Method of treating glass surface

Abstract

The present invention relates to a method for treating a glass surface, a substrate comprising a glass surface treated with the method according to the invention, and the use of the substrate.

Description

Field of the Invention

[0001] The present invention relates to a method for treating at least one glass surface, preferably the surface of a glass container such as a glass bottle, a substrate treated by the method of the present invention, and its uses. Background Art

[0002] Glass derives its strength and optical properties from a flawless surface, and any surface damage such as scratches or defects present on its surface significantly reduces its (basic) strength, especially its compressive strength. In addition, the internal burst strength (also known as internal pressure resistance) of glass containers such as bottles may be reduced due to surface damage. This poses a serious risk to anyone using such damaged bottles, especially if they contain carbonated beverages, as such bottles may burst. Such scratches and defects are usually caused by the normal handling of glass, for example when using or transporting glass bottles containing beverages. When a transparent and smooth glass surface is usually required, surface damage to the glass - especially when used for decorative purposes - is also an optical defect. Examples of products where consumers generally cannot tolerate surface damage are mirrors, window glass, and decorative glass objects.

[0003] To avoid the occurrence of scratches and loss of strength, the glass is usually surface - treated. This surface treatment protects the glass surface from surface damage. Generally, a tin salt is applied to the glass surface at a temperature of about 500 °C to form a thin tin oxide layer, and then a layer containing a lubricant (also known as a lubricant in the art) such as wax is formed at a significantly lower temperature in order to reduce the wear of the glass surface by processing defects. Tin oxide is necessary for providing sufficient adhesion of the lubricant on the glass surface. Tin salts are usually ecologically problematic and harmful to humans. Therefore, organotin compounds are under regulatory pressure, and monobutyltin trichloride - one of the most commonly used tin compounds for coating glass bottles - will be phased out in Europe (CoRAP list ECHA) for this application. However, tin compounds are still in use because even though various alternatives have been considered, no alternative has achieved the same protective properties, so there is no acceptable alternative.

[0004] Various silanes and siloxanes have been proposed as alternatives to tin salts. These systems mainly use epoxy - and amino - functional silanes and siloxanes.

[0005] AU 715826 B2 (Australian application 199731796) teaches the use of mono - amino silanes and lubricants such as polyolefins on glassware to impart a certain degree of abrasion resistance to the surface.

[0006] US 6,096,394 B1 discloses the use of organopolysiloxanes in the cold - end coating of glassware.

[0007] JP 2004 - 196563 describes the application of a formulation containing a silane and a polymer dispersion. The silane is a monomethylsilyl silane or (triethoxysilylpropyl)tetrasulfide. In the latter case, the odor of the thiosilane is unacceptable for applications on glass bottles, especially for applications containing beverages.

[0008] However, to date, prior art coatings using silanes or compounds derived therefrom lack scratch resistance (i.e., dry scratch resistance and wet scratch resistance), especially wet scratch resistance. In addition, many silane - based systems suffer from poor stability of the treatment solutions containing these compounds, requiring frequent replacement of such treatment solutions. This is environmentally and economically undesirable. Due to these drawbacks, they have not been introduced into industry, especially not into large - scale applications.

[0009] Object of the Invention

[0010] Accordingly, an object of the present invention is to overcome the drawbacks of the prior art. Another object of the present invention is to provide a method that allows the treated glass surface to have a sufficiently high scratch resistance without using ecologically harmful tin compounds.

[0011] Of further interest is that the optical appearance of the treated glass is not impaired, neither by the treatment itself nor by that caused by conventional treatments. In addition, the adhesion of labels attached to the treated glass surface must be acceptable. Summary of the Invention

[0012] These objects are solved by a method for treating at least one glass surface according to the present invention, the method comprising the following method steps:

[0013] a) providing a substrate comprising the at least one glass surface;

[0014] b) treating the at least one glass surface with a silane formulation comprising at least one bis - silyl compound, the bis - silyl compound comprising at least one structural unit according to formula (A)

[0015]

[0016] wherein

[0017] each R a1 is independently selected from hydrogen, alkyl, polyether group, and aryl,

[0018] each R a2 is independently an alkylene diyl,

[0019] R a3 is selected from hydrogen, alkyl, and aryl,

[0020] m is an integer from 0 to 3,

[0021] n is an integer from 0 to 3; and

[0022] c) treating the at least one glass surface with an additive formulation comprising at least one lubricant selected from waxes, fatty acids and fatty acid esters;

[0023] so as to obtain the at least one treated glass surface.

[0024] Advantageously, the silane formulation used in the process according to the invention is very stable and can be used and stored for a sufficiently long time. The invention is ecologically friendly since tin compounds are no longer required.

[0025] The process according to the invention advantageously reduces the number of scratches on at least one glass surface, and thus the (basic) strength and internal pressure resistance loss during the use and handling of the substrate, in particular of hollow containers such as bottles.

[0026] Preferred embodiments for solving the above object are described in the following description, the description of the invention and the dependent claims. DETAILED DESCRIPTION OF THE INVENTION

[0028] Unless otherwise stated, the percentages throughout this specification are percentages by weight (wt%). Yields are given as percentages of the theoretical yield. Unless otherwise stated, the concentrations given in this specification are based on the mass of the entire solution or dispersion.

[0029] The term "alkyl" according to the invention includes branched or unbranched alkyls containing cyclic and / or acyclic structural elements, where the cyclic structural elements of the alkyl naturally require at least three carbon atoms. C1-CX-alkyl in this specification and the claims means an alkyl having from 1 to X carbon atoms (X being an integer). C1-C18-alkyl includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, tert-pentyl, neopentyl, hexyl, heptyl and octyl, hexadecyl and octadecyl, etc. Unless otherwise stated below, the alkyls are generally unsubstituted.

[0030] The term "alkanediyl" is the corresponding group having two free valences (bonding sites). Sometimes, it is referred to as "alkylene" in the art. The residues according to the invention comprise cyclic and / or acyclic structural elements and can be straight-chain and / or branched. C1-C4-alkanediyl includes, for example, methane-1,1-diyl, ethane-1,2-diyl, ethane-1,1-diyl, propane-1,3-diyl, propane-1,2-diyl, propane-1,1-diyl, butane-1,4-diyl, butane-1,3-diyl, butane-1,2-diyl, butane-1,1-diyl, butane-2,3-diyl, etc. Usually, unless stated otherwise below, the alkanediyl is unsubstituted.

[0031] "Alkenyl" is an unsaturated alkyl group containing at least one olefinic (i.e., C═C-double) bond. The details and preferences of the alkyl groups described above apply to alkenyl groups mutatis mutandis.

[0032] The term "aryl" according to the invention refers to a cyclic aromatic hydrocarbon residue, such as phenyl or naphthyl. Unless stated otherwise below, the aryl is usually unsubstituted.

[0033] The term "alkaryl" according to the invention refers to a hydrocarbon group containing at least one aryl group and at least one alkyl group, such as benzyl and p-tolyl. The bonding of such an alkaryl to other moieties can occur via the alkyl or aryl group of the alkaryl. The above details and preferences of the alkyl and aryl groups apply to alkaryl groups with the necessary modifications.

[0034] If more than one residue - which is an atom, group of atoms or entire structural unit - is selected from a given group, then unless stated otherwise below, each residue is selected independently of one another, which means that they can be selected as the same or different members of the group. The bonding sites in some of the chemical formulas herein can be emphasized by a wavy line as is customary in the art.

