High Volume Polymeric Dispersant technology for optimized pigment dispersion. Johan Bieleman

Transcription

1 High Volume Polymeric Dispersant technology for optimized pigment dispersion Johan Bieleman 1

2 Summery Recently a new class of polymeric dispersing agents, characterised as High Molar Volume Polymers, has been commercialised. The effect of these additives is demonstrated on the dispersion of carbon blacks and various organic pigments, dispersed in solventborne as well as in waterborne systems. Main application area of he polymers is in industrial and automotive paints, as well as in in-plant tinting systems. The testresults confirm improvements on ease of dispersion as well as superior film performances, notably tinting strength, high masstone jetness, gloss and stability. 2

3 Outline Introduction Wetting and Dispersion process High Molar Volume dispersant technology CBk Millbase properties Carbon Black Jetness Coating performance improvements Effect of Synergists Summary 3

4 Wetting & Dispersion process Pigment dispersion process: Pigment wetting De-agglomeration Stabilisation, minimizing re-flocculation risk Electrostatic repulsion: Charged particles Dominant stabilisation in waterborne paints

5 Wetting & Dispersion process Entropical stabilisation: Sterical layer, keeping particles apart Main stabilisation in apolar systems Adsorbed Pat-Add dispersant/ stabiliser Dispersant requirements: Containing pigment affinic groups providing strong adsorption on pigment surface. Resin/solvent compatible chains directed into the surrounding vehicle. Pat-Add DA 934 (industrial) / -DA 815 (co-grinding) / -DA 707 (alkyd paints)

6 Wetting & Dispersion: Monomeric vs. Polymeric Dispersant Low Mw dispersant High Mw polymeric dispersant backbone Low Mw.: Single anchoring Open structure Fast adsorption/ desorption Poor long-term stabilization Example: lecithin, APE pigment High Mw.: Multiple anchoring Dense cloud stabilizing dispersant Slower adsorption Limited risk of desorption Excellent stabilisation Pat-Add DA 934: for SB Pat-Add DA 932: SB Acr. Pat-Add DA 440: for WB 6

7 attraction repulsion Wetting & Dispersion process: Stabilisation Stabilisation: DLVO Theory interaction Attractive/ Repulsive forces Repulsive, electrostatic and/ or steric V+ V - ΔD a : Distance at which particles agglomerate Δd: decreasing distance between 2 particles Vt=Va+Vr s (sum forces) Va=vanderWaals attraction Vr=Repulsion forces Reference: Additives for Caotings, Wiley-VCH, Ed. Johan Bieleman 7

8 Wetting & Dispersion process Conventional polymeric dispersants: low volume per mass ΔDa: distance at which particles agglomerate (Relatively) low layer thickness of the adsorbed layer cannot prevent attractive forces to dominate stabilizing forces: agglomeration adsorption layer cannot prevent agglomeration 8

9 Patcham unique High Molar Volume (HMV) Polymer technology for optimal stabilisation Specific and molar volume Molar volume differences related to group contributions Determined by Mass and Packaging of matter Molecular mass is sum of mass composing atoms, packing volume is not Packing is influenced by electronic structure of the atoms in the polymer [group contribution CH2CH2 vs. Aryl-gr.: +24% volume /equiv. mass] Type of bonding Structural and spatial variation Technology used in: Pat-Add DA 934/ -932/ -939/ -501/ -440/

10 High Molar Volume Technology: UNIQUE TECHNOLOGY for polymeric dispersants ΔDa Higher volume contributes to thicker adsorbed layer, preventing attractive forces to dominate stabilizing forces: stable dispersion! Better transparency using Pat-Add DA Thickness adsorption layer preventing agglomeration 10

11 µm CBk Millbase properties: Shorter milling time and FOG FOG PAT ADD DA 934 REFERENCE B 1 HR HRS HRS HRS K PU DG OF CARBON BLACK FW 200 FOG READING USING HEGMAN GAUGE 20 New HMV based dispersant Pat-Add DA 934 outperforms in: (50%) reduction milling time Lowest particle size HR 2 HRS 3HRS 4 HRS TIME PAT ADD DA 934 REFERENCE B REF: R_

