KR20120135417A - Black metal sheet - Google Patents

Abstract

Although the film thickness of the black coating film (black layer) which coat | covers the metal plate surface is thin, specifically, even if the adhesion amount of a black coating film (black layer) is 0.28-1.5 g / m <^2> (film thickness: about 0.26-1.42 micrometers), The black metal plate which exhibits the high blackness which hides the hue and gloss of a metal plate is provided. The black metal plate of this invention has a metal plate and the black layer formed in the at least single side | surface of the said metal plate, The said black layer is 22-60 mass parts of surface-treated carbon black by which surface was coat | covered with water-soluble resin, and binder resin 20-73 It consists of 100 mass parts black composition containing a mass part, The dry mass of the said black layer is 0.28-1.5 g / m <^2> , The blackness (L * value) of the said black layer surface is 24 or less, It is characterized by the above-mentioned.

Description

Black metal plate {BLACK METAL SHEET}

The present invention relates to a black metal plate excellent in blackness.

In recent years, as a back cover of thin televisions, such as liquid crystal televisions and plasma televisions, steel sheets coated with a black coating film instead of black plastic (PCM: precoat metal) in view of cost reduction and conductivity (electromagnetic wave countermeasure) to the inner surface side. ) Is increasing. However, the conventional PCM has a coating amount of carbon black as a black pigment in order to conceal the appearance and gloss of the original plate (electro galvanized steel sheet, hot dip galvanized steel sheet, alloyed hot dip galvanized steel sheet, etc.) to express black color. It had to apply so that it might be set to about 12 g / m <^2> (about 10 micrometers in thickness), and it had a problem that it took a long time for coating and baking. Therefore, from the viewpoint of streamlining the painting work and saving the resources, thinning of the black coating film (black layer) has been desired.

Until now, various PCMs with the thin film thickness of a black coating film (black layer) are disclosed, For example, in this patent applicant, the patent applicant 1 has a film thickness of 0.4-3 micrometers in the original whose blackness (L value) is 56 or less. The black metal plate which formed the black coating film is disclosed.

However, in the black metal plate of patent document 1, blackness (L value) was 30.1 minimum, and sufficient blackness could not be exhibited.

Japanese Patent Publication No. 2001-9966

The present invention has been made in view of the above circumstances, and an object of the present invention is that, even if the film thickness of the black coating film (black layer) covering the metal plate surface is thin, specifically, the deposition amount of the black coating film (black layer) is 0.28. Even if the thickness is about 1.5 g / m ² (approximately 0.26 to 1.42 μm), the black metal plate exhibits a high blackness that conceals the color tone and gloss of the metal plate, and provides a black metal plate excellent in adhesion between the metal plate and the black coating film (black layer). It is in doing it.

The black metal plate of this invention which could solve the said subject has a metal plate and the black layer formed in the at least single side | surface of the said metal plate, The said black layer is 22-60 mass parts of surface-treated carbon black by which the surface was coat | covered with water-soluble resin, It consists of 100 mass parts black composition containing 20-73 mass parts of binder resins, The dry mass of the said black layer is 0.28-1.5 g / m <^2> , and the blackness (L * value) of the said black layer surface is 24 or less. It is characterized by.

In this specification, "surface-treated carbon black with which the surface was coat | covered with water-soluble resin" includes not only the aspect which coat | covered the whole surface of carbon black with water-soluble resin, but the aspect in which the one part was coat | covered. In addition, an L * value is a value converted from the brightness indicator L value measured by the method prescribed | regulated to JIS Z 8722 by Formula (1) mentioned later.

In this invention, it is a preferable embodiment that the said binder resin is a polyethylene resin and / or a polyurethane resin. Specifically, the polyethylene resin is composed of an olefin-α, β-unsaturated carboxylic acid copolymer, an α, β-unsaturated carboxylic acid polymer, and an oxazoline group-containing polymer, and the oxazoline group-containing polymer is olefin-α, It is preferable to contain 2-8 mass parts with respect to a total of 100 mass parts of a (beta)-unsaturated carboxylic acid copolymer and the (alpha), (beta)-unsaturated carboxylic acid polymer. The polyurethane resin is a carboxyl group-containing polyurethane resin and is selected from the group consisting of tolylene diisocyanate, diphenylmethane diisocyanate and dicyclohexyl methane diisocyanate. A urethane prepolymer composed of at least one polyisocyanate component and a polyol component containing a 1,4-cyclohexanedimethanol, a polyether polyol and a polyol having a carboxyl group is obtained by a chain extension reaction. It is preferable.

Moreover, the said black composition is prepared by adding the said binder resin to the aqueous solution containing carbon black and the said water-soluble resin, and contains 5-20 mass parts of colloidal silica further in 100 mass parts of said black compositions. It is also a preferred embodiment.

Moreover, the said metal plate is a base layer in which at least one surface was previously formed by undertreatment, The said underlayer is dry mass 12 ~ by the undertreatment composition containing aluminum phosphate, colloidal silica, and polyacrylic acid. It is also a preferred embodiment to be formed to be 117 mg / m ² . It is preferable that the content ratio of aluminum phosphate and colloidal silica in the said base treatment composition is aluminum phosphate: colloidal silica (mass ratio) = 35: 65-65: 35, and polyacrylic acid is a heavy acid aluminum and a colo It is preferable to contain 0.2-1.0 mass part with respect to a total of 100 mass parts of silica this month. Moreover, it is also preferable to contain 3-15 mass parts of silane coupling agents with respect to a total of 100 mass parts of aluminum heavy acid acid and colloidal silica further in the said base treatment composition.

Moreover, it is also a preferable embodiment on the said black layer that a clear layer is 1-4 g / m <^2> in dry mass, and blackness (L * value) of the surface of the said clear layer is 24 or less. The clear resin composition forming the clear layer comprises: i) a weight average molecular weight of 10,000 to 25,000, Tg 35 to 75 ° C, and a hydroxyl group containing a polymer polyester resin of 5 mgKOH / g or more, ii) a weight average molecular weight of 10,000 Polymer polyester resin of -25,000, Tg 35-75 degreeC, and low molecular weight polyester resin of weight average molecular weights 1,500-2,500, Tg 10-45 degreeC are polymeric polyester resin: Low molecular polyester resin (mass ratio) = 8: 2 to 6: 4 containing a mixed resin having an average hydroxyl value of 25 mgKOH / g or more, iii) weight average molecular weight 30,000 ~ 40,000, Tg -3 ~ 23 ℃, hydroxyl group 10mgKOH a polyester urethane resin having a / g or less, or iv) a polyester urethane resin having a weight average molecular weight of 30,000 to 40,000 and a Tg -3 to 23 ° C, a low molecular weight of 1,500 to 2,500 and a Tg of 10 to 45 ° C. Polyester resin, polyester urethane resin: Low molecular weight It is preferable that the average hydroxyl group formed by mixing with polyester-based resin (mass ratio) = 2: 8-4: 6 contains the mixed resin whose 25 mgKOH / g or more. Moreover, also preferable embodiment which contains 2-10 mass parts of polyethylene wax further in 100 mass parts of said clearing resin compositions, and contains 5-20 mass parts of rust inhibitors further in 100 mass parts of said clearing resin compositions. to be.

In the present invention, since the surface-treated carbon black coated with the water-soluble resin is used as the black pigment, the black pigment is mixed with the binder resin as compared with the case where the carbon black whose surface is not coated with the water-soluble resin is used as the black pigment. When it is obtained, it exhibits excellent dispersibility and is difficult to secondary aggregate. For this reason, the black layer formed using the black composition comprised including such surface treated carbon black and binder resin can exhibit high blackness, As a result, even if the application amount of the black composition to a metal plate is suppressed low ( Even if the film thickness of a black layer is made thin), the black metal plate which has the outstanding blackness can be obtained. Furthermore, rationalization and resource saving of a painting work can be aimed at.

Therefore, according to the present invention, even if the film thickness of the black coating film (black layer) covering the surface of the metal plate is thin, high blackness concealing the color tone and gloss of the metal plate is exhibited, and the metal plate and the black coating film (black layer) The black metal plate excellent in adhesiveness can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the relationship between the adhesion amount of the black layer formed using surface-treated carbon black, and the blackness (L * value) of a black metal plate.
FIG. 2 is a diagram showing the relationship between the adhesion amount of the black layer formed using the untreated carbon black and the blackness (L * value) of the black metal plate.
It is a figure which shows the relationship between b value (yellowing) of surface-treated carbon black density | concentration, and a black metal plate.
It is a figure which shows the relationship between the surface-treated carbon black density | concentration and the blackness (L * value) of a black metal plate.
It is a figure which shows the relationship of surface treatment carbon black density | concentration and b value (yellowing) of the black metal plate in which the clear layer was provided.
6 is a graph showing the relationship between the surface treated carbon black concentration and the blackness (L * value) of a black metal plate provided with a clear layer.
It is a figure which shows the relationship between the clear-layer adhesion amount, the glossiness, and blackness of a black metal plate.

The black metal plate of this invention has a metal plate and the black layer formed in the at least single side | surface of the said metal plate, The said black layer is 22-60 mass parts of surface-treated carbon black by which surface was coat | covered with water-soluble resin, and binder resin 20-73 It consists of 100 mass parts black composition containing a mass part, The dry mass of the said black layer is 0.28-1.5 g / m <^2> , The blackness (L * value) of the said black layer surface is 24 or less, It is characterized by the above-mentioned. Hereinafter, the black metal plate of this invention is demonstrated concretely.

(plate)

The metal plate used in the present invention is not particularly limited as long as it is used as an original plate of precoat metal. For example, an aluminum plate, a titanium plate, etc. other than steel plates, such as an unplated cold rolled steel plate, a hot dip galvanized steel plate (GI), an alloying hot dip galvanized steel plate (GA), an electrogalvanized steel plate (EG), etc. are mentioned. Among these, a hot dip galvanized steel sheet (GI), an electrogalvanized steel sheet (EG), an aluminum plate, and a titanium plate are preferable.

It is preferable that the said metal plate formed the base layer by the base process at least on one side previously. For example, the adhesiveness of a metal plate and a black layer improves if it has the chemical conversion film layer formed in the surface treatment of the metal plate. As such a chemical conversion film layer (base layer), a chromate film layer, an organic film layer, an inorganic film layer, a phosphate film layer, etc. are mentioned. Among these, the chromate coating layer may be a reactive chromate coating or a coating chromate coating. In particular, in the case of the coating chromate coating, phosphoric acid, colloidal silica and organic resin may be added to further improve the corrosion resistance. As the organic coating layer, for example, a polyethylene resin, an epoxy resin, an acrylic resin, a urethane resin, a polyester resin, a fluorine resin, a mixture thereof, a copolymer, a modified resin, or the like may be appropriately selected and used. Furthermore, for the purpose of improving corrosion resistance, silica gel, colloidal silica, etc. are added to the said organic film, for the purpose of improving the workability after applying a coating film, for the purpose of adding a trace amount of various wax components, or for improving coating film adhesiveness, A silane coupling agent can also be added. As an inorganic film layer, a silicate film layer etc. are mentioned. In addition, phosphoric acid or fluoride may be added to the silicate coating layer.

Although the adhesion amount of a chromate coating layer is not specifically defined, It is preferable to set it as 5 mg / m <^2> or more from a corrosion resistance viewpoint. However, exceeding 300 mg / m < ² > saturates the improvement effect of corrosion resistance, and raises manufacturing cost. Regarding the deposition amount of the organic coating layer and the inorganic coating layer, for the same reason as the chromate coating layer, it is preferably 0.5 g / m ² or more and 20 g / m ² or less.

In particular, the base layer is being acid aluminum, colloidal silica, and the poly 12 and not dry mass by treatment with a composition comprising the acrylic acid 117mg / m ² (more preferably 20mg / m ² or more, 80mg / m ² or less, More preferably 40 mg / m ² or more and 80 mg / m ² or less). When this specific base treatment composition is applied to a galvanized metal plate, the surface of the metal plate is etched by hydrogen ions derived from aluminum phosphate, and the black layer described later by the interaction of aluminum ions derived from aluminum phosphate and colloidal silica. It is possible to form a poorly water-soluble coating having excellent adhesion to the top coat such as a water-based clear layer for backing or backing, and as a result, the film adhesion after bending or press working (elongation and shrinkage deformation) is improved, and thus corrosion resistance and resistance to corrosion are improved. The tape peeling property can be greatly improved. If the adhesion amount of the base layer formed of a specific base treatment composition is less than 12 mg / m <^2> by dry mass, since it will become difficult to uniformly cover the surface of a metal plate with a poorly soluble film, the effect of improving the corrosion resistance and adhesiveness with a top coat is sufficient. When it becomes difficult to express and, on the contrary, exceeds 117 mg / m ² , the effect of improving corrosion resistance is recognized, but the amount of remaining aluminum acid which does not react (etch) with the surface of the metal plate increases, and colloidal which does not contribute to adhesion As a result of the increase in the amount of silica, the effect of improving the adhesion with the top layer may be low, or the adhesion of the underlying layer to the metal plate may be lowered. On the other hand, according to such an adhesion amount, the film thickness of an underlayer is about 0.007-0.07 micrometers normally.

The content ratio of aluminum phosphate and colloidal silica in the said specific base treatment composition is aluminum phosphate: colloidal silica (mass ratio) = 35: 65-65: 35 (more preferably 40 / 50-60 / 50) Is preferably. When colloidal silica is more than the said ratio, film-forming property will fall and a base layer will become difficult to form, and the improvement effect of corrosion resistance and adhesiveness with a top coat will become difficult to be acquired, and also adhesiveness with respect to a metal plate will also be low. It may become a coating film peeling after processing. On the other hand, when colloidal silica is less than the said ratio, since the ratio of aluminum phosphate increases, the ratio of the residual aluminum acid which does not react (etch) with a metal plate will melt | dissolve in water, causing corrosion under a coating film, and corrosion resistance. It may fall.

In the said specific base treatment composition, it is preferable that polyacrylic acid is contained 0.2-1.0 mass part (more preferably 0.4 mass part or more, 0.8 mass part or less) with respect to a total of 100 mass parts of aluminum heavy acid and colloidal silica. . Polyacrylic acid is considered to play a role of appropriately controlling the reaction (etching) of the surface of the metal plate (zinc plating) subjected to zinc plating and the like, and if the content is less than 0.2 part by mass, the etching occurs excessively, resulting in corrosion resistance. If the amount exceeds 1.0 parts by mass, the etching is inadequate, and the poorly soluble coating formed by the heavy acid acid and the colloidal silica is not sufficiently formed, and the effect of improving the adhesion and the corrosion resistance becomes difficult to be obtained.

