JP4090727B2 - Retort food packaging laminate - Google Patents

Description

【００３８】
（実験１：柚子肌適性試験）
実施例１および比較例１〜２で得られた積層体１０を、１３０ｍｍ×１７０ｍｍの大きさに２枚切り取り、ＣＰＰを相対向するように配置し、縦２辺、横１辺を１０ｍｍ幅で熱圧着（条件２００℃、２ｋｇ／ｃｍ²、０．５秒）し、食品包装用積層袋を得た。次いで、カレー１５０ｇを充填し、１２０℃で、３０分のレトルト殺菌を実施した。
【００３９】
レトルト殺菌を実施し、冷却後、積層体１０の表面における柚子肌の発生状態を目視で、以下の基準を設け、良好、不良の２段階で評価した。結果を表２に示す。
良好・・・柚子肌の発生が全く観察されず、表面状態が良好
不良・・・柚子肌の発生が全面に観察され、表面状態が不良
【００４０】
（実験２：内容物取り出しやすさ）
実施例１および比較例１〜２で得られた積層体１０を、１３０ｍｍ×１７０ｍｍの大きさに２枚切り取り、ＣＰＰを相対向するように配置し、縦２辺、横１辺を１０ｍｍ幅で熱圧着（条件２００℃、２ｋｇ／ｃｍ²、０．５秒）し、シール部にノッチを入れ、食品包装用袋を得た。ここで、ノッチとはカットの切り口である。次いで、カレー１５０ｇを充填し、開口辺を熱圧着（条件２００℃、２ｋｇ／ｃｍ²、０．５秒）し、１２０℃で、３０分のレトルト殺菌を実施した。
【００４１】
レトルト殺菌を実施した後、ノッチ部の両端を両手で持ち、前後に引っ張りながら引き裂き、カット面を下にして食品包装用袋から内容物を取り出した。食品包装用袋からの内容物の取り出し易さを、以下の基準を設け、良好、不良の２段階で評価した。結果を表２に示す。
良好・・・内容物が、食品包装用袋の内面に付着していない（残留物なし）
不良・・・内容物が、食品包装用袋の内面に付着している（残留物あり）
【００４２】
（実験３：ヒートシール強度試験）
実施例１および比較例１〜２で得られた積層体を、１３０ｍｍ×１７０ｍｍの大きさに２枚切り取り、ＣＰＰを相対向するように配置し、縦２辺、横１辺を１０ｍｍ幅で熱圧着（条件２００℃、２ｋｇ／ｃｍ²、０．５秒）して食品包装様積層袋を得た。次いで、カレー１５０ｇを充填し、１２０℃で、３０分のレトルト殺菌を実施した。
【００４３】
レトルト殺菌を実施した後、ＭＤ方向、および、ＴＤ方向のヒートシール強度をそれぞれ測定した。ここで、ＭＤ方向とは、プロピレン−エチレンブロック共重合体を主成分とする樹脂組成物を押出し成形する時のフィルムの送り方向である。ＴＤ方向は、ＭＤ方向と直角の方向である。ＭＤ方向のヒートシール強度は、レトルト食品包装用袋の縦辺のヒートシール部を含んだ試験片を幅１５ｍｍで切出し、これをＭＤ方向と平行に、引張ることによって測定される。また、ＴＤ方向のヒートシール強度は、横辺のヒートシール部を含んだ試験片を幅１５ｍｍで切り出し、これをＴＤ方向と平行に引張ることによって測定される。したがって、長さ１０ｍｍ、幅１５ｍｍのシール部を、長さ方向に沿って引っ張った時のシール強度が測定される。
【００４４】
ヒートシール強度は、引張試験機（オリエンテック社製）を用いて、３００ｍｍ／分の引張速度で測定した。結果を表２に示す。なお、表２中には、１５ｍｍ当たりのヒートシール強度（単位：ｇ／１５ｍｍ）を記載した。
【００４５】
（実験４：開口性試験）
実施例１および比較例１〜２で得られた積層体１０を、１３０ｍｍ×１７０ｍｍの大きさに２枚切り取り、ＣＰＰを相対向するように配置し、縦２辺、横１辺を１０ｍｍ幅で熱圧着（条件２００℃、２ｋｇ／ｃｍ²、０．５秒）し、レトルト食品包装用袋を得た。
【００４６】
開口性は、レトルト食品包装用袋の開口部を指で開き、下記基準に従い、良好、不良の２段階で評価した。結果を表２に示す。
良好…指で容易に開く
不良…フィルム表面にベタツキを生じ、ブロッキングが発生している
【００４７】
（実験５：落袋試験）実施例１および比較例１〜２で得られた積層体を、１３０ｍｍ×１７０ｍｍの大きさに２枚切り取り、ＣＰＰを相対向するように配置し、縦２辺、横１辺を１０ｍｍ幅で熱圧着（条件２００℃、２ｋｇ／ｃｍ²、０．５秒）してレトルト食品包装用袋を得た。次いで、カレー１５０ｇを充填し、１２０℃、３０分でレトルト殺菌を実施した。
【００４８】
レトルト殺菌を実施した後、３℃にて一週間冷蔵保存した。冷蔵保存後のサンプルを１３０ｍｍの面が下になるようにして、コンクリートの床上１５０ｃｍの高さから、連続で１０回の垂直落下を行った後、破袋の有無を確認した。結果を表２に示す。なお、表２中には、破袋数／ｎ（ｎ：落袋試験に用いた袋の数）を記載した。
【００４９】
（実験結果）
【表２】

【００５０】
