WO2020076177A1 - Doped titania or zinc oxide additive for ceramic glazes, ceramic glaze, activation method and process for producing the additive - Google Patents
Doped titania or zinc oxide additive for ceramic glazes, ceramic glaze, activation method and process for producing the additive Download PDFInfo
- Publication number
- WO2020076177A1 WO2020076177A1 PCT/RO2019/000025 RO2019000025W WO2020076177A1 WO 2020076177 A1 WO2020076177 A1 WO 2020076177A1 RO 2019000025 W RO2019000025 W RO 2019000025W WO 2020076177 A1 WO2020076177 A1 WO 2020076177A1
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- WO
- WIPO (PCT)
- Prior art keywords
- ceramic
- additive
- photocatalytic
- glaze
- composition
- Prior art date
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- 239000000919 ceramic Substances 0.000 title claims abstract description 178
- 238000000034 method Methods 0.000 title claims abstract description 70
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 title claims abstract description 64
- 239000000654 additive Substances 0.000 title claims abstract description 33
- 230000000996 additive effect Effects 0.000 title claims abstract description 30
- 230000008569 process Effects 0.000 title claims abstract description 30
- 230000004913 activation Effects 0.000 title claims abstract description 20
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 title description 90
- 239000011787 zinc oxide Substances 0.000 title description 45
- 230000001699 photocatalysis Effects 0.000 claims abstract description 97
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 74
- 239000004065 semiconductor Substances 0.000 claims abstract description 71
- 239000000203 mixture Substances 0.000 claims abstract description 60
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 52
- 230000003115 biocidal effect Effects 0.000 claims abstract description 33
- 229910052802 copper Inorganic materials 0.000 claims abstract description 27
- 229910052709 silver Inorganic materials 0.000 claims abstract description 26
- 229910052737 gold Inorganic materials 0.000 claims abstract description 24
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 24
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 23
- 229910052742 iron Inorganic materials 0.000 claims abstract description 23
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 23
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 claims abstract description 15
- 239000002245 particle Substances 0.000 claims abstract description 14
- 150000002500 ions Chemical class 0.000 claims abstract description 12
- 239000010459 dolomite Substances 0.000 claims abstract description 11
- 229910000514 dolomite Inorganic materials 0.000 claims abstract description 11
- 239000010433 feldspar Substances 0.000 claims abstract description 10
- 230000003213 activating effect Effects 0.000 claims abstract description 9
- 239000003513 alkali Substances 0.000 claims abstract description 8
- 229910021538 borax Inorganic materials 0.000 claims abstract description 8
- 239000004576 sand Substances 0.000 claims abstract description 8
- 239000004328 sodium tetraborate Substances 0.000 claims abstract description 8
- 235000010339 sodium tetraborate Nutrition 0.000 claims abstract description 8
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 30
- 230000003595 spectral effect Effects 0.000 claims description 22
- 239000000243 solution Substances 0.000 claims description 16
- 239000000049 pigment Substances 0.000 claims description 14
- 239000003795 chemical substances by application Substances 0.000 claims description 11
- 238000005469 granulation Methods 0.000 claims description 10
- 230000003179 granulation Effects 0.000 claims description 10
- 150000003624 transition metals Chemical class 0.000 claims description 9
- 229910052723 transition metal Inorganic materials 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 6
- 239000002184 metal Substances 0.000 claims description 6
- 239000004014 plasticizer Substances 0.000 claims description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 6
- 238000003801 milling Methods 0.000 claims description 5
- 239000002019 doping agent Substances 0.000 claims description 4
- 239000000725 suspension Substances 0.000 claims description 4
- 239000011248 coating agent Substances 0.000 claims description 3
- 238000000576 coating method Methods 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 3
- 150000003839 salts Chemical class 0.000 claims description 3
- 238000000498 ball milling Methods 0.000 claims description 2
- 239000003637 basic solution Substances 0.000 claims description 2
- 238000010583 slow cooling Methods 0.000 claims description 2
- 229910052573 porcelain Inorganic materials 0.000 claims 1
- 230000005855 radiation Effects 0.000 abstract description 19
- 230000009471 action Effects 0.000 abstract description 6
- 239000000645 desinfectant Substances 0.000 abstract description 6
- 230000001678 irradiating effect Effects 0.000 abstract description 5
- 239000010949 copper Substances 0.000 description 28
- 238000004659 sterilization and disinfection Methods 0.000 description 22
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 20
- 239000003504 photosensitizing agent Substances 0.000 description 19
- 230000005670 electromagnetic radiation Effects 0.000 description 18
- 239000003642 reactive oxygen metabolite Substances 0.000 description 16
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 12
- 230000000844 anti-bacterial effect Effects 0.000 description 10
- 229910021645 metal ion Inorganic materials 0.000 description 10
- 238000001311 chemical methods and process Methods 0.000 description 8
- 238000000227 grinding Methods 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- 239000013078 crystal Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 244000005700 microbiome Species 0.000 description 7
- 229910052760 oxygen Inorganic materials 0.000 description 7
- 239000001301 oxygen Substances 0.000 description 7
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 6
- 230000000843 anti-fungal effect Effects 0.000 description 6
- 229940121375 antifungal agent Drugs 0.000 description 6
- 241000894007 species Species 0.000 description 6
- 230000000845 anti-microbial effect Effects 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- BERDEBHAJNAUOM-UHFFFAOYSA-N copper(I) oxide Inorganic materials [Cu]O[Cu] BERDEBHAJNAUOM-UHFFFAOYSA-N 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000011941 photocatalyst Substances 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- 238000003860 storage Methods 0.000 description 5
- 238000012546 transfer Methods 0.000 description 5
- 238000001429 visible spectrum Methods 0.000 description 5
- 206010011409 Cross infection Diseases 0.000 description 4
- 230000001580 bacterial effect Effects 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 210000004027 cell Anatomy 0.000 description 4
- 238000002485 combustion reaction Methods 0.000 description 4
- 239000002131 composite material Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000000265 homogenisation Methods 0.000 description 4
- 239000003973 paint Substances 0.000 description 4
- 238000007146 photocatalysis Methods 0.000 description 4
- 239000004033 plastic Substances 0.000 description 4
- 229920003023 plastic Polymers 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 230000001960 triggered effect Effects 0.000 description 4
- VMQMZMRVKUZKQL-UHFFFAOYSA-N Cu+ Chemical compound [Cu+] VMQMZMRVKUZKQL-UHFFFAOYSA-N 0.000 description 3
- 241000588724 Escherichia coli Species 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 244000052616 bacterial pathogen Species 0.000 description 3
- 239000002585 base Substances 0.000 description 3
- 238000005034 decoration Methods 0.000 description 3
- 239000010408 film Substances 0.000 description 3
- 235000013305 food Nutrition 0.000 description 3
- 239000012528 membrane Substances 0.000 description 3
- 230000000813 microbial effect Effects 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 238000011158 quantitative evaluation Methods 0.000 description 3
- 238000006862 quantum yield reaction Methods 0.000 description 3
- 229910001428 transition metal ion Inorganic materials 0.000 description 3
- 241000894006 Bacteria Species 0.000 description 2
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 2
- 239000005751 Copper oxide Substances 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 2
- 239000006004 Quartz sand Substances 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 239000012472 biological sample Substances 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 239000004568 cement Substances 0.000 description 2
- 239000004567 concrete Substances 0.000 description 2
- 229910000431 copper oxide Inorganic materials 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 230000000593 degrading effect Effects 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 230000000977 initiatory effect Effects 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 239000006028 limestone Substances 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 239000002105 nanoparticle Substances 0.000 description 2
- 238000013032 photocatalytic reaction Methods 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000027756 respiratory electron transport chain Effects 0.000 description 2
- 150000004760 silicates Chemical class 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 238000003980 solgel method Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 239000004408 titanium dioxide Substances 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 239000007848 Bronsted acid Substances 0.000 description 1
- 240000001046 Lactobacillus acidophilus Species 0.000 description 1
- 235000013956 Lactobacillus acidophilus Nutrition 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 240000004808 Saccharomyces cerevisiae Species 0.000 description 1
- 235000014680 Saccharomyces cerevisiae Nutrition 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 241000191967 Staphylococcus aureus Species 0.000 description 1
- 230000001464 adherent effect Effects 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 239000003899 bactericide agent Substances 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000003139 biocide Substances 0.000 description 1
- 210000002421 cell wall Anatomy 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 239000011246 composite particle Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- KRFJLUBVMFXRPN-UHFFFAOYSA-N cuprous oxide Chemical compound [O-2].[Cu+].[Cu+] KRFJLUBVMFXRPN-UHFFFAOYSA-N 0.000 description 1
- 229940112669 cuprous oxide Drugs 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000007580 dry-mixing Methods 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 230000002538 fungal effect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 208000015181 infectious disease Diseases 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 230000003834 intracellular effect Effects 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- 235000013980 iron oxide Nutrition 0.000 description 1
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 1
- 238000009533 lab test Methods 0.000 description 1
- 229940039695 lactobacillus acidophilus Drugs 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000002906 microbiologic effect Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000000123 paper Substances 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 238000007539 photo-oxidation reaction Methods 0.000 description 1
- 230000001941 photobactericidal effect Effects 0.000 description 1
- 230000000886 photobiology Effects 0.000 description 1
- 238000006552 photochemical reaction Methods 0.000 description 1
- 238000002428 photodynamic therapy Methods 0.000 description 1
- 230000002165 photosensitisation Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000010944 silver (metal) Substances 0.000 description 1
- -1 silver ions Chemical class 0.000 description 1
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(I) nitrate Inorganic materials [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 238000006276 transfer reaction Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000002211 ultraviolet spectrum Methods 0.000 description 1
- 238000004017 vitrification Methods 0.000 description 1
- 238000004078 waterproofing Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
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- B01J35/39—
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
- A61L2/02—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor using physical phenomena
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- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
- B01J23/24—Chromium, molybdenum or tungsten
- B01J23/26—Chromium
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- B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
- B01J23/32—Manganese, technetium or rhenium
- B01J23/34—Manganese
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- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/48—Silver or gold
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- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/48—Silver or gold
- B01J23/50—Silver
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- B—PERFORMING OPERATIONS; TRANSPORTING
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- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
- B01J23/72—Copper
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- B—PERFORMING OPERATIONS; TRANSPORTING
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- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
- B01J23/74—Iron group metals
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- B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
- B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/80—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with zinc, cadmium or mercury
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- B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
- B01J37/0027—Powdering
- B01J37/0036—Grinding
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- B01J37/08—Heat treatment
- B01J37/082—Decomposition and pyrolysis
- B01J37/088—Decomposition of a metal salt
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G23/00—Compounds of titanium
- C01G23/04—Oxides; Hydroxides
- C01G23/047—Titanium dioxide
- C01G23/08—Drying; Calcining ; After treatment of titanium oxide
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- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
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- C01G9/02—Oxides; Hydroxides
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- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
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- C—CHEMISTRY; METALLURGY
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- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
- C04B41/50—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials
- C04B41/5022—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials with vitreous materials
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- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
- C04B41/81—Coating or impregnation
- C04B41/85—Coating or impregnation with inorganic materials
- C04B41/86—Glazes; Cold glazes
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- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/0009—Pigments for ceramics
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/04—Compounds of zinc
- C09C1/043—Zinc oxide
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/36—Compounds of titanium
- C09C1/3607—Titanium dioxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/50—Solid solutions
- C01P2002/52—Solid solutions containing elements as dopants
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/0081—Uses not provided for elsewhere in C04B2111/00 as catalysts or catalyst carriers
- C04B2111/00827—Photocatalysts
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- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/36—Compounds of titanium
- C09C1/3607—Titanium dioxide
- C09C1/3615—Physical treatment, e.g. grinding, treatment with ultrasonic vibrations
- C09C1/3638—Agglomeration, granulation, pelleting
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- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C3/00—Treatment in general of inorganic materials, other than fibrous fillers, to enhance their pigmenting or filling properties
- C09C3/04—Physical treatment, e.g. grinding, treatment with ultrasonic vibrations
- C09C3/045—Agglomeration, granulation, pelleting
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- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03C—DOMESTIC PLUMBING INSTALLATIONS FOR FRESH WATER OR WASTE WATER; SINKS
- E03C1/00—Domestic plumbing installations for fresh water or waste water; Sinks
- E03C1/12—Plumbing installations for waste water; Basins or fountains connected thereto; Sinks
- E03C1/18—Sinks, whether or not connected to the waste-pipe
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- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03D—WATER-CLOSETS OR URINALS WITH FLUSHING DEVICES; FLUSHING VALVES THEREFOR
- E03D11/00—Other component parts of water-closets, e.g. noise-reducing means in the flushing system, flushing pipes mounted in the bowl, seals for the bowl outlet, devices preventing overflow of the bowl contents; devices forming a water seal in the bowl after flushing, devices eliminating obstructions in the bowl outlet or preventing backflow of water and excrements from the waterpipe
- E03D11/02—Water-closet bowls ; Bowls with a double odour seal optionally with provisions for a good siphonic action; siphons as part of the bowl
Definitions
- the present invention refers to an additive for ceramic glazes, a composition of ceramic glaze, a method of activating the photocata lytic activity of ceramic glazes and to a process for making the additive.
