GB2287951A

GB2287951A - A substance for forming a burnishable water-resistant coating

Info

Publication number: GB2287951A
Application number: GB9406519A
Authority: GB
Inventors: Christian Amaury Pier Lafrance; Benjamin Lesson
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-03-31
Filing date: 1994-03-31
Publication date: 1995-10-04
Also published as: GB9406519D0

Abstract

A substance for forming a burnishable water-resistant coating comprises a mixture including a colour powder (e.g. bronze gold-effect powder), wax (e.g. traffic wax-paste), size (e.g. acrylic size) and a carrier medium (e.g. a cellulose medium and cellulose thinner). The substance can be in the form of a cream, or diluted using appropriate thinners to form a sprayable medium.

Description

A SUBSTANCE FOR FORMING A BURNISHABLE WATER-RESISTANT COATING, PROCESS FOR THE MANUFACTURE THEREOF, METHOD FOR THE APPLICATION THEREOF. AND ARTICLES COATED THEREWITH The invention relates to a substance for forming a burnishable water-resistant coating, a process for the manufacture of the substance, a method of applying the substance to a surface of an article to be coated, and to articles incorporating a coating of the substance.

The substance is particularly, but not exclusively, suitable for applying a burnishable coating to picture frames for simulating gold leaf.

Traditionally, in order to achieve a gold leaf effect on a picture frame, it has either been necessary to use gold leaf or a gold leaf substitute, for example in the form of a metal leaf or a cream. A few different products are known for achieving a gold leaf-type effect on picture frames and the like. Durable gold leaf effects which are resistant to being dissolved or damaged by water can be achieved using, for example, oil- or wax-based products.

However, known products of this type cannot, effectively, be burnished. In order to achieve a burnishable gold-leaf effect, it has traditionally been necessary to use a waterbased product. However, known water-based products when applied to an article are not water-resistant and not sufficiently durable.

There is, accordingly, a need for a burnishable waterresistant coating for achieving a durable gold leaf and similar effects on picture frames and the like.

In accordance with one aspect of the present invention, there is provided a substance for forming a burnishable water-resistant coating when applied to an article, the substance including a colour powder, wax, size and a carrier medium.

Surprisingly, it has been found that a mixture of colour powder, wax, size and carrier medium enables a coating to be applied to an article which coating can be burnished and which, at the same time is water resistant.

Also, it has been found that the coating can be bluffed at any time to enhance or restore a burnish.

By a water-resistant coating is one which is resistant to being washed away by water and has a tendency to repel water in the manner of a waxed surface, so that it could be washed lightly with cold water without significant damage to the coating.

Preferably, the size is an acrylic size. Although acrylic size is water soluble, this appears to enhance the water resistant qualities of the substance without impairing its burnishing qualities.

Preferably, the carrier medium comprises a cellulose basic carrier medium. It has been found, surprisingly, that the acrylic size is not incompatible with the cellulose carrier and wax.

Preferably, the carrier medium comprises a thinner, more preferably a cellulose thinner, to give a consistency to the substance which makes it easy to apply and to enhance drying properties once applied to an article.

Preferably, wax in the form of a paste, more preferably a wax paste known as traffic wax paste, is used to give a consistency to the substance which makes it easy to apply.

The colour powder is preferably a metallic powder, for example a bronze powder for imitating gold leaf, although the invention is equally applicable to the application of other colours.

Advantageous results have been obtained with a substance including, in parts by weight: 1 part size, 2-4 parts wax, 1-3 parts colour powder, and carrier medium to achieve a desired consistency. For example, to form a cream, 7 to 10 parts carrier medium may be used, of which 2 to 6 parts can be a cellulose basic carrier medium, the reminder of cellulose thinners. For a sprayable substance, 2 to 6 parts basic carrier medium plus thinners can be used to provide a desired sprayable consistency.

In one particularly advantageous example, a substance in the form of a cream comprises, in approximate percentages by weight: 8% acrylic size, 13% bronze powder, 24% wax paste, 24% cellulose thinners and 31% cellulose medium, that is 16ml of acrylic size, 30g of bronze powder, 56g of wax paste, 60ml of cellulose thinners and 80ml of cellulose basic medium. A sprayable substance can be formed by the addition of thinners to such a cream to achieve a desired sprayable consistency.

In accordance with another aspect of the invention, there is provided a process for the manufacture of a substance as defined above comprising: (a) forming an initial mixture of carrier medium and size; (b) adding wax in a liquid state to the initial mixture; and (c) adding the colour powder.

