© 2020PQ Corporation. 1

PQ Corporation

Silica Gels Webinar

PQ History

Our NA side, founded in 1831 as

“Joseph Elkinton’s Soap & Candle

Manufactory” and changed to

Philadelphia Quartz in

1864…now known as PQ

Corporation.

Our European side, founded in

1815 as Joseph Crosfield and

Sons Ltd. in Warrington, England

as a soap manufacturer. Changed

hands and names a few times and

most recently prior to merger, was

Ineos Silicas.

Joseph CrosfieldThomas Elkinton

PQ Today

• Headquarters in Malvern, Pennsylvania

• Annual sales revenue US over $1.6 billion

• About 3,000 employees

• Over 67 manufacturing sites in 19 countries on 5 continents

• Silicas and silicates used in many markets including coatings, construction, and oil field.

Wesley E. Robertson – Technical Manager

PQ Corporation

Silica-Gel Technology as Matting Agents in

Coatings

Types of Synthetic Silicas

Manufacturing Process/Locations

What is Silica-Gel?

Benefits and Limitations

Where is Silica Gel Used?

How is it used?

Product Selection

General Industrial Systems

Wood Systems

Matting Agents for Inks and OPV’s

Gasil Silica Gel Products

Silcron G-100

Advera Ti

Manufacturing Locations

Objectives

PQ’s Xerogel

Process

Joliet IL

Manufacturing Locations

Warrington, England

Synthetic amorphous silicon dioxide manufactured under tightly controlled

conditions to give the desired properties.

Sponge-like structure with a well defined porosity.

Low Pore Volume (LPV) Silica absorbs moisture vapor but have poor carrying

capacity for liquid systems. (Gasil GM2). Dense structure makes this type of product

suitable where particle strength is important.

Medium Pore Volume (MPV) Silica are used in High Solids Applications and Systems

where lower formula viscosity is needed.

Ultra High Pore Volume (UHPV) Silica are the most effective as matting agents

because they offer more SiO2 particles per unit weight. They possess a lower bulk

density which can create a thickening effect.

What is Silica-Gel

Silica Matting Agents

x5000

Low density

particulates with

controlled particle

size distribution

and high purity

Average Particle Size (APS) measured in microns @ Equal Pore Volume (PV)

Higher the micron size the more efficient for optical performance (Gloss)

Lower the Micron size the less efficient

Particle Size Distribution @ Equal Pore Volume (PV)

The narrower the distribution curve the more efficient the optical performance (Gloss).

The larger the distribution curve the less efficient

Particle Size and Distribution

Silica particles create a micro-roughness on coating surface.

Rough surfaces scatter light rays thus reducing gloss.

Matted Surface Viewed With SEM

Pore Volume

Low Pore Volume 0.4 ml/g Medium Pore Volume 1.2 ml/g Ultra High Pore Volume 1.8 ml/g

Matting Effectiveness 2.7 Matting Effectiveness 1.4 Matting Effectiveness 1.0

SiO2 Air

Pore Volume influence on Matting

Efficiency

MPV

UHPV

Polyester Coil Coating

0.5 mils DFT

8 µm APS of silica

2 3 4 5 60

10

20

30

40

50

60

70

% silica

Gloss@ 60

Degrees

1.2 PV

1.8 PV

Coatings Market Segment:Automotive (Interior)

General Industrial OEM

Architectural Coatings

CoilConstruction/Appliance/Transportation/HVAC/MOF

Furniture (Wood and UV Coatings)

Leather

Paper

Inks

Successful Markets

Coil Coatings

General Industrial (OEM)

Roof Coatings

Wood and UV Coatings

Decorative Coatings

Where is Silica-Gel Used

Advantages Disadvantages

Fumed Silica

Very Efficient

Minimal Effect on Clarity

Very Expensive

Builds Viscosity and Dusting

Precipitated

Silica

Easily Dispersed

Less Expensive

Only Neutral to Alkaline grades

Shear Sensitive/Friable

Builds Viscosity

Can give white/blue tones in

clear systems

Silica Gel Narrow Particle Distribution

Resistance to Over-grind

Efficient Matting

Acidic Grades for Acid Catalyzed

systems

Moderate Price

Benefits and Limitations of

Synthetic Silica

Coating Property Silica Property

Gloss Requirements Particle Size/Pore Volume

Dry Film Thickness Particle Size

% Solids (NVM) Particle Size Pore Volume

Viscosity Requirements Particle Size/Pore Volume/OA

Solvent or Waterborne pH

Acid Catalyzed pH

Pigmented or Non-pigmented Surface Treatment

Product Selection

Raw Material Selection

Resins, Additives, Pigments and Solvents

Order of Addition

Synergistic effects

$$ Cost

Millbase Optimization

Pigment to Binder Ratio (P:B)

Shear Rate

Dispersion

Stabilization

Letdown

Continual Mixing and Catalyzing phase

Formulation

Product Selection

High Batch Temperatures (> 140 deg. F.)

Millbase not balanced.

