JP2011184082A - Content-antisticking lid material and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lid which is applied mainly to a vessel for packaging yoghurt, and can effectively prevent a content or the yoghurt from adhering to the reverse surface of the lid while keeping good heat sealability and sealing performance. <P>SOLUTION: Also an antisticking layer is separately formed on the outer surface of a heat sealable layer 5 laminated on a base material layer 1. The antisticking layer 6 is composed of a mixture composition of a thermoplastic resin binder of an ethylene-vinyl acetate copolymer or the like and a hydrophobic fine particle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat-sealing lid material mainly applied to containers for packaging foods, and more specifically, to prevent adhesion of contents applied to cup-shaped containers for packaging such as yogurt, jelly, pudding, jam, etc. And a manufacturing method thereof.

  This type of heat sealing lid material is generally provided with a heat sealing layer, that is, a heat sealing layer, on an aluminum foil surface side of a base material layer made of a laminate of a base material film and an aluminum foil via an intermediate resin layer. A sealed package is formed by covering the top opening of a cup-shaped container body filled with an object to be packaged such as yogurt and heat-sealing the peripheral part on the upper edge flange part of the container body. It has been.

  Therefore, in such a lid material, good heat-sealing property, sealing property, and appropriate easy peelability for opening are required, and at the same time, the non-adhesiveness of the contents, that is, the lid material on the inner surface side of the container It is desired that the contents can be prevented from adhering to the back surface. If the contents adhere to the back of the lid, fingers, clothes, or the surrounding area may be soiled when opened, resulting in waste due to the loss of the contents, or time and effort to peel off the contents, and an unclean feeling. This is to cause a disadvantage such as hosting.

  Therefore, conventionally, various proposals as shown in Patent Documents 1 to 6 below have been made for cover materials having a content adhesion prevention performance.

JP 2002-37310 A JP 2007-153385 A JP 2008-1000073 A JP 2009-73523 A JP 2009-241943 A Japanese Patent No. 4348401

  The prior arts shown in Patent Documents 1 to 3 are those in which a nonionic surfactant or a hydrophobic additive having an adhesion preventing effect, a wax, or the like is added to the heat sealing layer on one side of the base material. Although the layer itself is intended to impart anti-adhesion performance, all of them are still unsatisfactory in terms of the expected content-preventing effect.

  Further, the prior arts of Patent Documents 4 to 5 are such that a content adhesion preventing layer is additionally formed on the outer surface (surface on the container side) of the heat sealing layer. The adhesion preventing layer is made of wax, And a composition with a solid fine particle filler dispersed in the composition. These prior arts are further improved in the content adhesion preventing effect as compared with the prior arts of Patent Documents 1 to 3, but they are still not sufficient, and in addition, a filler is dispersed in the wax. Therefore, there is a concern that the heat-sealing property of the heat-sealing layer is adversely affected and the sealing property tends to be unstable.

  Further, the prior art disclosed in Patent Document 6 is to form a porous layer having a three-dimensional network structure with very fine oxide particles such as hydrophobic silica on the outer surface of the heat sealing layer.

  Although this prior proposed technique has a very excellent effect in preventing the adhesion of contents, the porous layer made of inorganic fine particles becomes a contaminant in the heat seal portion, and therefore, a stable and uniform sealing around the entire circumference. When it is difficult to obtain adhesive strength and peel resistance, there is a risk that the contents may inadvertently leak from a weak seal strength part, or conversely, when you try to open the lid by strongly pulling a part with a strong seal strength part. However, there is a problem that the contents may be scattered, and further improvement is desired.

  In view of the problems as described above in the prior art, the present invention is intended to further improve them, specifically, while maintaining stable and good heat seal performance, it is excellent in content adhesion prevention performance, In addition, a new improvement technology that can improve the stability and persistence of the content adhesion preventing effect by enhancing the adhesion between the hydrophobic fine particles expressing the adhesion preventing effect and the adhesion between the lid material and the container. The purpose is to provide.

  In order to achieve the above object, the present invention first presents the following means [1] to [7] for the content adhesion preventing lid.

