JPH0912657A - Polypropylene film and sheet - Google Patents

Abstract

PURPOSE: To prepare a polypropylene film or sheet excellent in the balance between stiffness and impact resistance and in heat sealability and optical characteristics such as clarity and gloss. CONSTITUTION: This film or sheet is formed from a block copolymer comprising 35-90wt.% polypropylene block and 65-10wt.% propylene-another α-olefin copolymer block and has such properties that the crystallization temp. curve obtd. with a differential scanning calorimeter has a subpeak together with the main peak in the temp. range of 90-100 deg.C, the ratio of subpeak area to main peak area being 1.5-10%, and that the xylene-sols. content XIS (wt.%) at 25 deg.C and the ratio of subpeak area to main peak area SMA (%) satisfy the relation: 0.1XIS-1<=SMA.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene film and sheet which have excellent balance between rigidity and impact resistance, and excellent heat sealing properties and optical properties such as transparency and gloss.

[0002]

2. Description of the Related Art Polypropylene film is used as a packaging material in a wide range of fields such as industrial materials, foods and medical instruments because of its excellent mechanical properties, optical properties and packaging properties. Among the films, the film obtained from the block copolymer is particularly excellent in heat resistance, rigidity and impact resistance, and thus is suitable as a heat seal layer for packaging materials such as retort foods, PTPs and blister packs. Is used for. In recent years, such packaging materials have been required to have high characteristics, and in particular, a balance between rigidity and impact resistance and improvement in heat sealing characteristics have been demanded. Further, there is a problem that the film is opaque. Many improved block copolymers have been proposed to overcome these drawbacks. For example, JP-A-57-74312, JP-A-58-8717, and JP-A-59-11.
5312 and the like.

[0003]

However, these films are still inadequate in the balance between rigidity and impact resistance and heat-sealing properties, and inferior in optical properties such as transparency and gloss. there were. The present invention has been made in view of such circumstances, excellent balance of rigidity and impact resistance, heat seal characteristics and transparency,
The object is to provide a polypropylene film and sheet having excellent optical properties such as gloss.

[0004]

As a result of intensive studies, the present inventors have found that the above object can be achieved by a propylene block copolymer having specific physical properties, and the present invention is based on such findings. Has been completed. That is, the present invention relates to (A) polypropylene block 35-9.
A polypropylene film and sheet comprising 5% by weight and (B) a copolymer block of propylene and another α-olefin of 65 to 10% by weight and having the following physical properties. (A) In the crystallization temperature curve measured using a differential scanning calorimeter, the secondary peak has a secondary peak in the range of 90 to 100 ° C. other than the primary peak, and the ratio of the secondary peak area to the primary peak area is 1.5 to 10% (b) The xylene-extractable soluble component at 25 ° C. and the ratio of the secondary peak area to the main peak area satisfy the following formula: 0.1X _IS −1 ≦ SMA (wherein X _IS is xylene extractables (wt%), SMA
Represents the ratio (%) of the secondary peak area to the main peak area) Hereinafter, the present invention will be specifically described.

The polypropylene film and sheet of the present invention comprises a propylene block copolymer (hereinafter referred to as "BPP") comprising a polypropylene block (A) and a copolymer block (B) of propylene and another α-olefin. It is obtained by molding. Examples of the polypropylene block (A) of BPP include homopolypropylene or a random copolymer of propylene and another α-olefin (the α-olefin copolymerization ratio is less than 5 mol%).

On the other hand, as the (B) copolymer block,
Examples thereof include a random copolymer of propylene and other α-olefin (the α-olefin copolymerization ratio is 5 mol% or more). The content of the α-olefin in the component (B) is usually 30 to 80 mol%, preferably 32 to 78 mol%, and particularly preferably 35 to 75 mol%. The above-mentioned other α-olefins have 2 to 12 carbon atoms (however,
(Excluding 3), and specific examples include 1-butene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-.
1-Pentene, vinylcyclopentane, vinylcyclohexane and the like can be mentioned. These α-olefins may be used alone or in combination of two or more. Moreover, the ratio of the component (B) in the BPP is 10 to 10.
It is 65% by weight, preferably 12 to 63% by weight, particularly preferably 15 to 62% by weight. When the proportion of the component (B) is less than 10% by weight, the impact resistance is poor. On the other hand, if it exceeds 65% by weight, the surface of the molded product becomes sticky or the mechanical strength is deteriorated, such being undesirable.

Further, the film of the present invention has the following (a)
It is necessary to have the physical properties of and (b). (A) In the crystallization temperature curve measured using a differential scanning calorimeter, the secondary peak has a secondary peak in the range of 90 to 100 ° C. other than the primary peak, and the ratio of the secondary peak area to the primary peak area is It is 1.5 to 10%. The crystallization temperature curve measured using a differential scanning calorimeter is obtained by heating the film or sheet to 230 ° C., holding it for 5 minutes, and then cooling it to −30 ° C. at a cooling rate of 20 ° C./min. It is a thing. In the crystallization temperature curve thus measured, it is necessary to have a secondary peak in the range of 90 ° C to 100 ° C. An example of the crystallization temperature curve of the film of the present invention is shown in FIG.

