JPS5942632B2 - Packaging material with good adhesion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a packaging material with good adhesion, especially a packaging material with excellent packaging properties for obtaining a package in which a single item or an aggregate of articles packaged once housed in a box or the like is tightly packaged. The purpose of the present invention is to provide a packaging material having the following properties.

Furthermore, the present invention has excellent low-temperature thermal adhesion properties, sliding smoothness in a wide temperature range, hot plate releasability, etc., which are required when packaging products using automatic packaging machines, and excellent transparency and gloss. The present invention relates to a packaging material for obtaining a close-fitting package having the following properties. In recent years, sophisticated demands have been placed on the exteriors of foods, tobacco, industrial goods, daily necessities, etc.

For example, in food packaging, in addition to the characteristics of the exterior material such as moisture resistance, aroma retention, insect repellency, and oxygen barrier properties, sealed packaging also prevents tearing, improves appearance, insufficient sealing of thermally bonded parts during packaging, and insufficient adhesive strength. Problems such as poor airtightness from folded parts due to wrinkles in packaging materials are becoming more important. Furthermore, the odor of packaging materials is also a hygiene problem, and efforts are being made in the industry to reduce residual solvents. On the other hand, as automatic packaging machines have become increasingly faster and more efficient, the following characteristics are required for use in automatic packaging machines. In other words, in addition to the low-temperature thermal adhesion, the sliding property between the packaging material and the metal guide of the automatic packaging machine, the separability and sliding property between the packaging material and the hot plate, and the sliding property between the packaging material and the automatic packaging machine. These include the ability to prevent scratches and the ability to automatically feed packaging materials to automatic packaging machines. However, this alone cannot be said to be a complete close-tight packaging, and a gap is created between the packaged item and the packaging film. For this reason, some external force may catch on the sagging portion of the film and cause it to tear, making it one step more effective in enhancing the appearance. Packaging materials with heat-sealing properties include coating films manufactured by dissolving a low-melting point substance in an organic solvent and coating it on a base film; A laminated film in which the melting point polymerized laminated surface is facing upward, or a single film made of a mixture of polypropylene or the like with a low molecular weight thermoplastic resin, etc., have been proposed.

However, the film obtained by the coating method has a weak sealing strength at high temperatures and is not only unsuitable for the sealed package of the present invention, but also tends to cause the heat-sealed portion to separate or move (slip) due to the shrinkage stress during the heat-shrinking treatment. This not only impairs tight packaging but also prevents a perfect package. This means that the cohesive force of the sealing polymer is weak due to the use of a relatively low molecular weight polymer that can be dissolved in a solvent.
Another disadvantage is that it is difficult to completely eliminate residual solvent on the coating surface. A film obtained by mixing a low melting point polymer with polypropylene or the like has poor low-temperature sealing properties and may have poor transparency. Furthermore, since the film is flexible, its stiffness and rigidity are low, and automatic feeding becomes unstable, making it difficult to continuously wrap the film using an automatic packaging machine. Furthermore, although films mixed with low molecular weight thermoplastic resins exhibit sealing strength even at low temperatures, they have the disadvantage that their strength decreases as they are heated, making it difficult to obtain packaging with excellent sealing. . This is because the film is at a high temperature immediately after heat sealing, so the sealing strength in this state is weak, making it difficult to seal tightly and to package tightly. Attempts have also been made to layer a low-melting point polymer on a base film, but as with the case of mixing low-melting point polymers, in the case of successive biaxial stretching, in many cases the roll be fused to. For this reason, cold stretching is practically necessary, and a transparent film cannot be obtained under such conditions. For example, Tokuko Sho 41-4338
As seen in the publication, stretching in a low-temperature, high-stress field produces a large number of boards inside the film, resulting in a film with pearl-like luster. Another method is to stretch the base film with heated rolls, laminate a low melting point polymer on one or both sides, and then stretch the film again with a tenter. However, none of these materials has been found to allow for complete tight packaging, which is the first objective of the present invention. The packaging material of the present invention with good adhesion has the feature that it can be produced by a sequential biaxial stretching method with high productivity and high thickness accuracy. In response to these demands, we have arrived at the present invention as a result of intensive research in order to provide a sealed package on the market.

