JP5350731B2 - Transfer sheet having metal thin film on part of sheet surface and having acrylic anchor layer, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer sheet in which no small bubble is produced at a boundary line between a part of a transfer layer where no metal thin film is produced and the metal thin film even when the metal thin film is formed at a part of a sheet surface of the transfer layer and small bubble suppressing effect is maintained for a long period of time even under high humidity environment. <P>SOLUTION: There is disclosed the transfer sheet with the transfer layer having at least a front anchor layer, the metal thin film and a rear anchor layer, formed on one side of a base sheet. The metal thin film is formed at a part of the sheet surface of the transfer layer and the rear anchor layer comprises an acrylic resin or an acrylic urethane resin which is more flexible than a melamine resin. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a transfer sheet used for transferring a resin layer or a design layer laminated on one side of a base sheet to the surface of an article, and more particularly to a transfer sheet having a metal thin film as a design layer.

  A method of protecting or decorating the surface of an article such as a plastic part or an exterior part using a transfer sheet is conventionally known. The transfer sheet has a structure in which a transfer layer is provided on one side of a base sheet as a support, and this transfer layer is transferred from the base sheet to the surface of the article. The transfer layer transferred to the surface of the article is a laminate in which resins and designs are laminated in layers, and forms a protective coating and a decorative coating on the article surface.

  Conventionally, a transfer sheet having a metal thin film has been used to impart a metallic luster appearance to the surface of an article as a kind of decoration.

  For example, Patent Document 1 describes a transfer sheet having both metallic luster and insulation, using a layer in which tin or indium is deposited so as to have a fine island structure. The metal thin film can achieve a metallic luster with such a small amount of metal, but has a problem that the deposited metal is thin and the deposited metal is easily deteriorated.

  For example, when a layer adjacent to the metal thin film (referred to herein as an “anchor layer”) contains a corrosive substance such as an acid, the deposited metal is easily corroded and loses its metallic luster. Therefore, the decorative function of the transfer sheet is reduced in a short period, and the metallic luster of the article decorated with the transfer sheet is also deteriorated in a short period. In order to solve the problem that the metal thin film corrodes due to the influence of the adhesive layer adjacent to the metal thin film, in the transfer sheet of Patent Document 1, a corrosion-resistant resin layer containing a melamine resin is formed adjacent to the metal thin film. .

  However, the melamine-based resin is thermosetting, has a high curing temperature, and needs to be heated at a high temperature to form a layer, so that the manufacturing operation is complicated. In addition, the resin has high hardness and is difficult to adapt to other resin layers. Furthermore, since the degree of shrinkage during curing is large, defects such as wrinkles and poor adhesion are likely to occur.

  In the transfer sheet of Patent Document 1, the metal thin film is formed on the entire sheet surface of the transfer layer, but may be formed on a part. The sheet surface here means a plane parallel to the main surface of the transfer layer, that is, any plane parallel to the main surface of the base sheet. The transfer layer in which the metal thin film is formed on a part of the sheet surface can make the portion where the metal thin film is not formed transparent, and is useful for, for example, an application in which the periphery of the display panel is decorated with a metal color. The transfer layer for such applications is required to have sufficient transparency to ensure the visibility of the display portion and the ability to maintain the transparency over time.

  Examples of a method for forming a metal thin film as a pattern on a part of the sheet surface include a water removal method and an alkali removal method. The operation of patterning the metal thin film using the water removal method is specifically described in Patent Documents 2 and 3 and the like.

  The water removal method means that a water-soluble resin layer is first formed partially on the surface of the resin layer that supports the metal thin film, and then a metal thin film is formed on the entire surface, and then washed with water to thereby wash the water-soluble resin layer In this method, an unnecessary metal thin film portion formed in (1) is removed and a metal thin film is partially formed. Examples of methods for forming the water-soluble resin layer include printing methods such as gravure printing, flexographic printing, and screen printing. In that case, as a material for forming the water-soluble resin layer, for example, a water-based resin ink using a water-soluble resin typified by polyvinyl alcohol, starch, alginide, epoxy, polyurethane, etc. as a binder and silica or the like as a pigment is used. .

  Alkali removal method means that after forming a metal thin film on the surface of the resin layer supporting the metal thin film, an alkali resistant resin layer is partially formed on the metal thin film, and then the alkali resistance of the metal thin film is obtained by alkali cleaning. This is a method of selectively removing a portion not covered with a resin layer. Examples of the method for forming the alkali-resistant resin layer include coating methods such as gravure coating, roll coating, and comma coating, printing methods such as gravure printing, and screen printing. In that case, as a material for forming the alkali-resistant resin layer, a paint or ink containing an alkali-resistant resin such as vinyl chloride-vinyl acetate copolymer is used.

