HK1248194A1 - Lid - Google Patents
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- HK1248194A1 HK1248194A1 HK18107693.5A HK18107693A HK1248194A1 HK 1248194 A1 HK1248194 A1 HK 1248194A1 HK 18107693 A HK18107693 A HK 18107693A HK 1248194 A1 HK1248194 A1 HK 1248194A1
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Description
Technical Field
The present invention relates to a lid material in which an opening of a plastic container for storing liquid or seed foods such as yogurt (yogurt), lactic acid bacteria beverages, fruit beverages, etc., powdery foods such as wheat flour, solid foods such as ham, cheese, etc., various pharmaceuticals, etc., is bonded and sealed by hot plate heating or high-frequency induction heating.
Background
Generally, an opening of a container body for containing food or the like is sealed with a lid member having thermal adhesiveness. In recent years, in view of ensuring safety of foods and the like, it has been required that the amount of substances eluted into an organic solvent (the amount of substances eluted into the organic solvent) is small when the covering material is immersed in the organic solvent. As a cover material that meets such a demand, a cover material having a laminated structure of a base material layer such as an aluminum foil, a anchor coat layer such as a urethane resin, a stress relaxation layer such as a polyethylene film, and an ethylene-vinyl acetate resin hot-melt adhesive layer has been proposed (patent document 1).
In this lid material, it is proposed to select a material having a small amount of substance eluted in an organic solvent, as a constituent material of the hot-melt adhesive layer that is in direct contact with the contents contained in the container main body. Specifically, the hot melt adhesive layer is formed by a hot melt adhesive containing 25 to 55 wt% of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 24 to 35 wt% and a melt index of 30 to 400g/10 min, 30 to 65 wt% of a polyethylene wax having a molecular weight of 700 to 3,500 and a melting point of 95 to 125 ℃, and 10 to 30 wt% of a polymer-based adhesive imparting agent having a molecular weight of 700 to 1,400 and a softening point of 100 to 125 ℃.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open No. 10-156995.
Disclosure of Invention
Problems to be solved by the invention
However, the lid material proposed in patent document 1 has very small elution amount of substances eluted in edible fats and oils and ethanol, and has no problem at all in ordinary use, but there are cases where: the elution amount of substances in hexane (elution amount in hexane) is larger than the elution amount of substances in edible fats and oils and ethanol. Therefore, it is considered that the amount of elution into hexane is reduced by relatively reducing the content of impurities having a low molecular weight by changing the respective constituent materials of the hot melt adhesive to materials having a higher molecular weight.
However, if a material having a higher molecular weight is used as the material constituting the hot melt adhesive, the sealing property of the hot melt adhesive layer of the lid material is lowered, and therefore, the sealing strength may be lowered under the same sealing conditions as those of the conventional art. To avoid this, it is considered to make the sealing conditions strict, but it is very difficult to find the most suitable sealing strip in the strict conditions.
The present invention is to solve the problems of the conventional techniques described above, and an object thereof is to: in a cover material obtained by laminating a base material layer, a anchor coat layer, a stress relaxation layer, and a hot-melt adhesive layer in this order, even when the amount of elution in an organic solvent is suppressed by changing the material constituting the hot-melt adhesive layer to a material having a higher molecular weight, good sealing can be achieved under the same sealing conditions as in the conventional case.
Means for solving the problems
The present inventors have found that when a cover material obtained by laminating a base material layer, a anchor coat layer, a stress relaxation layer, and a hot-melt adhesive layer in this order is formed from a hot-melt adhesive obtained by blending a specific amount of talc into a mixture obtained by mixing an ethylene-vinyl acetate copolymer, an adhesion-imparting agent, and a wax in specific ranges, even when a material having a higher molecular weight is selected as a material constituting the hot-melt adhesive in order to reduce the amount of the cover material eluted into an organic solvent, the sealability is not reduced, and have completed the present invention.
Specifically, the present invention provides a cover material comprising at least a base material layer, a anchor coat layer, a stress relaxation layer, and a hot-melt adhesive layer, wherein the layers are laminated in the order described above, the hot-melt adhesive constituting the hot-melt adhesive layer contains 20 to 50 mass% of an ethylene-vinyl acetate copolymer as a component (a), and the following components (B) to (D) are contained in the following parts by mass with respect to 100 parts by mass of the component (a).
(A) 100 parts by mass of an ethylene-vinyl acetate copolymer;
(B) 8 to 80 parts by mass of a tackiness imparting agent;
(C) 85-230 parts by mass of wax; and
(D) 15-200 parts by mass of talc.
The present invention also provides a packaged food comprising a food container having an opening portion formed with a flange portion, a liquid or solid food contained in the food container, and a lid member bonded to the flange portion formed in the opening portion of the food container, wherein the lid member is the lid member described above, and the lid member is bonded to the flange portion of the opening portion from the hot-melt adhesive layer side.
ADVANTAGEOUS EFFECTS OF INVENTION
In the cover material of the present invention in which the base material layer, the anchor coating layer, the stress relaxation layer, and the hot-melt adhesive layer are laminated in this order, a hot-melt adhesive obtained by blending a specific amount of talc into a mixture obtained by mixing an ethylene-vinyl acetate copolymer, a tackiness imparting agent, and a wax in specific amounts is used as the hot-melt adhesive for forming the hot-melt adhesive layer in consideration of sealability and an amount of elution in an organic solvent. Therefore, even when a material having a higher molecular weight is selected as a material constituting the hot melt adhesive in order to reduce the elution amount of the lid material in the organic solvent, the sealing property can be prevented from being degraded.
