JP3380173B2 - Food packaging film - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article packaging
For transparency, flexibility, tear strength and resilience
Excellent heat sealing, especially pre-stretch thrust
Lifting automatic packaging machine (hereinafter simply referred to as pre-stretch automatic packaging
Food packaging film). [0002] Food packaging, especially for fresh fish, meat, fruits and vegetables, etc.
For fresh food packaging, it has excellent transparency and flexibility,
A number of stretch wrap films have been developed
Food packaging film (hereinafter simply referred to as film)
Widely used as. Film packaging methods include
Hand packaging using handler wrapper, push-up type automatic packaging
There is automatic packaging using a machine and a pillow type automatic packaging machine,
In recent years, a pre-stretch automatic packaging machine has been developed,
Automatic packaging using machines is rapidly spreading. This automatic package
As a specific example of the mounting equipment, a pre-stretch self-manufactured by Teraoka Seiko
Dynamic packaging machine AW-3600, pre-stretch automatic made by Fujiki Kai
Packaging machine FP-38. [0003] The packaging mechanism of the pre-stretch automatic packaging machine is as follows.
Unwound from the film roll and cut to length
The transported film is reserved before the tray is pushed up.
Approximately 1. in the horizontal direction of the film (the width direction of the film roll)
It is stretched and stretched to 5 times (50% extension) length, and then
The tray with the package is pushed up by the film
You. The feature of this pre-stretch automatic packaging machine is that the tray
Before the film is pushed up, the film is about 1.5 times
In that it is pre-stretched to length.
The film width required by the up-and-down automatic packaging machine
Tray of the same size can be wrapped with about 2/3 width film
As a result, it has become possible to reduce the amount of film used. A film suitable for a push-up type automatic packaging machine and
Therefore, for example, in Japanese Patent Application Laid-Open No. 06-155676,
Propylene, styrene-butadiene block copolymer
Hydrogenated product, ethylene-vinyl acetate copolymer and / or
Or a mixture comprising an ethylene-α-olefin copolymer
It is made of resin, and vinyl acetate is formed on both sides of this core layer as inner and outer layers.
Polyolefin-based filter
Lum suggests. [0005] However, the above-mentioned proposals
When the proposed film is used for a pre-stretch automatic packaging machine,
When the film is pre-stretched
The film cannot be packed and cannot be wrapped.
Tearing along the flow direction).
Also, when the tray is pushed up on the film, about 1.5
The film, which was pre-stretched twice, thrusts up
Further extended by the tray
Since it is expanded to about twice (100% expansion),
System cannot be tightly packed due to loss of resilience
There was such a problem. In addition, presto about 1.5 times
If the tensile stress of the film when retched is too large
In case, the tray broke when pushed up
On the other hand, if the tensile stress is too small,
The film had problems such as wrinkles and looseness. Book
The purpose of the invention is transparency, flexibility, tear strength and resilience
Excellent heat-sealing capability, especially for pre-stretch
Polyolefin-based fill suitable for use in dynamic packaging machines
To provide a system. [0006] The present inventors have set forth the above object.
As a result of intensive research to solve the problem, pre-stretch
The film used for the automatic packaging machine
Tensile elasticity in the transverse direction of the film because it is stretched about 50% in advance
If the rate and tear strength are not in the specified range,
Make sure that the removal of the film and the tearing of the film are not
And found. Also, the tray sticks to the stretched film.
When lifted, this film can be about 100%
Up to 50% stretching in the horizontal direction of the film.
After specifying the value of the tensile stress, that is, the 50% tensile stress,
And the value of 100% tensile stress / 50% tensile stress is within a certain range.
If not, the tray may crack or wrinkle on the film
Without the loss of film resilience
I found that it should not. In addition, this 100% tensile stress
To keep the value of / 50% tensile stress in a specific range,
Stretch the film to the resin composition that forms the core layer of the film.
