MXPA96002198A - Lubricating coatings containing polymers with vinyl and carboxyl acid residues - Google Patents

Abstract

Lubricating coatings comprising a binder polymer having a vinyl residue and a carboxylic acid residue and a hydrophilic polymer are disclosed. The coatings can be applied to a variety of substrates such as, for example, probes, extenders, expansion balloons, guide wires, endotracheal tubes, instruments, grafts and other biomedical devices and can provide exceptional lubricity and abrasion resistance. They are released lubricosos either in one or two steps of coating

Description

"LUBRICATED COATINGS CONTAINING POLYMERS WITH VINYL RESIDUES AND CARBOXYLIC ACID" FIELD OF THE INVENTION This invention relates to lubricious coatings for substrates, such as, for example, biomedical devices. More specifically, the present invention relates to lubricious coatings containing a hydrophilic polymer that is lubricious in an aqueous environment and a binder polymer for adhering the hydrophilic polymer to the substrate.

BACKGROUND OF THE INVENTION A variety of lubricious coatings have been proposed for use in biomedical devices, such as, for example, probes, guide wires, endotracheal tubes and grafts. Common materials used in the art to provide lubricious coatings for biomedical devices include, for example, oil, silicone and polymeric materials, such as poly-N-vinyl pyrrolidone, hydrophilic polyurethanes, Teflon, polyethylene oxide and polyacrylic acid. Among the most common materials used to provide coatings lubri- cated are the hydrophilic polymers that are covalently bonded to the substrate with a binder polymer having reactive functional groups, eg, isocyanate, aldehyde and epoxy groups. Although the use of these binder polymers having reactive functional groups is effective in providing lubricious coatings having a high degree of abrasion resistance, these binder polymers are often highly reactive, toxic and typically require special handling techniques in order to avoid potential health, safety and environmental problems. Accordingly, new, improved lubricious coatings using binder polymers are desired, which are less toxic than those which contain highly reactive functional groups, such as isocyanates, but which nevertheless can provide a high degree of lubricity and abrasion resistance.

SUMMARY OF THE INVENTION In accordance with the present invention, improved lubricious coatings are provided for use in biomedical devices, such as, for example, probes, guide wires, endotracheal tubes, balloons and grafts. The coatings have a hydrophilic polymer that is considerably more lubricious when wetted with an aqueous liquid than when it is dry, and a binder polymer that is capable of being bound to the surface of the biomedical device and the hydrophilic polymer. Suitable binder polymers for use in accordance with the present invention are copolymers comprising a vinyl residue, preferably vinyl chloride or vinyl acetate, and a carboxylic acid residue. By means of the present invention, it is now possible to provide lubricious coatings for substrates that can provide exceptional lubricity and abrasion resistance without the need to use highly reactive, toxic chemicals to covalently bind the hydrophilic polymer to the surface of the substrate.

