BIO-BASED ADDITIVES BASED ON MICRONIZED RICE BRAN WAX

Abstract

The invention relates to rice bran wax oxidates that have optionally been derivatized and to micronized wax additives (MWAs) comprising optionally derivatized rice bran wax oxidate, having a volume-average particle size d.sub.50 of between 1 and 50 μm, and to the production thereof and use thereof in printing inks, paints and coatings.

Claims

1. Rice bran wax oxidates for wax additives, optionally derivatized by a method selected from the group comprising hydrolysis, alcoholysis, esterification, amidation, saponification, ethoxylation, anhydride formation and decarboxylation, having a volume-average particle size d.sub.50 of between 1-50 μm, measured to ISO 13320-1 and an acid number between 1 and 140 mg KOH/g, measured to ISO 2114.

2. Rice bran wax oxidates as claimed in claim 1, wherein the rice bran wax oxidates further have a volume-average particle size d.sub.50, measured to ISO 13320-1, of between 5-15 μm.

3. Rice bran wax oxidates as claimed in claim 1, wherein the derivatization is a saponification.

4. Rice bran wax oxidates as claimed in claim 1, wherein the acid number is between 15 and 140 mg KOH/g, measured to ISO 2114.

5. Rice bran wax oxidates as claimed in claim 1, wherein the rice bran wax oxidates further have a saponification number between 30 and 185 mg KOH/g, measured to ISO 3681.

6. Rice bran wax oxidates as claimed in claim 1, wherein the rice bran wax oxidates further have a dropping point between 70 and 110° C., measured to ISO 2176.

7. Rice bran wax oxidates as claimed in claim 1, wherein the rice bran wax oxidates have been produced with chromosulfuric acid.

8. A micronized wax additive for printing ink and paint systems, comprising one or more optionally derivatized rice bran wax oxidates as claimed in claim 1.

9. The micronized wax additive as claimed in claim 8, wherein the one or more optionally derivatized rice bran wax oxidates are present in an amount of 40-100% by weight, based on the total mass of the wax additive.

10. The micronized wax additive as claimed in claim 8, wherein the micronized wax additive has a renewable carbon index (RCI) of 80-100%.

11. A process for producing rice bran wax oxidates as claimed in claim 1, comprising grinding the components collectively in a mill down to a volume-average particle size d.sub.50 of between 1 and 50 μm, measured to ISO 13320-1.

12. The process as claimed in claim 11, wherein the mill is an impact plate mill or an airjet mill.

13. The use of a micronized wax additive as claimed in claim 8 for printing inks, coatings and paints.

14. The use as claimed in claim 13, wherein the printing inks are an offset printing ink or a flexographic printing ink, or the paints are a powder coating material or a wood paint or a 1K PUR paint system or a 2K PUR paint system.

15. The use as claimed in claim 13, wherein the micronized wax additive is used in an amount of 0.1-10.0% by weight, based on the total mass of the printing ink, coating or paint.

16. The use as claimed in claim 13, wherein the micronized wax additive is added directly or as a dispersion to the printing ink, coating or paint.

17. The use as claimed in claim 13, wherein a dispersion of a dispersant with the micronized wax additives or micronized rice bran wax oxidates is produced, and this is then added to the printing ink, coating or paint.

18. The use of the micronized wax additive as claimed in claim 8 as devolatilizing, leveling, sliding and/or dispersing auxiliary for plastics, or hydrophobizing additive in plant protection preparations.

19. (canceled)

20. (canceled)

Description

EXAMPLE 1A: FLEXOGRAPHIC PRINTING INK 1

Components:

[0054]

TABLE-US-00005 A) Uni Q MB Blue 15.3 20.0% by weight (12-111101-7.2260) (from Siegwerk) Dist. water 10.0% by weight B) Viacryl SC 175 W 40 35.0% by weight WAIP (from Cytec) Dist. water 35.0% by weight 100.0% by weight Addition of MWA 0.5% by weight/0.8% by weight Scrub test 50 strokes

EXAMPLE 1B: FLEXOGRAPHIC PRINTING INK 2

Components:

[0055]

TABLE-US-00006 A) HYDRO-X GLOSS Cyan wax-free 30.0% by weight (from Huber group) B) Viacryl SC 175 W 40 WAIP 20.0% by weight (from Cytec) Dist. water 50.0% by weight 100.0% by weight Addition of MWA 0.5% by weight/0.8% by weight

Unusual Feature:

[0056] Scrub Test with 100 Strokes

[0057] The basic scrub resistance of the printing ink is higher. In order to see differences, the number of strokes in the scrub test was therefore increased. The remaining conditions correspond to those that are also applicable to the flexographic printing ink 1.

