Adhesion promoter for polysulfide and polythioether-based sealants

Abstract

The present invention relates to a method for sealing a substrate, comprising at least steps 1) and 3), i.e., step (1)) of applying a solvent-type composition to at least a portion of the surface of an optionally pre-coated substrate to form a film on at least a portion of the surface; and step (3)) of applying a sealant composition to at least a portion of the film obtained after step 1) to form a sealant film, wherein the sealant composition can be obtained by mixing at least two separately existing sealing system components A) and B) with respect to each other, the solvent-type composition applied in step 1) comprises at least two different alcohols as organic solvents as component a1) in an amount of at least 85.0% by mass of the total mass of the composition, at least one organic metalate as component a2) wherein the metal of the metalate is selected from Ti and Zr, and at least one organic silane as component a3) in an amount of up to 10.0% by mass of the total mass of the composition. The present invention also relates to a sealed substrate that can be obtained by this method, a method for using the solvent-type composition as an adhesion-promoting composition, the solvent-type composition itself, and a kit of parts comprising the solvent-type composition.

Description

Technical Field

[0001] The present invention relates to a method for sealing a substrate optionally pre-coated, the method comprising applying a solvent-based composition as an adhesion promoter to the surface of the substrate and then applying a sealant composition. The present invention also relates to a sealed substrate obtainable by this method, a method of using the solvent-based composition as an adhesion promoter, the solvent-based composition itself, and a kit-of-parts comprising the solvent-based composition.

Background Art

[0002] Sealants are used in a wide variety of applications. For example, although related to the aerospace field, they are also widely used in the automotive field. Further, sealants are used for sealing structural members, for example, to join a metal sheet to an existing structure (such as an aircraft segment), or for corrosion protection of areas where the corrosion protection layer of a metal member, such as around a hole, has been damaged or removed. They may also perform a temporary support function, such as during the transportation of an assembled structure where a permanent support joining member needs to be retrofitted.

[0003] The sealant needs to adhere well to the substrate surface. For this purpose, i.e., to ensure the adhesion between the substrate and the sealant applied to the upper layer, the use of various adhesion promoters corresponding to various substrates is known in the prior art.

[0004] For this purpose, a suitable adhesion promoter can be directly incorporated into the sealant composition that forms the sealant. Alternatively, the adhesion promoter can be applied to the surface of the substrate to be sealed in a separate process before the sealant is applied. This type of adhesion promoter is described in US 2021 / 0402748 A1 and US 2021 / 0187922 A1. US 2021 / 0402748 A1 relates to an adhesion promoter composition for improving the adhesion between adjacent layers of a sulfur-containing sealant, the composition comprising a free radical polymerizable compound such as a functional (meth)acrylate oligomer, a free radical initiator, and a volatile organic solvent. US 2021 / 0187922 A1 discloses a multilayer sealant comprising a first sulfur-containing sealant layer, an adhesion promoter intermediate layer disposed on the first sulfur-containing sealant layer, and a second sulfur-containing sealant layer disposed on the adhesion promoter intermediate layer, wherein the adhesion promoter intermediate layer comprises a crosslinked free radical polymerizable compound.

[0005] Furthermore, other types of such adhesion promoters utilizing compositions containing metal alkoxides are disclosed in US 2021 / 0047488 A1 and US 2021 / 002514 A1. US 2021 / 0047488 A1 relates to a method and composition for preparing a surface containing thermoplastic or thermosetting material, such as a polyamide material, for receiving a polysulfide or polythioether sealant or coating, the method comprising applying an activating composition to the surface, the activating composition comprising a tetraalkoxide and / or a complex of a group quaternary metal alkoxide. US 2021 / 002514 A1 relates to a surface activating composition comprising an organic solvent, a transition metal alkoxide, and optionally water. A sealant layer can be applied on top of the dry layer obtained by applying this composition.

[0006] Silanes, particularly organic silanes, are known to be suitable as adhesion promoters for a variety of substrates. Due to their broad compatibility with many chemical systems, they can be used in a variety of materials, including sealant materials, and can also be used as separate adhesion promoter compositions. Compared to other chemically different adhesion promoters such as phenolic resins or polyolefins, silanes typically do not significantly affect the pH environment within the material in which they are used. This is particularly important in applications where ambient conditions, such as a constant pH environment, are critical to the curing properties of the material, such as in the case of polysulfide and / or polythioether sealants. Examples of silane applications are disclosed, for example, in US 2021 / 0189206 A1 and WO 2020 / 232462 A1. US 2021 / 0189206 A1 includes amine-functional and alkenyl-functional alkoxysilanes for improving adhesion between organic titanates and / or zirconates, organic solvents, and metal substrates and top layer sealants such as radical polymerization sealants (particularly those based on thiolene chemistry), where the alkenyl groups of the alkenyl-functional alkoxysilanes can adhere to the polymer structure of the sealant. The use of silane-based sealers is also described, for example, in WO 2020 / 232462 A1, which relates to a composite structure comprising a thermoplastic substrate and a chemical sealant directly bonded to its surface, the chemical sealant providing a surface suitable for bonding adhesives, paints, and / or surface coating films to the thermoplastic surface.

[0007] However, adhesion promoters known in the prior art, such as those disclosed in US 2021 / 0189206 A1, do not always provide sufficient adhesion to efficiently bond sealants to the surface of substrates to be sealed, particularly in the field of sealants for the aerospace industry, and more specifically in the use of sealant compositions containing polymers having thiol groups, such as polysulfide and / or polythioether-based sealant compositions. In particular, sufficient adhesion is not always obtained when using thermoplastic resins such as polycarbonate or PMMA (polymethyl methacrylate) substrates or glass substrates. Furthermore, the aforementioned adhesion promoters known in the prior art often contain substantial amounts of toxic substances, which is ecological and economically disadvantageous. In addition, the aforementioned adhesion promoters known in the prior art, such as those disclosed in US 2021 / 0189206 A1, require relatively high concentrations of active ingredients, particularly at least two types of silanes present, and are applied at relatively thick dry film thicknesses of several micrometers, which is also ecological and economically disadvantageous.

[0008] Therefore, there is a demand for adhesion-promoting compositions and sealing methods for substrates using the same, particularly for substrates used in the aerospace industry, such as metal substrates that are coated as needed, that do not have the aforementioned drawbacks. In particular, there is a demand for adhesion-promoting compositions that provide excellent adhesion between various different substrates, especially metal substrates, and sealants applied to their surfaces. Here, the sealant can be obtained from a sealant composition comprising polymers having thiol groups, such as polysulfides and / or polythioethers, and the adhesion-promoting composition can further be provided in an ecologically and economically advantageous form, in particular in a non-toxic or at least low-toxicity form with reduced concentrations of active ingredients, allowing for the application of thin dry film thicknesses without impairing its adhesion-promoting properties, especially compared to conventional adhesion promoters. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] US 2021 / 0402748 A1 [Patent Document 2] US 2021 / 0187922 A1 [Patent Document 3] US 2021 / 0047488 A1 [Patent Document 4] US 2021 / 002514 A1 [Patent Document 5] US 2021 / 0189206 A1 [Patent Document 6] WO 2020 / 232462 A1 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] Therefore, the fundamental objective of the present invention is to provide an adhesion-promoting composition and a method for sealing a substrate using such a composition, particularly when the substrate is a substrate used in the aerospace industry, such as a metal substrate that is optionally coated. In particular, the fundamental objective of the present invention is to provide an adhesion-promoting composition that provides excellent adhesion between various different substrates, such as metal substrates, and a sealant applied to its surface. This adhesion-promoting composition is obtained from a sealant composition comprising a polymer having thiol groups, such as a polysulfide and / or polythioether, and can further be provided in an ecologically and economically advantageous form, in particular in a non-toxic or at least low-toxicity form with reduced concentration of active ingredients, allowing for the application of a thin dry film without impairing its adhesion-promoting properties, especially compared to conventional adhesion promoters. [Means for solving the problem]

[0011] This objective is addressed by the subject matter of the claims of this application and its preferred embodiments disclosed herein, i.e., the subject matter described herein.

[0012] The first subject of the present invention is at least steps 1) and 3), and optionally at least one of steps 2) and / or 4), i.e. 1) A step of applying a solvent-type composition to at least a portion of the surface of a substrate that has been optionally pre-coated to form a film on at least a portion of the surface. 2) Optionally, a step of drying and / or curing the film obtained after step 1), 3) A step of forming a sealant film by applying a sealant composition different from the solvent-type composition used in step 1) to at least a portion of the optionally dried and / or cured film obtained after step 1) or 2), The sealant composition can be obtained by mixing at least two separately existing components A) and B) of a sealing system, wherein component A) of the sealing system comprises at least one polymer component A1) containing two or more thiol groups, selected from polyethers, polythioethers, polysulfides, polythioether-sulfide components and mixtures thereof, and component B) of the sealing system comprises at least one component B0) suitable for curing the sealant composition by at least partially inducing the chemical conversion of two or more thiol groups of component A1), 4) Optionally, a step to cure the sealant film obtained after step 3). A method for sealing an optionally pre-coated substrate, including, Here, the solvent-type composition applied in step 1) consists of at least two different components a1) to a3), i.e., As component a1), at least two organic solvents in an amount of at least 85.0% by mass relative to the total mass of the composition, wherein the at least two organic solvents are alcohols and are different from each other, and at least one of the at least two alcohols has exactly one OH group and at least one other alcohol has at least two or more OH groups, At least one organic metalate as component a2), wherein the metal of the metalate is selected from Ti and Zr, at least one organic metalate, and As component a3), at least one organic silane in an amount of up to 10.0% by mass based on the total mass of the composition comprising The sum of all components present in the solvent-based composition is 100% by mass.

[0013] A further subject of the present invention is a sealed substrate obtainable by the method of the present invention, which sealed substrate is preferably suitable for use in the aircraft and / or aerospace industry.

[0014] A further subject of the present invention is a method of using the solvent-based composition defined and used in step 1) of the aforementioned method as an adhesion-promoting composition, in particular to improve the adhesion between the surface of an optionally pre-coated substrate and a subsequently applied sealant film.

[0015] A further subject of the present invention is the solvent-based composition defined in relation to step 1) of the aforementioned method.

[0016] A further subject of the present invention is a kit of parts comprising at least a sealing system comprising at least two components A) and B) separated from each other as defined in relation to step 3) of the method, and the solvent-based composition defined in relation to step 1) of the method or the solvent-based composition of the present invention, separated from each other.