[1] In a lid having at least a base material layer and a heat sealing layer,
An adhesion preventing layer on the outer surface of the heat sealing layer;
The anti-adhesion layer is composed of a mixed composition of a thermoplastic resin binder and hydrophobic fine particles, and the content anti-adhesion cover material.

  [2] The thermoplastic resin binder includes a synthetic resin having adhesiveness to both the heat sealing layer and the hydrophobic fine particles as a main component, and the content adhesion prevention according to [1] above Lid material.

  [3] The thermoplastic resin binder comprises one or more of vinyl acetate-vinyl chloride copolymer, vinyl acetate-vinyl chloride-maleic acid copolymer, and ethylene-vinyl acetate copolymer. The content adhesion preventing lid material according to the above item [1] or [2].

  [4] The above [1] to [3], wherein the blending ratio of the thermoplastic resin binder and the hydrophobic fine particles in the mixed composition is 10 to 90% by weight of the binder and 90 to 10% by weight of the hydrophobic fine particles in the solid content ratio. ] The content adhesion prevention cover material of any one of these.

  [5] The content adhesion preventing lid material according to any one of [1] to [4], wherein the mixed composition contains relatively more hydrophobic fine particles than the thermoplastic resin binder.

  [6] The content adhesion preventing lid material according to any one of [1] to [5], wherein the hydrophobic fine particles have an average particle diameter of 1 nm to 5,000 nm.

  [7] The content adhesion preventing lid material according to any one of [1] to [6], wherein the hydrophobic fine particles are hydrophobic silica.

  The present invention also presents the means of the following items [8] to [12] characterized in the adjustment of the coating liquid, the selection of the solvent, the drying conditions of the coating film, etc. .

[8] A coating solution prepared by dispersing hydrophobic fine particles in an emulsion or a solution of a thermoplastic resin binder on the outer surface of the heat sealing layer of a lid member having at least a base material layer and a heat sealing layer, The content is characterized in that it is coated at 0.1 to 5.0 g / m ² at a temperature of 80 to 140 ° C. and dried for 5 to 30 seconds to form an adhesion preventing layer. A method for manufacturing an adhesion prevention lid.

  [9] The thermoplastic resin binder comprises one or more of vinyl acetate-vinyl chloride copolymer, vinyl acetate-vinyl chloride-maleic acid copolymer, and ethylene-vinyl acetate copolymer. The manufacturing method of the content adhesion prevention lid | cover material of previous clause [8].

  [10] The method for manufacturing a content adhesion preventing lid material according to [8] or [9] above, wherein the coating liquid uses a solvent having a polar group.

  [11] The method for producing a content adhesion preventing lid material according to [10], wherein the solvent is alcohol.

  [12] The method for producing a content adhesion preventing lid material according to [11], wherein the solvent is ethanol.

  According to the present invention, in the configuration of the above item [1], hydrophobic fine particles are blended in the content adhesion preventing layer provided in addition to the outer surface of the heat sealing layer. In addition to being able to express the necessary and sufficient content adhesion prevention effect, the adhesion prevention layer contains a thermoplastic resin binder. Complementing the bonding strength between particles and between secondary particles, and at the same time improving their adhesion to the heat-sealing layer, preventing unintentional removal of particles and peeling of the anti-adhesion layer for a long period of time The content adhesion preventing effect can be maintained. In addition, the inclusion of the thermoplastic resin binder in the anti-adhesion layer acts to supplement the heat sealing property of the heat sealing layer, and the container body of the lid material is good and stable regardless of the presence of hydrophobic fine particle groups. It is possible to secure strong heat sealability and sealing performance.

  In the configuration described in the above item [2], the adhesion of the adhesion preventing layer containing hydrophobic fine particles to the base-side heat sealing layer can be kept more reliably and firmly.

  In addition, as described in the above item [3], one or two of vinyl acetate-vinyl chloride copolymer, vinyl acetate-vinyl chloride-maleic acid copolymer, and ethylene-vinyl acetate copolymer are used as a binder. When using a binder consisting of more than one species, particularly when the heat-sealing layer is the most common heat-sealing lid material composed of hot melt, the function and effect of the above-mentioned item [1] is obtained. It can be achieved even better.

