FORM 2
THE PATENT ACT 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
TITLE OF THE INVENTION
DESIGN OF IMPELLER ASSISTED CIRCULATION MILLING FOR FINER
DISPERSION
APPLICANT
REGISTRAR, NORTH MAHARASHTRA UNIVERSITY., JALGAON

DESIGN OF IMPELLER ASSISTED CIRCULATION MILLING FOR FINER DISPERSION
The following manuscript particularly elaborates the invention and manner in which it is to be performed.
FIELD OF THE INVENTION
The present invention describes a simple methodology for efficient and enhanced pigment dispersion and design and fabrication of Impeller Assisted Circulation Mill through combinations of design features of ball mill and bead mill.
BACKGROUND OF THE INVENTION
Dispersion machinery in paint manufacturing is designed to generate and transmit energy from dispersion aid to pigment particles. On the other hand, the efficiency of dispersion operation is significantly dependent upon the effectiveness of the transfer of energy from the dispersion tools/dispersion charges to the oversized pigment particles, as a result of the presence of the adhesion and cohesion within the dispersion system. Historically, to obtain homogeneous pigment wetting, deagglomeration and dispersion, kneaders, rotor and stator mills, and roller mills came first. These were followed by ball mills, tank mills, attritors, and (open) sand (bead) mills.
OBJECTS OF THE INVENTION
The dispersion of pigment in polymeric binder in presence of additives and solvents is one of the most expensive steps in manufacture of paint. A method of reducing the processing cost or obtaining better value from the pigments will thus produce an immediate economic advantage' With the rising costs of both pigments and energy, it makes economic sense to ensure that both are used efficiently. It is desirable to achieve maximum tinctorial strength per kilo of pigment and to use minimum energy in .achieving this effect. At the same time, it is essential to develop the process which can facilitate dispersion of difficult pigments or allows processing of mixed size pigments. Accordingly,, the main object of this invention was to develop a simple processing aid by incorporating both grinding and dispersion mechanisms to obtain optimum dispersion condition with minimum operating investment.
SUMMARY OF THE INVENTION
For dispersing larger agglomerates, the interaction forces between the particles must be overcome using a dispersing machine. The efficient transmission of energy from dispersion equipment to the pigment particle is the key to factor in obtaining cost effective pigment manufacturing. Specific dispersion equipment works on certain mechanism. Ball mill works on cascading mechanism, and

can hammer even difficult pigments. But it requires long processing time, sometimes as high 48-72 hrs. Bead mill works on attrition mechanism and requires short processing time, sometimes as low as 2 hrs. But it cannot hammer difficult to process pigments or multi size pigment mixture.
To squeeze in synergistic combinations of merits of ball mill and bead mill in single equipment, the present invention provides a design and fabrication of Impeller Assisted Circulation Mill. Extensive dispersion trials and detail testing of paints processed were conducted to prove the viability of design of Impeller Assisted Circulation Mill.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, amalgamations of bail mill and bead mill is performed in a simple, novel Impeller Assisted Circulation Mill using circular disc and cross shaped stationary impellers. Mill base calculations and let down additions were worked out successfully for ball mill, bead mill and Impeller Assisted Circulation Mill for green glossy paint, yellow chrome glossy paint, white flat paint, white undercoat paint and white undercoat base yellow tinter and to obtain formulations that met the requirements of finer dispersion at the lowest material cost and to verify the feasibility of new design.
In one form of the invention, the process for preparation of green glossy paint involved manufacturing of paint in to bead mill and Impeller Assisted Circulation Mill.
In one more form of the present invention, preparation of yellow chrome glossy paint formulation was carried out in bead mill and Impeller Assisted Circulation Mill.
In another form of present invention white flat paint formulations were processed in ball mill and Impeller assisted circulation mill.
In another form of present invention white undercoat paint formulations were processed in ball mill and Impeller assisted circulation mill.
In yet another form of present invention, mill base and Letdown Compositions were prepared for white undercoat paint and processed for dispersion in ball mill and Impeller assisted circulation mill.
In another form of present invention white undercoat base yellow tinter formulations were processed in ball mill and Impeller assisted circulation mill.
In all the embodiments, synthesized paints were characterized by color matching spectral analysis for color strengths and particle size was monitored using Hegman Gauge.

