COATED SUBSTRATES AND METHODS FOR THE PREPARATION THEREOF

Abstract

The present application relates to methods of preparing a coated substrate and coated substrates which can be optionally prepared from such methods. The methods comprise depositing on the substrate a single abrasion resistant layer by magnetron sputtering or depositing on the substrate a dual layer comprising a first abrasion resistant layer deposited by magnetron sputtering and a second abrasion resistant layer deposited by plasma-enhanced chemical vapor deposition.

Claims

1. A method for preparing a coated substrate, the method comprising: depositing on the substrate, a single abrasion resistant layer by reactive magnetron sputtering; or a dual layer including a first abrasion resistant layer deposited by reactive magnetron sputtering and a second abrasion resistant layer deposited by plasma-enhanced chemical vapor deposition (PECVD).

2. The method of claim 1, wherein, for the dual layer, the method comprises: depositing the first abrasion resistant layer on the substrate; and depositing the second abrasion resistant layer on the first abrasion resistant layer.

3. The method of claim 1, wherein the reactive magnetron sputtering comprises sputtering under a double magnetron cathode configuration in which two cathode bodies are inclined from the normal about 10-60o to face each other.

4. The method of claim 1, wherein the reactive magnetron sputtering is a “Closed Field” bipolar pulsed TwinMag sputtering configuration.

5. The method of claim 1, wherein, the single abrasion resistant layer or the first abrasion resistant layer of the dual layer comprises AlSiN.

6. The method of claim 1, wherein the second abrasion resistant layer in the dual layer comprises SiOxCy.

7. The method of claim 1, wherein the dual layer is deposited on the substrate and the first abrasion resistant layer comprises AlSiN or AlSiON and the second abrasion resistant layer comprises SiOxCy.

8. The method of claim 1, wherein prior to deposition, the substrate is treated with a radio frequency (RF) plasma.

9. The method of claim 8, wherein the RF plasma is an Ar/CO2 or Ar/N2 plasma having a power that is sufficiently high enough to remove surface contamination and not induce polymer oxidation and/or decrease the transparency less than 10% or less than 5%.

10. The method of claim 1, wherein the substrate comprises a material selected from: a transparent thermoplastic, poly(methyl methacrylate) or polycarbonates.

11. (canceled)

12. The method of claim 1, wherein the substrate is an automotive glazing component selected from a moon roof, a window, a windshield and a tailgate.

13. (canceled)

14. The method of claim 1, wherein for the dual layer the reactive magnetron sputtering and the PECVD are performed sequentially in the same chamber.

15. (canceled)

16. A coated substrate, comprising: a substrate; and a coating deposited on the substrate, the coating comprising, a single abrasion resistant layer, or a dual layer comprising, in either order, a first abrasion resistant layer comprising AlSiN or AlSiON and a second abrasion resistant layer comprising SiOxCy.

17. The coated substrate of claim 16, wherein for the dual layer the first abrasion resistant layer is deposited on the substrate and the second abrasion resistant layer is deposited on the first abrasion resistant layer.

18. The coated substrate of claim 16, wherein prior to deposition, the substrate has been treated with a radio frequency (RF) plasma.

19. The coated substrate of claim 18, wherein the RF plasma is an Ar/CO.sub.2 or Ar/N.sub.2 plasma having a power that is sufficiently high enough to remove surface contamination and not induce polymer oxidation and/or decrease the transparency less than 10% or less than 5% T.

20. The coated substrate of claim 16, wherein the substrate comprises a material selected from: a transparent thermoplastic, poly(methyl methacrylate) or polycarbonates.

21. The coated substrate of claim 16, wherein the substrate comprises poly(methyl methacrylate) polycarbonates.

22. The coated substrate of claim 16, wherein the substrate is an automotive glazing component selected from a moon roof, a window, a windshield or a tailgate.

23. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present application will now be described in greater detail with reference to the drawings in which:

[0023] FIG. 1 shows exemplary transmission spectra of poly(methyl methacrylate) (PMMA) treated with 30 W O.sub.2 plasma ({circle around (1)}), 80 W O.sub.2 plasma ({circle around (3)}), 30 W CO.sub.2 plasma ({circle around (4)}) and 80 W CO.sub.2 plasma ({circle around (5)}) in comparison to untreated PMMA ({circle around (2)}).

