Claims:1. A water based anti-algal coating composition comprising:
a. an anti-algal coating base comprising:
i. a fluid medium comprising:
- water in an amount in the range of 15 wt% to 50 wt% of the total amount of the coating composition; and
- an organic fluid medium in an amount in the range of 1 wt% to 15 wt% of the total amount of the coating composition, wherein the organic fluid medium comprises at least one compound selected from C2-C12 glycol, C2-C12 polyol, C2-C12 polyether glycol and C1-C8 alcohol; and
ii. a sparsely water soluble component comprising at least one compound selected from the group consisting of copper (I) cyanide, copper (I) thiocynate and compound of formula (I) in an amount in the range of 1 wt% to 7 wt% of the total amount of the coating composition;
wherein the compound of formula (I) is represented as
Cu(PR1(z)R2(3-z))x(HOR3)yA

(I)
wherein,
A is selected from the group consisting of acetate (OAc), chloride (Cl), bromide (Br), iodide (I) and nitrate (NO3);
x is an integer ranging from 1 to 3, y is an integer ranging from 0 to 2, z is an integer ranging from 0 to 3, and x+y=3;
R1 is an alkyl or substituted alkyl; R2 is selected from the group consisting of phenyl, alkyl aryl, substituted phenyl, fused aryl phenyl, and substituted phenyl; and R3 is selected from the group consisting of alkyl, substituted alkyl or hydroxyalkyl;
wherein the particle size of the sparsely water soluble component present in the anti-algal coating base is in the range of 5 to 25 µm; and
b. a polymeric binder in an amount in the range of 5 wt% to 65 wt% of the total amount of the coating composition.
2. The composition as claimed in claim 1, wherein the compound of formula (I) is selected from the group consisting of Cu(PPh3)3Cl, Cu(PPh3)3Br, Cu(PPh3)3I, Cu(PPh3)3NO3, Cu(PPh3)2(CH3OH)(OAc), Cu(PPh3)2(C3H7OH)(OAc), Cu(PPh3)2(C4H9OH)(OAc), Cu(PPh3)2(C5H11OH)(OAc), Cu(PPh3)2(C6H13OH)(OAc), Cu(PPh3)2(C7H15OH)(OAc), Cu(PPh3)2(C8H17OH)(OAc), Cu(PPh3)2(C9H19OH)(OAc), Cu(PPh3)2(C10H21OH)(OAc), and Cu(PPh3)2(C12H25OH)(OAc).
3. The composition as claimed in claim 1, wherein the compound of formula (I) is a complex of Cu(PPh3)2.OAc with at least one compound selected from ethylene glycol, di-ethylene glycol, tri-ethylene glycol, polyethylene glycol methyl ether, polyethylene glycol nonylphenyl ether, trimethylolpropane, neopentyl glycol, glycerol, cerenol, 2-ethoxyethanol, 2-butoxyethanol and propylene glycol n-propyl ether.
4. The composition as claimed in claim 1, wherein the particle size of the sparsely water soluble component present in the anti-algal coating base is in the range of 5 µm to 15 µm.
5. The composition as claimed in claim 1, wherein the binder is at least one acrylic polymer selected from the group consisting of waterborne carboxylated acrylic copolymers, hydroxy acrylic copolymers, acrylonitrile acrylic copolymers, carboxylated polyvinylchloride acrylic copolymers, and styrene acrylate copolymers.
6. The composition as claimed in claim 1, wherein the anti-algal coating base further comprises an organic open time enhancer in an amount in the range of 1 wt% to 2 wt% of the total amount of the coating composition, wherein the open time enhancer is at least one selected from the group consisting of polyol and polyether.
7. The composition as claimed in claim 1, wherein the anti-algal coating base further comprises a pigment and an extender in an amount in the range of 5 wt% to 30 wt% of the total amount of the coating composition.
8. The composition as claimed in claim 7, wherein the pigment is at least one selected from the group consisting of rutile titanium dioxide, anatase titanium dioxide, zinc oxide, leaded zinc oxide, zinc sulfide, lead titanate, antimony oxide, zirconium oxide, white lead, basic lead silicate, lithopone, titanated lithopone, titanium-barium pigment, titanium-calcium pigment and titanium-magnesium pigment.
9. The composition as claimed in claim 7, wherein the extender is at least one selected from the group consisting of calcium carbonate, talc, clays, dolomite, silica and silicates.
10. The composition as claimed in claim 1, wherein the anti-algal coating base further comprises a defoamer in an amount in the range of 0.1 wt% to 1 wt% of the total amount of the coating composition, wherein the defoamer is a substituted paraffin hydrocarbon.
11. The composition as claimed in claim 1, wherein the anti-algal coating base further comprises a coalescing agent in an amount in the range of 0.1 to 0.5 wt% of the total amount of the coating composition, wherein the coalescing agent is at least one selected from the group consisting of polyol and substituted alcohol.
12. The composition as claimed in claim 1, wherein the anti-algal coating base further comprises a thickening agent in an amount in the range of 0.2 to 0.5 wt% of the total amount of the coating composition, wherein the thickening agent is at least one selected from the group consisting of cellulose and derivatives thereof, polyurea derivatives, polyetherurea derivatives, polyurethane derivatives and polyureaurethane derivatives.
13. The composition as claimed in claim 1, wherein the anti-algal coating base further comprises an amine, wherein the amine is at least one selected from the group consisting of ammonia, substituted amine and amino-alcohol.
14. The composition as claimed in claim 1, wherein the water based coating composition further comprises an organic opacifier in an amount in the range of 3 wt% to 20 wt% of the total amount of the coating composition.
15. The composition as claimed in claim 1, wherein the anti-algal coating base is a mill base comprising:
i. a sparsely water soluble component in an amount in the range of 20 wt% to 63 wt% of the total amount of the anti-algal coating base;
ii. an organic fluid medium in an amount in the range of 10 wt% to 20 wt% of the total amount of the anti-algal coating base;
