JP2001329074A - Stretch film for food packaging - Google Patents

Abstract

(57) [Summary] [Problem] Non-chlorine type laminated stretch film for food packaging having balanced performance excellent in film forming property, transparency, mechanical strength, packaging workability, packaging finishability and deformation recovery property. Get. SOLUTION: The following component (A) is 30 to 60% by weight,
The component (B) is 15 to 30% by weight, and the component (C) is 5 to 20% by weight.
A stretch film for food packaging, comprising at least one mixed resin layer containing 0 to 30% by weight of the component (D) and the component (D) as a main component. (A) a polypropylene resin (B) a block copolymer of a vinyl aromatic compound and a conjugated diene or a hydrogenated derivative thereof (C) a random copolymer of a vinyl aromatic compound and a conjugated diene or a hydrogenated derivative thereof (D) Petroleum resins

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch film suitably used for food packaging, and more particularly to a stretch packaging film made of a chlorine-free material.

[0002]

2. Description of the Related Art Conventionally, as a stretch packaging film for a so-called prepackage in which fruits and vegetables, meat, side dishes, etc. are placed on a lightweight tray and overlapped with a film, a polyvinyl chloride-based film has been mainly used. . These have good packaging efficiency such as good packaging efficiency, good packaging finish, and excellent elastic recovery that returns to the original state even after applying deformation such as pressing the packed film with a finger, and good bottom sealability. This is because the merchandise and the consumer have the superiority of the quality that the value of the merchandise does not decrease such that the film is not easily peeled off during the transportation display.

However, in recent years, problems such as hydrogen chloride gas generated during incineration of a polyvinyl chloride film and elution of a large amount of a plasticizer have been regarded as problems. For this reason, various alternatives to the polyvinyl chloride-based film have been studied, and in particular, various stretch packaging films using a polyolefin-based resin composition have been proposed. For example, in JP-A-6-155678, an intermediate layer is formed of a mixed resin composition comprising a hydrogenated product of a polypropylene resin and a styrene-butadiene block copolymer, and ethylene-acetic acid is formed on both sides of the intermediate layer as front and back layers. In a stretch film in which a layer made of a vinyl copolymer is laminated, and in JP-A-7-178876, the intermediate layer is formed of a mixed resin composition consisting of a propylene-based polymer and a hydrogenated diene-based random copolymer. There has been proposed a stretch film in which a layer made of an ethylene-vinyl acetate copolymer is laminated as a front and back layer on both sides of the film.

However, in the structure of the stretch film proposed in Japanese Patent Application Laid-Open No. 6-155678,
Since the hydrogenated styrene-butadiene block copolymer is easily oriented in the forming direction (longitudinal direction) during the film formation process, the tear strength tends to be particularly inferior. There were problems such as easy opening of holes due to corners and projections, and generation of torn chips. Further, in the stretch film configuration proposed in JP-A-7-178876, film formation stability in inflation molding is poor due to a low crystallization rate, etc., and stable production cannot be performed. There was a problem that the packaging suitability was insufficient.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide not only an appropriate sliding property, self-adhesiveness and anti-fogging property, but also mechanical strength such as film forming property, transparency, tear strength, and cutting. It is an object of the present invention to provide a stretch packaging film having excellent balance of performance such as packaging workability, packaging finish, and deformation recovery.

[0006]

The present inventors have conducted intensive studies and found that, for example, a two-component constitution of a polypropylene resin and a hydrogenated product of a styrene-butadiene block copolymer, or a polypropylene resin and a styrene -It has been found that the disadvantages of the two-component constitution with the hydrogenated butadiene random copolymer can be solved in a balanced manner, and the present invention has been completed. The gist of the present invention is that the following component (A) is 30 to 60% by weight, component (B) is 15 to 30% by weight, component (C) is 5 to 20% by weight, and component (D) is 0 to 0%. The present invention relates to a stretch film for food packaging, comprising at least one mixed resin layer containing 30% by weight as a main component. (A) Polypropylene resin (B) Block copolymer of vinyl aromatic compound and conjugated diene or hydrogenated derivative thereof (C) Random copolymer of vinyl aromatic compound and conjugated diene or hydrogenated derivative thereof (D) Petroleum resins

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The stretch film of the present invention contains the following component (A) in an amount of 30 to
60% by weight, 15 to 30% by weight of component (B), 5 to 20% by weight of component (C) and 0 to 30% by weight of component (D)
It is a stretch film for food packaging characterized by having at least one layer of a mixed resin layer containing as a main component. (A) Polypropylene resin (B) Block copolymer of vinyl aromatic compound and conjugated diene or hydrogenated derivative thereof (C) Random copolymer of vinyl aromatic compound and conjugated diene or hydrogenated derivative thereof (D) Petroleum resins

