JP4769602B2 - Lid material - Google Patents

Description

  The present invention relates to a lid used for packaging containers for foods, pharmaceuticals, chemicals and the like.

As one form of food packaging, a container body formed by molding a sheet made of polypropylene resin or the like is filled with food contents, and then a lid is hermetically sealed on the top of the container body. In particular, when the food is jelly, pudding, teacup, etc., the contents are filled and hermetically sealed, and then boiled or retorted for sterilization of the contents. The laminated film, which is a material, is thermally shrunk to give tension to the cover material, and a package body with a beautiful pack appearance free from wrinkles and sagging is obtained.
In general, it is effective to use a film that is easily heat-shrinkable to a certain extent in order to prevent wrinkles and sagging of the lid material. In this case, the lid material is provided as a knob for opening due to the thermal shrinkage of the laminated film. The problem of curling of the lid knob portion is likely to occur. This is because a non-stretchable film such as a polyolefin resin is generally used for a sealant film of a lid material from the viewpoint of sealing properties, and in order to impart shrinkage, a stretched film having hot water shrinkage on the outside thereof. As a result, it is considered that when the lid member is thermally shrunk, it tends to curl to the outer layer side. When such curling is remarkable, problems such as peeling of the lid material in a process other than the time of opening, and difficulty in pinching the lid material knob portion with a finger at the time of opening have occurred.
In order to prevent the occurrence of curling as described above, it has been proposed to use a PET film having a low thermal shrinkage rate, but in this case, the lid material was insufficiently stretched.

  Ideally, the lid material knob portion should not curl at all, but even if it is slightly curled, it is more desirable to curl downward than to curl upward on the lid material from the viewpoint of appearance or sealing. It is said that. As a method for improving the curling of such a lid material, for example, Patent Document 1 discloses a base film and an intermediate layer film having a hot water shrinkage ratio of 1.5 to 3.0% in the vertical direction and the horizontal direction. A method is disclosed in which the tension of the sealant film is 0.5 to 1.0 times the tension of the laminated film when laminating and further laminating the sealant film on the laminated film obtained by laminating the sealant film. Yes. However, the laminated film obtained by such a method also has a problem in appearance due to insufficient improvement of the curl on the upper side and insufficient tension of the lid.

Japanese Patent Laid-Open No. 11-156983

  It is an object of the present invention to provide a container lid that has excellent appearance, with curling occurring at the time of boiling the tab for opening the container lid, retort sterilization, etc., especially curl to the upper side of the lid. To do.

  The inventor is a cover material having a base film and a co-extruded film containing a polyolefin resin layer as a sealant, and the hot water shrinkage rate when the co-extruded film is held at 85 ° C. for 30 minutes is longitudinal. It is related with the cover material which is 0.5 to 5% in both the direction (MD) and the lateral direction (TD).

  According to the present invention, the container lid material has good tension, and the occurrence of curling at the time of boiling of the opening knob, retort sterilization, etc., especially the curling on the upper side of the lid material is small, and the container has an excellent appearance. A lid can be provided.

The present invention is described in detail below.
The lid material of the present invention has a base film and a co-extruded film containing a polyolefin resin layer as a sealant. This coextruded film has a hot water shrinkage of 0.5 to 5% in both the machine direction (MD) and the transverse direction (TD) when held at 85 ° C. for 30 minutes.
In general, a sealant film made only of a polyolefin-based resin has a hot water shrinkage rate of almost 0 and hardly shrinks. Therefore, in order to impart tension to the cover material, a stretched polyamide film having a high hot water shrinkage rate is provided on the outside. This can be dealt with by bonding, but in this case, the stretched polyamide film of the outer layer contracts, whereby the curl of the lid material knob is pulled upward, and an undesirable upward curl tendency occurs. In this invention, in order to solve this point, the hot water shrinkage rate was provided by using a coextruded film as a sealing layer film. That is, when the seal layer side contracts, the tension is good, and the curl of the lid knob portion can be made to have a tendency to curl slightly from the flat to the seal layer side.

