ES2887422B2 - Procedure for obtaining paints with anti-corrosive and thermal insulation properties and product obtained - Google Patents

Description

DESCRIPTION

Procedure for obtaining paints with anti-corrosive and thermal insulation properties and product obtained

TECHNICAL SECTOR

The present invention relates to a process that has been specially designed to improve the performance of certain paints.

The invention falls within the sectors of anticorrosive and thermal insulation treatments. The purpose is to add a filler for paints from the micronization of olive and/or palm pits, which will provide the paints with extraordinary physical-chemical characteristics, for use as a protective coating for metal surfaces, in applications such as: bridges , steel structures exposed to the elements, buildings, automobile industry, aeronautical industry, maritime industry, agricultural machinery, oil installations, offshore wind installations, etc., by applying an emulsion, or paint with effective anticorrosive and insulating capacity, especially in aggressive saline environments, due to the high iron adsorption capacity of the olive stone, which will confer extraordinary properties to these paints.

The object of the invention is to provide new families of paints that allow fuel and/or energy to be saved due to their insulating and anticorrosive characteristics, as well as lightening the weight of the structures where they are applied, with the consequent favorable constructive impact.

This new insulating and anticorrosive paint aims to be an additional, sustainable and ecological element to conventional paints whose application could be standardized and offer better conditions to all the sectors to which it can be incorporated.

BACKGROUND OF THE INVENTION

Currently there are anticorrosive paints that use organic and inorganic fillers, but they do not have the insulating and lightening properties of lignocellulose from the micronization of olive and/or palm pits.

The paints marketed in these areas can be classified according to the following criteria.

1. - According to its purpose.

- Background Layer

- Intermediate layers

- Finish coat

2. - According to its composition.

- Emulsion paints

- Lacquers and varnishes

- Bituminous

- With chemical reaction to its components

3. - According to its properties.

- Antioxidants and anticorrosive

- Fireproof and/or intumescent

- Waterproof

- Washable

- Submarines, antacids,... others

4. - Depending on the support.

- Woods

- Plastics

- Metallic

From a corrosion point of view, chromates were traditionally used, which were prohibited due to their harmful effects, being replaced by products composed of zinc phosphate, and lately other products with less contaminant load, although less effective, have appeared.

In short, in the current market there is no manufacturer that offers an industrial product with simultaneously anticorrosive and insulating properties and that also contains an ecological organic load such as lignocellulosic microparticles from the micronization of olive and/or palm pits. .

EXPLANATION OF THE INVENTION

The new procedure and consequently the product obtained that the invention proposes from olive pits and/or palm pits, is a new range of paints that incorporate lignocellulosic microparticles in the different layers that are applied as protection, since they have a biosorption of metal ions that will help delay and/or eliminate oxidative processes, so that each added layer has a different granulometry depending on the micron of the layer to be applied so that the finish is perfect.

In this sense, the lignocellulosic microparticles from the olive stone and/or the palm stone are different from the lignocellulosic characteristics of any wood, they have physical-chemical characteristics that allow their micronization, while the cellulose and lignin present in any vegetable it has totally different characteristics and a less favorable rheology, in an applicability context, than that of micronized bone.

The characteristics of insolubility that these lignocellulosic particles possess, even in aggressive environments such as seawater, give them extraordinary characteristics for their incorporation as paint fillers, which offer chemical protection of the coating and cause a state of passivation of the metal surface by its electrochemical protection, if you add its insulating protection, we can have a unique product for its incorporation into the different formulations of existing paints today.

These lignocellulosic particles have a double protection mechanism that could be a first advantage since their ability to retain potential aggressive ions from outside is added to their anticorrosion inhibiting capacity, which could improve long-term anticorrosion protection.

Most of the ships that make up the world's merchant fleet are made of steel and operate immersed in a corrosive medium such as sea water. The combination of these aspects means that the paint plays an important role as a treatment against corrosion, fundamentally that which originates in contact with water. In addition, the paint offers other purposes (anti-abrasive, anti-slip, antifouling, polishing, aesthetic...etc.)

Sea water is a concentrated electrolyte solution with many dissolved salts, the most abundant on our planet. The main factors that affect the corrosive activity of the marine environment are salinity, temperature, contamination, sediments, atmospheric exposure and the large number of welds present in the construction of the element. The objective is to reduce the action of these factors in the process. corrosive.

Consequently, an effective paint for application in these environments consists of the following basic components: the pigment (which provides color), the vehicle (solvent plus resin) and different additives and fillers.

The various types of resins, (polymeric composition), give rise to different types of paints, with specific suitability for specific applications.

From a functional point of view, thin and hard film paints are the most common and widespread.

