Master Bond Polymer System EP21TCHT-1 is a two component, thermally conductive, heat resistant, epoxy compound formulated to cure at ambient temperatures or more rapidly at elevated temperatures, with a 100/60 mix ratio by weight. EP21TCHT-1 passes NASA outgassing tests. It develops a high bonding strength of 2200 psi at ambient temperatures and retains significant strength even upon exposures to temperatures as high as 400°F . The bonds produced are both tough and durable as well as resistant to thermal cycling and many chemicals including water, fuels and most organic solvents. It has a service temperature range of 4°K up to 400°F . It adheres well to metals, glass, ceramics, wood, vulcanized rubbers and many plastics. The hardened adhesive exhibits high thermal conductivity and yet is a superior electrical insulator. The thermal expansion coefficient is remarkably low. Master Bond Polymer System EP21TCHT-1 is widely used in electronics, electrical, construction, metalworking, appliance, automotive and chemical industries. As a NASA qualified system, it is ideal for high vacuum type applications, particularly those where elevated temperature cures are not possible.

产品优点 ：

•  Convenient mixing: non-critical 100/60 mix ratio by weight.

•  Easy application: contact pressure only required for cure; 100% reactive compound does not contain any solvents or diluents.

•  Versatile cure schedules: ambient temperature cures or fast elevated temperature cures as required.

•  Durable; excellent thermal shock and chemical resistance.

•  High thermal conductivity; superior electrical insulation.

•  NASA qualified; can be used in high vacuum applications.

•  High temperature resistant; serviceable up to 400°F .

产品属性 :

•  Mixing ratio, wt. part A/part B ............................................................................................ 100/60

•  Viscosity of mixed compound 75°F ............................................................................... light paste

•  Working life after mixing, 75°F ;

100 gram batch, minutes ................................................................................................ 45

•  Cure schedule, ambient temperatures , hours ....................................................................... 18-24
200°F ............................................................................................................................ 1-2

•  Tensile shear, aluminum/aluminum, @ 75°F ............................................ ....................................2200

•  After 30 days water immersion, 75°F , psi .............................................................................. 2080

•  At 400°F after 1 hour exposure to 400°F , psi ........................................................................... 650

•  Hardness, Shore D ................................................................................................................. >80

•  Thermal conductivity, BTU's in/ft2 ?hr? °F ................................................................................... 10

•  Coefficient of thermal expansion, in/in x 10 -6 °C ....................................................................... 18-20

•  Dielectric strength, volts/mil. (Kv/mm) .............................................................................. 420/16.4

•  Service temperature range, °F ................................................................................. 4°K to + 400°F

•  Shelf life at 75°F , in unopened containers, months ................................................................. 1 year

•  Parts A and B available in pint, quart, 1(one) gallon and 5(five) gallon containers.

Preparation of Adhesive and Bonding Surfaces

Master Bond Polymer Adhesive EP21TCHT-1 is prepared by thoroughly mixing part A with part B in a 100/60 mix ratio, weight or volume. Mixing should be done slowly to avoid entrapping air. Color coding makes mixing easy: part A is colored off white, part B is colored off white. The working life of a mixed 100 gram batch is approximately 45 minutes. It can be substantially lengthened by using shallower mixing vessels or mixing smaller size batches. All bonding surfaces should be carefully cleaned, degreased and dried for obtaining maximum bond strengths. Also when bonding to metal surfaces, chemical etching should be employed when the bonded joints are to exhibit optimal environmental durability. Non-porous surfaces should be roughened with sandpaper or emery paper for hard materials.

Adhesive Application

Master Bond Polymer Adhesive EP21TCHT-1 can be conveniently applied with a spatula, knife, or trowel. It is prepared for use by mixing the two components in the required 100/60 mix ratio by weight. Enough mixed adhesive should be applied to obtain a final adhesive bond line thickness of 2-4 mils thick. Porous surfaces may require somewhat more adhesive to fill the voids than non-porous ones. EP21TCHT-1 can be cured at ambient or more quickly at elevated temperatures. Excess adhesive should be removed with solvents such as acetone, xylene or alcohol before it hardens.

Cure

Master Bond Polymer Adhesive EP21TCHT-1 can be cured at room temperature or at elevated temperatures as desired. At room temperature Master Bond Polymer Adhesive EP21TCHT-1 cures in 18-24 hours at room temperature. Faster cures can be realized at elevated temperatures, e.g. 2 hours at 200°F .

Handling and Storage

All epoxies should be used in a well ventilated area, skin contact should be minimized, the use of rubber gloves is recommended. EP21TCHT-1 adhesive employs a low toxicity hardener. To remove resin or hardener from skin, use a mild solvent, then wash with soap and water. If material enters the eyes, flood with water and consult a physician. Optimum storage is at or below 75°F in closed containers. No special storage conditions are necessary. Containers should however be kept closed when not in use to avoid contamination. Cleanup of spills and equipment is readily achieved with acetone, xylene, or alcohol employing proper precautions of ventilation and flammability.