iii. water in an amount in the range of 10 wt% to 20 wt% of the total amount of the anti-algal coating base;
iv. open time enhancer in an amount in the range of 1 wt% to 2 wt% of the total amount of the anti-algal coating base;
v. defoamer in an amount in the range of 0.1 wt% to 1 wt% of the total amount of the anti-algal coating base;
vi. wetting agent in an amount in the range of 0.5 wt% to 1.5 wt% of the total amount of the anti-algal coating base;
vii. dispersing agent in an amount in the range of 0.2 wt% to 1 wt% of the total amount of the anti-algal coating base; and
viii. pigment and extender in an amount in the range of 15 wt% to 35 wt% of the total amount of the anti-algal coating base;
wherein, the anti-algal base is adapted to mix with the polymeric binder, prior to use, to impart anti-algal properties to the coating composition produced thereby.
16. The composition as claimed in claim 1 comprises:
i. water in an amount in the range of 20 wt% to 40 wt% the total amount of the anti-algal coating composition;
ii. organic fluid medium in the range of 1 wt% to 2 wt% the total amount of the anti-algal coating composition;
iii. a sparsely water soluble component in an amount in the range of 3 to 10 wt% the total amount of the anti-algal coating composition;
iv. wetting agent in an amount in the range of 0.5 wt% to 1.5 wt% the total amount of the anti-algal coating composition;
v. dispersing agent in an amount in the range of 0.2 wt% to 1 wt% the total amount of the anti-algal coating composition;
vi. defoamer in an amount in the range of 0.1 wt% to 1 wt% the total amount of the anti-algal coating composition; and
vii. polymeric binder in an amount in the range of 40 wt% to 70 wt% the total amount of the anti-algal coating composition.
17. A water based anti-algal coating kit comprising:
a. a first container having a homogeneous dispersion of an anti-algal coating base comprising:
i. a fluid medium comprising:
- water in an amount in the range of 10 wt% to 30 wt% of the total amount of the coating base; and
- an organic fluid medium in an amount in the range of 10 wt% to 30 wt% of the total amount of the coating base, wherein the organic fluid medium comprises at least one compound selected from C2-C12 glycol, C2-C12 polyol, and C2-C12 polyether glycol and C1-C8 alcohol; and
ii. a sparsely water soluble component comprising at least one compound selected from the group consisting of copper (I) cyanide, copper (I) thiocynate and compound of formula (I), in an amount in the range of 40 to 95 wt% of the total amount of the coating base,
wherein the compound of formula (I) is represented as
Cu(PR1(z)R2(3-z))x(HOR3)yA
(I)
wherein,
A is selected from the group consisting of acetate (OAc), chloride (Cl), bromide (Br), iodide (I) and nitrate (NO3);
x is an integer ranging from 1 to 3, y is an integer ranging from 0 to 2, z is an integer ranging from 0 to 3, and x+y=3;
R1 is an alkyl or substituted alkyl; R2 is selected from the group consisting of phenyl, alkyl aryl, substituted phenyl, fused aryl phenyl, and substituted phenyl; and R3 is selected from the group consisting of alkyl, substituted alkyl or hydroxyalkyl;
wherein the particle size of the sparsely water soluble component in the anti-algal coating base is in the range of 5 to 25 µm; and
b. a second container having an emulsion of a polymeric binder;
wherein, the anti-algal coating base is mixed with the emulsion of the polymeric binder, prior to use, to impart anti-algal properties to the coating composition produced thereby.
18. The water based anti-algal coating kit as claimed in claim 17, wherein the compound of formula (I) is selected from the group consisting of Cu(PPh3)3Cl, Cu(PPh3)3Br, Cu(PPh3)3I, Cu(PPh3)3NO3, Cu(PPh3)2(CH3OH)(OAc), Cu(PPh3)2(C3H7OH)(OAc), Cu(PPh3)2(C4H9OH)(OAc), Cu(PPh3)2(C5H11OH)(OAc), Cu(PPh3)2(C6H13OH)(OAc), Cu(PPh3)2(C7H15OH)(OAc), Cu(PPh3)2(C8H17OH)(OAc), Cu(PPh3)2(C9H19OH)(OAc), Cu(PPh3)2(C10H21OH)(OAc), and Cu(PPh3)2(C12H25OH)(OAc).
19. The water based anti-algal coating kit as claimed in claim 17, wherein the compound of formula (I) is a complex of Cu(PPh3)2.OAc with at least one compound selected from ethylene glycol, di-ethylene glycol, tri-ethylene glycol, polyethylene glycol methyl ether, polyethylene glycol nonylphenyl ether, trimethylolpropane, neopentyl glycol, glycerol, cerenol, 2-ethoxyethanol, 2-butoxyethanol and propylene glycol n-propyl ether.
20. The water based anti-algal coating kit as claimed in claim 17, wherein the particle size of sparsely water component in the anti-algal coating base is in the range of 5 µm to 15 µm.
21. The water based anti-algal coating kit as claimed in claim 17, wherein the anti-algal coating base further comprises at least one surfactant, in an amount in the range of 5 wt% to 10 wt% of the total amount of the coating base.
22. The water based anti-algal coating kit as claimed in claim 17, wherein the anti-algal coating base further comprises calcium carbonate in an amount in the range of 5 wt% to 25 wt% of the total amount of the coating base.
23. The water based anti-algal coating kit as claimed in claim 17, wherein the anti-algal coating base further comprises china clay in an amount in the range of 5 wt% to 25 wt% of the total amount of the coating base.
24. A method for preparation of a water based anti-algal coating composition as claimed in claim 1, the method comprising:
• obtaining a slurry comprising an organic fluid medium and a sparsely water soluble component;
• adding water to slurry, and stirring at a speed of 200 to 800 rpm for a first predetermined time period to obtain an anti-algal coating base;
wherein the particle size of the sparsely water soluble component in the slurry is in the range of 5 to 25 µm.
wherein, the sparsely water soluble component comprises at least one compound selected from the group consisting of copper (I) cyanide, copper (I) thiocynate and compound of formula (I) is represented as
Cu(PR1(z)R2(3-z))x(HOR3)yA