[0035] Unless technically infeasible or stated otherwise, the embodiments and preferences described for one aspect of the invention apply, with the necessary modifications, to all its other aspects. Repetitions are omitted to improve the conciseness of the description.

[0036] The method of the invention comprises method steps a), b) and c). These method steps are usually carried out in the given order. The method of the invention optionally comprises additional method steps carried out before, after and / or between said method steps. Method steps b) and c) can be carried out simultaneously, for example, the silane formulation and the additive formulation can be sprayed onto the glass surface simultaneously from two different spraying devices. However, it is preferred to carry out the method steps in the given order to achieve the best results.

[0037] In method step a) of the method of the present invention, a substrate comprising at least one glass surface is provided. The form or function of the substrate is not particularly limited, as long as it comprises at least one glass surface. Optionally, the substrate is made entirely of glass. In one embodiment of the present invention, the substrate consists of at least one glass surface.

[0038] The substrate comprising at least one glass surface is preferably a hollow container, more preferably selected from bottles, thermos flasks, ampoules, tubes, cans, vials and flasks. The substrate is optionally made entirely of glass.

[0039] The glass in the context of the present invention is not particularly limited. Glass includes sodium-calcium silicate glass, aluminosilicate glass, borosilicate glass, aluminoborosilicate glass, silica glass, etc., but also includes non-silicate glasses which are not preferred but are included.

[0040] Optionally, the method comprises another method step after method step a) and before method step b):

[0041] a.i) Cleaning the at least one glass surface.

[0042] A variety of methods are available to those skilled in the art, especially aimed at removing dirt and grease therefrom. For example, the at least one glass surface can be chemically cleaned. Chemical cleaning especially includes treating the surface with an (alkaline) aqueous solution containing a suitable surfactant and / or oxidant. Alternatively, the surface can be wiped with a cloth, which optionally contains the aforementioned aqueous solution.

[0043] In method step b) of the method according to the present invention, the at least one glass surface is treated with a silane formulation. The at least one glass surface is treated completely or only one or more parts thereof with the silane formulation. As described above, the silane formulation comprises at least one bis(trimethylsilyl) compound.

[0044] The silane formulation comprises at least one bis(trimethylsilyl) compound, which comprises at least one structural unit according to formula (A) (the compound will hereinafter be referred to as "bis(trimethylsilyl) compound"). Bis(trimethylsilyl) compounds are known in the art and are commercially available or can be prepared by known methods.

[0045] The polyether group is preferably -[CH 2 -CH(R')-O] j -R” group, where R' is selected from hydrogen and methyl, R” is selected from hydrogen, alkyl and aryl, and j is an integer of 1 or 3 - 100, more preferably an integer of 5 - 20.

[0046] R a1 is preferably selected from hydrogen and C1-C4-alkyl. More preferably, R a1 is hydrogen. Ra2 is preferably a C1-C8-alkanediyl, more preferably a C2-C4-alkanediyl, and even more preferably 1,3-propanediyl. R a3 is preferably selected from hydrogen and C1-C4-alkyl. More preferably, R a3 is hydrogen.

[0047] Particularly preferably, R a1 is selected from hydrogen and C1-C4-alkyl (more preferably each R a1 is hydrogen), R a2 is a C2-C4-alkanediyl (each R a2 is more preferably 1,3-propanediyl), R a3 is selected from hydrogen and C1-C4-alkyl (each R a3 is more preferably hydrogen). This particular preferred selection of at least one building block according to formula (A) is referred to as the particular preferred selection A1. Even more preferably, R a1 is hydrogen, R a2 is 1,3-propanediyl, and R a3 is hydrogen. This particular preferred selection of at least one building block according to formula (A) is referred to as the particular preferred selection A2.

[0048] m is preferably selected from 0, 1, and 2. n is preferably selected from 0, 1, and 2. Preferably, at least one of m and n is less than 3.

[0049] Preferably, the disilyl compound comprises (in addition to at least one building block according to formula (A)) at least one building block according to formula (B)

[0050]

[0051] wherein

[0052] each R b1 is independently selected from hydrogen, alkyl, and aryl,

[0053] R b2 is alkyl,

[0054] R b3 is an alkanediyl,

[0055] R b4 is selected from hydrogen, alkyl, aryl, and alkaryl,

[0056] each R b5 is independently an alkanediyl,

[0057] R b6 is selected from hydrogen, alkyl, aryl, and alkaryl,

[0058] R b7 is selected from hydrogen and alkyl,

[0059] b is selected from 0 and 1,

[0060] c is selected from 0, 1, and 2,

[0061] d is selected from 0, 1, and 2,

[0062] with the precondition that the sum of b and c is 0 - 2.

[0063] The additional structural unit according to formula (B) in the bis(trimethylsilyl) compound advantageously further improves the wet scratch resistance of the glass surface treated with the silane formulation (see Examples).

[0064] In the case where the bis(trimethylsilyl) compound contains at least one structural unit according to formula (B), at least one of m and n is less than 3.

[0065] Preferably, R b1 is preferably selected from hydrogen and C1 - C4 - alkyl. More preferably, R b1 is hydrogen.

[0066] R b2 is preferably C1 - C4 - alkyl, and R b2 is more preferably methyl.

[0067] R b3 is preferably C1 - C8 - alkanediyl, more preferably C2 - C4 - alkanediyl, and even more preferably 1,3 - propanediyl.

[0068] R b4 is preferably selected from hydrogen, alkyl, and aryl, more preferably selected from hydrogen and C1 - C4 - alkyl, and R b4 is even more preferably hydrogen.

[0069] Preferably, R b5 is C1 - C8 - alkanediyl, more preferably C2 - C4 - alkanediyl, and even more preferably 1,2 - ethanediyl.

[0070] R b6 is preferably selected from hydrogen, alkyl, and aryl, more preferably selected from hydrogen and C1 - C4 - alkyl, and R b6 is even more preferably hydrogen.

[0071] R b7 is preferably selected from hydrogen, alkyl, and aryl, more preferably selected from hydrogen and C1 - C4 - alkyl, and R b7 is even more preferably hydrogen. Even more preferably, R b4 、R b6 and R b7 are hydrogen.

[0072] b is preferably 0. c is preferably selected from 0 and 1. d is preferably 0.

[0073] A specific preferred embodiment of at least one building block according to formula (B) is a building block according to formula (B1).

[0074]

[0075] where each R b11 is independently selected from hydrogen and C1-C4-alkyl,

[0076] R b13 is a C2-C4-alkanediyl, even more preferably 1,3-propanediyl,

[0077] R b14 is selected from hydrogen and C1-C4-alkyl, R b14 is even more preferably hydrogen,

[0078] R b17 is selected from hydrogen and C1-C4-alkyl, R b17 is even more preferably hydrogen, and

[0079] c’ is selected from 0, 1, and 2. Preferably all R b11 、R b14 and R b17 are hydrogen.

[0080] The building block according to formula (B1) is a preferred alternative to the aforementioned building block according to formula (B). It is preferably used as the sole alternative to the latter, or (less preferably) the two building blocks are used in combination. Preferably, the at least one disilyl compound comprises (or consists of) at least one building block according to formula (A) with the aforementioned specific preferred selection A1 and at least one building block according to formula (B1), since very good results can be obtained. More preferably, the at least one disilyl compound comprises (or consists of) at least one building block according to formula (A) with the aforementioned specific preferred selection A2 and at least one building block according to formula (B1), since the best results can be obtained.

[0081] The total number of building blocks according to formula (A) and building blocks according to formula (B) (if present) in the disilyl compound is preferably in the range of 2 to 1000, more preferably 3 to 500, even more preferably 4 to 100, and even more preferably 5 to 50.

