JP2576078B2 - Thermoplastic resin film with antistatic properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin film. More specifically, the present invention relates to a thermoplastic resin film having excellent antistatic properties which can be suitably used as, for example, a packaging material.

[0002]

2. Description of the Related Art In general, a thermoplastic resin film generates a large amount of static electricity because of its high hydrophobicity. Therefore,
When such a film is used, for example, as a packaging material, dust adheres to it, causing a decrease in the commercial value of the contents, poor printing, uneven edges at the time of winding, and the like. In some cases, a shock may be given to the human body, and there is a problem such as ignition in an atmosphere using a flammable organic solvent.

Therefore, conventionally, in order to impart antistatic properties to the foam, a method of adding or coating an anionic, cationic or amphoteric surfactant has been adopted.

However, in the above-mentioned method, since the surfactant has a relatively small molecular weight of at most about 500 to 600, the surfactant volatilizes during the production of the film or bleeds over time after the film is formed. Out, contaminating the surface of the film, causing blocking, and deteriorating the adhesiveness, printability, vapor deposition, and the like. Further, in addition to the thermoplastic resin film using the surfactant, as a thermoplastic resin film having excellent antistatic properties, a resin having one or more specific functional groups in the thermoplastic resin, a special modified resin (Japanese Unexamined Patent Publication No. 62-12171
No. 7 and Japanese Patent Publication No. 1-29820) to form a film.

However, since none of the above resins is a polyolefin resin having an acrylate structure or an acrylamide structure, compatibility with a thermoplastic resin is poor, transparency is deteriorated, voids are generated, and surface properties are poor. There's a problem.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above prior art, and is intended to provide a thermoplastic resin film having not only excellent antistatic properties but also no bleeding or blocking. It is intended to provide.

[0007]

Means for Solving the Problems The present invention has the formula: - [CH ₂
—CH ₂ ] —65 to 99 mol% of an ethylene structural unit represented by the general formula:

[0008]

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(Wherein R ¹ represents an alkyl group having 1 to 4 carbon atoms) 0 to 15 mol% of an acrylate structural unit represented by the general formula:

[0010]

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Wherein R ² is an alkylene group having 2 to 8 carbon atoms, R ³ and R ⁴ are each an alkyl group having 1 to 4 carbon atoms, R ⁵ is an alkyl group having 1 to 12 carbon atoms, To 12 arylalkyl groups or alicyclic alkyl groups having 1 to 12 carbon atoms, X is a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅
0.3 The polyolefin resin having a weight average molecular weight from 1,000 to 50,000 were irregularly arranged linearly consisting of acrylamide structural units 1 to 35 mol% represented by showing a OSO ₃₎ to 50
The present invention relates to a thermoplastic resin film having antistatic properties, characterized in that it is contained by weight%.

[0012]

The thermoplastic resin film of the present invention has, as described above, 65 to 99 mol% of an ethylene structural unit represented by the formula:-[CH ₂ -CH ₂ ]-, a general formula:

[0013]

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(Wherein R ¹ represents an alkyl group having 1 to 4 carbon atoms) 0 to 15 mol% of an acrylate structural unit represented by the general formula:

[0015]

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Wherein R ² is an alkylene group having 2 to 8 carbon atoms, R ³ and R ⁴ are each an alkyl group having 1 to 4 carbon atoms, R ⁵ is an alkyl group having 1 to 12 carbon atoms, and 1 An arylalkyl group having 1 to 12 carbon atoms or an alicyclic alkyl group having 1 to 12 carbon atoms, X is a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅
0.3 The polyolefin resin having a weight average molecular weight from 1,000 to 50,000 were irregularly arranged linearly consisting of acrylamide structural units 1 to 35 mol% represented by showing a OSO ₃₎ to 50
% By weight.

The formula in the polyolefin-based resin:-[C
H ₂ -CH _2] - ratio of ethylene structural unit represented by is 65 to 99 mol%. The ratio of the ethylene structural units is 65
When the amount is less than mol%, the softening point of the polyolefin resin is lowered to cause tack or stickiness, and
If it exceeds 99 mol%, the antistatic property of the polyolefin resin becomes too small. In addition,
In the present invention, the proportion of the ethylene structural unit is particularly preferably from 85 to 97 mol% from the viewpoint of balancing the softening point and the antistatic property.