DETAILED DESCRIPTION OF THE INVENTION The binder polymers suitable for use in accordance with the present invention are copolymers, ie, polymers produced from two or more monomers, comprising at least one vinyl residue and at least one carboxylic acid residue. He Vinyl residue and the carboxylic acid residue may be present in the same monomer or in different monomers. The vinyl residue can be derived from any monomer having a vinyl group, such as, for example, commonly found in compounds such as vinyl chloride, vinyl acetate and the like. Preferably, the vinyl residue has the formula (CH2 = CH-). Typically, the monomers containing the vinyl residue comprise from about 2 to 20 carbon atoms per molecule, more often from about 2 to 8 carbon atoms per molecule. These vinyl monomers may contain one or more v.gr., 2 or 3 vinyl groups per molecule. Preferably, the vinyl monomer is insoluble in water. Without wishing to be bound by any specific theory, it is believed that polymer residues derived from water-insoluble vinyl monomers can provide improved adhesion of the binder polymers to substrates as compared to water-soluble vinyl monomers. As used herein, the term "water soluble" means that at least 10 weight percent ("weight percent") of the monomer solution is soluble in water. Examples of vinyl monomers that may be suitable for use in accordance with this invention include, without limitation vinyl halides e.g., vinyl chloride, vinyl fluoride, vinyl bromide, vinyl trichloride; vinyl ethers e.g. vinylethyl ether, vinylbutyl ether, vinyl ethylhexyl ether, vinyl esters e.g. vinyl acetates, vinyl butarate, vinyl stearate, vinyl propyanate, vinyl ethylhexanoate; vinylmethyl ketone, vinyl acetylene, butadiene, vinyl alcohol (produced in situ through the hydrolysis of vinyl acetate residues in the polymer) and vinylidene compounds. Vinyl halides, including vinyl chloride, vinyl fluoride and vinyl bromide are the preferred vinyl monomers to be used in accordance with the present invention. Vinyl chloride is an especially preferred monomer for use in accordance with the present invention. Vinyl ester monomers and in particular, vinyl acetate are also preferred for use in accordance with the present invention. Especially preferred are combinations of vinyl halides and vinyl esters, e.g., vinyl chloride and vinyl acetate. The total concentration of the vinyl monomers in the binder polymer is typically from about 10 percent to 99.9 mole percent, preferably from about 50 percent to 99.5 mole percent, and, most preferably, about 70 percent. percent to 99 mole percent. The selection of the specific vinyl monomers and their proportions in the binder polymer should be selected in order to provide an improved bond to the surface of the substrate to be coated. For example, a vinyl monomer that is identical or essentially similar or compatible with one or more of the monomeric periodic units present in the substrate is preferred to provide improved physical bonding between the polymeric binder and the substrate. More than one vinyl monomer can be used. Additional details related to the selection and amounts of the vinyl monomers are known to those skilled in the art. In addition, these vinyl monomers can be obtained commercially. The carboxylic acid residue can be derived from any organic acid containing a carboxyl group. Typically, the carboxylic acid contains from 1 to about 26, more typically from 1 to 8 carbon atoms per molecule. Preferred carboxylic acids include but are not limited to: acrylic, methacrylic, maleic, itaconic, fumaric and the like. Other carboxylic acids, such as, for example, the unsaturated fatty acids and the polymerizable aromatic and alicyclic carboxylic acids can also be used. In addition to the carboxylic acids mentioned above, the corresponding anhydrides, e.g., the maleic anhydride can also be used, as long as the anhydride is hydrolysed to its acid form in order to activate the binding of the hydrophilic polymer. Otherwise, lower abrasion resistance may result. Carboxylic acid groups may be present in their free or partially neutralized acid form as long as there is a sufficient amount of free acid to activate the binding between the hydrophilic polymer and the binder polymer. The total concentration of the carboxylic acid-containing monomer in the binder polymer typically ranges from about 0.1 percent to 20 mole percent, and preferably from about 0.5 percent to 5 mole percent. The amount of the carboxylic acid monomer should be selected so as to provide improved binding of the hydrophilic polymer to the binder polymer and the substrate. Additional details related to the selection and amounts of the carboxylic acid containing monomers are known to those skilled in the art. In addition, these carboxylic acid monomers can be obtained commercially.

In addition to the vinyl and carboxyl-containing monomers that are defined above, one or more other monomers may be used as additional monomers in the binder polymers of the present invention. These additional monomers may be introduced, for example, in order to provide desired physical, mechanical or chemical properties to the binder polymer eg, solubility, processability, melting temperature, vitreous state transition temperature, hardness, resistance to the tension and similar properties. Examples of these monomers include isoprene, hydroxyethyl acrylate, alpha-methyl styrene, propylene, ethyl acrylate, methyl methacrylate, sulfonated acrylates and the like. Preferably, the selection and amounts of monomers used to prepare the binder polymers of the present invention are effective to provide a binder polymer having the desired degree of adhesion and flexibility when applied to the substrate. Certain binding polymers may be more effective in certain substrates than in others. Additional details related to the selection and amounts of the monomers used to produce the binder polymers are known to those skilled in the art. It is also preferred that the binder polymers of the present invention have a molecular weight of from about 5,000 to 1,000,000, more preferably from about 20,000 to 500,000 and especially preferably from about 20,000 to 100,000 grams per gram-mol. As used herein, the term "molecular weight" means the number average molecular weight. Techniques for determining number average molecular weight are known to those skilled in the art. Typical copolymers suitable for use as binder polymers in accordance with the present invention include, but are not limited to, polymers of maleic acid-vinyl chloride, vinyl acetate, acrylic acid-vinyl chloride-vinyl acetate, acid maleic-vinyl chloride-vinyl acetate-vinyl alcohol, acrylic acid-styrene-vinyl acetate, maleic acid-vinyl ether, and acrylic acid-styrene-butadiene. These polymers can be polymerized in a random block or grafted polymer form. Additional details related to the preparation of these copolymers are known to those skilled in the art. In addition, many of the copolymers described above can be obtained commercially from a variety of backgrounds.

