JPS6367473B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to packaging materials for cheese, yokan, etc., which are laminated onto various base materials by extrusion coating and filled in a heated and molten state. Furthermore, the present invention relates to a packaging material that can be heat-sealed at low temperatures or sealed only by pressure, and that also has easy peelability. The characteristics of the present invention are that it can be heat-sealed only by the heat of the contents filled in a heated molten state, has excellent adhesion to the contents, can be easily cut with a knife, etc., and can be sealed tightly. It has sufficient properties and the pattern layer can be transferred to the contents. Generally, among processed cheeses, most of the home-use carton stuffed cheeses weighing about 150g to 400g are filled and packaged in a heated and molten state. As shown in FIG. 1, the packaging form is such that cheese tightly wrapped in a cheese packaging material 1 is packed into a carton consisting of an upper lid 2 and a lower lid 3 made of cardboard. The cheese filling method is as shown in Fig. 2, after a certain amount of molten cheese heated to about 75 to 85°C is filled into a cheese packaging material 1 folded into a carton top lid 2. Fold the remaining part of packaging material 1 that is not folded in so that it is in close contact with the melted cheese, and then attach the bottom lid 3.
Insert. Then, the filled carton is divided into upper and lower parts.
Pressure is applied from the left and right sides to perfect the heat-sealing and sealing properties of the cheese packaging material, completing the packaging of processed cheese. Furthermore, there is also a method shown in FIG. 3 as a method of folding the cheese packaging material 1 into the carton top lid 2. That is, both side portions of the cheese packaging material 1 are pressure-sealed using a pressure sealer shown in FIG. 4, and then inserted into the carton top cover. Due to the filling method described above, the sealing layer of the cheese packaging material must be sealed only by the heat of the filled cheese, or must maintain sufficient sealing performance by pressure sealing. Furthermore, the sealing layer of the cheese packaging material must have excellent wettability to the melted cheese, allowing the melted cheese to flow into every corner of the packaging material folded into the top lid. this is,
This is because if air remains in the corners, mold will grow there. Furthermore, when eating cheese, the packaging material is cut from above with a kitchen knife, knife, etc., so the packaging material for cheese must be easily cut with a kitchen knife, knife, etc. In this way, the sealing layer of packaging materials for cheese requires different performance from the sealing layer of general packaging materials, and the materials conventionally used as packaging materials for cheese are cellophane or moisture-proof cellophane.
Generally, a mixture of polyisobutylene, low molecular weight polyethylene, paraffin wax, Microcris, Talin wax, etc. was applied by heating and melting. When the seal layer used in this cheese packaging material is filled with molten cheese, a portion of the seal layer melts and comes into close contact with the surface of the cheese, and heat sealing and pressure sealing can be performed only by the heat of the molten cheese. However, a special blender is required to mix materials with different softening points and melt viscosities, such as polyisobutylene, low molecular weight polyethylene, paraffin wax, and microcrystalline wax. Because of the high cost, special coating equipment was required. The applied resin is then subjected to pressure,
If the temperature rises, there is a risk of blocking, and the temperature control of the processing atmosphere, handling operations for winding, etc. are complicated. Furthermore, in order to obtain sufficient sealing performance with packaging materials using this mixed resin, the amount of mixed resin applied must be
