Heat shrinkable laminated film and method for its production

[Detailed Description of the Invention]

The present invention has low oxygen permeability and relates to a heat contraction film suitable for packing the foodstuffs which include meat and cheese. The film for thermoplastic packing can be put into two large Noriharu, and one is hard or a half-rigid film, and another side is a pliability film. Half rigidity and a hard film are very suitable to the use which needs hot shaping operation to form the film in heat and the autonomous shape (self-SuppOrting) which usually used the vacuum and was fixed. Typically, this film is used when manufacturing a shallow tray in a Prista 1 packing skin package. By contrast, a pliability film only wraps the surroundings of the article which should be packed. One very useful method of performing this manufactures the film which can be contracted when it heats, wraps an article in the film, and is heating the wrapped article and shrinking the film on an article. During [ this ] the operation, a film becomes it tense more and carries out Relationship adaptation at the shape of an article. The low heat contraction film of oxygen permeability should be abuse-proof nature (Abuse-Resistant) highly, and carries out heat contraction to the rational grade at a low temperature rationally. The film with which it is satisfied of these demands, The oxygen barrier layer containing the copolymer of a vinylidene chloride and VCM/PVC was provided by other two polymer layers, i.e., the crosslinked ethylene 1 acetic-acid vinyl copolymer layer, and the lamination usually located between the layers of an uncrosslinked ethylene 1 acetic-acid vinyl copolymer. This laminate film is indicated in these people's U.S. Pat. No. 3741258. Although these laminate films that have a vinylidene chloride copolymer layer give the oxygen permeability and contraction which should be satisfied, use of a vinylidene chloride polymer is accompanied by a certain disadvantage which is well-known to the person skilled in the art. This disadvantageous one is that it was found out that it is necessary to make a plasticizer and stabilizer contain in a vinylidene chloride polymer. Although the object which says that a plasticizer improves a film more workability attains, it has the character which is referred to as that they increase the oxygen permeability of a film and which is not desirable. As for use of stabilizer, it is inescapable to increase a manufacturer's cost and complexity. Therefore, the object of the present invention is to provide a moderate grade with the low heat contraction laminate film of oxygen permeability at a low temperature moderately moreover using other oxygen barrier materials which are heat contraction nature without needing use of a plasticizer or stabilizer. the present invention -- multilayer laminate -- namely The hydrolyzed ethylene 1 acetic-acid vinyl copolymer which has at least 35 mol of unit % guided from acetic acid vinyl before hydrolysis is contained. The film for heat contraction packing which is the lamination which has many layers from two layers or it containing the oxygen barrier layer and the crosslinked olefin polymer layer which change is provided. In at least 1 direction, the desirable film of the present invention is heat contraction nature, as at least 10% of contraction is most preferably given in both directions in every direction. Abbreviated [ of the hydrolyzed ethylene 1 acetic-acid vinyl copolymer ] is often carried out, and it is called ''HAVA8. The statement about HAVA to begin is indicated to U.S. Pat. No. 2386347 published in 1945. the film and cast of HAVA are indicated to U.S. Pat. No. 3183203 after that -- And -- French -- the lamination with A and polyethylene is indicated to U.S. Pat. No. 3540962. To U.S. Pat. No. 3595740, the lamination which has a barrier layer of HAVA, a basal layer of the outside which comprises a thermoplastic polymer, and a heat-sealing layer of an ethylene polymer is indicated as a thing suitable for the packaged goods by which deep-drawing hot shaping was carried out. However, as far as these people get to know, it is not suggested in any of the thing of the above-mentioned specification or others before that a HAVA layer may be used in a heat contraction film. A heat contraction film is manufactured by the method of extending a film and manufacturing the comparatively thin film for Flexibility. The molecule which carried out for Arrangement has frozen molecule distortion (10cked-1nm01ecu1arstrain) which is released only by continuing and re-heating the film, when the film heated and extended is cooled. Release of distortion appears as contraction of a film in itself. the unit drawn from acetic acid vinyl before hydrolysis in the ethylene 1 acetic-acid vinyl copolymer hydrolyzed in order to constitute an effective oxygen barrier layer -- at least 85-mol % -- it contains. namely, the hydrolyzed polymer -- the acetic acid vinyl unit of a hydrolysis form