JP7800815B2 - Adhesive sheet, method for manufacturing adhesive sheet, and printed matter - Google Patents

Description

The present invention relates to an adhesive sheet, a method for manufacturing an adhesive sheet, and a printed matter.

Due to their excellent weather resistance and ability to conform to curved or uneven surfaces, polyvinyl chloride sheets have traditionally been widely used as decorative adhesive sheets for advertisements, signs, and other purposes.

For applications such as advertising and signage, replacement is often required at relatively short intervals, and small-lot production is sometimes required.

On the other hand, inkjet printing has the advantage of being highly on-demand and suitable for producing a wide variety of printed items in small quantities.

The inkjet method is also increasingly being applied to printing on decorative adhesive sheets.

However, when printing on conventional polyvinyl chloride using the inkjet method, there was a problem in that the inkjet print was prone to bleeding and becoming unclear.

In order to solve the above-mentioned problems that arise when printing using the inkjet method, sheet materials equipped with ink-receiving layers made of specific materials have been proposed (see, for example, Patent Document 1).

However, even such sheet materials have not been able to provide sufficiently excellent printability by the ink-jet method.
Furthermore, as described above, decorative adhesive sheets for advertisements, signs, etc. are required to be able to conform to curved or uneven surfaces, and therefore the substrate needs to have flexibility and extensibility. The sheet material of Patent Document 1 had insufficient flexibility and extensibility.

Patent No. 3745993

The object of the present invention is to provide an adhesive sheet that has excellent weather resistance and other properties and is suitable for printing by the inkjet method; to provide a method for manufacturing an adhesive sheet that can suitably produce such an adhesive sheet; and to provide a printed matter that has excellent weather resistance and other properties and has a printed area with excellent print quality that minimizes bleeding when printed by the inkjet method.

These objects can be achieved by the present invention as set forth in (1) to ( 7 ) below.
(1) A pressure-sensitive adhesive sheet used for printing by an inkjet method,
A substrate and a pressure-sensitive adhesive layer provided in contact with the substrate,
the substrate is made of a material containing polyvinyl chloride , a plasticizer , and a leveling agent ;
The average degree of polymerization of the polyvinyl chloride is 1000 or more and 2000 or less,
the content of the plasticizer in the base material is 25 parts by mass or more and 40 parts by mass or less relative to 100 parts by mass of the polyvinyl chloride,
the content of the leveling agent in the base material is 0.5 parts by mass or more and 20.0 parts by mass or less relative to 100 parts by mass of the polyvinyl chloride,
A pressure-sensitive adhesive sheet characterized in that the thickness of the substrate is 5 μm or more and 200 μm or less .

(2) The pressure-sensitive adhesive sheet according to (1) above, wherein the leveling agent is at least one selected from the group consisting of silicone-based leveling agents, acrylic-based leveling agents, and fluorine-based leveling agents.

(3) The pressure-sensitive adhesive sheet according to (1) or (2) above, wherein the substrate is formed by applying a liquid composition containing the polyvinyl chloride and the leveling agent to the surface of a support that has not been subjected to a release treatment, followed by drying.

(4) The pressure-sensitive adhesive sheet according to any one of (1) to (3) above, wherein the surface of the pressure-sensitive adhesive layer opposite the surface that comes into contact with the substrate is covered with a release liner.

( 5 ) A coating step of coating a liquid composition containing polyvinyl chloride , a plasticizer , and a leveling agent onto a support that has not been subjected to a release treatment;
a solidification step of solidifying the composition coated on the support to form a substrate;
a pressure-sensitive adhesive layer forming step of forming a pressure-sensitive adhesive layer on the surface of the base material formed on the support ,
The average degree of polymerization of the polyvinyl chloride is 1000 or more and 2000 or less,
the content of the plasticizer in the base material is 25 parts by mass or more and 40 parts by mass or less relative to 100 parts by mass of the polyvinyl chloride,
the content of the leveling agent in the base material is 0.5 parts by mass or more and 20.0 parts by mass or less relative to 100 parts by mass of the polyvinyl chloride,
A method for producing a pressure-sensitive adhesive sheet, wherein the thickness of the substrate is 5 μm or more and 200 μm or less .

( 6 ) The method for producing a pressure-sensitive adhesive sheet according to ( 5 ) above, wherein the composition further contains an organic solvent in addition to the polyvinyl chloride and the leveling agent.

( 7 ) A printed matter characterized in that a printed portion is formed by an inkjet method on the substrate of the pressure-sensitive adhesive sheet according to any one of (1) to ( 4 ) above.

The present invention provides an adhesive sheet that has excellent weather resistance and other properties and is highly suitable for printing by the inkjet method; it also provides a method for manufacturing an adhesive sheet that can suitably produce the adhesive sheet; and it also provides a printed matter that has excellent weather resistance and other properties and has a printed area with excellent print quality that minimizes bleeding when printed by the inkjet method.

