JP2017007206A - Design metal sheet and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel and improved design metal sheet that can inhibit the deterioration of a design applied to a design film during the manufacture of the design metal sheet and can maintain an adhesion force between the design film and a metal sheet even under severe environment of high temperature and high humidity and to provide a method for manufacturing the design metal sheet.SOLUTION: The design metal sheet comprises a metal sheet 20, a lower layer side adhesive layer 41 laminated on the metal sheet, an upper layer side adhesive layer 42 laminated on the lower layer side adhesive layer, and a design film 30 laminated on the upper layer side adhesive layer. The lower layer side adhesive layer includes a lower layer side adhesive and the upper layer side adhesive layer includes an upper layer side adhesive. The upper layer side adhesive has a softening temperature of 80°C or lower and the lower layer side adhesive has a softening temperature of 90°C or higher.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a design metal plate and a manufacturing method thereof.

  In recent years, it has been designed for interior and exterior of various buildings (for example, interior and exterior walls of houses, roofs, partitions, etc.), furniture components, home appliance housings, truck bodywork, vehicle interior / exterior, ship interior / exterior, road protection walls, etc. Steel plates are increasingly being used. Of these uses, the design steel plate is often applied to the interior and exterior of a house, and is particularly often applied to the wall of a residential bathroom.

  Here, the design steel plate is obtained by laminating a design film on a steel plate. The design film is a film to which various designs (for example, color, pattern, emboss, etc.) are given. The design steel sheet is generally produced by the following steps. That is, first, an adhesive layer is formed on a steel plate or a design film by laminating (for example, coating) an adhesive on the steel plate or the design film. Here, an adhesive may be laminated | stacked on a steel plate or a design film in the state melt | dissolved in the solvent or disperse | distributed in the solvent. Next, the adhesive is softened by heating the adhesive layer. When the adhesive layer contains a solvent, the solvent evaporates by heating. Next, the steel plate and the design film are pressure-bonded. A design steel plate is produced by the above process.

  Patent documents 1-6 disclose the design steel plate in which the above-mentioned adhesion layer serves as a single layer. Patent Document 1 discloses a polyester-based adhesive in which a polyisocyanate-based curing agent is blended with a urethane-modified polyester main agent having a defined molecular weight and terminal functional group amount so that the NCO / OH ratio is within a predetermined range. . And in patent document 1, the adhesive layer which consists of a single layer is formed on a steel plate using this adhesive agent. And a design film and a steel plate are crimped | bonded.

  According to the technique disclosed in Patent Document 1, the wettability to the design film and the strength of the adhesive itself are maintained by defining the molecular weight of the main agent. Furthermore, the adhesiveness of a steel plate and a design film is ensured by defining a terminal functional group. And the cohesive force and pot life are optimized by prescribing the compounding ratio of the curing agents. The adhesive disclosed in Patent Document 1 is softened at a low temperature (for example, 180 ° C. or lower). Therefore, even if the heating temperature of the adhesive layer is low, the adhesive is sufficiently softened, so that the design film can be sufficiently adhered to the steel plate.

  Patent Document 2 discloses an acrylic adhesive obtained by crosslinking an acrylic polymer bonded to an epoxy resin with an amine compound. In patent document 2, the adhesive layer which consists of a single layer is formed on a steel plate using this adhesive agent. The adhesive disclosed in Patent Document 2 is also softened at a low temperature. Therefore, even if the heating temperature of the adhesive layer is low, the adhesive is sufficiently softened, so that the design film can be sufficiently adhered to the steel plate.

  Patent Document 3 discloses a polyester-based adhesive using a polyisocyanate to which a silane coupling agent is added as a curing agent. In patent document 3, the adhesive layer which consists of a single layer is formed on a steel plate using this adhesive agent. Patent Documents 4 to 6 also disclose commercially available polyester-based or urethane-based adhesives. Also in Patent Documents 4 to 6, a single-layer adhesive layer is formed using these adhesives. The adhesives disclosed in Patent Documents 3 to 6 are softened at a high temperature (for example, 210 to 230 ° C.). Therefore, when a design film is pressure-bonded to a steel sheet using these adhesives, it is necessary to make the heating temperature of the adhesive layer higher than the heating temperatures of Patent Documents 1 and 2.

  Patent documents 7 and 8 disclose a design steel plate having two adhesive layers. In Patent Document 7, the adhesive layer on the lower layer side (that is, the steel plate side) includes an adhesive mainly composed of a polar group-containing modified polyethylene resin, and the adhesive layer on the upper layer side (that is, the design film side) is modified with the polar group. Includes an adhesive mainly composed of polypropylene resin. The adhesive mainly composed of the polar group-containing modified polypropylene resin is an adhesive that softens at a high temperature, and the adhesive mainly composed of the polar group-containing modified polyethylene resin is an adhesive that softens at a low temperature.

  In patent document 7, a design steel plate is produced according to the following outline processes. That is, a plurality of adhesive layers are formed on the design film using a multilayer extruder. And the design film in which these contact bonding layers were formed is crimped | bonded to the steel plate heated previously. Then, the design film and the steel plate are heated to soften the adhesive on the lower layer side, and the design film is adhered to the steel plate. A design steel plate is produced by the above process. Here, since the lower layer side adhesive is composed of an adhesive that softens at a low temperature, the design film is sufficiently adhered to the steel plate even when the heating temperature for softening the lower layer side adhesive is low. be able to.

  In Patent Document 8, the lower layer side adhesive layer includes a urethane adhesive having a glass transition temperature of −65 to −10 ° C., and the upper layer side adhesive layer includes a polyester adhesive having a glass transition temperature of 20 to 90 ° C. . Since the above urethane-based adhesive has a low glass transition temperature, it softens at a low temperature. Since the above polyester-based adhesive has a high glass transition temperature, it softens at a high temperature. In patent document 8, a design steel plate is produced by the following processes. That is, the lower layer side adhesive layer is formed on a steel plate by laminating and heating an emulsion containing a urethane-based adhesive on the steel plate. And the emulsion containing a polyester-type adhesive agent is laminated | stacked on a lower layer side adhesive layer, and an upper layer side adhesive layer is formed on a lower layer side adhesive layer by heating. Next, a design film is laminated on the upper adhesive layer. Here, since the lower layer side adhesive layer is composed of an adhesive that softens at a low temperature, the design film should be sufficiently adhered to the steel plate even when the heating temperature for softening the lower layer side adhesive is low. Can do.

Japanese Patent Laid-Open No. 5-140340 JP 56-90874 A Japanese Patent Publication No. 6-78517 JP 2010-6020 A JP 2005-219504 A Japanese Patent Laid-Open No. 10-235782 Japanese Patent Application Laid-Open No. 64-82931 JP 2008-279687 A

  By the way, from the viewpoint of stabilizing the quality of the design steel plate, it has been required to lower the heating temperature for softening the adhesive as much as possible. That is, it has been demanded that the adhesive force of the adhesive at the time of producing the design steel sheet (such an adhesive force is also referred to as primary adhesive force) should be expressed as low as possible. This is because if the heating temperature for softening the adhesive is too high, the design imparted to the design film deteriorates (that is, the quality of the design steel plate decreases). Specifically, a large amount of heat is conducted to the design film in contact with the high-temperature adhesive, and the pigment in the design film is volatilized by this heat. Moreover, the unevenness | corrugation of embossing becomes shallow with the said heat (what is called embossing return). In particular, in recent years, since the design imparted to the design film tends to be sophisticated, it has been a very important issue to stabilize the quality of the design steel plate. Further, from the viewpoint of energy saving and productivity improvement, it has been required to lower the heating temperature as much as possible. Since the time required for heating is shortened as the heating temperature is lower, the productivity (production rate) of the design steel sheet is improved. In the design steel plates disclosed in Patent Literatures 1, 2, 7, and 8, the heating temperature for softening the adhesive can be lowered, and therefore, the design deterioration during the design steel plate production can be suppressed.

  On the other hand, as described above, the design steel plate is particularly often applied to the wall of a residential bathroom. Residential bathrooms are extremely harsh environments of high temperature and humidity, but design steel sheets maintain the adhesion between the design film and steel sheets for a long period of time (for example, 5 years or more) even in such harsh environments. There was a need to be able to do it. That is, the adhesive strength of the adhesive after fabrication of the design steel plate (such contact strength is also referred to as secondary adhesion strength) is the case where the design steel plate is used for a long period of time in a high temperature and high humidity environment. It was also required to be maintained at a high value.

  This inventor verified whether the design steel plate disclosed by patent documents 1, 2, 7, and 8 was adaptable to a high temperature and high humidity environment. Specifically, the design steel plates disclosed in Patent Documents 1, 2, 7, and 8 were produced, and an acceleration test was performed using these design steel plates. Here, the accelerated test is to immerse the design steel plate in boiling water for 2 hours. As a result, the adhesive layer was easily peeled off at the interface with the steel plate. Therefore, the design steel plates disclosed in Patent Documents 1, 2, 7, and 8 cannot be applied to a high temperature and high humidity environment.

  In the above acceleration test, factors such as “high temperature” and “water” act on the design steel plate. For this reason, in the above accelerated test, it is not known which factor causes the decrease in adhesion. Therefore, the present inventor conducted the following accelerated test in order to individually verify these factors. Specifically, the present inventor conducted an accelerated test in which the design steel sheet was heated to 100 ° C. in a vacuum as an accelerated test related to high temperature. As a result, no change in adhesion was observed before and after the acceleration test. Then, this inventor performed the accelerated test which immerses a design steel plate in 40 degreeC water for 2 hours as an accelerated test regarding water. As a result, no change in adhesion was observed before and after the acceleration test. Then, this inventor performed the accelerated test which immerses a design steel plate in 60 degreeC and 80 degreeC water for 2 hours as an accelerated test which combined high temperature and water, respectively. As a result, the adhesion was greatly reduced before and after the acceleration test. Specifically, the adhesive layer easily peeled off at the interface with the steel plate. As a result of the above, the present inventor has found that “water” and “high temperature” are causes of a decrease in adhesion.

  Furthermore, this inventor produced the design steel plate disclosed by patent documents 3-6, and performed the same accelerated test as the above (namely, the accelerated test which immerses a design steel plate in boiling water for 2 hours). As a result, there was almost no change in adhesion between before and after the acceleration test. Therefore, the design steel plates disclosed in Patent Documents 3 to 6 can be adapted to a high temperature and high humidity environment.

  And in the design steel plate disclosed by patent document 1, 2, 7, 8, the adhesive agent which contacts a steel plate softens at low temperature. On the other hand, in the design steel plates disclosed in Patent Documents 3 to 6, the adhesive contacting the steel plates is softened at a high temperature. Therefore, when the adhesive contacting the steel sheet softens at low temperatures, the design steel sheet cannot be adapted to a high temperature / humidity environment, but when the adhesive contacting the steel sheet softens at high temperature, the design steel sheet becomes a high temperature / humidity environment. Can adapt. The inventor believes that this is due to the difference in the softening degree of both adhesives.

  Graphs L1 and L2 shown in FIG. 1 are graphs showing the correspondence between the temperature and softening degree of different adhesives. The adhesive having the characteristics shown in the graph L1 (hereinafter, also referred to as “adhesive A”) is one type of adhesive that softens at a low temperature, and the adhesive having the characteristics shown in the graph L2 (hereinafter referred to as “adhesion”). (Also referred to as “agent B”) is one type of adhesive that softens at high temperatures. In addition, a softening degree is measured by the thermomechanical analyzer (Thermal Mechanical Analysis). Specifically, the degree of softening is obtained by pushing a small-diameter cylindrical needle into a sample with a predetermined load and dividing the penetration depth of the cylindrical needle at that time by the penetration depth at a predetermined temperature. The softening degree in FIG. 1 is obtained by dividing the penetration depth measured by pushing a cylindrical needle having a diameter of 1 mm into the sample with a load of 500 mN while the sample is heated at 2 ° C./min. By the penetration depth at 200 ° C. This is the value obtained. The penetration depth of the cylindrical needle into the sample is measured according to JIS-K-7196. In addition, the vertical axis in FIG. 1 gives a minus sign to the degree of softening for easy understanding.