In the said specific base treatment composition, 3-15 mass parts (more preferably 5 mass parts or more and 12.5 mass parts or less) containing a silane coupling agent further with respect to a total of 100 mass parts of aluminum heavy acid and colloidal silica. It is also preferable to. When the silane coupling agent is less than 3 parts by mass, the effect of improving the adhesion to the top plate and the metal plate and the corrosion resistance tends to be insufficient, which may result in peeling of the film under harsher processing conditions, and conversely, even if it exceeds 15 parts by mass. Moreover, corrosion resistance and adhesiveness may fall.

(Surface treatment carbon black)

In the present invention, the black pigment constituting the black composition is instead of carbon black (a carbon black whose surface is not covered with a water-soluble resin, hereinafter sometimes referred to simply as "untreated carbon black"), which has been conventionally used. It is characterized by the use of carbon black (surface treated carbon black) whose surface is coated with a water-soluble resin. When untreated carbon black is used, it is necessary to increase the thickness of the black layer (to increase the amount of deposition) in order to sufficiently exhibit the blackness of the obtained black metal plate (to realize L * value of 24 or less) (Fig. 2) By using the surface treated carbon black, a black metal plate having excellent blackness can be obtained even if the film thickness of the black layer is made thin (even if the amount of adhesion is reduced) (FIG. 1).

By using surface-treated carbon black instead of untreated carbon black, the detail of the mechanism by which the said effect is exhibited is unknown, but it thinks as follows. That is, when untreated carbon black is mixed with a binder resin to prepare a black composition, secondary aggregation easily occurs due to a change in pH, compatibility with the binder resin, or the like, and the coloring power of the black composition is low. For this reason, in order to obtain the black metal plate which has sufficient blackness, it is necessary to make the film thickness of a black layer thick (large adhesion amount). On the other hand, even if it mixes with a binder resin, surface-treated carbon black hardly produces secondary aggregation, and can maintain the high coloring power of a black composition. For this reason, even if the film thickness of a black layer is made thin (adhesion amount is reduced), the black metal plate excellent in blackness can be obtained.

The carbon black constituting the surface treated carbon black is not particularly limited, and examples thereof include cast carbon, smoke, commercially available coloring carbon black, and rubber carbon black. These carbon blacks can be produced by the direct powder method, the deep powder method, the channel method, the fastener method, the acetylene method, or the like. Specifically, MA-7, MA-100, # 970, # 2200, # 2600 (above, Mitsubishi Chemical Corporation make), special black-5, special black-100, color black S-170, printtex 140V (more than Acid carbon blacks such as Degussa Japan Co., Ltd.), Neospectra 1, Neospectra 5 (above, manufactured by Colombian Carbon Nippon Corporation); # 5, # 40, # 960, # 2300 (above, made by Mitsubishi Kasei Corporation), Printex 90, Printtex G, Printtex 45, Printtex L (above, made by Degusa Japan), RAVEN 420, RAVEN H20 Basic carbon black, such as POWDER (above, Colombian Carbon Nippon Corporation), etc. are mentioned. These carbon blacks may be used alone or in combination of two or more thereof.

The water-soluble resin which coats the surface of the carbon black is not particularly limited as long as it is difficult to secondaryly aggregate the carbon black in the binder resin. For example, gelatin, polyvinyl alcohol, polyvinylpyrrolidone, water-soluble acryl, acrylamide And vinylpyridine, polyacrylic acid and the like. These water-soluble resins may be used alone or in combination of two or more thereof. 5 mass parts or more are preferable with respect to 100 mass parts of carbon black, and, as for content of water-soluble resin, 380 mass parts or less are preferable. When content of water-soluble resin is less than 5 mass parts, secondary aggregation of surface-treated carbon black may not fully be suppressed in binder resin. Moreover, when content of water-soluble resin exceeds 380 mass parts, the viscosity of the black composition comprised using surface-treated carbon black may increase, and handling property may worsen.

Surfactant may be further attached to the surface-treated carbon black used by this invention. Thereby, secondary aggregation of the surface-treated carbon black in binder resin can be suppressed further. Examples of such surfactants include known anionic, nonionic, and cationic surfactants. Content of surfactant may be 0.5-130 mass parts with respect to 100 mass parts of carbon black.

Surface-treated carbon black contains 22 mass parts or more (preferably 25 mass parts or more, more preferably 30 mass parts or more) and 60 mass parts or less (preferably 50 mass parts or less) in 100 mass parts of black compositions. do. Since the surface-treated carbon black used in the present invention is hardly secondary to agglomeration even when mixed with a binder resin, even when the content thereof is 22 parts by mass or more, it can have a high dispersion stability to obtain a black composition having a higher coloring power. Can be. As a result, a black metal plate excellent in blackness can be obtained even if the deposition amount of the black composition is reduced (thin film thickness of the black layer).

When the content of the surface-treated carbon black is less than 22 parts by mass, the b value of the obtained black metal plate becomes high (over 1) (FIG. 3), showing blackish brown, and the blackness (L * value) cannot be 24 or less. There is a case (Fig. 4). In addition, when the content exceeds 60 parts by mass, the b value becomes low (below 1) (FIG. 3), and the black layer having a blackness (L * value) of 24 or less can be formed (FIG. 4), Since content of binder resin in a black composition reduces, it may become difficult to hold surface treated carbon black in a black layer. Moreover, a black composition may become easy to gelatinize, and liquid stability of a black composition may fall.

(Binder resin)

The binder resin used by this invention is fixing surface-treated carbon black in a black layer, 20 mass parts or more (more preferably 35 mass parts or more) are contained in 100 mass parts of black compositions, and 73 mass parts or less (more Preferably 70 mass parts or less, More preferably, it is 60 mass parts or less). When content of binder resin is less than 20 mass parts, the film forming property of a black layer may worsen, and fixing of surface treatment carbon black may become inadequate. Moreover, the scratch resistance of a black metal plate is inferior, a flaw becomes easy to be outstanding, and a visual problem may arise. When content of binder resin exceeds 73 mass parts, since the content of surface-treated carbon black reduces, the black metal plate which has the target blackness (L * value 24 or less) may not be obtained.

As binder resin used by this invention, if the surface treatment carbon black can be fixed in a black layer, the kind is not specifically limited, It is preferable to have a polyethylene resin and / or a polyurethane resin as a main component. According to the studies of the present inventors, it was found that the black composition obtained by using such a binder resin can effectively suppress secondary aggregation of the surface-treated carbon black, and is excellent in liquid stability.

Specifically, 45 mass parts of surface-treated carbon black, 45 mass parts of polyethylene resin, polyurethane resin, epoxy resin, or acrylic resin as a binder resin are mixed with 10 mass parts of colloidal silica, and a black composition is produced, respectively ( The details are described in Examples), and when this was applied and dried on an electrogalvanized steel sheet with a dry adhesion amount of 0.5 g / m ² , a black metal plate having a blackness of L * value of 24 or less was obtained. On the other hand, in the black composition which used acrylic resin and an epoxy resin as binder resin, the tendency for thickening was recognized with progress of time. On the other hand, in the black composition obtained using the polyurethane resin or the polyethylene resin, the thickening tendency was not recognized and showed favorable liquid stability.

When the particle size distribution (secondary particle diameter) of each black composition was measured, when an acrylic resin or an epoxy resin was used as binder resin, the volume average particle diameters were 13.05 micrometers and 14.35 micrometers, respectively, and the secondary particle diameter increased significantly. In contrast, in the case of using a polyethylene resin or a polyurethane resin, the volume average particle diameters were 2.82 μm and 4.46 μm, respectively, and a marked increase in the secondary particle size was not recognized. Therefore, stability with time of a black composition is considered to be largely influenced by the kind of binder resin.

<Polyethylene resin>

As a polyethylene resin used as binder resin, an olefin- (alpha), (beta)-unsaturated carboxylic acid copolymer (Hereinafter, it may be called "olefin-acid copolymer."), (Alpha), (beta)-unsaturated carboxylic acid polymer (Hereinafter, a "carboxylic acid polymer." And the oxazoline group-containing polymer. The olefin-acid copolymer and the carboxylic acid polymer do not impair the dispersion stability of the surface treated carbon black in the black composition and are excellent in compatibility with the carbon black. In addition, since the oxazoline group-containing polymer crosslinks with the olefin-acid copolymer and the carboxylic acid polymer to form a dense and very hard black layer, the surface-treated carbon black in the black layer is eluted by water wetness or the like on the black layer surface. Color separation) can be suppressed, and the scratchability of the surface of the black metal plate can also be improved.

In addition, the "olefin-acid copolymer" in this invention is a copolymer of an olefin and (alpha), (beta)-unsaturated carboxylic acid, and the structural unit derived from an olefin is 50 mass% or more (namely, (alpha), (beta)-) in a copolymer. It means that the structural unit derived from unsaturated carboxylic acid is 50 mass% or less). In addition, a "carboxylic acid polymer" is a polymer obtained by superposing | polymerizing using (alpha), (beta)-unsaturated carboxylic acid as a monomer, and means that the structural unit derived from (alpha), (beta)-unsaturated carboxylic acid is 90 mass% or more in a polymer. do.

`` Olefin-acid copolymer ''

The olefin acid copolymer used by this invention can be manufactured by copolymerizing an olefin and (alpha), (beta)-unsaturated carboxylic acid by a well-known method, and is commercially available. In the present invention, one or more olefin-acid copolymers may be used.

Although there is no restriction | limiting in particular as olefin which can be used for manufacture of an olefin acid copolymer, Ethylene, propylene, etc. are preferable and ethylene is more preferable. As the olefin-acid copolymer, any of olefin constituent units derived from only one olefin or those derived from two or more olefins can be used.

The alpha, beta -unsaturated carboxylic acid that can be used in the production of the olefin-acid copolymer is not particularly limited, and examples thereof include monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid and isocrotonic acid; And dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid. Among these, acrylic acid is preferable. As the olefin-acid copolymer, any of the constituent units of the?,? - unsaturated carboxylic acid may be derived from only one?,? - unsaturated carboxylic acid, or those derived from two or more?,? - unsaturated carboxylic acids .

The olefin-acid copolymer used in this invention may have a structural unit derived from another monomer in the range which does not adversely affect secondary aggregation suppression of surface treatment carbon black, etc. In the olefin-acid copolymer, the structural unit amount derived from the other monomer is preferably 10% by mass or less, more preferably 5% by mass or less, and the most preferred olefin-acid copolymer is olefin- and α. It consists only of a (beta)-unsaturated carboxylic acid. Ethylene-acrylic acid copolymer is mentioned as a preferable olefin-acid copolymer.

The (alpha), (beta)-unsaturated carboxylic acid in an olefin acid copolymer is used in order to improve the adhesiveness of a black layer and a metal plate, The amount of the (alpha), (beta)-unsaturated carboxylic acid in a copolymer becomes like this. Preferably it is 5 mass% or more, More preferably, it is more preferable. Preferably it is 10 mass% or more. However, when alpha, beta-unsaturated carboxylic acid becomes excess, since corrosion resistance may fall, the amount of alpha, beta-unsaturated carboxylic acid in a copolymer becomes like this. Preferably it is 30 mass% or less, More preferably, it is 25 mass% or less. .

The weight average molecular weight (Mw) of the olefin-acid copolymer used in the present invention is, in terms of polystyrene, preferably 1,000 to 100,000, more preferably 3,000 to 70,000, still more preferably 5,000 to 30,000. This Mw can be measured by GPC which uses polystyrene as a standard.

<< carboxylic acid polymer >>

As a carboxylic acid polymer used by this invention, the homopolymer or copolymer of 1 type, or 2 or more types of (alpha), (beta)-unsaturated carboxylic acid, or the copolymer which copolymerized another monomer further is mentioned. Such carboxylic acid polymers can be produced by a known method and are commercially available. In the present invention, one kind or two or more kinds of carboxylic acid polymers can be used.

As the α, β-unsaturated carboxylic acid that can be used for the production of the carboxylic acid polymer, any of the α, β-unsaturated carboxylic acids exemplified as those which can be used for the synthesis of the olefin-acid copolymer can be used. Among these, acrylic acid and maleic acid are preferable, and maleic acid is more preferable.

Although the carboxylic acid polymer may contain the structural unit derived from monomers other than (alpha), (beta)-unsaturated carboxylic acid, the structural unit amount derived from another monomer is 10 mass% or less in a polymer, Preferably it is 5 mass% or less The carboxylic acid polymer which consists only of (alpha), (beta)-unsaturated carboxylic acid is more preferable.

Examples of the preferred carboxylic acid polymer include polyacrylic acid, polymethacrylic acid, acrylic acid-maleic acid copolymer, polymaleic acid, and the like. Among these, polymaleic acid is more preferable from the viewpoint of black layer adhesiveness and the like. Since polymaleic acid has many carboxyl groups, the adhesiveness of a black layer and a metal plate improves.

The Mw of the carboxylic acid polymer used in the present invention is in terms of polystyrene, preferably 500 to 30,000, more preferably 800 to 10,000, still more preferably 900 to 3,000, and most preferably 1,000 to 2,000. This Mw can be measured by GPC which uses polystyrene as a standard.

The content ratio (mass ratio) of the olefin-acid copolymer and the carboxylic acid polymer in the polyethylene resin is 1,000: 1 to 10: 1, preferably 200: 1 to 20: 1, and more preferably 100: 1 to 25: 1. If the content ratio of the carboxylic acid polymer is too low, the effect of combining the olefin-acid copolymer and the carboxylic acid polymer is not sufficiently exhibited. On the contrary, if the content ratio of the carboxylic acid polymer is excessive, the olefin-acid copolymer and the carboxylic acid polymer in the black composition. There is a fear that a uniform black layer is not formed by phase separation.

≪Oxazoline group-containing polymer≫

In the polyethylene resin used in the present invention, since the oxazoline group of the oxazoline group-containing polymer crosslinks with the carboxyl group possessed by the olefin-acid copolymer and the carboxylic acid polymer, the resins crosslink to form a dense network structure. This improves the toughness of the black layer.

As an oxazoline group containing polymer used by this invention, "Epocross (trademark)" by the Nippon Shokubai company whose main chain is styrene / acryl is suitable. This is because the formation of a very hard black layer and the brittleness of the black layer are improved. In particular, the "epocross (registered trademark) K" series of the emulsion type is preferable, and as a grade, K-2010E (Tg: -50 degreeC), K-2020E (Tg: 0 degreeC), and K-2030E (Tg: 50) are preferable. ℃). In order to obtain a hard film, epochross K-2030E is the most preferable.

