JP2002265712A - Easily tearable film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare an easily tearable film having good tearability and rigidity. SOLUTION: This easily tearable film comprises 20-100 wt.% propylene based resin (X) having a die swell ratio of >=1.8 and 80-0 wt.% olefin based resin (Y) which is different from the propylene based resin (X).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an easily tearable film.

[0002]

2. Description of the Related Art Polypropylene films are excellent in optical properties such as transparency and glossiness, mechanical properties such as tensile strength, rigidity and impact strength, heat resistance, etc., and are inexpensive. , Used in textile packaging and other wide-ranging applications.

[0003] However, these properties are not fully satisfied depending on the use. The unstretched polypropylene film is excellent in rigidity, but has a problem that the tear strength is too high, the film is not easily torn, and the openability in a bag is poor.

In order to improve this, for example, Japanese Patent Publication 6-6
Japanese Patent No. 8031 discloses a biaxially stretched film mainly composed of a composition comprising a propylene resin and a petroleum resin or a terpene resin. Have been proposed. However, in the method of preparing a film having molecular orientation by performing these stretchings, an equipment for performing the stretching is required, and equipment costs, operation costs, and the like are required, and film production costs are increased.

[0005]

Under such circumstances, an object of the present invention is to provide an easily tearable film having good tearability and rigidity.

[0006]

According to the present invention, there is provided a propylene resin (X) having a die swell ratio of 1.8 or more.
This problem is solved by an easily tearable film comprising a resin composition containing 80 to 0% by weight of an olefin-based resin (Y) different from the propylene-based resin (X). Hereinafter, the present invention will be described in more detail.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The easily tearable film of the present invention comprises a propylene resin (X) 2 having a die swell ratio of 1.8 or more.
0 to 100% by weight, and the propylene-based resin (X)
And 80 to 0% by weight of an olefin resin (Y) different from the above. However, the total of (X) and (Y) is 100% by weight.
It is. Further, the case where the (Y) is 0% by weight is a case where the (Y) is not contained.

The die swell ratio of the propylene-based resin (X) is at least 1.8, preferably 2 to 4, more preferably 2 to 3. If the die swell ratio of the propylene-based resin (a) is too small, the tearability is undesirably reduced. The die swell ratio referred to here is JIS K7210.
Melt flow rate (MFR) according to the method of Condition 14 of
The diameter of the cross section of the extrudate at the time of measurement is measured, and a value determined from the following equation is adopted. Die swell ratio = diameter of cross section of extrudate / diameter of orifice However, the cross section of extrudate means a cross section perpendicular to the extrusion direction of the extrudate, and when the cross section is not a perfect circle, the maximum diameter of the cross section The average of the value and the minimum value is defined as the diameter of the cross section of the extrudate.

The content of the propylene resin (X) is 20
-100% by weight, preferably 45-100% by weight. When the content of the propylene-based resin (X) is within the above range, excellent tearability is preferred, and this is preferred.

The propylene resin referred to herein is a resin having an isotactic polypropylene crystal structure.
A thermoplastic propylene polymer resin containing 50% by weight or more of a repeating unit derived from propylene is preferable, and a propylene homopolymer, propylene and an α-olefin having 2 to 10 carbon atoms (excluding propylene)
Or a copolymer of propylene and at least one other monomer. Examples of the α-olefin include ethylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, and 1-decene. As other monomers, conjugated dienes (for example, butadiene and isoprene) can be exemplified.

When the propylene-based resin (X) of the present invention is the following propylene polymer (T), the resulting easily tearable film is more excellent in rigidity and is preferred. Propylene polymer (T): a step of producing a crystalline propylene polymer part (A) having an intrinsic viscosity of 5 dl / g or more and a step of producing a crystalline propylene polymer part (B) having an intrinsic viscosity of less than 3 dl / g Wherein the content of the crystalline propylene polymer portion (A) in the propylene polymer (T) is 0.05% by weight or more and less than 35% by weight. A propylene polymer (T) having an intrinsic viscosity of less than 3 dl / g and a molecular weight distribution of less than 10; When the propylene-based resin (X) of the present invention is the above-mentioned propylene polymer (T), the resulting easily tearable film is excellent in transparency and heat resistance, and is further excellent in rigidity in the vertical and horizontal balance.

