Polymeric-inorganic nanoparticle compositions, manufacturing process thereof and their use as lubricant additives

Abstract

The invention relates to polymeric-inorganic nanoparticle compositions and preparation processes thereof. The invention also relates to an additive and lubricant composition comprising these polymeric-inorganic nanoparticle compositions, as well as to the use of these polymeric-inorganic nanoparticle compositions in an oil lubricant formulation to improve tribological performance, in particular to improve anti-friction performance on metal parts.

Claims

1. A polymeric-inorganic nanoparticle composition, obtainable by milling a mixture, the mixture comprising one or more nanoparticle compound (A) and one or more polymer compound (B), (A) wherein the one or more nanoparticle compound is selected from the group consisting of metal oxide nanoparticle, metal nitride nanoparticle, metal carbide nanoparticle, and mixtures thereof; or the group consisting of oxidized metal nitride nanoparticle, oxidized metal carbide nanoparticle, and mixtures thereof; or the group consisting of non-metal oxide nanoparticle, or the group consisting of multi or single layered carbonous structures, multi or single walled nanotubes, carbon fullerenes, graphene, carbon black, graphite, and mixtures thereof; or mixtures of the foregoing nanoparticle compounds; and (B) wherein the one or more polymer compound is obtainable by polymerizing a monomer composition comprising: a) one or more functional monomer selected from the list consisting of: a1) hydroxyalkyl (meth)acrylates; a2) aminoalkyl (meth)acrylates and aminoalkyl (meth)acrylamides; a3) nitriles of (meth)acrylic acid and other nitrogen-containing (meth)acrylates; a4) aryl (meth)acrylates, where the acryl residue in each case can be unsubstituted or substituted up to four times; a5) carbonyl-containing (meth)acrylates; a6) (meth)acrylates of ether alcohols; a7) (meth)acrylates of halogenated alcohols; a8) oxiranyl (meth)acrylate; a9) phosphorus-, and/or boron containing (meth)acrylates; a10) sulfur-containing (meth)acrylates; a11) heterocyclic (meth)acrylates; a12) maleic acid and maleic acid derivatives; a13) fumaric acid and fumaric acid derivatives; a14) vinyl halides; a15) vinyl esters; a16) vinyl monomers containing aromatic groups; a17) heterocyclic vinyl compounds; a18) vinyl and isoprenyl ethers; a19) methacrylic acid and acrylic acid, and c) the reaction product of one or more ester of (meth)acrylic acid and one or more hydroxylated hydrogenated polybutadiene having a number-average molecular weight (M.sub.n) of 500 to 10,000 g/mol, and wherein the weight ratio of the one or more nanoparticle compound (A) to the one or more polymer compound (B) is from 20:1 to 1:5.

2. The polymeric-inorganic nanoparticle composition according to claim 1, wherein the hydroxylated hydrogenated polybutadiene of at least one of the one or more ester c) has a number-average molecular weight (M.sub.n) of from 1,500 to 2,100 g/mol, and wherein the one or more polymer compound B have a molar degree of branching f.sub.branch of from 1 to 4 mol %.

3. The polymeric-inorganic nanoparticle composition according to claim 1, wherein the monomer composition further comprises as component b) one or more alkyl (meth)acrylate monomer wherein each of the alkyl group of the one or more alkyl (meth)acrylate monomer independently is linear, cyclic or branched and comprises from 1 to 40 carbon atoms, and wherein the one or more polymer compound B have a molar degree of branching f.sub.branch of from 1.5 to 3 mol %.

4. The polymeric-inorganic nanoparticle composition according to claim 3, wherein one or more of the alkyl (meth)acrylate monomer having the linear, cyclic or branched alkyl group which comprises the 1 to 40 carbon atoms independently is b1) of formula (I): ##STR00004## wherein R is hydrogen or methyl, R.sup.1 means a linear, branched or cyclic alkyl residue with 1 to 8 carbon atoms, or b2) of formula (II): ##STR00005## wherein R is hydrogen or methyl, R.sup.2 means a linear, branched or cyclic alkyl residue with 9 to 15 carbon atoms, or b3) of formula (III): ##STR00006## wherein R is hydrogen or methyl, R.sup.3 means a linear, branched or cyclic alkyl residue with 16 to 40 carbon atoms.

