GB2515265A

GB2515265A - Resinous compositions

Info

Publication number: GB2515265A
Application number: GB1308049.4A
Authority: GB
Inventors: Alan James Dodds
Original assignee: INDENTICAL Ltd
Current assignee: INDENTICAL Ltd
Priority date: 2013-05-03
Filing date: 2013-05-03
Publication date: 2014-12-24
Also published as: GB201308049D0

Abstract

A resin composition comprising 10-40% by weight an acrylic resin in dispersed form, such as styrene/acrylic ester copolymer, such as Revacryl (RTM) 245; 2-8% by weight lime putty; and/or 0.4-5% by weight non-ionic urethane, such as Acrysol (RTM) RM825; and/or 14-40% by weight kaolin; and optionally salt; water, and optionally 25-75% by weight one or more powdered materials, such as masonry or ceramic materials. The resin compositions are used for external or internal coatings of buildings.

Description

RESINOUS COMPOSITIONS

Field of the Invention

The present invention relates to novel and inventive resinous compositions comprising an acrylic resin in dispersed form, lime putty, and/or non-ionic urethane and/or kaolin as a base for the preparation of materials for use in external or internal building or construction projects. More particularly, the present invention relates to coating compositions comprising an acrylic resin in dispersed form, one or more powdered material(s), lime putty, and/or non-ionic urethane and kaolin, processes for their manufacture and their utility as surface coating or moulding materials having unique strength and versatility.

Background of the Invention

At the present time, essentially any available materials can be used for external or internal projects, according to the finish desired by the architect or designer and the project budget. However, with increased awareness of the environmental impact of our rate of consumption of natural resources, it would be highly desirable to provide materials for the building and construction trade fashioned from recycled materials, or from materials provided as by-products.

In the building trade and construction industry there has always been a necessary trade-off between the desire to use high-quality, high-finish natural materials, such as marble, sandstone and the like versus the cost of sourcing these materials, particularly where they are not available from local suppliers. An additional problem for building owners is the maintenance of the finish-levels of such materials. This is a particular concern with older buildings, and especially those of historical significance, where there may difficulties in sourcing materials in sufficient quantities to repair the buildings.

With the ever increasing demand on natural resources, alternative materials for both external and internal utility which have the high-quality and high-finishes of such natural materials are in great demand. It would be highly desirable to provide alternative products, particularly using recycled materials which have improved finish capabilities versus the original natural material, such as for example, polish-able sandstone. For ease-of-adoption across the different environments where such materials are used, construction sites, building maintenance and repair projects, interior design and decorating projects, it would be highly desirable to provide alternative products, particularly including recycled materials, in a suitable manner for use according to the volume desired for any particular project.

Historically, buildings utilised natural materials which were close to hand for the external structural features, whilst internal, more decorative features, such as for example fireplace surrounds, or decorative panels may have been fashioned from more high-finish materials such as imported marble, or ceramics. Recycling materials was common practise in the past, where bricks or stones from disused or derelict vernacular buildings were incorporated into newer buildings either as foundations or for re-building purposes. In the modern day, this poses a particular problem for the repair and maintenance of such traditional buildings where the same range of materials may no longer be readily available.

Thus, it would be desirable to provide products which incorporate recycled materials for use in repair and maintenance of traditional buildings.

It is an object of at least one aspect of the present invention to obviate or mitigate at least one or more of the aforementioned problems in relation to the utility of high-quality, high-finish natural materials for use in external or internal building, construction, repair or interior design projects.

It is an object of at least one aspect of the present invention to provide novel recycled materials from a base resinous mix having desirable finish properties which are suitable for both external and internal use.

It is an object of at least one aspect of the present invention to provide a resinous base comprising styrene acrylic copolymer, lime putty, and/or non-ionic urethane and/or kaolin for mixture with recycled materials, preferably in powdered form, to provide recycled materials for utility in external or internal building, construction, repair, or interior design projects.

It is a further object of at least one aspect of the present invention to provide a resinous base comprising styrene acrylic copolymer, lime putty, and/or non-ionic urethane and/or kaolin for mixture with masonry or ceramic materials, preferably in powdered, to provide new materials for utility in external or internal building, construction, repair, or interior design projects having desirable strength, robustness and finishing properties.

The Applicant has developed novel and inventive resinous compositions for utility in the preparation of new recycled materials for use in external or internal building, construction, repair or interior design projects, said compositions comprising styrene acrylic copolymer, lime putty, and/or non-ionic urethane and/or kaolin for mixture with materials, including recycled materials, preferably in powdered form. The Applicant has also developed tailored products using said resinous compositions comprising powdered materials which are suitable for use as external coatings, external renders, external moulding materials internal coatings, or internal moulding materials. The Applicant has also developed processes for the preparation and utility of said resinous compositions comprising powdered materials.

Summarq of the Invention The Applicant has developed novel and inventive resinous compositions comprising acrylic resin in dispersed form, lime putty, and/or non-ionic urethane and/or kaolin as a base for the preparation of materials for use in external or internal building or construction projects.

Accordingly the present invention provides resinous compositions for use a base for the preparation of materials for use in external or internal building or construction projects comprising: (a) acrylic resin in dispersed form; (b) lime putty; and/or (c) non-ionic urethane; and/or (d) kaolin; and optionally (e) salt; and (f) water.

