DE202015002400U1 - silicate coating - Google Patents

Abstract

A product consisting of: an alumina layer having a composition that is free of silicates; and a silicate glass layer supported directly by the alumina layer and having an EDX composition of the silicate glass layer formed of silicone, oxygen, sodium, optionally lithium and optionally boron; the EDX composition of the silicate glass layer is free of aluminum.

Description

CROSS-REFERENCE TO ASSOCIATED APPLICATIONS

This disclosure claims priority to US provisional Patent Application No. 62 / 047,280, filed Sep. 8, 2014, the disclosure of which is fully incorporated herein by reference.

SCOPE OF THE INVENTION

The invention contained herein is directed to inorganic protective layers for aluminum and aluminum oxides.

BACKGROUNDS

The electrochemical formation of oxide layers on aluminum is a well-known and widely used industrial process for the production of protective and / or decorative coatings on aluminum and / or aluminum alloys. Electrolytically produced aluminum oxide layers protect the base metal from corrosion and weathering and increase the surface hardness and wear resistance of aluminum parts.

There are many different methods of anodization. For example, aluminum materials can be anodized in electrolytes such as sulfuric acid, chromic acid, phosphoric acid and oxalic acid using AC or DC current and a bath temperature of 10-25 ° C. Thickness and / or hardness of the anodized aluminum oxide layer may vary depending on the variation in this treatment.

The porosity of the anodized layer is favorable for the adhesion of organic coatings, but also has a major disadvantage, namely the lack of protection against corrosive media. For this reason, and to provide maximum corrosion stability, anodized aluminum layers are often sealed in a subsequent process step. In sealing, a heat seal and / or cold seal process, the alumina is hydrated and transformed from its amorphous anhydrous constitution to a boehmite structure. This transformation is accompanied by volumetric expansion or swelling of the oxide, which in turn is responsible for the sealing of the porous structure. The heat sealing of the anodizing layer is usually done in hot water or steam, whereas the cold sealing process takes place at temperatures near 30 ° C, in the presence of nickel fluoride. The seal improves protection against corrosion and weathering of the anodized parts in a pH range of 5-8.

Unfortunately, sealed anodized aluminum surfaces still have poor corrosion protection and stability below pH 4 and / or above pH 9. Additional seals or coatings have been tested, but optimized coatings with high and low pH stability are needed as well as accelerated corrosion, wear and fogging tests.

SUMMARY

Herein, a layered product containing an alumina layer having a silicate-free composition will be described; and a silicate glass layer supported directly by the alumina layer and having an EDX composition of the silicate glass layer consisting of silicone, oxygen, sodium, optionally lithium, and optionally boron; the EDX composition of the silicate glass layer is free of aluminum.

BRIEF DESCRIPTION OF THE FIGURES

For a better understanding of the disclosure, the following detailed descriptions and accompanying drawings should be considered:

Figure 12 is a graph of the average atomic percentage of silicone and aluminum as a function of the distance from the surface of a comparative product as calculated by EDX;

Figure 12 is a graph of the average atomic percentage of silicone and aluminum as a function of the distance from the surface of a product described herein, as calculated by EDX;

is a comparison between the atomic percentages of silicone in the alumina layer of a comparative layer sample ( ) and a product described herein ( );

is a plot of ion content as a function of distance, as determined by TOF-SIMS for a comparable product where surface milling has begun (T = 0);

Figure 12 is a graph of ion content as a function of distance as determined by TOF-SIMS for a sample described herein where surface milling has begun (T = 0);

Fig. 10 is a photograph of a comparable product (sample prior art) (below) and a sample (above) described herein after a 24 hour CLASS test;

is a photograph of a partially coated sample after being heated at 280 ° C for 15 minutes, the photograph (left) showing burn cracks and / or glaze cracks of an uncoated sealed anodized aluminum layer and (right) the undamaged, coated area.

Although certain embodiments are explained in the drawings, with the understanding that the disclosure is intended to be illustrative, these embodiments are not intended to limit the invention described and explained herein.

DETAILED DESCRIPTION

The present disclosure is concerned with metal products that have excellent durability and ease of preparation. In general, a product comprises a metal or metal alloy substrate, an oxide layer on the surface of the metal or metal alloy substrate, and a glass layer on the oxide layer, a silicate or borosilicate glass. The product according to this invention can be used for indoor and outdoor applications such as architectural fittings, automotive parts, aerospace components, marine components, bicycle components, motorcycle parts, heavy duty parts (including trucks, trains and rails), military components, Mirrors, components of street art (lanterns and street signs), furniture, appliances (refrigerators, washing machines, dryers, dishwashers, stoves, table appliances (mixers, hand blenders, toasters, rice cookers)), components for solar energy (reflectors and collectors), consumer goods and similar items (Mobile phones and computer parts), heat exchange, medical instruments and tools and / or components of oil and gas production (cooling lines); the substrate is generally considered a fixture or part and the oxide layer and silicate glass coat the fixture or part. Architectural fixtures and parts include material for or selected items of window frames, window coverings, doors, panels, mirrors, reflectors, lamp housings, hinges, handles, furniture parts including table or chair legs, seats or surfaces, clamps, tracks, railings and / or hardware , Automotive parts include parts of the body and / or wheels; including, for example, roof trusses / linings, window coverings, garbage killers, step / side railings, door trim, lamp shades, door handles, exhaust manifolds, reflectors, fuel tank cap, spoilers, pillar trims, scratch resistant door handle panels, antennas, hallmarks / logos, window screens, speaker panels, hubcaps, wheel rims, Wheel nuts, engine parts (pistons, guide blocks, axles, cams, pulleys, housings and covers) and / or exhaust parts (exhaust pipe / exhaust pipes, mufflers, converter covers, clamps, brackets and tailpipes). Aerospace parts include, for example, engine covers, panels, gyros, propellers, wings, flaps, elevators, and fairings. Parts of shipping include, for example, hull, mast, outrigger, grabber, winch, tiller, saling, handrail, tensioners, stanchions, hatches, and / or trailers. The bicycle parts include, for example, frames, stands, tubes, handles, rims, hand lever, gears and / or hubs. The motorcycle parts include, for example, wheels, hanger pipes, swing arms, engine parts, exhaust parts and trim.

Described herein is a layered product containing an alumina layer having a composition that is free of silicates, preferably with an EDX composition of the alumina layer that is free of silicone, boron, and / or nickel; and a silicate glass layer supported directly by the alumina layer and having an EDX composition of the silicate glass layer consisting of silicone, oxygen, sodium, optionally lithium, and optionally boron; the EDX composition of the silicate glass layer is free of aluminum. The silicate glass layer has a composition comprising about 55 wt.% To about 98 wt.% SiO ₂ , 0 wt.% To about 6.7 wt.% B ₂ O ₃ and about 2.3 wt.% To about 36 wt. % M ₂ O, wherein M is selected from the group consisting of lithium, sodium, potassium and a mixture thereof; wherein M is preferably a mixture of Li and Na, for example, with a ratio of Li: Na of about 1:10 to 10: 1; the Silicate glass layer contains less than 0.01 wt.% Aluminum, preferably less than 0.001 wt.% Aluminum. The silicate glass layer preferably has a TOF-SIMS composition consisting of silicone, oxygen, sodium, optionally lithium, and optionally boron; the TOF-SIM data of the silicate glass layer may have a trace of aluminum. The silicate glass layer may have a thickness between 50 nm and about 3000 nm, about 50 nm to about 2000 nm, about 50 nm to about 1500 nm, about 100 nm to about 1500 nm, about 250 nm to about 1500 nm, or about 500 nm to about 1000 nm.

