STORAGE-STABLE PIGMENTED FORMULATIONS CONTAINING ISOCYANATE GROUPS AND USE THEREOF

Abstract

The invention relates to storage-stable pigmented formulations containing isocyanate groups, comprising at least one pigment a., at least one component b. containing isocyanate groups, at least one wetting agent and/or dispersant c., at least one grind resin d. and optionally solvents, wherein the formulation has a viscosity increase of less than 500% after storage at 50 C. over a period of at least 3 days. The invention also relates to the production of such formulations and to the use thereof.

Claims

1. A storage-stable, isocyanate group-containing formulation comprising the components: a. at least one pigment, b. at least one isocyanate group-containing component, c. at least one wetting agent and/or dispersant, d. at least one grinding resin, and e. optionally solvents, wherein the formulation after storage at 50 C. over a period of at least 3 days exhibits a rise in viscosity of less than 500%, based on a starting viscosity of the formulation.

2. The formulation as claimed in claim 1, comprising at least one component having at least one isocyanate-reactive group, wherein a molar ratio of isocyanate groups of component b. to a sum of all isocyanate-reactive groups in the formulation is at least 6:1.

3. The formulation as claimed in claim 1, comprising a. 0.01% to 45% by weight of the at least one pigment; b. 1% to 99% by weight of the at least one isocyanate group-containing component; c. 0.01% to 20% by weight of the at least one wetting agent and/or dispersant; d. 0.1% to 30% by weight of the at least one grinding resin; and e. 0% to 80% by weight of the solvents; in each case based on a total weight of the formulation, with a sum of all constituents in the formulation not exceeding 100% by weight.

4. The formulation as claimed in claim 1, wherein the isocyanate group-containing component b. comprises 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 2-methyl-1,5-diisocyanatopentane, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3- or 1,4-bis(isocyanatomethyl)benzene, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene, 2,4- or 2,6-diisocyanatotoluene, 2,4- or 4,4-diisocyanatodiphenylmethane, 1,5-diisocyanatonaphthalene, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, 1-isocyanato-1-methyl-4(3)-isocyanatomethylcyclohexane, 2,4- or 4,4-diisocyanatodicyclohexylmethane, optionally oligomers or reaction products of these, or a mixture of at least two of these.

5. The formulation as claimed in claim 1, wherein the isocyanate group-containing component b. consists of aliphatic or cycloaliphatic isocyanates.

6. The formulation as claimed in claim 1, wherein the formulation has at least one of the following properties at room temperature: (A) a starting viscosity in a range from 1 to 200 mPas; (B) a starting viscosity in a range from 30 to 1000 mPas; (C) a starting viscosity in a range from 50 to 2000 mPas; (D) a starting viscosity in a range from 1000 to 100 000 mPas; (E) a content of isocyanate groups of less than 60% by weight, based on a total weight of the formulation, wherein the formulation has one of the properties selected from (A) to (D) in combination with property (E).

7. The formulation as claimed in claim 1, wherein the formulation exhibits a rise in particle size of less than 500% on storage at 50 C. and standard pressure over a period of 3 days, as compared to an original particle size of the formulation, based on Z average measured by dynamic light scattering, wherein the Z-average represents an intensity-weighted harmonic mean of a hydrodynamic diameter.

8. The formulation as claimed in claim 1, wherein the grinding resin d. comprises (poly)alcohols, (poly)thiols, (poly)amines, condensation resins originating from a polyaldol reaction, or a mixture of at least two of these.

9. A process for preparing an isocyanate group-containing formulation at least comprising: i. dispersing at least one pigment in at least one grinding resin in the presence of at least one wetting agent and/or dispersant, to obtain a pigment dispersion, ii. optionally diluting the pigment dispersion with solvent, iii. mixing the pigment dispersion with an isocyanate group-containing component to obtain the isocyanate group-containing formulation, wherein a ratio of a sum of isocyanate groups to a sum of all isocyanate-reactive groups in the formulation is at least 6:1.

10. A method for coating of substrate surfaces, comprising applying the formulation of claim 1 to a substrate surface to obtain a coated object.

11. A coated object obtained as claimed in claim 10.

12. An ink, comprising the formulation of claim 1.

13. A method of digital printing, comprising applying the ink of claim 12 to a substrate surface.

14. A printed object obtained using the formulation as claimed in claim 1 as an ink.

15. The object as claimed in claim 14, wherein a material of the object comprises textile, wood, plastic, glass, ceramic, carbon, metal, or a combination of at least two of these.

Description

EXAMPLES

[0240] All percentages involving weight figures always relate to percent by weight, unless otherwise indicated.

[0241] All viscosity determinations were carried out using a Physica MCR 301 (Anton Paar GmbH) with a plate/plate (diameter 40 mm) measurement geometry at 20 C. measurement temperature. All viscosity data relate to a shear rate of 500 l/s, unless otherwise indicated. The starting viscosity is defined according to the invention as the viscosity as of 1 hour after combining all of the desired components, in particular the selected components a. to e.

[0242] All particle size measurements were conducted by means of dynamic light scattering using a Zetasizer Nano ZS (Malvern Instruments Ltd.) at a temperature of 20 C. All measured values always relate to the intensity signal (Z-average).

