Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D5/00—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
  • B05D5/08—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures to obtain an anti-friction or anti-adhesive surface
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L29/00—Materials for catheters, medical tubing, cannulae, or endoscopes or for coating catheters
  • A61L29/08—Materials for coatings
  • A61L29/085—Macromolecular materials
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/0427—Coating with only one layer of a composition containing a polymer binder
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/043—Improving the adhesiveness of the coatings per se, e.g. forming primers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/046—Forming abrasion-resistant coatings; Forming surface-hardening coatings
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D139/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a single or double bond to nitrogen or by a heterocyclic ring containing nitrogen; Coating compositions based on derivatives of such polymers
  • C09D139/04—Homopolymers or copolymers of monomers containing heterocyclic rings having nitrogen as ring member
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2439/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a single or double bond to nitrogen or by a heterocyclic ring containing nitrogen; Derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L75/00—Compositions of polyureas or polyurethanes; Compositions of derivatives of such polymers
  • C08L75/04—Polyurethanes

Definitions

• Article having a low-friction surface coating Method of preparing said article and coating composition for use in the method
• the present invention relates to an article having a low-friction surface coating when wetted which coating essentially consists of polyurethane without free isocyanate groups and poly (N-vinyl lactam).
• the invention relates to plastics articles for medical use and in particualr catheters with a lowfriction coating of the above mentioned type.
• a low-friction coating on e.g. a catheter provides the catheter with a slippery and lubricating surface when dipped into an aqueous, optionally saline, solution prior to the insertion into a body cavity or when contacted with an aqueous body liquid upon insertion into the body cavity.
• an aqueous, optionally saline, solution prior to the insertion into a body cavity or when contacted with an aqueous body liquid upon insertion into the body cavity.
• Low-friction coatings based on polyurethane and poly (N-vinyl lactam) are known from i.a. GB patent specification No. 1.600.963 and US patent specifications Nos. 4,666,437 and 4,642,267.
• the latter US patent specification describes a low-friction polymer blend for use in low-friction coatings for a number of basic materials.
• the polymer blend essentially consists of an organic, soluble, pre-formed thermoplastic polyurethane without reactive isocyanate groups and a hydrophilic poly (N-vinyl lactam) which blend tolerates the influence of water without loss of the hydrophilic poly (N-vinyl lactam).
• said patent specification discloses a method of providing the surface of a plastics material with a low-friction coating. In the known method two polymers are dissolved in a mixture of diacetone alcohol and methyl ethyl ketone followed by the evaporation of the solvent after the solution has been appl ied to the surface of the plastics article.
• the resulting coating is stated to be stable and not to decompose even after prolonged continuous contact with water.
• said known coating may seem stable when contacted with static water, but in practice it appears that said coating is easily rubbed off the coated plastics article when the article during use is exposed to friction.
• Coatings prepared as described in the above mentioned US patent specification do not adhere well to the surface of materials which are applied in practice, e.g. softened PVC and polyurethane rubber. Neither do the coatings have a fully satisfactory low-friction effect when located on the surface of the materials of the above mentioned type.
• the article of the invention is characterized in that the coating is a two-phase coating, that polyurethane and poly (N-vinyl lactam) each form a separate phase and that poly (N-vinyl lactam) primarily forms the inner phase of the two-phase structure.
• the above mentioned two-phase structure exhibits the special property that it is limpid in dry condition and milky white when wetted and that the milky wetted coating can be converted to a dry l impid coating by drying.
• the milky appearance in wetted condition is presumably due to the fact that water is absorbed by the discontinuos phase of hydrophilic poly (N-vinyl lactam).
