U.S. patent application number 10/483503 was filed with the patent office on 2004-09-09 for color-and/or effect producing films, method for production and use thereof.
Invention is credited to Hintze-Bruning, Horst, Lassmann, Walter, Strickmann, Frank.
Application Number | 20040175572 10/483503 |
Document ID | / |
Family ID | 7695631 |
Filed Date | 2004-09-09 |
United States Patent
Application |
20040175572 |
Kind Code |
A1 |
Hintze-Bruning, Horst ; et
al. |
September 9, 2004 |
Color-and/or effect producing films, method for production and use
thereof
Abstract
Single-layer or multilayer color and/or effect films comprising
a color and/or effect layer, preparable by (1) continuously
applying a component amount of a basecoat material (A) by means of
a directed application technique to a carrier, the applicator (1)
and the carrier being in relative motion with respect to one
another, to construct a portion of the color and/or effect layer,
(2) at least once, continuously applying the remainder of the
basecoat material (A) and/or a basecoat material (B), which is
different than the basecoat (A), to the component layer (1) formed
by an application technique (2) which in the resulting component
layer (2) induces no arrangement of the pigments in a preferential
direction, the applicator (2) and the carrier being in relative
motion with respect to one another, to further or fully construct
the color and/or effect layer, and (3) drying or partly or fully
curing the color and/or effect layer.
Inventors: |
Hintze-Bruning, Horst;
(Munster, DE) ; Strickmann, Frank; (Steinfurt,
DE) ; Lassmann, Walter; (Munster, DE) |
Correspondence
Address: |
BASF CORPORATION
ANNE GERRY SABOURIN
26701 TELEGRAPH ROAD
SOUTHFIELD
MI
48034-2442
US
|
Family ID: |
7695631 |
Appl. No.: |
10/483503 |
Filed: |
January 8, 2004 |
PCT Filed: |
August 10, 2002 |
PCT NO: |
PCT/EP02/08982 |
Current U.S.
Class: |
428/422.8 ;
427/248.1; 428/323; 428/331 |
Current CPC
Class: |
B32B 27/36 20130101;
B32B 37/153 20130101; B05D 7/52 20130101; Y10T 428/259 20150115;
B05D 5/068 20130101; B32B 7/12 20130101; B32B 27/20 20130101; B32B
2307/4026 20130101; Y10T 428/31504 20150401; B32B 2398/20 20130101;
Y10T 428/31547 20150401; B32B 2605/00 20130101; B32B 2367/00
20130101; B32B 27/08 20130101; B05D 7/57 20130101; Y10T 428/25
20150115 |
Class at
Publication: |
428/422.8 ;
427/248.1; 428/323; 428/331 |
International
Class: |
B32B 005/16 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 16, 2001 |
DE |
101 40 205.8 |
Claims
What is claimed is:
1. A single-layer or multilayer color and/or effect film which
consists of or comprises at least one color and/or effect layer
preparable by (1) continuously applying a component amount or the
total amount of at least one basecoat material (A) by means of a
directed application technique to a carrier, the applicator (1) and
the carrier being in relative motion with respect to one another,
to construct a portion of the color and/or effect layer, (2) once,
or at least twice, continuously applying the remainder of the
basecoat material (A) and/or at least one basecoat material (B),
which is different than the basecoat(s) (A), to the component layer
(1), formed in step (1), by at least one application technique (2)
which in the resulting component layer (2) induces no arrangement
of the pigments in a preferential direction, the applicator(s) (2)
and the carrier being in relative motion with respect to one
another, to further or fully construct the color and/or effect
layer, and (3) drying or partly or fully curing the resulting color
and/or effect layer.
2. The film as claimed in claim 1, wherein step (2) can be carried
out in time immediately after step (1), i.e., simultaneously with
step (1).
3. The film as claimed in claim 1 or 2, wherein step (2) can be
carried out in time later after step (1), i.e., sequentially.
4. The film as claimed in any of claims 1 to 3, wherein the
component layer (1) formed in step (1) has more than 50% of the
thickness of the color and/or effect layer.
5. The film as claimed in any of claims 1 to 4, wherein the
directed application techniques of step (1) are casting, knife
coating, roller application or extrusion coating.
6. The film as claimed in claim 5, wherein the applicators (1) are
casting devices, knife coaters, rollers or extruders.
7. The film as claimed in any of claims 1 to 6, wherein the
applicators (1) are stationary.
8. The film as claimed in any of claims 1 to 7, wherein the carrier
is temporary or permanent.
9. The film as claimed in any of claims 1 to 8, wherein the carrier
is a solid film or a film which is not yet solidified.
10. The film as claimed in claim 9, wherein the carrier film is
composed of at least one thermoplastic.
11. The film as claimed in any of claims 1 to 10, wherein the
component layer (1) is vented before step (2).
12. The film as claimed in any of claims 1 to 11, wherein the
assembly comprising carrier and component layer (1) is wound up
before step (2).
13. The film as claimed in any of claims 1 to 12, wherein the
assembly comprising carrier, component layer (1) and first
component layer (2) is wound up before the further step (2).
14. The film as claimed in any of claims 1 to 12, wherein the layer
formed in the first step (2) is the complete color and/or effect
layer (2).
15. The film as claimed in any of claims 1 to 14, wherein the
application techniques (2) are spray application techniques and the
applicators (2) are spray applicators.
16. The film as claimed in claim 15, wherein the spray applicators
(2) are electrostatic or pneumatic devices.
17. The film as claimed in any of claims 1 to 16, wherein the
applicator(s) (2) is or are arranged directly downstream of the
applicator (1).
18. The film as claimed in any of claims 1 to 17, wherein the
applicator(s) (2) is or are arranged stationarily.
19. The film as claimed in claim 18, wherein the stationary
applicator(s) (2) is or are arranged transversely and/or obliquely
to the direction of motion of the assembly comprising carrier and
component layer (1) and also, where appropriate, first component
layer (2).
20. The film as claimed in any of claims 1 to 17, wherein the
applicator(s) (2) is or are arranged in such a way as to be movable
backward and forward transversely and/or obliquely to the direction
of motion of the assembly comprising carrier and component layer
(1) and also, where appropriate, first component layer (2).
21. The film as claimed in any of claims 1 to 20, wherein the
applicator(s) (2) is or are movable in the vertical plane.
22. The film as claimed in any of claims 1 to 21, wherein the
application direction(s) of the applicator(s) (2) is or are
vertical and/or oblique with respect to the plane of the assembly
comprising carrier and component layer (1) and also, where
appropriate, component layer (2).
23. The film as claimed in claim 22, wherein the application
direction(s) is or are aligned in and/or against the direction of
motion of the assembly comprising carrier and component layer (1)
and also, where appropriate, first component layer (2).
24. The film as claimed in any of claims 15 to 23, wherein the
basecoat spray jet clouds produced by the applicator(s) (2)
overlap.
