JP2017222413A - Lid material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lid material in which a base material 1, anchor coat layer 2, heat seal layer 3 and adherence preventive layer 4 preventing adherence of a content are laminated in this order; the anchor coat layer contains particles 2a; and an adherence preventive performance is further improved as premises for the lid material in which the adherence preventive layer contains the hydrophobic fine particles 4b having the particle size of 1.0 μm or less.SOLUTION: An objective lid material is characterized in that in addition to hydrophobic fine particles 4b, the large particles 4a in an adherence preventive layer having the particle size of 10-4,000 times of the hydrophobic fine particle are blended into the adherence preventive layer to be less than 50 mass to the total amount of the hydrophobic particle and the large particle in the adherence preventive layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lid member. In particular, lids for packaging foods, beverages, pharmaceuticals, cosmetics, chemicals, etc. More specifically, lids for containers such as yogurt, jelly, pudding, syrup, retort foods such as porridge and soup, and chemicals The present invention relates to a lid used for a storage container for liquids such as goods and pharmaceuticals, semi-solids, and gel substances.

  Ordinary lids are difficult to remove due to adhesion of the contents, and often cause waste or dirt of the contents. In addition, when a fluorine material or silicone is used, although it has water repellency and adhesion prevention effects, it has poor heat sealing properties and is difficult to use as a lid material.

  In order to solve these problems, a cover material is formed by laminating a base material, an anchor coat layer, a heat seal layer, and an adhesion preventing layer for preventing the adhesion of contents in this order, and the anchor coat layer contains particles. In addition, a lid material is proposed in which the adhesion preventing layer contains hydrophobic fine particles having a particle diameter of 1.0 μm or less, and irregularities based on the particles of the anchor coat layer are formed on the surface of the adhesion preventing layer ( Patent Document 1). This lid material is placed in the container opening and heated and pressurized, whereby the adhesion preventing layer is buried in the heat seal layer and heat sealed to the flange around the container opening.

JP2015-131658A

  However, even the lid material of Patent Document 1 is not sufficient in performance to prevent adhesion of contents.

  Then, this invention aims at providing the cover material which further improved the adhesion prevention performance on the assumption of the cover material of patent document 1. FIG.

That is, the invention described in claim 1 is a lid member formed by laminating a base material, an anchor coat layer, a heat seal layer, and an adhesion preventing layer for preventing adhesion of contents in this order, and the anchor coat layer is It is composed of a composition in which particles having an average particle size of 1 to 100 μm (particles in the anchor coat layer) are dispersed in a binder, and the adhesion preventing layer contains hydrophobic fine particles having a particle size of 1 to 100 nm. In the lid material in which irregularities based on the particles in the anchor coat layer are formed on the surface of the adhesion preventing layer,
In addition to the hydrophobic fine particles, large particles (large particles in the anti-adhesion layer) having a particle size 10 to 4000 times that of the hydrophobic fine particles are contained in the anti-adhesion layer, and The lid material is characterized in that the blending amount of the large particles is less than 50 mass with respect to the total amount of the hydrophobic fine particles and the large particles in the adhesion preventing layer.

  Next, the invention according to claim 2 is the lid according to claim 1, wherein the particle size of the large particles in the adhesion preventing layer is smaller than the particle size of the particles in the anchor coat layer.

The invention according to claim 3 is the lid material according to claim 1 or 2, wherein the large particles in the adhesion preventing layer are inorganic oxide particles surface-treated with a hydrophobic functional group.

  The invention according to claim 4 is the lid according to claim 3, wherein the surface treatment is a treatment with a silane coupling agent or a silylating agent.

  In addition, the invention according to claim 5 is characterized in that the adhesion preventing layer contains a binder for fixing these particles in addition to the hydrophobic fine particles and the large particles in the adhesion preventing layer. It is a lid | cover material in any one of claim | item 1 -4.

  The invention described in claim 6 is characterized in that the binder of the adhesion preventing layer is a resin selected from a polyester resin, an acrylic resin, a polyurethane resin, an epoxy resin, a melamine resin, a phenol resin, and a silicone resin. The lid material according to claim 5.

  The invention according to claim 7 is the lid according to any one of claims 1 to 6, wherein the material of the particles in the anchor coat layer is a metal oxide or a resin.

  In the lid material of the present invention, the anchor coat layer contains particles in the anchor coat layer having an average particle diameter of 1 to 100 μm, and irregularities based on the particles in the anchor coat layer are formed on the surface of the adhesion preventing layer. The anti-adhesion layer also contains both the large particles in the anti-adhesion layer and hydrophobic fine particles, so that the surface of the anti-adhesion layer is formed with unevenness caused by these three types of particles in a superimposed manner. . For this reason, the surface of the adhesion preventing layer has extremely complicated irregularities having a high fractal dimension. And since the particle | grains with the smallest particle diameter have hydrophobicity among these three types of particle | grains, the adhesion prevention performance with respect to contents, such as yogurt, increases.

It is sectional explanatory drawing of the cover material which concerns on the specific example of this invention. 6 is a cross-sectional explanatory view of a lid member according to Comparative Example 1. FIG. 10 is a cross-sectional explanatory view of a lid member according to Comparative Example 2. FIG.

