Slide 1: Surface Modified Color Pigments
Surface Modified Color Pigments Yuan Yu and Friedrich von GottbergDate
Slide 2: Outline
2 Outline • Technology background – Diazonium Reaction • Commercial products • Extension to color pigments – Physical properties – Stability testing – Print properties • Surface modification versatility • Key benefits • Summary
Slide 3: Diazonium Formation
3 Diazonium Formation US Patent 5,554,739 5,922,118
Slide 4: Surface Modification Reaction
4 Surface Modification Reaction R = COOH = SO3H = Polymer
Slide 5: Example Commercial Products
5 Example Commercial Products Cab-O-Jet® 200 Cab-O-Jet® 300 Frequency Na+ - Na+ - 20 SO3 CO2 Na+ - Na+ - 18 SO3 SO3H CO2 CO2H 16 Na+ Na+ Na+ SO3- SO3- H2OC CO2- 14 SO3- SO3- CO2- CO2- 12 Na+ Na+ Na+ Na+ 10 8 6 Print Performance 4 COOH SO3H 2 Optical Density 1.5 1.4 0 .0723 Microns .3437 Waterfastnes
Slide 6: Extension to Color Pigments - Questions
6 Extension to Color Pigments - Questions • Will diazonium chemistry work on organic color pigments • By modifying surface with solubilizing groups will one create dye • Will surface modification alter color properties and lightfastness • Can we create a stable color pigment dispersion • Will the ap
Slide 7: Extension to Color Pigments
7 Extension to Color Pigments IJX266 — Quinacridone IJX253 — Cu Phthalocyanine IJX273 — Monoazo
Slide 8: Physical Properties of Dispersions
8 Physical Properties of Dispersions Modified pigments with surface sodium sulfonate groups Physical Properties IJX™ 253C IJX™ 266D IJX™ 273B Color Cyan Magenta Yellow Pigment Type PB 15:4 PR 122 PY 74 Pigment Loading 11.7 % 10.4 % 9.2 % Viscosity1 2.1 cP 2.4 cP 2 .0 cP Surface Tension2 70.3 dynes/c
Slide 9: Dispersion Purification
9 Dispersion Purification • Essential to remove reaction byproducts, excess salts and unreacted starting materials • Purification is done using dialysis against DI water – Soluble impurities pass through membrane leaving surface modified pigment and its counterion • Dialysis permeate does not contai
Slide 10: Stability Testing
10 Stability Testing • Testing Conditions – Pigment dispersion at 10% – Generic ink with 5% pigment and 10% 2-pyrrolidone – Four-month aging 25°C and 70°C
Slide 11: Four Month Aging test of IJX 253 (PB 15:4)
11 Four Month Aging test of IJX™ 253 (PB 15:4) Mean volume Number of particles PB 15:4 particle size (nm)1 > 0.5 µm2 INITIAL AGED INITIAL AGED 25ºC: Pigment 92 92 2.7E+8 1.1E+8 Generic Ink 89 90 2.4E+8 1.6E+8 70ºC: Pigment 92 91 2.7E+8 1.8E+8 Generic Ink 89 90 2.4E+8 1.6E+9 1Mean volume particle siz
Slide 12: Four Month Aging test of IJX 266 (PR 122)
12 Four Month Aging test of IJX™ 266 (PR 122) Mean volume Number of particles PR 122 particle size (nm)1 > 0.5 µm2 INITIAL AGED INITIAL AGED 25ºC: Pigment 110 106 3.8E+8 1.4E+8 Generic Ink 105 106 4.0E+8 1.4E+8 70ºC: Pigment 110 94 3.8E+8 1.5E +8 Generic Ink 105 100 4.0E+8 1.3E+8 1Mean volume partic
Slide 13: Four Month Aging test of IJX 273 (PY 74)
13 Four Month Aging test of IJX™ 273 (PY 74) Mean volume Number of particles PY 74 particle size (nm)1 > 0.5 µm2 INITIAL AGED INITIAL AGED 25ºC: Pigment 135 135 1.6E+8 5.8E+7 Generic Ink 125 126 1.7E+8 1.3E+8 70ºC: Pigment 135 130 1.6E+8 1.3E +8 Generic Ink 125 105 1.7E+8 5.0E+7 1Mean volume particl
