GB2262938A - Simulated stained glass - Google Patents

Abstract

An article such as a sealed double glazing unit having spaced sheets of glass 2, 3, is adapted to simulate stained glass by having pieces of coloured plastics film 6 adhesively secured thereto. The film incorporates a u.v. blocker which is distributed throughout-the plastics to provide increased colour fastness and longer life at reduced cost. Various plastics could be used, although PMMA acrylic having an organic u.v. blocker bound into the macromolecule is preferred. <IMAGE>

Description

SIMULATED STAINED GLASS TECHNICAL FIELD OF THE INVENTION This invention relates to simulated stained glass articles such as single pane windows, double or triple pane sealed glazing units, mirrors and the like.

BACKGROUND US Patent No. 4 312 688 discloses a method of making simulated stained glass in which individual pieces of coloured plastics film are cut to size and adhesively secured to adjacent areas of a glass sheet, and the junctions between adjacent areas are covered by lengths of lead strip. This basic process has now gained widespread acceptance in the double glazing and similar industries.

The most common film material which is used in such applications is polyester film. The film is normally clear (i.e. non-coloured) and the colour is applied by screen printing or by a pigment carried in a gelatin layer on the surface of the film.

Colour stability of such films is of prime importance because translucent colours tend to fade when exposed to ultra violet (u.v.) light. Polyester films used hitherto afford no protection to the pigmentation, but limited protection may be added by provision of an additional protective layer or surface treatment, at extra cost.

As an alternative to polyester film, polyvinyl chloride (PVC) film has sometimes been used to create simulated stained glass, but this is limited to short-term usage.

PVC films incorporate softeners which result in shrinkage. In addition, they do not retain their form during processing and they are not colour-fast. PVC films also cause fogging and condensation inside sealed units, and tend to be unstable at higher temperatures.

An aim of this invention may be viewed as being to provide an improved alternative to the film hitherto employed, by providing additional protection against the effects of u.v. light for the pigments used in the product.

SUMMARY OF THE INVENTION The present invention proposes a simulated stained glass article comprising a sheet of glass or equivalent light-transmitting material, a plurality of individually shaped pieces of coloured plastics sheet adhesively secured to areas of said sheet of glass or equivalent to provide stained glass colour characteristics, each of said individually shaped pieces being bordered by lead strip or its equivalent, the article being distinguished by the fact that each of the individually shaped pieces comprises a plastics having a u.v. blocker substance distributed throughout the plastics material.

Since the u.v. blocker substance is integrally incorporated into the material during manufacture the film can be relatively inexpensive to produce as compared with post treated polyester film. On the other hand, the material can be as good as, or better than, post treated polyester film at blocking u.v.

light, depending upon the nature and amount of the u.v.

blocker which is used.

Although various inorganic additives could be used as u.v. blockers, organic substances are preferred. The blocker is preferably incorporated into the macromolecules of the plastics polymer, or otherwise integrated into the molecular structure, so that the u.v. absorber remains bound and does not evaporate even when the plastics is exposed to high temperatures, and stability is maintained when the film is exposed to light.

The blocker could act by absorbing u.v. light or it could act to reflect u.v. light.

The film material could incorporate various plastics, depending upon the properties which are required. By way of example, acrylics, polyesters, polyvinyl chloride (pvc), polyvinyl fluoride (pvf) and polypropylene could be used, alone or mixed in laminations.

The preferred material is a form of acrylic, more particularly an impact modified polymethyl methacrylate (PMMA) incorporating an organic u.v. absorber system in the macromolecule. The best material of this kind which has so far been identified is Plexiglas 99845, manufactured by Roehm Limited. The transmittance of this material in the u.v. region of the spectrum (290 to 370 nm) is less than 2% whereas, in contrast, its transmittance in the visible region (380 to 780nm) is about 92%. Thus, more than 98% of the incident u.v.

light is absorbed by the material.

