TRANSPARENT UNIT

Abstract

Improvements in or relating to transparent units (such as glazing units, which may also be referred to as insulating glass units) and their methods of manufacture are disclosed. Each transparent unit comprises first and second panes of transparent material each having an outwardly facing side and an inwardly facing side. Each inwardly facing side is at least partially coated with a reactive interlayer made by the application of a reactive interlayer coating composition. The inwardly facing side of the first and second panes of transparent material are spaced apart partially or totally by a transparent spacer made of a pre-cured condensation curable material or a substantially pre-cured condensation curable material adhered to the inwardly facing side of the first and second panes of transparent material by way of the reactive interlayers. In various embodiments, the pre-cured condensation curable material is a silicone based material.

Claims

1. A transparent unit comprising first and second panes of transparent material each having an outwardly facing side and an inwardly facing side, each inwardly facing side is at least partially coated with a reactive interlayer and the inwardly facing side of the first and second panes of transparent material are spaced apart partially or totally by a transparent spacer made of a pre-cured condensation curable material or a substantially pre-cured condensation curable material adhered to the inwardly facing side of the first and second panes of transparent material by way of the reactive interlayers.

2. The transparent unit in accordance with claim 1, wherein the transparent unit is a glazing unit and the first and second panes of transparent material are glass.

3. The transparent unit in accordance with claim 1, wherein the pre-cured condensation curable material spacer material is a substantially pre-cured condensation curable silicone based material or fully pre-cured condensation silicone based material obtained by curing a condensation curable silicone composition comprising: (i) at least one condensation curable silyl terminated polymer having at least one, optionally at least 2, hydrolysable and/or hydroxyl functional group(s) per molecule; (ii) a cross-linker selected from the group consisting of silanes having at least 2 hydrolysable groups, optionally at least 3, hydrolysable groups per molecule group; and/or silyl functional molecules having at least 2 silyl groups, with each silyl group containing at least one hydrolysable group; and (iii) a condensation catalyst selected from the group consisting of titanates and zirconates; wherein: the molar ratio of hydroxyl groups to hydrolysable groups is between 0.1:1 to 4:1; the titanates and zirconates comprise M-OR functions where M is titanium or zirconium and R is an aliphatic hydrocarbon group; and the molar ratio of M-OR functions to the hydroxyl groups is from 0.01:1 and 0.6:1.

4. The transparent unit in accordance with claim 3, wherein the condensation curable silicone composition is stored in a 2 part manner prior to cure having polymer (i) and cross-linker (ii) in one part and polymer (i) and catalyst (iii) in the other part, or having cross-linker (ii) in one part and polymer (i) and catalyst (iii) in the other part, or polymer (i) and optionally cross-linker (ii) in one part and cross-linker (ii) and catalyst (iii) in the other part.

5. The transparent unit in accordance with claim 1, wherein the substantially pre-cured condensation curable silicone based material or fully pre-cured condensation curable silicone based material is a substantially cured or fully cured elastomer or a substantially cured or fully cured gel which is tacky to the touch given the presence of reactive polymer chains for physical adhesion to occur when the substantially cured or fully cured silicone based material is brought into contact with a substrate surface.

6. The transparent unit in accordance with claim 3, wherein the reactive interlayer is prepared by the application of a reactive interlayer coating composition onto a substrate surface, which reactive interlayer coating composition is a coating composition or a layer of an uncured sealant composition which can chemically interact with both the substrate surface and/or the silicone based material surface.

7. The transparent unit in accordance with claim 6, wherein the reactive interlayer coating composition is a coating composition comprising a composition containing a titanate or zirconate ingredient and/or a tin (II) and/or tin (IV) based ingredient and may additionally contain silanes having groups which will chemically interact with excess silanol groups in the silicone based material.

8. The transparent unit in accordance with claim 6, wherein the reactive interlayer coating composition is a coating composition comprising: from 0.01 to 90% by weight of a titanate, zirconate, tin (II) or tin (IV) catalyst; from 0 to 90% by weight of one or more silanes having at least two hydrolysable groups and optionally one or more alternative functional groups for creating chemical bonds with substrate surfaces; and from 5 to 90% by weight of a silicone solvent or an organic solvent; with the total weight % of the coating composition being 100 weight %.