The general formula in the polyolefin resin is as follows:

[0019]

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The proportion of the acrylate structural unit represented by the formula (wherein R ¹ is as defined above) is from 0 to 15 mol%. When the proportion of the acrylate structural unit exceeds 15 mol%, the softening point of the polyolefin resin becomes low, and tack and stickiness occur. In the present invention, when the acrylate structural unit is contained, toughness and impact resistance are imparted, which is preferable.
In the present invention, the proportion of the acrylate structural unit is particularly preferably 1 to 15 mol%, particularly preferably 3 to 7 mol%, from the viewpoint of the balance between the softening point and toughness and impact resistance.

In the acrylate structural unit, R ¹
Is an alkyl group having 1 to 4 carbon atoms. Specific examples of such R ¹ include a methyl group, an ethyl group, an n-propyl group, i
-A propyl group, an n-butyl group and an i-butyl group, and these groups may be mixed in one molecule. Among these groups, a methyl group and an ethyl group are preferable for maintaining the softening point of the polyolefin resin.

The general formula in the polyolefin resin is as follows:

[0023]

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(Wherein R ² , R ³ , R ⁴ and R ⁵ are the same as above), and the proportion of the acrylamide structural unit is 1 to 35 mol%. When the proportion of the acrylamide structural unit is less than 1 mol%, the antistatic property becomes too small, and when it exceeds 35 mol%, the polyolefin resin becomes hygroscopic. In the present invention, the proportion of the acrylamide structural unit is determined in terms of the balance between the antistatic property and the hygroscopic property.
It is particularly preferred that the content is 3 to 15 mol%.

In the acrylamide structural unit, R
² is an alkylene group having 2 to 8 carbon atoms. Specific examples of such R ² include, for example, an ethylene group, a propylene group,
Hexamethylene group, neopentylene group and the like,
These groups may be mixed in one molecule. Among these groups, an ethylene group and a propylene group are preferable from the viewpoint of easiness of production and economy, and a propylene group is particularly preferable.

R ³ and R ⁴ each have 1 to 1 carbon atoms.
4 alkyl group. Specific examples of such R ³ and R ⁴ include a methyl group, an ethyl group, a propyl group, and a butyl group, and these groups may be present in one molecule. Of these groups, a methyl group and an ethyl group are preferred from the viewpoint of antistatic properties.

R ⁵ is an alkyl group having 1 to 12 carbon atoms, an arylalkyl group having 1 to 12 carbon atoms or an alicyclic alkyl group having 1 to 12 carbon atoms. Specific examples of such R ⁵ include:
For example, alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, n-octyl group, n-lauryl group and cyclohexyl group; benzyl group, 4-methyl An arylalkyl group such as a benzyl group; an alicyclic alkyl group such as a cyclohexyl group and a methylcyclohexyl group; these groups may be present in one molecule. R ⁵ is preferably a linear alkyl group or an arylalkyl group from the viewpoint of heat resistance, and is preferably a lower alkyl group from the viewpoint of antistatic properties. As particularly preferred R ^5, include the methyl and ethyl groups.

X is, for example, a halogen atom such as Cl, Br, I, CH ₃ OSO ₃ or C ₂ H ₅ OSO ₃
These may be mixed in one molecule. Among these, Cl and CH are preferred from the viewpoint of antistatic properties.
₃ OSO ₃ and C ₂ H ₅ OSO ₃ are preferred.

The polyolefin resin has a weight average molecular weight of 1,000 to 50,000. When the weight average molecular weight is less than 1000, the molecular weight becomes too small and volatilizes when heated, and when it exceeds 50,000, the viscosity when melted becomes too large and workability becomes poor. Become. The preferred weight average molecular weight is from 3,000 to 30,000.