[0017] Particularly surprisingly, the solvent-based compositions described above and below can be used as adhesion promoter compositions, particularly one-component (1K) compositions, and have been found to provide excellent adhesion between various different substrates that can be used in the aircraft and / or aerospace industries, particularly metal substrates, and the sealants applied to their surfaces. These sealants can be obtained from sealant compositions containing polymers having thiol groups, such as polysulfides and / or polythioethers, and can be cured using an epoxy resin particularly when using a polythioether-based sealant composition, and can also be cured using a metal oxide such as manganese dioxide particularly when using a polysulfide-based sealant composition. Therefore, the solvent-based composition can be applied as an adhesion promoter to the surfaces of various substrates before any sealant application, and can be used, for example, in the assembly of aircraft and aerospace windows.

[0018] Furthermore, particularly surprisingly, the solvent-based compositions described above and below have been found to be able to be provided and used in an ecologically and economically advantageous form, particularly a non-toxic form or low toxicity, i.e., at least a form with reduced toxicity, without impairing their adhesion-inducing properties as compared to conventional adhesion promoter compositions. In particular, the solvent-based compositions described above and below have been found to have a flash point above 40 °C, and thus have been found to be completely non-hazardous or very low in hazard particularly as compared to solvent-based compositions of the prior art. The sufficiently high flash point achieved has been found to be due to the presence of component a1) of the solvent-based composition according to the invention.

[0019] Furthermore, particularly surprisingly, the solvent-based compositions described above and below have been found to be able to be provided and used in a form having a lower active ingredient content particularly with respect to components a2) and / or a3) as compared to conventional adhesion promoters known in the prior art. In particular, with respect to at least one organosilane as component a3), it has been particularly found that when the amount of a3) is excessive, particularly when it exceeds 10.0% by mass with respect to the total mass of the composition, poor adhesion occurs after applying the solvent-based composition in step 1).

[0020] Furthermore, surprisingly, the solvent-based compositions described above and below were found to be applicable only to very thin layers, substantially less than 1 μm, such as dry film thicknesses of 300 nm or 200 nm or less. This offers a special advantage in the solvent-based compositions: relatively low active ingredient concentrations can be used, particularly with respect to components a2) and a3), while nevertheless providing excellent cohesive bonding between the substrate and the sealant. [Modes for carrying out the invention]

[0021] In the present invention, the term "contains," for example in relation to adhesion-promoting compositions, preferably means "consisting of." For example, with respect to adhesion-promoting compositions, in addition to all the essential components present, one or more additional optional components described below may also be included. All components may be present in the preferred embodiments specified below in each case.

[0022] The proportions and mass percentages (mass%) of all components present in the adhesion-promoting compositions described herein are, in each case, total 100% by mass based on the total mass of the adhesion-promoting composition. The same applies to other compositions disclosed herein, such as sealant compositions.

[0023] A method for sealing a substrate that has been arbitrarily pre-coated. The first subject of the present invention is a method for sealing an optionally pre-coated substrate, comprising at least steps 1) and 3), and optionally at least one of steps 2) and / or 4). The method may optionally include one or more further steps performed before any of the aforementioned steps, between these steps, and / or after any of the aforementioned steps.

[0024] Any cleaning process Optionally, preferably, the surface of a pre-coated substrate is cleaned before carrying out step 1). Cleaning may be carried out by any conventional technique such as immersion, wiping, brushing, and / or spraying. Preferably, cleaning is carried out using one or more organic solvents applied to the surface of the substrate. A suitable solvent can be selected, for example, according to the recommendations of the substrate manufacturer of the particular substrate used. The cleaning step preferably removes dirt, grease, oil, and / or dust from the surface of the substrate.

[0025] Process 1) In step 1), the solvent-based composition is applied to at least a portion of the surface of an optionally pre-coated substrate to form a film on at least a portion of the surface. Any contact method is generally usable for applying the solvent-based composition in step 1), including immersion, wiping, brushing, and spraying, with wiping and / or brushing being particularly preferred.

[0026] Preferably, the solvent-based composition is applied as an extremely thin layer to the surface of the substrate. Particularly preferably, after performing any step 2), it is applied so that the dry film thickness is less than 1.0 μm, more preferably less than 900 nm or less than 800 nm, even more preferably less than 700 nm or less than 600 nm, even more preferably less than 500 nm or less than 400 nm, and most preferably less than 300 nm or less than 200 nm.

[0027] Preferably, the solvent-based composition is applied in step 1) by wiping using the so-called "wipe-on method." Preferably, in this regard, a brush, a soft lint-free wipe, or a felt-tipped pen is used to apply the solvent-based composition. The solvent-based composition is then wiped onto the surface of the substrate.

[0028] Alternatively, the solvent-based composition is applied in step 1) by wiping using the so-called "wipe-on / wipe-off method." In this case, the solvent-based composition is applied in excess to the surface of the substrate. Preferably, in this regard, a brush, a soft lint-free wipe, or a felt-tipped pen is used to apply the solvent-based composition. The solvent-based composition is then wiped onto the surface of the substrate. Within a few seconds to a few minutes after application, for example, within 5 seconds to 10 minutes, it is preferable to wipe off the excess with a soft lint-free wipe in order to allow the adhesion promoters present in the composition, such as components a2) and / or a3), to undergo hydrolysis reactions, etc.

[0029] Step 1) is preferably carried out at a temperature in the range of 0 to 60°C, more preferably in the range of 5 to 45°C. In particular, no heating is performed.

[0030] Base material In step 1), a pre-coated substrate is optionally used. Suitable substrates include metal substrates, but plastic substrates, such as thermoplastic substrates, fiber-reinforced composites (also referred to herein as fiber-reinforced composites), and glass substrates can also be used. Preferred substrates are those that can be used, for example, as parts and / or processed products in the aerospace and / or aircraft industry. The most preferred substrate is a metal substrate.

[0031] Suitable metal substrates for use in accordance with the present invention are all conventionally used substrates that are well known to those skilled in the art. Preferably, the metal substrates used in accordance with the present invention include substrates composed of steel, steel alloys, aluminum, aluminum alloys, titanium, and / or titanium alloys. The most preferred metal substrates are aluminum and / or aluminum alloy substrates, and steel and / or steel alloy substrates.

[0032] Preferably, when the substrate is a plastic substrate, a thermoplastic resin is used. Suitable thermoplastic polymers include polyalkyl (meth)acrylates, such as polymethyl (meth)acrylate (PMMA), polybutyl (meth)acrylate, polyethylene terephthalate, polybutylene terephthalate, polyvinylidene fluoride, polyvinyl chloride, polyesters, such as polycarbonate (PC) and polyvinyl acetate, polyamides, polyolefins, such as polyethylene, polypropylene, polystyrene, and also polybutadiene, polyacrylonitrile, polyacetal, polyacrylonitrile-ethylene-propylene-diene-styrene copolymer (A-EPDM), ASA (acrylonitrile-styrene v-acrylic acid copolymer) and ABS (acrylonitrile-butadiene-styrene copolymer), polyetherimide, phenolic resins, urea resins, melamine resins, alkyd resins, epoxy resins, polyurethanes, such as TPU, polyether ketones, polyphenylene sulfide, polyethers, polyvinyl alcohol, and mixtures thereof. Polycarbonate and polyalkyl (meth)acrylates, such as polymethyl (meth)acrylate (PMMA), are particularly preferred plastic substrates.

[0033] As mentioned above, fibrous composite materials such as carbon fiber composites are also used as substrates and glass substrates, particularly in windshield applications.

[0034] Preferably, the optionally pre-coated substrate is selected from a metal substrate (wherein the metal is selected from steel, steel alloys, aluminum, aluminum alloys, titanium, titanium alloys, and mixtures thereof) or from a thermoplastic substrate including glass substrates, polycarbonate and polyalkyl(meth)acrylic substrates, and fiber-reinforced composite substrates, in which case the substrate optionally has at least one coating layer.

[0035] Examples of coating layers that already exist on the substrate and thus pre-coat the substrate include primer layers or topcoat layers, which can be obtained from water-based or solvent-based primers or topcoats, such as those based on polyurethane or epoxy resin. If a coating layer is present, it is preferably already cured.

[0036] The base material can have any shape, form, or geometric structure, such as a sheet, foil, or plate.

[0037] Solvent-type composition used in step 1) The solvent-type composition applied in step 1) of the method comprises at least two different components a1) to a3), i.e., As component a1), at least one organic solvent in an amount of at least 85.0% by mass relative to the total mass of the composition, The constituent component a2) is at least one organic metalate, wherein the metal of this metalate is selected from Ti and Zr, and As component a3), at least one organosilane in an amount of 10.0% by mass or less relative to the total mass of the composition. Includes, Here, the total amount of all components present in the solvent-type composition is 100% by mass.

[0038] Preferably, the solvent-based composition is a one-component (1K) composition. The solvent-based composition is suitable as an adhesion promoter, i.e., an adhesion-promoting composition. Preferably, the solvent-based composition is not a sealant composition, and in particular, it is different from the sealant composition applied in step 3).

[0039] The composition used in step 1) is a solventborne, i.e., an organic solvent-based (non-aqueous) composition. In this regard, the term “solventborne” is understood to mean, preferably for the purposes of the present invention, that the organic solvent (as component a1) is present as the main component of all solvents present in the water-containing composition. Any conventional organic solvent known to those skilled in the art can be used as the organic solvent. The term “organic solvent” is well known to those skilled in the art, in particular from Council Directive 1999 / 13 / EC of March 11, 1999.

[0040] The solvent-type composition is preferably water-free, substantially water-free, or may contain a small amount of water. The term "substantially" in this context preferably means that water is not intentionally added during composition preparation. The term "small amount" in this context preferably means that water may be present in an amount of up to 12.5% ​​by mass, up to 10% by mass, or up to 5% by mass, based on the total mass of the composition, especially when it is desirable to achieve a certain level of preliminary hydrolysis of, for example, organosilane components a3) and / or components a2). The presence of water is particularly undesirable when using component a2), which reacts strongly with water to undergo immediate hydrolysis to TiO2 or ZrO2.

[0041] Component a1) of the solvent-type composition Component a1) is at least one organic solvent, present in an amount of at least 85.0% by mass relative to the total mass of the composition. A solvent-type composition may, preferably, contain one or more organic solvents as component a1). Therefore, preferably, a solvent-type composition contains at least two or three organic solvents that are different from each other as component a1). The composition may contain three or more, for example, four different organic solvents. However, preferably, the maximum number of different organic solvents present in the composition is four.

[0042] The solvent-type composition used in step 1) contains, as component a1), at least one organic solvent in an amount ranging from 85.0% to 99.0% by mass, more preferably 85.0% to 98.5% by mass, even more preferably 85.0% to 98.0% by mass, even more preferably 87.5% to 97.5% by mass, even more preferably 90.0% to 97.5% by mass, even more preferably 92.5% to 97.5% by mass, and most preferably 95.0% to 97.0% by mass, based on the total mass of the composition in each case.