With a large increase in stress due to
Copolymer of pyrene and ethylene-propylene rubber
-Completed the present invention by finding that alloys should be added.
I let you. [0007] The food packaging film of the present invention is made of polypropylene.
Vinyl aromatic compound per 100 parts by weight of pyrene resin
5 to 45% by weight of a hydrogenated derivative of a copolymer of styrene and a conjugated diene
Parts by weight, 10 to 60 parts by weight of a copolymer of ethylene and octene and
Of propylene and ethylene-propylene rubber (EPR)
Resin obtained by mixing 10 to 60 parts by weight of copolymer alloy
The composition is used as a core layer, and both sides of the core layer are used as inner and outer layers.
3 layers of laminated layers of len-vinyl acetate copolymer
It is characterized by comprising. DETAILED DESCRIPTION OF THE INVENTION The above-mentioned main component of the core layer of the present invention
MFR (melt flow resin)
Shio) is 1 to 10g / 10 minutes (temperature 230 ° C, load 2.16kg)
Propylene homopolymer, propylene-ethylene copolymer,
Copolymerization of propylene with α-olefin having 4 to 10 carbon atoms
And amorphous polyolefins and crystalline polypropylene
Resin, etc., among which transparent and attractive
Amorphous polyolefin and crystallinity due to excellent crack strength
A mixed resin with polypropylene is preferred. This amorphous po
Mixed resin of polyolefin and crystalline polypropylene
Contains propylene and / or butene-1 component
Rate is 50% by weight (hereinafter referred to as wt%) or more.
Polyolefin 20-50 wt% and crystalline polypropylene 80-50
Those containing wt% are more preferred. Amorphous polyolefin
Is an amorphous α-olefin copolymer, for example,
For example, amorphous polypropylene or polybutene-1 or
Co-polymerization of propylene and butene-1 with other α-olefins
Combination or the like can be used. [0009] The amorphous polyolefin is contained in the mixed resin.
If the content is less than 20 wt%, crystalline polypropylene
High transparency and flexibility
And the tearing strength is low due to the strong orientation in the film.
There is a problem that the mixed resin
Melting point to 135 ° C or less, impairing heat sealability
Is not preferred. In addition, in amorphous polyolefin
Of the propylene and / or butene-1 component of
If it is less than 50 wt%, the compatibility with crystalline polypropylene is low.
It is not preferable because it falls. The above-mentioned crystalline polypropylene is mixed with
If the content in the resin is less than 50 wt%, the melting point of the mixed resin is 13
Degraded to 5 ° C or lower, impairing heat sealability
However, if it exceeds 80 wt%, crystalline polypropylene
Transparency and flexibility due to the strong expression of crystallinity
Not obtained, and the orientation in the film is increased to increase the tear strength.
It is not preferable because the degree is lowered. This crystalline polypropylene
Rene is preferably a propylene homopolymer or
Contains 30% by weight or less, preferably 1 to 25% by weight of a titanium component
Propylene-ethylene random copolymer or block
Copolymers. Ethylene content exceeds 30wt%
Melting point falls to 135 ° C or less, and heat sealability is impaired.
Is not preferred. [0011] Such a polypropylene resin is used for the core layer.
By blending it as a main component, the amorphous character
Excellent film transparency (haze) and low orientation
Excellent tear strength and heat sealing
A possible film is obtained. However, the polypropylene
When the lene-based resin is used alone, the tensile modulus
Surrounding (a range suitable for practical use) is too high. Ma
Also, the 50% tensile stress during film extension falls within a specific range
However, when it is stretched by more than 50%, it is plastically deformed and its resilience is lost.
