TYPE M-62

Because of its 1 hour oven cure at 70°C, Type M-62 is used by companies cementing large quantities of optical elements, and with its 4 hour room temperature pre-cure, the use of Type M-62 permits the technician to mix a quantity of cement and bond many elements before the cement starts to gel. This cement is qualified to meet MIL-A-3920.


 

12100
Lens Bond Type M-62
bottle w/catalyst
4oz
 

13000 
Additional Catalyst
  3cc
 
13003
Thinner (Monomeric styrene)
4oz
 
13004
Plasticizer Modifications
.5-5%
 
13008-A
*Refractive Index Adjuster
  5gr
 

Approximate Curing Times

  Room Temperature
22°(72°F)
Oven Temperature
70°(160°F)

Catalyst Ratio

Pre-Cure Full-Cure Pre-Cure Full-Cure
2:100 4 hours 4 days 20 minutes 1 hours
3:100 3 hours 3 days 15 minutes 45 minutes
5:100 2 hours 2 days 10 minutes 30 minutes
NOTE: Sufficient catalyst is supplied with each bottle of cement. The catalyst ratio shown at the top is recommended as standard. Changes in the ratio shown will alter the curing times shown, i.e., cure rate can be accelerated slightly by increasing the catalyst.

Instructions For Use

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

2. Preparation of Cement: Prepare Type M-62 by the addition of catalyst to cement in a clear glass container. Thorough mixing is important. While stirring, hold container up to the light and observe the Schlieren Effect. When the Schlieren Effect disappears, continue mixing for at least 30 seconds. The entrapped air in the cement will surface if the mixture rests at room temperature for a short time, or is briefly subjected to a vacuum of 625mm Hg. (25" Hg.) The catalyst bottles have a specially designed controlled-drop tip, pre-calibrated at our laboratory to an accuracy of ± 1%. To use, squeeze the inverted bottle, allowing one drop to fall at a time. For 2:100 mixture, use 2 drops per 3ml. of cement. For 5:100 mixture, use 5 drops per 3ml of cement. (or 8 to 5ml or 40 to 25ml).

N.B. The catalyst bottle supplied with Type M-62 Cement contains more than sufficient catalyst for a 3:100 catalyst:cement ratio.

Safety: Although LENS BOND 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.

3. Application and Curing of Type M-62: Place the prepared LENS BOND on the concave surface, and place the convex surface thereon. 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-cure, holding devices can 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 no reason to remove holding devices after pre-cure, components should be cured for the total time (pre-cure plus full-cure). If there is any doubt about cure being achieved, allow components to cure for a longer period of time. The Cement will not overcure. If cure is not achieved in a reasonable amount of time, the catalyst ratio, mixing procedure, and temperature should be checked.

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

Specifications

Viscosity........................275 cps. to 320 cps. 
Refractive Index (full-cured)....1.55 at 25°C 
Refractive Index (uncured).......1.53 
Operational Temperature Range....-54°(-65°F) to 100°C(212°F) 
Youngs Modulus...................6.2 x 105lbs/in2 
Shear Strength...................5200 lbs/in2 
Impact...........................(.3 to .4)ft lb/in 
Specific Heat....................(.2 to .4) Cal/gm 
Dielectric Constant..............3 at 106 cps 
Loss Factor at 106 cps...........(.05) 
Water Absorption.................0.3% (24 hours. 25°C on bulk material) 
Dispersion Formula...............n=1.5754-(0.04742)-[0.0070/(2-0.028)]+
[
0.0011/(2-0.028)2] Shrinkage on Cure................Approximately 4% pH...............................3.2 Specific Gravity.................1.22 Shore D. Hardness................Approximately 90 Surface Tension..................44 Dynes/cm. Linear Coefficient of Expansion..Approximately 6.3x10-5/°@ between 27°C-100°C 5.58x10-5/°@ between 100°C-200°C Thermal Conductivity.............500x10-6 cal(sec)(sq.cm)(°C)(cm) Flash Point (uncured)............50°C Glass Transition (Tg)............>90°C Outgassing TML...................2.5% Outgassing CVCM..................0.1% Shipping and Storage.............Type M-62 needs no special handling or storage. It should, however, be kept away from intense light and elevated temperatures. Shelf Life.......................18 months from date of manufacture Size.............................114 gm(4oz)
*The reference index may be increased to 1.59-1.61 with the use of our Cat# 13008,
 - Refractive Index Adjuster
For technical data on adhesion properties, solvent and thermal resistance as well as 
transmission studies, please go to our technical data section on this site.