GB2497558A - Tile adhesive - Google Patents

Abstract

The invention provides an adhesive composition suitable for fixing tiles to a surface, the adhesive comprising a homogeneous viscous adhesive base having a viscosity of greater than 200 Pa at a shear rate of 1 s-1, particulate matter distributed substantially evenly in the viscous adhesive base, the particulate matter being: of maximum and minimum dimension in the range 0.1 to 2mm and being non-spherical and also non-spheroidal. The particulate material may present one or two flat side(s), when viewed in silhouette, and may be of broken glass.

Description

Tile adhesive The present invention relates to a tile adhesive composition.

The tiling of surfaces by the application of a plurality of tiles is a well-established practice. Tiling typically comprises the steps of preparing a sound and usually flat surface such as of a wall, applying to that surface a layer of adhesive and applying tiles to that adhesive. The adhesive may come in many forms such as a cementitious adhesive and application to the prepared surface of the adhesive is normally by means of a trowel. Use of a trowel with a castellated edge enables a layer of adhesive to be applied in ridges of constant thickness such that when a tile is applied the ridges of adhesive compress, and expand into intervening troughs, so as to accommodate variations in the tile and the wall, so that adjacent tiles may be attached with their outer surfaces substantially coplanar to give both an attractive and more easily maintained finish.

For a tile adhesive to be effective it must be fluid enough that it can be readily applied to a surface on which a tile is to be attached yet viscous enough so that once a tile is attached the tile does not move under its own weight (otherwise termed slip or slump) particularly when the tile is attached to a vertical surface were tile slippage, due to slump of the adhesive particularly underthe weight of the tile, can occur. Provision of a too viscous composition whilst potentially avoiding slump of the adhesive prevents the adhesive distorting sufficiently to adequately coat a tile, in which case a tile may simply fall off or to make it problematic to adequately level a tile compared to surrounding tiles potentially resulting in a tile cracking or incorrect outplacement.

Problem addressed by the invention There is therefore a need for a tile adhesive which is easily applied but which does not slump when supporting a tile under gravity.

Further, whilst a tile adhesive may be prepared with shear thinning characteristics such that it can be shaped and extruded at a lower viscosity than that present when not under shear this presents particular problems if the composition is to be supplied in the form of a premixed composition. Very high viscosity under low shear creates problems with extruding and extracting premixed composition. For example, a tube from which adhesive is extruded through an orifice will comprise composition that is under low shear, except at the point of extrusion. Hence, even a shear thinning composition can be difficult to exclude.

There is therefore a need for a tile adhesive which whilst providing a reduction of viscosity on extrusion nevertheless provides an anti-slump effect greater than that which can be attributed any shear thinning effect alone. Whilst many forms of tiles are available the most commonly used, and the most relevant in the present disclosure, are ceramic tiles, these being relatively heavy and hence prone to slumping or slipping whilst the adhesive is setting.

Prior art

An example of an adhesive suitable for use with ceramic tiles is provided in WO 01/77242 which discloses a water resistant and lightweight aqueous adhesive composition based upon an acrylic ester binding agent.

Various filling agents are known for use with adhesives. Typically filling agents comprise very small particles including glass particles having a particle size from 100 nm to 20 pm as disclosed in US 2008/0293872 and US 2008/0287574. Small particles affect viscosity by acting in a space-filling manner.

Adhesives comprising large particles acting as a spacer are known such as in US 4759962 and W02010/070355. In these instances the intention is that the particles act as an offset, bridging between a surface to be adhered and a surface to be adhered to such that a given distance of approach of the two surfaces occurs. This is not strictly applicable when a adhering ceramic tiles as imperfections or intentional irregularities in tiles and in surfaces to which the tiles are to be adhered is usual.

The invention The present invention in its various aspects is as set out in the appended claims. The present invention provides a tile adhesive composition. Specifically, the invention provides an adhesive composition suitable for fixing tiles to a surface, the adhesive comprising: a homogeneous viscous adhesive base having a viscosity of greater than 200 Pa at a shear rate of 1 s i) particulate matter distributed substantially evenly in the viscous adhesive base, the particulate matter being: A. of maximum and minimum dimension in the range 0.1 to 2mm B. non-spherical or non-spheroidal preferably C. the particulate matter comprising between 5 and 35% by volume of the adhesive.

Composition of product accordinci to the present invention A composition according to the present invention comprises the following components: Particulate component Base composition Particulate component The particles for use in the present invention are non-spherical or spheroidal. A spheroidal particle is a particle which is a distorted sphere and which has no corners.

In practice, spherical and is for Idol particles supplied industrially often comprise the occasional broken particle. Hence, if this were of concern then provided that such particles comprised less than the required weight percentage of the total composition then such material would still not be suitable for the present invention. However, it is preferable that the only particles intentionally introduced into the composition are of a substantially similar geometry. An intentional combination of spheroidal/spherical particles and angular particles is undesirable.

