JP6510318B2 - Graphic film for license plate, and license plate including graphic film and method of manufacturing the same - Google Patents

Description

  The present disclosure relates to a graphic film for a license plate, and a license plate including such a graphic film and a method of manufacturing the same, in particular including a graphic film suitable for a non-reflective license plate, and such a graphic film The present invention relates to a nonreflective license plate and a method of manufacturing the same.

  In the present Japan, a license plate (also referred to as a license plate, hereinafter the same in the present disclosure) forms a convex portion having a shape such as a place name and a number on a white paint aluminum plate by embossing. It is manufactured by printing a colored layer using inks, such as green.

  On the other hand, in the United States and the like, license plates having graphic, retroreflectivity and the like in addition to vehicle identification are used. Such a license plate can be manufactured by laminating a graphic film, a retroreflective sheet or the like on a base plate.

  Patent Document 1 (Japanese Patent Laid-Open No. 2000-508434) describes that “(a) a retroreflective element substantially arranged in a single layer, and (b) the retroreflective element is at least partially embedded. The bead bonding layer includes a spacing layer, (c) a specular reflection layer underlying the spacing layer, and (d) a bead bonding layer in which the retroreflective element is at least partially embedded. A retroreflective sheet comprising an aminoplast crosslinked polymer comprising urethane groups, said polymer having a glass transition temperature (Tg) of less than about 0 ° C. prior to crosslinking.

Japanese Patent Publication No. 2000-508434

  When producing a license plate having a graphic, direct printing on a white paint aluminum plate may result in insufficient adhesion of the ink or cracking of the printed graphic at the time of embossing. On the other hand, even when the graphic film is laminated on the base plate, the graphic film may be broken at the time of embossing, or the graphic film may be peeled off from the base at the time of embossing or over time. Also, since the aluminum plate generally used as the base plate of the license plate has a gray background color, it is necessary to completely hide the background color of the aluminum plate in order to make the color of the graphic bright and to improve the printing quality.

  The present disclosure provides a graphic film for a license plate having a high degree of whiteness, which can suppress the occurrence of defects such as breakage and lifting of the film during embossing and over time.

According to one embodiment of the present disclosure, there is provided a graphic film for a license plate, comprising: a base film layer having an upper surface and a lower surface; and a pressure sensitive adhesive layer disposed on the lower surface of the base film layer, The layer is
(A) Carboxyl group-containing tacky (meth) acrylic polymer having a glass transition temperature of −50 ° C. or less,
(B) A dispersant comprising an amino group-containing (meth) acrylic polymer free of monomer units derived from an aromatic vinyl monomer,
(C) At least one adhesive selected from the group consisting of rosin ester type, hydrogenated rosin type, terpene phenol type, styrene type, hydrogenated terpene phenol type, aromatic modified hydrogenated terpene resin, and aromatic modified terpene resin A imparting agent,
(D) A total of 100 parts by mass of the above-mentioned carboxyl group-containing tacky (meth) acrylic polymer, dispersant containing an amino group-containing (meth) acrylic polymer not containing a monomer unit derived from an aromatic vinyl monomer, and tackifier A graphic film is provided which comprises 10 parts by weight or more of a white pigment.

  According to another embodiment of the present disclosure, there is provided a license plate including a base plate and the above graphic film laminated on the base plate.

  According to yet another embodiment of the present disclosure, providing a base plate, laminating the graphic film on the base plate to form a laminated plate, and embossing or debossing the laminated plate License, including the steps of: forming a colored layer on the projections or recesses of the embossed or debossed laminated plate; and forming a surface protection layer to cover the graphic film and the colored layer A method of manufacturing a plate is provided.

  The license plate graphic film of the present disclosure can provide high whiteness with a white pressure-sensitive adhesive layer. In addition, the pressure-sensitive adhesive layer has excellent adhesion even though it contains a large amount of white pigment, so the graphic film is firmly adhered to the base plate against the internal stress remaining in the bent portion of the base film layer. it can. Therefore, it is possible to suppress the occurrence of defects such as breakage or floating of the graphic film during embossing and with time.

  It is to be understood that the above description should not be taken as disclosing all embodiments of the invention and all the advantages associated with the invention.

FIG. 1 is a schematic cross-sectional view of a graphic film for a license plate according to an embodiment of the present disclosure. FIG. 7 is a schematic cross-sectional view of a graphic film for a license plate according to another embodiment of the present disclosure. The preparation procedure of the license plate of one embodiment of this indication is shown in a schematic sectional view. The preparation procedure of the license plate of one embodiment of this indication is shown in a schematic sectional view. The preparation procedure of the license plate of one embodiment of this indication is shown in a schematic sectional view. The preparation procedure of the license plate of one embodiment of this indication is shown in a schematic sectional view. The preparation procedure of the license plate of one embodiment of this indication is shown in a schematic sectional view. The preparation procedure of the license plate of one embodiment of this indication, and the obtained license plate are shown in a schematic cross section.

  The present invention will hereinafter be described in more detail with reference to the drawings for the purpose of illustrating representative embodiments of the present invention, but the present invention is not limited to these embodiments. Like-numbered elements in different drawings indicate corresponding or corresponding elements in the drawings.

  In the present disclosure, "film" also includes an item called "sheet".

  In the present disclosure, “(meth) acrylic” means acrylic or methacrylic, and “(meth) acrylate” means acrylate or methacrylate.

  In the present disclosure, “pressure-sensitive adhesion” means initial tackiness (tack) in the working temperature range, for example, in the range of 0 ° C. or more and 50 ° C. or less, adheres to various surfaces with light pressure, and changes phase ( It refers to the property of a material or composition that does not exhibit liquid to solid).

  In the present disclosure, “transparent” means that the average light transmittance is about 60% or more, preferably about 80% or more, more preferably about 90% or more in the visible range (400 nm to 800 nm). .

  The graphic film for a license plate of one embodiment of the present disclosure includes a base film layer having an upper surface and a lower surface, and a pressure sensitive adhesive layer disposed on the lower surface of the base film layer.

  FIG. 1 shows a schematic cross-sectional view of a graphic film 10 for a license plate according to an embodiment of the present disclosure. The graphic film 10 includes a base film layer 12 having an upper surface and a lower surface, and a pressure sensitive adhesive layer 14 adhered to the lower surface of the base film layer 12. As shown in FIG. 1, the base film layer 12 and the pressure-sensitive adhesive layer 14 may be directly bonded, or may be bonded via a bonding layer. The base film layer 12 may have a surface treatment such as primer treatment or corona treatment on the adhesive surface with the pressure sensitive adhesive layer 14.

  As the base film layer, a resin film which does not break in the embossing process can be used, for example, polyurethane, acrylic resin, polyester, polyolefin, vinyl chloride resin, vinyl chloride-vinyl acetate resin, polycarbonate, polyimide, polyamide, A resin film such as polyester-amide can be used in a single layer or laminated. Among these, it is preferable to use a polyvinyl chloride film particularly in view of processability, durability and the like.