or an unhydrolyzed form -- the whole quantity -- at least 35-mol % -- it should have. It is thought that the hydrolyzed form is generally vinyl alcohol. Since the hydrolyzed polymer has at least 99% of hydrolysis level most preferably at least 50%, as for the polymer, the ethylene 1 acetic-acid vinyl copolymer which is not hydrolyzed [ of everything but a lamination / by which Unlikely use may be carried out ] differs in character. the present invention -- therefore -- if HAVA is used as an oxygen barrier layer, oxygen penetration speed will measure under 73 (23degreeC) -- 30 CC/d, It is easily possible to manufacture the heat contraction lamination smaller than 24hrs and atmospheric pressure which has an oxygen transmission rate sometimes smaller than 20 cC/DN24hrs atmospheric pressure often smaller than 5 CC/D and 24hrs atmospheric pressure. Such penetration speed can be measured by the method of ASTMDl434. Generally, these oxygen barrier properties are approximately equal to the characteristic acquired from the matching lamination which has a vinylidene chloride polymer barrier layer, or better than it. Although the desirable film of the present invention is a film which has at least three layers and the oxygen barrier layer containing HAVA is located between two polymer layers, also Absolutely(ing) -- it is not necessarily directly in contact with them, and at least one of the two polymers contains the olefin polymer which crosslinked. Both cocrosslinking of these two polymer layers is carried out, and the desirable feature of the present invention is the crosslinked most preferably same olefin polymer, for example, polyethylene, or the unhydrolyzed ethylene-vinyl acetate copolymer. As all the layers of the lamination are crosslinked and the following is carried out preferably, it is the special feature of using HAVA as an oxygen barrier material that this lamination by which all the layers are crosslinked can be manufactured. Two polymer layers are the surface coats or outside layers of a lamination preferably, and it is an innermost part layer and an outermost part layer in the tubular form radially. it was used for this detailed in the letter one -- a polymer -- a term -- not only a homopolymer but Plock, and graft polymer, Interpolymer and Terpolymer 1 it was used for - book detailed in the letter one also containing the copolymer to include -- an olefin polymer -- a term includes, not only the polymer of unsaturated hydrocarbon of general formula CnH2n (in inside n of a formula, an integer is shown) but the copolymer of Ole Huynh and other monomers, for example, the copolymer of ethylene and acetic acid vinyl. Olefin -- also Absolutely(ing) -- this is desirable Extent although it is not alpha Olefin. in this specification -- an ethylene-vinyl acetate copolymer -- an unhydrolyzed polymer is meant when the term uses it for reference of being hydrolyzed, making it there be nothing. The film for heat contraction packing which has the low oxygen permeability of the present invention can be manufactured by the following method. This method has an oxygen barrier layer containing the hydrolyzed ethylene-vinyl acetate copolymer containing at least 35 mol of unit % guided from acetic acid vinyl before (a) hydrolysis, The oxygen barrier layer is located between other two polymer layers, and at least one of the two polymer layers has the lamination which is a thing containing the crosslinked polymer, (b) heating the lamination structure to the temperature for Arrangement of the crosslinked polymer -- (c) -- extend the heated lamination, carry out for [ of the olefin polymer which crosslinked ] Arrangement, and comprise manufacturing a heat contraction film by that. general -- the polymer material of the third layer -- namely, -- although it may be crosslinking -- also Absolutely(ing) -- the polymer material which does not need to be crosslinking has a desirable thing in which those for Arrangement of the crosslinked polymer of the first layer are possible at the temperature in which those for Arrangement are possible. In the first mode and desirable mode of the present invention, The process (a) of the above-mentioned method, As the copolymer was described above, including the oxygen barrier layer of the hydrolyzed ethylene-vinyl acetate copolymer, even if it is between other two polymer layers and the two polymer layers are small One forms the lamination which is a thing containing the polymer which may be crosslinked by the operation of ion voltinism radiation (IOnisingradiatiOn), and it is attained by irradiating with the lamination with the radiation, and making the polymer crosslink. In this embodiment, at least two layers of the lamination are crosslinked (three layers crosslinked if it is a polymer by which the third layer may also be crosslinked), and improve the intensity of a lamination by that. Since it may decompose or discolor this irradiation when the vinylidene chloride copolymer is exposed to the radiation of a high