The hydrophilic polymers suitable for use in accordance with the present invention are any of the water-soluble or water-swellable polymers that are considerably more lubricious when wetted with an aqueous liquid than when they are dry. As used herein, the term "water-swellable" means an essentially hydrophilic polymer which, even when not soluble in water, absorbs sufficient water to make it lubricious in the hydrated state. In addition, the term "hydrophilic" as used herein means that water droplets do not easily form pearls on the surface of this hydrophilic material but instead water droplets tend to adopt a contact angle of less than 45 cm. ° and they are easily dispersed on its surface. Preferred hydrophilic polymers include, but are not limited to, those selected from the group consisting of polyvinyl compounds, polysaccharides, polyurethanes, polyacrylates, polyacrylamides, polyalkylene oxides and complex copolymers, mixtures and derivatives thereof. Poly-N-vinyl lactams are the preferred polyvinyl compounds for use in accordance with the present invention. The term "poly-N-vinyl lactam" as used herein means the homopolymers and copolymers of these N-vinyl lactams, such as N-vinyl pyrrolidone, N-vinyl butyrolactam, N-vinyl caprolactam and the like as well as the foregoing which are prepared with small amounts, for example, up to about 20 percent by weight of a monomer or a mixture of other copolymerizable vinyl monomers with the N-vinyl lactams. Of the poly-N-vinyl lactams, poly-N-vinyl pyrrolidone homopolymers are preferred. A variety of poly-N-vinyl pyrrolidones are commercially available and of these a poly-N-vinyl pyrrolidone having a K value of at least about 30 is especially preferred. The K value is a mediated molecular weight, the details of which are known to those skilled in the art. Other preferred hydrophilic polymers for use in accordance with the present invention include but are not limited to those selected from the group consisting of copolymers of N-vinyl pyrrolidone-hydroxyethyl acrylate, carboxymethyl cellulose, hydroxyethyl cellulose, polyacrylamide, polyhydroxyethyl acrylate, hydroxyethyl cellulose cationically modified, polyacrylic acid, polyethylene oxide and complexes, mixtures and derivatives of the mimes. Especially preferred are poly-N-vinyl pyrrolidone, polyethylene oxide and cellulosic materials, such as, for example, carboxymethylcellulose and cationically modified cellulose. Suitable hydrophilic polymers for use in accordance with the present invention can be nonionic, cationic, anionic or amphoteric. Typically, the molecular weight of the hydrophilic polymers is from about 100,000 to 10,000,000 grams per gram-mol, preferably from about 200,000 to 5,000,000 grams per gram-mol and more preferably from about 300,000 to 2,000,000 grams per gram-mol. . Additional details related to the preparation and selection of the hydrophilic polymers suitable for use in accordance with the present invention are already known to those skilled in the art. These hydrophilic polymers can be obtained commercially in an easy manner from a variety of sources, such as for example Union Carbide Corporation of Danbury, Ct. It is preferred as in accordance with the present invention that the hydrophilic polymer be bound to the binder polymer by hydrogen bonding or ionic bonding. Although it is not necessary to practice this invention, there may be some degree of covalent bond between the binder polymer and the hydrophilic polymer. However, preferably there is a considerable absence, that is, less than about 5 percent more preferably less than about 1 percent covalent bonds between the binder polymer and the hydrophilic polymer based on the total number of binding sites between the binder polymer and the hydrophilic polymer. It is also preferred that there be a substantial absence, ie, less than about 5 percent more preferred, less than about 1 percent highly reactive functional residues that are selected from the group consisting of isocyanate, aldehyde and epoxy residues in the polymer binder. In addition to the binder polymers and the hydrophilic polymers, the lubricious coatings of the present invention may comprise one or more additives normally used in coating formulations, such as, for example, surfactants, preservatives, viscosity modifiers, pigments, colorants. and other additives known to those skilled in the art. In addition, other functional additives which are ionically bound to the hydrophilic polymer can also be used. These additives include ingredients, such as for example, therapeutic agents, antithrombogenic agents, agents antimicrobials and antibiotic agents. When ionic additives are used in the coating, e.g., heparin which is anionic, it is preferred to use a cationic hydrophilic polymer eg, a cationically modified hydroxyethylcellulose. Similarly, when an additive is cationic, it is preferred to use an anionic hydrophilic polymer eg, a polyacryl acrylamide polymer. When an antimicrobial agent, such as 2, 4, 4'-trichloro-2'-chloroxydiphenyl ether is used as an additive, either an ionic or a nonionic hydrophilic polymer can be employed. The combination of an additive and a hydrophilic polymer can be varied as necessary to provide the desired performance. The