表２に示した実験１〜５の結果から明らかなように、本発明のレトルト食品包装用積層体から得られた袋は、耐熱性、耐寒衝撃性を保持しつつ、従来品に比して、レトルトパウチの表面に微細な凹凸の発生もなく、外観に優れ、また、開口性、食品衛生性、簡便性（内容物取り出し易さ）にも優れており、産業上寄与すること大である。
【００５１】
【発明の効果】
以上説明したように、本発明のレトルト食品包装用積層体によれば、本発明のヒートシール性フィルムに、上述したようなフッ素化炭素構造を有する化合物の微粉末を練り込んだ樹脂組成物を製膜したヒートシール性フィルムを使用することにより、食品に接する層の表面の着油性が防止される。
このため、加熱殺菌の際発生する、表面の微細な凹凸による外観不良、いわゆる柚子肌を防止した積層体を提供することができる。
【００５２】
また、本発明のヒートシール性フィルムの製膜工程において、ダスティング工程を施さないため、衛生的なレトルト食品包装用積層体を提供することができる。
【００５３】
また、本発明のレトルト食品包装用積層体の食品に接する層が、離形性能に非常に優れているため、フィルム開口性に優れたレトルト食品包装用袋を提供することができる。
【００５４】
本発明のレトルト食品包装用積層体の食品に接する層が、非粘着性であるため、消費者が、上記のような内容物を袋から取り出す際、内容物をスムーズに取り出すことができるレトルト食品包装用袋を提供できる。
【００５５】
以上説明したように、本発明のヒートシール性フィルムを基材フィルムに積層して使用することにより、寒冷地での保存・流通においても問題なく、耐柚子肌性、開口性、食品衛生性に非常に優れ、しかも、消費者が内容物を取り出しやすいレトルト食品包装用袋を提供することができる。
【図面の簡単な説明】
【図１】本発明のレトルト食品包装用積層体の一例を示す断面図である。
【図２】本発明の別態様のレトルト食品包装用積層体の一例を示す断面図である。
【図３】本発明の更に別態様のレトルト食品包装用積層体の一例を示す断面図である。
【図４】本発明のなおまた別態様のレトルト食品包装用積層体の一例を示す断面図である。
【符号の説明】
１ 基材フィルム
１１ 印刷層
２ 接着剤層
３ ヒートシール性フィルム
３１ ラミネート側の層
３２ 食品に接する層
３３ フッ素系樹脂の微粒子
４ 機能性フィルム
４１ 二軸延伸ナイロンフィルム
４２ アルミニウム箔
１０ レトルト食品包装用積層体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminate for retort food packaging.
More specifically, it is a laminate composed of a heat-sealable film mainly composed of propylene resin, improved in appearance, openability, and ease of taking out contents and a base film, and includes a retort food packaging bag. The present invention relates to a laminate for retort food packaging useful for manufacturing.
[0002]
[Prior art]
Processed foods include canned foods, bottled foods, frozen foods, retort foods, and the like, and in recent years, the demand has been increasing rapidly. Among them, retort food has been widely used in general households, restaurants and the like.
According to the Japanese Agricultural Standards, “Retort food is a plastic film or metal foil, or a container made of a combination of these layers in a bag or other shape (limited to those with confidentiality and light-shielding properties). It is defined as "stuffed with cooked food, sealed by heat melting and pasteurized under heat and pressure".
