JP2009172917A - Sublimating dye transfer printing coated metal plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent oozing-out of a printing pattern caused by laminating a film using an adhesive agent on a coated metal plate wherein a clear coating layer is formed on a substrate metal plate and a sublimating dye is permeated through the clear coating layer by transferring of the sublimating dye to form a transferred pattern. <P>SOLUTION: In the metal plate, an acrylic resin containing 15 mass% or less of an oligomer having an average weight molecular weight of 400,000 or more, a glass transition point of -20°C or lower and an average weight molecular weight by GPC of 5,000 or less is used as an adhesive agent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is used for full-color outdoor advertising billboards, decorative flooring, outer plates of furniture and cooking utensils, etc., and is coated with a weather-resistant and resistance-resistant film laminated on the surface of a coated metal plate on which a transfer pattern is formed with a sublimation dye. The present invention relates to a sublimation dye transfer printing coated metal plate having excellent wear characteristics.

  When manufacturing metal plates for transfer printing using sublimation dyes, sublimation dyes are printed on the clear top coat of coated metal plates by printing methods such as offset, silk, gravure and transfer, and sublimation dyes are applied by heat treatment. The clear coating is infiltrated. For example, a method in which a transfer sheet is brought into contact with a curable resin layer and heated (Patent Document 1), a printing layer is formed on a coated metal plate by transfer printing using a sublimation dye, and then a top coating is laminated. A method of infiltrating a sublimable dye from the inside of a coating film by heat treatment (Patent Document 2), a method of infiltrating a heat sublimable ink into a coating film of a prepaint steel plate provided with a primer coating film and a colored top coating film (Patent Document 3) ), A method of infiltrating a sublimation colorant into an opaque resin layer on a metal plate (Patent Document 4), and the like.

  The sublimable dye is an effective dye for forming a printed pattern with high definition. However, it is a disperse dye or oil-based dye having a small polarity, and is easily denatured by a plasticizer or an organic chemical, and is easily decomposed or discolored by being irradiated with light such as ultraviolet rays. For this reason, it is difficult to maintain vivid colors and patterns in outdoor use environments that are exposed to sunlight for a long period of time.

  Accordingly, the present inventors have conducted various investigations and studies on coating films that suppress the deterioration, discoloration, and discoloration of sublimation dyes. As a result, it was formed from a paint in which a thermosetting polyester resin having a number average molecular weight of 1000 to 10000 was a main component and an isocyanate curing agent was blended at a ratio of 10 to 50 parts by mass with respect to 100 parts by mass of the resin solid content. It has been clarified that when a coating film is used for a dye-receiving layer, a transfer printing coated metal sheet having improved weather resistance can be obtained (Patent Document 5).

Japanese Patent Laid-Open No. 51-24313 JP 54-104907 A JP-A-7-31931 Japanese Patent Laid-Open No. 7-102733 JP 2003-285001 A

In all the conventional printing methods using sublimation dyes, a pattern is formed by penetrating a sublimation dye into a clear coating film. Sublimation dyes are usually disperse dyes or oil dyes having a small polarity, and are easily altered by plasticizers, organic chemicals, and the like.
In addition, sublimation dyes are decomposed by light such as ultraviolet rays and electric lamps, causing discoloration or discoloration. Therefore, it is difficult to maintain stable colors and patterns of these dyes in an environment where they are exposed outdoors for a long period of time.

  As described in Patent Document 5, by changing the molecular weight, crosslinking density, and glass transition temperature of the coating film serving as the dye-receiving layer, the sublimation dyes can be prevented from being altered, discolored, and faded to some extent. However, further improvement is necessary to achieve further long-term durability. For example, when a conventional transfer-printed metal sheet is exposed to the outdoors for more than 5 years, the color tone change of the colored portion becomes ΔE> 15, and the deterioration of the printed pattern cannot be ignored.

