Perfluoroalkylether macromer having two polymerizable groups

Details Perfluoroalkylether macromer having two polymerizable groups Perfluoroalkylether macromer having two polymerizable groups

1998-01-26

1999-10-05

Lipman, Bernard

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Polymers from only ethylenic monomers or processes of...

526245, 526246, C08F 1624

Patent

active

059626119

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to macromers, polymers and polymeric materials particularly suited for use in contact lenses.
In order to properly function as a contact lens a material must have a variety of properties including biological and chemical inertness, mechanical stability, optical transparency, oxygen permeability, and tear wettability. It is particularly advantageous for a contact lens to be able to transmit oxygen to the cornea and to be soft and comfortable to permit wear for extended periods.
Contact lenses can be classified into hard and rigid contact lenses, such as those manufactured from poly(methyl methacrylate), and soft flexible contact lenses such as those manufactured from poly(2-hydroxyethyl methacrylate). Both of these basic types of contact lenses suffer from various limitations. Hard and rigid contact lenses are uncomfortable to wear and thus are not well-tolerated by some patients. Although poly(methyl methacrylate) hard lenses allow the transmission of virtually no oxygen through the lens to support the cornea, there are some classes of rigid lenses that do allow good oxygen passage (for example, silicon-based materials). Notwithstanding this, they suffer from the aforesaid limitation of poor comfort due to their lack of softness. For optimum comfort and handling the modulus of elasticity of the lens material would be from 0.5 to 5.0 MPa, preferably from 1.0 to 2.5 MPa.
Conventional soft contact lenses suffer from the disadvantage that there is insufficient oxygen transmissibility through the lens to support normal corneal physiology. Accordingly, they cannot be worn for extended periods. Clinical symptoms of this lens-induced hypoxia include limbal redness and corneal swelling. Ocular infection may result from extended hypoxia induced by contact lens wear. A minimum oxygen transmissibility would be above 50 Barrer, preferably above 87 Barrer for continuous wear.
There is a long felt need for contact lens materials that combine the comfort of a soft contact lens with an oxygen transmissibility sufficient to maintain normal corneal physiology. In one aspect the present invention provides materials which address this need.
Contact lenses should be comfortable and suitable for use over extended periods. In order to achieve comfort over extended periods a lens must have a low modulus of elasticity (that is, be soft). In addition, it is desirable that it be resistant to fouling by proteins, lipids, mucoids and the like. However, contact lenses must also be of sufficient durability to allow for handling and normal use.
U.S. Pat. No. 4,818,801 describes perfluoropolyether polymers for use as contact lenses. While some lenses manufactured from the perfluoropolyether polymers described in U.S. Pat. No. 4,818,801 have excellent oxygen permeability such lenses remain too stiff, or of too high a modulus, to be useful as comfortable extended wear contact lenses.
There is required a polymer which possesses antifouling properties, oxygen permeability and a low modulus suitable for use in contact lenses and other applications. We have now found a macromonomer which is suitable for use in the manufacture of such polymers. Accordingly, in its main aspect, this invention provides a macromonomer of the formula I: formula II: CF.sub.2 CH.sub.2 O-- (II) distributed or distributed as blocks throughout the chain and wherein x and y may be the same or different such that the molecular weight of the PFPE is in the range of from 242 to 4,000;
Preferably n is in the range of from 2 to 5, more preferably in the range of from 2 to 4. We have found that the modulus of elasticity in polymers formed from these macromonomers can be controlled by variation of n. In general, increasing n results in polymers with decreased stiffness.
Q is a polymerizable group which preferably comprises an ethylenically unsaturated moiety which can enter into a polymerization reaction. Preferably Q is a group of the formula A --CONH--, --NHCONH--, --COO--, --OCO--, --NHCOO-- or --OCONH--; atoms; --OCONH--.
A free-radical-polymeriz

REFERENCES:
patent: 4929692 (1990-05-01), Goldenberg
patent: 4933408 (1990-06-01), Goldenberg
patent: 5185421 (1993-02-01), Cohen et al.
patent: 5247035 (1993-09-01), Besecke et al.

Affiliated with

Also associated with

Rating

Perfluoroalkylether macromer having two polymerizable groups does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Perfluoroalkylether macromer having two polymerizable groups, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Perfluoroalkylether macromer having two polymerizable groups will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1172783