  The polyvinyl chloride film imparts processability and deformability to the graphic film, and can also function as a receptor for a printing layer formed using toner, ink and the like. The polyvinyl chloride film may comprise only polyvinyl chloride as the polymer component, for example additional polymers, such as thermoplastic polyurethanes, acrylonitrile-butadiene rubber (NBR), acrylonitrile, for the purpose of modifying properties such as impact resistance. -A butadiene-styrene copolymer (ABS), an ethylene-vinyl acetate copolymer (EVA), etc. may be included, for example in the amount of about 40 mass% or less, about 30 mass% or less, or about 20 mass% or less. The polyvinyl chloride film contains, for example, about 10% by mass or more of other additives such as plasticizers such as phthalic acid esters, adipic acid esters and trimellitic acid esters, antioxidants, ultraviolet light absorbers, and heat stabilizers. It may be included in an amount of about 13 wt% or more, or about 16 wt% or more, about 45 wt% or less, about 40 wt% or less, or about 35 wt% or less.

The base film layer may be white or colored in other colors. In one embodiment, the base film layer is colored white. Examples of white pigments that can be used for such coloring include zinc carbonate, zinc oxide, zinc sulfide, and titanium dioxide (titanium oxide). In the embodiment in which the base film layer is colored white, it is possible to more effectively conceal the color of the surface of the adherend on which the graphic film is to be formed, and to enhance the visibility, design and the like of the graphic film. It is advantageous to use titanium dioxide as a white pigment because of its high whiteness. The base film layer is a white pigment, for example, in an amount of about 10% by weight or more, about 15% by weight or more, or about 20% by weight or more, about 60% by weight or less, about 55% by weight or less, or about 50% by weight or less Including. The average primary particle size of the white pigment is generally about 0.10 μm or more, about 0.12 μm or more, or about 0.15 μm or more, about 0.50 μm or less, about 0.40 μm or less, or about 0.30 μm or less. The average primary particle size of the white pigment is the volume cumulative particle diameter D ₅₀ which can be determined using a laser diffraction / scattering particle size distribution measurement.

  The base film layer may be a single layer or a laminate of multiple layers. As the base film layer, films formed by various molding methods such as an extruded film, an extruded stretched film, a calendered film, a cast film and the like can be used, and in particular, a cast film can be advantageously used. The cast film with relatively low residual internal stress is excellent in the ability to conform to the surface of the adherend, and even if the license plate has a complicated embossed shape, the graphic film can be firmly bonded and / or aged The float of the graphic film can be effectively prevented.

  In one embodiment, the thickness of the base film layer is about 60 μm or more. The thickness of the base film layer may be 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. By setting the thickness of the base film layer in the above range, it is possible to prevent breakage of the graphic film at the time of embossing, and to form a graphic film for an embossed part having a complicated shape, for example, an embossed part including a curved part with high curvature. Adhere well to the graphic film and can impart high hiding power to the graphic film. In one preferred embodiment, the base film layer is a polyvinyl chloride film having a thickness of about 60 μm or more.

  The pressure-sensitive adhesive layer comprises (a) a carboxyl group-containing tacky (meth) acrylic polymer having a glass transition temperature of about -50 ° C. or less and (b) an amino group-containing monomer unit derived from an aromatic vinyl monomer A dispersant comprising a (meth) acrylic polymer (hereinafter, also simply referred to as “amino group-containing (meth) acrylic polymer” in the present disclosure), (c) rosin ester type, hydrogenated rosin type, terpene phenol type And at least one tackifier selected from the group consisting of styrenics, hydrogenated terpene phenols, aromatically modified hydrogenated terpene resins, and aromatically modified terpene resins, and (d) a white pigment. The white pigment is a total of 100 parts by mass of a carboxyl group-containing tacky (meth) acrylic polymer, a dispersant containing an amino group-containing (meth) acrylic polymer not containing a monomer unit derived from an aromatic vinyl monomer, and a tackifier To the pressure-sensitive adhesive layer in an amount of about 10 parts by weight or more. The pressure-sensitive adhesive layer can be formed from a pressure-sensitive adhesive composition containing the above-described components, or a crosslinked product thereof.

  It is known to add tackifiers to common acrylic pressure sensitive adhesives to modify the adhesion performance. On the other hand, the present inventors have further added a tackifier to an acrylic pressure-sensitive adhesive containing a large amount of white pigment such as titanium dioxide, so that the bent portion exists in the embossed license plate etc. It has also been found that a pressure sensitive adhesive can be obtained which can firmly adhere relatively thick graphic films. White pigments generally have a negative effect on the adhesion of pressure-sensitive adhesives since they are solid, and tackifiers themselves do not have adhesiveness, so those skilled in the adhesive field will find that pigments and tacks It is expected that the adhesion of the pressure sensitive adhesive will be greatly reduced if the combination of the imparting agent is used. This surprising result found by the present inventors is contrary to the expectation of such a person skilled in the art, and a graphic film having high whiteness and excellent adhesion using an acrylic pressure-sensitive adhesive having a hiding property. Provide significant technical and economic benefits, such as

  In the pressure-sensitive adhesive composition of the present disclosure, since an amino group-containing (meth) acrylic polymer not containing a monomer unit derived from an aromatic vinyl monomer improves the dispersibility of the white pigment, a large amount of white pigment is used. It can be filled in to enhance the hiding power of the pressure sensitive adhesive. In addition, the white pigment is effectively dispersed in the pressure-sensitive adhesive with the amino group-containing (meth) acrylic polymer, whereby the adhesion and hiding power of the pressure-sensitive adhesive can be maintained at a high level.

The carboxyl group-containing tacky (meth) acrylic polymer comprises a monoethylenically unsaturated monomer as a main component, and a monoethylenically unsaturated monomer (carboxyl group-containing monoethylenically unsaturated monomer) containing a carboxyl group. It can be obtained by copolymerization. The monoethylenically unsaturated monomer is the main component of the polymer, and is generally represented by the formula CH ₂ 1CR ¹ COOR ² (wherein, R ¹ is hydrogen or methyl, R ² is linear or cyclic) Or, in addition to those represented by branched alkyl group, phenyl group, alkoxyalkyl group, phenoxyalkyl group, hydroxyalkyl group or cyclic ether group), styrene, .alpha.-methylstyrene, vinyl toluene and the like Also included are aromatic vinyl monomers, vinyl esters such as vinyl acetate, and unsaturated nitriles such as acrylonitrile and methacrylonitrile. Examples of monoethylenically unsaturated monomers represented by the formula CH ₂ CRCR ¹ COOR ² include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isoamyl (meth) acrylate, and n- Hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, etc. Alkyl (meth) acrylates; phenoxyalkyl (meth) acrylates such as phenoxyethyl (meth) acrylate; methoxypropyl (meth) acrylate, 2-methoxybutyl (meth) acrylate Alkoxyalkyl (meth) acrylates; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate; glycidyl (meth) acrylate, tetrahydro Mention may be made of cyclic ether-containing (meth) acrylates such as furfuryl (meth) acrylate. As the monoethylenically unsaturated monomer, one or more monoethylenically unsaturated monomers can be used, as needed.

  As a carboxyl group-containing monoethylenically unsaturated monomer, unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; unsaturated dicarboxylic acids such as itaconic acid, fumaric acid, citraconic acid and maleic acid; ω-carboxypolycaprolactone Monoacrylate, monohydroxyethyl (meth) acrylate phthalate, β-carboxyethyl acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyl oxyethyl hexahydrophthalic acid and the like can be mentioned.