The aluminum oxide layer contained herein is preferably free of silicates. That is, the alumina layer does not include glass-forming silicone oxides (such as SiO ₂ ), aluminosilicates, borosilicates, or mixtures thereof. In one case, the alumina layer has an EDX composition consisting of aluminum, oxygen, sulfur, and optionally a dye; and / or a TOF-SIMS composition consisting of aluminum, oxygen, sulfur and an optional dye. Preferably, the TOF-SIM composition of the aluminum oxide layer is free of silicone.

In one case, the alumina layer is a sealed alumina layer, or a PVD alumina layer (or hydrogenated PVD alumina layer). In another case, the layered product includes an aluminum surface; the alumina layer is bonded directly to the aluminum surface. Preferably, the layered product includes a substrate bearing the alumina layer selected from the group of aluminum, an aluminum alloy, and stainless steel.

Preferably, the layered product is free of aluminosilicate or silicate / alumina diffusion. More preferably, the layered product undergoes a 2-minute "pH 14 test" and a "24-hour CASS test."

Also included is a coated product that includes an aluminum surface bonded directly to a barrier layer. This barrier layer is directly connected to an aluminum oxide layer, which is directly connected to a silicate glass layer. Herein, "directly connected" means and means that the respective layers are chemically and / or physically connected without interlayer. This lack of an intermediate layer can be determined by spectroscopic and / or microscopic methods, for example energy dispersive X-ray spectroscopy (EDX), time-of-flight secondary ion mass spectrometry (TOF-SIMS) and / or scanning electron microscopy (SEM). Furthermore, a corrosion resistant coating is included that includes an alumina layer bonded to a substrate where the alumina layer may have a composition that includes, for example, about 70 wt.% To about 90 wt.% Al ₂ O ₃ , about 2.5 wt.% to about 7.5 wt.% H ₂ O and about 10 wt.% to about 20 wt.% SO ₃ . The corrosion resistant coating may include a borosilicate glass bonded to the alumina layer, wherein the borosilicate glass has a composition including SiO ₂ , B ₂ O ₃ and M ₂ O. M ₂ O is an alkali metal oxide wherein M is selected from the group consisting of Li, Na, K and a mixture thereof (e.g., Na ₂ O, Li ₂ O, LiNaO, K ₂ O). The components of borosilicate glass (SiO ₂ , B ₂ O ₃ and M ₂ O) are not separated, but a part thereof and preferably distributed homogeneously throughout the glass. The silicate glass layer and the composition of the alumina layer are described based on recognizable components (SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ ) in the layers, but consist of or comprise homogeneous compositions.

The composition of the silicate glass layer, based on the materials used to prepare the layer, may be about 55 wt.% To about 98 wt.% SiO ₂ , 0 wt.% To about 6.7 wt.% B ₂ O ₃ and from about 2.3 wt% to about 36 wt% M ₂ O. M is selected from the group of lithium, sodium, potassium, and a mixture thereof, and this choice can significantly affect the weight percent of the component parts. For example, in a composition in which the molar ratio of the components is kept high, the variation of M ₂ O from one hundred percent lithium, with an atomic mass of 6,941, to one hundred percent potassium, with an atomic mass of 39,098, causes a tenfold change in the percent weight. A preferred description of the composition of the silicate glass layer is based on the molar ratios of the components, but such descriptions are not common. Preferably, the molar ratios of the components (in terms of percentages) are about 67% to about 81% SiO ₂ , 0% to about 7% B ₂ O _3, and about 17% to about 28% M ₂ O. Alternatively, the mole ratios may be about 75%. to about 80% SiO ₂ and about 20% to about 25% M ₂ O; or from about 67% to about 76% SiO ₂ , from about 3% to about 5% B ₂ O _3, and from about 19% to about 30% M ₂ O.

The silicate glass layer may have an "EDX composition" corresponding to the composition of the silicate glass layer determined by EDX spectroscopy (see ). Preferably, the EDX composition of the silicate glass layer includes silicone, oxygen and sodium. More preferably, the EDX composition of the silicate glass layer is comprised of silicone, oxygen, and constituents the group of sodium, lithium, potassium, boron and mixtures thereof. Under various circumstances, the EDX composition of the silicate glass layer may consist of silicone, oxygen, sodium and boron; Silicone, oxygen, lithium and boron; Silicone, oxygen, sodium and lithium; Silicone, oxygen, sodium, lithium and boron; or silicone, oxygen, sodium, lithium, potassium and boron. In examples where the silicate glass composition (as determined by EDX or other methods) includes boron, the silicate glass is also referred to as borosilicate glass. The EDX composition of the silicate glass layer can be further described as a composition of silicone, oxygen, sodium, optionally lithium, and optionally boron. In certain circumstances, the silicate glass layer may be described as a composition of silicone, oxygen, optionally boron, sodium, and optionally lithium, but may Contain traces of potassium, since the materials used for the production of silicate glass layer may have slight impurities. In particular, the silicate glass layer may contain hydrogen, but hydrogen can not be detected by EDX spectroscopy. Preferably, the EDX composition of the silicate glass layer does not contain aluminum.

The silicate glass layer may have a "TOF-SIMS composition" corresponding to the composition of the silicate glass layer determined by TOF-SIMS (see ). Preferably, the TOF-SIM composition of the silicate glass layer includes silicone, oxygen and sodium. More preferably, the TOF-SIM composition of the silicate glass layer consists of silicone, oxygen and elements consisting of the group of sodium, lithium, potassium, boron and a mixture thereof. In particular, the silicate glass layer may contain hydrogen, but it can not be detected due to experimental difficulties and deviations in sample preparation. In addition, and because of the extremely high sensitivity of TOF-SIMS, the TOF-SIM composition of the silicate glass layer may contain traces of aluminum. Preferably, the silicate glass layer contains less than 0.1 wt% aluminum, preferably less than 0.01 wt% aluminum, more preferably even less than 0.001 wt% aluminum.

When the silicate glass layer contains sodium and lithium, the silicate glass layer has a Na: Li atomic ratio, which is preferably about 1: 9 to about 9: 1. Most preferably, the Na: Li atomic ratio is about 1: 5 to about 5: 1; preferably about 1: 2.5 to about 2.5: 1.

When the silicate glass layer is a borosilicate glass layer, the silicate glass layer includes boron, and the silicate glass layer has an Si / B atomic ratio of preferably about 10: 1 to about 200: 1. More preferably, the Si / B ratio is about 10: 1 to about 100: 1; and more preferably about 25: 1 to about 100: 1.

