JP6921626B2 - Resin laminated metal plate and its manufacturing method - Google Patents

Description

The present invention relates to, for example, a resin laminated metal plate used for metal containers, electric appliances, or building material applications, and a method for manufacturing the same.

In recent years, metal plates laminated with a resin film with a design on the surface have been used for interior and exterior of various buildings (for example, interior and exterior walls of houses, doors, roofs, partitions, etc.), furniture parts, housings for home appliances, and truck racks. It is increasingly used for furniture, vehicle interior / exterior, ship interior / exterior, road protection walls, and metal containers.

These resin laminated metal plates are often manufactured by the following steps. That is, first, an adhesive layer is formed on the metal plate or the resin film by laminating (for example, coating) the adhesive on the metal plate or the resin film (adhesive laminating step). Here, the adhesive may be laminated on a metal plate or a resin film in a state of being dissolved in a solvent or dispersed in the solvent. Then, the metal plate is heated to soften the adhesive. If the adhesive layer contains a solvent, the solvent evaporates due to heating. Then, the resin film is pressure-bonded (laminated) to the metal plate (resin film laminating step).

Regarding the design, when embossing or printing pattern is given to the resin film before laminating the resin film on the metal plate, and the resin film with the design is laminated on the metal plate to be imparted to the resin laminated metal plate (hereinafter, this). The method is referred to as a pre-design giving method), and there are both cases where the design is given to the resin laminated metal plate by embossing, printing, and baking on the surface of the resin film after laminating the resin film on the metal plate (hereinafter,). , This method is called the post-design granting method). When a resin laminated metal plate is processed and molded as in a metal container, the design changes depending on the processing, so that the design is often applied to the resin laminated metal plate by a post-design imparting method. That is, the design is given to the resin film after the resin laminated metal plate is molded. Further, even when a high-class design such as a silk printing pattern or a three-dimensional printing pattern is given to the resin laminated metal plate, heat transfer from the metal plate to the resin film when laminating the resin film on the metal plate is performed. In order to prevent the design on the resin film from changing, the design is often given to the resin laminated metal plate by the post-design giving method.

By the way, as an adhesive for this resin laminated metal plate, an adhesive using polyester as a main resin and isocyanate as a curing agent is generally used. However, when a conventional adhesive is used, it is necessary to heat the adhesive layer to a high temperature to laminate the resin film in order to exhibit the anchor effect at the resin film / adhesive interface and secure the adhesive force. .. As a result, in the pre-design imparting method, there are problems that the heat of the metal plate is transferred to the surface of the resin film in the laminating process, the embossed pattern changes, the printed ink discolors, and the printed design is limited. .. Further, in the post-design imparting method, the heat of the metal plate is transferred to the surface of the resin film in the laminating process, and the surface of the resin film becomes uneven, causing blurring and blurring in the pattern printed in the post-process, resulting in sharpness. It was sometimes inferior. Further, in both application methods, the resin film may be thermally deteriorated due to heating during lamination, and the yield may decrease.

Therefore, it has been required to lower the heating temperature when heating the metal plate. However, since the adhesive is not sufficiently softened simply by lowering the heating temperature, the anchor effect at the resin film / adhesive interface cannot be obtained, and in many cases, the adhesive force cannot be sufficiently exhibited. Here, a technique for ensuring the anchor effect at the resin film / adhesive interface by using a polyester resin having a low softening temperature has also been proposed. However, in this technique, since the adhesive layer has a low temperature, there is a problem that the curing reaction activity of the curing agent is low, the curing reaction does not proceed sufficiently, and the adhesive strength after lamination tends to be insufficient. .. As a result, the adhesive layer may coagulate and break, and the adhesive force between the metal plate / resin may not be sufficiently secured. If an attempt was made to supplement the decrease in activity with a catalyst or the like, the curing reaction rate might become too fast. In this case, the adhesive is cured before the resin film is laminated, so that the anchor effect cannot be sufficiently exhibited. Therefore, in order to solve these problems, an appropriate decrease in the softening temperature of the adhesive layer and an optimization of the curing reaction rate are the keys.

Conventionally, a resin in which the softening temperature of a polyester resin, an increase in the amount of functional groups of polyester and isocyanate, a resin in which the catalyst species and addition amount are optimized, and a resin in which the divergence temperature of isocyanate is specified has been disclosed. Even when used in the above, it was not possible to obtain a resin laminated metal plate that develops strong adhesion between the metal plate / resin film, secures the design given to the resin film, and can be manufactured with the target manufacturing yield. ..

For example, in the thermosetting resins disclosed in Patent Documents 1 and 2, it is suggested that the degree of curing of the adhesive before and after resin lamination can be controlled by using a blocked isocyanate that dissociates the curing agent at an appropriate temperature. There is. That is, by selecting a blocked isocyanate that does not deviate from the heating temperature of the metal plate, the flexibility of the adhesive layer can be maintained until immediately before the resin film is laminated, and the anchor effect of the resin film / adhesive interface can be ensured. Then, after laminating the resin film, the curing reaction between the dissociated isocyanate and the polyester proceeds, and there is a possibility that the strength of the adhesive layer can be exhibited. However, since only one type of blocked isocyanate is added to the resin, the divergence temperature range is narrow, and it is difficult to ideally control the degree of curing of the adhesive before and after lamination. As a result, the target adhesion strength may not be achieved in some cases.

Japanese Unexamined Patent Publication No. 2004-149703 Japanese Unexamined Patent Publication No. 2014-172930

An object of the present invention is to provide a resin laminated metal plate that exhibits strong adhesion between a metal plate / resin film, maintains and expresses a high-level design of the resin film, and can be manufactured with a target manufacturing yield. It is in.

The present inventors have found that the above problems can be achieved by obtaining a resin laminated metal plate which is composed of a specific resin and employs an adhesive having a certain degree of curing (gel fraction), and has reached the present invention. ..

That is, according to a certain aspect of the present invention, the adhesive layer comprises a metal plate, an adhesive layer laminated on at least one surface of the metal plate, and a resin film laminated on the adhesive layer. The adhesive contains a cured product of the adhesive, and the adhesive contains the following components (a) to (e), and the gel content when heated at 100 ° C to 140 ° C is 10 to 55%, and the gel content is 100 to 140 ° C. Provided is a resin laminated metal plate characterized by having a gel fraction of 70% or more after being heated at 40 ° C. for 5 days or heated at 230 ° C. for 30 seconds.
(A) Polyester resin A having a Tg of 30 to 80 ° C.
(B) Polyester resin B having a Tg of -30 to 20 ° C.
(C) Block isocyanate C1 having a dissociation temperature of 100 to 120 ° C.
(D) Block isocyanate C2 having a dissociation temperature of 140 to 160 ° C.
(E) Polyisocyanate compound D

According to another aspect of the present invention, the metal plate, the adhesive layer laminated on at least one surface of the metal plate, and the resin film laminated on the adhesive layer are provided, and the adhesive layer is bonded. The adhesive contains a cured product of the agent, and the adhesive has a ratio of 100 parts by mass of the following (a), 30 to 150 parts by mass of the following (b), and 1 to 50 parts by mass of the following (c) and (d) in total. Provided is a resin laminated metal plate comprising a main agent containing the following (e) and a curing agent containing the following (e) in a proportion of 30 to 80 parts by mass.
(A) Polyester resin A having a Tg of 30 to 80 ° C.
(B) Polyester resin B having a Tg of -30 to 20 ° C.
(C) Block isocyanate C1 having a dissociation temperature of 100 to 120 ° C.
(D) Block isocyanate C2 having a dissociation temperature of 140 to 160 ° C.
(E) Polyisocyanate compound D

Here, the resin film is composed of a plurality of or a single layer of the film layer, and the softening temperature of the film layer in contact with the adhesive layer may be less than 150 ° C.

Further, the resin film is composed of a plurality of or a single layer of a film layer, and at least the uppermost layer of the film layer may be a biaxially stretched film.

Further, the adhesive may contain 10 to 50 parts by mass of the epoxy resin E with respect to 100 parts by mass of the polyester resin A.

Further, the adhesive may contain 1 to 30 parts by mass of the silane coupling agent F with respect to 100 parts by mass of the polyester resin A.

Further, the adhesive may contain 1 to 30 parts by mass of the polycarbonate diol G with respect to 100 parts by mass of the polyester resin A.

According to another aspect of the present invention, the metal plate and the resin film are bonded to each other via an adhesive heated to 180 ° C. or lower, and the adhesive contains the following components (a) to (e) and is 100. The gel fraction when heated at ° C. to 140 ° C. is 10 to 55%, and the gel fraction after heating at 100 to 140 ° C. and then holding at 40 ° C. for 5 days or heating at 230 ° C. for 30 seconds is 70%. Provided is a method for manufacturing a resin laminated metal plate, which is characterized by the above.
(A) Polyester resin A having a Tg of 30 to 80 ° C.
(B) Polyester resin B having a Tg of -30 to 20 ° C.
(C) Block isocyanate C1 having a dissociation temperature of 100 to 120 ° C.
(D) Block isocyanate C2 having a dissociation temperature of 140 to 160 ° C.
(E) Polyisocyanate compound D

Here, by laminating an adhesive on at least one surface of the metal plate, an adhesive laminating step of forming an adhesive layer on the metal plate and heating the metal plate on which the adhesive layer is formed to 180 ° C. or lower. It may include a heating step, a resin film laminating step of laminating a resin film on an adhesive layer, and a cooling step of cooling a metal plate on which the resin film is laminated to room temperature.

According to another aspect of the present invention, the metal plate and the resin film are bonded to each other via an adhesive heated to 180 ° C. or lower, and the adhesive is 100 parts by mass of the following (a) and the following (b). A resin comprising 30 to 150 parts by mass, a main agent containing 1 to 50 parts by mass of the following (c) and (d) in total, and a curing agent containing 30 to 80 parts by mass of the following (e). A method for manufacturing a laminated metal plate is provided.
(A) Polyester resin A having a Tg of 30 to 80 ° C.
(B) Polyester resin B having a Tg of -30 to 20 ° C.
(C) Block isocyanate C1 having a dissociation temperature of 100 to 120 ° C.
(D) Block isocyanate C2 having a dissociation temperature of 140 to 160 ° C.
(E) Polyisocyanate compound D

Here, by laminating an adhesive on at least one surface of the metal plate, an adhesive laminating step of forming an adhesive layer on the metal plate and heating the metal plate on which the adhesive layer is formed to 180 ° C. or lower. It may include a heating step, a resin film laminating step of laminating a resin film on an adhesive layer, and a cooling step of cooling a metal plate on which the resin film is laminated to room temperature.

