JPH01104640A - Resin composition and shrink packaging film - Google Patents

Abstract

PURPOSE:To obtain a resin composition, having excellent low temperature shrinkability, transparency, etc., with hardly any amount extracted with a solvent and suitable as shrink packaging films suited for food sanitation uses, by blending specific amounts of a specified propylene random copolymer with a specific propylene-alpha-olefin copolymer. CONSTITUTION:A resin composition obtained by blending (A) 5-90wt.%, 10-85wt.% copolymer of propylene random copolymer having 4-15wt.% comonomer content, <=122 deg.C Vicat softening point and <=15wt.% content of part soluble in cold xylene with (B) 95-10wt.%, preferably 90-15wt.% copolymer of propylene and a >=4C alpha-olefin or further ethylene having 8-35mol.% >=4C alpha-olefin content and <=5mol.% ethylene content, 15-70mol.% content of a portion soluble in cold xylene, <=5wt.% (DELTAHa2e) and <=40wt.% amount extracted with a solvent, forming a film and subjecting the resultant film to drawing treatment.

Description

[Detailed description of the invention] <Industrial application field> The present invention has excellent low-temperature shrinkability and transparency.

The present invention relates to a resin composition that has good gloss and anti-blocking properties, and has a small amount of solvent extraction (1), which can be used as a shrink-wrapping film suitable for food hygiene applications, and a shrink-wrap film.

<Conventional technology> Currently, it is used as a material for shrink wrapping film.

Polyvinyl chloride, polyethylene, polypropylene, and the like are known, but each has advantages and disadvantages, and none that are satisfactory in all respects has yet been obtained.

Polyvinyl chloride has excellent transparency and low-temperature shrinkability, but it has poor low-temperature resistance and resistance to fused seals.
Furthermore, there are food hygiene and disposal problems associated with plasticizers.

As for polyethylene, films made from linear low-density polyethylene and subjected to biaxial stretching are available.
The transparency is poor (and the low-temperature shrinkability has not reached a satisfactory level).

On the other hand, there are propylene-ethylene random copolymers made from polypropylene and copolymerized with 3 to 5 wt% ethylene, and propylene copolymerized with 1 to 3 wt% ethylene and 3 to 1 wt% butene-1. -Ethylene-phthene-1. Ternary random copolymer (Unexamined Japanese Patent Publication No. 5
2-16588) has been biaxially stretched, but its low-temperature shrinkability is unsatisfactory. In order to improve this low-temperature shrinkability, a propylene-ethylene random copolymer with a further increased ethylene content was used.

Stretched films lose their transparency, and some even bleed and turn white over time.

It is not preferable because the blocking resistance is poor.

Next, even within the same propylene copolymer.

JP-A-53-113692 and JP-A-60-12
Publication No. 7133 discloses a film formed by stretching a specific propylene-α-olefin copolymer, but although it has good low-temperature shrinkability and transparency, it has a large amount of solvent extraction. .

Moreover, the former type has poor blocking resistance.

Japanese Patent Publication No. 57-24375 discloses a film obtained by stretching a composition of a propylene-butene-1 random copolymer and isotactic polypropylene. However, according to the knowledge of the present inventor, what is shown there is.

If the amount of solvent extracted is large or isotactic polypropylene is blended, low-temperature stretchability may be poor, and low-temperature shrinkage properties may not be exhibited, or blocking resistance may be poor.

Method of blending petroleum resin with propylene copolymer (
JP-A-49-9%-45, JP-A-62-4735) are also known to include 1 petroleum resin, which certainly improves low-temperature shrinkability, but This is not preferable because the anti-blocking property is deteriorated when the film is coated with water, and the film tends to naturally shrink over time. Furthermore, since petroleum resins are more expensive than propylene copolymers, they increase costs and are not preferred.

<Problems to be Solved by the Invention> In view of the above-mentioned circumstances, the present inventors have developed a material that has significantly superior low-temperature shrinkage properties, good transparency, gloss, and anti-blocking properties, and has a low solvent extraction amount. The object of the present invention is to provide at least two resin compositions suitable for shrink-wrapping films suitable for food hygiene purposes, and uses thereof.

Means for Solving the Problems> The present invention provides a method for solving problems in at least one axial direction after film formation by using a resin composition comprising a specific propylene-α-olefin copolymer and a specific propylene random copolymer. The present invention has been completed based on the discovery that a shrink wrapping film having all of the above characteristics can be obtained by carrying out a stretching treatment.

That is, one aspect of the present invention is.

