JP6810528B2 - Graphic film for license plate and license plate, and their manufacturing method - Google Patents

Description

The present disclosure relates to a graphic film for a license plate, a license plate containing the graphic film, and a method for manufacturing the same.

In recent years, a technique for adding decoration to a license plate (also referred to as a license plate; the same shall apply hereinafter in the present disclosure) has been proposed. Further, as a means for imparting decoration, a means for adopting painting or a graphic film is used.

In Patent Document 1 (Japanese Unexamined Patent Publication No. 05-155796), as a method for decorating a molded product such as a body side molding of an automobile, "a method of attaching an interior / exterior film with an adhesive to a base material after molding, and molding A method of spray-coating a paint and clear using a two-component polyurethane composed of a combination of an acrylic polyol / hexamethylene diisocyanate-based polyisocyanate as a binder on the subsequent base material is described.

Patent Document 2 (Japanese Unexamined Patent Publication No. 2008-023854) states that "a sheet-like laminate obtained by laminating a layer of water-based polyurethane and a decorative layer on a sheet of thermoplastic resin, and the water-based polyurethane is tensioned. It is a polycarbonate-based water-based polyurethane having a breaking elongation (value measured at 23 ° C. and a tensile speed of 500 mm / min using a JIS No. 2 test piece having a thickness of 0.2 mm) of 100 to 800%, and the thermoplastic resin. It is described that the "sheet-like laminate characterized by laminating the water-based polyurethane layer on the sheet by a transfer method" can be applied to the interior / exterior material of an automobile.

Japanese Unexamined Patent Publication No. 05-155796 Japanese Unexamined Patent Publication No. 2008-023854

The conventional painting method tends to cause defects due to foreign matter or coating spots, and requires a highly clean work environment and a skilled coating technique. Therefore, a simpler decoration means has been desired.

On the other hand, a graphic film provided with an adhesive layer and a decorative layer can be decorated by simply applying the film to a base material for molding and then heat-pressing, so that it is used as a simpler decorative means. There is. However, in the case of license plates, the letters are formed by stamping without heating. Since the film is less likely to flow than the press working with heating, the graphic film for the license plate requires more severe elongation characteristics than the graphic film for the press working with heating. Print compatibility and heat resistance with the baking ink used for the character part of the license plate are also required.

Conventionally, a flexible resin such as polyvinyl chloride has been adopted as a material that satisfies the elongation characteristics of a graphic film for a license plate. Since the license plate is mainly used outdoors, it is desirable that the license plate has weather resistance, stain resistance, chemical resistance, gasoline resistance, etc. for the purpose of protecting the decorative layer and the like. However, the graphic film containing a flexible resin such as polyvinyl chloride has insufficient chemical resistance and gasoline resistance, and deteriorates the decorative layer and the like located below the outermost layer side, and therefore after press working. , It was necessary to separately apply a protective coating such as urethane to the outermost surface.

In view of the above problems, an object of the present disclosure is to have chemical resistance, gasoline resistance, elongation characteristics that can follow press working without heating, which are necessary for use as a license plate, and further for baking coating and the like. It is an object of the present invention to provide a graphic film for a license plate and a license plate provided with the graphic film, which may have print compatibility with the formed ink layer.

According to one embodiment of the present disclosure, a graphic film for a license plate comprising a polyurethane surface protective layer to which a printed layer is applied, wherein the polyurethane surface protective layer is a polyol having at least either a polyester skeleton or a polycarbonate skeleton. And a reaction product with a polyfunctional aliphatic isocyanate, or a graphic film for a license plate containing an aqueous polyurethane.

According to another embodiment of the present disclosure, a license plate including the graphic film for the license plate is provided.

According to yet another embodiment of the present disclosure, a polyurethane to which a printed layer is applied, comprising a reactant of at least a polyol having either a polyester skeleton or a polycarbonate skeleton with a polyfunctional aliphatic isocyanate, or an aqueous polyurethane. A step of providing the surface protective layer and a second surface facing the first surface and the first surface on the surface protective layer side, which contains a carboxyl group-containing (meth) acrylic polymer on or above the polyurethane surface protective layer. A step of providing a decorative ink-acceptable (meth) acrylic polymer layer, a step of providing a decorative ink on the second surface of the (meth) acrylic polymer layer, and a (meth) acrylic polymer layer. A method for producing a graphic film for a license plate is provided, which comprises a step of providing an adhesive layer on or above the second surface of the surface.

According to yet another embodiment of the present disclosure, a polyurethane to which a printed layer is applied, comprising a reactant of at least a polyol having either a polyester skeleton or a polycarbonate skeleton with a polyfunctional aliphatic isocyanate, or an aqueous polyurethane. A decorative ink-acceptable group having a first surface and a second surface facing the first surface, a step of providing a surface protective layer, a step of providing a bonding layer on or above the polyurethane surface protective layer. A license including a step of providing a material, a step of providing decorative ink on the first surface of the base material, and a step of bonding the first surface of the base material and the polyurethane surface protective layer via a bonding layer. A method for producing a graphic film for a plate is provided.

According to still another embodiment of the present disclosure, a step of providing a base plate, a step of providing a graphic film for the license plate to form a graphic film laminated plate on the base plate, and a graphic film laminated plate. Provided is a method of manufacturing a license plate, comprising a step of embossing or debossing and a step of forming a printing layer on the convex or concave portion of the embossed or debossed graphic film laminated plate.

According to the present disclosure, it has chemical resistance, gasoline resistance, and elongation characteristics that can follow press working without heating, which are necessary for use as a license plate, and has an ink layer formed by baking finish or the like. A graphic film for a license plate that may have print compatibility and a license plate with the graphic film can be provided.

The above description should not be deemed to disclose all embodiments of the invention and all advantages relating to the invention.

It is sectional drawing of the graphic film for license plate of one Embodiment of this disclosure. It is sectional drawing of the graphic film for license plate of another embodiment of this disclosure. It is sectional drawing of the retroreflective graphic film for a license plate of one Embodiment of this disclosure. FIG. 5 is a cross-sectional view of a retroreflective graphic film for a license plate according to another embodiment of the present disclosure. A cross-sectional view shows a procedure for manufacturing a license plate according to an embodiment of the present disclosure. A cross-sectional view shows a procedure for manufacturing a license plate according to an embodiment of the present disclosure. A cross-sectional view shows a procedure for manufacturing a license plate according to an embodiment of the present disclosure. A cross-sectional view shows a procedure for manufacturing a license plate according to an embodiment of the present disclosure. A cross-sectional view shows a procedure for manufacturing a license plate according to an embodiment of the present disclosure. It is a figure which shows the evaluation result of the embossing test of the license plate of one Embodiment of this disclosure.

The graphic film for a license plate according to the first embodiment is a graphic film for a license plate including a polyurethane surface protective layer to which a printing layer is applied, and the polyurethane surface protective layer is at least either a polyester skeleton or a polycarbonate skeleton. It contains a reaction product of a polyol having a polyfunctionality, that is, a bifunctional or higher aliphatic isocyanate, or an aqueous polyurethane. By using these materials, a surface protective layer having good weather resistance can be provided.

The license plate graphic film of the first embodiment includes a polyurethane surface protective layer containing a water-based polyurethane. When water-based polyurethane is used, it can further show better followability to embossing / debossing at room temperature and can provide good print compatibility to a print layer formed by baking coating or the like.

In the graphic film for a license plate of the first embodiment, the polyurethane surface protective layer contains an aqueous polyurethane, and the aqueous polyurethane has at least either a polyester skeleton or a polycarbonate skeleton, and has a temperature of about 80 ° C. or higher and about 180 ° C. It may have the following glass transition temperatures. When water-based polyurethane is used, high adhesion and chemical resistance can be imparted to the print layer formed on the surface protective layer by baking coating or the like, and better print compatibility can be provided.

The license plate graphic film of the first embodiment contains a carboxyl group-containing (meth) acrylic polymer and has a first surface and a second surface facing the first surface, and can accept decorative ink (meth). ) An acrylic polymer layer may be included. By providing a decorative layer on the first surface or the second surface of the (meth) acrylic polymer layer, it is possible to impart decorativeness or design to the graphic film.

In the license plate graphic film of the first embodiment, the (meth) acrylic polymer layer may further contain a nitrogen atom-containing (meth) acrylic polymer.

The license plate graphic film of the first embodiment may include a bonding layer between the polyurethane surface protective layer and the first surface of the (meth) acrylic polymer layer.

In the graphic film for license plate of the first embodiment, an adhesive layer may be included on the second surface side of the (meth) acrylic polymer layer.

In the license plate graphic film of the first embodiment, the (meth) acrylic polymer layer and / or the (meth) acrylic adhesive layer may contain a white pigment. By including the white pigment, the hiding effect on the underlying color can be enhanced. Thereby, for example, the brightness of the color of the decorative layer can be increased and the quality of the graphic image can be improved.

The license plate graphic film of the first embodiment may include a retroreflective layer. By including the reflexive layer, the visibility of the license plate can be improved.

In the method for producing a graphic film for a license plate in the second embodiment, a printing layer containing a reaction product of a polyol having at least either a polyester skeleton or a polycarbonate skeleton and a polyfunctional aliphatic isocyanate, or an aqueous polyurethane is used. A step of providing an applicable polyurethane surface protective layer, and a carboxyl group-containing (meth) acrylic polymer is contained above or above the polyurethane surface protective layer, and is formed on the first surface and the first surface of the surface protective layer side. A step of providing a decorative ink-acceptable (meth) acrylic polymer layer having a second surface facing each other, a step of providing a decorative ink on the second surface of the (meth) acrylic polymer layer, and (meta). ) A step of providing an adhesive layer on or above the second surface of the acrylic polymer layer.

In the method for producing a graphic film for a license plate in the second embodiment, the (meth) acrylic polymer layer may further contain a nitrogen atom-containing (meth) acrylic polymer.

A method for producing a graphic film for a license plate according to a third embodiment is a printing layer containing a reaction product of a polyol having at least either a polyester skeleton or a polycarbonate skeleton and a polyfunctional aliphatic isocyanate, or an aqueous polyurethane. A decoration having a first surface and a second surface facing the first surface, a step of providing an applicable polyurethane surface protective layer, a step of providing a bonding layer on or above the polyurethane surface protective layer. A step of providing an ink-acceptable base material, a step of providing decorative ink on the first surface of the base material, and a step of bonding the first surface of the base material and the polyurethane surface protective layer via a bonding layer. ,including.

The method for manufacturing the license plate in the fourth embodiment includes a step of providing a base plate, a step of providing the graphic film for the license plate described above on the base plate to form a graphic film laminated plate, and a graphic film laminated plate. May include a step of embossing or debossing, and a step of forming a print layer on the convex or concave portion of the embossed or debossed graphic film laminated plate.

Hereinafter, the present invention will be described in more detail with reference to the drawings for the purpose of exemplifying typical embodiments of the present invention, but the present invention is not limited to these embodiments. Regarding reference numbers in drawings, elements with similar numbers in different drawings indicate that they are similar or corresponding elements.

