GB2501079A

GB2501079A - Dry powder paint binder

Info

Publication number: GB2501079A
Application number: GB1206328.5A
Authority: GB
Inventors: Stuart Ross Rhind Harling
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-04-10
Filing date: 2012-04-10
Publication date: 2013-10-16
Also published as: GB201206328D0

Abstract

A method of forming a dry powder paint binder from milk or plant proteins and other natural materials comprises a shearing operation to produce consistent, homogeneous and uniform particles. The binder may be mixed with pigments and mineral fillers (such as kaolin, magnesium silicate and calcium carbonate) to form a dry powder paint. Other ingredients may include preservatives (such as zinc oxide and potassium sorbate), fungicides, antifoaming agents (such as silica sand), cellulosic thickeners, polysaccharide dispersants, and activators (such as calcium hydroxide, ammonium carbonate, and borax). The dry powder paint may contain 15-30% binder, 50-70% filler, 0.5-20% pigment, 1-10% activator, 0.5-2% preservative, and 0.05-1% dispersant. In a preferred method, the shearing operation uses a high speed horizontal blade for a period of 30-300 seconds to produce particles of 60-80 microns. Further methods of forming the binder and the dry powder paint as well as a liquid paint containing same are also disclosed.

Description

Title: Improved Paint Binder

Background:

This invention relates to the fields of architectural or decorative coatings and paints in general and, more particularly, to binder compositions made from protein and other natural materials in dry powder form and improved methods for making the same.

Even more particularly the present invention relates to such binders within a dry powder paint formulation as will combine with a variety of liquids and other materials to achieve a range of different surface finishes, textures and appearances.

Typically conventional paints are manufactured in liquid form to a pre- determined finish and texture. These paints comprise a binder (a glue-like' material), fillers, pigment and solvent liquids which are subsequently packaged for customers within a metal or plastic container. The ingredients of such paints typically include a number of materials derived from petrochemica Is and other big h-carbon sources, many of which are considered hazardous to the environment and/or human life.

Conventional liquid paint is typically blended from a combination of all ingredients in a large tank (500÷ litres) and manufactured through a cutting process known as high-shear dispersion which can take up to 12 hours or more. Such manufacture is a high energy process and the resultant prod uct is heavy, difficult and costly to store and tra nsport.

The manufacture, transportation, storage and disposal of conventional liquid paint products also poses additional emission risks, costs and hazards for the distributors, users and the waste disposal authorities of such products.

Consequently there is a need for paints that can be manufactured and safely distributed in lightweight dry-powder forms. Moreover ones which do not contain hazardous ingredients and do not constitute a health risk for humans, the environment or the atmosphere, and which preferably have little or none of the transportation and disposal problems associated with conventional liquid paints.

It has long been known that tolerable non-toxic paints can be produced from a range of earth minerals and natural materials in a dry powder form to be mixed by the user with water and/or other liquids in the amounts req ui red at time of use.

These natural' paints, often include milk and plant proteins, in liquid or dry forms, and are of a ncient origins. Such pai nts in dry-powder form, wherein the binder is the most critical component, have been variously referred to as milk paints; casein paints; casein-lime distempers; calcimines; etc. A number of formulations for such dry powder paints have been granted patents in various countries over a period of many years and these have been reviewed in pursuance of this application, in particular US 2636829 A and GB 2443026 B. Furthermore such dry-powder paints would be advantageous to users and others if their packaging and any residues could be easily disposed of with minimal detrimental impact on the environment, atmosphere, humans and other life forms.

Although produced in dry powder form, many of these paints still require a considerable degree of skill in the art to produce satisfactory results by typical consumers when compared with the convenience of conventional ready-to-use liquid paints.

Therefore there are benefits from making measurable improvements to such dry-powder paint products which will result in easier and more tolerant mixing with liquids; better adherence; with more consistent finish; and lower energy consumption in the manufacture and usage of such products.

Description of Invention

This invention relates to a novel development in the manufacture of powdered paint binder compositions made from protein and natural materials, as well as the incorporation such binder with fillers, pigments and other materials in the production of a dry-powder paint, to be mixed with liq uids in order to form a usable and durable architectural and decorative coating material.

Despite the environmental benefits of such dry-powder paint products, there are, from customer experience and market knowledge, recognised issues concerning the perceived performance and consumer acceptance of such products.