That is, the present invention contains 10 to 95% by weight of the following component A and 10 to 95% by weight of the following component B.
A film made of a polymer mixture containing 90 to 5% by weight of each component is adhered as a surface layer to one or both sides of a base film mainly composed of a polypropylene polymer, and the thickness of the laminated film is 5 to 200μ. , the individual thickness of the surface layer is 0.2 to 10μ, and the total thickness of the surface layer accounts for 0.5 to 50% of the total thickness of the packaging material,
and a copolymer with contractile cancer.

The polypropylene polymer forming the base film layer is a propylene-based polymer having a melting point of 140° C. or higher, preferably 150° C. or higher, such as isometric polypropylene having an isotactic index of 85% (by weight) or higher. , an ethylene/propylene copolymer with an ethylene content of 7% (weight) or less, a copolymer of propylene with a propylene content of 90% (weight) or more and an α-olefin having 4 to 6 carbon atoms, etc. as the main components. , or a mixture of these polymers.

The polypropylene polymer preferably has an intrinsic viscosity (tetralin solution at 135° C.) of 1.6 to 3.0 d1/t. In particular, it is preferably 1.6 to 2.5 d1/t.
If the intrinsic viscosity is less than 1.6 d1/1, it is difficult to obtain a transparent packaging material, and if it exceeds 3.0 d1/t, the extrudability decreases, making it particularly difficult to obtain a packaging material for the exterior of a package suitable for the present invention. This results in a packaging material that has a poor appearance, poor gloss, and reduces the internal product value. In the present invention, a low molecular weight thermoplastic resin may be blended into the base film, but the low molecular weight thermoplastic resin used here forms a mixture with good miscibility with the polypropylene-based polymer mixed together, and softens. Point (measured according to ASTM-D36-26)
is in the range of 70°C to 150°C, is thermally stable above 150°C, and preferably has a melt viscosity of about 20,000 centipoise or less at 200°C. Here, the term "thread compatibility" means that no layer separation occurs when polypropylene and the above-mentioned low molecular weight thermoplastic resin are mixed. Also, thermally stable means that there is no permanent change in the properties of the resin even after heating at a predetermined temperature for one hour in the presence of air. Additionally, the melt viscosity was measured using a Bruckfield viscometer heated to the indicated elevated temperature according to ASTM test method Dl 824-66. Examples of low molecular weight thermoplastic resins include natural and synthetic waxes, hydrocarbon resins, rosins, dammars, phenolic resins, chlorinated aliphatic hydrocarbon waxes, and chlorinated polyaromatic hydrocarbons. As a natural wax,
There are wood waxes, beeswaxes, spermaceti waxes, etc. Synthetic waxes include those made into low-molecular-weight polymers by thermal cracking, or low-molecular-weight polymers made by known polymerization methods starting from monomers such as ethylene and propylene. means synthetic wax etc.

((Hydrocarbon resin) refers to hydrocarbon polymers derived from coke oven gas, coal tar fractions, cracked and deeply cracked petroleum feedstocks, essentially pure hydrocarbon feedstocks or turpentine; Examples of typical hydrocarbon resins include coumaron-indene resin, petroleum resin, styrene resin, cyclopentadiene resin, and terpene resin.

These resins are described in Kirk Osma's Encyclopedia of Chemical Technology, 2nd edition, Volume 11, 2.
42-255 (1966). ((
Coumaron-indene resin refers to a hydrocarbon resin recovered from coke oven gas but obtained by polymerization of the resin formed present in coal tar distillate, phenol-modified coumaron-indene resin, or derivatives thereof. , these resins are described in the above literature, 2nd edition, Vol. 11, 243-24.
It is described on page 7.

...Petroleum resin" refers to a hydrocarbon resin obtained by catalytic polymerization of deeply cracked petroleum raw materials, and these petroleum raw materials generally include styrene, methylstyrene, vinyltoluene, indene, methylindene, butadiene, isoprene, Contains a mixture of resin formers such as biperylene and pentylene.

This resin is described in the above-mentioned document, 2nd edition, volume 11, pages 248-250. ((Styrene polymer) refers to a low molecular weight homopolymer of styrene, or a copolymer containing styrene and, for example, α-methylstyrene, vinyltoluene, butadiene, etc.