  However, when a metal thin film is formed on a part of the sheet surface in this way, it is clear that small bubbles (bubble defects) are likely to occur at a portion where the metal thin film is not formed, particularly at the boundary with the metal thin film. Became. In addition, such a small bubble is a case where the metal thin film formed on a part of the sheet surface is a layer in which tin or indium is deposited so as to have a fine island structure, or when placed in a high humidity environment It was also found that this is particularly likely to occur.

Such small bubbles obstruct the decorative function of the transfer layer, lower the transparency of the transfer layer, and cause problems such as difficulty in recognizing information displayed on the display. The cause of the generation of small bubbles is not clear. However, if a metal thin film is formed on a part of the sheet surface, a step is formed between the metal thin film and the support layer at the end of the metal thin film, so an air layer may be formed between the resin layer formed on the metal layer. It is done. In addition, the surface of the support layer of the metal thin film is somewhat roughened by the action of water-based resin ink or alkali used for patterning the metal thin film, or by rubbing with a brush or the like when cleaning and removing a part of the metal thin film. In addition, it is conceivable that an air layer is formed between the resin layer formed thereon. Furthermore, it is conceivable that the water-based resin ink or alkali remains to some extent and the adhesion with the resin layer formed thereon is inhibited.
JP2007-326300 Patent No. 4096023 Japanese Patent Laid-Open No. 3-26540

  The present invention solves the above-described conventional problems. The object of the present invention is to form the transfer layer metal thin film even when the metal thin film is formed on a part of the sheet surface of the transfer layer. It is an object of the present invention to provide a transfer sheet in which small bubbles are not generated at the boundary between the unexposed portion and the metal thin film, and the effect of suppressing small bubbles is maintained for a long time even in a high humidity environment.

The present invention is a transfer sheet in which a transfer layer having at least a front anchor layer, a metal thin film and a rear anchor layer is formed on one side of a base sheet,
The front anchor layer is composed of at least one resin selected from the group consisting of a two-component curable acrylic urethane resin, a two-component curable polyester urethane resin, a nitrocellulose resin, and a melamine resin,
The metal thin film is an insulating metal thin film made of tin or indium formed on a part of the sheet surface of the transfer layer ,
Provided is a transfer sheet in which the rear anchor layer comprises an acrylic resin or an acrylic urethane resin having a glass transition temperature of 40 to 120 ° C., a hydroxyl value of 10 to 200, and a number average molecular weight of 7,000 to 15,000. Thus, the above object is achieved.

The present invention also includes a step of forming a front anchor layer as a layer constituting the transfer layer on one side of the base sheet;
Forming a metal thin film on a portion of the surface of the front anchor layer;
Forming a rear anchor layer on the entire surface thereof;
A transfer sheet manufacturing method comprising:
The front anchor layer is composed of at least one resin selected from the group consisting of a two-component curable acrylic urethane resin, a two-component curable polyester urethane resin, a nitrocellulose resin, and a melamine resin,
The metal thin film is an insulating metal thin film made of tin or indium;
A method for producing a transfer sheet, wherein the rear anchor layer comprises an acrylic resin or an acrylic urethane resin having a glass transition temperature of 40 to 120 ° C., a hydroxyl value of 10 to 200, and a number average molecular weight of 7,000 to 15,000. provide.

Furthermore, the present invention includes a step of forming a front anchor layer as a layer constituting the transfer layer on one side of the base sheet;
Forming a water-soluble resin layer on a part of the surface of the front anchor layer;
Forming a metal thin film on the entire surface;
Removing the water-soluble resin layer and the metal thin film formed thereon by washing with water;
Forming a rear anchor layer on the entire surface thereof;
A transfer sheet manufacturing method comprising:
The front anchor layer is composed of at least one resin selected from the group consisting of a two-component curable acrylic urethane resin, a two-component curable polyester urethane resin, a nitrocellulose resin, and a melamine resin,
The metal thin film is an insulating metal thin film made of tin or indium;
A method for producing a transfer sheet, wherein the rear anchor layer comprises an acrylic resin or an acrylic urethane resin having a glass transition temperature of 40 to 120 ° C., a hydroxyl value of 10 to 200, and a number average molecular weight of 7,000 to 15,000. provide.