[0024] FIG. 2 shows exemplary transmission spectra of a AlSiN (or AlSiON) coating deposited by reactive magnetron sputtering (MS) on PMMA (*) in comparison to uncoated, untreated PMMA (**).

[0025] FIG. 3 is an exemplary scanning electron microscope (SEM) image of a SiO.sub.xC.sub.y coating deposited by PECVD on PMMA showing the locations of the energy-dispersive X-ray (EDX) spectra taken in Table 1. Scale bar at bottom of image indicates 10 μm.

[0026] FIG. 4 shows exemplary Dektak 3 Surface Profile measurement taken after Pin-on-disc wear tests using a steel ball at 100 mN force with 80 rpm rotation speed for 25 min wear time for a MS AlSiN coating deposited on PMMA substrate in comparison to uncoated, untreated PMMA.

[0027] FIG. 5 shows exemplary transmission spectra of a SiO.sub.xC.sub.y coating deposited by plasma-enhanced chemical vapor deposition (PECVD) on PMMA (*) in comparison to uncoated, untreated PMMA (**).

[0028] FIG. 6 is an exemplary SEM image of a SiO.sub.xC.sub.y coating deposited by PECVD on PMMA showing the locations of the EDX spectra taken in Table 2. Scale bar at bottom of image indicates 60 μm.

[0029] FIG. 7 shows exemplary transmission spectra of a SiO.sub.xC.sub.y coating deposited by PECVD on CO.sub.2 plasma-(*) or O.sub.2 plasma-(***) cleaned PMMA in comparison to uncoated, untreated PMMA (**).

[0030] FIG. 8 shows exemplary Dektak 3 Surface Profile measurement taken after Pin-on-disc wear tests using a steel ball at 100 mN force with 80 rpm rotation speed for 25 min wear time for a PECVD SiOxCy coating deposited on PMMA substrate in comparison to uncoated, untreated PMMA.

[0031] FIG. 9 shows exemplary transmission spectra of a PECVD SiOxCy coating, MS AlSiN coating, PECVD SiOxCy/MS AlSiN coatings and MS AlSiN/SiOxCy coating deposited on PMMA substrate in comparison to uncoated, untreated PMMA.

[0032] FIG. 10 shows exemplary Dektak 3 Surface Profile measurement taken after Pin-on-disc wear tests using a steel ball at 100 mN force with 80 rpm rotation speed for 25 min wear time for a PECVD SiOxCy/MS AlSiN coating deposited on PMMA substrate in comparison to uncoated, untreated PMMA.

[0033] FIG. 11 shows exemplary Dektak 3 Surface Profile measurement taken after Pin-on-disc wear tests using a steel ball at 100 mN force with 80 rpm rotation speed for 25 min wear time for a MS AlSiN/PECVD SiOxCy coating deposited on PMMA substrate in comparison to uncoated, untreated PMMA.

DETAILED DESCRIPTION

I. Definitions

[0034] Unless otherwise indicated, the definitions and embodiments described in this and other sections are intended to be applicable to all embodiments and aspects of the present application herein described for which they are suitable as would be understood by a person skilled in the art.

[0035] In understanding the scope of the present application, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. The term “consisting” and its derivatives, as used herein, are intended to be closed terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The term “consisting essentially of”, as used herein, is intended to specify the presence of the stated features, elements, components, groups, integers, and/or steps as well as those that do not materially affect the basic and novel characteristic(s) of features, elements, components, groups, integers, and/or steps.

[0036] Terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies.

[0037] The term “and/or” as used herein means that the listed items are present, or used, individually or in combination. In effect, this term means that “at least one of” or “one or more” of the listed items is used or present.

[0038] As used in this application, the singular forms “a”, “an” and “the” include plural references unless the content clearly dictates otherwise.

[0039] The term “suitable” as used herein means that the selection of specific reagents or conditions will depend on the reaction being performed and the desired results, but none-the-less, can generally be made by a person skilled in the art once all relevant information is known.

[0040] The term “abrasion resistant layer” refers to the ability of a coating layer to withstand abrasion and means that the layer possess the ability to pass a test for abrasion resistance according to Military Specifications MIL-C-675C.

[0041] The term “blocking layer” as used herein in reference to an “ultraviolet blocking layer” means that the layer at least partially blocks radiation having wavelengths in the ultraviolet region. Similarly, the term “blocking layer” as used herein in reference to an “infrared blocking layer” means that the layer at least partially blocks radiation having wavelengths in the infrared region.