  The glass transition temperature (Tg) of the carboxyl group-containing tacky (meth) acrylic polymer is about −50 ° C. or less, whereby a pressure-sensitive adhesive having good adhesion while containing a large amount of white pigment such as titanium dioxide Agents can be provided. In some embodiments, the glass transition temperature (Tg) of the carboxyl group-containing tacky (meth) acrylic polymer is about -52 ° C. or less, or about -55 ° C. or less, about -80 ° C. or more, about- It is 75 ° C or more, or about -70 ° C or more. When the Tg is lower than these ranges, the cohesion of the pressure sensitive adhesive tends to be reduced. On the other hand, if the Tg is higher than these ranges, the adhesion of the pressure sensitive adhesive tends to be reduced.

  The carboxyl group-containing tacky (meth) acrylic polymer is, for example, about 80 parts by weight or more, about 85 parts by weight or more, or about 90 parts by weight or more, about 99.5 parts by weight or less, about 99 parts by weight of monoethylenically unsaturated monomer. About 0.5 parts by mass or less, about 0.5 parts by mass or more, about 1 part by mass or more, or about 5 parts by mass or more, about 20 parts by mass or less of the carboxyl group-containing monoethylenically unsaturated monomer It can be obtained by copolymerizing in a proportion of 15 parts by mass or less, or about 10 parts by mass or less.

  The carboxyl group-containing tacky (meth) acrylic polymer has tackiness at normal temperature (about 25 ° C.) and imparts pressure-sensitive adhesiveness to the pressure-sensitive adhesive. The weight average molecular weight of the carboxyl group-containing tacky (meth) acrylic polymer is generally about 100,000 or more, about 200,000 or more, or about 300,000 or more, less than about 2,000,000, about 1,000, It can be less than 000, or less than about 800,000. If the molecular weight is too high, the dispersibility of white pigments such as titanium dioxide tends to be reduced. The weight average molecular weight in the present disclosure means a molecular weight converted to standard polystyrene by GPC method.

  The carboxyl group-containing tacky (meth) acrylic polymer can be used as a main component of the pressure-sensitive adhesive composition. The blending amount of the carboxyl group-containing tacky (meth) acrylic polymer is about 30 parts by mass or more, about 35 parts by mass or more, or about 40 parts by mass or more, based on 100 parts by mass of the entire pressure-sensitive adhesive composition. About 88 parts by weight or less, about 75 parts by weight or less, or about 60 parts by weight or less.

  An amino group-containing (meth) acrylic polymer not containing a monomer unit derived from an aromatic vinyl monomer, which is used as a dispersant in the present disclosure, has a monoethylenically unsaturated monomer as a main component, and an amino group-containing non-monomer. It is obtained by copolymerizing with a saturated monomer, and does not contain an aromatic vinyl monomer as a component of the polymer. The amino group-containing (meth) acrylic polymer not only acts as a dispersant for white pigments such as titanium dioxide but also interacts with the carboxyl group-containing tacky (meth) acrylic polymer to cause aggregation of the pressure sensitive adhesive. It is thought that it also contributes to enhancing the power. The monoethylenically unsaturated monomer is the same as in the case of the carboxyl group-containing sticky (meth) acrylic polymer except for the aromatic vinyl monomer, and, if necessary, one or more monoethylenically unsaturated monomers. Monomers can be used. The aromatic vinyl monomers include styrene, α-methylstyrene, vinyl toluene, vinyl naphthalene, vinyl anthracene, vinyl anthraquinone, (meth) acrylamides of aromatic amines, (meth) acrylates of hydroxyl group-containing aromatic compounds, and the like. Aromatic amines include aniline, benzylamine, naphthylamine, aminoanthracene, aminoanthraquinone or derivatives thereof. Examples of the hydroxyl group-containing aromatic compound include hydroxyl group-containing compounds corresponding to the above-mentioned aromatic amines.

  As amino group-containing unsaturated monomers, dialkylaminoalkyl (meth) acrylates such as N, N-dimethylaminoethyl acrylate (DMAEA), N, N-dimethylaminoethyl methacrylate (DMAEMA); N, N-dimethylaminopropyl acrylamide ( And dialkylaminoalkyl (meth) acrylamides such as DMAPAA) and N, N-dimethylaminopropyl methacrylamide; and dialkylaminoalkyl vinyl ethers such as N, N-dimethylaminoethyl vinyl ether and N, N-diethyl aminoethyl vinyl ether. If necessary, one or more amino group-containing unsaturated monomers can be used.

  The amino group-containing (meth) acrylic polymer is, for example, about 80 parts by mass or more, about 85 parts by mass or more, or about 90 parts by mass or more, about 99.5 parts by mass or less, about 99 parts by mass of monoethylenically unsaturated monomer Or less, or about 95 parts by mass or less, about 0.5 parts by mass or more, about 1 part by mass or more, or about 5 parts by mass or more, about 30 parts by mass or less, about 20 parts by mass or less of the amino group-containing unsaturated monomer Or it can obtain by copolymerizing in the ratio of about 10 mass parts or less.

  Although the weight average molecular weight of the amino group-containing (meth) acrylic polymer is not particularly limited, for example, about 1,000 or more, about 5,000 or more, about 10,000 or more, about 500,000 or less, about 200,000 or less Or about 100,000 or less.

  The compounding amount of the amino group-containing (meth) acrylic polymer is about 1 part by mass or more, about 2 parts by mass or more, about 4 parts by mass or more, or 100 parts by mass of the entire pressure-sensitive adhesive composition. It may be 8 parts by mass or more, about 25 parts by mass or less, about 20 parts by mass or less, or about 15 parts by mass or less.

  In some embodiments, the glass transition temperature (Tg) of the amino group-containing (meth) acrylic polymer is about 0 ° C. or more, about 20 ° C. or more, or about 40 ° C. or more, about 150 ° C. or less, about 135 ° C. or less. Or it is about 120 degrees C or less.

The glass transition temperature (Tg) of the carboxyl group-containing tacky (meth) acrylic polymer and the amino group-containing (meth) acrylic polymer is determined by the formula of FOX (each polymer is copolymerized from n types of monomers). The following equation can be obtained.

  The copolymerization of these polymers is preferably carried out by radical polymerization, and known polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization and bulk polymerization can be used. As an initiator, organic peroxides such as benzoyl peroxide, lauroyl peroxide, bis (4-tert-butylcyclohexyl) peroxydicarbonate, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2) -Methylbutyronitrile), dimethyl-2,2-azobis (2-methylpropionate), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-methylpropionic acid) Azo-based polymerization initiators such as dimethyl and 2,2′-azobis (2,4-dimethylvaleronitrile) (AVN) can be used. The amount of the initiator used is generally about 0.01 parts by weight or more, or about 0.05 parts by weight or more, about 5 parts by weight or less, or about 3 parts by weight or less based on 100 parts by weight of the monomer mixture.

  As a tackifier to be contained in the pressure-sensitive adhesive composition, it is preferable to use a tackifier that exhibits compatibility with at least an acrylic resin. For example, rosin ester type, hydrogenated rosin type, terpene phenol type, styrene type, hydrogenated terpene phenol type, aromatic modified hydrogenated terpene resin, aromatic modified terpene resin, etc. can be used. Among them, it is preferable to use a rosin ester-based tackifier. The tackifier may be used alone or in combination of two or more.

