JP2002327074A - Stretchable film having excellent low temperature property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stretchable film, composed of chlorine-free resin, having wrapping property of ordinary stretchable film, and usable for wrapping of low-temperature distribution foods. SOLUTION: The stretchable film excellent in low-temperature property is obtained by arranging tanδ of film to 0.2 or above, wherein tanδ is measured under frequency of 10 Hz and at -20 deg.C by dynamic viscoelasticity measurement. For example, this film is composed of a mixed composition with a specific ratio, of a linear low density polyethylene-based resin and a high-pressure processed polyethylene having different density to each other. This film has good wrapping property also at ambient temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch film used for packaging foods, and more particularly to a stretch film used for packaging low-temperature foods. The units (% and parts) of the composition used in the present invention are expressed on a mass basis unless otherwise specified.

[0002]

2. Description of the Related Art In recent years, with the progress and spread of refrigeration technology for foods, low-temperature distribution foods have been increasing. Here, the low-temperature preserved food refers to a food that is distributed and preserved at a low temperature (5 ° C. to −20 ° C.) such as foods such as fruits and vegetables, fresh fish, meat, and the like, and processed processed foods.

Conventionally, stretch films for so-called pre-packs for business use, in which foods such as fruits and vegetables, fresh fish, meat, etc. are overlapped directly or on polystyrene paper (PSP), are mainly made of polyvinyl chloride (hereinafter referred to as “PVC”). ") Systems have been used. This is because the unwinding of the film is smooth and easy to stretch, it does not break when it is stretched, it adheres tightly when the films are stacked, and the film fits well at the bottom of the tray, and the packaging workability and finish are beautiful without wrinkles. It has excellent suitability for packaging, and recoverability that returns to the original state even after applying deformation such as pressing the film after packing with a finger.It also has excellent properties such as the film overlap at the bottom of the tray remains in close contact during transportation and display, and it is difficult to peel off. This is because the characteristics are recognized by both sellers and consumers.

[0004] However, a general PVC-based stretch film cannot be used for packaging low-temperature distribution foods because the strength of the film is remarkably reduced at -10 ° C or lower. For this reason, a special PVC-based stretch film in which an additive having excellent low-temperature characteristics is added or a film thickness is increased is used for packaging of low-temperature distribution food. Therefore, in packaging using a stretch film, it is necessary to use the above two types of PVC-based stretch films by switching each time after grasping the distribution temperature of the food, which is the content. There has been a demand for a stretch film that does not require switching.

[0005] On the other hand, recently, there has been raised a problem that hydrogen chloride gas generated at the time of incineration of a PVC stretch film and elution of a contained plasticizer are caused. Therefore, an olefin-based stretch film is being studied as a substitute for PVC.

JP-A-9-165492 discloses that at least one layer containing a resin which is a copolymer of a vinyl aromatic compound and a conjugated diene or a hydrogenated derivative thereof and has a glass transition temperature of -20 ° C. or higher is provided. Storage elastic modulus (E ′) measured at a frequency of 10 Hz and a temperature of 20 ° C. by dynamic viscoelasticity measurement from 5.0 × 10 ⁷ to 5.0 × 10 ⁸ N / m.
^2. An olefin film characterized by tan δ in the range of 0.2 to 0.8 has been proposed. At a temperature near normal temperature (20 ° C.), this film has a packaging property and film strength close to those of a PVC stretch film. However, at 0 ° C. or lower, tan δ becomes extremely small, and when used for packaging the above-mentioned low-temperature-distributed food, the film may be torn during distribution.

[0007]

DISCLOSURE OF THE INVENTION The present invention relates to a stretch film which is made of a resin containing no chlorine, has the suitability for ordinary stretch film packaging, and can be suitably used for packaging low-temperature-distributed foods. To provide.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have been able to obtain a non-PVC-based stretch film which has overcome the above-mentioned problems. A stretch film made of a resin not containing chlorine and having a loss tangent (tan δ) of 0.2 or more measured at a frequency of 10 Hz and a temperature of −20 ° C. by dynamic viscoelasticity measurement, preferably, a density of 905 kg / m Linear low-density polyethylene (A) exceeding ³ , density 905
kg / m ³ or less of a linear low-density polyethylene (B) and a high-pressure polyethylene (C),
When the sum of (B) and (C) is 100%, (A)
80-10%, (B) 10-40% and (C) 10-5
It is a stretch film having a resin composition of 0%.
Preferably, the total of the resins (A), (B) and (C) is 1
In contrast to component (D), at least one selected from the group consisting of 0.5 to 10 parts of petroleum resin, terpene, terpene derivative, rosin, rosin derivative and hydrogenated product thereof, polybutene, liquid polybutadiene and liquid polyisobutylene as component (D) Is a stretch film to which is added. Also, the above film is
Films produced by the T-die method are preferred. Further, the above film is suitably used as a stretch film for hand wrap.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The stretch film of the present invention is made of a resin substantially free of chlorine. The present inventors have determined that the film of the present invention has a frequency of 10 Hz,
By setting tan δ measured at 20 ° C. to 0.2 or more, it was found that when this film was used for packaging of low-temperature distribution food, the film of the packaged product would not be torn during distribution and storage. Invented the invention.