In the present invention, the term "weight average molecular weight" refers to a monodisperse weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

Since the polyolefin resin used in the present invention is hardly soluble in ordinary gel permeation eluents such as tetrahydrofuran (THF) and xylene, its weight average molecular weight cannot be easily measured.
Ultra-high temperature GPC method (Kinukawa, Journal of Polymers, Vol. 44, No. 2, 1
39-141 (1987)).

An ethylene structural unit represented by the formula:-[CH ₂ -CH ₂ ]-, which is an intermediate of the polyolefin resin, a general formula:

[0033]

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(Wherein R ¹ is the same as defined above) and a general formula:

[0035]

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(Wherein, R ² , R ³ and R ⁴ are the same as described above). An olefin copolymer having a weight-average molecular weight of 1,000 to 50,000, which is linearly arranged and composed of acrylamide structural units, is represented by the following formula: For example, it can be obtained by the following method.

First, the raw material of the olefin copolymer is not particularly limited, but is more preferably ethylene (C ₂ H ₄ ) and a general formula: CH ₂ CHCOOR ¹ (wherein,
A (partial) hydrolyzate of a copolymer comprising an acrylate represented by the above formula (R ¹ is as defined above) is used. Such a copolymer can be easily obtained by copolymerizing ethylene and the acrylate by a high-pressure polymerization method.

The ratio of the ethylene structural unit derived from ethylene to the acrylate structural unit derived from the acrylate is determined by determining the ratio of the ethylene structural unit, the acrylate structural unit and the acrylamide structural unit of the obtained olefin copolymer. become.

Since the above-mentioned copolymer has a high molecular weight of usually about 5 to 300 in melt index, it has a low molecular weight by a decomposition method in which hydrolysis is carried out simultaneously with hydrolysis under high temperature and high pressure in the presence of water. It is preferred that the

At this time, the general formula derived from the acrylate:

[0041]

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[0042] (In the formula, R ¹ is as defined above) all or part of the acrylate structural unit represented by the hydrolysis formula:

[0043]

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An acrylic acid structural unit represented by the following formula:

In order to reduce the molecular weight of the copolymer by thermal decomposition to prepare a copolymer having a weight average molecular weight of 1,000 to 50,000, the copolymer is reacted at a reaction temperature of 150 to 500 in the presence of water. The molecule may be cut by heating at a temperature of 3 to 500 kg / cm ² at a temperature of 3 ° C.

In the present invention, the proportion of the acrylic acid structural unit can be appropriately adjusted by adjusting the amount of water charged, the reaction temperature, the pressure and the reaction time.

Specific examples of the above-mentioned degradation method include, for example, JP-A-53-57295, JP-A-53-65389, and JP-A-53-65389.
Methods described in JP-A-60-79008, JP-A-60-79015 and the like can be mentioned.

Since the polyolefin resin used in the present invention may impair the commercial value when colored, the raw material used in the present invention is disclosed in, for example, JP-A-60-79008. It is preferred to use the products of the exemplified process.

The polyolefin resin used in the present invention is obtained by using the thus obtained intermediate of the polyolefin resin.

The method for producing the polyolefin resin used in the present invention from the above intermediate is not particularly limited. An example will be described below.

The above intermediate is dissolved in an inert solvent such as an aromatic or aliphatic hydrocarbon such as benzene, toluene, xylene, cyclohexanone, decane, cumene, and cymene, and then added to the carboxyl group of the intermediate. 100 to 150 mol% of a dialkylamine-based monomer such as dialkylaminoalkylamine is added, and 130 to 22 mol% is added.
At 0 ° C., the carboxyl group contained in the acrylic acid structural unit is converted into a dialkylaminoalkylamide group to form an intermediate, which is then cationically modified with a known quaternizing agent such as an alkyl halide or dialkyl sulfate. By doing so, a polyolefin resin which is a linear random copolymer used in the present invention is obtained.

The polyolefin resin thus obtained has excellent antistatic properties. Although the reason for exhibiting such antistatic properties is not clear, the acrylamide structural unit contained in the polyolefin resin takes in moisture contained in the air,

[0053]

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It is considered that this is due to the fact that the material exhibits low electric resistance by being ionized and exhibiting electric conductivity.

