Differences of MR-6 through MR-10 Materials for dummies like me...

[Uncle Fester]

Can someone help (re)enlighten me on the difference of the various MR (what's that?) materials. I've tried searching but my admittedly limited computer skills have failed to produce a concise explanation.

The opticampus calculator lists 5 as follows:

1.6 Finalite MR-6
1.6 MR-6
1.6 MR-8
1.67 MR-7
1.67 MR-10

Also what is 1.7 EYRY

Any help is appreciated.

[Fezz]

MR = Mitsui Resin (Misui Chemical Company)

[optigrrl]

A monomer composition which provides a plastic optical material having high refractive index and Abbe number, a low specific gravity and excellent physical properties, such as dyeing properties, heat resistance, impact resistance and the like. The composition comprises a di(meth)acrylate compound, divinylbenzene and/or divinylbiphenyl, a crosslinking-type isocyanate compound, a polythiol compound having two or more thiol groups, and a thiourethane bonding accelerating compound. The plastic optical material obtained by the reaction of the above composition with a radical polymerization initiator is used as a material for a lens. -as found doing a google search...

Originally Posted by Pete Hanlin
MR-6, as you indicate, is a 1.60 material...
MR-7 is a 1.66 (1.67, depending upon the measurement standard being used)...
MR-8 is an improved 1.60...
MR-10 is a 1.67 high index...

As far as I know (and I can check), Essilor uses the MR-7 monomer. Most of the material technology in this index comes from our partnership with Nikon. I believe the important things to keep in mind are as follows:
1.) most high-index materials have similar properties
2.) likewise, most make very good candidates for drill mount applications
3.) the coating(s) will greatly affect the durability (both scratch and resistance to breakage) of a high index lens

The Seiko monomer is a nice product- as are the high index monomers of each major manufacturer producing high index lenses today (each of which is slightly tweaked but ultimately derived from pretty much the same sources). Perhaps lenses could be labeled with "MR-6,7,8,10, etc.," but the differences in material performance will be far outweighed by the differences in lens design performance, so one's decision will still come down to what PAL or Aspheric SV lens design is preferred by the dispensing Optician/Optometrist/Ophthalmologist.

That's all I could find on the subject, I hope it helps!

The 1.7 EYRY is Hoya's ultra-high index lens material (has a better abbe value than 1.67) that is available on Hoya lens designs.

[mullo]

EYRY is a Hoya brand name for their 1.7 index lens. They also have Eyas 1.6 and Eynoa 1.67. If I remember correcty they mean eagle/falcon related or something to that effect?

Can someone help (re)enlighten me on the difference of the various MR (what's that?) materials. I've tried searching but my admittedly limited computer skills have failed to produce a concise explanation.

The opticampus calculator lists 5 as follows:

1.6 Finalite MR-6
1.6 MR-6
1.6 MR-8
1.67 MR-7
1.67 MR-10

Also what is 1.7 EYRY

Any help is appreciated.

[Uncle Fester]

Thanks Fezz
Thanks Opigrrl-Forgot to add a comment for the grennie I gave you!:)

[Darryl Meister]

I have a list of the most common Mitsui lens materials and their typical optical properties available at Material Reference Chart.

As noted, the MR (Mitsui Resin) lens materials all polythiol-urethanes from Mitsui Chemicals. In short, MR-8 represents a newer version of the once popular MR-6 1.60 high-index material with a higher Abbe value and slightly lower density. MR-10 represents a newer version of the MR-7 1.67 high-index material with slightly greater tensile strength and heat resistance, although impact resistance and tintability are slightly poorer. MR-174 is a relatively new 1.74 high-index material.

[braheem24]

Which are ok for drill?

Specifically is 1.6 MR-8 ok for drilling?

[Darryl Meister]

MR-6, 7, 8, and 10 should all work well in drill mounts.

[scriptfiller]

braheem24,

I've switched to 1.60 on all my premium drill mounts. I have become irritated when poly comes back with the good ole "star" cracks. To my knowledge, I have never had any MR series lense come back for "star" cracks.

[MarcE]

MR-6, 7, 8, and 10 should all work well in drill mounts.

I don't know the exact formulation, but the pre 2006 version of 1.60 that Essilor and Shamir used were not suitable for drills in my opinion. THey were too brittle. However they switched formulations and the newer versions are good.

Someone will chime in if I am confused. I hope.

[Darryl Meister]

I don't know the exact formulation, but the pre 2006 version of 1.60 that Essilor and Shamir used were not suitable for drills in my opinion. THey were too brittle. However they switched formulations and the newer versions are good.

I don't recall for certain what monomer they were using, but the MR resins are all very similar in terms of tensile strength, ranging from roughly 100 to 110 megapascals.

Of course, the tensile strength of the final lens is based upon several factors, including the specific additives used by the manufacturer, the thickness of the lens, the application of any brittle coatings, etcetera.

[sandeepgoodbole]

Any other companies providing Polymer Lenses other than Mitsui ?

[chip anderson]

All lenses except glass and CR-39 (which is a resin) are polymer lenses. CR-39 may be too, I just don't know enough chemistry to be sure.
All or almost all plastics are polymers.


Chip

[WFruit]

I am dredging up this two year old thread with a simple question: What happened to MR-9?

Also, most 1.74's are MR-174, but Seiko's is a HR-74....Anyone know what the HR stands for?

[Darryl Meister]

I am dredging up this two year old thread with a simple question: What happened to MR-9?

They probably use it for skateboard wheels or something. ;)

Also, most 1.74's are MR-174, but Seiko's is a HR-74....Anyone know what the HR stands for?

I believe that SEIKO uses Mtisui's MR-174 resin. SEIKO's "HR" designation stands for "heat resistant."

Best regards,
Darryl