GE - RTV12A Base Silicone, Two-Part Clear, Low Viscosity, Primerless

RTV12 Low Viscosity, Repairable,
Two-Component Silicone Potting System

(RTV12C Curing Agent, required, sold seperatly)

(SS4004, SS4044 or SS4179 primers may improve RTV12 rubber adhesion to substrates showing borderline adhesion)

Product Description

RTV12 is a clear two-component, low viscosity potting compound that cures at room temperature to a soft pliable rubber. RTV12 will cure in deep sections without additional heating or moisture. RTV12 has been designed to achieve primerless adhesion to many substrates, including metals, plastics and ceramics, typical of those found in electronic assemblies.

RTV12C curing agent is mixed with RTV12A base compound producing a clear cured rubber to provide see-through properties in greater thicknesses. RTV12 allows visual observation of the components during pouring and easy identification, repair, and replacement of components when necessary.

RTV12 is suggested for evaluation as a potting material to provide environmental protection to electrical and electronic assemblies. When cured, the soft, rubbery property of RTV12 rubber cushions against mechanical shock and vibration. The excellent electrical properties make it a candidate material for both high and low voltage electrical assemblies.

Key Performance Properties

Clear to allow easy identification of components
Primerless adhesion to many metals and plastics
Repairable? Room temperature cure
Excellent electrical properties
Can be used with materials that cause cure inhibition with other RTV's
Specially formulated to minimize copper corrosion
Easily flows in and around complex electronic assemblies
Easy to use on production line may be mixed by hand or machine

Typical Product Data:

Uncured Properties As Supplied

RTV12A Base Compound:

Color: Clear: Slight Haze
Viscosity, cps: 1300
Specific Gravity: 1.00
Solvent: None
Shelf life, months: 6

RTV12C Curing Agent:

Color: Clear
Viscosity, cps: 15
Specific Gravity: 0.84
Solvent: Mineral Spirits
Shelf life, months: 6

Uncured Properties Curing Agent Added: RTV12A with RTV12C

Base to Curing Agent Ratio by Weight: 20:1
Catalyzed Viscosity @ 5 Min.: 1500
Catalyzed Brookfield Viscosity @ 30 Min.: 3200
Catalyzed Brookfield Viscosity @ 60 Min.: Gel
Gel Time, minutes @ 25C (77F): 100
Gel Time, minutes @ 85C (185F): 30
Durometer, Shore A @ 3 days: 18
Specific Gravity: 1.00

Cured Properties:

ASTM Sheet 1.9 mm (0.075 in.)thickness: 24 hrs Press + 48 hrs @ 25°C (77°F) 50% R.H.
Electrical:

Dielectric Strength, volts/mil: 400
Dielectric Constant, 1 kHz: 3.0
Dissipation Factor, 1 kHz: 0.001
Volume Resistivity, ohm-cm: 1 x 1013

Thermal:

Useful Temperature Range: -75°F to 400°F (-60°C to 204°C)

Specifications:

Typical product data values should not be used as specifications. Assistance and specifications are available by contacting GE Silicones at 800/255-8886.

Instructions for Use:

Mixing Instructions

RTV12C curing agent is non-separating. However, shaking is suggested to insure uniformity.

RTV12A base compound is mixed with RTV12C curing agent in a 20:1 ratio by weight. The base compound and curing agent must be weighed and measured to insure the proper 20:1 blend ratio. Using less curing agent will result in a softer rubber after cure.

Thoroughly mix the RTV and the curing agent using clean tools. Scrape the side and bottom of the container several times to produce a homogeneous mixture. When using power mixers avoid excessive speeds which could entrap large amounts of air or cause overheating of the silicone and resultant shortening of work life.

Deaeration

Air entrapped during mixing must be removed to eliminate voids in the cured product. Expose the mixed material to a vacuum of about 25 mm (29 inches) of mercury. The material will expand, crest and recede to about the original level as the bubbles break. Degassing is usually complete about two minutes after frothing ceases. When using the RTV for potting, deaeration may be necessary after pouring to avoid trapping air in complex assemblies.

Automatic equipment designed to meter, mix, deaerate, and dispense two-component RTV silicone rubber compounds will add convenience to continuous or large volume operations. For additional information, refer to GE Silicones publication CDS1758.