(I)
wherein,
A is selected from the group consisting of acetate (OAc), chloride (Cl), bromide (Br), iodide (I) and nitrate (NO3);
x is an integer ranging from 1 to 3, y is an integer ranging from 0 to 2, z is an integer ranging from 0 to 3, and x+y=3;
R1 is an alkyl or substituted alkyl; R2 is selected from the group consisting of phenyl, alkyl aryl, substituted phenyl, fused aryl phenyl, and substituted phenyl; and R3 is selected from the group consisting of alkyl, substituted alkyl or hydroxyalkyl;
• adding to the anti-algal coating base, a polymeric binder, followed by stirring at a speed of 200 to 600 rpm for a first predetermined time period to obtain a the water based anti-algal coating composition,
wherein, the particle size of the polymeric binder is in the range of 0.05 to 1 µm.
25. The method as claimed in claim 24, wherein the organic fluid medium is at least one selected from the group consisting of C2-C12 glycol, C2-C12 polyol, and C2-C12 polyether glycol and C1-C8 alcohol.
26. The method as claimed in claim 24, wherein the first predetermined time period and second predetermined time period are independently in the range of 30 minutes to 60 minutes.
27. The method as claimed in claim 24, wherein the method further comprises the addition of at least one compound selected from the group consisting of a thickening agent, a defoamer, an amine, an extender, a pigment, an open time enhancer and a coalescing agent to the anti-algal coating base. , Description:FIELD
The present disclosure relates to a water based coating composition.
DEFINITIONS
As used in the present disclosure, the following words and phrases are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used to indicate otherwise.
The term anti-algal in the context of the present disclosure means a property of material / composition that inhibits and/ or restricts the growth of algae.
The term open time enhancer in the context of the present disclosure means an organic compound which increases open time of the coating composition. Open time is the time interval during which freshly applied coating can be blended with subsequently applied coating without the appearance of lack of uniformity.
BACKGROUND
Algal growth on indoor and outdoor surfaces is a major environmental concern affecting home, work and recreational environments. Not only algae can be unsightly on exposed surfaces, but also it can destroy wood, fiber and other materials if left untreated.
Conventionally, toxic chemicals, including the salts and oxides of heavy metals, have been added to coating compositions to prevent or inhibit algal growth. These chemicals to be effective should be introduced in large amounts in the coating compositions and thus, their high toxicity is apparent on the environment.
Alternatively, copper salts or copper derivatives alone or in combination with other material have been used as additives in anti-algal coating compositions.
However, with increasing environmental awareness, solvent based coating compositions are being replaced by water-based coating compositions. The conventional additives such as copper based salts and oxides are associated with drawbacks such as very intense colour, high water solubility, thereby restricting their use as an additive in the water based coating compositions.
There is, therefore, felt a need to provide water based coating composition that overcomes the above mentioned drawbacks of conventional anti-algal coating composition.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
It is an object of the present disclosure to provide a water based anti-algal coating composition.
It is another object of the present disclosure to provide a kit comprising (i) an anti-algal coating base and (ii) a polymeric binder.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
In one aspect, the present disclosure provides water based anti-algal coating composition as well as a method for preparation of the same. Water based anti-algal coating composition of the present disclosure comprises (i) an anti-algal coating base and (ii) a polymeric binder.
The anti-algal coating base comprises a sparsely water soluble component comprising at least one compound selected from the group consisting of copper (I) cyanide , copper (I) thiocynate and compound of formula (I) in an amount in the range of 1 wt% to 7 wt% of the total amount of the coating composition.
The compound of formula (I) is represented as
Cu(PR1(z)R2(3-z))x(HOR3)yA
(I)
wherein, A is selected from the group consisting of acetate (OAc), chloride (Cl), bromide (Br), iodide (I) and nitrate (NO3); x is an integer ranging from 1 to 3, y is an integer ranging from 0 to 2, z is an integer ranging from 0 to 3, and x+y=3; R1 is an alkyl or substituted alkyl; R2 is selected from the group consisting of phenyl, alkyl aryl, substituted phenyl, fused aryl phenyl, and substituted phenyl; and R3 is selected from the group consisting of alkyl, substituted alkyl or hydroxyalkyl.
Typically, the anti-algal coating base comprises (a) a fluid medium, wherein water is present in an amount in the range of 15 wt% to 50 wt% the total amount of the coating composition; and an organic fluid medium is present in an amount in the range of 1 wt% to 15 wt% the total amount of the coating composition. The organic fluid medium comprises at least one compound selected from C2-C12 glycol, C2-C12 polyol, C2-C12 polyether glycol and C1-C8 alcohol.
The sparsely water soluble component present in the anti-algal coating base has particle size in the range of 5 to 25 µm, preferably in the range of 5 µm to 15 µm.
Typically, the compound of formula (I) can be selected from the group consisting of Cu(PPh3)3Cl, Cu(PPh3)3Br, Cu(PPh3)3I, Cu(PPh3)3NO3, Cu(PPh3)2(CH3OH)(OAc), Cu(PPh3)2(C3H7OH)(OAc), Cu(PPh3)2(C4H9OH)(OAc), Cu(PPh3)2(C5H11OH)(OAc), Cu(PPh3)2(C6H13OH)(OAc), Cu(PPh3)2(C7H15OH)(OAc), Cu(PPh3)2(C8H17OH)(OAc), Cu(PPh3)2(C9H19OH)(OAc), Cu(PPh3)2(C10H21OH)(OAc), and Cu(PPh3)2(C12H25OH)(OAc).
In one embodiment, the compound of formula (I) is a complex of Cu(PPh3)2.OAc with at least one compound selected from ethylene glycol, di-ethylene glycol, tri-ethylene glycol, polyethylene glycol methyl ether, polyethylene glycol nonylphenyl ether, trimethylolpropane, neopentyl glycol, glycerol, cerenol, 2-ethoxyethanol, 2-butoxyethanol and propylene glycol n-propyl ether.
The polymeric binder is present in an amount in the range of 40 wt% to 65 wt% of the total amount of the coating composition. The binder is at least one acrylic polymer selected from the group consisting of waterborne carboxylated acrylic copolymers, hydroxy acrylic copolymers, acrylonitrile acrylic copolymers, carboxylated polyvinylchloride acrylic copolymers, and styrene acrylate copolymers.
The anti-algal coating base may comprise an organic open time enhancer in an amount in the range of 1 wt% to 2 wt% of the total amount of the coating composition, wherein the open time enhancer is at least one selected from the group consisting of polyol, polyether polyol, polyether polyol monoalkyl ether and polyether polyol polyalkyl ether.
The anti-algal coating base may comprise a pigment and an extender together in an amount in the range of 5 wt% to 30 wt% of the total amount of the coating composition.
The pigment is at least one selected from the group consisting of rutile titanium dioxide, anatase titanium dioxide, zinc oxide, leaded zinc oxide, zinc sulfide, lead titanate, antimony oxide, zirconium oxide, white lead, basic lead silicate, lithopone, titanated lithopone, titanium-barium pigment, titanium-calcium pigment and titanium-magnesium pigment.
The extender is at least one selected from the group consisting of calcium carbonate, talc, clays, dolomite, silica and silicates.
The anti-algal coating base may comprise a defoamer in an amount in the range of 0.1 wt% to 1 wt% of the total amount of the coating composition, wherein the defoamer is a substituted paraffin hydrocarbon.