  As a means for improving weather resistance and abrasion resistance, a means of laminating a clear film having a high ultraviolet absorption effect on a dye receiving layer dyed with a sublimation dye is also conceivable. In such a method, a clear film is attached to a transfer printing coated metal plate using an adhesive, but the sublimation dye is present in the adhesive layer present at the interface between the dye receiving layer into which the sublimation dye has penetrated and the clear film. It spreads and the printed pattern spreads within a short time, resulting in a decrease in sharpness. In this respect, it has not been practical to improve weather resistance and wear resistance by laminating a clear film.

However, laminating with a clear film can significantly improve weatherability and wear resistance. For this reason, the inventors of the present application have made extensive studies focusing on improving the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer which causes the above-mentioned problems.
As a result, a clear coating layer is provided on the base metal plate, and a sublimation dye penetrates into the clear coating layer by transfer of the sublimation dye to form a transfer pattern, and further has a laminate film layer thereon. It was found that bleeding of sublimable dyes can be solved by using a specific pressure-sensitive adhesive in the pressure-sensitive adhesive layer used at the interface between the laminate film layer and the clear coating layer in the coated metal plate.

  Specifically, the sublimation dye transfer printing coated metal plate of the present invention is provided with a clear coating layer on the base metal plate, and the transfer pattern is formed by the sublimation dye penetrating into the clear coating layer by the transfer of the sublimation dye. Is a coated metal plate having a laminate film layer thereon, and an adhesive layer is present between the clear coating layer and the laminate film layer, and the adhesive layer has a weight average molecular weight of 400, It is characterized in that it is formed of an acrylic resin having an oligomer content of 5,000 or more, a glass transition temperature of -20 ° C. or less, and a weight average molecular weight by GPC of 5,000 or less.

  The sublimation dye transfer printing coated metal plate of the present invention can prevent bleeding of the printed pattern due to the use of an adhesive. As a result, it is possible to use a film that can be protected from ultraviolet rays and the like, and even when exposed to the outdoors for a long period of 5 years or longer, the transfer pattern is hardly discolored. Excellent in properties.

Detailed embodiments of the sublimation dye transfer printing coated metal plate of the present invention will be described with reference to the drawings.
In the sublimation dye transfer printing coated metal plate of the present invention, a base coating 2 and a clear coating 3 are overlaid on a base metal plate 1 (Drawing 1). After forming the dye coloring layer 4 which dye | stained only the base coating film 2 and the clear coating film 3, or the clear coating film 3 with a sublimation dye, the adhesive layer 5 is provided on it and the laminate film layer 6 is further formed. In order to improve the corrosion resistance, a primer layer 7 having a rust preventive pigment may be provided between the base metal plate 1 and the base coating film 2.

The material of the base metal plate 1 is not particularly limited, but a plated steel plate, a stainless steel plate, a cold-rolled steel plate, an aluminum plate, or the like is used. Prior to the formation of the base coating film 2 or the primer layer 7, pre-coating treatments such as degreasing, washing, replacement treatment, and chemical conversion treatment are appropriately performed.
The base coating film 2 is preferably a white coating film having a thickness of 10 to 20 μm. If the film thickness is less than 10 μm, the color tone of the underlying metal plate 1 may not be sufficiently shielded. Further, if the film thickness is 20 μm or more, there is a concern about pinhole-like coating film defects (hereinafter referred to as “waki”) due to bumping of the solvent remaining in the coating film during baking.

  The clear coating film 3 is not particularly limited in its material as long as it is a dyeable resin that receives a sublimation dye and is dyed appropriately. Examples thereof include polyester resin, acrylic resin, urethane resin, vinyl resin, acrylic-urethane resin, silicone-polyester resin, and silicone-acrylic resin.

