DE4432225A1 - Aluminum effect paints and their use for painting packaging - Google Patents

Abstract

Disclosed are pigments and pigment mixtures consisting essentially of the following components (in percentages of the total quantity of pigment mixture): (a) 0-90 % by weight white nacreous pigment; (b) 0-90 % by weight bismuth oxichloride pigment; (c) 0-90 % by weight aluminium pigment; and (d) 0-90 % by weight white pigment. The following conditions apply: (i) the weight percentages must always add up to 100; (ii) component (a) must be present in the pigment mixture if component (b) is not present and vice versa; and (iii) component (c) must be present in the pigment mixture if component (b) is not present. The proposed pigment mixtures are used to produce aluminium effect paints which, on hardening on steel containers, have the appearance of an aluminium metal surface.

Description

The present invention relates to new ones Aluminum metal effect paints containing one or more Binders and pigments or pigment mixtures, which essentially out

• A) white pearlescent pigment a) and aluminum pigment c),
• B) white pearlescent pigment a), aluminum pigment c) and White pigment d),
• C) bismuth oxychloride pigment b) or
• D) bismuth oxychloride pigment b) and pearlescent pigment a), aluminum pigment c) and / or white pigment d) consist.

Packaging containers such as cans, tubes, canisters or Buckets, which are often referred to as packaging generally point to their outsides a paint job, which is primarily the Corrosion protection and the decorative design of the Serves cans. The choice of decorative paints is aimed also depending on whether the packaging made of steel or Made of aluminum sheet. Because one and the same paint becomes another optical on a steel sheet Make an impression than on aluminum. It is therefore for steel surfaces different paints than for aluminum to choose surfaces if you have the same wants to achieve a decorative effect.

Meanwhile, with packaging, especially with drinks cans, aluminum because of its beneficial application and decorative properties as Material on the advance and steel too outperform. The customers of the packaging manufacturers ver therefore increasingly tie in with the visual impression of  Aluminum packaging ideas of higher quality and technological and ecological progress. Because of that more and more steel packaging manufacturers are also trying their market shares by simulating the optical To secure the impression of an aluminum surface on steel. Because it is not easily possible for them, theirs Convert production from steel to aluminum.

Aluminum metal effect paints are in the automotive sector or in the general industrial painting sector has been known for a long time (Glasurit manual paints and coatings BASF Colors and Fibers AG, Curt R. Vincentz Verlag, Hanover, 1984, pages 468 to 471 and 538 to 541; EP-A-0 321 470). These well-known aluminum effect paints are used for the production of coatings used which is the well-known brilliant metallic effect with a particular expression of the individual Show aluminum plate. However, they cannot optical impression of an aluminum metal surface awaken.

The object of the present invention is to create a new one To find aluminum metal effect paint, which the Disadvantages of the aluminum effect lacquers of the prior art Technology no longer exhibits, but according to its Hardening on steel gives the visual impression of a Aluminum metal surface awakened. Beyond that the new aluminum metal effect paint in the for steel Emballagen usual and known manner for example can be applied by roller coating, so that the existing production lines cannot be converted need excellent mechanical after curing and have anti-corrosive properties and with the same decorative varnishes can be printed as they are can also be used for aluminum surfaces.  

Accordingly, the aluminum metal mentioned above effect paint found which one or more bin contains agents and pigments or pigment mixtures, which essentially consists of

• A) white pearlescent pigment a) and aluminum pigment c),
• B) white pearlescent pigment a), aluminum pigment c) and White pigment d),
• C) bismuth oxychloride pigment b) or
• D) bismuth oxychloride pigment b) and pearlescent pigment a), aluminum pigment c) and / or white pigment d) consist.

A new process for the production of Surfaces that give the visual impression of Awaken aluminum metal, found.

Furthermore, new pigment mixtures were found which has a particularly good visual impression effect.

An essential part of the invention Aluminum metal effect paint is the effect Pigment or the effect pigment mixture.

The first new one to be used according to the invention Pigment mixture (A) consists essentially of at least one white pearlescent allspice (a) and at least one aluminum pigment (c). In general one pigment is sufficient to achieve the invention to achieve appropriate effect. However, it can anyway already very good visual impression further optimized when two or three white pearlescent pigments (a) can be used at the same time. The same applies to that Aluminum pigment (c). In special cases, each more than four pigments of the same type can be used.  

The weight ratio of white pearlescent pigment (a) Aluminum pigment (c) can be used within wide limits can be varied. An advantage according to the invention is a Weight ratio of (a) to (c) from 15: 1 to 1: 3, advantageously 10: 1 to 1: 1, in particular 9: 1 up to 2: 1.

Examples of suitable ones to be used according to the invention white pearlescent pigments (a) are with titanium dioxide or Titanium and tin dioxide coated mica. Pigments of this type are common and known and commercially available at the trademark Iriodin® from Merck, Darmstadt, available.