[0003]
Conventionally, a film using a laminate composed of a heat-sealable film mainly composed of propylene resin and a base film is widely known as a material for making a retort food packaging bag (hereinafter also referred to as “retort pouch”). Yes.
Moreover, since the laminated film used for the retort food packaging bag is generally a thin film having a thickness of 150 μm or less, it has no rigidity and generally has a poor sliding property.
For this reason, as a means of improving slipperiness, conventionally, when performing lamination processing, a dusting (spraying) step of spraying fine starch powder released on the surface is performed to give slipperiness on the surface of the film. Has been done.
As the fine starch powder used in the dusting step, starch particles having a particle size of about 5 to 10 μm are generally used. In addition to the surface of the laminate immediately after processing, the laminate has a lubricant function when contacting the machine when performing lamination processing.
Therefore, the present invention is very effective for solving problems caused by slipping failure such as wrinkling at the time of winding of the laminate, cutting position failure, running failure, folding failure, and the like.
[0004]
[Problems to be solved by the invention]
However, in foods that contain a large amount of oil and fat components in the contents, particularly in a retort treatment heated at 100 to 135 degrees, an unstretched polypropylene film (hereinafter referred to as “CCP”) in a layer in contact with the food causes the oil and fat components to be uneven. When absorbed and swollen, the surface of the retort pouch after retort may generate fine irregularities, so-called cocoon skin, which may deteriorate the appearance.
Conventionally, as a technique for preventing the cocoon skin phenomenon, JP-A-54-120085 discloses a technique for inhibiting the absorption of oil by increasing the density of propylene resin and increasing the crystallinity. There is a problem that the effect of preventing the phenomenon is not sufficient, the cold shock resistance of the heat-sealable film is impaired, and the bag drop strength is inferior.
In addition, as a technique for the polypropylene film to absorb oil content uniformly, there is JP-A 2000-256532 as a technique for intentionally kneading an ethylene component having high oil absorption, although an inhibitory effect on cocoon skin has been recognized. There is a problem that the heat seal strength after retort sterilization is extremely reduced.
[0005]
However, the dusting agent used in the process of laminating films has a sanitary problem due to the mixing of microorganisms into the particles.
Further, the dusting agent is squeezed off and deposited around the machine in a portion where the film is in frictional contact in a bag making machine or a filling machine. And since the said deposit of dusting agent becomes a lump and may mix in the bag for retort food packaging, there exists a problem on hygiene.
[0006]
In addition, the retort food packaging bag has a problem that when the consumer ingests and uses the contents, the viscous contents such as curry are stuck in the bag and are difficult to take out.
[0007]
[Means for Solving the Problems]
Therefore, in order to solve the above-mentioned problems, the present inventors have devised a retort characterized by containing a fine powder of fluororesin in a layer in contact with food without using a dusting agent as a result of intensive research. The laminated body for food packaging has found excellent appearance, openability, and ease of taking out the contents.
The present invention relates to a food packaging in which a laminate comprising a heat-sealable film and a base film made of a resin composition containing at least a propylene resin as a main component is formed into a bag shape so that the heat-sealable film is on the inside. In the bag, the resin composition containing propylene resin as a main component is composed of at least two layers, ie, a layer (A) on the laminate side and a layer (B) in contact with food, and the layer (B) in contact with food. Can provide the thing concerning the laminated body for retort food packaging characterized by including the fine powder of a fluororesin.
In the above, the fluororesin is composed of a tetrafluorinated resin and / or a compound having a trifluorinated carbon structure at least in either the side chain or the main chain terminal, and the laminate for retort food packaging Can also be provided.
In addition, the layer (B) in contact with the food is a retort comprising a resin containing 0.1 to 10 parts by weight of a fine powder of fluororesin with respect to 100 parts by weight of propylene resin. A laminate for food packaging can also be provided.
In addition, as the heat-sealable film, a laminate for retort food packaging comprising a multilayer film obtained by coextrusion of at least two layers of a laminate side layer (A) and a layer in contact with food (B) Can be provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be specifically described below.
[0009]
FIG. 1 is a cross-sectional view showing an example of a laminated body for retort food packaging according to the present invention. The laminated body 10 for retort food packaging has an adhesive layer comprising a base film 1 on which printing has been performed and a heat-sealable film 3 made of an unstretched film of a polypropylene film mainly composed of a propylene-ethylene block copolymer resin. 2 are stacked. The heat-sealable film 3 is composed of a laminated film in which a laminate-side layer 31 and a layer 32 in contact with food containing a fine powder 33 of a fluororesin are laminated.
