DEHESIVE® 944 is a solvent-based addition crosslinkable silicone recommended for release coatings.
- medium release at low peel speeds
- good release stability
- excellent bath life
- excellent anchorage to a wide variety of substrates
- suitable for coating PP and PE films and PE-coated paper
The silicone component of DEHESIVE® 944 is contained in the positive lists of BfR XV and XXXVI/2 and FDA §175.300, §175.320, §176.170 and §176.180. However, for compliance of the release coating with the before mentioned regulations the product has to be appropriately cured using a suitable crosslinker and under observance of the limits for platinum. The solvent toluene has to be completely removed.
DEHESIVE® 944 may be used for coating of PElaminated paper, polyester films (PET) and papers
Generally DEHESIVE® 944 is diluted to give a formulation with an active substance content of about 5%. However, depending on the substrate and coater system, DEHESIVE® 944 may be used with lower or higher active substance contents. Special care must be taken to select a high quality solvent that will not poison the Pt-catalyst. Common poisons are organo-tin compounds, sulfur compounds (a common source are rolls that have been vulcanized with sulfur), amines, acid amides, zinc stearate and phosphites. The quality of the coating compound can be ensured by using clean vessels of stainless steel, enamel, plastic or glass to prepare the batch.
Batches of coating compound must be prepared in the order given below.
1. First pour in DEHESIVE® 944
2. Add solvent and stir slowly until the mixture is homogeneous
3. Add CRA® release modifier in case CRA® is used and stir slowly until the mixture is homogeneous
4. Thoroughly stir in Crosslinker to this mixture
5. Slowly stir in catalyst. Local over-concentrations must be avoided.
Suitable solvents are aliphatic and aromatic hydrocarbons (e.g. toluene, white spirit), esters and ketones.
The cure speed depends on the formulation (e.g. the amount of catalyst), type of substrate, quality of solvent, the chosen temperature and the effectiveness of the oven.
Laboratory trials are recommended prior to using the material in production in order to verify that the vulcanization performance suits the intended application.
The 'Best use before end' date of each batch is shown on the product label.
Storage beyond the date specified on the label does not necessarily mean that the product is no longer usable. In this case however, the properties required for the intended use must be checked for quality assurance reasons.