ARTICLE COMPRISING A POLYMER LAYER

Abstract

There is provided an article comprising, a substrate having a charged surface; and a polymer layer on said substrate surface; wherein said polymer layer comprises, a crosslinked sublayer comprising charged moieties having a charge opposite to that of said charged surface; and a supra-layer comprising polymer chains grafted from the sublayer and extending away from said substrate surface. Preferably the polymer chains are polymer brushes.

Claims

1. An article comprising, a substrate having a charged surface; and a polymer layer on said substrate surface; wherein said polymer layer comprises, a crosslinked sublayer comprising charged moieties having a charge opposite to that of said charged surface; and a supra-layer comprising polymer chains grafted from the sublayer and extending away from said substrate surface, preferably wherein the polymer chains are polymer brushes.

2. The article of claim 1, wherein the crosslinked sublayer comprises: from about 5 to about 94.5 wt % of monomers carrying at least one charged moiety or precursor thereof; from about 5 to about 90 wt % of monomers carrying at least one polymerization initiation moiety or at least one polymer chain grafted therefrom; and from about 0.5 to about 5 wt % of a cross-linker.

3. The article of claim 1, wherein a molar ratio of charged moiety carrying monomers to the sum of monomers carrying at least one polymerization initiation moiety and the monomers carrying at least one polymer chain grafted therefrom, in the crosslinked sublayer, is from about 1:4 to about 4:1.

4. The article of claim 1, wherein the cross-linker comprises a bifunctional cross-linker.

5. The article of claim 1, wherein the crosslinked sublayer has a Mw in the range from about 5000 to about 400,000 Da.

6. The article of any claim 1, wherein the substrate surface has a surface charge density in the range from negative about 0.001 to about 0.2 C m.sup.2.

7. The article of claim 1, wherein the substrate surface has a surface potential in the range of negative about 20 to about 150 mV.

8. The article of claim 1, wherein the substrate surface is negatively charged, and the crosslinked sublayer comprises cationic moieties.

9. The article of claim 1, wherein the crosslinked sublayer comprises quaternary ammonium moieties.

10. The article of claim 1, wherein the polymer chains comprise fluorinated monomers, alkoxylated monomers, and/or mixtures thereof.

11. The article of claim 1, wherein the article is a consumer article, selected from the group consisting of shaving articles and hair removal devices.

12. The article of claim 1, wherein the article is packaging for consumer goods, a blow molded container.

13. A method of making an article comprising a substrate with an external polymer coating comprising polymer chains, the method comprising the steps of: a. providing a substrate comprising a charged surface; b. providing a crosslinked polymer comprising charged moieties having a charge opposite to that of said charged surface, and polymerization initiation moieties; c. applying said crosslinked polymer to said substrate surface; d. providing monomers reactive for polymerization with the polymerization initiation moieties; and e. polymerizing the monomers with the polymerization initiation moieties.

14. The method of claim 13, wherein the substrate in step a. comprises a negative surface charge and the charged moieties of the crosslinked polymer comprise quaternary ammonium moieties.

15. The method of claim 13, wherein step c. involves dip-coating the substrate surface in a solution, emulsion or dispersion of comprising the crosslinked polymer.

16. The method of claim 13, wherein polymerization step e. involves atom transfer radical polymerization.

17. The method of claim 13, wherein the monomers comprise fluorinated polymers.

18. An article obtainable by the method of claim 13.

19. An article comprising, a substrate having a charged surface; and a crosslinked polymer layer on said substrate surface, said crosslinked polymer comprising charged moieties having a charge opposite to that of said charged surface, and polymerization initiation moieties.

20. The article of claim 19, wherein the crosslinked polymer layer comprises: from about 5 to about 94.5 wt % of monomers carrying at least one charged moiety or precursor thereof from about 5 to about 90 wt % of monomers carrying at least one polymerization initiation moiety, and from about 0.5 to about 5 wt % of a cross-linker.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0188] Features and advantages of the invention will be appreciated upon reference to the following drawings, in which:

[0189] FIG. 1 is a view of a consumer article package.

[0190] FIG. 2 is a front view of a wet razor having a cartridge unit and a handle.

[0191] FIG. 2a is a rear view of the wet razor of FIG. 2.

[0192] FIG. 3 is a view of a blow molded consumer goods package.

[0193] FIG. 4 is a view of a consumer goods package comprising a closure.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0194] The following is a description of aspects and features of the invention, given by way of example only and with reference to the drawings.

