JP2001214013A - Resin drawn film and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a white opaque resin oriented film having excellent printability, shrinkage characteristics and rigidity free from a fear of causing environment pollution. SOLUTION: This resin oriented film comprises a uniaxial oriented film composed of 30-79 wt.% of a propylene-based polymer (A), 3-25 w.% of polybutene-1 (B), 3-25 wt.% of a petroleum resin (C) and/or a hydrogenated terpene resin (D) and 10-65 wt.% of an organic and/or inorganic fine filler powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an opaque stretched resin film having excellent heat shrinkage properties, printability and rigidity, and a method for producing the same. The stretched resin film of the present invention is useful for labeling and packaging various containers such as dry batteries, beverage can containers, and beverage bottle containers.

[0002]

2. Description of the Related Art Conventionally, printed heat-shrinkable films of vinyl chloride are often used for decoration / packaging of dry batteries, beverage cans, beverage bottles, and the like. However, vinyl chloride has a problem that toxic gas such as hydrogen chloride gas is generated at the time of incineration to cause environmental pollution. In order to avoid such environmental pollution, research and development of materials using polyolefin resins have been actively conducted recently. However, a material using a polyolefin resin has a disadvantage that heat shrinkage properties are poor due to crystallinity.

In order to improve this disadvantage, a method of mixing an amorphous resin (JP-A-60-135233, JP-A-60-171150, JP-A-07-11931)
No. 7) have been proposed. However, films produced by these methods have problems in that they are not rigid and cause color misregistration during printing and poor adhesion of ink. Further, there is also a disadvantage that productivity is low due to poor heat shrinkage properties, and the film shrinks during storage.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve these problems of the prior art. That is, an object of the present invention is to provide a white, opaque resin stretched film which is excellent in printability, shrinkage characteristics, and rigidity and does not cause environmental pollution. Another object of the present invention is to provide a method for easily producing a resin stretched film having such excellent characteristics.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above problems, and as a result, a resin stretched film obtained by blending a plurality of selected thermoplastic resins in an appropriate amount and uniaxially stretching is obtained. The inventors have found that they have excellent characteristics meeting the purpose of the present invention, and have completed the present invention.

That is, the present invention relates to a propylene polymer (A) of 30 to 79% by weight, and a polybutene-1 (B) of 3 to 2%.
1 containing 5% by weight, 3 to 25% by weight of petroleum resin (C) and / or hydrogenated terpene resin (D), 10 to 65% by weight of fine organic and / or inorganic powder (E)
A resin-stretched film comprising an axially-stretched film; and 45 to 85% by weight of a propylene-based polymer (A), 5 to 30% by weight of a polybutene-1 (B), a petroleum resin (C) and / or a hydrogenated terpene resin ( D) 5-30% by weight,
On at least one surface of the uniaxially stretched film substrate layer (A) containing 5 to 45% by weight of an organic and / or inorganic fine powder (E), 30 to 79% by weight of a propylene-based polymer (A) and polybutene-1 (B) 3-25% by weight of petroleum resin (C) and / or hydrogenated terpene resin (D)
An object of the present invention is to provide a stretched resin film having a uniaxially stretched film surface layer (B) containing 3 to 25% by weight and 10 to 65% by weight of an organic and / or inorganic fine powder (E).

The propylene-based polymer (A) used in the stretched resin film of the present invention is a random copolymer (a) containing 2 to 10% by weight of ethylene and 90 to 98% by weight of propylene.
1) random copolymer of ethylene 0 to 5% by weight, butene-18 8 to 30% by weight, and propylene 92 to 65% by weight (a2); ethylene 0 to 5% by weight, propylene 9
It is preferably a random copolymer (a3) of 8.5 to 65% by weight and butene-10 to 30% by weight; or a propylene homopolymer (a4), and a petroleum resin (C)
Is a polymer (c1) obtained by cationic polymerization of a polymerizable composition containing a chain olefin having 5 carbon atoms; a polymer (c2) obtained by thermally polymerizing a polymerizable composition containing dicyclopentadiene; an aromatic compound having 9 carbon atoms A polymer (c3) obtained by cationic polymerization of a polymerizable composition containing an olefin; a copolymer (c4) obtained by cationic polymerization of a polymerizable composition containing a chain olefin having 5 carbon atoms and an aromatic olefin having 9 carbon atoms; or , The (c1)
(C2) a polymer obtained by hydrogenating (c3) or (c4), or (c1), (c2), (c3) or (c).
It is preferable that the modified polymer (c5) is obtained by introducing a carboxylic acid group, a maleic anhydride group and / or a hydroxyl group into 4).

