Cilbond® R-7296W

Identification

GBU

EA

Categories

Technologies → Adhesives & Sealants

Applications

Segment

Rubber to Metal

Applications & Uses

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.

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.

Packaging & Availability

Regional Availability

• Asia Pacific
• Europe
• North America

Physical Properties

Appearance

Dark grey liquid

Properties

Typical Physical Properties

	Value	Units	Test Method / Conditions
Bonding Temperature Range	130 - 220	°C	-
Minimum Film Forming Temperature	min. 20	°C	-
Recommended Dry Film Thickness	10 - 15	microns	-
Specific Gravity (at 26°C)	1.1	-	-
Total Solids	24	Wt(%)	-
Typical Coverage	16 - 24	m²/L	-
Viscosity (at 26°C)	35	seconds	DIN 4 Cup
Volatile Organic Compound Content	max. 5	%	-
pH	8	-	-

Typical Properties

	Value	Units	Test Method / Conditions
Storage Temperature	5 - 30	°C	-

Appearance

Dark grey liquid

Storage & Handling

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.

Shelf Life

12 months