The range of the secondary peak temperature is preferably 91 ° C to 99 ° C, particularly preferably 92 ° C to 98 ° C.
° C. If the secondary peak is less than 90 ° C, the effect of improving rigidity and transparency is poor. On the other hand, if the temperature exceeds 100 ° C, impact resistance,
Transparency is hindered, which is not preferable. The ratio of the secondary peak area to the main peak area (hereinafter referred to as "SMA")
Must be 1.5 to 10%, preferably 1.8
% To 9%, particularly preferably 2.0% to 8%. SM
If A is less than 1.5%, there is no effect of improving rigidity, whitening resistance and transparency. On the other hand, if the SMA exceeds 10%, transparency,
Impact resistance is impaired.

Further, (b) the xylene-extractable soluble component at 25 ° C. and the ratio of the secondary peak area to the main peak area must satisfy the following formula. 0.1 X _IS -1 ≤ SMA (where X _IS is xylene extractable solubles (wt%), SMA
Represents the ratio (%) of the secondary peak area to the main peak area) The above formula is preferably 0.18X _IS −1.8 ≦ SMA, particularly preferably 0.23X _IS −2.3 ≦ SMA.
It is. If the SMA does not satisfy the above formula, the improvement effect of the present invention is not exhibited, which is not preferable. Further, in the present invention, the 135 ° C. decalin solution viscosity [η] is 1.0 to 4.
When BPP of 0 dl / g is used, optical characteristics such as transparency and gloss are improved without impairing low temperature impact strength.

Further, in the film of the present invention, X _IS preferably has the following physical properties. (I) Average propylene content (F
P): 30 to 70 mol% (ii) Propylene content on the high propylene content side by a two-site model (P _P ): 50 to 80 mol% (iii) Proportion of P _H in the copolymer (P _f1 ): 0.2
0 to 0.60, (iv) Block property (CSD): 1.0 to 2.5

The two-site model of BPP of the present invention will be described below by taking the case where the component (B) is a propylene-ethylene copolymer as an example. FIG. 2 is a ¹³ C-NMR spectrum of a typical propylene-ethylene copolymer, and the spectrum gives 10 different peaks due to the difference in the chain distribution (arrangement of ethylene and propylene). The names of this chain are Carman, C, J, Horrington, R, A,
Wilkes, C, E; Macromolecules, Vol. 10, p536-544 (1977), and is named as shown in FIG. Such a chain can be expressed as a reaction probability (P), assuming a reaction mechanism of copolymerization, and thus the relative intensities of the peaks of (1) to (10) when the overall peak intensity is 1. P
Can be expressed as a stochastic equation by Bernoulli statistics.

For example, in the case of (1) Sαα, if the propylene unit is the symbol p and the ethylene unit is the symbol e, the possible chains are [pppp], [ppee], and [epp].
e], which are represented by reaction probabilities and are added together. The remaining peaks (2) to (10) can be obtained by formulating equations in the same manner, and optimizing P so that the peak intensity actually measured and those 10 equations are closest to each other. . The two-site model is a model that assumes this reaction mechanism. HNCHENG; Jounalof
Applied Polymer Sience, Vol.35 p1639-1650 (1988)
The definition is given in. That is, in a model in which propylene and ethylene are copolymerized using a heterogeneous catalyst, the propylene content (P _P ) of the copolymer (P _H ) generated at the active site that preferentially polymerizes propylene and ethylene are preferentially polymerized. Assuming that the propylene content (P ′ _P ) of the copolymer formed at the active sites that polymerize into the polymer is the parameter and the ratio of P _H to the copolymer (P _f1 ) is a parameter, the following Table 1
The probability equation shown in is obtained.

[0013]

[Table 1]

[0014] Therefore, the relative intensity of the ¹³ C-NMR spectrum as described above, P _P so that the probability equations shown in Table 1 are the same, by optimizing three parameters P _'P and P _f1 ,Desired.

The (i) average propylene content (FP) in the BPP of the present invention is determined by the following equation using the above three parameters. FP = P _P × P _f1 + P ′ _p × (1-P _f1 ) Block property (CSD) is the reactivity ratio of ethylene and propylene. This definition is edited by the Society of Polymer Science, “Copolymerization 1 Reaction Analysis. , P 5-13 ”published by Baifukan (1975). Calculation method is Soga, K, Park, J, R, Shion
o, T; Polymer Communications, Vol.32, No.10, p310 (1991)
Followed the method. That is, it was determined by the following formula using the intensity ratio of FIG. (CSD) = [(0.5 × (7) + 0.25 × (6) + 0.5 × (3)) × (1)]
/[0.5×(2)+(3))] ² The (i) FP thus obtained is preferably 30 to 70 mol%, more preferably 35 to 65 mol%. (ii) P _P is preferably 50 to 80 mol%, more preferably 55 to 50 mol%.
75 mol% is preferred. (iii) P _f1 is preferably 0.20 to 0.60, more preferably 0.25 to 0.55. (iv) CSD is preferably 1.0 to 2.5, and further 1.3
~ 2.0 is suitable.

