Adhesive sheet and method for manufacturing the same

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 polyolefin resin; a coat layer for printing constituted of a material containing a high acid value polyurethane resin having an acid value of 15 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 of polypropylene and polyethylene. The high acid value polyurethane resin preferably has a glass transition temperature of 20°C or higher and 85°C or lower.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pressure-sensitive adhesive sheet. and a method for manufacturing an adhesive sheet Regarding. [Background technology]

[0002] BACKGROUND ART Pressure-sensitive adhesive sheets are known which are used for various printing processes and which are attached to an adherend after printing.

[0003] In such pressure-sensitive adhesive sheets, a coating layer for printing is provided to improve adhesion to ink.

[0004] Conventionally, such a printing coating layer has been formed using a solvent-based coating liquid (see, for example, Patent Document 1).

[0005] On the other hand, in order to respond to recent environmental issues, there is a demand to use environmentally friendly materials in the manufacturing processes of various products.

[0006] In order to meet such demands, it has been considered to form a printing coating layer using an aqueous coating liquid in the above-mentioned pressure-sensitive adhesive sheet, but in this case, there is a problem in that the adhesion of the ink to the printing coating layer cannot be made sufficiently excellent. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6030843 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide an environmentally friendly pressure-sensitive adhesive sheet that has excellent ink adhesion. Also, to provide a method for producing an environmentally friendly adhesive sheet that has excellent ink adhesion. is located. [Means for solving the problem]

[0009] Such objectives are as follows: (1) 7 This is achieved by the present invention described in (1) a substrate made of a material containing a polyolefin resin; High acid value polyurethane resin with an acid value of 15 mg KOH / g or more , and high acid value polyester resins with an acid value of 10 mgKOH / g or more A printing coating layer made of a material containing a pressure-sensitive adhesive layer provided on the surface of the substrate opposite to the surface coated with the printing coating layer; Equipped with 、 The ratio of the content of the high acid value polyurethane resin to the content of the high acid value polyester resin in the printing coating layer is 30:70 or more and 99:1 or less in mass ratio. A pressure-sensitive adhesive sheet characterized by:

[0010] (2) The pressure-sensitive adhesive sheet according to (1) above, wherein the substrate is made of a material containing at least one of polypropylene and polyethylene.

[0011] (3) The pressure-sensitive adhesive sheet according to (1) or (2) above, wherein the high acid value polyurethane resin has a glass transition temperature of 20°C or higher and 85°C or lower.

[0013] ( 4 ) The above (1) to (3) in which an anchor coat layer is not provided between the substrate and the printing coat layer. 3 ) The pressure-sensitive adhesive sheet according to any one of the preceding claims.

[0014] ( 5 ) The adhesive layer contains at least one of a biomass-based adhesive and an emulsion-type adhesive, as described in (1) to ( 4 ) The pressure-sensitive adhesive sheet according to any one of the preceding claims. (6) a pressure-sensitive adhesive layer forming step of forming a pressure-sensitive adhesive layer on one side of a substrate made of a material containing a polyolefin-based resin; a printing coating layer forming step of forming a printing coating layer on the other surface of the substrate, the printing coating layer including a high acid value polyurethane resin having an acid value of 15 mgKOH / g or more and a high acid value polyester resin having an acid value of 10 mgKOH / g or more; A method for producing an adhesive sheet, characterized in that the ratio of the content of the high acid value polyurethane resin to the content of the high acid value polyester resin in the printing coating layer is 30:70 or more and 99:1 or less, in mass ratio. (7) The method for producing a pressure-sensitive adhesive sheet described in (6) above, wherein the printing coating layer forming process is carried out by applying an aqueous composition containing the high acid value polyurethane resin, the high acid value polyester resin, and water onto the substrate. [Effects of the Invention]

[0015] According to the present invention, an environmentally friendly pressure-sensitive adhesive sheet having excellent ink adhesion is provided. Also, to provide a method for producing an environmentally friendly adhesive sheet that has excellent ink adhesion. can be done. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic longitudinal sectional view showing a preferred embodiment of the pressure-sensitive adhesive sheet of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Preferred embodiments of the present invention will be described in detail below. [1] Adhesive sheet First, the pressure-sensitive 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 present invention.

[0018] The adhesive sheet 10 of this embodiment comprises a substrate 11 made of a material containing a polyolefin-based resin, a printing coating layer 13 made of a material containing a high-acid-value polyurethane-based resin having an acid value of 15 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 coating layer 13.

