Fast-curing two-component silicone composition with longer mixer open time

Abstract

The present invention relates to a two-component silicone composition comprising: Ingredient (A) contains: at least one hydroxyl-terminated polydiorganosiloxane (P); preferably at least one filler; between 0.05 and 5.0 weight percent emulsion water, based on component (A); and Ingredient (B) contains: at least one non-condensing polydiorganosiloxane (W) as a plasticizer, at least one organosilane (V) as a crosslinker, at least one catalyst (K) for crosslinking the polydiorganosiloxane; where: All organosilanes (V) preferably have the same hydrolyzable alkoxysilane group, preferably methoxysilane group; and The catalyst (K) is a tin complex having two mercaptide ligands of formula (V), and the ligand (L 1 ) are independently linked via sulfur, especially alkyl mercaptides of C6-C 16 alkyl mercaptide, wherein the ligand (L 1 ) may have a methyldialkoxysilane group, preferably a methyldimethoxysilane group, and the ligand (L 2 ) are independently alkyl ligands, in particular C6-C 14 is an alkyl ligand; and The composition of the present invention is characterized in that component (B) contains less than 5% by weight of carbon black, based on component (B). The composition of the present invention has a very long pot life and mixer open time, and at the same time has extremely fast curing and excellent storage stability. JPEG2023551402000027.jpg21160

Description

[Technical Field]

[0001] This invention relates to the field of two-component silicone compositions. [Background technology]

[0002] Two-component silicone compositions have been known for some time and are used in various applications, particularly as adhesives and sealants. Widely used products are two-component silicone compositions, which are crosslinked at room temperature and are known as RTV-2 silicones (RTV-2: "room temperature vulcanizing, 2-part silicones").

[0003] Such two-component silicone compositions are described, for example, in European Patent Application Publication No. 0 787 766A1. To prevent a decrease in the storage stability of the compositions described therein, i.e., to prevent premature and undesirable curing, the main component, namely α,ω-dihydroxypolydiorganosiloxane, and the catalyst and crosslinking agent for crosslinking the polydiorganosiloxane are stored in the form of two separate components. In the application of such compositions, these two components are then mixed together in the desired weight or volume ratio, the ratio being important for crosslinking and curing the composition. The time during which the mixture can be processed and applied before premature curing occurs is called the pot life or open time.

[0004] The primary drawback of two-component silicone compositions, such as those described in European Patent Application Publication No. 0 787 766A1, is the interdependence between pot life and curing speed. These properties depend on the formulation of the two-component silicone composition, particularly the type and amount of reactive substances present, such as crosslinking agents, and the amount of catalyst. Typically, it is possible to achieve two-component silicone compositions with either a short pot life and fast curing, or a long pot life and slow curing. Both of these compositions also possess typical curing characteristics with crosslinking, which are either slow or fast but constant from the start, and therefore, viscosity increases after mixing the multiple components. This is particularly problematic in industrial manufacturing. In such cases, a desirable pot life is one that is arbitrary, with no waiting time, but with extremely rapid curing after application, allowing the manufactured components to be quickly transferred to the next process. Another problem with extremely short pot lives is that the mixture begins to cure too quickly, resulting in defective products and undesirable cleaning operations. If the pot life is excessively long and curing is slow afterward, the manufacturing cycle becomes longer due to the waiting time, which is also undesirable. Therefore, the ideal two-component silicone composition has a long pot life but cures very quickly. However, achieving this is extremely difficult.

[0005] Another major drawback of fast-curing two-component silicone compositions is known as the open time problem. This mainly occurs when mixing the two components using a static mixer. What happens is that when the two components enter the static mixer and collide with each other, the relative concentration of the catalyst component to the polydiorganosiloxane component can become locally excessive. As a result, the composition hardens rapidly inside the static mixer, which can cause the mixer to clog or significantly shorten the pot life during or after application. This is particularly problematic when the polydiorganosiloxane component is used in a weight ratio of (≧1:1) to the catalyst component (which is common in practice).

[0006] Possible solutions to this drawback include, for example, actually reducing the catalyst content or further diluting the catalyst, thereby lowering the catalyst concentration within the catalyst-containing components. However, reducing the catalyst content inevitably increases the curing time, i.e., the pot life, which is generally undesirable. On the other hand, increasing the dilution of the catalyst means that additional diluents must be used, or that unreactive components must be transferred from the polydiorganosiloxane-containing components to the catalyst-containing components, which can lead to reduced processability and / or a decrease in the mechanical properties of the cured composition, and furthermore, limits the configurational options of the composition. [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, there is a need for a two-component silicone composition that has a long pot life and, at the same time, a long mixer open time, that is less susceptible to the undesirable mixing phenomena described above, but that hardens very quickly after the pot life ends, allowing the components manufactured using the composition to move on to the next process as quickly as possible. [Means for solving the problem]

[0008] Therefore, the object of the present invention is to overcome the shortcomings of the prior art and provide a two-component silicone composition that has a long mixer open time and a long pot life, regardless of the mixing ratio, and that cures extremely quickly after the end of the pot life. In addition, the composition should be formulated with a low crosslinking agent concentration, thereby resulting in a low level of VOC contamination from the alcohol leached out, exceptional storage stability, and good mechanical properties after curing.

[0009] Surprisingly, it was found that this objective could be achieved by the two-component silicone composition claimed in claim 1.

[0010] By using a specific catalyst having two thiolate ligands (which is by no means obvious to those skilled in the art), preferably in combination with a specific organosilane as a crosslinking agent, it is possible to obtain a two-component silicone composition having a long pot life and, above all, a long mixer open time, and in which the two components can be used in a broad range of mixing ratios. The two-component silicone compositions according to the present invention have a robust mixing profile, that is, they can be used in a wide range of selectable polymer-to-curing component mixing ratios. In addition, the two-component silicone compositions according to the present invention have exceptionally good storage stability, particularly with respect to the curable component including the catalyst. This results in an exceptionally low tendency for phase separation and, therefore, can be used without any restrictions, even after a long storage period. The two-component silicone compositions according to the present invention can be prepared to achieve, for example, a pot life of 25 minutes and, at the same time, allow for a mixer open time of, for example, 7-8 minutes. At the same time, the two-component silicone composition according to the present invention cures at a satisfactory rate, and in a preferred embodiment, the mixture has a pot life of up to 30 minutes while being 80% cured 4 hours after the end of application. Furthermore, the two-component silicone composition according to the present invention exhibits extremely good adhesion to various substrates.

[0011] Further aspects of the present invention are the subject of further independent claims. Particularly preferred embodiments of the present invention are the subject of dependent claims. [Modes for carrying out the invention]

[0012] The present invention is a two-component silicone composition comprising the following: Ingredient A, which includes the following: (i) at least one hydroxyl-terminated polydiorganosiloxane P; (ii) Preferably at least one filler; (iii) 0.05% to 5.0% by weight of emulsion water based on component A; and Ingredient B includes the following: (i) at least one non-condensing polydiorganosiloxane W as a plasticizer; (ii) At least one organosilane V as a crosslinking agent; (iii) At least one catalyst K for crosslinking polydiorganosiloxane; Here, All organosilane V preferably have the same hydrolyzable alkoxysilane group, preferably a methoxysilane group; and Catalyst K is a tin complex of formula (V) having two mercaptide ligands: [ka] In the formula, the ligand L 1 These are, independently, alkyl mercaptides coordinated via sulfur, particularly C6-C6. 16 It is an alkyl mercaptide, where ligand L 1 It may have a methyldialkoxysilane group, preferably a methyldimethoxysilane group, and ligand L 2 Each of these independently comprises alkyl ligands, particularly C6-C 14 It is an alkyl ligand; and Component B contains less than 5% by weight of carbon black, based on component B. Characterized by, A two-component silicone composition is provided.

[0013] In this specification, the term "silane group" refers to a silyl group bonded to an organic group or polyorganosiloxane group and having one to three, particularly two or three, hydrolyzable substituents on its silicon atom. Particularly preferred common hydrolyzable substituents are alkoxy groups. These silane groups are also called "alkoxysilane groups." The silane group may be in a partially or completely hydrolyzed form.

[0014] "Aminosilane" and "glycidoxysilane" refer to organoalkoxysilanes that have one or more amino groups or glycidoxy groups, respectively, in addition to a silane group on their organic group.

[0015] "Primary amino group" and "primary amine nitrogen" refer to an NH2 group and its nitrogen atom bonded to an organic group, respectively; "secondary amino group" and "secondary amine nitrogen" refer to an NH group and its nitrogen atom bonded to two organic groups, respectively (these may further combine to form part of a ring); and "tertiary amino group" and "tertiary amine nitrogen" refer to an N group and its nitrogen atom bonded to three organic groups, respectively (two or three of these may combine to form part of one or more rings).

