Calcined Kaolin 煅烧高岭土

* Opacilite has lower SG (internal voids)
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Comparison of Imerys Calcined Kaolins
Dry Film properties (65% PVC)
Extender Dry Film Properties Contrast Ratio @ 20m2/l Colour L* Gloss (%/85o) % Stain Resistance (Gilsonite) Mud Crack Resistance (μm) BS Scrub Resistance (weight loss @ 200 cycles mg/cm2) ASTM Scrub Resistance (cycles)
95
93
Polestar 200P Opacilite Polestar 400
91
89
87 12 10 8 6 4
Calcined Kaolin Level (wt%)
40% less Opacilite & 50% PoleStar 400 to match opacity
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Reformulation of One Coat Matt Emulsion (74% PVC) Reformulating with Opacilite
Extender d50 (μm) Viscosity (poise) Brookfield 1 rpm (0.3 sec-1) Brookfield 100 rpm (30 sec-1) Rotothinner (150 sec-1) Cone & Plate (104 sec-1) Specific Gravity Polestar 200P 2 670.0 45.0 9.7 0.8 1.394 Opacilite 1.6 890.0 54.0 11.5 1.0 1.370* Polestar 400 0.6 860.0 51.0 11.1 1.0 1.394
Calcined Kaolin
Dehydroxylated Aluminum Silicate
Hydrous Kaolin SEM
Platy kaolin particles before calcination
A Thermal History of Calcined Clay
Heatflow by DSC, weight loss by TGA
Pigment (% by weight) Calcined kaolin CaCO3 (5μm) Dry Film Properties 2 Contrast Ratio at 20m /l Colour L* b* o Gloss (%/85 ) Stain Resistance (%) BS Scrub Resistance, wt loss after 2 40 cycles (mg/cm ) ASTM Scrub Resistance (cycles) Mud Crack resistance (μm) Specific Gravity PoleStar 200P 12.0 28.0 90.2 97.0 2.10 2.2 72 1.15 205 >1500 1.478 Opacilite 7.0 33.0 90.2 96.7 2.00 2.4 74 1.10 190 >1500 1.464 PoleStar 400 6.0 34.0 90.2 97.0 2.00 2.5 75 1.30 160 975 1.480
Comparison of Imerys Calcined Kaolins
High quality matt emulsion (65% PVC)
% by Weight
Ti-Pure R-706 *Calcined Kaolin Ropaque Ultra CaCO3 (d50=5μm) Tamol 731A/AMP95 (3:1) 2% Natrosol 250 MBR Proxel GXL Foamaster NXZ Texanol/PPG (1.2:1) Ucar Latex 367 Acrysol RM8 Water Total
Surface Area (m2/g)
Imerys Calcined Kaolin Products
Comparison of typical properties
Product
Brightness Mean Size Hegman μm (ISO) (d50) μm 90 92 87 2.0 0.6 1.6 30
• opacity by dry hiding
• Typically 2 to 5 different extenders • Typical properties – high opacity, high whiteness – good scrub & mud crack resistance – low gloss
Structured Calcined Kaolins
Effect on paint performance Medium Structure
Low void volume Large voids Regular particle shape Low Oil Absorption Coarse particle size Opacity
• Smaller aggregate (~0.7μm) – smaller primary particles – very irregular particle shape • Large air voids (~0.4μm) • High void volume (~1.2 ml/g) • High oil absorption (75-90 g oil /100g)
15.0 12.0 5.0 13.0 0.4 17.5 0.1 0.3 2.2 17.5 0.6 16.4 100.0
*PoleStar 200P, Opacilite & PoleStar 400
Comparison of Imerys Calcined Kaolins
Liquid paint properties (65% PVC)
PoleStar 200P SEM
Medium particle size, medium structure
PoleStar 400 SEM
Fine particle size, high structure
Structured Calcined Kaolins
Physical properties
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Function
TiO2 pigment (DuPont) Functional extender (Imerys) Opaque polymer (Rohm & Haas) Extender Dispersants (R&H/DOW) Thickener solution/water (Hercules) Biocide (Arch Biocides) Defoamer (Cognis) Coalescing solvents (Eastman/DOW) Vinyl acrylic latex (DOW) Thickener (Rohm & Haas)
Structured Calcined Kaolins
Comparison of Imerys products
16
High
Opacilite Structure Medium
PoleStar 400
12
8
Low
PoleStar 200P
4 2 1.6 1.2 0.8 0.4
Mean Particle Size (µm)
• Medium Structure • High Structure
• Large aggregate (1.5 - 2.0μm) – larger primary particles – irregular particle shape • Large air voids (~1.0μm) • Moderate void volume (~0,8 ml/g) • Moderate oil absorption (50-60g oil /100g)
PoleStar 200P Competitor products
C来自百度文库mpetitive Calcined Clays US Grades Asian Grades
Competitive Opacifying Extenders
Talc Precipitated CaCO3
•Satintone W •Satintone Special •Iceberg •IcecapK •Huber 70C •Huber 80C •Snowtex 45
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PoleStar PoleStar Opacilite 400 200P
91.8 97.5 2.8 87.0 1,375
94.9 97.2 4.4 75.0 850
95.5 97.8 13.5 68.0 650
1.7
1.6
2.7
535
390
230
Effect of Calcined Kaolins on Opacity
0.2 Heat Flow (mW/mg) Endothermic 100 Weight Loss (%) 0 Exothermic -0.2 De-hydration 92 96
-0.4
88 -0.6 De-hydroxylation 200 Spinel phase 800 1000 84
400 600 Temperature (oC)
Comparison in matt emulsion paint (74% PVC)
% by Weight
Ti-Pure R-706 *Calcined Kaolin CaCO3 (d50=5μm) Dispex N40/Calgon S (7:1) Ammonia 2% Natrosol 250 MBR Proxel GXL Foamaster NXZ PPG/Texanol (1.4:1) Acronal 290 D Acrysol TT935 Water Total 9 12.0 28 0.4 0.15 15 0.1 0.3 3.4 13 0.8 17.85 100.0
PoleStar 200P PoleStar 400 Flash Calcined Kaolin Opacilite
Interior Matt Emulsion Paints
Major use for calcined kaolin
• Interior walls and ceilings – usually formulated above CPVC
High Structure
High void volume Small voids Irregular particle shape High Oil Absorption Fine particle size
Opacity
Mud Crack Resistance
Scrub Resistance Sheen
Function
TiO2 pigment (DuPont) Functional extender (Imerys) Extender Dispersants (Ciba/JT Baker) pH control Thickener solution/water (Hercules) Biocide (Arch Biocides) Defoamer (Cognis) Coalescing solvents (DOW/Eastman) Styrene acrylate latex (BASF) Thickener (Rohm & Haas)
Compare PoleStar 200P, Opacilite & PoleStar 400
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Effect of Calcined Kaolins on Opacity
Matching 12% PoleStar 200P opacity (74% PVC)
Contrast Ratio at 20m2/l