NZ232532A - Compositions comprising hydraulic cement, filler, organic polyisocyanate and an aromatic phthalate plasticiser: use thereof in preparing terazzo-type decorative surfaces - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £32532 23 2.5 3 2 Comt>fMo Specification Filec:: CiSSSI I. .35.G b. .O.. £>/OQ..:. i publication P«te: - ? 8 P.O. Journal. --Wo: .33.

NO DRAWIMS ZEALAND i PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION METHOD FOR THE PRODUCTION OP DECORATIVE CONCRETE COMPOSITIONS 1/We, IMPERIAL CHEMICAL INDUSTRIES PLC, a British company of Imperial Chemical House, Millbank, London SW1P 3JF, England hereby declare the invention for which I / we pray that a patent may be granted to me/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - (followed by page la) -1°- S 35139 o - • > - v J l J i ^ METHOD FOR THE PRODUCTION OF DECORATIVE CONCRETE COMPOSITIONS Various procedures for the formation of surfaces having a Terrazzo-like decorative effect employing rapidly curing cement compositions have been described in the past. Thus, U.K. Patent 1,348,381 describes a process for producing such surfaces employing cement compositions having as essential ingredients an hydraulic cement, a filler, water and an organic polyisocyanate, wherein said filler is in the form of fragments or coarse particles. After such cement composition has been spread, the surface is then ground or otherwise treated to expose the fragments or particles of filler, producing a surface having Terazzo- like decorative effect.

Somewhat similarly, U.K. Patent 1,360,394 describes an alternative method for producing such decorative surfaces. This alternative method involves a process wherein fragments of material are first bonded to the area to be surfaced"; a grout composition containing as essential ingredients an hydraulic cement, a particulate filler, water and an organic polyisocyanate is applied over the bonded fragments to fill in the gaps between them; and the surface is then ground or otherwise treated to produce a smooth surface having a Terrazzo-like appearance.

The above-mentioned patents both indicate that the appearance of the Terrazzo-like surface may be further enhanced by the application of one or more coats of a urethane surface-coating composition. However, the application of such an additional urethane layer has often resulted in the decorative surface taking on a milky or oily appearance. This milkness or oiliness results from plasticizers, included in the cement composition to improve its rheological properties, being extracted from the cement layer into the clear urethane sealant layer by the organic solvents employed in connection with the application of such urethane sealant layer. When the urethane sealant layer dries, the leached plasticisers, which are immiscible in the upper urethane layer, produce a milky or oily appearance which may detract from the enhanced;.,decorative effect for which such urethane sealant layer was applied. -2- S 35139 n 9 < , I J . „ Thus, it would be beneficial to possess a plasticiser which would desirably improve the rheological properties of the underlying cement composition and which would not mar the appearance of Terrazzo-like compositions which have been coated with a urethane sealant layer.

It has now been found that aromatic phthalates constitute a class of plasticisers which will provide such rapid-curing cement compositions with improved rheological properties and which due to their improved resistance to extractability and/or enhanced miscibility in the urethane sealant layer will not mar the appearance of such coated compositions. This finding is especially unexpected in view of the fact that closely related chemical compounds, such as dialkyl phthalates, will not exhibit such desirable extraction resistance and/or miscibility.

Accordingly, in one aspect, the present invention is directed to a method for producing a decorative surface comprising the steps of: (a) applying to the area to be surfaced a composition comprising : (i) an hydraulic cement; (ii) a filler in the form of fragments or coarse particles; (iii) water; ^ • < (iv) an organic polyisocyanate; and (v) an aromatic phthalate plasticiser; (b) treating the surface of the applied composition to expose the fragments or particles of filler; and (c) applying a layer of a liquid polyurethane-forming composition over the treated surface of step (b).

In another aspect, this invention relates to such a method including a preliminary step of S 35139 bonding fragments of material to the area to be surfaced, whereafter application of the coating composition over the bonded fragments fills in the gaps between them as a grouting composition.

In a further aspect, the invention relates to a curable composition comprising: (i) an hydraulic cement; (ii) a particulate filler; (iii) water; (iv) an organic polyisocyanate; and (v) an aromatic phthalate plasticizer.