5. The polymeric-inorganic nanoparticle composition according to claim 1, wherein the one or more polymer compound (B) is obtainable by polymerizing a monomer composition comprising components a) and c), and optionally component b), and wherein the one or more polymer compound (B) has a weight-average molecular weight (M.sub.w) of 10,000 to 1,000,000 g/mol.

6. The polymeric-inorganic nanoparticle composition according to claim 1, wherein the weight ratio of the one or more nanoparticle compound (A) to the one or more polymer compound (B) is from 10:1 to 1:2.

7. The polymeric-inorganic nanoparticle composition according to claim 3, wherein the one or more polymer compound (B) is obtainable by polymerizing a monomer composition comprising: a2) 0.5 to 5% by weight of an aminoalkyl (meth)acrylamide as first component a) based on the one or more polymer compound (B); a16) 5 to 20% by weight of a vinyl monomer containing aromatic groups as second component a) based on the one or more polymer compound (B); b1) 25 to 60% by weight of an alkyl (meth)acrylate monomer of formula (I) as first component b) based on the one or more polymer compound (B); b2) 1 to 10% by weight of an alkyl (meth)acrylate monomer of formula (II) as second component b) based on the one or more polymer compound (B); and c) 25 to 60% by weight of an ester of a (meth)acrylic acid and a hydroxylated hydrogenated polybutadiene having a number-average molecular weight (M.sub.n) of from 500 to 10,000 g/mol, as component c) based on the one or more polymer compound (B); wherein the amounts of all monomers of the monomer composition sum up to 100% by weight.

8. The polymeric-inorganic nanoparticle composition according to claim 1, wherein the nanoparticle compound (A) comprises hexagonal boron nitride (hBN) nanoparticle.

9. A method for manufacturing a polymeric-inorganic nanoparticle composition as defined in claim 1, the method comprising the steps of: (a) Providing one or more nanoparticle compound (A); (b) providing one or more polymer compound (B); (c) providing a solvent (C); (d) combining at least the one or more nanoparticle compound (A) and the one or more polymer compound (B) to obtain a mixture, the one or more polymer compound (B) and the solvent (C) to obtain a mixture; and (e) milling the mixture.

10. An additive for a lubricant composition wherein the additive comprises the polymeric-inorganic nanoparticle composition according to claim 1.

11. A formulation comprising: (a) a base oil; and (b) a polymeric-inorganic nanoparticle composition according to claim 1.

12. The formulation according to claim 11, wherein the base oil is selected from the list consisting of an API Group I base oil, an API Group II base oil, an API Group III base oil, an API Group IV base oil and an API Group V base oil, or a mixture of one or more of these base oils.

13. The formulation according to claim 11, comprising (i) 40 to 95% by weight of base oil and (ii) 5 to 60% by weight of the polymeric-inorganic nanoparticle composition, based on the total weight of the formulation.

14. The formulation according to claim 11, comprising (i) from 50 to 99.99% by weight of base oil and (ii) from 0.01 to 50% by weight of the polymeric-inorganic nanoparticle composition, based on the total weight of the formulation.

15. The polymeric-inorganic nanoparticle composition according to claim 3, wherein one or more of the alkyl (meth)acrylate monomer having the linear, cyclic or branched alkyl group which comprises the 1 to 40 carbon atoms independently is b1) of formula (I): ##STR00007## wherein R is hydrogen or methyl, R.sup.1 means a linear, branched or cyclic alkyl residue with 1 to 3 carbon atoms, or b2) of formula (II): ##STR00008## wherein R is hydrogen or methyl, R.sup.2 means a linear, branched or cyclic alkyl residue with 12 to 14 carbon atoms, or b3) of formula (III): ##STR00009## wherein R is hydrogen or methyl, R.sup.3 means a linear, branched or cyclic alkyl residue with 16 to 20 carbon atoms.