As a method for obtaining BPP used in the present invention, for example, a solid catalyst containing a magnesium compound, a titanium compound, a halogen-containing compound and an electron-donating compound as essential components, or a general formula: TiXa.Yb
(Wherein X represents a halogen atom of Cl, Br, I, Y represents an electron-donating compound, a represents 3 or 4, and b represents an integer of 3 or less). Examples thereof include those polymerized using an improved polymerization catalyst obtained by washing with a halogen-containing compound and then washing with a hydrocarbon.

Such an improved polymerization catalyst is prepared using a magnesium compound, a titanium compound, a halogen-containing compound and an electron donating compound. Suitable magnesium compounds are magnesium halides such as magnesium chloride, magnesium bromide and magnesium iodide; alkoxy magnesium such as dimethoxy magnesium, diethoxy magnesium, dipropoxy magnesium, dibutoxy magnesium and diphenoxy magnesium. . Further, a material that forms magnesium halide during catalyst formation can also be used. These various magnesium compounds may be used alone or in combination of two or more.

As the titanium compound, titanium tetrachloride, titanium trichloride, titanium tetrabromide, and titanium halides such as titanium tetraiodide are suitable. Further, these various titaniums may be used alone or in combination of two or more. The halogen-containing compound, halogen is fluorine, chlorine, bromine, or iodine, preferably chlorine, the specific example depends on the catalyst preparation method, titanium halide such as titanium tetrachloride, silicon tetrachloride, tetraodor Examples thereof include silicon halide such as silicon halide, phosphorus trichloride, phosphorus halide such as phosphorus pentachloride, and the like. Depending on the catalyst preparation method, a halogenated hydrocarbon, a halogen molecule or a hydrohalic acid may be used.

The electron-donating compounds are generally oxygen-containing compounds, nitrogen-containing compounds, phosphorus-containing compounds, sulfur-containing compounds,
Examples thereof include silicon-containing compounds. Specifically, alcohols, phenols, ketones, aldehydes, organic acid esters, alkoxyesters, ketoesters,
Examples thereof include inorganic acid esters, ethers, amides, organic acid halides, organic acid anhydrides, amines, nitriles, thioethers, sulfuric acid esters, sulfonic acids, and silicon-containing compounds. Among these, organic acid esters are particularly preferable, and more specifically, phthalic acid esters such as ethyl phthalate butyl phthalate and 2-ethylhexyl phthalate can be exemplified. These electron donating compounds may be used alone or in combination of two or more.

The amount of each of the above-mentioned components used is arbitrary as long as the effects of the present invention are recognized, but the following ranges are generally preferred. The amount of titanium compound used is 0.0001 to 100 with respect to the amount of magnesium compound used.
The range of 0 is preferable, and the range of 0.01 to 100 is preferable. When a halogen compound is used as needed, the molar ratio is preferably 0.01 to 1000, and more preferably 0.1 to 100, with respect to the amount of the magnesium compound used. The amount of the electron-donating compound used is preferably in the range of 0.001 to 10 in terms of molar ratio with respect to the amount of the magnesium compound used, and preferably 0.1.
It is within the range of 01 to 5.

The solid catalyst used in the present invention is prepared by contacting or reacting with a magnesium compound, a titanium compound, an electron donating compound, and if necessary, an auxiliary agent such as a halogen-containing compound temporarily or stepwise. A conventionally known method for preparing a solid catalyst obtained by the above can be used. The following preparation methods are specific examples of known methods. (1) A method of contacting a magnesium halide with an electron-donating compound and a titanium compound as required. (2) A method of bringing a titanium halide compound and / or a halogen compound of silicon into contact with a solid component obtained by bringing magnesium halide into contact with tetraalkoxytitanium and a specific polymer silicon compound. (3) A method in which a magnesium compound is dissolved with tetraalkoxytitanium and an electron-donating compound, and the titanium compound is brought into contact with a solid component precipitated with a halogenating agent or a titanium halide compound. (4) A method in which alumina or magnesia is treated with a phosphorus halide compound, and a magnesium halide, an electron-donating compound, and a titanium halide compound are brought into contact therewith. (5) A method in which a Grignard reagent typified by an organomagnesium compound is allowed to act with a reducing agent or a halogenating agent, and then the electron donating compound and the titanium compound are brought into contact with each other. (6) A method of bringing a halogenating agent and / or a titanium compound into contact with an alkoxymagnesium compound in the presence or absence of an electron-donating compound. (7) A method in which a magnesium compound is dissolved in tetraalkoxytitanium, treated with a polymer silicon compound, and then treated with a halogen compound of silicon and an organometallic compound. (8) A method of treating a spherical magnesium compound / alcohol complex with an electron donating compound, a titanium halide compound, and the like. Among these preparation methods, the method (8) is preferable.