[0016] The term "organic polymer" encompasses a group of macromolecules formed by polymerization reactions (polymerization, polyaddition, polycondensation), the majority of which are carbon atoms in their polymer backbone, and which are chemically homogeneous but differ in their degree of polymerization, molar mass, and chain length, as well as the reaction products of such a group of macromolecules. Polymers having a polyorganosiloxane backbone (commonly referred to as "silicones") are not organic polymers in the context of this specification.

[0017] In this specification, the term "molecular weight" should be understood to mean the molar mass (in grams / mol) of a molecule or a part of a molecule (sometimes called a "radical"). The term "average molecular weight" refers to the number average M of an oligomeric or polymeric mixture of molecules or groups. n This represents the coefficient of change, which is typically measured by gel permeation chromatography (GPC) using polystyrene as a standard.

[0018] A substance or composition is described as "storage-stable" or "storable" if, when stored at room temperature in a suitable container for an extended period, typically at least six to nine months or more, the storage does not result in any change to its applicable or usable properties, particularly viscosity and crosslinking rate, that would affect its use.

[0019] In this specification, substances whose names begin with "poly," such as polyols, refer to substances that formally contain two or more of the functional groups from which their name is derived, per molecule.

[0020] In this specification, the term “polymer” includes, firstly, an assembly of macromolecules that are chemically homogeneous but differ in their degree of polymerization, molar mass, and chain length, and which are prepared by polymerization reactions (polymerization, polyaddition, polycondensation). Secondly, the term also includes derivatives of such assemblies of macromolecules from polymerization reactions, i.e., compounds obtained by the reaction of functional groups in a given macromolecule, such as addition or substitution reactions, which may be chemically homogeneous or heterogeneous. The term further includes so-called prepolymers, i.e., reactive oligomeric initial adducts whose functional groups contribute to the formation of macromolecules.

[0021] "Pot life," or its alternative name "open time," should be understood as the window of processability of a reactive composition after its application. The end of the pot life is almost always accompanied by an increase in the viscosity of the composition, to the point where it becomes impossible to process the composition further for practical use.

[0022] The term "mixer open time" should be understood as the open time, or processing time, for a reactive composition inside a static mixer. During this time, the substance can remain in the mixer without significant changes in its processing properties and without the need to purge or extrude the reaction products in order to continue the operation.

[0023] In the formulas herein, the dotted lines represent the bond between the substituent and the associated molecular group in each case.

[0024] "Room temperature" refers to a temperature of approximately 23°C.

[0025] Unless otherwise specified, all industrial standards or specifications described herein relate to the edition of such industrial standard or specification that is in effect at the time this patent application was filed.

[0026] In this specification, "mass" and "weight" are used synonymously. Therefore, "weight percent" (weight %) is a percentage mass fraction described in relation to the total mass (weight) of the entire composition, or, depending on the context, the total mass (weight) of its molecules, unless otherwise specified.

[0027] Ingredient A The first component A of the two-component silicone composition includes at least one hydroxyl-terminated polydiorganosiloxane P, an emulsion of water in an amount between 0.05% and 5.0% by weight relative to component A, and preferably at least one filler.

[0028] Polydiorganosiloxane P Component A of the two-component silicone composition contains a hydroxyl-terminated polydiorganosiloxane P, which is in particular the polydiorganosiloxane P' of formula (IV). [ka]

[0029] In this case, the groups R 1 and R 2 each independently represent a linear or branched monovalent hydrocarbyl group having 1 to 12 carbon atoms, optionally one or more heteroatoms, and optionally one or more C-C multiple bonds and / or optionally an alicyclic and / or aromatic moiety.

[0030] Specifically, the groups R 1 and R 2 are alkyl groups having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms, preferably methyl groups.

[0031] The exponent n is selected such that the weight-average molecular weight M of the polydiorganosiloxane P, relative to polystyrene as the standard, w is 500 to 250,000 g / mol.

[0032] More specifically, the hydroxyl-terminated polydiorganosiloxane P’ is the polydiorganosiloxane P1 of formula (I) (where n is the weight-average molecular weight M of the polydiorganosiloxane P1 relative to polystyrene as the standard w is selected to be 30,000 to 80,000 g / mol, particularly 35,000 to 60,000 g / mol), or the polydiorganosiloxane P’ used is a mixture of the following, (i’) at least one hydroxyl-terminated polydiorganosiloxane P2 of formula (I) (where n is the weight-average molecular weight M of the polydiorganosiloxane P2 relative to polystyrene as the standard w is selected to be greater than 80,000 to 250,000 g / mol, particularly 90,000 to 150,000 g / mol); and (ii') At least one hydroxyl-terminated polydiorganosiloxane P3 of formula (I) (where n is the weight-average molecular weight M of polydiorganosiloxane P3 with polystyrene as the standard) w However, it is selected so that the concentration is 500 to ≤ 30,000 g / mol, particularly 500 to 25,000 g / mol, preferably 1,000 to 20,000 g / mol. Or, The polydiorganosiloxane P' used is a mixture of the following: (i) At least one hydroxyl-terminated polydiorganosiloxane P1 of formula (I) (where n is the weight-average molecular weight M of polydiorganosiloxane P1 as a standard polystyrene) w However, it is selected so that the concentration is 30,000 to 80,000 g / mol, and especially 35,000 to 60,000 g / mol); and (ii) At least one hydroxyl-terminated polydiorganosiloxane P3 of formula (I) (where n is the weight-average molecular weight M of polydiorganosiloxane P3 as a standard polystyrene) w However, the concentration is selected to be between 500 and ≤ 30,000 g / mol, particularly between 500 and 25,000 g / mol, preferably between 1,000 and 20,000 g / mol).

[0033] Hydroxyl-terminated polydiorganosiloxanes, particularly those represented by formula (I), are known and available on the market. This type of polydiorganosiloxane can also be prepared by known methods. For example, methods for their preparation are described in U.S. Patent No. 4,962,152 (which is incorporated herein by reference).

[0034] The hydroxyl-terminated polydiorganosiloxane P described above preferably has a viscosity between 1 and 500,000 mPa·s, and more particularly between 10 and 250,000 mPa·s, at 23°C.

[0035] More preferably, the polydiorganosiloxane P1 has a viscosity between 5,000 and 100,000 mPa·s, particularly between 7,500 and 50,000 mPa·s, at 23°C.

[0036] If the polydiorganosiloxane P' is a mixture of at least one hydroxyl-terminated polydiorganosiloxane P2 and at least one hydroxyl-terminated polydiorganosiloxane P3, then the polydiorganosiloxane P2 preferably has a viscosity between 100,000 and 500,000 mPa·s, particularly between 150,000 and 250,000 mPa·s, at 23°C, and the polydiorganosiloxane P3 preferably has a viscosity between 1 and 5,000 mPa·s, particularly between 10 and 2,500 mPa·s, and preferably between 20 and 1,000 mPa·s, at 23°C.

[0037] The viscosity values ​​mentioned above were measured according to DIN 53018.

[0038] It may be advantageous to use multiple different polydiorganosiloxanes P2 and / or P3 in the form of a mixture.

[0039] If the polydiorganosiloxane P' is a mixture of at least one hydroxyl-terminated polydiorganosiloxane P1 and at least one hydroxyl-terminated polydiorganosiloxane P3, then the polydiorganosiloxane P1 preferably has a viscosity between 100,000 and 500,000 mPa·s, particularly between 7,500 and 50,000 mPa·s, at 23°C, and the polydiorganosiloxane P3 preferably has a viscosity between 1 and 5,000 mPa·s, particularly between 10 and 2,500 mPa·s, and preferably between 20 and 1,000 mPa·s, at 23°C.

[0040] The viscosity values ​​mentioned above were measured according to DIN 53018.

[0041] It may be advantageous to use multiple different polydiorganosiloxanes P1 and / or P3 in the form of a mixture.

[0042] When the polydiorganosiloxane P' used is a mixture of at least one polydiorganosiloxane P2 and at least one polydiorganosiloxane P3, the weight ratio of polydiorganosiloxane P2 is generally greater than that of polydiorganosiloxane P3. However, it should be taken into consideration that each ratio depends on the molecular weight of each polydiorganosiloxane.

[0043] When the polydiorganosiloxane P' used is a mixture of at least one polydiorganosiloxane P1 and at least one polydiorganosiloxane P3, the weight ratio of polydiorganosiloxane P1 is generally greater than that of polydiorganosiloxane P3. However, it should be taken into consideration that each ratio depends on the molecular weight of each polydiorganosiloxane.