In yet another aspect, the present invention is directed to decorative surfaces produced in accordance with the above-described methods.

The aromatic phthalate compounds which may be employed in the practice of this invention are, in general, compounds having the structural formula: 0 C-O-R' 0 wherein R is Cy-C.^ arylalkyl; or arylalkyl substituted on the aryl ring with methyl or -4- S 35139 0 0 • . ,~ t-J t j halogen; and R' is C-,-0^2 arylalkyl; arylalkyl substituted on the aryl ring with methyl or halogen, or C^-C^g alkyl (by which term is meant straight chain, branched or cycloalkyl).

Preferably : R is Cy-C^Q arylalkyl; and R'is alkyl.

For several applications, butyl benzyl phthalate is a particularly preferred aromatic phthalate. Compounds wherein R is benzyl and R' is cg~c1Q branched chain alkyl group for example a 2-ethylhexyl group also provide useful results.

As is employed herein the term "liquid polyurethane-forming composition" refers to a fluid composition comprising an organic solvent and a urethane-f orming component. In general, such urethane-forming component will be a one-component moisture-curable system or a two-component isocyanate/polyol system.

As is employed herein, the term "hydraulic cement" is used in its usual sense to denote the class of structural materials which are applied in admixture with water and thereafter harden or set as a result of physical or chemical changes which consume the water present. As well as Portland cement, this form includes: 1. Rapid hardening cements, as characterised by those with high alumina contents. 2. Low-heat cements as characterised by high percentages of dicalcium silicate and tetracalcium alumino ferrite and low percentages of tricalcium silicate and tricalcium aluminate.

S 35139 o o c. i: ,• -• »- o v, vi 3. Sulphate-resisting cements as characterised by unusually high percentages of tricalcium silicate and dicalcium silicate and unusually low percentages of tricalcium aluminate and tetracalcium alumino ferrite. 4. Portland blast-furnace cement as characterised by a mixture of Portland cement clinker and granulated slag.

. Masonry cements as characterised by mixtures of Portland cement and one or more of the following: hydrated lime, granulated slag, pulverised limestone, colloidal clay, diatomaceous earth or other finely divided forms of silica, calcium stearate and paraffin. 6. Natural cements as characterised by material obtained from deposits in the Lehigh Vally, USA. 7. Lime cements as characterised by oxide of calcium in its pure or impure forms and whether containing or not some argillaceous material. 8. Selenitic cement as characterised by the addition of 5 - 10Z of plaster of Paris to lime. 9. Pozzolanic cement as characterised by the mixture of pozzolana, trass kieselguhr, pumice, tufa, santorin earth or granulated slag with lime mortar.

. Calcium sulphate cements as characterised by those depending on the hydration of calcium sulphate and including plaster of Paris, Keene's cement and Parian cement. : «** \' '.'^-4 MAR 1992'y \ % S 35139 n ' < j i i <.

The preferred hydraulic cement is Portland cement. There may also be used white Portland cement which is a cement of low iron and carbon content manufactured from specially selected ingredients.

The filler for such Terrazzo-like uses may be in the form of mass-pigmented plastics fragments of thermoplastic or thermosetting polymers or copolymers, for example, nylon polymers, polyvinyl chloride, vinyl chloride/vinyl acetate copolymers, urea/formaldehyde polymers, phenol/formaldehyde polymers, melamine/formaldehyde polymers, acetal polymers and copolymers, acrylic polymers and copolyers, acrylonitrile/butadiene/styrene terpolymers, cellulose acetate, cellulose acetate butyrate, polycarbonates, polyethylene terephthalates, polystyrene, polyurethanes.polyethylenes and polypropylenes.

The mass-pigmented plastic may be in the form of chips or turnings and is conveniently the plastic wa'ste resulting from the trimming of injection moulded articles or from other moulding processes.

Other fillers which may be used include materials selected from glass and stone fragments and stone aggregate. The glass fragments may be colourless or coloured. The stone, either in the form of fragments or aggregate, may be used in its natural colour or it may be artificially coloured, for example, by the application of a dyestuff or pigment to the surface. A particularly preferred fragment is multicoloured calcined flint. Provided that the compositions which are obtained by using these artificially coloured materials are only lightly ground, the surface colouring remains essentially intact.