Curing

RTV12A mixed with RTV12C curing agent will gel in approximately two hours at room temperature. This permits handling a potted container without spilling the contents (even if inverted). However, complete cure requires 72 hours at room temperature.

More rapid cure may be realized by using mild heat. For example, cure may be obtained in one hour at 85°C (185°F). Laboratory curing tests should be run prior to production to determine the appropriate cure for a specific potted assembly. Longer cure times may be required for large and deep section assemblies.

Bonding

RTV12 offers primerless adhesion to many components, wire insulation and potting containers used in electrical and electronic assemblies. To achieve optimum adhesion, all components must be clean and dry prior to potting. A laboratory test is recommended to confirm adhesion prior to production use. SS4004, SS4044 or SS4179 primers may improve RTV12 rubber adhesion to substrates showing borderline adhesion. Complete information and usage instructions for primers is available upon request. Bonding to components is desirable to minimize electrical leakage, particularly in humid environments.

Handling and Safety

Material Safety Data Sheets are available upon request from GE Silicones. Similar information for solvents and other chemicals used with GE products should be obtained from your suppliers. When solvents are used, proper safety precautions must be observed.

WARNING: RTV12C curing agent will cause severe skin irritation and eye burns. Keep out of reach of children. Avoid contact with skin, eyes and clothing. If spilled on clothing, remove clothing at once and wash same before re-use. In case of contact, immediately flush skin or eyes with water for 15 minutes, and consult a physician.

RTV12C curing agent contains mineral spirits and is classified as flammable. Keep away from heat, sparks and flame.

Storage and Warranty Period

This product may be shipped at ambient temperatures up to 110°F for up to 7 days maximum. The warranty period is six months from date of shipment from GE Silicones if stored in the original unopened container at 25°C (77°F) or below. Keep curing agent container tightly closed. Avoid all unnecessary exposure to air and moisture such exposure may reduce the catalyst activity substantially and may adversely affect the cure rate and cured properties.

LEGAL DISCLAIMER

THE MATERIALS, PRODUCTS AND SERVICES OF GE SILICONES, GE BAYER SILICONES, GE TOSHIBA SILICONES, THEIR SUBSIDIARIES OR AFFILIATES (THE ?SUPPLIER?), ARE SOLD SUBJECT TO THE SUPPLIER?S STANDARD CONDITIONS OF SALE, WHICH ARE INCLUDED IN APPLICABLE SALES AGREEMENTS, PRINTED ON THE BACK OF ACKNOWLEDGMENTS AND INVOICES, OR AVAILABLE UPON REQUEST. ALTHOUGH THE INFORMATION, RECOMMENDATIONS OR ADVICE CONTAINED HEREIN IS GIVEN IN GOOD FAITH, SUPPLIER MAKES NO WARRANTY OR GUARANTEE, EXPRESS OR IMPLIED, (I) THAT THE RESULTS DESCRIBED HEREIN WILL BE OBTAINED UNDER END-USE CONDITIONS, OR (II) AS TO THE EFFECTIVENESS OR SAFETY OF ANY DESIGN INCORPORATING SUPPLIER?S MATERIALS, PRODUCTS, SERVICES, RECOMMENDATIONS OR ADVICE. NOTHING IN THIS OR ANY OTHER DOCUMENT SHALL ALTER, VARY, SUPERSEDE OR OPERATE AS A WAIVER OF ANY OF THE SUPPLIER?S STANDARD CONDITIONS OF SALE.

Each user bears the full responsibility for making its own determination as to the suitability of Supplier?s materials, products, services, recommendations or advice for its own particular purpose. Each user must identify and perform tests and analyses sufficient to assure it that its finished parts will be safe and suitable for use under end-use conditions. Because actual use of products by the user is beyond the control of Supplier, such use is within the exclusive responsibility of the user, and Supplier cannot be held responsible for any loss incurred through incorrect or faulty use of the products. Further, no statement contained herein concerning a possible or suggested use of any material, product, service or design is intended or should be construed to grant any license under any patent or other intellectual property right of Supplier or any of its subsidiaries or affiliated companies, or as a recommendation for the use of such material, product, service or design in the infringement of any patent or other intellectual property right.

Material Safety Data Sheet (MSDS)