The solid catalyst prepared by the above method has the general formula TiX _a .Y _b (wherein X is Cl, Br, a halogen atom of I, a is 3 or 4, Y is an electron-donating compound, 0
≦ b ≦ 3) and the titanium compound represented by
The improved catalyst component of the present invention is prepared by treating with a halogen-containing compound one or more times and washing with hydrocarbons.
The general formula TiX _a · Y _b (wherein X is a halogen atom of Cl, Br, I, a is 3 or 4) is, for example, RSPCo.
utts, PCWailes; Adovan.Organometal.Chem., Vol.9, P
-135 (1970), 4th Edition New Experimental Chemistry Course 17 Inorganic Complexes / Chelate Complexes p. 35, The Chemical Society of Japan, Maruzen (1991), H.
K.Kakkoen, J.Pursiainen, TAPakkanen, M.Ahlgren, E.Ii
As described in skola; J. Organomet. Chem., Vol. 453, p175 (1993), it is generally known that an electron-donating compound easily forms a complex. TiX _a・ Y _b
Y (electron donating compound) may be the same as or different from the one used at the time of preparing the solid catalyst. Ti
When preparing X _a .Y _b , the electron donating compound may be used alone or in combination of two or more. The halogen-containing compound may be the same as or different from the one used when preparing the solid catalyst. The halogen-containing compounds may be used alone or in combination of two or more.

The temperature at which the solid catalyst is treated with TiX _a .Y _b is in the range of -30 ° C to 150 ° C, preferably 0 ° C to 100 ° C. The temperature for treating the solid catalyst with the halogen-containing compound is 0 ° C to 200 ° C, preferably 50 ° C to 15 ° C.
0 ° C. The amount of TiX _a · Y _b, relative to the titanium atom in the solid catalyst, often a range of 0.001 to 500, preferably in the range of 0.1 to 1000.

The treatment of the solid catalyst with TiX _a .Y _b and the halogen-containing compound can usually be carried out in an inert hydrocarbon medium. In this case, examples of the inert hydrocarbon medium used include aliphatic hydrocarbons such as pentane, hexane, heptane, octane and decane; aromatic hydrocarbons such as benzene, toluene and xylene. These inert hydrocarbon solvent may be used as the washing solvent of the olefin polymerization catalyst after treatment with TiX _a · Y _b and the halogen-containing compounds of the solid catalyst.

Among the improved polymerization catalysts thus prepared, those having the following powder physical properties are preferable. (1) Surface area: 100 to 300 m ² / g (2) Pore volume: 0.3 in the range of pores 2 nm to 40 nm
0 to 0.45 cc / g (3) Weight average particle size: 50 to 100 μm (4) Ratio of particle size 123 μm: 15% by weight or less (5) and ratio of particle size 87 μm or less: 35% by weight or more

The surface area is determined by the BET method (S. Brunauer, PHEmm
ett, E. Teller; J. Am. Chem. Soc., Vol. 60, p309 (1938). For the BET method, a commercially available measuring device, CARP, EBRA STRUMENTAZIONE, Sorp
Calculated by nitrogen gas adsorption method using tomatic Series 1800. The pore volume refers to the total volume of pores contained in the porous substance. Since such pores are not generally of a single diameter but are an aggregate of pores of various radii, the pore volume is obtained by obtaining the pore distribution. Mercury porosimetry (EWWashburn, Proc.Natl.Aca
d.Sci., Vol.7, p-115 (1921)). In this mercury injection method, mercury is injected into the pores of the catalyst,
The amount of mercury penetration into the pores can be determined as a function of pressure. For this measurement, the commercially available measuring device MI
Measured using CROMERITIS Auto Pore Model 9200.

The particle size is to measure the particle size distribution by diffraction pattern analysis. That is, the diffraction pattern analysis means that a laser beam expanded by a beam expander is applied to particles dispersed in a gas phase or a liquid phase, a diffraction pattern generated by the particles is condensed by a lens, and a detector is used. It is obtained from the intensity distribution of the Franhofer diffraction pattern projected and projected on this detector.

Regarding such an analysis method, Michael
Heuer, Kurt Leschonski: Results Obtained with a New
Instrument for the Measurment of Particle Size Dis
tributions from Diffraction Patterns. Part 2 (198
5) p7-13 and J. Fraunhofer: Brehungs und Frarbzers
treuungsverm gens verschiedener Glasarten.Gilberts
Annalen der Physik 56 (1987), p193-226 and the like. Specifically, using a commercially available JEOL Ltd. laser diffraction particle size distribution analyzer HELOS & RODOS,
Can be measured.

Such an improved polymerization catalyst is used in the production of the BPP of the present invention in combination with an organoaluminum compound and a stereoregularity improver described later. Typical organic aluminum compounds include trialkylaluminums such as trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, trihexylaluminum, trioctylaluminum, aluminoxanes such as methylaluminoxane, ethylaluminoxane and propylaluminoxane. Is mentioned. Such organic aluminium compounds may be used alone or in combination of two or more. As the stereoregularity improver, phenyltriethoxysilane, diphenyldimethoxysilane, di-n-propyldimethoxysilane, di-i-propyldimethoxysilane, di-t-butyldimethoxysilane, dicyclohexyldimethoxysilane, dicyclopentyldimethoxysilane, Cyclohexylmethyldimethoxysilane, thexyltrimethoxysilane, t-butyltrimethoxysilane,
Examples thereof include silicon compounds having a Si-O-C bond such as cyclohexyltrimethoxysilane, tetramethoxysilane, and tetraethoxysilane. These stereoregularity improvers may be used alone or in combination of two or more.