It is preferable to add an ultraviolet absorber to the clear coating film 3 in order to prevent discoloration of the sublimation dye and reduction in gloss of the coating film under ultraviolet irradiation. As ultraviolet absorbers, organic ultraviolet absorbers such as benzotriazole-based and triazine-based compounds are known, but mass reduction is 10% by mass or less under heating conditions of 5 ° C./min in the air atmosphere. Are preferred. Considering the absorption characteristics, UV absorption in a wide wavelength range can be expected when benzotriazole and triazine compounds are used in combination. Further, an inorganic ultraviolet absorber capable of converting ultraviolet rays into heat or long wavelength light such as ultrafine zinc oxide and titanium oxide can be used.
These ultraviolet absorbers are preferably used in an amount of 0.1 to 6 parts by mass with respect to 100 parts by mass of the coating resin used for the clear coating film 3. If the amount is less than 0.1 parts by mass, a sufficient ultraviolet absorption effect may not be obtained. If the amount exceeds 6 parts by mass, the ultraviolet absorber may bleed on the surface of the coating film.
Further, when a hindered amine light stabilizer is added, the weather resistance of the clear coating film 3 is further improved.

  When silica, glass, nylon, urea resin, acrylic resin, fluorine resin, polyethylene resin, polypropylene resin, or the like is dispersed in the clear coating film 3, a coating film having a matte appearance is provided. When flakes such as carbon black, graphite, metal oxide, metal sulfide and the like are dispersed to adjust the lightness, a coating film having a calm appearance is obtained.

  The clear coating film 3 preferably has a film thickness of 6 μm or more in order to allow a sufficient amount of sublimation dye to permeate and develop a printed pattern. If it is less than 6 μm, a satisfactory color tone may not be imparted due to insufficient penetration of the sublimable dye. The upper limit of the film thickness is not particularly limited, but is adjusted to a film thickness that does not cause coating film defects such as cracks when the clear top coat is baked.

  The pressure-sensitive adhesive layer 5 is formed of an acrylic resin. As the monomer used here, acrylic acid, methacrylic acid and esters thereof are used. Examples of (meth) acrylic acid esters include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, iso-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, iso-octyl acrylate, lauryl acrylate, stearyl acrylate Acrylic acid esters such as; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, iso-octyl methacrylate, methacrylic acid esters such as lauryl acrylate and stearyl acrylate Etc. Moreover, regarding the above monomer, a monomer substituted with a substituent such as a hydroxyl group, an epoxy group and a halogen atom can also be used.

In addition to the above monomers, hydroxyl group, epoxy group, alkoxy group, ethylene oxide group, amino group, amide group, carboxyl group, halogen atom, phosphoric acid group, sulfonic acid, silane group, urethane group, phenyl group, benzyl group, tetrafur A vinyl monomer having a furyl group can be used in combination.
The acrylic resin used in the pressure-sensitive adhesive layer 5 may be a polymer obtained by combining these monomers and different monomers.

The pressure-sensitive adhesive layer 5 uses a crosslinking agent in addition to the acrylic resin. The crosslinking agent is not particularly limited as long as it is generally used as a crosslinking agent when an acrylic resin is used as an adhesive. Examples include acridine compounds, polyisocyanate compounds such as aliphatic diisocyanates and aromatic diisocyanates, melamine compounds such as butyl etherified styrene melamine, epoxy resin compounds, metal salts and the like.
The amount of the crosslinking agent used is generally 0.05 to 10 parts by mass with respect to 100 parts by mass of the acrylic resin solid content.

  The adhesive layer 5 further contains additives such as a tackifier resin, a silane coupling agent, an ultraviolet absorber, an antioxidant, a light stabilizer, a plasticizer, a softening agent, a dye, a pigment, and an inorganic filler as necessary. Can be made.

As the tackifier resin, a compound having a hydroxyl group can be used. Specific examples thereof include esterified products of rosin compounds. Examples of the rosin compound include rosin monomer, rosin dimer, disproportionated rosin, hydrogenated rosin, and these compounds. The esterified product of the rosin compound is obtained by esterifying a polyhydric alcohol with the rosin compound. Examples of the polyhydric alcohol include diethylene glycol, glycerin, and pentaerythritol.
In addition, a resin containing no hydroxyl group can also be used as a tackifier resin, for example, petroleum resins such as C5 (aliphatic) and C9 (aromatic), terpene resins, xylene resins, and styrene resins. These modified phenolic compounds can also be used. Furthermore, a rosin compound which is not esterified can also be used.

