LIQUID COATING COMPOSITIONS, PROCESSES FOR PRODUCTION THEREOF AND USE THEREOF

Abstract

The present invention relates to a liquid coating composition comprising i) at least one inorganic binder of the generic formula Si.sub.aR.sup.1.sub.bO.sub.c(OR.sup.2).sub.d with a≧2, b≧0, c≧1, d≧5 and R.sup.1 and R.sup.2=organic radical, ii) at least one solvent and iii) at least one oxide pigment which, after addition of a mixture consisting of 15 ml of 1 M oxalic acid and 15 ml of 20% aqueous hydrochloric acid, based on 1 g of substance, under standard conditions, leads to a temperature rise of at least 4° C., to processes for preparation thereof and to the use thereof.

Claims

1. A liquid coating composition, comprising: i) at least one inorganic binder of the generic formula Si.sub.aR.sup.1.sub.bO.sub.c(OR.sup.2).sub.d with a≧2, b≧0, c≧1, d≧5 and R.sup.1 and R.sup.2=organic radical, ii) at least one solvent, and iii) at least one oxide pigment which, after addition of a mixture consisting of 15 ml of 1 M oxalic acid and 15 ml of 20% aqueous hydrochloric acid based on 1 g of substance, under standard conditions, leads to a temperature rise of at least 4° C.

2. The composition according to claim 1, wherein the pigment is based on a mixed oxide of a (semi)metal in more than one oxidation state and/or a pigment based on at least two mixed oxides of at least two (semi)metals each in one or more oxidation states.

3. The composition according to claim 2, wherein said pigment is a mixed iron-manganese oxide.

4. The composition according to claim 3, wherein said pigment is a copper-containing mixed iron-manganese oxide.

5. The composition according to claim 4, wherein the mixed iron-manganese oxide is obtainable via a calcination of manganese(II) oxide, manganese(III) oxide, iron(II) oxide and iron(III) oxide and copper(II) oxide.

6. The composition according to claim 5, wherein the pigment is assigned to the group of pigments having the Colour Index designation Pigment Black 26.

7. The composition according to claim 1, wherein a proportion of oxide pigment, based on the total mass of the composition, is 10%-50% by weight.

8. The composition according to claim 1, wherein R.sup.1 and R.sup.2=—CH.sub.3, —CH.sub.2CH.sub.3, —CH.sub.2CH.sub.2CH.sub.3, —CH(CH.sub.3).sub.2.

9. The composition according to claim 1, wherein the inorganic binder of the generic formula Si.sub.aR.sup.1.sub.bO.sub.c(OR.sup.2).sub.d has been prepared from a mixture of SiCH.sub.3(OCH.sub.2CH.sub.3).sub.3 and Si(OCH.sub.2CH.sub.3).sub.4.

10. The composition according to claim 1, wherein the at least one solvent is selected from the group consisting of an alcohol, an alkyl ester, an alkoxy alcohol, an alkoxyalkyl ester and mixtures thereof.

11. The composition according to claim 10, wherein the at least one solvent is selected from the group consisting of 1-methoxy-2-propanol, ethyl lactate, butyl acetate, ethyl benzoate, propylene glycol monomethyl ether acetate, tri(ethylene glycol) monoethyl ether, ethanol, isopropanol and butanol.

12. A process for producing a coating composition according to claim 1, said process comprising: admixing at least one alkoxysilane of the generic formula Si(OR.sup.2).sub.4 and optionally an alkylated alkoxysilane of the generic formula SiR.sup.1(OR.sup.2).sub.3 with R.sup.1 and R.sup.2=organic radical in aqueous solution with an acid or acid ester, to obtain a mixture, reacting said mixture to give a compound of the generic formula Si.sub.aR.sup.1.sub.bO.sub.c(OR.sup.2).sub.d, and admixing said compound with at least one oxide pigment which, after addition to a mixture of 15 ml of 1 M oxalic acid and 15 ml of 20% aqueous hydrochloric acid based on 1 g of substance, under standard conditions, leads to a temperature rise of at least 4° C., and at least one solvent.

13. A method for production of a non-conductive coating, said method comprising: contacting a substrate with the coating composition of claim 1, to obtain a coated substrate.

14. The process according to claim 13, further comprising: drying and then curing of the coated substrate.

15. A non-conductive coating obtained by the method of claim 13.

16. A black matrix obtained by the method of claim 13.

Description

EXAMPLES

Example 1

Making Up the Sol-Gel Matrix

[0070] Tetraethoxysilane (TEOS) (15.44 wt %) and methyltriethoxysilane (MTES) (66.18 wt %) are mixed [0071] Subsequently added thereto are demineralized H.sub.2O (9.18 wt %) and Hordaphos CCMS phosphoric ester (0.02 wt %) [0072] The mixture is stirred on a stirrer plate overnight [0073] Then demineralized H.sub.2O (9.18 wt %) is added again

Example 2

Production of the Dispersion

[0074] The 1-methoxy-2-propanol solvent (57.85 wt %) is initially charged, in order to dilute the sol-gel mixture to the suitable solids concentration [0075] Then 15.03 wt % of the sol-gel mixture is added [0076] The TEGO Dispers 710 dispersing and wetting additive (2.10 wt %) is added

[0077] Lastly, the pigment Spinel Black 47400 “deepest black (Fe,Mn)(Fe,Mn).sub.2O.sub.4” from Kremer Pigmente GmbH & Co. KG is added (amount 25.02 wt %) [0078] For the dispersion by means of an agitated mixer (Scandex), about 30 g of zirconium oxide grinding beads of size 0.4 to 0.6 mm are added [0079] The dispersion mixture is dispersed for at least 2 hours, but better 10 hours, in the agitated mixer [0080] After the dispersion, the grinding beads are removed by sedimentation or filtering

Example 3

Substrate Coating

[0081] As substrates to be coated, glass substrates are used [0082] Prior to coating, the glass substrates are cleaned with organic solvent (isopropanol), rinsed with DI water and then blown dry with nitrogen [0083] The dispersion is applied by means of a spin-coating method with the following parameters: 10 sec at 500 rpm, then 30 sec at 2000 rpm [0084] The curing is preceded by a prebake step, in order to gradually remove the solvent and prevent cracking of the layer (10 min at 100° C. on the hotplate) [0085] After the prebake, the temperature is increased gradually (within about 10-15 min) to 350° C. [0086] The curing takes place on the hotplate at 350° C. for one hour.