JP2002307626A - Nylon 6 type multilayered casing film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a casing film suitable for packaging solidified matter of pasty meaty content such as sausage, ham or the like from a multilayered casing film obtained by laminating a nylon 6 layer excellent in mechanical characteristics and a polyolefin layer while maximally putting the characteristics of the nylon 6 layer to practical use. SOLUTION: The nylon 6 type multilayered casing film comprises a multilayered film which has two polyamide layers, that is, an outside polyamide layer (a) and an inside polyamide layer (b). A non-polar polyolefin layer (c) held between a pair of adhesive polyolefin layers is arranged in between. (1) The outside polyamide layer (a) comprises nylon 6, (2) the inside polyamide layer (b) comprises a polyamide (co)polymer, (3) the outside polyamide layer (a) has thickness 1 to 4.5 times that of the inside polyamide layer (b), and (4) the non-polar polyolefin layer (c) has thickness equal to or less than that of the outside polyamide layer (a).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer casing film for packaging a food consisting of a filled and solidified paste-like meat content such as sausage and ham. Specifically, the properties required for the multilayer casing film for packaging these foods, nylon 6 layer as the main constituent material,
The present invention also relates to a polyamide-polyolefin-based multilayer casing film achieved by a simple layer constitution in combination with a polyolefin which is also a general-purpose resin material.

[0002]

2. Description of the Related Art In general, foods such as sausages and hams are
After filling and packaging the paste-like meat content in the film-like casing, the paste is heated, sterilized / cooked, and provided to the market. The characteristics to be satisfied by the casing (film) in the production / distribution process include the following.

(A) Strength / rigidity: Basics such as not being ruptured due to an increase in internal pressure during filling and heating of pasty meat contents, and not being damaged against external stress when handling products. Required as a characteristic. (B) Heat creep resistance: required to prevent deformation during filling, heating and storage of the contents. In general,
After filling the contents, the filling is hung and heated, but if the shape of the product is largely deformed from its cylindrical shape by its own weight, the appearance of the product is impaired and the value is significantly reduced. As described later, the evaluation is made based on the hot water creep property or the hanging deformation rate as a practical evaluation. (C) Gas barrier properties: required to prevent deterioration of the contents due to oxidation. (D) Shearing property: In order to improve the efficiency of filling the casing with pasty processed meat, the casing is often sheared (a longer casing is folded into a bellows shape). This is desirable as a property for preventing delamination or destruction of layers in a pinhole or a multilayer film. (E) Water vapor barrier property: required to prevent loss of water during distribution of sausage and ham products (this not only causes direct economic loss due to weight loss but also leads to deterioration of meat quality). (F) Meat adhesion: The property that the meat of the contents and the inner film interface of the casing adhere to each other, and are required to suppress the generation of meat juice at the interface and prevent the spread of spoilage. (G) Heat shrinkability: required to prevent wrinkles from occurring on the surface of the product casing that gives an impression of product deterioration.

The above (g) imparting heat shrinkability and (a)
In order to improve the strength / rigidity and (ii) the heat creep resistance, a process of heating the casing film to a temperature equal to or higher than the glass transition temperature and stretching the film uniaxially or biaxially is usually performed.

[0005] Since it is difficult to form a casing satisfying the above-mentioned characteristics with a single-layer film, a multilayer casing film having a plurality of constituent layers is usually used. As an example of such an attempt, the above (a)
Outer and inner constituent materials are polyamide resin with excellent strength and rigidity, (b) heat creep resistance, (c) gas barrier properties, and (f) meat adhesion. Non-polar polyolefin layer inside to improve water vapor barrier properties. (Japanese Patent Application Laid-Open No. Hei 8-505758 (International Publication WO95 / 1370)).
No. 7) and International Publication WO00 / 59724).