substrates to which the lubricious coatings of the present invention can be applied are not limited. Substances that are usable for substrates include but are not limited to various organic polymeric compounds, such as, for example, polyamides, polyesters, e.g., polyethylene terephthalate and polystyrene terephthalate, polyvinyl chloride, polyvinylidene chlorurue, polystyrene , polyacrylic esters, poly ethyl methacrylate and other polymetracrylic esters, polyacrylonitrile, polyethylene, polypropylene, polyurethane, polyvinyl acetate, resins silicone, polycarbonate, polysulfone, polybutadiene and styrene polymers, polyisoprene, nylon, polyethylene, polypropylene, polybutylene, halogenated polyolefins, various latexes, various copolymers, various derivatives and mixtures thereof and various inorganic and metallic substances, such as for example , glass, ceramic, stainless steel and superelastic metal or configuration memory alloys, such as, for example, a Ni-Ti alloy. Typical substrates to which the lubricious coatings of the present invention can be applied include but are not limited to probes, balloon probes, guidewires, endotracheal tubes, grafts and other biomedical devices, such as, for example, the outer surface of a endoscope The lubricious coatings of the present invention can be applied by either a two-step coating process or a one-step coating process. In a two step coating process, the portion of the substrate to be coated is first coated with the binder polymer and subsequently coated with the hydrophilic polymer. In a one-step coating process, the binder polymer and the hydrophilic polymer are applied to the substrate in a single step. It can be used in accordance with the present invention, any of the liquid coating processes conventional These processes include, for example, dip coating, spray coating, knife coating and roller coating. Dip coating is a preferred coating method in accordance with the present invention. In the coating processes of the present invention, the binder polymers and the hydrophilic polymers can be supplied from liquids contained either in a solution, a dispersion or an emulsion of the polymers. In one-step coating methods, the binder polymers and the hydrophilic polymers are contained in the same liquid medium. In two-step methods, the binding polymers and the hydrophilic polymers are contained in separate liquid media. Additional coating steps may be employed to introduce the different polymers or additives. The liquid media used to supply the binder polymers and the hydrophilic polymers can be organic, aqueous or an organic-aqueous mixture. The liquid medium used to supply the agglutinating polymer can be selected so as to have some solvency for the substrate, that is, when the substrate is polymeric. This can improve the adhesion between the binder polymer and the substrate and aid the film formation of the coating material. The Preferred liquid media for supplying the binder polymers and the hydrophilic polymers include but are not limited to esters, v, g, ethyl acetate, isopropyl acetate; alcohols, e.g., isopropyl alcohol, ethanol, butanol; ketones, e.g., acetone, methylethyl ketone, diacetone alcohol, methyl isobutyl ketone; amides, such as dimethylformamide; toluene; glycol ethers, such as butyl glycol ether; fluorinated solvents, such as dichloroethane, water and mixtures thereof. Preferably the liquid media is selected so that the binder polymers and the hydrophilic polymers uniformly moisten the surface of the substrate to be coated. Preferably, the concentration of the binder polymer and the hydrophilic polymers in the liquid media are sufficient to provide the desired amounts of the respective polymers in the lubricous coatings. Typically, the concentration of the binder polymers in the liquid medium will vary from about 0.05 percent to 10 percent by weight and, preferably, from about 0.2 percent to 2 percent by weight, based on the total weight of the liquid medium. Typically, the concentration of the hydrophilic polymers will vary from about 0.1 percent to 20 percent by weight and preferably from 0.05 percent to 5 percent by weight, - lí based on the total weight of the liquid medium. Additional details related to the selection of liquid media for supplying the binder polymers and the hydrophilic polymers of the present invention are known to those skilled in the art. The coating processes of the present invention are preferably carried out in a liquid phase at atmospheric pressure and at a temperature of approximately 20 ° to 90 ° C. The residence times for contacting the surface of the substrate to be coated with the liquid media containing the binder polymer or the hydrophilic polymer or both vary from about 1 second to 30 minutes, preferably from about 10 seconds to 10 minutes. Generally, it is desirable to dry the coatings after application of the coating at a temperature of about 30 ° to 150 °, preferably in a forced air oven. Microwave ovens and infrared heaters can also be used if desired. Typical drying times vary from about 1 minute to 24 hours and preferably range from about 10 minutes to 5 hours. When a two-step coating process is employed, it is preferred to dry the binder polymer before application of the hydrophilic polymer.

