Title: Composite additive with a high concentration of solid particulate material and process for producing it

DESCRIPTION

Field of application

In its more general aspect, the present invention provides for composite of a solid particulate material, said composite being in form of granules or in form of a free-flowing powder.

In particular, the invention relates to a composite of a solid particulate material comprising at least one solid particulate material and a binder (wetting-dispersing agent) .

The present invention relates to the use of that composite as a universal additive for obtaining aqueous (water-borne) or solvent (solvent-borne) pigment (or filler) pastes adapted to colour paints, inks, varnishes or enamels.

Prior art

Pigments, fillers and other solid particulate materials are commonly used to impart colour, opacity, texture or rheological effects to the material they are dispersed; among other properties which they could impart improved resistance to fire and/or light can be listed.

They could be used as substances suitable for improving the mechanical and/or thermal properties of the material itself, too.

In particular, pigments are coloured substances or materials, white or black, which by dispersion in solvent, are capable of imparting thereto their own colour or hue in a permanent way, imposing a specific colour to the reflected or transmitted light as a result of a selective absorption of particular wavelengths. A pigment has normally a high tinting strength with respect to the solvent or material to which it is mixed to colour it.

Pigments are mainly particulate solids having an irregular surface, which varies among a kind of pigment and the other and interacts with different materials in a different manner.

The smallest units of pigments and, in general, of similar solid additives are called primary particles. The structure and shape of these primary particles depends on the crystallinity of the pigment. During the pigment production process, primary particles generally aggregate and generate agglomerates.

Agglomerates are clusters of primary particles which can be broken down via an efficient milling and dispersion process.

In any case, during the milling and dispersion process of the pigment into a binder, high shear is generally requested to break up these agglomerates.

The primary particles of a pigment may be nodular, spherical, prismatic, acicular or lamellar. The smaller are these particles, the greater is their surface energy and, therefore, the more likely it is that they will clump together during manufacturing.

In order to let pigment, fillers and other solid particulate materials interacting with solvents and final dispersing media in the best way possible, these solid particulate materials are generally combined with at least one additive.

This additive or combination of additives is different according to both the kind of pigment, filler or solid particulate material, and required final application, i.e. the solvent or final dispersing medium.

In general, there are two commonly used techniques of incorporating insoluble dry pigments in liquid paints, namely, direct pigment grinding and “grinding free” pigment compositions.

Direct pigment grinding involves milling and dispersing dry pigments directly in a liquid coating together with a resin solution, comprising a solvent (or water) and a wetting-dispersing agent, whose molecules will then function as stabilizing agents after forming a protective layer over the de-agglomerated primary pigment particles.

The role of the conveniently added wetting-dispersing agent is to minimize flocculation phenomena by lowering the surface tension of the primary pigment particles when they are disaggregated, thereby replacing the air around the surface of these particles.

Normally, mono-pigment pastes obtained by carrying out several passages in a mill, for example a ball-mill, while pigments are not only disaggregated but also linked to suitable resins.

In other words, direct pigment grinding has disadvantages. Indeed, direct pigment grinding can be time consuming and uneconomical specially when making small batches of multiple colors of the same coating. Color adjustment during production could also be difficult.

Additionally, grinding steps can easily be dangerous because of the inevitable production of potential hazardous submicrometric powders in the mill.

Indeed, operators which are responsible for manufacturing intermediate products can enter directly in contact with these grounded additives, such as pigments, silica or titanium dioxide, i.e. substances which are potentially dangerous for health due to their small particle dimensions. Solid pigment compositions, also called “grinding free”, i.e. are commonly produced by extrusion process.

However, this technology has the major drawbacks of:

- determining sticking problems when solid pigment compositions are stored or transported at temperature above 40°C;

- the concentration of the pigment (or filler) is low (20-40% by weight);

- polymeric resins (which are mandatory) are present in high concentration and limit the use of at the same pigment (or filler) composition in both solvent-borne or waterborne applications at the same time.

Indeed, solid pigment compositions commonly exists in form of granules or of powder made of primary pigment particles coated with amorphous resins having low glass transition temperature, such as aldehydic, ketonic or acrylic resins.

Accordingly, the need to provide a new type of universal compositions (both solvent- and water-borne) comprising pigments, fillers or other solid particulate materials, with a high additive content is particularly felt; specifically, this new type of additive composition should ensure the following performances: a) good stability of the composition and of the final dispersing medium, i.e. a solvent or an aqueous-base dispersing medium; b) good dispersion in the final dispersing medium, i.e. a solvent or an aqueous-base dispersing medium; c) strong colouring hues (when the additive is a pigment); d) low conversion costs and e) minimum complexity of the production process, in particular safe working environment during the final application and, at the end, f) sticking problems are avoided.

An additional drawback is that prior art pigment compositions have limited compatibility with regard to the dispersing medium needed for the final applications, since this compatibility depends not only by the choice of the solvent used during the dispersion process of the pigment, but also by the physical-chemical nature of the binder (wetting- dispersing agent) itself.

In other word, nowadays, a vast range of different liquid and solid pigment compositions are produced, each of them being suitable for a specific final application, for example for being dispersed in an organic solvent or, alternatively, in an aqueous-based dispersing medium.

Accordingly, this complexity is a severe limitation for the management of the overall production and logistic system.

For these reasons, providing a new type of additive formulation, comprising pigments, fillers or other solid particulate materials, which can be universally used, for example in both solvent- and aqueous- based dispersing media, is sought.

The technical problem underlying the present invention is thus to provide an additive formulation, comprising pigments, fillers or other solid particulate materials, which is stable and has not problems from the point of view of its dispersibility in the desired final dispersing medium, in other words which is universal, i.e. dispersible in both solvent- and aqueous-based dispersing medium, and with low complexity from the point of view of the production method thereof and of its dispersion in the final dispersing medium, so as to overcome the drawbacks previously mentioned with reference to the prior art.

Summary of the invention

That technical problem is solved by a composite of solid particulate material, suitable for being used as universal additive for coloring of paints, inks, varnishes or enamels, in form of granules or in form of a free-flowing powder having a volume-based particle size equal to or larger than 10 pm, and comprising at least one solid particulate material and at least one binder, said solid particulate material having a concentration comprised between 20% and 97% by weight with respect to the total weight of said composite and being constituted by agglomerated primary particles, wherein the primary particles that constitute said solid particulate material are coated by said at least one binder.

Specifically, the aforementioned at least one binder is selected from alkylammonium salt of a polyethylene imine copolymer, phosphoric acid ester copolymer, unsaturated polyamide and acid ester salts copolymer or styrene-maleic anhydride copolymer with nitrogen-containing groups.

Preferably, said at least one binder may be selected from phosphoric acid ester copolymer, unsaturated polyamide and acid ester salts copolymer or styrene-maleic anhydride copolymer with nitrogen- containing groups.

Advantageously, these more specific classes of binders allow the composite of solid particulate material according to the present invention to be even more easily dispersed in final dispersing medium both solvent- or aqueous-based and, at the same time, they guarantee the final production of an intermediate dispersion having optimal stability, since indeed these specific classes of binders have optimal affinity with both solvent and an aqueous-base dispersing media.

More preferably, said at least one binder is a phosphoric acid ester copolymer.

In particular, said phosphoric acid ester copolymer is an alkylol ammonium salt of phosphoric acid ester copolymer.

