Self-cleaning, anti-smog, anti-mould photocatalytic powdered water based paint

Abstract

A photocatalytic powdered water based paint is described comprising photocatalytic binding cement, inert micronized limestone, low viscosity cellulose, fluidifying agent, anti-foaming agent, vinyl polymer and pigments. The water based paint is characterized by the fact of comprising at least one and preferably all the following further additives: metakaolin, titanium dioxide, calcium formate and kieselguhr.

Claims

1. Photocatalytic powdered paint for use diluted in water, comprising Portland cement admixed with nanoparticle photocatalytic Titanium Dioxide, the size of said Titanium Dioxide nanoparticles being lower than 5 nanometers; inert limestone with a maximum grain-size distribution lower than 100 microns; very low viscosity cellulose with viscosity lower than 1,000 mPas; fluidizer; antifoam; vinyl polymer and pigments, further comprising at least one and preferably all the following further additives: metakaolin, calcium formate and kieselguhr, wherein said fluidizer is a polycarboxylic acid fluidizer, wherein said vinyl polymer is a hydrophobized vinyl polymer and wherein the ingredients are contained in a formulation in ranges of percentages by weight shown in the following table TABLE-US-00015 RAW MATERIALS OF THE FORMULATION From % To % White Portland cement admixed with nanoparticle 40 50 photocatalytic Titanium Dioxide Inert limestone with a maximum grain-size 50 55 distribution lower than 100 microns Metakaolin 1.5 10 Low photocatalytic activity Titanium Dioxide 1.5 10 Very low viscosity cellulose 0.05 1.5 Calcium formate 0.5 5 Tartaric acid 0.05 1.5 Polycarboxylic acid fluidizer 0.1 1.2 Hydrophobized vinyl polymer 3 10 Antifoam 0.1 2.8 Low viscosity cellulose 0.1 1.2 Kieselguhr 0.5 3.5 Pigments q.s. q.s. wherein said pigments are coated with a cellulose-based film that, when coming into contact with water, dissolves to release the pigment, said film dissolving in a time lower than 2 seconds.

2. Paint according to claim 1, wherein said pigments are formed into granules whose dimensions have a grain-size range from 200 to 500 microns.

3. Paint according to claim 1, said film dissolving in a time lower than 1 second.

4. Paint according to claim 3, wherein said pigments are formed into granules whose dimensions have a grain-size range from 200 to 500 microns.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) Test 1Improvement in the Hiding Power of the Product.

(2) Test Performed by Application on a Contrast Card.

(3) 1. Weighing in two suitable containers the following components:

(4) TABLE-US-00004 COMPOSITION A COMPOSITION B Product Weight Product Weight Cement TX 1000 gr. Cement TX 1000 gr. Micronizzato 1000 gr. MIXER 100 1000 gr. C138M Culminal mhpc 10 gr. Culminal mhpc 10 gr. 500 pf 500 pf Melflux 2651F 6 gr. Melflux 2651F 6 gr. Titanium R-XL 100 gr.

(5) 2. Dry-mixing the components, naming them as follows: COMPOSITION A, COMPOSITION B.

(6) Afterwards it will be possible to make the mix by means of laboratory mixing equipment (Hobart):

(7) 3. Placing 350 gr. of water in the Hobart and under agitation adding 1000 gr. of the sample called COMPOSITION A, after 15 verifying that there is no material adherent to the walls of the mixer, should this be the case removing it by a paddle and continuing the mixing at a high number of revolutions for further 120, settling for 60 and adding further 250 gr. of water with a low number of revolutions for 45.

(8) 4. Repeating step 3. with the sample called COMPOSITION B.

(9) 5. Placing a suitable amount of the mixed materials, on the contrast card making sure that they are adjacent one another and not overlapped one another.

(10) 6. By means of the 150 film applicator, spreading the material up to the end of the card.

(11) 7. After drying verifying that the material has covered the white to black contrast.

