JP2023040598A - Adhesive sheet - Google Patents

Abstract

To provide an adhesive sheet which is environmentally friendly and is excellent in adhesion of an ink.SOLUTION: The adhesive sheet of the present invention includes: a substrate constituted of a material containing a polyester resin; a coat layer for printing constituted of a material containing a high acid value polyester resin having an acid value of 10 mg KOH/g or more; and an adhesive layer provided on a surface side of the substrate opposite to a surface coated with the coat layer for printing. The substrate is preferably constituted of a material containing at least one selected from the group consisting of polyethylene terephthalate, polybutylene succinate, and polylactic acid. The high acid value polyester resin preferably has a glass transition temperature of 20°C or higher and 85°C or lower.SELECTED DRAWING: Figure 1

Description

The present invention relates to an adhesive sheet.

2. Description of the Related Art Adhesive sheets are known which are used for various types of printing and which are used by being attached to an adherend after printing.

Such a pressure-sensitive adhesive sheet is provided with a printing coat layer in order to improve adhesion to ink.

Conventionally, such a coating layer for printing has been formed using a solvent-based coating liquid (see, for example, Patent Document 1).

On the other hand, in order to deal with environmental problems in recent years, it is required to use environmentally friendly materials in the manufacturing process of various products.

In order to meet such demands, it is conceivable to form a coating layer for printing using a water-based coating liquid in the pressure-sensitive adhesive sheet as described above. There was a problem that the adhesion to the film could not be made sufficiently excellent.

In addition, when the base material is made of environmentally friendly biodegradable material, if a solvent-based coating solution is used to form a printing coat layer, the base material may be deformed due to the influence of the solvent. It is required to form a coating layer for printing using a coating liquid.

Japanese Patent No. 6030843

An object of the present invention is to provide a pressure-sensitive adhesive sheet that is environmentally friendly and has excellent ink adhesion.

Such objects are achieved by the present invention described in (1) to (6) below.
(1) a substrate made of a material containing a polyester-based resin;
a printing coat layer made of a material containing a high acid value polyester resin having an acid value of 10 mgKOH/g or more;
a pressure-sensitive adhesive layer provided on the surface of the base material opposite to the surface coated with the printing coat layer;
A pressure-sensitive adhesive sheet comprising:

(2) The pressure-sensitive adhesive sheet according to (1) above, wherein the substrate is made of a material containing at least one selected from the group consisting of polyethylene terephthalate, polybutylene succinate and polylactic acid.

(3) The pressure-sensitive adhesive sheet according to (1) or (2) above, wherein the high acid value polyester resin has a glass transition temperature of 20°C or higher and 85°C or lower.

(4) The printing coat layer is formed by applying a water-based composition containing the high acid value polyester resin and water onto the base material (1) to (3). ) The pressure-sensitive adhesive sheet according to any one of

(5) The pressure-sensitive adhesive sheet according to any one of (1) to (4) above, wherein no anchor coat layer is provided between the substrate and the printing coat layer.

(6) The pressure-sensitive adhesive sheet according to any one of (1) to (5) above, wherein the pressure-sensitive adhesive layer contains at least one of a biomass-based pressure-sensitive adhesive and an emulsion-type pressure-sensitive adhesive.

According to the present invention, it is possible to provide an environmentally friendly pressure-sensitive adhesive sheet having excellent ink adhesion.

BRIEF DESCRIPTION OF THE DRAWINGS It is a typical longitudinal cross-sectional view which shows suitable embodiment of the adhesive sheet of this invention.

Preferred embodiments of the present invention are described in detail below.
[1] Adhesive Sheet First, the adhesive sheet of the present invention will be described.
FIG. 1 is a schematic longitudinal sectional view showing a preferred embodiment of the pressure-sensitive adhesive sheet of the invention.

The pressure-sensitive adhesive sheet 10 of this embodiment includes a substrate 11 made of a material containing a polyester-based resin, and a printing coat layer 13 made of a material containing a high-acid-value polyester-based resin having an acid value of 10 mgKOH/g or more. and an adhesive layer 12 provided on the side of the substrate 11 opposite to the side coated with the printing coat layer 13 .

With such a configuration, it is possible to provide the pressure-sensitive adhesive sheet 10 that is environmentally friendly and has excellent ink adhesion.

