U.S. patent application number 13/521824 was filed with the patent office on 2013-02-14 for method for producing a pane with a patterned surface, and pane having a patterned surface.
This patent application is currently assigned to SCHOTT AG. The applicant listed for this patent is Andrea Anton, Matthias Bockmeyer, Oliver Gros, Inka Henze, Eveline Rudigier-Voigt, Joerg Schuhmacher, Jochen Settelein, Stefan Spengler, Claudia Stolz, Tamara Sweeck. Invention is credited to Andrea Anton, Matthias Bockmeyer, Oliver Gros, Inka Henze, Eveline Rudigier-Voigt, Joerg Schuhmacher, Jochen Settelein, Stefan Spengler, Claudia Stolz, Tamara Sweeck.
Application Number | 20130040116 13/521824 |
Document ID | / |
Family ID | 44072736 |
Filed Date | 2013-02-14 |
United States Patent
Application |
20130040116 |
Kind Code |
A1 |
Henze; Inka ; et
al. |
February 14, 2013 |
METHOD FOR PRODUCING A PANE WITH A PATTERNED SURFACE, AND PANE
HAVING A PATTERNED SURFACE
Abstract
A method for producing a pane of a household appliance or a
viewing window of an oven is provided. The method includes the
steps of: providing a substrate; applying a sol-gel layer to the
substrate; embossing a haptically perceptible pattern using an
embossing tool in the sol-gel layer; and curing the sol-gel layer.
A pane of a household appliance or piece of furniture is also
provided that includes a glass or glass-ceramic substrate with a
patterned sol-gel layer which has a haptically perceptible
pattern.
Inventors: |
Henze; Inka; (Nieder-Olm,
DE) ; Spengler; Stefan; (Budenheim, DE) ;
Bockmeyer; Matthias; (Mainz, DE) ; Rudigier-Voigt;
Eveline; (Mainz, DE) ; Schuhmacher; Joerg;
(Kornwestheim, DE) ; Stolz; Claudia; (Inglesheim,
DE) ; Anton; Andrea; (Hueffelsheim, DE) ;
Settelein; Jochen; (Wuerzburg, DE) ; Sweeck;
Tamara; (Bad Muenster, DE) ; Gros; Oliver;
(Rheinboellen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Henze; Inka
Spengler; Stefan
Bockmeyer; Matthias
Rudigier-Voigt; Eveline
Schuhmacher; Joerg
Stolz; Claudia
Anton; Andrea
Settelein; Jochen
Sweeck; Tamara
Gros; Oliver |
Nieder-Olm
Budenheim
Mainz
Mainz
Kornwestheim
Inglesheim
Hueffelsheim
Wuerzburg
Bad Muenster
Rheinboellen |
|
DE
DE
DE
DE
DE
DE
DE
DE
DE
DE |
|
|
Assignee: |
SCHOTT AG
Mainz
DE
|
Family ID: |
44072736 |
Appl. No.: |
13/521824 |
Filed: |
January 14, 2011 |
PCT Filed: |
January 14, 2011 |
PCT NO: |
PCT/EP2011/000142 |
371 Date: |
October 8, 2012 |
Current U.S.
Class: |
428/201 ;
427/162; 427/164; 427/165; 428/206; 428/210 |
Current CPC
Class: |
Y10T 428/24851 20150115;
C03C 17/3686 20130101; Y10T 428/24893 20150115; C03C 17/3649
20130101; C03C 2217/45 20130101; C03C 17/3684 20130101; C03C 1/008
20130101; C03C 2217/485 20130101; Y10T 428/24926 20150115; Y10T
428/24355 20150115; C03C 2217/72 20130101; Y10T 428/24545 20150115;
C03C 2217/465 20130101; B44F 7/00 20130101; C03C 17/3636 20130101;
C03C 17/3607 20130101; C03C 2217/77 20130101; C03C 2217/478
20130101 |
Class at
Publication: |
428/201 ;
427/162; 427/164; 427/165; 428/210; 428/206 |
International
Class: |
C03C 17/00 20060101
C03C017/00; B32B 5/16 20060101 B32B005/16; B32B 33/00 20060101
B32B033/00; B32B 17/06 20060101 B32B017/06; B05D 5/06 20060101
B05D005/06; B05D 3/02 20060101 B05D003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 14, 2010 |
DE |
10 2010 004 741.4 |
Claims
1-23. (canceled)
24. A method for producing a pane of a household appliance or a
viewing window of an oven, comprising the steps of: providing a
substrate; applying a sol-gel layer to the substrate; embossing a
haptically perceptible pattern using an embossing tool in the
sol-gel layer; and curing the sol-gel layer.
25. The method as claimed in claim 24, further comprising molding
the haptically perceptible pattern from a master to form the
embossing tool.
26. The method as claimed in claim 24, wherein the step of applying
the sol-gel layer to the substrate comprises coating only sections
of the substrate with the sol-gel layer.