The anti-algal coating base may comprise a thickening agent in an amount in the range of 0.2 wt% to 0.5 wt% of the total amount of the coating composition, wherein the thickening agent is at least one selected from the group consisting of cellulose and derivatives thereof, polyurea derivatives, polyetherurea derivatives, polyurethane derivatives and polyureaurethane derivatives.
The anti-algal coating base may comprise an amine, wherein the amine is at least one selected from the group consisting of ammonia, substituted amine and amino-alcohol.
The water based coating composition further comprises an organic opacifier in an amount in the range of 3 wt% to 20 wt% of the total amount of the coating composition.
Typically, the anti-algal coating base is a mill base comprising a sparsely water soluble component in an amount in the range of 20 to 63 wt% of the total amount of the coating base, an organic fluid medium in an amount in the range of 10 to 20 wt% of the total amount of the coating base, water in an amount in the range of 10 to 20 wt% of the total amount of the coating base, open time enhancer in an amount in the range of 1 to 2 wt% of the total amount of the coating base, defoamer in an amount in the range of 0.1 to 1 wt% of the total amount of the coating base, wetting agent in an amount in the range of 0.5 to 1.5 wt% of the total amount of the coating base, dispersing agent in an amount in the range of 0.2 to 1 wt% of the total amount of the coating base, and pigment and extender in an amount in the range of 15 to 35 wt% of the total amount of the coating base. The anti-algal mill base composition is adapted to mix with the polymeric binder to impart anti-algal properties to the coating composition produced thereby.
Typically, the water based anti-algal coating composition comprises a sparsely water soluble component in an amount in the range of 20 to 63 wt% of the total amount of the anti-algal coating composition, an organic fluid medium in an amount in the range of 10 to 20 wt% the total amount of the anti-algal coating composition, water in an amount in the range of 10 to 20 wt% the total amount of the anti-algal coating composition, open time enhancer in an amount in the range of 1 to 2 wt% the total amount of the anti-algal coating composition, defoamer in an amount in the range of 0.1 to 1 wt% the total amount of the anti-algal coating composition, wetting agent in an amount in the range of 0.5 to 1.5 wt% the total amount of the anti-algal coating composition, dispersing agent in an amount in the range of 0.2 to 1 wt% the total amount of the anti-algal coating composition, and pigment and extender in an amount in the range of 15 to 35 wt% the total amount of the anti-algal coating composition.
In second aspect, the present disclosure provides water based anti-algal coating kit, which comprises: a first container having a homogeneous dispersion of an anti-algal coating base and a second container having an emulsion of a polymeric binder, wherein the homogeneous dispersion of an anti-algal coating base is mixed with the emulsion of the polymeric binder, prior to use, to impart anti-algal properties to the coating composition produced thereby.
Typically, the anti-algal coating base comprises (a) a fluid medium, wherein water is present in an amount in the range of 10 wt% to 30 wt% of the total amount of the coating base; and an organic fluid medium is present in an amount in the range of 10 wt% to 30 wt% of the total amount of the coating base; and (b) a sparsely water soluble component, in an amount in the range of 40 to 95 wt% of the total amount of the coating base.
The sparsely water soluble component comprises at least one compound selected from the group consisting of copper (I) cyanide, copper (I) thiocynate and compound of formula (I). The compound of formula (I) is represent as
Cu(PR1(z)R2(3-z))x(HOR3)yA
(I)
wherein, A is selected from the group consisting of acetate (OAc), chloride (Cl), bromide (Br), iodide (I) and nitrate (NO3); x is an integer ranging from 1 to 3, y is an integer ranging from 0 to 2, z is an integer ranging from 0 to 3, and x+y=3; R1 is an alkyl or substituted alkyl; R2 is selected from the group consisting of phenyl, alkyl aryl, substituted phenyl, fused aryl phenyl, and substituted phenyl; and R3 is selected from the group consisting of alkyl, substituted alkyl or hydroxyalkyl.
The organic fluid medium comprises at least one compound selected from C2-C12 glycol, C2-C12 polyol, C2-C12 polyether glycol and C1-C8 alcohol.
Typically, the anti-algal coating base further comprises at least one surfactant in an amount in the range of 5 to 10 wt% of the total amount of the coating base.
The anti-algal coating base further comprises calcium carbonate in an amount in the range of 5 wt% to 25 wt% of the total amount of the coating base.
The anti-algal coating base further comprises china clay in an amount in the range of 5 wt% to 25 wt% of the total amount of the coating base.
In third aspect, the present disclosure provides a method for preparation of a water based anti-algal coating composition. The method comprises following steps:
Initially, slurry comprising an organic fluid medium and the sparsely water soluble component is prepared. Water is then added to slurry, followed by stirring at a speed of 200 to 800 rpm for a first predetermined time period to obtain an anti-algal coating base. The particle size of the sparsely water soluble component in the coating base is in the range of 5 to 25 µm. The polymeric binder is then added to the coating base, followed by stirring at a speed of 200 to 600 rpm for a second predetermined time period to obtain a the water based anti-algal coating composition. The particle size of the polymeric binder is in the range of 0.05 to 1 µm.
DETAILED DESCRIPTION
Algal growth on indoor and outdoor surfaces is a major environmental concern today. Algal growth on these surfaces can be prevented by the application of anti-algal coating compositions containing additives. The use of copper based compounds as additives is conventionally known. However, use of these copper based compounds in water based coating compositions is associated with drawbacks such as very intense colour, high water solubility, thereby restricting their use as an anti-algal additive in the water based coating compositions.
With increasing concerns over environmental safety, demand for the water based coating compositions has increased exponentially. The present disclosure envisages compounds which have less intense colour and which are amenable for use in the water based coating compositions and anti-algal water based coating compositions made therefrom.
In first aspect, the present disclosure provides water based anti-algal coating composition comprising (a) an anti-algal coating base and (b) a polymeric binder.
The anti-algal coating base comprises a sparsely water soluble component comprising at least one compound selected from the group consisting of copper (I) cyanide, copper (I) thiocyanate and compound of formula (I) in an amount in the range of 1 wt% to 7 wt% of the total amount of the coating composition.
The compound of formula (I) is represented as
Cu(PR1(z)R2(3-z))x(HOR3)yA
(I)
wherein, A is selected from the group consisting of acetate (OAc), chloride (Cl), bromide (Br), iodide (I) and nitrate (NO3); x is an integer ranging from 1 to 3, y is an integer ranging from 0 to 2, z is an integer ranging from 0 to 3, and x+y=3; R1 is an alkyl or substituted alkyl; R2 is selected from the group consisting of phenyl, alkyl aryl, substituted phenyl, fused aryl phenyl, and substituted phenyl; and R3 is selected from the group consisting of alkyl, substituted alkyl or hydroxyalkyl.
The sparsely water soluble component present in the anti-algal coating base has particle size in the range of 5 to 25 µm, preferably in the range of 5 µm to 15 µm.
In accordance with the embodiments of the present disclosure, compound of formula (I) can be selected from the group consisting of Cu(PPh3)3Cl, Cu(PPh3)3Br, Cu(PPh3)3I, Cu(PPh3)3NO3, Cu(PPh3)2(CH3OH)(OAc), Cu(PPh3)2(C3H7OH)(OAc), Cu(PPh3)2(C4H9OH)(OAc), Cu(PPh3)2(C5H11OH)(OAc), Cu(PPh3)2(C6H13OH)(OAc), Cu(PPh3)2(C7H15OH)(OAc), Cu(PPh3)2(C8H17OH)(OAc), Cu(PPh3)2(C9H19OH)(OAc), Cu(PPh3)2(C10H21OH)(OAc), and Cu(PPh3)2(C12H25OH)(OAc).