[0042] The term “transparent” as used herein in reference to a transparent thermoplastic means that the thermoplastic has a percent transmittance of at least 80% in a wavelength range of from about 380 nm to about 700 nm.

II. Methods

[0043] A vacuum-based coating method using either reactive magnetron sputtering under a “Closed Field” bipolar pulsed TwinMag configuration or a combination of reactive magnetron sputtering under a TwinMag configuration and plasma enhanced chemical vapor deposition was used to generate a scratch, abrasion and wear protective single layer AlSiN (or AlSiON) or dual layer AlSiN (or AlSiON)/SiO.sub.xC.sub.y coating on poly(methyl methacrylate) (PMMA).

[0044] The reactive magnetron and PECVD process can advantageously be performed sequentially in the same chamber which may, for example, have lower capital investment and/or operation costs associated with it than a method comprising wet coating prior to CVD. The performance of the sputtering conditions was assessed and PMMA coated with the single layer AlSiN (or AlSiON) or the dual layer AlSiN/SiO.sub.xC.sub.y was assessed for surface morphology, optical transmittance, adhesion, and wear resistance.

[0045] Accordingly, the present application includes a method for preparing a coated substrate, the method comprising, depositing on the substrate, by reactive magnetron sputtering, a single abrasion resistant layer, or a dual layer in which a first abrasion resistant layer of the dual layer is deposited by magnetron sputtering.

[0046] In an embodiment, the method comprises: depositing on the substrate, by reactive magnetron sputtering, a single abrasion resistant.

[0047] In an embodiment, the method comprises: depositing on the substrate, in either order: [0048] by reactive magnetron sputtering, the first abrasion resistant layer; and [0049] by plasma-enhanced chemical vapor deposition (PECVD), a second abrasion resistant layer.

[0050] In an embodiment, the method comprises depositing a single abrasion resistant layer on the substrate.

[0051] In an embodiment, the method comprises [0052] depositing the first abrasion resistant layer on the substrate; and [0053] depositing the second abrasion resistant layer on the first abrasion resistant layer.

[0054] In an embodiment, the reactive magnetron sputtering is carried out in a TwinMag configuration. In another embodiment, the reactive magnetron sputtering comprises sputtering under a double magnetron cathode configuration in which two cathode bodies are inclined from the normal about 10-60° to face each other. In a further embodiment, the reactive magnetron sputtering under a “Closed Field” bipolar pulsed TwinMag sputtering configuration.

[0055] In an embodiment, the single layer or the first abrasion resistant layer in the dual layer comprises, consists essentially of or consists of a silicon-metal composite. In another embodiment, the single layer or the first abrasion resistant layer in the dual layer comprises a silicon-metal composite. In a further embodiment, the single layer or the first abrasion resistant layer in the dual layer consists essentially of a silicon-metal composite. In another embodiment, the single layer or the first abrasion resistant layer in the dual layer consists of a silicon-metal composite. In an embodiment, the metal in the silicon-metal composite is aluminum. In another embodiment, the silicon-metal composite is AlSiN (or AlSiON); for example, the single layer or the first abrasion resistant layer in the dual layer comprises, consists essentially of or consists of the AlSiN (or AlSiON).

[0056] In an embodiment, the second abrasion resistant layer in the dual layer comprises, consists essentially of or consists of SiO.sub.xC.sub.y. In another embodiment, the second abrasion resistant layer in the dual layer comprises SiO.sub.xC.sub.y. In a further embodiment, the second abrasion resistant layer in the dual layer consists essentially of SiO.sub.xC.sub.y. In another embodiment of the present application, the second abrasion resistant layer in the dual layer consists of SiO.sub.xC.sub.y.

[0057] In an embodiment, the first abrasion resistant layer in the dual layer consists essentially of or consists of AlSiN (or AlSiON) and the second abrasion resistant layer in the dual layer consists essentially of or consists of SiO.sub.xC.sub.y. In another embodiment of the present application, the first abrasion resistant layer in the dual layer consists essentially of AlSiN and the second abrasion resistant layer in the dual layer consists essentially of SiO.sub.xC.sub.y. In a further embodiment, in the dual layer the first abrasion resistant layer consists of AlSiN and the second abrasion resistant layer consists of SiO.sub.xC.sub.y.

