Single-component solvent-free elastic silicone rubber conformal coating

JOMS 521 is a one-component, none-solvent type conformal coating ,based on silicone. It cures on exposure by moisture to form an elastic silicone rubber film.
JOMS 521 has excellent corrosion-free adhesion to metals, including copper, plastics, ceramics, glass, etc, without the use of primers.
Excellent high and low temperature resistance: from –60℃~ 250℃ .
Stably under working temperature 200℃ for long term
Excellent weather ability, water andchemical resistance
Excellent electrical insulation properties.
Simple and easy-to-use one-component system.

product details

Single-component solvent-free elastic silicone rubber conformal coating

FEATURES

JOMS 521 is a one-component, none-solvent type conformal coating ,based on silicone. It cures on exposure by moisture to form an elastic silicone rubber film.
JOMS 521 has excellent corrosion-free adhesion to metals, including copper, plastics, ceramics, glass, etc, without the use of primers.
Excellent high and low temperature resistance: from –60℃~250℃ .
Stably under working temperature 200℃ for long term
Excellent weather ability, water andchemical resistance
Excellent electrical insulation properties.
Simple and easy-to-use one-component system.

Type

one-part, moisture-cure,

none-Solvent type; low viscosity

Physical Form

cure to flexible elastomers as film

Special Properties

Room-temperature; resist humidity and other harsh environments;

Easily removable;

good dielectric properties; self-priming adhesion;

prevent PCB board suffering humid and corrosive

Potential Uses

Household control module; Impregnated transformers; Inductive protection;

Tough and flexible PCB coating;

LED lights’ surface coating;

TYPICAL PROPERTIES

TYPICAL UNCURED PROPERTIES
	JOMS 521
Viscosity, mPa.s	900
Appearance	Clear
Solide content	100%
Specific Gravity（g/cm3）, GB/T 15223-1994	1.00±0.02
25℃Tack-free Time(min), GB/T13477-2002	10-20
TYPICAL CURED PROPERTIES (7 DAYS @ 25℃/55％RH)
Hardness, Shore A, GB/T 531-2008	20
Tensile strength (Mpa), GB/T 528-2009	0.4
Elongation(%), GB/T 528-2009	200
Adhesive strength (Mpa), GB/T 7124-2008	0.25
ELECTRICAL PROPERTIES (CURED)
Dielectric strength (kv/mm), GB/T 1695-2005	25
Dielectric constant (@1MHz), GB/T 1693-2007	2.9
Dielectric loss (@1MHz), GB/T 1693-2007	0.009
Volume resistivity (Ω·cm), GB/T 1692-92	1×1014
Thermal conductivity [W/(m·K)], GB/T 10297-1998	0.22

The Physical property above was test after cured 7days. Shear test of base material is iron tablets.

USE

Clean the surface thoroughly,keep dry and loose debris 。Clean with a solvent.
Sprayingwith a dispenser. Thinner dosage recommendations for 30~50%. Diluent recommends the use of Heptane \toluene and petroleum ether, do not use solvent such as alcohols, ketones.
1 L/can

Dip-coatingprocess.dip the PCB into the glue, and stay for about 10seconds to avoid bubbles.

How to apply

Apply a bead of JOMS 521 Adhesive/Sealant (see Handling Precautions) to one of the prepared surfaces.

On exposure to moisture, the freshly applied material will “skin-over” in about 20-30 minutes at room temperature and 50% relative humidity. Any tooling should be completed before this skin forms. The surface is easily tooled with a spatula. The adhesive/sealant will be tack-free in approximately 30 minutes.

Cure time

In 24 hours (at room temperature and 50% relative humidity) JOMS 521 Adhesive/Sealant will cure to a depth of about 3-4mm. If deeper sections, especially when access to atmospheric moisture is restricted, will take longer to cure completely.

Cure time is extended at lower humidity levels. Before handling and packaging bonded components, users are advised to wait a

sufficiently long time to ensure that the integrity of the adhesive seal is not affected. This will depend on many factors and should be determined by the user for each specific application.

To reach stable property, it’s better to rise the temperature step by step, for example, after cured 7 days, heat the sealant on 150℃ for 5 hours, then 200℃ for 4hours, 230℃ for 4hours, 250℃ for 3 hours ,and 280℃ for 2hours.

USABLE LIFE AND STORAGE

When stored at or below 300C (860 F) inthe original unopened containers, this product has a usable life of 12 months from the date of production.

PURCHASE CODE

√、JOMS 521 conformal coating,

1 L/can

LIMITATIONS

Adhesion may be less successful on low-energy plastics such as Polyethylene, Polypropylene and PTFE. Users should do preliminary tests in each specific application to ensure satisfactory results.