- the patent US2006/0116279 discloses a method of preparing a composite based on semiconductor metal oxides such as titanium dioxide which is mixed with an inorganic material, such as silica or a Bronsted acid salt, preferably phosphate.
- the composite particles are produced by dry mixing under specific conditions, determined by selecting suitable parameters.
- the major disadvantage of this technique is that, in order to activate the photosensitizer, it is necessary to radiate with light from the UV-A domain, which is in small quantities in the light radiation.
- the use of semiconductor metal oxide nanoparticles has a number of technical disadvantages because they cannot be dissolved in the mass that will form the glaze raw material, the increased electronegativity of these particles leading to particle agglomerations difficult to disperse.
- the nanoparticles immediately form agglomerations which, upon cooling, crack the body of the glaze.
- An object of the present invention is to provide an additive for ceramic glazes comprising a photocatalytic agent based on semiconductor metal oxides of the Ti0 2 or ZnO type, doped in their crystalline structure with transitional metal ions selected from: Ag, Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof, between 0.7 and up to 4.5 parts by weight, given the total weight of the semiconductor metal oxide.
- composition of the additive for ceramic glazes there can be used metal oxides with a particle granulation of Ti0 2 or ZnO between 1 and 100 micrometers, for industrial use.
- the additive as described can be used at a granulation of 10 to 50 micrometers.
- Another object of the present invention is to provide a photocatalytic ceramic glaze composition
- a photocatalytic ceramic glaze composition comprising: 80-97 parts by weight, given the total weight of the composition, feldspar, sand, dolomite, alkali and / or alkaline-earth oxides, borax, plasticizers, color pigments; and between 3 to 20 parts by weight, given the total weight of the composition, of the additive according to the invention.
- the composition of the photocatalytic ceramic glaze can be used to cover sanitary ceramic objects, sanitary porcelainor faience objects and ceramic tiles, on at least one surface.
- the composition of biocidal photocatalytic ceramic glaze disclosed herein is a biocidal photocatalytic ceramic glaze composition which the surface of ceramic products, sanitary faience ware and ceramic tiles is covered with by glazing, and is made of feldspar, sand, dolomite, alkali and/ or alkaline-earth oxides, borax and whereat it is added in mass ratio, given the total mass of the composition, between 3 to 20 parts of a biocidal photocatalytic agent made of semiconductor metal oxide particles of the Ti0 2 or ZnO type, doped in their crystalline structure with transitional metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof.
- Transition metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn are added as dopants in the crystalline structure of the semiconductor metal oxides of the Ti0 2 or ZnO type in ratios ranging from 0.7 to 4.5 parts by weight, given the total weight of the semiconductor metal oxide.
- the doping modifies the energy of the forbidden band. In this way the semiconductor metal oxides can be excited by the light radiation from the visible spectrum and can trigger a series of phenomena with disinfectant biocidal photocatalytic properties.
- the biocidal photocatalytic ceramic glaze is applied by known technologies on the surface of ceramic products, sanitary faience ware or on the surface of ceramic tiles.
- a photocatalytic method of activating the doped semiconductor metallic oxide photosensitizer, dispersed in the composition of the biocidal photocatalytic ceramic glaze described above which consisted of exposing the glazed surfaces to a light source emitting at wavelengths of 450 ⁇ 550 nm.
- the light source can be a LED indoor lighting source, which also emits quanta from the visible spectrum with a wavelength ranging between 450 ⁇ 550 nm.
- the irradiation can be permanent or intermittent, depending on the needs, thus realising the photocatalytic activation of the semiconductor metal oxide doped and dispersed in the ceramic glaze composition.
- the light that irradiates the ceramic glaze generates, at the level of the semiconductor metallic oxide in the glaze, the initiation of the chemical process of photocatalysis.
- Semiconductor metal oxides act as a photosensitizer in photocatalytic reactions.
- the photocatalytic effect is determined by the energy of the forbidden band.
- the band energy is of 3.2 eV - 3.3 eV, and it corresponds to the near ultraviolet spectral domain, with wavelengths of 360 nm - 380 nm.
- the generation of photocatalytic chemical reactions is obtained when the semiconductor metal oxide of the Ti0 2 or ZnO type is excited by the light energy equal to or greater than the bandwidth of the forbidden band.
- the effect and mode of action in the photodynamic therapy of photosensitizers based on photochemical reactions are known.
- the disinfectant action of the semiconductor metallic oxide photosensitizers of the Ti0 2 or ZnO type is achieved by the appearance of this photocatalytic mechanism, triggered by the interaction of the photosensitizing agent, which contains the semiconductor metallic oxides of the Ti0 2 or ZnO type, with a light of a certain wavelength, as a result appearing the reactive oxygen species - oxygen singlet ROS, reactive species with a decisive role in the destruction of microorganisms, and which give these reactive species bactericidal and antifungal role.
- ROS reactive oxygen species
- reactive oxygen species the species of reactive oxygen radicals that arise as a result of the transfer of electrons from the semiconductor substrate to the oxygen free molecules, which are much more reactive to the organic molecules in the cell wall structure of the microorganisms than the molecular oxygen itself.
- the energy of the forbidden band can be modified by a chemical process of impurification with metal ions, a process called chemical doping of semiconductor metallic oxide crystals.
- chemical doping process there are introduced, into the crystal structure of semiconductor metallic oxide of the T1O2 or ZnO type, transition metal atoms of the Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn type, or combinations thereof.
- impurities, in the form of metal ions introduced into the structure of metallic oxide crystal by chemical doping, modify the energy of the forbidden band and move to the visible spectrum the wavelength of the electromagnetic radiation required for the photocatalytic activation of the doped semiconductor metal oxides.
- the electromagnetic radiation in the visible spectral domain with wavelengths between 450 ⁇ 550 nm triggers photocatalytic chemical processes at the level of semiconductor metallic oxides of the Ti0 2 or ZnO type, which have been chemically doped with ions of transition metals of the Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn type, or combinations thereof.
- the present invention solves these technical problems of disinfection of glazed ceramic bodies, preferably glazed ceramic bodies for sanitary use, by making a biocidal photocatalytic ceramic glaze composition applied to the surfaces of ceramic products, of sanitary faience objects or ceramic tile surfaces, ceramic glaze containing, in its composition, pigments with bactericidal photocatalytic action made on the basis of doped Ti0 2 or ZnO doped metal oxides with transition metals of the Ag or Cu, Au, Ni, Fe, Cr, Co, Mn type, or combinations thereof.
- the photocatalytic activation method of the present invention uses light radiation from the visible spectrum to activate the photosensitizer particles in the ceramic glaze composition that has been applied to the surface of ceramic products, sanitary faience objects or to the surface of ceramic tiles.
- the light used is emitted in the visible spectral domain, having wavelengths between 450 ⁇ 550 nm. This light radiation is emitted by the lighting lamps in the respective rooms and irradiates the ceramic glaze deposited on the surfaces of ceramic products, of sanitary faience objects or on the surfaces of ceramic tiles.
- the photocatalytic semiconductor metal oxides of Ti0 2 or ZnO doped with Ag or Au, Cu, Ni, Fe, Cr, Co, Mn, or combinations thereof.
- Electromagnetic radiation emitted by the method described in the present invention, initiates the photocatalytic chemical process generated by semiconductor metallic oxide photosensitizers dispersed in the ceramic glaze composition.
- the photocatalytic chemical process triggered by the method described in the present invention, appears on the surface of the ceramic glaze and has the function of biocidal disinfection of the surfaces of the ceramic products, of the sanitary faience objects or of the surfaces of the ceramic tiles, surfaces that have been covered with the ceramic glaze according to the description of the present invention.
- the first technical problem that the present invention solves is to obtain a ceramic glaze composition with biocidal photocatalytic function.
- a ceramic glaze composition with biocidal photocatalytic function.
- Such a composition is composed of ingredients based on feldspar, sand, dolomite, alkali and alkaline-earth oxides, borax, plasticizers, color pigments, and whereat is added, in mass ratio, given the total mass of the composition, between 3 up to 20 parts of additive in the form of a biocidal photocatalytic agent, parts made of semiconductor metal oxide particles of the Ti0 2 or ZnO type doped in their crystal structure with transition metal ions such as Ag, or Cu, Au, Ni, Fe, Cr , Co, Mn or combinations thereof.
- Transition metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn or combinations thereof are added as dopants in the crystal structure of the semiconductor metal oxides of the Ti0 2 or ZnO type in proportions between 0.7 and up to 4.5 parts by weight, given the total weight of the semiconductor metal oxide.
- the additive based on doped semiconductor metal oxides is incorporated into the glaze mass by mixing and grinding into ball mills and then applied, by the technique and technologies known and used today in the ceramics industry, on ceramic products surfaces, sanitary faience objects or ceramic tiles.
- the semiconductor metal oxides of the Ti0 2 or ZnO type act as photosensitizers.