[0043] Preferably, especially when the optionally coated substrate used in step 1) is a metal substrate, the solvent-type composition used in step 1) contains at least one organic solvent as component a1) in the range of 87.5% to 99.0% by mass, more preferably 90.0% to 98.0% by mass, even more preferably 92.5% to 97.5% by mass, and even more preferably 94.0% to 97.0% by mass, based on the total mass of the composition in each case.

[0044] Suitable organic solvents for use as component a1) are alcohols, preferably monomeric alcohols, such as alcohols having multiple OH groups, such as diols having two OH groups, and polyols, ethers, esters, ketones, hydrocarbons having more than two OH groups, such as aliphatic, preferably branched hydrocarbons, and mixtures thereof. Examples of alcohols include 1-ethoxypropan-2-ol, 2-methylpentan-2,4-diol, ethanol, isopropanol, and isobutanol. An example of a suitable ketone is 5-methyl-2-hexane-2-one. Examples of suitable esters include ethyl acetate and butyl acetate. An example of aliphatic, preferably branched hydrocarbons is isoalkane. Such aliphatic hydrocarbons are commercially available, for example, Isopar® C, Isopar® E, Isopar® G, and Isopar® H (available from ExxonMobil). The most preferred option is Isopar(registered trademark)G.

[0045] Particularly suitable organic solvents as component a1) of the solvent-type composition used in step 1) are alcohols, ethers, ketones, and mixtures thereof, with alcohol being most preferred when the optionally coated substrate used in step 1) is a metal substrate. Most preferred is a mixture of at least two alcohols, in particular a mixture of at least one alcohol having exactly one OH group, such as 1-ethoxypropane-2-ol, and at least one alcohol having exactly two or more OH groups, such as 2-methylpentane-2,4-diol, where preferably, the at least one alcohol having exactly one OH group is used in excess of the at least one alcohol having two or more OH groups, and more preferably, the relative mass ratio of the at least one alcohol having exactly one OH group to the at least one alcohol having two or more OH groups is in the range of 5:1 to 3:1. Such organic solvents are non-toxic or have low toxicity. Furthermore, the use of such organic solvents is advantageous in terms of a good balance between the flash point (preferably above 40°C) and the evaporation rate of the organic solvent. If the evaporation rate is too slow, delays may occur in the manufacturing process. Preferably, each organic solvent used as component a1) of the solvent-type composition used in step 1) has 3 to 10 carbon atoms, preferably 4 to 8 or 4 to 7 carbon atoms, and optionally has one or more ether functional groups, especially when the optionally coated substrate used in step 1) is a metal substrate. The presence of ether functional groups is particularly advantageous in achieving sufficient solubility of component a2) and / or a3) and / or any component a4) in the solvent-type composition.

[0046] Preferably, the solvent-type composition used in step 1) comprises, as component a1), at least two different organic solvents, preferably, at least one of these at least two organic solvents is an alcohol having one or more OH groups and optionally at least one ether segment, preferably a monomer alcohol having one or more OH groups, preferably a monomer alcohol having exactly one OH group.

[0047] Preferably, the solvent-type composition used in step 1) comprises, as component a1), at least two different organic solvents, i.e., at least two alcohols, each having one or more OH groups, preferably 3 to 10 or 4 to 7 carbon atoms, and preferably monomeric alcohols, where one of the at least two alcohols has exactly one OH group and optionally at least one ether segment, and at least one other alcohol has two or more OH groups, and therefore, if it has two OH groups, it is a diol, and if it has more than two OH groups, it is a polyol, preferably the amount (mass%) of at least one alcohol having exactly one OH group exceeds the amount (mass%) of at least one other alcohol having at least two OH groups, more preferably the relative mass ratio of at least one alcohol having exactly one OH group to at least one alcohol having two or more OH groups is in the range of 5:1 to 3:1, and in particular, if the optionally coated substrate used in step 1) is a metal substrate, at least two alcohols are present in the solvent-type composition.

[0048] a2) Components of the solvent-type composition Component a2) is at least one organic metalate, the metal of which is selected from Ti and Zr. Thus, the metalates correspond to titanate and zirconate.

[0049] Preferably, the solvent-type composition used in step 1) contains component a2) in an amount of at least 0.5% by mass, more preferably at least 0.75% by mass, and even more preferably at least 1.0% by mass. Preferably, the solvent-type composition used in step 1) contains component a2) in an amount of up to 10.0% by mass, more preferably up to 7.5% by mass, and even more preferably up to 5.0% by mass. Preferably, the solvent-type composition used in step 1) contains component a2) in an amount ranging from 0.1% to 15.0% by mass, more preferably 0.25% to 12.0% by mass, even more preferably 0.5% to 10.0% by mass, even more preferably 0.75% to 7.5% by mass, and even more preferably 1.0% to 5.0% by mass, based on the total mass of the composition in each case.

[0050] In particular, if the optionally coated substrate used in step 1) is a metal substrate, the solvent-type composition used in step 1) contains component a2) in an amount ranging from 0.50% to 7.50% by mass, more preferably 0.75% to 5.0% by mass, even more preferably 1.0% to 4.0% by mass, and even more preferably 1.5% to 3.5% by mass, based on the total mass of the composition in each case.

[0051] Preferably, and especially when the optionally coated substrate used in step 1) is a thermoplastic resin, fiber-reinforced composite, or glass substrate, the solvent-type composition used in step 1) contains component a2) in an amount ranging from 0.25% to 7.5% by mass, more preferably 0.5% to 6.5% by mass, even more preferably 0.75% to 6.0% by mass, and even more preferably 1.0% to 5.0% by mass, based on the total mass of the composition in each case.

[0052] Preferably, the organic group of metallate component a2) has 1 to 20 carbon atoms. Preferably, the organic group is bonded to titanium and / or zirconium via a divalent oxygen atom. An example of such an organic group is an acetylacetonate group. Preferably, component a2) is a metal alkoxide, more preferably each alkoxide group represents a -O-C1 to C8 group, more preferably a -O-C3 to C8 group. Examples of alkoxide groups include n-butyl alkoxide, n-propyl alkoxide, and isopropyl alkoxide. The most preferred titanates and / or zirconates are tetra-n-butyl zirconate (trade name Tyzor® NBZ), tetrapropyl titanate (trade name Tyzor® TPT from Dorf Ketal), and titanium acetylacetonate (trade names Tyzor® AA 75, Tyzor® AA 65, and Tyzor® AA 105 from Dorf Ketal).

[0053] Preferably, component a2) is a metal alkoxide, and the metal of the metal alkoxide is selected from Ti and Zr. Preferably, each alkoxide group has 3 to 8 carbon atoms, more preferably 3 to 6, and even more preferably 3 to 4 carbon atoms.

[0054] component a3) of the solvent-type composition Component a3) is at least one organosilane, present in an amount of up to 10.0% by mass based on the total mass of the composition. At least one organosilane may be present in at least a partially hydrolyzed form. If the amount of component a3) exceeds 10.0% by mass, the solvent-type composition used in step 1) may have reduced adhesion-promoting properties and may result in poor adhesion.

[0055] Preferably, the solvent-type composition used in step 1) contains component a3) in an amount of at least 0.5% by mass, more preferably at least 0.75% by mass, and even more preferably at least 1.0% by mass. Preferably, the solvent-type composition used in step 1) contains component a3) in an amount of 9.5% by mass or less, more preferably 7.5% by mass or less, and even more preferably 5.0% by mass or less. Preferably, the solvent-type composition used in step 1) contains component a3) in an amount ranging from 0.1% to 10.0% by mass, more preferably 0.25% to 8.0% by mass, even more preferably 0.5% to 6.0% by mass, even more preferably 0.75% to 5.0% by mass, and even more preferably 1.0% to 5.0% by mass, based on the total mass of the composition in each case.

[0056] In particular, if the optionally coated substrate used in step 1) is a metal substrate, the solvent-type composition used in step 1) contains component a3) in an amount ranging from 0.50% to 7.50% by mass, more preferably 0.75% to 5.0% by mass, even more preferably 1.0% to 4.0% by mass, and even more preferably 1.5% to 3.5% by mass, based on the total mass of the composition in each case.

[0057] Preferably, the molar ratio of at least one component a2) to at least one component a3) in the solvent-type composition is in the range of 1:>1.0 to 1:3.0, more preferably 1:1.2 to 1:2.8, especially when the optionally coated substrate used in step 1) is a metal substrate.

[0058] Various organic silanes can be used as component a3). Organic silanes can be monomers, oligomers, or polymers. In particular, monomer silanes are preferred when the optionally coated substrate used in step 1) is a metal substrate.

[0059] The at least one organosilane used as component a3) preferably comprises (i) at least one hydrolyzable group X and (ii) at least one non-hydrolyzable organic group, the non-hydrolyzable organic group optionally, preferably having or representing at least one functional group. The functional group, e.g., an OH group, may exist in a masked form, for example, by a protecting group that can be removed under hydrolysis conditions. Preferably, a divalent spacer unit is placed between the functional group (e.g., if the functional group represents an amino group) and the non-hydrolyzable organic group so that the functional group does not directly bond to the Si atom. However, if the functional group is, for example, a vinyl group, the functional group may directly bond to the Si atom. Preferably, the functional group is selected from amino groups, epoxy groups, thiol groups, vinyl groups, and (meth)acrylic groups, including primary and secondary amino groups.

[0060] Preferably, the at least one organosilane used as component a3) comprises (i) at least one hydrolyzable group X and (ii) at least one non-hydrolyzable organic group, particularly when the optionally coated substrate used in step 1) is a metal substrate, wherein the non-hydrolyzable organic group has at least one functional group, more preferably at least one amino group.

[0061] Preferably, the at least one organic silane used as component a3) comprises (i) at least one hydrolyzable group X and (ii) at least one non-hydrolyzable organic group, particularly when the optionally coated substrate used in step 1) is a thermoplastic resin, fiber-reinforced composite, or glass substrate, wherein the non-hydrolyzable organic group has or represents at least one functional group, more preferably at least one ethylenically unsaturated group, and even more preferably at least one vinyl group and / or (meth)acrylic group.

[0062] Preferably, the organosilane component a3) contains at least two, preferably at least three, hydrolyzable groups X, where X is preferably an alkoxy group. The hydrolyzable groups X may be identical, or at least two of the groups may be different from each other. Preferably, the hydrolyzable groups X are alkoxy groups, particularly C1-C4 alkoxy groups. Particularly preferred are methoxy groups, ethoxy groups, n-propoxy groups, isopropoxy groups, n-butoxy groups, sec-butoxy groups, and tert-butoxy groups. Most preferred are ethoxy groups and methoxy groups.

[0063] Preferably, at least one organosilane component a3) has a number-average molecular weight in the range of 100 to 2000 g / mol, more preferably 150 to 1800 g / mol, even more preferably 180 to 1500 g / mol, and even more preferably 200 to 650 g / mol.

