Cilbond R-7296W is a water-based primer, which may be used in combination with Cilbond cover-coat bonding agents to bond a wide range of elastomers to metal and plastic substrates during the moulding process. With the correct surface preparation, Cilbond R-7296W will prime the following metal substrates: Mild and Stainless Steel, Aluminium, Brass, Galvanised / Zinc Coated Steel, Chromated Zinc and Phosphated Steel. Cilbond R-7296W will also prime polar plastics including nylons, polyesters, cellulosics, PPO, PPS, PES,PEEK, GRP/FRP, epoxies and phenolics, etc. Cilbond R-7296W is particularly versatile when used with the water based cover-coats Cilbond 70W or Cilbond R-7290W, but can also be used under the solvent-based cover-coat Cilbond 80ET to bond NR, SBR, IR, BR, CR, IIR, EPDM, NBR, HNBR and Vamac. Bonds have excellent resistance to extreme environments and aggressive liquids such as glycols, oils and brake fluid.
Technical Data Sheet

Enhanced TDS

Identification & Functionality

Features & Benefits

Product Benefits

Bonding Capabilities:

  • Cilbond® R-7296W is a water-based primer, which may be used in combination with Cilbond cover-coat bonding agents to bond a wide range of elastomers to metal and plastic substrates during the moulding process.
  • With the correct surface preparation, Cilbond® R-7296W will prime the following metal substrates:
  • Mild and Stainless Steel, Aluminium, Brass, Galvanised / Zinc Coated Steel, Chromated Zinc and Phosphated Steel.
  • Cilbond® R-7296W will also prime polar plastics including nylons, polyesters, cellulosics, PPO, PPS, PES, PEEK, GRP/FRP, epoxies and phenolics, etc.
  • Cilbond® R-7296W is particularly versatile when used with the water based cover-coats Cilbond® 70W or Cilbond® R-7290W, but can also be used under the solvent-based cover-coat Cilbond 80ET to bond NR, SBR, IR, BR, CR, IIR, EPDM, NBR, HNBR and Vamac.
  • Bonds have excellent resistance to extreme environments and aggressive liquids such as glycols, oils and brake fluid.

In-service And Processing Benefits:

  • Exceptional boiling water resistance – Tests using Cilbond® 70W and Cilbond® R-7290W as cover-coats to produce NR / Steel parts passed 1000 hours in boiling water.
  • Excellent salt-water resistance and is superior to many solvent-based primers, showing 3mm edge failure after >500 hours in 5% salt spray at 35°C, with a 30% extension of the test specimens when used under various Cilbond cover coats.
  • Excellent resistance to glycols at temperatures up to 160ºC for up to 1000 hours (when used under Cilbond® 70W or Cilbond® R-7290W cover-coats).
  • Cilbond® R-7296W contains no toxic heavy metals, yet produces bonds with excellent heat resistance, up to at least 200ºC.
  • Also compatible with Cilbond solvent-based cover-coat systems such as Cilbond® 80ET.

Applications & Uses

Segment
Metal Surface Preparation

Cilbond® R-7296W must be applied to carefully prepared surfaces to be effective. Ideally, metal surfaces should be degreased and grit-blasted with 200 - 300-micron clean, sharp alumina for non-ferrous metals or chilled iron grit for ferrous metals. Degreasing after grit-blasting improves the environmental resistance of the bonds. Alternatively, a proprietary phosphate treatment on steel or aluminium may maximise corrosion resistance.

Product Application

Agitation:

  • Cilbond® R-7296W contains materials that settle, so thorough stirring before use and occasional stirring during use is essential. For large-scale production runs, continuous stirring is recommended. If foam or froth is produced, stir slowly until it has subsided.

Brushing:

  • Cilbond® R-7296W may be applied by brushing as delivered.
  • Dilution with up to 15% deionised/distilled water may improve flow.
  • Use steady brush strokes in one direction only and do not over-coat.
  • Dipping / Roller-Coating / Doctor-Blade:
  • Dilute using the minimum amount (typically 5 - 15%) of deionised or distilled water to give viscosity within the range of 18 - 26 seconds on a Zahn 2 cup, or 16 - 24 seconds on a DIN 4 or Ford 4 cup.
  • Stir continuously and avoid frothing/foaming.

Spraying:

  • Depending on the spray equipment being used, Cilbond® R-7296W may be ready to spray as supplied and generally requires no further dilution.
  • If dilution is required, add up to ca. 10% diluent.
  • A nozzle size of ca. 1.0 – 1.5 mm is recommended for most applications.
  • Use a fluid pressure of 0.5 - 1.0 bar and an air pressure of typically 1.5 - 3.0 bar, depending on the fineness of the spray required. HVLP spray systems are recommended.
  • Ideally, apply to substrates pre-heated to 40 - 50ºC.

Dilution:

  • Dilute Cilbond® R-7296W with de-ionised or distilled water and stir during dilution. It is also possible to dilute with water/alcohol blends containing <10% ethyl alcohol.
  • Drying:
  • Thorough drying is essential before applying the cover-coat, especially on grit-blasted metals.
  • It is recommended that Cilbond® R-7296W be applied to pre-heated metal parts (40 - 50°C), or the metals are heated after coating in an oven at 50 - 60°C. This ensures rapid and thorough drying and maximum environmental resistance.
  • If applying to unheated metal parts, ensure the ambient temperature is above 25°C and humidity is less than 70%. Allow films to dry for at least 60 minutes.

Film Thickness:

  • The above recommendations should give a suitable dry coating thickness of 10–15 microns.
  • For maximum environmental resistance, coating thickness should be >15 microns.
  • For severe environments, it is essential that coatings are of even thickness, fully wetted, and fully coalesced. Coatings should also be void-free and completely dry.

Properties

Appearance
Dark grey liquid
Typical Physical Properties
ValueUnitsTest Method / Conditions
Total Solids24wt%-
Viscosity (at 26°C)35secondsDIN 4 Cup
Specific Gravity (at 26°C)1.1--
Recommended Dry Film Thickness10 - 15microns-
Bonding Temperature Range130 - 220°C-
pH8--
Minimum Film Forming Temperaturemin. 20°C-
Volatile Organic Compound Contentmax. 5%-
Typical Coverage16 - 24m²/Litre-

Packaging & Availability

Regional Availability
  • Asia Pacific
  • Europe
  • North America

Storage & Handling

Shelf Life
12 months
Storage Conditions
  • This Cilbond grade has been formulated and manufactured using multiple sources of approved raw materials.
  • Cilbond® R-7296W 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 the material slowly and then stir with a high shear to form a smooth and homogenous mix.
  • If stored above 40°C, then cool the material as soon as possible, re-check that the product is within original specifications, and use within 1 month.
  • Cilbond® R-7296W is free from lead and virtually free from solvent.
  • It is supplied in 10 litre, 25 litre containers, and 200 litre stirrer drums. 250ml trial samples are also available upon request.