WO2008017679A1

WO2008017679A1 - Process for the preparation of metal oxide organosols and the use of said organosols in the nanoparticle enrichment of coating resins

Info

Publication number: WO2008017679A1
Application number: PCT/EP2007/058198
Authority: WO
Inventors: Franciscus Hubertus Maria Stappers
Original assignee: Akzo Nobel Coatings International B.V.
Priority date: 2006-08-10
Filing date: 2007-08-07
Publication date: 2008-02-14

Abstract

Process for the preparation of a metal oxide organosol in a non-aqueous phase which comprises the following steps: a) Preparing a solution of a quaternary compound in a composition liquid at room temperature, said liquid composition comprising a compound selected from the group consisting of an organic solvent containing ester groups, a reactive diluent, and a low viscous binder resin; b) Adding an aqueous composition comprising a metal oxide sol to said solution wherein a mixture is formed having an aqueous phase and a non-aqueous phase; c) Separating the aqueous phase from the non-aqueous phase; and d) Collecting the non-aqueous phase comprising the metal oxide organosol.

Description

PROCESS FOR THE PREPARATION OF METAL OXIDE ORGANOSOLS AND THE USE OF SAID ORGANOSOLS IN THE NANOPARTICLE ENRICHMENT OF COATING RESINS

The present invention relates to a process for the preparation of metal oxide organosols and the use of the organosols in the nanoparticle enrichment of polymer resins or binders. In general, a metal oxide organosol is more compatible to organic solvents than an aqueous metal oxide sol.

Metal oxide organosols, in particular silica organosols are known in the art. An organosol is a dispersion of nanoparticles in an organic solvent. More precisely the dispersion should be colloidal with a particle size small enough to not scatter visible light, considerably to the human eye, which for most particle- solvent combinations means smaller than 10-100 nm Metal oxide organosols can be used in lubricating oils and greases, as fillers for rubber products, or in coatings, e.g. to increase surface hardness, to increase friction, or to absorb radiation (e.g. IR or UV radiation). Various processes are known for the preparation of metal oxide organosols.

In US 2,692,863 a process is disclosed wherein a quaternary ammonium base is added to an aqueous silica sol. Also, a brine-immiscible organic liquid is added to the aquasol. As a result, a precipitate is formed which contains silica particles. The precipitate can be filtered off and the sol can be redispersed in organic solvents.

In US 2,786,042 another process is disclosed for the preparation of silica sols. In this process the silica sol particles are modified by adding a strong alkali salt of a hydrocarbon-substituted silanolate. In US 3,660,301 a process is described for the preparation of an organosol. In this process a quaternary ammonium compound is solved in a non-polar, aliphatic organic solvent, mixing the solution with an aqueous silica sol, adding a cosolvent, separating the organic layer from the aqueous layer, and removing the cosolvent by heat.

The present invention relates to a process for preparing a metal oxide organosol, which process is simpler and shows a higher yield than the known prior art processes. This new process for the preparation of a silica organosol in a non-aqueous phase comprises the steps of:

- Preparing a solution of a quaternary compound in a composition liquid at room temperature, said liquid composition comprising a compound selected from the group consisting of an organic solvent containing ester groups, a reactive diluent, and a low viscous binder resin;

- Adding an aqueous composition comprising a metal oxide sol to said solution wherein a mixture is formed having an aqueous phase and a nonaqueous phase;

- Separating the aqueous phase from the non-aqueous phase; - Collecting the non-aqueous phase comprising the metal oxide organosol.

It was found that the thus obtained metal oxide organosol in the non-aqueous phase can be used very effectively in the preparation of a resin loaded with metal oxide nanoparticles. In this process, if the liquid compound is an organic solvent, the organosol/solvent mixture is mixed with the resin, optionally the solvent is stripped from the thus obtained mixture, and a transparent resin containing metal oxide nanoparticles is obtained. If the liquid compound is a reactive diluent, the diluent can be reacted with other another reactant to form a resin to obtain a transparent resin containing metal oxide nanoparticles. When the liquid compound is a low viscous binder resin a transparent resin containing metal oxide nanoparticles is obtained directly.

By using this process, fully transparent resins can be obtained with a nanoparticles loading in the range from 0 to 60 wt.%, based upon the weight of the resin. It was found that this process is in particular suited for the preparation in a simple way of resin compositions having a high loading with nanoparticles, e.g. a particle loading in the range of 5 - 50 wt.% based upon the weight of the resin, more preferred in the range of 15 - 35 wt.%.