If the tan δ of the film measured at −20 ° C. is less than 0.2, the film becomes hard and brittle at low temperatures, so that an impact force such as dropping is applied to the package at the time of low temperature distribution. In this case, the film often tears. Also, peeling is likely to occur at the film overlapping portion at the bottom of the tray of the packaged product due to vibration or the like during distribution. This ta
The nδ value may be 0.2 or more as described above, but is generally 0.4 or less from the characteristics of a resin that can be used as a raw material.

It is important that the stretch film of the present invention has the above-mentioned low-temperature characteristics.
At the same time, it is necessary to satisfy the suitability for packaging as a stretch film at normal temperature.

In general, there are stretch films for automatic wrapping (hereinafter referred to as "automatic") and hand wrapping (hereinafter referred to as "hand"), and the automatic film uses an automatic wrapping machine. For example, the film is fed out by a transport belt, and a saw-like cutting blade provided between the transport belts is protruded and perforated to cut the film while transporting the film. Thereafter, the central portion of the cut film is pushed up and stretched by a tray on which food is placed, and the film is folded and overlapped by a folding plate. For this reason, cut transportability, stretchability, not torn when the film is stretched or folded, and adhesiveness that is not easily peeled after the film is stacked are required.

On the other hand, a hand film is manually formed by using a hand wrapper. For example, the both sides of a film placed on a pay-out roll are grasped by hand, and a length necessary to cover a tray on which food is placed is provided. Unwind the film and cut the film with a hot wire. Next, the covered film is stretched in the horizontal direction, and the film is packaged such that the films are overlapped with each other at the bottom of the tray. For this reason, characteristics different from those of the film for automatic use are required, for example, the film can be smoothly fed, the operator can easily stretch the film, the film does not break when stretched, and the film is not easily peeled off.

The film of the present invention having excellent low-temperature properties and excellent packaging suitability, for example, has a density of 90
A linear low-density polyethylene (A) exceeding 5 kg / m ³ , a linear low-density polyethylene (B) having a density of 905 kg / m ³ or less, and a high-pressure polyethylene (C); 100% of the sum of (B) and (C)
(A) 80 to 10%, (B) 10 to 40%
And (C) a composition comprising 10 to 50%.
In the case of this composition, when a low-density linear low-density polyethylene is used among the above resin components, -2
The value of tan δ at 0 ° C. increases, and the low-temperature characteristics are improved. On the other hand, it is necessary to maintain the packaging suitability at room temperature as a stretch film and the physical properties of the film at a favorable level. as a method for obtaining a satisfactory film density and 0.905kg / m ³ or more of the component (a), density 0.905kg / m ³ or less of the component (B), by setting the density and the amount of properly Thereby, a stretch film excellent in low-temperature characteristics and excellent in suitability for packaging can be obtained.

The linear low-density polyethylene (A) used in the present invention preferably has a density exceeding 905 kg / m ³ . Among them, a copolymer of ethylene and an α-olefin is preferred. As the α-olefin, propylene, butene-1, hexene-1, 4-methylpentene-1, hexene-1, heptene-1, octene-1, nonene-
1, decene-1, dodecene-1 and the like, preferably,
The α-olefin has 6 to 8 carbon atoms. Carbon number 6 ~
The film of the present invention using the ethylene / α-olefin copolymer of No. 8 has a high film impact strength,
It is difficult to tear when piercing the film. As the above-mentioned linear low-density polyethylene (A), a commercially available product can be used.

The linear low-density polyethylene (A) is
80 for a total of 100% of (A), (B) and (C)
A composition of 10% to 10% is preferred. If it exceeds 80%, the tensile strength of the film becomes high, and the film becomes hard to stretch and hard to pack. On the other hand, if it is less than 10%, the tensile strength of the film is low, and the film tends to be broken during stretching.