The silicate glass layer may have a thickness of about 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1500 nm, 2000 nm, 2500 nm or 3000 nm. Alternatively, the thickness of the silicate glass layer can range from about 50 nm to about 3000 nm, about 50 nm to about 2000 nm, about 50 nm to about 1500 nm, about 100 nm to about 1500 nm, about 250 nm to about 1500 nm, or about 500 nm to about 1000 nm.

In another example, the silicate glass layer includes a mixture of alkali metals selected from a mixture of sodium and potassium; Sodium, lithium and potassium; and lithium and potassium. In this example, the silicate glass layer includes a mixture of alkali metals wherein an alkali metal is potassium. Preferably, the silicate glass layer includes a non-homogeneous distribution of potassium. For example, wherein the silicate glass layer contains a high potassium region near the surface (separate from the aluminum oxide layer) as compared to a lower concentration of potassium in a region of the silicate glass adjacent to the substrate. The silicate glass can have a variety of ranges as differentiated from the tread depth of the potassium concentration.

Preferably, the concentration of silicone in the silicate glass layer is consistent throughout the layer. The consistency of the composition can be determined by the silicone concentration in the EDX composition of the silicate glass layer, preferably the silicone concentration varies by less than 5%, 4%, 3%, 2%, or 1% throughout the silicone glass layer. In addition, the oxygen concentration in the silicate glass layer is preferably consistent throughout the layer. The oxygen concentration in the EDX composition of the silicate glass layer varies by less than 5%, 4%, 3%, 2%, or 1% in the total silicate glass layer.

The silicate glass layer is preferably a dense, impermeable layer. More preferably, the silicate glass layer is non-porous. And more preferably, the silicate glass layer is transparent, informally solid.

As described above, the alumina layer may be about 70 wt.% To about 90 wt.% Al ₂ O ₃ , about 2.5 wt.% To about 7.5 wt.% H ₂ O, and about 10 wt.% To about 20 wt.% SO ₃ included; about 75 wt.% to about 85 wt.% Al ₂ O ₃ , about 3.5 wt.% to about 5.5 wt.% H ₂ O and about 12.5 wt.% to about 17.5 wt.% SO ₃ ; or about 80-81 wt.% Al ₂ O ₃ , about 5-6 wt.% H ₂ O and 14-15 wt.% SO ₃ . In alternative examples, the alumina layer may be free of SO ₃ . In a particularly preferred example, the alumina layer has an EDX composition consisting of aluminum, oxygen, sulfur and an optional dye. More preferably, the EDX composition of the aluminum oxide layer is free of nickel, the EDX composition of the aluminum oxide layer is free of silicone and nickel, and / or the EDX composition of the aluminum oxide layer is free of silicone, boron, and nickel.

Preferably, the composition of the alumina layer is consistent throughout the layer. The consistency of the composition can be determined by the aluminum concentration in the EDX composition of the alumina layer, preferably the aluminum concentration varies by less than 5%, 4%, 3%, 2% or 1% in the total alumina layer. The consistency of the composition may also be determined by the oxygen concentration in the EDX composition of the alumina layer, preferably the oxygen concentration varies less than 5%, 4%, 3%, 2% or 1% in the total alumina layer. In examples where a dye is added to the alumina layer in the preparation, the composition may vary in layer depth due to the location of the dye in the alumina pores.

The EDX composition of the alumina layer may include, or preferably consists of, 31-36% aluminum, 60-70% oxygen, and 2-5% sulfur. more preferably 31-35% aluminum, 63-67% oxygen and 3-4% sulfur and more preferably, 32-34% aluminum, 64-66% oxygen and 3-3.5% sulfur. As described above, the hydrogen concentrations in EDX spectroscopy are undetectable and therefore not part of the EDX composition. In addition, the EDX composition of the alumina layer may include an aluminum: oxygen ratio of 1: 2.

The TOF-SIM composition of the alumina layer includes aluminum and oxygen. In one example, the TOF-SIM composition includes the alumina layer, or preferably consists of aluminum, oxygen, sulfur, and an optional dye. More preferably, the TOF-SIM composition of the aluminum oxide layer is free of silicone, or free of silicone and boron (see ). In some examples, the TOF-SIM composition of the alumina layer includes sodium and / or lithium, but preferably it is free from, or mostly free from, potassium. Experimental circumstances make it difficult to detect the observation of one or more atoms in the TOF-SIM analysis - for example, the O + mass / ion was rarely observed at 16 amu, but recognizable as the Cs ion pair, CsO +, as a result of Cs ion milling.

The alumina layer may have a thickness of less than about 50 microns, 40 microns, 30 microns, 25 microns, 20 microns, 10 microns, 5 microns, 4 microns, 3 microns, 2 microns, 1 microns, or 500 nm. Preferably, the thickness of the alumina layer is in a range of about 1 to about 30 microns, about 2 to about 25 microns, about 3 to about 20 microns, or about 5 to about 25 microns. In one particular example, the alumina layer has a thickness of less than about 10 micrometers and the borosilicate glass layer has a thickness of less than 1 micrometer.

The alumina layer may have a boehmite / bayerite area without departing from the ranges described above. The boehmite / bayerite range includes a hydrated alumina, that is, an alumina having a higher proportion of hydroxyl groups than a dehydrated Al ₂ O ₃ . For example, the boehmite / bayerite region includes AlO (OH) and / or Al (OH) ₃ groups. In boehmite / bayerite examples, the boehmite / bayerite region is directly bonded to the silicate glass layer. In one example, the boehmite / bayerite region is within the alumina layer, with a higher level of hydroxyl groups, and is positioned between a region having a lower level of hydroxyl groups and the silicate glass layer. In another example, the boehmite / bayerite region extends over the entire alumina layer. The boehmite / bayerite area can be displayed in graphical representation of the TOF-SIMS of aluminum values over time (depth) (see ). Without being theory-critical, the variation in the aluminum value at or near the silicate glass layer may cause increased brittleness of the boehmite / bayerite region as compared to most of the alumina layer. This variation, as in between milling times of about 1300 and 2000, is an indication of the boehmite / bayerite area.

As described above, this composition may include a barrier layer bonded directly to the aluminum oxide layer. Preferably, the barrier layer has a TOF-SIM composition, which includes aluminum and oxygen. In some examples, the TOF-SIM composition of the barrier layer further includes sodium and / or lithium. In other examples, the TOF-SIM composition of the barrier layer may contain traces of silicone. Brittleness of the barrier results in an abrupt increase in the number in the TOF-SIM analysis.

Preferably, the compositions include an aluminum surface supported by a substrate. The substrate may be composed of, for example, aluminum, an aluminum alloy or stainless steel. The aluminum alloy can be selected from a series of 1000 series alloys, a 2000 series alloy, a 3000 series alloy, a 4000 series alloy, a 5000 series alloy, a 6000 series alloy, a 7000 series alloy and an alloy of the 8000 series. In a preferred example, the aluminum alloy is a 6000 series alloy; in another preferred example, the aluminum alloy is a 3000 series alloy; in another example, the aluminum alloy is a 1000 series alloy. The aluminum or aluminum alloy may be cast, pressed, hot rolled, cold rolled, annealed or tempered. In a preferred example, the aluminum or aluminum alloy is extruded. In another example, the aluminum or aluminum alloy is rolled. In another example, the cast, extruded or rolled aluminum or aluminum alloy is cured. In other examples, the substrate may be, for example, stainless steel, ceramic or plastic.