Drawings
FIG. 1 is a schematic cross-sectional view of a lid member according to the present invention.
FIG. 2 is a graph showing the sealing strength characteristics by hot plate heating when focusing attention on the kind of filler.
Fig. 3 is a graph showing the sealing strength characteristics by high-frequency induction heating when focusing attention on the type of filler.
FIG. 4 is a graph showing seal strength characteristics by hot plate heating when focusing attention on the amount of talc added.
FIG. 5 is a graph showing seal strength characteristics by high-frequency induction heating with attention paid to the amount of talc added.
FIG. 6 is a graph showing seal strength characteristics by heating with a hot plate, focusing on the average particle diameter of talc.
FIG. 7 is a graph showing seal strength characteristics by high-frequency induction heating with attention paid to the average particle diameter of talc.
Detailed Description
Hereinafter, the lid material of the present invention will be described with reference to the drawings.
< covering Material >
As shown in fig. 1, the cover material 10 of the present invention has a structure in which a base material layer 1, a anchor coat layer 2, a stress relaxation layer 3, and a hot-melt adhesive layer 4 are laminated in this order. The lid 10 is a material for sealing the opening of the container body by sealing. Examples of the material constituting such a container body include plastics such as polystyrene, polypropylene, polyethylene, polyvinyl chloride, polycarbonate, and polyacrylonitrile, composite laminates lined with these plastics, metals, polyethylene laminated papers, and glass.
"substrate layer 1"
The base material layer 1 is a main layer for imparting initial mechanical strength to the cover material, and may be formed in the same configuration as the base material layer of the conventional cover material. For example, the metal or alloy film may be selected from films of metals such as iron, stainless steel, copper, aluminum, and gold, films of ceramics such as silicon nitride, films of resins such as polyethylene terephthalate, polyurethane, polystyrene, polyamide, and polyimide, paper sheets, and composite materials obtained by laminating these materials. In particular, in order to impart high-frequency induction heating characteristics to the cover material 10, it is preferable to use a metal thin film as the base material layer 1, which generates heat by inducing an eddy current in itself when a high-frequency wave is applied thereto. Among them, aluminum foil is preferable from the viewpoints of formability, suitability for high-frequency heating, and economy.
The thickness of the base layer 1 is usually 5 to 300 μm in consideration of mechanical strength and the material used, and for example, when a metal thin film such as aluminum foil is used, the thickness is preferably 5 to 50 μm, more preferably 20 to 40 μm in consideration of high-frequency induction heating characteristics.
The base layer 1 can be formed by a known method depending on the kind and thickness of the material. In the case of a thin film of a metal or an alloy, the thin film can be formed by a cold rolling method, a vacuum deposition method, an electroless plating method, an electrolytic plating method, or the like. In the case of a resin film, the film can be formed by a melt extrusion molding method, a solution casting method, a calendering method, or the like. Further, the film of the resin may be subjected to stretching treatment.
The conditions for high-frequency induction heating include conditions of 140W and 1.4 seconds, and may be appropriately changed depending on the layer structure and the material used.
"anchor coating 2"
The anchor coat layer 2 is a layer for bringing the base layer 1 and the stress relaxation layer 3 into close contact with each other, and can be selected according to the material thereof.
As the anchor coat layer 2, a layer formed of a modified polyolefin-based anchor coat agent, a polyester-based anchor coat agent, or a polyurethane-based anchor coat agent modified with chlorine or acid can be used. The anchor coat layer 2 may contain additives such as various fillers within a range that does not interfere with adhesion between the base layer 1 and the stress relaxation layer 3.
In the layer thickness of the anchor coat layer 2, if the layer thickness becomes too thin, the seal strength decreases, and if the layer thickness becomes too thick, cohesive failure in the interior of the anchor coat layer 2 occurs () The sealing strength tends to be lowered, and therefore, it is preferably 0.1 to 6.0. mu.m, more preferably 0.2 to 4.5. mu.m.
The keycoat 2 may be formed using a solution coating method.
"stress relaxation layer 3"
The stress relaxation layer 3 enhances the mechanical strength of the cover material, relaxes the stress during high-frequency heating, and also functions as a layer for suppressing application of excessive heat to the hot-melt adhesive layer 4 and firmly bonding the hot-melt adhesive layer 4 to the back surface of the cover material. As such a stress relaxation layer 3, a resin layer made of a polyolefin-based thermoplastic resin such as polyethylene or polypropylene, or a resin layer made of a polyester-based thermoplastic resin such as polyethylene terephthalate can be used. In view of stability of high-frequency sealing strength and the like, a polyethylene layer, particularly a non-stretched polyethylene layer, may be preferably applied.
The thickness of the stress relaxation layer 3 is preferably 6 to 60 μm, and more preferably 9 to 50 μm. When the amount is within the above range, not only sufficient stress relaxation heat relaxation can be achieved, but also sufficient heat can be conducted from the base material layer 1 to the hot-melt adhesive layer 4.
When the stress relaxation layer 3 is a polyethylene layer, the thickness thereof is preferably 10 to 50 μm, more preferably 15 to 40 μm, in view of high-frequency sealing properties and moldability.
As a method for providing the stress relaxation layer 3 on the anchor coat layer 2, a known method can be used. For example, the material constituting the stress relaxation layer 3 may be directly melt-extruded and laminated on the anchor coat layer 2, or a film made of the material constituting the stress relaxation layer 3 may be dry-laminated on the anchor coat layer 2.
