Note: Descriptions are shown in the official language in which they were submitted.
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METHOD FOR PRODUCING COATED METAL SURFACES AND THE
USE OF SAID METAL SURFACES
The greseat i.z~yr.ntion relates to a method for producing
coated metal surfaces in which the coating cari be carried
out at high speed. such coatings are often. used under the
description "coif. coatit~.g" to coat strip materials .
The knoe,oa high-speed coati.ag methods have the disadvasitage
that the pretreatment and the priming (primer) are applied
is two separate steps.
The object of the invention is to provide a pxvceaa for the
7.args-scale industrial production of lacquered strip
material~ iri which the pretreatment and priming Can be
applied ~ only one work stage.
This object 3s achieved by s proceaD for producing abated
saetal surfaces at a coat~.ng speed of at least 25 m par
tniriute in the app7.icatioa of a pretreatment agent to a
cleaned azid/or piGkl.ed metal surface, which is
characterised in that at. least oaQ pretreatment agent, iri
particular a solution and/or dispersion, is applied to at
least one surface of a metal body after a cleaning aad/vr a
pickling of the metal surface to be treated and at least
ane lacquer layer is them. applied to a part of the
pratxeated surface, with the coati~,g produced auly using a
pretreatm~eat ag~t and not using a lacquer being used,
instead of a pretreatment layer and a priming layer, as
treattne~t Zayer .
Furthezttlore the obi ect is achieved by a process for
preducir~.g coated, metal surfaces ar a coating spe~ad of at
least 25 m per minute j.n the application of a pretreatmar~t
agent to a cleaned and/or p~,ckled metal Surface, which is
characterised in that at least one pretreatment agent, in
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2
particular a solution and/or dispersion, is applied to at
least one surface of a rnotal body after a cleaning and/or a
pickli~ag of the metal surface tc be treated and at least
one lacqsier layer is then, applied to a part of the
s pxezreated surface, with the coating treated with a
pretreatment agent being used, iuBtead v~ a pretreatment
layer and a priming layer, as treatment layer.
preferably the pretreated surfac~ or surfaces form otZe side
of a strip, in which optionally at least one of the narrow
edge surfaces of the strip may also be partially
pretreated.
Th~ coating speed ie preferably 40 to 5a0 m per minute,
~s particularly preferably.'75 to 160 m per minute. The
treatment layer thereby'aesu~aes the functions of the
primer. The other part of the pretreated surf$Ce is
"' subsequently x~.o longer coated with a lacguer in the strip
coating device. '
The method according to the invention cnay be employed eo
that moisture or residual moisture is retained in the
applied pretreatmexat layer until. lacquering is performed,
in order to adjust the necessary electrical conductivity of
Zs the pretreated surface for the application of the lacquer
layer.
The metal suxface may before r,hs pretreatment contain in
particular alumsaium, iron, coppQr, magnesium, zinc and/or
3o tits and may preferably coixsist of an aluminium alloy, a
hot-dip galvanised or electrolytically galvanised iron
material, a steel, a full zinc material in the form of
strips or metal sheets, or tinplate. In this connection
the bodies may be flat or shaped, or may be provided with
35 rece~rses, such as for example with a pe=toratec3 3tzv.ctvre .
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The xeeesses of a perforated plate may all have the same
geometry and eyes, or may optiox~,ally also have different
geoQtetries and sizes. for ex.~ernple Circular holes, elongate
holes or slits.
s
The aleaniug and/or th~ pickling of the metal surfaces may
be carried out by spraying and/or brushirig wa.th a cleaning
and/or pickling solution or immexaioa in a bath of this
solution.
to
The pretreatment of the cleaaaed and/or pickled surface may
be performed by spraying and squemaiag out, far exatseple
with a roller, by spraying and blowing off, for example
with compressed air. by immersion and egueezing out, for
15 example with a roller, by immersion and blowing off, for
example with compressed nix or in a roll-coat process.
With the roll-coat process the treatment liquid is app7.ied
with a coating roller in or against the direction of
mowetaent of the strip. Za all these process variants, no
20 sub$equent rinsing ie performed in order to prevent
removing and/or dattsa.ging the applied layer and to avoid
rinse water loaded with chemicals, wh3,ch for enviroz~,mantal
reasons, would have to be po9t-treated in a complex
procedure.
The pretreatment agent may be a preparation containing a
polymer dispersion with at least one resin fxo7n the group
consysting of aorylate, epoxide, phenol, polyester,
silicone polyester, polyurethane, styrene and urea-
3o formaldehyde based resin or a mixture thereof and/or a
mixed polymer.' The preparation coataina, apart from
volatile constituents, a non-volatile film-forming mixture.