Colourless plastics fragments may also be used as the filler. By fragments or particles is meant those materials having a particle size not less than about 60 B.S. sieve size. These materials may be of rounded or angular shape.

S 35139 n t-J o l) The organic polyisocyanate which is used may be a simple polyisocyanate or it may be an isocyanate-terminated prepolymer obtained by the reaction of an excess of simple polyisocyanate with a hydroxyl- terminated polyether, polyester or polyesteramide.

As examples of polyisocyanates there may be mentioned aliphatic diisocyanates such as hexamethylene diisocyanate, tetramethylene diisocyanate, 2,2,4- and 2,4,4-trimethyl hexamethylene diisocyanates, aromatic diisocyanates such as tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3-methyldiphenyl methane-4,4'-diisocyanate, m- and p-phenylene diisocyanate, chlorophenylene-2,4-diisocyanate, xylylene diisocyanate, naphthalene-1,5-diisocyanate, diphenyl-4,4'-diisocyanate, 4,4'-diisocyanato-3,3'- dimethydiphenyl and diphenylether diisocyanate and cycloaliphatic diisocyanates such as dicyclohexylmethane diisocyanates,- methylcyclohexylene diisocyanate and 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate. Triisocyanates which may be used include aromatic triisocyanates such as 2,4,6-triisocyanato-toluene and triisocyanatodiphenyl ether. Examples of other suitable organic polyisocyanates include the reaction products of an excess of a diisocyanate with simple polyhydric alcohols such as ethylene glycol, 1,4- 1,3 and 2,3-butanediols, diethylene glycol, dipropylene glycol, pentamethylene glycol, hexamethylene glycol, neopentylene glycol, propylene glycol, glycerol, hexanetriols, trimethylolpropane, pentaerythritol and low molecular weight reaction products of the above polyols with ethylene oxide or propylene oxide.

There may also be used uretedione dimers and isocyanurate polymers of diisocyanates, for example, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate and mixtures thereof, and the biuret polyisocyanates obtained by the reaction of polyisocyanates with water.

S 35139 Mixtures of polyisocyanates may be used, including the mixtures obtained by the phosgenation of the mixed polyamines prepared by the reaction of formaldehyde with aromatic amines such as aniline and ortho-toluidine under acidic conditions. An example of the latter polyisocyanate mixture is that known as crude MDI, which is obtained by phosgenation of the mixed polyamines prepared by the reaction of formaldehyde with aniline in the presence of hydrochloric acid and which comprises diphenylmethane-4,4'-diisocyanate in admixture with isomers thereof and with methylene-linked polyphenyl polyisocyanates containing more than two isocyanate groups.

Examples of suitable hydroxyl-terminated polyesters and polyesteramides of use in the preparation of prepolymers (mixtures of polyesters and polyesteramides may be used if desired) are those obtained by known methods from carboxylic acids, glycols and, as necessary, minor proportions of diamines or aminoalcohols. Suitable dicarboxylic acids include succinic, glutaric, adipic, suberic, azelaic, sebacic, phthalic, isophthalic and terephthalic acids and mixtures of these. Examples of dihydric alcohols include ethylene glycol, 1:2-propylene glycol, l:3-butylene glycol, hexamethylene glycol, decamethylene glycol and 2:2-dimethyltrimethylene glycol. Suitable diamines or amino-alcohols include hexamethylene diamine, ethylene diamine, mono-ethanolamine and phenylenediamines. Small proportions of polyhydric alcohols such as glycerol or triinethylolpropane may also be used, in which case branched polyesters and polyesteramides are obtained. \ * As examples of hydroxyl terminated polyethers which may be reacted with an excess of an organic polyisocyanate as defined above to form a prepolymer there may be mentioned polymers and copolymers of cyclic oxides, for example l:2-alkylene oxides such as ethylene oxide, epichlorohydrin, 1:2-propylene oxide, l:2-butylene oxide and 2:3-butylene oxide, oxacyclobutane and substituted oxacyclobutanes and tetrahydrofuran. There may be mentioned polyethers obtained by the polymerisation of an alkylene oxide in the presence of a basic catalyst and water, glycol or a primary monoamine. Mixtures of such polyethers may be used.

