Powder particulate diamide-polyolefin wax mixture

Abstract

The present invention relates to diamide-polyolefin wax mixture comprising one or more diamides (A) and one or more polyolefin waxes (B), where the diamide or diamides (A) possess a structure of the formula X.sup.1—CO—NH—Y—NH—CO—X.sup.2, in which X.sup.1 and X.sup.2 are identical or different and are linear or branched, saturated or unsaturated, optionally substituted hydrocarbon radicals having 3 to 29 carbon atoms, and Y is a divalent organic radical which is selected from the group consisting of aliphatic radicals having 2 to 26 carbon atoms, aromatic radicals having 6 to 24 carbon atoms or araliphatic radicals having 7 to 24 carbon atoms, and Y optionally comprises secondary or tertiary amino groups, and the polyolefin wax or waxes (B) carry one or more carboxyl groups and have an acid number of 3 to 50, and are homopolymers or copolymers of at least one ethylenically unsaturated olefin monomer, where the diamide or diamides (A), based on the total weight of the diamide-polyolefin wax mixture, are present in an amount of 20 wt % to less than 40 wt %, the polyolefin wax or waxes (B), based on the total weight of the diamide-polyolefin wax mixture, are present in an amount of above 60 wt % up to 80 wt %, characterized in that the diamide-polyolefin wax mixture at 25° C. is a particulate solid of defined particle size distribution, and the particles comprise both the diamide (A) and the polyolefin wax (B). The invention further relates to the preparation of the aforesaid diamide-polyolefin wax mixture, to the use thereof in liquid compositions, especially as a rheology control agent, to compositions additized accordingly, and to rheology control agents which comprise the diamide-polyolefin wax mixtures.

Claims

1. A diamide-polyolefin wax mixture comprising (A) one or more diamides which possess a structure of the formula (I)
X.sup.1—CO—NH—Y—NH—CO—X.sup.2  (I) in which X.sup.1 and X.sup.2 are identical or different and are linear or branched, saturated or unsaturated hydrocarbon radicals having 3 to 29 carbon atoms, and at least one of the radicals X.sup.1 and X.sup.2 carries at least one hydroxyl group, Y is a divalent organic radical selected from the group consisting of aliphatic radicals having 2 to 26 carbon atoms, aromatic radicals having 6 to 24 carbon atoms or araliphatic radicals having 7 to 24 carbon atoms, and Y optionally comprises secondary or tertiary amino groups; (B) one or more carboxyl-containing polyolefin waxes having an acid number of 3 to 50 mg KOH/g; and optionally (C) one or more species selected from the group consisting of (i) one or more diamides not falling within the definition of (A), and (ii) one or more inorganic salts, metal oxides or semimetal oxides, where the one or more diamides (A), based on a total weight of the diamide-polyolefin wax mixture, are present in an amount of 20 wt % to 39 wt %, the one or more carboxyl-containing polyolefin waxes (B), based on the total weight of the diamide-polyolefin wax mixture, are present in an amount of more than 60 wt % up to 80 wt %, and the one or more species (C), based on the total weight of the diamide-polyolefin wax mixture, are present in an amount of 0 to 20 wt %, wherein (a) the diamide-polyolefin wax mixture at 25° C. is a particulate solid having a particle size distribution of 5 μm≤d.sub.90≤100 μm, 1 μm≤d.sub.50≤50 μm and 0.1 μm≤d.sub.10≤20 μm, measured dry by means of laser diffraction technology, (b) the particles comprise (A) and (B) and, if (C) is present at more than 0 wt %, based on the total weight of the diamide-polyolefin wax mixture, (C) as well, and (c) a sum of the weight percentage fractions of the diamides (A) and (C)(i), based on the total weight of the diamide-polyolefin wax mixture, is less than 40 wt %.

2. The diamide-polyolefin wax mixture as claimed in claim 1, which consists of the one or more diamides (A), the one or more carboxyl-containing polyolefin waxes (B), and the one or more species (C).

3. The diamide-polyolefin wax mixture as claimed in claim 1, wherein a fraction of (A) the one or more diamides and (C)(i) the one or more diamides not falling within the definition of (A), based on the total weight of the diamide-polyolefin wax mixture, is 31 to 39 wt %.

