METHOD FOR PRODUCTION OF MIRROR WITHOUT A COPPER LAYER

Method for production of mirror without a copper layer

1. Technical Field of the Invention

The present invention relates to mirrors and methods of production of such mirrors.

Mirror according to the present invention may have different types of application, for example: mirror for domestic purposes, used, inter alia , in furniture articles, cabinets for clothes or bath rooms; mirror, used in paletkakh for make-up or pudrenitsakh ; mirror, used in automobiles, such as, for example, rear-view mirror for vehicles. The present invention can also be applied for mirrors, used as reflectors sun.

2. Known level of equipment

Mirror for domestic purposes and mirrors for use in solar installations, as a rule, is made so: sheet flat glass (sodium-calcium termopolirovannogo glass) first polished and washed, then is sensitized with the help of chloride solution of tin; after washing surface of glass usually activated by treatment of ammonia solution of silver nitrate, then is applied solution for silver plating for formation of layer of silver; this layer of silver then covered with protective copper layer. After drying is applied one or several layers of lead-containing paint for manufacturing finished mirror. Purpose copper layer is retardation tarnishing layer of silver, and copper layer itself alone is protected from abrasive wear and corrosion paint layer. Can be used different compounds of dye for protection of mirror. However, paint, which provide the best protection of copper layer from corrosion, lead. To Unfortunately, lead is toxic and its application all more and more not encouraged due to protection of health and environment protection.

Company Glaverbel , in particular, have been developed of mirror without traditional used copper layer, allow paint, actually not containing lead, but preserving quality of mirror and acceptable or even improved stability to corrosion and wear. For example, in A SShA№ 6565217 invention describes mirror without a copper layer, which comprises, in the order: glass substrate;

tin and at least one material, selected from palladium, bismuth, chromium, gold, indium, nickel, platinum, rhodium, ruthenium, titanium, vanadium and zinc, applied on surface of glass substrate; layer of silver coating on said substrate surface; at least one material, selected from tin, chromium, vanadium, titanium, iron, indium, copper and aluminium, on surface layer of silver coating, which adjacent to facing at least with one paint layer; and at least one layer of paint, covering layer of silver coating.

In A ep 1113886 in on its side is described method of protecting layer of silver mirror from corrosion by bringing silver layer in contact with the first solution, containing cation, and second solution of, containing anion or hydro ksilnyi ion, at the same time two solution of react with sediment formation on surface layer of silver.

3. Purpose of the invention

One purpose of the present invention, in particular, is simple and effective the method for protection of mirror from corrosion and wear.

The other purpose of the present invention, at least in one of variants its realization, out such method for providing mirror, preserving high mechanical strength.

Additional to the present invention, at least in one of variants its realization, is the simple and effective the method for protection of mirror from corrosion, harmless for the environment.

Additional to the present invention, at least in one of variants its realization, is the mirror without a copper layer.

The other purpose of the present invention is the provision of simple and effective the method for protection of mirror from corrosion, allowing to avoid coating of said layer of lead-containing paint.

4. The essence of the of the present invention

The present invention relates to a method for the production of mirror without a copper layer, comprising the following stages:

a) provision of glass substrate,

b) bringing glass substrate in contact with solution for silver-plating with formation of a layer of silver on the substrate,

c) execution of the sequence of stages, mainly, ciphering:

i. bringing silver layer in contact with at least one passivation solution of, containing ions of bismuth,

ii. application of at least one layer of paint on layer of silver,

iii. optionally washing and/or dried between stages.

Authors invention demonstrated, that mirror, obtained according to the present invention, protected from corrosion and wear by treatment of layer of silver ions or salts of bismuth. This effect, possibly, is achieved presence of accumulation of atoms of bismuth on the surface of the layer of silver.

According to one particular version of the present invention layer of silver is brought in contact with one passivation solution of, containing bismuth ions and ions of tin. It is advantage with practical and economic point of view, since it is necessary to have art with one solution and since is required only one plastic, which reduces production costs and costs of maintenance.

