PL240956B1 - Waterborne varnish with the addition of graphene oxide with anti-corrosive properties - Google Patents

Abstract

The subject of the application is a water-soluble varnish containing 2-butoxyethanol and 1-isopropyl-2,2-dimethyldiisobutyrate additionally containing graphene oxide in a concentration of 0.01% by weight. up to 10% by weight

Description

Description of the invention

The subject of the invention is a water-based varnish with the addition of graphene oxide with anti-corrosive properties and the method of its preparation.

The invention belongs to the field of materials engineering.

Coatings made of paints and varnishes are an effective and very popular anticorrosive agent, protecting the surface of various materials, such as metals, wood, concrete and composites. In addition to the undoubted (significant) anti-corrosion properties, these coatings help to give the manufactured products the appropriate color, shade and surface structure, which increases their attractiveness on the market. The advantages of using varnish coatings cannot be overestimated in many branches of the economy. Serious issues not only in the economic sense, but also in human health and environmental safety, is the possibility of eliminating the currently dangerous anti-corrosion technologies such as: chromate conversion coatings [Bohannon J. 'Smart coatings' research shows the virtues of superficiality. Science 2005; 309: 376-7] or cadmium coatings [Indumathi S. N., Vansudevan T., Sundarrajan S., Subba Rao B. V., Murthy C.V.S., Yadav D.R., Cadminum- and chromate-free coating schemes for corrosion protection of 15CDV6 steel. Metal Finishing, Vol. 109 (3) (2011) pp. 15-21].

High hopes for further development of the application of coatings obtained from paints and varnishes are associated with the use of nanotechology and nanomaterials. Such materials include, inter alia, various allotropic forms of carbon such as nanodiamond, nanotubes [Mochalin V. N., Gogotsi Y., Nanodiamond-polymer composites, Diamond and Related Materials, Vol. 58, (2015), pp. 161-171], fullerenes or graphene in the form of flakes and graphene derivatives such as graphene oxide [S. Liu, V. S. Chevali, Z. Xu, D. Hui, H. Wang, A review of extending performance of epoxy resins using carbon nanomaterials, Composites Part B: Engineering, Vol. 136, (2018), pp. 197-214].

From the Chinese application no. CN10743424 there is known a solution which describes corrosion inhibitors containing an active cinnamon-aldehyde group. The compound 5-p-methylphenyl-1-amino- (1,3,4-triazole) -2-mercapto] -acetylhydrazone at the active site of the functional group contains oxygen in the layer of graphene molecules. The compound is applied to prevent corrosion initiation of the carbon steel and rebar.

The graphene molecular layer catalyzes the cathodic oxygen reduction reaction during the electrochemical process between a corrosion inhibitor and carbon steel. The corrosion inhibitor is easy to mass-produce and efficient.

In the description of the American invention US2014 / 0030636A the protected solution is a composite anticorrosive graphene coating deposited electrophoretic or electroplating on a metal surface. It has been found that the composite coating significantly increases the resistance of the metal surface to electrochemical degradation. The graphene coating significantly reduces the cathode current, which is an indicator of the corrosion rate at the interface between the cathode material and the anode material.

The invention reported under No. CN107245297 relates to a marine anti-corrosive protective material, in particular a marine anti-corrosive film, made by adding graphene oxide to a metal surface using an LBL technique with a pressure sensitive adhesive layer, and the method of the invention. Sea anti-corrosion foil. The method includes the following steps: immersing an aluminum alloy sample in a cerium nitrate solution, drying at high temperature after soaking, applying layers of polyethyleneimine (PEI) and polyacrylic acid (PAA), carrying out the deposition of graphene oxide. The effectiveness of inhibiting the initiation and development of corrosion of the multilayer self-forming film with graphene oxide on the surface of an aluminum alloy in a 3.5% NaCl solution exceeds 99%. Corrosion inhibition efficiency of multi-layer self-assembling film> 96%.

The object of the present invention is to provide a water-borne liquid lacquer material with anti-corrosive properties for the protection of metal substrates.

The essence of the invention is a water-borne lacquer containing 2-butoxyethanol and 1-isopropyl-2,2-dimethyldiisobutyrate and additionally containing graphene oxide at a concentration of 0.01% by weight. up to 10 wt.% The graphene oxide present in the varnish is in the form of a dry powder; or suspensions of graphene oxide in water, a polar solvent, a non-polar solvent, a mixture of water and a polar or non-polar solvent, a mixture of polar and non-polar solvents; or graphene oxide pastes in water, a polar solvent, a non-polar solvent, a mixture

Of water and a polar or non-polar solvent, a mixture of polar and non-polar solvents.

A water-soluble varnish is prepared by adding graphene oxide to a varnish containing 2-butoxyethanol and 1-isopropyl-2,2-dimethyldiisobutyrate in a proportion of 0.01% by weight. up to 10 wt.% and then mixing it with this varnish, preferably for not less than five seconds, in high shear mixers, preferably a non-contact planetary mixer, at a rotation frequency in the range of 50-5000 rpm.