The dimensional heat shrinkage in the stretching direction of the stretched resin film of the present invention is 25% or more at 100 ° C.
It is preferably at most 1% at 0 ° C. The Clark stiffness in the stretching direction is preferably in the range of 10 to 300. Further, the total thickness of the stretched resin film of the present invention is in the range of 30 to 250 μm, and the thickness of the base material layer (a) is preferably 50 to 98% of the total thickness.
Further, the opacity of the stretched resin film is preferably 20% or more, and it is preferable that the back surface has a pressure-sensitive adhesive function.

The present invention relates to a propylene polymer (A) 30
To 79% by weight, 3 to 25% by weight of polybutene-1 (B),
Uniaxially stretching a resin composition containing 3 to 25% by weight of petroleum resin (C) and / or hydrogenated terpene resin (D) and 10 to 65% by weight of organic and / or inorganic fine powder (E) A method for producing a stretched resin film comprising: Further, the propylene-based polymer (A) 45 to 85
5 to 30% by weight of polybutene-1 (B), 5 to 30% by weight of petroleum resin (C) and / or hydrogenated terpene resin (D), 5 to 30% of inorganic and / or organic fine powder (E) On at least one side of the base layer (A) of the resin composition containing 45% by weight, 30 to 79% by weight of a propylene-based polymer (A) and 3 to 2 of polybutene-1 (B)
Surface of resin composition containing 5% by weight, petroleum resin (C) and / or hydrogenated terpene resin (D) 3 to 25% by weight, organic or / and inorganic fine powder (E) 10 to 65% by weight The present invention also provides a method for producing a stretched resin film, comprising a step of forming a layer (b) and uniaxially stretching the formed laminate.

The stretching temperature of the uniaxial stretching in the production method of the present invention is in the range of 65 to 150 ° C., and the stretching ratio is 1.5.
It is preferably up to 11 times. Also, after uniaxial stretching,
The heat treatment is preferably performed within a range from the stretching temperature to a temperature higher by 30 ° C. than the stretching temperature. Further, it is preferable that the uniaxial stretching is performed by stretching the object using a difference in peripheral speed of the roll group, or it is preferable to stretch the object by holding the object between clips in a hot oven.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a stretched resin film of the present invention and a method for producing the same will be described in detail. The stretched resin film of the present invention comprises 30 to 79% by weight of a propylene polymer (A) and polybutene-1 (B).
Uniaxial stretching containing 3 to 25% by weight, petroleum resin (C) and / or hydrogenated terpene resin (D) 3 to 25% by weight, organic and / or inorganic fine powder (E) 10 to 65% by weight It is a stretched resin film made of a film. The uniaxially stretched film can be used as a surface layer (b) by being laminated on various base material layers. The type of the layer used as the base material layer can be appropriately determined according to the intended use. Among them, 45 to 85% by weight of the propylene-based polymer (A), 5 to 30% by weight of the polybutene-1 (B), and petroleum resin (C) and / or hydrogenated terpene resin (D)
The resin stretched film of the present invention laminated on a uniaxially stretched film base layer (a) containing 5 to 30% by weight and 5 to 45% by weight of an organic and / or inorganic fine powder (E) is particularly preferred. The stretched resin film of the present invention having such a base material layer (a) and a surface layer (b) may be any other film as long as the film contains a structural unit in which the surface layer (b) is laminated on the base material layer (a). The configuration is not particularly limited. Further, this structural unit may have a simple structure in which a surface layer (b) is laminated on one surface of the base material layer (a), or a surface layer (b) is laminated on both surfaces of the base material layer (a). It may be a structure. The base material layer (a) and the surface layer (b) are each composed of a propylene-based polymer (A), polybutene-1 (B), and a petroleum resin (C).
And / or a hydrogenated terpene resin (D), and an inorganic and / or organic fine powder (E).

The propylene polymer (A) used in the base layer (a) and the surface layer (b) is not particularly limited as long as it is a polymer using propylene as a monomer. It may be a propylene homopolymer obtained by homopolymerizing only propylene or a propylene copolymer obtained by copolymerizing propylene with another polymerizable monomer. Preferred propylene-based polymer (A) is a polymer obtained by polymerizing propylene as a monomer in an amount of 50% by weight or more, more preferably 60% by weight or more, and still more preferably 65% or more.

Specifically, a random copolymer (a) of 2 to 10% by weight of ethylene and 90 to 98% by weight of propylene is used.
1) random copolymer of ethylene 0 to 5% by weight, butene-18 8 to 30% by weight, and propylene 92 to 65% by weight (a2); ethylene 0 to 5% by weight, propylene 9
8.5 to 65% by weight and butene-10 to 30% by weight of a random copolymer (a3); and a propylene homopolymer (a4). Particularly preferred is
It is a propylene homopolymer (a4). In addition, in this specification, "~" means the range including the numerical value described before and after. The melt flow rate (230 ° C., 2.16 kg load) of the propylene polymer (A) is 0.5 to
It is preferably within the range of 30 g / 10 minutes.