27. The method as claimed in claim 24, further comprising embossing
the sol-gel layer with at least a second, different haptically
perceptible pattern.
28. The method as claimed in claim 24, wherein the substrate has a
thickness from 0.5 to 50 mm.
29. The method as claimed in claim 24, wherein curing the sol-gel
layer comprises burning off organic constituents of the sol-gel
layer.
30. The method as claimed in claim 24, further comprising adding
coloring particles to the sol-gel.
31. The method as claimed in claim 24, wherein the haptically
perceptible pattern is embossed regularly, at least in sections,
and has a pitch from 0.1 .mu.m to 10 mm.
32. The method as claimed in claim 24, wherein the step of
providing the substrate comprises providing a transparent
substrate.
33. The method as claimed in claim 24, wherein the step of
providing the substrate comprises providing a glass or glass
ceramic substrate.
34. The method as claimed in claim 24, wherein the step of applying
the sol-gel layer comprises screen printing or inkjet printing the
sol-gel layer.
35. A pane of a household appliance or piece of furniture,
comprising a glass or glass-ceramic substrate with a patterned
sol-gel layer which has a haptically perceptible pattern.
36. The pane as claimed in claim 35, wherein organic constituents
of the sol-gel layer have been burned off.
37. The pane as claimed in claim 35, wherein the pane is a control
panel.
38. The pane as claimed in claim 35, wherein the sol-gel layer is
dyed.
39. The pane as claimed in claim 35, wherein the haptically
perceptible pattern has a pattern depth that ranges from 50 nm to 1
mm.
40. The pane as claimed in claim 35, further comprising at least
one further layer disposed on the sol-gel layer.
41. The pane as claimed in claim 40, wherein the at least one
further layer comprises a lacquer layer or a metal layer disposed
on the sol-gel layer.
42. The pane as claimed in claim 35, wherein the sol-gel layer
comprises particles for matting the layer.
43. The pane as claimed in claim 35, wherein the sol-gel layer has
a texture of an etched surface.
44. The pane as claimed in claim 35, wherein the pane is a
thermally tempered pane.
45. The pane as claimed in claim 35, further comprising at least
one transparent section and at least one opaque section.
46. The pane as claimed in claim 35, wherein the sol-gel layer is
colored or opaque.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a method for producing a pane, in
particular a pane for a household appliance or a viewing window for
an oven or an architectural glass. Furthermore, the invention
relates to such a pane.
BACKGROUND OF THE INVENTION
[0002] Methods for patterning glass surfaces are known. Usually,
glass surfaces are patterned by an etching process using
hydrofluoric acid. This process is complex, dangerous, and the
variety of shapes is limited due to the etching process.
[0003] Furthermore, it is known to emboss films which are for
example glued onto glass. Such a method is shown in DE 199 365 04
A1, for example. However, often such laminated films are prone to
delamination.
[0004] Another possibility is mechanical patterning, for example by
sand blasting. Here again the variety of shapes is limited, and
though matt textures may be produced, it is not possible by a
mechanical process to produce arbitrarily shaped haptically
perceptible patterns, such as for grip surfaces.
[0005] As another alternative, document EP 0 493 202 B1 shows
manufacturing of a patterned glass using a roller which embosses
the pattern into the still viscous glass. However, such a process
usually only allows to obtain a pattern covering the entire
surface. Furthermore, the method is not suitable to produce exact
pattern depths in a range below 500 .mu.m, since due to the
viscosity of the glass a rounding of the embossed shapes
occurs.
OBJECT OF THE INVENTION
[0006] An object of the invention, therefore, is to provide a
method which permits to produce a pane, in particular a pane of a
household appliance or the viewing window of an oven or an
architectural glass with a haptically perceptible pattern in an
simple manner.
[0007] Moreover, the pattern should exhibit good durability.
SUMMARY OF THE INVENTION
[0008] The object of the invention is already achieved by a method
for producing a pane, and by a pane of a household appliance or
piece of furniture according to any of the independent claims.
[0009] Preferred embodiments and refinements of the invention are
set forth in the respective dependent claims.
[0010] The invention, on the one hand, relates to a method for
producing a pane which especially is a part of a household
appliance or a viewing window of an oven. In particular, the pane
is intended for use as a viewing window or control panel for
so-called "white goods" such as cooker extraction hoods, ovens,
steam cookers, microwave ovens, kitchen fronts, splash guards in
kitchens, and small electrical appliances such as toasters, or for
cooktops. But the pane may likewise be provided as a fireplace
viewing window or for architectural glazing applications and
picture framing. It may also be used in elevators, as a door, or in
furniture. Moreover, the pane is intended for building glazing
applications in the interior and outside. In particular it is
intended for use as flooring or wall or ceiling surface or
partition wall, for example in wet areas. Use thereof in the
automotive, shipbuilding or aviation sector, for example as an
instrument panel, or in the field of consumer electronics such as
for mobile phones, computers, monitors, or television sets is also
being considered.