dose although it may be irradiated with the film laminate which has a vinylidene chloride copolymer layer, it is not carried out by - General. Therefore, it preceded performing vinylidene chloride polymer coating, and was also able to hang down the result that usually manufactured and irradiated with basic material before, and only this layer of a lamination was crosslinked in that case. It is a valuable advantage of the present invention that it is possible by this embodiment to manufacture the lamination which has an oxygen barrier layer and by which much more more many layers are crosslinked. as for .HAVA which carries out simultaneous extrusion of the three adjoining annular layers of polymer material, and forms a tubular multilayer structure in a desirable method, hydrolyzing to at least 50% is preferred -- and the grade of hydrolysis -- 99% Ri -- enlarging is most preferred. Mol % of the unit guided from the acetic acid vinyl before hydrolysis should consider it as at least 85%, and when it was lower than 35%, it was found out that the hydrolyzed copolymer is not an effective oxygen barrier. The desirable polymer which may be crosslinked by irradiation is an olefin polymer especially polyethylene, and ethylene 1 acetic-acid vinyl copolymer. If the acetic acid vinyl unit content of the copolymer is not blended when using an ethylene 1 acetic-acid vinyl copolymer as a bridge construction polymer in the present invention, it can carry out to to about 15%, and the desirable range is one of 3~12% of the weight of ranges. The ethylene 1 acetic-acid vinyl copolymer can attain the effective acetic acid vinyl content which is mixed with polyethylene and for which it asks. As for the polymer layer by which the HAVA layer is arranged between the above-mentioned polymer layers, it is preferred that both are polyethylene or ethylene 1 acetic-acid vinyl copolymers. Since it both cocrosslinks in a desirable method, they will have the same Orientation accompanied by a well-known advantage. In the example of other polymer materials which may be included as a layer in the laminate film of the present invention, it is polyvinyl chloride further besides an olefin polymer, Polyamide, eye Onomer, an acrylic polymer, polyester, polycarbonate, polystyrene, a vinylidene chloride polymer, and the copolymer of those monomers are included. After manufacturing a tubular lamination, it is made to cool, and it ranks next and makes it flat (Flatten). The tubular structure object which carried out flattening may be called a tape, and the desirable method of O bridge construction which is usually about 1 WI~10'' (2.5~25cfn) width although it is dependent on the last width of a request of a film in the state where flattening was carried out is a method according to irradiation of the tubular lamination which carried out flattening. Generally the term which was used in this specification and which becomes 1 irradiation 1 means the operation of the ion voltinism radiation like the electron which causes X-rays, a gamma ray, and molecule bridge construction directly (however). When using it with the chemical crosslinking agent dispersed in material, both heat and light can consider the form of the radiant energy which causes bridge construction. An electron is a desirable form of radiant energy and is generated by the accelerator which the range of 0.5~2.0me (1 million eV) may obtain commercially preferably. Therefore, in a desirable method, it is irradiated with the tape which carried out flattening by letting it pass in the electron beam to which it emanates from an electron accelerator. until the horizontal OFF intermediary scan of the beam is carried out in the width of a tubular body and a desired dose of radiation is obtained in a typical accelerator as for the tubular body -- it is passage about the inside of a beam -- and you are made to re-pass Generally an electron is in the energy range of 0.5~2.0MEV (1 million eV), and it was found out that it is to the present invention and a desirable total amount level is within the limits of 2.0~12.0 megarad (MR). a dose of radiation -- this detailed in the letter ones -- radiation unit 1 rad 1 (Rad) -- it expresses with a term and denotes 1 million rads or megarad by ''MRl. The dose of radiation which causes the degree of bridge construction of a molecule expresses for convenience. Of course, some are also preferred for any ion voltinism radiation which causes bridge construction between the long chain molecules of an olefin polymer. A bridge construction process is a very important process. It is because it was found out that for Arrangement must have been improved the tubular body by the result with the bubble method for supporting since the intensity of the above-mentioned structure is insufficient, without an exposure dose destroying a bubble to a desirable ethylene 1 acetic-acid vinyl copolymer when less than about 3.0 MR(s). A dose required to strengthen a multilayer structure enough, the ingredient of a