S 35139 9 r5 J *v *) i Other prepolymers which may be used in the compositions of the present invention are those obtained by reacting a coal tar pitch which contains isocyanate-reactive groups with an excess of an organic polyisocyanate, for example, one or more of the organic polyisocyanates defined above, optionally together with an organic compound containing isocyanate-reactive groups such as the polyesters, polyesteramides and polyethers defined above.

In addition to the hydraulic cement, filler, water and polyisocyanate described above, the rapid curing cement compositions employed in the practice of the present invention will preferably include one or more isocyanate-reactive organic compounds.

The isocyanate-reactive organic compounds which may be employed include any of the hydroxyl-terminated polyethers, polyesters or polyesteramides disclosed above as being suitable for the preparation of isocyanate-terminated prepolymers and also the simple polyhydric alcohols containing from 2 to 6 carbon atoms and from 2 to 4 hydroxyl groups and the low molecular weight reaction products thereof with ethylene oxide or propylene oxide.

Further, other isocyanate-reactive organic compounds which may be used include aminoalcohols such as monoethanolamine, polyamines, such as ethylene diamine, hexamethylene diamine, m- and p-phenylene diamines and 2,4- and 2,6-diaminotoluenes, epoxy resins which also contain isocyanate-reactive groups, for example, the hydroxyl group-containing products obtained by reaction between diphenylolpropane and epichlorohydrin, drying oil and non-drying oil modified alkyl resins, castor oil, hydrogenated castor oil, urethane oils, which are the reaction products of diisocyanates with the alcoholysis products of the drying oil, for example, mono- or di-glycerides from linseed oil, and urethane alkyls, which are alkyl resins in the manufacture of which a part of the phthalic anhydride has been replaced by diisocyanate.

/V V.

S 35139 O 0 <, o A farther isocyanate-reactive resin whch may be present in the compositions of this invention is that obtained by the high temperature reaction of castor oil with a complex resin obtained by reacting together natural resin, glycerol and a resol resin at a high temperature. The castor oil and complex resin are typically reacted in the proportions from 95:5 to 20:80 parts by weight, at a temperature from 230 to 250°C for a time of from 1/2 to 2 hours. Typically, castor oil and the complex resin in the proportion of 4:1 by weight are heated together at a temperature of approximately 240°c for about 45 minutes. Conveniently, to prepare such a complex resin, natural resin (colophony), glycerol and the resol (which may be prepared by the condensation of 1 mole of diphenylolpropane with approximately 4 moles of formaldehyde under aqueous alkaline conditions at moderate temperatures) in the proportions of about 8.2:1.0 by weight are heated at a temperature of up to 275°C in an inert atmosphere until the acid value is less than 20mg KOH/g.

In addition water-soluble, isocyanate-reactive polymers can be used, such as derivatives of cellulose, for example, alkyl, hydroxyalkyl, carboxyalkyl and alkyl hydroxy alkyl ethers of cellulose such as methyl cellulose, ethyl cellulose, hydroxy ethyl cellulose, sodium carboxymethyl cellulose, methyl-hydroxypropyl cellulose, ethyl-hydroxypropylcellulose, ethyl-hydroxyethyl cellulose, methyl-hydroxyethyl cellulose and sodium methyl-carboxymethyl cellulose. There may also be used polyvinyl alcohols, polyoxyethylene glycols, the . e water-soluble polyoxyethylene/oxypropylene glycol block copolymers obtained by the addition of ethylene oxide to polyoxypropylene glycols (obtainable commercially under the name "Pluronic" (Registered Trade Mark)), low molecular weight initial stage condensation products or prepolymers of formaldehyde with melamine, urea, amides, carbamate, urons, ureins, ureides, imidazolidinones, pyrimidinones and triazinones and the lower alkyl ethers of such initial stage condensation products in which the alkyl groups contain from 1 to 3 carbon atoms, for example, methylated polymethylol melamine/urea, dimethylol and diethylol ethylene urea and dihydroxy dimethylol and diethylol ethylene urea S 35139 >- U I resin precondensates. There may also be used polyvinyl pyrrolidone and water-soluble addition products of ethylene oxide with fatty alcohols and alkyl phenols such as cetyl alcohol, oleyl alcohol and mixtures thereof, octyl phenol and nonyl phenol.

