JP2958083B2 - Resin coated metal - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin-coated metal obtained by laminating a fluorine-based resin film on a metal surface by thermal fusion.

[Conventional technology]

Conventional resin-coated metal is formed by forming a fluorine-based resin layer on the surface of a metal base such as aluminum, and thereby forming a heat-resistant, chemical-resistant, electrical and mechanical property of the fluorine-based resin layer on the metal. It is known to have been given the selected attribute.

[Problems to be solved by the invention]

However, the conventional resin-coated metal fluororesin can be kneaded with a coloring component such as a pigment to color the entire resin in the same color, but in general, decoration, display characters, figures, etc. are colored by printing. Therefore, there is a problem that it is extremely difficult to display characters, figures, and the like on a resin-coated metal by coloring.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resin-coated metal in which the display contents such as characters and graphics displayed on the surface of the metal are robust and hard to peel off.

[Means for solving the problem]

The present invention is characterized in that a fluororesin film having a printing layer formed by an ink resin composition is heat-sealed on a metal surface, and the ink resin composition contains a crosslinking agent. The above object has been achieved by providing a resin-coated metal described above.

Hereinafter, the present invention will be specifically described with reference to FIG.

FIG. 1 is a partial sectional view schematically showing a resin-coated metal according to one embodiment of the present invention.

The resin-coated metal of the present embodiment is a resin-coated metal plate, on which a fluororesin film 3 having a printing layer 2 formed of an ink resin composition is thermally fused on the surface of a metal 1.

The metal plate 1 is not limited to a specific material, and can be appropriately selected from the materials described below as needed.
Usually, it is preferable to use aluminum or an aluminum-based alloy. Also, the thickness of the metal plate 1 is not particularly limited, and an appropriate thickness can be selected as needed.

In addition, the printing layer 2 is formed of the fluororesin film 3
The printing layer 2 may be formed on any one of the two surfaces of the fluororesin film 3, but may be in contact with the metal plate 1. In order to protect the printed layer 2 from abrasion or the like, it is preferable that the printed layer 2 be formed on the back surface of the fluororesin film 3 on the side to be coated. Further, the thickness of the printing layer 2 is not particularly limited, and is usually preferably 1 to 100 μm. Further, the fluorine-based resin film 3 can be appropriately selected from conventionally known materials described below as needed. The thickness is not particularly limited, and is usually 5
〜1000 μm is preferred.

Next, the metal plate, the ink resin composition and the fluororesin film will be described in more detail.

As described above, the metal material forming the metal plate 1 can employ various metals. Among them, aluminum alone or various aluminum alloys such as duralumin, and aluminum metal containing a small amount of manganese, magnesium or the like can be used. Aluminum-based metals are preferred. Others
Iron-based metals, copper-based metals, titanium-based metals and the like can also be preferably used. The surface of the metal plate 1 is cleaned (degreasing and the like) or roughened (sand blasting, etc.) in order to improve the adhesion to the fluororesin film 3.
It is preferable to perform a surface treatment such as chemical etching in advance.

The ink resin composition forming the printing layer 2 contains a crosslinking agent and contains a resin binder as a main component. Examples of the resin binder include a fluorine-based resin binder and an acrylic-based resin binder, and a fluorine-based resin binder is preferable (the resin binder will be mainly described with respect to the fluorine-based resin binder). The ink resin composition contains a solvent, a thixotropy-imparting agent, a pigment (or a dye), and other various additives as required, in addition to a resin binder and a crosslinking agent.