12 VISCOSITY, CPS CBk Millbase properties: Lower Viscosity Viscosity of the millbase PAT ADD DA 934 REFERENCE B 1 HR HRS HRS HRS K PU DG OF CARBON BLACK FW 200 VISCOSITY PROFILE OF MILLBASE DURING GRINDING PHASE New HMV based dispersant Pat-Add DA 934 outperforms in lowering mill-base viscosity, optimal energy transfer HR 2 HRS 3 HRS 4 HRS TIME PAT ADD DA 934 REFERENCE B REF: R_

13 CBk Millbase properties: Improved Flow Dispersion of HCC Carbon Black: FW 200 New HMV based dispersant Pat-Add DA 934 outperforms in: Newtonian flow Lower mill-base viscosity Reduction milling time Lower viscosity, best flow, using Pat-Add DA

14 Carbon Black Jetness: Visual comparison New HMV based dispersant Pat-Add DA 932 outperforms in higher jetness and stability 14

15 Mc Values Ranking Higher Carbon Black Jetness RMPC OF RAVEN 5000 CARBON BLACK IN 2K PU ACRYLIC SYSTEM Properties PAT ADD DA 932 Reference B MASS TONE Mc (Jetness) ,5 New HMV based dispersant Pat-Add DA 932 outperforms in: 7 Best jetness index Excellent match between visual impression jetness and Mc data 6,5 6 Mc: Mc is the Color Dependent Black Value and was developed by K. Lippok-Lohmer (Farbe + Lack, (1986), vol. 92, p. 1024). It is defined by the equation Mc = 100[log(Xn/X) - log (Zn/Z) + log (Yn/Y)], where X, Y, and Z are measured tristimulus values. The Mc value correlates well with the human perception of increased jetness. The higher the Mc value, the higher the jettness of the masstone. 5,5 5 PAT ADD DA 932 Reference B REF: R_

16 Coating performance improvement: Higher gloss level GLOSS (pour-out) PAT ADD DA 934 REFERENCE B New HMV based dispersant outperforms in: Higher gloss Transparency 16

17 Coating performance improvement: Better transparency DEGREE OF TRANSPARENCY PAT ADD DA 934 REFERENCE B New HMV based dispersant outperforms in Best transparency 17

18 High Molar Volume Dispersant unique features Pat-Add DA 900 HMV polymeric dispersants Robust stabilisation, resulting in: - Optimal milling - Higher jetness - Transparency Pat-Add DA 934: alkyd, PE, EP resins Pat-Add DA 932: acrylic, TPA resins pigment High volume entropical stabilisation Multiple anchoring feature Used alone or with synergists 18

19 Synergists used with HMV Dispersants Anchoring intermediate for poly-nuclear pigment surfaces Strong connection to pigment by multiple anchoring Designed for best interaction with Pat-Add DA 900 series Lower millbase viscosities, higher pigment loadings,+ ~ 50% High transparency Pat-Add DA 2650 for CBk and PB. Pat-Add DA 2672 for Ye, Rd Synergist DA DA 2672 DA 934/ DA

20 HMV Dispersant & Synergist for higher CBk Loading New HMV dispersant Pat-Add DA 934, with synergist Pat-Ad DA 2650, for optimal: Shelf stability Newtonian flow Transparency - OEM - RMPC - inks high loaded RMPC, 10% HCC CBk, 3 months storage HMV-dispersant -DA 934 Synergist Pat-Add DA

21 Summary Patcham HMV Dispersant Technology: - New and Sustainable technology - Higher Jetness - Increased Gloss level - Improved Transparency Pat-Add DA 934: key polymeric dispersant Pat-Add DA 932: first choice for acrylics, incl. TPA Pat-Add DA 2650: synergist 21

22 Thank you Please contact us/- your local Patcham representative for samples and information 22