The present invention provides resinous compositions suitable for use as external coatings comprising: (a) acrylic resin in dispersed form; (b) lime putty; (c) non-ionic urethane; (d) kaolin; (e) salt; (f) one or more powdered materials; and (g) water.

The present invention provides resinous compositions suitable for use as external renders comprising: (a) acrylic resin in dispersed form; (b) lime putty; (c) salt; (d) one or more powdered materials; (e) sand; and (f) water.

The present invention provides resinous compositions suitable for use as internal coatings comprising: (a) acrylic resin in dispersed form; (b) non-ionic urethane; (c) kaolin; (d) one or more powdered materials; and (e) water.

The present invention provides resinous compositions suitable for use as internal coatings comprising: (a) acrylic resin in dispersed form; (b) kaolin; (c) one or more powdered materials; and (d) water.

As detailed hereinafter the present invention additionally provides resinous pre-mix compositions, and resinous rendering compositions, as well as resinous stone set compositions in dried form suitable for use as ready-to-mix products for the preparation of external or internal coating materials.

As demonstrated in the Examples hereinafter the Applicant has found that the resinous compositions of the present invention are highly suited for use as bases for the provision of new coating or moulding materials for external or internal use.

In particular the Applicant has surprisingly found that surfaces treated with the resinous compositions of the present invention can be easily sanded, and polished.

According to a further aspect the present invention provides for the use of the resinous compositions as bases mixes for combination with powdered material for the preparation of novel coating or moulding compositions.

The Applicant has also developed a novel process for the preparation of the compositions according to the invention. According to a further aspect the present invention provides a process for the preparation of resinous compositions comprising one or more powdered materials suitable for use as external or internal coatings or mouldings wherein said process comprises the steps of: (i) mixing together acrylic resin in dispersed form; lime putty; and/or non-ionic urethane; and/or kaolin; and optionally salt; and water to form an aqueous premix; (ii) combining said aqueous premix with one or more powdered materials, and optionally additional water, or sand to provide a resinous composition suitable for use as an external or internal coating, external render, or moulding material; and optionally (ih) drying said coating, render or moulding material.

Detailed Descrirtion The novel compositions according to the present invention are resinous compositions comprising an acrylic resin in dispersed form, lime putty, and/or non-ionic urethane and/or kaolin suitable for use as a base for the preparation of compositions for use as external or internal coatings or moulding materials in building or construction projects.

Suitable acrylic resins in dispersed form for use herein include surfactant stabilised dispersions! and particularly surfactant stabilised, styrene / acrylic ester copolymer dispersions are used herein. REVACRYL R 245, a fine particle size, surfactant stabilised dispersion available from Synthomer is especially preferred. REVACRYL R 245 from alternative commercial providers may equally be used herein. The level of acrylic resin in dispersed form, or surfactant stabilised styrene I acrylic ester copolymer dispersion, or particularly REVACRYL R 245 used in the preparation of the aqueous resinous base compositions according to the invention is between about 40% to about 80% by weight of the total base composition. As detailed in the Examples herein, this corresponds to a relative amount of from about 45% to about 80%, from about 50% to about 77% of acrylic resin, and in particular REVACRYL R 245 in dispersed form in aqueous mixes for use in coatings, renders or liquid-stone products. The level of resin, as defined herein before present in the final coatings, renders or mouldable products is between about 10% to about 40%, between about 11% to about 36%.

According to a further aspect the present invention provides resinous compositions for use a base for the preparation of materials for use in external or internal building or construction projects comprising: acrylic resin in dispersed form, surfactant stabilised styrene / acrylic ester copolymer dispersion; a non-ionic urethane; salt; lime putty; and water wherein said copolymer is present at between about 40% to about 80% by weight of the total base composition, and preferably wherein said copolymer is REVACRYL R 245.

Any lime putty, also known as non-hydraulic lime, or fat-lime", may be used in the resinous compositions herein. For the avoidance of doubt the terms lime putty, non-hydraulic lime and fat-lime may be used interchangeably in respect of the resinous compositions herein. Any lime putty made from either calcium-based limestone, or dolomitic limes based on calcium magnesium carbonate may be used. Preferably non-hydraulic limes based on calcium-based limestone having calcium hydroxide levels of greater than or equal to about 95% may be used, and/or which absorb nearly their own weight in CO2 may be used. The level of lime putty, and in particular white non-hydraulic lime based on calcium-based limestone, used in the preparation of the resinous base compositions according to the invention is between about 2% to about 8%, from about 4% to about 7%, from about 5% to about 6%, about 5% by weight of the total resinous base composition. As detailed in the Examples herein, this corresponds to a relative amount of from about 0.3% to about 1.5%, between about 0.4% and about 1.3%, between about 0.6% and about 1.1% of lime putty in in external or internal coatings.

According to a further aspect the present invention provides resinous compositions for use a base for the preparation of materials for use in external or internal building or construction projects comprising: acrylic resin in dispersed form, , lime putty, and/or non-ionic urethane and/or kaolin wherein said lime putty is present at between about 2% to about 8%, from about 4% to about 7%, from about 5% to about 6%, about 5% by weight by weight of the total resinous base composition, and preferably wherein said lime putty is white non-hydraulic lime based on calcium-based limestone. According to a further aspect said acrylic resin is a surfactant stabilised styrene / acrylic ester copolymer dispersion styrene acrylic copolymer, and particularly Revacryl R 245.

