DISPERSANTS

Abstract

The present invention relates to dispersants based on polyamines or polyimines containing side chains based on two or more poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) and side chains based on alkyl acid (B).

Claims

1. A dispersant based on polyamines or polyimines containing side chains based on two or more poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) and side chains based on alkyl acids (B).

2. The dispersant according to claim 1, wherein the poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) are homopolymers but have different chain lengths.

3. The dispersant according to claim 2, wherein the poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) are selected from the group of linear hydroxy-C.sub.1-6-alkylenecarboxylic acids and lactones.

4. The dispersant according to claim 3, wherein the poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) are δ-valerolactone or ε-caprolactone.

5. The dispersant according to claim 4, wherein the alkyl acids (B) are selected from the group of acetic, methoxyacetic, propionic, pentanoic, hexanoic, caprylic, capric, lauric, ricinoleic, stearic acid and hydroxystearic acid.

6. The dispersants according to claim 5, wherein the polyimine is a polyethyleneimine.

7. The dispersant according to claim 6, wherein the mean molecular weight (Mw) of the polyethyleneimine is between 200 and 600000 g/mol.

8. The dispersant according to claim 7, wherein the dispersant has an acid number of <10 mg KOH/g.

9. The dispersant according to claim 8, wherein the dispersant has a ratio of acid number to amine number of >10.

10. A method for preparing dispersants according to claim 1, comprising the reaction of polyamines or polyimines with at least two or more polymers based on poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) and alkyl acids (B), wherein an amidation of alkyl acids (B) with the polyamines or polyimines takes place.

11. The method according to claim 10, wherein the molar ratio of the sum total of poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) and alkyl acids (B) to primary amino groups of the polyamines or polyimines is less than 1.

12. The method according to claim 11, wherein the molar ratio between the two or more different poly(oxy-C.sub.1-6-alkylenecarbonyl) chains (A) and the alkyl acids (B) is between 90/10 and 10/90.

13. The method according to claim 12, wherein the polymers are prepared separately or in situ by polymerization of the poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) and then used for the reaction with polyamines or polyimines and alkyl acids (B).

14. The method according to claim 13, wherein the poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) are linear hydroxy-C.sub.1-6-alkylenecarboxylic acids or lactones.

15. The method according to claim 14, wherein the poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) are ε-valerolactone or ε-caprolactone.

16. The method according to claim 15, wherein the poly(oxy-C.sub.1-6-alkylenecarbonyl) compounds (A) are homopolymers having different chain lengths.

17. The method according to claim 13, wherein the alkyl acids (B) are selected from the group of acetic, methoxyacetic, propionic, pentanoic, hexanoic, lauric, ricinoleic or stearic acid.

18. The method according to claim 17, wherein the alkyl acids (B) correspond to the polymerization initiator for preparation of the polymers.

19. The method according to claim 13, wherein the polyimine is a polyethyleneimine.

20. The method according to claim 19, wherein the mean molecular weight (Mw) of the polyethyleneimine is between 200 and 600000 g/mol.

21. The composition comprising a particulate solid and a dispersant according to claim 1.

22. A method of making an article selected from the group consisting of dispersions, millbases, inks or printing ink, the method comprising the step of making the article with the composition according to claim 21.

Description

[0088] The present invention will now be more particularly described with reference to examples. Alternative embodiments of the present invention are obtainable analogously.

[0089] 1. Preparation of Polymers

[0090] For the preparation of the dispersant of the invention, the polymers are first prepared either separately (Examples 1 and 2) or in situ (Example 3) by ring-opening polymerization. The numbers 1:9 and 1:6 in brackets are the molar ratios of the components and hence represent the chain length of the polymers.

[0091] Polymer 1: Lauric Acid and ε-Caprolactone (1:9)

[0092] A four-neck flask provided with a stirrer, thermometer, reflux condenser and nitrogen inlet tube is initially charged with lauric acid (1 mol) and ε-caprolactone (9 mol), and heated up to 100° C. while stirring under N.sub.2 gas. Subsequently, zirconium butoxide (0.5%) is added and the mixture is heated further to 160° C. under N.sub.2 gas. The mixture is stirred at this temperature for about 4 hours.

