Coating compositions

A solid preparation from which a reconstituted emulsion bright-drying optionally rebuffable floor finish containing emulsion polymer, alkali-dispersible wax and optionally an alkali-soluble resin in dry particulate form which may be obtained by dehydration of an aqueous dispersion of the emulsion polymer, the wax and optionally the alkali-soluble resin at a temperature below the minimum film-forming temperature of the composition.

This invention relates to coating compositions and methods of making them, 
more particularly to dehydrated compositions containing emulsion polymers 
that are reconstitutable to aqueous dispersions. 
In the fields of decorative and protective coating, extensive use is made 
of aqueous polymers latices, produced by emulsion polymerisation, as major 
film-forming ingredient in both permanent and temporary organo-coatings 
including certain floor coatings. 
Polymers and copolymers produced by emulsion polymerisation are known as 
"emulsion polymers". 
Typical aqueous coating compositions contain many additional ingredients. 
Thus in the formulation of paints pigments, extenders, suspending agents, 
stabilisers, levelling agents, plasticisers and emulsifiers may be used; 
in cleaning compositions detergents including detergent salts and builders 
are used; and in emulsion polish compositions, such as are used for floor 
care waxes, there may be included, for example, alkali-soluble resins, 
surfactants, fugitive and non-fugitive plasticisers. 
Frequently, polymer latex is manufactured at one site then transported to 
another where it is subsequently formulated into a coating composition. 
Quality control problems arise, often through environmental changes during 
the transportation of the latex. Moreover transportation costs are high 
and since polymer latices are frequently produced at a solids content 
level of up to 50%, frequently 10-25%, the net result is the expensive 
transportation of water. It has now been found that certain latices may be 
dehydrated for subsequent rehydration and recovery of useful dispersions. 
Accordingly, in one aspect, the present invention comprises a method of at 
least partially dehydrating a composition containing a polymeric material 
latex at a temperature less than the minimum film forming temperature, 
hereinafter referred to as MFT, characteristic of the composition. 
Preferably the composition containing the polymer latex is dehydrated to a 
solid, especially a particulate form. The invention may be employed for 
concentrating latices to reduce their water-content provided that the 
emulsion is not "broken", that is so that coagulation or coalescence does 
not occur during drying. 
Dehydration may be effected by simple exposure of an aqueous composition 
containing polymer latex to drying conditions provided that the 
temperature does not rise above the MFT of the composition. If during 
dehydration the temperature of the latex or dehydrate is allowed to rise 
above the characteristic MFT, a sticky product can then result frequently 
presenting handling problems and difficulties may be experienced in 
redispersing the dehydrate. After total dehydration of a latex en masse a 
more or less hard cake or product results which may be broken up and 
powdered for redispersion. Whilst any suitable means of drying (such as 
air-drying, freeze-drying, oven-drying) may be employed it is preferred to 
employ the technique known as spray-drying. 
Spray-drying has the advantage of relatively low cost (contrast 
freeze-drying) and speed. Moreover when properly adjusted the hot gas 
stream, used for drying, does not raise the temperature of droplets of 
latex or dehydrate particles to above the MFT. It seems that the presence 
of evaporating water moderates temperature increase until dehydration is 
complete, by which time the particles are translated away from exposure to 
relatively hot incoming air. 
It is possible in certain apparatus to spray-dry whilst simultaneously 
coating onto an existing particulate solid material contained in a 
fluidised bed within the spray-drying apparatus. Using apparatus of this 
kind it is possible to apply polymeric materials onto solid substrates 
such as for example, alkaline materials exemplified by carbonate, 
bicarbonate, phosphate or silicate salts of ammonium, sodium or potassium, 
and the like. This method may be conveniently employed when for example, a 
particulate cleaning composition is to be prepared comprising one or more 
detergent salts and suitable polymeric materials. The intention with such 
compositions is to disperse the dry particles in water and apply the 
so-formed dispersion to a surface to be cleaned with an applicator. 