The linear low-density polyethylene (B) used in the present invention has a density of preferably 905 kg / m ³ or less, more preferably 880-905 kg / m ³ . Among them, ethylene and α-olefin have 3 carbon atoms.
To 12 are preferred. Specific examples of the α-olefin include propylene, butene-1, hexene-1, 4
-Methylpentene-1, hexene-1, heptene-1,
Octene-1, nonene-1, decene-1, dodecene-1
And the like. By adding the component (B), elongation and adhesiveness of the film at the time of packaging can be adjusted. When the density exceeds 905 kg / m ³ , these adjustment effects become small. On the other hand, if it is less than 880 kg / m ³ , the stiffness of the film becomes weak. Further, as these linear low-density polyethylenes (B), commercially available products can be used.

The composition of the linear low-density polyethylene (B) is preferably from 10 to 40%. If it is less than 10%, the adhesiveness of the film becomes weak, and the film is unwound too much. Further, a failure phenomenon in which the film at the bottom of the tray is overlapped with each other and peeled off during distribution is likely to occur. Further, the film becomes hard and difficult to stretch. On the other hand, if it exceeds 40%, the adhesiveness of the film becomes too strong, so that when the film is formed into a roll, the film sticks and the film does not come off, so-called "blocking" occurs, and it tends to be difficult to use the film when it is used. In some cases, it will not be possible to feed out.

In the present invention, the component (B) is preferably in a range not exceeding the addition amount of the component (A) in order to give the film a firmness.

The high-pressure polyethylene (C) of the present invention is produced by a high-pressure radical polymerization method, and a commercially available product can be used. The addition amount of (C) is 10 to
50% is preferred. If it is less than 10%, the melt tension will be low and the film formation will be difficult to stabilize. 5
If it exceeds 0%, the film strength is reduced, and the film tends to be broken during stretching.

The present invention relates to a commercially available C5 as a component (D).
(Aliphatic) -based, C9 (aromatic) -based, C5C9-based or cyclopentadiene-based petroleum resins and their hydrogenated products, or terpenes, terpene derivatives, and their hydrogenated products, rosins, rosin derivatives and It is preferable to add at least one of these hydrogenated derivatives, polybutene, liquid polybutadiene, and liquid polyisobutylene. Also, a plurality of components selected from the above can be added. By adding these, the strength at the time of stretching the film and the adhesiveness of the film can be increased. The added amount of the component (D) is a total of 100 of (A), (B) and (C).
Is preferably 0.5 to 10 parts. If the amount is less than 0.5 part, the above effect is not recognized. On the other hand, if it exceeds 10 parts, the adhesiveness of the film becomes too strong to cause blocking, and the adhesive tends to bleed on the film surface with the lapse of time, resulting in a decrease in transparency.

It is preferable to add an antifogging agent to the stretch film of the present invention. The amount added is 1 to 5 parts, preferably 1.5 to 4 parts. Examples of the antifogging agent include surfactants conforming to the PL standard (list of food additives), such as glycerin fatty acid (C8-22) ester, sorbitan fatty acid (C8-22) ester, propylene glycol fatty acid (C8-22) ester, Sugar fatty acids (C8-2
2) esters, citric acid mono (di or tri) stearic acid esters, pentaerythritol fatty acids (C8-2
2) Ester, polyglycerin fatty acid (C8-22) ester, polyoxyethylene (20) glycerin fatty acid (C8-22) ester, polyethylene glycol fatty acid (C8-22) ester, polypropylene glycol fatty acid (C8-22) ester, poly Oxyethylene (9.5) dodecyl ether, polyoxyethylene (4
-14.30-50) alkyl (C4, 9, 12) phenyl ether, condensation product of N, N-bis (2) -hydroxyethyl fatty acid (C12-18) with diethanolamine, polyoxypropylene polyoxyethylene block Polymer, polyethylene glycol (molecular weight 20
0-9500), polypropylene glycol and the like.