In a preferred embodiment, the quaternary compound is selected from the group consisting of quaternary ammonium compounds and quaternary phosphonium compounds.

In a further preferred embodiment the quaternary compound can be represented by the following chemical formula (I): R¹R²R³R⁴X⁺ - Y^" (I) wherein:

R¹ represents hydrogen or a C1 - C30 alkyl or aryl group or modifications thereof;

R² represents hydrogen or a C1 - C30 alkyl or aryl group or modifications thereof;

R³ represents hydrogen or a C1 - C30 alkyl or aryl group or modifications thereof;

R⁴ represents hydrogen or a C1 - C30 alkyl or aryl group or modifications thereof; - X represents Nitrogen (N) or Phosphor (P);

Y represents a monovalent negatively charged countergroup; and at least one of groups R¹ - R⁴ represents a C6 - C22 alkyl group.

In a preferred embodiment three of groups R¹ - R⁴ represent a C_nH_n+I group, where n = 1 , 2, 3 or 4, and one group represents a C16 - C20 group. The following embodiments are most preferred: - R₁ = R₂ = CH₃ and R₃ = R₄ = C₈H₁₇

R₁ = R₂ ⁼ R₃ ⁼ CH₃ and R₄ ⁼ C-i₆H₃₃ R₁ = R₂ ⁼ R₃ ⁼ CH₃ and R₄ ⁼ C-i₆H₃₃ — C-_IsH₃₇ R₁ = R₂ ⁼ CH₃, R₃ ⁼C-i2H25 — C₁₄H29 and R₄ ⁼ CεHs

In general these quaternary compounds can also be referred to as quaternary fatty acids.

The negatively charged countergroup can be, e.g, a negatively charged counterion like F^", Cl^", Br^", or I^", or an acetate or sulphate group.

Examples of quaternary compounds that can be used for the purpose of the present invention include Arquad® quaternary ammonium products ex Akzo Nobel, bis(trimethylhexyl)dimethyl-phosphonium tosylate, and thethyl(octadecyl)-phosphonium bromide.

For the purpose of the present application, metal oxides also include oxides of rare earth metals and oxides of metalloids. In a preferred embodiment the metal oxide organosol is a CeO₂, SiO₂, ZnO, TiO₂, or indium tin oxide (ITO) based organosol. Most preferred is the use of a SiO₂, CeO₂, TiO₂ or ITO based organosol.

For the purpose of the present application, a compound liquid at room temperature is a compound that has a viscosity in the range from 1 to 1000 mPaS at room temperature. Said liquid compound is selected from the group consisting of organic solvents, reactive diluents, and a low viscous binders. In a preferred embodiment, the organic solvent is an ester. In the most preferred embodiment, the organic solvent is an acetic acid ester. It was found that the process according to the present invention is best performed in a slightly polar aprotic organic solvent having a polarity in the range of ε° = 0.5 to 0.6 measured according to Snyder's Elutropic Solvent Strength Scale. Examples of polar aprotic solvents that can be used in the process according to the present invention include Shellsoll D40, Shellsoll D60, and butyl acetate.

Without being bound to any theory, it is envisaged that when the aqueous metal oxide sol is contacted with the solution of the quaternary compound in the organic solvent, the (surface of the) sol particles absorbs the quaternary compound wherein the polarity of the particles is reduced. As a result, the sol particles migrate to the organic solvent. The organic solvent (containing the surface modified metal oxide sol) and the aqueous phase can be separated by phase separation or any other known technique for the separation of immiscible liquid phases of liquid phases having a different boiling point. However, phase separation is preferred since this technique will leave any water soluble impurities in the aqueous phase, resulting in a highly pure organic solvent containing the metal oxide sol particles. Moreover, phase separation is less expensive, faster and simpler than other techniques involving one or several distillation steps. However, purification by distillation in general will result in an even higher purity organosol/solvent mixture

Examples of aqueous metal oxide sols that can be used in the process of the present invention are Bindzil and Nyacol® ex Akzo Nobel N. V., Snowtex® ex Nissan Chemicals Ltd., Klebosol® ex Clariant, Rhodigard® W200 ex Rhodia, S5-300B ex Millenium Chemicals, or VP AdNano® ITO ex Degussa. Typically, the aqueous metal oxide sols have a number average particle diameter, as determined using a dynamic light scattering method, of between 1 and 1 ,000 nm, a solids content of 10 to 50 wt%. Preferably, the number average particle diameter is between 1 and 150 nm, more preferably in the range between 5 and 50 nm. It is envisaged that the aqueous metal oxide sols may comprise bimodal or polymodal particle size distributions.