It is preferable that an oxazoline group containing polymer contains 2 mass parts or more (more preferably, 4 mass parts or more) with respect to a total of 100 mass parts (solid content) of an olefin acid copolymer and a carboxylic acid polymer, 8 mass parts or less It is preferable to contain (more preferably 6 mass parts or less). When content of an oxazoline group containing polymer is less than 2 mass parts, crosslinking reaction may become inadequate, the compactness of a black layer may not be obtained, corrosion resistance may worsen, or surface treated carbon black may not be fixed in a black layer. In addition, the hardness of the black layer cannot be sufficiently obtained, and the scratch resistance may be inferior. On the other hand, when the amount of the oxazoline group-containing polymer exceeds 8 parts by mass, the functional group (carboxyl group) of the black layer decreases due to excessive crosslinking reaction, so that the surface treated carbon black cannot be fixed in the black layer, or the black layer The adhesiveness of a metal plate may fall.

<Polyurethane resin>

In addition to the above-mentioned polyethylene resins, polyurethane resins that can be suitably used as binder resins include carboxyl group-containing polyurethane resins, tolylene diisocyanate, diphenylmethane diisocyanate and dicyclohexyl methane diamond. Urethane prepolymer composed of at least one polyisocyanate component selected from the group consisting of isocyanates and a polyol component containing a polyol having 1,4-cyclohexanedimethanol, a polyether polyol and a carboxyl group The thing obtained by chain extension reaction with a chain extender is mentioned. According to such a structure, even if a crosslinking agent is not added to formation of a black layer, the black metal plate excellent in corrosion resistance, abrasion resistance, etc. can be obtained. In addition, such a polyurethane resin can be manufactured by a known method (for example, Unexamined-Japanese-Patent No. 2005-200757).

≪Polyisocyanate component≫

The polyisocyanate component used in the polyurethane resin is preferably selected from the group consisting of tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI) and dicyclohexylmethane diisocyanate (hydrogen Addition MDI). &Lt; / RTI &gt; By using such a polyisocyanate component, the black metal plate excellent in corrosion resistance can be obtained. In addition to the above essential polyisocyanate component, other polyisocyanate can be used within a range that does not lower the corrosion resistance, but the content ratio of the essential polyisocyanate component is 70% by mass of the total polyisocyanate component. It is preferable to make it ideal. If the content rate of the essential polyisocyanate component is less than 70 mass%, there exists a tendency for corrosion resistance to fall. As polyisocyanate other than the said essential polyisocyanate component, For example, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecane methylene diisocyanate, isophorone diisocyanate Nate, xylene diisocyanate, phenylene diisocyanate, etc. are mentioned. The polyisocyanate component may be used alone or in combination of two or more thereof.

`` Polyol component ''

It is preferable that the polyol component used for a polyurethane resin essentially contains all three types of polyols, such as a 1, 4- cyclohexane dimethanol, a polyether polyol, and the polyol which has a carboxyl group, and all three types are contained. It is more preferable to set it as a diol. As a result, a black metal plate excellent in corrosion resistance and sliding property can be obtained. In particular, by using 1,4-cyclohexanedimethanol as the polyol component, the rust preventing effect of the polyurethane resin can be enhanced.

The polyether polyol is not particularly limited as long as it has at least two or more hydroxyl groups in the molecular chain and the main skeleton is composed of alkylene oxide units. For example, polyoxyethylene glycol (simply referred to as "polyethylene glycol"). Polyoxypropylene glycol (sometimes referred to simply as "polypropylene glycol"), polyoxytetramethylene glycol (simply referred to as "polytetramethylene glycol" or "polytetramethylene ether glycol"). Etc.), and what is marketed can be used. Among the polyether polyols, polyoxypropylene glycol or polytetramethylene ether glycol is preferable.

As the polyether polyol, for example, a commercially available product having an average molecular weight of about 400 to about 4000 is preferable. If the average molecular weight is less than about 400, the black layer is hard, and if it exceeds 4000, it becomes excessively soft. In addition, an average molecular weight can be calculated | required by measuring OH value (hydroxyl value).

In this invention, it is also preferable to make mass ratio of the said 1, 4- cyclohexane dimethanol and polyether polyol into 1, 4- cyclohexane dimethanol: polyether polyol = 1: 1-1:19. It is the sun. By using 1, 4- cyclohexane dimethanol which has an rust prevention effect at a fixed ratio, the rust prevention effect of the polyurethane resin obtained can be heightened further.

The polyol having a carboxyl group used in the present invention is not particularly limited as long as it has at least one or more carboxyl groups and at least two or more hydroxyl groups, and examples thereof include, for example, dimethylolpropionic acid, dimethylolbutane acid, dihydroxypropionic acid, and dihydride. Roxysuccinic acid etc. are mentioned.

In addition to the above essential polyol component, other polyols can be used within a range not lowering the corrosion resistance, but the content ratio of the essential polyol component is preferably 70% by mass or more of the total polyol component. If the content rate of essential polyol component is less than 70 mass%, there exists a tendency for corrosion resistance to fall. As polyols other than the essential polyol component mentioned above, if it has a plurality of hydroxyl groups, it will not specifically limit, For example, low molecular weight polyol, high molecular weight polyol, etc. are mentioned. Low molecular weight polyols are polyols having an average molecular weight of about 500 or less, and high molecular weight polyols are polyols having an average molecular weight of more than about 500.

`` Urethane Prepolymer ''

The urethane prepolymer (specifically, a relatively low molecular weight carboxyl group-containing isocyanate group-terminated urethane prepolymer) uses an above-described polyisocyanate component and a polyol component, and the isocyanate group is excessive at an NCO / OH ratio. It can be mixed so that it may be obtained. Although the temperature which synthesize | combines a urethane prepolymer is not specifically limited, It is preferable that it is 50-200 degreeC.

In preparation of a urethane prepolymer, it is also a preferable aspect to use a solvent from a viewpoint of adjusting a viscosity and improving the emulsion dispersibility of the said prepolymer. As a solvent, it is preferable to use a relatively high hydrophilic solvent as a solvent inactive with respect to an isocyanate group, For example, N-methylpyrrolidone, acetone, ethyl acetate, methyl ethyl ketone, N, N-dimethyl Formamide and the like can be used, and N-methylpyrrolidone is preferably used.

After completion of the reaction between the polyisocyanate component and the polyol component, the obtained urethane prepolymer is preferably neutralized with a base and emulsified and dispersed in water. Although it does not specifically limit as a neutralizing agent, Ammonia; Tertiary amines such as triethylamine and triethanolamine; Hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide can be used, and triethylamine is preferably used.

≪Carboxyl group-containing polyurethane resin≫

The carboxyl group-containing polyurethane resin used by this invention can be obtained by performing a chain extension reaction using a chain extender in water, after emulsion-dispersing the said urethane prepolymer. In addition, a chain extension reaction can be suitably performed before emulsion dispersion, simultaneous with emulsion dispersion, or after emulsion dispersion according to the reactivity of the chain extension agent to be used.

Although it does not specifically limit as a chain extender used by this invention, For example, Aliphatic polyamine, such as ethylene diamine, propylene diamine, hexamethylene diamine; Aromatic polyamines such as tolylene diamine, xylylene diamine, diaminodiphenylmethane; Alicyclic polyamines such as diaminocyclohexyl methane, piperazine and isophorone diamine; Hydrazines, such as hydrazine, succinic-acid dihydrazide, adipic acid dihydrazide, and phthalic-acid dihydrazide, etc. are mentioned. Among these, ethylene diamine and / or hydrazine are preferable.

It is preferable that the acid value of the carboxyl group-containing polyurethane resin used by this invention is 10 mgKOH / g or more and 60 mgKOH / g or less. If the acid value is less than 10 mgKOH / g, the stability of the aqueous dispersion liquid of the polyurethane resin may decrease. When an acid value exceeds 60 mgKOH / g, there exists a tendency for the corrosion resistance of the black metal plate obtained to fall. In addition, the measurement of an acid value is based on JIS-K0070.

(Black composition)

The black composition used by this invention can obtain the said surface-treated carbon black and binder resin by mixing in the said predetermined ratio. For example, the aqueous solution (surface containing carbon black and water-soluble resin) of surface treated carbon black, and binder resin can be mixed and prepared. The aqueous solution of the surface-treated carbon black can be prepared by a known method (for example, Japanese Patent Application Laid-Open No. 1995-188597 or Japanese Patent Application Laid-Open No. 1994-234946), and is commercially available as a ink (for example, Kure Co., Ltd.). Takeze `` super mute color BA-8 '').

Here, when using the said aqueous solution, it is preferable to use the aqueous solution whose volume average particle diameter (secondary aggregated particle diameter) of surface-treated carbon black in aqueous solution is 1000 nm or less. By preparing a black composition using such an aqueous solution, even a thin film can conceal the gloss and hue of the surface of a metal plate, and can form the black layer which can express deep blackness. In order to obtain a deeper black appearance, it is preferable to use an aqueous solution having a volume average particle diameter of 700 nm or less, and more preferably to use an aqueous solution of 500 nm or less. On the other hand, the conventionally well-known aqueous solution of untreated carbon black may have a volume average particle diameter of 4400 nm.

In the black metal plate of the present invention, the black layer is formed on one side or both sides of the metal plate with a dry mass of 0.28 g / m ² or more and 1.5 g / m ² or less using the black composition. In particular, when using the black metal plate of this invention as a back cover of a thin television, a black layer can also be formed only in the single side | surface (surface arrange | positioned outside) of a metal plate. When the adhesion amount of a black layer is less than 0.28 g / m <^2> , the blackness (L * value) of a black metal plate may be more than 24, and dark tea color may be seen. When the adhesion amount of a black layer exceeds 1.5 g / m <^2> , although the blackness (L * value) of a black metal plate will be 24 or less, the electric conductivity requested | required in the field of home appliances, such as a thin type television, may not be achieved. Moreover, while the improvement effect of blackness is lost and stabilized, there also exists a problem that a coating and baking time are long, and manufacturing cost becomes high. In consideration of the conductivity and manufacturing cost of the black metal plate, the adhesion amount of the black layer is preferably 0.35 g / m ² or more (more preferably 0.5 g / m ² or more), and 1.0 g / m ² or less (more preferably 0.75 g / m ² or less).

The method and conditions for forming a black layer using the said black composition are not specifically limited, What is necessary is just to apply a black composition to the single side | surface or both surfaces of a metal plate surface by a well-known coating method, and to heat-dry. As a coating method of a black composition, the bar coater method, the curtain flow coater method, the roll coater method, the spray method, the spray wringer method, etc. are mentioned, for example, Among these, the bar coater method and a roll from a viewpoint of cost etc. The coater method and the spray ringer method are preferable. Moreover, as heat-drying conditions, it is about 50-160 degreeC as heat drying temperature, Preferably about 70-140 degreeC can be illustrated. On the other hand, too high heat drying temperature is not preferable because the black layer is deteriorated.

<Colloidal silica>

It is preferable that the black composition used by this invention contains colloidal silica further. By such a structure, surface-treated carbon black can be fixed to a black layer favorably and the corrosion resistance and hardness of a black metal plate can be improved. Although the detail of this mechanism is unknown, it is guessed that silica is melt | dissolved and eluted in a corrosive environment, and it originates in the buffer effect of pH, and the formation of a floating body film. Moreover, the effect is recognized also in the prevention of the cissing at the time of application | coating and drying of a black composition. The colloidal silica to be used is not particularly limited, but is preferably a colloidal silica having a surface area average particle size of 4 to 20 nm from the viewpoint of dispersibility and corrosion resistance improvement effect in the black composition, and specifically, the surface area Colloidal silica (Snotex XS) with an average particle size of 4-6 nm, colloidal silica (Snotex S) with an average particle size of 8-11 nm, colloidal silica (Snotex 40) with an average particle size of 10-20 nm (all Nissan Chemical Company), and the like.

5 mass parts or more (more preferably, 7 mass parts or more) are preferable in 100 mass parts of black compositions, and, as for content of colloidal silica, 20 mass parts or less (more preferably 15 mass parts or less) are preferable. When content of colloidal silica is less than 5 mass parts, surface treatment carbon black may not be fixed to a black layer favorably. Moreover, the improvement effect of corrosion resistance and a film hardness is not recognized. When content of colloidal silica exceeds 20 mass parts, corrosion resistance may fall rather, and also stability of a black composition may worsen and it may thicken with elapsed time. In addition, the surface-treated carbon black may not be fixed well in a black layer.

<Silane Coupling Agent>

In this invention, a silane coupling agent can also be added to a black composition. By adding a silane coupling agent, the corrosion resistance of a black metal plate can be improved. Moreover, the adhesiveness of the black layer obtained, a metal plate, or the clear layer mentioned later can be improved. As a silane coupling agent, the silane coupling agent which has a glycidoxy group at the terminal is preferable, For example, (gamma)-glycidoxy propyl trimethoxysilane, (gamma)-glycidoxy propylmethyl diethoxysilane, and vinyl tris ((beta) -methoxyethoxy) silane etc. are mentioned.

The amount of the silane coupling agent added is preferably 1 part by mass or more (more preferably 2 parts by mass or more) with respect to 100 parts by mass of the black composition, and 17 parts by mass or less (more preferably 15 parts by mass or less). It is preferable to set it as. When addition amount is less than 1 mass part, the effect by adding a silane coupling agent may not fully be acquired. Moreover, when content of a silane coupling agent exceeds 17 mass parts, the quantity of the silane coupling agent which does not contribute to reaction increases, but there exists a tendency for corrosion resistance to fall.

<Wax>

Wax may be further added to the black composition used in the present invention. In home appliances, such as thin televisions, a complicated press working etc. are often given to a black metal plate. In that case, as a required performance on the back surface of the black metal plate, workability is required in addition to the above-described conductivity and corrosion resistance. By adding an aqueous wax to the black composition, lubricity can be imparted to the black layer, thereby improving workability. Examples of the aqueous wax include polyethylene waxes such as "Chemical W700", "Chemical W950" and "Chemical W900" manufactured by Mitsui Chemicals. It is preferable that the addition amount of a wax shall be 1-10 mass parts (more preferably 3-7 mass parts) with respect to 100 mass parts of black compositions. When the amount of wax added is less than 1 part by mass, the effect of addition is not seen. Even if wax is added beyond 10 parts by mass, the effect of lowering the kinetic friction coefficient is saturated.

