JP6003228B2 - blank - Google Patents

Description

  The present invention relates to a liquid paper container for milk, juice, sake, wine and the like. In particular, the transfer of the adhesive used for the paper container to the contents of low molecular weight substances is suppressed. The present invention relates to a liquid paper container that suppresses the deterioration of taste and scent quality of contents.

  Conventionally, a liquid paper container comprising a laminate in which paper is a base material layer, an outer surface is a polyolefin resin layer having heat sealability and moisture resistance, an inner surface is sequentially laminated with a gas barrier layer, and a sealant layer is widely used. . In particular, a gas barrier layer is laminated so as not to impair the taste and aroma of the contents. As the shape of the paper container, a gable top shape having a gable roof shape at the top and a flat top shape having a flat shape are widely used.

  In order to laminate the gas barrier layer and the sealant layer on the inner surface of the paper container, a method of extruding and laminating the sealant layer via an anchor coating agent (adhesive), and a method of dry laminating a sealant film prepared in advance via an adhesive and so on.

  The extrusion laminating method and the dry laminating method through an adhesive are used for laminating paper, aluminum foil, plastic film and the like because of their excellent adhesive strength. It is also widely used for laminates that form liquid paper containers. In particular, the dry laminating method is widely used because of its good adhesive strength and production efficiency.

  However, the method using an adhesive has a problem of shifting to the contents of the low-molecular substance derived from the adhesive. For example, in the dry laminating method, the adhesive solution is laminated on the surface of the first base material (outer base material), and immediately after drying, the adhesive surface is uncured and somewhat tacky (tack). This is a method in which a base material (inner base material) is pressure-bonded and wound up, aged, and cured by curing an adhesive to be laminated. However, there are many cases where a low molecular weight substance remains in the adhesive, and there is a problem that the low molecular weight substance passes through the sealant layer and migrates to the contents. Moving to the contents leads to a decrease in taste and aroma quality.

  In order to solve these problems, there is a proposal that the anchor coat agent of the extrusion laminate is composed of a compound containing an isocyanate group and no alcohol group (Patent Document 1). The generation of fine particles due to urethane compounds and polymers thereof is eliminated by urethane bonds from alcohols such as polyols and isocyanates contained in the anchor coating agent, and migration to the contents is suppressed.

  However, the extrusion lamination using the anchor coating agent needs to reduce the thickness of the anchor coating agent. Even in this proposal, it is set to 1 μm or less. Some contents contain an alkaline substance, an acidic substance, a fragrance, a surfactant, and the like. Therefore, these substances have an adverse effect on the anchor coating agent, and there is a problem of a decrease in laminate strength.

  Proposal to have a polyolefin resin layer on a paper support and to laminate a sealant layer (polyester resin) through a modified layer formed on the surface of the polyolefin resin by a method that does not use an adhesive (patent) There is literature 2). That is, the present invention proposes that a polyolefin resin surface is subjected to low-temperature plasma treatment to provide a modified layer, and then a sealant layer is extruded and laminated on the modified layer.

However, this method requires expensive equipment such as a low-temperature plasma processing machine, and there is a problem that the production cost increases.

  There is also a proposal to suppress the migration to the content of low molecular weight substances derived from adhesives by cross-linking the inner surface of the sealant layer by electron beam irradiation after laminating by a method of dry laminating the base material layer and the sealant layer (patent) Reference 3).

  In this method, the electron beam irradiation dose is defined in the range of 10 kGy to 1000 kGy in an inert gas atmosphere. It is a proposal to increase the crosslink density of the sealant layer and suppress the migration of low molecular weight substances derived from adhesives to the contents, but the problem is that low molecular weight substances and decomposition components from the sealant layer itself will newly migrate to the contents There is.

  Therefore, there is a need for a liquid paper container that suppresses the transition to the contents of low-molecular-weight substances derived from an adhesive in a method of laminating the gas barrier layer and sealant layer on the inner surface of the paper container via an adhesive.

JP 2012-66868 A Japanese Patent Laid-Open No. 9-156043 JP 2000-127302 A

  The present invention has been made in view of such a situation, and is a liquid paper container that suppresses the transfer of a low-molecular substance derived from an adhesive for dry laminating to the contents, and the taste and scent quality of the contents It is an object of the present invention to provide a blank in which deterioration is suppressed and a liquid paper container using the same.