[0010]
FIG. 2 is a cross-sectional view showing an example of a laminated body for retort food packaging according to another aspect of the present invention. The laminated body 10 laminated | stacked the biaxially stretched nylon film 41 (functional film) on the biaxially stretched polyethylene terephthalate film (base film 1) which performed printing using the adhesive agent 2. FIG. Furthermore, the heat-sealable film 3 used in FIG. 1 and a biaxially stretched nylon film 41 are constituted by a laminated film laminated with an adhesive 2 interposed therebetween.
[0011]
FIG. 3 is a cross-sectional view showing an example of a laminated body for retort food packaging according to still another aspect of the present invention. The laminated body 10 laminated | stacked the aluminum foil 42 (functional film) using the adhesive agent 2 on the biaxially-stretched polyethylene terephthalate film (base film 1) which performed printing. Furthermore, it is comprised by the laminated film which laminated | stacked the heat-sealable film 3 and aluminum foil 42 which were used in FIG.
[0012]
FIG. 4 is a cross-sectional view showing an example of a laminate for retort food packaging according to still another aspect of the present invention. The laminate 10 is a laminate of a printed biaxially stretched polyethylene terephthalate film (base film 1), a biaxially stretched nylon film 41, and a functional film 4 made of aluminum foil, in order, with an adhesive 2 interposed therebetween. did. Furthermore, the heat-sealable film 3 used in FIG. 1 and the functional film 4 are constituted by a laminated film laminated with an adhesive 2 interposed therebetween.
[0013]
In the present invention, the base film 1 constituting the laminate for retort food packaging according to the present invention has a heat resistance that can withstand heat during heat sealing and a physical impact from the outside after packaging. The material of the base film 1 includes a polyethylene terephthalate film (hereinafter referred to as “PET film”), a polybutylene terephthalate film, and the like. Polyamide films such as polyester film, polypropylene film (hereinafter also referred to as “PP film”), 6 nylon film, and 6,6 nylon film can be suitably used. In general, a material that is further improved in heat resistance and impact resistance by biaxial stretching is used. Although the thickness of the base film 1 is not particularly limited, a thickness of 5 to 20 μm is usually used. Further, a metal or a metal oxide may be vapor-deposited on these base film 1 as necessary. You may print on the surface of the base film 1, and / or the back surface as needed.
[0014]
As the heat-sealable film 3 constituting the laminate for retort food packaging according to the present invention, an unstretched polypropylene film (hereinafter referred to as “CCP”) such as propylene-ethylene random copolymer, propylene-ethylene block copolymer, and high-density polyethylene. ")").
Among these, a propylene-ethylene block copolymer (hereinafter also referred to as “BPP”) has a heat resistance of 120 to 135 ° C. during retort treatment, and a heat seal temperature is moderately low. CCP which is a copolymer can be used suitably.
As the CCP, a propylene-ethylene block copolymer having excellent oil resistance and high crystallinity can be suitably used.
Moreover, as said CCP, the film formed from the resin composition which added rubber components, such as an ethylene-butene-1 copolymer, to the propylene-ethylene block copolymer can also be used as needed.
[0015]
In a preferred embodiment of the present invention, the heat-sealable film 3 constituting the retort food packaging laminate according to the present invention needs to have a two-layer configuration of a layer 31 on the laminate side and a layer 32 in contact with the food, The total layer thickness is preferably 50 to 100 μm, and the layer thickness of the layer 32 in contact with the food is preferably 2 μm or more, more preferably 2 to 10 μm. However, when the fluororesin powder is contained in all layers of the heat-sealable film 3, the laminate strength becomes insufficient. In addition, it is economically inferior to make the layer thickness more than necessary because an extra fluororesin is used.
[0016]
Tetrafluorinated resin and / or a compound having a trifluorinated carbon structure at least in either the side chain or the main chain end for the purpose of imparting oil prevention and non-adhesiveness to the layer 32 in contact with the food. It is necessary to use a film formed from a polypropylene resin composition kneaded with a fine powder containing.
The fine powder composed of the fluorinated resin may be a fine powder composed of a fluorine resin oligomer, or a fine powder composed of a composition formed by drying the surface of the antiblocking agent after liquid coating with a fluorine resin.
[0017]
The fluororesin contained in the fine powder kneaded in the layer 32 in contact with the food is excellent in oil resistance, non-adhesiveness, and heat resistance.