The compositions of this invention may further comprise an effective amount of polymerisation retardant which is a chain terminating compound such as a monohydric alcohol, a monocarboxylic acid or a compound containing at least one epoxy group.

As examples of monohydric alcohols which may be used in the compositions there may be mentioned methanol, ethanol, propanol, butanol, hexanol, isooctanol, nonanol, decanol, dodecanol and cetanol; unsaturated alcohols such as allyl alcohol and propargyl alcohol; and the polyether alcohols obtained by the interaction of alkylene oxides, for example, ethylene oxide and/or propylene oxide, with monohydric alcohols. Terpineols such as pine oil may also be employed.

Monocarboxylic acids which may be used in the compositions are, for example, the acids obtainable by oxidation of any of the above-mentioned monohydric alcohols which contain two or more carbon atoms, the mixed fatty acids derived from any of the oils mentioned below and also elaeostearic, linolenic, linoleic, oleic and stearic acids.

As examples of compounds which conta'in at least one epoxy group per molecule there may be mentioned epoxidised oils, such as those derived from rape seed, tobacco seed, soya bean, safflower, sunflower seed, grape seed, niger seed, poppy seed, hemp seed, candle nut, rubber seed, linseed, perilla, stillingia, chia, corophor, tung, oiticica, Japanese wood, poyok, soft lumbang, castor, dehydrated castor, tall and fish oil. There may be used the products obtained by first esterifying the mixed fatty acids, obtainable from the above-mentioned oils by saponification, with monohydric alcohols, diols or polyols of higher functionality and then epoxidising the S 35139 O 0 '• . o i.; mixed esters so obtained. As further examples of compounds containing epoxy groups which may be used in the compositions of the present invention there may be mentioned the bisepoxy compounds derived from diphenylolpropane and epichlorohydrin, as well as those which contain at least one epoxycyclohexane or epoxycyclopentane group. A further epoxy-compound which may be used is the product available commercially as "Cardura E", which is the glycidyl ester of the synthetic resin "Versatic 911" ("Cardura" and "Versatic" are Registered Trade Marks).

While the use thereof is not preferred due to possible leaching and immiscibility in the urethane sealant layer, the compositions of this invention may also comprise other minor amounts of plasticisers such as dibutyl phthalate, dinonyl phthalate, tricresyl phosphate, tritolyl phosphate, tri-(2-chloroethyl) phosphate and chlorinated hydrocarbons such as those sold under the name "Cereclor" (Registered Trade Mark).

If desired, the compositions according to the present invention may also contain bitumen (by which is meant the residue from the distillation of crude petroleum and which is essentially aliphatic in nature and substantially free from isocyanate-reactive groups), which in general improves flexibility and water resistance. Coal tar pitches may also be added to the compositions.

In general, although polyisocyanate and watep are present together in the compositions of this invention, foaming does not occur because the cement is present in sufficient amount and is basic enought to absorb the carbon dioxide which is liberated when isocyanates react with water. Should the composition be such that it has a tendency to foam, then this tendency can be minimised by incorporating in the composition an effective amount of an antifoaming agent, such as a basic compound of a metal selected from Groups I to IV inclusive of the Periodic Table (as set out on the inside back cover of the book "Advanced Inorganic Chemistry" by S 35139 0 0 •'. r- ' »- ' J •- ' j .

Cotton and Wilkinson, 2nd Edition published 1966 by Interscience Publishers.) Such basic compounds may be oxides, hydroxides, basic salts, complex salts or double salts of metals and as examples there may be mentioned calcium oxide, magnesium oxide, barium oxide, sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, cadmium hydroxide, calcium silicate, barium silicate, sodium silicate, lead hydroxide and basic lead acetate. Other antifoaming agents which may be employed include siloxanes such as poly(siloxane), poly(alkylsiloxanes) and poly(dialkylsiloxanes).