A cross-sectional view of a graphic film for a license plate according to an embodiment of the present disclosure is shown in FIG. The graphic film 100 for a license plate has a polyurethane surface protective layer 140 to which at least a printing layer on which character information such as a registration number is printed is applied. The surface protective layer 140 is a layer to which a printing layer with ink containing melamine or the like for baking coating used for the character portion of the license plate or the like is applied. The graphic film 100 contains a carboxyl group-containing (meth) acrylic polymer adjacent to the polyurethane surface protective layer 140, and has a first surface on the surface protective layer 140 side and a second surface facing the first surface. It has a (meth) acrylic polymer layer 130 that can accept decorative inks. The second surface of the (meth) acrylic polymer layer 130 has a decorative layer 120 and an adhesive layer 110 that form a decorative image such as a graphic. In the graphic film 100, a liner such as a PET film, a polyethylene film, or a laminated paper peeled with a silicone resin or the like is applied to the polyurethane surface protective layer 140 and / or the adhesive layer 110 for the purpose of surface protection or prevention of adhesion of foreign matter. You may.

The material of the polyurethane surface protective layer 140 is at least a polyester skeleton or polycarbonate from the viewpoints of chemical resistance, gasoline resistance, elongation characteristics that can follow press working without heating, print compatibility with baking ink, and the like. A reaction product of a polyol having any of the skeletons and a polyfunctional aliphatic isocyanate, or an aqueous polyurethane is preferable. These materials can be used as the surface protective layer 140 by coating the liner with, for example, a knife coat, a bar coat, a blade coat, a doctor coat, a roll coat, a cast coat, or the like, or a film by a casting method or the like. It can also be used in the form of.

Curable compositions containing at least a polyol having either a polyester skeleton or a polycarbonate skeleton and a polyfunctional aliphatic isocyanate are at relatively low temperatures, such as about 110 ° C. or lower, about 100 ° C. or lower, or about 80 ° C. or lower. It is possible to provide a reactant having sufficient elongation characteristics, chemical resistance, and gasoline resistance even when cured.

Polyesters having at least either a polyester skeleton or a polycarbonate skeleton may include polyester polyols such as acrylic polyols, polycaprolactone diols and polycaprolactone triols, polycarbonate polyols such as cyclohexanedimethanol carbonate and 1,6-hexanediol carbonate. Yes, but not limited to them. Examples of such polyols include Takelac (registered trademark) UA702 (acrylic polyol, Mitsui Chemicals, Inc.), Placcel (registered trademark) 205H (polycaprolactone diol, Daicel Co., Ltd.), DURANOL (registered trademark) G3450J (polycarbonate diol, etc.). Asahi Kasei Chemicals Co., Ltd.), Desmophen (registered trademark) A565X (polyester polyol, Sumika Bayer Urethane Co., Ltd.), Desmophen (registered trademark) A870BA (polyester polyol, Sumika Bayer Urethane Co., Ltd.) and the like.

In some embodiments, the polyol having at least either a polyester skeleton or a polycarbonate skeleton has a hydroxyl equivalent of about 40% or more, about 60% or more, or about 80% of the total polyol composition contained in the curable composition. As mentioned above, it can be about 100% or less, about 95% or less, or about 90% or less.

Examples of desirable polyfunctional, i.e., bifunctional or higher functional aliphatic isocyanates are hexamethylene diisocyanates (HDI), isophorone diisocyanates (IPDI), 4,4'-methylenebiscyclohexyldiisocyanates (also referred to as hydrogenated MDI, H12MDI, etc.). It includes, but is not limited to, polyisocyanates such as bullets, isocyanurates, and adducts. IPDI isocyanurates and adducts are preferred because they provide a cured product with high weather resistance and chemical resistance. As such aliphatic isocyanates, for example, Desmodur (registered trademark) Z4470BA (polyisocyanate derivative of isocyanurate from IPDI, Sumika Bayer Urethane Co., Ltd.), DURANATE (registered trademark) TPA-100 (isocyanurate of HDI, Asahi Kasei) Chemicals Co., Ltd.) and the like.

In some embodiments, the polyfunctional aliphatic isocyanate has an isocyanate equivalent of about 50% or more, about 60% or more, or about 70% or more, about 100% or less of the total isocyanate composition contained in the curable composition. , About 90% or less, or about 80%.

The curable composition may further comprise a polyol other than the polyol having at least either a polyester skeleton or a polycarbonate skeleton, which is generally widely used in polyurethane compositions, and further comprises a polyisocyanate other than a polyfunctional aliphatic isocyanate. It may be included.

The equivalent ratio of polyisocyanate to polyol is generally about 0.7 equivalent or more, about 0.9 equivalent or more, about 2 equivalent or less, or about 1.2 equivalent or less of polyisocyanate with respect to 1 equivalent of polyol. ..

The curable composition may include a catalyst. As the catalyst, those generally used for forming polyurethane resins, such as di-n-butyltin dilaurate, zinc naphthenate, zinc octene, triethylenediamine and the like can be used. The amount of the catalyst used is generally about 0.005 parts by mass or more, or about 0.01 parts by mass, about 0.5 parts by mass or less, or about 0.2 parts by mass or less with respect to 100 parts by mass of the curable composition. Is.

The curable composition contains ketones such as methyl ethyl ketone, methyl isobutyl ketone and acetyl acetone, aromatic hydrocarbons such as toluene and xylene, alcohols such as ethanol and isopropyl alcohol, and ethyl acetate in order to improve workability and coatability. , Esters such as butyl acetate, and organic solvents such as ethers such as tetrahydrofuran, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate and dipropylene glycol monomethyl ether acetate may be further contained. The amount of the organic solvent used is generally about 1 part by mass or more, about 5 parts by mass or more, about 90 parts by mass or less, or about 80 parts by mass or less with respect to 100 parts by mass of the curable composition.

The glass transition temperature Tg of the polyurethane surface protective layer containing the reactant of the curable composition may be about 50 ° C. or higher. The Tg in the present disclosure is the loss tangent tan δ (loss elastic modulus E) when the viscoelasticity is measured in the temperature range of -40 to 200 ° C. at a tension mode, a frequency of 10.0 Hz, and a heating rate of 5.0 ° C./min. It is the peak temperature of "/ storage elastic modulus E'). When the Tg of the surface protective layer is about 50 ° C. or higher, it is necessary to protect an optional retroreflective layer or the like located below the layer. Sufficient strength, weather resistance and chemical resistance can be provided.

The loss tangent tan δ at 120 ° C. of the polyurethane surface protective layer containing the reactants of the curable composition is about 0.1 or less, and in some embodiments about 0.05 or less, about 0.02 or less, or about. It is 0.01 or less. The loss tangent tan δ in the present disclosure is a value obtained by viscoelasticity measurement at Shear Mode and a frequency of 0.01 Hz.

On the other hand, the aqueous polyurethane is composed of a reaction product of a polycarbonate-based and / or polyester-based polyol compound and an organic polyisocyanate compound, has at least either a polyester skeleton or a polycarbonate skeleton, and has a temperature of about 80 ° C. or higher and about 90. Those having a glass transition temperature of about ° C. or higher, or about 100 ° C. or higher, about 180 ° C. or lower, about 170 ° C. or lower, or about 160 ° C. or lower can be used. Good chemical resistance can be obtained by using a glass having a glass transition temperature of about 80 ° C. or higher.

Examples of the polycarbonate-based polyol compound include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, tetraethylene glycol, dipropylene glycol, 3-methyl-1,5-pentanediol, and cyclohexane. A polyol obtained by an ester exchange method of a saturated aliphatic diol such as dimethanol or a mixture thereof with a substituted carbonate such as diethyl carbonate or diphenyl carbonate, a polyol obtained by the reaction of the saturated aliphatic diol with phosgen, or the like is used. be able to.

Polyester-based polyol compounds include low-molecular-weight polyols, polyvalent carboxylic acids in an amount smaller than their chemical quantitative amount, or ester-forming derivatives such as esters, anhydrides, and halides, and / or lactones, or lactones thereof. Examples thereof include those obtained by a direct esterification reaction and / or an ester exchange reaction with a hydroxycarboxylic acid obtained by hydrolysis ring opening.

Examples of low molecular weight polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, and 2-butyl-2-ethyl-1,3-propane. Diol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2 -Methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptandiol, 1,8-octanediol , 2-Methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, aliphatic diols such as ethylene oxide and / or propylene oxide adduct of bisphenol A, cyclohexanedimethanol, cyclohexanediol Isoalicytic diol, trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, polyglycerin, pentaerythritol, dipentaerythritol, tetramethylolpropane and other trivalent or higher polyols, dimethylolpropionic acid, dimethylolpropionic acid, di Examples thereof include polyols containing a carboxyl group such as methylolbutanoic acid, dimethylolbutyric acid and dimethylol valeric acid, and polyols containing a sulfonic acid group such as 1,4-butanediol-2-sulfonic acid.

Examples of the polyvalent carboxylic acid or its ester-forming derivative include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimeric acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, and 2-methylsuccinic acid. , 2-Methyladipic acid, 3-Methyladipic acid, 3-Methylpentanedioic acid, 2-methyloctanedioic acid, 3,8-dimethyldecanedioic acid, 3,7-dimethyldecanedioic acid, hydrogenated dimeric acid, 3 of aliphatic dicarboxylic acids such as dimer acid, aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, trimellitic acid, trimesic acid and castor oil fatty acid Examples thereof include tricarboxylic acids such as metric acids and polyvalent carboxylic acids such as tetracarboxylic acids such as pyromellitic acid. Examples of the ester-forming derivative of these polyvalent carboxylic acids include these acid anhydrides, halides such as chloride and bromide of the polyvalent carboxylic acid, and methyl ester, ethyl ester, propyl ester and isopropyl ester of the polyvalent carboxylic acid. , Butyl ester, isobutyl ester, amyl ester and other lower aliphatic esters. As the lactones, lactones such as γ-caprolactone, δ-caprolactone, ε-caprolactone, dimethyl-ε-caprolactone, δ-valerolactone, γ-valerolactone, and γ-butyrolactone can be used.

As the aqueous polyurethane, a polyol other than the polycarbonate-based and / or polyester-based polyol compound can be used as long as the polyol compound component does not exceed 50 mol%. Examples of other polyol components that can be used include the above-mentioned low molecular weight polyols and polyether polyols.

Examples of polyether polyols include ethylene oxide adducts such as diethylene glycol and triethylene glycol, propylene oxide adducts such as dipropylene glycol and tripropylene glycol, and ethylene oxide and / or propylene oxide adducts of the above low molecular weight polyols. , Polytetramethylene glycol and the like.

Examples of the organic polyisocyanate compound include tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, p-phenylenediocyanate, xylylene diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyldiphenyl-4, Aromatic diisocyanates such as 4'-diisocyanate, dianisidine diisocyanate, tetramethylxylylene diisocyanate; isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, trans and / or cis-1,4-cyclohexanediisocyanate, norbornene diisocyanate, etc. Alicyclic diisocyanates; 1,6-hexamethylene diisocyanates, 2,2,4 and / or (2,4,4) -trimethylhexamethylene diisocyanates, aliphatic diisocyanates such as lysine diisocyanates; triphenylmethanetri Isocyanate, 1-methylbenzol-2,4,6-triisocyanate, dimethyltriphenylmethanetetraisocyanate triphenylmethanetriisocyanate, 1-methylbenzol-2,4,6-triisocyanate, dimethyltriphenylmethanetetraisocyanate and these Can be mentioned. These may be used in the form of modified products such as carbodiimide modification, nurate modification, biuret modification, etc., or may be used in the form of blocked isocyanate blocked by various blocking agents.