- the ceramic glaze in which was dispersed semiconductor metallic oxide of Ti0 2 or doped ZnO earns photocatalytic function.
- the wavelength of the electromagnetic radiation, which triggers photocatalytic chemical reactions when irradiating the semiconductor metal oxides in the ceramic glaze composition is given by the energy of the forbidden band.
- the energy of the forbidden band is equivalent to the irradiation of these oxides with the electromagnetic radiation emitted in the ultraviolet spectral range with lengths of 360 nm - 380 nm.
- the photocatalytic additive based on semiconductor metallic oxides of the Ti0 2 or ZnO type with electromagnetic radiation having the wavelength of the visible spectral domain, it is necessary to modify the energy of the forbidden band of these semiconductor oxides. Modification of the forbidden band energy of semiconductor oxides is obtained by introducing into the crystal structure of Ti0 2 or ZnO semiconductor metallic oxide some transition metal atoms of the Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn type, or combinations thereof.
- the process is known as chemical doping with metal impurities of semiconductor metal oxides.
- the chemical doping process achieves, in the spectral range between 450 nm and 550 nm, the wavelength of the electromagnetic radiation used to activate the photocatalytic chemical process generated by the doped metal oxides of the doped Ti0 2 or doped ZnO type.
- the ceramic glaze has photocatalytic properties.
- 0 2 1 D 9 or 0 2 appear as a result of electron transfer from the semiconductor metallic oxide substrate to free molecules of atmospheric oxygen, a process of energy transfer triggered by visible light irradiation.
- the photochemical excitation of neutral oxygen molecules results in their transformation into ROS (Reactive oxygen species, type 0 2 1 D 9 or 0 2 ⁇ 9 ).
- ROS reactive oxygen species, type 0 2 1 D 9 or 0 2 ⁇ 9 .
- Species of reactive oxygen radicals 0 2 1 D 9 or 0 2 ⁇ 9 have chemical affinity for bacterial or fungal microorganisms present on the ceramic glaze of ceramic product surfaces, sanitary faience objects or ceramic tile surfaces, and destroy the microorganisms present on said surfaces.
- Realization of this invention provides a continuous antimicrobial and antifungal protection and disinfection on the surface of ceramic products, sanitary faience objects or on the surface of ceramic tiles in medical offices, hospitals, schools, food industry, premises of food industry or, in general, in all areas and spaces that present the risk of infection and transmission of microbial germs.
- the second technical problem solved by the present invention is to provide a photocatalytic method of activating the photosensitizing additive made from doped Ti0 2 or doped ZnO type metallic oxide, dispersed in the composition of biocidal photocatalytic ceramic glaze, ceramic glaze applied to the ceramic surface, of sanitary faience objects or the surface of ceramic tiles.
- the photocatalytic activation method has the role of activating and initiating the disinfection function of the biocidal photocatalytic ceramic glaze by irradiating this biocidal photocatalytic ceramic glaze with photons emitted by the interior lighting lamps.
- Lamps also contain irradiation sources that emit continuous, pulsating or intermittent light in the spectral range between 450 nm and 550, and the electromagnetic radiation has the role to excite photocatalytic semiconductor metallic oxides dispersed in the ceramic glaze composition applied to the surfaces of ceramic products, of sanitary faience objects or on the surface of ceramic tiles.
- Semiconductor metal oxides of Ti0 2 or ZnO type have been doped into their crystal structure with transitional metals such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof, as described in the present invention.
- the method of photocatalytic activation, according to the invention by irradiating the glaze with light radiation from the visible spectrum generates triggering the phenomena of formation the singlet oxygen reactive species with disinfectant role on the surface of the ceramic glaze of the ceramic products, of the sanitary faience objects or on the surface of the ceramic tiles.
- the lamps used to achieve the photocatalytic activation method of the present invention can be fixed to the ceiling of the rooms or to the side walls of precincts, or are in the form of LED strips applied to the walls of the rooms, or are movable lamps that illuminate according to the disinfection requirements, and have different shapes, depending on the needs. Radiation using LED light sources is preferred.
- the photosensitizer activation spectrum made of semiconductor metal oxides Ti 0 2 or ZnO is shifted towards light waves emitted in the visible spectral field.
- Another object of the present invention is to provide a process for obtaining an additive for ceramic glazes comprising the following steps: - dissolving the semiconductor metal oxides of Ti0 2 or ZnO type, in a 0.5M-1 M NaOH solution, under stirring;
- dopant consisting of salts of the transition metals chosen from: Ag, Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof, so that the mass of doping metal is between 0.7 and up to 4.5 parts by weight, based on the total weight of the semiconductor metal oxide;
- the granulation reached in the milling step can be from 10 to 50 micrometers. Burning may occur at temperatures between 180-450 °C.
- the semiconductor metallic oxide of ZnO is doped with transitional metal by a wet or sol-gel process.
- To the reactor provided with a stirrer there are added 500 litters of 1 M NaOH solution into which 200 kg of ZnO is dissolved. The solution is shaken for 15-30 minutes.
- the raw ceramic tiles are prepared first, whereon the glaze will be applied, according to current technologies.
- the ceramic tiles are made from clay-silicate plastic material: quartz or quartz sand, silicates, allumosilicates (clays and feldspars), dolomite and limestone and the ceramic body of the tiles is shaped, thus representing the majority of the material that composes the ceramic tile.
- the "raw tiles” are either burnt before glazing (the tile undergoes a double combustion), or glazed and then burnt (the floor tile is made only by a process of a single burning).
- the raw tiles are sent on the belts to glazing, where the glaze is applied. After forming the raw tiles the preparation of the ceramic glaze mass is started.
- the raw materials based on feldspar, sand, dolomite, alkali and alkaline-earth oxides, borax, plasticizers, color pigments are weighed, whereat, from the tanks where they were stored after the preparation described above, the biocidal photocatalytic agent is added in an amount, given the total mass of the composition, of 3 to 20 parts of photocatalytic pigment of ZnO semiconductor metal oxide doped with monovalent Cu ions, prepared as above.
- the glaze composition thus formed is mixed in ball mills for homogenization, then a control of the fineness of the milling and a control of the respective batch against a manufacturing standard is made.
- the glazes are sieved with vibrating sieves, cleaned with magnetic deferrizers and then stored and homogenized in underground tanks provided with slow stirrers. From the storage tanks, with the help of membrane pumps, the glazes are pumped into smaller transfer tanks to the glazing and decoration belts.
- the glazing belts are supplied with raw ceramic tiles, faience or ceramic type tiles, and the glaze is applied by means of various machines, depending on the surface characteristics of the tile, the aesthetics and final planned texture.
- the existing equipment for applying glazes are: under pressure application systems with nozzles (airless), bells, under pressure dies, rotary disks.
- Example 2 Biocidal photocatalytic ceramic glaze composition It is disclosed an example of producing faiance tiles or ceramic tiles.
- the raw ceramic ties whereon the glaze will be applied are prepared first, according to current technologies, from clay-silicate materials: quartz or quartz sand, silicates, alluminosilicates (clays and feldspars), dolomite and limestone, and the ceramic body of tiles are shaped therefrom, representing most of the material that makes up the ceramic tile.
- the "raw tiles” are formed, being either burnt before glazing (the tile undergoes a double combustion), or glazed and then burnt (the ceramic tile is made only by a process of a single burning).
- the "raw tiles” are sent on belts to glazing, where the glaze is applied.
- the preparation of the ceramic glaze mass starts.
- a reactor provided with a stirrer there are added 500 liters of 1 M NaOH solution in which 200 kg of Ti0 2 is dissolved. The solution is shaken for 15-30 minutes. AgN0 3 is added slowly so that the mass of silver ions - Ag - is at a ratio between 0.7 and up to 1.5 parts by weight of Ti0 2 .
- the pH of the final solution is adjusted to a minimum of 8.5-9 by addition of 1 M NaOH solution.
- the glaze composition thus formed is mixed in ball mills for homogenization, then a control of the fineness of the milling and a control of the respective batch against a manufacturing standard, is performed.
- the glazes are sieved by means of vibrating sieves, cleaned with magnetic deferrizers and then stored and homogenized in underground tanks provided with slow stirrers. From the storage tanks, by means of membrane pumps, the glazes are pumped into smaller transfer tanks to the glazing and decoration belts.
- the glazing belts are supplied with raw ceramic tiles, faience or ceramic type tiles, and the glazing is applied by various machines, depending on the surface characteristics of the tile, the aesthetics and the final planned texture.
- the existing equipment for applying glazes are: under pressure application systems with nozzles (airless), bells, under pressure dies, rotary disks.
- ceramic objects including ceramic sanitary faienceed objects.
- ceramic objects including sanitary faience, are made up of two parts: the base - the ceramic mass that forms the body of the product, and the glaze - the superficial layer with decorative role, which covers the ceramic base and confers the specific properties of the ceramic objects, as mechanical strength, waterproofing, gloss. These two parts are joined by the combustion process. Also, different fusing agents are added to improve the rheological properties of the ceramic.
- the products are dried and the stages of vitrification of the unglazed faience are performed, operations prior to the glazing process. Separately, the glaze suspension wherein the doped photocatalytic pigment is added, is prepared.
- the ZnO semiconductor metallic oxide is doped with transitional metal ions by a wet or sol-gel process.
- There may be used Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn ions, or combinations thereof. Due to the electrochemical potentials of Zn and Cu ions, however, the use of doping ZnO semiconductor metal oxide with Cu (I) - Cu 2 0 oxide, monovalent copper oxide, is preferred.
- a reactor provided with the stirrer there are added 500 liters of 1 M NaOH solution in which 200 kg of ZnO is dissolved. The solution is shaken for 15-30 minutes.
- the raw materials based on feldspar, sand, dolomite, alkali and / or alkaline-earth oxides, borax, plasticizers, color pigments are weighed, whereat, from the tanks where it was stored after the preparation described above, the biocidal photocatalytic agent is added in an amount, given the total mass of the composition, of 3 to 20 parts of a photocatalytic additive of ZnO semiconductor metal oxide doped with monovalent Cu ions prepared as above.
- the glaze composition thus formed is mixed in ball mills for homogenization, then a control of the fineness of the milling and a control of the respective load against a manufacturing standard is carried out.
- the glazes are sieved by means of vibrating sieves, cleaned with magnetic deferrizers and then stored and homogenized in underground tanks provided with slow stirrers. From the storage tanks, by means of membrane pumps, the glazes are pumped into smaller transfer tanks to the glazing and decoration belts. Thereafter it follows the glaze coating stage of ceramic products - the base of the body.
- the existing equipment for applying glazes are: under pressure application systems with nozzles (airless), bells, under pressure dies, rotary disks.
- the final burning stage of ceramic products is performed, including those made of sanitary faience.
- the faience is burnt in the oven 2 times, the second burning being more powerful, at about 1350 - 1450 °C.
- dolomite this element conferring the well-known gloss of faience.
- ceramic tiles coated with glaze containing photocatalytic pigment of T1O2 or ZnO semiconductor metal oxide doped with transitional metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof, are prepared.