4. The diamide-polyolefin wax mixture as claimed in claim 3, wherein a fraction of (C)(i) the one or more diamides not falling within the definition of (A), based on the total weight of the diamide-polyolefin wax mixture, is 0 to 10 wt %.

5. The diamide-polyolefin wax mixture as claimed in claim 1, wherein in the formula (I), X.sup.1 is a CH.sub.3(CH.sub.2).sub.5CH(OH)(CH.sub.2).sub.10 radical and X.sup.2 is a radical selected from the group consisting of CH.sub.3(CH.sub.2).sub.5CH(OH)(CH.sub.2).sub.10, C.sub.15H.sub.31, C.sub.17H.sub.35, C.sub.17H.sub.33, C.sub.9H.sub.19, C.sub.11H.sub.23, C.sub.7H.sub.15, and C.sub.5H.sub.11, and where at least 40 mol % of the radicals X.sup.2 are a CH.sub.3(CH.sub.2).sub.5CH(OH)(CH.sub.2).sub.10 group.

6. The diamide-polyolefin wax mixture as claimed in claim 1, wherein Y is selected from the group consisting of alkylene radicals having 2 to 8 carbon atoms and aralkylene radicals having 8 carbon atoms.

7. The diamide-polyolefin wax mixture as claimed in claim 1, wherein the one or more carboxyl-containing polyolefin waxes (B) are obtained (a) by oxidation of polyolefin waxes, (b) by oxidative degradation of polyolefin plastics, (c) by polymerization of olefins with carboxyl-containing or carboxylic anhydride-containing ethylenically unsaturated monomers, and/or (d) by grafting of carboxyl-containing or carboxylic anhydride group-containing ethylenically unsaturated monomers onto polyolefin waxes.

8. The diamide-polyolefin wax mixture as claimed in claim 1, wherein the one or more carboxyl-containing polyolefin waxes (B) is a polyethylene homopolymer or a polyethylene copolymer comprising at least 80 wt % of repeat ethylene units, based on a total weight of the polyethylene copolymer.

9. The diamide-polyolefin wax mixture as claimed in claim 1, wherein the one or more carboxyl-containing polyolefin waxes (B) have an acid number in a range from 10 to 25 mg KOH/g.

10. A process for preparing a diamide-polyolefin wax mixture as claimed in claim 1, comprising: i. mixing and homogenizing the one or more diamides (A), the one or more carboxyl-containing polyolefin waxes (B), and the one or more species (C) with one another to form a homogenized melt, cooling the homogenized melt to produce a solidified melt, iii. optionally first coarsely comminuting the solidified melt, and iv. subsequently grinding the solidified melt into a particulate diamide-polyolefin wax mixture which possesses the particle size distribution of 5 μm≤d.sub.90≤100 μm, 1 μm≤d.sub.50≤50 μm and 0.1 μm≤d.sub.10≤20 μm, measured dry by means of laser diffraction technology.

11. A rheology control agent comprising the diamide-polyolefin wax mixture as claimed in claim 1.

Description

EXAMPLES

Preparation of the Inventive Diamide-Polyolefin Wax Mixtures

Preparation of Diamide Component (A)

General Preparation Protocol

(1) Two equivalents of acid are combined with one equivalent of diamine in the liquid state. The mixture is heated to 180° C. and the water of reaction formed is separated off. When the reaction is at an end, the material is poured hot onto a stable surface. After cooling, the material is broken into pieces.

Diamide 1

(2) 842 g (2.72 mol) of 12-hydroxystearic acid were melted at 85° C. in a laboratory reactor. 197 g of an 80% solution of hexamethylenediamine in water (corresponding to 1.36 mol of hexamethylenediamine) were metered via a dropping funnel. After the end of the addition, separation of the water was commenced. The temperature was raised in 10° C. steps until it reached 180° C. When water can no longer be separated off, reduced pressure was applied for 1 hour. The progress of reaction was monitored by determination of the amine number and the acid number (in N-ethylpyrrolidone as solvent for the titration). The final value of the acid number was 1.7 mg KOH/g and the amine number was <1 mg KOH/g. After the end of the reaction, the reduced pressure was removed and the product melt was poured onto aluminum foil. When the product had cooled, it was broken into pieces.

