GB2559137A

GB2559137A - Surface coating composition

Info

Publication number: GB2559137A
Application number: GB1701270.9A
Authority: GB
Inventors: Nicholas Robb Benjamin
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-01-25
Filing date: 2017-01-25
Publication date: 2018-08-01
Anticipated expiration: 2037-01-25
Also published as: GB201701270D0; GB2559137B

Abstract

A surface coating composition comprises a wax, a thinner, a carrier, a hardening agent, a varnish, and a drying agent, wherein the drying agent is an aqueous metal complex. The wax may be beeswax and the thinner may be a terpenoid selected from lavender oil or limonene. The carrier is preferably a triglyceride or an aliphatic carboxylic acid, such as linseed oil. The hardening agent may be based on an aliphatic carboxylic acid, such as tung oil and the varnish may be a triterpenoid resin, especially dammar. Typically, the drying agent is an aqueous metal complex comprising Fe or Mn iron as the metal with a nitrogen donor ligand, which may be monodentate, bidentate, tridentate, tetradentate, pentadentate, or hexadentate. A wood product, especially wooden flooring, coated with the surface coating composition is also disclosed.

Description

(54) Title of the Invention: Surface coating composition Abstract Title: Surface coating composition (57) A surface coating composition comprises a wax, a thinner, a carrier, a hardening agent, a varnish, and a drying agent, whereinthe drying agent is an aqueous metal complex. The wax may be beeswax and the thinner may be a terpenoid selected from lavender oil or iimonene. The carrier is preferably a triglyceride or an aliphatic carboxylic acid, such as linseed oil. The hardening agent may be based on an aliphatic carboxylic acid, such as tung oil and the varnish may be a triterpenoid resin, especially dammar. Typically, the drying agent is an aqueous metal complex comprising Fe or Mn iron as the metal with a nitrogen donor ligand, which may be monodentate, bidentate, tridentate, tetradentate, pentadentate, or hexadentate. A wood product, especially wooden flooring, coated with the surface coating composition is also disclosed.

transmittance of moisture through membrane l/l s Sample Coated

01 18

Vapour Permeability 'breathability’ Test

Figure I

Aborption Weight in 24 hours - Single coat

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.82 grams

0.79 grams

0.55 grams

0.25 grams #1 - Hardwax Oil as described #2 - Danish Oil by others #3 - Polyurethane Lacquer by others #4 - Water Based Lacquer by others

Figure 2 - Showing absorption weight over a period of 24 hours

Surface Coating Composition

Field of the Invention

The present invention relates to a surface coating composition. In particular but not 5 exclusively the surface coating composition is a hardwax oil made from materials that will have no or minimal impact on the environment.

Background of the Invention

Surface coating compositions such as waxes have been used for finishing the surface of 10 wood for many years and once wax is applied to a surface, what remains is a layer of wax that is trapped in the pores of the wood and which hardens and coats the surface of the wood to which it is applied to. Also wood has been treated over the years by applying oils, such as Danish oil, which soaks into the surface of the wood. However neither of these types of wood treatment produces a strong and breathable hard wearing coating on the surface of the wood.

Lacquers have been used on wood which are solvent based products that can be used to coat the wood and as it dries it forms a hard surface coating. Lacquers are usually solvent based so there is an increased environmental impact through their use because of the release of volatiles during the drying process which means that in situations where a low environmental footprint is required then lacquers would not meet such criteria.

More recently products have come onto the market which are called “hardwax oils” 25 which are an oil based finish that soaks into wood and forms a protective film on the

I surface of the wood as well as feeding the layer of wood just beneath the wood surface. The hardwax oil combines the effect of; saturation of the wood which is what was traditionally done using beeswax or oils with the formation of a protective film on the surface of the wood. The use of a hardwax oil allows for a surface that can still breathe and at the same time repels dirt and moisture, which can be contrasted with a lacquer surface which does not have the breathability that a hardwax oil surface allows for.

There is a range of hardwax oils on the market but many earlier oils included solvents, 10 which means that they still had environmental impact on the release or organic volatiles. More recently vegetable oils and wax bases have been used to meet the

European VOC Regulation EU 2012 but in order to provide adequate drying times for these coatings cobalt based driers are still used which means that there is still an environmental impact because cobalt can be toxic if ingested above recommended amounts; it is also a known carcinogen.

The present invention seeks to overcome the problems of the prior art by providing a surface coating composition which is effective, dries to provide a hard wearing surface, which is designed to resist wear over a period of time and which has minimal environmental impact in its application and use.

Summary of the Invention

According to a first aspect of the invention there is provided a surface coating composition comprising a wax, a thinner, one or more carriers, at least one hardening agent, at least one varnish and one or more drying agents wherein the at least one drying agent is an aqueous metal complex.