Further, in the present invention, since the acrylamide structural unit does not exhibit volatility even at a high temperature and is chemically incorporated into the polyolefin resin used in the present invention, it is volatilized during processing. Therefore, it is considered that no blocking occurs after processing.

The thermoplastic resin film of the present invention contains the above-mentioned polyolefin resin.

The thermoplastic resin is, for example, polypropylene, ethylene-ethylene having an ethylene content of 2 to 30% by weight.
Propylene copolymer, terpolymer obtained by further copolymerizing butene-1 with the ethylene-propylene copolymer, high-pressure low-density polyethylene, linear low-density polyethylene, linear ultra-low-density polyethylene, high-density Polyethylene, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylate copolymer, ethylene- (meth) Polyolefin resins such as acrylic acid-maleic anhydride terpolymer, ethylene- (meth) acrylate-maleic anhydride terpolymer, polyester resins, polyamide resins, polystyrene resins, polycarbonate resins And ABS resins, and these resins are used alone or in combination of two or more.

The amount of the polyolefin resin used is 0.3 to 50% by weight, preferably 0.5 to 20% by weight, based on the total amount of the polyolefin resin and the thermoplastic resin.
It is. The amount of the polyolefin resin used is 0.3
When the content is less than 10% by weight, the molecular weight is larger than that of a known surfactant type antistatic agent, so that the proportion in the resin composition is small, and the surface resistance and the charge resistance are good although the blocking resistance is good. When the half-life of the polyolefin resin is reduced, that is, when it exceeds 50% by weight, the molecular weight of the polyolefin resin is smaller than that of the thermoplastic resin to be mixed. Although preferred, the resulting thermoplastic resin film has poor mechanical properties.

The method for producing the thermoplastic resin film of the present invention is not particularly limited, and various known film forming methods can be employed. Specific examples of the method for producing such a thermoplastic resin film include, for example, a casting method, an inflation method, a tubular method, and a tenter method.

Incidentally, the thermoplastic resin film of the present invention comprises:
Any of non-stretching, longitudinal uniaxial stretching and biaxial stretching may be used.

The thickness of the thermoplastic resin film is not particularly limited, and may be appropriately selected according to the intended use of the obtained thermoplastic resin film. Usually, the thickness of the film is 2 to 500 μm. .

In the present invention, inorganic fillers such as calcium carbonate, talc, glass monofilament, etc., antioxidants, flame retardants, coloring agents, polyfunctional monomers, etc. are used as long as the object of the present invention is not impaired. The various assistants described above may be contained in the thermoplastic resin film.

In the present invention, a known low molecular weight surfactant may be used in the polyolefin resin within a range not exceeding 30% by weight based on the polyolefin resin. When the surfactant is used within a range not exceeding 30% by weight, no bleeding from the obtained film is observed.

Further, the film of the present invention can be further subjected to a corona discharge treatment on at least one side thereof to increase the surface wetting tension and to improve the adhesiveness with various water-soluble coating agents. Further, a coating agent layer is provided, and various films, sheets, heat sealant layers and the like are laminated to form a composite, which can be used as various packaging materials and packaging materials. In addition, a metal film can be deposited on at least one surface of the film of the present invention, and further provided with a heat sealant layer, and used as various packaging materials and packaging materials.

Next, the thermoplastic resin film of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 85 mol% of an ethylene structural unit represented by the formula:-[CH ₂ -CH ₂ ]-

[0067]

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5 mol% of an acrylate structural unit represented by
And the formula:

[0069]

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The weight average molecular weight of linearly and irregularly composed of 10 mol% of acrylamide structural unit represented by the formula: 31
800 low-density polyethylene resin (density 0.930 g / cm ³ , melt index 3.7
g / 10 minutes) 20 parts were added to 100 parts and dry blended to obtain a resin composition for a film.

Next, the mixture was introduced into a T-die extruder set at a cylinder temperature of 180 to 200 ° C. and a die temperature of 200 to 210 ° C., melted, kneaded, extruded and passed through a cooling roll set at 20 ° C. An unstretched film having a length of 30 μm and a width of 1200 mm was formed.

When the surface specific resistance of the obtained film was examined according to the following method, it was found to be extremely small at 3.2 × 10 ¹¹ Ω, indicating that the film had excellent antistatic properties.