The aqueous polyurethane can contain a chain extender component, and the component includes, for example, a low molecular weight diamine such as ethylenediamine or propylenediamine in which the alcoholic hydroxyl group of the above-exemplified low molecular weight diol is replaced with an amino group. , Polyoxypropylene diamine, polyetherdiamines such as polyoxyethylenediamine, mensendiamine, isophoronediamine, norbornenediamine, bis (4-amino-3-methyldicyclohexyl) methane, diaminodicyclohexylmethane, bis (aminomethyl) cyclohexane , 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro (5,5) alicyclic diamines such as undecane, m-xylene diamine, α- (m / p amino) Phenyl) ethylamine, m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldimethyldiphenylmethane, diaminodiethyldiphenylmethane, dimethylthiotoluenediamine, diethyltoluenediamine, α, α'-bis (4-aminophenyl) -p-diisopropyl Polyamines such as aromatic diamines such as benzene; dicarboxylic acid dihydrazide; 2- (2-aminoethylamino) ethanol and the like can be mentioned.

The aqueous polyurethane is a polyol containing a carboxyl group such as dimethylol propionic acid, dimethylol butanoic acid, dimethylol butyric acid, and dimethylol valeric acid as a part of the above-mentioned polyol compound component, 1,4-butanediol-2- Anionic groups are introduced using polyols containing sulfonic acid groups such as sulfonic acid, to which, for example, trialkylamines such as trimethylamine and triethylamine, N, N-dialkylalkanolamines and N-alkyl. Method of using tertiary amines such as -N, N-dialkanolamines and trialkanolamines, and anionic group neutralizers such as basic compounds such as ammonia, sodium hydroxide, potassium hydroxide and lithium hydroxide in combination. It is possible to use the one hydrated by.

The amount of the polyol compound containing a carboxyl group or a sulfonic acid group is arbitrary, but in consideration of making the water-based polyurethane water-based or adhesiveness to an ink containing melamine for baking coating, etc., about It is used in the range of 1 mol% or more, about 2 mol% or more, or about 5 mol% or more, about 50 mol% or less, about 40 mol% or less, or about 30 mol% or less.

The method for producing the water-based polyurethane is not particularly limited, and a well-known general method can be applied. As a specific production method, a prepolymer method or the like is used in which a prepolymer is synthesized by reacting in a solvent that is inert to the reaction and has a high affinity for water, and then this is fed to water and dispersed. be able to.

As the solvent which is inert to the above reaction and has a high affinity with water, for example, acetone, methyl ethyl ketone, dioxane, tetrahydrofuran, N-methyl-2-pyrrolidone and the like can be used. These solvents are usually about 1% by mass or more, about 2% by mass or more, or about 3% by mass or more, about 100% by mass or less, based on the total amount of the above raw materials used for producing the prepolymer. About 90% by mass or less, or about 80% by mass or less is used. Among these solvents, a solvent having a boiling point of 100 ° C. or lower may be distilled off under reduced pressure after prepolymer synthesis.

In the above production method, the blending ratio of each component can be arbitrary. This compounding ratio can be replaced with the molar ratio of the isocyanate group and the isocyanate-reactive group of each component at the stage of reaction. Regarding this molar ratio, the isocyanate-reactive group is about 0 with respect to the isocyanate group 1. It can be .3 or more, about 0.4 or more or about 0.5 or more, about 1.01 or less, about 1.0 or less, or about 0.99 or less.

In the water-based polyurethane, the amount of the solid content can be any amount, but in general, the amount of the solid content is about 1% by mass or more, about 3% by mass or more, or about 5% by mass or more. , About 80% by mass or less, about 70% by mass or less, or about 60% by mass or less.

In the water-based polyurethane, since the polyurethane molecule is given a crosslinked structure, a commonly used crosslinking agent may be used, if necessary, under conditions that do not adversely affect safety, pot life, or the like. As the cross-linking agent, an aqueous epoxy resin, an epoxy resin emulsion, an aqueous polycarbodiimide, an aqueous polyoxazoline, an aqueous isocyanate and the like can be used.

As the water-based polyurethane, a well-known general emulsifier used for the water-based polyurethane may be used, if necessary. As the emulsifier, an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, a polymer surfactant, a reactive surfactant and the like can be used.

The polyurethane surface protective layer may contain, as other optional components, conventionally used additives such as an ultraviolet absorber, a light stabilizer, a heat stabilizer, a dispersant, a plasticizer, a flow improver, and a leveling agent. Among them, since the license plate is generally used outdoors, it is desirable that the polyurethane surface protective layer contains at least one of an ultraviolet absorber, a light stabilizer and a heat stabilizer. The amount of these additives used can be such that the functions of the surface protective layer and the optionally existing retroreflective layer are not excessively impaired, and for each component, based on the mass of the surface protective layer, Generally, about 0.1% by mass or more, or about 1% by mass or more, about 5% by mass or less, or about 3% by mass or less, and the total of the components is generally about 1% by mass or more, or about 3% by mass or more. , About 10% by mass or less, or about 5% by mass or less.

Specific examples of the ultraviolet absorber and the light stabilizer include Tinuvin (registered trademark) PS, Tinuvin (registered trademark) 99-2, Tinuvin (registered trademark) 326, Tinuvin (trademark) 328, Tinuvin (registered trademark) 384-2 ( Benzotriazole-based UV absorber, BASF), Tinuvin® 400, Tinuvin® 405, Tinuvin® 460 (Hydroxyphenyltriazine-based UV absorber, BASF), Uvinul® 3035, Uvinul (Registered Trademark) 3039 (Cyanoacrylate-based UV absorber, BASF), Tinuvin (registered trademark) 123, Tinuvin (registered trademark) 144, Tinuvin (registered trademark) 152, Tinuvin (registered trademark) 292 (Hinderedamine-based light stabilizer,) BASF), Cyasorb® UV3529 (Hinderdamine Light Stabilizer, Cytec), and Sabostab® UV64 (Hinderdamine Light Stabilizer, SABO). These ultraviolet absorbers and light stabilizers can be used alone or in admixture of two or more.

Specific examples of heat stabilizers include SC-12, SC-308E, SC-320 (Ca / Zn-based heat stabilizer, ADEKA), AC-290, AC-294, AC-296, AC-299 (Ba / Zn). ADEKA), a system heat stabilizer. These heat stabilizers can be used alone or in admixture of two or more.

The thickness of the polyurethane surface protective layer may vary, and is preferably about 5 μm or more, more preferably about 10 μm or more. With this thickness, chemical resistance can be obtained. Further, the thickness may be about 20 μm or more, or about 30 μm or more. On the other hand, the thickness is about 100 μm or less, preferably about 60 μm or less. By setting the thickness to this or less, good followability can be obtained during press working. The thickness may be about 50 μm or less.

The graphic film 100 contains a carboxyl group-containing (meth) acrylic polymer adjacent to the polyurethane surface protective layer 140, and has a first surface on the surface protective layer 140 side and a second surface facing the first surface. Includes a (meth) acrylic polymer layer 130 that can accept decorative inks.

The (meth) acrylic polymer layer 130 includes a carboxyl group-containing (meth) acrylic polymer and optionally a nitrogen atom-containing (meth) acrylic polymer. As used herein, the term "(meth) acrylic" means acrylic or methacrylic. The carboquil group-containing (meth) acrylic polymer is obtained by copolymerizing a monoethylenically unsaturated monomer and an unsaturated monomer containing a carboxyl group. The nitrogen atom-containing (meth) acrylic polymer can be obtained by copolymerizing a monoethylenically unsaturated monomer and an unsaturated monomer containing a nitrogen atom.

This copolymerization can be carried out by radical polymerization. In this case, known polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization and bulk polymerization can be used. Initiators include organic peroxides such as benzoyl peroxide, lauroyl peroxide, and bis (4-terriarybutylcyclohexyl) peroxydicarbonate, and 2,2'-azobisisobutyronitrile, 2,2'. -Azobis-2-methylbutyronitrile, 4,4'-azobis-4-cyanovaleric acid, 2,2'-azobis (2-methylpropionic acid) dimethyl, azobis 2,4-dimethylvaleronitril (AVN), etc. The azo-based polymerization initiator of the above is used. This initiator can be used in an amount of about 0.01 part by mass or more and about 5 parts by mass or less per 100 parts by mass of the monomer mixture.

A (meth) acrylic polymer having a high Tg exerts a high tensile strength of the graphic film, and a (meth) acrylic polymer having a low Tg improves the elongation property of the graphic film at a low temperature. Therefore, in the (meth) acrylic polymer layer, when the Tg of the carboxyl group-containing (meth) acrylic polymer is high, specifically, when the temperature is 0 ° C. or higher, the Tg of the nitrogen atom-containing (meth) acrylic polymer is high. When it is lower than that, specifically less than 0 ° C., and the former Tg is low, specifically less than 0 ° C., the latter Tg is preferably high, specifically 0 ° C. or higher. ..

The weight average molecular weight of the (meth) acrylic polymer is about 10,000 or more, about 50,000 or more, or about 100,000 or more. The weight average molecular weight means the styrene-equivalent molecular weight by the GPC method.

The monoethylene unsaturated monomer constituting the (meth) acrylic polymer is the main component of the polymer, and generally has the formula CH ₂ = CR ₁ COOR ₂ (in the formula, R ₁ is a hydrogen or methyl group. R ₂ is a linear or branched alkyl group, phenyl group, alkoxyalkyl group, phenoxyalkyl group), as well as aromatic vinyl monomers such as styrene, α-methylstyrene, and vinyltoluene. , Vinyl esters such as vinyl acetate are also included. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. , Isooctyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, phenoxyalkyl (meth) acrylate such as phenoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate and 2-methoxy There are alkoxyalkyl (meth) acrylates such as butyl (meth) acrylate, and one or more are used depending on the purpose in order to obtain a desired glass transition temperature, tensile strength, and elongation characteristics.

For example, by copolymerizing a (meth) acrylic monomer having a Tg of 0 ° C. or higher such as methyl methacrylate (MMA) or n-butyl methacrylate (BMA) as a main component, a (meth) acrylic having a Tg of 0 ° C. or higher is used as a main component. A system polymer can be obtained.

A homopolymer polymerized alone, such as ethyl acrylate (EA), n-butyl acrylate (BA), and 2-ethylhexyl acrylate (2EHA), is copolymerized with a component having a Tg of less than 0 ° C. as a main component to obtain Tg. A (meth) acrylic polymer below 0 ° C. can be obtained.

Here, the glass transition temperature (Tg) of the carboxyl group-containing (meth) acrylic polymer and the nitrogen atom-containing (meth) acrylic polymer is based on the FOX formula, assuming that each polymer is copolymerized from n types of monomers. It can be obtained from (the following formula).
1 / Tg = X1 / (Tg1 + 273.15) + X2 / (Tg2 + 273.15) + ... + Xn / (Tgn + 273.15)
(Tg1: Glass transition point of the homopolymer of component 1 Tg2: Glass transition point of the homopolymer of component 2 X1: Weight fraction of the monomer of component 1 added at the time of polymerization X2: Of the component 2 added at the time of polymerization Monomer weight fraction X1 + X2 + ... + Xn = 1)

Examples of the carboxyl group-containing unsaturated monomer copolymerized with the above monoethylene unsaturated monomer to form a carboxyl group-containing (meth) acrylic polymer include acrylic acid, methacrylic acid, maleic acid, itaconic acid, and ω-. Examples thereof include carboxypolycaprolactone monoacrylate, monohydroxyethyl phthalate (meth) acrylate, β-carboxyethyl acrylate, 2- (meth) acryloyloxyethyl succinic acid, and 2- (meth) acryloyloxyethyl hexahydrophthalic acid.

