TYPE SK-9

Lens Bond Type SK-9 is a single component, modified Acrylate/Methacrylate Photopolymer. This low viscosity liquid polymer is easy to apply and quick to pre-cure. Lens Bond Type SK-9 cures by exposure to long wave ultraviolet light (365nm).

Its high wetting and low shrinkage combine to give a superior bond. Lens Bond Type SK-9 is a very low viscosity liquid which practically eliminates air bubble problems. Lens Bond Type SK-9shows extremely high adhesion to many types of plastics which are usually problematic to bond. Lens Bond Optical Cement Type SK-9 permits the user to pre-cure the elements in 3-5 seconds using a 4 to 15 watt fluorescent UV light at 1" from the upper element. Full-cure is attained in 1 hour at 1".

12675

Lens Bond Type SK-9
1oz bottle

1oz

12676

Lens Bond Type SK-9

500gm

12675-40

Lens Bond Type SK-9 (40 cps)
bottle

1oz

12675-60

Lens Bond Type SK-9 (60 cps)
bottle

1oz

Approximate Curing Times

Pre-Cure Full-Cure
Room temperature 22캜(72캟) using longwave radiation (365nm) approximately 1" above the element. Room temperature 22캜(72캟) using longwave radiation approximately 1" above the element.
3-5 seconds 1 hour
Note: Some plastics transmit very little light at 365nm; however, due to Type SK-9's sensitivity, it will cure, but times might be extended. Always test for cure speeds prior to production.
For more information on our ultraviolet curing lamps please see our cementing department supply section of our web site.

Instructions For Use

Preparation of Elements: Other than normal cleaning procedures, no special preparation is required. The best final cleaner is reagent grade or C.P. Acetone.

Preparation of Cement: There is no mixing or measuring with Type SK-9. However, it is advantageous to have the elements on a white background during pre-cure and full-cure cycles. If this cannot be done due to a use of a centering device, witness pieces should be tried to ascertain the repeatable pre-cure time. The user should always check with the glass or plastics manufacturer for the transmission characteristics at 365nm of the materials that they wish to bond. Transmission characteristics will affect the cure speed.

Application and Curing of Type SK-9: Squeeze a few drops of Type SK-9 from the convenient dispenser bottle onto the concave surface, and place the convex surface there on. Press down firmly and gently until LENS BOND completely wets the matching surfaces. Then, with a slow rotary motion and light pressure, force air bubbles from between the lenses. Excess cement can be removed with a cloth slightly moistened with alcohol or acetone. (Excess solvent will remove cement from between the cemented components.) After pre-curing with an ultraviolet light, holding devices may be removed and the components carefully cleaned. Before environmental testing, however, the lenses must be fully cured.

Full-cure time is in addition to the pre-cure time. If there is any doubt about curing being achieved, allow components to cure for a longer period of time. The cement will not overcure.

Safety: Although Lens Bond Type SK-9 is quite safe to use, some persons may be sensitive to the chemicals comprising the formulation. For them, the use of finger cots or gloves is recommended. Adequate ventilation should be provided.

Notes: If the elements will undergo hostile environmental tests, allow 48-72 hours between full-cure and testing.

Specifications

Viscosity..........................80 cps. to 100 cps.
                                   Also available in 40 cps. and 60 cps. 
Refractive Index (full-cured)......1.49 
Refractive Index (uncured).........1.47 
Operational Temperature Range......-50캜 to 100캜 
Youngs Modulus.....................4 x 105psi 
Water Absorption...................0.8% (after 7 days at 22캜) 
Tensile Shear......................4000-4500 psi 
Shrinkage on Cure..................<.25% 
pH.................................<3.8 
Specific Gravity...................1.08 
Elongation.........................4.7% to 5.1% 
Shore D. Hardness..................90 
Coefficient of Thermal Expansion...7x10-5/캜/0캜 to 50캜 
Surface Tension....................35-37 dynes/cm 
Glass Transition (Tg)..............99캜 to 101캜 
Shipping and Storage...............Type SK-9 needs no special handling 
                                   or storage. It should, however, be 
                                   kept away from intense light and 
                                   elevated temperatures. 
Shelf Life.........................12 months from date of manufacture 
                                   at room temperature. 
Size...............................30gms(1oz); 500gms(16 oz)

Suggested Applications

Bonding of plastics to plastics, plastics to glass, plastics to metal, and substrates with low UV transmittances (40%-60%), and where a thinner bond layer is desired.