(2) A propylene random copolymer, which has a comonomer content of 4 to 15 wt%, a Vicat softening point of I22°C or less, and a cold xylene soluble portion of 15 wt% or less, and (B) fluoropylene and An α-olefin having 4 or more carbon atoms, or a copolymer of propylene, an α-olefin having 4 or more carbon atoms, and ethylene, the content of which is 8 to 35 mol% of α-olefin having 4 or more carbon atoms. ■ I-, f 1/7 content of fi is 5 mol% or less 0
Two components (A1.' (B) with a cold xylene soluble portion of 15 to 70 Wt %, and (A) 5 to 9 W
t%. (This invention relates to a resin composition characterized by containing 195 to 10 wt% of B, and a film for shrink wrapping which is formed by stretching the resin composition in at least one axis direction after being formed into a film.)

The present invention will be explained in detail below.

The propylene random copolymer used in the composition of the present invention is a well-known crystalline ethylene-propylene random copolymer or an ethylene-butene-1-propylene random terpolymer, but the comonomer content is 4 to 4. A so-called slurry polymerized product having a content of 15 wt% and in which components soluble in an (inert) solvent are removed is preferred.

In the present invention. The Vicat softening point of the propylene random copolymer (hereinafter abbreviated as copolymer part) is 122°C or lower, preferably 120'C or lower. If a copolymer portion with a Vicat softening point exceeding the upper limit is used, low-temperature stretchability will be poor and low-temperature shrinkability will be poor. In order to improve the low-temperature shrinkability, copolymer (B), which is another component,
This is not preferable because the amount of the solvent becomes very large, and as a result, the blocking resistance becomes poor and the amount of solvent extracted becomes large. What the inventors discovered.

Surprisingly, if the Vicat softening point of copolymer (2) is 122°C or lower, the amount of solvent extraction can be achieved at a satisfactory level in the composition with the specific copolymer defined as copolymer (B). Excellent low-temperature shrinkability can be achieved while keeping the shrinkage low.

The cold xylene soluble part of the copolymer in the present invention (hereinafter referred to as
(abbreviated as CXS) is 15wt% or less, and 13w
It is preferably at most t%, more preferably at most 10wt%. When CXS exceeds the upper limit,
The amount of solvent extracted is large (which is not desirable).

Melt index (g/
10 minutes) is preferably 0.5 to 50 g/10 minutes.

Propylene and an α-olefin having 4 or more carbon atoms used in the composition of the present invention, or propylene and an α-olefin having 4 or more carbon atoms.
A copolymer (B) of olefin and ethylene (hereinafter abbreviated as copolymer (B)) can be produced by a solvent polymerization method in which the copolymer is polymerized in a solvent;
Alternatively, it can be produced by a gas phase polymerization method in which polymerization is carried out in a gas phase, but in particular, a gas phase polymerization method in which polymerization is carried out in the absence of a liquid solvent is suitable for the present invention.
B) (having an appropriate cold xylene soluble portion) is easy to obtain, and it is also economically superior because the polymer drying process or solvent purification process is omitted or greatly simplified. can be.

In addition, since it is obtained in powder form, it is preferable because the additives can be easily dispersed when preparing two compositions.

Furthermore, it is preferable not to take measures such as peroxide decomposition before preparing the second composition, since the powder form can be maintained.

When producing by gas phase polymerization, it can be carried out using a known fluidized bed reactor, a fluidized bed reactor equipped with a stirrer, a reactor equipped with a stirrer, or the like. Bipolymerization is performed at a temperature at which the gas does not liquefy in the reactor and the polymer particles do not melt into agglomerates.

It is essential to carry out the polymerization under pressure conditions, and preferable polymerization conditions include a temperature range of 40 to 100 °C and a temperature range of 1 to 5 °C.
0kg/c:m2 (gauge pressure, hereinafter abbreviated as G, pressure range of D, 50-80℃, 2-20kg/cm2
G is more preferred. Further, for the purpose of controlling the melt fluidity of the obtained polymer, it is preferable to add a molecular weight regulator such as hydrogen. Polymerization is batch polymerization.

Alternatively, continuous polymerization or a combination of the two can be carried out, and the monomer and molecular weight regulator consumed in the 9-polymerization can be continuously or intermittently supplied to the reactor. can do. In addition, for copolymerization, a random copolymer, which is polymerized by simultaneously supplying a monomer and a comonomer at a constant composition, is preferably employed.
Polymerization can also be carried out by changing the composition of monomers to be polymerized in stages and continuously. After one polymerization, the obtained copolymer can be washed with alcohols or hydrocarbon solvents for the purpose of removing catalyst residues or low molecular weight polymers.

The catalyst system used in the production of the copolymer (B) used in the composition of the present invention is a known catalyst for stereoregular polymerization of α-olefins, and is a so-called Ziegler-Natsuta catalyst, i.e. It consists of a catalyst system containing a transition metal compound of Groups ■~■ and a typical metal organic compound of Groups ■~■ of the periodic table, and preferably contains a third component such as an electron-donating compound. It is preferable that the transition metal compound or the catalyst component containing it is solid.