  The acrylic resin of the pressure-sensitive adhesive layer 5 has a glass transition temperature of −20 ° C. or lower. When the glass transition temperature is higher than −20 ° C., fluidity as a pressure-sensitive adhesive in a low temperature range is hindered. Therefore, the adherend (clear coating film 3 and laminate film layer 6) is particularly applied at the time of bonding during winter. As a result, wetting with respect to the surface becomes worse and sufficient adhesive strength cannot be obtained. Further, if the glass transition temperature of the acrylic resin is −20 ° C. or more, bleeding of the sublimable dye becomes a problem, and color unevenness occurs.

  The glass transition temperature here refers to a dynamic viscoelasticity measuring device “DVA200” (manufactured by IT Measurement Control Co., Ltd.), rapidly cools the sample to −150 ° C., and then increases to 200 ° C. at a temperature rising rate of 10 ° C./min. The temperature is raised, the viscoelasticity is measured at a vibration frequency of 10 Hz, and the peak value of tan δ is determined as the glass transition temperature (Tg).

The pressure-sensitive adhesive layer 5 uses an acrylic resin having a weight average molecular weight of 400,000 or more. This weight average molecular weight is measured by gel permeation chromatography (hereinafter abbreviated as “GPC”). GPC is a polymer gel porous material packed in a chromatography column. Depending on the size of the porous material and the molecular weight of the material to be measured, molecules can penetrate or be excluded. The molecular weight distribution of a polymer substance is measured by utilizing the phenomenon. Usually, it is expressed as a relative value in terms of polystyrene based on standard polystyrene.
And the adhesive layer 5 uses the acrylic resin which contains 15 mass% or less of oligomers of the weight average molecular weight 5000 or less of polystyrene conversion.
When the weight average molecular weight is less than 400,000 or when an acrylic resin containing more than 15% by mass of an oligomer having a polystyrene equivalent weight average molecular weight of less than 5000 is used for forming the adhesive layer, the clear coating film 3 The penetrated sublimation dye oozes out to the pressure-sensitive adhesive, and the printing pattern bleeds and the color uniformity is impaired.

In general, the thickness (when dried) of the pressure-sensitive adhesive layer 5 is preferably set to 10 to 100 μm from the viewpoints of pressure-sensitive adhesive performance (adhesive strength, tack, holding power) and coatability.
As a means for applying the pressure-sensitive adhesive when forming the pressure-sensitive adhesive layer 5, a commonly used coating apparatus such as a roll knife coater, a die coater, a roll coater, a bar coater, a gravure roll coater, a reverse roll coater, Use dipping, blade coater, etc.

A release sheet may be provided on the pressure-sensitive adhesive layer 5 after the pressure-sensitive adhesive layer 5 is formed and before the laminate film layer 6 is formed.
This release sheet has a supporting force and has a release layer on the surface that can be released from the pressure-sensitive adhesive layer. For example, use a paper, plastic, non-woven fabric, synthetic fiber, or a base material made of paper and plastic having a polyethylene layer on at least one side and a release agent such as silicone resin laminated on the polyethylene layer. be able to. In addition, a polyethylene terephthalate base material having a release agent laminated on at least one surface can be used.
Furthermore, the pressure-sensitive adhesive layer 5 of the present invention is provided on a release substrate, and this is laminated on a film to be a laminate film layer, and used as a pressure-sensitive adhesive film for lamination in the production of a sublimation dye transfer printing coated metal plate of the present invention. You can also.