"Hot melt adhesive layer 4"
The hot-melt adhesive layer 4 is not only a layer that is bonded to the opening of the container body by heat conducted from the base material layer 1, but also a layer that is in contact with the contents stored in the container body.
The adhesion amount of the hot-melt adhesive layer 4 is preferably 3 to 40g/m2More preferably 5 to 30g/m2. When the amount is within the above range, sufficient high-frequency sealing properties (particularly sealing strength) can be obtained by high-frequency heating, the lid material can be stably peeled, and the amount of elution in the organic solvent can be reduced.
The formation of the hot-melt adhesive layer 4 can be performed by a known method such as a gravure roll coating method.
The hot-melt adhesive layer 4 is a layer that comes into contact with the contents contained in the container main body, and therefore is required to be made of an adhesive material that can be adhered to the container main body to be used and is less likely to dissolve out of the contents. In the present invention, the adhesive is formed of a hot melt adhesive containing the following components (a) to (D).
(A) Ethylene-vinyl acetate copolymer
(B) Adhesion imparting agent
(C) Wax
(D) Talc.
< ingredient (A) >)
The reason why the ethylene-vinyl acetate copolymer of the component (a) functions as a main component of the hot melt adhesive is that it is easily adhered to metal, resin, glass, etc., and is easily compatible with wax, etc.
The content of the ethylene-vinyl acetate copolymer as the component (A) in the hot-melt adhesive is 20 to 50% by mass, preferably 25 to 45% by mass. When the amount is within the above range, the heat sealing strength is not lowered, and the amount of elution in an organic solvent can be suppressed.
In the present invention, an ethylene-vinyl acetate copolymer having the following characteristics (a 1) to (a 3) is preferably used.
(characteristic (a 1): vinyl acetate content)
The vinyl acetate content of the ethylene-vinyl acetate copolymer is preferably 14 to 41 mass%, more preferably 19 to 33 mass%. When the amount is within the above range, the sealing strength is not lowered, and the amount of elution in an organic solvent can be suppressed. The vinyl acetate content can be measured in accordance with JIS K6924-2.
(characteristic (a 2): MFR value)
The ethylene-vinyl acetate copolymer preferably has an MFR value (JIS K7210) of 5 to 400g/10 min, more preferably 5 to 150g/10 min. When the amount is within the above range, the amount of elution in the organic solvent can be suppressed without impairing the coatability of the hot-melt adhesive. The MFR value can be measured in accordance with JIS K7210.
(Property (a 3): Vicat softening point)
The Vicat softening point of the ethylene-vinyl acetate copolymer is preferably 25 to 75 ℃, and more preferably 30 to 65 ℃. When the amount is within the above range, the amount of elution in the organic solvent can be suppressed, and the decrease in the sealing strength can be suppressed. The Vicat softening point can be measured according to JIS K7206.
Specific examples of the ethylene-vinyl acetate copolymer having the above-described characteristics (a 1) to (a 3) include "エバフレックス (registered trademark) EV420 and EV 220" manufactured by sanjing seedtree デュポンポリケミカル (strain) "and" ウルトラセン (registered trademark) 750 "manufactured by east ソー (strain), and the like. For example, characteristics (a 1) to (a 3) of "エバフレックス EV 420" are as follows.
Characteristic (a 1): vinyl acetate content 19% by mass
Characteristic (a 2): MFR value 150g/10 min
Characteristic (a 3): vicat softening point 42 ℃.
< ingredient (B) >)
The adhesiveness-imparting agent of the component (B) is a component that imparts adhesiveness to the hot-melt adhesive.
The content of the tackiness imparting agent of the component (B) in the hot-melt adhesive is 8 to 80 parts by mass, preferably 14 to 60 parts by mass, per 100 parts by mass of the ethylene-vinyl acetate copolymer of the component (A). When the content is within the above range, the decrease in sealing strength can be suppressed, and the amount of elution in an organic solvent can be suppressed.
As the tackiness imparting agent, known tackiness imparting agents can be used, and examples thereof include alicyclic saturated hydrocarbon resins, aliphatic aromatic copolymer resins, terpene resins, and rosin resins. Among them, a rosin resin is preferably used from the viewpoint of improving the adhesive strength.
In the present invention, the tackiness-imparting agent represented by such a rosin-based resin has the following characteristics (b 1).
(characteristic (b 1): softening point)
The softening point of the tackiness imparting agent represented by a rosin-based resin is preferably 80 to 150 ℃, more preferably 85 to 130 ℃. When the amount is within the above range, the amount of elution in the organic solvent can be suppressed from increasing, and the sealing strength can be suppressed from decreasing. The softening point can be determined by the ring and ball method.
Specific examples of the tackiness-imparting agent having the above-described characteristic (b 1) include "アルコン (registered trademark) P-125" (softening point 125 ℃) manufactured by seikaga chemical industry, "クイントン (registered trademark) D100" (softening point 99 ℃) manufactured by japan ゼオン, and "スーパーエステル a-115" (softening point 108 ℃) manufactured by seikaga chemical industry, and "ペンセル (registered trademark) AZ" (softening point 95 ℃) and ハリマ converted into "ハリタック ER 95" (softening point 85 ℃) manufactured by seikaga chemical industry.
< ingredient (C) wax >
The wax as the component (C) is a component for reducing the viscosity of the hot melt adhesive and imparting wettability.