However, the above-mentioned multilayer casing film is composed of a partially aromatic polyamide (typically, a polyamide having metaxylylene adipamide as a structural unit) blended to improve the stretchability of a polyamide layer contained in the multilayer film material. The balance of the properties of the polyamide layer between the inner and outer layers is not always ensured by using (commonly known as “nylon MXD6”) (Japanese Patent Application Laid-Open No. 8-5055781) or by using a copolymerized nylon 6-66 layer (WO00 / 59724). The characteristics such as strength and rigidity and (b) heat creep resistance required for the multilayer casing film were not always satisfactory.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a polyamide-polyolefin multilayer casing film which achieves the characteristics required for the above-mentioned multilayer casing film by maximizing the use of nylon 6, which is the most general-purpose polyamide resin. The main purpose is to give

[0008]

SUMMARY OF THE INVENTION The multilayer casing film of the present invention has been developed to achieve the above-mentioned object, and more specifically, comprises an outer polyamide layer (a) and an inner polyamide layer (b). Having two polyamide layers,
And a multilayer film comprising a nonpolar polyolefin layer (c) sandwiched between a pair of adhesive polyolefin layers between them; 1) an outer polyamide layer (a) comprising nylon 6; 2) an inner layer. The polyamide layer (b) is made of a polyamide (co) polymer; 3) the outer polyamide layer (a) is the inner polyamide layer (b)
4) The non-polar polyolefin layer (c) has a thickness equal to or less than that of the outer polyamide layer (a).

[0009] The following is a brief description of how the present inventors studied for the above-mentioned purpose and reached the present invention.

[0010] Nylon 6 is a representative of general-purpose aliphatic polyamide, and its film is required for the above-mentioned casing (film) to have (a) strength and rigidity, (b) heat creep resistance, and (f) meat adhesion. It is a well-known fact that the gas barrier property is extremely excellent and the gas barrier property is good. However, in addition, (e) when a nylon 6-polyolefin laminated film in which a non-polar polyolefin layer is laminated to impart a water vapor barrier property is constituted, the nylon 6-polyolefin laminated film is further co-stretched. Was considered extremely difficult. The first reason is that the adhesion between the two layers is poor,
Since the peeling often occurs between the two, effective stretching is difficult. However, this difficulty has already been solved by inserting an adhesive polyolefin layer modified by, for example, the introduction of an acidic group between the two layers (see JP-A-8-505781).
And International Publication WO00 / 59724).
The second and more essential reason is that for polyolefins (melting points typically around 110-170 ° C.), nylon 6 has a much higher melting point (eg, 225 ° C.) and has a remarkable crystallinity. It is to show. Therefore, it is considered very difficult to find conditions for effective co-stretching while suppressing harmful crystallization during stretching for the nylon 6-polyolefin laminated film. For this reason, Japanese Patent Application Laid-Open No. 8-5055781 solves this problem by blending a partially aromatic polyamide (polyamide MXD6). This partially aromatic polyamide has better gas barrier properties than nylon 6,
(C) It functions well in the sense of improving gas barrier properties.
However, this partially aromatic polyamide is a special polyamide resin, and its incorporation is not only uneconomical, but also impairs the excellent (a) strength and rigidity which are the most characteristic features of nylon 6. Also, partially aromatic polyamide,
If used more as the inner polyamide layer which is easily affected by moisture and comes into contact with the paste-like content, the gas barrier property as a characteristic thereof cannot be sufficiently exhibited. Therefore, in Japanese Patent Application Laid-Open Publication No. Hei 8-505578, it is assumed that a similar polyamide composition is used for the outer polyamide layer and the inner polyamide layer, and the ratio between the outer polyamide layer and the inner polyamide layer is 4.6: 1 (Example). Although a large thickness ratio such as is adopted, this is a multilayer casing film governed by an outer polyamide layer and an inner polyamide layer,
This is not always preferable, especially when the balance of mechanical properties is taken into consideration (for example, since the film is easily curled, the filling operation of the paste-like content becomes difficult. More specifically, for example, the casing after the filling is used) This makes it difficult to attach clips to seal the edges of the film.)

[0011] On the other hand, in WO 00/59724, the problem of the difficulty of co-stretching a nylon 6-polyolefin laminated film is solved by combining one layer of nylon 6 with another thicker polyamide layer. This solves some of the problems associated with the use of partially aromatic polyamides described above, but again, nylon 6
It works in a direction that impairs the excellent (a) strength and rigidity and (b) the heat creep resistance, and (c) the gas barrier properties are inferior to those of the structure mainly composed of nylon 6 layers.