  The present invention is a lid material that heat-releasably adheres to an opening of a container such as a cup container, seals the opening, and prevents the contents from adhering to the opening. In addition, a heat seal layer thermally bonded to the opening of the container and an adhesion preventing layer are laminated in this order via an anchor coat layer. FIG. 1 of the drawings shows a cross section thereof.

  The anchor coat layer 2 contains particles 2a therein, and has irregularities based on the particles 2a on the surface. The heat seal layer 3 and the adhesion preventing layer 4 are both provided along the uneven surface. Therefore, the unevenness on the surface of the anchor coat layer 2 is reflected on the surface of the heat seal layer 3. Moreover, it is reflected also on the surface of the adhesion preventing layer 4. That is, irregularities based on the particles 2a of the anchor coat layer 2 are formed on the surface of the adhesion preventing layer 4, in other words, on the surface of the lid member. In order to distinguish from particles 4a and 4b in the adhesion preventing layer 4 described later, the particles 2a of the anchor coat layer 2 are hereinafter referred to as “anchor coat layer particles”.

  The adhesion preventing layer 4 contains two kinds of particles 4 a and 4 b inside, and irregularities based on these two kinds of particles 4 a and 4 b are formed on the surface of the adhesion preventing layer 4. For this reason, on the surface of the adhesion preventing layer 4, the unevenness based on the anchor coat layer inner particles 2 a and the unevenness based on these two kinds of particles are formed so as to overlap each other.

  Of the two types of particles 4a and 4b included in the adhesion preventing layer 4, particles having a small particle diameter are fine particles 4b having a particle diameter of 1 to 100 nm and a hydrophobic surface. The other particle is a particle 4a having a larger particle diameter than the hydrophobic fine particles 4b. The particles 4a are referred to as “large particles in the anti-adhesion layer” in order to distinguish them from both the anchor coat layer inner particles 2a and the hydrophobic fine particles 4b. The large particles 4a in the adhesion preventing layer need to have a particle diameter 10 to 4000 times that of the hydrophobic fine particles 4b. The large particles 4a in the anti-adhesion layer desirably have a smaller particle size than the particles 2a in the anchor coat layer. In this way, when the large particles 4a in the anti-adhesion layer are smaller than the particles 2a in the anchor coat layer, the three types of particles 2a, 4a and 4b have different particle diameters. Concavities and convexities of three sizes, large and small, are formed to overlap. Therefore, the surface has a complex uneven shape with a high fractal dimension regardless of the definition of the fractal dimension.

  The hydrophobic fine particle 4a has a function of preventing the adhesion of contents based on its own surface hydrophobicity. However, in the lid material of the present invention, the surface of the adhesion preventing layer 4 has a complicated uneven shape as described above. Therefore, the adhesion prevention property increases.

  Hereinafter, the material of the base material 1 and each layer and the method of forming the layer will be sequentially described.

  The substrate 1 according to the present invention may be an arbitrary sheet. It may be composed of a single sheet or a sheet having a multilayer structure. For example, paper, polyethylene terephthalate, polyethylene, polypropylene, polyamide, polycarbonate, polyvinyl chloride, cellulose acetate, cellophane, aluminum foil and the like can be used. Moreover, what laminated | stacked these may be used.

  Moreover, the base material 1 may contain the vapor deposition film which provided the thin film of the metal or the metal oxide in the layer structure. Examples of the metal include silicon and aluminum. Examples of the metal oxide include silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, and magnesium oxide. In addition, as a deposition base material for forming these thin films, polyethylene terephthalate, polyethylene, polypropylene, polyamide, polycarbonate, polyvinyl chloride, cellulose acetate, cellophane, and the like can be used. And these thin films can be provided on a vapor deposition base material by vacuum processes, such as a vacuum evaporation method, sputtering method, and a plasma vapor deposition method.

  Next, the anchor coat layer 2 needs to be composed of a composition in which the particles 2a in the anchor coat layer are dispersed. For example, a composition in which the curable resin is used as a binder and the anchor coat layer inner particles 2a are dispersed in the binder. As the curable resin, acrylic curable resin, urethane curable resin, epoxy curable resin, melamine curable resin, phenol curable resin, silicone curable resin, polyester curable resin, etc. are used. it can. It may be a one-component curable resin or a two-component curable resin. Desirably, it is a two-component curable polyester-based curable resin.

  As described above, the surface of the anchor coat layer 2 has irregularities based on the particles 2a in the anchor coat layer, and these irregularities are also reflected on the surface of the adhesion preventing layer 4, that is, the surface of the lid. Yes. In order to exert a sufficient adhesion preventing effect, the surface of the lid material needs to have a 10-point average roughness of 5 μm or more. Therefore, the particle diameter of the anchor coat layer inner particles 2a should be large enough to realize this. Must have. For these reasons, the average particle diameter of the anchor coat layer inner particles 2a needs to be 1 to 100 μm. When the average particle diameter of the anchor coat layer inner particles 2a is smaller than 1 μm, the unevenness on the surface of the lid material becomes small, and a sufficient adhesion preventing effect cannot be exhibited. On the other hand, if it is larger than 100 μm, it is difficult to form high-density irregularities, and a sufficient adhesion preventing effect cannot be exhibited. In addition, particles having a large particle size are difficult to be fixed by the binder and easily fall off due to external stress such as friction. Desirably, the average particle size is 10 to 50 μm.