Here, the heating temperature of the adhesive may be 160 ° C. or lower.

As described above, according to the present invention, a resin laminated metal plate capable of exhibiting a strong adhesive force between a metal plate / a resin film, exhibiting an advanced printing design of a resin film, and being manufactured with a target manufacturing yield. Can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, the configuration of the resin laminated metal plate according to the present embodiment will be described.

<1. Composition of resin laminated metal plate>
(1-1. Overall configuration)
The resin laminated metal plate according to the present embodiment includes a metal plate, an adhesive layer laminated on at least one surface of the metal plate, and a resin film laminated on the adhesive layer, and the adhesive layer comprises. Contains a cured product of the adhesive. Here, the adhesive contains the following components (a) to (e), has a gel fraction of 10 to 55% when heated at 100 ° C. to 140 ° C., and is 40 after heating at 100 to 140 ° C. The gel fraction becomes 70% or more after holding at ° C. for 5 days or heating at 230 ° C. for 30 seconds.
(A) Polyester resin A having a Tg of 30 to 80 ° C.
(B) Polyester resin B having a Tg of -30 to 20 ° C.
(C) Block isocyanate C1 having a dissociation temperature of 100 to 120 ° C.
(D) Block isocyanate C2 having a dissociation temperature of 140 to 160 ° C.
(E) Polyisocyanate compound D

(1-2. Metal plate)
The type of the metal plate is not particularly limited, and a widely known metal plate can be used. Examples of the metal plate include a steel plate, a stainless steel plate, an Al plate, a Cu plate, a brass plate, a Ti plate, a chrome plate, a nickel plate, a zinc plate, a magnesium plate, and the like.

Here, examples of steel sheets include tin plates, thin tin-plated steel plates, electrolytic chromium acid-treated steel plates (tin-free steel plates), can steel plates such as nickel-plated steel plates, hot-dip galvanized steel sheets, hot-dip galvanized steel sheets, and hot-dip galvanized steel sheets. Hot-dip galvanized steel sheets such as hot-dip galvanized steel sheets, hot-dip aluminum-silicon alloy plated steel sheets, hot-dip lead-tin alloy plated steel sheets, electro-galvanized steel sheets, electro-galvanized steel sheets, electro-zinc-iron alloy-plated steel sheets , Electro-galvanized steel sheets such as galvanized iron-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 strengthening the adhesion with the adhesive layer and improving the rust prevention property. 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, and various inorganic films (for example, vanadium, titanium, zirconium, aluminum and magnesium). , Phosphorus-containing inorganic film), various organic films (for example, organic films containing polyacrylic acid resin, urethane resin, acrylic resin, etc.), silane coupling agent, etc. Can be mentioned.

(1-3. Resin film)
The type of the resin film is not particularly limited, and any resin film used for a conventional resin laminated metal plate can be used as the resin film of the present embodiment. As described above, the resin film may be subjected to various designs (for example, color, pattern, embossing, etc.). Examples of the designed resin film include a monochromatic design film, a patterned design film, and the like. The monochromatic design film is a design film colored with a pigment. The surface of a monochromatic design film is often embossed. Light reflection is suppressed by such embossing. The patterned 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 pattern design film. Further, the pattern design film may be produced by crimping a colored film colored with a pigment and a transparent protective film on which a pattern is printed. In this case, the pattern printing surface of the transparent protective film is directed toward the colored film side.

The resin constituting the resin film is not particularly limited. That is, any resin applicable to the conventional resin laminated metal plate can also be applied to the resin of the present embodiment. Examples of the resin constituting the resin film include a thermoplastic resin and a thermosetting resin. Examples of the thermoplastic resin include vinyl chloride resin, polyester resin, acrylic resin, polyolefin resin, fluororesin and the like. Examples of the thermosetting resin include urethane resin, urea resin, epoxy resin and the like. The resin film is preferably composed of any one or more of the above-mentioned resins, vinyl chloride resin, polyester resin, acrylic resin, polyolefin resin, and fluorine-based resin. Since the resin film composed of these resins is excellent in wettability and embossing processability for printing, it is easy to impart a high-level design. It also has excellent followability to the processing of metal plates. Hereinafter, examples of preferable resins will be described in detail.

The vinyl chloride resin is a resin containing a monomer unit containing chlorine. Examples of vinyl chloride resins include polyvinyl chloride, chlorinated polyvinyl chloride, polyvinylitene 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 ternary copolymer, vinyl chloride-styrene-acryloni little copolymer Combined, vinyl chloride-butadiene copolymer, vinyl chloride-isoprene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate ternary copolymer, vinyl chloride-maleic acid ester copolymer Chlorine-containing resins such as coalescing, vinyl chloride-methacrylic acid ester copolymers, vinyl chloride-acrylonitrile copolymers, vinyl chloride-various vinyl ether copolymers, and blends of them or their and other chlorine-free synthesis. Examples of resins include acrylonitrile-styrene copolymers, ethylene-vinyl acetate copolymers, ethylene-ethyl (meth) acrylylate copolymers, blends with polyesters, block copolymers, graft copolymers, and the like. ..

Further, when a resin film containing a vinyl chloride resin as a main component is produced, the resin film contains a diene resin containing no chlorine for the purpose of improving impact resistance, weather resistance, etc., MBS (methyl methacrylate butadiene styrene co-weight). Acrylic impact modifiers such as coalesced) and MBA (methyl methacrylate-butyl acrylate copolymer), and chlorine-free resins such as acrylic resins and fluororesins may be added. In the present embodiment, the "main component" of the resin film means a material contained in the resin film at a mass ratio of 50% by mass or more with respect to the total mass of the resin film. The amount of these additives added is preferably less than 50% by mass with respect to the total mass of the resin film. When the amount of the additive added is 50% by mass or more, the characteristics of the vinyl chloride resin may be difficult to develop. The amount of these additives added is preferably 3% by mass or more with respect to the total mass of the resin film. If it is less than 3% by mass, the film may be broken when an impact force is applied to the resin laminated metal plate.

Further, when a resin film containing a vinyl chloride resin as a main component is produced, a known plasticizer may be added to the resin film for the purpose of imparting flexibility and flexibility to the resin film. Examples of additives include phthalate plasticizers such as diheptylphthalate, dioctylphthalate, and diisononylphthalate, adipate plasticizers such as dioctyl adipate, diisononyl adipate, and di (butyl diglycol) adipate, and phosphates such as tricresyl phosphate. Examples thereof include based plasticizers, polyester plasticizers, chlorinated paraffin plasticizers, trimellitate plasticizers, pyromeritate plasticizers, biphenyltetracarboxylate plasticizers, and epoxy plasticizers. The amount of the plasticizer added is preferably 30% by mass or less with respect to the total mass of the design film. When the amount of the plasticizer added is larger than 30% by mass, a large amount of the plasticizer may move to the surface when the resin laminated metal plate is used for a long time. In this case, the design and surface function may be deteriorated such as tacking on the surface. The amount of the plasticizer added is preferably 3% by mass or more with respect to the total mass of the resin film. If it is less than 3% by mass, the film is hard, and when the resin laminated metal plate is processed, the film does not follow and cracks may occur.

Further, when a resin film containing a vinyl chloride resin as a main component is produced, the resin film is made of an organic acid alkaline soil such as barium stearate for the purpose of improving thermal stability, weather resistance, hiding property, and impact resistance. Metal salts, zinc organic acid such as zinc stearate, 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2, Addition of hindered amine compounds such as 2,6,6-tetramethyl-4-piperidylbenzoate and bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, and UV absorbers such as 2,4-dihydroxybenzophenone. You may. The amount of these additives added is preferably 0.01 to 10% by mass with respect to the total mass of the design film. If the amount added is less than 0.01% by mass, the function of the additive may not be fully exhibited. On the other hand, when the addition amount is larger than 10% by mass, coloring or burning may occur.

Further, when a resin film containing a vinyl chloride resin as a main component is produced, pigments such as rutile-type titanium dioxide and calcium carbonate may be added to the resin film for the purpose of imparting concealing properties to the resin film. The amount of the pigment added is preferably 1 to 30% by mass with respect to the total mass of the resin film. If the amount added is less than 1% by mass, the concealing property may be insufficient. If the amount added is more than 30% by mass, the resin film becomes brittle and film formation may become difficult. From the viewpoint of film forming property and concealment stability, the amount of the pigment added is more preferably 5 to 20% by mass.

When producing a resin film containing a vinyl chloride resin as a main component, the resin film contains diphenylthiourea, diphenylurea, anilinodithiotriazine, melamine, benzoic acid, silicic acid, p-th as additives other than the above. Stabilizers such as tributylbenzoic acid and zeolite may be added. Resin films include cross-linking agents, foaming agents, antistatic agents, antifogging agents, plate-out inhibitors, surface treatment agents, lubricants, flame retardants, fluorescent agents, fungicides, bactericides, and metal-free, as required. Additives such as activators, mold release agents, pigments, processing aids, antioxidants, light stabilizers and the like may be added. The amount of these additions is preferably 0.1 to 5% by mass with respect to the total mass of the resin film. When the addition amount is 0.1% by mass, the function of the additive may not be sufficiently exhibited. If the amount added is larger than 5% by mass, the characteristics such as the mechanical strength of the resin film may deteriorate.

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 in which a part or all of these is replaced with a hydroxylcarboxylic acid compound residue. More specific examples include PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PET-I, PBT-I, PET-G, PCT-G, PAr (polyarylate), and copolymers containing these as main components. Examples thereof include polymer resins and mixtures of two or more of these.

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 molar amount of the 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 the diol residue. 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 mole of diol residues. It is 50% or more and 80% or less with respect to the number.

