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EP-4735542-A1 - COMPOSITION FOR COATING SUBSTRATE SURFACES

EP4735542A1EP 4735542 A1EP4735542 A1EP 4735542A1EP-4735542-A1

Abstract

The invention relates to a composition, produced by reacting a first mixture with a second mixture, wherein (a) the first mixture is a mixture of at least the components (a 1 ) a chitosan; and (a 2 ) an aqueous solution of an acid, wherein the acid is a carboxylic acid, an inorganic acid or a mixture thereof; and (b) the second mixture is a mixture of at least the components (b 1 ) of a compound of the general formula (I) wherein R 1 is selected from the group consisting of a substituted or unsubstituted, branched or unbranched alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted, branched or unbranched alkenyl group with 2 to 20 carbon atoms, a substituted or unsubstituted aryl group and a substituted or unsubstituted alkyl aryl group; and R 2 , R 3 and R 4 independently of one another are each a branched or unbranched alkyl group with 1 to 6 carbon atoms; and (b 2 ) a (3-glycidyloxypropyl)trialkoxysilane.

Inventors

  • KROKE, EDWIN
  • KRAUSHAAR, Konstantin
  • WEIGEL, Mareike
  • BÖS, Markus
  • Seidel, Anne

Assignees

  • Technische Universität Bergakademie Freiberg Körperschaft des öffentlichen Rechts

Dates

Publication Date
20260506
Application Date
20240626

Claims (16)

  1. 1. A composition prepared by reacting a first mixture with a second mixture, wherein (a) the first mixture is a mixture of at least the components (ai) a chitosan; and (a2) an aqueous solution of an acid, wherein the acid is a carboxylic acid, an inorganic acid or a mixture thereof; and (b) the second mixture is a mixture of at least components (bi) of a compound of general formula I, (Formula I) where R 1 is selected from the group consisting of a substituted or unsubstituted, branched or unbranched alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted, branched or unbranched alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group and a substituted or unsubstituted alkylaryl group; and R 2 , R 3 and R 4 are each independently a branched or unbranched alkyl group having 1 to 6 carbon atoms; and (b2) a (3-glycidyloxypropyl)trialkoxysilane; is.
  2. 2. Composition according to claim 1, characterized in that the second mixture is a mixture of at least component (bi), component (b2) and a component (bi), wherein component (bi) is a compound of general formula (II) (Formula II) where R 5 and R 6 are each independently selected from the group consisting of a substituted or unsubstituted, branched or unbranched alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted, branched or unbranched alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group and a substituted or unsubstituted alkylaryl group; and R 7 and R 8 are each independently a branched or unbranched alkyl group having 1 to 6 carbon atoms.
  3. 3. Composition according to claim 1 or claim 2, characterized in that the alkoxy group of the (3-glycidyloxypropyl)trialkoxysilane is selected from the group consisting of methoxy, ethoxy, n-propoxy, /.w-propoxy, n-butoxy, /.w-butoxy, .scc-butoxy and /c/7-butoxy.
  4. 4. Composition according to one of the preceding claims, characterized in that component (a2) is aqueous acetic acid or aqueous hydrochloric acid.
  5. 5. Composition according to one of the preceding claims, characterized in that component (bi) is methyltriethoxysilane and that component (b2) is (3-glycidyloxypropyl)triethoxysilane.
  6. 6. Composition according to one of claims 2 to 5, characterized in that component (bi) is methyltriethoxysilane, that component (b2) is (3-glycidyloxypropyl)triethoxysilane and that component (bi) is dimethyldiethoxysilane.
  7. 7. Composition according to one of the preceding claims, characterized in that the first mixture and the second mixture are reacted in a mass ratio mi : m2 = 1 : 0.5 to 4.
  8. 8. Composition according to one of the preceding claims, characterized in that to obtain the first mixture, component (ai) and component (a2) are mixed in a mass ratio m ai : m a 2 = 1 : 30 to 130.
  9. 9. Composition according to one of the preceding claims, characterized in that to obtain the second mixture, component (bi) and component (b2) are mixed in a mass ratio mt,i : mt,2 = 10 to 30 : 1.
  10. 10. Composition according to one of claims 2 to 9, characterized in that to obtain the second mixture, component (bi), component (bs) and component (b2) are mixed in a mass ratio mt,i : mt,3 : mt,2 = 10 to 20 : 3 to 13 : 1.
  11. 11. A composition comprising a first composition and a second composition, wherein the first composition is a composition according to any one of claims 1 to 10 and the second composition is a mixture of at least the components (ci) an alkanol; (C2) a (3-glycidyloxypropyl)trialkoxysilane; and (C3) a crosslinker, wherein the crosslinker is selected from the group consisting of Ti(OR 9 )4, Zr(OR 10 )4, titanium acetylacetonate and mixtures thereof, wherein R 9 and R 10 are a branched or unbranched alkyl group having 1 to 10 carbon atoms;.
  12. 12. Composition according to claim 11, characterized in that the mass ratio of the first composition to the second composition is 0.5 to 5 : 5 to 0.5.
  13. 13. A composition prepared from a composition according to claim 11 or claim 12 by reacting the first composition with the second composition.
  14. 14. Use of a composition according to any one of claims 1 to 10 or claim 13 for coating a substrate surface or forming a shaped body.
  15. 15. A process for preparing a composition according to claim 13, characterized in that the first composition is mixed with the second composition.
  16. 16. Three-component system, comprising (a) a first mixture of at least the components (ai) a chitosan; and (a2) an aqueous solution of an acid, wherein the acid is a carboxylic acid or an inorganic acid; (b) a second mixture of at least the components (bi) a compound of general formula I, (Formula I) where R 1 is selected from the group consisting of a substituted or unsubstituted, branched or unbranched alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted, branched or unbranched alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group and a substituted or unsubstituted alkylaryl group; and R 2 , R 3 and R 4 are each independently a branched or unbranched alkyl group having 1 to 6 carbon atoms; and (b2) a (3-glycidyloxypropyl)trialkoxysilane; and (c) a third mixture of at least the components (ci) an alkanol; (C2) a (3-glycidyloxypropyl)trialkoxysilane; and (C3) a crosslinker, wherein the crosslinker is selected from the group consisting of Ti(OR 9 )4, Zr(OR 10 )4, titanium acetylacetonate and mixtures thereof, wherein R 9 and R 10 are a branched or unbranched alkyl group having 1 to 10 carbon atoms.