- the ceramic tiles are mounted by the known techniques on the walls or floors of the rooms.
- LED lighting lamps are installed on the ceilings or on the side walls.
- the lamps also contain sources also emitting electromagnetic radiation in the form of light quanta in the spectral range of from 450 nm to 550 nm. These LED lighting lamps illuminate the interior walls and floors of the precints that have been covered with photocatalytic ceramic tiles prepared according to the examples above.
- the electromagnetic radiation emitted by these bodies in the form of electromagnetic radiation from the spectral range between the wavelengths of 450 nm to 550 nm falls incidentally on the glaze of the ceramic tiles.
- the bactericidal and antifungal function is activated by triggering the photocatalytic processes from the level of additives based on semiconductor metallic oxides of T1O2 or ZnO type doped from the ceramic glaze structure.
- These photocatalytic processes determine the appearance of reactive oxygen species of singlet oxygen type ROS on the surface of ceramic tiles, species that destroy microorganisms.
- Example 5 of carrying out a photocatalytic disinfection method of the ceramic products surfaces and those covered with ceramic tiles
- ceramic products including sanitary faience ceramic ware which have been coated with glaze containing photocatalytic pigment of TiC>2 or ZnO semiconductor metal oxide doped with transitional metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn or combinations thereof, are prepared.
- LED-type lamps containing emitting and radiation sources are installed, emitting electromagnetic radiation in the form of electromagnetic radiation in the spectral range between the wavelengths of 450 nm to 550 nm.
- These lighting lamps with LED illuminate the ceramic products or sanitary faience objects, covered with ceramic glaze containing biocidal photocatalytic agent according to the examples above.
- the electromagnetic radiation emitted by these bodies in the form of electromagnetic radiation from the spectral range between 450 nm and 550 nm wavelength falls incidentally on the glaze of the ceramic tiles, triggering the photocatalytic processes at the level of additives based on semiconductor metallic oxides of Ti0 2 or ZnO type, contained in the ceramic glaze that covers ceramic products and sanitary faience objects.
- photocatalytic processes trigger, on the surface of the tiles, the appearance of reactive oxygen species of singlet oxygen ROS type, species that destroy the microorganisms from the surface of the ceramic glaze described in the present invention and deposited, by glazing, on ceramic products or sanitary faience objects, thus activating the bactericidal and antifungal function.
- continuous, pulsating or intermittent irradiation with electromagnetic radiation in the visible spectral range with wavelengths between 450 nm and 550 nm, light emitted by the ceiling or wall mounted lamps it is carried out a photocatalytic activation method of ceramic glaze covering ceramic products or sanitary faience objects that have been prepared as described in the present invention.
- the quantitative evaluation of the antimicrobial effect of the biocidal photocatalytic ceramic glaze composition was made by comparing the photocatalytic activation action generated by the irradiation with the wavelength in the visible spectral range between 450 nm and up to 550 nm of the photocatalytic composition prepared according to the above example, whereon viable bacterial cells were dispersed, at surface of the film or embedded in the ceramic mass.
- the quantitative evaluation of the antimicrobial effect of the biocidal ceramic glaze composition was made by comparing the effect of visible light radiation on viable bacterial cells embedded in the paint mass or dispersed on the surface of the film, and there was performed by determining the UFC / ml values (according to the standard method ISO 22196: 2007 adapted), expressed logarithmically.
Abstract
The invention refers to an additive for ceramic glazes, ceramic glaze, to an activation method and process for producing the additive. The additive is composed of particles of semiconductor metal oxides of the Ti02 or ZnO type, doped in a proportion between 0.7 and up to 4.5 parts by weight, based on the total weight of the semiconductor metal oxide, with ions of Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof. The composition comprises feldspar, sand, dolomite, alkali and / or alkaline earth oxides, borax to which is added, in mass ratio, between 3 to 20 parts of additive. The composition is used for glazing the surface of ceramic products, sanitary faience objects and the surface of ceramic tiles. It is presented a photocatalytic method of activating the photocatalytic additive in order to initiate the biocidal and disinfectant action, by irradiating the ceramic glaze with radiation in the visible domain having wavelengths between 450 nm şi 550 nm. There is also presented a process for obtaining an additive for ceramic glazes.
Description
DOPED TITANIA OR ZINC OXIDE ADDITIVE FOR CERAMIC GLAZES, CERAMIC GLAZE ACTIVATION METHOD AND PROCESS FOR PRODUCING THE ADDITIVE
The present invention refers to an additive for ceramic glazes, a composition of ceramic glaze, a method of activating the photocata lytic activity of ceramic glazes and to a process for making the additive.
Background art
One of the first examples of the application of semiconductor photocatalysis as a disinfection method has been presented in the work of Matsunaga et al. [T. Matsunaga, R. Tomoda, T. Nakajima, N. Nakamura, T. Komine, f ~ Q1 Appl. Environ. Microbiol. 54 (1988) pp. 1330]. They managed to demonstrate that Ti02 particles, by irradiation with light in the ultraviolet spectrum, were effective in photo-destruction of bacteria, such as Lactobacillus acidophilus, Saccharomyces cerevisiae, and Escherichia coli, and that the action of photo- destruction was associated with reduction of intracellular CoA level by photo-oxidation. In another study Cushnie et al. [T. P. T. Cushnie, P. K. J. Robertson, S. Officer, P. M Pollard, R. Prabhu, C. McCullagh, J. M. C. R.obertson Photobactericidal effects of Ti02 thin films at low temperatures - A preliminary study J. Photoch. Photobio. A, 216 (2010), pp. 290-294] demonstrated and evaluated the very good antibacterial efficacy of UV-activated Ti02 anatase on Staphylococcus aureus including in experiments performed at low temperatures. In another study, U. Joost et al. [U. Joost, K. Juganson, M. Visnapuu, M. Mortimer, A. Kahru, E. Nommiste, U. Joost, V. Kisand, A. Ivask, Photocatalytic antibacterial activity of nano-Ti02 (anatase)-based thin films: effects on Escherichia coli cells and fatty acids, Journal of Photochemistry and Photobiology B: Biology (2014)] have demonstrated the outstanding efficacy of UV-photocatalyzed Ti02 activated as a bactericidal agent on Escherichia coli. In another 2015 study, Fagan shows that Ti02 simply or doped with Ag, or Au, Cu, Ni has excellent photocatalytic bactericidal properties and explains the biocidal photocatalytic action mechanism of Ti02 [Fagan, R. et al., (2015) A review of solar and visible light active Ti02 photocatalysis for treating bacteria, cyanotoxins and contaminants of emerging concern, Materials Science in Semiconductor Processing, vol.42, pp. 2-14].
In the patent: DE202015000762U it is described a model of universal panel for lamps covered with Ti02 and which has a function of odor neutralization and a function of hygiene.
In the application WO201 1/1 13692A1 it is described a process for producing photocatalytic Ti02-coated plastic panels with biocidal properties.
In the application US 20140205546A1 it is described a process for producing a thin Ti02 polymeric film doped with silver.
The major disadvantage of these photocatalytic disinfection applications is that they use either UV radiation - which is dangerous for humans - or natural radiation from sunlight with very low quantum yields, for photocatalytic activation. For this reason, Ti02 photo disinfection has only applications that can be tolerated during long contact periods and where there is abundant sunlight, but the quantum yields, as well as the efficiency of the disinfection process, record fluctuations given by the intensity of the solar radiation.
In the application W09805601 it is described a hydraulic binder, a cement composition, a dry architectural concrete mixture containing photocatalyzed particles that are capable of oxidizing polluting substances in the presence of slight humidity of air and environment, added to most of the material. A preferred photocatalyst is titanium dioxide. These products are prepared by simply adding the photocatalyst to the desired formulation and then mixing according to any technique known in the art, by using both an automatic and a manual mixer. As Ti02 is added to the actual concrete formula, including added water, the mixing time required to obtain any reasonable dispersion must be long. The major disadvantage of this technique is the fact that, for the activation of the photosensitizer, it is necessary to irradiate it with light from the UV-A domain, which is in small quantities in the light radiation.
In the patent EP0633064B1 it is described a photocatalyst composite comprising a substrate having photocatalyst particles such as titanium oxide adhering thereto through a less degrading adhesive and a process for producing this composite. The least degrading adhesive is a silicon composite or cement. Substrates to be used include ceramics, glasses, plastics, elastomer, wood, paper and metal articles. Further, this patent provides
a coating composition comprising also a photocatalyst particle dispersion and an adhesive in a solvent. The major disadvantage of this technique is that, in order to activate the photosensitizer, it is necessary to radiate with light from the UV-A domain, which is in small quantities in the light radiation.
The patent US2006/0116279 discloses a method of preparing a composite based on semiconductor metal oxides such as titanium dioxide which is mixed with an inorganic material, such as silica or a Bronsted acid salt, preferably phosphate. The composite particles are produced by dry mixing under specific conditions, determined by selecting suitable parameters. The major disadvantage of this technique is that, in order to activate the photosensitizer, it is necessary to radiate with light from the UV-A domain, which is in small quantities in the light radiation.
The major disadvantage of these photocatalytic disinfection applications is that they use, for photocatalytic activation, either UV radiation - which is dangerous for humans - or natural radiation given by sunlight and, therefore, they have a very small quantum yield, taking into account that solar radiation contains less than 5% photons with specific wavelengths that activate the photosensitizers with Ti02. Therefore, Ti02 photodisinfection has only applications that can be tolerated during long contact periods, and where there is abundant sunlight, but the quantic yields, as well as the efficiency of the disinfection process, record fluctuations given by the intensity of the solar radiation.
In the patent application RO A2017 00801 it is described a washable paint composition containing a semiconductor metallic oxide of the Ti02 or ZnO type as a pigment, doped with transition metals such as Ag, Cu, Co, Cr, Mn, Ni, Fe to obtain a washable paint composition with photocatalytic properties, as well as a photocatalytic method of activating the photocatalytic composition. This composition has a very good biocidal and disinfectant photocatalytic activity. The disadvantage of this method and composition is due to the fact that the paint - the washable composition is not adherent to ceramic objects and ceramic tiles.
The disadvantages of the present techniques, giventhe use of pure Ti02, in ceramic glazes, are due to the fact that it also acts as a strong fusing agent (reduces the
combustion temperature), and is added in very small amounts. Due to its electronegativity, it reacts with the iron oxides in the composition of the glaze and intensifies the yellow color, thus damaging especially household ceramics. In reducing atmosphere, the pure Ti02 gives the glaze a blue color due to the increase in the amount of lower oxides, thus taking place electron transfer reactions that are not found in inert metal oxides.
In the process of obtaining a ceramic glaze, the use of semiconductor metal oxide nanoparticles has a number of technical disadvantages because they cannot be dissolved in the mass that will form the glaze raw material, the increased electronegativity of these particles leading to particle agglomerations difficult to disperse. At the same time, when the solution is deposited on the ceramic body and upon reaching the softening temperature, with the formation of the colloidal solution, the nanoparticles immediately form agglomerations which, upon cooling, crack the body of the glaze.