  The degree of softening of the adhesive A rapidly increases from around 40 ° C., and softens to 0.7 or more at a temperature of 60 ° C. or higher. On the other hand, the softening degree of the adhesive B is maintained at a low value up to around 80 ° C. Here, an increase in the degree of softening of the adhesive means that the free volume of the adhesive is increased. And, as the free volume of the adhesive increases, water molecules are more likely to diffuse and penetrate into the adhesive. Therefore, when the adhesive A is heated to 60 ° C. or higher, a large amount of water molecules enter the adhesive A. On the other hand, even when the adhesive B is heated in the same manner, the amount of water molecules entering is lower than that of the adhesive A.

  And since the adhesive agent disclosed by patent document 1, 2 is softened at low temperature, it has the characteristic similar to the adhesive agent A. FIG. Therefore, when the design steel plates disclosed in Patent Documents 1 and 2 are exposed to a high temperature and high humidity environment, a large amount of water molecules enter the adhesive layer. And it is thought that these water molecules cut | disconnect the chemical bond formed in the steel plate / adhesion layer interface. That is, since the steel plate and the adhesive layer are bonded by dehydration condensation, the bond is hydrolyzed by water molecules that have entered the adhesive layer. Further, since the adhesive layer is plasticized and embrittled by water molecules, this is also considered to be a cause of a decrease in adhesion. For these reasons, when the design steel sheet disclosed in Patent Documents 1 and 2 is exposed to a high temperature and high humidity environment, the adhesive layer is considered to easily peel at the interface with the steel sheet. That is, it is considered that the secondary adhesion cannot be maintained in a high temperature and high humidity environment. On the other hand, since the adhesives disclosed in Patent Documents 3 to 6 are softened at a high temperature, they have the same characteristics as the adhesive B. Therefore, when the design steel plates disclosed in Patent Documents 3 to 6 are exposed to a high-temperature and high-humidity environment, water molecules can be prevented from entering the adhesive layer. For this reason, it is considered that the secondary adhesion is maintained even in a high temperature and high humidity environment.

  On the other hand, in the design steel plates disclosed in Patent Documents 7 and 8, the adhesive constituting the lower-layer side adhesive layer has the same characteristics as the adhesive A, and the adhesive constituting the upper-layer side adhesive layer is an adhesive. It has the same characteristics as B. For this reason, the upper adhesive layer functions as a barrier layer against water molecules. Therefore, the penetration | invasion of the water molecule from the design film side to a lower layer side adhesive layer is suppressed. However, since the lower layer-side adhesive layer is exposed at the end surface of the design steel plate, a large amount of water molecules enter from this portion. And the water molecule which penetrate | invaded into the lower layer side adhesion layer cut | disconnects the chemical bond formed in the steel plate / adhesion layer interface. Therefore, the design steel plates disclosed in Patent Documents 7 and 8 cannot maintain the secondary adhesion force in a high temperature and high humidity environment.

  Thus, the design steel plates disclosed in Patent Documents 3 to 6 can maintain the secondary adhesion even in a high temperature and high humidity environment. However, in order to express the primary adhesion, it was necessary to heat the adhesive layer to a high temperature when producing the design steel sheet. For this reason, there is a possibility that the design applied to the design film during the production of the design steel plate is greatly deteriorated. Therefore, it is possible to suppress the deterioration of the design applied to the design film during the production of the design steel plate, and to maintain the adhesion between the design film and the steel plate even under a severe environment of high temperature and high humidity. No possible design steel sheet has been proposed.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to suppress the deterioration of the design applied to the design film during the production of the design metal plate, and An object of the present invention is to provide a new and improved design metal plate capable of maintaining the adhesion between the design film and the metal plate even under a severe environment of high temperature and high humidity, and a method for producing the same.

  In order to solve the above problems, according to one aspect of the present invention, a metal plate, a lower layer side adhesive layer laminated on the metal plate, an upper layer side adhesive layer laminated on the lower layer side adhesive layer, and an upper layer A design film laminated on the side adhesive layer, the lower layer side adhesive layer includes a lower layer side adhesive, the upper layer side adhesive layer includes an upper layer side adhesive, and the softening temperature of the upper layer side adhesive is 80 There is provided a design metal plate characterized in that the temperature is not higher than ° C. and the softening temperature of the lower layer side adhesive is not lower than 90 ° C.

  Here, the softening temperature of the upper layer side adhesive may be 70 ° C. or less.

  The softening temperature of the lower layer side adhesive may be 100 ° C. or higher.

  Further, the lower layer side adhesive and the upper layer side adhesive may be made of any one or more of polyester-based, acrylic-based, urethane-based, epoxy-based, and urea-based thermosetting adhesives.

  Moreover, the lower layer side adhesive and the upper layer side adhesive are polyester systems in which 3 to 25 parts by mass of a polyisocyanate resin having an isocyanate group of 30 mol% or more based on all dicarboxylic acid residues is added to 100 parts by mass of a linear polyester resin. A thermosetting adhesive may be used.

  Moreover, the lower layer side adhesive layer may contain 2-15 mass parts of silane coupling agents with respect to 100 mass parts of lower layer side adhesives.

  Further, the design film may be composed of any one or more of a vinyl chloride resin, a polyester resin, an acrylic resin, a polyolefin resin, and a fluorine resin.

  Moreover, the softening temperature of the part which touches an upper layer side adhesive layer among design films may be less than 150 degreeC.

  According to another aspect of the present invention, there is provided a design metal plate manufacturing method for manufacturing the above-described design metal plate, wherein the metal plate and the design film at 180 ° C. or less are interposed through the lower layer side adhesive layer and the upper layer side adhesive layer. A method for producing a designed metal plate is provided.

  According to another aspect of the present invention, the lower layer side adhesive layer is formed by laminating the lower layer side adhesive on the metal plate, and forming the lower layer side adhesive layer on the metal plate, and heating the metal plate. A step of adhering the metal plate to the metal plate, a step of forming the upper layer side adhesive layer on the lower layer side adhesive layer by laminating the upper layer side adhesive on the lower layer side adhesive layer, and a heating temperature of 180 ° C. or less. The upper layer side adhesive is softened, and the step of laminating the design film on the upper layer side adhesive layer is performed. The softening temperature of the upper layer side adhesive is 80 ° C. or lower, and the lower layer side adhesive A softening temperature of the agent is 90 ° C. or higher, and a method for producing a design metal plate is provided.

  According to another aspect of the present invention, the lower layer side adhesive layer is formed by laminating the lower layer side adhesive on the metal plate, and forming the lower layer side adhesive layer on the metal plate, and heating the metal plate. In the state where the temperature of the metal plate is 180 ° C. or less, the step of preparing the laminated film in which the upper layer side adhesive layer including the upper layer side adhesive is laminated on the design film, Bonding the upper lower layer side adhesive layer and the upper layer side adhesive layer on the design film, the softening temperature of the upper layer side adhesive is 80 ° C or lower, and the softening temperature of the lower layer side adhesive is 90 ° C or higher The manufacturing method of the design metal plate characterized by these is provided.

  Here, the step of preparing the laminated film is the step of forming the upper layer side adhesive layer on the design film by laminating the upper layer side adhesive on the design film, and heating the design film, thereby bonding the upper layer side And a step of bringing the layer into close contact with the design film.

  Moreover, the lower layer side adhesive composition containing the lower layer side adhesive and the solvent is laminated on the metal plate to form the lower layer side adhesive layer, and the metal plate is heated, so that the solvent contained in the lower layer side adhesive layer May be evaporated and the lower adhesive layer may be adhered to the metal plate.

  Alternatively, the lower adhesive layer may be brought into close contact with the metal plate by heating the metal plate to a heating temperature higher than 180 ° C.

  The softening temperature of the upper layer side adhesive may be 70 ° C. or lower.

  The softening temperature of the lower layer side adhesive may be 100 ° C. or higher.

  Further, the lower layer side adhesive and the upper layer side adhesive may be made of any one or more of polyester-based, acrylic-based, urethane-based, epoxy-based, and urea-based thermosetting adhesives.

  Moreover, the lower layer side adhesive and the upper layer side adhesive are polyester systems in which 3 to 25 parts by mass of a polyisocyanate resin having an isocyanate group of 30 mol% or more based on all dicarboxylic acid residues is added to 100 parts by mass of a linear polyester resin. A thermosetting adhesive may be used.

  Moreover, a lower layer side adhesive layer is formed by laminating a lower layer side adhesive composition containing a lower layer side adhesive and a silane coupling agent on a metal plate, and the silane coupling agent is 100 parts by mass of the lower layer side adhesive. May be contained in the lower layer side adhesive composition at a ratio of 2 to 15 parts by mass with respect to the amount of the adhesive.

  Further, the design film may be composed of any one or more of a vinyl chloride resin, a polyester resin, an acrylic resin, a polyolefin resin, and a fluorine resin.

  Moreover, the softening temperature of the part which touches an upper layer side adhesive layer among design films may be less than 150 degreeC.

  As described above, according to the present invention, it is possible to suppress the deterioration of the design applied to the design film during the production of the design metal plate, and the design film even in a severe environment of high temperature and high humidity. The adhesion with the metal plate can be maintained.

It is a side view which shows schematic structure of the design metal plate which concerns on embodiment of this invention. It is a graph which shows the correspondence of the temperature of an adhesive agent, and a softening degree. It is a side view which shows an example of the manufacturing apparatus of a design metal plate. It is a side view which shows the other example of the manufacturing apparatus of a design metal plate.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. Structure of the design metal plate>
First, with reference to FIG. 2, the structure of the design metal plate 10 which concerns on embodiment of this invention is demonstrated. The design metal plate 10 includes a metal plate 20, a design film 30, and an adhesive layer 40. The adhesive layer 40 includes a lower layer side adhesive layer 41 laminated on the metal plate 20 and an upper layer side adhesive layer 42 laminated on the lower layer side adhesive layer 41. Therefore, the adhesive layer 40 has a two-layer structure. The design film 30 is laminated on the upper layer side adhesive layer 42.

(1-1. Configuration of steel plate)
The kind in particular of metal plate 20 is not restrict | limited, A widely well-known metal plate can be used. Examples of the metal plate 20 include a steel plate, a stainless steel plate, an Al plate, a Cu plate, a brass plate, a Ti plate, a chromium plate, a nickel plate, a zinc plate, and a magnesium plate.

  Here, as an example of the steel plate, tin plate, thin tin-plated steel plate, electrolytic chromate-treated steel plate (tin-free steel plate), steel plate for cans such as nickel-plated steel plate, hot-dip galvanized steel plate, hot-dip zinc-iron alloy plated steel plate, Hot-dip zinc-aluminum-magnesium alloy-plated steel plate, hot-dip aluminum-silicon alloy-plated steel plate, hot-dip-plated steel plate such as hot-dip lead-tin alloy-plated steel plate, electro-galvanized steel plate, electro-zinc-nickel-plated steel plate, electro-zinc-iron alloy-plated steel plate Electroplated steel sheets such as electrogalvanized-chromium alloy plated steel sheets, cold rolled steel sheets, and the like. The steel plate may be coated on either one side or both sides.

  The surface of the steel sheet may be subjected to various chemical conversion treatments for the purpose of enhancing adhesion with the adhesive layer 40 and improving rust prevention. Specific examples of the chemical conversion treatment include electrolytic chromate treatment, phosphoric acid chromate treatment, coating chromate treatment containing hexavalent chromium, cobalt and molybdenum composite plating treatment, various inorganic films (for example, vanadium, titanium, zirconium, aluminum, magnesium). , A process for coating a phosphorus-containing inorganic film), a process for coating various organic films (for example, an organic film containing polyacrylic acid resin, urethane resin, acrylic resin, etc.), a process for coating a silane coupling agent, etc. Can be mentioned.

  In the present embodiment, the lower layer side adhesive (the adhesive contained in the lower layer side adhesive layer 41) is softened at a high temperature, so that the penetration of water molecules into the lower layer side adhesive layer 41 can be suppressed. Therefore, even in a high-temperature and high-humidity environment, the adhesive force (secondary adhesive force) at the interface between the metal plate 20 and the lower layer side adhesive layer 41 can be maintained.

