JP2012210753A - Lid material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lid material excellent in microwave oven suitability and disposal suitability, not detected by a metal detector, and excellent in dead hold property.
A lid material comprising a laminate having a bonding paper layer, a first adhesive layer, a resin film layer, a second adhesive layer, and a sealant layer in this order, the bonding paper layer comprising: A lid material comprising two or more paper layers and a wax layer positioned between the paper layers and laminating them, wherein the laminate does not have a layer made of aluminum. I will provide a.
[Selection] Figure 1

Description

  The present invention relates to a lid material used for a cup-shaped packaging container, in particular, a laminate comprising paper as a base material and not including a layer made of aluminum as a constituent element, dead hold property, suitability for microwave oven and The present invention relates to a lid that is excellent in discardability and is not detected by a metal detector, and a package using the lid.

  When using a packaging body such as instant noodles, the lid material is partially opened, hot water is poured into the packaging body for hot water reconstitution, the lid material is returned and resealed. Accordingly, the lid used for the package has a curved shape so as not to block the opening at the time of opening, in addition to functions such as content protection required for a normal lid, and then reseals it. Sometimes plastic deformation and shape retention, that is, dead hold, are required to return to the smooth shape before opening and hold it.

  Conventionally, a laminated body including a layer made of a metal such as aluminum has been used as a lid material that satisfies these requirements (Patent Document 1).

  However, since a lid material including a layer made of a metal such as aluminum is detected by a metal detector, a metal detector for detecting a metal foreign object mixed in is applied to a package using the lid material. There was a problem that I could not. In addition, when a package using a lid containing a metal foil is cooked in a microwave oven, there is a problem that sparks can occur at the outer periphery of the metal foil. Further, the lid material is inferior in discardability, and when the used lid material is incinerated, there is a problem that a metal such as aluminum adheres to the incinerator and shortens the life of the incinerator.

JP 2001-287317 A

  The present invention solves the above-mentioned problems and does not have a layer made of a metal such as aluminum in the layer structure, so that it is excellent in suitability for a microwave oven, that is, applicable to cooking in a microwave oven, and suitable for disposal. An object of the present invention is to provide a lid material that is excellent, that is, does not emit metal waste during incineration, is not detected by a metal detector, and has an excellent dead hold property, and a package using the lid material. .

  As a result of various studies, the present inventors have at least a lid made of a laminate having a bonding paper layer, a first adhesive layer, a resin film layer, a second adhesive layer, and a sealant layer in this order. The laminating paper layer is a layer having two or more paper layers and a wax layer located between the paper layers and laminating them, and the laminate includes a layer made of aluminum. It has been found that the above-described lid material and a package using the lid material, which are not provided, achieve the above-described object.

The present invention is characterized by the following points.
1. At least a cover material composed of a laminate having a bonding paper layer, a first adhesive layer, a resin film layer, a second adhesive layer, and a sealant layer in this order, the bonding paper layer being 2 Or a layer having a paper layer of more than that, and a wax layer positioned between the paper layers and laminating them, and the laminate does not have a layer made of aluminum. .
2. 2. The lid material according to 1 above, wherein the wax layer comprises a wax composition containing a wax selected from the group consisting of mineral wax, petroleum wax, synthetic hydrocarbon wax, and derivatives thereof.
3. 3. The lid material according to 2 above, wherein the wax composition further contains an ethylene vinyl acetate copolymer.
4). The bonding paper is a bonding paper composed of two paper layers and a wax layer that is positioned between them and bonds them, and the wax layer has a coating amount of the wax composition of 5 to 5. The lid material according to any one of the above 1 to 3, wherein the lid material is formed so as to be 100 g / m ² .

  When the lid of the present invention is partially opened and bent, for example, when pouring hot water into a container, the curved open can be maintained, and the lid can be returned to its original smooth state. When it is resealed, the smooth resealed state can be maintained, that is, excellent dead hold property is exhibited.

  In addition, the laminate constituting the lid material of the present invention does not have a metal foil such as an aluminum foil in the layer structure, so that it is excellent in suitability for microwave ovens and disposal, and can be applied for contamination inspection by a metal detector. It is.

It is a schematic sectional drawing which shows the example about the layer structure of the laminated body which comprises the cover material of this invention.

