DE10114468A1 - Corrosion-resistant laminate, process for its production and its use - Google Patents

Abstract

Laminate containing DOLLAR A A) a metallic layer, DOLLAR A B) a layer of a plasma polymer and DOLLAR A C) a film; DOLLAR A and a device (1) for its production, comprising DOLLAR A 1. a first pair of rollers (2) with a nip (2a), DOLLAR A 2. a second pair of rollers (3) with a nip (3a), DOLLAR A 3 a third roller pair (4) with a roller gap (4a), DOLLAR A 4. a feed roller (8) which is coupled to a roller of the roller pair (4) and forms the roller gap (4b) with it, DOLLAR A so that DOLLAR A 5. a layer A) (10) can be conveyed through the nips (2a), (3a) and (4a), DOLLAR A 6. a film C9 (9) is conveyed through the nip (4b) to the nip (4a) and DOLLAR A 7. the roller pairs form closed reaction spaces (6) and (7) together with wall elements, the reaction space (6) cleaning and / or building up an oxidic cover layer and the reaction space (7) forming the plasma polymer ( B) on the surface (10a).

Description

The present invention relates to a new corrosion-resistant laminate, which at least a layer which contains or consists of at least one metal and at least one Has layer of a plasma polymer. The present invention further relates to a new process for the production of the new corrosion-resistant laminate. Not least The present invention relates to the use of the new laminate for manufacture of molded parts, in particular of automobile body parts.

Laminates comprising a metal layer, a plasma polymer layer applied thereon and a Lacquer layer, made from, for example, conventional and known two-component Epoxy amine waterborne basecoats, one-component clearcoats, or cathodic separable electrodeposition paints, are from the dissertation by G. Grundmeier, "Interface chemical and corrosion analysis of Plasma polymer coatings on steel ", Technical Faculty of the University of Erlangen- Nuremberg, 1997, the patent specifications EP 0 533 606 B1, EP 0 619 847 B1 or EP 0 515 373 B2 or from the articles by Tinghao F. Wang et al., "Corrosion protection of cold rolled steel by low temperature plasma interface engineering ", in progress in organic coatings, Volume 28, pages 291 to 297, 1996, or by G. Grundmeier and M. Stratmann, "Plasma polymerization - a new and promising way for the corrosion protection of steel ", materials and Corrosion, Volume 49, pages 150 to 160, 1998.

The disadvantage of these laminates is that on-site, i.e. H. in the place where an object with the paint layer is to be equipped, systems for wet painting must be set up. Systems for wet painting are very expensive, for example due to the environmental regulations and comparatively problematic processing of not yet hardened liquid coating agents, in particular polyisocyanates containing two-component paints.  

Unsupported paint films are, for example, from the German patent DE 195 35 934 C1 known.

Lacquered foils for coating car body parts are from the German patent Writings DE 195 17 069 A1, DE 195 17 067 A1 or DE 195 17 068 A1 known. The parts coated with it have excellent stone chip resistance. The good Corrosion resistance can, however, be further optimized.

The use of foils for coating automotive exterior parts is particularly important through advances in thermoforming and the technique of "in mold decoration" of plastic molded parts of increasing interest. (E. Bürkle in Kunsstoffe 87 (1997), 320-328; Modern Plastics International Volume 11, 1997, 33-34, G. Steinbichler and J. Gießauf in Kunststoffe 87 (1997), 1262-1270).

The basic concept of such paint films is based on the fact that they are only on the substrate to be glued on. The necessary equipment for connecting sheet-like materials such as adhesive presses or calenders are comparatively simple and operate without problems. However, the corrosion stability of laminates these paint films and metals are still not sufficient for all applications. In addition, the paint films and foils may be detached or delaminated.

The object of the present invention is to find a new corrosion-stable laminate, which no longer has the disadvantages of the prior art, but rather a high one Has corrosion resistance and excellent interlayer adhesion and in simpler Way can be made.

Accordingly, the new laminate was found, which contains the following layers one above the other in the specified order:

• A) at least one layer which contains or consists of at least one metal,
• B) at least one layer of a plasma polymer and
• C) at least one film made of an organic material.