Preferably, step (a) comprises adding measured quantities of size and thinners to a measured quantity of basic carrier medium and step (b) comprises heating the wax until it becomes liquid, adding the liquid wax to the initial mixture and allowing the resulting mixture to cool.

In accordance with a further aspect of the invention, there is provided method of applying a substance as defined above to an article comprising: (i) applying the substance to a surface of the article to be coated using a suitable application device; (ii) allowing the coating to dry; (iii) optionally repeating steps (i) and (ii) one or more times until a desired degree of coverage has been achieved; and (iv) burnishing the resulting coating with an agate burnishing tool and/or a soft cloth.

An agate burnishing tool, possibly in combination with a soft cloth, should provide the best results with regard to the degree of burnish obtainable.

Where the substance is in the form of a cream, the application device is preferably a soft brush or the like suitable for applying a cream. Alternatively, step (i) can comprise thinning the substance and applying the thinned substance using a spraying device. Where the substance is already in sprayable form, the application device is preferably a spraying device.

Where the surface to be coated is porous, the method preferably comprises an initial step of pre-coating the surface with a coating of burnishing clay.

The invention finds particular, but not exclusive application for providing a burnished or burnishable finish to picture frames.

The invention includes an article, e.g, a picture frame, comprising a surface with burnished or burnishable coating of a substance as defined above.

The invention will be described, by way of example only, with reference to an exemplary embodiment.

A preferred embodiment of the invention, which has been found to give particularly effective results, is in a form of a gold cream for applying a burnishable gold-effect finish to surfaces such as the mouldings of a picture frame. The gold cream comprises the following composition: 30 grams 'gold' bronze powder; 56 grams 'traffic' wax paste; 16ml (ca. 17.5 grams) acrylic size; 60ml (ca. 56 grams) cellulose thinners; 80ml (ca. 74 grams) cellulose medium.

Thus the cream comprises, in parts by weight, roughly 2 parts colour powder, 3 parts wax, 1 part size, 3 parts cellulose basic carrier medium, and 4 parts cellulose thinners; that is, in approximate percentages by weight: 13% bronze powder, 24% wax paste, 8% acrylic size, 24% cellulose thinners and 31% cellulose medium,.

The gold cream is manufactured in accordance with the following process: The cellulose medium is measured into a mixing container, to which measured quantities of acrylic size and cellulose thinners are added. The mixture is mixed until a milky colour is obtained.

The measured quantity of traffic wax paste is heated until it achieves a liquid state after which it is added to the milky coloured mixture. The resulting mixture is allowed to cool before mixing in the measured quantity of metallic powder.

The resulting gold cream can be applied to a suitable article (for example a picture frame moulding) using a soft brush (for example a sable brush). Preferably, particularly in the case of wooden picture frames which are porous, the picture frame moulding is coated with a burnishing clay and is finished so as to be clean and smooth before applying the gold cream. The gold cream is preferably applied using the tip only of the brush in a flicking style moving to and from until the required coverage is achieved.

The coated article (e.g. the picture frame moulding) should be allowed to dry for an appropriate time, typically 75 minutes, and then bluffed with an agate burnishing tool, and possibly with a soft cloth, to achieve a burnished finish. For a particularly high burnish finish, the coating should be polished lightly with an agate burnishing tool. The burnishing tool should be kept clean while work is in progress.

Rather than using a soft brush or other similar applicator, faster application of the gold coating can be achieved by thinning the cream using appropriate cellulose thinners and then using a conventional spraying device for applying the gold coating to the article.

Although a particular example of the invention has been described, it will be appreciated that may modifications and/or additions may be made within the scope of the invention.

Thus, for example, the composition of the substance may be modified as appropriate to achieve particular effects.

Rather than 30 grams of colour powder, the amount of colour powder could be reduced, for example within the range 30 to 15 grams in order to reduce the degree of coverage, or increased, for example within the range of 30 to 45 grams to provide a deeper colour coating. It should be noted that increasing the amount of colour powder can encourage flaking of the resulting coating.

The amount of wax used could be varied from 56 grams, e.g by increasing or decreasing the amount of paste by about 1/3 and still provide workable results.

Similarly, the amount of cellulose base medium used can be varied (e.g. by increasing or decreasing by 1/3) and still provide a workable product. The amount of cellulose thinner used can be varied over wide ranges in order to achieve the desired coatability and drying effects.

Increasing the amount of cellulose thinner increases the fluidity of the substance and can permit application by spraying and also enhances the drying properties. For example, a given volume of the gold cream described above could be thinned by the addition of the same volume of thinner for a spraying application. Reducing the amount of cellulose thinner means that the coating becomes progressively more viscous, and a significant reduction in the cellulose thinner can lead to longer drying times.