(Cyclopentadiene resin refers to cyclopentadiene homopolymers and copolymers derived from coal tar fractions or separated petroleum gas.

These resins are produced by holding cyclopentadiene-containing raw materials at elevated temperatures for considerable periods of time. Depending on the temperature maintained, either dimers, trimers or high polymers are obtained. These resins are described in the above literature, 2nd edition, Volume 11, 25.
It is described on pages 0-251. x Terpene resin refers to polymers of terpenes, which are hydrocarbons of the general formula ClOH, 6, present in most essential oils and plant oleoresins, and phenol-modified terpene resins.

Suitable terpenes include, for example, α-pinene, β-pinene, dipendene, limonene, myrcene, bornylene, gamphene and similar terpenes. This resin is described in the above-mentioned document, 2nd edition, volume 11, pages 252-254. ...Rosin...refers to resinous substances and rosin esters naturally occurring in pine tree oleoresins, modified rosins such as fractionated, hydrogenated, dehydrogenated or analogous thereof.

These substances are described in the above-mentioned literature, Vol. 17, pp. 475-505. ``Danmaru'' refers to a colorless to yellow substance or its analogues that naturally exist in plants of the Futabaraceae, Orchidaceae, etc., and this substance is published by Kyoritsu Shuppansha.
It is described in the Encyclopedia of Chemistry, Vol. 5, page 776 (published in 1968).

(t Phenol resin refers to a reaction product of phenols and aldehydes.

In addition to phenol itself, cresol, xylenol, p
-Tert-butylphenol, P-phenylphenol or analogs thereof are mentioned as the phenolic component,
Formaldehyde is the most common altehyde, but aldehydes include acetaldehyde, furfuraldehyde, and the like. These resins are described in the above-mentioned Encyclopedia, Vol. 15, pp. 176-207.
・・Chlorinated aliphatic hydrocarbon wax... is usually (・
It refers to something like chlorinated paraffin wax called chlorinated wax, and the typical one has a chlorine content of about 30 to 7
Contains 0% by weight.

...Chlorinated polynuclear aromatic hydrocarbons... Chlorinated hydrocarbons having two or more aromatic rings, such as two or more chlorinated biphenyl, terphenyl, etc., or a mixture thereof. .

Typical ones contain about 30-70% chlorine by weight. The base film layer in the present invention may further contain other polymers in an amount that does not deteriorate its properties, and the packaging material has improved automatic packaging properties by containing an antistatic agent, a lubricant, an antilocking agent, etc. can be obtained.

In order to obtain a sealed package, the film is attracted by static electricity in the packaging material supply section of an automatic packaging machine, wrapped around the blade of a cutter, or pulled by electrostatic attraction to a guide plate, which causes the film to become stuck to the packaging material. It must be avoided that the supply does not reach the packaged item in a constant and direct manner.

Regarding this point, the present inventors discovered the following new fact. That is, the phenomenon of static electricity generated by automatic packaging machines can be significantly improved by incorporating an antistatic agent into the base film layer of the film. In particular, there is an acceleration phenomenon when a low molecular weight thermoplastic resin is mixed, and by promoting it, a more remarkable effect is exhibited and the film supplyability is improved. In the present invention, at least one side of the base film layer contains 10 to 95% by weight of the following component A and 9% by weight of component B.
A film consisting of a polymer mixture containing 0 to 5% by weight in each case is glued as a surface layer.

Component A: A copolymer of propylene and ethylene with an ethylene copolymerization ratio of 0.5 to 10% by weight.

Component B: A copolymer of butene and an α-olefin other than butene, with a copolymerization ratio of 70 to 99% by weight.

The A-component polymer, a copolymer of propylene and ethylene, has an ethylene content in the range of 0.5% to 10% by weight.