The particles are of maximum and minimum dimension in the range 0.1 to 2mm, preferably between 0.15 and 1.5mm, more preferably from 0.21 to 1.4mm, these figures representing 90% of the particulate material by weight retained on a sieve of the lower dimension and passing a sieve of the higher dimension.

The angularity of a particle can be determined by viewing particles under a microscope, the particles resting on a hard flat surface, such as a glass surface and lighting been arranged such that the particle can be seen as a silhouette.

When viewed in silhouette the particles of the present invention preferably disclose one flat side, the particles preferably disclose more than one flat side and even more preferably the flat sides are adjacent flat sides coming together to an actual or notional point where the sides intersect. Even more preferably, the particles comprise 3 or more flat sides and 2 or more points of intersection of those sides. A particle comprising a plurality of flat sides but no points between the sides is less preferable than a particle comprising points of intersection of flat sides. Particles comprising 6 or more flat sides are generally not preferred as these start to approximate to spheroidal particles. At least one angle created by an actual or notional intersection of 2 adjacent flat sides is preferably 1300 or less, preferably 900 or less, most preferably 70° or less.

In the above considerations, the criteria are satisfied for the particles when 90% of the particles present in the relevant size range meet a particular criteria. Similarly, it can be said that if 90% of the particles, preferably 80% of the particles, more preferably 70% of the particles do not meet the criteria used to define the present invention then such a composition based on such particles may not be within the scope of the present invention. For example, provision of sufficient spherical particles can override the benefit of fewer, if otherwise adequate, angular particles.

For practical purposes it is usually immediately evident whether a particle is spherical, irregular but rounded or angular. However if that were to arise then a flat side of a particle is a side which comprises at least 10%, preferably at least 20%, most preferably at least 30% of the length of the circumference of the silhouette. Similarly, particles which are platelets, i.e. have a minimum dimension less than a tenth of the maximum dimension are not considered particles for the purposes of the present invention, this naturally also including particles which are rods.

Most preferred particles contain at least one Straight plane (minimum length 50% of the particle size, for example particle size is 1mm that particle should have one plane of at least 0.5mm in length).

Also for practical purposes it is rare that commercially available material has perfectly flat sides when viewed in silhouette. Hence, for the purposes of the present invention a flat side is a side which approximates to a straight line deviating by not more than 10% of its total length from a notional straight line between endpoints of the side. In practice it is usually very easy to identify what looks like a straight side, the definition is merely presented to remove any ambiguity.

It has been found that by the use of irregular glass particles, those glass particles being derived from broken glass the ease of placement of a tile and pushing that tile so as to give a desired adhesive thickness and also the anti-sag property is much improved. The present invention therefore preferably employs irregular glass particles.

The present invention therefore preferably employs glass particles derived from broken glass and preferably, that broken glass is not tumbled broken glass.

Investigation has shown that particular broken glass commercially supplied is tumbled, or treated to some similar process so as to remove sharp corners from the particles.

Experiment has shown that such material does not correspond to a preferred material as determined by the above parameters. Tumbling is a process normally applied to broken glass so that a degree of rounding of sharp edges of the glass is removed.

Further, the preferred volume fraction of particles in the composition has been found to be in the range of from 5% by volume to 35% by volume, more preferably in the range from 10 to 30% by volume of the adhesive, most preferably from 15 to 30%. This is particularly so when irregular broken glass particles are used, such as those of preferable geometry as previously defined.

The density of the preferred glass particles is: 2.7 glcm3. The preferred base density is 1.6Ogfcm3. The preferred compositions density is at 40% inclusion of particulate matter is: 1.90g/cm3.

Using these figures and equivalence between a preferred weight proportion of particulate matter and volume fill of that particular matter can be established for the purposes of defining the present invention.

Base Composition -Physical Characteristics For the purposes of the present invention provided that the base composition adheres to the particulate matter, that is it has the property of wetting the service of the particular matter then the particular chemistry of the composition so far as providing a solution to the problem addressed by the invention is not particularly significant.

Hence, base compositions which are based upon aqueous polymer polymer emulsions, nonaqueous polymer compositions and cementitious compositions are all envisaged.

The base composition, or base for short, is best defined by its physical characteristics.

The base is required to be viscous as the particles/particulate matter alone is in itself insufficient to prevent a tile sagging under its own weight. The minimum viscosity required is 200 Pa at a shear rate of 1 5* As will be appreciated, a higher volume fill of particular matter can compensate for a low viscosity of the base so as to provide a final composition of acceptable dispensing characteristics.

A preferred maximum viscosity for the base composition is 1200 Pa at a shear rate of 1 s* A preferred viscosity range for the base composition is from 400Pa to l000Pa at a shear rate of 1 The viscosity is determined using a "Advanced Rheorneter AR 2000". The software used was from TA Instruments, product version V5.7.0. The head geometry used was STD Steel Cone, Diameter -20mm, Angle -(deg:min:sec) 2:00:00, Truncation gap - 58 micro meters.