In accordance with the embodiments of the present disclosure, the compound of formula (I) is a complex of Cu(PPh3)2.OAc with at least one compound selected from ethylene glycol, di-ethylene glycol, tri-ethylene glycol, polyethylene glycol methyl ether, polyethylene glycol nonylphenyl ether, trimethylolpropane, neopentyl glycol, glycerol, cerenol, 2-ethoxyethanol, 2-butoxyethanol and propylene glycol n-propyl ether.
In accordance with the embodiments of the present disclosure, the anti-algal coating base comprises a fluid medium. The fluid medium comprises water in an amount in the range of 15 wt% to 50 wt% of the total amount of the coating composition; and an organic fluid medium in an amount in the range of 1 wt% to 15 wt% of the total amount of the coating composition. The organic fluid medium comprises at least one compound selected from C2-C12 glycol, C2-C12 polyol, C2-C12 polyether glycol and C1-C8 alcohol. In accordance with the present disclosure, the organic fluid medium present in anti-algal coating base also acts as open time enhancer for anti-algal coating composition obtained therefrom.
In accordance with the embodiments of the present disclosure, the binder is at least one acrylic polymer selected from the group consisting of waterborne carboxylated acrylic copolymers, hydroxy acrylic copolymers, acrylonitrile acrylic copolymers, carboxylated polyvinylchloride acrylic copolymers, and styrene acrylate copolymers.
In the compound of the formula (I), z = 0, y = 0 and R2 = phenyl (Ph), and the compound is copper-triphenylphosphine complex and it is represented by formula II.
Cu(PPh3)xA
(II)
wherein, A is selected from the group consisting of acetate (OAc), chloride (Cl), and bromide (Br); and x is an integer ranging from 2 to 3.
In accordance with one exemplary embodiment of the present disclosure, the compound is copper-triphenylphosphine chloride [CAS No. 15709-76-9], which is represented by formula III.
Cu(PPh3)3(Cl)
(III)
In accordance with second exemplary embodiment of the present disclosure, the compound is copper-triphenylphosphine bromide [CAS No. 15709-74-7], which is represented by formula IV.
Cu(PPh3)3(Br)
(IV)
In the compound of the formula (I), z = 0, y = 1 and R2 = phenyl (Ph), R3 = methyl, the compound is copper-triphenylphosphine acetate, which is represented by formula V.
Cu(PPh3)2(MeOH)(OAc)
(V)
The anti-algal coating base can further comprise a pigment and an extender together in an amount in the range of 5 wt% to 30 wt% of the total amount of the coating composition.
The pigment is at least one selected from the group consisting of rutile titanium dioxide, anatase titanium dioxide, zinc oxide, leaded zinc oxide, zinc sulfide, lead titanate, antimony oxide, zirconium oxide, white lead, basic lead silicate, lithopone, titanated lithopone, titanium-barium pigment, titanium-calcium pigment and titanium-magnesium pigment.
The extender is at least one selected from the group consisting of calcium carbonate, talc, clays, dolomite, silica and silicates.
The anti-algal coating base can further comprise a defoamer in an amount in the range of 0.1 wt% to 1 wt% of the total amount of the coating composition. The defoamer is a substituted paraffin hydrocarbon.
The anti-algal coating base can further comprise an organic open time enhancer in an amount in the range of 1 wt% to 2 wt% of the total amount of the coating composition. The open time enhancer is at least one selected from the group consisting of polyol and polyether.
The water based coating base can further comprise a coalescing agent in an amount in the range of 0.1 to 0.5 wt% of the total amount of the coating composition. The coalescing agent is at least one selected from the group consisting of polyol and substituted alcohol.
The water based coating base can further comprise a thickening agent in an amount in the range of 0.2 to 0.5 wt% of the total amount of the coating base. The thickening agent is at least one selected from the group consisting of cellulose and derivatives thereof, polyurea derivatives, polyetherurea derivatives, polyurethane derivatives and polyureaurethane derivatives.
The water based coating base further comprises an amine, wherein the amine is at least one selected from the group consisting of ammonia, substituted amine and amino-alcohol.
In accordance with one embodiment of the present disclosure, the anti-algal coating base is a mill base comprising a sparsely water soluble component in an amount in the range of 20 to 63 wt% of the total amount of the coating base, an organic fluid medium in an amount in the range of 10 to 20 wt% of the total amount of the coating base, water in an amount in the range of 10 to 20 wt% of the total amount of the coating base, open time enhancer in an amount in the range of 1 to 2 wt% of the total amount of the coating base, defoamer in an amount in the range of 0.1 to 1 wt% of the total amount of the coating base, wetting agent in an amount in the range of 0.5 to 1.5 wt% of the total amount of the coating base, dispersing agent in an amount in the range of 0.2 to 1 wt% of the total amount of the coating base, and pigment and extender in an amount in the range of 15 to 35 wt% of the total amount of the coating base. The anti-algal mill base composition is adapted to mix with the polymeric binder to impart anti-algal properties to the coating composition produced thereby.
In accordance with an exemplary embodiment of the present disclosure, the mill base comprises a sparsely water soluble component in an amount in the range of 7 wt% of the total amount of the coating base, an organic fluid medium in an amount in the range of 30 wt% of the total amount of the coating base, water in an amount in the range of 30 wt% of the total amount of the coating base, open time enhancer in an amount in the range of 1.5 wt% of the total amount of the coating base, defoamer in an amount in the range of 0.5 wt% of the total amount of the coating base, wetting agent in an amount in the range of 0.5 wt% of the total amount of the coating base, dispersing agent in an amount in the range of 0.5 wt% of the total amount of the coating base, and pigment and extender in an amount in the range of 30 wt% of the total amount of the coating base.
In accordance with another embodiment the present disclosure the coating composition is emulsion composition comprising water in an amount in the range of 20 to 40 wt% of the total amount of the coating composition, an organic fluid medium in the range of 1 to 2 wt% of the total amount of the coating composition, a polymeric binder in an amount in the range of 40 to 70 wt% of the total amount of the coating composition, a sparsely water soluble component of formula (I), in an amount in the range of 3 to 10 wt% of the total amount of the coating composition, a wetting agent in an amount in the range of 0.5 to 1.5 wt% of the total amount of the coating composition, a dispersing agent in an amount in the range of 0.2 to 1 wt% of the total amount of the coating composition and a defoamer in an amount in the range of 0.1 to 1 wt% of the total amount of the coating composition.
The anti-algal water based coating composition of the present disclosure exhibit enhanced efficacy of algaecidal activity without hampering stability and its other performances.
In second aspect, the present disclosure provides a water based anti-algal coating kit. The kit comprises (a) a first container having a homogeneous dispersion of an anti-algal coating base; and (b) a second container having an emulsion of a polymeric binder. The homogeneous dispersion of the anti-algal coating base is mixed with the emulsion of the polymeric binder, prior to use, to impart anti-algal properties to the coating composition produced thereby.
In accordance with the present disclosure, the anti-algal coating base comprises a sparsely water soluble component comprising at least one compound selected from the group consisting of copper (I) cyanide, copper (I) thiocynate and compound of formula (I) in an amount in the range of 40 wt% to 95 wt% of the total amount of the coating base. The compound of formula (I) is represented as