If necessary, a stabilizer, an antistatic agent, and a processability improver can be added to the stretch film of the present invention. For example, 2,6-di-t-butyl-p-cresol (BHT), tetrakis [methylene-3- (3,
5-di-tbutyl-4-hydroxyphenyl) propionate] methane, a phenolic stabilizer represented by n-octadecyl-3- (4′-hydroxy-3,5′-di-t-butylphenyl) propionate, Screw (2, 4
Phosphite-based stabilizers represented by -di-t-butylphenyl) pentaerythritol diphosphite and tris (2,4-di-t-butylphenyl) phosphite; glycerin esters of fatty acids having 8 to 22 carbon atoms And sorbitan acid esters and polyethylene glycol esters, and processability improvers represented by fatty acid metal salts such as calcium stearate.

The thickness of the stretch film of the present invention is in the range used as a normal stretch film, ie, 5
To 20 μm, preferably 8 to 15 μm. 5
When the thickness is smaller than μm, the film is easily broken at the time of film stretching. On the other hand, if the thickness is more than 20 μm, the film becomes difficult to stretch.

As a method for producing the stretch film of the present invention, a known method can be used, but a T-die method is preferable. The T-die method, compared to the inflation method,
Since the molten resin can be rapidly cooled by the cooling roll, the crystallinity of the film can be suppressed, and the transparency can be improved. Further, the film thickness accuracy is high, and the production speed can be increased as compared with the inflation method.

In the stretch film of the present invention, since scraps such as ears generated during film formation do not contain components other than the components used, generation of gel and the like, transparency of the film, Scrap can be returned to the raw material system of the film forming line without any problem such as a decrease in strength.

The stretch film of the present invention can be used for manual packaging using a handler. The film of the present invention can be smoothly wrapped, easily stretched by an operator, does not break when stretched, and can be efficiently packaged because the film is not easily peeled.

[0028]

The present invention will be described in more detail with reference to the following examples. The properties and packaging suitability of the raw material resin and the stretch film were measured and evaluated by the following methods.

1) Density The density of the raw material resin was measured according to JIS K6760. 2) Melt flow rate (MFR) According to JIS K6760, 190 ° C, load 21.
The MFR of the raw resin was measured under the condition of 18N. 3) Transparency (Haze%) The transparency of the film was measured according to ASTM-D1003. 4) tan δ Using a viscoelastic analyzer RSA2 manufactured by Rheometrics Co., Ltd., the temperature was changed at a vibration frequency of 10 Hz in the width direction of the film, and a measurement at −20 ° C. was obtained. 5) Suitability for automatic packaging Using a film having a width of 350 mm, a PSP tray (length 200 x width 150 x height 25 mm) is packaged at room temperature by an automatic packaging machine (AW-2600JrPE manufactured by Teraoka Seiko Co., Ltd.) Based on the criterion shown in No. 3, the film was evaluated for cut transportability, packaging condition width, tear, and adhesiveness. 6) Suitability for hand wrap Using a 300 mm wide film, a hand wrapper (AR
C (POLYWRAPPER40) and package the PSP tray (length 200 × width 150 × height 25 mm) at room temperature, and based on the criteria shown in Table 3, the film can be unwound, stretched, torn, broken, and tacky. The wrinkles at the time of finishing the packaging were evaluated. 7) Low temperature drop strength PSP tray (length 200 x width 150 x height 25mm)
The tray is wrapped with a 300 mm wide film using the above handler. A total of 24 pieces of this packaged product in a stack of 6 are placed in a cardboard box (length 500 mm × width 330 mm × height 160 m).
m) and stored in an environmental tester at 0 ° C. and −20 ° C. for 24 hours, respectively, and then the cardboard box was dropped horizontally on a concrete floor from a height of 1 m to confirm the number of film breaks.

Example 1 As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 907 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 3.3) ) 50%, having a density of 900 kg / m ³ as a linear low density polyethylene (B);
25% ethylene / α-olefin copolymer (MFR = 2.0) having 4 carbon atoms and a density of 92
4 kg / m ³ high pressure method polyethylene (C) (MFR =
2.0) A composition prepared by adding 1.5 parts of diglycerin laurate as an anti-fogging agent to 25% by a T-die method to a thickness of 11%.
A μm film was prepared.

The film was prepared by dry blending (A), (B) and (C), using a full flight screw (L / D = 28) with a 65 mm single screw extruder manufactured by Toshiba Machine Co., Ltd., and a die width of 550 mm. Using a T-die with a die lip of 0.7 mm, a set temperature of 180 to 230 ° C and a take-up speed of 60
m / min. In addition, the following Examples 2 to 6 and Comparative Example 2
-6 also produced films under the same conditions.