A polymer having a melting index of 0.5 to 10 (7/10 minutes) is preferable. More preferably, the copolymer is a random copolymer with an ethylene content of 2.5 to 6% (by weight), most preferably a copolymer with an ethylene content of 3.5% to 6% (by weight).
It is a random copolymer of 6% to 6% by weight. In particular, when the enalene content is 3.6% (by weight) or more, it has an extremely large practical advantage in that heat sealing properties are unlikely to deteriorate due to surface oxidation treatments performed to improve adhesion such as printing and vapor deposition. something was discovered. The melting index is 1.
0 to 10 (y/10 minutes). Ethylene content is 0.
At 5% by weight, it is difficult to mix uniformly with the butene-based polymer (component B) described below, resulting in poor transparency and gloss, and in extreme cases, a semi-glossy or semi-transparent film. Moreover, if the ethylene content is 10% by weight or more, there is a drawback that the slippage in a heated state deteriorates, wrinkles and scratches occur in the package, and it becomes impossible to obtain a close-fitting package. The copolymer of butene and α-olefin other than butene, which is the B component polymer forming the surface layer, contains 70% to 99% (by weight) of butene, and contains α-olefin other than butene. The copolymer is a copolymer containing a copolymer component having 2 to 10 carbon atoms (excluding 4 carbon atoms) (e.g., ethylene, propylene, benzene, hexene, 4-methylbenzene-1, octene, decene, etc.). It is a combination. If the putene content in the copolymer is less than 70% (by weight), there will be no low-temperature heat-sealing properties, and the friction coefficient at high temperatures will be high, exceeding 1.4, resulting in heat sealability. At times, scratches and wrinkles occur in the film or sheet due to poor slippage, making it impossible to obtain a sealed package using an automatic packaging machine. Furthermore, when the sequential biaxial stretching is carried out, adhesion and fusion to the heated stretching rolls are likely to occur, making it impossible to commercially obtain a packaging material consisting of a film or sheet that is smooth and free from scratches and has an excellent appearance. If the content of butene is 99% (by weight) or more, the transparency of the film will be poor, and it will not be possible to obtain a translucent package in which the contents can be clearly seen. A component polymer and B
The mixing ratio with the component polymer is 10 to 95% (by weight) of the former;
The latter is 90-5% (by weight). When a low-molecular thermoplastic resin is mixed in the layer, the above polymer mixtures 75 to 97 (
weight)% and said low molecular weight thermoplastic resin 3-25 (weight)
Consists of %. In the present invention, it is preferable to mix 0.01 to 0.15 parts by weight of silicone oil with respect to 100 parts by weight of the above polymer mixture.

Silicone oils that can be used in the present invention include polydimethylsiloxane, polymethylphenylsiloxane, olefin-modified silicone, polyether-modified silicone modified with polyethylene glycol or polypropylene glycol, olefin/polyether-modified silicone, epoxy-modified silicone, and amino-modified silicone. , is a silicone oil containing modified siloxane bonds such as alcohol-modified silicone. Among the silicone oils, olefin-modified silicone, polyether-modified silicone, olefin/polyether-modified silicone, etc. are particularly excellent. The silicone oil improves the coefficient of friction of the film when heated, reduces the sliding resistance that occurs during hot plate sealing in automatic packaging machines, and prevents wrinkles, resulting in a beautiful appearance and high sealing performance. The basis for obtaining a film that maintains the performance of adhesion to the packaged object without sagging can be created. In addition, it is possible to prevent a decrease in gloss due to sliding and obtain a beautiful seal. In the present invention when silicone oil is used in combination, the high temperature friction coefficient is reduced to 1 when performing sliding heat sealing.
．． It can be reduced to 4 or less. This is an important requirement to achieve the above purpose. The silicone oil preferably has a viscosity of 50 to 10,000 centistokes at room temperature, more preferably a low viscosity of 50 to 300 centistokes. In addition to the silicone oil, ethylene oxide adducts of star oil with a softening point of 700C to 140C, oxidized synthetic waxes, higher fatty acid alkyl esters, polyhydric alcohol alkylate ethylene oxide adducts, fatty acid amide, etc. may be used in combination. The effect can be further enhanced. The mixture of these is 1 to 300 parts, especially 50 parts to 100 parts of silicone oil.
It is desirable to use the amount in the range of 300 parts to 300 parts. By using this additive in combination with silicone oil, it prevents stick slips at room temperature to 100℃ or below, which tend to occur when silicone oil alone is used, and smoothes the sliding on various metal guide plates of automatic packaging machines. This can prevent packaging defects. Furthermore, it improves slippage under high temperature and pressure, which is extremely important for obtaining the sealed package of the present invention. This specific value is a high temperature friction coefficient of 1.4 or less, preferably 1.0 or less.
The silicone oil and the above-mentioned additives are not only good, but also tend to reduce the heat sealability of the film or sheet, and also tend to reduce the transparency. Therefore, simply adding it tends to reduce the low-temperature heat-sealing properties, resulting in heat-sealing at a slightly higher temperature. The mixing range of the present invention indicates a preferable mixing amount that satisfies this point. Generally, when heat sealing is performed at high speed and high temperature using an automatic packaging machine, the surface of the film or sheet is damaged and thermal shrinkage occurs, making it impossible to obtain a smooth sealing surface.