The preparation tray contain at least one resin as solution
and/or as dispersion. The preparation tray contain. apart
~rotn r~ain(a) , at les,st orse inorgaa3,c additive in diaao~.ved
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form and/or as a finely divided powder, for exampl~ s.
carbonate, chrom,atte, oxide, phosphate, silicate or sulfate_
The pretreatment agent msy also be a resin-free
s preparation, with it being possible for the preparation to
coritain aluminium, fluoride, hydrofluoric said, pho~phate,
phosphoric acid, trivalent and/or hexavalent chromate,
chromic acid, silicate, silasse, t~unrsir~,, titanium. sine,
zirconium an.d/or self-organising molecules, for example
to based on phosphonatee, carboxylic acids, thiol8 and/or
silanes_
Fox the applicata.on to a metal strip a different
pretr~attnent agent may be chosen for ore side of the strip
15 than fat the other aide, with it baiag possible for the
side not intended to be subsequently lacquered to be coated
~rith a pretreatment agent containing organic resin. For
example only one side of the strip, say the upper side, is
possib7.y lacquered, whereas, on the opposite side, the
20 pretrea~tmeat acts as a final treatment .
After the applicatian of the treatment agent the layer may
either be partially dried or completely dried. This may be
carried out - especially with uniform strip speeds and when
as using exist~.ng_ovcas - by a shorter re~aidonce time under
the active d~-y~.~ng conditions, by a lower temperature in the
oven, and/or by a reduced air movement for the drying of
the strip.
3o Pxaf~rably at least one side of the pr~treated surface is
eQated with an, organic coating that hardens sufficiently
and/or cros6links in a time from 1 second up to 3 minutes,
particularly preferably from 5 seconds up co 2 minutes.
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For the coating of the pretreated surface, a poarder
laeguer, in partscular a powder leaguer having good
mechaaiCal properties, high scratch zes.istaace, good
adhe~ior~ and high flexibility as regards forming axed
shaping, ~.s preferab3.y applied and stowed. The powder
lacquer may ix~, this corureotion bC applied by spxayiag~
fluidised-bed powder sintering ax~.d~or powder cloud
technology and stowed. Powder cloud technology is
described i,~n" inter alia, EP-A-0 6'?8 X46&. Instead of by
IO conventional circulating air drying or fluidised air
dry3ag, the seoving may be carried out by, in p:rtiaulsr by
conductive drying using magnetic materials, andjor by
infra-red drying, in particular in the near infra-red
t~xRs .
is
The pretreatment layer a~ndlor tre:tment layer may, aftor
complete drying, have a layer thickness in the range from
o _ ~ to sa dun, preferably in the range from o . 5 to 10 ~.~m,
particularly preferably in the range from Z to 3 Win.
no
After the crosslinking, the stoned lacguer layer that ie
corztained on the pre-treatment layer may have a layer
thickness in the ra~ngs from S to 1000 Vim, preferably in the
range from 1o to 400 Vim, ar~,d particularly preferably is the
25 range from 15 to 60 Vim. 'When. using P'V'C plast~.sols it is
possible to recommend selection of a layer thickness in the
range f rdm 10 0 t o 3 0 0 ,butt .
In a preferred embodime~at of the enethc~d nrcordiag to the
3o invention a oac-layer cover lacquer ie applied as a single
lacquer to the strip to be coated.
A treatnneent layer that performs the function of a
pretreatment anoT at th~ aaMe time that of a primer can be
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formed with the pre, treatment agent. The primer ixt. this
connection perfozms the function o~ coxroaion pz~evsation,
satisfies the adhesion and flexibility requirements, and to
a mir~.or extent al9o pertorrns an aestb.etic fuzzatiox~,.
Theres may be used for the powder lacquer a ponder for a
single-colour uxistructured coating, a powder for a
multicolour t,~astructurcd coat~.ng, and/or a powder for a
multicolour structv.red contiag.
The coated surface may be protected,. is particular a~gaiaat
mechanical damage, for example during storage,
transportation sad fuxther proeoseirig, at least p3x~tially
by a film oz adhesive fa.ltn.
is
The coated bodies may optionally be shaped, cut -
especially in the longitudinal and/or transverse direction
- and optionahy re-formed, for example beaded, roll-
formed, deep-drawn axsd/or edged.
The product$ formed by the method according to the
invention may be used as internal and external panelling,
e~,uipment panell3.ag, c _ g. for domestic app3.ianoes and small
electrical instruments, is particular with decorated
ZS exterrial panelling, perforated metal sheets, especially for
loudspeakers and sound it~ulatit~g claddiz~g, xpac~ dividers,
partitions, furniture units, shalving, internal panelling
for vehicles and aircraft, such as for example
dashboardsliastrument pan.~is, frame and frame
constructions, facing matezials sad ~.ighti.z~g i~tallazions .
