JP7215843B2 - overlaminate film - Google Patents

Description

The present invention relates to overlaminate films.

The overlaminate film is used by being overlaminated on a sheet adherence surface having a printed layer or the like. This protects the adherend surface of the printed layer or the like. An overlaminate film usually has a structure in which a base material for protecting the adherend surface and an adhesive layer for adhering the adhesive sheet itself to the adherend surface are laminated.

In addition, by attaching an overlaminate film to an adherend such as a sheet, the adherend is given aesthetics such as a high-class feeling. For example, by making the overlaminate film matte, the sheet can be made to have a high-class appearance. As a matte overlaminate film, for example, in Patent Document 1, a matte overlaminate film obtained by laminating a resin layer mainly composed of a plurality of resins having a low ash content and different melting points on a polypropylene film and stretching it. A laminate film is disclosed.

JP 2003-062954 A

Overlaminate film is used by being laminated (attached) to the base (adherent) of labels, stickers, etc., so the user can clearly see the image printed on the base and the color of the base. is required. Specifically, (1) there is no or little reflection of fluorescent lights, etc. after the overlaminate film is applied, and (2) the information on the base is clearly visible to the user after the overlaminate film is applied. Desired.

In addition, after affixing an overlaminate film to a label containing product information, etc., it is desired to print variable information necessary for product management, such as barcodes and lots, on the overlaminate film by thermal transfer for each product. there is Therefore, the overlaminate film is also required to have thermal transfer printability.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an overlaminate film that suppresses the glare of fluorescent lamps, etc., allows the background to be clearly visually recognized, and has improved thermal transfer printability.

The present invention is an overlaminate film comprising, in this order, a matte layer containing particles, a resin substrate and an adhesive layer, having a total light transmittance of 80% or more, and a 60° specular gloss of the surface of the matte layer. 20% or less, and the surface free energy of the mat layer is 42 mJ/m ² or more.

According to the overlaminate film of the present invention, even after being attached to a substrate such as a label, reflection of a fluorescent lamp or the like is suppressed, the substrate is clearly visible, and thermal transfer printability is improved.

It is a cross-sectional schematic diagram which shows 1st embodiment of an overlaminate film. It is an example of use of the overlaminate film of the first embodiment. It is another usage example of the overlaminate film of the first embodiment.

A first embodiment of the present invention is an overlaminate film comprising, in this order, a matte layer containing particles, a resin base material and an adhesive layer, and having a total light transmittance of 80% or more and 60% of the surface of the matte layer. The overlaminate film has a specular gloss of 20% or less and a surface free energy of the matte layer of 42 mJ/m ² or more.

According to this aspect, even after being attached to a substrate (adherend) such as a label, reflection of a fluorescent lamp or the like is suppressed. This can be achieved by controlling the optical properties of the overlaminate film so that the matte layer surface has a 60° specular gloss of 20% or less. Moreover, even if the overlaminate film is laminated, the visibility of the underlying image, etc. is not impaired. This can be achieved by controlling the optical properties of the overlaminate film such that the total light transmittance is 80% or more.

In addition, the present inventor thought that if the surface of the overlaminate film could be printed, variable information such as a bar code that differs for each product could be added in addition to the information printed on the adherend. Focusing on the properties of the matte layer on the surface of the overlaminate film, various studies were conducted, and as a result, it was found that by controlling the surface free energy of the matte layer to 42 mJ/m ² or more, the affinity of the thermal transfer ribbon with the ink by the thermal transfer method was improved. It has been found that the thermal transfer printability can be improved.

FIG. 1 is a schematic cross-sectional view showing a first embodiment of an overlaminate film. The mat layer 11, the resin base material 12, the adhesive layer 13, and the release liner 14 are shown in the overlaminate film 10 of FIG. The matte layer 11 is arranged as the outermost layer (the outermost surface facing the adhesive layer 13) and has a matte texture, which serves to impart a new design property, for example, a high-class feeling to the base. In addition, by arranging the mat layer as the outermost layer, the mat layer also functions as a print receiving layer for printing by the thermal transfer method. The resin substrate 12 is a support for the overlaminate film, and plays a role in protecting the substrate and securing the mechanical strength of the overlaminate film. The pressure-sensitive adhesive layer 13 is a member formed from a pressure-sensitive adhesive composition and directly attached to an adherend. The release liner 14 is a member that is used before the overlaminate film is attached to the adherend, protects the pressure-sensitive adhesive layer 13, and has the function of preventing a decrease in adhesiveness before use.