[0012] The present inventors, in contrast, nylon 6-
The problem of the difficulty of co-stretching of the polyolefin laminated film is that the outer polyamide layer made of nylon 6 is used as the main polyamide layer, and under the condition that the thickness is equal to or more than that of the polyolefin layer, the coextrusion is performed once.
The cooled nylon 6-polyolefin laminated film is heated to a stretching temperature in a very short time (for example, 70 to 80 ° C).
(Within 5 seconds in a warm water bath) and then immediately subjected to stretching, which solved the problem and found that appropriate co-stretching conditions were set, and reached the present invention. This allows
A multilayer casing film of the present invention is obtained in which the advantages of the nylon 6-based polyamide-polyolefin multilayer film are fully enjoyed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The basic layer structure of the multilayer casing film of the present invention has two polyamide layers, an outer polyamide layer (a) and an inner polyamide layer (b), and a pair between them. A non-polar polyolefin layer (c) sandwiched between the adhesive polyolefin layers.

The outer polyamide layer (a) is made of nylon 6 which is particularly excellent in strength, rigidity, heat creep resistance, meat adhesion and gas barrier properties. Its melting point is generally 2
It is about 20 to 230 ° C. Outer polyamide layer (a)
Is preferably made of nylon 6 alone except for substantially (that is, optional additives such as a lubricant and a crystal nucleating agent), but it is preferable that the content of the nylon 6 is not adversely affected, more specifically, up to about 10% by weight. Preferably, other resins may be used together in a proportion of up to about 5% by weight. A typical example of such another resin is another polyamide resin constituting the inner polyamide layer (b) described later.

The inner polyamide layer (b) is composed of a polyamide (co) polymer, ie, a polyamide homopolymer or copolymer, and nylon 6 is most preferable as in the outer layer (a). 6-66, nylon 6-69, nylon 6I (polyhexamethylene isophthalamide) and the like are also used. It is preferable that the melting point is 180 ° C. or more, more preferably 200 ° C. or more. In addition to these polyamide (co) polymers, other resins may be mixed up to about 30% by weight, more preferably up to about 10% by weight. Typical examples are other polyamide (co) polymers such as nylon 66, nylon 69, nylon 612, nylon MXD6, nylon 6I (polyhexamethylene isophthalamide) and nylon 6T (polyhexamethylene terephthalamide). , Nylon 66-6I,
Nylon 6-69, nylon 66-610-MXD6,
Nylon 6I-6T and the like.

In the present invention, the outer polyamide layer (a) is preferably 1 to 4.5 times, more preferably 1 to 4.5 times the inner polyamide layer (b) in order to make the most of the properties of the nylon 6 constituting the outer layer. It has a thickness of more than twice and not more than 4.0 times, more preferably 1.2 to 3.0 times. That is, the outer polyamide layer (a) which is most required for mechanical strength, rigidity and creep resistance has a thickness at least equal to or greater than that of the inner polyamide layer (b). However, if the outer polyamide layer (a) is more than 4.5 times thicker than the inner polyamide layer (b), the product multilayer casing film will curl during filling of the paste-like content, for example, with a clip It is not preferable because the sealing operation of the casing end portion due to the above becomes difficult. In particular, when hot water heating is performed prior to heat stretching, crystallization of the outer polyamide layer (a) due to moisture absorption is promoted, and the expansion force during heat stretching is excessively large, and stretching is hindered.

A nonpolar polyolefin layer (c) sandwiched between a pair of adhesive polyolefin layers is disposed between the two polyamide layers (a) and (b). The non-polar polyolefin layer (c) is provided to secure the water vapor barrier property of the product multilayer casing film, but its thickness is equal to or less than that of the outer polyamide layer (a) so as not to impair the stretchability of the multilayer film. Within the range.
The lower limit of the thickness is preferably 30% or more, particularly preferably 50% or more of the thickness of the outer polyamide layer (a) from the viewpoint of necessary water vapor barrier properties.

As the nonpolar polyolefin resin constituting the nonpolar polyolefin layer (c), a homopolymer or copolymer of polyolefin is used, and its melting point is 8
It is 0 ° C. or higher, preferably 110 ° C. or higher. Specific examples thereof include an ethylene-α-olefin copolymer, for example, V
LDPE (ultra low density polyethylene), LLDPE (linear low density polyethylene), etc., and polypropylene resins such as PP (polypropylene), PP-Et
(Propylene-ethylene copolymer), PP-Et-Bu
t (propylene-ethylene-butane copolymer). As the non-polar polyolefin resin constituting the non-polar polyolefin layer (c), LLDPE, P having relatively excellent heat resistance
The use of P and PP copolymers tends to improve the heat creep resistance of the resulting multilayer casing film.