25. The film as claimed in any of claims 16 to 24, wherein the
pneumatically produced basecoat spray jet cloud(s) is or are set in
periodic motion relative to its or their spraying direction and
relative to the carrier.
26. The film as claimed in any of claims 1 to 25, wherein the color
and/or effect layer is covered with a clearcoat film or with a
clearcoat.
27. The film as claimed in any of claims 1 to 26, which has the
automotive construction comprising electrocoat or anticorrosion
layer, primer-surfacer coat or anti stonechip primer, if desired,
basecoat, and clearcoat.
28. A single-layer or multilayer color and/or effect film which
consists of or comprises at least one color and/or effect layer
comprising (1) at least one component layer (1) comprising at least
one color and/or effect pigment (1) in anisotropic distribution,
and (2) at least one component layer (2) comprising the pigment or
pigments (1) and/or at least one different color and/or effect
pigment (2) in isotropic distribution.
29. The film as claimed in claim 28, wherein the pigments (1)
and/or (2) have an aspect ratio >1.
30. The film as claimed in claim 28 or 29, wherein pigments (1) in
component layer (1) are aligned in a preferential direction.
31. The film as claimed in any of claims 28 to 30, wherein the
color and/or effect layer is joined to a permanent carrier.
32. The film as claimed in any of claims 28 to 31, wherein the
color and/or effect layer is joined to a clearcoat film.
33. The film as claimed in any of claims 28 to 32, which has the
automotive construction comprising electrocoat or anticorrosion
layer, primer-surfacer coat or antistonechip primer, if desired,
basecoat, and clearcoat.
34. A process for preparing a single-layer or multilayer color
and/or effect film as claimed in any of claims 1 to 33, which
comprises (1) continuously applying a component amount or the total
amount of at least one basecoat material (A) by means of a directed
application technique to a carrier, the applicator (1) and the
carrier being in relative motion with respect to one another, to
construct a portion of the color and/or effect layer, (2) once, or
at least twice, continuously applying the remainder of the basecoat
material (A) and/or at least one basecoat material (B), which is
different than the basecoat(s) (A), to the component layer (1),
formed in step (1), by at least one application technique (2) which
in the resulting component layer (2) induces no arrangement of the
pigments in a preferential direction, the applicator(s) (2) and the
carrier being in relative motion with respect to one another, to
further or fully construct the color and/or effect layer, and (3)
drying or partly or fully curing the resulting color and/or effect
layer.
35. The process as claimed in claim 34, wherein component layer (1)
is vented before step (2).
36. The process as claimed in claim 34 or 35, wherein the assembly
comprising carrier and color and/or effect layer is wound up onto
rolls.
37. The process as claimed in any of claims 34 to 36, wherein the
color and/or effect layer is detached from the carrier.
38. The process as claimed in any of claims 34 to 37, wherein the
color and/or effect layer is joined to a clearcoat film or a
clearcoat.
39. The use of a film as claimed in any of claims 1 to 33 or of a
film prepared by the process as claimed in any of claims 34 to 38
for the decorative and/or protective coating of motor vehicle
bodies and parts thereof, the interior and exterior of motor
vehicles, the inside and outside of buildings, doors, windows,
furniture, and also in the context of the industrial coating of
small parts, coils, containers, packaging, electrical components,
and white goods.
40. The use as claimed in claim 39, wherein the films are used as a
multilayer color and/or effect basecoat/clearcoat system of coating
motor vehicle bodies and parts thereof
Description
[0001] The present invention relates to novel color and/or effect
films. The present invention also relates to a novel process for
preparing color and/or effect films. The present invention
additionally relates to the use of the novel color and/or effect
films for coating three-dimensional shaped parts, especially motor
vehicle bodies.
[0002] Color and/or effect paint systems on motor vehicle bodies,
especially automobile bodies, are nowadays preferably composed of a
plurality of coating layers which are applied atop one another and
have different properties.
[0003] By way of example, a substrate will have applied to it
successively an electrodeposited electrocoat as primer, a
primer-surfacer or antistonechip primer coat, a basecoat, and a
clearcoat.
[0004] Within this system, the electrocoat serves in particular to
protect the sheet metal against corrosion. By those in the art it
is often also referred to as the primer.
[0005] The primer-surfacer coat serves to mask unevennesses in the
substrate and, by virtue of its elasticity, ensures stonechip
resistance. Where appropriate, the primer-surfacer coat may also
serve to strengthen the hiding power and to deepen the shade of the
paint system.
[0006] The basecoat contributes the colors and/or the
angle-dependent optical effects. Both the brightness (amount) and
the color (through wavelength-specific absorption or through
interference) of the reflected light may vary depending on the
viewing angle, a phenomenon which is also referred to as brightness
and/or color flop.
[0007] The clearcoat serves to intensify the optical effects and to
protect the paint system against mechanical and chemical
damage.
[0008] Basecoat and clearcoat are often also referred to
collectively as the topcoat. For further details, refer to Rompp
Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart,
N.Y., 1998, pages 49 and 51, "automotive finishes".
[0009] A disadvantage is that these color and/or effect paint
systems must often be applied in four separate steps, between each
of which the applied films must be flashed off and also, where
appropriate, baked, which is very time-consuming and
labor-intensive and also leads to increased energy and plant costs.
A further disadvantage is the environmental burden associated with
the use of paints containing solvent.
[0010] Moreover, it has come to be recognized in the art that the
application conditions for the basecoat materials in particular may
greatly influence the color and flop characteristics of the
basecoats. In respect of the applied basecoat films, similar
comments are true for different drying conditions which have to be
set owing to the use of different substrates, such as plastics and
metals. In practice, these factors necessitate elaborate measures
for color matching between components which abut one another
directly on a vehicle body.
[0011] More recently, in order to avoid these problems from the
outset, multilayer color and/or effect films have been proposed for
the coating of motor vehicle bodies, especially exterior parts of
motor vehicle bodies. These known multilayer color and/or effect
films can be prepared under constant conditions and applied to any
desired substrates to give, as a result, a substrate- and
process-independent color and/or optical effect. Application may be
carried out by laminating onto metals, injection backmolding with
thermoplastics, foam backing, or compression backmolding. The
corresponding processes and films are known, for example, from the
American patents U.S. Pat. No. 4,810,540 A, U.S. Pat. No. 4,931,324
A or U.S. Pat. No. 5,114,789 A, the European patents EP 0 266 109
B1, EP 0 285 071 B1, EP 0 352 298 B1 or EP 0 449 982 B1, the
European patent applications EP 0 949 120 A1, EP 0261 815 A1 or EP
0050 794 A1 or the international patent application WO
96/40449.
[0012] From the European patent application EP 0 949 120 A1 in
particular a multilayer color and/or effect film is known in which
located between the basecoat and the clearcoat there is a so-called
adjustment layer with a thickness of from 2.5 to 25 .mu.m in order
to adjust the color of the basecoat toward a specified standard.