(Clear floor)

The black metal plate of this invention may have a clear layer on a black layer. By such a structure, the black metal plate of this invention can improve scratch resistance, workability, and corrosion resistance, and also blackness (L * value) tends to improve (FIGS. 4 and 6). In addition, since the glossiness increases with an increase in the adhesion amount of the clear layer, a black metal plate having a black appearance of jet black can be obtained (FIG. 7).

The adhesion amount of the clear layer is preferably 1 g / m ² or more (more preferably 1.5 g / m ² or more, more preferably ² g / m ² or more), and 4 g / m ² or less (more preferably, in dry mass). 3.5 g / m ² or less, more preferably 3 g / m ² or less). If the adhesion amount of the clear layer is less than 1 g / m ² , the effect of improving scratch resistance, workability and corrosion resistance cannot be obtained. Moreover, when the adhesion amount exceeds 4 g / m <^2> , the improvement effect of corrosion resistance and abrasion resistance is recognized, but workability falls and it becomes easy to produce black layer peeling at the time of press molding, for example. On the other hand, when the adhesion amount of a clear layer becomes 3 g / m <^2> or more, blackness (L * value) and glossiness G60 will change significantly (FIG. 7).

In the clear resin composition which comprises a clear layer, a weight average molecular weight is 10,000-25,000 (more preferably 15,000-25,000), Tg is 35-75 degreeC, and a hydroxyl value is 5 mgKOH / g or more (more preferably 6 mgKOH / It is preferable that polymeric polyester resin which is g or more) is contained. By forming a clear layer using such a polymeric polyester resin, a black metal plate excellent in workability and scratch resistance can be obtained.

If the weight average molecular weight of the polymeric polyester resin is less than 10,000, the flexibility and toughness of the clear layer will be insufficient, and thus the corrosion resistance, workability and scratch resistance of the black metal plate will be reduced. When the weight average molecular weight exceeds 25,000, the flexibility and toughness are excellent, but the densification of the clear layer may be insufficient due to the reduction of the functional groups reacting with the crosslinking agent, and the corrosion resistance may be deteriorated.

When Tg of polymeric polyester resin is less than 35 degreeC, sufficient clear layer hardness may not be obtained and scratch resistance may fall or a clear layer may peel in press work. Moreover, when Tg exceeds 75 degreeC, a clear layer may become hard too much, a crack may arise in a clear layer at the time of clear layer formation, and corrosion resistance may fall. Moreover, since a clear layer becomes brittle, clear layer peeling may generate | occur | produce by the impact at the time of processing.

As the polymer polyester resin, "ARAKYD 7021", "KA-2112", "KA-2049E" (above, Arakawa Chemical Industries, Ltd.), "Byron 28SS", "Byron 29XS" (above, Toyo Spinning Co., Ltd.), "Super Beckolite M-6805-40", "Super Beckolite M-6801-30", "Becolite M-620140-IM" (above, made by DIC Corporation), etc. are mentioned. have. On the other hand, a crosslinking agent can also be added to a clear resin composition in order to further improve the corrosion resistance, workability, and scratch resistance of the black metal plate obtained using a polymeric polyester resin. As a crosslinking agent, "Cymel 303", "Cymel 370", "Cymel 325" (above, made by Nippon Sci-Tech Industries, Inc.), "Sumimal M-40WT" (made by Sumitomo Chemical Co., Ltd.), "Super Bectamine L" Methylated melamine resins such as "105-60" (manufactured by DIC Corporation); Butylated melamine resins such as "Super Baccamine L-145-60", "Super Baccamine L-117-60", "Super Baccamine L-125-60" (above, manufactured by DIC Corporation); Butylated benzoguanamine resins, such as "super becamine TD-126" and "super becaamine 15-594" (above, DIC Corporation), are mentioned. These crosslinking agents may be used alone or in combination of two or more thereof. On the other hand, as an acid hardening catalyst for a crosslinking agent, the product made by Kusumoto Chemicals Co., Ltd. (made by KING INDUSTRIES, INC) "NACURE 5225", "NACURE 3525", "Bacamine P-198" by DIC Corporation, etc. are mentioned.

As a method of increasing the crosslinking density in order to further improve the corrosion resistance of the black metal plate, a weight average molecular weight of 10,000 to 25,000 (more preferably 15,000 to 25,000), a polymer polyester resin of Tg 35 to 75 ° C, and a weight average molecular weight of 1,500 to You may mix 2,500 and Tg 10-45 degreeC low molecular polyester resins with the mixture ratio of polymeric polyester resin: low molecular polyester resin (mass ratio) = 8: 2-6: 4, and can comprise a clear resin composition. . The polymer polyester resin has a hydroxyl value of 10 mgKOH / g or less in many cases, and the crosslinking reaction (functional group) when the crosslinking agent is added is insufficient, so that the crosslinking reaction is insufficient and densification of the clear layer cannot be achieved. Thus, by adding a low molecular polyester resin having a large hydroxyl value to promote the crosslinking reaction with the crosslinking agent, a dense clear layer can be formed to significantly improve corrosion resistance, chemical resistance and the like. In other words, by blending the high molecular polyester resin and the low molecular polyester resin at the above mixing ratio, the high molecular polyester resin exhibits processability and scratch resistance, and the corrosion resistance and chemical resistance of the low molecular polyester resin and the crosslinking agent It expresses by densification of the clear layer by a crosslinking reaction. On the other hand, it is preferable that the average hydroxyl group of mixed polyester resin at this time will be 25 mgKOH / g or more. Examples of the low molecular polyester resin include "becolite 46-118", "becolite M-6405-50", "becolite M-6402-50", and the like.

The molecular weight (weight average molecular weight) of the said polyester resin uses tetrahydrofuran as an eluent, connects two columns ("KF-804L" made by Shodex) in series, and uses column temperature of 40 degreeC, and flow rate of 1.0 ml / min. Under the conditions, it measured using gel permeation chromatography (GPC) "Intelligent HPLC by JASCO company", and calculated | required by polystyrene conversion. The hydroxyl value can be obtained according to JIS K 0070. In addition, when using commercially available polyester resin, you may select that whose nominal value is the said range.

It is preferable that the polyester urethane resin whose weight average molecular weights 30,000-40,000, Tg-3-23 degreeC, and a hydroxyl group of 10 mgKOH / g or less are contained in the clear resin composition which comprises a clear layer. Since such polyesterurethane resin has aromatic polyester as a basic skeleton, it is excellent in hydrolysis resistance (water resistance). Moreover, since it has a urethane bond, a hydroxyl group and an acid value become high, as a result, adhesiveness with a black layer improves, reactivity with a crosslinking agent (hardening | curing agent) becomes high, and a strong film can be formed.

When the weight average molecular weight of the polyester urethane resin is less than 30,000, the flexibility, toughness and water resistance of the clear layer may not be obtained. Moreover, when the weight average molecular weight exceeds 40,000, the fluidity | liquidity of resin may worsen and a uniform and smooth film may not be obtained.

If Tg of a polyester urethane resin is less than -3 degreeC, the hardness of a clear film may fall, and workability and scratch resistance may deteriorate. Moreover, when Tg exceeds 23 degreeC, since the hardness of a clear film rises and a softness falls, workability may deteriorate. Similarly, when the hydroxyl value exceeds 10 mgKOH / g, the functional group of the resin may increase, and the flexibility of the clear film may decrease in connection with the increase of the crosslinking point, resulting in deterioration of workability.

As a polyester urethane resin, "Viron UR-8300: weight average molecular weight 30,000, Tg 23 degreeC, hydroxyl group 3-4 mgKOH / g", "Viron UR-2300: weight average molecular weight 32,000, Tg 18 degreeC, hydroxyl group 2-4 mgKOH / g "," Viron UR-3210: weight average molecular weight 40,000, Tg -3 degreeC, hydroxyl group 2-3 mgKOH / g "," Viron UR-3500: weight average molecular weight 40,000, Tg 10 degreeC, Hydroxyl group 10 mgKOH / g "(above, Toyo Spin Co., Ltd.) etc. are mentioned preferably.

Moreover, as a clear resin composition which comprises a clear layer, the polyester urethane resin of the weight average molecular weights 30,000-40,000, Tg -3-23 degreeC, the low molecular weight polyester resin of the weight average molecular weights 1,500-2,500 and Tg 10-45 degreeC It is also preferable to contain a mixed resin having an average hydroxyl value of 25 mgKOH / g or more, which is blended at a mixing ratio of polyester urethane resin: low molecular weight polyester resin (mass ratio) = 2: 8 to 4: 6. If it is such a mixed resin, polyester which is expensive compared with normal polyester resin, fully exhibiting the effect (excellent water resistance, high adhesiveness with a black layer, and strong film which can form, etc.) resulting from a polyester urethane resin The amount of urethane resin used can be reduced, which is advantageous in terms of cost. When there is less polyester urethane resin than the said mixing ratio, water resistance will remarkably deteriorate, water will penetrate into the interface of a black layer and a clear film layer by immersing in boiling water for about 1 hour, and the adhesiveness of an interface will fall, After immersion and drying, peeling may occur at an interface portion and there is a concern that spot-like white unevenness may be observed. When there is more polyester urethane resin than the said mixing ratio, the performance improvement effect (water resistance etc.) suitable for cost will become difficult to be acquired.

<Polyethylene wax>

In this invention, it is preferable that 2-10 mass parts of polyethylene wax are contained in 100 mass parts of clear resin compositions (solid content). By such a structure, a polyethylene wax functions as a lubricant, and can provide a scratch resistance and workability to the black metal plate obtained. If content of a polyethylene wax is less than 2 mass parts, the effect of a wax addition will not be acquired. Even if content of polyethylene wax exceeds 10 mass parts, the friction coefficient reduction effect by wax addition does not improve, but corrosion resistance may fall rather. More preferably, it is 4-6 mass parts. Examples of the polyethylene wax include waxes of solvent dispersion, and specifically, are dispersed in HIGH FLAT X-20 P-2 made by Gifu Shellac Co., Ltd. and toluene, which are dispersed in xylene. HIGH FLAT T-20 P-2.

<Antirust agent>

In this invention, it is preferable that 5 mass parts or more (more preferably 7 mass parts or more) are contained in 100 mass parts of clear resin compositions (solid content), and 20 mass parts or less (more preferably 15 mass parts or less) It is preferably included. When the addition amount of a rust inhibitor is less than 5 mass parts, the rust prevention effects, such as corrosion resistance, are not acquired. Moreover, when the addition amount of a rust preventive agent exceeds 20 mass parts, agglomeration and segregation generate | occur | produce in a clear resin composition, or a poor appearance may arise by the fall of glossiness (loss of gloss generation). Moreover, stability may fall, for example, a precipitate may generate | occur | produce in a solvent type clear resin composition. On the other hand, the glossiness of a black metal plate can also be controlled according to the kind and addition concentration of a rust preventive agent, and a mat appearance can also be obtained, maintaining blackness by increasing an addition concentration.

Specifically as a rust inhibitor, 1 or more types chosen from the group which consists of a calcium ion exchange silica, a solvent colloidal silica, and a tripolyphosphoric acid aluminum dihydrogen phosphate are mentioned. Examples of calcium ion exchange silica include "Sylomask 52", "Silomask 55", "Sylysia 530" and "Sysia 710" manufactured by Fuji Silysia Chemical Ltd. Can be mentioned. Examples of the solvent-based colloidal silica include "XBAST" and "MIBK-ST" manufactured by Nissan Chemical Company. Examples of tripolyphosphoric aluminum dihydrogen phosphate include "K-WHITE G105", "K-WHITE G-110", "K-WHITE # 105", "K-WHITE G730", and the like.

The method and conditions for forming a clear layer using the said clear resin composition are not specifically limited, What is necessary is just to apply a clear resin composition to the surface of a black layer and / or a metal plate, and to heat-dry by a well-known method. As a coating method of a clear resin composition, it may be the same as the method used when forming a black layer. Moreover, as heat drying conditions, about 200-230 degreeC (heat drying time: about 1 to 2 minutes) can be illustrated as heat drying temperature.

When the black metal plate of the present invention has a black layer on only one side of the metal plate, it may have a clear layer on a metal plate on the back side (that is, the side without the black layer). In addition, in this specification, the clear layer provided in the said back surface is called especially a "back surface clear layer", and distinguishes it from the clear layer provided on the black layer mentioned above. By providing a back surface clear layer, further improvement of corrosion resistance etc. can be aimed at.

As for the adhesion amount of a back surface clear layer, 0.2 g / m <^2> or more (more preferably 0.5 g / m <^2> or more) is preferable by dry mass, 2.5 g / m <^2> or less (more preferably 2.0 g / m <^2> or less) Is preferred. If the adhesion amount of the back surface clear layer is less than 0.2 g / m ² , uniform coating on the metal plate becomes difficult, and the effect of improving the corrosion resistance becomes difficult to be obtained. On the other hand, when the adhesion amount of a back surface clear layer exceeds 2.5 g / m < ² >, electroconductivity will fall, or the peeling amount of a resin film will increase at the time of press work, and adhesion accumulation of a peeling film to a metal mold will generate | occur | produce, and it will interfere with press molding. It may cause problems such as causing.

The back side clear layer can be formed by applying an emulsion composition comprising, as a main component, an ethylene-unsaturated carboxylic acid copolymer (including neutralized state) as disclosed in Japanese Patent Application Laid-Open No. 2005-246953. This emulsion composition has a amine having a boiling point of 100 ° C. or lower and an ethylene-unsaturated carboxylic acid copolymer corresponding to 0.2 to 0.8 mole (20 to 80 mole%) with respect to 1 mole of the carboxyl group of the ethylene-unsaturated carboxylic acid copolymer. 100 mass solids of the resin composition containing the crosslinking agent which contains the compound of monovalent metal corresponding to 0.02-0.4 mol (2-40 mol%) with respect to 1 mol of groups, and has 2 or more functional groups which can react with a carboxyl group. It contains 0.5-20 mass% with respect to%, and does not contain amine and ammonia more than boiling point 100 degreeC substantially. In addition, such emulsion compositions include silica particles (colloidal silica, etc.), waxes, diluent solvents, anti-skinning agents, leveling agents, antifoaming agents, penetrants, emulsifiers, film forming aids, color pigments, thickeners, and silane couplers. A ring agent, other resin (for example, carboxylic acid polymer, etc.) can be added suitably.