In the form of the overlaminate film of FIG. 1, another intermediate layer may be present between each layer of the mat layer 11, the resin base material 12, and the adhesive layer 13, but from the viewpoint of thinning, The overlaminate film is preferably composed of a mat layer, a resin substrate and an adhesive layer. In this laminate, a printed layer may be formed by printing on the mat layer, or a release liner 14 may be provided to protect the adhesive layer 13 .

The overlaminate film 10 of this embodiment is used by sticking it on various labels or stickers via the pressure-sensitive adhesive layer 13 . FIG. 2 is an example of use of the overlaminate film of the first embodiment, and is a schematic diagram showing a mode in which the overlaminate film is overlaminated on another pressure-sensitive adhesive sheet. In FIG. 2, the adhesive sheet 30 is attached in advance on an object to be adhered (for example, a plastic container). The adhesive sheet 30 is composed of a printed layer 31 , a substrate 32 and an adhesive layer 33 . The print layer 31 includes characters, figures, numbers, etc., and is information such as product names and details of products, for example. The overlaminate film 10 from which the release liner 14 has been removed is attached via the adhesive layer 13 onto the printed layer 31 of the adhesive sheet 30 (on the surface facing the adhesive layer 33 ). By laminating the overlaminate film 10 on the adhesive sheet 30 in this way, the adherend surface of the adhesive sheet such as the printed layer is protected, and the overlaminate film imparts a matte texture. When viewed through the adhesive sheet, the adhesive sheet has a high-grade appearance, and by reducing the glossiness, the visibility of the adherend surface of the pressure-sensitive adhesive sheet can be further improved.

FIG. 2 shows a form in which the overlaminate film is attached to the adhesive sheet via the adhesive layer while the adhesive sheet is attached to the adherend. After being attached to the adhesive sheet, it may be attached to the adherend via the adhesive layer of the adhesive sheet (Fig. 3). In FIG. 3, the adhesive sheet 30 is composed of a printed layer 31, a base material 32, an adhesive layer 33 and a release liner . The overlaminate film 10 from which the release liner 14 has been removed is attached onto the printed layer 31 of the adhesive sheet 30 via the adhesive layer 13 (FIG. 3(B)). Then, from the laminate in which the overlaminate film 10 is laminated on the adhesive sheet 30 in this way, the release liner 34 of the adhesive sheet is removed, and the adhesive layer 33 of the adhesive sheet is applied to the adherend via the adhesive layer 33 ( FIG. 3(C)).

Although FIG. 2 and FIG. 3 exemplify the form in which the adhesive sheet has the printed layer 31, the adhesive sheet 30 may have a form in which the printed layer 31 is not provided.

The present embodiment will be described in detail below.

In this specification, "X to Y" indicating a range means "X or more and Y or less". In addition, unless otherwise specified, operations, physical properties, etc. are measured under the conditions of room temperature (20 to 25° C.)/relative humidity of 45 to 55%. As used herein, "(meth)acrylate" refers to "acrylate or methacrylate" and "(meth)acrylic acid" refers to "acrylic acid or methacrylic acid." In addition, the concept of adhesive film includes what is called adhesive tape, adhesive label, adhesive sheet, and the like.

(60° specular gloss)
The matte layer surface (outermost surface) of the overlaminate film of the present embodiment has a 60° specular gloss of 20% or less. If the 60° specular glossiness exceeds 20%, the reflection of a fluorescent lamp or the like on the overlaminate film is remarkably deteriorated, and the visibility of the base is remarkably decreased (Comparative Examples 1 to 4 described later). The 60° specular glossiness is preferably 15% or less, more preferably 12% or less, and particularly preferably 10% or less. Since the lower the 60° specular glossiness is, the better, the lower limit is not particularly limited, but since printing, particularly by thermal transfer, is easy, it is preferably 1% or more, and preferably 2% or more. more preferred. When the overlaminate film has a printed layer, the 60° specular glossiness may be measured at a portion where the matte layer is exposed.

