JP6623275B1 - Laminated sheet - Google Patents

Abstract

An object of the present invention is to provide a laminated sheet which is decorated by printing an image on a base material containing a fluororesin by an ink jet method and has excellent image adhesion and weather resistance. The substrate includes a substrate and an inkjet image layer formed on the substrate, wherein the substrate is a single layer or a multi-layer, includes a first fluororesin, and the inkjet image layer has a first layer. A layer to which a fluororesin ink containing a second fluororesin that is the same as or different from the fluororesin is applied, and the water contact angle of the printing surface of the substrate on which the inkjet image layer is formed is 50 to 75 °. , Laminated sheets. [Selection diagram] None

Description

  The present invention relates to a laminated sheet. More specifically, the present invention relates to a laminated sheet that is decorated by printing an image on a base material containing a fluororesin by an inkjet method and that exhibits excellent image adhesion and weather resistance.

  In recent years, as a printed matter having excellent weather resistance, a sheet using a base material containing a fluororesin has attracted attention. However, in general, a base material containing a fluororesin is difficult to be colored. Therefore, Patent Document 1 discloses a method for printing on a fluororesin sheet, wherein a fluororesin sheet is coated with a dispersion containing a fluororesin and baked to form a receiving layer made of the fluororesin. . Patent Document 2 discloses a fluororesin laminated film in which a printing layer containing a fluororesin composition is formed on a fluororesin film by screen printing.

JP 2012-223734 A Japanese Patent Laid-Open No. 3-142237

  However, the method described in Patent Document 1 is a method using a so-called sublimation ink, the printing process is complicated, and the weather resistance of the obtained sheet has room for improvement. Moreover, the method described in Patent Document 2 is a method of forming a printed layer containing a fluororesin by screen printing, and is not simple. That is, until now, there is no known technique for forming an image layer in which a fluororesin ink is applied to a substrate containing a fluororesin by an inkjet method, and it is added by printing an image by an inkjet method. It is also not known to decorate and produce a sheet that exhibits excellent image adhesion and weather resistance.

  The present invention has been made to solve such a problem, and is decorated by printing an image by an inkjet method on a substrate containing a fluororesin, and has excellent image adhesion. And it aims at providing the laminated sheet which shows a weather resistance.

  The laminated sheet of the present invention that solves the above problems mainly includes the following configurations.

  (1) A substrate and an inkjet image layer formed on the substrate, wherein the substrate is a single layer or a multilayer, includes a first fluororesin, and the inkjet image layer includes A water contact angle of a printed surface on which the inkjet image layer is formed in the base material is a layer provided with a fluororesin ink containing a second fluororesin that is the same as or different from the first fluororesin, Laminated sheet that is ~ 75 °.

  According to such a configuration, the laminated sheet is formed with an inkjet image layer in which the fluororesin ink containing the second fluororesin is applied to the base material containing the first fluororesin. Moreover, the water contact angle of the printing surface in which an inkjet image layer is formed is 50-75 degrees. Such a laminated sheet is decorated by printing an image on a substrate containing a fluororesin by an inkjet method, and exhibits excellent image adhesion and weather resistance.

  (2) The laminated sheet according to (1), wherein an abundance ratio (O / C) of oxygen O and carbon C on the printed surface is 0.05 to 0.5.

  According to such a configuration, the fluororesin ink is not easily repelled and easily applied to the printing surface where the abundance ratio (O / C) of oxygen O to carbon C on the surface is in the above range. Moreover, the obtained inkjet image layer is excellent in adhesiveness.

  (3) The laminated sheet according to (1) or (2), wherein the base material includes a fluororesin layer including the first fluororesin, and the printing surface is a surface formed on the fluororesin layer. .

  According to such a configuration, the laminated sheet has the inkjet image layer formed on the fluororesin layer. Even in such a case, the laminated sheet exhibits excellent image adhesion.

  (4) The second fluororesin in the fluororesin ink is a copolymer of fluoroethylene and vinyl ether, has a hydroxyl value of 20 to 100 mgKOH / g, and an acid value of 5 mgKOH / g or less. The laminated sheet according to any one of 1) to (3).

  According to such a configuration, the fluororesin ink is not easily repelled on the base material containing the first fluororesin and is easily applied. Moreover, the obtained inkjet image layer is excellent in adhesiveness.

  (5) The fluororesin ink contains an isocyanate-based curing agent, and a ratio (NCO / OH ratio) of OH of the copolymer of fluoroethylene and vinyl ether and NCO of the isocyanate-based curing agent in the fluororesin ink. ) Is 0.01 to 2.0, the laminated sheet according to (4).

  According to such a configuration, the obtained inkjet image layer has excellent adhesion.

  ADVANTAGE OF THE INVENTION According to this invention, it can decorate by printing an image with the inkjet system with respect to the base material containing a fluororesin, and can provide the lamination sheet which shows the outstanding image adhesiveness and weather resistance. .

<Laminated sheet>
The laminated sheet of one embodiment of the present invention includes a base material and an inkjet image layer formed on the base material. The base material is a single layer or a multilayer and includes the first fluororesin. The inkjet image layer is a layer provided with a fluororesin ink containing a second fluororesin that is the same as or different from the first fluororesin. The water contact angle of the printing surface in which an inkjet image layer is formed among base materials is 50-75 degrees. Each will be described below.

(Base material)
The base material of a laminated sheet should just contain the 1st fluororesin, and is not specifically limited. The first fluororesin is not particularly limited. For example, the first fluororesin includes tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorotrifluoroethylene (PCTFE), Examples thereof include polytetrafluoroethylene (PTFE), ethylene-chlorotrifluoroethylene copolymer (ETCFE), and ethylene-tetrafluoroethylene copolymer (ETFE). Among these, the first fluororesin is preferably PVDF or ETFE because it is relatively easy to control the surface state of the printing surface.

  The substrate may be a single layer or a multilayer.

When the base material is a single layer When the base material is a single layer, the base material may be constituted by a single-layer fluororesin layer formed with the first fluororesin, and the first fluororesin It may be a single resin layer (fluorine resin-containing layer) made of a copolymer of and other resins. Moreover, the base material may be an embodiment in which the fiber sheet is impregnated with the first fluororesin or a copolymer of the first fluororesin and another resin.

  Resins other than the first fluororesin are not particularly limited. For example, other resins are poly (meth) methyl acrylate (PMMA), poly (meth) ethyl acrylate, poly (meth) acrylate propyl, poly (meth) acrylate butyl, (meth) acrylic acid. Methyl- (meth) butyl acrylate copolymer, (meth) ethyl acrylate- (meth) butyl acrylate copolymer, ethylene- (meth) methyl acrylate copolymer, styrene-methyl (meth) acrylate copolymer An acrylic resin such as a (meth) acrylic ester such as a polymer, a polycarbonate (PC) resin, a polyethylene terephthalate (PET) resin, an acrylonitrile-butadiene-styrene copolymer (ABS) resin, and the like. Among these, other resins are preferably PMMA and PET because they are highly transparent and have relatively good weather resistance.

  When the substrate is a single layer made of the first fluororesin, the printed surface of the substrate (the surface on which an inkjet image layer described later is formed) is the surface formed on the fluororesin layer made of the first fluororesin It is. Moreover, such a printing surface has a water contact angle of 50 to 75 °, preferably 50 to 70 °. The water contact angle can be measured by using, for example, a contact angle meter (portable contact angle meter PG-X + manufactured by Fibro System AB). When the water contact angle is in the above range, such a substrate is excellent in ink wettability and adhesion. As a result, the laminated sheet can be decorated by printing an image on a substrate containing a fluororesin by an inkjet method, and exhibits excellent image adhesion and weather resistance.