  Further, the anchor coat layer inner particles 2a may be made of any material, but for example, silicone particles or metal oxide particles such as alumina and titania can be preferably used. Further, as the anchor coat layer inner particles 2a, particles made of a synthetic resin can be used. For example, synthetic resins such as polyethylene resin, polystyrene resin, polypropylene resin, polyamide resin, polyester resin, acrylic resin, and fluororesin. The shape of the anchor coat layer inner particles 2a may be arbitrary, but spherical particles can be preferably used.

  As described above, the compounding ratio of the anchor coat agent 2b and the anchor coat layer inner particles 2a is such that irregularities based on the anchor coat layer inner particles 2a are formed on the surface of the obtained anchor coat layer 2, and the anchor coat layer 2 What is necessary is just to determine so that the particle | grains 2a may adhere firmly and may not fall off. Desirably, the blending ratio is determined so that the ten-point average roughness Rz of the surface is 5 μm or more.

  Moreover, as a coating method of this anchor coat layer 2, for example, roll coating, gravure coating, bar coating, kiss reverse coating, die coating, doctor blade coating, brush coating, dip coating, spray coating and the like can be used.

  Next, as a material of the heat seal layer 3, depending on the material of the container, polyethylene resin, polyacrylate resin, ethylene-vinyl acetate copolymer resin, ionomer resin, polyvinyl acetate resin, polypropylene resin, polyvinyl chloride resin, A heat-sealable resin such as a hot melt resin can be used. Moreover, it is also possible to use the resin composition which has these heat sealable resin as a main component and mix | blended vinyl chloride-vinyl acetate copolymer resin with this.

  For example, when the material of the container is polyethylene or polystyrene, generally a resin selected from an ethylene-based resin, a polyacrylate resin, an ethylene-vinyl acetate copolymer resin, and a modified polyolefin resin is used as the heat sealable resin. Can do.

  When the material of the container is polypropylene, a resin selected from polyacrylate resin, ethylene-vinyl acetate copolymer resin, and modified polyolefin resin can be generally used as the heat-sealable resin.

  In addition, as a modified polyolefin resin, what was obtained by acid-modifying polyethylene or a polypropylene is desirable. Among them, a resin obtained by modifying polyethylene or polypropylene with an unsaturated carboxylic acid or an anhydride thereof is preferable.

  In addition, when the vinyl chloride-vinyl acetate copolymer resin is blended and used in these heat sealable resins, the blending amount of the vinyl chloride-vinyl acetate copolymer resin is 10 to 30% by mass of the heat seal layer 3. It is desirable to occupy. When the heat seal layer 3 is composed of a heat-sealable resin blended with vinyl chloride-vinyl acetate copolymer resin, the lid material of the present invention is heat-sealed at the container opening, and then the lid material is peeled off from the container. At this time, since the heat seal layer 3 cohesively breaks, the peeling opening becomes easy and the lid member is not damaged.

The heat seal layer 3 is formed by coating using a coating method such as roll coating, gravure coating, bar coating, kiss reverse coating, die coating, doctor blade coating, brush coating, dip coating, spray coating or spray coating. Can do. The heat seal layer 3 may be applied to the entire surface by covering the anchor coat layer 2.

  It is also possible to form the heat seal layer 3 by extrusion coating of a melted heat sealable resin.

  The anti-adhesion layer 4 is obtained by fixing hydrophobic fine particles 4b having an average particle diameter of 5 to 1000 nm and large particles 4a in the anti-adhesion layer having a particle size 10 to 4000 times that of the hydrophobic fine particles 4b with a binder 4c. The uneven surface and the hydrophobic surface of the hydrophobic fine particles 4a prevent adhesion of the contents. For this reason, the adhesion prevention layer 4 needs to be arrange | positioned so that it may be exposed to the outermost surface of a cover material. In addition, since the lid material is thermally bonded to the container by the heat seal layer 3, the adhesion preventing layer 4 needs to be disposed directly on the heat seal layer 3 without any other layer. There is. In this case, the adhesion preventing layer 4 can be buried in the heat seal layer 3 and thermally bonded by disposing the lid material of the present invention in the container opening and applying heat and pressure.

  The anti-adhesion layer 4 is such that the hydrophobic fine particles 4b do not sink into the binder 4c and are not buried, and a part of the hydrophobic fine particles 4b is exposed on the surface, and minute irregularities based on the hydrophobic fine particles 4b. It is desirable to constitute the surface. For example, 30% or more of the surface area of the adhesion preventing layer 4 is covered with the hydrophobic fine particles 4b. If the coating area is smaller than this, sufficient adhesion preventing effect cannot be exhibited. Preferably, 70% or more of the surface area of the adhesion preventing layer 4 is covered with the hydrophobic fine particles 4b.