Cleaning occurs through the action of the detergent salts component, soil 
being removed in the applicator. Upon drying, a shine, due to the residual 
polymeric material coating the surface, remains after final air-drying. 
In another aspect the present invention comprises dehydration products from 
emulsion compositions containing polymer latices as well as the 
reconstituted latices and compositions preparable therefrom. 
The starting material for dehydration may be copolymer latices or 
formulated coating compositions containing such latices. Valuable 
dehydrates may be obtained with emulsion copolymers of lower 
.alpha..beta.-ethylenically unsaturated monocarboxylic acids such as 
acrylic, methacrylic, crotonic and such acids as itaconic acid which are 
usually used in admixture and may be modified by incorporating other 
monomers or by blending with other polymers. The polymer latices are 
produced via emulsion polymerisation which may be conducted in a single 
step using a homogeneous blend of monomers, or in a polyphase 
polymerisation in which the polymerisation of a group of monomers is 
interrupted and a further group of monomers is added and polymerised and 
so on, resulting in either a "blend" of polymeric types of a "core" 
polymer depending on the precise conditions of reaction as is well known. 
It is not essential that the carboxyl groups be located externally of the 
individual polymer particles, for example, in the case of "core" polymers. 
Preferred polymeric materials have a relatively high carboxyl content, that 
is free - COOH groups, or such groups neutralised by salt formation. 
Preferably the carboxylated copolymers contain at least 6% w/w of acid 
based on monomer mix. So far it has not been practicable to produce an 
emulsion polymer via emulsion polymerisation that contains more than about 
35% w/w acid. 
It has been found that low acid-content copolymers lead to dehydrates that 
redisperse unsatisfactorily. At an acid-content level of about 3% some 
redispersion occurs but insufficient for convenience. 
Broadly speaking the acid value of polymers and copolymers suitable for use 
in the present invention will lie in the range 30 to 230 preferably 39 to 
228 which ranges respectively approximately correspond with an acid 
content, expressed as acrylic acid, of 3.8 to 29.5% w/w and 5.0 to 29.2% 
w/w. 
Other monomers that may be copolymerised with the 
.alpha..beta.-ethylenically unsaturated monocarboxylic acids are 
typically:- styrene; substituted styrenes such as .alpha.-methyl styrene 
and halogenated styrenes; lower alkyl methacrylate esters and/or 
acrylonitrile which modify the final copolymer by increasing its hardness; 
higher alkyl acrylates from alcohols containing up to 12 carbon atoms in 
straight or branched chains and cyclic alcohols; alkyl methacrylates from 
alcohols containing up to 12 carbon atoms notably butyl- and 2-ethylhexyl 
methacrylate which act by way of internal plasticisers modifying the 
hardness and filmforming properties of the final copolymer: hydroxylates; 
acrylamides for example methylol acrylamide; epoxidated monomers such as 
glycidyl acrylate and -methacrylate; aminoalcohol acrylate such as 
dimethylaminoethanol acrylate; divinyl benzene. These comonomers may be 
added singly or in combination at levels often less than 0.1 w/w of total 
monomer mix up to about 15% w/w impart special properties to the final 
copolymer, for example to improve intercoat adhesion, adhesion to 
substrates: self gloss, durability, detergent resistance and resistance to 
rubber heel marking. 
Conveniently the carboxylated copolymer is "metallised" that is the latex 
includes a polyvalent metal salt in solution which is believed to cause 
"reversible" cross-linking between polymer molecules upon drying out of 
the latex. By "reversible" is meant that under certain conditions 
cross-linking occurs, for example upon a film drying out, but by changing 
the pH conditions, for example by addition of an aqueous base, such as 
ammonia and aliphatic amines or their salts, to or on an applied dried 
coating the cross-linkages may be broken. Only in the cross-linked 
condition is the polymer insensitive to water and detergent. Such 
metallised latices are well known especially in the field of floor 
maintenance where the latices are utilised in floor coating compositions 
for their water- and detergent- resistance coupled with ease of removal 
when desired. Suitable metal ions derive from magnesium, calcium, 
strontium, chromium, maganese, iron, cobalt, nickel, copper, zinc, 
zirconium and tin, preferably zinc. 