9. The transparent unit in accordance with claim 8, wherein the reactive interlayer coating composition is a coating composition comprising: from 1 to 50% by weight of a titanate, zirconate, tin (II) or tin (IV) catalyst; from 1 to 50% by weight of one or more silanes having at least two hydrolysable groups and optionally one or more alternative functional groups for creating chemical bonds with substrate surfaces; and from 5 to 90% by weight of a silicone solvent or an organic solvent; with the total weight % of the coating composition being 100 weight %.

10. The transparent unit in accordance with claim 8, wherein the functional groups are selected from amines, thiol, epoxy, alkoxy, acetoxy, or oximino, to enhance adhesion on various substrates.

11. A method of making the transparent unit in accordance with claim 1, said method comprising: (i) applying a coating of reactive interlayer coating composition on the inwardly facing side of each of the first and second transparent panes and allowing them to dry/cure for a predefined time period; (ii) applying the transparent spacer onto the inwardly facing side of the first transparent pane which has been pre-treated with the reactive interlayer coating composition; and (iii) positioning the region of the inwardly facing side of the second transparent pane which has been pre-treated with a reactive interlayer onto the transparent spacer and leaving the transparent spacer to adhere to the respective inwardly facing side of the transparent panes via the reactive interlayer; (iv) optionally, filling a cavity around a periphery of the transparent panes with a secondary sealant, and if present curing the secondary sealant to bond with the two transparent panes.

12. The method in accordance with claim 11, wherein the transparent unit is an insulated glazing unit.

13. The method in accordance with claim 11, wherein the secondary sealant is present and is a transparent moisture-curable hot melt silicone adhesive composition.

14. The method in accordance with claim 11, wherein the reactive interlayer is chemically reactable with the substrate surface and/or the surface of the silicone based material.

15. The method in accordance with claim 11, wherein the reactive interlayer coating composition is applied in a wet and/or uncured state onto a cleaned surface of a substrate and then a facing surface of a silicone based material is brought into contact with the substrate surface by the application of pressure such that the reactive interlayer is sandwiched between the silicone based material surface and the substrate surface and chemical adhesion develops.

16. The method in accordance with claim 11, wherein the reactive interlayer coating composition is a coating composition comprising: from 0.01 to 90% by weight of a titanate, zirconate, tin (II) or tin (IV) catalyst; from 0 to 90% by weight of one or more silanes having at least two hydrolysable groups and optionally one or more alternative functional groups for creating chemical bonds with substrate surfaces; and from 5 to 90% by weight of a silicone solvent or an organic solvent; with the total weight % of the coating composition being 100 weight %.

17. The method in accordance with claim 16, wherein the reactive interlayer coating composition is a condensation curable sealant composition comprising: at least one condensation curable silyl terminated polymer having at least one, optionally at least 2, hydrolysable and/or hydroxyl functional group(s) per molecule (ai); a cross-linker (aii); and a condensation catalyst (aiii).

18. The method in accordance with claim 11, wherein the reactive interlayer coating composition is allowed to dry and/or cure on the substrate surface onto which it was first applied and then subsequently the silicone based material surface is brought into contact with the substrate surface and pressure is applied to sandwich the reactive interlayer between an elastomer or a gel surface and the substrate surface and initial physical adhesion is observed but after a time period of 1 to 2 days or more chemical bonding develops.

19. The transparent unit in accordance with claim 1, wherein the transparent spacer edge is protected by a metal, a glass or a plastic profile, optionally wherein a gas barrier sealant is added to reduce gas and moisture permeation inside or outside the unit.

20. (canceled)

21. The transparent unit in accordance with claim 1, wherein a desiccant is in contact with gas present in an internal cavity of the unit to reduce moisture ingress.

Description

EXAM1PLES

[0121] The compositions used for examples were as follows with viscosity values at 25 C. measured by using a Brookfield cone plate viscometer (RV DIII) using a cone plate. Compositions were applied at 23 C. and 50% relative humidity.