In some embodiments, the characterizations of prepared paints include color matching spectral analysis including color strengths and reflectance verses wavelength analysis and Hegman Gauge and scanning electron microscopy (SEM) for particle size.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 relates a design of rotating Impeller Assisted Circulation Mill constituting a Circular disc impeller (2 a) mounted on a stationary shaft (3), nuts and bolts (4) for fitting arrangement, steel balls as the grinding media (5), paint formulations as dispersing mixture (6) and motor (7) for
rotating the mill.
Fig. 2 relates the similar design as Figl showing a cross shaped impeller.
Fig.3 relates circular disc impeller
Fig.4 relates cross shaped impeller.
Fig.5 relates colour matching spectral analysis of green glossy paint.
Fig.6 relates SEM analysis of green glossy paint prepared in bead mill.
Fig.7 relates SEM analysis of green glossy paint prepared in Impeller Assisted Circulation Mill.
Fig.8 relates colour matching spectral analysis of yellow chrome glossy paint.
Fig.9 relates SEM analysis of yellow chrome glossy paint prepared in bead mill.
Fig. 10 relates SEM analysis of yellow chrome glossy paint prepared in Impeller Assisted
Circulation Mill.
Fig.l 1 relates colour matching spectral analysis of white flat paint.
Fig. 12 relates reflectance Vs wavelength curve of white flat paint in bead mill.
Fig. 13 relates reflectance Vs wavelength curve of white flat paint in Impeller Assisted Circulation
Mill.
Fig.14 relates colour matching spectral analysis of white undercoat paint in bead mill.
Fig. 15 relates colour matching spectral analysis of white undercoat paint based yellow tinter in ball mill.
Fig. 16 relates reflectance Vs wavelength curve of white undercoat paint based yellow tinter in ball mill.
Fig. 17 relates reflectance vs wavelength curve of white undercoat paint based yellow tinter in Impeller Assisted Circulation Mill.

DETAILED DESCRIPTION WITH RESPECT TO EXAMPLES AND DRAWING
According to figure 1, formulation of paint (6) is fed to the mill initially. The mill base is grinded and mixed by means of a teflon based agitator in bead mill at 2840 rpm, by means of grinding media of 3 to 4 mm size at 170 rpm in ball mill and by means of stationery rotor (3) in Impeller Assisted circulation mill at 90 rpm. The specific mill is allowed to run for at least for 2 hrs and their particle size is checked using Hegman Gauge frequently. After 5 to 6 hrs, the particle size is again checked and if it is 7+ then let down composition is added and the mill is run for 30 minutes. The synthesized paints are characterized by color matching spectral analysis and scanning electron microscopy (SEM). In color matching analysis 'L values' indicate better lightness developed, 'negative a; values indicate better greener shade and b values reveal better yellowness. The SEM analysis is performed on samples drawn from mill at regular interval of time.
EXAMPLE 1
The formulation of green glossy paint was prepared according to formulation given in Table I and charged in to bead mill and Impeller Assisted Circulation Mill. The mill base was grinded with attrition mechanism and mixed by means of teflon based agitator at 2840 rpm in bead mill and by means of stationery rotor, steel balls as a grinding media in Impeller Assisted Circulation Mill at 90 rpm respectively.
Table 1. Overall formulation of Green Glossy Paint

SR.NO. Ingredients Weight in %
1 Phalocyanine Blue 1.0
2 Hansa yellow G 10.0
J Ferrite yellow 3.5
4 Lond oil alkyd(70% solid) 59.9
5 Mineral turpentine oil 20.6
6 Dipentene 3.0
7 Methyl ethyl ketoxime 0.1
8 9 Cobalt octoate 0.4

Calcium octoate 1.5
Total 100
Solids by v olume = 50.3, Sp. gravity = 0.97, % pigment volume concen Oration (PVC) = 25.5
The synthesized green glossy paint was characterized by colour matching spectral analysis and given in Fig. 5. The color strength of pigment dispersed in Impeller Assisted Circulation Mill was better than thai dispersed in bead mill. SEM results shown in Fig. 6 and Fig. 7 revealed that in Impeller Assisted Circulation Mill dispersion of particles was more enhanced than in bead mill.