An important feature is its exceptional protection against corrosion and / or weathering, by the silicate glass coating described herein. In general, the protection against corrosion or weathering is determined using the results of the samples in the following test procedures. In doing so, samples are graded on a pass / fail scale; typically, the existence of a particular test is indicated by the absence of any visual change at the conclusion of the test; failure by a particular test is indicated by significant corrosion or weathering of the sample. Some tests offer lower double-digit results; under these circumstances, samples were additionally scored on a "- / 0 / +" scale: where "-" corresponds to a fall-out, "0" corresponds to a small change in appearance (eg, slight discoloration, staining or nebulization less than 10) % of the coated surface) and "+" corresponds to no change in appearance. Examples that show no visual change in appearance (value of "+") are considered excellent in the test.

First of all, the coating described herein provides the coated materials with protection from acidic environments. That is, the coated product exists and / or exceeds a "pH 1 test". The "pH 1 test" consists of a 10 minute immersion in an aqueous 0.1M HCl solution at ambient temperature (20-25 ° C).

In addition, the coating described herein provides the coated material with protection from normal environments. That is, the coated product surpasses a "pH 13.5 test". The "pH 13.5 test" is performed at 25-30 ° C by (a) immersing in pH 1 solution for 10 minutes; (b) rinse with water and dry; (c) cure at an elevated temperature of 40 ° C for 1 hour, followed by cooling (d) for 10 minutes in pH 13.5 solution, (e) rinse with water and dry , This test is commonly known as standard TL 182 (Volkswagen AG).

On the other hand, the coated product will pass or surpass a 2-minute "pH 14 test", preferably a 10-minute "pH 14 test", or more preferably a 30-minute "pH 14 test". The "pH 14 test" is performed by immersing the sample in a 1 M aqueous NaOH solution at 70 ° C (pH 14). The sample is kept in the liquor for at least 2 minutes, then removed, rinsed with water and dried. A typical defect in the pH 14 test is a coating or peeling off of the coating. Similar For example, samples were evaluated on a pass / fail basis with samples that had failed or covered, and samples that had maintained their integrity. In a few samples, a slight haze (nebulization) was observed after completion of the test; these samples passed the test. Preferably, samples have no change (no fogging, no corrosion, no color change) to the visual appearance as a result of the pH 14 test; these samples have "surpassed" the test under the test conditions.

In another example, the coating described herein provides the coated materials with protection from a copper chloride acetic acid spray test (CASS) (see ). Preferably, the coated product is a "24-hour CASS test", a "48-hour CASS test", a "72-hour CASS test" and / or a "120-hour CASS test". The CASS test is an industry standard ASTM 6368-09 , A typical error in the CASS test is a needle-like corrosion. Accordingly, samples are evaluated on a pass / fail basis whereby samples with needle-like corrosion fail and samples that maintain their integrity exist. In a few samples slight changes in the visual appearance were observed; these samples passed the test. Preferably, samples after the CASS test show no change in visual appearance; these samples have "surpassed" the test under the test conditions. In addition, samples preferably have no change in visual appearance as a result of an extended CASS test (48 hours).

In yet another example, the coated product described herein passes a "fogging test." In the nebulisation test, the sample is exposed for 72 hours to nitric acid vapors at a humidity of 95-100%, at about 38 °.

Another overload attempt is an "abrasion test". Here, the abrasion test comprises 20 grinding cycles (40 lengths) with steel wool grade 1 (medium, with a fiber width of 0.06 mm) and a force of 200 g / cm ² . Further abrasion tests can be carried out, for. As an "Amtec Kistler Car Was Test" and / or a "Tabertest".

Further overload tests include a "Heat Resistance Test" (120 hours at 200 ° C), a neutral salt spray test ( ASTM B117 ; 1,000 hours) and a "moisture resistance test" (300 hours). Preferably, the coated product described herein will pass these tests, one or all.

Preferably, the coated product described herein is a "pH 1 test"; if there is a "pH 13.5 test", pass a 2-minute "pH 14 test" (preferably a 10-minute "pH 14 test", more preferably a 30-minute "pH 14 test"); and passes a "24-hour CASS test" (preferably a "48-hour Cass test", a "72-hour CASS test", or a "240-hour CASS test").

In another application, the coated product includes a substrate bearing an alumina layer bonded directly to the silicate glass layer. Here, the coated product may be free of barrier layers, that is, the alumina layer may be bonded directly to the substrate. An example of an alumina layer bonded directly to the substrate is Physical Vapor Deposited (PVD) alumina supported on a substrate where a PVD alumina layer was formed directly on the receiving substrate. The composition of the alumina layer (the PVD alumina layer) may be sulfur free. Preferably, the composition of the alumina layer may be made of aluminum and oxygen, and more preferably in a ratio of about 2: 3 (Al ₂ O ₃ ). In another example, the alumina layer may include aluminum, oxygen, and hydrogen. Further, the alumina layer (the PVD alumina layer) may contain or consist of a bayerite / boehmite region in addition to the silicate clad layer.

In addition, a method for preparing the above-described surface coatings or coated products is included. In general, the method involves coating alumina with an aqueous silicate solution and then polymerizing and curing a silicate glass molded from the silicate solution. An important feature of the process, referred to in the above description of the surface coating, is the avoidance of silicate entering the alumina and the aluminum dissolving and occurring in the silicate glass. Control of the resulting compositions by the process described herein results in a coating or coated product having unexpected and exceptional resistance to corrosion and damage.

The method may comprise at least the formation of an aluminum oxide layer which is coated with an aqueous silicate solution and then a silicate glass is polymerized and cured on the aluminum oxide layer. For a full understanding, the method is described herein with additional, preferred steps that apply to the formation of the above-described coatings or coated products.

Described herein is a method of preparing a surface coating, which may include forming a coated alumina layer by applying an aqueous silicate solution on an alumina layer, having a thickness of about 1 μm to about 25 μm, the alumina layer being a sealed, anodized aluminum layer or a hydrated PVD aluminum layer and the aqueous silicate solution has a pH of about 11 to about 13, a composition having a ratio of SiO ₂ to M ₂ O of about 3.5 to about 2, wherein M is selected from Li, Na K and a mixture thereof and a ratio of SiO ₂ to B ₂ O ₃ of about 10: 1 to about 200: 1; and thereafter polymerizing and curing a silicate glass on the sealed, anodized aluminum layer by (A) Heating the coated anodized aluminum layer to a temperature of from about 200 ° C to about 500 ° C; or (B) exposing the coated, anodized aluminum layer to an infrared source. The method may further include providing an aluminum surface; Anodizing the aluminum surface to provide an unsealed, anodized aluminum layer and then heat sealing the unsealed aluminum oxide layer to obtain a sealed, anodized aluminum layer. The heat seal may have a heat seal duration of less than 6 min / micron and at least 5 min / micron, 4 min / micron, 3 min / micron, 2 min / micron, 1 min / micron, 30 sec / micron or 10 sec / micron include; the formation of the sealed, anodized aluminum layer from the unsealed anodized aluminum layer consists of the heat sealing process.