[0058] In an embodiment, prior to deposition, the substrate is treated with a radio frequency (RF) plasma. The treatment with the RF plasma can comprise any suitable conditions. For example, in the examples of the present application it was found that treatment of transparent thermoplastic PMMA with high energy (80 W) plasma in a Diener plasma surface cleaning system type FEMTO resulted in the yellowing of the samples and treatment of PMMA with Ar/O.sub.2 plasma was found to result in oxidation of the PMMA which may reduce coating adhesion. Therefore if the substrate comprises, for example, PMMA or a similar material, the person skilled in the art desirably selects a lower power plasma that will not oxidize the PMMA. Accordingly, in another embodiment, the RF plasma is an Ar/CO.sub.2 or Ar/N.sub.2 plasma has a power that is sufficiently high enough to remove surface contamination and not induce polymer oxidation and/or decrease the transparency less than 10% or less than 5%, such as but not limited to a power of from about 10 W to about 100 W, about 25 W to about 35 W or about 30 W. It should be noted that the power suitable depends on, for example but not limited to, the type of plasma cleaner used and the size of polymer substrate.

[0059] The substrate is any suitable substrate. In an embodiment, the substrate comprises, consists essentially of or consists of a plastic or a glass. In an embodiment, the substrate comprises, consists essentially of or consists of a transparent thermoplastic. In another embodiment, the substrate comprises a transparent thermoplastic. In a further embodiment, the substrate consists essentially of a transparent thermoplastic. In another embodiment of the present application, the substrate consists of a transparent thermoplastic. In an embodiment, the transparent thermoplastic is selected from a polycarbonate, a poly(methyl methacrylate) or the like. In another embodiment, the transparent thermoplastic is poly(methyl methacrylate); for example, the substrate comprises, consists essentially of or consists of the poly(methyl methacrylate).

[0060] In an embodiment, the substrate is an automotive glazing component. In another embodiment, the automotive glazing component is selected from a moon roof, a window, a windshield and a tailgate.

[0061] In an embodiment, the reactive magnetron sputtering and the PECVD are performed sequentially in the same chamber.

[0062] In an embodiment, the method further comprises depositing one or more additional coating layers. For example, in an embodiment, the method further comprises depositing one or more ultraviolet (UV) and/or infrared (IR) blocking layers. In an embodiment, the UV blocking layer comprises, consists essentially of or consists of ZnO, TiO.sub.2 or combinations thereof. In another embodiment, the IR blocking layer comprises, consists essentially of or consists of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), silver or combinations thereof. In an embodiment, the UV and/or IR blocking layers are deposited on the substrate prior to the deposition of the abrasion resistant layers. In another embodiment, the UV and/or IR blocking layers are deposited by a method comprising reactive magnetron sputtering, PECVD or combinations thereof.

[0063] In an embodiment, the method further comprises depositing a superhydrophobic layer on the abrasion resistant layers.

[0064] In an alternative embodiment, the method does not comprise the deposition of additional coating layers.

[0065] The present application also includes a coated substrate prepared according to a method for preparing a coated substrate of the present application.

III. Coated Substrates

[0066] A scratch, abrasion and wear protective single layer AlSiN (or AlSiON) or a dual layer AlSiN (or AlSiON)/SiO.sub.xC.sub.y coating on poly(methyl methacrylate) (PMMA) was obtained from a vacuum-based coating method that used a combination of reactive magnetron sputtering under a TwinMag configuration and plasma enhanced chemical vapor deposition. PMMA coated with the single layer AlSiN (or AiSiON) or the dual layer AlSiN (or AlSiON)/SiO.sub.xC.sub.y was assessed for surface morphology, optical transmittance, adhesion, and wear resistance.

[0067] Accordingly, the present application includes a coated substrate, comprising: [0068] a substrate; and [0069] a coating deposited on the substrate, the coating comprising, a single layer AlSiN (or AiSiON) or a dual layer, in either order, a first abrasion resistant layer consisting essentially of or consisting of AlSiN (or AlSiON) and a second abrasion resistant layer consisting essentially of or consisting of SiO.sub.xC.sub.y.

[0070] In some embodiments, the coated substrate is prepared according to a method for preparing a coated substrate of the present application.

[0071] In an embodiment of the present application, the first abrasion resistant layer in the dual layer is deposited on the substrate and the second abrasion resistant layer in the dual layer is deposited on the first abrasion resistant layer.