That is, biaxially stretched films such as polypropylene have high crystallinity and melting point, and cannot achieve uniform shrinkage like polyvinyl chloride and the like. In the case of biaxially stretched polypropylene film, the portion that comes into contact with the hot plate contracts, and depending on the contact conditions, a sealing surface that is extremely uneven can be obtained. This phenomenon causes a partial seal failure due to the occurrence of unevenness in the tightly sealed package which is the object of the present invention, and a highly airtight package cannot be expected. In order to obtain these close-fitting and sealed packages, it is of course possible to perform low-temperature heat sealing as described above.
It is necessary that the sealing strength of the heat-sealed part is strong even in the heated state, and that the coefficient of friction in the heated state is low. Specifically, the heat seal strength at 120℃ is 40y/? The above is desirable. The heat-sealed package is then heat-shrinked using a heat-shrinker such as a heat-shrink tunnel. However, if the heat-sealing strength decreases after heat-shrinking, the seal part may come off or shift due to shrinkage stress, resulting in loss of adhesion. It will get wet, and of course the sealing performance will deteriorate. The heat-sealing strength retention rate of the heat-shrinkable packaging material of the present invention is 60% or more, preferably 80% or more. Further, it is desirable that the friction coefficient at high temperature is, for example, 1.4 or less at 12°C. Furthermore, in order to heat-shrink the article after packaging to obtain a completely adhesive package, the present invention requires not only the above-mentioned properties but also the following shrinkage properties. science fiction
When (SFm and SFt) are 3.5% or more, it is possible to eliminate the gap that occurs between the packaged object and the packaging material over a wide heat shrinkage temperature range when automatically packaged.

Further, by satisfying 1st-Sml≧1.5%, it is possible to avoid wrinkles remaining at the corners of the package when the article is packaged and then heat-treated to form a shrink-tight package. The state of occurrence of wrinkles is shown in FIG. Also, 1st-
The value of Sml and the state of wrinkles are shown in FIG. On the other hand, (SF
If t-St) and (SFm-Sm) are not each 1.15% or more, relatively large wrinkles will remain in the form of folds when the article is packaged and then heat-shrinked.

If wrinkles or folds remain, it will not only give a poor appearance but also cause damage due to snagging during transportation or handling. The heating method of the heat shrinker (heat shrink oven) includes infrared heating, electric heating, flame heating, hot air heating, and hot water heating.

As for the manufacturing method of the packaging material of the present invention, layers A and B can be bonded together using an adhesive, but layers A and B are extruded from separate extruders, and a composite flow is produced in a molten state. A co-extrusion method of extrusion molding, a method of separately melt-extruding and laminating before cooling and solidifying, or a method of gluing one film in a melt-extruded state to an unstretched or stretched film or sheet that has been cooled and solidified on the other side. Alternatively, a composite film or sheet can be obtained by a method of continuously stretching the film or the like.

These methods may be used to form either a flat film or an ape-shaped film, and although the present invention can be used even if the film is not stretched, it is preferable to use a film that has been at least uniaxially stretched. Particularly preferably, biaxial stretching provides a layer-effective sealing material. A feature of the packaging material of the present invention is that it can be manufactured by a sequential biaxial stretching method in which heated rolls are used during longitudinal stretching, and of course simultaneous stretching is even easier.

The laminated film of the present invention is advantageous because sequential biaxial stretching can obtain a packaging material with good heat-sealing strength by obtaining a strong composite layer binding force between the layers, and can produce a laminate economically. The significance is extremely high. Suitable conditions for stretching will be described below.