[0019] With this configuration, it is possible to provide an environmentally friendly pressure-sensitive adhesive sheet 10 that has excellent ink adhesion.

[0020] On the other hand, if the above conditions are not met, satisfactory results will not be obtained. For example, if the acid value of the polyurethane resin constituting the printing coating layer is less than 15 mgKOH / g, the adhesion between the printing coating layer and ink cannot be made sufficiently excellent.

[0021] Furthermore, even if the acid value of the resin material constituting the printing coating layer is 15 mgKOH / g or more, if the resin material is a resin material other than a polyurethane-based resin, the adhesion between the substrate and the printing coating layer cannot be made sufficiently excellent, and as a result, the adhesion between the adhesive sheet and the ink cannot be made sufficiently excellent.

[0022] Furthermore, even if a printing coating layer is provided that is made of a material containing a high acid value polyurethane resin with an acid value of 15 mgKOH / g or more, if the substrate is made of a material that does not contain a polyolefin resin, the adhesion between the substrate and the printing coating layer cannot be made sufficiently excellent, and as a result, the adhesion between the adhesive sheet and the ink cannot be made sufficiently excellent. In this specification, the term "sheet" includes the concept of film.

[0023] [1-1] Base material The substrate 11 is a sheet-like member, and has the function of supporting the printing coating layer 13 and the adhesive layer 12. As described above, the substrate 11 is made of a material containing a polyolefin resin.

[0024] Polyolefin resins are polymeric compounds having a chemical structure obtained by polymerizing olefins having carbon-carbon double bonds as monomers.

[0025] Such polyolefin resins are generally characterized by excellent flexibility and transparency, and therefore, by forming substrate 11 from a material containing polyolefin resin, it is possible to obtain pressure-sensitive adhesive sheet 10 that has excellent conformability to curved surfaces and excellent visibility of the underlying surface.

[0026] Examples of polyolefin resins constituting the substrate 11 include polyethylene (PE), polypropylene (PP), polybutene (PB), ethylene-propylene copolymer, olefin elastomer (TPO), ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), olefin terpolymers such as ethylene-propylene-(5-ethylidene-2-norbornene), and the like. One or a combination of two or more selected from these can be used, but at least one of polypropylene and polyethylene is preferred.

[0027] This makes it possible to improve the adhesion between the substrate 11 and the printing coating layer 13, and as a result, improve the adhesion between the pressure-sensitive adhesive sheet 10 and the ink.

[0028] The substrate 11 may contain other resin materials in addition to the polyolefin resin. Examples of resin materials other than polyolefin-based resins contained in the substrate 11 include polyester-based resins such as polyethylene terephthalate, polybutylene succinate, and polylactic acid; acetate resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, polystyrene, polyvinyl chloride, polyamide, polyimide, polycarbonate, and cellulose acetate, and one or more selected from these may be used in combination.

[0029] Furthermore, the material constituting the substrate 11 may contain various additives as needed.

[0030] Examples of additives include plasticizers, stabilizers, colorants, fillers, and flame retardants.

[0031] As the stabilizer, for example, a barium zinc (Ba-Zn) stabilizer or a calcium zinc (Ca-Zn) stabilizer can be used. As the colorant, for example, organic pigments, inorganic pigments, dyes, etc. can be used.

[0032] The substrate 11 may have at least the portion that comes into contact with the printing coating layer 13 made of a material containing a polyolefin-based resin, and may have portions that do not contain a polyolefin-based resin, but it is preferable that the entire substrate be made of a material that contains a polyolefin-based resin.

[0033] The content of polyolefin resin (particularly the above-mentioned preferred polyolefin resin) in the substrate 11 is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 80% by mass or more.

[0034] The thickness of the substrate 11 is preferably 10 μm or more and 500 μm or less, and more preferably 15 μm or more and 300 μm or less.

[0035] This makes it possible to improve the rigidity, flexibility, durability, etc. of the adhesive sheet 10 as a whole, and to improve the ease of handling of the adhesive sheet 10. More specifically, for example, it is possible to improve the workability when forming a printing layer on the adhesive sheet 10 (for example, the reduced likelihood of transport problems of the adhesive sheet 10) and the work efficiency when adhering the adhesive sheet 10 to an adherend. This is also advantageous from the standpoint of the production cost, weight reduction, etc. of the adhesive sheet 10.

