GB2372253A

GB2372253A - Render comprising polymer

Info

Publication number: GB2372253A
Application number: GB0103956A
Authority: GB
Inventors: Malcolm Kitching
Original assignee: RENDIT Ltd
Current assignee: RENDIT Ltd
Priority date: 2001-02-17
Filing date: 2001-02-17
Publication date: 2002-08-21
Anticipated expiration: 2021-02-17
Also published as: GB0103956D0; GB2372253B

Abstract

A render comprising a polymer, metal carbonate, a metal silicate, an aggregate filler, a metal polyphosphate and, optionally, water. The polymer may be an acrylic polymer. The carbonate, optionally calcium carbonate, may comprise particles of different sizes. The metal silicate may be magnesium-, potassium- or aluminium silicate. The metal polyphosphate may be sodium polyphosphate. The render may also comprise a mineral spirit. Also included may be a colour substance such as iron oxide. Also claimed is said render wherein the concentration of water is in the range 1-75% (w/w) of the total weight of the render. Further claimed is a method of repairing a damaged area on the surface of a wall and/or building, the method comprising the steps of (a) preparing said render and, (b) applying the render to the damaged area.

Description

A RENDER

The present invention relates to renders and particularly, although not exclusively, to methods of repairing renders.

The components of typical renders used for coating the surface of walls and buildings include an aggregate (graded sand), lime (calcium hydroxide), cement, an acrylic polymer, chemical additives for shrinkage and set control, and powdered iron oxide pigments, for colouration if required. The proportions of the components within such cement renders vary, depending on the finished effect required, application method to be utilized and background surface to be covered.

The cement render may be either plain or coloured and is typically blended in a factory, with all the components being dry which are then bagged, ready for subsequent mixing with water, at the time of application, on site.

Unfortunately, such cement renders are prone to damage and/or defects. These defects are typically cracks, fissures, water staining, efflorescence (ie contamination by surface salt), impact damage and colour variation through malapplication of the surface render.

Repairing such defects in cement renders with the identical cement render is rarely aesthetically successful and always difficult. This is due to the initial cement render application forming a surface skin of fines, polymers etc due to the trowelling and application procedure. Unfortunately, the trowelling action cannot be exactly duplicated when applied to small or thin areas and

the differences in texture of the surface skin create apparent colour variation and highlight the defect and its subsequent repair.

Repairing a small individual area affected by surface staining, efflorescence, etc using cement renders is not possible due to the minimum thickness necessary for the application of the materials, and a complete elevation or section has to be reapplied.

Repairing fissures using cement based mortars is rarely successful because further minor movement inevitably recreates the fissure.

It is one of the aims of the embodiments of the present invention to address the above problems and to provide a render and also a method for quickly and simply repairing defects in surface concrete renders.

According to a first aspect of the present invention, there is provided a render comprising a polymer, a metal carbonate, a metal silicate, an aggregate filler, a metal polyphosphate and, optionally, water.

Preferably, the polymer is an acrylic polymer. The polymer may be a co-polymer such as a styrene acrylic co-polymer.

The polymer may be in the form of an aqueous dispersion.

Preferably, the polymer comprises a suitable Cl-C6 alkyl Ci-Cg alkacrylate or Ci-Cg alkacrylate, more preferably, a butylacrylate and, most preferably, a butylacrylatestyrene co-polymer aqueous dispersion.

Preferably, the concentration of the polymer is in the range of 0. 5-30% (w/w), more preferably, 5-20% (w/w) and, most preferably, 10-15% (w/w) of the total weight of the render.

The metal carbonate may be a suitable alkali or alkaline earth metal carbonate. Preferably, the metal carbonate is calcium carbonate.

The calcium carbonate may be provided in different particle sizes, for example, in the form of calcite 40 (ie fine particle size) and/or calcite 130 (ie medium particle size).

Preferably, the concentration of calcite 40 is in the range of 20-60% (w/w), more preferably, 35-45% (w/w) and, most preferably, 37-42% (w/w) of the total weight of the render.