Example 2 As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 907 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 3.3) ) 50%, having a density of 900 kg / m ³ as a linear low density polyethylene (B);
25% ethylene / α-olefin copolymer (MFR = 2.0) having 4 carbon atoms and a density of 92
4 kg / m ³ high pressure method polyethylene (C) (MFR =
2.0) A composition prepared by adding 25% of a hydrogenated petroleum resin (softening point of 125 ° C.) as a component (D) and 2.5 parts of diglycerin laurate as an antifogging agent was used. A film having a thickness of 11 μm was prepared by a die method.

Example 3 As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 907 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 3.3) ) 35%, having a density of 900 kg / m ³ as a linear low-density polyethylene (B);
20% ethylene / α-olefin copolymer having 4 carbon atoms (MFR = 2.0) and a density of 92
4 kg / m ³ high pressure method polyethylene (C) (MFR =
2.0) A composition prepared by adding 45% of a hydrogenated petroleum resin (softening point: 125 ° C.) as a component (D) and 1.5 parts of diglycerin laurate as an antifogging agent was used. A film having a thickness of 11 μm was prepared by a die method.

Example 4 As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 910 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 2.1) ) 65%, having a density of 900 kg / m ³ as a linear low density polyethylene (B);
10% ethylene / α-olefin copolymer having 4 carbon atoms (MFR = 2.0) and a density of 92
4 kg / m ³ high pressure method polyethylene (C) (MFR =
2.0) A composition prepared by adding 25% of a hydrogenated petroleum resin (softening point of 125 ° C.) as a component (D) and 2.5 parts of diglycerin laurate as an antifogging agent was used. A film having a thickness of 11 μm was prepared by a die method.

Example 5 As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 910 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 2.1) ) 50%, having a density of 890 kg / m ³ as a linear low density polyethylene (B);
25% ethylene / α-olefin copolymer (MFR = 4.0) having 4 carbon atoms and a density of 92
4 kg / m ³ high pressure method polyethylene (C) (MFR =
2.0) A composition prepared by adding 25% of a hydrogenated petroleum resin (softening point of 125 ° C.) as a component (D) and 2.5 parts of diglycerin laurate as an antifogging agent was used. A film having a thickness of 11 μm was prepared by a die method.

Example 6 As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 913 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 2.0) ) 50%, having a density of 890 kg / m ³ as a linear low density polyethylene (B);
25% ethylene / α-olefin copolymer (MFR = 4.0) having 4 carbon atoms and a density of 92
4 kg / m ³ high pressure method polyethylene (C) (MFR =
2.0) A composition prepared by adding 25% of a hydrogenated petroleum resin (softening point of 125 ° C.) as a component (D) and 2.5 parts of diglycerin laurate as an antifogging agent was used. A film having a thickness of 11 μm was prepared by a die method.

Table 1 shows the ratios and densities of the raw materials used in the films of these examples, the tan δ of the films, and the evaluation results of the packaging property and the low temperature drop.

[0038]

[Table 1]

COMPARATIVE EXAMPLE 1 70% of a hydrogenated derivative of a triblock copolymer of styrene-isoprene-styrene composed of 20% of styrene and 80% of polyisoprene having a 3,4-bond ratio of 55%, and hydrogenated petroleum resin 30 % Of an intermediate layer, 100 parts of an ethylene-vinyl acetate copolymer (vinyl acetate content: 15%, MFR = 2.0) and 3.0 parts of diglycerin monooleate as an antifogging agent were added to the front and back layers. A film having a total thickness of 15 μm was prepared by co-extrusion inflation molding so as to have a thickness of 5 μm.

The film was prepared at an extrusion temperature of 180 ° C., a die lip gap of 1.4 mm, a take-up speed of 40 m / min, and a blow-up ratio of 5.0.

(Comparative Example 2) As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 910 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 2.1) ) 50%, having a density of 900 kg / m ³ as a linear low density polyethylene (B);
25% ethylene / α-olefin copolymer (MFR = 2.0) having 4 carbon atoms and a density of 92
4 kg / m ³ high pressure method polyethylene (C) (MFR =
2.0) A film having a thickness of 11 μm was prepared by a T-die method using a composition containing 25% and 1.5 parts of diglycerin laurate as an antifogging agent.

