JPH1086218A - Blown film and method for producing the film - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a light-shielding film having a high strength and a good balance of vertical and horizontal strengths. SOLUTION: (a) The density is 0.86 to 0.97 g / c.
m ³ , (b) melt flow rate 0.01 to 100 g /
10 minutes, (c) molecular weight distribution (Mw / Mn) is 1.5 to
5.0. (D) An inflation film made of an ethylene (co) polymer satisfying a requirement that a composition distribution parameter Cb is 2.00 or less, and a crystal grain of a concentric block made of an aggregate of crystal lamellas on the film surface. 0.5 to 8 in diameter
μm, tear strength of film is 20K in machine direction (MD)
A blown film having a gf / cm or more, a lateral (TD) direction of 60 kgf / cm or more, and an external haze of the film of 20% or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inflation film suitable for use as various packaging bags and packaging materials and a method for producing the film, and particularly to a high strength, vertical and
The present invention relates to a translucent pearl-like blown film having a good lateral strength balance and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, high pressure radical process low density polyethylene (LDPE) has been widely used as an inflation film used as various packaging bags and packaging materials. However, although LDPE is excellent in optical properties such as transparency, it has a drawback that mechanical properties such as impact resistance and tear strength are inferior. On the other hand, high-density polyethylene (HDPE) obtained by ionic polymerization using a Ziegler catalyst,
Linear low-density polyethylene (LLDPE) and very low-density polyethylene (VLDPE) have a linear molecular structure,
Compared with the LDPE, it has an advantage of being excellent in mechanical properties such as impact resistance and tear strength. In particular, a density of 0.
LLDPE of 94 g / cm ³ or less is composed of a copolymer of ethylene and a comonomer α-olefin having 3 to 20 carbon atoms, and is superior in flexibility, impact resistance, creep resistance and the like as compared with HDPE. Further, since they are superior in impact resistance, creep resistance and the like as compared with LDPE, they are widely used in the field of packaging materials, especially films and laminations. However, LLDPE as a film material
Has a problem that the fluidity at the time of melting is inferior to HDPE and LDPE, and molding processability is poor.
That is, LLDPE has an extremely high Newton property at the time of flow, has a large shear stress in a high shear rate region, easily causes melt fracture at the time of molding, is inferior in high-speed moldability, and requires energy required for flow at the time of molding. There is a problem of being large. Also, LLDPE
Has a drawback that the resistance at the time of melt elongation deformation, that is, the melt tension (melt tension) is extremely small, so that bubbles cannot be stably expanded during inflation molding. In order to solve such a problem, a film is formed by blending 10 to 30% by weight of LDPE with LLDPE. However,
When LDPE is blended with LLDPE, fluidity or melt tension is slightly improved, but LLDPE inherently has due to remarkable progress of crystal orientation in the flow direction and miscibility and dispersibility of both polyethylene molecules. There is a new problem that mechanical strength and strength balance in the vertical and horizontal directions cannot be obtained. In addition, there is a demand for a light-shielding film in applications such as protecting precision machine parts, medical products, and the like, and in the field of protecting privacy. Conventionally, as such a light-shielding film, a film containing a pigment such as TiO ₂ or carbon black has been provided.
In fields such as medical products (high-tech, microelectronics, multimedia, biomedical, etc.), the tendency to spread these additives, which cause contamination (contamination, contamination, etc.), into resins is spreading.
There is a demand for the development of a light-shielding film that does not contain these additives.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an excellent balance between high strength and strength in the vertical and horizontal directions, and has a pearl-like and translucent light-shielding property. An object of the present invention is to provide an inflation film and a method for producing the film.

[0004]

The first aspect of the present invention is (a).
Density 0.86 to 0.97 g / cm ³ , (b) melt flow rate 0.01 to 100 g / 10 min, (c) molecular weight distribution (Mw / Mn) 1.5 to 5.0, (d) A blown film made of an ethylene (co) polymer satisfying a requirement of a composition distribution parameter Cb of not more than 2.00, wherein a crystal grain size of a concentric mass made of an aggregate of crystal lamella on the film surface is 0.5 to 0.5%. An inflation film characterized in that the film has a tear strength of 8 μm, a tensile strength of the film of 20 kgf / cm or more in the longitudinal (MD) direction, 60 kgf / cm or more in the transverse (TD) direction, and an external haze of the film of 20% or more. The second aspect of the present invention is the following (A) to
A blown film made of an ethylene (co) polymer satisfying the requirement (f), wherein the concentric mass made of an aggregate of crystal lamella on the film surface has a crystal grain size of 0.5.
８8 μm, the tear strength of the film is 2 in the machine direction (MD).
0 kgf / cm or more, 60 kgf / c in the transverse (TD) direction
m or more, and an external haze of the film is 20% or more. (B) Density 0.86 to 0.97 g / cm ³ (b) Melt flow rate 0.01 to 100 g / 10 min (c) Molecular weight distribution (Mw / Mn) 1.5 to 5.0 (d) The composition distribution parameter Cb is 1.08 to 2.00 (e) Substantially a plurality of peaks in an elution temperature-elution amount curve by a continuous heating elution fractionation method (TREF) (f) orthodichlorobenzene at 25 ° C (ODC
B) Soluble content X (wt%), density d and MFR (melt flow rate) satisfy the following relationship: a) d-0.008 log MFR ≧ 0.93 X <2.0 b) d −0.008 log When MFR <0.93 X <9.8 × 10 ³ × (0.9300−d + 0.008 log
MFR) ² +2.0 A third aspect of the present invention is that the ethylene (co) polymer is composed of an organic cyclic compound having at least a conjugated double bond and an organic cyclic compound having at least a conjugated double bond.
An inflation film characterized by using ethylene or an ethylene (co) polymer obtained by (co) polymerizing ethylene and an α-olefin in the presence of a catalyst containing a group IV transition metal compound. A fourth aspect of the present invention is that, using an ethylene (co) polymer satisfying the following requirements (a) to (d), a take-up speed of 20 to 120 m / min, a blow-up ratio of 2 to 4, a frost line of 100 to An object of the present invention is to provide a method for producing an inflation film, wherein the inflation film is formed at 700 mm. (B) Density 0.86 to 0.97 g / cm ³ (b) Melt flow rate 0.01 to 100 g / 10 min (c) Molecular weight distribution (Mw / Mn) 1.5 to 5.0 (d) The composition distribution parameter Cb is 2.00 or less. In the fifth aspect of the present invention, the ethylene (co) polymer is composed of an organic cyclic compound having at least a conjugated double bond and an organic cyclic compound having at least a conjugated double bond.
A method for producing an inflation film characterized by using ethylene or an ethylene (co) polymer obtained by (co) polymerizing ethylene and an α-olefin in the presence of a catalyst containing a group IV transition metal compound It is.