In addition, new processes for the production of the new laminate were found.

In the following, the new laminate is called the "inventive laminate" and the new ones Process for producing the laminate according to the invention as "according to the invention Procedure ".

Further objects according to the invention are evident from the description.

The laminate according to the invention contains at least one layer A), which is at least one Contains or consists of metal. According to the invention, it is advantageous if layer A) consists of at least one metal.

Examples of suitable metals to be used according to the invention are titanium, iron, cobalt, Nickel, magnesium, aluminum, zinc or their alloys with each other or with others suitable metals such as copper, vanadium, tungsten, molybdenum, chromium, manganese or tin. According to the invention, those metals which are customary in automobile construction are advantageous can be used for the production of bodies. You will therefore prefer one set.

Examples of suitable metals of this type to be used according to the invention are chairs, in particular special cold rolled steels and metal coated steel sheets.  

In itself, layer A) can have any shape, for example the shape a fender, a car door, a bonnet or a trunk lid. According to the invention, it is advantageous if the layer A) is planar and in particular as a sheet or tape is present.

The thickness of layer A) can vary widely and depends on the particular use purpose of the laminate according to the invention. Thicknesses of 0.05 mm are advantageous here up to 10 mm, as they are commonly used in automotive engineering.

The further essential component of the laminate according to the invention is at least one Layer B) made of a plasma polymer. Layer B) can be on one side or on both Sides of the metal sheets or strips to be used according to the invention become. Which variant is chosen depends on the intended one Intended use of metal sheets or strips.

The plasma polymer B) has a thickness of 5 to 200 nm, preferably 10 to 100 nm and in particular 20 to 60 nm.

The composition of the plasma polymer B) can be homogeneous or it can be change vertically in different ways. For one, the concentration of one Remove component within layer B) continuously or discontinuously or increase. If the concentration of functional groups varies, this becomes Plasma polymer B) called "gradient plasma polymer B)". This gradient Plasma polymer B) is characterized by the fact that it has special functional groups the phase boundary metal A) (with or without oxide layer) / plasma polymer B), for example organosilicon functional groups, and at the phase boundary plasma polymer B) / Adhesive D) (see below), for example hydroxyl, amino or carboxyl groups. This optimizes the adhesion at the interfaces, resulting in optimal stability of the laminate according to the invention. The heteroatom functions at the interface with  Metal A) bind to the oxide cover layer of metal A). The functional groups chemical bonds to the adhesive D) form on the surface of the plasma polymer B) out. However, the plasma polymer B) can also consist of layers of different compositions consist. In addition, the metal surface can be deposited prior to the deposition of the plasma polymer be treated with an oxygen plasma. Furthermore, the surface can Treatment can be functionalized with an oxygen plasma.

Examples of suitable plasma polymer layers B), starting compounds and Coating devices are described in the dissertation by G. Grundmeier, "Grenz Surface chemical and corrosion analysis of plasma polymer coatings tungen auf Stahl ", Technical Faculty of the University of Erlangen-Nuremberg, 1997, the Patent specifications EP 0 533 606 B1, EP 0 619 847 B1 or EP 0 515 373 B2 or the Articles by Tinghao F. Wang et al., "Corrosion protection of cold rolled steel by low temperature plasma interface engineering ", in Progress in Organic Coatings, volume 28, pages 291 to 297, 1996, or by G. Grundmeier and M. Stratmann, "Plasma polymerization - a new and promising way for the corrosion protection of steel ", Materials and Corrosion, Volume 49, pages 150 to 160, 1998.

The further essential component of the laminate according to the invention is at least one Foil C) made of organic material. In the context of the present invention, the Be "Film" also handled self-supporting lacquer films and foils.

The foils C) themselves can be constructed in one or more layers. What structure is chosen, depends on the optical and / or technical effect, which by the Foil C) should be achieved. Accordingly, pigmented or unpigmented, colored ones or uncoloured, matt or clear, transparent or opaque lacquer films or lacquered foils with a smooth, rough or structured surface.  

Examples of suitable films C) and their production are from German Patent application DE 195 35 934 A1 known. These foils C) consist of a carrier foil with a defined surface structure on which an electron beam hardened pigmented lacquer is applied. There is an adhesive layer on the lacquer layer, which is covered by a protective film. The protective film is removed for the application, and the film C) is connected to the substrate via the adhesive layer.

