Silicone coating

Abstract

The present disclosure relates to a hydrosilylation curable silicone coating composition comprising a filler blend (b) of hydromagnesite and bellinite, a method of coating a textile material and / or an airbag with the hydrosilylation curable silicone coating composition, and a textile material and an airbag coated with a cured product of the hydrosilylation curable silicone coating composition.

Description

[0001] The present disclosure relates to a hydrosilylation-curable silicone coating composition, a method of coating a textile material and / or an airbag with the hydrosilylation-curable silicone coating composition, and a textile material and an airbag which are a cured product coated with the hydrosilylation-curable silicone coating composition.

[0002] Such hydrosilylation-curable silicone coating compositions can be used for screen printing, as a base coat for silicone leather, as an adhesive layer coating between textiles and silicone coatings, in particular for coating airbags and textile materials used in or for airbags.

[0003] An airbag arrangement in a vehicle generally consists of one or more inflatable textile bags (sometimes called cushions), sensors, and an inflation device.

[0004] The airbag and / or the textile material for manufacturing the airbag can be made of a woven or knitted fabric of synthetic fibers (e.g., polyamides such as nylon-6,6, or polyesters such as polyethylene terephthalate). The airbag can be made of flat textile material sheets, which are coated and then stitched together to provide sufficient mechanical strength (commonly referred to as a "cut-and-sewn, seam-sealed (CSSS) airbag"), or can be woven integrally with an integral woven seam (commonly referred to as an "one-piece woven (OPW) airbag"). The stitched flat textile material airbag is usually assembled with the coated textile material surface on the inner side of the airbag. The one-piece woven airbag is coated on the outside of the airbag and is capable of better maintaining air pressure after deployment, and thus tends to be used for airbags designed to remain inflated for a longer period of time after a collision or the like, for example, side curtain airbags.

[0005] A variety of airbags are used as inflatable safety restraint devices, designed to inflate and deploy in the event of a collision (most notably in a vehicle). Nowadays, it is usually necessary to have several airbags in a vehicle as a means of providing safety for the occupants in the event of a collision. They include front airbags, front center airbags, side airbags, side curtain airbags, chest airbags, and / or knee airbags.

[0006] Typically, the front airbag and / or the front center airbag and their inflating mechanisms are hidden within vehicle trim to be invisible during normal vehicle operation. For example, the front airbag can be installed in the center of the steering wheel boss on the driver's side of the vehicle and in the instrument panel on the passenger side of the vehicle, behind plastic flaps or doors that are designed to tear under the force of the bag inflation. They are provided to act as a cushion at the impact point, especially during a frontal or rear collision of the vehicle. Once a predetermined threshold is reached or exceeded, the airbag control unit triggers the ignition of the gas generator propellant to rapidly inflate the airbag. When the vehicle occupant collides with and compresses the bag, the gas is designed to escape from the bag in a controlled manner, and thus these airbags need to exhibit a relatively high breathability to allow the inflated airbag to deflate rapidly after the initial impact. Typically, these airbags are cut and sewn seam-sealed (CSSS) airbag designs, but they can also be one-piece woven designs if preferred or circumstances dictate.

[0007] Side curtain airbags are increasingly being used and are typically installed within the roof lining above the doors and windows and deployed along the side windows from near the roof to protect vehicle occupants from side impacts and the resulting rollover accidents (in a rollover accident, the vehicle rolls onto its side or upside down or rolls over more than once). However, side curtain airbags are mainly designed to protect passengers by maintaining their inflated state for a long duration during a rollover collision (e.g., exhibiting at least 50% retention of the initial pressure after 5 seconds from high-pressure inflation) and are typically deployed along the side windows of the vehicle from a packaging container stored within the roof line (and thus only have a rear side and a front side). Therefore, side curtain airbags are designed to not only provide a buffering effect but also provide protection against broken glass and other debris. Thus, as described above, side curtain airbags must remain inflated for several seconds until the end of the rollover period caused by the collision, i.e., they need to retain a large amount of gas and high air pressure for a relatively long period throughout the potential rollover.