1 is a schematic longitudinal sectional view showing a preferred embodiment of the pressure-sensitive adhesive sheet of the present invention. 1 is a schematic longitudinal sectional view showing a preferred embodiment of the method for producing a pressure-sensitive adhesive sheet of the present invention. 1 is a schematic longitudinal sectional view showing a preferred embodiment of a printed matter of the present invention. FIG. 1 is a schematic longitudinal cross-sectional view showing an example of a state in which a printed matter of the present invention is covered with a laminate sheet.

Preferred embodiments of the present invention will be described in detail below.
[1] Pressure-sensitive 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.
The adhesive sheet 10 is an adhesive sheet 10 used for printing by an inkjet method, and includes a substrate 11 and an adhesive layer 12 provided in contact with the substrate 11. The substrate 11 is made of a material containing polyvinyl chloride and a leveling agent.

This makes it possible to provide an adhesive sheet 10 that has excellent weather resistance and excellent printability by inkjet printing. It also makes it possible to achieve particularly excellent adhesion between the substrate 11 and the adhesive layer 12. It also makes it possible to achieve excellent film-forming properties, flexibility, and other characteristics. Furthermore, as will be described in detail later, during the production of the adhesive sheet 10, the substrate 11 formed on the support 300 can be easily peeled off, effectively preventing unintended roughening of the surface of the substrate 11 (the surface that was in contact with the support 300) and unintended stretching of the substrate 11, thereby improving the reliability and yield of the adhesive sheet 10.

On the other hand, if the above configuration is not met, such excellent effects will not be achieved.

For example, if the substrate is made of a material that does not contain polyvinyl chloride, it will be difficult to achieve sufficiently excellent weather resistance, conformability to curved or uneven surfaces, film-forming properties, flexibility, etc. for the entire pressure-sensitive adhesive sheet.

Furthermore, if the substrate is made of a material that does not contain a leveling agent, it becomes difficult to achieve sufficiently excellent printability using the inkjet method. More specifically, when applied to inkjet printing, the ink wets and spreads too much, causing the image to bleed, making it difficult to form a clear image. Furthermore, when manufacturing an adhesive sheet, if the substrate is formed by applying a liquid composition to a support and drying it, it becomes difficult to properly peel the formed substrate from the support, and unintended roughness of the surface of the substrate (the surface that was in contact with the support) or unintended stretching of the substrate is likely to occur. Furthermore, the yield of the adhesive sheet also decreases significantly.

[1-1] Substrate The substrate 11 is made of a material containing polyvinyl chloride and a leveling agent, and is the portion on which printing is performed by the inkjet method.

[1-1-1] Polyvinyl chloride Polyvinyl chloride has excellent weather resistance. In addition, when used in combination with a plasticizer, which will be described later, it has the characteristics of being excellent in flexibility, shape conformability, etc.

Polyvinyl chloride is a polymer containing vinyl chloride as a monomer component. Polyvinyl chloride may contain other monomer components in addition to vinyl chloride, but the content of monomer components other than vinyl chloride in polyvinyl chloride is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 0% by mass.
This makes the above-mentioned effects more pronounced.

The average degree of polymerization of the polyvinyl chloride contained in the substrate 11 is preferably 500 or more and 5,000 or less, more preferably 700 or more and 3,000 or less, and even more preferably 1,000 or more and 2,000 or less.

This allows the pressure-sensitive adhesive sheet 10 as a whole to have better weather resistance, flexibility, shape conformability, etc. In addition, it also allows for better affinity and compatibility between polyvinyl chloride and the leveling agent, making it possible to more significantly demonstrate the effects achieved by having polyvinyl chloride and a leveling agent coexist as described above.

The average degree of polymerization can be measured, for example, by a method in accordance with JIS K 6720-2:1999.
The content of polyvinyl chloride in the substrate 11 is preferably 50% by mass or more.

[1-1-2] Leveling Agent The leveling agent primarily functions to improve the printability of the pressure-sensitive adhesive sheet 10 by an inkjet method. Furthermore, when the pressure-sensitive adhesive sheet 10 is manufactured by a method described in detail below, the leveling agent also functions to improve the ease of peeling the substrate 11 from the support 300. This effectively prevents undesired roughness on the surface of the substrate 11 (the surface that was in contact with the support 300) and undesired elongation of the substrate 11, thereby improving the reliability and yield of the pressure-sensitive adhesive sheet 10. In particular, this effect can be achieved even when a support 300 that has not been subjected to a release treatment is used. By using a support 300 that has not been subjected to a release treatment in this way, problems such as the transfer of the release agent to the substrate 11 that has been in contact with the support 300 can be prevented.