[0044] Component A preferably contains hydroxyl-terminated polydiorganosiloxane P or hydroxyl-terminated polydiorganosiloxane P' in an amount between 30% and 70% by weight, more preferably between 30% and 50% by weight, based on component A.

[0045] If the polydiorganosiloxane P' is a mixture of at least one hydroxyl-terminated polydiorganosiloxane P2 and at least one hydroxyl-terminated polydiorganosiloxane P3, it is preferable that component A contains, based on component A, an amount of hydroxyl-terminated polydiorganosiloxane P2 between 20% and 60% by weight, preferably between 30% and 50% by weight, and an amount of hydroxyl-terminated polydiorganosiloxane P3 between 1% and 15% by weight, preferably between 2% and 10% by weight, based on component A.

[0046] If the polydiorganosiloxane P' is a mixture of at least one hydroxyl-terminated polydiorganosiloxane P1 and at least one hydroxyl-terminated polydiorganosiloxane P3, it is preferable that component A contains, based on component A, an amount of hydroxyl-terminated polydiorganosiloxane P1 between 20% and 60% by weight, preferably between 30% and 50% by weight, and an amount of hydroxyl-terminated polydiorganosiloxane P3 between 0.5% and 15% by weight, preferably between 0.75% and 10% by weight, based on component A.

[0047] The described polydiorganosiloxane P may, in various embodiments, further contain a certain proportion of branched (so-called T units) supporting Si-OH groups on side chains. However, it is preferable that the polydiorganosiloxane is primarily linear and formed without Si-OH-reactive side chains. However, in the case of the described polydiorganosiloxane P2, particularly with respect to the mechanical properties of the cured composition, it may be advantageous that a portion of the polydiorganosiloxane units of the polydiorganosiloxane P2 consists of T units, preferably 0-10%, particularly 0.01%-5%, and most preferably 0.02%-1%, of the siloxane units of the polydiorganosiloxane P2. The remaining siloxane units are, in all cases, D units, i.e., strictly linear siloxane units that do not contain Si-OH groups.

[0048] water Component A of the two-component silicone composition further contains emulsion water in an amount between 0.05% and 5.0% by weight, based on component A. The water in component A contributes to the rapid and uniform curing of the mixed two-component composition and is essential for enabling the rapid and uniform curing in the present invention. The water is preferably present in an amount between 0.1% and 2.5% by weight, and more particularly between 0.1% and 1.5% by weight, based on component A.

[0049] In this case, the water is not present in a free form or as adsorbed water (for example, on a filler), but rather mixed as an emulsion (for example, in a silicone oil). This allows for more uniform mixing of the mixed composition at low concentration gradients and more uniform curing after application. For example, a water / oil emulsion containing 40% to 60% by weight of water has been found to be advantageous.

[0050] Component A of the two-component silicone composition may further contain additional additives, such as fillers, plasticizers, pigments, and compounding additives, such as dispersing additives or thixotropes. Such additives are known to those skilled in the art of silicone formulations. These additives can improve the processability and miscibility of component A and / or the mixed two-component silicone composition. However, they are not essential for the effects of the present invention.

[0051] Component B The second component B of the two-component silicone composition includes the following: (i) at least one non-condensing polydiorganosiloxane as a plasticizer W; (ii) At least one organosilane V as a crosslinking agent; (iii) At least one catalyst K for crosslinking polydiorganosiloxane; Here, All organosilane V preferably have the same hydrolyzable alkoxysilane group, preferably a methoxysilane group; and Catalyst K is a tin complex of the following formula (V) having two mercaptide ligands: [ka] In the formula, the ligand L 1 These are, independently, alkyl mercaptides coordinated via sulfur, particularly C6-C6. 16 It is an alkyl mercaptide, where ligand L 1It may have a methyldialkoxysilane group, preferably a methyldimethoxysilane group, and ligand L 2 Each of these independently comprises alkyl ligands, particularly C6-C 14 It is an alkyl ligand; and Component B contains less than 5% by weight of carbon black, based on component B. It is characterized by the following.

[0052] Plasticizer W Component B, and preferably further component A, contains at least one non-condensable polydiorganosiloxane as a plasticizer W. This is typically a polydiorganosiloxane whose terminal groups are capped with alkyl or vinyl groups, so that the polydiorganosiloxane cannot participate in any condensation or crosslinking reaction.

[0053] Particularly preferred plasticizers W are trialkylsilyl-terminated polydialkylsiloxanes, in particular trimethylsilyl-terminated polydimethylsiloxanes, as previously described herein. However, it is also possible to use trimethylsilyl-terminated polydimethylsiloxanes in which some of the methyl groups are substituted with other organic groups, such as phenyl, vinyl, or trifluoropropyl. While linear trimethylsilyl-terminated polydimethylsiloxanes are particularly preferred, branched compounds are also possible. Such branched compounds can be obtained by using a small amount of trifunctional or tetrafunctional silane in their starting materials during preparation. In place of polysiloxane plasticizers, other organic compounds, such as certain hydrocarbons, hydroxyl-free polyethers, or mixtures thereof, can also be used as plasticizer W. These types of hydrocarbons may be aromatic or aliphatic. Particular care should be taken in selection to ensure that the hydrocarbons have low volatility and good compatibility with other components of the silicone composition.

[0054] A preferred plasticizer W is polydimethylsiloxane having a viscosity between 1 and 200,000 mPa·s. Particularly preferred is a viscosity between 10 and 150,000 mPa·s.

[0055] In component A, it is particularly advantageous and preferable to use a trialkylsilyl-terminated polydimethylsiloxane as the plasticizer W, having a viscosity between 1 and 10,000 mPa·s, preferably between 10 and 1,000 mPa·s. This allows for the setting of a viscosity particularly advantageous for component A, thereby facilitating mixing.

[0056] In addition, it is particularly advantageous and preferable to use a trialkylsilyl-terminated polydimethylsiloxane having a viscosity between 10,000 and 200,000 mPa·s, preferably between 20,000 and 150,000 mPa·s, as the plasticizer W in component B. This makes it possible to achieve particularly good storage stability and particularly low phase separation tendency in component B.

[0057] Such plasticizers W are well known to those skilled in the art of silicone formulations, and are sold, for example, by Wacker Chemie (Germany) under the Wacker® AK trade name series, which will be described in more detail below. These non-reactive polydiorganosiloxanes are also called silicone oils. They can be obtained in various chain lengths and therefore viscosities, and their primary purpose is to create fillers that are easily mixed and homogenized with solid components, such as other components, and that improve the mechanical properties and fluidity of the composition.

[0058] It is preferable that component B contains a plasticizer W in an amount between 30% and 50% by weight.

[0059] It is preferable that component A contains a plasticizer W in an amount between 1% and 15% by weight. Component A may require less plasticizer W, or even none at all, because it already contains a liquid hydroxyl-terminated polydiorganosiloxane.

[0060] For example, it may be advantageous to combine various types of plasticizers W that have different viscosities or different end groups.

[0061] It is preferable that component B contains at least one plasticizer W having a vinylsilane-terminated group or a methylsilane-terminated group.

[0062] Catalyst K Component B of the two-component silicone composition further contains at least one catalyst K for crosslinking polydiorganosiloxane.

[0063] Catalyst K has two mercaptide ligands, formula (V): [ka] (In the formula, the ligand L 1 These are, independently, alkyl mercaptides coordinated via sulfur, particularly C6-C6. 16 Alkyl mercaptide, preferably C8-C 14 Alkyl mercaptide, most preferably C 10 ~C 12 It is an alkyl mercaptide, but here, ligand L 1 However, it may also have a methyldialkoxysilane group, preferably a methyldimethoxysilane group, and ligand L 2 These are, independently, C3~C 18 Alkyl ligands, especially C6-C 14 Alkyl ligand, preferably C6-C 12 It is a tin complex (with an alkyl ligand).

[0064] Therefore, catalyst K consists of two C3~C 18 Alkyl ligand L2 , especially two C6~C 14 Alkyl ligand L 2 It is an Sn(IV) complex containing [a specific compound].

[0065] Since it has been found that extremely short alkyl ligands, such as methyl ligands, contribute to the poor storage stability of component B, ligand L 2 That is inappropriate.

[0066] Ligand L 2 Preferably C6~C 14 Alkyl ligands, particularly phenyl, hexyl, octyl, or dodecyl ligands, most preferably octyl ligands, are used. They have particularly high storage stability and form complexes with particularly good activity in the composition in the present invention.