According to another a specific version of the present invention, alternative previous, layer of silver is brought in contact with two passivating solutions, first of which contains ions bismuth, and the second contains ions of tin. In this specific version of realisation of the layer of silver at will, or first treated with solution, containing ions of tin, and then treated with solution, containing ions of bismuth, or first treated with solution, containing ions of bismuth, and then treated with solution, containing ions of tin. In both cases stage washing can take place between treatment solution, containing ions of bismuth, and treatment of solution of, containing ions of tin. Layer of silver may also be treated with simultaneously by both passivating solutions.

More addition, authors-noticed, that combination of passivating by means of bismuth ions and of passivating by means of ions of tin results diffusion nnuyu protection from corrosion and wear of mirrors, made by such method, compared with mirrors, made by traditional by. This effect, possibly, is achieved presence of accumulation of atoms of bismuth and tin on surface of layer of silver.

Authors-noticed, that atoms of bismuth or tin are present on surface layer of silver in the form of insulated sections, otherwise speaking, they do not form separate solid layer on surface of the layer of silver. Their presence can be detected through, for example, with the help of RFS.

Preferably, inhibitive solution, containing tin, is that obtained. After obtaining solution of salt of tin, noticed, through some time, for example, through 48 hours at room temperature, with solution may occur certain reaction, doing its slightly opalestsentnym.

In one preferable version, passivating solution contains as source of bismuth ions bismuth salt (III) in aqueous solution and, in particular, VYuz in acid aqueous solution. So, solutions of salts of bismuth, such as solutions of ΒφΝΟ3) 3, bi/ CeHsO -) or preferably BiCh can be used very simple and economical. Such solutions can be used in such a way with application of (by spraying) amount of salts or bismuth ions (III) in solution of approximately from 0.1 to 240 mg per square meter glass substrate, coated with a layer of silver. Preferably, amount of approximately from 0.1 to 155 mg/m^{2 and}, still more preferably, amount of approximately from 1 to 120 mg/m^{2 is applied on} glass substrate, coated with a layer of silver. So, amount of 0.001 to 0.2 mg bi, preferably from 0.001 to 0.1 mg bi, per metre square glass substrate, coated with a layer of silver, may be in full least sufficient for effective passivation of silvered glass substrate.

Preferably, ph passivating solution of, containing bismuth ions, is from 0.5 to 4.0, preferably from 1.0 to 3.0. At ph below 0.5 layer of silver can be subjected to irreversible acid corrosion of, and at ph above 4.0 amount of salts or bismuth ions (III) in solution may be insufficient, which results in production of bismuth in the passivating solution, preferably, in the form of the sediment. This preferred range of ph, thereby, allows creation of active and effective solutions for stages of passivating layer of silver.

More addition, passiviruyushchie solutions, containing salts or ions of tin (II), may be used very simple and economical. Application of (spraying) number to 1 mg tin in solution per metre square glass substrate, coated with a layer of silver, quite sufficiently for providing protection, and is considered, that application of amounts of more than 1500 mg/m^{2 not} provides uniform increase resistance to corrosion. Actually, use of large amounts of may have negative result, due to Your condensate adhesion between a layer of silver and paint, which inflicted further. Better results obtained in applying on coated with substrate amounts of salts or ions of tin (II) in solution approximately from 0.2 mg to 10 mg per metre square glass substrate, coated with a layer of silver. Preferably, inhibitive solution, containing ions of tin, is chloride solution of tin (SnCb) or sulfate of tin (S11SO4). More preferably, inhibitive solution, containing ions of tin, is solution of SnCb.

Preferably, ph passivating solution of, containing ions of tin, is from 0.5 to 4.0, preferably from 1.0 to 3.0.

In case of, if layer of silver is treated one passivation solution of, which contains bismuth ions and ions of tin, the concentration of these ions, preferably, are, relative to the same, as indicated above. Preferably, ph said solution is from 0.5 to 4.0, preferably, from 1.0 to 3.0.