Preparation:

[0058] Components A and B were each produced by diluting with distilled water. Subsequently, component A was initially charged in a large beaker, and component B was added gradually while stirring with a propeller stirrer. The mixture was homogenized with the propeller stirrer at 1200 rpm for at least 30 min.

[0059] The micronized wax additive was added to the printing ink base produced in this way in a concentration of 0.5% by weight or 0.8% by weight. The micronized wax additives were metered in gradually at 500 rpm in a dissolver, and then incorporated into the printing ink at 2000 rpm for 20 min.

[0060] Proofing was effected after at least 24 h (without foam) by full-area application of a wet film thickness of 6 μm to paper of the Algro Finess 80 g/m.sup.2 quality. The proof strips were tested after a drying time of 48 h.

Testing of the Micronized Wax Additive of the Invention in an Aqueous Flexographic Printing Ink:

[0061] The effect of the micronized wax additive is quantified via the gloss, coefficient of sliding friction and scrub resistance of the above-specified guide formulation. In flexographic printing inks, a high value for gloss is desirable. In the case of the coefficient of sliding friction and relative scrub resistance, defined as color abrasion, lower values are desirable in flexographic printing inks.

TABLE-US-00007 TABLE 5 Performance data of flexographic printing inks 1 and 2 Coefficient Scrub Amount Gloss of sliding resistance Sample Ink used [% 60° friction (Δ E, rel.) used used by wt.] [ ] (rel.) [ ] [ ] nSZ-MG1 Flexographic 0.5 40.7 0.16 3.30 (inv. 1) printing ink 1 0.8 39.3 0.16 3.15 mSZ-MG1 Flexographic 0.5 39.0 0.15 3.02 (inv. 2) printing ink 1 0.8 37.8 0.15 3.11 hSZ-MG1 Flexographic 0.5 40.0 0.14 2.88 (inv. 3) printing ink 1 0.8 38.2 0.14 3.03 seifSZ-MG1 Flexographic 0.5 40.1 0.15 3.11 (inv. 4) printing ink 1 0.8 38.6 0.15 3.79 Montan- Flexographic 0.5 35.4 0.16 3.26 MG1 (comp. printing ink 1 0.8 35.0 0.16 3.39 1) Amid-MG1 Flexographic 0.5 36.0 0.16 3.30 (comp. 2) printing ink 1 0.8 33.3 0.16 3.78 Kerry-MG1 Flexographic 0.5 39.8 0.21 3.1 (comp. 4) printing ink 2 0.8 37.7 0.19 3.1 nSZ-MG1 Flexographic 0.5 35.1 0.17 4.5 (inv. 5) printing ink 2 0.8 37.7 0.17 3.8 mSZ-MG1 Flexographic 0.5 37.8 0.15 3.35 (inv. 6) printing ink 2 0.8 35.6 0.16 2.82 hSZ-MG1 Flexographic 0.5 38.0 0.16 3.1 (inv. 7) printing ink 2 0.8 35.2 0.14 3.02 seifSZ-MG1 Flexographic 0.5 39.7 0.17 3.3 (inv. 8) printing ink 2 0.8 36.4 0.16 2.7 Podax-MG1 Flexographic 0.5 35.6 0.15 3.2 (comp. 3) printing ink 2 0.8 33.6 0.16 3.1 Montan- Flexographic 0.5 37.4 0.18 3.14 MG1 printing ink 2 0.8 35.7 0.18 3.05

[0062] The inventive examples from table 5 (inv. 1-4), by comparison with Montan-MG1 (comp. 1), Amid-MG1 (comp. 2), and Podax-MG1 (comp. 3), simultaneously show higher gloss and a comparable or low coefficient of sliding friction compared to the flexographic printing inks produced with the comparative waxes.