[0067] In addition, catalyst K has two mercaptide ligands L coordinated via sulfur atoms. 1 , especially C6~C 16 It has an alkyl mercaptide, where ligand L 1 In some cases, it has a methyldialkoxysilane group, preferably a methyldimethoxysilane group. The term "mercaptide" is used synonymously with the term "thiolate," and refers to deprotonated RS. - It is described as a ligand (where R is an organic group).

[0068] Those two ligands L 1 However, it was found that it is not possible to construct a single bidentate ligand having two thiolate groups, because its chelating effect may reduce the effect according to the present invention. Therefore, ligand L 1 It must consist of two individually coordinated alkyl mercaptide ligands. Preferably, these ligands do not contain any other heteroatoms that can coordinate to tin, such as amino or carboxylate groups. Ligand L 1 However, apart from the methyldialkoxysilane group, it is preferable that the product does not contain any functional groups having heteroatoms.

[0069] On the other hand, methyldialkoxysilane groups, particularly methyldimethoxysilane groups, can be advantageous because they can be incorporated into the polymer backbone, thereby limiting the mobility of sulfur ligands. This also has the advantage of preventing undesirable migration effects and / or various types of yellowing. However, if methylalkoxysilane groups are present, it is preferable that the crosslinking agent V has the same alkoxysilane group.

[0070] Furthermore, ligand L having a trialkoxysilane group 1 However, these were found to be unsuitable because they reduced the effectiveness of the catalyst and the storage stability of the composition.

[0071] Ligand L 1 Preferably, the ligand is a dodecylthiolate ligand, an octadecylthiolate ligand, or a 3-mercaptopropylmethyldimethoxysilane ligand coordinated via a sulfur atom.

[0072] Dodecylthiolate ligands are particularly preferred. They provide catalyst K, which is especially effective and has high storage stability. Dodecylthio ligands have almost no odor compared to ligands with shorter alkyl chains, yet they are still liquid at room temperature, and therefore have the further advantage of being easier to handle compared to ligands with longer alkyl chains.

[0073] Particularly preferred is a 3-mercaptopropylmethyldimethoxysilane ligand that is further coordinated via a sulfur atom.

[0074] These catalysts provide particularly effective catalyst K, and exhibit a particularly low tendency for yellowing in the cured composition.

[0075] In a particularly preferred embodiment of catalyst K, the ligand L in formula (V) is 1Both are dodecyl mercaptides, and ligand L 2 Both are octill.

[0076] A further particularly preferred embodiment of catalyst K is that, in formula (V), ligand L 1 Both are 3-mercaptopropylmethyldimethoxysilane, and ligand L 2 Both are octill.

[0077] Catalyst K can be easily prepared, for example, by stirring a dialkyltin diacetate with a suitable mercaptan ligand in a molar ratio of approximately (2:1) (ligand:tin complex) at 23°C for 24 hours, excluding air. In this process, by-products generated by ligand exchange, such as acetic acid, can be advantageously removed, for example, by distillation under reduced pressure.

[0078] Needless to say, it is also possible, and in some cases preferable, to use mixtures of various catalysts.

[0079] The ratio of catalyst K for crosslinking the polydiorganosiloxane is preferably 0.05% to 10% by weight, particularly 0.1% to 5% by weight, and preferably 0.25% to 4% by weight, based on component B of the two-component silicone composition.

[0080] The amount of catalyst K affects the pot life and its range, which can be observed in the mixed two-component composition. A higher catalyst content will result in a shorter pot life, followed by faster curing. However, these effects are also strongly influenced by the choice of crosslinking agent. This will be explained in more detail below.

[0081] Component B of the two-component silicone composition further includes at least one crosslinking agent, preferably two or more different crosslinking agents, for the silicone composition. In this case, the crosslinking agent refers to an organosilicon compound having a hydrolyzable alkoxysilane group. In this invention, three different types of crosslinking agents V1, V2, and V3 are distinguished, and these will be described in more detail below.

[0082] For the effects of the present invention, it is advantageous and preferable that all crosslinking agents in the composition support the same alkoxysilane group. For example, all crosslinking agents may have a methoxysilane group, or all crosslinking agents may have an ethoxysilane group. A mixture of different alkoxysilane groups is generally unfavorable and may hinder or even interfere with the effects of the present invention.

[0083] However, it is entirely possible to use a mixture of crosslinking agents having methoxy groups and crosslinking agents having ethoxy groups. For example, if the crosslinking agent V that hydrolyzes the slowest has ethoxysilane groups rather than methoxysilane groups or other types, then the faster crosslinking agents V will have methoxysilane groups. Similarly, when using a mixture of multiple crosslinking agents V, the crosslinking agents constituting a very small portion of the mixture may have alkoxysilane groups, unlike the remaining crosslinking agents, but in that case they should be of the same type with respect to alkoxysilane groups. The effects of the present invention are not diminished even in such mixtures.

[0084] Crosslinking agent V1 Component B of the composition of the present invention contains at least one first organosilane V1 of formula (I) in an amount between 0% and 50% by weight, based on component B: [ka] (In the formula, R aThis is a hydrogen atom or a monovalent linear or branched alkyl group having 1 to 6 carbon atoms. R b (This refers to a divalent, linear or branched alkyl or alkenyl group having 2 to 20 carbon atoms.)

[0085] R a However, it is preferable that it be a hydrogen atom or a methyl group or an ethyl group. a However, it is most preferable that it be a hydrogen atom or a methyl group.

[0086] R a Silane V1 containing ethyl groups that are converted to hydrogen atoms after hydrolysis is particularly advantageous because, firstly, they allow for particularly good controllability of pot life, yet they cure extremely rapidly, and in addition, they do not release toxic methanol.

[0087] R a Silane V1 containing methyl groups that are converted to hydrogen atoms after hydrolysis is particularly advantageous because, while they harden particularly rapidly after the end of the pot life, they nevertheless allow for a long pot life and a long mixer open time.

[0088] R b However, it is preferable that the group is a linear alkyl or alkenyl group having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms, most preferably an ethyl group, a propyl group, an ethylene group, or a propenyl group.

[0089] Organosilane V1 is not absolutely necessary for the effects of the present invention, but when combined with organosilane V2, it enables better regulation of pot life when present in the formulation. By using organosilane V1, it is possible to extend the maximum possible pot life of the composition, but without it, the curing rate after the end of the pot life becomes significantly slower.

[0090] A preferred embodiment of the composition of the present invention includes organosilane V1 in an amount between 10% and 30% by weight, preferably between 12% and 20% by weight, based on component B.

[0091] Crosslinking agent V2 Component B of the composition of the present invention contains at least one second organosilane V2 of formula (II) in an amount between 2% by weight and 60% by weight, based on component B: [ka] (In the formula, R a This is defined in organosilane V1, and R c (This is a divalent linear or branched alkyl group having 2 to 20 carbon atoms and containing at least one secondary amino group, and optionally a hydroxyl group and an ether oxygen.)

[0092] It is preferable that organosilane V2 has the structure described by formula (IIa): [ka] (In the formula, R d This is a divalent linear or branched alkyl group having 2 to 10 carbon atoms and possibly containing a hydroxyl group and an ether oxygen, and R e (A divalent linear or branched alkyl group has 2 to 10 carbon atoms and may contain a secondary amino group.)

[0093] A preferred embodiment of the composition of the present invention includes organosilane V2 in an amount between 5% and 50% by weight, preferably between 10% and 45% by weight, based on component B.

[0094] In one preferred embodiment, the organosilane V2 contains the group R in formula (IIa). d and R e However, both are organosilane V2a, which are divalent linear or branched alkyl groups having 2 to 10 carbon atoms, particularly propyl groups.

[0095] In another particularly preferred embodiment, the organosilane V2 is composed of the group R in formula (IIa). e However, in some cases, it is a divalent linear or branched alkyl group having 2 to 10 carbon atoms containing a secondary amino group, particularly a propyl group or a C5 alkyl group having a secondary amino group in its carbon chain, and the group R d However, organosilane V2b contains a divalent linear or branched alkyl group having 2 to 10 carbon atoms, particularly a propyl group, and further contains one of the two structural elements shown in formula (IIb). In this case, the NH group in formula (IIb) is the same as the NH group in formula (IIa), and the dotted line at the oxygen atom represents the bond to the divalent linear or branched alkyl group having 2 to 10 carbon atoms, particularly the propyl group. [ka]

[0096] Organosilane V2a is available on the market, for example, under the trade names (Evonik) Dynasylan® 1122 and Dynasylan® 1124. Dynasylan® 1124 is a bis(trimethoxysilylpropyl)amine, and Dynasylan® 1122 is a bis(trimethoxysilylpropyl)amine.