In other variants of embodiment of the present invention one or several other compounds may be applied during stages of passivating in combination with ions of bismuth or in combination with ions of bismuth and tin on layer of silver, applied on the surface of a glass substrate. Such compounds may be selected from the group, consisting of chromium, vanadium, titanium, iron, indium, copper, aluminum, palladium, nickel, europium, platinum, ruthenium, of sodium, of zirconium, yttrium, rhodium, zinc and cerium.

Mirror according to the present invention, preferably, are characterized by high resistance to wear and resistance to corrosion, preferably, at least comparable with resistance to wear and resistance to corrosion of mirrors, as described in A SShA№ 6565217. Besides, such mirrors may have more low sensitivity to factors, which can lead to encumbering on mirror corrosion yazvam , and/or more low probability of, and/or more low risk their occurrence of..

Layer of silver in mirror, prepared according to the present invention, not coated with copper layer, as occurs in traditional production methods of mirrors. It is advantage with economic and ecological point of view, because is excluded traditional stage coating copper, thereby, saving on materials, production of copper and on the time of repeated treatment. Extremely surprisingly, that bringing layer of silver in contact with solution for processing according to the present invention with subsequent application of paint can to protect layer of silver from corrosion and abrasive wear, exactly as and traditional copper layer, which is covered by paint, containing dye based on lead.

According to the present invention layer of silver is coated with at least one protective layer of paint, so, forming mirror, operating on lumen. So, mirror is provided protection from corrosion and abrasive wear via treatment according to the present invention and layer (s) of paint. Preferably, such layer of paint is applied on layer of silver after, as the latter processed with the help of silane. Bringing layer of silver in contact with silane prior to application of paint can enable adhesion of paint to treated metal coating, which can provide stability of mirror to abrasive wear and corrosion. Preferably, proceeding from ecological reasons, said paint "has no practically lead" or "contains no lead". Traditional, layers of silver mirrors were are protected copper layer. Then copper layer was protected from abrasive wear and corrosion layer of lead-containing paint. Relative content of lead in such layer of paint can reach amounts of approximately 13000 mg/m^2. Mirror according to the present invention not only do not require use of copper layer, but allow paint, which "practically not contain lead" or "lead". It is advantage, since lead is toxic, and fact addition, that it is possible without it, has ecological advantages. Expression "has no practically lead" means, that the relative content of lead in glory considerably below, than relative content of lead, traditional contained in lead-containing paints, usually used for mirrors. Relative content of lead in the layer of paint, which "has no practically lead", as defined, is less than 500 mg/m^2, preferably, less than 400 mg/m^2, more preferably, less than 300 mg/m^2. Expression "contains no lead" means, that relative lead content in paint is less than 10 mg/m^2, preferably, less than 5 mg/m^2. The present invention involves advantage use of paint, which "contains no lead", at the same time, guaranteeing high resistance to wear and resistance to corrosion, preferably, at least comparable with resistance to wear and resistance to corrosion of mirrors, described in A SShA№ 6565217. It also may involve steps of advantage use of paint Your nnoi density of, which "has no practically lead", yet shows high resistance to wear and resistance to corrosion, preferably, at least comparable with resistance to wear and resistance to corrosion, as described in A SShA№ 6565217.

Inhibitive solution can also contain an additive, such as β-naphthol, which has effect diffusion condensate stability of ions in solution, in particular, ions of tin (II).

Authors-found, that efficiency of treatment according to the present invention is provided, if, preferably, solution for treatment of has ph not more than 4. Acidification solution for treatment of is achieved suitably by means of addition of acid, related to bismuth salts, in solution, containing salts of bismuth, or solution, containing mixture of salts of bismuth and tin.

