Medical and non-medical devices made from hydrophilic rubber materials

Abstract

This invention relates to medical, health care and non-medical devices comprising a rubbery or elastomeric polymer material taking up more than 5% by weight of water and at most 500% by weight of water after immersion in demineralized water at room temperature for a sufficient time to reach saturation. The material may be in the form of a foam, or in the form of a coating adapted for adhesion to a substrate, or in the form of a sheet, or in the form of a fiber, and may comprise: —repeating units from one or more hydrophobic organic monomers, and —repeating units from one or more monomers (a) being modified with one or more hydrophilic side groups.

Claims

1. An aqueous fluid absorbing, medical or health care device, comprising: a rubbery or elastomeric polymer material effective to take up more than 40% by weight and up to 500% by weight of water after immersion in demineralized water at room temperature for a sufficient time to reach saturation, of the formula I: ##STR00004## wherein, R is Si(CH.sub.3).sub.3 or hydrogen, n is from 3 to 28, and (m+o+1) is at least 5 and less than 1,000, said polymer material, comprising: (a) repeating units from one or more hydrophobic organic monomers; (b) repeating units from the one or more monomers being modified with C.sub.3-28 alkylsulfonate or alkenylsulfonate side groups in association with a cation selected from the group consisting of ammonium, Li, Na and K, Ca and Mg, and the repeating units (b) constituting from 1% to 30% of a total number of repeating units (a) and repeating units (b); and a detectable trace of a ligand selected from the group consisting of crown ether, cryptand and calixerene, wherein, said device is a medical or health care device selected from the group consisting of tight seals for adjusting to a part of the human face, nasal plugs, ear plugs, sterile bandages, medical cotton, absorbent pads, catheters, balloons, medical tubings, prosthetic implants, orthotic devices, orthodontic devices, medical and surgical wipes, bed sore protection devices, transdermal patches, delivery devices for non-charged polar drugs and positively or negatively charged drugs, anti-scarring plasters, body contact bands, hair care products, and biocompatible devices for medical diagnosis or treatment.

2. A medical device according to claim 1, wherein said rubbery or elastomeric polymer material is for contact with the skin or a mucosa of a human.

3. A device according to claim 1, wherein said rubbery or elastomeric polymer material is in the form of a sheet.

4. A device according to claim 1, wherein said rubbery or elastomeric polymer material is in the form of a foam.

5. A device according to claim 4, wherein the density of said foam is from 60 to 300 kg/m.sup.3.

6. A device according to claim 1, wherein said rubbery or elastomeric polymer material is in the form of a coating adapted for adhesion to a substrate.

7. A device according to claim 1, wherein said rubbery or elastomeric polymer material is in the form of a fiber.

8. The device according to claim 1, wherein said rubbery or elastomeric polymer material is prepared by a method, comprising: mixing together silicone precursor, sodium C.sub.3-28 alkylsulfonate or alkenylsulfonate, and ligand.

9. The device according to claim 8, wherein said silicone precursor, comprises: a first component having silicone prepolymer with reactive vinyl groups and metal catalyst; and a second component having silicone prepolymer with reactive vinyl groups and prepolymer having Si—H groups.

10. The device according to claim 8, wherein the sodium C.sub.3-28 alkylsulfonate or alkenylsulfonate comprises sodium C.sub.12-14 alkenyl sulfonate.

11. The device according to claim 8, wherein the ligand is 15-crown-5 ether.

12. The device according to claim 8, wherein the method, comprises: mixing 40 to 98.5% by weight of the silicone precursor with 1 to 30% by weight of the sodium C.sub.3-28 alkylsulfonate or alkenylsulfonate, and up to 30% by weight of the ligand to form a mixture.

13. An aqueous fluid absorbing, non-medical or non-health care device, comprising: a rubbery or elastomeric polymer material effective to take up more than 40% by weight and up to 500% by weight of water after immersion in demineralized water at room temperature for a sufficient time to reach saturation, of the formula I: ##STR00005## wherein, R is Si(CH.sub.3).sub.3 or hydrogen, n is from 3 to 28, and (m+o+1) is at least 5 and less than 1,000, said polymer material, comprising: (a) repeating units from one or more hydrophobic organic monomers; (b) repeating units from the one or more monomers being modified with C.sub.3-28 alkylsulfonate or alkenylsulfonate side groups in association with a cation selected from the group consisting of ammonium, Li, Na and K, Ca and Mg, and the repeating units (b) constituting from 1% to 30% of a total number of repeating units (a) and repeating units (b); and a detectable trace of a ligand selected from the group consisting of crown ether, cryptand and calixerene.