The carboxyl group-containing (meth) acrylic polymer contains a monoethylene unsaturated monomer as a main component, and specifically contains about 60 parts by mass or more, or about 80 parts by mass or more, about 99.5 parts by mass or less, or about 97 parts by mass. Copolymerize the unsaturated monomer containing a carboxyl group in the range of about 0.5 parts by mass or less, or about 3 parts by mass or more, about 40 parts by mass or less, or about 20 parts by mass or less. Can be obtained.

Examples of the nitrogen atom-containing unsaturated monomer copolymerized with the above monoethylene unsaturated monomer to form a nitrogen atom-containing (meth) acrylic polymer include N, N-dimethylaminoethyl acrylate (DMAEA), N, Dialkylaminoalkyl (meth) acrylates such as N-dimethylaminoethyl methacrylate (DMAEMA), dialkylaminoalkyl (meth) acrylamides such as N, N-dimethylaminopropylacrylamide (DMAPAA), N, N-dimethylaminopropylmethacrylate, Examples thereof include a monomer having a nitrogen atom represented by a vinyl monomer having a nitrogen-containing heterocycle such as N, N-dimethyl (meth) acrylamide and vinyl imidazole.

The nitrogen atom-containing (meth) acrylic polymer contains a monoethylene unsaturated monomer as a main component, and specifically contains about 60 parts by mass or more, or about 70 parts by mass or more, about 99.5 parts by mass or less, or about 97 parts by mass. Copolymerize an unsaturated monomer containing a nitrogen atom in a range of about 0.5 parts by mass or more, or about 3 parts by mass or more, about 40 parts by mass or less, or about 30 parts by mass or less. Can be obtained.

After polymerizing the carboxyl group-containing (meth) acrylic polymer and the nitrogen atom-containing (meth) acrylic polymer separately as described above, the (meth) acrylic polymer layer according to the present invention is subjected to a usual molding method. 130 can be formed. Specifically, for example, the (meth) acrylic polymer layer 130 can be formed by mixing a solution of these polymers, applying the solution on the surface protective layer 140 formed on the liner, and drying and solidifying the solution. .. As this coating device, a normal coater, for example, a bar coater, a knife coater, a roll coater, a die coater, or the like can be used. The solidification operation is the same as the drying operation in the case of a paint containing a volatile solvent and the operation of cooling the molten resin component.

In the formation of the (meth) acrylic polymer layer 130, desired tensile strength and elongation characteristics are obtained by changing the compounding ratio of the carboxyl group-containing (meth) acrylic polymer and the nitrogen atom-containing (meth) acrylic polymer. A graphic film having the above can be obtained. Specifically, among the carboxyl group-containing (meth) acrylic polymer and the nitrogen atom-containing (meth) acrylic polymer, the compounding ratio of the polymer having a high Tg and the polymer having a low Tg is 10:90 to 90:10. It is 20:80 to 90:10, or 30:70 to 90:10.

In the (meth) acrylic polymer layer 130, a network structure is formed by cross-linking the carboxyl group-containing (meth) acrylic polymer and the nitrogen atom-containing (meth) acrylic polymer, and the chemical resistance is improved. As the cross-linking component, a cross-linking agent having a functional group capable of reacting with a carboxyl group can be used. Specifically, a bisamide-based cross-linking agent (for example, 3M RD1054), an aziridine-based cross-linking agent (for example, Nippon Catalyst Chemitite (registered trademark) PZ33, Abyssia-made NeoCryl (registered trademark) CX-100), a carbodiimide-based cross-linking agent (For example, carbodilite V-03, V-05, V-07 manufactured by Nisshinbo), epoxy-based cross-linking agent (for example, E-AX, E-5XM, E5C manufactured by Soken Kagaku), isocyanate-based cross-linking agent (for example, manufactured by Asahi Kasei Chemicals). Duranate (registered trademark) TPA-100) or the like is used. The amount of the cross-linking agent added is about 0.01 part by mass or more and about 5 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing (meth) acrylic polymer.

A hydroxyl group may be introduced into either or both of a carboxyl group-containing (meth) acrylic polymer and a nitrogen atom-containing (meth) acrylic polymer. As a result, a cross-linking point can be formed. The hydroxyl group-containing (meth) acrylic polymer contains a hydroxyl group unsaturated monomer, specifically, about 0.01 part by mass or more, or about 0.1 part by mass or more, about 10 parts by mass or less, or about 5 parts by mass. It can be obtained by copolymerization in the following range.

The thickness of the (meth) acrylic polymer layer may vary, and may generally be about 5 μm or more, or about 10 μm or more, about 100 μm or less, about 60 μm or less, or about 50 μm or less. When the thickness is about 5 μm or more, the acceptability of the decorative ink can be obtained, and when the thickness is about 100 μm or less, the followability during press working can be obtained.

A decorative layer 120 and an adhesive layer 110 may be formed on the second surface of the (meth) acrylic polymer layer 130.

The decorative layer 120 can be used to impart decorativeness or design to the graphic film. When a graphic film is used for a license plate, a pattern, a pattern, or the like may be formed on a background portion other than the characters on the license plate. Examples of the decorative layer include a color layer exhibiting a special color, a metallic color, a pattern such as wood grain and stone grain, and a pattern layer for imparting a logo, a pattern, etc. to a structure. As the material of the color layer or the pattern layer, for example, a material in which an inorganic pigment, an organic pigment, a bright material, or the like is dispersed in a binder resin can be used. In certain embodiments, the decorative layer can be formed by an inkjet printer, screen printing, offset printing, or the like.

The thickness of the decorative layer may vary, and is generally about 1 μm or more, or about 2 μm or more, about 8 μm or less, or about 5 μm or less when a solvent-based ink is used. When the UV curable ink is used, it can be about 1 μm or more, or about 5 μm or more, about 50 μm or less, or about 30 μm or less.

Organic pigments conventionally known as pigments can be used. Specific examples of organic pigments include C.I. I. Pigment White 6, C.I. I. Pigment Black 7, C.I. I. Pigment Red 122, 202, 254, 255, C.I. I. Pigment Orange 43, C.I. I. Pigment Violet 19, 23, C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, C.I. I. Pigment Brown 23, 25, C.I. I. Pigment Yellow 74, 109, 110, 128, C.I. I. Examples thereof include organic pigments such as Pigment Green 7 and 36.

Inorganic pigments conventionally known as pigments can also be used. Specific examples of inorganic pigments include carbon blacks such as furnace black, channel black, thermal black, and acetylene black, black iron oxide, yellow iron oxide, red iron oxide, ultramarine blue, dark blue, cobalt blue, titanium yellow, turquoise, and molybdate orange. , Inorganic pigments such as titanium oxide.

In order to improve the dispersibility of the pigment in the ink composition, a slurry in which the pigment is supported on a resin may be used. As such a slurry, Microlith ™ Yellow 2040K, Red3630K, Magenta 4535K, Blue 7080K, Green 8750K, Black 0066K, White, in which the pigment was carried by a vinyl chloride-vinyl acetate copolymer resin. 0022K (BASF) and the like can be mentioned.

The pigment can be used alone or in combination of two or more. The amount of the pigment used is generally about 1 part by mass or more, or about 2 parts by mass or more, about 30 parts by mass or less, or about 25 parts by mass or less with respect to 100 parts by mass of the ink composition.

Suitable binder resins for use with the pigments described above include, but are not limited to, at least one of vinyl chloride-vinyl acetate copolymers containing vinyl chloride units and vinyl acetate units. The vinyl chloride-vinyl acetate copolymer may contain other polymerization units such as vinyl alcohol units, maleic acid units, hydroxyalkyl acrylic acid ester units and the like. Specific examples of such binder resins include SOLBIN (registered trademark) C, SOLBIN (registered trademark) CL, SOLBIN (registered trademark) CNL (vinyl chloride-vinyl acetate copolymer resin, Nissin Chemical Industry Co., Ltd.), SOLBIN ( Registered trademark) A, SOLBIN (registered trademark) AL (vinyl chloride-vinyl acetate-vinyl alcohol copolymer resin, Nissin Chemical Industry Co., Ltd.), UCAR (registered trademark) Solution Vinyl Resin VYHH (vinyl chloride-vinyl acetate copolymer resin) , Dow Chemical Japan Co., Ltd.), UCAR (registered trademark) Solution Vinyl Resin VAGH (vinyl chloride-vinyl acetate-vinyl alcohol copolymer resin, Dow Chemical Japan Co., Ltd.), UCAR (registered trademark) Solution Vinyl Resin VMCH (chloride) Vinyl-vinyl acetate-maleic acid copolymer resin, Dow Chemical Japan Co., Ltd.), UCAR (registered trademark) Solution Vinyl Resin VMCC (vinyl chloride-vinyl acetate-maleic acid copolymer resin, Dow-Chemical Japan Co., Ltd.), UCAR (Registered Trademark) Solution Vinyl Resin VMCA (vinyl chloride-vinyl acetate-maleic acid copolymer resin, Dow-Chemical Japan Co., Ltd.), UCAR (registered trademark) Solution Vinyl Resin VROH (vinyl chloride-vinyl acetate-hydroxyalkylacrylic acid ester) Examples thereof include copolymer resin, Dow-Chemical Japan Co., Ltd.), VINNOL (registered trademark) E15 / 45 (vinyl chloride-vinyl acetate copolymer resin, Wacker Chemie AG) and the like.

The binder resin can be used alone or in combination of two or more. The amount of the binder resin used is generally about 5 parts by mass or more, or about 10 parts by mass or more, about 50 parts by mass or less, or about 20 parts by mass or less with respect to 100 parts by mass of the ink composition.

In order to improve workability, coatability, etc., the ink composition contains ketones such as methyl ethyl ketone, methyl isobutyl ketone and acetyl acetone, aromatic hydrocarbons such as toluene and xylene, alcohols such as ethanol and isopropyl alcohol, and ethyl acetate. Additional organic solvents such as esters such as butyl acetate and ethers such as tetrahydrofuran, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate and dipropylene glycol monomethyl ether acetate may be further included, but are not limited thereto. The amount of the organic solvent used is generally about 1 part by mass or more, about 5 parts by mass or more, about 90 parts by mass or less, or about 80 parts by mass or less with respect to 100 parts by mass of the ink composition.

The ink composition may contain, as other optional components, conventionally used additives such as an ultraviolet absorber, a light stabilizer, a heat stabilizer, a dispersant, a plasticizer, a flow improver, and a leveling agent.

Since the graphic film is mainly used outdoors as a license plate, it is desirable that the ink composition contains at least one of an ultraviolet absorber, a light stabilizer and a heat stabilizer. The amount of these additives used generally depends on the intended use. Typically, the amount used is generally about 0.1% by weight or more, or about 0.2% by weight or more, about 5% by weight or less, or about 5% by mass or less for each component, based on the mass of the ink composition. About 3% by mass or less, the total of the components can be generally about 0.1% by mass or more, or about 0.2% by mass or more, about 5% by mass or less, or about 3% by mass or less.