  When the substrate is a single layer made of the first fluororesin, the water contact angle may be 50 to 75 °. That is, when the water contact angle of the surface (printing surface) of the original fluororesin layer is 50 to 75 °, an inkjet image layer to be described later can be formed as it is on the base material provided with such a fluororesin layer. On the other hand, when the water contact angle of the printing surface of the original fluororesin layer is outside the range of 50 to 75 ° (for example, 90 °), the printing surface of such a fluororesin layer has a water contact angle of 50 to 75. Can be adjusted to The method for adjusting the water contact angle to the above range is not particularly limited. As an example, the water contact angle of the printing surface can be adjusted by performing treatment such as Na etching treatment, corona treatment, plasma treatment, etc. on the printing surface.

  The abundance ratio (O / C) of oxygen O to carbon C on the printed surface is preferably adjusted to be 0.05 to 0.5, and is 0.06 to 0.3. It is more preferable that the adjustment is performed. Since the abundance ratio (O / C) of oxygen O and carbon C is adjusted to the above range, the fluororesin layer is applied because the fluororesin ink is hardly repelled when forming an inkjet image layer described later. Cheap. Moreover, the obtained inkjet image layer is excellent in adhesiveness. In this embodiment, the abundance ratio (O / C) of oxygen O to carbon C is, for example, using a photoelectron spectrometer (XPS (ESCA), JPS-9010JEOL manufactured by JEOL Ltd.), and X-ray photoelectron It can be calculated from the narrow spectrum by spectroscopy.

  In the case where the substrate contains a resin other than the first fluororesin, the content of the first fluororesin in the substrate is not particularly limited. If an example is given, it is preferable that it is 50 mass% or more in a base material, and, as for solid content conversion, it is more preferable that it is 70 mass% or more in a base material. Moreover, it is preferable that it is 95 mass% or less in a base material, and, as for a 1st fluororesin, it is more preferable that it is 90 mass% or less in conversion of solid content. When the content of the first fluororesin in the substrate is within the above range, the substrate can exhibit excellent weather resistance. Moreover, the base material can contain other resin mentioned above besides the 1st fluororesin. Such other resins can exhibit excellent image adhesion when an inkjet image layer described later is formed. Therefore, the obtained laminated sheet exhibits excellent weather resistance as well as excellent image adhesion due to the first fluororesin. In this case, the base material may include a polymer alloy in which the first fluororesin and the other resin are chemically mixed, or a mixture in which the first fluororesin and the other resin are physically mixed. May be included.

  Further, in the case where the base material contains a resin other than the first fluororesin, the surface of the base material (printing surface on which an inkjet image layer to be described later is formed) The abundance ratio of the resin may be adjusted to increase. By making such adjustment, in addition to the excellent weather resistance by the first fluororesin, the base material has excellent adhesion to the inkjet image layer due to more other resins present on the surface. Easy to show.

  Furthermore, when the base material is an embodiment in which the fiber sheet is impregnated with the first fluororesin or a copolymer of the first fluororesin and another resin, the fibers constituting the fiber sheet are not particularly limited. For example, the fibers constituting the fiber sheet are various natural fibers, chemical fibers, metal fibers, inorganic fibers, and the like. Natural fibers are wood pulp fibers, kenaf, hemp, bamboo fibers and the like. Chemical fiber is polyester fiber such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PTT (polytributylene terephthalate), acrylic fiber, vinylon fiber, rayon fiber, aramid fiber, phenol fiber, fluorine fiber. Etc. The metal fiber is glass fiber, carbon fiber, stainless steel or the like. Inorganic fibers are silica fibers, rock wool, slag wool, alumina fibers, ceramic fibers, and the like. The first fluororesin and other resins are melted as necessary to prepare a resin solution. The base material is produced by impregnating a fiber sheet with a resin solution. In this embodiment, the fiber sheet impregnated with the resin is handled as a single-layer base material in principle. On the other hand, when a resin layer having a predetermined thickness is formed on the surface of the fiber sheet by impregnating the resin, such a substrate is a multilayer composed of the fiber sheet impregnated with the resin and the resin layer. It may be handled as a base material.

  When the substrate is a single layer, the thickness of the substrate is not particularly limited. As an example, the thickness of the base material is preferably 10 μm or more, and more preferably 50 μm or more. Further, the thickness of the substrate is preferably 1000 μm or less, and more preferably 500 μm or less. When the thickness of the base material is within the above range, the base material is easily transported when the ink jet image layer is formed.

When the substrate is a multilayer When the substrate is a multilayer, the substrate is a multilayer fluorine in which two or more single-layer fluororesin layers on which the first fluororesin is formed are laminated. A multi-layer resin that may be composed of a resin layer and in which a single-layer fluororesin layer on which a first fluororesin is formed and a resin layer (other resin layer) made of another resin are overlapped It may be composed of layers. Further, the base material may be an embodiment in which a fiber sheet is impregnated or coated with a first fluororesin or a copolymer of the first fluororesin and another resin.

  Other resin layers are not particularly limited. For example, the other resin layer is made of the other resin described above. In the laminated sheet of the present embodiment, the substrate is preferably composed of a plurality of resin layers, and the printing surface on which an inkjet image layer described later is formed is a surface formed on another resin layer. According to such an aspect, in the laminated sheet, in addition to the excellent weather resistance due to the first fluororesin included in the fluororesin layer, the base material has an inkjet image layer formed by the other resin layers constituting the printing surface. Easy to show excellent adhesion.

  When a base material is a multilayer, a water contact angle should just be 50-75 degrees. That is, when the water contact angle of the original printing surface is 50 to 75 °, an inkjet image layer to be described later can be formed as it is on the base material provided with such a printing surface. On the other hand, when the water contact angle of the original printing surface is outside the range of 50 to 75 ° (for example, 90 ° or the like), such a printing surface can be adjusted so that the water contact angle is 50 to 75 °. When the base material is a multilayer, the base material may adopt, for example, the above-described other resin layer as a layer constituting the printing surface, and the above-described fluororesin layer as a layer not constituting the printing surface. it can. In this case, the other resin layer may have an original water contact angle of 50 to 75 °. Therefore, it is not essential to adjust the water contact angle on such a printing surface, and an inkjet image layer described later can be formed as it is. On the other hand, when the water contact angle of the other resin layer is outside the range of 50 to 75 °, the water contact angle of the printing surface can be adjusted by the above-described treatment. In any case, the laminated sheet exhibits sufficient weather resistance due to the fluororesin layer constituting the base material, and the adhesiveness of the inkjet image layer is excellent due to the printing surface with the water contact angle adjusted appropriately.

  Furthermore, when the base material is an embodiment including a fiber sheet, the fibers constituting the fiber sheet are not particularly limited. The fiber which comprises a fiber sheet can use the fiber similar to the fiber mentioned above in relation to the base material of a single layer.

  When the base material is a multilayer, the base material only needs to contain the first fluororesin in any layer. As long as this is the case, the fiber sheet not impregnated with the resin, the fiber sheet impregnated with the resin, A single-layer fluororesin layer on which the first fluororesin is formed, a multi-layer fluororesin layer in which two or more single-layer fluororesin layers are stacked, and another resin layer can be combined. . Moreover, the base material which is a multilayer may be produced for the fiber sheet by applying the first fluororesin or other resin.

  When the substrate is a multilayer, the thickness of the substrate is not particularly limited. As an example, the thickness of the base material is preferably 10 μm or more, and more preferably 50 μm or more. Further, the thickness of the substrate is preferably 1000 μm or less, and more preferably 500 μm or less. When the thickness of the base material is within the above range, the base material is easily transported when the ink jet image layer is formed.

  Returning to the description of the entire substrate, the substrate may contain a weather resistance improver (for example, an ultraviolet absorber, a light stabilizer, etc.) in addition to the above components.