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

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

Examples of fluorine-based resins include PVF (polyfluorovinyl), PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), PFA (polytetrafluoroethylene), PFEP (hexofluoroethylene propylene), and the like. Examples thereof include a resin having a fluorine skeleton, a copolymer of a fluorine-containing monomer and an olefin, and a copolymer of a fluorine-containing monomer and a chlorine-containing monomer. Examples of the copolymer of the fluorine-containing monomer and the olefin include ETFE (copolymer of tetrafluoroethylene and ethylene). Examples of the copolymer of the fluorine-containing monomer and the chlorine-containing monomer include PCTFE (polychlorotrifluoroethylene) and ECTFE (copolymer of ethylene and chlorotrifluoroethylene).

Among the resins listed above, particularly preferable resins are vinyl chloride resins, PET, PBT, PET-G, PET-I, PBT-I, PVF, PVDF, and acrylic resins containing methyl methacrylate as main components. Polyethylene resin and polypropylene resin. As for the design film containing these resins as the main component, the design film composed of these resins is particularly excellent in the wettability and embossing property of printing, and is also excellent in productivity.

The softening temperature of the resin film is not particularly limited, but the softening temperature of the portion in contact with the adhesive layer is preferably less than 150 ° C. Here, the softening temperature is measured by a thermomechanical analyzer (Thermal Mechanical Analysis). Specifically, while heating the sample at 2 ° C./min, a cylindrical needle having a diameter of 1 mm is pushed into the sample with a load of 500 mN. Then, the temperature at which the penetration depth of the cylindrical needle into the sample satisfies the following mathematical formula (1) is defined as the softening temperature. The penetration depth of the cylindrical needle into the sample is measured in accordance with JIS-K-7196.
_{t i / t 200 = 0.8 (} 1)
In Equation (1), _{t i} is the penetration _{depth, t 200} is a penetration depth when the sample temperature is 200 ° C.. Therefore, the left side of the formula (1) indicates the degree of softening.

Specifically, in the case of the pre-design imparting method, when the softening temperature of the portion in contact with the adhesive layer (hereinafter, also referred to as “adhesive layer contact portion”) is less than 150 ° C., a resin laminated metal plate is produced. It is possible to improve the adhesion between the resin film and the adhesive layer while suppressing changes in the embossed pattern and discoloration due to heating over time. That is, the adhesive layer contact portion is sufficiently softened even when heated to a temperature of 180 ° C. or lower, so that the adhesive force with the adhesive layer can be further improved.

In other words, the adhesive layer contact portion can further exhibit a sufficient anchor effect. Further, since the heating temperature of the resin film is 180 ° C. or lower, deterioration of the design can be suppressed. More preferably, it is desirable to laminate a pre-design film having a softening temperature of the adhesive layer contact portion of less than 150 ° C. and a softening temperature of the embossed portion of 150 ° C. or higher on a metal plate. The anchor effect can be exhibited even if the resin film is laminated on the adhesive layer having a temperature close to the softening temperature of the adhesive layer contact portion, and the embossed portion is not softened by heating at the time of lamination. As a result, it is easy to prevent the embossed shape from changing during lamination.

On the other hand, in the case of the post-design imparting method, a high-grade design having a high degree of mapping clarity is often required, so it is preferable to laminate a biaxially stretched film having excellent smoothness. More preferably, for the same reason as the previous design imparting method, it is desirable to laminate a biaxially stretched film having a softening temperature of less than 150 ° C. and 150 ° C. or higher, respectively, on the metal plate. .. As a result, it is easy to secure the adhesion and the smoothness of the surface to be printed. In order to ensure the smoothness of the surface to be printed, it is also important to ensure the flatness of the adhesive layer. As will be described later, by using the adhesive layer according to the present embodiment, the adhesive layer can be used. Flatness is achieved.

Here, examples of the resin having a softening temperature of less than 150 ° C. include the above-mentioned PET non-stretched film, PBT-I, PET-G, an acrylic resin containing methyl methacrylate as a main component, a polyethylene resin, and the like. .. Therefore, the adhesive layer contact portion may be formed of these resins.

The thickness of the resin film is not particularly limited. However, from the viewpoint of effectively utilizing the effects of the present embodiment, the thickness of the resin film is preferably 5 to 400 μm, more preferably 5 to 150 μm.

<3. Adhesive>
The adhesive layer according to the present embodiment is a cured adhesive having the following constitution. The adhesive contains the following components (a) to (e) as essential components.
(A) Polyester resin A having a Tg of 30 to 80 ° C.
(B) Polyester resin B having a Tg of -30 to 20 ° C.
(C) Block isocyanate C1 having a dissociation temperature of 100 to 120 ° C.
(D) Block isocyanate C2 having a dissociation temperature of 140 to 160 ° C.
(E) Polyisocyanate compound D

As described above, in the present embodiment, the matrix resin of the adhesive is composed of polyester resins A and B. In the present embodiment, by adding the polyisocyanate compound D to the adhesive, an appropriate viscosity can be imparted immediately after the adhesive is applied, and flow and dripping can be prevented to ensure workability. Further, since the glass transition temperature of the polyester resins A and B is low, the adhesive layer can be sufficiently softened even if the polyester resins A and B are heated and laminated at a low temperature of 180 ° C. or lower. Further, if the curing reaction of the adhesive layer proceeds sufficiently, the matrix resin can secure an appropriate strength.

Furthermore, by adding a two-component curing agent that dissociates at low and high temperatures, such as blocked isocyanates C1 and C2, to the adhesive, only a part of the curing agent (specifically, blocked isocyanate C1) is used when laminating the resin film. ), And the rest (specifically, blocked isocyanate C2) can be retained only by dissociation. As a result, even if shear stress is generated between the metal plate and the laminated resin (that is, the resin film) when the resin film is laminated, it is possible to impart a shear strength to the extent that these are not displaced. Further, since the blocked isocyanate C2 does not impair the flexibility of the matrix resin when the resin film is laminated, the anchor effect of the adhesive can be sufficiently exhibited and a strong adhesive force can be ensured. Moreover, the unevenness on the surface of the adhesive layer generated when the solvent in the adhesive evaporates can be leveled by the pressure at the time of laminating.

Further, the curing agent remaining unreacted immediately after resin lamination, that is, the isocyanate dissociated from the blocked isocyanate C2, can be cured by heating in a cooling step, curing, or a step of imparting a post-design. As a result, the strength of the adhesive layer can be ensured during actual use, and a strong adhesive force can be exhibited without the adhesive layer being coagulated and broken. Due to these effects, in the case of the pre-design, it is possible to prevent design deterioration such as change in embossed shape and discoloration, and to develop a strong adhesive force between the laminated resin and the metal plate. Further, even in the case of the post-design, it is possible to develop a strong adhesion between the laminated resin and the metal plate while ensuring the smoothness of the surface to be printed. The details will be described below.

(A) increases the strength of the adhesive resin, more specifically, the strength of the adhesive layer after curing is increased, (b) softens the adhesive resin at a low temperature, and (c) chemistry with the resin film. Affinity can be increased, and the viscosity and strength of the adhesive in the laminating process can be appropriately controlled by (e), and the adhesive layer can be prevented from adhering to the roll due to tack. Furthermore, according to (2), the curing reaction rate before and after laminating is appropriately controlled to exhibit the flexibility of the adhesive layer during laminating the resin film and the high strength after laminating (specifically, the high strength after curing). And the adhesion can be secured. As a result, it is possible to obtain a resin laminated metal plate that maintains and develops strong adhesion between the metal plate / resin film and has a high degree of design, and can be manufactured with a target manufacturing yield.

The glass transition temperature (Tg) of the polyester A constituting the adhesive according to the present embodiment must be 30 to 80 ° C. When the glass transition temperature (Tg) is lower than 30 ° C., the cohesive force after curing of the adhesive decreases, and the strength of the adhesive layer cannot be developed. On the contrary, when the glass transition temperature exceeds 80 ° C., the adhesive is less likely to be melted and softened when the resin film is laminated (that is, when the resin film is laminated), and the adhesion between the adhesive layer and the resin film and the metal plate is lowered. The glass transition temperature can be measured and specified by a differential scanning calorimetry device (DSC) or the like in accordance with ASTM D 3418-82. The molecular weight of the polyester A is not particularly limited, but those satisfying both the number average molecular weight of 3000 to 30,000 and the mass average molecular weight of 50,000 to 200,000 are preferable. If it is lower than both average molecular weights, the adhesive layer strength tends to be insufficient and the adhesive strength tends to decrease. On the contrary, if it exceeds both average molecular weights, the viscosity at the time of coating is too high and the coating suitability tends to decrease. be.

On the other hand, the Tg of the polyester resin B must be -30 to 20 ° C. If the glass transition temperature (Tg) is lower than −30 ° C., the viscosity immediately after coating the adhesive (that is, before heating) becomes insufficient, and the adhesive may be washed away from the metal plate. There is also the possibility that the adhesive will entrain air bubbles. On the contrary, when the glass transition temperature exceeds 20 ° C., the adhesive is less likely to be melted and softened when the resin film is laminated (that is, when the resin film is laminated), and the adhesion between the adhesive layer and the resin film and the metal plate is lowered. That is, the laminateability tends to decrease. The glass transition temperature of the polyester resin B is preferably -20 to 0 ° C. In this case, blocking can be further prevented, and the adhesive layer can be stably softened at a low temperature. The molecular weight of the polyester resin B is not particularly limited, but the number average molecular weight is preferably 5000 to 40,000 and the mass average molecular weight is preferably 5000 to 20000. If it is lower than both average molecular weights, the processability tends to decrease due to the decrease in flexibility, and conversely, if it exceeds both average molecular weights, the coating suitability tends to decrease.

Specific examples of polyester resins A and B include polyeste resins composed of polybasic acid residues and polyhydric alcohol residues in both resins. The polybasic acid residues include, for example, one or more dibasic acid residues such as phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, fumaric acid, adipic acid, azelaic acid, sebacic acid, dimer acid, and the like. , Lower alkyl esterified residues of these acids are mainly used, and if necessary, monobasic acids such as benzoic acid, crotonic acid, pt-butylbenzoic acid, trimellitic anhydride, methylcyclohexentricarboxylic acid, Residues of trivalent or higher polybasic acids such as pyromellitic anhydride are used in combination.