(Black metal plate)

In this invention, since the surface treated carbon black was used as a black pigment, the black metal plate whose blackness (L * value) is 24 or less can be obtained easily. In the aspect which does not have a clear layer, in the black metal plate of this invention, it is preferable that blackness (L * value) is 23 or less, and it is more preferable that it is 22 or less.

Example

Hereinafter, the present invention will be described in detail with reference to Examples. However, the following Examples do not limit the present invention, and any modifications to the scope not departing from the gist of the preceding and later stages are all included in the technical scope of the present invention.

First, the evaluation method and determination criteria used in the experimental example are described below.

(Single particle size of carbon black)

The aqueous solution of carbon black was suction-filtered with the 0.2 micrometer filter, and the filter residue was observed with the step emission scanning electron microscope FE-SEM ("SU-70" by Hitachi, Ltd.).

(Volume Average Particle Size of Carbon Black in Aqueous Solution)

The aqueous solution of carbon black was measured by laser diffraction / scattering formula using microtrack FRA9220 (made by Leeds & Northrup).

(Volume Average Particle Size of Carbon Black in Black Composition)

It measured similarly to the measuring method of the volume average particle diameter of carbon black in the said aqueous solution.

(Black degree)

Using a spectrophotometer ("Spectro Color Meter SQ2000" manufactured by Nippon Denshoku Industries Co., Ltd.), the L value, a value, and b value of the black metal plate and the black metal plate with a clear layer were measured, and the L * value was calculated according to the following equation (1). Converted to. In this invention, the thing whose L * value is 24 or less (L value: 20 or less) was made into the pass.

Moreover, the black depth (black-black) of the black metal plate and the black metal plate with a clear layer was determined by visual determination, and the following reference | standard evaluated.

◎: deep black

○: black

△: tea black

×: tea color

(Gloss level)

The glossiness (G value) of the black metal plate and the black metal plate with a clear layer was measured and calculated | required by 60 degree angle G60 using "Gloss Meter VG2000" by Nippon Denshoku Industries Co., Ltd.

(Black layer peeling test)

According to JIS K 5600-5-6 (1999), after cutting with a cutter knife shape (1 mm x 1 mm, 100 mas) on the surface of a black metal plate and extruded 6 mm with an Eriksen tester (Ericsen value: 6 mm), An adhesive tape ("CT405AP-24" made by Nichido Co., Ltd.) was affixed, a tape peeling test was performed to peel the tape thereafter, and a peeling state of carbon black was observed and evaluated according to the following criteria.

◎: 100% residual rate of black layer

○: less than 100% of the residual ratio of the black layer 90% or more

(Triangle | delta): Less than 90% of residual ratio of a black layer 80% or more

X: less than 80% of the residual ratio of the black layer

(Carbon black dissolution test)

After immersing a black metal plate or a black metal plate with a clear layer in boiling water for 1 hour, the appearance change (water resistance) by elution of carbon black from a black metal plate or a black metal plate with a clear layer was visually observed, and the following reference | standard evaluated it. .

◎: no change in appearance

○: very little change

(Triangle | delta): There exists a fall of blackness (glossy fall)

×: appearance unevenness due to color omission

(SST time)

About the black metal plate or the black metal plate with a clear layer, the salt spray test was done according to JIS Z 2371, and time (corrosion resistance) until 5% of white rust generate | occur | produced was measured. In the present invention, in the case of the black metal plate, the time was 48 hours, and in the case of the black metal plate with a clear layer, the time was 120 hours.

(SST cycle test)

The black metal plate with a clear layer was subjected to a salt spray test based on JIS Z 2371 for 1 cycle of salt spray (spraying time 8 hours) and 16 hours of rest, and the number of cycles until 5% of white rust was generated. (Corrosion resistance) was counted. In this invention, 4 or more cycles were made into the pass.

◎: 6 cycles or more

○: 4 cycles or more, less than 6 cycles

(Triangle | delta): More than 2 cycles and less than 4 cycles

×: less than 2 cycles

(Backside conductivity)

By the terminal of a tester, the resistance value at the time of sliding the back surface (black metal plate of the side in which the clear layer is not formed) of the black metal plate with a clear layer lightly was measured, and the black with a clear layer was measured by the following reference | standard. The electroconductivity of the back surface of the metal plate was evaluated.

◎: less than 100Ω

○: less than 100Ω ~ 200Ω

△: 200Ω or more ~ less than 500Ω

×: 500Ω or more

(Pencil hardness)

With respect to the black metal plate or the black metal plate with a clear layer, pencil hardness (scratch resistance of surface) in which a scratch does not generate | occur | produce on the black layer or clear layer surface with the pencil scraping tester was calculated | required according to JISK-5400 (1990).

(T bending workability)

A black metal plate with a clear layer cut to a size of 50 × 50 mm is gently bent in a vice with the surface (clear layer forming surface) outward at room temperature (20 ° C.), bent to the limit with the same metal plate as the bent portion, The presence or absence of the crack in the bent part after processing was observed with the naked eye or 10 times loupe. In the evaluation method, the number of sheets of the black metal plate with a clear layer to be sandwiched is 0T and 0T, one sheet is 1T, and the crack limit (for example, when a crack is generated at 1T is 2T) below one rank of the number of cracks on the surface. Crack limit).

(0 ℃ T bending workability)

The black metal plate with the clear layer cut to a size of 50 x 50 mm was cooled to 0 占 폚 and bent at 0 占 폚 with the surface (clear layer forming surface) outward.

(Whitening resistance)

Using an 80-ton crank press apparatus ("NCL-80TS" by Aida Engineering Co., Ltd.), the single test of the black metal plate or the black metal plate with a clear layer was performed on the following conditions.

Mold: cylindrical

Die size: Blank diameter 110 mm, punch outer diameter: 50.64 mm, die inner diameter: 51.64 mm, punch R: 5 mm, die R: 3 mm, clearance:

Processing speed: 40spm

Blank Holder Pressure: 1kg / cm ²

On the bends and sliding surfaces of the molded article, changes in black appearance (whitening resistance) due to peeling due to elongation or impact of the black layer and the clear layer were visually observed, and a black metal plate or a black metal plate with a clear layer was obtained according to the following criteria. The deep drawing workability of was evaluated.

◎: very good

○: good

△: defective

×: very bad

(Tape resistance)

The single press test of the black metal plate with a clear layer was performed similarly to the said whitening resistance. The peeling state of the film at the time of performing the tape peeling test which affixes the adhesive tape ("9595" by Srion Tech Co., Ltd.) to the sliding part (cylindrical side part) of the obtained molded article, and peels the said tape after that. It observed and evaluated the tape peeling resistance by the following reference | standard.

◎: Very good (no film peeling)

○: good (very little peeling)

△: defective (with peeling)

X: very bad (almost all peeled)

(Kinetic friction coefficient)

SUS ball was fixed on the surface (clear layer forming surface) of the black metal plate with a clear layer on the following conditions using HEIDON surface-surface tester (TYPE; 14DR) by Shinto Scientific Co., Ltd. under the following conditions. Sliding while pressurizing under a load, the kinetic friction coefficient was calculated.

Test load: 500g

Sliding Speed: 100mm / Min

Sliding Distance: 40mm

Number of tests: three at room temperature (evaluated with three averages)

Sliding Jig: SUS Ball 10mmφ

(Painting appearance)

In addition to observing with the naked eye, the contact was carried out lightly with a finger, and the presence or absence of the "dark persimmon" was confirmed and evaluated by the following criteria.

◎: smooth, no rough feeling

○: smooth but very slightly rough

(Triangle | delta): There is no luster, and there is a rough feeling

×: thickly thin

(Weather resistance)

About the black metal plate with a clear layer, the sunshine carbon weather meter test was implemented on condition of the following according to JISK5400.

Environmental condition: 63 ± 3 ℃

Survey time: 150 hours

Continuous shower (rainfall) for 18 minutes / 120 minutes

The appearance of the black metal plate with a clear layer before and after the sunshine carbon weather meter test was visually observed, and the change was evaluated based on the following criteria.

◎: no change in appearance

○: very little change

△: there is change in color tone and gloss

×: Change stain occurs in hue and gloss

Next, preparation of each raw material used by the experiment example, and its physical property evaluation are demonstrated below.

(Single particle size of surface treated carbon black and untreated carbon black)

The single particle size of the surface-treated carbon black aqueous solution ("super impregnated BA-8" made by Kuretake Co., Ltd.) and untreated carbon black ("self-dispersion type carbon black Aqua-Black 162" by Tokai Carbon Co., Ltd.) used by an experiment example is measured. It was about 150 nm and about 100 nm, respectively.

(Volume average particle diameter of surface treated carbon black and untreated carbon black in aqueous solution)

The volume average particle diameters of the surface-treated carbon black aqueous solution (BA-8) and the untreated carbon black (Aqua-Black 162) used in the experiment examples were measured to be about 430 nm and about 4400 nm, respectively.

As described above, the surface treated carbon black and the untreated carbon black have almost the same single particle diameter, but the surface treated carbon black in the aqueous solution has a significantly smaller volume average particle diameter than the untreated carbon black. Difficult to coagulate.

(Volume-average particle diameters of surface treated carbon black and untreated carbon black in black composition)

Polyethylene resin ("Kemipearl S100" made by Mitsui Chemicals Corporation), polyurethane resin (Adeka Boniter (BONTIGHTER) made by ADEKA Corporation) as a binder resin in 45 mass parts (equivalent to carbon black equivalent) of ink (BA-8) 45 parts by mass (in terms of resin solid content) and colloidal silica (HUX541 &quot;), epoxy resin (&quot; KA-1826 YA &quot; manufactured by Arakawa Chemical Co., Ltd.), or acrylic resin (&quot; Lika Bond ES-21 &quot; 10 mass parts of "Snowtex XS" by Nissan Chemical Co., Ltd. was added, and the black composition of 10% of solid content concentration was produced.

When the particle size distribution (secondary particle diameter) of the obtained black composition was measured, when acrylic resin and epoxy resin were used as binder resin, volume average particle diameters were 13.05 micrometers and 14.35 micrometers, respectively, and the secondary particle diameter was remarkably increasing. In contrast, in the case of using a polyethylene resin or a polyurethane resin, the volume average particle diameters were 2.82 μm and 4.46 μm, respectively.

As mentioned above, it turns out that it is preferable to use polyethylene resin or a polyurethane resin as binder resin used by this invention from the point which can interfere with secondary aggregation of surface treated carbon black.

(Preparation of binder resin (polyethylene resin) precursor)

Ethylene-acrylic acid copolymer ("Primachol (trademark) 5990I" by Dow Chemical Co., Ltd., structural unit derived from acrylic acid) as an olefin acid copolymer in the autoclave which has an emulsification installation equipped with a stirrer, a thermometer, and a temperature controller: 20 mass% , Mass mean molecular weight (Mw): 20,000, melt index: 1300, acid value: 150) 200.0 parts by mass, a polymaleic acid aqueous solution ("Nonpol (registered trademark) PMA-50W" made by Nichi Corporation), Mw: about 1100 ( Polystyrene conversion), 50% by mass product) 8.0 parts by mass, 35.5 parts by mass of triethylamine (0.63 equivalents to carboxyl group of ethylene-acrylic acid copolymer), 6.9 parts by mass of 48% NaOH aqueous solution (with respect to carboxyl group of ethylene-acrylic acid copolymer) 0.15 equivalent), 3.5 mass parts of tall oil fatty acid ("Hatol FA3" by Harima Chemicals Co., Ltd.), and 792.6 mass parts of ion-exchanged water were added and sealed, and it stirred at high speed at 150 degreeC and 5 atmospheres for 3 hours, and cooled to 30 degreeC. Glycidoxy group-containing silane coupling agent (Momentive Performance Materials, Inc. (former name: GE Toshiba Silicone Co., Ltd.) "TSL8350", γ-glycidoxypropyltrimethoxysilane) 10.4 parts by mass, carbodiimide Group-containing compound (Carbodilite (registered trademark) SV-02, manufactured by Nisshinbo Chemical Co.), polycarbodiimide, Mw: 2,700, solid content 40 mass%) 31.2 parts by mass, ion exchange water 72.8 mass parts was added, and it stirred for 10 minutes, and prepared the aqueous dispersion (emulsion) of the binder resin (polyethylene-type resin) precursor (solid content concentration about 20 mass%, measured according to JISK6833). Hereinafter, the said emulsion may be called "binder resin (a) precursor."

(Preparation of binder resin (polyurethane resin))

60 mass parts, 1,4- of polytetramethylene ether glycol (Hodogaya Chemical Co., Ltd. make, average molecular weight 1000) as a polyol in the synthesis | combination apparatus provided with the stirrer, the thermometer, and the temperature controller. 14 parts by mass of cyclohexanedimethanol and 20 parts by mass of dimethylol propionic acid were added, and 30.0 parts by mass of N-methylpyrrolidone was further added as a reaction solvent. 104 mass parts of tolylene diisocyanates (henceforth simply "TDI") were thrown as an isocyanate component, it heated up at 80-85 degreeC, and made it react for 5 hours, and obtained the urethane prepolymer. The NCO content of the obtained prepolymer was 8.9%. Furthermore, 16 mass parts of triethylamines are added, neutralization is carried out, 16 mass parts of ethylene diamines, and the mixed aqueous solution of 480 mass parts of water are added, it emulsifies at 50 degreeC for 4 hours, and it chain-reacts and aqueous dispersion of a polyurethane resin (emulsion) ) Was prepared (solid content concentration 29.1%, acid value 41.4). Hereinafter, the said emulsion may be called "binder resin (b)."

Experimental Examples 1-1 to 1-10: Preparation of Black Metal Plate

(Preparation of black composition)

As surface-treated carbon black, it is added to 44.4-133.3 mass parts of ink (Kuratake Co., Ltd. "super concentrated ink, BA-8") with stirring pure water 138.2-107.8 mass parts, Next, 99.8-42.8 mass of binder resin (a) precursors After the addition, 15 parts by mass of colloidal silica ("Snotex (registered trademark) XS" manufactured by Nissan Chemical Co., Ltd., 20% of solid content concentration) was added, and finally, Epocross (registered trademark) K as an oxazoline group containing polymer. 2.6-1.1 mass parts of -2030E (made by Nippon Shokubai Co., Ltd.) is added, and 20-60 mass parts of surface treated carbon black, 30-70 mass parts of binder resins (a), and colloidal silica 10 in 100 mass parts of black compositions 300 mass parts of black compositions (solid content concentration 10 mass%) containing a mass part were prepared, respectively. On the other hand, the oxazoline group containing polymer was added so that 5 mass parts may be contained with respect to a total of 100 mass parts of an ethylene-acrylic acid copolymer and polymaleic acid.

