WO1998003597A1

WO1998003597A1 - Aqueous composition containing anionic polymer and wax emulsion

Info

Publication number: WO1998003597A1
Application number: PCT/GB1997/001964
Authority: WO
Inventors: Mark Anthony Lyth
Original assignee: James Briggs Limited
Priority date: 1996-07-24
Filing date: 1997-07-22
Publication date: 1998-01-29
Also published as: GB9715371D0; GB9615581D0; AU3628197A; GB2315494B; GB2315494A

Abstract

A wax coating comprising an anionic polymer, at least one wax emulsion and water. The wax coating does not utilise hazardous chemical solvents and can be used on all types of wooden surfaces, particularly pine.

Description

AQUEOUS COMPOSITION CONTAINING ANIONIC POLYMER AND WAX EMULSION

The present invention relates to a new and improved polymer wax coating

A variety of products have been used in the past to polish surfaces such as wooden furniture and working surfaces Bees wax was one of the first products used in an attempt

to form a protective coating against dirt and wear and also to impart a lustrous, glossy

finish French polish was also extensively used and since then several polymer based

coatings have been marketed, for example nitrocellulose and acrylic lacquers

The reason for using and developing such polishes has stemmed from the need to

obtain a glossy wax-like finish whilst maintaining a durable coating which protects the

surface to which the coating is applied

Generally speaking, wax coatings have consisted of solvent-based blends of natural

and synthetic waxes, wherein waxes of various melt points are dissolved in aromatic

solvents, the mixture then sets upon cooling, forming a wax paste to be used as a coating on various surfaces

There have been considerable problems associated with the wax products of the

above mentioned type. Typically, when solvent-based products are applied to a surface,

for example wood, the solvent evaporates leaving behind a wax coating which is susceptible to marking, spotting or melting by hot materials such as cups containing hot liquids Also, the applied wax coating is often very thin and several coats are required to be used in order to achieve the desired cover or finish

Further to this, the use of certain chemical solvents in solvent based wax

compositions have proven to be dangerous due to the hazardous nature of the solvents For example, toluene has been used as a solvent-base to prepare wax coatings Toluene is classified as harmful and consequently may be banned from use in many countries It

can therefore no longer be tolerated in a wax coating due to harmful emissions during use,

particularly as such polishes are generally used in the home with no protective measures usually being taken

Traditionally, lacquer finishes have been used to coat wood This method

comprises a labourious multi-step procedure involving an initial step of staining the wood, the pre-treatment step followed by several coats of lacquer, which results in a glossy finish

Much effort has also been made in treating wood surfaces, particularly pine, to

create an "antique" effect This involves the application of several coats of lacquer or wax to achieve the desired "antique" effect, which is essentially similar to the appearance of

old fashioned bees wax polished wood furniture or surfaces

The present invention has been made from a consideration of the above mentioned

problems

It is an object of the present invention to provide a wax coating which does not utilise hazardous chemical solvents and which can be used on all types of wooden

surfaces, particularly pine.

It is a further object of the present invention to provide a wax coating which is less susceptible to marking, water spotting and melting than wax coatings presently in use

It is a further object of the present invention to provide a wax coating which

requires the application of only one or two coatings to produce a wax coating which requires the application of only one or two coats to produce the desired colour or finish,

with no requirement to pretreat the surface prior to application Particularly, it is an

object of the present invention to provide a wax coating which can produce an "antique"

look when applied to a wood surface such as pine.

According to the present invention there is provided a wax coating comprising an anionic polymer, at least one wax emulsion and water

The use of water as the solvent base means that the wax coating of the present

invention is less hazardous than wax coatings utilising chemical solvents as a component

in their manufacture According to a second aspect of the present invention there is provided a method

of applying a wax coating to a surface, the said coating comprising an anionic polymer,

at least one wax emulsion and water.