From detailed investigation it is known these issues arise from: * Lack of consistent mixing of materials and variable thickening time.

* Inconsistent particle size leading to powder flotation' of smaller particles and different dissolving rates in water and other liquids.

* The effects of exposure of proteins within milk and plant materials to excessive heat during certain grinding and particle reduction procedures.

* The effects of exposure of dry-powder paint ingredients to moisture and/or humid atmosphere.

* The surface oxidisation of oxide pigments and other colouring components which prevent intimate combination with other materials to produce full colour depth.

It is known that proteins of both plant and milk sources together with naturally derived polysaccharides, lecithin and cellulose materials have certain characteristics which can be damaged or modified through the action of heat, pressure and moisture.

Accepted and known industry practice in the processing of powders and for reducing particle sizes involves grinding or milling of one particular type of material at a time. Grinding is thus defined as "to crush, pulverize, or reduce to powder by friction, especially by rubbing between two hard surfaces." The established milling technology used for powder particle reduction thus relies on the action of striking particular materials between two harder surfaces and includes: Ball Mills, Conical Mills, Hammer Mills, Edge Mill, Planetary Mill, Roller Mills, Wiley Mills, Disk Mills and Plate Mills.

Inevitably the mechanical actions involved all produce friction, pressure and heat which are detrimental to the combined ingredients of natural dry-powder paints. The extended periods of such processing can also expose the materials to atmospheric moisture which can degrade the final product performance.

In addition the majority of mechanical milling technologies rely on screens to separate out particles of particular sizes. In the nature of the soft and sticky ingredients included in such nature I' paints, these screens can soon become blocked and milling has to cease completely whilst a protracted clean down takes place.

In the powder processing industry certain adaptations to the established procedures have been made in order to improve conventional milling technology when processing batches of sort materials. One form is cryogenic' milling where the particular material to be processed is either frozen or liquid nitrogen is introduced into the milling chamber in order to keep temperatures at low levels. A second is air-jet' milling where pa rticles interact and collide with each other in powerful air strea ms.

Both of these milling adaptations have proved unsatisfactory in the processing of the combined ingredients found in dry-powder binders and paints for a variety of reasons including: moisture retention, energy cost, pressure damage, heat generation, environmental impact or the time req ui red to process cost effective qua ntities of prod uct.

To address the issues described above a new process for reducing a dry powder binder particle size through cutting and slicing (shearing) actions has been investigated and developed. It is found that the action of shearing the materials described imposes less pressure and generates less friction and heat than other particle reduction methods.

In various trials, it was found that the pa rticle size of natural' ingredients could be reduced through the shearing interaction of specially developed horizontally mounted blades rotated at speeds of between 1500 and 3000 rpm through a batch of the combined materials.

Advantages of this invention: It was found that the action of horizontally mounted blades through a dry powder paint birder composition induces a strong vortex effect within the combined materials which ensured thorough mixing of all ingredients and presentation to the cutting edges of the blades. The cooling affect of the vortex airstream allows the processing period to be shortened and without generating sufficient heat to cause damage to the protein materials.

With such a device, I have found that it possible to produce a homogeneous mixture of the ingredients within a natural' paint binder and to reduce the particles sizes consistently and uniformly.

I have found that the shearing and cutting action of such horizontally mounted blades can reduce the time required to reduce particle size by up to 75%.

I have also found that the particles are uniformly reduced and can pass through the mesh of a sieve with 200 holes per square inch.

I have found that, with a sufficiently powerful motor to drive the blades of such horizontal cutter blades the energy consumed is reduced over alternative grinding methods by over 25%.

I have found that the shearing action can be induced to combine other particles with the paint binder in an equally uniform and homogeneous ma nner.

I have found that the colour intensity of natu ral earth and oxide pigments is enhanced by the shearing action of such processing and therefore the amount of material required to achieve certain colours can be reduced by up to 2.5%.

I have found that a resulting protein binder composition will combine and thicken with water at a 10 degree Celsius lower temperature than previously necessary thereby resulting in reduced energy requirements and mixing time by the user of the product.

I have found that the resulting paint product produces a paint which has 15% improved adhesion properties when measured by the cross hatch adhesion test.

Procedure: Weigh and place all the ingredients of a powdered paint binder in a lidded container with modified horizontal cutting blades arranged in an isle of man' configuration.

