Phil JonesDirector Technical Marketing & New Ventures

Source B Gibson2002

“NANOTECHNOLOGYA New Way of Looking

at Paper CoatingPigments and

Coating Structures”

“NANOTECHNOLOGYA New Way of Looking

at Paper CoatingPigments and

Coating Structures”

Interesting materials are Formed by Nature

• Deposits of white kaolin lie close to the surface

• They were valuable enough to be dug out by hand

Source: Ries 1914

100

Year

1950

Impa

ct o

n So

ciet

y

1970 1990 2010 2030 2050 2070

Nanotechnology,“The Next Industrial Revolution”

Dr. R. Siegel,

0

Solid State Technology

Biotechnology

Nanotechnology

Source: ten Wold 1998

Nanotechnology 1 to 100 nm

Why Nanotechnology?

• Less space, faster, less material, and less energy

• Novel properties and phenomena• Most efficient length scale for

manufacturing• Intersection of living/non-living

Source: G McCarty 2003

Areas of Nano-technology• Thermal Barriers• Gas / Vapour Barriers• Optical (Vis/UV) Barriers• Information Recording Layers• Molecular Sieves• Absorption/desorption materials• High Hardness Tools• Nano-composite Cements

Assembly:Colloid Chemistry

Atoms

nanoparticles layers

nanostructures

Dispersions andcoatings

assembly

“building blocks”

High surfacearea materials

Functionalnanodevices

Consolidated materials

synthesis

Source: Siegel 1999

Bio-mimetic Processes Leveraging Bio-Technology:Photonics : Meta-Materials

Source: Belcher et al 1999

Source: Busch & John 2000

Light interacts with features similar in size with its wavelength

Photonics Developing New Materials to interact with Light in PreciseWays

Source Sambles 2001

InverseOpal

Self -cleaning Surfaces:

The Lotus LeafEffect

Paper Markets

• Advertising– Magazine– Catalogue– Inserts

• Information– Computer output;– ink-jet, EP– Digital Photography

• Packaging– Point of Sale advertising

© Hannah Jones 2001

Suprastar

Coated Paper Surfaces

Capim DG

Carbital 95

Opti-Gloss

Higher SurfacePorosity

Higher SurfacePorosity

Slower Setting

Slower Setting

Source: R Wygant 1999

The Way That Light Interacts with the Surface Determines Appearance

Atomic ForceMicroscopyImage ofPaper Surface

Specular, Diffuse, Angular variation

suminagashi

The way that light interacts with the surface determines appearance

• Specular• Diffuse• Angular variation

Source: Quinteros 1999

Gloss vs Surface Roughness

0102030405060708090

100

0 0.1 0.2 0.3 0.4 0.5 0.6

Roughness micron

Tapp

i Glo

ss

20deg45deg60deg75deg85deg

Source D I Lee, 1986 Tappi Coating Conference

0.1 micron = 100 nm

clay +10 pphSBR latex

Prepared cryogenicallyfor SEM

Wetstate

In order to bind, latex particles need to form a film

clay +10 pphSBR latex

Prepared cryogenicallyfor SEM

Wetstate

Air-drystate

In order to bind, latex particles need to form a film

90

80

70

60

50

40

Drying Time

75

oG

loss

or

Ref

l ect

a nce

Ro

75o Gloss

Ro

Source Lepoutre 1985

75

oG

los s

or

Re f

lect

a nce

Ro

Solids volume % Concentration

100

90

80

70

60

50

40

3040 50 60 70 80 90 100

Ro

75o Wet Gloss

GlossFreeze Dried

FCC

SCC

Source Lepoutre 1985

Fundamentals of Print GlossInk Setting and Levelling

Ink Setting

• Fast Setting allows less levelling and hence lower ink gloss

• Fast Setting is given by– Large pores

– High pore volume

– Low tortuosityblocky pigment platey pigment

‘ink bottle’ pore pore junction

0100200300400500600700800

0 30 60 90 120 150 180 210

Time after Printing ( Seconds )