The polypropylene resin as the component (A) is a homopolymer of propylene or a random copolymer or a block copolymer with another monomer copolymerizable with propylene. The three-dimensional structure is not particularly limited, and may be an isotactic, atactic, syndiotactic, or a polymer having a mixed structure thereof. Here, other copolymerizable monomers include ethylene, butene-1, hexene-1, 4-methyl-pentene-
1, α-olefins having 4 to 12 carbon atoms such as octene-1, and dienes such as divinylbenzene, 1,4-cyclohexadiene, dicyclopentadiene, cyclooctadiene, and ethylidene norbornene. Ethylene is preferred. When the polypropylene resin is a copolymer with another monomer copolymerizable with propylene, the content of the other monomer is usually 40% by weight or less, preferably 30% by weight or less. is there.

Examples of the random copolymer include a propylene-ethylene random copolymer, a propylene-ethylene-butene-1 copolymer, and a Hunt with controlled stereoregularity.
sman Polymer Corporation under the trade name "REXflex", and the block copolymer include a propylene-ethylene block copolymer and a reactor-type polypropylene-based elastomer. ) Tokuyama's trade name "PER", Chisso Corporation's trade name "NEWCON", Montel SDC Sunrise Co., Ltd.'s trade name "Catalloy", Sumitomo Chemical Co., Ltd. trade name “EXCELLEN EPX” and the like are commercially available.

[0010] These polypropylene resins may be used alone or in combination of two or more. Also, its melt flow rate (MFR)
(JIS K7210, 230 ° C., 21.18 N load) is usually 0.4 to 20 g / 10 min, preferably 0.5 to 10 g.
g / 10 minutes is used.

The component (B) is a block copolymer of a vinyl aromatic compound and a conjugated diene or a hydrogenated derivative thereof. Since such a copolymer generally has rubber elasticity and is soft, it gives elasticity to the film and effectively acts to reduce the tensile modulus of the polypropylene resin as the component (A). . Here, styrene is typical as the vinyl aromatic compound, but styrene homologs such as α-methylstyrene may also be used. Further, as the conjugated diene, 1,3-butadiene,
Examples thereof include isoprene, 1,3-pentadiene, and the like. These can be used alone or in combination of two or more. Further, as the third component, a small amount of a component other than the vinyl aromatic compound and the conjugated diene may be contained. However, when a double bond mainly composed of a vinyl bond in the conjugated diene portion remains, thermal stability and weather resistance are extremely poor. To improve this, 80% or more, preferably 95% of the double bond is improved. It is preferable to use one to which hydrogen is added as described above.

The ratio of the vinyl aromatic compound to the conjugated diene in such a copolymer is 3/97 to 40 by weight.
/ 60 is preferable. If the amount of the vinyl aromatic compound in the copolymer composition is less than 3% by weight, the rigidity of the copolymer itself is too low, and the polymerization productivity such as pelletization is easily reduced. On the other hand, 40% by weight. If the ratio exceeds, the rigidity of the copolymer itself becomes high, and the effect of adding the component (B) to the film, such as imparting elastic recovery or reducing the tensile modulus, tends to be insufficient. Specific examples of the component (B) include a styrene-butadiene block copolymer elastomer (trade name “TAFPRENE”), a hydrogenated derivative of a styrene-butadiene block copolymer (trade name of Asahi Kasei Corporation) "ToughTech", Shell Japan Co., Ltd. product name "Clayton G"), hydrogenated derivative of styrene-isoprene block copolymer (Kuraray Co., Ltd. product name "Septon"), styrene-vinyl isoprene block copolymer elastomer ( It is commercially available under the trade name of “Kuraray Co., Ltd.“ Hibler ”).

However, in the two-component system of the component (A) and the component (B), the component (B) tends to be oriented in the film forming direction (longitudinal direction) at the time of film formation, so that the direction perpendicular to the film forming direction ( (Transverse direction) tear strength tends to decrease, and when used in an automatic packaging machine, holes are easily formed due to sharp corners and protrusions of trays and products, and practical problems such as generation of tears are likely to occur. . Therefore, in the present invention, the component (C) is used in addition to the components (A) and (B).