molecular weight, density, and bridge construction material -- therefore -- changing and receiving some structures like polyethylene -- a larger dose level than 2.0MR Most ethylene 1 acetic-acid vinyl copolymers crosslink to such an extent that (WOrkwith) that which they become rigidity and process becomes difficult. In this way, the optimal dose level range is between 4~8MR to the most objects. At least one layer made the lamination containing a HEVA layer form after an irradiation process between other two polymer layers which are the things containing the material which crosslinked. sufficient grade for a pulling process (c) making a biaxial drawing produce the heated lamination in the tubular form as a different Noodle thing with the form by which flattening was carried out -- in flayed To -- it is preferred that things attain. A tubular body is heated in the temperature range lower than the crystalline melting point of two or more layers by the layer crosslinked although it was higher than secondary transition temperature, or a case, and it ranks next, and is in flayed To. Although, as for this range, the above-mentioned material shows elasticity, the molecule in the material is a temperature range for Arrangement which have a tendency which carries out for Arrangement in the direction in which the material is extended. When the material which crosslinked is an olefin polymer, the desirable medium for heating the tape which carried out flattening is water near the boiling point or the boiling point. It is known well that they will generally contract the thermoplastics material which carried out for Arrangement the temperature by which for Arrangement is carried out, or near it. Since water is an efficient heat transfer medium comparatively safe available and easily, it is commercially advantageous to manufacture the film structure which is heat contraction nature in hot water or boil underwater. The desirable film accompanying the present invention has this desirable character. After expanding the tubular body which carried out flattening and making it a valve, flattening of it may be cooled carried out, and volume To fix is also good because of storage. The statement about for [ by the bubble method ] Arrangement can be found out to U.S. Pat. No. 3022543. being dependent on the desired film width for Arrangement and film thickness -- 1 -- *~10"' (the tubular body expanded from the diameter of a chip box (1 ay-Flatwidth) of 2.5~25 (: FrL) -- 3 -- it has the diameter of a chip box in which the range of *~36 *" (8.9~ 91CIrL) already expanded -- I will come out.) Such width is only explanatory natural. By adjusting the pressure which uses the temperature for Arrangement, and a tubular body for that of in flayed To, for Arrangement or the grade of extension is controllable like a request. As a practical question, in one way, the tubular body should usually be extended at least 10%, in order to usually give useful heat contraction performance power commercially to the film obtained. The tubular body by which flattening was carried out and which expanded is cut in a lengthwise direction, and it winds around a roll, and it can be good, or can heat seal in a transverse direction, subsequently an interval can be set, it can cut in a lengthwise direction or a transverse direction, and To fix can also manufacture a desired bag. Other advantages of a desirable lamination of the present invention in the case of being the ethylene-vinyl acetate copolymer which two surface coats or lateral surface of the lamination crosslinked, It is in enabling manufacture of the pouch by being able to heat seal it and carrying out the seal of manufacture of the bag from a tubular body, or the sheet of a film together. It can be heat sealed and also has the commercially desirable character to be heat contraction nature in hot water or boil underwater. the bone which it tears, is excellent also in resistance and shock resistance, and has [ laminate film / this / desirable ] I broke it squirrel Trend in a film as a result -- among those, it is made suitable, although it is alike and the included meat is packed. Although the film according to the present invention furthermore shows excellent layer-proof fissility and it is not a thing limited to any specific theory for the present invention to explain this effect, This artificer believes that the interface of some of the layers is that to which bridge construction about horizontal OFF intermediary Some takes place by irradiating with the laminated structure. When it is especially known that the molecule in the ingredient layer of the film will crosslink and this layer carries out fusion junction in the simultaneous extrusion method, the fusion object in a boundary side is mixed and a Be consistent standard exists. Therefore, it theorizes that the molecule from one layer is crosslinking with the molecule in an adjacent layer. The direction which irradiates with all the multilayer structures rather than the much more