Hereinafter, the present invention will be described in more detail. The ethylene (co) polymer of the present invention is an ethylene homopolymer or a copolymer of ethylene and an α-olefin, and is a (co) polymer of ethylene or ethylene and an α-olefin having 3 to 20 carbon atoms. (A) to-
(B) The density is 0.86 to 0.97 g / cm ³ (b) The melt flow rate is 0.01 to 100 g / 10 min (c) The molecular weight distribution (Mw / Mn) is 1.5 to 5.0 (d) An ethylene (co) polymer satisfying a composition distribution parameter Cb of 2.00 or less.

[0006] The ethylene (co) polymer of the present invention has an α-
Olefins are those having 3 to 20 carbon atoms, preferably 3 to 1 carbon atoms.
2, specifically propylene, 1-butene,
Examples thereof include 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, and 1-dodecene. In addition, the content of these α-olefins,
Usually 30 mol% or less in total, preferably 3 to 20 mol%
It is desirable to select within the following range.

The (a) density of the ethylene (co) polymer of the present invention is 0.86 to 0.97 g / cm ³ , preferably 0.89 to 0.95 g / cm ³ , more preferably 0.90 to 0.95 g / cm ³ . 0.94 g / cm ³ , and (b) melt flow rate (hereinafter referred to as MFR) in the range of 0.01 to 10
The range is 0 g / 10 min, preferably 0.1 to 50 g / 10 min, and more preferably 0.5 to 40 g / 10 min.
Those with a density of less than 0.86 g / cm ³ are too soft,
The rigidity and heat resistance are poor, and the anti-blocking properties are poor. ^{On the other hand} , if it exceeds 0.97 g / cm ³ , it is too hard, and the tear strength, impact strength and the like become low. MFR is 0.0
If it is less than 1 g / 10 minutes, the workability is poor, and 100 g / min.
If it exceeds 10 minutes, the strength becomes weak.

[0008] (C) M of the ethylene (co) polymer of the present invention
w / Mn ranges from 1.5 to 5.0, preferably 1.6.
To 4.5, more preferably from 1.7 to 4.0. If the Mw / Mn is less than 1.5, the moldability is poor, and if it exceeds 5.0, the impact resistance is poor. In general, the molecular weight distribution (Mw / Mn) of an ethylene (co) polymer is determined by determining the weight average molecular weight (Mw) and the number average molecular weight (Mn) by gel permeation chromatography (GPC) and calculating the ratio (Mw / Mn). ) Can be calculated.

The (d) composition distribution parameter (Cb) of the ethylene (co) polymer of the present invention is 2.00 or less. And the low-molecular-weight or high-branching-degree components ooze out onto the resin surface, resulting in a hygienic problem.

The method for measuring the (d) composition distribution parameter (Cb) of the ethylene (co) polymer of the present invention is as follows. That is, a sample is dissolved in orthodichlorobenzene (ODCB) to which an antioxidant has been added by heating at 135 ° C. to a concentration of 0.2% by weight, and then diatomaceous earth (Celite 5)
45) and then transferred to a column packed with 0.1 ° C / mi.
Cool to 25 ° C. at a cooling rate of n and deposit the copolymer sample on the Celite surface. Next, while flowing ODCB at a constant flow rate through the column on which the sample is deposited, the temperature of the column is gradually increased to 120 ° C. in steps of 5 ° C. Then, a solution containing an eluted component corresponding to each temperature is collected. Methanol is added to this solution, the sample is precipitated, filtered and dried to obtain an eluted sample at each temperature. The weight fraction and the degree of branching (the number of branches per 1000 carbon atoms) of each sample are measured. The degree of branching is determined by measuring with ¹³ C-NMR.

For each fraction collected from 30 ° C. to 90 ° C. by such a method, the branching degree is corrected as follows. That is, the degree of branching measured against the elution temperature is plotted, and the correlation is approximated to a straight line by the least square method,
Create a calibration curve. The correlation coefficient of this approximation is large enough.
The value obtained from this calibration curve is defined as the degree of branching of each fraction. Note that, for a fraction collected at an elution temperature of 95 ° C. or higher, this correction is not performed because a linear relationship is not always established between the elution temperature and the degree of branching.

Next, the weight fraction w of each fraction
The _i, the amount of change in the degree of branching b _i per the elution temperature 5 ° C. (b _i
Obtaining the relative concentration c _i is divided by -b _i-1), by plotting the relative concentration against the branching degree to obtain a composition distribution curve. This composition distribution curve is divided by a certain width, and the composition distribution parameter Cb is calculated from the following equation.