Diamide 2

(3) 228 g (0.735 mol) of 12-hydroxystearic acid were melted at 85° C. in a laboratory reactor. 22.1 g (0.368 mol) of ethylenediamine were metered in via a dropping funnel. After the end of the addition, the reactor contents were heated at 110° C. for 1 hour. Subsequently the temperature was raised to 180° C. and water was separated off (6 hours). The progress of the reaction was monitored by determination of the amine number and the acid number (in N-ethylpyrrolidone as solvent for the titration). The final value of the acid number was 1.7 mg KOH/g and the amine number was 1.1 mg KOH/g. After the end of the reaction, the product melt was poured onto aluminum foil. When the product cooled, it was broken into pieces.

(4) The acid number (AN) was determined in accordance with DIN EN ISO 2114 (June 2002), using N-ethylpyrrolidone (NEP) as solvent for the titration. The sample (2.0 to 3.0 grams) is weighed to an accuracy of 0.1 mg into an 80 ml beaker and dissolved hot in 25 ml of NEP (around 100° C.) on a magnetic stirrer. After dissolution has taken place, 25 ml of NEP are added. The sample is placed on a magnetic stirrer, the electrode is immersed thoroughly, a few drops of phenolphthalein are added, and the system is titrated hot with 0.1N ethanolic KOH.

(5) The amine number (AmN) was determined in accordance with DIN 53176 (November 2002), using N-ethylpyrrolidone (NEP) as solvent for the titration. The sample (2.0 to 3.0 grams) is weighed to an accuracy of 0.1 mg into an 80 ml beaker and dissolved hot in 25 ml of NEP (around 100° C.) on a magnetic stirrer. After dissolution has taken place, 25 ml of NEP are added. The sample is placed on a magnetic stirrer, the electrode is immersed thoroughly, a few drops of bromophenol blue are added, and the system is titrated hot with 0.1N isopropanolic HCl.

Preparation of an Inventive Combination of Diamide Component (A) and Carboxyl-Containing Polyolefin Wax (B)

General Preparation Protocol

(6) The diamide component (A) and the polyolefin component (B) were melted together in a laboratory reactor at 150° C. and homogenized in the melt by stirring by means of a stirring rod. The melt was poured into a silicone mold to cool. The cooled material was broken into pieces, subjected to coarse preliminary grinding with a mechanical mill for around 2 minutes (Thermomix, manufacturer: Vorwerk, model TM31-1), and subsequently micronized on a fluidized-bed opposed-jet mill (model: 100-AFG, manufacturer: Hosokawa Alpine, rotary speed of classifier: 8000 rpm, internal pressure of classifier: 0.0 mbar, grinding air: 6.0 mbar; grinding gas: nitrogen).

(7) TABLE-US-00001 TABLE A Inventive examples (examples IE1-IE5) and noninventive comparative examples (comparative examples CE6-CE8) Inventive examples IE and Component A: Component B: comparative examples CE diamide 1 oxidized polyethylene wax* IE1 80 g (20%) 320 g (80%) IE 2 120 g (30%) 280 g (70%) IE 3 140 g (35%) 260 g (65%) IE 4 570 g (38%) 930 g (62%) IE 5 156 g (39%) 244 g (61%) CE6 400 g (40%) 600 g (60%) CE7 175 g (50%) 175 g (50%) CE8 284.1 g (60%) 189.4 g (40%) *having an acid number of 17 mg KOH/g to DIN EN ISO 2114 (June 2002), a density at 23° C. of 0.95 g/cm.sup.3 to EN ISO 1183-1: 2012, a dropping point of 104° C. to ASTM D-3954-94(2010), and a viscosity of 350 mPas at (120° C.) to DIN 53019-1: 2008-09.