Next, the obtained films were overlaid,
After leaving in an atmosphere of 40 ° C. and 80% RH (relative humidity) for 7 days, the film was peeled off and the surface of the film was observed.
There was no stickiness due to bleed-out, and printing was performed on the obtained film surface using a printing ink for polypropylene, but there was no printing failure due to bleed-out.

Next, one surface of the obtained film was subjected to a corona discharge treatment so that the surface wetting tension was 37 dyne / cm or more.
Adhesion with various coating agents could be improved.

Further, a coating agent layer is provided, and is bonded to other films, sheets, foams, metal foils, and papers.
Alternatively, a heat sealant layer was provided and applied to various packaging materials and packaging materials. In addition, a metal film was deposited on one surface of the film of the present invention, and a heat sealant layer was further provided to apply the film to various packaging materials and packaging materials.

(Surface specific resistance) A film is cut into a size of 10 cm × 10 cm, and left for aging in a constant temperature and constant temperature room controlled at 20 ° C. and 60% RH (relative humidity) for 48 hours.

After the aging, the surface resistivity is measured in the atmosphere.

Measuring device: Super insulation meter (VE-40 type) manufactured by Kawaguchi Electric Works, Ltd. connected to a room temperature measuring box (RC-02 type) Measurement condition: Applied voltage 100 V Value measured with this device Is adopted.

The above surface resistivity is 1 × 10 ¹³ Ω.
Hereinafter, those having a charge half life of 3 minutes or less are considered to have antistatic properties.

Example 2 85 parts (parts by weight, hereinafter the same) of a high-pressure method low-density polyethylene (density: 0.92 g / cm ³ , melt index: 5.6 g / 10 minutes, particle size: 32 mesh pass) and a formula:- [CH ₂ -C
H _2] - ethylene structural units 85 mole% represented by the formula:

[0081]

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5 mol% of an acrylate structural unit represented by the formula:

[0083]

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A linearly and irregularly arranged weight average molecular weight of 35 mol% of acrylamide structural unit represented by the following formula: 35
Then, 15 parts of a polyolefin-based resin was added and dry blended to obtain an unstretched film in the same manner as in Example 1.
This film had a thickness of 40 μm.

Next, as the physical properties of the obtained film, the surface resistivity was determined in the same manner as in Example 1, and the half-life of the charge
Bleed-out and blocking shear were determined according to the following methods. Table 1 shows the results.

(Half-Life of Electric Charge) A 10 KV voltage was applied to the sample using a static honest meter (manufactured by Shishido Shokai Co., Ltd.) in the same atmosphere as when the surface resistivity was measured, and the applied electric charge was measured. Determine the decay rate as the half-life.

(Bleed-out) Laminate the film,
After being put in an atmosphere of 80 ° C. and 80% RH for 7 days, the film is taken out and peeled off, and the presence or absence of the deposit on the film surface is examined.

(Blocking shear force) Two films were superimposed over a width of 3 cm and a length of 4 cm.
g of the film and placed in an atmosphere of 40 ° C. and 80% RH for 7 days, and the shear peeling force of the two films is determined by a Shopper type tensile tester.

A shear peeling force of 1,000 g or less is considered to be acceptable. The weight is preferably 500 g or less.

Example 3 80 parts of a low-pressure method high-density polyethylene (density: 0.955 g / cm ³ , melt index: 7.3 g / 10 min) and the formula:-[C
H ₂ —CH ₂ ] —80 mol% of an ethylene structural unit represented by the formula:

[0091]

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Using 20 parts by weight of a polyolefin resin having a polymerization degree of 490, which is linearly and randomly arranged and composed of 20 mol% of an acrylamide structural unit represented by the following formula, the mixture was introduced into an extruder equipped with an inflation film forming apparatus. Melting by heating to ℃
The mixture was kneaded to form an unstretched film through a mantrel-type die, and at the same time, air was blown into the film to simultaneously cool and impart biaxial orientation to obtain a biaxially stretched film.

This film had a total thickness of 15 μm.