EXAMPLES

[0195] The following examples demonstrate, by way of illustration only, application of a polymer layer to a charged substrate, in accordance with the invention.

[0196] Firstly, there is described the synthesis of a crosslinked polymer sublayer carrying charges moieties and polymerization initiation groups, in the form or cationic groups. Secondly there is described a dip-coating technique for a substrate with the crosslinked polymer sublayer, in the case of the example the substrate is silicon. Thirdly, grafting of polymer brushes from the coated substrate is carried out, in the example by ATRP polymerization.

[0197] Materials:

[0198] The following materials were used. Poly(ethylene glycol) methacrylate (PEGMA360, Average Mn 360), 2-chloro-propionyl chloride (97%), 1-dodecanethiol (DDT, 98%), ethylene glycol dimethacrylate (EGDMA, 98%), 2,2-azobis(2-methylpropionitrile) (AIBN, 98%), diethyl ether (99.8%) and tetrahydrofuran (THF, 99.9%), triethylamine (TEA, 99%), sodium hydrogen carbonate (>95%), magnesium sulphate (>95%), ethanol (99.5%), pressurised argon and nitrogen, ultrapure water (resistivity: 18.2 M cm, total organic content (TOC): 3-4 ppb), P-type, boron-doped, single side polished, 10 cm diameter and 500 m thick test-grade silicon wafers.

[0199] PEG-Cl was synthesized as follows. PEGMA360 (10.0 mL, 11.1 g, 30.8 mmol), 2-chloropropionyl chloride (3.0 mL, 3.9 g, 31.4 mmol) and tetrahydrofuran (40 mL) were placed into a round bottom flask cooled in an ice bath. TEA (4.2 mL, 3.1 g, 30.7 mmol) was added dropwise to the reaction mixture over a period of a half an hour and left to stir overnight. Diethyl ether (40 mL) was added subsequently before filtering the mixture in vacuo. The liquid filtrate was then washed three times with 2% sodium hydrogen carbonate solution, using a separating funnel. The resulting cloudy yellow liquid was then dried over anyhdrous magnesium sulphate and filtered in vacuo. The solution was then dried in vacuo, giving a yellow oil as a product (PEG-Cl, 8.7 g, 19.3 mmol, 62.5%).

[0200] PEG-N.sup.+ was synthesized as follows. PEGMA360 (10.0 mL, 11.0 g, 30.6 mmol), 2-chloropropionyl chloride (3.0 mL, 3.8 g, 29.9 mmol) and tetrahydrofuran (40 mL) were placed into a round bottom flask cooled in an ice bath. TEA (4.2 mL, 3.1 g, 30.7 mmol) was added dropwise to the reaction mixture over a period of a half an hour and left to stir overnight. Diethyl ether (40 mL) was added subsequently before filtering the mixture in vacuo. The liquid filtrate was then washed with 2% sodium hydrogen carbonate solution, three times, each time separating with a separating funnel. The resulting cloudy yellow liquid was then dried over anyhdrous magnesium sulphate and filtered in vacuo. The solution was then dried in vacuo, giving a yellow oil as a product (PEG-Cl, 8.0 g, 17.7 mmol, 58.0%).

[0201] A portion of that product (5.0 mL, 5.7 g, 12.7 mmol) was mixed with water (20 mL) in a round bottom flask in an ice bath. To this triethylamine (3.0 mL, 2.2 g, 22.0 mmol) was added dropwise over a period of 20 minutes. This was left to for 24 hours, after which the solution was dried in vacuo for 48 hours, leaving behind a yellow liquid product (PEG-N+, 5.9 g, 10.6 mmol, 83.7%).

[0202] Synthesis of Crosslinked Sublayer Polymers:

[0203] Three variants of the crosslinked sublayer polymer were prepared with weight ratios of 25/75 (A), 50/50 (B) and 75/25 (C) of PEG-Cl/PEG-N.sup.+, 5 parts of the cross-linker (EGDMA) and 5 parts of the chain transfer agent (DDT), according to the following reaction:

##STR00001##

[0204] Three round bottom flasks were prepared in a Radley 6-reaction carousel, each equipped with a stirrer bar and heated to 70 C.

[0205] Into flask 1 was placed ethanol (39 mL), DDT (60 L, 50 mg, 0.3 mmol), EGDMA (50 L, 53 mg, 0.3 mmol; as crosslinker), PEG-N+ (1800 L, 2068 mg, 3.8 mmol; as charge carrying monomer), PEG-Cl (494 L, 563 mg, 1.3 mmol; as polymer brush polymerization initiator carrying monomer) and AIBN (20 mg, 0.1 mmol) pre-dissolved in ethanol (1 mL).