The wax may be a beeswax. Alternatively or additionally the wax may comprise, consist of or include: candelilla wax; carnauba wax; or soy wax.

It is envisaged that the thinner is a terpenoid. Preferably the terpenoid is selected from one or more of a spike lavender oil or limonene.

It is envisaged that the one or more carriers is selected from one or more of a triglyceride, an aliphatic carboxylic acid.

It is preferred that when the carrier is a triglyceride, the carrier is linseed oil.

It is envisaged that if the carrier is an aliphatic carboxylic acid then the carrier is tung oil.

Preferably the one or more varnishes is a triterpenoid resin. A preferred triterpenoid resin is dammar.

It is envisaged that the at least one drying agents based on an aqueous metal complex comprises a metal and at least one nitrogen donor ligand wherein the metal is selected from Fe or Mn iron and the nitrogen donor ligand is selected from monodentate, bidentate, tridentate, tetradentate, pentadentate and hexadentate nitrogen donor ligands.

In a first aspect of the invention the surface coating composition comprises, for 10 litres of composition:

1.3 to 1.6 litres by volume of bees wax

2.1 to3 litres of L-limonene to 2 litres of linseed oil

1.5 to 2.3 litres of tung oil to 2.5 litres of dammar and 2 to 2.5% by volume of the at least one drying agent based on an aqueous metal complex.

In an alternative aspect of the invention the coating composition comprises for 10 litres of composition:

1.3 to 1.6 litres by volume of bees wax

2.1 to3 litres of lavender oil to 2 litres of linseed oil

1.5 to 2.3 litres of tung oil to 2.5 litres of dammar and 2 to 2.5% weight by volume of the at least one drying agent based on an aqueous metal complex.

The viscosity of the material is such that it allows thin coats to be applied thinly which facilitates the drying of each coat. It is given that a recommendation of two coats will be required for the treatment of wood.

According to a further aspect of the invention there is provided a product coated with a composition according to any preceding claim.

Preferably the product is a wood product, but can be any porous material that allows surface penetration.

Limonene is a solvent. The solvents in the recipes of some embodiments act to thin the material to aid in application and allow for a thin coat application to facilitate the drying. If the product is too thick the oils in the mix won’t dry.

Limonene is a colourless liquid hydrocarbon classified as a cyclic terpene and is also a

VOC.

Lavender spike oil may be used in some embodiments.

Different aspects and embodiments of the invention may be used separately or together.

Further particular and preferred aspects of the present invention are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with the features of the independent claims as appropriate, and in combination other than those explicitly set out in the claims.

Brief description of the drawings

Embodiments of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:

Detailed description of preferred embodiments

The example embodiments are described in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternate forms and should not be construed as limited to the examples set forth herein.

Accordingly, while embodiment can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.

Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealised or overly formal sense unless expressly so defined herein.

Referring now to the drawings, wherein like reference numbers are used to designate 5 like elements throughout the various views, several embodiments of the present invention are further described. The figures are not necessary drawn to scale, and in some instances the drawings have been exaggerated or simplified for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations of the present invention based on the following examples of possible embodiments of the present invention.

This invention relates to compositions that are used to treat hard surfaces such as wood in order to enhance their appearance and durability of the wood surface in a way that avoids impact on the environment by increasing volatiles in the atmosphere and also as a result of chemicals leaching into the land when a product is disposed of.

The coating formulation of the present invention combines a way of enhancing resistance to the ingress of moisture and dirt on a surface while providing a surface that is resistant to damage through wear and tear.

The surface substrates of the current disclosure includes a variety of substrates, made from various materials, such as wood, paper, cardboard but the invention has particular application to hard porous surface such as wood.

Many flooring materials are made from wood planks but also such substrates could include wood veneers and so the invention could apply to both types of material. In addition, as well as being used inside the formulation can be used in exterior environments such as on outdoor decks or on outside furniture or fixings.

The coating composition of the present disclosure provides enhanced flexibility in application previously not achieved by known coating systems as it provides water resistance earlier in the coating process as well as early water resistance during the coating process as the present coating formulation dries rapidly and does not need extended drying times.

A component of the formulation of the present invention is beeswax which has as one of its main components, triacontanyl palmitate, which is a wax ester and a typical chemical formula for beeswax is C|₅H₃|COOC₃₀H₆| The amount of wax in the formulation is between 1.3 and 1.6 litres by volume.

