DE2112751C3 - - Google Patents

Description

are self-supporting, they can be used as floor-standing. Side and ceiling parts of vehicles are used.

In practice there is a need for a metal composite element, which can be made with the help of a simple coating method.

The invention is based on the object of such a Metallvcrundclement, which easily and nevertheless is very stable. according to the usual coating methods to manufacture.

The product should be cheap and used for many technical purposes, e.g. B. in construction or in the electrical industry, especially for thermal and electrical insulation.

The invention proposes a method / ur production of insulating and corrosion-resistant Foam-metal composite elements. which is characterized in that the plastic powder in the dry-mixing process up to 2 percent by weight of peroxide dissolved in organic solvents and up to 10 percent by weight in organic solvents dissolved thermosetting plastics, preferably epoxy resins, are added and these Mixing according to the electrostatic coating method Injected onto one of the metal elcment sides and then foamed while on the other side of the metal element before, simultaneously with or after coating a plastic or Lacquer coating is applied, which burns in or dries during the thermal foaming process.

This addition of peroxides improves the properties of the foam, in particular its rigidity increased.

Such organic peroxides are, for example, di-tert-butyl peroxide, tert-butyl perbenzoate or dicumyl peroxide.

The usual liquid or solid propellants can be added to the plastic powder as propellants will. The solid ones are preferred. Nitrogen-releasing compounds are used.

Such compounds are, for example, azo compounds, sulfohydrazides or N-nitroso compounds. They are known under various trade names, such as Porofor (BAYER). Unicel (DuPont) and Vulcacel (ICI).

The invention is described in more detail with reference to the drawings and the following exemplary embodiments.

It shows

Fig. 1 is a schematic representation of the invention Foam-metal composite element,

2 shows the same composite element with an additional one plastic or lacquer coating applied to the metal,

3 shows the composite element shown in FIG. 2 in section.

It means

1 the metallic object to be coated,

2 the foam layer,

3 the plastic or paint layer.

wedge (1750 rpm) 10 percent by weight Epwudha «and Weight percent tert-butyl perbenzoate (all ^ ny. " percentages by weight refer to ethereal powder), both components in xylo the powder mixture in the ry-blend process

degrease system Sta

VUl IM «!». * · * - -

• Hey down, but sticks firmly. Dk so ciLiti. coated sheets are then in an oil-heated comb * «. Jan

aend at 200 C for 7 min ^ ^mebc ~ din _ften receives sheets having a uniform esthafa »the plastic Schaumbeschichlung in a Strong wn

⁸ ^ sn ^ onssehut, and Ellung cijs _g wished decors, the so far only ^ J * coated sheets of foam on the.andiuan side by means of a commercially available. Farbspnupis oc coated with an air-drying vinyl paint with a thickness of 150 µm.

it

Example 2

Example 1 A high pressure polyethylene powder (density 0.94 g ' cm ') of the grain size up to 100 μm is dry in a high-speed paddle mixer (Diosna mixer) with 20 percent by weight (calculated on polyethylene powder) of a mixture of azodicarbonamide and Zinc oxide mixed intimately at 1750 rpm for 3 minutes. Then beveled at the same mixer speed Aluminum sheets (99.5 "« Al) the Size 1020 ■ 75 <) 1.75 mm are carefully selected Solvent restoration first on one side with a thermosetting synthetic resin varnish based on it Alkyd melamine in a thickness of 80 µm by means of coated with a commercially available electrostatic paint spraying system. Then the sheets in a downstream commercial electrostatic powder spraying system with an applied High voltage of 28 kV coated with powder mixture A from Example 1 on the other side. Around a disruption of the decor on the already painted surface by the so-called To avoid "wrap-around" the powder, a mask is made with the opening .1015 x 745 mm used.

The even powder application is 310 to 315 µm, and the powder adheres very well. Finally, the metal sheets coated in this way are treated in an oil-heated chamber oven at 200 ° C. for 9 minutes for the purpose of drying and curing the lacquer layer and at the same time foaming the applied powder layer. The sheets produced in this way have a high-gloss, firmly adhering, very decorative coating of alkyd melamine on one side, while the other side is provided with a plastic foam layer with a uniform thickness of 9 mm.
⁶⁰ Example 3

Commercially available polyamide 11 fine powder (Rilsan) for electrostatic powder coating, 10 percent by weight azodicarbonamide is initially used for 3 min 65 long at 1800 rpm in a high speed paddle mixer intimately mixed. Then the powder becomes 4 percent by weight with the mixer running a solution consisting of 0.5 percent by weight

tcrt.Butylpcrbcnzoate. 1.5 weight percent epoxy resin (Epikotc) dissolved in 3.5 percent by weight benzyl alcohol is added and the mixture is intimately mixed for a further 5 minutes (All quantities given as percentages by weight are based on polyamide-11 fine powder).

With this powder mixture, degreased steel sheets of size 350 × 210 × 1 mm are removed by means of a Commercially available electrostatic powder spraying equipment coated on one side at 40 kV voltage. Simultaneously the metal sheets from the other side are also applied by means of an electrostatic powder spray gun 40 kV coated with untreated Rilsan fine powder in gray. To a disruption of the Rilsan coating The coating is made using a mask with the opening 345 x 205 mm.

The powder coating hangs very firmly; no powder falls off even if the metal sheets hit or hit.