To achieve a good dehydrate it is important that the MFT of the composition 
containing the emulsion polymer and other components, for example, wax be 
above ambient temperature, that is greater than 15.degree. C. and 
preferably in the range of 20.degree. C. to 80.degree. C. 
Good dehydrates are achieved when the MFT of the copolymer included in a 
coating composition is greater than 15.degree. C. and preferably in the 
range of 20.degree. to 80.degree. C. 
An important factor influencing MFT and solubility, hence redispersibility, 
of polymeric materials, apart from the selection of the precise chemical 
profile for monomers in a copolymer, is molecular weight. To some extent 
molecular weight may be controlled during polymerisation by the use of 
chain transfer agents, such as the halogenated hydrocarbons like carbon 
tetrachloride and carbon tetrabromide, and mercaptans such as `tert` 
-dodecyl mercaptan. Mean molecular weight values may be estimated from 
viscosity characteristics measured with the Ostwald viscometer using 
standardised solutions of polymeric material in organic solvents for 
comparison. 
The present invention has been found to be applicable to the dehydration of 
latices containing both high and low molecular weight polymers and 
copolymers. Redispersion is favoured with polymers of relatively low 
molecular weight. Those versed in the art of formulating floor polishes 
will appreciate that an alkali-soluble resin component, needed to optimise 
gloss and levelling, may be exemplified by a copolymer prepared from some 
of the abovementioned monomers. In which case the molecular weight is 
necessarily low to achieve the desired solubility in alkali. 
In greater detail emulsion floor polish compositions, which may be 
pigmented or unpigmented, have solids content of about 8% minimum and 
typically contain one or more of the following component types: 
(i) metallised copolymer emulsion, 
(ii) non-fugitive plasticiser, 
(iii) coalescent solvents or fugitive plasticiser, 
(iv) surface active agents, 
(v) water-dispersed wax, 
(vi) dissolved alkali-soluble resin. 
The invention also relates to the preparation of coating compositions from 
dehydrated compositions containing emulsion polymers, especially 
metallised emulsion polymers by dispersing dehydrate in water containing a 
suitable base and optionally plasticiser ingredient. Dehydrated 
compositions containing polymeric materials and any or all of the above 
component types save coalescent solvent may be prepared by redispersing 
dehydrate in water containing a suitable base and where desired, a 
plasticiser ingredient. the polymeric material has acid content greater 
than 6% w/w preferably greater than 10% and especially 20-25% w/w based on 
total weight of monomer mixture used to form the emulsion polymer in the 
dehydrate composition. Preferably the polymer is "metallised" for this 
enhances redispersion as an emulsion. 
To prepare a dehydrate which is capable of protracted storage from a polish 
formulation it is important that the coalescent solvent, examples of which 
are diethyleneglycol monomethylether or monoethyl ether and fugitive 
plasticisers be omitted. Still retaining these two conponent types, a 
product can be achieved with adequate coating properties for some purposes 
upon reconstitution, for example, by use of a powder form of coalescent 
solvent or coalescent aid such as caprolactam; difficulty may be 
experienced in reconstituting becuse of the sticky nature occurring or 
developing in such dehydrate after standing some time. 
Reconstituted emulsion polish compositions completely lacking coalescent 
solvent may be employed for renovating purposes upon a previously coated 
floor. In such application the formulation needs to be such that the MFT 
of the composition as a whole is exceeded during a final buffing step 
which usually attains a minimum of 28.degree. C. on the floor, after 
application and during drying in situ. It is stressed that in these 
circumstances no coalescent solvent is necessary. 