  As such hydrophobic fine particles 4b, for example, inorganic oxide particles surface-treated with a hydrophobic functional group can be preferably used. As the inorganic oxide particles serving as the core, silicon oxide, aluminum oxide, titanium oxide, magnesium oxide, or the like can be used. As these inorganic oxide particles, those produced by a dry method (for example, a combustion method, an arc method, etc.) or a wet method (for example, a precipitation method, a gel method, etc.) can be used.

  Examples of the surface treatment with a hydrophobic functional group include a treatment with a silane coupling agent and a treatment with a silylating agent. In this case, a hydrophobic functional group is added to the surface of the core inorganic oxide particles. It can be applied to make the surface hydrophobic. This treatment may be performed by either a dry method or a wet method. Desirably, a dry method such as a CVD method or a plasma method is used.

As the silane coupling agent, a dimethylsilyl silane coupling agent (chemical formula: (CH ₃ ) ₂ Si (O—R) ₂ ), a trimethylsilyl silane coupling agent (chemical formula: (CH ₃ ) ₃ SiO—R), dimethylpolysiloxane-based silane coupling agent (chemical _{formula: Si (CH 3) 3 -O-} [Si (CH 3) 2] n -O-Si (O-R) 3), aminoalkyl silyl silane coupling agent, Alkylsilyl silane coupling agents, methacrylsilyl silane coupling agents, and the like are preferable, and trimethylsilylsilane coupling agents having a large number of methyl groups (chemical formula: CH ₃ ) are more preferable. In the chemical formula, “O—R” represents a substituent to be hydrolyzed.

Moreover, a fluorine-type silane coupling agent can also be used as a silane coupling agent. As the fluorine-based silane coupling agent, a silane coupling agent having a fluoroalkyl group (CF ₃ (CF ₂ ) n—) as a hydrophobic group can be used. For example, trifluoropropyltrialkoxysilane, heptadecafluorodecyltrialkoxysilane, and the like.

As silylating agents, chlorotrimethylsilane, chlorotriethylsilane, trimethylsilylimidazole, hexamethyldisiloxane, N, N-dimethyltrimethylsilylamine, chlorotriisopropylsilyl, 1,3-dimethyl-1,1,3,3 -Tetraphenyldisilazane and the like can be exemplified.

  Also, fluororesin fine particles can be used as the hydrophobic fine particles 4b. Fluorine resin fine particles include polytetrafluoroethylene, polychlorotrifluoroethylene, polyhexafluoropropylene, tetrafluoroethylene-hexafluoropropylene copolymer, polyvinyl fluoride, polyvinylidene fluoride, perfluoroalkoxy resin, etc. Can be illustrated. For example, polytetrafluoroethylene marketed as a dry powder.

  The hydrophobic fine particles 4b are preferably contained in the adhesion preventing layer 4 in an amount of 5 to 95% by mass. If the amount of the hydrophobic fine particles 4b is less than this, a sufficient adhesion preventing effect cannot be exhibited. On the other hand, when the amount is larger than this, the hydrophobic fine particles 4b are likely to be lost, and the adhesion preventing effect may be reduced due to the loss.

  Next, the large particles 4a in the anti-adhesion layer supplement the irregularities on the surface of the anti-adhesion layer 4 so that the surface has a complex irregular shape. For this reason, the large particles 4a in the adhesion preventing layer have a particle size larger than that of the hydrophobic fine particles, and need to have a particle size 10 to 4000 times that of the hydrophobic fine particles. Further, since the anchor coat layer inner particles 2a form large irregularities on the surface of the adhesion preventing layer 4, it is desirable that the particle diameter of the anchor coat layer inner particles 2a is smaller. When the particle size 4a in the adhesion preventing layer is larger than that of the hydrophobic fine particle 4b and smaller than the particle size 2a in the anchor coat layer, the large particle 4a in the adhesion preventing layer causes the hydrophobic particle 4b. An unevenness having a size intermediate between the fine unevenness and the large unevenness due to the particles 2a in the anchor coat layer can be provided on the surface of the adhesion preventing layer 4.

  The material of the large particles 4a in the adhesion preventing layer may be the same as the material of the hydrophobic fine particles 4b. That is, it is an inorganic oxide particle surface-treated with a hydrophobic functional group. Silicon oxide, aluminum oxide, titanium oxide, or the like can be used as the inorganic oxide particles serving as the core, and examples of the surface treatment include treatment with a silane coupling agent and treatment with a silylating agent.

  In addition, the compounding quantity of the adhesion prevention layer large particle 4a needs to be less than 50 mass with respect to the total amount of the hydrophobic fine particle 4b and the adhesion prevention layer large particle 4a. As can be seen from Comparative Examples 3 and 4 to be described later, if the amount of the large particles 4a in the adhesion preventing layer exceeds this, the surface hydrophobicity of the hydrophobic fine particles 4b cannot be utilized, and the adhesion preventing performance is deteriorated. .