  In addition, in the configuration described in the above item [4], an appropriate amount required for the lid material is selected by appropriately selecting the blending ratio of the binder and the hydrophobic fine particles according to the type of food packaged in the container. It is possible to impart an excellent adhesion preventing performance.

  In addition, as described in the above item [5], when the amount of the hydrophobic fine particles to be distributed is relatively larger than that of the binder, it is possible to always impart good content adhesion prevention performance to the adhesion prevention layer.

  In addition, by using hydrophobic fine particles having an average particle size as described in the above item [6], the above-described content adhesion preventing effect can be ensured by using a relatively inexpensive material that is easily available from the market. Can be realized.

  Furthermore, as described in the above item [7], when hydrophobic silica is selectively used for the hydrophobic fine particles, an excellent content adhesion preventing effect is achieved with a relatively inexpensive material that is easily available from the market. can do.

  Moreover, according to the manufacturing method of the content adhesion prevention cover material as described in said [8] item, the cover material which shows the effect by said [1] item can be obtained. In particular, when the coating amount and drying conditions of the coating layer of the coating liquid deviate from the specific range, a good content adhesion preventing effect cannot be exhibited. Alternatively, the productivity of the lid member is lowered and the production cost is increased.

  In the manufacturing method as described in said [9] term, the lid | cover material which has the outstanding effect as described in said [4] term can be obtained.

  As described in the above item [10], by using a solvent having a polar group for the adjustment of the coating liquid, there is little risk of lowering the surface energy of the hydrophobic fine particles, and good adhesion prevention An anti-adhesion layer having performance can be formed.

  Further, when an alcohol solvent is used as described in the above item [11], the corresponding effect in the item [10] can be obtained more reliably.

  Furthermore, as described in the above item [12], when an ethanol solvent is used, the corresponding effect of the item [10] can be achieved more reliably.

FIG. 1 is a cross-sectional view showing an outline of a laminated structure of a content adhesion preventing lid according to the present invention.

  FIG. 1 shows an example of a laminated structure of a content adhesion preventing lid according to the present invention. The lid material includes a base material layer (1) composed of a laminate of a base film layer (2) and a metal foil layer (3), and an outer surface of the base material layer (1) on the metal foil (3) side, A heat sealing layer (5) is provided on the surface facing the inside of the container body when the lid is used via an intermediate resin layer (4). The above laminated structure is the same as that of the conventional lid, and the laminated body including the base material layer (1) and the heat sealing layer (5) will be referred to as a “lid body” here.

  The content adhesion preventing lid material according to the present invention further has an adhesion preventing layer (6) on the outer surface of the heat sealing layer (5) of the lid body.

  The base film layer (2) is disposed on the front side of the packaging container, and the material thereof is a single layer or composite film such as polyester, polyethylene, polypropylene, polyamide, polycarbonate, polyvinyl chloride, cellulose acetate, cellophane, etc. Or what laminated these films on paper etc. can be illustrated. The base film layer (2) is usually appropriately printed (7) to impart design properties.

  The metal foil layer (3) imparts gas barrier properties, light shielding properties, etc., and aluminum foil is often used. In particular, in the case of a lid for a yogurt container, an aluminum foil having a thickness of about 5 to 50 μm is preferably used in order to satisfy light shielding properties and light weight. Moreover, a general adhesive agent is used for lamination | stacking adhesion | attachment with a base film layer (2).

  In addition, as a base material layer (1), it is also possible to use the metal vapor deposition film which vapor-deposited metals, such as a silica and an alumina, to the base film layer (2), without using a metal foil layer (3). .

  The intermediate resin layer (4) is interposed between the base material layer (1) and the heat sealing layer (5), and imparts a predetermined rigidity and cushioning property at the time of heat sealing to the lid material. Provided as needed. Generally, olefin resin such as polyethylene, polypropylene, ethylene (meth) acrylic acid copolymer, ethylene (meth) acrylic acid ester copolymer, polyamide, polyester, polycarbonate, polyvinyl chloride, etc. having a thickness of 5 to 40 μm Used.