Preferably, the particle size of calcite 40 is in the range of 0.3mm-2. 2mm, more preferably, 0.7mm-1. 8mm, and, most preferably, l. Omm-1. 5mm.

Preferably, the concentration of calcite 130 is in the range of 10-40% (w/w), more preferably, 15-35% (w/w) and, most preferably, 22-29% (w/w) of the total weight of the render.

Preferably, the particle size of calcite 130 is in the range of 0. 8mm-2.7mm, more preferably, 1.2mm-2. 3mm, and, most preferably, 1.5mm-2. 0mm.

The metal silicate may comprise a suitable alkali or alkaline earth metal silicate. Preferably, the metal silicate comprises magnesium silicate. Preferably, the metal silicate comprises potassium silicate. The metal silicate may comprise a suitable group 3 metal silicate. Preferably, the metal silicate comprises aluminium silicate. Preferably, the metal silicate is a mixed metal silicate comprising magnesium, aluminium and potassium.

Preferably, the concentration of the metal silicate is in the range of 0.5-15% (w/w), more preferably, 3.0-10% (w/w) and, most preferably, 4. 0-8. 0% (w/w) of the total weight of the render.

Preferably, the concentration of the aggregate filler is in the range of 0.5-15% (w/w), more preferably, 1-10% (w/w) and, most preferably, 3.0-6. 0% (w/w) of the total weight of the render. Preferably, the particulate size of the aggregate filler is in the range of O. lmm-3mm, more preferably, O. 5mm-2mm and, most preferably, 1. Omm-1. 5mm.

The aggregate filler may be sand.

The metal polyphosphate may be a suitable alkali or alkaline earth metal polyphosphate. Preferably, the metal polyphosphate is sodium polyphosphate. The metal polyphosphate may be sodium hexametaphosphate.

Preferably, the concentration of the metal polyphosphate is in the range of 0.1-10% (w/w), more preferably, 0.55. 0% (w/w) and, most preferably, 1.5-3% (w/w) of the total weight of the render.

Preferably, the render is a basic solution and, preferably, an ammoniacal solution. Preferably, the concentration of the basic solution is in the range of 0.1-10% (w/w), more preferably, 0.5-5. 0% (w/w) and, most preferably, 0.75-1. 0% (w/w) of the total weight of the render.

Preferably, the render comprises a mineral spirit. Preferably, the concentration of the mineral spirit is in the range of 0.1-10% (w/w), more preferably, 0.5-5. 0% (w/w) and, most preferably, 0.75-1. 25% (w/w) of the total weight of the render.

Preferably, the render comprises butyldiglycol.

Preferably, the concentration of the butyldiglycol is in the range of 0.1-10% (w/w), more preferably, 0.5-5. 0% (w/w) and, most preferably, 0.75-1. 25% (w/w) of the total weight of the render.

Preferably, the render comprises titanium dioxide rutile.

Preferably, the concentration of titanium dioxide rutile is in the range of 0.5-10% (w/w), more preferably, 1.05.0% (w/w) and, most preferably, 2.0-3. 5% (w/w) of the total weight of the render.

Preferably, the render comprises a colour substance.

Preferably, the colour substance comprises a metal oxide, preferably, iron oxide. Preferably, the concentration of the colour substance is in the range of 0.05-1. 0% (w/w), more preferably, 0.075-0. 5% (w/w) and, most preferably, 0.1-0. 3% (w/w) of the total weight of the render.

Preferably, the render is a viscous solution.

Advantageously, the render may be applied to cracks, fissures and areas of impact damage on the surface of walls and buildings etc. Advantageously, and preferably, the render is substantially viscous and may be'squeezed' into said cracks and fissures.

Preferably, the render comprises water. Preferably, the concentration of water is in the range of 0.5-10% (w/w), more preferably, 1.0-5. 0% (w/w), most preferably, 2.0-3. 0% (w/w) of the total weight of the render.