[0206] Into flask 2 was placed ethanol (37 mL), DDT (60 L, 50 mg, 0.3 mmol), EGDMA (50 L, 53 mg, 0.3 mmol), PEG-N+(1200 L, 1380 mg, 2.5 mmol), PEG-Cl (988 L, 1126 mg, 2.5 mmol) and AIBN (20 mg, 0.1 mmol) pre-dissolved in ethanol (1 mL).

[0207] Into flask 3 was placed ethanol (39 mL), DDT (60 L, 50 mg, 0.3 mmol), EGDMA (50 L, 53 mg, 0.3 mmol), PEG-N+(600 L, 690 mg, 1.3 mmol), PEG-Cl (1422 L, 1621 mg, 3.6 mmol) and AIBN (20 mg, 0.1 mmol) pre-dissolved in ethanol (1 mL).

[0208] The reaction proceeded at 70 C. for 48 hours after which the products were separately precipitated in diethyl ether (15 mL), rinsed using ethanol and dried in vacuo. This produced three products, each of which were viscous yellow liquids.

[0209] Substrate Coating with Crosslinked Sublayer:

[0210] 11 cm substrates of silicon were cut from larger silicon wafers using a diamond cutter and placed into a 50:50 acetone:ethanol bath and sonicated for 15 minutes. After sonication, the silicon substrates were dried under a stream of nitrogen before being UV-Ozone treated (Jelight 42-200) for a further 15 minutes to remove hydrocarbon contamination and increase the total concentration of hydroxyl groups present on the surface.

[0211] Concomitantly 0.02 wt % solutions of each of the three crosslinked sublayer polymers A to C were prepared to which the silicon substrates were then added to incubate at room temperature for about 2 hours. Following incubation, the substrates were rinsed using water to remove excess crosslinked sublayer polymer solution, and dried under a stream of nitrogen.

[0212] Polymer layer thicknesses of 2 to 5 nm were observed. Polymers A and B were more readily soluble in water and yielded a more uniform coating on the surface than polymer C. Furthermore, the coating of polymer A remained more uniform than the coating of polymer B when subjected to soaking in water.

[0213] Grafting Polymer Brushes from Crosslinked Sublayer

[0214] Demonstrating the versatility of the crosslinked sublayer with charges and initiation groups, a range of polymers were grafted from model anionic substrates illustrating results for both strongly and weakly charged anionic substrates, i.e. mica and silicon respectively.

[0215] Polymer brush grafting was done with P(DMAEMA), P(MEO.sub.2MA), P(OEGMA300) and P(SBMA) polymers on the two anionic surfaces.

[0216] DMAEMA refers to 2-(dimethylamino)ethyl methacrylate.

##STR00002##

[0217] MEO.sub.2MA refers to the general structure for poly(ethylene glycol) methyl ether methacrylate:

##STR00003##

when n is equal to 2.

[0218] OEGMA.sub.300 refers to the same structure when a mixture of two monomers, where n is equal to either 4 or 5, are combined to produce an average molecular weight of 300.

[0219] P(SBMA) refers to 2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)-ammonium hydroxide.

##STR00004##

[0220] Materials:

[0221] 2,2-Bipyridyl (BiPy, 99%), Cu(I)Cl (99.995%), Cu(II)Cl2 (99.999%), (+)-sodium L-ascorbate (NaAsc, 98%), di(ethylene glycol) methyl ether methacrylate (MEO2MA, 95%), poly(ethylene glycol) methyl ether methacry-late (OEGMA300, Average Mn 300), 2-(dimethylamino)ethyl methacrylate (DMAEMA, 98%) and 2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)-ammonium hydroxide (SBMA, 97%), pressurised argon and nitrogen, ultrapure water (resistivity: 18.2 M cm, total organic content: 3-4 ppb), P-type, boron-doped, single side polished, 10 cm diameter and 500 m thick, <100> test-grade silicon wafers, natural muscovite mica, composition KAl.sub.2(Si.sub.3Al)O.sub.10(OH).sub.2, Al special grade.

[0222] Coating of Substrates:

[0223] 11 cm substrates of silicon were cut from larger silicon wafers using a diamond cutter and placed into a 50:50 acetone:ethanol bath and sonicated for 15 minutes. After sonication the silicon substrates were dried under nitrogen before being UV-Ozone treated (Jelight 42-200) for a further 15 minutes to remove hydrocarbon contamination and to increase the total concentration of hydroxyl groups present on the surface. Pieces of mica were cleaved on both sides to a thickness of around 50 m before being cut into 31 cm pieces using scissors, no further cleaning was undertaken.