  Next, as the binder 4c for fixing the particles 4a and 4b, a cured product of a metal alkoxide can be preferably used. Moreover, the hardened | cured material which mixed and hardened the silane coupling agent in the metal alkoxide can also be utilized.

The metal alkoxide is a compound represented by the general formula M (OR) _n (M is a metal atom such as Si, Ti, Al, Zr, R is an alkyl group such as CH ₃ or C ₂ H ₅ , and n is an integer). Of these, metal alkoxides in which the metal element M is any one of Si, Ti, and Al are preferable. For example, tetraethylorthosilicate (Si (OC ₂ H ₅ ) ₄ ), triisopropylaluminum (Al (OC ₃ H ₇ ) _3, etc. The silane coupling agent includes a vinyl group, an epoxy group as a functional group. , A styryl group, a methacryl group, an acrylic group, an amino group, a ureido group, a mercapto group, a sulfide group, an isocyanate group, and the like.

The adhesion preventing layer 4 is prepared by mixing a material of these binders 4c, for example, a metal alkoxide or a mixture of a metal alkoxide and a silane coupling agent, the adhesion preventing layer inner large particles 4a and the hydrophobic fine particles 4b, to form a heat seal layer. It can be formed by coating on 3, drying by heating and curing the metal alkoxide.

  The film thickness of the adhesion preventing layer 4 is preferably in the range of 0.1 to 10 μm. If it is thinner than this, the amount of the hydrophobic fine particles 4b decreases, and a sufficient adhesion preventing effect cannot be exhibited. On the other hand, if it is thicker than this, the unevenness based on the particles 2a in the anchor coat layer becomes small, so that sufficient adhesion prevention effect cannot be exerted, and seal inhibition occurs when thermally bonding to the container flange, so that sufficient sealing cannot be achieved. .

  Examples of the coating method that can be used include roll coating, direct gravure coating, reverse gravure coating, bar coating, kiss reverse coating, die coating, doctor blade coating, brush coating, dip coating, and spray coating.

  As described above, the lid member of the present invention can be used as a lid member that is thermally bonded to the flange of a container containing the contents. Any container may be used as long as it has a flange. For example, a cup-shaped container or a tray-shaped container can be used. As the contents, gel-like contents such as yogurt that easily adhere to the lid are suitable, but not limited to this, retort food such as jelly, pudding, syrup, rice cake, soup, or chemicals and pharmaceuticals. Etc. can be accommodated. Further, it may be a container for any purpose such as a chilled container, an aseptic container, a retort container, and the like. And after thermally bonding the lid material of the present invention to the flanges of these containers, when peeling the lid material and opening the container, the lid material is not damaged and the contents adhere to the lid material. The lid can be peeled off and opened.

Example 1
As the substrate 1, a laminate of a polyester film having an aluminum vapor deposition layer and paper was used. In addition, this polyester film and paper were bonded together by the dry lamination method.

A solution of a two-component curable polyester resin (manufactured by DIC: A970) was used as the binder 2b of the anchor coat layer 2, and acrylic particles (average particle size 20 μm) were used as the particles 2a in the anchor coat layer. Then, the anchor coat layer inner particles 2a are dispersed in the binder solution to prepare a coating liquid having a solid content of 30% by mass (binder 15% by mass, anchor coat layer inner particle 15% by mass). The anchor coat layer 2 was formed by coating and drying on the surface of the polyester film 1. The application method is gravure coating, and the wet application amount is 4.0 g / m ² . On the surface of the formed anchor coat layer 2, irregularities based on the anchor coat layer inner particles 2a were formed.

  Next, an acrylic heat seal resin (manufactured by DIC: A450) was used as the heat seal layer 3. And this heat seal resin was apply | coated and dried on the anchor coat layer 2, and the heat seal layer 3 was formed. The application method is gravure coating.

Next, hydrophobic silica fine particles (manufactured by Fuji Silysia: Silo Hovic 200, average primary particle size 4 μm) were used as the large particles 4a in the adhesion preventing layer, and a particle dispersion liquid in which this was dispersed in methanol was prepared. On the other hand, silica fine particles (manufactured by Nippon Aerosil Co., Ltd .: RY200S, average primary particle size 16 nm) surface-treated with a dimethylsiloxane-based silane coupling agent by a dry method were used as the hydrophobic fine particles 4b, which were dispersed in methanol. A particle dispersion was prepared. Then, both particle dispersions were mixed to produce a mixed particle dispersion. The blending ratio of both particle dispersions is such that the large particles 4a in the anti-adhesion layer account for 20% by mass and the hydrophobic fine particles 4b account for 80% by mass with respect to the total amount of both particles 4a, 4b.

  Further, as a material for the binder 4c of the adhesion preventing layer 4, tetraethoxysilane (TEOS) was mixed with hydrochloric acid to hydrolyze tetraethoxysilane (TEOS) to prepare a silica sol.