[0013]

(Equation 1)

Here, c _j and b _j are the relative density and branching degree of the j-th section, respectively. Composition distribution parameter C
b becomes 1.0 when the composition of the sample is uniform, and becomes larger as the composition distribution becomes wider.

Many proposals have been made for a method of expressing the composition distribution of the ethylene / α-olefin copolymer. For example, in Japanese Patent Application Laid-Open No. 60-88016, numerical processing is performed on the assumption that the cumulative weight fraction has a specific distribution (log normal distribution) with respect to the number of branches of each separated sample obtained by solvent separation of the sample. The ratio between the weight average branching degree (Cw) and the number average branching degree (Cn) is determined. The accuracy of this approximation calculation decreases when the number of branches and the cumulative weight fraction of the sample deviate from the lognormal distribution, and when measurement is performed on a commercially available LLDPE, the correlation coefficient R ² is considerably low, and the accuracy of the value is not sufficient. In addition, the method of measuring Cw / Cn and the numerical processing method are the same as those of the present invention.
Although it is different from that of b, if you dare to compare the values, Cw
The value of / Cn is much larger than Cb.

The ethylene (co) polymer of the present invention exhibits good performance as an inflation film aimed at by the present invention by satisfying the above-mentioned parameters (a) to (d), but more preferably. , Below (a) ~
(F) Requirements (a) Density 0.86 to 0.96 g / cm ³ (b) Melt flow rate 0.01 to 100 g / 10 min (c) Molecular weight distribution (Mw / Mn) 1.5 to 5 (D) Composition distribution parameter Cb is 1.08 to 2.00 (e) Substantially a plurality of peaks in an elution temperature-elution amount curve by a continuous heating elution fractionation method (TREF) (f) Orthodichlorobenzene (ODC) at 25 ° C
B) The relationship between the amount of soluble matter X (wt%) and the density d and MFR (melt flow rate) is as follows: a) d-0.008 log MFR ≧ 0.93 X <2.0 b) d-0.008 When log MFR <0.93 X <9.8 × 10 ³ × (0.9300−d + 0.008 log
It is desirable to use an ethylene (co) polymer satisfying (MFR) ² +2.0.

The special ethylene (co) polymer of the present invention is
The ethylene (co) polymer further satisfies the requirements (a) to (c) and the requirements (d) to (f). The (d) composition distribution parameter Cb of the special ethylene (co) polymer is in the range of 1.08 to 2.00, preferably 1.10 to 1.18, and more preferably 1.15 to 1.18.
It is desirably in the range of 17.

Further, (e) a continuous heating elution fractionation method (TRE)
There are substantially a plurality of peaks in the elution temperature-elution amount curve according to F), and it is particularly desirable that the plurality of peaks desirably exist between 85 ° C and 100 ° C. The presence of this peak improves the heat resistance of the product.

The ethylene (co) polymer of the present invention is shown in FIG.
In the elution temperature-elution amount curve obtained by the continuous heating elution fractionation method (TREF) as shown in FIG. 2, substantially a plurality of peaks are a special novel ethylene (co) polymer, as shown in FIG. A metallocene-based catalyst, that is, an ethylene (co) polymer obtained in the presence of at least one catalyst containing a ligand having a cyclopentadienyl skeleton and a transition metal compound of Group IV of the periodic table. It is clearly distinguished from an ethylene (co) polymer having substantially one peak in an elution temperature-elution amount curve obtained by a continuous heating elution fractionation method (TREF).

The method for measuring TREF according to the present invention is as follows. A sample was added to an ODCB containing an antioxidant (eg, butylhydroxytoluene) at a sample concentration of 0.0
It is added so as to have a concentration of 5% by weight and dissolved by heating at 135 ° C.
5 ml of this sample solution is injected into a column filled with glass beads, cooled to 25 ° C. at a cooling rate of 0.1 ° C./min, and the sample is deposited on the surface of the glass beads. Next, the sample is sequentially eluted while the column temperature is raised at a constant rate of 50 ° C./hr while flowing ODCB through the column at a constant flow rate. At this time, the concentration of the sample eluted in the solvent is continuously detected by measuring the absorption of the asymmetric stretching vibration of methylene at a wave number of 2925 cm ^-1 with an infrared detector. From this value, the concentration of the ethylene / α-olefin copolymer in the solution is quantitatively analyzed to determine the relationship between the elution temperature and the elution rate. According to TREF analysis, with a very small amount of sample,
Since the change in the elution rate with respect to the temperature change can be continuously analyzed, relatively fine peaks that cannot be detected by the fractionation method can be detected.

(F) 2 of the ethylene (co) polymer of the present invention
The relationship between the amount X (wt%) of orthodichlorobenzene (ODCB) soluble matter at 5 ° C., the density d and the MFR (melt flow rate) is such that the values of d and MFR are d−0.0
When 08 log MFR ≧ 0.93 is satisfied, X is less than 2% by weight, preferably less than 1% by weight, and d-0.008 log
When MFR <0.93, X <9.8 × 10 ³ × (0.9300−d + 0.008 log
MFR) ² +2.0 Preferably, X <7.4 × 10 ³ × (0.9300−d + 0.008 log
MFR) ² +1.0 More preferably, X <5.6 × 10 ³ × (0.9300−d + 0.008 log
It is desirable that the relationship of (MFR) ² +0.5 be satisfied.

The amount of the ODCB-soluble component at 25 ° C. is measured by the following method. 0.5 g of sample is 20 m
Heat at 135 ° C. for 2 hours with 1 ODCB to completely dissolve the sample and cool to 25 ° C. Put this solution at 25 ° C
After overnight standing, filter through a Teflon filter and collect the filtrate. The absorption peak area near the wave number 2925 cm ^-1 of the asymmetric stretching vibration of methylene in the filtrate is determined, and the sample concentration is calculated from a previously prepared calibration curve. From this value, 2
The amount of ODCB-soluble matter at 5 ° C. is determined.