Examples of the polyhydric alcohol residue include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 3-methylpentanediol, 1,4-hexanediol, 1,6-hexanediol, and cyclohexane. Residues of dihydric alcohols such as diethanol are mainly used, and residues of trihydric or higher polyhydric alcohols such as glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol can be used in combination as needed. can. These polyhydric alcohol residues can be used alone or in admixture of two or more.

To exemplify the polyester resin A from a commercially available product, for example, VYLON 103, 200, 220, 226, 240, 245, 270, 280, 290, and 290 of Toyobo Co., Ltd. 296, 600, 660, 885, VYLON GK250, 360, 640, 780, 810, Unitika Ltd. ELITEL UE-3500, 3200, 9200, 9200, 3201, 3201, 3600, 9600, 3660, 3210, 3215, 3216, 3620, 3240, 3250, 3370, 3380, 3350, 3300, Toyobo Co., Ltd. Aronmelt PES-360, 316, SK Chemical SKYBON ES-100, 110, 120, 160, 250, 403, 410, 420, 450, 460M , 600, 660, 710, 750, 850, 900M, 901, 910, 955 and the like.

To exemplify the polyester resin B from a commercially available product, for example, VYLON 300, 500, 516, 550, 560, 630, 650, 670, VYLON manufactured by Toyobo Co., Ltd. GK130, 140, 150, 180, 190, 330, 590, 680, 890, VYLON BX-1001, Unitika Ltd. ELITEL UE-3220, 3223 , 3230, 3231, 3400, Toagosei Co., Ltd. Aronmelt PES-310, 320, 340, 345, 380, 390, SK Chemical Co., Ltd. Skybon ES- Examples thereof include 215, 220, 300, 320, 350, 360, 360M, 365, 500, 510, 601 and 906.

The adhesive according to the present embodiment contains blocked isocyanate C1 having a dissociation temperature of 100 to 120 ° C. and blocked isocyanate C2 having a dissociation temperature of 140 to 160 ° C. as the blocked isocyanate. That is, it is essential that the adhesive according to the present embodiment contains blocked isocyanates having different dissociation temperatures, that is, contains at least one type of blocked isocyanate selected from each dissociation temperature range. The dissociation temperature is a temperature at which the blocking agent is desorbed from the isocyanate group. Specifically, it can be defined as the temperature at which the blocked isocyanate is heated at a constant temperature in a nitrogen atmosphere, the blocking agent dissociates, and isocyanate groups begin to appear. To give an example of a specific method, while heating blocked isocyanate, the spectrophotometer was sequentially measured by an infrared spectrophotometer (FT-IR), a laser Raman spectrometer, or the like, and absorption peaks derived from isocyanate groups began to appear. The temperature etc. can be recognized as the dissociation temperature. When the structure of the dissociating blocking agent is clear, the dissociation temperature can be specified from the mass change and the temperature change of the dissociated component composition by using a thermal balance or decomposition gas chromatography.

In general, thermosetting adhesives have a strong adhesiveness and durability because the film is crosslinked by sufficiently reacting a base resin (main agent) such as polyester resin with a curable resin (curing agent) such as isocyanate resin. It leads to holding. On the other hand, when the resin film is laminated on the metal plate which is the base material, the adhesive does not adhere uniformly to the base material and the adhesive surface becomes uneven unless the adhesive is appropriately melted and softened by heat. On the other hand, the adhesive also needs to be cured to some extent by heating. This is because if the adhesive is insufficiently cured and the adhesive is softened too much, the fluidity of the adhesive becomes high during laminating, and bubbles and the like are likely to be involved.

Further, when the adhesive is rapidly cured, an increased internal stress is generated in the film, which causes poor adhesion to the base material. Therefore, when heated during laminating, it melts and softens, and at the same time, it cures appropriately to the extent that internal stress does not accumulate. The agent is ideal.

That is, in the present embodiment, not only the blocked isocyanate C2 that dissociates at the heating temperature of the metal plate (in other words, the lamination temperature when the resin film is laminated) but also the blocked isocyanate C1 that dissociates at a temperature lower than the lamination temperature is used as an adhesive. Mix in. As a result, it is possible to develop a shear strength to the extent that the metal plate / laminated resin (that is, the resin film) does not shift while ensuring the flexibility of the adhesive immediately before laminating the resin film. That is, when the resin film is laminated, the blocking agent is dissociated from the blocked isocyanate C1, and the cross-linking reaction between the polyester resins A and B, which are the main agents, and the isocyanate proceeds. However, when the resin film is laminated, the blocking agent is only dissociated from the blocked isocyanate C2, and the isocyanate hardly reacts with the polyester resins A and B. The isocyanate dissociated from the blocked isocyanate C2 reacts with the polyester resins A and B during the subsequent cooling step or curing. In the post-design imparting method, the isocyanate may react with the polyester resins A and B by the heating step at the time of imparting the design.

Therefore, since the adhesive is sufficiently softened even at a low temperature when the resin film is laminated, the adhesive force at the adhesive / laminated resin (that is, resin film) interface can be ensured even when the resin film is laminated at a low temperature. As a result, in the pre-design imparting method, the original design of the resin film can be maintained when the resin films are laminated. Further, after laminating the resin film, the curing reaction between the isocyanate dissociated from the blocked isocyanate C2 and the main polyester resins A and B proceeds at the laminating temperature, and the strength of the adhesive layer can be ensured. In addition, in the post-design imparting method, the surface of the resin laminated metal plate is required to be as smooth as possible in order to develop an advanced design. However, in the step of drying the solvent in the adhesive, irregularities are generated on the surface of the adhesive layer, which may appear on the resin surface after the resin is laminated, and the image clarity may be deteriorated. In this respect, in the present embodiment, even if the adhesive applied to the metal plate is heated and dried, only the curing reaction of the blocked isocyanate C1 proceeds. Therefore, since the adhesive is flexible, unevenness can be leveled by laminating pressure, and a high degree of smoothness is achieved. As a result, the surface of the laminated resin (that is, the resin film) is smoothed, and a higher degree of mapping sharpness can be exhibited. Further, since the surface of the resin laminated metal plate is required to be as smooth as possible, a biaxially stretched film is often used as the laminated resin (that is, the resin film). In addition, in the post-design method, the resin laminated metal plate is often heated at the time of designing (for example, at the time of embossing, printing and baking, etc.). In order to maintain the design even after such heating, it is necessary to suppress the shrinkage of the biaxially stretched film. In this respect, in the present embodiment, the strength of the adhesive layer can be sufficiently secured and the heat shrinkage of the resin film can be suppressed by sufficiently advancing the curing by the blocked isocyanate C2 after laminating the resin film. Further, even if unreacted isocyanates remain, these isocyanates react with each other by heating at the time of designing, and the adhesive is sufficiently cured.

Specifically, since it is at least necessary to heat the metal plate to a temperature at which the polyester resins A and B are sufficiently softened, the dissociation temperature range of the blocked isocyanate C1 is set to 100 to 120 ° C. As a result, the curing reaction between the blocked isocyanate C1 and the polyester resins A and B at the heating temperature of the metal plate is surely promoted, and the flow of the adhesive layer is prevented. Further, the dissociation temperature range of the blocked isocyanate C2 is set to 140 to 160 ° C. so that the dissociation reaction of the blocked isocyanate C2 proceeds sufficiently even at a temperature that does not change the design applied to the resin film.

As a means for confirming whether the above-mentioned block cyanates having different dissociation temperatures exert their effects under the assumed temperature conditions, there is a method of measuring the gel fraction of the film and estimating the degree of cross-linking. In this method, the uncrosslinked film component is dissolved and extracted into the solvent by immersing the film treated under constant heating conditions in a boiling solvent for a certain period of time. Therefore, the mass of the film before and after immersion. The degree of cross-linking of the film can be estimated by measuring the difference (JIS K6796).

When the gel fraction of the film was measured using the above method, the adhesive according to the present embodiment had a gel fraction of 10 to 55% when heated at 100 ° C to 140 ° C, and after heating at 100 to 140 ° C, After holding at 40 ° C. for 5 days or heating at 230 ° C. for 30 seconds, the gel fraction becomes 70% or more, which confirms that the above-mentioned blocked isocyanates having different dissociation temperatures are exerting their effects.

The blocked isocyanates C1 and C2 may be general as long as they are within the above-mentioned dissociation temperature range, and the adduct obtained by adding 3 mol of organic diisocyanate to 1 mol of trimethylolpropane is 3 mol. A burette obtained by reacting 1 mol of water with an organic diisocyanate, or a polyfunctional organic polyisocyanate having a bonding form such as isocyanurate obtained by polymerization of 3 mol of an organic diisocyanate is used, and the polyisocyanate and polyester are used. Polyurethane polyisocyanate compounds obtained by reacting polyols, polyether polyols or, if necessary, low molecular weight polyols are used. As an example of these, as aromatic polyisocyanates, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyldiisocyanate, tetraalkyldiphenylmethane Diisocyanate, dialkyldiphenylmethane diisocyanate, 1,3-phenylenediocyanate, polypeptide diphenylmethane diisocyanate, tolylene diisocyanate (2,4- or 2,6-tolylene diisocyanate or a compound thereof), 4,4'-toluidine diisocyanate, 4,4' Examples thereof include diphenyl ether diisocyanate, 1,5-naphthylene diisocyanate and naphthalene diisocyanate.

Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, trimethylene diisocyanate, trimethylhexamethylene diisocyanate (2,2,4- or 2,4,4-), lysine diisocyanate, xylylene diisocyanate, 1,2-propylene diisocyanate, and butylene. Examples thereof include diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, and 1,5-pentamethylene diisocyanate.

Examples of the alicyclic polyisocyanate include 1,3-cyclopentane diisocyanate, 1,3 cyclopentene diisocyanate, cyclohexanediisocyanate (1,3- or 1,4-), 3-isocyanate methyl-3,5,5-trimethylcyclohexylisocyanate. , Methylcyclohexanediisocyanate (-2,4- or -2,6-), norbornane diisocyanate and the like.