(1-2. Design film)
The type of the design film 30 is not particularly limited, and any design film used for a conventional design metal plate can be used as the design film 30 of the present embodiment. As described above, the design film 30 is provided with various designs (for example, color, pattern, emboss, etc.). Examples of the design film 30 include a single-color design film and a patterned design film. The monochromatic design film is a design film that is colored with a pigment. The surface of the monochromatic design film is often embossed. Such embossing suppresses light reflection. The design object design film is a design film that has been colored with a pigment and printed with a pattern. A transparent protective film for protecting the pattern may be further laminated on the surface of the patterned design film. Further, the patterned design film may be produced by pressure bonding a colored film colored with a pigment and a transparent protective film printed with a pattern. In this case, the pattern printing surface of the transparent protective film is directed to the colored film side.

  In this embodiment, the upper layer side adhesive (the adhesive contained in the upper layer side adhesive layer 42) is softened at a low temperature. Therefore, even if the heating temperature for softening the upper layer side adhesive is low, the design film 30 can be sufficiently adhered to the upper layer side adhesive layer 42. That is, the design film 30 can be sufficiently adhered to the metal plate 20. Therefore, the design film 30 can be sufficiently adhered to the metal plate 20 while suppressing deterioration of the design applied to the design film 30.

(1-2-1. Resin constituting the design film)
The resin constituting the design film 30 is not particularly limited. That is, if it is resin applied to the conventional design film, it is applicable also to the design film 30 of this embodiment. Examples of the resin constituting the design film 30 include a thermoplastic resin and a thermosetting resin. Examples of the thermoplastic resin include vinyl chloride resin, polyester resin, acrylic resin, polyolefin resin, and fluorine resin. Examples of thermosetting resins include urethane resins, urea resins, and epoxy resins. The design film 30 is preferably composed of any one or more of a vinyl chloride resin, a polyester resin, an acrylic resin, a polyolefin resin, and a fluorine-based resin among the above-described resins. Since the design film 30 made of these resins is excellent in printing wettability and embossability, it is easy to impart a high-level design. Hereinafter, examples of preferable resins will be described in detail.

  Vinyl chloride resin is a resin containing monomer units containing chlorine. Examples of vinyl chloride resin include polyvinyl chloride, chlorinated polyvinyl chloride, polyvinyl chloride, polyvinyl chloride, chlorinated polyethylene, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer. , Vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride terpolymer, vinyl chloride-styrene-acrylonitrile solution Polymer, vinyl chloride-butadiene copolymer, vinyl chloride-isoprene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-maleic acid ester copolymer Polymer, vinyl chloride-methacrylic acid ester copolymer, vinyl chloride-acrylonitrile copolymer , Chlorine-containing resins such as vinyl chloride-various vinyl ether copolymers, and their blends or synthetic resins not containing other chlorine, such as acrylonitrile-styrene copolymers, ethylene-vinyl acetate copolymers , Ethylene-ethyl (meth) acrylate copolymer, blends with polyester, block copolymers, graft copolymers, and the like.

  Further, when the design film 30 mainly composed of vinyl chloride resin is produced, the design film 30 is a diene resin not containing chlorine, MBS (methyl methacrylate butadiene styrene) for the purpose of improving impact resistance, weather resistance and the like. Copolymers), acrylic impact modifiers such as MBA (methyl methacrylate-butyl acrylate copolymer), and resins containing no chlorine such as acrylic resins and fluororesins. In the present embodiment, the “main component” of the design film 30 means a material contained in the design film 30 at a mass ratio of 50% by mass or more with respect to the total mass of the design film 30. The addition amount of these additives is preferably less than 50% by mass with respect to the total mass of the design film 30. When the addition amount of the additive is 50% by mass or more, the characteristics of the vinyl chloride resin may be hardly exhibited. Moreover, it is preferable that the addition amount of these additives is 3 mass% or more with respect to the total mass of the design film 30. If it is less than 3% by mass, the film may be destroyed when an impact force is applied to the design metal plate.

  Moreover, when producing the design film 30 which has a vinyl chloride resin as a main component, you may add a well-known plasticizer to the design film 30 in order to provide the flexibility of the design film 30, and a softness | flexibility. Examples of additives include phthalate plasticizers such as diheptyl phthalate, dioctyl phthalate, diisononyl phthalate, adipate plasticizers such as dioctyl adipate, diisononyl adipate, di (butyl diglycol) adipate, phosphates such as tricresyl phosphate Examples thereof include a plasticizer, a polyester plasticizer, a chlorinated paraffin plasticizer, a trimellitate plasticizer, a pyromellitate plasticizer, a biphenyltetracarboxylate plasticizer, and an epoxy plasticizer. The addition amount of the plasticizer is preferably 30% by mass or less with respect to the total mass of the design film 30. When the addition amount of the plasticizer is larger than 30% by mass, a large amount of the plasticizer may move to the surface when the design metal plate 10 is used for a long time. In this case, design properties and surface functions may be deteriorated, such as causing tackiness on the surface. Moreover, it is preferable that the addition amount of a plasticizer is 3 mass% or more with respect to the total mass of the costume film 30. FIG. If the amount is less than 3% by mass, the film is hard, and when the designed metal plate is processed, the film may not follow and may crack.

  Moreover, when producing the design film 30 which has a vinyl chloride resin as a main component, the design film 30 is made of an organic acid such as barium stearate for the purpose of improving thermal stability, weather resistance, concealment and impact resistance. Alkaline earth metal salts, organic acid zinc such as zinc stearate, 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, Hindered amine compounds such as 2,2,6,6-tetramethyl-4-piperidylbenzoate and bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, ultraviolet absorbers such as 2,4-dihydroxybenzophenone May be added. The addition amount of these additives is preferably 0.01 to 10% by mass with respect to the total mass of the design film 30. When the addition amount is less than 0.01% by mass, the function of the additive may not be sufficiently exhibited. On the other hand, when the addition amount is larger than 10% by mass, coloring or burning may occur.

  Moreover, when producing the design film 30 which has a vinyl chloride resin as a main component, pigments, such as a rutile type titanium dioxide and a calcium carbonate, are added to the design film 30 in order to provide the design film 30 with concealability. Also good. The addition amount of the pigment is preferably 1 to 30% by mass with respect to the total mass of the design film 30. When the addition amount is less than 1% by mass, the concealability may be insufficient. When the addition amount is larger than 30% by mass, the design film 30 becomes brittle and film formation may be difficult. From the viewpoint of film forming property and concealment stability, the amount of pigment added is more preferably 5 to 20% by mass.

  In the case of producing the design film 30 mainly composed of vinyl chloride resin, the design film 30 includes diphenylthiourea, diphenylurea, anilinodithiotriazine, melamine, benzoic acid, cinnamic acid, p as additives other than the above. -Stabilizers such as tert-butylbenzoic acid and zeolite may be added. For the design film 30, as necessary, a crosslinking agent, a foaming agent, an antistatic agent, an antifogging agent, a plate-out preventing agent, a surface treatment agent, a lubricant, a flame retardant, a fluorescent agent, an antifungal agent, a disinfectant, a metal You may add additives, such as an inactive agent, a mold release agent, a pigment, a processing aid, antioxidant, and a light stabilizer. These addition amounts are preferably 0.1 to 5% by mass with respect to the total mass of the design film 30. When the addition amount is 0.1% by mass, the function of the additive may not be sufficiently exhibited. When the addition amount is larger than 5% by mass, characteristics such as mechanical strength of the design film 30 may be deteriorated.

  Examples of the polyester resin include a polyester resin composed of a diol compound residue and a dicarboxylic acid compound residue, or a polyester resin obtained by substituting a part or all of these with a hydroxyl carboxylic acid compound residue. More specific examples include PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PET-I, PBT-I, PET-G, PCT-G, PAr (polyarylate), and co-components based on these. Examples thereof include a polymer resin and a mixture of two or more thereof.

  Here, PET-I is obtained by changing a part of the dicarboxylic acid residue of PET to an isophthalic acid residue. PBT-I is obtained by changing a part of the dicarboxylic acid residue of PBT to an isophthalic acid residue. PET-G is obtained by replacing a part of the diol residue of PET with a 1,4-cyclohexanedimethanol (1,4-CHDM) residue, and the mole of 1,4-CHDM residue in the diol residue. The ratio is 20% or more and less than 50% with respect to the total number of moles of diol residues. PCT-G is obtained by replacing a part of PET diol residues with 1,4-CHDM residues, and the molar ratio of 1,4-CHDM residues in the diol residues is the total moles of diol residues. It is 50% or more and 80% or less with respect to the number.

  The acrylic resin is a resin mainly composed of acrylic acid ester or methacrylic acid ester. Examples of the acrylate ester include methyl acrylate, ethyl acrylate, butyl acrylate and the like. Examples of methacrylic acid esters include methyl methacrylate, methyl methacrylate, butyl methacrylate and the like. When producing the design film 30 mainly composed of acrylic resin, an acrylic impact modifier such as MBS or MBA may be added to the design film 30 for the purpose of improving the workability of the design film 30.

  Examples of the polyolefin resin include polyethylene resin, polypropylene resin, ethylene-propylene copolymer resin, and the like.

  Examples of fluororesins include PVF (polyvinyl fluoride), PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), PFA (polytetrafluoroethylene), PFEP (hexafluoroethylene propylene), etc. In addition to a resin having a fluorine skeleton, a copolymer of a fluorine-containing monomer and an olefin, a copolymer of a fluorine-containing monomer and a chlorine-containing monomer, and the like can be given. Examples of the copolymer of a fluorine-containing monomer and an olefin include ETFE (a copolymer of tetrafluoroethylene and ethylene). Examples of the copolymer of the fluorine-containing monomer and the chlorine-containing monomer include PCTFE (polychlorotrifluoroethylene), ECTFE (copolymer of ethylene and chlorotrifluoroethylene) and the like.

  Among the resins listed above, particularly preferred resins are vinyl chloride resin, PET, PBT, PET-G, PET-I, PBT-I, PVF, PVDF, acrylic resin mainly composed of methyl methacrylate, Polyethylene resin and polypropylene resin. The design film 30 composed mainly of these resins is particularly excellent in printing wettability and embossability, and the design film 30 composed of these resins is also excellent in productivity.

(1-2-2. Softening temperature)
The softening temperature of the design film 30 is not particularly limited, but the softening temperature of the portion in contact with the upper adhesive layer 42 is preferably less than 150 ° C. Here, the softening temperature is measured by a thermal mechanical analysis device (Thermal Mechanical Analysis). Specifically, a cylindrical needle having a diameter of 1 mm is pushed into the sample with a load of 500 mN while heating the sample at 2 ° C./min. And let the temperature when the penetration | invasion depth of the cylindrical needle | hook into a sample satisfy | fills the following numerical formula (1) be softening temperature. The penetration depth of the cylindrical needle into the sample is measured according to JIS-K-7196.
t _i / t ₂₀₀ = 0.8 (1)
In Equation (1), t _i is the penetration depth, and t ₂₀₀ is the penetration depth when the sample temperature is 200 ° C. Therefore, the left side of Equation (1) indicates the degree of softening.

  When the softening temperature of the portion in contact with the upper layer-side adhesive layer 42 (hereinafter also referred to as “adhesion layer contact portion”) is less than 150 ° C., the design film 30 and the upper layer side are suppressed while suppressing the deterioration of the design when the design metal plate is produced. The adhesion strength with the adhesive layer 42 can be improved. That is, even when the adhesive layer contact portion is heated to a temperature of 180 ° C. or lower, the adhesive layer is sufficiently softened, so that the adhesion with the upper adhesive layer 42 can be improved. In other words, the adhesive layer contact portion can exhibit a sufficient anchor effect. Moreover, since the heating temperature of the design film 30 is 180 ° C. or less, the deterioration of the design is suppressed.

  Examples of the resin having a softening temperature of less than 150 ° C. include the above-described PET, PBT-I, PET-G, an acrylic resin mainly composed of methyl methacrylate, and a polyethylene resin. Therefore, the adhesive layer contact portion may be formed with these resins.

(1-2-3. Thickness of design film)
The thickness of the design film 30 is not particularly limited. However, from the viewpoint of effectively using the effects of the present embodiment, the thickness of the design film 30 is preferably 5 to 400 μm, and more preferably 5 to 150 μm.