Max

Sep

arat

ion

Forc

e--

----

----

->

Fastest SettingSlowest Setting

FastSlow

Ink Surface

Source: J Preston 1999

• Characterization Techniques from micro-electronics Industry have improved knowledge of pigment structures– Atomic Force Microscopy– Field-Emission

Scanning Electron-Microscopy– Mercury Porosimetry– Microcalorimetry

Pigment StructurePigment Structure

© Hannah Jones 1999

Minerals are Now Produced in Refineries: Selecting Shapes and Sizes

• Major Kaolin Crude Sources– U K – Georgia– Brazil

• Calcium Carbonates – Merchant Plants

• Ground Calcium Carbonates– Satellite Plants

• Ground Calcium Carbonates• Precipitated Calcium Carbonates

• Delamination/Grinding (Cracking)• Particle Size Selection (Distillation)• Precipitation (Synthesis)• Aggregation (Polymerization)

A range of products is made from a kaolin feedstock

• Finer particle size gives higher gloss

• Fine blocky particles give lower ink gloss

• Fine Platey particles give higher ink gloss

• Delaminated made from coarse residues and is very platey

0

10

20

30

40

50

60

70

80

90

100

110EQUIVALENT SPERICAL DIAMETER, MICRONS

WT

% F

INER

TH

AN

FeedFine #1#1#2Delaminated

Fb

Fg

gFv

ρ2

ρ1

s

Rs

ρ2= density of solid

Fb = Bouyancy Force

Fg = Force due to Gravity

S = velocity of particle

g = gravitational constant

ρ1= density of liquid

Fnet = Fg- Fb = V( ρ2-ρ1)g

Fnet = (4/3)πR3( ρ2-ρ1)g

R = ( )9 ηs 2(ρ2-ρ1)g

1/2 Stokes’ Law

η = viscosity of liquid

s = terminal velocity of particleρ = density

g2R2( ρ2-ρ1)9 ηS =

ESD: Equivalent Spherical Diameter

C JPEJ 2000O

The TEM shadowing techniqueThe TEM shadowing techniqueFor a given shadow angle, particle thickness (t) is proportional to shadow length (l)

Example TEM image

Pt-C vapour coating

Particle Shadow

Source: J Husband 2002

0.05

0.4

1

1.6

2.2

60

120

180

0

20

40

60

80

100

Nano-Mineral Sizes and Shapes

0

5

10

15

20

25

30

0 20 40 60 80 100 120 140 160 180 200 220Crystal Thickness Nanometers

Num

ber

Mine C

Mine AMine B

Crystal Thickness

Shape & Size Distribution

Diametermicron Thickness

nm

Source: R Pruett 1997

Source Golley & Dover 1989

Calculating disc diameter from esd and shape factor measurements

d

t

SF = dt

esdd = [2.356

SF ]0.5*

*Jennings & ParslowSource J Husband 1997

Measurement of esd does not discriminate between delamination and transverse fracture

3.0 µm1.5 µm

SF = 20:1 SF = 10 : 1esd = 0.84 µm esd = 0.60 µm

OR

SF = 40 : 1

esd = 0.60 µm

3.0 µm

Source J Husband 1997

Diameter

1

2

3

4

5

0 10 20 30 40 50 60

Aspect Ratio (L/t)

Dia

met

er (L

, µm

)

t

Thickness

00.10.20.3

0.40.50.6

0 10 20 30 40 50 60

Aspect Ratio (L/t)

Thi

ckne

ss (t

, µm

)Disc Diameter and Thickness

L

1 1 µµm e.s.d. Discm e.s.d. Disc

A given e.s.d. measured by SediGraphTM can refer to very different particles.

