JP2006248594A - Paper cup with barrier characteristic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide paper cup with a barrier characteristic which is superior in recycling characteristic, whose gas barrier characteristic is not lowered in forming process, and which maintains the superior gas barrier characteristic. <P>SOLUTION: This paper cup with a barrier characteristic is made of a laminated material having a gas barrier characteristic. The method for forming the laminated material comprises: a step of laminating an inorganic oxide vapor deposition thin film layer on one face of a base material film layer or laminating the vapor deposition thin film layer and a coated film having a gas barrier characteristic on one face of the base material; a step of laminating an adhesive agent A layer and a paper layer on the one face where the vapor deposition thin film is laminated or on the one face where the coated film having a gas barrier characteristic is laminated; and a step of laminating an adhesive agent B layer and a sealant layer on the other face. The cup is so formed that the sealant layer contacts a content. The adhesive agent A layer is made of a polyurethane coated film whose tensile fracture elongation is 300% or more when the test piece of the agent A layer whose width is 0.5 cm and length is 2 cm is pulled at a pulling speed of 6cm/min under a relative humidity of 65%. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a paper cup having excellent gas barrier properties for packaging various foods and non-foods.

Conventionally, as a paper container having an excellent gas barrier property, a laminated material in which a thermoplastic resin layer, an adhesive layer, a paper base layer, an adhesive layer, a gas barrier layer, an adhesive layer, and a sealant layer are laminated in order from the outside. Many of the molded products are used, and as the gas barrier layer in the above configuration, aluminum foil is often used, but there are problems such as poor recyclability. In order to improve these problems, as a gas barrier layer that has functions such as gas barrier properties and recyclability, as the gas barrier layer, a gas barrier layer in which a vapor-deposited thin film layer of inorganic oxide and a gas barrier coating layer are laminated on one side of a biaxially stretched polyester film A paper cup using a laminated material using a film has been proposed (for example, see Patent Document 1).
JP 2003-127718 A

  However, the paper cup using the proposed laminated material has problems such that the vapor deposition thin film layer is easily cracked during the molding process and the gas barrier property is lowered.

  An object of the present invention is to provide a barrier paper cup that has excellent recyclability, does not deteriorate gas barrier properties during molding, and retains excellent gas barrier properties.

  In the invention according to claim 1 of the present invention, an adhesive A layer and a paper layer are laminated on one vapor-deposited thin film layer surface of a barrier laminate film in which an inorganic oxide vapor-deposited thin film layer is laminated on one side of a base film layer. Then, at least using the blank for the body part formed by punching out the gas barrier laminate material formed by laminating the adhesive B layer and the sealant layer on the other surface and the bottom blank formed by punching out into a circular shape, It is a barrier paper cup formed so that the sealant layer is in contact with the contents, and the adhesive A layer is a test piece having a width of 0.5 cm and a length of 2 cm under the conditions of a temperature of 20 ° C. and a relative humidity of 65%. A barrier paper cup comprising a polyurethane-based film having a tensile breaking elongation of 300% or more when measured by a method of pulling at a pulling speed of 6 cm / min.

  In the invention according to claim 2 of the present invention, the adhesive A is applied to one side of the gas barrier coating layer of the barrier laminated film in which the vapor-deposited thin film layer of inorganic oxide and the gas barrier coating layer are laminated on one side of the base film layer. Layer and paper layer and at least the adhesive B layer and sealant layer on the other side of the gas barrier laminate material punched into a fan-shaped body blank and the bottom punched out into a circular shape A barrier paper cup formed by using a blank so that the sealant layer is in contact with the contents, and the adhesive A layer is a test piece having a width of 0.5 cm and a length of 2 cm. A barrier paper cup comprising a polyurethane-based film having a tensile breaking elongation of 300% or more when measured by a method of pulling at a tensile speed of 6 cm / min under a condition of 65%.

The invention according to claim 3 of the present invention is the invention according to claim 2, wherein the gas barrier coating layer comprises a water-soluble polymer, (a) one or more metal alkoxides and hydrolysates thereof, or (b) tin chloride. It is a barrier paper cup characterized by comprising at least one of the above.