On the other hand, satisfactory results cannot be obtained if the above conditions are not satisfied.
For example, if the acid value of the polyester-based resin constituting the printing coat layer is less than 10 mgKOH/g, the adhesion between the printing coat layer and the ink cannot be sufficiently excellent.

Further, even if the acid value of the resin material constituting the printing coat layer is 10 mgKOH/g or more, if the resin material is a resin material other than a polyester-based resin, the adhesion between the substrate and the printing coat layer can not be made sufficiently excellent, and as a result, the adhesiveness between the adhesive sheet and the ink cannot be made sufficiently excellent.

Further, even if the printing coat layer is composed of a material containing a high acid value polyester resin having an acid value of 10 mgKOH/g or more, the base material is composed of a material that does not contain a polyester resin. If this is the case, the adhesion between the base material and the printing coat layer cannot be sufficiently excellent, and as a result, the adhesion between the pressure-sensitive adhesive sheet and the ink cannot be sufficiently excellent.
In this specification, the term "sheet" includes the concept of film.

[1-1] Substrate The substrate 11 is a sheet-like member and has a function of supporting the printing coat layer 13 and the adhesive layer 12 . Further, as described above, the base material 11 is made of a material containing a polyester-based resin.

The polyester-based resin may be a polymer compound having a plurality of ester bonds in the main chain. For example, a polyhydric alcohol compound such as a diol compound and a polycarboxylic acid component such as a dicarboxylic acid component are In addition to compounds having a polycondensed structure, compounds having a polycondensed structure of monomer components having a hydroxyl group and a carboxylic acid in the molecule are also included.

Various resin materials having an ester bond in the main chain can be used as the polyester resin constituting the base material 11. At least one selected from the group consisting of polyethylene terephthalate, polybutylene succinate and polylactic acid can be used. Seeds are preferred.

Thereby, the adhesion between the substrate 11 and the printing coat layer 13 can be improved, and as a result, the adhesion between the adhesive sheet 10 and the ink can be improved. Among them, polylactic acid and polybutylene succinate are biodegradable and can reduce the overall environmental load from the production of the pressure-sensitive adhesive sheet 10 to its disposal.

The base material 11 may contain other resin materials in addition to the polyester-based resin.
Examples of resin materials other than the polyester-based resin contained in the base material 11 include polyolefin-based resins such as polyethylene, polypropylene, and ethylene/propylene copolymers; acetate resins; acrylonitrile-butadiene-styrene copolymer (ABS) resins; Polystyrene, polyvinyl chloride, polyamide, polyimide, polycarbonate, cellulose acetate and the like can be mentioned, and one or more selected from these can be used in combination.

Moreover, the material constituting the base material 11 may contain various additives as necessary.

Examples of additives include plasticizers, stabilizers, colorants, fillers, flame retardants, and the like.

As the stabilizer, for example, a barium-zinc-based (Ba--Zn-based) or calcium-zinc-based (Ca--Zn-based) stabilizer can be used.
As the coloring agent, for example, an organic pigment, an inorganic pigment, a dye, or the like can be used.

The base material 11 may be composed of a material containing a polyester-based resin at least in the portion that contacts the printing coat layer 13, and may have a portion that does not contain a polyester-based resin. It is preferably made of a material containing resin.

The content of the polyester resin (in particular, the preferred polyester resin described above) in the substrate 11 is preferably 40% by mass or more, more preferably 50% by mass or more, and 80% by mass or more. is more preferable.

The thickness of the base material 11 is preferably 10 μm or more and 500 μm or less, more preferably 15 μm or more and 300 μm or less.

Thereby, the rigidity, flexibility, durability, etc. of the adhesive sheet 10 as a whole can be made more suitable, and the ease of handling of the adhesive sheet 10 can be made excellent. More specifically, for example, the workability when forming a printed layer on the adhesive sheet 10 (for example, the difficulty of causing poor conveyance of the adhesive sheet 10), and the work of attaching the adhesive sheet 10 to the adherend. Efficiency can be improved. It is also advantageous from the standpoint of production cost and weight reduction of the adhesive sheet 10 .

[1-2] Printing Coat Layer The printing coat layer 13 is a portion where a printed portion is formed by applying ink.

The printing coat layer 13 is made of a material containing a high acid value polyester resin having an acid value of 10 mgKOH/g or more.

