Splash screen

Abstract

A splash screen, and a process for making a splash screen, comprising a glass sheet, the glass sheet comprising, a substrate of soda lime silica glass having a coating deposited on at least at least a first surface, the coating comprising a corrosion-protection layer deposited directly on the first surface of the substrate, the corrosion-protection layer having a thickness in the range 24 nm to 125 nm and comprising pyrolytically deposited silica with intentional doping of 7 atom % or lower. The splash screen provides reduced moisture induced corrosion of the glass surface.

Claims

1. A splash screen comprising a glass sheet, the glass sheet comprising: a substrate of soda lime silica glass having a coating deposited on at least a first surface, the coating comprising a corrosion-protection layer deposited directly on the first surface of the substrate, the corrosion-protection layer having a thickness in the range 24 nm to 125 nm and comprising pyrolytically deposited silica with intentional doping of 7 atom % or lower, further comprising a second corrosion-protection layer deposited on the second surface of the substrate, the second corrosion-protection layer comprising silica deposited from a liquid coating composition comprising a polysilazane; and wherein the splash screen is a bath screen and/or a shower screen and wherein the glass substrate with corrosion-protection layer passes standard EN1096.

2. The splash screen as claimed in claim 1, wherein the pyrolytically deposited silica has intentional doping of 5 atom % or lower.

3. The splash screen as claimed in claim 1, wherein the pyrolytically deposited silica has intentional doping of 3 atom % or lower.

4. The splash screen as claimed in claim 1, wherein the corrosion-protection layer comprises 93 mol % to 100 mol % silicon dioxide.

5. The splash screen as claimed in claim 1, wherein the corrosion-protection layer has a thickness in the range 30 nm to 120 nm.

6. The splash screen as claimed in claim 1, wherein the corrosion-protection layer has a thickness in the range 50 nm to 110 nm.

7. The splash screen as claimed in claim 1, wherein the outer layer of the coating comprises pyrolytically deposited silica with intentional doping of 7 atom % or lower.

8. The splash screen as claimed in claim 1, wherein the outer layer of the coating comprises the corrosion-protection layer.

9. The splash screen as claimed in claim 1, wherein the corrosion-protection layer is the only layer of the coating on the first surface.

10. The splash screen as claimed in claim 1, further comprising a further layer deposited on the corrosion-protection layer, the further layer comprising silica deposited from a liquid coating composition comprising a polysilazane.

11. The splash screen as claimed in claim 1, wherein the substrate is adapted to hold fixings to fix the splash screen in position for use.

12. The splash screen as claimed in claim 11, wherein the substrate is adapted to hold fixings by having at least one hole drilled through the substrate.

13. The splash screen as claimed in claim 1, wherein the substrate is toughened.

14. The splash screen as claimed in claim 1, further comprising fixings to fix the splash screen in position for use, and wherein the fixings comprise adhesive portions or mechanical attachment portions to attach the fixings to the splash screen.

15. A process for manufacturing a splash screen comprising a glass sheet, the process comprising: providing a substrate of soda lime silica glass, pyrolytically depositing a corrosion-protection layer directly on a first surface of the substrate, the corrosion-protection layer comprising silica with intentional doping of 7 atom % or lower and being deposited to a thickness in the range 24 nm to 125 nm, further providing a liquid coating composition comprising a polysilazane, contacting the second surface of the substrate with the coating composition, and curing the coating composition at a predetermined curing temperature thereby forming a further layer comprising silica on the second surface, and wherein the splash screen is a bath screen and/or a shower screen and wherein the glass substrate with corrosion-protection layer passes standard EN1096.

16. The process as claimed in claim 15, wherein pyrolytically depositing the corrosion-protection layer comprises contacting the surface of the substrate with a precursor mixture comprising a source of silicon, a source of oxygen and, optionally, a radical scavenger.

17. The process as claimed in claim 15, wherein the source of silicon comprises a silane.

18. The process as claimed in claim 15, wherein the radical scavenger comprises an alkene and wherein pyrolytically depositing the corrosion-protection layer is conducted when the substrate is at a temperature in the range 550 C. to 750 C.

19. The process as claimed in claim 15, wherein pyrolytically depositing the corrosion-protection layer is by online chemical vapour deposition conducted during the float glass production process.

20. The process as claimed in claim 15, wherein the liquid coating composition comprises a solvent and wherein the polysilazane is a compound of formula [R.sup.1R.sup.2SiNR.sup.3].sub.n, wherein one of R.sup.1, R.sup.2, and R.sup.3 are each independently selected from H or C.sub.1 to C.sub.4 alkyl, and n is an integer.

