REDUCING BLISTER FORMATION IN POLYURETHANE CEMENTITIOUS HYBRID SYSTEMS

Abstract

A multi-component composition, in particular a three-component composition, especially for manufacture of a polyurethane cementitious hybrid flooring, including or made of: a polyol component (A) including at least one polyol and water; a hardener component (B) including at least one polyisocyanate compound; a solid component (C) including at least one hydraulic binder; and wherein at least one of the components of the multi component composition includes at least one comb polymer having a main chain including acid groups, and side chains being attached on the main chain.

Claims

1. A multi-component composition for manufacture of a polyurethane cementitious hybrid coating or flooring, comprising: a) a polyol component (A) comprising at least one polyol and water; b) a hardener component (B) comprising at least one polyisocyanate compound; c) a solid component (C) comprising at least one hydraulic binder; wherein at least one of the components of the multi component composition comprises at least one comb polymer having a main chain comprising acid groups, and side chains being attached to the main chain.

2. The composition according to claim 1 wherein the comb polymer is present in polyol component (A) and/or solid component (C).

3. The composition according to claim 1, wherein the comb polymer is present in an amount of 0.001-2 wt.-% with respect to the total weight of the composition.

4. The composition according to claim 1, wherein the comb polymer is present in polyol component (A) and with a proportion of 0.001-5 wt. % with respect to the total weight of polyol component (A).

5. The composition according to claim 1, wherein the comb polymer is present in solid state of aggregation in solid component (C).

6. The composition according to claim 1, wherein an overall weight ratio of the hydraulic binder and the comb polymer in the multi-component composition is between 10-1,000.

7. The composition according to claim 1, wherein the comb polymer comprises the following structural subunits: a) a mole fractions of a structural subunit S1 of the formula (I) ##STR00011## b) b mole fractions of a structural subunit S2 of the formula (II) ##STR00012## c) c mole fractions of a structural subunit S3 of the formula (III) ##STR00013## d) d mole fractions of a structural subunit S4 of the formula (IV) ##STR00014## where R.sup.1, in each case independently of any other, is COOM, SO.sub.2OM, OPO(OM).sub.2 and/or PO(OM).sub.2, R.sup.2, R.sup.3, R.sup.5, R.sup.6, R.sup.9, R.sup.10, R.sup.13 and R.sup.14, in each case independently of one another, are H or an alkyl group having 1 to 5 carbon atoms, R.sup.4, R.sup.7, R.sup.11 and R.sup.15, in each case independently of one another, are H, COOM or an alkyl group having 1 to 5 carbon atoms, M, independently of any other, is H.sup.+, an alkali metal ion, an alkaline earth metal ion, a di- or trivalent metal ion, an ammonium ion or an organic ammonium group, m is 0, 1 or 2, p is 0 or 1, R.sup.8 and R.sup.12, in each case independently of one another, are a C.sub.1 to C.sub.20 alkyl, cycloalkyl or alkylaryl group or are a group of the formula -[AO].sub.nR.sup.a, where A is C.sub.2 to C.sub.4 alkylene, R.sup.a is H, a C.sub.1 to C.sub.20 alkyl, cyclohexyl or alkylaryl group, and n is 2-250, R.sup.16, independently of any other, is NH.sub.2, NR.sup.bR.sup.c or OR.sup.dNR.sup.eR.sup.f, where R.sup.b and R.sup.c, independently of one another, are a C.sub.1 to C.sub.20 alkyl, cycloalkyl, alkylaryl or aryl group, or are a hydroxyalkyl group or are an acetoxyethyl (CH.sub.3COOCH.sub.2CH.sub.2) or a hydroxyisopropyl (HOCH(CH.sub.3)CH.sub.2) or an acetoxyisopropyl (CH.sub.3COOCH(CH.sub.3)CH.sub.2) group; or R.sup.b and R.sup.c together form a ring of which the nitrogen is a part, in order to construct a morpholine or imidazoline ring; R.sup.d is a C.sub.2-C.sub.4 alkylene group, R.sup.e and R.sup.f each independently of one another are a C.sub.1 to C.sub.20 alkyl, cycloalkyl, alkylaryl or aryl group or a hydroxyalkyl group, and where a, b, c and d are mole fractions of the respective structural subunits S1, S2, S3, and S4, where a/b/c/d=(0.1-0.9)/(0.1-0.9)/(0-0.8)/(0-0.8), and with the proviso that a+b+c+d is 1.

8. The composition according to claim 1, wherein the polyol component (A) comprises at least one compound selected from the list consisting of: polyhydroxy-functional natural oils or fats, polyols obtained by chemical modification of a natural oils or fats, C2 to C12 alkyl diols, glycerol, sugars, or oligomers thereof.

9. The composition according to claim 1, wherein the polyol component (A) comprises ethylene glycol, triethylene glycol, castor oil and/or a chemical modification of castor oil.

10. The composition according to claim 1, wherein the hardener component (B) comprises methylene diphenyl diisocyanate and/or polymeric methylene diphenyl diisocyanate.

11. The composition according to claim 1, wherein the polyol component (A) is formulated such that the water content is in the range of 10 to 40% by weight, and the content of one or more polyols is 35 to 55, based on the total content of component (A); and the solid component (C) is formulated such that the content of the hydraulic binder is in the range of 10 to 40% by weight, based on the total weight of component (C); and the comb polymer is present in the polyol component (A) and/or in the solid component (C) and whereby an amount of the comb polymer is 0.001-2 wt. % with respect to the total weight of the multi-component composition.