  The adhesives disclosed in Patent Documents 3 to 6 are softened at a high temperature. That is, these adhesives hardly exhibit an anchor effect unless the heating temperature is increased. For this reason, it is necessary to pressure-bond the design film to the high-temperature adhesive layer when producing the design metal plate. Therefore, when the thickness of the design film is less than 80 μm, large heat is conducted to the surface of the design film when the design film is pressure-bonded to the adhesive layer. And the design of the design film surface deteriorates by this heat. Therefore, in order to maintain the design applied to the design film, the thickness of the design film needs to be 80 μm or more. However, when the thickness of the design film is 200 μm or more, a large thermal stress is generated due to a difference in thermal expansion between the steel plate and the design film when the design film is pressure-bonded to the steel plate. As a result, the adhesive force due to the adhesive is reduced. Further, the design film may be warped.

  On the other hand, in this embodiment, the upper layer side adhesive contained in the upper layer side adhesive layer 42 (that is, the adhesive layer on the design film 30 side) is softened at a low temperature. Therefore, in this embodiment, even if the upper layer side adhesive layer 42 is low temperature, the upper layer side adhesive layer 42 and the design film 30 can fully adhere | attach. That is, the heat conducted to the design film 30 can be reduced. For this reason, even if the thickness of the design film 30 is less than 80 μm, deterioration of the design applied to the design film 30 can be suppressed. Moreover, since the heat conducted to the design film 30 can be reduced, even if the thickness of the design film 30 is 200 μm or more, the stress generated by the difference in thermal expansion between the metal plate 20 and the design film 30 Can be reduced. That is, even if the thickness of the design film 30 is 200 μm or more, it is possible to suppress a decrease in adhesion and warpage of the design film 30. However, when the thickness of the design film 30 is less than 5 μm, heat may be conducted to the surface of the design film 30 and the design may deteriorate. Moreover, when the thickness of the design film 30 exceeds 400 μm, the manufacturing cost of the design film 30 may increase. For this reason, it is preferable that the thickness of the design film 30 is 5-400 micrometers.

(1-3. Structure of adhesive layer)
The adhesive layer 40 includes a lower layer side adhesive layer 41 and an upper layer side adhesive layer 42. The lower layer side adhesive layer 41 is in close contact with the metal plate 20, and the upper layer side adhesive layer 42 is in close contact with the design film 30. The lower layer side adhesive layer 41 includes a lower layer side adhesive agent, and the upper layer side adhesive layer 42 includes an upper layer side adhesive agent. The softening temperature _{(T under)} of the lower-side adhesion agents are 90 ° C. or more, the softening temperature _{(T Stay up-)} on the upper layer side adhesive is 80 ° C. or less. In the case where the adhesive is a thermosetting adhesive, a value measured with a film composed only of an adhesive main agent not containing a curing agent is defined as the softening temperature of the adhesive.

  Thus, since the upper layer side adhesive is sufficiently softened at a low temperature (for example, a temperature of 180 ° C. or lower), even when the low temperature upper layer adhesive layer 42 and the design film 30 are adhered, the upper layer side adhesive The anchor effect of the agent on the design film 30 can be sufficiently exhibited. That is, the upper layer side adhesive penetrates deeply into the unevenness of the design film 30 and can sufficiently secure a contact area with the design film 30. As a result, the design film 30 and the upper-side adhesive layer 42 can be adhered to each other with a sufficiently strong adhesion that can withstand bending, overhanging, and the like. Moreover, since the heat conducted to the design film 30 can be reduced, deterioration of the design applied to the design film 30 can be suppressed.

  Furthermore, since the lower layer side adhesive is softened at a high temperature, even if the design metal plate 10 is exposed to a high temperature and high humidity environment for a long period of time, the intrusion of water molecules into the lower layer side adhesive layer 41 can be suppressed. Therefore, the chemical bond between the lower layer side adhesive layer 41 / metal plate 20 can be maintained. Here, although the lower layer side adhesive layer 41 is exposed from the end surface of the design metal plate 10, the penetration | invasion of the water molecule from this exposed surface is also suppressed. In addition, since the upper layer side adhesive layer 42 is exposed at the end surface of the design metal plate 10, water molecules may enter the upper layer side adhesive layer 42 from the end surface. However, since water molecules in the upper layer side adhesive layer 42 cannot penetrate into the lower layer side adhesive layer 41, they cannot reach the interface between the lower layer side adhesive layer 41 and the metal plate 20. In addition, it is estimated that the water molecules in the upper layer side adhesive layer 42 do not affect the bonding at the interface between the upper layer side adhesive layer 42 and the design film 30. This is because peeling of the design film 30 occurs at the interface between the steel plate and the adhesive layer by the accelerated test by the present inventor. Therefore, even if the design metal plate 10 is exposed to a high temperature and high humidity environment for a long time, the secondary adhesion can be maintained for a long time.

  As described above, according to the present embodiment, it is possible to suppress the deterioration of the design applied to the design film 30 when the design metal plate 10 is manufactured, and the design is possible even in a severe environment of high temperature and high humidity. The adhesion between the film 30 and the metal plate 20 can be maintained. Therefore, the design film 30 can be produced with little consideration of the influence of heat on the design film 30 (for example, deterioration of the design). That is, as described above, it is necessary to form an adhesive layer using an adhesive having a high softening temperature from the viewpoint of maintaining the secondary adhesion of the design metal plate in a high temperature and high humidity environment. However, in this case, it is necessary to pressure-bond the design film to the high-temperature adhesive layer. Therefore, the influence of the heat which a design film receives is very large. For this reason, when producing a design film, it is necessary to consider the influence of such heat. For example, it is necessary to perform operations such as selecting a material having high heat resistance and increasing the thickness of the design film. However, in the present embodiment, the upper-layer adhesive layer 42 that is pressure-bonded to the design film 30 is composed of an adhesive having a low softening temperature. Therefore, when producing the design film 30, there is almost no need to consider the influence of heat. For this reason, for example, the range of choices of materials is expanded. Further, as described above, the thickness of the design film 30 can be selected from a wider range of values.

  Here, the softening temperature of the upper layer side adhesive is preferably 70 ° C. or lower. In this case, the upper layer side adhesive is sufficiently softened even at a low heating temperature such as 165 ° C. or lower. Therefore, even when the upper layer side adhesive layer 42 heated to this temperature and the design film 30 are brought into close contact with each other, the anchor effect of the upper layer side adhesive on the design film 30 can be sufficiently exhibited.

  Moreover, it is preferable that the softening temperature of a lower layer side adhesive agent is 100 degreeC or more. In this case, even under an extremely severe environment in which the design metal plate 10 is immersed in hot water, the penetration of water molecules into the lower layer side adhesive layer 41 can be suppressed. Therefore, even in such an extremely severe environment, the secondary adhesion can be maintained for a long time. Furthermore, the difference between the softening temperature of the lower layer side adhesive and the softening temperature of the upper layer side adhesive is preferably 30 ° C. or more. In this case, it is possible to express a strong secondary adhesion force while more stably holding the design applied to the design film.

(1-3-1. Specific examples of adhesive)
The adhesive constituting the lower layer side adhesive and the upper layer side adhesive may be any as long as it satisfies the aforementioned softening temperature conditions. Examples of the adhesive constituting the lower layer side adhesive and the upper layer side adhesive include a solvent type adhesive, a water-based adhesive, a hot melt type adhesive, an elastic adhesive, a thermosetting (thermosetting reaction type) adhesive, Examples include pressure sensitive adhesives and natural product adhesives.

  Examples of solvent-type adhesives include rubber adhesives and resin adhesives. Here, examples of rubber adhesives include natural rubber (polyisoprene), butyl rubber, and styrene butadiene rubber adhesives. Examples of the resin adhesive include a vinyl acetate resin adhesive, a urethane resin adhesive, and an ethylene vinyl acetate copolymer resin adhesive.

  Examples of water-based adhesives include water-soluble adhesives, emulsion adhesives, and latex adhesives. Examples of the water-soluble adhesive include starch paste, poval paste, aqueous polymer-isocyanate adhesive, polyvinyl pyrrolidone adhesive, gum arabic adhesive, and the like. Examples of emulsion adhesives include emulsion adhesives composed of vinyl acetate resin emulsions, EVA resin emulsions, acrylic emulsions, urethane emulsions, and the like. Examples of latex adhesives include latex adhesives made from rubber such as chloroprene rubber.

  Examples of the hot-melt adhesive include thermoplastic elastomer-based, EVA (ethylene vinyl acetate copolymer) -based, olefin-based, polyamide-based, urethane-based, and polyester-based hot-melt adhesives. Here, as an example of a thermoplastic elastomer-based hot melt adhesive, a thermoplastic elastomer-based hot melt adhesive mainly composed of a synthetic rubber such as SBS (styrene-butadiene-styrene) or SIS (styrene-isoprene-styrene). An adhesive etc. are mentioned. Examples of the olefinic hot melt adhesive include olefinic hot melt adhesives mainly composed of amorphous polypropylene.

  Examples of elastic adhesives include silicone adhesives based on siloxane, modified silicone resin adhesives based on modified silicone polymers with hydrolyzable silyl groups introduced into various polyethers, and silylated urethane adhesives. Agents and the like.

  Examples of thermosetting adhesives include epoxy resin adhesives obtained by crosslinking and condensing epoxy resins with curing agents, as well as urethane, urea, melamine, phenolic, acrylic, cyanoacrylate, and polyester heats. Examples thereof include a cured adhesive.

  Examples of pressure sensitive adhesives include acrylic, rubber, and silicon pressure sensitive adhesives. Examples of natural product adhesives include natural product adhesives composed of glue, gelatin, fibrin, water glass, and the like.

  Among the adhesives listed above, particularly preferable adhesives are polyester-based, acrylic-based, urethane-based, epoxy-based, and urea-based thermosetting adhesives. These adhesives are easy to handle at the time of manufacture of the design metal plate 10 and are excellent in affinity with the metal plate 20 and the design film 30 and stability against heat and humidity. Further, among these adhesives, a polyester thermosetting adhesive is particularly preferable. This is because this adhesive is particularly excellent in handling property, adhesion, and strength of the adhesive itself in addition to the above characteristics. Hereinafter, the polyester thermosetting adhesive will be described in detail.

  Polyester-based thermosetting adhesives include polyester resins, urethane-modified polyester resins in which polyisocyanate compounds are blended with polyester diols, and substrates based on epoxy-modified polyester resins in which polyester diols are modified with epoxy resins. And an adhesive crosslinked with a crosslinking agent such as a blocked isocyanate compound or an amino resin.

  Here, examples of the polyester resin as the main component include a polyester resin composed of a dicarboxylic acid residue and a diol residue. Examples of dicarboxylic acid residues include terephthalic acid residues, isophthalic acid residues, phthalic anhydride residues, aromatic carboxylic acid residues such as α or β-naphthalenedicarboxylic acid residues, oxalic acid residues, glutaric acid Residue, adipic acid residue, pimelic acid residue, suberic acid residue, azelaic acid residue, sebacic acid residue, undecylenic acid residue, etc., aliphatic dicarboxylic acid residue, 1,4-cyclohexanedicarboxylic acid residue And alicyclic dicarboxylic acid residues such as tetrahydrophthalic anhydride residue and hexahydrophthalic anhydride residue. Examples of diol residues include ethylene glycol residues, 1,4-butanediol residues, diethylene glycol residues, propylene glycol residues, 1,3-butylene glycol residues, 1,6-hexane glycol residues, and trimethylpropanol residues. Group, trimethylolethane residue and the like.

  Moreover, as an example of the said polyester diol, the polyester diol which made the both ends of said polyester resin into the hydroxyl group is mentioned. Examples of the polyisocyanate compound include diisocyanate compounds such as triresin isocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, and tetramethylene diisocyanate, and compounds of these dimers or more. Examples of the epoxy-modified polyester resin include bisphenol A type or bisphenol F type epoxy-modified polyester resin.

  Examples of the isocyanate compound crosslinked to the main component include aliphatic, alicyclic, or aromatic di- or triisocyanate compounds having two or more isocyanate groups. More specific examples of the isocyanate compound include polyphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4-dicyclohexylmethadiisocyanate, triphenylmethane triisocyanate, polymethylene polyphenylene polyisocyanate, and the like.

