Miller-Stephenson Chemical MS-470C Urethane Conformal Coatings

Miller-Stephenson Chemical MS-470C Urethane Conformal Coatings is a non-flammable, solvent-based, one-component polyurethane conformal coating provided in the convenience of aerosol. Our coating provides excellent electrical and barrier properties in a thinfilm applications on components and PCBs. When fully cured, the applied urethane coating exhibits superior toughness, abrasion resistance, and excellent moisture and chemical resistance. MS-470C will maintain its properties even after long exposure to the elements with minimal color change.

Product Type: Conformal Coating, Solventborne Coating

Features: Abrasion Resistant, Chemical Resistant, Good Toughness, Moisture Resistant, Solvent Resistant

Application Method: Brush, Dip Coating, Spray

Chemical Family: Polyurethanes (PU)

Technical Data Sheet

Knowde Enhanced TDS

Identification & Functionality

Chemical Family

Features & Benefits

Benefits
  • Superior toughness and abrasion resistance
  • Reworkable and room temperature cure
  • Solvent and discoloration resistant
  • Fluorescent under UV light
  • No cracking or crazing with vibration
  • Easier to re-work than epoxy-based coatings
Urethane Conformal Coatings

Superior Toughness, Abrasion Resistance, and Chemical Stability

Polyurethane coatings are available as either aerosol or bulk formulations. Both formulations provide excellent humidity resistance and far greater chemical resistance than Acrylic coatings. These Spray Conformal Coating are Single component Polyurethanes, while easy to apply, enjoy long pot life but sometimes require very lengthy cure cycles to achieve full or optimum cure. The cure cycle can be accelerated by the application of heat typically reducing cure times to less than 4-5 hours at 50% humidity.

Cleanliness of the substrate is of extreme importance for the successful application of a conformal coating. Surfaces must be free of moisture, dirt, wax, grease, flux residues and all other contaminants. Contamination under the coating could cause problems that may lead to assembly failures. MS-470C will cover 8.6 square feet at a 2-mil thickness per 14-oz. aerosol can.  MS-472C, the bulk liquid version of the product, is available in quarts and gallons for dip, brush, or spray applications and will cover 120 square feet per gallon at a 2-mil thickness. Printed circuit boards or electronics covered with urethane coating are repairable.  Simply heat the coating with a soldering iron to remove the components.

Urethane Conformal Coatings provide a barrier to air-borne contaminants from the operating environment, such as salt-spray, thus preventing corrosion.  Some typical application examples include high-reliability defense, automotive and aerospace, where coatings are used to protect against various combinations of moisture, aggressive chemicals and vapors, salt sprays, large temperature variations, mechanical vibration, and even organic attack (e.g. fungus). The protective nature of conformal coatings also means that they not only protect, but also serve to enhance product reliability and thereby reduce the potential cost and damaging effects of early field failures.

Applications & Uses

Application Method
Cure Method
Applications

Application should be done in a well-ventilated area. Proper safety
equipment and chemical resistant gloves are strongly
recommended

  1. Hold can 6 – 8 inches away from the assembly and apply a
    medium-light coating. Coating must be applied wet and
    allowed to dry on the surface of the assembly.
  2. Allow coating to dry for 30-35 minutes at room temperature.
  3. Apply 1-2 additional medium wet coats with 30-35 minutes
    between each.
  4.  A total cured film thickness of 2 ± 1mil is recommended.
  5.  Once spraying is complete, immediately invert can and purge
    the valve and actuator. This will prevent clogging and
    premature valve failure.
  6. Drying and curing of the coating depends upon evaporation of
    the solvent and subsequent reaction of the polymer with
    moisture in the air at elevated or room temperatures.
Applications

Allow 48 hours minimum to reach room temperature before using cans stored or received during cold weather.

Post Application: Air dry for 30 minutes. Repeat up to 2-3 coats. The recommended cure schedule is 2 hours at 140°F/60°C and a relative humidity of 30% to 50%.  If the humidity level is less than 30%, place an open container of distilled water in the oven and allow to equilibrate.  The alternate cure, at room temperature and a relative humidity of 30% to 50%, will be tack free in one to four hours, semi-hard in one day, and fully cured in seven days.

Properties

Physical Form
Appearance
No blistering, wrinkling, cracking, or peeling of film, after thermal shock and moisture resistance testing.
Electrical Properties
ValueUnitsTest Method / Conditions
Volume Resistivity2.0 x 1013ohm-cm
Dielectric Strength1200volts/mil
Dielectric Constant(105 Hz at 25°C)4.2
Dissipation Factor(105 Hz at 25°C )0.01
Cured Properties
ValueUnitsTest Method / Conditions
Operating Temperature-67/-55 to 230/110°F/°C
FlexibilityNo cracking of film over a 1/8" diameter mandrel.
Fungus ResistanceNon-nutrient per ASTM G21
FluorescentUnder ultraviolet light.

Technical Details & Test Data

Aerosol Preparation and Room Conditions
  1. 1. Important do not shake can prior to usage. Allow can to warm
    up to room temperature prior to use. Failure to do so will affect
    sprayability and can affect coating performance.
  2.  MS-470C should be applied at room temperature.
  3. MS-470C should not be applied where relative humidity is
    below 30% or above 70%. Ideal room conditions are the
    following: 50-60% humidity and 70–80 °F.
  4. If reusing a previous sprayed aerosol can, invert can to clean
    valve and perform several test sprays to inspect spray pattern
    and fluid delivery. If both appear suitable continue with the
    application process.
Cure Schedules

Final film properties can be achieved by either heat acceleration or
room temperature.

  1. Heat Accelerated: Allow board to air dry for 30-45 minutes
    prior to placement into the oven.
  2. Oven curing must be done at 60-68°C (140-154 °F) at a
    humidity level of 40-55%. This can be achieved by placing a
    pan of distilled water in the cure oven one hour before you
    place the coated assemblies inside.
    NOTE: Failure to provide humidity during the heat accelerated
    curing program will affect final film performance.
  3. Oven cure the coated assemblies for ~ 2hrs.
  4. Allow an additional 1 – 2 days at room temperature and 45-
    55% humidity for final film properties to be developed once
    removed from the oven.
  5.  Room Temperature / Air Cure: Allow to cure for 7 days at room
    70-80 °F at a relative humidity of 55-65%.
  6. Coatings will typically be tack-free in 1 – 4 hours depending
    on the number coats, coating thickness, and room conditions.
Clean-up

Uncured MS-470C can be removed with aromatic, ketones, or glycol ethers. Removal of cured MS-470C will require Miller- Stephenson MS-114D or MS-115 Conformal Coating Stripper.

Packaging & Availability

Sizes Available

14 oz Aerosol

Storage & Handling

Storage

Aerosol Cans should be kept at 70-77°F and away from direct contact with sunlight.

Limitation Of Liability And Remedies

Manufacturer warrants that, at the time of sale by the Manufacturer, this product is free from defect in material and manufacture. If the product is proved to be defective, the exclusive remedy, at Manufacturer’s option, shall be refund of the purchase price or replacement of the defective product, provided written notice of the defect is given no later than 210 days
after sale by the Manufacturer. Manufacturer shall not otherwise be liable for loss or damages whether direct, indirect, incidental or consequential, regardless of the legal theory asserted, including negligence and strict liability. Manufacturer expressly disclaims all implied warranties, including the implied warranty of merchantability and the implied warranty of fitness for a particular purpose. There are no warranties which extend beyond the description on the face hereof