[0243] Agglomerated pigment particles were comminuted during the production of pigment pastes. A high input of energy into the material to be ground was necessary for this. The energy can be input, for example, by means of ultrasound, rotor-stator systems or roller mills. A further method known to those skilled in the art is the grinding of the particle agglomerates in the medium in which they are to be dispersed, for example in ball or bead mills. The production of pigmented pastes was produced using a Dispermat LC30 (VMA-Getzmann GmbH) in a 125 ml double-walled temperature-controlled vessel made from stainless steel. In a first step, all materials were weighed into this vessel and mixed by hand. Subsequently, the mixture was predispersed using a dispersing disk (diameter 30 mm) for 10 minutes at 10 000 rpm until a homogeneous material (material to be ground) was formed. The dispersing tool was then replaced by a single grinding disk made from polyamide (diameter 32 mm). Zirconium oxide beads (yttrium-stabilized) having an average diameter of 0.6 to 0.8 mm were subsequently added to the material to be ground. The material to be ground was finely ground for 90 minutes at a rotational speed of 14 000 rpm with continuous cooling. After dispersion, the grinding beads were removed by filtration.

[0244] The pigmented isocyanate group-containing formulations were prepared as follows:

[0245] The pigmented paste was initially charged in a 30 ml glass vessel. The solvent (if present in the formulation) was subsequently added gradually with stirring. In a final step, the isocyanate component was added gradually with stirring. The mixture was shaken and homogenized for 30 minutes on a roller mixer (KG TRM50, IDL GmbH & Co. KG).

[0246] Materials

[0247] Organic pigments can be obtained, for example, from Clariant SE. Inorganic titanium dioxide can be obtained, for example, from Kronos Worldwide Inc. Black carbon black pigments can be obtained, for example, from Orion Engineered Carbons GmbH, which is indeed what has been done for the experimental results listed below.

TABLE-US-00001 TABLE 1 Pigments Primary Pigment particle Pigment class Density size No. Name Manufacturer color Color Index (chemical) (g/cm.sup.3) (nm) 1 Hostaperm Clariant SE Cyan P.B 15:4 Phthalocyanine 1.62 65 Blue BT-617-D 2 Inkjet Magenta Clariant SE Magenta P.V. 19 Quinacridone 1.5 70 5EB02 3 Inkjet Yellow Clariant SE Yellow P.Y. 155 Diazo 1.5 90 4GC 4 Kronos 2310 Kronos White P.W. 6 Titanium 4 *n.s. Worldwide Inc. dioxide 5 NIPex 35 Orion Black P. Bk. 7 Furnace *n.s. 31 Engineered carbon black Carbons GmbH *n.s. = not specified

[0248] Grinding resins are available from a large number of manufacturers. Suitable grinding resins can be obtained from BASF SE or from Covestro AG, among others, which is indeed what has been done for the experimental results listed below.

TABLE-US-00002 TABLE 2 Grinding resins OH Acid Class number number No. Name Manufacturer (chemical) (mg KOH/g) (mg KOH/g) 1 Laropal A81 BASF SE Condensation resin made 40 3 from urea and aliphatic aldehydes 2 Desmophen 670 Covestro AG Hydroxyl group- 141.9 2 1 containing polyester

[0249] Both grinding resins from table 2 were always used diluted to 70% by weight in butyl acetate.

[0250] Solvents are available from a large number of manufacturers. Suitable solvents can be obtained from Sigma-Aldrich, among others, which is indeed what has been done for the experimental results listed below.

TABLE-US-00003 TABLE 3 Solvent No. Solvent CAS number Manufacturer 1 Butyl acetate (BuAc) 123-86-4 Sigma-Aldrich ACS reagent, 99.5% (GC) 2 Butyl glycol acetate (BGA) 99% 112-07-2 Sigma-Aldrich

[0251] Wetting and dispersing auxiliaries (also called dispersing additives) can be obtained from various manufacturers. Among others, Byk Additives & Instruments GmbH or BASF SE offer such auxiliaries, which is indeed what has been done for the experimental results listed below.

TABLE-US-00004 TABLE 4 Wetting and dispersing additive (component c.) Sum of hydroxyl, amine Content of and acid numbers based non- Dispersing on the additive as volatile No. additive Manufacturer Structure supplied (mg KOH/g) matter (%) 1 Bykjet Byk Additives Solution of a structured 144 40 9131 & Instruments copolymer with groups GmbH having pigment affinity 2 Efka PX BASF SE Acrylate block copolymer 40 100 4701 3 Disperbyk Byk Additives High molecular weight n.s. 100 2200 & Instruments copolymer with groups GmbH having pigment affinity

[0252] Isocyanates corresponding to component b. can be obtained from various manufacturers. Among others, Covestro AG offers such isocyanates, which is indeed what has been done for the experimental results listed below.