The 60° specular glossiness can be controlled by the content of particles in the matte layer, the particle size of the particles in the matte layer, the thickness of the matte layer, and the like. As the content of particles in the matte layer increases, the 60° specular gloss tends to decrease. Further, when the thickness of the matte layer becomes thin, the 60° specular gloss tends to increase. Furthermore, the 60° specular gloss tends to decrease as the particle diameter of the particles in the matte layer increases.

The 60° specular glossiness is measured according to JIS Z8741:1997 using a gloss meter "VG7000" manufactured by Nippon Denshoku Industries Co., Ltd.

(Total light transmittance)
The total light transmittance of the overlaminate film of this embodiment is 80% or more. If the total light transmittance is less than 80%, letters and patterns on the base such as the printed layer become unclear, and the image definition of the base is remarkably lowered (Comparative Example 5 described later). The total light transmittance is preferably 85% or more, more preferably 88% or more, and even more preferably 90% or more. Although the upper limit of the total light transmittance is 100%, it is usually 95% or less.

The total light transmittance can be controlled by controlling the type of particles in the matte layer, the particle size of the particles in the matte layer, and the balance of the particle content. When the content of particles in the matte layer exceeds a certain value, the total light transmittance tends to decrease.

"Total light transmittance" is a value defined by JIS K7361-1:1997. When the overlaminate film has a release liner, after removing the release liner, the total light transmittance is measured with the pressure-sensitive adhesive layer exposed.

(haze)
The haze of the overlaminate film of this embodiment is preferably 70% or more. When the haze is 70% or more, the matte feeling is improved and the design is improved, which is preferable. More preferably, the haze is 75% or more. Also, the haze is preferably 95% or less.

"Haze" is a value measured according to JIS K7136:2000. When the overlaminate film has a release liner, after removing the release liner, the haze is measured with the pressure-sensitive adhesive layer exposed.

The haze can be controlled by the content of particles in the matte layer, the type of particles in the matte layer, the thickness of the matte layer, the type of binder resin, and the like. The higher the particle content in the matte layer, the higher the haze.

(mat layer containing particles)
The matte layer contains particles to give the overlaminate film a matte texture. At least part of the mat layer is exposed on the outermost surface, and the design of the mat layer is visible from the outside.

Particles contained in the matte layer are blended for the purpose of providing a matte appearance. The particles may be either inorganic particles or organic particles. Examples of inorganic particles include zirconia, silica, titanium dioxide, kaolin, alumina, titania, zeolite, calcium carbonate, barium sulfate, magnesium hydroxide, calcium phosphate, glass, mica, and talc. Examples of organic particles include acrylic resin particles such as polymethyl methacrylate, polystyrene particles, styrene-acrylic resin particles, and polycarbonate particles. Among these particles, silica and acrylic resin particles are preferable, and silica is more preferable, because desired optical properties, particularly total light transmittance, can be easily obtained.

Since silica has excellent dispersibility in a binder and can form a uniform matte layer, it is preferably hydrophobic silica that has been made hydrophobic by surface treatment. As the hydrophobic silica, for example, silica particles made hydrophobic by substituting hydroxyl groups on the surfaces of hydrophilic silica particles with methylsilane or the like can be used. Commercially available hydrophobic silica may be used, for example, Nipsil (registered trademark) series manufactured by Tosoh Silica Corporation can be used.

The average particle diameter of the particles is preferably 1.0 μm or more, more preferably 1.5 μm or more, from the viewpoint of suppressing glare of a fluorescent lamp or the like. Although the upper limit of the average particle size of the particles is not particularly limited, it is preferably 20 μm or less from the viewpoint of preventing the particles from falling off when the mat layer is rubbed. In the present specification, the average particle size refers to the volume-based average particle size unless otherwise specified. can be obtained by measuring with an aperture of 50 μm.