Salt as defined herein includes salt-alternatives such as sea-salt, or alternative metal halides such as potassium chloride as well as sodium chloride salt, and are present at levels of between about 0.1% to about 1%, between about 0.2% to about 0.5%, between about 0.3% to 0.4% by weight of the external coating or renders according to the present invention.

As detailed in the Examples herein, this corresponds to a relative amount of from about 0.1% to about 3%, from about 0.5% to about 2.5%, from about 1% to about 2% of salt in the aqueous pre-mixes for combination with one or more powdered material(s) to prepare external coatings or renders. Sodium chloride is preferred.

Kaolin, also known as china clay, or clay as defined herein optionally utilised in the aqueous base mixes herein is between about 15% to about 40%, from about 20% to about 30% by weight of the total base composition. As detailed in the Examples herein, this corresponds to a relative amount of between about 4% to about 25%, between about 5% and about 22%, between about 6% and about 20% of kaolin in coatings, or liquid-stone products as defined herein.

Non-ionic urethanes are preferred thickening agents for use herein and are, optionally utilised in the base mixes herein. Non-ionic urethanes having rheology modifying properties are preferred for use herein, and ACRYSOLTM RM-825 available from Dow is especially preferred. ACRYSOLTM RM-825 from alternative commercial providers may equally be used herein. The level of non-ionic urethane, and in particular ACRYSOLTM RM- 825 used in the preparation of the resinous base compositions according to the invention is between about 2% to about 5%, from about 2% to about 4%, from about 2.5% to about 3% by weight of the total base composition. As detailed in the Examples herein, this corresponds to a relative amount of from about 0.4% to about 5%, between about 0.5% to about 4%, between about 0.7% to about 3% of non-ionic urethane in coatings, renders or liquid-stone products as defined herein.

According to an aspect, thickening agents, having comparative rheology modifying properties to Acrysol RM-825 may be utilised to provide alternative coatings.

According to a further aspect the present invention provides resinous compositions for use a base for the preparation of materials for use in external or internal building or construction projects comprising: an acrylic resin; a non-ionic urethane; salt; lime putty; and water wherein said urethane is present at between about 2% to about 5% by weight of the total base composition, wherein the levels of said salt, lime, water and resin are as defined hereinbefore, and preferably wherein said urethane is ACROSOLTI RM-825. According to a further aspect said acrylic resin is a surfactant stabilised styrene I acrylic ester copolymer dispersion styrene acrylic copolymer, and particularly Revacryl R 245.

For the avoidance of doubt, where the actual or relative amounts of water in any particular composition according to the invention described herein are not specified it should be understood that the actual or relative amount of water required will be that sufficient to reach either 100% of composition, either by weight or relative volume. Water may be used either in purified, or distilled form, or from regular supply.

As detailed herein before the resinous internal and/or external coating, rendering or moulding compositions according to the present invention comprise powdered material. Any masonry or ceramic material which can be powdered is suitable for use in combination with the aqueous resinous base compositions (pre-mixes) according to the present invention, to provide external coatings or renders, internal coatings or liquid stone products. Suitable materials include: any natural material which can be quarried, and turned into a powder, such as stone, granite, slate, sandstone, marble, or man-made ceramics or other building materials such as bricks, or pre-con/pre-cast blocking, or any material where dust is a by-product.

The term powder as defined herein for the description of the form of said powdered material includes: dust, fine particulate, crushed, ground, granular, pulverized, or pounded.

Powdered materials of varying particle-size distributions (PSD5), also known as grain size distribution, may be used herein from coarse to fine, or superfine. Any suitable method may be used to categorise powder particle size, such as for example by sieve analysis, wherein powder is separated on sieves of different sizes. Powders having a size between from 0.01, to about 50, between from about 0.05 to about 20, or between from about 0.1 to about 10 microns (pm) in size may be used. Alternatively, suitable powders can be obtained according to their ability to penetrate flour sieves. Suitable flour sieves for providing powders for use herein including: 1 in 32 flour sieves; flour sieves having a standard 10 mesh sizes; or fine 50 mesh sizes. Powdered materials can be either independently sourced from any suitable commercial supplier, or may be prepared in situ, or in advance, and incorporated into the resinous compositions according to the processes detailed hereinafter to provide compositions for internal and/or external use.

Powdered material(s) are present in the external or internal coatings, renders or moulding materials herein at between about 25% and about 75% by weight. For external coatings or renders, or mouldable materials the level of powdered material(s) is between about 50% to about 75%, between about 55% to about 69%. For internal coatings the level of powdered material(s) is between about 20% to about 35%, between about 25% to about 30%, about 28.6%.

For many reasons such as environmental-sensitivity, historical significance, cost of sourcing replacement materials, it would be highly desirable to be able to repair and/or restore internal and/or external surfaces with the same masonry or ceramic material(s), which has been exposed to the same weathering, or other environmental conditions, as the material(s) used in the original construction. It would be particularly desirable to be able to repair and/or restore internal and/or external surfaces with the same materials which have been exposed to the same weathering, or other environmental conditions, as the material(s) used in the original construction. It would be especially desirable to be able to prepare, and use such compositions on-site. Hitherto the development of the Applicant's unique resinous compositions it has simply not been possible to: routinely prepare compositions from the same masonry or ceramic material(s); routinely prepare compositions for repair and/or restoration purposes from masonry or ceramic materials which have been exposed to the same weathering, or other environmental conditions as the material(s) used in the original construction; to routinely prepare such compositions on-site.