Examples of suitable aluminum pigments (c) are commercially available aluminum pigments, which in the form are sold by pigment pastes, such as Sparkle Silver 7005 AR from Silberline, Leven, Scotland.

The pigment mixture (A) is in the invention Aluminum metal effect paint in an amount of, referred on the effect paint, up to 15, advantageously 0.3 to 10, in particular 1 to 8 wt .-% contain.

The second to be used according to the invention Pigment mixture (B) consists essentially of the pearlescent pigments (a) and Aluminum pigments (c) and at least one white pigment (d). Examples more suitable according to the invention White pigments (d) used are the commercially available Pigments based on barium sulfate or titanium dioxide, especially rutile.

Several white pigments (d) can be used simultaneously used to produce the new pigment mixture (B)  will. In general, however, the use of a Pigments (d) sufficient.

The weight ratio of the pigments (a): (c): (d) can be varied within wide limits. According to the invention, it is advantageous to weight to choose ratios so that, based on the Pigment mixture (B) the following weight percentages result in:

• a) 1 to 90% by weight of pearlescent pigment,
• c) 1 to 80 wt .-% aluminum pigment and
• d) 1 to 80% by weight of white pigment.

The weight percentages always add up to 100 % By weight. It is also advantageous according to the invention none of the components in an amount less than 5 % By weight to use.

The pigment mixture (B) is in the invention Aluminum metal effect paint in an amount of, referred on the effect paint, up to 15, advantageously 0.3 to 10, in particular 1 to 6 wt .-% contain.

According to the invention, at least one bismuth toxi is also used chloride pigment (b or C) used. Pigments (b or C) are commercially available. An example of an invention according to particularly suitable pigments (b or C) Mearlite® pearlescent by H. Costenoble in Eschborn.

The bismuth oxychloride pigment (b or C) is in that aluminum metal effect paint according to the invention in one Amount of, based on the effect varnish, up to 15, advantageously 0.3 to 10, in particular 1 to 8 % By weight.  

The third new pigment to be used according to the invention mixture (D) consists essentially of at least one of the bismuth oxychloride described above pigments (b) and at least one of the above described pearlescent pigments (a), at least one the aluminum pigments described above (c) and / or at least one of those described above Bismuth pigments (d).

The components (b) and (a), (c) and / or (d) of the Pigment mixture (D) according to the invention can in the different ways and in the difference most diverse proportions combined will. It is essential to the invention that the resul based variants (D1) to (D7) according to the invention:

• D1) (b) + (a),
• D2) (b) + (c),
• D3) (b) + (d),
• D4) (b) + (a) + (c),
• D5) (b) + (c) + (d),
• D6) (b) + (a) + (d) and
• D7) (b) + (a) + (c) + (d);

provide an aluminum metal effect paint, which according to its curing on a steel surface Gives the impression of an aluminum metal surface. Of the A person skilled in the art can therefore use suitable compositions find an orientation trial. According to The new pigment mixtures (D), which, based on their respective total, the following Have composition:

• D1) 10 to 90 wt .-% bismuth oxychloride (b) and
  10 to 90% by weight pearlescent pigment (a)
• D2) 20 to 90% by weight bismuth oxychloride (b) and
  10 to 80% by weight aluminum pigment (c)
• D3) 20 to 90 wt .-% bismuth oxychloride and
  10 to 80% by weight white pigment (d)
• D4) 1 to 90% by weight bismuth oxychloride (b),
  1 to 90% by weight of pearlescent pigment (a) and
  1 to 80% by weight aluminum pigment (c),
  with the proviso that the weight percentages add up to 100% by weight, it being advantageous according to the invention not to use any of the components in an amount of less than 5% by weight.
• D5) 1 to 90% by weight bismuth oxychloride (b),
  1 to 80 wt .-% aluminum pigment (c) and
  1 to 80% by weight of white pigment (d),
  with the proviso that the weight percentages add up to 100% by weight, it being advantageous according to the invention not to use any of the components in an amount of less than 5% by weight.
• D6) 1 to 90% by weight bismuth oxychloride (b), 1 to 90% by weight pearlescent pigment (a) and
  1 to 80% by weight of white pigment (d),
  with the proviso that the weight percentages add up to 100% by weight, it being advantageous according to the invention not to use any of the components in an amount of less than 5% by weight.
• D7) 1 to 90% by weight bismuth oxychloride (b),
  1 to 90% by weight of pearlescent pigment (a) and
  1 to 80 wt .-% aluminum pigment (c) and
  1 to 80% by weight of white pigment (d),
  with the proviso that the weight percentages add up to 100% by weight, it being advantageous according to the invention not to use any of the components in an amount of less than 5% by weight.