The polymerization method is not particularly limited and known methods can be used. It can be obtained by either a continuous method or a batch method, and the form of the polymerization reactor is not particularly limited. The BPP is an inert hydrocarbon such as hexane, heptane, kerosene, or liquefied α-such as propylene.
The polymerization is carried out at a room temperature to 130 ° C. by a slurry method in the presence of an olefin solvent or a gas phase polymerization method without a solvent. Preferably, it is performed in the range of 50 to 90 ° C. The polymerization pressure is in the range of ^{2 to} 50 Kg / cm ² . As the reactor in the polymerization step, a reactor generally used in this technical field can be appropriately used. For example, using a stirred tank reactor, a fluidized bed reactor or a circulation reactor, the polymerization operation can be carried out by any of a continuous system, a semi-batch system and a batch system. The obtained BPP slurry or powder is inactivated with alcohol, water or the like, if necessary, or after removing the residual catalyst, dried, and melt-mixed with the additive to be used.

When this BPP is further blended with a nucleating agent, one having excellent rigidity, heat resistance and impact strength can be obtained. In the field of synthetic resins, the nucleating agent refers to a substance that has the effect of growing a crystal by becoming a nucleus when added to a crystalline resin, and there are various substances. Examples thereof include metal salts of carboxylic acids, dibenzylidene sorbitol derivatives, metal phosphate salts, and inorganic fillers such as talc and calcium carbonate. Specific examples include sodium benzoate, aluminum adipate, pt-butyl aluminum benzoate, sodium thiophenecarboxylate, 1, 3, 2, 4
-Dibenzylidene sorbitol, 1,3,2,4-di-
(P-Methylbenzylidene) sorbitol, 1,3-p
-Chlorobenzylidene-2,4-p-methylbenzylidene sorbitol, sodium-bis- (4-t-butylphenyl) phosphonate, potassium-bis- (4-t
-Butylphenyl) phosphate, sodium-2,
Examples thereof include inorganic compounds such as 2′-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, talc, calcium carbonate and the like. These nucleating agents may be used alone or in combination of two or more. The effect of the present invention is remarkably preferable when the amount of the nucleating agent added is at least 0.05 to 0.5% by weight in the polyolefin resin composition. Preferably 0.08-
It is desirable to add 0.4% by weight, particularly preferably 0.1 to 0.35% by weight. However, since an inorganic compound such as talc has a smaller nucleating effect than the nucleating agents exemplified above, it is preferable to add 5 to 30% by weight. Preferably 7 to
28% by weight, particularly preferably 9 to 25% by weight.

For the polyolefin-based resin composition of the present invention, other additives conventionally used in thermoplastic resins (for example, antioxidants, weather resistance stabilizers, antistatic agents, lubricants, anti-blocking agents, anti-reflective agents) are used. Clouding agents, dyes, pigments, oils, waxes, etc.) can be added in appropriate amounts within the range not impairing the object of the present invention. Examples of such additives include 2,5-di-t-butylhydroquinone and 2,6-di-
t-butyl-p-cresol, 4,4′-thiobis-
(6-t-butylphenol), 2,2-methylene-bis (4-methyl-6-t-butylphenol), octadecyl-3- (3 ', 5'-di-t-butyl-1'-hydroxyphenyl) propinate , 4,4′-thiobis- (6-butylphenol), as a UV absorber ethyl-2-cyano-3,3-diphenyl acrylate,
2- (2'-hydroxy-5-methylphenyl) benzotriazole, 2-hydroxy-4-octoxybenzophenone, dimethyl phthalate as a plasticizer, diethyl phthalate, wax, liquid paraffin, phosphate ester,
Antistatic agents such as pentaerythritol monostearate, sorbitan monopalmitate, sulfated oleic acid,
Polyethylene oxide, carbon wax, ethylene bis stearamide as a lubricant, butyl stearate, etc.,
Carbon black, phthalocyanine, quinacridone, indoline, azo pigments, titanium oxide, red iron oxide, etc. as colorants, glass fiber, asbestos as fillers,
Examples thereof include mica, ballastonite, calcium silicate, aluminum silicate, calcium carbonate and the like. Many other high molecular compounds can also be blended to such an extent that the effects of the present invention are not impaired.

As a method for producing the composition, there is a method in which PP is melt-kneaded with a nucleating agent together with other additives. Specifically, conventionally known mixing methods, for example, each component is mixed using a ribbon blender, Henschel, and further kneader, mixing roll, Banbury mixer,
A method of melt mixing using an extruder or the like can be mentioned. The melt kneading temperature is preferably in the range of 170 to 280 ° C. The range of 190 to 260 ° C. is preferable. Particularly preferably, it is in the range of 200 to 250 ° C. On the other hand, each component may be directly supplied to a molding machine and molded.
Melt index of the above resin composition (MFR, JIS-K721
0, a load of 2.16 Kg and a temperature of 230 ° C.) is not particularly limited and is selected depending on the molding method, but a range of 0.1 to 250 (g / 10 minutes) is appropriate depending on the extrusion molding.