The acid value of the high acid value polyester resin that constitutes the printing coat layer 13 may be 10 mgKOH/g or more, preferably 15 mgKOH/g or more and 100 mgKOH/g or less, and more preferably 20 mgKOH/g or more and 90 mgKOH/g. It is more preferably 30 mgKOH/g or more and 80 mgKOH/g or less.
As a result, the above-described effects of the present invention are exhibited more remarkably.

The glass transition temperature of the high-acid-value polyester resin constituting the printing coat layer 13 is preferably 20°C or higher and 85°C or lower, more preferably 30°C or higher and 80°C or lower, and 40°C or higher and 70°C. More preferably:

As a result, the heat resistance and durability of the pressure-sensitive adhesive sheet 10 can be sufficiently improved, and the adhesion between the printing coat layer 13 and the substrate 11 can be further improved.

The weight-average molecular weight of the high acid value polyester resin that constitutes the printing coat layer 13 is preferably 1,000 or more and 70,000 or less, and more preferably 1,500 or more and 30,000 or less. ,000 or more and 10,000 or less.

As a result, the heat resistance and durability of the pressure-sensitive adhesive sheet 10 can be sufficiently improved, and the adhesion between the printing coat layer 13 and the ink can be further improved.

The printing coat layer 13 may contain other resin materials in addition to the high acid value polyester resin.

Examples of resin materials other than the high acid value polyester resin contained in the printing coat layer 13 include polyester resins having an acid value of less than 10 mgKOH/g, polyurethane resins, polyethylene, polypropylene, and ethylene/propylene copolymers. Polyolefin resins such as; acetate resins, acrylonitrile-butadiene-styrene copolymer (ABS) resins, polystyrene, polyvinyl chloride, polyamides, polyimides, polycarbonates, cellulose acetate, etc., and one or two selected from these The above can be used in combination. Among them, it is preferable to use high acid value materials such as high acid value polyurethane resins, high acid value polyolefin resins, and high acid value acrylic resins.

Above all, it is more preferable that the printing coat layer 13 is made of a material containing a high acid value polyester resin and a high acid value polyurethane resin having an acid value of 15 mgKOH/g or more.

When the printing coat layer 13 is made of a material containing a high acid value polyester resin and a polyurethane resin, the acid value of the polyurethane resin is preferably 15 mgKOH/g or more, but 18 mgKOH/g. more preferably 50 mgKOH/g or less, and even more preferably 23 mgKOH/g or more and 40 mgKOH/g or less.
Thereby, the effect mentioned above is exhibited more notably.

When the printing coat layer 13 is composed of a material containing a high acid value polyurethane resin together with a high acid value polyester resin, the high acid value polyester resin and the high acid value polyurethane resin in the printing coat layer 13 The content ratio with the resin is preferably 30:70 or more and 99:1 or less, more preferably 40:60 or more and 98:2 or less, and 45:55 or more and 90:10 or less, in terms of mass ratio. is more preferable.
Thereby, the effect mentioned above is exhibited more notably.

In addition, the material forming the printing coat layer 13 may contain various additives as necessary.

Examples of additives include plasticizers, stabilizers, colorants, fillers, flame retardants, and the like.

As the stabilizer, for example, a barium-zinc-based (Ba--Zn-based) or calcium-zinc-based (Ca--Zn-based) stabilizer can be used.
As the coloring agent, for example, an organic pigment, an inorganic pigment, a dye, or the like can be used.

The content of the high acid value polyester resin in the printing coat layer 13 is preferably 40% by mass or more, more preferably 50% by mass or more, and further preferably 60% by mass or more. preferable.

The thickness of the printing coat layer 13 is preferably 0.1 μm or more and 50 μm or less, more preferably 1 μm or more and 25 μm or less.

Thereby, the adhesion between the ink and the printing coat layer 13 and the adhesion between the substrate 11 and the printing coat layer 13 can be made more excellent.

The printing coat layer 13 is preferably formed by coating the substrate 11 with a water-based composition containing a high acid value polyester resin and water.

