Glass laminate structure

Abstract

A glass laminate structure is disclosed with a first and a second glass ply and a printed polymer ply interposed between the first and second glass plies, the printed polymer ply may be of PVB or PET having nanoparticle-containing ink adhered to at least a portion of a surface. Optionally there may be at least one further polymer ply which may be of PVB, PVA, COP or TPU. The nanoparticle-containing ink may contain electrically conductive nanoparticles, especially silver nanoparticle-containing ink. Also disclosed is a process for producing such a glass laminate structure.

Claims

1. A process for producing a glass laminate structure, the process comprising: a) providing a first glass ply and a second glass ply; b) providing a printed polymer ply having a nanoparticle-containing ink adhered to at least a portion of at least one surface thereof; c) interposing the printed polymer ply between the first and second glass plies; and d) after step c), heating the printed polymer ply to a temperature in the range of 90° C. to 160° C., thereby laminating the glass structure and firing/sintering the nanoparticle containing ink.

2. The process as claimed in claim 1, further comprising applying pressure in the range of 1 bar to 20 bar to the glass laminate structure during heating to the temperature in the range 90° C. to 160° C.

3. The process as claimed in claim 1, wherein providing a printed polymer ply comprises printing a polymer ply with the nanoparticle-containing ink.

4. A process as claimed in claim 3, wherein printing the polymer ply uses a printing method selected from roller coating, screen printing, gravure, flexography, lithography, pad printing, inkjet, and aerosol printing.

5. A process as claimed in claim 1, wherein the ink comprises nanoparticles and at least one solvent.

6. A process as claimed in claim 5, wherein the solvent is selected from a straight or branched chain C.sub.2 to C.sub.12 alcohol; a polyether; and water.

7. A process as claimed in claim 1, wherein the ink comprises between 10% and 80% by wt nanoparticles.

8. A process as claimed in claim 1, further comprising a step of depositing a conductive layer on the nano-particle containing ink before interposing the printed polymer ply between the first and second glass plies.

9. A process as claimed in claim 8, wherein depositing a conductive layer is by an electrodeposition or electroless-deposition process.

10. A process as claimed in claim 8, wherein the conductive layer comprises copper.

11. A process as claimed in claim 1, wherein the nanoparticle-containing ink has not undergone a separate sintering step.

12. The process as claimed in claim 1, wherein the nanoparticle-containing ink comprises electrically conductive nanoparticles.

13. The process as claimed in claim 1, wherein the nanoparticle-containing ink comprises an inorganic nanoparticle-containing ink.

14. The process as claimed in claim 1, wherein the printed portion of at least one surface of the printed polymer ply is electrically conductive.

15. The process as claimed in claim 1, wherein the printed portion of at least one surface of the printed polymer ply is electrically conductive and has a sheet resistance in the range 0.005 Ω/square to 200 Ω/square.

16. The process as claimed in claim 1, wherein the nanoparticles before heating have a dimension in the range 1 nm to 150 nm.

17. The process as claimed in claim 1, wherein the printed polymer ply comprises polyvinyl butyral (PVB), polyvinyl acetate (PVA), thermoplastic polyurethane (TPU) or polyethylene terephthalate (PET).

18. The process as claimed in claim 1, wherein the printed polymer ply is textured.

19. The process as claimed in claim 1, further comprising providing at least one further polymer ply, the further polymer ply comprising a polymer selected from polyvinyl butyral (PVB), polyvinyl acetate (PVA), polyethylene terephthalate (PET), cyclic olefin copolymer (COP) and thermoplastic polyurethane (TPU).

20. The process as claimed in claim 1, wherein the thickness of the printed polymer ply is in the range 20 μm to 2000 μm.

Description

(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 illustrates a schematic, not to scale, exploded view of a glass laminate structure according to a first embodiment of the present invention.

(3) FIG. 2 illustrates a schematic, not to scale, exploded view of a glass laminate structure according to a second embodiment of the present invention.

(4) FIG. 3 illustrates a schematic, not to scale, exploded view of a glass laminate structure according to a third embodiment of the present invention.

(5) FIG. 1 illustrates schematically and not to scale an exploded view of a glass laminate according to the invention. The laminate 2 comprises a first glass ply 4 and a second glass ply 6. Each glass ply is approximately 2.1 mm thick. Between the glass plies 4, 6 are a first PVB ply 8 (about 0.33 mm thick) and a second PVB ply 10 (about 0.38 mm thick). Interposed between the first and second PVB plies 8, 10 is a printed polymer ply 12 of PET (about 50 μm thick) having a printed surface 14 of silver nanoparticle ink (about 1.5 μm dry thickness).