  Natural rosin ester which is an ester product of monohydric alcohol such as methanol and ethanol, or polyhydric alcohol such as glycerin and pentaerythritol as rosin ester, and ester of natural rosin (eg gum rosin, tall oil rosin, wood rosin etc); Or modified rosin ester which is esterified product of polyhydric alcohol and modified rosin such as hydrogenated rosin, disproportionated rosin or acid modified rosin; ester of the monohydric or polyhydric alcohol and polymerized rosin (especially polymerized natural rosin) And polymeric rosin esters that are Natural rosin, hydrogenated rosin, disproportionated rosin, acid-modified rosin and polymerized rosin may be purified by recrystallization or the like. These resinous rosins are generally resin acids such as abietic acid, neoabietic acid, dehydroabietic acid, parastringic acid, levopimaric acid, pimaric acid, isopimaric acid, sandaracopimaric acid, tetrahydroabietic acid, dehydroabietic acid, dihydroabietic acid, Or a mixture of these.

  In some embodiments, the softening point of the rosin ester is about 70 ° C. or more, about 75 ° C. or more, or about 80 ° C. or more, about 130 ° C. or less, about 120 ° C. or less, or about 110 ° C. or less. By using a rosin ester having a softening point in the above range as a tackifier, it is possible to obtain a pressure-sensitive adhesive which is excellent in the adhesive strength at high temperature and in which the change in adhesive strength with time is small. The high adhesion at high temperatures greatly contributes to the prevention of the film film from floating over time, which may be placed in a high temperature environment such as summer daytime. The softening point of rosin ester can be measured by a thermomechanical analyzer (TMA).

  In some embodiments, the acid number (mg KOH / g) of the rosin ester is about 1 or more, about 2 or more, or about 3 or more, about 45 or less, about 30 or less, or about 20 or less. The acid value of the rosin ester can be determined in accordance with JIS K 0070: 1992 (potentiometric titration method).

  In some embodiments, the color number of the rosin ester is about 9 or less, about 5 or less, or about 3 or less. The color number of the rosin ester can be determined in accordance with the Gardner colorimetric method (JIS K0071-2).

  Commercially available rosin esters such as, for example, HARITAC F 85 (stabilized rosin ester), HARITAC F 105 (stabilized rosin ester), HARITAC 4851 (modified rosin ester), HALIESTER DS-90 (rosin modified special synthetic resin), Neotol (trademark) G2 (stabilized rosin half ester) (all are from Harima Chemicals Group, Inc.), PermalynTM 5095, ForalTM 85-E, PermalynTM 6110-E, ForalTM 105-E (any) Eastal Co., Ltd., Foral (trademark) 3085, Foral (trademark) 85 (all are made by PINOVA Corporation), etc. are mentioned.

  The amount of the tackifier used is about 3 parts by mass or more, about 5 parts by mass or more, about 10 parts by mass or more, in terms of solid content, with respect to 100 parts by mass of the carboxyl group-containing tacky (meth) acrylic polymer It can be about 20 parts by weight or more, about 150 parts by weight or less, about 130 parts by weight or less, or about 110 parts by weight or less.

  White pigments provide hiding properties to pressure sensitive adhesives. As the white pigment, conventionally known white pigments can be used. Such white pigments include, for example, zinc carbonate, zinc oxide, zinc sulfide, and titanium dioxide (titanium oxide). Titanium dioxide can be used particularly advantageously because of its high whiteness and excellent dispersibility. Without being bound by any theory, white pigments, in particular titanium dioxide, form intermolecular crosslinks of carboxyl group-containing tacky (meth) acrylic polymers and contribute to enhancing the cohesion of pressure-sensitive adhesives It is believed that The white pigment may be particles of various shapes such as spheres, needles, flat plates or flakes, and is preferably spherical particles because of its good dispersibility. The white pigment may be surface-treated with a coupling agent such as silane or titanate in order to improve dispersibility.

The average primary particle size of the white pigment is generally about 0.10 μm or more, about 0.12 μm or more, or about 0.15 μm or more, about 0.50 μm or less, about 0.40 μm or less, or about 0.30 μm or less. By setting the average primary particle size of the white pigment in the above range, the white pigment can be more uniformly dispersed in the pressure sensitive adhesive. The average primary particle size of the white pigment is the volume cumulative particle diameter D ₅₀ which can be determined using a laser diffraction / scattering particle size distribution measurement.

  The blending amount of the white pigment is a total of a carboxyl group-containing tacky (meth) acrylic polymer, a dispersant containing an amino group-containing (meth) acrylic polymer not containing a monomer unit derived from an aromatic vinyl monomer, and a tackifier The amount is about 10 parts by mass or more with respect to 100 parts by mass, whereby sufficient concealability can be imparted to the pressure sensitive adhesive. In some embodiments, the blending amount of the white pigment is a dispersion containing a carboxyl group-containing sticky (meth) acrylic polymer, and an amino group-containing (meth) acrylic polymer free of monomer units derived from an aromatic vinyl monomer. 15 parts by weight or more, about 20 parts by weight or more, about 25 parts by weight or more, or about 30 parts by weight or more, about 150 parts by weight or less, about 120 parts by weight or less based on 100 parts by weight in total of the agent and the tackifier Or about 100 parts by mass or less.

  The pressure-sensitive adhesive composition may contain a colorant comprising a white pigment and a dispersant comprising an amino group-containing (meth) acrylic polymer free of monomer units derived from an aromatic vinyl monomer. Stabilizing more white pigment in the pressure sensitive adhesive composition by including the white pigment in the pressure sensitive adhesive composition in the form of a colorant, ie predispersed in a dispersant comprising a polymer It can be dispersed.

  The colorant can be obtained by mixing the dispersant and the white pigment by a known method. For mixing, for example, a paint shaker (made by Shinky Co., Ltd.), a sand grind mill, a ball mill, an attritor mill, a triple roll mill or the like can be used. If necessary, an aqueous solvent or an organic solvent may be used upon mixing. The coloring agent can maintain the well-dispersed state of the particles of the white pigment without aggregation even after a long time (for example, about one month) after preparation as in the case immediately after the preparation.

  The amount of the dispersant contained in the colorant may be 100% by mass of the dispersant contained in the pressure-sensitive adhesive composition.

  The amount of white pigment contained in the colorant may be 100% by mass of the white pigment contained in the pressure-sensitive adhesive composition.

  In the colorant, the compounding amount of the white pigment is about 100 parts by mass or more, about 500 parts by mass or more, or about 1000 parts by mass or more, about 10000 parts by mass or less, about 5000 parts by mass or less with respect to 100 parts by mass of the dispersant. Or about 2000 parts by weight or less.

  The pressure sensitive adhesive composition may comprise a crosslinker. A crosslinking agent can be used to crosslink at least one of a carboxyl group-containing tacky (meth) acrylic polymer and an amino group-containing (meth) acrylic polymer not containing a monomer unit derived from an aromatic vinyl monomer, Thus, the cohesion of the pressure-sensitive adhesive layer can be enhanced, and the adhesion can be maintained even at high temperatures. As a crosslinking agent, for carboxyl group-containing sticky (meth) acrylic polymers, for example, a bisamide crosslinking agent (for example, 1,1′-isophthaloyl-bis (2-methylaziridine)), an aziridine crosslinking agent (for example, Chemitite PZ33 manufactured by Nippon Shokubai Co., Ltd., NeoCryl CX-100 manufactured by Avicia Co., Ltd., carbodiimide type crosslinking agent (for example, Carbodilite V-03, V-05, V-07 manufactured by Nisshinbo Chemical Co., Ltd.), epoxy type crosslinking agent (for example, Soken Chemical Co., Ltd. E-AX, E-5XM and E5C; N, N, N ', N'-tetraglycidyl-1,3-benzenedi (methanamine), isocyanate type crosslinking agent (for example, Nippon Polyurethane Industry Co., Ltd. Coronate L, Coronate HK, Bayer Deathmod H, Deathmod , It can be used Desmodur I) and the like. For amino group-containing (meth) acrylic polymers, epoxy-based crosslinking agents (for example, E-AX, E-5XM and E5C manufactured by Soken Chemical Co., Ltd .; N, N, N ′, N′-tetraglycidyl-1, 3-benzenedi (methanamine)), isocyanate type crosslinking agent (for example, Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate HK, Desmodur H manufactured by Bayer, Desmodur W, Desmodur I) and the like can be used. In one preferred embodiment, the crosslinking is formed using at least one of a bisamide crosslinking agent and an epoxy crosslinking agent.