[0011] According to the invention, first a substrate is provided.
Preferably the substrate is transparent.
[0012] For example a glass or glass-ceramic substrate may be used
which is particularly suitable for use at higher temperatures.
[0013] Basically, however, the invention may also be used for
plastic substrates, in particular transparent plastic substrates
such as polycarbonates, polyacrylates, polyolefins, in particular
cyclo-olefin copolymers.
[0014] A sol-gel layer is applied onto the substrate.
[0015] In particular it is intended to apply the sol-gel layer
using a printing technique.
[0016] Particularly suitable are in particular screen printing or
ink jet printing techniques.
[0017] In this way even large surfaces may be coated with a sol-gel
layer in a simple manner.
[0018] However, pad printing, dip coating, roll coating, flow
coating, spraying, slot casting and other liquid coating techniques
are likewise possible.
[0019] It is furthermore envisaged to apply the coating only in
sections of the substrate. For example transparent areas may be
excluded from being coated.
[0020] The invention here benefits from the fact that such a
partial coating which for example may comprise graphic elements,
such as letters, borders, etc. may be applied in a very simple
manner using a printing process, in particular by screen
printing.
[0021] Then, a haptically perceptible pattern is embossed into the
sol-gel layer using an embossing tool.
[0022] The embossing tool can be formed as a stamp or as a roller,
for example.
[0023] A haptically perceptible pattern, in the present context, is
to be understood as a pattern, which due to the spacing of the
individual pattern elements and due to the depth of the pattern can
be felt by a person who touches it and thus clearly differs from a
smooth layer. In particular, anti-slip grip surfaces are
contemplated, or textures of wood, natural stone, and/or regular
geometric shapes such as regular three-dimensional bodies,
especially diamonds, prisms, or cylinders.
[0024] Then the sol-gel layer is cured and forms the surface or at
least the pattern-defining layer within a layer system on the
surface of the substrate.
[0025] Curing of the sol may be accomplished for example by simple
drying, the sol, as the case may be, curing by chemical
reactions.
[0026] It is contemplated to use a pure inorganic precursor,
however, according to another embodiment of the invention hybrid
polymeric materials of colloidal dispersions are likewise
envisaged.
[0027] In one embodiment of the invention, the sol-gel layer may be
fired by a thermal treatment, in particular to produce
temperature-resistant haptic layers. In this case organic
constituents of the sol-gel layer, if present, may be burned out,
at least partially.
[0028] Sol-gel layers may be provided with such a temperature
resistance that they resist a tempering process, for example. As
such, firing of the layer may be accomplished during a tempering
process, for example, so that no further process step is
required.
[0029] One preferred embodiment of the invention contemplates to
produce the pattern of the embossing tool by molding the pattern
from a master. This especially permits to transfer textures of
other materials to a glass or glass ceramic substrate.
[0030] In particular, it is envisaged to transfer etched textures
such as for example those of etched metal or glass to the
substrate.
[0031] In combination with a metallic-looking coating of the
sol-gel layer, or in combination with a colorization of the layer,
or with an addition of in particular metallic particles a
surprising impression of an etched metal pattern may thus be
created on a glass or glass-ceramic substrate, wherein in case an
only partial coating the metallic appearance seamlessly merges into
a transparent pane.
[0032] In a refinement of the invention it is contemplated to
provide a sol-gel layer on a pane which has two different patterns.
So, two areas with a different appearance may be produced in a very
simple way.
[0033] To this end, it is in particular suggested to use two
different stamps. However, it is also possible to provide a
plurality of patterns on one stamp.
[0034] The substrate preferably has a thickness from 0.5 and 10
mm.
[0035] In one embodiment of the invention, coloring and/or opaque
particles, in particular metal particles, are added to the sol-gel
layer, or the sol-gel layer is coated with a further layer,
especially a metallic-looking lacquer or a metal layer.
[0036] In this way, almost any surface appearance in terms of color
and opacity may be provided on a transparent substrate.
[0037] In one preferred embodiment of the invention, a haptically
perceptible pattern which is embossed regularly, at least in
sections, has a pitch from 0.1 .mu.m to 10 mm, preferably from 1
.mu.m to 2 mm. Pitch herein means the space between the center of a
structural element and that of another, similar structural
element.
[0038] In contrast to most etching techniques or to a mechanical
treatment by blasting, the invention permits to provide patterns in
which the individual pattern elements are relatively large and
considerably spaced from one another. So, for example, it is
conceivable to create textures which resemble the surface of carbon
fiber reinforced plastics.
[0039] The composite material producible and in particular produced
according to invention is particularly suitable as a pane of a
household appliance, a piece of furniture, a picture glazing, or an
architectural glass.
[0040] The invention furthermore relates to a pane of a household
appliance or piece of furniture.
