DESC:FIELD OF THE INVENTION

The present invention relates to solvent based colorant for decorative and wood coating applications, and method of preparation of pigment dispersions (colorants) exclusively for solvent based coatings that are machine tintable.

BACKGROUND ART

Dispersions of primary pigment particles in an aqueous or non-aqueous liquid are generally employed for liquid coating compositions. Aggregation and agglomeration are the major problems due to natural tendency of the pigment particles to stick together in the course of manufacture and storage affecting the mechanical properties of coating compositions made using these pigments, as well as introducing visual defects, such as specks and streaks in the final product. The type and amount of pigment dispersion used is generally limited by the compatibility of the pigment dispersion with the other components of the liquid coating composition, the processing conditions used during the manufacturing process and the desired properties of the coating compositions being made. Manufacturers can use various techniques, such as surface coating and micronization of pigment particles to make dispersion easier and to minimize the aggregates present in a pigment dispersion used in a liquid coating composition.

Colorants is a broader term than pigment dispersions, often defining a substance (either liquid or dry) that is added to change the color of a material or surface. They contain pigment dispersion either in liquid form or as solid particles which can be easily dispersed, stabilized or suspended in a vehicle, such as water, solvent or resin.

Prior art on solvent based colorants have short comings with respect to accelerated stability (oven and weatherability test), humectancy, machine tintable, type of resin, applications (sprayable), compatibility, etc. In this regard urea aldehyde resin may play a pivotal role. The traditional Aldehyde Resins produced from auto-condensed aldehydes are very rarely used in coatings. However the same is not true for urea modified aldehyde resins which has been reported to be used as coating additive to improve gloss, body and UV resistance and are known as ideal “grinding resins” for pigment pastes because of their high pigment binding power and universal compatibility and, references are invited to the following:

US20060032401A1 directed to colorant compositions suitable for industrial coating applications comprising an aldehyde-ketone resin, distilled tall oil, a non-aqueous solvent, a surfactant and an organic or inorganic pigment.

Colorant composition for paint products, US5985987A is directed to colorants (colorant pastes) to use for tinting of paint products. The colorants contain:
2-75 wt-% (A) pigment component comprising of one or more organic and/or inorganic pigments, 10-60 wt-% (B) diluent component comprising of one or more organic solvents other than aliphatic alcohols or aromatic hydrocarbons, wherein 20-100% of the total weight of the diluent consists of a biodegradable ester of lactic acid and an alcohol, preferably ethyl or isopropyl lactate,
10-50 wt-% (C) binder component comprising one or more binders soluble in the diluent (B), wherein 70-100% of the total weight of the binder consists of a ketone aldehyde, ketone and/or aldehyde resin soluble in aliphatic hydrocarbons and 0-30% of the total weight of the binder consists of other binders commonly used in colorants, for example acrylic, alkyd or polyester resin, and 0-5 wt-% (D) additive component suitable for use in colorants.
The binders and additives may be delivered undiluted (solvent-free) or they may contain as a diluent organic solvents that in the colorant are considered as a part of the diluent component (B).

CN107936700A discloses preparation method of iron oxide-based oily coloring pastes. The coloring pastes are prepared from aldehyde ketone resins (CF A81), iron oxide-based pigments, wetting dispersants, thickening anti-settling agents, and environmentally friendly solvents. The oily color paste has strong universality to a resin paint, has good compatibility with various resins (such as epoxy resin, acrylic resin and alkyd resin). Two different wetting and dispersing agent (DISPERBYK-163 and DISPERBYK-2150) are used for the formulation. Preferably, the wetting dispersing agent is the heavy polymer solution containing pigment affinity groups. Specifically, instituted Wetting dispersing agent is stated as one or both of DISPERBYK-163, DISPERBYK-2150 and TEGO Dispers 670. However, the advancement is limited to only for iron oxide pigments and, moreover it is a paste and does not suggest dispersion including varieties of organic and inorganic pigments enabling machine tintability.

CN103305062A is about environment-friendly general color paste and preparation method thereof which is prepared consisting aldehyde ketone resin wet dispersing agent, anti-settling agent, toner and composite environment-friendly solvent. The color paste has the excellent performance of high solid content, low viscosity, low organic volatile and the like, meanwhile has good color keeping and light maintaining performance, is not prone to aberration change or yellowing and has good weather resistance and storage stability. Use and performance are not affected after the color paste is placed for more than one year under normal temperature state.

US5075366 discloses a masterbatch, i.e. a composition having a high content of a pigment or a dye and a polymer, consisting essentially of
(a) a resin such as an urea-aldehyde resin,
(b) a second component Selected from the group of (b1) citric, acetylcitric or tartaric acid glycol polyalkyleneglycol esters and (b2) citric, acetylcitric or tartaric acid mono alcohol esters in admixture with polyalkyleneglycols, and
c) dyes and/or pigments and/or additives.

MICROLENGRUA (Ciba Speciality Chemicals Inc.) is a mixture of 45 to 60% of an organic pigment, 2% of a dispersing agent (ethoxylated amine), 6.5 to 8.6% of polyethylene wax (LMWPE) and 46.5 to 29.4% of an urea aldehyde resin (Laropal(R) A81).

CN111925692A discloses universal color paste, comprising ketone-aldehyde resin solution, polyether polyol, pigment, filler and dispersant wherein the dispersant is a polyurethane dispersant and the pigment is carbon black. Ketone-aldehyde resin is a synthesized liquid butyl ketone-aldehyde resin solution, and the solid content is not less than 92%

CN107189555A discloses a kind of solvent based coating general color paste and preparation method thereof and is made up of Pigment, aldehyde resin, solvent, wetting dispersing agent 3-10% wherein wetting dispersing agent is a family macromolecule block copolymer and demonstrates high solids content, low viscosity, good storage stability and compatibility with other resins.

US20090182081A1 proposes coating of inorganic pigments with aldehyde or ketone resins. Coating of inorganic pigments with aldehyde or ketone resins and at least one dispersant, comprising a chemical compound consisting of particles of solid organic and inorganic substances, both defined as pigments, in that they absorb a fraction of the light and reflect the complementary part thereof, coated with aldehyde or ketone resins. The latter are deposited on the surface of the pigment by means of a process which envisages melting of the resin, wetting and coating of the entire surface of the pigment with the resin in the melted state, and cooling and atomization by means of mechanical systems operating in temperature conditions lower than 10° C., by cryogenic processes.