Acceptable dispensing characteristics, which also provide acceptable viscosity characteristics for the purposes of stopping a tile sagging under its own weight when 2 mm to 5mm of adhesive is present on a standard tile (250 mm x 330 mm weighing 1050g +1-5g) can be determined using an extrusion test as follows: Extrusion Test Method: 1. Material is filled (roughly 11 Og depending on the SG of the test material) into a cylinder, 70mm in length and 38mm in diameter.

2. The material is extruded at 30 psi, over a 38mm diameter circular metal disk through a metal cylinder.

3. Material is extruded through a 4mm diameter Aperture 4. The results are expressed as the weight of material extruded after 20 seconds Acceptable limits for results of the test are as follows:

Table 1.1

Extrusion (limits) (1) 80g -90g Extrudability unaffected compared to base material (No difference in ease of use) (2) 51g -80g Extrudability negatively affected (More difficult to use) (3) 20g -51g Extrudability Severely affected (Extremely difficult to use) (4) 20g and below Extrudability affected un-gunnable (5) 90g and above Extrudability affected Too fluid A material which does not fall within any of categories 1 to 5 in the above table is considered to be acceptable as an adhesive according to the extrusion test. I.e. a material for which in the extrusion test more than 20 g and less than 90 g are extruded in the 20 second time interval passes the test.

Base composition -Constituents The base composition may be an aqueous or non-aqueous paste.

A paste is a composition readily recognised by a person skilled in the art. A paste is a material of a viscosity such that when a material is placed upon a surface it substantially retains its form without flattening or flowing over the service under normal timescales. Hence, a cylindrical bead of a paste extruded upon a horizontal surface retains a ratio of height to which of less than 1:10 when left over a one-hour period.

Clearly, a material not being a paste, such as being a liquid will rapidly flow and level out providing a thin sheet. Such liquids are not within the scope of the present invention.

A base composition according to the present invention is extrudable from a container of typical dimensions of a mastic cartridge. For example, a base composition suitable for use in the present invention can be extruded from a cylinder of 38 mm diameter having a circular cross-section planar piston fitting the cylinder at a first end and at a 2nd end a circular planar endwall having a 4 mm diameter hole. For the material to be suitable for use in the present invention more than 1 g of material per second is extrudable from such a cylinder when a force of 30 psi (206 kPa) is applied to the piston, at 25°C. When considering such a test for a material of unknown density then an assumed material density of 1.5 g/cc may be used for an adhesive composition.

Aqueous cementitious base composition A suitable cementitious composition is as follows:

Table 2.1

Material Typical weight Particulate matter 50% High Alumina Cement 6% Calcium Carbonate (fine ground) 5% Ordinary Portland Cement 30% Hydrated Lime (typically no bigger than l5pm) 2.5% Polymer 5% Accelerator 0.1% Cellulose Thickener 0.5% Retarder 0.2% Fibre 0.5% Water To 100% Aqueous polymeric base composition Compositions as now disclosed are suitable for use as the base composition in combination with the angular particles of the present invention.

The aqueous base composition comprises: (a) an aqueous organic binding agent preferably comprising an aqueous dispersion and including a poly (acrylic ester) or copolymer thereof, particularly a copolymer comprising an acrylate and a methacrylate, i.e. a copolymer of an acrylic ester and a methacrylic ester.

(b) filler, for the purposes of the present invention a filler is considered to be a material having a particle size of less than 100pm.

The binding agent preferably comprises a copolymer comprising an acrylate and a methacrylate, although other comparable repeat units may be provided instead or in addition.

Preferably at least 70 mol %, especially at least 85 mol%, particularly at least 95 mol % and most particularly substantially all of the polymer is made up of acrylate and methacrylate repeat units. The copolymer preferably comprises 40-60 mol%, especially 45-55 mol% of each of the acrylate and the methacrylate. More than one type of acrylate and more than one type of methacrylate may be present, it is preferred at least 75 mol% and preferably at least 85 mol% of each of the acrylate and methacrylate be of a single type. In particular, it is preferred that the acrylate be 2-ethyl hexyl acrylate andlor butyl acrylate (and if both preferably a minor quantity, say less than 10 mol % of the latter, mol% meaning a percentage of the constituent monomers of the polymer), and that the methacrylate be methyl methacrylate and/or butyl methacrylate (and if both preferably a minor quantity, say less than 10 mol%, of the latter).

Other polymerisable monomer components may be present in the binding agent. For example acrylic acid and/or methacrylic acid may be present.

The preferred amount of the total of acrylic acid and methacrylic acid is less than 5, particularly less than 1.5, for example 0.5-5, especially 0.75-1.5, say about 1, mole % based on the number of moles of acrylate and methacrylate in total moles of monomers in the copolymer.