The ODCB-soluble matter at 25 ° C. is a high branching degree component and a low molecular weight component contained in the ethylene / α-olefin copolymer, and causes hygiene problems and blocking of the inner surface of the molded article. It is desirable that this content be small. The amount of ODCB solubles is affected by the comonomer content and molecular weight. Therefore, the fact that the density and the amounts of MFR and ODCB-soluble component, which are indicators, satisfy the above relationship indicates that the uneven distribution of α-olefin contained in the whole copolymer is small.

The ethylene (co) polymer of the present invention is not particularly limited to a catalyst, a production method or the like as long as it satisfies the above-mentioned specific parameters, but is preferably an organic cyclic compound having at least a conjugated double bond. And an ethylene (co) polymer obtained by (co) polymerizing ethylene or ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of a catalyst containing a transition metal compound of Group IV of the periodic table. desirable.

The production of the ethylene (co) polymer of the present invention
In particular, it is desirable to carry out polymerization with a catalyst obtained by mixing the following compounds a1 to a4. a1: General formula Me ¹ R ¹ _p R ² _q (OR ³ ) _r X ¹
A compound represented by _4-pqr (wherein Me ¹ represents zirconium, titanium or hafnium, R ¹ and R ³ are each a hydrocarbon group having 1 to 24 carbon atoms, and R ² is 2.4-pentanedionato A ligand or a derivative thereof, a benzoylmethanato ligand, a benzoylacetonate ligand or a derivative thereof, X ¹ represents a halogen atom, and p, q and r represent 0 ≦ p ≦ 4 and 0 ≦ q ≦ 4, respectively. , 0 ≦ r ≦ 4, 0 ≦ p
A2: a compound represented by the general formula Me ² R ⁴ _m (OR ⁵ ) _n X ² _zmn (where Me ² is an element of Groups I to III of the periodic table, R ⁴ and R ⁵ are each a hydrocarbon group having 1 to 24 carbon atoms, and X ² is a halogen atom or a hydrogen atom (however, X
^{When 2} is a hydrogen atom, Me ² is limited to a group III element in the periodic table), z is a valence of Me ² , and m and n are respectively 0 ≦ m ≦ z, 0 ≦ n ≦ a3: an organic cyclic compound having a conjugated double bond a4: a modified organic aluminum oxy compound and / or a boron compound containing an Al-O-Al bond

The details will be described below. The above-mentioned catalyst component a1
In the formula of the compound represented by the general formula Me ¹ R ¹ _p R ² _q (OR ³ ) _r X ¹⁴ _-pqr , Me ¹ represents zirconium, titanium or hafnium, and the types of these transition metals are limited. It is not limited to this, and a plurality of them can be used, but it is particularly preferable that the copolymer contains zirconium having excellent weather resistance. R ¹ and R ³ each have 1 to 2 carbon atoms
It is a hydrocarbon group of 4, preferably 1 to 12, more preferably 1 to 8 carbon atoms. Specifically, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group and butyl group; alkenyl groups such as vinyl group and allyl group; phenyl group, tolyl group, xylyl group, mesityl group, indenyl group and naphthyl group And an aralkyl group such as a benzyl group, a trityl group, a phenethyl group, a styryl group, a benzhydryl group, a phenylbutyl group, and a neofuyl group. These may have branches. R
² represents a 2.4-pentanedionato ligand or a derivative thereof, a benzoylmethanato ligand, a benzoylacetonato ligand or a derivative thereof. X ¹ represents a halogen atom such as fluorine, iodine, chlorine and bromine. p and q are respectively 0 ≦ p ≦ 4, 0 ≦ q ≦ 4, 0 ≦ r ≦ 4,
It is an integer satisfying the range of 0 ≦ p + q + r ≦ 4.

Examples of the compound represented by the general formula of the above-mentioned catalyst component a1 include tetramethylzirconium, tetraethylzirconium, tetrabenzylzirconium, tetrapropoxyzirconium, tripropoxymonochlorodichloroconium, tetrabutoxyzirconium, tetrabutoxytitanium, tetrabutoxyhafnium In particular, Zr (OR) ₄ compounds such as tetrapropoxy zirconium and tetrabutoxy zirconium are preferred, and two or more of these may be used in combination.
Specific examples of the 2,4-pentanedionato coordination or derivative thereof, benzoylmethanato ligand, benzoylacetonato ligand or derivative thereof include tetra (2,4-pentanedionato) zirconium. , Tri (2,4-pentanedionato) chloride zirconium, di (2,4-pentanedionato) dichloride zirconium, (2,4-pentanedionato) trichloride zirconium, di (2,4-pentanedionato) Diethoxide zirconium, di (2,4-pentanedionato) di-n-propoxide zirconium, di (2,4
-Pentanedionato) di-n-butoxide zirconium, di (2,4-pentanedionato) dibenzylzirconium, di (2,4-pentanedionato) dineofylzirconium, tetra (dibenzoylmethanato) zirconium , Di (dibenzoylmethanato) diethoxide zirconium, di (dibenzoylmethanato) di-n-propoxide zirconium, di (dibenzoylmethanato)
Di-n-butoxide zirconium, di (benzoylacetonato) diethoxide zirconium, di (benzoylacetonato) di-n-propoxide zirconium,
And di (benzoylacetonato) di-n-butoxide zirconium.

