USE OF A PRIMER FOR SILICON SURFACES

Description

[0001] The invention relates to the use of an agent for priming silicone surfaces, namely vulcanized silicone joints on windows, doors, in the glazing area and in the sanitary area. background

[0002] Silicone surfaces cannot be painted over without the agent according to the invention. State of the art

[0003] In contrast to the invention, Euroteam offers joint tapes for new installations (DE 20 2015 006 906 Ul). These are not made of silicone, but of polyurethane. Aside from the fact that polyurethane is certainly paintable, Euroteam's joint tapes are intended for bonding to surfaces such as concrete, stone, etc., but not for subsequent painting.

[0004] These products are in no way comparable to the present invention. Their application and field of use are not even related to the product itself. Silicone joints are already existing construction joints on windows, doors, glazing, plumbing, and even construction areas, such as vehicles and machinery.

[0005] In contrast to the aforementioned state of the art, it should be possible to apply smooth and abrasion-resistant coatings to existing, vulcanized silicone joints and other sealants.

[0006] A method for priming silicone surfaces is known from WO 2019 / 134 817 A1. For this purpose, a mixture of an impregnating agent, a varnish, and water or without water is used to prime silicone surfaces. The mixture of the components is prepared immediately before application. The impregnating agent contains an acid, is anhydrous, and is a silicon dioxide precursor that hydrolyzes to silicon dioxide particles in an acidic environment in the presence of water. The varnish is a water-dilutable dispersion paint.

[0007] In this case, it is therefore necessary that the mixture of components to be applied be prepared only immediately before use. This mixture does not contain any comparable ingredients to the product according to the invention.

[0008] Document KR 101941422 B1 concerns the manufacture of a piece of jewelry or accessory. It describes the production of a germanium chip, comprising the steps of first preparing a germanium chip, then mixing a resin with fine-grained gold powder and ferrite powder to produce a coating film, and then surface-treating said germanium chip with the aforementioned coating film.

[0009] Document CN 105062255 A discloses an antibacterial emulsion as a paint primer and a corresponding manufacturing process. Specifically, a primer layer is intended to be created on buildings or their walls or ceilings before applying a latex coating. The focus is on antibacterial and fire-retardant aspects, but also on the use of plant-based raw materials wherever possible.

[0010] The subject of document US 4,348,435 A is the improvement of the adhesion between silicone elastomer-based adhesives and organic elastomers. For this purpose, a primer is to be used that adheres to both the silicone elastomer adhesive and the organic elastomer. The goal is to create a multi-glazing element in which individual glass panes are kept apart by means of spacers. Task and solution of the invention

[0011] Object of the invention: The above-mentioned disadvantages of the prior art are to be avoided.

[0012] This object is achieved according to the invention when using an agent for priming silicone surfaces of the type mentioned at the outset in that the agent is an emulsion with at least the following components: a catalyst used for the vulcanization of rubber compounds, an organic solvent or diluent, glass powder, a lacquer paint as a carrier substance. Advantages of the invention

[0013] Among other things, the following advantages are achieved: The invention enables smooth and abrasion-resistant coatings of existing, vulcanized silicone joints and other sealants.

[0014] The emulsion is compatible with most commercially available paint systems.

[0015] The agent according to the invention consists of at least four necessary components, but may also contain additional ingredients. The four necessary components have the following functions: The first component, the catalyst, serves to crosslink the agent after it has been applied to the silicone surface.

[0016] The second component, the organic solvent or diluent, is mainly used to adjust the desired viscosity.

[0017] The third component, the glass powder, also called glass flour, is responsible for the adhesion of the primer to the silicone surface.

[0018] Alternatively, tetrapodal zinc oxide can be used instead of glass powder or in combination with it. Further details can be found in the applicant's German patent application 10 2021 100 113.7, filed January 6, 2021.

[0019] The fourth component, the carrier substance, namely the paint, enables or promotes the bonding and adhesion of the subsequent coat to the applied and cured primer. According to the invention, component 1 (catalyst), which has the function of a connector in the overall system, can be used:

[0020] In particular, a vulcanization component is very well suited for the production of a technical silicone rubber.

[0021] The products TFC silicone rubber type 2-1 from the manufacturer Trollfactory and "Replisil 35 NO component B" from the manufacturer Siliconic are advantageous for this purpose. According to the invention, component 2 (organic solvent or diluent) can be used:

[0022] Particularly preferred is white spirit or cleaning spirit, e.g., Shellsol®< D 60 from Shell. Shell products D40, D100, D120, D140, and D160 are also available.

[0023] It is also possible to use an oil from the group of turpentine oil balsam and / or linseed oil, and / or natural oils and / or mineral oils.

