JP2005187738A - Pressure-sensitive adhesive sheet for surface coating, release sheet-covered pressure sensitive adhesive sheet for surface coating and pressure sensitive adhesive sheet combination - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure sensitive adhesive sheet for surface coating having excellent light resistance and good appearance, a release sheet-covered pressure-sensitive adhesive sheet for surface coating and pressure sensitive adhesive sheet combination. <P>SOLUTION: This pressure sensitive adhesive sheet 10 is for covering the surface on which characters, designs or patterns are recorded wherein the pressure-sensitive sheet 10 comprises a base material 1 that contains an ultraviolet absorber that is liquid at ordinary temperature and a pressure sensitive adhesive layer 2 formed on one face of the base material 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a combination of a surface-coated pressure-sensitive adhesive sheet, a surface-coated pressure-sensitive adhesive sheet with a release sheet, and an adhesive sheet that is coated on a surface on which characters and patterns are recorded. The present invention relates to a combination of an excellent adhesive sheet for surface coating, an adhesive sheet for surface coating with a release sheet, and an adhesive sheet.

  For outdoor advertisements and advertisements, a sheet on which letters and pictures are recorded and attached to a signboard or a vehicle body is used. Such sheets are used for the promotion of many types of products and services, or for the promotion of private stores, etc., so in general, as many types of sheets as needed are delivered in a short delivery time. There is a need. As such a sheet, an image-receiving pressure-sensitive adhesive sheet in which an image-receiving layer capable of recording characters and pictures on one surface of an image-receiving substrate and an adhesive layer formed on the other surface is used. The image-receiving pressure-sensitive adhesive sheet has a desired character or pattern printed on the image-receiving layer, and is simply attached to an adherend such as a signboard or a vehicle body via the pressure-sensitive adhesive layer.

  However, if the image-receiving adhesive sheet on which characters and pictures are recorded is stuck on an adherend while the surface on which the characters and pictures are recorded is exposed, the characters and patterns may be damaged. It may become contaminated. Therefore, a transparent surface-coated adhesive sheet with a pressure-sensitive adhesive layer formed on one side of the substrate is usually attached to the image-receiving adhesive sheet on which characters and pictures are recorded in order to protect the characters and pictures. Has been.

  The image-receiving pressure-sensitive adhesive sheet and the surface-covering pressure-sensitive adhesive sheet are usually distributed as a combination of a set of adhesive sheets, with a release sheet provided on each pressure-sensitive adhesive layer. In such a combination of adhesive sheets, a user who has purchased the combination of adhesive sheets prints, for example, a desired character or pattern on the image-receiving adhesive sheet by a desired printing method, After this image-receiving pressure-sensitive adhesive sheet is adhered to an adherend, the surface-coated pressure-sensitive adhesive sheet is adhered thereon. Then, after the advertisement display period and the like are finished, the combination of the pasting sheets that are no longer necessary is peeled off from the signboard, the vehicle body, or the like and disposed of.

This sticky sheet combination is used for outdoor advertising and publicity, etc., so that the letters and patterns formed on the image-receiving adhesive sheet may be discolored or surface coated by the action of ultraviolet rays contained in sunlight. There was a problem that the base material of the pressure-sensitive adhesive sheet deteriorates and cracks and the like occur. In order to solve such a problem, Patent Document 1 describes that a base material of a pressure-sensitive adhesive sheet for surface coating contains an ultraviolet absorber to improve the light resistance of the base material.
Japanese Patent Laid-Open No. 2002-241712

  However, in general, the UV absorber contained in the base material of the surface coating pressure-sensitive adhesive sheet is incompatible with each other because it is solid at room temperature, and may ooze out on the surface coating pressure-sensitive adhesive sheet surface over time. (Hereafter, such bleeding is referred to as bleed out.) In such a case, since the bleed-out ultraviolet absorber is crystallized, the surface of the surface-coated pressure-sensitive adhesive sheet is whitened, and characters recorded on the image-receiving pressure-sensitive adhesive sheet provided under this sheet There was a problem that it was difficult to see the pattern. In addition, since the ultraviolet absorber bleeds out to the surface of the pressure-sensitive adhesive sheet for surface coating, the content of the ultraviolet light absorber in the base material becomes insufficient, and the light resistance of the pressure-sensitive adhesive sheet for surface coating decreases. was there.

  The present invention has been made in order to solve the above-mentioned problems, and its purpose is to provide a surface-coated pressure-sensitive adhesive sheet excellent in light resistance and appearance, a surface-coated pressure-sensitive adhesive sheet with a release sheet, and an adhesive sheet. It is to provide a combination.

  The pressure-sensitive adhesive sheet for surface coating of the present invention for solving the above-mentioned problems is a pressure-sensitive adhesive sheet for surface coating that is coated on the surface on which characters and pictures are recorded, and is a base containing a UV absorber that is liquid at room temperature. It has a material and the adhesive layer formed in the single side | surface of the said base material, It is characterized by the above-mentioned.

  According to the present invention, since the ultraviolet absorbent contained in the base material of the pressure-sensitive adhesive sheet for surface coating is liquid at room temperature, the compatibility between the ultraviolet absorbent and the resin forming the base material is high. It is difficult to bleed out on the sheet surface. Even if the bleed-out occurs, the ultraviolet absorber is in a liquid state at room temperature, so that it does not crystallize and does not whiten. Accordingly, the appearance of the pressure-sensitive adhesive sheet for surface coating of the present invention is improved. Furthermore, in the surface-coated pressure-sensitive adhesive sheet of the present invention, since the ultraviolet absorber in the substrate is difficult to bleed out, a sufficient amount of the ultraviolet absorber is secured in the substrate, and the light resistance is improved.