Cu(PR1(z)R2(3-z))x(HOR3)yA
(I)
wherein, A is selected from the group consisting of acetate (OAc), chloride (Cl), bromide (Br), iodide (I) and nitrate (NO3); x is an integer ranging from 1 to 3, y is an integer ranging from 0 to 2, z is an integer ranging from 0 to 3, and x+y=3; R1 is an alkyl or substituted alkyl; R2 is selected from the group consisting of phenyl, alkyl aryl, substituted phenyl, fused aryl phenyl, and substituted phenyl; and R3 is selected from the group consisting of alkyl, substituted alkyl or hydroxyalkyl.
In accordance with the present disclosure, the anti-algal coating base comprises a fluid medium comprising water in an amount in the range of 10 wt% to 30 wt% of the total amount of the coating base and an organic fluid medium in an amount in the range of 10 wt% to 30 wt% of the total amount of the coating base. The organic fluid medium comprises at least one compound selected from C2-C12 glycol, C2-C12 polyol, C2-C12 polyether glycol and C1-C8 alcohol.
In accordance with the present disclosure, the anti-algal coating base can further comprise at least one surfactant, in an amount in the range of 5 to 10 wt% of the total amount of the coating base.
In accordance with the present disclosure, the anti-algal coating base can further comprise calcium carbonate in an amount in the range of 5 wt% to 25 wt% of the total amount of the coating base.
In accordance with the present disclosure, the anti-algal coating base can further comprise china clay in an amount in the range of 5 wt% to 25 wt% of the total amount of the coating base.
In third aspect, the present disclosure provides a method for preparation of a water based anti-algal coating composition. The method comprises following steps:
• Initially, a slurry comprising an organic fluid medium and a sparsely water soluble component is obtained. Water is added to slurry followed by stirring at a speed of 200 to 800 rpm for a first predetermined time period to obtain an anti-algal coating base; wherein the particle size of sparsely water soluble component present in the slurry is in the range of 5 to 25 µm, preferably in the range of 5 to 15 µm.
The sparsely water soluble component comprises at least one compound selected from the group consisting of copper (I) cyanide, copper (I) thiocynate and compound of formula (I). The compound of formula (I) is represented as
Cu(PR1(z)R2(3-z))x(HOR3)yA
(I)
wherein, A is selected from the group consisting of acetate (OAc), chloride (Cl), bromide (Br), iodide (I) and nitrate (NO3); x is an integer ranging from 1 to 3, y is an integer ranging from 0 to 2, z is an integer ranging from 0 to 3, and x+y=3; R1 is an alkyl or substituted alkyl; R2 is selected from the group consisting of phenyl, alkyl aryl, substituted phenyl, fused aryl phenyl, and substituted phenyl; and R3 is selected from the group consisting of alkyl, substituted alkyl or hydroxyalkyl.
• A polymeric binder is then added to coating base in an emulsion form under stirring at speed in the range of 200 to 400 rpm. The polymeric binder has particle size in the range of 0.05 to 1 µm. Optionally, opacifier is added, followed by stirring at a speed in the range of 200 to 600 rpm for a first predetermined time period to obtain a water based coating composition.
In accordance with the present disclosure, the organic fluid medium is selected from the group consisting of C2-C12 glycol, C2-C12 polyol, C2-C12 polyether glycol and C1-C8 alcohol. The organic fluid medium facilitates the grinding of the sparsely water soluble component to particle size in the range of 5 to 25 µm.
In accordance with the method of the present disclosure, the first predetermined time period and second predetermined time periods are independently in the range of 30 minutes to 60 minutes.
The method of the present disclosure further comprises the addition of at least one compound selected from the group consisting of a thickening agent, a defoamer, an amine, an extender, a pigment, an open time enhancer and a coalescing agent, to the anti-algal coating base.
The present disclosure further provides a method for obtaining slurry comprising an organic fluid medium and a sparsely water soluble component. In the one aspect, the method comprises following steps:
• A reactor is charged with copper (I) compound and phosphine compound in at least one organic fluid medium and the resultant mixture is refluxed for a pre-determined time period to obtain a product mixture.
• After completion of the reaction, the product mixture is cooled to room temperature to obtain slurry comprising the compound of formula (I) and the organic fluid medium. The particle size of the so obtained compound of formula (I) is in the range of 5 to 25 µm.
In accordance with the present disclosure, the copper (I) compound is at least one selected from the group consisting of copper (I) chloride, copper (I) bromide, and copper (I) acetate.
In an exemplary embodiment of the present disclosure, the phosphine compound is triphenyl phosphine.
In an exemplary embodiment of the present disclosure, the organic fluid medium is at least one selected from C2-C12 glycol, C2-C12 polyol, C2-C12 polyether glycol and C1-C8 alcohol.
In accordance with the present disclosure, the organic fluid medium facilitates in obtaining the compound of formula (I) having the particle size in the range of 5 to 25 µm, on cooling the product mixture. It was observed that when organic fluid medium selected from C1-C8 alcohol, C2-C12 glycol, C2-C12 polyol, C2-C12 polyether glycol was used, cooling of the product mixture results in crystallization or precipitation of compound of formula (I) in the form of particles having particle size in the range of 5 to 25 µm.
In another aspect, the method comprises following steps:
• charging the reactor with a sparsely water soluble component, followed by addition of an organic fluid medium. The mixture is stirred and grinded at a speed in the range of 450 to 550 rpm for a period of time in the range of 10 minutes to 100 minutes to obtain resultant mixture. The particle size of a sparsely water soluble component in the resultant mixture is in the range of 5 to 25 µm, preferably 15 µm.
In accordance with the present disclosure, the sparsely water soluble component comprises at least one compound selected from the group consisting of copper (I) cyanide and copper (I) thiocynate.
The Hegman gauge is widely used for determining the fineness of a coating’s grind and thereby acceptability as an architectural topcoat. Coarse coating compositions reduce color uniformity, gloss, and opacity. It is observed that the coating compositions with Hegman gauge value of less than 5, results into failure in Zone of inhibition test against algal culture test. The water based coating compositions obtained by the process of the present disclosure are tested on Hegman gauge and are found to have Hegman gauge value of 5 or more. Therefore the water based coating compositions of the present disclosure are acceptable as architectural topcoat.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial scale.
EXPERIMENTAL DETAILS
Example-1: Preparation of a water based anti-algal coating composition
General procedure:
Initially water, defoamer, wetting agent, and dispersing agent were mixed in the high speed dispenser at a speed of 500 rpm to form a suspension. Pigment and extender were added to the suspension and the resultant mixture was stirred at a speed of 800 rpm for 45 minutes. A slurry of a sparsely water soluble component in organic fluid medium was added, followed by grinding to obtain an anti-algal coating base.
The speed of dispenser was reduced to 500 rpm and polymeric binder in the form of emulsion was added, followed by stirring to obtain a water based coating composition.
The water based anti-algal coating compositions prepared by the process of the present disclosure were tested on Hegman gauge. The Hegman gauge is widely used for determining the fineness of a coating’s grind.