Source J Husband 1997

% < 2 μ

Mean ESD μ

ShapeFactor

Diameterμ

Thickness nm

Ultra-FineGlossing

98 0.2 5 0.29 58

Ultra-FinePlatey

98 0.2 45 0.89 19

#2 Clay 80 0.4 10 0.82 82

Delaminated 80 0.55 30 1.96 65

Capim DG 90 0.51 12 1.15 96

Contour1500

90 0.5 60 2.52 42

Hyperplatey 50 2.0 100 13.0 130

Sedigraph measurements are not the whole story

40

45

50

55

4 5 6 7 8Coat weight gsm

Cal

ende

red

glos

sSuper Platey60:1

Standard delaminated30:1

+8units

Super Platey Clay in 30# offset formulation

Source: Husband: 1999

0.5

0.75

1

1.25

4 5 6 7 8Coat weight gsm

Park

er P

rint S

urf S

moo

thne

ss,

µm

Super Platey60:1

Standard delaminated30:1

1.8 gsm

Super Platey Clay in 30# offset formulation

Source: Husband: 1999

Effect of particle shape on mechanical properties : tensile index of kaolin / GCC (C90) blends

High shape factor clays increase tensile strength in blends with GCC. 20pph XP increases tensile by 0.55 Nmg-1 cf. 20 pph Alphalux. This is the same as 5 pph latex (see next slide).

R2 = 0.8522

R2 = 0.9581

0.001.002.003.004.005.006.007.008.00

0 20 40 60 80 100% kaolin

Tens

ile s

tren

gth

M P

a Fine platey

Fine blocky

12 pph latex, 0.3 pph CMC. Coatings made on plastic film, peeled off and tensile strength measured. Average of 13-18 measurements / sample.

• Self Assembly of building blocks– Optical performance– Ink interactions– Blister Resistance– Dot Shape– Water uptake in Ink-jet– Thermal Barrier for EP

Selection of Shapes and Sizes Building Functional Performance

Selection of Shapes and Sizes Building Functional Performance

Particles and Pores of similar size as wavelength of light

Light of Similar Wavelength as objectLight of Similar Wavelength as object

Light of Similar Wavelength as PoreLight of Similar Wavelength as Pore

Light is diffracted and scattered by

small objects

Control of Pore Size and Volume

Blending enables a wide range of pores structures to be developed enabling balance between optics, print snap and blister resistance and dewatering to be changed

Blending enables a wide range of pores structures to be developed enabling balance between optics, print snap and blister resistance and dewatering to be changed

0

20

40

60

80

100

120

140

160

0 10 20 30 40 50 60 70

Pore Volume cc/kg

BlendsUK ClayUS ClayBraz ClayGCCPCC

Bubble Size refers to relative Pore Density

Brightness and Print Gloss with Pigment Blends

70

71

72

73

74

75

76

50 55 60 65 70 75 80Print Gloss 75°

Shee

t Brig

htne

ss IS

O

StandardBlends

EngineeredBlends

OptimisedSolutions

HelicoaterTM Data, 1000m/min, Latex/CMC FormulationData refers to PCC/GCC + US/Brazilian/UK kaolins

Standard Clay-Carbonate blends trade brightness and print gloss.Certain, but not all, Engineered pigment blends offer step changes in

brightness while maintaining high print gloss.

Standard Clay-Carbonate blends trade brightness and print gloss.Certain, but not all, Engineered pigment blends offer step changes in

brightness while maintaining high print gloss.

Optimised Solutions

Opti-Print PCC

Brightness v Opacity with Pigment Blends

70

71

72

73

74

75

76

83.5 84.5 85.5 86.5 87.5Opacity

B'n

ess

Kaolins

Carbonates

Standard Blends

Engineered Blends

Optimised Solutions

Optimised Solutions

0

0.2

0.4

0.6

0.8

1

0 0.1 0.2 0.3Filler volume fraction

Rel

ativ

e Pe

rmea

bilit

y (P

/Po)

SpheresCylindersPlates A.R. 30 Plates A.R. 100

Platy Minerals as a Barrier MaterialCussler et al. J. Membrane Sci. 231, 1-12

Barrier Formulation (3- European Project)• RC-latex used in existing Imerys benchmarking experiment

•50% solids•final coatweight: 10-12 gsm

0

50

100

150

200

250

Paper latex only latex + filler

MVT

R (g

/m2d

ay)

Pore Structure the Drive