Examples of the blocking agent for blocking the isocyanate group of the polyisocyanate compound include phenols such as phenol, cresol (o, m, p) and xylenol, methanol, ethanol, n-propyl alcohol, isopropyl alcohol and n-butyl alcohol. , Isobutyl alcohol, alcohols such as acetoxime, methyl ethyl ketone oxime, acetoaldoxime, form aldoxime, diacetylmonooxime, cyclohexaneoxime and other oximes, methyl acetoacetate, ethyl acetoacetate, acetylacetone and other active methylene, ε -Examples include blocking agents such as lactams such as caprolactam, δ-valerolactam, γ-butyrolactam and β-propiolactam. Examples of this commercially available product include Coronate AP-M manufactured by Nippon Polyurethane Industry Co., Ltd., MS-50, 2503, 2507, 2513, 2515, and Death Module BL1100, 1265MPA / X manufactured by Sumika Bayer Urethane Co., Ltd. BL3272, BL3575, BL3475, BL3370, BL4265, BL5375, PL350, PL340, VPLS2253, VPLS2257, VPLS2078 / 2, Sumijule BL3175, Asahi Kasei Chemicals Duranate MF-K60B, SBN- 70D, MF-B60B, 17B-60P, TPA-B80E, E402-B80B, Mitsui Chemicals Takenate B-830, B-815N, B-820NSU, B-842N, B-846N , B870N, B874N, B882N and the like.

The polyisocyanate compound D may also have the above-mentioned components, and the commercially available products include Death Module N75MPA / X, Death Module N3200, Sumijour N3300, and Sumijour N3390 manufactured by Sumika Bayer Urethane Co., Ltd. , Same Death Module N3400, Same Death Module N3600, Same Death Module N3790, Same Death Module N3800, Same Death Module N3900, Same Death Module XP2580, Same Death Module XP2840, Same Sumijour HT, Same Death Module Z4470BA, Same Death Module XP2565 , Same Death Module XP2838, Same Death Module L75 (C), Same Death Module UL75XP, Same Death Module IL1351BA, Same Death Module IL1451BA, Same Death Module E14, Same Death Module E15, Same Death Module EXP2605, Same Sumijour E21-1 , Sumijour E21-2, SBU Isocyanate 0620, SBU Isocyanate M393, Death Module E22, Death Module E23, Death Module E29, Death Module RE, Death Module RFE, Duranate 24A- manufactured by Asahi Kasei Chemicals Co., Ltd. 100, Duranate 22A-75PX, Duranate TPA-100, Duranate THA-100, Duranate P-301-75E, Duranate 21S-75E, Duranate 18H-70B, Duranate MFA-75X, Duranate E402- 90T, Duranate E405-80T, Duranate TSE-100, Duranate TSA-100, Duranate TSS-100, Duranate D-101, Duranate D-201, Mitsui Chemicals Takenate D-101A Takenate D- 102, Takenate D-103, Takenate D-103H, Takenate D-103M2, Takenate D-104, MT-Orestar P-20, MT-Olestar P49-75S, MT-Olestar P51 -70, MT-Olestar P53-70S, MT-Olestar P56-70SS, Takenate D-204, Takenate D-204EA, Takenate D-212, Takenate D-21 2L, Takenate D-212M6, Takenate D-215, Takenate D-217, Takenate D-218, Takenate D-219, Takenate D-262, Takenate D-268, Takenate D-251A, MT-Orestar P3300, Takenate D-110N, Takenate D-120N, Takenate D-127N, Takenate D-140N, Takenate D-160N, Takenate D-165N, Takenate D-170N, Same Takenate D-170HN, Takenate D-172N, Takenate D-177N, Takenate D-178N, MT-Orestar NP1200, Takenate WD-220, Takenate WD-240, Takenate WD-250, Takenate Examples thereof include WD-720, Takenate WD-723, Takenate WD-725, Takenate WD-726, and Takenate WD-730.

In order for the adhesive according to the present embodiment to exhibit the above-mentioned action, the mass ratio of the polyester resin B is 30 to 150 parts by mass with respect to 100 parts by mass of the polyester resin A (in terms of solid content, the same applies hereinafter). There is a need. The mass ratio of the polyester resin B is preferably 70 to 110 parts by mass. If the mass ratio of the polyester resin B is lower than 30 parts by mass, the Tg of the adhesive is too high, and the laminateability tends to decrease. Further, when the mass ratio of the polyester resin B exceeds 150 parts by mass, the Tg is too low, so that the adhesive is too softened at the time of heating, and there is a tendency that bubbles and the like are easily involved. Further, the mass ratio of the blocked isocyanates C1 and C2 needs to be 1 to 50 parts by mass in total with respect to 100 parts by mass of the polyester resin A. The mass ratio of the blocked isocyanates C1 and C2 is preferably 5 to 20 parts by mass in total. When the total mass ratio of the blocked isocyanates C1 and C2 is lower than 1 part by mass, the degree of cross-linking of the adhesive tends to be low and the cohesive force tends to be low. On the contrary, when the mass ratio of the blocked isocyanates C1 and C2 exceeds 50 parts by mass in total, the unreacted functional groups react with the moisture in the air and take a rigid structure, so that the processability tends to decrease. The mass ratio of the polyisocyanate compound D needs to be 30 to 80 parts by mass with respect to 100 parts by mass of the polyester resin A. The mass ratio of the polyisocyanate compound D is preferably 45 to 65 parts by mass. If the mass ratio of the polyisocyanate compound (D) is less than 30 parts by mass, the cross-linking reaction with the polyester resin (that is, the urethanization reaction) becomes insufficient, and the substrate followability at the time of laminating is inferior. On the other hand, if it exceeds 80 parts by mass, it may react excessively with the moisture in the air, resulting in a fragile film.

The adhesive according to the present embodiment can improve the adhesion of the coating film by further adding the epoxy resin E. The mass ratio of the epoxy resin E is preferably 10 to 50 parts by mass, and more preferably 25 to 35 parts by mass with respect to 100 parts by mass of the polyester resin A. If the mass ratio of the epoxy resin E is lower than 10 parts by mass, the adhesion strength with the base material may not be obtained. On the contrary, if the mass ratio of the epoxy resin E exceeds 50 parts by mass, the film lacks flexibility and is processed. May be inferior in sex.

Examples of the epoxy resin E include commercially available epibis type, novolak type, β-methylepicro type, cyclic oxylan type, glycidyl ether type, glycidyl ester type, polyglycol ether type, glycol ether type, and epoxidized fatty acid. Examples thereof include various epoxy resins such as an ester type, a polyvalent carboxylic acid ester type, an aminoglycidyl type, and a resorcin type.

Examples of commercially available products of the epoxy resin E include modified novolac type epoxy resins such as EPIKOAT 1001, EPIKOAT 1004, EPICLON N-865, and EPICLON N-870 as BPA type products. Preferably, as an example of the epoxy resin (C-1) containing no bisphenol A, a phenol novolac type epoxy resin such as EPICLON N-730, EPICLON N-740, EPICLON N-770 manufactured by DIC Co., Ltd., EPICLON N- 660, EPICLON N-665, EPICLON N-670, EPICLON N-673, EPICLON N-680, EPICLON N-690, EPICLON N-695, AER ECN-1273 manufactured by Asahi Kasei Epoxy Co., Ltd., AER ECN- Examples thereof include a cresol novolac type epoxy resin such as 1299. Further, an epoxy resin containing no bisphenol A is preferable because unreacted bisphenol A does not elute, especially in terms of living hygiene and food applications. The bisphenol A-free epoxy resin means an epoxy resin that does not contain a structure derived from the bisphenol A skeleton.

A silane coupling agent F may be further added to the adhesive according to the present embodiment for the purpose of improving the adhesive force with the metal plate. The mass ratio of the silane coupling agent F is preferably 1 to 30 parts by mass, and more preferably 5 to 15 parts by mass with respect to 100 parts by mass of the polyester resin A. If the mass ratio of the silane coupling agent F is lower than 1 part by mass, the original effect is low and the adhesion to the substrate is not expected to be improved. On the contrary, if the mass ratio of the silane coupling agent F exceeds 30 parts by mass, there is no reaction. Since a large amount of the silane coupling agent F is present at the substrate / adhesive interface, it may cause poor adhesion.

Specific examples of the silane coupling agent F include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, and N-β (aminoethyl). Aminosilanes such as −γ-aminopropyltrimethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane; β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ -Epoxysilanes such as glycidoxypropyltriethoxysilane; vinylsilanes such as vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane; hexamethyldisilazane, γ -Mercaptopropyltrimethoxysilane and the like can be mentioned.

Further, the polycarbonate diol G can be added for the purpose of improving the water resistance of the adhesive. By adding the polycarbonate diol G to the adhesive, it becomes easy to maintain a strong adhesive force between the resin / metal plate even when the resin laminated metal plate is used in an environment where it is easily flooded or humid. In this case, the number average molecular weight of the polycarbonate diol G is preferably 500 to 3000, more preferably the number average molecular weight is 800 to 2000, and the hydroxyl value is preferably 20 to 200, more preferably 50 to 150. When the number average molecular weight is less than 500, the improvement of water resistance tends to be insufficient, and when the number average molecular weight exceeds 3000, the compatibility with other resins tends to decrease. Further, when the hydroxyl value is 20 or less, the reactivity tends to be low and the improvement in water resistance tends to be low, and when the hydroxyl value is 200 or more, the reaction tends to be excessive and the processability tends to be lowered. The mass ratio of the polycarbonate diol G is preferably 1 to 30 parts by mass, and more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the polyester resin (A). If the mass ratio of the polycarbonate diol G is lower than 1 part by mass, the original effect is low and the water resistance is not expected to be improved. On the contrary, if the mass ratio of the polycarbonate diol G exceeds 30 parts by mass, curing inhibition is caused, and the adhesive The cohesive force tends to be low. As commercial products, Daicel Co., Ltd.'s Praxel CD205PL, CD210, CD220, CD220PL, Asahi Kasei Chemicals Co., Ltd.'s Duranol T6002, T6001, T5652, T5651, T5651J, T5651E, G4672, T4671, T4692, T4691 And so on.