The binding agent may also include, in addition to a base polymer (preferably that referred to above) one or more of the following: (a) a coalescing solvent, such as a glycol ether for example 2 butoxy ethanol; (b) an antifoaming agent for example a silicone; and (c) surfactant which if present is preferably polymerizable or polymeric or otherwise becomes inactive once the adhesive or grout has been installed (polymeric compositions which contain such surfactants may be referred to as "surfactant free" since the surfactant is not available to perform a surfactant function in the installed product, i.e. when the base composition sets).

d) thickeners may be added such as polyacrylic acid polymers and/or cellulose thickeners, examples of which include methyl hydroxy propyl cellulose, carboxy methyl cellulose and ethyl hydroxy cellulose. The preferred amount of such thickeners is from 0.1 to 5% by weight based on the total weight of the composition. The binding agent (together with the other component if appropriate) preferably gives the overall composition a pH in the range pH 7 to 9. The binding agent preferably has UV resistance and cement resistance, in addition to the good water resistance for which is was primarily selected.

e) Furthermore, the binding agent preferably comprises a material having a minimum film forming temperature of 10°C or less, especially 5°C or less, for example about 3°C. The polymer components of the binding agent preferably have a glass transition temperature (Tg) of less than room temperature (20°C), more preferably from 9 to 17°C, especially 11 to 15°C and most especially about 13°C.

A preferred binding agent is an ionic aqueous emulsion marketed by Rhodia under the trademark Rhoximat DEC 27 1) A cationic scavenger may be added in order to reduce or to prevent thickening of the adhesive composition during storage. A suitable cationic scavenger is a phosphate material, for example sodium hexametaphosphate.

g) Various other additives may be provided depending upon the precise use of the composition. For example, one may include one or more fungicides, one or more pigments, one or more dispersants, one or more cross-linking agents for the copolymer of the binding agent, silica, and other additives conventionally used in the adhesives industry.

The base composition as described above is particularly useful for bonding ceramic tiles, and also for attaching tiles to verflcal surfaces.

The following organic binding agents components may be used in addition to or in place of the preferred polymer components mentioned above: one or more homo-or co-polymers of acrylic acid, methacrylic acid, acrylamide, methacrylic esters, vinyl esters, itaconic esters, vinyl ethers, olefins such as ethylene, styrene, butadiene, and acrylonitrile or vinylidene chloride. By such homo-or co-polymers we include carboxylated versions of the basic polymers, such as carboxylated styrene butadiene acrylonitrile. Acrylic or styrene acrylate co-polymers are preferred for some uses.

Base composition Example 1 An adhesive composition was prepared from the following components.

Table 2.2

Component % by weight Water 49.28 Dispex G40 0.79 -10-Acticide BX 0.21 Acticide BW 0.21 Butyl Diglycol Acetate 1.27 Carbopol EZ1 0.79 Bermocoll E481 FQ 0.24 Attagel 30 0.01 AMP 95 0.31 Arbocel B400 2.36 Rhoximat Dec 27 34.29 WitcoYl5O78 1.02 Scotchlite KI 8.70 Non-Aqueous Base Composition Compositions as now disclosed are suitable for use as the base composition in combination with the offsetting particles of the present invention.

The one component non-aqueous base composition comprises a polymer selected from a silane terminated polyurethane or a silane terminated polyether. The polymer is typically a liquid.

The polymer is present in an amount of up to 100% by weight, such that the amount of polymer present makes up 4-50% by weight, more preferably 5-20%, and most preferably 10% by weight of the base.

Preferably the polymer is a telechelic polymer (i.e. a polymer carrying at least one functionalised end group that has the capacity for selective reaction to form bonds with another molecule). More preferably the polymer is a telechelic polymer with difunctional or trifunctional end groups. Even more preferably both ends of the polymer have at least one functionalised end group, and most preferably both ends of the -11 -polymer have trifunctional end groups. Preferably the terminal functionalities are alkoxy groups, such that difunctional end groups give rise to two alkoxy groups pendant from the Si atom in a silane terminating group, and such that trifunctional end groups give rise to three alkoxy groups pendant from the Si atom in a silane terminating group.

Examples of suitable polymers include Polymer ST61, S303H, S203H, SAX26O, SAX 350, SAX51O, SAX53O and SAX 80 available from Kaneka, Polymer ST75 and Poiymer ST77 suppiied by Hanse Chemie; Geniosil SIP EIO, Geniosil SIP E15, Geniosil STP E30 and Geniosil STP E35 supplied by Wacker; Desmoseal SXP 2662, Desmoseal SXP 2458 and Desmoseal SXP 2636 supplied by Bayer; and, Spur+* 1o1OLM, Spur* 1O5OLM and Spur+* 1O15LM supplied by Momentive.

Preferred polymers are Spur+* IO5OLM supplied by Momentive; and Geniosil SIP E15 and STP E35 both supplied by Wacker. The most preferred polymer is SAX 260.

The one component sealant composition of the base may also comprises a plasticiser and does a filler.