(12) TABLE-US-00005 TABLE 1 RAW MATERIALS COMPOSITION A COMPOSITION B Cement TX 49.6% 47.25% Micronized MIXER 100 47.25% Micronized C138 M 49.6% Titanium R-XL 4.7% Culminal mhpc 500 pf 0.5% 0.5% Melflux 2651F 0.3% 0.3%

(13) Test Results:

(14) COMPOSITION A: contrast covered by 25%

(15) COMPOSITION B: contrast covered by 75%

(16) Final Notes:

(17) Table 1 schematically shows the compositions and their percentages by means of which the hiding power test has been performed. Composition B is definitely better because of the high point of white given by adding titanium dioxide, and because of the hiding power due to the micronized mixer 100 since it is finer than micronized C 138 M.

(18) Test 2Improvement in the Product Fluidity.

(19) Test Performed by Means of the Ford Cup no. 4

(20) 1. Weighing in a suitable container the following components:

(21) TABLE-US-00006 Cement TX 1000 gr. MIXER 100 1000 gr. Culminal mhpc 500 pf 10 gr.

(22) 2. Dry-mixing the components and dividing them into two further samples each one of 1000 gr., naming them as follows: Cp. 1a, Cp. 2b.

(23) 3. Adding to the sample called Cp. 1a 4.0 gr. of MELMENT F 10, and dry-mixing it. Adding to the sample called Cp. 2b 3.0 gr. of MELFUX 2651F, and dry-mixing it.

(24) Afterwards it will be possible to make the mix for performing the viscosity test by means of the Ford cup:

(25) 4. Placing 350 gr. of water in the Hobart (laboratory mixer) and under agitation adding 1000 gr. of the sample called Cp. 1a, after 15 verifying that there is no material adherent to the walls of the mixer, should this be the case removing it by a paddle and continuing the mixing at a high number of revolutions for further 120, settling for 60 and adding further 250 gr. of water at a low number of revolutions for 45. With the obtained mix, reading the viscosity by Ford cup no. 4.

(26) 5. Repeating step 4. with the sample called Cp. 2b.

(27) 6. Writing the results and verifying which is the product with the highest fluidity.

(28) TABLE-US-00007 TABLE 2 RAW MATERIALS Cp. 1a Cp. 2b Cement TX 49.65% 49.65% Micronized MIXER 100 49.65% 49.65% Culminal mhpc 500 pf 0.5% 0.5% Melment F 10 0.2% Melflux 2651F 0.2%

(29) Test Results:

(30) Viscosity after test by Ford cup Cp. 1a: 80

(31) Viscosity after test by Ford cup Cp. 2b: 40

(32) Final Notes:

(33) Table 2 schematically shows the compositions and their percentages by means of which the viscosity test by Ford cup no. 4 has been performed; it can be clearly seen by the results that, although having a low dosage, the product containing MELFLUX 2651F (Cp. 2b) makes the system more fluid, therefore increasing the processability of the product and improving the final aesthetical appearance.

(34) Test 3Improvement of the Setting Time and of the Mechanical Strengths of the Product.

(35) Test Performed by Means of Vicat Needle.

(36) 1. Weighing in two suitable containers the following components:

(37) TABLE-US-00008 COMPOSITION 1A COMPOSITION 1F Cement TX 1000 gr. Cement TX 1000 gr. MIXER 100 1000 gr. MIXER 100 1000 gr. Culminal mhpc 500 pf 10 gr. Culminal mhpc 500 pf 10 gr. Melflux 2651F 3 gr. Melflux 2651F 3 gr. Calcium formate 40 gr.

(38) 2. Dry-mixing the components naming the obtained products as COMPOSITION 1A and COMPOSITION 1F.

(39) Afterwards it will be possible to make the mix in order to take the setting time by means of Vicat needle:

(40) 3. Noting down the time when the test begins, placing 350 gr. of water in the Hobart (laboratory mixer) and under agitation adding 1000 gr. of the sample called COMPOSITION 1A, after 15 verifying that there is no material adherent to the walls of the mixer, should this be the case removing it by a paddle and continuing the mixing at a high number of revolutions for further 120, settling for 60 and adding further 250 gr. of water at a low number of revolutions for 45.

(41) 4. Placing the obtained mix in the frustum of cone of the Vicat needle, that has been previously calibrated.