  Moreover, it is preferable that the said base material is formed with the olefin resin in the adhesive sheet for surface coatings in the adhesive sheet for surface coatings of this invention.

  According to this invention, since the substrate for the surface coating is formed of an olefin-based resin, a chlorine compound-based gas such as dioxin is not generated even when incinerated, and is excellent in environmental safety.

  In the surface-coated pressure-sensitive adhesive sheet of the present invention, the surface-coated pressure-sensitive adhesive sheet of the present invention is preferably provided with a protective layer on the surface of the substrate opposite to the pressure-sensitive adhesive layer.

  The surface-coated pressure-sensitive adhesive sheet with a release sheet of the present invention for solving the above-mentioned problems is characterized in that a release sheet is provided on the pressure-sensitive adhesive layer of the surface-coated pressure-sensitive adhesive sheet.

  The bonded sheet assembly of the present invention for solving the above problems has at least an image receiving layer in which characters and pictures are recorded or an image receiving layer in which characters and pictures are recorded, an image receiving substrate and an adhesive layer, The adhesive sheet is a combination of an adhesive sheet for image reception in which the respective layers are formed in this order and an adhesive sheet for surface coating for covering the adhesive sheet for image reception, and the adhesive sheet for surface coating is It is characterized by having at least a base material containing an ultraviolet absorbent that is liquid at room temperature and an adhesive layer formed on one side of the base material.

  According to the pressure-sensitive adhesive sheet for surface coating and the pressure-sensitive adhesive sheet for surface coating with a release sheet of the present invention, the ultraviolet absorber is difficult to bleed out, and whitening does not occur even when bleeded out. An excellent pressure-sensitive adhesive sheet for surface coating can be provided. Therefore, the pressure-sensitive adhesive sheet for surface coating of the present invention is preferably used for outdoor advertising and advertisement.

  According to the combination of the adhesive sheets of the present invention, since the pressure-sensitive adhesive sheet for surface coating is excellent in appearance and weather resistance, it is possible to provide a combination of adhesive sheets that are preferably used for outdoor advertising and advertisement.

  Hereinafter, the pressure-sensitive adhesive sheet for surface coating of the present invention, the pressure-sensitive adhesive sheet for surface coating with a release sheet, the combination of the adhesive sheets of the present invention, and the pressure-sensitive adhesive sheet for image constituting the combination of the adhesive sheets of the present invention This will be described in detail with reference to the drawings.

(1) Surface coating adhesive sheet:
FIG. 1 is a cross-sectional view showing an example of the pressure-sensitive adhesive sheet 10 for surface coating according to the present invention. As shown in FIG. 1, the pressure-sensitive adhesive sheet 10 for surface coating of the present invention has a base material 1 and a pressure-sensitive adhesive layer 2 formed on one surface of the base material 1.

  The surface-coated pressure-sensitive adhesive sheet 10 of the present invention covers an image-receiving pressure-sensitive adhesive sheet on which characters and patterns are recorded, thereby protecting the characters and patterns from scratches and contamination, and changes the color of characters and patterns caused by ultraviolet rays. Or it prevents deterioration and the like.

(Base material)
The substrate 1 is a sheet-like or film-like resin layer, and contains a liquid ultraviolet absorber that is liquid at room temperature.

  Compared with conventional solid ultraviolet absorbers, liquid ultraviolet absorbers that are liquid at room temperature have good compatibility with the resin that forms the substrate 1, and therefore are difficult to bleed out on the surface of the pressure-sensitive adhesive sheet 10 for surface coating. Even if the bleed-out occurs, the ultraviolet absorber is liquid at room temperature, so it does not crystallize and whitening does not occur on the surface of the surface-coated pressure-sensitive adhesive sheet 10. Furthermore, since the ultraviolet absorber in the substrate 1 is difficult to bleed out, a sufficient amount of the ultraviolet absorber is secured in the substrate 1. Therefore, the light resistance of the pressure-sensitive adhesive sheet 10 for surface coating is improved.

  Moreover, as will be described later, the surface-coated pressure-sensitive adhesive sheet 10 having the base material 1 formed of an olefin-based resin may be cracked by being exposed outdoors for a long period of time, and such cracks are prevented. In order to do so, it is preferable to reduce the elastic modulus of the substrate 1. However, solid ultraviolet absorbers that have been conventionally used are easy to bleed out on the sheet surface, especially when they are contained in such a soft resin, and easily whiten. Moreover, in order not to cause whitening on the sheet surface, a large amount of ultraviolet absorber could not be added to such a flexible substrate. On the other hand, in the surface-coated pressure-sensitive adhesive sheet 10 of the present invention, since the ultraviolet absorbent used is liquid at room temperature, the ultraviolet absorbent is on the sheet surface even if the substrate is formed of such a soft olefin resin. It is difficult to bleed out, and even if bleed out, whitening does not occur.

  Here, “normal temperature” refers to a temperature at the time of use or storage of the pressure-sensitive adhesive sheet 10 for surface coating, and is usually a temperature within a range of 10 ° C. or higher and 30 ° C. or lower. That is, the ultraviolet absorber contained in the substrate 1 is liquid at least within this temperature range. “Liquid” means a state that has fluidity and is not crystallized, that is, a state under a temperature condition higher than the melting point (in the case of an amorphous substance having no melting point, a temperature higher than the melting point). State under conditions).