  The addition amount of the crosslinking agent is the total of a carboxyl group-containing tacky (meth) acrylic polymer, a dispersant containing an amino group-containing (meth) acrylic polymer not containing a monomer unit derived from an aromatic vinyl monomer, and a tackifier About 100 parts by mass, it can be about 0.01 parts by mass or more, about 0.03 parts by mass or more, or about 0.05 parts by mass or more, and about 0.5 parts by mass or less, about 0.3 parts by mass Or less, or about 0.2 parts by weight or less. By making the addition amount of a crosslinking agent into the said range, the cohesion force of a pressure sensitive adhesive layer can be adjusted, and the improvement of the adhesive force of a graphic film, and float prevention can be made compatible.

  The pressure sensitive adhesive composition may contain, as other components, fillers such as talc, kaolin, calcium carbonate, aluminum flakes, fumed silica, alumina, nanoparticles, antioxidants, UV stabilizers and the like.

  The pressure-sensitive adhesive composition comprises a carboxyl group-containing tacky (meth) acrylic polymer, a dispersant containing an amino group-containing (meth) acrylic polymer, a tackifier, and a white pigment, which are known methods. It can be obtained by using and mixing.

  For example, each component may be put into a mixing vessel almost at the same time, and mixed using a paint shaker (made by Shinky Co., Ltd.), a sand grind mill, a ball mill, an attritor mill, a triple roll mill or the like. If necessary, an aqueous solvent or an organic solvent may be used upon mixing. The white pigment may be mixed in an aqueous solvent or an organic solvent and then mixed with other components.

  As described above, after the colorant is prepared by mixing the whole or a part of the dispersant and the whole or a part of the white pigment, the obtained colorant and the remaining components are mixed by a known method to Pressure sensitive adhesive compositions can also be prepared.

  Graphic films can be produced by known methods. For example, a solution in which the pressure-sensitive adhesive composition is dissolved in an organic solvent is applied onto a liner by knife coating, bar coating or the like and dried to form a pressure-sensitive adhesive layer. A base film layer can be laminated by dry lamination etc. on the obtained pressure sensitive adhesive layer, and a graphic film can be formed.

  The thickness of the pressure-sensitive adhesive layer is generally about 5 μm or more, about 10 μm or more, or about 20 μm or more, about 100 μm or less, about 80 μm or less, or about 50 μm or less. By setting the thickness of the pressure-sensitive adhesive layer in the above range, the graphic film can be firmly adhered to the adherend, and the graphic film can be provided with high hiding power.

  The graphic film may have a liner on the surface of the pressure sensitive adhesive layer opposite to the base film layer. Examples of liners include paper; plastic materials such as polyethylene, polypropylene, polyester and cellulose acetate; and papers coated with such plastic materials. These liners may have surfaces that have been release treated with silicone or the like. The thickness of the liner is generally about 5 μm or more, about 15 μm or more, or about 25 μm or more, about 300 μm or less, about 200 μm or less, or about 150 μm or less.

  The graphic film may have other layers, such as a printing layer, a surface protective layer, a colored layer, a bonding layer, etc., between the upper surface of the base film layer or between the base film layer and the pressure-sensitive adhesive layer. For example, the graphic film of one embodiment of the present disclosure further includes a print layer disposed on top of the base film layer. The graphic film may further comprise a surface protection layer disposed on the printing layer. FIG. 2 shows a schematic cross-sectional view of the graphic film 10 of such an embodiment. The graphic film 10 has a print layer 16 on the upper surface of the base film layer 12, and the surface protective layer 18 is adhered to the upper surface of the base film layer 12 via the bonding layer 17.

  The print layer 16 can be used to impart decorativeness or design to a graphic film. For example, when a graphic film is used for a license plate, a pattern, a pattern or the like can be given to a background portion other than the characters of the license plate. The print layer 16 can be formed on the base film layer using a colorant such as toner and ink. The print layer can also be formed on the surface protective layer or between the base film layer and the pressure sensitive adhesive layer. The printing layer can be formed by using a printing technique such as gravure printing, electrostatic printing, screen printing, inkjet printing, offset printing and the like. The thickness of the print layer can vary, and generally, when using solvent-based inks, it is about 1 μm or more, or about 2 μm or more, about 8 μm or less, or about 5 μm or less. When a 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.

In some embodiments, it is desirable to ensure that the reading of the license plate registration number by an Automatic License Plate Reader (ALPR) is not impeded by the printed image. Since an infrared camera is usually used for ALPR, it is desirable to suppress the use of a black ink having high infrared absorptivity in the registration number identification region which is a region necessary for identification of a registration number by ALPR. For example, a dot area ratio which is an area ratio of black ink dots contained in any 10 mm square or 10 mm ² circular area is about 70% or less, preferably about 70% or less in the registration number identification area. It may be 50% or less, more preferably about 30% or less, and particularly preferably 0%.

  Various resin films can be used as the surface protective layer. The surface protective layer desirably has flexibility and / or stretchability. As a resin used for such a surface protective layer, polyvinyl chloride, a vinyl chloride-vinyl acetate copolymer, a polyurethane, an acrylic resin, a resin containing at least one of polyolefins, or a combination thereof can be mentioned. By using these resins, when the graphic film is used for a license plate, breakage of the graphic film is unlikely to occur, and the graphic film can be made to follow well the bending portion formed by embossing. The surface protective layer is preferably at least transparent to visible light. The thickness of the surface protective layer may vary, and can generally be about 40 μm or more, about 50 μm or more, or about 60 μm or more, about 200 μm or less, about 150 μm or less, or about 100 μm or less.

  It is desirable to use a polyurethane that is transparent in the visible range and in the infrared range (400 nm to 1000 nm) as a surface protective layer. Such polyurethanes include a reaction product of a polyol having at least one of a polyester skeleton or a polycarbonate skeleton and a trifunctional or higher aliphatic isocyanate and having a glass transition temperature Tg of about 50 ° C. or higher, at 120 ° C. Those having a loss tangent tan δ of about 0.1 or less can be preferably used. Polyurethane surface protection layers having these properties generally have high crosslink density and can impart weatherability and chemical resistance to graphic films. Such a polyurethane surface protective layer applies or sprays a curable composition containing at least a polyester skeleton or a polycarbonate skeleton and a trifunctional or higher aliphatic isocyanate onto a graphic film as a liquid. It can be formed by reacting polyol and isocyanate by in-situ heating. Such curable compositions have sufficient strength, weatherability and chemical resistance even when cured at relatively low temperatures, such as about 150 ° C. or less, about 120 ° C. or less, about 100 ° C. or less, or about 80 ° C. or less The reaction product can be provided. In some preferred embodiments, the trifunctional or higher aliphatic isocyanate contains an isocyanurate of isophorone diisocyanate, an adduct, or both of them, and a polyurethane surface protection having particularly excellent weatherability and chemical resistance. Layers can be formed.