(6) In FIGS. 2 and 3 the same reference numerals are used to indicate the same or similar features.

(7) FIG. 2 illustrates schematically and not to scale an exploded view of a second glass laminate according to the invention. The first and second glass plies 4, 6 and first and second PVB plies 8, 10 are present. However, in this embodiment, the printed polymer ply is the first PVB ply 8 (about 0.38 mm thick) having a printed surface 14 of silver nanoparticle ink (about 1.5 μm dry thickness).

(8) FIG. 3 illustrates schematically and not to scale an exploded view of a third glass laminate according to the invention. The same reference numerals are used to indicate the same or similar features. The first and second glass plies 4, 6 and first PVB ply 8 are present. However, in this embodiment, the second PVB ply is not present and the printed polymer ply is the first PVB ply 8 having a printed surface 14 of silver nanoparticle ink (about 1.5 μm dry thickness).

(9) In some embodiments, the printed surface of the polymer layer in the laminate may have a further conductive layer deposited on the nanoparticle ink.

(10) The invention is further illustrated, but not limited, by the following Examples.

EXAMPLES 1 TO 16

(11) PET-PVB duplet substrates (30 cm×30 cm; 50 μm thick PET and 330 μm thick PVB, the PVB and PET plies adhered together) were coated/printed with silver nano-particle containing flexographic silver ink using a K Bar coater (US3 Wire gauge, speed set at 3). The coating was applied to the surface of the PET ply.

(12) The coating area was approximately 10 cm×10 cm, with a dry coating thickness of approximately 1.5 μm (as measured by DekTak profilometer). The samples were then air dried.

(13) Bus bars of tinned copper were applied to the top and bottom boundaries of the coated area.

(14) A second PVB ply (thickness 380 μm) was applied to the PET side of the PET-PVB duplet.

(15) Two glass plies (2.1 mm thick) were placed on either side of the polymer plies.

(16) A pre-nip process was applied to the laminates by heating to 95° C. under reduced pressure in a vacuum bag to adhere and out-gas the polymer plies.

(17) The structures were then subjected to a lamination process by heating at 125° C. under 10 bar (1000 kPa) of pressure in an autoclave.

(18) The circuit resistance of the laminates as prepared, after pre-nip and after lamination was determined. The results for the circuit resistance measurements are indicated in Tables 1 to 3 below.

(19) Measurements were Taken at Three Locations:

(20) 1. both connectors connected to the top bus bar (“Top”);

(21) 2. both connectors connected to the bottom bus bar (“Bottom”); and

(22) 3. connectors connected diagonally between the top and bottom bus bars (“Diagonal”; X).

(23) Measurements were Taken:

(24) 1. after the prototype has been assembled (see Table 1),

(25) 2. after the pre nip cycle (see Table 2); and

(26) 3. after the autoclave cycle (see Table 3).

(27) The circuit resistance of control samples was also determined to show the change in resistance during the lamination cycle: control sample 1 containing a bus bar (I configuration), and control sample 2 containing 3 bus bars connected together (H configuration) and to show that the bus bars were not affecting the results.

(28) TABLE-US-00001 TABLE 1 Circuit resistance PET-PVB duplet after assembly Circuit Resistance (Ω) Example Top Bottom Diagonal  1 0.014 0.014 0.099  2 0.014 0.015 0.064  3 0.014 0.015 0.105  4 0.015 0.015 0.127  5 0.017 0.018 0.077  6 0.014 0.014 0.135  7 0.018 0.018 0.112  8 0.015 0.016 0.115  9 0.015 0.017 0.147 10 0.014 0.016 0.099 11 0.015 0.015 0.095 12 0.016 0.015 0.101 13 0.015 0.016 0.132 14 0.016 0.015 0.103 15 0.017 0.016 0.145 16 0.015 0.016 0.162 3 bus bars 0.014 0.015 0.024 1 bus bar 0.015