  Therefore, the ultraviolet absorber contained in the base material 1 should just have melting | fusing point or melting point of 10 degrees C or less at least. When the ultraviolet absorber has a melting point or melting point of 10 ° C. or lower, bleeding out hardly occurs at the temperature (10 ° C. or higher) at which the surface coating pressure-sensitive adhesive sheet 10 is normally used and stored. Since bleed-out hardly occurs at a temperature lower than a high temperature, for example, even when exposed outdoors under a temperature condition lower than this melting point or melting point, an ultraviolet absorber having this melting point or melting point is difficult to bleed out. The above effects are sufficiently exhibited.

  In addition, when the surface covering pressure-sensitive adhesive sheet 1 is used and stored in a wide area or in various environments, the temperature within the range of − (minus) 5 ° C. or more and 40 ° C. or less is normal temperature (that is, for surface coating) It may be the temperature at the time of use or storage of the adhesive sheet 10. Therefore, when the surface-coated pressure-sensitive adhesive sheet 10 is used / stored in a wider temperature range than usual, the melting point or melting point of the ultraviolet absorber is preferably −5 ° C. or lower.

  The ultraviolet absorber preferably has a boiling point higher than 40 ° C. When the ultraviolet absorber has a boiling point of 40 ° C. or lower, the efficacy may be lost due to evaporation of the ultraviolet absorber during use / storage of the surface covering pressure-sensitive adhesive sheet 10.

  Such an ultraviolet absorber is not particularly limited as long as it is liquid at room temperature. For example, 2- (2′-hydroxy-3′-dodecyl-5′-methylphenyl) benzotriazole, 2- (2 '-Hydroxy-3'-undecyl-5'-methylphenyl) benzotriazole, 2- [2'-hydroxy-4'-(2 "-ethylhexyl) oxyphenyl] benzotriazole or methyl-3- [3-tert- Salicylic acid such as benzotriazole UV absorbers such as condensate of butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionate and polyethylene glycol (molecular weight 300), homomenthyl salicylate or octyl salicylate UV absorber, methyl-2,5-diisopropylcinna Cinnamic acid UV absorbers such as ethyl-2,4-diisopropylcinnamate, isopropyl-p-methoxycinnamate or octyl-p-methoxycinnamate, and benzoic acid systems such as octyldimethyl-p-aminobenzoic acid An ultraviolet absorber, a triallyl triazine type ultraviolet absorber, etc. are mentioned.

  The content of the ultraviolet absorber is preferably 0.1 parts by weight or more and 1 part by weight or less with respect to 100 parts by weight of the resin forming the substrate 1. If the content of the ultraviolet absorber is less than 0.1 parts by weight, the required light resistance cannot be obtained. Further, even if the content of the ultraviolet absorber is increased to more than 1 part by weight, no further effect can be expected. On the contrary, the physical properties of the substrate 1 are affected, or the ultraviolet absorber tends to bleed out. 1 and the layer (adhesive layer 2 and protective layer 3 described later) adjacent to the substrate 1 may be lowered.

  From the viewpoint of environmental safety, the base material 1 is formed of a transparent resin such as an olefin resin, a polyester resin, an acrylic resin, a polycarbonate resin, or a vinyl chloride resin, and is formed of an olefin resin. Preferably it is. Conventionally, the vinyl chloride resin used for the formation of the substrate 1 may generate chlorine compound gas when incinerated, but the olefin resin may generate such chlorine compound resin even if incinerated. Therefore, the environmental safety of the pressure-sensitive adhesive sheet 10 for surface coating is improved.

  It is preferable that the base material 1 has transparency enough to allow the characters and patterns recorded on the image-receiving pressure-sensitive adhesive sheet to be the adherend of the surface-coated pressure-sensitive adhesive sheet 10 to be seen through. Specifically, the visible light transmittance of the substrate 1 is preferably about 70% or more.

  In the case where the substrate 1 is formed of an olefin resin, it is preferable that the elastic modulus of the substrate 1 is small. When the surface-coated pressure-sensitive adhesive sheet 10 having the base material 1 formed of an olefin-based resin is exposed to the adherend for a long time in a state of being stuck to the adherend through the pressure-sensitive adhesive layer 2, the base material 1 In-plane tensile stress is generated on the surface, and cracks are likely to occur. In such a case, if the elastic modulus of the base material 1 is small, the base material 1 is elastically deformed with respect to the generated tensile stress, so that such a crack is difficult to occur. The tensile stress is that the olefin resin is easily shrunk by irradiation with ultraviolet rays, and the base material 1 formed of this resin tends to shrink by irradiation with ultraviolet rays, whereas the base material 1 is a pressure-sensitive adhesive layer. Since it is adhered to the adherend by 2, the free shrinkage is prevented.

  Specifically, the base material 1 formed of an olefin resin preferably has an elastic modulus of 600 MPa or less, and more preferably 350 MPa or less. Here, the elastic modulus is measured by a plastic tensile test method of JIS-K7113. Specifically, the base material 1 processed into the shape of a No. 2 type test piece is subjected to a tensile test under the conditions of 25 ° C., a tensile speed of 50 mm / min, and a distance between grips of 80 mm. It is a value calculated in and.