An advantage of the use of the resinous compositions additionally comprising powdered materials, and particularly where recycled powdered materials are utilised, is that in repair or restoration projects, such as for example in building(s), structure(s) or part(s) thereof of historical or architectural significance, is that the repaired and/or restored surface(s) are strong, robust and will have essentially similar weathering capabilities to the remaining un-restored and/or un-repaired surface(s). As detailed in the Examples hereinafter resinous compositions comprising powdered material according to the invention can be applied surfaces directly, or can be moulded, and or sculpted to provide architectural features. Where such surfaces or features are prepared as part of a larger repair or restoration project it has been found that use of the resinous compositions comprising powdered material according to the invention deliver a highly desirable degree of consistency with the remaining (unrepaired) original surface, such as for example in terms of texture and colour.

Most surprisingly the Applicant has found that the surface(s) and or architectural features provided by use of the resinous compositions additionally comprising powdered materials herein are sufficiently strong and robust to be sanded and/or polished. For example, granite or stone marble can be added to the resinous mixtures as detailed herein to provide internal and or external coatings which can then be sanded, providing stone marble or granite-like coatings which can also be polished to provide a surface to all intents and purposes indistinguishable, to the naked eye, from the original solid material, but using more environmentally-friendly materials, providing a more flexible approach to building design, providing an efficient method for delivering high-end surfaces providing strong and robust surfaces, all at a fraction of the cost of the original solid.

Remarkably! surfaces coated with resinous compositions comprising sandstone as the powdered material have improved strength and robustness versus the original material, and in particular may be routinely sanded or polished. Thus, use of the resinous compositions comprising powdered material(s) provides improved materials which may be suitable for additional utility versus the original. For example, plasters and coatings including said any of the powdered materials detailed herein are now possible. As detailed hereinbefore the astonishing strength of the resinous compositions comprising powdered material means that they can be applied, or painted or otherwise use to coat any suitable surface to provide a "liquid stone' surface, which when dried can be sanded, and or polished to provide a strong surface, having unprecedented applications over the original material, such as for example large-scale marble-effect projects, utility of polished sandstone, new paint-products, and the like. In addition the resinous compositions comprising powdered material as provided herein can be used to provide strong and robust coatings or renders based on natural materials in areas which were hitherto impossible such as for example strips of walls, architectural features, pillars, ceilings and the like. It is further proposed herein that use of the unique coatings and/or renders herein may have additional environmental advantages for the structures onto which they are applied because their unique porosity may obviate, or mitigate the effects of, dampness.

An unprecedented additional advantage provided by the resinous compositions comprising powdered material according to the invention are that composites mixtures of more than one powdered material, such as for example mixtures or two or more of marble, sandstone, slate, granite, brick, and/or further powdered materials as defined herein can be produced to make unique hybrid stone finishes which have never been seen before, which have new and improved properties versus the original materials. An additional advantage of using more than one powdered material in an resinous composition herein, to provide a so-called hybrid material, is that the relative amount of resin may be reduced in relation to the remaining materials where a relatively impermeable powder, such as for example marble, is mixed with a relatively permeable powdered material, such as for example sandstone. A yet further advantage of the use of the unique hybrids provided by the processes herein is that Applicant has found that resinous rendering compositions having improved strength, and/or increased porosity can be prepared by selection of particular hybrids without the need to increase the level of non-ionic or polymer. Such hybrids for use in rendering compositions in particular include: mixtures of sandstone powder with marble powder or granite powder; mixtures of brick powder with marble powder or granite powder. Whilst certain combinations have been named, further combinations of the powdered materials as detailed herein are considered to be included within the spirit and scope of the present invention, including both combinations of two, or three or four or more different powders.

Resinous compositions as defined herein including one or more powdered materials can be applied to any suitable external surface to provide a coating, such as for example concrete, pre-existing brick-work, stone-work or other natural material, or to internal surfaces such as for example polystyrene coving, walls of gyproc, wood, or other internal surfaces to provide a coating having the strength and robustness of stone, with unique finish properties including their ease of, and robustness to, sanding and polishing. Surprisingly the Applicant has found that the coatings herein, once applied to the surface of choice may easily be sanded via gentle sanding with a 120-or 150-grit sand paper such as those suitable for use on painted surfaces, as opposed to the heavy duty p16 carbarundum silica wheeled industrial machinery commonly used to sand the natural (non-powdered) original material.

Furthermore, the Applicant has found that enhanced results are achieved when the surface is dampened with water prior to sanding, and in addition that this damping, then sanding has beneficial impact on the polish-ability of the so-prepared surface. For the avoidance of doubt, dampening may be achieved via any suitable means, including, sponging, spraying, wetting with a cloth or the like.

Resinous compositions as defined herein including one or more powdered materials can be applied to any suitable substrate to provide a unique coated, or rendered substrate suitable for use as cladding, facing, shell, covering or layering of one or more external or internal walls, or ceilings, or parts thereof. Suitable substrates include those typically used for external or internal wall or ceiling construction where available in block, panel, slab, tablet, sectional, panel, or other form suitable for use to construct a facing. Exemplar substrates include: concrete, pre-existing brick-work, stone-work or other natural material, pre-con and the like.

