JP4911741B2 - Metal container excellent in slipperiness and method for producing the same - Google Patents

Description

＊１：微粉シリカ（無色クリアー）
＊２：石油系炭化水素
＊３：ドライヤー、抑制剤などの合計
【００１９】
［塗装］
それぞれのインキ単独をＤＩ缶の側面全体に、乾燥時の厚さ０．８μｍ塗布し、ついでその表面をクリアーニス（乾燥厚さ６μｍ）を塗装し、１９０℃、３０秒の１次や着付けを行う。第１次焼き付けを行う。次いで内面塗装した後さらに２００℃、６０秒の第２次焼き付けを行った。
比較例として、インキを塗布せずクリアーニス塗装（乾燥厚さ６μｍ）をし、上記と同じ第１次焼き付けを行い、次いで内面塗装し、さらに第２次塗装したもの準備した。
これらのＤＩ缶をそのままおよび温水シャワー（５０℃、５ふん、８リットル／分）後の静摩擦係数を測定した。
【００２０】
［測定法］
経時変化の影響を避けるため、印刷焼き付け後翌週（７日後）に測定を行った。測定は静摩擦係数測定器（Ｔｙｐｅ ＨＥＩＤＯＮ−１０）を用い、３缶を１組として、それを俵積みできる缶固定台座を試料台上に、下側の２缶のネック部が右側に来るように、上側の１缶はネック部が左側になるように積み重ねる。上の缶の底部に光遮光板を密着させておき、試料台が動いて角度が大きくなり、上に載せた缶が動き始めた点で光センサーによって試料台が停止するようにした。
この時の試料台の角度より摩擦係数目盛りで（ｔａｎθ＝μ）を読みとり、静摩擦係数とした。
【００２１】
このようにして、各色毎に１０回のテストを行った。印刷したままのものの測定結果を表２におよび印刷し、温水シャワー後のものの測定結果を表３に示す。
【００２２】
【表２】