Examples of the fluororesin used in the present invention include polytetrafluoroethylene (hereinafter also referred to as “PTFE”), tetrafluoroethylene / hexafluoropropylene (FEP), tetrafluoroethylene / ethylene copolymer (ETFE), and the like. It is commercially available and can be suitably used. Among these, polytetrafluoroethylene (PTFE), which is a typical fluorinated resin, is particularly excellent in oil-preventing property, non-adhesiveness, and heat resistance, and can be particularly preferably used.
[0018]
The particle size of the fine powder made of the fluororesin kneaded in the layer 32 in contact with the food is 1 to 15 μm, preferably 2 to 4 μm.
The fine powder made of the fluorine-based resin may be contained in an amount of 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of polypropylene.
If the content is less than 0.1 parts by weight, the suitability of the cocoon skin is insufficient, and if it exceeds 10 parts by weight, the heat seal strength becomes insufficient and the economy is inferior.
[0019]
The anti-blocking agent added to the layer 32 in contact with the food is fine particles made of inorganic substances such as silica, talc, zeolite, diatomaceous earth, and organic substances such as silicone resin, polystyrene resin, and polymethyl methacrylate resin. It is the fine particle which consists of.
When added to the film, the anti-blocking agent forms an uneven shape on the surface of the film, reduces the contact area, and acts to prevent adhesion (blocking) of the film.
[0020]
In addition to kneading the anti-blocking agent into the layer 32 in contact with the food, a fatty acid amide slip agent can be used. The slip agent can also be deposited on the surface of the film in a thin film to give a slip action.
[0021]
In the laminate for retort food packaging according to the present invention, another functional film 4 can be laminated as necessary. For example, either one or both of an oxygen barrier layer and a shock absorbing resin layer can be provided. Further, several layers of these layers can be provided. As the oxygen barrier layer, an aluminum foil having a thickness of 5 to 9 μm is generally used. However, it is also possible to use a film obtained by depositing an inorganic substance such as a coating of vinylidene chloride resin, aluminum, alumina oxide or silicon oxide. it can. As the shock absorbing resin layer, a nylon film is preferably used. The nylon film can be suitably used regardless of whether it is uniaxially stretched, biaxially stretched or unstretched. The thickness of the impact-absorbing resin layer is not particularly limited, but is usually 5 to 40 μm, preferably 10 to 30 μm.
[0022]
Next, the manufacturing method of the heat-sealable film 3 of this invention is demonstrated.
[0023]
In order to obtain the heat-sealable film 3 of the present invention, it consists of CCP containing CCP and a fine powder of a fluororesin, and two types of resins may be produced by, for example, a film forming method by coextrusion, You may manufacture by a film lamination molding method. More specifically, the film forming method by co-extrusion includes a co-extrusion T-die method, a co-extrusion inflation method, a co-extrusion lamination method, and the like. More specifically, the film lamination forming method is a dry lamination method. Is mentioned.
[0024]
Among these forming methods, a film forming method by coextrusion is preferable. In this co-extrusion method, unlike the film lamination method, it is not necessary to dry the solvent in the adhesive used at the time of processing, a solvent drying step is unnecessary, and the productivity is superior to film lamination.
[0025]
A known additive such as an antioxidant, an antistatic agent, or a coloring agent may be added to the resin forming each layer of the laminate for retort food packaging 10 as long as the achievement of the object of the present invention is not hindered. Can do. As the adhesive for laminating each film, a urethane-based adhesive is preferably used. However, other adhesives can be used as long as they are known and have no sanitary problems.
[0026]
Next, in the present invention, a description will be given of a method for making a bag or a box using the laminated body 10 for retort food packaging. For example, when the packaging container is a flexible packaging bag made of a plastic film or the like, Using the laminated body for retort food packaging manufactured by the above method, the surface of the heat-sealable film facing the food is faced and folded, or two of them are overlapped, and the periphery The end can be heat sealed to provide a seal portion to form a bag. Thus, as the bag-making method, the above-mentioned laminated body for retort food packaging is folded with the surface of the layer in contact with the food of the heat-sealable film facing each other, or two of them are overlapped, Further, the peripheral edge of the outer periphery is, for example, a side seal type, a two-sided seal type, a three-sided seal type, a four-sided seal type, an envelope-attached seal type, a joint-attached seal type ( (Peel seal type), pleated seal type, flat bottom seal type, square bottom seal type, etc. Various forms of packaging containers can be produced. In addition, for example, it is possible to manufacture a self-supporting packaging bag (standing pouch) or the like. Further, in the present invention, a tube container or the like is manufactured using the above-described laminated body for retort food packaging. Can do.