Plexiglas 99845 material has also been found to be superior to, or at least as good as post treated polyester film or PVC in a number of other important respects: * It can be coloured by offset lithographic, screen process, or flexographic printing techniques.

* It exhibits good weather resistance.

* It does not turn yellow and remains clear even if it absorbs moisture.

* It does not become brittle with age.

* It is scratch-resistant so that its use is not restricted to internal use in double glazing units.

* It is stable over the temperature range normally encountered in glazing systems.

* It can be used externally or internally on single or double/triple glazed units.

* It can be produced in textured finishes, e.g. to give sand blasted, etched or frosted glass effects.

* It can be metallised if required.

* It is highly resistant to crease whitening.

* It does not emit any solvent or monomer vapours which could, for example, cause problems in a sealed double glazing unit.

* It is impact resistant and therefore easy to fabricate.

The invention also provides a method of producing a simulated stained glass article, comprising: - forming a plurality of individually shaped pieces from one or more sheets of coloured stock material to correspond with individual surface areas of a sheet of glass or equivalent light-transmitting material, - securing, by means of an adhesive, said individually shaped pieces to the corresponding surface areas of said sheet of glass or its equivalent, and - forming a border around each of the individually shaped pieces by means of lead strip or its equivalent, the method being distinguished by the fact that the individually shaped pieces are formed from plastics stock having a u.v. blocker substance distributed throughout the plastics material.

The invention further provides plastics film material for use in making a simulated stained glass article, comprising a layer of plastics material having a u.v.

blocker substance distributed throughout the material, a layer of adhesive applied to a surface of said plastics layer, and a surface pigment applied to said plastics layer.

The adhesive layer and the surface pigment may be applied to opposite surfaces of the plastics layer.

The film material preferably includes a further layer of plastics material having a u.v. blocker substance distributed throughout the material, with the pigment layer sandwiched between the two plastics layers.

Hence, the pigment(s), protected from u.v. light on both sides, will have a greatly reduced tendency to fade.

The adhesive layer and the surface pigment may alternatively be applied to the same surface of the plastics layer.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is exemplified in the accompanying drawings, in which: Figure 1 is a plan view of a sealed double glazing unit of the invention, and Figure 2 is a section through part of the glazing unit.

DETAILED DESCRIPTION OF THE DRAWINGS A double glazing unit l includes two spaced sheets of clear glass 2, 3 which are sealed around their periphery to a spacer bar 4, in known manner. During manufacture, a design 5 is formed on the unit using a process which will now be described.

A number of individually sized pieces 6 are cut from sheets of coloured visible-light-transmitting stock material using a suitable template. The stock material is formed of Plexiglas 99845 acrylic film (e.g. 0.06 mm thick) which incorporates an integral u.v. absorber.

The film is coated on one side with a pressuresensitive adhesive which is protected during handling by a peel able backing. The film may be self-coloured by incorporation of a pigment which is distributed throughout the film in the same way as the u.v.

absorber or it may have a pigment applied externally by screen printing for example. Normally, as in this example, the pigment will be applied to the surface which is opposite to the adhesive coat, although the pigment may be applied to the adhesively-coated surface if desired, either in a separate coat prior to application of the adhesive or incorporated into the adhesive layer. The colouring may be multi-stage to enable multi-coloured designs to be produced on a single layer of plastics film. The film may also be over-laminated with additional layers of acrylic film or alternative materials. The pigment may either be applied to the base film or to the over-laminate/s.

After removing the protective backing to expose the adhesive layer, each piece 6 is secured in the required position to one of the glass sheets 2 by means of the adhesive. Normally, the pieces 6 will be secured to the surface which will be disposed inside the sealed unit, facing the other sheet of glass 3 as shown.

However, because of the hard-wearing properties of Plexiglas 99845, the pieces could alternatively be secured to an exposed outer surface of the glazing unit. The pieces 6 may either closely abut each other at their edges or they may overlap slightly as shown in Fig. 2. If desired, a suitable lubricant such as water may be interposed between the glass sheet 2 and the adhesive layer to render the adhesive temporarily inactive and permit the accurate positioning of the pieces. In this case, when the pieces 6 are correctly positioned the water is squeezed out and the film allowed to dry.