(42) 5. Bringing the plunger in contact with the mix and releasing the plunger such that it can penetrate into the mix, reading the penetration, noting down the time and penetration, cleaning the plunger.

(43) 6. Repeating step 5. at regular time periods decreasing the rest time between one penetration and the following one after setting has started. The setting is said to have started when the penetration of the plunger is not more at full scale, but it stops at least by 2 mm., the test is said to have ended when the plunger is not more able to penetrate into the mix by at least 3 mm.

(44) Repeating steps 3., 4., 5., 6., with the sample called as COMPOSITION 1F.

(45) In this case, due to the length of the test, an automatic Vicat needle has been used, by setting the penetration time, then data have been stored by the internal software.

(46) TABLE-US-00009 TABLE 3 RAW MATERIALS COMPOSITION 1A COMPOSITION 1F Cement TX 49.68% 48.73% Micronized MIXER 100 49.68% 48.73% Culminal mhpc 500 pf 0.49% 0.49% Melflux 2651F 0.15% 0.15% Calcium formate 1.90%

(47) Test Results:

(48) TABLE-US-00010 TABLE 4 Start of setting End of setting COMPOSITION 1A 6 h 30 12 h 20 COMPOSITION 1F 5 h 30 7 h 20

(49) Final Notes:

(50) Table 3 schematically shows the compositions and their percentages by means of which the setting time test has been performed, and table 4 shows the results; from these results it can be clearly noted that the calcium formate plays an important reaction role with the cement paste causing the paste to set more quickly, such situation allows the final paint to be exposed earlier to the atmospheric agents without being subjected to considerable changes as it occurs with long setting time such as the case of the composition 1A.

(51) Test 4Improvement of the Resistance to Water.

(52) Water Drop Test on the Contrast Card

(53) 1. Weighing in two suitable containers the following components:

(54) TABLE-US-00011 COMPOSITION A COMPOSITION B Cement TX 1000 gr. Cement TX 1000 gr. MIXER 100 1000 gr. MIXER 100 1000 gr. Culminal mhpc 500 pf 10 gr. Culminal mhpc 500 pf 10 gr. Melflux 2651F 6 gr. Melflux 2651F 6 gr. Pentaresin P3 100 gr. Vinnapas 8034H 100 gr.

(55) 2. Dry-mixing the components, naming them as follows: COMPOSITION A, COMPOSITION B.

(56) Afterwards it will be possible to make the mix by means of laboratory mixing equipment (Hobart):

(57) 3. Placing 350 gr. of water in the Hobart and under agitation adding 1000 gr. of the sample called COMPOSITION A, after 15 verifying that there is no material adherent to the walls of the mixer, should this be the case removing it by a paddle and continuing the mixing at a high number of revolutions for further 120, settling for 60 and adding further 250 gr. of water at a low number of revolutions for 45.

(58) 4. Repeating step 4. with the sample called COMPOSITION B.

(59) 5. Placing a suitable amount of the mixed materials, on the contrast card that has been previously named with the type of composition under testing.

(60) 6. By means of the 150 film applicator, spreading the material up to the end of the card.

(61) 7. After drying, pouring some water drops on the applied film, after its evaporation investigating the film condition.

(62) TABLE-US-00012 TABLE 5 RAW MATERIALS COMPOSITION A COMPOSITION B Cement TX 47.25% 47.25% Micronized MIXER 100 47.25% 47.25% Culminal mhpc 500 pf 0.47% 0.47% Melflux 2651F 0.3% 0.3% Pentaresin P3 4.73% Vinnapas 8034H 4.73%

(63) Test Results:

(64) COMPOSITION A: Partial softening of the film after evaporation of the water drop.

(65) COMPOSITION B: In some case a slight mark after evaporation of the water drop.

(66) Final Notes:

(67) Table 5 schematically shows the compositions and their percentages by means of which the water drop test has been performed. The composition B yields a better performance the film does not undergo any softening and the mark generated only in cases with a larger drop.