  The invention according to claim 4 of the present invention is characterized in that, in the invention according to any one of claims 1 to 3, the inorganic oxide is silicon oxide, aluminum oxide, or a mixture thereof. It is a barrier paper cup.

  The barrier paper cup of the present invention has an adhesive A layer on one vapor deposition thin film layer surface of a barrier laminate film in which a vapor deposition thin film layer made of silicon oxide, aluminum oxide or a mixture thereof is laminated on one surface of the base film layer, A vapor-deposited thin film layer made of silicon oxide, aluminum oxide or a mixture thereof on one side of a gas barrier laminate material or a base film layer obtained by laminating a paper layer and laminating at least an adhesive B layer and a sealant layer on the other side One gas barrier coating layer surface of a barrier laminate film in which polyvinyl alcohol and (a) one or more metal alkoxides and hydrolysates thereof or (b) a gas barrier coating layer comprising tin chloride are laminated. A gas barrier property in which an adhesive A layer and a paper layer are laminated to each other and at least an adhesive B layer and a sealant layer are laminated on the other surface. A barrier paper cup formed using a body blank punched out in a fan shape and a bottom blank punched out in a circular shape so that the sealant layer is in contact with the contents, the adhesive Polyurethane having a tensile elongation at break of 300% or more when the agent A layer is measured by a method of pulling a test piece having a width of 0.5 cm and a length of 2 cm at a temperature of 20 ° C. and a relative humidity of 65% at a tensile speed of 6 cm / min. Since it is made of a coating, the flexible polyurethane coating or the gas barrier coating layer of the adhesive A layer serves to prevent cracking of the deposited thin film during the molding process, and the deposited thin film layer serves as the base film layer. Since it is laminated between the paper layers, it is hardly affected by heat from the inner surface during the molding process, and an excellent gas barrier property can be maintained because there is no distortion of the deposited thin film. In addition, if a gas barrier laminate material in which an adhesive resin layer made of polyolefin resin is further laminated between the paper layer and the adhesive A layer is used, the cushioning property at the time of molding process is improved, and the deposited thin film at the time of molding process is improved. Cracks hardly occur and excellent gas barrier properties can be obtained.

  The barrier paper cup of the present invention will be described in detail below along the embodiments.

  Fig.4 (a) is a sectional side view which shows one Embodiment of the gas-barrier laminated material used for the trunk | blank blank and bottom blank of the barrier paper cup of this invention, and a gas-barrier laminated material (30) is an outer side. In order from the thickness direction to the paper layer (23), the adhesive A layer (22), the barrier laminated film (20) comprising the vapor-deposited thin film layer (12) of the inorganic oxide and the base film layer (11), the adhesive It is the structure which laminated | stacked B layer (24) and sealant layer (25), (b) is a sectional side view which shows other embodiment of gas-barrier laminated material, and gas-barrier laminated material (31) is from an outer side. Barrier laminate comprising a paper layer (23), an adhesive A layer (22), a gas barrier coating layer (13), an inorganic oxide vapor-deposited thin film layer (12), and a base film layer (11) in the thickness direction. Film (21), adhesive B layer (2 ), A structure in which the sealant layer (25) laminated.

  A gas barrier laminate material having a structure in which an adhesive resin layer made of a polyolefin resin having a thickness of 10 to 30 μm is further laminated between the paper layer (23) and the adhesive A layer (22).

  The base film layer (11) may be a biaxially stretched polyester film, a biaxially stretched nylon film, a biaxially stretched polypropylene film, or the like, but is preferably a biaxially stretched polyester film.

Since the inorganic oxide of the vapor-deposited thin film layer (12) is made of aluminum oxide, silicon oxide or a mixture thereof, it has excellent gas barrier properties. The lamination method can be formed by a normal vacuum vapor deposition method, and the heating means of the vacuum vapor deposition apparatus by the vacuum vapor deposition method is preferably an electron beam heating method, a resistance heating method, an induction heating method, or the like. In order to improve the adhesion with 11), it is also possible to use a plasma assist method or an ion beam assist method.