The fluororesin binder is not particularly limited, but the fluororesin binder is usually a difluoroethylene-tetrafluoroethylene-hexafluoropropylene copolymer resin, a difluoroethylene-hexafluoropropylene copolymer resin, a difluoroethylene-tetra A fluoroethylene copolymer resin is preferred, and a difluoroethylene-tetrafluoroethylene-hexafluoropropylene copolymer resin is particularly preferred. Other fluorine resin binders generally have a fluorine content of
30% by weight or more, particularly preferably 40% by weight or more, for example, ethylene-tetrafluoroethylene-based copolymer,
Ethylene-chlorotrifluoroethylene-based copolymer, hexafluoropropylene-tetrafluoroethylene-based copolymer, perfluoroalkylvinyl ether-tetrafluoroethylene copolymer, polyvinylidene fluoride, polyvinyl fluoride, and the like are preferable. Among them, a fluoroolefin, cyclohexyl vinyl ether, an ethylene-tetrafluoroethylene-based copolymer containing an essential component of an alkyl vinyl ether and a hydroxyalkyl vinyl ether is preferable, and further, a fluoroolefin,
The content of units based on cyclohexyl vinyl ether, alkyl vinyl ether, hydroxyalkyl vinyl ether and other comonomers is 40 to 60 mol%,
45 mol%, 5 to 45 mol%, 3 to 15 mol% and 0 to 30 mol%, and in an uncured state in tetrahydrofuran.
Those having an intrinsic viscosity of 0.1 to 2.0 dl / g measured at 30 ° C. are preferred. Further, in the above fluorocopolymer, the fluoroolefin is a perhaloolefin such as chlorotrifluoroethylene or tetrafluoroethylene, and the alkyl vinyl ether contains a linear or branched alkyl group having 2 to 8 carbon atoms. More preferably, the hydroxyalkyl vinyl ether is hydroxybutyl vinyl ether.

The cross-linking agent crosslinks the fluorine-based resin binder when the fluorine-based resin film 3 is thermally fused to the metal plate 1. By cross-linking the resin binder, the cross-linking agent forms the printing layer 2. By increasing the strength of the printed layer 2 and increasing the adhesive strength to the fluororesin film 3 and the metal plate 1,
Is to make it more difficult to peel off from the fluororesin film 3 and the metal plate 1.

As the cross-linking agent, for example, OH cross-linkable polyols, amine cross-linkable organic amines, and peroxide cross-linkable peroxides are preferably used.

The polyols used for the OH crosslinking type have no so-called scorch trouble, which cures during storage of the fluororesin binder, have a high crosslinking rate, and are excellent as a crosslinking agent. As the polyol, for example,
Bisphenol, bisphenol AF (hexafluoroisopropylidene bisphenol) and the like are preferably used. If necessary, an acid acceptor such as magnesium oxide, zinc oxide or calcium hydroxide for removing an acid generated during crosslinking is added to the polyols.

Further, the organic amines used in the amine cross-linking type have a high cross-linking rate, but have a scorch trouble. Therefore, it is necessary to add an anti-scorch agent and also to add the acid acceptor. As the organic amines, for example, hexamethylenediamine, hexamethylenediaminecarbamate (HMDAc), tylenediaminecarbamate, N, N'-dicinnamylidene-1,6-hexanediamine (DCHDA) and the like are preferably used.

In addition, the peroxides used for the peroxide crosslinking type do not necessarily require an acid acceptor, and the fluorine-containing resin binder can be constituted by a CC bond having a stable crosslinking point. As the peroxides, for example, benzoyl peroxide, dicumyl peroxide and the like are preferably used.

Further, the content of the crosslinking agent with respect to the fluorine-based resin binder is preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, and still more preferably 3 to 10 parts by weight based on 100 parts by weight of the resin.

Further, the melt flow index of the ink resin composition is preferably from 1 to 500, more preferably from 20 to 400,
30-300 is more preferred. If the melt flow index is less than 1, the adhesion to the metal plate 1 at the stage of heat fusion described below is unfavorably reduced, and if it is more than 500, printing of characters, figures, and the like is undesirably blurred.
Incidentally, the melt flow index is a solid content of the ink resin composition excluding the solvent component, and is an index representing the fluidity of the thermoplastic resin at the time of melting, for example, using a descending flow tester, Temperature 300 ℃, load 30kg / cm
Extrude a 1 g sample from a nozzle with a nozzle diameter of 1 mm and a land of 2 mm under ^{2, and} express the volume of the molten sample extruded per unit time at that time. The above temperature is the temperature of the sample resin (fluorine resin). The temperature is within a temperature range in which the melt molding process is possible (the temperature range between the flow start temperature and the thermal decomposition start temperature) and close to the flow start temperature.

The solvent is preferably one having a boiling point of 100 to 200 ° C., for example, the following ones are preferred.