The pigment mixtures (D) according to the invention are in the aluminum metal effect paint according to the invention in one Amount of, based on the effect varnish, up to 15, advantageously 0.3 to 10, in particular 0.5 to 8 % By weight.

The preparation of the pigment mixtures according to the invention (A), (B) and (D) have no special features, but with the help of pigment processing and paint production usually used mix procedure carried out. It is also possible, however Components (a) to (d) of the pigment according to the invention mixtures in the manufacture of the invention Add aluminum metal effect paints individually. Here the components (a) to (d) are generally in a common and known form of processing, for example in pasty form used. Of the contains aluminum metal effect paint according to the invention also components as they are for a metallic effect paint are common and known.

Examples of suitable ingredients are waxes and Binder.

Examples of well-suited waxes are commercially available Waxes such as montan waxes, polyethylene waxes, polymer dispersions, natural waxes or ethylene / vinyl acetate Copolymers. Examples particularly well suited Waxes are the Cerafac® waxes from BYK Cera, Wesel. The waxes are in the alumi according to the invention nium metal effect paint in an amount of, based on the effect varnish, 0.09 to 3, advantageously 0.15 to 2 and in particular contain 0.2 to 1 wt .-%.  

Examples of well-suited binders are the commercial ones usual binders such as modified and unmodifi graced polyester, aminoplast resins, in particular Melamine resins, epoxy resins, polyacrylate resins and Phenol formaldehyde resins, of which the modified Polyester, the melamine resins and the epoxy resins in particular are well suited.

An example of a particularly well suited one modified polyester is the commercial product Uralac® CP 1074 SC from DSM Resine France, Bezons, Cedex, France.

Examples of particularly suitable melamine resins are the resins sold under the Maprenal® MF 900, 910, 915, 920 and 927 from Hoechst AG in Frankfurt are sold.

An example of a particularly well suited epoxy resin is Epikote® 1001 from Shell.

According to the invention, it is advantageous to use a binder mixture of at least one of the above described benen modified polyester, at least one of the melamine resins described above and at least one of the epoxy resins described above use. Here, the proportions of individual binders varied within wide limits will. However, it is advantageous in terms of Total amount of binder,

• 50 to 90% by weight of modified polyester,
• - 1 to 20 wt .-% of melamine resin and
• - 5 to 30 wt .-% of epoxy resin

to use because this is particularly advantageous aluminum metal effect paints according to the invention result.

In the aluminum metal effect paints according to the invention the binders are contained in quantities as they are for Metallic effect paints are common in themselves. However, they are advantageously used in an amount of based on the effect varnish, 20 to 60, in particular 25 up to 50 wt .-% used.

The aluminum according to the invention also contains metallic effect lacquer still common and known solvents. Their selection is primarily based on the Solubility properties of the used Binder, so that the person skilled in the art suitable Propose solvents based on their expertise can. Examples of particularly advantageous solvents are butyl glycol and butyl diglycol acetate.

In the aluminum metal effect paints according to the invention are the solvents in an amount of, based on the Effect paint, 20 to 80, advantageously 30 to 70 and contain in particular 40 to 65 wt .-%.

Furthermore, the aluminum according to the invention can metallic effect lacquer still other common and known Additives such as wetting or leveling agents or agents to control the rheology in conventional and known Amounts included.

The production of the aluminum metal according to the invention effektlacks offers no special features, but rather takes place according to the mixing process, as in the field paint production are common and known. So be the components of the  aluminum metal effect paint according to the invention in the the desired quantities in a suitable container weighed and then homogenized. As beneficial the use of high-speed stirrers has proven itself here. The pigments (a) to (d) or pigment mixtures (A), (B) and (D) according to the invention together with the binders and the rest of the stock share the aluminum metal effect paint according to the invention be fed to the container. However, it is from Advantage of some of the binders and the rest Submit paint components, the pigments (a) to (d) or the pigment mixtures (A), (B) or (D) with solvent soak up and only then admit. After that the remaining binders and the rest other ingredients added, which in specialist circles too is referred to as Auflacken.

The aluminum metal effect paint according to the invention is distinguished good storage stability and processing availability from what its industrial use is a big advantage. So larger quantities can be used Processing can be made without the need for longer Service life is a settling or segregation of the paint components would be feared.

The aluminum metal effect paint according to the invention is suitable excellent for coating substrates any kind, especially of packaging and here before especially for the outer coating of cans or the like. However, it can also be used for interior coating will. The packaging can be from the below different materials exist and the under have a wide variety of geometries. As materials come especially black plate, tin plate and various iron alloys, which ones  optionally with a passivation layer Base of nickel, chrome and zinc compounds are. The packaging can be in finished form or in Form of half-can parts such as hulls and lids, as three-piece or as two-piece ironed deep-drawn drawn or otherwise deep-drawn cans such as Beverage or food cans are coated.