More preferably, said at least one binder is a styrene-maleic anhydride copolymer with nitrogen-containing groups; even more preferably, said at least one binder is a styrene-maleic anhydride imide copolymer or a styrene-maleic anhydride copolymer with quaternized ammonium groups.

Most preferably, when said at least one binder is a styrene-maleic anhydride imide copolymer, said at least one binder is an amine- functionalized styrene-maleic anhydride imide copolymer.

Alternatively, according to an embodiment not according to the present invention, the aforementioned at least one binder is selected from alcohol or polyalcohol ethoxylates, fatty acid ethoxylates or modified polyacrylate with amine groups.

Preferably, said at least one binder is an alcohol or polyalcohol ethoxylates.

More preferably, said alcohol or polyalcohol ethoxylates is ethoxylated sorbitan ester.

In particular, according to the present invention said fatty acid ethoxylates may be a C8-C30 fatty acid.

According to the present disclosure, the expression “suitable for being used as universal additive” means that the composite of solid particulate material according to the present invention can be used as universal additive, namely is an additive which can be used to obtain both solvent- and water-borne dispersions, i.e. pastes, in particular pigment or filler pastes adapted to color paints, inks, varnishes or enamels.

Indeed, advantageously, the composite of solid particulate material according to the present invention is stable and has not problems from the point of view of its dispersibility in both solvent and water dispersing media.

According to the present disclosure with the term “binder” it is intended a wetting-dispersing agent, namely a chemical agent which is capable of both wetting and acting as a dispersant for the primary particles that constitute the aforementioned solid particulate material.

Accordingly, as it will be explained with reference to the process according to the present invention, the solid particulate material is provided in form of agglomerates.

These agglomerates are firstly disaggregated and optionally grinded in presence of the binder, which firstly acts as wetting agent by substituting and removing air which previously surrounded the primary solid particles in the agglomerates, thereby reducing the surface tension of these primary solid particles.

Then, primary solid particles are stabilized after they have been separated from each other and the functionality of the binder, which now acts as dispersing agent, prevents the spontaneous and uncontrolled process of gluing together of the primary solid particles.

Preferably, the composite according to the present invention may comprise said at least one binder in a quantity comprised between 3% and 60%, preferably between 4% and 55%, by weight on its total weight.

In particular, the aforementioned binder has preferably a weight- average molecular weight comprised between 3000 to 35000 g/mol as obtained in conformity with 4001-13 ASTM standard test method.

More in particular, according to a preferred embodiment, the aforementioned binder has preferably a weight-average molecular weight comprised between 6000 and 20000 g/mol as obtained in conformity with D 4001-13 ASTM standard test method.

Ever more preferably, also with reference to its process of production, the present invention provides for a composite of solid particulate material, wherein said primary particles are coated by said at least one binder and have a particle size between 0.5 pm and 5 pm.

In particular, the particle size of those primary particles, coated by said at least one binder, is intended as the mean diameter (i.e. a diameter D50) of those primary particles as measured with a Beckman Coulter particle size analyser having an optical model Fraunhofer, Rf780z.

Preferably, said at least one solid particulate material can be selected from a pigment or a filler or mixtures thereof.

According to another preferred embodiment of the present invention, the at least one solid particulate material is a pigment.

Preferably, said pigment can be selected from inorganic pigment, organic pigment, carbon black or any combination thereof.

According to extent of the present invention and with reference to the detailed description, the pigment can be an inorganic metal-based pigment, such as chrome pigments, iron oxide pigments or copper pigments, these pigments being coloured inorganic pigments, or such as titanium pigments, the latter pigments being coloured or white inorganic pigments.

The pigment can also be an organic pigment, such as an organic pigment which is natural or has a natural origin (i.e. semi-synthetic) or a synthetic organic pigment.

Preferably, according to a preferred embodiment of the present invention, said at least one solid particulate material is an inorganic pigment.

According to another preferred embodiment of the present invention, the at least one solid particulate material is a filler.

Preferably, said filler can selected from calcium carbonate, kaolin, mica, talc, silica, more preferably pyrogenic silica, barium sulphate or any combination thereof. More preferably, said filler is calcium carbonate.

In a preferred manner, in the above-mentioned composite according to the present invention said at least one solid particulate material can be present in an amount comprised between 30% and 90% by weight with respect to the total weight of the composition.

More preferably, said at least one solid particulate material is present in an amount comprised between 55% and 90%, even more preferably between 60% and 90%, by weight on the total weight of the composite.

In particular, when said at least one solid particulate material is an inorganic pigment, the latter can be present in an amount comprised between 40% and 97%, by weight on the total weight of the composite.

Alternatively, when said at least one solid particulate material is an organic pigment or carbon black, these pigments can be present in an amount comprised between 30% and 90%, by weight on the total weight of the composite.

Advantageously, the composite of solid particulate material according to the present invention is in form of dust-free granules or dust-free free- flowing powder.

In accordance with the present disclosure, the expression “dust-free” means an agglomerate of material in a granular form and essentially devoid of residues having a particle size which is lower than that of those granules, in particular devoid originally (i.e. immediately after concluding the production method thereof) of particles with a size which is lower than 10 pm.

Some commonly used fillers and pigments, such as titanium dioxide, are now classified as category 2 suspected carcinogen by inhalation according to European Union Regulation (EC) 1272/2008.

This decision is motivated by the presence of submicrometric particles in commercially available fillers and pigments which are normally manipulated under potentially hazardous conditions with reference to the prior art.

Indeed, being devoid of particles with a size which is lower than 10 pm, the composite of solid particulate material according to the present invention cannot be classified as suspected carcinogen by inhalation according to EU regulations.

Preferably, the particle size of the composite of solid particulate material, which is in form of granules or of free-flowing powder, according to the present invention is in general comprised between 10 mih and 3000 mih.

According to a preferred embodiment, said composite of solid particulate material according to the present invention is in form of granules.

Preferably, said composite of solid particulate material, which is in form of granules, has a volume-based particle size comprised between 150 pm and 3000 pm, more preferably between 300 pm and 2000 pm.

According to an alternative embodiment of the present invention, the composite of solid particulate material according to the present invention is in form of a free-flowing powder.

Preferably, said composite of solid particulate material, which is in form of a free-flowing powder, has a volume-based particle size comprised between 40 pm and 150 pm.

In accordance with the present disclosure the term “volume-based particle size” means a value indicating the mean volume diameter of the particles (in form of agglomerates or clusters) constituting the composite according to the present invention.

The volume-based particle size equals the diameter of the ideal sphere that fully comprises a given particle. In particular, when sieve analysis is used, the diameter of the ideal sphere corresponds to the mesh size of the sieve.

The particles of the composite according to the present invention have a volume-based particle size as measured with a Digital Electromagnetic Sieve Shaker of Filtra Vibration mod. FTL 0200.

Advantageously, as it will be discussed further with reference to the process according to the invention and to the experimental part, the present composite of solid particulate material can be easily and finely dispersed in an organic or aqueous medium, according to the final required application.

In other words, the present invention successfully provides for a new type of composite additive, comprising pigments, fillers or other solid particulate materials, which can be universally used.

Accordingly, the present composite of solid particulate material can be universally and finely dispersed in both organic and aqueous media, not only due to chemical and physical characteristics of said at least one binder, but also due to the characteristic particulate structure of the granules or of the powder particles which constitute the present product, in which the binder (wetting-dispersing agent) has the function of i) reducing the surface tension existing there between the original primary particles of the solid particulate material, while they are disaggregated during its production process which will be described later, and ii) preventing (together with the stabilizing action of the optional binder) the mentioned primary pigmentary particles from reaggregating.