  In the transfer layer of the transfer sheet of the present invention, a metal thin film is formed on a part of the sheet surface of the transfer layer, but small bubbles are generated at the boundary between the metal thin film and the portion where the metal thin film is not formed. The transparency of the transfer layer is excellent. Moreover, the small bubble suppression effect and transparency are maintained for a long time even in a high humidity environment.

Transfer Sheet FIG. 1 is a sectional view showing the structure of a transfer sheet according to an embodiment of the present invention. A transfer layer 2 is provided in contact with one surface of the base sheet 1. The transfer layer 2 includes a hard coat layer 3, a front anchor layer 4, a metal thin film 5, a rear anchor layer 6, and an adhesive layer 7 that are sequentially laminated from the base sheet side.

  Of the layers constituting the transfer layer, each resin layer can be formed by the same method as before unless otherwise specified. Examples of conventional layer forming methods include coating methods such as gravure coating, roll coating, and comma coating, printing methods such as gravure printing, and screen printing.

Base sheet Base sheet 1 is composed of a sheet material or a film material conventionally used for supporting a design layer or a hard coat layer on a sheet. Film material refers to a sheet material made of synthetic resin. As the synthetic resin, polypropylene resin, polyethylene resin, polyamide resin, polyester resin, acrylic resin, polyvinyl chloride resin and the like can be used. In addition, a metal sheet such as aluminum foil or copper foil, a cellulose sheet such as glassine paper, coated paper, cellophane, or a composite of each of the above-mentioned sheets having releasability as a base sheet of a normal transfer sheet It can be used as a base sheet.

The transfer layer transfer layer 2 is a layer provided on one side of the base sheet and transferred from the base sheet to the surface of the object to be decorated. The transfer layer has at least a front anchor layer 4, a metal thin film 5, and a rear anchor layer 6 that are stacked in order from the base sheet side. Further, if necessary, the transfer layer is provided between the base sheet 1 and the front anchor layer 4, adjacent to the exposed surface of the hard coat layer 3, the design layer (not shown), and the rear anchor layer 6. A layer (not shown) or an adhesive layer 7 may be included.

  The front anchor layer 4 is a resin layer that adheres the metal foil film 5 to the transfer layer. The front anchor layer is formed on the entire sheet surface, and after the transfer layer is transferred to the article, it also serves to protect the metal thin film 5 from scratches and the like together with the hard coat layer and improve the corrosion resistance.

  The resin used for the front anchor layer includes two-component cured urethane resin, thermosetting urethane resin, melamine resin, cellulose ester resin, chlorine-containing rubber resin, chlorine-containing vinyl resin, acrylic resin, epoxy resin And vinyl copolymer resins. For applications that require metallic color durability, a resin containing no halogen such as chlorine is preferred. This is because the halogen-containing resin may corrode the metal thin film in a high humidity environment.

  Moreover, when forming the metal thin film 5 in a part of sheet | seat surface as FIG. 1 shows, it is preferable to use comparatively hard resin as a front anchor layer. For example, it is preferable to use a thermosetting resin that forms a crosslinked structure. This is because the surface of the front anchor layer is less likely to be rough even if it is rubbed with a brush or the like when water-based resin ink or alkali used for patterning the metal thin film acts or when a part of the metal thin film is washed away. is there. As a result, water-based resin ink, alkali, and the like are hardly left on the surface. In that case, preferred resins for the front anchor layer include urethane resins such as acrylic urethane, polyester urethane, and epoxy urethane, particularly curable urethane resins such as two-component cured urethane resins and thermosetting urethane resins, melamine resins, and the like. Such as nitrocellulose-based resin. The front anchor layer can be formed by applying and drying a paint containing such a resin, or by heating and curing after application.

  The metal thin film 5 is a metal layer that gives the transfer layer a metallic luster appearance. The metal thin film may be formed on the entire sheet surface of the transfer layer or a part thereof. As shown in FIG. 1, when the metal thin film 5 is formed on a part of the sheet surface, it is preferable to use the water removal method or the alkali removal method described above. The metal used for the metal thin film may be an alloy, compound, or the like of aluminum, nickel, gold, platinum, chromium, iron, copper, tin, indium, silver, titanium, lead, zinc, etc. is there.