The present invention will be described in detail below.
<1> Layer Configuration of Laminate Constructing Cover Material of the Present Invention FIG. 1 is a schematic cross-sectional view showing an example of a layer configuration of a laminate used in the present invention.
In this invention, as shown in FIG. 1, this laminated body is a bonding paper layer (1), a 1st adhesive layer (2), a resin film layer (3), and a 2nd adhesive layer (4). The five layers of the sealant layer (5) have a basic layer structure, and the bonding paper layer (1) is positioned between and between the first and second paper layers (a1, a2). And a wax layer (b) to be joined.

  In another aspect of the laminate constituting the lid material of the present invention, the bonding paper constituting the bonding paper layer (1) is located between three or more sheets of paper and these sheets. It may consist of wax to be bonded.

Moreover, as needed, you may provide a printing layer in the surface of the side which is not adjacent to the 1st adhesive bond layer of a bonding paper layer, and may provide arbitrary surface protection layers, such as a polypropylene film.
Further, between the first adhesive layer (2) and the resin film layer (3) or between the resin film layer (3) and the second adhesive layer (4), a layer bearing a light shielding property, or a polyethylene resin A cushion layer that reinforces the close contact between the lid and the container may be provided.

  Hereinafter, the resin names used in the present invention are those commonly used in the industry.

<2> Laminating paper layer The laminating paper layer constituting the lid material of the present invention is a layer having two or more paper layers and a wax layer that is positioned between the paper layers and bonds them. .

The paper constituting the paper layer serves as a base material impregnated with the wax composition and gives rigidity to the lid. Arbitrary paper can be used depending on the desired rigidity and the impregnation property of the wax to be used, for example, high-quality paper, imitation paper, art paper, coated paper, pure white roll paper, special kraft paper, bleached kraft paper In addition to the above, label paper having improved water resistance, cup base paper, and the like can be used. The thickness of a paper layer is the range of 50-200 g / m < ² > by a rice basis weight as a sum total of the paper layer in a bonding paper, More preferably, it is 70-100 g / m < ² >. If the rice basis weight is less than 50 g / m ² , the thickness is too thin and the lid material is insufficiently rigid. In addition, when the rice basis weight exceeds 200 g / m ² , the lid member has too high rigidity, which may hinder the preferable curved curl shape of the lid member when opened.

  The wax layer is a layer made of a wax composition containing wax as a main component, and the wax composition contains a wax and, optionally, an ethylene vinyl acetate copolymer (EVA). By adding EVA to the wax, the creep resistance of the lid material of the present invention can be improved.

  As the wax, any wax that is solid at room temperature (23 ° C.) and becomes a low-viscosity liquid upon heating can be used. For example, plant waxes such as carnauba wax, animal waxes such as beeswax, and montan Synthetic resins with good compatibility such as mineral waxes such as wax, petroleum waxes such as paraffin wax and microcrystalline wax, synthetic waxes such as synthetic hydrocarbon wax, and various modified waxes, such as oxide wax and polyethylene. And blended wax. Particular preference is given to using waxes selected from the group consisting of mineral waxes, petroleum waxes, synthetic hydrocarbon waxes and their derivatives. Wax layers made of these waxes exhibit viscoelasticity suitable for the development of dead hold properties.

As EVA, any commercially available product can be used depending on the amount added to the wax composition and the wax used.
When the wax composition contains EVA, the content of EVA is 0 to 40% by mass of the whole composition, and in order to obtain good creep resistance, it is preferably 20 to 40% by mass. When the content of EVA is more than 40% by mass, it is not preferable because the adhesive force and the initial adhesive force necessary for pasting paper are reduced.

  In addition to the wax and EVA, the wax composition may further include a plasticizer, a stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a dye, a pigment, a colorant, an inorganic filler, and a flame retardant, if necessary. One or more optional additives selected from the group consisting of a lubricant, a reinforcing material, a processing aid, a slip agent, an anti-tacking agent and a release agent, in an amount that does not affect the dead hold property May be included.

  Examples of the wax composition suitably used in the present invention include a mixture of microcrystalline wax and EVA, such as Toyomelt series manufactured by Toyo Adre Co., Ltd.

  For the production of adhesive paper, a wax composition that is heated and melted to a liquid having a viscosity suitable for coating is coated on one paper by any coating means, and the other paper is laminated to form a wax laminate. To do. After coating, in order to prevent the occurrence of distortion due to shrinkage during solidification of the wax composition, aging in a thermostatic bath may be performed.

  The pasting paper may be produced by coating the wax composition in the state of a wax emulsion that has been melted and emulsified with water, and wet laminating.