-Ultraviolet absorber An ultraviolet absorber is mix | blended suitably, in order to improve the weather resistance of a base material. The ultraviolet absorber is not particularly limited. For example, the ultraviolet absorber is a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, a triazine derivative, a salicylic acid derivative, or the like. Benzotriazole-based ultraviolet absorbers include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-tert-butylphenyl) benzotriazole, 2- (2′- Hydroxy-5′-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-3) '-Tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- ( 2'-hydroxy-3 ', 5'-di-tert-amylphenyl) benzotriazole, 2- (2'-hydroxy-4'-octylphenyl) benzo Riazole, 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole, 2-{(2′-hydroxy-3 ′, 3 ″, 4 ″, 5 ″, 6 ″ -tetrahydro Phthalimidomethyl) -5′-methylphenyl} benzotriazole and the like. Benzophenone ultraviolet absorbers include 2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy -4-dodecyloxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4 -Methoxy-5-sulfobenzophenone and the like are exemplified. The triazine derivative is 2- [4-{(2-hydroxy-3-dodecyloxy-propyl) oxy} -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5- Triazine, 2- [4-{(2-hydroxy-3-tridecyloxy-propyl) oxy} -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- {4- (octyl-2-methylethanoate) oxy-2-hydroxyphenyl-4,6- {bis (2,4-dimethylphenyl)}-1,3,5-triazine, tris [2,4 , 6- [2- {4- (octyl-2-methylethanoate) oxy-2-hydroxyphenyl}]]-1,3,5-triazine and the like. Examples of the salicylic acid derivative include phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, p- (1,1,3,3-tetramethylbutyl) phenyl salicylate and the like. An ultraviolet absorber may be used in combination.

  Content in case an ultraviolet absorber is mix | blended is not specifically limited. For example, the content of the ultraviolet absorber is preferably 0.01% by mass or more, and more preferably 0.1% by mass or more in the base material. Moreover, it is preferable that it is 10 mass% or less in a base material, and, as for content of a ultraviolet absorber, it is more preferable that it is 5 mass% or less. When the content of the ultraviolet absorber is within the above range, the base material is likely to have improved weather resistance.

-Light stabilizer A light stabilizer is suitably mix | blended in order to improve the weather resistance of a base material. The light stabilizer is not particularly limited. As an example, the light stabilizer is a hindered amine light stabilizer. The hindered amine light stabilizers are 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6,6- Tetramethyl-4-piperidylbenzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (1 -Undecyloxy-2,2,6,6-tetramethyl-4-piperidyl) carbonate, tetrakis (2,2,6,6-tetramethyl-4-piperidylbutanetetracarboxylate, tetrakis (1,2,2) , 6,6-pentamethyl-4-piperidylbutanetetracarboxylate, bis (2,2,6,6-tetramethyl-4-piperidyl) .di (tri Syl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) di (tridecyl) -1,2,3,4-butanetetra Carboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2-butyl-2- (3,5-ditert-butyl-4-hydroxybenzyl) malonate, 1- (2- Hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / diethyl succinate polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / Dibromoethane polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate, 1,6 -Screw ( , 2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-tert-octylamino-s-triazine polycondensate, 1,5,8,12-tetrakis [2,4 -Bis (N-butyl-N- (2,2,6,6-tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] -1,5,8,12-tetraazadodecane, 1 , 5,8,12-tetrakis [2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazin-6-yl]- 1,5,8,12-tetraazadodecane, 1,6,11-tris [2,4-bis (N-butyl-N- (2,2,6,6-tetramethyl-4-piperidyl) amino) -S-triazin-6-ylaminoundecane, 1,6,11-to Lis [2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazin-6-ylaminoundecane, bis (1-octyloxy -2,2,6,6-tetramethyl-4-piperidyl) -decandioate. A light stabilizer may be used in combination.

  Content in case a light stabilizer is mix | blended is not specifically limited. For example, the content of the light stabilizer in the substrate is preferably 0.01% by mass or more, and more preferably 0.1% by mass or more. Further, the content of the light stabilizer in the substrate is preferably 10% by mass or less, and more preferably 5% by mass or less. When the content of the light stabilizer is within the above range, the substrate is likely to improve the weather resistance.

(Inkjet image layer)
The inkjet image layer is a layer formed on the above-described base material, and is a layer provided with a fluororesin ink containing a second fluororesin that is the same as or different from the first fluororesin.

-Fluororesin ink The fluororesin ink contains a second fluororesin. The second fluororesin is not particularly limited. The second fluororesin may be the same as or different from the first fluororesin described above. Further, the fluororesin ink may be water-based fluororesin ink in which the second fluororesin is dispersed in water or a water-soluble organic solvent as a solvent, and the second fluororesin is dissolved in other organic solvent. Water-based fluororesin ink may be used.

  A suitable second fluororesin is, for example, a copolymer of various fluorine-containing monomers and a vinyl monomer. Among the vinyl monomers, the second fluororesin is preferably a copolymer with vinyl ether. The second fluororesin is more preferably a copolymer of fluoroethylene and vinyl ether described later.

  Examples of the fluorine-containing monomer include tetrafluoroethylene, chlorotrifluoroethylene, trichlorofluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl fluoride, and trifluoromethyltrifluoroethylene. Among these, the fluorine-containing monomer is preferably fluoroethylene, more preferably tetrafluoroethylene or chlorotrifluoroethylene, from the viewpoint of obtaining a laminated sheet having an inkjet image layer exhibiting excellent weather resistance. .

  Examples of vinyl monomers include nonionic monoethylenically unsaturated monomers and bifunctional vinyl monomers. Examples of the nonionic monoethylenically unsaturated monomer include styrene, vinyl toluene, ethylene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth) acrylamide, (meth) acrylic acid ester, and the like. As (meth) acrylic acid ester, methyl acrylate, methyl methacrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxyethyl methacrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, lauryl Examples include (meth) acrylate, oleyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate and the like. Examples of the bifunctional vinyl monomer include divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butane-diol dimethacrylate, diethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and the like.

  Examples of vinyl ether include ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, cyclohexanedimethanol divinyl ether, trimethylolpropane tri Di- or trivinyl ether compounds such as vinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexane dimethanol monovinyl ether, n-propyl vinyl ether Ether, isopropyl vinyl ether, isopropenyl ether -o- propylene carbonate, dodecyl vinyl ether, diethylene glycol monovinyl ether, and octadecyl vinyl ether are exemplified.

  The copolymerization ratio of the fluorine-containing monomer and the vinyl monomer is not particularly limited. As an example, the copolymerization ratio is fluorine-containing monomer: vinyl monomer = 3 to 1: 1 to 2 (weight ratio). When the copolymerization ratio is within such a range, the obtained inkjet image layer tends to exhibit excellent weather resistance. The polymerization method is not particularly limited. As an example, the polymerization method is solution polymerization, suspension polymerization, bulk polymerization, emulsion polymerization and the like.

The obtained second fluororesin may be an alternating copolymer, a block copolymer, a random copolymer, or a graft copolymer. Among these, it is preferable that the second fluororesin is an alternating copolymer of fluoroethylene and a vinyl monomer. The ink jet image layer containing such a second fluororesin is further excellent in weather resistance. In the present embodiment, the “alternate copolymer” refers to a bond between a fluoroethylene unit and a vinyl monomer unit, a bond between a fluoroethylene unit and a fluoroethylene unit, and a vinyl monomer unit and a vinyl monomer unit. Means a copolymer containing much more than the sum of the bonds. Specifically, the alternating copolymer of this embodiment preferably contains 90 to 100 mol% of a bond between a fluoroethylene unit and a vinyl monomer unit. In the present embodiment, the alternating copolymer may include a small number of random bond portions or block bond portions. Moreover, the said coupling | bonding can be distinguished, for example by ¹ H NMR measurement, ²⁹ Si NMR measurement, etc. For the analysis method of alternating copolymerization, for example, Journal of Applied Polymer Science, Vol. 106, 1007-1013 (2007) can be referred to.