The general formula Me ² R of the catalyst component a2
^In the formula of the compound represented by ⁴ _m (OR ⁵ ) _n X ² _zmn
e ² represents the periodic table I~III group element is lithium, sodium, potassium, magnesium, calcium, zinc, boron, aluminum. R ⁴ and R ⁵
Is a hydrocarbon group having 1 to 24 carbon atoms, preferably 1 to 12 carbon atoms, and more preferably 1 to 8 carbon atoms. Specific examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, and butyl group. Alkenyl groups such as vinyl group and allyl group; aryl groups such as phenyl group, tolyl group, xylyl group, mesityl group, indenyl group and naphthyl group; benzyl group, trityl group, phenethyl group, styryl group, benzhydryl group, phenyl An aralkyl group such as a butyl group and a neofuyl group is exemplified. These may have branches. X ² represents a halogen atom or a hydrogen atom such as fluorine, iodine, chlorine and bromine. However, when X ² is a hydrogen atom, Me ² is limited to a group III element of the periodic table exemplified by boron, aluminum and the like. Z represents the valence of Me ² , and m and n are respectively 0 ≦ m ≦ z, 0 ≦ n ≦ z
And satisfies 0 ≦ m + n ≦ z.

Examples of the compound represented by the general formula of the catalyst component a2 include organic lithium compounds such as methyllithium and ethyllithium; organic magnesium compounds such as dimethylmagnesium, diethylmagnesium, methylmagnesium chloride and ethylmagnesium chloride; Organic zinc compounds such as zinc and diethyl zinc; organic boron compounds such as trimethyl boron and triethyl boron; trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, trihexyl aluminum, tridecyl aluminum, diethyl aluminum chloride, ethyl aluminum dichloride, ethyl aluminum sesqui Organic compounds such as chloride, diethylaluminum ethoxide and diethylaluminum hydride Derivatives such as iodonium compounds.

The organic cyclic compound having a conjugated double bond of the catalyst component a3 has one or more rings having two or more, preferably 2 to 4, more preferably 2 to 3, conjugated double bonds. A cyclic hydrocarbon compound having 2 or more and having a total carbon number of 4 to 24, preferably 4 to 12; wherein the cyclic hydrocarbon compound partially has 1 to 6 hydrocarbon residues (typically, carbon A cyclic hydrocarbon compound substituted with an alkyl group or an aralkyl group of the formulas 1 to 12; two or more, preferably 2 to 4, more preferably 2 to 2, conjugated double bonds.
One or more rings having three rings and a total carbon number of 4
An organosilicon compound having a cyclic hydrocarbon group of from 24 to 24, preferably 4 to 12; said cyclic hydrocarbon group being partially substituted by 1 to 6 hydrocarbon residues or an alkali metal salt (sodium or lithium salt) Organosilicon compounds. Particularly preferably, those having a cyclopentadiene structure in any of the molecules are desirable.

Examples of the preferred compounds include cyclopentadiene, indene, azulene and their alkyl, aryl, aralkyl, alkoxy or aryloxy derivatives. Further, a compound obtained by bonding (crosslinking) these compounds via an alkylene group (the number of carbon atoms of which is usually 2 to 8, preferably 2 to 3) is also preferably used.

The organosilicon compound having a cyclic hydrocarbon group can be represented by the following general formula. A _L SiR _4-L wherein A represents the above-mentioned cyclic hydrogen group exemplified by a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, and a substituted indenyl group, and R represents a methyl group, an ethyl group, a propyl group. Alkyl groups such as methoxy, ethoxy, propoxy and butoxy groups; aryl groups such as phenyl groups; aryloxy groups such as phenoxy groups; aralkyl groups such as benzyl groups. And represents a hydrocarbon residue having 1 to 24 carbon atoms, preferably 1 to 12 carbon atoms or hydrogen, and L represents 1
≦ L ≦ 4, preferably 1 ≦ L ≦ 3.

Specific examples of the organic cyclic hydrocarbon compound of the component a3 include cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, 1,3-dimethylcyclopentadiene, indene, 4-methyl-1-indene, 4,7- C5-C24 cyclopolyene or substituted cyclopolyene such as dimethylindene, cycloheptatriene, methylcycloheptatriene, cyclooctatetraene, azulene, fluorene, methylfluorene, monocyclopentadienylsilane, biscyclopentadiene Examples include enylsilane, triscyclopentadienylsilane, monoindenylsilane, bisindenylsilane, and trisindenylsilane.

The modified organoaluminum oxy compound containing an Al--O--Al bond of the catalyst component a4 is obtained by reacting an alkylaluminum compound with water to obtain a modified organoaluminum oxy compound usually called aluminoxane. The molecule usually contains 1 to 100, preferably 1 to 50 Al-O-Al bonds. The modified organic aluminum oxy compound may be linear or cyclic.

The reaction between the organoaluminum and water is usually carried out in an inert hydrocarbon. As the inert hydrocarbon,
Aliphatic, alicyclic and aromatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, benzene, toluene and xylene are preferred. The reaction ratio between water and the organoaluminum compound (water / Al molar ratio) is usually 0.25 / 1 to 1.2.
/ 1, preferably 0.5 / 1 to 1/1.

Examples of the boron compound include triethylaluminum tetra (pentafluorophenyl) borate (triethylammonium tetra (pentafluorophenyl)
Borate, dimethylanilinium tetra (pentafluorophenyl) borate (dimethylanilinium tetra (pentafluorophenyl) borate, butylammonium tetra (pentafluorophenyl) borate, N, N-
Dimethylanilinium tetra (pentafluorophenyl) borate, N, N-dimethylaniliniumtetra (3,5-difluorophenyl) borate and the like can be mentioned.