And these mixed particle dispersion liquids and the binder 4c were mixed so that solid content weight ratio might be the ratio of 1: 2, and diluted so that it might become solid content 10 mass%, and the coating liquid was prepared. And this adhesion | attachment layer 4 was formed by apply | coating this coating liquid on the heat seal layer 3, and heating and drying-curing it, and it was set as the cover material of Example 1. FIG. The application method is gravure coating, and the wet application amount is 1.5 g / m ² . The surface of the formed anti-adhesion layer 4 reflects large irregularities based on the anchor coat layer inner particles 2a, and is based on the fine irregularities based on the hydrophobic fine particles 4b and the large anti-adhesion layer particles 4a. Since unevenness of an intermediate size is formed and these three types of large and small unevenness are overlapped, a complicated uneven surface is formed.

(Example 2)
A lid material was produced in the same manner as in Example 1 except that the type, particle diameter, and blending ratio of the large particles 4a and hydrophobic fine particles 4b in the adhesion preventing layer 4 included in the adhesion preventing layer 4 were different from those in Example 1.

  That is, first, the anchor coat layer 2 and the heat seal layer 3 were formed on the substrate 1 in the same manner as in Example 1.

  As the large particles 4a in the adhesion preventing layer, hydrophobic silica fine particles (manufactured by Fuji Silysia Co., Ltd .: Silo Hovic 100, average primary particle size 3 μm) were used, and a particle dispersion liquid in which this was dispersed in methanol was prepared. Further, silica fine particles (Nippon Aerosil Co., Ltd .: R812S, average primary particle size 12 nm) subjected to surface treatment with a dimethylsiloxane-based silane coupling agent by a dry method were used as the hydrophobic fine particles 4b, and these were dispersed in methanol. A particle dispersion was prepared. Then, both particle dispersions were mixed to produce a mixed particle dispersion. The mixing ratio of both particle dispersions is such that the large particles 4a in the anti-adhesion layer occupy 40% by mass and the hydrophobic fine particles 4b account for 60% by mass with respect to the total amount of both particles 4a, 4b.

  As in Example 1, the hydrolyzed silica sol was used as the material for the binder 4c of the adhesion preventing layer 4.

And these mixed particle dispersion liquids and the binder 4c were mixed so that solid content weight ratio might be the ratio of 1: 1, and it diluted so that it might become solid content 6 mass%, and prepared the coating liquid. Then, this coating solution was applied onto the heat seal layer 3 and heated to dry and harden, thereby forming the adhesion preventing layer 4 to obtain the lid material of Example 2. The application method is gravure coating, and the wet application amount is 1.5 g / m ² .

(Example 3)
A lid material was produced in the same manner as in Example 1 except that the type, particle diameter, and blending ratio of the large particles 4a and hydrophobic fine particles 4b in the adhesion preventing layer 4 included in the adhesion preventing layer 4 were different from those in Example 1.

  That is, first, the anchor coat layer 2 and the heat seal layer 3 were formed on the substrate 1 in the same manner as in Example 1.

  As the large particles 4a in the adhesion preventing layer, hydrophobic silica fine particles (manufactured by Fuji Silysia Co., Ltd .: Silo Hovic 100, average primary particle size 3 μm) were used, and a particle dispersion liquid in which this was dispersed in methanol was prepared. Further, silica fine particles (manufactured by Nippon Aerosil Co., Ltd .: RY200S, average primary particle size 16 nm) subjected to surface treatment with a dimethylsiloxane-based silane coupling agent by a dry method were used as the hydrophobic fine particles 4b, and these were dispersed in methanol. A particle dispersion was prepared. Then, both particle dispersions were mixed to produce a mixed particle dispersion. The mixing ratio of both particle dispersions is such that the large particles 4a in the anti-adhesion layer occupy 40% by mass and the hydrophobic fine particles 4b account for 60% by mass with respect to the total amount of both particles 4a, 4b.

  As in Example 1, the hydrolyzed silica sol was used as the material for the binder 4c of the adhesion preventing layer 4.

And these mixed particle dispersion liquids and the binder 4c were mixed so that solid content weight ratio might be the ratio of 1: 1, and it diluted so that it might become solid content 6 mass%, and prepared the coating liquid. Then, this coating solution was applied onto the heat seal layer 3 and heated to dry and harden, thereby forming the adhesion preventing layer 4 to obtain the lid material of Example 3. The application method is gravure coating, and the wet application amount is 1.5 g / m ² .

Example 4
A lid material was produced in the same manner as in Example 1 except that the type and particle size of the anchor coat layer inner particles 2a included in the anchor coat layer 2 were different from those in Example 1.

  That is, a solution of a two-part curable polyester resin (manufactured by DIC: A970) was used as the binder 2b of the anchor coat layer 2, and styrene particles (average particle size 50 μm) were used as the particles 2a in the anchor coat layer. And the coating liquid was prepared by disperse | distributing the particle 2a in anchor coat layer in this binder solution, this coating liquid was apply | coated and dried on the polyester film surface of the base material 1, and the anchor coat layer 2 was formed.

  And the heat seal layer 3 and the adhesion prevention layer 4 were formed similarly to Example 1, and it was set as the cover material of Example 4.

(Comparative Example 1)
This example is an example of a lid member that is different from the first embodiment in the following two points.