The invention is not limited to the use of a wax paste such a traffic wax paste. Other types of wax may be used instead, but they have not been found to be as effective or practical in use. Similarly, other ingredients may be used in place of the cellulose medium and thinners, e.g. medium and thinners based on acetone, trichloroethylene, etc, but shelf life is poor and the chemicals concerned are more dangerous. Acrylic size has been found to be the size giving the best results.

The invention can be used for applying other coloured coatings, in particular metallic powder coatings, and is not limited to the bronze powder for producing a burnishable gold effect.

Although the invention has been described particularly in the context of providing a gold leaf effect on picture frames, it is not limited thereto. As a result of its water-resistant properties and its durability, it finds application generally to providing burnishable coatings to surfaces and articles, not only for articles normally kept inside buildings, but also to articles normally kept outside buildings and to parts of the exterior of buildings.

Claims

1. A substance for forming a burnishable water-resistant coating when applied to an article, the substance including a colour powder, wax, size and a carrier medium.

2. A substance according to claim 1, wherein the size is an acrylic size.

3. A substance according to claim 1 or claim 2, wherein the carrier medium comprises a cellulose basic carrier medium.

4. A substance according to any one of the preceding claims, wherein the carrier medium comprises a thinner.

5. A substance according to claim 4, wherein the thinner is a cellulose thinner.

6. A substance according to any one of the preceding claims, wherein the wax is in the form of a paste.

7. A substance according to claim 6, wherein the wax paste is of a traffic wax paste.

8. A substance according to any one of the preceding claims, wherein the colour powder is a metallic powder.

9. A substance according to claim 8, wherein the colour powder is a metallic gold-coloured powder.

10. A substance according to claim 8 or 9, wherein the colour powder comprises bronze powder.

11. A substance according to any one of the preceding claims including, in parts by weight: 1 part size, 2 to 4 parts wax, 1 to 3 parts colour powder, and carrier medium to achieve a desired consistency.

12. A substance according to claim 11 in the form of a cream including by weight: 7 to 10 parts carrier medium.

13. A substance according to claim 11, wherein the carrier medium includes 2 to 6 parts cellulose medium.

14. A substance according to any one of the preceding claims in the form of a cream comprising, in approximate percentages by weight: 8% acrylic size, 13% bronze powder, 24% wax paste, 24% cellulose thinners and 31% cellulose medium.

15. A substance according to claim 11 in the form of a sprayable substance comprising 2 to 6 parts carrier medium plus thinners to provide a desired sprayable consistency.

16. A sprayable substance formed from a substance according to any one of claim 1 - 14 with the addition of thinners to achieve a desired sprayable consistency.

17. A process for the manufacture of a substance according to any one of the preceding claims comprising: (a) forming an initial mixture of carrier medium and size; (b) adding wax in a liquid state to the initial mixture; and (c) adding the colour powder.

18. A process according to claim 17, wherein step (a) comprises adding measured quantities of size and thinners to a measured quantity of basic carrier medium.

19. A process according to claim 17 or claim 18, wherein step (b) comprises heating the wax until it becomes liquid, adding the liquid wax to the initial mixture and allowing the resulting mixture to cool.

20. A method of applying a substance according to any one of claims 1 to 16 to an article comprising: (i) applying the substance to a surface of the article to be coated using a suitable application device; (ii) allowing the coating to dry; (iii) optionally repeating steps (i) and (ii) one or more times until a desired degree of coverage has been achieved; and (iv) burnishing the resulting coating with an agate burnishing tool and/or a soft cloth.

21. A method according to claim 20 for applying a substance according to any one of claims 1 - 14 wherein the application device is soft brush or the like suitable for applying a cream.

22. A method according to claim 20 for applying a substance according to any one of claims 1 - 14, wherein step (i) comprises thinning the substance and applying the thinned substance using a spraying device.

23. A method according to claim 20 for applying a substance according to claim 15 or claim 16, wherein the application device is a spraying device.

24. A method according to any one of claims 20 - 23, wherein the surface to be coated is porous and the method comprises an initial step of pre-coating the surface with burnishing clay.

25. A method according to any one of claims 20 - 24 wherein the surface to be coated is a picture frame.

26. An article comprising a surface with burnished or burnishable coating of a substance according to any one of claims 1 to 16.

27. A picture frame comprising a surface with burnished or burnishable coating of a substance according to any one of claims 1 to 16.

28. A substance substantially as hereinbefore described.

29. A process of making a substance substantially as hereinbefore described.

30. A method of applying a substance substantially as hereinbefore described.