Sealant composition

Abstract

This relates to a one-part condensation curable silicone composition, typically a room temperature vulcanisable (RTV) silicone composition comprising a polydiorganosiloxane polymer having at least two hydroxyl or hydrolysable groups per molecule, at least one organosilane cross-linker, a condensation catalyst selected from an alkyltitanate catalyst or an alkylzirconate catalyst and optionally one or more fillers, which composition also comprises and one or more cure accelerating compounds as a means of accelerating the cure of the composition. The cure co-catalyst / reaction accelerator, component (d) is of the following structure (R10)3Si-X2 -N(R9) – X2 – Si(R10)3; where each R10 is independently a methoxy or ethoxy group, each R9 is hydrogen or an alkyl group having from 1 to 4 carbons and each X2 is independently a linear alkyl group having from 1 to 6 carbons.

Description

[0001] SEALANT COMPOSITION

[0002] This relates to a one-part condensation curable silicone composition, typically a room temperature vulcanisable (RTV) silicone composition comprising a polydiorganosiloxane polymer having at least two hydroxyl or hydrolysable groups per molecule, at least one organosilane cross-linker, a condensation catalyst selected from an alkyltitanate catalyst or an alkylzirconate catalyst and optionally one or more fillers, which composition also comprises and one or more cure accelerating compounds as a means of accelerating the cure of the composition.

[0003] One-part condensation curable silicone compositions are well known and are often cured using one or more condensation catalysts selected from alkyltitanate catalysts and / or alkylzirconate catalyst. Such compositions generally comprise a silicone polymer having at least two -OH or hydrolysable groups per molecule, one or more cross-linkers, and said one or more alkyltitanate catalysts and / or alkylzirconate catalysts. They may also contain a variety of additives, in particular fillers dependent on the intended end use.

[0004] A variety of cross-linkers may be utilised to cross-link the silicone polymer having at least two -OH or hydrolysable groups per molecule, to form a cured silicone material for use as e.g. and adhesive or sealant, preferably a cured elastomeric sealant. These are typically cross-linkers are silicon containing materials which contain at least two or three hydrolysable groups per molecule suitable for reacting with the aforementioned polymers. The hydrolysable groups contained in the cross-linker may, for example, be acyloxy groups (for example, acetoxy, octanoyloxy, and benzoyloxy groups); ketoximo groups); alkoxy groups (for example methoxy, ethoxy, and propoxy) and / or alkenyloxy groups (for example isopropenyloxy and l-ethyl-2-methylvinyloxy). However, the standard cross-linkers for compositions being cured using the one or more alkyltitanate catalysts and / or one or more alkylzirconate catalysts are silicon containing materials with containing at least 2 or 3 alkoxy groups per molecule.

[0005] Such one -part condensation curing (RTV) silicone compositions are generally designed not to contain any water / moisture in the composition so far as possible, i.e., they are generally stored in a substantially anhydrous form to prevent premature cure during storage. They are generally utilised to generate skin or diffusion cured silicone elastomers. Skin or diffusion cure (e.g., by moisture / condensation) takes place by the formation of a cured skin at the composition / air interface subsequent to the sealant / encapsulant being applied on to a substrate surface. Subsequent to the generation of the surface skin the cure speed is dependent on the speed of diffusion of moisture from the sealant / encapsulant interface with air to the inside (or core) of the layer of silicone composition applied, and the diffusion of condensation reaction by-product / effluent 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.

[0006] Such one -part condensation curing silicone compositions are applied in a layer that is no thicker than about 15 mm. Such compositions, if applied in layers thicker than 15 mm, are known to lead to uncured material in the depth of the material, because moisture is very slow to diffuse into very deep sections. Given the skin or diffusion cure process the cure speed is quite slow. Historically, the method by which a cured skin is generated at the composition / air interface results in a slow cure process i.e., a slow “skin over time”(SOT) and / or “tack free time” (TFT) and efforts to accelerate cure have concentrated on either increasing catalyst loading or reducing the cross-linker concentration because the kinetics of the crosslinking process is effectively a competition between the crosslinker, catalyst, and polymer end- groups for moisture penetrating the curing sealant from the air / sealant interface such that the less crosslinker present the faster the catalyst and polymer end-groups. Such processes have been extensively explored in the art.

[0007] Furthermore, such sealants are required to adhere to a wide variety of substrates upon cure are insufficiently adhered to some substrates and as such one optional additive often incorporated in the compositions are adhesion promoters, particularly nitrogen containing adhesion promoters. However, many of the preferred adhesion promoters are organosilanes comprising one or more amine groups and while these are known in the industry to improve adhesion, they do so at the cost of slowing down the cure speed i.e. increasing SOT and / or TFT. Hence, they are usually present in such compositions at levels of less than 1.0 wt. % of the composition because at higher levels they are believed to undergo a chelation reaction with the alkyltitanate and / or alkylzirconate catalysts present causing the slowing of the cure process by partially inactivating the catalysts and consequently the SOT the TFT or both the SOT and the TFT can significantly increase. Hence, for product development, minimizing the increase in SOT and / or TFT times while using such amino silanes to increase adhesion to substrates is a challenge not easily achieved. High SOTs and TFTs reduces productivity and efficiency at the jobsite by preventing sealants or coatings to be applied in a timely manner causing the applicators more cost and delay waiting for sealants or coatings to cure, technologies with high tack-free times increases the overall cost of the technology.

[0008] This disclosure solves a known issue for 1-part sealants in which the presence of amine adhesion promoters is known to slowdown a sealant tack-free time. The present disclosure seeks to develop an improved adhesion while accelerating skin over time / tack free time and cure-in-depth of the sealant and / or coating.

[0009] There is provided herein a one-part condensation curable silicone composition comprising:

[0010] (a) an organopolysiloxane polymer having an average of at least two -OH groups or hydrolysable groups per molecule; and a viscosity of from 750 to 150,000mPa.s at 25°C,

[0011] (b) one or more condensation catalysts selected from one or more alkyltitanates, one or more alkylzirconates or a mixture thereof;

[0012] (c) one or more organosilane cross-linkers having at least two alkoxy groups, alternatively at least three alkoxy groups, per molecule;

[0013] (d) a co-catalyst / reaction accelerator of the following structure: (R10)3Si-X2-N(R9) - X2- Si(R10)3; where each R10is independently a methoxy or ethoxy group, each R9is hydrogen or an alkyl group having from 1 to 4 carbons and each X2is independently a linear alkyl group having from 1 to 6 carbons; and optionally

[0014] (e) one or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof. There is also provided a method of accelerating cure of a one-part condensation curable silicone composition comprising introducing one or more co-catalyst / reaction accelerators (d) of the following structure:

[0015] (R10)3Si-X2-N(R9) - X2- Si(R10)3; where each R10is independently a methoxy or ethoxy group, each R9is hydrogen or an alkyl group having from 1 to 4 carbons and each X2is independently a linear alkyl group having from 1 to 6 carbons; into a one -part condensation curable silicone composition otherwise comprising

[0016] (a) an organopolysiloxane polymer having an average of at least two -OH groups or hydrolysable groups per molecule; and a viscosity of from 750 to 150,000mPa.s at 25°C,

[0017] (b) one or more condensation catalysts selected from one or more alkyltitanates, one or more alkylzirconates or a mixture thereof;

[0018] (c) one or more organosilane cross-linkers having at least two alkoxy groups, alternatively at least three alkoxy groups, per molecule; and optionally

[0019] (e) one or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof. There is also provided a use of a co-catalyst / reaction accelerator selected from one or more co- catalyst / reaction accelerators (d) of the following structure (R10)3Si-X2-N(R9) - X2- Si(R10)3; where each R10is independently a methoxy or ethoxy group, each R9is hydrogen or an alkyl group having from 1 to 4 carbons and each X2is independently a linear alkyl group having from 1 to 6 carbons; to accelerate the cure of a one-part condensation curable silicone composition; wherein said one-part condensation curable silicone composition otherwise comprises:

[0020] (a) an organopolysiloxane polymer having an average of at least two -OH groups or hydrolysable groups per molecule; and a viscosity of from 750 to 150,000mPa.s at 25°C,

[0021] (b) one or more condensation catalysts selected from one or more alkyltitanates, one or more alkylzirconates or a mixture thereof;

[0022] (c) one or more organosilane cross-linkers having at least two alkoxy groups, alternatively at least three alkoxy groups, per molecule; and optionally

[0023] (e) one or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof. There is also provided a use of the aforementioned one-part condensation curable silicone composition as a sealant in construction applications such as in facade, insulated glass, and window and door construction applications.