The coating amount of the wax is 5 to 100 g / m ² , preferably 10 to 30 g / m ² . When the coating amount is less than 5 g / m ² , sufficient adhesive strength cannot be obtained. In addition, the paper cannot be prevented from returning to its original state, and sufficient dead hold property cannot be obtained. On the other hand, when it exceeds 100 g / m ² , production and processing become difficult, which is not preferable.

  As a method of coating the wax composition, for example, the coating is performed once or a plurality of times by a coating means such as roll coating using a size press roll coater or a gravure roll coater, spray coating, dipping, or coating with a brush. Examples include, but are not limited to, methods.

The thickness of the bonding sheet layer, 55~300g / m ^2, preferably 80~130g / m ^2. When it is thinner than 55 g / m ² , good dead hold property cannot be obtained. ^{On the other hand, if} it is thicker than 300 g / m ² , subsequent processing becomes difficult, which is not preferable.

<3> 1st adhesive bond layer In the laminated body which comprises the lid | cover material of this invention, a bonding paper and a resin film are laminated | stacked through a 1st adhesive bond layer. Although this lamination can be performed by any method, it is preferably performed by a dry lamination method in order to increase the adhesive strength.

  As the dry laminating adhesive for forming the first adhesive layer, any dry laminating adhesive generally used for food packaging can be used. Specifically, polyurethane adhesives, acrylic adhesives, isocyanate adhesives, and the like can be used. Examples of the adhesive preferably used in the present invention include Takelac and Takenate manufactured by Mitsui Chemical Co., Ltd., Tomoflex manufactured by Toyo Morton Co., Ltd., Seika Bond manufactured by Dainichi Seika Kogyo Co., Ltd., DIC Graphics Co., Ltd. ) Dick dry manufactured by Rock Dick, Rock Bond J manufactured by Rock Paint Co., Ltd., Adlock and the like.

  The adhesive for dry lamination can be applied by any coating means such as roll coating using a size press roll coater or gravure roll coater, spray coating, coating with a brush, or the like.

The thickness of the first adhesive layer is 0.5 to 10 g / m ² (when dried), more preferably 1 to 5 g / m ² (when dried). If it is thinner than this, sufficient adhesive strength cannot be obtained, and if it is too thick, there is a concern of residual solvent.

<4> Resin film layer The resin film layer which comprises the cover material of this invention is a layer which consists of a resin film laminated | stacked in order to give intensity | strength to a cover material or to provide various barrier properties.

  As a resin film, arbitrary functional films can be used according to the use of a lid material. Such films include stretched or unstretched polyethylene terephthalate (PET) film, polypropylene (PP) film, polyamide (PA) film, polyvinyl chloride (PVC) film, polyethylene (PE) film, polybutylene terephthalate ( PBT) film, polycarbonate (PC) film, polystyrene (PS) film, normal cellophane (PT), polyvinyl alcohol (PVA) film, ethylene-vinyl alcohol copolymer (EVOH) film, saponified ethylene-vinyl acetate copolymer The film which consists of, etc. are mentioned. In addition, in order to improve the water vapor barrier property and oxygen gas barrier property of the lid member, a vapor deposition film in which an inorganic oxide (silicon oxide, aluminum oxide, etc.) is provided on the above-described film surface by vapor deposition can also be used.

The resin film layer may be composed of a multilayer resin film in which two or more resin films are laminated by a laminating method such as dry lamination, sandwich lamination, or extrusion lamination.
The thickness of the resin film layer is 5 to 50 μm, more preferably 6 to 20 μm. When the resin film layer is too thick, the dead hold property of the laminate is impaired.

<5> Second Adhesive Layer In the laminate constituting the lid member of the present invention, the resin film layer and the sealant layer are laminated via the second adhesive layer. This lamination is performed by applying an anchor coating agent as a second adhesive layer on the bonding surface of the resin film layer and extrusion coating a resin forming a sealant layer thereon. Alternatively, it may be carried out by applying a dry laminating adhesive as a second adhesive layer on one bonding surface, and then laminating the other bonding surface thereon and dry laminating. . As the coating means, any means such as roll coating using a size press roll coater, a gravure roll coater or the like, spray coating, or coating with a brush can be used.

  As the anchor coating agent for forming the second adhesive layer, any known anchor coating agent of polyethyleneimine, polybutadiene, organic titanium, or isocyanate can be used. Moreover, as an adhesive for dry laminate forming the second adhesive layer, a urethane-based adhesive can be suitably used.