In addition, the process may include a period between the completion of the heat seal process and the formation of the coated anodized aluminum layer, of less than 60, 45, 40, 35, 30, 25, 20, 15, 10, or 5 minutes. Preferably, the duration is less than 5 minutes, or not more than the time necessary to remove the sample from a heat seal bath or apparatus, cool to about room temperature, and then immerse in the aqueous silicate solution (often less than 1 minute in practice). In another example, the sealed, anodized aluminum layer may be kept in a moist environment, water, or water-coated; before the coated, anodized aluminum layer is formed by using the aqueous silicate solution.

Also included is a multi-step process that includes the provision of an alumina layer in a first step. The alumina layer may be formed by anodizing aluminum or an aluminum alloy, or depositing an alumina layer, such as by physical vapor deposition (PVD). Although the structure of the alumina layer is chemically similar, it differs by the different methods of production. Anodization provides a known porous layer, whereas PVD typically produces a dense, non-porous layer. Prior to coating with the silicate solution, the alumina layer is preferably non-porous and / or contains a high proportion of hydroxyl groups on an outer surface.

The alumina layer may be formed (by anodization or PVD) on aluminum, an aluminum alloy or other surface. In examples where the aluminum oxide layer is formed on aluminum or an aluminum alloy, the surface preferably has a <110> or a <112> orientation. In a preferred example, the surface of aluminum or aluminum alloy has a <110> orientation. In particular, the surface of aluminum or aluminum alloy is not monocrystalline and the orientation of the surface may include other crystal orientations. Herein may be an aluminum or an aluminum alloy intended for <110> orientation. <100>, <111>, <211> and <311> orientations. Preferably, the aluminum or aluminum alloy having the <110> orientation contains at least 50% <110>; more preferably 75% <110>; and more preferably, the non-<110> orientations that individually occur at less than 20% of the surface orientation. In another example, the surface may have a <200> orientation. Preferably, the aluminum or aluminum alloy having the <200> orientation contains at least 75%, 80%, 85%, 90%, 95%, or about 100% <200> surface orientation.

The aluminum or aluminum alloy may have a coarse or fine grain size (as determined by the surface analysis). Preferably, the aluminum or aluminum alloy has a fine-grained size. For example, the aluminum or aluminum alloy may have an average grain size of less than 500 μm, 400 μm, 300 μm, 250 μm, 200 μm, 150 μm or 100 μm. In one example, the aluminum or aluminum alloy has a grain size of about 250 μm, 200 μm, 150 μm, 100 μm, 75 μm, 50 μm or 25 μm.

In a preferred example, the alumina layer is exposed to water at a temperature of at least 85 ° C. The method may include forming a sealed anodized aluminum layer by a heat seal method. The heat seal method comprises exposing the anodized aluminum, preferably a hard anodized aluminum layer, to water at a temperature of at least 85 ° C, 90 ° C, 95 ° C, 98 ° C, 99 ° C, 100 ° C or 101 ° C. In one example, hard anodized aluminum may be heat sealed in boiling or near boiling water, in another example, the hard anodized aluminum may be steam sealed. Preferably, anodized aluminum is sealed in boiling or near-boiling water. The water is preferably free of silicates and transition metals (such as nickel) and / or sealing additives. When heat sealing the hard anodized aluminum layer, the hard anodized aluminum may be for at least 5 min / micron, 4 min / micron, 3 min / micron, 2 min / micron, 1 min / micron, 30 sec / micron, or 10 sec / micron of water get abandoned. The Alternatively, the process may comprise exposure to a PVD aluminum layer of water at a temperature of at least 85 ° C, 90 ° C, 95 ° C, 98 ° C, 99 ° C, 100 ° C or 101 ° C to form an aqueous PVD aluminum to obtain. In one example, the PVD aluminum layer may be exposed to boiling or near-boiling water, in another example, the PVD aluminum layer may be exposed to steam. Preferably, the PVD aluminum layer is exposed to boiling or near-boiling water, the water being free of silicates, transition metals and / or sealing additives. Alternatively, a high hydroxyl content aluminum oxide layer of PVD can be produced (PVD of a boehmite / bayerite layer). Preferably, the process includes forming aluminum hydroxides on the exposed surface of the alumina layer upon exposure of the material to water at a temperature of at least 85 ° C. Optionally, the process may include the formation of aluminum hydroxides within the alumina layer. More preferably, the method includes forming a boehmite / bayerite region in the alumina layer.

The alumina layer (the sealed anodized aluminum layer or the hydrated PVD aluminum layer) may have a thickness of about 1 μm to about 50 μm. The alumina layer may have a thickness of less than about 50 microns, 40 microns, 30 microns, 25 microns, 20 microns, 10 microns, 5 microns, 4 microns, 3 microns, 2 microns, 1 microns, or 500 nm. Preferably, the thickness of the aluminum layer is in the range of about 1 to about 30 microns, about 2 to about 25 microns, about 3 to about 20 microns, or about 5 to about 25 microns. In one example, the alumina layer has a thickness of less than 10 microns.

In one particular example, the alumina layer is a sealed, anodized aluminum layer having a composition free of silicates, preferably free of silicone and, more preferably, free of nickel. For example, the sealed anodized aluminum layer may have a composition comprising about 75 wt% to about 85 wt% Al ₂ O ₃ , about 3.5 wt% to about 5.5 wt% H ₂ O, and about 12.5 wt% to about 17.5 wt.% SO ₃ , or consists thereof. In another example, the alumina layer is an aqueous PVD aluminum layer having or consisting of a composition containing aluminum, oxygen, and hydrogen.

The method may include coating the alumina layer with an aqueous silicate solution; that is, a coated alumina layer wherein the alumina layer carries a coating / layer of an aqueous silicate solution. For example, the coated alumina layer may be a coated, anodized aluminum layer, or a coated PVD aluminum layer. In a preferred example, the method comprises applying an aqueous silicate solution to the sealed, anodized aluminum layer. Alternatively, the method may comprise applying the aqueous silicate solution to a hydrated PVD layer. Preferably, the aqueous silicate solution is maintained at a temperature below 30 ° C, 25 ° C or 20 ° C.

The coated alumina layer preferably contains or consists of the alumina layer (the sealed, anodized alumina layer) and a silicate solution layer. The silicate solution layer may have a thickness of about 0.1 μm to about 5 μm, about 0.5 μm to about 4 μm, or about 1 μm to about 3 μm.

The aqueous silicate solution has a pH of about 11 to about 13, about 11 to about 12, or about 11 to about 11.5. Preferably, the aqueous silicate solution has a composition having a ratio of SiO ₂ to M ₂ O of about 3.5 to about 2, about 3.5 to about 2.25, about 3.5 to about 2.5, about 3, 5 to about 2.75 or about 3.5 to about 3, wherein M is selected from Li, Na, K and a mixture thereof. More preferably, the aqueous silicate layer has a composition comprising a ratio of SiO ₂ to B ₂ O _{3 of} from about 10: 1 to about 200: 1.