(68) By combining together the results obtained from tests 1-4, shown above, therefore it has been decided to add to the standard mixture the new additives tested in said tests and specifically the titanium dioxide and the fine micronized limestone in order to improve the product hiding power (Test 1), the polycarboxylic acid-based fluidifying agent in order to improve the product viscosity (Test 2), the calcium formate in order to improve the setting time and the mechanical strengths of the product (Test 3) and the hydrophobic vinyl polymer in order to improve the resistance to water of the product (Test 4).

(69) Thus we arrived to the final formulation of the excellent water based paint of the present invention, summarized in the following table, wherein the percentages by weight are the optimal and preferred ones but they are not limitative.

(70) TABLE-US-00013 RAW MATERIALS OF THE INVENTIVE FORMULATION From % To % Cement TX - photocatalytic binder 40 50 Micronized Mixer 100 - limestone more fine and 45 55 with a higher hiding power - Test 1 Power Pozz White - metakaolin 1.5 10 Titanium dioxide - hiding white - Test 1 1.5 10 Culminal mhpc 500 pf - very low viscosity cellulose 0.05 1.5 Calcium formate - set accelerator - Test 3 0.5 5 Tartaric acid - set retarder 0.05 1.5 Melflux 2651F - polycarboxylic acid 0.1 1.2 fluidifying agent - Test 2 Vinnapas 8034 - hydrophobic vinyl polymer - Test 4 3 10 Deofoam AP199 - anti-foaming agent 0.1 2.8 Tecnocell 500 - low viscosity cellulose fibres 0.1 1.2 Celite - kieselguhr 0.5 3.5 Immediately dispersible pigments Pantocrom q.s. q.s.

(71) Thus we have come to the final formulation of the excellent water based paint of the present invention. As regards the production of the water based paint from the production perspective, the mixing plant of the applicant located in Marcellina, province of Rome, has been used; after having found the ideal composition in laboratory after the tests previously described, it has been necessary to store the raw materials to be used into the storage silos that have been accurately emptied and cleaned, then the recipe has been stored in the production managing software, (recipe code no. 75) such that all the weighings of the recipe occur in a completely automated manner reducing to zero the possibilities of doing weighing errors, the production scales MEMOMATIC model type 7053 called as scale 1, scale 2, scale 3, as the mixer model M-TEC type MR 150V serial number 9161092002 are subjected to a annual calibration and inspection. The production process can be summarized as follows: Automatically weighing the cement by means of a charging feeder directly on the scale 1; Unloading the scale 1 into the mixer; Automatically weighing the additives by means of charging feeders directly on scale 3; Unloading the scale 3 into the mixer; Automatically weighing the micronized by means of a charging feeder directly on scale 2; Unloading the scale 2 into the mixer; Starting to mix firstly only by the help of the mixing blade, then even by means of three turbulators provided within the mixer (the blade serves for roughly mix the raw materials inserted therein, while the turbulators allow even the finest parts of the components to be mixed more closely) Unloading the mix into the storage silos.

(72) The mixing time of the blade and of the turbulators have been set on the basis of the acquired experience in the following mode:

(73) Blade mixing time 180

(74) Turbulator mixing time 180.

(75) In order to verify the complete homogeneity of the components several material samples have been taken in various phases during the paint canning, and after having mixed the material using always the same method used in the laboratory tests, viscosity has been investigated, we have obtained the same value in each case, therefore the material is completely homogeneous in the whole production lot thereof.

(76) Table 6 shows the values detected during the production control.

(77) TABLE-US-00014 TABLE 6 SAMPLE VISCOSITY START 55 SAMPLE 1/3 55 SAMPLE 2/3 55 END 55

(78) Therefore it is possible to conclude that a very high quality photocatalytic water based paint has been obtained, helping in maintaining the air clean and the building faces more clean for a long time, decreasing their reconstruction costs, it is easy to be applied, it has considerably improved characteristics of hiding power, viscosity, water resistance, setting time and mechanical strength. It has to be pointed out also that the indication of the trade name of the several used additives is not to be considered as a limitation but as a mere example and such additives can be replaced by other products having like characteristics and meeting the same requirements set forth in the previous description and in the annexed claims.