16. The polymeric-inorganic nanoparticle composition according to claim 1, wherein the one or more polymer compound (B) is obtainable by polymerizing a monomer composition comprising components a) and c), and optionally component b), and wherein the one or more polymer compound (B) has a weight-average molecular weight (M.sub.w) of from 100,000 to 800,000 g/mol.

17. The polymeric-inorganic nanoparticle composition according to claim 1, wherein the weight ratio of the one or more intercalation compound (A) to the one or more polymer compound (B) is from 4:1 to 2:1.

18. The polymeric-inorganic nanoparticle composition according to claim 3, wherein the one or more polymer compound (B) is obtainable by polymerizing a monomer composition comprising: a2) from 0.5 to 5% by weight of N-(3-dimethyl-aminopropyl)methacrylamide, as first component a) based on the one or more polymer compound (B); a16) from 5 to 20% by weight of a styrene, as second component a) based on the one or more polymer compound (B); b1) from 25 to 60% by weight of methyl methacrylate and/or butyl methacrylate, as first component b) based on the one or more polymer compound (B); b2) from 1 to 10% by weight of lauryl methacrylate, as second component b) based on the one or more polymer compound (B); and c) from 25 to 60% by weight of a macromonomer derived from the reaction of an ester of a (meth)acrylic acid and a hydroxylated hydrogenated polybutadiene having a number-average molecular weight (M.sub.n) of from 1,500-5,000 g/mol, as component c) based on the one or more polymer compound (B); wherein the amounts of all monomers of the monomer composition sum up to 100% by weight.

19. The formulation according to claim 11, comprising (i) 70 to 90% by weight of base oil and (ii) from 10 to 30% by weight of the polymeric-inorganic nanoparticle composition, based on the total weight of the formulation.

20. The formulation according to claim 11, comprising (i) from 75 to 99.99% by weight of base oil and (ii) from 0.1 to 25% by weight of the polymeric-inorganic nanoparticle composition, based on the total weight of the formulation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For the purpose of better illustrating the advantages and properties of the claimed polymeric-inorganic particles object of the invention, a graph is attached as a non-limiting example:

(2) FIG. 1 is a diagram showing the friction reduction in % in boundary regime.

EXPERIMENTAL PART

(3) The invention is further illustrated in detail hereinafter with reference to examples and comparative examples, without any intention to limit the scope of the present invention.

Abbreviations

(4) C.sub.1 AMA C.sub.1-alkyl methacrylate (methyl methacrylate; MMA) C.sub.4 AMA C.sub.4-alkyl methacrylate (n-butyl methacrylate) C.sub.12-14 AMA C.sub.12-14-alkyl methacrylate DMAPMAA N-3-Dimethylaminopropylmethacrylamid f.sub.branch degree of branching in mol % MMA methyl(meth)acrylate MA-1 macroalcohol (hydroxylated hydrogenated polybutadiene Mn=2,000 g/mol) MM-1 macromonomer of hydrogenated polybutadiene MA-1 with methacrylate functionality (M.sub.n=2,000 g/mol) M.sub.n number-average molecular weight M.sub.w weight-average molecular weight NB3020 Nexbase® 3020, Group III base oil from Neste with a KV.sub.100 of 2.2 cSt NB3043 Nexbase® 3043, Group III base oil from Neste with a KV.sub.100 of 4.3 cSt NB3060 Nexbase® 3060, Group III base oil from Neste with a KV.sub.100 of 6.0 cSt PDI polydispersity index, molecular weight distribution calculated via M.sub.w/M.sub.n MTM Mini Traction Machine equipment