The component (C) is a random copolymer of a vinyl aromatic compound and a conjugated diene or a hydrogenated derivative thereof. Here, the vinyl aromatic compound and the conjugated diene component and the weight ratio thereof can be the same as those described above for the component (B), and particularly, when the styrene content is 5 to 25% by weight and the conjugated diene portion is 5 vinyl bonds
More than 0%, preferably 60 to 90%, of a hydrogenated derivative of a styrene / conjugated diene random copolymer is (A)
It can be suitably used from the viewpoints of fine dispersibility (compatibility) in components and improvement in transparency. When the component (C) is mixed with the components (A) and (B), the component (C) is finely dispersed, so that the component (A) is easily oriented (B).
The orientation of the components can be relaxed and the decrease in tear strength can be reduced.

Specific examples of the component (C) include:
It is commercially available as a hydrogenated derivative of a styrene-butadiene random copolymer (trade name “Dinalon” by JSR Corporation). The details of the hydrogenated derivative of the styrene / conjugated diene-based random copolymer which can be suitably used in the present invention and the production method thereof are described in JP-A-2-158463, JP-A-2-305814, and JP-A-2-305814. It is disclosed in Japanese Unexamined Patent Publication No. 3-72512. Further, as a specific example of such a copolymer, a structure of hydrogenated styrene butadiene rubber is used, and a material called by the abbreviation of HSBR is a trade name of “Dynalon 132” by JSR Corporation.
"OP".

These copolymers of component (B) and component (C) can be used alone or in combination of two or more. The component (D) is a petroleum resin. Such petroleum resins effectively act for the purpose of further improving the suitability for packaging such as the stiffness and cutability of the film and the transparency. Here, petroleum resins include petroleum resins, terpene resins, cumarone-indene resins, rosin-based resins, and hydrogenated derivatives thereof. Examples of the above petroleum resins include alicyclic petroleum resins from cyclopentadiene or a dimer thereof and aromatic petroleum resins from the C9 component, and terpene resins include terpene resins and terpene-phenol resins from β-pinene. As the rosin resin, gum rosin, rosin resin such as wood rosin,
Examples thereof include esterified rosin resins modified with glycerin, pentaerythritolol, and the like. As the petroleum resins, it is preferable to use a hydrogenated derivative in terms of color tone, thermal stability, and compatibility. In addition, petroleum resins having various softening temperatures mainly depending on the molecular weight can be obtained, and the softening temperature is 100 to 150 ° C, preferably 110 to 1 ° C.
Those at 40 ° C. are preferably used. Specifically, Mitsui Chemicals Co., Ltd.'s trade names "Heylets" and "Petrogine", Arakawa Chemical Industries Co., Ltd.'s trade name "Alcon", Yashara Chemical Co., Ltd.'s trade name "Clearon", Idemitsu Petrochemical Co., Ltd. Commercially available products such as “Imarb” (trade name), “Escolets” (trade name) of Tonex Corporation can be used.

Next, in the mixed resin layer, the component (A) contains 30 to 6
The layer mainly contains 0% by weight, 15 to 30% by weight of the component (B), 5 to 20% by weight of the component (C), and 0 to 30% by weight of the component (D). However, the total of each component is 100% by weight. Here, if the content of the component (A) is less than 30% by weight or the content of the component ((B) + (C)) exceeds 50% by weight, the resulting film becomes too flexible, has no stiffness, and is cut. In addition, heat resistance is insufficient and heat resistance is insufficient, so that it is difficult to obtain practical heat sealing characteristics. On the other hand (A)
If the content of the component exceeds 60% by weight or [(B) +
(C)] If the content of the component is less than 20% by weight, the flexibility of the obtained film is reduced, the elastic recovery is also reduced, and the packaging suitability is poor. When the content of the component (C) is less than 5% by weight, the effect of relaxing the orientation of the component (B) is insufficient. On the other hand, when the content exceeds 20% by weight, the film-forming stability tends to deteriorate, which is not preferable. . Further, when the content of the (D) petroleum resin exceeds 30% by weight, the mechanical strength and low-temperature properties are reduced, and the film is easily broken, or the petroleum resin bleeds on the surface over time to form a roll. In such a case, problems such as blocking between the films are likely to occur. In the present invention, the component (D) is not an essential component and may not be added to the mixed resin layer. However, for the purpose of further improving the suitability for packaging such as stiffness and cuttability of the film and transparency, It is preferable to add 25% by weight.