  The material of the heat sealing layer (5) is not particularly limited as long as it has good adhesion to the intermediate resin layer (4) and the container side. For example, a hot melt adhesive, a lacquer type adhesive, or a known sealant film can be used. In particular, for a lid for a yogurt packaging container, it is common and preferable to use a hot melt adhesive. The thickness of the heat-sealing layer is not particularly limited, but is generally about 3 to 100 μm in thickness, preferably 10 to 50 μm from the viewpoint of cost, sealing performance, productivity, and the like. It is better to be in the range.

  By the way, the adhesion preventing layer (6) constituting the main component of the present invention comprises a mixed composition of a thermoplastic resin binder and hydrophobic fine particles.

  The material of the thermoplastic resin binder is not particularly limited. However, the thermoplastic resin binder has good compatibility with the heat sealing layer (5) and the hydrophobic fine particles, and exhibits good adhesion to them, and further, the surface layer of the container body. It is desirable to select and use a thermoplastic resin having good adhesiveness, and to use at least the thermoplastic resin as a main component. Examples of such thermoplastic resins include homopolymers such as vinyl acetate resins, polyolefin resins, polyester resins, acrylic resins, styrene resins, or two or more types of copolymers. Since it is a thermoplastic resin, the use of waxes having a low molecular weight, which has been conventionally used as an anti-adhesion agent for lids, is excluded. Particularly preferred binder resins include vinyl acetate-vinyl chloride copolymer, vinyl acetate-vinyl chloride-maleic acid copolymer, and ethylene-vinyl acetate copolymer, one or two of them. The most preferable result can be obtained by using a binder containing at least the above as a main component.

  The hydrophobic fine particles play a dominant role in the content adhesion prevention performance of the lid material, and the material thereof is not particularly limited as long as it is made of a hydrophobic substance having a surface energy of 20 mN / m or more. Specific examples include hydrophobic silica, alumina, calcium oxide, calcium carbonate, calcium sulfate, calcium silicate, and the like. Of these, the use of hydrophobic silica or alumina is preferred from the viewpoint of hydrophobic performance, cost, availability of ultrafine particle materials from the market, and the like.

  The average particle diameter of primary particles of hydrophobic fine particles should be in the range of 1 to 5,000 nm. Ultrafine particles having an average particle size of less than 1 nm are difficult to obtain from the market and are disadvantageous in terms of cost. On the other hand, if the average particle size exceeds 5,000 nm, the heat sealability may be impaired, and the adhesion preventing effect may be reduced, which is not suitable. A preferred average diameter is in the range of 3 to 500 nm, particularly preferably 3 to 100 nm.

  Next, a preferable blending ratio of the thermoplastic resin binder and the hydrophobic fine particles is 10 to 90% by weight: 90 to 10% by weight in a weight ratio of binder (solid content): fine particles. Even if the amount of the hydrophobic fine particles is small, if it is contained in an amount of 10% by weight or more, relatively good adhesion preventing performance can be obtained. The reason for this is not clear, but in the process of forming the anti-adhesion layer as will be described later, the hydrophobic fine particles themselves are in the process of applying and drying the coating liquid in which the hydrophobic fine particles are dispersed in the binder emulsion. It is presumed that the surface density of the coating layer tends to shift to the surface side due to the influence of the relatively large surface energy, and the distribution density becomes higher in the surface portion. Even when the adhesion preventing layer is formed thin, if the blending amount of the hydrophobic fine particles is less than 10% by weight, the intended content adhesion preventing performance is insufficient. On the other hand, if the amount exceeds 90% by weight, the adhesiveness (adhesiveness) to the heat-sealing layer becomes insufficient, and the fine powder itself or the adhesion preventing layer is partially dropped or peeled off easily. It will be a thing. In order to ensure sufficient adhesion prevention performance and sufficient and sufficient adhesion, the amount of hydrophobic fine particles should be set to 40% by weight or more, particularly preferably the hydrophobic fine particles are resin. It should be set in the range of 50 to 80% by weight as containing more than the binder.