Moreover, the present composite of solid particulate material is completely devoid of nanometric dusts and, more in general, dusts having a size lower than 10 pm, more importantly hazardous nanometric dusts, and additionally the present composite can be used to produce grinding free universal formulation with low complexity from the point of view of the final application, namely during the dispersion of the solid particulate material into the final dispersing medium, thus solving the aforementioned safety issues during the manipulation of pigments and similar solid material.

Moreover, the present composite of solid particulate material is solvent free, not subject to storage limitation, and easy to incorporate into the final dispersing medium by stirring or kneading forming a stable dispersion of high solid concentration of fine particles.

The present composite of solid particulate material can therefore successfully replace conventional pastes or solid concentrates, normally used in coatings.

Indeed, the present invention further provides for the use of the above- mentioned composite for coloring of paints, inks, varnishes or enamels.

Accordingly, the aforementioned problem is solved at the same time by a dispersion comprising a dispersing medium and the composite of solid particulate material according to the present invention, wherein said dispersing medium is an organic solvent or an aqueous solvent.

Preferably, said dispersion is a paste which is adapted to color a paint, an ink, a varnish or an enamel.

Then, the present invention further provides for a method for producing said paste, wherein this method comprises a step of dispersing said composite of solid particulate material into said a dispersing medium.

In particular, the dispersion of the aforementioned composite is an intermediate product for the colouring of liquid paints, varnishes or enamels, of powder paints or for the production of a liquid concentrated pastes.

With respect to concentrated pastes according to the prior art, the composite of solid particulate material according to the present invention allows to achieve the following advantages: a) no dispersion liquid to be transported (normally >50% by weight of the concentrated paste); b) no sedimentation problems; c) higher pigment or filler concentration (> 100% of increase).

Moreover, by using the composite of solid material according to the present invention, the subsequent varnish production process (production chain) contemplates an additional single step (one step layout), which is the dispersion-let down, if compared to traditional similar preparation, the latter requiring three different steps (dispersion, grinding and let down) .

A shorter production chain allows to achieve the following advantages: a) a high digitalization in the management of the varnish manufacturing process; b) a more environment-friendly production process since only a single tank needs to be cleaned from the pigment residues of the so-obtained varnish, if compared to three tanks that need to be used and cleaned in a traditional production processes; c) severe complexity reduction of the overall manufacturing process.

In particular, but not exclusively the composite of the present invention is intended for use in the following applications:

- as a paint for industrial applications (solvent- and water-borne);

- in decorative paints (solvent- and water-borne)

- in car paint

- in all type of inks (solvent- and water-borne) .

The above technical problem is also solved by a method for producing the above-mentioned composite of solid particulate material, suitable for being used as universal additive for coloring of paints, inks, varnishes or enamels and in form of granules or in form of a free- flowing powder. That method comprises the steps of:

- disaggregating and optionally grinding at least one solid particulate material which is constituted by agglomerated primary particles into the primary particles that constitute it by subjecting it to the action of shear forces in the presence of at least one binder, the so-obtained mixture of the at least one solid particulate material and the binder optionally having a first predetermined value of temperature which is comprised between 30°C and 150°C, preferably between 60°C and 130°C, thereby obtaining primary particles coated by said at least one binder;

- aggregating said primary particles coated by said at least one binder into aggregates by means of the action of shear forces,

- cooling and/or leaving to cool said aggregates, thereby obtaining a composite of solid particulate material, this composite having a volume- based particle size equal to or larger than 10 pm and comprising said at least one solid particulate material and said at least one binder, the solid particulate material having a concentration comprised between 20% and 97% by weight with respect to the total weight of said composite; wherein said at least one binder is selected from alkylammonium salt of a polyethylene imine copolymer, phosphoric acid ester copolymer, unsaturated polyamide and acid ester salts copolymer or styrene-maleic anhydride copolymer with nitrogen-containing groups.

Preferably, said at least one binder is selected from phosphoric acid ester copolymer, unsaturated polyamide and acid ester salts copolymer or styrene-maleic anhydride copolymer with nitrogen-containing groups.

More preferably, said at least one binder is a phosphoric acid ester copolymer.

In particular, said phosphoric acid ester copolymer is an alkylol ammonium salt of phosphoric acid ester copolymer.

More preferably, said at least one binder is a styrene-maleic anhydride copolymer with nitrogen-containing groups; even more preferably, said at least one binder is a styrene-maleic anhydride imide copolymer or a styrene-maleic anhydride copolymer with quaternized ammonium groups. Most preferably, when said at least one binder is a styrene-maleic anhydride imide copolymer, said at least one binder is an amine- functionalized styrene-maleic anhydride imide copolymer.

Alternatively, according to an embodiment not according to the present invention, the aforementioned at least one binder is selected from alcohol or polyalcohol ethoxylates, fatty acid ethoxylates or modified polyacrylate with amine groups.

Preferably, said at least one binder is an alcohol or polyalcohol ethoxylates.

More preferably, said alcohol or polyalcohol ethoxylates is ethoxylated sorbitan ester.

Preferably, the volume-based particle size of the composite of solid particulate material, which can be obtained by the process according to the present invention and is in form of granules or of free-flowing powder, may be comprised between 10 pm and 3000 pm.

In particular, the process of to the present invention is carried out without using any solvent.

Accordingly, said at least one solid particulate material used during said disaggregating step is devoid of any solvent.

In particular, with the term “solvent” it is intended a substance or a mixture of a plurality of substances, which is able to dissolve or disperse other substances and which is liquid at room temperature, namely between 20-40°C, for example a nonpolar solvent, a polar aprotic solvent, a polar protic solvent or any mixture thereof.

The process parameter and the physical-chemical properties of the binder (wetting-dispersing agent) and the configuration of the equipment are key parameters to obtain its proper adsorption onto said solid particulate material primary particles. Specifically, said solid particulate material is firstly finely divided into the primary particles which constitute it by the aforementioned shear forces, in particular high shear forces, and mixed with the binder to obtain said primary particles wetted by the latter. This occurs during disaggregating step.

Accordingly, in an advantageous manner, the process of to the present invention takes advantage of the dispersing ability of the binder (wetting-dispersing agent), which is able to coat the primary particles of that solid particulate material by forming a covering layer.

Moreover, during said disaggregating step the wetting of the primary particles coated by the binder (wetting-dispersing agent) produces the complete removal of interparticle entrapped air and moisture.

In particular, during disaggregating step the primary particles of said solid particulate material, for example a pigment, are separated from each other without any sudden and uncontrolled re-agglomeration.

Then, during following agglomeration step, due to the action of said shear forces in combination with said at least one binder the primary particles of said solid particulate material form stable agglomerates and then further grow till a targeted size, thereby obtaining the composite of solid particulate material according to the present invention.

The present process is carried out with the aforementioned categories of binders (wetting-dispersing agents) and, additionally, that the composite of solid particulate material of the present invention is indeed completely devoid of any solvent allows to universally use the composite according to the present invention, optionally comprising pigments, fillers or other solid particulate materials, indeed in both solvent- and aqueous-based applications.

Indeed, the compatibility of the present composite of solid particulate material is not limited by the choice of the solvent which could have been used during its production process, its production process being completely solvent-free.