  The film thickness of the vapor-deposited thin film layer (12) is preferably in the range of 5 to 300 nm, and the value is appropriately selected. However, if the film thickness is less than 5 nm, a uniform thin film may not be formed on the entire surface of the base film layer (11), and the gas barrier function may not be sufficiently achieved. On the other hand, when the film thickness exceeds 300 nm, the deposited thin film cannot be kept flexible, and the deposited thin film may be cracked due to external factors such as bending and pulling after the deposition.

  The gas barrier coating layer (13) is laminated in order to provide high gas barrier properties and to protect the vapor-deposited thin film layer (12) of inorganic oxide, and its constituent components are a water-soluble polymer, ( It is formed by applying a coating agent mainly composed of an aqueous solution or water / alcohol mixed solution containing at least one of a) one or more metal alkoxides and hydrolysates or (b) tin chloride. Evaporation thin film layer: A solution in which water-soluble polymer and tin chloride are dissolved in an aqueous (water or water / alcohol mixed) solvent, or a solution in which metal alkoxide is directly or previously hydrolyzed is mixed. (12) It is formed by coating and heating and drying.

  Examples of the water-soluble polymer used in the gas barrier coating layer (13) include polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, and sodium alginate. In particular, when polyvinyl alcohol (hereinafter referred to as PVA) is used, the gas barrier property is most excellent. PVA as used herein is generally obtained by saponifying polyvinyl acetate, from a so-called partially saponified PVA in which several tens percent of acetic acid groups remain to completely saponified PVA in which only several percent of acetic acid groups remain. Including, but not limited to.

The tin chloride may be stannous chloride (SnCl ₂ ), stannic chloride (SnCl ₄ ), or a mixture thereof, and may be an anhydride or a hydrate. Furthermore, the metal alkoxide is preferably tetraethoxysilane, triisopropoxyaluminum or a mixture thereof, and the use of these improves water resistance and the like.

  As the method for laminating the gas barrier coating layer (13), known means such as a commonly used dipping method, roll coating method, screen printing method, spray method and the like can be used. The film thickness after drying may be 0.1 μm or more, but if the thickness exceeds 50 μm, cracks are likely to occur in the film, so the range of 0.1 to 50 μm is preferable.

The paper layer (23) is made from paperboard having a basis weight 80~300g / m ^2.

  The adhesive A layer (22) has a tensile elongation at break when measured by a method in which a test piece having a width of 0.5 cm and a length of 2 cm is pulled at a tensile rate of 6 cm / min under conditions of a temperature of 20 ° C. and a relative humidity of 65%. Is made of a polyurethane-based film having 300% or more. Therefore, the flexible film plays a role of preventing the thin film of the deposited thin film layer (12) from cracking. The thickness is preferably in the range of 2 to 10 μm.

The adhesive B layer (24) is made of a commonly used polyurethane adhesive, and the coating amount is preferably 1 to 5 g / m ² (dry state).

The sealant layer (25) is not particularly limited as long as it is a resin having a sealing property and a low odor, but a low density polyethylene resin, a linear low density polyethylene resin, or the like is preferable from the viewpoint of a low temperature sealing property. The thickness is preferably in the range of 10 μm to 30 μm.

  Fig.3 (a) is a top view which shows one Embodiment of the trunk | blank blank used for the barrier paper cup of this invention, and the trunk | blank blank (40) makes the said gas-barrier laminated material (30) into a fan shape. It is made of a punch and has linear ends (40a) and (40b) on both sides, and (b) shows one embodiment of the bottom blank used in the barrier paper cup of the present invention. It is a top view, The blank for bottom part (41) consists of what punched the said gas-barrier laminated material (30) in circular shape.

  FIG. 1 is a perspective view showing an embodiment of a barrier paper cup according to the present invention. A barrier paper cup (1) includes a body blank (40) obtained by punching a gas barrier laminate material (30) into a circular shape and a circle. It is formed using a bottom blank (41) punched into a shape, and has a bottom seal portion (2), a side seal portion (3), and an opening portion (4).

  FIG. 2 (a) is an explanatory view showing the shape of the side seal portion of FIG. 1, and the side seal portion (3) is a cylinder having a trunk blank (40) with the sealant layer (25) as an inner surface. The one linear end (40a) and the other linear end (40b) are overlapped with a predetermined width, and the resin of the sealant layer (25) on the end (40a) side is melted by heat. It is adhered to the paper layer (23) on the edge (40b) side.