The above catalyst is used by mixing and contacting a1 to a4.
It may be used, but preferably an inorganic carrier and / or granules
It can be used by being supported on the polymer carrier (a5).
desirable. The inorganic carrier and / or the particulate polymer
The body (a5) includes carbonaceous materials, metals, metal oxides, and metal salts.
, Metal carbonates or their mixtures or thermoplastics
Resins, thermosetting resins and the like. To the inorganic carrier
Suitable metals that can be used include iron, aluminum
And nickel. Specifically, Si
O_Two, Al_TwoO_Three, MgO, ZrO_Two, TiO_Two, B_Two
O_Three, CaO, ZnO, BaO, ThO_TwoEtc or this
Mixtures thereof, such as SiO 2 _Two-Al_TwoO_Three, SiO
_Two-V_TwoO_Five, SiO_Two-TiO_Two, SiO_Two-V_TwoO
_Five, SiO_Two-MgO, SiO_Two−Cr_TwoO_ThreeEtc.
Can be Among them, SiO_TwoAnd Al_TwoO_ThreeFrom
At least one component selected from the group consisting of
Are preferred. In addition, as organic compounds, heat
Both plastic resin and thermosetting resin can be used.
Are particulate polyolefins, polyesters, polyamides
, Polyvinyl chloride, polymethyl (meth) acrylate,
Polystyrene, polynorbornene, various natural polymers and
And mixtures thereof.

The above-mentioned inorganic carrier and / or particulate polymer carrier can be used as they are, but preferably, as a pretreatment, these carriers are treated with an organic aluminum compound or a modified organic aluminum oxy compound containing an Al—O—Al bond. Can be used as the component a5 after the contact treatment.

Since the ethylene (co) polymer of the present invention has a relatively narrow molecular weight distribution and composition distribution, it is a polymer having high mechanical strength, excellent heat sealing properties, excellent antiblocking properties, and excellent heat resistance. When the catalyst component at the time of polymerization is substantially free of halogens such as chlorine, the resulting polymer does not contain these halogens, and therefore has excellent chemical stability and hygiene, especially in food packaging materials, medical Useful for packaging materials and the like.

The process for producing an ethylene (co) polymer of the present invention is carried out by a gas phase polymerization method, a slurry polymerization method, a solution polymerization method or the like in the presence of the above-mentioned catalyst and substantially without a solvent. With oxygen and water turned off, butane, pentane,
In the presence or absence of an inert hydrocarbon solvent exemplified by aliphatic hydrocarbons such as hexane and heptane; aromatic hydrocarbons such as benzene, toluene and xylene; and cycloaliphatic hydrocarbons such as cyclohexane and methylcyclohexane. Manufactured in. The polymerization conditions are not particularly limited, but the polymerization temperature is usually 15 to 350 ° C., preferably 20 to 200 ° C., more preferably 50 to 110 ° C., and the polymerization pressure is usually normal pressure to 70 kg / cm ^{2 in} the case of the low and medium pressure method. G, preferably normal pressure to 20 kg / cm ² G, and usually 15
00 kg / cm ² G or less is desirable. The polymerization time is usually from 3 minutes to 10 hours, preferably from 5 minutes to 5 hours in the case of the low and medium pressure method. In the case of the high-pressure method, it is usually 1 minute to 30 minutes, preferably about 2 minutes to 20 minutes. In addition, the polymerization is not particularly limited to a single-stage polymerization method, as well as a multi-stage polymerization method of two or more stages in which polymerization conditions such as hydrogen concentration, monomer concentration, polymerization pressure, polymerization temperature, and catalyst are different from each other.

The film of the present invention is an inflation film comprising the above-mentioned novel ethylene (co) polymer, wherein the concentric lumps formed of an aggregate of crystal lamella on the surface of the film have a crystal grain size of 0.5 to 8 μm, More preferably 1 to
7 μm, more preferably in the range of 2 to 5 μm. Within this range, a film having a high strength, a film having a tear strength in the longitudinal (MD) direction of 20 kgf / cm or more and a tear strength in the transverse (TD) direction of 60 kgf / cm or more can be formed in a well-balanced strength, and can be formed in half. It is possible to obtain a transparent film having good shielding properties. When the crystal grain size of the concentric ingot is less than 0.5 μm, the film strength (longitudinal direction is weakened and horizontal direction is strong) is reduced, and the strength balance is also deteriorated. On the other hand, it is difficult to grow concentric ingots having a crystal size of 8 μm or more by inflation molding. In particular, the production speed is extremely reduced, which is not practical.

The crystal grain size of the concentric mass of the present invention is formed by growing crystal lamella aggregates on the film surface into fibrils by inflation molding,
The crystal grain size L of the concentric block is determined by a scanning electron microscope JEOL-T.
330A (manufactured by JEOL Ltd.). This scanning microscope collides an electron beam with the sample surface and generates
It utilizes secondary electrons, and forms an image of the sample surface by detecting diffracted electrons.

FIG. 3 (Photo 1) and FIG. 4 (Photo 2)
The specific ethylene-1-hexene copolymer of the present invention having a density of 0912 g / cm ^{3 by} the gas phase method was extruded from Placo using a screw extruder with a screw diameter of 55 mmφ, a die with a diameter of 70 mmφ, and a molding temperature of 1.
An electron micrograph of the blown film molded under the molding conditions of 80 ° C., a film width of 300 mm, and a blow ratio of 2.7 using the above scanning electron microscope (Photo 1 is a magnification of 35).
2,000 times, Photo 2 is measured at 5,000 times magnification), the aggregate of crystal lamella on the film surface grows in the form of fibrils, concentric crystal masses are formed, and the particle size L is within the scope of the present invention. It turns out that it is 0.5-8 micrometers. On the other hand, FIG. 5 (Photo 3) (magnification 3500 times) and FIG. 6 (Photo 4)
(Magnification: 5000 times) shows the result of molding a gas phase method ethylene-1-hexene copolymer (LLDPE) with a density of 0917 g / cm ³ using a commercially available Ziegler catalyst under the same conditions as in the present invention. And a commercially available gas phase LLD
It can be seen that PE has a particle size L of 100 to 300 nm, which is smaller than that of the present invention.