The content of the particles in the matte layer preferably exceeds 10% by weight. When the content of the particles in the matte layer exceeds 10% by mass, it is possible to suppress glare of a fluorescent lamp or the like. More preferably, the content of the particles in the mat layer is 15% by mass or more. From the viewpoint of the mechanical properties of the mat layer, the content of the particles in the mat layer is preferably 50% by mass or less, more preferably 30% by mass or less, and further preferably 25% by mass or less. It is preferably 20% by mass or less, and particularly preferably 20% by mass or less.

In addition to the particles, the mat layer preferably contains a binder resin for binding the particles. Examples of binder resins include polyester-based resins, polyolefin-based resins, polyamide-based resins, polyurethane-based resins, polystyrene-based resins, acrylic-based resins, and the like. Among these, polyester-based resins, polyurethane-based resins, and acrylic-based resins are preferable, and polyester-based resins are more preferable, from the viewpoint of ink transferability of the thermal transfer ribbon provided on the mat layer.

The polyester-based resin will be described in detail below.

A polyester is a polymer having an ester bond in its main chain, which is obtained by copolymerizing a polyol as a monomer and a polyvalent carboxylic acid.

Examples of the above polyol include ethylene glycol, propylene glycol, neopentyl glycol, cyclohexanedimethanol, tricyclodecanedimethanol and the like.

On the other hand, examples of the polyvalent carboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalenedicarboxylic acid.

The combination of these polyols and polycarboxylic acids is not particularly limited, and the polyester may be a polymer related to a combination of one type, or a polymer related to a combination of multiple types.

Furthermore, the polyester-based resin may be a urethane-modified polyester resin (polyester urethane). A specific example of the urethane-modified polyester resin is obtained by reacting various polyisocyanate compounds with a polyester polyol having a hydroxyl group at the end of the polymer obtained by condensation polymerization of the above polyol and a carboxylic acid component. polymer (polyester urethane) and the like.

Polyisocyanate compounds include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate and naphthalene diisocyanate.

The number average molecular weight (Mn) of the urethane-modified polyester resin is preferably from 2,000 to 100,000, more preferably from 5,000 to 50,000. Here, the number average molecular weight (Mn) is the number average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

From the viewpoint of thermal transfer printability, the glass transition temperature of the urethane-modified polyester resin is preferably 100°C or less, more preferably -40 to 100°C.

The content of the urethane-modified polyester resin in the mat layer is preferably 70 to 85 mass %.

A commercial product may be used as the urethane-modified polyester resin, and commercial products include Vylon series (trade name) manufactured by Toyobo Co., Ltd. Vylon UR-1700 (number average molecular weight: 16,000, Tg: 92°C). , Vylon UR-2300 (number average molecular weight 32,000, Tg 18°C), Vylon UR-3200 (number average molecular weight 40,000, Tg-3°C), Vylon UR-3210 (number average molecular weight 40,000, Tg-3 ° C.), Vylon UR-3500 (number average molecular weight 40,000, Tg 10 ° C.), Vylon UR-6100 (number average molecular weight 25,000, Tg -30 ° C.), Vylon UR-8200 (number average molecular weight 25,000, Tg 73 ° C.), Vylon UR-8300 (number average molecular weight 30,000, Tg 23° C.), Vylon UR-8700 (number average molecular weight 32,000, Tg -22° C.), etc. can be preferably used.

A urethane-modified polyester resin is preferable among various polyesters because it has particularly excellent adhesion to a printing layer, particularly to a printing layer by a thermal transfer method (excellent printability). That is, in a preferred embodiment of the present invention, the mat layer contains a binder resin, and the binder resin contains a urethane-modified polyester resin.

The film thickness of the mat layer is preferably 2 μm or more. When the thickness of the mat layer is 2 μm or more, the 60° specular glossiness can be easily controlled to a desired value, and printability is improved, which is preferable. The film thickness of the mat layer is preferably 2 to 10 μm.