There is TiCl3 as a transition metal compound, but α.

It is known that αs7'+ and δ types, which have one-layer crystallinity, are required for stereoregular polymerization of α-olefins having 3 or more carbon atoms. TiCl3 is preferred.

Ti01s is generally obtained as a TiCb composition by reducing TiCl4 with hydrogen, metallic aluminum, metallic titanium, an organoaluminum compound, an organomagnesium compound, or the like. A preferred TiCl3 composition is Ti
This is so-called TiCls・AA, which is obtained by reducing Cl4 with metallic aluminum and further activating it by mechanical crushing, etc. TiCl4 is reduced with an organic aluminum compound,
Furthermore, Ti activated using a complexing agent and a halogen compound
Cl3 compositions are more preferred. Also, Ti (OR)n
X4-n (R represents a hydrocarbon group having 1 to 20 carbon atoms; n represents the number of O to 4) An alkoxy group-containing compound obtained by reducing D with an organoaluminum compound and then treating with an ether compound and TiCL The trivalent titanium halide can be used more preferably.

TiC1g composition or alkoxy group-containing trivalent titanium halide in liquefied propylene.

6,000 per gram when polymerized in combination with diethylaluminium chloride in the presence of hydrogen at 65°C for 4 hours.
It is preferable to use one that can produce polypropylene of 1.5 g or more. Such a TiCl3 composition is disclosed in Japanese Patent Application Laid-open No. 47-1999.
34478, Japanese Patent Publication No. 55-27085, and Japanese Patent Application No. 57-26508.

It can be manufactured by the method disclosed in Japanese Patent Application No. 58-138471. Further, the alkoxy group-containing trivalent titanium halide can be produced by the method disclosed in JP-A-59-126401, JP-A-60-228504, and the like.

When a transition metal compound is used as a catalyst component supported on a suitable carrier, various solid polymers, especially α
- Polymers of olefins, various solid organic compounds, especially solid hydrocarbons, various solid inorganic compounds, especially oxides, carbonates, halides, etc. can be used. Preferred carriers are magnesium compounds, ie, magnesium halides, oxides, hydroxides, hydroxyhalides, and the like. Magnesium compounds can be used as complexes with other solid substances mentioned above. Commercially available magnesium compounds can be used as they are, but they can be mechanically pulverized, dissolved in a solvent and precipitated, treated with an electron-donating compound or active hydrogen compound, or treated with an organic compound such as a Grignard reagent. Preferably, it is a magnesium compound obtained by decomposing a magnesium compound. In many cases, it is preferable to use these operations in combination to obtain a preferable magnesium compound, and these operations may be carried out in advance when producing the carrier, or may be carried out when producing the catalyst component. Particularly preferred magnesium compounds are magnesium halogen compounds, and particularly preferred transition metal compounds are the above-mentioned titanium halogen compounds. titanium, magnesium,
A carrier-attached catalyst component containing chlorogen as a main component is one of the more preferable catalyst components in the present invention, but
It can be manufactured by the method disclosed in JP-A No. 6-30407, JP-A-57-59915, and the like. In the present invention, among these, the supported catalyst component contains an electron-donating compound and has titanium, magnesium, and halogen as main components.

It is one of the more preferred catalyst components.

It is not a carrier-supported type, but titanium and magnesium.

A composite catalyst containing halogen and an electron-donating compound as main components is also one of the more preferred catalyst components in the present invention. It can be manufactured by the method disclosed in Japanese Patent Application No. 60-59792.

Preferred are organic compounds of aluminum, especially those having the formula Ra1) (A) X3-e (R is 1 to 2 carbon atoms).
0 hydrocarbon group, X represents hydrogen or )\logen,
e is a number from 1 to 3. ) is preferable.

Specific examples of such compounds include triethylaluminum, triisobutylaluminum, diethylaluminum hydride, diethylaluminium chloride, diethylaluminum bromide, and ethylaluminum sesquichloride.

Ethylaluminum dichloride and the like.

The most preferred compound is triethylaluminum.

diethylaluminum chloride, and mixtures thereof.

As the electron donating compound in the present invention.

Esters such as ethyl acetate, ε-caprolactone, methyl methacrylate, ethyl benzoate, ethyl p-anisate, methyl p-toluate, phthalic anhydride, or acid anhydrides, ethers such as di-n-butyl ether, diphenyl ether, and daidalam. Examples include organic phosphorus compounds such as tri-n-butyl phosphite, triphenyl phosphite, and hexamethylene phosphide triamide. Also includes ketones, amines, amides, and thioethers.