[0072] In an embodiment, the first abrasion resistant layer in the dual layer consists essentially of the AlSiN (or AlSiON) and the second abrasion resistant layer consists essentially of the SiO.sub.xC.sub.y. In another embodiment, the first abrasion resistant layer in the dual layer consists of the AlSiN (or AlSiON) and the second abrasion resistant layer consists of the SiO.sub.xC.sub.y.

[0073] In an embodiment, prior to deposition, the substrate has been treated with a radio frequency (RF) plasma. The treatment with the RF plasma can comprise any suitable conditions. Accordingly, in another embodiment, the RF plasma is an Ar/CO.sub.2 or Ar/N.sub.2 plasma having a power of from about 10 W to about 100 W for a piece of 25 cm.sup.2 plastic substrate in a Diener plasma surface cleaning system type FEMTO, about 25 W to about 35 W or about 30 W.

[0074] The substrate is any suitable substrate. In an embodiment, the substrate comprises, consists essentially of or consists of a plastic or a glass. In an embodiment, the substrate comprises, consists essentially of or consists of a transparent thermoplastic. In another embodiment, the substrate comprises a transparent thermoplastic. In a further embodiment, the substrate consists essentially of a transparent thermoplastic. In another embodiment of the present application, the substrate consists of a transparent thermoplastic. In an embodiment, the transparent thermoplastic is selected from a polycarbonate, a poly(methyl methacrylate) or the like. In another embodiment, the transparent thermoplastic is poly(methyl methacrylate); for example, the substrate comprises, consists essentially of or consists of the poly(methyl methacrylate).

[0075] In an embodiment, the substrate is an automotive glazing component. In another embodiment, the automotive glazing component is selected from a moon roof, a window, a windshield and a tailgate.

[0076] In an embodiment, the coating further comprises one or more additional coating layers. For example, in an embodiment, the coated substrate further comprises one or more ultraviolet (UV) and/or infrared (IR) blocking layers. In an embodiment, the UV blocking layer comprises, consists essentially of or consists of ZnO, TiO.sub.2 or combinations thereof. In another embodiment, the IR blocking layer comprises, consists essentially of or consists of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), silver or combinations thereof. In an embodiment, the UV and/or IR blocking layers are between the substrate and the abrasion resistant layers. In another embodiment, the coated substrate further comprises a superhydrophobic layer deposited on the abrasion resistant layers.

[0077] In an alternative embodiment, the coating does not comprise additional coating layers; i.e. it is devoid of additional coating layers.

[0078] The following non-limiting examples are illustrative of the present application:

EXAMPLES

Example 1: Surface Pre-Treatment of PMMA with CO.SUB.2., N.SUB.2 .and O.SUB.2 .Plasma

[0079] For substrate surface cleaning and with an object of coating adhesion improvement, various radio frequency (RF) plasma conditions were investigated for use to treat PMMA samples.

[0080] PMMA samples were treated with O.sub.2/Ar and CO.sub.2/Ar plasma at 30 and 80 W for 20 minutes in a Diener plasma surface cleaning system type FEMTO. The samples treated with 80 W plasma were observed to have a yellow appearance. A transmission spectrum (FIG. 1) showed significant differences between the PMMA samples treated with 80 W plasma and the untreated PMMA/PMMA samples treated with only 30 W plasma.

Example 2: AlSiN (or AlSiON) on PMMA

[0081] Reactive magnetron sputtering under “Closed Field” bipolar pulsed TwinMag configuration was used to deposit AlSiN (or AlSiON) coatings on PMMA samples using a Si and an Al metallic targets under Ar/N.sub.2 reactive gas. Before the deposition, pre-treatment of the PMMA thermoplastic by gas plasma in vacuum with low partial pressure was used in order to clean the substrate and improve the adhesion between the PMMA substrate and the coating material.

[0082] Single layers of AlSiN (or AlSiON) by sputtering were deposited on the PMMA substrate as described below.