[0063] It can be inferred from FIGS. 1-4 that the rising polarity of the rice bran wax oxidates of the invention (table 5, inv. 1-8), in the series from low to higher polarity (inv. 1, 5<inv. 2, 6<inv. 3, 7˜inv. 4, 8), has a favorable influence on the sliding friction of the flexographic printing ink used. Furthermore, the gloss desired in a flexographic printing ink is higher for all inventive rice bran wax oxidates than that of Podax-MG1 (comp. 3). Kerry-MG1 (comp. 4) does show somewhat higher gloss in the flexographic printing ink, but achieves distinctly poorer values for sliding friction, such that the rice bran wax oxidates of the invention, especially those having elevated polarity (inv. 3, inv. 4, inv. 7, inv. 8), have the best properties in the flexographic printing ink.

EXAMPLE 2: OFFSET PRINTING INK

Components:

[0064]

TABLE-US-00008 A) F&E-5004 Cyan wax-free eco ink 100% by weight (from Siegwerk) B) Addition of MWA to the offset 1.5% by weight/3.0% by weight ink base

[0065] The offset ink base was admixed with the MWA and homogenized in a Speedmixer at 3000 rpm for 5 min.

[0066] Proofing was effected on an offset laboratory printing press on offset paper at an application rate of 10.0±0.5 mg/m.sup.2. Testing was effected after a drying time of 48 h in a climate-controlled room at 23° C. and a humidity of 50%.

Testing of the Micronized Wax Additive of the Invention in an Offset Printing Ink:

[0067] The effect of the micronized wax additive in offset printing inks is quantified via the coefficient of sliding friction and scrub resistance in the above-specified guide formulation. In the case of the coefficient of sliding friction and relative scrub resistance, defined as color abrasion, lower values are desirable. In addition, the micronized wax additive has an influence on gloss.

TABLE-US-00009 TABLE 6 Performance data of an offset printing ink Coefficient Scrub Amount Gloss of sliding resistance Sample used [% 60° friction (Δ E, rel.) used by wt.] [ ] (rel.) [ ] [ ] nSZ-MG1 1.5 40 0.39 5.31 (inv. 9) 3.0 29.8 0.36 3.36 mSZ-MG1 1.5 39.8 0.54 3.86 (inv. 10) 3.0 41.5 0.25 4.44 seifSZ-MG1 1.5 35.8 0.37 4.51 (inv. 11) 3.0 41.8 0.34 4.12 Montan- 1.5 43.1 0.57 13.40 MG1 (comp. 3.0 45.6 0.30 8.52 5) Amid-MG1 1.5 44.4 0.54 15.06 (comp. 6) 3.0 44.2 0.3 14.51

[0068] The inventive examples (inv. 9/10/11) from table 6, by comparison with Montan-MG1 (comp. 5) or Amid-MG1 (comp. 6), simultaneously show reduced gloss, reduced relative coefficient of sliding friction, and better scrub resistance (lower color abrasion) of the offset printing ink produced.

[0069] It can be inferred from FIG. 5 that color abrasion is distinctly reduced compared to Montan-MG1 or Amid-MG1 when the rice bran waxes of the invention are used, and hence improved scrubbing protection of the printing ink on the paper surface is achieved.

TABLE-US-00010 TABLE 7 Performance data of an offset printing ink Coefficient Scrub Amount Gloss of sliding resistance Sample used [% 60° friction (Δ E, rel.) used by wt.] [ ] (rel.) [ ] [ ] Kerry-MG1 1.5 43.6 0.24 3.0 (comp. 7) 3.0 38.4 0.17 2.5 nSZ-MG1 1.5 40.7 0.30 3.1 (inv. 12) 3.0 39.7 0.21 2.5 mSZ-MG1 1.5 43.8 0.28 3.8 (inv. 13) 3.0 42.0 0.23 3.3 hSZ-MG1 1.5 45.4 0.29 4.8 (inv. 14) 3.0 43.7 0.29 2.7 seifSZ-MG1 1.5 43.4 0.3 7.8 (inv. 15) 3.0 39.6 0.18 3.4 Podax-MG1 1.5 44.9 0.29 5.8 (comp. 8) 3.0 38.5 0.16 2.5