Subject the mixture to a series of shearing processes for approximately seconds or less or until all are intimately mixed and cut to a size of between 65-70 microns (200 mesh).

Allow the resulting mixture to cool to ambient temperature, add in remaining components of a powdered paint together with colouring pigments, and repeat the process for 60 and 300 seconds.

Claims

Claims: What is claimed is: 1. The consistent, homogeneous and uniform particle production of a dry powder paint binder from milk and plant proteins with other natural materials through a shearing process driven by electrical, mechanical or other means.
2. Production of a paint binder composition according to claim 1 further comprising mineral filler, colouring pigments and other materials to produce a dry powder paint.
3. Production of a paint binder and powder paint composition according to claim 1 and 2 further comprising a preservative and fungicide.
4. Production of a paint binder and powder paint composition according to claim 3 wherein the preservative is selected from zinc oxide and potassium sorbate.
5. Production of a paint binder and powder paint composition according to any one of claims 1 to 4 further comprising an antifoaming ingredient.
6. Production of a paint binder and powder paint composition according to claim 5 wherein the antifoaming ingredient is selected from silica sand.
7. Production of a paint binder and powder paint composition according to any one of claims 1 to 6 further comprising a thickening ingredient.
8. Production of a paint binder and powder paint composition according to claim 7 wherein the thickening ingredient is selected from cellulose fibres and cellulose material.
9. Production of a paint binder and powder paint composition according to any one of claims 1 to 6 further comprising a d isp e rs a n t.
10. Production of a paint binder and powder paint composition according to claim 7 wherein the dispersant is a polysaccharide substance.
11. Production of a dry powder paint comprising a paint binder composition according to any one of claims 1 to 8 and further comprising a filler mixture.
12, Production of a dry powder paint according to claim 9 wherein the filler mixture is selected from kaolin, magnesium silicate and calcium carbonate.
13. Production of a dry powder paint comprising a paint binder composition according to any one of claims 1 to 10 and further comprising an activator.
14. Production of a dry powder paint according to claim 11 wherein the activator is selected from calcium hydroxide, am moni u m carbonate and borax.
15. Production of a dry powder paint comprising a paint binder composition according to any one of claims 1 to 12 and further comprising one or more pigments.
16. Production of a dry powder paint according to claim 14 wherein the pigment(s) is(are) selected from organic and inorganic pigments, och res, oxides, dioxides, urn bers, vegeta ble dyes and other naturally occurring earth pigments.
17.A dry powder paint according to claims 2 to 14 wherein 15 to about 30% of said dry powder paint is binder corn pound.
18.A dry powder paint according to claim 2 to 14 wherein 50 to about 70% of said dry powder paint is filler materials.
19.A dry powder paint according to claims 2 to 14 wherein 0.5 to about 20% of said dry powder paint is pigment material.
20.A dry powder paint according to claims 2 to 14 wherein ito about 10% of said dry powder paint is activating material.
21.A dry powder paint according to claims 2-14 wherein 0.5 to about 2°/a of said dry powder paint is preservative material.
22.A dry powder paint according to claim 2-14 wherein 0.05 to about 1% of said dry powder paint is dispersant material.
23.A method of manufacturing said specific paint binder composition for use in manufacturing the said dry powder paint comprising the steps of: providing casein protein, providing soy lecithin, providing dextrin; providing cellulose fibres and combining and subsequently shearing particles to a fineness of between 60-80 microns through a horizontal high speed shearing operation of not less than 30 and not more than 300 seconds duration.
24.A method or manufacturing said dry powder paint comprising the steps of: providing said specific binder compound; providing filler mixture; providing pigment; providing preservative; providing anti-foaming materials; providing dispersant; providing activator and processing thoroug hly in a vortex creating horizontal cutter for a period of not less than 60 and rot more than 300 seconds whereas the finished material will pass through a mesh containing 200 holes per square inch.
25.A liquid paint comprising the paint binder composition and dry powder paint according to any claims 1 to 23 and one or more liquids.
26.A liquid paint according to claim 23, wherein the liquid(s) is (are) selected from: water; beeswax emulsion; other wax emulsions; gums; glues; linseed oil; safflower oil; sunflower oil; tung oil.
27.A method comprising the mixing procedure of paint hinder and dry powder paint compositions produced according to claims 2-23 with ore or more liquids.
28.A method comprising applying the liquid paint according to claims 23 and 24 to a surface.