  The second fluororesin of this embodiment preferably has a hydroxyl value of 20 mgKOH / g or more, and more preferably 30 mgKOH / g or more. Further, the second fluororesin preferably has a hydroxyl value of 100 mgKOH / g or less, more preferably 80 mgKOH / g or less. When the hydroxyl value is within the above range, the ink jet image layer is excellent in curability, and the fluororesin ink is more excellent in ejection stability during ink jet printing. When the hydroxyl value is less than 20 mgKOH / g, it tends to hardly react with the curing agent. On the other hand, when the hydroxyl value exceeds 100 mgKOH / g, the dispersion of the fluororesin ink tends to become unstable, and the ejection stability tends to be lowered. In the present embodiment, the hydroxyl value represents the number of mg of potassium hydroxide required to neutralize acetic acid bonded to a hydroxyl group when 1 g of a sample (solid content of resin) is acetylated, It is a value measured by a method according to the method described in JIS K 0070.

  The second fluororesin preferably has an acid value of 5 mgKOH / g or less, and more preferably 4 mgKOH / g or less. When the acid value is 5 mgKOH / g or less, the fluororesin ink is easy to stabilize the dispersion and has excellent ejection stability. On the other hand, when the acid value exceeds 5 mgKOH / g, the fluororesin ink tends to be unstable in the dispersion system and tends to lower the ejection stability. In addition, in this embodiment, an acid value represents the mass (mg) of potassium hydroxide required in order to neutralize the acidic component contained in 1g of samples (solid content of resin), and is described in JIS K0070. It is a value measured by a method according to the method.

  The second fluororesin of this embodiment is preferably a solvent soluble type. Specifically, in terms of solid content, the second fluororesin preferably has a solubility in diethylene glycol diethyl ether of 500 (g / L) or more, and more preferably 1000 (g / L) or more. When the solubility of the second fluororesin in the glycol ether solvent is within the above range, the fluororesin ink is less likely to cause reprecipitation of the fluororesin in the long term, and the ejection stability during ink jet printing is more excellent.

  In addition, the second fluororesin of the present embodiment preferably has a solubility in water of 50 (g / L) or less, more preferably 30 (g / L) or less in terms of solid content. Thereby, the laminated sheet obtained using such a fluororesin ink has good water resistance and more excellent weather resistance. On the other hand, when the solubility in water exceeds 50 (g / L), the laminated sheet obtained using such a fluororesin ink tends to have poor water resistance.

  The 2nd fluororesin of this embodiment may be used in the state disperse | distributed or melt | dissolved in the predetermined | prescribed solvent, and may be used in the solvent-free state (namely, solid-semi-solid form) which does not contain a solvent. . However, if the second fluororesin dispersed or dissolved in the solvent is contained in the fluororesin ink depending on the type of the solvent, the head may be damaged during ink jet printing. Therefore, it is preferable that the second fluororesin of the present embodiment does not contain a solvent that is not excellent in head suitability, and more preferably is in a solvent-free state. Such a solvent-free fluororesin originally does not contain a solvent that is not excellent in head suitability, so that it is difficult to damage the head of the ink jet recording apparatus during ink jet printing.

  The weight average molecular weight (Mw) of the second fluororesin is not particularly limited. As an example, Mw is preferably 5000 or more, and more preferably 8000 or more. Mw is preferably 50000 or less, and more preferably 40000 or less. When Mw is within the above range, the second fluororesin is easily dissolved in the solvent. Further, the fluororesin ink has improved drying properties and excellent ejection stability during ink jet printing. Furthermore, the obtained inkjet image layer has little surface stickiness, and has excellent anti-blocking properties when the laminated sheets are stacked. When Mw is less than 5000, the obtained inkjet image layer tends to be sticky, and the anti-blocking property tends to decrease. On the other hand, when Mw exceeds 50000, the solubility of the second fluororesin tends to decrease, or the ejection stability of the fluororesin ink during ink jet printing tends to decrease. In the present embodiment, Mw is a value measured by, for example, GPC (gel permeation chromatography), and can be measured using a high-speed GPC device (HLC-8120GPC manufactured by Tosoh Corporation).

  The content of the second fluororesin in the fluororesin ink is not particularly limited. For example, in terms of solid content, the second fluororesin is preferably 2% by mass or more, and more preferably 5% by mass or more in the fluororesin ink. Further, the second fluororesin is preferably 40% by mass or less, more preferably 30% by mass or less in the fluororesin ink. When the content of the second fluororesin is 2% by mass or more, the fluororesin ink tends to be excellent in ejection stability during ink jet printing. On the other hand, when the content of the second fluororesin exceeds 40% by mass, the viscosity of the fluororesin ink tends to increase, and the ejection stability during ink jet printing tends to decrease.

(Color material)
The fluororesin ink that forms the inkjet image layer preferably contains a color material. The color material may be various inorganic pigments or organic pigments. Inorganic pigments include oxides, composite oxides, hydroxides, sulfides, ferrocyanides, chromates, carbonates, silicates, phosphates, carbons (carbon black), Examples thereof include metal powders. Organic pigments include nitroso, dyed lakes, azo lakes, insoluble azos, monoazos, disazos, condensed azos, benzimidazolones, phthalocyanines, anthraquinones, perylenes, quinacridones, dioxazines, Illustrative are isoindolines, azomethines, pyrrolopyrroles and the like. These may be used in combination. Among these, the fluororesin ink of the present embodiment preferably contains an inorganic pigment as a color material from the viewpoint that color fading due to deterioration of the color material is difficult to occur.

  The content of the color material is not particularly limited. As an example, the content of the color material is preferably 0.01% by mass or more, and more preferably 0.1% by mass or more in the fluororesin ink. Further, the content of the color material is preferably 30% by mass or less, and more preferably 20% by mass or less in the fluororesin ink. When the content of the coloring material is less than 0.01% by mass, there is a tendency that sufficient coloring is not performed. On the other hand, when the content of the color material exceeds 30% by mass, the viscosity of the fluororesin ink tends to increase, and the ejection stability during ink jet printing tends to decrease.

(Optional component)
The fluororesin ink can contain an optional component well known in the field of inkjet ink, in addition to the above-described second fluororesin and the color material suitably contained. For example, optional components include various binder resins (excluding fluororesins), various solvents, curing agents, curing catalysts, weather resistance improvers (for example, ultraviolet absorbers, light stabilizers, etc.), slip agents (leveling agents). ), Dispersant, polymerization accelerator, polymerization inhibitor, penetration accelerator, wetting agent (humectant), fixing agent, antifungal agent, antiseptic, antioxidant, chelating agent, thickener and the like.

-Binder resin Binder resin can be contained, for example, in order to adjust the viscosity of the fluororesin ink, or to adjust the hardness or shape of the resulting inkjet image layer or laminated sheet.