The material of the laminate film layer 6 is not particularly limited. For example, polyolefin resin, fluorine resin, acrylic resin, vinyl chloride resin, polyester resin and the like can be mentioned.
Specific examples of fluororesins include tetrafluoroethylene copolymer, ethylene-4 fluoroethylene copolymer, hexafluoropropylene-4 fluoroethylene copolymer, perfluoroalkyl vinyl ether-4 fluoroethylene copolymer. A vinylidene difluoride copolymer, a trifluoride ethylene polymer, a monofluoroethylene copolymer, a chloroethylene trifluoride polymer, or a copolymer or a mixture thereof can be used.
From the viewpoints of mechanical properties, film formability, workability, etc., it is preferable to use a fluororesin using an ethylene-4 fluoroethylene copolymer or a hexafluoropropylene-4 fluoroethylene copolymer. Further preferred is a tetrafluoroethylene copolymer. Further, a fluororesin mainly composed of ethylene-4 fluoroethylene copolymer is preferred, and this main component means that ethylene-4 fluoroethylene copolymer is contained in an amount of 50% by mass or more in the resin solid content, Preferably it is 70 mass% or more. In addition to this, other resins can be added, for example, a polyolefin resin and an acrylic resin can be added.

  When an acrylic resin is used for the laminate film layer 6, the monomers used are methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, iso-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, lauryl acrylate. , Stearyl acrylate, iso-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, phenoxyethyl acrylate, and the like; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate , 2-ethylhexyl methacrylate, n-octyl methacrylate DOO, lauryl methacrylate, stearyl methacrylate, iso- nonyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, methacrylic acid esters such as phenoxyethyl methacrylate.

  When an acrylic resin film is formed using a monomer such as the (meth) acrylic acid ester, mass polymerization, solution polymerization, 0.001 to 5 parts by mass of a polymerization initiator with respect to 100 parts by mass of the monomer, A film is formed by polymerization by a known method such as emulsion polymerization or suspension polymerization. Among these, it is preferable to carry out by solution polymerization.

A film such as an acrylic resin can be produced by a T-die extrusion method, a calendar method, a cast method, or the like. In the T-die extrusion manufacturing method, a film can be manufactured by heating and melting a resin such as an acrylic resin to a temperature equal to or higher than the melting point, extruding from a thin slit-like gap called a T-die, cooling, and winding.
In addition, in the calendering method, a film can be produced by heating and melting to a temperature equal to or higher than the melting point of a resin such as an acrylic resin, and extending it thinly and flatly with a heat roll called a calender roll, and then cooling and winding up. it can.

As the laminate film layer 6, it is preferable to use a fluororesin film and an acrylic resin film from the viewpoints of transparency of the film, bleeding of sublimation dyes, and outdoor durability.
In addition, the laminate film layer 6 can contain additives such as an ultraviolet absorber, an antioxidant, a light stabilizer, a plasticizer, and a softener as necessary.

The film thickness of the laminate film layer 6 is not particularly limited, but is generally 20 to 200 μm, particularly preferably 50 to 200 μm. If the film thickness is less than 20 μm, the film strength is not sufficient, so that it is difficult to laminate and wrinkles are likely to occur. Moreover, when it becomes larger than 200 micrometers, curved surface workability will worsen.
Further, when the film thickness is 50 μm or more, both the ultraviolet shielding effect that can maintain the color tone change of ΔE15 or less even after 5 years of outdoor exposure and the effect of preventing the sublimation dye from being eluted outside the film. Can be combined.

The film surface of the laminate film layer 6 can be subjected to surface treatment or undercoating treatment. Such surface treatment or undercoating treatment can be expected to improve adhesion to the pressure-sensitive adhesive layer 5, improve water resistance, and the like.
For example, corona discharge treatment (in air, nitrogen, carbon dioxide, etc.), plasma treatment (high pressure, low pressure), alkali metal solution treatment, high frequency sputter etching treatment, or the like is used. In the case of surface treatment, the treatment strength is not particularly limited and can be a desired value. However, as a measure of the treatment strength, the surface wetness index of the film measured based on JIS-K-6768 is 35 dyn / cm. As mentioned above, Preferably it is 40 dyn / cm or more.

Manufacture thickness of coated steel plate used for transfer master plate: After degreasing and surface-adjusting 0.5mm galvanized steel plate, apply white chromate coating with a coating amount of 15μm after dry coating. The white base coating film 2 was formed by baking at a plate temperature of 220 ° C. for 1 minute.
Next, the clear paint was applied onto the white base coating film 2 in such an application amount that a clear coating film 3 having a dry film thickness of 18 μm was formed.