The composite of solid particulate material composite thus obtained can be effectively dissolved in the desired dispersing medium, for example an organic solvent, an aqueous solvent, depending on the physical and chemical properties of the aforementioned binder (wetting-dispersing agent) used during the present production process.

Preferably, said step of disaggregating and said step of aggregating may be carried out at a temperature comprised between 20°C and 150°C.

Preferably, said disaggregating step is carried out by means of a high shear mixer granulator comprising a hollow body having at least one inlet opening and at least one discharge opening, optionally a heating and/or cooling jacket to bring and/or keep the temperature of said hollow body to a predetermined value of temperature, and a rotating screw shaft arranged in said hollow body, whereon at least one impeller is mounted.

More preferably, during said disaggregating step the rotating screw shaft is driven in rotation so that the average peripheral speed of said at least one impeller is comprised between 5 m/s and 50 m/s, even more preferably between 5 m/s and 25 m/s.

Specifically, due to the action exerted by said at least one impeller in contact with said at least one solid particulate material in the presence of said least one binder shear forces, in particular high shear forces, are applied onto said at least one solid particulate material hereby causing its disaggregation into its primary particles which are, at the same time, coated by said at least one binder.

Preferably, said rotating screw shaft comprises 1 to 7 impellers, more preferably four impellers, mounted in series on said rotating shaft.

According to the composite which is to be obtained, i.e. as a function of the type of solid particulate material and of the binder, as well as of the desired final volume-based particle size, the number and the arrangement of those impellers on the rotating screw shaft can be suitably modified.

In the same preferred way, according to the final composite which is to be obtained, the conformation and the size of those impellers can be suitably modified. For example, those impellers can have a specific number of blades, the latter having a specific shape and a specific inclination with respect to the direction of the flow of material moving inside the hollow body of the high shear mixer granulator.

In particular, in accordance with a preferred embodiment, the inclination of the blades of those impellers can be orientable and adjustable.

Preferably, said disaggregating step is carried out at a first predetermined value of temperature which is comprised between 30°C and 150°C, preferably between 60-130°C.

In particular, essentially due to the friction forces occurring between said at least one impeller, the internal walls of the hollow body of said high shear mixer granulator and said at least one solid particulate material, in said disaggregating step the aforementioned first predetermined value of temperature can be reached.

Advantageously, indeed, said disaggregating step can be carried out without the need to actively heat, i.e. without providing additional heat by heating said heating and/or cooling jacket, said at least one solid particulate material and said at least one binder in the hollow body of said high shear mixer granulator during said disaggregating step.

More preferably, said high shear mixer granulator comprising a heating and/or cooling jacket, in said disaggregating step said heating and/or cooling jacket may be heated to bring the temperature of said hollow body to a first predetermined value of temperature which is comprised between 30°C and 150°C, preferably between 60-130°C. More preferably, said aggregation step is carried out at a second predetermined value of temperature, said second predetermined value of temperature being lower than said first predetermined value of temperature.

According to another preferred embodiment of the present process, in said step of aggregation a further amount of said at least one binder (wetting-dispersing agent) is introduced into said hollow body of the high shear mixer granulator.

Preferably, the further amount of said at least one binder is continuously introduced into said hollow body of the high shear mixer granulator during said step of aggregation.

According to a preferred embodiment, both said disaggregating step and said aggregating step may be carried out by means of a high shear mixer granulator, the process according to the present invention comprises the following steps: a) introducing into said hollow body of the high shear mixer granulator said least one solid particulate material and said at least one binder; b) disaggregating at least one solid particulate material into the primary particles that constitute it by subjecting it to the action of said at least one impeller in the presence of said least one binder, the so-obtained mixture of the at least one solid particulate material and the binder having a said first predetermined value of temperature which is comprised between 30°C and 150°C, preferably between 60°C and 130°C, and obtaining primary particles coated by said at least one binder; c) aggregating said primary particles coated by said at least one binder into aggregates by means of the action of said at least one impeller; d) cooling and / or leaving to cool said aggregates, thereby obtaining said composite of solid particulate material; and e) discharging from said high shear mixer granulator the so-obtained composite of solid particulate material.

Preferably, in said step b) of disaggregating said rotating screw shaft is driven in rotation so that the average peripheral speed of said at least one impeller is comprised between 5 m/s and 50 m/s, more in particular between 5 m/s and 25 m/s.

Preferably, said high shear mixer granulator comprises a heating and/or cooling jacket and in said step c) of aggregation said heating and/or cooling jacket is cooled to bring said hollow body to said second predetermined value of temperature, said second predetermined value of temperature being lower than said first predetermined value of temperature.

More preferably, second predetermined value of temperature may be comprised between 20°C and 140°C.

Preferably, in said step c) of aggregation the rotational speed of said rotating screw shaft is decreased with respect to previous step c) of disaggregating.

Preferably, in said step c) of aggregation said rotating screw shaft is driven in rotation so that the average peripheral speed of said at least one impeller is comprised between 4-20 m/s.

Preferably, said step b) of disaggregating and/or said step c) of aggregating are carried out for a total time between 5 minutes and 60 minutes.

More preferably, said disaggregating step b) is carried out for a time between 5 and 30 minutes.

Even more preferably, said aggregating step c) is carried out for a time between 2 and 15 minutes.

Preferably, in said cooling step d) said aggregates are cooled and / or are left to cool to room temperature, i.e. to a temperature comprised between 20°C and 40°C.

According to an alternative embodiment of the method according to the present invention, the method according to the present invention may be carried out in a discontinuous manner.

According to this alternative embodiment, the process comprises the following steps: a’) introducing into the hollow body of said high shear mixer granulator said least one solid particulate material and said at least one binder; b’) disaggregating at least one solid particulate material into the primary particles that constitute it by subjecting it to the action of said at least one impeller in the presence of said least one binder, the so-obtained mixture of the at least one solid particulate material and the binder having said first predetermined value of temperature which is comprised between 30°C and 150°C, preferably between 60°C and 130°C, and obtaining primary particles coated by said at least one binder; cj aggregating said primary particles coated by said at least one binder into aggregates by means of the action of said at least one impeller; d j discharging from said high shear mixer granulator said aggregates and feeding them into a cooler, said cooler comprising a hollow body having at least one inlet opening and at least one discharge opening, a cooling jacket to cool said hollow body to a second predetermined value of temperature, and a rotating screw shaft arranged in said hollow body, whereon at least one impeller is mounted; ej cooling said aggregates under the action of said at least one impeller, thereby obtaining said composite of solid particulate material; fj discharging from said cooler the so-obtained composite of solid particulate material.

In particular, in said step b’) of disaggregating said rotating screw shaft is driven in rotation so that the average peripheral speed of said at least one impeller is comprised between 5 m/s and 50 m/s, more in particular between 5 m/s and 25 m/s.

Preferably, said high shear mixer granulator comprises a heating and/or cooling jacket and in said step cj of aggregation said heating and/or cooling jacket is cooled to bring said hollow body to said second predetermined value of temperature, said second predetermined value of temperature being lower than said first predetermined value of temperature.

More preferably, second predetermined value of temperature may be comprised between 20°C and 140°C.

Preferably, in said step cj of aggregating said rotating screw shaft of the high shear mixer granulator is driven in rotation so that the average peripheral speed of the at least one impeller is comprised between 4-20 m/s.