Thereby, the environmental load in the manufacturing process of the pressure-sensitive adhesive sheet 10 can be reduced. Moreover, since the high acid value polyester resin as described above has excellent affinity with water, it is possible to further improve the coatability of the composition containing the high acid value polyester resin. Furthermore, deformation of the base material 11 can be suppressed even when the coating is applied to the base material 11 made of a biodegradable material with low solvent resistance. A method for manufacturing the adhesive sheet 10 will be detailed later.

[1-3] Adhesive Layer The adhesive layer 12 has a function of exhibiting adhesive strength to an adherend.

The adhesive layer 12 may be composed of a material containing an adhesive, and the adhesive is not particularly limited, but is preferably at least one of a biomass-based adhesive and an emulsion-type adhesive.
Thereby, the environmental load of the adhesive sheet 10 can be made smaller.

An emulsion-type adhesive is an adhesive formed using an emulsion adhesive composition containing an adhesive component or a precursor thereof as a dispersoid. Usually, the emulsion-type adhesive itself constituting the adhesive layer 12 hardly contains the dispersion medium component of the adhesive composition, and even if it contains the dispersion medium component of the adhesive composition, the The component does not function as a dispersion medium.

The adhesive composition is preferably an aqueous emulsion containing an acrylic copolymer.

Emulsion-type adhesives include, for example, (meth)acrylic acid alkyl esters containing alkyl groups having 4 to 12 carbon atoms, carboxyl group-containing unsaturated monomers, carbonyl group-containing unsaturated monomers, and, if necessary, Depending on the situation, it can be obtained by emulsion polymerization of a monomer mixture containing other unsaturated monomers. In this specification, "(meth)acrylic acid" is a concept including both "acrylic acid" and "methacrylic acid". The same applies to "(meth)acrylate", "(meth)acrylo", and "(meth)allyl" described later.

The (meth)acrylic acid alkyl ester containing an alkyl group having 4 to 12 carbon atoms is not particularly limited, but examples include n-butyl (meth)acrylate, isobutyl (meth)acrylate, and n-hexyl (meth)acrylate. , 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate ) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, isoundecyl (meth) acrylate, dodecyl (meth) acrylate, isododecyl (meth) acrylate, etc., and a combination of one or more selected from these Among them, n-butyl (meth)acrylate and 2-ethylhexyl acrylate are preferred.

The carboxyl group-containing unsaturated monomer is not particularly limited, but includes, for example, acrylic acid, acrylic acid dimer, methacrylic acid, crotonic acid, itaconic acid, maleic acid, etc., and one or two selected from these. Although more than one species can be used in combination, acrylic acid and methacrylic acid are preferred.

The carbonyl group-containing unsaturated monomer is not particularly limited, but includes, for example, diacetone acrylamide, 2-(acetoacetoxy)ethyl (meth)acrylate, allylacetoacetate, etc., and one or Two or more kinds can be used in combination, and among them, diacetone acrylamide is preferable.

Furthermore, other unsaturated monomers are not particularly limited, but for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate and the like having 1 or more carbon atoms Alkyl (meth)acrylates having an alkyl group of 3 or less, alkyl (meth)acrylates having an alkyl group of 13 or more carbon atoms, such as tridecyl (meth)acrylate, isotridecyl (meth)acrylate, tetradecyl (meth)acrylate, etc. Ester, dimethylaminoethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl acetate , vinyl propionate, vinyl chloride, alkyl vinyl ether, and the like.

As unsaturated monomers, in addition to the above, functional group-containing unsaturated monomers such as hydroxyl group-containing unsaturated monomers, epoxy group-containing unsaturated monomers, alkoxysilyl group-containing unsaturated monomers , an unsaturated monomer containing an amide group or a methylol group, a polyfunctional unsaturated monomer, or the like may be used.

Examples of hydroxyl group-containing unsaturated monomers include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.

Examples of epoxy group-containing unsaturated monomers include glycidyl (meth)acrylate and allyl glycidyl ether.