  One difference is that in Example 1, the anchor coat layer 2 is mixed with the particles 2a in the anchor coat layer to provide irregularities on the surface of the adhesion preventing layer 4, but in Comparative Example 1, heat sealing is performed. Particles were mixed in the layer 3 and the surface of the adhesion preventing layer 4 was provided with irregularities by the particles in the heat seal layer.

  The second difference is that in Example 1, the adhesion preventing layer 4 is mixed with the hydrophobic fine particles 4b together with the large particles 4a in the adhesion preventing layer. In Comparative Example 1, the adhesion preventing layer 4 has This is because the large particles 4a in the adhesion preventing layer are not mixed, and only the hydrophobic fine particles 4b are mixed.

  The lid material of Comparative Example 1 was manufactured as follows (see FIG. 2).

  That is, first, as the base material 1, similarly to Example 1, a laminate of a polyester film having an aluminum vapor deposition layer and paper was used.

  As the material of the anchor coat layer 2, a urethane-based anchor coat agent was used, and this was gravure coated on the substrate 1 to form the anchor coat layer 2. The anchor coat layer inner particles 2a are not included.

  As the heat sealable resin 3b of the heat seal layer 3, an acrylic heat seal resin (manufactured by DIC: A450) was used. Then, spherical particles (particles in the heat seal layer) 3a were mixed with the heat sealable resin 3b to produce a coating solution for forming the heat seal layer 3. The material of the heat seal layer inner particles 3a is an acrylic resin, and the particle diameter is 20 μm. The solid content of the coating solution is 30% by weight.

The heat seal layer 3 forming coating solution thus produced was applied onto the anchor coat layer 2 and dried to form the heat seal layer 3. The coating amount is 4.0 g / m ² . And the unevenness | corrugation based on the particle | grain 3a in heat seal layer was formed in the surface of the heat seal layer 3 formed in this way.

  Next, silica fine particles (manufactured by Nippon Aerosil Co., Ltd .: RY200S, average primary particle size 16 nm) surface-treated with a dimethylsiloxane-based silane coupling agent by a dry method are used as the hydrophobic fine particles 4b, which are dispersed in methanol. A prepared particle dispersion was prepared.

  Further, as a binder material 4c of the adhesion preventing layer 4, tetraethoxysilane (TEOS) was mixed with hydrochloric acid to hydrolyze tetraethoxysilane (TEOS) to prepare a silica sol.

And these particle dispersion liquid and binder 4c are mixed so that solid content weight ratio may be the ratio of 1: 1, it is set as a coating liquid, it apply | coats on the heat seal layer 3, and it heats and hardens by drying. Thus, an adhesion preventing layer 4 was formed to obtain a cover material of Comparative Example 1. The application method is gravure coating, and the wet application amount is 1.5 g / m ² . On the surface of the formed adhesion preventing layer 4, large irregularities based on the heat seal layer inner particles 3a and fine irregularities based on the hydrophobic fine particles 4b were formed so as to overlap each other.

(Comparative Example 2)
This example is an example of a lid material different from the first embodiment in the following three points (see FIG. 3).

  One difference is that in Example 1, the anchor coat layer 2 is provided, but in Comparative Example 2, a polyethylene resin layer 2 ′ is provided by an extrusion coating method instead of the anchor coat layer 2.

  In addition, the second difference is that in Example 1, the anchor coat layer 2 is mixed with the anchor coat layer inner particles 2a to provide irregularities on the surface of the adhesion preventing layer 4, but in this comparative example 2, The particles 3a are mixed with the heat seal layer 3, and the surface of the adhesion preventing layer 4 is provided with irregularities by the particles 3a in the heat seal layer.

  The third difference is that in Example 1, the anti-adhesion layer 4 is mixed with the hydrophobic fine particles 4b together with the large particles 4a in the anti-adhesion layer. This is because the large particles 4a in the adhesion preventing layer are not mixed, and only the hydrophobic fine particles 4b are mixed.

  The lid material of Comparative Example 2 was manufactured as follows.

  That is, first, as the base material 1, similarly to Example 1, a laminate of a polyester film having an aluminum vapor deposition layer and paper was used.

  Then, a polyethylene resin layer 2 'was provided by melt extrusion coating of a polyethylene resin on the polyester film surface of the substrate 1. The thickness is 15 μm.

  A hot melt resin was used as the heat sealable resin 3 b of the heat seal layer 3. Then, spherical particles (particles in the heat seal layer) 3a were mixed with the heat sealable resin 3b to produce a coating solution for forming the heat seal layer 3. The material of the heat seal layer inner particles 3a is an acrylic resin, and the particle diameter is 15 μm.

The heat seal layer 3 forming coating solution thus produced was applied onto the anchor coat layer 2 and dried to form the heat seal layer 3. The coating amount is 20.0 g / m ² . And the unevenness | corrugation based on the particle | grain 3a in heat seal layer was formed in the surface of the heat seal layer 3 formed in this way.

  The adhesion preventing layer 4 was formed in the same manner as in Comparative Example 1.