DE102007047586A1 relates to coating compositions comprising at least one binder and a formaldehyde-free, carbonyl-hydrogenated ketone-aldehyde resin based on formaldehyde and their use. The Coating compositions contains
A) carbonyl-hydrogenated ketaldehyde aldehyde resin; B) binder including polyurethanes, polyacrylates, polyethers, saturated and / or unsaturated polyesters and copolyesters, alkyd resins, and C) colorant and / or fillers selected from milori blue, titanium dioxide, iron oxides, metal pigments, Carbon blacks, carbonates, sulphates, silicates and D) additive, including organic solvents, Water, surfactants, oxygen and / or Free radical scavengers, catalysts, light stabilizers, color lighteners, Photosensitizers and initiators,
US20100004387A1 reveals a process for the production of a particle composition containing, at least one resin (an aldehyde, ketone and/or acrylic resin) and at least one pigment and comprises the steps of: (a) extrusion, in a co-rotating twin-screw extruder, of a mixture containing said at least one resin and said at least one pigment without induced heating, using only the heat developed naturally by the cutting and friction forces inside the extruder;
(b) subsequent extrusion, with induced heating, of the mixture obtained from the extrusion according to step (a);
(c) granulation of the mixture thus obtained providing granules with an average diameter less than 2 microns and a greater homogeneity than the known processes.

EP2597122A1 reveals coating of organic and inorganic pigments with aldehyde or ketone resins, comprising a chemical compound consisting of particles of solid organic and inorganic substances, both defined as pigments, in that they are substances which absorb a fraction of the light and reflect the complementary part thereof, coated with aldehyde or ketone resins. Particle composition consisting of pigments coated with at least one aldehyde and/or ketone resin, said resin having an average molecular weight of between 800 and 2000 Da and melting point of between 70° and 130°C.

EP2361956A1 teaches composition of pigments soluble in water and/or in organic solvents comprising:
(a) inorganic and/or organic pigment; and
(b) 0.5% to 30% by weight of a dispersing and/or wetting agent; and at least one component selected from: styrene and polyether copolymers, modified polymers having groups with high affinity for the pigments, modified polyethers having groups with high affinity for the pigments, low molecular weight polymers, etc. along with
(c) solubilization accelerating agent, (d) inorganic filler selected from barium sulphate, kaolin and silicon dioxide; (e) binding agent selected from modified ketone polymers with groups having an affinity with the pigments, solid bonding resins and lignin sulphonate; (f) at least one acrylic, aldehyde and/or ketone resin;(g) rheological agent; (h) anti-foaming agent. is a siloxane polyether copolymer.
However, the above prior art is for tablet, granules, powder form of pigment composition, soluble in water and/or solvent, whose use is limited by means of solubilization and includes siloxane polyether as an anti-foaming agent and not any polysiloxane copolymer.
EP0846149B1 (USOO5985987A): disclose a colourant composition for solvent-borne paint products comprising 2-75 % by weight of a pigment component (A) consisting of one or more organic and/or inorganic pigments and possibly extender pigments, 10-60 % by weight of a diluent component (B) consisting of one or more organic solvents not being an aliphatic alcohol or aromatic hydrocarbon, 10-50 % by weight (calculated as 100 % nonvolatile matter) of a binder component (C) consisting of one or more binders soluble in the diluent component (B), and 0-5 % by weight (calculated as 100 % active matter) of an additive component (D) consisting of one or more additives suitable for use in colourants, characterized in that 20-100 % of the total weight of the diluent component (B) consists of a biodegradable ester of lactic acid and a C-|-C10-alcohol and 70-100 % of the total weight of the binder component (C) consists of a ketone aldehyde resin, ketone resin and/or aldehyde resin at least partially soluble in paint solvents including aliphatic hydrocarbons.
Universal colouring compositions by EP 0937760B1 characterized in that they comprise pigments, Disperbyk®-183 and 20-80% by weight of solvents, and in which the pigments Disperbyk®-183 weight ratio ranges from 0.1:1 to 15:1, said pigments includes Mid-yellow, Red for exterior use, Red oxide, Magenta, Brown oxide, Phthalo green, Phthalo blue, Carbon black, Titanium white, Yellow oxide, Yellow for exterior use .

US6734231B2 discloses easily distributable pigment compositions consisting essentially of pigment and urea aldehyde resin, wherein the weight ratio of pigment to urea-aldehyde resin is generally in the range of 40:60 to 90:10, a process for their production and their use in pigmenting high molecular weight organic materials.

US19577512B2 proposed solvent borne alkyd paints composition containing a universal colorant of organic or inorganic pigment, a solvent borne alkyd base paints and a fatty acid amidoamine, where the universal colorant with organic pigment comprises deionized water, TEGO R disperser 653 (dispersant, modified polyether), TEGO R Foamex 810 (defoamer, polyether siloxane copolymer), Hostaperm Pink E (organic pigment- quinacridone red 122), MergalV541 (in can preservative) and
Universal colorant with inorganic pigment comprises deionized water, TEGO R disperser 653 (dispersant, modified polyether), TEGOR Foamex 810 (defoamer, polyether siloxane copolymer), Bayferrox 130M (Inorganic pigment iron oxide red 101), MergalV541 (in can preservative).

POLYTONE™ UA 810 is an aldehyde resin for pigment dispersions (Iodine Color Number = 3, Hydroxyl Value ~ 40 mg KOH / gm resin, Acid Value 3 mg KOH / gm resin (Max), Saponification Value ~ 65 mg KOH / gm resin Tg ~ 57 ° C suitable for pigment dispersion and recommended formulations are
Organic pigment: Resin (25-40), Solvent (15-30), dispersing agent (10-15), anti- settling agent (0) and pigment (15-40);
Inorganic pigment: Resin (15-25), Solvent (5-15), dispersing agent (3-10), anti- settling agent (0.3-1.0) and pigment (45-65).
The above recommended levels from the commercial sources can be used for orientation, however optimal levels are determined through a series of laboratory tests.

US 2002/0187412 A1 provides for a toner composition comprising 10 to 40 wt.% of an inorganic pigment, 15 to 35 wt.% of a copolymer solution having a high molecular weight and containing a pigment affinity group such as a hydroxyl group, a carboxyl group or an amine group, 30 to 50 wt.% of a solvent and 2 to 5 wt. % of a dispersion adjuvant.

US 20080275169 A1 relates to new universal pigment preparations as virtually foam-free aqueous and also solvent borne and solvent-free pigment preparations and to their use in aqueous, solvent borne or solvent-free coating materials such as paints, varnishes, adhesives or inks, including printing inks, for example; comprising
A) 95% to 5% by weight of at least one block-copolymeric, styrene oxide-containing polyalkylene oxide, and
B) 5% to 95% by weight of a ketone-aldehyde resin, and
C) 0 to 80% by weight of at least one solvent,
the Sum of the amounts by weight of components A) to C) being 100% by weight, and
D) pigments; E) fillers, and F) 0 to 10% by weight of auxiliaries,
the amount of the sum of component A), component B), and component C) being 2%-300% by weight, based on the sum of the weights of the respective components D) and E), and it being possible for the amount of component E) in the pigment preparation also to be 0% by weight.

It is evident from above that aldehyde ketone resin is used in combination with other resin binders to improve its properties and production of all purpose pigment paste. Only few prior arts describe preparation of resin solution. In addition none of the above references teach about superior weatherability properties of the colorants in retaining high gloss after exposure to long UV hours.