Examples of alkoxysilyl group-containing unsaturated monomers include (meth)acryloxyethyltrimethoxysilane, (meth)acryloxyethyltriethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxyethyltrimethoxysilane, ) acryloxypropyltriethoxysilane, γ-(meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropyldimethylmethoxysilane, γ-(meth)acryloxypropylmethyldiethoxysilane, γ-(meth) Acryloxypropyldimethylethoxysilane, γ-(meth)acryloxypropyltrichlorosilane, γ-(meth)acryloxypropylmethyldichlorosilane, γ-(meth)acryloxypropyldimethylchlorosilane, γ-(meth)acryloxypropyltri propioxysilane, γ-(meth)acryloxypropylmethyldipropioxysilane, γ-(meth)acryloxypropyltributoxysilane, (meth)acryloxybutyltrimethoxysilane, (meth)acryloxypentyltrimethoxysilane, (meth)acryloxyhexyltrimethoxysilane, (meth)acryloxyhexyltriethoxysilane, (meth)acryloxyoctyltrimethoxysilane, (meth)acryloxydecyltrimethoxysilane, (meth)acryloxidedecyltrimethoxysilane, (Meth)acryloxyoctadecyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripoloxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinylmethyldipropoxysilane and the like.

Examples of unsaturated monomers containing an amide group or a methylol group include acrylamide, methacrylamide, N-methylolacrylamide, butoxy N-methylolacrylamide and the like.

Examples of polyfunctional unsaturated monomers include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate. ) acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth) ) acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri( meth)acrylate, tetramethylolmethane tetra(meth)acrylate, glycerin methacrylate acrylate, tris(meth)acryloyloxyphosphate, glycerin di(meth)acrylate, diallyl terephthalate, tetraallyloxyethane, divinylbenzene, tri(meth)allyl isocyanate nurate and the like.

The average particle size of the emulsion type adhesive of the adhesive layer 12 is preferably 80 nm or more and 1000 nm or less, more preferably 200 nm or more and 800 nm or less, and even more preferably 300 nm or more and 600 nm or less. As used herein, the term "average particle size" refers to a volume-based average particle size.

A biomass-based adhesive is an adhesive containing plant-derived components. Plant-derived components include polymers obtained by polymerizing acrylic acid produced from plant-derived alcohols, and tackifying resins selected from rosin resins and terpene resins.

Moreover, various additives may be contained in the material constituting the pressure-sensitive adhesive layer 12 as necessary.

Examples of additives include plasticizers, stabilizers, colorants, fillers, flame retardants, and the like.

As the stabilizer, for example, a barium-zinc-based (Ba--Zn-based) or calcium-zinc-based (Ca--Zn-based) stabilizer can be used.
As the coloring agent, for example, an organic pigment, an inorganic pigment, a dye, or the like can be used.

The content of the adhesive in the adhesive layer 12 is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

The thickness of the adhesive layer 12 is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less.

As a result, the ease of handling of the adhesive sheet 10, such as ease of attachment when the adhesive sheet 10 is attached to an adherend, and the adhesion of the adhesive sheet 10 to the adherend can be further improved. can.

[1-4] Release Liner The surface layer of the adhesive layer 12 of the unused adhesive sheet 10 is preferably covered with a release liner 20 as shown in FIG.

As a result, the pressure-sensitive adhesive layer 12 before being attached to the adherend can be suitably protected, and the unused pressure-sensitive adhesive sheet 10 can be easily handled. For example, when printing on the adhesive sheet 10, it is possible to effectively prevent the adhesive sheet 10 from adhering to an unintended place.

As the release liner 20, for example, one obtained by coating one surface of a paper substrate with polyethylene and coating the surface of the polyethylene coating layer with a release agent such as silicone can be used. The release liner 20 is not limited to this, and for example, a resin film may be used.

[1-5] Other Configurations The adhesive sheet 10 may have configurations other than those described above. For example, at least one intermediate layer may be provided between the substrate 11 and the adhesive layer 12 .

However, the adhesive sheet 10 preferably has a structure in which no anchor coat layer is provided between the substrate 11 and the printing coat layer 13 .

Thus, in the present invention, the adhesion between the substrate 11 and the printing coat layer 13 can be made sufficiently excellent without providing an anchor coat layer. Moreover, by not providing an anchor coat layer, the productivity of the adhesive sheet 10 can be further improved, and the environmental impact of the adhesive sheet 10 can be further reduced.

[2] Method for producing adhesive sheet Next, a method for producing an adhesive sheet will be described.

The pressure-sensitive adhesive sheet 10 is produced by forming a pressure-sensitive adhesive layer 12 on one side of the substrate 11 and forming a printing coat layer 13 on the other side of the substrate 11. It can be manufactured by a method having a forming step.