EXAMPLE 2
The yellow chrome glossy paint was prepared with formulation given in Table 2 and processed and characterized as in Example 1. Results of characterization are depicted as in fig. 8, 9, and 10.
Table 2. Formulation of yellow chrome glossy paint

SR.NO. Ingredients Weight in %
1 Yellow chrome 15.2
2 Lond oil alkyd(70% solid) 59.4
n j Mineral turpentine oil (MTO) 20.4
4 Dipentene 3.0
5 Methyl ethyl ketoxime 0.1
6 Cobalt octoate 0.4
7 Calcium octoate 1.5
Total 100
Solids by' volume = 46.7, Sp. gravity = 0.98, % PVC-19.7
EXAMPLE- 3
White flat paint with overall formulation was obtained as in Table 3 were processed and characterized. The mill base was grinded and mixed by means of cascading mechanism using grinding media of 3 to 4 mm size at 170 rpm in ball mill and by means of stationery rotor and steel balls as a grinding media with Impeller Assisted Circulation Mill at 90 rpm. respectively.
Table 3. Overall Formulation of White Flat Paint

SR. NO. Ingredients Weight in
% Sp.Gr. Vol.in Lit.
1 Ti02 42.21 4.0 10.55
2 CaC03 3.84 2.7 1.42
Talc 7.67 2.75 2.79
4 Long oil alkyd(70% solid) 26.328 0.9 9.636
5 MTO 7.67 0.79 9.70
6 Soya Lecithin 11.89 0.79 14.54
7 Co-Drier 0.061 - 0.061
8 Pb-Drier 0.231 - 0.231
9 Dipentene 0.0759 1 0.0759
Total 100 62.188
% NV1 VI = 66 Wt/lit. = 1.4 2 °/ o PVC = 6 1.24
The synthesized white flat paint was characterized by colour matching spectral analysis and shown in fig. 11,12 and 13. In color matching analysis, reflectance Vs wavelength curves as figure 12 and

13 revealed that by using impeller assisted circulation mill at 560 nm wavelength the reflectance value (78.327) is greater than the reflectance value (76.067) in ball mill.
EXAMPLE 4
White undercoat paint with overall formulation as in Table 4 was prepared and characterized as in Example 3. Mill base and let down formulations for ball mill and Impeller Assisted Circulation Mill given in Table 5 and Table 6.
Table 4 Overall Formulation of White undercoat paint

SR. NO. Ingredients Weight in% Sp.Gr. Vol.in Lit.
1 Tio2 20.3 4.0 5.075
2 Micronized Barytes 33.9 4.5 7.53
J Talc 10.5 2.75 3.81
4 Long oil alkyd(70% solid) 21.4 0.9 23.78
5 MTO 17.0 2.75 21.51
6 Soya Lecithin 2.5 1 2.5
7 Co-Drier 0.3 1 0.1
8 Methyl Ethyl Ketoxime 0.1 1 0.1
Total 100 64.60
%NVM = 77.05 Wt/lit. - 1.31 %PVC ; = 58.82
Table 5 Mill base and Letdown Composition of White undercoat paint for dispersion in Ball Mill

SR. NO. Ingredients Total Mill Base Let Down
1 Tio2 0.2655 0.2655 -
2 Micronised Barytes 0.442 0.442 -
Talc 0.1371 0.1371 -
4 Long oil alkyd(70% solid) 0.3992 0.1620 0.117
5 MTO 0.3171 0.1287 0.0409
6 Soya Lecithin 0.04663 0.0189 0.014
7 Co-Drier 0.005596 0.00227 0.05369
8 Methyl Ethyl Ketoxime 0.001865 0.00075 0.00055