[0082] Preferably, the numerical ratio of the structural unit according to formula (A) and the structural unit according to formula (B) in the bis(trimethylsilyl) compound is in the range of 1 (structural unit according to formula (A)) to 0.1 - 1000 (structural unit according to formula (B)), more preferably 1 to 1 - 250, even more preferably 1 to 1 - 50, even more preferably 1 to 1 - 10, thus resulting in the best wet scratch resistance of such treated glass surfaces over a wide concentration range of the bis(trimethylsilyl) compound present in the silane formulation. The number or ratio of the structural units can be determined by standard means, such as 1 H, 13 C and / or 29 Si-NMR spectroscopy. Other suitable methods are known to those skilled in the art, such as gel permeation chromatography.

[0083] The at least one structural unit according to formula (A) and - if comprised in the bis(trimethylsilyl) compound - and according to formula (B) preferably accounts for at least 50 wt%, more preferably 75 wt%, even more preferably 90 wt% of the bis(trimethylsilyl) compound. The bis(trimethylsilyl) compound most preferably consists of one or more structural units according to formula (A) and optionally one or more structural units according to formula (B).

[0084] Preferably, at least one bis(trimethylsilyl) compound is an oligomer or a polymer, since then an improved crosslink density of the film obtained from the bis(trimethylsilyl) compound can be obtained. The improved crosslink density results in enhanced dry and wet scratch resistance of the treated surface. The oligomers according to the invention contain (in total) 2 to 4 structural units according to formula (A) and (optionally) (B), and the polymers contain (in total) at least 5 structural units according to formula (A) and (optionally) (B). Non-limiting examples of oligomers containing one structural unit according to formula (A) and (B) are described below:

[0085]

[0086] Oligomers and polymers generally contain one or more linear, branched, and cyclic structures (said structures being formed by building units according to formula (A) and / or (B)). If the disilyl compound contains more than one building unit according to formula (A) and optionally present (B), the building units described herein can also be understood as structural repeating units. If at least one disilyl compound is an oligomer or a polymer, the building units contained in at least one disilyl compound, namely the building units according to formula (A) and - if present - (B), can be arranged in various patterns. The patterns formed by the building units can include alternating, block, and / or random patterns. If the disilyl compound contains more than one building unit according to formula (A) and optionally present (B), they are generally bound to each other through a linking oxygen atom between the silicon atoms of the corresponding building units (depicted as O in the chemical formula) y / 2 , where y represents one of (3 - m), (3 - n), (3 - b - c), or (3 - c').

[0087] As conventionally used in the art, R g -SiO (4-g / 2) should be understood that the depicted silicon atom carries 4 - g oxygen atoms (g being an integer from 0 to 4) and g residues R. The oxygen atoms are bound to the silicon atom by single bonds and thus have another substituent, such as the above - mentioned single silicon atom. In the context of the present invention, the other silicon atom is preferably one of the building units according to formula (A) or (B). If g is 3, there is an M unit. If g is 2, there is a D unit. If g is 1, there is a T unit. If g is 0, there is a Q unit. This nomenclature is known to those skilled in the art, for example from Chemie und Technologie der Silicone by W. Noll, Verlag Chemie, Weinheim Bergstr., 1960, page 2 and one or more subsequent pages.

[0088] An alternative representation of the building unit according to formula (A) is:

[0089]

[0090] This alternative representation of the building unit according to formula (A) highlights the bridging function of the oxygen atoms bound to the silicon atom, which were enumerated as "O (3-h / 2) " (where h represents m or n) in the above description. The free valences of these oxygen atoms (shown by bonds with wavy lines) can be satisfied with any suitable ligand, preferably the silicon atoms of other building units according to formula (A) or (B). If the silicon atoms of other building units according to formula (A) and / or (B) satisfy the free valences, the disilyl compound is an oligomer or a polymer.

[0091] Similarly, an alternative representation of the building block according to formula (B) can be depicted as follows:

[0092]

[0093] Exemplary oligomers of the bis-silyl compound composed of three building blocks according to formula (A) are described below. In this depiction, the three building blocks are highlighted by rectangular boxes with dashed lines to further illustrate the concept of the building blocks. The building blocks are connected by bridging oxygen atoms.

[0094]

[0095] As is known in the art, bis-silyl compounds can be prepared by reacting bis-(trialkoxysilylpropyl)amine and optionally one or more amino-functionalized silanes such as AMEO and condensing them. By the condensation of the above silanes, alkoxy cleavage occurs, facilitating the formation of the above siloxane bonds ("Si-O-Si"). These siloxane bonds include the bridging oxygen atoms between the two silicon atoms of each building block.

[0096] Based on the total silane formulation, the amount of at least one bis-silyl compound in the silane formulation is preferably 0.001 - 10 wt%, more preferably 0.01 - 4 wt%, even more preferably 0.05 - 1 wt%, still even more preferably 0.1 - 0.8 wt%. If the silane formulation contains more than one bis-silyl compound, the amount of all bis-silyl compounds is preferably within the above range.

[0097] The silane formulation preferably contains at least one acid. The at least one acid advantageously improves the stability of the silane formulation. The acid is usually a Bronsted acid, which has a sufficiently high pK a value to transfer a proton to another component in the silane formulation. The at least one acid is usually selected from inorganic acids and organic acids. Preferred inorganic acids are selected from nitric acid, hydrochloric acid, methanesulfonic acid, and mixtures thereof.

[0098] Organic acids are preferred, which are preferably selected from monocarboxylic acids and dicarboxylic acids. The acid is preferably unsubstituted. Monocarboxylic acids are more preferably used as the at least one acid because they surprisingly improve the wetting of the glass surface of the substrate and thus improve the beneficial effects of the present invention. Even more preferably, the at least one acid is a monocarboxylic acid having one to four carbon atoms, and the at least one acid is even more preferably selected from acetic acid and formic acid. Formic acid is most preferred in this regard because it is excellent in this regard.

[0099] The amount of at least one acid depends in particular on the number of amines of the disilane compound. Generally, based on the total silane formulation, the amount of at least one acid is 0.00001 - 10 wt%, preferably 0.01 - 1 wt%, more preferably 0.2 - 0.1 wt%.

[0100] The silane formulation preferably contains water. Based on the total silane formulation, the amount of water is preferably 1 - 99.9 wt%, more preferably 5 - 90 wt%, even more preferably 10 - 80 wt%.

[0101] The silane formulation optionally contains at least one organic solvent. Any organic solvent suitable for dissolving or dispersing the components of the silane formulation can be used. The at least one organic solvent is preferably a polar solvent, more preferably an alkanol, even more preferably a C1 - C4 - alkanol. Based on the total silane formulation, one or more optional organic solvents are preferably included in a total amount of 25 wt% or less, more preferably in an amount of 20 wt% or less, even more preferably in an amount of 15 wt% or less, still even more preferably in an amount of 1.0 wt% or less. Ideally, the amount is less than 0.1 wt% as this further improves the ecological impact of the present invention.

[0102] Ideally, the silane formulation is a solution, preferably an aqueous solution, which is advantageous for treating at least one glass surface therewith, especially if the silane formulation is applied by spraying due to avoiding nozzle blockage of the spraying application device. Alternatively, the silane formulation is a dispersion, preferably a microemulsion. In the latter case, the silane formulation contains at least one emulsifier. At least one emulsifier and its amount can be selected based on the general knowledge of those skilled in the art and routine experiments. In this case, the available emulsifiers can be selected from those described for the additive formulation (see below).