The polymerization form of polybutene-1 (B) used for the base material layer (a) and the surface layer (b) is not particularly limited. For example, crystalline homopolybutene-1 can be mentioned as one typical example. In addition, crystalline polybutene-
As far as 1, it may be a copolymer with a small amount (for example, 20% by weight or less) of a comonomer. Examples of such a comonomer include ethylene, propylene, and pentene-1. Polybutene-1
The melt flow rate of (B) is preferably 1 g / 10 minutes or more.

The petroleum resin (C) used for the base material layer (a) and the surface layer (b) is a resin directly using a petroleum unsaturated hydrocarbon as a raw material. For example, those using cyclopentadiene as a main raw material and alkylstyrene indene resins using a higher olefinic hydrocarbon as a main raw material can be exemplified. As a preferable petroleum resin (C), a polymer (c1) obtained by cationic polymerization of a polymerizable composition containing a chain olefin having 5 carbon atoms; a polymer (c2) obtained by thermally polymerizing a polymerizable composition containing dicyclopentadiene; Polymer (c3) obtained by cationically polymerizing a polymerizable composition containing an aromatic olefin having 9 carbon atoms; copolymer obtained by cationically polymerizing a polymerizable composition containing a chain olefin having 5 carbon atoms and an aromatic olefin having 9 carbon atoms Merged (c4); a polymer obtained by hydrogenating (c1), (c2), (c3) or (c4), or (c1)
(C2) A modified polymer (c5) in which a carboxylic acid group, a maleic anhydride group and / or a hydroxyl group are introduced into (c3) or (c4) can be exemplified.

The "polymerizable composition" in the definition of (c1) to (c4) contains the polymerizable monomer described before, and includes the polymerizable monomer described before. A monomer other than the above may or may not be contained. The content of monomers other than the polymerizable monomers described above is preferably 30% by weight or less, and preferably 10% by weight or less.
The content is more preferably not more than 5% by weight, still more preferably not more than 5% by weight, and particularly preferably not more than 1% by weight.

The chain olefin having 5 carbon atoms used in the production of (c1) and (c4) includes 1-pentene,
Examples thereof include 2-pentene, 3-pentene, pentadiene, isobutene, and isobutadiene. (C
The position of the double bond is not particularly limited as long as dicyclopentadiene used in the production of 2) is a dimer of cyclopentadiene. The aromatic olefin having 9 carbon atoms used in the production of (c3) and (c4) is a compound having 9 total carbon atoms having an aromatic ring and a group having a polymerizable double bond bonded to the aromatic ring. For example, o-methylstyrene, m
-Methylstyrene, p-methylstyrene, 1-phenylpropene, 2-phenylpropene, 3-phenylpropene and the like can be exemplified. One of these materials may be selected and used alone, or two or more may be selected and used in combination. Preferred are fractions or fractions obtained during petroleum refining.

The cationic polymerization of (c1), (c3) and (c4), the thermal polymerization of (c2), the hydrogenation of (c5) and the carboxylic acid group, maleic anhydride group and hydroxyl group introduction reaction of (c5) Can be performed by employing known conditions. Any conditions can be employed in the present invention as long as the desired polymer can be obtained and the desired functional group can be introduced. As the petroleum resin (C), among the above, from the viewpoint of hue and heat resistance, 100
It is preferable to use a hydrogenated polymer (c5) having a softening temperature of at least ° C.

The type of the hydrogenated terpene resin (D) used in the stretched resin film of the present invention is not particularly limited. The hydrogenation conditions and the hydrogenation rate are not particularly limited.
Representative examples of the terpene resin (D) include "Clearon" (trade name, manufactured by Yasuhara Chemical Co., Ltd.).

The type of the organic and / or inorganic fine powder (E) used in the stretched resin film of the present invention is not particularly limited. Examples of the organic fine powder include polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene terephthalate, polystyrene, melamine resin, polyethylene sulphite, polyimide, polyethyl ether ketone, polyphenylene sulphite and the like. Among them, it is preferable to use an organic fine powder having a melting point higher than that of the resin composition used and incompatible with the resin composition from the viewpoint of void formation.

Examples of the inorganic fine powder include heavy calcium carbonate, light calcium carbonate, calcined clay, talc, titanium oxide, barium sulfate, zinc oxide, magnesium oxide, diatomaceous earth, and silicon oxide. Above all, heavy calcium carbonate, calcined clay, titanium oxide, and diatomaceous earth are used, which are inexpensive, have good void formation during stretching, and are preferable for opacity.

The particle size of the organic and / or inorganic fine powder (E) is not particularly limited, but the average particle size is 0.6 to 3
μm is preferred. In particular, it is preferable to adjust the average particle diameter of the fine powder used for the base layer (a) so that the average particle diameter of the fine powder used for the surface layer (ii) is smaller. By adopting such an aspect, surface projections are reduced, and the printing becomes smoother and higher definition printing becomes possible. Further, it is preferable that the content of coarse particles having a particle diameter of 44 μm or more, which causes surface projections, is set to 10 ppm or less.