Specific examples of the ultraviolet absorber and the light stabilizer include Tinuvin (registered trademark) PS, Tinuvin (registered trademark) 99-2, Tinuvin (registered trademark) 326, Tinuvin (registered trademark) 328, and Tinuvin (registered trademark) 384-2. (Benzotriazole UV absorber, BASF), Tinuvin® 400, Tinuvin® 405, Tinuvin® 460 (Hydroxyphenyltriazine UV absorber, BASF), Uvinul® 3035, Uvinul® 3039 (Cyanoacrylate-based UV absorber, BASF), Tinuvin® 123, Tinuvin® 144, Tinuvin® 152, Tinuvin® 292 (Hinderedamine-based light stabilizer) , BASF), Cyberb® UV3529 (Hinderdamine Light Stabilizer, Cytec), and Sabostab® UV64 (Hinderdamine Light Stabilizer, SABO). These ultraviolet absorbers and light stabilizers can be used alone or in admixture of two or more.

Specific examples of heat stabilizers include SC-12, SC-308E, SC-320 (Ca / Zn-based heat stabilizer, ADEKA), AC-290, AC-294, AC-296, AC-299 (Ba / Zn). ADEKA), a system heat stabilizer. These heat stabilizers can be used alone or in admixture of two or more.

Adhesives that can be used on the adhesive layer 110 are based on, but not limited to, (meth) acrylic pressure sensitive adhesives, natural rubbers, synthetic rubbers, polyesters, polyethers, silicones or other polymers and are required. Other pressure-sensitive adhesives may be used, including additives such as tackifiers, antioxidants, UV absorbers, plasticizers, etc. As used herein, the term "pressure sensitive adhesive" refers to an adhesive that is permanently adhesive at room temperature, adheres to various surfaces with light pressure, and does not exhibit a phase change (from liquid to solid). The adhesive may be thermally crosslinked by a crosslinking agent or crosslinked by radiation (for example, an electron beam or ultraviolet rays).

A white pigment can be blended in the adhesive layer 110. As a white pigment, titanium oxide in particular has an excellent ability to conceal the color of the base plate (base) to which the graphic film is applied. Both the rutile type and the anatase type can be used as titanium oxide, and examples of commercially available products are Typake (registered trademark) R-820, R-830, R-930, A-100, and A-. 220 (Ishihara Sangyo Co., Ltd.), Typure (registered trademark) R-105, R-960 (DuPont Co., Ltd.) and the like can be mentioned.

The base material side of the laminate in which the adhesive layer 110 is laminated on the base material may be applied directly to the (meth) acrylic polymer layer 130 or via the bonding layer described below. In this case, the white pigment can be blended in the adhesive layer and / or the base material.

The material of the base material is not particularly limited, and for example, polyolefins such as polyethylene and polypropylene, polyesters such as PET, polycarbonate, polyvinyl chloride, polyvinylidene chloride, polystyrene, (meth) acrylic, and polyamide can be used. ..

The thickness of the base material may vary, and is generally about 5 μm or more, preferably about 10 μm or more. If it is thicker than this thickness, the handleability is good. The thickness can be about 500 μm or less, preferably about 300 μm or less. If the thickness is less than this thickness, followability during press working can be obtained.

As the base material, the retroreflective layer described below can also be used.

When a transparent adhesive layer is formed without blending a white pigment in the adhesive layer 110, a retroreflective layer and an adhesive layer described below are further applied to the adhesive layer 110 to provide a graphic having retroreflective properties. It can also be a film.

The thickness of the adhesive layer may vary and may generally be about 5 μm or more, or preferably about 10 μm or more, about 150 μm or less, or about 50 μm or less.

FIG. 2 shows a cross-sectional view of a graphic film for a license plate according to another embodiment of the present disclosure. The license plate graphic film 200 of FIG. 2 has a polyurethane surface protective layer 240, a bonding layer 230, a decorative layer 220, a base material layer 215 capable of receiving decorative ink, and an adhesive layer 210. Here, the polyurethane surface protective layer 240, the decorative layer 220, and the adhesive layer 210 are as described above in the embodiment shown in FIG.

The bonding layer 230 is a layer for bonding each layer of the graphic film, and may be arranged between the layers as needed. The bonding layer can be formed from a conventionally known adhesive, and is appropriately selected depending on the material of the object to be bonded. As the adhesive, for example, an adhesive based on (meth) acrylic resin, epoxy resin, polyester resin or the like can be used. Further, the same material as the adhesive layer 110 can be used. When a decorative layer, a retroreflective layer, or the like is included below the bonding layer, it is preferable that the bonding layer is transparent to visible light so as not to affect the visibility.

The thickness of the bonding layer is not particularly limited, but can be generally about 5 μm or more, preferably about 10 μm or more, about 150 μm or less, or about 50 μm or less.

The base material layer 215 capable of receiving the decorative ink of FIG. 2 has a decorative layer 220 on the first surface, and is bonded to the polyurethane surface protective layer 240 via the bonding layer 230. This embodiment is significant when, for example, an adhesive layer 210 and a base material layer 215 capable of receiving decorative ink are formed on a liner, and then a decorative layer 220 is formed by an inkjet device or the like. Is. In this case, the base material layer 215 that can receive the decorative ink can be formed by applying a solution of the material constituting the base material layer to the adhesive layer 210 on the liner, and drying and solidifying the base layer 210. As this coating device, a normal coater, for example, a bar coater, a knife coater, a roll coater, a die coater, or the like can be used. It is also possible to use the base material layer 215 that can receive the decorative ink in the form of a film by a melt extrusion molding method or the like, and attach it to the adhesive layer 210. As the material of the base material layer that can accept the decorative ink, the same material as the material of the base material, the same material as the (meth) acrylic polymer layer 130, and a mixed material thereof can be used. it can. Further, the base material layer may be a single layer made of these materials or a layer having a laminated structure. In the case of a substrate layer in the form of a film, the substrate layer can also be retroreflective as described below.

The breaking strength of the license plate graphic film is preferably about 5 N / 25 mm or more, about 10 N / 25 mm or more, or about 20 N / 25 mm or more from the viewpoint of good durability, and is preferable from the viewpoint of ease of manufacture. , About 200 N / 25 mm or less, about 175 N / 25 mm or less, or about 150 N / 25 mm or less. In the present disclosure, the breaking strength is a value measured in accordance with JIS Z 0237.

The elongation of the graphic film for the license plate is preferably about 30% or more, or about 35% or more, from the viewpoint of preventing cracks during embossing or debossing and preventing lifting from the adherend, for example, the base plate. Yes, from the viewpoint of good mechanical strength, it is preferably about 400% or less, or about 350% or less. In the present disclosure, elongation is a value measured according to ASTM test method D882-80a.

A cross-sectional view of the retroreflective graphic film for a license plate according to an embodiment of the present disclosure is shown in FIGS. 3 and 4. Here, the polyurethane surface protective layer, the bonding layer, the decorative layer, and the adhesive layer have already been described in the embodiments shown in FIGS. 1 and 2. The retroreflective layer shown in FIGS. 3 and 4 corresponds to the base material or the portion of the base material layer already described in the embodiments shown in FIGS. 1 and 2. The embodiments shown in FIGS. 3 and 4 include a substrate layer capable of receiving the above-mentioned decorative ink, as can be seen from the application of the decorative layers 342 and 442 to the retroreflective layers 310 and 410. This is an embodiment in which a retroreflective layer is adopted.

The retroreflective graphic film 300 in FIG. 3 has a retroreflective layer 310 having a generally flat main surface 316 and a structured surface 314 on the opposite side of the main surface. The structured surface 314 has a plurality of cube corner elements 312. The adhesive layer 330 is arranged adjacent to the retroreflective layer 310. The adhesive layer 330 may include an adhesive 332 and one or more barrier layers 334, and may further have a liner 336 such as a PET film, a polyethylene film, or a laminated paper that has been peeled off with a silicone resin or the like. The barrier layer 334 has sufficient structural integrity to prevent the adhesive 332 from flowing into the low index layer 338 formed between the structured surface 314 and the barrier layer 334. The barrier layer 334 may be in direct contact with the tip of the cube corner element 312, may be separated from the tip of the cube corner element 312, or may be slightly pushed into the tip of the cube corner element 312. ..

The barrier layer 334 provides a physical "barrier" between the adhesive 332 and the cube corner element 312, allowing the formation of the low index layer 338. The presence of the barrier layer 334 allows retroreflection of light rays 350 incident on the portion of the structured surface 314 adjacent to the low index layer 338 and / or the barrier layer 334. The adhesive layer 330, which does not include the barrier layer 334, adheres to the cube corner element 312, thereby efficiently sealing the retroreflective region and forming an optically active region or cell. The adhesive 332 also holds the retroreflective structure 320 composed of the retroreflective layer 310 and the adhesive layer 330 together as a whole, thereby eliminating the need for a separate encapsulating film and encapsulating process. To do.

As shown in FIG. 3, the light beam 350 incident on the cube corner element 312 adjacent to the low refractive index layer 338 is retroreflected. In the present disclosure, the region of the retroreflective graphic film 300 including the low refractive index layer 338 is an optically active region. In contrast, the region of the retroreflective graphic film 300 that does not include the low index layer 338 is an optically inactive region because it does not substantially retroreflect the incident light rays 350 as shown in FIG. ..

The low refractive index layer 338 is made of a material having a refractive index of about 1.30 or less, about 1.25 or less, about 1.2 or less, about 1.15 or less, about 1.10 or less, or about 1.05 or less. Including. For example, as a low refractive index material, air and, for example, US Patent Application No. Examples include low refractive index materials as described in 61 / 324,249 (all of which are incorporated herein by reference).

As the material of the barrier layer 334, any material that prevents the adhesive 332 from coming into contact with the cube corner element 312 or entering the low refractive index layer 338 can be used. Typical materials used in the barrier layer include resins, UV curable polymers, films, inks, dyes, pigments, inorganic materials, particles, and beads. The dimensions and spacing of the barrier layers may vary. In some embodiments, the barrier layer may form patterns such as grids, stripes, dots, letters, etc. on the retroreflective graphic film.

The thickness of the barrier layer may vary and may generally be about 2 μm or more or about 3 μm or more, about 10 μm or less, about 8 μm or less, or about 4 μm or less.

The retroreflective layer 310 includes any suitable cube corner element 312 configured to reflect incident light in a direction returning it to the light source. The cube corner element 312 may have any suitable structure as long as it exhibits a function of retroreflective. For example, the cube corner element may be a complete cube (sometimes referred to as a full cube or a geometry cube), a truncated cube, a cube corner type triangular pyramid, a cube corner type cavity, and the like. For example, a cube corner element includes a three-sided structure having three sides that are substantially orthogonal to each other. When used, the retroreflective graphic film 300 is typically placed with its display surface facing the intended observer and light source. The light incident on the display surface is incident on the retroreflective graphic film 300 and is reflected by each of the three side surfaces of the cube corner element 312 so as to be emitted from the display surface in a direction substantially toward the light source. In some embodiments, the cube corner elements 312 are tilted relative to each other to improve retroreflection properties over a wider range of incident ray angles. Exemplary embodiments of a retroreflective sheet based on cube corners are U.S. Pat. Nos. 5,138,488 (Szczech), 5,387,458 (Pavelka), 5,450,235 (Pavelka). Smith), No. 5,605,761 (Burns), No. 5,614,286 (Bacon), No. 5,691,846 (Benson, Jr.), and No. 7,422,334. It is disclosed in the issue (Smith).

