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Polyurethane systems for lenses

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The use of general polymers in cast production lens, manufacturers improve the possibilities to performer lenses without glass.

Most important polymers are:

  1. Polycarbonate (PC)

  2. Copolymers cycloolefines (COC)

  3. Acrylic Resins (PMMA)

  4. Polyurethanes

The old types materials in the optical area, are the first 3 (PC,COC, PMMA), while PUR is a new introduction polymer.

Japanese and States are from Companies specialized in Polyurethane systems for lens and their relative patented products: Mitsui, Ashai, Simula and PPG are these Companies.Patented Products from USA compared Japanese Mitsui and Ashai products, showed the use of aromatic amine in the first one and aromatic amine with polyether sulphured in the second.

Resal Company has developed the advanced technology without the use of aromatic amine and polythyols.

Characteristics of the polyurethane system by Resal

From many years Resal produce a special polyurethane systems for various applications. The great properties of the polyurethane make a suitable material for medical, spatial, adhesive etc. applications.The use in optical field is not old and is a military shunt. The Resal’PUR is a system with a big difference from japaneese and USA patents. Some  societies have a PUR system isocyanate prepolymer  and aromatic amine based.

The greater differencies in the systems are :

Other companies

RESAL

Polvol

Aromatic amine

Polyether

Polvol toxicity

Yes

No

Prepolymer typt

Alifatic

Alifatic

PUR type

Urea

polyurethane

Polvol / Isoc. Ratio

1:9

1:1,70

Supply type

Only prepolymer

Prepolymer + polvol

liquid components

Yes

Yes

PUR  HDT

Yes

Yes

Links formation

Fast

Fast - Medium

From the above table it is possibile to see that Resal systems is the best for handling and not toxique.

The Resal PUR system not meet the present patents of other competitors because start from different raw materials.