The wax content of the component (C) in the hot-melt adhesive is 85 to 230 parts by mass, preferably 110 to 200 parts by mass, per 100 parts by mass of the ethylene-vinyl acetate copolymer of the component (A). When the viscosity is within the above range, the coating workability due to the increase in viscosity of the adhesive material can be suppressed from decreasing, and the coating workability due to the decrease in viscosity can be suppressed from decreasing, and the seal strength can be suppressed from decreasing.
As the wax, a known wax can be used. Examples thereof include natural waxes such as refined beeswax, refined carnauba wax, refined montan wax, paraffin wax, and microcrystalline wax; synthetic waxes such as polyethylene wax, polypropylene wax, Fischer-Tropsch wax, and the like. Among these, synthetic waxes are preferable, and fischer-tropsch waxes are more preferable, from the viewpoint of stability of melting point and molecular weight distribution.
Such a wax preferably has the following characteristic (c 1).
(characteristic (c 1): melting Point)
The melting point of the wax represented by polyethylene wax is preferably 80 to 130 ℃, more preferably 85 to 120 ℃. When the amount is within the above range, the amount of elution in the organic solvent can be suppressed, and the lowering of the sealing property at low temperatures can be suppressed. The melting point can be measured by the DSC method.
Specific examples of the wax having the above-described characteristic (c 1) include "ネオワックス L" (melting point 110. + -. 10 ℃ C.) manufactured by ヤスハラケミカル (manufactured by Ikeka corporation), "ハイワックス NL 900" (melting point 103 ℃ C.) manufactured by Mitsui Chemicals (manufactured by Ikeka corporation), "FT 105" (melting point 102 ℃ C.) manufactured by Japan wax (manufactured by Ikeka corporation), and the like.
< ingredient (D) Talc >
The hot melt adhesive used in the present invention contains talc as the component (D). Talc is a component that has excellent dispersibility in other resin components, can improve the cohesive force of the hot-melt adhesive, and is used for transferring heat from the base material layer 1 to the hot-melt adhesive layer 4 without excessively diffusing the heat.
The content of talc as the component (D) in the hot-melt adhesive is 15 to 200 parts by mass, preferably 60 to 170 parts by mass, per 100 parts by mass of the ethylene-vinyl acetate copolymer as the component (A). When the amount is within the above range, not only a decrease in sealing properties at low temperatures but also an amount of elution in an organic solvent can be suppressed, and a decrease in compatibility with other compounds such as resins can be suppressed, and a decrease in coatability due to a decrease in fluidity can be suppressed.
In the present invention, talc having the following characteristics (d 1) to (d 3) is preferably used.
(characteristic (D1): particle diameter (D50))
The particle diameter (D50) (median particle diameter) of the talc is preferably 0.1 to 50 μm, more preferably 0.5 to 25 μm. When the amount is within the above range, the volume of the particles can be suppressed from increasing, the production of the coating material can be facilitated, and the decrease in thermal conductivity and the decrease in heat sealability can be suppressed. The particle diameter (D50) can be measured by a laser diffraction method.
(characteristic (d 2): apparent density)
The apparent density of the talc is preferably 0.05 to 0.7g/mL, more preferably 0.08 to 0.6 g/mL. When the amount is within the above range, the volume of the particles can be suppressed from increasing, the production of the coating material can be facilitated, and the decrease in thermal conductivity and the decrease in heat sealability can be suppressed. The apparent density can be measured in accordance with JIS K5101.
(characteristic (d 3): specific surface area)
The preferable specific surface area of the talc is 1.5 to 100m2A concentration of 2.5 to 40 m/g is more preferable2(ii) in terms of/g. When the amount is within the above range, the decrease in thermal conductivity and the decrease in sealing strength can be suppressed, and the coating material can be easily produced. The specific surface area can be measured by the BET method.
Specific examples of talc having the above-described characteristics (D1) to (D3) include "ミクロエース (registered trademark) K-1" (particle diameter (D50) 8.0 μm, apparent density 0.25g/mL, specific surface area 7.0m, manufactured by Nippon タルク K2(g) 'MS-K' (particle diameter (D50): 16 μm, apparent density 0.40g/mL, specific surface area 4.0 m) manufactured by Japan タルク (Ltd.)2(g) 'MS-KY' (particle diameter (D50) < 25 μm >, apparent density 0.55g/mL, specific surface area 2.5 m) manufactured by Japan タルク (Ltd.)2,/g), etc.
The hot-melt adhesive layer 4 described above can be formed by applying a hot-melt adhesive to the stress relaxation layer 3 and cooling it by a known application method such as a gravure coater, a comma coater, or a die coater. In this case, the shape may be a flat film, an embossed film, a dot, or a line.
Printing layer and protective layer "
The cover material of the present invention may be provided with a printed layer formed on the outer surface of the base material layer 1 by a known method. Further, a transparent protective layer may be provided. If necessary, the outer surface of the cover on the base material layer 1 side may be embossed. If necessary, a printing layer may be provided on the surface on which the hot-melt adhesive layer is processed, or a printing layer may be provided on the base layer.
Sealing characteristics "
The lid member of the present invention has the structure described above, and therefore exhibits excellent sealing properties (strength) when sealing treatment is performed by hot plate heating, high-frequency induction heating, ultrasonic heating, or the like. For example, when the heating is performed by a hot plate, the sealing conditions include a sealing temperature of 80 to 240 ℃, a sealing time of 0.5 to 3 seconds, and a sealing pressure of 0.1 to 0.5 MPa. When high-frequency induction heating is used, the sealing conditions include a power of 110 to 170W, a sealing time of 0.5 to 1.5 seconds, and a sealing pressure of 0.1 to 0.3 MPa.