Be done. The core layer contains the above-mentioned polypropylene resin and
In addition, for the purpose of reducing tensile modulus and imparting resilience,
Vinyl with MFR of 1-15g / 10min (temperature 230 ℃, load 2.16kg)
Of Hydrogenation of Copolymers of Aromatic Compounds and Conjugated Diene
Compound conductor. This vinyl aromatic compound and conjugated diene
The hydrogenated derivative of the copolymer with has rubber elasticity and elasticity
The deformation region exists over a wide range. Also, tensile elasticity
The rate is also low. This hydrogenated derivative is a polypropylene resin
5 to 45 parts by weight per 100 parts by weight, more preferably 10 to 45 parts by weight
40 parts by weight, but if less than 5 parts by weight, tensile modulus
Does not decrease to a specific range, elasticity is not added and resilience is
Inconveniences such as not being obtained occur. Conversely, over 45 parts by weight
Then, the orientation increases and the tear strength of the film decreases,
100% tensile stress / 50% tensile stress decreases,
Little increase in tensile stress due to elongation, too strong resilience
Problems such as peeling of the bottom seal and lowering of transparency
You. The vinyl aromatic compounds used include
Tylene is typical, and o-styrene, p-styrene
And α-methylstyrene. With conjugated dienes
Butadiene, isoprene, 1,3-pentadiene, etc.
No. These are appropriately combined to form a copolymer.
Is, for example, a styrene-butadiene diblock copolymer
Hydrogenated derivative (SEB) of styrene-butadiene
Hydrogenated derivative of Tylene triblock copolymer (SEB
S), hydrogen of styrene-isoprene diblock copolymer
Additive derivative (SEP) and styrene-isoprene-styrene
Hydrogenated derivatives of rentriblock copolymers (SEPS), etc.
Is mentioned. Among them, SEBS and SEPS are preferable, and more
Preferably it is SEBS. In addition to the block copolymer,
May be a random copolymer. Furthermore, conjugate die
The bonding mode of butane can be either butadiene or isoprene.
At least a 1,4-bond or a 1,2-bond. Hydrogenation is common
At least 80 wt% of olefinic double bonds in the active diene
Above, more preferably 90% by weight or more hydrogenated
It is. If it is less than 80 wt%, it is easily deteriorated by heat during molding, and it is crosslinked
It is not preferable because a reaction occurs. Styrene content in these hydrogenated derivatives
Is preferably 10 to 40 wt%, and if less than 10 wt%, the tensile stress
And the 50% tensile stress does not reach the specified range.
Insufficient bubble stability during inflation molding
On the contrary, if it exceeds 40 wt%, the MFR becomes extremely small.
Melting and kneading during molding become insufficient,
It is not preferable because it lowers. In addition, the hydrogenated derivative
Has a glass transition temperature of -30 ° C or less,
Reduction of tensile modulus and resilience without impairing cold resistance
A grant is achieved. The above-mentioned vinyl composition is added to the resin composition constituting the core layer.
Hydrogenation induction of copolymers of aromatic compounds and conjugated dienes
By blending the body, the elastic deformation area becomes wider
Improved resilience, tensile modulus falls to a specific range
And the like, but this hydrogenated derivative is
Orientation in the film due to linear resin
Easily along the longitudinal direction (forming direction) of the drum. sand
That is, in the transverse direction of the film (perpendicular to the film forming direction)
In the direction). In the present invention, the resin composition constituting the core layer
In addition, to improve the tear strength, the MFR is 0.1 to 8 g / 10
Minute (temperature 190 ° C, load 2.16kg) ethylene and octene
Is blended. This copolymer has long chain branches
Resin, it is entangled with other resins to form a network structure.
Can be achieved. This copolymer is polypropylene-based
10 to 60 parts by weight, more preferably 100 parts by weight of resin
15 to 55 parts by weight, but if the amount is less than 10 parts by weight
The orientation cannot be weakened and the tear strength does not improve. On the contrary, 60
If the amount exceeds 50%, the 50% tensile stress during film elongation
Lower than the box. In addition, ethylene used in the present invention
The density of the copolymer with octene is 0.860-0.890 g / cm ^Three of
A range is preferred. 0.860 g / cm density ^Three Less than
Not practical. Because 0.860 g / cm ^Three Is ethylene
Is the density when the crystallinity of
You. Conversely, the density is 0.890 g / cm ^Three If it exceeds
Since the degree of crystallinity increases, the orientation of the copolymer itself increases.