  In the production of the anti-adhesion lid according to the present invention, the method for forming the anti-adhesion layer (6) also has a significant influence on the content adhesion prevention performance of the lid.

  The anti-adhesion layer (6) is formed by uniformly dispersing a predetermined amount of hydrophobic fine particles in an emulsion or solution of a thermoplastic resin binder to prepare a coating solution, which is applied to the outer surface of the heat sealing layer of the lid body. And drying.

  In adjusting the coating liquid, water or an organic solvent can be used as a solvent for dissolving the binder, but it is particularly preferable to use an organic solvent having a polar group. Of these, the use of alcohols is preferred, and the use of ethanol is particularly preferred from the standpoints of cost, safety, water repellency and the like. It has been found that when a solvent having no polar group, such as toluene, is used, the anti-adhesion performance is impaired. Although the mechanism is still unclear, it is presumed that the wax in the heat-sealing layer is partially dissolved by toluene and the adhesiveness with the hydrophobic silica particles becomes too high.

  Any known method can be employed for coating the coating liquid. For example, a gravure coating method, spraying, a bar coating method, etc. can be arbitrarily adopted.

The coating amount of the coating solution may be set according to the thickness of the adhesion preventing layer, but is preferably about 0.1 to 5.0 g / m ^{2 by} weight after drying, and 0.3 to 1.0 g / m. ² is more preferable, and it is optimal to set it in the range of 0.5 to 0.8 g / m ² . If it is less than 0.1 g / m ² , the content adhesion preventing effect may be insufficient. On the other hand, if it exceeds 5.0 g / m ² , the cost is increased, and it is necessary to increase the binder component in order not to lower the heat sealability. In that case, the content adhesion preventing effect may not be sufficiently obtained. When the amount of the binder component is small, the content adhesion preventing layer may drop off, which is not preferable.

  The drying process after application is also an important factor. Naturally, it may be naturally dried, but in order to improve productivity and adhesion to the heat sealing layer, it should be dried by heating. In this case, the drying conditions are a temperature of 80 to 140 ° C., a time of 5 to 30 seconds. Should be set in the range. If the temperature is lower than the lower limit of 80 ° C., the drying process takes time, and if the time is less than 5 seconds, the drying becomes insufficient, and the adhesion preventing layer is likely to be partially peeled off or dropped during subsequent handling. On the other hand, when the drying temperature is set to a high temperature exceeding 140 ° C., or the time is set to a time exceeding 30 seconds, especially when hydrophobic silica is used for the hydrophobic fine particles, the hydrophobicity and repellent properties of the hydrophobic fine particles are increased. It has been confirmed that the aqueous properties are impaired. Incidentally, the mechanism of the hydrophobicity decrease due to the heat effect has not yet been elucidated.

  Next, in order to confirm the effect of the present invention, various examples will be shown in comparison with comparative examples.

(Preparation of lid body)
A polyethylene terephthalate film having a thickness of 12 μm was used as the substrate film (2), and an aluminum foil (3) having a thickness of 30 μm was bonded to one surface thereof with a polyurethane-based dry laminate adhesive to obtain a substrate layer (1).

  Next, an intermediate resin layer (4) is formed by laminating and bonding a 20 μm thick polyethylene film to the surface of the base material layer (1) on the aluminum foil (3) side using the same adhesive as described above. A heat sealing layer (5) was formed on the outside by a gravure coating method. The laminate of the base material layer (1) / intermediate resin layer (4) / heat sealing layer (5) obtained in this way was used as the lid body.

  Here, as the heat sealing layer (5), the following three types were prepared.

・ Hot melt type: Wax: 40 parts by weight, Rosin: 5 parts by weight, Silicon oil: 1
A hot melt agent having a composition consisting of parts by weight of ethylene-vinyl acetate copolymer: the rest was applied by a gravure coating method at a coating amount of 18 g / m ² to form a hot melt heat sealing layer.

  ・ Sealant film type: A 30μm thick sealant film consisting of an easy peel film of the main component polyethylene is laminated by extrusion lamination through a urethane adhesive layer to form a sealant film type heat sealing layer. Formed.