  In order to solve the above problems, the inventors have intensively studied and completed the present invention.

The invention according to claim 1 of the present invention comprises a laminate in which paper is used as a base material layer and a thermal adhesive resin layer / base material layer / adhesive resin layer / gas barrier layer / adhesive layer / sealant layer are sequentially laminated. In a blank where the layer is the inner surface and molded to form a liquid paper container,
A blank which has a top seal part, a top part, a body part, and a bottom part, and the body part forms a square cylindrical liquid paper container composed of four side plates via four vertical side ridge lines. There,
The blank is characterized in that the adhesive layer is not laminated in the region of the non-sealed portion of the four side plates.

  The invention according to claim 2 of the present invention is the blank according to claim 1, wherein an adhesive layer is laminated on a portion of the side ridge ruled line in the region of the non-seal portion.

  In the liquid paper container of the present invention, the transition to the content of the low-molecular substance derived from the adhesive is suppressed by not laminating the adhesive layer in the region of the non-sealed part of the four side plates forming the body part. Is. It is a paper container that suppresses the taste of the contents and the quality of the fragrance. Further, the liquid paper container maintains the shape retention and rigidity of the paper container by forming an adhesive layer on the side ridge ruled line in the non-sealed region.

  According to claim 1 of the present invention, the adhesive layer is not laminated in the region of the non-sealed portion of the four side plates, thereby suppressing the transfer of the low molecular weight substance derived from the adhesive to the contents. Is. Further, since the adhesive layer is not laminated in the region, the adsorption of the fragrance component of the contents to the adhesive layer is reduced, and a paper container in which the taste of the contents and the quality of the scent are suppressed can be obtained.

  According to claim 2 of the present invention, the paper container can be appropriately formed by laminating the adhesive at the site of the side ridge ruled line in the region of the non-seal portion. In addition, the shape retention and rigidity of the paper container can be maintained.

Gas gas barrier layer, a polyester film der lever with a deposit of an inorganic oxide, paper container has a recycling property can have excellent gas barrier properties of aluminum foil par.

No machine oxide, silicon oxide or aluminum oxide der lever, productivity, can have a gas barrier property having a value of.

It is explanatory drawing which shows an example of the blank (inner surface) of this invention. It is explanatory drawing which shows an example of the area | region which does not laminate | stack an adhesive layer with the blank (inner surface) of this invention. It is explanatory drawing which shows an example of the area | region which does not laminate | stack an adhesive layer with the blank (inner surface) of this invention. It is explanatory drawing which shows an example of the area | region which does not laminate | stack an adhesive layer with the blank (inner surface) of this invention. It is explanatory drawing which assembles the blank of FIG. 1 and shows an example of a gable top type paper container. It is explanatory drawing which assembles the blank of FIG. 2 and shows an example of a gable top type paper container. It is explanatory drawing which assembles the blank of FIG. 1 and shows an example of a flat top type paper container. It is explanatory drawing which assembles the blank of FIG. 2 and shows an example of a flat top type paper container. It is explanatory drawing which shows an example of the LL 'cross section of FIG. It is explanatory drawing which shows an example which made the blank of FIG. 1 the sleeve.

  Hereinafter, embodiments for carrying out the present invention will be described. A blank for forming a gable-top paper container will be described as an example.

FIG. 1 is an explanatory view showing an example of the blank (inner surface) of the present invention. In the blank 20, the back seal panel 21, the left panel 22, the front panel 23, the right panel 24, and the back panel 25 are sequentially connected to each other at the same interval via four vertical folding lines a. The top seal portion A, the top portion B, and the top and bottom portions of each connected panel are connected to each other via the respective horizontal broken lines b.
A body portion C and a bottom portion D are partitioned. Folding plates 26 are respectively provided above the left panel 22 and the right panel 24, and seal plates 30 are formed on the folding plates. Further, a roof plate 27 is formed on the top of the front panel 23 and the back panel 25, respectively, and a seal plate 30 is formed on the top of the roof plate. Further, bottom plates 28 that are molded to form a bottom portion D are formed at the lower portions of the back seal panel 21, the left panel 22, the front panel 23, the right panel 24, and the back panel 25, respectively. Further, a plug attachment hole 32 is formed at the top of the front panel. The four side plates 29 are connected to each other via four side ridge lines c.