(Production of black metal plate)

The prepared black composition was electroplated galvanized steel sheet (EG; Zn adhesion amount 20g / m ² ), hot dip galvanized steel sheet (GI; Zn adhesion amount 60g / m ² ), titanium plate (Ti), aluminum plate (Al) ), It was applied by a bar coater so as to have a dry mass of 0.5 g / m ² , and dried at 120 ° C. for 60 seconds to prepare a black metal plate.

Experimental example 1-11-1-20: Preparation of the black metal plate with a clear layer

(Preparation of clear resin composition 1)

3.4 mass parts and acid hardening of a crosslinking agent ("Simel 303" made by Nippon Sci-Tech Industries, Ltd.) to 45.3 mass parts of polymer polyester resin ("KA-2112" made by Arakawa Chemical Industries, Ltd., weight average molecular weight 23,000, Tg 70 degreeC) After adding 2.5 mass parts of catalysts ("NACURE 5225" made by Kusumoto Chemical Co., Ltd.), stirring, Next, after adding 5.1 mass parts of polyethylene wax ("X-20P-2" by a climate shellac company), tripolyphosphoric acid dihydrogen phosphate was used as a rust inhibitor. 1.0 mass part of aluminum ("K-WHITE G105" made by Teika Corporation) and 1.0 mass part of calcium ion exchange silica ("silomask 52" made by Fuji Silysia Chemical Co., Ltd.) are added, and dilute thinner ("N made by Nippon Paint Co., Ltd.) Thinner 450 &quot;) and diluted to 144.2 parts by mass. The obtained solvent-based clearing resin composition 1 contains 68 mass% of polymer polyester resin, 17 mass% of crosslinking agents, 5 mass% of tripolyaluminum dihydrogen phosphate, 5 mass% of calcium ion exchange silica, and 5 mass% of polyethylene wax as a rust inhibitor. It consists of 2.6 mass% of acid hardening catalysts outside an edge.

(Production of black metal plate with clear layer)

The solvent-based clear resin composition 1 was bar-coated to the surface of the black layer of the black metal plate obtained in Experimental example 1-1-1-10 so that dry mass might be 2 g / m <^2> , and the black metal plate with a clear layer was produced.

(Evaluation result of black metal plate, black metal plate with clear layer)

Table 1 shows the evaluation results of the black metal plate and the black metal plate with a clear layer.

Surface treatment from the comparison of Experimental Examples 1-1 to 1-8, Experimental Examples 1-9 to 1-10, and Experimental Examples 1-11 to 1-18 and Experimental Examples 1-19 to 1-20 When the content rate of carbon black is 25-60 mass%, it turns out that the black metal plate excellent in blackness (L * value 24 or less) is obtained. Moreover, when content rate of surface treatment carbon black exceeds 60 mass%, it turns out that the adhesiveness of a black layer and a metal layer may be inferior. In the black metal plate with a clear layer of Experimental Examples 1-11 to 1-18, carbon black could be prevented from eluting from a black layer sufficiently.

The relationship between carbon black density | concentration, b value of a black metal plate, and L * value at the time of using EG as a metal plate is shown to FIGS. From the comparison with FIG. 4 and FIG. 6, it turns out that the black metal plate provided with the clear layer tends to improve (L * value becomes small).

Experimental Examples 2-1 to 2-10: Preparation of Black Metal Plate

(Preparation of black composition)

422.6 mass parts of pure waters were added to 259.3 mass parts of ink (BA-8), stirring, and after adding 261.3 mass parts of precursors of a binder resin (a), 50 mass parts of colloidal silica (Snotex XS) was added. Finally, except that 6.9 parts by mass of Epocross (registered trademark) K-2030E was added, in the same manner as in Experimental Example 1-1, 35 parts by mass of surface-treated carbon black and binder resin ( a) 1000 mass parts of black compositions (solid content concentration 10 mass%) containing 55 mass parts and 10 mass parts of colloidal silica were prepared.

(Production of black metal plate)

The prepared black composition was applied to both sides of the galvanized steel sheet (EG; Zn adhesion amount 20 g / m ² ) having a plate thickness of 0.5 mm so as to have a dry mass of 0.25 to 1.7 g / m ² with a manual roll coat apparatus, and the drying temperature was 120. It dried at 60 degreeC for 60 second, and produced the black metal plate.

Experimental Examples 2-11 to 2-15: Preparation of Black Metal Plate

(Preparation of black composition)

Self-dispersible carbon in 100 parts by mass of black composition in the same manner as in Experiment 2-1 except that self-dispersible carbon black (Aqua-Black 162, manufactured by Tokai Carbon Co., Ltd.) was used instead of ink (BA-8). 1000 mass parts of black compositions (solid content concentration 10 mass%) containing 35 mass parts of black, 55 mass parts of binder resin, and 10 mass parts of colloidal silica were prepared.

(Production of black metal plate)

Instead of the black composition prepared in Experimental Example 2-1, using the black composition prepared in Experimental Example 2-11, except that the dry mass of the black composition was applied so as to be 0.30 ~ 1.80g / m ² Experimental Example 2- In the same manner as in 1, a black metal plate was produced.

Experimental Example 2-16-2-30: Preparation of the black metal plate with a clear layer

(Preparation of clear resin composition 2)

3.4 mass parts of crosslinking agents (cymel 303) and 2.0 mass parts of acid hardening catalysts (NACURE 5225) in 38.9 mass parts of high-molecular-polyester-type resin (Arakawa 7012 by Arakawa Chemical Industries; weight average molecular weight 25,000, Tg 50 degreeC) After adding while stirring, and then adding 5.1 parts by mass of polyethylene wax (X-20 P-2), 2.0 parts by mass of tripolyaluminum dihydrogen phosphate (K-WHITE G105) was added as a rust inhibitor, and diluted thinner (N thinner 450 ) Diluted and stirred at 150.7 parts by mass, solvent-based clear resin composition 2 containing 68% by mass of polymer polyester resin, 17% by mass of crosslinking agent, 2.6% by mass of acid curing catalyst, 10% by mass of rust preventive agent, and 5% by mass of polyethylene wax. Prepared.

(Production of black metal plate with clear layer)

The solvent-based clear resin composition 2 was bar-coated to the single side | surface of the black metal plate obtained in Experimental example 2-1-2-15 so that dry mass might be 2 g / m <^2> , and the black metal plate with a clear layer was produced.

(Evaluation result of black metal plate, black metal plate with clear layer)

Table 2 shows the evaluation results of the black metal plate and the black metal plate with a clear layer.

Surface-treated carbon as a black pigment from the comparison of Experimental Examples 2-1 to 2-8, Experimental Examples 2-11 to 2-15, and Experimental Examples 2-16 to 2-23 and Experimental Examples 2-26 to 2-30 By using black, it turns out that the black metal plate excellent in blackness and corrosion resistance is obtained compared with the case where untreated carbon black is used. The untreated carbon black is considered to be due to the secondary aggregation in the black composition and the surface of the black layer to be in a roughly porous state.

Moreover, it turns out that peeling of carbon black from a black layer is also suppressed by using surface treated carbon black as a black pigment. In particular, in the (with clear layer) black metal plate (Experimental Examples 2-1 to 2-8, Experimental Examples 2-16 to 2-23) of the present invention, elution of carbon black from the black layer is not recognized at all.

When the surface treated carbon black was used (Experimental Examples 2-1 to 2-10) and when untreated carbon black was used (Experimental Examples 2-11 to 2-15), the black layer adhesion amount and the L * value of the black metal plate The relationship is shown in FIGS. 1 and 2. From FIG. 1, when surface-treated carbon black is used, a black metal plate having an adhesion amount of the black layer of about 0.3 g / m ² and a blackness (L * value) of 24 or less is obtained. It can be seen that the L * value is almost stable at a deposition amount of about 0.5 g / m ² or more. In contrast, from Fig. 2, when untreated carbon black is used, a black metal plate having a blackness (L * value) of 24 or less cannot be obtained at a deposition amount of 0.3 g / m ² , and the variation in L * value is obtained. It can be seen that the stable blackness is not obtained because is large.

Experimental Examples 3-1 to 3-9: Preparation of Black Metal Plate

(Preparation of black composition)

As an oxazoline group containing polymer which is a binder resin (a) composition, Epocross (trademark) K-2030 E (A), Epocross (trademark) K-2020 E (B), Epocross (trademark) K- 100 parts by mass of the ethylene-acrylic acid copolymer and polymaleic acid in total using any one of 2010 E (C) (all manufactured by Nihon Shokubai Co., styrene / acrylic resin) and an oxazoline group-containing polymer. 35 mass parts of surface-treated carbon black, 55 mass parts of binder resins (a), and colloidal silica in 100 mass parts of black compositions except having added so that 1-10 mass parts may be contained with respect to it. The black composition containing 10 mass parts was prepared.

(Production of black metal plate)

The prepared black composition was applied to both sides of an electrogalvanized steel sheet (EG; Zn adhesion amount 20 g / m ² ) having a sheet thickness of 0.5 mm so as to have a dry mass of 0.5 g / m ² with a manual roll coat apparatus, and to a drying temperature of 120 ° C. It dried for 60 second and produced the black metal plate. Table 3 shows the evaluation results of the obtained black metal plate.

From the comparison of Experimental Examples 3-1 to 3-7 and Experimental Examples 3-8 to 3-9, when using polyethylene resin as binder resin, the content rate of the oxazoline group containing copolymer in the said resin is 2-8 mass%. It can be seen that a black metal plate excellent in corrosion resistance can be obtained by fixing the surface-treated carbon black in the black layer satisfactorily.

Experimental Examples 4-1 to 4-11: Preparation of a black metal plate

(Preparation of black composition)

As colloidal silica, Snowtex XS (A; surface area average particle diameter 4-6 nm), Snowtex 40 (B; surface area average particle diameter 10-20 nm), Snowtex S (C; surface area average particle diameter 8-11 nm) (all Nissan Chemical Manufactured), and the content in 100 parts by mass of the black composition is 35 parts by mass of surface treated carbon black, 50 to 75 parts by mass of binder resin (a), and 0 to 25 parts by mass of colloidal silica. In the same manner as in Experiment 1-1, a black composition was prepared. In addition, the surface area average particle diameter of colloidal silica is a value measured by the Sears method when surface area average particle diameter is about 1-10 nm, the value measured by BET method when it is about 10-100 nm, or a manufacturer's brochure It means nominal value.

(Production of black metal plate)

The prepared black composition was applied to both sides of an electrogalvanized steel sheet (EG; Zn adhesion amount 20 g / m ² ) having a sheet thickness of 0.5 mm so as to have a dry mass of 0.5 g / m ² with a manual roll coat apparatus, and to a drying temperature of 120 ° C. It dried for 60 second and produced the black metal plate. Table 4 shows the evaluation results of the obtained black metal plate.

Black metal plate excellent in corrosion resistance and abrasion resistance by containing 5-20 mass% of colloidal silica in a black composition from the comparison of Experimental example 4-1-4-7 and Experimental example 4-8-4-11. It can be seen that this is obtained. Moreover, it turns out that surface-treated carbon black can be fixed favorably in a black layer.

Experimental Examples 5-1 to 5-7: Preparation of Black Metal Plate

(Preparation of black composition)

Except having used binder resin (b) instead of binder resin (a) precursor, it carried out similarly to Experimental Example 2-1, 35 mass parts of surface-treated carbon black and 55 mass of binder resins (b) in 100 mass parts of black compositions. A black composition containing 10 parts by mass of colloidal silica was prepared. Moreover, 0-17 mass parts of silane coupling agents ("KBM403" by Shin-Etsu Chemical Co., Ltd.) were added with respect to 100 mass parts of black compositions.

The prepared black composition (containing a silane coupling agent) is applied to both sides of an electrogalvanized steel sheet (EG; Zn adhesion amount 20 g / m ² ) having a sheet thickness of 0.5 mm so as to have a dry mass of 0.5 g / m ^{2 using a} manual roll coat apparatus. Then, it dried for 60 second at 120 degreeC of drying temperature, and produced the black metal plate.

Experimental Example 5-8-5-14: Preparation of the black metal plate with a clear layer

(Preparation of clear resin composition 3)

60 parts by mass of polymer polyester resin ("Vylon 29XS" made by Toyo Spinning Co., Ltd .; weight average molecular weight 20,000-25,000, Tg = 72 degreeC, hydroxyl group 6.5mgKOH / g) a crosslinking agent (Sumitomo make by Sumitomo Chemical Co., Ltd.) M-40WT)) 15 mass parts and 10 mass parts of rust inhibitors ("XBA-ST" made by Nissan Chemical Co., Ltd .: solvent-based colloidal silica) are added, stirring, Next, 5 mass of polyethylene wax (X-20P-2) After adding a part, it dilutes and stirs with 10 mass parts of dilution thinners (N thinner 450), and the solvent containing 68 mass% of polymeric polyester resins, 17 mass% of crosslinking agents, 10 mass% of rust inhibitors, and 5 mass% of polyethylene waxes System clear resin composition 3 (solid content concentration 10 mass%) was prepared.

(Production of black metal plate with clear layer)

The solvent-based clear resin composition 3 was bar-coated to the single side | surface of the black metal plate obtained by Experimental Examples 5-1-5-7 so that dry mass might be 2 g / m <^2> , and the black metal plate with a clear layer was produced. Table 5 shows the evaluation results of the obtained black metal plate with a clear layer.

From Table 5, even when binder resin (b) (polyurethane resin) is used instead of binder resin (a) (polyethylene resin), black is excellent in the adhesiveness of a black layer and a metal layer, it is hard to elute carbon black, and black is also excellent in corrosion resistance. It can be seen that a metal plate is obtained.

Moreover, it turns out that corrosion resistance of a black metal plate improves by adding a silane coupling agent to a black composition.

Experimental Examples 6-1 to 6-9: Preparation of Black Metal Plate with Clear Layer

(Preparation of black composition)

A black composition was prepared in the same manner as in Experimental Example 2-1.

(Production of black metal plate)

The prepared black composition was applied to both sides of an electrogalvanized steel sheet (EG; Zn adhesion amount 20 g / m ² ) having a sheet thickness of 0.5 mm so as to have a dry mass of 0.5 g / m ² with a manual roll coat apparatus, and to a drying temperature of 120 ° C. It dried for 60 second and produced the black metal plate.