(amount of elution in organic solvent)
The lid material of the present invention is formed of a hot melt adhesive layer 4 which is in contact with the contents of a container, the hot melt adhesive layer being formed of a mixture obtained by mixing an ethylene-vinyl acetate copolymer, a tackiness imparting agent and a wax in a specific range of amounts, and a specific amount of talc. Therefore, the sealing property cannot be lowered, and therefore, even when a material having a higher molecular weight is selected as a material constituting the hot-melt adhesive, the amount of the lid material released from the organic solvent can be reduced. In particular, the lid material of the present invention can be made such that the residue (the amount eluted in heptane) is 30 μ g/mL or less in an oily food elution test based on the evaporation residue test method (elution liquid n-heptane) prescribed in a standard test of packaging of instruments and containers according to the Japanese food sanitation Law Standard (Showa 34-Mitsu showa Kagaku Notification No. 370).
In addition, the lid material of the present invention can be made such that the residue (elution amount in hexane) obtained by the test method described below is 30mg/L or less.
(Evaporation residue of n-hexane-based dissolution test)
A test solution was prepared by immersing a sample cut into a size of 10cm square in 200mL of n-hexane for 2 hours in a whole area at 25 ℃ according to the national Standard of the people's republic of China "analytical method of hygienic Standard for polyethylene, polystyrene, and polypropylene molded articles for food packaging" (GB/T5009.60-2003). The test solution was transferred to an eggplant type flask, and concentrated under reduced pressure until the residual volume became several mL. To the obtained concentrated solution, washing liquids obtained by washing the inner wall of the flask used for the concentration under reduced pressure 2 times with 5mL of n-hexane were added, transferred to an evaporation dish of known weight which was dried at 105 ℃ in advance, and evaporated to dryness. Then, the mixture was dried at 105 ℃ for 2 hours and then cooled naturally in a desiccator. After natural cooling, the mass difference between the evaporation dish before and after the test was determined by weighing, and the amount (mg) of the evaporation residue per 1L of the test solution was calculated.
Method for manufacturing cover material "
As already explained, the lidstock of the present invention may be manufactured by: the anchor coat layer 2, the stress relaxation layer 3, and the hot melt adhesive layer 4 are formed on the base layer 1 by a known method.
< use of cover Material >
The lid of the present invention is preferably applicable to a food container having an opening portion formed with a flange portion, a liquid or solid food contained in the food container, and a lid bonded to the flange portion formed at the opening portion of the food container. In this case, the cover material is applied to the flange portion of the opening portion from the adhesive layer side, and is thermally bonded by high-frequency induction heating. The "packaged food" obtained in the above manner is also a mode of the present invention. The food container may be a well-known food container made of polystyrene.
The term "liquid or solid" in the liquid or solid food means a state in which the shape of the food as the content is deformed (e.g., flowed out or flowed) or a state in which the shape of the food as the content is not deformed (e.g., solid) when the container is tilted. Examples of such liquid or solid foods include dairy products such as yogurt and lactic acid drinks, jam products, soups, curry pastes (currysauce), stews, and seasoned rice foods (ふりかけ), but are not limited thereto.
Examples
The present invention will be described in more detail below with reference to examples and comparative examples.
Example 1
(AL foil/anchor coat/LDPE/Hot melt adhesive layer)
A2-liquid curable adhesive (isocyanate-based) for extrusion and lamination was applied to one surface of a 30 μm thick aluminum foil (alloy No. 1N30 defined in JIS H4160) by means of a gravure coater, and dried to form a 0.35 μm thick anchor coat layer, on which a 30 μm thick low-density polyethylene (MFR = 7) was extruded and laminated, and further, the applied amount was 12.7g/m by means of a gravure coater2In the embodiment of (1), a hot-melt adhesive of the following formulation was applied in a dot form to obtain a lid material.
[ Table 1]
| Composition (I) | Compounding amount (parts by mass) |
| Ethylene-vinyl acetate copolymer (vinyl acetate content 28%, MFR value 18g/10 min, Vicat softening point 40 ℃ C.) | 35 |
| Adhesion imparting agent (rosin ester resin having a softening point of 85 ℃ C.) | 5 |
| Wax (melting point 102 ℃ Fischer-Tropsch wax) | 60 |
| Talc (particle diameter D50 of 16 μm, apparent density of 0.40g/mL, specific surface area of 4.0m2/g） | 30 |
Comparative example 1
Talc was not added to the hot melt adhesive, and the amount of the hot melt adhesive applied was 12.1g/m2Except for this, a hot melt adhesive was prepared in the same manner as in example 1, and a lid material was produced.
Comparative example 2
Calcium carbonate (light calcium carbonate, average particle diameter 2.0X 0.4 μm) was used in place of talc, and the amount of hot melt adhesive applied was 14.4g/m2Except for this, a hot melt adhesive was prepared in the same manner as in example 1, and a lid material was produced.
Comparative example 3
Rutile type titanium oxide (average particle diameter 0.25 μm, specific gravity 4.1, oil absorption 19g/100 g) was used in place of talc, and the amount of hot melt adhesive applied was 14.6g/m2Except for this, a hot melt adhesive was prepared in the same manner as in example 1, and a lid material was produced.