The surface-coated pressure-sensitive adhesive sheet 10 having an elastic modulus of the base material 1 formed of an olefin resin of 600 MPa or less is attached to an adherend via the pressure-sensitive adhesive layer 2 and has an illuminance of 60 mW / cm ² ultraviolet rays. In the light resistance test in which the substrate 1 is irradiated, the base material 1 is hardly cracked even after 100 hours. Moreover, the adhesive sheet 10 for surface coating whose elastic modulus of the base material 1 is 350 MPa or less is unlikely to crack in the base material 1 even after 200 hours in the same light resistance test. In addition, this light resistance test uses an iSuper UV tester (manufactured by Iwasaki Electric Co., Ltd.) as a light resistance tester, the irradiation conditions of ultraviolet rays (wavelength 295 to 450 nm band), the illuminance is 60 mW / cm ² , and the distance from the light source. 240 mm, the black panel temperature is 46 ° C., and a stainless steel plate is used as the adherend of the surface-coated pressure-sensitive adhesive sheet 10. 100 hours of UV irradiation in this light resistance test corresponds to exposure to sunlight for one year outdoors, and 200 hours of UV irradiation corresponds to exposure to sunlight for two years outdoors.

  The lower limit of the elastic modulus of the base material 1 formed of the olefin resin is determined in consideration of the ease of handling at the time of processing and molding the base material 1 and depends on the composition of the resin as a material, but is usually about 200 MPa. is there. That is, a base material having an elastic modulus of less than 200 MPa is too sticky, and is difficult to form by attaching to a roll or the like when it is processed and molded using a calender roll machine (sheeting). There is.

  Examples of the olefin resin forming the substrate 1 include polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-propylene-butene copolymer, ethylene-vinyl alcohol copolymer, or olefin thermoplastic elastomer. be able to. These olefin-based resins may be used alone, or a plurality of types of resins may be mixed and used.

  Examples of the olefin resin forming the substrate 1 include olefin resins described in (A) JP-A-9-1111055. The base material 1 is preferably formed of an olefinic thermoplastic elastomer. The olefinic thermoplastic elastomer includes (B) a hard segment composed of a crystalline olefinic resin and an amorphous olefinic resin. An olefinic thermoplastic elastomer that is a mixture with a soft segment can be used. For example, (B-1) an olefinic thermoplastic elastomer described in JP-A-5-77371, (B-2) The olefinic thermoplastic elastomer described in Kaihei 7-316358, (B-3) the olefinic thermoplastic elastomer described in Japanese Patent Publication No. 6-23278, etc. can be used. Furthermore, as the olefinic thermoplastic elastomer, (C) an olefinic thermoplastic elastomer which is a mixture of a hard segment made of a crystalline olefinic resin and a soft segment made of a partially crosslinked olefinic elastomer (rubber). For example, (C-1) an olefinic thermoplastic elastomer described in JP-B-53-21021 and (C-2) olefin-based thermoplastic described in JP-B-53-34210. Elastomers, (C-3) olefinic thermoplastic elastomers described in JP-B-56-15741, and the like can be used.

  The olefin-based resin (A) is a transparent nucleating agent having a phosphoric acid aryl ester compound as a main component in an amount of 0.01 to 100 parts by weight of a random copolymer of ethylene, propylene and butene terpolymer. It is obtained by melt-kneading 50 parts by weight and 0.003 to 0.3 parts by weight of a fatty acid amide having 12 to 22 carbon atoms. When this olefin resin is used, the base material 1 excellent in rigidity and transparency can be formed. In addition, the rigidity of a resin composition becomes it high that the weight ratio of the propylene in a random copolymer is 90 weight% or more, and it becomes easy to shape | mold the base material 1. FIG. Moreover, it is preferable that the melt flow rate of this random copolymer is 1-50 g / 10min on 230 degreeC and 2.16 kg conditions.

  The olefinic thermoplastic elastomer (B-1) is a resin obtained by mixing crystalline polypropylene as a hard segment and amorphous polyolefin as a soft segment in which the weight ratio of the propylene component is 50% by weight or more. Preferred examples of the crystalline polypropylene include a propylene-ethylene random copolymer and a propylene-1 butene random copolymer. Preferable examples of the amorphous polyolefin include propylene-1 butene-ethylene terpolymer. If this olefinic thermoplastic elastomer is used, the base material 1 which is rich in flexibility and excellent in transparency and mechanical strength can be formed.

  The olefinic thermoplastic elastomer (B-2) was a mixture of a crystalline polyolefin as a hard segment and a low crystalline polyolefin as a soft segment having a propylene and / or 1-butene content of 50% by weight or more. A resin in which 0.5 parts by weight or more of an oil gelling agent such as an N acylamino acid amine salt or an N acylamino acid ester is added to 100 parts by weight of the composition. When this olefinic thermoplastic elastomer is used, the base material 1 which is rich in flexibility and whose surface adhesiveness is suppressed can be formed.

  The olefinic thermoplastic elastomer of (B-3) has a melt index of 0.1 to 4 g / 10 min and isotactic polypropylene as a hard segment insoluble in boiling heptane, a number average molecular weight Mn of 25,000 or more and A soft polypropylene composed of atactic polypropylene as a soft segment soluble in boiling heptane in which the ratio of the weight average molecular weight Mw to the number average molecular weight Mn is Mw / Mn ≦ 7. When this olefinic thermoplastic elastomer is used, the base material 1 which is rich in flexibility and excellent in mechanical properties can be formed.

  The olefinic thermoplastic elastomer (C-1) is produced by uniformly blending and mixing a crystalline olefin polymer as a hard segment and a partially cross-linked monoolefin copolymer rubber as a soft segment. Resin. Examples of the crystalline olefin polymer that is a hard segment include polyethylene, polypropylene, and polymethylpentene. Examples of the monoolefin copolymer rubber that is a soft segment include ethylene-propylene copolymer rubber, ethylene-propylene-non-polymer. Examples thereof include conjugated terpolymer diene rubber.