The lubricious coatings resulting from the coating processes of the present invention typically have a thickness of about 0.05 micron to 10 microns and preferably about 0.1 micron to about 5 microns. When the two-step coating process is employed, the resulting coating preferably comprises an inner layer that is rich, that is, greater than 50 percent in the binder polymer that contacts the surface of the substrate, and a layer external that is rich, that is, greater than 50 percent in the hydrophilic polymer that comes in contact with the inner layer. The outer layer that is rich in the hydrophilic polymer has an outer surface that becomes lubricious when exposed to an aqueous liquid. When the one-step coating process is employed, the resulting coating comprises a single layer which is preferably an essentially homogeneous mixture of the binder polymer and the hydrophilic polymer. However, since the binder polymer will often have higher affinity for the substrate than the hydrophilic polymer, it is believed that there may be a higher concentration of the binder polymer near the surface of the substrate.

The following examples are presented for illustrative purposes and are not intended to limit the scope of the claims that will be given below.

EXAMPLES The following tests were used to carry out the examples. Contact Angle Testing: The contact angle of the distilled water in either a coated or uncoated substrate was measured using an NRL Contact Angle Goniometer Model A-100 (Rame'-hart, Inc., of Mountain Lakes, NJ ) at room temperature. The average value of three measurements was used. Friction Test Coefficient: A pair of probes were placed parallel to each other on a horizontal stainless steel platform at a separation distance of approximately 3.81 centimeters. The platform and probes were subsequently fully wetted with approximately 100 milliliters ("mi") of distilled water. An aluminum block shaped rectangular (5.08 centimeters X 5.08 centimeters X 7.62 centimeters) weighing 100 grams ("g") wrapped in a wet cellulose acetate membrane is placed on top of the probes at the end of the moving platform freely. Then, the platform rises gradually and steadily from the freely moving end until a tilt angle is reached < f where the block begins to slide on the surface of the wet probe. The coefficient of friction ("COF") is calculated as the tangent 0. Abrasion Test - The abrasion resistance of the wet coating is measured by abrading the wet probe through a silicone elastomer washer (the internal diameter of the the washer is made to be approximately 10 percent smaller than the outer diameter of the probe) during 100 abrasions, that is, careers. Each abrasion consists of a complete path back and forth of the probe through the washer. The COF of the probe subjected to abrasion is measured again and is known as the COF after abrasion. The following ingredients were used to carry out the examples. All the ingredients used in the examples can be obtained commercially from a variety of provenances.PVC - polyvinyl chloride. Endotracheal tubes of PVC - 32 French size. IPA - isopropyl alcohol.

Gantrez (R) AN119 - a copolymer of methylvinyl ether and maleic anhydride having a molecular weight of 20,000 grams per gram-mol, obtainable from ISP Technology, by Wayne, N.J. MEK - polyN-vinyl ethylethyl PVP-pyrrolidone ketone having a K value of K-90. CMC - carboxymethylcellulose having a molecular weight of about 250,000 grams per gram-mol which can be obtained as 99-7M8SXF from Aqualon Company, of Wilmington, FROM. DAA - diacetone alcohol. PVC drainage tubes - French size 20. Carboxylvinyl-I resin - a copolymer of vinyl chloride-vinyl acetate-maleic acid (weight percentage of 81-17-2) having a molecular weight of 15,000 grams per gram -mol. Carboxylvinyl chloride-II-resin - a vinyl chloride-vinyl acetate-maleic acid copolymer (weight percentage 83-16-1) having a molecular weight of 19,000 grams per gram-mol. Carboxylvinyl chloride-III resin - a copolymer containing vinyl chloride, vinyl acetate-hydroxyalkyl-carboxyl acrylate having a molecular weight of 26,000 grams per gram-mol which can be obtained as Vinyl of Water Carrier Bakelite Solution AW875 by Union Carbide Corporation, of Danbury, C. Tygon (R) pipe - internal diameter of 6.35 mm, external diameter of 9.53 mm. HEC1 Cationic - a quaternized hydroxyethyl cellulose having a molar weight and degree of substitution of 2.3 and 1. 85 respectively and a molecular weight of 750,000 grams per gram-mol. Cationic HEC2 - a quaternized hydroxyethyl cellulose having a molar weight and a degree of substitution of 2.3 and 1. 85 respectively and a molecular weight of 300,000 grams per gram-mol. PET - polyethylene terephthalate balloon probes. Polyethylene balloons - 2.5 cm expansion balloons. PET balls - expansion balloons of 6.5 centimeters.

Butyl glycol ether - ethylene glycol monobutyl ether.

In the Examples, two substrates were used for each test because the coefficient of the friction test requires two substrates to be carried out in parallel. One of the substrates was used for the contact angle test and an average of three readings is reported.

Example C-l A pair of PVC Tygon tubes were cleaned with thin paper containing IPA and air-dried for 10 minutes ("min."). The cleaned tubes were immersed in a 1 percent solution of Gantrez (R) AN119 in MEK for 10 seconds ("sec.") And were followed by drying in a forced air oven at 90 ° C for 30 minutes. The tubes were then immersed in a 2 percent by weight solution of PVP in a mixture of IPA / water (70/30 weight percent) for 1 minute and followed by drying in a forced air oven at 90 ° C. for 1 hour. The coated tube had a water contact angle of 16 °. The coated tube was initially luric but the lubricity was lost immediately during contact showing a lack of durability. This Example demonstrates that despite the presence of the vinyl residue, the lack of carboxylic acid residue in the binder polymer provided a coating with lower abrasion resistance.