  In one certain form, a metal thin film combines the metallic luster and insulation which are described in patent document 1 etc., radio wave permeability, and the use characteristic adjacent to an electrostatic switch. The insulating metal thin film preferably has an island structure with an island size of 1 nm to 2 μm and an island interval of 2 nm to 500 nm. As the metal used for the insulating metal thin film, one selected from the group consisting of tin, indium, lead, zinc, bismuth, titanium, chromium, iron, cobalt, nickel, silicon, germanium, or an alloy thereof can be used. In particular, tin or indium is preferable from the viewpoint of insulation.

  The metal thin film can be formed by a method similar to the conventional method. Specific examples of the forming method include a vacuum deposition method, a sputtering method, an ion plating method, and a plating method.

  The rear anchor layer 6 is a resin layer that adheres the metal foil film 5 to an adhesive layer or an object to be decorated. The rear anchor layer is formed on the entire sheet surface, and also serves to protect the metal thin film 5 from corrosion components contained in the adhesive layer and the object to be decorated and to improve the corrosion resistance.

  Examples of the resin used for the rear anchor layer include the same resin as the front anchor layer, but a more flexible resin is preferable. For example, it is preferable to use a thermoplastic resin. This is because the flexible resin is easily filled up to the end of the metal thin film generated by forming the metal thin film on a part of the sheet surface, that is, the level difference from the surface of the front anchor layer, and an air layer is hardly generated.

  For example, the melamine resin described in Patent Document 1 is known as a relatively hard resin, and it is difficult for the melamine resin to enter the level difference between the metal anchor edge and the surface of the front anchor layer, and an air layer is formed. Therefore, small bubbles are easily generated. Therefore, a resin that is more flexible than at least the melamine resin (cured state) is preferable.

  For example, a thermoplastic resin having a glass transition temperature of −30 to 120 ° C., preferably 20 to 300 ° C., more preferably 40 to 150 ° C. is sufficiently flexible in a normal temperature environment, and the transparent portion of the transfer layer and the metal thin film Small bubbles are unlikely to occur at the borders. The type of resin is preferably an acrylic resin or an acrylic urethane resin. This is because they are excellent in flexibility, have excellent adhesion to the preferred front anchor layer, and do not easily generate small bubbles. The glass transition temperature also affects the printability. When the resin has a low glass transition temperature of less than −30 ° C., it is difficult to adjust the viscosity and printability is deteriorated.

  The glass transition temperature (Tg) in the present specification refers to the midpoint glass transition temperature (° C.) obtained by heat flux DSC under the temperature rising condition at a heating rate of 10 ° C./min according to JIS K7121 (1987). For adjusting the state of the test piece, “when measuring the glass transition temperature after performing a certain heat treatment” shall be adopted. The device used is a differential scanning calorimeter (DSC6200, manufactured by Seiko).

  An acrylic resin here means the (co) polymer prepared using (meth) acrylic acid and / or (meth) acrylic acid ester as a monomer. The acrylic resin can be obtained by polymerizing a monomer having an ethylenically unsaturated double bond in one molecule in a solvent using a polymerization initiator.

  Here, the monomer having an ethylenically unsaturated double bond in one molecule is (i) (meth) acrylic acid derivative, (ii) aromatic vinyl monomer, (iii) olefinic hydrocarbon monomer Body, (iv) vinyl ester monomer, (v) vinyl halide monomer, (vi) vinyl ether monomer, and the like.

(I) Examples of (meth) acrylic acid derivatives include (meth) acrylonitrile, (meth) acrylate, methyl (meth) acrylate, butyl (meth) acrylate, ethylhexyl (meth) acrylate, stearyl (meth) acrylate, etc. Examples include alkyl (meth) acrylate and benzyl (meth) acrylate.
(Ii) Examples of aromatic vinyl monomers include styrene, methyl styrene, ethyl styrene, chloro styrene, monofluoromethyl styrene, difluoromethyl styrene, trifluoromethyl styrene and the like in which some hydrogen is fluorine-substituted. Etc.
(Iii) Examples of olefinic hydrocarbon monomers include ethylene, propylene, butadiene, isobutylene, isoprene, 1,4-pentadiene, and the like.
(Iv) Examples of vinyl ester monomers include vinyl acetate.
(V) Examples of the vinyl halide monomer include vinyl chloride and vinylidene chloride.
(Vi) Examples of vinyl ether monomers include vinyl methyl ether.