The basecoat, which is approximately 25 .mu.m thick, is produced by
extrusion, and the adjustment layer is applied by means of printing
techniques. A solution to the problems bound up with a directed
application process in which the pigments are aligned in a
preferential direction is not offered in the patent
application.
[0013] Whereas the advantages described may be realized with simple
colors, such as solid colors, this is not the case with demanding
effect paints, such as metallic effects. Because the known films
are generally produced by a directed process, such as extrusion to
form flat films or the casting of liquid basecoat materials onto
carrier films, the color locus and the flop characteristics of the
color and/or effect layers are not isotropic; in other words, when
the layers are viewed from different angles relative to the
preferential direction of the production process, different colors
and effects are perceived. The reason for this is the orientation
of the platelet-shaped effect pigments, such as platelet-shaped
aluminum pigments, which have an aspect ratio >1, in the
direction determined by the production. A further inhomogeneity is
generated by the statistically preferred orientation of the surface
normals of the platelet-shaped effect pigments relative to the
plane of the substrate in said preferential direction. When the
known multilayer color and/or effect films are processed to
homogeneously colored coatings for motor vehicle bodies, these
disadvantageous effects result in an increased logistical effort
and in large quantities of offcuts, which significantly curtails
the economics of the coatings.
[0014] It is true that these disadvantages could be eliminated by
preparing the color and/or effect layers by spray application of
basecoat materials, which normally provides isotropic coatings. To
do so, however, would introduce other disadvantages, for the
reasons set out below.
[0015] Taken overall, the known multilayer color and/or effect
films are considerably thicker than the conventional multicoat
color and/or effect paint systems. In particular, the color and/or
effect layers of the films are required to be from more than two up
to four times thicker than the basecoats of conventional multicoat
paint systems in order to retain a sufficiently high hiding power
under the conditions of stretching which occur during the coating
of three-dimensional articles, and which may amount to more than
200%, and to suffer as little change as possible in color and
optical effect.
[0016] Economic preparation of thick, isotropic color and/or effect
layers by spray application is, however, not possible owing to the
comparatively low application rate and the normally low solids
contents of color and/or effect basecoat materials.
[0017] The disadvantages set out above arise not only when using
effect pigments which give rise to optical effects but also in the
case of electrically conductive, magnetically shielding or
fluorescent pigments.
[0018] It is an object of the present invention to provide novel
color and/or effect, single-layer or multilayer films which can be
prepared economically and which no longer have the disadvantages of
the prior art. In particular, it is intended that the novel
multilayer color and/or effect films should exhibit isotropic flop
characteristics and an isotropic color locus, both independently of
the viewing angle, so that their processing to coatings for
three-dimensional articles, especially motor vehicle bodies, is no
longer accompanied by any logistical problems or any large
quantities of offcuts. Even in the stretched areas, the novel
coatings produced from the novel single-layer or multilayer color
and/or effect films should continue to have a sufficiently high
hiding power and to suffer very little if any change in color and
effect. Overall, in terms of gloss, distinctiveness of image,
uniformity of hiding ability, uniformity of film thickness,
resistance to motor fuel, solvents and acids, hardness, abrasion
resistance, mar resistance, impact strength, adhesion, weathering
stability, and resistance to water and humidity, the novel coatings
should exhibit the so-called "automotive quality" (in this respect,
cf. also the European patent EP 0 352 298 B1, page 15 line 42 to
page 17 line 40).
[0019] The invention accordingly provides the novel single-layer or
multilayer color and/or effect films which consist of or comprise
at least one color and/or effect layer comprising
[0020] (1) at least one component layer (1) comprising at least one
color and/or effect pigment (1) in anisotropic distribution,
and
[0021] (2) at least one component layer (2) comprising the pigment
or pigments (1) and/or at least one different color and/or effect
pigment (2) in isotropic distribution.
[0022] The invention also provides the novel single-layer or
multilayer color and/or effect films which consist of or comprise
at least one color and/or effect layer preparable by
[0023] (1) continuously applying a component amount or the total
amount of at least one basecoat material (A) by means of a directed
application technique to a carrier, the applicator (1) and the
carrier being in relative motion with respect to one another, to
construct a portion of the color and/or effect layer,
[0024] (2) once, or at least twice, continuously applying the
remainder of the basecoat material (A) and/or at least one basecoat
material (B), which is different than the basecoat(s) (A), to the
component layer (1), formed in step (1), by at least one
application technique (2) which in the resulting component layer
induces no arrangement of the pigments in a preferential direction,
the applicator(s) (2) and the carrier being in relative motion with
respect to one another, to further or fully construct the color
and/or effect layer, and
[0025] (3) drying or partly or fully curing the resulting color
and/or effect layer.
[0026] In the text below, the novel single-layer or multilayer
color and/or effect films are referred to collectively as "films of
the invention".
[0027] The invention further provides the novel process for
preparing single-layer or multilayer color and/or effect films
which comprises
[0028] (1) continuously applying a component amount or the total
amount of at least one basecoat material (A) by means of a directed
application technique to a carrier, the applicator (1) and the
carrier being in relative motion with respect to one another, to
construct a portion of the color and/or effect layer,
[0029] (2) once, or at least twice, continuously applying the
remainder of the basecoat material (A) and/or at least one basecoat
material (B), which is different than the basecoat(s) (A), to the
component layer (1), formed in step (1), by at least one
application technique (2) which in the resulting component layer
induces no arrangement of the pigments in a preferential direction,
the applicator(s) (2) and the carrier being in relative motion with
respect to one another, to further or fully construct the color
and/or effect layer, and
[0030] (3) drying or partly or fully curing the resulting color
and/or effect layer (2).
[0031] In the text below, the novel process for preparing
single-layer or multilayer color and/or effect films is referred to
as the "process of the invention".
[0032] In the light of the prior art it was surprising and
unforeseeable for the skilled worker that the object on which the
present invention was based could be achieved by means of the films
of the invention and by means of the process of the invention.
[0033] In particular it was surprising that a comparatively thin,
isotropic color and/or effect layer with isotropically arranged
color and/or effect pigments atop a comparatively thick,
anisotropic color and/or effect layer with anisotropically
arranged--that is, aligned in a preferential direction--color
and/or effect pigments gave rise to the same or virtually the same
color and/or the same optical and/or other physical effect as a
completely isotropic layer.
[0034] Even more surprising was that by means of the process of the
invention it was possible in a simple way to prepare films of the
invention comprising at least two color and/or effect layers of
different color and/or effect one above the other, thereby making
it possible to produce decorative and/or physical effects which
were otherwise difficult to produce.