As a clear paint, a polyester resin having a number average molecular weight of 3000 was a main component, and melamine was blended at a ratio of 60 parts by mass per 100 parts by mass of the resin solid content. Furthermore, 8 parts by mass of a 1: 1 mixture of a triazine-based UV absorber (manufactured by Ciba Geigy: TINUVIN 400) and a benzotriazole-based UV absorber (manufactured by Ciba-Geigy: TINUVIN 384), a hindered amine light stabilizer (Ciba-Geigy) 1.5 parts by mass of TINUVIN 123) manufactured by the company was added.
After coating, the clear coating film 3 having a dry film thickness of 18 μm was obtained by baking at a plate temperature of 230 ° C. for 1 minute.

Production of Transfer Sheet A cyan dye (PTB31 (CI Disperse blue 26): manufactured by Mitsubishi Chemical Corporation) was used as the sublimation dye.
Using an inkjet printer (manufactured by Mimaki Engineering Co., Ltd.) and an inkjet recording paper (S-COAT2: manufactured by Marking Magic Co., Ltd.) with an inkjet image printing system (Grades System: manufactured by Marking Magic Co., Ltd.) A cyan solid pattern was added. Next, a black dye (PTA33 (blend): manufactured by Mitsubishi Chemical Corporation) was used to output "center line" characters (Heisei Kaku Gothic, points: 8), and prepared a transfer sheet with black characters on a cyan background. .

Transfer metal sheet 11, transfer sheet 12, heat-resistant cushion 13 (thickness 1 mm Conex felt: made by Teijin Ltd.) from the hot plate 10 side so that the dye printing surface of the transfer sheet is aligned with the coating film of the transfer-printed steel sheet And sandwiched between a smooth hot plate 10 and a rubber sheet 14 (FIG. 2).
After setting the coated metal plate 11, the transfer sheet 12, and the like, the whole was vacuum-sucked to 80 kPa, and the transfer sheet 12 was brought into close contact with the coated steel plate 11 with a negative pressure. In this state, it was heated to 160 ° C. for 5 minutes, and after completion of the pressure bonding, the transfer sheet 12 was peeled from the coated metal plate 11.

Creation of Laminate Film Layer 6 (1) Fluorine Film (a) Molding of Base Material for Film Formation Molecular weight 200,000, elution amount at each temperature by cross fractionation method is 68.9% by mass at 0-10 ° C., 10 Polypropylene resin (manufactured by Tokuyama Co., Ltd.) that was 10.9 mass% at -70 ° C, 1.33 mass% at 70-95 ° C, and 18.9 mass% at 95-125 ° C was used as a raw material. Extrusion molding was performed by a T-die extrusion manufacturing method to obtain a film forming base material made of a polypropylene resin film having a thickness of 50 μm.
(B) Preparation of fluororesin coating material Binder (made of 2-ethylhexyl acrylate-acrylic acid-vinyl acetate copolymer to 50% by mass of fluororesin consisting of vinylidene fluoride-4 fluoroethylene-6 fluoroethylene copolymer) 100 parts by mass of fluororesin paint (fullerene) manufactured by Nippon Synthetic Rubber Co., Ltd. mixed with 50% by mass of acrylic resin, and 5 parts by mass of benzotriazole organic ultraviolet absorber (TINUVIN 384-2 manufactured by Ciba Geigy) A fluororesin paint was prepared by blending.
(C) Formation of coating film The coating material obtained in (b) was applied to one surface of the base material for film formation obtained in (a) so as to have a dry thickness of 60 μm and dried.

(2) Formation of Acrylic Resin Film 100 parts by mass of acrylic resin (Mitsubishi Rayon Co., Ltd., Dianar BR-75), 2 parts by mass of benzotriazole-based UV absorber (manufactured by Ciba Specialty Chemicals, Tinuvin 900) And mixed. An acrylic resin film having a thickness of 150 μm was obtained from this mixture by a T-die extrusion method. This acrylic resin film was wound up with a tension of 2 N / cm in the longitudinal direction in the cooling process. The acrylic resin film obtained here had a glass transition temperature of 89 ° C.