Or an alkoxysilane having a 5i-0-C bond,
Alternatively, organic silicon compounds such as aryloxysilane can also be used. In addition, the solid catalyst component may be prepolymerized by treating it with a small amount of olefin in the presence of an organoaluminum compound or an electron-donating compound prior to performing gas phase polymerization, for example. I can't help it.

The copolymer (B) used in the composition of the present invention contains a very small amount of α-olefin having 4 or more carbon atoms or ethylene as a comonomer.

As the α-olefin having 4 or more carbon atoms, butene-1,
Pentene-1, hexene-1,4-methylpentene-1
For example, when gas phase polymerization is carried out.

Butene-1 is the most preferred because it is difficult to liquefy and can maintain a high partial pressure.

The content of α-olefin having 4 or more carbon atoms in the copolymer (Bl) used in the composition of the present invention is 8 to 35 mol%,
9 to 30 mol% is preferable, and 10 to 26 mol% is more preferable. If the content of α-olefin having 4 or more carbon atoms exceeds the lower limit, the effect of improving the low-temperature shrinkability of the shrinkable film will be insufficient and undesirable, and if it exceeds the upper limit, the blocking resistance of the shrinkable film will decrease. This is not preferable because the properties are poor and the amount of solvent extracted is large.

The ethylene content of the copolymer (B) used in the composition of the present invention is 5 mol% or less, preferably 3 mol% or less.

If the ethylene content exceeds the upper limit, the transparency of the shrink film deteriorates over time, which is not preferable. The reason for this is
Although it is not clear, the bleed of the atactic component seems to be the cause.

The CXS of the copolymer (B) used in the composition of the present invention is:
It is 15 to 7 Qwt%, preferably 15 to 5 Qwt%.

More preferably 15 to 35 wt%.

When CXS is below the lower limit, the effect of improving the low-temperature shrinkability of the shrink film is insufficient and undesirable; when it is above the upper limit, the blocking resistance of the shrink film deteriorates, and the amount of solvent extracted This is not desirable.

ΔHaze of copolymer (B) used in the composition of the present invention
is preferably 5% or less, more preferably 4% or less, 3
% or less is more preferable.

If ΔHaze exceeds the upper limit, the transparency of the shrink film deteriorates over time and the blocking resistance deteriorates, which is not preferable.

The amount of solvent extraction of the copolymer (B) used in the composition of the present invention does not need to be particularly specified, but is preferably 40 wt% or less, more preferably 20 wt% or less.

If a solvent whose extraction amount is below the lower limit is used.

When blending with copolymer (2) etc., even if the blending ratio of copolymer (B) is increased, the amount of solvent extracted as one composition is
There is an advantage that the amount can be reduced by that much, which is preferable. The present inventor has discovered that if the specific copolymer (2) described above is used, the amount of solvent extracted as a 9 composition becomes a much smaller value than the value calculated from the additivity of both 9. That's what it means.

The composition used in the present invention has 5 to 90 wt of copolymer holes.
%, it is obtained by blending 95 to 10 wt % of copolymer (B), and the copolymer holes are 10 to 85 wt %.

The copolymer (Bl) is preferably blended in an amount of 90 to 15 wt%.

When the amount of copolymer holes exceeds the upper limit, the copolymer (
The blending amount of B) has to be lowered, and as a result, low-temperature shrinkability cannot be achieved, which is not preferable.

When the amount of copolymer holes is below the lower limit, the copolymer (
The amount of B) must be increased, which is undesirable because the amount of solvent extracted becomes large.

The melt index of the composition formulated as above (
g/10 minutes) is preferably 0.3 to 30 g/10 minutes. When the melt index is below the lower limit, extrusion processability deteriorates, which is undesirable. When the melt index exceeds the upper limit, film processability deteriorates, which is undesirable.

In the present invention, the above composition can be obtained by uniformly dispersing it by any known method. For example, extrusion melt blending.

Examples include the Banbury blend method. 9. Polymerization is carried out by changing the polymerization conditions in stages. It is also possible to obtain the above composition by a so-called multistage polymerization method.

Minor amounts of other polymeric materials can be blended into the compositions of the present invention. Also, antistatic agent.

Additives such as anti-blocking agents, lubricants, stabilizers, nucleating agents, etc. can be added.

As a method for forming a film from the composition of the present invention, known processing methods such as the T-die casting method and the water-cooled inflation method can be employed. or.

As a method for carrying out the stretching treatment, known l-axis stretching methods such as roll stretching, roll rolling, and tenter transverse l-axis stretching, as well as known biaxial stretching methods such as tenter biaxial stretching and tubular biaxial stretching, can be employed. . The stretching temperature is from room temperature to below the melting point (main peak) of the composition, but in order to improve the low-temperature shrinkability of the obtained film, it is preferably as low as possible within a range that allows uniform stretching. The magnification is preferably 2 to 10 times in uniaxial stretching, and 1.5 to 10 times in each axis in biaxial stretching.In this case, MD (longitudinal direction) and TD (transverse direction) The stretching ratio does not necessarily need to be balanced, and can be arbitrarily selected depending on each application.