[0027]
In the above, as the heat seal method, for example, a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, an ultrasonic seal and the like are known. It can be done by the method. In the present invention, a spout such as a one-piece type, a two-piece type, or the like, or a zipper for opening and closing can be arbitrarily attached to the packaging container as described above.
[0028]
In the present invention, the retort food packaging bag produced as described above can seal and sterilize a wide variety of foods.
Examples of foods that are particularly suitable for filling and sealing the above retort food packaging bags include curry, stew and other retort foods, seasonings such as miso, konjac, chikuwa, koji and other paste products, ham, sausages, etc. Smoked products, cooked foods such as meatballs and hamburgers, processed fishery products, pickles, boiled simmered foods, liquid and viscous foods and beverages.
[0029]
In the present invention, the retort food packaging bag produced as described above is filled with food and packaged, for example, in a retort kettle, temperature 200 ° C., pressure 2 kg / cm. ² Even if it is retorted for 30 minutes and subjected to harsh sterilization treatment, a packaging product that is excellent in appearance, hygienic, excellent in openability, and easy to take out food without generating fine irregularities on the bag surface. It can be obtained.
[0030]
【Example】
Hereinafter, the present invention will be described with reference to examples.
[0031]
(Example 1) Polypropylene resin in Table 1 and polytetrafluoroethylene wax having a particle diameter of 2 μm were added in the proportions shown in Table 1, and using an extruder (caliber 150 mmΦ, 75 mmΦ), the temperature in a T die was 250 ° C. In Table 1, the resin of the layer (A) on the laminate side in Table 1 is 150 mmΦ, the resin in the layer (B) in contact with food is 75 mmΦ, and melt coextrusion is performed from the T die so that the layer ratio in Table 1 is obtained. A CPP having a thickness of 70 μm, which is a sealing film 3, was obtained.
[0032]
Gravure printing is performed on a biaxially stretched PET film (base film 1) with a thickness of 12 μm using four colors of urethane printing ink (black, red, indigo, and yellow). -Based adhesive 2 coating amount is 3.5 g / m ² Then, an aluminum foil (functional film 4) having a thickness of 7 μm was sequentially dry laminated.
Furthermore, the CPP film (heat-sealable film 3) having a thickness of 70 μm obtained above is laminated by dry lamination, and consists of PET film / gravure printing layer / adhesive layer / aluminum foil / adhesive layer / heat-sealable film. A laminate 10 was obtained. In this step, the treatment with the dusting agent performed in the normal step was not performed.
[0033]
The kind of resin in the Example of this invention is shown.
Aluminum foil: JIS 1N30 (manufactured by Nippon Foil Co., Ltd.)
PET film: Trade name “Lumirror P60” (manufactured by Toray Industries, Inc.)
Urethane adhesive: Trade name “A515 / A50” (Mitsui Takeda Chemical Co., Ltd.)
[0034]
(Comparative example 1) Gravure printing was performed on a biaxially stretched PET film (base film 1) having a thickness of 12 μm using four colors of urethane printing ink (black, red, indigo, yellow), and on the printed pattern layer side, The coating amount of the two-component curable urethane adhesive 2 is 3.5 g / m ² Then, an aluminum foil (functional film 4) having a thickness of 7 μm was sequentially dry laminated. Further, a 70 μm thick CPP film (heat-sealable film 3) composed of the ethylene-propylene block copolymer of Table 1 is laminated by dry lamination, and PET film / gravure printing layer / adhesive layer / aluminum foil / adhesive The laminated body 10 which consists of a layer / heat-sealable film was obtained.
In this step, the treatment with the dusting agent performed in the normal step was not performed. Further, no polytetrafluoroethylene wax was added in the process of producing the polypropylene resin.
[0035]
(Comparative example 2) The polypropylene resin of Table 1 and the polytetrafluoroethylene wax with a particle size of 2 micrometers were added in the ratio shown in Table 1, and like Example 1, CPP with a thickness of 70 micrometers which is a heat-sealable film was added. Obtained.
[0036]
Gravure printing is performed on a biaxially stretched PET film (base film 1) with a thickness of 12 μm using four colors of urethane printing ink (black, red, indigo, and yellow). -Based adhesive 2 3.5 g / m ² Then, an aluminum foil (functional film 4) having a thickness of 7 μm was sequentially dry laminated.