  A method for imparting a preferred hot water shrinkage to a coextruded film containing the polyolefin resin layer as a sealant is not particularly limited, but it is hygroscopic and has a large dimensional change due to crystallization with hot water, such as polyamide or ethylene-vinyl. A method in which an alcohol copolymer (hereinafter sometimes referred to as “EVOH”) or the like is combined with a polyolefin resin by coextrusion is preferably used. As the polyamide, an aliphatic polyamide having a high hygroscopic property, particularly an aliphatic polyamide such as nylon-6 is suitable. When the coextruded film is a coextruded film containing polyamide and EVOH, it is preferable to make the temperature of the die of the extruder as low as possible in terms of thermal stability. It is more preferable to use polyamide obtained by copolymerizing nylon-6 having a low molecular weight of 6 and 25% nylon-66 (a copolymer of hexamethylenediamine and adipic acid), that is, 6-66 nylon.

  There is no restriction on the type of EVOH, and any conventionally known one can be used. In the present invention, the ethylene content is in the range of 25 to 38 mol%, and more preferably in the range of 29 to 35 mol%. The saponification degree is preferably 95 mol% or more, more preferably 98 mol% or more. When the ethylene content is within the above range, the melt extrudability at the time of melt extrusion is good, and the oxygen gas barrier property is good. Moreover, when the saponification degree of EVOH is in the above range, the oxygen gas barrier property is good.

  In addition to the saponified product of ethylene and vinyl acetate binary copolymer, the EVOH includes a small amount of an α-olefin such as propylene, isobutene, α-octene, α-dodecene and α-octadecene as a copolymer component; Saturated carboxylic acids, or salts thereof, partial alkyl esters, fully alkyl esters, nitriles, amides, anhydrides; unsaturated sulfonic acids, salts thereof, and the like may be included. It may be a mixture of thermoplastic resins such as polyester and polyamide.

  As the polyolefin resin constituting the coextruded film, polyolefin and modified polyolefin can be used. Specifically, linear low density polyethylene (LL), metallocene LL using metallocene catalyst, low density Polyethylene resins such as polyethylene (LDPE), high density polyethylene (HDPE), ethylene-vinyl acetate copolymer (EVA), polypropylene (PP), block copolymerization PP with ethylene, random copolymerization PP with ethylene, metallocene Polypropylene resin such as PP, polybutene, ionomer resin, ethylene-ethyl acrylate copolymer (EEA) resin, ethylene-methyl acrylate copolymer (EMA) resin, ethylene-methacrylic acid copolymer (EMAA) resin, Ethylene-methyl methacrylate copolymer Body (EMMA) resin, polyolefin such as ethylene-acrylic acid copolymer (EAA), etc., but from the point that heat resistance during boil processing and the seal layer of the cup are made of polypropylene, polypropylene resin is more Preferably used.

  As the modified polyolefin, generally known polyolefin-based adhesive resins such as LDPE, LL, HDPE, EVA, PP, and polybutene acid-modified products are preferably used. Examples of the unsaturated carboxylic acid used for modification include acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, itaconic acid, citric acid, citraconic acid, sorbic acid, mesaconic acid, cis-4-cyclohexene. -1,2-dicarboxylic acid, endo-cis-bicyclo- [2,2,1] -5-heptene-2,3-dicarboxylic acid, tetrahydrophthalic acid, etc., and these unsaturated carboxylic acids and acids thereof It is obtained by modifying at least one selected from derivatives such as anhydrides, esters and amides by copolymerization (for example, graft copolymerization), and these are used alone or in appropriate combination.

In the present invention, preferred examples of the structure of the coextruded film include the following.
・ Polyamide / Modified polyolefin / Polyolefin ・ EVOH / Polyamide / Modified polyolefin / Polyolefin / Polyamide / EVOH / Polyamide / Modified polyolefin / Polyolefin The above co-extruded film has the ability to seal contaminants, resistance to bag breakage during transportation, and interlayer adhesion strength. Since importance is attached, an unstretched film or a film slightly stretched in the machine direction (MD) is desirable.