  In one embodiment, a colored layer is disposed between the base film layer and the surface protective layer, and the colored layer comprises a copolymer resin containing at least a vinyl chloride unit and a vinyl acetate unit, and a pigment. It is formed from “Thermoplasticity” used for the ink composition in the present disclosure means that the colored layer formed from the ink composition has thermoplasticity. In some embodiments, the thermoplastic ink composition does not contain a crosslinking agent or a curing agent. A colored layer formed from a thermoplastic ink composition is relatively flexible as compared to a colored layer formed from a thermosetting or radiation curable ink composition, so it is easily deformed during processing or molding of a graphic film, Moreover, it is advantageous in the point that it is hard to generate | occur | produce appearance defects, such as a crack, with respect to the temperature change at the time of use of graphic film. When the crosslinking agent and / or the curing agent are not included, the colored layer can be formed at a relatively low temperature, for example, about 110 ° C. or less, about 100 ° C. or less, or about 80 ° C. or less because heat curing treatment is unnecessary. By combining the colored layer formed from the thermoplastic ink composition with the polyurethane surface protective layer of the present disclosure, it is possible to obtain a graphic film excellent in weather resistance and chemical resistance while having the above advantages. The thickness of the colored layer may vary, and can generally be about 5 μm or more, about 6 μm or more, or about 8 μm or more, about 30 μm or less, about 25 μm or less, or about 20 μm or less.

  As the bonding layer 17, a commonly used acrylic, polyolefin, polyurethane, polyester, rubber, etc. solvent type, emulsion type, pressure sensitive type, thermal type, thermosetting type or ultraviolet curing type adhesive is used. It is possible to use a thermosetting polyurethane adhesive advantageously. The thickness of the bonding layer can generally be about 0.05 μm or more, about 0.5 μm or more, or about 5 μm or more, about 100 μm or less, about 50 μm or less, or about 20 μm or less.

  The graphic film can be adhered to an adherend such as an aluminum plate to form an article such as a license plate or a sign. In one embodiment of the present disclosure, there is provided a license plate including a base plate and the above graphic film laminated on the base plate. In one embodiment, the license plate is non-reflective.

  The base plate of the license plate is generally a metal plate or a resin plate. As a metal plate, an aluminum plate, a stainless steel plate, an iron plate etc. are mentioned. A polycarbonate board, a polyester board, a polyvinyl chloride board etc. are mentioned as a resin board. If necessary, these plate materials may be formed into a shape such as a frame.

  For example, signs such as license plates, traffic signs, etc. generally comprise letters, graphics, patterns or combinations thereof combining alphabet and numbers. In one embodiment, the appearance of the sign is defined by the government and / or jurisdiction. In another embodiment, the display unit can be formed by a colored layer. In still another embodiment, for example, in the license plate, the display portion can be formed by combining the embossed portion (convex portion) or the debossed portion (concave portion) and the colored 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.

  A method of manufacturing a license plate according to an embodiment of the present disclosure includes the steps of providing a base plate, laminating a graphic film on the base plate to form a laminated plate, and embossing or debossing the laminated plate. And forming a colored layer on the projections or depressions of the embossed or debossed laminated plate, and forming a surface protection layer to cover the graphic film and the colored layer.

  Although the method of manufacturing the license plate is exemplarily described with reference to FIGS. 3A to 3F, the method of manufacturing the license plate is not limited thereto.

  The graphic film 10 shown in FIG. 3A has a liner 19 on a pressure sensitive adhesive layer (not shown).

  As shown in FIG. 3B, the liner 19 is removed, and the pressure sensitive adhesive layer of the graphic film 10 is adhered and laminated to a base plate 22 such as an aluminum plate to form a laminated plate.

  Next, as shown in FIG. 3C, using a blank press die 30, the laminated plate is blank-pressed into a desired size and cut out.

  As shown in FIG. 3D, the cut out laminated plate is embossed / debossed to form the display portion and the edge frame portion of the license plate. In FIG. 3D, 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. 3E, the colored layer 24 is formed by roll coating or the like on the convex portion (embossed portion) of the embossed laminated plate. The colored layer 24 is used for the purpose of imparting distinctiveness by giving readable portions such as letters, numerals, and figures to the embossed portion or debossed portion of the license plate. The colored layer generally comprises an organic or inorganic pigment, and a binder resin such as vinyl chloride-vinyl acetate copolymer containing a vinyl chloride unit and a vinyl acetate unit, and, if necessary, a solvent, an ultraviolet absorber, a light stabilizer, a thermal agent It can be formed using an ink composition containing a stabilizer, a dispersant, a plasticizer, a flow improver, a leveling agent and the like.

  As shown in FIG. 3F, a surface protective layer is formed by applying or spraying a curable composition which is transparent in the visible range including polyurethane and the like so as to cover the graphic film 10 and the colored layer 24, heating and drying or curing. Form 26. For example, a curable composition containing at least a polyester skeleton or a polycarbonate skeleton and a trifunctional or higher aliphatic isocyanate is applied or sprayed, for example, at a temperature of about 80 ° C. to 150 ° C. for about 5 to 15 minutes The polyol and the isocyanate can be reacted by heating to form the polyurethane surface protective layer 26. Thus, the license plate 20 can be manufactured.

  The graphic film of the present disclosure can be applied to, for example, traffic signs, billboards, etc. in addition to the license plate described above. In addition, the graphic film of the present disclosure can be used as a decorative film or sheet of a car or a building.

  In the present specification, the following abbreviations shown in Table 1 may be used.

  Although specific embodiments of the present disclosure are illustrated in the following examples, the present invention is not limited thereto. All parts and percentages are by weight unless otherwise stated.

<Evaluation method>
<Presence of breakage during embossing>
Magenta was printed on the entire surface of the graphic film using an inkjet printer JV5 (MIMAKI ENGINEERING CO., LTD., Shinagawa-ku, Tokyo, Japan). A transparent polyvinyl chloride film RG5333R (3M Japan Co., Ltd., Shinagawa-ku, Tokyo, Japan) was bonded to the printing surface as a surface protection film. After that, a graphic film with a surface protection film is pasted on a 1 mm thick aluminum plate (A1050P, Asahi Bee Techno, Shinagawa-ku, Tokyo, Japan), and an embossing press (Amada, Isehara, Kanagawa, Japan) , Letters and numbers were embossed, and the presence or absence of breakage, cracks, etc. in the embossed portion was visually confirmed.

<Whiteness>
An optical color meter (SM-7, Suga Test Instruments Co., Ltd., Shinjuku, Japan) after attaching a graphic film to a 1 mm thick aluminum plate (A1050P, Asahi Bee Techno, Shinagawa-ku, Tokyo, Japan) Y value was measured in section (B), and also the whiteness was visually evaluated according to the following criteria.
Whiteness standard: 2 or more was passed according to the following definition.
1 Whiteness is low, grayish white appears 2 Somewhat dark, but judged to be white 3 judged to be white 4 judged to be white, feels high whiteness

<Embossed part float>
After pasting the graphic film on a 1 mm thick aluminum plate (A1050P, Asahi Bee Techno Co., Ltd., Shinagawa-ku, Tokyo, Japan), emboss with an embossing press (Amada Co., Ltd., Isehara, Kanagawa, Japan) After application, the cross section of the embossed part was enlarged about 65 times with an optical microscope (SZX12, Olympus Corporation, Shinjuku-ku, Tokyo, Japan), and the presence or absence of floating between the graphic film and the aluminum plate was observed .