  The kind of binder resin is not specifically limited. For example, the binder resin is epoxy resin, diallyl phthalate resin, silicone resin, phenol resin, unsaturated polyester resin, polyimide resin, polyurethane resin, melamine resin, urea resin, ionomer resin, ethylene ethyl acrylate resin, acrylonitrile acrylate styrene. Copolymer resin, acrylonitrile styrene resin, acrylonitrile chlorinated polyethylene styrene copolymer resin, ethylene vinyl acetate resin, ethylene vinyl alcohol copolymer resin, acrylonitrile butadiene styrene copolymer resin, vinyl chloride resin, chlorinated polyethylene resin, polyvinylidene chloride resin, acetic acid Cellulose resin, polyoxymethylene resin, polyamide resin, polyarylate resin, thermoplastic polyurethane elastomer, polyether ester Terketone resin, polyether sulfone resin, polyethylene, polypropylene, polycarbonate resin, polystyrene, polystyrene maleic acid copolymer resin, polystyrene acrylic acid copolymer resin, polyphenylene ether resin, polyphenylene sulfide resin, polybutadiene resin, polybutylene terephthalate resin, acrylic resin, Examples include methacrylic resin, methylpentene resin, polylactic acid, polybutylene succinate resin, butyral resin, formal resin, polyvinyl alcohol, polyvinyl pyrrolidone, ethyl cellulose, carboxymethyl cellulose, gelatin, and copolymer resins thereof. The binder resin can be appropriately selected in consideration of film strength, viscosity, residual viscosity of the fluororesin ink, dispersion stability of the color material, thermal stability, non-coloring property, water resistance, and chemical resistance. The binder resin may be used in combination.

  Among these, the binder resin is preferably an acrylic resin, a vinyl chloride resin, or a silicone resin from the viewpoint of excellent heat resistance and weather resistance.

  The acrylic resin is not particularly limited. As an example, the acrylic resin is exemplified by a polymer of acrylic ester (acrylate) or methacrylic ester (methacrylate). More specifically, the acrylic resin is an acrylic acid alkyl ester such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate; methyl methacrylate, methacryl Alkyl methacrylates such as ethyl acetate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate; 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, etc. Hydroxyl group-containing acrylic acid esters; polymers such as hydroxy group-containing methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, etc. . These may be used in combination.

  The weight average molecular weight (Mw) of the acrylic resin is not particularly limited. For example, Mw is preferably 5000 or more, and more preferably 10,000 or more. Mw is preferably 100,000 or less, and more preferably 50,000 or less. When Mw is within the above range, the fluororesin ink containing such an acrylic resin has excellent ejection stability during ink jet printing.

  The vinyl chloride resin is not particularly limited. As an example, examples of the vinyl chloride resin include copolymers of vinyl chloride and other monomers such as vinyl acetate, vinylidene chloride, acrylic acid, maleic acid, vinyl alcohol, and the like. Among these, it is preferable that a vinyl chloride resin is a copolymer (vinyl chloride vinyl acetate copolymer) containing the structural unit derived from vinyl chloride and vinyl acetate.

  A vinyl acetate vinyl chloride copolymer can be obtained, for example, by suspension polymerization. It is preferable that a vinyl chloride vinyl acetate copolymer contains 70-90 mass% of vinyl chloride units. If it is the said range, since the polyvinyl acetate vinyl copolymer will melt | dissolve stably in a fluororesin ink, long-term storage stability is excellent. In addition, the fluororesin ink has excellent ejection stability.

  The vinyl acetate vinyl acetate copolymer may be provided with other structural units in addition to the vinyl chloride unit and the vinyl acetate unit, if necessary. For example, examples of other structural units include carboxylic acid units, vinyl alcohol units, and hydroxyalkyl acrylate units. Among these, it is preferable that another structural unit is a vinyl alcohol unit.

  The number average molecular weight (Mn) of the vinyl chloride resin is not particularly limited. For example, Mn of the vinyl chloride resin is preferably 10,000 or more, and more preferably 12000 or more. Further, Mn is preferably 50000 or less, and more preferably 42000 or less. Mn can be measured by GPC and can be obtained as a relative value in terms of polystyrene.

  The silicone resin is not particularly limited. For example, silicone resins include methyl straight silicone resin (polydimethylsiloxane), methylphenyl straight silicone resin (polydimethylsiloxane in which a part of methyl group is substituted with phenyl group), acrylic resin-modified silicone resin, polyester Examples thereof include a resin-modified silicone resin, an epoxy resin-modified silicone resin, an alkyd resin-modified silicone resin, and a rubber-based silicone resin. These may be used in combination. Among these, the silicone resin is preferably a methyl-based straight silicone resin, a methylphenyl-based straight silicone resin, or an acrylic resin-modified silicone resin.

  The silicone resin may be dissolved in an organic solvent or the like. Examples of the organic solvent include xylene and toluene.

  The number average molecular weight (Mn) of the silicone resin is not particularly limited. As an example, the Mn of the silicone resin is preferably 10,000 or more, and more preferably 20,000 or more. Further, Mn is preferably 5000000 or less, and more preferably 3000000 or less. Mn can be measured by GPC and can be obtained as a relative value in terms of polystyrene.

  Returning to the description of the entire binder resin, the content of the binder resin is not particularly limited. As an example, the binder resin is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass or more in the fluororesin ink in terms of solid content. . Moreover, it is preferable that binder resin is 40 mass% or less in a fluororesin ink, It is more preferable that it is 30 mass% or less, It is further more preferable that it is 25 mass% or less. When the content of the binder resin is less than 1% by mass, it is difficult to obtain desired performance as a binder, and image adhesion to a substrate tends to decrease. On the other hand, when the content of the binder resin exceeds 40% by mass, the viscosity of the fluororesin ink tends to increase, and the ejection stability during ink jet printing tends to decrease.

Solvent The solvent is a liquid component for dissolving or dispersing the binder resin in the fluororesin ink. The kind of solvent is not specifically limited. For example, the solvent is water (ion exchange water, distilled water, etc.), glycol ether solvent, acetate solvent, alcohol solvent, ketone solvent, ester solvent, hydrocarbon solvent, fatty acid ester solvent, Aromatic solvents and the like. These may be used in combination. Among these, the solvent of the present embodiment preferably includes at least one of a glycol ether solvent and an acetate solvent. Both the glycol ether solvent and the acetate solvent have a low viscosity and a relatively high boiling point. Therefore, the fluororesin ink containing these as a solvent has a further improved drying property, and is more excellent in ejection stability during ink jet printing.

  Glycol ether solvents are ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono (iso) propyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, propylene glycol Monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n -Butyl ether, triethylene glycol monomethyl ester Tellurium, triethylene glycol monoethyl ether, triethylene glycol mono-n-propyl ether, triethylene glycol mono-n-butyl ether, tripropylene glycol monoethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono- n-butyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol ethyl methyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, tri Chi glycol butyl methyl ether, dipropylene glycol dimethyl ether, tripropylene glycol dimethyl ether and the like.

  Acetate solvents include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monoisopropyl ether acetate, ethylene glycol mono-n-butyl ether acetate, ethylene glycol mono-sec-butyl ether acetate, Ethylene glycol monoisobutyl ether acetate, ethylene glycol mono-tert-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monoisopropyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol Mono-n-butyl ether acetate, propylene glycol mono-sec-butyl ether acetate, propylene glycol monoisobutyl ether acetate, propylene glycol mono-tert-butyl ether acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-ethoxybutyl Acetate, 3-methyl-3-propoxybutyl acetate, 3-methyl-3-isopropoxybutyl acetate, 3-methyl-3-n-butoxyethyl acetate, 3-methyl-3-isobutoxybutyl acetate, 3-methyl Alkylene glycol monoalkyl ether acetates such as -3-sec-butoxy butyl acetate and 3-methyl-3-tert-butoxy butyl acetate, ethylene glycol Diacetate, diethylene glycol diacetate, triethylene glycol diacetate, propylene glycol diacetate, dipropylene glycol diacetate, tripropylene glycol diacetate, and the like.

  Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, and the like.

  Examples of the ketone solvent include ketones such as acetone and diacetone alcohol, and keto alcohols.