60-80g/ ^m2 was required. When using this packaging material to fill and package processed cheese as described above, there was a drawback that if too much pressure was applied, the mixed resin would protrude from the sealing part and fuse to the lower lid. Furthermore, when the packaging material is removed from the cheese, a portion of the mixed resin adheres to the cheese. Next, the typical packaging material used for heat-melting filling of yokan is paper/aluminum foil/polyethylene, and is heat-sealed to the bottom in a cylindrical shape with a sealed back. 80-95 in this
Fill with yokan melted at ℃ and heat seal the top in the same way as the bottom. Since this packaging material contains aluminum foil, it has excellent barrier properties and can extend the shelf life to about one year. However, with this filling method, air bubbles in the molten Yokan accumulate at the top, and because of the hermetic sealing method, the shape of the bottom and top of the Yokan is distorted, reducing the commercial value of both sides. In addition, since it contains aluminum foil, it is opaque and the yokan cannot be seen, making it impossible to express the characteristics of chestnut yokan, Ogura yokan, etc. Further, although the surface of the packaging material is patterned by printing or the like, once the package is opened, the contents become patternless. The present invention eliminates the drawbacks of conventional packaging materials for cheese, packaging materials for yokan, etc., and provides a laminated packaging material suitable for hot melt filling, which is extrusion coated using an extruder and provided with a resin layer and a pattern layer. . The resin used in the resin layer of the present invention is an ethylene vinyl acetate copolymer with a vinyl acetate content of 5 to 40 wt%.
Consists of a copolymer (B) of (A), ethylene or α-olefin, and an unsaturated carboxylic acid or its anhydride, the weight ratio of which is (A):(B)=99-60:1- It is 40. Also, if necessary, apply an adhesive to the above resin.
30wt% can be added. . Here, if the vinyl acetate content of the ethylene-vinyl acetate copolymer (A) is 5 wt% or less, heat sealing of the hot melt filling only by heat becomes incomplete, and ethylene or α-olefin and unsaturated carboxylic acid or The anhydride has poor compatibility with the copolymer (B), resulting in poor extrusion coating processability. Furthermore, if the vinyl acetate content is 40 wt% or more, the suitability for extrusion coating is poor, the yield is reduced, and the applied resin film becomes sticky, resulting in poor filling workability with the hot-melt filling. Next, the copolymer (B) of ethylene or α-olefin and unsaturated carboxylic acid or its anhydride will be explained. Ethylene or α-olefin has the general formula
It is a polymer of ethylene having a carbon double bond at the terminal represented by CnH ₂ n, and those in the range of n=2 to 100 showed good results. Especially n=20
~40 range showed good results. As unsaturated carboxylic acids, acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid were effective in the present invention. The molecular weight of the copolymer (B) used in the resin layer of the present invention is determined based on the compatibility with the ethylene-vinyl acetate copolymer, the flow of the hot melt to be filled, and the adhesion with the cooling and solidified filling. It has a large effect, with best results in the 6000-20000 range. It also consists of an ethylene-vinyl acetate copolymer (A) with a vinyl acetate content of 5 to 40 wt% and a copolymer (B) of ethylene or α-olefin and an unsaturated carboxylic acid or its anhydride, and the blending ratio is (A):(B)=99～
60:1 to 40 resin (C) to 3 parts tackifier
~30wt% can be added. By adding a tackifier, not only the heat sealability is further improved, but also sealing can be performed only by pressure at room temperature. Table 1 shows a comparison between a laminated material provided with a resin layer made of a tackifier-free composition and a tackifier-added composition. The composition of the packaging material used here is as follows.