The thickness of the second adhesive layer, when using an anchor coating agent, 0.001 to 0.5 g / m ² (dry), more preferably 0.01 to 0.3 g / m ² (dry And when using an adhesive for dry lamination, it is 0.5 to 10 g / m ² (when dried), more preferably 1.0 to 5.0 g / m ² (when dried). If it is thinner than this, sufficient adhesive strength cannot be obtained, and if it is too thick, an effect corresponding to the cost required cannot be obtained.

<6> Sealant layer In the laminate constituting the lid of the present invention, the sealant layer is a layer that forms the innermost layer when used as a lid.

  In the present invention, the sealant layer is, for example, a polyolefin resin such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), or unstretched polypropylene (CPP) excellent in heat sealability, or It is a layer made of an ethylene copolymer resin such as an ethylene-vinyl acetate copolymer (EVA), an ethylene-acrylic acid copolymer (EAA), or an ethylene-methacrylic acid copolymer (EMAA). In order to improve the low temperature sealing property and the easy peel property, these resins may be mixed with an incompatible resin such as polystyrene and polybutene in an arbitrary amount.

  The sealant layer is formed by subjecting the resin constituting the sealant layer to melt extrusion coating on the second adhesive layer made of the anchor coating agent coated on the bonding surface of the resin film layer. Is called. Or you may dry laminate with a resin film layer through the 2nd adhesive bond layer which consists of an adhesive agent for dry laminations using the sealant film which consists of resin which comprises said sealant layer.

  The thickness of the sealant layer is 10 to 100 μm, preferably 30 to 50 μm. If it is thinner than this, sufficient adhesive strength cannot be obtained, and if it is too thick, an effect corresponding to the cost required cannot be obtained.

<7> Lid The lid material of the present invention is a cup-shaped packaging container, particularly a food packaging container, especially a packaging container for sealing the contents of instant foods such as cup ramen and cup fried noodles, confectionery, jelly, etc. It can be suitably used as a lid material. Moreover, since it does not have the layer which consists of aluminum, it is applicable also to the packaging container of the instant food cooked using a microwave oven.

  In order to produce a package filled with the contents by applying the lid material of the present invention to a packaging container, the lid material of the present invention is applied to the opening of the packaging container having a thermoplastic resin layer as the outermost layer. It can be performed by superposing and heat-sealing so that the surface of the sealant layer is in contact.

  Next, the present invention will be specifically described with reference to examples.

[Example 1]
Two sheets of pure white roll paper (Kinshachi made by Daio Paper Co., Ltd.) with a basis weight of 35 g / m ² were prepared, and a wax composition (Toyo Adress Co., Ltd.) was melted by heating on the surface of one of them. Toyomelt R671) was applied at a coating amount of 20 g / m ² , and another imitation paper was laminated thereon and wax-laminated to produce a laminated paper.

Subsequently, on one side of the obtained bonding paper, a two-component curable polyurethane adhesive (manufactured by Mitsui Chemicals, Inc., main agent: Takelac A969 / curing agent: Takenate A5, solid content 2.5 g / m) ² ) was coated, and a PET film (manufactured by Toyobo Co., Ltd., thickness 12 μm) was dry laminated thereon.

Next, a polyethyleneimine-based anchor coating agent (Nippon Catalytic Epomin ^(R) P1000) was applied on the PET film surface of the obtained laminated film at a coating amount of 0.1 g / m ² (when dried). Then, a polyethylene resin (JMX Co., Ltd. SMX Y03) was coated by a melt extrusion coating method to provide a sealant layer, and a laminate constituting the lid of the present invention was produced.

The obtained laminate was punched into a circular shape with a diameter of 100 mm, and a knob piece was provided on a part of the outer periphery to obtain a lid material of the present invention. This was heat-sealed on a flange of a paper cup having a low-density polyethylene resin layer (thickness 20 μm) as the outermost layer with a ring sealer at 160 ° C. for 0.7 seconds at a pressure of 2.9 kgf / cm ² . The resulting package had good sealing properties. Further, when the knob piece was pulled at an angle of 135 ° with respect to the container flange to open the half of the lid, the lid material of the present invention retained the curved opening shape, and the opening point on the container flange (the position where the knob piece was located) ) To the position of 30 mm at a horizontal distance in the opening direction, the lid material and the container flange were not in contact. Further, when the lid member was returned to its original state and resealed, the lid member was held with the opening portion resealed in a smooth state. That is, the lid material of the present invention showed a good dead hold property.