[0036] [1-2] Printing coating layer The printing coating layer 13 is a portion where a printed portion is formed by applying ink.

[0037] The printing coating layer 13 is made of a material containing a high acid value polyurethane resin having an acid value of 15 mgKOH / g or more.

[0038] The acid value of the high acid value polyurethane resin constituting the printing coating layer 13 may be 15 mgKOH / g or more, preferably 18 mgKOH / g or more and 50 mgKOH / g or less, more preferably 20 mgKOH / g or more and 45 mgKOH / g or less, and even more preferably 23 mgKOH / g or more and 40 mgKOH / g or less. This allows the effects of the present invention to be more pronounced.

[0039] The high acid value polyurethane resin may be any polymeric material having a urethane bond in the main chain, and may be, for example, any of various modified polyurethanes such as acrylic-modified polyurethane, ether-modified polyurethane, ester-ether-modified polyurethane, and silicone-modified polyurethane.

[0040] The glass transition temperature of the high acid value polyurethane resin constituting the printing coating layer 13 is preferably 20°C or higher and 85°C or lower, more preferably 23°C or higher and 60°C or lower, and even more preferably 25°C or higher and 50°C or lower.

[0041] This allows the adhesive sheet 10 to have sufficiently excellent heat resistance and durability, while also improving the adhesion between the printing coating layer 13 and the substrate 11 .

[0042] The weight average molecular weight of the high acid value polyurethane resin constituting the printing coating layer 13 is preferably 1,000 or more and 50,000 or less, and more preferably 3,000 or more and 30,000 or less.

[0043] This allows the adhesive sheet 10 to have sufficiently excellent heat resistance and durability, while also improving the adhesion between the printing coating layer 13 and ink.

[0044] The printing coating layer 13 may contain other resin materials in addition to the high acid value polyurethane resin.

[0045] Resin materials other than the high-acid-value polyurethane resin contained in the printing coating layer 13 include, for example, polyurethane resins with an acid value of less than 15 mgKOH / g, polyester resins, polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers, acetate resins, acrylonitrile-butadiene-styrene copolymer (ABS) resins, polystyrene, polyvinyl chloride, polyamide, polyimide, polycarbonate, and cellulose acetate, and one or more selected from these may be used in combination. Among these, it is preferable to use materials with high acid values, such as high-acid-value polyester resins, high-acid-value polyolefin resins, and high-acid-value acrylic resins.

[0046] Among these, it is more preferable that the printing coating layer 13 is made of a material containing a high acid value polyurethane resin and a high acid value polyester resin having an acid value of 30 mgKOH / g or more.

[0047] When the printing coating layer 13 is composed of a material containing a polyester resin together with a high acid value polyurethane resin, the acid value of the polyester resin is preferably 10 mgKOH / g or more, more preferably 15 mgKOH / g or more and 80 mgKOH / g or less, and even more preferably 30 mgKOH / g or more and 60 mgKOH / g or less. This makes the above-mentioned effects more pronounced.

[0048] When the printing coating layer 13 is composed of a material containing a high acid value polyurethane resin and a high acid value polyester resin, the ratio of the content of the high acid value polyurethane resin to the high acid value polyester resin in the printing coating layer 13 is preferably 30:70 or more and 99:1 or less, more preferably 40:60 or more and 98:2 or less, and even more preferably 45:55 or more and 90:10 or less, by mass. This makes the above-mentioned effects more pronounced.

[0049] Furthermore, the material constituting the printing coating layer 13 may contain various additives as required.

[0050] Examples of additives include plasticizers, stabilizers, colorants, fillers, and flame retardants.

[0051] As the stabilizer, for example, a barium zinc (Ba-Zn) stabilizer or a calcium zinc (Ca-Zn) stabilizer can be used. As the colorant, for example, organic pigments, inorganic pigments, dyes, etc. can be used.

[0052] The content of the high acid value polyurethane resin in the printing coating layer 13 is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more.

[0053] The thickness of the printing coating layer 13 is preferably 0.1 μm or more and 50 μm or less, and more preferably 1 μm or more and 25 μm or less.

[0054] This makes it possible to improve the adhesion between the ink and the printing coating layer 13, as well as the adhesion between the substrate 11 and the printing coating layer 13.

[0055] The printing coating layer 13 is preferably formed by applying an aqueous composition containing a high acid value polyurethane resin and water onto the substrate 11 .