[Table] Fat

[Table] *1 Moisture-proof cellophane = Polyvinylidene chloride-coated cellophane As shown in Table 1, by adding a tackifier, it is possible to press seal the resin layers together using a pressure sealer at room temperature, making it compatible with various packaging formats. can. The tackifier is made of any one of aliphatic hydrocarbon resins, aromatic hydrocarbon resins, copolymerized hydrocarbon resins, or a mixture thereof. The tackifier consists of a resin obtained by adding either a rosin derivative or a modified rosin derivative to the above resin. Here, the aliphatic hydrocarbon resin is obtained by polymerizing a 4- to 5-carbon fraction containing monomers such as pentene isoprene and piperylene (1,3,-pentadiene) produced by thermal decomposition of petroleum naphtha as a raw material. It is a resin that can be used. Aromatic hydrocarbon resins are obtained by polymerizing styrenes, indenes, etc., which are thermal decomposition products of petroleum naphtha, with hydrocarbons mainly having 9 carbon atoms, or pure monomers such as α-methylstyrene, vinyltoluene, etc. It is resin. The copolymerized hydrocarbon resin is a resin obtained by copolymerizing the respective monomers in the aforementioned aliphatic hydrocarbon resin and aromatic hydrocarbon resin. In addition, rosin derivatives and modified rosin derivatives refer to rosin or modified rosin obtained by hydrogenating, disproportionating, and dimerizing rosin.
It is esterified with alcohols such as glycols, glycerin, and pentaerythritol.
The pine tar odor of rosin makes it unsuitable for food packaging materials,
This product has improved browning caused by heating. The resin layer of the present invention can be easily pelletized by heating, melting and mixing using a screw extruder or a Banbury mixer. This pellet is
Extrusion coating can be performed using a general extrusion coating extruder without slipping, surging, or film cracking. The resin layer of conventional cheese packaging materials is formed by heating and melting a mixed resin and melt-applying it onto a base material, so the base material is limited to cellophane or moisture-proof cellophane, which have excellent thermal stability. Furthermore, it was difficult to control the amount of the mixed resin applied, and the application speed was slow. On the other hand, since the resin layer of the present invention can be formed by extrusion coating, it is not limited to cellophane.
It can also be formed into plastic films and other composite materials. Furthermore, the amount of coating can be adjusted very easily by controlling the extrusion amount or coating speed. The resin layer of the present invention has 20 to 45
Sufficient sealing and sealing performance can be obtained with a coating amount of g/m ² , and the resin seals completely due to the heat of the filling material and the pressure applied, but there is a risk that the resin may protrude from the sealed area due to these factors. There is no. Furthermore, the problem of the resin layer adhering to the filling when the package is opened, which is caused by the resin layer's weak cohesive force, has also been resolved. Furthermore, the edible ink of the pattern layer of the present invention uses an alcohol-soluble resin as a binder,
The specific composition is as shown below. Polyvinylpyrrolidone Monaska Threaded Ethyl Alcohol Water Sierra Lemonas Threaded Ethyl Alcohol Water Here, as the food coloring, other than the above-mentioned examples can be used as long as it is used for food. Furthermore, unless ethyl alcohol is used with a purity of 90% or higher, water will be present between the ethyl alcohol and the contents, resulting in poor transfer. Since a pattern layer is provided on the resin layer with the above-mentioned composition using the above-mentioned edible ink, for example, when molten cheese is packaged, the cheese will be damaged by the heat until the cheese is cooled and solidified and by the external pressure during packaging. The pattern layer is transferred. Here, when the content is cheese, if a protein component is further added to the edible ink, the pattern layer can be better transferred to the content. Next, examples of the present invention will be described. Example 1 Polyvinylidene chloride coated cellophane (25μ)
A resin layer with the following composition is extruded onto the top at approximately 150°C to form a resin layer, and then a pattern layer is formed on the resin layer by gravure printing using an edible ink with the composition below, and the packaging material is coated. Obtained.

[Table] Water The packaging material obtained in this way was filled and packaged with processed cheese with a heated melting temperature of 85℃ using the method described above, and after pressurizing from the top and bottom and left and right sides for about 1 hour, it was left in the refrigerator for 2 hours. did. As a result, a processed cheese package with excellent adhesion between the packaging material and the cheese and with much better transparency than before was obtained. Further, cutting with a knife was easy, no elongation of the resin layer was observed, and when slicing into thin slices, there was no shift of the packaging material, causing no problems. In addition, in order to examine the sealability, the processed cheese package was immersed in a 0.3% methylene blue water-methanol (water/methanol = 1/1) solution for 5 hours, and then opened and the coloring of the cheese was observed. was not seen at all. Furthermore, after being stored in a constant temperature and humidity room at 20° C. and 50% RH for two months, the condition of the processed cheese was examined and found to be in a sufficiently satisfactory condition with no mold growth or loss of moisture. Furthermore, when the package was opened, the pattern layer of the packaging material was transferred to the cheese, creating a red pattern on the cheese. Example 2 A resin layer having the following composition was extruded onto a polyvinylidene chloride coated polyethylene terephthalate film (12μ) at approximately 150°C to form a resin layer.
Furthermore, using the same ink as in Example 1, a pattern layer was similarly provided to obtain a packaging material.