From the viewpoint of preventing delamination between layers during transportation and opening with easy peel, the delamination strength of the coextruded film should be 4.9 N / 15 mm width (500 gf / 15 mm width) (tensile speed: 200 mm / min) or more. Is more preferably 6.9 N / 15 mm width (700 gf / 15 mm width) or more, and still more preferably 9.8 N / 15 mm width (1000 gf / 15 mm width) or more.
In the present invention, the coextruded film including the polyolefin-based resin layer is cooled after coextrusion, and is then stretched 0 to 10% in the machine direction (MD) at a film temperature of 20 to 80 ° C. Preferably there is. Thereby, the hot-water shrinkage rate in the MD direction can be controlled. From this point, the stretching is preferably performed at 0 to 7%, more preferably 0 to 5%. Here, stretching with a stretching ratio of 0% includes non-stretching or slightly relaxing (minus several percent). If the stretching exceeds 10%, there is a problem that the shrinkage rate during boil sterilization becomes too high and the container is deformed.

The coextruded film containing a polyolefin resin layer as a sealant has a hot water shrinkage of 0.5 to 5% in both the machine direction (MD) and the transverse direction (TD) when held at 85 ° C. for 30 minutes. If the shrinkage rate is less than 0.5%, the tension of the lid after sterilization of the boil and retort deteriorates. Furthermore, if the shrinkage rate of the base film is compensated, the tension is improved, but the curl of the knob part is improved. Tends to curl upward. On the other hand, if it is 5% or more, the curl of the knob portion is on the lower side but becomes a strong curl, which is not preferable. From the above points, the shrinkage rate of the base film is preferably 0.8 to 4.0%, more preferably 1.0 to 3.0%.
The thickness of the coextruded film is not particularly limited, but is usually 25 to 120 μm, and preferably 50 to 100 μm from the viewpoint of seal stability and cost.

  The base film constituting the lid material is preferably a film having hot water shrinkage in consideration of the tension of the lid material, and biaxially stretched from the viewpoint of strength, hot water shrinkage, printability, and heat resistance. A polyamide film is preferred. Although it does not specifically limit as a kind of polyamide which comprises a biaxially stretched polyamide film, All include aliphatic polyamide, aromatic polyamide, etc. Aliphatic polyamides include ring-opening polymers of cyclic lactams such as ε-caprolactam homopolymer (nylon-6: 6Ny), polycondensates of aminocarboxylic acids, polyhexamethylene adipamide (nylon-66: 66Ny). And polycondensates of dicarboxylic acids and diamines. Among these aliphatic polyamides, ε-caprolactam homopolymer (nylon-6: 6Ny), polyhexamethylene adipamide (66Ny) are available at a low cost and can be smoothly stretched. ) Is preferable, and a homopolymer (6Ny) of ε-caprolactam is more preferable.

The aromatic polyamide is not particularly limited, and examples thereof include resins containing 70 mol% or more of polyamide constituent units composed of xylylenediamine and an α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms in the molecular chain. Preferably mentioned.
Specifically, homopolymers such as polymetaxylylene adipamide, polymetaxylylene pimeramide, polymetaxylylene azelamide, polyparaxylylene azelamide, polyparaxylylene decanamide, metaxylylene / paraxylylene azamide Examples of the copolymer include a amide copolymer, a metaxylylene / paraxylylene pimeramide copolymer, a metaxylylene / paraxylylene azeramide copolymer, and a metaxylylene / paraxylylene sepacamide copolymer.