According to the present invention, a stretch film comprising the above-described mixed resin layer can be obtained, and another non-chlorine-based material layer is laminated as a surface layer on at least one side, preferably both sides, of the mixed resin layer. Is preferred. Other resin layers include non-chlorine-based material layers such as polyolefin-based resins and flexible styrene-butadiene-based elastomers. By laminating these layers, the viscoelastic properties of the film are adjusted and the processability of the film is improved. In addition, the appearance, flexibility and tensile properties are improved to provide moderate strength and elongation, and elongation at low temperatures is improved. Here, as the surface layer, a polyolefin-based resin is particularly preferable in terms of surface characteristics and economy, and low-density polyethylene, linear ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer (EVA) ), Ethylene-alkyl acrylate copolymer, ethylene-alkyl methacrylate copolymer, ethylene-acrylic acid copolymer and the like are recommended.

In practice, EVA and / or a linear ethylene-α-olefin copolymer can be suitably used, and the mixing ratio can be appropriately determined. The EVA has a vinyl acetate content of 5 to 25% by weight,
Preferably 10 to 20% by weight, melt flow rate (M
FR (JISK7210, 190 ° C, 21.18 N load) of 0.2 to 5 g / 10 min is suitable. Here, when the vinyl acetate content is less than 5% by weight, the obtained film is hard, the flexibility and the elastic recovery are reduced, and the surface tackiness is hardly developed. On the other hand, if it exceeds 25% by weight, the surface tackiness is too strong, and the unwinding property and appearance are liable to deteriorate.

The linear ethylene-α-olefin copolymer has an α-olefin content of 5 to 25% by weight, preferably 10 to 15% by weight, and an MFR (JIS K7).
210, 190 ° C, 21.18N load) 0.2-5g
/ 10 minutes is preferred. If the α-olefin content is less than 5% by weight, the resulting film is hard, and it is difficult to obtain uniform extensibility during stretch packaging. Therefore, wrinkles are generated in the package, and the package is easily crushed.
If it exceeds, film forming becomes difficult or the unwinding property is liable to decrease. Further, as the α-olefin, butene-1, hexene-1, 4-methyl-pentene-1, and octene-1 having 4 to 8 carbon atoms are preferable, and these are used alone or in combination of two or more. Can be used.

When the MFR of both EVA and the linear ethylene-α-olefin copolymer is less than 0.2 g / 10 minutes, the extrudability decreases, while when the MFR exceeds 5 g / 10 minutes, the film forming stability is reduced. This is not preferable because the thickness tends to decrease, and the thickness unevenness, the decrease in the mechanical strength, and the variation easily occur. In general, the thickness of the film of the present invention is in a range used for ordinary stretch packaging, that is, about 8 to 30 μm, typically about 10 to 20 μm. When a laminated film is used, the ratio of the thickness of the mixed resin layer to the total thickness is 0.2 to 0.9, preferably 0.3 to 0.9.
0.8, and more specifically, 5 to 20 μm is preferable from the viewpoints of various properties and economy as a stretch film.

The film of the present invention can be obtained by melt-extruding a material from an extruder and forming the film by inflation molding or T-die molding. In the case of forming a laminated film, it is advantageous to co-extrude with a multilayer die using a plurality of extruders. Practically, it is preferable to melt-extrude the material resin from the annular die to perform inflation molding, and the blow-up ratio (bubble diameter / die diameter) at that time is preferably 4 or more, and particularly preferably in the range of 5 to 7. . As a cooling method at that time, either a method of cooling from the outer surface of the tube or a method of cooling from both the outer and inner surfaces of the tube may be used. Further, the film obtained here is heated to a temperature not higher than the crystallization temperature of the resin, and stretched 1.2 to 5 times in the longitudinal direction of the film using a speed difference between nip rolls.
Alternatively, the film may be biaxially stretched 1.2 to 5 times in both the vertical and horizontal directions.

The film of the present invention is not limited to the purpose of the present invention, and is intended to provide, for example, recycled resin generated from trimming loss or the like, antifogging property, antistatic property, slipping property, self-adhesive property and the like. The following various additives can be appropriately blended into the surface layer and / or the mixed resin layer.
Here, as the various additives, for example, those having 1 to 1 carbon atoms.
2, preferably an aliphatic alcohol fatty acid ester which is a compound of an aliphatic alcohol having 1 to 6 and a fatty acid having 10 to 22 carbon atoms, preferably 12 to 18 carbon atoms, specifically, monoglycerin oleate and polyglycerin Oleate, glycerin triricinoleate, glycerin acetyl ricinoleate, polyglycerin stearate, polyglycerin laurate, methyl acetyl ricinoleate, ethyl acetyl ricinoleate, butyl acetyl ricinoleate, propylene glycol oleate, propylene glycol laurate, pentaerythritol oleate, Polyethylene glycol oleate, polypropylene glycol oleate, sorbitan oleate, sorbitan laurate, polyethylene glycol sorbitan oleate, polyethylene glycol sol Tanraureto like, as well as, polyalkylene ether polyols, specifically,
Polyethylene glycol, polypropylene glycol, and the like, and further, at least one compound selected from paraffinic oils and the like are used in an amount of 0.1 to 12 parts by weight, preferably 1 to 12 parts by weight, based on 100 parts by weight of a resin component constituting each layer. It is preferable to mix 8 parts by weight.

