MAGNETIC FLOOR SURFACE

Abstract

The present invention is directed to a method for providing a surface, in particular a floor surface, with a layer of a magnetic and/or magnetizable cover composition, the surface having at least one layer of cementitious material, wherein the method comprises the step of spreading the layer of the cover composition onto the surface, the cover composition comprising a polymeric binder and magnetic and/or magnetizable particles, characterized in that the layer of the cover composition has a water vapor transmission rate of at least 0.25 g h.sup.1 m.sup.2 according to ASTM D1653, and the surface and/or the layer of cementitious material has a relative humidity of more than 75% according to ASTM F 2170-11.

Claims

1-19. (canceled)

20. A floor surface comprising at least one layer of cementitious material bearing a layer of a cover composition comprising a polymeric binder and magnetic and/or magnetizable particles, wherein the layer of the cover composition has a water vapor transmission rate of at least 0.25 g h.sup.1 m.sup.2 according to ASTM D1653, and the surface and/or the layer of cementitious material has a relative humidity of more than 75% according to ASTM F 2170-11 when the layer of the cover composition is applied.

21. A floor surface, comprising: at least one layer of cementitious material having a cementitious surface; and a cover composition layer applied on the cementitious surface of the at least one layer of cementitious material, the cover composition layer having a water vapor transmission rate of at least 0.25 g h.sup.1 m.sup.2 according to ASTM D1653 and comprising a polymeric binder and magnetic particles, magnetizable particles, or a combination of magnetic and magnetizable particles, wherein the at least one layer of cementitious material, the cementitious surface, or a combination of the at least one layer of cementitious material and the cementitious surface has a relative humidity of more than 75% according to ASTM F 2170-11 when the cover composition layer is applied on the surface of the at least one layer of cementitious material.

22. The floor surface according to claim 21, wherein the at least one layer of cementitious material, the cementitious surface, or a combination of the at least one layer of cementitious material and the cementitious surface has a relative humidity in a range of 80 to 98% according to ASTM F 2170-11 when the cover composition layer is applied on the surface of the at least one layer of cementitious material.

23. The floor surface according to claim 21, wherein the at least one layer of cementitious material, the cementitious surface, or a combination of the at least one layer of cementitious material and the cementitious surface has a relative humidity in a range of 85 to 95% according to ASTM F 2170-11 when the cover composition layer is applied on the at least one layer of cementitious material.

24. The floor surface according to claim 21, wherein the cover composition layer is spread on the layer of cementitious material.

25. The floor surface according to claim 21, wherein the cover composition layer has a water vapor transmission rate according to ASTM D1653 of at least 0.30 g h.sup.1 m.sup.2.

26. The floor surface according to claim 21, wherein the cover composition layer has a water vapor transmission rate according to ASTM D1653 of at least 0.4 g h.sup.1 m.sup.2.

27. The floor surface according to claim 21, wherein the polymeric binder is prepared from a precursor composition comprising: A) a polyisocyanate component, B) an amine-group containing component, C) optionally a polyol component, D) optionally one or more catalysts, and E) optionally a material selected from fillers, extenders, pigments or combinations thereof.

28. The floor surface according to claim 27, wherein the polyisocyanate component has an average NCO-functionality of 1.5 to 4.

29. The floor surface according to claim 28, wherein the polyisocyanate component comprises a polyisocyanate prepolymer derived from an uretdione, a biuret or an isocyanurate of hexamethylene di-isocyanate (HDI), or any combination thereof, optionally blended with the uretdione, the biuret or the isocyanurate of HDI or any combination thereof.

30. The floor surface according to claim 29, wherein the polyisocyanate prepolymer has an isocyanate (NCO) content of 5-15% by weight.

31. The floor surface according to claim 28, wherein the polyisocyanate component comprises a polyisocyanate prepolymer derived from the isocyanurate trimer of HDI, blended with the uretdione of HDI.

32. The floor surface according to claim 27, wherein the amine-group containing component is an aspartate ester or a composition of the general formula I: ##STR00009## wherein X is alkyl, alkylene, aryl or arylene with a valency of n, R.sub.1, R.sub.2, R.sub.4 and R.sub.5 are each independently selected from hydrogen, alkyl or aryl, R.sub.3 is alkyl or aryl, and n is an integer greater than or equal to 1.

33. The floor surface according to claim 32, wherein n is 2 and X is alkylene or arylene.

34. The floor surface according to claim 27, wherein the amine-group containing component is an aspartic ester or a composition of the general formula V ##STR00010## wherein R.sup.11 is an aliphatic group of 1-20 carbon atoms and R.sup.10 is alkyl or aryl.

35. The floor surface according to claim 27, wherein the optional polyol component is present and has an average OH-functionality of 2 to 4.

36. The floor surface according to claim 27, wherein the optional polyol component is present and has a number average molecular weight of 2000 to 10000 g/mol.