[Table] The packaging material obtained in this way is filled with kneaded yokan with a heating melting temperature of 105°C and packaged using the method described above.
After applying pressure from the top and bottom and from the left and right for about 1 hour, it was left in the refrigerator for 2 hours. As a result, a Yokan package was obtained which had no leakage or oozing of Yokan, had good transparency, and was very effective as a product. It was also easy to cut with a knife. Further 25℃−60%
There was no change in the color or taste of the yokan even after 6 months of storage in a constant RH temperature and humidity room, and of course there was no decrease in moisture content. A red pattern was transferred to the surface of the yokan when it was opened. As described above, the present invention uses an ethylene vinyl acetate copolymer that can be extrusion coated to form a resin layer of a packaging material for a product to be filled by heating and melting, and ethylene or α
A composition consisting of a copolymer of olefin and an unsaturated carboxylic acid or its anhydride, or a copolymer of ethylene-vinyl acetate copolymer, ethylene or α-olefin and an unsaturated carboxylic acid or its anhydride, and a tackifier By creating a composition consisting of the There is no need for any equipment, and the resin layer can be provided using general-purpose equipment. Since the pattern layer is formed using an edible ink using an alcohol-soluble resin as a binder, it has excellent adhesion to the contents, and moreover, the pattern layer of the packaging material can be reliably transferred to the contents. Additional Relationships The present invention provides a pattern layer made of edible ink with an alcohol-soluble resin as a binder on the resin layer of a laminated packaging material made of a base film and a resin layer as disclosed in No. 1347236 (Japanese Patent Publication No. 61-12825). packaging material. Similar to the original patent application, the packaging material of the present invention has excellent thermal sealing of the contents, adhesion to the contents, and sealing performance, and is easy to peel off when opening the package. This makes it possible to transfer the contents of

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a processed cheese package, FIGS. 2 and 3 are explanatory diagrams showing a process for producing processed cheese, and FIG. 4 is an explanatory diagram of a pressure-sealing method. 1...Packaging material, 2...Top lid, 3...Bottom lid, 4
...Foldable type.

Claims (1)

[Claims] 1. A base film containing an ethylene-vinyl acetate copolymer (A) having a vinyl acetate content of 5 to 40% by weight, ethylene or α-olefin, and an unsaturated carboxylic acid or its anhydride. A resin layer consisting of a polymer (B) and a weight ratio of (A):(B) of 99 to 60:1 to 40 is provided, and a pattern layer consisting of an edible ink with an alcohol-soluble resin as a binder is provided. Laminated packaging material. 2 A base film containing an ethylene-vinyl acetate copolymer (A) with a vinyl acetate content of 5 to 40% by weight, and a copolymer (B) of ethylene or α-olefin and an unsaturated carboxylic acid or its anhydride. Resin (C) and tackifier, consisting of (A):(B) in a weight ratio of 99-60:1-40
(D) in a weight ratio of (C):(D)=97-70:3-30, and a pattern layer made of edible ink with an alcohol-soluble resin as a binder. packaging materials. 3. The laminated packaging material according to claim 2, wherein the tackifier is one of aliphatic hydrocarbon resins, aromatic hydrocarbon resins, or copolymerized hydrocarbon resins, or a mixed resin thereof. 4 Claims in which the tackifier is a resin made by adding a rosin derivative or a modified rosin derivative to one of aliphatic hydrocarbon resins, aromatic hydrocarbon resins, or copolymerized hydrocarbon resins, or a mixed resin thereof Laminated packaging material according to item 2.