Medical device using sulfonated neutralized polymers with reduced adhesion of biological fluids

1. An article comprising a thermoplastic neutralized sulfonated polycarbonate,

wherein an interior surface of the article is functionalized with a sulfonate salt group containing a cation selected from the group consisting of sodium, potassium, magnesium, calcium, and mixtures thereof, the sulfonate salt functionalized surface having at least 50% less adhesion of a biological fluid having a molecular weight of from 5,000 to 400,000 Daltons and selected from the group consisting of insulin, human growth hormone, human serum albumin, fibrinogen and mixtures thereof, than a surface that is not functionalized with a sulfonate salt group;

wherein an exterior surface of the article is coated with a clear scratch-resistant coating; and

wherein the interior surface is not clear coated; and

wherein the article is a medical article selected from the group consisting of a blood bowl, syringe, dialysis unit, pump, or tube.

2. The article of claim 1 , wherein the sulfonate salt group is an aryl sulfonic acid salt.

3. The article of claim 1 , wherein the polycarbonate has a light transmittance of 70% or greater at a thickness of 3.2 mm, when measured according to ASTM D1003.

4. The article of claim 1 , wherein the sulfonate salt functionalized surface is sulfonated to a depth of 50 microns or less.

5. The article of claim 1 , wherein the sulfonate salt functionalized surface has a water contact angle of 25 degrees or less.

6. The article of claim 1 , wherein the article is neutralized to a pH of from about 6 to about 8.

7. The article of claim 1 , wherein the article is formed by:

molding the article from a polycarbonate to form a polymeric article;

contacting the polymeric article with sulfur trioxide to sulfonate a surface of the article; and

neutralizing the sulfonated surface with a liquid carboxylate salt solution to form the article having a sulfonate salt functionalized surface.

8. The article of claim 1 , wherein the surface of the article is functionalized by a process comprising:

providing the article having a non-functionalized surface;

contacting the surface of the article with sulfur trioxide to form sulfonic acid groups on the surface of the article; and

neutralizing the sulfonic acid groups with an aqueous carboxylate salt solution to form the article having a surface functionalized with a sulfonate salt group, wherein the aqueous solution contains from 10% to 50% by weight of the carboxylate salt.

9. The article of claim 8 , wherein the carboxylate salt has a solubility at 23° C. of at least 25 grams of salt per 100 ml water, wherein the carboxylate salt has from one to six carbon atoms and contains a cation selected from the group consisting of sodium, potassium, magnesium, calcium, and mixtures thereof.

10. The article of claim 1 , wherein the surface of the article is functionalized by a process comprising:

providing the article having a non-functionalized surface;

drying the article to less than 200 ppm water;

contacting the non-functionalized surface of the article with gaseous sulfur trioxide to form sulfonic acid groups on the surface of the article; and

neutralizing the sulfonic acid groups with an aqueous carboxylate salt solution to form the article having a surface functionalized with sulfonate salt groups, wherein the aqueous solution is from 10 to 50% by weight of the carboxylate salt and wherein the carboxylate salt has from one to eight carbon atoms.

11. The article of claim 1 , wherein the polycarbonate has a yellowness index of 10 or less, when measured according to ASTM D6290 at a thickness of 3.2 mm.

12. The article of claim 1 , wherein the polycarbonate has an impact strength of 5 ft-lbs/inch or greater, when measured according to ASTM D256 at a thickness of 3.2 mm.

13. The article of claim 1 , wherein the polycarbonate has a haze level of 15% or less at a thickness of 3.2 mm, when measured according to ASTM D1003.