the same process as in Example 1. As in Example 1, it was confirmed that the film had excellent transparency and cold shock resistance.

[Example 6]
The pellets of polymer B2 and polymer C are mixed at a weight ratio of 88:12, and Millad NX8000J (Nonitol-based, manufactured by Milliken Japan Co., Ltd.) is added as a nucleating agent to 100 parts by weight of polymer B2 and polymer C. 0.5 parts by weight was added and mixed to prepare a polypropylene composition. A sheet was obtained and evaluated in the same manner as in Example 1. As shown in Table 2, it was confirmed that the film had excellent transparency and cold shock resistance.

[Example 7]
After biaxial stretching, a sheet was produced and evaluated in the same manner as in Example 1 except that it was cooled to room temperature (23 ° C.) by air cooling. It was confirmed that the smooth surface state was maintained and, as shown in Table 2, it had excellent transparency and cold shock resistance.

[Example 8]
After biaxial stretching, a sheet was produced and evaluated in the same manner as in Example 1 except that it was kept at 130 ° C. for 2 minutes and then air-cooled to room temperature. As shown in Table 2, when compared with Example 1 which was immersed in ice water and rapidly cooled, the external haze was increased. As a result, the transparency of the obtained sheet was relatively inferior, but was within an acceptable range. The sheet obtained in this example was confirmed to have cold shock resistance.

[Comparative Example 1]
A sheet was produced and evaluated in the same manner as in Example 1 except that the polypropylene composition was biaxially stretched at 150 ° C. to obtain a sheet. The obtained sheet was remarkably inferior in transparency.

[Comparative Example 2]
A sheet was produced and evaluated in the same manner as in Example 6 except that the polypropylene composition was biaxially stretched at 150 ° C. to obtain a sheet. The obtained sheet was remarkably inferior in transparency.

[Comparative Example 3]
A polymer B1 which is a mixture of the component (1) and the nucleating agent was biaxially stretched at 157 ° C. to produce a sheet and evaluated. The obtained sheet was inferior in cold shock resistance.

[Comparative Example 4]
A sheet was produced and evaluated in the same manner as in Example 1 except that the sheet was obtained by biaxially stretching the polymer D at 162 ° C. (Ts−Tm = −4). The obtained sheet was remarkably inferior in transparency.

[Comparative Example 5]
A sheet was produced and evaluated in the same manner as in Example 1 except that the sheet was obtained by biaxially stretching the polymer D at 168 ° C. (Ts−Tm = 2). The obtained sheet was remarkably inferior in transparency.

[Comparative Example 6]
The same polypropylene composition as in Example 1 was biaxially stretched at 164 ° C. (Ts−Tm = 12), but could not be stretched.

  From the above, it is clear that the sheet of the present invention is excellent in transparency and cold shock resistance.

Claims (9)

Component (1) 70 to 97% by weight of a copolymer of propylene containing 1.0 to 5.0% by weight of ethylene or one or more C4 to C10-α-olefins;
Component (2) 3-30 wt% ethylene (co) polymer selected from the group consisting of ethylene polymers and copolymers of ethylene and one or more C3-C10-α-olefins; and Component (3 ) Including nucleating agents,
Melt Mass Furore wells (230 ° C., load 21.18 N) is 1.0~10g / 10 min,
A polypropylene composition having an XSIV (intrinsic viscosity of xylene solubles) of 0.5 to 2.0 dl / g,
A sheet or film obtained by a method including a step of biaxial stretching at a temperature Ts (° C.),
In the second scan of the polypropylene composition with a differential scanning calorimeter (DSC), when the peak top temperature of the melting point on the highest temperature side derived from the component (1) or (2) is Tm (° C.),
0 ≦ Ts−Tm ≦ 10 is satisfied,
Sheet or film.   The sheet or film of Claim 1 obtained by the method which further includes the process of cooling, maintaining the surface state of the molded object after the said biaxial stretching.   The sheet or film of Claim 1 or 2 which contains 0.05-1.0 weight part of said nucleating agents with respect to a total of 100 weight part of said component (1) and (2). The polypropylene composition contains propylene and ethylene or C4-C10-α-olefin as raw materials for component (1), and ethylene or ethylene and C3 to C10-α-olefin as raw materials for component (2). Using two or more reactors
(A) a solid catalyst containing magnesium, titanium, halogen, and a dicarboxylic acid diester as an electron donor compound,
The sheet according to any one of claims 1 to 3, which is a composition produced by a method comprising a step of polymerizing using a catalyst containing (B) an organoaluminum compound and (C) an external electron donor compound. the film.   The sheet or film according to any one of claims 1 to 4, wherein the component (2) is a copolymer of ethylene and one or more C4-C10-α-olefins.   The molded object which has a layer which consists of a sheet | seat or film in any one of Claims 1-5.   The secondary molded object formed by shape | molding the sheet | seat or film in any one of Claims 1-5. Component (1) 70 to 97% by weight of a copolymer of propylene containing 1.0 to 5.0% by weight of ethylene or one or more C4 to C10-α-olefins;
Component (2) 3-30 wt% ethylene (co) polymer selected from the group consisting of ethylene polymers and copolymers of ethylene and one or more C3-C10-α-olefins; and Component (3 ) Including nucleating agents,
Melt Mass Furore wells (230 ° C., load 21.18 N) is 1.0~10g / 10 min,
Preparing a polypropylene composition having an XSIV (intrinsic viscosity of xylene solubles) of 0.5 to 2.0 dl / g,
Biaxially stretching the polypropylene composition at a temperature Ts (° C.),
When the peak top temperature of the melting point on the highest temperature side derived from component (1) or (2) in the second scan in DSC of the polypropylene composition is Tm (° C.)
0 ≦ Ts−Tm ≦ 10 is satisfied,
A method for producing a sheet or film.   The manufacturing method of the sheet | seat or film of Claim 8 which further includes the process cooled, maintaining the surface state of the molded object after the said biaxial stretching.