The non-polar polyolefin resin may be mixed with a coloring agent to color the non-polar polyolefin layer (c). This embodiment is preferable in that the heat deterioration of the colorant is reduced as compared with the embodiment in which the polyamide layer (a) or (b) is colored, and is more extruded than the embodiment in which the polyamide is blended with the adjacent adhesive polyolefin layer. It is preferable in that it does not cause deterioration in the properties.

The non-polar polyolefin layer (c) is disposed between the above-mentioned polyamide layers (a) and (b) sandwiched between a pair of adhesive polyolefin layers. This adhesive polyolefin layer firmly adheres the non-polar polyolefin layer (c) having poor adhesion to the adjacent layer, particularly the polyamide layer (a) or (b), and prevents delamination in the stretching step or the shearing step. At the same time, there is an effect of improving the pinhole resistance of the product multilayer casing film. However, the adhesive polyolefin resin has a low cohesive force, and when it is thick, it is difficult to improve the strength due to the cohesive failure of the adhesive polyolefin layer itself. It is also conceivable to mix an adhesive polyolefin resin and a non-polar polyolefin layer and arrange a single adhesive polyolefin layer having a water vapor barrier property between the polyamide layers (a) and (b). The inherent adhesive effect of the conductive polyolefin layer is reduced, and it is difficult to expect desired properties. Therefore, the adhesive polyolefin layer and the non-polar polyolefin layer (c)
It is preferable to dispose the non-polar polyolefin layer (c) between the polyamide layers (a) and (b) in such a form that the non-polar polyolefin layer (c) is sandwiched between a pair of adhesive polyolefin layers.

As the adhesive polyolefin resin constituting the adhesive polyolefin layer, at least one kind of adhesive polyolefin resin is selected from a copolymer of acid-modified ethylene and α-olefin and an acid-modified polypropylene resin. , For example, VLDPE, LLDPE, PP,
Acid-graft-modified products such as PP-Et and PP-Et-But can be used.

The most preferred embodiment of the multilayer casing film of the present invention is the above-mentioned outer polyamide layer (a) and inner polyamide layer (b), and a non-polar polyolefin layer sandwiched between these by a pair of adhesive polyolefin layers. It is a multilayer casing film having a five-layer structure in which (c) is arranged. As a result, a multilayer casing film in which the various properties (a) to (g) required for the multilayer casing film of the paste-like content described above are favorably harmonized is obtained. However, additional layers can be inserted as needed to enhance some of these properties or for other purposes.

For example, to enhance gas barrier properties, E
It is also possible to insert an intermediate layer made of VOH (a saponified ethylene-vinyl acetate copolymer) or nylon MXD6.

The outer polyamide layer (a) is one of the most preferable embodiments to constitute the outermost layer of the multilayer casing film of the present invention. However, if necessary, further printing treatment can be performed. Yes, and a matte-treated layer may be provided as the outermost layer. In general, it is preferable that the outermost layer for forming a satin finish is also formed as a polyamide resin-based layer. At this time, when the satin finish layer is made of nylon 6, its thickness is included in the thickness of the outer polyamide layer (a). For matting, for example, an inorganic substance or an organic substance is added, and specific examples thereof include fine particles having a diameter of 20 μm or less, such as a silicon oxide compound such as silica, talc, and mica, and a shirasu balloon. . Further, as an organic substance, a thermoplastic resin such as VLPE, LLDP
E, LDPE, EVA, EEA, EAA, EMA, EM
AA, MMA, MAA and the like can be mentioned.

It is also possible to add an inorganic or / and organic substance as a lubricant or a crystal nucleating agent to the polyamide layer (a) and / or the polyamide layer (b) in order to improve the ease of handling of the product multilayer casing film. it can.

The multilayer casing film of the present invention has a total thickness (one sheet) of 15 to 120 μm, preferably 25 to 80 μm.
It is preferable to form a multilayer casing film having a thickness of μm.

The details of each layer are as follows.
0 μm, more preferably 10 to 40 μm, layer (b)
It is 2 to 18 μm, more preferably 3 to 12 μm. The non-polar polyolefin layer (c) has a thickness of 7 μm to 25 μm, more preferably 12 μm to 20 μm. Each of the adhesive polyolefin layers has a thickness of about 0.5 to 5 μm. The gas barrier layer is arranged according to the required gas barrier properties and has a lower limit thickness that satisfies the requirements. The upper limit of the thickness is determined from stretchability. Usually, it is about 1 to 20 μm, preferably about 2 to 10 μm.