Such a composition has the advantage that if sprayed onto furniture or 
drapes and/or carpet, the composition dries to a powder which may be 
simply dusted off or brushed off as any other dusty material. In use the 
process, which is variously known as "spray-buffing", "spray-polishing" or 
"speed-polishing", involves applying, as by spraying, a wet coating onto a 
floor and before the coating has dried, buffing with a high-speed 
polishing machine to provide a finish which is a dry, hard, glossy surface 
often with a mirror-like appearance. The process obviates frequent 
stripping of the substrate and polishing brushes do not soil rapidly with 
a composition containing no coalescent solvent. 
Essentially, the compositions designed for such a purpose actually contain 
insufficient plasticiser and/or coalescent solvent to render the 
composition, as a whole, film-forming at the relatively low temperatures 
experienced at floor level. Whilst there is a requirement for a minimum 
concentration of plasticiser, the coalescent solvent component need not be 
present in such conpositions. 
Any or all of the remaining components may be included although wax 
concentration is generally at below 20% and preferably less than 15% by 
weight of total composition. Reconstitution is effected by dispersing, 
through stirring, an appropriate amount of the dehydrate in powder form 
into water containing fugitive plasticisers and/or coalescent solvents if 
needed together with a basic material. Suitable bases are, for example, 
ammonium hydroxide, ammonium carbonate, morpholine, diisopropylamine, 
3-methoxy-propylamine, 2-amino-2-methyl-propan-1-ol, ethylene diamine and 
the like customarily used in emulsion polishes. 
A particularly useful range of bases are the so-called carbonates or 
carbamates of organic amines. These are the material forming a crust that 
sometimes surrounds the stopper of bottles containing amines in storage 
places. 
Such materials may be prepared by interacting free amine and carbon dioxide 
for example in solid form. 
The amine carbonates or carbamates being solids may be mixed as such into 
dehydrated polish composition for transportation so that reconstitution 
does not necessitate separate addition of base. 
The rate of redispersion depends upon the temperature of the mixing, 
paticle size of the dehydrate and the desired concentration, that is 
solids content, of the final dispersion.

The following are some non-limitative examples which save for Examples 1, 2 
and 3 further illustrate the invention; Examples 1, 2 and 3 serve to 
illustrate the method of carrying out some aspects of the invention and 
the preparation of some starting materials. 
EXAMPLE 1 
36% solids content copolymer latices A, B, C and D were prepared in 
conventional apparatus by emulsion polymerisation at atmospheric pressure. 
2.8% w/w dodecylated oxydibenzene disulphonate sodium salt was used as 
anionic surfactant and 1% w/w ammonium persulphate was used as free 
radical initiator. The compositions of A, B, C and D are shown in Table 1 
Table 1 
__________________________________________________________________________ 
Compositions of monomer mix 
Percentage w/w 
MFT.degree. C. of 
Parts w/w per 100 parts mixture 
on total monomer 
metallised 
Polymer 
MAA MMA BA STY 
GM TDM polymer 
__________________________________________________________________________ 
A 12 39 29 20 -- 0.75 59 
B 12 59 29 -- -- 1.75 50 
C 12 58 29 -- 1 1.75 49 
D 12 48 40 -- -- 1.50 43 
__________________________________________________________________________ 
Legend: 
MAA = Methacrylic acid 
MMA = Methyl methacrylate 
BA = Butyl acrylate 
STY = Styrene 
GM = Glycidyl methacrylate 
TDM = `ert`-dodecyl mercaptan, a chain transfer agent for control of 
molecular weight 
The dispersions of emulsion polymers A, B, C and D were obtained as acidic 
bluish white, mobile fluids, containing less than 0.2 w/w unreacted 
monomer. 
Each of the emulsion polymers was "metallised" by mixing with 25.170 parts 
zinc ammonium acetate solution per 100 parts dispersion. The zinc ammonium 
acetate solution was prepared by mixing 2.101 parts zinc acetate 
dihydrate, 2.166 parts aqueous ammonium hydroxide (S.G. 0.880), 0.614 
parts nonyl phenyl polyethoxyethanol in 15.299 parts water. This provides 
for roughly 50% of the free carboxyl group to be "metallised" or 
cross-linked. 