Resins preferably used for the retroreflective layer 310 include polycarbonate, polymethylmethacrylate, polyethylene terephthalate, aliphatic polyurethane, and ethylene copolymers, their ionomers, and materials used for the (meth) acrylic polymer layer described above. Can be mentioned. The cube corner element 312 included in the retroreflective layer 310 can be formed by casting directly onto a resin film, for example, as described in US Pat. No. 5,691,846 (Benson, Jr.). it can. When the retroreflective layer is formed by radiation curing, suitable resins include, for example, a cured product of a radiation curable composition containing polyfunctional acrylate, epoxy acrylate, acrylated urethane and the like. The resin is advantageous in any or more of, for example, thermal stability, environmental stability, transparency, excellent peelability from a tool or mold, and adhesion to other layers, and is transparent. A cured product of polycarbonate and epoxy acrylate is particularly advantageous in terms of thermal stability and the like.

The thickness of the retroreflective layer may vary and may generally be from about 40 μm or more, about 50 μm or more, or about 55 μm or more, about 150 μm or less, about 100 μm or less, or about 60 μm or less. The thickness of the retroreflective layer is the distance between the main surface of the retroreflective layer and the highest apex of the structured surface. The height of the cube corner element may vary and may generally be about 50 μm or more, about 70 μm or more, or about 80 μm or more, about 150 μm or less, about 120 μm or less, or about 100 μm or less. The height of the cube corner element means the length of the region effective for retroreflection of the side surface constituting the cube corner element in the direction perpendicular to the surface of the retroreflective graphic film.

In another aspect, the present disclosure relates to a method of manufacturing a retroreflective structure 320 having a retroreflective layer 310 and an adhesive layer 330 composed of a barrier layer 334 and an adhesive 332. The adhesive layer 330 includes at least one barrier layer 334 and an adhesive 332. This manufacturing method includes a step of arranging the barrier layer 334 on the adhesive 332 and then a step of laminating the obtained adhesive layer 330 on the retroreflective layer 310. The adhesive layer 330 can be formed by various methods including, but not limited to, the following typical methods. In one typical embodiment, the material forming the barrier layer is printed on the adhesive. The printing method may be a non-contact method, for example, printing using an inkjet printer, or a contact printing method, for example, flexographic printing. In another typical embodiment, the material forming the barrier layer is printed on a flat peel surface, for example using an inkjet or screen printing method, and then transferred from the flat peel surface onto the adhesive. In another typical embodiment, the material forming the barrier layer is flood coated on a liner having a microstructured surface, on which an adhesive is laminated so that the barrier layer has a microstructured surface. Transferred from the liner to the adhesive.

The retroreflective graphic film may further contain an infrared absorber. In this case, the infrared absorber is included in any layer on the path of light incident on and reflected by the retroreflective graphic film. For example, retroreflective layers (eg, retroreflective elements, body layers, seal films, adhesive layers, etc.), polyurethane surface protective layers, (meth) acrylic polymer layers, decorative layers, bonding layers, etc. The adhesive layer may contain an infrared absorber. Further, an infrared absorbing layer (not shown) containing an infrared absorbing agent and a binder resin may be arranged between the polyurethane surface protective layer and the retroreflective layer. In one embodiment, the infrared absorber is included in the retroreflective layer. The average transmittance of the layer containing the infrared absorber for light having a wavelength of 800 to 1000 nm is preferably about 80% or less, about 70% or less, or about 60% or less. The average transmittance of the layer containing the infrared absorber for light having a wavelength of 800 to 1000 nm may be about 0.5% or more, about 1% or more, or about 5% or more.

When infrared rays are incident on a retroreflective graphic film containing an infrared absorber at an arbitrary angle of incidence, the infrared rays are absorbed by a layer containing the infrared absorbers, and the retroreflection of the infrared rays is suppressed. Such retroreflective graphic films are particularly useful for license plates that are required to have visibility with the ALPR infrared system.

As the infrared absorber, a material that absorbs near-infrared radiation (for example, a wavelength of about 760 nm to about 1500 nm) can be used. For example, infrared rays such as cyanine compounds, phthalocyanine compounds, dithiol metal complexes, naphthoquinone compounds, diimonium compounds, and azo compounds. Absorbent dyes and cesium tungsten oxide (CWO), antimony-doped tin oxide (ATO), tin-doped indium oxide (ITO), titanium oxide, zirconium oxide, tantalum oxide, niobium oxide, zinc oxide, indium oxide, tin oxide, cesium oxide. , Infrared absorbing pigments such as zinc sulfide. It is advantageous that the infrared absorber contains a cesium tungsten oxide because of its particularly excellent weather resistance. Although the cesium tungsten oxide exhibits a deep blue color, it is also advantageous in that the required infrared absorption can be maintained without affecting the background color (base color) by appropriately adjusting the concentration.

As the cesium tungsten oxide, those having the general formula CsxWyOz (in the formula, 0.001 ≦ x / y ≦ 1, 2.2 ≦ z / y ≦ 3.0) can be preferably used. More preferably, 0.1 ≦ x / y <1, 2.45 ≦ z / y ≦ 3.0, and particularly preferably x / y = 0.33 and z / y = 3.

The average particle size of the cesium tungsten oxide is preferably about 300 nm or less, or about 100 nm or less, or about 50 nm or less from the viewpoints of dispersibility, visibility of the background color (base color) in the visible light region, and the like. The average particle size of the cesium tungsten oxide may be about 10 nm or more, or about 20 nm or more.

The inclusion of an infrared absorber in the retroreflective graphic film may reduce the whiteness of the retroreflective graphic film. This is because many commonly used infrared absorbers show some absorption in the visible light region. Therefore, in order to enhance the whiteness of the retroreflective graphic film, a whiteness improving material such as titanium oxide, zinc oxide, or an optical brightener is optionally included in the retroreflective graphic film or retroreflective. It may be applied between layers of the graphic film. The use of whiteness-enhancing materials makes the retroreflective graphic film appear white in sunlight.

Whiteness-enhancing materials can be included in retroreflective graphic films in various patterns, areas, arrangements, and tones. In some embodiments, the whiteness-enhancing material coats at least a portion of the retroreflective graphic film. Some whiteness-enhancing materials may reduce the retroreflective performance of retroreflective graphic films. In that case, by controlling the application area of the whiteness-enhancing material, the size and density of individual elements constituting the application pattern of the whiteness-improving material, etc., the retroreflective property having a desired level of retroreflection characteristics and whiteness is obtained. You can get a graphic film.

The retroreflective graphic film 400 in FIG. 4 has a retroreflective layer 410 including a structured surface 414 and a reflective layer 435 adjacent to the structured surface 414. A reflective layer 435 is used in place of the low refractive index layer 338 of FIG. The reflective layer 435 may be, for example, an aluminum coating on the structured surface 414. An adhesive layer 430 containing an adhesive 432 may be provided on the retroreflective graphic film 400 adjacent to the reflective layer 435, and the adhesive layer 430 may further have a liner 436 on the opposite side of the retroreflective layer 410. .. The structured surface 414 includes a plurality of cube corner elements 412.

As shown in FIG. 4, the light beam 450 incident on the cube corner element 412 is retroreflected by the combination of the reflection layer 435 and the cube corner element 412. The region of the retroreflective graphic film 400 in which the reflective layer 435 is adjacent to the cube corner element 412 is an optically active region.

It is desirable that the reflective layer 435 has good adhesiveness to the cube corner element 412. As the reflective layer 435, for example, a metal film formed by vapor deposition can be used. Aluminum, silver, or the like can be used as the vapor-deposited metal. The adhesive strength between the surface of the cube corner element 412 and the vapor-deposited metal film may be improved by a primer treatment such as titanium sputtering. It is known that the irradiation angle of the cube corner element 412 increases when a metal film is used. Instead of the metal film, the reflective layer 435 may include, for example, the multilayer reflective coating described in US Pat. No. 6,243,201 (Fleming), the entire description of which is incorporated herein by reference. The thickness of the reflective layer 435 can generally be about 30 nanometers or more and about 80 nanometers or less.

Sealing films can also be applied to the back of the cube corner elements, which are described, for example, in U.S. Pat. Nos. 4,025,159 (McGrath) and 5,117,304 (Hang). All the descriptions of are also incorporated here. The sealing film retains an air boundary on the back of the cube that allows total internal reflection at the boundary and blocks the entry of contaminants such as dirt and / or moisture.

Regarding the retroreflective characteristics of the retroreflective graphic film, the retroreflective coefficient (according to JIS Z 9117) at an observation angle of 0.2 degrees and an incident angle of 5 degrees is at least about 1 cd / lx / m ² . In some preferred embodiments, the retroreflective sheet has a retroreflection coefficient of about 45 cd / lp / m ² or greater, or about 50 cd / lp / m ² or greater. For example, ISO7591: For white defined in 1982, about 45cd / lx / ^{m 2} or more, it is preferable for the yellow is about 30cd / lx / ^{m 2} or more. In the case of JIS Z 9117 enclosed lens type 1-B-b, white is about 35 cd / lx / m ² or more, yellow is about 25 cd / lx / m ² or more, and red is about 10 cd / lx / m. ² or more, for the yellow red about 13cd / lx / ^{m 2} or more, about 5cd / lx / ^{m 2} or more for the green, it is desirable for the blue is about 3cd / lx / ^{m 2} or more.

An exemplary method for producing a graphic film for a license plate according to an embodiment of the present disclosure comprises a reaction product of a polyol having at least either a polyester skeleton or a polycarbonate skeleton and a polyfunctional aliphatic isocyanate, or an aqueous polyurethane. A step of providing a polyurethane surface protective layer to which a printing layer is applied, and a first surface and a first surface on the surface protective layer side containing a carboxyl group-containing (meth) acrylic polymer on or above the polyurethane surface protective layer. A step of providing a (meth) acrylic polymer layer capable of receiving decorative ink having a second surface facing one surface, and a step of providing decorative ink on the second surface of the (meth) acrylic polymer layer. And a step of providing an adhesive layer on or above the second surface of the (meth) acrylic polymer layer.

The method for manufacturing the graphic film for the license plate will be exemplified with reference to FIGS. 1 and 2, but the method for manufacturing the graphic film is not limited to this.

As a method for producing the graphic film of FIG. 1, for example, a polyurethane material is applied onto a liner and dried to form a polyurethane surface protective layer 140. Next, a (meth) acrylic polymer material is applied onto the polyurethane surface protective layer 140 and dried to form a (meth) acrylic polymer layer 130 capable of receiving decorative ink, and an inkjet is formed on the polymer layer 130. The decorative layer 120 is printed with a printing machine to obtain a laminate 1. An adhesive is applied on a separate liner and dried to form an adhesive layer 110 to obtain a laminate 2. By laminating the decorative layer 120 side of the laminated body 1 and the adhesive layer 110 side of the laminated body 2, the graphic film having the configuration shown in FIG. 1 can be obtained.

As a method for producing the graphic film of FIG. 2, for example, a (meth) acrylic polymer material is applied onto a liner and dried to form a base material layer 215 made of a (meth) acrylic polymer that can accept decorative ink. Then, an adhesive is applied onto another liner and dried to form an adhesive layer 210, and the base material layer 215 and the adhesive layer 210 are bonded together. The liner on the base material layer 215 side is peeled off, and the decorative layer 220 is printed on the base material layer 215 with an inkjet printing machine to obtain a laminate A. A polyurethane material is applied and dried on a separate liner to form a polyurethane surface protective layer 240, and then a bonding agent is applied and dried on the protective layer 240 to form a bonding layer 230, and the laminate B is formed. To get. By laminating the decorative layer 220 side of the laminated body A and the bonding layer 230 side of the laminated body B, the graphic film having the configuration of FIG. 2 can be obtained.

