ENTEK® CU-56
Tarnish and corrosion inhibitor for copper and brass
Entek® CU-56 is a liquid material added to rinse water to prevent tarnishing, staining, green salt formation, pit
corrosion, finger marking and spotting-out of copper and brass. Prior to using this product, refer to "OPERATING
CONDITIONS", "CONTROL", and "PRECAUTIONARY INFORMATION" sections for proper handling and usage
procedures. READ ENTIRE TECHNICAL DATA SHEET BEFORE USING THIS PRODUCT.
Entek CU-56 replaces water-dip lacquers and requires no additional processing steps. Alkaline cleaning (soak or
electrolytic) removes the Entek CU-56 coating prior to subsequent plating processing. It is rapid and the coating
does not interfere with painting or soldering. The presence of the coating improves the adhesion of lacquers and
enamels and improves solderability.
NOTE: Some clear epoxies may be darkened by the Entek CU-56 film.
Entek CU-56 is ideal for use in the final rinse tank following copper or brass plating because it will preserve
the freshly-plated appearance for weeks even under high humidity storage conditions. On mill products, Entek
CU-56 solutions may be used to treat copper and brass strip prior to coiling to prevent corrosion in storage due to
moisture trapped in the tightly wound coils.
The coating produced by Entek CU-56 is completely invisible and has many times the corrosion resistance of
bare copper and brass. It will withstand 200 hours exposure to tropical humidity conditions without discoloration
whereas bare copper or brass will start to corrode after one hour. However, Entek CU-56 is not recommended
for protection against outdoor exposure. The primary function of the Entek CU-56 coating is to prevent tarnishing, corrosion, and spotting-out of copper and brass during storage.
Entek CU-56 does not contain chromates and is very economical to use. One gallon of operating solution
will treat approximately 500 ft.2 (47 m2) of metal surface.
HOW TO USE ENTEK CU-56
OPERATING CONDITIONS
Concentration
1% by volume Entek CU-56 in water
Temperature
Room Temperature to 140°F. (60°C.)
Time
5 to 45 seconds
OPERATION
Entek CU-56 is added to water at a concentration of 1% by volume. The work should be rinsed in the Entek
CU-56 solution for a minimum of 30 seconds at room temperature and then dried. Rinsing in water after rinsing in
Entek CU-56 will lessen the degree of protection obtained. To aid in drying, the solution may be heated to 140°F.
(60°C.) in which case the immersion time may be reduced to 5 to 10 seconds. Where it is desired to operate the
final rinse at temperatures above 140°F. (60°C.), Entek CU-55, which reacts more slowly with copper and brass,
© 2000, Enthone-OMI, Inc.
Entek® CU-56
Technical Data Sheet
Page 2 of 4
should be sued. Literature on Entek CU-55 is available from Enthone-OMI upon request. Above 140°F. (60°C.)
Entek CU-56 may form a visible film on the metal surface.
OPERATION (CONT)
Work entering the Entek CU-56 rinse should be clean, wet and free of water-breaks. This is usually the case
after plating, pickling or other wet processing. the solution has no cleaning ability of its own and the protective
Entek CU-56 coating will not form on unclean surfaces.
For maximum effectiveness, work entering the Entek CU-56 rinse should have an alkaline rather than an acid
surface condition. For example, after bright dipping of copper or brass in a nitric-sulfuric solution, the work should
be neutralized by dipping in a soda ash or sodium hydroxide solution, rinsed thoroughly, and then rinsed in Entek
CU-56.
EQUIPMENT
Entek CU-56 solutions should be contained in stainless steel, fiberglass, plastic or rubber-lined steel tanks,
polyethylene or ceramic crocks. Plain steel tanks will tend to rust and interfere with the application of the protective film. For heating, use stainless steel, copper or copper-plated steel steam coils, or Platecoils. Ventilation is
recommended to keep vapors below recommended TLV level.
CONTROL
The simplest control is to observe the work coming out of the Entek CU-56 solution. Failure of the solution to
"break" cleanly from the metal surface will indicate that the concentration of Entek CU-56 is low. An addition of
1/2 percent by volume of Entek CU-56 should be made at this point.
A more accurate, analytical method is available from Enthone-OMI upon request.
WASTE TREATMENT
Entek CU-56 solutions consist of organic chemicals dissolved in a methanol-water solution and may contain
metals processed through the operating solution. Consult local agencies regarding waste effluent regulations.
PRECAUTIONARY INFORMATION
DANGER!
FLAMMABLE, CONTAINS METHYL ALCOHOL
FLAMMABLE, TOXIC: Keep away from heat, sparks, flames and all ignition sources. Vapors may travel
to distant points of ignition sources. Inhalation may cause dizziness, drowsiness, vision problems and
irritation of respiratory tract. Ingestion may cause nausea, vomiting, vision problems, blindness,
dizziness, coma and death. Prolonged contact may cause reddening and defatting of the skin, absorption
of harmful amounts of methyl alcohol. Do not get in eyes, on skin, or on clothing. Do not inhale or take
internally.