Each of the above components (A) to (E) used in the base material layer (a) and the surface layer (b) may be used alone by selecting one kind alone or two or more kinds. May be selected and used in combination. When two or more kinds are used in combination, they may be mixed in advance and used. Also,
The material used for the base material layer (a) and the material used for the surface layer (b) may be the same or different. Also,
The base material layer (a) and the surface layer (b) may each contain only one of the petroleum resin (C) and the hydrogenated terpene resin (D), or may contain both. You may. Preferred is a mode in which only one of them is included.

The base material layer (a) is composed of 45 to 85% by weight of the propylene polymer (A) and 5 to 3% of polybutene-1 (B).
A resin composition containing 0% by weight, 5 to 30% by weight of a petroleum resin (C) and / or a hydrogenated terpene resin (D), and 5 to 45% by weight of an organic and / or inorganic fine powder (E); It is formed by axial stretching. The surface layer (b) is composed of 30 to 79% by weight of a propylene polymer (A), 3 to 25% by weight of a polybutene-1 (B), a petroleum resin (C) and / or a hydrogenated terpene resin (D).
It is formed by uniaxially stretching a resin composition containing 3 to 25% by weight and 10 to 65% by weight of an organic and / or inorganic fine powder (E).

The propylene-based polymer (A) in the base material layer (a) contributes to the strength and heat resistance of the stretched resin film, so the blending amount is 45% by weight or more. If it exceeds 85% by weight, low-temperature stretching for obtaining high shrinkage becomes difficult.
Polybutene-1 (B) is a propylene-based polymer (A),
It acts to promote compatibilization of petroleum resin (C) or hydrogenated terpene resin (D), organic and / or inorganic fine powder (E), and facilitates low-temperature stretching, Contributes to improvement in flexibility and tear resistance. It also contributes to improvement in heat shrinkability. If the amount of polybutene-1 (B) is less than 5% by weight, the propylene-based polymer (A), petroleum resin (C) or hydrogenated terpene resin (D), organic and / or inorganic fine powder (E) ) Is poor in compatibility, and stretching becomes difficult. If it exceeds 30% by weight, the stiffness of the film decreases,
High-speed labeling with an automatic labeler cannot be performed as an adhesive label.

The petroleum resin (C) and the hydrogenated terpene resin (D) have a function of improving the heat shrinkage characteristics and rigidity of the obtained film. Further, it has a function of lowering the apparent melting point and improving stretchability at low temperatures. If the total amount of the petroleum resin (C) and the hydrogenated terpene resin (D) is less than 5% by weight, high heat shrinkage properties and rigidity cannot be obtained, and the effect of improving the low-temperature stretchability is deteriorated. 30% by weight
Exceeding the heat resistance of the film decreases. Further, the tear resistance becomes worse, and the film is easily torn along the stretching direction.

Organic and / or inorganic fine powder (E)
Contributes to the opacity of the obtained stretched resin film.
If the amount is less than 5% by weight, an opaque film cannot be obtained. On the other hand, if the amount exceeds 45% by weight, high opacity can be obtained, but uniform stretching cannot be performed, and many stretching breaks occur.

The propylene-based polymer (A) in the surface layer (b) contributes to improving the surface strength and smoothness of the film. If the amount of the propylene-based polymer (A) is less than 30%, good gloss and surface strength (hardness) of the film cannot be obtained. If the amount exceeds 79% by weight, high adhesion to the printing ink cannot be obtained. Polybutene-1
(B) is a propylene-based polymer (A), a petroleum resin (C) and / or a hydrogenated terpene resin (D), an organic and / or inorganic fine powder, as in the case of using the base layer (a). (E) acts as a compatibilizer. In addition to improving the low-temperature stretchability, it also contributes to improving the flexibility and tear resistance of the film and preventing the film from blocking. If the blending amount of polybutene-1 (B) is less than 3% by weight, the flexibility and tear resistance of the film decrease.
On the other hand, if it exceeds 25% by weight, the surface hardness of the film decreases, and the film surface is easily scratched.

The petroleum resin (C) and the hydrogenated terpene resin (D) improve the printability, glossiness, rigidity and the like of the obtained film. If the total amount of the petroleum resin (C) and the hydrogenated terpene resin (D) is less than 3% by weight, the rigidity of the film is not good. If the content exceeds 25% by weight, blocking occurs in the film.

The organic and / or inorganic fine powder (E) contributes to opacity of the film, printability (adhesion of ink), and prevention of blocking. When the amount of the organic and / or inorganic fine powder (E) is less than 10% by weight, opacity is obtained;
A decrease in ink adhesion is observed. In addition, the addition amount is 65
If the amount exceeds the weight percentage, cracks or tears occur in the stretched film.