The matte layer has a surface free energy of 42 mJ/m ² or more. When the surface free energy of the matte layer is less than 42 mJ/m ² , the thermal transfer printability is poor (Comparative Example 6 described later). More preferably, the surface free energy of the mat layer is 45 mJ/m ² or more. The surface free energy of the mat layer is usually 73 mJ/m ² or less, preferably 60 mJ/m ² or less.

The surface free energy of the matte layer was determined by measuring the contact angles of water, diiodomethane, and 1-bromonaphthalene with respect to the matte layer using a contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd.). Japan Adhesive Society", 1972, Vol. 8, No. 3, pp. 131-141). When the overlaminate film has a printed layer, the surface free energy may be measured at the portion where the matte layer is exposed.

The surface free energy of the matte layer can be controlled by the type of binder resin used in the matte layer. Also, the surface free energy can be controlled by the hydrophobicity of the mat layer. For example, the surface free energy tends to decrease when a hydrophobic additive or an additive having a hydrophobic group (for example, organic tin, which is a cross-linking reaction accelerator) is added.

(Resin base material)
The resin base material is preferably a transparent base material because the pattern of the label underneath needs to be visually observed from the outside. Here, the term “transparent” means that the transmittance in the visible light region is 80% or more, preferably 90% or more (upper limit 100%). Here, the transmittance of the resin base material can be measured according to JIS K7361-1:1997 (Plastics—Testing method for total light transmittance of transparent materials).

Materials constituting the transparent substrate are not particularly limited, and examples thereof include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin films such as polyethylene and polypropylene; cellophane, diacetylcellulose film, and triacetylcellulose film. , Acetyl cellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, fluorine resin film, acrylic resin film, norbornene resin film, cyclic olefin system films and the like. Among these, from the viewpoint of transparency, the resin substrate is preferably polyester or polyolefin, more preferably polyethylene terephthalate, polyethylene or polypropylene, and still more preferably polyethylene terephthalate.

The resin base material may contain stabilizers, lubricants, softeners, ultraviolet absorbers, antioxidants, antistatic agents, anti-twisting agents, etc., as required.

Although the thickness of the resin base material is not particularly limited, it is preferably 5 to 250 μm.

(Adhesive layer)
The adhesive used in the adhesive layer is not particularly limited, and acrylic adhesives, synthetic rubber adhesives, silicone adhesives, urethane adhesives, and the like can be used. The pressure-sensitive adhesives may be used singly or in combination of two or more.

As the adhesive, an acrylic adhesive can be particularly preferably used from the viewpoint of adhesion reliability. The acrylic polymer that constitutes the acrylic pressure-sensitive adhesive has (meth)acrylic acid alkyl ester as the main monomer component, and if necessary, a monomer that can be copolymerized with (meth)acrylic acid alkyl ester (copolymerizable monomer).

Examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylate, Isobutyl acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, (meth)acrylate ) dodecyl acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, and stearyl (meth)acrylate. These may be used alone or in combination of two or more.

As a monomer (copolymerizable monomer) copolymerizable with (meth)acrylic acid alkyl ester, it is preferable to use a monomer having a crosslinkable functional group, specifically, (meth)acrylic acid hydroxyl group-containing monomers such as hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; (meth)acrylic acid, itaconic acid, carboxyl group-containing monomers such as maleic acid and fumaric acid; and amino group-containing monomers such as aminoethyl (meth)acrylate and (meth)acryloylmorpholine.

Other copolymerizable monomers include vinyl acetate and styrene.

Although the weight average molecular weight of the acrylic polymer is not particularly limited, it is preferably 100,000 to 1,000,000. In addition, a weight average molecular weight is the value of polystyrene conversion measured by the gel permeation chromatography (GPC) method.

The adhesive preferably contains a cross-linking agent in addition to the acrylic polymer. Examples of cross-linking agents include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, and metal chelate-based cross-linking agents. The amount of the cross-linking agent added is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 0.5 parts by mass, based on 100 parts by mass of the acrylic polymer.

An ultraviolet absorber, an antioxidant, an antistatic agent, a tackifier, an emulsifier, a leveling agent, an antifoaming agent, an antiseptic, and the like can be appropriately added to the pressure-sensitive adhesive layer, if necessary.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably in the range of 10 to 50 μm from the viewpoint of adhesiveness and thinning.