As a specific method for producing such a propylene polymer (T), for example, the same polymerization as that in which (A) is polymerized in the first step and then (A) is polymerized in the second step A batch polymerization method in which (B) is polymerized in a tank, or two or more polymerization tanks are arranged in series, and as a first step, the product after polymerization of (A) is transferred to the next polymerization tank, and the polymerization tank is As the second step, a continuous polymerization method for polymerizing (B) and the like can be mentioned.
In the case of a continuous polymerization method, the number of polymerization tanks in each of the first and second stages may be one or two or more.

The intrinsic viscosity of the crystalline propylene polymer portion (A) of the propylene polymer (T) is at least 5 dl / g, more preferably at least 6 dl / g. When the intrinsic viscosity of (A) is in the above range, excellent heat resistance and easy tearability are obtained.
The intrinsic viscosity of (A) is preferably as high as possible, and there is no particular upper limit, but it is usually less than 15 dl / g. The intrinsic viscosity of (A) is more preferably 6 to 13 dl / g, particularly preferably 7 to 11 dl / g.

The content of the crystalline propylene polymer portion (A) in the propylene polymer (T) is preferably at least 0.05% by weight, more preferably at least 0.1% by weight. The amount of the crystalline propylene polymer portion (A) is usually preferably less than 35% by weight, more preferably 25% by weight or less. That is, the content of the crystalline propylene polymer (A) in the propylene polymer (T) is preferably 0.05% by weight or more and less than 35% by weight, more preferably 0.1% to 25% by weight. Preferably it is 0.3 to 18% by weight. When the amount of the crystalline propylene polymer portion (A) is within the above range, excellent heat resistance and easy tearability are obtained. The ratio of (A) may be adjusted to a predetermined amount by polymerization conditions or the like during polymerization, or the amount of (A) may be adjusted by adding a component corresponding to (B) in a melting step or a kneading step. .

The intrinsic viscosity of the crystalline propylene polymer portion (B) is less than 3 dl / g, preferably 2 dl / g.
g or less. Within this range, the fluidity and processability are excellent and are preferred. The intrinsic viscosity of (B) is preferably as low as possible, and there is no particular lower limit, but it is usually at least 0.5 dl / g. The intrinsic viscosity of (B) is more preferably 0.8.
２2 dl / g, and more preferably 1 to 1.8 dl.
/ G.

The intrinsic viscosity of the crystalline propylene polymer portion (B) can be set within the above range by appropriately setting the production conditions of (B). The intrinsic viscosity of the crystalline propylene polymer portion (B) can be determined by the following formula (A).
And (B), the intrinsic viscosity [η] _{T of} the finally obtained propylene polymer (T) and the intrinsic viscosity [η] _{A of} (A) and (A) And (B) the intrinsic viscosity of (B) is determined from the content (% by weight) in (T) by the following equation (1). _{[Η] B = ([η} ] T × 100- [η] A × W A) ÷ W B [ Equation 1] [η] _T: the intrinsic viscosity of propylene polymer (T) (dl /
g) [η] _A: intrinsic viscosity (dl / g) W _A crystalline propylene polymer portion (A): The content of the crystalline propylene polymer portion (A) (wt%) W _B: crystalline propylene heavy Content of coalesced part (B) (% by weight)

The propylene polymer (T) includes the intrinsic viscosity [η] of the crystalline propylene polymer portion (A).
More preferably, _A (dl / g) and the content W _A (% by weight) satisfy the following mathematical formula 2. When _{W A ≧ 400 × EXP (-0.6} × [η] A) [ Equation 2] W _A is within the range of Equation 2 above, heat resistance, more excellent is easy tearable in improvement preferred.

The intrinsic viscosity of the entire propylene polymer (T) is less than 3 dl / g. Within this range, the fluidity and processability are excellent and are preferred. The intrinsic viscosity of (T) is preferably as low as possible, and there is no particular lower limit.
/ G or more. The intrinsic viscosity of (T) is more preferably from 1.0 dl / g to less than 3.0 dl / g, and further preferably from 1.2 dl / g to less than 2.8 dl / g.