The physical properties of the obtained film were examined in the same manner as in Example 2. Table 1 shows the results.

Example 4 88 parts of linear low-density polyethylene (density: 0.935 g / cm ³ , melt index: 8.5 g / 10 minutes) and the formula:-[C
H ₂ —CH ₂ ] —80 mol% of an ethylene structural unit represented by the formula:

[0096]

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1 mol% of an acrylate structural unit represented by the formula:

[0098]

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A linearly and irregularly arranged weight average molecular weight of 27 mol% of acrylamide structural unit represented by the following formula:
A biaxially stretched film was obtained in the same manner as in Example 3 except that 12 parts of a polyolefin resin of 000 was used. This film had a thickness of 20 μm.

The physical properties of the obtained film were examined in the same manner as in Example 2. Table 1 shows the results.

Example 5 Polypropylene (melt index: 2.5 g / 10 minutes)
98 parts and 88 mol% of an ethylene structural unit represented by the formula:-[CH ₂ -CH ₂ ]-;

[0102]

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3 mol% of an acrylate structural unit represented by the formula:

[0104]

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A linearly and irregularly arranged weight average molecular weight of 9 mol% of an acrylamide structural unit represented by the formula: 33
2,000 polyolefin resin and introduced into an extruder equipped with a simultaneous biaxial stretching apparatus with a tenter method at 210-230 ° C.
The mixture was extruded from a T-die die onto a cooling roll controlled at 20 ° C to form an unstretched film, and then continuously stretched again at 150 to 160 ° C using a tenter to stretch it in a longitudinal stretching ratio of 5 to 9 times. A biaxially stretched film was obtained by simultaneously biaxially stretching and orienting the film at a transverse stretching ratio of 3 to 4 times. The obtained film had a thickness of 12 μm.

The physical properties of the obtained film were examined in the same manner as in Example 2. Table 1 shows the results.

Example 6 85 parts of nylon-6 (manufactured by Toray Industries, Inc., CM1021T, particle size: 32 mesh pass), and 85 mol% of an ethylene structural unit represented by the formula:-[CH ₂ -CH ₂ ]- formula:

[0108]

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5 mol% of an acrylate structural unit represented by the following formula:

[0110]

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A linearly and irregularly arranged weight average molecular weight of 35 mol% of acrylamide structural unit represented by the following formula:
Then, 15 parts of a polyolefin resin of 000 were added and dry blended.

Next, an unstretched film was obtained in the same manner as in Example 1 except that the cylinder temperature was set at 230 to 250 ° C. and the die temperature was set at 250 to 260 ° C. This film is 30μm thick
It was.

Next, as the physical properties of the obtained film, the surface resistivity was determined in the same manner as in Example 1, and the half-life of the charge,
Bleed-out and blocking shear were examined as in Example 2. Table 1 shows the results.

Example 7 80 parts of polyethylene terephthalate (manufactured by Toray Industries, Inc., T type, intrinsic viscosity: 0.598, particle size: 32 mesh pass) and an ethylene structure represented by the formula:-[CH ₂ -CH ₂ ]- Unit 80 mol% and formula:

[0115]

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Using 20 parts by weight of a polyolefin resin having a degree of polymerization of 490, which is linearly and irregularly composed of 20 mol% of an acrylamide structural unit represented by the following formula, and introduced into an extruder equipped with an inflation film forming apparatus, 260 to 280 Melting by heating to ℃
The mixture was kneaded to obtain an unstretched film through a mantrel-type die, and at the same time, air was blown into the film to simultaneously cool and impart biaxial orientation to obtain a biaxially stretched film.

This film had a total thickness of 15 μm.

The physical properties of the obtained film were examined in the same manner as in Example 2. Table 1 shows the results.

[0119]

[Table 1]

Comparative Example 1 A resin composition for a film was prepared by mixing 99 parts of a high-pressure low-density polyethylene (density 0.923 g / cm ³ , melt index: 5.6 g / 10 min) and 1 part of stearic acid monoglyceride as an antistatic agent. I got it.

Next, a film was obtained in the same manner as in Example 2 using the obtained resin composition for a film.