Comparative example 4
Anatase type titanium oxide (average particle diameter 0.25 μm, oil absorption 25g/100 g) was used in place of talc, and the amount of hot melt adhesive applied was 14.0g/m2Except for this, a hot melt adhesive was prepared in the same manner as in example 1, and a lid material was produced.
Comparative example 5
Kaolin (average particle diameter: 0.4 μm, oil absorption: 43g/100 g) was used in place of talc, and the amount of the hot melt adhesive applied was 12.2g/m2Except for this, a hot melt adhesive was prepared in the same manner as in example 1, and a lid material was produced.
Comparative example 6
Silica (average particle size of 3.5 to 4.3 μm, oil absorption of 300 ℃; E-350mL/100g (linseed oil)) 10 parts by mass in place of talc, and the coating amount of the hot melt adhesive was made 11.8g/m2Except for this, a hot melt adhesive was prepared in the same manner as in example 1, and a lid material was produced.
(evaluation test)
Sealing strength based on hot plate heating "
The lid materials obtained in example 1 and comparative examples 1 to 6 were cut into strips each having a length of 10cm and a width of 15mm, and test pieces were prepared. The end portion of the test piece was sealed to a polystyrene plate at a sealing temperature, a sealing time of 1 second, and a sealing pressure of 0.2MPa in Table 2, respectively, for 20 mm. The other end of the test piece having an end sealed to the polystyrene plate was set in a tensile tester (オートグラフ (registered trademark) AGS-500NJ, manufactured by shimadzu corporation), and a 180 ° peel test was performed at a peel speed of 300 mm/min for 5 times. The average values of the obtained 5-time seal strengths are shown in table 2 and fig. 2. Under the sealing conditions of this time, it is preferable that the sealing strength is 10N/15mm width or more at the sealing temperature of 140 ℃ from the practical viewpoint. Further, it is more preferably 5N/15mm width or more at a sealing temperature of 100 ℃.
[ Table 2]
Sealing strength based on high-frequency induction heating "
The lid materials obtained in example 1 and comparative examples 1 to 6 were cut into a circular shape having an outer diameter of 38mm, and attached to a polystyrene container having a capacity of 65mL and a bottle shape having an opening outer diameter of 24mm and an opening inner diameter of 20mm, and sealed at a power of 110 to 170W, a sealing pressure of 0.05MPa, and a sealing time of 1.4 seconds. After sealing, the end of the lid material was peeled off at a speed of 300 mm/min in a direction of 45 degrees with respect to the surface of the container in which the lid material was sealed, and the maximum value at the time of peeling was defined as the sealing strength. The average of 5 peeling tests was used. From a practical viewpoint, it is preferable to maintain the sealing strength of 7N or more at a power of 125W. The obtained results are shown in table 3 and fig. 3.
[ Table 3]
Examples 2 to 6
The amount of talc added was changed from 30 parts by mass to 5 parts by mass (example 2), 10 parts by mass (example 3), 20 parts by mass (example 4), 50 parts by mass (example 5), or 70 parts by mass (example 6), and the amount of hot melt adhesive applied was changed from 12.7g/m2Respectively changed to 12.5g/m2、14.5g/m2、14.0g/m2、14.2g/m2Or 14.8g/m2Except for this, a hot melt adhesive was prepared in the same manner as in example 1, and a lid material was produced.
(evaluation test)
Tests of "seal strength by hot plate heating" and "seal strength by high-frequency induction heating" were performed on the lid materials of examples 2 to 6 in the same manner as in example 1. The results obtained in the former are shown in table 4 and fig. 4 together with the results of example 1 and comparative example 1, and the results obtained in the latter are shown in table 5 and fig. 5 together with the results of example 1 and comparative example 1.
[ Table 4]
[ Table 5]
Examples 7 and 8
Average particle diameter (D)50) The talc having a particle size of 16 μm (example 1) was changed to talc having an average particle size (D50) of 8 μm (apparent density: 0.25g/mL, specific surface area: 7.0m2(example 7) or talc having an average particle diameter (D50) of 25 μm (apparent density: 0.55g/mL, specific surface area: 2.5 m)2(g) (example 8) and the amount of hot melt adhesive applied was adjusted from 12.7g/m2Respectively changed into 12.4g/m2Or 12.8g/m2Except for this, a hot melt adhesive was prepared in the same manner as in example 1, and a lid material was produced.
(evaluation test)
The lid materials of examples 7 and 8 were tested for "seal strength by hot plate heating" and "seal strength by high-frequency induction heating" in the same manner as in example 1. The results obtained in the former are shown in table 6 and fig. 6 together with the results of example 1, and the results obtained in the latter are shown in table 7 and fig. 7 together with the results of example 1.
[ Table 6]
[ Table 7]
"elution amount in n-hexane"
The lid materials of comparative example 1 (no talc), example 1 (30 parts by mass of talc), example 5 (50 parts by mass of talc) and example 6 (70 parts by mass of talc) were cut into a size of 10cm square, and test pieces were prepared. The test solution was prepared by immersing the test piece in 200mL of n-hexane for 2 hours at 25 ℃ for the whole face according to the national Standard of the people's republic of China "analytical method for sanitary Standard of polyethylene, polystyrene, and polypropylene molded articles for food packaging" (GB/T5009.60-2003). The obtained test solutions were transferred to eggplant type flasks, respectively, and concentrated under reduced pressure until the residual volume became several mL. To the obtained concentrated solution, washing liquids obtained by washing the inner wall of the flask used for the concentration under reduced pressure 2 times with 5mL of n-hexane were added, transferred to an evaporation dish of known weight which was dried at 105 ℃ in advance, and evaporated to dryness. Then, the mixture was dried at 105 ℃ for 2 hours and then cooled naturally in a desiccator. After natural cooling, the mass difference between the evaporation dish before and after the test was determined by weighing, and the amount (mg) of the evaporation residue per 1L of the test solution was calculated. The obtained results are shown in table 8.
