Ceramic Composite Wall Covering

Abstract

Disclosed is a wallcovering assembly consisting of a base material and at least one ceramic coating/topcoat with or without an optional ceramic interlayer.

Description

FIG. 1 depicts by way of example the construction of an inventive wallcovering assembly. A base material (1) supports a ceramic coating (2) as a top layer.

FIG. 2 depicts by way of example the construction of an inventive wallcovering assembly. A base material (1) supports a ceramic interlayer (3). This ceramic interlayer (3) supports a third layer, the top layer or ceramic coating (2), which normally forms the uppermost layer of the assembly.

FIG. 3 depicts schematically the section through the surface of an inventive wallcovering assembly where the surface texture is formed by the texture of the base material and not by the particles (P) in the matrix (M) of the top layer (2).

FIG. 4 depicts schematically a section through the surface of an inventive wallcovering assembly where the surface texture is formed not by the texture of the base material but by the particles (P) in the matrix (M) of the top layer (2).

The present invention is more particularly described by the examples which follow without the scope of the claims and the description being restricted by the examples.

EXAMPLE 1

Production of a Top Layer (2)

Component 1

224 g of GLYEO dynasylane, Degussa AG, were placed into a 1000 ml glass beaker. 20 g of 1% by weight hydrochloric acid were added with stirring at room temperature on a magnetic stirrer plate using a magnetic stirrer bar, stirring being continued until the solution became clear. 325.6 g of a 15% by weight dispersion of Aerosil R812S (Degussa AG) in ethanol were added with continued stirring at 400 rpm. The first component was thus ready to use.

Component 2

190 g of AMEO dynasylane (Degussa AG).

Production of Ready-to-Use Suspension

Component 2 was gradually added dropwise to component 1 through a dropping funnel over a period of 20 min with monotonous stirring. The suspension is now ready for processing. The pot life was 9 days at room temperature.

Processing

The ready-to-use suspension was knifecoated by means of a Mathis hand pull frame at 25 μm on a wallpaper base (paper web having a PET content of about 10% by weight) or a PET nonwoven from Freudenberg having a thickness of 220 μm and a basis weight of 50 g/m² (PET FFKH 7210) and subsequently heated for 30 minutes at 120° C. (wallpaper base) or 140° C. (PET nonwoven). The wallcovering assembly thus obtained was then subjected to material testing.

EXAMPLE 2

Production of a Top Layer (2)

Component 1

226.09 g of GLYMO dynasylane, Degussa AG, were placed in a 500 ml glass beaker. 11.46 g of 1% by weight hydrochloric acid were added with stirring using a magnetic stirrer plate and a magnetic stirrer bar.

Component 2

87 g of bisphenol A were introduced as an initial charge. 9.65 g of Aerosil R812S (silica from Degussa AG) were added with continued stirring at 400 rpm. This batch was covered over and stirred for 20 hours. 7.63 g of 1-methylimidazole activator were slowly added with stirring.

Production of Ready-to-Use Suspension

Component 2 was gradually added dropwise to component 1 through a dropping funnel over a period of 20 min with monotonous stirring. The suspension is now ready for processing. The pot life was 4 days at +4° C.

Processing

Processing was done as in Example 1.

EXAMPLE 3

Production of a Ceramic Layer (3)

67.5 g of CT 3000 SG alumina (AlCoA), 7.5 g of ethanol, 15 g of 5% by weight nitric acid, 0.05 g of 2-(2-(2-methoxyethoxy)ethoxy)acetic acid (TODS), 1.25 g of tetraethoxysilane (TEOS), 2.5 g of GLYMO and 1.25 g of methyltriethoxysilane (MTES) are mixed at room temperature and 400 revolutions per minute rpm on a magnetic stirrer plate for 24 hours. The suspension thus obtained was knifecoated onto the PET nonwoven in a thickness of 50 μm as per Example 1 and the assembly thus obtained was heated at 130° C. for 30 minutes.