An organic pigment or an inorganic pigment can be added to the adhesive according to the present embodiment for the purpose of coloring. Examples of this component include chromate (chrome yellow, chromium vermilion) ferrocyanide (prussian blue), sulfide (cadmium ero, cadmium red), oxide (titanium oxide, red iron oxide, iron black) sulfate (barium sulfate,). Inorganic pigments such as lead sulfate), silicate (ultrablue, calcium silicate), carbonate (calcium carbonate, magnesium carbonate) phosphate (cobalt violet) metal powder (aluminum powder, bronze) carbon (carbon black), azo (benzidine) Yellow, Hansa Yellow, Balkan Orange, Permanent Red F5R, Carmine 6B, Lake Red C, Chromoftal Red, Chromoftal Yellow), Phtalocyanin Blue (Phrussian Nin Blue, Phtalussian Green), Dyeing Dye (Induslen) Organic pigments such as blue, thioingigobordeaux) dyed rake (Eosin lake, quinoline yellow, Rhodamine lake, methyl violet lake), quinacdrine (Cincasia red, Cincasia violet), geokidicin (PV fast violet BL), etc. These can be used alone or in combination. These pigments make it possible to color the coating film and impart designability, and any organic pigment or inorganic pigment can be added to the required design.

Among them, white pigments such as titanium oxide can be suitably used for the purpose of concealing the dull appearance color peculiar to steel plates. Generally, a thick plastic film kneaded with titanium oxide or the like is used as a means for imparting concealment to the laminated steel plate, but by including titanium oxide or the like in the adhesive, the concealment is exhibited and the plastic is plastic. It is possible to make the film thinner, and in some cases a transparent film can be used, leading to a significant cost reduction.

As the titanium oxide that can be used in this embodiment, the particle size produced by the sulfuric acid method is in the range of 0.1 to 0.4 μm, and a silica or alumina-treated surface treatment agent is preferably used. The blending amount is not particularly limited as long as it does not impair the performance of the adhesive, but when the total of the polyester resin A to the polyisocyanate compound D components is 100 parts by mass, the titanium oxide is 30. It is preferably in the range of ~ 200 parts by mass, more preferably 50 to 100 parts by mass. Titanium oxide produced by the chlorine method generally has a higher Mohs hardness than that produced by the sulfuric acid method, and tends to reduce workability because the doctor blade is easily worn during printing. When the particle size of titanium oxide is less than 0.1 μm, the hiding property is inferior, and when it exceeds 0.4 μm, it tends to cause meat kneading inhibition.

The adhesive according to the present embodiment may be laminated on a metal plate in a state of being dissolved in a solvent. The solvent is volatilized by the heating process of the metal plate. The solvent that can be used in this embodiment is not particularly limited, but is, for example, an aromatic hydrocarbon system such as toluene, xylene, sorbesso # 100, sorbesso # 150, or an aliphatic hydrocarbon system such as hexane, heptane, octane, or decane. , Methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate, ethyl formate, butyl propionate and other ester-based organic solvents. As water-mixable organic solvents, alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone and cyclohaxanone, ethylene glycol (mono, di) methyl ether, ethylene glycol (mono, di) ethyl ether and ethylene Glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di) methyl ether, diethylene glycol (mono, di) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, di) methyl Examples thereof include various glycol ether-based organic solvents such as ether, propylene glycol (mono, di) methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and dipropylene glycol (mono, di) methyl ether. Of these, it is usually preferable to use methyl ethyl ketone, ethyl acetate, or a mixture thereof.

If necessary, a lubricant, an antifoaming agent, a leveling agent, a pigment, or the like can be added to the adhesive according to the present embodiment. Further, as the curing aid, other curing agents such as urea resin, melamine resin, benzoguanamine resin, isocyanate resin, and polyamide resin may be used in combination. These additives are selected according to the heating temperature of the adhesive, the laminating conditions, and the like.

The adhesive layer according to the present embodiment is a cured adhesive described above. As described above, the adhesive is sufficiently difficult when laminating the resin film on the metal plate, and is sufficiently cured after laminating the resin film on the metal plate. The cured product of the adhesive has a structure in which the polyester resin is crosslinked by isocyanate residues.

<2. Manufacturing method of resin laminated metal plate>
Next, a method for manufacturing the resin laminated metal plate will be described. The method for producing the resin laminated metal plate according to the present embodiment may be any method as long as the metal plate and the resin film are laminated via an adhesive heated to 180 ° C. or lower. Here, the metal plate, the resin film, and the adhesive are as described above. More specifically, after applying the above adhesive to the metal plate, the metal plate is heated to a predetermined temperature. Then, there is a method in which a resin film is pressure-laminated on the surface coated with the adhesive layer of the heated metal plate and then cooled to room temperature. Further, after applying the above adhesive to the resin film, the resin film is heated. Then, there is a method in which the adhesive-coated surface of the heated resin film is pressure-laminated on the surface of the metal plate and then cooled. According to these methods, the resin laminated metal plate according to the present embodiment can be industrially and stably produced with economic rationality. By setting the heating temperature at this time to 180 ° C. or lower, it is possible to manufacture a resin laminated metal plate having more stable design and strong adhesion. In any step, the heating temperature of the metal plate needs to be 180 ° C. or lower, preferably 160 ° C. or lower. When the metal plate is heated to over 180 ° C., the resin surface is heated and melted, the embossed pattern is changed, the pigment is sublimated and faded, and the design may be deteriorated. Further, it is desirable to heat the resin film to a temperature equal to or higher than the softening temperature of the adhesive layer contact portion. By heating to a temperature equal to or higher than the softening temperature, the anchoring effect between the laminated resin and the adhesive layer is increased, and in many cases, a stronger adhesive force can be exhibited. In this case, by setting the softening temperature of the adhesive layer contact portion of the resin film to less than 150 ° C., the anchor effect between the laminated resin and the adhesive layer is more likely to be exhibited, and stronger adhesion can be easily obtained. However, when the softening temperature of the layer in contact with the adhesive is more than 180 ° C., it is desirable to select it depending on whether the design or the adhesion is prioritized.

Further, in the present embodiment, since the adhesive having the above-mentioned composition is used, the adhesive can be sufficiently softened when the resin film is laminated. As a result, the resin film and the metal plate can be brought into close contact with each other by a sufficient anchor effect. In addition, the surface irregularities of the resin film are leveled by crimping. Further, since the adhesive is sufficiently cured by the cooling step and curing after laminating the resin film, it is possible to develop and maintain a more advanced design in the post-design imparting method.

A known method can be widely applied to the method of applying the above adhesive to a metal plate or a resin film. Specifically, each adhesive layer may be formed by a roll coater method, a bar coater method, a spray coating method, a dip method, a method of laminating a film-like adhesive, or the like. Above all, the roll coater method is preferable from the viewpoint of productivity.

Hereinafter, the resin laminated metal plate and the manufacturing method thereof according to the present embodiment will be specifically described with reference to Examples. In the following examples, "parts" and "%" represent "parts by mass" and "% by mass", respectively.

<1. Adhesive preparation>
The materials listed below were prepared as the materials constituting the adhesive.
(1) Polyester resin (A-1)
Byron GK360, manufactured by Toyobo Co., Ltd., glass transition temperature 56 ° C., 30% solution (dissolved in a mixed solution of methyl ethyl ketone / ethyl acetate = 50/50 (volume ratio, the same applies hereinafter))
(2) Polyester resin (A-2)
Byron GK140, manufactured by Toyo Boseki Co., Ltd., glass transition temperature 20 ° C, 30% solution (dissolved in a mixed solution of methyl ethyl ketone / ethyl acetate = 50/50)
(3) Polyester resin (A-3)
Elitel UE-3690, manufactured by Unitika Ltd., glass transition temperature 90 ° C., 30% solution (dissolved in a mixed solution of methyl ethyl ketone / ethyl acetate = 50/50)
Therefore, the polyester resin A-1 satisfies the requirements of the present embodiment, but the polyester resins A-2 and A-3 do not satisfy the requirements of the present embodiment.
(4) Polyester resin (B-1)
Byron 550, manufactured by Toyobo Co., Ltd., glass transition temperature -15 ° C, 30% solution (dissolved in a mixed solution of methyl ethyl ketone / ethyl acetate = 50/50)
(5) Polyester resin (B-2)
Elitel UE-3410, manufactured by Unitika Ltd., glass transition temperature -32 ° C, 30% solution (dissolved in a mixed solution of methyl ethyl ketone / ethyl acetate = 50/50)
(6) Polyester resin (B-3)
Byron GK103, manufactured by Toyobo Co., Ltd., glass transition temperature 47 ° C, 30% solution (dissolved in a mixed solution of methyl ethyl ketone / ethyl acetate = 50/50)
Therefore, the polyester resin B-1 satisfies the requirements of the present embodiment, but the polyester resins B-2 and B-3 do not satisfy the requirements of the present embodiment.
(7) Blocked isocyanate (C1-1) = BL3475BA / SN (dissociation temperature 100 ° C.), manufactured by Sumika Cobestro Urethane Co., Ltd. (8) Blocked isocyanate (C2-1) = Sumijour BL3175 (dissociation temperature 140 ° C.) ), Sumika Cobestro Urethane Co., Ltd. (9) Blocked Isocyanate (C1-2) = Duranate MF-B60X (Dissociation temperature 120 ° C.), Asahi Kasei Chemicals Co., Ltd. (10) Blocked Isocyanate (C2-2) ) = Death Module BL3272MPA (dissociation temperature 160 ° C), manufactured by Sumika Cobestro Urethane Co., Ltd. (11) Block isocyanate (X-1) = MF-K60B (dissociation temperature 90 ° C), manufactured by Asahi Kasei Chemicals Co., Ltd. (12) Blocked isocyanate (X-2) = Death module VPLS2078 / 2 (dissociation temperature 170 ° C.), manufactured by Sumika Cobestrourethane Co., Ltd. Therefore, blocked isocyanates X-1 and X-2 are requirements of the present embodiment. Does not meet.
(13) Polyisocyanate compound (D) = Vernock DN980 (HDI isocyanurate type), manufactured by DIC Co., Ltd. (14) Epoxy resin (E)
Epicron N-660, cresol novolac type epoxy resin manufactured by DIC Co., Ltd., 50% methyl ethyl ketone solution (15) Silane coupling agent (F) = KBM-403 (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. Co., Ltd. (16) Polycarbonate resin (G) = Praxel CD210, Daicel Chemical Co., Ltd. Number average molecular weight 1000, hydroxyl value about 110

Next, the above raw materials are weighed and mixed with an electronic balance at the ratios shown in Tables 1 to 3 (the numbers in the table indicate the mass parts of the solid content), and then using a dispersion stirrer at a temperature of 25 ° C. and 3000 rpm. It was stirred for 1 minute at the rotation speed of. As a result, the adhesives of Examples 1 to 28 and Comparative Examples 1 to 12 were prepared. Tables 1 to 3 also describe the heating method, heating temperature, and the following evaluation results.