  FIG. 2 is an explanatory view showing an example of a region where an adhesive layer is not laminated on the blank (inner surface) of the present invention. The area | region 37 where the contact bonding layer is not laminated | stacked is shown. Further, the edges of the back seal panel and the back panel are sealed to form a sleeve 45 as shown in FIG. 10 when forming a paper container. There is a seal portion 38 at the edge of the side plate of the back panel. Therefore, the area | region 37 where the contact bonding layer is not laminated | stacked is formed in the area | region of the four side plates except this seal | sticker part. Further, the adhesive layer 6 is laminated on the side ridge ruled line c of the region 37.

  FIG. 3 is an explanatory diagram showing an example of a region where the adhesive layer is not laminated on the blank (inner surface) of the present invention. A region 37 where the adhesive layer is not laminated on the side plate of the front panel 23 and the side plate of the right panel 24 is shown. Further, a state is shown in which the adhesive layer 6 is laminated on the side ridge ruled line c via the side plate of the front panel 23 and the side plate of the right panel 24.

  FIG. 4 is an explanatory view showing an example of a region where an adhesive layer is not formed on the blank (inner surface) of the present invention. A region 37 where no adhesive layer is laminated is formed on the side plate of the left panel 22 and the side plate of the right panel 24.

  FIG. 5 is an explanatory view showing an example of a gable top type paper container by assembling the blank of FIG. A cap 35 and a cap 36 are attached to the top B of the gable-top paper container 50. This is a general gable-top liquid paper container.

  FIG. 6 is an explanatory view showing an example of a gable-top type paper container by assembling the blank of FIG. The paper container which assembled the blank with which the contact bonding layer is not laminated | stacked on the area | region of the non-seal part of the four side plates is shown. FIG. 6 shows a region 37 where no adhesive layer is laminated on the side panel of the front panel and the side panel of the right panel. Further, an adhesive layer 6 is laminated on the side ridge ruled line c via the side panel of the front panel and the side panel of the right panel.

  FIG. 7 is an explanatory view showing an example of a flat-top type paper container by assembling the blank of FIG. The top B of the flat top paper container 60 shows a paper container with a cap 35 and a cap 36 attached thereto. This is a general flat top liquid paper container.

  FIG. 8 is an explanatory view showing an example of a flat-top type paper container by assembling the blank of FIG. The paper container which assembled the blank which has the area | region where the adhesive layer of the non-seal part of four side plates is laminated | stacked is shown. A region 37 where an adhesive layer is not laminated is shown on the side panel of the front panel and the side panel of the right panel. Further, an adhesive layer 6 is laminated on the side ridge ruled line c via the side panel of the front panel and the side panel of the right panel.

FIG. 9 is an explanatory diagram showing an example of the LL ′ cross section of FIG. 2. Laminate 1 is composed of a thermal adhesive resin layer 2 / base material layer 3 / adhesive resin layer 4 / gas barrier layer 5 / adhesive layer 6 / sealant layer 7 from the surface side. A region 37 where no adhesive layer is laminated is formed in the non-sealed portion of the four side plates 29 via the side ridge ruled line c. That is, the adhesive is not laminated on the side plate except for the seal portion 38 of the side plate of the back panel. In addition, an adhesive layer 6 is laminated at a portion of the side ridge ruled line c in the non-seal portion region.

  FIG. 10 is an explanatory view showing an example in which the blank of FIG. 1 is used as a sleeve. The sleeve shown in FIG. 1 is formed by sealing the edges of the back seal panel and the back panel while folding the blank. The sleeve is formed to produce a paper container.

  Hereinafter, embodiments for carrying out the present invention will be described in more detail.

As the base material layer 3 forming the laminate 1, a paperboard having a basis weight of 200 to 500 g / m ² and a density of 0.6 to 1.1 g / cm ³ can be used. Paperboard such as milk base paper and cardboard can be used. In particular, the basis weight of the paperboard is preferably 320 g / cm ² .