The sheets are then placed in an electrically heated convection oven at a temperature treated at 220 C for 7 minutes. After cooling the sheets in the air, sheets are obtained that open one side with an even, firmly adhering, pore-tight, decorative coating of Rilsan with a thickness of 180 µm. while the other side with a Rilsan hemodial layer in one Thickness of 4 mm is provided.

This layer is also uniform and firmly adhering.

The advantages achieved by the invention are in particular that it is possible in a simple manner. manufacture insulating foam-metal composite cmcntc, which is characterized by excellent mechanical Characteristics with low weight at the same time.

The particular advantage of the manufacturing process is that only one coating method is used needs to become. With the help of the well-known electrostatic coating method, im Within the scope of the invention, both the foam and the lacquer layer are applied, with both sides from the same or different Plastics can exist. Since there is practically no loss of powder, the method is special economical, especially since there is the possibility of saving material because very thin layers are applied can be.

Since both layers also have a joint heat problem can be subjected, there is also the saving of an operation.

Both layers, the plastic or lacquer layer and the foam layer, adhere extremely well solid, have a good flow and an even layer thickness. The alliance can bent or otherwise deformed without the risk of the layers flaking off. on The reason for the high load-bearing capacity of the

Ben Scriaumstoff-Mctall-Verbundcmcnte connected with high insulation properties against cold. Heat and sound, these can be used as prefabricated components for partition walls. Roof constructions and the like, for example in prefabricated house construction, can be used. If if desired, both the foam layer and the lacquer layer can be colored. The parts are Can be used on both sides, are corrosion-resistant and have a good decorative appearance.

1 sheet of drawings

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Claims (1)

1 2 Riese, »Dissolving paint system set (1 <J67 |. Claim: p. 325'326). It is also known to produce foamed plastic processes for the manufacture of insulating products by deforming a plastic mixed with a corrosion-protected foam-metal friction agent, attaching elements using thermal contact on this molding made of threads or i -Applies fiber-foaming thermo or formed fleece with active agents and the whole thing snaps out under the action of heat on one end of thermoplastic plastic powder (German and a coating on the other metal Offenlegunasschrift 1 801 537).
Element-side, thereby marked-io To the strength and stability of such produced. It has also been proposed to increase the amount of plastic powder in the dry state, between mixing process up to 2 percent by weight in organically two such molded articles, on the outside of which there are solvents dissolved peroxide and until a fleece is applied. a reinforcing insert to K) weight percent Γη organic solution cinzuschäum. these inserts made of thermosetting plastics dissolved in metal, provided inorganic or organic substances, preferably epoxy resins, are added and are present and this mixture can be present as surface patterns according to the electrostatic specification (German Offenlegungsschrift 1807 225).
layering method on the one of the metal The German Oflcnlcgungsschrift 1 80S 077 Sprayed on Ekment pages and then written down a process for the production of light foams is, while on the other side of the composite body from a stable layer, one from Metal element before, at the same time with or after foamed plastic core and one the coating is a plastic or lacquer overlay, with the stable layer for example / ug is applied, the plastic molding process containing a propellant in the case of thermal metal burns in or dries. Forming is applied to it one made of threads 25 or fibers formed sheet and then the whole is heated for the purpose of foaming will. When making foam covers according to The Wirbetsintcrmethodc are coated on all sides Obtain good items, which is not always desirable. In order to avoid it, one can The invention relates to a method for manufacturing coating the location to be kept free with a len are covered by insulating and corrosion-resistant mask, but this method is Foam metal composite elements under Understandable. use of thermally foamable blowing agent 35 So far, no processes have become known containing thermoplastic or thermosetting plastic electrostatic way foam coatings with powder on one side and a cover on the stelien. During the stoving process Metal element side. zens of the applied thermoplastic plastic In the case of composite elements of this type, powder is required, and the powder easily falls off. wolich, that the applied layer of display material is created firmly on 40 due to not only unequal layer thicknesses, adheres to the substrate. The foam layers but also some areas remain uncoated, should have a uniform structure and easily to be raised. "largely by applying a primer beforehand It is known to prevent firmly adhering foam coatings and at the same time prevent adhesion to the by improving the substrate to be covered. So z. B. the pieces heated and then according to the Wirbel Austrian patent application A 5143/65 "before, sintering method in whirled up, next to choose the deposition voltage with a drive so that dipped medium mixed plastic powder. After a layer of well adhering to the base material Remove the workpieces with one of the resin and then by changing the thin foam layer covered (Austrian 50 separation conditions the actual top layer Patent Specification 259 726). is deposited from thermoplastic material, Should particularly firmly adhering foam layers, then the two layers together th are obtained, one covers the counter-melted. it would be advisable to use a bonding agent beforehand. These processes, however, require special conditions. the intermediate layer (Austrian patent 55) or additional operations so that they 276 781). whereby one can also proceed in such a way that are uneconomical. to begin with the plastic containing the propellant- By applying fleece to the propellant- Mixture applies and only then for the purpose of foaming-containing plastic and subsequent foaming heated (Austrian patent specification 284 301). especially if these products It is also known. Items with the help of elec- 60 contain a reinforcing insert. Products more static Coating methods to coat. that despite their low specific weight The application of the powder is done with handeis- are very stable and for many technical purposes, eg. B. common electrostatic powder spray guns. The one for thermal and electrical insulation in which Electrically charged powder particles are used to lid the construction industry in electrical engineering Covering objects can be sprayed on and encased 65. len this with a uniform layer of powder. This also applies to the well-known lightweight composite The powder can be melted down immediately after application without any special post-treatment layer are carried out according to customary methods (W.A. of manufacture. As these parts