[0035] Above all, however, the films of the invention surprisingly
exhibited an isotropic flop behavior and an isotropic color locus,
both of which were independent of the viewing angle, so that their
processing to coatings for three-dimensional articles, especially
motor vehicle bodies, was no longer accompanied by any logistical
problems or any large quantities of offcuts. The coatings of the
invention produced from the films of the invention surprisingly
continued to have a sufficiently high hiding power, even in the
extended areas.
[0036] Overall, as regards gloss, distinctiveness of image,
uniformity of hiding ability, uniformity of film thickness,
resistance to motor fuel, solvents and acids, hardness, abrasion
resistance, mar resistance, impact strength, adhesion, weathering
stability, and resistance to water and humidity, the novel coatings
were of "automotive quality".
[0037] The films of the invention comprise at least one, especially
one, color and/or effect layer, or consist thereof.
[0038] In special cases, the films of the invention may comprise at
least two, especially two, color and/or effect layers one above the
other, the upper layer(s) fully or partly, especially partly,
covering the underlying layer(s). Preferably, the partial coverage
is of imagewise configuration. In this way it is possible to
combine not only different colors but also different physical and
optical effects with one another for the purpose, for example, of
information or signaling.
[0039] The films of the invention may be prepared in any of a very
wide variety of ways; preferably, they are produced by means of the
process of the invention.
[0040] In the process of the invention, at least one, especially
one, basecoat material (A) or at least one, especially one,
basecoat material (A) and at least one, especially one, basecoat
material (B) different than the basecoat material (A) is used.
[0041] The material composition of the basecoat materials (A) and
(B) is not critical;
[0042] rather, it is possible to use the customary and known,
conventional or aqueous basecoat materials, such as are known, for
example, from the American patent U.S. Pat. No. 5,114,789 A, column
7 line 41 to column 8 line 33, column 11 lines 24 to 50, and column
13 lines 30 to 40, the European patent EP 0 352 298 B1, page 9 line
19 to page 12 line 38, or the patent applications EP 0 089 497 A1,
EP 0 256 540 A1, EP 0 260 447 A1, EP 0 297 576 A1, WO 96/12747, EP
0 523 610 A1, EP 0 228 003 A1, EP 0 397 806 A1, EP 0 574 417 A1, EP
0 531 510 A1, EP 0 581 211 A1, EP 0 708 788 A1, EP 0 593 454 A1, DE
43 28 092 A1, EP 0 299 148 A1, EP 0 394 737 A1, EP 0 590 484 A1,
EP0 234 362 A1, EP 0 234 361 A1, EP 0 543 817 A1, WO 95/14721, EP 0
521 928 A1, EP 0 522 420 A1, EP 0 522 419 A1, EP 0 649 865 A1, EP0
536 712 A1, EP 0 596 460 A1, EP 0 596 461 A1, EP 0 584 818 A1, EP0
669 356 A1, EP 0 634 431 A1, EP 0 678 536 A1, EP 0 354 261 A1, EP0
424 705 A1, WO 97/49745, WO 97/49747, EP 0 401 565 A1, EP 0 496 205
A1, EP 0 358 979 A1, EP 0 469 389 A1, DE 24 46 442 A1, DE 34 09 080
A1, DE 195 47 944 A1, DE 197 41 554 A1 or EP 0 817 684, column 5
lines 31 to 45.
[0043] It is essential that the basecoat materials (A) and/or (B)
comprise color and/or effect pigments. The color and/or effect
pigments are preferably selected from the group consisting of
organic and inorganic, colored, optical effect-imparting,
electrically conductive, magnetically shielding, and fluorescent
pigments, metal powders, organic and inorganic, transparent and
hiding fillers, and nanoparticles. The pigments preferably have an
aspect ratio >1.
[0044] Examples of suitable effect pigments are metal flake
pigments such as commercially customary aluminum bronzes, aluminum
bronzes chromated in accordance with DE 36 36 183 A1, and
commercially customary stainless steel bronzes, and also
nonmetallic effect pigments, such as pearlescent pigments and
interference pigments, platelet-shaped effect pigments based on
iron oxide with a shade from pink to brownish red, or
liquid-crystalline effect pigments. For further details, refer to
Rompp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998,
page 176, "effect pigments" and pages 380 and 381, "metal
oxide-mica pigments" to "metal pigments" and to the patent
applications and patents DE 36 36 156 A1, DE 37 18 446 A1, DE 37 19
804 A1, DE 39 30 601 A1, EP 0 068 311 A1, EP 0 264 843 A1, EP 0 265
820 A1, EP 0 283 852 A1, EP 0 293 746 A1, EP 0 417 567 A1, U.S.
Pat. No. 4,828,826 A or U.S. Pat. No. 5,244,649 A.
[0045] Examples of suitable inorganic color pigments are white
pigments such as titanium dioxide, zinc white, zinc sulfide or
lithopones; black pigments such as carbon black, iron manganese
black or spinel black; chromatic pigments such as chromium oxide,
chromium oxide hydrate green, cobalt green or ultramarine green,
cobalt blue, ultramarine blue or manganese blue, ultramarine violet
or cobalt violet and manganese violet, red iron oxide, cadmium
sulfoselenide, molybdate red or ultramarine red; brown iron oxide,
mixed brown, spinel phases and corundum phases or chrome orange; or
yellow iron oxide, nickel titanium yellow, chrome titanium yellow,
cadmium sulfide, cadmium zinc sulfide, chrome yellow or bismuth
vanadate.
[0046] Examples of suitable organic color pigments are monoazo
pigments, disazo pigments, anthraquinone pigments, benzimidazole
pigments, quinacridone pigments, quinophthalone pigments,
diketopyrrolopyrrole pigments, dioxazine pigments, indanthrone
pigments, isoindoline pigments, isoindolinone pigments, azomethine
pigments, thioindigo pigments, metal complex pigments, perinone
pigments, perylene pigments, phthalocyanine pigments or aniline
black.
[0047] For further details, refer to Rompp Lexikon Lacke und
Druckfarben, Georg Thieme Verlag, 1998, pages 180 and 181, "Iron
blue pigments" to "black iron oxide", pages 451 to 453, "pigments"
to "pigment volume concentration", page 563, "thioindigo pigments",
page 567, "titanium dioxide pigments", pages 400 and 467,
"naturally occurring pigments", page 459, "polycyclic pigments",
page 52, "azomethine pigments", "azo pigments", and page 379,
"metal complex pigments".
[0048] Examples of fluorescent pigments (daylight-fluorescent
pigments) are bis(azomethine) pigments.
[0049] Examples of suitable electrically conductive pigments are
titanium dioxide/tin oxide pigments.
[0050] Examples of magnetically shielding pigments are pigments
based on iron oxides or chromium dioxide.
[0051] Examples of suitable metal powders are powders of metals and
metal alloys such as aluminum, zinc, copper, bronze or brass.