The tear strength does not improve. This copolymer is obtained by converting octene copolymer to 20
A copolymer of ethylene and octene containing up to 30 wt%
Linear low density manufactured using a single site catalyst.
The degree is polyethylene. Octene copolymer content
If less than 20wt%, the density is 0.890g / cm ^Three Not less, opposite
0.860 g / cm even if it exceeds 30 wt% ^Three Only fall to
Absent. The resin composition that constitutes the core layer contains
Tear by incorporating a copolymer of octene and octene.
Strength can be improved. Further, the resin composition constituting the core layer includes:
Purpose of keeping 100% tensile stress / 50% tensile stress in a specific range
And MFR is 0.1-8g / 10min (temperature 230 ℃, load 2.16kg)
Copolymerization of propylene with ethylene-propylene rubber
Rimmer alloy is based on 100 parts by weight of polypropylene resin.
10 to 60 parts by weight, more preferably 15 to 55 parts by weight
It is. This copolymer alloy has a tensile stress associated with elongation.
, And the resilience in the high elongation range is excellent. This
If the blending amount is less than 10 parts by weight,
Small increase in tensile stress due to tension, 100% tensile stress / 50
% Tensile stress is below the specified range. Conversely, over 50 parts by weight
The stress increase due to stretching is too large
Force / 50% tensile stress exceeds the specified range. This co-weight
Polymer alloys belong to olefin-based elastomers
Propylene is ethylene-propylene rubber
Polymer by direct polymerization in the polymerization stage with (EPR)
Because it becomes an alloy, the EPR component is less than 1 μm in size.
Microphase-separated poly uniformly and finely dispersed in propylene
It is a mar-alloy and does not impair transparency. Copolymerization
The EPR content in the polymer alloy is preferably 50 to 90 wt%.
If the content is less than 50 wt%, the flexibility is reduced due to the reduction of the rubber component.
On the contrary, if it exceeds 90 wt%, propylene
Due to the reduction of components, the main component is polypropylene-based resin.
This is not preferred because the compatibility decreases. The above copolymerized poly
EPR, an olefinic elastomer other than mar-alloy
Is not suitable for use in the present invention. For copolymerized polymer alloy
When EPR is added to the resin composition instead, EPR is 10 μm
Because it is dispersed in the resin composition in a size of about, transparency
It will be significantly reduced. That is, it can be used in the present invention.
Olefin elastomers are
Only Roy. The above resin composition constituting the core layer is further added to
, Monoglycerin fatty acid ester, polyglycerin fat
Fatty acid esters, sorbitan fatty acid esters, and poly
Add surfactant such as oxyethylene alkyl ether
You can also. Specific examples of these include
Serine laurate, monoglycerin oleate, polyglycol
Serine laurate, polyglycerin oleate, sorbita
Laurate, sorbitan oleate, polyoxyethylene
And lauryl ether. Also during molding
As a radical scavenger to prevent thermal oxidation degradation of
Functional phenolic antioxidants and peroxide decomposers
May be added. Further
The ethylene-vinyl acetate copolymer used in the inner and outer layers,
Add low density polyethylene and ultra low density polyethylene etc.
Can be added. The film of the present invention is made of a conventional polyvinyl chloride.
Of polypropylene-based resin in place of
Imparts high transparency and tear strength to the film and heat seals
Is made possible. However, the poly used in the present invention
Propylene resin has a very high tensile modulus and yield point.
And plastically deform. For this reason, the core layer is made of polypropylene
Pre-stretch automatic packaging of a film consisting only of resin
When used on a machine, the elasticity of the film increases when the film is stretched.