FIRST AID: In case of contact, immediately flush skin or eyes with plenty of water for at least 15 minutes;
hold eye-lids apart to ensure flushing of entire surface, seek immediate medical attention. If ingested,
drink large amounts of water and INDUCE VOMITING, seek immediate medical attention. In case of
inhalation, remove person from area. If breathing has stopped, resuscitate and administer oxygen if
necessary, seek immediate medical attention. Remove and wash contaminated clothing.
HANDLING INFORMATION: Always wear goggles, face-shield, rubber gloves, apron and boots, respirator
and protective clothing when handling. Use with adequate ventilation. Avoid contact with alkali metals,
acids or any other foreign material. Avoid contamination from any source. Exhaust ventilation is
Entek® CU-56
Technical Data Sheet
Page 3 of 4
recommended to remove mist or vapors that may be generated during make-up and operation. Wash
thoroughly after handling.
CONTAINER INFORMATION: Store in a cool, dry, well-ventilated area. Keep out of sun and away from
heat, combustibles and ignition sources. Loosen closure cautiously, when opening. Do not reuse
container, wash thoroughly before disposal. Improper disposal or reuse of container may be dangerous
and illegal.
REFER TO MSDS FOR FURTHER SAFETY AND HANDLING INFORMATION.
Issued: 07/17/00
Spsds: 10/12/90
Entek® CU-56
Technical Data Sheet
Page 4 of 4
MATERIAL SAFETY DATA SHEETS
For more detailed information on the toxicological properties of the products described herein, reference can be
made to the Material Safety Data Sheet (MSDS) for each product. If you do not have the proper MSDS, it can be
requested from: Enthone Inc., attention: Regulatory Affairs Department, 350 Frontage Road, West Haven, CT
06516. For emergency assistance call CHEMTREC (800) 424-9300.
WARRANTY AND DISCLAIMER
The information presented herein is to the best of our knowledge true and accurate and all recommendations and
suggestions appearing in this bulletin covering the use of our products are based upon information believed to be
reliable. However, since the conditions of use are beyond our control, this information is given on the express
condition and agreement that Enthone Inc. will not be liable to any person in contract, tort (including negligence),
strict liability or otherwise for any claims, damages or losses whatsoever. Nothing herein shall be deemed a
recommendation to use any product or process in violation of any existing patent rights and no warranties,
expressed or implied, are made regarding the information, product, processes, recommendations, description and
safety notations contained herein. The above includes proprietary information of Enthone Inc. and is furnished to
you for your use solely on products or processes supplied by us to you.
Enthone Inc. (Canada) MATERIAL SAFETY DATA SHEETS
For detailed information on the toxicological properties of the products described herein, reference can be made
to the Material Safety Data Sheet (MSDS) for each product. If you do not have a current MSDS, it can be requested from the W.H.M.I.S. coordinator, Enthone Inc. (Canada), 121 Watline Avenue, Mississauga, Ontario,
L4Z-1P2. For emergency assistance regarding accidents with this product resulting in container rupture, spills,
poisoning, bodily injury or threats to health call: CHEMTREC (800) 424-9300.
Enthone Inc. (Canada) WARRANTY AND DISCLAIMER
The information presented herein is to the best of our knowledge true and accurate and all recommendations and
suggestions appearing in this bulletin covering the use of our products are based upon information believed to be
reliable. However, since the conditions of use are beyond our control, this information is given on the express
condition and agreement that Enthone Inc. (Canada) will not be liable to any person in contract, tort (including
negligence), strict liability or otherwise for any claims, damages or losses whatsoever. Nothing herein shall be
deemed a recommendation to use any product or process in violation of any existing patent rights and no warranties, expressed or implied, are made regarding the information, product, processes, recommendations, description and safety notations contained herein. The above includes proprietary information of Enthone Inc.
(Canada) and is furnished to you for your use solely on products or processes supplied by us to you.
CUSTOMER ORDER CENTERS
UNITED STATES
West Haven, Connecticut
Performance Coatings
(800) 496-8326
Precious Metal Products
(800) 560-7214
Fax (203) 933-0249
ctchemorders@cooksonelectronics.com
PWB Chemistry
Londonderry, New Hampshire
CANADA
Mississauga, Ontario
Fax (905) 507-9943
Pointe Claire, Quebec
Fax (514) 426-1453
MEXICO
www.cooksonelectronics.com
03 May 04
Mexico, D.F.
Fax (011-52-5) 567-6326
(800) 877-9871
Fax (603) 645-4402
(800) 387-3766; (905) 507-9949
(514) 426-1451
(011-52-55) 5078-3904
® Registered Trademark of Enthone Inc. ™ Trademark of Enthone Inc.
[Enthone Inc. (Canada) Inc. is the registered user in Canada under license from Enthone Inc. (USA)]