<Cut corner test>
The following method was tested for the followability to the unevenness (corresponding to the emboss) of the base film of the graphic film. A graphic film is cut to a width of 70 mm and a length of 25 mm, placed on the smooth surface of an aluminum plate with a concave groove of 10 mm wide and 3 mm deep, and a plastic squeegee is used to follow the concave groove of the aluminum plate Then I attached the graphic film. After pasting, it was aged for 24 hours at an ambient temperature of 23 ° C., and then heated for 10 minutes at 65 ° C. The width of the film adhered to the bottom of a concave groove of 10 mm in width was measured and evaluated according to the following criteria .
Filled corner test criteria: 3 or more passed according to the following definition.
1 Bonding width is 0 mm (the film completely floats from the bottom of the concave groove)
2 Bonding width exceeds 0 mm and less than 1 mm 3 Bonding width is 1 mm or more and 2.5 mm or less 4 Bonding width exceeds 2.5 mm

<Adhesive force>
A graphic film is cut into a width of 25 mm and a length of 150 mm, and after adhering to an aluminum plate under an environment of 20 ° C., it is aged for 48 hours under an environment of 20 ° C., and a tensile tester (Tensilon “O (Registered trademark) "was used to measure the adhesion when peeled 180 degrees at a speed of 300 mm / min.

<Optical color density>
A cyan, magenta, yellow, and black inks are printed at 100% density on a graphic film with a solvent-based inkjet printer (JV5, Mimaki Engineering, Inc., Shinagawa-ku, Tokyo, Japan), and a color densitometer (X- Measurement of the OD value (optical color density) was carried out with Rite 500 Series, X-Rite Inc., Grand Rapids, Michigan, USA.

<Formation of base film layer>
On a release-treated backing film, a solution of polyvinyl chloride resin, plasticizer, and pigment 1 dispersed in an aromatic hydrocarbon solvent is coated with a knife coater to a dry thickness of about 50 μm, Drying was performed at 180 ° C. Thereafter, the above solution is again coated on the obtained polyvinyl chloride film so that the total thickness of the polyvinyl chloride film after drying is about 90 μm, and drying is performed at 200 ° C. to obtain a polyvinyl chloride film. A base film layer was formed.

<Manufacture of dispersant-amino group-containing (meth) acrylic polymer 1 (HAP1)->
60 parts by mass of MMA, 34 parts by mass of BMA, and 6 parts by mass of DMAEMA are dissolved in 150 parts by mass of EtOAc, and dimethyl-2,2-azobis (2-methylpropionate) (trade name V-601, Wako Pure Chemical Industries, Ltd.) as a polymerization initiator After adding 0.6 parts by mass of Osaka Co., Ltd., Osaka, Japan, the mixture is reacted at 65 ° C. for 24 hours under a nitrogen atmosphere, and an EtOAc solution (solid content of amino group-containing (meth) acrylic polymer 1 (HAP1) 40% was prepared. The weight average molecular weight (Mw) of HAP1 was 68,000, and the glass transition temperature (Tg) was 63.degree. The Tg was determined from the formula of FOX (the following formula), assuming that each polymer was copolymerized from n types of monomers.

<Production of Adhesive Polymer 1 (ADH 1)>
76 parts by mass of BA, 21 parts by mass of 2EHA, 2 parts of VAc, and 1 part by mass of AA are dissolved in 203 parts by mass of a mixed solvent of toluene / EtOAc (mass ratio 50:50), and 2,2′-azobis (2,2, After adding 0.2 parts by mass of 4-dimethylvaleronitrile (trade name V-65, Wako Pure Chemical Industries, Osaka, Japan), react for 24 hours at 65 ° C. in a nitrogen atmosphere to make it sticky A solution of Polymer 1 (ADH1) in toluene / EtOAc (33% solids) was prepared. The weight average molecular weight (Mw) of ADH1 was 660,000, and the glass transition temperature (Tg) was -57 ° C.

<Production of Adhesive Polymer 2 (ADH 2)>
94 parts by mass of 2EHA, 2 parts by mass of MA, and 4 parts by mass of AA are dissolved in 122 parts by mass of a mixed solvent of toluene / EtOAc (mass ratio 50: 50), and 2,2′-azobis (2,4-dimethylazo) as a polymerization initiator After adding 0.2 parts by mass of valeronitrile (trade name V-65, manufactured by Wako Pure Chemical Industries, Ltd.), the mixture is reacted at 65 ° C. for 24 hours under a nitrogen atmosphere to obtain toluene / EtOAc of adhesive polymer 2 (ADH 2) A solution (45% solids) was prepared. The weight average molecular weight (Mw) of ADH2 was 640,000, and the glass transition temperature (Tg) was -62 ° C.

<Production of Adhesive Polymer 3 (ADH 3)>
94 parts by mass of BA and 6 parts by mass of AA are dissolved in 203 parts by mass of a mixed solvent of toluene / EtOAc (mass ratio 50: 50), and 2,2′-azobis (2,4-dimethylvaleronitrile) (polymerization initiator) After adding 0.2 parts by mass of trade name V-65, manufactured by Wako Pure Chemical Industries, Ltd., the mixture is reacted at 65 ° C. for 24 hours under a nitrogen atmosphere, and a toluene / EtOAc solution (solid content) of adhesive polymer 3 (ADH3) 33% was prepared. The weight average molecular weight (Mw) of ADH3 was 760,000, and the glass transition temperature (Tg) was -48 ° C.

  The materials used to make the graphic film in this example are shown in Table 2.

<Example 1>
The pigment 1, the amino group-containing (meth) acrylic polymer 1 (HAP1), and MIBK were mixed to prepare a white pigment dispersion solution. The mass ratio of pigment 1 to HAP1 was 5: 1 in solid content. The solid content of the white pigment dispersion was about 66%. A white adhesive solution was prepared by mixing a white pigment dispersion solution, a tacky polymer 1 (ADH1), a tackifier 1 (TF1) and a crosslinking agent 1 (CL1). Regarding the amount of each component used, 73.5 parts by mass of ADH1, 2 parts by mass of HAP1, 24.5 parts by mass of TF1, 10 parts by mass of pigment 1, and 0.10 parts by mass of CL1. That is, the pigment 1 was 10 parts by mass (pigment 1 / (ADH1 + HAP1 + TF1) × 100 = 10) and CL1 was 0.10 parts by mass with respect to a total of 100 parts by mass of ADH1, HAP1 and TF1.

  The white adhesive solution was coated on a silicone treated 50 μm thick polyester film using a knife coater. The applied layer was dried at 95 ° C. for 5 minutes to obtain a 30 μm thick white pressure-sensitive adhesive layer.

  After laminating the base film layer and the pressure-sensitive adhesive layer, the backing film was peeled off to obtain the graphic film of Example 1. Table 3 shows the details of the film layer and the pressure sensitive adhesive layer.

<Examples 2 to 27 and Comparative Examples 1 to 5>
Graphic films of Examples 2 to 27 and Comparative Examples 1 to 5 were produced in the same manner as in Example 1 except that the thickness of the film layer and the composition of the pressure-sensitive adhesive layer were as shown in Table 3.