[0008] Silicone rubber coatings are typically provided on textile materials and airbags and are designed to keep the airbag flexible and resistant to temperature fluctuations, aging, and wear. They require such properties because, for example, an airbag can remain unused for an extended period of time (e.g., several years) before deployment upon impact in a collision. This requires such silicone rubber coatings to be very stable over time to prevent the airbag from jamming and ensure smooth deployment even after many years. Such silicone rubber coatings need to provide good thermal stability because inflators are typically designed to release extremely hot gases during inflation, and these extremely hot gases can cause burns to the occupants, and the silicone rubber coatings are provided to prevent or at least significantly reduce the likelihood of the textile material coated therewith burning through and endangering the occupants. Additionally, while conventionally used silicone airbag coatings provide excellent durability, aging, and processability benefits, they also tend to exhibit very low tensile strength and elongation at break properties, which do not easily withstand high-pressure inflation without using very thick coatings.

[0009] It has been found that in the case of front and rear impact airbags, especially for CSSS airbags, with the development of devices for inflating such airbags, equipment such as gas generators has become increasingly mechanically and thermally erosive, causing additional problems regarding the stitching of such airbags in addition to the physical constraints associated with the deployment of the inflatable bag. This can lead to tearing of the silicone elastomer-coated textile material and opening of the stitches, resulting in tearing, combing (wear), and even bursting of certain airbags.

[0010] Accordingly, airbag manufacturers are seeking silicone elastomer coating compositions for applications with optimal mechanical properties, especially good tear strength and edge comb resistance (the ability of the coated textile material to withstand combing / wear of the stitches of the inflatable bag). However, the coatings produced by the curing of such compositions tend to have either good edge comb resistance or good tear strength. Achieving a good compromise between these two properties while maintaining good adhesion properties has proven to be a problem across the industry.

[0011] The silicone airbag coating compositions used are often hydrosilylation (addition) curable compositions that cure by crosslinking an organopolysiloxane polymer having at least two Si-vinyl groups with a crosslinker containing at least two, typically at least three, Si-H bonds per molecule. Such coating compositions are used to treat airbag fabrics, for example, on the inner side of CSSS type airbags and the outer side of OPW type airbags, and typically include silicone resins present (especially those called MQ resins) to achieve good fluidity and high modulus as well as flame retardancy, especially because they exhibit very good solubility in the vinyl organopolysiloxanes used. Generally, such compositions are considered to additionally require reinforcing fillers, such as precipitated silica and / or fumed silica, in order to enable the resulting coated airbags to achieve good edge combing resistance. However, if a large amount of reinforcing silica filler is used, the incorporation of such reinforcing fillers will cause significant thickening of the silicone airbag coating composition, resulting in high viscosity and shear thinning effects (non-Newtonian behavior of fluids with reduced viscosity under shear strain). This requires a low level of silica loading (e.g., less than or equal to 10 wt% of the composition) in order to maintain fluidity. Therefore, calcium carbonate (CaCO3) is commonly used as an additional filler because it does not have the same shear thinning effect, enabling the silicone airbag coating composition to maintain good fluidity at higher filler loading levels. However, alternative solutions are still being sought to achieve airbag coatings with all the different desired properties.

[0012] Provided herein is a hydrosilylation curable silicone coating composition comprising:

[0013] a) an organopolysiloxane polymer having a viscosity between 100 mPa·s and 200,000 mPa·s at 25 °C and having at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups;

[0014] b) a filler blend of hydromagnesite and huntite, the hydromagnesite having the structure Mg5(CO3)4(OH)2·4H2O and the huntite having the structure Mg3Ca(CO3)4, the filler blend being treatable with a suitable hydrophobic agent;

[0015] c) a silicone compound having at least two or three Si-

[0016] H groups per molecule;

[0017] d) a hydrosilylation curing catalyst;

[0018] e) one or more organosilicon resins containing an unsaturated group selected from an alkenyl group, an alkynyl group or a mixture of an alkenyl group and an alkynyl group, and the one or more organosilicon resins are selected from T organosilicon resins (sesquisiloxanes), DT organosilicon resins, MQ organosilicon resins, MDT organosilicon resins, MTQ organosilicon resins, QDT organosilicon resins or mixtures thereof;