(Release liner)
Examples of the release liner include, but are not limited to, polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; plastic films such as polyolefin films such as polypropylene and polyethylene; Paper such as clay coated paper can be used.

The thickness of the release liner is usually about 10-400 μm. Moreover, a layer made of a release agent made of silicone or the like may be provided on the surface of the release liner to improve the releasability from the pressure-sensitive adhesive layer. When such a layer is provided, the thickness of the layer is usually about 0.01 to 5 μm.

(Production method)
Although the method for producing the overlaminate film of the present invention is not particularly limited, an example is shown below.

First, a mat layer is formed on a resin substrate.

The method of forming the mat layer is not particularly limited, but it can be obtained by applying a composition containing particles, a binder resin and optionally a solvent onto a resin substrate. Specific examples of usable solvents include ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and acetylacetone; esters such as ethyl acetate and butyl acetate; hydrocarbons such as toluene and xylene; and organic solvents such as alcohols such as isopropyl alcohol. These solvents may be used alone or in combination of two or more.

Application of the composition onto the resin base material may be performed by a known method, and examples thereof include methods using various coaters such as a gravure coater and a Meyer bar coater.

Thus, a laminate of the resin substrate and the mat layer is obtained.

The method of forming the pressure-sensitive adhesive layer is not particularly limited, but it can be obtained, for example, by applying a pressure-sensitive adhesive composition onto a release liner and then drying it. The method of applying the pressure-sensitive adhesive composition is not particularly limited, and for example, it is applied using a known coating device such as a roll coater, knife coater, air knife coater, bar coater, blade coater, slot die coater, lip coater, and gravure coater. be able to. A pressure-sensitive adhesive layer is formed by applying a pressure-sensitive adhesive onto a release liner and then performing a drying treatment. The drying conditions at this time are not particularly limited, and, for example, the drying is performed at 60 to 150° C. for 10 to 60 seconds.

Also, an overlaminate film can be obtained by attaching a resin substrate having a mat layer formed on the pressure-sensitive adhesive layer surface of the laminate of the release liner and the pressure-sensitive adhesive layer thus obtained.

The overlaminate film of the present embodiment is excellent in printability on the mat layer, particularly in printability by a thermal transfer method. For this reason, in the overlaminate film, a form having a printing layer for printing on the mat layer is also a suitable form.

The printed layer is a layer printed with characters, figures, numbers, etc., and may be a layer printed with information such as a bar code, lot, expiration date, etc., for example.

The method for forming the printed layer is not particularly limited, and an image can be drawn using various printers such as an electrophotographic system, a thermal transfer system, an inkjet system, and the like. Among them, the printing layer is preferably formed by a thermal transfer method or an ink jet method, and more preferably by a thermal transfer method, because variable information can be easily printed.

The printed layer is printed on a part of the mat layer by, for example, a thermal transfer method, and is not printed on the entire surface of the mat layer.

The thermal transfer ribbon used in the thermal transfer method is not particularly limited, and those described in JP-A-2004-268571 and the like can be used. Also, the thermal transfer recording method is not particularly limited, and a method similar to that described in JP-A-2004-268571 can be used. For example, by heating the thermal transfer ribbon with a thermal head, at least a part of the release layer and the ink layer is peeled off from the support of the thermal transfer ribbon and transferred onto the mat layer.

In addition, the timing of printing by the thermal transfer method is not particularly limited, even in the state of the overlaminate film alone, after overlaminating to the adhesive sheet, and even after attaching the adhesive sheet and the overlaminate film to the adherend. good.

In this embodiment, since it is possible to print on the matte layer of the overlaminate film, after attaching the overlaminate film to a label containing product information, etc., product management such as barcodes and lot numbers can be displayed on the overlaminate film. It is possible to print variable information necessary for each product.

Furthermore, as another embodiment, there is a method for producing an overlaminate film, which further includes printing on the mat layer of the sheet of the first embodiment by a thermal transfer method.