The film / sheet of the present invention is produced by a method which is usually used industrially using the above resin composition, for example, a cast film (T die) molding method, an inflation film molding method and a sheet molding method. Further, a surface treatment such as a heat treatment as a post-treatment, a slight stretching operation, a corona discharge treatment, or a flame treatment may be performed. Further, the film of the present invention is effective as a heat-sealing layer of a composite film and also as a base layer. Therefore, it can be used not only as a single body but also as a stack of other materials. As a laminating method in the case of laminating, a so-called dry laminate molding method or a sandwich lamination method of laminating using a dry laminate adhesive such as a polyurethane type, a polyester type polyacrylic type or a coextrusion laminating method or a coextrusion method (feed block method) is used. , Multi-manifold method), co-injection molding method, co-extrusion pipe molding method and the like. The multilayer laminate thus obtained is then subjected to a reheating and stretching operation using a vacuum forming machine, a pressure forming machine, a stretch blow molding machine, or a single layer of the above-mentioned multilayer laminate or resin composition. The molded product can be subjected to a heat stretching operation using a uniaxial or biaxial stretching machine.

[0035]

The present invention will be described in more detail with reference to the following examples. The method and apparatus for measuring each physical property in the present invention are shown below. (1) Ethylene content Based on the method by ¹³ C-NMR method reported by CJ Carman et al. (Macromolecules, 10, 537 (1977). (2) Table 1 according to MFR JIS K7210, conditions I went to 14.
The apparatus used was a melt indexer manufactured by Takara Corporation. (3) Xylene Extractable Soluble Content at 25 ° C. (X _IS ) Once BPP was once dissolved in ortho-xylene at 135 ° C., it was cooled to 25 ° C. to precipitate a polymer, and the soluble content was X.
_IS (% by weight) was used. (4) Crystallization temperature and ratio of secondary peak area to main peak area (SMA) Equipment: PERKIN-ELMER DSC7 type Sample weight: about 3 to 5 mg Measurement method: The sample was heated to 230 ° C. After holding for a minute, the temperature was lowered to −30 ° C. at a rate of 20 ° C./minute to obtain a crystallization temperature curve. From the obtained crystallization temperature curve, the main peak temperature, the secondary peak temperature and the ratio of the secondary peak area to the main peak area (SMA) were determined.

(5) Analysis by 2-site model BPP was mixed in a mixed solvent of 1,2,4-trichlorobenzene / heavy benzene so that the polymer concentration became 10% by weight.
Dissolve by heating to 30 ° C. Then, ¹³ C-NMR spectrum was measured with the following apparatus and conditions, and the respective signals were obtained by Macromolecules, 13, 267 of A. Zambelli et al.
Attributable in (1980). Measuring device: JEOL Ltd. JNM-GSX400 ( ¹³ C nuclear resonance frequency 100 MHz) Pulse width: 8.0 μsec Pulse repetition time: 5.0 sec Accumulation frequency: 20000 times Solvent: 1,2,4-trichlorobenzene / heavy Mixed solvent of benzene (75/25% by volume) Internal standard: Hexamethyldisiloxane Sample concentration: 300 mg / 3.0 ml Solvent measurement temperature: 120 ° C. Next, a two-site model is analyzed to determine FP, P _P , P _f1.
And CSD were determined.

(6) Particle size distribution measuring device for polymerization catalyst: HELOS & RODOS dispersion manufactured by JEOL Ltd .: Hexane Focal length: 100 mm (7) Tensile elastic modulus Measured under conditions of a tensile speed of 5 mm / min according to JIS K7127. . (8) Film impact strength The film was measured using a pendulum type film impact tester (1/2 hemisphere) manufactured by Toyo Seiki Seisakusho under the conditions of temperature 23 ° C and -5 ° C. (9) Heat seal strength Using a heat sealer manufactured by Tester, at a temperature of 155 ° C,
A 15 mm wide strip-shaped test piece that was heat-sealed under a pressure of 2 kg / cm ² and a sealing time of 1 second was subjected to T-type peeling at a peeling speed of 300 mm / min using a tensile tester manufactured by Olintec.

(10) Surface gloss (gloss) The surface gloss (gloss) of the film was measured using a VG-1D type gloss meter manufactured by Nippon Denshoku Industries Co., Ltd. according to JIS K7205. (11) Haze (Transparency) Based on JIS K7105, total haze and internal haze were measured. The internal haze was measured by immersing it in liquid paraffin. (12) Retort characteristics After forming a four-sided sealed bag at a temperature of 160 ° C using the heat sealer, a retort treatment was performed at 135 ° C for 30 minutes using an RCS40T type retort tester manufactured by Hisaka Seisakusho. The heat seal strength retention rate was calculated by the following formula. Retention rate (%) = Seal strength after treatment / Seal strength before treatment ×
In addition, the fusion state of the films in the treated bag was visually evaluated in the following three stages. ○ ・ ・ ・ ・ No fusion was observed △ ・ ・ ・ ・ Some fusion was observed × ・ ・ ・ ・ Fusion was remarkable

(Example of Preparation of Polymerization Catalyst) Preparation of Solid Catalyst 56.8 g of anhydrous magnesium chloride was added to anhydrous ethanol 1
00g, Vaseline oil CP15N manufactured by Idemitsu Kosan Co., Ltd.
500 ml and 500 ml of silicone oil KF96 manufactured by Shin-Etsu Silicone Co., Ltd. were completely dissolved at 120 ° C. under a nitrogen atmosphere. This mixture is manufactured by Tokushu Kika Kogyo Co., Ltd.
The mixture was stirred for 2 minutes at 120 ° C. and 5000 revolutions / minute using a TK homomixer manufactured by KK. While maintaining stirring, the mixture was transferred into 2 liters of anhydrous heptane so as not to exceed 0 ° C.
The obtained white solid was thoroughly washed with anhydrous heptane, vacuum dried at room temperature, and partially deethanolized under a nitrogen stream.