• the state resulting from such water absorption is stable and reversible and as mentioned above it is possible to produce a dry limpid coating again by drying the wetted coating.
• polyurethanes based on e.g. sorbitol and prepared by using trifunctional isocyanates are not suitable for use in the coatings nor are thermoplastic polyurethanes prepared by reacting equivalent amounts of polyether polyols with difunctional diisocyanates.
• polyurethanes prepared from a polyester polyol and a difunctional isocyanate in which isocyanate is used in an amount equivalent to or less than the equivalent amount in order to avoid free isocyanate groups are suitable for use according to the invention.
• Particularly preferred polyurethanes are prepared from polyester polyol based on butane diol and adipic acid. Furthermore, it has been found that the polyurethane should be crystalline i.e. have a crystallinity corresponding to a Shore A hardness of the polyurethane of at least 80. Polyurethanes having a Shore A hardness of above 90 are particul arly preferred. Such highly crystalline polyurethanes are particularly suitable in coatings for articles made from PVC, because said polyurethanes are unaffected by the plastizicers contained in the PVC.
• the polyurethane should have a relatively high molecular weight.
• the polyurethane contained in the coating should have a molecular weight corresponding to a viscosity of a 15% solution of methyl ethyl ketone of at least 300 cp, and preferably of 500-5000 cp.
• crystallinity Shoore A hardness
• molecular weight solution viscosity
• a relatively low molecular weight may be compensated for by selecting a polyurethane of a higher crystallinity.
• a polyurethane of a relatively low crystallinity may be chosen provided it has a relatively high molecular weight.
• the poly (N-vinyl lactam) contained in the coating is preferably polyvinylpyrrol idone and in particular a polyvinylpyrrolidone having a k-value of above approx. 50.
• Homopolymers of N-vinylbutyrolactam and N-vinylcaprolactam as well as copolymers of N-vinylpyrrolidone, N-vinylbutyrolactam and/or N-vinylcaprolactam are examples of other suitable polymers in the above mentioned group.
• the coated article is preferably a plastics article or an article having a surface layer of plastics.
• Preferred plastics are PVC and polyurethane.
• catheters such as e.g. urethra! catheters
• Other articles, e.g. guide wires, used for inserting catheters into body cavities and comprising a plastics coating may also advantageously be provided with a coating as described above.
• the invention also relates to a method of preparing an article as described above wherein a coating composition comprising a mixture of polyurethane, poly (N-vinyl lactam) and at least two solvents of different volatility is applied to at least a part of the surface of the article, followed by the evaporation of the solvents, the method being characterized in using such a solvent system that the polyurethane is soluble in at least the mixture of solvents and in the least volatile solvent, and that the poly (N-vinyl lactam) is soluble in the most volatile solvent but only partly soluble in the least volatile one.
• poly (N-vinyl lactam) precipitates during the evaporation of solvent while the polyurethane is still dissolved.
• a solvent system comprising two mutually miscible solvents is preferably used.
• phase structure consists of domains which preferably contain polyvinylpyrrolidone, optionally with bordering zones, which mainly consist of a polyvinyl pyrrol idone polyurethane complex distributed in a matrix which mainly consists of polyurethane.
• the domains of poly (N-vinyl lactam) present in the two-phase structure preferably have a size of about 400 nanometers.
• the formation of the two-phase structure is influenced by the ratio of the amount of polyurethane to the amount of poly (N-vinyl lactam).
• the ratio of poly (N-vinyl lactam) to polyurethane is relatively high. Therefore, a weight ratio of from 1.5:1 - 5:1, especially 2:1 - 3:1, is preferred, and particularly preferred is a ratio about 2.5:1.
• the Hansen Solubility Parameters comprise a set of three parameters of a solvent defining the polarity of the solvent, the capability of the solvent to form hydrogen bonds and the dispersion forces. These parameters express the ability of the solvent to mix with other solvents and the ability to dissolve other substances. Polymers may also be described by means of the Hansen Solubility Parameters, and by knowing these parameters it is possible to predict their solubility.