[0019] f) an adhesion promoter selected from one or more monoacrylates, diacrylates or methacrylates; an epoxy group-containing alkoxysilane, a vinyl group-containing alkoxysilane, a methacrylic acid group-containing alkoxysilane or an acrylic acid group-containing alkoxysilane and mixtures and / or reaction products of the following substances:

[0020] i) one or more alkoxysilanes having an epoxy group in the molecule;

[0021] ii) a linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxyl group or alkoxy group per molecule; and iii) an organometallic condensation reaction catalyst including an organotitanium, organoaluminum or organozirconium compound; or mixtures thereof.

[0022] The present invention also provides a textile material or an airbag at least partially coated with an organosilicon coating, and the organosilicon coating is a cured elastomer product of the above-mentioned hydrosilylation-curable organosilicon coating composition.

[0023] There is also provided a method for coating a textile material or an airbag by the following steps: mixing the components of a hydrosilylation-curable organosilicon coating composition, and the composition includes:

[0024] A hydrosilylation-curable organosilicon coating composition, and the composition includes:

[0025] a) an organopolysiloxane polymer having a viscosity between 100 mPa·s and 200,000 mPa·s at 25°C and having at least two unsaturated groups per molecule, and the unsaturated groups are selected from an alkenyl group or an alkynyl group;

[0026] b) a filler blend of hydromagnesite and dolomite, the hydromagnesite having a structure of Mg5(CO3)4(OH)2·4H2O, the dolomite having a structure of Mg3Ca(CO3)4, and the filler blend can be treated with a suitable hydrophobic agent;

[0027] c) an organosilicon compound having at least two or three Si-

[0028] Group H;

[0029] d) A hydrosilylation curing catalyst;

[0030] e) One or more organosilicon resins containing an unsaturated group selected from an alkenyl group, an alkynyl group, or a mixture of an alkenyl group and an alkynyl group, and the one or more organosilicon resins are selected from T organosilicon resins (silsesquioxanes), DT organosilicon resins, MQ organosilicon resins, MDT organosilicon resins, MTQ organosilicon resins, QDT organosilicon resins, or mixtures thereof;

[0031] f) An adhesion promoter selected from one or more monoacrylates, diacrylates, or methacrylates; an epoxy group-containing alkoxysilane, a vinyl group-containing alkoxysilane, a methacrylic acid group-containing alkoxysilane, or an acrylic acid group-containing alkoxysilane, and a mixture and / or reaction product of the following substances:

[0032] i) One or more alkoxysilanes having an epoxy group in the molecule;

[0033] ii) A linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxyl group or alkoxy group per molecule; and iii) An organometallic condensation reaction catalyst including an organotitanium, organoaluminum, or organozirconium compound; or a mixture thereof; and

[0034] Coating the textile material or airbag with the composition and curing the composition.

[0035] There is also provided a coated textile material or a coated airbag, and the coated textile material or the coated airbag is obtained by or can be obtained by coating a textile material or an airbag through the following steps: mixing the components of a hydrosilylation-curable organosilicon coating composition, and the composition comprises:

[0036] A hydrosilylation-curable organosilicon coating composition, and the composition comprises:

[0037] a) An organopolysiloxane polymer having a viscosity between 100 mPa·s and 200,000 mPa·s at 25 °C and having at least two unsaturated groups per molecule, and the unsaturated groups are selected from an alkenyl group or an alkynyl group;

[0038] b) A filler blend of hydromagnesite and nesquehonite, wherein the hydromagnesite has the structure Mg5(CO3)4(OH)2·4H2O and the nesquehonite has the structure Mg3Ca(CO3)4, and the filler blend can be treated with a suitable hydrophobic agent;

[0039] c) A silicone compound having at least two or three Si-

[0040] H groups per molecule;

[0041] d) A hydrosilylation curing catalyst;