(5) Synthesis of a Hydroxylated Hydrogenated Polybutadiene (Macroalcohol) MA-1

(6) The macroalcohol was synthesized by anionic polymerization of 1,3-butadiene with butyllithium at 20-45° C. On attainment of the desired degree of polymerization, the reaction was stopped by adding propylene oxide and lithium was removed by precipitation with methanol. Subsequently, the polymer was hydrogenated under a hydrogen atmosphere in the presence of a noble metal catalyst at up to 140° C. and 200 bar pressure. After the hydrogenation had ended, the noble metal catalyst was removed and organic solvent was drawn off under reduced pressure to obtain a 100% macroalcohol MA-1.

(7) Table 2 summarizes the characterization data of MA-1

(8) TABLE-US-00002 TABLE 2 Characterization data of used macroalcohol. M.sub.n [g/mol] Hydrogenation level [%] OH functionality [%] MA-1 2,000 >99 >98

(9) Synthesis of Macromonomer MM-1

(10) In a 2 L stirred apparatus equipped with saber stirrer, air inlet tube, thermocouple with controller, heating mantle, column having a random packing of 3 mm wire spirals, vapor divider, top thermometer, reflux condenser and substrate cooler, 1000 g of the above-described macroalcohol are dissolved in methyl methacrylate (MMA) by stirring at 60° C. Added to the solution are 20 ppm of 2,2,6,6-tetramethylpiperidin-1-oxyl radical and 200 ppm of hydroquinone monomethyl ether. After heating to MMA reflux (bottom temperature about 110° C.) while passing air through for stabilization, about 20 mL of MMA are distilled off for azeotropic drying. After cooling to 95° C., LiOCH.sub.3 is added and the mixture is heated back to reflux. After the reaction time of about 1 hour, the top temperature has fallen to ˜64° C. because of methanol formation. The methanol/MMA azeotrope formed is distilled off constantly until a constant top temperature of about 100° C. is established again. At this temperature, the mixture is left to react for a further hour. For further workup, the bulk of MMA is drawn off under reduced pressure. Insoluble catalyst residues are removed by pressure filtration (Seitz T1000 depth filter).

(11) Table 3 summarizes the MMA and LiOCH.sub.3 amounts used for the synthesis of macromonomer MM-1

(12) TABLE-US-00003 TABLE 3 Macroalcohol, MMA and catalyst amounts for the transesterification of the macromonomer. Macromonomer Macroalcohol Amount MMA [g] Amount LiOCH.sub.3 [g] MM-1 MA-1 500 1.5

(13) Preparation of Amine- and Macromonomer-Containing Polymer Compound (B) According to the Invention

(14) As described above, the polymer weight-average molecular weights (M.sub.w) were measured by gel permeation chromatography (GPC) calibrated using polymethylmethacrylate (PMMA) standards. Tetrahydrofuran (THF) is used as eluent.

(15) Example Polymer 1 (P1):

(16) 85 grams of Nexbase 3020, 85 grams of Berylane 230SPP, 140 grams of macromonomer, 107 grams of butyl methacrylate, 28 grams of styrene, 13 grams of lauryl methacrylate, 8 grams of dimethylaminopropylmethacrylamide, and 1 grams of n-dodecylmercaptan were charged into a 2-liter, 4-necked round bottom flask. The reaction mixture was stirred using a C-stirring rod, inerted with nitrogen, and heated to 115° C. Once the reaction mixture reached the setpoint temperature, 0.9 grams of tertbutyl-2-ethyleperoxyhexanoate were fed into the reactor over 3 hours. 0.5 grams of 2,2-di-(tert-butylperoxy)-butane were added in 30 minutes and 3 hours after the previous feed. The reaction was allowed to stir for one hour, and then an additional 132 grams of Nexbase 3020 were added to the reactor and allowed to mix for 1 hour. The polymer obtained has a weight-average molecular weight (M.sub.w) of 260,000 g/mol (PMMA standard).

