WACKER® HAFTVERMITTLER HF 100
WACKER® HAFTVERMITTLER HF 100 is a reactive epoxyfunctional silicone polymer which, when mixed with addition-crosslinking DEHESIVE® systems or liquid silicone rubbers (LSR) increases their adhesion to polymeric substrates.
- improves anchorage of DEHESIVE® systems on PET films for producing release liners
- improves anchorage of LSR on fabric
- low odour
- low corrosiveness
Spezifische Merkmale von WACKER® HAFTVERMITTLER HF 100
WACKER® HAFTVERMITTLER HF 100 may be used with good success in combination with solvent-free and solvent-based DEHESIVE® systems for siliconising unprimed polyester film grades. WACKER® HAFTVERMITTLER HF 100 improves long term silicone anchorage. In case of very demanding anchorage conditions it can be helpful to combine the use of WACKER® HAFTVERMITTLER HF 100 with a corona treatment of the substrate.
In cases where anchorage on paper substrates like on claycoated paper is difficult to achieve, WACKER® HAFTVERMITTLER HF 100 may be helpful. The adhesion of liquid silicone rubber Elastosil® LR to substrates like PET or polyamide fabric also can be improved by using WACKER® HAFTVERMITTLER HF 100. WACKER® HAFTVERMITTLER HF 100 is not soluble in water and therefore cannot be used in waterbased silicones. For waterborne silicone systems Adhesion Promoter HF 86 would be the additive of choice.
Normally WACKER® HAFTVERMITTLER HF 100 is added to DEHESIVE® formulations as the last component. The recommended standard level of addition in the products mentioned above is in the range of 1-3%. The presence of SiH-functionalty in WACKER® HAFTVERMITTLER HF 100 will result in a higher release level with acrylic adhesives when formulated without compensation of the increased SiH-concentration.
With solvent-free DEHESIVE® systems and with CRA® modifiers, turbidity is observed in the resulting formulation, but this does not have any detrimental effect on the effectiveness of WACKER® HAFTVERMITTLER HF 100. However, reactivity can be reduced to a certain extent, and the dwell time in the curing oven should be adjusted, depending on the amount of WACKER® HAFTVERMITTLER HF 100 used.
Combined with solvent-based, addition-crosslinking silicones WACKER® HAFTVERMITTLER HF 100 improves the adhesion of silicone coatings to polyester films, when other methods, such as corona treatment have not yet produced satisfactory results.
The standard concentration in these systems is
0.1 wt % relative to the ready-to-use formulation including solvent (silicone content normaly 5 wt %).
Detailed recommendations regarding appropiate formulations can be received from the local WACKER representative.