• solubility parameters of a number of solvents are disclosed in Allan F.M. Barton: CRC Handbook of Solubility Parameters and Other Cohesion Parameters. CRC Press Inc. Boca, Raton, Florida, 1983. If e.g. methylene chloride is chosen as the solvent in which both polyurethane and polyvinylpyrrol idone are soluble, the other relatively volatile solvent should have an R-value which is higher than or equal to 19, and preferably higher than or equal to 19.5. The above mentioned R-value defines the distance of the solvent from the centre of the solubility sphere of polyvinylpyrrol idone in a three-dimensional space and it is calculated as stated on page 152 of the above reference.
• Catheters having a low-friction coating when wetted are typically prepared from a long plastics tubing which is cut into pieces of a suitable length. These pieces are then formed into catheter tubings by making the one end pointed and by e.g. attaching a catheter funnel to the catheter by gluing. Finally, the catheters thus prepared are dipped into a liquid coating agent so as to provide them with a low-friction coating.
• the surface coating formed by the method of the invention has surprisingly proved to be heat stable and adhesive to such an extent that a tubing provided with s coating may be converted to medical products e.g. catheters
• the invention relates to a coating composition for use in the method described above.
• the coating composition comprises a mixture of polyurethane, poly (N-vinyl lactam) and at least two solvents of different volatility and is characterized in that the solvents are selected in such a manner that the polyurethane is soluble in both solvents, and that the poly (N-vinyl lactam) is soluble in the most volatile solvent but only partly soluble in the least volatile solvent.
• Solutions of various polyurethanes (PUR) for use in combination with polyvinylpyrrol idone (PVP) are prepared with the object of providing PVC catheters with a coating.
• the quality of the coating is visually graded with regard to the transparency of the film, adherence in dry and wet condition and friction in wet condition.
• the following grades are used based on the standard deviation of the present tests:
• coating may be rubbed off in layers or in spots 4. may be rinsed off in running water
• Example 8 shows that a polyurethane having a too low viscosity (i.e. mole weight) does not adhere satisfactorily.
• Example 11-28 shows that a polyurethane having a too low viscosity (i.e. mole weight) does not adhere satisfactorily.
• PUR is Irostic 160/38 from Iromer.
• Series B uses Estane 5703 from B.F. Goodrich.
• Irostic 212K from Iromer is used in example 24.
• Coated PVC catheters are prepared and they are followed by a grading as to transparency in dry condition and adherence in wet condition.
• Examples 21 and 22 show that the absence of a solvent to control the precipitation of a separate PVP phase during evaporation causes poor adherence.
• a standard solution of a polyurethane based on a polyether polyol is prepared (Tecolflex 80A from Thermedics Inc.) and PVC tubes are coated by dipping in the solution and are dried. After drying the coating is uniform and has a dull surface. When wetted it becomes slippery but adheres very poorly and after about 10 sec. in running water the coating is rinsed off.
• the friction of a number of catheters in wet condition is measured by means of an apparatus consisting of a fixed support with a horizontal surface onto which a sliding zone is attached consisting of a medical lambskin having the dimensions 1.5 x 3.0 cm.
• a metal block having an underside which is provided with two transverse grooves with two short pieces of catheters mounted in said grooves may be drawn longitudinally of said sliding zone.
• the block is connected with a pull device which produces a horizontal force which increases by 25 g/min.
• the block weighs 70 g. When measuring, the catheter pieces and the lambskin are wetted and the block is placed at one end of the sliding zone.
• the load is increased until the block begins to move.
• the load at the point of movement defines the friction.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Materials Engineering (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Epidemiology (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Materials For Medical Uses (AREA)
• Paints Or Removers (AREA)

Applications Claiming Priority (2)

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• 1988
  • 1988-11-02 DK DK611588A patent/DK165415C/da not_active IP Right Cessation
• 1989
  • 1989-11-02 AU AU45257/89A patent/AU4525789A/en not_active Abandoned
  • 1989-11-02 EP EP89912624A patent/EP0453443A1/de not_active Withdrawn
  • 1989-11-02 WO PCT/DK1989/000255 patent/WO1990005162A1/en not_active Ceased

Non-Patent Citations (1)

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