Description

Description Composition for coating substrate surfaces [0001] The invention relates to compositions which are particularly suitable for coating substrate surfaces. It also relates to an assembly comprising a first composition and a second composition. It also relates to uses of the compositions and methods for producing the compositions. [0002] DE 10 2019 110 519 Al [1] discloses a composition which is obtained by reacting a first composition with a second composition. The first composition contains an alkyltrialkoxysilane, a (3-glycidyloxypropyl)trialkoxysilane, water and optionally an inorganic acid, the second composition contains an alkanol, a (3-glycidyloxypropyl)trialkoxysilane and a crosslinker. The composition can be used to produce a sol-gel varnish with which substrate surfaces can be coated. [0003] Not every coating on a substrate surface is desirable. In order to prevent damage to the substrate by paint that is applied to a substrate surface, for example to create graffiti, a barrier layer can be applied to the substrate surface [5]. Such a barrier layer is intended on the one hand to prevent the graffiti paint from penetrating the substrate and on the other hand to facilitate the removal of the graffiti paint [6]. These barrier layers are applied, for example, to monuments, houses, trains and substrates in public places. Although the barrier layers do not prevent graffiti from being applied to a substrate surface, the easier removal of the graffiti prevents the use of chemicals for this purpose, which themselves or their by-products pose environmental and health risks as well as high financial costs [3, 4]. The barrier layers mentioned are referred to as anti-graffiti coatings (AGCs) when they contain a dye. [0004] Paints with a wide variety of chemical bases are used to produce graffiti. For example, so-called graffiti paints based on alkyd resins and acrylates, spray paints based on polyurethanes, chalk, ballpoint pen inks, marker paints that can be permanent or water-soluble, lipstick colors and wax and oil pastels are used [3, 7]. Adhesive labels and posters are also applied [3, 7]. It is a challenge to find a barrier layer that allows chemically different paints and adhesive labels and posters to be easily removed [8, 9]. At the same time, it is expected that the appearance of the substrate surface will remain unchanged by the barrier layer [9]. In addition, the barrier layer should be easy to apply to the substrate surfaces. In other words, the barrier layer should adhere to the substrate surface, but at the same time it should have a non-stick effect to make it more difficult to apply graffiti. Finally, the barrier layer should be resistant to certain cleaning methods and environmental influences [8, 9], [0005] Most of the currently used single-layer systems are based on hydrophobic and oleophobic products such as fluorinated siloxanes [10, 11], These are intended to reduce the surface energy of the coating and improve the oxidative, chemical and thermal stability [8, 12], Such a system is described in DE 10 2004 059 152 Al as a non-stick layer [13], However, the use of these fluorinated compounds is restricted on large surfaces due to their high costs and their environmentally hazardous effect [5], Tetraethoxy- and alkyltriethoxysilanes, on the other hand, have been described as strong hydrophobing agents and moderate fungicides [14], Anti-graffiti coatings are also known which are based on per- or polyfluorinated alkyl compounds (PF AS) [29], However, for the reasons mentioned, it is desirable that such coatings are fluorine-free. Approaches to producing fluorine-free anti-graffiti coatings include polyester-siloxane-based coatings [30], [0006] Antifouling and anticorrosion coatings are also known. The currently known systems rely in part on a modification of the surface properties, which is also often achieved by the addition of fluorinated alkyl chains or fluorine polymers [15-17], Active coatings are also used which continuously release active substances, e.g. catalytically or photocatalytically active substances, but thereby the introduced reagents are constantly consumed [18-20], [0007] The object of the invention is to eliminate the disadvantages of the prior art. In particular, a composition is to be specified which enables the production of a layer which has a non-stick effect. Furthermore, a composition which has a first and a second composition, a third composition produced from the composition, uses of the third composition and a process for producing the compositions are to be specified. [0008] This object is achieved by the features of claims 1, 11, 13, 14, 15 and 16. Expedient embodiments of the inventions emerge from the features of the subclaims. [0009] According to the invention, a composition is provided which is prepared by reacting a first mixture with a second mixture, wherein (a) the first mixture is a mixture of at least the components (ai) a chitosan; and (a2)