In one example, the coating process may include immersing the alumina layer in the aqueous silicate solution and withdrawing the coated, anodized aluminum layer from the aqueous silicate solution. In another example, the coating process may include spray coating or roller coating the alumina layer with the aqueous silicate solution.

The coating process precludes the formation of aluminum silicates. More preferably, the method includes avoiding the formation of an aluminum silicate. In one example, avoiding the formation of aluminum silicate may include preventing the penetration of the aqueous silicate solution into the alumina layer. More preferably, avoiding the formation of the aluminum silicate involves dissolving aluminum from the alumina layer into the aqueous silicate solution. For example, the coating process prevents the diffusion of the silicate into the aluminum and / or the interdiffusion of the Silicate and aluminum, while offering a product that is free of aluminum silicates or interdiffusion of silicate / aluminum. Methods for avoiding the penetration of the aqueous silicate solution into the alumina layer may include sealing the pores in the alumina layer to reduce penetration of the silicate solution and thereby formation of interstitial Al / Si layers, formation of a non-porous alumina layer, and / or rapid Dry the aqueous silicate solution to reduce or eliminate the mobility of the silicone atoms. Methods of preventing the dissolution of aluminum from the alumina layer into the aqueous silicate solution may include incomplete hydration of the alumina layer, or reduction of the percentage of Al (OH) ₃ in the alumina layer, carrying out the coating process at a reduced temperature (cooling the aqueous silicate solution and / or or the alumina layer) and / or rapid drying of the aqueous silicate solution. In one example, the method may include preheating the coated anodized aluminum layer to a temperature of about 30 ° C to about 100 ° C immediately after the formation of the coated alumina layer. In another example, the method may include drying the coated, anodized aluminum layer immediately after the formation of the coated alumina layer. In another example, the method may include reducing the amount of water in the coated anodized aluminum layer by at least 25%, 50%, or 75% immediately after the formation of the coated alumina layer.

The method also preferably comprises rapid application of the aqueous silicate solution to the alumina layer after heat sealing (by exposing the alumina layer to hot water). For example, the method may include forming a coated, anodized aluminum layer by applying the aqueous silicate solution within 45, 40, 35, 30, 25, 20, 15, 10, or 5 minutes after completion of the heat seal process. That is, the method may include immersing the sealed, anodized aluminum layer in the aqueous silicate solution; or spray coating or roll coating the sealed, anodized aluminum layer with the aqueous silicate solution within 45, 40, 35, 30, 25, 20, 15, 10 or 5 minutes after completion of the heat seal process. In another example, the method may include forming a coating PVD aluminum layer by applying the aqueous silicate solution within 45, 40, 35, 30, 25, 20, 15, 10, or 5 minutes after removal from the water at a temperature of at least 85 ° C.

Alternatively, the method may include maintaining or maintaining the heat-sealed alumina layer in a relative humidity environment of at least 50%, 60%, 70%, 80%, 90%, or about 100% prior to coating the alumina layer with the aqueous silicate solution. For example, a sealed hard anodized aluminum layer may be maintained in an environment of relative humidity of at least 50%, 60%, 70%, 80%, 90%, or about 100%, for a duration greater than 45 minutes, 1 h, 2 h, 3 h, or 4 h, and then coated with an aqueous silicate solution. In another example, in the process, the alumina layer exposed to hot water may be held in water and then coated with an aqueous silicate solution. Preferably, the alumina layer is maintained in water at a temperature of less than 75 ° C, 65 ° C, 60 ° C, 55 ° C, 50 ° C, 45 ° C, 40 ° C, 35 ° C, 30 ° C, 25 ° C, or 20 ° C. For example, in the method, the sealed, anodized aluminum layer may be held or dipped in water and then the coated, anodized aluminum layer may be formed by applying the aqueous silicate solution.

The coated alumina layer contains an aqueous solution of an alkali metal silicate supported by the surface of an alumina. Without being limited by theory, the dried, coated alumina layer may contain sufficient water to allow solution of the alkali metal silicate from the alumina layer. That is, prior to polymerization and the curing step, the alkali metal silicate may be dissolved or removed from the surface of the alumina layer, for example by washing the surfaces in water or an alkali solution (0.01 M ^aq NaOH, or 0.1 M ^aq NaOH). ,

An important step in the preparation of the coated / corrosion protected product is the polymerization and curing of a silicate glass. The silicate glass may be formed from the heating and dehydration of an aqueous solution of an alkali metal silicate, from the surface of the alumina layer. Alternatively, the silicate glass may be formed by the infrared release of the aqueous solution of the alkali metal silicate on the surface of the alumina layer.

In one example, the heating of the coated aluminum oxide layer enables the removal of water from the coated dehydration polymerization of SiO ₄ groups and the curing of silicate glass. For example, the method may include polymerizing and curing a silicate glass by heating the coated anodized aluminum layer to a temperature of about 200 ° C to about 500 ° C. The polymerization and curing temperature may range from about 200 ° C to about 500 ° C, preferably, this temperature is from about 200 ° C to about 400 ° C, about 250 ° C to about 350 ° C, about 260 ° C to about 325 ° C, or about 260 ° C to about 300 ° C. More preferably, the polymerization and curing of the silicate glass comprises heating the surface of the substrate, ie the coated anodized aluminum layer, to a temperature of about 240 ° C to about 320 ° C, about 260 ° C to about 300 ° C, about 270 ° C to about 290 ° C, or about 280 ° C.

The polymerization and curing of the silicate glass involves the rapid heating and dehydration of the aqueous alkali metal silicate. Unexpectedly, the aluminum oxide layer is resistant to known cracking and / or cracking of the surface due to rapid heating and / or dehydration of the aluminum oxide layer (see ). The aluminum oxide layer would crack, rupture or dissolve, whereas the coated aluminum oxide layer could be heated to the polymerization and curing temperature at a rate of 1 ° C / s, 10 ° C / s, 25 ° C / s, 50 ° C / s, or 100 ° C / s; or a speed of at least 10 ° C / s, 25 ° C / s, 50 ° C / s, or 100 ° C / s. Visual recognition of cracks, cracks or solutions is already evident, but surface damage is more likely to be detected by failure of the test methods described herein (the "pH 1 test", the "pH 14 test", or the "CASS test"). , In a preferred example, the polymerization and curing of the silicate glass involves heating the silicate layer (solution / glass) but incomplete heating of the underlying substrate.

The heating and dehydration of the aqueous silicate solution on the surface of the alumina layer can be completed by, for example, direct heating in an oven, heating with lamps, a vacuum process, or a combination thereof. In a preferred example, the coated alumina layer is heated in an oven. In one example, the coated alumina layer is heated in a conventional oven. In another example, the coated alumina layer is heated in a convection oven which allows a faster and more uniform evaluation of the temperature of the coated alumina layer. In yet another example, the coated alumina layer is passed through a heating zone (in a continuous oven). More preferably, the coated alumina is heated to the polymerization and curing temperature at a rate of at least 20 ° C / s, heated for a duration of less than about 30 minutes, and then heated from the heat source to a temperature of less than 50 ° C , 40 ° C, or 30 ° C, preferably brought from the heat source to a temperature of about 20-25 ° C (normal room temperature). Preferably, the duration of direct heating is less than about 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, or 30 minutes. More preferably, the heating time is less than about 15 minutes.