  A biaxially stretched polyamide film is usually obtained by stretching an unstretched film in at least one direction from the viewpoint of stretching effect, film strength, etc., in the film flow direction (longitudinal direction) and in a direction perpendicular thereto (transverse direction). The film is stretched in the range of 5 to 5 times, preferably 2.6 to 4.0 times in the vertical and horizontal biaxial directions. As the biaxial stretching method, any conventionally known stretching method such as tenter-type sequential biaxial stretching, tenter-type simultaneous biaxial stretching, tubular simultaneous biaxial stretching, and the like can be adopted. For example, in the case of the tenter type sequential biaxial stretching method, the unstretched film is heated to a temperature range of 50 to 110 ° C., and stretched 2.6 to 3.5 times in the longitudinal direction by a roll type longitudinal stretching machine, Then, it can manufacture by extending | stretching 2.6 to 4.0 time in a horizontal direction within the temperature range of 60-140 degreeC with a tenter type horizontal extending | stretching machine. Moreover, in the case of the tenter type simultaneous biaxial stretching and the tubular type simultaneous biaxial stretching method, for example, in the temperature range of 60 to 130 ° C., it is manufactured by stretching 2.5 to 5 times in each axial direction simultaneously in the longitudinal and lateral directions. can do.

It is preferable that the stretched film stretched by the above method is subsequently heat-set. Dimensional stability at room temperature can be imparted by heat setting. In this case, the treatment temperature is preferably in the range of 210 to 225 ° C, more preferably 210 to 220 ° C.
Moreover, it is preferable to perform relaxation in the range of 0 to 15%, more preferably 3 to 10% in the lateral direction during the heat setting. By relaxing, the stress of crystallization shrinkage due to heat fixation can be relaxed.

In the present invention, the base film can be used as a multilayer film obtained by coextruding the above polyamide. Examples of such a multilayer film include coextruded films such as aliphatic polyamide / aromatic polyamide / aliphatic polyamide from the viewpoint of improving gas barrier properties and aroma retention. Moreover, it is preferable to use a film in which EVOH having high gas barrier properties is coextruded with polyamide as both outer layers, for example, nylon-6 / EVOH / nylon-6. In this case, the polyamide ratio is more preferably 50% by weight or more, and further preferably 70% by weight or more from the viewpoint of strength.
As said EVOH, the thing similar to what was used in the coextruded film containing the above-mentioned polyolefin-type resin layer can be used.

Various additives such as a lubricant, an antistatic agent, an antioxidant, an antiblocking agent, a stabilizer, a dye, a pigment, and inorganic fine particles can be added to the base film.
In order to improve the tension of the cover material after boil sterilization, the base film has a hot water shrinkage ratio of preferably 0.5 to 6% for both MD and TD when held at 95 ° C. for 5 minutes. More preferably, it is 1.0-6.0%, More preferably, at least one of MD and TD is 3.0-6.0%.
The thickness of the base film is not particularly limited, but is usually 12 to 30 μm, and preferably 15 to 25 μm from the viewpoint of printability, laminate suitability, strength, and economy.
For laminating the coextruded film including the base film and the polyolefin resin layer, both general dry laminate and polysand laminate can be used. However, in order to strengthen the adhesion between the layers, it is possible to use the dry laminate. preferable.

In addition, as a container body using the lid material of the present invention, a coextruded sheet made of polypropylene / modified polypropylene / EVOH / modified polypropylene / polypropylene is formed from the viewpoint of gas barrier properties, rigidity (stretch strength), and transparency. Are preferably used.
The sealing material is preferably sealed with hot water at 70 to 100 ° C., more preferably with hot water at 80 to 95 ° C., preferably 5 to 120 minutes, more preferably 10 to 60 minutes after sealing the container body. It is used for sterilization processes such as boil and retort sterilization.
An example of a sealed container using the lid of the present invention is shown in FIG. 1, and an example of the lid of the present invention is shown in FIG. In FIG. 1, the sealed container includes a container body 1 and a lid member 2. In FIG. 2, the lid member 2 has a lid member knob portion 21. The container body 1 is filled with an article 3 to be packaged and has an opening edge 11. The lid 2 is made of the above-described laminated film for lid.

EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Evaluation in this example was performed as follows.
A hot water shrinkage stretched film specimen is cut into a width of 120 mm and a length of 120 mm, and a line of about 100 mm is drawn on the sample in the machine direction (MD) direction and the transverse direction (TD). This sample is allowed to stand for 24 hours in an atmosphere of 23 ° C. and 50% RH, and the reference line is measured. The measured length is defined as a length F before the heat treatment. The base film and the intermediate layer film are immersed in hot water heated to 95 ° C. for 5 minutes, and the coextruded film is immersed in hot water heated to 85 ° C. for 30 minutes, both of which are further 23 ° C. and 50% RH. After being left in the atmosphere for 30 minutes, the reference line is measured to obtain a length G after heat treatment.
The heat shrinkage rate is calculated by [(F−G) / F] × 100 (%).
With the above method, each shrinkage rate in the MD direction and TD direction was measured at n = 5, and the average value was defined as the heat shrinkage rate.

  After filling a cup body obtained from a sheet molded article having a thickness of 800 μm with a PP / EVOH / PP structure using a lid material prepared in the following examples and comparative examples, a cup sealer (Minamoto Co., Ltd.) (MFT-500) manufactured at a seal temperature of 180 ° C. for 2 seconds to produce a pack product. The packaged product was boiled with hot water at 85 ° C. for 20 minutes, cooled with water, allowed to stand in an atmosphere of 23 ° C. and 50% RH for 24 hours, and then evaluated as follows.

After the lid was boiled, the tension of the lid after standing for 24 hours in an atmosphere of 23 ° C. and 50% RH was visually evaluated as follows.
○: Tension is good ×: Tension is bad or the cover material shrinks greatly and the container is deformed
After curling the lid knob part, the curl tendency of the lid knob part after being allowed to stand for 24 hours in an atmosphere of 23 ° C. and 50% RH was evaluated as follows (n = 10 pack product was produced and evaluated). .
A: Stable flat or slightly lower curl tendency ○: Flat or slightly lower curl tendency Δ: Strong lower curl tendency X: Overall upper curl tendency The results are shown in Table 1.

Example 1
Each of the following films was dry laminated to produce a laminated film of a base film 15 μm / coextruded film 60 μm.
-Base film: 6Ny (Novamid 1022C6 (Mitsubishi Engineering Plastics Co., Ltd.)) was extruded with a T-die, stretched 3.0 times in the MD direction with a roll, and then 3.4 times in the TD direction with a tenter. A film obtained by stretching, stretching at 210 ° C., and relaxing in the width direction by 7%.
Co-extruded film: EVOH (10 μm) / 6-66 Ny (10 μm) / AD (10 μm) / PP (25 μm) / easy peel layer (5 μm) film EVOH: Soarnol AT4406B (Nippon Synthetic Chemical Industry Co., Ltd.)
6-66Ny: Novamid 2030 (Mitsubishi Engineering Plastics)
AD: Admer QF551 (Mitsui Chemicals, Inc.)
PP: Novatec PP EG6D (Nippon Polypro Co., Ltd.)
Easy peel layer: PP (65%) + LDPE (35%) blend [PP: Novatec PP FG4FA (Nippon Polypro Corporation), LDPE: Novatec LD LF423M (Nippon Polyethylene Corporation)]

Example 2
Each of the following films was dry laminated to produce a laminated film of a base film 15 μm / coextruded film 60 μm.
-Base film: 6Ny (Novamid 1022C6 (Mitsubishi Engineering Plastics Co., Ltd.)) was extruded with a T-die, stretched 3.0 times in the MD direction with a roll, and then 3.4 times in the TD direction with a tenter. A film obtained by stretching, stretching at 210 ° C., and relaxing in the width direction by 7%.
Coextruded film: 6 Ny (5 μm) / EVOH (10 μm) / 6-66 Ny (5 μm) / AD (10 μm) / PP (25 μm) / Easy peel layer (5 μm)
6Ny: Novamid 1022C6 (Mitsubishi Engineering Plastics)
EVOH: Soarnol AT4406B (Nippon Synthetic Chemical Industry Co., Ltd.)
6-66Ny: Novamid 2030 (Mitsubishi Engineering Plastics)
AD: Admer QF551 (Mitsui Chemicals, Inc.)
PP: Novatec PP EG6D (Nippon Polypro Co., Ltd.)
Easy peel layer: PP (65%) + LDPE (35%) blend [PP: Novatec PP FG4FA (Nippon Polypro Corp.), LDPE: Novatec LD LF423M (Nippon Polyethylene Corp.)]