The resin composition for forming the base layer (a) and the resin composition for forming the surface layer (b) include the above (A) to
In addition to (E), if necessary, a heat stabilizer, an ultraviolet stabilizer, an antioxidant, an antistatic agent, an antiblocking agent, a nucleating agent, a lubricant and the like may be added. These are preferably blended at a ratio of 3% by weight or less.

The thickness of each layer of the stretched resin film to be produced is preferably adjusted so that the thickness of the base material layer (a) is 50 to 98% of the total thickness. By setting the thickness of the base material layer (a) within this range, the stretchability is stabilized,
A resin stretched film having good rigidity and printability can be obtained. If the thickness of the base material layer is less than 50% of the total thickness, the suitability for stretching at low temperatures and the shrinkage during storage at low temperatures tend to be poor. The total thickness of the stretched resin film of the present invention is 30 to 250.
It is preferably within the range of μm. Further, the opacity of the stretched resin film of the present invention is preferably 20% or more, and more preferably less than 40%. When the opacity is less than 20%, there is a tendency that sufficient opacity cannot be obtained.

The stretched resin film of the present invention can be produced by combining various methods known to those skilled in the art. The stretched resin film produced by any method is included in the scope of the present invention as long as it satisfies the conditions described in claim 1.

Each layer constituting the stretched resin film of the present invention comprises the above-mentioned polypropylene polymer (A), polybutene-1 (B), petroleum resin (C) and hydrogenated terpene resin (D) at a predetermined ratio. And extruding. Thereafter, by performing lamination and uniaxial stretching, the resin stretched film of the present invention can be manufactured.

When the stretched resin film of the present invention has a multilayer structure, it may be produced by separately stretching the substrate layer (a) and the surface layer (b) and then laminating the layers. It may be manufactured by laminating a) and a surface layer (b) and then stretching them together. These methods can be appropriately combined.

A preferred production method includes a step of laminating the base material layer (a) and the surface layer (b) and then stretching them together. That is, the propylene-based polymer (A) 45-
85% by weight, polybutene-1 (B) 5-30% by weight, petroleum resin (C) and / or hydrogenated terpene resin (D) 5-30% by weight, organic and / or inorganic fine powder (E) 5 Propylene-based polymer (A) 30 to 79% by weight, polybutene-1 (B) 3 to 2 on at least one surface of the base material layer (A) of the resin composition containing 0.1 to 45% by weight.
Surface of resin composition containing 5% by weight, petroleum resin (C) and / or hydrogenated terpene resin (D) 3 to 25% by weight, organic and / or inorganic fine powder (E) 10 to 65% by weight It is preferable to use a method for producing a stretched resin film including a step of forming a layer (b) and uniaxially stretching the formed laminate. ADVANTAGE OF THE INVENTION According to the manufacturing method of this invention, it is simple and the manufacturing cost becomes low compared with the case of extending | stretching separately and laminating.

For stretching, various known methods can be used. The stretching temperature is preferably set to be equal to or lower than the melting point of the crystalline resin (polypropylene polymer, polybutene-1) used and equal to or higher than the glass transition temperature of the non-crystalline resin (petroleum resin, hydrogenated terpene resin). . Specifically, it is preferable to carry out in the range of 65 to 150 ° C. Further, in order to obtain high heat shrinkability, it is preferable to stretch at a low temperature. In particular, the temperature is preferably lower than the melting point of the propylene-based polymer (A) used in the base layer (a) by at least 15 ° C.

Specific examples of the stretching method include inter-roll stretching using a difference in peripheral speed between roll groups, and clip stretching using a tenter oven. Among them, uniaxial stretching between rolls is preferable because it is easy to adjust the stretching ratio to obtain a stretched film having an arbitrary shrinkage ratio.

The stretching ratio is not particularly limited.
It is appropriately determined in consideration of the purpose of use of the stretched resin film of the present invention and the characteristics of the resin used. Usually, it is stretched within a range of 1.5 to 11 times. Above all, it is more preferable that the film is stretched 1.5 to 7 times in the inter-roll stretching utilizing the peripheral speed difference of the rolls, and 5 to 11 times in the case of clip stretching performed in a hot oven. When, for example, a polypropylene homopolymer and polybutene-1 and a petroleum resin or a hydrogenated terpene resin are used, the stretching ratio is particularly preferably 2 to 7 times.

After the stretching, heat treatment is preferably performed. The temperature of the heat treatment is 30 ° C. from the stretching temperature to the stretching temperature.
It is preferred to select within a high temperature range. By performing the heat treatment, shrinkage during storage of the product can be reduced, so that tight winding of the film during long-term storage can be prevented. The heat treatment is generally performed using a roll and a hot oven, but may be performed in combination. In addition, it is desirable to perform a corona treatment or a plasma treatment on the surface as necessary, because there is an advantage that the adhesion of the printing ink is improved.