TABLE-US-00001 TABLE 1 Base Composition Part E Comparative example Tin A B C D (IV) OH terminated 97.4 polydimethylsiloxane (viscosity ca 50,000 mPa .Math. s) OH terminated 91.6 99.1 96.75 polydimethylsiloxane (viscosity ca 13,500 mPa .Math. s) Trimethoxysilyl terminated 8.4 100 polydimethylsiloxane (viscosity ca 56,000 mPa .Math. s) Nanocyl NC 7000 1.6 0.9 carbon nanotubes 1,6 bis (trimethoxysilyl) 1.0 3.25 hexane

TABLE-US-00002 TABLE 2 Catalyst Composition Part E Comparative example Tin A B C D (IV) OH terminated 49.39 polydimethylsiloxane (viscosity ca 50,000 mPa .Math. s) OH terminated 49.39 99.42 polydimethylsiloxane (viscosity ca 13,500 mPa .Math. s) OH terminated 94.9 polydimethylsiloxane (viscosity ca 4,000 mPa .Math. s) Trimethoxysilyl terminated 99.26 99.7 polydimethylsiloxane (viscosity ca 56,000 mPa .Math. s) Nanocyl NC 7000 1.01 carbon nanotubes Cabosil LM150 4.7 fumed silica tetra n-butyl titanate 0.22 0.74 0.3 Dimethyltin neodecanoate 0.58

[0122] The mixing ratio of the base part to the catalyst part was 1:1 for formulation A, 10 to 1 for formulation B, 1.75 to 1 for formulation C,1 to 1 for formulation D and 1:1 for formulation E.

Examples

Example 1

Formulation A

[0123] A float glass substrate was treated with DOW CORNING 1200 OS PRIMER CLEAR a commercial Primer from Dow Corning Corporation of Michigan, USA, which has been used according to the manufacturer's instructions and used as reactive interlayer coating composition.

[0124] Strips of pre-cured formulation A material (approx. 1 cm width, 5-6 cm in length and 2 mm thick were attached to above described substrate at different times after the application of the DOW CORNING 1200 OS PRIMER CLEAR.

[0125] The adhesion of the strips to the float glass substrate was examined after approximately one hour and Table 3 summarizes the results. [0126] Y means that a strip was well adhered to the glass plates and that attempts to remove it resulted in a cohesive failure within the strip. [0127] N means that the strip was easily removable (peeled off)-adhesive failure) from the glass substrate.

TABLE-US-00003 TABLE 3 Time upon treatment with DOW CORNING 1200 OS PRIMER CLEAR Result <1 min Y 5 Y 10 Y 20 N/Y 30 N COMPARATIVE Example 1 (no reactive Does not stick and removed interlayer on substrate) adhesively

[0128] Example 2. Cured materials were prepared from compositions A, B and C as depicted in Tables 1 and 2. Strips of approx. 12 cm length by 2 cm width and 2 mm thickness were adhered to glass plates. Half of the surface of these plates was pre-treated with DOW CORNING 1200 OS PRIMER CLEAR, which serves as reactive interlayer. The DOW CORNING 1200 OS PRIMER CLEAR was used according to the manufacturer's instructions. The strips were brought into contact with the glass substrate within 2 minutes of the application of DOW CORNING 1200 OS PRIMER CLEAR thereon.

[0129] Upon inspection it was noticed that the strips peel adhesively from the part which has not been coated with DOW CORNING 1200 OS PRIMER CLEAR (i.e. adhered by physical adhesion). In contrast, it was impossible to detach the strips from the part treated with the reactive interlayer without breaking the strip itself (i.e. adhered by chemical adhesion).

Example 3

[0130] Elastomer/gel materials of formulation D as well as a Sn-cure elastomer formulation E (comparative example) were cured in moulds to form circular 1-cm thick articles. These articles were adhered to stainless steel plates (substrates). Half the surface of these plates was pre-treated with DOW CORNING 1200 OS PRIMER CLEAR, which served as a reactive interlayer. The articles were attached to the steel plates within 2 minutes of the application of DOW CORNING 1200 OS PRIMER CLEAR in the same manner as depicted in FIG. 8. Results are summarized in table 4.