Comparative Example 3 As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 918 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 4.0) ) 50%, having a density of 900 kg / m ³ as a linear low density polyethylene (B);
25% ethylene / α-olefin copolymer (MFR = 2.0) having 4 carbon atoms and a density of 92
4 kg / m ³ high pressure method polyethylene (C) (MFR =
2.0) A composition prepared by adding 25% of a hydrogenated petroleum resin (softening point of 125 ° C.) as a component (D) and 2.5 parts of diglycerin laurate as an antifogging agent was used. A film having a thickness of 11 μm was prepared by a die method.

(Comparative Example 4) As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 915 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 2.3) ) 20%, having a density of 900 kg / m ³ as a linear low density polyethylene (B);
25% ethylene / α-olefin copolymer (MFR = 2.0) having 4 carbon atoms and a density of 92
4 kg / m ³ high pressure method polyethylene (C) (MFR =
2.0) A composition obtained by adding 55% of a hydrogenated petroleum resin (softening point of 125 ° C.) as a component (D) and 2.5 parts of diglycerin laurate as an antifogging agent was used. A film having a thickness of 11 μm was prepared by a die method.

Comparative Example 5 As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 915 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 2.3) ) 85%, having a density of 900 kg / m ³ as a linear low density polyethylene (B);
10% ethylene / α-olefin copolymer having 4 carbon atoms (MFR = 2.0) and a density of 92
4 kg / m ³ high pressure method polyethylene (C) (MFR =
2.0) A composition prepared by adding 5% of hydrogenated petroleum resin (softening point 125 ° C.) as a component (D) and 1.5 parts of diglycerin laurate as an antifogging agent was used. A film having a thickness of 11 μm was prepared by a die method.

Comparative Example 6 As a linear low-density polyethylene (A), an ethylene / α-olefin copolymer having a density of 915 kg / m ³ and an α-olefin having 6 carbon atoms (MFR = 2.3) ) 75%, density 924kg / m
^3. High pressure method polyethylene (C) (MFR = 2.0) 25
% And hydrogenated petroleum resin (softening point 125
C.) A film having a thickness of 11 μm was prepared by a T-die method using a composition containing 2.5 parts of diglycerin laurate and 1.5 parts of diglycerin laurate as an antifogging agent.

Except for Comparative Example 1, Table 2 shows the ratios and densities of the raw materials used in these films, and the evaluation results of tan δ and low temperature drop of the films.

Each of the films of the examples has a viscoelastic property within the range specified in the present invention, has good packaging suitability, and does not generate cracks in a low-temperature drop test at 0 ° C. and -20 ° C. Not recognized or extremely low. On the other hand, each of the films of the comparative examples whose viscoelastic properties were out of the range specified in the present invention had a problem in the suitability for packaging, or had insufficient low-temperature drop strength even if the suitability for packaging was good.

[0048]

[Table 2]

[0049]

[Table 3]

[0050]

The stretch film of the present invention comprises a resin composition containing substantially no chlorine, has good packaging suitability as a normal stretch film, and has properties that can be used for packaging low-temperature-distributed foods. Have

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 9/00 C08L 9/00 23/06 23/06 23/08 23/08 23/20 23/20 65 / 00 65/00 93/04 93/04 F term (reference) 3E086 AD13 AD17 BA02 BB42 CA01 4F071 AA18 AA19 AA21 AA22 AA74 AA77 AH04 BA01 BB06 BB07 4F207 AA07 AA08 AA12 AA46 AA49 AG01 KA01 KA17 BB05 BB05 014 CE004 FD036 FD316 GG02

Claims (5)

[Claims] (1) a resin substantially free of chlorine;
According to dynamic viscoelasticity measurement, frequency 10Hz, temperature -20 ° C
A stretch film having a loss tangent (tan δ) of 0.2 or more measured in 2. 2. It comprises a linear low-density polyethylene (A) having a density of more than 905 kg / m ³ , a linear low-density polyethylene (B) having a density of 905 kg / m ³ or less, and a high-pressure polyethylene (C). When the total of (A), (B) and (C) is 100%, (A) 80 to 10
The stretch film according to claim 1, comprising a resin composition of 10% to 40% and 10 to 50% of (C). 3. A total of 1 of the resins (A), (B) and (C)
With respect to 00 parts, at least one of petroleum resin, terpene, terpene derivative, rosin, rosin derivative and hydrogenated product thereof, polybutene, liquid polybutadiene and liquid polyisobutylene is used as component (D) in an amount of 0.5 to 10 parts. 3. The stretch film according to claim 1, further comprising a seed. 4. The stretch film according to claim 1, which is produced by a T-die method. 5. The stretch film for a hand wrap according to any one of claims 1 to 4.