  The solvent of this embodiment preferably has a boiling point of 150 ° C. or higher, and more preferably 180 ° C. or higher. Further, the solvent preferably has a boiling point of 300 ° C. or lower, and more preferably 280 ° C. or lower. When the boiling point is within the above range, the fluororesin ink has more improved drying properties and more excellent ejection stability during ink jet printing. In addition, with the fluororesin ink, a clear inkjet image layer with little bleeding is easily formed. When the boiling point of the solvent is less than 150 ° C., the fluororesin ink tends to dry near the head nozzle, and the ejection stability tends to decrease. On the other hand, when the boiling point of the solvent exceeds 300 ° C., the fluororesin ink is difficult to dry, and the drying process at the time of forming the inkjet image layer tends to take time. Further, the obtained ink jet image layer is likely to blur images.

  The content of the solvent is not particularly limited. As an example, the solvent is preferably 50% by mass or more, and more preferably 60% by mass or more in the fluororesin ink. Further, the solvent is preferably 99% by mass or less, and more preferably 80% by mass or less in the fluororesin ink. When the content of the solvent is less than 50% by mass, the viscosity of the fluororesin ink tends to increase, and the ejection stability during ink jet printing tends to decrease. On the other hand, when the content of the solvent exceeds 99% by mass, the ratio of the second fluororesin that can be added to the fluororesin ink is low, and the desired performance tends to be difficult to obtain. In this embodiment, content of a solvent may be adjusted according to suitable content of an above described 2nd fluororesin. In this case, the content of the solvent is more preferably 70% by mass or more. Moreover, it is preferable that content of a solvent is 98 mass% or less, and it is more preferable that it is 95 mass% or less. When the content of the solvent is within such a range, the fluororesin ink can contain a suitable amount of the second fluororesin and the solvent.

-Curing agent A curing agent may be mix | blended in order to cure a fluororesin ink. The curing agent is not particularly limited. For example, the curing agent is a carbodiimide curing agent, an aziridine curing agent, a metal chelate curing agent, an isocyanate curing agent, a melamine curing agent, an epoxy curing agent, an oxazoline curing agent, a urea curing agent, Examples thereof include a polyamine curing agent, a polyethyleneimine curing agent, and an acrylamide curing agent. A curing agent may be used in combination. Among these, it is preferable that the hardening | curing agent contains the isocyanate type hardening | curing agent. Thereby, the ink-jet image layer obtained using such a fluororesin ink is more excellent in weather resistance.

  The isocyanate resin constituting the isocyanate-based curing agent may be a compound having two or more isocyanate groups in one molecule, and any of general-purpose type, non-yellowing type, non-yellowing type and the like can be used. Examples of the general-purpose type include tolylene diisocyanate (TDI), isocyanurate which is a trimerized product of TDI, 4,4-diphenylmethane diisocyanate (MDI), and polymeric diphenylmethane diisocyanate (polymeric MDI). Examples of the hardly yellowing type include xylylenediamine (XDI). Examples of the non-yellowing type include hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), hydrogenated XDI, and hydrogenated MDI. Among these, the curing agent preferably contains a non-yellowing type blocked isocyanate, and more preferably a non-yellowing type blocked isocyanate having an isocyanurate structure. The fluororesin ink containing such a curing agent is more excellent in curability. Further, by using such a fluororesin ink, the obtained inkjet image layer is further excellent in weather resistance. Therefore, the laminated sheet on which the inkjet image layer is formed tends to exhibit a desired color over a longer period.

In the case where an isocyanate curing agent is included as the curing agent, the fluororesin ink is a ratio of the OH of the second fluororesin and the NCO of the isocyanate curing agent (NCO / OH ratio) present in the fluororesin ink. However, it is preferable that it is 0.01-2.0, and it is more preferable that it is 0.1-1.2. As a specific example, for example, when the second fluororesin is a copolymer of fluoroethylene and vinyl ether, OH of the copolymer of fluoroethylene and vinyl ether in the fluororesin ink and the isocyanate curing agent The ratio with NCO (NCO / OH ratio) is preferably from 0.01 to 2.0, more preferably from 0.1 to 1.2. When the ratio (NCO / OH ratio) is within the above range, the obtained inkjet image layer exhibits an appropriate hardness and is easily improved in adhesion to the substrate. In the present embodiment, the NCO / OH ratio can be calculated from the following equation.
(NCO / OH ratio) = (561 / hydroxyl value of second fluororesin) × (NCO% of isocyanate curing agent / (42 × 100)) × (100 / second fluororesin amount [parts by weight]) × Isocyanate curing agent amount [parts by weight]

  The content of the curing agent is not particularly limited. Since it varies depending on the addition amount of the fluororesin, the hydroxyl value, and the acid value, it is not uniquely determined. As an example, the content of the curing agent in the fluororesin ink is preferably 0.1% by mass or more, and more preferably 1% by mass or more. The content of the curing agent is preferably 20% by mass or less, more preferably 10% by mass or less, in the fluororesin ink. When content of a hardening | curing agent is less than 0.1 mass%, it cannot fully react with a 2nd fluororesin, and there exists a tendency for desired performance not to be obtained. On the other hand, when the content of the curing agent exceeds 20% by mass, there is a risk of excessive addition to the second fluororesin, and the weather resistance of the resulting inkjet image layer tends to be lowered.

Curing catalyst As curing catalyst, organic acid salts, alcoholates and chelate compounds of metals such as tin, titanium, zirconium, iron, antimony, bismuth, manganese, zinc and aluminum; amines such as hexylamine and dodecylamine; hexyl acetate Examples include amines, amine salts such as dodecylamine phosphate; quaternary ammonium salts such as benzyltrimethylammonium acetate; alkali metal salts such as potassium acetate, and the like. More specifically, organic bismuth compounds such as bismuth octylate and bismuth neodecanoate, organic tin compounds such as dibutyltin dilaurate, dibutyltin dioctylate, dimethyltin dineodecanoate, stannous octoate, tetrabutyl titanate, tetraisopropyl titanate, di Examples thereof include organic titanium compounds such as isopropoxybis (acetylacetone) titanium and diisopropoxybis (ethylacetoacetate) titanium. These may be used in combination. In the present embodiment, the curing catalyst is preferably a tin-based compound, more preferably a dialkyltin-based compound such as dibutyltin dilaurate or dimethyltin dineodecanoate, and more preferably dibutyltin dilaurate. When dibutyltin dilaurate is contained as a curing catalyst, the resulting fluororesin ink has excellent curability.

  Content in case a curing catalyst is mix | blended is not specifically limited. For example, the content of the curing catalyst is preferably 0.001% by mass or more, and more preferably 0.01% by mass or more in the fluororesin ink. Further, the content of the curing catalyst is preferably 5% by mass or less, more preferably 3% by mass or less in the fluororesin ink. When the content of the curing catalyst is less than 0.001% by mass, the performance as a curing catalyst tends not to be sufficiently exhibited. On the other hand, when the content of the curing catalyst exceeds 5% by mass, the curability of the fluororesin ink increases, and the ejection stability during ink jet printing tends to decrease.

-Weather resistance improver A weather resistance improver (for example, an ultraviolet absorber, a light stabilizer, etc.) is preferably contained in order to improve the weather resistance of the inkjet image layer. The weather resistance improver is not particularly limited. For example, as the weather resistance improver, the weather resistance improver described above in the description of the base material can be suitably used.

-Dispersing agent A dispersing agent is contained suitably in order to disperse a coloring material. The dispersant is not particularly limited. For example, the dispersant is an anionic surfactant, a nonionic surfactant, a polymer dispersant, or the like. A dispersant may be used in combination.

  Anionic surfactants include fatty acid salts, alkyl sulfate esters, alkylbenzene sulfonates, alkyl naphthalene sulfonates, lignin sulfonates, dialkyl sulfosuccinates, alkyl phosphate ester salts, naphthalene sulfonate formalin condensates, Examples thereof include oxyethylene alkyl sulfate salts and substituted derivatives thereof.