(how to use)
Since the overlaminate film of the present invention exhibits the effects as described above, when the overlaminate film is applied to an adhesive sheet for various products, etc., it will be more eye-catching for consumers and purchasers. A beautiful appearance will be given. Such aesthetics is expected to strongly support marketing strategies for various products from the aspect of packaging. There is no particular limitation on the specific form of the products to which the overlaminate film of the present invention is applied, and it can be applied to products such as foods, cosmetics, nameplates, and products that require tamper prevention.

The effects of the present invention will be described using the following examples and comparative examples. Although "parts" or "%" may be used in the examples, "parts by mass" or "% by mass" are indicated unless otherwise specified. Also, unless otherwise specified, each operation is performed at room temperature (23° C.).

(Example 1)
Urethane-modified polyester resin (Vylon UR-8200 manufactured by Toyobo Co., Ltd.) 85 parts by mass (solid content) and silica (Nipsil (registered trademark) SS-50E manufactured by Tosoh Silica Co., Ltd., average particle size: 1.5 μm) 15 parts by mass They were mixed and diluted with toluene to prepare a matte layer-forming coating liquid having a solid content of 10% by mass.

On one side of a resin substrate (50 μm thick polyethylene terephthalate film (Lumirror (registered trademark) T-60), the above coating liquid is applied with a gravure coater, dried at 70 ° C. for 1 minute, and a binder resin A laminated film provided with a 3 μm-thick mat layer consisting of particles and particles was further cured at 23° C. and a relative humidity of 50% for 7 days.

A release liner (PET film coated with silicone) was coated with a transparent acrylic pressure-sensitive adhesive to form a pressure-sensitive adhesive layer (20 μm).

An overlaminate film was obtained by laminating the resin substrate surface of the laminate film obtained above to the pressure-sensitive adhesive layer on the release liner.

(Example 2)
An overlaminate film was obtained in the same manner as in Example 1, except that the amount of urethane-modified polyester resin added was changed from 85 parts by mass to 80 parts by mass, and the amount of silica added was changed from 15 parts by mass to 20 parts by mass.

(Example 3)
Instead of silica having an average particle size of 1.5 μm, silica having an average particle size of 2.0 μm (Nipsil (registered trademark) SS-50B manufactured by Tosoh Silica Co., Ltd.) was used in the same manner as in Example 1. to obtain an overlaminate film.

(Example 4)
Instead of silica having an average particle size of 1.5 μm, silica having an average particle size of 3.0 μm (Nipsil (registered trademark) SS-50C manufactured by Tosoh Silica Co., Ltd.) was used in the same manner as in Example 1. to obtain an overlaminate film.

(Comparative example 1)
An overlaminate film was obtained in the same manner as in Example 1, except that silica having an average particle size of 1.5 μm was not added.

(Comparative example 2)
An overlaminate film was obtained in the same manner as in Example 1, except that the amount of urethane-modified polyester resin added was changed from 85 parts by mass to 90 parts by mass, and the amount of silica added was changed from 15 parts by mass to 10 parts by mass.

(Comparative Example 3)
Instead of silica having an average particle size of 1.5 μm, a silica dispersion having an average particle size of 0.1 μm (MEK-ST-ZL manufactured by Nissan Chemical Industries, Ltd., solid content 30% by mass) was used, and the amount added was 15 parts by mass. to 80 parts by mass (solid content), and an overlaminate film was obtained in the same manner as in Example 1, except that the added amount of the urethane-modified polyester resin was changed from 85 parts by mass to 20 parts by mass.

(Comparative Example 4)
An overlaminate film was obtained in the same manner as in Example 1, except that the thickness of the mat layer was changed from 3 μm to 1 μm.

(Comparative Example 5)
An overlaminate film was obtained in the same manner as in Example 4, except that the amount of urethane-modified polyester resin added was changed from 85 parts by mass to 70 parts by mass, and the amount of silica added was changed from 15 parts by mass to 30 parts by mass.