[0024] The concept of “comprising” where used herein is used in its widest sense to mean and to encompass the notions of “include” and “consist of’.

[0025] The compositions described above are preferably room temperature vulcanisable (RTV) compositions in that they cure at room temperature without heating but may, if deemed appropriate, have cure accelerated by heating. The total amount of any composition provided in terms of wt. % is 100 wt. %.

[0026] It was unexpectedly found that when included in the formulation of the composition, component (d) substantially decreased the cure time of the sealant compared to when using a standard amount of one or more alkyltitanates, one or more alkylzirconates or a mixture thereof (component (b). Thus, the introduction of component (ed into such sealant compositions can allow for the preparation of sealants with very fast cure times to match or outperform fast cure oxime sealant compositions. Alternatively, the introduction of component (d) can allow for a decrease in the content of the one or more alkyltitanates, one or more alkylzirconates or a mixture thereof (component (b) in the composition thereby maintaining good surface cure while obtaining improved performance (stability, adhesion, shelf life in view of the reduction in the one or more alkyltitanates, one or more alkylzirconates or a mixture thereof, component (b).

[0027] The one-part condensation curable silicone composition provided herein comprises the following components:

[0028] Component (a): an organopolysiloxane polymer having an average of at least two -OH groups or hydrolysable groups per molecule; and a viscosity of from 750 to 150,000mPa.s at 25°C

[0029] Component (a) may be any suitable an organopolysiloxane polymer having an average of at least two - OH groups or at least two hydrolysable groups per molecule or a mixture thereof; and a viscosity of from 750 to 150,000mPa.s at 25°C; alternatively, any suitable organopolysiloxane polymer having at least two -OH groups or at least two hydrolysable groups per molecule or a mixture thereof; at least two -OH groups or hydrolysable groups per molecule; and a viscosity of from 750 to 150,000mPa.s at 25°C.

[0030] The at least two -OH groups or at least two hydrolysable groups per molecule or a mixture thereof are preferably silicon bonded groups and may be, but are not necessarily, terminal groups. In one embodiment, the hydrolysable groups are alkoxy groups having from one to 10 carbons. Illustrative alkoxy groups are methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, t-butoxy, isobutoxy, pentoxy, hexoxy and 2-ethylhexoxy; dialkoxy groups, such as methoxymethoxy or ethoxymethoxy an alkoxyaryloxy, such as ethoxyphenoxy groups. Alternatively, the alkoxy groups may contain from 1 to 6 carbons i.e., a methoxy, ethoxy, propoxy, isopropoxy, n-butoxy or t-butoxy group.

[0031] For example, the organopolysiloxane polymer having an average of at least two -OH groups or at least two hydrolysable groups per molecule or a mixture thereof (a), of the one-part condensation curable silicone composition described herein, may have the formula:

[0032] Xa-nRnSi-Z- (R ySiOi l-yj / z) / — SiR1-Z-Si-RnXi-n (1) in which each X is independently an OH or an alkoxy group, each R is an alkyl, alkenyl or aryl group, each R1is an OH group an alkoxy group, an alkyl group, an alkenyl group or an aryl group and Z is oxygen or a divalent organic group, typically containing from 2 to 10 carbons; each n is independently 0, 1, 2 or 3, y is 0, 1 or 2, preferably 2 and z is an integer consistent with said organopolysiloxane polymer having a viscosity of from 750 to 150,000mPa.s at 25°C.

[0033] In the above formula each X is independently an OH or an alkoxy group, alternatively an alkoxy group having from 1 and 10 carbons. Illustrative alkoxy groups are methoxy, ethoxy, propoxy, isopropoxy, n- butoxy, t-butoxy, isobutoxy, pentoxy, hexoxy and 2-ethylhexoxy; dialkoxy groups, such as methoxymethoxy or ethoxymethoxy an alkoxyaryloxy, such as ethoxyphenoxy groups; alternatively, each X is an alkoxy group having from one and six carbons, alternatively having from one and four carbons i.e., methoxy, ethoxy, propoxy, isopropoxy, n-butoxy or t-butoxy group or alternatively is a methoxy or ethoxy group.

[0034] Each R group is an alkyl, alkenyl or aryl group, alternatively each R is an alkyl group having from 1 to 6 carbons, an alkenyl group having from 2 to 6 carbons such as vinyl, allyl and hexenyl groups or an aryl group having from 6 to 12 carbons; alternatively, each R is an alkyl group having from 1 to 6 carbons, or an aryl group having from 6 to 12 carbons; alternatively each R is an alkyl group having from 1 to 6 carbons, alternatively each R is an ethyl group or a methyl group. In one embodiment R may include substituted aliphatic organic groups such as 3,3,3-trifluoropropyl groups aminoalkyl groups, polyaminoalkyl groups, and / or epoxyalkyl groups.

[0035] Each R1is an OH group an alkoxy group, alkyl group, alkenyl group or aryl group. For the avoidance of doubt this means that cumulatively at least two X groups, at least two R1groups or at least one X group and one R1group per molecule are OH groups or alkoxy groups, preferably alkoxy groups.

[0036] It is possible that some R1groups may be siloxane branches off the polymer backbone which branches may have terminal X groups as hereinbefore described.

[0037] Each Z may be the same of different and is oxygen or a divalent organic group. When Z is a divalent organic group, it is typically an alkylene having from 2 to 10 carbons, such as for example, an ethylene, propylene, butylene, pentylene and / or hexylene group; alternatively, an alkylene group having 2 to 6 carbons, alternatively an alkylene group having from 2 to 5 carbons. The alkylene group may contain branching.

[0038] Each subscript n is zero 1, 2 or 3, alternatively each subscript n is 0, 1 or 2, alternatively each subscript n is 0 or 1. In one embodiment each n is zero and each Z is an alkylene having from 2 to 10 carbons.

[0039] Each subscript y is 0, 1 or 2, and is preferably 2. Whilst y is 0, 1 or 2, substantially y= 2, e.g., at least 90%, alternatively 95% of R’ySiO(4-y) / 2 groups are characterized with y = 2.

[0040] Subscript z is an integer such that said organopolysiloxane polymer has a viscosity of from 750 to 150,000mPa.s at 25 °C therefore z is an integer of from approximately 50 to 2000, alternatively z is an integer from about 70 to 1000.

[0041] The Degree of Polymerization (DP), (i.e., in the above formula substantially z), is usually defined as the number of monomeric units in a macromolecule or polymer or oligomer molecule of silicone. Synthetic polymers invariably consist of a mixture of macromolecular species with different degrees of polymerization and therefore of different molecular weights. There are different types of average polymer molecular weight, which can be measured in different experiments. The two most important are the number average molecular weight (Mn) and the weight average molecular weight (Mw). The Mn and Mw of a silicone polymer can be determined by gel permeation chromatography (GPC) with precision of about 10-15% using polystyrene standards.

[0042] This technique is standard and yields Mw, Mn and polydispersity index (PI). The degree of polymerization (DP) =Mn / Mu where Mn is the number-average molecular weight coming from the GPC measurement and Mu is the molecular weight of a monomer unit. PI=Mw / Mn. The DP is linked to the viscosity of the polymer via Mw, 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 (a) herein may, for example, be determined using a Waters 2695 Separations Module equipped with a vacuum degasser, and a Waters 2414 refractive index detector (Waters Corporation of MA, USA). The analyses may then be performed using certified grade toluene flowing at 1.0 mL / min as the eluent. Data collection and analyses may be performed using Waters Empower GPC software.