Examples of the leveling agent include silicone-based leveling agents, acrylic-based leveling agents, fluorine-based leveling agents, vinyl-based leveling agents, and acetylene glycol-based leveling agents. It is preferable to use at least one selected from the group consisting of silicone-based leveling agents, acrylic-based leveling agents, and fluorine-based leveling agents.
This makes the above-mentioned effects more pronounced.

Examples of silicone leveling agents include BYK-300, BYK-302, BYK-306, BYK-310, BYK-315, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, BYK-344, BYK-370, BYK-375, BYK-377, BYK-UV3500, BYK-UV3510, and BYK-UV3570 (all of which are BYK products). Examples include the solid content of commercially available products such as 1711, 1751N, 1761, LS-001, and LS-050 (all manufactured by Kusumoto Chemicals, DISPARLON series), Granol 100, Granol 115, Granol 200, Granol 400, Granol 410, Granol 440, Granol 435, Granol 450, Granol 482, Granol B-1484, and Polyflow ATF-2 (all manufactured by TEGO).

Examples of acrylic leveling agents include BYK-350, BYK-352, BYK-354, BYK-355, BYK-358N, BYK-361N, BYK-392 (all manufactured by BYK Japan), OX-880EF, OX-881, OX-883, OX-883HF, OX-70, OX-77EF, OX-60, OX-710, OX-720, OX-720EF, OX-750HF, LAP-10, LAP-20, LAP-30, 1970, 230, LF-1980, LF-1982, LF-1983, LF-1984, LF-1985, LHP-95, LHP-96 (all manufactured by Kusumoto Chemicals Co., Ltd., DISPARLON series), Polyflow No. 3, Polyflow No. 7, Polyflow No. 50E, Polyflow No. 50EHF, Polyflow No. 54N, Polyflow No. 55, Polyflow No. 64, Polyflow No. 75, Polyflow No. 77, Polyflow No. 85, Polyflow No. 85HF, Polyflow No. Examples include the solid content of commercially available products such as Polyflow No. S, Polyflow No. 90, Polyflow No. 90D-50, Polyflow No. 95, Polyflow No. 300, Polyflow No. 460, Polyflow WS, Polyflow WS-30, and Polyflow WS-314 (all manufactured by Kyoeisha Chemical Co., Ltd.).

Examples of fluorine-based leveling agents include the solid content of commercially available fluorine-modified polymers such as BYK-340 and BYK-3441 (all manufactured by BYK Japan), and S-242, S-243, S-420, and S-431 (all manufactured by AGC Seimi Chemical Co., Ltd.).

Examples of vinyl-based leveling agents include the solid content of commercially available products such as LHP-90 and LHP-91 (both manufactured by Kusumoto Chemicals, DISPARLON series).

The content of the leveling agent in the substrate 11 per 100 parts by mass of polyvinyl chloride is preferably 0.5 parts by mass or more and 20.0 parts by mass or less, more preferably 1.0 parts by mass or more and 18.0 parts by mass or less, and even more preferably 2.5 parts by mass or more and 15.0 parts by mass or less.

This not only makes the aforementioned effects more pronounced, but also more effectively prevents ink from being repelled when printing using the inkjet method. In this way, ink bleeding and repelling are prevented to a higher degree, resulting in even better quality printing using the inkjet method.

[1-1-3] Plasticizer The substrate 11 contains a plasticizer in addition to the polyvinyl chloride and leveling agent described above.
A plasticizer is usually used to impart flexibility.

Examples of plasticizers include phthalate ester plasticizers such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, di-n-octyl phthalate, and dicyclohexyl phthalate; trimellitate ester plasticizers such as trioctyl trimellitate, triisononyl trimellitate, and triisodecyl trimellitate; adipic acid plasticizers such as dioctyl adipate, diisononyl adipate, and diisodecyl adipate; polyester plasticizers such as phthalate polyesters; phosphate ester plasticizers such as tricresyl phosphate, trioctyl phosphate, and triphenyl phosphate; and epoxy plasticizers such as epoxidized linseed oil and epoxidized butyl stearate.

The weight-average molecular weight of the polyester plasticizer is preferably 2,000 or more and 6,000 or less.

The plasticizer content is preferably 25 to 40 parts by weight, and more preferably 27 to 35 parts by weight, per 100 parts by weight of polyvinyl chloride.

[1-1-4] Colorant The substrate 11 may contain a colorant.

For example, various pigments and dyes can be used as colorants, but pigments are preferred from the standpoint of light resistance, etc.

If the substrate 11 is white, titanium oxide, for example, can be suitably used as the colorant (pigment).