  FIG. 2 (b) is an explanatory view showing the shape of the bottom seal portion of FIG. 1, and the bottom seal portion (2) is for the bottom at the lower end on the small opening side of the cylindrical blank (40). The molded blank (41) is heat-sealed so that the sealant layers face each other.

  In the barrier paper cup of the present invention, the adhesive layer A of the gas barrier laminate material used for the body blank and the bottom blank is made of a very flexible polyurethane-based coating, and is directly above the deposited thin film layer or Since it is laminated on the gas barrier coating layer, it plays the role of preventing cracking of the fragile vapor-deposited thin film during molding, and the vapor-deposited thin film layer is laminated between the base film layer and the paper layer. It is hardly affected by heat from the inner surface during processing, and there is no distortion of the deposited thin film, and as a result, excellent gas barrier properties are maintained.

  The barrier paper cup of the present invention will be described below with specific examples.

As a barrier laminated film (21), a vapor-deposited thin film layer of 50 nm thick silicon oxide is laminated on one side of a 12 μm thick biaxially stretched polyethylene terephthalate (PET) film, and then 10.4 g of tetraethoxysilane is laminated thereon. Add 89.6 g of 0.1N hydrochloric acid, stir for 30 minutes to hydrolyze the hydrolyzed solution with a solid content of 3 wt% (in terms of SiO ₂ ), and a 3 wt% water / isopropyl alcohol solution of polyvinyl alcohol (water / isopropyl alcohol is Using a barrier laminate film in which a gas barrier coating layer having a thickness of 0.5 μm is laminated using a coating solution in which 90/10 by weight percent is blended to 60/40 by weight percent, a paper layer (23 ) using paperboard having a basis weight of 260 g / m ² as, (as an adhesive 22), polyurethane adhesive (Dai-Nippon ink Co. adhesive a layer, trade name LX901), a polyurethane-based adhesive (Mitsui Takeda Chemical Co., Ltd., trade name: A610) is used as the adhesive for the adhesive B layer (24), and the density of the resin is 0.2 for the sealant layer (25). Using a polyethylene (PE) resin of 915 g / cm ³ , paperboard (basis weight 260 g / m ² ) / adhesive A layer (10 μm) / gas barrier coating layer (0.5 μm) / silicon oxide deposited thin film layer (50 nm ) / PET film (12 μm) / adhesive B layer (coating amount 5 g / m ² ) / PE (50 μm) gas barrier laminate material (31) is prepared, and the gas barrier laminate material (31) is used to determine The body blank and the bottom blank of the shape are punched out, and the body blank and the bottom blank are used to form the 16 ounce invention of the present invention having a structure as shown in FIGS. barrier You create a paper cup.

  Examples for comparison of the present invention will be described below.

Paperboard (basis weight 260 g / m ² ) / adhesive A layer (10 μm) / PET film (12 μm) / silicon oxide thin film deposited thin film layer (50 nm) / gas barrier coating layer (0.5 μm) / adhesive B layer (5 g A comparative barrier paper cup was prepared in the same manner as in Example 1 except that a gas barrier laminate material having a / m ² ) / PE (50 μm) configuration was used.

<Evaluation>
The oxygen barrier property and water vapor barrier property of the barrier paper cup of the present invention of Example 1 and the comparative barrier paper cup of Example 2 were evaluated by the following evaluation methods. The results are shown in Table 1.
(1) Evaluation Method of Oxygen Barrier Properties Oxygen of a specimen in which the opening of each prototype 16 ounce barrier paper cup was sealed with an aluminum foil, 9 μm / biaxially stretched polyester film, 12 μm / low density polyethylene, and a cover material having a structure of 20 μm. The permeability was measured using Modern Control (MOCONOXTRAN, 10 / 50A) at 25 ° C. in a 100% RH atmosphere to evaluate oxygen barrier properties.
(2) Evaluation Method of Water Vapor Barrier Properties 80 g of calcium chloride was put in each prototype 16 ounce barrier paper cup and sealed with a lid of aluminum foil, 9 μm / biaxially stretched polyester film, 12 μm / low density polyethylene, 20 μm. Prepare 5 specimens each sealed with aluminum foil, 9μm / biaxially stretched polyester film, 12μm / low density polyethylene, and 20μm lid material without putting calcium chloride and specimen, and those specimens are 40 ° C, 90% The samples were stored for 30 days under RH conditions, and the weights of each specimen before and after storage were measured and compared. The amount of water absorbed by calcium chloride was calculated and obtained, and the average value was calculated to evaluate the water vapor barrier property.