The molecular weight distribution of the entire propylene polymer (T) is less than 10, preferably 4 to 8. When the molecular weight distribution of the entire propylene polymer (T) is within the above range, the processability of the film is excellent. The molecular weight distribution referred to herein is defined by G.
P. C. The ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by (gel permeation chromatography) is adopted.

The crystalline propylene polymer portion (A) and the crystalline propylene polymer portion (B) are each a crystalline propylene polymer portion having a polypropylene crystal structure, and may be a homopolymer of propylene or propylene. And a copolymer with a comonomer such as ethylene and / or an α-olefin in such an amount that crystallinity is not lost. Examples of the α-olefin include 1-butene, 4-methyl-1-pentene, 1-octene, 1-hexene and the like. The amount that does not lose crystallinity differs depending on the type of comonomer. For example, in the case of ethylene, the amount of ethylene units in the copolymer is usually 10% by weight or less, and in the case of other α-olefins such as 1-butene. The amount of α-olefin units in the copolymer is usually 30% by weight or less. (A) and (B) may have the same composition or different compositions. (A) and (B) may be combined in a block manner. Furthermore, (A) and (B)
May be co-existed with those other than (A) and (B).

The crystalline propylene polymer (B) may be a polymer in which an amorphous ethylene / α-olefin copolymer is dispersed in a crystalline propylene polymer (T). Examples can be given.

The propylene polymer (T) is produced using various known catalysts. As such a catalyst, a multicomponent catalyst obtained using a solid catalyst component containing a titanium atom, a magnesium atom and a halogen atom is used. A site catalyst or a single-site catalyst obtained by using a metallocene complex or the like can be used. The propylene polymer (T) is preferably produced using a multi-site catalyst obtained using a solid catalyst component containing a titanium atom, a magnesium atom and a halogen atom, and more preferably disclosed in JP-A-11-228629. It is manufactured by the method described.

The olefin resin (Y) constituting the easily tearable film of the present invention is an olefin resin different from the propylene resin (X) contained therein. The olefin-based resin referred to herein is a thermoplastic resin obtained by homopolymerizing an olefin or a thermoplastic resin obtained by copolymerizing a different olefin or copolymerizing an olefin and another monomer. Ethylene as the olefin,
Propylene, 1-butene, 4-methyl-1-pentene,
Examples thereof include 1-hexene, 1-octene, and 1-decene. As other monomers, conjugated dienes (for example, butadiene and isoprene) can be exemplified. Examples of the olefin resin include an ethylene resin, a propylene resin, a butene resin, a poly (4-methyl-1-pentene) resin, a mixture of these resins, and a recycled resin thereof.

The ethylene resin is a thermoplastic resin having a polyethylene crystal structure, and is preferably a thermoplastic ethylene polymer resin containing 50% by weight or more of a repeating unit derived from ethylene, and is preferably a homopolymer of ethylene,
More preferred is a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms, or a copolymer of ethylene and at least one other monomer. As the olefin, propylene, 1-butene, 4-methyl-1-pentene, 1
-Hexene, 1-octene and 1-decene can be exemplified. Other monomers include conjugated dienes (eg, butadiene and isoprene) and non-conjugated dienes (eg, 1,4-
Examples thereof include pentadiene), acrylic acid, acrylic acid esters (eg, methyl acrylate and ethyl acrylate), methacrylic acid, methacrylic acid esters (eg, methyl methacrylate and ethyl methacrylate), and vinyl acetate.

Examples of the ethylene resin include low density polyethylene; medium density polyethylene; high density polyethylene;
Ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-
A copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms, such as an octene copolymer and an ethylene-1-decene copolymer; a copolymer of ethylene and a conjugated diene (for example, butadiene or isoprene); A copolymer of ethylene and a non-conjugated diene (for example, 1,4-pentadiene); a copolymer of ethylene and acrylic acid, methacrylic acid or vinyl acetate; and a resin such as α, β-
Examples include resins modified (eg, graft-modified) with unsaturated carboxylic acids or derivatives thereof (eg, acrylic acid or methyl acrylate), or alicyclic carboxylic acids or derivatives thereof (eg, maleic anhydride).