[0103] The pH value of the silane formulation is generally 1 - 14. The pH value is preferably 2 - 7, more preferably 3 - 5, resulting in improved stability of the silane formulation.

[0104] The solids content of the silane formulation is preferably 0.01 - 15%, more preferably 0.05 - 10%, even more preferably 0.1 - 1%.

[0105] The viscosity of the silane formulation is preferably 0.1 - 100000 mPas, more preferably 0.5 - 100 mPas, even more preferably 1 - 5 mPas. The silane formulation with a viscosity within the above range can be easily applied, especially by spraying, without the risk of blocking the nozzle of the spraying application device.

[0106] The silane formulation can be prepared by standard and known methods in the art. Exemplarily, the components described above can be mixed in a suitable container using standard means. The at least one bis-silyl compound is known in the art and commercially available. For example, an oligomeric or polymeric bis-silyl compound can be prepared by hydrolysis and condensation of bis-(trialkoxysilylpropyl)amine and optionally one or more amino-functional silanes such as AMEO. The alcohol obtained during the preparation is preferably removed by distillation.

[0107] Preferably, in addition to the at least one bis-silyl compound, the silane formulation further comprises at least one silane-based compound comprising at least one structural unit according to formula (I)

[0108]

[0109] wherein

[0110] each R y1 is independently selected from hydrogen, alkyl, polyether group and aryl,

[0111] R y2 is alkyl,

[0112] R y3 is an alkylene diyl,

[0113] R y4 is selected from hydrogen, alkyl, aryl and alkaryl,

[0114] each R y5 is independently an alkylene diyl,

[0115] R y6 is selected from hydrogen, alkyl, aryl and alkaryl,

[0116] R y7 is selected from hydrogen and alkyl,

[0117] f is selected from 0, 1 and 2,

[0118] g is selected from 0 and 1,

[0119] h is selected from 0, 1 and 2,

[0120] provided that the sum of f and g is preferably 0 - 2.

[0121] The silane-based compound further improves the wet scratch resistance. The silane-based compound is preferably included in the silane formulation, especially if the at least one bis-silyl compound only comprises or consists of structural units according to formula (A). The silane-based compound preferably does not contain any structural units according to formula (A).

[0122] R y1Preferably selected from hydrogen and C1-C4-alkyl.

[0123] R y3 Preferably a C2-C4-alkanediyl.

[0124] R y4 Preferably selected from hydrogen and C1-C4-alkyl.

[0125] R y7 Preferably selected from hydrogen and C1-C4-alkyl.

[0126] g is preferably 0. h is preferably 0.

[0127] In a preferred embodiment of the present invention, R y1 is selected from hydrogen and C1-C4-alkyl;

[0128] R y3 is a C2-C4-alkanediyl;

[0129] R y4 is selected from hydrogen and C1-C4-alkyl;

[0130] R y7 is selected from hydrogen and C1-C4-alkyl;

[0131] g is 0; f is selected from 0, 1 and 2; and h is 0.

[0132] At least one building block according to formula (I) preferably accounts for at least 50% by weight, more preferably 75% by weight, even more preferably 90% by weight of the silane-based compound. The silane-based compound most preferably consists of one or more building blocks according to formula (I). The number or ratio of the building blocks can be determined by standard means, such as 1 H, 13 C and / or 29 Si-NMR spectroscopy. Other suitable methods are known to those skilled in the art, such as gel permeation chromatography.

[0133] In the silane formulation, the amount of the silane-based compound is preferably 0.001-20% by weight, more preferably 0.01-8% by weight, even more preferably 0.05-2% by weight, still even more preferably 0.1-1.6% by weight, based on the total silane formulation.

[0134] The silane-based compound is known in the art and is commercially available. Useful preparation methods are described in particular in US2018 / 127442 A1 (especially paragraphs 11 to 41 and Examples 1, 2 and 3).

[0135] For the same reasons as for the at least one bis-silyl compound, the at least one silane-based compound is preferably an oligomer or a polymer. The details of the building block pattern described for the at least one bis-silyl compound apply, mutatis mutandis, to the at least one silane-based compound.

[0136] The weight ratio of the at least one silane-based compound to the at least one bis-silyl compound - if the aforementioned compounds are present in the silane formulation according to the invention - is preferably from 0.1 to 0.9, more preferably from 0.2 to 0.8, even more preferably from 0.3 to 0.7.

[0137] In one embodiment of the invention, the silane formulation comprises or consists of:

[0138] - at least one bis-silyl compound;

[0139] - at least one acid,

[0140] - water,

[0141] - optionally at least one organic solvent,

[0142] Preferably in the amounts given above. In this embodiment, the preferences outlined above apply, mutatis mutandis.

[0143] In a preferred embodiment of the invention, the silane formulation comprises or consists of:

[0144] - at least one bis-silyl compound;

[0145] - at least one acid,

[0146] - water,

[0147] - at least one silane-based compound,

[0148] - optionally at least one organic solvent,

[0149] Preferably in the amounts given above. In this embodiment, the preferences outlined above apply, mutatis mutandis.

[0150] The temperature of at least one glass surface in process step b) is preferably from 20 to 200 °C, more preferably from 60 to 150 °C, even more preferably from 100 or 110 to 130 °C. Thus, the glass surface does not need to be heated to as high a temperature as in the case of conventional tin compounds. Thus, the process according to the invention saves energy and is more environmentally friendly.

[0151] Optionally, before treating at least one glass surface with the silane formulation, the temperature of the silane formulation is adjusted to 10 - 80 °C, preferably 20 - 30 °C.

[0152] Generally, it is recommended to keep the temperature difference between the additive formulation (or the method step c) and the glass surface within a certain range. For example, a temperature difference of 100 °C or higher between the additive formulation and the glass surface should be avoided. Otherwise, the glass surface may be subject to treatments that cause cracking, etc. The allowable temperature difference depends especially on the type of glass used. This is known to those skilled in the art, and they will select a suitable temperature based on their general knowledge or based on routine experiments.

[0153] In method step c), at least one glass surface is treated with the additive formulation. The additive formulation includes at least one lubricant. Lubricants that can be used for this purpose are known in the art and can be selected based on routine experiments of those skilled in the art. The at least one lubricant is preferably selected from waxes, fatty acids, and fatty acid esters. More preferably, the at least one lubricant is selected from waxes, fatty acids, and fatty acid esters. Even more preferably, the at least one lubricant is a wax. The outlined preferences allow for increased scratch resistance.

[0154] The wax is preferably used as an aqueous dispersion. Generally, any wax that can be dispersed in water can be used in the present invention. The wax is preferably selected from natural waxes and synthetic waxes. Natural waxes include recent waxes such as beeswax, carnauba wax, or candelilla wax, fossil waxes such as montan wax or its derivatives, and petroleum waxes (paraffin wax and microcrystalline wax). Generally, in the case where the additive formulation is a dispersion (such as an emulsion), it preferably contains at least one emulsifier, which can be selected by those skilled in the art in routine experiments or based on their general knowledge (see below).

[0155] Synthetic waxes are preferably selected from Fischer - Tropsch waxes, polyolefin waxes (such as polyethylene wax, polypropylene wax, polyisobutylene wax, and their copolymers), amide waxes (such as N,N’ - distearylethylenediamine), polyethylene glycol waxes, and polypropylene glycol waxes. More preferably, the synthetic wax is a polyolefin wax or its copolymer, even more preferably a polyolefin wax, and still even more preferably polyethylene wax.