  Nonionic surfactants are polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester, oxyethyleneoxy Examples include propylene block polymers and substituted derivatives thereof.

  A polymer dispersant having both an acid value and a base value and having an acid value larger than the base value is preferable from the viewpoint of obtaining more stable dispersion characteristics. For example, polymer dispersants are PB series manufactured by Ajinomoto Fine Techno Co., Hinoact series manufactured by Kawaken Fine Chemical Co., Solsperse Series manufactured by Nihon Lubrizol Co., Ltd., Enomoto Kasei Co., Ltd. ) DISPARLON series manufactured by BASF Japan Ltd., Efka (registered trademark) series manufactured by BASF Japan Ltd., and the like.

  The content of the dispersant is appropriately determined depending on the type and content of the color material to be dispersed. As an example, the content of the dispersant is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more with respect to 100 parts by mass of the color material. Moreover, it is preferable that it is 150 mass parts or less with respect to 100 mass parts of coloring materials, and, as for content of a dispersing agent, it is more preferable that it is 80 mass parts or less. When the content of the dispersant is less than 5 parts by mass, the color material tends to be difficult to be dispersed. On the other hand, when the content of the dispersant exceeds 150 parts by mass, the raw material cost tends to increase or the dispersion of the coloring material tends to be hindered.

  Returning to the description of the entire fluororesin ink, the viscosity of the fluororesin ink is not particularly limited. The viscosity of the fluororesin ink is preferably 5 mPa · s or more, more preferably 6 mPa · s or more at 30 ° C. Further, the viscosity of the fluororesin ink is preferably 30 mPa · s or less, more preferably 20 mPa · s or less, at 30 ° C. When the viscosity is within the above range, the fluororesin ink is excellent in ejection stability. When the viscosity of the fluororesin ink is less than 5 mPa · s, the ejection stability during ink jet printing tends to decrease. On the other hand, when the viscosity exceeds 30 mPa · s, the fluororesin ink cannot be discharged well from the head nozzle, and the discharge stability during ink jet printing tends to decrease. In the present embodiment, the viscosity can be measured using a B-type viscometer (manufactured by Toki Sangyo Co., Ltd., model number: TVB-20LT).

  The method for adjusting the viscosity within the above range is not particularly limited. For example, the viscosity can be adjusted by the amount of the second fluororesin used and the type and amount of the solvent used. The viscosity may be adjusted using a viscosity adjusting agent such as a thickener as necessary.

  The surface tension of the fluororesin ink is not particularly limited. The surface tension of the fluororesin ink is preferably 20 dyne / cm or more at 25 ° C., more preferably 22 dyne / cm or more. The surface tension of the fluororesin ink is preferably 40 dyne / cm or less, more preferably 38 dyne / cm or less at 25 ° C. When the surface tension is within the above range, the fluororesin ink has excellent ejection stability. When the surface tension is less than 20 dyne / cm, the fluororesin ink tends to be easy to bleed due to excessive wettability. On the other hand, when the surface tension exceeds 40 dyne / cm, the fluororesin ink is likely to be repelled on the surface of the substrate, and the resulting inkjet image layer tends to be unclear. In this embodiment, the surface tension can be measured using a static surface tension meter (plate method) (seller: manufactured by Kyowa Interface Science Co., Ltd., model number: CBVP-A3).

  The method for adjusting the surface tension within the above range is not particularly limited. As an example, the surface tension can be adjusted by adding an acrylic surface conditioner, a silicone surface conditioner, a fluorine surface conditioner, or the like.

  The wetting index of the inkjet image layer is not particularly limited. As an example, the wetting index of the inkjet image layer is preferably 20 dyne / cm or more, and more preferably 25 dyne / cm or more. The wetting index of the ink jet image layer is preferably 50 dyne / cm or less, and more preferably 40 dyne / cm or less. When the wetting index is within the above range, the ink jet image layer has an advantage that a uniform coating film can be easily obtained even when another ink or paint is applied to the ink jet image layer. In this embodiment, the wetting index can be measured according to the method described in JIS K 6768.

  The inkjet image layer may be further provided with a top coat that covers the inkjet image layer. The top coat is not particularly limited. For example, the topcoat may be polymethyl methacrylate, polyvinylidene fluoride, polyvinyl fluoride, polypropylene, polyethylene, polyurethane, silicone, polymethacrylate, polyacrylate, polyvinylidene fluoride, silicone hard coat, and mixtures or copolymers thereof. Etc. The laminated sheet of this embodiment is preferably provided with such a top coat when the inkjet image layer contains an organic pigment as a color material. Thereby, the laminated sheet can provide further improvement in weather resistance, scratch resistance of the printed layer, and the like.

  As described above, in the laminated sheet of the present embodiment, an ink jet image layer in which a fluororesin ink containing a second fluororesin is applied to a base material containing a first fluororesin is formed. Such a laminated sheet is decorated by printing an image on a substrate containing a fluororesin by an inkjet method, and exhibits excellent image adhesion and weather resistance.

<Method for producing laminated sheet>
The method for producing a laminated sheet according to an embodiment of the present invention mainly includes a step of forming the inkjet image layer containing the second fluororesin by applying the fluororesin ink described above on the above-described substrate by an inkjet method. Included. In addition, before forming an inkjet image layer on a base material, you may form a base layer on a base material.

(Base layer formation process)
A base layer formation process is a process of forming a base layer on a base material. The method for applying the base composition constituting the base layer onto the substrate is not particularly limited. The base layer can be formed by applying the base composition onto the substrate by spraying, roll coater, hand coating, ink jet method or the like.

  The base composition is not particularly limited. For example, the base composition is a polyester resin, polyurethane resin, acrylic resin, silicone resin, epoxy resin, alkyd resin, aminoalkyd resin, fluororesin, or the like. These may be used in combination. Among these, it is preferable that a base layer contains a fluororesin as a resin composition so that the outstanding weather resistance may be provided.

(Inkjet process)
The ink jet process is a process of applying a fluororesin ink to a base material or a base layer formed on the base material by an ink jet recording method. The method for applying the fluororesin ink is not particularly limited. Examples of such methods include a charge modulation method, a microdot method, a charge ejection control method, a continuous method such as an ink mist method, a piezo method, a pulse jet method, a bubble jet (registered trademark) method, and an electrostatic suction method. -A demand method etc. are illustrated.

  The substrate to which the fluororesin ink has been applied is then dried. Drying conditions are not particularly limited. As an example, the drying may be performed at 50 to 250 ° C. for 1 to 60 minutes. By such drying, the solvent in the fluororesin ink can be removed. Drying is preferably performed at the same time as or immediately after the fluororesin ink is applied to the substrate in order to prevent bleeding of the inkjet image layer.

  As mentioned above, according to the manufacturing method of the lamination sheet of this embodiment, an ink jet image layer is formed in the base material containing the 1st fluororesin with the fluoro ink containing the 2nd fluororesin. The obtained laminated sheet is decorated by printing an image on a substrate containing a fluororesin by an inkjet method, and exhibits excellent image adhesion and weather resistance.

  The use of the laminated sheet is not particularly limited. Since the laminated sheet exhibits excellent image adhesion and weather resistance, it is particularly suitable for applications used outdoors. For example, the laminated sheet is suitable as an agricultural material, a tent film, a building structure film, an advertisement sheet, or the like. Moreover, a lamination sheet can also be used as a lamination sheet of various base materials, for example.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to these examples.