[0041] It may for example be formed as a viewing window or a
control panel and comprises a glass or glass-ceramic substrate with
a patterned sol-gel layer which has a haptically perceptible
pattern.
[0042] In particular, the pane has been produced by the method
described above.
[0043] In one embodiment of the invention, organic constituents of
the sol-gel layer have been burned out, so as to achieve better
temperature resistance.
[0044] That is, a sol-gel layer in the context of the invention is
also understood as a layer in which the organic constituents of a
sol, for example a hybrid sol, have been removed.
[0045] The sol-gel layer may be dyed, for example by means of a dye
or by means of coloring particles such as metal or carbon black
particles.
[0046] The pattern depth of the sol-gel layer preferably ranges
from 100 nm to 1 mm in order to produce clearly perceptible haptic
properties of the layer.
[0047] In another embodiment, in addition or as an alternative
thereto a further layer, especially a lacquer layer or metal layer,
is disposed on the sol-gel layer.
[0048] This layer follows the pattern of the sol-gel layer and
provides for the desired opacity, the desired gloss, and/or the
desired color.
[0049] In another embodiment of the invention, the sol-gel layer
comprises particles for matting the layer. By adding larger
particles, in particular particles having a size of more than 100
nm, a matte surface may be obtained in addition to the pattern,
since the surface due to the particles has a roughness which
reduces light reflections.
[0050] In one embodiment of the invention, the pane is designed to
be transparent in sections thereof and simultaneously opaque in
other sections.
[0051] It will be appreciated that these terms should not be
understood literally, but that for example in the coated area the
layer rather may still exhibit a slight transparency, and that for
example the glass substrate rather may be slightly dyed, as might
be the case with a viewing window of an oven.
[0052] In particular it is contemplated to provide the sol-gel
layer in a colored and/or opaque form.
[0053] The invention permits to obtain embossed patterns on rigid
or brittle material, such as glass or glass ceramic, in a simple
manner and with a variety of appearances and haptics.
[0054] However, plastics of all kinds, polymers, metals, etc. may
likewise be coated. Moreover, the invention provides for
temperature resistant, corrosion resistant, non-yellowing, weather
and scratch resistant coatings.
[0055] With reference to the general description above, the
invention will now be described in more detail.
[0056] For manufacturing the stamp a master is used which has the
desired pattern, as mentioned above. For a roughened surface this
may be an appropriately etched surface, and when regular geometric
shapes are desired, this may be a metal structure on which regular
geometric patterns had been provided using an etching process or
mechanical processes, in particular machining, grinding, or sand
blasting.
[0057] The master template is preferably cleaned so as to be free
of grease and lint. A polymer mass is poured onto the clean master
template, in particular a two-component silicone molding compound,
and cured. Curing may be accomplished, for example, by heating.
Especially complex patterns may include bubbles which may be
removed by applying a vacuum. The cured polymer stamps are released
from the master template and are then ready to be used for
embossing purposes.
[0058] After the embossing process the stamps may be cleaned, for
example using an alcohol or alkaline cleaning agents, and may be
reused.
[0059] In another embodiment of the invention, the embossing tool
may be provided in particular in form of a transparent foil on
which a lacquer had been applied which was embossed using a roller
with the corresponding pattern.
[0060] The sol-gel layer may be applied on glass, glass ceramic or
on another substrate using an inexpensive liquid coating
process.
[0061] The sol-gel layer may comprise amorphous and/or crystalline
particles as well as organic/inorganic sol-gel hybrid polymer
particles, as is known in the art.
[0062] By choosing of the composition of the particles, the
refractive index of the sol-gel layer may be adapted to that of the
substrate and/or to that of a layer optionally arranged above. For
example, high or low refractive index particles may be added to the
sol.
[0063] Preferably, the refractive index of the particles ranges
from 1.3 to 2.9, exemplary refractive indices are: for
MgF.sub.2=1.34-1.36, for SiO.sub.2=1.45-1.5, for
Al.sub.2O.sub.3=1.72-1.76, for ZrO.sub.2=2.0-2.2, for
TiO.sub.2=2.4-2.9.
[0064] An advantageous method for applying the sol is screen
printing, in particular for larger substrates. A screen printing
process in particular allows to apply the sol only in sections of
the substrate.
[0065] Thereby, areas which are not to be patterned may be excluded
from being coated, and in free areas which for example serve as a
viewing window or as a display or control panel, an inspection for
layer roughnesses, inhomogeneities, and contaminations may be
dispensed with.
[0066] Optionally, the sol-gel coating may be precured, in
particular in case of hybrid polymers which for example can be
precured using electromagnetic waves such as UV radiation, or by
heat.
[0067] Preferably, the sol-gel layer is embossed using a polymer
stamp, in continuous or static manner. This embossing stamp may
likewise be provided with a sol-gel layer.