Aliphatic hydrocarbons; mineral spirits aromatic hydrocarbons; xylene, solvent naphtha, tetralin, dipentene, toluene alcohols; cyclohexyl alcohol, 2-methylcyclohexyl alcohol esters; butyl acetate ketones; cyclohexanone, methylcyclohexanone, diacetone alcohol, Isophorone glycols; ethylene glycol, propylene glycol glycol ethers; methyl cellosolve (ethylene glycol monomethyl ether), cellosolve (ethylene glycol monoethyl ether), butyl cellosolve, carbitol glycol ether ester; cellosolve acetate, butyl cellosolve acetate, carbitol acetate (diethylene glycol) Monoethyl ether acetate) Amides; Gandolfo formamide and dimethylacetamide, as the thixotropy-imparting agents, colloidal silica (Aerosil # 400), aluminum alcoholates, organic bentonite, aluminum chelate, and barium sulfate.

The ink resin composition preferably has a thixotropy index (TI value) of 2 to 8, more preferably 3 to 7, and still more preferably 4 to 6. The TI value was determined by using the BH viscometer at a temperature of 25 ° C., using a No. 7 rotor, and measuring the ratio of the viscosity N ₂ to N ₂₀ at 2 and 20 rotations, ie, TI = N ₂ Indicated by / N ₂₀ .

In addition, the above pigment or dye is appropriately selected and used depending on the purpose and use.

Examples of the pigment include an inorganic pigment, an organic pigment, and an extender pigment. As inorganic pigments, titanium oxide, carbon black, red iron oxide, iron black, navy blue, ultramarine, zinc white, graphite, chrome vermilion, cobalt blue, calcined green, zinc nitrate, bronze powder, aluminum powder, pearl pigment, etc. It is preferably used, and as the organic pigment, insoluble azo azo lakes, quinacridone red, carmine red,
Watching red, condensed azo red, perylene red, anthraquinone, disazo orange, dinitroaniline orange, acetron orange, disazo yellow, hansa yellow, acetron yellow, chlorinated phthalocyanine, brillian green lake, phthalocyanine, indathrene blue, di Oxazine violet, methyl violet, fluorescent pigments, fluorescent pigments and the like are preferably used, and as the extender, precipitated barium sulfate, calcium carbonate, alumina white, clay and the like are preferably used.

Further, as the above-mentioned dyes, ordinary acid dyes, basic dyes, oil-soluble dyes, and disperse dyes are used. As the oil-soluble dyes, azo-based, triarylmethane-based, anthraquinone-based, and azine-based dyes are used. .

As other additives, conventionally known gelling agents, thickeners, antioxidants, defoaming agents, matting agents, ultraviolet absorbers, light stabilizers are used. A curing catalyst such as aerfossonium chloride is used.

The above-mentioned ink resin composition is composed of the above-described components, and a preferable blending ratio of each component is, with respect to 100 parts by weight of a fluororesin binder, 50 to 150 parts by weight of a solvent and 2 to 10 parts by weight of a thixotropy-imparting agent. To this, an appropriate amount of pigment or dye (usually 10 to 400 parts by weight) and other additives are added according to the purpose and application, and if necessary, a curing catalyst is added.
1 to 2 parts by weight can be added. In addition, at the time of compounding each component, each component and the amount thereof are appropriately selected such that the melt flow index of the obtained resin composition is 1 to 500.

Examples of the fluororesin forming the fluororesin film 3 include an ethylene-tetrafluoroethylene-based copolymer, an ethylene trifluoride copolymer, a vinylidene fluoride copolymer, a vinyl fluoride polymer, and a fluorine-containing resin. Alkoxyethylene resin, ethylene tetrafluoride resin, tetrafluoroethylene-propylene hexafluoride copolymer and the like are preferable, and furthermore, ethylene-tetrafluoroethylene copolymer is more preferable,
Among them, four in the molar ratio of the content of fluorinated ethylene / ethylene 40 / 60-60 / 40, and the general formula _{CH 2 = CH-C n F} 2n + 1 ( where integer n in formula 2-10 a content of perfluoroalkyl vinyl monomer is 0.1 to 10 mole% represented by the a), a melt flow index 10 to 500 mm ³
/ S is preferred. When the melt flow index is in this range, it is possible to obtain a good resin-coated metal that does not peel off because the adhesive strength of the fluororesin film 3 to the metal plate 1 increases. In addition, the said melt flow index is measured similarly to the case of the said fluororesin composition.