The effects of the invention are presented in the figures, where Fig. 1 shows the surface of the sample covered with a water-borne varnish without the addition of graphene oxide before (a) and after 96 hours of the corrosive environment (b, c and d), Fig. 2 shows the surface of the sample covered with a water-borne varnish with the addition of graphene oxide before (a) and after 96 h (b, c and d) of the corrosive environment.

Compared to the solutions known from the state of the art, the varnish according to the present invention is characterized by better anti-corrosion properties in an environment of neutral salt mist.

Corrosion in the case of samples coated with water-based varnish without the addition of graphene oxide occurred approximately on 20% of the surface, while in the case of samples with the addition of graphene oxide, it was up to 0.5% of the tested sample.

The application properties of the liquid varnish material with the addition of graphene oxide, i.e. covering and flow properties, did not deteriorate.

The influence of the corrosive environment on the surface of the sample covered with a layer of water-soluble varnish without the addition of graphene oxide resulted in the formation of numerous corrosion pits under the varnish layer (Fig. 1b). The lacquer was broken (Fig. 1 b and c).

The development of surface corrosion (Fig. 2) was not observed on the sample surface covered with water-based varnish with the addition of graphene oxide.

The water-based varnish with the addition of graphene oxide showed better anti-corrosion properties in the environment of neutral salt mist than before the introduction of graphene oxide into it.

The invention has been implemented on an embodiment where:

P r z k ł a d I

The invention has been realized in a preferred embodiment, wherein the water-borne acrylic resin lacquer containing 2-butoxyethanol and 1-isopropyl-2,2-dimethyldiisobutyrate additionally comprises graphene oxide at a concentration of 0.1% by weight. which is 1 g / kg of varnish in the form of a powder. Graphene oxide is introduced in a separate step as an independent additive to the paint formulation process.

Water-borne varnish with the addition of anti-corrosive graphene oxide is obtained by introducing graphene oxide in the form of a powder into the water-borne varnish and then mixing the water-borne varnish with graphene oxide in a non-contact mixer. Mixing of the varnish with graphene oxide was carried out in a non-contact planetary mixer, 3500 rpm, at room temperature, with air humidity of 40%, mixing time 5 min. The samples were mixed in a non-contact planetary mixer.

The concentration of graphene oxide in the water-based varnish is 0.1% by weight. The corrosion resistance test was carried out in an inert atmosphere of salt mist according to PN EN ISO 9227: 2012. The total time of corrosion exposure was 240 hours. Corrosion of the sample covered with the so prepared varnish occurred on 2% of the surface. The assessment of the degree of corrosion of the samples was carried out on the basis of standardized assessment methods after corrosion tests, in particular the assessment of the degree of rusting according to PN-EN ISO 4628-3: 2016 and blistering according to PN-EN ISO 46282: 2016. The evaluation of the corrosion test results consisted of a comparative evaluation with the image patterns of corrosion damage attached to the above-mentioned standards. After the tests, a random assessment of the surface of the samples was also carried out using a light microscope in order to illustrate the nature of corrosion changes and the distribution of corrosion products formed during the tests.

P r z x l a d II

The water-based varnish with the addition of anticorrosive graphene oxide was obtained by the method as in Example 1, where the concentration of graphene oxide in the water-borne varnish is 1.0% by weight. The corrosion resistance test was carried out in an inert atmosphere of salt mist according to PN-EN ISO 9227: 2012. The total time of corrosion exposure is

The time was 240 hours. Corrosion of the sample covered with the so prepared varnish occurred on 0.5% of the surface. The assessment of the degree of corrosion of the samples was carried out on the basis of standardized assessment methods after corrosion tests, in particular the assessment of the degree of rusting according to PN-EN ISO 4628-3: 2016 and blistering according to PN-EN ISO 4628-2: 2016. The evaluation of the corrosion test results consisted of a comparative evaluation with the image patterns of corrosion damage attached to the above-mentioned standards. After the tests, a random assessment of the surface of the samples was also carried out using a light microscope in order to illustrate the nature of corrosion changes and the distribution of corrosion products formed during the tests.

Claims (2)

1. A water-soluble varnish containing 2-butoxyethanol and 1-isopropyl-2,2-dimethyldiisobutyrate, characterized in that it additionally contains graphene oxide at a concentration of 0.01% by weight. up to 10 wt.% and the graphene oxide present in the varnish is in the form of a dry powder; or suspensions of graphene oxide in water, a polar solvent, a non-polar solvent, a mixture of water and a polar or non-polar solvent, a mixture of polar and non-polar solvents; or graphene oxide pastes in water, a polar solvent, a non-polar solvent, a mixture of water and a polar or non-polar solvent, a mixture of polar and non-polar solvents. 2. A water-soluble varnish, characterized in that it is obtained by adding graphene oxide to a varnish containing 2-butoxyethanol and 1-isopropyl-2,2-dimethyldiisobutyrate in a proportion of 0.01% by weight. % by weight and then mixed with this varnish, preferably with mixing for not less than five seconds, in high shear mixers, preferably a non-contact planetary mixer, with a rotation frequency in the range of 50-5000 rpm.