37. The floor surface according to claim 27, wherein the optional polyol component is present and selected from polyester polyols, polyether polyester polyols, polyether polyols or combinations thereof.

38. The floor surface according to claim 21, wherein the magnetic particles, magnetizable particles, or a combination of magnetic and magnetizable particles are selected from iron, iron oxides, and iron oxides mixed with other metal oxides from a transition elements group.

39. The floor surface according to claim 21, wherein the magnetic particles, magnetizable particles, or a combination of magnetic and magnetizable particles have an average particle diameter from 1 nm to 1,000 m.

Description

EXAMPLES

1. Materials Used

[0079] a. Magnetic Additive:

[0080] Ferrosilicon Cyclone 60: Atomized Ferrosilicon 15%, available from M&M Alloys

Technical Datasheet:

[0081]

TABLE-US-00001 Element Specification, % Bulk chemical composition Silicon 14-16 Iron 80 min Carbon 0.5 max Aluminium 0.04 typical Titanium 0.05 typical Physical Properties Relative density 6.7-7.1 g/ml Apparent density 3.3-4.0 g/ml Particle Size (microns) % Cumulative Passing Typical Particle Size Distribution (fine) 355 99 150 95 106 87 75 75 63 67 45 54 Limits-45 45-65 Particle Size Distribution (coarse) 355 99 150 90 106 83 75 68 63 59 45 38 Limits-45 32-42 Particle Size Distribution (Cyclone 60) 355 100 150 99 106 97 75 90 63 83 45 70 Limits-45 65-75
b. Polyurea Binder.

[0082] A two part aspartate-ester polyurea (AE-PUREA) binder composition was prepared.

AE-PUREAPart A

[0083]

TABLE-US-00002 Trade Amount Available name Composition (% wt) from Desmo- Amino functional reactant 90.92 Bayer phen NH 1420 Agitan Defoamer 1.82 Univar DF 6420 BYK Anti foaming agent 1.82 Blagden Chemicals A530 or BYK BYK Polyether modified siloxane 0.14 Blagden Chemicals 340 wetting agent or BYK Sylosiv micronized, highly porous, 2.66 Grace Davison A3 crystalline aluminosilicate Cab-o- Treated fumed silica 2.64 Univar or sil (medium surface area) Cabot TS720 Corporation

AE-PUREAPart B.

[0084]

TABLE-US-00003 Trade Amount Available name Composition (% wt) from Desmodur solvent-free aliphatic polyisocyanate 75 Bayer N3400 resin based on hexamethylene diisocyanate (HDI) Desmodur Aliphatic, HDI based prepolymer 25 Bayer XP 2599 having ether groups

[0085] A polyurea binder coating composition was prepared by blending Part A and part B of the AE-PUREA in a ratio of 1.35:1(volume) or 100:79(weight).

c. Comparative Epoxy Binder

[0086] Epoxy binder used in comparative example C-1: 3M Scotchkote Epoxy coating 162CR, commercially available from 3M. The epoxy binder is a solvent free (100% solids) epoxy coating having a water vapor permeability of 1.2 g.Math.mm.Math.m-2/24 h. For a nominal 0.5 mm thickness film, this equates to a water vapor transmission rate of 0.1 g h1 m2.

2. Test Methods

[0087] a. Water Vapor Transmission

[0088] The water vapor transmission characteristics of the compositions were assessed in accordance with ASTM D1653Standard Test Methods for Water Vapor Transmission of Organic Coating Filmsusing Test Method B(Wet Cup Method). All tests were carried out in duplicate.

b. Adhesion

[0089] The adhesion was measured via direct pull method according to ASTM 4541. The adhesion values are reported in Mpa.

3. Example 1, Reference Example Ref-1 and Comparative Example C-1

[0090] Examples 1 (a) and 1(b) were made by blending Ferrosilicon Cyclone 60 (Fe) with the AE-PUREA coating mixture in a ratio of 4.5 kg Fe to 2.52 kg of polyurea binder composition (part A+B). The composition contained 64.1% by weight of Fe based on the total weight of the coating composition). Reference examples Ref-1 (a) and Ref-1 (b) were made without magnetic particles. Comparative example C-1 was made with 3M Scotchkote Epoxy coating 162CR. The coating compositions were coated and dried at room temperature. The final coating thickness is recorded in the tables below.

[0091] Water Vapor Transmission Test:

[0092] The coatings of example 1 and Reference example Ref-1 were tested for water vapor transmission. The results are given in tables 1 to 4.