Thus there is a need in the art to provide for solvent based colorants that would overcome the shortcomings of accelerated stability (oven and weatherability test), humectancy, machine tintable, type of resin, applications (sprayable), compatibility, and would also be compatible to polyester, and also alkyds, PU, PU-Acrylics, epoxy bases adapted for decorative and wood coating applications.

OBJECTS OF THE INVENTION

The primary object of the present invention is to provide for aldehyde resin solution adapted for a colourant composition/ pigment dispersion which in involving select amounts of said aldehyde resin solution, dispersing agents, compatibilizers, rheology modifiers in select solvent systems would enable said pigment dispersion (colorants) exclusively for solvent based coatings and would be machine tintable to also have improved compatibility with polyester, and also alkyds, PU, PU-Acrylics, epoxy bases for decorative and wood coating applications.

Another object of the present invention is to provide for said pigment dispersion (colorants) that would have appropriate rheology, acceptable coloristics, stable at accelerated conditions such as oven test, weatherability test, better humectancy (devoid of any nozzle blocking).

Yet another object of the present invention is to provide for a method of preparation of resin solution requiring less time to prepare 60% resin solution and a process for preparation of said colourant composition involving the same.

Summary of the Invention

In the primary embodiment the invention is directed to provide a pigment dispersion/ colourant composition compatible with solvent-borne resins comprising
(a) pigment component/s including organic, inorganic pigments, extender pigments in 5-70 wt.%,
(b) 60% aldehyde resin solution including urea-aldehyde resin or formaldehyde resin having acid value ranging from 2-7 mg KOH/gm in 18-82 wt.%,
(c) high molecular weight block copolymer with pigment affinic groups in 5-16 wt. %, and having amine value of 8-12 mg KOH/g together with any one or both of the following:
(d) controlled flocculating wetting and dispersing agent including lower molecular weight unsaturated polycarboxylic acid polymer and polysiloxane copolymer with acid value: 128-168 (mg KOH/g) in 3-5 wt.%,
(e) Pigment/Filler affinic copolymer with pigment/filler affinic groups in 2-4% wt.%.

Another embodiment of the present invention is directed to provide said pigment dispersion/ colourant composition wherein said composition optionally includes
(i) organic derivative of bentonite clay in 0.5-2 wt.%
(ii) Modified urea [Density (g/ml) @ 20 °C: 1.140-1.180, RI @ 20 °C: 1.517-1.533, NVM (%) 20 min @ 175 °C: 50-58, Color on Gardner Scale: < 7] in 0.4-1.6 wt.% as a rheology modifier favouring superior viscosity, humectancy, and stability.
(iii) co-acting polymeric dispersant/pigment derivative with Density (g/ml) @ 20 °C: 1.000-1.420, Appearance: Blue Powder, Moisture Content (%) 1 h @ 120 °C: < 4, pH: 2-5 (0.05- 1.0 %) was added under stirring for about 5-10 min at 6-8 m/sec.
(iv) diluent including organic solvent/s in the levels upto 75.
Another embodiment of the present invention is directed to provide said pigment dispersion/ colourant composition that is compatible with said solvent borne resins including Alkyd, PU, PU-Acrylic, and Epoxy resins.
Yet another embodiment of the present invention is directed to provide said pigment dispersion/ colourant composition wherein said urea-aldehyde resin is a polyaldehyde resin preferably provided in MPA and Xylol solvent in 1:1 ratio and is obtained by condensation of urea and aliphatic aldehydes,
wherein said pigments includes the pigment, PY42 (iron oxide yellow pigment), PY151 (benzimidazolone yellow), PY139 (isoindoline yellow), PR170 (naphthol red), PR122 (quinacridone red), PG7 (phthalocyanine green), PBK7 (carbon black), PO36 (benzimidazolone orange), PB15.2 (phthalocyanine blue), PB15.4 (phthalocyanine blue), PW6 (Rutile, TiO2), PR101 (iron oxide red pigment), PV23 (carbazole violet), and may also include PB15.1 (phthalocyanine blue), PB15.3 (phthalocyanine blue), PR3 (toludine red), PR112 (monoazo red), PY154 (monoazo of benzimidazolone yellow), PV19 (quinacridone violet), PY 138 (Quinophthalone yellow);
Yet further embodiment of the present invention is directed to provide said pigment dispersion/ colourant composition wherein said high molecular weight block copolymer with pigment affinic groups/ dispersant comprises one or more of the compounds selected from the group consisting of (a) phosphorus ester salts of amino-containing oligomers or polymers, (b) monoesters or diesters of phosphoric acid, (c) acidic dicarboxylic monoesters, (d) polyurethane-polyamine adducts, (e) polyalkoxylated monoamines or diamines, and (f) reaction products of unsaturated fatty acids with monoamines, diamines and polyamines, amino 10 15 25 30 35 alcohols, and unsaturated 1,2-dicarboxylic acids and their anhydrides and salts thereof and reaction products with alcohols and/or amines preferably having Amine value: 10 mg KOH/g, Density (20 °C): 0.99 g/ml, Flash point: 28 °C; and suitable high molecular weight block copolymer include DISPERBYK 163 (Solution of a high molecular weight block copolymer with pigment affinic groups having amine values (mg KOH/gm): 8.0-12.0; DISPERBYK 103 (solution of polyesteric copolymers with filler affinic groups), BYK P104S (solution of a lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer with acid value (mg KOH/gm): 128-168; DISPERBYK 2155 (Block copolymer with pigment affinic groups with Amine Values (mg KOH/gm): 42-54; EFKA FA 4608 Hydroxy-functional unsaturated modified carboxylic acid with pigment-affine groups with amine values (mg KOH/gm): 80-90.
Another embodiment of the present invention is directed to provide said pigment dispersion/ colourant composition wherein said high molecular weight block copolymer/s with pigment affinic groups/ dispersant having Density (g/ml) @ 20 °C: 1.035-1.065, RI @ 20 °C: 1.425-1.435, NVM (%) 20 min @ 150 °C: 38-42, preferably DISPERBYK-163, DISPERBYK-2150 and TEGO Dispers 670 (DISPERBYK-163, DISPERBYK-2150 and TEGO Dispers 670.
Another preferred embodiment of the present invention is directed to provide a process for preparation of said pigment dispersion/ colourant composition comprising the steps of mixing and grinding following components
(a) pigment component/s including organic, inorganic pigments, extender pigments in 5-70 wt.%,
(b) aldehyde resin solution including urea-aldehyde resin or formaldehyde resin having acid value ranging from 2-7mg KOH/gm in 18-82.wt.%,
(c) high molecular weight block copolymer with pigment affinic groups and having amine value of 8-12 mg KOH/g in 6-10 wt. %, together with any one or both of the following:
(d) controlled flocculating wetting and dispersing agent including lower molecular weight unsaturated polycarboxylic acid polymer and polysiloxane copolymer with acid value: 128-168 (mg KOH/g) in 3-5 wt.%,
(e) Pigment/Filler affinic copolymer with pigment/filler affinic groups in 2-4 wt.%,
and obtaining therefrom said pigment dispersion/ colourant composition having compatibility with polyesters extendable to PU, PU-Acrylic, Epoxy, and Alkyds bases.