The stretched resin film of the present invention is useful as a heat-shrinkable film. That is, since the heat shrinkage is low at a low temperature and the heat shrinkage is high at a high temperature, the resin stretched film of the present invention can be easily heat shrunk by heating and applied to a wide range of products. For example, by appropriately adjusting the type and amount of the material constituting the stretched resin film of the present invention, the dimensional heat shrinkage in the stretching direction is preferably 1% or less at 50 ° C and 25% or more at 100 ° C. Especially, the heat shrinkage at 100 ° C. is 2
When the content is 5% or more, the heat shrinkability of the shrink label is sufficient, so that the appearance can be improved. Also,
When the heat shrinkage at 50 ° C. is 1% or less, the film can be printed well because the film does not tighten during storage.

The stretched resin film of the present invention has a high Clark stiffness in the stretching direction. Especially Clark stiffness is 10-300
Is preferably in the range. When the Clarke stiffness is 10 or less, the label itself tends to drop or fall out of a desired position due to low self-sustainability of the label itself peeled from the release paper when the label is applied by an automatic labeler. On the other hand, when the Clark stiffness is 300 or more, on the other hand, the self-sustainability is so strong that it tends to be impossible to stick to a circular container.

The stretched resin film of the present invention may be used as it is, or may be used after being laminated on another resin film or the like. When further laminating, it can be laminated on a transparent film such as a polyester film, a polyamide film and a polyolefin film. The stretched resin film of the present invention can be used for various uses. For example, it is useful as a container label for various beverage cans and beverage bottles, a label for dry batteries and the like, and a packaging material for various containers.

Surface layer of the stretched resin film of the present invention (b)
Alternatively, printing can be performed on the opposite surface according to the purpose of use. The type and method of printing are not particularly limited. For example, printing can be performed using a known printing means such as gravure printing, flexographic printing, silk screen printing, offset printing, seal printing, and UV offset rotary printing using an ink in which the content is dispersed in a known vehicle. Further, printing such as metal deposition, gloss printing, mat printing, and fusion heat transfer printing can also be performed. In particular, it is preferable to perform metal deposition on the back surface.

A heat-shrinkable pressure-sensitive adhesive label can be obtained by subjecting one surface of the stretched resin film of the present invention to a known pressure-sensitive adhesive processing. Further, a heat-shrinkable coloring label can be obtained by applying a thermosensitive coloring method to one surface of the stretched resin film of the present invention. The resin stretched film of the present invention having the desired functions as described above can be effectively used as a label or a packaging material for various containers. In particular, it is extremely useful as a label for a dry battery utilizing the shrinkage property.

[0046]

The present invention will be described more specifically with reference to the following Examples and Comparative Examples. The materials, amounts used, ratios, operations, conditions, and the like shown below can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples. The materials used are summarized in the table below. In the table, “MF
"R" means melt flow rate.

[0047]

[Table 1]

(Examples 1 to 11 and Comparative Examples 1 to 7) The stretched resin films of the present invention (Examples 1 to 11) and the comparative stretched resin films (Comparative Examples 1 to 7) were produced according to the following procedures. Then, shrink labels were produced using these.

Propylene polymer (A), polybutene-1 (B), and petroleum resin (C) or hydrogenated terpene resin (D), organic or inorganic fine powder of the type and amount shown in Tables 2 and 3 (E) was mixed to prepare a blend. In Examples 1 to 3 and Comparative Example 1, the prepared blend was melt-kneaded with an extruder set at 230 ° C, extruded, and cooled to 50 ° C with a cooling device to obtain a non-stretched sheet. . In Examples 4 to 11 and Comparative Examples 2 to 7, the prepared two types of compound [i] and [b] were melt-kneaded with two extruders set at 230 ° C, respectively, and the compound [ The mixture [b] was laminated on the surface side of [b], extruded, and cooled to 50 ° C. by a cooling device to obtain a two-layer unstretched sheet. After heating this sheet, it was stretched between rolls in the machine direction. The stretching temperature and the stretching ratio at this time were as shown in Tables 2 and 3. Then, it heat-processed with the roll set to 90 degreeC, and cooled, and obtained the stretched film. Next, both sides of the obtained stretched film were subjected to a corona treatment of 40 w / m ² · min using an electric discharge treatment machine (manufactured by Kasuga Electric Co., Ltd.) to obtain a resin stretched film having the total thickness shown in Tables 2 and 3. I got

Next, a pattern designed with a trade name is gravure printed on the surface layer (b) of the obtained stretched resin film (ink: manufactured by Toyo Ink Co., Ltd .: trade name “CCST”).
After that, a release paper coated with 10 g / m ² of a pressure-sensitive adhesive was adhered to the back surface so that the pressure-sensitive adhesive-coated surface was in contact with the release paper to obtain a pressure-sensitive adhesive sheet. Next, only the label portion was punched to a predetermined size (the release paper was not punched).

