Moulded part with a substrate with removable protective varnish coating and method for producing same

The invention relates to a molded article having a substrate with a peelable protective lacquer layer as well as a preferred method for the production thereof.

In the further processing of substrates, for example made of metal, glass, glass ceramic or ceramic, multiple processing steps are often at a part of the surface carried out in order to impart to the substrate certain properties or functions.

For example, it is known to use glass as a substrate for panels (control panels) in household appliances and appliances in entertainment electronics. When these panels certain operating elements are arranged on a substrate made of glass, are used for selecting and controlling functions of the device to be operated. To manufacture these substrates are subjected to a side facing a user and to a user side away certain steps. For example, touch sensors can be attached, in which the location of the sensor on the user-facing side one or more regions with specific surface properties (handholds, areas of different surface roughness, color, etc.) are provided. The processing of such substrates is therefore often limited to certain areas of the surfaces. On the other hand such glass substrates (glass) are often applied one or more layers of paint to a remote user side, depending on the desired purpose, certain areas are such that they are transparent or translucent. In these cases, a lighting unit and / or a display for displaying certain symbols or characters are often arranged behind the glass.

In preparing such control panels thus undergo several processing steps. Thus, on the first surface of a dielectric substrate in general not only a conductor layer, but additional layers, such as layers of paint applied. Subsequently, for the manufacture of control panels in general still be populated with electronic components. The mounting and attachment (eg by soldering) with electronic components frequently occur spatially separated from the coating of dielekrischen substrate. It would be desirable in any case when the second surface of the substrate could be protected during these processing steps and / or after performing the manufacturing steps from mechanical or chemical influences.

Anyway, it can in the processing of glass substrates etc. but also come from other substrates, by shock, contact with sharp objects to damages to time either or costly repairs, permanent damage or serious damage even to a complete loss of the molding to lead.

The <patcit id="pcit0001" dnum="DE102005013884A1"><text>DE 10 2005 013 884 A1</text></patcit> and the <patcit id="pcit0002" dnum="EP1705163A1"><text>EP 1705163 A1</text></patcit> describe a control panel with a plan or curved base body of a dielectric material such as glass, glass ceramic or ceramic, which is reverse printed with at least one layer of einbrennbarer color as vitreous enamel or ceramic paint and at least one layer of conductive structures made einbrennbarer conductive paste, the conductor structures are formed for receiving at least one electronic component, and wherein a plurality of layers are applied from einbrennbarer color on the base body. The control panel is obtainable by baking the paint and the conductive paste in a single pass, the color and the conductive paste have substantially the same baking temperature. The conductor structures comprise at least one sensor element.

The <patcit id="pcit0003" dnum="DE102005054562A1"><text>DE 10 2005 054 562 A1</text></patcit> describes a photoimageable solder resist, which contains at least one powder coating resin, and its use for printed circuit boards.

The <patcit id="pcit0004" dnum="EP1487759B1"><text>EP 487 759 B1 1</text></patcit> describes a method for producing a metal-ceramic substrate in which on the surface side of a ceramic layer or a ceramic substrate using a high temperature bonding process at least one respective metal foil is applied and the metal foil on at least one surface side to the forming conductor paths, contact faces and the like is structured, to the metal surface of at least one metal foil or at least one metallization at least one order is applied from a solder resist.

Object of the invention it was against this background, a molded article comprising a substrate made of a metal, glass, glass ceramic or ceramic provide, wherein the substrate is protected in its handling with regards to damage its surface and in which this protection later use of the moldings not impaired. The object of the invention was also to provide a process for its preparation.

The solution of this object is achieved according to this invention by a shaped body and a method for its production with the features of corresponding independent claims. Preferred embodiments of the inventive molding are listed in the corresponding dependent claims. Preferred embodiments of the inventive molding correspond to preferred embodiments of the inventive method and vice versa, even if this is not explicitly stated herein.

The invention thus relates to a molded article comprising a substrate of a metal, glass, glass ceramic or ceramic having a first surface and a second surface, said substrate having on at least a part of its first and / or second surface, a protective layer comprising a peelable protective lacquer layer.

"Detachable protective lacquer layer" in the sense of the invention means that the protective varnish layer can be removed from the substrate, without this, the substrate is damaged. Preferably, the protective lacquer layer can mechanically be replaced in particular by pulling by a user.

The term "protective coating layer" means in particular a layer of a cured varnish. The term "paint" as used herein, however, means a more flowable composition, which can be applied to the substrate to produce the protective paint layer in general.