I. Deposition Process—Magnetron Sputtering of AlSiN on PMMA Substrates

[0083] The deposition equipment used in the examples described herein can be described as home-made sputtering with two different magnetron guns with opposite magnetic poles purchased from Kurt J. Lesker Company in a con-focal geometry. In this configuration, the magnetron sputter guns, which can host targets of two-inch in diameter, were 45° tilted and located 10 cm off-axis of the substrate. The AlSiN thin films were deposited at room temperature onto 10×10 cm.sup.2 PMMA substrates by reactive magnetron sputtering from a 99.99% purity Al and Si target using a AE PE II 5 KW power supply that provided a 90 W and 40 kHz resonant switch-mode power dual (floating) outputs to each sputtering gun. Before each deposition process, the PMMA substrate to be used was washed with liquid soap and then deionized water. The PMMA substrate was then rinsed first with abundant deionized water and subsequently dried with nitrogen gas and placed on the holder-plate inside the sputtering chamber. An Ar/N.sub.2 gas mixture was then introduced into the vacuum chamber to reach around 30 mtorr pressure. An AC voltage of 140V at 35 KHz from a Solvix® pulsed-DC power supply was applied on the substrate holder to generate a plasma to clean the PMMA substrate for around 2 hours.

[0084] The distance from the center of the target to the center of the substrate was around 5-7 cm, and a substrate rotation of 900 counts/sec was used to achieve a good homogeneity during the material deposition. The base pressure achieved before deposition was always between 2×10.sup.−7 Torr and 4.0×10.sup.−7 Torr, which were measured with an ionization vacuum gauge. The working gas was 99.99% argon and nitrogen. The DC power values of 80 W were used; these values correspond, when divided by the target area (20.27 cm.sup.2), to the power densities of 3.94 W/cm.sup.2. The deposition pressure values were around 7.0 mTorr; these pressure values were manually adjusted while maintaining argon and nitrogen flow constant with a value of 104 sccm and 100 sccm, respectively.

[0085] The thickness of an exemplary AlSiN (or AlSiON) coating was determined by a Bruker Dektak™ profilometer to be 230 nm. A FilmTek™ 3000 photospectrometer was used to measure the thin film transmittance in comparison to uncoated PMMA (FIG. 2).

[0086] Table 1 and FIG. 3 are energy-dispersive X-ray (EDX) spectroscopy data and the SEM image clearly showing an AlSiN (AlSiON) film was deposited on the PMMA. Please noted that N element cannot be detected by the EDX method. C element originated from the oxy-carbon surface species generated after the coatings were exposed to ambient air.

TABLE-US-00001 TABLE 1 EDX spectroscopy data showing an AlSiN (AlSiON) film deposited on the PMMA C O Al Si Spectrum # (atomic %) (atomic %) (atomic %) (atomic %) Spectrum 1 20.44 36.52 18.78 24.26 Spectrum 2 23.33 34.42 18.29 23.97 Spectrum 3 25.23 34.94 17.14 22.69 Spectrum 4 23.82 35.05 17.56 23.57 Spectrum 5 24.89 35.12 17.15 22.83 Spectrum 6 56.49 21.34 9.63 12.54 Mean 28.42 32.88 16.63 22.06 Std. deviation 11.73 4.86 2.98 4.00 Max. 56.49 36.52 18.78 25.12 Min. 20.44 21.34 9.63 12.54

[0087] Adhesion was tested according to Military Specifications MIL-C-675C. Briefly, a ½″ wide strip of cellophane tape was pressed against the coated surface and quickly removed. The AlSiN (or AlSiON) coated PMMA sample passed the test; no delamination was observed. Abrasion resistance was also tested according to Military Specifications MIL-C-675C: In particular, for moderate abrasion, the coated sample was rubbed with a cheese cloth pad for 25 cycles (50 strokes) and for severe abrasion, a MIL-E-12397 compliant eraser was rubbed over the coated surface for 20 complete cycles (40 strokes). The AlSiN (or AlSiON) coated PMMA sample passed the test; no delamination was observed.

[0088] FIG. 4 shows exemplary Dektak 3 Surface Profile measurement taken after Pin-on-disc wear tests using a steel ball at 100 mN force with 80 rpm rotation speed for 25 min wear time for a MS AlSiN (or AlSiON) coating deposited on PMMA substrate in comparison to uncoated, untreated PMMA.

[0089] In summary, reactive magnetron sputtering with “Closed Field” bipolar pulsed TwinMag configuration was able to deposit transparent AlSiN (or AlSiON) films on PMMA substrates which had useful adhesive and abrasion resistance properties.