[0156] In one embodiment of the present invention, the at least one lubricant is a wax, preferably the at least one lubricant is selected from amide waxes, polyolefin waxes, and copolymers of polyolefin waxes, more preferably the at least one lubricant is a polyolefin wax or its copolymer, even more preferably a polyolefin wax, and still even more preferably polyethylene wax.

[0157] For better dispersibility, non - polar waxes such as petroleum waxes, Fischer - Tropsch waxes, and polyolefin waxes are preferably used in their oxidized form. Such oxidized waxes have been known for a long time.

[0158] For the purposes of the present invention, polyethylene wax (sometimes also referred to in the art as "polyethylene") is particularly preferred. The number-average molecular weight (M n ) of the polyethylene wax used is generally in the range of 400 to 20,000 g / mol (measured by GPC, PLgel column (Agilent), solvent: 1,2,4-trichlorobenzene + 0.015 wt% butylated hydroxytoluene, 160 °C, using polyethylene standards supplied by Agilent). Preferably, M n is 500 - 15,000 g / mol, more preferably 1000 - 8000 g / mol. This range results in improved stability and enhanced scratch resistance of the additive formulation.

[0159] Preferably, the melting point of the polyethylene wax is 50 - 170 °C, preferably 80 - 150 °C, more preferably 100 - 135 °C. The melting point is measured according to DIN51532 (2012). This range results in improved stability and enhanced scratch resistance of the additive formulation.

[0160] There are many methods known to those skilled in the art for preparing polyethylene wax. Various types are commercially available, also in the form of aqueous dispersions. Exemplarily, they can be prepared by thermal degradation and (if appropriate) free radical degradation of higher molecular weight polyethylene, or by polymerization of ethylene (by a free radical mechanism or by a transition metal catalyst).

[0161] The polyethylene wax optionally has a certain degree of branching, which in the case of short-chain branching can also be caused by the use of olefinic comonomers such as propylene, 1-butene or 1-hexene.

[0162] For the preparation of the dispersions suitable for the present invention, partially oxidized polyethylene wax is preferably used as the starting material, which, if desired, can be additionally esterified and / or saponified. Many types of such polyethylene waxes are commercially available. In addition, copolymers containing 50 mol% or more of ethylene and 50 mol% or less of polar monomers can be used, such as ethylene-vinyl acetate copolymer wax or copolymers of ethylene and acrylic acid. Another possible method for preparing dispersible polyethylene is to graft polyethylene in the melt with unsaturated polar monomers such as maleic anhydride. For this purpose, it is usually useful to add a free radical initiator.

[0163] If desired, the polyethylene wax modified in this way can be converted into non-ionic, anionic or cationic dispersions by conventional methods after further modification, usually by adding one or more emulsifiers.

[0164] Many commercially available (partial) fatty acid esters can be used as the at least one lubricant aid, preferably so-called ester waxes. Preferred examples include stearic acid esters or glyceryl tristearate of ethylene glycol, diethylene glycol, polyethylene glycol or 1,4-butanediol, and mixed partial esters of mannitol with stearic acid and palmitic acid.

[0165] Suitable fatty acids as the at least one lubricant aid have the structure R x -COOH, where R x is a C10-C22-alkyl or C10-C22-alkenyl. Preferred examples are oleic acid, stearic acid, palmitic acid and lauric acid.

[0166] Mixtures of lubricant aids can be used in the context of the present invention. For example, waxes and fatty acids or waxes and (partial) fatty acid esters or fatty acids and (partial) fatty acid esters or any combination thereof can be used.

[0167] The additive formulation optionally contains at least one solvent, which is preferably selected from water, organic solvents and mixtures thereof. If desired, the organic solvents described above can be used. More preferably, the at least one solvent is water because of its ecologically benign characteristics.

[0168] Based on the additive formulation, the amount of the at least one lubricant aid in the additive formulation is preferably 0.05-5% by weight, more preferably 0.1-2% by weight. In the case of using more than one lubricant aid in the additive formulation, the total amount of all lubricant aids is preferably within the above range.

[0169] Generally, especially when the additive formulation is a dispersion (such as an emulsion), the additive formulation preferably contains at least one emulsifier (also known as a surfactant or wetting agent in the art). The at least one emulsifier and its amount can be selected based on the general knowledge of those skilled in the art and routine experiments. The at least one emulsifier is preferably contained in the additive formulation in an amount of 0.01-10% by weight, more preferably 0.1 to 2.5% by weight, even more preferably 0.2 to 1.0% by weight, based on the total additive formulation. If more than one emulsifier is included, the total amount of all emulsifiers is preferably within the above range. Preferably, the HLB value of the at least one emulsifier is 8 or higher, more preferably 11 or higher.

[0170] Useful emulsifiers are selected from nonionic, anionic, cationic, amphoteric emulsifiers and mixtures of the foregoing substances. The at least one emulsifier is preferably selected from nonionic, anionic, cationic emulsifiers and mixtures of the foregoing substances, more preferably from nonionic and cationic emulsifiers and mixtures of the foregoing substances.

[0171] Preferred examples of nonionic emulsifiers are represented by formula (E):

[0172]

[0173] wherein

[0174] R E1 is a C8-C22-alkyl;

[0175] R E2 is selected from hydrogen, alkyl, hydroxy and oxyalkyl;

[0176] each E is independently an alkylene group; and

[0177] e is an integer from 1 to 100.

[0178] R E1 is preferably a C10-C18-alkyl, more preferably a C12-C16-alkyl. Preferably, R E1 is a branched alkyl. Most preferably, R E1 is iso-C13-alkyl. R E2 is preferably selected from hydroxy, oxymethyl and methyl. More preferably, R E2 is hydroxy. E is preferably selected from 1,2-ethanediyl, 1,2-propanediyl and 1,3-propanediyl. e is preferably 2-10, preferably 3-7, more preferably 4-6.

[0179] Preferably, the anionic emulsifier is represented by formula (L)

[0180] R L -L (L)

[0181] wherein R L is a C8-C22-alkyl; and

[0182] L is selected from a carboxylic acid group (-CO 2 H), a sulfonic acid group (-SO 3 H) and a phosphonic acid group (-PO 3 H 2 ) or a salt thereof.

[0183] R L is preferably a C10-C18-alkyl, more preferably a C12-C16-alkyl. Preferably, R L is a branched alkyl. L is preferably a sulfonic acid group or a salt thereof.

[0184] The cationic emulsifier is preferably represented by formula (T)

[0185] R T -T (T)

[0186] wherein R T is a C8-C22-alkyl; and

[0187] T is a cationic group, preferably a group, wherein R k is hydrogen or an alkyl group (which is preferred), such as methyl or ethyl. R T is preferably a C10-C18-alkyl group, more preferably a C12-C16-alkyl group.

[0188] Preferably, the additive formulation comprises colloidal silica, based on the total weight of the additive formulation (and, if a dispersion is used, the solids content of the colloidal silica), preferably in an amount of 0.01 to 1% by weight, preferably 0.05 to 0.5% by weight, more preferably 0.1 to 0.25% by weight. The size (d 50 ) of the silica particles is preferably 10-250 nm, more preferably 20-100 nm. The d value can be measured by dynamic light scattering according to ISO 22412:2017-02, preferably using Malvern Panalytical. 50 The colloidal silica can improve the stability of the additive formulation.