The compositions may also contain, in appropriate circumstances, an effective amount of accelerator compounds which are known to increase the rate of reaction between isocyanate groups and hydroxyl groups. Suitable accelerator compounds include, for example, organometallic compounds, metal salts and tertiary amines, specific examples of which are dibutyl tin dilaurat-e, tetrabutyl titanate, zinc octoate, zinc naphthenate, stannous octoate, stannic chloride, ferric chloride, lead octoate, potassium oleate, cobalt 2-ethylhexoate, N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, N-ethylmorpholine, 1,4-diazabicyclo-2,2,2-octane, 4-dimethylaminopyridine and oxypropylated triethanolamines, beta-diethylaminoethanol and N,N,N',N'-tetrakis (2-hydroxypropyl) ethylenediamine.

There may also be used volatile organic solvents of the kind which are conventionally used in the"formulation of polyurethane products, such solvents being inert towards isocyanate and hydroxyl groups. Suitable solvents include esters, ketones, hydrocarbons and halogenated hydrocarbons. Specific solvents which may be used are methyl ethyl ketone, methyl isobutyl ketone, 4-methyl-4-methoxypentan-2-one, ethyl acetate, butyl acetate, ethoxyethyl acetate, cyclohexanone, toluene and xylene. It is preferred not to use such volatile solvents because they add to the cost of the compositions, cause pollution of. the atmosphere and may give rise to a flammability hazard. -14- S 35139 i-i^ivuOi A wide variation in the proportions of the different ingredients of the compostions employed in the practice of this invention may be employed. Generally, such compositions will contain from 5 to 500 parts by weight of water, from 10 to 10,000 parts by weight of filler, from 5 to 5000 parts by weight of polyisocyanate and from 5 to 4,000 parts by weight of aromatic phthalate plasticiser per 100 parts by weight of cement. Preferably, such compositions will contain from 10 to 100 parts by weight of water, from 25 to 5000 parts by weight of filler, from 10 to 500 parts by weight of polyisocyanate and from 10 to 3,000 parts by weight of aromatic phthalate plasticiser per 100 parts by weight of cement. When an isocyanate-reactive organic compound is present, such compound is typically present at between 5 and 500 parts by weight, and is preferably present at between 10 and 250 parts by weight, per 100 parts by weight of cement.

The compositions of this invention ar& typically applied by first mixing all of the ingredients, utilizing means well known to those of skill in the art such as cement mixers, forced paddling mixers and the like until a satisfactory blend is obtained. The blended composition may then be applied to form a surface by any means typically employed for the application of cement compositions, such as troweling, pouring, spraying and the like, as appropriate.

The compositions may be treated by any method. Typically by grinding, which will expose the participate filler and*leave an even surface. Such treatment may either be done before or after the composition has set.

The urethane-forming sealant layer may be applied by any conventional means which means are well known to those of skill in the art.

The invention is illustrated by the following Examples which are presented for illustrative purpose only and are not intended to limit the scope of the invention in any manner whatsoever. In such Examples, all reference to "parts" refers to parts by weight.

S 35139 y ') <. i— '■ i O o <.5 Example 1 100 parts of Portland cement, 75 parts of sand (30 - 200 BS sieve-size; 0.05 - 0.0076 cm in diameter) and 225 parts of crushed blue flint are blended together and added to a mixture of 75 parts crude MDI (containing approximately 502 by weight of diphenylmethane-4,4'-diisocyanate, the remainder being isomers thereof and methylene-linked polyphenyl polyisocyanates containing more than two isocyanate groups), 37.5 parts castor oil rosinate (provided as described below), 18 parts of water and 15 parts of butyl benzyl phthalate. This mixture is further blended until an even dispersion is obtained.

The dispersion is spread to form a flooring surface and the surface wet ground to expose the aggregate. After setting for 24 hours the surface is coated with a 40% solution in 1:1 mixture of ethylene glycol acetate: xylene of a moisture-durable one component polyurethane prepolymer. Upon curing of this sealant lays a flooring having an enhanced Terrazzo-type appearance is produced.

The castor oil/rosin based product used in this Example is obtained by heating 320 parts of 1st pressings castor oil together with 80 parts of an esterified resin modified phenol formaldehyde resol resin at 240°C for 45 minutes. This latter component is obtained by heating together natural rtfsin, glycerol and the condensation products of diphenylolpropane with approximately 4 moles of formaldehyde in the proportions 8.2:1.1:1.0 by weight at 275°C until the acid value of the material is less than 20 mg KOH/kg.