Preferably, one or several compounds may be applied during stages of activation of on the surface of a glass substrate, on which should be applied layer of silver; it may enable resistance mirror to corrosion. Such compounds may be selected from the group, consisting of palladium, bismuth, chromium, gold, indium, nickel, platinum, rhodium, ruthenium, titanium, vanadium and zinc. Release preference palladium amount.

During stages of sensitization of tin, preferably, is applied on the surface of a glass substrate, on which should be applied layer of silver; it may sensibiliize glass substrate and enable adhesion of layer of silver.

Preferably, compound, applied on the surface of a glass substrate during stages of activation of and/or sensitization of, is applied in the form of insulated sections, other words they do not form separate solid layer, for example, palladium, and connection represents insulated section on glass surface.

Production of mirrors according to certain aspects of the present invention stages of sensitization of and activation of can enable resistance to wear and/or resistance to corrosion of mirrors and/or to their dolgovechno sti. According to one particular version of the present invention stage of activation is performed before stage sensitization of or stages of activation and sensitization of is performed simultaneously. Preferably, stage of sensitization is performed before stage of activation of, and stage of activation of before stage silver-plating.

Preferably, solutions, given in contact with glass substrate in successive (sensitizing, activation, serebrenie , passivated, treatment of silane) industrial stages, sprayed on glass substrate, optionally with stages of washing and/or drying.

For example, during industrial production of flat mirrors sheets of the glass pass through successive sections, on which is sprayed solution for sensitizing, solution for activating and substances for silver-plating. In practice, on production line mirrors sheets of the glass, as a rule, pass from one section into the other through conveyor. First their polished and washed before sensitisation of, for example, using chloride solution of tin, sprayed on glass; then washed again. Then solution for activation of sprayed on sheets of the glass, this solution for activating can be, for example, acid aqueous solution Rs1S. Then sheets of the glass are fed in section for rinsing, in which is sprayed demineralized water, after that enter section for silver-plating, in which is sprayed traditional solution for silver-plating, the solution for silver plating is combination of, immediately before applying on glass, two solution of, one solution contains silver salt and that recovers agent or base, and the other solution contains any that recovers agent or base, missing in solution, containing silver salt. Rate of flow and concentration of solution for silver plating, sprayed on glass, is controlled for creating layer of silver, containing from 650 to 1500 mg/m^{2 silver}, preferably, in the range of 700-1200 mg/m^{2 silver}, and, more preferably, in the range of 700-1000 mg/m^{2 of silver}. Then glass is washed, and immediately after washing of layer of silver is sprayed first oxidized inhibitive solution, only that obtained, for example, chloride of tin, on silver-plated sheets of the glass (SnCb) during their moving through the conveyor. After washing of demineralized water then is sprayed the second passivating solution on layer of silver, this inhibitive solution according to the present invention is acid aqueous solution, containing ions of bismuth, obtained, for example, from of bismuth chloride (VYuz). Preferably, nitride-passivated layer of silver then treated with solution, containing silane, and in this specific case layer of silver necessarily washed between stages of passivating and treatment of silane. After treatment with solution, containing silane, rinsing and drying, mirror is coated with at least one paint layer. Then paint is heated (cross sutured) or dried, for example, in drying furnace.

So, mirror according to the present invention, preferably, have acceptable or even improved resistance to wear and/or corrosion; this is determined, in particular, by means of dough CASS and/or method of salt fog, also called by neutral salt fog.