14. A non-medical device according to claim 13, being selected from the group consisting of external and in-ear head sets, ear clips, nose and/or ear pieces of glasses, handles, textile and non-textile parts of shoes, building elements made of metal or plastic, parts of boats, printing stamps, clothing textiles, cosmetic compositions, printing inks, toner compositions, paint or coating compositions, surfactant compositions, antifoaming agents, rolling oil formulations, wafer bonding agents, anti-statics, developers for lithographic plates, artificial sponges, anti-fog agents, non-woven articles, body contact belts and bands, seats, highly reflective products, sliding transportation systems, sliding sealing rings, and oil barriers in silicone rings.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will now be described, by way of example, with reference to the accompanying drawings, in which

(2) FIG. 1 and FIG. 2 show the water uptake of different hydrophilic silicone rubber materials (wherein the term “soap” is used as an abbreviation to designate sodium sulfonate groups) as a function of time, in comparison with a hydrophobic silicone rubber material without alkylsulfonate groups.

(3) The exemplification set out herein illustrates exemplary embodiments of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.

DEFINITIONS

(4) Hydrophobic materials are characterized by a water contact angle that is larger than that of hydrophilic materials. The larger the contact angle, the more hydrophobic is the material, the smaller the contact angle, the more hydrophilic is the material.

(5) Examples of hydrophobic materials as used in the present invention are silicone rubbers, natural rubbers (latex), rubbers based on butadiene, isoprene, halogenated butadiene, perfluorinated rubbers (Viton) and acrylate rubbers, and mixtures thereof.

(6) Hydrophilic materials are defined herein as polymers that allow the uptake and/or diffusion of water.

(7) Examples of hydrophilic rubber materials include, but are not limited to, hydrophilic silicone rubbers with a crosslinking structure and/or a crosslinking density similar to that of hydrophobic silicone rubber materials. Hydrophilic silicones keep the silicone backbone structure but some of their hydrophobic methyl or phenyl groups are replaced with hydrophilic side groups.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

(8) The present invention is described herein with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Where an indefinite or definite article is used when referring to a singular noun e.g. “a” or “an”, “the”, this includes a plural of that noun unless something else is specifically stated.

(9) The term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

(10) Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

(11) Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

(12) In an embodiment in accordance with the present invention, a composition for the preparation of hydrophilic silicone materials suitable for moisture control, and being in bulk or in the form of coatings, is provided.

(13) The synthesis of a suitable hydrophilic silicone according to this invention by two different cross-linking methods may be schematically described as follows:

(14) ##STR00002##
Platinum salt catalyzed crosslinking, and

(15) ##STR00003##
Peroxide Crosslinking

(16) A silicone precursor bearing reactive Si—H or Si-vinyl groups reacts with a hydrophilic monomer such as an alpha-olefin sulfonate, wherein:

(17) the values for n and m may range from 3 to 28, preferably from 10 to 18, and more preferably from 12 to 16, and

(18) wherein the value for o ranges from 5 to 1,000.

(19) The olefin component may be strongly hydrophilic, because it may include a polar, negatively charged head group (.sup.−O.sub.3S) and a cation (M.sup.n+) for charge balance. The mixing of the hydrophilic olefin component with the hydrophobic silicone precursor may be hampered by the difference in hydrophilicity. It may be particularly different to suspend the ion pair composed of the anionic head group and the cationic counter-ion in the hydrophobic matrix of the silicone precursor.

(20) Adding a crown ether acting as a solubility- or mixing mediator may be highly effective and may allow for a simple, rapid, and highly reproducible synthesis of the desired hydrophilic silicone material. The choice of the most suitable crown ether may depend on the counter-cation used. For instance, the most efficient solubility mediator for dissolving the sodium ions in hydrophobic media is the 15-crown-5 ether, whereas the most suitable solubility mediator for dissolving potassium ions in hydrophobic media is the 18-crown-6 crown ether. The stabilization of metal ions in hydrophobic media by crown ethers, derivatives thereof, and related molecules, is well known in the art and has been described for instance in the following publications, the content of which is incorporated herein by reference: H. J. Schneider et al., Chemical Society Reviews (2008) 37, 263-277; Barannikov, Russian Journal of Coordination Chemistry (2002) 28, 153-162; and J. W. Steed, Coordination Chemistry Reviews (2001) 215, 171-221; and references therein.