As described above, the blown film of the present invention has a concentric crystal grain size, a large crystal mass, and a high film strength as compared with the conventional LLDPE film. In addition, the crystallites inside the film also grow as fibrils of crystal lamella aggregates, and the particle diameter of the concentric mass increases at the same time, so that the internal haze value of the film can be increased. With such a large particle size and the crystal morphology of the concentric mass, the density of tie molecules (tie molecules) connecting the lamellas is increased, and the anisotropy is reduced. Is considered to be better. Further, the surface of the film is uneven, and the external haze of the film is 20% or more, which makes it possible to provide a desired film having good shielding properties.

In the blown film of the present invention,
As long as the object of the present invention is not impaired, an antistatic agent, an antioxidant, a lubricant, an antiblocking agent, an antifogging agent, if necessary,
Known additives such as organic or inorganic pigments, UV inhibitors and dispersants can be added.

The blown film of the present invention is generally selected from the range of 10 to 200 μm, preferably 30 to 100 μm in view of its ease of handling.

The inflation molding of the present invention generally means extrusion at a temperature of 120 to 250 ° C. through a circular die using an extruder, rapid cooling by contact with air blown from an air-cooled air ring, solidification, and taking out with a pinch roll. After that, it is performed by winding it around a frame.
The molding conditions include a film take-up speed of 20 to 120.
m / min, and the blow-up ratio is selected in the range of 2.0 to 4.0, preferably 2.2 to 3.0. If the blow-up ratio is less than 2.0, the direction perpendicular to the resin flow (T
D direction), a sufficient orientation was not obtained, and the resin flow direction (M
In the direction (D), the aggregate of crystal lamellas becomes fibrils, and the growth rapidly increases. As a result, concentric lumps of crystals cannot be obtained, and it is difficult to make the grain diameter of the lumps in the range of 0.5 to 8 μm. In particular, it becomes an anisotropic crystal lump which is long in the flow direction (MD direction) of the resin having a particle diameter of 8 μm or more, and cannot exhibit excellent strength and a balance between longitudinal and lateral strengths. On the other hand, if the blow-up ratio exceeds 4.0, the vibration of the bubbles increases during molding, and the molding stability is lost.

The frost line height during inflation molding is 100 mm to 700 mm, preferably 30 mm.
The range is from 0 to 600 mm. The frost line height is
If it is less than 100 mm, a large amount of cooling air is required, so that the vibration of the bubble during molding increases, and the molding stability is lost. Furthermore, rapid cooling makes it difficult to grow the crystal diameter of the concentric mass to 0.5 μm or more. Further, the external haze of the film becomes 20 or less, and the light-shielding property is reduced. Frost line height is 70
When the diameter exceeds 0 mm, the bubbles are gradually cooled by a cooling air having a weak air flow, so that the particle size of the crystals of the concentric mass is 0.5 to 8 μm.
Within the range. In particular, the particle size becomes 8 μm or more, the surface of the film is roughened, and causes adhesion of dust and dust.

[0049]

The ethylene (co) polymer of the present invention was produced by the following method. (Preparation of solid catalyst) Purified toluene was added to a catalyst preparation device (No. 1) with an electromagnetic induction stirrer under nitrogen, and then dipropoxydichlorozirconium (Zr (OPr) ₂ C
l ₂ ) 28 g and methylcyclopentadiene 48 g were added, and while maintaining the system at 0 ° C., 45 g of tridecylaluminum was added dropwise. After completion of the dropwise addition, the reaction system was maintained at 50 ° C. and stirred for 16 hours. This solution is designated as solution A. Next, purified toluene was added to another catalyst preparation device with a stirrer (No. 2) under nitrogen, and the above solution A and then a 6.4 mol solution of methylaluminoxane in toluene were added and reacted.
This is designated as solution B. Next, purified toluene was added to a preparation device with a stirrer (No. 1) under nitrogen, and then silica (Fuji Devison, grade # 952, surface area 300 m ² / g) 14 previously calcined at 400 ° C. for a predetermined time.
After adding 00 g, the entire amount of the B solution was added, and the mixture was stirred at room temperature. Then, the solvent was removed by nitrogen blowing to obtain a solid catalyst powder having good fluidity. This is designated as catalyst C.

(Polymerization of Sample) Using a continuous fluidized bed gas phase polymerization apparatus, a polymerization temperature of 70 ° C. and a total pressure of 20 kgf / cm ² were used.
G copolymerized ethylene with 1-butene or 1-hexene. The polymerization was carried out by continuously supplying the catalyst C, and the polymerization was carried out while continuously supplying each gas in order to keep the gas composition in the system constant.