21. The process as claimed in claim 15, wherein the polysilazane comprises perhydropolysilazane.

22. The process as claimed in claim 15, wherein contacting the second surface with the coating composition comprises a method selected from dip coating, spin coating, roller coating, spray coating, air atomisation spraying, ultrasonic spraying, and/or slot-die coating.

23. The process as claimed in claim 22, further comprising cleaning the first and/or second surface before contacting the surface with the coating composition, and wherein cleaning the second surface comprises one or more of: abrasion with ceria, washing with alkaline aqueous solution, deionised water rinse and/or plasma treatment.

24. The process as claimed in claim 15, wherein the predetermined curing temperature is a temperature of 130 C., and wherein curing the coating composition on the surface of the substrate comprises irradiating with ultraviolet (UV) radiation.

25. The process as claimed in claim 15, wherein the polysilazane is at a concentration in the range 0.5% to 80% by weight in the coating composition.

26. The process as claimed in claim 15, wherein the further silica layer is deposited to a thickness of 15 nm or higher.

27. The process as claimed in claim 15, wherein the further layer of silica layer has a refractive index in the range 1.42 to 1.55.

28. The process for manufacturing a splash screen, the process comprising, providing a soda lime silica glass substrate having a first and second surface, and a coating deposited on at least a first surface, the coating comprising a corrosion-protection layer deposited directly on the first surface of the substrate, the corrosion-protection layer having a thickness in the range 24 nm to 125 nm and comprising pyrolytically deposited silica with intentional doping of 7 atom % or lower, providing a liquid coating composition comprising a polysilazane, contacting the second surface of the substrate with the coating composition, and curing the coating composition at a predetermined curing temperature, thereby forming a further layer comprising silica on the second surface, wherein the splash screen is a bath screen and/or a shower screen and wherein the glass substrate with corrosion-protection layer passes standard EN1096.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

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

(2) FIG. 1 is a graph showing X-Ray Photo-Electron Spectroscopy (XPS) depth profile results for Example 1.

(3) FIG. 2 illustrates schematically a splash screen according to an embodiment of the present invention.

(4) FIG. 3a is a scanning electron micrograph of Example 1 at 80 sample tilt and 50,000 magnification.

(5) FIG. 3b is a scanning electron micrograph of Example 1 at 90 sample tilt and 50,000 magnification.

DETAILED DESCRIPTION OF THE INVENTION

(6) FIG. 1 shows the results of XPS of Example 1. The curves are as follows: 2, O1s scan A; 4, O1s total; 6, Si2p; 8, O1s scan B; 10, Na1s; 12, Ca2p3/2; 14, Mg1s; and 16, C1s.

(7) FIG. 2 illustrates schematically a splash screen 18 comprising a soda lime silica glass substrate 20 having a coating 22 on a surface. The coating comprises a single layer. The single layer is a corrosion-protection layer 24 deposited directly on the substrate surface. The corrosion protection layer is of silica 69 nm thick (as determined by SEM) with no intentional doping.

(8) The invention is further illustrated, but not limited, by the following examples.

Examples

Preparation of Example and Comparative Examples

(9) Example 1 is a 10 mm thick glass sheet having (on the air side surface) a pyrolytic coating of silica deposited by online chemical vapour deposition. The coating was deposited on a ribbon of the soda lime silica glass during the float glass production process. The conditions for deposition were as follows: a gaseous precursor mixture (in nitrogen carrier gas) of silane, oxygen gas and ethylene (as radical scavenger) in a ratio of 1:6:4 respectively (flow rates of 6 standard litres per minute (slm) silane, 36 slm oxygen, 24 slm ethylene) was directed on to the surface of a glass ribbon across its whole coated width of about 3.2 m using a single coater. The temperature of the glass ribbon at the region of coating was approximately 1251-1254 F. (677 C. to 679 C.). The line speed was 229 inch/minute (5.8 m/min). The coating was determined to be of a thickness of approximately 69 nm by scanning electron microscopy (see below).

(10) Example 2 was a float glass sample having on a surface a pyrolytic silica coating of thickness 35 nm deposited generally as indicated for Example 1.

(11) Example 3 was a float glass sample having on a surface a pyrolytic silica coating of thickness 25 nm deposited generally as indicated for Example 1.

(12) XPS Results

(13) X-ray photoelectron spectroscopy (XPS) was used to provide depth profile analysis of Example 1. XPS spectra were carried out through the coating to identify the elements present. An argon ion etch beam was operated at 1 keV (M) producing a beam current of 1.68 A. A 15 second etch time per level was used. The results are shown in FIG. 1. The depth profiles from Example 1 confirmed the presence of a silica layer on the glass surface. Sodium was only detected in the bottom half of the silica layer.