EXAMPLE 4

Production of an Assembly Comprising Not Only a Ceramic Layer (3) But Also a Top Layer (2)

The assembly which is obtained as per Example 3, from base material (1) and ceramic layer (3), was used as a base material in a process as per Example 1 and provided with a top layer (2) accordingly.

EXAMPLE 5

Production of an Assembly Comprising Not Only a Ceramic Layer (3) But Also a Top Layer (2)

The assembly which is obtained as per Example 3, from base material (1) and ceramic layer (3), was used as a base material in a process as per Example 2 and provided with a top layer (2) accordingly.

COMPARATIVE EXAMPLE (POT LIFE)

226.09 g of GLYMO, 87 g of bisphenol A, 11.46 g of 1% hydrochloric acid, 9.56 g of Aerosil R972, 7.63 g of 1-methylimidazole and 7.63 g of MEMO are intimately mixed. The pot life was less than 1 day at room temperature.

Some of the wallcovering assemblies obtained in Examples 1 to 4 were used for various tests.

EN 13523-4 Pencil Hardness Test

An EN 13523-4 pencil hardness test was carried out. The hardness of the pencils used was used to determine which mechanical friction stress the assemblies are capable of withstanding. The degrees of hardness indicated below in table 1 correspond to the pencil hardnesses at which neither a scratching of the surface nor a destruction of the base material was observed. The pencils used, which differ in hardness, are designated 8B, 7B, 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 5H, 6H, 7H, 8H and 9H, sorted from soft to hard.

TABLE 1
Result of EN 13523-4 pencil hardness test
	Ceramic	Top layer (2) as per	Degree of hardness
Base material	layer (3)	example	to surface damage
PET nonwoven (Example 3)	yes	none	4B
PET nonwoven (Example 4)	yes	1	B
PET nonwoven (Example 5)	yes	2	8H
Wallpaper base	none	none	B
Wallpaper base (Example 2)	none	2	8H

The EN 13523-4 pencil hardness test shows that a topcoating with the 2-component system as per Example 2 distinctly improves the surface resistance to scratching stresses as per the pencil hardness test.

DIN 53 438 Part 3 Flame Exposure Test

Evaluation

F1: The upper measuring mark is not reached by the flame front of the burning specimen (specimen extinguishes earlier)

F2: Flame front of burning specimen reaches the upper measuring mark in 20 seconds or later

F3: Flame front of burning specimen reaches the upper measuring mark in less than 20 seconds.

Result of Test of Fire Behavior

An uncoated PET nonwoven, 220 μm in thickness, 50 g/m² from Freudenberg (PET FFKH 7210) melts during flame exposure and thus has to be rated F3. A PET nonwoven with a ceramic layer (3) as per Example 3 shows holing in the flame-exposed region but no afterburning and thus has to be rated F1. A PET nonwoven with a ceramic layer (3) and a top layer (2) as per Example 4 shows holing in the flame-exposed region but likewise no afterburning and thus likewise has to be rated F1. : F1 (holing in flame-exposed region, but no afterburning).

The aforementioned tests show that inventive wallcovering assemblies which comprise a ceramic coating as a topcoating layer have a surface which is notable for good scratch resistance and good fire behavior (low flammability).

Claims

1. A wallcovering assembly comprising a base material and at least one ceramic coating comprising ceramic particles selected from the oxides, nitrides, borides or carbides of the metals or semimetals embedded in a matrix consisting of a silicon network linked together by Si—O—Si bridges, wherein one or more ceramic interlayers are present between the base material and the ceramic layer andthe ceramic interlayer contains particles of an inorganic component comprising essentially at least one component selected from the group consisting of at least one metal at least one semimetal and at least one mixed metal with at least one element of the third to seventh main group that are bonded by at least one inorganic adhesive to each other and to the layer present underneath the ceramic interlayer.

2. The wallcovering assembly of claim 1, wherein the base material is a nonwoven, a woven, a formed-loop knit, a felt, a film, a single- or multi-layered paper, or a wallpaper.

3. The wallcovering assembly claim 1, wherein the base material is a sheetlike structure comprising predominantly cellulose fibers, polymeric fibers, glass fibers, metal fibers or ceramic fibers, or is a polymeric film.