[0024] Other products that can be used advantageously include turpentine or Owatrol Oil. Owatrol Oil is a highly penetrating, air-drying oil that can be used alone or as a paint additive. According to the invention, component 3 (glass powder) can be used:

[0025] To modify the surface structure and to change the adhesion properties, it is possible to change the glass powder structure. According to the invention, component 4 (carrier substance) can be used:

[0026] A water-dilutable emulsion paint or preferably an acrylic paint can be used.

[0027] The product "Orgal PR 842A", an acrylic dispersion varnish, and / or the product "Plextol D487" from the manufacturer Synthomer, a pure acrylic dispersion, can be used with advantage.

[0028] In developing the invention, the inventor has overcome the following technical difficulties in a non-obvious manner: A basic basis had to be identified that would ensure the most stable and smooth adhesion to the sealant surface (silicone): the paint carrier. To better stabilize the adhesive force under mechanical influences, a substance was to be added that creates a kind of claw with the surface: the glass powder. Furthermore, it was necessary to add a substance chemically similar to silicone that ensures compatibility with the silicone surface: white spirit. In chemistry, a catalyst is a substance that increases the reaction rate by lowering the activation energy of a chemical reaction without itself being consumed. It accelerates the forward and reverse reactions equally and thus changes the kinetics of chemical reactions, not their thermodynamics. The aforementioned substances had to be dispersed under vacuum conditions.

[0029] Advantageous embodiments of the invention are set out in the subclaims.

[0030] Thus, the paint used as a carrier substance preferably contains 20 to 70 wt.% of a binder from the group consisting of acrylate dispersion paint, polyurethane, epoxy, an epoxy-based paint binder, e.g., Epoxid Esta, alkyd, polysiloxane, an acrylic-based paint binder, e.g., Lipaton SB 4520 from Synthomer, and / or a pure acrylate dispersion.

[0031] Advantageous applications of the new composition include the actual preparation of existing silicone joints on windows, doors, glazing areas, sanitary areas and even construction areas for subsequent painting systems.

[0032] Instead of unsuitable sealants, such as acrylates, high-quality sealants in the form of silicone can be used, since the product according to the invention can now be painted.

[0033] Other advantageous applications include barrier properties for interactive influences, which prevent plasticizer migration and / or isolate, for example, water, grease, and soot stains. The color transformation of silicone-containing products by painting over them. Examples of implementation

[0034] Several embodiments of the invention are described in more detail below.

[0035] An example of the application of the product according to the invention to actually prepare existing silicone joints on windows, doors, in glazing, in plumbing, and even in the construction area for subsequent painting: Painter Meier is to paint an existing four-story apartment block with 16 residential units white. There are 96 windows in the apartment block. This means that approximately 400 meters of gray silicone joints are present on the windows. A further 150 meters of gray expansion joints are present on the building. This means that there are 550 meters of silicone joints on the building.

[0036] There's no way to paint over the existing silicone joints using current technology. Now, painter Meier will have to hire another company to remove the existing joints and have them re-grouted to match the white paint. The cost for restoration or re-grouting is approximately €6,000 net.

[0037] If painter Meier uses the product according to the invention, existing joints can be painted over. In addition to saving a significant amount of time, the cost of painting the joints in the appropriate color now amounts to approximately €700.00 net (approximately 8 m² of joint coating). Painter Meier and his client have thus saved almost 90% of the costs. Another example:

[0038] Drywall builder Janssen is tasked with the interior finishing of a plaster wall paneling. To complete the work for the painter, Janssen uses an acrylic sealant, as usual, to seal the connecting joints on the ceiling and wall. However, drywall builder Janssen is aware of the disadvantages of using acrylic. In the past, he has used this paintable sealant.

[0039] Sealant has repeatedly experienced detachments due to overstretching after months or even years, which have been complained about by customers.

[0040] The reason for this is that acrylic is subject to shrinkage due to its high water content. The elongation of acrylic sealants is also generally limited to 7%. This technical property leads to the og problems.

[0041] However, if Janssen now uses a higher-quality silicone-based sealant in the connecting joints, the previously mentioned problems of detachment are eliminated due to the silicone's higher movement absorption (approximately 25% and more).

[0042] Since both drywallers and painters subsequently use the product according to the invention, it demonstrates that the product can be used by a variety of tradespeople in various construction phases, both indoors and outdoors. The high-quality availability reduces complaints, saves costs, and ensures a satisfied end customer.