The raw materials used are shown below.
(Base material)
-1st fluororesin PMMA / PVDF: The multilayer base material which consists of poly (meth) acrylic-acid methyl and a polyvinylidene fluoride, Denka Co., Ltd. product, DX-14S, thickness 100 micrometers
ETFE: Single-layer base material of ethylene-tetrafluoroethylene copolymer, manufactured by AGC Corporation, Aflex 100N1250NT, thickness 100 μm
PTFE: Polytetrafluoroethylene single-layer base material, Yodogawa Futec Co., Ltd. Yodoflon 4600, thickness 100 μm
(Fluoropolymer ink constituting the inkjet image layer)
Second fluororesin LF-200F: ethylene trifluoride / vinyl monomer alternating copolymer, manufactured by Asahi Glass Co., Ltd., hydroxyl value: 50 mgKOH / g, acid value: 0 mgKOH / g, Mw: 20000
Solvent DEDG: Diethylene glycol diethyl ether, glycol ether solvent, boiling point: 189 ° C., SP value: 8.6, manufactured by Nippon Emulsifier Co., Ltd. Curing agent SBN-70D: Block isocyanate, NCO%: 10.1, Asahi Kasei Chemicals -Pigment Blue Pigment: Daipyroxide Blue Sharp 9410, manufactured by Dainichi Seika Kogyo Co., Ltd. Dispersant solsperse 36000, manufactured by Nippon Lubrizol Co., Ltd.

  Using the raw materials, fluororesin inks 1 and 2 were prepared according to the formulation described in Table 1 below (unit: mass%).

(Example 1)
In accordance with the formulation shown in Table 2 below, an inkjet image layer was formed on the substrate by the following method to produce a laminated sheet.

(Formation of inkjet image layer)
An ink jet image layer was formed on the substrate according to the following ink jet conditions.
<Inkjet conditions>
Inkjet recording device: Piezo method Nozzle diameter: 40 μm
Drive voltage: 70V
Ink dot size: 30 pl
Frequency: 12kHz
Resolution: 400 x 800 dpi
Substrate temperature: 60 ° C. (warming)
Evaluation pattern: 100 mm solid pattern <drying conditions>
Heat drying (at 80 ° C for 12 hours)

(Examples 2-9, Comparative Examples 1-2)
A laminated sheet was produced in the same manner as in Example 1 except that the type of substrate, the treatment for the substrate, and the type of fluororesin ink for forming the inkjet image layer were changed to the formulation shown in Table 2. . In addition, each process with respect to a base material is as follows.

-Na etching process The base material was immersed in the sodium naphthalene complex solution (Fluorobonder E, the product made from Technos). The processing time was 10 seconds for PTFE and 60 seconds for ETFE. After the treatment, it was thoroughly washed with ethanol, then washed with warm water and dried.

-Corona treatment Using a corona treatment device (TEC-4AX, manufactured by Kasuga Electric Co., Ltd.), the discharge electrode length is 0.3 m, the discharge voltage is 100 W, the distance between the electrode and the substrate is 1 mm, and the treatment speed is 1 hour. The printed surface of the substrate was processed at 3 m, 15 m, or 30 m.

-Plasma treatment Using plasma treatment (remote atmospheric pressure plasma treatment device, manufactured by Air Water Co., Ltd.), the distance between the nozzle and the substrate is 1 mm, the treatment speed is 15 m per hour, and the printed surface of the substrate Was processed. The gas used was air.

  About the lamination sheet obtained by Examples 1-9 and Comparative Examples 1-2, it evaluated based on the following evaluation methods and evaluation criteria. The results are shown in Table 2.

<Water contact angle>
Using a portable contact angle meter PG-X + (manufactured by Fibro System AB), the contact angle when water was dropped was measured.
<O / C ratio>
Using a photoelectron spectrometer (XPS (ESCA), JPS-9010JEOL, manufactured by JEOL Ltd.), it was calculated from a narrow spectrum by X-ray photoelectron spectroscopy. AlKα was used as the X-ray source. The surface composition ratio was calculated from the narrow spectrum of C1s and C from the narrow spectrum of O1s.
<Wetted ink>
When forming the inkjet image layer, a solid pattern was printed under the above-described inkjet conditions, and it was confirmed whether or not the fluororesin ink was not repelled.
(Evaluation criteria)
○: The fluororesin ink was not repelled.
X: The fluororesin ink was repelled.
<Tape peeling>
When forming an inkjet image layer, a solid pattern was printed under the above-described inkjet conditions and dried at 80 ° C. for 12 hours, and then the print surface was confirmed to be peeled off with a tape, and the presence or absence of peeling was confirmed.
(Evaluation criteria)
○: The inkjet image layer was not peeled off.
X: The inkjet image layer was peeled off.
<Weather resistance>
Using a super UV tester (Iwasaki Electric Co., Ltd., SUV-W161), the ultra-accelerated weathering test was conducted for 6 hours with UV irradiation (UV condition 100 mW / cm ² , temperature 63 ° C., humidity 50%), and then shower 30 After 2 seconds, 2 hours of dew condensation was performed as one cycle, and the color difference after a total of 600 hours was measured.
(Color difference measurement method)
The ΔE after the test before the super accelerated weathering test of the printed matter was taken as the color difference. The color difference was measured using a spectrocolorimeter (Konica Minolta, CM-3700).
(Evaluation criteria)
A: The color difference was ΔE ≦ 3.
Δ: Color difference was 3 <ΔE ≦ 5.
X: The color difference was ΔE> 5.

  As shown in Table 2, the laminated sheets of Examples 1 to 9 are all excellent in weather resistance, and the obtained inkjet image layer is excellent when the fluororesin ink is not repelled when forming the inkjet image layer. Showed good adhesion. On the other hand, the laminated sheets of Comparative Examples 1 and 2 could not form an inkjet image because the fluororesin ink bounced when forming the inkjet image layer. Therefore, the laminated sheets of Comparative Examples 1 and 2 could not be evaluated for weather resistance. Moreover, the laminated sheet of Comparative Examples 1-2 was inferior in the adhesiveness of the obtained inkjet image layer, and was easy to peel off.

Claims (7)

A substrate and an inkjet image layer formed on the substrate;
The substrate is
Single layer or multiple layers,
Including a first fluororesin;
The inkjet image layer is a layer provided with a fluororesin ink containing a second fluororesin that is the same as or different from the first fluororesin,
The water contact angle of the printing surface in which the said inkjet image layer is formed among the said base materials is a lamination sheet which is 50 degrees or more and less than 70 degrees . The laminated sheet according to claim 1, wherein the printed surface is a surface subjected to Na etching treatment, corona treatment or plasma treatment. The laminated sheet according to claim 1 or 2 , wherein an abundance ratio (O / C) of oxygen O and carbon C on the printed surface is 0.05 to 0.5. The base material includes a fluororesin layer containing the first fluororesin,
The laminated sheet according to any one of claims 1 to 3, wherein the printed surface is a surface formed on the fluororesin layer. The second fluororesin in the fluororesin ink is
A copolymer of fluoroethylene and vinyl ether;
The hydroxyl value is 20-100 mg KOH / g,
The laminated sheet according to any one of claims 1 to 4 , wherein the acid value is 5 mgKOH / g or less. The fluororesin ink is
Containing an isocyanate curing agent,
In the fluorine resin ink, and OH of a copolymer of fluoroethylene and vinyl ethers, the ratio of NCO of the isocyanate curing agent (NCO / OH ratio) is 0.01 to 2.0, according to claim 5 The laminated sheet as described. A substrate and an inkjet image layer formed on the substrate;
The base material includes a fluororesin layer containing a first fluororesin and another resin layer containing another resin different from the fluororesin layer,
The inkjet image layer is
A layer provided with a fluororesin ink containing a second fluororesin that is the same as or different from the first fluororesin, and
Laminated to the other resin layer,
The water contact angle of the printing surface in which the said inkjet image layer is formed among the said base materials is a lamination sheet which is 50-75 degrees.