Slide 14: Impact of Surface Modification on Color
14 Impact of Surface Modification on Color • UV-VIS absorbance – Comparison made at same pigment loading and same particle size – Compared surface modified to conventionally dispersed pigment – Compared nature of attached group - carboxylate versus sulfonate • Result – Absorbance curves can be super
Slide 15: UV-VIS Comparison (PB15:4)
15 UV-VIS Comparison (PB15:4) 1.2 1 Absorbance 0.8 0.6 0.4 0.2 0 350 450 550 650 750 Wavelength (nm) Surface Modified Conventional Dispersion
Slide 16: Color Properties on Set of Plain Papers (PR122)
16 Color Properties on Set of Plain Papers (PR122) Conventional Surface Modified Pigments Sulfonate Carboxylate Quat High Low L* 57 55 56 53 54 a* 41 46 47 48 49 b* -13 -12 -9 -13 -13 Chroma 43 47 48 50 51
Slide 17: Printing Performance
17 Printing Performance IJX™ Pigment L*1 a* b* OD WF2 LF3 253 PB 15:4 52 -18 -37 1.0 24 hrs 90% 266 PR 122 56 47 -9 1.0 5 min 93% 273 PY 74 89 -6 84 1.2 5 min <50% 1L*a*b* readings determined by a Hunter LabScan II 2WF: Waterfastness is time taken by print to dry sufficiently that the runoff of 2.5
Slide 18: Surface Modified Color Pigments - Conclusions
18 Surface Modified Color Pigments • Conclusions – Particle size of all pigment dispersions and inks grew less than 10% after aging – Number of particles greater than 0.5 µm did not change after aging – Color and light stability of pigment seem unaffected by surface modification – No dye appears to
Slide 19: Zeta Potential
19 Zeta Potential + Cationic 20 Zeta Potential (mV) Anionic -18 -25 -35 - High Treatment Level Low
Slide 20: Ion Exchange
20 Ion Exchange Carboxylate sodium salt modified PB15:4 Na+ NH4+ (ppm) (ppm) Waterfastness Before Ion Exchange 6000 — 1 hour After NH4+ Exchange 90 4800 10 mins
Slide 21: Benefits of Surface Modification
21 Benefits of Surface Modification • Technology – Ability to tailor surface properties • Physical Properties of Pigment Dispersions – High surface tension (~ 70 dynes/cm) – Low viscosity (< 2.5 cP at 10% solids) – Superior colloidal stability – High purity (material covalently attached) • Ink – For
Slide 22: Formulation Flexibility
22 Formulation Flexibility Conventional Surface Modified Pigment Pigment Stabilizer Pigment Stabilizer Dispersion Ink Pigment Stabilizer Pigment Stabilizer Ink Ink
Slide 23: Surface Modification Versatility
23 Surface Modification Versatility Treatment Type Counterion Type • Ionic (+ and -) • Negative/Positive • Non-ionic • Organic/inorganic • Multiple/additional • Small molecules/polymers treatments • Polymers Pigment Type Treatment Level Black adjusted for desired Cyan properties Magenta Yellow
Slide 24: Broad Applicability to Pigment Classes
24 Broad Applicability to Pigment Classes • Demonstrated surface modification of – Metal phthalocyanines – Quinacridone – Naphthol-AS – Mono-azo – Di-azo – Diketopyrrolo-pyrrole – Carbon Black • Not all organic pigments can be treated
Slide 25: Summary
25 Summary • Cabot surface modification technology extended to organic color pigments – Dispersing group attached to pigment surface – Provides unique and valuable dispersion properties • Ideally suited for Digital Imaging Applications www.cabot-corp.com inkjet@cabot-corp.com