Furthermore, the CPP film (heat-sealable film 3) having a thickness of 70 μm obtained above is laminated by dry lamination, and consists of PET film / gravure printing layer / adhesive layer / aluminum foil / adhesive layer / heat-sealable film. A laminate 10 was obtained. In this step, the treatment with the dusting agent performed in the normal step was not performed.
[0037]
[Table 1]

[0038]
(Experiment 1: Eggplant skin suitability test)
Two laminates 10 obtained in Example 1 and Comparative Examples 1 and 2 were cut into a size of 130 mm × 170 mm, CPPs were arranged so as to face each other, and two vertical sides and one horizontal side were 10 mm wide. Thermocompression bonding (conditions 200 ° C, 2 kg / cm ² 0.5 seconds) to obtain a laminated bag for food packaging. Next, 150 g of curry was charged, and retort sterilization was performed at 120 ° C. for 30 minutes.
[0039]
Retort sterilization was performed, and after cooling, the state of occurrence of cocoon skin on the surface of the laminate 10 was visually evaluated, and the following criteria were set and evaluated in two stages, good and bad. The results are shown in Table 2.
Good: No cocoon skin was observed and the surface condition was good
Defects: The occurrence of cocoon skin is observed over the entire surface, and the surface condition is poor.
[0040]
(Experiment 2: Ease of removing contents)
Two laminates 10 obtained in Example 1 and Comparative Examples 1 and 2 were cut into a size of 130 mm × 170 mm, CPPs were arranged so as to face each other, and two vertical sides and one horizontal side were 10 mm wide. Thermocompression bonding (conditions 200 ° C, 2 kg / cm ² 0.5 seconds), and a notch was made in the seal portion to obtain a food packaging bag. Here, the notch is a cut end. Next, 150 g of curry is filled, and the opening side is subjected to thermocompression bonding (conditions 200 ° C., 2 kg / cm ² 0.5 seconds), and retort sterilization was performed at 120 ° C. for 30 minutes.
[0041]
After carrying out retort sterilization, both ends of the notch were held with both hands, and were torn while pulling back and forth, and the contents were taken out from the food packaging bag with the cut surface down. The ease of taking out the contents from the food packaging bag was evaluated according to the following two criteria: good and bad. The results are shown in Table 2.
Good: The contents are not attached to the inner surface of the food packaging bag (no residue)
Defective content is attached to the inner surface of the food packaging bag (with residue)
[0042]
(Experiment 3: Heat seal strength test)
The laminates obtained in Example 1 and Comparative Examples 1 and 2 were cut into two pieces having a size of 130 mm × 170 mm, CPPs were arranged so as to face each other, and two vertical sides and one horizontal side were heated to a width of 10 mm. Crimping (conditions 200 ° C., 2 kg / cm ² 0.5 seconds) to obtain a food packaging-like laminated bag. Next, 150 g of curry was charged, and retort sterilization was performed at 120 ° C. for 30 minutes.
[0043]
After retort sterilization, the heat seal strengths in the MD direction and TD direction were measured. Here, the MD direction is a film feeding direction when a resin composition containing a propylene-ethylene block copolymer as a main component is extruded. The TD direction is a direction perpendicular to the MD direction. The heat seal strength in the MD direction is measured by cutting out a test piece including a heat seal portion on the vertical side of the retort food packaging bag with a width of 15 mm and pulling it in parallel with the MD direction. Further, the heat seal strength in the TD direction is measured by cutting a test piece including a heat seal portion on the lateral side with a width of 15 mm and pulling the test piece in parallel with the TD direction. Therefore, the seal strength when a seal portion having a length of 10 mm and a width of 15 mm is pulled along the length direction is measured.
[0044]
The heat seal strength was measured at a tensile speed of 300 mm / min using a tensile tester (manufactured by Orientec). The results are shown in Table 2. In Table 2, the heat seal strength per 15 mm (unit: g / 15 mm) is shown.
[0045]
(Experiment 4: Openness test)
Two laminates 10 obtained in Example 1 and Comparative Examples 1 and 2 were cut into a size of 130 mm × 170 mm, CPPs were arranged so as to face each other, and two vertical sides and one horizontal side were 10 mm wide. Thermocompression bonding (conditions 200 ° C, 2 kg / cm ² 0.5 seconds) to obtain a retort food packaging bag.
[0046]
The openability was evaluated in two stages, good and bad, by opening the opening of the retort food packaging bag with a finger and following the criteria below. The results are shown in Table 2.