An object of the present invention is to provide an additive for ceramic glazes comprising a photocatalytic agent based on semiconductor metal oxides of the Ti02 or ZnO type, doped in their crystalline structure with transitional metal ions selected from: Ag, Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof, between 0.7 and up to 4.5 parts by weight, given the total weight of the semiconductor metal oxide.
In the composition of the additive for ceramic glazes there can be used metal oxides with a particle granulation of Ti02 or ZnO between 1 and 100 micrometers, for industrial use.
The additive as described can be used at a granulation of 10 to 50 micrometers.
Another object of the present invention is to provide a photocatalytic ceramic glaze composition comprising: 80-97 parts by weight, given the total weight of the composition, feldspar, sand, dolomite, alkali and / or alkaline-earth oxides, borax, plasticizers, color pigments; and between 3 to 20 parts by weight, given the total weight of the composition, of the additive according to the invention.
The composition of the photocatalytic ceramic glaze can be used to cover sanitary ceramic objects, sanitary porcelainor faience objects and ceramic tiles, on at least one surface.
The composition of biocidal photocatalytic ceramic glaze disclosed herein is a biocidal photocatalytic ceramic glaze composition which the surface of ceramic products, sanitary faience ware and ceramic tiles is covered with by glazing, and is made of feldspar, sand, dolomite, alkali and/ or alkaline-earth oxides, borax and whereat it is added in mass ratio, given the total mass of the composition, between 3 to 20 parts of a biocidal photocatalytic agent made of semiconductor metal oxide particles of the Ti02 or ZnO type, doped in their crystalline structure with transitional metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof. Transition metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn are added as dopants in the crystalline structure of the semiconductor metal oxides of the Ti02 or ZnO type in ratios ranging from 0.7 to 4.5 parts by weight, given the total weight of the semiconductor metal oxide. The doping modifies the energy of the forbidden band. In this way the semiconductor metal oxides can be excited by the light radiation from the visible spectrum and can trigger a series of phenomena with disinfectant biocidal photocatalytic properties. The biocidal photocatalytic ceramic glaze is applied by known technologies on the surface of ceramic products, sanitary faience ware or on the surface of ceramic tiles.
By exposing these ceramic objects to light, from the visible spectral domain with wavelengths 450 ÷ 550 nm, they develop a biocide activity.
It is also described a photocatalytic method of activating the doped semiconductor metallic oxide photosensitizer, dispersed in the composition of the biocidal photocatalytic ceramic glaze described above, which consisted of exposing the glazed surfaces to a light source emitting at wavelengths of 450 ÷ 550 nm. The light source can be a LED indoor lighting source, which also emits quanta from the visible spectrum with a wavelength ranging between 450 ÷ 550 nm.
The irradiation can be permanent or intermittent, depending on the needs, thus realising the photocatalytic activation of the semiconductor metal oxide doped and dispersed in the ceramic glaze composition. The light that irradiates the ceramic glaze generates, at the level of the semiconductor metallic oxide in the glaze, the initiation of the chemical process of photocatalysis. The chemical process of photocatalysis generated by the semiconductor metallic oxide type photosensitizer, doped and dispersed in the ceramic glaze composition
D
applied on the surfaces of ceramic products, sanitary faience objects or on the surface of ceramic tiles, has the role of realizing the phenomenon of biocidal disinfection on the microorganisma which came into contact with the ceramic glaze. By using this ceramic glaze composition and activation method, described in the present invention, the antimicrobial and antifungal disinfection and protection of the surfaces of ceramic products, sanitary faience objects or the surface of ceramic tiles in medical offices, hospitals, schools, food industry is achieved, generally in all areas where there is a danger of the occurrence and spread of microbial germs.
Semiconductor metal oxides act as a photosensitizer in photocatalytic reactions. The photocatalytic effect is determined by the energy of the forbidden band. For semiconductor metallic oxides of the Ti02 or ZnO type, the band energy is of 3.2 eV - 3.3 eV, and it corresponds to the near ultraviolet spectral domain, with wavelengths of 360 nm - 380 nm. The generation of photocatalytic chemical reactions is obtained when the semiconductor metal oxide of the Ti02 or ZnO type is excited by the light energy equal to or greater than the bandwidth of the forbidden band. The effect and mode of action in the photodynamic therapy of photosensitizers based on photochemical reactions are known.
These reactions are triggered by the interaction of a photosensitive substance with light at a certain wavelength, and form reactive species of the singlet oxygen of the ROS type ( of
02 1D9 or 02
type). The disinfectant action of the semiconductor metallic oxide photosensitizers of the Ti02 or ZnO type is achieved by the appearance of this photocatalytic mechanism, triggered by the interaction of the photosensitizing agent, which contains the semiconductor metallic oxides of the Ti02 or ZnO type, with a light of a certain wavelength, as a result appearing the reactive oxygen species - oxygen singlet ROS, reactive species with a decisive role in the destruction of microorganisms, and which give these reactive species bactericidal and antifungal role.
By ROS (Reactive oxygen species) there are meant the species of reactive oxygen radicals that arise as a result of the transfer of electrons from the semiconductor substrate to the oxygen free molecules, which are much more reactive to the organic molecules in the cell wall structure of the microorganisms than the molecular oxygen itself.
In this way, a controlled process of disinfection of the interior surfaces is obtained, adjustable by the light intensity, according to the needs of disinfection, and reproducible, without being influenced by the variation of the external light factors.
In semiconductor metal oxides, the energy of the forbidden band can be modified by a chemical process of impurification with metal ions, a process called chemical doping of semiconductor metallic oxide crystals. Through the chemical doping process there are introduced, into the crystal structure of semiconductor metallic oxide of the T1O2 or ZnO type, transition metal atoms of the Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn type, or combinations thereof. These impurities, in the form of metal ions, introduced into the structure of metallic oxide crystal by chemical doping, modify the energy of the forbidden band and move to the visible spectrum the wavelength of the electromagnetic radiation required for the photocatalytic activation of the doped semiconductor metal oxides. More exactly, the electromagnetic radiation in the visible spectral domain with wavelengths between 450 ÷ 550 nm triggers photocatalytic chemical processes at the level of semiconductor metallic oxides of the Ti02 or ZnO type, which have been chemically doped with ions of transition metals of the Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn type, or combinations thereof.
The present invention solves these technical problems of disinfection of glazed ceramic bodies, preferably glazed ceramic bodies for sanitary use, by making a biocidal photocatalytic ceramic glaze composition applied to the surfaces of ceramic products, of sanitary faience objects or ceramic tile surfaces, ceramic glaze containing, in its composition, pigments with bactericidal photocatalytic action made on the basis of doped Ti02 or ZnO doped metal oxides with transition metals of the Ag or Cu, Au, Ni, Fe, Cr, Co, Mn type, or combinations thereof. Using light radiation from the visible spectrum, it is described a photocatalytic method of activating the photosensitizer particles in the ceramic glaze composition that has been applied to the surface of ceramic products, sanitary faience objects or to the surface of ceramic tiles. In the photocatalytic activation method of the present invention, the light used is emitted in the visible spectral domain, having wavelengths between 450 ÷ 550 nm. This light radiation is emitted by the lighting lamps in the respective rooms and irradiates the ceramic glaze deposited on the surfaces of ceramic products, of sanitary faience objects or on the surfaces of ceramic tiles. By the
irradiation of the ceramic glaze there are activated the photocatalytic semiconductor metal oxides of Ti02 or ZnO, doped with Ag or Au, Cu, Ni, Fe, Cr, Co, Mn, or combinations thereof. Electromagnetic radiation, emitted by the method described in the present invention, initiates the photocatalytic chemical process generated by semiconductor metallic oxide photosensitizers dispersed in the ceramic glaze composition. The photocatalytic chemical process, triggered by the method described in the present invention, appears on the surface of the ceramic glaze and has the function of biocidal disinfection of the surfaces of the ceramic products, of the sanitary faience objects or of the surfaces of the ceramic tiles, surfaces that have been covered with the ceramic glaze according to the description of the present invention.
The first technical problem that the present invention solves is to obtain a ceramic glaze composition with biocidal photocatalytic function. Such a composition is composed of ingredients based on feldspar, sand, dolomite, alkali and alkaline-earth oxides, borax, plasticizers, color pigments, and whereat is added, in mass ratio, given the total mass of the composition, between 3 up to 20 parts of additive in the form of a biocidal photocatalytic agent, parts made of semiconductor metal oxide particles of the Ti02 or ZnO type doped in their crystal structure with transition metal ions such as Ag, or Cu, Au, Ni, Fe, Cr , Co, Mn or combinations thereof. Transition metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn or combinations thereof are added as dopants in the crystal structure of the semiconductor metal oxides of the Ti02 or ZnO type in proportions between 0.7 and up to 4.5 parts by weight, given the total weight of the semiconductor metal oxide.
The additive based on doped semiconductor metal oxides is incorporated into the glaze mass by mixing and grinding into ball mills and then applied, by the technique and technologies known and used today in the ceramics industry, on ceramic products surfaces, sanitary faience objects or ceramic tiles. In photocatalytic reactions, the semiconductor metal oxides of the Ti02 or ZnO type act as photosensitizers. The ceramic glaze in which was dispersed semiconductor metallic oxide of Ti02 or doped ZnO earns photocatalytic function. The wavelength of the electromagnetic radiation, which triggers photocatalytic chemical reactions when irradiating the semiconductor metal oxides in the ceramic glaze composition, is given by the energy of the forbidden band. In the case of
Ti02 and ZnO the energy of the forbidden band is equivalent to the irradiation of these oxides with the electromagnetic radiation emitted in the ultraviolet spectral range with lengths of 360 nm - 380 nm. In order to activate the photocatalytic additive based on semiconductor metallic oxides of the Ti02 or ZnO type with electromagnetic radiation having the wavelength of the visible spectral domain, it is necessary to modify the energy of the forbidden band of these semiconductor oxides. Modification of the forbidden band energy of semiconductor oxides is obtained by introducing into the crystal structure of Ti02 or ZnO semiconductor metallic oxide some transition metal atoms of the Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn type, or combinations thereof. The process is known as chemical doping with metal impurities of semiconductor metal oxides. The chemical doping process achieves, in the spectral range between 450 nm and 550 nm, the wavelength of the electromagnetic radiation used to activate the photocatalytic chemical process generated by the doped metal oxides of the doped Ti02 or doped ZnO type. By dispersing doped semiconductor metal oxides in its composition, the ceramic glaze has photocatalytic properties. More exactly, when irradiating ceramic glaze from the visible spectral domain with the wavelength between 450 nm and 550, there is initiated, by the photosensitizers in the composition of the glaze, a series of photocatalytic chemical processes with biocidal disinfectant action on the surface of ceramic products, of sanitary faience objects or the surface of the ceramic tiles, the ceramic glaze covering them being prepared according to the description of the present invention. When illuminated with visible light, the semiconductor metal oxides of the doped Ti02 or doped ZnO type are excited with energy equal to or greater than the energy of the forbidden band and photocatalytic chemical reactions occur at the photosensitizer level. The photocatalytic chemical reactions thus generated result in the formation of singlet-type reactive oxygen species, also called ROS
(Reactive oxygen species, type 02 1D9 or 02
). Species of reactive oxygen radicals
02 1D9 or 02 appear as a result of electron transfer from the semiconductor metallic oxide substrate to free molecules of atmospheric oxygen, a process of energy transfer triggered by visible light irradiation. The photochemical excitation of neutral oxygen molecules results in their transformation into ROS (Reactive oxygen species, type 02 1D9 or 02 å9 ). Species of reactive oxygen radicals 02 1D9 or 02 å9 have chemical affinity
for bacterial or fungal microorganisms present on the ceramic glaze of ceramic product surfaces, sanitary faience objects or ceramic tile surfaces, and destroy the microorganisms present on said surfaces. By irradiation with electromagnetic radiation from the visible field, a photocatalytic biocidal disinfection phenomenon of the ceramic surfaces that have been coated with ceramic glaze prepared and applied according to the description of the present invention is obtained. Realization of this invention provides a continuous antimicrobial and antifungal protection and disinfection on the surface of ceramic products, sanitary faience objects or on the surface of ceramic tiles in medical offices, hospitals, schools, food industry, premises of food industry or, in general, in all areas and spaces that present the risk of infection and transmission of microbial germs.