The application of the aluminum metal according to the invention methodologically, effect paint has nothing special units, but takes place with the help of the order proceed as usual and known in the paint field are like rolling, knife coating, brushing, roller coating, Splash, flood or dive. It is according to the invention an advantage, the aluminum metal effect paint in one Layer thickness from 1 to 40, advantageously 2 to 35 and especially 3 to 30 micrometers on the packaging apply and at an object temperature of 150 to 400, in particular 180 to 250 ° C for 10 s to 10 min, advantageously 30 s to 5 min and in particular Cure for 50 s to 1 min 30 s.

After hardening gives the invention Aluminum metal effect paint the coated Surfaces, especially the packaging surfaces, the appearance of an aluminum metal surface. also it offers excellent corrosion protection and it can easily be overpainted with printing inks will. With regard to hardness, elasticity, adhesion, Non-porous and pasteurization and solvent it turns out to be the usual and known packaging varnishes as equal if not even considered superior.

Examples Examples 1 to 6 The production and use of the invention Aluminum metal effect paints General manufacturing instructions

Part of the binder, the wax and the Solvents were weighed into a stirred tank and homogenized with a high-speed stirrer. After that was the pigment mixture according to the invention or the Bismuth oxychloride pigment with butyl diglycol acetate dough and after stirring for 20 minutes with a portion of binders, wax and solvents mixed. The resulting mixture was washed with a High-speed stirrer homogenized and in the stirred tank given. After 10 minutes of homogenization, the remaining amounts of binder, wax and solvent lacquered.

The resulting aluminum metal according to the invention effect paint was applied to the hulls by roller coating two-piece tin cans in a layer thickness of 7 up to 12 micrometers and applied for 60 s Branded 200 ° C object temperature. The resulting one Surface was assessed visually by looking at it visual impression with the hull of an unpainted Aluminum can compared. All of the invention Aluminum metal effect paints gave the desired optical impression of an aluminum surface.

The table gives an overview of the material Composition of the invention Aluminum metal effect paints of Examples 1 to 6.  

table

Composition of the aluminum metal effect lacquers according to the invention of Examples 1 to 6

Claims (20)

1. Aluminum metal effect paints containing one or more binders and pigments or pigment mixtures, which essentially consist

• A) white pearlescent pigment (a) and aluminum pigment (c)
• B) white pearlescent pigment (a), aluminum pigment (c) and white pigment (d),
• C) bismuth oxychloride pigment (b) or
• D) bismuth oxychloride pigment (b) and pearlescent pigment (a), aluminum pigment (c) and / or white pigment (d)

consist. 2. aluminum metal effect paint according to claim 1, which additionally contains waxes. 3. Aluminum metal effect paint according to claim 1 or 2 with modified polyesters as binders. 4. Aluminum metal effect paint according to one of claims 1 to 3 with melamine resins as binders. 5. aluminum metal effect paint according to one of claims 1 to 4 with epoxy resins as binders. 6. Use of the aluminum metal effect paints according to one of claims 1 to 5 for the packaging painting. 7. packaging with a coating, in particular, Exterior paint, made of aluminum effect paint according to one of claims 1 to 5.   8. Use of pigments or pigment mixtures, which essentially consist of

• A) white pearlescent pigment (a) and aluminum pigment (c),
• B) white pearlescent pigment (a), aluminum pigment (c) and white pigment (d),
• C) bismuth oxychloride pigment (b),
• D) bismuth oxychloride pigment (b) and pearlescent pigment (a), aluminum pigment (c) and / or white pigment (d)

exist for the production of surfaces, which gives the visual impression of aluminum metal awaken. 9. Process for the production of surfaces, which the visual impression of aluminum metal awaken by applying one Aluminum metal effect paint on a support and Hardening of the resulting paint layer, thereby characterized in that one Aluminum metal effect paint according to one of the claims 1 to 5 used. 10. The method according to claim 9, characterized in that the carrier is packaging. 11. Pigment mixture, which consists essentially of

• a) white pearlescent pigment and / or
• b) bismuth oxychloride pigment and
• c) aluminum pigment

consists. 12. Pigment mixture, which consists essentially of

• a) white pearlescent pigment and
• b) bismuth oxychloride pigment

consists.   13. Pigment mixture according to claim 11 or 12, which additionally

• d) white pigment

contains. 14. Pigment mixture according to one of claims 11 to 13, containing, based on the pigment mixture,

• a) 0 to 90% by weight of pearlescent pigment,
• b) 0 to 90% by weight bismuth oxychloride pigment,
• c) 0 to 80 wt .-% aluminum pigment and
• d) 0 to 80% by weight of white pigment,

with the proviso that

• (i) the weight percentages always add up to 100% by weight,
• (ii) component a) must be present in the pigment mixture if component b) is not contained therein, and vice versa and
• (iii) component c) must be present in the pigment mixture if component b) is not contained therein.