The propylene-based resin is a resin having an isotactic polypropylene crystal structure, and is preferably a thermoplastic propylene polymer resin containing 50% by weight or more of a repeating unit derived from propylene, and a propylene homopolymer, Propylene and α having 2 to 10 carbon atoms
-Copolymers with olefins (excluding propylene) or propylene with at least one other monomer are more preferred. As the α-olefin, ethylene, 1-butene, 4-methyl-1-pentene, 1
-Hexene, 1-octene and 1-decene can be exemplified. As other monomers, conjugated dienes (for example, butadiene and isoprene) can be exemplified.

The butene-based resin is a thermoplastic 1-butene polymer resin containing 50% by weight or more of a repeating unit derived from 1-butene, and is a homopolymer of 1-butene or at least 1-butene. Copolymers with one other monomer are preferred. Other monomers having 2 carbon atoms
Examples of the olefin include ethylene, propylene, 4-methyl-1-pentene, 1-hexene, 1-octene, and 1-decene. . Conjugated dienes (for example, butadiene and isoprene) can be exemplified as monomers other than olefins. For example, poly-1-butene can be exemplified as the butene-based resin.

The poly (4-methyl-1-pentene) resin is a thermoplastic 4-methyl-pentene resin containing 50% by weight or more of a repeating unit derived from 4-methyl-1-pentene.
It is a 1-pentene polymer, and is preferably a homopolymer of 4-methyl-1-pentene or a copolymer of 4-methyl-1-pentene and at least one other monomer. Examples of other monomers include olefins having 2 to 10 carbon atoms (excluding 4-methyl-1-pentene), and ethylene, propylene,
-Butene, 1-hexene, 1-octene and 1-decene can be exemplified. Conjugated dienes (for example, butadiene and isoprene) can be exemplified as monomers other than olefins.

The olefin resin (Y) is preferably a propylene resin from the viewpoints of flexibility, transparency, processability and heat resistance, and has a Young's modulus of 600 MPa in both MD and TD directions according to the method specified in ASTM D882. The above propylene-based resin is more preferable, and the propylene-based resin of 800 MPa or more is further preferable. When the Young's modulus is in this range, the rigidity is more excellent, which is preferable. As the propylene-based resin used as the olefin-based resin (Y), a propylene homopolymer is preferably excellent in heat resistance and transparency, and its MFR is preferably 2 to 20 g / 10 min.
-14 g / 10 min is more preferred. When the MFR is in this range, the film is more excellent in processability and is preferable. MF
R is measured by a method specified in JIS K6758.

Each resin used in the present invention may be used in combination with various additives, if necessary. Antioxidants, stabilizers, antistatic agents, nucleating agents, pressure-sensitive adhesives And anti-fogging agents.

The thickness of the easily tearable film of the present invention is usually 5 to 100 μm, preferably 7 to 50 μm.

[0032]

EXAMPLES The present invention will be described based on examples, but the present invention is not limited to these examples. Physical properties in the examples were determined by the following methods.

1. Intrinsic viscosity of polymer (unit: dl /
g): Measurement was performed in 135 ° C. tetralin using an Ubbelohde viscometer. In addition, the intrinsic viscosity of the crystalline propylene polymer portion (b) in Reference Example 1 below was determined from the crystalline propylene polymer portion (a) and the intrinsic viscosity of the entire polymer using the calculation formula described in the specification. Was.

2. Melt flow rate (MFR): JI
The measurement was performed at 230 ° C. according to the method of Condition 14 of SK7210. (Unit: g / 10
Minutes)

3. Die swell ratio (SR): JIS K
The diameter of the cross section of the extrudate at the time of measuring the melt flow rate (MFR) according to the method of Condition 14 of 7210 was measured and determined by the following equation. Die swell ratio = diameter of cross section of extrudate / diameter of orifice However, cross section of extrudate refers to a cross section perpendicular to the extrusion direction of the extrudate, and when the cross section is not a perfect circle, the maximum diameter of the cross section The average of the values and the minimum was taken as the diameter of the cross section of the extrudate.