<2. Fabrication of resin laminated metal plate>
(2-1. Preparation of metal plate)
As metal plates, two types of zinc-based gold steel plates with a thickness of 0.45 mm (Nippon Steel & Sumikin Super Dimer (K08) (hereinafter, also referred to as "SD steel plates"), GI steel plates (Z18)), Al plates (A5052, 1) .2 mm thick) and 0.3 mm thick titanium foil (JISH4600 standard product manufactured by Nippon Steel & Sumitomo Metal) were prepared. Then, after performing alkaline degreasing treatment on these metal plates, a chromate solution was applied to ^{form a chromate film of about 45 mg / m 2 on} the surface of the metal plate.

(2-2. Preparation of resin film)
Using a two-layer T-die, a PET layer containing white pigment (20% by mass) (white PET layer) and a PET alloy layer (PET (Unitika SP1344) / VLDPE (ultra-low density polyethylene) (Dow DFDA-1137) ) / Compatibility agent (Bondfast 7L manufactured by Sumitomo Chemical Co., Ltd.) = 87/10/3 (volume ratio)) was obtained as a monochromatic film. The thickness of the film was 100 μm, the white PET layer was 90 μm (upper layer), and the PET-based alloy layer was 10 μm (lower layer: a layer in contact with the adhesive layer). The film is called a white PET film.

Similarly, a 100 μm film (hereinafter referred to as a white PBT film) having a white PBT layer (white pigment-containing (20% by mass) PBT layer) as the upper layer and a PBT (transparent) layer as the lower layer was prepared. Further, a film having a PET alloy layer to which a white pigment was added as an upper layer and a white PET layer as a lower layer was produced (hereinafter, referred to as a white PET alloy film). The upper surface of these films was given a striped embossed pattern with a depth of 20 μm, and the flat portion was mirror-finished. In addition, a 70 μm transparent biaxially stretched PET film (BO-PET film, manufactured by Unitika: S-75, double-sided corona treatment) and a white vinyl chloride film (manufactured by Okamoto Co., Ltd., 100 μm thick) were also prepared. .. The same embossed pattern as the white PET film was imparted to one side surface of the white PVC film. The softening temperatures of the PET alloy layer, PBT layer, BO-PET, and white PVC film were 135 ° C., 220 ° C., 260 ° C., and 140 ° C., respectively.

(2-3. Preparation of resin laminated metal plate)
A resin laminated metal plate was produced by any of the following production methods A and B. The composition of the adhesive used, the type of metal plate, and the type of resin film are shown in Tables 1 to 3.
(2-3-1. Production method A)
First, the adhesive was applied to a metal plate with a bar coater so as to have a dry film thickness of 10 μm, and dried with a dryer to prepare an adhesive-coated metal plate. Then, after heating the adhesive-coated metal plate, the films were laminated and pressurized. The heating temperature (stacking temperature) is shown in Tables 1 to 3. After unloading, it was water-cooled to room temperature to obtain a resin laminated metal plate. The white PET and white PVC films were laminated so that the embossed surface and the opposite surface were on the metal plate side.

(2-3-2. Production method B)
First, the adhesive was applied to the resin film with a bar coater so as to have a dry film thickness of 10 μm, and dried with a dryer to prepare an adhesive-coated film. Then, after heating the adhesive-coated film, it was laminated on the adhesive-coated metal plate and pressed. The heating temperature (stacking temperature) is shown in Tables 1 to 3. After unloading, it was water-cooled to room temperature to obtain a resin laminated metal plate.

<3. Measurement of adhesive gel fraction>
The adhesive-coated metal plate was subjected to any of the following steps a to c.
a. The adhesive-coated metal plate was treated at 140 ° C./30 seconds.
b. The adhesive-coated metal plate was treated at 140 ° C./30 seconds and then treated at 40 ° C./5 days under heating conditions assuming a curing treatment.
c. After the adhesive-coated metal plate was treated at 140 ° C./30 seconds, it was treated at 230 ° C./30 seconds as a heating condition assuming a post-design imparting step.
Then, the adhesive-coated metal plate subjected to the steps a to c was immersed in xylene and refluxed to extract and remove the non-gelled component. Then, the gel fraction was calculated by the formula shown below.
Gel fraction (%) = (mass of coated adhesive after extraction) ÷ (mass of coated adhesive before extraction) x 100
(1)

<4. Evaluation item 1: Adhesive laminating suitability>
The surface of the resin laminated metal plate was visually observed to evaluate the presence or absence of film wrinkles and eups. Further, the peeled surface of the resin laminated metal plate after the film peeling test (initial adhesion strength test described later) was observed to evaluate the presence or absence of air bubbles mixed in the adhesive layer in the laminating process. The evaluation criteria are the following four stages, and ○ or higher is the pass level. The evaluation results are summarized in Tables 1 to 3. In addition, "/" of each evaluation item in the table indicates that evaluation is impossible for some reason (for example, the resin film could not be laminated, the resin film to be evaluated could not be embossed in the first place, etc.).
⊚: Very good with no bubbles, wrinkles, unevenness, etc.
◯: Bubbles, wrinkles, unevenness, etc. are slightly observed, but most of them are good.
Δ: A relatively large number of bubbles, wrinkles, unevenness, etc. are observed.
X: Bubbles, wrinkles, unevenness, etc. are found in most of the cases.
In Comparative Example 6, since the blocked isocyanate C1 was not contained in the adhesive, a deviation occurred at the metal plate / laminated resin (that is, resin film) interface.

<5. Evaluation item 2: Evaluation of design of resin laminated metal plate>
The embossing depth of the surfaces of the resin film and the resin laminated metal plate was measured by a three-dimensional roughness meter (NX001-2 manufactured by Tokyo Seimitsu Co., Ltd.) (Ra1 and Ra2, respectively). The embossing return rate of the resin laminated metal plate was calculated from the following formula, and the embossing soundness was evaluated.
Embossed return rate χ: χ = {1-Ra2 / Ra1} × 100 (2)
⊚: Embossing return rate 5% or less ○: 10% or less, Δ: 15% or less, ×: more than 15% Furthermore, the reflectance (incident angle 60 °) of the surface mirror surface of the resin film and the resin laminated steel plate is measured by a glossimeter (incident angle 60 °). GM60Pulus manufactured by Minolta) (Re1 and Re2, respectively). Then, the design of the resin laminated steel sheet was evaluated according to the following criteria.
Gloss change rate y: y = {1-Re2 / Re1} × 100 (3)
⊚: Gloss change rate 5% or less ○: 10% or less, Δ: 15% or less, ×: more than 15%

Further, the sharpness (map sharpness: PGD value) of the image reflected on the mirror surface of the surface of the resin film and the resin laminated metal plate was measured with a PGD meter (manufactured by Japan Color Research Institute). Then, the map was evaluated as follows based on the change ΔP in the map sharpness before and after stacking. If it is not ◯ or higher for the white film laminated metal plate and ◎ for the BO-PET film laminated metal plate, it will adversely affect the printing of the post-design.
ΔP = (PGD value of resin film)-(PGD value of resin laminated metal plate) (4)
⊚: Gloss change rate 0, ○: 0.1, Δ: 0.2-0.3, ×: more than 0.4

<6. Evaluation item 3: Initial adhesion strength between laminated resin / metal plate>
The resin layer was peeled from the test piece of the resin laminated metal plate cut to a width of 2.5 cm to the extent that it could be gripped by a tensile tester, and a peel test was conducted at a peeling speed of 30 mm / min at an angle of 180 °. Based on the peel strength value at this time, the initial adhesion strength between the metal plate and the laminated resin layer was evaluated as follows. ○ The above is the pass level.
⊚: 46N / 2.5cm or more
◯: 40 to 45 N / 2.5 cm
Δ: 20 to 39 N / 2.5 cm
X: less than 20N / 2.5cm

<7. Evaluation item 4: Durable adhesion between laminated resin layer / metal plate>
Assuming that the resin laminated metal plate was used in a humid place such as a bathroom, the resin laminated metal plate was immersed in boiling water for 2 hours. Since the permeation of the film or adhesive of water molecules is accelerated by immersion in boiling water, the durability of the adhesive force between the laminated resin and the metal plate can be evaluated. After wiping off the water adhering to the immersed resin laminated metal plate with a filter paper, a # type notch having a width of 5 mm was made in the laminated film with a cutter knife. Here, the depth of the cut was set to a depth that reached the metal plate. Then, using an Eriksen tester (DKSH, Eriksen tester), the #-shaped notch was projected by 8 mm. Here, the center of the overhanging portion (top portion) was aligned with the center of the #-shaped notch portion. Then, the #-shaped notch was forcibly peeled off with tweezers, and the degree of peeling was evaluated according to the following criteria.
◎ ◎: Score 5 (Film coagulates and breaks with almost no peeling)
◎: Score 4 (only the top part is peeled off)
◯: Score 3 (The entire top part and less than 1/3 of the side part are peeled off. In addition, when the cut is made with a cutter, it is also marked as ○, but the adhesion is stronger if there is no opening)
X: Score 2 (the entire top and the entire side surface are peeled off)
XX: Score 1 (the entire top part, the entire side surface processed part, and the circumference of the #-shaped notch are peeled off)
Then, the same test was repeated 5 times. If there are variations in evaluation for each test, the upper and lower limits of evaluation are listed in the table.