The obtained MgCl ₂ .1.2C ₂ H ₅ OH
30 g of the spherical solid of was suspended in 200 ml of anhydrous heptane. 500 ml of titanium tetrachloride was added dropwise over 1 hour while stirring at 0 ° C. Next, when heating started to 40 ° C., 4.96 g of diisobutyl phthalate was added, and the temperature was raised to 100 ° C. in about 1 hour. 2 at 100 ° C
After reacting for a period of time, the solid portion was collected by hot filtration.
Then, 500 ml of titanium tetrachloride was added to this reaction product, and the mixture was stirred and then reacted at 120 ° C. for 1 hour. After completion of the reaction, the solid portion was collected again by hot filtration and washed with 1.0 liter of hexane at 60 ° C. 7 times and 1.0 liter of hexane at room temperature 3 times. The titanium content in the obtained solid catalyst component was measured and found to be 2.36% by weight.

TiCl ₄ [C ₆ H ₄ (COOiC ₄ H
₉ ) ₂ ] Preparation A solution of 19 g of titanium tetrachloride in 1.0 liter of hexane was added to diisobutyl phthalate: C ₆ H ₄ (COOiC ₄
About 27.8 g of H ₉ ) _{2 was} added to about 30 while maintaining the temperature of 0 ° C.
Dropped in minutes. After completion of the dropping, the temperature was raised to 40 ° C. and the reaction was performed for 30 minutes. After the reaction was completed, the solid portion was collected and hexane 50 was added.
The product was washed 5 times with 0 ml to obtain the desired product.

Preparation of Improved Polymerization Catalyst 20 g of the solid catalyst obtained above was added to 300 ml of toluene.
And the TiCl obtained above at a temperature of 25 ° C.
₄ [C ₆ H ₄ (COOiC ₄ H ₉ ) ₂ ] was stirred and washed for 1 hour, and the solid portion was collected by hot filtration, and then the reaction product was washed with 500 ml of toluene at 90 ° C. three times and hexane at room temperature. It was washed 3 times with 500 ml. The titanium content in the obtained solid catalyst component was 1.78% by weight, and the surface area and pore volume of this improved polymerization catalyst were measured.
It was as follows. Surface area: 165 m ² / g Pore volume: 0.31 cc / g in the range of pores ² to 40 nm Weight average particle diameter: 86.1 μm Particle diameter 123 μm or more ratio: 5.0% by weight Particle diameter 87 μm or less ratio: 51.5% by weight

Preliminary Polymerization Under a nitrogen atmosphere, in an autoclave having an internal volume of 3 liters, 500 ml of n-heptane, 6.0 g of triethylaluminum, 0.39 of dicyclopentyldimethoxysilane.
g and 10 g of the improved polymerization catalyst obtained above were added and stirred at a temperature range of 0 to 5 ° C for 5 minutes. Next, propylene was fed into the autoclave so that 10 g of propylene was polymerized per 1 g of the improved polymerization catalyst, and the temperature was adjusted to 0 to 5 ° C.
Was pre-polymerized in the temperature range of 1 hour. The obtained prepolymerized solid catalyst was further washed with 500 ml of n-heptane three times to obtain a final prepolymerized solid catalyst.

Example 1 (a) First stage: Polymerization of homopolypropylene In a nitrogen atmosphere, 2.0 g of the above prepolymerized solid catalyst, 11.4 g of triethylaluminum and dicyclopentyldimethoxy were placed in an autoclave equipped with a stirrer and having an internal volume of 60 liters. 6.84 g of silane was added, then 18 kg of propylene,
Hydrogen was charged so as to be 14000 molppm with respect to propylene, the temperature was raised to 70 ° C., and polymerization was carried out for 1 hour. After 1 hour, unreacted propylene was removed to terminate the polymerization. (B) Second stage: Polymerization of propylene-ethylene copolymer After completion of the first stage polymerization, liquid propylene was removed and ethylene / propylene = 40/60 at a temperature of 75 ° C.
(Molar ratio) mixed gas 2.2Nm ³ / hour, hydrogen 20N
Copolymerization was carried out for 40 minutes at a feed rate of L / hour. After 40 minutes, unreacted gas was removed to terminate the polymerization. As a result, 7.3 Kg of propylene block copolymer was obtained. Table 1 shows the physical properties of the obtained BPP and the analysis results of the two-site model.

Further, 0.05 wt% of di-t-butyl-p-cresol and pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-) were added to the obtained BPP.
Hydroxyphenyl) propionate] and 0.10% by weight of calcium stearate are mixed, and a super mixer (SMV20 manufactured by Kawata Manufacturing Co., Ltd.) is added.
Pellet). About the obtained pellets, a film having a thickness of 60 μm was formed at a molding temperature of 230 ° C. and a cooling roll temperature of 40 ° C. using a 40 mmΦ cast molding machine manufactured by Yoshii Iron Works. Various physical properties of each of the obtained films were measured. Table 3 shows the above results.