[0189] Optionally, the additive formulation comprises an organic polymer selected from polyurethanes, polyesters, polymethacrylates, and mixtures and copolymers of the foregoing substances. Based on the additive formulation, the amount of the organic polymer is preferably 0.01-10% by weight, preferably 0.1-5% by weight, more preferably 0.25-1% by weight. After applying the additive formulation, the organic polymer enhances the adhesion of the label, coating, or ink applied to the surface.

[0190] At least one glass surface is treated with a silane formulation and an additive formulation by conventional methods. Preferably, the treatment of at least one glass surface in method steps b) and c) is independently carried out by spraying, dipping, roll coating, painting, and combinations of the foregoing. Spraying is preferred in both method steps.

[0191] The temperature of at least one glass surface in method step c) is independently preferably 20-200 °C, more preferably 60-150 °C, even more preferably 100 or 110-130 °C.

[0192] Optionally, before treating at least one glass surface with the additive formulation, the temperature of the additive formulation is adjusted to 10-80 °C, preferably 20-30 °C.

[0193] Preferably, the method of the present invention does not use any tin compounds, such as tin salts like n-butyltin trichloride and tin tetrachloride. Thus, the silane formulation preferably does not contain (intentionally added) tin compounds. In addition, the additive formulation also preferably does not contain (intentionally added) tin compounds. This means that the content of tin compounds in the silane formulation and the additive formulation is preferably 0.1% by weight or less, more preferably 0.01% by weight or less, even more preferably 0.001% by weight, and ideally, they are completely free of tin compounds. In particular, the method of the present invention does not use any tin compounds to bind at least one lubricant to at least one glass surface. Omitting tin compounds such as tin salts is environmentally and toxicologically advantageous, as outlined above.

[0194] In another aspect of the present invention, the silane formulation is used as an adhesion promoter for at least one lubricant on the glass surface of a substrate, and the at least one lubricant is preferably selected from waxes, fatty acids, and fatty acid esters, especially in a cold-end coating process.

[0195] In yet another aspect, the present invention also relates to a substrate comprising

[0196] i) at least one glass surface;

[0197] ii) at least one silane-based layer (hereinafter referred to as "layer ii") obtained by treating the at least one glass surface with the silane formulation defined above;

[0198] iii) at least one additive layer (hereinafter referred to as "layer iii") on the silane-based layer, and the additive layer contains at least one lubricant selected from waxes, fatty acids, fatty acid esters and a wetting agent.

[0199] Layer ii) is obtained by treating at least one glass surface with the silane formulation defined above. Layer ii) has proven difficult to characterize. The inventors of the present invention believe that various compounds derived from at least one bis-silyl compound are present in layer ii). Layer iii) is obtained by treating at least one glass surface (after layer ii) is formed thereon) with the additive formulation.

[0200] The substrate optionally includes one or more additional layers located below layers ii) and iii) (i.e., between layer ii) and at least one glass surface), on top of or between layers ii) and iii). Preferably, the optional additional layer is located on top of layer iii). Layers ii) and iii) are preferably arranged directly on one another. Layer ii) is preferably arranged directly on at least one glass surface. Layer ii) is present over the entire glass surface or only on one or more of its parts. Layer iii) is present over the entire surface area of layer ii) or only on one or more of its parts. Optionally, the substrate includes one or more adhesive layers on layer iii). Conventionally used adhesives can be used for this purpose without limitation. A label is optionally located on the optional adhesive layer. The label is typically made of paper or the like and can be printed on the outside.

[0201] Preferably, the substrate is a hollow container, more preferably a hollow container selected from bottles, thermos flasks, ampoules, tubes, cans, vials, and flasks.

[0202] In yet another aspect of the present invention, the substrate according to the present invention, particularly a hollow container as the substrate, is used for storing a fluid or a solid therein, preferably a fluid, more preferably a liquid, and even more preferably a beverage, such as water.

[0203] In yet another aspect, the present invention relates to a kit comprising:

[0204] P1) A pre-silane formulation comprising at least one bis-silyl compound, the bis-silyl compound comprising at least one structural unit according to formula (A)

[0205]

[0206] wherein

[0207] each R a1 is independently selected from hydrogen, alkyl, and aryl,

[0208] each R a2 is independently an alkylene diyl,

[0209] R a3 is selected from hydrogen, alkyl, and aryl,

[0210] m is an integer from 0 to 3,

[0211] n is an integer from 0 to 3; and

[0212] P2) A pre-additive formulation comprising at least one slip agent selected from waxes, fatty acids, and fatty acid esters.

[0213] P1 preferably comprises the at least one bis-silyl compound, the at least one silane-based compound, the at least one acid, and water.

[0214] The pre-silane formulation can be the same as the silane formulation described above. However, preferably, it is more concentrated. Therefore, the amounts of at least one dimethylsilyl compound and at least one optional acid are preferably higher compared to the silane formulation, while the amount of the solvent (if any) - i.e., at least one organic solvent and water - is lower to save transportation costs. For this purpose, the amount of at least one dimethylsilyl compound in the pre-silane formulation is preferably 5 wt% to 25 wt%, more preferably 10 wt% to 20 wt%.

[0215] The amount of at least one acid in the pre-silane formulation is preferably at least 0.1 wt%, more preferably at least 0.15 wt%, and even more preferably at least 0.2 wt%.

[0216] The pre-additive formulation can be the same as the additive formulation described above. However, preferably, the amount of at least one lubricant is higher, while the amount of the solvent (if any) - at least one organic solvent and water - is lower to save transportation costs. The amount of at least one lubricant in the pre-additive formulation is preferably 10 - 50 wt%, preferably 15 - 40 wt%, and more preferably 20 - 30 wt%.

[0217] The pre-silane formulation and the pre-additive formulation can be diluted to the desired concentration before use, for example, with water and / or at least one organic solvent, preferably with water.

[0218] The present invention will now be illustrated by reference to the following non-limiting examples. Detailed Description

[0219] Examples

[0220] Unless otherwise specified below, commercial products are used as described in the technical data sheets available on the filing date of this specification. Unless otherwise stated differently below, the latest version of the standard is used.

[0221] As the glass substrate, an untreated 1-liter soda-lime silicate glass bottle is used in all experiments. As the manual applicator, a spray gun (IPOTOOLS Mini HLVP Spray Gun) is used. The additive formulation in the examples is prepared using a polyethylene dispersion obtained from TotalEnergies and available as Glasskote SC 100E.

[0222] Determination of the dry residue (solid content): The solid content (also referred to as the dry residue) of the formulation is determined as follows: Weigh out 1.000 g of the sample into a small porcelain dish and dry it in an oven at 105 °C until the weight is constant.

[0223] Determination of the amine content

[0224] Weigh 150 - 400 mg of the sample (depending on the amine content) into a 150 ml beaker and dissolve it with 90 ml of acid (concentrated). The resulting solution is titrated with a solution of perchloric acid in acetic acid (c(HClO 4 ) = 0.1 Mol / l, with an effect diagram detection. Determine the factor of the perchloric acid solution using potassium hydrogen phthalate.

[0225] Calculation:

[0226]

[0227] V = mL of perchloric acid

[0228] c = concentration of perchloric acid in mol / l

[0229] f = factor of perchloric acid

[0230] E = amount of sample in g

[0231] Determination of the free alcohol content in the silane formulation:

[0232] Alcohol determination is carried out by gas chromatography (column: RTX200 (60 m), temperature program: 90 °C, 10 minutes - 25 °C / min to 240 °C, detector: FID, injection volume: 1.0 μl, internal standard: 2 - butanol).

[0233] Measure the pH value according to DIN EN ISO 10523 (2012).