表１に示すように、実施例１の本発明のバリア性紙カップは、酸素透過度及び水分吸収量が小さく、酸素及び水蒸気のバリア性が良好であった。一方、実施例２の比較用のバリア性紙カップは、酸素透過度及び水分吸収量が大きく、酸素及び水蒸気のバリア性が共に劣っていた。

As shown in Table 1, the barrier paper cup of the present invention of Example 1 had low oxygen permeability and moisture absorption, and good barrier properties for oxygen and water vapor. On the other hand, the comparative barrier paper cup of Example 2 had large oxygen permeability and water absorption, and both oxygen and water vapor barrier properties were inferior.

It is a perspective view which shows one Embodiment of the barrier paper cup of this invention. (A) is explanatory drawing which shows the shape of the side seal part of the barrier paper cup of FIG. 1, (b) is explanatory drawing which shows the shape of the bottom seal part of the barrier paper cup of FIG. (A) is a top view which shows one Embodiment of the trunk | blank blank used for the barrier paper cup of this invention, (b) shows one Embodiment of the bottom blank used for the barrier paper cup of this invention. It is a top view. (A) is side sectional drawing which shows one Embodiment of the gas-barrier laminated material used for the trunk | blank blank and bottom blank of the barrier paper cup of this invention, (b) is other implementation of gas-barrier laminated material It is a sectional side view which shows a form.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Barrier paper cup 2 ... Bottom seal part 3 ... Side seal part 4 ... Opening part 11 ... Base film layer 12 ... Deposition thin film layer 13 ... Gas barrier film layer 20, 21 ... Barrier laminated film 22 ... Adhesive A layer 23 ... Paper layer 24 ... Adhesive B layer 25 ... Sealant layer 30, 31 ... Gas barrier laminate 40 ... Body blank 40a, 40b ... End 41 ... Bottom blank

Claims (4)

  An adhesive A layer and a paper layer are laminated on one vapor-deposited thin film layer surface of a barrier laminate film in which an inorganic oxide vapor-deposited thin film layer is laminated on one surface of a base film layer, and at least an adhesive B is formed on the other surface. A gas barrier laminate material formed by laminating a layer and a sealant layer is molded so that the sealant layer is in contact with the contents using a body blank and a bottom blank obtained by punching in a circular shape. A test piece having a width of 0.5 cm and a length of 2 cm was measured by pulling a test piece having a width of 0.5 cm and a length of 2 cm at a temperature of 20 ° C. and a relative humidity of 65% at a tensile speed of 6 cm / min. A barrier paper cup comprising a polyurethane-based film having a tensile elongation at break of 300% or more.   An adhesive A layer and a paper layer are laminated on one side of the gas barrier coating layer of the barrier laminated film formed by laminating an inorganic oxide vapor-deposited thin film layer and a gas barrier coating layer on one side of the base film layer, and the other side. At least, the sealant layer is formed by using a body blank obtained by punching a gas barrier laminate material obtained by laminating an adhesive B layer and a sealant layer into a fan shape and a blank for a bottom portion obtained by punching a circular shape. A test piece having an adhesive A layer width of 0.5 cm and a length of 2 cm under the conditions of a temperature of 20 ° C. and a relative humidity of 65%, and a tensile speed of 6 cm / min. A barrier paper cup comprising a polyurethane-based film having a tensile elongation at breakage of 300% or more as measured by a method of pulling with a wire.   3. The barrier property according to claim 2, wherein the gas barrier coating layer comprises a water-soluble polymer and at least one of (a) one or more metal alkoxides and hydrolysates thereof or (b) tin chloride. Paper cup.   The barrier paper cup according to any one of claims 1 to 3, wherein the inorganic oxide is silicon oxide, aluminum oxide, or a mixture thereof.

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