JP2010082964A - Transfer sheet having metal thin film in part of sheet surface and epoxy based anchor layer and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer sheet which does not cause generation of small bubbles in parts free of the metal thin film of the transfer layer and boundaries with the metal thin film even when a metal thin film is formed in parts of the sheet surface of a transfer layer and retains the small bubble suppression effect for a long time even in high-humidity circumstances. <P>SOLUTION: The transfer sheet includes a transfer layer formed on one side of a substrate sheet and having at least a front anchor layer, a metal thin film and a back anchor layer. The metal thin film is formed in part of the sheet surface of the transfer layer, and the back anchor layer contains an epoxy resin or an epoxy urethane resin softer than melamine resins. <P>COPYRIGHT: (C)2010,JPO&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. Although the metal thin film can achieve a metallic luster with such a small amount of metal, it 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.

  In the water removal method, 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, thereby washing the water-soluble resin layer and the top thereof. 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 this 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 metal thin film is formed on a part of the sheet surface of the transfer layer;
The post-anchor layer provides a transfer sheet comprising an epoxy resin or an epoxy urethane resin that is more flexible than the melamine resin, thereby achieving the above object.

  In one certain form, the said epoxy resin is the said transfer sheet which is at least 1 type selected from the group which consists of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a novolak type epoxy resin, and a novolak cresol type epoxy resin.

  In one certain form, it is one of the said transfer sheets whose said epoxy resin or epoxy urethane resin has a glass transition temperature of -30-140 degreeC.

  In one certain form, it is one of the said transfer sheets whose said epoxy resin or epoxy urethane resin has a hydroxyl value of 7-400.

  In one certain form, it is one of the said transfer sheets whose said epoxy resin or epoxy urethane resin has a number average molecular weight of 5000-50000.

  In one certain form, it is one of the said transfer sheets whose said metal thin film is an insulating metal thin film which consists of tin or indium.

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:
There is provided a method for producing a transfer sheet comprising an epoxy resin or an epoxy urethane resin in which the rear anchor layer is more flexible than a melamine resin.

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:
There is provided a method for producing a transfer sheet comprising an epoxy resin or an epoxy urethane resin in which the rear anchor layer is more flexible than a melamine resin.

  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 cross-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. 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 to design 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 embodiment, the metal thin film has metallic luster, insulation, radio wave transmission, and usage characteristics adjacent to the electrostatic switch as described in Patent Document 1 and the like. 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 from the surface of the front anchor layer at the end of the metal thin film, 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 140 ° C., preferably 15 to 120 ° C., more preferably 40 to 90 ° 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 epoxy resin or an epoxy urethane resin. This is because they are excellent in flexibility, have excellent adhesion to the preferred front anchor layer, and are less likely to generate small bubbles. If the glass transition temperature is too low, it is difficult to adjust the viscosity and the 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 epoxy resin here means resin which has an epoxy group in a molecule | numerator. The epoxy resin is obtained by reacting an epoxy compound having at least two epoxy groups in one molecule with a compound having a functional group that reacts with the epoxy group.

Specific examples of the epoxy compound are given below.
Diglycidyl ethers of aromatic diols such as bisphenol A, bisphenol F, resorcin, and hydroquinone.
Ethylene glycol, propylene glycol, neopentyl glycol, tetramethylene ether glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 3-methyl-1,5- Diglycidyl ethers of aliphatic diols such as pentanediol, ethylene glycol, polyethylene glycol and polypropylene glycol.
Triglycidyl ethers of aliphatic triols such as glycerol and trimethylolpropane.
Polyglycidyl ethers of aliphatic polyols such as polyglycerol.
Hydrogenated bisphenol A, hydrogenated bisphenol F, cyclopentanediol, cyclopentanedimethanol, cyclopentanediethanol, cyclohexanediol, cyclohexanedimethanol, cyclohexanediethanol, norbornanediol, norbornanedimethanol, norbornanediethanol, decalindiol, decalindimethanol, Diglycidyl ethers of alicyclic diols such as decalin diethanol, 3,4-epoxycyclohexylmethylcarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro 3,4-epoxy) cyclohexane-metadioxane Bis (3,4-epoxycyclohexyl) adipate.

  Examples of the functional group that reacts with the epoxy group include a hydroxyl group, a carboxyl group, and an amino group, and examples of the compound that reacts with the epoxy compound include diol, dicarboxylic acid, and diamine. Specific examples of these are given below.

  Examples of the diol include 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, tricyclodecane dimethanol, alkylene oxide adduct of tricyclodecane dimethanol, hydrogenated bisphenol A, Diols having a cyclic structure such as an alkylene oxide adduct of hydrogenated bisphenol A; and ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-dodecanediol, diethylene glycol, triethylene glycol, Dipropi Glycol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4- Chains such as trimethyl-1,3-pentanediol, 2-methyloctanediol, neopentylhydroxypivalate, alkylene oxide adducts of bisphenol A, polyethers such as polytetramethylene glycol, polypropylene glycol, and polyethylene glycol There are diols having a structure.

  Dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid tetrahydrophthalic acid, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid and other aromatic dicarboxylic acids; oxalic acid , Malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, heptanedioic acid, octanedioic acid, nonanedioic acid, decanedioic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanediic acid Acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosanedioic acid, maleic acid, fumaric acid, 1,6-cyclohexanedicarboxylic acid, cyclohexanedicarboxylic acid, tricyclodecanedicarboxylic acid, decalindicarboxylic acid, tri and tetracarboxylic Acid, trimellitic acid Aliphatic dicarboxylic acids such as pyromellitic acid; and sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5 (4-sulfophenoxy) isophthalic acid, There are sulfonic acid substituted dicarboxylic acids such as aromatic dicarboxylic acids such as, ammonium salts thereof, and metal salts thereof such as lithium, potassium, magnesium, calcium, copper, iron and the like.

  Examples of the diamine include ethylene diamine, pentamethylene diamine, hexamethylene diamine, tetramethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,4-trimethylhexamethylene diamine, 2, 4, Aliphatic diamines such as 4-trimethylhexamethylenediamine; and 2,3-diaminopyridine, 3,4-diaminopyridine, 2,6-diaminopyridine, 2,4-diaminopyrimidine, 4,5-diaminopyrimidine, 4 , 6-diaminopyrimidine, melamine, 1-phenyl-3,5-diaminotriazine, 1-methyl-3,5-diaminotriazine and other aromatic diamines.

  Types of epoxy resins include epibis epoxy resins, which are chain-extended with diols, dicarboxylic acids, diamines, etc .; epoxidized polybutadienes; novolac phenol type polyepoxy resins; novolac cresol type polyepoxy resins; polyglycidyl acrylates; fats And polyglycidyl ethers of group polyols or polyether polyols; polyglycidyl esters of polybasic carboxylic acids. Among these, general bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac phenol type polyepoxy resin, novolac cresol type polyepoxy resin, polyglycidyl which can increase adhesion with the resin by polyfunctionalization Acrylate is preferred.

  The epoxy urethane resin refers to an epoxy resin having a urethane bond and an epoxy group in the molecule. The epoxy urethane resin is obtained by reacting an epoxy compound having at least two epoxy groups in one molecule with a urethane compound having a functional group that reacts with the epoxy group. Examples of the functional group that reacts with the epoxy group include a hydroxyl group, a carboxyl group, and an amino group, and examples of the urethane compound that reacts with the epoxy compound include polyurethane diol, polyurethane dicarboxylic acid, and polyurethane diamine.

  The number average molecular weight of the epoxy resin or epoxy urethane resin is preferably 5,000 to 50,000, particularly preferably 7,000 to 30,000. When the number average molecular weight is less than 5,000, the toughness of the film is deteriorated, and when it exceeds 30,000, the flexibility is lowered, and when the molecular weight is further increased, the solubility in a solvent is deteriorated and the printability is deteriorated.

  The epoxy equivalent of the epoxy resin or epoxy urethane resin is preferably 150 to 20,000. When the epoxy equivalent is less than 150, the reactivity deteriorates, and when it exceeds 20,000, an unintended reaction occurs due to the reactivity being too high.

  More preferably, the epoxy resin or epoxy urethane resin used for the rear anchor layer has moderate hydrophilicity. Specifically, this resin has a hydroxyl value of 8 to 400, preferably 10 to 350, more preferably 10 to 250. The hydroxyl value here means a value measured by the method described in JISK0070. If the hydroxyl value is too low, the adhesion will be weak and small bubble bubbles will be generated after the moisture resistance test. If the hydroxyl value is too high, the compatibility with the solvent used in the gravure ink will be poor, resulting in a problem in printability.

  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.

  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.

The transfer sheet of the manufacturing method of the present invention the transfer sheet, except for the use of forming a metal thin film on a part of the seat surface of the transfer layer, the resin is more flexible than the melamine resins described above as a post-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 surface of the transfer sheet on the adhesive layer side (opposite side of the base sheet), that is, the transfer resin 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 photocurable 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. A paint containing a bisphenol A type epoxy resin having a number average molecular weight (Mn) of 30000, Tg of 85 ° C. and a hydroxyl value of 22 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 2-6 and Comparative Examples 1-3
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 (8)

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 metal thin film is formed on a part of the sheet surface of the transfer layer;
A transfer sheet comprising an epoxy resin or an epoxy urethane resin in which the rear anchor layer is more flexible than a melamine resin.   The transfer sheet according to claim 1, wherein the epoxy resin is at least one selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, and novolac cresol type epoxy resin.   The transfer sheet according to claim 1 or 2, wherein the epoxy resin or epoxy urethane resin has a glass transition temperature of -30 to 140 ° C.   The transfer sheet according to any one of claims 1 to 3, wherein the epoxy resin or epoxy urethane resin has a hydroxyl value of 7 to 400.   The transfer sheet according to any one of claims 1 to 4, wherein the epoxy resin or epoxy urethane resin has a number average molecular weight of 5,000 to 50,000.   The transfer sheet according to claim 1, wherein the metal thin film is an insulating metal thin film made of tin or indium. 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:
A method for producing a transfer sheet, wherein the rear anchor layer comprises an epoxy resin or an epoxy urethane resin that is more flexible than a melamine resin. 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:
A method for producing a transfer sheet, wherein the rear anchor layer comprises an epoxy resin or an epoxy urethane resin that is more flexible than a melamine resin.

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