(Production of black metal plate with clear layer)

On one side of the black metal plates obtained in Experimental Examples 6-1 to 6-9, the solvent-based clear resin composition 2 prepared in Experimental Example 2-16 was coated with a bar coat so as to have a dry mass of 0.5 to 5 g / m ^2. A black metal plate was produced. Table 6 shows the evaluation results of the obtained black metal plate with a clear layer.

From the comparison of Experimental Examples 6-1 to 6-7 and Experimental Examples 6-8 to 6-9, by setting the adhesion amount of the clear layer to 1 to 4 g / m ² , black having excellent corrosion resistance, scratch resistance, and workability It can be seen that a metal plate is obtained.

The influence of the clear layer adhesion amount on the blackness (L * value) and glossiness of the black metal plate is shown in FIG. It can be seen that the blackness and glossiness greatly vary in the amount of adhesion around 3 g / m ² .

Experimental example 7-1-7-33: Preparation of the black metal plate with a clear layer

(Production of black metal plate)

A black metal plate was produced in the same manner as in Experiment 5-1 except that 7 parts by mass of a silane coupling agent ("KBM403" manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 100 parts by mass of the black composition.

(Preparation of clear resin composition 4)

The following polymer polyester resin, polyester urethane resin, or low molecular polyester resin (A-E; manufactured by Arakawa Chemical Co., Ltd., F ~ I, O; manufactured by Toyo Spinning Co., Ltd., J ~ M, P ~ Q; DIC Corporation) The solvent-based clearing resin composition 4 containing 68 mass% of polyester-type resins, 17 mass% of crosslinking agents, 10 mass% of rust preventive agents, and 5 mass% of polyethylene waxes similarly to Experiment Example 5-8 except having used the Prepared.

A: arachid 7012, weight average molecular weight 25,000, Tg 50 ° C, hydroxyl group 7.5

B: KA-2112, weight average molecular weight 23,000, Tg 70 ° C, hydroxyl group 7.0

C: KA-2049E, weight average molecular weight 22,000, Tg 70 ° C, hydroxyl group 7.0

D: KA-2059S, weight average molecular weight 22,000, Tg 70 ° C, hydroxyl group 4.0

E: arachid 7036, weight average molecular weight 26,000, Tg 20 ° C, hydroxyl group 12.5

F: Byron 29XS, weight average molecular weight 20,000-25,000, Tg 72 degreeC, hydroxyl value 6.5

G: Byron 28SS, weight average molecular weight 15,000-20,000, Tg 68 degreeC, hydroxyl value 6.5

H: Byron GK59CS, weight average molecular weight 5,000-8,000, Tg 15 degreeC, a hydroxyl group is 17.0

I: Byron GK13CS, weight average molecular weight 5,000-8,000, Tg 15 degreeC, hydroxyl group 20.5

J: Super becolite M-6801-30, weight average molecular weight 15,000, Tg 72 degreeC, hydroxyl group 10.0

K: becolite 46-118, weight average molecular weight 1,500, Tg 20 ° C, hydroxyl group 120

L: Becolite M-6405-50, weight average molecular weight 2,500, Tg 42 degreeC, hydroxyl group 120

M: becolite M-6402-50, weight average molecular weight 2,500, Tg 10 ° C, hydroxyl group 120

O: Byron UR-3500, weight average molecular weight 40,000, Tg 10 ° C, hydroxyl group 10

P: Super becolite M-6805-40, weight average molecular weight 15,000, Tg 35 degreeC, hydroxyl group 10

Q: Becolite M-6201-40-IM, weight average molecular weight 10,000, Tg 41 degreeC, hydroxyl group 30

(Production of black metal plate with clear layer)

On one side of the black metal plate, the solvent-based clear resin composition 4 was bar coat-coated so as to have a dry mass of 2 g / m ² , thereby producing a black metal plate with a clear layer. Table 7 shows the evaluation results of the obtained black metal plate with a clear layer.

From the comparison of Experimental Examples 7-1 to 7-19 and Experimental Examples 7-25 to 7-33 and Experimental Examples 7-20 to 7-24, the polyester resin stipulated in the present invention is used as the clear resin composition. It turned out that the black metal plate excellent in corrosion resistance and workability is obtained by this.

Experimental Examples 8-1 to 8-8: Preparation of Black Metal Plate with Clear Layer

(Production of black metal plate)

In the same manner as in Experiment 6-1, a black metal plate was produced.

(Preparation of clear resin composition 2 (a))

A solvent was used in the same manner as in Experiment 2-16 except that the content of polyethylene wax was 1-12% by mass and the resin material obtained by mixing the polymer polyester resin and the crosslinking agent at 80:20 was 75.4-8.4% by mass. System clear resin composition 2 (a) was prepared.

(Production of black metal plate with clear layer)

The said solvent system clear resin composition 2 (a) was bar-coated on the single side | surface of the said black metal plate so that dry mass might be set to 2 g / m <^2> , and the black metal plate with a clear layer was produced. Table 8 shows the evaluation results of the obtained black metal plate with a clear layer.

It is excellent in corrosion resistance and abrasion resistance by containing 2-10 mass% of polyethylene wax in a clear resin composition from the comparison of Experimental example 8-1-8-8 and Experimental example 8-7-8-8, Moreover, it turns out that the black metal plate with a low friction coefficient is obtained.

Experimental Examples 9-1 to 9-12: Preparation of Black Metal Plate with Clear Layer

(Production of black metal plate)

In the same manner as in Experiment 6-1, a black metal plate was produced.

(Preparation of clear resin composition 2 (b))

The following rust inhibitors (A-B; Teika Co., Ltd., C-E; Fuji-Silysia Chemical Co., Ltd., F; Nissan Chemical Co., Ltd.) were used, and the content rate is 3-22 mass%, and is high molecular polyester A solvent-based clear resin composition 2 (b) was prepared in the same manner as in Experimental Example 2-16 except that the resin material obtained by mixing the system resin and the crosslinking agent at 80:20 was 70.4 to 89.4 mass%.

A: Tripolyphosphoric aluminum dihydrogen K-WHITE G105, particle size 2.3μm

B: tripolyphosphoric dihydrogen aluminum K-WHITE G730, particle size 2.3μm

C: calcium ion exchange silica silo mask 62-Ca 6%, particle size 2.8μm

D: calcium ion exchange silica silicia 530, particle size 2.7 μm

E: Calcium ion exchanged silica Silicia 710, particle size 2.8 μm

F: colloidal silica XBA-ST, particle diameter 10-20nm

(Production of black metal plate with clear layer)

On one side of the black metal plate, the solvent-based clear resin composition 2 (b) was bar coat-coated so as to have a dry mass of 2 g / m ² , thereby producing a black metal plate with a clear layer. Table 9 shows the evaluation results of the obtained black metal plate with a clear layer.

From the comparison of Experimental Examples 9-1 to 9-10 and Experimental Examples 9-11 to 9-12, a black metal plate excellent in corrosion resistance, workability, and appearance by containing 5 to 20% by mass of a rust preventive agent in the clear resin composition It can be seen that this is obtained.

Experimental Example 10-1-10-10: Production of the black metal plate with a back clear layer and the black metal plate with a front and back clear layer

(Preparation of Lower Extremity Treatment Composition)

To 55 parts by mass of acid colloidal silica ("Snowtex (registered trademark) O" manufactured by Nissan Chemical Co., Ltd.), 45 parts by mass of aluminum phosphate (manufactured by Yoneyama Chemical Co., Ltd.) and pure water were added to the acid colloidal silica To 100 mass parts in total, 0.5 mass part of polyacrylic acids ("Jurima AC-10-LP" by Nihon Junyaku Corporation) were added, 7.5 mass parts of silane coupling agents ("KBM403" by Shin-Etsu Chemical Co., Ltd.) were further added, The base treatment composition was prepared.

(Production of not processed metal plate)

The prepared base treatment composition was applied to a front and back surface of an electrogalvanized steel sheet (EG; Zn adhesion amount 20 g / m ² ) by a manual roll coat apparatus so as to adhere 0 to 120 mg / m ² as a dry mass, and the drying temperature was 60 ° C. at 60 ° C. It was made to dry super and the base metal plate was produced.

(Production of Black Composition)

After adding 357.4 mass parts of pure waters with stirring to 55.6 mass parts of ink matters ("super-absorbent ink made by Kuretake Co., Ltd.") as surface-treated carbon black, 71.3 mass parts of binder resin (a) precursors were added, and then colloidal 12.5 parts by mass of silica (Snowtex® XS) was added, and 1.3 parts by mass of silane coupling agent and 1.9 parts by mass of epoxrose K-2030E as an oxazoline group-containing polymer were added to the black composition. Black composition (5 mass parts of solid content concentration) containing 30 mass parts of surface-treated carbon black, 60 mass parts of binder resin (a), 10 mass parts of colloidal silica, and 5 mass parts (border outside) of a silane coupling agent in 100 mass parts. 500 parts by mass of%) was prepared.

(Formation of black layer)

The prepared black composition was apply | coated to the single side | surface (surface) of the base treatment metal plate so that it might become dry mass 1g / m <^2> by the bar coat coating apparatus, and it dried for 60 second at the drying temperature of 160 degreeC, and formed the black layer.

(Preparation of water-based clear resin composition for back side)

First, the emulsion (emulsion) of the ethylene-unsaturated carboxylic acid copolymer and the carboxylic acid polymer was prepared. That is, an ethylene-acrylic acid copolymer (“primachol (registered trademark) 5990I” manufactured by Dow Chemical Co., Ltd .; structural unit derived from acrylic acid) as an olefin-acid copolymer in an autoclave having an emulsification facility equipped with a stirrer, a thermometer, and a temperature controller. Mass%, mass average molecular weight (Mw): 20,000, melt index: 1300, acid value: 150) 200.0 parts by mass, a polymaleic acid aqueous solution ("Nonpol (registered trademark) PMA-50W" manufactured by Nichi Corporation); Mw: About 8.0 mass parts of 1100 (polystyrene conversion), 50 mass% product), 35.5 mass parts of triethylamine (0.63 equivalent with respect to the carboxyl group of an ethylene-acrylic acid copolymer), 6.9 mass parts of 48% NaOH aqueous solution (carboxyl of an ethylene-acrylic acid copolymer) 0.15 equivalents), 3.5 mass parts of tall oil fatty acid ("Hatorl FA3" manufactured by Harima Chemicals Co., Ltd.), and 792.6 mass parts of ion-exchanged water were added and sealed, and the mixture was cooled to 30 ° C at a high speed for 3 hours at 150 ° C and 5 atmospheres. Subsequently, 10.4 parts by mass of glycidoxy group-containing silane coupling agent (Momentive Performance Materials, Inc. (former name: GE Toshiba Silicon), Inc. "TSL8350": γ-glycidoxypropyltrimethoxysilane) 31.2 mass parts of mead (Mw: 2700, 40 mass% of solid content) and 72.8 mass parts of ion-exchange water were added, and it stirred for 10 minutes, and prepared the emulsion (emulsion) of an ethylene-unsaturated carboxylic acid copolymer and a carboxylic acid polymer (solid content concentration about) 20 mass%, measured according to JIS K 6833).

Next, to the obtained emulsion, a colloidal silica (a) having a surface area average particle diameter of 4 to 6 nm (nominal value) ("Snotex (registered trademark) XS" manufactured by Nissan Chemical Co., Ltd .; solid content concentration 20 mass%) and the surface area average particle diameter 10-20 nm (nominal value) colloidal silica (b) ("Snotex (registered trademark) 40" by Nissan Chemical Co., Ltd .; 40 mass% of solid content concentration) is added sequentially, and both are mixed well, and glycidoxy group Containing silane coupling agent ("KBM403" manufactured by Shin-Etsu Chemical Co., Ltd .; solid content concentration 100% by mass), followed by sodium metavanadate ("metavanadate soda" manufactured by Shinkou Chemical Co., Ltd.) as a metavanadate; Concentration of about 66% by mass) was added. In addition to this mixture, acrylic modified epoxy resin ("Modepix (registered trademark) 302" by Arakawa Chemical Co., Ltd .; solid content concentration 33.5 mass%) was added, and the water-based clear resin composition for back surfaces was prepared.

On the other hand, at the time of preparation of the water-based clear resin composition for back surface, the mixed amount (or mixing ratio) of each component is colloidal silica (a): colloidal silica (b) (mass ratio) = 50:50, inorganic component: resin component ( 5 mass parts (5 mass% in resin component) with respect to 95 mass parts of total solids in the said emulsion of the total solid of the said emulsion, and the total amount of acrylic modified epoxy resin) (mass ratio) = 30: 70-95: 5, ) And 10 parts by mass of the glycidoxy group-containing silane coupling agent based on 100 parts by mass of the total of the inorganic component and the resin component, and 1 part by mass of the metavanadate salt based on 100 parts by mass of the total of the inorganic component and the resin component.

(Preparation of Black Metal Plate with Back Clear Layer (Formation of Back Water Clear Layer))

The back surface aqueous clear resin composition was apply | coated to the back surface (ground treatment surface which does not have a black layer) which formed the black layer in the bar coat coating apparatus so that it might be set to a dry mass of 0.5 g / m <^2> , and drying temperature 170 degreeC It dried for 60 seconds, and the water-based clear layer for back surface was formed, and the black metal plate with a back surface clear layer (the metal plate which has a black layer on the surface, and a clear layer on the back surface) was produced.

(Preparation of surface solvent-based clear resin composition 5)

Dilution thinner (product made by Nippon Paint Corporation) at 76 mass parts of polyester urethane resin ("Viron UR-3500" made by Toyo Spinning Co., Ltd .; weight average molecular weight 40,000, Tg 10 degreeC, hydroxyl group 10mgKOH / g, solid content concentration 40 mass%) 200 mass parts of N thinner 450 ") were added, it stirred, and after melt | dissolution, 12.7 mass parts of crosslinking agents (" super becamine TD-126 "made by DIC: butylated benzoguamine resin; weight average molecular weight 600, solid content concentration 60%) were added, Stirring was continued to dissolve. Next, the solution which added and melt | dissolved 4.6 mass parts of acid hardening catalysts ("NACURE 5225" by Kusumoto Chemical Co., Ltd.) was previously added to 86.6 mass parts of dilution thinners, and was made into the mat agent ("MIBK silica slurry made by Fuji Silysia company"); solid content concentration 8 mass%) 10 mass parts and 10.2 mass parts of polyethylene wax ("X-20P-2" by a climate shellac company) were added. The obtained solvent-based clearing resin composition 5 consists of 76 mass% of base resins, 19 mass% of crosslinking agents, and 5 mass% of waxes, 4.6 mass% of acid hardening catalysts, and 2 mass% of a mat agent (silica) out of an edge. Will be used.