In one embodiment of the disclosure, a license plate containing the graphic film is provided.

The base plate of the license plate is generally a metal plate or a resin plate. Examples of the metal plate include an aluminum plate, a stainless steel plate, and an iron plate. Examples of the resin plate include a polycarbonate plate, a polyester plate, and a vinyl chloride plate. If necessary, these plate materials may be molded into a shape such as a frame.

License plates generally include numbers, letters, graphics, patterns or combinations thereof. In certain embodiments, the appearance of the license plate is regulated by the government and / or jurisdiction. In another embodiment, the display can be formed by a print layer. In still another embodiment, for example, in a license plate, the display portion may be formed by combining an embossed portion (convex portion) or a debossed portion (concave portion) and a printing layer. The depths of the embossed portion and the debossed portion are generally about 1 mm or more and about 2 mm or less, respectively, but are not limited to this range.

In the printing layer, an ink composition containing the above pigment and a binder such as a melamine resin, an alkyd resin, a urethane resin, and a mixed resin thereof is generally applied on a polyurethane surface protective layer or the like by roll coating or the like. It can be formed by baking at a predetermined temperature and time. Specifically, as the ink composition, use NSP-UP 401K-1 Green (manufactured by Nikko Bics Co., Ltd.), MEG screen ink (manufactured by Teikoku Inks Manufacturing Co., Ltd.), which is a one-component heat-curable ink, and the like. Can be done.

The method for manufacturing a license plate according to an embodiment of the present disclosure includes a step of providing a base plate, a step of providing a graphic film for a license plate described above on the base plate to form a graphic film laminated plate, and a graphic film lamination. It includes a step of embossing or debossing the plate and a step of forming a print layer on the convex or concave portion of the embossed or debossed graphic film laminated plate.

The license plate manufacturing method will be exemplified with reference to FIGS. 5A to 5E, but the license plate manufacturing method is not limited to this.

In the graphic film shown in FIG. 5A, an adhesive layer 520, a decorative layer 542, a (meth) acrylic polymer layer 545 that can receive decorative ink, and a polyurethane surface protective layer 544 are laminated on a liner 536 to decorate the liner. The layer 542 is printed on the second surface of the (meth) acrylic polymer layer 545.

As shown in FIG. 5B, the graphic film laminated plate is formed by removing the liner 536 and adhering and laminating the adhesive layer 520 to the aluminum plate 560 which is the base plate.

Next, as shown in FIG. 5C, the graphic film laminated plate is blank-pressed to a desired size using a blank press die 570 and cut out.

As shown in FIG. 5D, the cut-out graphic film laminated plate is embossed / debossed at room temperature to form a display portion and a frame portion at the edge of the license plate. In FIG. 5D, the convex portion (embossed portion) is shown as a pedestal of the display portion. The frame portion can impart strength to the license plate to prevent deformation of the license plate.

As shown in FIG. 5E, a print layer 546 is formed on the convex portion (embossed portion) of the embossed graphic film laminated plate by roll coating or the like. In this way, the license plate 500 including the graphic film can be produced.

In the following examples, specific embodiments of the present disclosure will be illustrated, but the present invention is not limited thereto. All parts and percentages are by mass unless otherwise stated.

In this example, the materials used in the polyurethane surface protective layer are shown in Table 1, and the (meth) acrylic polymer solution used in the (meth) acrylic polymer layer and the adhesive layer are shown in Table 2, respectively.

An aqueous polyurethane dispersion and a solvent-based polyurethane solution were prepared using each component shown in Table 1.

<Water-based polyurethane dispersion (water-based PU)>
1.59 parts by mass of Tinuvin® 292, 2.68 parts by mass of Tinuvin® 1130, 0.57 parts by mass of Lipal® 860K, 0.28 parts by mass of 2-amino-2 -Methylpropanol and 10.37 parts by mass of distilled water were mixed. 14.80 parts by mass and 26.90 parts by mass of Carbodirite (registered trademark) V-02 were added to 200.00 parts by mass of Eternacol (registered trademark) UW5002 and mixed to prepare an aqueous polyurethane dispersion. ..

<Solvent-based polyurethane solution (solvent-based PU)>
36.40 parts by mass of Placcel® 205H, 29.00 parts by mass of Takelac® UA702, 1.03 parts by mass of Tinuvin® 292, 1.03 parts by mass of Tinuvin® 99-2, 60.55 parts by mass of Desmodur® Z4470BA was mixed. A solvent-based polyurethane solution was prepared by further mixing 0.024 parts by mass of dibutyltin dilaurate and 3.50 parts by mass of acetylacetone with the mixed solution.

The characteristics of the graphic film and the license plate containing the film were evaluated using the following test method.

<Viscoelastic properties-Measurement of glass transition temperature Tg and tan δ>
A polyurethane solution is applied on a 38 μm-thick peel-treated polyester film (manufactured by Teijin DuPont), dried in an oven at a temperature of 80 ° C. for 10 minutes, and then the polyester film is removed to remove a 50 μm-thick polyurethane surface protective layer. To make.

The obtained surface protective layer was cut into a width of 10 mm and a length of 50 mm to prepare a strip-shaped sample, and a viscoelasticity measuring device RSA-III manufactured by Rheometric Scientific was used under the conditions of a tensile mode and a frequency of 10.0 Hz. The loss tangent (tan δ) (loss elastic modulus E ″ / storage elastic modulus E ′) in the temperature range of 0 to 160 ° C. is measured at a heating rate of 5.0 ° C./min. The obtained peak loss tangent (tan δ) The temperature is defined as the glass transition temperature (Tg).

<Decorative ink printing characteristics>
The decorative layer is printed on the (meth) acrylic polymer layer that can accept the decorative ink of the graphic film using the inkjet printing machine JV-33-130. Visually check the appearance of ink bleeding, repellency, and color sharpness. The one with no change in appearance is referred to as "OK", and the one with confirmed change in appearance is referred to as "NG (Not Good)".

<Embossing>
Emboss the license plate with the graphic film attached at room temperature. Visually check for defects such as breakage and peeling of the graphic film. As illustrated in FIG. 6, the character "ma" is formed by embossing, and the level where defects are conspicuous near the embossed part and cannot be actually used is "x", and the level is actually usable but only a small part. Those with defects are marked with "Δ", and those without defects are marked with "○".

<Adhesiveness>
The adhesiveness of the graphic film on the license plate to which the graphic film is attached is evaluated by a cross-cut test according to JIS K5600. Make cuts with a cutter in a grid pattern with 5 vertical and horizontal lines at 1 mm intervals, and attach Nichiban Cellotape (registered trademark) (manufactured by Nichiban Co., Ltd.) on it and peel it off. "○" indicates that the grid-like film has no peeling, "△" indicates that the film is practically usable but slightly peeled off, and "△" indicates that the film is clearly peeled off and cannot be used. × ”. This test is performed both on a printed layer (Ink) that is roll-coated on the embossed protrusions and on a flat surface (Top) that is not roll-coated.

<Chemical resistance>
The chemical resistance test is carried out by evaluating the polyurethane surface protective layer of the graphic film (Top) and evaluating the printed layer after applying the printed layer by roll coating to the polyurethane surface protective layer on the embossed protrusion (Ink). To do. Since the print layer itself has sufficient chemical resistance, it does not dissolve, but the latter evaluation is to confirm defects such as peeling when chemicals penetrate the interface between the print layer and the graphic film. belongs to.

(1) Chemical resistance test on the surface of graphic film (Top)
A cloth impregnated with lacquer thinner (RA-50, manufactured by Sankyo Chemical Co., Ltd.) is wiped back and forth 30 times against the surface of the graphic film where the print layer is not formed while applying a pressure of 500 g. Visually observe the presence or absence of changes in the appearance of the coating film, and evaluate the following five stages. Graphic films with 3 or more points are acceptable for practical use.
5: No defects 4: Slight marks remain 3: Slight rubbing marks remain, surface becomes slightly rough 2: Surface becomes rough 1: Surface melts and tears

(2) Chemical resistance test (Ink) of roll-coated printed layer
A cloth impregnated with lacquer thinner (RA-50, manufactured by Sankyo Chemical Co., Ltd.) is wiped back and forth 30 times against the surface of the print layer printed on the graphic film while applying a pressure of 500 g. Visually observe the presence or absence of changes in the appearance of the coating film, and evaluate the following five stages. Graphic films with 3 or more points are acceptable for practical use.
5: No defects 4: Slight marks remain 3: Slight scratches remain and the surface becomes slightly rough 2: Slight peeling of the print layer is observed 1: Peeling of the print layer is significantly observed

<Stain resistance>
Draw a line on the polyurethane surface protective layer of the graphic film with a black oil-based marker (Magic Ink (registered trademark), Teranishi Kogyo Co., Ltd.) and leave it at room temperature for 24 hours. Wipe off the ink with a cloth soaked with lacquer thinner (RA-50, Sankyo Chemical Co., Ltd.), visually observe the presence or absence of ink residue and changes in the appearance of the coating film, and perform the following five-step evaluation. Graphic films with 3 or more points are acceptable for practical use.
5: No ink residue 4: Slight ink marks are observed 3: Some ink marks are left 2: Ink residue is clearly observed 1: Ink cannot be removed at all and ink bleeds and spreads

<Gasoline resistance>
Immerse the license plate with the graphic film in gasoline for 4 hours. Visually observe the presence or absence of changes in the appearance of the coating film, and evaluate the following five stages. Graphic films with 3 or more points are acceptable for practical use.
5: No defects 4: Slight traces and peeling are observed 3: Slight peeling is observed from the edge 2: Swelling and deformation of the film are observed 1: Swelling, deformation and peeling of the film are observed

<Example 1>
The material for the (meth) acrylic polymer layer in the blending ratio shown in Table 3 is coated on Lumiror® T-60 (50 μm thick PET carrier film, manufactured by Toray Industries, Inc.) and dried at 100 ° C. for 5 minutes. Then, a laminated film 1 provided with a base material layer made of a (meth) acrylic polymer capable of accepting a decorative ink having a thickness of 30 μm was produced.

The adhesive layer material having the blending ratio shown in Table 3 is coated on Purex® A-55 (38 μm thick peelable PET liner film, manufactured by Teijin DuPont Film Co., Ltd.) and dried at 100 ° C. for 10 minutes. , A laminated film 2 provided with a white adhesive layer having a thickness of 20 μm was produced.

After laminating by laminating so that the base material layer of the laminated film 1 and the adhesive layer of the laminated film 2 overlap, Lumiror (registered trademark) T-60 is removed, and an inkjet printing machine (JV-) is applied to the surface of the base material layer. The decorative layer was printed with 33-130 (manufactured by Mimaki Engineering Co., Ltd.) to prepare a laminated film 3.

The above-mentioned aqueous polyurethane dispersion was coated on Lumiror (registered trademark) T-60 and dried at 100 ° C. for 5 minutes to prepare a polyurethane surface protective layer having a thickness of 30 μm. The material for the bonding layer of the blending ratio shown in Table 3 is coated on the protective layer and dried at 100 ° C. for 5 minutes to form a bonding layer having a thickness of 20 μm, and the polyurethane surface protective layer and the bonding layer are provided. The laminated film 4 was produced.