According to a second aspect of the present invention, there is provided a render comprising a polymer, a metal carbonate, a metal silicate, an aggregate filler, a metal polyphosphate and water wherein the concentration of water is in the range 1-75% (w/w) of the total weight of the render.

Preferably, the concentration of water is in the range of 5-50% (w/w), more preferably, 10-30% (w/w) and, most preferably, 13-17% (w/w) of the total weight of the render, prior to the addition of water.

Advantageously, the render of the second aspect exhibits a less viscous consistency than the render of the first aspect and may be applied, by painting with a brush or roller, to areas of water staining, efflorescence (ie contamination by surface salt), and colour variation on the surface of walls and buildings etc.

According to a third aspect of the present invention there is provided a method of repairing a damaged area on the surface of a wall and/or building, the method comprising the steps of : (a) preparing the render of either of the first and second aspects; and (b) applying the render to the damaged area.

Preferably, the damaged area comprises a cement render, which, preferably, comprises an acrylic polymer. Preferably, the polymer of the render is substantially chemically equivalent to the polymer of the cement render.

Preferably, the polymer of the render is the same as the polymer of the cement render.

For example, if the polymer of the cement render comprises acrylic co-polymer, then the polymer in the render comprises acrylic co-polymer.

Advantageously, the addition of the same polymer to the render of the same polymer as utilised in the cement render enables the alteration of the finished appearance of the repaired area from an open matt texture to that of a smoother, glossy coat. Advantageously, this reproduces the variation in surface appearance created by differing levels of polymer, (ie a generally higher concentration of polymer results in a more shiny appearance). Preferably, for optimum repair effects, the polymer used in the render matches that as used in the original cement render so that closer matching of texture and colour may be achieved.

Preferably, the concentration of the polymer in the render is substantially equal to the concentration of the polymer in the cement render.

When using the render according to the first aspect, the method of repairing the damaged area on the surface of a wall and/or building further comprises the steps of : (i) lightly tapping the applied render to reproduce the textured surface of the cement render; (ii) removing excess render; and (iii) allowing the render to set.

Any or all steps of the method may be repeated if necessary.

When using the render according to the second aspect, use of a foam roller is preferred. Advantageously, use of the foam roller avoids brush marks.

All of the features described herein may be combined with any of the above aspects, in any combination.

Example The materials utilized in the render repair system consist of a base repair render mixture, and colour substance which is then applied to the damaged areas of the surface cement render.

The components of the base repair render are as follows :

Component Concentration (Parts by weight) A Polymer (Styrene acrylic co-polymer 131.0 Resin Emulsion) B Sodium polyphosphate (10%) 19.5 C Ammoniacal solution 8.3 D Mineral spirit 10. 0 E Butyldiglycol 10.0 F Titanium dioxide rutile 28.0 G Mg-K-Al silicate (medium) 66.0 H Calcite 40 (fine) 393.0 I Calcite 130 (medium) 256.0 J Aggregate (1.0-1. 5mm) 43.0 K Water 25.0 It should be noted that, with the exception of components H-J above which are in powder form, the above components are all liquid. Furthermore, the above repair render mixture has no common ingredients with the surface cement render particularly the cement and lime components, except for the aggregate (component) which consists of sand and the polymer (component A). The aggregate component in the repair render has a finer nature than the cement render which the repair render is used to repair. The polymer is a butylacrylate-styrene co-polymer aqueous dispersion.

The rheology created by thorough power mixing the above base repair render mixture enables the encapsulation and homogenization of the powder chemical elements (ie components H-J).

The addition to the base repair render of the same polymer (styrene acrylic co-polymer resin) utilised in the cement render enables the alteration of the finished appearance of the base render repair materials from an open matt texture to that of a smoother, glossy coat. This reproduces the variation in surface appearance created by differing levels of polymer, (ie generally, a higher concentration of polymer results in a more shiny appearance) utilized in the cement render, to create products for different purposes. For optimum effect, it is preferable that the polymer used in the base repair render matches that as used in the original surface cement render so that closer matching of texture and colour may be achieved.