  As the resin for forming the thermal bonding resin layer 2, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or the like can be used. These resins are extruded and laminated on the base material layer. The thickness of the heat bonding resin layer is preferably in the range of 15 to 30 μm.

  As the adhesive resin layer 4, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ethylene-methacrylic acid copolymer (EMAA), ethylene -Polyolefin resins such as ethyl acrylate copolymer (EAA), ionomer, and polypropylene can be used. These resins can be used by forming a film with an extruder. The thickness is preferably in the range of 10 to 30 μm.

  As the gas barrier layer 5, a film such as a polyester film, a stretched polypropylene film, a stretched polypropylene film or the like on which an inorganic oxide is deposited can be used. The thickness of the film is preferably in the range of 6 to 25 μm.

  As the inorganic oxide, metal oxides such as diatom oxide, aluminum oxide, magnesium oxide, calcium, potassium, tin, sodium, boron, titanium, lead, zirconium, and yttrium can be used. Of these, silicon oxide and magnesium oxide are preferable in terms of productivity and price. The thickness of the deposited layer of the inorganic compound is preferably in the range of 5 to 300 nm, and more preferably in the range of 5 to 100 nm. The value may be selected as appropriate. Further, the direction of the vapor deposition surface may be either the base material layer side or the sealant layer side.

  Moreover, what laminated | stacked aluminum foil on films, such as a polyester film, a stretched polypropylene film, and a stretched polypropylene film, can also be used. The thickness of the film can be in the range of 6-25 μm, and the aluminum foil can be in the range of 5-15 μm. However, paper containers using aluminum foil have a problem of aluminum residue in recycling and a problem of aluminum residue in incineration. It is preferable to use a film on which an inorganic oxide is deposited.

  The sealant layer 7 can be a resin such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE), and may be a single layer or multiple layers. A linear low density polyethylene (LLDPE) resin is preferable. The sealant layer preferably has a thickness in the range of 30 to 100 μm.

The adhesive layer 6 can be bonded using an adhesive. Examples of the adhesive include a polyurethane adhesive and a two-component curable adhesive made of an organic polyol and a polyfunctional polyisocyanate. For liquid paper containers, two-component curable adhesives that have excellent adhesive strength and are difficult to reduce the adhesive strength due to the chemical components of the contents are mainly used. The two-component curable adhesive is composed of a main agent and a curing agent. For example, as the main agent, isophthalic acid, adipic acid, sebacic acid and the like, and an ester compound composed of ethylene glycol, neopentyl glycol, 1,6 hexanediol, Polyester / urethanediol resin composed of isophorone diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, etc., and those further containing a silane coupling agent or an epoxy resin. Although what consists of xylylene diisocyanate, hexamethylene diisocyanate, etc. are mentioned, it is not limited to these.

  The adhesive layer that bonds the gas barrier layer and the sealant layer can be dry-laminated via an adhesive. Further, the sealant layer can be extruded and laminated through an anchor coating agent (adhesive). It is preferable to use a dry laminating method because of excellent adhesive strength and production efficiency.

  Further, the adhesive is not laminated in the region of the non-sealed portion of the four side plates forming the body portion. For that purpose, it is necessary to laminate | stack an adhesive layer with a pattern. For example, in the dry laminating method, the roll plate on which the adhesive is laminated can be formed into a pattern plate. Create a pattern plate in which the adhesive is not laminated on the area of the non-seal part of the four side plates that form the body part, and the adhesive is laminated on the side ridge ruled part of the non-seal part area. What is necessary is just to use the roll plate at the time of dry lamination. The roll plate can be prepared by a corrosion method or an engraving method in the same manner as a gravure roll plate.

  Next, the blank of this invention and the manufacturing method of a liquid paper container using the same are demonstrated.

  On the outer surface of the base material layer, a low density polyethylene resin as a heat bonding resin layer is extruded and laminated using an extruder.

  Next, a polyester film on which an inorganic oxide serving as a gas barrier layer is vapor-deposited and a film made of a linear low-density polyethylene resin in a sealant layer are dry-laminated using an adhesive and bonded together. At this time, the pattern is formed so that the adhesive is not laminated on the area of the non-sealed part of the four side plates forming the body part, and the adhesive is laminated on the side ridge ruled part of the area of the non-sealed part. To create a laminated film. The direction of the vapor-deposited surface of the inorganic oxide may be either the base material layer side or the sealant layer side.