The opacity, shrinkage and Clark stiffness of each of the produced stretched resin films were measured. Also,
For each of the manufactured labels, the ink adhesion, the automatic labeling property, and the heat shrinkability of the surface layer (b) were evaluated. The details of each test are as shown below.

1) Opacity The opacity was measured using a measuring instrument (manufactured by Suga Test Instruments Co., Ltd .: trade name "SM Color Computer") according to the measuring method of JISZ-8722.

2) Shrinkage ratio The stretched resin film previously punched out to 10 cm × 10 cm was immersed in a hot water bath set at 50 ° C. and a silicon oil bath set at 90 ° C. for 10 seconds, quickly taken out, and taken out in cold water at 20 ° C. After immersion in the film, the film length in the stretching direction (length after immersion) was measured. The dimensional heat shrinkage in the stretching direction (hereinafter simply referred to as “shrinkage”) was determined by the following equation.

(Equation 1)

3) Clark stiffness measuring instrument (manufactured by Kumagai Riki Kogyo Co., Ltd .: trade name "OUTOM")
ATIC CLARKSTIFFNESTESTE
R) was measured by the measurement method of JISP-8143.

4) Adhesion of ink on surface layer (b) Adhesive tape (trade name "Cellotape" manufactured by Nichiban Co., Ltd.) is adhered to the gravure-printed surface and pressed sufficiently, and then the adhesive tape is adhered. The film was peeled at a constant speed in a direction at 90 degrees to the surface. The removal of the ink from the stretched film was visually observed and evaluated according to the following criteria. ：: No ink was peeled off. △: There was resistance at the time of tape peeling, but most of the ink was peeled off, and there was a problem in practical use.

5) Suitability for automatic labeling Labels punched after being subjected to adhesive processing are automatically labeled with an automatic adhesive labeler (manufactured by Lintec Co., Ltd., trade name: Automatic Labeler MD-).
After labeling 100 sheets at 1) at a rate of 300 sheets / min so that the stretching direction of the label is in the direction of the circumference of the dry battery (single size), the state of sticking of the label was evaluated according to the following criteria. ：: All 100 sheets are stuck at the designated position △: 1 to 9 sheets out of 100 sheets were not stuck ×: 10 or more sheets out of 100 sheets were not stuck

6) Heat Shrinkability Dry Battery 50 Attached by Automatic Adhesive Labeler and Tensile
The individual batteries were passed through a hot blast stove set at 250 ° C. at a speed of 25 m / min, and the appearance of the heat-shrinked dry battery was evaluated according to the following criteria. ◎: Uniform shrinkage of the label at the head and buttocks of the dry cell ○: Slightly uneven shrinkage of the label at the head and buttocks of the dry battery, but no practical problem △: No shrinkage of the labels at the head and buttocks of the dry battery Uniform, poor appearance and problematic for practical use x: Label shrinkage at the head and buttocks of the dry battery was insufficient and it was raised and could not be used practically. The above test results were as shown in Tables 2 to 4. In addition,
In Comparative Examples 1 and 6, stretching was frequently broken, and in Comparative Example 7, the film was loosened during heat treatment.

[0058]

[Table 2]

[0059]

[Table 3]

[0060]

[Table 4]

As is apparent from the above results, the stretched resin film of the present invention has excellent rigidity in the stretching direction, excellent white opacity, small shrinkage during storage of the product, and large shrinkage during heating. Has features. Labels produced using the resin stretched film of the present invention are opaque,
The ink adhesion, labeling suitability, and heat shrinkability are all good, and the practicality is extremely high (Examples 1 to 11). On the other hand, the stretched resin film out of the conditions of the present invention has poor properties and is not practical (Comparative Examples 1 to 7).

[0062]

The stretched resin film of the present invention is a white, opaque heat-shrinkable film, and has excellent properties of high rigidity in the stretching direction, low shrinkage during storage of the product, and high shrinkage during heating. By using the stretched resin film of the present invention, a white opaque label or packaging material having excellent ink adhesion, labeling suitability and heat shrinkage can be provided. In addition, the production method of the present invention can produce these resin stretched films at low cost and easily. For this reason, the stretched resin film of the present invention can be effectively provided for various uses including labeling and packaging of dry batteries, can containers, bottle containers, and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 57/00 C08L 57/00 101/00 101/00 // B29K 23:00 B29K 23:00 45:00 45:00 105: 16 105: 16 B29L 7:00 B29L 7:00

Claims (14)