[0234] Measure the viscosity according to DIN 53015 (2019).

[0235] Comparative Example 1

[0236] Add 80.0 g of water to the reactor under a nitrogen atmosphere. Add 20.0 g of (3 - aminopropyl)triethoxysilane to it. Stir the reaction mixture at 60 °C for 3 hours until the silane is completely hydrolyzed. The resulting formulation containing silane oligomers forms a transparent colorless liquid and has the following analytical and physical data:

[0237] Solid content: 7.4 wt%

[0238] Free ethanol content: 13 wt%

[0239] Amine content in terms of NH 2 calculated: 1.5 wt%

[0240] Viscosity: 3.0 mPas

[0241] pH: 11.0

[0242] Comparative Example 2

[0243] Instead of water, 80 g of an aqueous solution containing 5.4 g of 85 wt% formic acid was used, and Comparative Example 1 was repeated. The resulting formulation containing the silane oligomer formed a transparent, colorless liquid and had the following analytical and physical data:

[0244] Solid content: 12 wt%

[0245] Free ethanol content: 13 wt%

[0246] Amine content calculated as NH 2 : 1.48 wt%

[0247] Viscosity: 2.9 mPas

[0248] pH: 4.5

[0249] Comparative Example 3

[0250] Instead of the above silane, 20 g of (3-aminopropyl)dimethoxymethylsilane was used, and Comparative Example 1 was repeated. The resulting formulation containing the silane oligomer formed a transparent, colorless liquid and had the following analytical and physical data:

[0251] Solid content: 14.4 wt%

[0252] Free methanol: 7.9 wt%

[0253] Amine content calculated as NH 2 : 1.97 wt%

[0254] Viscosity: 3 mPas

[0255] pH: 11.2

[0256] Preparation Example 1

[0257] Under a nitrogen atmosphere, 80 g of an aqueous solution containing 5.4 g of 85 wt% formic acid (the aqueous solution, aq.) was charged into a reactor. To the solution was added 19.8 g of (3-aminopropyl)triethoxysilane and 0.2 g of bis[3-(triethoxysilyl)propyl]amine. The reaction mixture was stirred at 60 °C for 3 hours until the silane was completely hydrolyzed. The resulting formulation containing the bis-silyl compound formed a transparent, colorless liquid and had the following analytical and physical data:

[0258] Solid content: 12.1 wt%

[0259] Free ethanol content: 13.0%

[0260] Amine content calculated as NH 2 : 1.48%

[0261] Viscosity: 2.9 mPas

[0262] pH: 4.5

[0263] Preparation Example 2

[0264] Repeat Preparation Example 1 using 19.0 g of (3-aminopropyl)triethoxysilane, 1.0 g of bis[3-(triethoxysilyl)propyl]amine, and 80 g of an aqueous solution containing 5.0 g of 85 wt% formic acid (aq.). The resulting formulation containing the bis-silyl compound forms a clear colorless liquid and has the following analytical and physical data:

[0265] Solid content: 12.0 wt%

[0266] Free ethanol content: 13%

[0267] Amine content calculated as NH 2 : 1.44%

[0268] Viscosity: 2.9 mPas

[0269] pH: 4.7

[0270] Preparation Example 3

[0271] Repeat Preparation Example 1 using 18.0 g of (3-aminopropyl)triethoxysilane, 2.0 g of bis[3-(triethoxysilyl)propyl]amine, and 80 g of an aqueous solution containing 5.1 g of 85 wt% formic acid (aq.). The resulting formulation containing the bis-silyl compound forms a clear colorless liquid and has the following analytical and physical data:

[0272] Solid content: 12.3 wt%

[0273] Free ethanol content: 12%

[0274] Amine content calculated as NH 2 : 1.4%

[0275] Viscosity: 3.0 mPas

[0276] pH: 4.4

[0277] Preparation Example 4

[0278] Repeat Preparation Example 1 using 16.0 g of (3-aminopropyl)triethoxysilane, 4.0 g of bis[3-(triethoxysilyl)propyl]amine, and 80 g of an aqueous solution containing 5.1 g of 85 wt% formic acid (aq.). The resulting formulation containing the bis-silyl compound forms a clear colorless liquid and has the following analytical and physical data:

[0279] Solid content: 12.1 wt%

[0280] Free ethanol content: 12%

[0281] Based on NH 2 Amine content: 1.3%

[0282] Viscosity: 3.2 mPas

[0283] pH: 4.2

[0284] Preparation Example 5

[0285] Repeat Preparation Example 1 using 7.5 g of (3-aminopropyl)triethoxysilane and 7.5 g of bis[3-(triethoxysilyl)propyl]amine and 85 g of an aqueous solution containing 3.9 g of 85 wt% formic acid (aq.). The resulting formulation containing the bis-silyl compound forms a clear colorless liquid and has the following analytical and physical data:

[0286] Solid content: 10.7 wt%

[0287] Free ethanol content: 9.4%

[0288] Based on NH 2 Amine content: 0.84%

[0289] Viscosity: 2.8 mPas

[0290] pH: 3.9

[0291] Preparation Example 6 (100% of the structural unit according to formula (A))

[0292] Charge 85 g of an aqueous solution containing 2.0 g of 85 wt% formic acid (aq.) into a reactor under a nitrogen atmosphere. Add 15.0 g of bis[3-(triethoxysilyl)propyl]amine to the solution. Stir the reaction mixture at 60 °C for 3 hours until the silane is completely hydrolyzed. The resulting formulation containing the bis-silyl compound forms a clear colorless liquid and has the following analytical and physical data:

[0293] Solid content: 8.6 wt%

[0294] Free ethanol content: 9.5%

[0295] Based on NH 2 Amine content: 0.6%

[0296] Viscosity: 12.6 mPas

[0297] pH: 4.5

[0298] Application of the silane formulation (corresponding to method step b))

[0299] The product mixtures obtained as described in Preparation Examples 1 - 6 were diluted with deionized water in the ratios given in the table below (hereinafter named "dilution factor"). Thereby, silane formulations were prepared and ready for use.

[0300] Similarly, comparative formulations with silane oligomers were obtained by diluting the product mixtures obtained as Comparative Examples 1 to 3 with deionized water in the ratios given in the table below (hereinafter named "dilution factor").

[0301] The glass substrates were treated by spraying with a manual applicator. For this purpose, the bottle was rotated once while treating the entire surface of the bottle. Before said treatment, the bottle was heated in an oven to the temperatures given in Tables 1 and 2 below. The spraying conditions were:

[0302] Nozzle diameter: 0.5 mm

[0303] Applied pressure: 4 bar

[0304] Spraying distance: 20 cm

[0305] Spraying volume: 20 ml / min

[0306] Rotation duration of about 6 - 7 seconds

[0307] Application of the additive formulation (corresponding to method step c))

[0308] The glass substrates were sprayed with a manual applicator. For this purpose, the bottle was rotated twice while treating the entire surface of the bottle. Before said treatment, the bottle was heated in an oven to the temperature given below. The additive formulation was prepared by diluting Glasskote SC 100E with deionized water to the concentration given below. The spraying conditions were:

[0309] Temperature: 90 °C

[0310] Polyethylene concentration: 0.28 wt%

[0311] Nozzle diameter: 0.8 mm

[0312] Applied pressure: 4 bar

[0313] Spraying distance: 20 cm

[0314] Spraying volume: 20 ml / min

[0315] The rotation durations were each about 10 seconds.