  As an example of a blocked isocyanate compound, the isocyanate etc. which blocked each said isocyanate compound with the following isocyanate blocking agent are mentioned. Here, examples of isocyanate blocking agents include phenolic blocking agents such as phenol, thiophenol, methylthiophenol, cresol, xylenol, resorcinol, nitrophenol, chlorophenol, and oxime blocks such as acetoxime, methyl ethyl ketoxime, and cyclohexanone oxime. Agents, alcohol blocking agents such as methanol, ethanol, propanol and butanol, halogen-substituted alcohol blocking agents such as ethylene chlorohydrin and 1,3-dichloro-2-propanol, and t-butanol and t-pentanol. Examples include tertiary alcohol-based blocking agents, ε-caprolactam, δ-valerolactam, γ-butyrolactam, and β-propyllactam. Other examples of blocking agents include aromatic amines, imides, acetylacetone, acetoacetate ester, malonic acid ethyl ester and other active methylene compounds, mercaptans, imines, ureas, diaryl compounds and sodium bisulfite. Can be mentioned.

  Examples of the amino resin include amino resins obtained by condensation reaction of compounds containing amino groups such as urea, melamine, and benzoguanamine with formaldehyde, and these amino resins and alcohols having 1 to 6 carbon atoms. Examples include alkyl ether compounds obtained by a condensation reaction. More specific examples of amino resins include methoxylated methylol urea, methoxylated methylol-N, N-ethyleneurea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol Examples include benzoguanamine.

The polyester thermosetting adhesive has an amine catalyst such as butylamine, hexylamine, oxylamine, BF ₃ (boron trifluoride) amine complex compound, 1,8- Diazabicyclo (5,4,0) undecene-7, imidazole, etc. may be added. Of these additives, tertiary amines having a large catalytic action are most preferable.

  Among the above-mentioned polyester-based thermosetting adhesives, particularly preferred examples include 3 to 25 masses of polyisocyanate having two or more isocyanate groups with respect to 100 mass parts of a linear polyester resin composed of an aromatic dicarboxylic acid and a diol residue. This is a polyester thermosetting adhesive to which parts are added. This polyester thermosetting adhesive is particularly excellent in affinity with the metal plate 20 and the design film 30. Furthermore, since this polyester thermosetting adhesive has a strong self-cohesive force and the strength of the adhesive itself is high, cohesive failure of the adhesive can be prevented.

  Moreover, bridge | crosslinking can be further advanced at the time of heating by adding 3 mass parts or more of polyisocyanate to linear polyester resin. For this reason, cohesion force improves more. Furthermore, by making the addition amount of polyisocyanate 25 parts by mass or less, moderate ductility can be imparted to the polyester thermosetting adhesive. For this reason, the workability of the polyester thermosetting adhesive can be improved. Moreover, when pot life is required, it is preferable to use 80 mass parts or more of blocked isocyanate with respect to all the isocyanate components.

  Here, as an example of the linear polyester resin, any one of an aromatic carboxylic acid residue containing a terephthalic acid residue, an ethylene glycol residue, a neopentyl glycol residue, and a 2-methyl-1,3-propanediol residue is used. And a linear polyester resin composed of a diol residue. Here, the linear polyester resin preferably contains terephthalic acid residues in an amount of 30 mol% or more based on the total dicarboxylic acid residues. When the content is less than 30 mol%, the cohesive force of the adhesive itself is insufficient. As a result, the proof stress against residual stress due to thermal strain applied during lamination is reduced. Therefore, when the design metal plate 10 is exposed to a high temperature and high humidity environment for a long time, the adhesive itself may be broken and peeled off. Moreover, it is preferable that linear polyester resin contains 60 mol% or more of said diol residues with respect to all the diol residues. When the content is less than 60 mol%, the solubility of the polyester-based thermosetting adhesive in the solvent may deteriorate, and the adhesive concentration may not be constant in the pot.

  Various additives can be added to the adhesive layer 40. Examples of such additives include organic compounds, inorganic compounds, various pigments composed of metal oxides (for example, rust preventive pigments, colored pigments, extender pigments, etc.), benzophenone-based, benzotriazole-based, triazine-based, and the like. UV absorbers, hindered amine light stabilizers, hindered phenols, phosphorus, sulfur, tocopherols and other antioxidants, silane coupling agents such as epoxy silanes, vinyl silanes, mercapto silanes and amino silanes Adhesive agents such as rosin resin, xylene resin and epoxy resin, ultra particles such as anhydrous silica, flame retardant, viscosity modifier, coating film reinforcing agent, antifoaming agent, surface smoothing agent and the like.

  In particular, it is preferable that a silane coupling agent is added to the lower layer side adhesive layer 41 in order to reinforce the adhesion with the metal plate 20. It is preferable that the addition amount of a silane coupling agent is 2-15 mass parts with respect to 100 mass parts of lower layer side adhesives. When the addition amount of the silane coupling agent is less than 2 parts by mass, the effect of improving the adhesion to the metal plate 20 is small. When the addition amount of the silane coupling agent exceeds 15 parts by mass, the adhesion force to the upper adhesive layer 42 may be reduced. Further, from the viewpoint of improving the water-resistant adhesion, the silane coupling agent is preferably organized by reaction with maleic anhydride.

(1-3-2. Thickness of adhesive layer)
The layer thickness of the lower layer side adhesive layer 41 and the upper layer side adhesive layer 42 is not particularly limited. These thicknesses can be appropriately selected according to the characteristics required for the design metal plate 10. However, the thickness of both layers is preferably 1 μm or more. When the thickness is less than 1 μm, there is a possibility that each layer cannot function efficiently. Further, from the viewpoint of economy, the thickness of each layer is preferably 20 μm or less.

(1-3-3. Layer structure)
One or a plurality of other adhesive layers may be interposed between the lower layer side adhesive layer 41 and the upper layer side adhesive layer 42.

<2. Manufacturing method of design metal plate>
In the manufacturing method of the design metal plate 10, the temperature at which the design film is heated is 180 ° C. or less in these steps when there is a step in which the design film is laminated on the steel sheet and a step in which an adhesive is laminated on the design film. If there is, there is no particular limitation. In the present embodiment, the design film is not heated to 180 ° C. or higher in the laminating process. And since the softening temperature of the upper layer side adhesive which comprises the upper layer side adhesive layer 42 is 80 degrees C or less, even if the temperature of the metal plate 20 is 180 degrees C or less, the upper layer side adhesive is fully softened. Therefore, the design film 30 and the metal plate 20 can be firmly adhered. As specific examples of the manufacturing method of the design metal plate 10, the following first example and second example are given.

(3-1. First example)
In the first example, the design metal plate 10 is produced by the following steps. First, the lower layer side adhesive layer 41 is formed on the metal plate 20 by applying the lower layer side adhesive composition on the metal plate 20. Next, the lower layer side adhesive layer 41 is heated to bring the lower layer side adhesive into close contact with the metal plate 20. Here, the heating temperature of the metal plate 20 is not particularly limited as long as the lower layer side adhesive is in close contact with the metal plate 20. For example, as described above, the heating temperature may be adjusted depending on whether or not the lower layer side adhesive layer 41 contains a solvent.

  Next, the upper layer side adhesive layer 42 is formed on the lower layer side adhesive layer 41 by coating the upper layer side adhesive composition on the lower layer side adhesive layer 41. Next, the upper layer side adhesive is softened by heating the metal plate 20 to a heating temperature of 180 ° C. or lower. Thus, in this embodiment, the heating temperature of the metal plate 20 is lowered. However, as described above, since the softening temperature of the upper layer side adhesive is low, the upper layer side adhesive is sufficiently softened even at such a heating temperature. Moreover, since the low temperature upper side adhesive layer 42 can be pressure-bonded to the design film 30, the heat conducted to the design film 30 can be reduced. Therefore, deterioration of the design applied to the design film 30 can be suppressed. Next, the design film 30 is pressure-bonded to the upper layer side adhesive layer 42. Thereby, the design metal plate 10 is produced. The design metal plate 10 is appropriately cooled.

(3-2. Second example)
In the second example, the design metal plate 10 is produced by the following steps. First, the lower layer side adhesive layer 41 is formed on the metal plate 20 by applying the lower layer side adhesive composition on the metal plate 20. Next, the lower layer side adhesive is brought into close contact with the metal plate 20 by heating the metal plate 20. Here, the heating temperature of the metal plate 20 is not particularly limited as long as the lower layer side adhesive is in close contact with the metal plate 20. For example, as described above, the heating temperature may be adjusted depending on whether or not the lower layer side adhesive layer 41 contains a solvent.

  On the other hand, the upper layer side adhesive layer 42 is formed on the design film 30 by applying the upper layer side adhesive composition on the design film 30. Next, the upper adhesive layer 42 is brought into close contact with the design film 30 by heating the design film 30. Here, the heating temperature of the design film 30 is a temperature at which the upper layer side adhesive layer 42 is in close contact with the design film 30, that is, a temperature at which the upper layer side adhesive exhibits an anchor effect on the design film 30 and is 180 ° C. or less. There is no limit.

  Next, the upper adhesive layer 42 on the design film 30 is pressure-bonded to the lower adhesive layer 41 on the metal plate 20 with the temperature of the metal plate 20 being 180 ° C. or lower. The design metal plate 10 is produced by bonding the lower layer side adhesive layer 41 and the upper layer side adhesive layer 42 together. As described above, since the softening temperature of the upper layer side adhesive is low, the upper layer side adhesive is sufficiently softened even when the temperature of the metal plate 20 is 180 ° C. or lower. Moreover, since the low temperature upper side adhesive layer 42 can be pressure-bonded to the design film 30, the heat conducted to the design film 30 can be reduced. Therefore, deterioration of the design applied to the design film 30 can be suppressed. The design metal plate 10 is appropriately cooled.

The manufacturing method of the design metal plate 10 is not limited to the first example and the second example described above. That is, in the first example and the second example described above, the design metal plate 10 is continuously produced, but the design metal plate 10 may be produced by a badge type manufacturing method. For example, the metal plate 20 on which the lower layer side adhesive layer 41 and the upper layer side adhesive layer 42 are laminated may be cut into a predetermined area, and the design film 30 may be laminated on the metal plate 20 with a batch-type thermocompression bonding apparatus.
<2. Configuration example of design metal plate manufacturing equipment>

  The first example of the manufacturing method is realized by using, for example, the manufacturing apparatus 100 shown in FIG. Therefore, the configuration of the manufacturing apparatus 100 will be described. Of course, the manufacturing apparatus of the design metal plate 10 is not limited to the manufacturing apparatus 100 shown in FIG. 3 and the manufacturing apparatus 101 described later. That is, any apparatus may be used as long as it is a manufacturing apparatus capable of producing the design metal plate 10 having the above-described structure. For example, in the following manufacturing apparatuses 100 and 101, each adhesive layer is formed by a roll coater method, but each adhesive layer is formed by other methods such as a spray coating method, a dip method, or a method of laminating a film adhesive. It may be formed.

  The manufacturing apparatus 100 includes a transport device (not shown) for the metal plate 20, a first roll coater 120, a first oven 130, a second roll coater 140, a second oven 150, a design film transport device 160, A crimping roll pair 163 and a cooling device 170 are provided.

  The conveying device for the metal plate 20 conveys the metal plate 20 from the left end to the right end in FIG. The first roll coater 120 is a device for laminating the lower layer side adhesive layer 41 on the metal plate 20, and includes a coater pan (pot) 121 a, a pickup roll 122, an applicator roll 123, and a backup roll 124.

  The coater pan 121a is a device that stores the lower layer side adhesive composition 121 including the lower layer side adhesive. The lower layer side adhesive composition 121 may include a solvent in addition to the lower layer side adhesive, and may further include an additive constituting the lower layer side adhesive layer 41. Here, the solvent is used for the purpose of adjusting the viscosity of the lower layer side adhesive, for example. Examples of solvents include aromatic hydrocarbons such as benzene, toluene and xylene, ketones such as acetone, MEK (methyl ethyl ketone) and methylene isobutylene ketone, esters such as methyl acetate, ethyl acetate and butyl acetate, diethylene ether, THF , Ethers such as dioxane, and mixtures thereof.

  The pickup roll 122 picks up the lower layer side adhesive composition 121 from the coater pan 121 a and conveys it to the applicator roll 123. The applicator roll 123 forms the lower layer side adhesive layer 41 on the metal plate 20 by applying the lower layer side adhesive composition 121 to one surface of the metal plate 20. The backup roll 124 contacts the other surface of the metal plate 20 and sandwiches the metal plate 20 together with the applicator roll 123. Then, the backup roll 124 conveys the metal plate 20 to the first oven 130.