【００２３】
【表３】

【００２４】
【発明の効果】
従来、金属容器の印刷において、インキやクリアーニスのそのいずれかにワックスを配合することは行われていたが、容器印刷のデザインにより必ずその全面にワックスを配合したインキによる印刷をした後に、ワックスを配合したクリアーニスでオーバーコートが行われてはいなかった。特に着色が行われないデザインの容器においては、その部分はクリアーニスのみでコーティングされているだけであったが、本発明においてはこの部分に無色または透明なワックスを配合したインキにより印刷を行うことによりワックスの表面へのブリーディングを確保することにより滑り性の優れた金属容器を製造することができた。[0001]
BACKGROUND OF THE INVENTION
The present invention is an aluminum can in which clogging does not occur in the flow of a container in a high-speed production line or content filling line, and slipping is not lost even when wax is washed away in a hot water shower or sterilization / drying process. The present invention relates to a printed metal container with improved slipperiness, which is manufactured by processing a thin metal plate such as a steel can, and a method for manufacturing the same.
[0002]
[Prior art]
The outer surface of metal cans, including cans for beverages such as beer cans and juice cans and cans for various foods, are printed with letters, designs, etc. for the purpose of protecting the material and giving aesthetics. Furthermore, overcoating with a clear varnish is performed on the surface.
For example, in a three-piece can composed of a bottom plate, a side plate, and a lid, a can is manufactured after printing on a metal thin plate corresponding to the side plate before can making and overcoating with clear varnish. In this case, these coating films require flexibility enough to withstand processing when being formed into cans, and coating film hardness that is not damaged by friction with the molding machine or the can conveyance line.
[0003]
In the case of a two-piece can consisting of a can body and a cover plate, a can body consisting of a bottom plate and a side plate is usually made by deep drawing and ironing after punching a thin metal plate, and then printed on the side plate portion to produce a clear varnish. Overcoating is performed, and further internal coating is performed. In this case, drying and baking are performed after surface printing and overcoating, and drying and baking are performed again after the inner surface coating.
When the contents are beverages or foods, after filling the metal container with the contents, retort processing (retort processing for sterilization of the container contents) is performed, and washing with a hot water shower and attached water droplets Drying is performed.
[0004]
These printed metal containers use a printing ink or a clear varnish blended with a sliding additive (wax) in order to ensure the sliding property of the container and prevent clogging in the line flow. The printed metal container ink and clear varnish are dried and baked after printing. In this process, the wax blended in the ink and clear varnish bleeds to the coating surface. , Slipperiness is imparted. In particular, clear varnish painted on the bottom plate part that requires slippery contains a large amount of wax to maintain high slipperiness, but the ink and clear varnish for the side plate will whiten the printed part. The blending amount is limited, and for this reason, the slipperiness of the side plate portion tends to be insufficient.
[0005]
In the case of normal beverages and foods, in the content filling line, after filling the content, retort treatment, sterilization by hot water shower, washing, and then drying of water droplets attached to the metal container are performed. In this process, the wax layer raised by drying and baking is easy to flow down, and the printing metal containers that have lost the wax layer on the surface are not slippery on the production line and content filling line that have been accelerated. There was a clogging on the line.
In particular, in metal containers that have many parts that are not printed with ink on the base and many parts that have only clear varnish, the slipperiness decreases significantly after retorting, hot water showering, and water droplet drying. Therefore, clogging of the line was likely to occur, and scratches and dents were easily generated on the metal container itself.
[0006]
[Problems to be solved by the invention]
The present invention is capable of maintaining slipperiness even after clogging of metal containers in a high-speed production line and contents filling line and after hot water shower after contents filling, and in particular, a metal having a design with a small printing area. An object of the present invention is to provide a metal container having a greatly improved sliding property.
[0007]
[Means for Solving the Problems]
The present invention
[1] The entire side surface of the metal container is directly coated with colored ink containing wax to provide a printing layer, and from the portion directly coated with colorless or transparent ink containing wax to provide a printing layer. A metal container characterized in that the surface of these printing layers is coated with a clear varnish layer to which a wax is added, and the ink printing layer and the clear varnish layer are baked.
[2] The metal container according to [1], wherein the metal container is a two-piece can or a three-piece can.
[3] The metal container according to [1], wherein the baking temperature is 190 to 200 ° C., and the metal container is a two-piece can.
[0008]
[4] The metal container according to the above [1], wherein the baking temperature is 190 to 215 ° C, and the metal container is a three-piece can.
[5] The metal container according to any one of [1] to [4], wherein the wax is a wax composed of at least one of vegetable wax, animal wax, mineral wax and synthetic wax.
The above objective was achieved by developing
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the metal container subject to the present invention include aluminum cans (DI cans) for drinking water such as beer, soft drinks, teas, steel cans (mainly 3 piece cans), etc. It is a metal container that is printed on the surface of cans such as piece cans and cans of confectionery and is filled in an automatic filling line. In particular, since the material is soft, a remarkable effect can be exerted in an aluminum can that easily dents and deforms easily.
[0010]
Conventionally used oil-based or water-based inks are used as printing inks. In this case, be sure to use a wax compound.
As the ink, a colored pigment or dye, a colorless and transparent pigment (such as silica), and a synthetic resin are blended, and an organic solvent is used in the case of oiliness, and an aqueous solvent is used in the case of water.
The resin used in the water-based ink is not limited, but melamine resin, benzoguanamine resin, and the like are used.
[0011]
In the case of water-based ink, oil-soluble epoxy resin, urethane resin, vinyl ester = epoxy acrylate resin, polyester resin, acrylic resin, alkyd resin, aqueous emulsion of phenol resin, acrylic / amino type, polyester / amino type, epoxy Esters / amino resins are used, and melamine resins, benzoguanamine resins, and the like are used as amino resins.
In the case of oil-based inks, thermosetting resins such as oil-soluble epoxy resins, urethane resins, vinyl ester = epoxy acrylate resins, polyester resins, acrylic resins, alkyd resins, and phenol resins are used.
The pigment used is the same as that of the conventional ink, and silica or the like is used as the colorless pigment. The clear varnish may be the same as the conventional product, and there is no particular limitation.
[0012]
A wide range of waxes can be used for the ink and the clear varnish. Animal waxes such as beeswax, spermaceti, beef tallow, lanolin, mineral waxes such as microcrystalline wax, vegetable waxes such as carnauba wax, polyethylene wax, silicone resin (polyorganosiloxane), synthetic wax, Teflon And synthetic waxes such as polyethylene oxide. Of these, carnauba wax, silicone resin, and polyethylene wax are preferred.
[0013]
The above wax must be blended with all of the ink and clear varnish, but the blending amount into the clear varnish to be applied to the container bottom plate portion is blended with the necessary amount that gives the slipperiness required by the bottom plate. Although good, the amount of ink applied to the printing surface of the side plate and the amount added to the clear varnish has an upper limit in order not to whiten the printing surface. The upper limit amount varies depending on whether the ink is oily or water-based, or the type of clear varnish and wax, and therefore cannot be given a constant value. Since the upper limit of these can be determined by a simple test, it is necessary to test each. When the wax has good affinity for ink or clear varnish, about 0.5 to 10% by weight, preferably 1 to 5% by weight, and when the affinity is poor, about 0.1 to 3% by weight, preferably 0.5 to 2% by weight is blended. These may be used alone or in combination of two or more.
[0014]
In the present invention, when printing with a coloring ink, there is a portion that is not printed due to the design or pattern, and it is necessary to print this portion with an ink containing a colorless or transparent wax. That is, the side plate of the metal container must be printed on the entire surface with colored, colorless or transparent ink.
As a result, the bottom surface of the metal container is coated with clear varnish containing a large amount of wax, and the side plate of the metal container is printed with ink mixed with wax without leaving the entire surface, and the surface is coated with clear varnish mixed with wax. As a result, the entire surface of the side plate is printed with printing ink and overcoated with a clear varnish containing a wax.
[0015]
After applying printing ink and clear varnish as described above, in a three-piece can, a thin metal plate coated with ink and clear varnish is baked at a temperature of about 190 to 215 ° C. for about 8 to 10 minutes, for example. Further, after internal coating, baking is performed again at about 190 to 215 ° C. for about 8 to 10 minutes. In the case of a two-piece can, after applying ink and clear varnish to the container body, for example, primary baking is performed at a temperature of about 190 to 200 ° C. for about 15 to 60 seconds. Secondary baking is performed for about 30 to 120 seconds at about ° C.
As a result, the wax blended in printing ink, clear varnish, etc. bleeds to the surface, gives the metal containers slipperiness, and gives the slipperiness required in high-speed production lines and content filling lines. This can prevent clogging and traffic jams.
[0016]
In addition, when wax is added to both printing ink and clear varnish in this way, the outflow of wax in processes such as hot water shower, retort treatment, and water droplet drying after treatment is inevitable, but at the same time, There will be a bleeding of the wax from the ink and clear varnish, and the required slip will be retained. In particular, since not only clear varnish but also wax is blended in the ink, even if some wax bleeds on the surface, it seems to be hardly affected.
[0017]
【Example】
[Aluminum can]
A 350 ml (can barrel diameter 211), DI can made of 3004 aluminum alloy was used.
[wax]
The ink was blended with 3% by weight of paraffin wax, and clear varnish (polyester) was blended with 0.6% by weight of silicone resin wax and 1% by weight of paraffin wax.
[0018]
[ink]
The ink having the composition shown in Table 1 was used.
[Table 1]