The number average molecular weight (in terms of polystyrene) measured by GPC in this example was measured by using an HLC8220 system manufactured by Tosoh Corporation under the following conditions.
Separation column: Uses 4 _{TSKgelGMH HR-N manufactured by Tosoh Corporation.} Column temperature: 40 ° C. Moving layer: Tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow velocity: 1.0 ml / min. Sample concentration: 1.0% by mass. Sample injection volume: 100 microliters. Detector: Differential refractometer.

The glass transition temperature (Tg) was measured by scanning under the conditions of a temperature range of −80 to 450 ° C. and a temperature rise temperature of 10 ° C./min using a cooling device in a differential atmosphere.

The dissociation temperature at which the blocking agent is desorbed from the isocyanate group is determined by applying a 50% by mass methyl ethyl ketone solution of the blocked isocyanate compound thinly on a bromine chloride plate, drying it at 20 ° C. for 5 hours or more in a nitrogen atmosphere, and then using a heating furnace. Heated at a constant temperature from 20 ° C. to 10 ° C. for 5 minutes in a nitrogen atmosphere, and sequentially measured in real time with an infrared spectrophotometer (FT-IR), the expression of absorption peaks derived from each isocyanate group started. The temperature obtained was defined as the block dissociation temperature of the blocked isocyanate compound.

As is clear from Tables 1 to 3, good results were obtained in all the evaluation items in the resin laminated metal plate according to the examples, whereas in all the evaluation items in the resin laminated metal plate according to the comparative example. A low rating was obtained. In Comparative Example 1, the glass transition temperature of the polyester resin A was too low, and the adhesive layer coagulated and fractured. Further, in Comparative Example 2, the glass transition temperature of the polyester resin A was too high, and the adhesive layer was not sufficiently softened when the resin films were laminated. Therefore, the resin film and the metal plate could not be sufficiently brought into close contact with each other. Further, in Comparative Example 3, the glass transition point of the polyester resin B was too low, and air bubbles were involved during the laminating of the resin film. Further, in Comparative Example 4, the glass transition point of the polyester resin B was too high, and the adhesive layer was not sufficiently softened when the resin films were laminated. In Comparative Example 5, since the adhesive did not contain the blocked isocyanate C2, the adhesive layer was cured when the resin film was laminated. Therefore, the resin film and the metal plate could not be sufficiently brought into close contact with each other. In Comparative Example 6, since the blocked isocyanate C1 was not contained in the adhesive, a deviation occurred at the metal plate / laminated resin (that is, resin film) interface. In Comparative Examples 7 and 9, the dissociation temperature of the blocked isocyanate X-1 was too low, and the adhesive layer was cured when the resin films were laminated. Therefore, the resin film and the metal plate could not be sufficiently brought into close contact with each other. In Comparative Example 8, the dissociation temperature of the blocked isocyanate X-2 was too high, and the adhesive layer was not sufficiently cured. Therefore, the adhesive layer coagulated and fractured. In Comparative Example 10, since the mass ratio of the blocked isocyanates C1 and C2 exceeds 50 parts by mass in total, the adhesive layer was cured when the resin film was laminated. Therefore, the resin film and the metal plate could not be sufficiently brought into close contact with each other. In Comparative Example 11, since the mass ratio of the polyisocyanate compound D exceeded 80 parts by mass, the adhesive layer became fragile and coagulated and fractured. In Comparative Example 12, since the adhesive did not contain the blocked isocyanate C2, the adhesive layer was cured when the resin film was laminated. Therefore, the resin film and the metal plate could not be sufficiently brought into close contact with each other. From this, it was clarified that the resin laminated metal plate according to the present embodiment can exhibit a strong adhesive force between the metal plate and the resin film, and can maintain and express the advanced design of the resin film. In addition, in order to confirm the difference in the lamination temperature, the same test as in Example 1 was carried out except that the lamination temperature of Example 1 was set to 200 ° C. As a result, the evaluation item of the embossed shape was Δ, and the other evaluation items were /. Therefore, it was also found that when the heating temperature exceeds 180 ° C., the resin laminated metal plate according to the present embodiment cannot be obtained.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person having ordinary knowledge in the field of technology to which the present invention belongs can come up with various modifications or modifications within the scope of the technical ideas described in the claims. , These are also naturally understood to belong to the technical scope of the present invention.

Claims (12)

With a metal plate
An adhesive layer laminated on at least one side of the metal plate,
A resin film laminated on the adhesive layer is provided.
The adhesive layer contains a cured product of the adhesive and contains.
The adhesive comprises the following components (a) to (e), a 30 sec gel fraction 10 to 55 percent when heated at 140 ° C., after 30 seconds heating at 140 ° C., 5 at 40 ° C. A resin laminated metal plate characterized in that the gel content becomes 70% or more after being held for a day or heated at 230 ° C. for 30 seconds.
(A) Polyester resin A having a Tg of 30 to 80 ° C.
(B) Polyester resin B having a Tg of -30 to 20 ° C.
(C) Block isocyanate C1 having a dissociation temperature of 100 to 120 ° C.
(D) Block isocyanate C2 having a dissociation temperature of 140 to 160 ° C.
(E) Polyisocyanate compound D With a metal plate
An adhesive layer laminated on at least one side of the metal plate,
A resin film laminated on the adhesive layer is provided.
The adhesive layer contains a cured product of the adhesive and contains.
The adhesive contains 100 parts by mass of the following (a), 30 to 150 parts by mass of the following (b), and 1 to 50 parts by mass of the following (c) and (d) in total, and the following ( It is seen containing a curing agent comprising e) at a ratio of 30 to 80 parts by weight, and a 30 sec gel fraction 10 to 55 percent when heated at 140 ° C., 30 seconds after heating at 140 ° C., 40 ° C. A resin laminated metal plate characterized in that the gel content becomes 70% or more after being held for 5 days or heated at 230 ° C. for 30 seconds.
(A) Polyester resin A having a Tg of 30 to 80 ° C.
(B) Polyester resin B having a Tg of -30 to 20 ° C.
(C) Block isocyanate C1 having a dissociation temperature of 100 to 120 ° C.
(D) Block isocyanate C2 having a dissociation temperature of 140 to 160 ° C.
(E) Polyisocyanate compound D The resin film is composed of a plurality of or a single layer of a film layer.
The resin laminated metal plate according to claim 1 or 2, wherein the softening temperature of the film layer in contact with the adhesive layer is less than 150 ° C. The resin laminated metal plate according to claim 1 or 2, wherein the resin film is composed of a plurality of or a single layer of a film layer, and at least the uppermost layer of the film layer is a biaxially stretched film. The resin laminated metal plate according to any one of claims 1 to 4, wherein the adhesive contains 10 to 50 parts by mass of epoxy resin E with respect to 100 parts by mass of the polyester resin A. The resin laminated metal plate according to any one of claims 1 to 5, wherein the adhesive contains 1 to 30 parts by mass of a silane coupling agent F with respect to 100 parts by mass of the polyester resin A. .. The resin laminated metal plate according to any one of claims 1 to 6, wherein the adhesive contains 1 to 30 parts by mass of polycarbonate diol G with respect to 100 parts by mass of the polyester resin A. The metal plate and the resin film are bonded to each other via an adhesive heated to 180 ° C. or lower.
The adhesive comprises the following components (a) to (e), a 30 sec gel fraction 10 to 55 percent when heated at 140 ° C., after 30 seconds heating at 140 ° C., 5 at 40 ° C. A method for producing a resin laminated metal plate, characterized in that the gel content becomes 70% or more after being held for a day or heated at 230 ° C. for 30 seconds.
(A) Polyester resin A having a Tg of 30 to 80 ° C.
(B) Polyester resin B having a Tg of -30 to 20 ° C.
(C) Block isocyanate C1 having a dissociation temperature of 100 to 120 ° C.
(D) Block isocyanate C2 having a dissociation temperature of 140 to 160 ° C.
(E) Polyisocyanate compound D An adhesive laminating step of forming an adhesive layer on a metal plate by laminating the adhesive on at least one surface of the metal plate.
A heating step of heating the metal plate on which the adhesive layer is formed to 180 ° C. or lower, and
A resin film laminating step of laminating the resin film on the adhesive layer,
The method for producing a resin laminated metal plate according to claim 8, further comprising a cooling step of cooling the metal plate on which the resin film is laminated to room temperature. The metal plate and the resin film are bonded to each other via an adhesive heated to 180 ° C. or lower.
The adhesive contains 100 parts by mass of the following (a), 30 to 150 parts by mass of the following (b), and 1 to 50 parts by mass of the following (c) and (d) in total, and the following (e). look containing a curing agent comprising 30 to 80 parts by weight, a gel fraction when heated 30 seconds at 140 ° C. 10 to 55% after 30 seconds heating at 140 ° C., at 40 ° C. 5 days holding or 230 A method for producing a resin laminated metal plate, characterized in that the gel content after heating at ° C. for 30 seconds is 70% or more.
(A) Polyester resin A having a Tg of 30 to 80 ° C.
(B) Polyester resin B having a Tg of -30 to 20 ° C.
(C) Block isocyanate C1 having a dissociation temperature of 100 to 120 ° C.
(D) Block isocyanate C2 having a dissociation temperature of 140 to 160 ° C.
(E) Polyisocyanate compound D An adhesive laminating step of forming an adhesive layer on a metal plate by applying an adhesive on at least one side of the metal plate.
A heating step of heating the metal plate on which the adhesive layer is formed to 180 ° C. or lower, and
A resin film laminating step of laminating a resin film on the adhesive layer, and
The method for producing a resin laminated metal plate according to claim 10, further comprising a cooling step of cooling the metal plate on which the resin film is laminated to room temperature. The method for producing a resin laminated metal plate according to any one of claims 8 to 11, wherein the heating temperature of the adhesive is 160 ° C. or lower.