Moreover, the monomer which has an ethylenically unsaturated double bond in 1 molecule can use the monomer which has a crosslinkable functional group. Examples of the monomer having a functional group include (vii) a monomer having a hydroxyl group, (viii) a monomer having an isocyano group, and (ix) a monomer having an epoxy group.
(Vii) Examples of monomers having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. , Polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polytetramethylene glycol mono (meth) acrylate, hydroxystyrene and the like.
(Viii) Examples of monomers having an isocyano group include (meth) acryloyloxyethyl isocyanate, (meth) acryloyloxypropyl isocyanate, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) Examples thereof include those obtained by reacting a hydroxyalkyl (meth) acrylate such as acrylate with a polyisocyanate such as toluene diisocyanate and isophorone diisocyanate.
(Ix) Examples of the monomer having an epoxy group include glycidyl methacrylate, glycidyl cinnamate, glycidyl allyl ether, glycidyl vinyl ether, vinylcyclohexane monoepoxide, 1,3-butadiene monoepoxide, and the like.

  Depending on the required performance, a monomer having an ethylenically unsaturated double bond in one molecule can be used alone, or a mixture of two or more can be used.

  The acrylic urethane resin is obtained by modifying an acrylic resin with a urethane component, and can be produced by chemically bonding the urethane resin and the acrylic resin component.

  Specific examples of the chemical bonding method include (1) a polymer obtained by introducing a hydroxyl group into an acrylic polymer obtained using β-hydroxyethyl (meth) acrylate and a urethane having an isocyanate group at the molecular end. A method of reacting with a prepolymer, (2) a method of reacting an acrylic component having a hydroxyl group at the molecular end (one or both ends) with a urethane prepolymer having an isocyanate group at the molecular end, and (3) an acrylic diol mixed system And (4) a method of polymerizing a urethane acrylate after adding a terminal polyester or polyether at both ends or a polyether to an acrylic monomer, and the like.

  In the acrylic urethane resin obtained by such a method, the urethane chain and the acrylic chain may be bonded to each other in a block type or in a graft type. As the acrylic resin component used for these synthesis, β-hydroxyethyl (meth) acrylate, β-hydroxypropyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, isobutyl (meth) acrylate, n- (Meth) acrylic acid esters such as butyl (meth) acrylate and glycidyl (meth) acrylate; those obtained by copolymerizing polymerizable monomers such as acrylonitrile, acrylamide, styrene, vinyl acetate, vinyl chloride, maleic acid, and derivatives thereof Can be mentioned. These acrylic urethane resins may be used alone or in combination of two or more.

  The number average molecular weight of the acrylic resin or acrylic urethane resin is preferably 5,000 to 50,000, particularly preferably 7,000 to 15,000. If the number average molecular weight is less than 5000, there is a problem that moisture penetrates through a slight gap generated between the molecules because the molecules are small and promotes corrosion. When the number average molecular weight exceeds 15,000, the flexibility is lowered, and when the molecular weight is further increased, the solubility in a solvent is deteriorated, leading to a decrease in printability.

  More preferably, the acrylic resin or acrylic urethane resin used for the rear anchor layer has moderate hydrophilicity. Specifically, this resin has a hydroxyl value of 5 to 300, preferably 10 to 250, more preferably 10 to 200. The hydroxyl value here means a value measured by the method described in JISK0070.

  Such a resin has excellent adhesion to a metal thin film, and even if the surface of the front anchor layer is somewhat rough due to the action of water-based resin ink or alkali used when designing the metal thin film, This is because even if resin ink or alkali remains to some extent, familiarity with the surface of the front anchor layer is not hindered and small bubbles are hardly generated. If the hydroxyl value is low, the adhesion with the front anchor layer is lowered, and small bubble bubbles are generated after the moisture resistance test. On the other hand, if the hydroxyl value is high, the dissolving power for a solvent used in a general gravure ink is lowered, and the printability is deteriorated.

  In particular, in applications where metal color durability is required, a resin containing no halogen such as chlorine is preferred. This is because the halogen-containing resin may corrode the metal thin film in a high humidity environment. Insulating metal thin films, especially tin or indium thin films, have poor metal color durability compared to aluminum thin films, etc., and at least the rear anchor layer, preferably the front anchor layer and the rear anchor layer, use a resin that does not contain halogen. It is preferable. The method for forming the rear anchor layer is the same as the conventional method.

  The hard coat layer 3 is a resin layer formed between the base sheet and the front anchor layer as necessary. The hard coat layer is disposed on the surface of the decorative object when the substrate sheet is peeled off from the object to be decorated after the transfer, and has a certain hardness or more to protect the transfer layer. Examples of the material of the hard coat layer include ionizing radiation curable resins such as cyanoacrylate and urethane acrylate, and thermosetting resins such as acrylic and urethane, but are not particularly limited.