Examples 2 to 4 In the same manner as in Example 1, polymerization was carried out by changing the amount of hydrogen charged during the polymerization, the second stage polymerization time, and the amount of ethylene. As a result, the products shown in Table 2 were obtained. Also, various physical properties were measured in the same manner as in Example 1. Table 3 shows the results.

Example 5 The same procedure as in Example 1 was carried out except that propylene and ethylene were supplied to the first stage for polymerization. A polypropylene block having an ethylene content of 2.4% by weight was obtained in the first stage.
The ethylene content was measured by sampling an ethylene content measurement sample at the time when the first-stage polymerization was completed. The results of various physical properties are shown in Tables 2 and 3.

Comparative Example 1 The procedure of Example 1 was repeated, except that the solid catalyst prepared above was used as the catalyst and the amount of hydrogen charged was 9500 molppm. The results are shown in Tables 2 and 3. The powder physical properties of the catalyst were as follows. Surface area: 206 m ² / g Pore volume: 0.36 cc / g in the range of pores ² to 40 nm Weight average particle size: 93.5 μm Particle size 123 μm or more ratio: 16.5% by weight Particle size 87 μm or less ratio: 34.1% by weight

Comparative Example 2 In a nitrogen atmosphere, in an autoclave with an internal volume of 60 liters equipped with a stirrer, 6.0 g of AA type titanium trichloride manufactured by Tosoh Akzo Co., 23.5 g of diethylaluminum chloride was used.
Then, 18 kg of propylene and hydrogen were charged so that the concentration would be 8000 mol ppm with respect to propylene.
The temperature was raised to 0 ° C., and then the same procedure as in Example 1 was performed. The results are shown in Tables 2 and 3. The powder physical properties of the catalyst were as follows. Surface area: 41 m ² / g Pore volume: 0.25 cc / g in the range of pores ² to 40 nm Weight average particle diameter: 5.6 μm Ratio of particle diameter 123 μm or more: 0.5% by weight Ratio of particle diameter 87 μm or less: 93.2% by weight

Comparative Example 3 Homopolypropylene 8 with MFR of 8.4 g / 10 minutes
A film was prepared and physical properties were evaluated in the same manner as in Example 1 except that a resin mixture consisting of 0 parts by weight and 20 parts by weight of ethylene-propylene rubber having an ethylene content of 81 mol% was used. The results are shown in Tables 2 and 3.

[0051]

[Table 2]

[0052]

[Table 3]

[0053]

EFFECTS OF THE INVENTION The film and sheet of the present invention have excellent balance between rigidity and impact strength, and have excellent optical properties such as transparency and gloss and retort properties.
It is useful because it can be used as a packaging material for various fields such as medical device materials.

[Brief description of the drawings]

FIG. 1 is an example of a crystallization temperature curve of the polypropylene film of the present invention.

FIG. 2 is an example of a nuclear magnetic resonance spectrum of a propylene-ethylene copolymer.

FIG. 3 is an example showing names of respective carbons derived from a chain distribution of a propylene-ethylene copolymer.

Claims (3)

[Claims] 1. (A) Polypropylene block 35-
A polypropylene film and sheet comprising 95% by weight and (B) a copolymer block of propylene and another α-olefin of 65 to 10% by weight and having the following physical properties. (A) In the crystallization temperature curve measured using a differential scanning calorimeter, the secondary peak has a secondary peak in the range of 90 to 100 ° C. other than the primary peak, and the ratio of the secondary peak area to the primary peak area is 1.5 to 10% (b) The xylene-extractable soluble component at 25 ° C. and the ratio of the secondary peak area to the main peak area satisfy the following formula: 0.1X _IS −1 ≦ SMA (wherein X _IS is xylene extractables (wt%), SMA
Represents the ratio (%) of the secondary peak area to the main peak area) 2. The polypropylene film and sheet according to claim 1, wherein the xylene-extractable soluble matter at 25 ° C. has the following physical properties. (I) Average propylene content (F
P): 30 to 70 mol% (ii) Propylene content on the high propylene content side by a two-site model (P _P ): 50 to 80 mol% (iii) Proportion of P _H in the copolymer (P _f1 ): 0.2
0 to 0.60, (iv) Block property (CSD): 1.0 to 2.5 3. A solid catalyst containing a magnesium compound, a titanium compound, a halogen-containing compound, and an electron-donating compound as essential components is further added to a compound represented by the general formula TiXa.Yb (wherein X:
Is a halogen atom of Cl, Br, I, Y is an electron-donating compound, a is 3 or 4, and b is an integer of 3 or less.) And then washed with a halogen-containing compound. Obtained by further washing with hydrocarbon,
The polypropylene film and sheet according to claim 1 or 2, which is obtained by molding a propylene block copolymer obtained by polymerization using an improved polymerization catalyst having the following physical properties. (1) Surface area: 100 to 300 m ² / g (2) Pore volume: 0.3 in the range of pores 2 nm to 40 nm
0 to 0.45 cc / g (3) Weight average particle size: 50 to 100 μm (4) Ratio of particle size 123 μm or more: 15% by weight or less (5) Ratio of particle size 87 μm or less: 35% by weight or more