Without wishing to be bound to any particular theory it is proposed herein that oxides present in powdered material(s) will dissipate throughout, or become dispersed within the resinous mixture to provide a coating composition, for application to a surface for application, whether coating, repair or restoration, with a unique ability to deliver a strong and robust surface with the further desirable, and hitherto unachievable property of colour-matching to the original material.

A further advantage of the use of the resinous compositions additionally comprising recycled powdered materials in repair or restoration projects as detailed hereinbefore, is that inclusion of the original material in powdered form into said resinous compositions means that these materials may be re-moulded to form architectural features such as for example lintels, cornicing and the like, or applied as renders, plasters or coatings.

Recycled material in powdered form suitable for use herein may be prepared in situ as follows. In a repair and/or restoration project on a block-work stone building for example, the particular area(s) of stone work requiring attention are identified, and then the masonry material in each block is carefully cut out and the materials collected and individually stored.

The value of individual collection and storage is the maintenance of the integrity of the repaired stone work with that of the original building. Such collection and storage techniques are particularly useful in large projects where many areas are to be repaired or even in small projects where the repair is likely to be interrupted. To ensure this integrity is retained, the individual blocks may be suitably numbered to avoid cross-contamination of the collected, stored materials. Each of the stored materials is then pulverized to a powder, for example via crushing by hand with a hammer, followed by sieving through a fine sieve, similar in size to a flour sieve. Any alternative powder preparation technique(s) may be used without departing from the spirit of the present invention.

As detailed hereinbefore, the resinous compositions according to the invention may be formulated to provide a range of products suitable for external and internal use.

According to one aspect the present invention provides aqueous resinous pre-mix composition which is suitable for combination with powdered material and optionally water to provide a range of external or internal coatings, renders or mouldable materials, as well as being suitable for use as a direct base-coat! binding product.

Thus the present invention additionally provides an aqueous resinous composition for use as a base mix to which one or more powdered materials and optionally additional material may be added according to the desire of the user to provide different internal or external coatings.

As described a unique advantage provided by the resinous compositions of the invention, is that they can be used in combination with powdered materials, particularly recycled masonry and/or ceramic materials. The applicant has developed a range of unique resinous mixtures suitable for use in the preparation of internal and external products, and has additionally developed processes for the combination of said mixtures with various powdered materials, particularly powdered recycled materials, and their application to different external and/or internal surfaces for a range of purposes, including coatings, renders, moulding materials and liquid-stone products.

A particular advantage of the external coating compositions herein, particularly where related to restoration or repairs of historical buildings, is that they avoid the use of expensive and time-consuming analyses of the material to be repaired, e.g. stone-work, and manufacture of synthetic composite materials for use to provide a coating designed to be complementary with the original material. However, such synthetic coatings cannot weather consistently with the original material, are commonly not sufficiently complementary to effect suitable repairs and are thereby non-optimal for use in sympathetic restoration or repair work. The present compositions provide a unique method for incorporation of recycled materials into a novel resinous composition to deliver a coating composition which has complementary physical characteristics to that of the original materials, such as for example reflective properties and surface properties which are currently not possible using synthetic coatings, as well as delivering an optimal colour.

Where renders are prepared sand is additionally included at levels of between about 40% to about 65%, from about 45% to about 60%, from about 50% to about 55%, about 55% by weight of final render to be applied. Any suitable sand may be used.

Advantages of the external rendering compositions herein, are that they are mouldable. The compositions can be poured into moulding for any suitable feature, including architectural features, and once dried the moulds can be broken out to reveal perfect shapes ready to fix to the building. It can be moulded and used as indented block work on external walls for all masonry materials. Once the render has dried it can be chiselled and sanded like stone. Whilst under normal circumstances this can be an expensive and time consuming operation, use of the unique external rendering compositions herein are especially suited for customised moulding to provide final 3D features which include the fine chiselled marks which may vary from region to region, and are indicative of a hand-chiselled feature. The rendering compositions herein can be applied by trowel like any other external rendering process.

The external rendering compositions can also be used to point joints. By raking out the pointing material and crushing and sieving it can be added to the aqueous pre-mix to the exact same ratio as the render and then pointed in a similar way.

Matching external render is currently done exactly the same way as described hereinbefore for coatings, with a time consuming process involving sample taking and analysis or use of swatch cards in order to select a premixed bag of coloured render. Use of the rendering compositions herein avoids this process altogether and provides rendered surfaced having common physical properties to the original material in terms of reflective properties and surface texture, as well as providing an optimal colour match.

A particular advantage of the external rendering resinous compositions herein are their unique strength and weathering integrity versus current commercial renders. The applicant has found that the rendering compositions are uniquely able to absorb moisture in a manner consistent with natural materials, particularly those using sandstone within the powdered material(s), and furthermore, have been demonstrated to retain their strength when dry. Without wishing to be bound by any particular theory it is proposed herein that this may be related to the enhanced porosity provided by the present compositions versus the non-porous traditional synthetic rendering compositions of the art, particularly those for repair or restoration utility.

Thus the present invention additionally provides resinous compositions as defined herein and optionally additionally comprising recycled materials for external and/or internal use as surface coating compositions.