[Example 2]
A lid material of the present invention and a package using the same were produced in the same manner as in Example 1 except that the coating amount of the wax composition was 10 g / m ² . The resulting package had good sealing properties. Further, when the knob piece was pulled at an angle of 135 ° with respect to the container flange to open the half of the lid, the lid material of the present invention retained the curved opening shape, and the horizontal distance from the opening point to the position of 20 mm in the opening direction. The lid material and the container flange were not in contact. Furthermore, when the lid member was returned to its original state and resealed, the reseal smooth state was maintained and good dead hold property was exhibited.

[Example 3]
A lid material of the present invention and a package using the same were produced in the same manner as in Example 1 except that the coating amount of the wax composition was 30 g / m ² . The resulting package had good sealing properties. Moreover, when the knob piece was pulled at an angle of 135 ° with respect to the container flange to open the half of the lid, the lid material of the present invention retained the curved opening shape, and the horizontal distance from the opening point to the position of 30 mm in the opening direction. The lid material and the container flange were not in contact. Furthermore, when the lid member was returned to its original state and resealed, the reseal smooth state was maintained and good dead hold property was exhibited.

[Example 4]
A lid material of the present invention and a package using the same were produced in the same manner as in Example 1 except that pure white roll paper (Daiou Paper Co., Ltd. Kinshachi) having a basis weight of 30 g / m ² was used. The resulting package had good sealing properties. Moreover, when the knob piece was pulled at an angle of 135 ° with respect to the container flange to open the half of the lid, the lid material of the present invention retained the curved opening shape, and the horizontal distance from the opening point to the position of 30 mm in the opening direction. The lid material and the container flange were not in contact. Furthermore, when the lid member was returned to its original state and resealed, the reseal smooth state was maintained and good dead hold property was exhibited.

[Comparative Example 1]
A lid and a package using the same in the same manner as in Example 1 except that a high-quality paper having a basis weight of 81.4 g / m ² (manufactured by Nippon Paper Industries Co., Ltd.) was used instead of the bonding paper. Manufactured. When the lid of the obtained package was half opened, the dead hold property did not appear, the lid material and the container flange contacted at the position of the opening point (0 mm), and the lid material closed the opening.

[Comparative Example 2]
Instead of the wax composition, a two-component curing type polyurethane adhesive (manufactured by Mitsui Chemicals, Ltd., main agent: Takelac A969 / curing agent: Takenate A5, solid content 4.0 g / m ² ) Except having bonded, it carried out similarly to Example 1, and manufactured the cover material and the package using the same. When the lid of the obtained package was half opened, the dead hold property did not appear, the lid material and the container flange contacted at the position of the opening point (0 mm), and the lid material closed the opening.

[Comparative Example 3]
A lid and a package using the same were produced in the same manner as in Example 1 except that the coating amount of the wax composition was 3.0 g / m ² . When the lid of the obtained package was half opened, the dead hold property did not appear, the lid material and the container flange contacted at the position of the opening point (0 mm), and the lid material closed the opening.

  Since the lid according to the present invention has the above-described characteristics, the lid is attached to an instant food cup container in which the lid is greatly opened and powder soup or ingredients need to be put into the container. It becomes possible to apply suitably. Moreover, since the layer which consists of aluminum is not provided, it becomes a cover material applicable also to the instant food cooked using a microwave oven.

1. 1. Laminating paper layer First adhesive layer3. Resin film layer 4. Second adhesive layer5. Sealant layer a1. First paper layer a2. A second paper layer b. Wax layer

Claims (4)

At least a cover material composed of a laminate having a bonding paper layer, a first adhesive layer, a resin film layer, a second adhesive layer, and a sealant layer in this order,
The bonding paper layer is a layer having two or more paper layers and a wax layer that is positioned between the paper layers and bonds these layers.
The said laminated body does not have a layer which consists of aluminum, The said cover material characterized by the above-mentioned.   The lid material according to claim 1, wherein the wax layer is made of a wax composition containing a wax selected from the group consisting of mineral wax, petroleum wax, synthetic hydrocarbon wax, and derivatives thereof. .   The lid material according to claim 2, wherein the wax composition further contains an ethylene vinyl acetate copolymer. The bonding paper is a bonding paper composed of two paper layers and a wax layer that is positioned between them and bonds them, and the wax layer has a coating amount of the wax composition of 5 to 5. It forms so that it may become 100 g / m < ² >, The cover material of any one of Claims 1-3 characterized by the above-mentioned.

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