  The olefinic thermoplastic elastomer (C-2) is prepared by mixing an olefinic polymer as a hard segment and an uncrosslinked monoolefin copolymer rubber as a soft segment with the addition of a crosslinking agent, and melt kneading. This is a resin produced by partially crosslinking the soft segment.

  The olefin-based thermoplastic elastomer of (C-3) comprises a peroxide-decomposable olefin polymer as a hard segment, a peroxide-crosslinked olefin copolymer rubber and a peroxide non-crosslinked hydrocarbon rubber as a soft segment, It is a resin produced by adding a mineral oil softener such as a paraffinic or naphthenic softener and mixing them, and then melt-kneading them in the presence of an organic peroxide to partially crosslink soft segments. The peroxide-decomposable olefin polymer as a hard segment has the property that the molecular weight decreases and the fluidity increases when mixed and heated with a peroxide. As such a polymer, for example, isotactic polypropylene is used. , Propylene-ethylene copolymer, propylene-butene-1 copolymer and the like. Peroxide-crosslinked olefin copolymer rubber as a soft segment has the property of cross-linking and reducing fluidity when mixed with peroxide and heated, and examples of such copolymer rubber include ethylene- Examples include propylene copolymer rubber and ethylene-propylene-nonconjugated terpolymer diene rubber. Peroxide non-crosslinked hydrocarbon rubber as a soft segment has the property that it does not crosslink even when heated with a peroxide and does not change in fluidity. Examples of such hydrocarbon rubber include polyisobutylene and butyl rubber. Is mentioned.

  The weight ratio of the hard segment to the soft segment (hard segment: soft segment) in the olefin-based thermoplastic elastomer is usually 10:90 to 90:10, and within this range, the mechanical strength of the substrate 1, It is adjusted in consideration of the elastic modulus. In addition, the olefinic thermoplastic elastomer may contain an inorganic filler or the like as necessary. As the inorganic filler, powder having an average particle size of about 0.1 to 10 μm, such as calcium carbonate, barium sulfate, clay, and talc, is used. The added amount of the inorganic filler is usually about 0 to 20% by weight. In addition to the ultraviolet absorber, the substrate 1 may be added with a heat stabilizer, a flame retardant, a radical scavenger and the like.

  For the base material 1, a material obtained by melt-kneading the above materials and molding and processing it into a sheet shape or a film shape by a calendar method or the like is used, and an unstretched material or a uniaxially or biaxially stretched as required. Things are used. The thickness of the substrate 1 is preferably 40 to 100 μm.

  One or both surfaces of the substrate 1 are preferably subjected to easy adhesion treatment such as application of an easy adhesion primer layer, corona discharge treatment, plasma treatment, ozone treatment, flame treatment and the like. When the surface of the substrate 1 is subjected to easy adhesion treatment, the adhesiveness with the pressure-sensitive adhesive layer 2 and the protective layer 3 is improved. As the easy adhesion primer layer (also referred to as anchor coat), acrylic resin, vinyl chloride-vinyl acetate copolymer, polyester resin, urethane resin, chlorinated polypropylene, and polyethylene chloride can be used.

(Adhesive layer)
The pressure-sensitive adhesive layer 2 is formed on one side of the base material 1 for the purpose of bonding the base material 1 of the surface-coated pressure-sensitive adhesive sheet 10 to the image-receiving pressure-sensitive adhesive sheet on which characters and pictures are recorded. The pressure-sensitive adhesive layer 2 is usually a solid surface layer that is uniformly formed.

  It is preferable that the pressure-sensitive adhesive layer 2 has transparency enough to allow the characters and patterns recorded on the image-receiving pressure-sensitive adhesive sheet to be the adherend of the surface-coated pressure-sensitive adhesive sheet 10 to be seen through. Specifically, the visible light transmittance of the pressure-sensitive adhesive layer 2 is preferably about 60% or more.

  Examples of the pressure-sensitive adhesive used for forming the pressure-sensitive adhesive layer 2 include acrylic pressure-sensitive adhesives such as homopolymers of (meth) acrylic acid esters or copolymers of (meth) acrylic acid esters and other monomers, Synthetic rubber adhesives such as isoprene rubber, polybutadiene rubber or styrene-butadiene rubber, or natural rubber adhesives may be mentioned. “(Meth) acrylic acid” means acrylic acid or methacrylic acid. If necessary, a tackifier, a crosslinking agent, an antioxidant, an ultraviolet absorber and the like may be added to the adhesive.

  The pressure-sensitive adhesive layer 2 is formed by applying a coating agent in which the above-described pressure-sensitive adhesive is dissolved / dispersed in a solvent to a release sheet, with the coated surface of the release sheet facing one side of the substrate 1, 1 is formed by a transfer method in which the pressure-sensitive adhesive layer 2 is laminated on the substrate 1. As a method for applying the coating agent to the release sheet, methods such as a comma coating method, a roll coating method, and a bar coating method can be used. The release sheet used here is provided on the pressure-sensitive adhesive layer 2 as it is and becomes the release sheet 4 of the pressure-sensitive adhesive sheet for surface coating 100 with a release sheet to be described later. The thickness of the pressure-sensitive adhesive layer 2 is usually about 5 to 30 μm.

(Protective layer)
As shown in FIG. 1B, the surface covering pressure-sensitive adhesive sheet 10 may be provided with a protective layer 3 on the surface of the substrate 1 opposite to the pressure-sensitive adhesive layer 2 side.