It should be appreciated that minor variations within the formulation of the materials developed for the cement render repair method serve to copy the colour variation created by differences in proportions of the ingredients within the cement render and application methods utilised.

The addition of extra polymer to the base repair render, depending upon the level of polymer additive in the cement render varies from between 1-5% (w/w) polymer weight to the previous mixture weight.

A powder black iron oxide pigment is added to the base repair render at a weight of between 0.1-0. 3% (w/w) of the total weight of the render. This may be varied in accordance with the cement: aggregate ratio in the cement render. The iron oxide pigment produces a grey material that can be utilized to match the finished surface of the non-coloured cement render, for example, where standard

ordinary portland cement has been utilized in the manufacture of the surface cement render. The addition of the identical powder iron oxide pigments utilized in the production of the coloured base repair render, in the same or similar % ratios as in the cement render produces a material that can match the finished surface of the coloured cement render.

The produced base repair render, hereafter called'infill' (TM), can then be utilized for the infill of fissures, cracks and other minor defects, in cement renders.

The addition of a further 15% (w/w) water to the components of the base repair render produces a material which has a runnier consistency than that of'infill' (TM) but which is still retentive of the powder dispersions, enabling its application to a damaged cement render by roller or brush. The produced material, hereafter called 'Colorseal' (TM), can be utilized for the obliteration of efflorescence and surface colour stains on cement renders.

The Application Method :1) Infill (TM) a) The base repair render is prepared (ie, components A-K are mixed together) and then filled into a flexible bottle container which incorporates a dispensing spout. b) The spout of the tube is cut to allow a suitable ribbon of material to be discharged into a crack or fissure in a cement render.

c) The discharged material is flattened to the surface level with an 8-10mm wide wood or plastic flat edge. The applied materials are then lightly tapped with a small paintbrush to reproduce the textured surface of the surface render. d) Any excess materials are wiped away with a damp cloth. e) The infill is allowed to set (30 minutes in summer, 3-4 hours in winter) and the process may be repeated, in the event of any sagging of the infill in the fissure in the cement render.

2) Colorseal (TM) a) The Colorseal (TM) base repair render is prepared as for the infill (TM), however, additional water 15% (w/w) of the total weight of the render, prior to the addition of water is added to produce a far runnier consistency. The Colorseal (TM) is then filled into suitable containers, such as 2.5 litre lidded pails. b) The Colorseal (TM) is then applied to the damaged cement render either by brush, roller or spray. c) The use of a foam roller enables the speedy application of the base repair render and the blending in of repaired plain or scraped finished renders. The roller is emptied onto adjacent areas after the treated areas have been obliterated. The use of a foam roller avoids brush marks. d) A small quantity of water is added to the roller tray. The roller is loaded from the container and then flattened on the tray, with small quantities of water added from the tray, to achieve optimum

workability. Additional quantities of water are not detrimental to the product except that obliteration qualities are marginally reduced. e) A further second application, following initial set may be required to cover any areas previously omitted.

Advantages of the render repair system reside in the fact that the colour of materials used in the cement render repair method are not affected by differences in the application technique and aesthetically acceptable repair is therefore more easily achieved. Furthermore, the use of Colorseal (TM) enables affected areas solely to be overcoated. The application technique enables the blending-in of treated areas to non-treated areas.

The cement render repair method has a high degree of flexibility, which enables further minor movement to occur, without detriment to the repair.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s). The invention extend to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A render comprising a polymer, a metal carbonate, a metal silicate, an aggregate filler, a metal polyphosphate and, optionally, water.

2. A render according to claim 1, wherein the polymer is an acrylic polymer.

3. A render according to either of claims 1 or 2, wherein the concentration of the polymer is in the range of 0.530% (w/w), of the total weight of the render.

4. A render according to any preceding claim, wherein the metal carbonate is a suitable alkali or alkaline earth metal carbonate.