[1-1-5] Other Components The substrate 11 may contain components other than those described above. Examples of such components include resin materials other than polyvinyl chloride, cellulose, cellulose derivatives, various fillers, dispersants, UV absorbers, antistatic agents, antioxidants, pH adjusters, preservatives, rust inhibitors, deodorizers, antibacterial agents, antifungal agents, antiviral agents, disinfectants, crosslinking agents, polymerization initiators, fixing agents, and flocculants.

However, the content of components other than polyvinyl chloride, leveling agent, plasticizer, and colorant in the base material 11 is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, per 100 parts by mass of polyvinyl chloride.

[1-1-6] Other Conditions of the Substrate The substrate 11 may have a substantially uniform composition throughout, or may have portions with different compositions, as long as the entire substrate has sufficient flexibility and curve-conforming ability. For example, the substrate 11 may be made of a gradient material whose composition changes gradually in the thickness direction, or may be a laminate having multiple layers. Furthermore, different portions within the plane of the substrate 11 may have different compositions.

The thickness of the substrate 11 is preferably 5 μm or more and 200 μm or less, and more preferably 20 μm or more and 100 μm or less.

This allows the adhesive sheet 10 to achieve both flexibility and durability at a higher level. It also makes the adhesive sheet 10 easier to handle when adhering to an adherend. Furthermore, when manufacturing the adhesive sheet 10 using a method described in detail below, it allows the substrate 11 to be more easily peeled from the support 300.

The substrate 11 may be formed by any method, but is preferably formed, for example, by a casting method using a liquid composition containing the above-mentioned components. Forming the substrate by a casting method can prevent undesired thermal shrinkage after application.

In particular, it is preferable that the substrate 11 be formed by applying a liquid composition containing polyvinyl chloride and a leveling agent to the surface of a support 300 that has not been subjected to a release treatment, drying the composition, and then peeling off the support 300.

This prevents the release agent from transferring to the substrate 11 that has been in contact with the support 300, and more effectively prevents ink from being repelled when forming the printed portion 30 using an inkjet method. As a result, the print quality of the printed portion 30 can be improved.

The method for forming the substrate 11 and the method for manufacturing the adhesive sheet 10 will be explained in detail later.

[1-2] Adhesive Layer The adhesive layer 12 is made of a material containing an adhesive, and is the portion that comes into contact with the adherend when the sheet is attached to the adherend.

[1-2-1] Pressure-sensitive adhesive The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 12 is not particularly limited, and examples thereof include acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, silicone pressure-sensitive adhesives, polyurethane pressure-sensitive adhesives, and polyester pressure-sensitive adhesives.

Among these, acrylic adhesives are preferred. Acrylic adhesives are generally made by crosslinking a copolymer of a (meth)acrylic acid alkyl ester monomer, which provides adhesiveness, and a monomer containing a functional group with a crosslinking agent.

Examples of (meth)acrylic acid alkyl ester monomers that impart tack include butyl acrylate and 2-ethylhexyl acrylate.

Examples of monomers containing functional groups include 2-hydroxyethyl (meth)acrylate and (meth)acrylic acid.

Examples of crosslinking agents include isocyanate compounds, epoxy compounds, and metal chelate compounds.

[1-2-2] Other Components The pressure-sensitive adhesive layer 12 may contain components other than the above-described pressure-sensitive adhesives. Examples of such components include tackifiers, plasticizers, colorants such as pigments and dyes, various fillers, surfactants, dispersants, UV absorbers, antistatic agents, leveling agents, antioxidants, pH adjusters, preservatives, antirust agents, deodorizers, antibacterial agents, antifungal agents, antiviral agents, disinfectants, crosslinking agents, and polymerization initiators.

Examples of tackifiers that can be used include rosin-based resins such as rosin, rosin phenolic resins, and their ester compounds, hydrogenated rosin esters, terpene-based resins such as terpene oligomers, terpene phenolic resins, and aromatic-modified terpene resins, C5 petroleum resins, and C9 petroleum resins. Hydrogenated rosin esters and/or aromatic-modified terpene resins are more preferably used.

However, it is preferable that the content of components other than the adhesive in the adhesive layer 12 be 15% by mass or less.

[1-2-3] Other Conditions of the Pressure-Sensitive Adhesive Layer The pressure-sensitive adhesive layer 12 may have a substantially uniform composition throughout, or may have portions with different compositions. For example, the pressure-sensitive adhesive layer 12 may be composed of a gradient material whose composition changes gradually in the thickness direction, or may be a laminate having multiple layers. Furthermore, different portions within the plane of the pressure-sensitive adhesive layer 12 may have different compositions.

The thickness of the adhesive layer 12 is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 60 μm or less.

[1-3] Overall Configuration of the Pressure-Sensitive Adhesive Sheet The thickness of the pressure-sensitive adhesive sheet 10 is preferably 10 μm or more and 300 μm or less, and more preferably 40 μm or more and 160 μm or less.