In another example, the silicate glass may be formed by the infrared activation of the alkali metal silicate layer on the surface of the aluminum oxide layer. For example, the coated alumina layer may be polymerized and the silicate glass cured by exposing the coated, anodized aluminum layer to an infrared (IR) source. In one example, the coated alumina layer is exposed to an IR heat lamp (shortwave or mediumwave lamps). In another example, the coated alumina layer is transported through an IR region (on an assembly line). The IR transmission from the IR source can be from 1 to 3 μm (short-wave IR), from about 3 to about 5 μm (medium-wave IR, or medium IR), or from about 2 to about 4 μm (IR-B). , Preferably, the duration of irradiation with the IR source is less than about 15 seconds, 30 seconds, 45 seconds, 60 seconds, 90 seconds, 120 seconds, 3 minutes, 4 minutes, 5 minutes, or 10 minutes Time less than about 15 seconds, 30 seconds, 45 seconds, 60 seconds, 90 seconds or 120 seconds.

Surprisingly, the IR-cured silicate glass protects against known fractures and / or cracks in the surface. While aluminum oxide layers break, crack or peel off; For example, the coated alumina layer can be exposed to the IR source and the hardened silicate glass appears as a uniform, unbroken surface (see ). Although cracks, breaks or peelings can be detected visually quickly, damaged surfaces are more likely to be identified by failure of the test methods described herein (eg, the "pH 1 test", the "pH 14 test" and / or the "CASS" test). Test"). Here the products with the IR-hardened silicate glass pass the "pH 1 test", the "pH 14 test" and the "CASS test".

In one specific example, the method of preparing a surface coating may include forming a coated, anodized aluminum layer by dip coating, spray coating, or roll coating a sealed, anodized aluminum layer having a thickness of about 1 μm to about 25 μm with an aqueous silicate solution. The coated, anodized aluminum layer may consist of a sealed, anodized aluminum layer and a silicate solution layer, wherein the silicate solution layer has a thickness of about 1 μm to about 3 μm, and the composition of the sealed, anodized Aluminum layer about 75 wt.% To about 85 wt.% Al ₂ O ₃ , about 3.5 wt.% To about 5.5 wt.% H ₂ O and about 12.5 wt.% To about 17.5 wt.% SO ₃ and free of nickel and silicone is. The following method involves polymerizing and curing the coated anodized aluminum layer to form a nonporous silicate glass. Polymerization and curing involve heating the coated anodized aluminum layer to a temperature of about 225 ° C to about 300 ° C. The above-described properties in terms of thickness, composition and heating can be further refined by the corresponding general disclosures.

In another specific example, the process of heat sealing an anodized aluminum layer by exposing the anodized aluminum layer to water may be at a temperature of at least 85 ° C, 95 ° C or 100 ° C. The following method comprises either (A) forming a coated, anodized aluminum layer by dip coating, spray coating, or roll coating the sealed anodized aluminum layer with an aqueous silicate solution within 20, 15, 10, or 5 minutes after completion of the heat seal, or (B) Immersing a sealed, anodized aluminum layer in water, after the heat sealing process and then forming the coated, anodized aluminum layer by dip coating, spray coating or roll coating with the aqueous silicate solution. The sealed, anodized aluminum layer has a thickness of about 1 micron to about 25 microns, the coated, anodized aluminum layer consists of the sealed, anodized aluminum layer and a silicate solution layer having a thickness of about 1 micron to about 3 microns and the sealed, anodized aluminum layer has a composition containing from about 75 wt.% to about 85 wt.% Al ₂ O ₃ , from about 3.5 wt.% to about 5.5 wt.% H ₂ O and from about 12.5 wt.% to about 17.5 wt.% SO ₃ , and free from nickel and silicone.

Thereafter, the process comprises polymerizing and curing the coated anodized aluminum layer to form a nonporous silicate glass, polymerization and curing include heating the coated anodized aluminum layer to a temperature of from about 225 ° C to about 300 ° C. The above-described properties in terms of thickness, composition and heating can be refined by the corresponding general disclosures.

In another specific example, the method of preparing a surface coating may consist of forming a coated PVD aluminum layer by dip coating, spray coating, or roll coating a PVD aluminum layer having a thickness of about 1 μm to about 25 μm with an aqueous silicate solution. The coated PVD aluminum layer may consist of the PVD aluminum layer and a silicate solution layer, wherein the silicate solution layer has a thickness of about 1 μm to about 3 μm. The following method involves polymerizing and curing the coated PVD aluminum layer to form a nonporous silicate glass, polymerization and curing include heating the coated PVD aluminum layer to a temperature of about 225 ° C to about 300 ° C. The above-described properties in terms of thickness, composition and heating can be refined from the corresponding general disclosures.

EXAMPLES

By way of example, test samples are presented which are prepared as follows and represent the various embodiments of the present disclosure as well as the performance of experimental tests.

The aqueous silicate solution described herein may be an alkali borosilicate solution containing a mixture of sodium and lithium metal counterions. The alkali borosilicate solution can be prepared by combining concentrated, commercial, liquid sodium silicate and lithium silicate solutions. Then a borax solution (sodium tetraborate decahydrate (Na ₂ B ₄ O ₇ .10H ₂ O) in water) is added to this lithium sodium solution. The final borax concentration in the coating solution may be between 1-5% by weight. In one example, the aqueous silicate solution contains 13.0% SiO ₂ , 1.7% Na ₂ O, 1.2% Li ₂ O, 1.1% B ₂ O ₃ and 83.0% H ₂ O by weight and has a gravity of about 1.15. Before use, the solution was filtered through a 1.2 mm filter. The aqueous silicate solution has a gravity of 1.136 and was kept at 20 ° C.

The following general procedures were used for test samples:

Anodization: The test of the components was performed on test molds on vehicle trim produced by the extrusion and heat treatment of a 6061 series aluminum alloy. The test molds were about 100 mm by 500 mm and comprised a multi-layered cross-sectional profile. The Aluminum mold was degreased (alkaline), purified (nitric acid) and then anodized in a saltpetre bath at 19 ° C for 15 min, at 16 V and 1.5 A / dm ² . The anodized sample was then rinsed three times with DI water. This resulted in an unsealed, anodized aluminum layer on the aluminum mold.

Heat seal: after anodization and unless noted otherwise, test specimens were heat sealed at about 97 ° C by the standard industrial method. A test standard was set up with a heat seal of 2 minutes per micrometer anodization (20 minutes for a 10 micron thick anodized layer).

Coating: Test samples (heat sealed or not) were coated with aqueous silicate solution, by dip coating, spray coating, or roll coating, for a coated thickness of about 1 μm to about 5 μm. Preferably, the test samples were immersed in the aqueous silicate solution for five minutes. Unless otherwise noted, the aqueous silicate solution was the alkali borosilicate solution described above.