Further examples of suitable films C) and their production are from the German Patent applications DE 195 17 069 A1, DE 195 17 067 A1 or DE 195 17 068 A1 known. These films C) contain a carrier film made of plastic with a thickness of 10 to 500 µm, which can also be pigmented. There can be an effect layer on their surface, a filler layer and / or a pigmented lacquer layer can be applied. These layers can still be coated with a clear varnish or covered with a peelable film.

Also suitable as films C) are multilayer films whose clearcoat consists of thermoplastic polymers, e.g. B. polyvinylidene fluoride (PVdF). Such slides are for example commercially available as "In-Mold Surfacing Film" from 3M / REXAM.

In addition, there are those described in patent applications WO 94/09983 and EP 0 361 823 A1 multilayer films described as films C) into consideration. Their clear layers consist of PVdF / polyacrylate mixtures and their pigmented color layers on the basis PVdF or polyvinyl chloride are applied via a connection layer or directly thereon. These foils C) are applied to the molded part to be foiled via an adhesive layer, after an optional backing has been removed. Instead of the above Clear layers mentioned can also clear layers made of thermoplastic Polymethyl methacrylate (PMMA), preferably by coextrusion with the backing and / or base layer can be obtained (A. Grefenstein in Kunststoffe 87 (1997), 1332-1343), be used.  

Furthermore, a customary and known one can exist between layer B) and layer C) Glue and / or a primer D).

In the procedure according to the invention, the laminate according to the invention is produced by

• A) Providing a metal containing or consisting of at least one metal Layer A),
• B) producing a layer B) from a plasma polymer on at least one of the Surfaces of layer A) by plasma polymerization at least one suitable Starting compound,
• C) applying at least one film C) of organic material on the layer or layers B).

Process steps 1) to III) can be carried out using customary and known processes and Devices are carried out. In particular, the application of the film C) with Using conventional and known devices such as adhesive presses or calenders.

The following production method according to the invention proves to be particularly advantageous of the laminate according to the invention, which primarily serves its continuous production.

In the method according to the invention, a device ( 1 ) according to the invention is used, which is explained in more detail in FIG. 1. Fig. 1 shows the device (1) is not drawn to scale, but is intended to illustrate the essential functions of the device (1) in the sense of a diagrammatic sketch.

In the device ( 1 ), three pairs of rollers ( 2 ), ( 3 ) and ( 4 ) arranged one behind the other, together with suitable wall elements ( 5 ), form two reaction spaces ( 6 ) and ( 7 ). The pair of rollers ( 4 ) is coupled to a feed roller ( 8 ) and, together with a roller of the pair of rollers ( 4 ), serves to feed the film C) ( 9 ) through the nip ( 4 b) to the nip ( 4 a). The film C) ( 9 ) is optionally coated on the side which is connected to the layer A) with an adhesive D).

The device ( 1 ) further contains conventional and known feed devices and discharge devices for the starting compounds of plasma polymerization and for other substances such as inert gases, devices for generating vacuum, heat, cold and plasma, gas-tight locks, mechanical and electric motors, conveying devices, mechanical, pneumatic magnetic and electronic measuring and regulating devices, sealing devices and calender rolls, presses and winding devices as well as, if necessary, cutting devices for the laminates according to the invention. For the sake of clarity, these devices are not shown in FIG. 1.

The layer A) ( 10 ) is conveyed through the gap ( 2 a) of the first pair of rollers into the first reaction chamber ( 6 ), in which one of its surfaces ( 10 a) is treated with plasma, so that this surface ( 10 a) is cleaned and / or is provided with an oxidic cover layer. The layer A) ( 10 ) pretreated in this way is conveyed through the gap ( 3 a) of the second pair of rollers into the second reaction space ( 7 ), in which the plasma polymer B) is formed on the pretreated surface ( 10 a) by plasma polymerization of at least one suitable starting compound , The layer A) ( 10 ) coated on one side with the plasma polymer B) is conveyed further and its coated side is connected to the film C) ( 9 ) in the gap ( 4 a) of the roller pair ( 4 ), as a result of which the laminate ( 11 ) results.