Finally the dispersions were adjusted to 30% solids content and pH 7.8-8.8. 
No separation of phases was observed on centrifuging at 4000 r.p.m. for 10 
minutes. 
The emulsion polymer dispersions so produced were air-dried on shallow 
trays at a temperature of below the MFT of the metallised emulsion 
polymer. Virtually odourless, hard cakes were produced and on crushing to 
pass a 100 mesh (BS410) sieve became white powders. 
The dried products when stirred with water alone do not disperse or 
emulsify, illustrated by the fact that two phases are readily separable. 
Raising the pH of the mixtures to above 7.8 by addition of ammonium 
hydroxide solution results in bluish white dispersions exhibiting no 
separation on centrifuging at 4000 r.p.m. for 10 minutes. 
EXAMPLE 2 
The emulsion polymer dispersions prepared in Example 1 were introduced into 
a NIRO ATOMISER spray drying unit supplied by the Niro Company of Denmark 
operating under the following conditions. 
Air (inlet) temperture 200.degree. C. 
Air (outlet) temperature 70.degree. C. 
Atomiser speed 60,000 r.p.m. 
By this method extremely fine particle size powders were produced estimated 
at between 1 and 8 microns mean particle size. 
The products when stirred with water alone do not disperse or emulsify, 
illustrated by the fact that the two phases are readily separable. Raising 
the pH of the mixtures to 7.8 by addition of ammonium hydroxide solution 
results in bluish white dispersions exhibiting no separation on 
centrifuging at 4000 r.p.m. for 10 minutes. 
EXAMPLE 3 
A coating composition was prepared using the dried emulsion polymer A from 
Example 1. 78.79 parts water, 4 parts diethylene glycol monomethyl ether 
and 0.5 parts of 0.880 ammonium hydroxide were stirred while adding 13.13 
parts of the powder over 20 minutes. After stirring for a further 10 
minutes period 0.79 dibutyl phthalate and 0.79 parts tributoxyethyl 
phosphate were added. Stirring was continued until complete redispersion 
of the ingredients was obtained. This could be detected by examination of 
the dispersion on a black Test card for signs of bittiness and also by 
centrifuging a small portion at 4000 r.p.m. for 10 minutes. After stirring 
the dispersion for a total of one hour no signs of bittiness or separation 
after centrifuging was noted. 
The dispersion when coated onto a test card dried to a glossy, water 
resistant, flexible polymeric coating. 
EXAMPLE 4 
A dispersion of an intermediate molecular weight oxidised polyethylene wax 
was prepared by the following procedure: 
Using a pressure emulsification vessel at 150.degree. C. a mixture of 
19.455 parts polyethylene wax AC 392, (Trademark of Allied Chemical 
Corporation), 4.864 parts Lissapol NXP, a synthetic nonionic detergent 
marketed by Imperial Chemical Industries Limited and described as a 
nonylphenolethene oxide condensate (or Synperonic NP10 - another Trademark 
of Imperial Chemical Industries Limited for "Lissapol NXP") 0.468 parts 
potassium hydroxide, 0.195 parts sodium metabisulphite and 46.429 parts 
softened water was stirred for one hour. The emulsion was cooled to give a 
stable dispersion of total-solids content pf 35%. 
This dispersion was mixed with metallised polymer B shown in Table 1 in the 
following ratio: 
Polymer dispersion 139.9 
Wax dispersion 22.5 
The polymer/wax dispersion had a solids content of 30.69%, pH 7.8 and MFT 
44.degree. C. 
The dispersion was spray dried using the conditions described in Example 2 
to give a fine, white powder. 
Using the method described in Example 3 the powder was redispersed to give 
a fine particle size, stable emulsion. 
A 2.0 thousands of an inch wet thickness film was cast on to a glass panel 
to give a clear, tough, water-resistant film on drying. The presence of 
the wax component improved the scratch resistance of the coating film. 