TABLE-US-00004 TABLE 4 E Sn IV based elastomer Cured material (comparative example) D Adhesion to Adhesive failure, does Adhesive failure, does not untreated substrate not stick stick surface (no reactive interlayer) Adhesion to Adhesive failure, does Adhesion, cohesive failure substrate treated not stick with reactive interlayer

Example 4

[0131] The experiment described in example 3 was repeated using an aluminium substrate. The cured material used was a 5 cm by 1 cm cured strip of composition C as depicted in Tables 1 and 2 above. Upon inspection it was determined that the strip did not adhere to the part of the aluminium substrate surface which had not been pre-treated with the reactive interlayer and as such due to physical nature of the adhesion these were easily detached (peeled off). In contrast, it was impossible to detach the strip from the part of the aluminium substrate surface pre-treated with the reactive interlayer coating composition (DOW CORNING 1200 OS PRIMER CLEAR). The strip itself broke cohesively due to the chemical nature of adhesion to the substrate surface.

Example 5

[0132] The surface of a stainless steel plate (approx. 1015 cm) was divided in three areas. The three areas were treated as follows: [0133] (1) no treatment [0134] (2) DOW CORNING 1200 OS PRIMER CLEAR (3) primer DOW CORNING OS 3 in 1 primer/cleaner.

[0135] The two primers were used to prepare reactive interlayers and were applied according to the manufacturer's instructions.

[0136] A strip of pre-cured composition B, as depicted in Tables 1 and 2, which was the same size as the steel plate and a thickness of about 2 mm was cut and carefully placed on the plate. After approximately 70 hours attempts were made to remove the elastomer strip from the plate. Only physical adhesion (clean peel) was observed on the part of the plate not treated with primer. The other two parts of the plate were strongly bound (chemically) to formulation B and a clean detachment was impossible. The strongest adhesion was observed for the part of the surface primed with DOW CORNING 1200 OS PRIMER CLEAR.

Example 6

[0137] Cured materials were prepared by mixing the two components of the composition together in a Base: curing agent weight ratio of 1:1. The base component was: [0138] a 2,000 mPa.Math.s (at 25 C.) silanol terminated polydimethylsiloxane. The curing agent components were: [0139] 100 weight parts of a 2,000 mPa.Math.s trimethoxysilyl terminated polydimethylsiloxane (at 25 C.) and [0140] 0.2 weight parts of tetra-n-butyl titanate.

[0141] The material was mixed in a speedmixer 4 times 30 seconds at a speed of 2300 rpm. The material was poured into a 2 meter long PVC U-shaped profile with internal dimension 185 mm.sup.2 and was allowed to cure for 7 days. The resulting cured material was applied on glass panes which had been primed several minutes earlier using Dow Corning 1200 OS primer. An example of this is provided as FIG. 1 which depicts two panes of glass separated by a continuous ribbon of the cured material adhered to the periphery of the of each glass panes effectively functioning as spacer between the two panes of glass.

[0142] The upper surface of the lower glass pane depicted and the lower surface of the upper glass pane were coated around their peripheries with Dow Corning 1200 OS primer which was allowed to dry for approximately 30 minutes.

[0143] A pre-measured ribbon of cured material as hereinbefore described was applied to the periphery of the upper surface of the lower glass pane and subsequently the lower surface of the upper pane of glass was adhered to the cured material in the regions previously primed. Almost immediately after construction the glass unit depicted in FIG. 1 could be moved and handled without impairing the structure of the construction because of the strength of the bonds formed as described herein.

Example 7

[0144] H-shaped samples of the pre-cured silicone, based on the composition in example 6, were moulded in a 2 meter long PVC U-shaped profile with internal dimension 185 mm.sup.2 and allowed to cure at room temperature for 7 days. 50 mm long sample pieces of this moulded product were prepared (approximate dimensions: 50185 mm.sup.3). Glass pieces having 50704 mm.sup.3 were primed on one surface with Dow Corning 1200 OS primer and left for about 30 minutes. The samples of the pre cured silicone were then applied on the primed glass leading to tensile H-pieces units.