Polymerization and Curing: Coated test samples were exposed to elevated temperatures to polymerize and cure the silicate coatings. The temperatures can be reached in normal, convection or IR ovens. The cure times (time at the elevated temperature) varied from about 3 to 30 minutes. Heating for 30 minutes brought no added value.

Test samples were subjected to the following tests: a 24-hour CASS test, a 2-minute pH 14 test, a nebulization test, and an abrasion test. Table 1 contains data to prepare a summary of the reference samples: Sample number poetry Anodizing at shift time Layer type Curing time ¹ Ref. C1 None 0 ABS ² 3 min Jennings ³ C2 None 0 ABS ² 7 min Jennings ³ C3 None 0 ABS ² 15 minutes Jennings ³ C4 None 0 ABS ² 30 min Jennings ³ C5 800 seconds cold then 800 seconds hot 0 0.5 wt.% Sodium silicate 0 Lawlor ⁴ 1: duration at a hardening temperature of 280 ° C.
2: The above-described alkali borosilicate solution.
3: US Pat. 8,173,221
4: US Pat. 7,851,025

Table 2 contains data to prepare comparative samples that can be considered as annexes to the summary: Sample number poetry Anodizing at shift time Layer type Curing time ¹ Ref. C6 None 5 h ABS ² 15 minutes Jennings ³ C7 None 24 hours ABS ² 15 minutes Jennings ³ C8 800 seconds cold then 800 seconds hot 0 ABS ² 15 minutes Lawlor ⁴ 1: duration at a hardening temperature of 280 ° C.
2: The above-described alkali borosilicate solution.
3: US Pat. 8,173,221
4: US Pat. 7,851,025

Table 3 contains data for preparation of the samples contained herein, using the alkali borosilicate solution described above: sample Heat sealing ¹ Sealing layer duration ² Curing time ³ 1 0.5 0 15 2 2 0 15 3 6 0 15 4 2 5 ⁴ 15 5 2 24 ⁴ 15 6 2 5 ⁵ 15 7 2 24 ⁵ 15 8th 2 0 3 9 2 0 7 10 2 0 30 1: Duration of heat seal in minutes per micron of anodized film thickness.
2: The duration in hours between the heat seal and the coating with the alkali borosilicate solution.
3: Duration at a hardening temperature of 280 ° C.
4: Samples are kept in the air at room temperature for the time between the heat seal and the coating.
5: Samples are placed in water at room temperature for the time between the heat seal and the coating.

Table 4 contains the test results of all samples. Sample number 24-hour CASS 2 minutes pH 14 obscuring abrasion C1 F P (0) F P (0) C2 F P (+) F P (0) C3 F P (+) P (0) P (0) C4 F P (+) P (+) P (0) C5 F F F F C6 F P (0) P (0) P (0) C7 F P (0) P (0) P (0) C8 F P (+) F P (0) 1 P (+) P (+) P (+) P (+) 2 P (+) P (+) P (+) P (+) 3 P (0) P (0) P (+) P (+) 4 P (0) F P (0) P (0) 5 P (0) F P (0) P (0) 6 P (0) P (0) P (0) F 7 P (0) P (0) P (0) F 8th P (+) P (0) F P (0) 9 P (0) P (+) P (0) P (0) 10 P (+) P (+) P (+) P (+)

TOF-SIMS Test: Comparative Sample 3 (unsealed) and Sample 2 (sealed) were ion-milled and ingredient analysis was completed at the time of time-of-flight secondary ion mass spectrometry (TOF-SIMS). Milling distances were about 1 micron per cycle. Table 5 contains atomic percentages of silicone and aluminum (oxygen balanced): milling cycle Comparative sample C3 Sample 2 Si al Si al 1 29.4 0.9 30.0 1.4 2 28.6 0.1 29.3 0.1 3 28.5 0.1 29.3 0.2 4 28.3 0.0 3.2 29.3 5 28.7 0.2 0.0 34.0 6 1.4 31.7 0.0 33.8 7 1.3 32.9 0.0 34.2 8th 0.6 32.7 0.0 34.3 9 0.4 33.2 0.0 34.9 10 0.4 33.1 0.0 34.4 11 0.8 33.3 0.0 34.8 12 1.0 32.7 0.0 34.9 13 0.6 33.0 0.0 34.7 14 0.4 33.7 0.0 90 15 0.5 33.2 0.0 100 16 0.5 37.9 0.0 100 17 0.0 99.5 0.0 99.7 18 0.0 99.8 0.0 100

It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the origin of the present invention and without diminishing the desired benefits. It is therefore intended that such changes and modifications be covered by the appended disclosure.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 81732214 [0085, 0086]
• US 7851025 [0085, 0086]

Cited non-patent literature

• ASTM 6368-09 [0044]
• ASTM B117 [0047]

Claims (12)

A product consisting of: an alumina layer having a composition free of silicates; and a silicate glass layer supported directly by the alumina layer and having an EDX composition of the silicate glass layer formed of silicone, oxygen, sodium, optionally lithium and optionally boron; the EDX composition of the silicate glass layer is free of aluminum. The product of claim 1, wherein the alumina layer has an EDX composition that is free of silicone, boron, and / or nickel. The product of any one of the preceding claims, wherein the silicate glass layer has a composition comprising about 55 wt.% To about 98 wt.% SiO ₂ , 0 wt.% To about 6.7 wt.% B ₂ O ₃ and about 2.3 wt.% to about 36 wt.% M ₂ O, wherein M is selected from the group of lithium, sodium, potassium and a mixture thereof; preferably M is a mixture of Li and Na, for example with a Li: Na ratio of about 1:10 to 10: 1; wherein the silicate glass layer contains less than 0.1 wt% aluminum, preferably less than 0.01 wt% aluminum, more preferably less than 0.001 wt% aluminum. The product of any one of the preceding claims, wherein the silicate glass layer has a TOF-SIMS composition of silicone, oxygen, sodium, optionally lithium and optionally boron; wherein the TOF-SIM data of the silicate glass layer has a trace of aluminum. The product of any one of the preceding claims, wherein the silicate glass layer has a thickness in the range of about 50 nm to about 3000 nm, about 50 nm to about 2000 nm, about 50 nm to about 1500 nm, about 100 nm to about 1500 nm, about 250 nm to about 1500 nm, or about 500 nm to about 1000 nm. The product of any one of the preceding claims, wherein the alumina layer has an EDX composition of aluminum, oxygen, sulfur and an optional dye. The product of any one of the preceding claims, wherein the alumina layer has a TOF-SIM composition of aluminum, oxygen, sulfur and an optional dye; wherein the TOF-SIMS composition of the aluminum oxide layer is free of silicone. The product of any one of the preceding claims, wherein the alumina layer is a sealed alumina layer or a PVD alumina layer. The product of any one of the preceding claims, further comprising an aluminum surface; wherein the aluminum oxide layer is bonded directly to the aluminum surface. The product of any one of the preceding claims, further comprising a substrate containing the alumina layer selected from the group consisting of aluminum, an aluminum alloy, and stainless steel. The product of any one of the preceding claims, wherein the layered product is free of aluminum silicate or silicate / aluminum interdiffusion. The product of any one of the preceding claims, wherein the product is a 2-minute "pH 14 test" and a "24-hour CASS test".

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