[0070] FIG. 6 shows the comparison of the micronized rice bran waxes available on the market (comp. 7 and 8) and of the rice bran waxes of the invention. It is apparent that the less polarized rice bran wax oxidates of the invention (inv. 12-13), even in the case of a relatively small addition of 1.5% by weight of MWA, show a very good scrub resistance (low color abrasion) that can be achieved with Podax-MG1 (comp. 8) in the case of an added amount of 3% by weight. It is found here that a low polarity range is particularly suitable in the nonpolar offset printing ink.

[0071] Thus, a certain weight and cost benefit for the offset printing ink arises especially for the less polar rice bran wax oxidates.

[0072] Moreover, the rice bran wax oxidates of the invention are notable for their particularly light color (see ION, table 3). The Kerry rice bran wax (comp. 7) is much darker.

EXAMPLE 3: AQUEOUS 1K PUR PAINT

Components:

[0073]

TABLE-US-00011 a) Bayhydrol UH 2342 91.0% by weight b) Demineralized water 3.1% by weight c) Dipropylene glycol dimethyl ether 3.1% by weight d) BYK 028 0.8% by weight e) BYK 347 0.5% by weight f) Schwego Pur 6750 5% in water 1.5% by weight 100.0% by weight Addition of MWA 2.0%/4.0% by weight

[0074] For the production of the paint, components a) to f) were mixed using a propeller stirrer in the sequence specified. The stirring time was at least 20 min at about 1000 rpm.

[0075] Micronized wax additive was added to the paint produced in this way in the dissolver at 500 rpm in a concentration of 2% or 4%. The micronized wax additive was incorporated on a dissolver at 2000 rpm for 20 min.

[0076] For production of the samples, 60 μm wet films were knife-coated onto glass plates. The test specimens, for testing of tactile properties, were produced by a three-layer (cross-coating) brush application with intermediate sanding on untreated solid wood panels.

[0077] Testing was effected after 48 h in a climate-controlled room at 23° C. and a humidity of 50%.

Testing of the Micronized Wax Additive of the Invention in an Aqueous 1-Component PUR Paint:

[0078] The effect of the micronized wax additive is quantified via the coefficient of sliding friction and scrub resistance in the above-specified guide formulation using two different grinding grades. For coefficients of sliding friction, lower values are desirable in 1K PUR paints. For scratch resistance, high values are desirable in 1K PUR paints. In addition, MWA has an influence on the gloss of the 1K PUR paint.

EXAMPLE 3A: 1K PUR PAINT, MWA WITH D.SUB.50 .OF ABOUT 12 μM

[0079]

TABLE-US-00012 TABLE 8 1K PUR paint, MWA with d.sub.50 of about 12 μm Coefficient Amount Gloss of sliding Scratch Tactile Sample used [% 60° friction resistance properties used by wt.] [ ] (rel.) [ ] [N] [ ] nSZ-MG2 2.0 73.5 0.45 0.5 A (inv. 16) 4.0 37.1 0.42 0.5 A mSZ-MG2 2.0 66.2 0.44 0.6 A (inv. 17) 4.0 29.9 0.41 0.6 A hSZ-MG2 2.0 68.4 0.41 0.5 A (inv. 18) 4.0 32.7 0.38 0.5 A seifSZ- 2.0 63.5 0.40 0.5 A MG2 (inv. 4.0 30.7 0.38 0.5 A 19) Montan- 2.0 72.0 0.45 0.5 B MG2 4.0 38.3 0.43 0.5 B (comp. 9) Amid-MG2 2.0 71.4 0.47 0.4 C (comp. 10) 4.0 32.8 0.47 0.5 C

[0080] The inventive examples (inv. 16-19) from table 8, by comparison with the comparative substances (comp. 9 and 10), have a low coefficient of sliding friction and high scratch resistance. In addition, the inventive examples have an influence on the gloss of the 1K PUR paint.