Preferably, in said step cj of aggregating the rotational speed of said rotating screw shaft is decreased with respect to previous step c) of disaggregating.

Preferably, said step bj of disaggregating and/or said step cj of aggregating are carried out for a total time between 5 minutes and 60 minutes.

More preferably, said disaggregating step bj is carried out for a time between 5 and 30 minutes.

Even more preferably, said aggregating step cj is carried out for a time between 2 and 15 minutes.

Preferably, during said cooling step ej said mixture of the at least one solid particulate material and the binder is cooled to room temperature, i.e. to a temperature comprised between 20°C and 40°C.

More preferably, during said cooling step e’) the rotating screw shaft of the cooler is driven in rotation so that the average peripheral speed of said at least one impeller is comprised between 4 m/s and 20 m/s and/or wherein said cooling step e’) is carried out for a time between 2 and 15 minutes, even more preferably between 5 and 7 minutes.

The advantages of this alternative embodiment of the process according to the present invention are the following:

- process conditions can be easily controlled during cooling step e’);

- overall process times are reduced.

Advantageously, according to this embodiment, the method according to the present invention can be carried out in a continuous manner, too.

In other words, the process according to the present invention advantageously allows to obtain a composite of solid particulate material in form of granules or in form of a free-flowing powder, which is versatile and universal from the point of view of its final application.

Indeed, thanks to the optimal and even complete surface coverage of said primary particles with said at least one binder, the granules of the present composite of solid particulate material can be easily dispersed in a dispersing medium in order to obtain a concentrated stable dispersion of fine particles, for example of pigment particles.

In particular, the so-obtained composite of solid particulate material is not bound by any compatibility issue with the dispersing medium, thereby allowing its application in a wide range of dispersing media, as solvents, which can be either polar or non-polar.

Definitely, the production of a particular quantity of the composite according to the present invention determines a reduced consumption of raw materials, in particular a zero consumption of solvents, as well as a possibly zero consumption of possible further additives, whose addition to the composite according to the present invention is absolutely optional. That reduced consumption of raw materials determines a considerable advantage from the practical point of view, as well as from the economic point of view.

In addition, the composite according to the present invention proves to be totally convenient from the point of view of the storage, transport and packaging thereof, as well as of the costs associated to those operations.

Indeed, the composite according to the present invention determines some advantages from the practical and economic point of view also in relation to the reduced occupied volume.

Furthermore, when said at least one solid particulate material is a pigment, the high pigment concentration in the present composite and the fine dispersion which can be obtained by dispersing it in the final dispersing medium allows “strong hues” to be obtained, which cannot be obtained with traditional liquid composition and pastes.

In general, the composite according to the present invention proves to be particularly stable and resistant from the physical-mechanical point of view, as well as it shows a marked ease of handling and processability, both in the production context, for example inside machineries or pipes of the production area or packaging area, and on the occasion of the use thereof, when added to the final dispersing medium.

In addition to what is mentioned above, as it will be seen hereafter with reference to the detailed description and to the examples, the method according to the present invention has the following advantages:

- low conversion costs in relation to

1) a low energy consumption and limited power absorptions, 2) zero CO2 emission, since almost the total thermal demand is provided and generated from friction forces during aforementioned step of disaggregating;

3) short process times,

4) a low labour incidence,

5) a high efficiency and productivity,

6) a low process complexity;

7) low CAPEX for acquiring, installing, and servicing of the overall plant; as well as,

- high quality of the so-obtained product in relation to the colouring properties thereof, if the solid particle material is a pigment, and to the easy dispersion thereof in the final dispersing medium, as previously investigated in detail and as it will be seen later in relation to the detailed description.

The features and advantages of the present invention will be more apparent from the detailed description, comprising experimental examples provided hereinbelow, of some modes of implementation of the process according to the present invention, provided by way of a non limiting example with reference to the accompanying drawings.

Figures

Figure 1 shows a schematic representation of a plant suitable for carrying out the process according to a particular embodiment of the present invention.

Figure 2 is a diagram showing the particle size distribution of the coated primary particles of a composite as obtained in Example 1.

Figure 3 shows color performances of a composite as obtained in Example 1.

Figure 4 is a diagram showing the particle size distribution of the coated primary particles of a composite as obtained in Example 5.

Figure 5 is a diagram showing the particle size distribution of the coated primary particles of a composite as obtained in Example 8.

Figure 6 is a diagram showing the particle size distribution of the coated primary particles of a composite as obtained in Example 18 not according to the present invention.

Figure 7 is a diagram showing the particle size distribution of the coated primary particles of a composite as obtained in Example 21 not according to the present invention.

Detailed description

At Figure 1 is illustrated a plant 1 comprising a high shear mixer granulator 10 and a cooler 20, this plant is adapted to carry out the process according to a particular embodiment of the present invention.

It is evident that the high shear mixer granulator 10 represented at Figure 1 is adapted to carry out the process according to another particular embodiment of the present invention which does not require a cooler and optionally provides for carrying out the cooling step in said high shear mixer granulator 10.

In particular, high shear mixer granulator 10 comprises a hollow body 11 having at least one inlet opening 12 and at least one discharge opening 13, a heating and/or cooling jacket 14 to bring and/or keep the temperature of said hollow body 11 to a first predetermined value of temperature, and a rotating screw shaft 15 arranged in said hollow body 11, whereon two impellers 16 are mounted in series.

Through the inlet opening 12, the solid particulate material and the binder can be introduced into said hollow body 11 of the high shear mixer granulator 10, thereby carrying out aforementioned steps b’) and c’).

In particular, said disaggregating step b’) may be carried out by subjecting said solid particulate material to the action of the two impellers 16 in rotation and in the presence of the binder.

The so-obtained mixture of the solid particulate material and the binder may be brought to or maintained at a first predetermined value of temperature, which is comprised between 30°C and 150°C, by means of the heating and/or cooling jacket 14, thereby obtaining primary particles coated by said binder.

Step cj and dj then can accordingly be carried out, thereby obtaining aggregates from the mixture of the solid particulate material and the binder; then said aggregates may be discharged from the high shear mixer granulator 10 through the discharge opening 13.

Said aggregates may finally be fed into the cooler 20 through at least one inlet opening 22 of a hollow body 21. Cooling step e j may this way accordingly be carried out.

The hollow body 21 of the cooler 20 comprises at least one discharge opening 23, a cooling jacket 24 to cool the hollow body 21 to a second predetermined value of temperature and a rotating screw shaft 25 arranged in said hollow body 21 , whereon two impellers are mounted in series.

The cooler 20 is therefore suitable for carrying out cooling step ej.

By means of the disclosed plant 1 , said primary particles coated by said binder may then be aggregated into aggregates and then a cooling step ej may be carried out by cooling said aggregates obtained from said mixture of the solid particulate material and the binder under the action of said at least one impeller 26. The hollow body 21 can indeed be cooled by means of the cooling jacket 24.

The so-obtained composite of solid particulate material may then be discharged from the cooler 20 through the discharge opening 23. Step fj can this way be carried out.

According to the present disclosure the pigments or fillers which can be used for the purposes of the present invention are all substances which absorb a part or all the light spectrum and reflect the complementary part thereof, forming the visible colour.