  The protective layer 3 is arbitrarily provided on the base material 1 and has a role of protecting the base material 1 from scratches.

  It is preferable that the protective layer 3 has transparency enough to allow the characters and patterns recorded on the image-receiving pressure-sensitive adhesive sheet to be the adherend of the surface-coated pressure-sensitive adhesive sheet 10 to be seen through. Specifically, the visible light transmittance of the protective layer 3 is preferably about 70% or more.

  Examples of the material of the protective layer 3 include a thermosetting resin and an ionizing radiation curable resin. Here, ionizing radiation means electromagnetic waves or charged particles having energy capable of polymerizing or crosslinking molecules, and usually electron beams (EB) or ultraviolet rays (UV). In the resin forming the protective layer 3, a crosslinking agent, a heat stabilizer, a flame retardant, an ultraviolet absorber, a radical scavenger and the like may be added.

  The protective layer 3 is formed by applying a coating agent obtained by dissolving and dispersing the above materials in a solvent as necessary onto the base material 1 and curing it. The thickness of the protective layer 3 is preferably 1 to 30 μm.

(2) Adhesive sheet for surface coating with release sheet:
FIG. 2 is a cross-sectional view showing an example of the pressure-sensitive adhesive sheet with a release sheet of the present invention. The pressure-sensitive adhesive sheet for surface coating with a release sheet 100 of the present invention is such that the release sheet 4 is provided on the surface of the pressure-sensitive adhesive sheet for surface coating 10 on the pressure-sensitive adhesive layer 2 side.

  The release sheet 4 is a surface-coated pressure-sensitive adhesive sheet for the purpose of preventing the pressure-sensitive adhesive layer 2 from inadvertently adhering to other objects or blocking when the surface-coated pressure-sensitive adhesive sheet 10 is wound up. 10 and is temporarily bonded to the pressure-sensitive adhesive layer 2 until the surface-coated pressure-sensitive adhesive sheet 10 is used.

  As the release sheet 4, a release agent such as silicon resin is applied to the surface of paper such as high-quality paper, linter paper, sulfuric acid paper, glassine paper, kraft paper, or a resin sheet such as polyester resin or olefin resin. The machined one is used. The thickness of the release sheet 4 is usually 25 to 100 μm.

(3) Image-receiving adhesive sheet:
The image-receiving pressure-sensitive adhesive sheet constitutes a combination of the adhesive sheet of the present invention together with the above-mentioned surface-coated pressure-sensitive adhesive sheet, and is used as a recording medium on which characters and designs for advertisements and advertisements are recorded by printing or the like .

  FIG. 3A is a cross-sectional view illustrating an example of the image receiving pressure-sensitive adhesive sheet. As shown in FIG. 3 (A), the image-receiving pressure-sensitive adhesive sheet 20 is provided with an image-receiving layer 22 on which one side of an image-receiving substrate 21 is recorded with characters and patterns, and the other side has a pressure-sensitive adhesive layer 23. Is provided. FIG. 3B is a cross-sectional view illustrating an example of the image-receiving pressure-sensitive adhesive sheet 200 with a release sheet. In the image-receiving pressure-sensitive adhesive sheet 200 with a release sheet, a release sheet 24 is provided on the pressure-sensitive adhesive layer 23 of the image-receiving pressure-sensitive adhesive sheet 20.

  The image receiving substrate 21 is preferably formed of the same olefin resin as that of the substrate 1 described above from the viewpoint of environmental safety. In addition, the thickness of the image receiving base material 21 is 20-100 micrometers normally. The image receiving base material 21 preferably contains a colorant and has a concealing property so that the color and pattern of the adherend are not seen through. The color of the image receiving substrate 21 is preferably white that can record a desired character or pattern for general use, and may be black or chromatic depending on the application. Colorants include titanium white, antimony white, lead white, carbon black (black), yellow lead, titanium yellow, vermilion, cadmium red, ultramarine, cobalt blue and other inorganic pigments, isoindolinone yellow, quinacridone red, phthalocyanine blue Organic pigments and dyes such as metal pigments made of foil powder such as aluminum or brass, or pearlescent pigments made of foil powder such as titanium dioxide-coated mica or basic zinc carbonate are used.

  The image receiving layer 22 has a property of recording characters and pictures. That is, since characters and pictures are usually recorded with ink, the surface of the image receiving layer 22 on which characters and pictures are recorded has a property of repelling ink and closely contacting with ink (hereinafter referred to as ink acceptability).

  The image receiving layer 22 is formed of a resin having ink receptivity to ink used for recording characters and pictures. As such a resin, for example, urethane resin, polyester resin, acrylic resin, cellulose resin, vinyl chloride-vinyl acetate copolymer, etc. can be used alone, or two or more of these resins can be mixed. Can be used. In addition, the thickness of the image receiving layer 22 is 1-10 micrometers normally.

  An extender is preferably added to the image receiving layer 22. When the extender pigment is added, the surface of the image receiving layer 22 is roughened or made porous, and the ink receiving property of the image receiving layer 22 is improved. As extender pigments, calcium carbonate, silica, barium sulfate, porous ceramics, kaolinite, zeolite, white clay, diatomaceous earth, and the like can be used. Further, in order to improve the ink receiving property of the image receiving layer 22, the surface of the image receiving layer 22 may be subjected to corona discharge treatment, ozone treatment or the like.