Further embodiment of the present invention is directed to provide said process for the preparation of pigment dispersion/ colourant composition wherein
following pigment addition in grinding mixing stage in dyno mill, resin solution is added for flushing pigments sticking to reaction vessel that is followed by adding organic derivative of bentonite clay and said modified urea as a rheology modifier with the grinding continued to achieve desired viscosity of the millbase to 150-350 gm and finish;
thinning/ diluting with organic solvent with or without resin solution and high molecular weight block copolymer with pigment affinic groups for storing said colorant composition.

Still further embodiment of the present invention is directed to provide said process for the preparation of pigment dispersion/ colourant composition wherein
preparing carbon black colourant composition involves the following steps of mixing and grinding of the following components
(a). Mixing resin solution (~13%), and (b) solution of a high molecular weight block copolymer with pigment affinic groups and having amine value of 8-12 mg KOH/g (~6%); and (c) Solution of a lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer with acid value (mg KOH/g): 128-168
in a vessel fitted with the high speed disperser under stirring for about 5-10 min at 6-8 m/sec to have uniform mixture;
(d). adding co-acting polymeric dispersant/pigment derivative with Density (g/ml) @ 20 °C: 1.000-1.420, Appearance: Blue Powder, Moisture Content (%) 1 h @ 120 °C: < 4, pH: 2-5 (0.8%) under stirring for about 5-10 min at 6-8 m/sec.
(e). adding pigment PB7 (~9.9%), and said resin solution (~1%) followed by grinding for about 60-70 min at 18-20 m/sec;
(f). adding further organic derivative of a bentonite clay (~1.8%) and mixed it well for about 10-15 min at 18-20 m/sec, and
(g). adding solution of a modified urea and continuing grinding for 15-20 min at 18-20 m/sec.; adjusting the viscosity of the millbase to 150-350 g for dyno mill by adding resin solution (~10 %) and Three dyno mill pass are provided the finish of 7+; and
(h). collecting and storing of the colorant.

Another embodiment of the present invention is directed to provide said process for the preparation of pigment dispersion/ colourant composition wherein said preparing Carmine Red colourant composition involves the following steps of mixing and grinding of following components
a. Resin solution (~34%%),
b. Solution of a high molecular weight block copolymer [Density (g/ml) @ 20 °C: 0.985-1.000, RI @ 20 °C: 1.4770-1.4830, NVM (%) 20 min @ 150 °C: 44-46, Amine Values (mg KOHg): 8.0-12.0, Turbidity: <30] with pigment affinic groups (~8%), and c. solution of a copolymer [Density (g/ml) @ 20 °C: 1.035-1.065, RI @ 20 °C: 1.425-1.435, NVM (%) 20 min @ 150 °C: 38-42] with filler affinic groups (~2%)
in a vessel fitted with the high speed disperser for 5-10 min at 6-8 m/sec to have uniform mixture.
ii) adding pigment PR 170 (~25%) followed by grinding for 10-15 min at 18-20 m/sec,
iii) adding organic derivative of bentonite clay (~0.75%) with continuation of grinding for 40-50 min at 18-20 m/sec.
iv) adjusting the viscosity of the millbase to 80-200 g for dyno mill by adding Butyl acetate (~1 %), and resin solution (~16%) and four dyno mill pass are required to provide for the finish of 7+.
v) collecting and storing the colorant after dyno mill pass;
optionally followed by diluting/ thinning involving Xylol (~1%), butyl acetate (~1%), Resin solution (~11.25%).

Still further embodiment of the present invention is directed to provide said process for the preparation of pigment dispersion/ colourant composition wherein said preparing Red-Oxide colourant composition involves the following steps of mixing and grinding of following components
a. Resin solution (~11%),
b. Solution of a high molecular weight block copolymer [Density (g/ml) @ 20 °C: 0.985-1.000, RI @ 20 °C: 1.4770-1.4830, NVM (%) 20 min @ 150 °C: 44-46, Amine Values (mg KOHg): 8.0-12.0, Turbidity: <30] with pigment affinic groups (~6%), and c. solution of a copolymer [Density (g/ml) @ 20 °C: 1.035-1.065, RI @ 20 °C: 1.425-1.435, NVM (%) 20 min @ 150 °C: 38-42] with filler affinic groups (~4%)
in a vessel fitted with the high speed disperser for 5-10 min at 6-8 m/sec to have uniform mixture.
ii) adding pigment PR 101 (~67%) followed by grinding for 60-70 min at 18-20 m/sec,
iii) adding rheology modifier solution of a modified urea (~1%) with continuation of grinding for 15-20 min at 18-20 m/sec.
iv) adjusting the viscosity of the millbase to 150-350 g for dyno mill by adding Butyl acetate (~1.5%), and resin solution (~5.5%) and four dyno mill pass are required to provide for the finish of 7+.
v) collecting and storing the colorant after dyno mill pass,
optionally followed by diluting/ thinning involving butyl acetate (~1%), Resin solution (~2%), and solution of a high molecular weight block copolymer with pigment affinic groups (~1%).

Hereinafter, the present invention will be described in detail by way of the Figures and examples, which are not intended to limit the Scope of the present invention.

Brief description of the Figures
Figure 1. The dispersion issue in PU-Acrylic resin due to carbon black pigment flocculation (figure (a)) is resolved in accordance to the present invention through employment of solution of a select lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer (figure (b))
Figure 2. The dispersion issue in PU-Acrylic resin due to flocculation of red oxide pigment (figure (a)) was resolved with the use of select quantity of solution of a copolymer with filler affinic groups (figure (b))

DETAILED DESCRIPTION OF THE INVENTION

As discussed hereinbefore, the present invention describes colorant compositions (pigment dispersions) including diverse organic and inorganic pigments and the method of preparation of pigment dispersions (colorants) exclusively for solvent based coatings that are machine tintable. Select aldehyde resin at desired levels, variety of dispersing agents, compatibilizers, rheology modifiers, different solvents have been employed to synergistically co-act and achieve the desired properties. These colorants are compatible to polyesters and also to alkyds, PU, PU-Acrylics, epoxy bases for decorative and wood coating applications. The colorants with appropriate rheology, acceptable coloristics, stablity at accelerated conditions such as oven test, weatherability test, better humectancy (no nozzle blocking), etc. are developed in accordance to the present invention. Also a method is developed for preparation of resin solution, and this method requires much shorter time (4-5 h) to prepare the 60% resin solution.
Resin, dispersing/wetting agents, solvent/solvent combinations resulted no settling in accelerated stability test as per ASTM D 1849. These colorants showed superior weatherability properties, they retained very high Gloss even after exposure to QUV for 2500 h. The present compositions exhibited complete compatibility with any of the bases such as polyester, alkyds, PU, PU-acrylic, epoxy in terms of coloristics, dispersion, rheology, brush or spray applications. These colorants are machine tintable, and no nozzle blocking was observed due to its better humectancy.