[0068] In one embodiment of the invention, the layer is cured under
a defined pressure of the embossing stamp, thermally and/or
photochemically. In particular photochemical curing is envisaged in
which the sol-gel layer is cured through a UV radiation transparent
stamp while still being in contact with the stamp.
[0069] In an alternative embodiment no pressure is required, since
the sol is automatically drawn into the pattern of the stamp. This
may be caused by capillary forces and/or the own weight of the
stamp and may also be a result of the selected viscosity and the
high plasticity of the lacquer. The lacquers preferably exhibit a
low thixotropy which promotes the process of `automatically being
drawn into the pattern`. Furthermore, the lacquers exhibit a rather
Newtonian behavior which means that the shear stress is
proportionally related to the shear rate.
[0070] Typical viscosities of the employed lacquers range from 50
mPas to 2500 mPas, preferably from 75 mPas to 500 mPas, more
preferably from 100 mPas to 300 mPas. All values were determined at
a shear stress of 85 N/m.sup.2.
[0071] In one embodiment of the invention, bubbles are eliminated
either manually, using a roller, or by applying a negative
pressure.
[0072] Upon removal of the embossing stamp a patterned, thin
sol-gel layer is provided which preferably has a thickness from 10
nm to 1 mm, more preferably from 50 nm to 100 .mu.m. The patterns
of this layer are defined by the pattern of the embossing
stamp.
[0073] Possible patterns are both periodic and random patterns, in
particular lines of a brushed surface and/or brushed and/or
emerized and/or polished surface, light-scattering layers, etched
surfaces, punched surfaces, three-dimensional shapes such as
pyramids, inverted pyramids, etc.
[0074] The pattern depth preferably varies in a range from 50 nm to
1 mm, more preferably from 50 nm to 100 .mu.m.
[0075] In the context of the present invention, the pattern of the
sol-gel layer defines the pattern of optional additional layers, in
particular metal layers or metallic shining lacquers, as is the
case in one embodiment of the invention.
[0076] In particular, it is also possible to use a luster color as
an additional layer. Such color usually comprises dissolved metal
resinates which, at higher temperatures, form a thin metal oxide
layer with a colored or metallic appearance.
[0077] Moreover, it is possible to use a lacquer which includes
metal or metal oxide particles.
[0078] The embossability of the layer is adjusted through the
chemical composition of the sol, the degree of hydrolysis, and/or
the pH-value, and/or the content of nanoparticles. Preferably, the
ratio of water to hydrolyzable groups is below 0.5.
[0079] In a preferred embodiment of the invention, the solvent
content of the starting lacquer ranges from 50 to 25 mass-%, more
preferably from 45 to 35 mass-%, in order to ensure screen
printability. Here, the solvent fraction has been determined after
drying at 100.degree. C. for 2 h using IR radiation.
[0080] The embossability of the layer is adjusted through the
chemical composition of the sol and the degree of hydrolysis.
Preferably, the ratio of water to hydrolyzable groups is below
0.5.
[0081] The embossability of the layer may be adjusted via the
proportion of organic functional groups and/or the content of
inorganic nanoparticles and/or the morphology and/or the type of
material of the nanoparticles and/or the pH of the lacquer and/or
the type of shielding or the chemical stabilization of the
nanoparticles.
[0082] In a dried embossable film, the mass ratio of hydrolyzed UV
cross-linkable component and nanoparticles preferably is between
90:10 and 40:60, more preferably between 70:30 and 50:50.
[0083] In case of reactive embossing using UV light, the mass
fraction of UV cross-linking monomers should not be smaller than
10%.
[0084] Generally, however, especially if the layer is fired in a
subsequent process step, the organic content should not be selected
too high, in particular an organic content from 5 to 80 mass-%,
preferably from 10 to 50 mass-% is envisaged.
[0085] In one embodiment, burning out of the organics and layer
compaction result in a reactive bonding to the substrate and/or
formation of a transition zone in which for example an ion exchange
occurred. This contributes to an improved mechanical stability of
the layer and improved adhesion of the layer.
[0086] This transition zone may have a thickness from 0.5 nm to 10
.mu.m, preferably from 5 nm to 500 nm.
[0087] For this purpose, sintering or densification additives may
be added to the embossing lacquer. For glassy layers, these may
include for example ions, salts, alkoxides, and/or metal oxides of
the alkali and/or alkaline earth elements and/or transition
elements.
[0088] In a specific embodiment, such compounds may diffuse from
the substrate into the applied layer and/or may be introduced from
the nanoparticles and/or via a second coating or by
infiltration.
[0089] In one particular embodiment, the embossed layer according
to the invention includes at least two, preferably three or more
different metal cations, for example Si, and/or K, and/or Na,
and/or Mg, and/or Na, and/or Ca, and/or Li, and/or Ba, and/or Zn,
and/or Bi, and/or B, and/or Zr, and/or Ti, and/or Al, and/or
Ce.
[0090] Both gas phase and liquid phase coating techniques may be
used.