Table 6 Mill base and Letdown Composition of White undercoat paint for dispersion in Impeller Assisted Circulation Mill

SR. NO. Ingredients Total Mill Base Let Down
1 Ti02 0.1513 0.1513 -
2 Micronised Barytes 0.2527 0.2527 -
Talc 0.07827 0.07827 -
4 Long oil alkyd(70% solid) 0.2278 0.1620 0.0658
5 MTO 0.1810 0.1287 0.0523

Soya Lecithin 0.02662 0.0189 0.00772
7 Co-Drier 0.003194 0.00227 0.0000924
8 Methyl Ethyl Ketoxime 0.001064 0.00075 0.000314
Colour matching spectral analysis are shown in Fig-14.
EXAMPLE 5
White alkyd undercoat paint base with yellow tinter was prepared in ball mill as in Example 3 with Alkyd Resin: Yellow pigment: Mineral turpentine oil ratio of 35:10:55.
The synthesized white alkyd undercoat paint Base with yellow tinter was characterized by colour matching spectral analysis as per 15, 16, and 17. Reflectance vs wavelength curves showed that in fig. 16 and 17 shows that by using Impeller Assisted Circulation Mill at 580 nm wavelength the reflectance value (72.650) is better than the reflectance value (72.300) in ball mill.

DEFINITIONS
"Paint", as the term is used herein, encompasses any raw liquefiable mixture that can be transformed into a mastic composition. In certain embodiments, the paint is a fluid mass. The term paint includes, but is not limited to. solutions, emulsions dispersions or mixtures.
"Pigments", as the term is used herein, encompasses any granular solids incorporated into the paint to contribute colour, toughness or simply to reduce the cost of the paint. In certain embodiments, the pigment is a solid powder. The term pigments include, but are not limited to, strong or weakly intermolecular forces, organic as well as inorganic materials.
"Binder." as the term is used herein, encompasses the actual film forming component of paint. In
certain embodiments, the binder is a sticky resinous material. The term binder includes, but is not limited to, drying, or curing mechanism as well as polymeric materials.
"Solvent", as the term is used herein, encompasses to adjust the viscosity of the paint. In certain embodiments, the solvents are a volatile liquid. The term solvent includes, but is not limited to, part of the paint film as well as control flow and application properties.
"Dispersion, as the term is used herein, encompasses any converting dry pigments into pigment suspension. In certain embodiments, the dispersion is a stabilized mechanism. The term dispersion includes cost effective paint coatings, completely deflocculated, improved compatibility to the process.
The term mill base is a stirring the dry pigment into the vehicle and eliminating lump obtaining stabilized pigments system with polymeric binder.
The term let down is a combining the pigment dispersion with the balance of the ingredients to
make a coating.

We claim,
1. A new design for efficiently dispersing pigment in polymeric binder with minimum operating
investment, said design comprising
a. Rotating mill
b. Circular disc and cross shaped impeller
c. A stationary shaft
d. Nuts and bolts for fitting arrangement
e. Steel balls as the grinding media
f. Paint formulations as dispersing mixture
g. Motor for rotating the mill.
2. A design as in claim 1 for stabilized dispersion of pigment in polymeric binder for preparation of green glossy paint with minimum investment cost.
3. A design as in claim 1 for stabilized dispersion of pigment in polymeric binder for preparation of yellow chrome glossy paint with minimum investment cost.
4. A design as in claim 1 for stabilized dispersion of pigment in polymeric binder for preparation of white flat paint with minimum investment cost.
5. A design as in claim 1 for stabilized dispersion of pigment in polymeric binder for preparation of white undercoat paint with minimum investment cost.
6. A design as in claim 1 for stabilized dispersion of pigment in polymeric binder for preparation of white undercoat base yellow tinter with minimum investment cost.
7. A impeller assisted circulation mill for highly dispersed pigment in polymeric binder
substantially as described herein and illustrated with the help of examples and drawings.