[0145] H-piece samples were also applied to the unprimed glass surfaces following the above process excepting the application of primer. As previously explained, without the use of the primer the H shaped sample pieces showed minimal or no adhesion to the glass surface because they have no structural strength to adhere to the glass part. Unlike the above, H-shaped samples of the pre-cured silicone material adhered to the primed glass surface were adhered to the primed glass surface almost immediately after application. Such sample pieces were tested for physical characteristics using a Zwick tensiometer in accordance with ASTM D412-98a.

[0146] It was noted that H-shaped samples, tested 20 minutes after application to a primed glass surface as described above, exhibit an immediate green strength of about 0.02 MPa but adhesive failure is observed, while H-shaped samples tested 7 days after application gave comparatively higher tensile strength results and exhibited cohesive failure. The results of these physical tests are provided in Table 5 below.

TABLE-US-00005 TABLE 5 H pieces on glass cured after 7 days Tensile Elongation Modulus at Time after Strength at 12.5% application Mode of failure (MPa) break (%) elongation 20 minutes after Adhesive failure 0.02 6 application 20 minutes after Adhesive failure 0.03 8 application 20 minutes after Adhesive failure 0.04 11 application 7 days after Cohesive failure 0.08 26 0.04 application 7 days after Cohesive failure 0.06 26 0.04 application 7 days after Cohesive failure 0.05 22 0.04 application

Example 8

[0147] Cured materials were prepared by mixing the two components of the composition together in a Base: curing agent weight ratio of 1.5:1.

The base components were: [0148] 50 weight % of a 2,000 mPa.Math.s (at 25 C.) silanol terminated polydimethylsiloxane. [0149] 50 weight % of a 13,500 mPa.Math.s (at 25 C.) silanol terminated polydimethylsiloxane The curing agent components were: [0150] 50 weight parts of a 2,000 mPa.Math.s trimethoxysilyl terminated polydimethylsiloxane (at 25 C.), 50 weight parts of a 62,000 mPa.Math.s trimethoxysilyl terminated polydimethylsiloxane (at 25 C.) and [0151] 0.2 weight parts of tetra-n-butyl titanate.

[0152] The 2 parts were introduced into a speedmixer and then mixed therein 4 times for periods of 30 seconds at a speed of 2300 rpm. The resulting mixture was poured into a 2 meter long PVC U-shaped profile with internal dimension 1212 mm.sup.2 and was allowed to cure for 7 days at room temperature. The resulting cured material was cut at lengths of 50 mm and applied on substrates which had been pre-treated 2 minutes earlier using Dow Corning 1200 OS primer as the reactive interlayer coating composition in order to generate H-pieces for tensile testing. Such sample pieces were tested for physical characteristics using a Zwick tensiometer in accordance with ASTM D412-98a. The results of the tensile testing for the pre-cured condensation curable material are shown in table 6a, which highlights good to excellent adhesion of the pre cured spacer material onto various substrates. It was found that even after immersion in hot water, (Table 6b) adhesion remains excellent on non-plastic substrates, demonstrating the durable chemical adhesion of the pre-cured spacer product to such substrates, when applied thereon after it had been pre-treated with the reactive interlayer coating composition.

TABLE-US-00006 TABLE 6a Initial Results Tensile Adhesion strength Elongation at modulus at 100% Substrate (% CF) (MPa) break (%) elongation (MPa) Glass non tin 100 0.08 201 0.05 Glass tin 100 0.08 190 0.05 Anodized 85 0.05 125 0.05 aluminium PVC 100 0.06 140 0.05 PMMA 33 0.04 75 0.05

TABLE-US-00007 TABLE 6b Results after immersion for 1000 h at 45 C. Tensile Adhesion strength Elongation at modulus at 100% Substrate (% CF) (MPa) break (%) elongation (MPa) Glass non tin 100 0.05 109 0.05 Glass tin 100 0.06 155 0.05 Anodized 100 0.06 140 0.05 aluminium PVC 0 0.01 25 PMMA 0 0.01 9