Example 2 Example 1 was repeated with the exception that after the PVC Tygon tubes were coated with the first coating solution and dried at 90 ° C. for 30 minutes, they were soaked in distilled water overnight before the second coating was applied in order to activate the hydrolysis of the anhydride groups to the carboxylic acid groups. The coated tubes were initially lubricious and gradually lost their lubricity after 100 abrasions as evidenced by the following data: Sample Angle of Friction Coefficient Contact Before After abrasion abrasion 2 32 ° 0.12 0.45 Not coated 77 ° 0.5 0.5 Surprisingly enough, the coating of this Example 2 appeared to be more durable than that in Example 1, since there was only a gradual reduction in lubricity. In addition, the coated tube showed no apparent reduction in lubricity during the initial stage of the abrasion test. Therefore, the data of this Example 2 demonstrate, quite surprisingly, that the presence of the carboxylic acid groups that were present as a result of hydrolysis of the anhydride group in the binder polymer improved the abrasion resistance of the coating compared to the coating of Example 1, which contained a vinyl residue but no carboxylic acid residue.

Example C-3 Two pieces of PVC endotracheal tubes were cleaned with a thin paper containing IPA, air dried and subsequently immersed in a 2 weight percent PVP solution in diacetone alcohol for 5 minutes. The tubes were dried in a forced air oven at 90 ° C for 2.5 hours. The finished coating was lubricky but muddy. The lubricity was quickly lost on contact and essentially all the coating was removed from the tubes after abrasion.

Sample Angle of Friction Coefficient Contact Before After Abrasion Abrasion C-3 14 ° 0.05 0.21 Not coated 80 ° 0.25 0.25 Example C-4 Example C-3 was repeated with the exception that a coating solution containing 0.2 weight percent resin I of vinyl chloride in diacetone alcohol was used. The finished coating showed a moderate increase in hydrophilicity but was not lubricious in water. The abrasion resistance test was not carried out.

Sample Angle of Friction Coefficient Contact Before abrasion C-4 58 ° 0.25 Not coated 80 ° 0.25 Examples C-3 and C-4 illustrate that neither a hydrophilic polymer nor a vinyl polymer is sufficient to provide an adherent lubricious reverberation.

Example 5 - 2í Two PVC drain pipes with IPA were cleaned and dried in the air. The cleaned tubes were immersed in a 1 weight percent solution of carboxyl resin and vinyl chloride in ethyl acetate for 30 seconds followed by drying in a forced air oven at 90 ° C for 30 minutes. The dried tubes were then immersed in a 1 weight percent solution of PVP in a water / IPA mixture (57/43 weight percent) for 30 seconds and followed by drying in a 90 ° C forced air oven. for 1 hour ("hr"). The finished coating was uniform, optically crystalline both in the dry and hydrated state and very lubricious when exposed to water. The contact angles with water were measured as being 66 ° and 10 ° for the uncoated and coated tubes showing a high degree of hydrophilicity of the coated surfaces. The coefficient of friction measured in the presence of water for the uncoated and coated tubes was 0.32 and 0.15 respectively, showing a significant reduction in friction. The wet tubes were subsequently abraded against an elastomer washer for 100 times and the coefficient of friction was re-measured. The value was 0.21 which was still considerably lower than that of the uncoated tubes.

Example 6 Example 5 was repeated with the exception that a 2 weight percent PVC solution was used instead of a 1 weight percent solution. The finished or finished coating was uniform, optically crystalline and lubricious during hydration. The contact angle measured in water was 13 °. The coefficient of friction before and after 100 abrasions was found to be 0.15 and 0.19, respectively.

Example 7 Example 5 was repeated with the exception that a 0.5 weight percent solution of resin-II carboxyl and vinyl chloride in ethyl acetate and a 2.5 weight percent solution of PVP in a mixture of IPA / Diacetone alcohol (50/50 weight percent). The finished and uniform coating, optically crystalline and libricious during hydration. The contact angle measured with water was 35 ° and the coefficient of friction measured before and after 100 abrasions was 0.03 and 0.09, respectively.

Example 8 Sections of the Tygon pipe were cleaned with IPA and air dried. Pipe sections were immersed in a 1 weight percent solution of carboxyl-vinyl chloride-I resin in ethyl acetate for 30 seconds followed by drying in a forced air oven at 90 ° C for 30 minutes. The pipe sections were then immersed in a 0.5 percent by weight cationic HEC cationic solution (mixture of 50/50 weight percent of cationic HEC1 and cationic HEC2) in a solvent mixture consisting of 95/5 percent by weight. water weight / IPA for 30 seconds and followed by drying at 90 ° C for one hour. The finished coating was uniformly optically crystalline in both the dry and wet state and very lubricious during hydration. The contact angles with water for the uncoated and coated pipe were 76 ° and 10 ° respectively showing a high degree of hydrophilicity of the coated surfaces. The coefficient of friction before and after 100 abrasions for the uncoated and coated pipe was found to be 0.68 / 0.68 and 0.1 / 0.3, respectively.