[0052] Examples of suitable organic and inorganic fillers are
chalk, calcium sulfates, barium sulfate, silicates such as talc,
mica or kaolin, silicas, oxides such as aluminum hydroxide or
magnesium hydroxide, or organic fillers, such as polymer powders,
especially those of polyamide, polyvinylidene difluoride (PVDF) or
polyacrylonitrile. For further details, refer to Rompp Lexikon
Lacke und Druckfarben, Georg Thieme Verlag, 1998, pages 250 ff.,
"fillers".
[0053] It is preferred to employ mica and talc if the mar
resistance of the color and/or effect layers produced from the
basecoat materials is to be improved.
[0054] It is further of advantage to use mixtures of
platelet-shaped inorganic fillers such as talc or mica and
nonplatelet-shaped inorganic fillers such as chalk, dolomite,
calcium sulfates or barium sulfate, since by this means the
viscosity and rheology may be set very effectively.
[0055] Examples of suitable transparent fillers are those based on
silica, alumina or zirconium oxide.
[0056] Suitable nonoparticles are selected from the group
consisting of hydrophilic and hydrophobic, especially hydrophilic,
nanoparticles based on silica, alumina, zinc oxide and zirconium
oxide and the polyacids and heteropolyacids of transition metals,
preferably of molybdenum and tungsten, having a primary particle
size <50 nm, preferably from 5 to 50 m, in particular from 10 to
30 nm. The hydrophilic nanoparticles preferably have no flatting
effect Particular preference is given to using nanoparticles based
on silica.
[0057] Very particular preference is given to using hydrophilic
pyrogenic silicas whose agglomerates and aggregates have a
chainlike structure and which are preparable by the flame
hydrolysis of silica tetrachloride in an oxyhydrogen flame. They
are sold, for example, by Degussa under the brand name
Aerosil.RTM.. Very particular preference is also given to using
precipitated waterglasses, such as nanohectorites, which are sold,
for example, by Sudchemie under the brand name Optigel.RTM. or by
Laporte under the brand name Laponite.RTM..
[0058] The pigments (1) and (2) present in the component layers (1)
and (2) may be materially identical with or different than one
another.
[0059] According to the process of the invention, a portion or the
total amount of at least one, especially one, basecoat material (A)
is applied to a carrier by means of a directed application
technique (1) in the first step (1).
[0060] The applicator (1) and the carrier are in relative motion
with respect to one another. Preferably, the applicator (1) is
stationary and the carrier is passed under or over, preferably
under, the applicator (1) at a suitable uniform rate of advance,
which depends on the requirements of the case in hand and may be
set easily by the skilled worker.
[0061] In the context of the present invention, a directed
application technique is a technique which gives rise to a certain
orientation or preferential direction with the above-described
pigments in the basecoat layers, which lead to inhomogeneities and
anisotropies in the color and/or effect layers. Secondly, however,
these directed application techniques have the substantial
advantage that they can be used to prepare comparatively thick
layers without problems.
[0062] Examples of suitable directed application techniques are
casting, knife coating, roller coating or extrusion coating. These
techniques may be carried out using customary and known devices,
such as casting devices, knife coaters, rollers, especially
contrarotating rollers, or extruders, especially film
extruders.
[0063] In step (1), preferably the largest part (1) of the color
and/or effect layer (2) is constructed. In other words, the
component layer (1) formed has preferably more than 50%, more
preferably more than 60%, with particular preference more than 65%,
with very particular preference more than 70%, and in particular
more than 75% of the dry film thickness of the color and/or effect
layer.
[0064] In step (1), a portion of the basecoat material (A) is
applied to a carrier. If in step (2) a basecoat material (B) is
applied that is different than the basecoat material (A), the
entirety of the basecoat material (A) may be applied in step
(1).
[0065] The carrier may be permanent or temporary.
[0066] Where a temporary carrier is used, the films of the
invention are peeled off from it following their preparation, after
which they may be used as single-layer films of the invention or
may be joined with other layers or films to form multilayer films
of the invention.
[0067] The temporary carriers may comprise circulating metal belts
or plastic belts or temporary carrier films, which may have been
provided with a release layer.
[0068] Examples of suitable temporary carrier films, particularly
those based on polyester, are known from the European patent EP 0
352 298 B1, page 7 lines 31 to 49.
[0069] Where a permanent carrier is used, the films of the
invention remain firmly joined to it following their
preparation.
[0070] Preferably, the permanent carriers comprise polymer films
which take on a technical function in the films of the invention.
Preferably, the polymer films comprise clearcoat films, adhesion
films or comparatively thick, thermoformable carrier films, such as
are known, for example, from the European patent EP 0 352 298 B1,
page 7 line 54 to page 10 line 51 and page 12 line 55 to page 13
line 53, or from the American patent U.S. Pat. No. 4,810,540 A,
column 3 line 37 to column 5 line 15. Preferably, the polymer films
used as permanent carriers are thermoplastic. They may be solid or
they may be not yet fully solidified and may solidify only after
the application of the component layer (1) or of the color and/or
effect layer (2), thereby resulting in a particularly high level of
interlayer adhesion in the assembly. The polymer films may also be
pigmented, especially for adjustment toward the brightness of the
color and/or effect layer (2).
[0071] After the end of step (1) in the process of the invention,
in step (2) the remainder of the basecoat material (A) and/or the
basecoat material (B), which is different than the basecoat
material (A), is applied to the component layer (1). Preferably in
step (2), the remainder of the basecoat material (A) is
applied.
[0072] The basecoat material (A) and/or the basecoat material (B)
is applied continuously once or at least twice.
[0073] Where continuous application once is employed, the color
and/or effect layer is constructed completely in the first and only
step (2).
[0074] Where continuous application at least twice is employed, the
color and/or effect layer is built up further in the first step
(2), to give an assembly comprising carrier, component layer (1)
and first component layer (2). Complete construction then takes
place in at least one further step (2).
[0075] In step (2), at least one application technique (2) is
employed which gives rise in the resulting component layer (2) to
no arrangement of the above-described pigments in a preferential
direction, i.e., an anisotropy.
[0076] In accordance with a first preferred variant of the process
of the invention, the step or steps (2) is or are carried out in
time directly after the step (1), i.e., simultaneously with step
(1).
[0077] In accordance with a second preferred variant of the process
of the invention, the step or steps (2) are carried out in time
later after the step (1) of the invention, i.e., sequentially. In
this case, the component layer (1) may be dried or partly or fully
cured. Preferably, the assembly composed of carrier and component
layer (1) is wound up onto rolls and stored in this form until step
(2) is implemented. In this case it is of advantage to apply a
release layer, preferably a release film, to the component layer
(1).
[0078] Between the two steps (1) and (2), the component layer (1)
is preferably vented.
[0079] This is preferably brought about by providing, in the case
of the simultaneous variant of the process of the invention, for a
greater or lesser physical distance to prevail between the
applicator (1) of step (1) and the applicator(s) (2) of the step or
steps (2). The physical distance is guided by the evaporation
characteristics of the component layer (1) and may therefore be set
by the skilled worker on the basis of his or her general knowledge
in the art, where appropriate with the assistance of simple
rangefinding tests.