The present invention seeks to provide a paint that offers better protection on iron and steel against corrosion and all this without using chemical compounds. considered dangerous for health, given that the appearance of strong environmental demands and the new awareness and ECO regulations, would be widely covered with the addition of this load of organic and abundant paints in the world and Spanish olive oil sector in particular, as well as in the palm sector, which due to its characteristics has little commercial outlet.

The method of the invention comprises the addition of lignocellulosic microparticles dispersed in a film-forming binder, where the lignocellulosic microparticles come from the micronization of olive pits and/or palm pits.

The particles of the water-insoluble lignocellulosic compound used to prepare fillers of this type should preferably have a diameter between 500 and 1 microns.

Micronized bone can be used in combination with other anticorrosive pigments. It has been found that particularly good corrosion protection can be achieved by paints which further contain a corrosion inhibitor which acts either on its own or in combination with another chemical species to modify the metal oxide film on the metal to be coated. protect by making it more effective.

Thus, the invention includes an anticorrosive coating composition comprising a lignocellulosic component dispersed in a film-forming binder, where the lignocellulosic particles from micronized olive and/or palm pits and optionally the addition of a passivator of the inorganic and/or organic corrosion capable of modifying the metal oxide film on the metal to be protected to make it more effective, in addition to having an additional insulating effect due to the lignocellulosic composition of the coating.

The volume concentration of pigments and fillers in the paint is preferably 20-50% depending on the film-forming polymer used.

The coating compositions of the invention are more generally used to prevent corrosion of iron and steel structures but can also be used in anticorrosive paints for metal surfaces other than iron, such as galvanized steel or aluminum, and can be used in prestressed concrete. good for coating tensioning bars to prevent corrosion or as an exterior coating for concrete to prevent the appearance of corrosive stains, especially in saline environments. The method of application of this anticorrosive and insulating coating is normally applied by roller, brush and spray with and without air.

Finally, it is worth highlighting the fact that, optionally, and to extend the performance of the paint, a compound based on titanium dioxide nanoparticles could also be added as a filler, which would give it an additional benefit, as is the degradation of odors and organic contaminants.

EXAMPLE OF PRACTICAL EMBODIMENT OF THE INVENTION.

As mentioned in the previous section, the process of the invention consists of the addition of lignocellulosic microparticles dispersed in a film-forming binder, where the lignocellulosic microparticles come from the micronization of the olive stone and/or bone of palm.

The composition of these micronized bones in general terms is:

Main olive stone components:

Lignin (%) 41.00

Cellulose (%) 24.80

Hemicellulose (%) 34.20

Main components of the palm bone

Lignin (%) 49.58

Cellulose (%) 30.28

Hemicellulose (%) 12.72

In the chosen example, olive pits were used as lignocellulosic microparticles, which were subjected to a micronization process until reaching an average size of 200 microns.

This product obtained was added as a filler in the conventional paint manufacturing process, during the phase of adding additives and fillers, so that by way of example, a table with one of the many composition possibilities for a paint obtained by the method of the invention:

From these proportions, a paint with a high anti-corrosive and thermal insulation power was obtained, ideal for its application in metal structures subjected to adverse weather conditions, such as shipping containers, bridges, etc.

In any case, and as has been said before, the granulometry chosen for the lignocellulosic microparticles will be different depending on the specific application in which the paint is to be applied, and four large groups can be defined:

1) A coating obtained by a surface conversion treatment, often used to improve metal/paint system adhesion. It has a thickness of a few microns, provides barrier protection and sometimes also has corrosion-inhibiting properties.

2) Primer paint, generally of variable thickness depending on the type of product, whose main functions are to ensure good adherence to the substrate to be protected, and delay its corrosion through anticorrosive pigments.

3) Intermediate paint (thicker layer), whose function is to improve the barrier property of the system.

4) Finish paint, whose function is to provide final characteristics to the paint system, such as color, brightness, etc.

Claims (4)

1§.- Procedure for obtaining paints with anti-corrosive and thermal insulation properties, which, starting from the conventional process for obtaining a paint, in which the corresponding pigments, vehicle (solvent and resin), as well as additives and fillers, is characterized by the fact that it consists of the addition of dispersed lignocellulosic microparticles from an olive pit and/or palm pit micronization process in a range between 500 to 1 micron, in the phase of adding the additives and loads. 2§.- Paint, which, based on the conventional structuring of a paint, in which pigments, a vehicle (solvent and resin) participate, as well as additives and fillers, is characterized by the fact that as a filler it includes lignocellulosic microparticles with anti-corrosive and anti-corrosion functions. thermal insulation, from olive and/or palm pits, with a particle size between 500 and 1 micron. 3§.- Paint, according to claim 2§, characterized in that it has a concentration in volume of pigments and fillers of 20-50%. 4§.- Paint, according to claim 2§, characterized in that as an additional filler it includes a compound based on titanium dioxide nanoparticles. 1