Example 9 IPA was cleaned and air-dried, 30.48 cm sections of a polyethylene probe. The probes were immersed in a 1 weight percent solution of carboxyl-I resin and vinyl chloride in ethyl acetate for 30 seconds, followed by drying in a forced air oven at 65 ° C for one hour. The probes were subsequently submerged in a 0.5 weight percent cationic HEC solution (composition as used in Example 8) for 30 seconds and followed by drying in a forced oven at 65 ° C for two hours. The coating was uniform and smooth. The coefficient of friction for the uncoated and coated probes was measured as being 0.86 and 0.27, respectively.

Example 10 Polyethylene balloons were cleaned with IPA and air dried. The balloons were then coated with a 1 percent solution of carboxyl resin I and vinyl chloride in ethyl acetate submerged for 30 seconds. The balloons were allowed to dry in a forced air oven at 65 ° C for one hour and subsequently submerged in a 0.5 percent cationic HEC solution (same composition as used in Example 8) for 30 seconds. This was followed by drying at 65 ° C for 2 hours in a forced air oven. The coatings obtained were smooth and very lubricious when wet. A coated balloon was immersed in a solution containing 500 units per milliliter of heparin for 1 minute and air dried. The presence of immobilized heparin in the coating was confirmed by infrared spectroscopy.

Example 11 PET balloons were cleaned with IPA and air dried. The balloons were then coated with a 1 weight percent solution of the carboxy-vinyl chloride-I resin in ethyl acetate by submerging for 1 minute. The balloons were allowed to dry in a forced air oven at 75 ° C for 30 minutes and then subsequently submerged in a 0.5 percent cationic HEC solution (composition equal to that used in Example 8) for one second. This was followed by drying for one hour in a forced air oven at 75 ° C. The coatings obtained were smooth and very lubricious when wet. A coated balloon was immersed in a solution containing 500 units per milliliter of heparin for 1 minute and air dried. The presence of heparin immobilized in the coating was confirmed by infrared spectroscopy.

Examples 12 - 13 A 1 weight percent solution of carboxyl-vinyl chloride I-resin in diacetone alcohol was prepared by mixing in a Waring blender for about 10 minutes to provide a crystalline solution having a Brookfield viscosity of 8 centipoise ("cP" ). A 2.5 weight percent solution of PVC in diacetone alcohol was prepared in the same manner to provide a crystalline solution having a Brookfield viscosity of 36 centipoise. The two solutions were combined in weight ratios of 2/1 and 4/1 to yield solutions containing different ratios of the two polymers: Solution Ratio of Total Percentage Viscosity PVP / Resin-I of solids Brookfiel, cP A 2/1 2.0 25 B 4/1 2.2 30 Four pieces of PVC endotracheal tubes were cleaned with IPA and air dried. Two tubes were immersed in solution A for 30 seconds and followed by drying in a forced air oven at 90 ° C for 2.5 hours. The other two tubes were immersed in solution B for 30 seconds and followed by drying at 90 ° C for 2.5 hours. The finished tubes were uniform, optically crystalline both in the dry and wet state and very lubricious during hydration. The surface characterizations provided the following results: Solution Angle of contact Coefficient Coefficient Used with friction friction water After abrasion (100 times) Uncoated 80 0.25 0.25 A 30 0.14 0.17 B 22 0.09 0.11 Examples 14 to 18 The one-step coating solutions of the carboxyl-vinyl chloride-I resin and PVP, at a total 2.2 percent solids in diacetone alcohol were prepared in a rolling mill at varying polymer ratios as shown below: PVP / Resin-I Solution% Total Viscosity Solids Brookfield cP 1 4/1 2.2 30 2 5/1 2.2 29 3 7/1 2.2 32 10/1 2.2 34 the PVC endotracheal tubes were coated with the aforementioned solutions according to the following procedure. The tubes were cleaned with IPA and allowed to air dry for 10 minutes. Then a pair of tubes were immersed in each of the above solutions for a specified period of time (which will be indicated below) and subsequently dried in a forced air oven at 90 ° C for 2.5 hours. Lubricity, before and after 100 abrasions with a silicone elastomer washer, from the tubes coated, was characterized by measuring the coefficient of friction in the presence of water. In addition, the contact angle was also measured and showed a high degree of hydrophilicity for the coated tubes.

Example Solution Angle Coefficient Time Immersion, Conic Touch Friction ° Before After Abrasion Abrasion 14 1 5 0.07 0.08 22 2 0.5 0.09 0.14 22 16 3 2.45 0.09 0.08 22 17 4 0.5 0.09 0.07 23 18 4 5 0.09 0.08 25 Uncoated tube 0.25 0.25 Example 19 A one-step resin-coated coating fluid of carboxyl and vinyl chloride-III resin and PVP was prepared in water at a total solids content of 2.2 percent in an aqueous medium containing 80 percent diacetone alcohol and 20% alcohol. percent of water. The relationship between PVP and vinyl resin was 10: 1. The dispersion was uniform and slightly turbid and showed a Brookfield viscosity of 45 centipoise. Two pieces of the PVC endotracheal tubes were coated according to the same procedure described in Example 14 with a 5 minute immersion in the coating solution followed by drying at 90 ° C for 1.5 hours. The coating was crystalline and uniform and was characterized using the same methods described in Example 14.