[0080] In the case of the sequential variant of the process of the
invention, venting is preferably brought about by providing a
greater or lesser temporal distance between step (1) and step (2)
or the first step (2). The temporal distance is also guided by the
evaporation characteristics of the component layer (1) and may
therefore be set by the skilled worker on the basis of his or her
general knowledge in the art, where appropriate with the assistance
of simple rangefinding tests.
[0081] Overall it is advantageous if, after venting, the component
layer (1) has still not fully dried but instead still has a certain
residual moisture and/or organic solvent content.
[0082] In step (2), the basecoat materials (A) and/or (B) are
applied continuously by at least one application technique (2) to
the component layer (1) produced in step (1). The application
technique (2) does not give rise to an arrangement of the
above-described pigments in a preferential direction in the
resulting component layer (2); in other words, the pigments are
isotropically distributed. At the time of application, the
applicator(s) (2) and the carrier with the component layer (1) and
also, where appropriate, with the first component layer (2) are in
relative motion with respect to one another. The assemblies
comprising carrier and component layer (1) and also, where
appropriate, first component layer (2) may be passed in relative
motion under or over, preferably under, the applicator(s) (2).
[0083] The application of the basecoat materials (A) and/or (B) may
take place once, to give the complete color and/or effect layer.
Alternatively, the application may take place at least twice, i.e.,
in at least two component steps (2): in this case, the color and/or
effect layer is built up further in the first component step (2)
and its construction is concluded in at least one further component
step (2).
[0084] The application of at least one further component layer (2)
may be carried out simultaneously or sequentially. If it is carried
out sequentially, the assembly comprising carrier, component layer
(1) and first component layer (2) is preferably wound up onto rolls
for storage until the second component step (2) is carried out.
[0085] Preferably, the application techniques (2) are spray
application techniques and the applicators (2) are spray
applicators. The applicators may be pneumatic sprayers (2) (cf.
Rompp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,
Stuttgart, N.Y., 1998, page 165, "compressed air spraying") or
electrostatic sprayers (2) (cf. Rompp Lexikon Lacke und
Druckfarben, Georg Thieme Verlag, Stuttgart, N.Y., 1998, page 186:
"electrostatic coating", page 187: "electrostatic spray guns",
"electrostatic spraying").
[0086] With the simultaneous application of component layer (1) and
component layer (2) or of the first component layer (2), the
applicator(s) (2) is or are disposed directly downstream of the
applicator(s) (1). In the case of sequential application, the
applicator(s) (2) is or are preferably part(s) of a further unit to
which the assemblies comprising carrier and component layer (1) and
also, where appropriate, first component layer (2) are supplied,
preferably in the form of wound-up rolls.
[0087] Irrespective of which variant of the process of the
invention is carried out, the applicator(s) (2) may be stationary.
Preferably, they span in their entire width the assemblies
comprising carrier and component layer (1) and also, where
appropriate, first component layer (2). They may be arranged
transversely to the direction of motion or at an oblique angle to
it. The angle between the edge of an assembly and the main axis of
an applicator (2) may be obtuse to acute.
[0088] Where at least two applicators (2) are used, they may be
arranged in series. In this case, they may stand parallel to or
oblique to one another. Alternatively, the at least two applicators
(2) may intersect at obtuse to acute angles.
[0089] Preferably, one stationary applicator (2) comprises at least
two devices for applying the basecoat materials (A) or (B), in
particular at least two pneumatically or electrostatically operated
spraying heads each with at least one spray nozzle.
[0090] Alternatively, the applicator(s) (2) may be disposed in such
a way as to be movable back and forward transversely and/or
obliquely to the direction of motion of the assemblies comprising
carrier and component layer (1) and also, where appropriate, first
component layer (2). The movable applicators (2) preferably
comprise at least one device for applying the basecoat materials
(A) or (B), in particular at least one pneumatically or
electrostatically operating spraying head each with at least one
spray nozzle.
[0091] In the context of the process of the invention, the
stationary and movable applicators (2) may be combined with one
another. Further more, they may be movable in the vertical
plane.
[0092] By means of the applicators (2), the basecoat materials (A)
and/or (B) may be applied at right angles or obliquely, at an acute
to obtuse angle, with respect to the plane of the assembly
comprising carrier and component layer (1) and also, where
appropriate, first component layer (2). They may be applied in or
against the direction of motion of the assembly. In the context of
the process of the invention, these measures may be combined with
one another.
[0093] The basecoat spray jets produced by the spray applicators
(2) used with preference may overlap. If so, their areas of
impingement may partly or fully coincide. The overlap may be
achieved, for example, by spraying at least two basecoat spray jets
against one another under an acute to obtuse angle. Alternatively,
overlapping basecoat spray jets may be produced with the aid of
spraying heads which comprise at least two spray nozzles in concave
or convex arrangement, such as are known, for example, from the
patent applications and patents DE 195 38 340 A1, WO 97/14506, U.S.
Pat. No. 4,378,386 A or U.S. Pat. No. 5,366,162 A.
[0094] In many cases, the isotropy of the component layers (2) may
be improved further if the pneumatically generated spray jets--or,
to be more precise, the spray jet clouds generated--are set in
periodic--that is, regularly repeating--motion relative to the
spraying direction and relative to the component layer (1).
[0095] In this context, any desired periodic motions of the spray
jet cloud may be considered. Examples of highly suitable periodic
motions are
[0096] the circular or eccentric rotation of the spray jet cloud
about its direction of propagation, resulting in a helical
propagation of the coating material,
[0097] the wave-form propagation of the coating material, in the
form of a sinusoidal wave, for example, or
[0098] the pulsating propagation of the coating material, where in
the spray jet cloud, as viewed in the direction of spraying, areas
rich in coating material alternate periodically with areas low in
coating material.
[0099] These periodic motions may be combined with one another as
desired in such a way that at least two of them are superposed.
[0100] In order to generate these periodic motions, the customary
and known devices for compressed air spraying, particularly the
spray guns, are modified appropriately by equipping them with
movable spray nozzles. Accordingly, preference is given to using
rotating spray nozzles, spray nozzles which move backward and
forward periodically as viewed in the direction of spraying, or
spray nozzles in eccentric disks. For purposes of the superposition
of forms of motion, construction principles may be combined with
one another appropriately. For example, rotating spray nozzles may
be mounted in such a way that they may also be moved backward and
forward periodically. The construction of these spray guns has no
special features; instead, the construction principles, materials,
and measurement and control techniques employed are those which are
customary and known in the field of moving spray nozzles.
[0101] The frequency, the rate and/or the spatial extent or
deflection of the periodic motion which is imposed in accordance
with the invention on the propagating spray jet cloud may vary very
widely and is guided by the requirements of the case in hand. The
skilled worker is able to determine those conditions which are
optimum in each case, where appropriate by means of simple
preliminary tests.