Looking first at the plasticiser, this must be compatible with the polymer and by this we mean that it will mix into the system without bleeding back out. The plasticiser has the function of softening and extending the final cured polymer network, and providing extra liquid components so that the mineral fillers are fully wetted-out. The plasticiser can be present in any amount sufficient to fulfil this purpose. Typical amounts of plasticiser are 0-40% of the composition, preferably 5-10%. Suitable plasticisers are derivatives of benzoic acid, phthalic acid (e.g. phthalates, such as dibutyl-, dioctyl-, dicyclohexyl-, diisooctyl-, diisodecyl-, dibenzyl-or butylbenzyl phthalate), trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid and citric acid, and derivatives of polyester, polyether, hydrocarbon mineral oil and the like.

Preferred plasticisers are alkyl esters for example phthalates, adapates, sebacates and benzoates. An especially preferred example is Hydrocarbon Oil such as Hydrosel G3H available from Total.

With regard to the filler, a preferred rheological filler is one which imparts the property of thixotropy to the base of the invention, and to the base as such. A material is -12-thixotropic if it will flow under the application of shear force, then set up and retain its shape once the shear force is removed.

Preferred rheological fillers are precipitated calcium carbonates, for example having an average size within the range of 40-70 nm, and/or a specific surface area of 15-35 m2/g. Alternative rheological fillers such as fumed silicas, bentonites and other clays can however also be used.

It is preferable that when the rheological filler is precipitated calcium carbonate, the precipitated calcium carbonate is coated (e.g. during manufacture) for example with calcium stearate (or a similar material that can impart full or partial hydrophobicity to the particles). The nature and quality of this coating influences rheology, since the amount of residual hydrophobicity governs the level of structuring that the filler imparts on the sealant, and further the coating prevents the filler from absorbing key raw materials of the formulation and rendering them ineffective. It is preferable that the precipitated calcium carbonate has a coating level of 0-3.5 % of the filler weight.

Preferably the filler also comprises a non-rheological filler to reduce the amount of rheological filler present and thus reduce cost, and this non-rheological filler can be any of the commonly used mineral fillers, for example ground calcium carbonate or talc. Ground calcium carbonate is preferred, and it is preferable to coat the ground calcium carbonate, typically with calcium stearate or similar material that can impart full or partial hydrophobicity to the particles.

When the filler comprises a mixture of precipitated calcium carbonate and ground calcium carbonate, the amount of precipitated calcium carbonate in the composition is preferably 10-100%, more preferably 10-80 %, even more preferably 10-60 %, and most preferably about 25%, by weight of the total amount of total base composition.

Most preferably the amount of precipitated calcium carbonate in the composition is about 45% by weight of the total amount of filler. The amount of ground calcium carbonate in the composition is 0-90 %, more preferably 20-80 %, even more preferably 20-60 %, and most preferably about 35%, by weight of the total base composition. Most preferably the amount of ground calcium carbonate in the composition is 55% by weight of the total amount of filler. -13-

Examples of suitable precipitated calcium carbonates include Winnofil SPT Premium, Winnofil SPM, Socal 322 and Socal 312 (all produced by Solvay); Neolight SS and Neolight SP (produced by Takehara); Calofort SM, Calafort SV and Calofort SE (produced by Speciality Minerals); and Hakuenka CCR, Hakuenka CCR-S, Hakuenka CC and Viscolite OS (all produced by Shiraishi Kogyo Kaisha Ltd). Of these precipitated carbonates, Winnofil SPT Premium, Winnofil SPM, Calofort SM, Neolight SS, Socal 312, Calofort SE, Socal 322, Hakuenka CCR-S and Hakuenka CC are preferred. Winnofil SPT Premium, Winnofil 5PM, Calafort SM, Neolight SS, Socal 312 and Calofort SE are more preferred. Calofort SV is most preferred.

Examples of suitable ground calcium carbonates include Omya BLR3, Britomya BSH, Omya F6, Omya F7, Omya F8 and Omya F9 (all produced by Omya); Microcarb ST- 10, Microcarb ST-IOH, Microcarb MC3O HE, and Microcarb ST9O (alt produced by Minelco); and Carbital 11OS, Carbital SB, Cretaplast 37, Cretaplast 67, Honcal iT, Imerseal 50, Imerseal 75, Polcarb 405, Polcarb 50S, Polcarb 60S, Polcarb 5, and Polcarb SB (all produced by Imerys). Of these ground carbonates, Omya BLR3, Microcarb ST-b, Britomya BSH, Polcarb 505 and Carbital 1105 are preferred, and Carbital I1OS is most preferred.

The one component base composition will also contain adhesion promoters (for example Silquest Al 110 supplied by Momentive Performance Materials); and reaction catalysts (for example a tin catalyst, one example of which is Tibkat 223 available from Tib Chemicals.

Table 2.3

Component % by weight Polymer 2&8% Pigment 0.8% Rheological Filler 26.0% Non-Rheological filler 34.4% Stabilizer 4.4% -14 -Adhesion Promoter 1.0% Catalyst 0.4% Plasticizer 6.1% Additions to the base comQosition To the base composition are added additional components and specifically, angular particles so as to provide a composition of the present invention. Whilst preferred, it is not necessary that the base composition be prepared as such be for further components added, so long as all the components are present in the final composition.