The folding width of the multilayer casing film is 50
It is particularly preferable that the thickness is in a range of from 600 mm to 100 mm, which is suitable for hanging and heating sausage casing.

The multilayer casing film of the present invention is co-extruded with a plurality of extruders according to the required number of raw material resins, and is then co-extruded with a tubular body sheet (referred to as a parison) before stretching, and biaxially stretched by inflation. It is preferable to form by forming a film. Stretching ratio is vertical / horizontal (M
D / TD) is about 2 to 4 times, and the MD / TD as a 90 ° C. hot water shrinkage is 5% or more, especially 10% or more, and the nylon constituting the layer (a) (and (b)) It is preferable to secure the strength of No. 6. That is, the annular die is cooled to below the melting point of each layer by applying water to the outer surface of the co-extruded tubular body, and the cooled tubular body is transferred to an orientation region to a temperature at which stretching is possible. Reheat. Here, it is important that reheating be achieved quickly (for example, by passing through a hot water bath at 70 to 80 ° C. within 5 seconds, preferably about 2 to 3 seconds) so as not to promote crystallization of nylon 6. Next, from 80 to 100
The longitudinal direction (MD) and the lateral direction (TD) by the inflation method while auxiliary heating of the tubular body from the outside with hot air of ℃
2 to 4 times each simultaneously biaxially stretched to produce a biaxially stretched tubular film, which is annealed at a temperature of 60 to 100 ° C. and a relaxation rate of 0 to 10% in each direction to form a tubular film. Produce a biaxially stretched multilayer casing film. In addition, good heat creep resistance (for example, as a hot water creep property described later, the MD direction is 25% or less, more preferably 20% or less, and the TD direction is smaller than the MD direction and 20% or less,
In order to obtain (more preferably 15% or less), it is preferable to perform annealing at a temperature exceeding 90 ° C. and under a condition that the relaxation rate is less than 5%. Such an annealing condition is difficult to employ in a polyamide-based multilayer casing film containing copolymerized nylon as a main constituent layer component, because it causes a dimensional change of the multilayer casing film during storage after production and before filling. is there.

The stretching and annealing methods are not limited to the above methods. For example, a heating method using an infrared heater, hot air, or steam may be used.

[0031]

The present invention will be described more specifically below with reference to examples and comparative examples.

With respect to the resins used in the examples and comparative examples, and the obtained multilayer casing film, the following measurements were made, and the above description of the characteristics of the multilayer casing film of the present invention is also based on the results.

(1) Melting point of resin (DSC) About 10 mg of a sample to be measured was precisely weighed, and measured with Perkin-El.
The temperature was raised at 20 ° C./min using mer7 DSC7,
The peak temperature in the endothermic curve is measured as the melting point. When showing multiple peaks, take the main peak,
The peak temperature is defined as the melting point of the resin.

(2) Hot water creep property: A sample strip (length (M)
D) × width (TD) = 150 mm × 20 mm) and sample strip (length (TD) × width (MD) = 150 mm ×
20 mm), mark a position with a length of 100 mm,
Attach a weight to the end so that the load is 1 kgf / mm ² ,
The length of deformation when immersed in hot water at 80 ° C. for 10 seconds is measured, and the amount of deformation relative to the original length is expressed as a percentage. One sample is tested five times, and the average value in each direction is indicated as 20/15 (MD / TD (%)).

(3) Hot water shrinkage: machine direction (MD) and direction perpendicular to machine direction (TD) in the sample film
The sample strip marked at a point 10 cm long from the starting point is immersed in hot water adjusted to 90 ° C. for 10 seconds, taken out, and immediately cooled with normal-temperature water. Thereafter, the length from the starting point to the marked point is measured, a value obtained by subtracting this measured value from 10 cm is obtained, and the ratio of this value to the original length is expressed as a percentage. One sample was tested five times, and the average value for each direction was 12/15 (MD / TD).
(%)).

(4) Gas barrier property (O ₂ TR): Mod
MORN OXTRA manufactured by ern controls
Using an N 100 type oxygen gas permeability measuring device, 30 ° C.
The oxygen gas permeability through the sample is measured under the condition of 100% RH, and is displayed in units of (cm ³ / m ² · day · atm).