It was found that when an metal oxide organosol is prepared in accordance with the present invention, only a relatively small amount of stabilizer is needed to keep the organosol dispersed in the organic solvent, typically in the range form 5 to 50 wt.%, based on particles. Also, the thus prepared organosol can be dispersed in other organic solvents. The small amount of stabilizer is advantageous since a high amount might have a negative impact of the properties of any product that contains the thus obtained organosol. The process according to the present invention is also a very simple, fast, and low energy consuming and therefore a very economic process for the preparation of an organosol. It is not necessary to use any cosolvent or further additives that need to be recycled either from the aqueous of organic phase. Further, the surface modified organosol obtained by the process of the present invention can be used as a starting product for the preparation of metal oxide particles with specific surface groups. In such preparation, the quaternary groups present on the surface of the metal oxide particles are replaced by the specific surface groups.

It was found that the organosol prepared in accordance with the present invention is highly compatible with a wide variety of organic resins used in coating compositions, (printing) ink formulations, adhesive tackifiers, resin- based compositions, rubber compositions, cosmetics, cleaning formulations, paper making, drilling fluids and cements, plaster formulations, non-woven fabrics, fibres, foams, orthoplastic casts, (pre-) ceramic materials, and polymer- based nanocomposite material. These resin compositions may further comprise additives conventionally used in such resin compositions. Examples of such additives are cross-linking compounds, UV stabilisers, initiators, flame retardants, catalysts, leveling agents, pigments, dyes, heat-stabilisers, anti-oxidants, fillers (like hydroxyl apatite, silica, carbon black, glass fibres, and other inorganic materials), nucleating agents, impact modifiers, plasticisers, rheology modifiers, and degassing agents, etc.

Furthermore it was found that organic solvent from the organosol could be removed from the resin by means of evaporation after the addition of the organosol to a resin, and that the resulting nanoparticle enriched resins still are transparent and stable over time with a particle loading up to 30%.

In a preferred embodiment the metal oxide organosol with a solid content ranging from 15% to 70% prepared in accordance with the present invention is used in a coating composition in combination with a resin. Such coating compositions include solvent borne coatings, solvent-free coatings, and water borne coatings. The use of the resin/nanoparticle composition prepared via the organosol improves the scratch resistance of the coating composition. The resin/nanoparticle composition further may improve the mar resistance, the flame resistance, and/or the car wash resistance of the coating composition, and it generally reduces the expansion coefficient of the coating composition and/or the shrinkage of the coating composition during cure. Additionally, the amount of metal oxide nanoparticles in the coating compositions can be higher than conventionally used.

The invention will be elucidated with reference to the following examples. These are intended to illustrate the invention but are not to be construed as limiting in any manner the scope thereof.

Examples

Example 1 (preparation of an organosol) In a 1 litre conic flask, 45 g of Arquad MCB-50 was added to 400 g of butyl acetate. This mixture was heated under stirring to a temperature of 50 ⁰C until a clear liquid was obtained. 45Og of Bindzil 30NH3/220 (containing 15 nm silica nanoparticles) was dropwise added to the mixture, while keeping the temperature at 5O⁰C. Stirring was continued for 5 more minutes after the addition of the Bindzil was completed. Then the mixture was put in a separating funnel and the turbid non-aqueous phase (containing butyl acetate and the nanoparticles) was separated from the aqueous phase (containing the excess of Arquad). The non-aqueous phase had a solid content of 28,5 wt.%

Example 2 (preparation of an organosol)

Example 1 was repeated in a 2 litre conic flask using the following ingredients:

100Og butyl acetate - 1000g Bindzil 15/500 (containing 5 nm silica nanoparticles)

13Og Arquad MCB-50. The non-aqueous phase had a solid content of 17 wt.%.

Example 3 (preparation of an organosol) Example 1 was repeated whereby the Bindzil 30NH3/220 was added in one step. In this example a clear aqueous phase was obtained and a non-aqueous phase containing 28.7 wt.% of solid particles.

Example 4 (preparation of resin with nanoparticles dispersed) 350 g of the non-aqueous phase of Example 1 was added to 400 g of Setal291 (ex. Nuplex). The butyl acetate solvent present in the non-aqeous phase was evaporated at 60 - 7O⁰C using a Rotavap. After the evaporation was completed, a clear resin was obtained with a particle loading of around 20% by weight (based on the total weight of the resin).