Preferably, the aldehyde resin involved is the condensation product of urea and aliphatic aldehydes, this urea-aldehyde resin beads or flakes or lumps in solid state have acid value ranging from 2-6, colorless to light yellow appearance, the softening points ranging from 80-95 °C, density (g/ml) @ 20 °C: 1.050-1.150. The urea-aldehyde resin solution of 60% solid content in mixed xylene and methoxy propyl acetate having color on Gardner less than 1 was prepared. The non-volatile content (NVM) 60 min at 120 °C is in the range of 59-61%.

The high molecular weight block copolymer with pigment affinic groups/ dispersant comprises one or more of the compounds selected from the group consisting of (a) phosphorus ester salts of amino-containing oligomers or polymers, (b) monoesters or diesters of phosphoric acid, (c) acidic dicarboxylic monoesters, (d) polyurethane-polyamine adducts, (e) polyalkoxylated monoamines or diamines, and (f) reaction products of unsaturated fatty acids with monoamines, diamines and polyamines, amino 10 15 25 30 35 alcohols, and unsaturated 1,2-dicarboxylic acids and their anhydrides and salts thereof and reaction products with alcohols and/or amines preferably having Amine value: 10 mg KOH/g, Density (20 °C): 0.99 g/ml, Flash point: 28 °C. The examples are DISPERBYK 163 (Solution of a high molecular weight block copolymer with pigment affinic groups having amine values (mg KOH g): 8.0-12.0; DISPERBYK 103 (solution of polyesteric copolymers with filler affinic groups), BYK P104S (Solution of a lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer with acid value (mg KOHg): 128-168; DISPERBYK 2155 (Block copolymer with pigment affinic groups with Amine Values (mg KOHg): 42-54; EFKA FA 4608 Hydroxy-functional unsaturated modified carboxylic acid with pigment-affine groups with amine values (mg KOH g): 80-90.
Specifically, the wetting and dispersing agent is one or two of DISPERBYK-163, DISPERBYK 103, BYK P104S, DISPERBYK-2150, TEGO Dispers 670 (DISPERBYK-163, DISPERBYK-2150 and TEGO Dispers 670 and all can be purchased from the market).
The method developed for preparation of resin solution, enables preparation of the same in shorter time (4-5 h) wherein the resin is added to the solvent, phase wise avoiding bulk addition which will cause lump formation.

The colorant composition includes the pigment, PY42 (iron oxide yellow pigment), PY151 (benzimidazolone yellow), PY139 (isoindoline yellow), PR170 (naphthol red), PR122 (quinacridone red), PG7 (phthalocyanine green), PBK7 (carbon black), PO36 (benzimidazolone orange), PB15.2 (phthalocyanine blue), PB15.4 (phthalocyanine blue), PW6 (Rutile, TiO2), PR101 (iron oxide red pigment), PV23 (carbazol violet), and may also include PB15.1 (phthalocyanine blue), PB15.3 (phthalocyanine blue), PR3 (toludine red), PR112 (monoazo red), PY154 (monoazo of benzimidazolone yellow), PV19 (quinacridone violet), PY 138 (Quinophthalone yellow).
The colorant compositions of the present invention are designed to have compatibility with Polyesters and is extended to PU, PU-Acrylic, Epoxy, and Alkyds bases.
The colorants retained better rheology and coloristics even after subjecting to 1 month accelerated stability test. The colorants showed better gloss retention when exposed to QUV/Atlas test, in certain cases it is up to 2500 h of exposure.

Examples

Preparation of Resin Solution

Preferably, the involved aldehyde resin in the pigment dispersion/ colourant composition is the condensation product of urea and aliphatic aldehydes, this urea-aldehyde resin beads or flakes or lumps in solid state have acid value ranging from 2-6, colorless to light yellow appearance, the softening points ranging from 80-95 °C, density (g/ml) @ 20 °C: 1.050-1.150. The urea-aldehyde resin solution of 60% solid content in mixed xylene and methoxy propyl acetate having color on Gardner less than 1 was prepared. The non-volatile content (NVM) 60 min at 120 °C is in the range of 59-61%.

60% (solid content based) Aldehyde resin solution was prepared using the solvents MPA and Xylol at 1:1 ratio. The resin flakes were added in 6 stages to the solvent mixture under stirring at 6-8 m/sec to have better solubility. Otherwise the resin flakes forms swollen gel which requires more time (>10 h) to form uniform resin solution.

Example 1

Preparation of Pigment Dispersion Carbon Black

Resin solution (~13%), solution of a high molecular weight block copolymer [Density (g/ml) @ 20 °C: 0.985-1.000, RI @ 20 °C: 1.4770-1.4830, NVM (%) 20 min @ 150 °C: 44-46, Amine Values (mg KOH/g): 8.0-12.0, Turbidity: <30] with pigment affinic groups (~6%), solution of a lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer with acid value (mg KOH/g): 128-168 [Density (g/ml) @ 20 °C: 0.935-0.955, RI @ 20 °C: 1.482-1.490, NVM (%) 20 min @ 150 °C: 48-52, Turbidity: <40] (~5%) were weighed in a vessel fitted with high speed disperser. This premix was kept under stirring for about 5-10 min at 6-8 m/sec to have uniform mixture. A further co-acting and synergy aiding polymeric dispersant/pigment derivative with Density (g/ml) @ 20 °C: 1.000-1.420, Appearance: Blue Powder, Moisture Content (%) 1 h @ 120 °C: < 4, pH: 2-5 (0.8%) was added under stirring for about 5-10 min at 6-8 m/sec. This was followed by addition of pigment PB7 (~9.9%), and resin solution (~1%) was used for flushing of pigment sticking to the vessel and grinding for about 60-70 min at 18-20 m/sec, and then added organic derivative of a bentonite clay [Volatile Material (%) 2h @ 105 °C: < 3, Loss on Ignition (%) 2h @ 1000h °C: 38-41, Residue (%) on 325 mesh: < 5] (~1.8%), mixed it well for about 10-15 min at 18-20 m/sec, and a rheology modifier solution of a modified urea [Density (g/ml) @ 20 °C: 1.140-1.180, RI @ 20 °C: 1.517-1.533, NVM (%) 20 min @ 175 °C: 50-58, Color on Gardner Scale: < 7] (~1%) was added and grinding continued for 15-20 min at 18-20 m/sec., resin solution (~10 %) was used to adjust the viscosity of the millbase to 150-350 g for dyno mill. Three dyno mill pass are required to achieve the finish of 7+. The colorant after dyno mill pass was collected and stored.
Thinning using Butyl acetate (~0.5%). Resin solution (~31%), and solution of a high molecular weight block copolymer with pigment affinic groups (~4%) was done as and when required. The final colorant sample was checked for the viscosity, humectancy, and accelerated stability test, and found acceptable. The colorant was evaluated for coloristics, dispersion, overnight stability, weatherability, ease of application in Alkyd, PU, PU-Acrylic, and Epoxy bases and found acceptable.
The synergy aiding polymeric dispersant/pigment derivative aka synergist additive, absorb to the surface of the pigment and provides an anchoring spot for the dispersant to anchor on the pigment. Thus, it improves the anchoring efficiency of a dispersant, which gives better pigment stability. This polymeric dispersant shows good synergy when used in conjunction with dispersing agents to grind the black pigments. Also this polymeric dispersant is blue color in appearance provide required bluer under tone to the black pigment dispersion.
The composition/ratio, and the sequence of addition of the raw materials are critical to have acceptable properties otherwise, there will be poor color strength, increased flocculation, variation in viscosity, less compatibility with other resin bases etc.
The encountered difficulties are the inferior dispersion, accelerated stability, drying time (humectancy), acceptable color strength etc. With the above mentioned composition and sequence of raw material addition- surprisingly all the properties were found acceptable. The flocculation and floatation of carbon black pigment dispersion could be overcome by the synergistic co-action of a solution of a lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer. Representative results of initial gloss, gloss retention after 2500 h of QUV-B exposure, viscosity difference at initial and after accelerated stability test (pigment dispersion sample at 55 °C for 30 days), drying time of as such colorant (humectancy) are tabulated in Table 1.
The Figure 1 shows effect of solution of a lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer in solving the flocculation and floatation issue.