In order to produce a composition having the necessary viscosity to cover and be absorbed to some extent into a surface, then the composition includes thinners. Limonene and in particular the stereo-isotope L-limonene can be used or as an alternative spike lavender oil, which can be used, not only to provide the composition with flow characteristic to be absorbed into the surface but it can also provide the composition with a pleasant fragrance.

Spike lavender oil has a number of chemical components including a-pinene, limonene, 1,8-cineole, cis-ocimene, trans-ocimene, 3-octanone, camphor, linalool, linalyl acetate, caryophyllene, terpinen-4-ol and lavendulyl acetate. The thinners are used in an amount of between 2 and 3 litres per 10 litres of composition and a more typical amount that is used is 2.66 litres per ten litres appximately.

The carrier for the composition is again based on non-volatile material and is used in an amount of between I and 21.5 litres per 10 litres of total composition. A typical amount that is used is 1.33 litres per 10 litres of composition. The carrier is a drying oil and it can be obtained from a number of natural sources, for example sources of oils from plants include linseed oil, safflower oil, poppy oil, soybean oil, tung oil, and walnut oil.

In one approach, suitable oils are selected from the group of drying oils for their differing qualities. Drying oils are fatty oils of vegetable matter that can react chemically with oxygen in the air to solidify and become dry to the touch.

A preferred carrier is linseed oil because it is readily available and is easily absorbed onto surface and also is non-toxic. Linseed oil has particularly good drying properties and it also has good water repelling properties. Furthermore, linseed oil shrinks little on hardening and sinks into the pores of the surface to which it is applied leaving a shiny but not glossy surface which in the case of wood shows off the grain in the wood.

The composition includes tung oil in an amount of between 1.8 and 2.3 litres per 10 litres of composition. A preferred amount is 2 litres per 10 litres of composition approximately. Pure tung oil again is highly resistant to water, alcohol and acids and hence provides a hard-wearing surface whilst giving a degree of anti-fungal properties to the composition.

Tung oil is made up of a number of fatty acids and the major fatty acid composition of tung oil are as follows:

Alpha-eleostearic acid 82.0%

Linoleic acid 8.5%

Palmitic acid 5.5%

Oleic acid 4.0%

The primary constituent is an 18 carbon chain aliphatic carboxylic acid.

When the orientation is maintained such that the fatty tails are oriented towards the air surface of the coating to convey water resistance properties, the aqueous coating composition provides a protective layer over the underlying wood substrate. The coatings of the present disclosure provides a quick drying- layer, but also provides protection during the drying process as the coatings of the present disclosure does not require any reactions, such as cross-linking, to occur before a protective layer is formed.

The composition also includes a varnish and typically this is a gum and a particularly useful gum is a triterpenoid resin such as dammar. The resin is used in an amount of io between 2 and 2.5 litres per 10 litres of total composition but a typical amount that is sued is 2.33 litres per 10 litres of resultant composition.

In addition in order to provide a composition with a relatively fast drying time a drying 5 agent is also included.

The coating composition of the present invention may optionally comprise up to 0.01 wt. % to 10 wt. % of additives, such as I % to 8%, such as 3% to 6%, by weight additives. Without limitation, suitable additives include: surfactants, anti-oxidants, fillers, extenders, pigments, optical brighteners, light stabilizers, biocides, thickeners, preservatives, and, co-solvents. Any such additives present should be dispersed, preferably homogenously, throughout the coating composition and the additives that are selected are selected to have minimal environmental impact, for example risk of pollution.

Surfactants (surface-active agents) form a group of additives which may be present in the coating composition to provide smooth, uniform coatings. Suitable surfactants include, but are not limited to, flow control agents, wetting agents, dispersants, adhesion enhancers and de-foamers. The preferred surfactants are either non-ionic or anionic.

Turning now to the method of imparting water resistance to a substrate, the present disclosure provides a method of imparting water resistance to a substrate by applying to a substrate an aqueous coating composition comprising an aqueous solvent and a fatty amine quaternary of the structure (I) as presented above. By one approach, the substrate is a wooden substrate. The wooden substrate to be coated may be of any form known in the art, including for example unedged timber, flitches, boules, halfedged boards, square-edged lumber, strips, squares, carcassing, truss beams, scantlings and tongue-and- groove flooring, such as parquet, decking and anti-slip decking which may be coated on one or both sides. The coatings of the present invention may be applied to fully cover said substrates or to cover only parts thereof, including edges, curvilinear surfaces, routered and beveled areas. The particular wood surface to be coated may be cleaned and prepared for application of the disclosed coating compositions using methods, such as sanding, that will be familiar to those skilled in the art.

This Example compares the ‘breathability’ vapour permeability of the coating composition between the said composition and 4 other market leading products that facilitate surface coatings for wood. A method was devised based on the upright cup test, to test the transfer of moisture through a coated membrane and thus determine the coating’s breathability in comparison to other products.