EXAMPLE 5 
A dispersion of low molecular weight oxidised polyethylene wax was prepared 
by the following procedure: 
Using a pressure emulsification vessel at 140.degree. C. a mixture of 
19.455 parts polyethylene wax AC 540, (a Trademark of Allied Chemical 
Corporation), an emulsifiable ehtylene copolymer 4.864 parts Lissapol NXP, 
(or Sunperonic NP10, A Trademark of Imperial Chemical Industries Limited), 
0.486 parts potassium hydroxide, 0.195 parts sodium metabisulphite and 
46.429 parts softened water was stirred for one hour. The emulsion was 
cooled to give a stable dispersion of total solids content of 35%. 
The dispersion was formulated into a coating composition using the 
following recipe: 
Metallised Polymer dispersion (B, Table 1): 188.5 parts 
AC 540 wax dispersion: 30.3 parts 
Tributoxyethyl Phosphate: 4.6 parts 
Fluorocarbon Surfactant: 0.035 parts 
The dispersion was then spray dried on a NIRO Atomiser unit fitted with an 
Air Broom assembly. The inlet temperature was 185.degree. C. and the 
outlet temperature 70.degree. C. A fine white powder was collected. 
Separate portions of the powder were mixed with the following alkaline 
substances 
(i) Ammonium hydroxide (SG 0.880) 
(ii) Ethylene diamine 
(iii) Ammonium carbonate and dispersed by stirring into water to give a 
final total solids content of 10% by weight and a final pH of 8.3-9.2. The 
dispersions showed no separation after centrifuging for 10 minutes at 4000 
r.p.m. 
The emulsions were used for the routine maintenance of previously 
trafficked floor substrates such as vinyl, linoleum, vinyl asbestos and 
sealed wood by the process known as "Spray Cleaning". In this process a 
film of the emulsion is sprayed on the floor and then immediately 
burnished to a shine using a floor polishing machine. 
EXAMPLE 6 
Two alkali-soluble resin solutions were prepared as follows: 
(a) Heat and stir at 55.degree. C. a mixture of 2.35 parts ammonium 
hydroxide solution (SG 0.88) and softened water (80.3 parts) in a vessel. 
Add 15 parts modified styrene maleic anhydride resin (SMA 17352A - A 
Trademark of Atlantic Richfield Corporation) over 15 mins and then further 
2.35 parts ammonium hydroxide solution. A clear solution of 15% solids is 
obtained after cooling. 
(b) Heat and stir at 80.degree. C. a mixture of 2.75 parts ammonium 
hydroxide solution (SG 0.88) and 72.5 parts softened water in a vessel. 
Add 22 parts of a rosin based resin SR88, a Trade Mark of Schenectady, 
over 15 minutes and then a further 2.75 parts ammonium hydroxide. A clear 
solution of 22% solids is obtained after cooling. 
Using these resin solutions a series of dispersions utilizing the wax and 
metallised polymer dispersion previously described were prepared by 
mixing. The compositions are shown in Table 2. 
Two series of powders were prepared by (1) drying the dispersions on trays 
below their MFT's and (2) by spray drying the dispersions in a NIRO spray 
drying unit (supplied by the Niro Company of Denmark). 
The theoretical composition of the powders excluding the excess of zinc 
salt emulsifiers present in the metallised polymer and wax dispersion is: 
zinc metallised polymer: 82.686% 
Polyethylene wax: 12.937% 
alkali-soluble resin: 4.311% 
flourocarbon surfactant: 0.066% 
The powders were redispersed in alkaline medium to a level of 15% total 
solids using the following formulation: 
______________________________________ 
Powder 14 parts by weight 
Dipropylene glycol monomethyl 
2.132 parts by weight 
ether 
Diethylene glycol monomethyl 
2.132 parts by weight 
ether 
Diethylene glycol monomethyl 
2.132 parts by weight 
ether 
Dibutyl phthalate 0.842 parts by weight 
Tributoxyethyl phosphate 
0.842 parts by weight 
Ethylene diamine 0.800 parts by weight 
Softened water 83.812 parts by weight 
TOTAL 104.560 
______________________________________ 
The method of dispersion conprised stirring at 50.degree. C. a mixture of 
the water, ethylene diamine, dipropylene glycol monomethyl ether, 
diethylene glycol monomethyl ether and then adding over 45minutes the 
powder. After stirring for a further 30 minutes and then cooling a stable 
dispersion was obtained. This showed no separation on centrifuging. 