The order of the pressure-sensitive adhesive layer forming step and the printing coat layer forming step is not particularly limited. That is, the printing coat layer forming step may be performed after the adhesive layer forming step, or the adhesive layer forming step may be performed after the printing coat layer forming step.

The pressure-sensitive adhesive layer forming step may be performed, for example, by applying a pressure-sensitive adhesive composition onto the substrate 11 . When performing the adhesive layer forming step by such a method, after applying the adhesive composition to the base material 11, for example, by conveying the base material 11 to which the adhesive composition has been applied to a drying oven, A process for drying the pressure-sensitive adhesive composition may be performed. Further, when the pressure-sensitive adhesive layer forming step is performed by such a method, it is preferable to perform a covering step of covering the surface of the pressure-sensitive adhesive layer 12 with the release liner 20 after the pressure-sensitive adhesive layer forming step.

Alternatively, the pressure-sensitive adhesive layer forming step may be performed by applying the pressure-sensitive adhesive composition onto the release liner 20 and then transferring it to the substrate 11 . When the pressure-sensitive adhesive layer forming step is performed by such a method, the pressure-sensitive adhesive composition is applied at a timing after application of the pressure-sensitive adhesive composition to the release liner 20 and before transfer to the substrate 11, for example. The adhesive composition may be dried by, for example, transporting the release liner 20 to a drying oven.

As a coating method of the pressure-sensitive adhesive composition (coating method to the base material 11 or the release liner 20), for example, a knife coater, a gravure coater, a bar coater, or the like can be employed.

The printing coat layer forming step may be performed by, for example, applying a printing coat layer forming composition onto the substrate 11 . When the printing coat layer forming step is performed by such a method, after applying the printing coat layer forming composition to the substrate 11, for example, the substrate 11 to which the printing coat layer forming composition has been applied is The composition for forming a coating layer for printing may be dried by, for example, transporting it to a drying oven.

In particular, the printing coat layer 13 is preferably formed by coating the substrate 11 with a water-based composition containing a high acid value polyester resin and water.

Thereby, the environmental load in the manufacturing process of the pressure-sensitive adhesive sheet 10 can be reduced. In addition, since the high acid value polyester resin as described above has excellent affinity with water, it is possible to improve the coatability of the composition containing the high acid value polyester resin, and the adhesion The productivity of the sheet 10 can be improved.

A knife coater, a gravure coater, a bar coater, or the like can be employed as a coating method of the composition for forming a coating layer for printing.

[3] Printed Matter Next, the printed matter will be described.

The printed matter according to the present invention is produced by applying ink to the printing coat layer 13 of the adhesive sheet 10 according to the present invention described above to form a printed portion.
Such a printed matter is environmentally friendly and has excellent adhesion of the printed portion.

Although the ink used for forming the printed portion is not particularly limited, for example, a water-based ink containing water as a main solvent, an ultraviolet curable ink, or the like can be preferably used.

The formation pattern of the printing portion is not particularly limited, and for example, it may be formed by applying ink to only a part of the printing coat layer 13, or may be formed by applying ink to the entire printing coat layer 13. It may be formed by imparting.
Moreover, you may use multiple types of ink for formation of a printing part.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these.

Moreover, the pressure-sensitive adhesive sheet of the present invention may be produced by any method, and is not limited to those produced by the methods described in the above embodiments.

Hereinafter, the present invention will be described in detail based on specific examples, but the present invention is not limited to these.

[4] Production of adhesive sheet (Example 1)
First, a substrate made of polyethylene terephthalate and having a thickness of 50 μm was prepared.

A composition for forming a coating layer for printing is applied to one surface of the substrate with a bar coater, and then heated at 90° C. for 1 minute using a hot air dryer to form a coating layer for printing. bottom. As the composition for forming a coating layer for printing, a composition comprising a mixture of 100 parts by mass of a high acid value polyester resin, which is a polyester resin having an acid value of 50 mgKOH/g, and 400 parts by mass of water was used. . The thickness of the printing coat layer thus formed was 1.0 μm.

On the other hand, a pressure-sensitive adhesive layer composed of an acrylic emulsion-type pressure-sensitive adhesive was formed on a release liner composed of glassine paper that had been subjected to release treatment with a silicone resin. The adhesive layer is formed on the release liner by coating the adhesive composition Olivine BPW 6441 (manufactured by Toyochem) with a knife coater, and then using a hot air dryer to heat at 90°C for 1 minute. I went by.