  The first oven 130 heats the metal plate 20 to bring the lower-layer adhesive layer 41 into close contact with the metal plate 20. Here, the heating temperature of the metal plate 20 is not particularly limited as long as it is a temperature at which the lower layer side adhesive layer 41 is in close contact with the metal plate 20, that is, a temperature at which the lower layer side adhesive exhibits an anchor effect on the metal plate 20.

  For example, when the lower layer side adhesive composition does not contain a solvent, the heating temperature may be higher than 180 ° C. In this case, even if the softening temperature of the lower layer side adhesive is high, the lower layer side adhesive can be sufficiently softened. As a result, the lower layer side adhesive penetrates deep into the unevenness of the metal plate 20 and can exhibit a strong anchor effect.

  On the other hand, when the lower layer side adhesive layer 41 contains a solvent, the heating temperature may be a temperature at which the solvent evaporates. This is because by heating the metal plate 20 at such a heating temperature, the lower layer side adhesive penetrates deep into the unevenness of the metal plate 20 and can exhibit a strong anchor effect. In this case, since heating temperature becomes lower, it is preferable. In the manufacturing apparatus 100, the solvent is removed from the lower layer side adhesive layer 41 before the upper layer side adhesive layer 42 is formed by the second roll coater 140. Therefore, it is possible to prevent the components of the lower layer side adhesive layer from entering the upper layer side adhesive layer 42 when the upper layer side adhesive layer 42 is produced.

  The second roll coater 140 is a device for laminating the upper layer side adhesive layer 42 on the lower layer side adhesive layer 41, and includes a coater pan (pot) 141a, a pickup roll 142, a transport roll 143, and an applicator roll 144. .

  The coater pan 141a is an apparatus for storing the upper layer side adhesive composition 141 including the upper layer side adhesive. The upper layer side adhesive composition 141 may contain a solvent in addition to the upper layer side adhesive, and may further contain an additive constituting the upper layer side adhesive layer 42. Here, the solvent is used for the purpose of adjusting the viscosity of the upper layer side adhesive. As an example of a solvent, the example similar to the solvent of the lower layer side adhesive composition 121 mentioned above is mentioned.

  The pick-up roll 142 picks up the upper layer side adhesive composition 141 from the coater pan 141 a and conveys it to the transport roll 143. The conveyance roll 143 conveys the upper layer side adhesive composition 141 to the applicator roll 144. Note that the transport roll 143 may be omitted. In the example of FIG. 4, the transport roll 143 is omitted. The applicator roll 144 forms the upper layer side adhesive layer 42 on the lower layer side adhesive layer 41 by applying the upper layer side adhesive composition 141 on the lower layer side adhesive layer 41.

  The second oven 150 softens the upper-layer adhesive by heating the metal plate 20 to a heating temperature of 180 ° C. or lower. Thus, in this embodiment, the heating temperature of the metal plate 20 is lowered. However, since the softening temperature of the upper layer side adhesive is low as described above, the upper layer side adhesive is sufficiently softened even at such a heating temperature. Moreover, since the low temperature upper side adhesive layer 42 can be pressure-bonded to the design film 30, the heat conducted to the design film 30 can be reduced. Therefore, deterioration of the design applied to the design film 30 can be suppressed. In addition, the heating temperature of the metal plate 20 can be further lowered according to the softening temperature of the upper layer side adhesive. For example, when the softening temperature of the upper layer side adhesive is 70 ° C. or lower, the heating temperature of the metal plate 20 is preferably 165 ° C. or lower, and more preferably 140 ° C. or lower. When the softening temperature of the upper layer side adhesive is 70 ° C. or lower, the upper layer side adhesive is sufficiently softened even if the heating temperature is within the above range. That is, the design film 30 can be sufficiently adhered to the metal plate 20. Therefore, the design film 30 can be sufficiently adhered to the metal plate 20 while suppressing deterioration of the design applied to the design film 30. The lower limit of the heating temperature of the metal plate 20 may be the softening temperature of the upper layer side adhesive −40 ° C. When the heating temperature of the metal plate 20 falls below the temperature, the upper layer side adhesive may not sufficiently soften in a short time when the design film is laminated, and the primary adhesion may be reduced.

  The design film transport device 160 is a device that transports the design film 30 to the pressure-bonding roll pair 163. The design film transport device 160 includes a design film roll 161 and a plurality of transport rolls 162. The design film roll 161 is a roll around which a long design film 30 is wound. The transport roll 162 pulls the design film 30 from the design film roll 161 and transports the design film 30 to the crimping roll pair 163. The pressure-bonding roll pair 163 presses the design film 30 to the upper-layer adhesive layer 42. Thereby, the design metal plate 10 is produced. The cooling device 170 is a water cooling tank, for example, and cools the design metal plate 10.

(2-2. Second example)
The second example of the manufacturing method is realized by using, for example, the manufacturing apparatus 101 shown in FIG. Therefore, the configuration of the manufacturing apparatus 101 will be described. Here, the manufacturing apparatus 101 has the same configuration as the manufacturing apparatus 100 described above except that the installation positions of the second roll coater 140 and the second oven 150 are different. Therefore, differences from the manufacturing apparatus 100 will be described.

  The second roll coater 140 and the second oven 150 are provided in the design film transport device 160. The applicator roll 144 of the second roll coater 140 forms the upper layer side adhesive layer 42 on the design film 30 by applying the upper layer side adhesive composition 141 to the design film 30.

  The second oven 150 heats the design film 30 so that the upper-side adhesive layer 42 is in close contact with the design film 30. Here, the heating temperature of the design film 30 is not particularly limited as long as it is a temperature at which the upper layer side adhesive layer 42 is in close contact with the design film 30, that is, a temperature at which the upper layer side adhesive exhibits an anchor effect on the design film 30. For example, the heating temperature of the design film 30 may be 180 ° C. or less.

  The pressure-bonding roll pair 163 presses the upper layer side adhesive layer 42 on the design film 30 to the lower layer side adhesive layer 41 on the metal plate 20 in a state where the temperature of the metal plate 20 is 180 ° C. or lower. That is, the crimping roll pair 163 makes the design metal plate 10 by bonding the lower layer side adhesive layer 41 and the upper layer side adhesive layer 42 together. As described above, since the softening temperature of the upper layer side adhesive is low, the upper layer side adhesive is sufficiently softened even when the temperature of the metal plate 20 is 180 ° C. or lower. Moreover, since the low temperature upper side adhesive layer 42 can be pressure-bonded to the design film 30, the heat conducted to the design film 30 can be reduced. Therefore, deterioration of the design applied to the design film 30 can be suppressed.

  The temperature of the metal plate 20 can be further lowered according to the softening temperature of the upper layer side adhesive. For example, when the softening temperature of the upper layer side adhesive is 70 ° C. or lower, the temperature of the metal plate 20 is preferably 165 ° C. or lower, and more preferably 140 ° C. or lower. When the softening temperature of the upper layer side adhesive is 70 ° C. or lower, the upper layer side adhesive is sufficiently softened even if the temperature of the metal plate 20 is within the above range. The lower limit of the heating temperature of the metal plate 20 may be the softening temperature of the upper layer side adhesive −40 ° C. The method for setting the temperature of the metal plate 20 to 180 ° C. or lower is not particularly limited. For example, when the metal plate 20 is heated to over 180 ° C. in the first oven 130, the temperature of the metal plate 20 may be set to 180 ° C. or less by adjusting the distance between the first oven 130 and the pressure-bonding roll pair 163. it can. That is, the temperature of the metal plate 20 may be 180 ° C. or lower due to the residual heat of the first oven 130. A cooling device similar to the cooling device 170 may be installed between the first oven 130 and the pressure-bonding roll pair 163. When the heating temperature of the metal plate 20 by the first oven 130 is 180 ° C. or less, a separate oven may be installed between the first oven 130 and the pressure-bonding roll pair 163. The metal plate 20 is reheated to a temperature of 180 ° C. or lower by this oven. Further, the temperature of the metal plate 20 may be set to 180 ° C. or less by the residual heat of the second oven 150, that is, the residual heat given from the design film 30 on which the upper-layer adhesive layer 42 is laminated.

  Here, the design film 30 on which the upper layer side adhesive layer 42 is laminated, that is, a laminated film is prepared in advance, and the upper layer side adhesive layer 42 of the laminated film is brought into close contact with the lower layer side adhesive layer 41 on the metal plate 20. Also good. Alternatively, the metal plate 20 on which the lower-layer side adhesive layer 41 is laminated, that is, a laminated metal plate, is prepared in advance and is brought into close contact with a prepared laminated film (or a laminated film produced by the manufacturing apparatus 101). Good.

  In the manufacturing apparatuses 100 and 101 according to the first and second examples, the bonding interface when the design film 30 is pressure-bonded to the metal plate 20 is the upper layer side adhesive layer 42 / design film 30, the upper layer side adhesive layer 42 /. It becomes the lower layer side adhesive layer 41. Therefore, the manufacturing apparatuses 100 and 101 perform organic / organic bonding. Organic substances are easily deformed even at a heating temperature of 180 ° C. or less, and a sufficient anchor effect is easily exhibited. Therefore, also in this point, the design film 30 and the metal plate 20 can be firmly adhered.

<1. Adjustment of adhesive composition>
(1-1. Common process)
An adhesive composition was prepared by the following steps. First, 200 parts by mass of a high-boiling naphtha (Solvesso 150) was put into a flask equipped with a stirring rod and a reflux condenser, and stirred for about 10 minutes. Thereafter, 100 parts by mass of an adhesive main agent (any one of polyester, acrylic, and urethane) was added and stirred and dissolved at room temperature for 4 hours. Here, the adhesive main agent constitutes the above-described upper layer side adhesive or lower layer side adhesive. After confirming that the adhesive main agent was completely dissolved, 20 parts by mass of MEK (methyl ethyl ketone, manufactured by Maruzen Petroleum Co., Ltd.) was added and stirred at room temperature for 30 minutes. The adhesive composition was produced by the above process.

(1-2. Preparation of curable adhesive composition)
By adding a curing agent solution (Y6410-B manufactured by Yokohama Rubber Co., Ltd. or Desmodule RFE manufactured by Bayer Co., Ltd.) and a catalyst (U-CAT SA102 manufactured by San Apro Co., Ltd.) to the above adhesive composition, a curable adhesive is prepared. A composition was obtained. Here, Y6410-B is a polyisocyanate resin having 30 mol% of isocyanate groups with respect to all dicarboxylic acid residues. Here, the input amount of the curing agent solution was 4 parts by mass in solid content, and the input amount of the catalyst was 0.1 mass part in solid content.

(1-3. Production of Adhesive Composition Containing Silane Coupling Agent and Filler)
In a flask equipped with a stirrer and a reflux condenser, 200 parts by mass of high-boiling naphtha (Solvesso 150) and 2.5 parts by mass of fine silica (Aloezil R-972) as a filler were added and stirred for about 10 minutes. Thereafter, 100 parts by mass of an adhesive main agent (any one of polyester, acrylic, and urethane) was added and stirred and dissolved at room temperature for 4 hours. After confirming that the adhesive main agent was completely dissolved, a silane compound (KBM-402 manufactured by Shin-Etsu Chemical Co., Ltd.) and a catalyst were added as a silane coupling agent, and the mixture was stirred at room temperature for 1 hour. Finally, 20 parts by mass of MEK (methyl ethyl ketone, manufactured by Maruzen Petroleum Corporation) was added and stirred at room temperature for 30 minutes. The adhesive composition was obtained by the above process. The composition of the adhesive composition is shown in Tables 1-3.

  The numerical value of Tables 1-3 means a mass part except softening temperature. Moreover, the mass part of a hardening | curing agent solution and a catalyst means the mass part of solid content. Table 4 shows specific contents of materials constituting each adhesive composition.

<2. Measurement of softening temperature>
By the following method, the softening temperature of each adhesive composition, specifically, the softening temperature of the adhesive main component constituting the adhesive composition was measured. First, the adhesive composition was gently poured into a PE (polyethylene) container having a diameter of 7.5 cm and a thickness of about 1 cm. Subsequently, the thickness of the adhesive composition was made uniform in the container by gently tilting the container. Next, an adhesive film was prepared by keeping the container horizontal and drying it in a constant temperature room at 20 ° C. for 1 to 3 days. Subsequently, the adhesive film was gently peeled from the container. In addition, the softening temperature was measured using the adhesive composition before adding a hardening | curing agent and a catalyst as an adhesive composition.