[0064] The non-hydrolyzable organic group is preferably selected from the group consisting of an aliphatic radical having 1 to 24 carbon atoms, an alicyclic radical having 3 to 12 carbon atoms, an aromatic radical having 6 to 12 carbon atoms, and an aromatic aliphatic radical having 7 to 18 carbon atoms, each of which optionally contains at least one functional group, or is itself the functional group, and the functional group may further optionally be masked with at least one protecting group that can be removed under hydrolysis conditions. Furthermore, each of the aliphatic, alicyclic, aromatic, and aromatic aliphatic radicals may contain one or more heteroatoms and / or heteroatomic groups such as N, O, and / or S.

[0065] Examples of organosilanes having at least one non-hydrolyzable organic group selected from aliphatic radicals having 1 to 24 carbon atoms include methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), methyltripropoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, ethyltriisopropoxysilane, octyltrimethoxysilane, isobutyltriethoxysilane, isobutyltrimethoxysilane, octyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, 1,2-bis(triethoxysilyl)ethane, and 1,2-bis(trimethoxysilyl)ethane. Examples of organosilanes having at least one non-hydrolyzable organic group selected from aromatic radicals having 6 to 12 carbon atoms include phenyltrimethoxysilane (PHS), phenyltriethoxysilane, phenyltrippropoxysilane, and phenyltriisopropoxysilane. Examples of organosilanes having at least one non-hydrolyzable organic group selected from aromatic aliphatic radicals having 7 to 18 carbon atoms include benzyltrimethoxysilane, benzyltriethoxysilane, benzyltrippropoxysilane, and benzyltriisopropoxysilane.

[0066] Organosilanes can contain at least one Si-containing radical, such as exactly one such radical (in the case of monosilanes) or two or more such radicals (in the case of bis or trissilanes), as in the case of 1,2-bis(triethoxysilyl)ethane. Organosilanes having four, five, six or more silyl groups are also possible.

[0067] When the optionally coated substrate used in step 1) is a metal substrate, particularly preferred organic silanes containing at least one primary and / or secondary amino group include, for example, 3-aminopropyltrimethoxysilane (APS), 3-aminopropyltriethoxysilane, 3-aminopropyltriisopropoxysilane, 2-aminoethyltrimethoxysilane, 2-aminoethyltriethoxysilane, 2-aminoethyltriisopropoxysilane, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, aminomethyl Isopropoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane (AEAPS), 3-(2-aminoethyl)aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-(2-aminoethyl)aminopropyltriisopropoxysilane, 2-(2-aminoethyl)aminoethyltrimethoxysilane, 2-(2-aminoethyl)aminoethyltriethoxysilane, 2-(2-aminoethyl)aminoethyltriisopropoxysilane, 3-(3-aminopropyl) Minopropyltrimethoxysilane, 3-(3-aminopropyl)aminopropyltriethoxysilane, 3-(3-aminopropyl)aminopropyltriisopropoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, N-(n-butyl)-3-aminopropyltrimethoxysilane, N-(n-butyl)-3-aminopropyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyltrimethoxysilane, N-ethyl-γ- Minoisobutyltrimethoxysilane, N-ethyl-γ-aminoisobutyltriethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N-methyl-[3-(trimethoxysilyl)propyl]carbamate, and / or N-trimethoxysilylmethyl-O-methylcarbamate,Examples include bis[γ-(triethoxysilyl)propyl]amine and bis[γ-(trimethoxysilyl)propyl]amine.

[0068] Examples of organosilanes containing at least one thiol group include 3-mercaptopropyltrimethoxysilane (MPTMS), 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltriisopropoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and / or 2-mercaptoethyltriisopropoxysilane.

[0069] Examples of organosilanes containing at least one epoxide group, such as hydroxyl groups masked with protecting groups that can be removed under hydrolysis conditions, include 3-glycidyloxypropyltrimethoxysilane (GLYMO), 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyltriisopropoxyoxysilane, 2-glycidyloxyethyltrimethoxysilane, 2-glycidyloxyethyltriethoxysilane, 2-glycidyloxyethyltriisopropoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and / or β-(3,4-epoxycyclohexyl)ethyltriethoxysilane. Corresponding products are commercially available, for example, under the trade names Silquest® A-186 and A-187.

[0070] As for organosilanes, structural formula (I), AR-Si(R') x (OR'')3- x (I) (wherein A is a functional group that can be optionally masked with a protecting group that can be removed under hydrolysis conditions, or H) R is an aliphatic radical having 1 to 24 or 1 to 12 carbon atoms, an alicyclic radical having 3 to 12 carbon atoms, an aromatic radical having 6 to 12 carbon atoms, or an aromatic aliphatic radical having 7 to 18 carbon atoms. R' radicals are C1~C12 - Selected from the group of alkyl radicals, R'' is an aliphatic radical having 1 to 4 carbon atoms. (x = 0 to 2) It is preferable to use at least one alkoxysilane.

[0071] Here, an aliphatic radical R means an organic radical that does not have an aromatic group, such as a phenyl radical. An aliphatic radical R may have 1 to 24 or 1 to 12 carbon atoms. Preferably, an aliphatic radical R has 2 to 12 carbon atoms, more preferably 3 to 10. An alicyclic radical R means an organic radical that does not have an aromatic group, such as a phenyl radical. An alicyclic radical R may have 3 to 12 carbon atoms, for example, if it is a cyclopropyl group or a cyclohexyl group. Aliphatic radicals and alicyclic radicals may be saturated or unsaturated. An example of an unsaturated aliphatic radical is the ethenyl group in the case of vinyltrimethoxysilane and / or vinyltriethoxysilane. An aromatic radical R means an organic radical composed of an aromatic group, such as a phenylene radical. An aromatic radical R may have 6 to 12 carbon atoms. An aromatic aliphatic radical R means an organic radical that has both an aromatic group and an aliphatic group. An aromatic aliphatic radical R may have 7 to 18 carbon atoms. Radicals such as aliphatic radicals R may also contain heteroatoms such as oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Furthermore, each may contain additional functional groups such as ester groups or urethane groups. More preferably, R is an aliphatic radical having 1 to 12 carbon atoms, or 1 to 10 carbon atoms, very preferably 1 to 8 carbon atoms, and especially 1 to 6 carbon atoms. It will be obvious to those skilled in the art that radical R is a divalent group.

[0072] The most preferred organic silanes are N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (commercially available under the trade names Dynasylan® 1401 from Evonik or Silkquest A-2120 from Momentive), 3-aminopropyltrimethoxysilane (commercially available under the trade name Dynasylan® AMMO), and 3-aminopropyltriethoxysilane (commercially available under the trade names Dynasylan® AMEO or Silkquest A-1100), especially when the optionally coated substrate used in step 1) is a metal substrate.

[0073] The most preferred organic silanes are vinyl-functional oligomer silanes, especially when the optionally coated substrate used in step 1) is a thermoplastic resin, fiber-reinforced composite, or glass substrate. These are commercially available, for example, under the trade names Dynasylan® 6490, Dynasylan® 6498, and Dynasylan® 6598 from Evonik. Vinyltrimethoxysilane (Dynasylan® VTMO), vinyltriethoxysilane (Dynasylan® VTEO), and 3-methacryloxypropyltrimethoxysilane (Dynasylan® MEMO) are particularly preferred.

[0074] Preferably, the molar ratio of components a2) and a3) is in the range of 1:>1.0 to 1:3.0, more preferably 1:1.2 to 1:2.8.

[0075] Any further components of the solvent-type composition The solvent-based composition may contain one or more additional arbitrary components that are different from each other and also different from components a1) to a3).

[0076] Optionally, the composition may include, in particular when the optionally coated substrate used in step 1) is a metal substrate, at least one colorant as component a4) in an amount based on the total mass of the composition in each case, preferably 0 or 0.01 to 1.5% by mass, more preferably 0 or 0.02 to 1.0% by mass, even more preferably 0 or 0.03 to 0.75% by mass, and even more preferably 0 or 0.05 to 0.5% by mass.

[0077] Examples of colorants include pigments and dyes. The use of dyes is particularly preferred. Colorants can be inorganic or organic, and are preferably organic. Organic dyes are the most preferred.

[0078] The colorant can be any colorant, particularly a colorant that dissolves in organic solvents present as component a1). For external adhesion promoters in the aerospace industry, red colorants are most preferred. For example, rhodamine colorants, such as rhodamine B, and azo colorants, such as Macrolex® Red H from Lanxess or Keyplast® Red H from Milliken, can be used.

[0079] It is preferable to add the coloring agent after applying the solvent-based composition as an adhesion promoter, so that the already applied portion is visible. Furthermore, the operator can determine whether the amount of adhesion promoter applied is appropriate from the color tone. Applying too much adhesion promoter will result in a darker color tone, while applying too little will result in a lighter color tone.

[0080] However, in some applications, the presence of colorants may not be desirable, especially when the optionally coated substrate used in step 1) is a thermoplastic resin, fiber-reinforced composite, or glass substrate. For example, in window assembly applications, a portion of the applied adhesion promoter layer may be visible on a transparent substrate even after assembly.

[0081] Optionally, the composition, particularly when the optionally coated substrate used in step 1) is a thermoplastic resin, fiber-reinforced composite or glass substrate, contains as component a5) at least one additive selected from reactive diluents, resins, such as polymer resins, and mixtures thereof, in an amount based on the total mass of the composition in each case, preferably 0 or 0.01 to 7.5% by mass, more preferably 0 or 0.02 to 6.0% by mass, even more preferably 0 or 0.03 to 5.0% by mass, and even more preferably 0 or 0.05 to 4.0% by mass.

[0082] Reactive diluents having at least one epoxide group are particularly preferred. Examples include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and trimethylolpropane polyglycidyl ether. Preferably, the reactive diluent does not have a carbon-carbon double bond. However, such reactive diluents are also generally usable.

[0083] Suitable resins include, in particular, rosin resins (usable in modified forms such as maleic acid-modified rosin resins), colophonium resins, polyesters, and polyurethanes. The resins can be solid or liquid. In the case of solid resins, it is preferable to dissolve them in at least one organic solvent before adding them to the composition.

[0084] In particular, a solvent-type composition is highly preferred when the optionally coated substrate used in step 1) is a metal substrate. As component a1), at least one organic solvent is added in an amount ranging from 87.5% to 99.0% by mass, more preferably 90.0% to 98.0% by mass, even more preferably 92.5% to 97.5% by mass, and even more preferably 94.0% to 97.0% by mass, based on the total mass of the composition in each case. In each case, component a2) is added in an amount ranging from 0.50% to 7.50% by mass, more preferably 0.75% to 5.0% by mass, even more preferably 1.0% to 4.0% by mass, and even more preferably 1.5% to 3.5% by mass, based on the total mass of the composition. In each case, component a3) is added in an amount ranging from 0.50% to 7.50% by mass, more preferably 0.75% to 5.0% by mass, even more preferably 1.0% to 4.0% by mass, and even more preferably 1.5% to 3.5% by mass, based on the total mass of the composition, and Optionally, preferably, component a4) is added in an amount ranging from 0 or 0.01 to 1.5% by mass, more preferably 0 or 0.02 to 1.0% by mass, even more preferably 0 or 0.03 to 0.75% by mass, and even more preferably 0 or 0.05 to 0.5% by mass. This includes, preferably consists of, these.