The substrate according to the present invention is preferably a dielectric substrate such as glass, glass ceramic or glass. Preferably, the substrate is glass, in particular a glass plate, generally a float glass plate. Most preferably, the substrate is made of safety glass. Then the shaped body is particularly resistant to breakage and even at high temperatures still stable.

In a preferred embodiment of the shaped body according to the invention is of the resist of the resist layer a by the action of heat and / or radiation-hardened lacquer, said lacquer, a curable, in particular by the action of heat or light, composition of polymerizable monomers and / or cross-linkable oligomers and / or includes polymers. Here, it is preferred that the curable composition has a solids content of at least 90%.

The moldings according to the invention is not particularly limited, as in numerous moldings often a substrate is to be protected in terms of potential damage.

More preferably, the molded body includes a control panel, which preferably again comprises a dielectric substrate made of glass, glass ceramic or ceramic having a first surface and a second surface, wherein a layer with conductor structures on the first surface and a peelable protective lacquer layer is arranged on the second surface. Here, the control panel preferably has a touch sensor. According to the invention as a touch-sensitive sensors, capacitive sensors are preferred. Moreover, it is preferred that at least one layer is disposed from one color paint between the layer with conductor structures on the first surface of the substrate and the substrate.

If control panels are generally all conductor structures, solder joints and electronic components, and any other components on a remote user of the control panel side of the substrate.

During molding of the invention, a peel-off aid is preferably attached. The peel-off aid is preferably a tab which can be grasped by a user who can thereby remove the protective coating from the substrate. The flap should be sufficiently stable in order to be gripped by a user. Otherwise, the peel-off aid is as thin as possible, the thickness depending on the nature of the material chosen and the desired rigidity of the peel-off aid. As a material of the peel-off aid is preferably a plastic, especially a thermoplastic plastic selected, for example, from polypropylene.

A device fitted to the protective lacquer layer peel-off aid may be within the protective coating but are between the substrate and resist also.

The protective layer has a thickness of 0.05 to 0.5 mm in general.

In a particularly preferred embodiment of the shaped body, the removable protective coating layer comprises a solder resist or consists thereof.

The invention also provides a process for producing a shaped body comprising a substrate of a metal, glass, glass ceramic or ceramic having a first surface and a second surface, wherein the substrate on at least a part of its first and / or second surface of a peelable having protective lacquer layer, comprising the steps of<ol><li>(A) applying a lacquer, said lacquer comprising a curable by the action of heat and / or radiation composition of polymerizable monomers and / or cross-linkable oligomers and / or polymers, at least a portion of a first surface and / or a second surface of the substrate ; and</li><li>(B) curing the coating by action of heat and / or radiation.</li></ol>

In a preferred embodiment of this process the varnish by means of screen printing on the first and / or second surface is applied.

The curable coating preferably has a solids content of at least 90%, and more preferably has a solids content of at least 95%, based on the total mass of the coating, according to DIN EN ISO 3251 (1 h, 125 ° C, 1 g sample weight).

The curable coating preferably comprises an aqueous solvent. In particular, preferably, the curable coating contains no organic solvents.

Moreover, preferably a viscosity of curable surface coating composition according to DIN EN ISO 3219 at 20 ° C in a range from 10,000 to 80,000 mPas. This viscosity can for example = 50 s-1 of the company Electron GmbH are measured with a viscometer Haake RS 600, C 20/1 °, D.

Preferably, the curable coating is thixotropic.

In general, the protective coating comprises a cured by heat and / or radiation exposure paint, wherein the paint is a composition of polymerizable monomers and / or cross-linkable oligomers and / or polymers. The protective coating preferably comprises epoxy resins, polybutadienes, polyurethanes, particularly with carboxyl or hydroxyl end groups, and mixtures thereof and reaction products.

The in moldings, eg control panel, used curable coating is preferably a solder resist. Preferably in that case a solder resist is used with a high thermal stability. This also allows for multiple temperature loads and use in conjunction with lead-free processes. In particular, preferably the thermal stability is so high that even a reflow soldering is possible.

Particularly suitable protective coatings are the solder masks of the series SD 2950 Lackwerke Peters GmbH + Co KG.

When using a dielectric substrate that is preferably transparent or semitransparent. A color print on the first page is then preferably recognizable.

The invention has numerous advantages. Thus, a molded body which comprises a substrate, for example made of a metal, but in particular of a dielectric material such as glass, glass ceramic and ceramic, from damage or other impairment of the surface of the substrate is protected. Thus, a control panel may be provided according to the invention, for example, wherein the dielectric substrate is protected during and after the production of the control panel. However, the present invention allows to protect both simple shaped bodies such as sheets of glass which are neither printed nor equipped with electronic elements, as well as of complex shaped articles, which may be, for example, sensors and electronic circuits and may also be printed with color lakes.