Among other commercial binders (wetting-dispersing agents), the following may be used with reference to the Examples according to the present invention:

- Disperbyk-180 (alkylol ammonium salt of a phosphoric acid ester);

- Cliqsperse LP2004-1 (amine-functionalized styrene-maleic anhydride imide copolymer);

Disperbyk-2013 (Styrene-maleic anhydride copolymer with quaternized ammonium groups) .

Among other solid particulate solid materials, the following pigments may be used:

- titanium oxide pigments in all their different inorganic surface treatments (PW6);

- yellow pigments such as PY 184; PY 138; PY 139; PY 42; PY 216; PY 74; PY 109; PY 119; PY 83; PY 65; PY 151; PY 53; PY 110; PY 3; PY 154; PY 150; PY 17; PY 13; PY 14; PY 216; PY 199; PY 128; PY 109; PY 168;

- orange pigments such as PO 73; PO 34; PO 36; PO 13; PO 61; PO 71; PO 64; PO 16; PO 83; PO 62; PO 180; - red pigments such as P.Red 101; P.Red 254; P.Red 122; P.Red 177; P.Red 179; P.Red 170; P.Red 23; P.Red 202; P.Red 146; P.Red 168; P.Red 166; P.Red 112; P.Red 207; P.Red 185; P.Red 60; P.Red 38; P.Red 214; P.Red 144; P.Red 254; P.Red 255;

- violet pigments such as PV 19; PV 23; PV 37;

- blue pigments such as PB 15:0; PB 15: 1; PB 15:2; PB 15:3; PB 15:4; PB 60; PB 28;

- green pigments such as PG 7; PG 17; PG 36;

- brown pigments such as P. Brown 24;

- black pigments such as P. Black 6; P. Black 7; P. Black 11.

In particular, in the composite of solid particulate material the primary solid particles of this solid particulate material have a particle diameter D50 (by number) in the range from 0.5 pm to 3,5 pm.

Unless otherwise indicated, when in the present invention the particle diameter D10, D50 and D90 of the composite of solid particulate material is indicated, it is referred to a particle diameter (by number) of the primary solid particles measured for the composite of solid particulate material by dispersing it in a solvent and analysing the so- obtained dispersion with a laser particle size analyser, for example, with a laser Beckman Coulter Particle Size Analyzer, optical model Fraunhofer. rf780z.

The particle size of the primary solid particles in the composite of solid particulate material may be obtained by dispersing it in an appropriate solvent vehicle, for example, butyl acetate.

The binder is completely solubilized in the tested conditions, and therefore the apparatus measures only the size of the primary solid particles dispersed in solvent. DIO is greater than or equal to the diameter of 10% of the particles in a given population; D50 is greater than or equal to the diameter of 50% of the particles in the population; and D90 is greater than or equal to the diameter of 90% of the particles in the population. Primary solid particles in the composite of solid particulate material in all the embodiments of the invention preferably has also a particle diameter D90 (by number) in the range of 0.9 pm to 4 pm.

Primary solid particles in the composite of solid particulate material in all the embodiments of the invention preferably has also a particle diameter D10 (by number) in the range of 0.5 pm to 1 pm.

Primary solid particles in the composite of solid particulate material in all the embodiments of the invention preferably has also a particle diameter D50 (by number) in the range of 0.5 pm to 3.5 pm.

In order to check the physical features and the colour and the dispersibility of the composite of solid particulate material according to the present invention, as well as the convenience of use thereof in terms both of processability and of colouring ability, the method according to the present invention has been carried out on the occasion of several tests which follow. The machinery used to perform the method according to the present invention in those tests are a 13-liters or a 50-liters Turbo-Mixer apparatus of the company Plas Mec Sri.

Optionally, downstream to the turbo-mixer apparatus a cooler was provided. Some specific sample of the composite according to the present invention was subjected to a test for measuring the volume-based particle size with a Digital Electromagnetic Sieve Shaker of Filtra Vibration mod. FTL 0200. In some cases, the mean diameter of the primary particles, coated by said at least one binder, which constitute the composite of solid particulate material, is measured with a Beckman Coulter particle size analyser having an optical model Fraunhofer, Rf780z. The colour of some composite thereby obtained has been analysed by CIELab colour test.

CIELab colour test mathematically describes all perceivable colours in the three dimensions: L for lightness and a and b for the colour components green-red and blue-yellow. The CIELab colour coordinates were measured with a spectrophotometer Minolta Mod. CM-3600 A.

Examples according to the present invention

Example 1

The method according to the present invention was carried out by disaggregating step and then agglomerating 4500 g of T1O2 PW6 white pigment (as Ti Pure R-960 by the firm Chemours) with 500 g of the binder Disperbyk-180 (provided by the firm Byk).

The composite of solid particulate material thereby obtained was called preparation PG 002 (pigment concentration 90%) and had a granular and homogeneous aspect. The method was carried out in a high shear mixer granulator; the granulator was a 13 Lt Turbo-Mixer of the company Plasmec Sri provided with 4 impellers and having a capacity of 13 liters.

Firstly, during disaggregating step the rotor of the Turbo-Mixer was activated for 8 minutes at a peripheral speed of 24 m/sec; the temperature reached was 120°C.

Then, during aggregation step the rotor of the Turbo-Mixer was activated for 10 minutes at a peripheral speed of 12.3 m/sec; the temperature reached was 110°C. The volume-based particle size of the composite was in the range of 150 pm and 250 pm.

The mean diameter of the primary particles, which were coated by said at least one binder, was measured, too. Figure 2 is a graph showing the dimensional values of those solid primary particles, namely the fineness of grind, analyzed in butyl acetate dispersion by means of said laser Particle Size Analyzer.

The mean diameter size D50 (by number) of the so-obtained coated primary particles was 0.500 pm. Example 2

The PG 002 of Example 1 underwent a CIELAB test for measuring color performances, with special regard to power coating applications.

From Figure 3, it is evident that the composite of Example 1 had better color performances with respect to titanium oxide reference product (Tiona R960).

Example 3

The PG 002 of Example 1 preparation underwent a grindometer test by dispersing it in waterborne system, as formulated in the following dispersion (total weight lOOg): Preparation PG 002 = 36 g Distilled water = 43.7 g Byk 2013 = 17.9 g DMEA = 0.9 g

Byk 024 = 1.5 g The result of the grindometer test was < 10 pm.

Example 4

The PG 002 of Example 1 preparation underwent a grindometer test by dispersing it in solventborne system, as formulated in the following dispersion (total weight lOOg):

Preparation PG 002 = 65 g

Vialkyd AC 451n/70SNB = 20 g

PMA = 15

The result of the grindometer test was < 10 pm. Example 5

The method according to the present invention was carried out by disaggregating and then agglomerating 3200 g P Red 254 (available as Cinilex SR1C by the firm Cinic) with 800 g of the binder Disperbyk-180 (provided by the firm Byk) . The composite of solid particulate material thereby obtained was called preparation PG 301 (pigment concentration 80%) and had a granular and homogeneous aspect.

The method was carried out in a high shear mixer granulator; the granulator was a 13 liters disaggregating-mixing Turbo-Mixer of the company Plas Mec Sri provided with 4 rotors.

Firstly, during disaggregating step the process time was 30 minutes at a peripheral speed of 31 m/sec; the temperature reached was 140°C.

Then, during aggregation step the rotor of the Turbo-Mixer was activated for 25 minutes at a peripheral speed of 20 m/sec; the temperature reached was 110°C. Figure 4 is a graph showing the dimensional values of those primary particles, namely the fineness of grind, analyzed in butyl acetate dispersion by means of said laser Particle Size Analyzer.