Example 3
Each of the following films was dry laminated to produce a laminated film of a base film 15 μm / coextruded film 60 μm.
Base film: 6Ny (Novamid 1022C6 (Mitsubishi Engineering Plastics Co., Ltd.)) and EVOH (Soarnol DC3203FB) in a 6Ny (40%) / EVOH (20%) / 6Ny (40%) configuration on a T-die A film obtained by co-extrusion, stretching 3.0 times in the MD direction with a roll, stretching 3.4 times in the TD direction with a tenter, heat setting at 210 ° C., and relaxing in the width direction by 7%. .
Co-extruded film: 6Ny (20 μm) / AD (10 μm) / PP (25 μm) / Easy peel layer (5 μm)
6Ny: Novamid 1022C6 (Mitsubishi Engineering Plastics)
AD: Admer QF551 (Mitsui Chemicals, Inc.)
PP: Novatec PP EG6D (Nippon Polypro Co., Ltd.)
Easy peel layer: PP (65%) + LDPE (35%) blend [PP: Novatec PP FG4FA (Nippon Polypro Corporation), LDPE: Novatec LD LF423M (Nippon Polyethylene Corporation)]

Example 4
Each of the following films was dry laminated to produce a laminated film of a base film 15 μm / coextruded film 60 μm.
Base film: 6Ny (Novamid 1022C6 (Mitsubishi Engineering Plastics Co., Ltd.)) and EVOH (Soarnol DC3203FB) in a 6Ny (40%) / EVOH (20%) / 6Ny (40%) configuration on a T-die A film obtained by co-extrusion, stretching 3.0 times in the MD direction with a roll, stretching 3.4 times in the TD direction with a tenter, heat setting at 210 ° C., and relaxing in the width direction by 7%. .
Coextruded film: EVOH (10 μm) / 6-66 Ny (10 μm) / AD (10 μm) / PP (25 μm) / easy peel layer (5 μm)
EVOH: Soarnol AT4406B (Nippon Synthetic Chemical Industry Co., Ltd.)
6-66Ny: Novamid 2030 (Mitsubishi Engineering Plastics)
AD: Admer QF551 (Mitsui Chemicals, Inc.)
PP: Novatec PP EG6D (Nippon Polypro Co., Ltd.)
Easy peel layer: PP (65%) + LDPE (35%) blend [PP: Novatec PP FG4FA (Nippon Polypro), LDPE: Novatec LD LF423M (Nippon Polyethylene)

Comparative Example 1
Each of the following films was dry-laminated to produce a laminated film having a structure of ONy 15 μm / EVOH 12 μm / easy peel 50 μm.
Outer layer: 6Ny (Novamid 1022C6 (Mitsubishi Engineering Plastics Co., Ltd.)) was extruded with a T-die, stretched 3.0 times in the MD direction with a roll, and then stretched 3.4 times in the TD direction with a tenter. Afterwards, a film obtained by heat-fixing at 210 ° C. and relaxing in the width direction by 7%.
Intermediate layer: Eval film EF-XL (manufactured by Kuraray Co., Ltd.)
Seal layer: Easy peel (CMPS017C (manufactured by Tosero Co., Ltd.))

Comparative Example 2
Each of the following films was dry-laminated to produce a laminated film having a structure of ONy 15 μm / EVOH 12 μm / easy peel 50 μm.
Outer layer: 6Ny (Novamid 1022C6 (Mitsubishi Engineering Plastics Co., Ltd.)) was extruded with a T-die, stretched 3.0 times in the MD direction with a roll, and then stretched 3.4 times in the TD direction with a tenter. Afterwards, a film obtained by heat-fixing at 210 ° C. and relaxing in the width direction by 7%.
Intermediate layer: Eval film EF-XL (manufactured by Kuraray Co., Ltd.)
Seal layer: Easy peel (CMPS013C (manufactured by Tosero Co., Ltd.))