The second technical problem solved by the present invention is to provide a photocatalytic method of activating the photosensitizing additive made from doped Ti02 or doped ZnO type metallic oxide, dispersed in the composition of biocidal photocatalytic ceramic glaze, ceramic glaze applied to the ceramic surface, of sanitary faience objects or the surface of ceramic tiles. The photocatalytic activation method has the role of activating and initiating the disinfection function of the biocidal photocatalytic ceramic glaze by irradiating this biocidal photocatalytic ceramic glaze with photons emitted by the interior lighting lamps. Lamps also contain irradiation sources that emit continuous, pulsating or intermittent light in the spectral range between 450 nm and 550, and the electromagnetic radiation has the role to excite photocatalytic semiconductor metallic oxides dispersed in the ceramic glaze composition applied to the surfaces of ceramic products, of sanitary faience objects or on the surface of ceramic tiles. Semiconductor metal oxides of Ti02 or ZnO type have been doped into their crystal structure with transitional metals such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof, as described in the present invention. The method of photocatalytic activation, according to the invention, by irradiating the glaze with light radiation from the visible spectrum generates triggering the phenomena of formation the singlet oxygen reactive species with disinfectant role on the surface of the ceramic glaze of the ceramic products, of the sanitary faience objects or on the surface of the ceramic tiles.
The lamps used to achieve the photocatalytic activation method of the present invention can be fixed to the ceiling of the rooms or to the side walls of precincts, or are in the form of LED strips applied to the walls of the rooms, or are movable lamps that illuminate according to the disinfection requirements, and have different shapes, depending on the needs. Radiation using LED light sources is preferred.
The present invention has the following advantages:
• The use of additives based on metal oxides of Ti02 or ZnO doped with transition metals such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof having particle sizes in the micrometer order does not require special working conditions, they are easy to handle and store, they do not require protective measures to avoid possible toxic effects as in the case of using metal oxide particles of nanometer order.
• By doping semiconductor metal oxides with transitional metal ions such as Ag or Cu, Au, Ni, Fe Cr, Co, or Mn, or combinations thereof, the photosensitizer activation spectrum made of semiconductor metal oxides Ti 02 or ZnO is shifted towards light waves emitted in the visible spectral field.
• Making a total coating by using an antibacterial protection material of the interior walls covered with ceramic tiles and ceramic products or sanitary faience objects, eliminating the transmission of nosocomial infections,
• By applying the present invention, using light radiation from the visible field, a phenomenon of continuous bactericidal disinfection of the enclosures is obtained in which there is a danger of the emergence and spread of microbial germs with nosocomial potential.
• This eliminates the need for the use of UV-sensitive photosensitizer, which is dangerous for humans.
• Ease in the composition manufacturing process, because the doped semiconductor metal oxide photosensitizers used are fully compatible with the existing technologies used at present.
Another object of the present invention is to provide a process for obtaining an additive for ceramic glazes comprising the following steps:
- dissolving the semiconductor metal oxides of Ti02 or ZnO type, in a 0.5M-1 M NaOH solution, under stirring;
- slow addition of dopant consisting of salts of the transition metals chosen from: Ag, Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof, so that the mass of doping metal is between 0.7 and up to 4.5 parts by weight, based on the total weight of the semiconductor metal oxide;
- adjusting the pH of the mixture to 8.5 ÷ 9 by adding 0.5M-1 M NaOH basic solution;
- stirring the suspension for 1 hour up to 3 hours;
- decanting the excess water;
- drying, followed by burning;
- slow cooling of the product resulting from the burning, and
- ball milling.
The granulation reached in the milling step can be from 10 to 50 micrometers. Burning may occur at temperatures between 180-450 °C.
EXAMPLES OF CARRYING OUT THE INVENTION Example 1 - Biocidal photocatalytic ceramic glaze composition
It is presented an example of producing faience tiles or ceramic tiles. First the semiconductor metallic oxide of ZnO is doped with transitional metal by a wet or sol-gel process. There can be used Ag ions, or Cu, Au, Ni, Fe, Cr, Co, Mn ions, or combinations thereof. Due to the electrochemical potentials of Zn and Cu ions, however, the use of doping ZnO semiconductor metal oxide with Cu (I) - Cu20 monovalent cuprous oxide is preferred. To the reactor provided with a stirrer there are added 500 litters of 1 M NaOH solution into which 200 kg of ZnO is dissolved. The solution is shaken for 15-30 minutes. Slowly copper oxide (I) - Cu20 - is added, so that the mass of copper (I) - Cu+ - is in a ratio between 2.5 and up to 4.5 parts of the ZnO mass. The pH of the final solution is adjusted to a minimum of 8.5 - 9 by addition of 1 M NaOH solution. It is shaken for 1 hour. The excess water is decanted, dried and then burnt at a temperature of 450 0 C. It is then cooled slowly and the burnt mass is brought to the corresponding granulation by grinding into ball mills. After the photocatalytic pigment is brought to the corresponding granulation,
it is stored in storage tanks wherefrom it will be introduced into the manufacturing process of the glaze suspension. Separately the raw ceramic tiles are prepared first, whereon the glaze will be applied, according to current technologies. The ceramic tiles are made from clay-silicate plastic material: quartz or quartz sand, silicates, allumosilicates (clays and feldspars), dolomite and limestone and the ceramic body of the tiles is shaped, thus representing the majority of the material that composes the ceramic tile. After receiving, shredding, homogenization and storage of the raw materials, they are grinded, process by which the barbotine is formed. It follows the atomization of the barbotine and the formation of the plastic ceramic powder wherefrom the "ceramic tile" is formed by pressing, in the required and possible product formats, then drying in fast dryers, becoming "raw tiles". The "raw tiles" are either burnt before glazing (the tile undergoes a double combustion), or glazed and then burnt (the floor tile is made only by a process of a single burning). The raw tiles are sent on the belts to glazing, where the glaze is applied. After forming the raw tiles the preparation of the ceramic glaze mass is started. The raw materials based on feldspar, sand, dolomite, alkali and alkaline-earth oxides, borax, plasticizers, color pigments are weighed, whereat, from the tanks where they were stored after the preparation described above, the biocidal photocatalytic agent is added in an amount, given the total mass of the composition, of 3 to 20 parts of photocatalytic pigment of ZnO semiconductor metal oxide doped with monovalent Cu ions, prepared as above. In this phase, the glaze composition thus formed is mixed in ball mills for homogenization, then a control of the fineness of the milling and a control of the respective batch against a manufacturing standard is made. After grinding and control, the glazes are sieved with vibrating sieves, cleaned with magnetic deferrizers and then stored and homogenized in underground tanks provided with slow stirrers. From the storage tanks, with the help of membrane pumps, the glazes are pumped into smaller transfer tanks to the glazing and decoration belts. The glazing belts are supplied with raw ceramic tiles, faience or ceramic type tiles, and the glaze is applied by means of various machines, depending on the surface characteristics of the tile, the aesthetics and final planned texture. The existing equipment for applying glazes are: under pressure application systems with nozzles (airless), bells, under pressure dies, rotary disks.
Example 2 - Biocidal photocatalytic ceramic glaze composition
It is disclosed an example of producing faiance tiles or ceramic tiles. The raw ceramic ties whereon the glaze will be applied are prepared first, according to current technologies, from clay-silicate materials: quartz or quartz sand, silicates, alluminosilicates (clays and feldspars), dolomite and limestone, and the ceramic body of tiles are shaped therefrom, representing most of the material that makes up the ceramic tile. The "raw tiles" are formed, being either burnt before glazing (the tile undergoes a double combustion), or glazed and then burnt (the ceramic tile is made only by a process of a single burning). The "raw tiles" are sent on belts to glazing, where the glaze is applied. After forming the raw tiles, the preparation of the ceramic glaze mass starts. First the doping of the Ti02 semiconductor metal oxide with transitional metal ions by a wet or sol-gel procedure is performed. There may be used Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn ions, or combinations thereof. In a reactor provided with a stirrer there are added 500 liters of 1 M NaOH solution in which 200 kg of Ti02 is dissolved. The solution is shaken for 15-30 minutes. AgN03 is added slowly so that the mass of silver ions - Ag - is at a ratio between 0.7 and up to 1.5 parts by weight of Ti02. The pH of the final solution is adjusted to a minimum of 8.5-9 by addition of 1 M NaOH solution. It is continuously shaken for 3 hours. The excess water is decanted, dried and then burnt at 180 ° C. It is then cooled slowly and the burnt mass is brought to the corresponding granulation by grinding into ball mills. The raw materials based on feldspar, sand, dolomite, alkali and / or alkaline-earth oxides, borax, plasticizers, color pigments are weighed, whereat, from the tanks where it was stored after the preparation described above, the biocidal photocatalytic agent is added in an amount, given the total mass of the composition, of 3 to 20 parts of the photocatalytic additive of Ti02 semiconductor metal oxide doped with Ag ions prepared as above. In this phase, the glaze composition thus formed is mixed in ball mills for homogenization, then a control of the fineness of the milling and a control of the respective batch against a manufacturing standard, is performed. After grinding and control, the glazes are sieved by means of vibrating sieves, cleaned with magnetic deferrizers and then stored and homogenized in underground tanks provided with slow stirrers. From the storage tanks, by means of membrane pumps, the glazes are pumped into smaller transfer tanks to the glazing and decoration belts. The glazing belts are supplied with raw ceramic tiles, faience or ceramic type tiles, and the glazing is applied by various machines, depending on the surface
characteristics of the tile, the aesthetics and the final planned texture. The existing equipment for applying glazes are: under pressure application systems with nozzles (airless), bells, under pressure dies, rotary disks.