A composition according to the present invention is preferably prepared first by preparing a base composition, as set out above. To this base composition are added particles. The advantage of adding angular particles to a pre-prepared base is that the preferred angular particles used in the present invention are relatively abrasive and minimising the mixing required reduces machine wear.

The adhesive composition of the present invention also comprises 10 to 40% by weight of particles. That is, of the total weight of a sample of the adhesive composition according to the present invention from 10 to 40% of the weight of the composition is derived from the addition of particles.

A particle in the sense of the present invention is a particle being between 0.21 to 1.5 mm in size. Specifically, a particle passing through a sieve having a mesh size of 1.5 mm and being retained on a sieve having a mesh size of 0.21 mm is a particle of size suitable for use in the present invention. Such a particle size is, as known by people skilled in the art determined when set of suitable mesh size have particular material placed upon them and are agitated so as to allow particles to be separated.

The particles for use as particles in the present invention are preferably glass particles.

The glass particles are preferably a conventional silicate glass specifically a soda-lime glass also known as a soda-lime-silica glass. -15-

The particles for use as particles in the present invention are preferably obtained by breaking larger pieces of soda-lime glass such that the particles are created by the fracturing glass at ambient temperature. This gives rise to particles having sharp edges which is a specific aspect of angularity of a particle.

The particles for use as particles in the present invention may preferably be derived from recycled glass, such as recycled bottle glass. This is obtained by taking items to be recycled breaking them in a mill and soothing the resultant particles to obtain particles of size as defined above.

Particles derived from broken glass may be subjected to the conventional process of tumbling. This process removes sharp edges.

Dispensing of the composition in use Adhesive for use in and of the present invention is preferably supplied in, and dispensed from, mastic cartridges or packaged in a flexible walled container having an outlet portion comprising an orifice. Mastic Cartridges are in the form of elongate cylinders having a first end with a nozzle and a second end with a moveable stopper, such as for use in a conventional mastic gun so as to exclude a cylinder of adhesive onto a surface, such as into the space mentioned above, the space imphcitly having a backplane onto which the adhesive adheres. This method of application has been found advantageous in that the cylinders or flexible walled containers of adhesive applied to the surface enable the particles in the adhesive composition to readily rearrange so as to give rise to the above benefits of ease of insertion to a given depth and anti-sag.

Compositions according to the present invention are preferably packaged in a flexible walled container having an outlet portion, the outlet portion comprising an orifice for extrusion of the composition, the orifice being of maximum and minimum cross-sectional dimensions between 3 and 20 times that of the average particle size of the particulate matter comprising the composition. The benefit of this packaging method is that compositions prepared containing large size particular matter, whilst needing to be extruded from a defined and substantially rigid orifice so as to give effective application to a surface tend to block such an orifice and the use of a flexible walled container allows manipulation of the walls of the container, such as manually, to substantially vary outlet pressure and, in particular, provide a degree of suction in some configurations so as to release or at least disturb any blockage sufficient that the -16-material may continue to be extruded. In this embodiment only the size of the particles is constrained and not their shape, further, suitable compositions are not limited to tile adhesive compositions.

A composition according to the present invention is preferably prepared first by preparing a base composition, as set out above. To this base composition are added particles. The advantage of adding angular particles to a pre-prepared base is that the preferred angular particles used in the present invention are relatively abrasive and minimising the mixing required reduces machine wear.

The attached figures comprise; Figure 1 and Figure 2, methods of classification of particle shape; Figure 3 and 4, photomicrographs of suitable particles; and Figure 5, photomicrographs of unsuitable particles.

Evaluation of Product Characteristics As mentioned above, the benefits of the present invention arise because the composition provides adhesion without tile slippage. The test used for determining this property is the tile slip test.

The slip test is summarised in the following table: -17-

Table 1.2

Tile Slip Test 1 Material must be easily hand applied through a 3- 4mm diameter aperture. Extrusion data must show a result above 20g, see extrusion test method.

Extrusion results below 20g will count as a fail.

2 A single perimeter bead is hand extruded through a 3-4mm diameter nozzle to a 250mm x 330mm tile ________________ (1050g ±5g) 3 The tile is firmly pressed against a vertical wall. Tiles are pushed against the wall, leaving a gap of no less than 2.0mm between the tile and the wall.

4 Vertical movement is measured once the tile is released.

Tile Slip Failure Criteria 1 Cannot be easily extruded though a 4mm diameter aperture using a hand skeleton gun [Extrusion result of less than 20g or below] 2 Tile Slips after being bonded to vertical plain (y downward movement after releasing tile). Movement greater than 0.5mm is classed as slip, and the test is observed for 30mm 3 Tile Falls from the vertical plain Acceptable dispensing characteristics, which also provide acceptable viscosity characteristics for the purposes of stopping a tile sagging under its own weight when 2 mm to 5mm of adhesive is present on a standard tile (250 mm x 330 mm weighing 1050g +1-5g) can be determined using the extrusion test as above. -18-

Experimental Data A base composition was prepared the base as provided above in table 2.3.