The invention is illustrated below with the aid of two non-limiting intentioned embodiments for a novel moldings.<ul><li><figref idrefs="f0001">Fig. 1</figref> shows a cross section through a mold body according to a first embodiment of the invention, which is a control panel here.</li><li><figref idrefs="f0001">FIG. 2</figref> shows a top view of an inventive shaped body according to a second embodiment of the invention, which here is also a control panel.</li></ul>

In the <figref idrefs="f0001">figure 1</figref> shown by a non-limiting embodiment meant a shaped body according to the invention, here an operating panel 1, a cross section. In the operation panel 1 on a first side (front side) 4 is a sheet of glass 2 is applied as a substrate a protective coating layer 6 of a cured varnish. is between the glass sheet 1 and the protective lacquer layer 6 as a peel-off aid 9 for the cured protective coating layer 6, a tab of a synthetic material, in this case polypropylene, is applied.

On the second side (back) of the substrate 2, two color layers 7 and 8 is applied, the recesses may have 12th On the colored layers 7 and 8 conductor pattern layers 3 are disposed, on which electronic components 10, in particular a pressure-sensitive sensor 11 may be attached, for example via a soldered connection.

For performing the method according to the invention is meant in the non-limiting embodiment shown here, in a first step, the substrate 2, which in the <figref idrefs="f0001">figure 1</figref> a glass plate is provided. After that first surface of the substrate is screen printed on the back, first a layer 8 and then applied a layer. 9 It is also possible that certain areas are not the back of the substrate 2 to be coated.

In the illustrated here advantageous embodiment of the invention after application of a color layer 8 or 9, respectively, an intermediate drying step is performed at about 100 to 150 ° C.

Thereafter, using screen printing at least one layer of conductive structures made of conductive paste einbrennbarer 3 on the back side of substrate 2, that is, applied to the substrate 2 or on the coloring layer 7 or eighth Conductor structures include electronic elements such as resistors or sensor elements. After the application of all ink layers 7 and 8 and the conductive paste for forming the conductor pattern layer 3, the baking of the layers is carried out in one step. The baking temperature is in the range of 600 to 700 ° C and is preferably about 620 ° C.

All coatings, and other components such as electronic components or connections are located on the first surface of the substrate so that the second surface forms a closed surface.

<figref idrefs="f0001">FIG. 2</figref> shows a top view of an inventive shaped body according to a second embodiment of the invention, which here is also a control panel.

On the user of the control panel facing the second surface 5 of the substrate 2 is partially a removable protective layer of lacquer 6 is applied. For ease of removability of the resist layer 6, a tab is applied as the peel-off aid 9 between the peelable protective lacquer layer 6 and the second surface of the fifth The protective lacquer layer 6 is disposed around recessed areas 13 and 14 on the second surface. 5 At these points, due to the non-existing protective coating, it was possible to process the second surface 5 of substrate 2 without any additional portions of the second surface have been damaged. In the embodiment shown here, the first region 13 is a function of the selection area corresponding to an upper hierarchy level and the second area 14, a specific selection area corresponding to a lower hierarchical level. This means that a user can select by touching the first region 13 is a function, by touching or by dragging a finger across the second zone 14, the function can be configured in detail (submenu; intensity). In the embodiment shown here, the surfaces of the regions 13 and 14 differ, the region 14 is embodied here matted and may also be designed to facilitate the recording of a finger slightly recessed.

LIST OF REFERENCE NUMBERS

<dl id="dl0001"><dt>1</dt><dd>Moldings, panel here</dd><dt>2</dt><dd>Substrate, here glass</dd><dt>3</dt><dd>conductor structure</dd><dt>4</dt><dd>First surface of the substrate</dd><dt>5</dt><dd>Second surface of the substrate</dd><dt>6</dt><dd>Protective lacquer layer</dd><dt>7</dt><dd>First coat of paint</dd><dt>8th</dt><dd>Second color layer</dd><dt>9</dt><dd>Peel-off, flap</dd><dt>10</dt><dd>Electronic component</dd><dt>11</dt><dd>Touch sensitive (pressure sensitive) sensor</dd><dt>12</dt><dd>recess</dd><dt>13</dt><dd>Function selection area (upper level of the hierarchy)</dd><dt>14</dt><dd>Specific selection area (lower level of the hierarchy)</dd></dl>