[0102] By means of step or steps (2), the color and/or effect layer
is fully constructed. Its wet layer thickness may vary widely and
is guided in particular by the dry layer thickness which ensures
sufficient hiding power of the color and/or effect layer in the
coating of the invention. In the case in hand, therefore, the
skilled worker is able to determine the appropriate wet layer
thickness on the basis of his or her general knowledge of the art,
where appropriate with the assistance of simple preliminary
tests.
[0103] Subsequently, the color and/or effect layer is dried or
partly or fully cured. Preferably, it is dried. Drying may be
carried out using customary and known methods, such as irradiation
with IR or microwave radiation or treatment with hot air in
countercurrent.
[0104] After drying, the resulting films of the invention may be
wound up onto rolls before being used further.
[0105] Where the films of the invention comprise the
above-described clearcoat films as permanent carriers, their color
and/or effect layers may be provided, on their side facing away
from the clearcoat film, with one of the above-described,
comparatively thick, thermoformable carrier films and/or an
adhesion film before they are used to produce coatings.
[0106] Where the films of the invention already comprise the
above-described, comparatively thick, thermoformable carrier films
as permanent carriers, their color and/or effect layers may be
provided, on their side facing away from the thermoformable carrier
film, with one of the above-described clearcoat films or with a
clearcoat, before they are used to produce coatings. Between the
color and/or effect layer and the clearcoat there may also be an
adjustment layer, as described, for example, in the European patent
application EP 0 949 120 A1.
[0107] The film of the invention may also, however, have a
structure which corresponds to that of the customary and known
automotive finish, comprising electrocoat or anticorrosion layer,
(where appropriate) primer-surfacer coat or antistonechip primer
coat, basecoat, and clearcoat (automobile structure).
[0108] Suitable clearcoat materials for producing the clearcoats
include all customary and known one-component(1K),
two-component(2K) or multicomponent(3K, 4K) clearcoat materials,
powder clearcoat materials, powder slurry clearcoat materials or
UV-curable clearcoat materials.
[0109] Thermally curable one-component(1K), two-component(2K) or
multicomponent(3K, 4K) clearcoat materials are known from the
European patent applications DE 42 04 518 A1, 0 594 068 A1, 0 594
071 A1, 0 594 142 A1, 0 604 992 A1 or 0 596 460 A1, the
international patent applications WO 94/10211, WO 94/10212, WO
94/10213, WO 94/22969 or WO 92/22615 or the American patents U.S.
Pat. Nos. 5,474,811 A, 5,356,669 A or 5,605,965 A.
[0110] One-component(1K) clearcoat materials include, as is known,
hydroxyl-containing binders and crosslinking agents such as blocked
polyisocyanates, tris(alkoxy-carbonylamino)triazines and/or amino
resins. In another variant, they comprise, as binders, polymers
containing pendant carbamate and/or allophanate groups, and
carbamate- and/or allophanate-modified amino resin crosslinking
agents (cf. the American patents U.S. Pat. No. 5,474,811 A,
5,356,669 A or 5,605,965 A1, the international patent applications
WO 94/10211, WO 94/10212 or WO 94/10213, or the European patent
applications EP 0 594 068 A1, 0 594 071 A1 or 0 594 142 A1).
[0111] Two-component(2K) or multicomponent(3K, 4K) clearcoat
materials comprise as essential constituents, as is known,
hydroxyl-containing binders and polyisocyanate crosslinking agents,
which are stored separately until they are used.
[0112] Thermally curable powder clearcoat materials are known, for
example, from the German patent application DE 42 22 194 A1, the
BASF Lacke+Farben AG product information literature "Pulverlacke"
[powder coating materials], 1990, or the BASF Coatings AG brochure
"Pulverlacke, Pulverlacke fur industrielle Anwendungen" [powder
coating materials, powder coatings for industrial applications],
January 2000.
[0113] The familiar essential constituents of powder clearcoat
materials include binders containing epoxide groups, and
polycarboxylic acid crosslinking agents.
[0114] Examples of suitable powder slurry clearcoat materials are
known from the U.S. Pat. No. 4,268,542 A1 and from the patent
applications DE 195 40 977 A1, DE 195 18 392 A1, DE 196 17 086 A1,
DE 196 13 547 A1, EP 0 652 264 A1, DE 196 18 657 A1, DE 196 52 813
A1, DE 196 17 086 A1 or DE 198 14 471 A1 .
[0115] Powder slurry clearcoat materials contain, as is known,
powder clearcoat materials in dispersion in an aqueous medium.
[0116] Clearcoat materials, powder clearcoat materials, and powder
slurry clearcoat materials that are curable with actinic radiation
are disclosed, for example, by the European patent applications EP
0 928 800 A1, EP 0 636 669 A1, EP 0 410 242 A1, EP 0 783 534 A1, EP
0 650 978 A1, EP 0 650 979 A1, EP 0 650 985 A1, EP 0 540 884 A1, EP
0 568 967 A1, EP 0 054 505 A1 or EP 0 002 866 A1, the German patent
applications DE 198 35 206 A1, DE 197 09 467 A1, DE 42 03 278 A1,
DE 33 16 593 A1, DE 38 36 370 A1, DE 24 36 186 A1 or DE 20 03 579
B1, the international patent applications WO 97/46549 or WO
99/14254, or the American patents U.S. Pat. No. 5,824,373 A, U.S.
Pat. No. 4,675,234 A, U.S. Pat. No. 4,634,602 A, U.S. Pat. No.
4,424,252 A, U.S. Pat. No. 4,208,313 A, U.S. Pat. No. 4,163,810 A,
U.S. Pat. No. 4,129,488 A, U.S. Pat. No. 4,064,161 or U.S. Pat. No.
3,974,303 A.
[0117] Clearcoat materials, powder clearcoat materials, and powder
slurry clearcoat materials that are curable thermally and with
actinic radiation are disclosed, for example, by the patent
applications DE 198 18 735 A1, WO 98/40170, DE199 08 013 A1, DE199
08 018 A1, EP0 844 286 A1 or EP0 928 800 A1.
[0118] In general, the clearcoat materials are applied in a wet
film thickness such that curing thereof results in clearcoats
having the thicknesses which are advantageous and necessary for
their functions. These thicknesses are preferably from 10 to 100
.mu.m, more preferably from 15 to 80 .mu.m, with particular
preference from 20 to 75 .mu.m, and in particular from 25 to 70
.mu.m.
[0119] Following application, the color and/or effect layers (2)
are cured together with the clearcoat layers, thermally or both
thermally and with actinic radiation.
[0120] Curing may take place after a certain rest period or
flash-off time. This may have a duration of from 30 s to 2 h,
preferably from 1 min to 1 h, and in particular from 1 min to 45
min. The rest period is used, for example, for the leveling and
devolatilization of the layers and for the evaporation of volatile
constituents such as any water and/or solvent still present.
