High transparency and reduced shrinkage

Highly transparent and low viscous formulations despite high filler loads - Nanocryl® A makes it possible! But that is by far not the end of the story: a large scale of further properties can be improved signifcantly with Nanocryl® A, e.g. reduced shrinkage upon cure and heat of reaction. 

Product overview
Improvements to properties
How it works

Product overview [back]

Technical data (no specification)

Note: Further Nanocryl® A products and mixtures for special applications are available on request. Please contact our application specialists.
 
Improvements to properties [back]

Nanocomposites can also be used in UV-curing systems for the electronics industry. The use of Nanocryl® A or of Nanopox® E 600 in the formulation enable a whole range of material properties to be significantly improved.

The products are highly transparent, low viscous and do not show any sedimentation, i.e. the processability remains essentially unchanged in comparison to the respective base resin. This way, the individual advantages of organic and inorganic materials can be combined almost perfectly.

Important material properties which can be improved by the use of Nanocryl® A are:

• no reduction in the transparency despite high filler content 
• reduction of shrinkage upon cure and heat of reaction 
• reduced thermal expansion and internal stresses  
• barrier effect against gases, water vapor and solvents
• increased weather resistance and inhibited thermal aging
• greatly improved scratch and abrasion resistance
• increase in tear resistance, fracture toughness and modulus
• improved adhesion on numerous inorganic substrates (e.g. glass, aluminum)
• improvement in a number of other desired properties, such as: thermal stability, stain-resistance, heat conductivity, dielectric properties

Nanocryl® A is used in applications where the above improvements to properties are desired or necessary, without compromising processability by an excessive viscosity increase (as known from e.g. fumed silica). The fact that this is possible without the loss of optical clearness makes Nanocryl® A particularly suitable for transparent formulations. Application examples are: highly scratch-resistant coatings for fiber optic cables, conformal coatings, UV curing adhesives for printed circuit boards (PCBs).

How it works [back]

Nanocryl® A products are colloidal dispersions of up to 50 wt% amorphous silica in a wide range of conventional unsaturated (meth-)acrylate monomers and oligomers. The dispersed phase consists of surface-modified, spherically shaped SiO2 nanoparticles with diameters of 20 nm and an very narrow particle size distribution (Fig. 1).

Figure 1:  Particle size distribution (determined by SANS)

The SiO2 spheres are distributed homogenously and agglomerate-free in the resin matrix (Fig. 2). This results in a very low viscosity of the dispersion despite SiO2 contents of up to 50 wt%.  

Figure 2:  TEM – images of a cured Nanopox® sample with 5% silica nanoparticles

The nanoparticles are synthesized from aqueous sodium silicate solution in a chemical process. In this unique process the binding agent is not damaged, in contrast to processes in which powdered fillers are dispersed with dissolvers or other machines using high shear forces.

For further details, please contact our application specialists.