[0042] e) One or more silicone resins containing an unsaturated group selected from an alkenyl group, an alkynyl group, or a mixture of an alkenyl group and an alkynyl group, and the one or more silicone resins are selected from T silicone resins (sesquisiloxanes), DT silicone resins, MQ silicone resins, MDT silicone resins, MTQ silicone resins, QDT silicone resins, or mixtures thereof;

[0043] f) An adhesion promoter selected from one or more monoacrylates, diacrylates, or methacrylates; alkoxysilanes containing an epoxy group, alkoxysilanes containing a vinyl group, alkoxysilanes containing a methacrylic acid group, or alkoxysilanes containing an acrylic acid group, and mixtures and / or reaction products of the following substances:

[0044] i) One or more alkoxysilanes having an epoxy group in the molecule;

[0045] ii) Linear organopolysiloxane oligomers containing at least one alkenyl group and at least one hydroxyl group or alkoxy group per molecule; and iii) Organometallic condensation reaction catalysts including organotitanium, organoaluminum, or organozirconium compounds; or mixtures thereof; and coating the textile material or airbag with the composition and curing the composition.

[0046] It has been found that the combination of component (b) and component (e) surprisingly provides a coating composition having good fluidity without a shear-thinning effect, and post-curing provides improved edge combability resistance, retained adhesion, and mechanical strength, which is significant and surprising because such results are achieved in the absence of fumed silica and precipitated silica and preferably also in the absence of calcium carbonate.

[0047] Although the hydrosilylation-curable silicone coating compositions of the present disclosure can be used for screen printing, as a base coat for silicone leather, as an adhesive layer coating between textiles and silicone coatings, the present disclosure relates to textile materials for manufacturing cut-and-sewn seam-sealed (CSSS) airbags or one-piece woven airbag designs, and two types of airbags, particularly those for providing cushioning to an occupant after a frontal or rear collision, rather than side airbags that tend to require a relatively long inflation period. Such coating compositions are applied to the surface of a textile material that is designed to be on the inside of a CSSS-type airbag and for coating onto the outside of a one-piece woven airbag, each designed to cushion frontal and rear collisions. They are not designed to be used as coatings for curtain or side airbags that require an extended inflation period. The hydrosilylation-curable silicone coating compositions of the present disclosure are designed to be applied directly to the material / airbag and generally will not be used as a top coat on top of an intermediate coat applied directly to the fabric / airbag. Additionally, such coatings as described herein will not require a top coat applied thereto to function.

[0048] The hydrosilylation-curable silicone coating composition for manufacturing a coating comprises the following components:

[0049] (a) Organopolysiloxane polymer

[0050] Component (a) of the hydrosilylation-curable silicone coating composition is one or more organopolysiloxane polymers that have a viscosity between 100 mPa·s and 200,000 mPa·s at 25 °C and have at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups. Each organopolysiloxane polymer of component (a) comprises a plurality of silanoxy units of formula (I):

[0051] R’ a SiO (4-a) / 2 (I)

[0052] The subscript “a” is 0, 1, 2, or 3.

[0053] When R’ is generally an aliphatic hydrocarbon group, a substituted aliphatic hydrocarbon group, an aromatic group, or a substituted aromatic group and is further described below, alternatively an alkyl group, usually a methyl group, the silanoxy units can be described by shorthand (abbreviated) nomenclature, namely “M”, “D”, “T”, and “Q”. The M unit corresponds to the silanoxy unit where a = 3, i.e., R’3SiO 1 / 2 ; the D unit corresponds to the silanoxy unit where a = 2, i.e., R’2SiO 2 / 2; The T unit corresponds to a silanoxy unit, where a = 1, i.e., R’1SiO 3 / 2 ; The Q unit corresponds to a silanoxy unit, where a = 0, i.e., SiO 4 / 2 . The organopolysiloxane polymer of component (a) is substantially linear, but may contain a certain proportion of branches due to the presence of T units within the molecule (as previously described), and thus the average value of a in structure (I) is about 2.