In case of uniaxial stretching, 3.5~
Stretch 10 times.

The stretching temperature is usually 100 to 160°C in the case of roll stretching, and 140 to 165°C in the case of tenter stretching. In the present invention, when the film is sequentially stretched biaxially, 3.5 to 10 times in the longitudinal direction, preferably 3.8 to 7 times
．． Stretched 5 times, 4 to 12 times in the transverse direction, preferably 6 to 9 times. When simultaneous biaxial stretching is carried out, it is carried out at 140 to 165°C. In the case of sequential biaxial stretching, the temperature in the first stage is 100°C to 16°C.
0°C, preferably 110°C to 130°C, second stage 140°C
The temperature is from 145°C to 160°C, preferably from 145°C to 160°C.
Although it is not necessary to carry out heat treatment after stretching, it may be carried out within a range that does not cause loss of the heat shrinkage characteristics due to changes in the film over time, reduction in the winding tightness of the product roll, etc. Generally, it is 3 to 60 seconds at 5'C to 135C. In order to obtain a close-fitting, sealed package, when the object to be packaged is immediately tightly and hermetically packaged with the packaging material of the present invention, or the object to be packaged is first shrunk into a box by a certain number and then the box is wrapped in one or more boxes. A large number of products may be hermetically packaged using the laminated packaging material of the present invention.

In either case, it is sufficient that the adhesive is thermally melted and bonded in close contact with the packaged item. The thickness range of the laminated packaging material used in the present invention is determined depending on its use as a close-contact packaging body, and is in the range of 5 to 200 μm.

A commonly used range is 15-60μ. The thickness of the inner surface layer of the packaging material of the present invention is 0.2 of the total thickness of the packaging material.
~50% range. The packaging material of the present invention may have a metal vapor deposited layer formed on a portion of the surface layer.

Furthermore, the surface layer can be printed, and a metal vapor deposited layer can also be formed after printing. It is also possible to perform an anchor coating using a conventional anchor coating agent before metal vapor deposition. Examples of anchor coating agents include thermosetting types such as polyisocyanate, urethane, and melamine, polyethyleneimine, titanium, acrylic ester, ethylene vinyl acetate, vinylidene chloride, chlorinated polyolefin, and linear. Various types such as copolyester types can be used alone or in combination. It is also optional to provide a resin protective layer on the outer surface of the metal vapor deposited layer. When printing, either pigment-based or dye-based ink can be used. When the packaging material of the present invention is used to tightly package an article using an automatic packaging machine and then pass it through a heat shrinker to form a tightly packaged product, the thickness of each surface layer is 0 within the above thickness ratio range. .2 to 10μ, particularly preferably about 0.2 to 3μ.

Before describing embodiments of the present invention, a measurement method will be described.

1) Base: Measured using "Base Tester" manufactured by Toyobo Seiki Co., Ltd. according to JIS-K-6714.

2) Automatic feeding ability: The packaging material was automatically fed and evaluated using a W-37 model packaging machine manufactured by Tokyo Automatic Machinery Co., Ltd.

3) Wrinkles on the heat-sealed part: Wrinkles on the surface heat-sealed with the automatic packaging machine used in 2) above were evaluated.

4) Heat sealing strength: Pressure 1Kf/CrAXl. After heat-sealing under conditions of 0 seconds, the peel strength was measured at a rate of 200 mm/min.

5) Adhesive packaging properties: Appearance of the packaged product after being packaged with the automatic packaging machine used in 2) above and passed through a heating oven to cause heat shrinkage.

△ 4 IJ 4 Hi V~゛0 6) Free heat shrinkage SF: Film width 15 mm, length 30
07v! t, mark the length between gauges 200 mJ1, leave the sample free and heat shrink it at 12'C, and the length before and after shrinkage L, L! It was calculated using the following formula.

7) Heat shrinkage rate under restraint S: Fix the film to a pair of parallel sides of a rectangular frame of 110 x 7O, and heat shrink it at 12°C without fixing the other pair of parallel sides. It was calculated using the following formula from the lengths L and L'.

Example 1 The base layer 1 was made of 90% (by weight) of isotactic polypropylene with an intrinsic viscosity of 2.0 d1/7 (using a 135°C tetralin solution) and a petroleum resin (argon P-
115) of a mixed composition consisting of 10% (by weight)
part by weight, 1.0 part (by weight) of an alkylamine ethylene oxide adduct and 0.5 part (by weight) of glycerin stearate were mixed.