(21) In an exemplary embodiment in accordance with the present invention, mixing a commercial silicone precursor material with a sodium alpha-olefin sulfonate may be facilitated by the addition of a crown ether mixing mediator. Sodium alpha-olefin sulfonates, such as sodium C.sub.12-14 olefin sulfonate, sodium C.sub.14-16 olefin sulfonate, sodium C.sub.14-18 olefin sulfonate, or sodium C.sub.16-18 olefin sulfonate, are mixtures of long chain sulfonate salts prepared by the sulfonation of alpha olefins. The numbers indicate the average length of the carbon chains of the alpha olefins. Other ligating compounds that may be suitable to form an inclusion complex with the chosen counter ion may be used as an alternative to crown ethers. An example of such compounds are calix[4]arenes as described in B. S. Creaven et al., Coordination Chemistry Reviews (2009) 253, pp. 893-962, the content of which is incorporated herein by reference.

(22) The water-absorbing rubbery or elastomeric polymer material present in the medical, health care or non-medical device with high water-uptake capacity of the present invention may be in the form of a coating adapted for adhesion to a substrate. The substrate may be a piece of another polymer material or a piece of metal such as aluminum or steel or other metal alloys as used for instance in the building industry. The substrate may have any shape such as planar, curved, spherical or other, depending upon the type of device, as long as good adhesion is obtained.

(23) The water-absorbing rubbery or elastomeric polymer material present in the medical, healthcare or non-medical device with high water-uptake capacity of the present invention, such as a textile, may be in the form of a fiber or fibrous material. Manufacture of silicone fibers such as used as fillers in polyester pillows, in particular hollow silicone fibers with a linear mass density from 1.5 to 25 deniers, are well known to the skilled person.

(24) The following examples are purely illustrative of specific embodiments and should not be construed as limiting the scope of the present invention.

Example 1

(25) The commercial silicone elastomer Elastosil LR 3004/40 (Wacker Silicones, Germany) was used as silicone precursor material. The silicone precursor material is a two component system that was mixed in a 1:1 weight ratio of two components A and B. The A component consists of a silicone pre-polymer bearing reactive vinyl groups and a platinum catalyst. The B component consists of a silicone pre-polymer bearing reactive vinyl groups and a pre-polymer bearing Si—H groups.

(26) The sodium C.sub.12-14 alkenyl sulfonate commercially available from The Chemistry Store.com (Cayce, S.C., United States) was first mixed with the A component of the silicone precursor material. This mixing process is generally energy-demanding as the two components are viscous and do not mix well. Heating to 120° C. may therefore be needed.

(27) To facilitate mixing of the commercial sodium C.sub.12-14 alkenyl sulfonate with the silicone precursor A component, a crown ether (15-crown-5) was used (10% w/w with respect to the total amount of components A and B) as a mixing mediator. After addition of the crown ether, mixing was found to be straight forward and easily accomplished at room temperature.

(28) More specifically, the commercial sodium alpha-olefin sulfonate (2 g) was mixed with 15-crown-5 (2 g) and silicone precursor A component (10 g). Mixing was performed at room temperature (SpeedMixer™ DAC 150 FVZ-K, Hauschild, Germany, twice 2 minutes, 3300 rpm). Then silicone precursor B component (11.4 g) was added and the obtained composition was mixed again (same mixer, twice 2 minutes, 3300 rpm). The resulting silicone composition was thus comprised of 84% by weight of the commercial silicone precursor material, 8% by weight of a commercial sodium alpha-olefin sulfonate, and 8% wt of the mixing mediator 15-crown-S.

(29) Material samples were prepared by casting the above mixture onto the surface of a glass substrate and curing (30 minutes, 130° C.) under reduced pressure (<10 mbar). After curing, the water uptake of the silicone material (sample A) was compared with that of two other materials:

(30) a material sample that was made with 20% by weight of the sodium alpha-olefin sulfonate without crown ether (sample B), and

(31) a material sample that was made of the commercial silicone elastomer Elastosil 3004/40 according to the instructions of the manufacturer (sample C).

(32) After immersion of all three samples in demineralized water for 5 days, the Elastosil 3004/40 (sample C) had taken up 0.3% by weight water, the new silicone material comprising the sodium alpha-olefin sulfonate and the crown ether mixing mediator (sample A) had taken up 43% by weight water, whereas the sample B comprising only the sodium alpha-olefin sulfonate but no 15-crown-5 mixing mediator, had taken up 40% by weight water.