Preparation of adhesive (Example 1) (Example 1)
1 kg of a mixture containing 95 parts by mass of n-butyl acrylate, 5 parts by mass of acrylic acid, 0.02 parts by mass of lauryl mercaptan and 80 parts by mass of ethyl acetate (as a solvent) was added to a stirrer, a reflux condenser, a thermometer, and dropwise. A five-necked flask equipped with a funnel and nitrogen gas inlet was charged. After stirring and dissolving in the flask, it was purged with nitrogen gas for about 30 minutes to remove oxygen dissolved in the mixture.
Then, the temperature inside the flask was replaced with nitrogen gas, and the temperature was raised and maintained at 70 ° C., and 0.05 part by weight of benzoyl peroxide as a thermal polymerization initiator was dissolved in 3 ml of ethyl acetate. It was dripped by. The reaction started, and the reaction was carried out at the same temperature for 10 hours to obtain an acrylic copolymer liquid.

  N, N-hexamethylene-1,6-bis (1-aziridinecarboxamide) (manufactured by Mutual Yakuhin Co., Ltd .: trade name “HDU” as a crosslinking agent with respect to 100 parts by mass of the solid content of the acrylic copolymer solution ] 0.14 parts by mass, 1.5 parts by mass of a benzotriazole-based ultraviolet absorber (Tinuvin 900) and 20 parts by mass of a special rosin ester (trade name “Superester A-115” manufactured by Arakawa Chemical Co., Ltd.) as a tackifier resin A pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 5 was obtained.

The pressure-sensitive adhesive was applied on the fluororesin film so that the thickness after drying, that is, the thickness of the pressure-sensitive adhesive layer 5 was 30 μm, and then dried at 110 ° C. for 3 minutes. An adhesive film having a laminate film layer 6 was obtained.
This adhesive film was laminated on the printed surface of the coated metal plate on which transfer printing was performed.

(Example 7)
A pressure-sensitive adhesive film having a pressure-sensitive adhesive layer 5 and a laminate film layer 6 after applying a corona discharge treatment to the pressure-sensitive adhesive-coated surface of the acrylic resin film and applying and drying the pressure-sensitive adhesive to a dry thickness of 30 μm. Got.
This adhesive film was laminated on the printed surface of the coated metal plate on which transfer printing was performed.

(Example 2)
96 parts by mass of n-butyl acrylate, 4 parts by mass of acrylic acid, and 0.05 parts by mass of lauryl mercaptan were used as the adhesive, and styrene petroleum resin (trade name “FTR6100” manufactured by Mitsui Petrochemical Co., Ltd.) was used as the tackifier. The procedure was the same as in Example 1 except that the amount was 20 parts by mass.
(Examples 3-6, 8, Comparative Examples 1-4)
Regarding Examples 3 to 6 and Comparative Examples 1 to 4, the pressure-sensitive adhesive having the composition as shown in Table 1 was used, an adhesive film was prepared in the same manner as in Example 1, and the coated metal plate subjected to transfer printing was used. Laminated on the printed surface.

^１）紫外線吸収剤はチヌビン９００
コロネールＬはイソシアネート系架橋剤（日本ポリウレタン工業株式会社製）

¹⁾ UV absorber is Tinuvin 900
Coronale L is an isocyanate crosslinking agent (manufactured by Nippon Polyurethane Industry Co., Ltd.)

In this example, HLC8820 (manufactured by Tosoh Corporation) was used as the weight average molecular weight, and the content of oligomers having a molecular weight of 5000 or less was calculated from the molecular weight distribution in terms of polystyrene based on standard polystyrene using tetrahydrofuran as a dissolving agent. Specific measurement conditions are as follows.
Measuring device: HLC8820GPC (manufactured by Tosoh Corporation)
Column: TSKgel GMHXL (manufactured by Tosoh Corporation)
Solvent: Tetrahydrofuran Flow rate: 0.5 ml / min
Temperature: 40 ° C
Sample concentration: 0.1% by mass
Sample injection volume: 100 μl

Performance Evaluation of Transfer Printing Painted Metal Sheet Each of the manufactured transfer printing coated metal sheets was subjected to a weather resistance test, a coating adhesion test, a printed character visibility test, and a print pattern color deterioration test.