[0091] Such layers and/or layer systems preferably exhibit a
scratch resistance of more than 300 g, preferably more than 700 g
in the BSH test. In the pencil hardness test, they preferably
exhibit a hardness of more than 1H, more preferably of more than
3H.
[0092] Depending on the required temperature stability of the final
product, the sol-gel layers may be cured at a temperature from 50
to 1000.degree. C., preferably from 100 to 900.degree. C., most
preferably from 400 to 730.degree. C. The pattern is maintained,
even if the organic components are almost completely burned
out.
[0093] Depending on the curing temperature and the composition of
the sol-gel, the pattern depth may decrease by 0 to 60% as compared
to the master pattern. If necessary, this may be compensated for by
using a master pattern with a greater pattern depth.
[0094] In one preferred embodiment of the invention,
hydrolyzed and condensed epoxy- and/or methacrylate-functionalized,
and/or ally- and/or vinyl-functionalized alkoxysilanes, which are
filled with amorphous and/or crystalline nanoparticles and which
are added as an alcoholic dispersion, are used as a sol-gel
precursor. In this way, shrinking between 0 and 25% may be
achieved.
[0095] In one particularly preferred embodiment of the invention,
irregularly shaped fibrous particles are used, especially SiO.sub.2
particles, in particular with a diameter from 5 to 15 nm and a
length from 5 to 150 nm. Other embodiments use mixtures of
spherical particles of different sizes ranging from 5 to 125
nm.
[0096] Such fibrous particles are obtained, for example, by
stringing together individual spherical particles.
[0097] Alternatively, fibrous or spherical particles of SiO.sub.2,
SiO.sub.yNa.sub.xK.sub.z, SiO.sub.xB.sub.yK.sub.z, TiO.sub.2,
ZrO.sub.2, C, Si, ZnO, Al.sub.2O.sub.3, or CeO.sub.2
may be used.
[0098] Especially the mechanical strength of the patterned layer
may be adjusted via the chemical composition of the inorganic
constituents (molecularly disperse sol-gel components and inorganic
nanoparticles).
[0099] Preferred materials are those that are sintered easily. For
this purpose, both amorphous and crystalline compositions of
molecularly dispersed silicon oxide in the sol-gel precursor and
crystalline and/or amorphous inorganic nanoparticles may be
used.
[0100] By proper choice of the sol-gel precursor, a composition may
be adjusted which corresponds to a low temperature sintered
multicomponent glass, such as for example used for enamel
coatings.
[0101] For further modification of the haptics, in particular to
achieve a velvety effect to the touch, for example amorphous,
substantially spherical silicon oxide nanoparticles with a mean
particle size from 300 to 600 nm or platelet-shaped inorganic
particles or irregularly shaped particles with an mean size from
100 to 1000 nm may be used. These particles may be produced by
flame pyrolysis, for example.
[0102] In another embodiment of the invention, the patterned
sol-gel layer has an intrinsic color, for example due to absorption
or due to interference effects. Absorption may be adjusted through
the choice of the molecularly dispersed sol-gel precursor and/or by
adding absorbent nanoparticles or pigments. In particular inorganic
nanoparticles absorbing in the visible and/or infrared wavelength
range may be used, such as CuO, Co.sub.2O.sub.3, C, TiC, ZrC, TiN,
ZrN, Ag, Al, Fe.sub.2O.sub.3, SiN, BN.
[0103] The thickness of the sol-gel layer preferably ranges from
0.05 to 3 .mu.m. The layer material preferably comprises amorphous
or hybrid polymeric silicon oxide, optionally with fractions of
amorphous or nanocrystalline oxide and/or non-oxide metal compounds
such as TiO.sub.2, MgF.sub.2, MgO.sub.xF.sub.y, CaF.sub.2,
CaO.sub.xF.sub.y, CaO, K.sub.2O, MgO, Li.sub.2O, Na.sub.2O,
ZrO.sub.2, Yttrium-stabilized ZrO.sub.2, Ca-stabilized ZrO.sub.2,
Mg-stabilized ZrO.sub.2, Ce-stabilized ZrO.sub.2, Si-stabilized
ZrO.sub.2, Al.sub.2O.sub.3, CeO.sub.2, Gd.sub.2O.sub.3,
Bi.sub.2O.sub.3, B.sub.2O.sub.3, ZnO, ITO, SiN, SiON, SiC, SiOC,
TiN, TiC, TiON, TiOC, ZrC, ZrN, ZrON, ZrOC and/or hybrid polymeric
derivatives thereof or compounds of the particles.