Table 1: Results for Carbon Black Dispersion.
Black pigment dispersion Initial Gloss in PU-Acrylic pastel paint Gloss retention after 2500 QUV-B Initial viscosity KU After accelerated stability
test (at 55 °C for 30 days)
Viscosity Settling
Reference 83.5 9.5 74 82 Yes
Experimental, in accordance with the present invention 88.5 27.3 68 74 No

For reference sample (commercial market sample of Carbon Black Dispersion having the viscosity in the range of 65 – 90 KU, color strength 98 – 102 %, solid 62 – 68 %), dispersion issue and accelerated stability issues with this colorant was evaluated. There was a requirement of high shear to mix to uniformly after the accelerated stability. The gloss retention after 2500 h of QUV-B was also inferior.

Table 2: Effect of concentration of controlled flocculating wetting and dispersing agent on color strength. The color strength was measured as per the test method ASTM 2066.
Trials Controlled flocculating wetting and dispersing agent (wt.%) Color strength (%) in PU-Acrylic glossy paint Color strength (%) in PU-Acrylic mat paint
1 0 72.37 75.89
2 2 89.26 93.48
3 3 101.29 102.66
4 5 102.67 103.34

As shown in Table 2, the controlled flocculating wetting and dispersing agent (the solution of lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer which can form a network kind of structures between the pigment particles and reduce the pigment-pigment interactions) when involved below 2 wt.% resulted in inferior color strength, rather than when involved between 3 - 5 wt.%, the color strength was acceptable.

Table 3: Effect of change in stage of addition/ sequence of addition of controlled flocculating wetting and dispersing agent
Trials Color strength (%) when added in thinning stage Color strength (%) when added in grinding stage
Glossy paint Mat paint Glossy paint Mat paint
Controlled flocculating wetting and dispersing agent 93.22 97.45 102.67 103.34

As shown in Table 3, when the controlled flocculating wetting and dispersing agent solution of a lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer was used in thinning stage the color strength was low and there was dispersion issue observed. When it was used in grinding stage acceptable properties were obtained.

Example 2
Preparation of Pigment Dispersion Carmine Red
Resin solution (~34%), solution of a high molecular weight block copolymer [Density (g/ml) @ 20 °C: 0.985-1.000, RI @ 20 °C: 1.4770-1.4830, NVM (%) 20 min @ 150 °C: 44-46, Amine Values (mg KOH/g): 8.0-12.0, Turbidity: <30] with pigment affinic groups (~8%), Solution of a copolymer [Density (g/ml) @ 20 °C: 1.035-1.065, RI @ 20 °C: 1.425-1.435, NVM (%) 20 min @ 150 °C: 38-42] with filler affinic groups (~2%) were weighed in a vessel fitted with the high speed disperser. This premix was kept under stirring for about 5-10 min at 6-8 m/sec to have uniform mixture. This was followed by addition of pigment PR 170 (~25%), and mixed it well for about 10-15 min at 18-20 m/sec, and then added organic derivative of a bentonite clay (~0.75%) grinding continued for 40-50 min at 18-20 m/sec. Butyl acetate (~1%), and resin solution (~16%) were used to adjust the viscosity of the millbase to 80-200 g for dyno mill. Four dyno mill pass were required to achieve the finish of 7+. The colorant after dyno mill pass was collected and stored.
Thinning using Xylol (~1%), butyl acetate (~1%), Resin solution (~11.25%), was done as and when required. The final colorant sample was checked for the viscosity, humectancy, and accelerated stability test, and found acceptable. The colorant was evaluated for coloristics, dispersion, overnight stability, weatherability, ease of application in Alkyd, PU, PU-Acrylic, and Epoxy bases and found acceptable.

Table 4: Evaluation of Pigment Dispersion Carmine Red
Carmine Red Initial Gloss in PU-Acrylic pastel paint Gloss retention after 2500 QUV-B exposure Initial viscosity KU Viscosity after accelerated stability test Colorant Drying time (minutes)
Reference 84.0 8.9 76 89 ~ 185
Experimental in accordance with the present invention 83.8 22.8 74 82 ~ 205
With reference sample, (commercial market sample of Pigment Dispersion Carmine Red having the viscosity in the range of 65 – 90 KU, color strength 98 – 102 %, solid 67 – 73 %), low gloss retention after 2500 h of QUV-B was observed and also there was shade fading observed after 2500 h of QUV-B.

Table 5: Influence of concentration of Solution of a copolymer with filler affinic groups of color strength
Trials Solution of a copolymer with filler affinic groups (wt.%) Color strength (%) in PU-Acrylic Darker paint Color strength (%) in PU-Acrylic Pastel paint
1 0 92.56 94.88
2 2 99.73 100.55
3 4 100.37 100.89

Concentration in the range of 2-4% worked to obtain the acceptable properties, without this Solution of a copolymer with filler affinic groups, the color strength was poor and not acceptable.

Table 6: Effect of change in stage of addition/sequence of addition of solution of a copolymer with filler affinic groups
Trials Color strength (%) when added (5%) in thinning stage Color strength (%) when added (4%) in grinding stage
Glossy paint Mat paint Glossy paint Mat paint
Solution of a copolymer with filler affinic groups 95.43 96.22 100.37 100.89

Example 3
Preparation of Pigment Dispersion Red Oxide
Resin solution (~11%), solution of a high molecular weight block copolymer [Density (g/ml) @ 20 °C: 0.985-1.000, RI @ 20 °C: 1.4770-1.4830, NVM (%) 20 min @ 150 °C: 44-46, Amine Values (mg KOH/g): 8.0-12.0, Turbidity: <30] with pigment affinic groups (~6%), and Solution of a copolymer [Density (g/ml) @ 20 °C: 1.035-1.065, RI @ 20 °C: 1.425-1.435, NVM (%) 20 min @ 150 °C: 38-42] with filler affinic groups (~4%) were weighed in a vessel fitted with the high speed disperser. This premix was kept under stirring for about 5-10 min at 6-8 m/sec to have uniform mixture. This was followed by addition of pigment PR 101 (~67%), and grinding for about 60-70 min at 18-20 m/sec, and then added rheology modifier solution of a modified urea (~1%) grinding continued for 15-20 min at 18-20 m/sec. Butyl acetate (~1.5%), and resin solution (~5.5%) were used to adjust the viscosity of the millbase to 150-350 g for dyno mill. Four dyno mill pass are required to achieve the finish of 7+. The colorant after dyno mill pass was collected and stored.