[0224] Concomitantly a 0.02 wt % solution of the crosslinked sublayer polymer was prepared, into which mica and/or silicon substrates were placed and left for 2 hours to incubate at room temperature. Following incubation, the substrates were rinsed with water followed by soaking in an aqueous environment for 30 minutes before a final rinsing under water and then drying under nitrogen to ensure removal of any excess polymer.

[0225] Atomic-force microscopy (AFM) and X-ray reflectometry (XRR) results showed that the crosslinked sublayer, polymer mat adsorbed, as a thin layer, in the region of 1 nm thick, with X-ray photoelectron spectroscopy (XPS) indicating a high density of chlorine groups on the surface, in the region of 3.1 sites per square nanometer.

[0226] ATRP Polymerization on Coated Silicon:

[0227] Silicon substrates coated in accordance with the above was subjected to ATRP polymerization to graft polymer brushes therefrom. For each reaction, a total volume of 3 mL was used, to ensure coverage of the substrate, with a ratio between monomer, BiPy, Cu(I)Cl and Cu(II)Cl.sub.2 of 80:2.2:0.9:0.1. Of each 3 mL preparation, 1.5 mL constituted the monomer and the remaining 1.5 mL contained the ATRP reaction chemicals. MEO.sub.2MA, OEGMA300 and DMAEMA were liquids and thus were used neat. For SBMA a 50 vol/wt % solution was prepared.

[0228] The substrates were placed in flat bottomed containers which were sealed and purged with nitrogen. 3 mL aliquots of reaction mixtures of the monomers, BiPy, Cu(I)Cl and Cu(II)Cl.sub.2 as set forth in table 1 were injected into each of the purged containers and left to react for two hours (additionally 24 hours for MEO.sub.2MA), after which the reaction was quenched with oxygenated water before removing the substrates and rinsing them under water. The substrates were then placed in an aqueous environment for 30 minutes before a further rinsing and finally being dried under nitrogen.

TABLE-US-00001 TABLE 1 MEO.sub.2MA OEGMA.sub.300 DMAEMA SBMA Monomer (mmol) 8.13 5.25 8.91 2064 Monomer (mg) 1530 1580 1400 750 BiPy (mmol) 0.224 0.144 0.245 0.0738 BiPy (mg) 34.9 25.6 38.3 11.5 Cu.sup.(I)Cl (mmol) 0.0914 0.0591 0.100 0.0302 Cu.sup.(I)Cl (mg) 9.05 5.85 9.92 2.99 Cu.sup.(II)Cl.sub.2 (mmol) 0.0102 0.00656 0.0111 0.00336 Cu.sup.(II)Cl.sub.2 (mg) 1.36 0.882 1.50 0.451

[0229] ARGET ATRP on Silicon and Mica:

[0230] Silicon and mica substrates coated in accordance with the above was subjected to ATRP polymerization to graft polymer brushes therefrom. For each reaction, a total volume of 10 mL was used, with a ratio between monomer, BiPy, NaAsc and Cu(II)Cl.sub.2 of 1000:10:10:1. Of each 10 mL preparation, 5 mL constituted monomer and the remaining 5 mL contained the ATRP reaction chemicals. For each surface to be coated the quantities set forth in table 2 were used.

TABLE-US-00002 TABLE 2 DMAEMA SBMA Monomer (mmol) 29.7 8.95 Monomer (mg) 4670 2500 BiPy (mmol) 0.297 0.0895 BiPy (mg) 46.3 14.0 NaAsc (mmol) 0.297 0.0895 NaAsc (mg) 58.8 17.7 Cu.sup.(II)Cl.sub.2 (mmol) 0.0297 0.00895 Cu.sup.(II)Cl.sub.2 (mg) 3.99 1.20
The initiated mica or silicon substrates were placed in flat bottomed containers. 10 mL aliquots of the ATRP reaction mixture of monomer, BiPy, NaAsc and Cu(II)Cl.sub.2 were injected into each of the containers and left to react, after which the reaction was quenched with oxygenated water before removing the substrates and rinsing them under water. The substrates were then placed in an aqueous environment for 30 minutes before a further rinsing and finally being dried under nitrogen.