One refractive resistance to wear mirrors with a layer of silver may be its subjecting test, involving spraying of copper salt and acetic acid, known called test CASS , at which the mirror is placed in a test chamber at 50° with and exposed to fog, obtained by spraying aqueous solution, containing 50 g/l of sodium chloride, 0.2 g/l anhydrous copper chloride with sufficient amount of glacial acetic acid, to provide ph sprayed solution to values from 3.0 to 3.1. Detailed description, the shackle contacts the given test, there in international standard iso 9227. Mirrors can be expose to test CASS of different duration, consequently, reflecting properties of artificially sostarennogo mirror can be compare with reflecting properties only that made of mirror. According to standard en 1036-1 exposure time of 120 hours allows to produce index of, relating to resistance mirror to wear. Test CASS is performed on square mirrors with sides 10 cm, and after 120-hour action of acetic acid and fog copper salt each mirror is subjected to microscopic investigation. Main visible proof corrosion is darkening layer of silver and separation of paint on edges of mirror. Level of corrosion is marked on five uniformly distributed points on two opposite edges of square and is calculated average value of these ten measurements. It is also possible measure maximum value of corrosion, present at the edge of square, for producing result, which itself alone is measured in mcm.

Second refractive resistance to wear mirror with metal film may be its subjecting "method salt fog", which consists in the fact, that mirror is kept in chamber at maintaining 35° with saline fog, obtained by spraying aqueous solution, containing 50 g/l of sodium chloride. According to standard en 1036-1 time holding method of salt fog 480 hours allows to produce index of, relating to resistance mirror to wear. Mirror again is subjected to microscopic investigation, and corrosion, available on edge square, is measured for producing result in mcm, so same as and in dough CASS.

The present invention also propagates to use bismuth ions for of passivating layer of silver, applied on glass substrate during production process of mirror without a copper layer. According to this use of bismuth ions are from aqueous solution BiCb. According to one particular use of the present invention bismuth ions is applied in the combination with ions of tin.

Advantages of the owing to this application are such same, as obtained for the method of production of mirror according to the present invention, at the same time they not invention describes more are.

Preferred embodiments embodiment of the present invention will be further described only by means of examples.

Example 1 according to the present invention and comparative is an example of 1

Mirror according to the present invention is performed on traditional of production line of mirrors. Sheets of the glass, consequently, pass from one section of treatment to the other section with the aid of of conveyor. Sheets of the glass polished and is sensitized chloride solution of tin (SnCb) by traditional method. After washing of sheets, consequently, is activated solution of palladium chloride (PdCF). Then sheets of the glass is washed by evaporation of demineralized water. Then is sprayed traditional solution for silver plating, containing silver salt and that recovers agent, on sheets, also rate of flow of spraying is such, that on each sheet is formed layer, containing approximately 750-850 mg/m^{2 of silver}. Then poserebrennoe glass is washed. Oxidized aqueous passivating solution is evaporated over sheet of glass for spraying on it 106 mg/m^{2 SnCF} for addition, to apply 0.8 mg SnCF /m^{2 on the glass substrate}, coated with a layer of silver. Used chloride solution of tin is that obtained. ph sprayed solution is approximately 2.5. After such treatment glass washed and treated with oxidised aqueous passivation solution of, containing BiCF , for spraying 232 mg/m^{2 BiCF} on sheet glass for addition, to applied amount of bi 0.08 mg/m^{2 on the glass substrate}, coated with a layer of silver. ph sprayed solution is approximately 1.5. Then glass is washed, dried and coated with two layers of paints, which are practically not contain lead. So, is applied first layer of paint LLE (sold Fenzi) and second layer of paint AW (sold Fenzi), both layer have density approximately 25 mcm.

Comparative is an example of is performed, as described above, except for failure stages spraying of passivating solution of, containing bismuth ions (BiCF). Comparative is an example of 1 corresponds to mirror, not containing copper, from known level of technology.

Mirror, made by such method, is exposed to an accelerated test on aging, test CASS. Results of tests of mirrors from example 1 and comparative example 1 are presented in table 1. As shown in table 1, mirror, obtained according to the present invention, has dough CASS below, than obtained for comparative example 1. So, passivated layer of silver solution of, containing bismuth ions, improves resistance to corrosion compared with mirror from known level of technology.