(Production (formation of surface solvent-based clear layer) of black metal plate with front and back clear layer)

The surface solvent type clear resin composition 5 was apply | coated to the surface (surface which has a black layer) of the said black metal plate with a back surface clear layer so that a dry mass might be set to 3 g / m <^2> using a bar coat coating apparatus, and it was made to dry temperature 230 degreeC. It dried for 60 second, and produced the black metal plate (metal plate which has a clear layer in both front and back surfaces) with a clear surface clear surface.

(Evaluation result of black metal plate with back surface clear layer, black metal plate with front and back surface clear layer)

Table 10 shows the evaluation results of the black metal plate with the back clear layer and the black metal plate with the front and back clear layers.

Experimental examples 11-1 to 11-9: Preparation of the black metal plate with a back clear layer and the black metal plate with a front and back clear layer

(Preparation of Lower Extremity Treatment Composition)

In the same manner as in Experiment 10-1, a base treatment composition was prepared.

(Production of not processed metal plate)

The prepared base treatment composition was applied to the front and back surfaces of the hot-dip galvanized steel sheet (GI; Zn adhesion amount 45 g / m ² ) using a manual roll coating apparatus so as to adhere from 0 to 120 mg / m ² as a dry mass, and the drying temperature was 60 ° C. at 60 ° C. It was made to dry super and the base metal plate was produced.

(Production of black metal plate with back clear layer)

A black metal plate with a backside clear layer was produced in the same manner as in Experimental Example 10-1 except that the underlying metal plate obtained above was used.

(Production of black metal plate with front and back clear layer)

A black metal plate with a front and back clear layer was produced in the same manner as in Experimental Example 10-1, except that the base metal plate obtained above was used.

(Evaluation result of black metal plate with back surface clear layer, black metal plate with front and back surface clear layer)

Table 11 shows the evaluation results of the black metal plate with the back clear layer and the black metal plate with the front and back clear layers.

Experimental Examples 12-1 to 12-8: Preparation of black metal plate with back clear layer and black metal plate with front and back clear layer

(Preparation of Lower Extremity Treatment Composition)

To 0-70 mass parts of acidic colloidal silica ("Snowtex (registered trademark) O" made by Nissan Chemical Co., Ltd.), 0-70 mass parts of aluminum phosphate (made by Yoneyama Chemical Co., Ltd.) and a pure water are added, and acidic colloidal silica and 0.5 mass parts of polyacrylic acids ("Jurima AC-10-LP" by Nihon Junyaku Corporation) are added with respect to a total of 100 mass parts of heavy acid aluminum, and a silane coupling agent ("KBM403" made by Shin-Etsu Chemical Co., Ltd.) 7.5 Mass parts were added to prepare an under treatment composition.

(Production of not processed metal plate)

The prepared base treatment composition was applied to the front and back of an electrogalvanized steel sheet (EG; Zn adhesion amount 20 g / m ² ) by a manual roll coat apparatus so as to adhere 60 mg / m ^{2 at a} dry mass and dried at 120 ° C. for 60 seconds. The base metal plate was produced.

(Production of black metal plate with back clear layer)

A black metal plate with a backside clear layer was produced in the same manner as in Experimental Example 10-1 except that the underlying metal plate obtained above was used.

(Production of black metal plate with front and back clear layer)

A black metal plate with a front and back clear layer was produced in the same manner as in Experimental Example 10-1, except that the base metal plate obtained above was used.

(Evaluation result of black metal plate with back surface clear layer, black metal plate with front and back surface clear layer)

Table 12 shows the evaluation results of the black metal plate with the back clear layer and the black metal plate with the front and back clear layers.

Experimental Examples 13-1 to 13-8: Preparation of Black Metal Plate with Back Clear Layer and Black Metal Plate with Front and Back Clear Layer

(Preparation of Lower Extremity Treatment Composition)

To 55 parts by mass of acid colloidal silica ("Snowtex (registered trademark) O" manufactured by Nissan Chemical Co., Ltd.), 45 parts by mass of aluminum phosphate (manufactured by Yoneyama Chemical Co., Ltd.) and pure water were added to the acid colloidal silica To 100 mass parts in total, 0-1.2 mass parts of polyacrylic acids ("Jurima AC-10-LP" made by Nihon Junyaku Corporation) are added, and 7.5 mass parts of silane coupling agents ("KBM403" made by Shin-Etsu Chemical Co., Ltd.) are further added. It added and prepared the base treatment composition.

(Production of not processed metal plate)

The prepared substrate treatment composition was applied to the front and back of an electrogalvanized steel sheet (EG; Zn adhesion amount 20 g / m ² ) by a manual roll coat apparatus so as to adhere 60 mg / m ^{2 at a} dry mass and dried at a drying temperature of 120 ° C. for 60 seconds. The base metal plate was produced.

(Production of black metal plate with back clear layer)

A black metal plate with a backside clear layer was produced in the same manner as in Experimental Example 10-1 except that the underlying metal plate obtained above was used.

(Production of black metal plate with front and back clear layer)

A black metal plate with a front and back clear layer was produced in the same manner as in Experimental Example 10-1, except that the base metal plate obtained above was used.

(Evaluation result of black metal plate with back surface clear layer, black metal plate with front and back surface clear layer)

Table 13 shows the evaluation results of the black metal plate with the rear clear layer and the black metal plate with the front and rear clear layer.

Experimental Examples 14-1 to 14-8: Preparation of Black Metal Plate with Back Clear Layer and Black Metal Plate with Front and Back Clear Layer

(Preparation of Lower Extremity Treatment Composition)

To 55 parts by mass of acid colloidal silica ("Snowtex (registered trademark) O" manufactured by Nissan Chemical Co., Ltd.), 45 parts by mass of aluminum phosphate (manufactured by Yoneyama Chemical Co., Ltd.) and pure water were added to the acid colloidal silica To 100 mass parts in total, 0.5 mass part of polyacrylic acids ("Jurima AC-10-LP" by Nihon Junyaku Corporation) are added, and 0-17 mass parts of silane coupling agents ("KBM403" made by Shin-Etsu Chemical Co., Ltd.) are further added. It added and prepared the base treatment composition.

(Production of not processed metal plate)

The prepared base treatment composition was applied to the front and back of an electrogalvanized steel sheet (EG; Zn adhesion amount 20 g / m ² ) by a manual roll coat apparatus so as to adhere 60 mg / m ^{2 at a} dry mass and dried at 120 ° C. for 60 seconds. The base metal plate was produced.

(Production of black metal plate with back clear layer)

A black metal plate with a backside clear layer was produced in the same manner as in Experimental Example 10-1 except that the underlying metal plate obtained above was used.

(Production of black metal plate with front and back clear layer)

A black metal plate with a front and back clear layer was produced in the same manner as in Experimental Example 10-1, except that the base metal plate obtained above was used.

(Evaluation result of black metal plate with back surface clear layer, black metal plate with front and back surface clear layer)

Table 14 shows the evaluation results of the black metal plate with the back clear layer and the black metal plate with the front and back clear layers.

Experimental Examples 15-1 to 15-10: Preparation of Black Metal Plate with Clear Layer

(Preparation of Lower Extremity Treatment Composition)

To 55 mass parts of acidic colloidal silica ("Snowtex (registered trademark) O" made by Nissan Chemical Co., Ltd.), 45 mass parts of aluminum phosphate (made by Yoneyama Chemical Co., Ltd.) and a pure water are added, and acid colloidal silica is being used. 7.5 mass parts of polyacrylic acids ("Jurima AC-10-LP" by Nihon Junyaku Corporation) are added with respect to a total of 100 mass parts of acid aluminum, and 7.5 mass of silane coupling agents ("KBM403" made by Shin-Etsu Chemical Co., Ltd.) are further added. Part was added to prepare an under treatment composition.

(Production of not processed metal plate)

The prepared base treatment composition was applied to the front and back of an electrogalvanized steel sheet (EG; Zn adhesion amount 20 g / m ² ) by a manual roll coat apparatus so as to adhere 60 mg / m ^{2 at a} dry mass and dried at 120 ° C. for 60 seconds. The base metal plate was produced.

(Preparation of clear resin composition 6)

Instead of polyester urethane resin (Vyron UR-3500), except using the following high molecular polyester resin, polyester urethane resin, or low molecular polyester resin (all are resin used in preparation of clear resin composition 4). , Solvent-based clear resin composition 5 was prepared in the same manner as in (Example of Experimental Example 10-1 (Preparation of Surface-Based Clear-Resin Composition 5)).

G: Byron 28SS, weight average molecular weight 15,000-20,000, Tg 68 degreeC, hydroxyl value 6.5

J: Super becolite M-6801-30, weight average molecular weight 15,000, Tg 72 degreeC, hydroxyl group 10.0

K: becolite 46-118, weight average molecular weight 1,500, Tg 20 ° C, hydroxyl group 120

L: Becolite M-6405-50, weight average molecular weight 2,500, Tg 42 degreeC, hydroxyl group 120

M: becolite M-6402-50, weight average molecular weight 2,500, Tg 10 ° C, hydroxyl group 120

O: Byron UR-3500, weight average molecular weight 40,000, Tg 10 ° C, hydroxyl group 10

P: Super becolite M-6805-40, weight average molecular weight 15,000, Tg 35 degreeC, hydroxyl group 10

Q: Super becolite M-6801-30, weight average molecular weight 15,000, Tg 72 ° C, hydroxyl group 10

(Production of black metal plate with clear layer)

A black metal plate with a clear layer was produced in the same manner as in Experimental Example 10-1 except for using the substrate treated metal plate obtained above and using the clear resin composition 6 obtained above. Table 15 shows the evaluation results of the black metal plate with a clear layer.

Claims (16)

Metal plate,
Has a black layer formed on at least one side of the metal plate,
The black layer is composed of 100 parts by mass of a black composition containing 22 to 60 parts by mass of surface-treated carbon black coated with water-soluble resin and 20 to 73 parts by mass of binder resin,
The dry mass of the black layer is 0.28 ~ 1.5g / m ² ,
The black metal plate whose blackness (L * value) of the said black layer surface is 24 or less. The method of claim 1,
The black metal plate wherein the binder resin is a polyethylene resin and / or a polyurethane resin. The method of claim 2,
The polyethylene resin is composed of an olefin-α, β-unsaturated carboxylic acid copolymer, an α, β-unsaturated carboxylic acid polymer, and an oxazoline group-containing polymer,
The black metal plate containing 2-8 mass parts of said oxazoline group containing polymers with respect to a total of 100 mass parts of an olefin- (alpha), (beta)-unsaturated carboxylic acid copolymer and an (alpha), (beta)-unsaturated carboxylic acid polymer. The method of claim 3, wherein
The polyurethane resin is a carboxyl group-containing polyurethane resin, at least one kind selected from the group consisting of tolylene diisocyanate, diphenylmethane diisocyanate and dicyclohexyl methane diisocyanate A black metal plate obtained by chain-extending a urethane prepolymer composed of an isocyanate component and a polyol component containing a 1,4-cyclohexanedimethanol, a polyether polyol, and a polyol having a carboxyl group with a chain extender. The method of claim 1,
The black metal plate in which the said black composition is prepared by adding the said binder resin to the aqueous solution containing carbon black and the said water-soluble resin. The method of claim 1,
The black metal plate which further contains 5-20 mass parts of colloidal silica in 100 mass parts of said black compositions. The method of claim 1,
The said metal plate further has a base layer previously formed by base treatment on at least one side, and the said base layer is dry mass 12- with the base treatment composition containing aluminum phosphate, colloidal silica, and polyacrylic acid. A black metal plate formed to be 117 mg / m ² . The method of claim 7, wherein
In the said base treatment composition, the content rate of aluminum phosphate and colloidal silica is aluminum phosphate: colloidal silica (mass ratio) = 35: 65-65: 35, and polyacrylic acid is a compound of aluminum phosphate and colloidal silica. The black metal plate contained 0.2-1.0 mass part with respect to 100 mass parts in total. The method of claim 7, wherein
The black metal plate which contains 3-15 mass parts of silane coupling agents further with respect to a total of 100 mass parts of aluminum heavy acid acid and colloidal silica in the said base treatment composition. The method of claim 1,
The black metal plate which has a clear layer further on the said black layer, dry mass of the said clear layer is 1-4 g / m <^2> , and blackness (L * value) of the said clear layer surface is 24 or less. 11. The method of claim 10,
The black metal plate in which the clear resin composition which forms the said clear layer contains the weight average molecular weights 10,000-25,000, Tg 35-75 degreeC, and high molecular weight polyester-based resin of 5 mgKOH / g or more of hydroxyl groups. 11. The method of claim 10,
The clear resin composition forming the clear layer comprises a polymer polyester resin having a weight average molecular weight of 10,000 to 25,000 and a Tg of 35 to 75 ° C, a low molecular polyester resin having a weight average molecular weight of 1,500 to 2,500 and a Tg of 10 to 45 ° C. And black metal sheet containing a mixed resin having an average hydroxyl value of 25 mg KOH / g or more formed by mixing with a high molecular polyester resin: low molecular polyester resin (mass ratio) = 8: 2 to 6: 4. 11. The method of claim 10,
The black metal plate in which the clear resin composition which forms the said clear layer contains the weight average molecular weight 30,000-40,000, Tg-3-23 degreeC, and the polyester urethane resin whose hydroxyl group is 10 mgKOH / g or less. 11. The method of claim 10,
The clear resin composition forming the clear layer comprises a polyester urethane resin having a weight average molecular weight of 30,000 to 40,000, a Tg-3 to 23 ° C, a low molecular weight polyester resin having a weight average molecular weight of 1,500 to 2,500 and a Tg of 10 to 45 ° C. And black urethane metal sheet containing a mixed resin having an average hydroxyl value of 25 mgKOH / g or more formed by mixing a polyester urethane resin: low molecular weight polyester resin (mass ratio) = 2: 8 to 4: 6. The method of claim 11,
The black metal plate which further contains 2-10 mass parts of polyethylene wax in 100 mass parts of said clearing resin compositions. The method according to any one of claims 11 to 15,
The black metal plate which further contains 5-20 mass parts of rust preventive agent in 100 mass parts of said clearing resin compositions.

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