4. The wallcovering assembly according to claim 1, wherein the silicon network comprises organic radicals that are bound to silicon.

5. The wallcovering assembly of claim 4, wherein in each case two organic radicals are bound together via covalent bonds.

6. The wallcovering assembly according to claim 1, wherein the ceramic coating comprises particles having an average particle size from 1 nm to 1 μm for the elementary particles.

7. The wallcovering assembly according to claim 1, wherein the ceramic coating comprises particles of oxides of the elements Al, Zr, Si, Ti, Ce or Fe.

8. The wallcovering assembly of claim 1, wherein the ceramic coating comprises POSS clusters or hydrophobicized silicas as particles.

9. The wallcovering assembly of claim 1, wherein the ceramic coating is less than 100 μm in thickness.

10. The wallcovering assembly of claim 1, wherein the ceramic coating is transparent to electromagnetic radiation having a wavelength in the region of visible light.

11-12. (canceled)

13. The wallcovering assembly of claim 1, wherein the ceramic interlayer comprises particles of oxides selected from Al2O3, ZrO2, TiO2 and/or SiO2 having an average particle size from 200 nm to 5 μm and a silicon network, the silicon of the network being bonded via oxygen atoms to the oxides of the ceramic coating, via organic radicals to the layer underneath the top layer and via at least one chain of carbon atoms to a further silicon.

14. The wallcovering assembly of claim 1, further comprising an interlayer that contains one or more components selected from adhesives, adhesion promoters, binders, dyes and pigments.

15. The wallcovering assembly of claim 1, wherein the wallcovering assembly is flexible and can be wound up into a roll.

16. A process for producing a wallcovering assembly as of claim 1, comprising producing a final ceramic coating by a suspension comprising ceramic particles suspended in a polymeric sol produced by mixing at least one silane with an alcohol and an acid being applied to a base material after application of one or more ceramic interlayers and subsequently solidified, wherein the ceramic interlayer is applied by applying and solidifying a suspension comprising particles of an inorganic component suspended in a sol to the base material or further in ceramic interlayers optionally presented and subsequently solidifying the suspension on and optionally in the base material or the further ceramic layer optionally present, andthe suspension used for producing the ceramic interlayer comprises at least one sol that acts as an inorganic adhesive and comprises at least particles of an inorganic component comprising essentially at least one compound selected from the group consisting of at least one metal, at least one semimetal, and at least one mixed metal with at least one element of the third to seventh main group.

17. The process of claim 16, wherein oxides, carbides, nitrides or borides of metals or semimetals are used as ceramic particles.

18. The process of claim 16, wherein the suspension is solidified by heating when the sol is based on tetraethoxysilane (TEOS), 3-glycidyloxytrimethoxysilane (GLYMO) and/or 3-glycidyloxytriethoxysilane (GLYEO) and/or 3-methacryloyloxypropyltrimethoxysilane (MEMO).

19. The process of claim 18, wherein a suspension comprising di- or polyols is used.

20. The process of claim 18, wherein the suspension is produced in two steps, a first step of initially producing a mixture of first silane, alcohol and acid, into which mixture the particles are stirred, and a second step of adding to this first component a further silane and/or a diol or polyol as a second component before the suspension is heated.

21. The process of claim 20, wherein the suspension is produced in two steps, a first step of initially producing a mixture of GLYEO, alcohol and acid, into which mixture the particles are stirred, and a second step of this first component having added to it AMEO and/or bisphenol A as a second component before the suspension is heated.

22. The process of claim 18, wherein the heating takes 1 second to 2 hours at temperatures from 50 to 650° C.

23. The process of claim 16, wherein the suspension is solidified by treatment with UV rays when the sol is based on methacryloyloxypropyltrimethoxysilane (MEMO).

24. The process of claim 16, further comprising applying an interlayer containing an adhesive, an adhesion promoter, a dye, printing inks or a binder.

25. The process of claim 16, wherein the individual layers are applied to the base material in a roll-to-roll process.