[0056] This reduces the environmental impact of the manufacturing process of the pressure-sensitive adhesive sheet 10. Furthermore, because the high acid value polyurethane resin has excellent affinity with water, the coating properties of a composition containing the high acid value polyurethane resin can be improved. The manufacturing method of the pressure-sensitive adhesive sheet 10 will be described in detail later.

[0057] [1-3] Adhesive layer The pressure-sensitive adhesive layer 12 has the function of exerting adhesive strength to an adherend. The adhesive layer 12 may be made 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. This allows the pressure-sensitive adhesive sheet 10 to have a smaller environmental impact.

[0058] The emulsion-type pressure-sensitive adhesive is a pressure-sensitive adhesive formed using a pressure-sensitive adhesive composition that is an emulsion containing a pressure-sensitive adhesive component or its precursor as a dispersoid. Usually, the emulsion-type pressure-sensitive adhesive that constitutes the pressure-sensitive adhesive layer 12 itself contains almost no dispersion medium component of the pressure-sensitive adhesive composition, and even if it contains a dispersion medium component of the pressure-sensitive adhesive composition, the component does not function as a dispersion medium.

[0059] The pressure-sensitive adhesive composition is preferably an aqueous emulsion containing an acrylic copolymer.

[0060] The emulsion-type PSA can be obtained, for example, by emulsion polymerization of a monomer mixture containing a (meth)acrylic acid alkyl ester containing an alkyl group having from 4 to 12 carbon atoms, a carboxyl group-containing unsaturated monomer, a carbonyl group-containing unsaturated monomer, and, if necessary, other unsaturated monomers. In this specification, the term "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid." The same applies to "(meth)acrylate," "(meth)acrylo," and "(meth)allyl," which will be described later.

[0061] The (meth)acrylic acid alkyl ester containing an alkyl group having from 4 to 12 carbon atoms is not particularly limited, and examples thereof include n-butyl(meth)acrylate, isobutyl(meth)acrylate, 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, isodecyl(meth)acrylate, undecyl(meth)acrylate, isoundecyl(meth)acrylate, dodecyl(meth)acrylate, and isododecyl(meth)acrylate. One or a combination of two or more selected from these can be used, and among these, n-butyl(meth)acrylate and 2-ethylhexyl acrylate are preferred.

[0062] The carboxyl group-containing unsaturated monomer is not particularly limited, but examples thereof include acrylic acid, acrylic acid dimer, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and the like. One or a combination of two or more selected from these may be used, with acrylic acid and methacrylic acid being particularly preferred.

[0063] The carbonyl group-containing unsaturated monomer is not particularly limited, but examples thereof include diacetone acrylamide, 2-(acetoacetoxy)ethyl (meth)acrylate, and allyl acetoacetate. One or a combination of two or more selected from these may be used, and among these, diacetone acrylamide is preferred.

[0064] Furthermore, other unsaturated monomers are not particularly limited, but examples thereof include (meth)acrylic acid alkyl esters having an alkyl group of 1 to 3 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate; (meth)acrylic acid alkyl esters having an alkyl group of 13 or more carbon atoms, such as tridecyl (meth)acrylate, isotridecyl (meth)acrylate, and tetradecyl (meth)acrylate; 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, and alkyl vinyl ethers.

[0065] In addition to the above, the unsaturated monomer may also be a functional group-containing unsaturated monomer, such as a hydroxyl group-containing unsaturated monomer, an epoxy group-containing unsaturated monomer, an alkoxysilyl group-containing unsaturated monomer, an amide group- or methylol group-containing unsaturated monomer, or a polyfunctional unsaturated monomer.

[0066] Examples of the hydroxyl group-containing unsaturated monomer include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.

[0067] Examples of the epoxy group-containing unsaturated monomer include glycidyl (meth)acrylate and allyl glycidyl ether.