For wood coatings, vapour permeability is as important as the coating’s weatherability and ability to repel water. Vapour permeability is connected to the longevity and performance over time of the coating through its ability to allow the transfer of moisture to and from the wood and thus the separation of the coating through such natural processes is greatly reduced over time.

(A) Vapour Permeability Measurement Using Calcium Chloride

Four separate cup tests were prepared as shown and described in Figure I whereby four separate cellulose membranes were treated with a single coating of the sample as listed below and allowed to harden for 24 hours.

Sample #1	- Hardwax oil as described
Sample #2	- Danish oil; by others
Sample #3	- Polyurethane Lacquer; by others
Sample #4	- Water Based Lacquer; by others

The coated membranes were then fixed and sealed to four separate glass up right containers; each containing 12.6 grams of calcium chloride. The four samples were left for a period of 24 hours in 9 degrees C, at 100% humidity. Calcium chloride for the purpose of this test was used as a desiccant for its ability to absorb moisture and thus enable the measurement of the coatings ability to permit the transfer of moisture.

Each sample was weighed at the beginning of the 24 hour period and then again at the end. The weight difference was compared and then plotted as shown in the Figure 2.

The weight difference directly correlates to the coating’s vapor permeability, through the ability of the calcium chloride to draw moisture through the membrane.

The higher the weight the greater the permeability. Measurement results comparing the amount of absorption between each test sample are shown in the graph.

Conclusion; both the danish oil and the water based lacquer achieved high levels of vapour permeability. However, the required subsequent coats would reduce this permeability. It should also be noted that durability and weatherability is less for both these coatings than the polyurethane and the hardwax oil. There is a compromise between durability/weatherability and breathability. The hardwax oil as described within strikes a balance between durability/weatherability and breathability.

Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiments shown and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention. Furthermore, although individual embodiments of the invention may have been described, the invention is intended to include combinations of those embodiments.

Claims

1. A surface coating composition comprising a wax, at least one thinner, one or more carriers, one or more hardening agents, at least one varnish and one or 5 more drying agents wherein at least one drying agent is an aqueous metal complex. 2. A surface coating according to claim 1, wherein the wax is a beeswax. 10 3. A surface coating according to claim 1 or claim 2 wherein the at least one thinner is a terpenoid. 4. A surface coating according to claim 3 wherein the terpenoid is selected from one or more of a lavender oil or limonene. 15 5. A surface coating according to any preceding claim wherein the one or more carrier is selected from one or more of a triglyceride, an aliphatic carboxylic acid. 20 6. A surface coating according to claim 5 wherein the one or more carriers is a triglyceride. 7. A surface coating according to claim 6 wherein the one or more carriers is linseed oil.

8. A surface coating according to any preceding claim wherein the hardening agent is based on an aliphatic carboxylic acid.

9. A surface coating according to claim 8 wherein the hardening agent is tung oil.

10. A surface coating composition according to any preceding claim wherein the one or more varnishes is a triterpenoid resin.

I I. A surface coating according to claim 10 wherein the triterpenoid resin is

10 dammar.

12. A surface coating according to any preceding claim wherein the at least one drying agents based on an aqueous metal complex comprises a metal and at least one nitrogen donor ligand wherein the metal is selected from Fe or Mn

15 iron and the nitrogen donor ligand is selected from monodentate, bidentate, tridentate, tetradentate, pentadentate and hexadentate nitrogen donor ligands.

13. A surface coating agent according to any preceding claim wherein the surface coating composition comprises, for 10 litres of composition:

20 1.3 to 1.6 litres by volume of bees wax

2.1 to3 litres of L-limonene

1 to 2 litres of linseed oil

1.5 to 2.3 litres of tung oil

2 to 2.5 litres of dammar and 2 to 2.5% weight by volume of the at least one drying agent based on an aqueous metal complex.

14. A surface coating composition according to any of claims I to 12, wherein 5 the coating composition comprises for 10 litres of composition:

1.3 to 1.6 litres by volume of bees wax 2.1 to3 litres of spike lavender oil

I to 2 litres of linseed oil

1.5 to 2.3 litres of tung oil

10 2 to 2.5 litres of dammar and 2 to 2.25% weight by volume of at least one drying agent based on an aqueous metal complex.

15. A surface coating composition substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings/tables.

16. A product coated with a surface coating composition according to any preceding claim.

17. A wood product coated with a surface coating composition according to any of

20 claims I to 15.

18. Wooden flooring coated with a surface coating composition according to any of claims I to 15.

Application No: GB1701270.9 Examiner: Dr Paul Minton