In addition, the data and evaluation in Examples and Comparative Examples were performed according to the following method.

(1) α-olefin content in copolymer It was determined from the mass balance during polymerization. Further, the content of butene-1 was further determined using an infrared spectrophotometer using a +770 an-1 characteristic absorption using a conventional method.

Note that the measurements using an infrared spectrophotometer are for propylene-butene-1 copolymer.

A calibration curve was prepared and quantified based on the quantitative values obtained by CNMR.

(2) Ethylene content in the copolymer: 732 cm-1,720 cm- using an infrared spectrophotometer
It was determined by a conventional method from the characteristic absorption of +. In addition, in the measurement using an infrared spectrophotometer, a calibration curve was prepared and quantified based on the quantitative value obtained by radiation measurement of the ethylene copolymer labeled with 14c.

(3) Melt index (MI) ASTM-D1
Compliant with 238.

(4) Vicat Softening Point (VSP) Compliant with ASTM-DI525.

(5) Cold xylene soluble part (CXS) Dissolve 5 g of polymer in 500 ml of xylene.

Then, it is slowly cooled to room temperature. The mixture was then left in a bath at 20°C for 4 hours, filtered, and the filtrate was concentrated.

Dry, dry and weigh.

(6) Intrinsic viscosity ([η]) Concentrate the tetralin at 135°C using the usual method.

0.4. 0.2. 0.133 and 0.1 g/d
Measurements were made by changing 4 points.

(7) Create a press sheet of ΔHaze copolymer with a thickness of 100μ, and
It was expressed as the difference between the haze after annealing treatment at °C for 9 hours and the haze before treatment.

(8) Solvent extraction amount: Specified by FDA S 177, 1520-C'. This is the amount of n-hexane extracted at 50°C.

(9) Haze value (Haze) Conforms to ASTM-D100'3.

11G Heat shrinkage: Place a 5cm square film specimen in a glycerin bath at a specified temperature.
Measure the shrinkage rate of MD and TD when immersed for 0 seconds.

A force: 7 layers per 9 areas of 100 cm2 when two blocking films are stacked together.
Conditioning is carried out at 35° C. for 24 hours while applying a load of 1 kg.

After that, after being left at 23°C for 30 minutes, the two films were peeled off at a load increase rate of 10 g/min in a direction perpendicular to the film surface, the maximum load (g) at that time was determined, and the film area
It is expressed in terms of 00 cm2.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to Examples 7 unless the gist of the invention is exceeded.

Example 1 (1) Synthesis of solid product After purging a flask with an internal volume of 500 ml equipped with a stirrer and a dropping funnel with argon, 83 mL of n-heptane was added.
ml, 16.1 ml of titanium tetrachloride, and 51.0 ml of tetra-n-butoxytitanium were charged into a flask, and the temperature inside the flask was maintained at 20° C. while stirring. 162.1 ml of n-hebutane and 3 ml of diethylaluminum chloride
A solution consisting of 7.8 ml was added to the flask at a temperature of 20 ml.
The mixture was gradually added dropwise from the dropping funnel over a period of 3 hours while maintaining the temperature at °C. After the dropwise addition was completed, the temperature was raised to 50''C and stirred for 1 hour.

The mixture was allowed to stand at room temperature for solid-liquid separation, washed four times with 200 ml of n-hebutane, and then dried under reduced pressure to obtain 64.7 g of a reddish-brown solid product.

(2) Synthesis of prepolymerized solid After purging a 300 ml flask equipped with a stirrer with argon, 241 ml of n-hebutane, 34 g of toluethylaluminum, and the solid product 19 prepared in (1) above were added. .7 g was added to the flask and the temperature was maintained at 50°C. Next, while stirring, add ethylene to a partial pressure of 0.2
kg/cm2 and gradually fed into the suspension at 50°C for 20 minutes.

Preliminary polymerization treatment was performed. After the treatment, the solid-liquid was separated, washed twice with 50 ml of n-hebutane, and then dried under reduced pressure. The amount of prepolymerization is 0.0 1 polymer per 1 g of solid product.
It was 9g.

(3) Synthesis of solid catalyst component After purging the flask with an internal volume of 100 m1 with argon,
12.1 g of the prepolymerized solid prepared in (2) above and 42.3 ml of n-hebutane were charged into a flask, and the temperature inside the flask was maintained at 30°C.