A graphic film was produced by laminating the base material layer having the decorative layer of the laminated film 3 and the bonding layer of the laminated film 4 by laminating so as to overlap each other.

Lumiror (registered trademark) T-60 on the polyurethane surface protective layer side was removed, and LD-K-1020 (manufactured by Hitachi Kasei Co., Ltd.), a protective film, was laminated. After removing Purex (registered trademark) A-55 on the adhesive layer side, the graphic film is laminated on an aluminum plate (based on A1050P JIS H4000, 1.0 mm x 165.5 mm x 330.5 mm), and the graphic film laminated plate. Was produced. The laminated plate was embossed with an embossing machine at room temperature to form a protrusion of a vehicle number. After removing the protective film, a color ink (NSP-UP 401K-1 Green, manufactured by Nikko Bics Co., Ltd.) was coated only on the protrusions of the vehicle number by a roll coating method to form a print layer. It was dried in an oven at 120 ° C. for 20 minutes to prepare a license plate containing a graphic film.

<Example 2>
The above-mentioned aqueous polyurethane dispersion was coated on Lumiror (registered trademark) T-60 and dried at 100 ° C. for 5 minutes to prepare a polyurethane surface protective layer having a thickness of 30 μm. The protective layer is coated with the material for the (meth) acrylic polymer layer having the blending ratio shown in Table 3, dried at 100 ° C. for 5 minutes, and can accept the decorative ink having a thickness of 20 μm (meth). An acrylic polymer layer was formed. A decorative layer was printed on the surface of the (meth) acrylic polymer layer with an inkjet printing machine (JV-33-130) to prepare a laminated film A.

The adhesive layer material having the blending ratio shown in Table 3 was coated on Purex (registered trademark) A-55 and dried at 100 ° C. for 10 minutes to prepare a laminated film B having a white adhesive layer having a thickness of 20 μm.

A graphic film was produced by laminating a (meth) acrylic polymer layer having a decorative layer of the laminated film A and an adhesive layer of the laminated film B so as to overlap each other.

Lumiror® T-60 on the polyurethane surface protective layer side was removed, and LD-K-1020, a protective film, was laminated. After removing Purex (registered trademark) A-55 on the adhesive layer side, the graphic film is laminated on an aluminum plate (based on A1050P JIS H4000, 1.0 mm x 165.5 mm x 330.5 mm), and the graphic film laminated plate. Was produced. The laminated plate was embossed with an embossing machine at room temperature to form a protrusion of a vehicle number. After removing the protective film, a color ink (NSP-UP 401K-1 Green) was coated only on the protrusions of the vehicle number by a roll coating method to form a print layer. It was dried in an oven at 120 ° C. for 20 minutes to prepare a license plate containing a graphic film.

<Example 3>
A license plate containing a graphic film was prepared in the same manner as in Example 2 except that the material for the (meth) acrylic polymer layer was changed to the blending ratio shown in Table 3.

<Example 4>
A license plate containing a graphic film was prepared in the same manner as in Example 2 except that the material for the (meth) acrylic polymer layer was changed to the blending ratio shown in Table 3.

<Example 5>
A license plate containing a graphic film was produced in the same manner as in Example 2 except that the above-mentioned solvent-based polyurethane solution was used as the material of the polyurethane surface protective layer and the drying conditions were changed to 120 ° C. for 20 minutes.

<Comparative example 1>
Without forming a polyurethane surface protective layer, the (meth) acrylic polymer layer material used in Example 3 was coated on Lumiror® T-60 and dried at 100 ° C. for 5 minutes to a thickness of 30 μm (meth). ) A license plate containing a graphic film was prepared in the same manner as in Example 2 except that an acrylic polymer layer was formed.

Table 3 shows the evaluation results of the license plate containing the graphic films obtained in Examples 1 to 5 and Comparative Example 1.

It will be apparent to those skilled in the art that the above embodiments and examples can be modified in various ways without departing from the basic principles of the present invention. It is also apparent to those skilled in the art that various improvements and modifications of the present invention can be carried out without departing from the spirit and scope of the present invention.

100, 200 Graphic film 110, 210, 330, 430, 520 Adhesive layer 120, 220, 342, 442, 542 Decorative layer 130, 215, 545 (meth) acrylic polymer layer 140, 240, 348, 448, 544 Polyurethane Surface protective layer 230, 344, 444 Bonding layer 300, 400 Retroreflective graphic film 310, 410 Retroreflective layer 312, 412 Cube corner element 314, 414 Structured surface 316, 416 Main surface 320, 420 Retroreflective structure 332, 432 Adhesive 334 Barrier layer 435 Reflective layer 336, 436, 536 Liner 338 Low refractive index layer 546 Print layer 350, 450 Ray 500 License plate 560 Aluminum plate 570 Blank press die
A part of the embodiments of the present disclosure will be described in [Item 1]-[Item 13] below.
[Item 1]
A graphic film for license plates that includes a polyurethane surface protective layer to which a printing layer is applied.
The polyurethane surface protective layer is a graphic film for a license plate containing a reaction product of a polyol having at least either a polyester skeleton or a polycarbonate skeleton and a polyfunctional aliphatic isocyanate, or an aqueous polyurethane.
[Item 2]
The license according to item 1, wherein the polyurethane surface protective layer contains the water-based polyurethane, and the water-based polyurethane has at least either a polyester skeleton or a polycarbonate skeleton and has a glass transition temperature of 80 ° C. or higher and 180 ° C. or lower. Graphic film for plates.
[Item 3]
Item 1 or 2 comprising a (meth) acrylic polymer layer containing a carboxyl group-containing (meth) acrylic polymer and having a first surface and a second surface facing the first surface, which can accept decorative inks. Graphic film for the listed license plate.
[Item 4]
The graphic film for a license plate according to item 3, wherein the (meth) acrylic polymer layer further contains a nitrogen atom-containing (meth) acrylic polymer.
[Item 5]
The graphic film for a license plate according to item 3 or 4, wherein a bonding layer is included between the polyurethane surface protective layer and the first surface of the (meth) acrylic polymer layer.
[Item 6]
The graphic film for a license plate according to any one of items 3 to 5, which comprises an adhesive layer on the second surface side of the (meth) acrylic polymer layer.
[Item 7]
The graphic film for a license plate according to item 6, wherein the (meth) acrylic polymer layer and / or the adhesive layer contains a white pigment.
[Item 8]
The graphic film for a license plate according to any one of items 1 to 7, which comprises a retroreflective layer.
[Item 9]
A license plate including the graphic film for the license plate according to any one of items 1 to 8.
[Item 10]
A step of providing a polyurethane surface protective layer to which a printing layer is applied, which comprises a reactant of a polyol having at least one of a polyester skeleton or a polycarbonate skeleton and a polyfunctional aliphatic isocyanate, or an aqueous polyurethane.
A decorative ink containing a carboxyl group-containing (meth) acrylic polymer on or above the polyurethane surface protective layer, and having a first surface on the surface protective layer side and a second surface facing the first surface. And the process of providing an acceptable (meth) acrylic polymer layer,
A step of providing a decorative ink on the second surface of the (meth) acrylic polymer layer, and
A method for producing a graphic film for a license plate, which comprises a step of providing an adhesive layer on or above the second surface of the (meth) acrylic polymer layer.
[Item 11]
The production method according to item 10, wherein the (meth) acrylic polymer layer further contains a nitrogen atom-containing (meth) acrylic polymer.
[Item 12]
A step of providing a polyurethane surface protective layer to which a printing layer is applied, which comprises a reactant of a polyol having at least one of a polyester skeleton or a polycarbonate skeleton and a polyfunctional aliphatic isocyanate, or an aqueous polyurethane.
A step of providing a bonding layer on or above the polyurethane surface protective layer, and
A step of providing a base material capable of receiving decorative ink, which has a first surface and a second surface facing the first surface, and
A step of providing decorative ink on the first surface of the base material, and
A step of bonding the first surface of the base material and the polyurethane surface protective layer via the bonding layer, and
How to make graphic film for license plates, including.
[Item 13]
The process of providing the base plate and
A step of providing a graphic film for a license plate according to any one of items 1 to 8 on the base plate to form a graphic film laminated plate.
The process of embossing or debossing the graphic film laminated plate,
A method for manufacturing a license plate, which comprises a step of forming a print layer on a convex portion or a concave portion of the graphic film laminated plate which has been embossed or debossed.

Claims (12)

A graphic film for license plates that includes a polyurethane surface protective layer to which a print layer is applied by baking finish .
The polyurethane surface protective layer contains an aqueous polyurethane, and the aqueous polyurethane has at least a polyester skeleton or a polycarbonate skeleton, and has a glass transition temperature of 80 ° C. or higher and 180 ° C. or lower, a graphic film for a license plate. Includes a carboxyl group-containing (meth) acrylic polymer, having a second surface facing the first surface and the first surface includes a decorative capable of accepting ink (meth) acrylic polymer layer, to claim 1 serial mounting license plates for the graphic film. The graphic film for a license plate according to claim 2 , wherein the (meth) acrylic polymer layer further contains a nitrogen atom-containing (meth) acrylic polymer. The graphic film for a license plate according to claim 2 or 3 , further comprising a bonding layer between the polyurethane surface protective layer and the first surface of the (meth) acrylic polymer layer. The graphic film for a license plate according to any one of claims 2 to 4 , further comprising an adhesive layer on the second surface side of the (meth) acrylic polymer layer. The graphic film for a license plate according to claim 5, wherein the (meth) acrylic polymer layer and / or the adhesive layer contains a white pigment. The graphic film for a license plate according to any one of claims 1 to 6 , which includes a retroreflective layer. A license plate including the graphic film for the license plate according to any one of claims 1 to 7 . A step of providing a polyurethane surface protective layer to which a printing layer is applied by baking finish , including an aqueous polyurethane having at least either a polyester skeleton or a polycarbonate skeleton and having a glass transition temperature of 80 ° C. or higher and 180 ° C. or lower .
A decorative ink containing a carboxyl group-containing (meth) acrylic polymer on or above the polyurethane surface protective layer, and having a first surface on the surface protective layer side and a second surface facing the first surface. a step of providing an acceptable (meth) acrylic polymer layer,
A step of providing a decorative ink on the second surface of the (meth) acrylic polymer layer, and
A method for producing a graphic film for a license plate, which comprises a step of providing an adhesive layer on or above the second surface of the (meth) acrylic polymer layer. The production method according to claim 9 , wherein the (meth) acrylic polymer layer further contains a nitrogen atom-containing (meth) acrylic polymer. A step of providing a polyurethane surface protective layer to which a printing layer is applied by baking finish , including an aqueous polyurethane having at least either a polyester skeleton or a polycarbonate skeleton and having a glass transition temperature of 80 ° C. or higher and 180 ° C. or lower .
A step of providing a bonding layer on or above the polyurethane surface protective layer, and
A step of providing a base material capable of receiving decorative ink , which has a first surface and a second surface facing the first surface, and
A step of providing decorative ink on the first surface of the base material, and
A step of bonding the first surface of the base material and the polyurethane surface protective layer via the bonding layer, and
How to make graphic film for license plates, including. The process of providing the base plate and
A step of providing the license plate graphic film according to any one of claims 1 to 7 on the base plate to form a graphic film laminated plate.
The process of embossing or debossing the graphic film laminated plate,
A method for manufacturing a license plate, which comprises a step of forming a printing layer on a convex portion or a concave portion of the graphic film laminated plate which has been embossed or debossed by baking coating .