Example 3: SiO.SUB.x.C.SUB.y .Coatings on PMMA

[0090] Plasma-enhanced chemical vapor deposition (PECVD) was used to deposit SiO.sub.xC.sub.y coatings on PMMA samples using a hexamethyldisiloxane (HMDS) precursor. Before the deposition, pre-treatment of the PMMA thermoplastic by gas plasma in vacuum with low partial pressure was used in order to clean the substrate and improve the adhesion between the PMMA substrate and the coating material.

[0091] Single layers of SiO.sub.xC.sub.y (by PECVD) were deposited on the PMMA substrate as described below.

II. Deposition Process—PECVD Coating of SiO.sub.xC.sub.y on PMMA Substrates

[0092] The deposition unit used for depositing SiO.sub.xC.sub.y thin films on PMMA substrates was built by Plasmionique Inc. and was modified to produce PECVD coatings by using liquid precursors. The carbon-based coating was a composite structure comprised of the elements C, H, Si and O. The precursor used was a carbon-containing and silicon-containing liquid precursor such as hexamethyldisiloxane. Hexamethyldisilazane can replace hexamethyldisiloxane as liquid precursor. Hexamethyldisilazane contains N instead of O along with the other the elements C, H, and Si. When hexamethyldisilazane is used as precursor, a deposit of SiN.sub.xC.sub.y thin films is obtained which has similar protective properties as SiO.sub.xC.sub.y thin films. If needed, the oxygen can be added as a gas during deposition process. Other precursors (hydrocarbon, silane, organosilane, organosilazane, etc.), or mixtures containing similar chemical elements, may also be used but were not tested in these experiments. The thin-film material was obtained by ion-assisted plasma deposition using radio frequency decomposition of liquid precursors. The deposition was conducted at room temperature on 10×10 cm.sup.2 PMMA substrates. Radio-frequency plasma was generated in a capacitive mode, on the substrate holder, by using an RF power supply with a frequency of 13.6 MHz. Before each deposition process, the PMMA substrate was washed with liquid soap, rinsed with abundant water, dried using a compressed air gun and then placed on the substrate holder inside the deposition chamber. The vacuum system was started and Ar gas with a flow of 20 sccm was introduced into the vacuum chamber to reach a pressure of 20 mTorr. RF plasma was generated on the substrate, with a power of 20 W, for 20 minutes, for cleaning the PMMA substrate. After plasma cleaning, without stopping the RF plasma, the thin film growth was initiated by introducing the liquid precursor with a flow rate of 5 g/h. After introducing the liquid precursor, the deposition pressure increased to 25 mTorr. After deposition (30-60 minutes), the plasma, the liquid precursor, and the Ar flow was stopped and the chamber was vented to atmospheric pressure. The substrate was removed from the chamber being ready for testing. The thickness of the thin film obtained after a deposition process of 60 minutes was around 10 microns.

[0093] The thickness of an exemplary SiO.sub.xC.sub.y coating was determined by a Bruker Dektak™ profilometer to be 2.2 μm. A FilmTek™ 3000 photospectrometer was used to measure the thin film transmittance in comparison to uncoated PMMA (FIG. 5).

[0094] Table 2 and FIG. 6 are energy-dispersive X-ray (EDX) spectroscopy data and the SEM image clearly showing a SiO.sub.xC.sub.y film was deposited on the PMMA.

TABLE-US-00002 TABLE 2 EDX spectroscopy data showing a SiO.sub.xC.sub.y film deposited on PMMA Spectrum No. C (atomic %) O (atomic %) Si (atomic %) 1 50.17 23.33 26.50 2 55.67 21.99 22.34 3 55.55 21.25 23.19 4 57.46 21.07 21.47 Mean 54.71 21.91 23.38 Std. deviation 3.15 1.03 2.20 Max. 57.46 23.33 26.50 Min. 50.17 21.07 21.47