The wax coating may additionally comprise colourants which stain the surface to

which the coating is applied The use of colourants in the composition is advantageous as it results in staining

of the surface, in particular a surface such as wood, together with providing a protective

film on the surface and imparting a glossy finish without the need for a multi-step

procedure to achieve the same effect, as required by the prior art

Typically, the present invention utilises pigment dispersions to provide colour to

the composition of the present invention In the past, dye solutions have been used to provide the same effect. Pigment dispersions provide a stronger colour strength to the

emulsion of the present invention than the prior art dye solutions and also offer better light fastness

For example, the wax coating may comprise one or more of the following colour

pigment components - Red 184, yellow 83, red 9, black 7, green 7 These pigments may be obtained commercially, one of the sources being the "Hosta fine" (Brand name) range

of pigment preparations marketed by Hoechst (Trade Mark)

The wax coating does not necessarily contain additional colourants It can be used as a clear coating which allows the natural surface characteristics of the wood to be

appreciated

The anionic polymer component used in the present invention preferably comprises 0-40% by weight of the total composition More preferably, it comprises 5-25% by

weight of the total composition Most preferably, it comprises 10-20% by weight of the

total composition

Suitable anionic polymers include polymers and their derivatives being selected

from the following - Acrylic copolymers, for example, acrylate/methacrylate esters with fine particle

dispersion The anionic polymer component is preferably formulated as an emulsion

The anionic polymer component is particularly important It contributes to the

film build characteristics of the present invention Consequently, the applied film imparts a higher film thickness than traditional waxes and reduces the need for the application of

two or more coats in order to achieve the desired protective effect of the coating

Furthermore, the polymer component affects the drying time of the applied film

Typically, the drying time of a coating applied in accordance with the present invention is between 10-30 minutes. This time period, when compared with the time requirement of methods such as French polishing of wooden surfaces, which is extremely time

consuming and labourious, is a considerable advantage of the coating and method of the

present invention. The choice of the polymer component in the wax coating is particularly important

as it influences how much of the coating is absorbed by the surface onto which it is applied In the past, several coats of wax/lacquer have been required due to the porous

nature of surfaces such as pine The first coat is usually absorbed by the porous surface

and further coats are required to impart a protective film and glossy finish Quite often

it is necessary to pretreat the wood so as to provide a less porous surface to which a wax

coating may be applied.

The wax coating of the present invention is absorbed to a less degree by porous surfaces, such as pine. The choice of polymer and its interaction with the other

components of the coating of the present invention contributes to the decreased

absorbency of the coating by a porous surface thus resulting in the requirement of only one or two applications of the wax coating to a surface.

The wax emulsion used in the present invention is preferably non-ionic

A suitable wax emulsion to be used in the present invention includes a polymeric

wax emulsion, preferably a polyethylene wax emulsion. Further suitable non-ionic wax emulsions comprise waxes with a melt point in the

range of 50-150°C. If the melt point is too high the coating will set and form a hard composition. Preferably, the non-ionic wax emulsion comprises wax with a melt point in the range 70- MOT.

A preferred non-ionic wax emulsion used in the present invention is a "Montan" type of wax emulsion. This comprises a non-ionic emulsion including one or more waxes

with a melt point in the range of 79-85°C and the maximum particle size being 1 micron

Preferably, the wax emulsion component may consist of one or more of the above mentioned suitable components Preferably, it comprises 0-40% by weight of the total

composition More preferably, it comprises 10-20% by weight of the total composition

Most preferably, it comprises 10-16% by weight of the total composition

The primary function of the wax coating system is to provide a protective film together with a glossy finish to the surface The ratio of polymer to wax component contributes to the film build and drying time characteristics The coating may also include

other components commonly used in wax coatings Plasticisers, humectants, defoamers,

gelling agents, preservatives, surfactants and emulsifiers may be incorporated in the usual manner

The choice of plasticiser also appears to affect the unique characteristics of the wax coating of the present invention Phthalates appear to enhance the characteristics of the wax coating and the most preferred plasticisers is Butylbenzylphthalate

Examples of polymer wax coatings include liquids and the viscosity may be altered

so as to form a stiff paste The coating may be applied by brush, spray gun or cloth

The invention will now be further illustrated by way of the following examples. Example 1