(17) Preparation of Comparative Polymer

(18) Comparative Example Polymer 2 (P2):

(19) 200 grams of Nexbase 3043, 11.34 grams of n-3-dimethylaminopropylmethacrylamid (DMAPMAA), 272.21 grams of lauryl methacrylate (C.sub.12-14 AMA, 5.53 grams of n-dodecyl mercaptan (n-DDM) 5.53 grams of 2-Ethylhexylthioglycolate (TGEH) were charged into 2 liter, 4-necked round bottom flask. The reaction mixture was stirred using a C-stirring rod, inerted with nitrogen, and heated to 90° C. Once the reaction mixture reached the setpoint temperature, 2.83 grams t-butylperoctoate was fed into the reactor over 2 hours. After 2 hours the mixture was heated up to 100° C. and after reaching the setpoint 1.42 grams of t-butylper-2-ethylhexanoate and 1.13 grams of tert-butylperpivalate were fed in one hour. Residual monomer was measured by gas chromatography to ensure good monomer conversion. The polymer obtained has a weight-average molecular weight (M.sub.w) of 10,500 g/mol (PMMA standard).

(20) For the examples P1 and P2, the monomer components add up to 100%. The amount of initiator and chain transfer agent is given relative to the total amount of monomers. Table 4 below shows the monomer composition and reactants to prepare the polymers P1 and P2, as well as their final characterization.

(21) TABLE-US-00004 TABLE 4 Composition, weight-average molecular weight and PDI of polymers according to the present invention C.sub.4 C.sub.1 C.sub.12-14 DMAP MM-1 styrene AMA AMA AMA MA f.sub.branch Initiator CTA M.sub.w Ex [wt %] [wt %] [wt %] [wt %] [wt %] [wt %] — [%] [%] [g/mol] PDI P1 38.49 11.01 42.0 0.24 4.88 3.38 1.8 0.75 0.40 260,000 2.85 P2 — — — — 96.0 4.0 — 1.9 3.9 10,500 1.61

(22) Preparation of Polymeric-Inorganic Nanoparticle Concentrates According to the Invention

(23) Inventive Example Dispersion IE1:

(24) 2 g of hBN particles are given into a solution of 16 g Nexbase 3043 oil including 2 g of P1 while this mixture is treated with ultrasound (ultrasound processor UP400S with 400 Watt, 24 kHz with Ti-sonotrode). After the addition is finished the dispersion is treated for 120 minutes. The particle size distribution (measured in Tegosoft DEC oil using dynamic light scattering equipment, LA-950, Horiba Ltd., Japan) shows a d50 value of 267 nm (d99: 337 nm).

(25) Preparation of Polymeric-Inorganic Nanoparticle Concentrates as Comparative Example

(26) Comparative Example Dispersion CE1:

(27) 2 g of hBN particles are given into a solution of 16.3 g Nexbase 3043 oil including 1.7 g of P2 while this mixture is treated with ultrasound (ultrasound processor UP400S with 400 Watt, 24 kHz with Ti-sonotrode) for 120 minutes, respectively. The particle size distribution (measured in Tegosoft DEC oil using dynamic light scattering equipment, LA-950, Horiba Ltd., Japan) shows a d50 value of 479 nm.

(28) The table 5 below summarizes the compositions of the inventive dispersions (IE) according to the invention and the comparative dispersions (CE). The listed weight percentages are based on the total weight of the different compositions.

(29) TABLE-US-00005 TABLE 5 Comparison of dispersions according the present invention hBN in Polymer (B) Dispersant Nexbase ® Example wt % Dispersant content in wt % in wt % 3043 in wt % IE1 10 P1 5 10 80 CE1 10 P2 5 8.3 81.7

(30) Dynamic Light Scattering (DLS)

(31) The particle size distribution was measured in Tegosoft DEC oil using the dynamic light scattering equipment LB-500 produced by Horiba Ltd.