・ Lacquer type: As a suitable material for lids of polystyrene containers, heat seal lacquer composed of main component acrylic resin and polyester resin is applied by gravure coating method at a rate of 5 g / m ² , and lacquer type A heat sealing layer was formed.

(Formation of adhesion prevention layer)
The following binder and hydrophobic fine particles were prepared as materials for the adhesion preventing layer.

Binder A: Ethylene-vinyl acetate copolymer (20% vinyl acetate, 80% ethylene)
B: Vinyl acetate-vinyl chloride copolymer (20% vinyl acetate, 80% vinyl chloride)
C: Vinyl acetate-vinyl chloride-maleic acid copolymer (20% vinyl acetate, 78% vinyl chloride, 2% maleic acid)
D: B + C mixture (B80%, C20%)
E: Polyethylene (density 0.900 g / cm ³ , MFR ³ g / 10 min)
F: Ethylene-methacrylic acid copolymer (methacrylic acid content 10% by weight)

Hydrophobic fine particles P1: Hydrophobic silica Primary particle average particle size 7 nm
P2: Hydrophobic silica Primary particle average particle size 3 nm
P3: Hydrophobic silica Primary particle average particle diameter 100 nm
P4: Hydrophobic silica Primary particle average particle size 500 nm
P5: Alumina primary particle average particle size 100 nm

  Hydrophobic fine particles were mixed in various blending ratios shown in Table 1 in an emulsion or solution obtained by diluting the above various binders with ethanol, and uniformly dispersed to prepare a coating solution.

  Then, these various coating liquids are applied to the outer surface of the heat sealing layer of the lid body by a gravure coating method with various coating amounts and drying conditions as shown in Table 1, and then forcedly dried and adhered. A prevention layer was formed.

(Type of preparation sample)
Among samples 1 to 29 of the various lid materials shown in Table 1 obtained as described above, samples 1 to 15 were obtained by investigating the influence by changing the mixing ratio and application amount of the hydrophobic fine particles and the binder in the adhesion preventing layer. It is.

  Samples 16 and 17 were obtained by examining the influence of different types of heat sealing layers (hot melt, sealant film, lacquer) in the lid body.

  Samples 18 to 21 are obtained by using hydrophobic silica and alumina having different average particle diameters as hydrophobic fine particles.

  Samples 22 to 26 were prepared by changing the type of binder used for the adhesion preventing layer to other types of binders other than EVA.

  In Samples 27 to 29, in relation to the method of manufacturing the lid material, the influence of changing the coating amount and drying conditions of the coating liquid for forming the adhesion preventing layer was examined.

(Evaluation test)
(1) Anti-adhesion performance Each sample No. Aloe yogurt (Trademark “Morinaga Aloe Yogurt” manufactured by Morinaga Milk Industry Co., Ltd.) is dropped as a 0.5 cc droplet on the back of the lid material 1 to 29, that is, on the outer surface of the adhesion preventing layer, and the sample is slowly tilted. When the above-mentioned droplet was measured, the “inclination angle when it started to roll” was measured and evaluated according to the following criteria.
◎ ・ ・ ・ 30 degrees or less ○ ・ ・ ・ 31 degrees or more and 60 degrees or less △ ・ ・ ・ 61 degrees or more and 90 degrees or less × ・ ・ ・ 90 degrees or more

(2) Sealability Sample No. 1 to 29 of the lid body (paper / polyethylene container, but polystyrene container for the lid of sample No. 15) under the hot-pressure sealing condition of 120 to 180 ° C. × 0.2 MPa × 1.0 sec. Heat sealed on the flange surface.
Then, the seal strength (peeling resistance / sealing strength of the lid material) in the lid material as it is without the adhesion preventing layer was used as a reference value, and the rate of decrease in the seal strength was judged and evaluated according to the following criteria.
◎ ・ ・ ・ Approximately equivalent to those without adhesion prevention layer ○ ・ ・ ・ Strength reduction less than 10% △ ・ ・ ・ Strength reduction 10% to less than 20% × ・ ・ ・ Strength reduction 20% or more

(3) Adhesion Sample No. A weight (500 g) wrapped with a black cloth was placed vertically on the surface of the adhesion preventing layer of each of the lid materials 1 to 29, and slowly rubbed by a length of 200 mm, and the silica adhering to the cloth was visually confirmed.
And the transfer adhesion amount (peeling amount) of the hydrophobic fine particles and the adhesion preventing layer in the black cloth was visually inspected and evaluated according to the following evaluation criteria.
◎ ・ ・ ・ No adhesion ○ ・ ・ ・ Slight adhesion recognized as an acceptable range × ・ ・ ・ Clearly much adhesion Table 2 shows the results of the evaluation tests (1) to (3) above. .