Comparative Experiment A The procedure of Example 1 is repeated except that the butyl benzyl phthalate is replaced with 15 parts of dibutyl phthalate. The appearance of the Terrazzo-type floor is marred due to the extraction of the dibutyl phthalate by the xylene in the urethane sealant mixture.

S 35139 9 0 <. r; t.j ^; Example 2 225 parts of crushed blue flint are adhered to a flooring surface. These fragments are filled with a grouting composition formed by blending 100 parts of Portland cement, 75 parts of sand (30 - 200 BS sieve-size; 0.05-0.0076 cm in diameter), 75 parts crude MDI, 18 parts water, 15 parts of butyl benzyl phthalate and 30 parts of oxypropylated glycerol (having a hydroxyl value of 160). The surface is wet ground to expose the aggregate.

The surface is allowed to set for 24 hours and is then coated with a 40 X solution in 1:1 mixture of ethylene glycol acetate : xylene of a moisture-curable one-component polyurethane prepolymer. Upon curing of the sealant layer, a flooring having an enhanced Terrazzo-type appearance is produced.

Comparative Experiment B The procedure of Example 2 is repeated except that the butyl benzyl phthalate is replaced with 15 parts of dibutyl phthalate. The appearance of the Terrazzo-type floor is marred due to the extraction of the dibutyl phthalate by the xylene in the urethane sealant mixture. .

Example 3 The procedure of Example 2 is repeated except that the butyl benzyl phthalate is replaced with 15 parts of dibenzyl phthalate. Upon curing of the sealant layer, a flooring having an enhanced Terrazzo-type appearance is produced.

S 35139 Extraction Test A dispersion was prepared using the procedure of Example 1. This dispersion was poured into a mould of size 38mm cube and allowed to set. After setting over a period of 24 hours, cubes of 38mm size on each edge were removed from each mould.

The foregoing process was repeated omitting butyl benzyl phthalate from the mixture. The foregoing process was also repeated except that the butyl benzyl phthalate was replaced either by 15 parts of 2-ethylhexyl benzyl phthalate or 15 parts of dibutyl phthalate.

The cubes formed were subjected to an extraction test by immersing one cube in 100cm of xylene. After an immersion period of 28 days at ambient temperature (about 20°C), each cube was removed from the xylene in which it had been immersed. The xylene was carefully evaporated to dryness at 50°C over a period of four hours. The weight of the residue was determined and this is recorded in the following table. | phthalate Weight of residue (g) | | NIL 0.1 | | Butyl benzyl phthalate 0.1 | | 2-ethylhexyl benzyl phthalate 0.6 | | dibutyl phthalate 2.3 | It will be observed that when the phthalate is dibutyl phthalate, the weight of the resiude is considerably greater than that of the residue from compositions containing either 2-ethylhexylbenzylphthalate or butyl benzyl phthalate. It will also be observed that the weight of residue is the same when using butyl benzyl phthalate as for the composition which contains no phthalate.

S 35139 9 O/.r- tJ <.

Claims (23)

WHAT WE CLAIM IS:

1. A method for providing a decorative surface comprising the steps of: a) applying to the area to be surfaced a coating composition comprising: (i) an hydraulic cement; (ii) a filler in the form of fragments or coarse particles; (iii) water; (iv) an organic polyisocyanate; and (v) an aromatic phthalate plasticiser; b) treating the surface of the composition to expose the fragments or particles of filler; and c) applying a layer of a liquid polyurethane-forming composition over the treated surface of step (b).

2. A method in accordance with Claim 1 wherein said coating composition further comprises an isocyanate-reactive organic compound.

3. A method in accordance with Claim 1 or Claim 2 wherein said aromatic phthalate compound has the structural formula 0 0 wherein R is C7-C12 arylalkyl; or ^ arylalkyl substituted on the aryl ring with methyl or halogen; and R* is Cy-C12 arylalkyl; C7"C12 arylalkyl substituted on the aryl ring with methyl or halogen; or - V" " C1"C18 aikyi. c.\ -19- S 35139 9 < • ■- <■ tJvl

A method in accordance with Claim 3 wherein R is C^-C^g arylalkyl and R' is C^-C^ alkyl.