4. Molecular weight distribution: G. P. C. (Gel permeation chromatography) was measured under the following conditions. The molecular weight distribution was evaluated by the ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn). Model: 150CV type (Millipore Waters) Column: Shodex M / S 80 Measurement temperature: 145 ° C Solvent: orthodichlorobenzene Sample concentration: 5 mg / 8 mL

5. Maximum melting peak temperature (Tm): Using a differential scanning calorimeter manufactured by PerkinElmer, a sample of 10 m
g was held at 220 ° C. for 5 minutes under a nitrogen atmosphere to melt the sample. Next, the temperature was lowered from 220 ° C. to 40 ° C. at a rate of 5 ° C./min. Then, at 40 ° C
To 180 ° C. at a rate of 5 ° C./min to obtain a melting endothermic curve. The peak temperature at the highest peak height of the obtained melting endothermic curve was defined as the highest melting peak temperature (Tm) of the sample. In addition, 5 ° C was measured using the differential scanning calorimeter.
The melting point of indium (In) measured at a heating rate of / min was 156.6 ° C.

6. Tear strength: MD direction and TD of the film according to the method specified in JIS Z 1702.
The measurements were taken in each of the directions. Generally, the smaller the value, the better the easy tearing property, preferably 20 kN / m or less, more preferably 10 kN / m or less.

7. Easy tearing property The easy tearing property of the film was evaluated by the following four stages when the film was torn with bare hands. ◎ Easy to tear. ○ Some resistance but tearing. C: The film partially stretched, and although it was difficult, it was torn. × It cannot be torn with bare hands.

8. Tensile breaking elongation: JIS P8116
In the MD and TD directions of the film in accordance with the method specified in the above. Generally, the smaller the value, the better the easy tearing property, preferably 500% or less, more preferably 200% or less.

9. All haze (transparency): JIS K71
05. Usually, the smaller the value, the higher the transparency, preferably 30% or less, particularly preferably 10% or less.

10. Young's modulus: According to the method specified in ASTM D882. The larger the value is, the higher the rigidity is.
It is particularly preferably at least MPa. The MD and TD directions were measured. However, test specimen shape: strip type of 20 mm × 120 mm Distance between chucks: 50 mm Peeling speed: 5 mm / min

11. Heat resistance (heat resistance temperature): The heat resistance temperature was measured according to the following procedure with reference to Tokyo Notification No. 1027 “Quality indication of wrap film”. (1) A strip-shaped film test piece having a width of 3 cm and a length of 14 cm, and two boardboards having a width of 3 cm and a length of 2.5 cm are prepared. (2) The respective upper and lower 2.5 cm and 2.5 cm portions in the length direction of the test piece are superimposed on a board, and both are fixed with an adhesive tape. (3) The portion of the test piece that overlaps the upper paperboard is fixed to a jig, and a load of 10 g is applied to the lower part of the test piece that overlaps the paperboard. (4) Put it quickly in an air oven adjusted to a constant test temperature, heat it for 1 hour, and examine whether the test piece after heating is cut or not. (5) If the test piece did not cut after 1 hour,
Raise the test temperature by 10 ° C (the cut-off temperature described in Tokyo Notification No. 1027 “Quality indication of wrap film” is 5 ° C) and repeat the above operation using another new strip-shaped film test piece. repeat. After one hour, if the test piece is cut, the test temperature is lowered by 10 ° C., and the above operation is repeated using another new strip-shaped film test piece. (6) The maximum temperature at which the test piece does not cut is defined as the "heat-resistant temperature" of the test piece.