(5) Water vapor barrier property (WVTR): Mo
MOCON PERM manufactured by dern controls
Using an ATRAN 3/31 water vapor permeability measuring device,
The oxygen gas permeability through the sample is measured under the conditions of 0 ° C. and 90% RH, and is expressed in (g / m ² · day) units.

(6) Meat stuffing test: A sample casing was overfilled with 110% paste-like sausage so that the length between clips was about 43 to 44 cm and the weight was 2.3 kg, and the upper and lower portions were clipped, and then smoked at 80 ° C. 120 in the chamber
Heat treatment for 10 minutes, immediately water-cooled for 10 minutes, and then suspended in a refrigerator at 5 ° C. and left for 1 day.
The following items were determined.

(6a) Heat creep resistance (suspension deformation rate): ((perimeter of portion 5 cm above lower clip-perimeter of portion 5 cm below upper clip) for the sausage-filled sample after treatment) × 100 / 5 from the lower clip
The determination is made based on the magnitude of the deformation rate (%) defined as the perimeter of a part on a cm). If it is 7% or less, it is a level at which almost no deformation is visually observed.

(6b) Weight loss: After the sausage-filled sample after treatment is left for one month in an atmosphere of 23 ° C. and 50% RH, the sausage weight reduction ratio (%) is determined according to the following criteria: A: Weight loss of sausage for one month is less than 2%, B: Weight loss of sausage for one month is 2% or more.

(7) Shearing property: Judgment is made based on the difficulty of shirring processing (bellows processing for facilitating the filling of the paste-like filling) of the casing: A: The casing is flexible and efficiently folded in a bellows shape Possible (shearing possible), no delamination after peeling, no generation of pinholes observed. B: Shearable, no delamination, no occurrence of pinholes after shearing, but curled, clip attached. C: The casing is too hard to fold sufficiently.

(8) Stretchability: The state of bubble formation is visually observed according to the conditions when a film is formed under the following processes and conditions, and judged by the following criteria: A: Bubble slightly shakes up and down, but forms stably B: Shaking up and down violently or no bubble is formed and stretching is impossible.

(Examples and Comparative Examples)
(The first layer, the second layer,... In order from the inside to the outside)
(Shown as.) (The meanings of the abbreviations will be described later) were subjected to extrusion film forming treatment by the following method to obtain various multilayer casing films.

That is, each resin was extruded by a separate extruder, and each molten resin was coextruded, introduced into a tubular die, and laminated. The obtained parison was cooled by a cold water shower ring at 8 to 20 ° C. and formed into a flat width of 19 to 74 mm. The resulting parison was immediately passed through a 70-80 ° C. hot water bath in 2-3 seconds,
Vertical direction (MD) 2.0 to 3.3 times, horizontal direction (TD) by inflation while supplementary heating with hot air at 0 ° C.
Simultaneous biaxial stretching was performed 2.5 to 3.8 times, and annealing was performed at 60 to 100 ° C. while relaxing 0 to 10% in the machine direction (MD) and 0 to 10% in the transverse direction. The folding width of the obtained biaxially stretched cylindrical casing film was 50 to 210 mm and the thickness was 35 to 50 μm.

The contents of the resins used are indicated by the abbreviations in Tables 1 to 3.

<Polyamide (co) polymer> (Inner layer and outer layer) Ny6.1: Nylon 6, "Amilan C" manufactured by Toray Industries, Inc.
M-1021XF ”(Tm = 225 ° C.) Ny6.2: Nylon 6,“ Novamid 1020 ”manufactured by Mitsubishi Engineering-Plastics Corporation (Tm = 22)
Ny6.3: Nylon 6, "Novamid 1020A" manufactured by Mitsubishi Engineering-Plastics Corporation (Tm = 2
Ny6.4: Nylon 6, “Novamid 1020J” manufactured by Mitsubishi Engineering-Plastics Corporation (Tm = 2)
Ny6-66: Nylon 6-66, "Amilan CM-6041XF" manufactured by Toray Industries, Inc. (Tm = 195 ° C) Ny6-12: Nylon 6-12, "Amilan CM-6541X3" manufactured by Toray Industries, Inc. ( (Tm = 133 ° C.) (Note) “ ^* ” such as Ny6.1 ^* and Ny6.3 ^* is a lubricant masterbatch (“PEM-7Y14” manufactured by Sumika Color Co., Ltd.).
42 ": CaC in ethyl polyacrylate based polymer
6 wt% of O ₃ ) means a 5 wt% compound.