Sample Friction Coefficient Angle Contact, ° Before Abrasion After Abrasion Not coated 80 0.25 0.25 23 0.05 0.06 Example 20 A waterborne coating formulation was prepared by mixing the carboxyl-vinyl chloride resin-III and PVP in a mixture of butyl glycol ether, diacetone alcohol, and water to provide the following composition: % in weigh Carboxyl and vinyl chloride resin-III 0.4 percent PVP 4 percent Butylglycol ether 20 percent Diacetone alcohol 20 percent Water 55.6 percent Viscosity Brookfield, cP 89 The two pieces of PVC endotracheal tube were immersed in the aforementioned solution for 5 minutes and dried in a forced air oven at 90 ° C for 1.5 hours. The finished coating was uniform. The contact angle with water was 44.7 °, and the coefficient of friction in the presence of water was measured as being 0.03 and 0.07 after 100 abrasions with an elastic membrane. The non-coated PVC endotracheal tube showed corresponding values of 80 °, 0.25, and 0.25, respectively.

Example 21 Two pieces of Tygon tube were coated according to Example 14 with the exception that the Carboxyl resin-I and vinyl resin was replaced with a copolymer of vinyl acetate and low molecular weight acrylic acid (99.2 weight percent vinyl acetate / 0.8 weight percent acrylic acid). The coated tubes were lubricous and showed a COF before and after 100 abrasions of 0.25 and 0.36, respectively. The uncoated tube showed a COF of 0.51. The contact angle with distilled rinsing for the coated and uncoated tubes was 10 and 77 °, respectively. Although the invention has been described above with respect to specific aspects, those skilled in the art will recognize that it is intended to include other aspects within the scope of the claims that will be given below. For example, polymers other than binding polymers and specific hydrophilic polymers can be employed according to the present invention. In addition, other carboxylic acids such as for example carboxylic acids substituted with halides such as chloroacetic acids or amino acids can be used instead of the specific carboxylic acids disclosed. Also, in addition to the specific vinyl residues noted above, other vinyl residues such as those found in compounds such as benzene may be used in accordance with the present invention. of vinyl, vinyl toluene, methyl methacrylate and acrylonitrile.

Claims (10)

CLAIMS;

1. In a lubricious coating applied to a surface of a substrate comprising: (i) a hydrophilic polymer that is essentially more lubricous when moistened with an aqueous liquid than when it is dry; and (ii) a binder polymer that is capable of bonding to the surface of the substrate and the hydrophilic polymer, the improvement wherein the binder polymer is a copolymer comprising a vinyl residue and a carboxylic acid residue.

2. The lubricious coating according to claim 1, wherein the binder polymer is a copolymer of vinyl chloride, vinyl acetate and carboxylic acid.

3. The lubricant coating according to claim 1, wherein the substrate is selected from the group consisting of polyurethane, polyvinyl chloride, polyacrylate, polycarbonate, polystyrene, polyester resins, copolymers of polybutadiene and styrene, nylon, polyethylene, polypropylene , polybutylene, silicon, polyvinyl acetate, polymethacrylate, polysulfone, polyisoprene, copolymers and derivatives thereof, glass, metal, ceramics and mixtures thereof.

4. The lubricious coating according to claim 1, wherein the hydrophilic polymer is selected from the group consisting of polyvinyl compounds, polysaccharides, polyurethanes, polyacrylates, polyacrylamides, polyalkylene oxides and complex copolymers, derivatives and mixtures thereof.

5. The lubricous coating according to claim 1, further comprising an additive that is selected from the group consisting of therapeutic agents, antithrombogenic agents, antimicrobial agents, antibiotics, and mixtures thereof.

6. A biomedical device comprising the lubricious coating according to claim 1.

7. The biomedical device according to claim 6 which is selected from the group consisting of probes, guide wires, extenders, expansion balloons, endotracheal tubes , instruments and grafts.

8. In a process for applying a lubricous coating to a surface of a substrate comprising contacting the surface with: (i) a hydrophilic polymer that is considerably more lubricious when moistened with an aqueous liquid than when it is dry; Y (ii) a binder polymer that is capable of bonding to the surface of the substrate and the hydrophilic polymer; the improvement wherein the binder polymer is a copolymer comprising a vinyl residue and a carboxylic acid residue.

9. The process according to claim 1, wherein the surface contacts a first liquid medium comprising the binder polymer and is subsequently contacted with a second liquid medium comprising the hydrophilic polymer. The process according to claim 1, wherein the surface is contacted with a common liquid medium comprising the binder polymer and the hydrophilic polymer.