This allows the adhesive sheet 10 to achieve both flexibility and durability at a higher level. It also makes the adhesive sheet 10 easier to handle when adhering it to an adherend.

[1-4] Release Liner The surface of the pressure-sensitive adhesive layer 12 of an unused pressure-sensitive adhesive sheet 10, i.e., the surface of the pressure-sensitive adhesive layer 12 opposite to the surface that comes into contact with the substrate 11, is preferably covered with a release liner 20, as shown in FIG. 1 .

This makes it easier to handle unused adhesive sheet 10 and also provides optimal protection for the adhesive layer 12 before it is attached to the adherend.

The release liner 20 may be, for example, a sheet made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene, polypropylene, or polyarylate, or a base material made of various paper materials such as polyethylene-laminated paper, polypropylene-laminated paper, clay-coated paper, resin-coated paper, glassine paper, or fine paper, with the surface of the base material in contact with the adhesive layer 12 optionally subjected to a release treatment.

Examples of release treatments include forming a release agent layer made of a release agent such as a silicone resin, a long-chain alkyl resin, or a fluorine-based resin.

[2] Method for Producing Pressure-Sensitive Adhesive Sheet Next, a method for producing the pressure-sensitive adhesive sheet of the present invention will be described.

Figure 2 is a schematic longitudinal cross-sectional view showing a preferred embodiment of the method for producing a pressure-sensitive adhesive sheet of the present invention.

The manufacturing method of the embodiment shown in Figure 2 includes a coating step (1a) in which a liquid composition containing polyvinyl chloride and a leveling agent is coated onto a support 300 that has not been subjected to a release treatment; a solidification step (1b) in which the composition coated on the support 300 is solidified to form a substrate 11; and a pressure-sensitive adhesive layer formation step (1c) in which a pressure-sensitive adhesive layer 12 is formed on the surface of the substrate 11 formed on the support 300.

This provides a method for manufacturing an adhesive sheet 10 that can suitably produce an adhesive sheet 10 that has excellent weather resistance and excellent printability by inkjet printing. It also provides particularly excellent adhesion between the substrate 11 and the adhesive layer 12. It also provides excellent film-forming properties, flexibility, and other properties. It also allows the substrate 11 formed on the support 300 to be suitably peeled off, effectively preventing unintended roughening of the surface of the substrate 11 (the surface that was in contact with the support 300) and unintended stretching of the substrate 11, resulting in excellent reliability and yield of the adhesive sheet 10.

[2-1] Coating Step In the coating step, a liquid composition 11' containing polyvinyl chloride and a leveling agent is coated onto a support 300 that has not been subjected to a release treatment (see (1a) in FIG. 2).

Composition 11' may contain at least polyvinyl chloride and a leveling agent, but preferably also contains a plasticizer and an organic solvent.

This allows composition 11' to have more suitable fluidity, enabling the coating process to be carried out more efficiently. In particular, sufficient fluidity can be ensured without excessively heating composition 11' during the coating process, making it possible to more effectively prevent unintended denaturation, deterioration, etc. of the components of composition 11', improving the reliability of the pressure-sensitive adhesive sheet 10 produced and also being preferable from the perspective of energy conservation, etc.

Examples of organic solvents that may be used in composition 11' include methyl isobutyl ketone, methyl ethyl ketone, butyl acetate, ethylene glycol monobutyl ether, tetrahydrofuran, benzene, toluene, xylene, paraffinic hydrocarbons, and naphthenic hydrocarbons. One or more of these may be used in combination. Commercially available mixed solvents made from petroleum fractions may also be used.

When composition 11' contains an organic solvent, the content of the organic solvent in composition 11' is not particularly limited, but is preferably 10% by mass or more and 90% by mass or less, more preferably 15% by mass or more and 85% by mass or less, and even more preferably 20% by mass or more and 80% by mass or less.

Any material may be used as the support 300, but a film made of a resin material such as polyethylene terephthalate is preferred.

In particular, it is preferable that the support 300 has not been subjected to a release treatment using a release agent.

This prevents problems such as uneven transfer of the release agent to the substrate 11 that was in contact with the support 300, and more effectively prevents ink from being repelled when forming the printed portion 30 on the manufactured pressure-sensitive adhesive sheet 10 using an inkjet method. As a result, the printing quality of the printed portion 30 can be improved.

[2-2] Solidification Step In the solidification step, the composition 11' applied onto the support 300 is solidified to form the substrate 11 (see (1b) in FIG. 2).

When composition 11' contains an organic solvent, this step can be carried out by, for example, volatilizing the organic solvent from composition 11' coated on support 300 by heating, reducing pressure, or the like, and then heating and melting the vinyl chloride to gel it. The heating and melting temperature is preferably 170°C or higher and 220°C or lower, and more preferably 180°C or higher and 200°C or lower.