[0043] The following composition is optimal, for example: catalyst 7, 14 % by weight White spirit 10 % by weight Glass 7, 14 % by weight paint 75, 72 % by weight Preparation of the composition according to the invention

[0044] In the specified ratios, all four components are mixed under vacuum in a dispersing stirrer. Automated filling is possible. Test of the above composition

[0045] Long-term tests of painted silicone and sealant surfaces were conducted with positive results under European weather conditions. Preparation of a composition according to the invention

[0046] Glass flour / glass powder ST 240 from Reidt GmbH & Co. KG, 52224 Stolberg Catalyst from Troll Factory Rainer Habekost eK, 27339 Riede White spirit Shellsol ®< D 60 from Shell Acrylic paint from PA Jansen GmbH u. Co. KG, Bad Neuenahr-Ahrweiler Results of the tests with these compositions according to the invention

[0047] "Oil" here means an organic solvent or thinner or white spirit. Test 4 Percent by weight impact Result Catalyst 7, 14 % Optimal viscosity Good adhesion and coverage, without runs Öl 10 % Glass powder 7, 14 % paint 75, 72 % 75.72% Acrylic lacquer Jansen 7.14% Glass powder / glass flour 10.0% D60 white spirit 7.14% Catalyst (silicone rubber) Other beneficial recipes: Test recipe 1:

[0048] 70.14% Lipaton SB4520 from Symthomer 9.07% Glass powder / glass flour 11.60% D60 white spirit 9.19% Catalyst (silicone rubber) Test recipe 2:

[0049] 76.39% polyurethane varnish water-based 7.14% glass powder / glass flour 10.00% D60 white spirit 6.47% catalyst (silicone rubber) Test recipe 3:

[0050] 56.6% Acrylic paint water-based Wilckens 25.157% Glass powder / glass flour 7.547% D60 white spirit 5.66% Catalyst (silicone rubber) 5.031% Owatrol Comparative tests

[0051] Test 1 Percent by weight impact Result Catalyst 1, 5 % Viscosity too high Too little adhesion, slight gradients Öl 3 % Glass powder 5 % paint 90, 5 % Test 2 Percent by weight impact Result Catalyst 1, 5 % Too low viscosity Too watery solution, strong gradients Öl 20 % Glass powder 7 % paint 71, 5 % Test 3 Percent by weight impact Result Catalyst 1, 5 % desired viscosity Too rough surface, without gradients Öl 10 % Glass powder 9 % paint 79, 5 %

Claims

1. A use of an agent for priming silicon surfaces, namely vulcanized silicone joints on windows, doors, in the glazing area and sanitary areas, characterized in that, the agent is an emulsion including at least the following components: - a catalyst configured to vulcanize rubber mixes, - an organic solvent or thinner, - a fine particle solid material configured as a thickener and adhesion enhancer - a varnish paint forming a carrier substance.

2. The use of the agent for priming the silicon surfaces according to claim 1, characterized in that, the catalyst configured to vulcanize the rubber mixes is configured as a catalyst configured to vulcanize silicone rubber, as a TFZ-silicone-rubber-type- 2-1 catalyst, a catalyst for siloxane, or a catalyst for synthetic rubber and / or natural rubber.

3. The use of the agent for priming the silicone surfaces according to claim 1, characterized in that, the organic solvent or thinner is configured as white spirit.

4. The use of the agent for priming the silicone surfaces according to claim 1, characterized in that, the organic solvent or thinner is configured as an oil from the group consisting of turpentine oil balm, linseed oil, in particular cold pressed linseed oil, natural oil, in particular rapeseed oil, mineral oil or almond oil.

5. The use of the agent for priming the silicone surfaces according to claim 1, characterized in that, the fine particle solid material is configured as glass powder and / or tetrapodal zinc oxide.

6. The use of the agent for priming the silicone surfaces according to claim 1, characterized in that, the varnish paint is configured as water thinnable dispersion varnish paint, a varnish paint including solvent, an acrylic varnish paint, a PU-varnish, a water based polyurethane varnish or an acrylic water varnish.

7. The use of the agent for priming the silicon surfaces according to claim 1, characterized in that, the agent includes 3 -10 percent by weight catalyst, 5 to 20% by weight organic solvent or thinner, 4 - 40% by weight glass powder and / or tetrapodal zinc oxide, and 50 to 80% by weight varnish paint.

8. The use of the agent for priming the silicon surfaces according to claim 1, characterized in that, the agent includes 6 to 9% by weight catalyst, 5 to 15% by weight organic solvent or thinner, 5 - 8% by weight glass powder, and rest varnish paint.

9. The use of the agent for priming the silicon surfaces according to claim 1, characterized in that, the agent includes polyvinyl pyrrolidone.

10. The use of the agent for priming the silicon surfaces according to claim 1, characterized in that, the agent includes titanium dioxide and / or food starch and / or flour.

11. The use of the agent for priming the silicon surfaces according to claim 1, characterized in that, the varnish paint used for the carrier substance includes 20 - 70% by weight of a binder from the group consisting of acrylate dispersion varnish, polyurethane, epoxy, an epoxy-based paint binder, alkyd, polysiloxan and, an acrylic based paint binder, and / or a pure acrylate dispersion.