Experiment 1: Preparation of a mill base composition:
The general procedure as described above was used for the preparation of the mill base composition. The chemical composition of the mill base composition is given in table-1 below.
Table-1
Components
wt% Composition

Compound of Formula (I)* 7.0
Organic fluid medium 30
Water 30
Defoamer 0.5
Wetting agent 0.5
Dispersing agent 0.5
Extender 15.0
Open time enhancer 1.5
Pigment 15.0
* particle size of 15 µm
Experiment-2: Preparation of a water based anti-algal coating composition comprising copper triphenyl phosphine chloride complex [Cu(PPh3)3Cl]
General procedure as described herein above was followed. The compound of formula (I) used was copper triphenyl phosphine chloride complex [Cu(PPh3)3Cl].
Two water based anti-algal coating compositions having the chemical compositions provided in Table -2 were prepared.
Table-2:
Components

wt% Composition 1 Composition 2
Water 21.25 21.25
Polymeric binder$ in emulsion form 42.60 42.60
Cu(PPh3)3Cl* 7.0 1.5
Defoamer 0.25 0.25
Wetting agent 0.5 0.5
Dispersing agent 0.4 0.4
Extender 6.0 11.5
Open time enhancer 1.0 1.0
pigment 21.0 21.0
$ particle size of 0.5 µm, * particle size of 15 µm