<Comparative Examples 6 to 7>
A commercially available graphic film (Comparative Example 6: polyvinyl chloride cast film layer / gray pressure sensitive adhesive layer, Comparative Example 7: polyvinyl chloride calendar film layer / gray pressure sensitive adhesive layer) was obtained for evaluation. Details are shown in Table 3.

  The evaluation results of the graphic films of Examples 1 to 27 and Comparative Examples 1 to 7 are shown in Table 4.

Examples 28 to 35, Comparative Examples 8 to 10
In Examples 28 to 35 and Comparative Examples 8 to 10, a 50 μm-thick transparent acrylic film with a 50 μm-thick release-treated polyester film, which is commercially available, was used as a base film layer. A graphic film was produced in the same manner as in Example 1 except that the composition of the pressure-sensitive adhesive layer was as shown in Table 5. In addition, in Example 30, in addition to the pigment 1, another aluminum paste made by Toyo Aluminum Co., Ltd., aluminum paste 0215M (pigment 2) was added. The addition amount of pigment 2 was 0.5 parts by mass with respect to a total of 100 parts by mass of ADH1, HAP1, TF1 and pigment 1 in terms of solid content. The adhesion of these graphic films is shown in Table 5 together.

It will be apparent to those skilled in the art that various changes can be made to the embodiments and examples described above without departing from the basic principles of the invention. It will also be apparent to those skilled in the art that various modifications and alterations of the present invention can be implemented without departing from the spirit and scope of the present invention. Some of the embodiments of the present invention are described in the following items [1] to [14].
[1]
A graphic film for a license plate, comprising: a base film layer having an upper surface and a lower surface; and a pressure sensitive adhesive layer disposed on the lower surface of the base film layer, wherein the pressure sensitive adhesive layer is
(A) Carboxyl group-containing tacky (meth) acrylic polymer having a glass transition temperature of −50 ° C. or less,
(B) A dispersant comprising an amino group-containing (meth) acrylic polymer free of monomer units derived from an aromatic vinyl monomer,
(C) At least one adhesive selected from the group consisting of rosin ester type, hydrogenated rosin type, terpene phenol type, styrene type, hydrogenated terpene phenol type, aromatic modified hydrogenated terpene resin, and aromatic modified terpene resin A imparting agent,
(D) A total of 100 parts by mass of the above-mentioned carboxyl group-containing tacky (meth) acrylic polymer, dispersant containing an amino group-containing (meth) acrylic polymer not containing a monomer unit derived from an aromatic vinyl monomer, and tackifier And 10 parts by weight or more of a white pigment
Graphic films, including.
[2]
The graphic film according to [1], wherein the base film layer is a polyvinyl chloride film having a thickness of 60 μm or more.
[3]
The graphic film according to any one of [1] or [2], wherein the base film layer is a cast film.
[4]
The graphic film according to any one of [1] to [3], wherein the base film layer is colored white.
[5]
At least one of the carboxyl group-containing tacky (meth) acrylic polymer and the amino group-containing (meth) acrylic polymer not containing a monomer unit derived from the aromatic vinyl monomer is crosslinked [1] to [1] 4) The graphic film as described in any one of 4).
[6]
The graphic film according to [5], wherein the crosslinking is formed using at least one of a bisamide crosslinking agent and an epoxy crosslinking agent.
[7]
The graphic film according to any one of [1] to [6], wherein the tackifier is a rosin ester.
[8]
The graphic film according to any one of [1] to [7], further comprising a print layer disposed on the upper surface of the base film layer.
[9]
The graphic film of [8], further comprising a surface protection layer disposed on the print layer.
[10]
The surface protective layer contains a reaction product of at least a polyester skeleton or a polyol having either a polycarbonate skeleton or a trifunctional or higher aliphatic isocyanate, and the glass transition temperature Tg of the surface protective layer is 50 ° C. or higher, The graphic film of [9], which has a loss tangent tan δ at 120 ° C. of not more than 0.1.
[11]
The graphic film according to [10], wherein the aliphatic isocyanate contains an isocyanurate of isophorone diisocyanate, an adduct, or both of them.
[12]
It has a colored layer between the above-mentioned base film layer and the above-mentioned surface protection layer, and the above-mentioned colored layer is formed from a thermoplastic ink composition containing a copolymer resin containing at least vinyl chloride units and vinyl acetate units It is, The graphic film as described in any one of [9]-[11].
[13]
A license plate comprising a base plate and the graphic film according to any one of [1] to [12] laminated on the base plate.
[14]
Providing a base plate;
Laminating the graphic film according to any one of [1] to [8] on the base plate to form a laminated plate;
Embossing or debossing the laminate plate;
Forming a colored layer on the projections or recesses of the embossed or debossed laminated plate;
Forming a surface protection layer to cover the graphic film and the colored layer;
A method of manufacturing a license plate, including:

10 Graphic Film 12 Base Film Layer 14 Pressure-Sensitive Adhesive Layer 16 Printing Layer 17 Bonding Layer 18 Surface Protective Layer 19 Liner 20 License Plate 22 Base Plate 24 Colored Layer 26 Surface Protective Layer 30 Blank Press Die

Claims (10)

A graphic film for a license plate, comprising: a base film layer having an upper surface and a lower surface; and a pressure sensitive adhesive layer disposed on the lower surface of the base film layer, wherein the pressure sensitive adhesive layer is
(A) Carboxyl group-containing tacky (meth) acrylic polymer having a glass transition temperature of −50 ° C. or less,
(B) A dispersant comprising an amino group-containing (meth) acrylic polymer free of monomer units derived from an aromatic vinyl monomer,
(C) At least one adhesive selected from the group consisting of rosin ester type, hydrogenated rosin type, terpene phenol type, styrene type, hydrogenated terpene phenol type, aromatic modified hydrogenated terpene resin, and aromatic modified terpene resin A imparting agent,
(D) A total of 100 parts by mass of the above-mentioned carboxyl group-containing tacky (meth) acrylic polymer, dispersant containing an amino group-containing (meth) acrylic polymer not containing a monomer unit derived from an aromatic vinyl monomer, and tackifier Graphic film containing 10 parts by weight or more of a white pigment.   The graphic film according to claim 1, wherein the base film layer is a polyvinyl chloride film having a thickness of 60 μm or more.   The graphic film according to any one of claims 1 or 2, wherein the base film layer is a cast film.   The graphic film according to any one of claims 1 to 3, wherein the base film layer is colored white.   5. The carboxyl group-containing tacky (meth) acrylic polymer and at least one of an amino group-containing (meth) acrylic polymer not containing a monomer unit derived from the aromatic vinyl monomer are crosslinked. Graphic film according to any one of the preceding claims.   The graphic film according to claim 5, wherein the crosslinking is formed using at least one of a bisamide crosslinking agent and an epoxy crosslinking agent.   The graphic film according to any one of claims 1 to 6, wherein the tackifier is a rosin ester.   The graphic film according to any one of claims 1 to 7, further comprising a print layer disposed on top of the base film layer.   The graphic film of claim 8, further comprising a surface protection layer disposed on the print layer.   The surface protective layer contains a reaction product of at least a polyester skeleton or a polyol having either a polycarbonate skeleton or a trifunctional or higher aliphatic isocyanate, and the glass transition temperature Tg of the surface protective layer is 50 ° C. or higher, The graphic film according to claim 9, wherein the loss tangent tan δ at 120 ° C is 0.1 or less.

Images