A border is formed around each of the individual pieces 6 by adhesively securing lead, plastics or metal strip 7 over the junctions between the pieces. The strip is boned using a suitable tool in known manner to ensure that it conforms closely to the profile of the underlying surfaces and forms a good bond thereto.

This is repeated on the opposite side of the glass sheet 2 using similar adhesively-secured strips 8 arranged to coincide with the strips 7, with boning applied as necessary.

In the illustrated example the finished glazing unit is normally mounted with the pane 2 exposed to daylight, e.g. facing the outside of a building. Thus, light must pass through the film 6 which filters out most of the ultra-violet light before it reaches the pigment layer. The pigment(s) is/are thus protected from the effects of u.v. light, minimising any tendency for the colour to fade.

In cases where self-pigmented films are used the exposure of the pigment to ultra violet light is similarly reduced by the u.v. absorber. In such cases, it does not matter which surface of the film receives the ultra violet light. Thus, the film could be applied to an inside surface of the glazing panel or an external surface. In both cases, either side of the glazing panel could be exposed to daylight.

When film having a surface pigment layer is applied to an external surface of the glazing unit it is desirable that the film is interposed between the light source and the pigment, so that the film will usually be applied to the surface which is exposed to an internal room of a building. However, where u.v. exposure is at a relatively low level, or where pigment deterioration is not a problem, the film could be exposed to the exterior of a building. Over-lamination with a second layer of acrylic with a u.v. blocker allows the composite film laminate to be mounted with either side exposed to the sunlight, affording protection from both sides. Thus, the film could be applied to an internal or external surface of the panel, with either side of the panel exposed to daylight.

The above-described process could of course be used with triple-sheet glazing units or with single sheet glazing or other simulated stained glass articles.

Light-transmitting plastics or other materials could also be used in place of glass sheets.

In certain applications it may be desirable to apply two or more layers of film on top of each other, e.g.

to create additional colours, with each film secured by its adhesive backing.

The following plastics films which incorporate distributed u.v. blockers have also been identified as being suitable for use in the above-described process: Acrylic films: - KORAD 05001 sold by polymer Extruded products, Inc.

- SHINKOLITE HBS 001 sold by Mitsubishi Rayon Co.

Limited Polyester films: - FOLEX GO CL UVR - Courtaulds NR9OSRPS2 - MADICO CLS 200 X Polyvinyl fluoride films: - TEDLAR XLR sold by Du Pont - EXCELAR XLR sold by Brady Composite PVC/PET (polyester) laminates: - BELBIEN sold by CI Kasei Co. Limited - BELEX sold by CI Kasei Co. Limited Polypropylene films: - Various manufacturers.

Claims (35)

1. A simulated stained glass article comprising a sheet of glass or equivalent light-transmitting material, a plurality of individually shaped pieces of coloured plastics sheet adhesively secured to areas of said sheet of glass or equivalent to provide stained glass colour characteristics, each of said individually shaped pieces being bordered by lead strip or its equivalent, the article being distinguished by the fact that each of the individually shaped pieces comprises a plastics having a u.v. blocker substance distributed throughout the plastics material.

2. A simulated stained glass article according to Claim 1, in which the u.v. blocker is an organic substance.

3. A simulated stained glass article according to Claim 2, in which the u.v. blocker substance is bound into the molecular structure of the plastics polymer.

4. A simulated stained glass article according to Claim 1, 2 or 3, in which the u.v. blocker substance acts to absorb light in the u.v. region of the spectrum.

5. A simulated stained glass article according to Claim 1, 2 or 3, inrwhich the u.v. blocker substance acts to reflect light in the u.v. region of the spectrum.

6. A simulated stained glass article according to any preceding claim, in which said plastics material comprises an acrylic plastics.

7. A simulated stained glass article according to Claim 6, in which the acrylic plastics comprises a polymethyl methacrylate.