(33) Water uptake (weight %) as a function of time of different amounts of sodium C.sub.12-14 alkenyl sulfonate with equal amounts of 15-crown-5 in Elastosil LR3004/40 along the route described herein are shown in FIG. 1.

(34) In the following examples 2-5, the amount of commercial sodium C.sub.12-14 alkenyl sulfonate added to the amount of silicone precursors A+B is given in percentage and calculated along weight sodium C.sub.12-14 alkenyl sulfonate/weight silicone A+B*100. The values for the percentage silicone precursor A+B given in examples 2-5 are the values for 100%−amount sodium C.sub.12-14 alkenyl sulfonate %.

Example 2

(35) The commercial silicone elastomer Elastosil LR 3004/40 (Wacker Silicones, Germany) was used as silicone precursor material. The silicone precursor material is a two component system that was mixed in a 1:1 weight ratio of two components A and B. The A component consists of a silicone pre-polymer bearing reactive vinyl groups and a platinum catalyst. The B component consists of a silicone pre-polymer bearing reactive vinyl groups and a pre-polymer bearing Si—H groups.

(36) The sodium alpha-olefin sulfonate RCH═CH(CH.sub.2).sub.nSO.sub.3Na (n=12-14) commercially available from The Chemistry Store.com (Cayce, S.C., United States) with a particle size above 400 μm was first mixed with the A component of the silicone precursor material. This mixing process is generally energy-demanding as the two components are viscous and do not mix well. Heating to 120° C. may therefore be needed.

(37) To facilitate mixing of the commercial sodium alpha-olefin sulfonate with the silicone precursor A component, a crown ether (15-crown-5) acetone mixture was used as a mixing mediator. After addition of the crown ether and acetone mixing was found to be straight forward and easily accomplished at room temperature.

(38) More specifically, the commercial sodium alpha-olefin sulfonate (12 g) was mixed in a first step with 15-crown-5 (7 g) and 7 g acetone. After this the silicone precursor A component (19 g) was added. Mixing was performed at room temperature (Speed Mixer™ DAC 150 FVZ-K, Hauschild, Germany, twice 2 minutes, 3300 rpm). The crown ether and acetone were removed in vacuum at 0.05 mbar, 90° C. Then silicone precursor B component (26.1 g) was added and the obtained composition was mixed again (same mixer, twice 2 minutes, 3300 rpm). The resulting silicone composition was thus comprised of 73.4% by weight of the commercial silicone precursor material, and 26.6% by weight of the commercial sodium alpha-olefin sulfonate.

(39) Material samples were prepared by casting the above mixture onto the surface of a glass substrate and curing (30 minutes, 130° C.) under a nitrogen atmosphere.

Example 3

(40) In a further example the commercial silicone elastomer Elastosil LR 3004/40 (Wacker Silicones, Germany) was used as silicone precursor material. The silicone precursor material is a two component system that was mixed in a 1:1 weight ratio of two components A and B. The A component consists of a silicone pre-polymer bearing reactive vinyl groups and a platinum catalyst. The B component consists of a silicone pre-polymer bearing reactive vinyl groups and a pre-polymer bearing Si—H groups.

(41) A commercial sodium alpha-olefin sulfonate RCH═CH(CH.sub.2).sub.nSO.sub.3Na (n=12-14) from Stepan Company (Northfield, Ill., United States) was used. This very fine powder (particle sizes below 400 μm) was mixed with the A component of the silicone precursor material by speed mixing. More specifically, commercial sodium alpha-olefin sulfonate (12 g) was mixed with silicone precursor A component (19 g). Then silicone precursor B component (26.1 g) was added and the obtained composition was mixed. The resulting silicone composition was thus comprised of 73.4% by weight of the commercial silicone precursor material, and 26.6% by weight of a commercial sodium alpha-olefin sulfonate.

(42) Material samples were prepared by pressure molding at 130° C.

Example 4

(43) In a further example the commercial silicone elastomer Elastosil LR 3004/40 (Wacker Silicones, Germany) was used as silicone precursor material. The silicone precursor material is a two component system that was mixed in a 1:1 weight ratio of two components A and B. The A component consists of a silicone pre-polymer bearing reactive vinyl groups and a platinum catalyst. The B component consists of a silicone pre-polymer bearing reactive vinyl groups and a pre-polymer bearing Si—H groups.