On the other hand, as the surface layer 2, a butene-1/ethylene copolymer containing 4.5% (by weight) ethylene (melt index 2.5t
/10 minutes) 50 (wt)% and butene content 95 (wt)
% butene/ethylene copolymer 50% (by weight) polymer mixture to 100 parts (by weight) of glycerin fatty acid ester 0
．． A composition was used in which 4 parts by weight, 0.5 parts by weight of hydroxystearamide (Diaamide KH, manufactured by Nippon Kasei), and 0.1 parts by weight of polyethylene wax (molecular weight 2000) were mixed. These compositions were melt-extruded using two extruders to obtain 2/1/2 three-layer unstretched films. The unstretched film has a thickness of 1000μ and is stretched 5 times in the machine direction at 130°C, followed by 155°C in the transverse direction.
Stretched 8.0 times, then passed through a temperature-controlled oven for 8 seconds while giving a relaxation rate of 4% at 100°C, and cooled by forcibly blowing air at 20°C. A stretched film was obtained. This film has a surface tension of 40 dynes/(
1771 with corona discharge treatment and printed on the surface (
1) and (6) which were printed and then metal vapor-deposited were prepared, and a medicine case was packaged using an overlap machine. After packaging,
The heated air shown in Table 1 was blown from above and below and passed through an oven for the time shown in Table 1 to shrink the outer film to obtain a tight package. Comparative Example 1 Biaxial stretching was carried out in the same manner as in Example 1, and then 15
It was subjected to 5% relaxing heat fixation at 5° C., treated in the same manner as in Example 1, and packaged in the same manner.

Comparative Example 2 Composite biaxial stretching was carried out in the same manner as in Comparative Example 1, except that a propylene/ethylene copolymer with an ethylene content of 3.4% (by weight) (Ml 2.5 l/10 min) was used as the constituent polymer of the surface layer 2. It was made into a film.

The obtained film was packaged using an automatic packaging machine in the same manner as in Example 1, and passed through a shrink oven under the same conditions.
Comparative Example 3 Isotactic polypropylene (intrinsic viscosity 2.0 d1/y) 60 (weight)% and polybutene-14
The same content as the additive formulation of the base layer of Example-1 was mixed with the composition containing 0 (weight)%, and the mixture was melt-extruded to obtain an unstretched film with a thickness of 1000μ, and the film was heated at 110°C in the machine direction. Stretched 5.0 times, then stretched 8.0 times in the transverse direction at 145°C.
Stretched 0x and heat-set under the same conditions as Comparative Example-1 to a thickness of 25μ
A biaxially stretched film was obtained.

The biaxially stretched film was automatically packaged in the same manner as in Example-1,
It was also passed through a heat shrink oven. In the packaging material of the present invention, the base value was low, the packaged items looked beautiful, there were few wrinkles in the heat-sealed portion of the package, and the package was packaged extremely tightly after passing through the shrink oven. The extent of this can be judged from the length of the residual slack. In Comparative Example 2, since automatic feeding was not possible, packaging was performed intermittently and then shrink-wrapped. However, tight packaging was difficult. Next, Table 2 shows the changes in the packaging material after close-contact packaging.

In addition, Comparative Examples 1 to 3 are 13'CXO. Since even 5 minutes did not result in tight packaging, the shrinkage conditions were set to 150°C for 0.5 minutes.
Example 2 After printing on the corona-treated surface of the film of Example-1, an anchor coating was applied with a urethane adhesive, and then vacuum deposition was performed on the surface. I rapped.

As a result, the automatic supply performance became even better, and after overwrapping, heated air of 185°C was injected for about 2 seconds at a wind speed of 15 m/sec in the shrink tunnel to shrink it.
An adhesive package was obtained.

Both the ink layer and the metal vapor deposited layer had good gloss and no discoloration.

An unstretched film with a thickness of 1000 μm was obtained using the same composition method as in Example 3, Comparative Example 4, and Example 1, and the unstretched film was sequentially stretched and heat-treated in the longitudinal direction and the transverse direction at the temperature and magnification shown in the table below.
The film was then relaxed and cooled in the same manner, and a drug case was wrapped in the same manner using an overlap machine.