Thinning using butyl acetate (~1%), Resin solution (~2%), and solution of a high molecular weight block copolymer with pigment affinic groups (~1%) was done as and when required. The final colorant sample was checked for the viscosity, humectancy, and accelerated stability test, and found acceptable. The colorant was evaluated for coloristics, dispersion, overnight stability, weatherability, ease of application in Alkyd, PU, PU-Acrylic, and Epoxy bases and found acceptable.
Table 7: Evaluation of Red-Oxide dispersion
Red oxide Initial Gloss in PU-Acrylic pastel paint Gloss retention after 2500 QUV-B Initial viscosity KU Viscosity after accelerated stability test Colorant Drying time (minutes)
Reference 83.2 21.5 84 95 ~ 120
Experimental in accordance with the present invention 83.3 25.5 80 88 ~ 135

Reference sample, (commercial market sample of Red-Oxide dispersion having viscosity in the range of 65 – 90 KU, color strength 98 – 102 %, solid 77 – 83 %), showed a slightly inferior humectancy, gloss and shade retention after 2500 h of QUV-B exposure.

Table 8: Influence of concentration of Solution of a copolymer with filler affinic groups on color strength
Trials Solution of a copolymer with filler affinic groups (wt.%) Color strength (%) in PU-Acrylic Glossy paint Color strength (%) in PU-Acrylic Mat paint
1 0 86.79 90.34
2 2 96.25 98.45
3 4 99.58 100.26

Concentration of ~4% resulted in acceptable properties, below 2% of this Solution of a copolymer with filler affinic groups, the color strength was poor and not acceptable.

Table 9: Effect of change in stage of addition of Solution of a copolymer with filler affinic groups
Trials Color strength (%) when added (5%) in thinning stage Color strength (%) when added (4%) in grinding stage
Glossy paint Mat paint Glossy paint Mat paint
Solution of a copolymer with filler affinic groups 97.43 98.22 99.58 100.26

Addition of solution of a copolymer with filler affinic groups in grinding stage is more suitable in obtaining acceptable coloristics and dispersion, rather than when added in thinning stage as it results lower color strength and dispersion issue.

,CLAIMS:We Claim

1. A pigment dispersion/ colourant composition compatible with solvent-borne resins comprising
(a) pigment component/s including organic, inorganic pigments, extender pigments in 5-70 wt.%,
(b) 60% aldehyde resin solution including urea-aldehyde resin or formaldehyde resin having acid value ranging from 2-7 mg KOH/gm in 18-82 wt.%,
(c) high molecular weight block copolymer with pigment affinic groups in 5-16 wt. %, and having amine value of 8-12 mg KOH/g together with any one or both of the following:
(d) controlled flocculating wetting and dispersing agent including lower molecular weight unsaturated polycarboxylic acid polymer and polysiloxane copolymer with acid value: 128-168 (mg KOH/g) in 3-5 wt.%,
(e) Pigment/Filler affinic copolymer with pigment/filler affinic groups in 2-4% wt.%.

2. The pigment dispersion/ colourant composition as claimed in claim 1 wherein said composition optionally includes
(i) organic derivative of bentonite clay in 0.5-2 wt.%
(ii) Modified urea [Density (g/ml) @ 20 °C: 1.140-1.180, RI @ 20 °C: 1.517-1.533, NVM (%) 20 min @ 175 °C: 50-58, Color on Gardner Scale: < 7] in 0.4-1.6 wt.% as a rheology modifier favouring superior viscosity, humectancy, and stability.
(iii) co-acting polymeric dispersant/pigment derivative with Density (g/ml) @ 20 °C: 1.000-1.420, Appearance: Blue Powder, Moisture Content (%) 1 h @ 120 °C: < 4, pH: 2-5 (0.05- 1.0 %) was added under stirring for about 5-10 min at 6-8 m/sec.
(iv) diluent including organic solvent/s in the levels upto 75.

3. The pigment dispersion/ colourant composition as claimed in claims 1 or 2 that is compatible with said solvent borne resins including Alkyd, PU, PU-Acrylic, and Epoxy resins.

4. The pigment dispersion/ colourant composition as claimed in claims 1-3 wherein said urea-aldehyde resin is a polyaldehyde resin preferably provided in MPA and Xylol solvent in 1:1 ratio and is obtained by condensation of urea and aliphatic aldehydes,
wherein said pigments includes the pigment, PY42 (iron oxide yellow pigment), PY151 (benzimidazolone yellow), PY139 (isoindoline yellow), PR170 (naphthol red), PR122 (quinacridone red), PG7 (phthalocyanine green), PBK7 (carbon black), PO36 (benzimidazolone orange), PB15.2 (phthalocyanine blue), PB15.4 (phthalocyanine blue), PW6 (Rutile, TiO2), PR101 (iron oxide red pigment), PV23 (carbazole violet), and may also include PB15.1 (phthalocyanine blue), PB15.3 (phthalocyanine blue), PR3 (toludine red), PR112 (monoazo red), PY154 (monoazo of benzimidazolone yellow), PV19 (quinacridone violet), PY 138 (Quinophthalone yellow);

5. The pigment dispersion/ colourant composition as claimed in claims 1-4 wherein said high molecular weight block copolymer with pigment affinic groups/ dispersant comprises one or more of the compounds selected from the group consisting of (a) phosphorus ester salts of amino-containing oligomers or polymers, (b) monoesters or diesters of phosphoric acid, (c) acidic dicarboxylic monoesters, (d) polyurethane-polyamine adducts, (e) polyalkoxylated monoamines or diamines, and (f) reaction products of unsaturated fatty acids with monoamines, diamines and polyamines, amino 10 15 25 30 35 alcohols, and unsaturated 1,2-dicarboxylic acids and their anhydrides and salts thereof and reaction products with alcohols and/or amines preferably having Amine value: 10 mg KOH/g, Density (20 °C): 0.99 g/ml, Flash point: 28 °C; and suitable high molecular weight block copolymer include DISPERBYK 163 (Solution of a high molecular weight block copolymer with pigment affinic groups having amine values (mg KOH/gm): 8.0-12.0; DISPERBYK 103 (solution of polyesteric copolymers with filler affinic groups), BYK P104S (solution of a lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer with acid value (mg KOH/gm): 128-168; DISPERBYK 2155 (Block copolymer with pigment affinic groups with Amine Values (mg KOH/gm): 42-54; EFKA FA 4608 Hydroxy-functional unsaturated modified carboxylic acid with pigment-affine groups with amine values (mg KOH/gm): 80-90.