Comparative Example 3
Each of the following films was dry laminated to produce a laminated film of ONy 15 μm / coextruded film 60 μm.
ONy: 6Ny (Novamid 1022C6 (Mitsubishi Engineering Plastics Co., Ltd.)) was extruded with a T-die, stretched 3.0 times in the MD direction with a roll, and then stretched 3.4 times in the TD direction with a tenter. Afterwards, a film obtained by heat-fixing at 210 ° C. and relaxing in the width direction by 7%.
Co-extruded film: EVOH (10 μm) / 6-66 Ny (10 μm) / AD (10 μm) / PP (25 μm) / Easy peel layer (5 μm) When forming a film, changing the roll speed at a roll temperature of 60 ° C. A film obtained by 20% longitudinal stretching.
EVOH: Soarnol AT4406B (Nippon Synthetic Chemical Industry Co., Ltd.)
6-66Ny: Novamid 2030 (Mitsubishi Engineering Plastics)
AD: Admer QF551 (Mitsui Chemicals, Inc.)
PP: Novatec PP EG6D (Nippon Polypro Co., Ltd.)
Easy peel layer: PP (65%) + LDPE (35%) blend [PP: Novatec PP FG4FA (Nippon Polypro), LDPE: Novatec LD LF423M (Nippon Polyethylene)

Comparative Example 4
Each of the following films was dry-laminated to produce a laminated film of coextruded ONy 15 μm / easy peel film 50 μm.
ONy: 6Ny (Novamid 1022C6 (manufactured by Mitsubishi Engineering Plastics Co., Ltd.)) and EVOH (Soarnol DC3203FB) in a 6Ny (40%) / EVOH (20%) / 6Ny (40%) configuration on a T-die A film obtained by extruding, stretching 3.0 times in the MD direction with a roll, stretching 3.4 times in the TD direction with a tenter, heat setting at 210 ° C., and relaxing in the width direction of 7%.
Seal layer: Easy peel (CMPS017C (manufactured by Tosero Co., Ltd.))

  The lid material of the present invention is suitably used for food containers such as jelly, pudding, and teacup, and packaging containers for pharmaceuticals and chemicals.

It is a fragmentary sectional view which shows the cross section of an example of the container using the lid | cover material of this invention. It is a perspective view which shows an example of the cover material of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Container body 2 Cover material 3 Packaged object 11 Opening edge 21 Cover material knob part

Claims (7)

  A cover material having a base film and a co-extruded film containing a polyolefin-based resin layer as a sealant, wherein the hot-water shrinkage ratio when the co-extruded film is held at 85 ° C. for 30 minutes has a machine direction (MD) and A lid material of 0.5 to 5% in both the transverse direction (TD).   The lid according to claim 1, wherein the coextruded film is a polyamide / modified polyolefin / polyolefin coextruded film.   The lid material according to claim 1, wherein the coextruded film is a coextruded film of ethylene-vinyl alcohol copolymer / polyamide / modified polyolefin / polyolefin.   The lid material according to claim 1, wherein the coextruded film is a coextruded film of polyamide / ethylene-vinyl alcohol copolymer / polyamide / modified polyolefin / polyolefin.   The cover material according to any one of claims 1 to 4, wherein the co-extruded film is stretched 0 to 10% in the machine direction (MD) at a film temperature of 20 to 80 ° C after co-extrusion and cooling. .   The base film has a biaxially stretched polyamide film having a hot water shrinkage of 0.5 to 6% in both the machine direction (MD) and the transverse direction (TD) when held at 95 ° C for 5 minutes. The lid according to any one of 5.   The lid material according to any one of claims 1 to 6, wherein the base film has a biaxially stretched film made of polyamide / ethylene-vinyl alcohol copolymer / polyamide.

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