  The adhesive layer 7 is provided on the surface closest to the object to be decorated of the transfer layer as necessary. The adhesive layer adheres the transfer layer and the object to be decorated at the time of transfer. As the adhesive layer, a heat-sensitive or pressure-sensitive resin suitable for an object to be decorated is appropriately used. For example, when the material of the object to be decorated is an acrylic resin, an acrylic resin may be used.

  In addition, when the material of the decoration object is polyphenylene oxide / polystyrene resin, polycarbonate resin, styrene copolymer resin, or polystyrene blend resin, acrylic resin, polystyrene resin, polyamide having affinity with these resins A series resin or the like may be used. Furthermore, when the material of the decoration object is polypropylene resin, chlorinated polyolefin resin, chlorinated ethylene-vinyl acetate copolymer resin, cyclized rubber, and coumarone indene resin can be used.

  A release layer may be further formed between the base sheet and the transfer layer. The release layer may be separated from the transfer layer together with the base sheet during transfer, or may be separated from the base sheet to form the outermost surface of the transfer layer. As the material of the release layer, melamine resin, silicone resin, fluorine resin, cellulose derivative, urea resin, polyolefin resin, paraffin resin, and composites thereof can be used.

  In addition, a design layer may be added to the transfer layer. In that case, if the design layer is formed on the object side from the hard coat layer, for example, between the hard coat layer and the front anchor layer, the added design is sufficient. Protected.

  As the material of the pattern layer, a resin such as polyvinyl resin, polyamide resin, polyacrylic resin, polyurethane resin, polyvinyl acetal resin, polyester urethane resin, cellulose ester resin, alkyd resin, etc. is used as a binder. Colored inks containing color pigments or dyes as colorants may be used. In the case of forming a metal color, a pearl pigment in which titanium oxide is coated on metal particles such as aluminum, titanium, bronze, or mica can be used.

  As a pattern layer forming method, a normal printing method such as an offset printing method, a gravure printing method, or a screen printing method may be used. In particular, the offset printing method and the gravure printing method are suitable for performing multicolor printing and gradation expression. In the case of a single color, a coating method such as a gravure coating method, a roll coating method, or a comma coating method may be employed.

Production method of transfer sheet The transfer sheet of the present invention is formed by forming a metal thin film on a part of the sheet surface of the transfer layer and using a resin that is more flexible than the melamine resin as described above as a rear anchor layer. Is manufactured in the same manner as a conventional transfer sheet.

  FIG. 2 is a process diagram showing an example of the transfer sheet manufacturing method of the present invention.

  For example, a base sheet is prepared, and layers constituting the transfer layer are sequentially formed on one side thereof. As described above, the layer constituting the transfer layer includes a hard coat layer, a design layer, a front anchor layer, a metal thin film, a rear anchor layer, an additional anchor layer, and an adhesive layer. If necessary, a release layer is formed on the surface of the base sheet that is in contact with the transfer layer.

  When forming a metal thin film as a pattern on a part of the sheet surface, for example, as shown in FIG. 2 (a), a hard coat layer 3 and a front anchor layer 4 are formed on one side of the base sheet 1 as a transfer layer. A metal thin film pattern is formed on the substrate. As a method for forming the pattern of the metal thin film, a water removal method or an alkali removal method may be used, but a water removal method is usually used.

  In the water removal method, for example, as shown in FIG. 2B, gravure printing is performed using a water-based resin ink using a water-soluble resin such as polyvinyl alcohol as a binder and silica as a pigment, and the front anchor layer 4 A water-soluble resin layer 8 is formed on a part of the surface of the substrate. Next, as shown in FIG. 2C, a metal foil film 5 is formed by vapor-depositing a metal on the entire surface.

  If necessary, a metal thin film protective layer (not shown) is formed on the metal thin film. The protective layer is preferably formed using a thermoplastic resin, in addition to polyester resins, polyurethane resins, acrylic resins, polyvinyl chloride resins, cellulose resins, rubber resins, polyvinyl acetate resins, Copolymers such as vinyl chloride-vinyl acetate copolymer resin and ethylene-vinyl acetate copolymer resin may be used.