12. The composition according to claim 1, which is essentially free of lime.

13. A method for preparing a flooring, screed and/or coating, comprising mixing the components of a composition according to claim 1, and applying the composition to a substrate.

14. A cured body, obtainable by the method according to claim 13.

15. A method comprising applying a comb polymer, according to claim 1, for reducing blister formation in coating, mortar and/or screed compositions based on polyurethane and hydraulic binders.

Description

EXEMPLARY EMBODIMENTS

First Example of a Three-Component Composition for Flooring Application

[0212] Tables 1, 2 and 3 show the compositions of three components (A), (B) and (C) of a first inventive three-component composition C1 which can be used for flooring applications. Thereby, the comb polymer is present in solid component (C) in powder form.

TABLE-US-00001 TABLE 1 Polyol component (A) Compound Proportion [wt.-%] Castor oil 44 Plasticizer (e.g. butyl benzyl phthalate) 20 Triethylene glycol 5 Pigment (inorganic; e.g. Bayferrox) 6 Water 25

TABLE-US-00002 TABLE 2 Hardener component (B) Compound Proportion [wt.-%] Diphenylmethane diisocyanate (Desmodur 100 VLR10; Covesto)

TABLE-US-00003 TABLE 3 Solid component (C) Compound Proportion [wt.-%] Portland cement CEM I 52.5 31.00 Aggregates Silica Sand (0.3-0.8 mm) 34.96 Silica Sand (0.5-1.6 mm) 34.00 Comb polymer: Polycarboxylate 0.04 ether in powder form

[0213] As polycarboxylate ether, commercially available polycarboxylate ethers (PCE) were used, as marketed, for example, as products for concrete additives by Sika Schweiz AG. Specifically, a comb polymer based on a poly(methacrylic acid) main chain (R.sup.1=COOM; R.sup.2R.sup.5=Me; R.sup.3R.sup.4=R.sup.6R.sup.7H) with m=0, p=1 and R.sup.8[AO].sub.nR.sup.a where A=C2 alkylene, n=45 and R.sup.aCH.sub.3.

Second Example of a Three-Component Composition for Flooring Application

[0214] Tables 4, 5 and 6 show the compositions of three components (A), (B) and (C) of a first inventive three-component composition C2 which can be used for flooring applications. Thereby, the comb polymer is present in solid component (C) in powder form.

TABLE-US-00004 TABLE 4 Polyol component (A) Compound Proportion [wt.-%] Castor oil 43.2 Plasticizer (e.g. butyl benzyl phthalate) 20 Triethylene glycol 5 Pigment (inorganic; e.g. Bayferrox) 6 Water 25 Comb polymer: aqueous solution of a 0.8 polycarboxylate ether (40 wt.-% in water)

[0215] The chemical structure of the comb polymer used in the second example is similar to the one of the first example.

TABLE-US-00005 TABLE 5 Hardener component (B) Compound Proportion [wt.-%] Diphenylmethane diisocyanate (Desmodur 100 VLR10; Covesto)

TABLE-US-00006 TABLE 6 Solid component (C) Compound Proportion [wt.-%] Portland cement CEM I 52.5 31.00 Aggregates Silica Sand (0.3-0.8 mm) 35.00 Silica Sand (0.5-1.6 mm) 34.00

Comparative Example Compositions

[0216] A first comparative example R1 has been produced similar to example C1, however, no comb polymer has been added to the composition.

[0217] Furthermore, a second comparative example R2 has been produced similar to example C1, however, the proportion of Portland cement has been reduced to 28 wt.-% and instead of a comb polymer, 3 wt.-% hydrated lime has been added to component (C). Thus, component (C) of comparative example consists of: 28 wt.-% Portland cement, 3 wt.-% of hydrated lime (Ca(OH).sub.2), and in total 69 wt.-% of sand. The further components (A) and (B) are identical to example C1.

Using and Testing of Compositions

[0218] The components of the above mentioned compositions are mixed in a weight ratio of component A:component B:component C of 1:1:4. For mixing, component A is manually stirred for a short time (30 seconds), then part A and part B are mixed for about 1 min at 400 rpm. The mixture of A and B is then mixed with component (C) at a stirring speed of about 700 rpm for about 2 minutes.

[0219] In order to simulate flooring applications, the mixtures obtained are applied onto substrates of 0.3 m0.26 m with a frame of 5 mm height. The layer thickness of the applied mixtures on the substrates is about 4.5 mm. Afterwards, the surfaces of the mixtures are spike rolled and placed in an oven at 35 C. for about 24 hours.

[0220] After curing, the surfaces of the samples have been visually inspected for cracks and blister formation.

[0221] Thereby, the following observations were made: With the composition according to comparative example R1 (without lime and without comb polymer), numerous blisters giving rise to an uneven and inhomogeneous surface appearance could be observed. The composition according to reference example R2 (with lime) produced a smooth, leveled surface without any blisters recognizable. A similar result was obtained with inventive compositions C1 and C2. In both cases, smooth, leveled surface without any blisters could be obtained.

[0222] Thus, these results clearly show that comb polymers can be used in order to reduce or avoid blister formation in hybrid systems based on polyurethane and hydraulic binders, in particular in polyurethane cementitious hybrid systems. Especially, comb polymers represent a suitable and highly advantageous alternative for known and problematic blister reducing agents such as lime.

[0223] It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted.