Method of applying a sealant composition

Abstract

The present invention relates to a one part room temperature vulcanizable (RTV) comprising an organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups or combinations thereof, and a titanate-based or zirconate-based catalyst at a temperature of at least 40 DEG C A method of applying a silicone composition to a hot porous substrate by first applying an aqueous or solvent based binder composition to the hot porous substrate at a temperature of at least 40 DEG C to produce a continuous elastic binder film prior to applying the one part room temperature vulcanizable (RTV) silicone composition. Also provided is a thermally porous substrate coated with a cured layer of the above one part room temperature vulcanizable (RTV) silicone composition at a temperature of at least 40 DEG C. The porous substrate may be, for example, a building material such as stone, marble, brick, concrete, cement, and other cementitious substrates.

Description

[0001] The present invention relates to a method for applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups or combinations thereof and a titanate-based or zirconate-based catalyst to a hot porous substrate at a temperature of at least 40°C, the method being carried out by first applying an aqueous or solvent-based adhesive composition to the hot porous substrate at a temperature of at least 40°C to produce a continuous elastic adhesive film before applying the one-part room temperature vulcanizable (RTV) silicone composition. A hot porous substrate is also provided, the hot porous substrate being coated with a cured layer of the one-part room temperature vulcanizable (RTV) silicone composition at a temperature of at least 40°C. The porous substrate can be, for example, a building material such as stone, marble, brick, concrete, cement and other cementitious substrates.

[0002] Room temperature vulcanizable (RTV) silicone rubber compositions (hereinafter referred to as "RTV compositions") are well known. Typically, such compositions comprise -OH terminated diorganopolysiloxane polymers or alkoxy terminated polydiorganosiloxanes which may have an alkylene linkage between the terminal silicon and the secondary silicon in the polymer chain. They are typically condensation curable and therefore also contain one or more suitable crosslinking agents designed to react with -OH and / or alkoxy groups, typically but not absolutely always in combination with one or more condensation curing catalysts to crosslink the composition to form, for example, an elastomeric sealant product. As required and when desired, one or more additional ingredients, such as reinforcing fillers, non-reinforcing fillers, tackifiers, diluents (e.g., plasticizers and / or extenders), chain extenders, flame retardants, solvent resistance additives, biocides, etc., are also typically incorporated into these compositions. They may be one-part compositions or multi-part compositions, for example two-part compositions.

[0003] One-part condensation-curing silicone compositions are used to produce skin or diffusion-cured silicone elastomers for use as caulks, sealants, encapsulants and / or adhesives. They are generally designed to contain as little water / moisture as possible in the composition, i.e., they are stored in a substantially water-free form to prevent premature curing during storage prior to use. Such one-part condensation-curing silicone compositions are applied to the substrate in a layer that is typically thinner than 15 mm. If such compositions are applied in a layer thicker than 15 mm, this may generally result in uncured material in the depth of the material because moisture diffuses very slowly in very deep portions. Skin or diffusion curing (e.g., moisture / condensation) occurs by forming a cured skin at the composition / air interface after the sealant / encapsulant is applied to the substrate surface. After the surface skin is created, the cure rate depends on the rate at which moisture diffuses from the sealant / encapsulant interface with air to the inside (or core) of the layer of applied silicone composition, as well as the rate at which condensation reaction byproducts / effluent diffuse from the inside (or core) to the outside (or surface) of the material and the gradual thickening of the cured skin over time from the outside / surface to the inside / core. The primary, if not the only, source of moisture in these compositions is inorganic fillers, such as silica when present. The fillers may be rendered anhydrous prior to intermixing with the other ingredients, or water / moisture may be extracted from the mixture during the mixing process to ensure that the resulting sealant composition is substantially anhydrous.

[0004] Silicone sealant compositions having at least one Si-alkoxy bond (e.g., Si-methoxy bond in a terminal reactive silyl group) and having a polydiorganosiloxane polymeric backbone are widely used as sealants in the construction industry because of their good adhesion and weatherability and room temperature curing properties. The construction industry prefers one-component compositions that eliminate the need to mix the components prior to application and compositions with excellent processability.

[0005] In general, one-part room temperature vulcanizable (RTV) silicone compositions comprising an organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups, or combinations thereof, and a titanate-based or zirconate-based catalyst are highly desirable for applications involving porous building materials because such sealants have little or no deleterious effect on the porous substrates onto which they are cured.

[0006] When a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups, or combinations thereof and a titanate-based or zirconate-based catalyst is applied to a porous substrate surface (e.g., building materials such as stone, marble, brick, concrete, cement, and other cementitious substrates), minimal or no bubbling occurs in the sealant at the sealant / substrate interface at room temperature. Advantageously, there is good adhesion between the substrate and the resulting cured sealant, and thus the surface of the relevant porous substrate does not need to be pre-coated with a thin primer layer (typically no more than 12.5 μm thick) prior to application.

[0007] However, a major problem for construction workers in hot countries is that blistering within the cured layer of a one-part room temperature vulcanizable (RTV) silicone composition at the sealant / substrate interface gradually increases and becomes particularly noticeable as the ambient temperature, particularly the temperature of the substrate, rises in hot climates when the substrate surface reaches 40°C or higher, which may often occur when the substrate is exposed to direct sunlight for several hours during a working day. When the temperature of the substrate is above 40°C, the generation of bubbles in a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups selected from alkoxy groups, hydroxyl groups, or a combination thereof per molecule and a titanate-based or zirconate-based catalyst is generally significant, resulting in surface blistering and poor adhesion. Without being bound by existing theory, it is believed that when these one-part room temperature vulcanizable (RTV) silicone compositions are applied to porous substrates (especially building materials such as stone, marble, brick, concrete, cement and other cementitious substrates that are generally hydrophilic) at elevated temperatures (e.g., above 40° C.), as the substrate temperature increases, more and more moisture / water vapor will condense or accumulate at the interface of the one-part room temperature vulcanizable (RTV) silicone composition and the porous substrate, driven by capillary action and the reactivity of moisture with the composition. It is believed that this leads to increasing hydrolysis of the alkoxysilyl groups at the interface and, therefore, to accelerated production of alcohols, especially methanol, at the substrate / composition interface. Typically, the alcohols (especially methanol) produced have low boiling points at atmospheric pressure, and because methanol production is accelerated at elevated temperatures at the interface, its production rate gradually exceeds its penetration rate through the bulk composition, resulting in blistering within the cured and ultimately cured composition. The bubbles produced are unacceptable because they not only lead to surface blistering, but also to very poor adhesion. Weather sealing substrates and other building processes involving the use of one-part room temperature vulcanizable (RTV) silicone compositions, such as sealing joints between substrates and / or around windows, sashes and frames, and facades etc., need to be done during the working day as and when the work requires it, and waiting for cooler overnight temperatures is not an option for effective work, and therefore this can be a major issue in the construction industry, especially for countries with hot climates.

[0008] Binders or film formers (hereinafter referred to as binders) are film-forming components of coatings such as paints, which are usually mixed with solvents and various additives to produce the desired coating composition. In use, the coating composition is applied to a substrate and allowed to dry or cure, while the solvent evaporates and the binder dries and / or coalesces into a cohesive film coating on the surface of the substrate.

[0009] Provided herein is a method of applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups, or combinations thereof and a titanate-based or zirconate-based catalyst to a hot porous substrate at a temperature of at least 40° C., the method comprising the steps of:

[0010] (i) treating an aqueous or solvent-based adhesive composition at a temperature of at least 40° C., wherein the aqueous or solvent-based adhesive composition comprises at least 20% by weight of a binder selected from the group consisting of (meth)acrylic resins, poly(meth)acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane and a silicone resin having the structure

[0011] M (a) D (b) T (c) Q (d)

[0012] Where a, b, c and d are mole fractions, 0 <a<1,b≥0,c≥0,d≥0,c+d> 0+b+c+d=1 and a+d≠1; or a mixture of two or more thereof;

[0013] applying to a surface of a thermally porous substrate;

[0014] (ii) drying and / or curing the aqueous or solvent-based binder composition to allow the binder to coalesce and form a continuous elastic binder film on the thermal porous substrate, and then

[0015] (iii) applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups selected from alkoxy groups, hydroxyl groups or a combination thereof per molecule and a titanate-based or zirconate-based catalyst onto the surface of the continuous elastic adhesive film and curing it.

[0016] The porous substrate may be, for example, a building material such as stone, marble, brick, concrete, cement and other cementitious substrates.

[0017] Also provided is a sealed porous substrate as a product of the above method.

[0018] Also provided herein is a thermally porous substrate coated with a cured layer of a one-part room temperature vulcanizable (RTV) silicone composition at a temperature of at least 40° C., the cured layer being obtained or obtainable by the following steps:

[0019] (i) at a temperature of at least 40°C

[0020] A water-based or solvent-based adhesive composition, the water-based or solvent-based adhesive composition comprising at least 20% by weight of the adhesive, the adhesive being selected from (meth)acrylic resins, poly(meth)acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane, and a silicone resin having the following structure

[0021] M (a) D (b) T (c) Q (d)

[0022] Where a, b, c and d are mole fractions, 0 <a<1,b≥0,c≥0,d≥0,c+d> 0, a+b+c+d=1 and a+d≠1, or a mixture of two or more thereof;

[0023] applying to a surface of a thermally porous substrate;

[0024] (ii) drying and / or curing the aqueous or solvent-based binder composition to allow the binder to coalesce and form a continuous elastic binder film on the thermal porous substrate, and then

[0025] (iii) applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups selected from alkoxy groups, hydroxyl groups or a combination thereof per molecule and a titanate-based or zirconate-based catalyst onto the surface of the continuous elastic adhesive film and curing it.

[0026] This article also provides

[0027] Use of an aqueous or solvent-based binder composition in a method for applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups or combinations thereof and a titanate-based or zirconate-based catalyst to a thermally porous substrate at a temperature of at least 40° C., the aqueous or solvent-based binder composition comprising at least 20% by weight of the binder selected from (meth)acrylic resins, poly(meth)acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane and a silicone resin having the structure

[0028] M (a) D (b) T (c) Q (d)

[0029] Where a, b, c and d are mole fractions, 0 <a<1,b≥0,c≥0,d≥0,c+d> 0, a+b+c+d=1 and a+d≠1, or a mixture of two or more thereof;

[0030] The method comprises the steps of applying an aqueous or solvent-based binder composition comprising at least 20% by weight of the binder to the surface of a thermally porous substrate at a temperature of at least 40°C;

[0031] drying and / or curing the aqueous or solvent-based binder composition comprising at least 20% by weight of the binder to allow the binder to coalesce and form a continuous elastic binder film on the thermal porous substrate; and then

[0032] A one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups, or combinations thereof and a titanate-based or zirconate-based catalyst is applied on the surface of the continuous elastic adhesive film and cured.

[0033] Also provided is a method for filling a space between a first substrate and a second substrate to create a seal therebetween, at least one of the first substrate and the second substrate being a thermally porous substrate at a temperature of at least 40° C., the seal having a cured layer of a one-part room temperature vulcanizable (RTV) silicone composition, the method comprising:

[0034] (i) at a temperature of at least 40°C

[0035] A water-based or solvent-based adhesive composition, the water-based or solvent-based adhesive composition comprising at least 20% by weight of the adhesive, the adhesive being selected from (meth) acrylic resin, poly (meth) acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane, a silicone resin having the following structure

[0036] M (a) D (b) T (c) Q (d)

[0037] Where a, b, c and d are mole fractions, 0 <a<1,b≥0,c≥0,d≥0,c

[0038] +d>0, a+b+c+d=1 and a+d≠1, or a mixture of two or more thereof;

[0039] at least partially applied to a surface of the thermally porous substrate;

[0040] (ii) drying and / or curing the aqueous or solvent-based binder composition to allow the binder to coalesce and form a continuous elastic binder film at least on the thermal porous substrate; and then

[0041] (iii) applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups selected from alkoxy groups, hydroxyl groups or a combination thereof per molecule and a titanate-based or zirconate-based catalyst onto the surface of the continuous elastic adhesive film and curing it.

[0042] As used herein, the concept “comprising” is used in its broadest sense to mean and encompass the concepts “including” and “consisting of.”

[0043] For the purposes of this application, "substituted" means that one or more hydrogen atoms in a hydrocarbon group are replaced by another substituent. Examples of such substituents include, but are not limited to, halogen atoms such as chlorine, fluorine, bromine, and iodine; groups containing halogen atoms such as chloromethyl, perfluorobutyl, trifluoroethyl, and nonafluorohexyl; oxygen atoms; groups containing oxygen atoms such as (meth)acrylic acid and carboxyl; nitrogen atoms; groups containing nitrogen atoms such as amino functional groups, amido functional groups, and cyano functional groups; sulfur atoms; and groups containing sulfur atoms such as mercapto groups.

[0044] The methods described herein include contacting an aqueous or solvent-based adhesive composition with a hot surface of a porous substrate at a temperature of at least 40° C., then drying and / or curing the aqueous or solvent-based adhesive composition on the substrate surface to form a continuous elastic adhesive film, then applying a one-part room temperature vulcanizable (RTV) silicone composition to the continuous elastic adhesive film on the substrate, and then exposing the combination of the substrate and sealant composition to atmospheric moisture to obtain a silicone sealant bonded to a hot porous substrate, etc.

[0045] The method was found to produce a cured product of a one-part room temperature vulcanizable (RTV) silicone composition bonded to a hot porous substrate at a temperature of at least 40°C, which cured product contains a reduced number of bubbles when applied directly to the hot substrate surface compared to an equivalent cured product. In addition to the reduced number of bubbles formed, the bubbles that are formed are smaller in diameter.

[0046] Thus, we have surprisingly found that providing a continuous elastomeric adhesive film on a thermally porous substrate prior to application of a one-part room temperature vulcanizable (RTV) silicone composition effectively prevents capillary action in the substrate and, therefore, prevents the generation of alcohol at the substrate / one-part room temperature vulcanizable (RTV) silicone composition interface.

[0047] It is important that the resulting continuous elastic adhesive film produced when the aqueous or solvent-based adhesive composition is applied to the substrate at a temperature of at least 40°C is continuous and elastic, i.e. not brittle. The thickness of the film is or preferably is a minimum of 20 μm. This can be determined, for example, in a laboratory setting by checking the thickness of the substrate before applying the aqueous or solvent-based adhesive composition and then subsequently checking the thickness of the substrate with the applied continuous elastic coating film and determining the difference. Typically, the thickness of the continuous elastic adhesive film is in the range of 30 μm to 300 μm, alternatively 50 μm to 200 μm.

[0048] This enables the resulting continuous elastic adhesive film to physically separate the one-part room temperature vulcanizable (RTV) silicone composition from the hot porous substrate during the curing process on the hot porous substrate at a temperature of at least 40°C.

[0049] The binder in the aqueous or solvent-based binder composition containing at least 20% by weight of the binder may be any suitable binder selected from the group consisting of (meth)acrylic resins, poly(meth)acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane, and silicone resins having the following structure:

[0050] M (a) D (b) T (c) Q (d)

[0051] Where a, b, c, and d are mole fractions, 0 can be used. <a<1,b≥0,c≥0,d≥0,c+d> 0, a+b+c+d=1 and a+d≠1.

[0052] For example, for exemplary (meth) acrylic resins, the binder used can have any suitable weight average molecular weight, such as 10,000 g / mol to 5,000,000 g / mol, such as 20,000 g / mol to 1,000,000 g / mol, alternatively 30,000 g / mol to 750,000 g / mol, alternatively 50,000 g / mol to 750,000 g / mol, alternatively 75,000 g / mol to 750,000 g / mol. As used herein, unless otherwise indicated, the phrase "molecular weight" refers to the weight average molecular weight measured by gel permeation chromatography (GPC) relative to polystyrene (PS) standards.

[0053] (Meth)acrylic acid based resins are formed by the polymerization of esters of acrylic acid or methacrylic acid with various special (meth)acrylate monomers. As used herein, the term (meth)acrylate is intended to refer to both acrylates and methacrylates.

[0054] When the binder in the aqueous or solvent-based binder composition comprising at least 20% by weight of the binder is a (meth) acrylic resin, the (meth) acrylic resin may include particles and / or microparticles of (meth) acrylic polymer resins or be composed thereof. Such (meth) acrylic resin particles will have a particle size diameter in the range of 75nm to 450nm, alternatively 100nm to 375nm, alternatively 115nm to 375nm, or alternatively 150nm to 300nm. As used herein, unless otherwise indicated, the term "average particle size" for (meth) acrylic resins refers to the particle size measured by light scattering (LS) using the BI-90 particle size analyzer of Brookhaven Instruments Corp. (Holtsville, NY, New York).

[0055] The (meth)acrylic resin may have any suitable weight average molecular weight, for example, from 30,000 g / mol to 1,000,000 g / mol, for example from 50,000 g / mol to 750,000 g / mol, alternatively from 100,000 g / mol to 750,000 g / mol. As used herein, unless otherwise indicated, the phrase "molecular weight" (for (meth)acrylic resins) refers to the weight average molecular weight measured by gel permeation chromatography (GPC) relative to polystyrene (PS) standards.

[0056] The (meth)acrylic resin may have any suitable glass transition temperature (Tg), for example, it may have a Tg in the range of -50°C to 100°C. The (meth)acrylic resin may have a pH in the range of 7 to 10. As used herein, unless otherwise indicated, the term "Tg" or "glass transition temperature" of a polymer with respect to a (meth)acrylic emulsion and its components refers to the Tg of the polymer calculated using the Fox equation (TGFox, Bull. Am. Physics Soc., Vol. 1, No. 3, p. 123 (1956)).

[0057] Representative, non-limiting examples of commercially produced aqueous dispersions of (meth)acrylic polymers useful in the binders of the present disclosure include those sold under the following trade names: PRIMAL TM SS-640、PRIMAL TM AC-339、PRIMAL TM E-822K、UCAR TM Latex DL 420G, PRIMAL TM AC-337ER、PRIMALTM CM-330、PRIMAL TM AC-285andPRIMAL TM CM-160, RHOPLEX TM SG-10, RHOPLEX TM EI-2000、RHOPLEX TM 78C and RHOPLEX TM EC-1741 (both purchased from DOW, Inc.) and Rohm from Darmstadt, Germany ( PLEXIGLAS GmbH ofDarmstadt Germany) TM 6N, PLEXIGLAS TM 7N and PLEXIGLAS TM 8N.

[0058] For the avoidance of doubt, silicone resins according to the present disclosure may be described using shorthand (abbreviated) nomenclature using the following general formula:

[0059] M (a) D (b) T (c) Q (d)

[0060] Where a, b, c and d are mole fractions, 0 <a<1,b≥0,c≥0,d≥0,c+d> 0, a+b+c+d=1 and a+d≠1 (i.e. a+d cannot be 1), and M=(R 1 R 2 R 3 SiO 1 / 2 )D=(R 4 R 5’ SiO 2 / 2 ), T=(R 6’ SiO 3 / 2 ) and Q=(SiO 4 / 2 ), the resin has a weight average molecular weight of about 1,000 to about 100,000 based on standard polystyrene by gel permeation chromatography.

[0061] Each R 1 -R 4 , R 5’ and R 6’Independently selected from a monovalent hydrocarbon group, a methanol group, an alkoxy group (preferably a methoxy or ethoxy) or an amino group. Suitable exemplary monovalent hydrocarbon groups include, but are not limited to, alkyl groups such as methyl, ethyl, propyl, pentyl, octyl, undecyl and octadecyl; alkenyl groups, cycloalkyl groups such as cyclopentyl and cyclohexyl; and aryl groups such as phenyl, tolyl, xylyl, benzyl and 2-phenylethyl, and any combination thereof.

[0062] Suitable alkenyl groups contain 2 to about 6 carbon atoms, and can be exemplified by, but not limited to, vinyl, allyl, and hexenyl. The silicone resin can be a DT resin, MT resin, MDT resin, DTQ resin, MTQ resin, MDTQ resin, DQ resin, DTQ resin, MTQ resin, or MDQ resin, wherein the main D units (R 4 R 5 SiO 2 / 2 ) and T unit (R 6 SiO 3 / 2 DT resins of 50% to 100% are particularly preferred. MQ resins (where a+d=1) are not used because they are too powdery and do not provide a continuous elastic film.

[0063] Solutions of aqueous or solvent-based binder compositions may consist solely of binder and solvent, provided the binder / solvent combination is viscous enough to be applied in a sufficiently thick layer and cured / dried.

[0064] When the aqueous or solvent-based binder composition is aqueous, the solvent used is water or substantially, ie at least 95%, water and, for example, small amounts of, for example, alcohol.

[0065] When the aqueous or solvent-based binder composition is a solvent-based binder composition, the binder selected for use is dissolved in an organic solvent suitable for the particular binder. Depending on the binder used, the organic solvent may be selected from one or more of the following:

[0066] Straight or branched alkanes having 6 to 16 carbons, such as hexane, heptane, and octane; isoalkanes having 6 to 16 carbons, such as isodecane, isododecane, and isohexadecane; aromatic hydrocarbons, such as naphtha, benzene, toluene, and xylene; alcohols, such as methanol, ethanol, isopropanol, butanol, and n-propanol; aldehydes; ketones, such as methyl isobutyl ketone, acetone, methyl ethyl ketone; amines; esters, such as tert-butyl acetate, methyl acetate, ethyl acetate, n-butyl acetate, methyl formate, isodecyl neopentanoate, isohexyl neopentanoate, ethyl 3-ethoxypropionate, tridecyl neopentanoate, octyldodecyl neopentanoate, diisobutyl adipate, diisopropyl adipate, and octyl palmitate; ethers, such as octyl ether; glycols, such as propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, propylene glycol, Alcohols; glycol ethers such as glycol n-butyl ether, propylene glycol n-butyl ether, propylene glycol dicaprylate / dicaprate, propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol n-butyl ether, propylene glycol n-propyl ether, ethylene glycol n-butyl ether and propylene glycol methyl ether (PGME); glycol esters such as neopentyl glycol heptanoate, ethylene glycol distearate, propylene glycol methyl ether acetate and propylene glycol methyl ether acetate (PGMEA); halogenated hydrocarbons such as dichloromethane, 1,1,1-trichloroethane and dichloromethane; chloroform; aromatic halides and other solvents such as dimethyl sulfoxide; dimethylformamide, acetonitrile; tetrahydrofuran; white spirit; solvent oil; N-methylpyrrolidone; etc., and derivatives, modifications and combinations thereof.

[0067] The binder can be applied to the hot substrate surface as an aqueous composition comprising water and at least 20% by weight of the binder in the composition, alternatively from 20% to 75% by weight of the binder in the composition, alternatively from 25% to 70% by weight of the binder in the composition.

[0068] Alternatively, the binder may be applied in a solvent-based composition comprising a non-aqueous solvent and at least 20% by weight of the binder in the composition, alternatively from 20% to 75% by weight of the binder in the composition, alternatively from 25% to 70% by weight of the binder in the composition.

[0069] Optionally, one or more additives may be present in the aqueous or solvent-based adhesive composition binder. These may include, for example, one or more silanes having at least two hydrolyzable groups per molecule, alternatively silane coupling agents (such as aminosilanes, epoxysilanes, mercaptosilanes, etc.) and catalysts, such as titanates, zirconates and / or aluminum organometallic compounds, and any combination thereof.

[0070] In the case of silane, one or more silanes having at least two or three hydrolyzable groups per molecule can be provided. Any suitable hydrolyzable group can be used, such as an alkoxy group, an acetoxy group and an oxime group, but preferably an alkoxy group. The alkoxy group can be the same or different, and generally has 1 to 10 carbons, alternatively 1 to 6 carbons, alternatively a methoxy or ethoxy group. When the silane has two or three hydrolyzable groups, such as two or three alkoxy groups, each other group is suitably an organic group bonded to silicon that is not hydrolyzable, which is generally a hydrocarbon group that can be substituted by halogens such as fluorine and chlorine. Examples of such other groups include alkyl groups (such as methyl, ethyl, propyl and butyl); cycloalkyl groups (such as cyclopentyl and cyclohexyl); alkenyl groups (such as vinyl and allyl); aryl groups (such as phenyl and tolyl); aralkyl groups (such as 2-phenylethyl) and groups obtained by replacing all or part of the hydrogen in the aforementioned organic groups with halogens. Preferably, however, each other silicon-bonded organic group is an alkyl group having 1 to 6 carbons (such as a methyl or ethyl group) or an alkenyl group having 2 to 6 carbons (such as a vinyl group).

[0071] Specific examples of silanes that can be incorporated into the aqueous or solvent-based adhesive composition as an additive include, but are not limited to, alkyltrialkoxysilanes such as methyltrimethoxysilane (MTM), ethyltrimethoxysilane and methyltriethoxysilane; alkenyltrialkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane, isobutyltrimethoxysilane (iBTM). Other suitable silanes include phenyltrimethoxysilane, alkoxytrioxime silane, alkenyltrioxime silane, 3,3,3-trifluoropropyltrimethoxysilane, methyltri(methylethylketoxime)silane, vinyl-tri-methylethylketoxime)silane, methyltri(methylethylketoxime)silane, methyltri(isopropenyloxy)silane, vinyltri(isopropenyloxy)silane, (ethylenediaminepropyl)trimethoxysilane, vinyltrimethoxysilane, having the general formula SiOR 4 tetraalkyl orthosilicates, tetraethoxysilane, mercapto-functionalized-silanes, glycidoxypropyltrimethoxysilane, and any combination thereof.

[0072] In the case of titanates, zirconates and / or aluminum organometallic compounds or any combination thereof, the titanates may include but are not limited to tetrabutyl titanate, tetrapropoxy titanate, tetraethoxy titanate, tetrapentyl titanate, diisopropoxy bisethyl acetoacetate titanium, diisopropoxy bisacetylacetonate titanium and any combination thereof; the zirconates may include but are not limited to zirconium acetylacetonate, and the aluminum organometallic compound may be but is not limited to aluminum acetylacetonate.

[0073] In one embodiment, the aqueous or solvent-based binder composition may be a primer composition, provided that the binder used is present in an amount of at least 20% by weight of the primer composition, alternatively 20% to 75% by weight of the binder in the composition, alternatively 20% to 70% by weight of the binder in the composition.

[0074] A primer is a preparatory coating that is applied to a substrate and allowed to dry and / or cure to provide improved adhesion between the substrate and a coating subsequently applied thereon. Primers are intended to provide enhanced adhesion between the substrate and the coating. However, the use of primers is generally not preferred because these primers can be unreliable, can have quality control and reliability issues, and traditionally contain a high proportion of organic solvents that evaporate during the drying / curing process, often resulting in undesirable volatile organic compound (VOC) environmental issues.

[0075] A small amount of commercial primers contain at least 20% by weight of a binder in the primer composition. Such primers are designed to have film-forming and adhesion-promoting effects on room temperature vulcanizable (RTV) silicone compositions when applied to substrates at room temperature (i.e., typically 20°C to 25°C). However, these are generally not required to adhere cured silicone materials to porous substrates (such as stone, marble, brick, concrete, cement and other cementitious substrates) at room temperature. In addition, there is no teaching that the primer needs to be applied to porous substrates (such as stone, marble, brick, concrete, cement and other cementitious substrates) at a temperature of at least 40°C, and it is believed that there is no prior art indicating that applying such primer compositions to substrates at a temperature of at least 40°C will prevent or substantially prevent the foaming problem in the one-part room temperature vulcanizable (RTV) silicone compositions that occurs at those temperatures. Therefore, the method described herein is a surprising development that appears to solve a major problem in hot countries. Without being bound by present theory, it is believed that applying an aqueous or solvent-based adhesive composition results in the formation of an elastic adhesive film that blocks the pores on the substrate surface and thus prevents a bubbling effect when a one-part room temperature vulcanizable (RTV) silicone composition is later applied on top of the elastic adhesive film.

[0076] In other embodiments, it is determined that if desired, a predetermined amount of a binder selected from (meth)acrylic resins, poly(meth)acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane, or a silicone resin having the following structure can be introduced into the primer composition to form an aqueous or solvent-based binder composition comprising at least 20 wt. % of a binder in the primer composition:

[0077] M (a) D (b) T (c) Q(d)

[0078] Where a, b, c and d are mole fractions, 0 <a<1,b≥0,c≥0,d≥0,c+d> 0, a+b+c+d=1 and a+d≠1, or mixtures thereof. The adhesion performance of the aqueous or solventborne binder composition when it comprises a primer or a modified primer containing an additional binder is considered superfluous for this application, provided that the modified primer composition is capable of forming a suitable continuous elastic binder film when applied to a hot porous substrate at 40°C.

[0079] Any suitable primer can be used for this application, and condition is that they contain the binding agent (at least 20 weight %) of necessary amount in its composition, or they can be modified to contain these binding agents.This type of primer can be water-based or solvent-based.In the case of solvent-based primer, solvent can be any one of those listed above for the binding agent composition.They can contain a variety of other ingredients, such as one or more silanes and catalysts with at least three hydrolyzable groups per molecule, such as titanates, zirconates and / or aluminum organometallic compounds as described above.They can additionally include one or more organotin compounds, such as but not limited to alkyl tin ester compounds, such as dibutyl tin dioctoate, dibutyl tin dimaleate, 2-ethylhexanoic acid butyl tin, dimethyl tin dineodecanyl ester or dibutyl tin dilaurate, dibutyl tin acetate and 2-ethylhexanoic acid dibutyl tin, and any combination thereof.

[0080] Any suitable silicone sealant primer suitable for priming the porous substrates described herein (i.e., architectural and / or building materials used to form the exterior of buildings, such as concrete, marble, brick and stone) can be used as the water-based or solvent-based adhesive composition herein. For example, commercial primers that can be used include DOWSIL TM Building Primer B and DOWSIL TM Architectural Primer P, and commercial primers that can be used as waterborne or solventborne binder compositions when modified by the addition of a binder may include DOWSIL TM 1200OS Primer and DOWSIL TM Primer-C, all of which are commercially available from Dow Silicones Corporation of Midland Michigan USA. Preferably, when a commercial primer is modified, the binder added to the primer and the primer itself are miscible in the combination used.

[0081] In step (i) of the above method, an aqueous or solvent-based binder composition comprising at least 20% by weight of the binder selected from (meth)acrylic resins, poly(meth)acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane or silicone resins or a mixture of two or more thereof as described above is applied to the surface of the thermoporous substrate at a temperature of at least 40° C. The thermoporous substrate is a building and / or construction material used to form the exterior of a building, such as stone, marble, brick, concrete, cement and other cementitious substrates, for example, in the case of stone, the substrate may be a stone facade that can be heated to a temperature well above 40° C. in direct sunlight.

[0082] Any suitable silicone sealant primer suitable for priming the porous substrates described herein (i.e., architectural and / or building materials used to form the exterior of buildings, such as concrete, marble, brick, and stone) can be used in the present disclosure. The aqueous or solvent-based binder composition is contacted with the hot porous surface by conventional means such as extrusion, coating, injection, knife coating, wiping, and rolling. The surface of the porous substrate is at a temperature of at least 40°C.

[0083] The binder composition can be prepared by mixing the binder and the selected solvent together and introducing any additional ingredients simultaneously or subsequently. Alternatively, if the aqueous or solvent-based binder composition used is a modified primer composition, a predetermined amount of binder can be mixed into the primer composition to ensure that the binder composition applied to the surface of the thermal porous substrate at a temperature of at least 40° C. contains at least 20% by weight of the binder in the modified primer composition. The resulting binder composition can be in the form of a solution, emulsion or dispersion, depending on the solubility of the other ingredients in the solvent.

[0084] In step (ii) of the method, the aqueous or solvent-based adhesive composition is dried and / or cured so that the adhesive can coalesce and form a continuous elastic adhesive film on the thermal porous substrate. The resulting continuous elastic adhesive film comprises all non-volatile components of the aqueous or solvent-based adhesive composition, and therefore if a modified primer is used, all non-volatile components of the modified silicone sealant primer are included. In fact, it is possible that one or more of the components of the aqueous or solvent-based adhesive composition applied as herein can react with the adhesive during the formation of the continuous elastic adhesive film. Given the temperature of the thermal porous substrate and caused by sunlight / air near the substrate, the drying / curing of the aqueous or solvent-based adhesive composition does not require methods such as heating. Compared with drying / curing at a temperature of, for example, 20°C to 25°C, the temperature of the climate rise will actually accelerate the drying / curing period.

[0085] In step (iii), a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups selected from alkoxy groups, hydroxyl groups or combinations thereof per molecule and a titanate-based or zirconate-based catalyst is applied to the surface of the continuous elastic adhesive film obtained from step (ii) and cured thereon. It is applied on top of the continuous elastic adhesive film and then allowed to cure at the ambient temperature at the time of application. When the one-part room temperature vulcanizable (RTV, i.e., typically 20°C to 25°C) silicone composition is applied to a hot porous substrate at a temperature above 40°C, the method herein prevents or minimizes the problem of undesirable bubbling, because the continuous elastic adhesive film produced by applying the aqueous or solvent-based adhesive composition to the surface of the hot porous substrate will effectively isolate the one-part room temperature vulcanizable (RTV) silicone composition from the surface of the substrate and prevent direct contact between the substrate surface and the one-part room temperature vulcanizable (RTV) silicone composition during the curing process when bubbling occurs.

[0086] Most one-part room temperature vulcanizable (RTV) silicone compositions having at least two groups per molecule selected from alkoxy groups, hydroxyl groups, or combinations thereof and containing a titanate-based or zirconate-based catalyst typically contain a minimum of four ingredients:

[0087] 1. An organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups or combinations thereof, typically at least two trialkoxy-silyl terminal groups per molecule;

[0088] 2. one or more suitable cross-linking agents;

[0089] 3. Fillers; and

[0090] 4. Titanate-based or zirconate-based catalysts.

[0091] One-part room temperature vulcanizable (RTV) silicone compositions having at least two groups per molecule selected from alkoxy groups, hydroxyl groups, or combinations thereof and containing a titanate-based or zirconate-based catalyst also typically include a variety of additives that are incorporated into the composition to meet the necessary properties required by the applicant / building industry in which they are used. Such additives typically include one or more of adhesion promoters, diluents (e.g., plasticizers and / or extenders), chain extenders, flame retardants, solvent resistance additives, biocides, etc., which are also typically incorporated into these compositions as needed and when required.

[0092] One advantage of the present method is that any suitable one-part room temperature vulcanizable (RTV) silicone composition can be applied to the hot porous substrate at a temperature of at least 40° C. by preparing a continuous elastic adhesive film on the hot porous substrate prior to applying the one-part room temperature vulcanizable (RTV) silicone composition having at least two groups per molecule selected from alkoxy groups, hydroxyl groups, or combinations thereof and containing a titanate-based or zirconate-based catalyst. An example of a typical one-part room temperature vulcanizable (RTV) silicone composition is provided below, but it should be understood that such composition is provided merely as an example of the type of composition that may be selected for use and is in no way intended to limit the scope of one-part room temperature vulcanizable (RTV) silicone compositions that may now be applied to hot porous substrates in view of the new method.

[0093] A one-part room temperature vulcanizable (RTV) silicone composition having at least two groups per molecule selected from alkoxy groups, hydroxyl groups, or combinations thereof and containing a titanate-based or zirconate-based catalyst may be as follows:

[0094] (I) an organopolysiloxane polymer having at least two groups selected from alkoxy groups, hydroxyl groups or combinations thereof per molecule, typically at least two trialkoxy-silyl terminal groups per molecule; for example

[0095] An organopolysiloxane polymer having at least two groups selected from alkoxy groups, hydroxyl groups or combinations thereof per molecule of the formula

[0096] X 3-n R n Si-Z d -(R 1 y SiO (4-y) / 2 ) z –SiR 1 2 -Z d -Si-R n X 3-n (1)

[0097] wherein each X is independently a hydroxyl group or an alkoxy group, each R is an alkyl, alkenyl or aryl group, and each R 1 is an X group, an alkyl group, an alkenyl group or an aryl group and Z is a divalent organic group;

[0098] d is 0 or 1,

[0099] n is 0, 1 or 2, y is 0, 1 or 2, and preferably 2, and z is an integer such that the organopolysiloxane polymer has a viscosity of 30,000 to 150,000 mPa.s at 25°C in an amount of 30 to 90% by weight of the composition;

[0100] (II) a suitable cross-linking agent having three or more hydrolyzable groups per molecule;

[0101] (III) a filler selected from precipitated silica, fumed silica or precipitated calcium carbonate or a mixture of two or more thereof;

[0102] (IV) Titanate-based or zirconate-based catalysts

[0103] An organic polysilicone having at least two groups selected from alkoxy groups, hydroxyl groups or combinations thereof per molecule Oxyalkyl polymer (I)

[0104] The organopolysiloxane polymer (I) having at least two groups selected from alkoxy groups, hydroxyl groups or a combination thereof per molecule has the following formula:

[0105] X 3-n R n Si-Z d -(R 1 y SiO (4-y) / 2 ) z –SiR 1 2 -Z d -Si-R n X 3-n (1)

[0106] In the above formula, each X is independently a hydroxyl group or an alkoxyl group, provided that each polymer contains at least two groups selected from alkoxyl groups, hydroxyl groups or combinations thereof per molecule (therefore, each molecule must have at least two X groups). In one embodiment, all X groups may be hydroxyl groups or identical or different alkoxyl groups. Preferably, each alkoxyl group has 1 to 10 carbons, and exemplary alkoxyl groups are methoxyl, ethoxyl, propoxyl, isopropoxyl, n-butoxyl, tert-butoxyl, isobutoxyl, pentyloxyl, hexyloxyl and 2-ethylhexyloxyl; dialkoxyl groups such as methoxymethoxyl or ethoxymethoxyl, and alkoxyaryloxy groups such as ethoxyphenoxyl groups; alternatively, each X is an alkoxyl group having one to six carbons, alternatively one to four carbons, or alternatively a methoxyl or ethoxyl group.

[0107] Each R group is an alkyl, alkenyl or aryl group, alternatively each R is an alkyl group with 1 to 6 carbons, an alkenyl group with 2 to 6 carbons (such as vinyl, allyl and hexenyl groups) or an aryl group with 6 to 12 carbons; alternatively each R is an alkyl group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons; alternatively each R is an alkyl group with 1 to 6 carbons, alternatively each R is an ethyl group or a methyl group. In one embodiment, R may include a substituted aliphatic organic group, such as a 3,3,3-trifluoropropyl group, an aminoalkyl group, a polyaminoalkyl group and / or an alkylene oxide group.

[0108] Each R 1 is an X group, or an R group, provided that cumulatively at least two X groups and / or R groups per molecule 1 The group is an alkoxy group, alternatively each R 1 is an R group. It is possible that some R 1 The groups may be siloxane branches branching from the polymer backbone and these branches may have terminal groups as described above.

[0109] Each Z is a divalent organic group, typically an alkylene group having 2 to 10 carbons, such as, for example, ethylene, propylene, butylene, pentylene and / or hexylene groups; alternatively an alkylene group having 2 to 6 carbons, alternatively an alkylene group having 2 to 5 carbons. Typically, when each X group is a hydroxyl group, d is 0 (zero), and when each X is an alkoxy group, d is 1. When X is a mixture of hydroxyl groups and alkoxy groups, each d can be 0 (zero) or 1. Subscript n is zero, 1 or 2, alternatively 0 (zero) or 1, alternatively 0 (zero); in one embodiment, when n is zero, each X is an alkoxy group and d is 1. Each subscript y is 0, 1 or 2, and is preferably 2. Although y is 0, 1 or 2, substantially y=2, for example at least 90%, alternatively 95% of R 1 y SiO (4-y) / 2 The group is characterized in that y = 2. The subscript z is an integer such that the organopolysiloxane polymer has a viscosity of 30,000 to 150,000 mPa.s, alternatively 40,000 to 140,000 mPa.s at 25°C, so z is an integer from 300 to 2000.

[0110] The viscosity of component (I) can be measured by any suitable method, such as according to corporate test method CTM 0050, which is publicly available and based on ASTM D1084-16 Method B, using a Brookfield HBDV-III Ultra rheometer equipped with cone-plate geometry, at a rotation speed of 5 rpm using spindle 52 for 2 minutes. Unless otherwise stated, all viscosity measurements herein are made at 25°C.

[0111] Component (I) is present in the one-part room temperature vulcanizable (RTV) silicone composition in an amount of 30% to 90% by weight of the composition, alternatively 35% to 75% by weight of the composition, alternatively 35% to 60% by weight of the composition.

[0112] The organopolysiloxane polymer (I) may be a single siloxane represented by formula (1), or it may be a mixture of organopolysiloxane polymers represented by the above formula. Therefore, it may be a "siloxane polymer mixture", so the organopolysiloxane polymer (I) is meant to include any single organopolysiloxane polymer (I) or a mixture of organopolysiloxane polymers (I).

[0113] The degree of polymerization (DP) (i.e., essentially z in the above formula) is generally defined as the number of monomer units in a macromolecule or polymer or oligomer molecule of an organosilicon. Synthetic polymers always consist of a mixture of macromolecular species with different degrees of polymerization and therefore different molecular weights. There are different types of average polymer molecular weights, which can be measured in different experiments. The two most important average polymer molecular weights are the number average molecular weight (Mn) and the weight average molecular weight (Mw). The Mn and Mw of organosilicon polymers can be determined by gel permeation chromatography (GPC) using polystyrene standards with an accuracy of about 10% to 15%.

[0114] The technique is standard and produces Mw, Mn and polydispersity index (PI). Degree of polymerization (DP) = Mn / Mu, where Mn is the number average molecular weight measured from GPC, and Mu is the molecular weight of the monomer unit. PI = Mw / Mn. DP is associated with the viscosity of the polymer via Mw, and the higher the DP, the higher the viscosity. In the present disclosure, the number average molecular weight and weight average molecular weight values ​​of component (I) herein can be measured, for example, using a Waters 2695 separation module (Waters Corporation of MA, USA) equipped with a vacuum degasser and a Waters 2414 refractive index detector. Certified grade toluene flowing at 1.0 mL / min can then be used as an eluent for analysis. Data collection and analysis can be performed using Waters Empower GPC software.

[0115] Suitable cross-linking agents (II) having three or more hydrolyzable groups per molecule

[0116] Component (II) is one or more crosslinking agents comprising a silicon-containing compound having at least three hydroxyl groups and / or hydrolyzable groups per molecule that react with the alkoxy and optional hydroxyl groups in component (I).

[0117] The silicon-containing compound having at least three hydroxyl groups and / or hydrolyzable groups per molecule of component (II) may be, for example:

[0118] One or more silanes having at least 3 hydrolyzable groups per molecular group;

[0119] One or more dipodal silanes having at least two silyl groups, each silyl group containing at least one hydrolyzable group or

[0120] Other suitable silicon-containing compounds have at least three hydroxyl and / or hydrolyzable groups per molecule.

[0121] For the purposes of this disclosure, a bipodal silane comprises two silicon atoms, each silicon atom having at least one hydrolyzable group, wherein the silicon atoms are separated by an organic polymer chain or a siloxane polymer chain or copolymer chain. Typically, each silyl group on the bipodal silane can be a terminal group.

[0122] The hydrolyzable group of component (II) can be selected from acyloxy groups (e.g., acetoxy, octanoyloxy, and benzoyloxy groups); ketoxime groups (e.g., dimethylketoxime and isobutylketoxime); alkoxy groups (e.g., methoxy, ethoxy, and propoxy) and alkenyloxy groups (e.g., isopropenyloxy and 1-ethyl-2-methylvinyloxy). In some cases, the hydrolyzable group may include a hydroxyl group. Alternatively, the hydrolyzable group is selected from acyloxy groups; alkoxy groups and / or alkenyloxy groups. In a preferred embodiment, the hydrolyzable group is an alkoxy group having 1 to 10 carbons.

[0123] Thus, when component (II) is a silane, the silane may have the following structure:

[0124] R 8 j Si(OR 9 ) 4-j

[0125] Each R 9 may be the same or different and are hydrogen or an alkyl group containing at least one carbon, alternatively 1 to 20 carbons, alternatively 1 to 10 carbons, alternatively 1 to 6 carbons. j has a value of 0 or 1. Although each R 9 The groups may be the same or different, but preferably at least two R 9 The groups are the same, optionally at least three R 9 groups are the same, and alternatively when j is 0, all R 9 The groups are the same.

[0126] Therefore, when j is zero, specific examples of the reactive silane (II) include tetraethyl orthosilicate, tetrapropyl orthosilicate, tetra-n-butyl orthosilicate, and tetra-tert-butyl orthosilicate.

[0127] When j is 1, the group R 8 Yes. 8 is a silicon-bonded organic group selected from a substituted or unsubstituted straight or branched monovalent hydrocarbon group having at least one carbon, a cycloalkyl group, an aryl group, an aralkyl group, or any of the foregoing groups, wherein at least one hydrogen atom bonded to the carbon is substituted with a halogen atom, or an organic group having an epoxy group, a glycidyl group, an acyl group, a carboxyl group, an ester group, an amino group, an amide group, a (meth)acryloyl group, a mercapto group, an isocyanurate group, or an isocyanate group.

[0128] Suitable as R 8The unsubstituted monovalent hydrocarbon group may include an alkyl group (e.g., methyl, ethyl, propyl, and other alkyl groups), an alkenyl group (such as vinyl), and the cycloalkyl group may include a cyclopentane group and a cyclohexane group. For example, 8 The substituted groups may include a 3-hydroxypropyl group, a 3-(2-hydroxyethoxy)alkyl group, a halopropyl group, a 3-mercaptopropyl group, a trifluoroalkyl group such as a 3,3,3-trifluoropropyl group, a 2,3-epoxypropyl group, a 3,4-epoxybutyl group, a 4,5-epoxypentyl group, a 2-glycidyloxyethyl group, a 3-glycidyloxypropyl group, a 4-glycidyloxybutyl group, a 2-(3,4-epoxycyclohexyl)ethyl group, a 3-(3,4-epoxycyclohexyl)alkyl group, an aminopropyl group, an N-methylaminopropyl group, an N-butylaminopropyl group, an N,N-dibutylaminopropyl group, a 3-(2-aminoethoxy)propyl group, a methacryloyloxyalkyl group, an acryloxyalkyl group, a carboxyalkyl group such as a 3-carboxypropyl group, and a 10-carboxydecyl group.

[0129] Specific examples of suitable silane crosslinkers (II) having at least 3 hydroxyl groups and / or hydrolyzable groups per molecule include, but are not limited to, vinyltrimethoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, ethyltrimethoxysilane, propyltriethoxysilane, isobutyltriethoxysilane, isobutyltrimethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, methyltri(isopropenyloxy)silane or vinyltri(isopropenyloxy)silane, 3-hydroxypropyl ... triethoxysilane, 3-hydroxypropyl trimethoxysilane, 3-(2-hydroxyethoxy)ethyl triethoxysilane, 3-(2-hydroxyethoxy)ethyl trimethoxysilane, chloropropyl triethoxysilane, 3-mercaptopropyl triethoxysilane, 3,3,3-trifluoropropyl triethoxysilane, 2,3-epoxypropyl triethoxysilane, 2,3-epoxypropyl trimethoxysilane, 3,4-epoxybutyl triethoxysilane, 3,4-epoxybutyl trimethoxysilane, 4,5-epoxypentyl triethoxysilane , 4,5-epoxypentyl trimethoxysilane, 2-glycidyloxyethyl triethoxysilane, 2-glycidyloxyethyl trimethoxysilane, 3-glycidyloxypropyl triethoxysilane, 3-glycidyloxypropyl trimethoxysilane, 4-glycidyloxybutyl triethoxysilane, 4-glycidyloxybutyl trimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl triethoxysilane, 3-(3,4-epoxycyclohexyl)ethyl triethoxysilane, aminopropyl triethoxysilane triethoxysilane, 3-(2-aminoethoxy)propyltriethoxysilane, methacryloxypropyltriethoxysilane, tris(3-triethoxysilylpropyl)isocyanurate, acryloxypropyltriethoxysilane, 3-carboxypropyltriethoxysilane and 10-carboxydecyltriethoxysilane.

[0130] In other embodiments, component (II) can be a bipedal silane, i.e. a silyl functional molecule having at least 2 silyl groups, each silyl group having at least 1 and at most 3 hydrolyzable groups, alternatively each silyl group having at least 2 hydrolyzable groups, wherein the silyl groups are separated by a polymer backbone. The polymer backbone can be an organic polymer backbone, i.e. component (II) can include an organic-based polymer having silyl terminal groups, for example, silyl polyethers, silyl acrylates, and silyl-terminated polyisobutylenes. In the case of silyl polyethers, the polymer chain is based on polyoxyalkylene units. Such polyoxyalkylene units preferably include repeating oxyalkylene units (-C n H 2n-O-)-based linear oxyalkylene polymers, the polymers having an average formula (-C n H 2n -O-) y Representation, wherein n is an integer from 2 to 4 (including the end values), and y is an integer of at least four. Similarly, the viscosity will be ≤1000mPa.s at 25°C, or 250mPa.s to 1000mPa.s at 25°C, or 250mPa.s to 750mPa.s at 25°C, and will have a suitable number average molecular weight for each polyoxyalkylene polymer block present. As described above, the viscosity can be measured using any suitable device, such as a Modular Compact Rheometer (MCR) 302 from Anton Paar GmbH of Graz, Austria, using the most appropriate settings and plates for the viscosity involved. In addition, the oxyalkylene units do not have to be the same in the polyoxyalkylene monomers, but can be different between units. The polyoxyalkylene blocks or polymers can, for example, be composed of oxyethylene units (-C 2 H 4 -O-); oxypropylene unit (-C 3 H 6 -O-); or oxybutylene unit (-C 4 H 8 -O-); or a mixture thereof.

[0131] In the case of such crosslinkers based on organic substances, the molecular structure may be linear, branched, cyclic or macromolecular, ie an organic polymer chain with alkoxy-functionalized end groups.

[0132] In one embodiment, the bipodal silane may be a polymer containing two silyl groups, each silyl group containing at least one hydrolyzable group, such as described by the following formula:

[0133] (R 7 O) m (Y 1 ) 3-m –Si(CH 2 ) x –((NHCH 2 CH 2 ) t -Q(CH 2 ) x ) s -Si(OR 7 ) m (Y 1 ) 3-m Where R 7 C 1-10 Alkyl group, Y 1is an alkyl group containing 1 to 8 carbons, Q is a chemical group containing a heteroatom having a lone pair of electrons, such as an amine, an N-alkylamine or a urea; each x is an integer from 1 to 6, t is 0 or 1, each m is independently 1, 2 or 3, and s is 0 or 1.

[0134] Specific examples of suitable bipodal silanes include 1,6-bis(trimethoxysilyl)hexane (alternatively known as hexamethoxydisilylhexane), bis(trialkoxysilylalkyl)amine, bis(dialkoxyalkylsilylalkyl)amine, bis(trialkoxysilylalkyl)N-alkylamine, bis(dialkoxyalkylsilylalkyl)N-alkylamine, bis(trialkoxysilylalkyl)urea, bis(dialkoxyalkylsilylalkyl)urea, bis(3-trimethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)amine, bis(4-trimethoxysilylbutyl)amine, bis(4-triethoxysilylbutyl)amine, bis(3-trimethoxysilyl) bis(3-triethoxysilylpropyl)N-methylamine, bis(3-triethoxysilylpropyl)N-methylamine, bis(4-trimethoxysilylbutyl)N-methylamine, bis(4-triethoxysilylbutyl)N-methylamine, bis(3-trimethoxysilylpropyl)urea, bis(3-triethoxysilylpropyl)urea, bis(4-trimethoxysilylbutyl)urea, bis(4-triethoxysilylbutyl)urea, bis(3-dimethoxymethylsilylpropyl)amine, bis(3-diethoxymethylsilylpropyl)amine, bis(4-dimethoxymethylsilylbutyl)amine, bis(4-diethoxymethylsilylbutyl)amine, bis(3-dimethoxymethylsilylpropyl)N-methylamine amine, bis(3-diethoxymethylsilylpropyl) N-methylamine, bis(4-dimethoxymethylsilylbutyl) N-methylamine, bis(4-diethoxymethylsilylbutyl) N-methylamine, bis(3-dimethoxymethylsilylpropyl) urea, bis(3-diethoxymethylsilylpropyl) urea, bis(4-dimethoxymethylsilylbutyl) urea, bis(4-diethoxymethylsilylbutyl) urea, bis(3-dimethoxyethylsilylpropyl) amine, bis(3-diethoxyethylsilylpropyl) amine, bis(4-dimethoxyethylsilylbutyl) amine, bis(4-diethoxyethylsilylbutyl) amine, bis(3-dimethoxyethylsilylpropyl) amine bis(triethoxysilylpropyl)amine, bis(trimethoxysilylpropyl)amine, bis(trimethoxysilylpropyl)urea, bis(triethoxysilylpropyl)urea, bis(triethoxysilylpropyl)urea, bis(triethoxysilylpropyl)urea, bis(diethoxymethylsilylpropyl)urea; bis(triethoxysilylpropyl)amine, bis(trimethoxysilylpropyl)amine, bis(trimethoxysilylpropyl)urea, bis(diethoxymethylsilylpropyl)urea; bis(triethoxymethylsilylpropyl)amine, bis(triethoxymethylsilylpropyl)urea, bis(diethoxymethylsilylpropyl)urea; bis(triethoxymethylsilylpropyl)amine, bis(triethoxymethylsilylpropyl)urea, bis(diethoxymethylsilylpropyl)urea; bis(triethoxymethylsilylpropyl)urea ...Di- or trialkoxysilyl-terminated polydialkylsiloxanes, di- or trialkoxysilyl-terminated polyaralkylsiloxanes, di- or trialkoxysilyl-terminated polypropylene oxides, polyurethanes, polyacrylates; polyisobutylene; di- or triacetoxysilyl-terminated polydialkyl; polyaralkylsiloxanes; di- or trioxime-terminated polydialkyl; polyaralkylsiloxanes; di- or triacetoneoxy-terminated polydialkyl or polyaralkyl. The component (II) used may also contain any combination of two or more of the above. ;

[0135] Other suitable silicon-containing compounds having at least three hydroxyl and / or hydrolyzable groups per molecule include, for example, 1,3,5-tris(trialkoxysilylalkyl)isocyanurates, such as 1,3,5-tris(trialkoxysilylalkyl)isocyanurates having the following structure:

[0136]

[0137] Each R 5 may be the same or different and are divalent alkylene groups having 2 to 10 carbons, alternatively 2 to 6 carbons, alternatively 2 to 5 carbons, and each R 6 are the same or different and are alkyl groups having 1 to 10 carbons, alternatively 1 to 6 carbons, alternatively 1 to 4 carbons, alternatively methyl groups or ethyl groups. An example is tris-(trimethoxysilylpropyl)isocyanurate as described below, wherein each R 5 is a propylene group and each R 6 It is a methyl group.

[0138]

[0139] One or more cross-linking agents (II) having at least 3 hydroxyl and / or hydrolyzable groups per molecule are present in an amount of 0.1% to 5% by weight of the composition, in an amount of 0.5% to 4% by weight of the composition, alternatively in an amount of 1% to 3.5% by weight of the composition.

[0140] One or more reinforcing fillers (III)

[0141] The one or more reinforcing fillers identified herein as component (III) may be selected, for example, from precipitated silica, fumed silica, precipitated calcium carbonate or a mixture of two or more thereof. Typically, the surface area of ​​the reinforcing filler (III) measured according to the BET method (ISO 9277:2010) is at least 15 m2 in terms of precipitated calcium carbonate. 2 / g, alternatively 15m 2 / g to 50m 2 / g, alternatively 15m 2 / g to 25m 2 / g.

[0142] According to the BET method (ISO 9277:2010), the typical surface area of ​​silica reinforcing fillers is at least 50 m 2 In the case of high surface area fumed silica and / or high surface area precipitated silica, the surface area of ​​these high surface area fumed silica and / or high surface area precipitated silica may be 75 m2 / s as measured according to the BET method (ISO 9277:2010). 2 / g to 400m 2 / g, alternatively 100 m / s measured according to the BET method (ISO 9277:2010) 2 / g to 300m 2 / g.

[0143] The reinforcing filler (III) can be treated with hydrophobic treatment, for example, with one or more aliphatic acids (e.g., fatty acids such as stearic acid, or fatty acid esters such as stearic acid esters), or with organosilanes, organosiloxanes or organosilazane hexaalkyldisilazane or short-chain siloxane diols, so that the filler is hydrophobic and therefore easier to handle and obtain a uniform mixture with other adhesive components. Specific examples of organosilanes, organosiloxanes or organosilazanes include, but are not limited to, silanol-terminated trifluoropropylmethylsiloxane, silanol-terminated vinylmethyl (ViMe) siloxane, silanol-terminated methylphenyl (MePh) siloxane, liquid hydroxydimethyl-terminated polydiorganosiloxanes containing an average of 2 to 20 repeating units of diorganosiloxanes per molecule, hydroxydimethyl-terminated phenylmethylsiloxanes, hexaorganodisiloxanes such as hexamethyldisiloxane, divinyltetrasiloxane, dimethyl ... Methyldisiloxanes; hexaorganodisilazanes such as hexamethyldisilazane (HMDZ), divinyltetramethyldisilazane and tetramethylbis(trifluoropropyl)disilazane; hydroxydimethyl terminated polydimethylmethylvinylsiloxane, octamethylcyclotetrasiloxane and silanes including but not limited to methyltrimethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, trichloromethylsilane.

[0144] The surface treatment of the filler makes it easy to be wetted by component (I). These surface modified fillers are preferably in a finely divided form and do not agglomerate and can be uniformly incorporated into the organosilicon polymer (I). This leads to improved room temperature mechanical properties of the uncured composition. When mixed with component (I), the filler can be pretreated or can be treated in situ. A small amount of water can be added together with a silica treatment agent as a processing aid.

[0145] According to the selected filler, reinforcing filler (III) can be present in an amount of 2.5 % by weight to 60 % by weight (wt.%) of the composition. In the case where the selected filler is precipitated silica and / or pyrogenic silica or a combination thereof, inorganic filler (III) is present in a range of about 5.0 % by weight to 35 % by weight of the composition, alternatively 5 % by weight to 30 % by weight of the composition, alternatively 5 % by weight to 25 % by weight of the composition. However, when reinforcing filler (III) is precipitated calcium carbonate, the composition will tend to comprise a composition of a larger % by weight, such as a composition of 25 % by weight to 60 % by weight, alternatively 30 % by weight to 60 % by weight, alternatively 35 % by weight to 55 % by weight. When component (III) is a mixture of silicon dioxide and precipitated calcium carbonate, % by weight will generally be between them.

[0146] Catalyst (IV) comprising a titanate-based compound, a zirconate-based compound or a mixture thereof

[0147] Component (IV) comprises a condensation catalyst which increases the rate at which the composition cures. The titanate-based and / or zirconate-based catalyst may comprise a catalyst according to the general formula Ti[OR 22 ] 4 OrZr[OR 22 ] 4 A compound in which each R 22 may be identical or different and represent a monovalent primary, secondary or tertiary aliphatic hydrocarbon group, which may be linear or branched and contain 1 to 10 carbon atoms. Optionally, the titanate may contain partially unsaturated groups. However, R 22 Preferred examples include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, and branched secondary alkyl groups such as 2,4-dimethyl-3-pentyl. 22 The same, and R 22 is isopropyl, a branched secondary alkyl group or a tertiary alkyl group, in particular tert-butyl.

[0148] For purposes of illustration, suitable examples include tetra-n-butyl titanate, tetra-tert-butyl titanate, tetra-tert-butoxy titanate, tetra-isopropoxy titanate, and zirconate equivalents.

[0149] Alternatively, titanate / zirconate can be chelated. Chelation can adopt any suitable chelating agent, such as alkyl acetylacetonate, such as methyl acetylacetonate or ethyl acetylacetonate. Alternatively, titanate can be a monoalkoxy titanate with three kinds of chelating agents, such as 2-propanol, triisooctadecanoic acid titanate and diisopropoxy diethyl acetoacetic acid titanate or ethyl acetoacetate titanium complex mixed with methyl-trimethoxysilane. Component (IV) can be present in any suitable amount, such as 0.05 wt % to 1.5 wt % of the composition, alternatively 0.05 wt % to 1.25 wt % of the composition, alternatively 0.1 wt % to 1.0 wt % of the composition, alternatively 0.1 wt % to 0.75 wt % of the composition.

[0150] Optional additives

[0151] If desired, optional additives may be used. These may include non-reinforcing fillers, pigments, chain extenders, tackifiers, rheology modifiers, cure modifiers, desiccants, extenders, flame retardants, plasticizers, end-capping agents, anti-aging additives, UV absorbers, antioxidants, light stabilizers, fungicides and / or biocides, etc., and combinations thereof. It should be understood that some of these additives may be included in more than one additive list. Such additives will then have the ability to function in the different ways involved.

[0152] Non-reinforcing fillers

[0153] Non-reinforcing fillers that may be used in addition to component (III) herein include bauxite, calcium sulfate (anhydrite), gypsum, nepheline, syenite, quartz, calcium sulfate, magnesium carbonate, ground calcium carbonate, clays such as kaolin, alumina trihydrate, magnesium hydroxide (brucite), graphite, copper carbonates such as malachite, nickel carbonates such as trevally, barium carbonates such as witherite, and / or strontium carbonates such as strontianite.

[0154] Alumina, silicates selected from the group consisting of: olivines; garnets; aluminosilicates; cyclosilicates; inosilicates; and sheet silicates. Olivines include silicate minerals such as, but not limited to, forsterite and Mg 2 SiO 4 The garnet class includes ground silicate minerals such as, but not limited to, pyrope; Mg 3 Al 2 Si 3 O 12 ; grossular garnet; and Ca 2 Al 2 Si 3 O 12Aluminosilicates include ground silicate minerals such as, but not limited to, sillimanite; Al 2 SiO 5 ; Mullite; 3Al 2 O 3 .2SiO 2 ; Kyanite; and Al 2 SiO 5 .

[0155] Cyclosilicates include silicate minerals such as, but not limited to, cordierite and Al 3 (Mg,Fe) 2 [Si 4 AlO 18 Inosilicates include ground silicate minerals such as, but not limited to, wollastonite and Ca[SiO 3 ].

[0156] Sheet silicates include silicate minerals such as, but not limited to, mica; 2 AI 14 [Si 6 Al 2 O 20 ](OH) 4 ; Pyrophyllite; Al 4 [Si 8 O 20 ](OH) 4 ; Talc; Mg 6 [Si 8 O 20 ](OH) 4 ; Serpentine, such as asbestos; Kaolinite; Al 4 [Si 4 O 10 ](OH) 8 ; and vermiculite.

[0157] Such additional fillers can also be hydrophobically treated in the same manner as above-mentioned component (III). When present, non-reinforcing fillers tend to be used to replace some components (III), so when component (III) reinforcing filler is precipitated calcium carbonate and non-reinforcing filler is also present in composition, the total amount of precipitated calcium carbonate and non-reinforcing filler will still not exceed the upper limit 60 wt % of composition. In one embodiment of composition, when component (III) is precipitated calcium carbonate, said composition also comprises heavy calcium carbonate. When present, non-reinforcing filler can exist in an amount greater than zero wt % to 20 wt % of composition.

[0158] pigment

[0159] Standard one-part hot porous surface condensation curable silicone compositions can be incorporated herein. Pigments and / or colorants can be colored, white, black, metallic effects and luminescent, such as fluorescent and phosphorescent. Pigments are used to color the composition as desired. Any suitable pigment provided that it is compatible with the composition herein can be used. One-part room temperature vulcanizable (RTV) silicone compositions may contain white pigments and / or colored (non-white) fillers, such as carbon black.

[0160] Typically, the pigment and / or colorant, when particulate, has an average particle size in the range of 10 nm to 50 μm, preferably in the range of 40 nm to 2 μm. When present, the pigment and / or colorant is present in the range of 2 wt%, alternatively 3 wt%, alternatively 5 wt% to 20 wt% of the composition.

[0161] Rheology Modifiers

[0162] Rheology modifiers that can be incorporated into one-part room temperature vulcanizable (RTV) silicone compositions include silicone organic copolymers, such as those described in EP0802233 based on polyether or polyester polyols; nonionic surfactants selected from the group consisting of polyethylene glycols, polypropylene glycols, ethoxylated castor oils, oleic acid ethoxylates, alkylphenol ethoxylates, copolymers of ethylene oxide and propylene oxide, and silicone polyether copolymers; and silicone diols. For some systems, these rheology modifiers, especially copolymers of ethylene oxide and propylene oxide and silicone polyether copolymers, can enhance adhesion to substrates, especially plastic substrates.

[0163] Tackifier

[0164] The one-part room temperature vulcanizable (RTV) silicone composition as described above may also include an aminosilane adhesion promoter having two or three hydroxyl or alkoxy groups per molecule. The aminosilane adhesion promoter having two or three hydroxyl or alkoxy groups per molecule may include:

[0165] R 10 k (R 11 O) 3-k Si-Z 2 -N(H)-(CH 2 ) m‘ -NH 2

[0166] Where R 10 is an alkyl group containing 1 to 10 carbon atoms; each R 11 May be the same or different and be H or R 10 , Z 2is a straight or branched alkylene group having 2 to 10 carbon atoms, m′ is 2 to 10, and k is zero or 1.

[0167] R 10 is an alkyl group containing 1 to 10 carbon atoms, or R 10 is an alkyl group containing 1 to 6 carbon atoms, alternatively R 10 is a methyl group or an ethyl group. 11 can be the same or different, and each R 11 may be the same or different and be H or R or R 10 , alternatively, each R 11 For R 10 In an alternative embodiment, all R 11 The groups are the same. 11 When the groups are the same, it is preferred that they are methyl or ethyl groups. 2 is a straight chain or branched alkylene group having 2 to 10 carbon atoms, alternatively 2 to 6 carbon atoms, for example Z 2 It can be a propylene group, a butylene group or an isobutylene group. There can be 2 to 10 m' groups, in one alternative, m' can be 2 to 6, in another alternative, m' can be 2 to 5, in yet another alternative, m' can be 2 or 3, alternatively m' is 2.

[0168] Other adhesion promoters that may be used include N-(3-(trimethoxysilyl)propyl)butylamine, bis(trimethoxysilylpropyl)amine, bis[3-(triethoxysilyl)propyl]amine, bis[3-(triethoxysilyl)propyl]amine, aminopropyltriethoxysilane, and aminopropyltrimethoxysilane.

[0169] When present, the tackifier is present in an amount from 0.1% to 3.75% by weight of the composition, alternatively from 0.1% to 2.5% by weight of the composition, alternatively from 0.1% to 2.0% by weight of the composition, alternatively from 0.2% to 1.0% by weight of the composition.

[0170] UV and / or light stabilizers

[0171] For purposes of example, the UV and / or light stabilizer may include benzotriazole, ultraviolet light absorber and / or hindered amine light stabilizer (HALS), such as HALS from Ciba Specialty Chemicals Inc. Product series.

[0172] Biocides

[0173] If desired, a biocide may additionally be utilized in the composition. The term "biocide" is intended to include bactericides, fungicides, algaecides, and the like.

[0174] The one-part room temperature vulcanizable (RTV) silicone composition as described above can be prepared by mixing all the ingredients together. Preferably, once mixed, the composition is sealed in one or more moisture-proof containers and stored unless used immediately. In one embodiment, filler (III) and / or pigment are first mixed into polymer (I) when present, optionally, if desired, in combination with a hydrophobic treatment agent, so that the filler and optional pigment can be hydrophobized in situ during mixing into the polymer.

[0175] Once the filler is thoroughly mixed into the polymer (and, if necessary, has been hydrophobized), the remaining components are added in any suitable order to prepare the complete composition.

[0176] For example, in one approach, a method for preparing a one-part room temperature vulcanizable (RTV) silicone composition may include the following steps:

[0177] 1) if deemed necessary, gradually adding the or each reinforcing filler (III) and any non-reinforcing filler (when present) and, if desired, a hydrophobic filler treating agent to the polymer (I) under vacuum for a predetermined period of time; to form a polymer matrix;

[0178] 2) The remaining ingredients are then mixed together to form Premix 1;

[0179] 3) If deemed necessary, then add premix 1 to the polymer base under vacuum and mix into the base;

[0180] 4) Finally, cool the mixture to below 40°C, release the vacuum, and, if stored,

[0181] The final composition is packaged.

[0182] When optional pigments are to be used, they may be introduced prior to or simultaneously with the fillers, thereby producing a pigmented polymer base after completion of step 1 above. Optional ingredients such as tackifiers may also be added to premix 1.

[0183] In step (iii), the one-part room temperature vulcanizable (RTV) silicone composition can be applied to the continuous elastic adhesive film by any suitable means, such as by extrusion, coating, injection, knife coating and rolling, which generally depends on its viscosity and flowability on the continuous elastic adhesive film. Regardless of the application method, it is found that when applied on top of the adhesive intermediate layer, rather than directly applied to the substrate surface at a temperature of 40°C or higher, no bubbles or relatively much fewer bubbles are formed in a standard one-part room temperature vulcanizable (RTV) silicone composition, rather than when the standard one-part room temperature vulcanizable (RTV) silicone composition is applied directly to the hot porous substrate surface at a temperature of at least 40°C, at which time a lot of bubbles form resulting in very poor adhesion. The reduction in the number and size of bubbles in cured silicone sealants is beneficial to the construction industry in hot countries where substrates often reach temperatures in excess of 40°C during the hottest part of the day due to heat from the sun etc., as significant bubble formation with standard sealants has proven to be a major problem in the construction industry as it results in surface bubbling between the curing / cured sealant and the substrate surface, resulting in poor adhesion therebetween. These bubbles are unacceptable and increase the volume of the cured product by up to two or three times compared to a product that has not been cured on a hot porous substrate.

[0184] Another advantage of the present method is that the continuous elastomeric adhesive film protects and insulates the one-part room temperature vulcanizable (RTV) silicone composition from the temperature of the substrate, which allows the user to have increased working time compared to applying the one-part room temperature vulcanizable (RTV) silicone composition directly to the hot porous substrate at 40° C. These compositions tend to cure very quickly at the relevant temperatures because after the one-part room temperature vulcanizable (RTV) silicone composition is applied to the hot porous substrate; it is exposed to atmospheric moisture, causing it to undergo accelerated curing.

[0185] Also provided is a sealed porous substrate as a product of the above method.The one-part room temperature vulcanizable (RTV) silicone composition used herein can be used as a sealant or adhesive, or as a weatherseal or specialty caulking or residential and industrial framing board adhesive and sealant. Example

[0186] All of the above corporate test methods (CTMs) are publicly available from Dow Silicones upon request.

[0187] Various adhesives and primers were evaluated for use as or in the continuous elastic adhesive film as described above. The commercial adhesives used in the examples were:-

[0188] DOWSIL TM 1200OS PrimerIt is a primer for silicone adhesives and sealants, which is a colorless liquid with a viscosity of 1 mPa.s at 23°C, a closed cup flash point of 27°C, a VOC of 76 g / l and a specific gravity of 0.84 at 23°C (all values ​​taken from the data sheet). It does not contain any polymethyl methacrylate.

[0189] DOWSIL TM Primer-C It is a solvent-based silane primer suitable for a variety of applications. It has an 800ft 2 / Gallon(16.33m 2 / L) of non-porous substrate coverage, a specific gravity of 0.90, a color flash point of -4°C, and a VOC content of 1,855 g / L based on the maximum VOC of the California South Coast Air Quality Management District (all values ​​are taken from the data table). It contains about 5% by weight of a methacrylate polymer in the composition.

[0190] DOWSIL TM Building Primer P is a primer in the form of a proprietary alkoxysilane formulation in solvent for masonry surfaces. It is a clear liquid with a specific gravity of 0.95 (ASTM D 1298), a flash point of 8°C (closed cup), a sealer application time of 0.5 to 8 hours at 25°C, and a VOC content of 748 g / L based on the California South Coast Air Quality Management District maximum VOC (all values ​​taken from the data table). It contains about 20% by weight of polyacrylate in the composition.

[0191] DOWSIL TM Building Primer B is a film-forming primer for porous and metal substrates, which is a clear liquid with a specific gravity of 0.97 (ASTM D 1298), a flash point of 26°C (closed cup), a sealant application time of 0.5 hours to 8 hours at 25°C, and a VOC content of 577 g / L based on the maximum VOC of the South Coast Air Quality Management District of California (all values ​​are taken from the data sheet). It contains about 40% by weight of a methacrylate polymer in the composition. Two silicone resin materials are also used:

[0192] DT silicone resin solution The DT silicone resin solution used was a clear / turbid solution having about 70 wt% of DT silicone resin (CTM 0208) in toluene and a viscosity of about 950 mPa.s at 25°C (CTM 0004). The DT silicone resin consists of D units and T units.

[0193] D=(R 4 R 5 SiO 2 / 2 ),T=(R 6 SiO 3 / 2 )

[0194] Contains 0.65 mole fraction of D units (where R4 and R 5 is a methyl group), 0.09 mole fraction of T units (where R 6 is a methyl group) and 0.26 mole fraction of T units (where R 6 is phenyl).

[0195] MQ silicone resin solution The MQ silicone resin solution used was a clear / turbid solution having about 70 wt% of MQ silicone resin (CTM 0208) in xylene with a viscosity of 9 to 13 mPa.s at 25°C (CTM0004). The MQ resin consists of M units and Q units.

[0196] M=(R 1 R 2 R 3 SiO 1 / 2 ) and Q=(SiO 4 / 2 )

[0197] It contains 0.42 mole fraction of M units, of which R 1 , R 2 and R 3 is a methyl group, and 0.58 mole fraction is a Q unit.

[0198] In addition, a binder solution was prepared:

[0199] Polymethyl methacrylate (PMMA) solution The polymethyl methacrylate solution is a 30 wt % solution of polymethyl methacrylate in 70 wt % toluene. The PMMA used in this example and the film is available under the trademark PLEXIGLAS TM 6N solid PMMA beads were commercially available from Rohm, Darmstadt, Germany. Solid PMMA beads were dissolved in toluene in the laboratory to prepare the binder solution. All commercial primers used were commercially available from Dow Silicones, Midland, Michigan, USA.

[0200] In a first series of examples and comparative examples, a granite substrate was first coated with a layer of a continuous elastomeric adhesive film-forming composition at a temperature of about 50°C prior to top coating with a one-part room temperature vulcanizable (RTV) silicone composition, and any resulting blistering that occurred after application of the one-part room temperature vulcanizable (RTV) silicone composition was evaluated. To increase the level of blistering that might occur, the one-part room temperature vulcanizable (RTV) silicone composition was aged at 50°C for a period of two weeks prior to conducting this evaluation, as it has been determined that blistering effects are most pronounced if the applied sealant composition has been stored for a period of time prior to use.

[0201] The granite substrate was heated to about 50°C and cleaned with isopropyl alcohol. Subsequently, the tested adhesive composition was applied by brush and then dried by evaporation of the solvent to obtain an adhesive-coated granite substrate. The adhesive-coated granite substrate was then heated in an oven for 30 minutes to ensure that it was at a temperature of at least 50°C when the sealant composition was applied. The adhesive-coated granite substrate was removed from the oven, the sealant composition was applied on top of the adhesive coating, and then immediately returned to the oven to keep the sealant at about 50°C for the curing process. After curing, each sample was first visually evaluated to observe whether there was obvious surface blistering on the sealant surface, and then the sealant layer was cut from one side to check whether there were bubbles at the interface between the sealant and the substrate.

[0202] Various examples and comparative examples were prepared using two alternative one-part room temperature vulcanizable (RTV) silicone compositions: Formulation 1 was based on a trialkoxysilylethylene terminated polymer and Formulation 2 used a silanol terminated polymer.

[0203] Table 1: One-part room temperature vulcanizable (RTV) silicone compositions (formulated) for Examples 1-11 and Comparative Examples 1-5 The one-part room temperature vulcanizable (RTV) silicone composition (Formulation 2) used in Examples 12-14 and Comparative Example 6 material

[0204] <![CDATA[Form n 1% by weight]]> <![CDATA[Form n 2% by weight]]> Polymer 1 45.44 Polymer 2 32 Polymer 3 13.74 Precipitated Calcium Carbonate (PCC) Filler 45.66 30 Heavy Calcium Carbonate (GCC) 20 Vinylmethyldimethoxysilane 3.65 Methyltrimethoxysilane (MTM) 3.5 Tris(3-trimethoxysilylpropyl isocyanurate 0.25 catalyst 0.82 0.7 Bis(trimethoxysilylpropyl)amine 0.12 3-(2-Aminoethyl)aminopropyltrimethoxysilane 0.08 0.06 pigment 4.00 total 100.00

[0205] Polymer 1 in Table 1 is a trialkoxysilylethylene terminated polydimethylsiloxane having a viscosity of about 60,000 at 25°C;

[0206] Polymer 2 in Table 1 is a dimethylsilanol terminated polydimethylsiloxane having a viscosity of about 50,000 at 25°C;

[0207] Polymer 3 in Table 1 is a trimethyl terminated polydimethylsiloxane having a viscosity of 100 mPa.s at 25°C, which can be obtained from DOWSIL TM 200 fluid was commercially available from Dow Silicones, Midland, Michigan, USA;

[0208] Precipitated calcium carbonate (PCC) filler: PCC is a product of Takehara Kagaku Kogyo Co., Ltd. under the trade name Neolight TM Ultrafine precipitated calcium carbonate coated with fatty acids sold by SP-T;

[0209] The ground calcium carbonate (GCC) filler was type 203A commercially available from Qunxin Powder Technology C. Ltd of Yangzhou, Jiangsu, China; and

[0210] Catalyst: The catalyst is Tyzor TM PITA SM, which is an 80:20 wt % mixture of diisopropoxy-bisethylacetoacetate titanate and methyltrimethoxysilane, is commercially available from Dorf Ketal Speciality Catalysts LLC of Texas USA.

[0211] The viscosity of polymers 1 and 2 was measured according to corporate test method CTM 0050, which is publicly available and based on ASTM D 1084-16 Method B, using a Brookfield DV-III Ultra Rheometer equipped with cone-plate geometry, using spindle 52 at 5 rpm for 2 min.

[0212] Table 1: Comparative Examples (Ref. and C.1-C.2) and Examples of the Invention (Ex.1 and 2) at 50°C using Formulation 1 as The bubbling state of a one-part room temperature vulcanizable (RTV) silicone composition on a granite substrate

[0213]

[0214] The scoring criteria for bubbling status are as follows:

[0215] 1 = no bubbling observed;

[0216] 2 = very small bubbling, no effect on adhesion;

[0217] 3 = some bubbling, which may have a negative effect on adhesion;

[0218] 4 = Significant bubbling observed, negatively affecting adhesion; and

[0219] 5 = Very significant bubbling was observed, with little adhesion (easily peeled off by hand).

[0220] In Reference 1 in Table 2, it will be noted that a high level of bubbling was observed. In Reference 1, the sealant composition of Table 1 was applied directly onto the granite surface. As expected, it was also found that the sealant composition applied directly onto the granite had poor adhesion to the granite and was easily peeled off after curing.

[0221] For comparative examples C.1 and C.2, both substrates were coated with a primer, in C.1 it was DOWSIL TM 1200OS primer, which does not contain a binder, and in C.2 it is DOWSIL TMPrimer-C, which contains about 5% by weight of polymethyl methacrylate. In these cases, the primer coating is very thin considering the lack or low level of binder content. Although the thickness of the coating was not measured, the thickness of the standard primer (non-film-forming) coating applied to the substrate is generally not more than 12.5 μm thick, which is much thinner than the continuous elastic adhesive film layer described herein, which is generally more than 30 μm. It was observed that the coating was discontinuous on the porous substrate and was therefore identified as poor in Table 2, especially when the final product was not a continuous elastic adhesive film. For general primers, especially when some solvents with low boiling points are used in the formulation, although they can enhance the adhesion between the substrate and the sealant, they are essentially insufficient to block the moisture channels through the capillaries in the substrate at elevated temperatures.

[0222] Although not quantified, it appears that the presence of a continuous elastic adhesive film between the hot granite surface and the one-part room temperature vulcanizable (RTV) silicone composition resulted in better adhesion between the hot granite and the resulting silicone sealant at about 50°C, however there was little or no difference with respect to blistering. This suggests that it is not the application of the primer itself to the substrate surface that prevents or minimizes blistering. In contrast, in Ex. 1 and Ex. 2, the one-part room temperature vulcanizable (RTV) silicone composition used to coat the granite surface contained 20 wt.% (DOWSIL TM Building Primer P) and 40 wt% binder (DOWSIL TM The primer of the architectural primer B) prevents or minimizes blistering in the one-part room temperature vulcanizable (RTV) silicone composition when applied over the primer layer.

[0223] A second series of examples was then prepared using Formulation 1 again as the one-part room temperature vulcanizable (RTV) silicone composition, comparing three additional reference examples Ref. 2 to 4, in which the sealant compositions identified in Table 1 were applied directly to three alternative substrates (white marble, granite and limestone) after aging for two weeks at 50°C. These were compared directly to Ex. 3 to 5, in which Primer B was applied to the substrate surface and allowed to dry before applying the one-part room temperature vulcanizable (RTV) silicone composition. As described above, in each case, the film-forming material layer with 40% by weight of polymethyl methacrylate binder prevented or minimized blistering. The results are depicted in Table 3 below.

[0224] Table 2: Ref. 2 to 4 and Examples 3 to 5 using Formulation 1 as a one-part room temperature vulcanizable (RTV) at 50°C Bubbling state of silicone composition on granite

[0225]

[0226]

[0227] In Table 3, WM is white marble, G is granite, and L is limestone. NA stands for not applicable, and Res t Represents elasticity.

[0228] Table 3 shows the alkoxy sealer samples on different types of thermal stone substrates. As shown, without a primer coating, all alkoxy sealers showed numerous bubbling when cured onto the 3 stone substrates, whereas using Primer B as the solvent-based adhesive composition, the resulting continuous elastic adhesive film successfully prevented any bubbling observed on white marble and limestone, and even had little noticeable bubbling on granite.

[0229] As a result of the foregoing results, a third set of examples was conducted using Formulation 1 as the one-part room temperature vulcanizable (RTV) silicone composition to compare three binder solutions with Primer B. The binder solutions used did not contain any additives, they were just a binder and a solvent. Thus, they did not include, for example, any tackifiers or standard primer ingredients. These examples followed the same method as above, and the results are depicted in Table 4 below.

[0230] Table 3: Examples 6 to 8 and Comparative Example 3 using Formulation 1 as a one-part room temperature vulcanizable (RTV) at 50°C Bubbling state of silicone composition on granite substrate

[0231] Ex.6 Ex.7 C.3 Ex.8 Primer / film former type Primer B DT MQ PMMA Adhesive film appearance <![CDATA[Res t ]]> <![CDATA[Res t ]]> crisp <![CDATA[Res t ]]> Description of the bubbling state Almost no bubbles Almost no bubbles Some bubbles Almost no bubbles Scoring of bubbling status 1.2 1.2 3* 1.2

[0232] DT is the above-mentioned DT silicone resin solution. MQ is the above-mentioned MQ silicone resin solution, and PMMA is the above-mentioned PMMA solution.

[0233] It was found that the DT resin film (Ex. 7) obtained by applying the DT resin solution on the granite substrate at 50°C gave a similar TM Similar results were obtained for Architectural Primer B. Again, a continuous elastic adhesive film of PMMA obtained by applying a one-part room temperature vulcanizable (RTV) silicone composition with a 30% PMMA solution (Ex. 8) was applied thereon. This indicates that the presence of the elastic interlayer does manage to prevent the blistering effect. It was also noted that the MQ resin solution of C.3 did not provide an acceptable adhesive film when applied to granite at 50°C. Once dried / cured, the MQ resin coating on the substrate surface provided a brittle and / or powdery coating on the granite substrate. Although it can be seen that the MQ resin coating reduces blistering to some extent, the non-elastic, brittle, powdery layer is not considered suitable for the method herein, especially because the one-part room temperature vulcanizable (RTV) silicone composition does not adhere well thereto and is easily removed.

[0234] Another series of tests were conducted on a granite substrate at 50°C using Formulation 1 as a one-part room temperature vulcanizable (RTV) silicone composition. Ref.3 is a repeat of Ref.1 and 2 and gives similar results, Comparative Example C.4 is a repeat of Comparative Example C.2 and Ex.10 is a repeat of Ex.7. Ex.9 was prepared to show that the introduction of an additional amount of binder (in the form of a 30 wt. % PMMA solution as previously described) into Primer C resulted in reduced foaming. The binder composition used in Ex.9 was prepared by mixing 5 g of Primer C with 10 g of PMMA solution (30%). Ex.11 involves the addition of methyltrimethoxysilane (MTM) to the above-mentioned DT silicone resin. It was prepared by adding 0.5 g of methyltrimethoxysilane to 9.5 g of the above-mentioned DT resin. The results are depicted in Table 5.

[0235] Table 5: Using Formulation 1 as a one-part room temperature vulcanizable (RTV) silicone composition, Examples 9 to 11, Bubbling state of Ref.3 and Comparative Example 4 on 50℃ granite substrate

[0236]

[0237] The results of Table 5 show that in Example 9, when the Primer C and PMMA mixture was mixed and used as a binder composition, much less blistering was observed on the granite substrate at a temperature of 50°C granite when compared to both Ref. 3 and C.4. It can also be seen from Ex. 11 that the addition of MTM, which can be used to improve the adhesion between the DT silicone resin and the substrate surface, if desired, still showed a significant improvement in blister reduction when compared to Ref. 3, and did not significantly increase the amount of blistering when compared to Example 10, thus indicating that adhesion promoting materials can be included in the binder composition if desired / needed to prevent any adhesion issues between the binder and the substrate surface.

[0238] Another set of experiments was conducted using Formulation 2 in the table as the one-part room temperature vulcanizable (RTV) silicone composition. The results are provided in Table 6.

[0239] Table 6: Using Formulation 2 as a one-part room temperature vulcanizable (RTV) silicone composition, Ref. 4 and Example 12 To 14 Bubbling state on 50℃ granite substrate

[0240] Ref.4 Ex.12 Ex.13 Ex.14 Primer / film former type / Primer B PMMA DT resin Adhesive film appearance NA <![CDATA[Res t ]]> <![CDATA[Res t ]]> <![CDATA[Res t ]]> Description of the bubbling state Many bubbles No bubbles Almost no bubbles No bubbles Scoring of bubbling status 5 1 1.5 1

[0241] Ref. 4 shows that applying Formulation 2 to a granite substrate at 50° C. results in the same problem as Refs. 1, 2 and 3, namely a significant blistering problem. However, applying Primer B, PMMA and DT resins in Examples 12 to 14, respectively, to a granite substrate at 50° C. before applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having two hydroxyl groups results in virtually no blistering being observed after applying Formulation 2.

Claims

1. A method of applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups, or combinations thereof and a titanate-based or zirconate-based catalyst to a hot porous substrate at a temperature of at least 40° C., the method comprising the steps of: (i) applying an aqueous or solvent-based binder composition to the surface of a thermally porous substrate at a temperature of at least 40° C., The aqueous or solvent-based binder composition comprises at least 20% by weight of the binder, which is selected from (meth)acrylic resins, poly(meth)acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane, and a silicone resin having the following structure: M (a) D (b) T (c) Q (d) Where a, b, c and d are mole fractions, 0 <a<1,b≥0,c≥0,d≥0,c+d> 0, a+b+c+d=1 and a+d≠1, or a mixture of two or more thereof; (ii) drying and / or curing the aqueous or solvent-based binder composition to allow the binder to coalesce and form a continuous elastic binder film on the thermal porous substrate, and then (iii) applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups selected from alkoxy groups, hydroxyl groups or a combination thereof per molecule and a titanate-based or zirconate-based catalyst onto the surface of the continuous elastic adhesive film and curing it.

2. The method according to claim 1, wherein the thermoporous substrate is selected from stone, marble, brick, concrete, cement and other cementitious substrates.

3. The method according to claim 1 or 2, wherein the solvent is selected from naphtha, toluene, heptane, methyl isobutyl ketone, butyl acetate and xylene, other solvent naphtha, tert-butyl acetate, methyl acetate, ethyl acetate, n-butyl acetate, methyl formate, ethyl formate and any combination thereof.

4. A method according to any preceding claim, wherein the solvent-borne binder composition comprises a non-aqueous solvent and 20% to 75% by weight of the binder in the composition.

5. A method according to any preceding claim, wherein the solvent-borne binder composition is a primer or modified primer containing 20 to 75 wt% of the binder in the composition.

6. A method according to any preceding claim, wherein the binder is a (meth)acrylic resin or a DT silicone resin.

7. A thermally porous substrate sealed at a temperature of at least 40°C, said thermally porous substrate being the product of the process according to claims 1 to 6.

8. A thermally porous substrate sealed at a temperature of at least 40°C, the thermally porous substrate being coated with a cured layer of a one-part room temperature vulcanizable (RTV) silicone composition, the cured layer being obtained or obtainable by the following steps: (i) applying an aqueous or solvent-based binder composition to the surface of a thermally porous substrate at a temperature of at least 40° C., The aqueous or solvent-based binder composition comprises at least 20% by weight of the binder, which is selected from (meth)acrylic resins, poly(meth)acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane, and a silicone resin having the following structure: M (a) D (b) T (c) Q (d) Where a, b, c and d are mole fractions, 0 <a<1,b≥0,c≥0,d≥0,c+d> 0, a+b+c+d=1 and a+d≠1, or a mixture of two or more thereof; (ii) drying and / or curing the aqueous or solvent-based binder composition to allow the binder to coalesce and form a continuous elastic binder film on the thermal porous substrate, and then (iii) applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups selected from alkoxy groups, hydroxyl groups or a combination thereof per molecule and a titanate-based or zirconate-based catalyst onto the surface of the continuous elastic adhesive film and curing it.

9. A thermally porous substrate sealed at a temperature of at least 40°C according to claim 7 or 8, having a continuous elastic adhesive film of at least 30 μm thick.

10. A thermally porous substrate sealed at a temperature of at least 40°C according to any one of claims 7, 8 or 9, wherein the thermally porous substrate is selected from stone, marble, brick, concrete, cement and other cementitious substrates.

11. Use of an aqueous or solvent-based binder composition in a method for applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups or combinations thereof and a titanate-based or zirconate-based catalyst to a thermally porous substrate at a temperature of at least 40° C., the aqueous or solvent-based binder composition comprising at least 20% by weight of the binder selected from (meth)acrylic resins, poly(meth)acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane and a silicone resin having the structure M (a) D (b) T (c) Q (d) When a, b, c and d are mole fractions, 0 <a<1,b≥0,c≥0,d≥0,c+d> 0, a+b+c+d=1 and a+d≠1, or a mixture of two or more thereof, the method comprising the following steps: applying an aqueous or solvent-based binder composition comprising at least 20% by weight of said binder to the surface of a thermally porous substrate at a temperature of at least 40°C; drying and / or curing the aqueous or solvent-based binder composition comprising at least 20% by weight of the binder to allow the binder to coalesce and form a continuous elastic binder film on the thermal porous substrate; and then A one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups per molecule selected from alkoxy groups, hydroxyl groups, or combinations thereof and a titanate-based or zirconate-based catalyst is applied on the surface of the continuous elastic adhesive film and cured.

12. The use according to claim 11, wherein the continuous elastic adhesive film prevents or minimizes the generation of bubbles in the one-part room temperature vulcanizable (RTV) silicone composition when cured on a hot porous substrate at a temperature of at least 40°C.

13. Use of the method according to claims 1 to 6 for weatherproofing thermal porous substrates at temperatures of at least 40°C while preventing or minimizing the generation of bubbles in the one-part room temperature vulcanizable (RTV) silicone composition when cured at a temperature of at least 40°C.

14. Use according to claim 12 or 13, wherein the thermoporous substrate is selected from stone, marble, brick, concrete, cement and other cementitious substrates.

15. A method for filling a space between a first substrate and a second substrate to create a seal therebetween, at least one of the first substrate and the second substrate being a thermally porous substrate at a temperature of at least 40°C, the seal having a cured layer of a one-part room temperature vulcanizable (RTV) silicone composition, the method comprising: (i) applying at least partially an aqueous or solvent-based binder composition to the surface of the thermoporous substrate at a temperature of at least 40° C., The aqueous or solvent-based binder composition comprises at least 20% by weight of the binder, which is selected from (meth)acrylic resins, poly(meth)acrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl butyral, polyurethane, and a silicone resin having the following structure: M (a) D (b) T (c) Q (d) Where a, b, c and d are mole fractions, 0 <a<1,b≥0,c≥0,d≥0,c+d> 0, a+b+c+d=1 and a+d≠1, or a mixture of two or more thereof; (ii) drying and / or curing the aqueous or solvent-based binder composition to allow the binder to coalesce and form a continuous elastic binder film at least on the thermally porous substrate; Then (iii) applying a one-part room temperature vulcanizable (RTV) silicone composition comprising an organopolysiloxane polymer having at least two groups selected from alkoxy groups, hydroxyl groups or a combination thereof per molecule and a titanate-based or zirconate-based catalyst onto the surface of the continuous elastic adhesive film and curing it.

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