Polymer wax coatings were formulated as follows

Component Paste Liquid Sprav

% by weight % bv weight %bv weight

Acrylic copolymer 16 6 17 1 14 54

Butyl benzyl phthalate 2 6 2 6 2 21

Monopropylene glycol 7 0 7 0 5 95

Anti-foaming agent 0 2 0 2 0 17

Polyethylene wax emulsion 12 4 12 4 10 54

Montan wax emulsion 2 7 2 7 2 30

Preservative 0 5 0 5 0 050

Viscosity-modifier 0 5

Non-ionic surfactant

Colourants - Red 184 0 02 0 02 0 02

Yellow 83 0 02 0 02 0 02

Black 7 0 02 0 02 0 02

Red 9

Green 7 Water 57 44 57 44 63 75

Ratio and choice of pigments is dependant upon the required shade

Example 1 was made as follows -

Charge mixing vessel with the copolymer, and add each item in order slowly during agitation, care must be taken to avoid aeration Pigment flocculation can occur if

the correct mixing procedure is not followed The paste formulation must be filled into the containers within 3 hours of manufacture

In comparison with a traditional wax, the above formulation has displayed

increased film thickness, reduced drying time, substantially less marking with increased resistance to water and common soiling and increased resistance to heat, resulting in a much more durable coating

The following experimental results illustrate the superior performance of the wax

coating of the present invention as compared with two presently known wax coatings The components of the two known wax coatings are as follows -

Fiddies (Trade Mark) Stripped Pine durable wood finish comprises aliphatic Solvent containing 12% aromatic solvent, this solvent mixture commonly known as Rubber Solvent comprises 74% of the wood finish The remainder of the wood finish

comprises waxes and dyestuffs

Briwax Antique Mahogany (Trade Mark) comprises 50-75% toluene and the

remainder of the coating comprises waxes and dyestuffs

Method of Testing

Each of the wood finishes listed above were applied onto pine covered hardboard

( 190mm x 210mm) via the use of a soft cloth A second coat was then applied 30 minutes

after the first coat, by the same method This process was then repeated for addition of a third coat In each case the dry and wet mass of the three coats was measured to

determine the coverage potential of each product. A number of dry film properties were then tested for each product

Abrasion Resistance

The abrasion resistance was tested using a pad (100mm x 50mm) of synthetic wire

wool grade 0000 extra fine The pad of wire wool was placed onto the dry coating

surface, a 500 gram mass was then placed on top of the wire wool, this was then dragged

across the surface of the coating This constituted 1 "rub", each coated board was then subjected to 300 such rubs, after which observations were then made about the resultant

condition of the coating

Chemical Resistance A number of materials namely, water, bleach, solvent based cleaner, coffee, methanol, milk and upholstery cleaner were placed on the dry coating's surface Each

spot of liquid was left on the coating's surface for 60 minutes after which the liquids were washed off with water and dried The coating's surface was then inspected for any

degradation

Ring Resistance

A mug containing boiling water was placed on the coating's surface for 60 minutes, after which the mug was removed and the coating's surface inspected for any

marks

This test was then repeated, however, in this case the coating surface was

dampened with a sponge, to provide a film of water on the surface of the coating

Temperature/Water Resistance

A coated board was inclined at 45 degrees, then 1 litre of boiling water was poured down the board, after which the board was inspected to check for the integrity of

the film This test was then carried out for all three products

Results

Ease of Application The wax of the present invention was found to be the most "user friendly" wood

finish The application of pine wax was relatively easy and produced a very good and

even final film

Problems were encountered when applying the Fiddies product, especially when

applying the second and third coats as lumps of the coating occurred on the surface (which could be rubbed out) thereby causing an uneven colour and finish This was a result of the fact that the Fiddies product was in a solid form and requires very careful

application m order to spread an even film, when compared to the lower viscosity Briggs

pine wax paste which flowed out very easily

The Briwax product also gave rise to similar problems, however, these were not as severe as encountered in the Fiddies product as the Briwax product was slightly more paste like

Coverage

Fiddies Stripped Pine Durable Wood Finish = 20 lOg/m²

Briwax = 14 51g/m³ James Briggs Pine Wax = 30 83g/πr

The Briwax product shows the least amount of material required to cover a square

metre of substrate However, the highest value as shown by Briggs pine wax indicates the relative ease of application when compared to the other two products

Abrasion Resistance

The James Briggs pine wax showed vastly superior abrasion resistance than the

other two products The board showed an actual increase in gloss as the test had simply