The film may come off from the film presser
is there. Also, even if the film is stretched without falling off,
If the film stretch exceeds 50%, it will be plastically deformed.
No resilience is obtained because the film is not taut. Therefore, the vinyl aromatic compound and the conjugated die
A hydrogenated derivative of a copolymer with
To give the film resilience due to rubber elasticity
The tensile modulus is lowered. However, the hydrogenation
Since the derivative is a linear resin, the molecule
Orientation along the direction and easy to tear. As a countermeasure,
Increases network structure with chain branching and good entanglement with other molecules
Compounding ethylene and octene copolymer
Can weaken the apparent orientation of the molecules in the film.
And the tear strength is improved. In addition, to stretch
The increase in stress is large and the resilience in the high elongation range is high.
Copolymer of pyrene and ethylene-propylene rubber
100% tensile stress / 50% tensile response by alloying
Pre-stretch automatic with force within a specific range
Appropriate packaging for the packaging machine is given. [0022] In this manner, in the film lateral direction (fill
50% tensile stress in the direction perpendicular to the mold forming direction), 100%
Tensile stress / 50% tensile stress, tensile modulus and tear strength
Satisfaction, transparency, flexibility, tear strength, restoration
, Heat sealing, and pre-stretch automatic packaging machine
Is given a packaging suitability. The film of the present invention comprises the above-mentioned core
On both sides of the layer, the MFR is 0.5 to 10 g / 10 min.
Layer made of ethylene-vinyl acetate copolymer weighing 2.16 kg)
Are laminated. Ethylene-vinyl acetate used
The copolymer preferably has a vinyl acetate content of 5 to 20% by weight.
Less than 5 wt%, self-adhesive
Property cannot be obtained. Conversely, if it exceeds 20% by weight,
It is not preferable because it becomes too strong and the suitability for packaging is reduced.
The inner and outer layers provided on both sides of the core layer are the above-mentioned ethylene-acetic acid.
The core layer is added to a resin composition containing a vinyl copolymer as a main component.
You may add the same surfactant as the one added to
In addition, by adding a surfactant,
Self-adhesive without impairing the gloss and transparency of the multilayer film
Properties, slipperiness and anti-fogging properties can be improved. Also low
High density polyethylene, ultra low density polyethylene, and even straight
A chain low-density polyethylene or the like can be added. The film of the present invention has a thickness of 8 to 25 μm,
The thickness of the core layer is 3 to 20 μm, provided on both sides of the core layer.
The inner and outer layers each have a thickness of at least 1 μm.
You. When the thickness of the core layer is less than 3 μm, physical properties as the core layer are generated.
Not exhibited, plasticity of ethylene-vinyl acetate copolymer
Deformation develops and does not provide restorability. In addition, ethylene
-Tear strength decreases due to orientation of vinyl acetate copolymer
You. Further, the heat seal temperature range on the high temperature side decreases.
Conversely, if the thickness of the core layer exceeds
Heat sealability is reduced due to thinning of the nyl copolymer layer
I do. In addition, self-adhesiveness due to the increased rubber elasticity of the core layer
Is inhibited. The film having the above structure according to the present invention is excellent.
But with hand-wrapping and pre-stretch automatic packaging
Machine, push-up type automatic packaging machine and pillow type automatic packaging machine
A film that is a measure of the flexibility of a film suitable for use.
50% tensile stress (JIS K 7113 compliant) in the lateral direction of LUM is 4.00 ~
9.00 N / mm ^Two , More preferably 4.50 to 8.50 N / mm ^Two In the range
is there. This value is 4.00 N / mm ^Two If less than the film will be soft
The tension of the film after wrapping is weak.