TABLE-US-00004 TABLE 1 water vapor transmission tests for Example 1 Sample Example 1 Example 1 (a) (b) Film thickness (cm) wt. wt. 0.07 Diff 0.08 Diff Start weight. 111.88 103.61 Day 1 111.84 0.04 103.570 0.04 2 111.82 0.02 103.53 0.04 3 111.82 0 103.52 0.01 6 111.78 0.04 103.49 0.03 7 111.77 0.01 103.44 0.05 9 111.75 0.02 103.39 0.05 10 111.75 0 103.37 0.02 13 111.73 0.02 103.37 0 15 111.68 0.05 103.31 0.06 17 111.67 0.01 103.3 0.01 20 111.64 0.03 103.28 0.02 22 111.59 0.05 103.25 0.03 24 111.54 0.05 103.2 0.05 27 111.51 0.03 103.16 0.04 28 111.51 0 103.15 0.01 Total wt loss/g 0.37 0.46 Time elapsed/h 672 672

[0093] The test area was 0.000963 m.sup.2.

[0094] The results are summarized in table 2:

TABLE-US-00005 TABLE 2 water vapor transmission test Ex 1: summary Ex 1 (a) Water vapour transmission 0.572 g h.sup.1 m.sup.2 rate Water vapour permeability 9.600 g .Math. mm .Math. m.sup.2/24 h Ex 1 (b) Water vapour transmission 0.711 g h.sup.1 m.sup.2 rate Water vapour permeability 13.600 g .Math. mm .Math. m.sup.2/24 h Average Water vapour permeability 11.600 g .Math. mm .Math. m.sup.2/24 h Ex 1

TABLE-US-00006 TABLE 3 water vapor transmission tests for Ref-1 Sample Ref-1 (a) Ref-1 (b) Film thickness (cm) 0.045 wt. Diff 0.035 wt. Diff Start weight. 102.04 108.25 Day 1 102.01 0.03 108.200 0.05 2 101.97 0.04 108.17 0.03 5 101.91 0.06 108.09 0.08 6 101.89 0.02 108.05 0.04 7 101.89 0 108.03 0.02 9 101.75 0.14 107.94 0.09 12 101.68 0.07 107.89 0.05 13 101.67 0.01 107.89 0 14 101.6 0.07 107.84 0.05 16 101.49 0.11 107.84 0 21 101.38 0.11 107.76 0.08 22 101.31 0.07 107.68 0.08 23 101.27 0.04 107.68 0 26 101.2 0.07 107.63 0.05 27 101.17 0.03 107.62 0.01 28 101.13 0.04 107.59 0.03 Total wt loss/g 0.91 0.66 Time elapsed/h 672 672

[0095] The test area was 0.000963 m.sup.2.

[0096] The results are summarized in the table 4:

TABLE-US-00007 TABLE 4 water vapor transmission test Ref-1: summary Ref-1 (a) Water vapour transmission 1.407 g h.sup.1 m.sup.2 rate Water vapour permeability 15.200 g .Math. mm .Math. m.sup.2/24 h Ref-1 (b) Water vapour transmission 1.020 g h.sup.1 m.sup.2 rate Water vapour permeability 8.600 g .Math. mm .Math. m.sup.2/24 h Average Water vapour permeability 11.900 g .Math. mm .Math. m.sup.2/24 h Ref-1

[0097] From the above results it can be seen that the inclusion of the ferrosilicon additive has minimal impact on the inherent water vapour transmission characteristics of the AE-PUREA coating, thus affording a magnetic and/or magnetisable floor covering composition with a high level of water vapour permeability.

Adhesion Tests:

[0098] In order to perform adhesion tests, polymer screed blocks were prepared which had been sealed on all but 1 face, using multiple coats of an epoxy coating (3M Scotchkote Epoxy Coating 162CR). The blocks were saturated with water (moisture content >95%) or left dry (moisture content >10%). Then, the final test face was coated with the respective coating composition (coating from ex 1, REF-1 and C-1).

[0099] The weight of each test panel was recorded before and after testing and the level of adhesion was measured via direct pull method according to ASTM 4541. The results are recorded in table 5. In each case the failure method was a cohesive failure within the polymer screed.

TABLE-US-00008 TABLE 5 Moisture content and adhesion Moisture content of Weight difference Level of coating screed block prior to after 21 days in 40 c. adhesion coating(%) Coating storage (g) (Mpa) >95 Ref-1 11.16 3.4 >95 Ex 1 9.81(*) 3.6 >95 C-1 2.04(*) 2.8 <10 Ex 1 1.47 3.6 (*)mean value of 2 tests

[0100] The testing shows that the moisture loss of the saturated blocks was much higher when coated with either the AE-PUREA coatings of ex 1 or of Ref-1 when compared to the comparative epoxy coating, showing that these coatings are allowing water vapor to pass through.

[0101] The results also show that the level of adhesion of the AE-PUREA coating used for the inventive method is not affected by the moisture content of the block. Also shown is that the moisture trapped in the screed by the comparative epoxy coating has lowered the cohesive strength of the polymer screed.