The mean diameter size D50 (by number) of the so-obtained coated primary particles was 0.256 pm.

The volume-based particle size of the composite was in the range of 60- 100 60 pm to 100 pm (free-flowing powder).

Example 6

PG 301 preparation of Example 5 underwent a grindometer test by dispersing it in water-borne system, as formulated in the following dispersion (total weight lOOg):

Preparation PG 301 = 43.8 g

Distilled water = 43.7 g

Tego Dispers 650 (Evonik) = 10.5 g

DMEA = 0.5 g

Byk 024 = 1.5 g

The result of the grindometer test was < 10 pm.

Example 7

The method according to the present invention was carried out by disaggregating and then agglomerating 12800 g of the pigment P Red 254 (available as Cinilex SR 1C by the firm Cinic) with 3200 g of the binder Disperbyk-180 (provided by the firm Byk).

The composite of solid particulate material thereby obtained was called preparation PG 302 (pigment concentration 80%) and had a granular and homogeneous aspect. The granulator was a 50 Lt Turbo-Mixer of the company Plas Mec Sri provided with 2 impellers and having a capacity of 50 liters.

The granulator rotor of the granulator was activated for 15 minutes at a peripheral speed of 35 m/sec; the temperature reached was 120°C. After 15 minutes a powdered-like composition was discharged in a cooler with 2 impellers and having a capacity of 100 liters.

The rotor of the cooler was activated for 4 minutes at a peripheral speed of 10 m/sec; the temperature final reached was 35°C.

The volume-based particle size of the so-obtained composite particle additive was about 2000-3000 pm.

Example 8

The method according to the present invention was carried out by disaggregating and then agglomerating 4500 g of P.Brown 24 (available as Heucodur Yellow 2550 by the firm Heubach) with 500 g of the binder Disperbyk-180 (provided by the firm Byk).

The composite of solid particulate material thereby obtained was called preparation PG 70 (pigment concentration 90%) and had a granular and homogeneous aspect.

The method was carried out in a high shear mixer granulator; the granulator was a 13 Lt Turbo-Mixer of the company Plas Mec Sri provided with 4 impellers.

Firstly, during disaggregating step the granulator rotor of the 13 Lt turbo-mixer was activated for 25 minutes at a peripheral speed of 24 m/sec; the temperature reached was 125°C. Then, during aggregation step the rotor of the Turbo-Mixer was activated for 15 minutes at a peripheral speed of 14,8 m/sec; the temperature reached was 110°C. The volume-based particle size of the composite was in the range of 200 pm to 700 pm.

The mean diameter of the primary particles-was measured, too.

Figure 5 is a graph showing the dimensional values of those primary particles, namely the fineness of grind, analyzed in butyl acetate dispersion by means of said laser Particle Size Analyzer.

The mean diameter D50 (by number) of those coated primary particles was 0.663 pm.

Example 9 The PG 70 preparation of Example 8 underwent a grindometer test by dispersing it in water-borne system, too, as formulated in the following dispersion (total weight lOOg):

Preparation PG 70 = 50 g

Distilled water = 36.7 g Nuosperse FN 265 (Elementis) = 11.3 g

DMEA = 1 g

Byk 024 = 1 g

The result of the grindometer test was < 10 pm.

Example 10 The method according to the present invention was carried out by disaggregating and then agglomerating 3000 g P Red 254 (available as Cinilex SR2P by the firm Cinic) with 900 g of the binder Cliqsperse LP2004-1 (provided by the firm CLIQ Swiss Tech).

The composite of solid particulate material thereby obtained was called preparation PG 307 / 1 (pigment concentration 77%) and had a granular and homogeneous aspect.

The method was carried out in a high shear mixer granulator; the granulator was 13 liters disaggregating-mixing Turbo-Mixer of the company Plas Mec Sri provided with 4 rotors.

Firstly, during disaggregating step the process time was 35 minutes at a peripheral speed of 31 m/sec; the temperature reached was 145°C.

Then, during aggregation step the rotor of the Turbo-Mixer was activated for 20 minutes at a peripheral speed of 12.3 m/sec; the temperature reached was 105°C.

The volume-based particle size of the composite was in the range of 500 pm to 1500 pm (granules dust free).

Example 11

PG 307/ 1 preparation of Example 10 underwent a grindometer test by dispersing it in solvent-borne system, as formulated in the following dispersion (total weight lOOg):

VIALKYD AC 451 = 51.40 g

Butanol = 7.00 g

Shellsol A = 17.20 g Cliqsperse LP2004-1 = 4.40 g

PG 307/ 1 = 20.00 g

The result of the grindometer test was < 10 pm.

Example 12

PG 307/ 1 preparation of Example 10 underwent a grindometer test by dispersing it in water-borne system, as formulated in the following dispersion (total weight lOOg):

Water = 78.80 g

PG 307/ 1 = 19.50 g

BYK-011 = 1.70 g

The result of the grindometer test was < 10 pm. Hence, the preparation PG 307 / 1 was suitable for both solvent-borne and water-borne applications.

Example 13

The method according to the present invention was carried out by disaggregating and then agglomerating 2125 g P Black 7 (available as Raven 14 by the firm Birla) with 375 g of the binder Cliqsperse LP2004- 1 (provided by the firm CLIQ Swiss Tech).

The composite of solid particulate material thereby obtained was called preparation PG 905 (pigment concentration 85%) and had a granular and homogeneous aspect.

The method was carried out in a high shear mixer granulator; the granulator was 13 liters disaggregating-mixing Turbo-Mixer of the company Plas Mec Sri provided with 7 rotors.

Firstly, during disaggregating step the process time was 25 minutes at a peripheral speed of 25 m/sec; the temperature reached was 145°C.

Then, during aggregation step the rotor of the Turbo-Mixer was activated for 20 minutes at a peripheral speed of 12.3 m/sec; the temperature reached was 110°C.

The volume-based particle size of the composite was in the range of 80 pm to 200 pm (free-flowing powder). Example 14

PG 905 preparation of Example 13 underwent a grindometer test by dispersing it in solvent-borne system, as formulated in the following dispersion (total weight lOOg): VIALKYD AC 451 = 42.50 g

Butanol = 4.70 g

Shellsol A = 36.60 g

PG 905 = 16.20 g

The result of the grindometer test was < 10 pm. Example 15

PG 905 preparation of Example 13 underwent a grindometer test by dispersing it in water-borne system, as formulated in the following dispersion (total weight lOOg):

Water = 82.80 g PG 905 = 16.20 g

BYK-011 = 1.00 g

The result of the grindometer test was < 10 pm. Hence, the PG 905 preparation was suitable for both solvent-borne and water-borne applications. Example 16

The method according to the present invention was carried out by disaggregating and then agglomerating 2.000 g of P.Blue 15:3 pigment (Phtalo Blue pigment available as Wynamon Blue 515303 by the firm Heubach) with 500 g of the binder Disperbyk-2013 (provided by the firm Byk).

The composite of solid particulate material thereby obtained was called preparation XC 501/2 (pigment concentration 80%) and had a granular and homogeneous aspect. The method was carried out in a high shear mixer granulator; the granulator was a a 13 Lt Turbo-Mixer of the company Plas Mec Sri provided with 4 impellers and having a capacity of 13 liters.