Next, 14.4 ml of di-iso-amyl ether was added, and after treatment at 30°C for 1 hour, the temperature was raised to 75°C. 7
15.7 ml of titanium tetrachloride was added at 5°C, and the reaction was carried out at 75°C for 1 hour. After solid-liquid separation, n-hebutane 50
After repeating washing with m1 four times, drying was carried out under reduced pressure to obtain a solid component.

Furthermore, after purging the flask with an internal volume of 100 m1 with argon, 9.9 g of the above solid component and 38 m of n-hebutane were added.
1 was put into the flask, and the temperature inside the flask was maintained at 30°C. Next, 8.5 ml of di-iso-amyl ether was added, and the mixture was treated at 30°C for 1 hour, and then the temperature was raised to 75°C. Add 11.5 ml of titanium tetrachloride at 75°C and heat to 75°C.
The reaction was carried out for 1 hour. After solid-liquid separation, n-hebutane 50
After repeating washing with m1 four times, drying was carried out under reduced pressure to obtain a solid catalyst component.

(4) Copolymerization (copolymer (B)) Using a fluidized bed reactor with an internal volume of 1 m3 and equipped with a stirrer,
Copolymerization of propylene and butene-1 was carried out. First, 60 kg of propylene-butene-1 copolymer particles for catalyst dispersion were supplied to 9 reactors.

The reactor was then purged with nitrogen and then with propylene. Pressurize to 5 kg/cm2G with propylene,
Circulating gas was supplied from the bottom of the reactor at a flow rate of 30 m3/hr to keep the polymer particles in a fluidized state, and then the following catalyst was supplied to the reactor. As catalyst components (b) and (C), solutions diluted with hebutane were used.

(a) Solid catalyst component 21g (b)
Diethylaluminium chloride 156g (C
) Triethylaluminum 22g (dl
Next, 15 g of methyl methacrylate was supplied with hydrogen, propylene, and butene-1 so that the hydrogen concentration was 1.7 vol% and the butene concentration was 129 vol.
The pressure was increased to kg/Cm2G, and the temperature of the fluidized bed was adjusted to 70°C to start polymerization.

During the polymerization, hydrogen, propylene, and butene-1 were supplied so as to keep the concentration and pressure of hydrogen and butene-1 constant.

When the amount of polymerization reached 75 kg, 60 kg of polymer particles remained in the 9 reactor for catalyst dispersion in the next polymerization, and the remaining polymer particles were transferred to a stirring mixing tank, where they were mixed with 210 g of propylene oxide and methanol. Add ioo g.

It was treated at 80°C for 30 minutes. It was then dried to obtain a white powdery polymer. The same polymerization was repeated three times, and the physical properties of the finally obtained polymer (copolymer (B)) were measured.

Butene-1 content t is 20.3 mol%, CXS is 23.9
%, ΔHaze was 0.9%, solvent extraction amount was 7.3%, and intrinsic viscosity was 1.8 dl/g.

(5) Composition preparation Between copolymers Sumitomo Noblen ■RW160 was used.

The ethylene content of RW160 is 4.8 wt%.

The Vicat softening point was 118° C., the melt index was 8.8 g/10 min, and the CXS was 4.3%.

The above copolymer (A140wt% and the copolymer obtained in (4) (B160wt%) were homogeneously melt-blended in a 65φ extruder.As an antioxidant, BHTo,
1 part, 0.4 part of finely powdered aluminosilicate as an anti-blocking agent, and 0.2 part of erucic acid amide as a lubricant were added.

A 400 μm sheet of this resin composition was obtained by a pressing method, and a 90 square sheet was taken from it to obtain a biaxially stretched film under the following conditions.

Stretching machine: Tabletop biaxial stretching machine manufactured by Toyo Seiki Temperature: 280°C Preheating time = 3 minutes Stretching ratio: Mn 2x, TD 5x Stretching speed: 15 m/min (simultaneous biaxial stretching) Approximately 1
The physical properties of the 5 μm thick film are shown in Table 1 together with the physical properties of the composition. In addition, the shrinkage rate was shown as the average value of MD and TD.

This biaxially stretched film was made from a resin with a small amount of solvent extraction, and had excellent transparency, low-temperature shrinkability, and blocking resistance.

Example 2 The same copolymer and copolymer (B) used in Example 1 were used to prepare the 9 composition, except that the blending ratio and stretching temperature were changed to 90°C. A biaxially stretched film was obtained under the same conditions as in Example 1.

Table 1 shows the physical properties of the two compositions and the physical properties of the film. This biaxially stretched film had good properties as in Example 1.

Examples 3 and 4 (1) Polymerization of copolymer (Bl) Polymerization was carried out under the same polymerization conditions as in Example 1, except that the catalyst system used in Example 1 was used and the amount of butene-1 charged was changed. A copolymer was obtained.