Example 3 - Biocidal photocatalytic ceramic glaze composition
It is presented an example of producing ceramic products, including ceramic sanitary faienceed objects. From the point of view of the composition, ceramic objects, including sanitary faience, are made up of two parts: the base - the ceramic mass that forms the body of the product, and the glaze - the superficial layer with decorative role, which covers the ceramic base and confers the specific properties of the ceramic objects, as mechanical strength, waterproofing, gloss. These two parts are joined by the combustion process. Also, different fusing agents are added to improve the rheological properties of the ceramic. The products are dried and the stages of vitrification of the unglazed faience are performed, operations prior to the glazing process. Separately, the glaze suspension wherein the doped photocatalytic pigment is added, is prepared. First the ZnO semiconductor metallic oxide is doped with transitional metal ions by a wet or sol-gel process. There may be used Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn ions, or combinations thereof. Due to the electrochemical potentials of Zn and Cu ions, however, the use of doping ZnO semiconductor metal oxide with Cu (I) - Cu20 oxide, monovalent copper oxide, is preferred. In a reactor provided with the stirrer there are added 500 liters of 1 M NaOH solution in which 200 kg of ZnO is dissolved. The solution is shaken for 15-30 minutes. Slowly copper (I) - Cu20 oxide is added, so that the mass of copper (I) - Cu+ ions to be at a ratio of 2.5 to 4.5 parts of the ZnO mass. The pH of the final solution is adjusted to a minimum of 8.5-9 by addition of 1 M NaOH solution. It is shaken for 1 hour. Excess water is decanted, dried and then burnt at a temperature of 450 ° C. It is then cooled slowly, and the burnt mass is brought to the corresponding granulation by grinding into ball mills. The raw materials based on feldspar, sand, dolomite, alkali and / or alkaline-earth oxides, borax, plasticizers, color pigments are weighed, whereat, from the tanks where it was stored after the preparation described above, the biocidal photocatalytic agent is added in an amount, given the total mass of the composition, of 3 to 20 parts of a photocatalytic additive of ZnO semiconductor metal oxide doped with monovalent Cu ions
prepared as above. In this stage, the glaze composition thus formed is mixed in ball mills for homogenization, then a control of the fineness of the milling and a control of the respective load against a manufacturing standard is carried out. After grinding and control, the glazes are sieved by means of vibrating sieves, cleaned with magnetic deferrizers and then stored and homogenized in underground tanks provided with slow stirrers. From the storage tanks, by means of membrane pumps, the glazes are pumped into smaller transfer tanks to the glazing and decoration belts. Thereafter it follows the glaze coating stage of ceramic products - the base of the body. The existing equipment for applying glazes are: under pressure application systems with nozzles (airless), bells, under pressure dies, rotary disks. After glazing, the final burning stage of ceramic products is performed, including those made of sanitary faience. The faience is burnt in the oven 2 times, the second burning being more powerful, at about 1350 - 1450 °C. In the glaze covering the sanitary faience there may be added dolomite, this element conferring the well-known gloss of faience.
Exemple 4 of carrying out a photocatalytic disinfection method of the ceramic products surfaces and those covered with ceramic tiles
According to one of the methods described above, ceramic tiles coated with glaze containing photocatalytic pigment of T1O2 or ZnO semiconductor metal oxide doped with transitional metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof, are prepared. The ceramic tiles are mounted by the known techniques on the walls or floors of the rooms. After mounting the ceramic tiles, LED lighting lamps are installed on the ceilings or on the side walls. The lamps also contain sources also emitting electromagnetic radiation in the form of light quanta in the spectral range of from 450 nm to 550 nm. These LED lighting lamps illuminate the interior walls and floors of the precints that have been covered with photocatalytic ceramic tiles prepared according to the examples above. The electromagnetic radiation emitted by these bodies in the form of electromagnetic radiation from the spectral range between the wavelengths of 450 nm to 550 nm falls incidentally on the glaze of the ceramic tiles. In this way, the bactericidal and antifungal function is activated by triggering the photocatalytic processes from the level of additives based on semiconductor metallic oxides of T1O2 or ZnO type doped from the
ceramic glaze structure. These photocatalytic processes determine the appearance of reactive oxygen species of singlet oxygen type ROS on the surface of ceramic tiles, species that destroy microorganisms. By continuous, pulsating or intermittent irradiation with light from the visible spectral range having the wavelength between 450 nm to 550 nm, light emitted by the lamps mounted on the ceiling or on the wall, it is realized a photocatalytic activation method of the ceramic, faience tiles and floor tiles with ceramic glaze prepared according to the description of the present invention, providing the disinfection of the interior walls of the rooms at risk of occurrence and spread of nosocomial infections.
Example 5 of carrying out a photocatalytic disinfection method of the ceramic products surfaces and those covered with ceramic tiles
According to the methods described above, ceramic products, including sanitary faience ceramic ware which have been coated with glaze containing photocatalytic pigment of TiC>2 or ZnO semiconductor metal oxide doped with transitional metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn or combinations thereof, are prepared. After assembling by known techniques the ceramic products and sanitary faience objects which were covered with ceramic glaze as described in the above examples, LED-type lamps containing emitting and radiation sources are installed, emitting electromagnetic radiation in the form of electromagnetic radiation in the spectral range between the wavelengths of 450 nm to 550 nm. These LED lamps, described above, can also be installed in rooms where ceramic products or sanitary faience objects are used. These lighting lamps with LED illuminate the ceramic products or sanitary faience objects, covered with ceramic glaze containing biocidal photocatalytic agent according to the examples above. The electromagnetic radiation emitted by these bodies in the form of electromagnetic radiation from the spectral range between 450 nm and 550 nm wavelength falls incidentally on the glaze of the ceramic tiles, triggering the photocatalytic processes at the level of additives based on semiconductor metallic oxides of Ti02 or ZnO type, contained in the ceramic glaze that covers ceramic products and sanitary faience objects. These photocatalytic processes trigger, on the surface of the tiles, the appearance of reactive oxygen species of singlet oxygen ROS type, species that destroy the microorganisms from the surface of the
ceramic glaze described in the present invention and deposited, by glazing, on ceramic products or sanitary faience objects, thus activating the bactericidal and antifungal function. By continuous, pulsating or intermittent irradiation with electromagnetic radiation in the visible spectral range with wavelengths between 450 nm and 550 nm, light emitted by the ceiling or wall mounted lamps, it is carried out a photocatalytic activation method of ceramic glaze covering ceramic products or sanitary faience objects that have been prepared as described in the present invention. This ensures the disinfection of ceramic products or sanitary faience objects subjected to the risk of occurrence and spread of nosocomial infections. These photocatalytic processes trigger, at the surface of ceramic products and sanitary faience objects, the occurrence of reactive oxygen species of singlet oxygen ROS type, species that destroy microorganisms from the surface of ceramic products or sanitary faience objects. This method activates the bactericidal and antifungal function of the ceramic glaze in which semiconductor metal oxides of the doped Ti02 or ZnO type were dispersed. By continuous, pulsing or intermittent irradiation with electromagnetic radiation in the visible spectral range between 450 nm and up to 550 nm by the LED lamps in the respective precints, a method of photocatalytic activation of ceramic products or faience sanitary objects glazed with ceramic glaze, prepared according to the description of the present invention, is realised, providing the disinfection of ceramic products or sanitary faience objects subjected to the risk of occurrence and spread of nosocomial infections.
The quantitative evaluation of the antimicrobial effect of the biocidal photocatalytic ceramic glaze composition was made by comparing the photocatalytic activation action generated by the irradiation with the wavelength in the visible spectral range between 450 nm and up to 550 nm of the photocatalytic composition prepared according to the above example, whereon viable bacterial cells were dispersed, at surface of the film or embedded in the ceramic mass.
Laboratory tests were performed for quantitative evaluation of the antimicrobial effect of the biocidal photocatalytic ceramic glaze composition. First there were prepared identical batches of viable bacterial cell biological samples, selected from several types of microbiological strains, which were dispersed on ceramic glaze surfaces or embedded in
glazed ceramic mass, ceramic mass prepared by grinding for experiments, ceramic glaze prepared according to the examples of the present invention and containing a biocidal photocatalytic agent composed of semiconductor metal oxides of the Ti02 or ZnO type which have been doped with transitional metal ions such as Ag, or Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof. One batch of biological samples was exposed to darkness, another to sunlight, and yet another one was performed the photocatalytic activation of the composition, by light irradiation in the visible spectral range with wavelengths between 450 nm and up to 550 nm.
The quantitative evaluation of the antimicrobial effect of the biocidal ceramic glaze composition, activated by photocatalytic methods of light irradiation in the visible spectral range with wavelengths between 450 nm and up to 550 nm, was made by comparing the effect of visible light radiation on viable bacterial cells embedded in the paint mass or dispersed on the surface of the film, and there was performed by determining the UFC / ml values (according to the standard method ISO 22196: 2007 adapted), expressed logarithmically. The results showed a logarithmic reduction of the UFC / ml values of more than 3 units in the case of the samples that were in contact with the ceramic glaze mass exposed to light in the visible spectral range with wavelengths between 450 nm and up to 550 nm, compared to the values obtained for the same samples, but exposed to natural light, under the same conditions.
Claims
1. A ceramic glaze additive characterized in that it comprises a photocatalytic agent based on semiconductor metal oxides of the Ti02 or ZnO type, doped in their crystalline structure with ions of the transition metals chosen from: Ag, Cu, Au, Ni, Fe, Cr, Co, Mn, or combinations thereof, between 0.7 and up to 4.5 parts by weight, based on the total weight of the semiconductor metal oxide.
2. Additive according to claim 1 , wherein the particle granulation of Ti02 or ZnO is between 1 and 100 micrometers.
3. Additive according to claim 1 or 2, wherein the semiconductor metal oxides are pigments for industrial use.
4. Additive according to claims 1 to 3, wherein the granulation of the additive is from 10 to 50 micrometers.
5. A photocatalytic ceramic glaze composition comprising:
- 80-97 parts by weight, based on the total weight of the composition, feldspar, sand, dolomite, alkali and / or alkaline-earth oxides, borax, plasticizers, color pigments;
- between 3 to 20 parts by weight, based on the total weight of the composition, of the additive according to claims 1 - 4.
6. A ceramic object coated on at least one surface with photocatalytic ceramic glaze according to the composition of claim 5.
7. Ceramic object according to claim 6, which develops biocidal activity by exposure to light in the visible spectral range with wavelengths of 450 ÷ 550 nm.
8. Use of the ceramic glaze composition according to claim 5 for coating ceramic sanitary objects, sanitary porcelain or faience objects and ceramic tiles.
9. A method of activating the photocatalytic activity of the ceramic glaze according to claim 5, applied to an object, characterized in that the glazed surface is exposed to a light source emitting at wavelengths of 450 ÷ 550 nm.
10. Activation method according to claim 9, wherein the glazed surface of the object is exposed to a LED lighting source.