8. A simulated stained glass article according to any of Claims 1 to 5, in which the said plastics material comprises a polyester.

9. A simulated stained glass article according to any of Claims 1 to 5, in which the said plastics material comprises polyvinyl chloride.

10. A simulated stained glass article according to Claim 8 or 9, in which the individually shaped pieces comprise a ami laminate of polyvinyl chloride and polyester film.

11. A simulated stained glass article according to any of Claims 1 to 5, in which the said plastics material comprises polyvinyl fluoride.

12. A simulated stained glass article according to any of Claims 1 to 5, in which said plastics material comprises polypropylene.

13. A simulated stained glass article according to any preceding claim, in which the individually shaped pieces are each provided with a surface layer which comprises a pigment.

14. A simulated stained glass article according to Claim 13, in which the pigment layer is applied to the opposite surface of said pieces to said adhesive.

15. A simulated stained glass article according to Claim 13 or 14, in which the article comprises a sealed glazing unit and said pieces are applied to an internal surface of said unit.

16. A simulated stained glass article according to any of Claims 1 to 12, in which each of the individually shaped pieces comprises a laminate of two layers of plastics material having a u.v. blocker distributed throughout the plastics material, and an intermediate layer which comprises a pigment.

17. A simulated stained glass article according to any of Claims 1 to 12, in which the individually shaped pieces each have a pigment distributed throughout said plastics material.

18. A method of producing a simulated stained glass article, comprising: - forming a plurality of individually shaped pieces from one or more sheets of coloured stock material to correspond with individual surface areas of a sheet of glass or equivalent light-transmitting material, - securing, by means of an adhesive, said individually shaped pieces to the corresponding surface areas of said sheet of glass or its equivalent, and - forming a border around each of the individually shaped pieces by means of lead strip or its equivalent, the method being distinguished by the fact that the individually shaped pieces are formed from plastics stock having a u.v. blocker substance distributed throughout the plastics material.

19. Plastics film material for use in making a simulated stained glass article, comprising a layer of plastics material having a u.v. blocker substance distributed throughout the material, a layer of adhesive applied to a surface of said plastics layer, and a surface pigment applied to said plastics layer.

20. Plastics film material according to Claim 19, in which said adhesive layer and said surface pigment are applied to opposite surfaces of said plastics layer.

21. Plastics film material according to Claim 20, in which the film material includes a further layer of plastics material having a u.v. blocker substance distributed throughout the material, with the pigment layer sandwiched between the two plastics layers.

22. Plastics film material according to Claim 19, in which said adhesive layer and said surface pigment are applied to the same surface of said plastics layer.

23. Plastics film material according to any of Claims 19 to 22, in which the u.v. blocker is an organic substance.

24. Plastics film material according to Claim 23, in which the u.v. blocker substance is bound into the molecular structure of the plastics polymer.

25. Plastics film material according to any of Claims 19 to 24, in which the u.v. blocker substance acts to absorb light in the u.v. region of the spectrum.

26. Plastics film material according to any of Claims 19 to 24, in which the u.v. blocker substance acts to reflect light in the u.v. region of the spectrum.

27. Plastics film material according to any of Claims 19 to 26, in which said plastics material comprises an acrylic plastics.

28. Plastics film material according to Claim 27, in which the acrylic plastics comprises a polymethyl methacrylate.

29. Plastics film material according to any of Claims 19 to 26, in which the said plastics material comprises a polyester.

30. Plastics film material according to any of Claims 19 to 26, in which the said plastics material comprises polyvinyl chloride.

31. Plastics film material according to any of Claims 19 to 26, in which the said plastics material comprises polyvinyl fluoride.

32. Plastics film material according to any of Claims 19 to 26, in which the said plastics material comprises polypropylene.

33. A simulated stained glass article substantially as described herein.

34. A method of producing a simulated stained glass article substantially as described herein.

35. Plastics film material for use in forming a simulated stained glass article, substantially as described herein.