The results are shown below. Adhesive packaging properties are determined by wrapping the package at 120℃
This is the data after passing through the oven for 1 minute. A, B,
G, K, L, and M are comparative examples.

Example 4, Comparative Example 5 The thickness of the surface layer was changed using the same composition and method as in Example 1 (
(The overall thickness was the same), film was formed and stretched, and a packaging test was conducted in the same manner.

The results are shown below: 0. S and T are comparative examples.

Comparative example 6 Intake polypropylene (intrinsic viscosity 2.1d
1/y) was melt-extruded at 260°C and cooled with a cooling roll at 25°C to produce an unstretched sheet with a thickness of 1125μ.

The sheet was heated 5.0 times in the vertical direction at 145°C and 1 times in the horizontal direction.
It was stretched 9.0 times at 60°C.

Obtained film 25H0) Rooster 1k right 119n℃ 11
r SE boast AQPm 26%, SFt 2 28%? It was hot. Similarly, Sm2 was 17% and St was 18%. ! St-S
mI=1.0%, SFt-St=10%, SFm-Sm
=9%.

Since this film does not have heat-sealing properties, it is impossible to automatically package it in a cigarette hold type, and it also has poor automatic feeding properties, so it was bonded by melt-sealing on three sides.

After packaging, the product was shrunk at 120° C. for 1 minute, but the heat-sealed portion did not reach the predetermined position of the packaged object and was distorted, resulting in many wrinkles at this portion and at the corners of the packaged object. Example 5 In Example 1, the polymers constituting the surface layer were propylene ethylene copolymer (copolymerization ratio 95:5 weight ratio) and butene-ethylene-propylene copolymer (copolymerization ratio 90:5:5).
(weight ratio) was used at a ratio of 50/50 (weight ratio), and the tension heat treatment temperature and time of the film were as follows.

Packaging materials were obtained under otherwise the same conditions.

[Brief explanation of the drawing]

Figure 1 shows the shape of the package when wrinkles occur at the corners.

Claims (1)

[Scope of Claims] 1 10 to 95% by weight of the following component A and 90% of the following component B
A film made of a polymer mixture containing ~5% by weight, respectively, is adhered as a surface layer to one or both sides of a base film mainly composed of a polypropylene polymer, and the thickness of the laminated film is 5 to 200μ, and the surface The individual thickness of the layers is 0.2-10μ, the total thickness of the surface layer accounts for 0.5-50% of the total thickness of the packaging material, and the shrinkage is SFm≧3.5%, 1SFt≧3. 5% formula 2 |St-Sm|≧1.5% formula 3 SFt-St≧1.15% formula 4 SFm-Sm≧1.15% formula 5 SF: Free heat shrinkage rate at 120°C S: at 120°C Heat shrinkage rate under restraint m: An auxiliary symbol indicating the longitudinal direction t: Adhesive laminated packaging material that satisfies the following in the lateral direction. Component A: A copolymer of propylene and ethylene with an ethylene copolymerization ratio of 0.5 to 10% by weight. Component B: A copolymer of butene and an α-olefin other than butene, with a copolymerization ratio of 70 to 99% by weight. 2. An adhesive metal vapor-deposited laminated packaging material, wherein a metal vapor-deposited layer is formed on a portion of the surface layer of the adhesive laminated packaging material according to claim 1. 3. The surface layer of the adhesive laminated packaging material according to claim 1 or 2 contains 0.01 parts by weight of silicone oil per 100 parts by weight of a polymer mixture containing a component A polymer and a component B polymer, respectively. An adhesive laminated packaging material formed from a composition containing ~0.15 parts by weight. 4. The base film of the adhesive laminated packaging material according to claim 1, 2, or 3 comprises 80 to 98% by weight of a polypropylene polymer and 20% by weight of a low molecular weight thermoplastic resin.
An adhesive laminated packaging material which is a film containing ~2% by weight. 5 Claims 1, 2, 3, or 4
The adhesive laminated packaging material according to item 1, wherein the base film of the adhesive laminated packaging material is a film containing an antistatic agent in its constituent polymer.