  As shown in the results of the “anti-adhesion performance” test in Table 2, in the contents anti-adhesion lid material according to the present invention, the yogurt droplet starts rolling and moving only by slightly tilting the sample. This indicates that the contents containing viscous liquid components such as yogurt, pudding, and jelly are excellent in the effect of preventing the contents from adhering to the back surface of the lid. In addition, as shown in the results of the “sealability” test, the above adhesion prevention performance can be imparted while maintaining good sealing performance without significantly impairing the heat sealability (seal strength) due to the presence of the adhesion prevention layer. In addition, as seen in the results of the “adhesion” test, the adhesion of the hydrophobic particles and the anti-adhesion layer containing them is good, and unintentional separation of hydrophobic fine particles, partial peeling of the anti-adhesion layer, etc. There is no fear of contamination, the content adhesion prevention performance can be stably maintained over a long period of time, and there is no possibility of foreign matter mixing into the container.

Claims (12)

In a lid having at least a base material layer and a heat sealing layer,
An adhesion preventing layer on the outer surface of the heat sealing layer;
The anti-adhesion layer is composed of a mixed composition of a thermoplastic resin binder and hydrophobic fine particles, and the content anti-adhesion cover material.   2. The content adhesion preventing lid material according to claim 1, wherein the thermoplastic resin binder contains a synthetic resin having adhesiveness to both the heat sealing layer and the hydrophobic fine particles as a main component.   The thermoplastic resin binder comprises one or more of vinyl acetate-vinyl chloride copolymer, vinyl acetate-vinyl chloride-maleic acid copolymer, and ethylene-vinyl acetate copolymer. The content adhesion prevention lid material according to claim 1 or 2.   The blending ratio of the thermoplastic resin binder and the hydrophobic fine particles in the mixed composition is 10 to 90% by weight of the binder and 90 to 10% by weight of the hydrophobic fine particles in a solid content ratio. The content adhesion prevention cover material of description.   The said mixed composition is a content adhesion prevention lid | cover material of any one of Claims 1-4 which contains relatively many hydrophobic fine particles rather than the said thermoplastic resin binder.   The content adhesion prevention lid material according to any one of claims 1 to 5, wherein the hydrophobic fine particles have an average particle diameter of 1 nm to 5,000 nm.   The content adhesion prevention lid material according to any one of claims 1 to 6, wherein the hydrophobic fine particles are hydrophobic silica. A coating solution prepared by dispersing hydrophobic fine particles in an emulsion or a solution of a thermoplastic resin binder on the outer surface of the heat sealing layer of a lid member having at least a base material layer and a heat sealing layer is dried to a weight of 0.00. A content adhesion prevention lid characterized by forming an adhesion prevention layer by coating at 1 to 5.0 g / m ² and then drying under drying conditions of a temperature of 80 to 140 ° C. and a time of 5 to 30 seconds. A method of manufacturing the material.   9. The thermoplastic resin binder comprises one or more of vinyl acetate-vinyl chloride copolymer, vinyl acetate-vinyl chloride-maleic acid copolymer, and ethylene-vinyl acetate copolymer. The manufacturing method of the content adhesion prevention lid | cover material as described in 1 ..   The method for manufacturing a content adhesion preventing lid material according to claim 8 or 9, wherein the coating liquid uses a solvent having a polar group.   The method for producing a content adhesion preventing lid material according to claim 10, wherein the solvent is alcohol.   The method for producing a content adhesion preventing lid material according to claim 11, wherein the solvent is ethanol.

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