(Comparative Example 6)
Urethane-modified polyester resin (Vylon UR-8200 manufactured by Toyobo Co., Ltd.) 85 parts by mass (solid content), silica (Nipsil (registered trademark) SS-50E manufactured by Tosoh Silica Co., Ltd., average particle size: 1.5 μm) 15 parts by mass, An isocyanate cross-linking agent (Coronate (registered trademark) HL, a polyisocyanate obtained by adding a polyhydric alcohol to hexamethylene diisocyanate, manufactured by Tosoh Corporation) 3 parts by mass (solid content) and 1 part by mass of dibutyltin dilaurate were mixed. An overlaminate film was obtained in the same manner as in Example 1.

(Evaluation Method 1: Fluorescent Light Reflection)
After removing the release liner from each of the overlaminate films of Examples and Comparative Examples, the pressure-sensitive adhesive layer was attached to the pressure-sensitive adhesive sheet having a printed layer as an adherend, and then the light of the fluorescent light was specularly reflected to reflect the fluorescent light. was determined visually according to the following criteria.
◯: Little glare due to reflection of a fluorescent lamp.
x: Significant glare due to reflection of a fluorescent lamp.

(Evaluation method 2: Evaluation of thermal transfer printability (printability))
A thermal transfer ribbon (manufactured by Ricoh Co., Ltd., product name "B110C") was used on the surface of the mat layer of each overlaminate film of Examples and Comparative Examples, and a thermal transfer printer (manufactured by Zebra Technologies, model name "140Xi4") was used to print at high speed. Printing was performed at 3 inches/sec. The thermal transfer printability of the thermal transfer ribbon was evaluated according to the following criteria.
○: Transfer of the thermal transfer ribbon is possible without any problem.
x: Transfer of the thermal transfer ribbon is impossible.

(Evaluation method 3: evaluation of the clarity (visibility) of the base)
After removing the release liner from each of the overlaminate films of Examples and Comparative Examples, the adhesive layer surface of the overlaminate film was attached to the printed layer surface of an adhesive sheet having a printed layer. The layered product was visually observed from above, the substrate was observed, and evaluation was made according to the following criteria.
◯: The print on the base is clearly visible, and the visibility is not impaired as compared with the visibility of the printed layer of the pressure-sensitive adhesive sheet before overlamination.
x: The printing of the base is slightly unclear, and the visibility is lower than the visibility of the printed layer of the pressure-sensitive adhesive sheet before overlamination.

From the above results, the overlaminate films of Examples 1 to 4, which are overlaminate films having a matte layer side 60° specular gloss value of 20% or less and a total light transmittance of 80% or more, are fluorescent lamps. There was little glare due to the reflection of light, the visibility of the background was excellent, and the printability was high. On the other hand, the overlaminate films of Comparative Examples 1 to 4, which had a 60° specular glossiness of more than 20%, exhibited very large glare due to reflection of a fluorescent lamp. In addition, the overlaminate film of Comparative Example 5, which had a total light transmittance of less than 80%, had poor visibility of the base. Furthermore, the overlaminate film of Comparative Example 6, in which the matte layer had a surface free energy of less than 42 mJ/m ² , lacked printability by the thermal transfer method (thermal transfer printability).

10, 20 overlaminate film,
11 mat layer,
12 resin substrate,
13 adhesive layer,
14 release liner,
30 adhesive sheet,
31 printing layer,
32 substrate,
33 adhesive layer,
34 release liner.

Claims (5)

An overlaminate film comprising, in this order, a mat layer containing particles, a resin substrate and an adhesive layer,
Total light transmittance is 80% or more,
The 60° specular glossiness of the surface of the matte layer is 20% or less,
The surface free energy of the mat layer is 42 mJ/m ² or more ,
An overlaminate film that is attached onto another adhesive sheet via the adhesive layer . 2. The overlaminate film according to claim 1, wherein the mat layer has a thickness of 2 [mu]m or more. 3. The overlaminate film according to claim 1, wherein the particles have an average particle size of 1.0 [mu]m or more. The overlaminate film according to any one of claims 1 to 3, wherein the content of said particles in the matte layer exceeds 10% by mass. The overlaminate film according to any one of claims 1 to 4, wherein the mat layer contains a binder resin, and the binder resin contains a urethane-modified polyester resin.

Images