[0093] A solid that was yellow in color was obtained. The reaction had a conversion of more than 95%.

[0094] Polymer 2: Lauric Acid and ε-Caprolactone (1:6)

[0095] A four-neck flask provided with a stirrer, thermometer, reflux condenser and nitrogen inlet tube is initially charged with lauric acid (1 mol) and ε-caprolactone (6 mol), and heated up to 100° C. while stirring under N.sub.2 gas. Subsequently, zirconium butoxide (0.5%) is added and the mixture is heated further to 160° C. under N.sub.2 gas. The mixture is stirred at this temperature for about 4 hours.

[0096] A solid that was yellow in color was obtained. The reaction had a conversion of more than 95%.

[0097] Polymer 3: Lauric Acid and ε-Caprolactone, In Situ (1:9) and (1:6)

[0098] A four-neck flask provided with a stirrer, thermometer, reflux condenser and nitrogen inlet tube is initially charged with lauric acid (1 mol) and ε-caprolactone (3 mol), and heated up to 100° C. while stirring under N.sub.2 gas. Subsequently, the zirconium butoxide is added and the mixture is heated further to 160° C. under N.sub.2 gas. The mixture is stirred at this temperature (about 4 hours) until the conversion of ≧90% is attained. The temperature is reduced to 105° C., and lauric acid (1 mol) and ε-caprolactone (6 mol) are again initially charged under N.sub.2 gas and the mixture is stirred for 3 hours. Subsequently, zirconium butoxide (0.5%) is added again and the mixture is heated further to 160° C. under N2 gas. The mixture is stirred at this temperature for about 4 hours.

[0099] A solid that was yellow in color was obtained. The reaction had a conversion of more than 95%.

[0100] 2. Synthesis of Dispersants

[0101] Dispersant 1 (D1)

[0102] Polymer 1 (0.25 mol) and polymer 2 (0.25 mol) were heated to 65° C. Polyethyleneimine (1.5 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.5 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid.

[0103] Dispersant 2 (D2)

[0104] Polymer 1 (0.30 mol) and polymer 2 (0.30 mol) were heated to 65° C. Polyethyleneimine (1.5 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.4 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid.

[0105] Dispersant 3 (D3)

[0106] Polymer 1 (0.30 mol) and polymer 2 (0.30 mol) were heated to 65° C. Polyethyleneimine (1.5 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.3 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid.

[0107] Dispersant 4 (D4)

[0108] Polymer 1 (0.275 mol) and polymer 2 (0.275 mol) were heated to 65° C.; polyethyleneimine (1.5 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.45 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid.

[0109] Dispersant 5 (D5)

[0110] Polymer 1 (0.25 mol) and polymer 2 (0.25 mol) were heated to 65° C.; polyethyleneimine (1.5 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.4 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid.

[0111] Dispersant 6 (D6)

[0112] Polymer 1 (0.225 mol) and polymer 2 (0.225 mol) were heated to 65° C.; polyethyleneimine (1.5 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.45 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid.

[0113] Dispersant 7 (D7)

[0114] Polymer 1 (0.225 mol) and polymer 2 (0.225 mol) were heated to 65° C.; polyethyleneimine (1.5 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.55 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid.

[0115] Dispersant 8 (D8)

[0116] Polymer 3 (0.5 mol) was heated to 65° C.; polyethyleneimine (1.50 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.4 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid.

[0117] Dispersant 9 (D9)

[0118] Polymer 3 (0.6 mol) was heated to 65° C.; polyethyleneimine (1.50 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.4 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid.

[0119] Dispersant 10 (D10)

[0120] Polymer 3 (0.55 mol) was heated to 65° C.; polyethyleneimine (1.50 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.35 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid.