The butene-1 content of the obtained copolymer (B) was 15.8
Mol%, CXS is 19.5wt%, ΔHaze is 0.4
%, solvent extraction amount is 6.2%, intrinsic viscosity is 1.8 dl
/g.

(2) Preparation of composition and production of stretched film Copolymerization winners I used Resident Noblen FL6711N.

FL67i1N tyrene content is 5.2 wt%.

Vicat softening point is 100℃, melt index is
5.5 g/10 min, CXS was 9.5 wt%.

Using the above copolymer (2), copolymer (Bl).

The conditions were the same as in Example 1, except that the blending ratio in preparing the composition and the stretching temperature were changed to 90°C.

Obtain a biaxially stretched film.

Table 1 shows the physical properties of the blending ratio 1 composition and the physical properties of the film. These biaxially stretched films had good properties similar to those of Example 1.

Example 5 (1) Polymerization of copolymer (B) The catalyst system used in Example 1 was used, except that the amount of butene-1 charged and the polymerization pressure was changed to 7 kg/cm2 G. A copolymer was obtained under the same polymerization conditions as in Example 1.

The resulting copolymer (butene-1 content of Bl was 24.5
Mol%, CXS is 33.5 wt%, ΔHaze is 16
4%, solvent extraction amount is 14.5%, intrinsic viscosity is 2.0
di/g (2) Preparation of composition and production of stretched film Copolymerization The same material as in Example 1 was used.

Using the above copolymer, copolymer (B).

The blending ratio in composition preparation and the stretching temperature were set to 90'C.
A biaxially stretched film was obtained under the same conditions as in Example 1, except that the following conditions were changed.

The physical properties of the 2nd composition and the physical properties of the film are shown in Table 1. This biaxially stretched film.

Similar to Example 1, it had good characteristics.

Example 6 (1) Polymerization of copolymer (B) In the catalyst system used in Example 1, triethylaluminum was removed and the amount of methyl methacrylate was changed to 8 g.
Others were reduced to.

Using the same catalyst system, changing the amount of butene-1 charged,
Other than newly introducing ethylene.

A copolymer was obtained under the same polymerization conditions as in Example 1.

The butene-1 content of the obtained copolymer (B) was 16.1
Mol%, ethylene content is 2.0 mol%.

CXS is 24.5wt%, ΔHaze is 1.3%
, the solvent extraction amount was 12.5%, and the intrinsic viscosity was 2. Or
It was H/g.

(2) Preparation of composition and production of stretched film Copolymerization success The same material as in Example 1 was used.

Using the above copolymer (2), the copolymer surface.

A biaxially stretched film was obtained under the same conditions as in Example 1, except that the blending ratio in preparing the composition and the stretching temperature were changed to 90°C.

Table 1 shows the physical properties of the composition with a blending ratio of 9 and the physical properties of the film.

This biaxially stretched film had good properties similar to those of Example 1.

Comparative Example 1 The copolymer used in Example 3 (Bl itself was used).

A biaxially stretched film was obtained under the same conditions as in Example 1, except that the stretching temperature was changed to 90°C. still.

Stretching at temperatures below 90°C was not possible. The physical properties of the film are shown in Table 1. This biaxially stretched film was made from a resin with a large amount of solvent extraction, and had poor blocking resistance.

Comparative Example 2 (1) Preparation of composition and production of stretched film ■ Copolymer (2), copolymer (Bl) The same one as in Example 1 was used.

Using the above copolymer, copolymer (B).

A biaxially stretched film was obtained under the same conditions as in Example 1, except that the blending ratio in preparing the composition and the stretching temperature were changed to 110°C. Note that stretching at temperatures below 110'C was impossible.

Table 1 shows the physical properties of the composition with a blending ratio of 9 and the physical properties of the film.

This biaxially stretched film had poor low-temperature shrinkability and was not preferred.

Comparative Example 3 (1) Preparation of composition and production of stretched film (2) Copolymer (2) Susumu Noblen (RW140) was used.

The ethylene content of RW140 is 3.7 wt%,
The Vicat softening point is 125°C.

The melt index was 8.3 g/10 minutes.

CXS is 3.8%.

0 Copolymer (Bl The same material as in Example 1 was used.

Using the above copolymerizer, copolymer B).

A biaxially stretched film was obtained under the same conditions as in Example 1, except that the blending ratio in preparing the composition and the stretching temperature were changed to 110°C. Note that stretching at a temperature below 11°C was impossible.

Blending ratio 9 The physical properties of the composition and the physical properties of the film are Shown in the table.

This biaxially stretched film had poor low-temperature shrinkability and was not preferred.

Comparative Example 4 (1) Preparation of composition and production of stretched film ■ Copolymer (2) The same copolymer as in Example 1 was used.