Furthermore, if composition 11' does not contain an organic solvent and the coating process is carried out while composition 11' is in a molten state, this process (solidification process) can be carried out by cooling.

[2-3] Pressure-sensitive adhesive layer forming step In the pressure-sensitive adhesive layer forming step, a pressure-sensitive adhesive layer 12 is formed on the surface of the substrate 11 formed on the support 300 (see (1c) in FIG. 2).

The adhesive layer 12 may be formed, for example, by applying a liquid adhesive composition to the surface of the substrate 11 (the surface opposite the surface that comes into contact with the support 300) and allowing the dilution solvent to dry, or by applying a liquid adhesive composition to a release liner 20, allowing the dilution solvent to dry, and then transferring the composition to the surface of the substrate 11 (the surface opposite the surface that comes into contact with the support 300).

This process forms an adhesive sheet 10, which is a laminate of a substrate 11 and an adhesive layer 12, on the support 300.

[2-4] Peeling Step This embodiment further includes a peeling step of peeling the formed laminate of the substrate 11, the pressure-sensitive adhesive layer 12, and the release liner 20 from the support 300 (see (1d) in FIG. 2). This peeling step may be performed at any time after the pressure-sensitive adhesive layer forming step and before printing.

This results in a laminate in which the adhesive layer 12 of the adhesive sheet 10, which is a laminate of the substrate 11 and the adhesive layer 12, is protected by the release liner 20.

In this way, by peeling the adhesive layer 12 of the adhesive sheet 10 from the support 300 while it is protected by the release liner 20, it is possible to effectively prevent the adhesive layer 12 from being unintentionally soiled or the adhesive sheet 10 from adhering to unintended locations during the peeling process or subsequent processing.

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

Figure 3 is a schematic vertical cross-sectional view showing a preferred embodiment of the printed matter of the present invention. Figure 4 is a schematic vertical cross-sectional view showing an example of the printed matter of the present invention covered with a laminate sheet.

The printed matter 100 is characterized by a printed portion 30 formed by the inkjet method on the substrate 11 of the adhesive sheet 10.

This allows for the provision of printed matter with excellent weather resistance and other properties, as well as high-quality print areas with minimal bleeding due to the inkjet method.

The ink used to form the printed portion 30 is not particularly limited, and examples include oil-based ink (solvent-based ink), water-based ink, latex ink, and photocurable ink (ultraviolet-curable ink, electron beam-curable ink). Of these, oil-based ink (solvent-based ink) is more preferred.

Conventionally, when such inks were used to form printed sections using the inkjet method, the problems described above were particularly likely to occur. However, according to the present invention, even when such inks are used, the occurrence of the problems described above can be effectively prevented. In other words, the effects of the present invention are more pronounced when the inks described above are used to form printed sections 30.

Furthermore, the printed portion 30 may be formed using a combination of two or more types of ink.
In the illustrated configuration, the printed portion 30 is provided on the entire surface of the substrate 11 , but the printed portion 30 may be provided on only a part of the surface of the substrate 11 .

The printed portion 30 may be formed before the adhesive sheet 10 is stuck to the adherend, or may be formed after the adhesive sheet 10 is stuck to the adherend.
The content displayed by the printing unit 30 is not particularly limited.

The printed matter 100 may be used as is, adhered to an adherend, or, for example, as shown in Figure 4, the surface on which the printed portion 30 is provided may be covered with a laminate sheet 200.

The configuration of the laminate sheet 200 is not particularly limited, but the illustrated configuration includes a laminate sheet substrate 50 and an adhesive layer 60.

The laminate sheet substrate 50 may be made of any material, but is typically made primarily of a resin material.

Examples of resin materials that make up the laminate sheet substrate 50 include polyvinyl chloride, acrylic resin, and fluorine-based resin.

The thickness of the laminate sheet substrate 50 is preferably 10 μm or more and 100 μm or less, and more preferably 20 μm or more and 80 μm or less.

The adhesive layer 60 is made of a material containing an adhesive and is the part that comes into contact with the surface of the printed matter 100 on which the printed portion 30 is provided.

The adhesive that constitutes the adhesive layer 60 is not particularly limited, and examples include acrylic adhesives, rubber adhesives, silicone adhesives, polyurethane adhesives, polyester adhesives, etc.

The thickness of the adhesive layer 60 is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 60 μm or less.

When covering the printed matter 100 with the laminate sheet 200, the covering of the printed matter 100 with the laminate sheet 200 may be performed before or after the printed matter 100 is attached to the substrate.

The printed matter of the present invention can be used, for example, for various public relations purposes, advertisements, signs, etc. These include, for example, wrapping the body of a vehicle, adhering to a wall, etc.

The above describes preferred embodiments of the present invention, but the present invention is not limited to these.