[0097] Organosilane V2b can be readily prepared from commercially available organosilanes, for example, by reacting equimolar amounts of 3-aminopropyltriethoxysilane with 3-glycidoxypropyltriethoxysilane in the absence of water until the epoxy groups are completely reacted.

[0098] In a particularly preferred embodiment of organosilane V2b, the group R in formula (IIa) is present. e However, it is a divalent C5 alkyl group having a secondary amino group in its carbon chain, and the group R d However, it is a linear divalent C6 alkyl group that has an ether oxygen in its carbon chain and also a hydroxyl group. Preferably, this has a methoxysilane group as the alkoxysilane group. Such organosilanes can be prepared, for example, by reacting equimolar amounts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (e.g., Geniosil® GF91, Wacker) with 3-glycidoxypropyltrimethoxysilane (e.g., Geniosil® GF80, Wacker) in the absence of water until the epoxy group has completely reacted.

[0099] In a preferred embodiment of the composition according to the present invention, organosilane V2 comprises organosilane V2a as described above, with organosilane V2a present in an amount between 5% and 20% by weight based on component B, and in addition, organosilane V2 comprises organosilane V2b as described above, with organosilane V2b present in an amount between 5% and 20% by weight based on component B, and the composition further contains at least one organosilane V3 in an amount between 2.5% and 20% by weight based on component B, and catalyst K is present in component B in an amount between 0.1% and 1.5% by weight based on component B.

[0100] This embodiment allows for a particularly suitable, sufficiently long pot life and mixer open time, particularly rapid curing after the end of the pot life, and particularly good storage stability, especially in the case of component B.

[0101] In preferred embodiments of the composition of the present invention, a mixture of organosilane V2a and organosilane V2b is used as organosilane V2. In these embodiments, the content of catalyst K is preferably between 0.1% and 2% by weight, and particularly between 0.2% and 1% by weight, based on component B. This allows for extremely precise controllability, user-friendliness, a shorter-than-average pot life, and extremely rapid curing, which is particularly suitable for automated applications by machines with short cycle times, and even more so for a freely selectable pot life by changing the mixing ratio of components A and B. This is particularly advantageous for flexible or complex applications where it is desirable that the final performance of the cured composition always be the same, even when the pot life is varied.

[0102] In this embodiment, it is preferable to use organosilane V2a and V2b in a weight ratio between (1:2) and (2:1).

[0103] A preferred embodiment of this embodiment of the composition of the present invention includes organosilane V2a in an amount between 5% and 25% by weight, preferably 7.5% and 22.5% by weight, based on component B, and organosilane V2b in an amount between 0% and 25% by weight, preferably 5% and 22.5% by weight, based on component B.

[0104] Crosslinking agent V3 Component B of the two-component silicone composition preferably further contains hydrolyzable alkoxysilane groups (Si-OR) not covered by formulas (I) and (II) in an amount between 0% and 25% by weight relative to component B. a Further organosilane V3s are included. These also serve similarly as crosslinking agents, but are optional components.

[0105] The additional organosilane V3 is, in particular, the silane of formula (III). [ka]

[0106] In this case, base R 3 Each is independently a linear or branched monovalent hydrocarbyl group having 1 to 12 carbon atoms, possibly one or more heteroatoms, possibly one or more CC multiple bonds, and / or possibly alicyclic and / or aromatic components.

[0107] base R 4 This is the base R, which was further explained earlier in this specification. a That is the case.

[0108] The exponent p has values ​​from 0 to 4, however, if p has a value of 3 or 4, there are at least (p-2) bases R 3 Each of these groups is reactive with the hydroxyl group of polydiorganosiloxane P, and in particular has at least one condensable group, i.e., a hydroxyl group. In particular, p has a value of 0, 1, or 2, preferably 0.

[0109] The various requirements for two-component silicone compositions for selecting a silane of formula (III) as a crosslinking agent for polydiorganosiloxanes can be stringent. Not only does the reactivity of the silane play a crucial role, but toxic considerations can also be critical in the selection of the crosslinking agent.

[0110] Suitable examples of silanes of formula (III) include: methyltrimethoxysilane, chloromethyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, octyltrimethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, methyltripropoxysilane, phenyltripropoxysilane, octyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, or tetra-n-butoxysilane.

[0111] More preferably, the silane of formula (III) is methyltrimethoxysilane, dimethyltrimethoxysilane, or tetramethoxysilane, or a mixture thereof, and most preferably, methyltrimethoxysilane, octyltrimethoxysilane, or a mixture thereof.

[0112] Vinyltrimethoxysilane or vinyltriethoxysilane had been found to be unsuitable as crosslinking agents because the vinyl group has an extremely strong adverse effect on storage stability.

[0113] By using a mixture of methyltrimethoxysilane and octyltrimethoxysilane as crosslinking agent V3, the pot life and mixer open time of the silicone composition according to the present invention can be adjusted, and the more octyltrimethoxysilane used, the longer the pot life and mixer open time become.

[0114] In addition, the silane present in component B is further partially (of all R) 4 (some of which is H) or entirely (all of R) 4 The silane may already be present in a hydrolyzed form (where H is present). The fact that partially or fully hydrolyzed silanes are particularly highly reactive means that it may be advantageous to use them as crosslinking agents. Here, those skilled in the art will notice that the use of partially or fully hydrolyzed silanes results in the formation of oligomeric siloxanes, particularly dimers and / or trimers, formed by the condensation of the hydrolyzed silanes. Therefore, the crosslinking agent used for a two-component silicone composition may be an oligomeric siloxane.

[0115] Suitable examples of oligomeric siloxanes include: hexamethoxydisiloxane, hexaethoxydisiloxane, hexa-n-propoxydisiloxane, hexa-n-butoxydisiloxane, octamethoxytrisiloxane, octaethoxytrisiloxane, octa-n-butoxytrisiloxane, decamethoxytetrasiloxane, and decaethoxytetrasiloxane.

[0116] The crosslinking agent used for the two-component silicone composition may, needless to say, be any desired mixture of the silanes mentioned above.

[0117] The ratio of organosilane V3 is preferably 0.1% to 25% by weight, particularly 0.5% to 20% by weight, and preferably 1% to 15% by weight, based on component B of the two-component silicone composition.

[0118] The two-component silicone composition may, in some cases, contain further components in one or both of components A and B.

[0119] Such additional components include, in particular, the plasticizer W described above, which is an essential component in component B; inorganic and / or organic fillers; curing accelerators; pigments; adhesion accelerators; processing aids; rheology modifiers; stabilizers; dyes; inhibitors; heat stabilizers; antistatic agents; flame retardants; insecticides; waxes; leveling agents; thixotropes; and further standard raw materials, as well as additives known to those skilled in the art.

[0120] When using such optional components, it is important to ensure that components that could impair the storage stability of the composition by reacting with or with other components are stored separately.

[0121] In addition, when selecting the various components mentioned above to be included in the two-component silicone composition, it is advantageous that the presence of such components does not adversely affect the storage stability of the two components of the two-component silicone composition; in other words, that the performance of the composition, particularly its application performance and curing performance, remains largely unchanged or completely unchanged during storage. This means that the components that cause the chemical curing of the two-component silicone composition described above do not develop to a significant extent during storage. Therefore, it is particularly advantageous that the components described above do not contain or release water, or at most trace amounts of water, during storage. Accordingly, it is recommended that certain components be chemically or physically dried before being mixed into the composition.

[0122] Preferably, the composition further contains one or both of components A and B, and especially component A, at least one type of filler. The filler affects both the rheological properties of the uncured composition and the mechanical and surface properties of the cured composition. In the two-component silicone composition, either active or passive fillers can be used. In the case of active fillers, chemical or physical interactions with the polymer occur, while in the case of passive fillers, these occur only slightly or not at all.

[0123] Suitable fillers are inorganic and organic fillers, including, for example: natural, ground or precipitated calcium carbonate, calcined kaolin, aluminum oxide, aluminum hydroxide, silica, particularly finely ground silica from a pyrolysis process, carbon black, particularly industrially produced carbon black (these, however, can only be used in limited amounts in component B), aluminum silicate, magnesium aluminum silicate, zirconium silicate, quartz powder, cristobalite powder, diatomaceous earth, mica, iron oxide, titanium oxide, zirconium oxide, gypsum, annaline, barium sulfate (BaSO4, also called barite or barite), boron carbide, boron nitride, graphite, carbon fiber, glass fiber or hollow glass beads, which may have their surfaces treated with a hydrophobic agent. Preferred fillers include: calcium carbonate, calcined kaolin, carbon black, pulverized silica, and flame retardant fillers such as hydroxides or hydrates, particularly aluminum hydroxide or hydrate, preferably aluminum hydroxide.