6. The pigment dispersion/ colourant composition as claimed in claim 1-5 wherein said high molecular weight block copolymer/s with pigment affinic groups/ dispersant having Density (g/ml) @ 20 °C: 1.035-1.065, RI @ 20 °C: 1.425-1.435, NVM (%) 20 min @ 150 °C: 38-42, preferably DISPERBYK-163, DISPERBYK-2150 and TEGO Dispers 670 (DISPERBYK-163, DISPERBYK-2150 and TEGO Dispers 670.

7. A process for the preparation of pigment dispersion/ colourant composition as claimed in claims 1-6 comprising the steps of mixing and grinding following components
(a) pigment component/s including organic, inorganic pigments, extender pigments in 5-70 wt.%,
(b) aldehyde resin solution including urea-aldehyde resin or formaldehyde resin having acid value ranging from 2-7mg KOH/gm in 18-82.wt.%,
(c) high molecular weight block copolymer with pigment affinic groups having amine value of 8-12 mg KOH/g in 6-10 wt. %, together with any one or both of the following:
(d) controlled flocculating wetting and dispersing agent including lower molecular weight unsaturated polycarboxylic acid polymer and polysiloxane copolymer with acid value: 128-168 (mg KOH/g) in 3-5 wt.%,
(e) Pigment/Filler affinic copolymer with pigment/filler affinic groups in 2-4 wt.%,

and obtaining therefrom said pigment dispersion/ colourant composition having compatibility with polyesters extendable to PU, PU-Acrylic, Epoxy, and Alkyds bases.

8. The process for the preparation of pigment dispersion/ colourant composition as claimed in claim 7 wherein
following pigment addition in grinding mixing stage in dyno mill, resin solution is added for flushing pigments sticking to reaction vessel that is followed by adding organic derivative of bentonite clay and said modified urea as a rheology modifier with the grinding continued to achieve desired viscosity of the millbase to 150-350 gm and finish;
thinning/ diluting with organic solvent with or without resin solution and high molecular weight block copolymer with pigment affinic groups for storing said colorant composition.

9. The process for the preparation of pigment dispersion/ colourant composition as claimed in claim 7 or 8 wherein
preparing carbon black colourant composition involves the following steps of mixing and grinding of the following components
(a). Mixing resin solution (~13%), and (b) solution of a high molecular weight block copolymer having amine value of 8-12 mg KOH/g with pigment affinic groups (~6%); and (c) Solution of a lower molecular weight unsaturated polycarboxylic acid polymer and a polysiloxane copolymer with acid value (mg KOH/g): 128-168
in a vessel fitted with the high speed disperser under stirring for about 5-10 min at 6-8 m/sec to have uniform mixture;
(d). adding synergist polymeric dispersant/pigment derivative with Density (g/ml) @ 20 °C: 1.000-1.420, Appearance: Blue Powder, Moisture Content (%) 1 h @ 120 °C: < 4, pH: 2-5 (0.8%) under stirring for about 5-10 min at 6-8 m/sec.
(e). adding pigment PB7 (~9.9%), and said resin solution (~1%) followed by grinding for about 60-70 min at 18-20 m/sec;
(f). adding further organic derivative of a bentonite clay (~1.8%) and mixed it well for about 10-15 min at 18-20 m/sec, and
(g). adding solution of a modified urea and continuing grinding for 15-20 min at 18-20 m/sec.; adjusting the viscosity of the millbase to 150-350 g for dyno mill by adding resin solution (~10 %) and Three dyno mill pass are provided the finish of 7+; and
(h). collecting and storing of the colorant.

10. The process for the preparation of pigment dispersion/ colourant composition as claimed in claim 7-9 wherein said preparing Carmine Red colourant composition involves the following steps of mixing and grinding of following components
a. Resin solution (~34%%),
b. Solution of a high molecular weight block copolymer [Density (g/ml) @ 20 °C: 0.985-1.000, RI @ 20 °C: 1.4770-1.4830, NVM (%) 20 min @ 150 °C: 44-46, Amine Values (mg KOHg): 8.0-12.0, Turbidity: <30] with pigment affinic groups (~8%), and c. solution of a copolymer [Density (g/ml) @ 20 °C: 1.035-1.065, RI @ 20 °C: 1.425-1.435, NVM (%) 20 min @ 150 °C: 38-42] with filler affinic groups (~2%)
in a vessel fitted with the high speed disperser for 5-10 min at 6-8 m/sec to have uniform mixture.
ii) adding pigment PR 170 (~25%) followed by grinding for 10-15 min at 18-20 m/sec,
iii) adding organic derivative of bentonite clay (~0.75%) with continuation of grinding for 40-50 min at 18-20 m/sec.
iv) adjusting the viscosity of the millbase to 80-200 g for dyno mill by adding Butyl acetate (~1 %), and resin solution (~16%) and four dyno mill pass are required to provide for the finish of 7+.
v) collecting and storing the colorant after dyno mill pass;
optionally followed by diluting/ thinning involving Xylol (~1%), butyl acetate (~1%), Resin solution (~11.25%).

11. The process for the preparation of pigment dispersion/ colourant composition as claimed in claim 7-10 wherein said preparing Red-Oxide colourant composition involves the following steps of mixing and grinding of following components
a. Resin solution (~11%),
b. Solution of a high molecular weight block copolymer [Density (g/ml) @ 20 °C: 0.985-1.000, RI @ 20 °C: 1.4770-1.4830, NVM (%) 20 min @ 150 °C: 44-46, Amine Values (mg KOHg): 8.0-12.0, Turbidity: <30] with pigment affinic groups (~6%), and c. solution of a copolymer [Density (g/ml) @ 20 °C: 1.035-1.065, RI @ 20 °C: 1.425-1.435, NVM (%) 20 min @ 150 °C: 38-42] with filler affinic groups (~4%)
in a vessel fitted with the high speed disperser for 5-10 min at 6-8 m/sec to have uniform mixture.
ii) adding pigment PR 101 (~67%) followed by grinding for 60-70 min at 18-20 m/sec,
iii) adding rheology modifier solution of a modified urea (~1%) with continuation of grinding for 15-20 min at 18-20 m/sec.
iv) adjusting the viscosity of the millbase to 150-350 g for dyno mill by adding Butyl acetate (~1.5%), and resin solution (~5.5%) and four dyno mill pass are required to provide for the finish of 7+.
v) collecting and storing the colorant after dyno mill pass,
optionally followed by diluting/ thinning involving butyl acetate (~1%), Resin solution (~2%), and solution of a high molecular weight block copolymer with pigment affinic groups (~1%).

Dated this the 18th day of October, 2021 Anjan Sen
Of Anjan Sen and Associates
(Applicants Agent)
IN/PA-199