(29) TABLE-US-00002 TABLE 2 Circuit resistance PET-PVB duplet after pre nip. Circuit Resistance (Ω) Example Top Bottom Diagonal  1 0.015 0.015 0.050  2 0.015 0.015 0.037  3 0.014 0.015 0.154  4 0.015 0.015 0.062  5 0.015 0.015 0.040  6 0.014 0.014 0.058  7 0.015 0.014 0.057  8 0.015 0.015 0.060  9 0.015 0.014 0.065 10 0.015 0.014 0.051 11 0.015 0.014 0.047 12 0.014 0.014 0.047 13 0.014 0.014 0.064 14 0.016 0.015 0.052 15 0.015 0.016 0.066 16 0.015 0.014 0.080 3 bus bars 0.014 0.014 0.020 1 bus bar 0.015

(30) TABLE-US-00003 TABLE 3 Circuit resistance PET-PVB duplet after autoclave cycle Circuit Resistance (Ω) Example Top Bottom Diagonal 1 0.014 0.014 0.035 2 0.014 0.014 0.026 3 0.013 0.014 0.037 4 0.015 0.015 0.041 5 0.015 0.015 0.028 6 0.016 0.015 0.040 7 0.014 0.014 0.038 8 0.014 0.014 0.039 9 0.015 0.016 0.045 10 0.014 0.015 0.037 11 0.015 0.015 0.035 12 0.015 0.015 0.034 13 0.015 0.015 0.045 14 0.015 0.015 0.035 15 0.015 0.015 0.044 16 0.015 0.016 0.052 3 bus bars 0.014 0.015 0.024 1 bus bar 0.015

EXAMPLES 17 TO 20

(31) PVB polymer plies (30 cm×30 cm; 0.38 mm thick PVB) were coated/printed with silver nano-particle containing flexographic silver ink using a K Bar coater (US3 Wire gauge, speed set at 3).

(32) The coating area was approximately 10 cm×10 cm. After coating, the samples were air dried.

(33) Bus bars of tinned copper were applied to the top and bottom boundaries of the coated area.

(34) A second (non-printed) PVB ply (0.38 mm thick) was positioned on the printed side of the printed PVB ply. Two glass plies (2.1 mm thick) were placed on either side of the PVB.

(35) A pre-nip process was applied to the laminates by heating to 95° C. under reduced pressure in a vacuum bag for 1 hour to adhere and out-gas the polymer plies.

(36) The assemblies were then subjected to a lamination process by heating at 125° C. under 10 bar (1000 kPa) of pressure for 45 minutes in an autoclave. The sheet resistance of the laminates on assembly, after pre-nip and after lamination was determined using a Nagy SRM-12 (to measure non-contact sheet resistance). The results are indicated in Table 4.

(37) TABLE-US-00004 TABLE 4 On After After Assembly Prenip Autoclave Nagy Nagy Nagy Example (Ω/square) (Ω/square) (Ω/square) 17 12.71 0.201 180.2 18 13.41 0.239 163.2 19 13.07 0.201 173.7 20 12.71 0.286 176.3

EXAMPLES 21 TO 28

(38) These examples were made using nano-silver screen ink printed on (50 cm×50 cm) 175 μm thick PET (SU 330). The screen that was used was a 61/64 mesh giving a wet coating thickness of around 36 μm. Eight samples were produced. Once printed and air dried, four of the samples were plated in an electroplating bath to deposit around 10 μm copper layer above the printed area. The samples were laminated using PVB sheets (each 0.76 mm thick) and two glass plies (2.1 mm thick).

(39) The conductivity of the printed and plated samples was too low to measure using non-contact measurement so busbars were applied to provide an area 50 mm wide with a 45 mm separation. Pre-nip conditions were 45 mm cold de-air in a vacuum bag followed by 1 hr at 95° C. (still in the vacuum bag). The samples were autoclaved (1 hr, 125° C., 10 bar pressure).

(40) Resistance measurements are shown in Table 5, below, for the printed only samples (Examples 21 to 24) and the printed and plated samples (Examples 25 to 28). The measurements include the busbar resistance, and the contact resistance between the busbar and measurement area. However, by comparing measurements of the printed and printed and plated samples such contributions cannot account for the changes measured on the plated samples.

(41) TABLE-US-00005 TABLE 5 On After After Assembly Prenip Autoclave Example Printed and/or plated (Ω) (Ω) (Ω) 21 Printed only 0.082 0.053 0.047 22 Printed only 0.088 0.061 0.050 23 Printed only 0.085 0.060 0.049 24 Printed only 0.086 0.059 0.049 25 Printed and Plated 0.012 0.012 0.012 26 Printed and Plated 0.010 0.010 0.010 27 Printed and Plated 0.010 0.010 0.010 28 Printed and Plated 0.011 0.011 0.011