For example, in the illustrated configuration, the printed portion is provided on the substrate, but part of the printed portion may also penetrate into the substrate.

In addition, in the above-described embodiment, a peeling step is performed to peel the substrate from the support after forming an adhesive layer on the surface of the substrate. However, the peeling step may be performed before forming an adhesive layer on the surface of the substrate, and then forming an adhesive layer on the substrate that has been peeled from the support. In this case, it is preferable that the adhesive layer be provided on the surface of the substrate opposite to the surface that was in contact with the support.

In addition, while the above-described embodiment has been primarily described as a case where a substrate is manufactured using a support that has not been subjected to a release treatment, a support that has been subjected to a release treatment may also be used to manufacture the substrate.

The present invention will be described in detail below based on specific examples, but the present invention is not limited to these. Treatments and measurements in the following examples, where no temperature conditions are specified, were carried out at 25°C.

[4] Production of adhesive sheet (Example 1)
A liquid composition was obtained by dispersing 100 parts by mass of polyvinyl chloride (Tosoh Corporation, Ryuron Paste 860) having an average degree of polymerization of 1600, 30 parts by mass of an adipic acid-based polyester plasticizer (ADEKA Corporation, P-200), and 2.5 parts by mass of an acrylic copolymer leveling agent (BYK Japan KK, BYK-392) (all solids ratios) in ethylene glycol monobutyl ether as an organic solvent. The content of the organic solvent in the resulting composition was 30% by mass.

The composition thus obtained was applied to a polyethylene terephthalate film (without release treatment) as a support by a casting method, and then dried to produce a substrate with a thickness of 50 μm.

On the other hand, the pressure-sensitive adhesive composition was coated onto the release agent-treated surface of the release liner using a roll knife coater so that the coating thickness after drying would be 25 μm, and then dried at 90° C. for 1 minute.
An acrylic adhesive was used as the adhesive composition.

Next, this dried adhesive composition (adhesive layer) was brought into contact with the substrate produced as described above, and the support was then peeled off and removed to obtain an adhesive sheet in which the adhesive layer was protected by the release liner.

Example 2
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1, except that a polyether-modified polymethylalkylsiloxane leveling agent (BYK-320, manufactured by BYK Japan) was used instead of the acrylic copolymer leveling agent.

Example 3
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1, except that a C ₆ F ₁₃ fluorotelomer-containing acrylic copolymer leveling agent (BYK-3441, manufactured by BYK Japan) was used instead of the acrylic copolymer leveling agent.

Examples 4 to 9
Pressure-sensitive adhesive sheets were produced in the same manner as in Example 1, except that the type and amount of leveling agent used were changed so that the substrate had the structure shown in Table 1.

(Comparative Example 1)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1, except that the composition used to form the substrate did not contain a leveling agent; more specifically, a composition obtained by dispersing 100 parts by mass of polyvinyl chloride (manufactured by Tosoh Corporation, Ryuron Paste 860) having an average degree of polymerization of 1600 and 30 parts by mass of adipic acid-based polyester plasticizer (manufactured by ADEKA Corporation, P-200) (all solid content ratios) in ethylene glycol monobutyl ether as an organic solvent was used.

(Comparative Example 2)
A pressure-sensitive adhesive sheet was produced in the same manner as in Comparative Example 1, except that a polyethylene terephthalate film that had been subjected to a release treatment with silicone was used as the support.

The configurations of the PSA sheets of the examples and comparative examples are summarized in Table 1. In Table 1, the solid content of polyvinyl chloride (manufactured by Tosoh Corporation, Ryuron Paste 860) is indicated as "PVC1," the solid content of adipic acid polyester plasticizer (manufactured by ADEKA Corporation, P-200) is indicated as "P1," the solid content of an acrylic copolymer leveling agent (manufactured by BYK Japan, BYK-392) is indicated as "LA1," the solid content of a polyether-modified polymethylalkylsiloxane leveling agent (manufactured by BYK Japan, BYK-320) is indicated as "LA2," and the solid content of a _{C6F13 fluorotelomer} -containing acrylic copolymer leveling agent (manufactured by BYK Japan, BYK-3441) is indicated as "LA3."

[5] Production of Printed Matter A printed portion was formed by printing the identification number N1 (portrait) of a high-definition color digital standard image defined in JIS X 9201:2001 on the surface of the substrate side of the PSA sheet of each of the Examples and Comparative Examples by an inkjet method using an inkjet printer (JV33-130, manufactured by Mimaki Engineering Co., Ltd.), thereby obtaining a printed matter.

The ink used here was SS21 ink (manufactured by Mimaki Engineering Co., Ltd.), a solvent-based ink (oil-based ink).

[6] Evaluation The printed matter of each of the examples and comparative examples was evaluated as follows.

[6-1] Evaluation of Bleeding The printed surface of the printed matter of each of the examples and comparative examples was visually observed and evaluated according to the following criteria.