A method in accordance with Claim 4 wherein R is benzyl and R" is VC10 alk3r1'

A method in accordance with Claim 4 wherein said aromatic phthalate plasticiser is butyl benzyl phthalate.

A method in accordance with any one of the preceding Claims wherein the hydraulic cement is selected from Portland cement, rapid hardening cements, low-heat cement, sulphate-resisting cements, Portland blast furnace cement, masonry cements, natural cements, lime cements, selenitic cements, Pozzolanic cement, and calcium sulphate cements.

A method in accordance with any one of the preceding Claims wherein there are used 5 - 5000 parts by weight of water, 10 - 10,000 parts by weight of filler, 5 - 4,000 parts by weight of aromatic phthalate plasticiser, 5 - 500 parts by weight of isocyanate-reactive organic compound and 5 - 5,000 parts by weight of polyisocyanate per 100 parts by weight of cement.

A method in accordance with Claim 8 wherein there are used 10 - 100 parts by weight of water, 25 - 5,000 parts by weight of filler, 10 - 3,000 parts by weight o.f aromatic phth%late plasticiser, 10 - 250 parts by weight, of isocyanate-reactive organic compound and 10 - 500 parts by weight of polyisocyanate per 100 parts by weight of cement.

A method in accordance with any one of the preceding Claims including a preliminary step of bonding fragments of material to the area to be surfaced, whereafter the application of the coating composition over the bonded fragments fills in the gaps.between them as a grouting composition. , ■' -20- S 35139

11. A curable composition which comprises (i) an hydraulic cement; (ii) a particulate filler; (iii) water; (iv) an organic polyisocyanate ; and (v) an aromatic phthalate plasticiser.

A composition in accordance with Claim 11 wherein said coating composition further comprises an isocyanate-reactive organic compound.

A composition in accordance with Claim 11 or Claim 12 wherein said aromatic phthalate compound has the structural formula; wherein R is C7-C12 arylalkyl; or Cy-C^ arylalkyl substituted on the aryl ring with methyl or halogen; and R'is C7"C12 arylalkyl, C7"^12 aryIalkyl substituted on the aryl ring with methyl or halogen, or alkyl.

A method in accordance with claim 13 wherein R is C7-C1Q arylalkyl and R' is C^-C12 alkyl. 0 0 -21- S 35139 o n i ^ 0 o . r- r-

15. A composition in accordance with Claim 14 wherein R is benzyl and R* is c6-cio alkyi-

16. A composition in accordance with Claim 14 wherein said aromatic phthalate plasticiser is butyl benzyl phthalate.

17. A composition in accordance with any one of Claims 11 to 16 wherein the hydraulic cement is selected from Portland cement, rapid hardening cements, low-heat cements, sulphate-resisting cements, Portland blast furnace cement, masonry cements, natural cements, lime cements, selenitic cements, Pozzolanic cement, and calcium sulphate cements.

18. & composition in accordance with any one of Claims 11 to 17 wherein there are used 5 - 500 parts by weight of water, 10 - 10,000 parts by weight of filler, 5 - 4,000 parts by weight of aromatic phthalate plasticiser, 5 - 500 parts by weight of isocyanate-reactive organic compound and 5 - 5,000 parts by weight of polyisocyanate per 100 parts by weight of cement.

19. A composition in accordance with Claim 18 wherein there are used 10 - 100 parts by weight of water, 25 - 5,000 parts by ^ weight of filler, 10 - 3,000 parts by weight of aromatic phthalate plasticiser, 10 - 250 parts by weight of isocyanate-reactive organic compound and 10 - 500 parts by weight of polyisocyanate, per 100 parts by weight of cement.

20. A decorative surface produced by a method in accordance with any \^J one of Claims 1 to 10 or by means of a composition according to any one of Claims 11 to 19.

21. A method as defined in claim 1 substantially as herein described with reference to any example thereof.

22. A curable composition as defined in claim 11 substantially as herein described with reference to any example thereof.

23. A decorative surfaoe' *&s;-,defined in claim 20 substantially as herein described with reference-to--, any example thereof. By>HS/The!r authorised Agent A .i. PARK & SON