The coatings were applied in the normal manner to flooring substrates such 
as vinyl and vinyl asbestos tiles and assessed for gloss, levelling, 
recoatability and scrub resistance. In comparing the above composition 
with commercially available floor polishes excellent results were 
obtained. Also as expected with metallised floor polishes, the films were 
readily removed by dilute alkaline detergents. 
Table 2 
__________________________________________________________________________ 
TS BY WEIGHT 
__________________________________________________________________________ 
METALLISED POLYMER 
1 2 3 4 5 
DISPERSION at 30% SOLIDS 
A 139.94 
B 139.94 
139.94 
C 139.94 
D 139.94 
POLYETHYLENE WAX 
DISPERSIONS at 35% SOLIDS 
AC 392 (Example 4) 
22.52 
22.52 
22.52 
11.26 
22.52 
AC 540 (Example 5) 11.26 
ALKALI SOLUBLE RESIN 
STYRENE-MALEIC 17.51 17.51 
17.51 
17.51 
ANHYDRIDE TYPE at 
15% SOLIDS 
Rosin-based resin at 11.92 
22% SOLIDS 
FLUOROCARBON SURFACT- 
ANT FC 128 1% SOLIDS 
4.00 4.00 4.00 4.00 4.00 
AQUEOUS SOLUTION 
TOTAL 183.97 
178.4 
183.97 
183.97 
183.97 
TOTAL SOLIDS 28.55% 
29.44% 
28.55% 
28.77% 
28.77% 
MFT.degree. C. 49.degree. C. 
49.degree. C. 
44.degree. C. 
47.degree. C. 
35.degree. C. 
__________________________________________________________________________ 
EXAMPLE 7 
A 36% solids metallised emulsion polymer was prepared by addition at room 
temperature of 3.846 parts zinc acetate dihydrate, 5.615 parts ammonium 
hydroxide (0.880) and 3.963 parts 20% Ethylan HA (a Trademark of Lankro 
Chemicals Limited, a synthetic detergent described as nonyl phenol - 35 : 
mol - ethoxylate) in 13.77 parts water to 100 parts of a dispersion of 44% 
solids core polymer produced by split phase emulsion polymerisation at 
75.degree. C. of a monomer mix consisting of 22 % methacrylic acid, 29% 
butyl acrylate and 49% methyl methacrylate using tert-dodecyl mercaptan as 
chain transfer agent. 
A polymer emulsion concentrate of constitution 89.63% of the above 
dispersion, 6.59% polyethylene wax emulsion (25% solids), 1.72% levelling 
aid (1% active FC128- a Trademark of Minnesota Mining and Manufacturing 
Company, a fluorochemical surfactant and 2.06% tributoxyethyl phosphate 
plasticiser was air-fried as a thin film at ambient temperature and 
powdered in a ball mill. 
The dehydrate produced was intimately mixed with ammonium carbonate in 
weight ratio 85 : 15. The product was redispersed in cold tap water to 
give a final dispersion of 16% solids content. 
On coating out this product, a non-buffable, dry-bright polish, an 
excellent finish was obtained after drying. Although no levelling resin 
was included, gloss and levelling were the same as that obtained with a 
commerically available liquid dry-bright polish but had slightly longer 
drying time. 
EXAMPLE 8 
In place of the ammonium carbonate used in Example 7, 
2-amino-2-methylpropan-1-ol carbonate/carbamate was mixed with the 
dehydrate produced in Example 7 in the ratio 87 dehydrate to 13 parts 
base. 