Example 5 (direct loading of low viscous binder) In a 1 litre conic flask, 70 g of Arquad MCB-50 was added to 250 g of butyl acrylate. While the mixture was stirred, 700 g of Bindzil 30NH3/220 (containing 15 nm silica nanoparticles) was added at once to the mixture. Stirring was continued for 5 more minutes after the addition of the Bindzil was completed. Then the mixture was put in a separating funnel and the non-aqueous phase (containing butyl acrylate and the nanoparticles) was separated from the aqueous phase (containing the excess of Arquad). 500 ml of distilled water was added to the non-aqueous phase was and the mixure was stirred for another 5 minutes. Then the aqueous phase was separated from the non-aqueous phase. The non-aqueous phase had a solid content of 49,8 wt.%.

Example 6 (preparation of a 6 nm SiO? organosol)

25 gr. Arquad 16-50 was added to 100 gr BuAc. To this 200 gr. Bindzil 15/500 from EKA (15% of 6 nm SiO₂ in water) was added at once while stirring. Stirring was continued for 5 minutes. The mixture was put in a separation funnel and 2 phases formed, the lower being the organosol. The organosol was tapped and once more mixed with 200 gr. fresh water (to remove impurities and salt traces). After this washing step, the mixture was put in a funnel and left to separate again. After 1 hour the lower phase was tapped and ready to be added to a resin. Yield = 28.5 % (wt/wt), including the stabilizer.

Optionally the organosol can be partially stripped using a rotavap to remove residual water by azeotropic distillation. Preferably this water removal step is done once the binder is added.

Example 7 (preparation of a 15 nm SiO? organosol)

30 gr. Arquad 2.8-50 was added to 100 gr BuAc. To this 250 gr. Bindzil 30 NH3/220 from EKA (30% of 15 nm SiO₂ in water) was added at once while stirring. Stirring was continued for 5 minutes. The mixture was put in a separation funnel and 2 phases form, the lower being the organosol. After 1 hour the lower phase was tapped and ready to be added to a resin. Yield = 47 % (wt/wt), including the stabilizer.

Example 8 (preparation of a 15 nm SiO? organosol) 30 gr. Arquad MCB-50 was added to 100 gr xylene. To this 250 gr. Bindzil 30 NH3/220 from EKA (30% of 15 nm SiO₂ in water) was added at once while stirring. Stirring was continued for 5 minutes. The mixture was put in a separation funnel and 2 phases form, the lower being the organosol. After 1 hour the lower phase was tapped and ready to be added to a resin. Yield = 47 % (wt/wt), including the stabilizer.

Example 9 (preparation of a CeO? organosol)

30 gr. Arquad 2.8-50 was added to 100 gr BuAc. To this 200 gr. Rhodigard W200 from Rhodia (20% of 5 nm CeO₂ in water) was added dropwise while stirring. Stirring was continued for 5 minutes after ending addition. The mixture was put in a separation funnel and 2 phases form, the lower being the CeO₂ organosol. After 1 hour the lower phase was tapped and ready to be added to a resin. Yield = 35% (wt/wt), including the stabilizer.

Example 10 (preparation of an TiO? organosol)

10 gr. Arquad 2.8-50 was added to 100 gr BuAc. To this 100 gr. S5-300B from Millenium Chemicals (17.5% TiO₂ in water) was added dropwise while stirring. Stirring was continued for 5 minutes after ending addition. The mixture was put in a separation funnel and 2 phases form, the lower being the TiO₂ organosol. After 1 hour the lower phase was tapped and ready to be added to a resin. Yield = 18% (wt/wt), including the stabilizer.

Example 11 (preparation of an ITO organosol) 4 gr. Arquad 2.8-50 was added to 100 gr BuAc. To this 100 gr. VP AdNano® ITO from Degussa (20 % ITO in water) was added at once while stirring. Stirring was continued for 5 minutes. The mixture was put in a separation funnel and 2 phases form, the lower being the ITO organosol. After 1 hour the lower phase was tapped and ready to be added to a resin. Yield = 18% (wt/wt), including the stabilizer.