  Next, the laminated film is bonded to the inner surface of the base material layer via an adhesive resin layer. The adhesive resin layer is extruded from an extruder, and a laminate is formed through the adhesive resin layer. The laminate is composed of a thermal adhesive resin layer / base material layer / adhesive resin layer / gas barrier layer / adhesive layer (pattern) / sealant layer in order from the outer surface. This laminated board is usually made into a roll shape or a sheet shape.

  Folding line processing and punching processing are performed so that this laminated board is aligned with the area of the non-sealed part of the four side plates forming the body part, and the side ridge ruled part of the area of the non-sealed part. create. For example, a method using a Thomson punching die incorporating a metal blade or the like, or a method using a metal roll having a rotary blade is possible. At this time, a plug attachment hole is formed at the same time.

  The blank is folded along a longitudinal fold line, assembled, and the back seal panel and the back panel are overlapped and sealed to form a sleeve as shown in FIG.

Insert the created sleeve into a filling machine that fills the contents, molds and closes the bottom, attaches the stopper to the stopper mounting hole, fills the contents, seals the top seal, and liquids Create a container. For example, if the top part is formed into a gable roof shape while folding the folding plate 26 shown in FIG.

  A pattern and characters can be printed on the surface of the heat bonding resin layer 2. As the printing method, a normal printing method such as a gravure printing method, an offset printing method, an ink jet printing method, a flexographic printing method can be used. Moreover, if the surface of the heat-adhesive resin layer is corona-treated, the adhesion with the printing ink can be improved.

  Hereinafter, specific examples of the present invention will be described.

A polyethylene film having a thickness of 20 μm was laminated on the outer surface of a milk base paper having a basis weight of 320 g / m ² by an extruder of a low density polyethylene resin.

  As a gas barrier layer, a polyester film 12μ deposited with silicon oxide was used. The thickness of the deposited layer of silicon oxide is 30 nm.

  As a sealant layer, a linear low density polyethylene resin was formed in advance with an extruder to prepare a linear low density polyethylene film of 60 μm.

  Next, the polyester film surface of the gas barrier layer and the linear low-density polyethylene film of the sealant layer were bonded together by a dry lamination method using a polyurethane two-component curable adhesive to prepare a laminated film. At this time, as shown in FIG. 2, the roll plate for laminating the adhesive is blanked up so that the adhesive is not laminated on the non-sealed portions of the four side plates forming the body portion. It patterned so that an adhesive might be laminated | stacked on the site | part of the side ridge ruled line of the area | region of a seal | sticker part, and laminated | stacked and bonded the adhesive agent. The roll plate was prepared by engraving as in the case of creating a gravure roll plate.

  Next, the laminated film was laminated on the inner surface of the milk base paper via an ethylene-methacrylic acid copolymer (EMAA) resin. Under the present circumstances, ethylene-methacrylic acid copolymer (EMAA) resin was extruded with the extruder, and thickness was 30 micrometers. A laminated plate was prepared by using the silicon oxide vapor deposition surface of the laminated film as a laminated surface.

  A blank for forming a gable top-shaped paper container having an internal capacity of 2 L and an 85 corner (interval of folding lines in the vertical direction) was prepared from the prepared laminate. Using a Thomson die, the fold line, the hole for plug attachment, and the outer shape were processed.

  As shown in FIG. 3, the adhesive is not laminated on the side panel of the front panel and the side panel of the right panel, and is adhered to the side ridge ruled part through the side panel of the front panel and the side panel of the right panel. A blank was prepared in the same manner as in Example 1 except that the agent was laminated.

  An aluminum foil of 6.5 μm and a polyester film of 12 μm were bonded together by a dry laminating method using a polyurethane two-component curable adhesive to form a gas barrier layer. At this time, as shown in FIG. 2, the roll plate for laminating the adhesive is blanked and the adhesive is not laminated on the non-sealed portions of the four side plates forming the body portion. A blank was prepared in the same manner as in Example 1 except that a patterned roll plate was used so that the adhesive was laminated on the side ridge ruled part of the region, and the adhesive was laminated.