■ Copolymer (B) A propylene-butene copolymer obtained by slurry polymerization using n-hebutane as a solvent, from which components soluble in n-hebutane have been removed. Butene-1 content was 15.1 mol%, and CXS was 10.1 wt%.

△Haz e is 0.5%, solvent extraction amount is 3.0wt
%, and the intrinsic viscosity number is 1.9 di/g.

Using the above copolymer (2), copolymer fBl.

A biaxially stretched film was obtained under the same conditions as in Example 1, except that the blending ratio in preparing the composition and the stretching temperature were changed to 100°C. Note that stretching at temperatures below 100°C was impossible.

Table 1 shows the physical properties of the 2 compositions and the physical properties of the film.

This biaxially stretched film has low-temperature shrinkability.

I didn't like it.

Comparative Example 5 (1) Preparation of composition and production of stretched film (1) Copolymer interpolator Nobu Ren RW120 was used.

The ethylene content of RW120 is 2.3 wt%,
The Vicat softening point is 137°C.

The melt index was 9.1 g for 710 minutes.

CXS is 3.2%.

(2) Copolymer B) A propylene-butene-1 random copolymer called Tafmer@xR110T manufactured by Mitsui Petrochemicals was used. The butene-1 content of TAFMER XRIIOT used was 26.5 mol%.

CXS is 52wt%, ΔHaze is 2.5%, solvent extraction amount is 59wt%, and intrinsic viscosity is 1.8dl.
/g.

Using the above copolymer, copolymer (B).

A biaxially stretched film was obtained under the same conditions as in Example 1, except that the blending ratio in preparing the composition and the stretching temperature were changed to 90°C. Table 1 shows the physical properties of the composition with a blending ratio of 9 and the physical properties of the film.

This biaxially stretched film was not preferred because it was made from a resin with a large amount of solvent extraction and had poor blocking resistance.

Comparative Example 6 The same copolymer (2) used in Example 1 was used, except that the stretching temperature was changed to 110°C.

A biaxially stretched film was obtained under the same conditions as in Example 1. still,
Stretching at temperatures below 110°C was not possible. The physical properties of the film are shown in Table 1.

This biaxially stretched film had poor low-temperature shrinkability.

Comparative Example 7 The same copolymer (2) used in Example 3 was used, except that the stretching temperature was changed to 100'C.

A biaxially stretched film was obtained under the same conditions as in Example 1. still,
Stretching at temperatures below 100°C was not possible. The physical properties of the film are shown in Table 1.

This biaxially stretched film had poor transparency and poor low-temperature shrinkability.

<Effects of the Invention> The resin composition of the present invention has excellent low-temperature shrinkability, and
Excellent transparency and blocking resistance.

Moreover, a shrink wrapping film made of a raw material with a small amount of solvent extraction was obtained.

Claims (6)

[Claims] (1) (A) A propylene random copolymer, which [1] has a comonomer content of 4 to 15 wt%, [2] has a Vicat softening point of 122°C or less, and [3] has a cold xylene soluble portion of 15 wt%. % or less, and (B) a copolymer of propylene and an α-olefin having 4 or more carbon atoms, or a copolymer of propylene, an α-olefin having 4 or more carbon atoms, and ethylene, whose [1] carbon number 4 or more α-olefin content is 8 to 35 mol% [2] Ethylene content is 5 mol% or less [3] Cold xylene soluble portion is 15 to 70 wt%2
Consisting of components (A) and (B), and (A) 5 to 90wt
%, (B) 95 to 10 wt%. (2) The resin composition according to claim 1, wherein component (B) has a ΔHaze of 5% or less. (3) The resin composition according to claim 1 or 2, wherein the amount of solvent extraction of component (B) is 40 wt% or less. (4) (A) A propylene random copolymer, which has [1] a comonomer content of 4 to 15 wt%, [2] a Vicat softening point of 122°C or lower, and [3] a cold xylene soluble portion of 15 wt%. % or less, and (B) a copolymer of propylene and an α-olefin having 4 or more carbon atoms, or a copolymer of propylene, an α-olefin having 4 or more carbon atoms, and ethylene, whose [1] carbon number 4 or more α-olefin content is 8 to 35 mol% [2] Ethylene content is 5 mol% or less [3] Cold xylene soluble portion is 15 to 70 wt%2
Consisting of components (A) and (B), and (A) 5 to 90wt
%, (B) 95 to 10 wt % is formed into a film and then subjected to stretching treatment in at least one axis direction. (5) The shrink wrapping film according to claim 4, wherein the component (B) has a ΔHaze of 5% or less. (6) The shrink wrapping film according to claim 4, wherein the solvent extraction amount of component (B) is 40 wt% or less.