The Applicant has found that a weight ratio of about 1: 3 of aqueous resinous pre-mix to powder is particularly preferred for the provisions of strong mixes for the preparation of resinous coating compositions, or resinous rendering compositions as detailed herein.

According to a further aspect the present invention provides processes for the manufacture of the resinous compositions as detailed hereinbefore, and additionally processes for their combination with recycled materials to provide resinous surface coating compositions.

Thus the present invention additionally provides a process for the preparation of the resinous coating, rendering or moulding compositions according to the invention wherein said process comprises the steps of: (i) mixing together styrene acrylic copolymer; lime putty; and/or non-ionic urethane; and/or kaolin; and optionally salt; and water to form an aqueous premix; (ii) combining said aqueous premix with powdered material, and optionally additional water, or sand to provide a resinous composition suitable for use as an external or internal coating, external render, or moulding material; and (ih) optionally drying said coating, render or moulding material.

According to a yet further aspect the present invention provides processes for the preparation of external or internal coatings, renders or stone set products substantially as detailed in the Examples herein.

The relative order of addition of mateiials in step (i) may be changed provided the final consistency of the product is maintained.

A yet further aspect of the present invention provides processes for the coating of internal and/or external surfaces with coating or rendering compositions containing powdered material(s) as defined hereinbefore. Thus according to a further aspect the present invention provides said coating processes substantially as described in the

Examples herein.

As detailed herein before, certain aqueous resinous pre-mix compositions or resinous rendering or stone set compositions containing powdered material(s) herein may be advantageously provided as dried, ready-to-use products. For the avoidance of doubt, the relative weights of the components within said dried products are provided on the basis of their pre-drying levels. Any suitable drying method may be used to dry the pre-mixes or coating or stone set compositions comprising powdered materials. Further processing of the dried pre-mixes or compositions, such as granulation, grinding or other suitable treatment to provide easier to use material, or freely flowing product can be employed.

Thus the present invention additionally provides a resinous rendering composition as defined herein, wherein said composition is provided in dried form.

Thus the present invention additionally provides a resinous stone set composition as defined herein, wherein said composition is provided in dried form.

According to a yet further aspect the present invention provides a dried pre-mix wherein the acrylic resin therein was present in dried form as opposed to in dispersed form.

Experimental Results The following non-limiting examples provided in the Experimental results hereinafter are representative of the resinous mixtures, their combination with powdered materials and processes for their preparation.

Example 1: External Coatinci Composition so The formulation of Example 1 is suitable for use an external coating, in other words the final coating on a structure, building, façade or part thereof which is open to the elements. Such external coatings may be applied either to a suitably prepared surface, such as for example a surface rendered with NH lime based render, or to a surface which has been pre-treated with a suitable bonding coat (see Example 1A).

Table 1 shows the composition of the aqueous pre-mix for! and final composition of, external coating composition 1.

Table 1

Component Aqueous Pre-mix % Aqueous Coating % Revacryl 245 500g 50 125g 11.4 Water bOg 10 25g 2.3 Acrysol RM825 30g 3 7.5g 0.7 NaCI (Salt) 20g 2 5g 0.4 White kaolin 300g 30 75g 6.8 White non-hydraulic lime 50g 5 12.5g 1.1 Powder --750g 68.2 Waterforcoating --100m1 9.1 Total 1Kg 100 1.1Kg 100 The formulation was prepared by mixing together water and Revacryl 245 at room temperature with stirring (stirring may be by hand or via machine, such as for example a paint mixer, and is gentle to begin with and then as the mix becomes thicker more vigorous), followed by addition of salt, Kaolin and white NH lime with continued stirring. Acrysol RM 825 was then added with further stirring until the mixture achieved a "paint-like" consistency, at which point stirring was discontinued, and the mixture left to settle, for up to about one hour, thereby providing 1Kg of a resinous composition which is ready-to-mix with powdered material for the provision of an external coating.

1.1Kg of external coating was prepared via addition of up to about lOOmI of cold, clean water to 750g of sieved recycled buff sandstone powder with mixing, providing a slurry, followed by addition of 250m1 of the mixed resinous composition with further stirring to provide an external coating composition having a consistency which is thicker than water yet thinner than masonry-paint.

Whilst the skilled formulator will be familiar with, and can readily recognise compositions having a consistency like that of a thicker than normal paint, such as masonry paint, this can be quantified using measurements of the viscosity and/or specific gravity, wherein formulations having a specific gravity between about 1.0 to about 2.0, between about 1.1 and about 1.5, between about 1.2 and about 1.4, and/or a viscosity at about 23C of between about 2 to about 8, between about 3 to about 7, between about 4 to about 6.5 cSt. Any suitable viscometer may be used, to provide measurements in Zahn cups, or Krebs unity (KU) with conversion to kinematic viscosities in centistokes (Cst), also known as stokes (St), or m2/s via common conversion equations wherein 1 St = 104m2.s4 and 1 cSt = 106m2.s1.

The external coating composition of Example 1 can be applied directly to either a rendered or coated/pre-treated surface as desired. Such application can be affected using a brush, or roller, or other such application means. The number of coats required for any given surface, will particularly in the context of a repair or restoration project, largely depend upon the surrounding original material, the desired effect to be achieved, or the thickness of coating applied. However, in general, using a brush or roller and applying as a paint-like product, two coats are recommended to ensure consistent coverage. However additional third or further coats may be applied, according to needs of the user, to provide a more precise finish. As with all external masonry coatings, an effective drying time of between 2 and about 4 hours should be allowed between each coat. Clearly this will be dependent on the prevailing weather conditions in the climate where the work is being carried out.