  In the weather resistance test, using a sunshine carbon arc weather meter with a black panel set at a temperature of 63 ° C., the color of the cyan solid pattern printed part was measured after 2000 hours under the condition that fresh water was sprayed for 12 minutes during irradiation for 60 minutes, A color difference ΔE was determined in comparison with an unirradiated test piece. Color difference ΔE: Weather resistance was evaluated with と し て being less than 10, ○ being 10-15, Δ being 15-20, and x being 20 or more. If the weather resistance evaluation is Δ or more, it can be said that it is a coated steel plate that can be used practically.

In the coating film adhesion test, an adhesive film corresponding to the laminate film layer 6 and the adhesive layer 5 was used.
SP adhesive strength According to JIS Z0237, SUS304 No. 4 Adhesive film was bonded to the surface finish with a width of 20 mm. This was left at 23 ° C. for 20 minutes, and then the 180 ° peel strength was measured. The tensile speed was 300 mm / min.

90 ° peel retention (120 ° C)
No. of SUS304 after alkali degreasing 4 Adhesive film was bonded to the surface finish with a width of 20 mm at room temperature. After leaving this at 120 ° C. for 20 minutes, a load of 100 g was applied to peel it in the direction of 90 °, and the peel distance per unit time was measured.

In the visibility of printed characters, the color unevenness of the cyan solid part is visually observed, the test piece where the outline of the printed character has become unclear is ×, the test piece that is slightly blurred but has no visibility problem is Δ, the outline Visibility was evaluated with a test piece in which printed characters could be clearly read without blurring.
In the color tone degradation test of the printed pattern, the cyan solid portion was visually observed, and a test piece in a uniform dyeing state without color unevenness was evaluated as “◯”, and a test piece in which color unevenness occurred and dyeing was uneven was evaluated as “x”.

As can be seen from the results in Table 2, Examples 1 to 8, which are products of the present invention, exhibited excellent weather resistance, and coating film adhesion, letter printing visibility, and color tone uniformity of the printed pattern were also good. .
In Comparative Example 1, the visibility of character printing and the color tone uniformity of the printed pattern were acceptable, but the adhesiveness of the adhesive film was insufficient. Other comparative examples had problems with the visibility of printed characters and the uniformity of color tone.

It is a model figure of the sublimation dye transfer printing painting metal plate of this invention. It is explanatory drawing of the sublimation transfer method which made the transfer sheet closely_contact | adhere to the coating metal plate by negative pressure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base metal plate 2 Base coating film 3 Clear coating film 4 Dye coloring layer 5 Adhesive layer 6 Laminating film layer 7 Primer layer 10 Hot plate 11 Painted metal plate 12 Transfer sheet 13 Heat-resistant cushion 14 Rubber sheet H Heat input P Pressure

Claims (3)

  A coated metal plate having a clear coating layer formed on a base metal plate, and a sublimation dye penetrating into the clear coating layer by transfer of the sublimation dye to form a transfer pattern, and further having a laminate film layer thereon An adhesive layer exists between the clear coating layer and the laminate film layer, and the adhesive layer has a weight average molecular weight of 400,000 or more, a glass transition temperature of −20 ° C. or less, and a weight average molecular weight by GPC. A sublimation dye transfer printed metal sheet excellent in weather resistance and abrasion resistance, which is formed of an acrylic resin having a content of oligomers of 5,000 or less of 15% by mass or less.   The said laminated film layer is a sublimation dye transfer printing coating metal plate excellent in the weather resistance and abrasion resistance of Claim 1 formed with the film containing a fluororesin or an acrylic resin.   The sublimation dye transfer printing painting metal plate excellent in the weather resistance and abrasion resistance of Claim 2 in which the said fluororesin contains 50 mass% or more of ethylene-tetrafluoroethylene copolymers in a resin component.

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