(32) Dynamic light scattering (DLS) is a technique in physics that can be used to determine the size distribution profile of small particles in suspension or polymers in solution. This equipment can be used to measure the particle size of dispersed material (inorganic nanoparticles or polymeric spheres, e.g.) in the range from 3 nm to 6 μm. The measurement is based on the Brownian motion of the particles within the medium and the scattering of incident laser light because of a difference in refraction index of liquid and solid material.

(33) The resulting value is the hydrodynamic diameter of the particle's corresponding sphere. The values d50, d90 and d99 are common standards for discussion, as these describe the hydrodynamic diameter of the particle below which 50%, 90% or 99% of the particles are within the particle size distribution. The lower these values, the better the particle dispersion. Monitoring these values can give a clue about the particle dispersion stability. If the values increase tremendously, the particles are not stabilized enough and may tend to agglomerate and sediment over time resulting in a lack of stability. Depending on the viscosity of the medium, it can be stated, that a d99 value of <500 nm (e.g. for Nexbase base oil) is an indication for a stable dispersion as the particles are held in abeyance over time.

(34) For the sake of comparison lubricating formulations are always compared based on the same content of inorganic nanoparticles. Therefore, formulations named with “−1” correspond to formulations having an inorganic nanoparticle concentration of 1 wt %, based on the total weight of lubricating formulation. Similarly “−2” corresponds to a concentration of 0.5 wt %, “−3” corresponds to a concentration of 10 wt %, “−4” corresponds to a concentration of 5 wt % and “−5” corresponds to a concentration of 0.1 wt %.

(35) Determination of the Reduction in Friction Via Mini Traction Machine (MTM)

(36) The coefficient of friction was measured using a Mini traction machine named MTM2 from PCS Instruments following the test method described in Table 4 below. SRR refers to the Sliding Roll Ratio. This parameter was maintained constant during the 2 hours test and is defined as (U.sub.Ball−U.sub.Disc)/U wherein (U.sub.Ball−U.sub.Disc) represents the sliding speed and U the entrainment speed, given by U=(U.sub.Ball+U.sub.Disc)/2. Stribeck curves for each sample were measured according to protocol in Table 6.

(37) TABLE-US-00006 TABLE 6 Protocol to measure the Stribeck curves Method 1 Test Rig MTM 2 from PCS Instruments Disc Highly polished stainless Steel AISI 52100 Disc diameter 46 mm Ball Highly polished stainless Steel AISI 52100 Ball diameter 19.05 mm Speed 5-2500 mm/s Temperature 100° C. Load 30N SRR 50%

(38) According to MTM Method 1, the friction coefficient was recorded over the complete range of speed for each blend and a Stribeck curve is obtained. The friction tests were performed according to these conditions for the formulations listed in Table 7 and results thereof are disclosed in Table 8 below. The listed weight percentages are based on the total weight of the different formulations.

(39) TABLE-US-00007 TABLE 7 Formulations according to the invention Particle Inventive concentration examples Comparative in Dispersion examples formulation NB3043 IE1 Dispersion CE1 Formulation IE1-1   1 wt % 90 wt % 10 wt % Formulation   1 wt % 90 wt % 10 wt % CE1-1 Formulation IE1-2 0.5 wt % 95 wt %  5 wt % Formulation 0.5 wt % 95 wt %  5 wt % CE1-2

(40) To express in % the friction reduction, a quantifiable result can be expressed as a number and is obtained by integration of the friction value curves using the obtained corresponding Stribeck curves in the range of sliding speed 5 mm/s-60 mm/s using the trapezoidal rule. The area corresponds to the “total friction” over the selected speed regime. The smaller the area, the greater the friction-reducing effect of the product examined. The percentage friction reductions were calculated by using the values of the reference oil Nexbase® 3043, which generates an area of friction of 6.32 mm/s. Positive values indicate a decrease of friction coefficients. Values in relation to the reference oil are compiled in the table 8 below (see also FIG. 1).