Once dried, the coated surface can be lightly sanded. To ensure that the surface has fully dried, up to 2, or 3 days, again dependent on prevailing weather conditions, would be recommended prior to sanding.

In this example powdered masonry material was used, however any suitable powdered material as described hereinbefore may be incorporated into either the above resinous mixture to provide an external coating composition.

In the event that a particular sample of powdered material provides a coating composition which at first glance appears darker than the surface to be coated, repaired, restored, then dilution with white NH lime, at between about 1% to about 5% of the coating composition will dilute the strong rich unseen oxides and the colour that is required will come through.

Example 1A: External Bonding Composition Table 1A shows the composition of an external bonding composition which can be used to pre-coat surfaces prior to the application of external coating compositions such as those illustrated in Example 1. The purpose of using such an external bonding coat is primarily to provide a suitable surface for bonding an exterior coating such as that provided by Examples 1 or 4 thereto. Examples of circumstance where such bonding coats may be advantageously applied are in hard-to-coat surfaces, surfaces rendered with cement or cement containing materials, such as Portland cement or the like.

Table 1A

Component Aqueous Bonding Coat % Revacryl 245 400g 40 Water 200g 20 Acrysol RM825 30g 3 NaCI (Salt) 20g 2 White non-hydraulic lime 350g 35 Total 1Kg 100 The formulation was prepared by mixing the water and lime vigorously, followed by addition of salt with continuous mixing. The Revacryl 245 and then the Acrysol Rm825 were added with continued mixing until all the ingredients are emulsified. Once the mixture started to thicken it was left to settle prior to application to the surface. For application to a surface a mix having a consistency like thick masonry paint, is desired.

As non-hydraulic lime is a natural substance, different batches are therefore prone to different levels of consistency, which can lead to mixtures being too thick. Should this occur, then small amounts of water (5m1) and equal parts of Revacryl 245 can be added to dilute the mix to the desired consistency. When this is achieved the coating is ready to use within 1 hour of mixing.

The coating can be applied to the surface by brush or by roller and the drying time is dependent on weather conditions but the first coat should be dry within about two to four hours, and if required/desired a second coat can be applied Example 2: External Render Composition The external render of composition 2 may be used as an alternative to the bonding and/or coating methods as detailed hereinbefore and as illustrated by compositions 1 and 1A.

The formulation of Example 2 is suitable for use an external render, in other words an external surface on a structure, building, façade or part thereof which is open to the elements. Such external renders may be applied to a suitably prepared surface, such as for example a rendered surface which has been pre-treated with a suitable bonding coat.

Table 2 shows the composition of the aqueous pre-mix for, and final composition of external render composition 2.

Table 2

Component Aqueous Pie-mix % Aqueous Render % Revacryl 245 800g 80% 160g 13.3% Water 150g 15% 30g 2.5% NaCI (Salt) 20g 2% 4g 0.3% White non-hydraulic lime 30g 3% 7.5g 0.6% Powder --666g 55.5% White Sand --333g 27.8% Total 1Kg 100 1.2Kg 100 The aqueous pie-mix for external render of composition 2 was prepared via vigorous mixing! either by hand or via machine, together of Revacryl 245, water, salt and white NH lime at room temperature for about 10 minutes. Once the mixture had attained a masonry paint-like consistency it was left to settle piioi to use in situ. Alternatively, should the iender pie-mix be required at a later-stage, said pre-mix could be dried and powdered for such later-use if desired.

To 1Kg of powdered, sieved recycled buff sandstone masonry matenal was added 500g of white sand with thorough mixing, to ensure the sand was well-mixed throughout the dust, to provide a 1.5Kg batch. To 1Kg of this batch, 200g of the aqueous pie-mix was added with mixing, either by hand or via machine as detailed hereinbefore. Minor variations between powder size for different powdered materials may require the addition of further small amounts of either the remaining batch powder/sand mixture or small amounts of the aqueous render pre-mix until the desired consistency is achieved.

Should the render be required for a later-stage, the product can be dried and powdered for later-use.

The Applicant has found that a weight ratio of about 1: 3 of aqueous pre-mix to powder is particularly preferred for the provisions of strong mixes for the preparation of coatings or renders, and the like.

Example 3: Liquid Stone Composition The liquid stone composition of Example 3 may be used either internally or externally, and is essentially a liquid stone which can be made from a wide range of powdered materials, including recycled materials from slate to marble and from brick to granite. Where recycled materials are utilised, the waste masonry material can be pulverised into a fine powder pnor to addition to the aqueous pre-mix. The final compositions can then be painted on to almost any surface and when sanded has desirable strength and robustness and appeai to be stone to the naked eye.

Table 3

Component Aqueous Pre-mix % Liquid Stone % Revacryl 245 500g 50% 500g 35.7% Water 200g 20% 200g 14.3% Acrysol RM 825 25g 2.5% 25g 1.8% Kaolin 275g 27.5% 275g 19.6% Powder --400g 28.6% Total 1Kg 100 1.4Kg 100 To prepare the aqueous pie-mix, the kaolin is added to the water with stirring (as detailed hereinbefore), followed by addition of the Revacryl 245, and then Acrysol with continued stirring. Whilst the mixture could be used immediately, it was left to settle for up to one hour.