Solvent Shock

Acid Shock

Formulation Pitfalls

Raw material selection

Synergies

Order of addition

Rate of addition

Keys to Successful

Formulation

Break-up of particle agglomerates

Wetting

Stabilization

Letdown

Keys to Successful Silica

Formulation

High Speed Disperser

Cowles type stirrer

Milling Equipment

High Speed Disperser

Cowles type stirrer

General Industrial Systems

0

20

40

60

80

100

1% 2% 3% 4%

Silica Gel

Precipitated Silica

60o Gloss Comparison of Silica-Gel versus

Precipitated Silica in a White GI Formulation

0

400

800

1200

1600

2000

2400

2800

3200

cps

1% 2% 3% 4%

Silica Gel

Precipitated Silica

Viscosity Comparison of Silica-Gel versus

Precipitated Silica in a White GI Formulation

Solvent Borne Clear Systems

Treated Silicas are best suited for clear systems.

Untreated Silicas are best suited for pigments systems.

Acidic silica's are best suited for Solvent based systems.

Neutral silica's are best suited for water based systems.

Pigmented vs Clear Systems

0

10

20

30

40

50

60

70

80

90

100

2% 4% 6% 8%

Loading

Gloss

HP240J HP210 HP220

Optical Characteristics of

Gasil Silica in a Polyurethane

Wood Coating

0

50

100

150

200

250

300

350

0% 2% 4% 6% 8%

Loading

Viscosity(cps)

HP240J HP210 HP220

Physical Characteristics of

Gasil Silica in a Polyurethane

Wood Coating

Synthetic Silica-Gel (New Development)

Manufactured in the UK

Comparable properties to TS100Viscosity

Clarity

Potential Cost Savings

ApplicationUltra High Efficient Silica Matting Agent. Suitable for Wood,

Coil and General Industrial Coatings. It performs well in

Water-Based Formulations.

PV – 1.8 mL/g

APS (D50) - 9.5 μm

pH (5% acq.suspension) - 4.5

Loss at 1000C 8% Max

Oil Adsorption (Linseed) 390g/100g

Surface Treatment - None

Gasil XE3100

Properties Gasil HP335 Gasil UV70C Gasil HP380 Gasil HP710

APS (Malvern 100 mm lens) microns 4 7.5 7.7 10.0

Pore Volume (mL/g) 1.8 1.8 1.8 1.8

pH (5% aqueous suspension) N A N N

Loss @105 deg. C (%) 2 2 2 2

Loss @1000 deg. C (%) 12 14 12 12

Oil Absorption, Linseed (g/100g) 250 250 250 250

Surface Treatment PE* PE PE* PE*

* High MW PE Wax

Silicas for UV Curable Coatings

Properties Gasil IJ35 Gasil IJ37 Gasil 23D Gasil HP230 Gasil HP33C

APS (Malvern 100 mm lens) microns 5.2 6.3 4.4 3.6 3.3

Pore Volume (mL/g) 1.2 1.2 1.8 1.6 1.8

pH (5% aqueous suspension) N N N N N

Oil Absorption, Linseed (g/100g) 250 250 250 250 250

Surface Treatment Paraffin

* High MW PE Wax

Matting Silicas for Solvent and Water

Based INKS and OPV’s

Gasil Silica Gel Products

High Pore VolumeHP210

HP220

HP230

HP240J

HP33C

HP260

HP270

HP280

HP290

HP335

HP380

HP710

HP860

HP870

HP880

HP39

XE3100

UV70C

23F

PQ Corporation Silica-Gel

Products (Gasil)• Medium Pore Volume

– IJ37

– IJ35

– IJ24

– IJ1

– IJ45

• Low Pore Volume

– 200DF

– GM2

Silcron

G100

G130

G300

G500

G520

G601

PQ Corporation Silcron Products

Silica Gels

A high performance

zeolite-based product

for the partial replacement

of TiO2 in paints, offering

significant cost savings

ADVERA® Ti

ADVERA® Ti

What is ADVERA® Ti

• A high performance zeolite-based product

• Allows partial replacement of TiO₂ with no adverse

effects on paint properties.

Typical Properties of

ADVERA® Ti

Average Particle Size (Malvern Mastersizer) 3.0-4.0µ

Loss at 800°C 18-21%

Specific Gravity 2.0-2.3

pH (1% aqueous solution) 10.5-11.5

Oil absorption (Linseed) 20-30 g/100g

Color (L Brightness) 97-98%

Bulk Density 30-50 Lb/ft³

Retained on 325mesh screen <0.5%

Benefits of ADVERA® Ti

• Improved hiding

• TiO₂ spacing

• Fine particle size

• Low oil absorption

• High hydrophilic characteristics

• Low specific gravity

Matting Agent Efficiency Test

Coating FormulationQuantity of silica to achieve a gloss of 20

DFT of 1.0 mils

0 1 2 3 4 5

4.5

4.3

3.6

3.3

2.9

2.8

Silica type

Wt % silica to achieve Gloss of 20

6.4

6.6

8.0

8.7

10.5

12.0

APS

• Wax treated products are recommended when hard settling problems are

encountered.

• Acidic grades are recommended to enhance dispersion characteristics in

solvent based systems.

• Neutral grades are recommended in water-base formulations.

• Gloss reduction result of silica particles creating uneven surface which

scatters light.

• Efficiency of silica matting agent increased by increasing pore volume and

producing a narrow particle size distribution.

• The use of high efficiency matting silica can reduce raw material and plant

manufacturing costs and improve physical properties of coating.

• Consistency of synthetic silica can only achieved by using state-of-the-art

plants that controls Pore Volume, Particle Size, and pH.

Summary

Questions?