E

VM

-2/4

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11/0

610

39

80

calcined neuburg siliceous earth

Publisher: HOFFMANN MINERAL GmbH

Muenchener Strasse 75 • 86633 Neuburg (donau) • Germany Phone +49 (0) 84 31-53-0 • Fax +49 (0) 84 31-53-3 30

info@hoffmann-mineral.com • www.hoffmann-mineral.com

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Structure and Mineralogical Composition The Genesis of Neuburg Siliceous Earth

Classic Neuburg Siliceous Earth – also called Sillitin and Sillikolloid – is a natural combination of corpuscular, crypto-crystalline and amorphous silica and lamellar kaolinite: a loose structure impossible to separate by physical methods. This base material and a down-stream thermal process lead to a calcined product which in compa-rison with standard grades offers additional application benefits as a functional filler. The typical particle structure of Neuburg Siliceous Earth with nano-scale primary particles remains unchanged by the heat treatment.

Fig. 1

The base for the calcined products is the standard grade Sillitin Z 86 which has long been used in a multitude of applications. The calcination of the Sillitin (Fig. 2) helps to drive off the crystal water present in the kaolinite portion and to generate calcined kaolinite. The crypto-crystalline silica portion remains inert under the tem-perature chosen; this is why the final product is free from crysto-balite. Through an integrated air classifier process grain sizes > 15 µm are being removed.

Neuburg Siliceous Earth is a sediment, which was deposited 95 million years ago on the limestone strata from the later Jurassic period and fell in so-called karst funnels where it was preserved.

Fig. 2

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97 %

50 %

Three grades of calcined Neuburg Siliceous Earth are presently available:• the base product Silfit Z 91 • two surface treated products:

· Aktifit AM treated with amino silane· Aktifit VM treated with vinyl silane

All calcined products show nearly a comparable particle size distribution to the basic material Sillitin Z 86.

The determination of these particle size distributions was based on Fraunhofer diffraction spectra. The analyses were run on a laser instrument Mastersizer S from Malvern.

Grain size distribution of calcined Neuburg Siliceous Earth in comparison with standard grades

Silfi t Z 91, Aktifi t AM, Aktifi t VM Sillitin Z 86

90

80

70

60

50

40

0

20

30

10

50 20 10 1 0.5 0.2 0.1

100

2.0

9.010.0

1.9

D(x) in %

x in µm

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Color value according to CIELAB

With respect to the color values L*, a* and particularly b* the calcined products are much more color neutral than not calcinated Neuburg Siliceous Earth.

Aktifit AM

Aktisil AM

Silfit Z 91

Sillitin Z 86

Aktifit VM

Aktisil VM 56

incr

easi

ng c

olo

r ne

utra

lity

L* = 94a* = 0.1b* = 1.6

L* = 92.5a* = 1.5b* = 8.5

untreated amino silane treated vinyl silane treated

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Product Characteristics of and

EINECS-No.: 310-127-6CAS-No.: 1214268-39-9 (Siliceous Earth, calcined)CAS-No.: 7631-86-9 (Silica), 92704-41-1 (calcined kaolinite)TSCA-No.: 7631-86-9 (Silica), 92704-41-1 (calcined kaolinite)

Characteristics Unit Method Silfit Z 91 Aktifit AM Aktifit VM

Basic material – Silfit Z 91 Silfit Z 91

Surface modification – Amino silane Vinyl silane

Color value L* a* b*

acc. to CIELAB940.11.6

940.11.6

940.11.6

Particle size D50

D97

m m

Internal test procedure Internal test procedure

210

210

210

Residue > 40 m mg/kg DIN ISO 787 part 18 20 20 50

Volatile Matter at 105 °C % DIN ISO 787 part 2 0.3 0.3 0.3

Electrical conductivity S/cm DIN ISO 787 part 14 20 60 60

Density Bulk density Tamped density

g/cm3

g/cm3

g/cm3

DIN ISO 787 part 10 DIN ISO 903-1976 DIN ISO 787 part 11

2.60.340.60

2.60.320.60

2.60.400.70

BET Surface area Oil absorption

m2/g g/100 g

DIN ISO 9277 DIN ISO 787 part 5

7.560

7.560

760

Hardness: silica/calcined kaolinite acc. to Mohs 7/4.5 7/4.5 7/4.5

Refractive index n sin /sin 1.55 1.55 1.55

Water solubility Acid solubility

%DIN ISO 787 part 3 DIN 53 770 (0.1 n HCl)

insoluble 0.25

insoluble 0.25

insoluble 0.25

pH value DIN ISO 787 part 9 7 9 7

Chemical analysis: SiO2 Al2O3 Fe2O3

% % %

DIN 51001 (XRF)DIN 51001 (XRF)DIN 51001 (XRF)

86 12 < 1

86 12 < 1

86 12 < 1

Mineralogical composition: Crypto-crystalline silica Calcined kaoliniteAmorphous silica

% % %

based on X-ray diffraction pattern analysis combined with Rietveld

603010

603010

603010

Water absorption % acc. Baumann – – 0.02

The values shown in the table are to be considered as guidelines only. Material specifications and technical data sheets for all products are part of our sales conditions and are available on our web site www.hoffmann-mineral.com