Table 3.1

Base Material Tile Slip Test Extrusion Test FAILED 83g (criteria 2) OK The base composition chosen is unsuitable as an adhesive as such because even though the viscosity of the composition is suitable and the properties of the composition or otherwise suitable for use as a tile adhesive the slip test is failed.

Hence, this provides a realistic reference to existing products which are of suitable viscosity and intended for the purpose but do not have the benefits of the present invention.

Preparation of compositions according to the present invention A base composition as described above was prepared and to this was added angular particles in defined amounts by weight, as set out in the results tables. The compositions were mixed using standard equipment as commonly available in the industry.

Compositions as prepared above were tested and the results are presented below in

tables 3.2 to 3.5.

The tile slip test and the extrusion test's as detailed above were then carried out on a series of samples, the compositions and the results are as detailed below. These results show that preferred compositions according to the present invention provide a composition which acts effectively as a tile adhesive, the tiles passing the slip test, -19-such that the tiles are held effectively in place whilst the composition also passes the extrusion test showing that the composition can be effectively dispensed.

Table 3.2 Angular Particles Loading (wrtw) SAMPLE 1 SAMPLE 2 SAMPLE 3 Vitrosil 0.075mm 0.210mm 0.21mm -0.70mm Tile Slip Extrusion Tile Slip Extrusion Tile Slip Extrusion Test data Test data Test data 10% FAILED 92.26g FAILED 85.49g PASSED 85.16g _________ (2) __________ (3) __________ __________ __________ 20% FAILED 92.03g FAILED 83.48g PASSED 81.32g _________ (2) _________ (3) _______ ______ __________ 30% FAILED 84.28g FAILED 58.16g PASSED 86.45g _________ (2) __________ (3) __________ __________ __________ 40% PASSED 40.17g FAILED 44.84g PASSED 65.5g _________ ___________ ___________ (2) ___________ ___________ ___________ 50% PASSED 11.08g PASSE 30.33g PASSED 41.62g

D

60% FAILED Og FAILED 0.77g PASSED 30.07g ____________ (1) _____________ (1) _____________ _____________ _____________ 70% FAILED Og FAILED Og FAILED 0.85g ___________ (1) ____________ (1) ____________ (1) _____________ 80% FAILED Og FAILED Og FAILED Og ___________ (1) ___________ (1) ________ (1) _____________ 90% FAILED Og FAILED Og FAILED Og ___________ (1) ____________ (1) ____________ (1) _____________ -20-Table 3.3 Angular Particles Loading (wrtw) SAMPLE 4 SAMPLES SAMPLE 6 0.2lmm-1.4Omm 5.0-10mm 2mm Tile Slip Extrusion Tile Slip Extrusion Tile Slip Extrusion Test data Test data Test data 10% PASSED 82.57g FAILED 23.79g* FAILED 55.99g __________ (3) (3) 20% PASSED -80.62g FAILED 15.93g* FAILED 17.82g ___________ ____________ ___________ (1) __________ (1) _________ 30% PASSED 83.67g FAILED 18.28g* FAILED 11.04g ___________ ____________ ____________ (1) ____________ (1) ____________ 40% PASSED 83.64g FAILED 19.76g* FAILED 4.42g ___________ ____________ ___________ (1) __________ (1) _________ 50% PASSED 40.33g FAILED 13.679* FAILED Og ___________ ____________ ____________ (1) ____________ (1) ____________ 60% FAILED 5.64g FAILED 6.569* FAILED Og ___________ (1) ____________ (1) ____________ (1) ____________ 70% FAILED 1.15g FAILED Og FAILED Og ___________ (1) ____________ (1) ____________ (1) ____________ 80% FAILED Og FAILED Og FAILED Og ___________ (1) ____________ (1) ____________ (1) ____________ 90% FAILED Og FAILED Og FAILED Og ___________ (1) ____________ (1) ____________ (1) ____________ Table 3.4 Spherical I spheroidal particles Loading (wrtw) SAMPLE 7 SAMPLE 8 SAMPLE 9 Poravor Poravor 0.21-0.7mm Poravor 0.5-1.0mm 0.10-0.21mm ________ _________ _________ _________ Tile Slip Extrusion Tile Slip Extrusion Tile Slip Extrusion Test data Test data Test data 10% FAILED 70.59g FAILED FAILED _________ (2) _________ (2) __________ (2) __________ 20% PASSED 50.86g FAILED 82.4g FAILED 2.03g ________ _________ ________ (2) ______ (1) _________ 30% FAILED Og FAILED 18.43g FAILED 9.49g ___________ (1) ____________ (1) ____________ (1) ____________ 40% FAILED Og FAILED 5.94g FAILED 2.04g ___________ (1) ___________ (1) ________ (1) _____________ 50% FAILED Og FAILED 18.88 FAILED 0.334g ___________ (1) ____________ (1) ____________ (1) _____________ 60% FAILED Og FAILED 18.39g FAILED 6.21g ___________ (1) ____________ (1) ____________ (1) _____________ 70% FAILED Og FAILED Og FAILED 10.3g ___________ (1) ___________ (1) ________ (1) _____________ 80% FAILED Og FAILED Og FAILED Og ___________ (1) ____________ (1) ____________ (1) _____________ 90% FAILED Og FAILED Og FAILED Og ___________ (1) ___________ (1) ________ (1) _____________ -21 -Table 3.5 Spherical / spheroidal particles Loading (wrtw) SAMPLE 10 SAMPLE 11 SAMPLE 12 SAMPLE 13 Poravor 1.0-1.40mm Plastic Beads 3mm Poravor 1.40 -2.0mm STARLITE BEAD __________ _________ _________ __________ __________ __________ (1.40mm to 1.7mm) Tile Slip Extrusion Tile Slip Extrusion Tile Slip Extrusion Tile Slip Extrusion Test data Test data Test data Test data 10% FAILED 5.85g FAILED 33.8g * FAILED Not Not ________ (1) _________ (1) _________ (1) _________ Tested Tested 20% FAILED 3.26g FAILED 32.53g FAILED 2.03g Not Not _________ (1) __________ (1) ___________ (1) ___________ Tested Tested 30% FAILED Og FAILED 24.63g * FAILED 9.49g FAILED ________ (1) _________ (1) _________ (1) _________ (3) 83.27g 40% FAILED Og FAILED 15g * FAILED 2.04g FAILED ________ (1) _________ (1) _________ (1) _________ (3) 58.67g 50% FAILED Og FAILED 6.32g * FAILED 0.334g FAILED ________ (1) ________ (1) ______ (1) _________ (3) 26.90g 60% FAILED Og FAILED Og FAILED 6.21g Not Not _________ (1) _________ (1) __________ (1) __________ Tested Tested 70% FAILED Og FAILED Og FAILED 10.3g Not Not ________ (1) ________ (1) ______ (1) _________ Tested Tested 80% FAILED Og FAILED Og FAILED Og Not Not ________ (1) ________ (1) ______ (1) _________ Tested Tested 90% FAILED Og FAILED Og FAILED Og Not Not ________ (1) _________ (1) _________ (1) _________ Tested Tested Table 3.6 Key to tables * None of the extra added material was extruded, only base material Test chamber completely evacuated after 13 seconds, result scaled up to 20 seconds for comparison The above results demonstrate the efficacy of the present invention. -22-