  In order to improve the adhesion between the metal thin film and the protective layer, the sheet material may be heated after the protective layer is formed. In that case, the heating conditions are preferably such that the peak temperature on the surface of the sheet material is 120 to 170 ° C. and the heating time is 20 to 50 seconds. Furthermore, it is particularly preferable that the peak temperature on the surface of the sheet material is 140 ° C. to 150 ° C. and the heating time is 30 to 40 seconds. Then, the adhesion between the water-soluble resin layer, the metal thin film, and the protective layer is increased, and when the water-soluble resin layer is removed by a subsequent water washing treatment, the shape of the water-soluble resin layer is formed. The water-soluble resin layer, the metal thin film, and the protective layer are removed cleanly along the contour.

  Next, a water washing treatment is performed, and the water-soluble resin layer 8, the metal thin film formed thereon and the protective layer present optionally are peeled off as shown in FIG. 2 (d). In order to perform the water washing treatment, the sheet material on which the water-soluble resin layer and the metal thin film are formed is immersed in cold water or a hot water tank, or the surface on which the metal thin film is formed is softly brushed while performing cold water or hot water shower water discharge. Friction cleaning is performed with Next, water adhering to the sheet is removed by hot air drying.

  When cleaning and removing a part of the metal thin film, if the cleaning is too strong, the remaining metal thin film may be damaged and the design may be disturbed. In particular, a layer in which a metal thin film is deposited so that tin or indium has a fine island structure is easily damaged, and cannot be strongly cleaned using a brush or the like. Therefore, in this case, removal of the aqueous resin or the like tends to be incomplete.

  Small bubbles on the sheet surface where the metal thin film is not formed often occur when the metal thin film is a layer deposited with tin or indium to form a fine island structure. Resin is considered to be one of the causes of small bubbles.

  Thereafter, as shown in FIG. 2E, the rear anchor layer 6 is formed on the entire surface of the formed metal thin film pattern, and other layers constituting the transfer layer such as the adhesive layer 7 are formed. Thus, the transfer sheet of the present invention in which the transfer layer 2 is formed on one surface of the base sheet 1 is obtained.

Article decoration method Articles can be decorated by hot roll transfer or in-mold molding using the transfer sheet of the present invention. For example, in thermal roll transfer, the surface of the transfer sheet on the adhesive layer side (opposite side of the base sheet) is superimposed on the surface of the object to be decorated, and a transfer sheet such as a roll transfer machine or an up-down transfer machine is used. Heat and pressure are applied from the base sheet side. By doing so, the transfer sheet adheres to the surface of the object to be decorated. Next, when the base sheet is peeled after cooling, the transfer layer is transferred to the surface of the object to be decorated, and the surface of the article is decorated.

  In in-mold molding, first, a transfer sheet is fed into a molding die in such a direction that the base sheet is in contact with the inner surface of the die. Next, the mold is closed, so that the molten resin is in contact with the adhesive layer side (opposite side of the base sheet) of the transfer sheet, that is, the transfer sheet is sandwiched between the molten resin and the inner surface of the mold. To fill the mold. As a result, the molten resin is molded, and at the same time, the transfer sheet is bonded to the surface of the resin molded product. The resin molded product is cooled, the mold is opened, and the resin molded product is taken out. Finally, when the base sheet is peeled off, the transfer layer is transferred to the surface of the resin molded product, and the surface of the resin molded product is decorated.

  The material of the object to be decorated is not particularly limited as long as it has been conventionally decorated with a transfer sheet, or can devise the components of the adhesive layer to adhere the transfer layer to the surface. Various synthetic resins, members made of metal, glass, wood, paper, and these coated and decorative objects are used as objects to be decorated. Particularly preferred objects to be decorated are transparent materials such as synthetic resin and glass. This is because the transfer layer of the present invention can have a transparent portion, and small bubbles are not generated in the portion for a long time even in a high humidity environment, and the transparency is maintained.

  The present invention will be specifically described by the following examples, but the present invention is not limited thereto. In the examples, the amount represented by “part” or “%” is based on weight unless otherwise specified.

Example 1
A polyethylene terephthalate film having a thickness of 38 μm was prepared as a base sheet. On this base sheet, a melamine resin release agent was applied and dried to form a release layer. Thereafter, a paint containing a UV curable resin was applied and dried to form a hard coat layer. On the hard coat layer, a paint containing a two-component curable acrylic urethane resin was applied and thermally cured to form a front anchor layer.

