THICKENING AGENT FOR AQUEOUS SYSTEMS, FORMULATIONS CONTAINING SAME AND USES THEREOF

Abstract

The present invention relates to novel associative thickeners belonging to the category of the HEUR (Hydrophobically modified Ethoxylated URethanes), and also intermediate aqueous formulations containing such thickeners, and the final compositions, for example paint, lacquer, varnish or paper coating colour compositions.

Claims

1: A water-soluble thickening polyurethane obtained by condensation: a) of a mixture of compounds of formula (I):
R-(EO).sub.m—OH  (I), wherein: R represents a radical comprising between 2 and 5 aromatic rings, (EO).sub.m represents a chain consisting of m ethoxylated units and m represents a mean value of 8 to 12, wherein the radical R of at least one of the compounds of formula (I) represents a tristyrylphenyl group; b) of at least one poly(alkylene glycol); and c) of at least one polyisocyanate.

2: The water-soluble thickening polyurethane of claim 1, wherein the mixture of compounds of formula (I) comprises a tristyrylphenyl compound of formula (II): ##STR00008## wherein n represents an integer or decimal number of 8 to 12.

3: The water-soluble thickening polyurethane of claim 1, obtained by the condensation of: a) from 1% to 29% by weight of the at least one compound of formula (I), b) from 70% to 98% by weight of the at least one poly(alkylene glycol), and c) from 1% to 29% by weight of the at least one polyisocyanate, wherein a sum of mass percentages of a), b) and c) is equal to 100%.

4: The water-soluble thickening polyurethane of claim 1, wherein the at least one poly(alkylene glycol) is a poly(ethylene glycol) having a molecular mass of between 2,000 g/mol and 20,000 g/mol.

5: An aqueous formulation, comprising: the water-soluble thickening polyurethane of claim 1, and water.

6: The aqueous formulation of claim 5, further comprising a surface-active agent.

7: The aqueous formulation of claim 5, further comprising at least one additive selected from the group consisting of a biocide, a solvent, an anti-foaming agent, a pH regulator, a coalescent agent, and an encapsulating agent.

8: The aqueous formulation of claim 5, consisting of: 1) from 2% to 50% by weight of at least one water-soluble thickening polyurethane, 2) from 0.1% to 40% by weight of at least one surface-active agent, 3) from 10% to 93% by weight of water and 4) from 0 to 5% by weight of at least one additive selected from the group consisting of a biocide, a solvent, an anti-foaming agent, a pH regulator, a coalescent agent, and an encapsulating agent, wherein a sum of mass percentages of a), b) and c) is equal to 100%.

9: A method for thickening an aqueous composition, comprising contacting the aqueous composition with the water-soluble thickening polyurethane of claim 1, wherein the aqueous composition is selected from the group consisting of a paint, a putty, a render coating, a thick coating, a waterproof coating, a lacquer, a varnish, an ink, a slurry, a paper coating colour, a cosmetic composition and a detergent composition.

10: An aqueous composition, comprising: the water-soluble thickening polyurethane of claim 1 as an anti-sag agent, a flow & levelling agent, or both, wherein the aqueous composition is selected from the group consisting of a paint, a putty, a render coating, a thick coating, a waterproof coating, a lacquer, a varnish, an ink, a slurry, a paper coating colour, a cosmetic composition and a detergent composition.

11: A method for thickening an aqueous composition, comprising contacting the aqueous composition with the aqueous formulation of claim 5, wherein the aqueous composition is selected from the group consisting of a paint, a putty, a render coating, a thick coating, a waterproof coating, a lacquer, a varnish, an ink, a slurry, a paper coating colour, a cosmetic composition and a detergent composition.

Description

EXAMPLES

[0132] The viscosity of the test formulations or of the paint compositions is determined at different shear rate gradients: [0133] at low shear rate gradient: the Brookfield™ viscosity, which is measured using a Brookfield™ viscometer of RVT type, in the unstirred flask, at a temperature of 25° C. and at two rotational speeds of 10 and 100 revolutions per minute with the appropriate spindle. Reading is carried out after one minute of rotation. Two Brookfield™ viscosity measurements are thus obtained, which are respectively denoted μBk10 and μBk100 (mPa.Math.s), [0134] at medium shear rate gradient: the Stormer™ viscosity, denoted μS (Krebs Units) and [0135] at high shear rate gradient: the Cone Plan viscosity or ICI viscosity, denoted μl (mPa.Math.s).

[0136] Furthermore, the following are measured on a Leneta contrast card (room temperature): [0137] the flow & levelling according to the ASTM D4062 standard and [0138] the sag resistance or anti-sag according to the ASTM D4400 standard.

Example 1

[0139] This example illustrates the thickening power of the polyurethanes in simple formulations containing a binder, water and said polyurethanes, making it possible to obtain a good level of discrimination between the different tests.

[0140] It illustrates the thickening power of the two polyurethanes according to the invention (tests 1-1 and 1-2), using a compound of formula (I) in which m has a value respectively of 8 and 10 and R is tristyrylphenyl.

Test 1-1 (According to the Invention)

[0141] The polyurethanes described result from the condensation of, expressed as a percentage by weight based on the total weight of the polyurethane: [0142] 81.5% by weight of poly(ethylene glycol) with a weight-average molecular mass equal to 10,000 g/mol (PEG 10 000), [0143] 12.3% by weight of said mixture of compounds of formula (I) and [0144] 6.2% by weight of isophorone diisocyanate (IDPI).