[0124] In one preferred embodiment, the silicone composition includes, as a filler, pulverized silica or precipitated and / or ground calcium carbonate from a thermal decomposition process, particularly having a hydrophobic coating.

[0125] Component A preferably contains at least one filler, particularly precipitated and / or ground calcium carbonate, preferably hydrophobic coated calcium carbonate.

[0126] It is preferable that component B contains finely powdered silica from a thermal decomposition process. Component B must contain less than 5% by weight of carbon black based on component B. It is preferable that component B does not contain carbon black. Carbon black interferes with the effects of catalyst K in this invention.

[0127] Using a mixture of multiple fillers is entirely possible, and even advantageous.

[0128] The preferred amount of filler is, for example, 10% to 70% by weight, particularly 15% to 60% by weight, and preferably 30% to 60% by weight, based on the entire two-component silicone composition.

[0129] Particularly preferred adhesion promoters are alkoxysilanes, preferably substituted with a functional group. The functional group is, for example, an aminopropyl group, a glycidoxypropyl group, or a mercaptopropyl group. An amino functional group is preferred. Some of these adhesion promoters already fall under the definition of crosslinking agent V3 and therefore must be taken into consideration in this regard. The alkoxy group of such silanes is usually a methoxy group or an ethoxy group. Particularly preferred are aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, and 3-mercaptopropyltriethoxysilane. It is also possible to use mixtures of multiple adhesion promoters. Further examples of suitable adhesion promoters include: amino-functional alkylsilsesquioxanes, such as amino-functional methylsilsesquioxane or amino-functional propylsilsesquioxane; alkoxylated alkyleneamines, particularly ethoxylated and / or propoxylated alkylenediamines; and, moreover, oligomers, polymers, or copolymers based on polyalkylene glycols, particularly substituted ones.

[0130] However, this is in accordance with the proviso that the composition contains 10 mol% of organosilane having an epoxy group or a glycidoxy group, based on the amount of organosilane V2. Preferably, the composition contains less than 5 mol%, and especially less than 1 mol%, of organosilane having an epoxy group, based on the amount of organosilane V2. If the amount of organosilane having an epoxy group exceeds these ranges, the effects of the present invention will be significantly hindered, and the composition may no longer cure properly.

[0131] It is obvious to those skilled in the art that when silanes are used as adhesion promoters for these purposes, they can be partially or completely hydrolyzed depending on the conditions, such as humidity. Those skilled in the art have also noticed that the presence of such partially or completely hydrolyzed silanes makes it possible to induce condensation reactions that result in the formation of oligomeric siloxanes, particularly dimers and / or trimers.

[0132] Preferably, the proportion of the adhesion promoter, which does not fall under the definition of crosslinking agent V3 or V2b, is preferably 0.1% to 15% by weight, particularly 1% to 10% by weight, and preferably 1% to 5% by weight of the entire two-component silicone composition. However, in preferred embodiments, particularly when organosilane V2 and / or crosslinking agent V3 which may have an adhesion promoter effect are used, it is preferable that the composition does not contain any further adhesion promoters.

[0133] It is well known to those skilled in the art that components, such as those described in particular, do not necessarily possess only one single function or effect. Rather, it is common for a single component or compound to have two or more functions. For example, some adhesion promoters may also be crosslinking agents, or fillers may simultaneously be rheological modifiers. For instance, good adhesion-promoting effects are exhibited to some extent by organosilane V2 or V2b, and similarly by certain crosslinking agents V3.

[0134] Particularly preferred embodiments of component A of the silicone composition of the present invention include the following: Based on component A, at least one hydroxyl-terminated polydiorganosiloxane P described above, in an amount between 25% and 60% by weight, preferably between 30% and 50% by weight; Emulsion water in an amount between 0.05% and 5.0% by weight, preferably between 0.1% and 2% by weight, based on component A; and In some cases, plasticizers W, fillers, compounding additives, pigments, and further additives as described above.

[0135] A particularly preferred embodiment of this embodiment includes, as polymer P, a mixture of the following: Polymer P1 as described above, in an amount between 25% and 50% by weight, preferably between 30% and 45% by weight, based on component A; and Polymer P3 as described above, in an amount between 0% and 10% by weight, preferably between 0.5% and 5% by weight, based on component A.

[0136] Particularly preferred embodiments of component B of the silicone composition of the present invention include the following: Based on component B, catalyst K as described above is present in an amount between 0.1% and 4% by weight, preferably between 0.25% and 3% by weight; and Based on component B, 25% to 80% by weight, preferably 50% to 70% by weight, of the plasticizer W described above; and Based on component B, 0% to 25% by weight, preferably 0% to 15% by weight, of the organosilane V1 described above; and Based on component B, 5% to 25% by weight, preferably 5% to 20% by weight, of the organosilane V2a described above; and Based on component B, 0% to 25% by weight, preferably 1% to 20% by weight, of the organosilane V2b described above; and Based on component B, 0.5% to 25% by weight, preferably 1% to 20% by weight, of the organosilane V3 described above; and In some cases, fillers, compounding additives, pigments, and further additives as described above.

[0137] The two-component silicone composition of the present invention is typically stored in a package having two separate compartments. In this case, component A is present in one compartment of the package, and component B is present in the other compartment. Suitable packages include double cartridges, such as twin or coaxial cartridges, or multi-compartment tubular pouches with adapters. It is preferable to mix the two components A and B using a static mixer that can be attached to a package having two compartments.

[0138] Such preferred packages are described, for example, in U.S. Patent Application Publication No. 2006 / 0155045A1, International Publication No. 2007 / 096355A1, and U.S. Patent Application Publication No. 2003 / 0051610A1.

[0139] In industrial-scale plants, the two components A and B are typically stored separately in vats or hobocks and, when applied, are discharged and mixed by means of a gear pump, for example. In this case, the composition is preferably applied to the substrate manually or automatically by robotic means.

[0140] More specifically, the two-component silicone composition of the present invention is used such that the weight ratio of component A to component B is (≧1:1), particularly (3:1) to (15:1), and preferably (10:1) to (14:1).

[0141] The advantage of using components A and B in the preferred weight ratio described is that existing plants for dispensing and applying two-component silicone compositions in this manner are widely available, and it would be costly and inconvenient for users to remodel their plants to apply components A and B in, for example, a (1:1) weight ratio.

[0142] In the same or other preferred embodiments, the mixing ratio is controlled or set via the volumes of components A and B. This is practical and particularly advantageous in automated applications where the two components are pumped separately and fed into a static or dynamic mixer. In such cases, the mixing ratio of component A to component B by volume is preferably (≧1:1), particularly (1.5:1) to (15:1), and preferably (2:1) to (10:1).

[0143] In the case of automated pumping and mixing, in some embodiments, it is advantageous that the volume ratios of components A and B are not excessively different in order to ensure a mixture that is as homogeneous as possible. In some such embodiments, the volume ratio of component A to component B is preferably (1.1:1) to (5:1), particularly (1.5:1) to (3:1), and most preferably (1.8:1) to (2.5:1).

[0144] More preferably, component B does not contain any crosslinkable polydiorganosiloxanes. The advantage of this is that component B has better storage stability.

[0145] In particular, component B of the aforementioned two-component silicone composition is manufactured and stored in a moisture-free manner. When stored separately, the two components have high storage stability, meaning that, in a moisture-free and appropriate package or arrangement as described above, they can be stored for several months to a year or more without any changes in their usability or post-curing performance that would affect their use. Typically, their storage stability is determined by measuring their viscosity or reactivity over time.

[0146] In the application of the two-component silicone composition, components A and B are mixed together by means of a stirring method, kneading method, rolling method, etc., but especially by means of a static mixer. In this case, the hydroxyl group of the hydroxyl-terminated polydiorganosiloxane P comes into contact with the hydrolyzable group of the crosslinking agent, or various already hydrolyzed groups thereof, thereby curing the composition via a condensation reaction. In the applied state, contact of the silicone composition with water, especially contact with water present in component A containing the crosslinking agent, can similarly promote crosslinking because water reacts with the hydrolyzable group of the crosslinking agent to produce silanol groups, which have a higher reactivity compared to the hydroxyl group of the polydiorganosiloxane P. The curing of the two-component silicone composition occurs, in particular, at room temperature.