TABLE-US-00005 TABLE 5 Isocyanates (component b.) No. Isocyanate Manufacturer NCO content (%) 1 Desmodur H Covestro AG Hexamethylene diisocyanate (HDI), monomeric aliphatic diisocyanate having a molar mass of 168, an equivalent weight of 84, an NCO content 49.7% according to DIN EN ISO 11909 and a purity of 99.5% (GC). 2 Desmodur N3400 Covestro AG Aliphatic polyisocyanate (HDI uretdione) with an NCO content of 21.8 0.7% according to DIN EN ISO 11909, a viscosity at 23 C. of 175 75 mPas according to DIN EN ISO 3219/A.3 and a content of monomeric HDI 0.3% according to DIN EN ISO 10283 3 Desmodur N3600 Covestro AG Aliphatic polyisocyanate (low-viscosity HDI trimer) with an NCO content of 23.0 0.5% according to M105-ISO 11909, a viscosity at 23 C. of 1200 300 mPas according to M014-ISO 3219/A.3 and a content of monomeric HDI 0.25% according to M106-ISO 10283.

TABLE-US-00006 TABLE 6 Examples with various NCO/OH ratios. Example/initial weight [g] Paste 1 (comparative) 2 3 4 5 6 7 8 Grinding resin d. Laropal A81 6.71 6.71 6.71 (70% in BuAc) Desmophen 670 7.49 7.49 7.49 7.49 7.49 (70% in BuAc) Pigments a. Cyan 41.15 41.15 37.26 41.15 37.26 41.15 41.15 37.26 Additive (wetting agent and/or dispersant) c. Bykjet 9131 44.03 44.03 40.1 44.03 40.1 44.03 44.03 40.1 Solvent e. BuAc/BGA 1:2 7.33 7.33 15.93 7.33 15.93 7.33 7.33 15.93 Formulation* 1 (comparative) 2 3 3 4 5 6 7 Paste composed of 1.75 2.9 3 2 1.5 1 1 1 components a. + c. e. BuAc/BGA 1:2 component e. 0.85 2.26 2.46 1.95 2.46 2.44 3.39 3.44 Desmodur N3600 2.00 5.28 5.73 4.55 5.74 5.69 7.91 8.04 component b. NCO/NCO-reactive groups 5:1 8:1 10:1 10:1 20:1 25:1 35:1 42:1 Starting viscosity [mPa*s] 127 113 74 71 69.4 67 58.4 56 Rel. change in viscosity [%], 1168.sup.a 369.sup.a 320.sup.b 323.sup.b 148.sup.b 100.sup.b 75.sup.b 71.sup.b after a, b days of storage at 50 C. Rel. change in the Z-average n.d.** n.d.** n.d.** n.d.** 17.0 12.9 15.0 12.6 [%], after 14 days of storage at 50 C. (according to the invention) No Yes Yes Yes Yes Yes Yes Yes Stable No Yes Yes Yes Yes Yes Yes Yes *Formulations 1 to 8 were prepared from pastes 1 to 8, respectively, **not determined, .sup.aafter 3 days, .sup.bafter 14 days

TABLE-US-00007 TABLE 7 further examples according to the invention Example/initial weight [g] Paste 9 10 11 12 13 14 15 16 17 18 Grinding resin d. (from table 2) Laropal A81 (70% in BuAc) 6.71 54.83 6.79 50.06 29.66 6.71 6.79 6.71 6.79 45.87 Pigments a. (from table 1) Cyan 1 37.26 37.26 37.26 Magenta 2 21.70 Yellow 3 37.77 37.77 37.77 White 4 36.70 35.7 Black 5 23.63 Wetting agent and dispersant c. (from table 4) Bykjet 9131 40.10 40.58 40.10 40.58 40.10 40.58 Efka PX 4701 13.01 3.58 Disperbyk 2200 5.03 1.65 Solvents e. (from table 3) BuAc/BGA 1:2 15.93 18.45 14.85 11.59 33.7 15.93 14.85 15.93 14.85 14.85 Formulation* 9 10 11 12 13 14 15 16 17 18 Paste 1.61 1.40 1.59 0.82 1.27 0.81 0.79 0.81 0.79 0.84 BuAc/BGA 1:2 5.52 2.58 5.52 2.75 2.62 0.92 0.92 2.75 Isocyanate b. (from table 5) Desmodur H 9.19 9.21 Desmodur N3400 8.28 8.29 Desmodur N3600 12.87 6.02 12.89 6.43 6.11 6.41 NCO/NCO-reactive groups 42:1 87:1 42:1 172:1 110:1 128:1 130:1 51:1 51:1 166:1 Starting viscosity [mPa*s] 53.4 68.2 62.9 60 55 3.2 3.0 105 103 55.1 Rel. change in the Z-average 11.6 5.5 16.8 3.2 5.4 13.7 51.21 13.4 14 8.2 [%] after 14 days of storage at 50 C. Rel. change in viscosity 35.6 45 23.1 29 50 22 33 51 83 34.8 [%] after 14 days of storage at 50 C. (according to the invention) Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Stable Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes * Formulations 9 to 18 were prepared from pastes 9 to 18, respectively Example 1 exhibits a rise in viscosity of more than 500% after three days of storage at 50 C. and is therefore not in accordance with the invention. All other examples are in accordance with the invention.