[0121] Curing with actinic radiation is preferably carried out
using a dose of from 1000 to 2000, more preferably from 1100 to
1900, with particular preference from 1200 to 1800, with very
particular preference from 1300 to 1700, and in particular from
1400 to 1600 mJ/cm.sup.2. If desired, this curing may be
supplemented by actinic radiation from other radiation sources. In
the case of electron beams, it is preferred to operate under an
inert gas atmosphere. This may be ensured, for example, by
supplying carbon dioxide and/or nitrogen directly to the surface of
the clearcoat layer. In the case of curing with UV radiation it is
also possible to operate under inert gas in order to prevent the
formation of ozone.
[0122] Curing with actinic radiation is carried out using the
customary and known radiation sources and optical auxiliary
measures. Examples of suitable radiation sources are flashlamps
from the company VISIT, high or low pressure mercury vapor lamps,
which may have been doped with lead in order to open up a radiation
window up to 405 nm, or electron beam sources.
[0123] The thermal curing also has no special features as to its
method but instead takes place in accordance with the customary and
known methods such as heating in a forced air oven in
countercurrent or irradiation using IR and/or NIR lamps.
Advantageously, thermal curing is effected at temperatures above
90.degree. C. The maximum curing temperatures are dependent on the
heat distortion resistance of the carrier or of the carrier
film.
[0124] The films of the invention, especially those prepared by the
process of the invention, comprise or consist of
[0125] (1) at least one, especially one, component layer (1)
comprising at least one color and/or effect pigment (1) in
anisotropic distribution, and
[0126] (2) at least one, especially one, component layer (2)
comprising the pigment or pigments (1) and/or at least one
different color and/or effect pigment (2) in isotropic
distribution.
[0127] The films of the invention are outstandingly suitable for
producing decorative and/or protective coatings on motor vehicle
bodies and parts thereof, the interior and exterior of motor
vehicles, the inside and outside of buildings, doors, windows, and
furniture, and also in the context of the industrial coating of
small parts, coils, containers, packaging, electrical components,
and white goods.
[0128] In particular they are outstandingly suitable, owing to
[0129] their isotropic flop behavior and their isotropic color
locus, both of which are independent of the viewing angle, so that
their processing into coatings for three-dimensional articles is no
longer accompanied by any logistical problems or large amounts of
offcuts,
[0130] the high hiding power, even in the extended areas, of the
coatings of the invention produced from the films of the invention,
and
[0131] their other outstanding profile of performance properties,
which, as regards gloss, distinctiveness of image, uniformity of
hiding ability, uniformity of film thickness, resistance to motor
fuel, solvents and acids, hardness, abrasion resistance, mar
resistance, impact strength, adhesion, weathering stability, and
resistance to water and moisture, exhibits the so-called
"automotive quality", as a replacement for the conventional
multicoat color and/or effect basecoat/clearcoat system of coating
motor vehicle bodies and parts thereof.
[0132] The production of the coatings of the invention on the
three-dimensional articles, especially on motor vehicle bodies, has
no special features as to its method but instead may be carried out
by means of the customary techniques and apparatus such as are
known, for example, from the American patents U.S. Pat. No.
4,810,540 A, U.S. Pat. No. 4,931,324 A or U.S. Pat. No. 5,114,789 A
or the European patents EP 0 266 109 B1, EP0 285 071 B1, EP0 352
298 B1 or EP0 449 982 B1.
EXAMPLES 1 (INVENTIVE) AND C1 AND C2 (COMPARATIVE)
THE PREPARATION OF AN INVENTIVE FILM (EXAMPLE 2) AND OF TWO
NONINVENTIVE FILMS (EXAMPLE C1 AND C2)
EXAMPLE 1
[0133] In Example 1, the permanent carrier used was a 300 .mu.m
thermoplastic ABS monofilm. On a continuous film coating unit, the
film was coated on one side with a metallic aqueous basecoat
material (color: "silver metallic") using a blade coater. The
parameters set were as follows:
1 Solids content of the aqueous basecoat 19% by weight; material:
Viscosity of the aqueous basecoat 200 mPas material: (shear rate:
50 s.sup.-1); Rate of advance of the film: 1 m/min; Wet layer
thickness: 200 .mu.m.
[0134] After passing through a 2 m evaporation section, the
resulting wet layer was overcoated with the same aqueous basecoat
material. This was done using a pneumatic spray gun (Devilbiss.RTM.
AGG-511) which was moved backward and forward across the film web
transversely to the direction of advance of the film. The
parameters set were as follows:
[0135] Flow rate: 380 cm.sup.3/min;
[0136] Atomizer air pressure: 5 bar;
[0137] Nozzle/film distance: 50 cm;
[0138] Rate of advance: 1 m/min.
[0139] The resulting wet layer was dried thermally using hot air
(120.degree. C. upon entry of the air) in a 3 m nozzle tunnel. The
resulting film of the invention was wound up onto a roll.
[0140] To determine the colorimetric data, specimens cut from the
film of the invention were overcoated with a solventborne
two-component clearcoat material from BASF Coatings AG. The
resulting clearcoat layers were cured together with the effect
layers at 120.degree. C. for 30 minutes. The clearcoats had a dry
thickness of 35 .mu.m.
EXAMPLE C1
[0141] Example 1 was repeated except that the wet layer produced in
the first step was not overcoated with the aqueous basecoat
material.
EXAMPLE C2
[0142] Example 1 was repeated, but only one aqueous basecoat layer
was applied by spray application.
[0143] The table gives an overview of the construction of the film
of the invention and of the noninventive films.
2TABLE The construction of the inventive film (Example 1) and of
the noninventive films (Examples C1 and C2) Examples 1 C1 C2 Layer
(.mu.m) (.mu.m) (.mu.m) Basecoat: Dry layer thickness: Cast layer
40 40 -- Sprayed layer 10 -- 20 Total layer 50 40 20 Clearcoat: 35
35 35
[0144] The colorimetric data of the films were measured using an
X-Rite Smartscan, the measurement method employed being the
"metallic paint" method.
[0145] Colorimetric evaluation showed that in terms of color,
brightness and flop characteristics, the films of the invention
prepared by the process of the invention were fully in accordance
with a multicoat automotive OEM finish produced purely by spray
application (Example C2). In particular, no strong anisotropies in
brightness were observed, which dominate the visual perception in
comparison to the color information. However, the coating produced
from the noninventive film of Example C2 did not have the necessary
hiding power in the extended areas. The noninventive film of
Example C1 exhibited severe anisotropies in brightness and in
metallic effect, which did not permit its use as a substitute for a
conventional automotive OEM finish. In contrast, the inventive
films of Example 1 represented a fully equivalent replacement for
the automotive OEM finishes of the basecoat/clearcoat type produced
by spray application.
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