Performance Results

(8) TABLE-US-00002 TABLE B Raw materials used Name Description Manufacturer Setalux 1756 VV-56 Acrylate binder Nuplex Resins Disperbyk-118 Wetting and dispersing BYK Chemie GmbH additive Shellsol A Aromatic hydrocarbon Overlack AG C9-C10 Xylene Overlack AG Kronos 2360 Titanium dioxide KRONOS TITAN GmbH Setamine Melamine resin Nuplex Resins US-138-BB-70 BYK-310 Surface additive BYK Chemie GmbH Epikote 828 Bisphenol A epoxy Hexion Inc. binder BYK-9076 Wetting and dispersing BYK Chemie GmbH additive BYK-A 530 Deaerating agent BYK Chemie GmbH Ti-Pure R960 Titanium dioxide Chemours Company Talkum Luzenac Talc Imerys Talc Luzenac 20M2 France EWO Heavy spar Sachtleben Chemie GmbH Epikure 3155 Polyamide epoxy Hexion Inc. hardener

Coatings Test System 1

(9) The active ingredient combinations were incorporated into the following coating formulation: Baking varnish based on Setalux 1756 VV-56/Setamine US-138-BB-70

(10) TABLE-US-00003 TABLE C Formulation Millbase: Setalux 1756 VV-65 18.6 DIS-118 0.6 Shellsol A 2.1 Xylene 2.0 Kronos 2360 25.2 Composition in powder form 1.0 Dispermat, 50° C., 30 min., 18 m/s, toothed disc Letdown: Setalux 1756 VV-65 30.0 Setamine US-138-BB-70 16.0 Shellsol A 3.0 Xylene 2.3 BYK-310 0.2 101.0

Producing the White-Pigmented Baking Varnish According to the Formula Specified in Table C

(11) The combinations in powder form were incorporated during the dispersion of the millbase (30 minutes) at an activation temperature of 50° C. After production, the varnishes were stored at room temperature (23° C.) overnight, after which the respective tests were carried out. For this purpose, the baking varnish was applied in a wet film thickness of 150 μm to steel panels, coated with a cathodic electrocoat material and measuring 10×20 cm, from Krüppel GmbH & Co. KG in Krefeld, using a four-way coatings applicator with a width of 60 mm from Byk Gardner. After a flashing time of 15 minutes at room temperature, the varnish was subsequently baked in the FDL115 paint drying oven from Binder (25 minutes; 140° C.). The drawdowns were stored for a day at room temperature (23° C.) before the respective tests took place.

Measurement Methods and Apparatus

Yellowness

(12) The yellowness was determined using the Color-Guide 45°/0° from BYK Gardner one day after the baking of the white varnish, and also one day after overbaking or UV exposure. For this purpose the YE 98 value was measured and contrasted.

UV Exposure

(13) The UV exposure for determining the effect on the yellowness was carried out on the UV unit from IST. For this purpose the varnish drawdowns were exposed 10 times at a speed of 3 m/min to gallium and mercury lamps each of 120 W/cm. This was followed by the measurement of the YE 98 values of the exposed samples.

Thermal Exposure

(14) The thermal exposure for determining the effect on the yellowness was carried out by overbaking the varnish drawdowns, already baked, at 180° C. in the FDL 115 paint drying oven from Binder for 30 minutes. This was followed by measurement of the YE 98 values of the exposed samples.

Slip Resistance

(15) The slip resistance was measured by means of a slip meter (in-house construction from Byk Gardner). In this test a 500 g weight on a felt platelet is drawn at a speed of 50 mm/s over the varnish film. A force meter determines the force which is required to do this. The reduction in the slip resistance is calculated subsequently relative to the blank sample.

Polar Component of the Surface Energy

(16) The polar component of the surface energy was determined by means of contact angle measurements on a Krüss DAS 100 contact angle instrument from Krüss in accordance with DIN 55660-1, -2 2011-12 and -5 2012-04. To calculate the polar components, the measured contact angles of five measurement liquids (water, glycerol, ethylene glycol, 1-octanol, and n-dodecane) were used.

Cross-Cut Test

(17) Varnish adhesion was assessed by means of the DIN EN ISO 2409 2013-06 cross-cut testing, using the 1 mm multi-cutter from Byk Gardner.