<Comparative Example 1>
A blank was formed in the same manner as in Example 1 except that the polyester film surface of the gas barrier layer and the sealant layer were bonded together on the entire surface.

<Comparative example 2>
As a gas barrier layer, an aluminum foil 7 μm and a polyester film 12 μm are laminated and bonded together on the entire surface, and the gas barrier layer and the sealant layer are bonded together by laminating the adhesive on the entire surface. A blank was prepared in the same manner as in Example 3.

  The blanks prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were sealed with the back seal panel and the back panel, respectively, to form sleeves as shown in FIG. Next, this sleeve is placed on a filling machine, molded at the bottom, fitted with a stopper, sterilized and dried with hydrogen peroxide, filled with potato shochu as a content, top sealed, An 85 square gable top liquid paper container was prepared.

<Evaluation method>
The filled liquid paper containers prepared from the blanks of Examples 1 to 3 and Comparative Examples 1 and 2 were stored for 30 days in an environment of 40 ° C. and 65% RH, and then taste and fragrance were evaluated. Further, the remaining amount of the fragrance component was also measured.
・ Taste and fragrance are evaluated by sensuality. Unsaved contents were used as a reference. It was conducted by 20 sensory evaluators. ○ when all members had no change, and × when one member had changed.
-As for the residual amount of the fragrance component, the residual amount of the fragrance component (fatty acid ethyl) was analyzed by GCMS by a solid layer microextraction method (SPME method). The target fatty acid ethyl was ethyl caproate. The value of unstored contents was set to 1.

<Evaluation results>
Table 1 shows.

In Examples 1-3, there was no change in both taste and aroma. In Comparative Examples 1 and 2, both taste and aroma were changed. Moreover, in the aroma component residual amount, the ethyl caproate residual rate showed 0.7-0.8 in Examples 1-3. It was found that the larger the area where the adhesive was not laminated, the greater the residual ratio of ethyl caproate. In Comparative Examples 1-2, 0.4-0.5 was shown. By forming the area where the adhesive is not laminated, the migration of the low-molecular substance derived from the adhesive to the contents is suppressed and the adsorption of the aroma component to the adhesive is also suppressed. There was no change in both. Moreover, there was no problem in the process of forming the liquid paper container by molding the blanks of Examples 1 to 3. Also, no deformation of the liquid paper container was observed after storage.

  The liquid paper container of the present invention can be used for beverages such as juices, soups, dairy drinks (soy milk, coffee milk, etc.), dairy products (whipped cream, etc.), alcoholic beverages (sake, shochu, plum wine, etc.) and coffee. It can also be used for food solids other than liquids. It can also be used as a non-food product in perm liquids, detergents, softeners, building material waxes, and the like.

DESCRIPTION OF SYMBOLS 1 Laminated body 2 Thermal adhesive resin layer 3 Base material layer 4 Adhesive resin layer 5 Gas barrier layer 6 Adhesive layer 7 Sealant layer 10 Blank 21 Back seal panel 22 Left panel 23 Front panel 24 Right panel 25 Back panel 26 Folding board 27 Roof board 28 Bottom plate 29 Side plate 30 Seal plate 32 Plug attachment hole 35 Plug 36 Cap 37 Area where adhesive layer is not laminated 38 Seal portion A Top seal portion B Top portion C Body portion D Bottom portion a Vertical bending line b Horizontal direction Bending line c Side ridge ruled line 50 Liquid paper container of the present invention (gable top type)
60 Liquid paper container of the present invention (flat top type)

Claims (2)

It is composed of a laminated plate in which paper is used as a base material layer, and a thermal adhesive resin layer / base material layer / adhesive resin layer / gas barrier layer / adhesive layer / sealant layer are sequentially laminated. In the blank to form
A blank which has a top seal part, a top part, a body part, and a bottom part, and the body part forms a square cylindrical liquid paper container composed of four side plates via four vertical side ridge lines. There,
The blank, wherein the adhesive layer is not laminated in a region of the non-seal portion of the four side plates.   The blank according to claim 1, wherein an adhesive layer is laminated on a portion of the side ridge ruled line in the region of the non-seal portion.