[0147] When a two-component silicone composition is crosslinked as a reaction product of that condensation reaction, specifically, the formula HO-R a (R here) a The compound (which has already been described above) is also produced. It is preferable that the by-products of these condensation reactions are compounds that do not adversely affect the composition or the substrate to which the composition is applied. Formula HO-R a It is most preferable that the reaction product is a compound that readily volatilizes from the crosslinked material or the already crosslinked composition.

[0148] The present invention further relates to a cured silicone composition which can be obtained from the above-described two-component silicone composition by mixing component A with component B.

[0149] The present invention further relates to the use of the two-component silicone composition described above as an adhesive, sealant, coating, or casting compound. It is preferable to use the composition of the present invention as an adhesive.

[0150] The two-component silicone composition of the present invention is particularly used in a method for bonding two substrates S1 and S2, which includes the following steps: (a) Applying the two-component silicone composition described above to substrate S1 and / or substrate S2; (b) During the open time of the composition, bring the substrate S1 and the substrate S2 into contact through the applied composition; (c) curing the composition by reacting components A and B; (Here, base material S1 and base material S2 may be the same or different.)

[0151] The compositions of the present invention may also be used in sealing or coating methods, which include the following steps: (a') Applying the two-component silicone composition described above between substrate S1 and / or between S1 and S2 of two substrates; (b') To cure the composition by reacting components A and B; (Here, base material S1 and base material S2 may be the same or different.)

[0152] It goes without saying that it is obvious to those skilled in the art that the two components A and B must be mixed together immediately before or during the application of the two-component composition.

[0153] Preferably, the two-component silicone composition of the present invention has a paste-like consistency with structurally viscous properties. Such a composition is preferably, and advantageously, applied to a substrate using a suitable instrument in the form of beads having a substantially circular or triangular cross-section.

[0154] The compositions of the present invention, which have good applicability, possess high creep resistance and short-threading properties. This means that after application, they remain in the applied shape, i.e., they do not flow, and after the application device is removed, they form, if any, very short threads, thereby preventing contamination of the substrate.

[0155] Suitable substrates S1 and / or S2 are, in particular, substrates selected from the group consisting of: concrete, mortar, brick, tile, ceramic, gypsum, natural stone such as granite or marble, glass, glass ceramic, metal or metal alloy such as aluminum, steel, non-ferrous metal, galvanized metal, wood, plastic such as PVC, polyethylene, polyamide, poly(meth)acrylate, polyester, epoxy resin, paint, and varnish.

[0156] The two-component silicone composition has found applications particularly in industrial products, especially in vehicles and consumer goods for everyday use, as well as in the construction sector, particularly underground and above-ground civil engineering works.

[0157] It is preferable to use the two-component silicone composition in window structures and facade structures, particularly in facade structures.

[0158] In addition, the present invention also relates to articles comprising a silicone composition as described above, which is at least partially cured, the articles being particularly building structures, industrial goods or modes of transport, and especially buildings or parts thereof.

[0159] Such items include, for illustrative purposes, houses, glass facades, windows, bathtubs, bathrooms, kitchens, roofs, bridges, tunnels, roads, automobiles, trucks, railway cars, buses, ships, mirrors, window panes, tanks, white goods, household appliances, dishwashers, washing machines, ovens, headlamps, fog lights, or solar panels.

[0160] The present invention also relates to a method for adjusting the pot life so that the mechanical properties of the two-component silicone composition described above do not change after curing, characterized in that the weight-based mixing ratio of component A to component B is arbitrarily selected such that component A to component B is in the range of (1:1) to (25:1), particularly (5:1) to (20:1), preferably (7:1) to (16:1).

[0161] By using this method, the pot life of the two-component silicone composition of the present invention can be adjusted over a wide range simply by changing the mixing ratio of its two components, A and B. After the end of the thus determined pot life, the composition cures exceptionally quickly and very uniformly. Regardless of the selected mixing ratio, the final performance of the cured composition, particularly its mechanical properties, is almost identical. This is extremely advantageous, as it allows the user to determine or change a pot life that can be flexibly and precisely adjusted simply by adjusting the mixing ratio, for example, by changing the pump output, without needing to change components A and B of the composition.

[0162] Therefore, even if process conditions change, the optimization of cycle time can be maintained without the need to change the silicone raw material.

[0163] The compositions of the present invention cure exceptionally quickly after the pot life has ended. In preferred embodiments of the silicone compositions of the present invention, the ratio of pot life to tack-free time (the time it takes for the surface of the applied silicone composition to become tack-free as a result of sufficient curing) is less than 2.5, particularly between 1.1 and 2.3, and preferably between 1.2 and 2.1. This enables extremely efficient process control because the composition cures very quickly after application, allowing the substrate to be processed or transported immediately afterward.

[0164] In contrast, conventional two-component silicone compositions typically have both an extremely long pot life and an extremely long curing time, or otherwise have extremely rapid curing and a consequently extremely short, user-unfriendly pot life. According to the present invention, the pot life can be made longer or shorter as needed, but in all cases, extremely rapid curing is possible after application. [Examples]

[0165] Examples of the work procedures are shown below, which are intended to further illustrate the described invention. Needless to say, the invention is not limited to these described examples of the work procedures.

[0166] Preparation of silicone compositions The following composition was created:

[0167] The components listed in Tables 2-5 were mixed together in a dissolver at room temperature under an inert atmosphere in the specified weight percentages, and stirred until a uniform paste was obtained that was visible to the naked eye.

[0168] Components A and B, prepared in this manner, were sealed in separate, airtight containers. For application, components A and B were mixed in the required weight ratio using a high-speed mixer (Hauschild & Co. KG, Germany).

[0169] Explanation of the test method To measure the pot life (and open time) of the composition, components A and B were first conditioned in a sealed cartridge at 23°C for 24 hours, and then mixed together by tumbling mixer in the weight ratios specified in Tables 6-9 (A:B=13:1 or A:B=3:1). A wooden spatula was then inserted into the mixture. Using the spatula, the mixture was examined at 1-minute intervals to determine whether it still maintained a paste-like consistency. The mixture was considered to have reached its pot life as soon as it began to exhibit even partially elastic behavior. Measurements were also performed using artificially aged compositions. Prior to carrying out the above test program, these were first heated in a sealed container at 70°C for 7 days, but component A and component B were heated separately in a sealed container.

[0170] Methods for measuring elongation at break and tensile strength, as well as methods for preparing test specimens necessary for these purposes, are described in ISO 527.

[0171] Measurements were performed at 23°C and 50% relative humidity on a Type IB test specimen (ISO 527-2) at a strain rate of 200 mm / min.

[0172] Preparation of crosslinking agent V2b N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (Geniosil® GF91, Wacker) was mixed with an equimolar amount of 3-glycidoxypropyltrimethoxysilane (Geniosil® GF80, Wacker) in a glass container under a nitrogen atmosphere. The container was sealed and left at 23°C for 7 days. The resulting mixture, free of detectable epoxy groups, was used as organosilane V2b without any further modification.

[0173] Source or preparation of catalysts K1-K8 K1: Fomrez (registered trademark) UL-32 (Galata Chemicals) K2:TIB KAT(registered trademark)318 (TIB Chemicals) K3: Fomrez (registered trademark) UL-22 (Galata Chemicals) K4: Fomrez (registered trademark) UL-21 (Galata Chemicals) K5: 0.012 mol of dioctyl tin diacetate (TIB KAT® 229, TIB Chemicals) was mixed with 0.025 mol of 3-mercaptopropyl methyldimethoxysilane (Gelest) in a sealed glass container under a nitrogen atmosphere at 23°C for 24 hours, and stirred. K6: 0.012 mol of dioctyl tin diacetate (TIB KAT® 229, TIB Chemicals) was mixed with 0.025 mol of 3-mercaptopropyltrimethoxysilane (Gelest) in a sealed glass container under a nitrogen atmosphere at 23°C for 24 hours, and stirred. K7: 0.012 mol of dioctyl tin diacetate (TIB KAT® 229, TIB Chemicals) was mixed with 0.025 mol of octadecyl mercaptan (Aldrich) in a sealed glass container under a nitrogen atmosphere at 23°C for 24 hours, and stirred. K8: 0.012 mol of butyltin triacetate (TIB KAT® 220, TIB Chemicals) was mixed with 0.037 mol of dodecyl mercaptan (Aldrich) in a sealed glass container under a nitrogen atmosphere at 23°C for 24 hours, and stirred.