"buffed up" the pine wax coating

The other two products showed a clear discolouration as a significant amount of

material was abraded from the surface of the board In fact small patches of bare wood

were exposed on the Fiddies test board

These results are due to the fact that both the Fiddies and Briwax products are

simply coloured waxes which have limited film integrity The Briggs pine wax actually

seals the wood as well as providing a coloured wax finish as it contains a polymer film

former

Chemical Resistance

FIDDIES BRIGGS BRΓWAX

Water Fair Excellent Poor

Bleach Poor Poor Poor

Solvent Cleaner Poor Good Very Poor

Coffee Fair Fair Fair

Methanol Fair Good Fair

Milk Fair Excellent Poor

Upholstery Cleaner Poor Excellent Poor

It can be seen that Briggs pine wax has a significantly better chemical resistance

than the other two products This is due to the polymeric film former within Briggs pine wax which imparts a better chemical resistance than the simple waxes which make up the

Fiddies and Briwax products

Ring Resistance

None of the three products exhibited white rings in either the dry or wet ring

resistance test

However, the Fiddies and Briwax films did show circles of high gloss where the mugs had rested This was due to the waxes being heated by the mugs and flowing out

to form a smooth surface Also the wet ring resistance test results showed that water

discoloured the surface of both the Fiddies and Briwax products The Briggs pine wax was unaffected by both the dry and wet ring resistance tests

The surface suffered no discolouration in either test and was not affected by contact with water This improved resistance is due once again to the polymer film former providing

a stable heat resistant film

Temperature/Water Resistance Both the Fiddies and Briwax products suffered severe discolouration as the boiling

water melted the waxes contained in both and simply washed them of the board to leave

the actual surface of the wood substrate exposed

The Briggs pine wax was unaffected as a result of the polymer film former

protecting the pigment and waxes contained in the formulation

Conclusion

The Briggs pine wax was certainly the easiest to apply and therefore gave the most attractive finish, however, this resulted in it having the largest wet film mass per square metre However, it must be realised that in order for the Briwax and Fiddies products to fulfil the same role, a primer/sealant would be required which would increase the coverage

figure significantly

The Briggs pine wax was clearly the most robust wood finish as a result of the polymer film former The polymer sealed the wood substrate and protected the wax and

pigmentation from chemical attack and heat

The Fiddies and Briwax products simply contained a pigment and waxes, therefore exposure to chemicals and heat resulted in the removal each of the products from the

wood surface The above invention is not restricted to the above described embodiments and

many variations and modifications can be made.

Claims

Ciaims

1 A wax coating comprising an anionic polymer, at least one wax emulsion and water

2 A wax coating according to claim 1 , wherein the anionic polymer component

comprises up to 40% by weight of the total composition

3 A wax coating according to claim 2, wherein the anionic polymer component

comprises 5-25% by weight of the total composition

4 A wax coating according to claim 3, wherein the anionic polymer component

comprises 10-20% by weight of the total composition 5. A wax coating according to preceding claim wherein the anionic polymer

component comprises acrylic copolymer

6 A wax coating according to claim 5, wherein the acrylic copolymer comprises acrylate/methacrylate esters

7 A wax coating according to any of the preceding claims, wherein the anionic

polymer component is an emulsion

8. A wax coating according to any preceding claim, wherein the wax emulsion is non- ionic

9 A wax coating according to any preceding claim, wherein the wax emulsion is polymeric.

10. A wax coating according to any preceding claim, wherein the wax emulsion is a

polyethylene wax emulsion

1 1 A wax coating according to any preceding claim, wherein the wax emulsion comprises at least one wax with a melt point in the range 50-150°C

12 A wax coating according to claim 11, wherein the at least one wax has a melt

point in the range 70-140°C

13 A wax coating according to claim 12, wherein the wax emulsion comprises at least

one wax with a melt point in the range 79-85°C and the maximum particle size is 1 micron

14 A wax coating according to any preceding claim, wherein the wax emulsion comprises up to 40% by weight of the total composition

15. A wax coating according to any preceding claim, wherein the wax emulsion

comprises 10-20% by weight of the total composition.

16 A wax coating according to any preceding claim, wherein the wax emulsion comprises 10-16% by weight of the total composition.

17. A wax coating as claimed in any preceding claim, additionally comprising

colourants which stain the surface to which the coating is applied 18 A method of applying a wax coating to a surface, the said coating comprising an

anionic polymer, at least one wax emulsion and water.

19. A wax coating in accordance with the invention as described with reference to the

example.