Test 1-2 (According to the Invention)

[0145] The polyurethanes described result from the condensation of, expressed as a percentage by weight based on the total weight of the polyurethane: [0146] 80.9% by weight of poly(ethylene glycol) with a weight-average molecular mass equal to 10,000 g/mol (PEG 10 000), [0147] 13.7% by weight of said mixture of compounds of formula (I) and [0148] 5.4% by weight of isophorone diisocyanate (IDPI)

[0149] All these polyurethanes are formulated in water in the presence of a surfactant which is a C.sub.8-C.sub.10 fraction of an alkoxylated fatty alcohol (Simulsol® OX1008). The PU/surfactant/water mass ratios are shown in Table 1 below.

Test of the Thickening Power

[0150] In each of the tests 1-1 and 1-2, 140 g of Mowilith™ LDM 1871, 120 g of bi-permuted water and 32.8 g of the composition to be tested are introduced into a beaker. The Brookfield™ viscosities at 10 and 100 revolutions per minute (μ.sub.Bk10 and μ.sub.Bk100, in mPa.Math.s), the Stormer™ viscosity (μ.sub.S, in Krebs Units KU) measured with the standard module and the ICI viscosity (μ.sub.I, in mPa.Math.s) of the formulation are then measured at 25° C.

[0151] The results appear in Table 1.

TABLE-US-00001 TABLE 1 Test No. 1-1 1-2 Thickener in the form of an aqueous composition: PU/surfactant/water ratio 17.5/11.5/71 17.5/15/67.5 Test formulation: water Water: 120 g binder: Mowilith ™ LDM 1871 Binder: 140 g thickener Thickener: 32.8 g According to the invention INV INV μ.sub.Bk10 880 750 μ.sub.Bk100 864 714 μ.sub.S 80 75 μ.sub.I 200 190

[0152] The polyurethanes according to the invention indeed have a thickening power and develop the desired thickening at a low shear rate gradient.

Example 2

[0153] This example illustrates the use of a thickener according to the invention in a paint formulation, the composition of which is given in Table 2 below.

TABLE-US-00002 TABLE 2 Test No. 2-1 2-2 2-3 2-4 2-5 Preletdown Water 67 67 67 67 67 Binder 2 274 274 274 274 274 Binder 1 154 154 154 154 154 Anti-foaming agent 1 1 1 1 1 TiO.sub.2 (75 wt. % Kronos ™ 4310) 343 343 343 343 343 Stirring for 10-20 minutes Pigment mixture Water 28 28 28 28 28 Amine buffer 1 1 1 1 1 Solvent 4.5 4.5 4.5 4.5 4.5 Anti-foaming agent 1 1 1 1 1 Dispersant 1.2 1.2 1.2 1.2 1.2 Pigment extender 20 20 20 20 20 Preservative 1.6 1.6 1.6 1.6 1.6 High speed mixing for 20 min Addition of the preletdown to the pigment mixture Coalescent agent 6.5 6.5 6.5 6.5 6.5 Surfactant 2 2 2 2 2 Fungicide 2.5 2.5 2.5 2.5 2.5 Mixing for 2 minutes Addition to the preletdown Water 18.5 18.5 18.5 18.5 18.5 Open time additive 10 10 10 10 10 HEUR thickener effective at “high shear” 40 40 40 40 40 Acrysol RM825 3.4 HEUR thickener effective at “low shear” 0.5 Thickening agent to be tested 5.0 4.0 4.0 5.0 Plastic pigment 30 30 30 30 30 Wetting agent 1 1 1 1 1 Anti-foaming agent 1.5 1.5 1.5 1.5 1.5 Water 54 54 54 54 54 TOTAL (in parts) 1066 1067 1066 1066 1067

[0154] This example illustrates the viscosity at medium shear gradient (Stormer™ in KU), the flow & levelling and the sag resistance of said paint formulation using a polyurethane according to the invention (tests 2-3 and 2-4), using a compound of formula (I) comprising 8 or 10 ethylene oxide units.

[0155] At the same time, this example also illustrates a polyurethane of Acrysol RM825 type (test 2-1, reference commercial product in the field of paints) and two polyurethanes according to the patent application WO 02/102868 (tests 2-2 and 2-5), using a compound respectively comprising 3 and 25 ethylene oxide units.

[0156] For each of the tests, the viscosity μ.sub.S (in Krebs Units KU, measured with the standard module), the flow & levelling according to the ASTM D4062 standard and the sag resistance or anti-sag according to the ASTM D4400 standard were determined, according to the methods described above.

TABLE-US-00003 TABLE 3 Evaluation 2-1 2-2 2-3 2-4 2-5 OI OI INV INV OI μ.sub.s (in 113 124.3 109.4 108.8 107 Krebs Units KU) Flow & levelling 9 6 10 9 10 Sag resistance 8 20 22 16 10 OI: Outside the Invention - INV: according to the invention

Test 2-1 (Outside the Invention—Acrysol RM825)

[0157] Neither the value of the flow & levelling, nor that of the sag resistance of the paint composition comprising Acrysol RM825 are sufficient to achieve a good thickening/flow & levelling/sag resistance compromise.

Test 2-2 (Outside the Invention—3 Ethylene Oxide Units)

[0158] Although the value of the sag resistance is greater than 14, the thickening agent according to the test 2-2 does not make it possible to obtain a good compromise between viscosity at medium shear gradient (Stormer™ viscosity), on the one hand, and a flow & levelling value of greater than or equal to 9, on the other hand.

Test 2-5 (Outside the Invention—25 Ethylene Oxide Units)

[0159] Neither the value of the flow & levelling, nor that of the sag resistance of the paint composition comprising the thickening agent according to the test 2-5 are sufficient to achieve a good thickening/flow & levelling/sag resistance compromise.

Tests 2-3 and 2-4 (According to the Invention—Respectively 8 and 10 Ethylene Oxide Units)

[0160] Make it possible to obtain a formulation having a good thickening/flow & levelling/sag resistance compromise.