  A 5 cm × 4 cm aqueous resin layer was formed on the surface of the front anchor layer using an aqueous resin ink containing polyvinyl alcohol as a binder and silica as a pigment. A 15 nm thick tin thin film having an island-like structure and insulation was formed on the front anchor layer surface and the aqueous resin layer by vacuum evaporation. The tin thin film formed on the aqueous resin layer and the aqueous resin layer was removed by washing with water. On this, a coating containing an acrylic resin having a number average molecular weight (Mn) of 7,000, Tg of 43 ° C., a hydroxyl value of 13 and an acid value of 1 was applied and dried to form a post-anchor layer having a thickness of 1 μm from the tin thin film surface. . Further, a coating containing a vinyl chloride / vinyl acetate copolymer resin was applied and dried to form an adhesive layer, whereby a transfer film was obtained. In the above process, all the resin layers were formed by a gravure coating method.

  The obtained transfer film is put in a mold and in-mold molding of PMMA resin is performed to obtain a 2 mm thick PMMA resin plate having a transparent window portion of 5 cm × 4 cm and a metal color portion surrounding the window portion. It was.

  This PMMA decorative board was immersed in a 60 ° C. hot water bath for 4 hours. The PMMA decorative board taken out from the hot water bath was dried, and it was examined and evaluated whether small bubbles were generated in the window portion. The results are shown in Table 1.

Examples 2-5 and Comparative Examples 1-4
A transfer film was prepared in the same manner as in Example 1 except that the materials for forming the front anchor layer and the rear anchor layer were changed as shown in Table 1, and a transparent window portion of 5 cm × 4 cm and the window portion were surrounded. A 2 mm thick PMMA resin plate having a metallic portion was obtained and tested for moisture resistance. The results are shown in Table 1.

It is sectional drawing which shows the structure of the transfer sheet which is one Embodiment of this invention. It is process drawing which shows an example of the manufacturing method of the transfer sheet of this invention.

Explanation of symbols

1 ... Base sheet,
2 ... transfer layer,
3 ... Hard coat layer,
4 ... front anchor layer,
5 ... metal thin film,
6 ... Rear anchor layer,
7: Adhesive layer,
8: Water-soluble resin layer.

Claims (3)

A transfer sheet in which a transfer layer having at least a front anchor layer, a metal thin film and a rear anchor layer is formed on one side of a base sheet,
The front anchor layer is composed of at least one resin selected from the group consisting of a two-component curable acrylic urethane resin, a two-component curable polyester urethane resin, a nitrocellulose resin, and a melamine resin,
The metal thin film is an insulating metal thin film made of tin or indium formed on a part of the sheet surface of the transfer layer ,
A transfer sheet wherein the rear anchor layer comprises an acrylic resin or an acrylic urethane resin having a glass transition temperature of 40 to 120 ° C., a hydroxyl value of 10 to 200, and a number average molecular weight of 7,000 to 15,000 . Forming a front anchor layer as a layer constituting the transfer layer on one side of the base sheet;
Forming a metal thin film on a portion of the surface of the front anchor layer;
Forming a rear anchor layer on the entire surface thereof;
A transfer sheet manufacturing method comprising:
The front anchor layer is composed of at least one resin selected from the group consisting of a two-component curable acrylic urethane resin, a two-component curable polyester urethane resin, a nitrocellulose resin, and a melamine resin,
The metal thin film is an insulating metal thin film made of tin or indium;
A method for producing a transfer sheet, wherein the rear anchor layer comprises an acrylic resin or an acrylic urethane resin having a glass transition temperature of 40 to 120 ° C., a hydroxyl value of 10 to 200, and a number average molecular weight of 7,000 to 15,000 . Forming a front anchor layer as a layer constituting the transfer layer on one side of the base sheet;
Forming a water-soluble resin layer on a part of the surface of the front anchor layer;
Forming a metal thin film on the entire surface;
Removing the water-soluble resin layer and the metal thin film formed thereon by washing with water;
Forming a rear anchor layer on the entire surface thereof;
A transfer sheet manufacturing method comprising:
The front anchor layer is composed of at least one resin selected from the group consisting of a two-component curable acrylic urethane resin, a two-component curable polyester urethane resin, a nitrocellulose resin, and a melamine resin,
The metal thin film is an insulating metal thin film made of tin or indium;
A method for producing a transfer sheet, wherein the rear anchor layer comprises an acrylic resin or an acrylic urethane resin having a glass transition temperature of 40 to 120 ° C., a hydroxyl value of 10 to 200, and a number average molecular weight of 7,000 to 15,000 .

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