[0081] Furthermore, the inventive examples achieved an improvement in tactile impression compared to the comparative substances. This is manifested in a sensorily softer and drier surface feel, which was classified as pleasantly smooth in the blind test.

EXAMPLE 3B: 1K PUR PAINT, MWA WITH D.SUB.50 .OF ABOUT 8 μM

[0082]

TABLE-US-00013 TABLE 9 1K PUR paint, MWA with d.sub.50 of about 8 μm Coefficient Amount Gloss of sliding Scratch Tactile Sample used [% 60° friction resistance properties used by wt.] [ ] (rel.) [ ] [N] [ ] Kerry-MG1 2.0 55.4 0.4 1.05 B (comp. 11) 4.0 26.9 0.38 0.8 B nSZ-MG1 2.0 59.4 0.4 0.7 A (inv. 20) 4.0 29.8 0.38 0.7 A mSZ-MG1 2.0 52.2 0.36 0.6 A (inv. 21) 4.0 26 0.35 0.65 A hSZ-MG1 2.0 55.3 0.39 0.7 A (inv. 22) 4.0 26.7 0.35 0.7 A seifSZ-MG1 2.0 55.2 0.36 0.5 A (inv. 23) 4.0 24.4 0.35 0.75 A Montan-MG1 2.0 58.7 0.39 0.5 B (comp. 12) 4.0 25.9 0.35 0.6 B Podax-MG1 2.0 60.4 0.38 0.6 B (comp. 13) 4.0 30.3 0.35 0.65 B

[0083] The performance data were additionally evaluated using graphs.

[0084] FIGS. 7 and 8 show the coefficients of sliding friction of two 1K PUR paint batches after addition of different micronized wax additives having different grinding grades.

[0085] Sliding friction is shown for two different grinding grades. It is found that the more polar rice bran wax oxidates mSZ, hSZ and seifSZ in the aqueous 1K PUR paint reduce sliding friction compared to Montan-MG2 (comp. 9), Amid-MG2 (comp. 10), and compared to Kerry-MG1 (comp. 11) and Podax-MG1 (comp. 13).

[0086] FIGS. 9 and 10 describe the flatting effect and scratch resistance of two 1K PUR paint batches after addition of different micronized wax additives having different grinding grades.

[0087] FIG. 9 shows that the inventive systems give slightly better flatting than Podax-MG1, provided that they are used with particle sizes around 8 μm. Moreover, particularly the polar rice bran wax oxidates impart high scratch resistance to the 1K PUR paint, which does not reach the scratch resistance of Kerry-MG1 (FIG. 10), but instead offers the advantage of distinctly lighter color (see ICN, table 3) over Kerry-MG1. This advantage may be of crucial importance for colorless paint applications in order to prevent discoloration of the paint coat.

[0088] In the sensory blind test undertaken, slightly improved tactile properties of the inventive systems compared to the comparative products were found. The tactile impression was somewhat smoother and drier in terms of feel.

EXAMPLE 4: SOLVENTBORNE 2K PUR PAINT

[0089]

TABLE-US-00014 1st component: i) Desmophen 1300/75% in xylene 32.0% by weight ii) Walsroder Nitrocellulose E 510 1.5% by weight in 20% ESO iii) Acronal 4 L 10% in ethyl acetate 0.2% by weight iv) Baysilone OL 17 10% in xylene 0.2% by weight v) ethyl acetate 10.4% by weight vi) n-butyl acetate 11.0% by weight vii) methoxypropyl acetate 10.8% by weight viii)xylene 8.9% by weight 75.0% by weight 2nd component: i) Desmodur IL BA 14.2% by weight ii) Desmodur L 75 9.4% by weight iii) Xylene 1.4% by weight 25.0% by weight Addition of MWA to the paint base 2.0% by weight/4.0% by weight

[0090] The paint was produced using a propeller stirrer in the sequence specified.

[0091] The constituents of the first component were homogenized at around 1000 rpm in a suitable vessel with a propeller stirrer for several hours (until nitrocellulose dissolved). The constituents of the second component were separately homogenized in a suitable vessel with manual stirring. The paint is devolatilized in an ultrasound bath. The paint was produced by manual stirring of components 1 and 2 directly before the application of the paint to the substrates.