The mixture was dispersed in cold tap water to provide a 16% solids 
dispersion of uniform consistency. On coating out, a dry film with 
excellent gloss and levelling characterisitics was produced. After traffic 
and re-application of a fresh coating self-stripping properties were 
exhibited. In some tests superior gloss and levelling, as compared with a 
self-stripping polish currently available on the market, were observed. 
EXAMPLE 9 
To 89g 2-amino-2-methylpropan-1-ol dissolved in 600g 1.1.1-trichlorethane 
was added 22g solid carbon dioxide with stirring. The temperature of the 
mixture rose to 45.degree. C. and a white precipitate formed which was 
separated by filtration, suspended in 300 ml 40.degree.-60.degree. C. 
petroleum spirit, filtered and dried under vacuum at ambient temperature. 
The white, crystalline product obtained was the carbonate/carbamate salt. 
Using the same technique analogous salts with morpholine, diisopropylamine 
and 3-methoxypropylamine were prepared. 
EXAMPLE 10 
A 36% solids metallised emulsion polymer was prepared by addition at room 
temperature of 2.463 parts zinc acetate dyhydrate, 2.552 parts ammonium 
hydroxide (0.880) and 4.575 parts 20% Sapogenate T500, a synthetic 
detergent described as a tributyl phenol polyglycol ether (a Trademark of 
Fabwerke Hoechst A.G.) in 12.338 parts water to 78,072 parts of a 
dispersion of a 44% solids core polymer produced by split phase emulsion 
polymerisation at 75.degree. C. Of a monomer mix consisting of 12% 
methacrylic acid, 29% butyl acrylate and 59% methyl methacrylate using 
`tert` dodecyl mercaptan as chain transfer agent. 
A polymer emulsion concentrate of constitution 71.99% of the above 
dispersion, 24.29% polyethylene wax emulsion (20% solids), 2.1% 
tributoxyethyl phophate and 1.62% fluorocarbon levelling aid, FC128 (a 
Trademark of Minnesota Mining and Manufacturing Company) (11/2 active) was 
prepared by cold blending. The blend was spray dried in a Niro atomiser 
spray drying unit (supplied by the Niro Company of Denmark), fitted with 
an air broom assembly, at air inlet temperture of 180.degree. C. 
The dried product was dispersed in aqueous ammonia to give 10% solids 
dispersion of pH9. 
A wet, sprayed-on coating on a clear test surface was burnished with a high 
speed polishing machine to produce a durable finish with high sheen. This 
shows that at reduced plasticiser level a useful finish can be prepared by 
this method of the invention. Dried-on spots spray were simply dusted off 
hard surfaces and could be shaken out of drapes. The level of plasticiser 
may be still further reduced if the polymer used has a higher 
concentration of methacrylic acid in the monomer mix then the 12% used in 
this example. High methacrylic acid content is believed to improve the 
self-levelling characteristics of the final polymer and hence compositions 
containing it. Thus, in the range 15% - 25% methacrylic acid content, no 
plasticiser is necessary for spray polishing application; from 5 - 15% 
methacrylic acid content the necessary concentration diminishes with 
increased acid concentration. 
The application of the present invention to the production of 
reconstitutable wax-containing emulsion floor polishes is of great 
advantages because the dehydrated product is not sensitive to moisture 
during shipment being reconstitutable only in alkaline medium. Since only 
coalescent solvent and the base components are omitted there is potential 
saving on special facilities at remote sites otherwise needed to 
incorporate some components, for example plant for production of 
wax-dispersion and the like. 
Utilizing solid bases such as ammonium carbonate or amine 
carbonate/carbamates it is possible to prepare dry powders by mixing 
dehydrated coating compositions lacking base with such solid bases for 
packaging in moisture-proof containers. With such dry compositions the 
user may simply mix with water, especially in the case of compositions for 
use in the "spray-buffing" process.