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Benefits:• low sieve residue• very low moisture content, low moisture absorption• very high level of brightness• very high color neutrality• efficient and rapid incorporation• outstanding dispersion, also in critical compounds• good flow properties• outstanding surface quality• excellent extrusion properties• no negative influence on curing rate• low tensile and compression set• high electrical resistivity• favorable aging resistance• high resistance against chemicals• matting effect• meets the requirements for articles in contact with food products according to BfR and FDA• optimum combination of extrusion properties and compression set (within the untreated grades)

Polishing and cleaning agentsPotential application areas:• Glass-ceramic cooktop panel cleaner• Toothpaste• Polishes

Advantages:• high brightness and color neutrality• balanced ratio between cut and gloss

Potential application areas:• washing machine gaskets• car body seals• building profiles

Z 91ElastomersSilfit Z 91 is suited for all technical rubber goods. The filler is distinguished by a balanced ratio of tensile strength, tear resistance, low compression set and excellent extrusion properties. It is particularly well suited for very light-colored or white compounds.

Silfit Z 91 offers further advantages:• when high requirements are placed on the dispersion

properties, as for instance · in compounds with a high oil content, · for extruded automotive profiles with very low surface

defect rates, · for extremely thin-walled articles like membranes, · when requirements are placed on high surface quality as in printing rollers and printing matrices,• prevention of filler caused mold fouling during the injection

process or deposits in the orifice die (plating) during extrusion

Application areas and benefits of calcined Neu burg Siliceous Earth

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Paints and coatingsPotential application areas:• Dispersion and silicate paints• Industrial coatings• Wood and foil coatings• Primers and primer-surfacers, also in the automotive industry• Electrodeposition lacquers (anionic and cationic)• Coil coatings• Powder coatings• Road marking paints• Adhesives and sealants

Advantages:• low sieve residue• low moisture content, low moisture absorption• very high brightness and color neutrality• excellent dispersion, even without grinding • improvement of opacity (spacer effect) • pigment replacement potential (e.g. TiO2)• fairly low abrasivity• rapid drying• good weathering resistance• high scratch resistance• good abrasion resistance• good transparency• matting effect (depending on the formulation) • meets the BfR and FDA requirements for articles in

contact with food products

AMThermoplasticsApplication areas are always open where low warping along with high surface quality are of similar importance as good melt flow properties, high elongation at break and high impact strength even in the dry-as-mold-state.

Potential application areas:• Visible parts and covers under the hood• Wheel caps• Handles• Casings

In general: products demanding high degree of dimensional stability and surface quality

Preferentially, polyamides, and in particular PA 6.6. Basically other engineering thermoplastics and polar plastics such as PE/EVA, PVAC etc.

Pho

to: B

MW

AG

Mün

chen

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Benefits:In comparison with unfilled polymer, Aktifit AM offers the following benefits:• lower processing shrinkage• higher hardness• increased stiffness• higher tensile and flexural strength• improved heat distortion temperature• better dimensional stability at changing moisture (polyamides)

In comparison with other mineral fillers, Aktifit AM shows the following advantages:• very low sieve residue• easy metering• good wetting and dispersion properties• high melt flow rate

• low warpage/isotropic processing shrinkage• excellent surface quality• excellent high elongation at break• extraordinary high impact strength

Paints and coatingsPotential application areas:• Reactive industrial coatings• Baking enamels • Anti-corrosion coatings• Primers and fillers, also in the automotive industry • Coil coatings• Powder coatings• Adhesives and sealants

Benefits:• low sieve residue• low moisture content, low moisture absorption• very high brightness• very high color neutrality• outstanding dispersion properties, even without grinding• improvement of opacity (spacer effect) • pigment replacement potential (e.g. TiO2)• fairly low abrasivity• rapid drying• good weather resistance• good transparency• matting effect, depending on the formulation• effective wetting, also when working with binders of low polarity• very good abrasion and scratch resistance• high resistance against chemicals

Property profile of Aktifit AM in polyamide 6.6 Filler loading 40 %, dry as molded

Aktifit AM Calcined clay surface treated

Wollastonite surface treated

Impact strength

Tensile strength

Melt flow rate (by volume)

Tensile modulus Elongation at break

Notched impact strength

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VMElastomersApplication areas offer themselves wherever high tensile strength and high tensile moduli along with low tensile and compression set are required. Equally important as excellent processing and extrusion properties is the prevention of filler caused mold fouling during the injection process or deposits in the orifice die (plating).Aktifit VM is particularly suited for very light-colored or white compounds. These properties represent an ideal combination for pressureless cured extruded products and sponge rubber.

Potential application areas: • extrusions for pressureless cure (profiles, hoses)• cable jackets and insulation compounds, also for high voltage• sponge rubber articles• molded products and seals• condensor gaskets

Benefits:• low sieve residue• low moisture, low moisture absorption• very high brightness• very high color neutrality• good and quick incorporation• excellent dispersion, even in critical compounds• good rheological properties• outstanding surface quality• outstandig extrusion properties• no negative influence on curing rate• low tensile and compression set• high electrical resistivity• good aging properties• very good resistance against fluids and chemicals• matting effect• very high tensile strength• tensile strength maximum at high filler loading• higher tensile moduli• very good abrasion resistance• high and constant electrical resistivity upon water immersion• low dielectric loss

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Product Paper bag PE bag EVA bag Big Bag Bulk

Silfit Z 91 on request on request on request 600–900 kg 24 t

Aktifit AM on request on request on request 600–900 kg 24 t

Aktifit VM on request on request on request 600–900 kg 24 t

Packaging