The physical properties of the obtained film were examined in the same manner as in Example 2. Table 2 shows the results.

Comparative Example 2 99.7 parts of a low-pressure method high-density polyethylene (density: 0.955 g / cm ³ , melt index: 7.3 g / 10 min) and the following formula as an antistatic agent:

[0124]

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Betaine-type amphoteric surfactant represented by the formula:
Three parts were mixed to obtain a resin composition for a film.

Next, a film was obtained in the same manner as in Example 2 using the obtained resin composition for a film.

The physical properties of the obtained film were examined in the same manner as in Example 2. Table 2 shows the results.

Comparative Example 3 98.5 parts of linear low-density polyethylene (density 0.935 g / cm ³ , melt index: 8.5 g / 10 min) and monoglyceride stearate as an antistatic agent and a compound represented by the following formula:

[0129]

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A betaine-type amphoteric surfactant represented by the following formula:
A resin composition for a film was obtained by mixing 0.5 part of the mixture at a weight ratio of 15:85.

Using the obtained resin composition for a film, a film was obtained in the same manner as in Example 4.

The physical properties of the obtained film were examined in the same manner as in Example 2. Table 2 shows the results.

Comparative Example 4 98.5 parts of an ethylene-propylene copolymer having an ethylene content of 3% by weight (melt index: 4.3 g / 10 minutes) and 30:70 by weight of sodium dodecylbenzenesulfonate and polyethylene glycol as antistatic agents Mixed with
1.5 parts were mixed to obtain a resin composition for a film.

Next, a biaxially stretched film was obtained from the obtained resin composition for a film in the same manner as in Example 5.

The physical properties of the obtained film were examined in the same manner as in Example 2. Table 2 shows the results.

Comparative Example 5 Polypropylene (Melt Index: 2.5 g / 10 min)
99.5 parts and stearyldiethanolamine 0.5 part as an antistatic agent were mixed to obtain a resin composition for a film.

Next, a film was obtained in the same manner as in Example 5 using the obtained resin composition for a film.

The physical properties of the obtained film were examined in the same manner as in Example 2. Table 2 shows the results.

[0139]

[Table 2]

From the results shown in Table 1, the thermoplastic resin film of the present invention is excellent in that the surface resistivity, which is an index of antistatic property, is 1 × 10 ¹³ Ω or less and the half-life of electric charge is 180 seconds or less. This shows that the film has no bleed-out of the antistatic component and thus has excellent antistatic properties without blocking.

On the other hand, the films obtained in Comparative Examples 1 to 5 used a conventional comparatively low molecular weight surfactant type antistatic agent. Is satisfied, it can be seen that the antistatic agent bleeds out of the film, so that there is a disadvantage that blocking occurs.

From the above, the thermoplastic resin film of the present invention is excellent in antistatic properties, and has no bleed out of an antistatic agent and does not cause blocking.
For example, it can be seen that the present invention can be suitably used in a field in which occurrence of a trouble due to static electricity must be prevented.

[0143]

The thermoplastic resin film of the present invention exhibits extremely excellent antistatic properties without bleed-out, does not adhere to dust, and does not give a shock to the human body due to electrostatic discharge. It is a film with excellent properties.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location // C08L 23:04

Claims (1)

(57) [Claims] 1. An ethylene structural unit represented by the formula:-[CH ₂ -CH ₂ ]-65 to 99 mol%, a general formula: (Wherein R ¹ represents an alkyl group having 1 to 4 carbon atoms) and 0 to 15 mol% of an acrylate structural unit represented by the following general formula: (Wherein, R ² is an alkylene group having 2 to 8 carbon atoms, R ³ and R ⁴ are alkyl groups having 1 to 4 carbon atoms, R ⁵ is an alkyl group having 1 to 12 carbon atoms, and 1 to 12 carbon atoms. An arylalkyl group or an alicyclic alkyl group having 1 to 12 carbon atoms, X represents a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅ OSO ₃ ) 1 to 35 mol% of an acrylamide structural unit
Weight average molecular weight 1000 ~
A thermoplastic resin film having an antistatic property, comprising 0.3 to 50% by weight of 50,000 polyolefin resin.