(44) A commercial sodium alpha-olefin sulfonate RCH═CH(CH.sub.2).sub.nSO.sub.3Na (n=12-14) from Stepan Company (Northfield, Ill., United States) was used. 12 g of this very fine powder (particle sizes below 400 μm) was mixed with 7 g ethanol. Then 19 g of the A component of the silicone precursor material added and mixing was carried out with a speed mixer. After mixing the ethanol was removed under vacuum at 60° C. Then silicone precursor B component (26.1 g) was added and the obtained composition was mixed. The resulting silicone composition was thus comprised of 73.4% by weight of the commercial silicone precursor material, and 26.6% by weight of a commercial sodium alpha-olefin sulfonate.

(45) Material samples were prepared by pressure molding at 130° C.

Example 5

(46) In a further example the commercial silicone elastomer Elastosil LR 3004/40 (Wacker Silicones, Germany) was used as silicone precursor material. The silicone precursor material is a two component system that was mixed in a 1:1 weight ratio of two components A and B. The A component consists of a silicone pre-polymer bearing reactive vinyl groups and a platinum catalyst. The B component consists of a silicone pre-polymer bearing reactive vinyl groups and a pre-polymer bearing Si—H groups.

(47) A commercial sodium alpha-olefin sulfonate RCH═CH(CH.sub.2).sub.nSO.sub.3Na (n=12-14) from Stepan Company (Northfield, Ill., United States) was used. 12 g of this very fine powder (particle sizes below 400 μm) was mixed with 7 g of an ethanol water mixture (50/50% by volume). Then 19 g of the A component of the silicone precursor material added and mixing was carried out with a speed mixer. After mixing the ethanol was removed under vacuum at 90° C. Then silicone precursor B component (26.1 g) was added and the obtained composition was mixed. The resulting silicone composition was thus comprised of 73.4% by weight of the commercial silicone precursor material, and 26.6% by weight of a commercial sodium alpha-olefin sulfonate.

(48) Material samples were prepared by pressure molding at 130° C. Water uptake (weight %) as a function of time of different mixing methods of sodium C.sub.12-14 alkenyl sulfonate with Elastosil LR3004/40 along the above route described in examples 2-5 is given in FIG. 2.

Example 6

(49) In a 2.5 liter jacketed glass reactor, a mixture of 55 g butylmethacrylate (BMA) (purity above 99%), 2200 g water of a conductivity of 18.2 M□.Math.cm and 0.6 g of a commercial sodium alpha-olefin sulfonate RCH═CH(CH.sub.2)nSO.sub.3Na (n=12-14) from Stepan Company (Northfield, Ill., United States) are mixed and degassed under nitrogen while stirring at 500 rpm (using a double bladed stirrer). In order to reduce the chain length of the polymer, by controlling the micelle size of the BMA droplets in water, from 1 to 2% by weight of surfactant (e.g. sodium alpha-olefin sulfonate) is added to the monomer mixture. Then the reactor is put under nitrogen and the mixture is heated to 80° C. After addition of the initiator solution (for instance 1.6 g ammonium persulfate 98% in 50 g of water of a conductivity of 18.2 M□.Math.cm) at 80° C., the stirring speed is reduced to 350 rpm. Polymerisation is carried out for at least 3 hours.

Example 7

(50) In this example the commercial silicone elastomer Elastosil LR 3003/5 (commercially available from Wacker Silicones, Germany) was used as the silicone precursor material. The silicone precursor material is a two component system that was normally mixed in a 1:1 weight ratio of two components A and B. The A component consists of a silicone pre-polymer bearing reactive vinyl groups and a platinum catalyst. The B component consists of a silicone pre-polymer bearing reactive vinyl groups and a pre-polymer bearing Si—H groups. A commercial sodium alpha-olefin sulfonate RCH═CH(CH.sub.2).sub.nSO.sub.3Na (n=12-14) from Stepan Company (Northfield, Ill., United States) was used. 12 g of this very fine powder (particle sizes below 400 μm) was mixed with 7 g of an ethanol water mixture (50/50% by volume). Then 19 g of the A component of the silicone precursor material was added and mixed with a speed mixer. After mixing the ethanol and water were removed under vacuum at 60° C. until a small amount (±0.5 gram) of water was still present. Then silicone precursor B component (24.7 g) was added and the obtained composition was mixed. The commercial sodium alpha-olefin sulfonate added to the silicone precursors A+B, is thus amounting to 27.5 weight % of silicone precursor (A+B) weight ((weight sodium alpha-olefin sulfonate/weight silicone A+B)*100). The mixing ratio of this system for component A to B was 1 to 1.3. Material samples were prepared by pressure molding at 130° C. for 10 to 15 minutes at 711 psi.

(51) While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described herein. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.