[0085] Optional step 2) In any step 2), the film obtained from step 1) is dried and / or cured.

[0086] In the present invention, "drying" preferably means physical drying by at least partial evaporation of the organic solvent component a1) present in the composition used. On the other hand, "curing" further includes chemical reactions between at least two components originally present in the composition, and / or between at least one component originally present in the composition and a suitable functional group present on the substrate surface.

[0087] Drying and / or curing is preferably carried out at a temperature in the range of 15°C to 80°C, more preferably in the range of 18°C ​​to 60°C, and particularly in the range of 20°C or 23°C to 50°C. However, preferably, drying and / or curing is carried out simply at room temperature (15 to 23°C), preferably by air blowing. Drying and / or curing is preferably carried out for 5 to 30 minutes, more preferably for 10 to 30 minutes. The selected time depends on the ambient temperature and humidity. The dried and / or cured film forms a layer.

[0088] Preferably, by carrying out any step 2), components a2) and / or a3) bond to the substrate surface and a hydrolysis reaction occurs. The hydrolyzed components then form an adhesion-promoting layer. As already outlined in relation to step 1), the thickness of the resulting dry layer is preferably less than 1.0 μm, more preferably less than 900 nm or less than 800 nm, even more preferably less than 700 nm or less than 600 nm, even more preferably less than 500 nm or less than 400 nm, and most preferably less than 300 nm or less than 200 nm.

[0089] Process 3) In step 3), a sealant composition different from the solvent-type composition used in step 1) is applied at least partially to an optionally dried and / or cured film obtained after step 1) or 2) to form a sealant film.

[0090] Any contact method, such as brushing and / or spraying, may be used for application in step 3). Step 3) is preferably carried out at a temperature in the range of 0 to 60°C, more preferably in the range of 5 to 45°C. In particular, no heating is performed.

[0091] Preferably, step 3) is carried out using a 2K compressed air support cartridge device having a 2K low-pressure or 2K high-pressure discharge system. It can also be carried out manually.

[0092] sealant composition used in step 3) The sealant composition used in step 3) is obtained by mixing components A) and B) of at least two separately existing sealing systems with each other. Preferably, the sealing system consists of components A) and B). For example, components A) and B) of the sealing system can be stored separately until they are mixed with each other to prepare the sealant composition. Component A) of the sealing system comprises at least one polymer component A1) having two or more thiol groups selected from polyethers, polythioethers, polysulfides, polythioether-sulfide components, and mixtures thereof, and component B) of the sealing system comprises at least one component B0) suitable for curing the sealant composition by at least partially inducing a chemical conversion of two or more thiol groups of component A1).

[0093] Each of the two components A) and B) of the sealing system may contain water and / or at least one organic solvent. However, it is also possible, and rather preferable, that the system may not contain an organic solvent and / or water.

[0094] The amount of water present in component A) is preferably less than 3.0% by mass, more preferably less than 2.0% by mass, even more preferably less than 1.0% by mass, and even more preferably less than 0.5% by mass, based on the total mass of component A) in each case. If component (B) contains at least one component B1) and / or at least one component B3) and / or at least one component B4) as component B0), the amount of water present in component (B) is preferably less than 3.0% by mass, more preferably less than 2.0% by mass, even more preferably less than 1.0% by mass, and even more preferably less than 0.5% by mass, based on the total mass of component B) in each case. Components B1), B3), and B4) will be defined below. If component B) contains at least one component B2), such as manganese dioxide, as component B0), the amount of water present in component B) is preferably less than 8.5% by mass, more preferably less than 7.5% by mass, even more preferably less than 7.0% by mass, and even more preferably less than 6.0% by mass, based on the total mass of component B) in each case. Component B2) will be defined later.

[0095] If at least one organic solvent is present, it is preferable that the organic solvent is present in an amount of 70% by mass or less, or 65% by mass or less, based on the total mass of the sealant composition, particularly when the sealant composition is a sprayable composition. In this case, it is preferable that the sealant composition contains up to 60% by mass of the organic solvent based on the total mass of each composition. Alternatively, if at least one organic solvent is present, it is preferable that the organic solvent is present in an amount of up to 10% by mass, based on the total mass of the sealant composition, particularly when the sealant composition is not a sprayable composition. In this case, the sealant composition preferably contains up to 7.5% by mass, more preferably up to 5% by mass, of the organic solvent based on the total mass of the composition in each case. Any conventional organic solvent known to those skilled in the art can be used as the organic solvent. The term "organic solvent" is known to those skilled in the art, particularly from Council Directive 1999 / 13 / EC of March 11, 1999. Examples of such organic solvents include heterocyclic, aliphatic, or aromatic hydrocarbons, monohydric or polyhydric alcohols, particularly ethanol and / or propanol, ethers, esters, ketones, xylene, butanol, ethyl glycol and butyl glycol and their acetates, butyl diglycol, diethylene glycol dimethyl ether, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, acetone, isophorone, or mixtures thereof. The solvents present may be identical or different from each other.

[0096] Preferably, the sealing composition is obtained by mixing component A) and component B) in a mass ratio (component A) / component B)) in the range of 100:1 to 1:1. More preferably, the mixing is carried out in a mass ratio in the range of 100:1 to 1.1:1, even more preferably in the range of 100:1 to 2:1, particularly in the range of 100:1 to 3:1, and most preferably in the range of 20:1 to 4:1.

[0097] Component A of the sealing system) Component A1) Component A) of the sealing system includes at least one polymer component A1) containing two or more thiol groups (mercapto groups), selected from polyethers, polythioethers, polysulfides, polythioether-sulfide components and mixtures thereof, more preferably selected from polythioethers, polysulfides, polythioether-sulfide components and mixtures thereof, and particularly selected from polythioethers, polysulfide components and mixtures thereof. The terms “polymer” and “polymeric” are well known to those skilled in the art and for the purposes of the present invention include polyadditives, polymers, and polycondensates. The term “polymer” includes both homopolymers and copolymers.

[0098] The presence of a thiol group necessarily means that A1) is a sulfur atom-containing component. The thiol group of A1) can react chemically with component B0) or a part of it (e.g., its appropriate functional group). For example, if component B1) is present as component B0), its epoxy group reacts to form at least one of a hydroxythioether, a hydroxythioether sulfide, and / or a hydroxysulfide moiety. For example, if component B2) containing a manganese oxide is present as component B0), an SS bond is formed.

[0099] Preferably, polymer component A1) contains terminal thiol groups. Component A1) can be branched or linear. Preferably, polymer component A1) is liquid under room temperature conditions (18-23°C, 50% relative humidity).

[0100] Polymer components that can be used as A1) are disclosed, for example, in US 2004 / 097643 A1, WO 2016 / 128548 A1, and WO 2015 / 014876 A2.

[0101] When at least one polythioether is used as A1), it is preferably a liquid polythioether (under room temperature conditions). The polythioether may contain up to about 50 mol% of disulfide groups in its molecule. In this case, the corresponding polymer is named polythioether sulfide. Preferred compounds of this type are described in WO 2015 / 014876 A2.

[0102] Preferably, polymer component A1) has a number-average molecular weight in the range of 500 to 10,000 g / mol, more preferably 900 to 5,000 g / mol. In particular, when A1) is at least one polysulfide, most preferably the number-average molecular weight is in the range of 2,500 to 6,000 g / mol, more preferably 3,300 to 5,000 g / mol. Examples of such polymers include polysulfides commercially available under trade names such as Thioplast® G131, Thioplast® G10, Thioplast® G12, Thiokol® LP 32 and / or Thiokol® LP 12. Polymer component A1) having a number-average molecular weight in the range of 500 to 2,500 g / mol, more preferably 700 to 2,000 g / mol or 800 to 1,200 g / mol is also preferred. In this case, examples of such polymers include polysulfides that are commercially available under trade names such as Thiokol® LP3, Thioplast® G4, or Thioplast® G44.

[0103] Optionally, component (A) may contain at least two different constituent components A1) having different number-average molecular weights: in addition to short-chain polymers having a number-average molecular weight particularly in the range of 500 to 2500 g / mol, especially preferably in the range of 800 to 1500 g / mol, there may also be long-chain polymers having a number-average molecular weight particularly in the range of 2500 to 6000 g / mol, especially preferably in the range of 3300 to 5000 g / mol. Optionally, at least one of the short-chain polymers used in combination with the at least one long-chain polymer may be substituted with at least one polymer, oligomer, or monomer mercaptan, preferably solid or liquid, having three thiol groups and a number-average molecular weight in the range of 160 to 1200 g / mol. Alternatively, the mercaptan may be further added to the combination of at least one short-chain polymer and at least one long-chain polymer. Examples of suitable mercaptans include thiocyanuric acid (1,3,5-triazine-2,4,6-trithiol) and benzene-1,3,5-trithiol (1,3,5-trimercaptobenzene). If the mercaptan used is nonpolymeric, it formally represents any component A6) of component A) described later. Preferably, if present, at least one mercaptan is present in an amount ranging from 0.05 to 3.0% by mass based on the total mass of component A).

[0104] The sulfur-containing polymer component A1) has a mercaptan content based on reactive SH groups, preferably in the range of 0.5 to 10.0% by mass, more preferably 0.8 to 8.0% by mass, and particularly 1.2 to 7.0% by mass, based on the total mass of A1). The mercaptan content can be measured by directly titrating the polymer having SH ends with an iodine solution: the polymer is dissolved in a solvent mixture consisting of 40% by volume pyridine and 60% by volume benzene, and titrated with benzene-iodine solution while stirring until a faint yellow color remains. Preferably, component A1) has a total sulfur content in the range of 1 to 50% by mass, more preferably 5 to 45% by mass, and particularly 12 to 36% by mass. Preferably, component A1) has an average functional value of 1.5 to 2.5 or 1.9 to 2.2 per molecule of mercapto groups as reactive end groups. The functional value indicates the average number of mercapto groups per molecule. This is calculated as the ratio of molecular weight to equivalent mass and can be measured by NMR. Preferably, component A1) has an average glass transition temperature Tg measured according to AITM 1-0003 Airbus Industrie Test Method, June 1995, in the range of -80 to -30°C or -60 to -40°C.

[0105] Preferably, component A1) and such sealant compositions do not contain any components containing (meth)acrylate groups (methacrylate groups and / or acrylate groups).