The method of classification of the particle shape as provided in figures 1 and 2. Using that classification the particles used above can be classified as follows:

Table 4.1

SAMPLE SAMPLE SAMPLE SAMPLE SAMPLE SAMPLE

1 2 3 4 5 6 Vitrosil 0.210mm 0.21mm -0.21mm -5.0 -2mm 0.075mm 0.70mm 1.40mm 10mm Shape Very Very Very Very Very Very Description Angular Angular Angular Angular Angular Angular to to to to to to Angular Angular Angular Angular Angular Angular Medium Medium Medium Medium Medium Medium Sphericity Sphericity Sphericity Sphericity Sphericity Sphericity to Low to High to Low to Low to Low to High ____________ Sphericity Sphericity Sphericity Sphericity Sphericity Sphericity Arethe No No No No No No particles spherical? Do the Yes Yes Yes Yes Yes Yes majority of particles contain more one straight plane? Do the Yes Yes Yes Yes Yes Yes majority of particles contain more than one straight plane? Do the Yes Yes Yes Yes Yes Yes majority of particles contain at least one instance straight planes intersect to form an angle? -23-

Table 4.2

SAMPLE 7 SAMPLE SAMPLE 9 SAMPLE SAMPLE SAMPLE SAMPLE 8 10 11 12 13 Poravor Poravor Poravor Poravor Plastic Poravor STARLITE 0.10-0.21 0.21-0.7 0.5-1.0 1.0-1.40 Beads 3 1.40 -2.0 BEADS mm mm mm mm mm mm 1.40 -1.70 mm Shape Rounded Rounded Rounded Rounded to Well Rounded Highly Description to Highly to Highly to Highly Highly Rounded to Highly Rounded Rounded Rounded Rounded Rounded Rounded Medium Medium Medium Medium Medium Medium High Sphericity Sphericity Sphericity Sphericity Sphericity Sphericity Sphericity to High to High to High to High to High to High Sphericity Sphericity Sphericity Sphericity Sphericity Sphericity Are the No No No No No No Yes particles spherical? Dothe No No No No No No No majority of particles contain more one straight plane? Dothe No No No No No No No majority of particles contain more than one straight plane? Dothe No No No No No No No majority of particles contain at least one instance straight planes intersect to form an angle? -24 -