(41) TABLE-US-00008 TABLE 8 Friction reduction in boundary regime for the formulations according to the invention compared to base oil Friction area from Reduction of Example 5-60 mm/s Friction in % NB3043 6.32 reference Formulation IE1-1 1.43 77 Formulation CE1-1 4.44 30 Formulation IE1-2 1.58 75 Formulation CE1-2 4.50 29

(42) The results are shown in table 8, the results of the calculated total friction in the range of sliding speed 5 mm/s-60 mm/s clearly show that the inventive example IE1 has a much better effect with regard to the reduction in friction than the corresponding comparative example and reference NB3043 oil. NB3043 is the reference base oil.

(43) The results obtained were not foreseeable from the available documentation of the state of the art. The results show that the dispersibility and plays an important role with polymer P1

(44) Dispersion Stability Test by Visual Appearance

(45) A stability test was conducted for each sample by diluting a small amount of concentrate to a 5 wt %, 1 wt % and 0.1 wt % solution of the polymeric-inorganic nanoparticle composition based on the total weight of the different formulations. The dilution was prepared by blending one concentrate chosen from inventive example IE1 or comparative example CE1 in a 10 mL glass vial at room temperature. For example, 0.5 grams of inventive example IE1 were mixed with 4.5 grams of NB3043 to obtain a 1 wt % solution of polymeric-inorganic nanoparticles.

(46) Each dilution was stored at room temperature. The vials were checked after 1 week, 4 weeks and 3 months for signs of sedimentation or other instabilities. The stability of the dispersion was judged using two factors: first, the amount of sedimentation was classified into 4 categories: o: no sedimentation (no particles settled at the bottom of the vial); Δ: minor sedimentation (some particles start to settle at the bottom of the vial); +: moderate sedimentation (thin layer at the bottom of the vial), and +++: nearly complete sedimentation (almost all particles have settled and supernatant is almost clear). Second, it was controlled that no phase separation has occurred. An instable dispersion can show almost no sedimentation of nanoparticles, but a phase separation which results in a clear and completely particle-free upper part and a higher concentration of nanoparticles in the lower part of the dilution. Therefore, we classified the phase separation into two categories: −: no phase separation visible and +: phase separation occurred.

(47) The results obtained as shown in Table 9 below.

(48) TABLE-US-00009 TABLE 9 Results from the stability check of the polymeric-inorganic nanoparticle compositions according to the invention Inventive examples Comparative examples Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation IE1-3 IE1-4 IE1-1 IE1-5 CE1-3 CE1-4 CE1-1 CE1-5 NB3043 − 50 wt % 90 wt % 99 wt % − 50 wt % 90 wt % 99 wt % Dispersion IE1 100 wt % 50 wt % 10 wt % 1 wt % Dispersion CE1 100 wt % 50 wt % 10 wt % 1 wt % Particle 10 wt % 5 wt % 1 wt % 0.1 wt % 10 wt % 5 wt % 1 wt % 0.1 wt % concentration in formulation Sedimentation ∘ ∘ ∘ ∘ ∘ ∘ ∘ + (after 1 week) Phase separation − − − − − − − + (after 1 week) Sedimentation ∘ ∘ ∘ ∘ + + + + (after 4 weeks) Phase separation − − − − + + + + (after 4 weeks) Sedimentation + ∘ ∘ ∘ +++ +++ +++ +++ (after 3 months) Phase separation − − − − + + + + (after 3 months) — Judgement of sedimentation: ∘: no sedimentation (no particles settled at the bottom of the vial) Δ: minor sedimentation (some particles start to settle at the bottom of the vial) +: moderate sedimentation (thin layer at the bottom of the vial) +++: nearly complete sedimentation (almost all particles have settled and supernatant is almost clear) — Judgement of phase separation: −: no phase separation visible +: phase separation occured