[0316] Test method

[0317] Dry and wet scratch resistance - Scratch test

[0318] The scratch resistance was tested by rubbing the surfaces of two coated glass bottles against each other, one bottle in each hand. The test was repeated several times by at least two individuals in various areas of the glass bottle. The cases of scratch resistance or slip resistance were recorded. The wet scratch resistance was tested in the same way as the dry scratch resistance, but the glass surface was pre-wetted with water. For this purpose, the glass surface was wetted under running water (until wet). The pressure and scratch time (15 s) were kept constant.

[0319] Grading: No scratch: 1, Slight scratch: 2, Scratch on the entire test surface: 3

[0320] Optical appearance

[0321] The optical appearance was visually inspected by at least two individuals. The optical appearance was graded according to the following criteria by turbidity: Clear (1), Slightly turbid (2), and Turbid (3).

[0322] Adhesion of the label

[0323] A paper label using a standard adhesive (Türmerleim ST 50KF, standard casein-based label adhesive) was glued to the treated glass bottle. The paper label was cured at room temperature (20 °C) for 7 days. The label was manually peeled off.

[0324] The grading was as follows: No peeling (fiber tearing) = 1 (good), Partial peeling = 2 (acceptable), and Complete peeling = 3 (unacceptable).

[0325] Table 1: Test results of a silane formulation containing a bis-silyl compound and a comparative formulation containing a silane oligomer.

[0326]

[0327] a Comparative example; b Example according to the invention; * Ratio of parts by weight of the preparation example / comparative example to parts by weight of water (1:40 means, for example, 1 g of the preparation example is diluted with 40 g of water)

[0328] Table 2: Test results of a silane formulation containing a bis-silyl compound and a comparative formulation containing a silane oligomer, with higher concentrations compared to Table 1.

[0329]

[0330] a Comparative example; b Example according to the invention

[0331] The results clearly show that, compared to glass bottles treated by prior art methods, the method according to the invention improves the scratch resistance of the glass surface of the corresponding treatment. In particular, the wet scratch resistance is significantly enhanced.

[0332] Furthermore, in the case of the embodiments of the present invention, the adhesion of the labels is excellent and mostly superior to those of the comparative embodiments (see in particular the results given in Table 2). Equally advantageously, the properties of the bottles are not impaired, such as their optical appearance or their (basic) strength.

[0333] Other embodiments of the invention will be apparent to those skilled in the art from consideration of this specification or practice of the invention disclosed herein. The specification and examples are to be considered only as exemplary, with the true scope of the invention being defined only by the following claims.

Claims

1. A method for treating at least one glass surface, comprising the following method steps: a) providing a substrate comprising the at least one glass surface; b) treating the at least one glass surface with a silane formulation comprising at least one bis(trimethylsilyl) compound, the bis(trimethylsilyl) compound comprising at least one structural unit according to formula (A) where Each R a1 is independently selected from hydrogen, an alkyl group, a polyether group, and an aryl group, Each R a2 independently is an alkylene group, R a3 selected from hydrogen, alkyl and aryl, m is an integer from 0 to 3, n is an integer from 0 to 3; and c) treating the at least one glass surface with an additive formulation comprising at least one lubricant selected from waxes, fatty acids and fatty acid esters; so as to obtain the at least one treated glass surface.

2. The method according to claim 1, characterized in that the bis(trimethylsilyl) compound comprises at least one structural unit according to formula (B) where Each R b1 is independently selected from hydrogen, alkyl, and aryl, R b2 is an alkyl group, R b3 is an alkylene group, R b4 selected from hydrogen, alkyl, aryl and alkaryl, Each R b5 independently is an alkylene group, R b6 selected from hydrogen, alkyl, aryl and alkaryl, R b7 selected from hydrogen and alkyl, b is selected from 0 and 1, c is selected from 0, 1 and 2, d is selected from 0, 1 and 2, with the proviso that the sum of b and c is from 0 to 2.

3. The method according to claim 1 or 2, characterized in that the silane formulation comprises at least one acid.

4. The method according to any one of the preceding claims, characterized in that the silane formulation comprises water.

5. The method according to any one of claims 2 - 4, characterized in that in the bis(trimethylsilyl) compound, the numerical ratio of the at least one structural unit according to formula (A) to the at least one structural unit according to formula (B) is from 1:1 to 250.

6. The method according to any one of the preceding claims, characterized in that the method does not use any tin compounds.

7. The method according to any one of the preceding claims, characterized in that R a1 selected from hydrogen and C1-C4-alkyl, R a2 is a C2-C4-alkanediyl, and R a3 is selected from hydrogen and C1-C4-alkyl.

8. The method according to any one of the preceding claims, characterized in that based on the total silane formulation, the amount of the at least one bis(trimethylsilyl) compound in the silane formulation is from 0.001 to 10% by weight, preferably from 0.01 to 4% by weight, more preferably from 0.05 to 1% by weight, even more preferably from 0.1 to 0.8% by weight.

9. The method according to any one of the preceding claims, characterized in that the at least one lubricant is a wax, preferably the at least one lubricant is selected from amide waxes, polyolefin waxes and copolymers of polyolefin waxes, more preferably the at least one lubricant is a polyolefin wax or its copolymer, even more preferably a polyolefin wax, still even more preferably a polyethylene wax.

10. The method according to any one of the preceding claims, characterized in that the silane formulation comprises at least one silane - based compound, the silane - based compound comprising at least one structural unit according to formula (I) where Each R y1 is independently selected from hydrogen, an alkyl group, a polyether group, and an aryl group, R y2 is an alkyl group, R y3 is an alkylene group, R y4 selected from hydrogen, alkyl, aryl and alkaryl, Each R y5 is independently an alkylene diyl, R y6 selected from hydrogen, alkyl, aryl and alkaryl, R y7 selected from hydrogen and alkyl, f is selected from 0, 1 and 2, g is selected from 0 and 1, h is selected from 0, 1 and 2, with the proviso that the sum of f and g is preferably from 0 to 2.

11. Use of a silane formulation comprising at least one bis(trimethylsilyl) compound as an adhesion promoter for at least one lubricant selected from waxes, fatty acids and fatty acid esters on the glass surface of a substrate, the at least one bis(trimethylsilyl) compound comprising at least one structural unit according to formula (A) where Each R a1 is independently selected from hydrogen, alkyl, and aryl, Each R a2 is independently an alkylene group, R a3 selected from hydrogen, alkyl and aryl, m is an integer from 0 to 3, n is an integer from 0 to 3.

12. A substrate which comprises: i) at least one glass surface; ii) at least one silane-based layer obtained by treating the at least one glass surface with a silane formulation according to any one of claims 1-10; iii) at least one additive layer on the silane-based layer, the additive layer comprising at least one lubricant selected from waxes, fatty acids and fatty acid esters.

13. The substrate according to claim 12, wherein, the substrate is a hollow container, preferably selected from bottles, flasks, ampoules, tubes, cans, vials and flasks.

14. Use of the hollow container according to claim 13 for storing fluids or solids, preferably fluids, more preferably liquids, even more preferably beverages.

15. A kit which comprises: P1) a pre-silane formulation comprising at least one bis-silyl compound, the bis-silyl compound comprising at least one structural unit according to formula (A) wherein Each R a1 is independently selected from hydrogen, alkyl, and aryl, Each R a2 independently is an alkylene group, R a3 selected from hydrogen, alkyl and aryl, m is an integer from 0 to 3, n is an integer from 0 to 3; and P2) a pre-additive formulation comprising at least one lubricant selected from waxes, fatty acids and fatty acid esters.

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