The laminate ( 11 ) according to the invention can still be hot pressed and can be handled further in a customary and known manner. For example, it can be wound into coils and / or cut into smaller pieces. These can then be suitably shaped into three-dimensional objects.

It is an essential advantage of the device ( 1 ) and the method according to the invention that they can easily be modified so that the coating of layer A) ( 10 ) with the plasma polymers B) and the films C) can be carried out on both sides. For this purpose, only the same devices as described above need be added to the device ( 1 ) of FIG. 1 on the other side of layer A) ( 10 ). In addition, the mutually opposite plasma polymers B) and / or the mutually opposite films C) ( 9 ) can each differ from one another in terms of material, if the particular intended use so requires.

It is yet another essential advantage of the device ( 1 ) according to the invention that it can be expanded to include additional reaction spaces by adding further pairs of rollers, so that the method according to the invention can be varied very widely.

The laminate according to the invention has excellent adhesion of layers A), B) and C) among themselves. It is extremely stable against mechanical and chemical Exposure and exposure to radiation. Even after violent damage to the Laminates according to the invention prove to be corrosion-stable. Its special advantage lies in its deep-drawing ability, so that it can be easily molded, in particular Car body parts that can be molded.

Examples Production Example 1 The production of a plasma polymer B) on a steel sheet

The plasma polymer was used in the plant as described in the article by G. Grundmeier and M. Stratmann, "Plasma polymerization - a new and promising way for the corrosion protection of steel ", Materials and Corrosion, Volume 49, pages 150 to 160, 1998, manufactured. A multilayer plasma polymer according to the dissertation of G. Grundmeier, "Interface chemical and corrosion analysis by Plasma polymer coatings on steel ", Technical Faculty of the University of Erlangen- Nuremberg, 1997, pages 140 and 141. The process parameters are the tables 1 and 2.

Table 1

Plasma oxidation of the surface of the sheet

Table 2

Deposition of the plasma polymers and their functionalization with oxygen plasma

A plasma polymer B) with a thickness of 20 nm resulted.

example 1 Production of the Laminate 1 According to the Invention

A white pigmented thermoplastic 60 µm thick polyurethane film (Elastollan® EL 1184A from Elastogran GmbH) was fixed on a metal sheet and covered with a han the usual white pigmented non-aqueous top coat (dry film thickness: 20 µm). The basecoat is baked at 130 ° C for 30 minutes. On the painted side The film thus coated was a transparent polyester film (Melinex®, ICI), which with a 20 µm thick adhesive layer made of a polyester based on butanediol 1,4 and Terephthalic acid / isophthalic acid (1: 1) had been provided at a temperature of 150 ° C and a pressure of 25 bar. The laminate thus obtained was removed from the metal support detached and at a temperature of 220 ° C and a pressure of 50 bar to that with the Plasma polymer B) coated side of the steel sheet A) (cf. the manufacturing example) laminated.

Example 2 The Production of Laminate 2 According to the Invention

The adhesive layer with a 20 µm thick adhesive layer made of a poly ester based on butanediol 1,4 and terephthalic acid / isophthalic acid (1: 1), white pigmented, thermoplastic 60 µm thick polyurethane film (Elastollan® EL 1184A from  Elastogran GmbH) was covered with a release paper. Then it didn't covered side of the film with a commercially available white pigmented non-aqueous varnish painted (dry film thickness: 20 µm). The basecoat film was at 130 ° C for 30 minutes baked. A transparent polyester was applied to the painted side of the film so coated film (Melinex®, ICI), which has a 20 µm thick adhesive layer made of a polyester based on butanediol 1,4 and terephthalic acid / isophthalic acid (1: 1), pressed at a temperature of 150 ° C and a pressure of 25 bar. The so obtained Laminate was removed after removing the release paper at a temperature of 220 ° C and a pressure of 50 bar on the side coated with the plasma polymer B) Steel sheet A) (see the manufacturing example) laminated.