[ Table 8]
| Elution amount of n-hexane | |
| Comparative example 1 No Talc | 36 mg/L |
| Example 1 Talc 30 parts by mass | 28 mg/L |
| Example 5 Talc 50 parts by mass | 24 mg/L |
| Example 6 Talc 70 parts by mass | 21 mg/L |
(examination)
As is clear from the results in table 2 (fig. 2) and table 3 (fig. 3), talc improves the sealing strength by hot plate heating and high frequency induction heating among the various fillers. In particular, in the case of example 1 using talc, the sealing strength of 15.2N/15mm width was obtained at 140 ℃ by heating with a hot plate, and the sealing strength was maintained superior to those of comparative examples 2 to 6 using other fillers. In the high-frequency induction heating, the excellent sealing strength was also maintained as compared with other fillers.
As is clear from the results of table 4 (fig. 4) and table 5 (fig. 5), the following tendency is present: when the talc content is increased from 5 parts by mass, the seal strength is improved (examples 1 to 6). In the case of hot plate heating, it is known that when 5 parts by mass or more of talc is added, the seal strength at 140 ℃ is 10N/15mm width or more, which is a preferable seal strength, and even if 100 ℃, when the amount of talc added is 20 parts by mass or more, the width is maintained at 5N/15mm or more, and therefore, it is more preferable. In high-frequency induction heating, it is known that by adding 5 parts by mass or more of talc, a sealing strength of 7.1N is maintained even at 125W, which is a low output, and processing can be performed even in a low output region.
As is clear from the results of table 6 (fig. 6) and table 7 (fig. 7), the following tendency is present: when the particle size of talc is small, the seal strength is improved under high seal conditions (examples 1, 7, and 8). Within the range of the experimental results of this time, excellent seal strength can be obtained even under low seal conditions.
From the results in Table 8, it is understood that the amount of n-hexane eluted decreases as the talc content increases. Further, as a result of the evaporation residue test using the dissolution liquid n-heptane in accordance with the standard standards of the food hygiene law, in all of examples 1, 5 and 6, the residue was 20 μ g/mL or less with respect to n-heptane, and excellent quality was maintained with respect to the dissolution of n-heptane based on the standard standards of the food hygiene law.
Industrial applicability
In the cover material of the present invention in which the base material layer, the anchor coat layer, the stress relaxation layer, and the hot-melt adhesive layer are laminated in this order, a hot-melt adhesive obtained by mixing an ethylene-vinyl acetate copolymer, a tackiness imparting agent, and a wax in a specific amount range and a specific amount of talc is used as the hot-melt adhesive for forming the hot-melt adhesive layer, taking into consideration sealability and the amount of elution in an organic solvent. Therefore, even when a material having a higher molecular weight is selected as a material constituting the hot melt adhesive in order to reduce the elution amount of the lid material in the organic solvent, the sealing property can be prevented from being lowered. Therefore, the present invention is useful as a lid material for food containers and pharmaceutical containers.
Drawings
1 base material layer
2 anchor coating
3 stress relaxation layer
4 Hot melt adhesive layer
10 cover material.
Claims (14)
1. A cover material comprising at least a base material layer, a anchor coat layer, a stress relaxation layer, and a hot-melt adhesive layer, wherein the layers are laminated in the order mentioned, the hot-melt adhesive constituting the hot-melt adhesive layer contains 20 to 50 mass% of an ethylene-vinyl acetate copolymer as a component (A), and the following components (B) to (D) are contained in the following parts by mass with respect to 100 parts by mass of the component (A):
(A) 100 parts by mass of an ethylene-vinyl acetate copolymer;
(B) 8 to 80 parts by mass of a tackiness imparting agent;
(C) 85-230 parts by mass of wax; and
(D) 15-200 parts by mass of talc.
2. The lid material according to claim 1, wherein the talc of the component (D) has the following characteristics (D1) to (D3):
(d1) the particle size (D50) is 0.1-50 μm;
(d2) the apparent density is 0.05-0.7 g/mL; and
(d3) the specific surface area is 1.5-100 m2/g。
3. The lid material according to claim 1 or 2, wherein the ethylene-vinyl acetate copolymer of the component (a) has the following characteristics (a 1) to (a 3):
(a1) the vinyl acetate content is 14-41 mass%;
(a2) the MFR value is 5-400 g/10 min; and
(a3) the Vicat softening point is 25-75 ℃.
4. The lid material according to any one of claims 1 to 3, wherein the adhesiveness-imparting agent of component (B) has the following property (B1):
(b1) the softening point is 80-150 ℃.
5. The lid material according to claim 4, wherein the tackiness imparting agent of the component (B) is a rosin-based resin.
6. A lidstock according to any one of claims 1 to 5, wherein the wax of component (C) has the following characteristic (C1):
(c1) the melting point is 80-130 ℃.