If the mounted product steps down at the time of display, the film
It sags under weight and wrinkles remain. Opposition
9.00 N / mm ^Two If it exceeds, it will be a hard and hard to stretch film
This causes the tray to break during packaging. The film of the present invention can be used for pre-stretching
100% tensile stress, which is a measure of packaging suitability for packaging machines
50% tensile stress (JIS K 7113 compliant) 1.05 to 1.40, better
More preferably, it is in the range of 1.10 to 1.35,
Has high resilience. If the stress ratio is less than 1.05,
Pre-stretching with little increase in tensile stress due to tension
When using an automatic wrapping machine, tension may be applied to the wrapped film.
I can't get it. Conversely, if it exceeds 1.40, the elasticity is too strong
-When it is pushed up, there is a problem that it breaks
You. The resilience and prestress of the film of the present invention
フ ィ ル Fill as a measure of pre-stretchability in automatic packaging machines
Tensile modulus in the transverse direction (based on JIS K 7113) is 50.00-
110.00 N / mm ^Two , More preferably 55.00 to 105.00 N / mm ^Two of
In range. 50.00 N / mm ^Two If less than 50% tensile stress is the lower limit
Value, and the film after packaging due to low elasticity
Does not have sufficient restorability. 110.00 N / mm ^Two To
If it exceeds, the tray becomes deformed due to too high elasticity and resilience becomes too strong
Or when used in a pre-stretch automatic packaging machine
The film is too elastic during pre-stretching
The film may come off from the lum presser. Further
In addition, it also inhibits self-adhesiveness and heat sealability. Film orientation and pre-stretch automatic wrapping
Lateral direction of film as a measure of pre-stretching property on loading equipment
Has a tear strength (according to JIS K 6732) of 55.00 to 90.00 N / mm
^Two , More preferably 60.00 to 85.00 N / mm ^Two In the range
You. 55.00 N / mm ^Two Less than the length of the film
Directivity is too strong and used in pre-stretch automatic packaging machine
If so, the film will stretch
Torn. Also, in hand wrapping, grabbed the film
The film tears due to the tensile stress on the fingertip.
U. 90.00 N / mm on the contrary ^Two Exceeds the horizontal orientation of the film.
Since the directionality is enhanced, the elasticity in the longitudinal direction of the film is
Wrinkles remain on the film after mounting. EXAMPLES The film of the present invention is a multilayer inflation film.
It is manufactured by the method. That is, using three extruders
Place a molten resin film from a three-layer inflation die
Co-extrude to obtain a constant layer thickness. Then, the solution
Blow ratio while cooling the molten resin film with cooling air
Blow up so that it is in the range of 3-10. Then pull
Fold it with a pinch roll inside
It is wound up to a predetermined thickness with a width of 35 cm by a winder. At this time,
The blow ratio is preferably in the range of 3 to 10. Blow ratio less than 3
In, the resin is oriented along the molding direction (film longitudinal direction)
Therefore, a predetermined tear strength cannot be obtained. Conversely, blow ratio
Exceeds 10, the bubble during blow-up becomes unstable.
Film cannot be formed. Each physical property of the obtained film was determined by the following method.
Was measured and evaluated. 1. MFR: Measured according to ASTM-D1238. 2. Density: Measured according to JIS K7112. 3. Glass transition temperature: measured according to JIS K7121. 4. Transparency (haze%); film according to JIS K7105
It was measured on one sheet. If this value is 2.0% or less, it is practically good.
Suitable. 5. 50% tensile stress, 100% tensile stress; according to JIS K6732
At a tensile speed of 200 m / min. 6. Tensile modulus: 5 m / tensile speed according to JIS K7113
Measured in minutes. 7. Tear strength: 200 m / min tensile speed according to JIS K6732
Was measured. 8. Restorability; 30g iron ball (diameter 2c)
m), press it in 2 cm and remove it.
“〇” indicates that the lumps and wrinkles are restored within 10 seconds
(Good), and the case of no restoration is evaluated as “x” (bad).
Was. 9. Heat sealability: 200g weight
PSP Tray SK-20 (Chuo Kagaku Co., trade name) handler
Wrap it on a hot plate with a surface temperature of 110 ° C.
Let it heat seal for 2 seconds and check the situation
Was. The film fuses where multiple layers of film overlap
In addition, there is no perforation because there is no melting
If the seal was successful, it is marked as “〇”.
The case was evaluated as "x" (poor). 10. Suitable for pre-stretch packaging machine; Teraoka Seiko
Using the company's pre-stretch automatic packaging machine AW-3600, 20
Pack and pack 100 packs of SK-20 tray with 0g weight
The mounting condition was confirmed. a. Pre-stretch property; film is pre-stretched
Film does not fall out of the film holder and does not tear
Is set to “た”, and “×” is set for two or more misses.
If the film tears more than once, it is evaluated as "xx"
Was. b. Tray crack; 0 pack out of 100 packs
Then, one or more packs were evaluated as “×”. c. Wrinkles, loosening; within 2 packs out of 100 packs, "〇"
And three or more packs were evaluated as “×”. d. Sealability: Peeling or perforation of bottom seal is 100 packs
Of the packs, "〇" is set for 2 packs or less and "x" for 3 packs or more.
Was evaluated. e. Torn; 2 packs out of 100 packs are marked with "〇",
Three or more packs were evaluated as "x". 11. Suitable for hand wrapping; use hand wrapper
And pack 50 packs of SK-20 tray with 200g weight
To check the packaging. a. Wrinkles, loosening; within 50 packs, 2 packs or less
Then, three or more packs were evaluated as “×”. b. Sealability: 50 packs with bottom seal peeling and perforation
Of the packs, "〇" is set for 2 packs or less and "x" for 3 packs or more.
Was evaluated. c. Torn; Within 2 packs of 50 packs, "〇", 3
A pack or more was evaluated as "x". In this way, the composition groups shown in the following table
Examples (Tables)
1) A film of Comparative Example (Table 2) was produced. Of the embodiment
Table 3 shows the results, and Table 4 shows the results of the comparative example. The table
3. In Table 4, MD indicates the film forming direction, and TD indicates the film forming direction.
The direction perpendicular to the forming direction of the lum is shown. Obvious from the table
As described above, all the films of the examples are shown in Table 3.
It had excellent characteristics. In contrast, the comparative example
The film was inferior to the film of the present invention. [Table 1] [Table 2] [Table 3] [Table 4] The film of the present invention can be used for hand-wrapping,
Letch automatic packaging machine, push-up automatic packaging machine and pillow
Suitable for use in automatic packaging such as automatic packaging machines
Excellent in transparency, flexibility and resilience,
Especially for tensile modulus, tear strength and elongation
The resulting increase in tensile stress falls within a specific range suitable for practical use.
Makes it suitable for use with pre-stretch automatic packaging machines.
Has proper packaging suitability.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Suzuki 1-406-1, Yoshino-cho, Omiya-shi, Saitama Shin-Etsu Polymer Co., Ltd. Tokyo plant (72) Inventor Eiji Kimura 1-406-1, Yoshino-cho, Omiya-shi, Saitama Shin-Etsu Polymer Co., Ltd. Tokyo plant (56) References JP-A-11-170446 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 C08J 5 / 18 C08L 23/00-23/36

Claims (1)

(57) [Claims 1] 5-45 parts by weight of a hydrogenated derivative of a copolymer of a vinyl aromatic compound and a conjugated diene, 100 parts by weight of a polypropylene resin, ethylene and octene A resin composition obtained by mixing 10 to 60 parts by weight of a copolymer and 10 to 60 parts by weight of a copolymer alloy of propylene and ethylene-propylene rubber is used as a core layer, and ethylene is used as an inner and outer layer on both sides of the core layer. -A food packaging film comprising three layers in which a layer made of a vinyl acetate copolymer is laminated.