[0121] In the course of storage at room temperature for up to two months, no changes in the amber viscous liquid were detected in any of the dispersants of the invention.

[0122] 3. Production of Comparative Dispersants

[0123] Comparative Dispersant 1 (CD1)

[0124] Polymer 1 from Example 1 (1.10 mol) was heated to 65° C.; polyethyleneimine (1.50 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.50 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of a yellow solid.

[0125] Comparative Dispersant 2 (CD2)

[0126] Polymer 1 (0.45 mol) was heated to 65° C.; polyethyleneimine (1.50 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.55 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product was obtained in the form of an amber viscous liquid, but solidifies over time.

[0127] Comparative Dispersant 3 (CD3)

[0128] Polymer 1 (0.50 mol) was heated to 65° C.; polyethyleneimine (1.50 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.7 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product crystallizes out.

[0129] Comparative Dispersant 4 (CD4)

[0130] Polymer 1 (0.60 mol) was heated to 65° C.; polyethyleneimine (1.50 mol based on primary amines, Lupasol PR 8515, MW 2000, from the BASF SE Company) and lauric acid (0.4 mol) were added. The mixture was stirred at 160° C. and 15 mbar for 4 hours. On cooling, the product crystallizes out.

[0131] 4. Determination of Acid Number and Amine Number

[0132] 4.1 Acid Number

[0133] The degree of conversion is determined via a volumetric determination of the acid number (AcN). The acid number indicates the mg of KOH required to neutralize the free acids present in 1 g of product. The method was established on the basis of DGF C-V 2, Ph.EUR. 2.5.1, ISO 3682, ASTM D 974, DIN EN ISO 2114.

[0134] To determine the acid number, the sample is dissolved in a suitable solvent and then the free acids present are titrated with potassium hydroxide solution. The solvent used is a mixture of ethanol and toluene in a ratio of 1:1. Other possible solvents are, for example, ethanol or isopropanol, the alternative solvents having no effect on the result of the test method. The solvents or solvent mixtures used should merely be neutralized in advance using phenolphthalein, in order to avoid distortion of the analysis result. Useful titrants include 0.5 N potassium hydroxide solution, 0.1 N potassium hydroxide solution and 0.02 N potassium hydroxide solution. A useful solvent for the potassium hydroxide solution is water or ethanol. The indicator employed for the attainment of the changeover point may, for example, be a 1% phenolphthalein solution in ethanol. For the actual procedure, the sample to be analyzed is weighed accurately to 0.1 wt %. Subsequently, about 50-100 ml of the neutralized solvent are added and the sample, if necessary, is dissolved with gentle heating. After addition of the phenolphthalein solution, titration is performed with standard potassium hydroxide solution until there is a permanent color change. For evaluation, the following calculation formula is used:

[00001]$\mathrm{Acid}.Math..Math.\mathrm{number}.Math.\left[\mathrm{mg}.Math..Math.\mathrm{KOH}.Math.\text{/}.Math.g\right]=\frac{V\times M.Math..Math.\mathrm{KOH}\times N}{E}$

[0135] V=consumption of the titrant [ml]

[0136] N=normality of titrant

[0137] E=sample weight [g]

[0138] M KOH=molar mass of KOH

[0139] 4.2 Amine Number

[0140] The amine number can be determined by means of a method based AOCS Tf lb-64, Afnor T-73-204, DIN EN ISO 4315. To determine the amine number, the sample is dissolved in a suitable solvent and then the free amines present are titrated with a standardized acid using an indicator. The amine number (AmN) indicates the mg of KOH corresponding to the basicity of 1 g of sample. A corresponding amount of sample is weighed accurately to 0.1 wt % directly into an

[0141] Erlenmeyer flask or beaker and dissolved with about 100 ml of ethanol or isopropanol, optionally while heating. After adding a few drops of bromophenol blue solution, titration is done with the hydrochloric acid solution until the color changes from blue to yellow.