[0043] The viscosity of component (a) is from 750 to 15O,O0OmPa.s at 25°C, alternatively from 1000 to 125,000mPa.s at 25°C, alternatively 10,000 to 100,000mPa.s at 25°C, alternatively 20,000 to 80,000mPa.s at 25°C. The viscosity of component (a) may be measured at 25°C in accordance with the ASTM D4287 Cone and Plate Method using a Brookfield DV-III Ultra Rheometer. Alternatively the viscosity can be measured using a Brookfield DV-II Viscometer in accordance with ASTM D2196 using Spindle 4 at 6 rpm.

[0044] The organopolysiloxane polymer (a) described above is present in the one -part condensation curable silicone composition in an amount of from 30 to 90 weight % (wt. %) of the composition. Alternatively, 30 to 80 wt. % of the composition alternatively 35 to 80 wt. % of the composition. Organopolysiloxane polymer (a) can be a single siloxane represented by Formula (1) or it can be mixtures of organopolysiloxane polymers represented by the aforesaid formula. Hence, it may be a "siloxane polymer mixture" so organopolysiloxane polymer (a) is meant to include any individual organopolysiloxane polymer (a) or mixtures of organopolysiloxane polymer (a).

[0045] Component (b) one or more condensation catalysts selected from one or more alkyltitanates, one or more alkylzirconates or a mixture thereof

[0046] Any suitable alkyltitanates and / or alkylzirconates which act as condensation catalysts may be utilised. The alkyltitanate catalysts and alkylzirconate catalysts of the one or more condensation catalysts may comprise compounds according to the general formula:

[0047] M[OR7]4

[0048] Where M is titanium or zirconium and each R7may be the same or different and represents a monovalent, primary, secondary or tertiary aliphatic hydrocarbon group which may be linear or branched containing from 1 to 10 carbon atoms. Such titanates and zirconates are sometimes respectively referred to as tetraalkoxy titanium or tetraalkoxy zirconium catalysts.

[0049] Typically, each R7may be the same or different and include but are not restricted to methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl, tertiary amyl (C (C2H5) (CHsU). pentyl or hexyl groups and branched secondary alkyl groups such as 2,4-dimethyl-3-pentyl groups. In some embodiments one or more R7groups may contain partial unsaturation. In one embodiment all the R7are the same alkyl group. Examples include the following titanates and their zirconate equivalents:

[0050] Ti (OCfCHsKB tetraisopropyltitanate or tetraisopropoxy titanium (TiPT), Ti[OC(CHs)3]4 - tetratertiary butyl titanate or tetratertiarybutoxy titanium (TtBT) Ti (C (C2H5) (CHilzJi - tetrateriary amyl titanate

[0051] T^OCHiCHiCHzCHsU - tetra n-butyl titanate or tetra n-butoxy titanium (TnBT) And other suitable alkyltitanate catalysts such as Tyzor™ 9000 commercially available from Dorf Ketal Speciality Catalysts, LLC which has has the formula:

[0052] Ti [isopropoxy],- [t-butoxy]b’ where the total number of [isopropoxy] + [tertiary butoxy] groups per Ti atom (a’ + b’) is 4 and wherein, on average there are about 10% [isopropoxy] and 90% [t-butoxy] groups.

[0053] Alternatively, the titanate and / or zirconate may be at least partially chelated. The chelation may be with any suitable chelating agent which enhances the catalytic activity of the catalyst e.g., an alkyl acetoacetate such as methyl acetoacetate or ethylacetylacetonate. An example being diisopropoxy titanium bis(ethylacetoacetate or titanium(IV) bis(ethyl acetoacetato)diisopropoxide (TDIDE).

[0054] Said alkyltitanate, alkylzirconate or mixture thereof of the condensation catalyst of component (b) herein being present in the composition in an amount of from 0.01 to 1.5 wt. % of the composition, alternatively from 0.1 to 1.5 wt.% of the composition, alternatively 0.25 to 1.5 wt.% of the composition, alternatively 0.5 to 1.5 wt.% of the composition.

[0055] Component (c): One or more organosilane cross-linkers having at least two alkoxy groups, alternatively at least three alkoxy groups, per molecule.

[0056] Component (c) is one or more organosilane cross-linkers having at least two alkoxy groups, alternatively at least three alkoxy groups, per molecule. Component (c) as defined herein does not include any amine groups and the term “organosilanes” is considered to incorporate tetraalkoxy silanes, but does not include any compounds with an -Si-O-Si siloxane linkage.

[0057] Component (c) is effectively functioning as a cross-linker and as such requires a minimum of 2 alkoxy groups per molecule and preferably 3 or more. Component (c) may have two alkoxy groups when component (a) has three or more hydrolysable groups per molecule. Component (c) may thus have two but alternatively has three or more silicon-bonded alkoxy groups per molecule which are reactive with the hydrolysable groups in component (a).

[0058] Typically, component (c) may be: one or more organosilanes having at least 2 alkoxy groups, alternatively at least 3 alkoxy groups per molecule group; and / or one or more silyl functional molecules having at least 2 silyl groups, each silyl group containing at least one alkoxy group.

[0059] For the sake of the disclosure herein a disilyl functional molecule comprises two silicon atoms each having at least one hydrolysable group, where the silicon atoms are separated by an organic chain and do not contain any -Si-O-Si- linkages. Typically, each silyl group on the disilyl functional molecule are terminal groups. The organic chain may be a polymeric chain such as an alkylene chain having from 2 to 10 carbons.

[0060] The alkoxy groups on the silyl groups may be selected from alkoxy groups (for example methoxy, ethoxy, and propoxy) and alkenyloxy groups (for example isopropenyloxy and l-ethyl-2- methylvinyloxy). Alternatively, said hydrolysable groups on the silyl groups are selected from alkoxy groups and / alkenyloxy groups. When component (c) is an organosilane, said organosilanes may include alkoxy functional organosilanes, including tetraalkoxysilanes. Preferably, when component (c) is an organosilane, said organosilanes may include alkoxy functional organosilanes,

[0061] When component (c) is an organosilane and when the organosilane has only three silicon-bonded alkoxy groups per molecule, the fourth group is suitably a non-hydrolysable silicon-bonded organic group. These silicon-bonded organic groups are suitably hydrocarbyl groups which are optionally substituted by halogen such as fluorine and chlorine. Examples of such fourth groups include alkyl groups (for example methyl, ethyl, propyl, and butyl); cycloalkyl groups (for example cyclopentyl and cyclohexyl); alkenyl groups (for example vinyl and allyl); aryl groups (for example phenyl, and tolyl); aralkyl groups (for example 2-phenylethyl) and groups.

[0062] A typical organosilane of component (c) may be described by formula (8)

[0063] R"4-rSi(R5), (8) wherein R5is an alkoxy group, R” is an alkyl groups (for example methyl, ethyl, propyl, and butyl); cycloalkyl groups (for example cyclopentyl and cyclohexyl); alkenyl groups (for example vinyl and allyl); aryl groups (for example phenyl, and tolyl); aralkyl groups (for example 2-phenylethyl) .and r has a value of 2, 3 or 4.

[0064] In formula (8) R5is a suitable alkoxy group as defined as X above, for example an alkoxy group having from 1 and 10 carbons. Illustrative alkoxy groups are methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, t- butoxy, isobutoxy, pentoxy, hexoxy and 2-ethylhexoxy; dialkoxy groups, such as methoxymethoxy or ethoxymethoxy an alkoxyaryloxy, such as ethoxyphenoxy groups; alternatively, each R5is an alkoxy group having from one and six carbons, alternatively having from one and four carbons i.e., methoxy, ethoxy, propoxy, isopropoxy, n-butoxy or t-butoxy group or alternatively is a methoxy or ethoxy group; and

[0065] R” is selected from an alkyl group, cycloalkyl groups; alkenyl group, aryl group or aralkyl group. In one embodiment R” is an alkyl group having from 1 to 6 carbons, such as methyl, ethyl, propyl, isopropyl, n- butyl and t-butyl; cyclopentyl and cyclohexyl; an alkenyl group having from 2 to 6 carbons such as vinyl and allyl; a phenyl, and tolyl or 2-phenylethyl). In one embodiment R” represents methyl, ethyl or vinyl or isopropyl or t-butyl.

[0066] In a further embodiment component (c) is a silyl functional molecule having at least 2 silyl groups each having at least 1 and up to 3 hydrolysable groups, alternatively each silyl group has at least 2 hydrolysable groups.

[0067] Component (c) may be a disilyl functional polymer, that is, a polymer backbone having two silyl groups, each containing at least one alkoxy group with the backbone being a polyether or alkylene backbone. Component (c) thus include alkyltrialkoxysilanes such as methyltrimethoxysilane (MTM) and methyltriethoxysilane, tetraethoxysilane, partially condensed tetraethoxysilane, alkenyltrialkoxy silanes such as vinyltrimethoxysilane and vinyltriethoxysilane, isobutyltrimethoxysilane (iBTM). Other suitable silanes include ethyltrimethoxy silane, vinyltriethoxysilane, phenyltrimethoxy silane, 1,6- bis(trimethoxysilyl)hexane (comparative 4 in the examples below). The component (c) used may also comprise any combination of two or more of the above.

[0068] Said one or more organosilane cross-linkers having at least 3 hydroxyl and / or hydrolysable groups per molecule (c), when present, may be selected from an organosilane having the structure

[0069] R' Si ( ( )R ' ; :

[0070] As mentioned previously where each R5may be the same or different and is hydrogen or an alkyl group containing at least one carbons, alternatively from 1 to 20 carbons, alternatively from 1 to 10 carbons alternatively from 1 to 6 carbons. The value of j is 0 or 1. Whilst each R5group may be the same of different it is preferred that at least two R5groups are the same, alternatively at least three R5groups are the same and alternatively when j is 0 all R5groups are the same. Hence, specific examples of the reactive organosilane (c) when j is zero include tetraethylorthosilicate,

[0071] When j is 1 the group R8is present. R8is a silicon-bonded organic group selected from straight or branched monovalent hydrocarbon group having at least one carbon, a cycloalkyl group, an aryl group, or an aralkyl group. The unsubstituted monovalent hydrocarbon groups, suitable as R8, may include alkyl groups e.g., methyl, ethyl, propyl, and other alkyl groups, alkenyl groups such as vinyl, cycloalkyl groups may include cyclopentane groups and cyclohexane groups.

[0072] Specific examples of suitable organosilane cross-linkers (c), include but are not limited to vinyl trimethoxy silane, methyltrimethoxysilane, ethyltriethoxysilane, ethyltrimethoxysilane, propyltriethoxysilane, isobutyltrietho xysilane, isobutyltrimethoxysilane, vinyltriethoxysilane, phenyltriethoxy silane, phenyltrimethoxysilane, methyltris(isopropenoxy)silane or vinyltris(isopropenoxy)silane.

[0073] The organosilane cross-linkers (c) is present in an amount of from 0.1 to 10 wt. % of the composition, alternatively from 0.5 to 7.5 wt. % of the composition, alternatively present in an amount of from 0.75 to 5 wt. % of the composition, alternatively in an amount of from 0.75 to 4.0wt. % of the composition. Component (c) and component (e) are different.

[0074] Component (d) co-catalyst / reaction accelerator

[0075] The co-catalyst / reaction accelerator (d) in the one-part condensation curable silicone composition is one or more co-catalyst / reaction accelerators of the following structure

[0076] (R10)3Si-X2-N(R9) - X2- Si(R10)3; where each R10is independently a methoxy or ethoxy group, each R9is hydrogen or an alkyl group having from 1 to 4 carbons and each X2is independently a linear alkyl group having from 1 to 6 carbons. R9is hydrogen or an alkyl group having from 1 to 4 carbons for example, methyl, ethyl, n-propyl, isopropyl, n-butyl and t-butyl, alternatively R9is a hydrogen or a methyl or ethyl group, alternatively R9is hydrogen or a methyl group, each X2is independently a linear alkyl group having from 1 to 6 carbons such as methyl, ethyl, n-propyl, n-butyl and n-pentyl

[0077] Specific examples of component (d) include: bis (3-trimethoxysilylpropyl)amine, bis (3-triethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-N-methylamine, bis(3-triethoxysilylpropyl)-N-methylamine, bis(3-trimethoxysilylpropyl)-N-ethylamine, bis(3-triethoxysilylpropyl)-N-ethylamine, bis(3-trimethoxysilylpropyl)-N-propylamine, bis(3-triethoxysilylpropyl)-N-propylamine, bis(3-trimethoxysilylpropyl)-N-isopropylamine, bis(3-trimethoxysilylpropyl)-N-isopropylamine, bis(3-trimethoxysilylpropyl)-N-butylamine, bis(3-triethoxysilylpropyl)-N-butylamine, bis(3-trimethoxysilylpropyl)-N-t-butylamine or bis(3-triethoxysilylpropyl)-N-t-butylamine.

[0078] In the above the propyl group may be replaced with other alkyl groups as defined by X2groups such as for example ethyl or n-butyl groups Alternatively, component (d) is bis (3-trimethoxysilylpropyl)amine, bis (3-triethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-N-methylamine, bis(3-triethoxysilylpropyl)-N-methylamine, bis(3-trimethoxysilylpropyl)-N-ethylamine or bis(3-triethoxysilylpropyl)-N-ethylamine. Alternatively, component (d) is bis (3-trimethoxysilylpropyl)amine, bis (3-triethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-N-methylamine or bis(3-triethoxysilylpropyl)-N-methylamine. Alternatively, component (d) is bis (3-trimethoxysilylpropyl)amine or bis(3-trimethoxysilylpropyl)-N-methylamine.

[0079] Component (d) is present in the composition in an amount of from 0.075 to 5.0 wt. % of the composition, alternatively from 0.075 to 4.0 wt. % of the composition, alternatively from 0.075 to 2.0 wt. % of the composition.

[0080] Component (e) One or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof (optional)

[0081] Component (e), when present, may include one or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof. The one or more reinforcing fillers which may be present in the composition as component (e) herein may for example be selected from precipitated silica, fumed silica, precipitated calcium carbonate, or a mixture of two or more thereof. Typically, the surface area of the reinforcing filler (e) is at least 15 m2 / g in the case of precipitated calcium carbonate measured in accordance with the BET method (ISO 9277: 2010), alternatively 15 to 50 m2 / g, alternatively 15 to 25 m2 / g.

[0082] Silica reinforcing fillers have a typical surface area of at least 50 m2 / g in accordance with the BET method (ISO 9277: 2010). In the case of high surface area fumed silica and / or high surface area precipitated silica, these may have surface areas of from 75 to 400 m2 / g measured in accordance with the BET method (ISO 9277: 2010), alternatively of from 100 to 300 m2 / g in accordance with the BET method (ISO 9277: 2010).

[0083] The reinforcing fillers (e) which may be present in the one-part condensation curable silicone composition may be hydrophobically treated for example with one or more aliphatic acids, e.g., a fatty acid such as stearic acid or a fatty acid ester such as a stearate, or with organosilanes, organosiloxanes, or organosilazanes hexaalkyl disilazane or short chain siloxane diols to render the filler) s) hydrophobic and therefore easier to handle and obtain a homogeneous mixture with the other adhesive components.

[0084] Specific examples organosilanes, organosiloxanes, or organosilazanes may include, but are not restricted to, silanol terminated trifluoropropylmethylsiloxane, silanol terminated vinyl methyl (ViMe) siloxane, silanol terminated methyl phenyl (MePh) siloxane, liquid hydroxyldimethyl-terminated polydiorganosiloxane containing an average from 2 to 20 repeating units of diorganosiloxane in each molecule, hydroxyldimethyl terminated phenylmethyl Siloxane, hexaorganodisiloxanes, such as hexamethyldisiloxane, divinyltetramethyldisiloxane; hexaorganodisilazanes, such as hexamethyldisilazane (HMDZ), divinyltetramethyldisilazane and tetramethyldi(trifluoropropyl)disilazane; hydroxyldimethyl terminated polydimethylmethylvinyl siloxane, octamethyl cyclotetrasiloxane, and silanes including but not limited to methyltrimethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, chlorotrimethyl silane, dichlorodimethyl silane, trichloromethyl silane.

[0085] The surface treatment of the fillers makes them easily wetted by component (a). These surface modified fillers are preferably in a finely divided form and do not clump and can be homogeneously incorporated into the silicone polymer (a). This results in improved room temperature mechanical properties of the uncured compositions. The fillers may be pre-treated or may be treated in situ when being mixed with component (a). A small amount of water can be added together with the silica treating agent(s) as processing aid.

[0086] Depending on the filler(s) chosen (when present) the reinforcing fillers of component (e) may be present in an amount of from 2.5 to 60 wt. % of the composition. In the case when the selected fillers are precipitated silica and / or fumed silica or a combination thereof the inorganic fillers (e) are present in a range of from about 5.0 to 35 wt. % of the composition, alternatively of from 5 to 30 wt. % of the composition, alternatively of from 5 to 25 wt. % of the composition.

[0087] However, when reinforcing filler of component (e) is precipitated calcium carbonate, the composition will tend to include a larger wt. % of the composition, e.g., from 10 to 60 wt. % of the composition, alternatively of from 30 to 60 wt. % of the composition, alternatively of from 35 to 55 wt. % of the composition. When component (e) is a mixture of silica and precipitated calcium carbonate the wt. % will typically somewhere therebetween.

[0088] Non-reinforcing fillers

[0089] The one or more non-reinforcing fillers which may be present in the composition as component (e) herein, may be selected from one or more of the following aluminite, calcium sulphate (anhydrite), gypsum, nepheline, syenite, ground calcium carbonate, quartz, calcium sulphate, magnesium carbonate, clays such as kaolin, aluminium trihydroxide, magnesium hydroxide (brucite), graphite, copper carbonate, e.g., malachite, nickel carbonate, e.g., zarachite, barium carbonate, e.g., witherite and / or strontium carbonate e.g., strontianite.

[0090] Silicates from the group consisting of olivine group; garnet group; aluminosilicates; ring silicates; chain silicates; and sheet silicates. The olivine group comprises silicate minerals, such as but not limited to, forsterite and Mg2SiC>4. The garnet group comprises ground silicate minerals, such as but not limited to, pyrope; MgiAfSi iOi ; grossular; and Ca2A12SisOi2. Aluminosilicates comprise ground silicate minerals, such as but not limited to, sillimanite; AhSiCh; mullite; 3A12Oa.2SiO2; kyanite; and AfSiO-,. The ring silicates group comprises silicate minerals, such as but not limited to, cordierite and A13(M ,Fe)2[Si4AlOis]. The chain silicates group comprises ground silicate minerals, such as but not limited to, wollastonite and CafSiOs].

[0091] The sheet silicates group comprises silicate minerals, such as but not limited to, mica; K2AIi4[Si6A12O2n](OH)4; pyrophyllite; AFCSisCFoKOH^; talc; MgetSisCFoKOHh; serpentine for example, asbestos; Kaolinite; A14[Si40io](OH)s; and vermiculite.

[0092] The non-reinforcing fillers of component (e), when present, may also be hydrophobically treated as described above. And when present may be present in amounts up to about 60 wt. % of the composition but typically are found in lower amounts in combination with some reinforcing filler. In a preferred embodiment the one -part condensation curable silicone composition as described herein contains one or more fillers as described in component (e), typically when present the fillers contain minimal moisture content.

[0093] Optional Additives

[0094] The one-part condensation curable silicone composition as hereinbefore described may comprise a variety of additives. The additives may include, but are not limited to, rheological modifiers, water / moisture scavengers, plasticizers and / or extenders, pigments & colorants, antioxidants, UV and / or light stabilizers and biocides.

[0095] Rheology modifiers

[0096] Rheology modifiers which may be incorporated in the one-part condensation curable silicone composition as described above include silicone organic co-polymers such as those described in EP0802233 based on polyols of polyethers or polyesters; non-ionic surfactants selected from the group consisting of polyethylene glycol, polypropylene glycol, ethoxylated castor oil, oleic acid ethoxylate, alkylphenol ethoxylates, copolymers or ethylene oxide and propylene oxide, and silicone polyether copolymers; as well as silicone glycols. For some systems these rheology modifiers, particularly copolymers of ethylene oxide and propylene oxide, and silicone polyether copolymers, may enhance the adhesion to substrates, particularly plastic substrates.

[0097] Moisture / water scavenger

[0098] Any suitable -OH (moisture / water / alcohol) scavenger may be used in the one-part condensation curable silicone composition when required given catalyst (b) is one or more alkyltitanates, one or more alkylzirconates or a mixture thereof. When present with alkyltitanates and / or alkyl zirconates these are usually nitrogen-free alkoxysilanes or the like, because nitrogen containing species such as silazanes e.g., hexamethyldisilazane (HMDZ) often deactivate the alkyltitanates and alkylzirconates.

[0099] One or more plasticizer(s), one or more extender(s) or a mixture thereof

[0100] The one-part condensation curable silicone composition as described above may also include one or more plasticizer(s), one or more extender(s) or a mixture thereof.

[0101] These may be in the form of silicone or organic fluids which are unreactive with any of components (a) or (c) to (e) above. If present the plasticizer or extender content will be present in an amount of from 2.5 to 30 wt. % of the composition, alternatively from 2.5 to 20 wt. % or the composition alternatively from 2.5 to 15 wt. % or the composition. Examples of non-reactive silicone fluids useful as plasticizers include polydiorganosiloxanes such as polydimethylsiloxane having terminal triorganosiloxy groups wherein the organic substituents are, for example, methyl, vinyl or phenyl or combinations of these groups. Such polydimethylsiloxanes can for example have a viscosity of from about 5 to about 100,000 mPa.s at 25°C (measured as described above). Alternatively compatible organic plasticisers may be utilised additionally to or instead of the silicone fluid plasticiser. These may include dialkyl phthalates wherein the alkyl group may be linear and / or branched and contain from six to 20 carbon atoms such as dioctyl, dihexyl, dinonyl, didecyl, diallanyl and other phthalates, and analogous adipate, azelate, oleate and sebacate esters; polyols such as ethylene glycol and its derivatives; and organic phosphates such as tricresyl phosphate and / or triphenyl phosphates.

[0102] Examples of extenders for use in compositions herein include mineral oil based (typically petroleum based) paraffinic hydrocarbons, mixtures of paraffinic and naphthenic hydrocarbons, paraffin oils comprising cyclic paraffins and non-cyclic paraffins and hydrocarbon fluids containing naphthenics, polycyclic naphthenics and paraffins, or polyalkylbenzenes such as heavy alkylates (alkylated aromatic materials remaining after distillation of oil in a refinery). Examples of such extenders are discussed in GB2424898 the content of which is hereby enclosed by reference.

[0103] Pigments and / or colorants

[0104] The one-part condensation curable silicone composition as described above may further comprise one or more pigments and / or colorants. The pigments and / or colorants may be coloured, white, black, metal effect, and luminescent e.g., fluorescent or phosphorescent. Pigments are utilized to colour the composition as required. Any suitable pigment may be utilized providing it is compatible with the composition herein.

[0105] Suitable white pigments and / or colorants include titanium dioxide, zinc oxide, lead oxide, zinc sulfide, lithophone, zirconium oxide, and antimony oxide.

[0106] Suitable non-white inorganic pigments and / or colorants include, but are not limited to, iron oxide pigments such as goethite, lepidocrocite, hematite, maghemite, and magnetite black iron oxide, yellow iron oxide, brown iron oxide, and red iron oxide; blue iron pigments; chromium oxide pigments; cadmium pigments such as cadmium yellow, cadmium red, and cadmium cinnabar; bismuth pigments such as bismuth vanadate and bismuth vanadate molybdate; mixed metal oxide pigments such as cobalt titanate green; chromate and molybdate pigments such as chromium yellow, molybdate red, and molybdate orange; ultramarine pigments; cobalt oxide pigments; nickel antimony titanates; lead chrome; carbon black (when present, carbon black will function as both a non-reinforcing filler and colorant); lampblack, and metal effect pigments such as aluminium, copper, copper oxide, bronze, stainless steel, nickel, zinc, and brass.

[0107] Suitable organic non-white pigments and / or colorants include phthalocyanine pigments, e.g., phthalocyanine blue and phthalocyanine green; monoarylide yellow, diarylide yellow, benzimidazolone yellow, heterocyclic yellow, DAN orange, quinacridone pigments, e.g., quinacridone magenta and quinacridone violet; organic reds, including metallized azo reds and nonmetallized azo reds and other azo pigments, monoazo pigments, diazo pigments, azo pigment lakes, -naphthol pigments, naphthol AS pigments, benzimidazolone pigments, diazo condensation pigment, isoindolinone, and isoindoline pigments, polycyclic pigments, perylene and perinone pigments, thioindigo pigments, anthrapyrimidone pigments, flavanthrone pigments, anthanthrone pigments, dioxazine pigments, triarylcarbonium pigments, quinophthalone pigments, and diketopyrrolo pyrrole pigments.

[0108] Typically, the pigments and / or colorants, when particulates, have average particle diameters in the range of from 10 nm to 50 pm, preferably in the range of from 40 nm to 2 pm. The pigments and / or colorants when present are present in the range of from 2, alternatively from 3, alternatively from 5 to 20 wt. % of the composition.

[0109] Antioxidant

[0110] Any suitable antioxidant(s) may be utilised, if deemed required. Examples may include: ethylene bis (oxyethylene) bis(3-tert-butyl-4-hydroxy-5(methylhydrocinnamate) 36443-68-2; tetrakis[methylene(3,5- di-tert-butyl-4-hydroxy hydrocinnamate)]methane 6683-19-8; octadecyl 3,5-di-tert-butyl-4- hydroxyhyrocinnamate 2082-79-3; N,N’ -hexamethylene-bis (3,5-di-tert-butyl-4- hydroxyhyrocinnamamide) 23128-74-7; 3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid,C7-9 branched alkyl esters 125643-61-0; N-phenylbenzene amine, reaction products with 2,4,4-trimethylpentene 68411- 46-1; e.g., anti-oxidants sold under the Irganox™ name from BASF.

[0111] UV and / or light stabilizers

[0112] UV and / or light stabilizers may include, for the sake of example include benzotriazole, ultraviolet light absorbers and / or hindered amine light stabilizers (HALS) such as the TINUVIN® product line from Ciba Specialty Chemicals Inc.

[0113] Biocides

[0114] Biocides may additionally be utilized in the one-part condensation curable silicone composition if required. It is intended that the term “biocides” includes bactericides, fungicides and algicides, and the like. Suitable examples of useful biocides, which may be utilized in compositions as described herein, include, for the sake of example:

[0115] Carbamates such as methyl-N-benzimidazol-2-ylcarbamate (carbendazim) and other suitable carbamates, 10, 10’ -oxybisphenoxarsine, 2-(4-thiazolyl)-benzimidazole,

[0116] N-(fluorodichloromethylthio)phthalimide, diiodo methyl p-tolyl sulfone, if appropriate in combination with a UV stabilizer, such as 2,6-di(tert-butyl)-p-cresol, 3-iodo-2-propinyl butylcarbamate (IPBC), zinc 2-pyridinethiol 1-oxide, triazolyl compounds and isothiazolinones, such as 4,5-dichloro-2-(n-octyl)-4- isothiazolin-3-one (DCOIT), 2-(n-octyl)-4-isothiazolin-3-one (OIT) and n-butyl-l,2-benzisothiazolin-3- one (BBIT). Other biocides might include for example Zinc Pyridinethione, 1 -(4-Chlorophenyl)-4,4- dimethyl-3-(l,2,4-triazol-l-ylmethyl)pentan-3-ol and / or l-[[2-(2,4-dichlorophenyl)-4-propyl-l,3- dioxolan-2-yl] methyl]- 1 H- 1 ,2,4-triazole.

[0117] The fungicide and / or biocide may suitably be present in an amount of from greater than 0 to 0.3wt. % of the composition and may be present in an encapsulated form where required such as described in EP2106418. As mentioned above there is also provided a method of accelerating cure of a one-part condensation curable silicone composition comprising introducing component (d) one or more co-catalyst / reaction accelerator(s) as described above into a one-part condensation curable silicone composition otherwise comprising components (a) to (c) and optionally (e) and curing the composition. The cure process is usually undertaken at room temperature (i.e. from about 21 to 25°C). The speed of cure can be assessed by measuring the skin over time (SOT) and / or tack free time (TFT) using the methods described in the Examples below. It was found that either one or preferably both SOT and TFT showed significantly faster times than the composition without the one or more co-catalyst / reaction acceler tor(s) as described above (component (d)) present or comparatives to component (d) present. It was surprisingly found that the one or more co-catalyst / reaction accelerator / s) as described above (d) caused accelerated cure. Preferably once the components (a) to (d) and (e) when present as well as any other additives or the like have been mixed together, unless the resulting composition is to be utilised immediately the composition is sealed in one or more moisture-tight containers and is stored at a temperature in a range of between 0°C and 25°C inclusive therein.

[0118] In one embodiment, when present, one or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof (e) is first mixed into the polymer (a), optionally, if required in combination with a hydrophobic treating agent so that the filler(s) is / are treated in situ during the mixing into the polymer. Once the one or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof (e) is / are adequately mixed into the polymer (a) (and if desired has been hydrophobically treated) then the remaining components are added to make the complete composition.

[0119] There is also provided a cured silicone product which is the cured product of the above composition or is the product resulting from the method described above.

[0120] There is also provided a use of component (d) a co-catalyst / reaction accelerator as described above to accelerate the cure of a one-part condensation curable silicone composition otherwise comprising components (a) to (c) as described above and optionally the one or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof (e) and any other additives.

[0121] As indicated above, it was found that either one or preferably both SOT and TFT showed significantly faster times than the composition without the one or more co-catalyst / reaction accelerator(s) as described above (component (d)) present or comparatives to component (d) present. It was surprisingly found that the one or more co-catalyst / reaction accelerator / s) as described above (d) caused accelerated cure. In one embodiment the one-part condensation curable silicone composition herein may be designed to provide a low modulus sealant composition. For the purpose of this, “low modulus” sealants are defined according to ISO1 1600, second edition 2002-10-01 , section 4.3 Low modulus silicone sealant compositions are preferably “gunnable” i.e., they have a suitable extrusion capability i.e., a minimum extrusion rate of 10 ml / min as measured by ASTM Cl 183-04, alternatively 10 to 1000 mL / min, and alternatively 30 to 500 mL / min. The one-part condensation curable silicone composition may in such a case impart a movement capability to the post-cured sealant material. The movement capability is greater than 25 %, alternatively movement capability ranges from 25 % to 50 %, as measured by ASTM C719 - 13.

[0122] A one-part condensation curable silicone composition as hereinbefore described may be applied on to any suitable substrate. Suitable substrates may include, but are not limited to, glass; concrete; brick; stucco; metals, such as aluminium, copper, gold, nickel, silicon, silver, stainless steel alloys, and titanium; ceramic materials; plastics including engineered plastics such as epoxies, polycarbonates, poly(butylene terephthalate) resins, polyamide resins, polyvinyl chloride (PVC) and blends thereof, such as blends of polyamide resins with syndiotactic polystyrene commercially available from The Dow Chemical Company, of Midland, Michigan, U.S.A., acrylonitrile-butadiene-styrenes, styrene-modified poly(phenylene oxides), poly(phenylene sulfides), vinyl esters, polyphthalamides, and polyimides; cellulosic substrates such as paper, fabric, and wood; and combinations thereof.

[0123] However, preferably there is provided a use of the aforementioned one-part condensation curable silicone composition as a sealant in construction applications such as in silicone structural glazing, insulated glazing, Do-it-yourself (DIY) applications, industrial assembly and maintenance, fenestration applications (windows and door manufacture) and weather proofing applications.

[0124] In the case of the one-part condensation curable silicone composition as hereinbefore described, there is provided a method for filling a space between two substrates so as to create a seal therebetween, comprising: a) providing a one-part condensation curable silicone composition as hereinbefore described and either b) applying the one-part condensation curable silicone composition to a first substrate, and bringing a second substrate in contact with the silicone composition that has been applied to the first substrate, or c) filling a space formed by the arrangement of a first substrate and a second substrate with the one-part condensation curable silicone composition and d) curing same.

[0125] Examples

[0126] All viscosity measurements were taken at 25°C unless otherwise indicated. Unless otherwise indicated, all viscosities in the examples were measured using a Brookfield DV-II Viscometer in accordance with ASTM D2196 using Spindle 4 at 6 rpm.

[0127] A masterbatch (MB. 1) of Hydroxydimethyl terminated polydiorganosiloxane having a viscosity of 2000 mPa.s siloxane polymer and a treated ground calcium carbonate non-reinforcing filler was prepared with the composition depicted in Table 1 below. Table 1: Composition of Masterbatch 1 (MB. 1) used in examples (wt. %)

[0128] The ground calcium carbonate was hydrophobically treated and is sold commercially as GAMA- SPERCE™ CS-11 by Imerys S.A.

[0129] Nineteen comparative examples and three reference examples were prepared in addition to eight examples in accordance with this disclosure. All examples, comparatives and reference examples were formulated coatings / sealants were made in a FlakTek™ Speedmixer, commercially available from FlackTek Inc. The Masterbatch was added to the mixing container followed by the plasticizer and about 0.5 wt. % of methyltrimethoxysilane (MTM). The aminosilane under consideration was then added into the respective examples and comparative examples at the targeted loading depicted in one of Tables 2a to e. The aforementioned ingredients were then thoroughly mixed, after which and thoroughly mixed. After all these ingredients had been combined, the appropriate amount of Tyzor™ PITA-SM catalyst obtained from Dorf Ketal Speciality Catalysts LLC was added and mixed. The different compositions prepared are shown in Tables 2a to 2e below.

[0130] Table 2a: Composition of Ref. 1 and comparative examples C. 1 to C. 6 (wt. %)

[0131] In the above Table:

[0132] Titanium catalyst 1 was Tyzor™ PITA-SM, which is an 80 wt. % diisopropoxy bis(ethylacetoacetate) (TDIDE) and 20 wt. % methyl-trimethoxy silane commercially available from Dorf Ketal Speciality Catalysts LLC

[0133] Plasticizer was a trimethyl terminated polydimethylsiloxane having a viscosity of lOmPa.s at 25°C Aminosilane 1 was A-[3-(Trimethoxysilyl)propyl]ethylenediamine which has the structure (HsCO - Si - (CH2)3- N(H) - (CHajiNH, DMAPMS was A,A-Dimethyl-3-(trimethoxysilyl)propylamine which has the structure (CH3)2N(CH2)3Si(OCH3)3.

[0134] The TDIDE / Amine molar Ratio for C. 1 was calculated as follows:

[0135] TDIDE molar mass: 424 g / mol. Aminosilane 1 molar mass = 341.56 g / mol.

[0136] The moles for TDIDE and aminosilane 1 in C. 1 were:

[0137] (0.94g TDIDE*0.80) / 424g / mol = 1.774 x 10'3mols. (0.8 being the amount of TDIDE in the Tyzor™

[0138] PITA-SM,

[0139] 0.1 1 Aminosilane 1 / 222.36 = 4.947 x 10'4mols and consequently

[0140] 1.774 x 10'3 / 4.947 x 10^ = 3.59 so the TDIDE / Amine molar Ratio = 3.59 : 1

[0141] Table 2b: Composition of comparative examples C. 6 to C. 11 (wt. %)

[0142] MAPMS was N-methyl-3-(trimethoxysilyl)propylamine (alternatively N-methyl-3- (trimethoxysilyl)propan-l -amine, which has the structure (CH3)N(H) - (CH2)3Si(OCH3)3APMS was 3-(trimethoxysilyl)-l-propanamine which has the structure H2N - (CH2)3- Si(OCH3)3

[0143] Tabic 2c: Composition of Ref. 2 and comparative examples C. 12 to C. 16 (wt. %) HMHS was l,6-bis(trimethoxysilyl) hexane which has the structure

[0144] (H3CO)3 - Si - (CH2)6- Si (OCH3)3

[0145] BAPMS was [3-(Butylamino)propyl]trimethoxysilane which has the structure

[0146] (H3CO)3- Si - (CH2)3- N(H) -(CH2)3CH3

[0147] Table 2d: Composition of comparative examples C. 17 to C. 19, Ref. 3 as well as Ex. 1 and 2 (wt. %)

[0148] Amino silane 2 was bis(3-(trimethoxysilyl)propyl)amine which is in accordance with the disclosure herein and has the structure ((H3CO)3)3Si-(CH2)3-N(H) - (CH2)3- Si(OCH3)3

[0149] Table 2e: Composition of comparative examples Ex. 3 to Ex. 8 (wt. %)

[0150] Amino silane 3 was bis(3-trimethoxysilylpropyl)-N-methylamine which is in accordance with the disclosure herein and has the structure ((H3CO)3)3Si-(CH2)3-N(CH2) - (CH2)3- Si(OCH3)3. Each composition was assessed for its cure properties, by measuring the tack free time (TFT) All samples were tested at 22.2°C and relative humidity ranging between 27 - 33%. Measurements for tack-free time were conducted according to ASTM C679-15 using a plastic Polyethylene film. The results for the comparative compositions containing a variety of aminosilanes which are not in accordance with this disclosure are given together with three reference samples which did not contain any aminosilane are provided in Table 3a. The results in respect of the same three reference results together with the results for the working examples are provided in Table 3b below.

[0151] Table 3a: Comparative compositions containing a primary amine i.e., 3-(trimethoxysilyl)-l-propanamine. C. 9 to

[0152] 11 (APMS) e. a secondary amine, N-methyl-3-(trimethoxysilyl)propylamine (MAMPS, C. 6 to 8), and a tertiary amine A,A-Dimethyl-3-(trimethoxysilyl)propylamine (DMAMPS, C. 3 to 5) each containing an analogous propyl link between the nitrogen and the silicon atom were evaluated.

[0153] It was found that the results using both the primary and secondary amines have similar effects of increasing the tack-free time (slowing cure) as their concentration increases. The tertiary amine gave similar results to the reference results in respect to tack free time (TFT) but did provide a slight improvement in cure speed (faster tack-free time) as the concentration is increased.

[0154] We further studied the secondary amine results containing additional four carbon atoms (butyl, BAPMS, CE15-19) on the nitrogen atom compared to the effects of to evaluate how the additional spacing of the Bis-amine impacts the cure. It was found that the concentration of the secondary amine (BAPMS) increases cure until a minimum is achieved followed by decrease in cure speed as the concentration is increased.

[0155] A series of Examples (1 to 8) were then tested for their TFT. The results are provided in Table 3b and are compared below to the reference values obtained.

[0156] Table 3b: TFT results of the examples in comparison to the reference materials.

[0157] The molecular breakdown of the inventive examples was studied using a series of trimethoxy silanes containing portions of the Bis-amine to understand how it impacts the sealant / coating tack-free time. These inventive examples show the molecular architecture of aminosilanc 2 (the Bis-amine (Ex. 1 to 4) induces a significant increase in cure speed (faster tack- free time). Furthermore, aminosilane 3 the (3° amine, Ex. 5-8) have similar impact to the cure speed of the sealant, albeit not as strong as the aminosilane 2 Thus far the results suggest that both aminosilanes 2 and 3 both act as a co-catalyst inducing a faster cure speed. This result is highly surprising and non-obvious given the negative effect normally seen when introducing amines into such compositions foe adhesion promotion usually causing a decrease in TFT.

Claims

1. WHAT IS CLAIMED IS:

1. A one-part condensation curable silicone composition comprising:(a) an organopolysiloxane polymer having an average of at least two -OH groups or hydrolysable groups per molecule; and a viscosity of from 750 to 150,000mPa.s at 25°C,(b) one or more condensation catalysts selected from one or more alkyltitanates, one or more alkylzirconates or a mixture thereof;(c) one or more organosilane cross-linkers having at least two alkoxy groups, alternatively at least three alkoxy groups, per molecule;(d) a co-catalyst / reaction accelerator of the following structure(R10)3Si-X2-N(R9) - X2- Si(R10)3; where each R10is independently a methoxy or ethoxy group, each R9is hydrogen or an alkyl group having from 1 to 4 carbons and each X2is independently a linear alkyl group having from 1 to 6 carbons; and optionally(e) one or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof.

2. A one-part condensation curable silicone composition in accordance with claim 1 wherein the organopolysiloxane polymer having an average of at least two -OH groups or at least two hydrolysable groups per molecule or a mixture thereof (a), has the formula:X3.nRnSi-Z- (R ySiOn- i^iz-SiR'i -Z-Si-RnX3.n(1) in which each X is independently an OH or an alkoxy group, each R is an alkyl, alkenyl or aryl group, each R1is an OH group an alkoxy group, an alkyl group, an alkenyl group or an aryl group and Z is oxygen or a divalent organic group, typically containing from 2 to 10 carbons; each n is independently 0, 1, 2 or 3, y is 0, 1 or 2, preferably 2 and z is an integer consistent with said organopolysiloxane polymer having a viscosity of from 750 to 150,000mPa.s at 25°C.

3. A one-part condensation curable silicone composition in accordance with any preceding claim wherein component (d) is selected from one or more of bis (3-trimethoxysilylpropyf)amine, bis (3-triethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-N-methylamine, bis(3-triethoxysilylpropyl)-N-methylamine, bis(3-trimethoxysilylpropyl)-N-ethylamine or bis(3-triethoxysilylpropyl)-N-ethylamine.

4. A one -part condensation curable silicone composition in accordance with any preceding claim wherein component (d) is selected from one or more of bis (3-trimethoxysilylpropyl)amine or bis(3- trimethoxysilylpropyl)-N-methylamine.

5. A one -part condensation curable silicone composition in accordance with any preceding claim wherein the alkyltitanate catalysts and alkylzirconate catalysts comprise compounds according to the general formula:M[OR7]4Where M is titanium or zirconium and each R7may be the same or different and represents a monovalent, primary, secondary or tertiary aliphatic hydrocarbon group which may be linear or branched containing from 1 to 10 carbon atoms or is a partially chelated version of M[OR7]4.

6. A one -part condensation curable silicone composition in accordance with any preceding claim wherein component (b) is present herein being present in the composition in an amount of from 0.01 to 1 .5 wt. % of the composition.

7. A one -part condensation curable silicone composition in accordance with any preceding claim which additionally comprises component (e), one or more additives selected from rheological modifiers, water / moisture scavengers, plasticizers and / or extenders, pigments & colorants, s, antioxidants, UV and / or light stabilizers and biocides or a mixture thereof.

8. A method of accelerating cure of a one-part condensation curable silicone composition comprising one or more co-catalyst / reaction accelerators (d) of the following structure (R10)3Si-X2-N(R9) - X2- Si(R10)3; where each R10is independently a methoxy or ethoxy group, each R9is hydrogen or an alkyl group having from 1 to 4 carbons and each X2is independently a linear alkyl group having from 1 to 6 carbons; into a one-part condensation curable silicone composition otherwise comprising(a) an organopolysiloxane polymer having an average of at least two -OH groups or hydrolysable groups per molecule; and a viscosity of from 750 to 150,000mPa.s at 25°C,(b) one or more condensation catalysts selected from one or more alkyltitanates, one or more alkylzirconates or a mixture thereof;(c) one or more organosilane cross-linkers having at least two alkoxy groups, alternatively at least three alkoxy groups, per molecule; and optionally(e) one or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof.

9. A method of accelerating cure of a one-part condensation curable silicone composition in accordance with claim 8 wherein component (d) is selected from one or more of bis (3-trimethoxysilylpropyl)amine, bis (3-triethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-N-methylamine, bis(3-triethoxysilylpropyl)-N-methylamine, bis(3-trimethoxysilylpropyl)-N-ethyl mine or bis(3-triethoxysilylpropyl)-N-ethyl mine.

10. A method of accelerating cure of a one-part condensation curable silicone composition in accordance with claim 8 or 9 wherein the alkyltitanate catalysts and alkylzirconate catalysts may comprise compounds according to the general formula:M[OR7]4Where M is titanium or zirconium and each R7may be the same or different and represents a monovalent, primary, secondary or tertiary aliphatic hydrocarbon group which may be linear or branched containing from 1 to 10 carbon atoms or is a partially chelated version of MfOR7]4.

11. A method of accelerating cure of a one-part condensation curable silicone composition in accordance with claim 8, 9 or 10 wherein component (b) is present herein being present in the composition in an amount of from 0.01 to 1.5 wt. % of the composition.

12. A cured silicone product which is the cured product of the in accordance with any one of claims 1 to 7 or is the product resulting from the method in accordance with claims 8, 9, 10 or 11.

13. Use of a co-catalyst / reaction accelerator selected from one or more co-catalyst / reaction accelerators (d) of the following structure:(R10)3Si-X2-N(R9) - X2- Si(R10)3; where each R10is independently a methoxy or ethoxy group, each R9is hydrogen or an alkyl group having from 1 to 4 carbons and each X2is independently a linear alkyl group having from 1 to 6 carbons; to accelerate the cure of a one-part condensation curable silicone composition; wherein said one-part condensation curable silicone composition otherwise comprises:(a) an organopolysiloxane polymer having an average of at least two -OH groups or hydrolysable groups per molecule; and a viscosity of from 750 to 150,000mPa.s at 25°C,(b) one or more condensation catalysts selected from one or more alkyltitanates, one or more alkylzirconates or a mixture thereof;(c) one or more organosilane cross-linkers having at least two alkoxy groups, alternatively at least three alkoxy groups, per molecule; and optionally(e) one or more reinforcing fillers, one or more non-reinforcing fillers or a mixture thereof.

14. Use of one or more co-catalyst / reaction accelerators in accordance with claim 13 wherein component (d) is selected from one or more of one or more of bis (3-trimethoxysilylpropyl)amine, bis (3-triethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-N-methylamine, bis(3-triethoxysilylpropyl)-N-methylamine, bis(3-trimethoxysilylpropyl)-N-ethylamine or bis(3-triethoxysilylpropyl)-N-ethylamine.

15. Use of one or more co-catalyst / reaction accelerators in accordance with claim 13 or 14 wherein the alkyltitanate catalysts and alkylzirconate catalysts may comprise compounds according to the general formula:M[OR7]4Where M is titanium or zirconium and each R7may be the same or different and represents a monovalent, primary, secondary or tertiary aliphatic hydrocarbon group which may be linear or branched containingfrom 1 to 10 carbon atoms or is a partially chelated version of M[OR7]4 and / or is present in an amount of from 0.01 to 1.5 wt. % 0.05 to 0.5 wt.% of the composition.

16. Use of a one -part condensation curable silicone composition in accordance with any one of claims 1 to 7 as a sealant in in construction applications such as in silicone structural glazing, insulated glazing, Do-it-yourself (DIY) applications, industrial assembly and maintenance, fenestration applications (windows and door manufacture) and weather proofing applications.

17. A method for filling a space between two substrates to create a seal therebetween, comprising: a) providing a one-part condensation curable silicone composition in accordance with any one of claims 1 to 7 and either b) applying the one-part condensation curable silicone composition to a first substrate, and bringing a second substrate in contact with the silicone composition that has been applied to the first substrate, or c) filling a space formed by the arrangement of a first substrate and a second substrate with the one-part condensation curable silicone composition and d) curing same.

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