[0068] Examples of the alkoxysilyl group-containing unsaturated monomer include (meth)acryloxyethyltrimethoxysilane, (meth)acryloxyethyltriethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, γ-(meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropyldimethylmethoxysilane, γ-(meth)acryloxypropylmethyldiethoxysilane, γ-(meth)acryloxypropyldimethylethoxysilane, γ-(meth)acryloxypropyltrichlorosilane, γ-(meth)acryloxypropylmethyldichlorosilane, γ-(meth)acryloxypropyldimethylchlorosilane, and γ-(meth)acryloxypropyltripropyloxysilane. , γ-(meth)acryloxypropylmethyldipropoxysilane, γ-(meth)acryloxypropyltributoxysilane, (meth)acryloxybutyltrimethoxysilane, (meth)acryloxypentyltrimethoxysilane, (meth)acryloxyhexyltrimethoxysilane, (meth)acryloxyhexyltriethoxysilane, (meth)acryloxyoctyltrimethoxysilane, (meth)acryloxydecyltrimethoxysilane, (meth)acryloxydodecyltrimethoxysilane, (meth)acryloxyoctadecyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriporopoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinylmethyldipropoxysilane, and the like.

[0069] Examples of unsaturated monomers containing an amide group or a methylol group include acrylamide, methacrylamide, N-methylolacrylamide, and butoxy N-methylolacrylamide.

[0070] Examples of the polyfunctional unsaturated monomer 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, 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-hexyl Examples of the acrylates include sandiol 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, and tri(meth)allyl isocyanurate.

[0071] The average particle size of the emulsion-type pressure-sensitive adhesive in the pressure-sensitive 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. In this specification, the term "average particle size" refers to the average particle size on a volume basis.

[0072] Biomass-based adhesives are adhesives containing plant-derived components, such as polymers obtained by polymerizing acrylic acid produced from plant-derived alcohol, and tackifying resins selected from rosin resins and terpene resins.

[0073] Furthermore, the material constituting the pressure-sensitive adhesive layer 12 may contain various additives as needed.

[0074] Examples of additives include plasticizers, stabilizers, colorants, fillers, and flame retardants.

[0075] As the stabilizer, for example, a barium zinc (Ba-Zn) stabilizer or a calcium zinc (Ca-Zn) stabilizer can be used. As the colorant, for example, organic pigments, inorganic pigments, dyes, etc. can be used.

[0076] 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.

[0077] The thickness of the pressure-sensitive adhesive layer 12 is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.

[0078] This makes it possible to further improve the ease of handling of the adhesive sheet 10, such as the ease of application of the adhesive sheet 10 to an adherend, and the adhesiveness of the adhesive sheet 10 to an adherend.

[0079] [1-4] Release liner The surface of the adhesive layer 12 of an unused adhesive sheet 10 is preferably covered with a release liner 20 as shown in FIG.

[0080] This makes it possible to suitably protect the adhesive layer 12 before it is attached to the adherend, and also makes it easier to handle unused adhesive sheet 10. For example, when printing on adhesive sheet 10, it is possible to effectively prevent adhesive sheet 10 from adhering to undesired locations.

[0081] For example, a paper substrate coated on one side with polyethylene and a release agent such as silicone applied to the surface of the polyethylene coating can be used as the release liner 20. The release liner 20 is not limited to this, and for example, a resin film can also be used.

[0082] [1-5] Other configurations Pressure-sensitive adhesive sheet 10 may have a configuration other than those described above. For example, at least one intermediate layer may be provided between substrate 11 and pressure-sensitive adhesive layer 12.

[0083] However, it is preferable that the adhesive sheet 10 is configured such that no anchor coat layer is provided between the substrate 11 and the printing coat layer 13 .

[0084] Thus, in the present invention, even without providing an anchor coat layer, it is possible to achieve sufficiently excellent adhesion between the substrate 11 and the printing coat layer 13. Furthermore, by not providing an anchor coat layer, it is possible to further improve the productivity of the pressure-sensitive adhesive sheet 10 and further reduce the environmental impact of the pressure-sensitive adhesive sheet 10.

[0085] [2] Manufacturing method of adhesive sheet Next, a method for producing the pressure-sensitive adhesive sheet will be described.

[0086] The adhesive sheet 10 can be produced by a method including an adhesive layer forming step of forming an adhesive layer 12 on one side of the substrate 11, and a printing coating layer forming step of forming a printing coating layer 13 on the other side of the substrate 11.

[0087] The order of the pressure-sensitive adhesive layer-forming step and the printing coating layer-forming step is not particularly limited. That is, the printing coating layer-forming step may be performed after the pressure-sensitive adhesive layer-forming step, or the printing coating layer-forming step may be performed after the pressure-sensitive adhesive layer-forming step.