Example 12 (preparation of a functionalized SiO? organosol)

16 gr. Arquad 2.8-50 and 8 gr. 3-(methacryloylamino)propyl- trimethylammonium chloride was added to 100 gr BuAc. To this 250 gr. Bindzil

30 NH3/220 from EKA (30% of 15 nm SiO₂ in water) was added at once while stirring. Stirring was continued for 5 minutes. The mixture was put in a separation funnel and 2 phases form, the lower being the organosol. After 1 hour the lower phase was tapped and ready to be added to an acryloyl functional resin. Yield = 47 % (wt/wt), including the stabilizer.

Example 13 (direct preparation of a SiO? loaded resin)

30 gr. Arquad 2.8-50 was added to a mixture of 80 gr Shellsoll D60 and 100 gr. alkyd (Setal 291 from Akzo Nobel). To this 250 gr. Bindzil 30 NH3/220 from EKA (30% of 15 nm SiO₂ in water) was added at once while stirring. Stirring was continued for 5 minutes. The mixture was put in a separation funnel and 2 phases form, the lower being the nanoparticles loaded resin with solvent. After 5 hours at 60⁰C the lower phase was tapped. The obtained resin can be used to formulate alkyd based lacquers. Yield = 33 % (wt/wt), including the stabilizer.

The formulation was partially stripped using a rotavap to remove residual water. Example 14 (preparation of SiO? loaded acrylate monomer for emulsion polymerization)

30 gr. Arquad 2.8-50 was added to 100 gr. butylacrylate. To this 250 gr. Bindzil 30 NH3/220 from EKA (30% of 15 nm SiO₂ in water) was added at once while stirring. Stirring was continued for 5 minutes. The mixture was put in a separation funnel and 2 phases form, the lower being the nanoparticles loaded monomer. After 1 hour the lower phase was tapped. The obtained formulation can be used as a starting material for preparing SiO₂ loaded acrylics dispersions using (mini) emulsion polymerization. Yield = 47 % (wt/wt), including the stabilizer.

Example 15 (direct preparation of a SiO? loaded reactive alkyd diluent) 20 gr. Arquad 2.8-50 was added to 100 gr. alkyd (Setal 276 from Akzo Nobel). To this 200 gr. Bindzil 30 NH3/220 from EKA (30% of 15 nm SiO₂ in water) was added at once while stirring. Stirring was continued for 5 minutes. The mixture was put in a separation funnel and 2 phases form, the lower being the nanoparticles loaded reactive diluent. After 5 hours at 60⁰C the lower phase was tapped. The obtained resin can be used to formulate alkyd based lacquers. Yield = 41 % (wt/wt), including the stabilizer.

Example 16 (preparation of a alkvd resin with nanoparticles) 100 grams of the organosol obtained in example 7 was mixed with 100 gr. alkyd (Setal 290 from Akzo Nobel). To this mixture 50 gr. Shellsol D60 was added. The formulation was stripped by a rotavap to remove the butylacetate and residual water. After stripping Shellsol D60 was added up to a VOC of 300 gr/l. The formulation can be used in translucent lacquer applications.

Example 17 (preparation of a polyol resin with nanoparticles)

100 grams of the organosol obtained in example 7 was mixed with 100 gr. polyol (Setal 164 from Akzo Nobel). The formulation was stripped by a rotavap to remove residual water which could interfere with NCO-OH crosslinking. After stripping 50 gr. BuAc and residual water, a fresh portion of 100 gr. BuAc was added once more and the formulation was stripped once more until no water could be removed anymore by azeotropic distillation. Fresh BuAc was added up to 300 gr/l. The formulation can be used in translucent NCO-OH applications.

Example 18 (preparation of an organosol stabilized by phosphonium)

10 gr. bis(thmethylhexyl)dimethyl-phosphonium tosylate is dissolved in 100 gr BuAc. To this 100 gr. Bindzil 30 NH3/220 from EKA (30% of 15 nm SiO₂ in water) is added dropwise while stirring. After addition is completed stirring is continued for 5 minutes. The mixture is put in a separation funnel and 2 phases form, the lower being the organosol. After 1 hour the lower phase is tapped and ready to be added to a resin. Yield = 28% (wt/wt), including the stabilizer. Phosphonium is used to minimize yellowing.

Example 19 (preparation of an organosol stabilized by phosphonium) 4 gr. bis(trimethylpentyl)dimethyl-phosphonium tosylate and 12 gr. triethyl(octadecyl)-phosphonium bromide from Cytec was dissolved in 100 gr BuAc. To this 200 gr. Bindzil 30 NH3/220 from EKA (30% of 15 nm SiO₂ in water) was added dropwise while stirring. After addition was completed stirring was continued for 5 minutes. The mixture was put in a separation funnel and 2 phases form, the lower being the organosol. After 4 hours the lower phase was tapped and ready to be added to a resin. Yield = 42% (wt/wt), including the stabilizer.