[0231] Examples of Articles

[0232] Referring now to FIG. 1 there is shown an article 2 in the form of packaging for a consumer article 4. The first and second frames 6 and 8, may be made of plastic providing the necessary structural integrity to support and display a consumer article, in this case a wet shave razor 4. However, other objects such as toothbrushes, lipstick, brushes, and other solid objects may be provided.

[0233] An outer container 10 is also provided. The outer container 10 holds frames 6 and 8. The outer container 10 may be made of plastic providing the necessary structural integrity to support and display the object 4. When the first and second frames 6 and 8 respectively, are inserted into outer container 100, the alignment of openings allow for viewing of the object 4.

[0234] In accordance with the present invention, any one or more of the surfaces of the packaging may be fully or partially coated with a polymer layer as discussed. Desirably the polymer brushes of the added polymer layer are composed to impart an increased coefficient of friction, especially under wet conditions.

[0235] Referring to FIG. 2, a consumer article in the form of a wet shave razor 4 generally includes a shaving or cartridge unit 12 attached to a handle 14 with the shaving unit 12 having one or more blades 16 (e.g. 5 blades shown) each with a sharpened edge and comprising stainless steel. The blades 16 are at least partially retained by blade clips 28. A cap 18 and guard 20 may also be included in the shaving unit 12, the cap 18 preferably including a lubricating strip or shaving aid composite affixed thereon. The shaving unit 12 also includes a frame or housing 22, preferably made of hard plastic. In this particular shaving unit 12, there is also present a lubricating ring 24 disposed around the periphery of the shaving unit. The cartridge unit 12 may be adapted for coupling and uncoupling from the razor handle 14 such that a new cartridge unit 12 may be coupled to the handle when the blades become dull or may be integral with a handle 14 so that the complete razor 4 is discarded when the blades become dull.

[0236] FIG. 2a depicts the opposite or rear side of the razor 4 showing the back side of the frame 22 and the cartridge unit 12.

[0237] In accordance with the present invention, any one or more of the surfaces of the wet shave razor 20 may be fully or partially coated with a polymer layer as discussed.

[0238] Preferably, for a modifying polymer layer added to portions of the handle 24, or the guard 25, the polymer brushes of the added polymer layer are composed to impart an increased coefficient of friction, especially under wet conditions.

[0239] Preferably, for a modifying polymer layer added to a razor blade or cartridge unit components to the rear or adjacent the blades (e.g. blade clips, frame, housing, cap, etc.) the polymer brushes of the added polymer layer are composed to impart a reduced coefficient of friction, especially under wet conditions.

[0240] While a specific embodiment of a razor is depicted in FIGS. 2 and 2a, any razor construction type is contemplated in the present invention.

[0241] Referring to FIG. 3, an article in the form of a blow molded consumer goods package 32 comprises a body 34 and a handle 36. The blow molded article 32 may additionally include a substrate, such as a film substrate, for decorative purposes, e.g., for labels, instructions, information, etc. A portion of the blow molded article, such as the body 34, the handle 36, and/or the substrate, may have low surface energy and/or hydrophobic properties such that water on the portion beads up when the blow molded article 32 is wet with water.

[0242] In accordance with the invention, a polymer layer is disposed on the handle 36 of the blow molded article 32. In order to counter beading of water on the handle, the polymer layer is composed to impart hydrophilic, polar, properties. This is believed to improve gripping in aqueous environments by minimizing water beads when the handle 36 is wet with water. Without intending to be bound by any theory, it is believed that preventing water (or other lubricious materials) from beading and improving wettability (e.g., promoting surfacing wetting) may each or both serve to thin the amount of water that a user must penetrate to engage the skin to the article's external surface.

[0243] The polymer layer can be included on or with any skin-engaging portion of the blow molded article 32 in addition to, or alternatively to the handle 36.

[0244] Referring to FIG. 4, a product container 42 comprises a body 44 defining a hollow interior and a closure 46. The closure 46 is coupled to the body 44 such that the closure covers, either directly or indirectly, the hollow interior. For example, the closure 46 can be coupled to the body 44 via a screw-type arrangement, snap-fit connection, friction-fit connection, lock-and-key connection, male-female engagement, etc.

[0245] In accordance with the invention a polymer layer is disposed on the closure 46. Similarly, to the example of FIG. 3, the polymer layer is composed to impart hydrophilic, polar, properties. This is believed to improve gripping in aqueous environments by minimizing water beads when the closure 46 is wet with water

[0246] The polymer layer can be included on any skin-engaging portion of the closure 30.

[0247] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value.

[0248] For example, a dimension disclosed as 40 mm is intended to mean about 40 mm.

[0249] Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

[0250] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.