A: A very clear appearance with no bleeding observed.
B: Sufficiently clear appearance with almost no bleeding observed.
C: Slight bleeding is observed, but the appearance is relatively clear.
D: Blurring is clearly observed and the image is not clear enough.
E: Significant bleeding is observed, and the image appears unclear.

[6-2] Evaluation of Repelling Effect The printed surface of each of the examples and comparative examples was visually observed and evaluated according to the following criteria.

A: A very clear appearance with no ink repellency observed.
B: The appearance is sufficiently clear with almost no ink repellency observed.
C: A slight ink repellency was observed, but the appearance was relatively clear.
D: Ink repellency is clearly observed, and clarity is insufficient.
E: Ink repellency is evident, and the appearance is unclear.

[6-3] Weather Resistance Evaluation The pressure-sensitive adhesive sheets of the above examples and comparative examples were attached to an acrylic coated plate and subjected to a 2000-hour accelerated weather resistance test using a sunshine weather meter, and were evaluated according to the following criteria.

A: No cracks or yellowing are observed.
B: Slight cracking or yellowing is observed.
C: Cracks and yellowing are clearly observed.
These results are summarized in Table 2.

As is clear from Table 2, the pressure-sensitive adhesive sheets of the above Examples achieved excellent results. In contrast, the pressure-sensitive adhesive sheets of the above Comparative Examples did not achieve satisfactory results. In particular, in Comparative Example 1, roughness of the substrate surface occurred when the substrate was peeled from the support, and undesired stretching of the substrate was observed. Furthermore, in Comparative Example 2, in which the support was subjected to a release treatment, significant ink repellency occurred. This is thought to be due to the release agent used in the release treatment of the support migrating to the substrate. Furthermore, pressure-sensitive adhesive sheets were manufactured in the same manner as in the above Examples and Comparative Examples, except that the average degree of polymerization of polyvinyl chloride was varied within the range of 1000 to 2000, and the thickness of the substrate was varied within the range of 5 μm to 200 μm. These were then evaluated in the same manner as above, and the same results were obtained.

REFERENCE SIGNS LIST 10... adhesive sheet 11... substrate 11'... composition 12... adhesive layer 20... release liner 30... printed portion 50... laminate sheet substrate 60... adhesive layer 100... printed matter 200... laminate sheet 300... support

Claims (7)

An adhesive sheet used for printing by an inkjet method,
A substrate and a pressure-sensitive adhesive layer provided in contact with the substrate,
the substrate is made of a material containing polyvinyl chloride , a plasticizer , and a leveling agent ;
The average degree of polymerization of the polyvinyl chloride is 1000 or more and 2000 or less,
the content of the plasticizer in the base material is 25 parts by mass or more and 40 parts by mass or less relative to 100 parts by mass of the polyvinyl chloride,
the content of the leveling agent in the base material is 0.5 parts by mass or more and 20.0 parts by mass or less relative to 100 parts by mass of the polyvinyl chloride,
A pressure-sensitive adhesive sheet characterized in that the thickness of the substrate is 5 μm or more and 200 μm or less . The pressure-sensitive adhesive sheet according to claim 1, wherein the leveling agent is at least one selected from the group consisting of silicone-based leveling agents, acrylic-based leveling agents, and fluorine-based leveling agents. The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the substrate is formed by applying a liquid composition containing the polyvinyl chloride and the leveling agent to the surface of a support that has not been subjected to a release treatment, followed by drying. The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the surface of the pressure-sensitive adhesive layer opposite the surface that comes into contact with the substrate is covered with a release liner. a coating step of coating a liquid composition containing polyvinyl chloride , a plasticizer , and a leveling agent onto a support that has not been subjected to a release treatment;
a solidification step of solidifying the composition coated on the support to form a substrate;
a pressure-sensitive adhesive layer forming step of forming a pressure-sensitive adhesive layer on the surface of the base material formed on the support ,
The average degree of polymerization of the polyvinyl chloride is 1000 or more and 2000 or less,
the content of the plasticizer in the base material is 25 parts by mass or more and 40 parts by mass or less relative to 100 parts by mass of the polyvinyl chloride,
the content of the leveling agent in the base material is 0.5 parts by mass or more and 20.0 parts by mass or less relative to 100 parts by mass of the polyvinyl chloride,
A method for producing a pressure-sensitive adhesive sheet, wherein the thickness of the substrate is 5 μm or more and 200 μm or less . The method for producing a pressure-sensitive adhesive sheet according to claim 5 , wherein the composition further contains an organic solvent in addition to the polyvinyl chloride and the leveling agent. A printed matter, comprising the adhesive sheet according to claim 1 , and a printed portion formed by an inkjet method on the substrate of the adhesive sheet.