To the 1Kg of aqueous pre-mix was added 400g of powdered white marble with mixing. The mixture was left to settle for one hour, then mixed once more and was then ready to use.

The liquid stone composition can be applied to any suitable surfaces by brush or roller and once set can be re-applied as many times as is desired by the user. For example, if heavy sanding or polishing of the final surface in anticipated, three or four coats can be applied, and two coats for light sanding or polishing purposes.

Drying times may vary according to the particular powdered material used, and/or the environmental conditions. Ideal conditions for drying are between temperatures of about 10°C to about 20°C. Sanding will bring out the stone finish and normal sand paper will bring the desired effect.

Example 3: Stone Set Composition The stone set composition of Example 4 may be used either internally or externally, and is similar to the render product of Example 2, but with the additional advantage that it can be moulded. Surprisingly it can be moulded like clay, but sets like stone, and can be sanded and/or polished as desired. The stone set products can be made from a wide range of powdered materials, including recycled materials from slate to marble and from brick to granite. Where recycled materials are utilised, the waste masonry material can be pulverised into a fine powder prior to addition to the aqueous pre-niix.

Table 4

Component Aqueous Pie-mix % Liquid Stone % Revacryl 245 700g 77% 280g 20% Water bOg 10% 40g 2.91% Kaolin 200g 20% 80g 5.7% Powder --l000g 71.4% Total 1Kg 100 1.4Kg 100 The aqueous pie-mix is prepared by mixing the three matenals together and then leaving for up to about 1 hour to settle. 1 kg of white marble dust was then added to 400g of the stone-set pre-mix, followed by mixing together to provide a ready-to-use product of a consistency resembling that of plaster as routinely applied by plasterers using a trowel and hawk. The composition was plastered onto gyproc and applied to a thickness of 6mm and then allowed to dry. Normally this would be determined by the temperature of the room but after two to three days as with most plasters the wall should be ready for either sanding, polishing, or cutting, for example to provide a tiled effect, as desired. Alternatively the product can be moulded to any suitable shape required by the particular project, for example moulding to provide architectural features or parts thereof, particularly in restoration or repair projects.

On very difficult to apply surfaces a bonding pre-coat similar to that detailed in Example 1A could be used.

The stone set process can also be used to recycle old plaster, by use of powdered plaster.

Whilst the aqueous pre-mix was mixed with powdered material directly in the above example, said pie-mix may be dried and powdered to provide a pie-mix in a convenient form for use with any suitable powdered materials, such as for example for a variety of smaller repairs over the course of time on the same or alternative projects.

Alternatively, should the stone set product be required for use at a later-stage, the product can be dried and powdered for such convenient later-use.

Whilst the illustrated examples used recycled buff sandstone or white marble as the powdered material, similar results have been achieved to prepare external and internal products as detailed hereinbefore using alternative powders including buff sandstone, red sandstone, red brick, biown buck, white maible, green slate, Scottish slate, buff pie-con block, and mixtures thereof.

Claims

Claims 1. A resinous composition for use an aqueous base for the preparation of materials for use in external or internal building or construction projects comprising: (a) acrylic resin in dispersed form; (b) lime putty; and/or (c) non-ionic urethane; and/or (d) kaolin; and optionally (e) salt; and (f) water.
2. A composition according to claim 1 wherein said acrylic resin is present at between about 45%% to about 80% by weight of composition.
3. A composition according to claim 1 or 2 wherein said acrylic resin in dispersed form is a surfactant stabilised, styrene / acrylic ester copolymer dispersion, preferably Revacryl 245.
4. A composition according to any of the preceding claims wherein said urethane is present at between about between about 2% to about 5% by weight of composition
5. A composition according to any of the preceding claims wherein the non-ionic urethane is Acrysol RM825.
6. A composition according to any of the preceding claims wherein said lime putty is present at between about 2% to about 8% by weight of composition.
7. A composition according to any of the preceding claims wherein said salt is present at between about 0.1% to about 3% by weight.
8. A composition according to any of the preceding claims wherein said kaolin is present at between about 14% to about 40% by weight.
9. A resinous composition for use as an external coating comprising acrylic resin in dispersed form; lime putty; non-ionic urethane; kaolin; salt; one or more powdered material(s); and water.
10. A resinous composition for use as an external rendering composition comprising acrylic resin in dispersed form; lime putty; salt; one or more powdered material(s); sand; and water.
11. A resinous composition for use as an internal coating composition comprising acrylic resin in dispersed form; non-ionic urethane; kaolin; one or more powdered material(s); and water.
12. A resinous composition for use as an internal coating composition comprising acrylic resin in dispersed form; kaolin; one or more powdered materials; and water.
13. A resinous composition according to any of claims 10 to 12 wherein said one or more powdered materials are independently selected from masonry or ceramic materials in powdered form and wherein said powdered material(s) are present at a total level of between 25% to about 75% by weight of composition.
14. A resinous composition according to any of claims 10 to 13 wherein said acrylic resin is present at between about 10% to about 40% by weight of composition.
15.A resinous composition according to any of claims 10, 11 or 13 wherein said urethane is present at between about 0.4% to about 5% by weight of composition.