  The pressure-sensitive adhesive layer 23 is provided on the surface of the image receiving substrate 21 opposite to the image receiving layer 22 for the purpose of bonding the image receiving substrate 21 and an adherend (signboard, vehicle body, etc.). As the pressure-sensitive adhesive used for forming the pressure-sensitive adhesive layer 23, the same pressure-sensitive adhesive as that of the pressure-sensitive adhesive layer 2 provided on the surface-coated pressure-sensitive adhesive sheet 10 can be used. A colorant may be added to the pressure-sensitive adhesive to supplement the concealability of the image receiving substrate 21. As the colorant, the colorant described in the column of the image receiving substrate 21 can be used.

  The pressure-sensitive adhesive layer 23 is formed by a transfer method using a release sheet, similarly to the formation of the pressure-sensitive adhesive layer 2 of the surface-coated pressure-sensitive adhesive sheet 10. As the release sheet, the same one as the release sheet 4 provided on the surface-coated pressure-sensitive adhesive sheet 100 with a release sheet can be used, as in the case of the surface-coated pressure-sensitive adhesive sheet 100 with a release sheet, The release sheet 24 of the image-receiving adhesive sheet 200 with the release sheet is provided on the adhesive layer 23 as it is. In addition, it is preferable that the thickness of the adhesive layer 23 is 5-30 micrometers.

(4) Bonded sheet combination:
In the combination of the adhesive sheets of the present invention, the image receiving layer 22 on which characters and pictures are recorded or the image receiving layer 22 on which characters and pictures are recorded, the image receiving substrate 21 and the adhesive layer 23 are formed in this order. The image-receiving pressure-sensitive adhesive sheet 20 and the surface-coated pressure-sensitive adhesive sheet 10 of the present invention for covering the image-receiving pressure-sensitive adhesive sheet 20 are combined.

  In FIG. 4, an example of the combination body of the sticking sheet of this invention is shown. As shown in FIG. 4, the surface-coated pressure-sensitive adhesive sheet 10 and the image-receiving pressure-sensitive adhesive sheet 20 are usually provided with a release sheet 4 or a release sheet 24 on the pressure-sensitive adhesive layer of each sheet, and a surface with a release sheet. It is stored and distributed as an adhesive sheet for covering 100 and an adhesive sheet for image receiving 200 with a release sheet. The form of these sheets may be a form of a take-up roll obtained by winding a long sheet, or may be a form of a single sheet obtained by processing the sheet into a desired shape such as a rectangle.

  The usage method of the combination body of the sticking sheet of this invention is demonstrated based on FIGS. First, an adhesive sheet combination in which a release sheet is provided on the pressure-sensitive adhesive layer of each sheet is prepared, and desired characters and designs are placed on the image-receiving layer 22 of the image-receiving pressure-sensitive adhesive sheet 200 with a release sheet. Recording is performed by a desired printing method or the like (FIG. 5). Here, the code | symbol 25 shows the ink which records a character and a picture. Examples of the printing method include silk screen printing, ink jet printing, sublimation transfer printing, electrophotographic printing, and heat-sensitive color printing.

  Next, the release sheet 24 of the image-receiving adhesive sheet 200 with the release sheet on which characters and pictures are recorded is peeled off, and the image-receiving adhesive sheet 20 is attached to a signboard, a vehicle body or the like through the exposed adhesive layer 23. It sticks to the body 26 (FIG. 6). FIG. 7 shows a state where the image receiving pressure-sensitive adhesive sheet 20 is adhered to the adherend 26.

  Thereafter, the release sheet 4 of the surface-coated adhesive sheet 100 with a release sheet is peeled off, and the surface-coated adhesive sheet 10 is adhered to the adherend 26 through the exposed adhesive layer 2. It sticks on the sheet | seat 20 (FIG. 8). FIG. 9 shows a state where the surface covering pressure-sensitive adhesive sheet 10 and the image receiving pressure-sensitive adhesive sheet 20 are combined and adhered to the adherend 26. After the advertisement display period and the like are finished, the surface covering pressure-sensitive adhesive sheet 10 and the image receiving pressure-sensitive adhesive sheet 20 are peeled off from the adherend 26.

  Such an adhesive sheet combination of the present invention is preferably used for outdoor advertising, advertisement, and the like because the surface covering pressure-sensitive adhesive sheet 10 is excellent in light resistance and appearance. Specific examples of the adherend sheet assembly include a building window, a door, an outer wall, a floor, a car body such as a bus or a train, and an outer surface of a vending machine.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. Hereinafter, “part” means “part by weight”.

(Example 1)
First, 2- (2′-hydroxy-3′-dodecyl-5′-methylphenyl) benzotriazole was used as an ultraviolet absorber, 1 part of this ultraviolet absorber and an olefin resin (isotactic polypropylene 70 as a hard segment). 100 parts of an olefinic thermoplastic elastomer consisting of a part and 30 parts of atactic polypropylene as a soft segment were melt-kneaded and molded by an extrusion method from a T-die to obtain a substrate having a thickness of 80 μm. In addition, this ultraviolet absorber was liquid at 10-40 degreeC.

  Next, a corona discharge treatment is applied to both surfaces of the base material, and a protective layer coating agent A having the following composition is applied to one surface of the substrate by a gravure roll coating method, followed by curing at 40 ° C. for 3 days. Curing was performed to form a protective layer having a thickness of 3 μm made of acrylic urethane resin.

Coating agent A for protective layer;
・ Acrylic polyol 100 parts ・ Hexamethylene diisocyanate 10 parts ・ Mixed solvent of toluene and methyl ethyl ketone (weight ratio 1: 1)

  Next, a polyethylene terephthalate film having a thickness of 25 μm having a release agent layer made of silicon resin formed on one side as a release sheet was used, and the following composition adhesive layer coating agent B was applied on the release agent layer as a comma. It was applied by a coating method and dried to form an adhesive layer having a thickness of 25 μm.