[0106] Preferably, component A1) is present in the sealant composition obtained by mixing components A) and B) of the sealing system together in an amount ranging from 50 to 95% by mass based on the total mass of the sealant composition.

[0107] Any component present in component A) Component A) may optionally further contain at least one organosilane A2), at least one filler A3), and / or at least one pigment A4). Organosilane A2) may be the same as or different from component a3) described above and below.

[0108] The term “filler” is well known to those skilled in the art, for example, from DIN 55943 (dated October 2001). In the present invention, “fillers” are preferably substantially, preferably completely insoluble components in the surrounding medium, e.g., each component A) and B) and the sealant composition. They are particularly used for adjusting the viscosity and thixotropy of the components and sealant composition, adjusting the specific gravity of the cured sealant, and / or improving the mechanical properties of the cured sealant. In the present invention, “fillers” differ from “pigments” in their refractive index. The refractive index of fillers is less than 1.7, while that of pigments is 1.7 or greater. Preferably, the “fillers” in the present invention are inorganic and / or organic fillers. Examples of inorganic fillers include chalk and talc. Examples of organic fillers include powders prepared from heat-resistant polymers such as polyamides, polysulfones, polyphenylene sulfides, and polyetherketones, and polymer hollow spheres. Preferably, the amount of filler present in component A) of the sealing system is in the range of 0 to 55.0% by mass, more preferably 0 to 50.0% by mass, even more preferably 0 to 45.0% by mass, even more preferably 0 to 40.0% by mass, even more preferably 0 to 35.0% by mass or 0 to 30.0% by mass, particularly 0 to 25.0% by mass, based on the total mass of component A) in each case. Preferably, the amount of pigment present in component A) of the sealing system is in the range of 0 to 35.0% by mass, more preferably 0 to 30.0% by mass, even more preferably 0 to 25.0% by mass, even more preferably 0 to 20.0% by mass, and even more preferably 0 to 15.0% by mass, based on the total mass of component A) in each case. The term "pigment" is well known to those skilled in the art, for example from DIN 55943 (October 2001). In the present invention, "pigment" refers to a component, preferably in powder or flake form, which is substantially, preferably completely insoluble in the surrounding medium, such as components A) and B) and the sealant composition, and is a substance that can be used as a colorant and / or pigment due to its magnetic, electrical and / or electromagnetic properties.Preferably, the "pigment" in the present invention is an inorganic and / or organic pigment. An example of an inorganic pigment is titanium dioxide.

[0109] Component A) of the sealing system may include one or more optional components A5) and / or A6).

[0110] Component A) may, preferably, further include at least one curing catalyst A5) if component B) of the sealing system includes at least one component B1) containing two or more epoxide groups as component B0). Suitable curing catalysts include amines, particularly tertiary amines, amidines, and / or guanidines. Examples include 1,4-diazabicyclo(2.2.2)octane, 1,5-diazabicyclo(4.3.0)non-5-ene (DBN), and 1,8-diazabicyclo(5.4.0)unde-7-ene (DBU).

[0111] Component A6) may be a flame retardant, such as a phosphorus-containing flame retardant, particularly one phosphate ester. When a flame retardant is used, it is preferably liquid (at 1 bar, 23°C). If a flame retardant is present in component A), it is preferably present in an amount of 0.1 to 30.0% by mass, more preferably 1.0 to 25.0% by mass, and particularly 5.0 to 20.0% by mass, based on the total mass of component A). Component A6) may also be a light stabilizer, particularly an ultraviolet stabilizer. An example is sterically hindered amines (HALS: sterically hindered amine light stabilizers). In principle, all commercially available light stabilizers from the Tinuvin® series or other manufacturers can be used. Liquid light stabilizers are preferred. If a light stabilizer is present in component A), it is preferably present in an amount of 0.05 to 5.0% by mass, more preferably 0.1 to 3.5% by mass, and particularly 0.1 to 2.0% by mass, based on the total mass of component A). Component A6) may be an additional adhesion promoter in addition to the aforementioned organic silane component A2) which may be optionally present. Furthermore, or instead, other adhesion promoters such as those included in component A2) described above and below may be used. If an additional adhesion promoter is present in component A), it is preferably present in an amount of 0.05 to 5.0% by mass, more preferably 0.1 to 3.5% by mass, and particularly 0.1 to 2.0% by mass, based on the total mass of component A). Component A6) is an additive selected from the group consisting of defoamers, rheological additives, plasticizers such as phthalates, and viscosity reducers, particularly non-reactive viscosity reducers such as naphthalene derivatives and / or hydrocarbon mixtures based on indene-coumarone resin, tall oil and rapeseed methyl ester (biodiesel) and rapeseed oil and / or other ester diluents, and mixtures of these additives. If component A) contains at least one additive, its content is preferably 0.05 to 40.0% by mass, more preferably 0.1 to 30.0% by mass, and particularly 0.1 to 20.0% by mass, based on the total mass of component A). Specifically, if at least one defoaming agent is present, its amount is preferably in the range of 0.1 to 2.5% by mass, based on the total mass of component A).Specifically, if at least one reactive diluent is present, its amount is preferably in the range of 0.1 to 20.0% by mass based on the total mass of component A). Specifically, if at least one rheological additive is present, its amount is preferably in the range of 0.1 to 5.0% by mass based on the total mass of component A). Specifically, if at least one plasticizer is present, its amount is preferably in the range of 0.1 to 2.5% by mass based on the total mass of component A). Specifically, if at least one viscosity reducing agent is present, its amount is preferably in the range of 0.1 to 20.0% by mass based on the total mass of component A). As outlined above in relation to component A1), component A6) may further contain at least one nonpolymer mercaptan having three thiol groups and a number-average molecular weight in the range of 160 to 800 g / mol. Preferably, the at least one nonpolymer mercaptan (if present) is present as component A6) in an amount ranging from 0.05 to 3.0% by mass, more preferably 0.05 to 1.5% by mass, based on the total mass of component A).

[0112] Component B of the sealing system) (Component B0) Component B) of the sealing system comprises at least one component B0), which is suitable for curing the sealant composition by at least partially inducing a chemical transformation of two or more thiol groups of component A1). That is, component B0) or a portion thereof can chemically react with the thiol groups of component A1). Thus, component B0) represents a curing agent. The resulting chemical transformation may apply to all of the thiol groups of component A1) or to only some of the thiol groups of component A1). However, preferably, the chemical transformation is induced not only partially but substantially to all of the thiol groups of component A1).

[0113] Preferably, at least one component B0) is selected from components containing two or more epoxide groups (component B1)), components that are metal oxides and / or metal peroxides, particularly manganese dioxide (component B2)), components that are organic peroxides (component B3)), components containing two or more vinyl groups (component B4)), and mixtures thereof; more preferably, it is selected from the group consisting of components containing two or more epoxide groups (component B1)), components that are metal oxides and / or metal peroxides, particularly manganese dioxide (component B2)), and mixtures thereof, in particular, component B1) represents at least one component containing two or more epoxide groups, or component B2) represents at least one metal oxide and / or metal peroxide, particularly manganese dioxide.

[0114] Preferably, component B0) is present in component B) of the sealing system used to prepare the sealant composition applied in step 3) in an amount ranging from 30 to 100% by mass based on the total mass of component B).

[0115] (Component B1) Component B1) contains two or more epoxide groups. Preferably, the epoxide groups are present as terminal groups in B1). Component B1) can be a monomer, oligomer, or polymer. Preferably, B1) is aliphatic and / or aromatic.

[0116] Preferably, component B1) is present in component B) of the sealing system used to prepare the sealant composition applied in step 3) in an amount ranging from 50 to 100% by mass based on the total mass of component B). Preferably, B1) has an epoxide functional value of 2.0 to 5.0, more preferably 2.0 to 3.0, and particularly 2.2 to 2.8.

[0117] Component B1) is particularly selected from diglycidyl ethers of bisphenol A, diglycidyl ethers of bisphenol F, aliphatic polyglycols, and / or epoxy derivatives of hydantoin. Epoxy-terminated polythioethers or polythioether sulfides, and / or epoxidized polysulfides can also be used. Particularly preferred is at least one epoxy novolac resin (epoxidized phenol formaldehyde resin), preferably a crosslinked epoxy novolac resin. It is also possible to use multiple components B1) based on the above classifications (e.g., bisphenol A / F epoxy resins or bisphenol F novolac resins). Component B) may further contain diluents, for example, to adjust viscosity and flexibility. Examples of diluents include 1,4-butanediol diglycidyl ether, 2-ethylhexylglycidyl ether, and 1,6-hexanediol diglycidyl ether.

[0118] Preferably, B1) is a polysulfide polymer and / or polythioether polymer and / or polythioether sulfide polymer having at least one epoxide-terminated polysulfide polymer and / or polythioether sulfide polymer that does not have terminal mercapto groups, and functions as a curing agent by its two terminal epoxide groups. This polymer is preferably in the form of a liquid or high-viscosity polymer having an epoxy equivalent in the range of 200 to 800 g / eq. Preferably, the epoxy (epoxide) equivalent of B1) is in the range of 120 to 800 g / eq, particularly preferably in the range of 140 to 700 g / eq, and most preferably in the range of 170 to 400 g / eq.

[0119] Most preferably, the component B1) is based on a bisphenol A epoxy resin having an epoxy equivalent in the range of 170 to 200 g / eq, a bisphenol F resin having an epoxy equivalent in the range of 150 to 180 g / eq, and an epoxy novolac resin having an epoxy equivalent in the range of 160 to 220 g / eq. Examples of suitable commercially available products include, for example, bisphenol F epoxy resins, e.g., DEN 354 (Olin Epoxy); bisphenol A resins, e.g., DER 336, DER 331 (Olin Epoxy); bisphenol A / F epoxy resins, e.g., DER 351, DER 324, DER 335 (Olin Epoxy); epoxy novolac resins, e.g., DEN 431, DEN 438, DEN 439 (Olin Epoxy); polysulfide and / or polythioether-based epoxy-terminated prepolymers, e.g., Thioplast EPS 25 (Akzo Nobel); and alcohol / glycol-based epoxy-terminated reactive diluents, e.g., 1,4-butanediol diglycidyl ether (DER 731; Olin Epoxy) and 1,6-hexanediol diglycidyl ether (DER 734; Olin Epoxy).

[0120] Preferably, the molar ratio of all components B1) to all components A1) is in the range of 0.90:1 to 2:1.

[0121] Component B2) Component B2) is at least one metal oxide and / or metal peroxide, in particular manganese dioxide. Manganese dioxide means manganese(IV) oxide. Another suitable component B2) is calcium peroxide.

[0122] Preferably, component B2) is present in component B) of the sealing system used to prepare the sealant composition applied in step 3) in an amount ranging from 30 to 90% by mass based on the total mass of component B).

[0123] (Component B3) Component B3) is at least one organic peroxide. Examples of suitable organic peroxides include organic hydroperoxides such as cumenyl hydroperoxide.