[0024]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. In addition, various measured values and evaluations of the film displayed in this specification were performed as follows. Here, the direction of flow of the film from the extruder is referred to as the vertical direction, and the direction perpendicular thereto is referred to as the horizontal direction.

1) Transparency (Haze) The obtained film was measured with a haze meter according to ASTM D1003.

2) Tear strength B of JIS K7128
It was measured according to the law.

3) Suitability for stretch packaging Using a stretch film having a width of 350 mm, an automatic packaging machine (ISIDA Wmini MK-I manufactured by Ishida Co., Ltd.)
I) foamed polystyrene tray (length 200mm,
130 mm in width and 30 mm in height) were packaged, and the items shown in Table 3 were evaluated.

Example 1 Component (A) Propylene-ethylene random copolymer (ethylene content: 4 mol%, crystal melting peak temperature: 147 ° C., 230 ° C., MFR at a load of 21.18 N: 2.3 g / 10 (B) Component Hydrogenated styrene-butadiene block copolymer (styrene content: 13%, specific gravity: 0.90, MFR: 8 g / 10 min, Clayton G1657, manufactured by Clayton Polymer Co., Ltd.) ): 30% by weight (C) Component Hydrogenated styrene-butadiene rubber (styrene content: 10%, vinyl bond amount in conjugated diene portion: 78%, specific gravity: 0.89, MFR: 3.5 g / 10 minutes, Tg) : -50 ° C, DYNARON1320P, manufactured by JSR Corporation): 15% by weight

The mixed resin composition comprising the above three components was used as an intermediate layer, and EVA (vinyl acetate content: 15% by weight, 19% by weight) was used.
MFR at 0 ° C. and a load of 21.18 N: 2.0 g / 10
A three-layer annular die temperature of 190 ° C. so that the composition obtained by kneading 2.0 parts by weight of diglycerin monooleate as an anti-fogging agent into 100 parts by weight of each of the front and back layers has a thickness of 2.5 μm.
A total thickness of 15 μm (2.5 μm / 10 μm / 2.5 μm) by co-extrusion inflation molding at a blow-up ratio of 5.5
m) was obtained. Table 2 shows the results of evaluating the film forming properties, transparency, mechanical properties, suitability for stretch wrapping machines, and the like described above using the obtained films.

(Example 2) As shown in Table 1, the amounts of the three resins used in Example 1 were reduced to 40% by weight of component (A), 30% by weight of component (B), and 10% by weight of component (C). Example 1 was changed, except that as a component (D), a hydrogenated derivative of cyclopentadiene-based petroleum resin (softening temperature: 125 ° C.) was mixed at 20% by weight to obtain four kinds of mixed resin compositions.
As in the above, a film having a thickness of 15 μm was obtained. Using the obtained film, the same evaluation as above was performed, and the results are shown in Table 2.

(Example 3) As shown in Table 1, the four kinds of mixed resin compositions used in Example 2 were used as an intermediate layer, and the total thickness was 15 µm (4.5 µm / 6 µm / 4.5 µm). Was obtained in the same manner as in Example 2. Using the obtained film, the same evaluation as above was performed, and the results are shown in Table 2.

Comparative Example 1 As shown in Table 1, the component (A) used in Example 1 was 55% by weight of a propylene-ethylene random copolymer and the component (B) was a hydrogenated styrene-butadiene block copolymer. A film having a thickness of 15 μm was obtained in the same manner as in Example 1 except that an intermediate layer was formed of two kinds of mixed resin compositions of 45% by weight. Using the obtained film, the same evaluation as above was performed, and the results are shown in Table 2.