[0104] The coating solution may comprise amorphous or crystalline
molecularly or colloidally dispersed or hybrid polymeric sol-gel
precursors of silicon, titanium, boron, bismuth, sodium, lithium,
potassium, calcium, zirconium, phosphorus, niobium, hafnium,
yttrium, aluminum, zinc, magnesium, tin (e.g. SiOR.sub.xR.sub.y,
TiOR.sub.xX.sub.y, ZrOR.sub.xX.sub.y, AlOR.sub.xX.sub.y,
ZnOR.sub.xX.sub.y, MgOR.sub.xX.sub.y, CaOR.sub.xX.sub.y,
SnOR.sub.xX.sub.y, NaOR, KOR, BOR.sub.3, MgOR.sub.2). The particles
in the sol-gel precursor preferably have a particle size ranging
from of 0.05 to 200 nm, more preferably from 1 to 100 nm.
[0105] A preferred embodiment of the invention comprises UV light
curable hybrid polymers, in particular in form of a hydrolyzed and
condensed alkoxysilane precursor, such as
glycidyloxypropyltriethoxysilane,
glycidyloxypropyltrimethoxysilane, methacryloxytrimethoxysilane,
methacryloxytriethoxysilane, allylsilane, vinylsilane.
[0106] This precursor constitutes the binder for silicon oxide
nanoparticles which are added to the sol. Preferably, silicon oxide
nanoparticles are used which are fixed with a sol whose degree of
condensation is greater than 60%. Preferably, the volume fraction
of the silicon oxide nanoparticles is greater than 20%, more
preferably greater than 40%.
[0107] When thermally treated at temperatures above 200.degree. C.,
such a layer exhibits a micro- or mesoporosity. The porosity may
range from 1 to 50% (open porosity). A temperature treatment at
500.degree. C. results in pores with a pore diameter from 0.4 to 15
nm. These pores preferably have a bottleneck-shaped geometry and
are distinguished by a pore diameter that is larger than the pore
outlet or the connection of the pores. In a preferred embodiment of
the invention, the pore diameter ranges from 3 to 10 nm, and the
size of the pore outlet ranges from 1 to 6 nm.
[0108] In one embodiment of the invention, a methacrylic acid
complexed sol-gel precursor may be used as the UV-crosslinking
component, in particular titanium alkoxide and/or zirconium
alkoxide, reacted with methacrylic acid.
[0109] For producing a screen-printable lacquer system, sol-gel
precursors with a low solvent content are preferably used.
Preferred solvents exhibit a vapor pressure of less than 2 bars, an
evaporation number of more than 35, and/or a boiling point above
120.degree. C.
[0110] For example, when producing the sol-gel precursor a solvent
exchange of highly volatile alcohols may be accomplished for
ethylene glycol monoethyl ether and/or ethylene glycol
monoisopropyl ether and/or 4-hydroxy-4-methyl-2-pentanone and/or
terpineol and/or diethylene glycol monoethyl ether and/or
tripropylene glycol monomethyl ether.
[0111] In another embodiment of the invention, the embossing
lacquer comprises a high proportion of polysiloxane. In particular
branched or linear methyl and/or phenylpolysiloxanes may be
used.
[0112] These polysiloxanes may be provided with UV-crosslinking
organic functional groups. Polysiloxanes having a high inorganic
solids content are preferably used.
[0113] In another embodiment of the invention, curing during the
embossing process is exclusively accomplished by UV light. In
another embodiment, a final thermal curing is performed in a
temperature range from 100 to 1000.degree. C., in particular
between 450 and 740.degree. C.
[0114] The duration of thermal curing may range from 2 min to 180
min, preferably from 3 min to 60 min.
[0115] The contact pressure of the stamp during embossing is
preferably adjustable between 0.01 and 5 bars.
[0116] In a refinement of the invention, compounds having a
dewetting or wetting effect may be added to the lacquer system
comprising the sol. These may be for example fluoro-organosilane
compounds. Prior to coating, the substrate may be treated with a
primer, or the surface may be preconditioned before applying the
embossing lacquer, for example by a plasma treatment.
[0117] In another embodiment of the invention, the master pattern
and/or the embossing stamp are coated with solutions which form a
monolayer that has a wetting or dewetting effect.
[0118] To ensure a long shelf life of the lacquer system,
to adjust the pot life on the screen and for high reproducibility
of the embossing result, a multi-component lacquer system, in
particular a two- or three-component lacquer system may be
used.
[0119] In one particular embodiment, a two-component system is
used. One component thereof is the hydrolyzed organically
functionalized silane, for example a solvent-reduced hydrolyzate of
tetraalkoxysilane and glycidylpropyltrialkoxysilane. Another,
second component comprises the metal oxide and/or semi-metal oxide
nanoparticles with a photoinitiator in a high-boiling solvent.
[0120] Before use, the two components are mixed in an appropriate
ratio and can then be used for more than 24 h.
DESCRIPTION OF THE DRAWINGS
[0121] The invention will now be explained in more detail with
reference to the drawings of FIGS. 1 to 6:
[0122] FIG. 1 schematically illustrates a master pattern 1 which in
this embodiment is a metal plate that has an etched periodic
pattern with diamonds as pattern elements 2. The spacing of these
pattern elements 2 is referred to as pitch t.