7. A capstock according to any one of claims 1 to 6, wherein the wax of component (C) is a synthetic wax.
8. A lidstock according to claim 7, wherein the synthetic wax is a Fischer-Tropsch wax.
9. The covering material according to any one of claims 1 to 8, wherein the base material layer has a layer thickness of 5 to 300 μm, the anchor coating layer has a layer thickness of 0.1 to 6.0 μm, the stress relaxation layer has a layer thickness of 6 to 60 μm, and the adhesion amount of the hot-melt adhesive layer is 3 to 40g/m2。
10. A lidstock according to any one of claims 1 to 9, wherein,
the base material layer is a metal or alloy film or a resin film,
the cementing coating is a modified polyolefin cementing coating layer, a polyester cementing coating layer or a polyurethane cementing coating layer,
the stress relaxation layer is a polyolefin or polyester thermoplastic resin layer.
11. The lid material according to claim 9 or 10, wherein the base material layer is an aluminum foil 5 to 50 μm thick.
12. The capstock according to claim 9 or 10, wherein the stress relaxation layer is a non-stretched polyethylene layer 10 to 50 μm thick.
13. The covering material according to any one of claims 1 to 12, wherein a printed layer is formed on an outer surface of the base material layer.
14. A packaged food comprising a food container having an opening portion formed with a flange portion, a liquid or solid food contained in the food container, and a lid member bonded to the flange portion formed at the opening portion of the food container, wherein the lid member is the lid member according to any one of claims 1 to 13, and the lid member is bonded to the flange portion of the opening portion from the hot melt adhesive layer side.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015228815A JP6264359B2 (en) | 2015-11-24 | 2015-11-24 | Lid material |
| JP2015-228815 | 2015-11-24 | ||
| PCT/JP2016/083783 WO2017090482A1 (en) | 2015-11-24 | 2016-11-15 | Lid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| HK1248194A1 true HK1248194A1 (en) | 2018-10-12 |
| HK1248194B HK1248194B (en) | 2019-11-01 |
Family
ID=58763143
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| HK18107693.5A HK1248194B (en) | 2015-11-24 | 2016-11-15 | Lid |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JP6264359B2 (en) |
| KR (1) | KR101897943B1 (en) |
| CN (1) | CN108025850B (en) |
| HK (1) | HK1248194B (en) |
| TW (1) | TWI671390B (en) |
| WO (1) | WO2017090482A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6973166B2 (en) * | 2018-02-22 | 2021-11-24 | Ｍｃｐｐイノベーション合同会社 | Adhesive resin composition, adhesive layer and laminate using it |
| CN112739779B (en) * | 2018-09-21 | 2023-02-21 | 三菱瓦斯化学株式会社 | Resin composition, molded article, and use thereof |
| JP7421860B2 (en) * | 2018-12-25 | 2024-01-25 | 株式会社レゾナック・パッケージング | Container lids and packaging |
| JP6994640B2 (en) * | 2020-06-22 | 2022-01-14 | 東洋インキＳｃホールディングス株式会社 | Adhesive resin composition, sheet, lid material, member set and container using the composition |
| KR102335859B1 (en) | 2020-08-13 | 2021-12-06 | 경북대학교 산학협력단 | customized wireless remote controller |
| EP4383691A4 (en) | 2021-11-10 | 2024-12-04 | Samsung Electronics Co., Ltd. | Electronic device comprising adhesive member |
| JP7498389B1 (en) * | 2023-12-21 | 2024-06-12 | ａｒｔｉｅｎｃｅ株式会社 | Hot melt adhesive, lid material using same and component set for sealed container |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3121550B2 (en) * | 1996-11-26 | 2001-01-09 | 大平製紙株式会社 | Composite packaging lid material |
| JPH11156995A (en) * | 1997-09-25 | 1999-06-15 | Daido Steel Co Ltd | Cladding plate, battery case using the same, and manufacturing method thereof |
| JPH11333964A (en) * | 1998-05-27 | 1999-12-07 | Dynic Corp | Rear side adhesive sheet |
| JP5580067B2 (en) * | 2010-02-03 | 2014-08-27 | 東洋モートン株式会社 | Laminated body and lid material using the same |
| PL2583992T3 (en) * | 2011-10-17 | 2014-11-28 | Fuller H B Co | Hollow glass micro particles used as anti-blocking system in hot melts |
| JP5908707B2 (en) * | 2011-12-01 | 2016-04-26 | 昭和電工パッケージング株式会社 | Content adhesion prevention lid |
| JP5946266B2 (en) * | 2011-12-02 | 2016-07-06 | 小林製薬株式会社 | Package |
| JPWO2014024913A1 (en) * | 2012-08-10 | 2016-07-25 | 日本製紙株式会社 | Multi-layer paper container |
| KR20150054784A (en) * | 2012-09-07 | 2015-05-20 | 도판 인사츠 가부시키가이샤 | Cover material and packaging container |
| JP5983241B2 (en) * | 2012-09-25 | 2016-08-31 | 凸版印刷株式会社 | Lid material |
-
2015
- 2015-11-24 JP JP2015228815A patent/JP6264359B2/en active Active
-
2016
- 2016-11-15 KR KR1020187000925A patent/KR101897943B1/en not_active Expired - Fee Related
- 2016-11-15 HK HK18107693.5A patent/HK1248194B/en not_active IP Right Cessation
- 2016-11-15 WO PCT/JP2016/083783 patent/WO2017090482A1/en not_active Ceased
- 2016-11-15 CN CN201680049691.1A patent/CN108025850B/en active Active
- 2016-11-23 TW TW105138397A patent/TWI671390B/en not_active IP Right Cessation
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