  Subsequently, the softening temperature was measured using a thermomechanical analyzer. Specifically, a cylindrical needle having a diameter of 1 mm was pushed into the sample with a load of 500 mN while heating the adhesive film at 2 ° C./min. And the temperature when the penetration | invasion depth of the cylindrical needle | hook into an adhesive film satisfy | fills said Numerical formula (1) was made into softening temperature. The softening temperature of each adhesive composition is summarized in Tables 1 to 3.

<3. Production of design film>
A design film was prepared or produced by the following steps.
(3-1. Vinyl chloride film)
(3-1-1. Single color embossed film)
As a monochromatic embossed film made of vinyl chloride, LE301 made by Okamoto Co. was prepared. The film thickness is 150 μm. The embossed film has a surface embossed pattern having a depth of 15 μm.

(3-1-2. High-definition film)
An original film having a thickness of 120 μm was produced by forming the resin composition used in producing the monochromatic film by a calendering method. Here, by using a mirror roll as a roll used in the calendar method, a mirror finished raw film was produced. Then, using a continuous laminator, a polyester adhesive (S-580X manufactured by Sekisui Fuller Co., Ltd.) was applied to the raw film and dried at 80 ° C. After drying, a 25 μm-thick biaxially stretched PET (polyethylene terephthalate) film that had been subjected to wood grain printing on the adhesive coating surface of the original fabric film was laminated so that the printed surface and the adhesive were in contact with each other. A high-definition film was obtained by the above process.

(3-2. Polyester film)
Using a two-layer T-die, a monochromatic film and a raw film made of a PET-based alloy containing a white pigment (20% by mass) were obtained. All the films had a thickness of 100 μm. For monochromatic films, embossing rolls are used to make the above 3-1-1. The embossed pattern was applied to make a single color embossed film. In addition, a mirror roll was used for the raw film, and a mirror finish was used. Furthermore, the above 3-1-2. By carrying out the same doubling process as above, a 25 μm-thick biaxially stretched PET film subjected to wood grain printing was laminated on the original film. By this step, a high-definition film was obtained. Here, the PET-based alloy is a PET (Unitika MA1344), a polyolefin-based elastomer (Mitsui Chemicals, Toughmer 4085S), an ethylene terpolymer (Sumitomo Chemical Co., Ltd., Bondfast 7L) 87/10 / 3 is a mixed alloy.

(3-3. Polyolefin film)
Using a two-layer T dice, an upper layer: PP (polypropylene, manufactured by Nippon Polypro Co., Ltd., Novalex FB3B), a lower layer: maleic anhydride-modified PP (Mitsui Chemicals Co., Ltd., Admer SF725) (upper layer / Lower layer = 90/10 μm) was produced. Using this two-layer PP film, a monochromatic embossed film and a mirror finished polyolefin raw material were obtained. Here, the monochromatic embossed film includes the above 3-1-1. A similar embossed pattern was applied. Furthermore, the above 3-1-2. By carrying out the same doubling process as above, a 25 μm-thick biaxially stretched PET film subjected to wood grain printing was laminated on the original film. By this step, a high-definition film was obtained.

(3-4. Other films)
Monochromatic films of 40 μm thick PVD film (Tedlar, manufactured by DuPont) and PMMA (100 μm thick, manufactured by Kyowa Leather Co., Ltd.) were prepared as the fluorine resin film and acrylic resin film. The above 3-1-1. A single color embossed film was produced by applying the same embossed pattern as in FIG.

  In addition, when the softening temperature of each said design film was measured, it has confirmed that all were less than 150 degreeC. Specifically, the softening temperature of the vinyl chloride film is 140 ° C., the softening temperature of the polyester film is 135 ° C., the softening temperature of the polyolefin film is 90 ° C., the softening temperature of the PVD film is 80 ° C., and the softening temperature of the PMMA film is 140 ° C. Met.

<4. Metal plate>
As the metal plate, two types of zinc-based gold steel plates having a thickness of 0.45 mm (Nippon Steel & Sumikin Superdimer (K08) (hereinafter also referred to as “SD steel plate”), GI steel plate (Z18)), Al plate (A5052, 1 .2 mm thickness). And after performing an alkali degreasing process to these metal plates, the chromate liquid was apply | coated and the chromate film | membrane of about 45 mg / m < ² > was formed on the metal plate surface. Further, as other metal plates, a roughened Cu plate (70 μm, electrolytic copper foil plate) and a JISH4600 standard Ti plate (1 mm thickness) subjected to vacuum annealing pickling finish were prepared.

<5. Fabrication of design metal plate>
(5-1. Examples 1-37)
The design metal plate which concerns on Examples 1-37 was produced by the following processes. First, a lower layer adhesive composition (lower layer side adhesive layer composition) was applied to a metal plate with a coater so as to have a thickness of 2 μm. Then, the metal plate was heated to the lower layer heating temperature (detailed values are shown in the table described later). Thereby, the lower layer side adhesive layer was formed on the metal plate. After the metal plate was cooled to room temperature, the upper layer adhesive composition (upper layer side adhesive composition) was applied on the lower layer side adhesive layer so as to have a thickness of 2 μm. Then, the upper adhesive layer was formed by heating the metal plate to the upper layer heating temperature (detailed values are shown in the table described later). After the temperature of the metal plate reached the upper layer heating temperature, the above-described vinyl chloride film (either a single color embossed film or a high definition film) was pressure-bonded to the surface of the upper layer side adhesive layer. The designed metal plate was obtained by the above process. The heating temperature of the metal plate was measured using a thermocouple previously attached to the surface of the metal plate. In Examples 1 to 11, a polyester-based adhesive composition was used as an upper layer adhesive composition and a lower layer adhesive composition. In Examples 12 to 18, an acrylic adhesive composition was used as the adhesive composition for the upper layer and the adhesive composition for the lower layer. In Examples 19 to 37, adhesive compositions of different materials were used as the adhesive composition for the upper layer and the adhesive composition for the lower layer. A different metal plate was used for each example. In the following description, the design metal plate to which the monochromatic embossed film is attached is also referred to as “monochromatic embossed plate”, and the design metal plate to which the high definition film is attached is also referred to as “high definition plate”.

(5-2. Examples 38 to 41)
The design metal plate was produced by performing the same process as Example 1 except having changed the kind of design film.

(5-3. Example 42)
The design metal plate according to Example 42 was produced by the following steps. First, an adhesive composition for a lower layer was applied to a metal plate with a coater so as to have a thickness of 2 μm. The metal plate was then heated to the lower layer heating temperature. Thereby, the lower layer side adhesive layer was formed on the metal plate. Subsequently, the metal plate was cooled to room temperature. On the other hand, the adhesive composition for the upper layer was applied on the above-described vinyl chloride film with a coater so as to have a thickness of 2 μm. Subsequently, the design film was heated to the upper layer heating temperature. As a result, an upper adhesive layer was formed on the vinyl chloride film. Thereafter, the design film was cooled to room temperature. Next, the metal plate on which the lower layer side adhesive layer was formed was heated to the upper layer heating temperature, and the upper layer side adhesive layer on the design film was pressure bonded to the lower layer side adhesive layer on the metal plate. The designed metal plate was obtained by the above process.

(5-4. Comparative Examples 1 to 13)
A design metal plate was produced by the same process as in Example 1 except that the adhesive layer was composed of only one layer. That is, an adhesive layer was formed on the metal plate by the same process as in Example 1. Next, the metal plate was heated to a heating temperature (detailed values are shown in a table described later). Subsequently, the vinyl chloride film was pressure-bonded to the adhesive layer. The design metal plate was produced according to the above process.

(5-5. Comparative Examples 14 to 17)
A design metal plate was produced in the same manner as in Example 1 except that the softening temperature of the upper layer side adhesive was higher than the softening temperature of the lower layer side adhesive.

(5-6. Comparative Example 18)
A design metal plate was produced in the same manner as in Example 1 except that the softening temperature of the lower layer side adhesive was lower than 90 ° C.

(5-7. Comparative Example 19)
A design metal plate was produced in the same manner as in Example 1 except that the softening temperature of the upper layer side adhesive was higher than 80 ° C.

(5-8. Comparative Examples 20 to 27)
The design metal plate was produced by performing the process similar to the comparative example 1 except having changed the kind of design film. The structure of the design metal plate produced by each Example and the comparative example is collectively shown in Tables 5-15.

<6. Evaluation of design metal plate>
(6-1. Initial adhesion)
Initial adhesion was evaluated using a single color embossed plate. Specifically, a # -type cut having a width of 5 mm was made in a monochromatic embossed film with a cutter knife. Here, the depth of the cut was set to a depth that reached the metal plate. Then, using an Erichsen testing machine (DKSH, Erichsen testing machine), the # -type cut portion was overlaid by 8 mm. Here, the center (top portion) of the overhang portion was made to coincide with the center of the # -shaped cut portion. Next, the # -type cut portion was forcibly peeled with tweezers, and the degree of peeling was evaluated according to the following criteria.
A: Rating 5 (the film is coherently broken and almost no peeling)
A: Grade 4 (only the top part is peeled off)
○: Score 3 (the whole top part and less than 1/3 of the side part are peeled)
X: Rating 2 (the whole top part and the whole side part are peeled off)
XX: Score 1 (the entire top part, the entire side processed part, and the periphery of the # cut part are peeled off)
And the same test was repeated 5 times. The results are summarized in Tables 5-15. In addition, when there was a variation in evaluation for each test, the upper and lower limits of the evaluation are listed in the table.

(6-2. Emboss return rate)
Using a single color embossed plate, the emboss return rate, which is one of the evaluation indexes for initial design retainability, was evaluated. Specifically, the arithmetic average roughness Ra1 of the monochromatic embossed film surface and the arithmetic average roughness Ra2 of the monochromatic embossed plate surface (specifically, the surface of the monochromatic embossed film attached to the monochromatic embossed plate) are contact types. It was measured with a two-dimensional roughness meter (OLS400, manufactured by Olympus). The observation surface was 20 × 20 mm. Next, an emboss return rate, which is one of the indexes of initial design retainability, was calculated by the following formula (2).
Emboss return rate χ: χ = 1−Ra2 / Ra1 (2)

(6-3. Vividness and discoloration)
Using the high definition film, the definition (PDG value) and color fading, which are one of the evaluation indexes of initial design retention, were evaluated. Specifically, the visibility of the high-definition film surface and the high-definition plate surface (specifically, the surface of the high-definition film affixed to the high-definition plate surface) (Measured by PGD-IV manufactured by Nippon Color Research Institute). And the visibility was evaluated according to the following criteria.
A: Difference in sharpness of high-definition film and high-definition plate is less than 0.1 ○: Difference in sharpness of high-definition film and high-definition plate is 0.1 to 0.2
X: Difference in sharpness of high-definition film and high-definition plate is 0.3 or more And the same test was repeated 5 times. The results are summarized in Tables 5-15. In addition, when there was a variation in evaluation for each test, the upper and lower limits of the evaluation are listed in the table.

Furthermore, the a value of the high-definition film surface and the high-definition plate surface was measured with a color difference meter (CM-2600d manufactured by Konica Minolta). Here, the a value is a value for evaluating redness. Since redness tends to disappear particularly during the production of the designed metal plate, the color fading was evaluated using the a value. Then, a difference Δa (= a value of high-definition film-a value of high-definition film) was calculated, and color fading was evaluated according to the following criteria.
: Δa <3.0
○: 3.0 <Δa <5.0
×: Δa> 5.0
And the same test was repeated 5 times. The results are summarized in Tables 5-15. In addition, when there was a variation in evaluation for each test, the upper and lower limits of the evaluation are listed in the table.

(6-4. Durability)
Durability was evaluated using a single color embossed plate. Specifically, the monochromatic embossed plate was immersed in boiling water and 75 ° C. warm water for 20 days. In addition, when the softening temperature of the lower layer side adhesive was less than 100 ° C., except for Example 6, it was immersed only in 70 ° C. warm water. Hereinafter, such a test is also referred to as an “immersion test”. Subsequently, the film adhesion after the immersion test was evaluated by a test similar to the initial adhesion described above. Furthermore, the edge part of the monochromatic embossed board after an immersion test was observed visually, and the presence or absence of the return (peeling) of a monochromatic embossed film and the presence or absence of corrosion were evaluated. In addition, the presence or absence of corrosion was performed only about the metal plate in which corrosion becomes a problem, ie, GI steel plate and SD steel plate. And the same test was repeated 5 times. The results are summarized in Tables 5-15. In addition, when there was a variation in evaluation for each test, the upper and lower limits of the evaluation are listed in the table.