(Resin component) (A1) Ethylene / 1-butene copolymer Density = 0.910 g / cm ³ , MFR = 0.5 g / 10
Molecular weight distribution (Mw / Mn) = 2.7 Composition distribution parameter (Cb) = 1.24 d−0.008 log MFR = 0.912 ODCB soluble matter (%) = 3.0 <9.8 × 10 ³ × (0.9300-d +
0.008 log MFR) ² +2.0 TREF peak temperature = 70.3 ° C, 75.1 ° C, 95.
1 ° C. (A2) Ethylene / 1-hexene copolymer Density = 0.912 g / cm ³ , MFR = 0.7 g / 10
Molecular weight distribution (Mw / Mn) = 2.6 Composition distribution parameter (Cb) = 1.23 d−0.008 log MFR = 0.913 ODCB soluble matter (%) = 2.8 <9.8 × 10 ³ × (0.9300-d +
0.008 log MFR) ² +2.0 TREF peak temperature = 69.7 ° C., 92.1 ° C. (B) Commercially available ethylene-1-hexene copolymer (gas phase method) Density 0.917 g / cm ³ , MFR = 0.8 g / 10 minutes

Using the above resin, a film was formed by the air-cooled inflation molding method under the following conditions. <Molding conditions> Placo extruder: screw diameter 55 mm
φ, die: 70 mmφ, molding temperature: 180 ° C., film width: 300 mm, blow ratio: 2.7, thickness: 30 μm

The crystal grain size, tear strength,
Table 1 shows the results of measuring external haze and the like. (Test method) Measurement of crystal grain size: Scanning electron microscope JEOL-T330A
(JEOL Ltd.) Tear strength: JIS P8116 External haze: Measured according to ASTM D1003. (External haze is equivalent to total haze minus internal haze)

[0054]

[Table 1]

[0055]

The blown film of the present invention is
By using a specific novel ethylene (co) polymer and controlling the aggregate of crystal lamella on the film surface, it has excellent strength and excellent balance of strength in the vertical and horizontal directions. An excellent film and a method for producing the film can be provided.

[Brief description of the drawings]

FIG. 1 is a TREF curve of the ethylene copolymer of the present invention.

[FIG. 2] TR of ethylene copolymer with metallocene catalyst
EF curve.

FIG. 3 is an electron micrograph (magnification: 350) of a blown film made of the ethylene-1-hexene copolymer of the present invention.
0 times).

FIG. 4 is an electron micrograph (magnification: 500) of a blown film made of the ethylene-1-hexene copolymer of the present invention.
0 times).

FIG. 5 is an electron micrograph (3500 times magnification) of a blown film made of an ethylene-1-hexene copolymer using a commercially available Ziegler catalyst.

FIG. 6 is an electron micrograph (5,000-fold magnification) of a blown film made of an ethylene-1-hexene copolymer using a commercially available Ziegler catalyst.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Takashi Komazawa, 2-3-2 Nightlight, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Japan Polyolefin Co., Ltd. Kawasaki Research Laboratory (72) Inventor Zhu Yi Exhibition 2 Nightlight, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture -3-2 Kawasaki Laboratory, Japan Polyolefin Co., Ltd. (72) Inventor Yoshihiro Mogi 2-3-2 Night Light, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Kawasaki Laboratory, Japan Polyolefin Co., Ltd.

Claims (5)

[Claims] An inflation film comprising an ethylene (co) polymer satisfying the following requirements (a) to (d), wherein the concentric lumps formed of an aggregate of crystal lamella on the film surface have a crystal grain size of 0: A blown film having a tear strength of at least 20 kgf / cm in the longitudinal (MD) direction, at least 60 kgf / cm in the transverse (TD) direction, and an external haze of at least 20%. . (B) Density 0.86 to 0.97 g / cm ³ (b) Melt flow rate 0.01 to 100 g / 10 min (c) Molecular weight distribution (Mw / Mn) 1.5 to 5.0 (d) Composition distribution parameter Cb is 2.00 or less 2. An inflation film comprising an ethylene (co) polymer satisfying the following requirements (a) to (f), wherein a crystal grain diameter of a concentric mass formed of an aggregate of crystal lamella on the film surface is 0: A blown film having a tear strength of at least 20 kgf / cm in the longitudinal (MD) direction, at least 60 kgf / cm in the transverse (TD) direction, and an external haze of at least 20%. . (B) Density 0.86 to 0.97 g / cm ³ (b) Melt flow rate 0.01 to 100 g / 10 min (c) Molecular weight distribution (Mw / Mn) 1.5 to 5.0 (d) The composition distribution parameter Cb is 1.08 to 2.00 (e) Substantially a plurality of peaks in an elution temperature-elution amount curve by a continuous heating elution fractionation method (TREF) (f) orthodichlorobenzene at 25 ° C (ODC
B) Soluble content X (wt%), density d and MFR (melt flow rate) satisfy the following relationship: a) d-0.008 log MFR ≧ 0.93 X <2.0 b) d −0.008 log When MFR <0.93 X <9.8 × 10 ³ × (0.9300−d + 0.008 log
MFR) ² +2.0 3. The ethylene (co) polymer is obtained by converting ethylene or ethylene and an α-olefin in the presence of a catalyst containing at least an organic cyclic compound having a conjugated double bond and a transition metal compound of Group IV of the periodic table. The blown film according to claim 1, which is an ethylene (co) polymer obtained by (co) polymerization. 4. A take-off speed of 20 to 120 using an ethylene (co) polymer satisfying the following requirements (a) to (d):
m / min, blow-up ratio 2-4, frost line 100
A method for producing an inflation film, wherein the inflation film is formed at a thickness of 700 mm. (B) Density 0.86 to 0.97 g / cm ³ (b) Melt flow rate 0.01 to 100 g / 10 min (c) Molecular weight distribution (Mw / Mn) 1.5 to 5.0 (d) Composition distribution parameter Cb is 2.00 or less 5. An ethylene (co) polymer comprising ethylene or ethylene and an α-olefin in the presence of a catalyst containing at least an organic cyclic compound having at least a conjugated double bond and a transition metal compound of Group IV of the periodic table. The method for producing an inflation film according to claim 4, which is an ethylene (co) polymer obtained by (co) polymerization.