[0123] As shown in FIG. 2, a curable polymer mass is applied
thereto to produce a stamp 3.
[0124] After thermal curing of the polymer mass, as shown in FIG.
3, a stamp 3 has been created which comprises impressions of the
pattern elements 2. So the pitch t is identical.
[0125] FIG. 4 shows how a glass substrate 4 is coated with a
sol-gel layer 5. Coating is accomplished by a screen printing
process during which only a section of the glass substrate 4, here
the edge region, is printed.
[0126] Then, as shown in FIG. 5, stamp 3 is pressed onto sol-gel
layer 5. Stamp 3 may also be pressed onto areas of the glass
substrate 4 which are not coated. The dimension of the patterned
layer is defined by the screen printing process.
[0127] FIG. 6 schematically shows the final product, namely a
household appliance 6 which comprises a pane 9 produced according
to the invention, as a front pane.
[0128] Pane 9 has the patterned sol-gel layer 5 in its upper
surface area. In this case it is provided as a haptic pattern, i.e.
to achieve a specific tactile effect when touched. Furthermore, the
household appliance 6 has a handle 8 for opening and a display
field 7 in which patterned sol-gel layer 5 is omitted.
[0129] In detail, a patterned layer may be produced as follows, for
example:
[0130] In a vessel, 22.3 g (0.08 mol) of GPTES
(glycidyloxypropyltriethoxysilane) is provided with 4.1 g (0.02
mol) of TEOS (tetraethoxysilane), and is hydrolyzed with 2.3 g of
water in which 0.344 g of PTSA (p-toluenesulfonic acid) had been
dissolved. After having been stirred for 2 min, 110 g of a 15
mass-% alcoholic dispersion of irregularly shaped SiO.sub.2
nanoparticles in isopropanol is added to this hydrolyzate.
[0131] The nanoparticles have a fibrous shape, for example, with a
diameter from 5 to 15 nm and a length from 30 to 150 nm. 15 g of
tripropylene glycol monomethyl ether is added to this solution, and
the highly volatile solvent is removed in a rotary evaporator at
100 mbar and 50.degree. C. bath temperature. Then, 0.6 g of the
cationic photoinitiator Irgacure.RTM. 250 in 1 g of ethylene glycol
isopropyl ether is added to the embossing sol.
[0132] This lacquer system allows to apply layers to one side of a
soda lime glass by screen printing using a 180 mesh. After the
solvent has been dried off between room temperature and 80.degree.
C., with or without air circulation, a patterned silicone stamp
(PDMS) is applied, and then curing is accomplished through the
stamp using a UV lamp. When the stamp is removed the pattern of the
stamp had been transferred into the nanoparticle-functionalized
lacquer. The layers are now thermally cured at temperatures of
670.degree. C. for 4 min. The final thickness of the layer ranges
from 2.5 to 3 .mu.m.
[0133] Subsequently, a stainless steel layer is applied by a
sputtering process in a thickness of at least 100 nm.
[0134] Alternatively, a layer may be applied as follows:
[0135] In a vessel, 16.7 g (0.06 mol) of GPTES
(glycidyloxypropyltriethoxysilane) is provided with 4.1 g (0.02
mol) of TEOS (tetraethoxysilane) and 3.56 g (0.02 mol) of MTEOS
(methyltriethoxysilane), and is hydrolyzed with 2.3 g of water in
which 0.344 g of PTSA (p-toluenesulfonic acid) had been dissolved.
After having been stirred for 2 min, a mixture of 44 g of a 30
mass-% alcoholic dispersion of spherically shaped SiO.sub.2
nanoparticles with a diameter from 40 to 50 nm in isopropanol and
11 g of an alcoholic dispersion of spherical SiO.sub.2
nanoparticles with a diameter from 10 to 15 nm is added to this
hydrolyzate.
[0136] 16 g of ethylene glycol monoethyl ether is added to this
solution, and the highly volatile solvent is removed in a rotary
evaporator at 100 mbar and 50.degree. C. bath temperature. Then,
0.6 g of the cationic photoinitiator Irgacure.RTM. 250 in 1 g of
ethylene glycol monoethyl ether is added to the embossing sol.
[0137] This lacquer system allows to apply layers to one side of a
soda lime glass by screen printing using a 180 mesh. After the
solvent had been dried off between room temperature and 50.degree.
C., with or without air circulation, a patterned silicone stamp
(PDMS) is applied, and then the layer is cured through the stamp
using a UV lamp. When the stamp is removed the pattern of the stamp
had been transferred into the nanoparticle-functionalized coating.
The layers are now thermally cured at temperatures from 300 to
500.degree. C. A preferred heating rate is 3 K/min, with a holding
time of 1 h at 500.degree. C. The final thickness of the layer is
2.5 .mu.m.
[0138] The invention permits to provide specific haptics and
appearances on almost any substrates in a very economical way.
* * * * *