Cilbond® R-7116

Bonding Capabilities:

• Cilbond R-7116 is a one-coat bonding system for compounds used in the friction industry to manufacture products such as original-equipment (OE) and after-market brake pads. Cilbond R-7116 bonds to all metals used for making brake pads, including Zn/Ni coatings.

In-Service Benefits:

• Cilbond R-7116 produces vulcanised bonds exhibiting:
• Excellent static and dynamic fatigue resistance
• Heat resistance exceeding 350°C
• Excellent resistance to fluids including water, oils, and fuels (including diesel and synthetic mixtures such as methanol and toluene), even at high temperatures
• Superior salt-spray resistance, even compared to solvent-based systems
• Brake pads produced using Cilbond R-7116 exhibit good bond retention to shear testing at 350°C.

Processing Benefits:

• After drying, back-plates coated with Cilbond R-7116 are ready for pressing – no further pre-curing is required.
• Cilbond R-7116 can be easily and safely diluted with deionised water – saving on solvent costs.
• Cilbond R-7116 is lead-free and contains just 12% solvent, putting it at the forefront of technology with respect to the environment.
• Cilbond R-7116 is particularly suited to processes involving hot press and cure within the mould.

• Cilbond R-7116 must be applied to carefully prepared surfaces to be effective. Metals should ideally be degreased and grit-blasted with 200 - 400 micron sharp aluminium for aluminium and other non-ferrous metals or chilled iron grit for steels and other ferrous metals.
• Degreasing after grit-blasting improves the environmental resistance of the bonds.
• Alternatively, surfaces can be chemically treated with a proprietary phosphate treatment to maximise adhesion and corrosion resistance, but many phosphate treatments have limited heat resistance at temperatures exceeding 180°C.

Agitation:

• It is necessary to stir Cilbond R-7116 gently yet thoroughly before use. Avoid creating froth or foam. If foaming does occur, stir slowly until reduced to a minimum. Cilbond R-7116 should also be stirred occasionally during use, and for large production runs, stirred continuously.

Brushing:

• Cilbond R-7116 can be brush applied without the need for dilution. If improvement is required, dilute with 10 - 20% deionised water (by weight).

Spraying:

• Cilbond R-7116 is formulated to be ready-to-spray as supplied. If further dilution is required, dilute to give a viscosity within the range of 25 - 30 seconds on a DIN 4 cup using the minimum amount of deionised water (typically 15 - 20% by weight) to achieve a satisfactory spray pattern. Use the lowest gun pressures possible.
• For conventional air pressure spray systems, a fluid pressure of 0.5-1.0 bar is typical, with air pressure typically 2-3 bar, depending on the fineness of the spray required and the initial temperature of the metal.
• A nozzle size of 1.2 – 2.5 mm is recommended for most applications.

Dipping:

• Dilute to give a viscosity within the range of 30 - 35 seconds on a DIN 4 or Ford 4 cup using the minimum amount of deionised water (typically 10 - 15% by weight) and stir continuously. Avoid frothing or foaming.

Roller-Coating:

• For most roller applications, no further dilution is required.

Dilution:

• Recommended diluents include deionised water or deionised water/alcohol blends.

Coating Thickness:

• The above recommendations should give the optimum dry coating thickness for friction bonding of 10 – 30 microns. Note: Thicker coatings may be used, and all coating thicknesses should be validated by the user.

Drying:

• It is important to ensure that Cilbond R-7116 is completely dry before moulding. Any retained water or solvent may cause blisters during the moulding cycle, leading to cement-to-metal failure and reduced corrosion resistance.
• Apply Cilbond R-7116 to pre-heated metal parts (35 - 50°C). Metals can also be put in an oven after coating, but do not exceed 50°C.
• If applying to unheated metal parts, the ambient temperature should ideally be above 20°C, and films should be allowed to dry for at least 60 minutes.
• When applying to grit-blasted metals, pre-heating or heating after coating to above 20°C may be essential to prevent surface defects such as lack of film coalescence, which may manifest as brown resin spots. Although there is no evidence that these resin spots affect bonding or long-term environmental resistance properties, it is advised to modify the process to eliminate resin spotting – see separate Information Sheet.
• It is also possible to dry the coating with cool forced air, provided the humidity is not too high.

Pre-Baking:

• Pre-baking could reduce penetration into the friction compound and is not recommended for brake pad bonding. However, it is important to ensure the coating is completely dry. If not, retained water or solvent may cause blisters (see Drying Section above).

Cleaning:

• Equipment should be cleaned using water or water containing detergent. If Cilbond R-7116 has dried to a hard film, use MEK or MIBK as the cleaning solvent.
• Before using Cilbond R-7116, it is very important that any previous material is thoroughly cleaned out. When visibly clean, wash through with MEK or acetone, particularly the spray heads and nozzles. Finally, flush through with deionised water until all traces of ketone solvent are removed. This is vital, as ketones will cause Cilbond R-7116 to gel.

• Coated parts that are fully dried may be stored for a period of several weeks, provided they are protected from dust, oil vapours, and water.
• This Cilbond grade has been formulated and manufactured using multiple sources of approved raw materials.
• Cilbond R-7116 should be stored/transported between 0°C and 30°C.
• If stored above or below these temperatures, it is recommended to validate the material to ensure it still meets end-use requirements.
• If stored below -5°C, warm slowly and then stir with a high shear to form a smooth and homogeneous mix.
• If stored above 40°C, cool as soon as possible, re-check that the product is within original specifications, and use within 1 month.
• Cilbond R-7116 is free from lead and virtually free from solvent and is supplied in 10-litre, 25-litre containers, and 200-litre stirrer drums. 250ml trial samples are also available upon request.