irradiation of seeing currently carried out with the prior art promotes the more uniform characteristic over all the whole layer, and improves adhesion between layers. The problem of 1 which often encountered in the conventional method for manufacturing a heat contraction laminate film is that very little air may be shut up between layers even in the case of being very careful, and is Oh. And if it extends in order to carry out for [ of the film ] Arrangement, small air bubbles will also be extended and the zone where air bubbles reach as a result of That O will be expanded. These air bubbles give the central point which carries out Perilla frutescens (L.) Britton var. crispa (Thunb.) Decne. of the appearance of a film bad, and causes layer separation. It is an especially valuable advantage of the present invention by using HEVA as an oxygen barrier layer material to make simultaneous extrusion of the layer of a lamination possible. Confinement of the air between layers being lost or becoming the minimum was found out by carrying out simultaneous extrusion. Therefore, as for a laminate film, manufacturing by simultaneous extrusion is preferred. Of course, this method is applied on the occasion of an embodiment which crosslinks crosslinking a base, ranking next and covering it with other layers to the lamination formed in Differently and the beginning. The word which was used in this specification and which becomes 4 simultaneous extrusion 1 means the single extrusion process which mixes many the material which can be pushed out, for example, thermoplastics, wax, or adhesives by a molten state, and it makes into an autonomous complex film from two sorts or it. a flow flat to this simultaneous extrusion -- be -- the annular flow of the same axle -- be -- carrying out simultaneous extrusion of the material which can push out at least two sorts is included. Each flow containing the polymer in which separate extrusion is possible should be supplied from the different Noodle extrusion machine, and it is preferred in the present invention to use the simultaneous extrusion process of carrying out simultaneous extrusion of each class annularly. Simultaneous extrusion Di who can attain this process is shown in U.S. Pat. No. 3802826. However, Like shown, for example in U.S. Pat. No. 3865665 and the method of carrying out simultaneous extrusion of the flat film can be used. In a desirable simultaneous extrusion process, in tie A lip, it is joined in front of die lips, and if an extrusion thing flow is not done so by that, it eliminates the air which will be shut up between layers. Simultaneous extrusion of the HEVA layer between two adjacent layers is also kept so that moisture may be lost from P layer to Publication which is subject to influence with disadvantageous oxygen permeability with moisture. A Substitute chemicals target is made to crosslink irradiation by ion voltinism radiation in the second embodiment of the method of manufacturing the film of the present invention. The desirable crosslinking agent to an olefin polymer is a peroxide, and they are 2, 5-Dimethyl- 2, and 5-Di (t-butyl bar Oxy) hexane as especially the suitable thing is indicated to U.S. Pat. No. 3201503 to polyethylene. In this method, a peroxide is mixed with low density (0.92f1/CC) polyethylene with a blend in an extrusion machine, and peroxide weight percentage is about 0.75 in that case. When adjusting the temperature in an extrusion machine, in order to prevent too early bridge construction in an extrusion machine barrel or Di, it should warn to make it lower than 300'F' (149degreeC) or it. The sectional view thickness of the wall at last time is preferred, and the tape should make Di the range of 14~16 mil (356~406 microns). In order to make a tape crosslink, the furnace which maintained it to abbreviation 500'F (260degreeC) without carrying out expansion although in flayed do it was also good is passed, and bridge construction takes place comparatively promptly by high temperature there. After bridge construction is completed, a tubular body can be extrusion-covered or simultaneous extrusion covered after this, and can add a HEVA layer so that it may indicate below. Or simultaneous extrusion of the layer containing a crosslinking agent can be carried out with other layers. (In this case, a process (a), i.e., formation of the first lamination) at least one layer contains the crosslinking agent which may be activated with the heat to a bridge construction polymer and the polymer -- Be formed -- making the lamination containing the oxygen barrier layer of HEVA (it described above) form between other two polymer layers [ like ] And it is carried out by heating the lamination and making a polymer crosslink. Subsequently, in flayed Perilla frutescens (L.) Britton var. crispa (Thunb.) Decne. of the tape is let pass and carried out during heat bathing, and for Arrangement is carried out as well as the above. In addition to the above-mentioned chemical bridge construction