[Reference Example 1] (Production of one example of propylene polymer (T)) [1] (Synthesis of solid catalyst component) After replacing a 200-liter SUS reaction vessel equipped with a stirrer with nitrogen, 80-liter of hexane was added. 6.55 mol of tetrabutoxytitanium, diisobutyl phthalate
8 mol and 98.9 mol of tetraethoxysilane were added to obtain a uniform solution. Next, 51 l of a solution of butylmagnesium chloride in diisobutyl ether having a concentration of 2.1 mol / l was gradually dropped over 5 hours while maintaining the temperature in the reaction vessel at 5 ° C. After completion of the dropwise addition, the mixture was further stirred at room temperature for 1 hour, then solid-liquid separated at room temperature, and washing with 70 l of toluene was repeated three times. Then
Toluene was added so that the slurry concentration was 0.6 kg / liter, then a mixed solution of 8.9 mol of n-butyl ether and 274 mol of titanium tetrachloride was added, and 20.8 mol of phthalic chloride was further added to obtain 110. Stirring was performed at ℃ for 3 hours. Thereafter, solid-liquid separation is performed, and toluene
Two 90 liter washes were performed. Next, after adjusting the slurry concentration to 0.6 kg / liter, 3.13 mol of diisobutyl phthalate and n-butyl ether 8.
9 mol and 137 mol of titanium tetrachloride were added,
For 1 hour. Then, after the solid-liquid separation at the same temperature, washing with 90 liters of toluene at 95 ° C. was performed twice. Next, after adjusting the slurry concentration to 0.6 kg / liter, 8.9 mol of n-butyl ether and 137 mol of titanium tetrachloride were added, and the mixture was stirred at 95 ° C. for 1 hour. Thereafter, solid-liquid separation was performed at the same temperature, and washing with 90 liters of toluene was performed three times at the same temperature. Next, after adjusting the slurry concentration to 0.6 kg / liter, 8.9 mol of n-butyl ether and 137 mol of titanium tetrachloride were added, and the mixture was stirred at 95 ° C. for 1 hour. Thereafter, solid-liquid separation was performed at the same temperature, washing was performed three times with 90 liters of toluene at the same temperature, further, washing was performed three times with 90 liters of hexane, followed by drying under reduced pressure to obtain a solid catalyst component 11.0.
Kg was obtained. The solid catalyst component contains 1.9% by weight of titanium atom, 20% by weight of magnesium atom, 8.6% by weight of phthalic ester, 0.05% by weight of ethoxy group, and 0.21% by weight of butoxy group. Particle properties.

[2] (Pre-activation of solid catalyst component) 1.5 L of n-hexane, 37.5 mmol of triethylaluminum, which had been dehydrated and degassed in an autoclave with an internal volume of 3 L made of SUS and sufficiently equipped with a stirrer,
t-butyl-n-propyldimethoxysilane 3.75
Mmol, 15 g of the solid catalyst component obtained in the above [1]
Was added, and 15 g of propylene was continuously supplied over 30 minutes while maintaining the temperature in the tank at 5 to 15 ° C. to perform preactivation.

[3] (Polymerization of Crystalline Propylene Polymer Part (a)) In a SUS 300 liter polymerization tank, liquid propylene was maintained at a polymerization temperature of 60 ° C. and a polymerization pressure of 27 kg / cm ² G. While supplying triethylaluminum at 1.3 mmol / h, t
0.13 mmol / h of -butyl-n-propyldimethoxysilane and 0.51 g / h of a solid catalyst component preactivated in the same manner as in the above [2] are continuously supplied,
Propylene polymerization was carried out in the substantial absence of hydrogen,
kg / h of polymer were obtained. At this time, the amount of the produced polymer was 3920 g per 1 g of the solid catalyst component. A part of the sample was sampled and analyzed. As a result, the intrinsic viscosity was 7.7 d.
1 / g. The obtained polymer was continuously transferred to the second tank as it was.

[4] (Polymerization of Crystalline Propylene Polymer Part (b)) In a fluidized bed reactor with a stirrer having an internal volume of 1 m ³ (second tank), a polymerization temperature of 80 ° C. and a polymerization pressure of 18 kg / cm.
² G, while supplying propylene and hydrogen so as to maintain a hydrogen concentration of 8 vol% in the gas phase, the catalyst-containing polymer and triethylaluminum transferred from the first tank and 60 mmol / h, t-butyl-n- By continuing propylene polymerization continuously while supplying 6 mmol / h of propyldimethoxysilane, a polymer of 18.2 kg / h was obtained. The intrinsic viscosity of this polymer is 1.9 dl
/ G. From the above results, the amount of polymer produced during the polymerization of (b) was 31760 g per gram of the solid catalyst component, the polymerization weight ratio of the first tank and the second tank was 11:89, and the extreme of (b) The viscosity was determined to be 1.2 dl / g.