Testing of laminates 1 and 2 according to the invention

The laminates 1 and 2 according to the invention produced according to Examples 1 to 2 showed excellent resistance values in the VDA stone impact test (2 × 500 g at 2 bar) and in the Mercedes Benz ball shot test (VDA: grade 1; ball shot test: degree of rust = 0, degree of flaking): ≦ 2 mm ² ). To test the corrosion resistance, the coated substrates were provided with an approx. 10 cm long scratch, the depth of which extends as far as the metal sheet, and subjected to a salt spray test according to DIN 50 021. Even after 10 weeks, there was no rust under the Ritz.

Claims (12)

1. Laminate, which contains the following layers one above the other in the specified order:

• A) at least one layer which contains or consists of at least one metal,
• B) at least one layer of a plasma polymer and
• C) at least one film made of an organic material.

2. Laminate according to claim 1, characterized in that the layers adhered to each other are connected. 3. Laminate according to claim 1 or 2, characterized in that between the Layer B) and layer C) is an adhesive and / or a primer D) or are located. 4. Laminate according to one of claims 1 to 3, characterized in that it is the film C) around a single-layer or multi-layer, pigmented or unpigmen tied, colored or uncoloured, matt or clear, transparent or opaque lacquer film deals with a smooth, rough or structured surface. 5. Laminate according to one of claims 1 to 4, characterized in that on the free surface of the film C) there is a scratch-resistant coating.   6. Laminate according to one of claims 1 to 5, characterized in that the layer from a gradient plasma polymer B) a thickness of 5 to 40 nm, preferably Has 10 to 30 nm and in particular 15 to 25 nm. 7. The method for producing the laminate according to one of claims 1 to 6

• A) providing a layer A) containing or consisting of at least one metal,
• B) producing a layer B) from a plasma polymer on at least one of the surfaces of the layer A) and
• C) applying at least one film C) of organic material on the layer or layers B).

8. The device ( 1 ) for performing the method according to claim 7, comprising

• 1. at least a first pair of rollers ( 2 ) with a roller gap ( 2 a),
• 2. at least a second pair of rollers ( 3 ) with a roller gap ( 3 a),
• 3. at least a third pair of rollers ( 4 ) with a roller gap ( 4 a),
• 4. at least one feed roller 8 , which with a roller of the roller pair ( 4 )
• 5. is coupled and forms the nip ( 4 b) with it,

in which

• 1. the roller pairs ( 2 ), ( 3 ) and ( 4 ) are arranged one behind the other in such a way that a layer A) ( 10 ) can be conveyed through the roller nips ( 2 a), ( 3 a) and ( 4 a),
• 2. the roller ( 8 ) to the pair of rollers ( 4 ) is arranged so that a film C) ( 9 ) can be conveyed through the nip ( 4 b) to the nip ( 4 a), in which it with the layer A) to the laminate is connected, and
• 3. the roller pairs ( 2 ), ( 3 ) and ( 4 ) together with wall elements ( 5 ) form closed reaction spaces ( 6 ) and ( 7 ), the reaction space ( 6 ) cleaning the surface ( 10 a) and / or the Structure of an oxide cover layer on the surface ( 10 a) and the reaction space ( 7 ) serves to form the plasma polymer (B) on the surface ( 10 a).

9. The device ( 1 ) according to claim 8, characterized in that it contains at least one further pair of rollers, which together with an existing pair of rollers ( 2 ), ( 3 ) and / or ( 4 ) and the wall elements ( 5 ) at least one forms further reaction space. 10. The device ( 1 ) according to claim 8 or 9, characterized in that it on both sides of the layer A) ( 10 ) reaction spaces ( 6 ) and ( 7 ) and rollers ( 8 ) and nips ( 4 a) and ( 4th b) contains, so that the layer A) ( 10 ) can be coated on both sides with the plasma polymer B) and the film C) ( 9 ). 11. The device ( 1 ) according to claim 10, characterized in that the mutually opposite plasma polymers B) and / or the mutually opposite films C) ( 9 ) are each different in terms of material. 12. Use of the laminate according to one of claims 1 to 6, of the laminate produced according to claim 7 or of the laminate produced with the aid of the device ( 1 ) according to one of claims 8 to 11 for the production of molded parts, in particular automobile body parts.