The method for producing the resin-coated metal is not particularly limited, and any method can be employed. For example, a fluorinated resin film 3 on which a printing layer 2 is formed in advance with the ink resin composition is prepared, and the fluorinated resin film is coated with the printing layer 2.
The resin-coated metal of the present invention can be manufactured by heat-sealing the surface of the metal plate 1 on which the surface treatment has been performed, with the inside facing. Further, in this case, the fluorine-based resin film may be thermally fused to the metal plate with the printing layer 2 facing outward. The resin-coated metal of the present invention can also be produced by heat-sealing the fluorine-based resin film to the surface of the metal plate 1 on which the printing layer 2 has been formed in advance with the ink resin composition.

The method of forming the printing layer 2 on the fluororesin film 3 is not particularly limited as long as it is a means capable of forming a thin film of the ink resin composition in close contact. There are a method of forming the print layer 2 by printing on the resin film 3 and a method of directly printing the ink resin composition on the metal plate 1.

Hereinafter, a specific method for forming the printing layer 2 on the fluororesin film 3 will be described.

As the fluorine-based resin film 3, for example, a thickness of 5 to
A screen having a size of 1000 μm is used, and as a screen used for screen printing, for example, a screen having an opening of 100 to 300 mesh is used so that a thin film (printing layer 2) of an ink resin composition having a thickness of 1 to 100 μm can be obtained. To

Prior to printing the ink resin composition on the fluororesin film 3, the fluororesin film 3
The surface is preferably subjected to a corona discharge treatment, a plast treatment, a sodium etching treatment, or the like, and is activated so that the surface has a wetting index of, for example, 35 dynes or more.

Thus, in order to obtain the printing layer 2 of the resin-coated metal by screen printing, the above-described ink resin composition is printed on the fluorine-based resin film 3 treated as described above using the above-described screen in a conventional manner. Good. that time,
If the thixotropy of the ink resin composition is less than 3, inconveniences such as poor plate cutting and stringing may occur. If the thixotropy exceeds 8, there may be inconveniences such as generation of screen mesh and decrease in self-leveling property.

The fluororesin film 3 having the printed layer 2 formed on one surface as described above is placed on the surface of the metal plate 1 which has been subjected to a predetermined surface treatment with the printed layer 2 inside, and
The resin-coated metal of the present invention is produced by heating to 60 ° C. and heat-sealing.

In the present invention, since the ink composition forming the printing layer 2 contains a predetermined amount of a crosslinking agent and the melt flow index of the solid material is adjusted to 1 to 500, the ink composition is heat-fused as described above. In this case, the printing pattern shape can be maintained sharply, and at the same time, the robust printing layer 2
Can be thermally fused to the surface of the metal plate 1.

Therefore, according to the present invention, when the fluorine-based resin film 3 is heat-sealed to the surface of the metal plate 1, the fluorine-based resin binder in the ink resin composition is cross-linked by the cross-linking agent, and characters, figures, etc. Can be obtained by obtaining a resin-coated metal on which a printed layer 2 which is robust and hard to peel off is formed.

The resin-coated metal of the present invention is not limited to the metal plate 1 described above, and may be of any form as long as the fluorine-based resin film is heat-sealed.

[Action]

ADVANTAGE OF THE INVENTION According to the resin-coated metal of this invention, a fluororesin film fuse | melts firmly to a metal and it is difficult to peel off from a metal, and also a strong printing layer can be formed.

〔Example〕

Next, the present invention will be described more specifically based on the following examples.

Example 1 First, a difluoroethylene-tetrafluoroethylene-hexafluoropropylene copolymer resin (Kyner 930)
1: Mitsubishi Yuka Co., Ltd.) was dissolved in a mixed solvent of isophorone and cyclohexane at the following ratio.

Kainer 9301; 100 g isophorone; 75 g cyclohexanone; 75 g Next, the above resin solution was prepared by dispersing and kneading a composition prepared by adjusting the following components to have the following ratio by an ink mill to prepare a crosslinkable ink resin composition.