<7. Consideration of evaluation results>
In Examples 1 to 43, high evaluations were obtained for all of the initial adhesion, initial design retainability, and durability. In Examples 1-43, since the softening temperature of the upper layer side adhesive is 80 ° C. or lower, the design film is sufficient even if the upper layer heating temperature is low (specifically, 180 ° C. or lower). Can be closely attached to the metal plate. Therefore, both initial adhesion strength and initial design retainability increased. Furthermore, since the softening temperature of the lower layer side adhesive is 90 ° C. or higher, even if the design metal plate is exposed for a long time in a hot and humid environment, water molecules on the metal plate / lower layer side adhesive layer interface Intrusion can be prevented. Therefore, durability became high.

  Furthermore, in Example 1, the softening temperature of the upper layer side adhesive is higher than 70 ° C., but in Examples 2 to 11, the softening temperature of the upper layer side adhesive is 70 ° C. or lower. And the initial design retainability of Examples 2-11 was superior to the initial design retainability of Example 1. In Examples 2 to 11, since the softening temperature of the upper layer side adhesive is 70 ° C. or lower, the upper layer heating temperature can be lower than that of Example 1 (specifically, 165 ° C. or lower). As a result, excellent initial design retainability was obtained. In addition, according to Examples 4 and 6, it turned out that initial stage design retainability becomes still higher by making upper layer heating temperature into 140 degrees C or less.

  Furthermore, when the softening temperature of the lower layer side adhesive was 100 ° C. or higher, it was possible to maintain a strong adhesive force including the end portion even under extremely severe high temperature and high humidity such as immersion in boiling water. That is, extremely high durability could be obtained.

  Furthermore, it has been found that the above effect can be obtained more significantly when the difference between the softening temperature of the lower layer side adhesive and the softening temperature of the upper layer side adhesive is 30 ° C. or higher.

  Furthermore, when Example 7 was compared with Examples 1-6, in Example 7, durability became higher. Similarly, when Example 16 and Examples 12-15 were compared, in Example 16, durability became higher. In Examples 7 and 16, the silane coupling agent is added to the lower layer side adhesive composition in an amount of 2 to 15 parts by mass with respect to 100 parts by mass of the lower layer side adhesive. For this reason, in Examples 7 and 16, the adhesion of the metal plate / lower-layer-side adhesive layer is further strengthened. Therefore, even under extremely severe high temperature and high humidity, it was possible to maintain a strong adhesion including the edges.

  On the other hand, in Comparative Examples 1 to 4, 7 to 10, and 12 to 13, the adhesive layer is a single layer, and the softening temperature of the adhesive is 80 ° C. or lower. For this reason, even if heating temperature was low temperature (180 degrees C or less), the design film was fully stuck to the metal plate. However, the adhesion was significantly reduced after the immersion test. This is because the softening temperature of the adhesive is low. That is, since the softening temperature of the adhesive is low, it is considered that water molecules entered the interface of the metal plate / lower layer adhesive layer from the end of the design metal plate during the immersion test, and the adhesion force was reduced by the water molecules. . For this reason, the other durability tests were not performed in Comparative Examples 1-4, 7-10, and 12-13. In addition, when the design film can be closely attached to the metal plate at a low temperature, the initial design retainability is also increased, and thus the test for the initial design retainability was not performed.

  In Comparative Examples 5, 6, and 11, the adhesive layer is a single layer, and the softening temperature of the adhesive is 90 ° C. or higher. For this reason, when the heating temperature was 180 ° C. or lower, the design film and the metal plate could not be sufficiently adhered. In a specific example, the initial adhesion was significantly reduced. On the other hand, when the heating temperature was higher than 180 ° C., the design film and the metal plate could be sufficiently adhered. However, since the design film was exposed to a high temperature, the initial design retainability was significantly reduced. In Comparative Examples 20 to 27 having different types of design films, the same results as in Comparative Examples 1 to 13 were obtained. In addition, when the design film was an acrylic film, the durability was particularly deteriorated. It is thought that the acrylic film is easy to permeate water molecules.

  In Comparative Examples 14 to 17, since the softening temperature of the upper layer side adhesive is 90 ° C. or higher, the design film is sufficiently adhered to the metal plate unless the upper layer heating temperature is increased (greater than 180 ° C.). I couldn't. As a result, the initial design retention was significantly reduced. Furthermore, corrosion occurred at the end of the designed metal plate by the immersion test. Since the softening temperature of the lower layer side adhesive is 80 ° C. or lower, water molecules enter the interface of the metal plate / lower layer side adhesive layer from the end of the design metal plate during the immersion test, and the metal plate It is thought that it was corroded. In Comparative Examples 14 to 17, since corrosion occurred at the end, film peeling was not evaluated.

  In Comparative Example 18, the softening temperature of the lower layer side adhesive is higher than the softening temperature of the upper layer side adhesive, and the softening temperature of the upper layer side adhesive is 80 ° C. or lower. For this reason, even if heating temperature was low temperature (180 degrees C or less), the design film was fully stuck to the metal plate. However, the softening temperature of the lower layer side adhesive is less than 90 ° C. And the adhesive force fell remarkably by the immersion test. Since the softening temperature of the lower layer side adhesive is less than 90 ° C., it is considered that water molecules entered the interface between the metal plate and the lower layer side adhesive layer during the immersion test, and the adhesion force was reduced by the water molecules.

  In Comparative Example 19, the softening temperature of the lower layer side adhesive is higher than the softening temperature of the upper layer side adhesive. However, since the softening temperature of the upper layer side adhesive is higher than 80 ° C., the design film cannot be sufficiently adhered to the metal plate unless the upper layer heating temperature is increased (greater than 180 ° C.). As a result, the initial design retention was significantly reduced.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Design metal plate 20 Steel plate 30 Design film 40 Adhesive layer 41 Lower layer side adhesive layer 42 Upper layer side adhesive layer 100, 101 Design metal plate manufacturing apparatus 120 First roll coater 130 First oven 140 Second roll coater 150 Second oven 160 Design film transport device 170 Cooling device

Claims (21)

A metal plate,
A lower-side adhesive layer laminated on the metal plate;
An upper adhesive layer laminated on the lower adhesive layer;
A design film laminated on the upper layer side adhesive layer,
The lower layer side adhesive layer includes a lower layer side adhesive,
The upper layer side adhesive layer includes an upper layer side adhesive,
The softening temperature of the upper layer side adhesive is 80 ° C. or less,
The design metal plate, wherein the lower layer side adhesive has a softening temperature of 90 ° C or higher.   The design metal plate according to claim 1, wherein a softening temperature of the upper layer side adhesive is 70 ° C or lower.   The design metal plate according to claim 1 or 2, wherein the softening temperature of the lower layer side adhesive is 100 ° C or higher.   The lower layer side adhesive and the upper layer side adhesive are composed of any one or more of polyester-based, acrylic-based, urethane-based, epoxy-based, and urea-based thermosetting adhesives. The design metal plate according to any one of claims 1 to 3.   The lower layer side adhesive and the upper layer side adhesive are polyester systems in which 3 to 25 parts by mass of a polyisocyanate resin having an isocyanate group of 30 mol% or more based on the total dicarboxylic acid residue is added to 100 parts by mass of a linear polyester resin. It is a thermosetting adhesive, The design metal plate of any one of Claims 1-4 characterized by the above-mentioned.   The said lower layer side adhesive layer contains 2-15 mass parts of silane coupling agents with respect to 100 mass parts of said lower layer side adhesive agents, The design metal of any one of Claims 1-5 characterized by the above-mentioned. Board.   The said design film is comprised by any 1 or more types among a vinyl chloride resin, a polyester resin, an acrylic resin, polyolefin resin, and a fluorine resin, The any one of Claims 1-6 characterized by the above-mentioned. The described design metal plate.   The design metal plate according to any one of claims 1 to 7, wherein a softening temperature of a portion of the design film that is in contact with the upper adhesive layer is less than 150 ° C. It is a manufacturing method of the design metal plate which manufactures the design metal plate of any 1 paragraph of Claims 1-8,
A method for producing a design metal plate, comprising: bonding the metal plate at 180 ° C. or less and the design film via the lower layer side adhesive layer and the upper layer side adhesive layer. Laminating the lower layer side adhesive on the metal plate, forming a lower layer side adhesive layer on the metal plate,
Heating the metal plate to bring the lower adhesive layer into close contact with the metal plate;
Laminating an upper layer side adhesive on the lower layer side adhesive layer, thereby forming an upper layer side adhesive layer on the lower layer side adhesive layer;
A step of softening the upper layer side adhesive by heating the metal plate to a heating temperature of 180 ° C. or less;
Laminating a design film on the upper layer side adhesive layer,
The softening temperature of the upper layer side adhesive is 80 ° C. or less,
A softening temperature of the lower layer side adhesive is 90 ° C. or higher. Laminating the lower layer side adhesive on the metal plate, forming a lower layer side adhesive layer on the metal plate,
Heating the metal plate to bring the lower adhesive layer into close contact with the metal plate;
A step of preparing a laminated film in which an upper adhesive layer containing an upper adhesive is laminated on a design film;
Bonding the lower adhesive layer on the metal plate and the upper adhesive layer on the design film in a state where the temperature of the metal plate is 180 ° C. or less,
The softening temperature of the upper layer side adhesive is 80 ° C. or less,
A softening temperature of the lower layer side adhesive is 90 ° C. or higher. The step of preparing the laminated film includes
Laminating the upper layer side adhesive on the design film to form an upper layer side adhesive layer on the design film;
The method for producing a design metal plate according to claim 11, further comprising: heating the design film to bring the upper adhesive layer into close contact with the design film. By laminating the lower layer side adhesive composition containing the lower layer side adhesive and the solvent on the metal plate, the lower layer side adhesive layer is formed,
The said metal plate is heated, The said solvent contained in the said lower layer side adhesive layer is evaporated, The said lower layer side adhesive layer is closely_contact | adhered to the said metal plate, The any one of Claims 10-12 characterized by the above-mentioned. The manufacturing method of the design metal plate of 1 item | term.   The design metal plate according to any one of claims 10 to 12, wherein the lower side adhesive layer is brought into close contact with the metal plate by heating the metal plate to a heating temperature exceeding 180 ° C. Manufacturing method.   The method for producing a design metal plate according to any one of claims 10 to 14, wherein a softening temperature of the upper layer side adhesive is 70 ° C or lower.   The softening temperature of the said lower layer side adhesive agent is 100 degreeC or more, The manufacturing method of the design metal plate of any one of Claims 10-15 characterized by the above-mentioned.   The lower layer side adhesive and the upper layer side adhesive are composed of any one or more of polyester-based, acrylic-based, urethane-based, epoxy-based, and urea-based thermosetting adhesives. The manufacturing method of the design metal plate of any one of Claims 10-16.   The lower layer side adhesive and the upper layer side adhesive are polyester systems in which 3 to 25 parts by mass of a polyisocyanate resin having an isocyanate group of 30 mol% or more based on the total dicarboxylic acid residue is added to 100 parts by mass of a linear polyester resin. It is a thermosetting type adhesive agent, The manufacturing method of the design metal plate of any one of Claims 10-17 characterized by the above-mentioned. By laminating the lower layer side adhesive composition containing the lower layer side adhesive and the silane coupling agent on the metal plate, the lower layer side adhesive layer is formed,
The said silane coupling agent is contained in the said lower layer side adhesive composition in the ratio of 2-15 mass parts with respect to 100 mass parts of said lower layer side adhesives, The any one of Claims 10-18 characterized by the above-mentioned. The manufacturing method of the design metal plate of 1 item | term.   The said design film is comprised by any 1 or more types among a vinyl chloride resin, a polyester resin, an acrylic resin, a polyolefin resin, and a fluorine resin, The any one of Claims 10-19 characterized by the above-mentioned. The manufacturing method of the design metal plate of description. 21. The method for producing a design metal plate according to claim 10, wherein a softening temperature of a portion of the design film that is in contact with the upper adhesive layer is less than 150 ° C.

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