Mirror according to example 2 is manufactured in the same way, as described in example 1, except for stages of passivating layer of silver. In particular, layer of silver is treated one passivation solution of, containing bismuth ions and ions of tin. So, oxidized aqueous passivating solution at ph approximately 2.5 is evaporated over sheet of glass for spraying on glass sheet 103 mg/m^{2 BiCh} and 106 mg/m^{2 SnCb} for addition, to applied amount of bi 0.01 mg/m^{2 and number} of sn 1 mg/m^{2 on the glass substrate}, coated with a layer of silver. Then glass is washed, dried and coated with two layers of paints, which are practically not contain lead. So, is applied first layer of paint LLE (sold Fenzi) and second layer of paint AW (sold Fenzi), both layer have density approximately 25 mcm.

Mirror, made by such method, is exposed to an accelerated test on aging, test CASS. Results of tests of mirrors from example 2 and comparative example 1 are presented in table 2. As shown in table 2, mirror, obtained according to the present invention, has dough CASS below, than obtained from comparative example 1. So, passivated layer of silver solution of, containing as bismuth ions, and ions of tin, well as improves resistance to corrosion compared with mirror from known level of technology.

Examples 3-5 according to the present invention and comparative is an example of 2

Mirror according to examples 3-5 is manufactured in the same way, as described in examples 1 and 2, except for stages of passivating layer of silver and type of paint, used for coating layer of silver.

Example 3 according to the present invention glass sheet, coated with a layer of silver, first with oxidised aqueous passivation solution of, containing tin chloride. So, aqueous passivating solution is evaporated over sheet of glass for spraying on it 106 mg/m^{2 SnCb}. Used chloride solution of tin is that obtained. ph sprayed solution is approximately 2.5. After such treatment glass washed and treated with oxidised aqueous passivation solution of, containing BiCh , for spraying 68 mg/m^{2 BiCh}. ph sprayed solution is approximately 3. Then glass is washed, dried and is coated with a layer of paint, not containing lead, with density of approximately 47 mcm.

Comparative is an example of 2: mirror is fabricated as described above, except addition, are passed stage spraying of passivating solution of, containing bismuth ions (BiCh). Comparative is an example of 2 corresponds to mirror, not containing copper, from known level of technology.

Example 4 according to the present invention glass sheet, coated with a layer of silver, first with oxidised aqueous passivation solution of, containing tin chloride. So, aqueous passivating solution is evaporated over sheet of glass for spraying on it 106 mg/m^{2 SnCh}. Used chloride solution of tin is that obtained. ph sprayed solution is approximately 2.5. After such treatment glass washed and treated with oxidised aqueous passivation solution of, containing VYuz , for spraying 108 mg/m^{2 VYuz} on layer of silver. ph sprayed solution is approximately 2.

Example 5 according to the present invention is carried out by means of spraying of one passivating solution of, containing bismuth ions and ions of tin, on layer of silver. So, oxidized water inhibitive solution, at ph approximately 2.5, containing tin chloride (SnCb) and chloride bismuth (VYuz), evaporated above glass sheet for spraying on it 68 mg/m^{2 SnCb} and 68 mg/m^{2 VYuz}. Then glass is washed, dried and is coated with a layer of paint, not containing lead, with density of approximately 47 mcm.

Mirror, made by such method, is exposed to an accelerated test on aging, test CASS. Results of tests of mirrors from examples of 3-5 and comparative example 2 are presented in table 3. As shown in table 3, mirror, obtained according to the present invention, have value of dough CASS below, than obtained for comparative example 2. So, passivated layer of silver solution of, containing as bismuth ions, and ions of tin, improves resistance to corrosion compared with mirror from known level of technology. More addition, unexpectedly, authors invention demonstrated, that due to presence of bismuth ions on surface layer of silver, if used paint, not containing lead, effect protection of silver layer from corrosion and wear above. In table 3 also shown, that plastic layer of silver one passivation solution of, containing ions of bismuth, and second passivation solution of, containing ions of tin, or one passivation solution of, containing ions of bismuth and tin, considerably improves resistance to corrosion and resistance to wear mirrors, made by such method.