[0095] Adhesion was tested according to Military Specifications MIL-C-675C. Briefly, a ½″ wide strip of cellophane tape was pressed against the coated surface and quickly removed. The SiO.sub.xC.sub.y coated PMMA sample passed the test; no delamination was observed. Abrasion resistance was also tested according to Military Specifications MIL-C-675C: In particular, for moderate abrasion, the coated sample was rubbed with a cheese cloth pad for 25 cycles (50 strokes) and for severe abrasion, a MIL-E-12397 compliant eraser was rubbed over the coated surface for 20 complete cycles (40 strokes). The SiO.sub.xC.sub.y coated PMMA sample passed the test; no delamination was observed. SiO.sub.xC.sub.y was coated on PMMA (film thickness 2.1 μm) which was pre-cleaned with CO.sub.2 plasma versus O.sub.2 plasma. A transmission spectrum of these coated samples in comparison to uncoated, untreated PMMA is shown in FIG. 7. The SiO.sub.xC.sub.y film on CO.sub.2 plasma pre-cleaned PMMA passed the adhesion test and film cracking was not observed. In contrast, the SiO.sub.xC.sub.y film on O.sub.2 plasma pre-cleaned PMMA did pass the adhesion test but the film had cracking/particles. While not wishing to be limited by theory, the O.sub.2 plasma surface pre-treatment oxidizes PMMA and thereby reduces the coating adhesion.

[0096] FIG. 8 shows exemplary Dektak 3 Surface Profile measurement taken after Pin-on-disc wear tests using a steel ball at 100 mN force with 80 rpm rotation speed for 25 min wear time for a PECVD SiOxCy coating deposited on PMMA substrate in comparison to uncoated, untreated PMMA.

[0097] In summary, PECVD with a RF bottom configuration was able to deposit transparent SiO.sub.xC.sub.y films on N.sub.2 or CO.sub.2 plasma treated PMMA substrates which had useful adhesive and abrasion resistance properties.

Example 4: Deposition of Dual Layer AlSiN (or AlSiON)/SiOxCy or SiOxCy/AlSiN (or AlSiON) Protective Coatings on PMMA

[0098] Reactive magnetron sputtering under a double magnetron cathode (TwinMag) configuration in which two cathode bodies inclined from the normal (10-30°) to face each other (TwinMag) and plasma enhanced chemical vapor deposition (PECVD) were used to deposit dual layer protective coatings on poly(methyl methacrylate) (PMMA). Before the deposition, pre-treatment of the PMMA thermoplastic by gas plasma in vacuum with low partial pressure was used in order to clean the substrate and improve the adhesion between the PMMA substrate and the coating material.

[0099] A dual layer of AlSiN (or AlSiON)/SiOxCy (by combined sputtering/PECVD) was deposited on the PMMA substrate. The methods for the deposition of the layer of AlSiN (or AlSiON) by sputtering and the layer of SiOxCy by PECVD were described above in example 2 and 3.

[0100] FIG. 9 shows exemplary transmission spectra of a PECVD SiOxCy coating, MS AlSiN (or AlSiON) coating, PECVD SiOxCy/MS AlSiN (or AlSiON) coatings and MS AlSiN (or AlSiON)/PECVD SiOxCy coating deposited on PMMA substrate in comparison to uncoated, untreated PMMA.

[0101] FIG. 10 shows exemplary Dektak 3 Surface Profile measurement taken after Pin-on-disc wear tests using a steel ball at 100 mN force with 80 rpm rotation speed for 25 min wear time for a PECVD SiOxCy/MS AlSiN (or AlSiON) coating deposited on PMMA substrate in comparison to uncoated, untreated PMMA.

[0102] FIG. 11 shows exemplary Dektak 3 Surface Profile measurement taken after Pin-on-disc wear tests using a steel ball at 100 mN force with 80 rpm rotation speed for 25 min wear time for a MS AlSiN (or AlSiON)/PECVD SiOxCy coating deposited on PMMA substrate in comparison to uncoated, untreated PMMA.

RESULTS AND DISCUSSION

[0103] The performance of the sputtering, PECVD and combined sputtering/PECVD coated PMMA thermoplastics were assessed for their surface morphologies, optical transmittance, adhesion, and wear resistance and they all showed significant improvement in wear, scratch and abrasion resistance compared to bare PMMA and maintained high transparency to visible light (>85%). With this coating method, other functionalities can also be added to the plastic such as a UV- or IR-blocking layer and/or a hydrophobic layer.

[0104] Such coatings may, for example, be useful in the development of lightweight automotive polymer glazings that may reduce weight by up to about 50% compared to current glass glazings as the coated thermoplastics such as PMMA may have potential to replace tempered glass or laminated glass.

[0105] While the present application has been described with reference to what are presently considered to be the preferred examples, it is to be understood that the application is not limited to the disclosed examples. To the contrary, the present application is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0106] All publications, patents and patent applications are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety. Where a term in the present application is found to be defined differently in a document incorporated herein by reference, the definition provided herein is to serve as the definition for the term.