Example 20 (preparation of an organosol stabilized by phosphonium and ammonium) 6 gr. Arquad 2.8-50 and 12 gr. triethyl(octadecyl)-phosphonium bromide from Cytec was dissolved in 100 gr BuAc. To this 200 gr. Bindzil 30 NH3/220 from EKA (30% of 15 nm SiO₂ in water) was added at once while stirring. Stirring was continued for 5 minutes. The mixture was put in a separation funnel and 2 phases form, the lower being the organosol. After 4 hours the lower phase was tapped and ready to be added to a resin. Yield = 42% (wt/wt), including the stabilizer.

Note: all Arquad® products are quaternary ammonium products produced by Akzo Nobel

Claims

1. Process for the preparation of a metal oxide organosol in a nonaqueous phase comprising the steps of: a) Preparing a solution of a quaternary compound in a composition liquid at room temperature, said liquid composition comprising a compound selected from the group consisting of an organic solvent containing ester groups, a reactive diluent, and a low viscous binder resin; b) Adding an aqueous composition comprising a metal oxide sol to said solution wherein a mixture is formed having an aqueous phase and a non-aqueous phase; c) Separating the aqueous phase from the non-aqueous phase; d) Collecting the non-aqueous phase comprising the metal oxide organosol.

2. Process according to claim 1 , characterised in that the metal oxide is SiO₂, CeO₂, TiO₂ or ITO.

3. Process according to claim 1 or 2, characterised in that the quaternary compound is selected from the group consisting of quaternary ammonium compounds and quaternary phosphonium compounds.

4. Process according to claim 3, characterized in that the quaternary compound can be represented by the following chemical formula (I):

R¹R²R³R⁴X⁺ - Y^" (I)

wherein: o R¹ represents hydrogen or a C1 - C30 alkyl or aryl group or modifications thereof; o R² represents hydrogen or a C1 - C30 alkyl or aryl group or modifications thereof; o R³ represents hydrogen or a C1 - C30 alkyl or aryl group or modifications thereof; o R⁴ represents hydrogen or a C1 - C30 alkyl or aryl group or modifications thereof; o X represents Nitrogen (N) or Phosphor (P); o Y represents a monovalent negatively charged countergroup; and o at least one of groups R¹ - R⁴ represents a C6 - C22 alkyl group.

5. Process according to any of the preceding claims, characterised in that the quaternary compound is a quaternary fatty acid.

6. Process according to any of the preceding claims, characterized in that the liquid compound is an organic solvent containing ester groups selected from the group consisting of acetates and alkylacetates.

7. Coating composition comprising a resin and an organosol obtained by a process according to any one of claims 1 - 6.

8. Process for the preparation of a transparent resin composition comprising the steps of: a) Preparing a solution of a quaternary compound in an organic solvent containing ester groups; b) Adding an aqueous composition comprising a metal oxide sol to said solution wherein a mixture is formed having an aqueous phase and a non-aqueous phase; c) Separating the aqueous phase from the non-aqueous phase; d) Collecting the non-aqueous phase comprising the metal oxide organosol ; e) Mixing the obtained organosol/organic solvent mixture into a resin; f) Optionally stripping off the solvent from the thus obtained mixture also comprising the resin and the metal oxide organosol.

9. Process for the preparation of a transparent resin composition comprising the steps of: a) Preparing a solution of a quaternary compound in a reactive diluent; b) Adding an aqueous composition comprising a metal oxide sol to said solution wherein a mixture is formed having an aqueous phase and a non-aqueous phase; c) Separating the aqueous phase from the non-aqueous phase; d) Collecting the non-aqueous phase comprising the metal oxide organosol ; e) Reacting the reactive diluent in the non-aqueous phase to obtain a resin.

10. Process for the preparation of a transparent resin composition comprising the steps of: a) Preparing a solution of a quaternary compound in a low viscous binder resin liquid at room temperature; b) Adding an aqueous composition comprising a metal oxide sol to said solution wherein a mixture is formed having an aqueous phase and a non-aqueous phase; c) Separating the aqueous phase from the non-aqueous phase; d) Collecting the non-aqueous phase comprising the metal oxide organosol.

11. Transparent resin composition comprising 5 - 60 wt.% of metal oxide nanoparticles.

12. Coating composition comprising the resin composition of claim 11.