[00002]$\mathrm{AmN}.Math.\left[\mathrm{mg}.Math..Math.\mathrm{KOH}.Math.\text{/}.Math.g\right]=\frac{\mathrm{ml}.Math..Math.\mathrm{consumed}\star m\star 56.109\star f}{E}$

[0142] AmN=amine number

[0143] E=weight in g

[0144] 56.109=molar mass of KOH

[0145] m=molarity of the hydrochloric acid solution

[0146] f=factor of the hydrochloric acid solution

TABLE-US-00001 TABLE 1 Acid number and amine number AcN AmN (mgKOH/g) (mgKOH/g) Polymer 1 63.4 — Polymer 2 45.7 — Polymer 3 54.5 — D1 1.5 147 D2 1.6 135 D3 1.6 136 D4 1.6 138 D5 1.6 151 D6 1.6 157 D7 1.6 151 D8 1.6 145 D9 1.6 130 D10 1.6 141 CD 1 1.8 131 CD 2 1.9 141 CD 3 2.1 121 CD 4 1.7 129

[0147] 5. Performance Evaluation

[0148] For the production of the pigment concentrates and color pastes, the following general method parameters were fixed and established:

TABLE-US-00002 Milling machine: Speed Mixer DAC 150 FVZ (Hauschild Company) Milling vessels: FLACKTEK vessels max. 100 Balls: Zirconium silicate balls (diameter: 0.6-0.8 mm) Amount of pigment concentrate: For organic 50.0 g pigments and carbon black: For inorganic 30.0 g pigments: Milling time: Organic pigments and carbon black: 5 min Inorganic pigments: 3 min Speed: 2000 rpm for the pigment concentrate 3000 rpm for the color paste

[0149] The following pigments were used:

[0150] Bayferrox 3920 from the Lanxess Company with Color Index PY42

[0151] Heliogen Blue L7085 from the BASF Company with Color Index PB15:3

[0152] Color black FW 200 from the Evonik Company with Color Index PBk 7

[0153] 5.1 Pigment Concentrates

[0154] For the performance assessment, pigment concentrates according to the formulations from Table 2 were produced.

TABLE-US-00003 TABLE 2 Inorganic Organic Carbon pigment pigment black concentrate concentrate concentrate Butyl acetate 2.6 g 7.7 g 7.2 g (solvent) Dispersant or 1.8 g 2.5 g 7.1 g comparative dispersant TEGO ® VariPlus 20.6 g 27.3 g 26.2 g LK (resin) Bayferrox 3920 25.0 g Heliogen Blue 12.5 g L7085 Color Black FW 9.5 g 200 Sum total 50.0 g 50.0 g 50.0 g

[0155] All raw materials from Table 2, except for the particular pigment, are first weighed in a vessel, then homogenized with one another. Thereafter, the pigment is added and mixed with the raw materials.

[0156] For milling of the particular pigment, balls were added to the mixture and milling was done by stirring.

[0157] All the ground pigment concentrates were then cooled and filtered.

[0158] 5.2 Color Paste

[0159] For the production of the color paste, an aromatics-free alkyd binder from Brillux with the product name Impredur 840 was used as a base varnish. Table 3 shows the mixing ratios between the base varnish and the pigment concentrate.

TABLE-US-00004 TABLE 3 Heliogen Blue L Bayferrox 3920 Color Black FW 7085 color paste color paste 200 color paste Base varnish 20 g 20 g 20 g Organic pigment 0.64 g concentrate Inorganic pigment 0.80 g concentrate Carbon black 0.84 g concentrate

[0160] First of all, the base varnish is weighed out in a Flacktek vessel. The Speed Mixer was used to mix the base varnish and the pigment concentrate at 3000 rpm for 1 min. The color pastes produced were used for further application tests.