[0088] The pressure-sensitive adhesive layer forming step may be carried out, for example, by applying a pressure-sensitive adhesive composition onto the substrate 11. When the pressure-sensitive adhesive layer forming step is carried out in this manner, after applying the pressure-sensitive adhesive composition to the substrate 11, a treatment to dry the pressure-sensitive adhesive composition may be carried out, for example, by transporting the substrate 11 to which the pressure-sensitive adhesive composition has been applied into a drying oven. Furthermore, when the pressure-sensitive adhesive layer forming step is carried out in this manner, it is preferable to carry out a coating step in which the surface of the pressure-sensitive adhesive layer 12 is coated with a release liner 20 after the pressure-sensitive adhesive layer forming step.

[0089] Alternatively, the PSA layer forming step may be carried out by applying the PSA composition to the release liner 20 and then transferring it to the substrate 11. When the PSA layer forming step is carried out in this manner, after the PSA composition has been applied to the release liner 20 and before it is transferred to the substrate 11, a treatment to dry the PSA composition may be carried out, for example, by transporting the release liner 20 to which the PSA composition has been applied into a drying oven.

[0090] As a method for applying the pressure-sensitive adhesive composition (a method for applying the pressure-sensitive adhesive composition to the substrate 11 or the release liner 20), for example, a knife coater, a gravure coater, a bar coater, or the like can be used.

[0091] The printing coating layer forming step may be carried out, for example, by applying a printing coating layer forming composition onto the substrate 11. When the printing coating layer forming step is carried out in this manner, after applying the printing coating layer forming composition to the substrate 11, a process of drying the printing coating layer forming composition may be carried out, for example, by transporting the substrate 11 to which the printing coating layer forming composition has been applied, into a drying oven.

[0092] In particular, the printing coating layer 13 is preferably formed by applying an aqueous composition containing a high acid value polyurethane resin and water onto the substrate 11 .

[0093] This can reduce the environmental impact of the manufacturing process of the pressure-sensitive adhesive sheet 10. Furthermore, because the high acid value polyurethane resin as described above has excellent affinity for water, the coatability of a composition containing the high acid value polyurethane resin can be improved, and the productivity of the pressure-sensitive adhesive sheet 10 can be increased.

[0094] The composition for forming a coating layer for printing can be applied using, for example, a knife coater, a gravure coater, a bar coater, or the like.

[0095] [3] Printed matter Next, the printed matter will be described.

[0096] The printed matter according to the present invention is produced by applying ink to the printing coating layer 13 of the pressure-sensitive adhesive sheet 10 according to the present invention described above to form a printed portion. Such printed matter is environmentally friendly and has excellent adhesion of the printed area.

[0097] The ink used to form the printed portion is not particularly limited, but for example, water-based ink containing water as the main solvent, ultraviolet curable ink, etc. can be suitably used.

[0098] The pattern of the printed portion is not particularly limited, and may be formed, for example, by applying ink to only a portion of the printing coating layer 13, or by applying ink to the entire printing coating layer 13.

[0099] Furthermore, a plurality of types of ink may be used to form the printed portion. Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these.

[0100] Furthermore, 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-described embodiments. [Example]

[0101] The present invention will be described in detail below based on specific examples, but the present invention is not limited to these examples.

[0102] [4] Manufacturing of adhesive sheets Example 1 First, a substrate made of polypropylene and having a thickness of 50 μm was prepared.

[0103] A printing coating layer-forming composition was applied to one side of the substrate using a bar coater, and then heated at 70°C for 1 minute using a hot air dryer to form a printing coating layer. The printing coating layer-forming composition used was a mixture of 100 parts by mass of a high-acid-value polyurethane resin (a polyurethane resin with an acid value of 27 mgKOH / g) and 400 parts by mass of water. The printing coating layer thus formed had a thickness of 1.0 μm.

[0104] On the other hand, an adhesive layer composed of an acrylic emulsion adhesive was formed on a release liner composed of glassine paper that had been release-treated with a silicone resin. The adhesive layer was formed on the release liner by coating the adhesive composition Oribain BPW 6441 (manufactured by Toyochem Co., Ltd.) on the release liner using a knife coater, followed by heating at 90°C for 1 minute using a hot air dryer.

[0105] The adhesive layer thus formed on the release liner was brought into contact with the surface of the substrate on which the printing coating layer was formed, opposite the surface on which the printing coating layer was formed, to obtain an adhesive sheet having the printing coating layer, substrate, adhesive layer, and release liner laminated in this order. The thickness of the adhesive layer on the adhesive sheet was 20 μm.