[0124] Preferably, component B3) is present in component B) of the sealing system used to prepare the sealant composition applied in step 3) in an amount ranging from 30 to 100% by mass based on the total mass of component B).

[0125] Component B4) Component B4) contains two or more vinyl groups. Preferably, the vinyl groups are present as terminal groups in B4). Component B4) can be a monomer, oligomer, or polymer, and is preferably a monomer. Preferably, B4) is aliphatic and / or aromatic. Examples of component B4) include divinyl ethers, such as diethylene glycol divinyl ether, triethylene glycol divinyl ether, and butanediol divinyl ether.

[0126] Preferably, component B4) is present in component B) of the sealing system used to prepare the sealant composition applied in step 3) in an amount ranging from 30 to 100% by mass based on the total mass of component B).

[0127] When component B4) is used as component B0) of component B), it is preferable that it be included in combination with at least one radical generator. Examples of suitable radical generators include 1-hydroxycyclohexylphenyl ketone and 2-hydroxy-2-methyl-1-phenylpropan-1-one.

[0128] Any component B5), B6), and B7) Component B) of the sealing system may contain one or more arbitrary components B5). Component B5) may be an additive selected from the group consisting of reactive diluents, e.g., bisoxazolidine and / or aldimines, and plasticizers, e.g., furarates. In particular, if component B) of the sealing system contains at least one component B2), especially manganese dioxide, then component B) may contain at least one plasticizer component B5).

[0129] Specifically, if at least 1 ton of reactive diluent is present, the amount is preferably in the range of 0.1 to 20.0% by mass relative to the total mass of component B). Specifically, if at least one plasticizer is present, the amount is preferably in the range of 10.0 to 70.0% by mass relative to the total mass of component B).

[0130] Component B) may, and preferably may, contain at least one curing catalyst B6).

[0131] As described above, if component B) of the sealing system includes at least one component B1) having two or more epoxide groups as component B0), then at least one curing catalyst, if present, is preferably present as component A5) in component A) and not in component B). Suitable curing catalysts in this case are amines, particularly tertiary amines, amidines and / or guanidines. Examples include 1,4-diazabicyclo(2.2.2)octane, 1,5-diazabicyclo(4.3.0)non-5-ene (DBN), and 1,8-diazabicyclo(5.4.0)unde-7-ene (DBU).

[0132] If component B) of the sealing system contains at least one component B2) as component B0), preferably component B) contains at least one curing catalyst B6). Suitable curing catalysts in this case include, for example, tetrabenzyl thiuram disulfide, diphenylguanidine, and / or zinc bis(diethyldithiocarbamate).

[0133] If component B) of the sealing system contains at least one component B3) as component B0), preferably component B) contains at least one curing catalyst B6). A suitable curing catalyst in this case is, for example, zinc bis(diethyldithiocarbamate).

[0134] If component B) of the sealing system contains at least one component B4) as component B0), preferably component B) contains at least one curing catalyst B6). Suitable curing catalysts in this case are particularly suitable photoinitiators, such as acetophenone, benzoin ether, and / or benzoyl oxime. Curing is preferably carried out by ultraviolet light.

[0135] Component B) may contain at least one flame retardant B7). Component B7) may be a phosphorus-containing flame retardant, particularly at least one phosphate ester. When a flame retardant is used, it is preferably in liquid form (at 1 bar and 23°C). If component A) contains a flame retardant, its content is preferably 5.0 to 65.0% by mass, more preferably 25.0 to 65.0% by mass, particularly 40.0 to 65.0% by mass, based on the total mass of component B).

[0136] Optional step 4) In an optional step 4), the sealant film obtained after step 3) is cured. Preferably, curing is carried out at room temperature (18-23°C) or under elevated temperatures such as 80°C for 0.5 hours to 14 days.

[0137] Preferably, curing by any step 4) means chemical curing, such as chemical crosslinking at room temperature or under elevated temperature. If at least one component B1) or B4) is used as component B0), curing may be additionally or alternatively induced by ultraviolet light.

[0138] Preferably, the sealant composition is applied with a dry layer thickness in the range of 15 μm to 20 mm, more preferably in the range of 50 μm to 15 mm, and particularly in the range of 0.5 to 10 mm.

[0139] sealed substrate A further subject of the present invention is a sealed substrate that can be obtained by the method of the present invention, which is preferably suitable for use in aircraft and / or the aerospace industry.

[0140] All preferred embodiments described herein in relation to the method and preferred embodiments thereof of the present invention are also preferred embodiments of the sealed substrate of the present invention.

[0141] Use as an adhesion promoter A further subject of the present invention is a method of using a solvent-type composition used and defined in step 1) of the above-described method as an adhesion-promoting composition, in particular to improve the adhesion between the surface of an optionally pre-coated substrate and a subsequently applied sealant film.

[0142] All preferred embodiments described above in relation to the method of the present invention and the sealed substrate of the present invention, as well as preferred embodiments thereof, are also preferred embodiments in the method of use of the present invention.

[0143] The sealant film is preferably obtained by applying a sealant composition obtained by mixing at least two separately existing components A) and B) of the sealing system with each other, in particular by applying the sealant composition to a film already present on the surface of an optionally pre-coated substrate, wherein component A) of the sealing system comprises at least one polymer component A1) containing two or more thiol groups, selected from polyethers, polythioethers, polysulfides, polythioether-sulfide components and mixtures thereof, and component B) of the sealing system comprises at least one component b) suitable for curing the sealant composition by at least partially inducing a chemical conversion of two or more thiol groups of component A1), and the film is formed by at least partially applying the solvent-type composition defined in step 1) of the method to the surface.

[0144] Solvent-type composition A further subject of the present invention is a solvent-type composition as defined in relation to step 1) of the above method.

[0145] All preferred embodiments described above with respect to the methods of the present invention, the sealed substrates of the present invention, the methods of use of the present invention, and preferred embodiments thereof are also preferred embodiments of the solvent-type compositions of the present invention.

[0146] Kit of Parts A further subject of the present invention is a kit of parts comprising, preferably separately from each other, a sealing system comprising at least two components A) and B) separated from each other as defined in relation to step 3) of the above method, and a solvent-based composition defined in relation to step 1) of the above method or the solvent-based composition of the present invention, separated from each other.

[0147] All preferred embodiments described above in relation to the methods of the present invention, the sealed substrates of the present invention, the methods of use of the present invention, and the compositions of the present invention, and their preferred embodiments, are also preferred embodiments of the kit of parts of the present invention.

[0148] method 1. Peel test Peel test specimens were prepared and cured at room temperature (23°C) and 50% relative humidity for 14 days. Tests were then conducted according to DIN 65262-1 (07-2017). The occurrence of cohesive failure or interfacial delamination (adhesion failure) was evaluated.

[0149] 2.Number average molecular weight The number-average molecular weights of components A21) and B1) are measured by GPC (gel permeation chromatography) using a polystyrene standard as the reference. THF (tetrahydrofuran) is used as the mobile phase. The number-average molecular weights of organosilane components A2) and a3) are measured by NMR spectroscopy for monomer and oligomer components, and by GPC for polymer components.

[0150] 3. Flash point The flash point was determined using the Miniflash FLPL apparatus in accordance with ASTM D6450.

[0151] 4. Dry film thickness In particular, the dry layer thickness of the film obtained after any step 2) in the method of the present invention was measured using REM / EDX (scanning electron microscope / energy dispersive X-ray analysis). [Examples]

[0152] The following embodiments further illustrate the present invention, but do not limit its scope. "Pbw" means parts by mass. Unless otherwise defined, "parts" means "parts by mass".

[0153] 1. Adhesion promoting composition 1.1 Exemplary composition E1 was prepared by mixing the components listed in Table 1.1 in the order shown in Table 1.1.

[0154] [Table 1]

[0155] For zirconate 1, a commercially available product containing tetra-n-butanolate zirconium (87% by mass) in n-butanol was used. A commercially available xanthene-based colorant was used as dye 1. Silane 1 was a commercially available organic silane, namely N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane.

[0156] Composition E1 was prepared as follows: The organic solvent used was weighed into a resealable glass bottle. Next, zirconate 1 was added. The glass bottle was sealed and shaken carefully. Then, silane 1 was added. The glass bottle was sealed and shaken carefully. Finally, dye 1 was added. The glass bottle was sealed and shaken carefully.

[0157] 1.2 Furthermore, exemplary compositions E2, E3 and comparative composition C1 were prepared by mixing the components listed in Table 1.2 in the order shown in Table 1.2.

[0158] [Table 2]

[0159] For zirconate 1, a commercially available product containing tetra-n-butanolate zirconium (87% by mass) in n-butanol was used. For dye 2, a commercially available azo-based red coloring agent was used. Silane 1 was a commercially available organic silane, namely N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane.

[0160] In composition C1, the diol used was completely replaced with a monoalcohol compared to composition E3.

[0161] 1.3 Comparative compositions C2, C3, and C4 were further prepared by mixing the components listed in Table 1.3 in the order shown in Table 1.3.

[0162] [Table 3]

[0163] For zirconate 2, a commercially available product containing tetra-n-propanolate zirconium (74% by mass) in n-propanol was used. For dye 2, a commercially available azo red dye was used. Silane 1 is a commercially available organic silane, namely N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane. Silane 2 is a commercially available organic silane, namely N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

[0164] 2. Characterization of adhesion-promoting compositions The flash points of adhesion-promoting compositions E2, E3, and C1-C4 were measured according to the method described in the "Methods" section. The results are shown in Table 2. A higher flash point indicates a lower risk. Therefore, a high flash point, especially one above 40°C, is desirable.

[0165] [Table 4]

[0166] As is clear from Table 2, when a mixture of diol and monoalcohol is used as the organic solvent in compositions E2 and E3, a sufficiently high flash point of over 40°C is obtained. Specifically, in both cases, it is 41°C. Comparing E2 and E3, it can be seen that reducing the amounts of zirconate and silane does not affect the flash point.

[0167] Comparing E3 and C1, it is evident that using only monoalcohols without diols results in an undesirable outcome: the flash point drops below 40°C, specifically to 37°C. The use of different zirconates or silanes does not affect this result, as is clear from comparing the flash points of C1, C2, and C3. Using only isopropanol as the alcohol further reduces the flash point significantly, to a very low 16°C, as is clear from comparing the flash points of C1 and C4.

[0168] 3. Preparation of sealed substrates and investigation of their properties Sealed substrate prepared using exemplary adhesion-promoting composition E1 Multiple substrates S1 to S8 were prepared. Specifically, these were titanium grade 5 (S1), stainless steel 304 (S2), aluminum 2024 T3 clad (S3), carbon fiber composite (CFC) HexPly® M21E (S4), substrate S3 (S5) coated with a commercially available primer coat (Mankiewicz Seevenax 313-02), substrate S3 (S6) coated with a commercially available primer coat (Akzo® 37092), substrate S3 (S7) coated with a commercially available polyurethane topcoat (Akzo® HS 67348), and substrate S3 (S8) coated with a commercially available polyurethane topcoat (Akzo® C21 / 100).