* 1: Fine powder silica (colorless clear)
* 2: Petroleum hydrocarbons * 3: Total of dryers, inhibitors, etc.
[Painting]
Each ink alone is applied to the entire side of the DI can with a thickness of 0.8μm when dried, and then the surface is coated with clear varnish (dry thickness of 6μm). Do. First baking is performed. Next, after the inner surface was coated, secondary baking was further performed at 200 ° C. for 60 seconds.
As a comparative example, a clear varnish coating (dry thickness 6 μm) was applied without applying ink, and the same primary baking as described above was performed, followed by inner surface coating and further a second coating.
The static friction coefficient of these DI cans was measured as it was and after a hot water shower (50 ° C., 5 minutes, 8 liters / minute).
[0020]
[Measurement method]
In order to avoid the influence of the change with time, the measurement was carried out in the following week (after 7 days) after printing and printing. Use a static coefficient of friction measuring device (Type HEIDON-10) for the measurement, so that 3 cans can be set as 1 set, and the can fixing pedestal on which the cans can be stacked is placed on the sample table, and the lower two necks are on the right side. The upper cans are stacked so that the neck is on the left side. A light-shielding plate was placed in close contact with the bottom of the upper can, and the sample stage was moved to increase the angle, and the sample stage was stopped by the optical sensor when the can placed on the top began to move.
The coefficient of friction (tan θ = μ) was read from the angle of the sample stage at this time and used as the coefficient of static friction.
[0021]
In this way, 10 tests were performed for each color. The measurement results of the printed products are printed in Table 2, and the measurement results after the hot water shower are shown in Table 3.
[0022]
[Table 2]

[0023]
[Table 3]

[0024]
【Effect of the invention】
Conventionally, in printing on metal containers, it has been practiced to add wax to either ink or clear varnish. The overcoat was not performed with the clear varnish which blended. In the case of a container that is not particularly colored, the part was only coated with clear varnish, but in the present invention, this part is printed with ink containing a colorless or transparent wax. Thus, it was possible to produce a metal container having excellent slipperiness by ensuring the bleeding of the wax on the surface.

Claims (5)

  The entire side surface of the metal container consists of a part that is directly coated with colored ink containing wax and a printed layer, and a part that is directly coated with colorless or transparent ink containing wax and is provided with a printed layer. A metal container, wherein the surface of the printing layer is coated with a clear varnish layer to which a wax is added, and the ink printing layer and the clear varnish layer are baked.   The metal container according to claim 1, wherein the metal container is a two-piece can or a three-piece can.   Baking temperature is 190-200 degreeC and a metal container is a 2 piece can, The metal container of Claim 1 characterized by the above-mentioned.   Baking temperature is 190-215 degreeC, A metal container is a 3 piece can, The metal container of Claim 1 characterized by the above-mentioned.   The metal container according to any one of claims 1 to 4, wherein the wax is a wax composed of at least one of vegetable wax, animal wax, mineral wax and synthetic wax.