process, a photosensitive crosslinking agent can be mixed in a polymer layer, and bridge construction can also be induced by exposing to ultraviolet rays. In the third operative condition 2, the crosslinked layer (base) is manufactured first, and it covers with other two indispensable layers by carrying out simultaneous extrusion continuously simultaneous at the following The. Workmanship a is attained in this way by laminating the polymer material which crosslinked, the hydrolyzed oxygen barrier layer of an ethylene 1 acetic-acid vinyl copolymer, and the third polymer layer together. A desirable basic material is an ethylene 1 acetic-acid vinyl copolymer which has the unit guided also in this case from the olefin polymer like polyethylene, and the acetic acid vinyl up to 15 % of the weight. Also in this case, as for extrusion, it is preferred to make a tubular body form annularly. It is preferred to glare by making flat the pushed-out tubular body. In flayed To, however extension do not carry out a base after irradiation, but, subsequently it passes coating Di. This method and suitable coating Di are indicated to these people's U.S. Pat. No. 3607505. When passing coating Di, a tubular base is covered with HEVA, subsequently the second coating Di is passed and other polymers are covered there. As for the second polymer coating, it is preferred to comprise the olefin polymer like the blend of poly butene-1 and an ethylene propylene copolymer indicated to these people's U.S. Pat. No. 3891008. However, a polyethylene or ethylene 1 acetic-acid vinyl copolymer can be used. After the second polymer coating is covered, the multilayer tubular body turns into a three-layer structure which has a HEVA layer and the crosslinked polymer layer. Subsequently, this annular structure can be cooled and it can be made flat after this. the tubular lamination which it was a biaxial drawing preferably as described above for extension, but was made flat -- a suitable temperature for Arrangement of a base, and * -- although it is generally a range under bottom [ of 180 ]~250 (82~121degreeC) to an olefin polymer base It is alike, and heats and carries out for [ of it ] in flayed Distribution by the valve method. The layer which makes pass simultaneous extrusion Di and is directly covered by the base in a base in simultaneous extrusion coating in the case of carrying out simultaneous extrusion on the base which crosslinked many layers in that case from two or it is a HEVA layer, and the outermost layer is an olefin polymer layer. By request, simultaneous extrusion covering of many layers can be carried out from three layers, four layers, five layers, or it at a base, and the base can have a single layer or a multilayer. The additional HEVA layer used into the desired multilayer structure and the structure using a series of simultaneous extrusion coating can be built. Thus, for [ of the manufactured tubular lamination ] Arrangement can be carried out by the valve method similarly [ until now ]. Although the composition of the multilayer structure of a tubular form which has an annular layer is included by the desirable method of manufacturing the multilayer laminate of the present invention, Carrying out simultaneous extrusion of many layers from three layers or it, or by pushing out and covering one layer on other layers, a polymer layer and a HEVA layer are sometimes pushed out within the limits of the present invention. After crosslinking this multilayer structure by irradiation preferably, the structure is heated to the temperature for Arrangement, and, subsequently it extends by the well-known tenter frame method, and carries out for [ of the above-mentioned structure ] Arrangement. The present invention includes the meat and cheese which contained the bone also especially in the article packed, of course with the film of the present invention which carried out heat contraction, especially food. The following example explains the present invention. Example 1 The laminated tape which has 4-inch (10.2CTrL) width, and comprises the following layer, : manufactured according to the above-mentioned simultaneous extrusion process of having concentric ring-like Di -- the layer of the 4.5-mil (114 microns) thickness of the layer/ethylene-vinyl acetate copolymer of the 2.0-mil (51 microns) thickness of a layer/HEVA with a thickness of 14 mil (356 microns) of an ethylene-vinyl acetate copolymer. The first quoted layer is a layer which turns into an innermost part layer in the radial direction of the pushed-out ring formation, and it applies this displaying method to an example besides future. The content of the unit guided from the acetic acid vinyl in the ethylene-vinyl acetate copolymer (unhydrolyzed) under this lamination is 3.5~5 % of the weight, ASTM method Dl238 conditions E determine the melt flow index of That's it, and it is 0.5, and is Oh. HEVA is the output of 99% hydrolysis of the ethylene-vinyl acetate copolymer which has 69 mol of unit % guided