(14) Scanning Electron Microscopy

(15) Example 1 was imaged using scanning electron microscopy (SEM). Images of the specimens were captured at an instrument magnification of 50,000 using both 80 (FIG. 3a) and 90 (FIG. 3b) specimen tilt. Specimens were taken from the sample, mounted on to aluminium stubs in cross section and ultrasonically cleaned in methanol for 10 seconds. The cleaned specimens were coated with a thin layer of platinum (providing a uniform conductive surface) prior to examination using the SEM.

(16) The 80 tilt images of the specimen from Example 1 (FIG. 3a) showed an amorphous coating layer with a smooth surface; there were a few small particles at the surface.

(17) Measurements taken from the 90 tilt images of Example 1 (FIG. 3b) showed that the silica layer was approximately 69 nm thick.

(18) Optical Measurements

(19) The a* and b* colours and reflection of Example 1 were determined. The results are as indicated in Table 1 together with comparative results for the substrate: float glass. The coating of the Example has little effect on the colour of the sample, but there is a slight reduction in reflection. This is an advantageous property of embodiments of splash screens according to the present invention.

(20) Friction Test

(21) A friction test was conducted on samples to provide an indication as to how easily a surface could be wiped clean. The friction test was conducted on cleaned samples (Benteler washing machine) of the Examples and on float glass (as a comparative) and involved placing a felt covered weight of 320 g on the sample and slowly increasing the angle of inclination of the sample until the weight starts to slide down the sample. The angle of inclination was recorded and is indicated in Table 2, below.

(22) Durability and Artificial Weathering

(23) The following durability and artificial weathering tests were conducted to evaluate Example 1 and the Comparative (uncoated float glass). The test were as follows: condensation, salt spray, Taber test area fraction remaining (%), Taberdays of humidity before weathering, NaOH (1M) durability before weathering, post NaOH testdays of humidity before weathering, HCl (1M) durability, post HCl testdays of humidity before weathering, post acid cleaner dipdays of humidity before weathering, post alkali cleaner dipdays of humidity before weathering, humidity only (days) before weathering, and cleaning test. The condensation, salt spray and humidity tests were used in order to indicate the resistance of a coating to humidity in order to try and replicate the environment of a bathroom. The standard test time for EN1096 testing is 21 days (504 hours). This test was run for 1000 hours to get a further understanding of the durability of the coatings.

(24) The chemical durability tests involved submerging the test sample into 1 M NaOH solution held at 70 C. for 25 minutes. A further test involved samples being submerged in a common household cleaner at room temperature for 64 hours to assess if there was any coating damage.

(25) The results of the environmental (weathering), chemical and humidity testing are as indicated in Tables 3, 4 and 5.

(26) TABLE-US-00001 TABLE 1 Sample FS Color a* FS Color b* FS Reflect (%) Comparative (Float Glass) 1.35 0.61 7.81 Example 1 1.38 0.18 7.57

(27) TABLE-US-00002 TABLE 2 Friction Value Friction Value (Angle of (Angle of glass) glass) Coating Coated (air) Uncoated (tin) Sample thickness (nm) side side Comparative Uncoated 34 (uncoated) 28 (10 mm thick float glass) Example 1 69 39 28 Example 2 35 49 36 Example 3 25 51 30

(28) TABLE-US-00003 TABLE 3 Environmental Tests Taber Test Taber - Days Condensation Salt Spray Area Fraction of humidity (according to (according to Remaining before Sample EN 1096) EN 1096) (%) weathering Comparative Fail Pass 97.63 8 (Float Glass) Example 1 Pass Pass 98.56 56 Example 2 Pass Pass N/A N/A Example 3 Pass Pass N/A N/A

(29) TABLE-US-00004 TABLE 4 Chemical Tests NaOH (1M) Post NaOH Post HCl Durability Test - days of Test - days of before humidity before HCl (1M) humidity before Sample weathering weathering Durability weathering Comparative Pass 9 Pass 24 (Float Glass) Example 1 Pass 109 Pass 109

(30) TABLE-US-00005 TABLE 5 Cleaning and Humidity Tests Post Acid Post Alkali Cleaner dip - Cleaner dip - Humidity days of humidity days of humidity only (days) before before before Cleaning Sample weathering weathering weathering Test Comparative 8 8 6 Pass (Float Glass) Example 1 120+ 120+ 76+ Pass