The pressure-sensitive adhesive layer formed on the release liner in this way is brought into contact with the surface of the substrate on which the printing coat layer is formed, opposite to the surface on which the printing coat layer is formed, thereby forming the printing coat. A pressure-sensitive adhesive sheet was obtained in which a layer, a substrate, a pressure-sensitive adhesive layer and a release liner were laminated in this order. The adhesive layer of the adhesive sheet had a thickness of 20 μm.

(Examples 2 to 9)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the configuration of each part was as shown in Table 1.

(Comparative Examples 1 to 7)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the configuration of each part was as shown in Table 1.

Table 1 summarizes the conditions of the pressure-sensitive adhesive sheets of the above Examples and Comparative Examples. In Table 1, polyethylene terephthalate is "PET", polylactic acid is "PLA", polybutylene succinate is "PBS", polypropylene is "PP", and Olivine BPW 6441 (manufactured by Toyochem Co., Ltd.) is an emulsion type adhesive. The adhesive is indicated as "EM", and the adhesive by Olivine BPS 6554 (manufactured by Toyochem Co., Ltd.), which is a biomass adhesive, is indicated as "BM". Further, in each of the above examples, a water-based composition was used for forming the printing coat layer.

[5] Evaluation The pressure-sensitive adhesive sheets of each of the examples and comparative examples were evaluated as follows.

[5-1] Evaluation of printability For the pressure-sensitive adhesive sheets of each of the above examples and comparative examples, ultraviolet curable ink (T&K TOKA, trade name “BESTCURE UV161 Black S”) was used on the surface of the printing coat layer. , A printing machine (manufactured by Akira Seisakusho Co., Ltd., trade name "RI Tester") is used to print a predetermined pattern, and the ink is cured by irradiating ultraviolet rays with a high-pressure mercury lamp to form a printed layer with a thickness of 0.5 μm. , got a print. The formed printed layer was subjected to an adhesive tape peeling test according to JIS K 5600-5-6 (cross-cut method), and printability was evaluated according to the following criteria.

Good: The number of squares in which the printed layer remains after the adhesive tape peeling test is 80 or more per 100 squares.
x: The number of squares in which the printed layer remains after the adhesive tape peeling test is less than 80 per 100 squares.
These results are summarized in Table 2.

As is clear from Table 2, it was confirmed that in the pressure-sensitive adhesive sheet of the present invention, the printed layer satisfactorily remained, and the adhesiveness to the ink was excellent. In addition, the pressure-sensitive adhesive sheet of the present invention effectively prevented deformation of the substrate. On the other hand, in each comparative example, satisfactory results were not obtained.

Printed matter in the same manner as in [5-1] above, except that water-based ink (manufactured by Toyo Ink Co., Ltd., trade name "Aquariona") was used instead of UV-curable ink, and drying was performed at 70 ° C. instead of UV irradiation. was produced and the same evaluation was performed, and the results with the same tendency were obtained.

DESCRIPTION OF SYMBOLS 10... Adhesive sheet 11... Base material 12... Adhesive layer 13... Coat layer for printing 20... Release liner

Claims (6)

a substrate made of a material containing a polyester-based resin;
a printing coat layer made of a material containing a high acid value polyester resin having an acid value of 10 mgKOH/g or more;
a pressure-sensitive adhesive layer provided on the surface of the base material opposite to the surface coated with the printing coat layer;
A pressure-sensitive adhesive sheet comprising: 2. The pressure-sensitive adhesive sheet according to claim 1, wherein the base material comprises a material containing at least one selected from the group consisting of polyethylene terephthalate, polybutylene succinate and polylactic acid. The adhesive sheet according to claim 1 or 2, wherein the high acid value polyester resin has a glass transition temperature of 20°C or higher and 85°C or lower. 4. The printing coat layer is formed by applying a water-based composition containing the high acid value polyester resin and water onto the substrate. The adhesive sheet described in . 5. The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein no anchor coat layer is provided between the substrate and the printing coat layer. The pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive layer contains at least one of a biomass-based pressure-sensitive adhesive and an emulsion-type pressure-sensitive adhesive.

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