Good… Easily open with your finger
Defects: The film surface is sticky and blocking has occurred
[0047]
(Experiment 5: Dropping bag test) The laminates obtained in Example 1 and Comparative Examples 1 and 2 were cut into two pieces having a size of 130 mm x 170 mm, and the CPPs were arranged so as to face each other. One side is thermocompression bonded with a width of 10 mm (conditions: 200 ° C., 2 kg / cm ² 0.5 seconds) to obtain a retort food packaging bag. Next, 150 g of curry was filled, and retort sterilization was performed at 120 ° C. for 30 minutes.
[0048]
After carrying out retort sterilization, it was refrigerated at 3 ° C. for one week. The sample after refrigerated storage was subjected to 10 vertical drops continuously from a height of 150 cm above the concrete floor with the 130 mm face down, and then checked for the presence of broken bags. The results are shown in Table 2. In Table 2, the number of broken bags / n (n: the number of bags used in the bag drop test) is shown.
[0049]
(Experimental result)
[Table 2]

[0050]
As is clear from the results of Experiments 1 to 5 shown in Table 2, the bag obtained from the retort food packaging laminate of the present invention retains heat resistance and cold shock resistance, as compared to conventional products. The surface of the retort pouch does not have fine irregularities, has an excellent appearance, and has excellent opening, food hygiene, and convenience (easy to take out the contents), contributing greatly to the industry. .
[0051]
【The invention's effect】
As described above, according to the laminate for retort food packaging of the present invention, the resin composition obtained by kneading the fine powder of the compound having a fluorinated carbon structure as described above into the heat-sealable film of the present invention. By using the heat-sealable film thus formed, oiliness of the surface of the layer in contact with food is prevented.
For this reason, the laminated body which prevented the appearance defect by the fine unevenness | corrugation of the surface which generate | occur | produces in the case of heat sterilization, and what is called a cocoon skin can be provided.
[0052]
Moreover, since the dusting process is not performed in the film forming process of the heat-sealable film of the present invention, a sanitary laminate for retort food packaging can be provided.
[0053]
Moreover, since the layer which contacts the foodstuff of the laminated body for retort food packaging of this invention is very excellent in mold release performance, the bag for retort food packaging excellent in the film opening property can be provided.
[0054]
Since the layer in contact with the food of the laminate for retort food packaging of the present invention is non-adhesive, the retort food that allows the consumer to smoothly take out the contents when taking out the contents as described above from the bag. Packaging bags can be provided.
[0055]
As described above, by using the heat-sealable film of the present invention laminated on a base film, there is no problem even in storage and distribution in cold regions, and it has excellent skin resistance, openness, and food hygiene. It is possible to provide a retort food packaging bag which is very excellent and allows the consumer to easily take out the contents.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a laminate for packaging retort food according to the present invention.
FIG. 2 is a cross-sectional view showing an example of a laminate for packaging retort food according to another embodiment of the present invention.
FIG. 3 is a cross-sectional view showing an example of a laminated body for retort food packaging according to still another embodiment of the present invention.
FIG. 4 is a cross-sectional view showing an example of a laminated body for retort food packaging according to still another embodiment of the present invention.
[Explanation of symbols]
1 Base film
11 Print layer
2 Adhesive layer
3 Heat-sealable film
31 Laminate side layer
32 Layers in contact with food
33 Fine particles of fluororesin
4 Functional films
41 Biaxially stretched nylon film
42 Aluminum foil
10 Laminate for retort food packaging

Claims (3)

In a food packaging bag in which a laminate composed of a heat-sealable film and a base film made of a resin composition containing at least a propylene resin as a main component is formed into a bag shape so that the heat-sealable film is inside, The resin composition containing propylene resin as a main component is composed of at least two layers: a layer (A) on the laminate side and a layer (B) in contact with food, and the layer (B) in contact with food contains fluorine resin. look-containing fine powder, and a layer in contact with the food (B) is a fine powder of a fluorine-based resin, relative to 100 parts by weight of propylene resin, made of a resin in a proportion of 0.1 to 10 parts by weight A layered product for retort food packaging.   2. The laminate for retort food packaging according to claim 1, wherein the fluororesin comprises a tetrafluorinated resin and / or a compound having a trifluorinated carbon structure at least in either a side chain or a main chain terminal. body. The retort food packaging according to claim 1 or 2, wherein the heat-sealable film comprises a multilayer film formed by coextrusion of at least two layers of a laminate side layer (A) and a layer in contact with food (B). Laminated body.

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