[0169] Each of the substrates S1 to S8 was cleaned with an appropriate solvent (mixture) according to the substrate manufacturer's recommendations. This removed dirt, grease, oil, or dust from the substrate surface before applying the adhesion-promoting composition.

[0170] Adhesion-promoting composition E1 was applied to the cleaned surface of each substrate in an extremely thin layer (dry film thickness ≤ 200 nm) using the "wipe-on / wipe-off" method. This method involves applying an excess of adhesion-promoting composition E1 to the substrate surface using a brush, a soft lint-free wipe, or a felt-tipped pen. After a few seconds to a few minutes (depending on the substrate used), the excess was wiped off with a soft lint-free wipe, followed by a flash-off time. During this time, at least some of the present organic solvents evaporate, and hydrolysis reactions involving the components of the applied composition E1 occur. The length of the flash-off time varies depending on the ambient temperature and humidity. Here, a flash-off time of 30 minutes was used.

[0171] Subsequently, an aerospace sealant was applied. In both cases, the commercially available sealant Naftoseal® MC-238M B-2 (manufactured by Chemetall GmbH) was used. This is a two-component, manganese dioxide-curing, liquid polysulfide sealant.

[0172] After application to the substrate surface, the applied sealant was cured for 14 days under conditions of room temperature (23°C) and 50% relative humidity. Subsequently, the sealed substrate was subjected to a peel test according to the method described in the "Methods" section. The results are summarized in Table 3. Cf represents cohesive failure.

[0173] [Table 5]

[0174] Table 3 clearly shows that 100% adhesion can be achieved for various substrates S1-S8 tested using adhesion promoter composition E1 (no adhesion failures were observed, only cf). E1 has lower toxicity compared to other commercially available adhesion promoters (e.g., Naftoseal® MC-110 and Naftoseal® MC-115), and exhibits comparable efficiency despite having a lower active ingredient content compared to Naftoseal® MC-110 and Naftoseal® MC-115. Furthermore, E1 has a higher flash point, i.e., above 40°C, compared to Naftoseal® MC-110 and Naftoseal® MC-115, which have flash points below 40°C.

Claims

1. At least steps 1) and 3), optionally at least one of steps 2) and / or 4), i.e. 1) A step of applying a solvent-type composition to at least a portion of the surface of a substrate that has been optionally pre-coated to form a film on at least a portion of the surface. 2) Optionally, a step of drying and / or curing the film obtained after step 1), 3) A step of forming a sealant film by applying a sealant composition different from the solvent-type composition used in step 1) to at least a portion of the optionally dried and / or cured film obtained after step 1) or 2), The sealant composition can be obtained by mixing at least two separately existing components A) and B) of a sealing system, wherein component A) of the sealing system comprises at least one polymer component A1) containing two or more thiol groups, selected from polyethers, polythioethers, polysulfides, polythioether-sulfide components and mixtures thereof, and component B) of the sealing system comprises at least one component B0) suitable for curing the sealant composition by at least partially inducing the chemical conversion of two or more thiol groups of component A1), 4) Optionally, a step to cure the sealant film obtained after step 3). A method for sealing an optionally pre-coated substrate, including, The solvent-type composition applied in step 1) consists of at least two different components a1) to a3), i.e., As component a1), at least two organic solvents in an amount of at least 85.0% by mass relative to the total mass of the composition, wherein the at least two organic solvents are alcohols and are different from each other, at least one of the at least two alcohols has exactly one OH group, and at least one of the other alcohols has at least two or more OH groups, The constituent component a2) is at least one organic metalate, wherein the metal of the metalate is selected from Ti and Zr, and As component a3), at least one organosilane in an amount of up to 10.0% by mass relative to the total mass of the composition. Includes, A method wherein the total amount of all components present in the solvent-type composition is 100% by mass.

2. The method according to claim 1, wherein the solvent-type composition used in step 1) contains the at least two organic solvents as component a1) in an amount ranging from 85.0% to 99.0% by mass, preferably 85.0% to 98.5% by mass, more preferably 85.0% to 98.0% by mass, more preferably 87.5% to 97.5% by mass, more preferably 90.0% to 97.5% by mass, more preferably 92.5% to 97.5% by mass, and most preferably 95.0% to 97.0% by mass.

3. The method according to claim 1 or 2, wherein the at least two organic solvents as constituent component a1) each have 3 to 10 or 4 to 7 single atoms.

4. The method according to claim 1 or 2, wherein the amount by mass of at least one alcohol having exactly one OH group exceeds the amount by mass of at least one alcohol having two or more OH groups, preferably the relative mass ratio of at least one alcohol having exactly one OH group to at least one alcohol having two or more OH groups is in the range of 5:1 to 3:1, and in particular, if the optionally coated substrate used in step 1) is a metal substrate, the at least two alcohols are present in the solvent-type composition.

5. The method according to claim 1 or 2, wherein the solvent-type composition used in step 1) contains component a2) in an amount ranging from 0.1% to 15.0% by mass, preferably 0.25% to 12.0% by mass, more preferably 0.5% to 10.0% by mass, more preferably 0.75% to 7.5% by mass, and more preferably 1.0% to 5.0% by mass, based on the total mass of the composition in each case.

6. The method according to claim 1 or 2, wherein the solvent-type composition used in step 1) contains component a3) in an amount ranging from 0.1% to 10.0% by mass, more preferably 0.25% to 8.0% by mass, more preferably 0.5% to 6.0% by mass, more preferably 0.75% to 5.0% by mass, and more preferably 1.0% to 5.0% by mass, based on the total mass of the composition in each case.

7. The solvent-type composition used in step 1) is In particular, if the optionally coated substrate used in step 1) is a metal substrate, at least one colorant is included as component a4) in an amount ranging from 0.01 to 1.5% by mass based on the total mass of the composition, and / or As component a5), at least one additive selected from reactive diluents, resins, such as polymer resins, and mixtures thereof is added in each case, based on the total mass of the composition, in an amount ranging from 0 or 0.01 to 7.5% by mass, preferably in the range of 0 or 0.02 to 6.0% by mass, more preferably in the range of 0 or 0.03 to 5.0% by mass, and more preferably in the range of 0 or 0.05 to 4.0% by mass. The method according to claim 1 or 2, further comprising:

8. In particular, when the optionally coated substrate used in step 1) is a metal substrate, the solvent-type composition used in step 1) is As component a1), at least two organic solvents are added in an amount ranging from 87.5% to 99.0% by mass, preferably 90.0% to 98.0% by mass, more preferably 92.5% to 97.5% by mass, and more preferably 94.0% to 97.0% by mass, based on the total mass of the composition. In each case, component a2) is added in an amount ranging from 0.50% to 7.50% by mass, preferably 0.75% to 5.0% by mass, more preferably 1.0% to 4.0% by mass, and more preferably 1.5% to 3.5% by mass, based on the total mass of the composition. In each case, component a3) is added in an amount ranging from 0.50% to 7.50% by mass, preferably 0.75% to 5.0% by mass, more preferably 1.0% to 4.0% by mass, and more preferably 1.5% to 3.5% by mass, based on the total mass of the composition, and Optionally, preferably, as component a4), at least one coloring agent is added in an amount ranging from 0 or 0.01 to 1.5% by mass, more preferably 0 or 0.02 to 1.0% by mass, more preferably 0 or 0.03 to 0.75% by mass, and more preferably 0 or 0.05 to 0.5% by mass. The method according to claim 1 or 2, including, preferably comprising, these.

9. The method according to claim 1 or 2, wherein in step 1), a solvent-based composition is applied such that a dry film thickness of less than 1.0 μm, preferably less than 900 nm or less than 800 nm, more preferably less than 700 nm or less than 600 nm, more preferably less than 500 nm or less than 400 nm, and most preferably less than 300 nm or less than 200 nm is obtained after carrying out any step 2).

10. The method according to claim 1 or 2, wherein component B) of the sealing system used to prepare the sealant composition used in step 3) comprises at least one component B0), wherein component B0) is selected from a component comprising two or more epoxide groups (component B1)), a component being a metal oxide and / or metal peroxide, particularly manganese dioxide (component B2)), a component being an organic peroxide (component B3)), a component comprising two or more vinyl groups (component B4)), and mixtures thereof, preferably selected from the group consisting of a component comprising two or more epoxide groups (component B1)), a component being a metal oxide and / or metal peroxide, particularly manganese dioxide (component B2)), and mixtures thereof, and more preferably, component B1) represents at least one component comprising two or more epoxide groups, or component B2) represents at least one metal oxide and / or metal peroxide, particularly manganese dioxide.

11. The method according to claim 1 or 2, wherein the optionally pre-coated substrate is selected from metal substrates, and the metal is preferably selected from steel, steel alloys, aluminum, aluminum alloys, titanium, titanium alloys, and mixtures thereof, or the optionally pre-coated substrate is selected from thermoplastic substrates including glass substrates, polycarbonate and polyalkyl (meth)acrylic substrates, and fiber-reinforced composite substrates, and in any case the substrate optionally has at least one coating layer, most preferably the optionally pre-coated substrate is selected from metal substrates and the substrate optionally has at least one coating layer.

12. A sealed substrate that can be obtained by the method of claim 1 or 2, preferably suitable for use in aircraft and / or the aerospace industry.

13. A method for using a solvent-type composition as defined in claim 1 or 2 as an adhesion-promoting composition to improve adhesion between the surface of an optionally pre-coated substrate and a subsequently applied sealant film, wherein the sealant film is preferably obtained by applying a sealant composition obtained by mixing components A) and B) of at least two separately existing sealing systems to a film already present on the surface of an optionally pre-coated substrate, wherein component A) of the sealing system is selected from polyethers, polythioethers, polysulfides, polythioether-sulfide components and mixtures thereof. A method of use comprising, at least one polymer component A1) comprising two or more thiol groups, and at least one polymer component A1) comprising two or more thiol groups selected from polyethers, polythioethers, polysulfides, polythioether-sulfide components and mixtures thereof, wherein component B) of the sealing system comprises at least one component B0) suitable for curing the sealant composition by at least partially inducing the chemical conversion of two or more thiol groups of component A1), and the film is formed by at least partially applying the solvent-type composition to the surface according to claim 1 or 2.

14. A solvent-type composition as defined in claim 1 or 2.

15. at least, A sealing system as defined in claim 1, 10, or 13, comprising at least two components A) and B) separated from each other, and Solvent-type composition as defined in claim 1 or as described in claim 14 A kit of parts that includes the parts separated from each other.

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