from acetic acid vinyl, and is Oh. ASTM method Dl238 and conditions L determined this thing, and it had about 6.0 melt flow index. When all the three extrusion things come out of a die orifice, those temperature is the about 425 bottoms (218degreeC), and they is Oh. By cooling a tape, when it was made flat, it had a width of 4 inches (10cnL). The inside of the scanning beam of the core transformer electron accelerator with which this tape was insulated in 0.5MEV is passed twice, the tape receives the total dose of 6.5MR there, and it is I got it.. After irradiation, boil underwater is passed, and the tape which carried out flattening is used as an in flayed do it valve, and for Arrangement is carried out, and it is formation Made about the tubular body of 16 inches (41cTn) in diameter, and 2.3-mil (58 microns) thickness. This valve is very stable, and the appearance of the film is good, and it is Oh. The film obtained had the free contraction percentage (Freeshrinkage) of 22% in a lengthwise direction, and the free contraction percentage of 32% in a transverse direction under 195 (91degreeC). Free contraction percentage was determined by the ASTM method D2732. The HEVA layer of Phylum is 0.20-mil (5.1 microns) thickness, and is Oh. It measures by the ASTM method D2838, is a lengthwise direction, is 311p.s.i. (22K9/Cli) and a transverse direction, and is 629p.s.i. (44~/Cli), and contraction Force at the temperature under 195 (91degreeC) is Oh. It is Made about the tubular body which manufactured the width of the tubular body in this example by heat sealing a horizontal OFF intermediary transverse direction, and subsequently to a seal cutting a tubular body immediately behind a seal in parallel and which carried out for Arrangement to a bag. A beefsteak is put in this bag, air is extracted from these packaging goods, and it seals with a Bag metal clip, and makes it contract exactly around a steak by putting packaging goods for a short time in the heat bathing subsequently to the temperature of 190T~210T (88~99degreeC) maintained. Packaging goods were immediately cooled to 34'F' (1degreeC) after this, and it stored at this temperature for four weeks. The color of the steak was evaluated periodically. After storage, it has sufficient Color preservation and took out from packaging goods, bloom was carried out for 30 minutes in the air, and it returned to the appearance of the scarlet color, and subsequently, in the tray, the steak was wrapped in and, subsequently to a display case, was put. Four days after setting in a display case, the beefsteak had a still permissible color. Color preservation in the end of the period for four weeks proved the low oxygen permeability of the laminate film, and the usefulness as the contractile packaging material. Examples 2 and 3 The conditions of Example 1 and the same extrusion conditions are used, Width 4?1 direct 11.4C1! L The layer of the ethylene 1 acetic-acid vinyl copolymer of the HEVA layer / 5.5 mil (140 microns) thickness of the layer / 2.25 mil (57 microns) thickness of the ethylene 1 acetic-acid vinyl copolymer of :17-mil (432 microns) thickness which manufactured the lamination tape which has and comprises the following layer. The content of the unit guided from the acetic acid vinyl in the ethylene 1 acetic-acid vinyl copolymer (unhydrolyzed) of this lamination is 3.5 % of the weight, and ASTM method Dl238 conditions E determine that Methot flow index, and it is 0.5, and is Oh. The same HEVA polymer as the thing of Example 1 was used. If the tape with which it is not irradiated [ of This Q composition ] is expanded and it is made into a valve, it will be I must break it. the tubular body which carried out flattening -- Example 1 and the To -- making it like, glaring and passing boil underwater -- the valve method -- for Arrangement and in flayed Made me. in flayed irradiated with the valve to the dose level of the range of 3~6MR -- the bottom can manufacture by a tubular body and it can maintain the continuous manufacture should be satisfied with the tape with which it was irradiated to the dose of 7.5MR and 9.5MR, respectively of manufacture. Making a dose increase more highly than a 9.5MR level did not try. It is because material is rigidity too much and it was generally shown with many the dose levels from 12MR in the experience about other ethylene 1 acetic-acid vinyl copolymer laminations that it is difficult for Arrangement and to carry out a seal. The characteristic of the film laminate of Examples 2 and 3 was summarized to the following table, and the exposure dose was shown. It carries out as [ indicated / to Actual execution 1 / using the lamination of Examples 2 and 3 ], and packing of a beefsteak is It was done. Color preservation and the storage life which should be satisfied were attained in the examination on the film of all the three examples. Example 4 The above-mentioned simultaneous extrusion method, and the conditions of Example 1 and the same extrusion conditions are