Comparative Example 2 As shown in Table 1, the component (A) used in Example 1 was 55% by weight of a propylene-ethylene random copolymer and the component (C) was 45% by weight of hydrogenated styrene-butadiene rubber. A film having a thickness of 15 μm was obtained in the same manner as in Example 1 except that the two kinds of mixed resin compositions were used as an intermediate layer. Was not obtained.

Comparative Example 3 As shown in Table 1, the mixing ratio of the four resins used in Example 2 was 65% by weight of the component (A), 15% by weight of the component (B), and 5% by weight of the component (C). D) A film having a thickness of 15 μm was obtained in the same manner as in Example 1, except that the component was changed to 15% by weight. Using the obtained film, the same evaluation as above was performed, and the results are shown in Table 2.

(Comparative Example 4) As shown in Table 1, the mixing ratio of the four resins used in Example 2 was 60% by weight of the component (A), 10% by weight of the component (B), and 5% by weight of the component (C). D) A film having a thickness of 15 μm was obtained in the same manner as in Example 1, except that the component was changed to 25% by weight. Using the obtained film, the same evaluation as above was performed, and the results are shown in Table 2.

(Comparative Example 5) As shown in Table 1, the mixing ratio of the four resins used in Example 2 was 30% by weight of component (A), 25% by weight of component (B), and 10% by weight of component (C). D) A film having a thickness of 15 μm was obtained in the same manner as in Example 1 except that the component was changed to 35% by weight. However, this film was severely blocked and could not be evaluated.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

From Tables 1 to 3, the films of Examples 1 to 3 having the components specified in the present invention and falling within the specified ranges are all comprehensive in film forming stability and various properties as a stretch film. It turns out that it is excellent. On the other hand, films having different components (Comparative Examples 1 and 2) and out of the range specified in the present invention (Comparative Examples 3 to 5) are inferior in film-forming stability and overall properties as a stretch film. You can see that.

[0041]

According to the present invention, the film has well-balanced performance excellent in film forming properties, transparency, mechanical strength such as tear strength, packaging workability such as cutability, packaging finish and deformation recovery. A laminated chlorine-free food packaging stretch film can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C08L 23/14 C08L 23/14 23/16 23/16 25/10 25/10 47/00 47/00 53 / 02 53/02 57/02 57/02 F term (reference) 3E086 AB01 AD13 AD17 BA04 BA15 BB55 BB57 BB87 CA01 CA17 CA18 CA22 4F071 AA12X AA15X AA20 AA20X AA21X AA22X AA39X AA75X AA76X AE20 BA14 AF30 AF03 AF53 BC01 4F100 AK02A AK04A AK07A AK09A AK63B AK63C AK64A AK68B AK68C AK73A AK80A AL02A AL03A AL05A AL05B AL05C AL06A AL09A BA02 BA03 BA06 BA07 BA10A BA10B BA10C BA15 GB23 JA04A JA06B JA06C JK03 JK08A JL01 JL05 JN01 YY00A YY00B YY00C 4J002 AC083 BA014 BB12W BB14W BB15W BC053 BL013 BL023 BP01X

Claims (4)

[Claims] (1) The following component (A) is 30 to 60% by weight,
The component (B) is 15 to 30% by weight, and the component (C) is 5 to 20% by weight.
A stretch film for food packaging, comprising at least one mixed resin layer containing 0 to 30% by weight of the component (D) and the component (D) as a main component. (A) Polypropylene resin (B) Block copolymer of vinyl aromatic compound and conjugated diene or hydrogenated derivative thereof (C) Random copolymer of vinyl aromatic compound and conjugated diene or hydrogenated derivative thereof (D) Petroleum resins 2. The polypropylene resin (A) is at least one selected from propylene homopolymer, propylene-ethylene random copolymer, propylene-ethylene-butene-1 copolymer and reactor-type polypropylene elastomer. The food packaging stretch film according to claim 1, wherein the stretch film is a polypropylene resin. (D) The petroleum resin has a softening temperature of 100.
~ 150 ° C petroleum resin or hydrogenated derivative thereof,
The food packaging stretch film according to claim 1, wherein 10 to 25% by weight is mixed in the mixed resin layer. 4. At least one surface of the mixed resin layer has a melt flow rate (MFR) (JIS K7210, 190
C, 21.18 N load) is 0.2 to 5 g / 10 min, and the vinyl acetate content is 5 to 25% by weight of the ethylene-vinyl acetate copolymer and / or the α-olefin having 4 to 8 carbon atoms. The stretch film for food packaging according to any one of claims 1 to 3, wherein a surface layer mainly composed of 5 to 25% by weight of a linear ethylene-α-olefin copolymer is laminated.