[0174] [Table 1]

[0175] [Table 2]

[0176] [Table 3]

[0177] [Table 4]

[0178] [Table 5]

[0179] [Table 6]

[0180] [Table 7]

[0181] [Table 8]

[0182] [Table 9] This disclosure includes the following embodiments of the invention: <Aspect 1> A two-component silicone composition comprising the following: Ingredient A, which includes the following: (i) at least one hydroxyl-terminated polydiorganosiloxane P; (ii) Preferably at least one filler; (iii) Emulsion water in an amount of 0.05% to 5.0% by weight, based on component A; and Ingredient B includes the following: (i) at least one non-condensing polydiorganosiloxane W as a plasticizer; (ii) At least one organosilane V as a crosslinking agent; (iii) At least one catalyst K for crosslinking polydiorganosiloxane; Here, All of the organosilane V preferably have the same hydrolyzable alkoxysilane group, preferably a methoxysilane group; and The catalyst K is a tin complex of formula (V) having two mercaptide ligands:

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Claims

1. A two-component silicone composition comprising the following: Ingredient A includes the following: (i) at least one hydroxyl-terminated polydiorganosiloxane P; (iii) Emulsion water in silicone oil in an amount of 0.05% to 5.0% by weight, based on component A; and Ingredient B, which includes the following: (i) At least one non-condensing polydiorganosiloxane W as a plasticizer; (ii) At least one organosilane V as a crosslinking agent; (iii) At least one catalyst K for crosslinking polydiorganosiloxanes; Here, The catalyst K is a tin complex of formula (V) having two mercaptide ligands: 【Chemistry 1】 In the formula, the ligand L １ These are alkyl mercaptides coordinated via sulfur, where ligand L １ It may have a methyldialkoxysilane group, and ligand L ２ Each of them is independent of C ６ ~C １４ It is an alkyl ligand; and The aforementioned component B contains less than 5% by weight of carbon black based on component B. Characterized by, A two-component silicone composition.

2. The two-component silicone composition according to claim 1, characterized in that the hydroxyl-terminated polydiorganosiloxane P is a polydiorganosiloxane P' of the following formula (I): 【Chemistry 2】 During the ceremony, group R １ and R ２ Each is independently a linear or branched monovalent hydrocarbyl group having 1 to 12 carbon atoms and possibly containing one or more C=C bonds or C≡C bonds and / or possibly containing alicyclic and / or aromatic components; or a group in which one or more atoms of the hydrocarbyl group are replaced by one or more heteroatoms; and n is the weight-average molecular weight M of the polydiorganosiloxane P', with polystyrene as the standard. ｗ However, the concentration is selected to be between 500 and 250,000 g / mol.

3. A two-component silicone composition according to claim 2: The hydroxyl-terminated polydiorganosiloxane P' is the polydiorganosiloxane P1 of the formula (I), where n is the weight average molecular weight M of the polydiorganosiloxane P1 based on polystyrene ｗ is selected to be 30,000 to 80,000 g / mol; or The polydiorganosiloxane P' used is a mixture of the following: (i') at least one hydroxyl-terminated polydiorganosiloxane P2 of formula (I), where n is the weight-average molecular weight M of the polydiorganosiloxane P2 with polystyrene as the standard. ｗ However, it is selected so that it is greater than 80,000 g / mol and less than 250,000 g / mol; and (ii') at least one hydroxyl-terminated polydiorganosiloxane P3 of formula (I), where n is the weight-average molecular weight M of the polydiorganosiloxane P3, with polystyrene as the standard. ｗ However, it is selected such that the concentration is 500 to ≤ 30,000 g / mol; or The polydiorganosiloxane P' used is the following mixture: (i'') at least one hydroxyl-terminated polydiorganosiloxane P1 of formula (I), where n is the weight-average molecular weight M of the polydiorganosiloxane P1 with polystyrene as the standard. ｗ However, it is selected so that it is between 30,000 and 80,000 g / mol; and (ii") At least one hydroxyl-terminated polydiorganosiloxane P3 of formula (I), where n is the weight-average molecular weight M of the polydiorganosiloxane P3, with polystyrene as the standard. ｗ However, it is selected such that the concentration is between 500 and ≤ 30,000 g / mol; A two-component silicone composition.

4. The aforementioned base R １ and R ２ The two-component silicone composition according to claim 2 or 3, characterized in that it is an alkyl group having 1 to 5 carbon atoms.

5. A two-component silicone composition according to any one of claims 1 to 4, The organosilane V mentioned above is Based on component B, the above comprises at least one first organosilane V1 of the following formula (I) in an amount of 0% to 50% by weight; 【Transformation 3】 and Based on component B, it comprises at least one second organosilane V2 of the following formula (II) in an amount of 2% to 60% by weight; 【Chemistry 4】 and Based on component B, up to 25% by weight of hydrolyzable alkoxysilane groups Si-OR that do not fall under formulas (I) and (II). ａ Includes further organosilane V3 having; Here, R ａ However, it is either an ethyl group or a methyl group; R ｂ However, it is a divalent, linear or branched alkylene or alkenylene group having 2 to 20 carbon atoms, and R ｃ However, it is a group in which at least one secondary amino group is bonded to a divalent linear or branched alkylene group having 2 to 20 carbon atoms; However, the composition contains less than 10 mol% of an organosilane having an epoxy group, based on the amount of the organosilane V2. Characterized by, A two-component silicone composition.

6. A two-component silicone composition according to claim 5, characterized in that the organosilane V3 contains at least one silane of the following formula (III): 【Transformation 5】 During the ceremony, group R ３ Each is independently a linear or branched monovalent hydrocarbyl group having 1 to 12 carbon atoms and possibly containing one or more C=C bonds or C≡C bonds and / or possibly containing alicyclic and / or aromatic components; or a group in which one or more atoms of the hydrocarbyl group are replaced by one or more heteroatoms; and group R ４ is, base R ａ and p has values ​​from 0 to 3, provided that when p has a value of 3, there are at least (p-2) bases R ３ Each of these groups has at least one group that is reactive with the hydroxyl group of the polydiorganosiloxane P.

7. The two-component silicone composition according to claim 5 or 6, characterized in that the organosilane V2 comprises at least one organosilane of the following formula (IIa): 【Transformation 6】 During the ceremony, R ｄ is a divalent linear or branched alkylene group having 2 to 10 carbon atoms; or a group in which a hydroxyl group and an ether oxygen are bonded to the alkylene group, and R ｅ This is a divalent linear or branched alkylene group having 2 to 10 carbon atoms; or a group in which a secondary amino group is bonded to the alkylene group.

8. A two-component silicone composition according to claim 7, The organosilane V2 mentioned above is - The base R in formula (IIa) ｄ and R ｅ In all cases, organosilane V2a is a divalent linear or branched alkylene group having 2 to 10 carbon atoms; or - The base R in formula (IIa) ｅ However, it is a divalent linear or branched alkylene group having 2 to 10 carbon atoms; or a group in which a secondary amino group is bonded to the alkylene group, and the group R ｄ Organosilane V2b, which comprises a divalent linear or branched alkylene group having 2 to 10 carbon atoms, and further comprises one of two structural elements represented by the following formula (IIb); 【Transformation 7】 or - A mixture of the organosilane V2a and the organosilane V2b; Characterized by being one of the following: A two-component silicone composition.

9. The organosilane V2 includes the organosilane V2a, and the organosilane V2a is present in an amount of 5% to 20% by weight based on component B, and The organosilane V2 includes the organosilane V2b, and the organosilane V2b is present in an amount of 5% to 20% by weight based on component B, and At least one of the organosilanes V3 is present in an amount of 2.5% to 20% by weight based on component B, and The catalyst K is present in component B in an amount of 0.1% to 1.5% by weight, based on component B. Characterized by, The two-component silicone composition according to claim 8.

10. The group R in the organosilane V2b ｅ However, it is a group in which a secondary amino group is bonded to the carbon chain of a divalent C5 alkylene group, and the group R ｄ The two-component silicone composition according to any one of claims 7 to 9, characterized in that the group has an ether oxygen bonded to the carbon chain of a linear divalent C6 alkylene group, and a hydroxyl group bonded to the linear divalent C6 alkylene group.

11. In the catalyst K of formula (V), the ligand L １ Both are dodecyl mercaptides, and the ligand L ２ A two-component silicone composition according to any one of claims 1 to 10, characterized in that both are octyl.

12. A two-component silicone composition according to any one of claims 1 to 11, characterized in that the weight ratio of component A to component B is 5:1 to 20:

1.

13. Use of the two-component silicone composition according to any one of claims 1 to 12, as an adhesive, sealant, coating, or casting compound.

14. The use according to claim 13, characterized in that the two-component silicone composition is used in a window structure or a facade structure.

15. A cured silicone composition, characterized in that it can be obtained from the two-component silicone composition described in any one of claims 1 to 12 by mixing the aforementioned component A with the aforementioned component B.

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