DYE MIXTURE FOR DETERMINING THE READINESS FOR COVERING OF LEVELLING COMPOUNDS

Abstract

The present invention relates to a dye mixture for determining the readiness for covering of levelling compounds, and also an application device which includes such a dye mixture. The present invention further relates to the use of the dye mixture for determining the readiness for covering of levelling compounds.

Claims

1. A dye mixture for determining readiness for covering of levelling compounds, comprising at least one sparingly water-soluble dye and at least one readily water-soluble dye.

2. The dye mixture according to claim 1, wherein the at least one sparingly water-soluble dye has a solubility in water of <10 g/l.

3. The dye mixture according to claim 1, wherein the at least one readily water-soluble dye has a solubility in water of >30 g/l.

4. The dye mixture according to claim 1, wherein the at least one sparingly water-soluble dye and/or the at least one readily water-soluble dye is/are selected from the group consisting of chromophoric dyes and auxochromic dyes.

5. The dye mixture according to claim 1, wherein the at least one sparingly water-soluble dye is selected from the group consisting of xanthene dyes and azo dyes and/or wherein the at least one readily water-soluble dye is selected from the group consisting of monoazo dyes and xanthene dyes.

6. The dye mixture according to claim 1, wherein the dye mixture further comprises a solvent in which the dyes are slurried and/or dissolved.

7. The dye mixture according to claim 6, wherein the solvent is selected from the group consisting of water, alcohol, and mixtures thereof.

8. An application device containing a dye mixture according to claim 1.

9. The application device according to claim 8, which is in the form of a pen, a brush, or a pipette.

10. (canceled)

11. A method for determining the readiness for covering of levelling compounds, comprising the steps: (a) providing a dye mixture according to claim 1; (b) applying the dye mixture to a levelling compound and allowing it to act for a defined period of time; and (c) establishing whether separation of the dyes present in the dye mixture has taken place.

12. The method according to claim 11, wherein separation of the dyes present in the dye mixture indicates that the levelling compound is not ready for covering and the absence of separation of the dyes present in the dye mixture indicates that the levelling compound is ready for covering.

13. The dye mixture according to claim 2, wherein the at least one sparingly water-soluble dye has a solubility in water of <1 g/l.

14. The dye mixture according to claim 3, wherein the at least one readily water-soluble dye has a solubility in water of >50 g/l.

15. The dye mixture according to claim 7, wherein the solvent ethanol.

16. The method of claim 11, wherein the dye mixture is present in an application device.

17. The method of claim 16, wherein the application device is in the form of a pen, a brush, or a pipette.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0050] FIG. 1 shows the chromatographic separation of dye mixtures on a levelling compound containing residual moisture.

[0051] FIG. 2: Dye mixture at the point in time of 1st bonding (readiness for covering not attained).

[0052] FIG. 3: Dye mixture at the point in time of 2nd bonding (readiness for covering attained).

[0053] FIG. 4: Dye mixture at the point in time of 3rd bonding (readiness for covering attained).

EXAMPLES

[0054] An illustrative dye mixture of the two colorants Basacid Rot 495 liquid and Sepisol Fast Black CN was made up and introduced into an empty ballpoint pen. The composition of the dye mixture was as follows: 81.9% by weight of Basacid Rot 495 liquid/16.4% by weight of EtOH 96%/1.7% by weight of Sepisol fast Black CN.

[0055] The functionality of chromatographic separation in the presence of residual moisture in a levelling compound was tested on a plurality of samples of the gypsum levelling compound UZIN NC 110 NEU having a thickness of about 3 cm. The samples poured into plastic beakers were taken from the beakers after 1 day, after 5 days and after 10 days and halved in the middle. The pen was subsequently applied over the entire cross section of the compound.

[0056] FIG. 1 shows the result of the 3 samples, with the uppermost sample having been removed from the beaker after one day, the middle sample after 5 days and the bottom sample after 10 days. The blue line on the left was applied using a commercial pen and serves as reference. The indicator substance described was in each case applied second and is thus directly to the right of the blue substance. The third line, which is only present on the first test specimen, is a mixture of Basacid Blau 762 liquid and Basacid Rot 495 liquid (mixture 50/50 by weight).

[0057] After drying for 1 day, a large amount of residual moisture is still present in the system.->Distinct separation over the entire cross section.

[0058] After 5 days, significantly less residual moisture is present in the system.->Slight separation takes place only in the lower region of the levelling compound.

[0059] After 10 days, separation is no longer visible.->The system is ready for covering.

[0060] The dye mixture described makes it possible to make damaging residual moisture in a levelling compound system visible and thus establish readiness for covering.

Example 2

[0061] In the following examples, the readiness for covering is determined on a gypsum-based, self-levelling compound by means of a dye mixture according to the invention.

[0062] To assess the readiness for covering, the following procedure was selected: Levelling compounds/screeds were applied in a layer thickness of about 3 mm. A concrete substrate which had been pretreated with a one-component rapid reactive primer which slowed passage of water vapour (UZIN PE 414 Turbo) and a dispersion-based bonding agent (Uzin PE 280) was selected as substrate.

[0063] In the following tables, the readiness for covering determined using a pen containing a dye mixture for chromatographic separation is compared with the readiness for covering determined by the above-described method. The dye mixture present in the pen comprises a sparingly water-soluble dye and a readily water-soluble dye. Testing was carried out before the expected readiness for covering (1st adhesive bonding), on attainment of readiness for covering (2nd adhesive bonding) and at a later point in time after readiness for covering (3rd adhesive bonding, positive sample).

TABLE-US-00002 TABLE 2 Pen with dye mixture Peel value after 24 h Peel value after 72 h Chromatographic separation 0.0 N/mm.sup.2 0.1 N/mm.sup.2 of the dyes visible over the full area. (FIG. 2) .fwdarw. Readiness for covering not yet attained

TABLE-US-00003 TABLE 3 Pen with dye mixture Peel value after 24 h Peel value after 72 h Chromatographic separation 0.8 N/mm.sup.2 1.2 N/mm.sup.2 of the dyes no longer takes place. (FIG. 3) .fwdarw. Readiness for covering attained

TABLE-US-00004 TABLE 4 Pen with dye mixture Peel value after 24 h Peel value after 72 h Chromatographic separation 1.1 N/mm.sup.2 1.4 N/mm.sup.2 of the substances no longer takes place. (FIG. 4) .fwdarw. Readiness for covering attained

[0064] The series of experiments shows that the readiness for covering of the levelling compound can be indicated by means of the proposed pen. It becomes possible to see that a large amount of free water is initially present in the levelling compound microstructure (point in time 1: FIG. 2). The insufficient development of peel strength in the experimental determination of the readiness for covering demonstrates that readiness for covering had actually not yet been attained.

[0065] At the 2nd point in time (FIG. 3) and also at the point in time 3 (FIG. 4) it can be seen that no or only very little free water is present in the microstructure.

[0066] The adhesive bonding tests demonstrate, by means of a peel strength development (see Table 3 and 4) which is necessary for functional and damage-free adhesive bonding, the functionality of the adhesive bond and thus confirm the readiness for covering.

[0067] The 3rd adhesive bonding was carried out at a point in time after the readiness for covering had been determined (positive sample), i.e. the levelling compound can in every case be covered functionally and without damage by a floor covering. The dye mixture indicates readiness for covering at this point in time (no chromatographic separation). The peel strength development likewise indicates that the levelling compound was ready for covering.