Reactive polymers

#The present invention relates to novel highly reactive polymer derivatives, articles such as biomedical articles, especially contact lenses, which are at least partly coated with said polymer derivatives and a process for coating inorganic or organic substrates using the novel polymer derivatives.

#A variety of different types of processes for preparing polymeric coatings on a substrate have been disclosed in the prior art. For example, U.S. Pat. No. 5,527,925 describes functionalized photoinitiators and also organic substrates such as contact lenses containing said photoinitiators covalently bound to their surface. In one embodiment of said disclosure, the so modified surface of the contact lens is further coated with a photopolymerizable ethylenically unsaturated monomer which is then polymerized by irradiation thus forming a novel substrate surface. With this method, however, it is not always possible to obtain the desired coating characteristics, for example wettability characteristics which are necessary for the surface of biomedical devices including contact lenses. Most important, the known surface modification process is applicable only to articles having a functionalized surface, that is to say, the surface of the article either inherently contains functional groups or the functional groups have to be introduced previously by a plasma treatment or the like. However, it would be highly desirable to initiate the covalent binding of a hydrophilic layer on an “inert” surface and thereby avoiding a previous plasma treatment or the like.

#Surprisingly, now there have been found novel reactive polymer derivatives which are able to react with the surface of articles that is devoid of functional groups. By means of said novel polymers it is possible to obtain articles, particularly biomedical devices such as, for example contact lenses, with an improved wettability, water-retention ability and biocompatibility.

#(Synthesis of a Diazirine NHS Ester)

#7.06 g (36.81 mmol) N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide hydrochloride are given into a 500 mL round bottom flask filled with 200 mL water at pH 12. After 15 minutes stirring at room temperature 50 mL dichlormethane are added. The extraction is repeated three times with 50 mL dichlormethane. The organic phases are combined, dried over MgSO4, filtered and dried at high vacuum. The free base is given into a 250 mL round bottom flask and dissolved in 150 mL acetonitrile (28.4 ppm water). 17.19 g (—12 mmol Cl) Merrifield polymer is added. The suspension is heated to 100° C. under reflux for 16 hours. After cooling to room temperature the activated Merrifield polymer is washed 3 times with 50 mL acetonitrile, 2 times with 50 mL diethylether and dried at high vacuum. 300 mg (1.30 mmol) 4-(1-azi-2,2,2-trifluoroethyl)benzoic acid, 135 mg (1.17 mmol) N-hydroxysuccinimide, 6.3 g activated Merrifield polymer and 45 mL chloroform are given into a 100 mL brown round bottom flask and shaked at room temperature. DC control indicates complete conversion after 30 minutes. The mixture is filtered and washed with chloroform. The filtrate is dried at high vacuum. Complete reaction is determined by 1H-NMR spectroscopy.

#(Synthesis of a Monofunctional DMA Telomer)