(Comparative Example 3)
A lid was produced in the same manner as in Example 1 except that the blending ratio of the large particles 4a in the adhesion preventing layer, the hydrophobic fine particles 4b and the binder 4c contained in the adhesion preventing layer 4 was different from that in Example 1.

  That is, the blending ratio of the large particles 4a in the adhesion preventing layer and the hydrophobic fine particles 4b is 90% by mass for the large particles 4a in the adhesion preventing layer and 10% for the hydrophobic fine particles 4b with respect to the total amount of both particles 4a and 4b. It is the ratio of mass%. The blending ratio of the particles 4a and 4b and the binder 4c is 1: 1 by weight.

(Comparative Example 4)
A lid was produced in the same manner as in Example 1 except that the blending ratio of the large particles 4a in the adhesion preventing layer, the hydrophobic fine particles 4b and the binder 4c contained in the adhesion preventing layer 4 was different from that in Example 1.

  That is, the blending ratio of the large particles 4a in the anti-adhesion layer and the hydrophobic fine particles 4b is 50% by mass for the large particles 4a in the anti-adhesion layer and 50% for the hydrophobic fine particles 4b with respect to the total amount of both particles 4a and 4b. It is the ratio of mass%. The blending ratio of the particles 4a and 4b and the binder 4c is 1: 1 by weight.

(Evaluation)
The lid materials of Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated for heat sealability, water adhesion prevention, and yogurt adhesion prevention.

  That is, first, these lid materials are cut into strips having a width of 15 mm to form test pieces, and the test pieces are heat sealed to polystyrene resin with a cup sealer, and the heat seal strength is measured to evaluate the heat seal suitability. did. The heat seal strength was measured with a tensile tester (Tensilon). Peeling was performed at an angle of 150 degrees. The tensile speed is 300 mm / min. Each lid member was measured three times, and the average value was defined as the heat seal strength (N / 15 mm).

  Water was dropped on each cover material, and the contact angle and the fall angle were measured to evaluate the adhesion prevention property. In addition, yogurt (manufactured by Danone Japan Co., Ltd .: Danone BIO yogurt / plain sweetened sugar) was dropped and the falling angle was measured. This is because the contact angle of yogurt cannot be measured directly.

  Table 1 shows the measurement results of these heat sealability and adhesion prevention properties.

From these results, when the large particles in the anti-adhesion layer are mixed in addition to the hydrophobic fine particles in the anti-adhesion layer, the large particles in the anti-adhesion layer with respect to the total amount of the hydrophobic fine particles and the large particles in the anti-adhesion layer When the blending amount is 20% by mass (Examples 1 and 4) or 40% by mass (Examples 2 and 3), the anti-adhesion ability is drastically maintained while maintaining sufficient heat sealability. Can be understood to improve. In the case where the large particles in the anti-adhesion layer were not mixed (Comparative Examples 1 and 2) or when the amount of the large particles in the anti-adhesion layer was 50% by mass or more (Comparative Examples 3 and 4), the adhesion prevention Sexual ability cannot be improved sufficiently.

1: base material 2: anchor coat layer 2a: particles in anchor coat layer 2b: binder 2 ′: polyethylene layer 3: heat seal layer 3a: particles in heat seal layer 3b: binder 4: adhesion prevention layer 4a: in adhesion prevention layer Large particle 4b: hydrophobic fine particle 4c: binder

Claims (7)

A cover material comprising a base material, an anchor coat layer, a heat seal layer, and an adhesion preventing layer for preventing adhesion of the contents in this order, wherein the anchor coat layer is a particle having an average particle diameter of 1 to 100 μm in the binder (Anchor coat layer particle) is composed of a dispersed composition, and the adhesion preventing layer contains hydrophobic fine particles having a particle diameter of 1 to 100 nm, and unevenness based on the anchor coat layer particle is formed. In the lid formed on the adhesion prevention layer surface,
In addition to the hydrophobic fine particles, large particles (large particles in the anti-adhesion layer) having a particle size 10 to 4000 times that of the hydrophobic fine particles are contained in the anti-adhesion layer, and A lid material, wherein the blending amount of the large particles is less than 50 mass with respect to the total amount of the hydrophobic fine particles and the large particles in the adhesion preventing layer.   The lid material according to claim 1, wherein the particle size of the large particles in the adhesion preventing layer is smaller than the particle size of the particles in the anchor coat layer.   The lid material according to claim 1 or 2, wherein the large particles in the adhesion preventing layer are inorganic oxide particles whose surface is treated with a hydrophobic functional group.   The lid material according to claim 3, wherein the surface treatment is a treatment with a silane coupling agent or a silylating agent.   The lid according to any one of claims 1 to 4, wherein the adhesion preventing layer contains a binder for fixing both of the particles in addition to the hydrophobic fine particles and the large particles in the adhesion preventing layer. Wood.   The lid material according to claim 5, wherein the binder of the adhesion preventing layer is a resin selected from a polyester resin, an acrylic resin, a polyurethane resin, an epoxy resin, a melamine resin, a phenol resin, and a silicone resin.   The lid member according to any one of claims 1 to 6, wherein a material of the particles in the anchor coat layer is a metal oxide or a resin.

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