[0092] The micronized wax additive was added beforehand to component 1 (at 500 rpm), and incorporated in a dissolver at 2000 rpm for 20 min.

[0093] For production of the samples, 60 μm wet films were knife-coated onto glass plates. The test specimens, for testing of tactile properties, were produced by a three-layer brush application (cross-coating) with intermediate sanding on untreated solid wood panels.

[0094] Testing was effected after a drying time of 48 h in a climate-controlled room at 23° C. and a humidity of 50%.

Testing in a Solventborne 2-Component PUR Paint:

[0095] The effect of the MWA is quantified via the gloss, coefficient of sliding friction and scrub resistance in the above-specified guide formulation. For gloss performance and coefficient of sliding friction, comparatively low values are desirable in 2K PUR paints. For scratch resistance, high values are desirable in 2K PUR paints.

TABLE-US-00015 TABLE 10 Performance tests of 2K PUR paint, MWA Coefficient Amount Gloss of sliding Scratch Tactile Sample used [% 60° friction resistance properties used by wt.] [ ] (rel.) [ ] [N] [ ] Kerry-MG1 2.0 65.2 0.36 2.2 B (comp. 14) 4.0 32.3 0.34 2.45 B nSZ-MG1 2.0 72.8 0.35 2.1 A (inv. 24) 4.0 38.3 0.34 2.45 A mSZ-MG1 2.0 67.4 0.36 1.7 A (inv. 25) 4.0 36.1 0.34 1.9 A hSZ-MG1 2.0 59.3 0.34 2.0 A (inv. 26) 4.0 30.6 0.32 2.15 A seifSZ-MG1 2.0 62.5 0.36 2.05 A (inv. 27) 4.0 28.9 0.32 2.55 A Montan- 2.0 61.9 0.33 2.05 C MG1 (comp. 4.0 30 0.32 2.4 C 15) Podax-MG1 2.0 84.6 0.32 1.9 B (comp. 16) 4.0 49.1 0.32 1.7 B Kerry-MG2 2.0 69.1 0.39 2.8 B (comp. 17) 4.0 32.1 0.37 3.0 B nSZ-MG2 2.0 73.3 0.4 2.8 A (inv. 28) 4.0 36.6 0.38 3.0 A mSZ-MG2 2.0 70 0.38 2.65 A (inv. 29) 4.0 36.7 0.39 3.1 A hSZ-MG2 2.0 65.4 0.36 2.45 A (inv. 30) 4.0 31.2 0.35 2.9 A seifSZ-MG2 2.0 64.9 0.36 0.85 A (inv. 31) 4.0 33.3 0.34 1.85 A Montan- 2.0 71.9 0.38 2.35 C MG2 (comp. 4.0 37.6 0.4 2.65 C 18)

[0096] The inventive examples (inv. 24-31) from table 10, compared to the comparative substances (comp. 14-18), show lower gloss or a flatting effect with a simultaneously low coefficient of sliding friction, high scratch resistance, and pleasant tactile properties which are important for wood paints.

[0097] In addition, the performance tests were evaluated using graphs.

[0098] FIG. 11 shows that the 2K PUR paints with added rice bran wax oxidates of the invention have lower gloss than the paints with added Podax-MG1, and Podax-MG1 has less of a flatting effect than the rest of the MWAs.

[0099] It is apparent from FIGS. 11 to 13, which show the gloss, sliding friction and scratch resistance of the 2K PUR paints with different added wax additives in the form of graphs, that Kerry-MG1 and Kerry-MG2 do have a somewhat stronger flatting effect than the rice bran wax oxidates of the invention, and are also comparable in terms of scratch resistance with the less polar rice bran waxes nSZ-MG1 or nSZ-MG2 (FIGS. 12 and 13), but it is apparent from FIG. 12 that they have somewhat poorer sliding friction by virtue of the higher coefficient of sliding friction. Moreover, Kerry-MG1 and Kerry-MG2 are distinctly darker (characterized by a distinctly higher iodine color number; see FIG. 14), and so the nonpolar rice bran wax oxidates in the nonpolar solvent-based 2K PUR paint have the best combination of desirable properties.