Coating agent B for adhesive layer;
・ Acrylic resin 100 parts ・ Hexamethylene diisocyanate 0.5 part ・ Mixed solvent of toluene and methyl ethyl ketone (weight ratio 1: 1)

  Thereafter, the pressure-sensitive adhesive layer and the base material surface on which the protective layer is not formed are laminated to face each other, and after curing for 3 days at a temperature of 40 ° C., the surface with the release sheet of Example 1 A pressure-sensitive adhesive sheet for coating was obtained.

(Example 2)
Next, an image-receiving adhesive sheet with a release sheet was prepared.

  First, a 25 μm-thick polyethylene terephthalate film having a release agent layer made of silicon resin formed on one side as a release sheet was used, and the adhesive layer coating agent C having the following composition was used as a release agent layer of the release sheet. The surface to be formed was applied by a comma coating method and dried to form an adhesive layer having a thickness of 25 μm on the release sheet.

Coating agent C for adhesive layer;
・ Acrylic resin 100 parts ・ Hexamethylene diisocyanate 0.5 part ・ Mixed solvent of toluene and methyl ethyl ketone (weight ratio 1: 1)

  Thereafter, as an image receiving substrate, a white olefin resin sheet having a thickness of 80 μm (100 parts of an olefin thermoplastic elastomer comprising 80 parts of isotactic polypropylene as a hard segment and 20 parts of atactic polypropylene as a soft segment) And 5 parts of titanium white were added to each other and subjected to corona discharge treatment on both sides to form an image receiving layer made of urethane resin and having a thickness of 5 μm. Laminate the surface of the image receiving substrate opposite to the image receiving layer side and the surface of the release sheet on the pressure sensitive adhesive layer side, and then cure for 3 days at a temperature of 40 ° C. to receive the image with the release sheet. A pressure-sensitive adhesive sheet was obtained.

(Comparative Example 1)
In the production of the surface-coated pressure-sensitive adhesive sheet with the release sheet of Example 1, the release of Comparative Example 1 was performed in the same manner as in Example 1 except that a solid benzotriazole-based UV absorber was used at 40 ° C. as the UV absorber. A surface-coated pressure-sensitive adhesive sheet was obtained.

(Evaluation of appearance)
About the obtained adhesive sheet for surface coating with a release sheet, the external appearance property was evaluated by observing the surface of the base material side visually after leaving at 40 degreeC atmosphere for 1 week.

  As a result, whitening due to bleeding out of the ultraviolet absorber was confirmed on the surface of the pressure-sensitive adhesive sheet for surface coating of Comparative Example 1, and the appearance was poor. On the other hand, no whitening was confirmed in the surface-coated pressure-sensitive adhesive sheet of Example 1, and the appearance was good.

1A is a cross-sectional view showing an example of the pressure-sensitive adhesive sheet for surface coating of the present invention, and FIG. 1B is a cross-sectional view showing another example of the pressure-sensitive adhesive sheet for surface coating of the present invention. It is sectional drawing which shows an example of the adhesive sheet for surface coating | cover with a release sheet of this invention. FIG. 3A is a cross-sectional view showing an example of the image-receiving pressure-sensitive adhesive sheet, and FIG. 3B is a cross-sectional view showing an example of the image-receiving pressure-sensitive adhesive sheet with a release sheet. It is sectional drawing which shows an example of the combination body of the sticking sheet of this invention. It is sectional drawing for demonstrating the usage method of the combination body of the sticking sheet of this invention. It is sectional drawing for demonstrating the usage method of the combination body of the sticking sheet of this invention. It is sectional drawing for demonstrating the usage method of the combination body of the sticking sheet of this invention. It is sectional drawing for demonstrating the usage method of the combination body of the sticking sheet of this invention. It is sectional drawing for demonstrating the usage method of the combination body of the sticking sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Adhesive layer 3 Protective layer 4 Release sheet 10 Surface-coated adhesive sheet 20 Image-receiving adhesive sheet 21 Image-receiving substrate 22 Image-receiving layer 23 Adhesive 24 Release sheet 100 Surface-coated adhesive sheet with release sheet 200 Image-sensitive adhesive sheet with release sheet

Claims (5)

It is a pressure-sensitive adhesive sheet for covering a surface on which a character or a pattern is recorded,
A pressure-sensitive adhesive sheet for surface coating, comprising: a base material containing an ultraviolet absorbent that is liquid at room temperature; and a pressure-sensitive adhesive layer formed on one side of the base material.   The pressure-sensitive adhesive sheet for surface coating according to claim 1, wherein the base material is formed of an olefin resin.   The pressure-sensitive adhesive sheet for surface coating according to claim 1, wherein a protective layer is provided on a surface of the base material opposite to the pressure-sensitive adhesive layer side.   A release sheet is provided on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet for surface coating according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive sheet for surface coating with a release sheet is provided. An image receiving layer on which characters and pictures are recorded or an image receiving layer on which characters and pictures are recorded, an image receiving substrate and an adhesive layer, and an image receiving adhesive sheet in which each layer is formed in this order, and the image receiving adhesive It is a combination of an adhesive sheet and a pressure-sensitive adhesive sheet for surface coating for covering the sheet,
The surface-coated pressure-sensitive adhesive sheet has at least a base material containing an ultraviolet absorber that is liquid at normal temperature, and a pressure-sensitive adhesive layer formed on one side of the base material. .

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