[5] (Pelletization of Polymer) 0.1 part by weight of calcium stearate and 100 parts by weight of Irganox 10 were added to 100 parts by weight of this polymer powder.
10 (manufactured by Ciba-Geigy) and 0.2 part by weight of Sumilyzer BHT (manufactured by Sumitomo Chemical Co., Ltd.) were added and melt-kneaded at 230 ° C. to obtain a weight average molecular weight (Mw).
Is 3.4 × 10 ⁵ , and the molecular weight distribution (Mw / Mn) is 8.
0, MFR is 12g / 10min, Die swell ratio (SR)
Of 2.4 were obtained.

Example 1 A single-layer film was obtained from the propylene homopolymer of Reference Example 1 using a co-extrusion T-die film forming machine manufactured by CBC Tech Co., Ltd. For film formation, a single extruder having a diameter of 50 mm and an L / D of 32 was used to melt and knead the resin at 280 ° C., and the temperature was adjusted to 280 ° C. via a feed block.
Then, it was cooled and solidified by taking it out with a chill roll at 20 ° C., and an unstretched monolayer film having a total thickness of 12 μm was wound around a paper tube at a line speed of 50 m / min. Table 1 shows the physical properties of the film.

Example 2 As resins, 50 parts by weight of propylene homopolymer PF814 (Die swell ratio = 2.4) manufactured by Montell JP Corporation and propylene homopolymer (manufactured by Sumitomo Chemical Co., Ltd.): A film was obtained in the same manner as in Example 1, except that 50 parts by weight of trade name Noblen Y501N, die swell ratio = 1.4) were used. Table 1 shows the physical properties of the film.

Example 3 A film was obtained in the same manner as in Example 1 except that propylene homopolymer PF814 (die swell ratio = 2.4) manufactured by Montell JP Corporation was used as the resin. Table 1 shows the physical properties of the film.

Comparative Example 2 As a resin, the melting point was 161 ° C.
A film was obtained in the same manner as in Example 1 except that a propylene homopolymer (manufactured by Sumitomo Chemical Co., Ltd., trade name: Noblen Y501N) having an MFR of 12 g / 10 min was used. Table 1 shows the physical properties of the film.

[0053]

[Table 1]

[0054]

According to the present invention, an easily tearable film having good tearability and rigidity is provided. The easily tearable film of the present invention also has excellent transparency, heat resistance, and rigidity, and is preferably used in food packaging, textile packaging, and other wide-ranging applications.

Continued on the front page F-term (reference) 4F071 AA12 AA12X AA15 AA15X AA20 AA20X AA21 AA21X AA28 AA28X AA32 AA32X AA33 AA33X AA81 AA88 AF16 AH04 BA01 BB06 BC01 4J002 BB032 BB06 BB06 BB06 ABB02 BB05 ABB02 BB05A AA17Q AA19Q AA21Q AS02Q AS03Q CA01 CA04 DA04 DA09 FA34 JA58

Claims (3)

[Claims] 1. A propylene resin (X) having a die swell ratio of 1.8 or more is 20 to 100% by weight, and an olefin resin (Y) different from the propylene resin (X) is 80 to 100% by weight.
An easily tearable film comprising a resin composition containing 0% by weight. 2. The propylene resin (X) having an intrinsic viscosity of 5
Propylene polymer obtained by a polymerization method including a step of producing a crystalline propylene polymer portion (A) of dl / g or more and a step of producing a crystalline propylene polymer portion (B) having an intrinsic viscosity of less than 3 dl / g (T) wherein the content of the crystalline propylene polymer portion (A) in the propylene polymer (T) is 0.05% by weight or more and less than 35% by weight, and Intrinsic viscosity is 3dl
The easily tearable film according to claim 1, which is a propylene polymer (T) having a molecular weight distribution of less than 10 / g and a molecular weight distribution of less than 10. 3. An olefin resin (Y) according to ASTM D
3. The easily tearable film according to claim 1, wherein the film is a propylene-based resin having a Young's modulus of 600 MPa or more in both the MD and TD directions according to the method specified in 882.