Compositions 1, and 2 prepared by the process of the present disclosure were found to be stable and were able to either restrict or inhibit algal growth on the surface, on which they are applied.
Further, the compositions 1, and 2 were found to have Hegman gauge value of 5 or more.
Experiment-3: Preparation of a water based anti-algal coating composition comprising copper triphenyl phosphine bromide complex [Cu(PPh3)3Br]
General procedure as described herein above was followed. The compound of formula (I) used was copper triphenyl phosphine Bromide complex [Cu(PPh3)3Br].
Two water based anti-algal coating composition having chemical compositions provided in Table -3 were prepared.
Table-3:
Components

wt% Composition 3 Composition 4
Water 21.25 21.25
Polymeric binder$ in emulsion form 42.60 42.60
Cu(PPh3)3Br* 7.0 1.5
Defoamer 0.25 0.25
Wetting agent 0.5 0.5
Dispersing agent 0.4 0.4
Extender 6.0 11.5
Open time enhancer 1.0 1.0
pigment 21.0 21.0
$ particle size of 0.5 µm, * particle size of 15 µm
Compositions 3, and 4 prepared by the process of the present disclosure were found to be stable and were able to either restrict or inhibit algal growth on the surface, on which they are applied.
Further, the compositions 3, and 4 were found to have Hegman gauge value of 5 or more.
Experiment-4: Preparation of a water based anti-algal coating composition comprising copper triphenyl phosphine acetate complex [Cu(PPh3)2 (MeOH)(OAc)]
General procedure as described herein above was followed. The compound of formula (I) used was copper triphenyl phosphine acetate complex [Cu(PPh3)2(MeOH)(OAc)].
Two water based anti-algal coating composition having chemical compositions provided in Table -4 were prepared.
Table-4:
Components

wt% Composition 5 Composition 6
Water 21.25 21.25
Polymeric binder$ in emulsion form 42.60 42.60
Cu(PPh3)3Cl* 7.0 1.5
Defoamer 0.25 0.25
Wetting agent 0.5 0.5
Dispersing agent 0.4 0.4
Extender 6.0 11.5
Open time enhancer 1.0 1.0
pigment 21.0 21.0
$ particle size of 0.5 µm, * particle size of 15 µm
Compositions 5, and 6 prepared by the process of the present disclosure were found to be stable and were able to either restrict or inhibit algal growth on the surface, on which they are applied.
Further, the compositions 5, and 6 were found to have Hegman gauge value of 5 or more.
Example-2: Preparation of a water based anti-algal clear coat
General procedure as described in example 1 was followed except that pigment was not added in the coating composition. The water based anti-algal clear coat having the chemical composition given in table -5 was prepared.
Table-5
Components

wt% Composition 7

Water 20.25
Polymeric binder$ in emulsion form 50.0
Cu(PPh3)3Br* 7.0
Defoamer 0.25
Wetting agent 0.5
Dispersing agent 0.4
Extender 21.0
Open time enhancer 1.0
$ particle size of 0.5 µm, * particle size of 15 µm
The anti-algal clear coat was found to have Hegman gauge value of 5 or more.
Example-3: Preparation of an emulsion composition
General procedure as described in example 1 was followed except that pigment and extender was not added in the coating composition. The emulsion composition having the chemical composition given in table -6 was prepared.
Table-6
Components

wt% Composition 9

Water 32.5
Polymeric binder$ in emulsion form 60
Cu(PPh3)3Br* 5
Defoamer 0.3
Wetting agent 1.0
Dispersing agent 0.5
Open time enhancer 1.0
$ particle size of 0.5 µm, * particle size of 15 µm
The anti-algal clear coat was found to have Hegman gauge value of 5 or more.
Example-4: Anti-algal activity of the water based anti-algal coating compositions.
The anti-algal activity of the water based anti-algal coating compositions 1 to 6 prepared in example 1 was calculated by anti-algal chamber test provided below.
The results of anti-algal chamber test are provided herein below in Table-7:
Table-7:
Coating compositions Calculated Cu % Bio Assay Results Anti-algal Chamber Test performance rating after 30 days.* Merit
Ranking of Anti-algal Chamber Test performance rating after 30 days.
Blank Sample 0 No ZOI with GOPF 0 5
Composition 1 0.5 No ZOI with NGOPF 7 2
Composition 2 0.1 No ZOI with NGOPF 7 2
Composition 3 0.5 No ZOI with NGOPF 8 1
Composition 4 0.1 No ZOI with GOPF 7 2
Composition 5 0.5 No ZOI with NGOPF 1 4
Composition 6 0.1 No ZOI with NGOPF 6 3

ZOI: Zone of inhibition;
GOPF: Growth on paint film; and
NGOPF: No growth on paint film.
*For Chamber test rating 0 being the lowest and 10 being the highest.
It is evident from table-7 that the coating composition prepared by the process of the present disclosure, either restrict or inhibit algal growth.
Example-5: Preparation of anti-algal coating kit
The anti-algal coating kit comprises two parts.
1. A first container having a homogeneous dispersion of an anti-algal coating base; and
2. A second container having an emulsion of a polymeric binder.
Experiment-5: Preparation of a homogeneous dispersion of an anti-algal coating base
General procedure:
Initially water, defoamer, wetting agent, and dispersing agent were mixed in the high speed dispenser at a speed of 500 rpm to form a suspension. Pigment and extender were added to the suspension and the resultant mixture was stirred at a speed of 800 rpm for 45 minutes. The sparsely water soluble component in the form of slurry in organic fluid medium was added, followed by stirring to obtain a water based coating base.
Four different anti-algal coating bases having varying chemical compositions were prepared. The contents of anti-algal coating base 1 to 4 are summarized below in Table-8.

Table-8:
Additive Compound of Formula (I)
wt % Surfactant

wt % Calcium carbonate
wt % Glycerol

wt % Water

wt %
1 65.0 10.0 10.0 15.0 0.0
2 60.0 15.0 10.0 5.0 10.0
3 60.0 5.0 0.0 35.0 0.0
4 60.0 10.0 0.0 15.0 15.0

The anti-algal coating bases prepared by the process of the present disclosure are stable.
Example-6: Preparation of compound of formula (I)
Experiment-7: Preparation of copper triphenylphosphine bromide complex
Cu(PPh3)3Br
Initially, the reactor was charged with copper bromide (11 g) and tri-phenyl phosphine (56 g) in glycerol (250 mL) and the content was refluxed for 30 min. After completion of reaction, white solid formed. The reaction mixture was cooled to room temperature to obtain slurry of copper triphenylphosphine bromide complex in glycerol. The particle size of so obtained copper triphenylphosphine bromide is 15 µm.
Experiment-8: Preparation of copper triphenylphosphine bromide complex
Cu(PPh3)3Cl
Similar experimental procedure as described in experiment 6 was followed except copper bromide was replaced with copper chloride.
Experiment-9: Preparation of copper triphenylphosphine bromide complex
Cu(PPh3)2(MeOH)(OAc)
Similar experimental procedure as described in experiment 6 was followed except copper bromide was replaced with copper acetate and glycerol was replaced with methanol.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of:
• a water based anti-algal coating composition comprising:
? an anti-algal additive which comprises copper triphenylphosphine complex that imparts anti-algal activity to coating composition; and
• a water based anti-algal coating kit comprising:
? a water based coating base contained in first container; and
? an anti-algal additive in second container.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the composition of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.