5. A render according to any preceding claim, wherein the metal carbonate is calcium carbonate.

6. A render according to claim 5, wherein the calcium carbonate is provided in different particle sizes, for example, in the form of calcite 40 (i. e. fine particle size) and/or calcite 130 (i. e. medium particle size).

7. A render according to claim 6, wherein the concentration of calcite 40 is in the range of 20-60% (w/w) of the total weight of the render.

8. A render according to either of claims 6 or 7, wherein the particle size of calcite 40 is in the range of 0.3mm2.2mm.

9. A render according to any of claims 6 to 8, wherein the concentration of calcite 130 is in the range of 10-40% (w/w) of the total weight of the render.

10. A render according to any of claims 6 to 9, wherein the particle size of calcite 130 is in the range of 0.8mm2.7mm.

11. A render according to any preceding claim, wherein the metal silicate comprises a suitable alkali or alkaline earth metal silicate.

12. A render according to any preceding claim, wherein the metal silicate comprises magnesium silicate.

13. A render according to any preceding claim, wherein the metal silicate comprises potassium silicate.

14. A render according to any preceding claim, wherein the metal silicate comprises aluminium silicate.

15. A render according to any preceding claim, wherein the concentration of the metal silicate is in the range of 0.5-15% (w/w) of the total weight of the render.

16. A render according to any preceding claim, wherein the concentration of the aggregate filler is in the range of 0.5-15% (w/w) of the total weight of the render.

17. A render according to any preceding claim, wherein the particulate size of the aggregate filler is in the range of 0. lmm-3mm.

18. A render according to any preceding claim, wherein the metal polyphosphate is a suitable alkali or alkaline earth metal polyphosphate.

19. A render according to any preceding claim, wherein the metal polyphosphate is sodium polyphosphate.

20. A render according to any preceding claim, wherein the concentration of the metal polyphosphate is in the range of 0.1-10% (w/w) of the total weight of the render.

21. A render according to any preceding claim, wherein the render is a basic solution.

22. A render according to claim 21, wherein the concentration of the basic solution is in the range of 0.1-10% (w/w) of the total weight of the render.

23. A render according to any preceding claim, wherein the render comprises a mineral spirit.

24. A render according to claim 23, wherein the concentration of the mineral spirit is in the range of 0.1-10% (w/w) of the total weight of the render.

25. A render according to any preceding claim, wherein the render comprises butyldiglycol.

26. A render according to claim 25, wherein the concentration of the butyldiglycol is in the range of 0.110% (w/w) of the total weight of the render.

27. A render according to any preceding claim, wherein the render comprises titanium dioxide rutile.

28. A render according to claim 27, wherein the concentration of titanium dioxide rutile is in the range of 0.5-10% (w/w) of the total weight of the render.

29. A render according to any preceding claim, wherein the render comprises a colour substance.

30. A render according to claim 29, wherein the colour substance comprises a metal oxide.

31. A render according to either claim 29 or 30, wherein the colour substances comprises iron oxide.

32. A render according to any of claims 29 to 31, wherein the concentration of the colour substance is in the range of 0.05-1. 0% (w/w) of the total weight of the render.

33. A render according to any preceding claim, wherein the render is a viscous solution.

34. A render according to any preceding claim, wherein the render comprises water.

35. A render according to claim 34, wherein the concentration of water is in the range of 0.5-10% (w/w) of the total weight of the render.

36. A render comprising a polymer, a metal carbonate, a metal silicate, an aggregate filler, a metal polyphosphate

and water, wherein the concentration of water is in the range 1-75% (w/w) of the total weight of the render.

37. A method of repairing a damaged area on the surface of a wall and/or building, the method comprising the steps of : (a) preparing the render according to any of claims 1 to 36; and (b) applying the said render to the damaged area.

38. A render as substantially herein described with reference to, and as illustrated by, the accompanying example.

39. A method of repairing a damaged surface of a wall and/or building as substantially herein described with reference to, and as illustrated by, the accompanying example.