Interlayer Adhesion

(18) The interlayer adhesion was conducted by the pull-off test for assessing the adhesive strength in accordance with DIN EN ISO 4624, 2014-06, using the Posi Test AT-M digital from DeFelsko. For this, two films of varnish each with a wet film thickness of 150 μm were applied one above the other, with the second film being slightly colored by addition of a drop of blue paste, in order to permit better evaluation of the fracture mode. After the varnish films have been stored, after baking for a day, at room temperature (23° C.), 20 mm aluminum dies were bonded on using UHU300 2-part adhesive. The pull-off test took place 24 hours after the adhering of the dies, after storage of the samples at room temperature (23° C.). The assessment of the fracture mode (fracture of substrate to the first film/fracture of the first film to the second film/fracture of the adhesive) took place in accordance with the DIN.

(19) TABLE-US-00004 TABLE 1 Performance results on the yellowness fresh (after baking) Yellowness YE 98 (after Additive Yellowness YE 98 (fresh) 10 × UV) Control 1.45 3.00 IE1 1.41 3.16 IE2 1.53 3.52 IE3 1.69 ./. IE4 1.61 3.59 IE5 1.67 3.42 CE6 1.89 4.18 CE8 2.35 ./.

(20) From the results it is apparent that the yellowness of the fresh coating is not substantially impaired by the inventive active ingredient combinations IE1 to IE5, whereas in the case of the noninventive, comparative examples CE6 and CE8 the yellowing that occurs is stronger.

(21) From the results it is apparent that the yellowness after UV exposure is only slightly increased when using the inventive active ingredient combinations IE1, IE2, IE4, and IE5, whereas in the case of the noninventive, comparative example CE6 the yellowing that occurs is much stronger.

(22) TABLE-US-00005 TABLE 2 Performance results on the yellowness after overbaking Additive Yellowness YE 98 (after 30 min at 180° C.) Control 2.44 IE1 2.34 IE4 2.37 IE5 2.49 CE6 2.88 CE8 3.42

(23) From the results it is apparent that the yellowness after thermal exposure is not substantially altered when using the inventive active ingredient combinations IE1, IE4, and IE5, whereas in the case of the noninventive, comparative examples CE6 and CE8 the yellowing that occurs is much stronger.

(24) TABLE-US-00006 TABLE 3 Performance results on the slip resistance Additive Reduction in slip resistance in comparison to control [%] Control 0 IE2 32 IE4 29 CE6 16

(25) From the results it is apparent that the slip resistance can be reduced, advantageously, much more greatly by using the inventive active ingredient combinations IE2 and IE4 than in the case of the noninventive, comparative example CE6.

(26) TABLE-US-00007 TABLE 4 Performance results on the surface energy (polar component) determined by contact angle measurements Additive Polar component of surface energy [mN/m] Control 4.4 IE2 4.0 IE3 4.0 IE4 4.6 CE6 3.2 CE8 3.1

(27) From the results it is apparent that the polar component of the surface energy alters only slightly when using the inventive active ingredient combinations IE1 to IE4, whereas in the case of the noninventive, comparative examples CE6 and CE8 there is a marked reduction, which has adverse consequences for recoatability.

(28) TABLE-US-00008 TABLE 5 Performance results on the adhesion Adhesion after overbaking (30 min, Additive Adhesion (fresh) 180° C.) Control GT 1 GT 5 IE2 GT 1 GT 1 IE4 GT 0 GT 1 CE7 GT 1-2 GT 2 CE8 GT 2 GT 3 GT 0 very good adhesion-GT 5 poor adhesion

(29) From the results it is apparent that in the case of the inventive active ingredient combinations IE2 and IE4, varnish adhesion is better in comparison to the noninventive, comparative examples CE7 and CE8.

(30) TABLE-US-00009 TABLE 6 Performance results on the interlayer adhesion (pull-off test, AB = fracture of substrate to first layer/BC = fracture of first to second layer/XY = fracture of the adhesive) Additive AB [%] BC [%] XY [%] Control 0 80 20 IE2 95 5 0 IE3 80 15 5 IE4 90 10 0 IE5 90 10 0 CE6 70 30 0 CE7 40 60 0 CE8 0 95 5

(31) From the results it is apparent that in the case of the inventive active ingredient combinations IE2 to IE5, in comparison to the noninventive, comparative examples CE6 to CE8, there is much better interlayer adhesion (evident from the high proportion of AB).