[0161] 5.3 Application Tests

[0162] 5.3.1 Rub-Out Test:

[0163] For the “rub-out test”, the color pastes were applied to a plate with a Leneta 150 μm drawdown bar. After drying time of 5 minutes, the ‘rub-out test’ is done, which consists in rubbing the applied varnish. The color values are determined correspondingly before and after the rubbing and the ΔE (delta E) or color differences are calculated, which is used as a measure for the distance between two colors and correspondingly the “rub-out test” enables an evaluation with regard to the pigment stabilization performance of the additive. In the reporting of color differences, the value of 1 or less than 1 denotes a difference which is not perceived by the human eye.

[0164] 5.3.2 Color Strength

[0165] The colorimetric values were determined with an X-Rite Model SP 62 spectrometer. The color strength F was determined using the following measurement:

[00003]$F=\frac{{\left(100-Y\right)}^2}{2.Math.Y}$ [0166] Y=the reflection capacity of the wavelength at absorption maximum

[0167] The color strength gives a statement with regard to the color intensity, which can vary according to the pigment, but also according to the dispersant and milling process. The higher the color strength, the better the dispersant.

[0168] 5.3.3 Viscosity of the Pastes

[0169] For the rheological viscosity profiles, the RheoStress 1 from Thermo HAAKE was used. The dynamic viscosity curves were determined at a temperature of 25° C.±0.5 with the parallel plate measurement geometry. The lower the viscosity of the paste, the better the dispersant.

[0170] The results are compiled in Tables 4, 5 and 6.

TABLE-US-00005 TABLE 4 Heliogen Blue L 7085 color paste Paste viscosity Pigment Dispersants F ΔE (mPa*s) Heliogen D1 47.9 0.62 7533 Blue L D2 46.45 0.44 6382 7085 D3 45.21 0.64 9362 D4 46.55 0.48 7068 D5 46.68 0.43 7014 D6 47.35 0.33 6887 D7 46.87 0.47 7920 D8 46.57 0.36 7576 D9 47.63 0.34 7301 D10 47.68 0.33 4313 CD 1 49.07 0.56 8247 CD 2 45.98 0.51 9111 CD 3 46.08 0.48 7424 CD 4 48.01 0.35 3423

TABLE-US-00006 TABLE 5 Bayferrox 3920 color paste Paste viscosity Pigment Dispersant F ΔE (mPa*s) Bayferrox D1 6.36 0.64 6996 3920 D2 6.53 0.24 6981 D3 6.27 0.75 9229 D4 5.97 1.23 10140 D5 6.53 0.21 8747 D6 5.86 1.58 13000 D7 5.64 1.06 11380 D8 6.67 0.43 8156 D9 6.7 0.44 7121 D10 6.78 0.21 6945 CD 1 6.63 0.44 7295 CD 2 6.45 0.35 7777 CD 3 6.53 0.41 6110 CD 4 6.85 0.45 6975

TABLE-US-00007 TABLE 6 Color Black FW 200 color paste Paste viscosity Pigment Dispersant F ΔE (mPa*s) Color D1 142.79 0.09 1079 Black FW D2 141.14 0.1 1219 200 D3 142.11 0.28 923 D4 141.98 0.28 942 D5 140.86 0.19 1000 D6 140.96 0.15 1164 D7 141.54 0.21 1034 D8 142.95 0.09 1002 D9 141.24 0.16 997 D10 142.57 0.08 984 CD 1 141.57 0.38 1002 CD 2 137.85 0.57 3073 CD 3 142.08 0.33 1171 CD 4 142.38 0.14 867

[0171] Based on conducted application tests, it was concluded that the dispersants of the invention do not differ significantly from those from the prior art (comparative dispersants). The color strength, the paste viscosity and delta E values of the dispersants of the invention barely differ from those from the prior art.

[0172] In summary, it can be stated that the dispersants of the invention can on the whole be used as solvent-free additives for production of various pigment concentrates. The dispersants of the invention are suitable both for organic and inorganic pigments. Use with carbon black-containing pigments is likewise possible. Furthermore, the polymers (A) prepared in situ in particular can dispense with further time-consuming and costly production steps.