11. Method of claim 9 or 10 wherein the exposure to the lighting source is permanent or intermittent.
12. A process for obtaining an additive for ceramic glazes according to claims 1 - 4, comprising the steps:
- dissolving the semiconductor metal oxides of Ti02 or ZnO type, in a 0.5M-1 M NaOH solution, under shaking;
- slow addition of dopant consisting of salts of the transition metals chosen from: Ag, Cu, Au, Ni, Fe, Cr, Co, Mn or combinations thereof, so that the mass of doping metal is between 0.7 and up to 4 , 5 parts by weight, based on the total weight of the semiconductor metal oxide;
- adjusting the pH of the mixture to 8.5 ÷ 9 by adding 0.5M-1 M NaOH basic solution;
- shaking the suspension for 1 hour up to 3 hours;
- decanting the excess water;
- drying, followed by burning;
- slow cooling of the product resulting from burning, and
- ball milling.
13. Process of claim 12 wherein the granulation in the milling stage is from 10 to 50 micrometers.
14. Process of claim 12 wherein burning takes place at temperatures between 180-450° C.
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| ROA201800793A RO134047A2 (en) | 2018-10-11 | 2018-10-11 | Photocatalytic biocidal ceramic glaze composition and a photocatalytic method for disinfection of surfaces of ceramic products, porcelain sanitary objects and ceramic-tile lined surfaces |
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| WO2020076177A1 true WO2020076177A1 (en) | 2020-04-16 |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112535952A (en) * | 2020-12-23 | 2021-03-23 | 常州北化澳联环保科技有限公司 | Preparation method of ceramic tile for purifying VOCs (volatile organic compounds) |
| CN113860887A (en) * | 2021-10-22 | 2021-12-31 | 新明珠集团股份有限公司 | Ceramic plate and preparation method thereof |
| CN114516763A (en) * | 2022-03-07 | 2022-05-20 | 安徽鑫民玻璃股份有限公司 | Sintering method of colored ceramic glaze for wine bottle production |
| CN116375449A (en) * | 2023-05-29 | 2023-07-04 | 佛山市和昇昌生物科技有限公司 | Formaldehyde-removing ceramic tile and preparation method thereof |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998005601A1 (en) | 1996-08-07 | 1998-02-12 | Italcementi S.P.A. | Hydraulic binder and cement compositions containing photocatalyst particles |
| EP0633064B1 (en) | 1993-06-28 | 1998-12-23 | Ishihara Sangyo Kaisha, Ltd. | Photocatalyst composite and process for producing the same |
| US6013372A (en) * | 1995-03-20 | 2000-01-11 | Toto, Ltd. | Method for photocatalytically rendering a surface of a substrate superhydrophilic, a substrate with superhydrophilic photocatalytic surface, and method of making thereof |
| US20040072684A1 (en) * | 1997-12-10 | 2004-04-15 | Kazuya Tsujimichi | Photocatalytic hydrophilifiable material |
| US20060116279A1 (en) | 2003-01-09 | 2006-06-01 | Hisao Kogoi | Composite particles and method for production thereof and use thereof |
| US20100117271A1 (en) * | 2008-07-11 | 2010-05-13 | Sfi Electronics Technology Inc. | Process for producing zinc oxide varistor |
| JP2011178603A (en) * | 2010-03-01 | 2011-09-15 | Ohara Inc | Glass ceramic and production method |
| WO2011113692A1 (en) | 2010-03-19 | 2011-09-22 | Evonik Röhm Gmbh | Coated sheet-like plastic material with reduced tendency to colonization by algae, process for the in-line production thereof and use |
| US20140205546A1 (en) | 2011-06-17 | 2014-07-24 | Annuary Healthcare, Inc. | Nanoscale particle formulations and methods |
| DE202015000762U1 (en) | 2015-02-03 | 2016-05-10 | NADICO Technologie GmbH | Universal faceplate for lamps of all kinds with hygienic and odor neutralizing function |
| RO132438A0 (en) * | 2017-10-09 | 2018-03-30 | Răzvan Cătălin Bucureşteanu | Photocatalytic method for disinfecting internal surfaces and biocidal washable paint composition with photocatalytic properties |
-
2018
- 2018-10-11 RO ROA201800793A patent/RO134047A2/en unknown
-
2019
- 2019-10-11 WO PCT/RO2019/000025 patent/WO2020076177A1/en active Application Filing
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0633064B1 (en) | 1993-06-28 | 1998-12-23 | Ishihara Sangyo Kaisha, Ltd. | Photocatalyst composite and process for producing the same |
| US6013372A (en) * | 1995-03-20 | 2000-01-11 | Toto, Ltd. | Method for photocatalytically rendering a surface of a substrate superhydrophilic, a substrate with superhydrophilic photocatalytic surface, and method of making thereof |
| WO1998005601A1 (en) | 1996-08-07 | 1998-02-12 | Italcementi S.P.A. | Hydraulic binder and cement compositions containing photocatalyst particles |
| US20040072684A1 (en) * | 1997-12-10 | 2004-04-15 | Kazuya Tsujimichi | Photocatalytic hydrophilifiable material |
| US20060116279A1 (en) | 2003-01-09 | 2006-06-01 | Hisao Kogoi | Composite particles and method for production thereof and use thereof |
| US20100117271A1 (en) * | 2008-07-11 | 2010-05-13 | Sfi Electronics Technology Inc. | Process for producing zinc oxide varistor |
| JP2011178603A (en) * | 2010-03-01 | 2011-09-15 | Ohara Inc | Glass ceramic and production method |
| WO2011113692A1 (en) | 2010-03-19 | 2011-09-22 | Evonik Röhm Gmbh | Coated sheet-like plastic material with reduced tendency to colonization by algae, process for the in-line production thereof and use |
| US20140205546A1 (en) | 2011-06-17 | 2014-07-24 | Annuary Healthcare, Inc. | Nanoscale particle formulations and methods |
| DE202015000762U1 (en) | 2015-02-03 | 2016-05-10 | NADICO Technologie GmbH | Universal faceplate for lamps of all kinds with hygienic and odor neutralizing function |
| RO132438A0 (en) * | 2017-10-09 | 2018-03-30 | Răzvan Cătălin Bucureşteanu | Photocatalytic method for disinfecting internal surfaces and biocidal washable paint composition with photocatalytic properties |
Non-Patent Citations (10)
| Title |
|---|
| ALIJANI MAHNAZ ET AL: "Effect of Ni Doping on the Structural and Optical Properties of TiO2 Nanoparticles at Various Concentration and Temperature", SILICON, SPRINGER, DORDRECHT, vol. 10, no. 6, 2 May 2018 (2018-05-02), pages 2569 - 2575, XP036641652, ISSN: 1876-990X, [retrieved on 20180502], DOI: 10.1007/S12633-018-9792-5 * |
| BARMEH ALIREZA ET AL: "Wetting and photocatalytic properties of Ni-doped TiO2 coating on glazed ceramic tiles under visible light", THIN SOLID FILMS, ELSEVIER, AMSTERDAM, NL, vol. 666, 12 September 2018 (2018-09-12), pages 137 - 142, XP085505111, ISSN: 0040-6090, DOI: 10.1016/J.TSF.2018.09.007 * |
| CASASOLA R ET AL: "Glass-ceramic glazes for ceramic tiles: a review", JOURNAL OF MATERIALS SCIENCE, KLUWER ACADEMIC PUBLISHERS, BO, vol. 47, no. 2, 4 October 2011 (2011-10-04), pages 553 - 582, XP019990578, ISSN: 1573-4803, DOI: 10.1007/S10853-011-5981-Y * |
| FAGAN, R. ET AL.: "A review of solar and visible light active Ti0 photocatalysis for treating bacteria, cyanotoxins and contaminants of emerging concern", MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING, vol. 42, 2015, pages 2 - 14, XP029342777, DOI: 10.1016/j.mssp.2015.07.052 |
| QIAN ZHANG ET AL: "Improvement of mechanical properties, microscopic structures, and antibacterial activity by Ag/ZnO nanocomposite powder for glaze-decorated ceramic", JOURNAL OF ADVANCED CERAMICS, vol. 6, no. 3, 29 September 2017 (2017-09-29), pages 269 - 278, XP055672886, ISSN: 2226-4108, DOI: 10.1007/s40145-017-0239-z * |
| SEERY ET AL: "Silver doped titanium dioxide nanomaterials for enhanced visible light photocatalysis", JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY, A: CHEMISTRY, ELSEVIER SEQUOIA, LAUSANNE, CH, vol. 189, no. 2-3, 24 May 2007 (2007-05-24), pages 258 - 263, XP022094884, ISSN: 1010-6030, DOI: 10.1016/J.JPHOTOCHEM.2007.02.010 * |
| T. MATSUNAGAR. TOMODAT NAKAJIMAN. NAKARNURAT. KOMINE, F-Q1 APPL. ENVIRON. MICROBIOL., vol. 54, 1988, pages 1330 |
| T. P. T. CUSHNIEP. K. J. ROBERTSONS. OFFICERP. M POLLARDR. PRABHUC. MCCULLAGHJ. M. C.ROBERTSON: "Photobactericidal effects of Ti02 thin films at low temperatures - A preliminary study", J. PHOTOCH. PHOTOBIO. A, vol. 216, 2010, pages 290 - 294, XP027517391, DOI: 10.1016/j.jphotochem.2010.06.027 |
| U. JOOSTK. JUGANSONM. VISNAPUUM. MORTIMERA. KAHRUE. NÓMMISTEU. JOOSTV. KISANDA. IVASK: "Photocatalytic antibacterial activity of nano-Ti02 (anatase)-based thin films: effects on Escherichia coli cells and fatty acids", JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B: BIOLOGY, 2014 |
| ZHICHAO ZENG ET AL: "Fabrication of a Photocatalytic Ceramic by Doping Si-, P-, and Zr-Modified TiO2 Nanopowders in Glaze", JOURNAL OF THE AMERICAN CERAMIC SOCIETY., vol. 93, no. 10, 16 June 2010 (2010-06-16), US, pages 2948 - 2951, XP055672870, ISSN: 0002-7820, DOI: 10.1111/j.1551-2916.2010.03910.x * |
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| CN112535952A (en) * | 2020-12-23 | 2021-03-23 | 常州北化澳联环保科技有限公司 | Preparation method of ceramic tile for purifying VOCs (volatile organic compounds) |
| CN113860887A (en) * | 2021-10-22 | 2021-12-31 | 新明珠集团股份有限公司 | Ceramic plate and preparation method thereof |
| CN113860887B (en) * | 2021-10-22 | 2022-08-30 | 新明珠集团股份有限公司 | Ceramic plate and preparation method thereof |
| CN114516763A (en) * | 2022-03-07 | 2022-05-20 | 安徽鑫民玻璃股份有限公司 | Sintering method of colored ceramic glaze for wine bottle production |
| CN116375449A (en) * | 2023-05-29 | 2023-07-04 | 佛山市和昇昌生物科技有限公司 | Formaldehyde-removing ceramic tile and preparation method thereof |
| CN116375449B (en) * | 2023-05-29 | 2023-08-15 | 佛山市和昇昌生物科技有限公司 | Formaldehyde-removing ceramic tile and preparation method thereof |
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