[0106] 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.

[0107] (Comparative Examples 1 to 3) 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.

[0108] The conditions for the pressure-sensitive adhesive sheets of the above-mentioned Examples and Comparative Examples are summarized in Table 1. In Table 1, polyethylene is represented by "PE," polypropylene by "PP," polyethylene terephthalate by "PET," an emulsion-type pressure-sensitive adhesive, Oribain BPW 6441 (manufactured by Toyochem Co., Ltd.), is represented by "EM," and an adhesive, biomass-based pressure-sensitive adhesive, Oribain BPS 6554 (manufactured by Toyochem Co., Ltd.), is represented by "BM." In addition, in the above-mentioned Examples, an aqueous composition was used to form the printing coating layer.

[0109] [Table 1]

[0110] [5] Evaluation The pressure-sensitive adhesive sheets of the above-mentioned Examples and Comparative Examples were evaluated as follows. [5-1] Printability evaluation For the pressure-sensitive adhesive sheets of each of the Examples and Comparative Examples, a predetermined pattern was printed on the surface of the printing coating layer using an ultraviolet-curable ink (manufactured by T&K TOKA, product name "BESTCURE UV161 Sumi S") with a printing machine (manufactured by Akira Manufacturing, product name "RI Tester"), and the ink was cured by irradiating it with ultraviolet light from a high-pressure mercury lamp to form a printed layer with a film thickness of 0.5 μm, thereby obtaining a printed product. The formed printed layer was subjected to an adhesive tape peel test in accordance with JIS K 5600-5-6 (cross-cut method), and the printability was evaluated according to the following criteria.

[0111] Good: The number of squares in which the printed layer remains after the adhesive tape peeling test is 80 or more per 100 squares. △: The number of squares in which the printed layer remains after the adhesive tape peeling test is 50 or more and less than 80 per 100 squares. ×: The number of squares in which the printed layer remains after the adhesive tape peeling test is less than 50 out of 100 squares. These results are summarized in Table 2.

[0112] [Table 2]

[0113] As is clear from Table 2, the pressure-sensitive adhesive sheet of the present invention was confirmed to have excellent adhesion to ink, with the printed layer remaining in a favorable state. In contrast, the comparative examples did not provide satisfactory results.

[0114] Printed matter was produced and evaluated in the same manner as in [5-1] above, except that a water-based ink (manufactured by Toyo Ink Co., Ltd., trade name "Aquariona") was used instead of the UV-curable ink and drying was carried out at 70°C instead of UV irradiation. Similar results were obtained. [Explanation of symbols]

[0115] 10...Adhesive sheet 11...Base material 12...Adhesive layer 13...Printing coating layer 20...Release liner

Claims

1. a substrate made of a material containing a polyolefin resin; a printing coating layer made of a material containing a high acid value polyurethane resin having an acid value of 15 mgKOH / g or more and 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 substrate opposite to the surface coated with the printing coating layer; Equipped with A pressure-sensitive adhesive sheet characterized in that the ratio of the content of the high acid value polyurethane resin to the content of the high acid value polyester resin in the printing coating layer is 30:70 or more and 99:1 or less in mass ratio.

2. The pressure-sensitive adhesive sheet according to claim 1 , wherein the substrate is made of a material containing at least one of polypropylene and polyethylene.

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

4. The pressure-sensitive adhesive sheet according to claim 1 , wherein no anchor coat layer is provided between the substrate and the printing coat layer.

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

6. An adhesive layer forming step of forming an adhesive layer on one side of a substrate made of a material containing a polyolefin resin; a printing coating layer forming step of forming a printing coating layer on the other surface of the substrate, the printing coating layer including a high acid value polyurethane resin having an acid value of 15 mgKOH / g or more and a high acid value polyester resin having an acid value of 10 mgKOH / g or more; A method for producing a pressure-sensitive adhesive sheet, characterized in that the ratio of the content of the high acid value polyurethane resin to the content of the high acid value polyester resin in the printing coating layer is 30:70 or more and 99:1 or less, in mass ratio.

7. A method for manufacturing an adhesive sheet as described in Claim 6, wherein the printing coating layer formation process is carried out by applying an aqueous composition containing the high acid value polyurethane resin, the high acid value polyester resin, and water onto the substrate.

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