Firstly, during disaggregating step the granulator rotor of the Turbo- Mixer was activated for 21 minutes at a peripheral speed of 14,8 m/sec; the temperature reached was 112°C.

Then, during aggregation step the rotor of the Turbo-Mixer was activated for 25 minutes at a peripheral speed of 12.3 m/sec; the temperature reached was 120°C.

The volume-based particle size of the composite was of about 700 pm. Example 17

XC 501/2 preparation of Example 16 underwent a grindometer test by dispersing it in waterborne system, as formulated in the following dispersion (total weight lOOg):

Preparation PG 501 = 43.8 g Distilled water = 43.7 g

Nuosperse FN 265 (Elementis) = 10.5 g

DMEA = 0.5 g

Byk 024 = 1.5 g

The result of the grindometer test was < 10 pm. Examples not according to the present invention

Example 18

The method according to the present invention was carried out by disaggregating and then agglomerating 3200 g of P.Blue 15:3 pigment (Phtalo Blue pigment available as Hostaperm Blue B2G-L by the firm Clariant) with 800 g of the binder Disperbyk-2055 (modified polyacrylate with amine groups which is provided by the firm Byk) .

The composite of solid particulate material thereby obtained was called preparation PG 501 (pigment concentration 80%) and had a granular and homogeneous aspect.

The method was carried out in a high shear mixer granulator; the granulator was a a 13 Lt Turbo-Mixer of the company Plas Mec Sri provided with 4 impellers and having a capacity of 13 liters.

Firstly, during disaggregating step the granulator rotor of the Turbo- Mixer was activated for 35 minutes at a peripheral speed of 36 m/sec; the temperature reached was 120°C.

Then, during aggregation step the rotor of the Turbo-Mixer was activated for 15 minutes at a peripheral speed of 12.3 m/sec; the temperature reached was 110°C. Figure 6 is a graph showing the dimensional values of those primary particles, namely the fineness of grind, analyzed in butyl acetate dispersion by means of said laser Particle Size Analyzer.

The mean diameter size D50 (by number) of the so-obtained coated primary particles was 0.203 pm. The volume-based particle size of the composite was of about 1060 pm. Example 19 PG 501 preparation of Example 18 underwent a grindometer test by dispersing it in waterborne system, as formulated in the following dispersion (total weight lOOg):

Preparation PG 501 = 43.8 g Distilled water = 43.7 g

Nuosperse FN 265 (Elementis) = 10.5 g

DMEA = 0.5 g

Byk 024 = 1.5 g

The result of the grindometer test was < 10 pm. Example 20

PG 501 preparation of Example 18 underwent a test for the evaluation of gloss properties with the technique DIN 67530, by means of the instrument Micro Tri Gloss, provided from the firm Byk Gardner, and under the following conditions: 5% let down; application on BYK-Chart, 200 pm spiral applicator; drying for 15 min at room temperature and for 15 min at 60°C.

Results:

Gloss/20 = 47

Gloss/60 = 75 Example 21

The method according to the present invention was carried out by disaggregating and then agglomerating 4250 g of P.Y 42 (available as Bayferrox 3910 by the firm Lanxess) yellow pigment with 750 g of the binder Disperbyk-2055 (provided by the firm Byk). The composite of solid particulate material thereby obtained was called preparation PG 101 (pigment concentration 85%) and had a granular and homogeneous aspect.

The method was carried out in a high shear mixer granulator; the granulator was a 13 Lt Turbo-Mixer of the company Plas Mec Sri provided with 4 impellers.

Firstly, during disaggregating step the granulator rotor of the 13 Lt Turbo-Mixer was activated for 25 minutes at a peripheral speed of 31 m/sec; the temperature reached was 130°C. Then, during aggregation step the rotor of the Turbo-Mixer was activated for 15 minutes at a peripheral speed of 5 m/sec; the temperature reached was 100°C.

The volume-based particle size of the composite was in the range of 150 pm to 300 pm. The mean diameter of the primary particles, which were coated by said at least one binder, was measured, too.

Figure 7 is a graph showing the dimensional values of those primary particles, namely the fineness of grind, analyzed in butyl acetate dispersion by means of said laser Particle Size Analyzer. The mean diameter size D50 (by number) of those coated primary particles was 0.820 pm.

Example 22

The PG 101 preparation of Example 21 underwent a grindometer test by dispersing it in solvent-borne system, as formulated in the following dispersion (total weight lOOg), using a dissolver for 50 min at 4000 rpm:

Preparation PG 101 = 56.68 g Vialkyd AC 451n/70SNB = 24.44 g

PMA = 18.88

The result of the grindometer test was < 10 pm.

Example 23 The PG 101 preparation of Example 21 underwent a grindometer test by dispersing it in waterborne system, too, as formulated in the following dispersion (total weight lOOg):

Preparation PG 101 = 43.8 g

Distilled water = 43.7 g Nuosperse FN 265 (Elementis) = 10.5 g

DMEA = 0.5 g

Byk 024 = 1.5 g

The result of the grindometer test was < 10 pm.

Example 24 The method according to the present invention was carried out by disaggregating and then agglomerating 3200 g of P Y 139 (available as Paliotol 2140 HD by the firm Basf) yellow pigment with 800 g of the binder Byk-2055 (provided by the firm Byk).

The composite of solid particulate material thereby obtained was called preparation PG 102 (pigment concentration 80%) and had a granular and homogeneous aspect.

The method was carried out in a high shear mixer granulator; the granulator was a 13 Lt Turbo-Mixer of the company Plas Mec Sri provided with 4 impellers. The granulator rotor of the turbo-mixer was activated for 1 minute at a peripheral speed of 6 m/sec and, subsequently, for 15 minutes at a peripheral speed of 31 m/sec during disaggregating.

Then, during aggregation step the rotor of the Turbo-Mixer was activated for 20 minutes at a peripheral speed of 25 m/sec; the temperature reached was 130°C.

The volume-based particle size of the composite was in the range of 80 pm to 200 pm.

Example 25 The PG 102 preparation of Example 24 underwent a grindometer test by dispersing it in solvent-borne system, as formulated in the following dispersion (total weight lOOg), using a dissolver for 50 min at 4000 rpm:

Preparation PG 102 = 34.0 g

Vialkyd AC 451n/70SNB = 12.5 g Disperbyk 2013 - 111 = 0.3 g

PMA = 53.2

The result of the grindometer test was < 10 pm.

The PG 102 preparation underwent also a grindometer test by dispersing it in water-borne system, too, as formulated in the following dispersion (total weight lOOg):

Preparation PG 102 = 31.9 g

Distilled water = 43.10 g

Byk 2013 (Byk) = 22 g

DMEA = 2 g Byk 024 = 1 g

The result of the grindometer test was < 10 mih.

Example 26

PG 102 preparation of Example 24 underwent a test for the evaluation of gloss properties with the technique DIN 67530, by means of the instrument Micro Tri Gloss provided by the firm Byk Gardner, and under the following conditions: 5% let down; application on BYK-Chart, 200 pm spiral applicator; drying for 15 min at room temperature and for 15 min at 60°C. Haze properties were evaluated according to the ASTM D1003 and ISO 13468 standard tests.

Gloss and haze of PG 102 preparation were compared with gloss and haze of a control pigment composition.

Results (PG 102): Gloss/20 = 78

Haze = 107

Results (Control):

Gloss/20 = 30

Haze = 270.