[Claims] 1. A propylene-based polymer (A) 30 to 79% by weight, a polybutene-1 (B) 3 to 25% by weight, a petroleum resin (C) and / or a hydrogenated terpene resin (D)
A stretched resin film comprising a uniaxially stretched film containing 3 to 25% by weight and 10 to 65% by weight of an organic and / or inorganic fine powder (E). 2. 45 to 85% by weight of propylene polymer (A), 5 to 30% by weight of polybutene-1 (B), petroleum resin (C) and / or hydrogenated terpene resin (D)
At least one surface of the uniaxially stretched film base material layer (A) containing 5 to 30% by weight and 5 to 45% by weight of an organic and / or inorganic fine powder (E) is provided with a propylene polymer (A) 30 to 79 % By weight, polybutene-1 (B) 3 to 2
1 containing 5% by weight, 3 to 25% by weight of petroleum resin (C) and / or hydrogenated terpene resin (D), 10 to 65% by weight of fine organic and / or inorganic powder (E)
A stretched resin film having an axially stretched film surface layer (b). 3. The method according to claim 1, wherein the propylene polymer has the following (a1):
The stretched resin film according to claim 1, which is selected from (a4) to (a4). (A1) 2 to 10% by weight of ethylene and propylene 9
(A2) 0-5% by weight of ethylene, butene-18-8-3
0% by weight and random copolymer of 92 to 65% by weight of propylene (a3) 0 to 5% by weight of ethylene, 65 to 9 of propylene
8.5% by weight and random copolymer of butene-10 to 30% by weight (a4) Propylene homopolymer 4. The method according to claim 1, wherein the petroleum resin (C) is (c1) to
The stretched resin film according to any one of claims 1 to 3, which is selected from (c5). (C1) a polymer obtained by cationic polymerization of a polymerizable composition containing a chain olefin having 5 carbon atoms (c2) a polymer obtained by thermally polymerizing a polymerizable composition containing dicyclopentadiene (c3) an aromatic olefin having 9 carbon atoms (C4) a copolymer obtained by cationic polymerization of a polymerizable composition containing a chain olefin having 5 carbon atoms and an aromatic olefin having 9 carbon atoms (c4) (c5) (C2) (c3) or (c
4) a hydrogenated polymer, or (c1) or (c)
2) Modified polymer obtained by introducing carboxylic acid group, maleic anhydride group and / or hydroxyl group into (c3) or (c4) 5. The stretched resin film according to claim 1, wherein a dimensional heat shrinkage in the stretching direction of the stretched resin film is 25% or more at 100 ° C. and 1% or less at 50 ° C. 6. The stretched resin film according to claim 1, wherein the Clark stiffness in the stretching direction of the stretched resin film is in the range of 10 to 300. 7. The resin stretched film has a total thickness of 30 to 250.
The stretched resin film according to any one of claims 1 to 6, wherein the thickness is in the range of µm and the thickness of the base material layer (a) is 50 to 98% of the total thickness. 8. The method according to claim 1, wherein the opacity is 20% or more.
8. The stretched resin film according to any one of 7. 9. The stretched resin film according to claim 1, wherein the back surface of the stretched resin film has a pressure-sensitive adhesive function. 10. A propylene polymer (A) 30 to 79.
%, Polybutene-1 (B) 3-25% by weight, petroleum resin (C) and / or hydrogenated terpene resin (D) 3-25% by weight, organic and / or inorganic fine powder (E) 10% 1% of a resin composition containing 65% by weight
A method for producing a stretched resin film, comprising a step of axial stretching. 11. A propylene-based polymer (A) 45 to 85.
5 to 30% by weight of polybutene-1 (B), 5 to 30% by weight of petroleum resin (C) and / or hydrogenated terpene resin (D), 5 to 30% by weight of organic and / or inorganic fine powder (E) On at least one side of the base layer (A) of the resin composition containing 45% by weight, 30 to 79% by weight of a propylene-based polymer (A) and 3 to 2 of polybutene-1 (B)
Surface of resin composition containing 5% by weight, petroleum resin (C) and / or hydrogenated terpene resin (D) 3 to 25% by weight, organic and / or inorganic fine powder (E) 10 to 65% by weight A method for producing a stretched resin film, comprising a step of forming a layer (b) and uniaxially stretching the formed laminate. 12. The stretching temperature of the uniaxial stretching is 65 to 15.
The method for producing a stretched resin film according to claim 10 or 11, wherein the stretching temperature is in a range of 0 ° C and the stretching ratio is 1.5 to 11 times. 13. The method for producing a stretched resin film according to claim 10, wherein a heat treatment is performed after the uniaxial stretching in a temperature range from the stretching temperature to 30 ° C. higher than the stretching temperature. 14. The uniaxial stretching is performed by stretching an object using a difference in peripheral speed of a roll group, or stretching is performed by holding the object between clips in a hot oven. 14. The method for producing a stretched resin film according to any one of 10 to 13.