<Polyolefin resin> (Intermediate layer) VLDPE. 1: VLDPE, manufactured by Idemitsu Petrochemical Co., Ltd. “Moretech V0398CN” (Tm = 122 ° C.) LLDPE. 1: LLDPE, manufactured by Idemitsu Petrochemical Co., Ltd. “Moretech 0238CN” (Tm = 122 ° C.) 2: LLDPE, manufactured by Idemitsu Petrochemical Co., Ltd. “Moretech 0248CN” (Tm = 123 ° C.) 3: LLDPE, manufactured by Idemitsu Petrochemical Co., Ltd. “Moretech 0258CN” (Tm = 122 ° C.) PP-Et. 1: PP-Et copolymer, “San Allomer PC74” manufactured by Montell S.K. Sunrise
1R "(Tm = 133 ° C.) PP-Et. 2: PP-Et copolymer, “San Allomer PF63” manufactured by Montell SKD Sunrise
1S ”(Tm = 142 ° C)

<Gas Barrier Resin> (Intermediate Layer) EVOH: EVOH, "EVAL EP" manufactured by Kuraray Co., Ltd.
-G156B "(Tm = 158 ° C)

<Adhesive Polyolefin Resin> m-VL. 1: Acid-modified VLDPE, “Admer NF587” manufactured by Mitsui Chemicals, Inc. (Tm = 123 ° C.) m-PP. 1: Acid-modified PP, “Modic AP P504V” manufactured by Mitsubishi Chemical Corporation (Tm = 140 ° C.) m-VL. 2: Acid-modified VLDPE, “Modic APOF102” manufactured by Mitsubishi Chemical Corporation (Tm = 120 ° C.) m-VL. 3: Acid-modified VLDPE, “Admer SF730” manufactured by Mitsui Chemicals, Inc. (Tm = 118 ° C.) m-PP. 2: Acid-modified PP, “Modic AP P505” manufactured by Mitsubishi Chemical Corporation (Tm = 138 ° C.) m-PP. 3: Acid-modified PP, Japan Polyolefin Co., Ltd.
"Adtex ER333F-2" (Tm = 134
° C) m-PP. 4: Acid-modified PP, “Admer QF551” manufactured by Mitsui Chemicals, Inc. (Tm = 135 ° C.)

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

[0053]

As described above, according to the present invention, a relatively thin non-polar polyolefin layer is provided between a relatively thick outer layer and a relatively thin inner nylon 6 polyamide layer via an adhesive polyolefin layer. By arranging, a stretchable polyamide-polyolefin-based multi-layer casing film is obtained which makes maximum use of the casing material suitability of the excellent paste-like content of the nylon 6 polyamide layer. It is particularly suitable as a casing material for meaty contents such as sausages and hams, but is also suitable for similar casings using pasty raw materials such as cheese.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshinori Tobita 18-13 Kamitamari, Tamari-mura, Niigata-gun, Ibaraki Pref.Resin Processing Technology Center, Kureha Chemical Industry Co., Ltd. 18-13 Kamitamari Kureha Chemical Industry Co., Ltd. Resin Processing Technology Center F-term (reference) 3E086 AD12 BA04 BA15 BA35 BB02 BB05 BB41 BB59 BB67 BB85 CA04 4F100 AK03B AK03C AK03D AK07B AK07D AK46E AK48BA07A07BA07BAK BA25 DA02 EH20 GB16 GB23 JK01 JL11B JL11D

Claims (2)

[Claims] 1. A non-polar polyolefin layer (c) having two polyamide layers, an outer polyamide layer (a) and an inner polyamide layer (b), sandwiched between a pair of adhesive polyolefin layers. 1) the outer polyamide layer (a) is made of nylon 6, 2) the inner polyamide layer (b) is made of a polyamide (co) polymer, and 3) the outer polyamide layer (a). ) Is the inner polyamide layer (b)
4) The non-polar polyolefin layer (c) has a thickness equal to or less than that of the outer polyamide layer (a). 2. The multilayer casing film according to claim 1, wherein both the outer polyamide layer (a) and the inner polyamide layer (b) are made of nylon 6.