(A) Kyner 9301; 100 g (b) Cyanine blue; 50 g (c) Colloidal silica; 10 g (d) Barium sulfate; 5 g (e) Bisphenol AF; 5 g (f) Magnesium oxide; 5 g (g) Hardening catalyst; 2 g The thixotropic index of the ink resin composition was 6.

Using the above ink resin composition, 50 μm ethylene-
After screen printing on the entire surface of a tetrafluoroethylene copolymer resin (Aflon COP: manufactured by Asahi Glass Co., Ltd.) using a 225 mesh screen,
Hot air drying was performed at 0 ° C. for 60 minutes. When the thickness of the print layer of this film was measured, the thickness was 8 μm.

The printed film thus obtained was subjected to a method shown in each of Japanese Patent Application Nos. 1-73899 and 1-139155 to form an aluminum plate having a thickness of 2 mm (JIS A3004 grade).
Was heat-sealed to produce a product 1 of the present invention.

Example 2 A product 2 of the present invention was produced in the same manner as in Example 1 except that Tekinoflon TN50 (manufactured by Asahi Mont Co., Ltd.) was used instead of the Kynar 9301 in Example 1.

Example 3 A vinylidene fluoride resin (Kyner 301F) was used instead of Kyner 9301 in Example 1, and a mixed solvent of isophorone-
Product 3 of the present invention was produced using methyl ethyl ketone instead of cyclohexanone.

Example 4 A product 4 of the present invention was produced using an acrylic resin-containing ink adjusted to have the following orientation ratio.

(A) acrylic resin; 100 g (b) titanium oxide; 20 g (c) colloidal silica; 5 g (d) hexamethylene diisocyanate; 2 g Note that isophorone-cyclohexanone is used as a solvent, and 2-ethylhexia is used as the acrylic resin. An acrylate-ethyl acrylate-vinyl acetate-acrylamide copolymer was used.

Taber abrasion for each of the present invention products 1 to 4,
Each test of weather resistance and bending workability was performed, and each was evaluated according to the following criteria. Each evaluation result is shown in Table 1 below.

As is clear from the results shown in Table 1 below, it was found that all of the products 1 to 4 of the present invention were excellent in Taber abrasion, weather resistance and bending workability.

In Table 1, Taber abrasion, weather resistance and bending workability are evaluated according to the following criteria.

Taber abrasion: A wear test was performed using a wear tester specified in JIS-K7204 under the conditions of a load of 500 gf and a number of rotations of 1,000. ◎ is good, Δ is slightly bad, and × is bad.

Weather resistance: Accelerated exposure test for 5,000 hours was performed using WS type sunshine carbon (manufactured by Suga Test Instruments) indicated in JIS A1415-1977, and the appearance change was compared with that of the storage test piece.
The case where the appearance was not substantially different from the appearance of the storage test was indicated by ◎, and the case where the appearance was slightly changed was indicated by ○.

Bendability: A steel round bar having a diameter of 2 mm is arranged at the center of a test piece having a length of 100 mm, a width of 50 mm, and a thickness of 2 mm, and the round bar is used as a fulcrum.
An 80 ° bending process was performed. At that time, the presence or absence of cracks / separation occurring in the bent portion was examined.

〔The invention's effect〕

The resin-coated metal of the present invention has strong display contents such as characters and figures displayed on the surface of the metal and is hard to peel off.

[Brief description of the drawings]

FIG. 1 is an enlarged partial sectional view showing an example of the resin-coated metal of the present invention. DESCRIPTION OF SYMBOLS 1 ... Metal plate 2 ... Printing layer 3 ... Fluorine resin film

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B32B 15/08

Claims (5)

(57) [Claims] 1. A method according to claim 1, wherein a fluorine-based resin film having a printing layer formed by the ink resin composition is heat-sealed to the surface of the metal, and the ink resin composition contains a crosslinking agent. Characterized resin-coated metal. 2. The resin-coated metal according to claim 1, wherein the printing layer is interposed between the fluororesin film and the surface of the metal. 3. The resin-coated metal according to claim 1, wherein said ink resin composition has a melt flow index of 1 to 500. 4. The resin-coated metal according to claim 1, wherein said ink resin composition contains a fluorine-based resin composition as a main component. 5. The resin-coated metal according to claim 1, wherein said metal is aluminum or an aluminum-based alloy.