used, : which manufactured the tape which comprises the following layer -- ethylene 1 of 16-mil (406 microns) thickness -- the layer of the ethylene 1 acetic-acid vinyl copolymer of the HEVA layer / 6 mil (152 microns) thickness of an acetic acid vinyl copolymer / 2 mil (51 microns) thickness. From the blend of 25% of the ethylene-vinyl acetate copolymer which has 9% of the unit guided from 75 % of the weight of ethylene 1 acetic-acid vinyl copolymers and acetic acid vinyl which have unit 3? weight % to which the used ethylene 1 acetic-acid vinyl copolymer (unhydrolyzed) was guided from acetic acid vinyl to Was formed The same HEVA polymer as the thing of Example 1 was used. in flayed -- the bottom -- the width of a tubular body -- 4lambda611 (it is 10.6 (VL) and irradiated with the tubular body made flat to the dose of about 7.5 MR(s).) The tubular body which is obtained by carrying out as [ indicated / in the Example 1 / the tubular body ], and carrying out for Arrangement from boil bathing and which carried out for Arrangement is 16 inches (41CrfL) in diameter, and had a thickness of 2.0~2.5 mil (51~63 microns). Example The conditions of the simultaneous extrusion process and Example 1 which were described above five times, and the same extrusion conditions are used, The tape which comprises the following layer manufactured : -- the layer of the ethylene 1 acetic-acid vinyl copolymer of 9-mil thickness which has unit 3I / 2 % of the weight guided from the layer / acetic acid vinyl of HEVA of the layer / 2.5 mil thickness of the ethylene-vinyl acetate copolymer of 15-mil (381 microns) thickness which has 9 % of the weight of units guided from acetic acid vinyl. The same HEVA polymer as the thing of Example 1 was used. The tape made flat is 4%. It is * (11.8 cm) width, and irradiates with this to the dose level of about 6.5 MR(s), after [ Naturally ] in flayed -- for Arrangement was carried out by the Trapdo valve method (Trappedbubbletechnique) from Hot water Shigeru which maintained the tape to 210T (99degreeC) in the bottom. in flayed obtained -- although the tubular body had a width of 14 inches (36-) in the bottom, the internal layer of the ethylene-vinyl acetate copolymer which has 9 % of the weight of units guided from acetic acid vinyl encountered difficult in that it has a tendency which sticks in itself and it fuses. in Example 6 and the 7 above-mentioned examples, HEVA has low melt flow index (6.0) relatively, and Oh sets it in the Examples 6 and 7 -- &EVA -- ASTM method Dl238 conditions LVC -- it determined more and had about 19.0 melt flow index. It is because the ethylene unit content in a copolymer increased change of melt flow. The content of the unit guided in Example 6 from the acetic acid vinyl in an unhydrolyzed ethylene 1 acetic-acid vinyl copolymer is 3.5 % of the weight, and is 9 % of the weight in Example 7, and is Oh. Extrusion conditions similar to the conditions of the above-mentioned simultaneous extrusion process and Example 1 are used, : which manufactured the tape which has the following layer -- the layer of the 6-mil thickness of the layer / ethylene 1 acetic-acid vinyl copolymer of the 2-mil (51 microns) thickness of the layer/HEVA of the 16-mil (406 microns) thickness of an ethylene-vinyl acetate copolymer. The width of the tape made flat is 4 and 6W1 (10.6 A), and irradiated even the dose level of about 7.5 MR(s) with this tape made flat. Subsequently, preliminary heating of the tape was carried out, and for Arrangement was carried out by hot water under 200 (93degreeC) to in flayed Law in Example 7 in Example 6 from boil water. The diameters of a chip box of the tubular film obtained in this way are 161 / 2 * * (42-), and the range of the thickness is 1.8~2.5 mil (46~63 microns), and it is Oh. The problem of extrusion or Improve distribution was not encountered. Example 8 similar to the conditions of the above-mentioned simultaneous extrusion method and Example 1 -- carrying out extrusion condition Used : which manufactured the tape which has the following layer -- the layer of the 10-mil (250 microns) thickness of the layer/low density polyethylene of the 1.5-mil (38 microns) thickness of the layer/HEVA of the 12-mil (305 microns) thickness of low density polyethylene. The ethylene-vinyl acetate copolymer and HEVA polymer which were used are as having indicated in the Example 1, and are Oh. This tape that carried out flattening is 4-inch (10cTn) width, and it irradiated even the dose of about 8.5 MR(s) with it after this. Preliminary heating of the tape with which it irradiated was carried out, and for Arrangement was carried out from boil heat bathing. The last tubular body gauge is in the range of 2.2~2.8 mil (56~71 microns), and the film had the free contraction percentage of 26% in the transverse direction 26% under 195 (91degreeC) in the lengthwise direction. It proves that the above-mentioned example can manufacture successfully the heat contraction laminate film which has a HEVA layer.