[0054] The unsaturated groups of component (a) can be located at the ends or side chains of the organopolysiloxane polymer, or at both positions. The unsaturated groups of component (a) can be alkenyl or alkynyl groups as described above. When present, each alkenyl group can contain, for example, 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, alternatively 2 to 6 carbon atoms. When present, the alkenyl group can be exemplified by, but not limited to, vinyl, allyl, methallyl, propenyl, and hexenyl, as well as cyclohexenyl. When present, each alkynyl group can also have 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, alternatively 2 to 6 carbon atoms. Examples of alkynyl groups can be exemplified by, but not limited to, ethynyl, propynyl, and butynyl groups. Preferred examples of the unsaturated groups of component (a) include vinyl, propenyl, isopropenyl, butenyl, allyl, and 5-hexenyl.

[0055] In formula (I), in addition to the above-mentioned unsaturated groups, each R’ is independently selected from aliphatic hydrocarbon groups, substituted aliphatic hydrocarbon groups, aromatic groups, or substituted aromatic groups. Each aliphatic hydrocarbon group can be exemplified by, but not limited to, alkyl or cycloalkyl groups having 1 to 20 carbon atoms / group, alternatively 1 to 15 carbon atoms / group, alternatively 1 to 12 carbon atoms / group, alternatively 1 to 10 carbon atoms / group, alternatively 1 to 6 carbon atoms / group, such as cyclohexyl. Specific examples of alkyl groups can include methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl groups, alternatively methyl and ethyl groups. The substituted aliphatic hydrocarbon group is preferably a non-halogenated substituted alkyl group.

[0056] Aliphatic non-halogenated organic groups are exemplified by, but not limited to, the above-mentioned alkyl groups having substituted groups, such as suitable nitrogen-containing groups, such as acylamino and imino; oxygen-containing groups (such as polyoxyalkylene groups, carbonyl groups, alkoxy groups, and hydroxyl groups). Additional organic groups can include sulfur-containing groups, phosphorus-containing groups, and boron-containing groups. Examples of aromatic groups or substituted aromatic groups are phenyl groups and substituted phenyl groups having substituted groups as described above.

[0057] Component (a) can be selected, for example, from polydimethylsiloxane, alkylmethylpolysiloxane, alkylarylpolysiloxane, or copolymers thereof (wherein the alkyl mentioned refers to any suitable alkyl, alternatively an alkyl having two or more carbons), provided that each polymer has a viscosity of the organopolysiloxane polymer (a) that should be between 100 mPa·s and 200,000 mPa·s at 25 °C.

[0058] Thus, for example, component (a) can be:

[0059] Dialkylvinyl-terminated polydimethylsiloxane, such as dimethylethylvinyl-terminated polydimethylsiloxane; dialkylvinyl-terminated dimethylmethylphenylsiloxane, such as dimethylethylvinyl-terminated dimethylmethylphenylsiloxane; trialkyl-terminated dimethylmethylvinyldisiloxane; dialkylvinyl-terminated dimethylmethylvinyldisiloxane copolymer; dialkylvinyl-terminated methylphenylpolysiloxane, dialkylvinyl-terminated methylvinylmethylphenylsiloxane; dialkylvinyl-terminated methylvinyldiphenylsiloxane; dialkylvinyl-terminated methylvinylmethylphenyldimethylsiloxane; trimethyl-terminated methylvinylmethylphenylsiloxane; trimethyl-terminated methylvinyldiphenylsiloxane; or trimethyl-terminated methylvinylmethylphenyldimethylsiloxane.

[0060] In each case, the viscosity of the organopolysiloxane polymer (a) of component (a) should be between 100 mPa·s and 200,000 mPa·s at 25 °C, alternatively between 1000 mPa·s and 150,000 mPa·s at 25 °C, alternatively 1000 mPa·s to 125,000 mPa·s, alternatively between 1000 mPa·s and 100,000 mPa·s at 25 °C. Unless otherwise specified, all viscosity measurements given are made according to ASTM D1084 Method B using a Brookfield DVIII rotational viscometer with a rotor CP-52 most suitable for measuring viscosity at 1 rpm. Generally, for each organopolysiloxane polymer containing at least two silicon-bonded alkenyl groups per molecule of component (a), the alkenyl and / or alkynyl content (such as vinyl content) of the polymer is 0.01 wt% to 3 wt%, alternatively for this organopolysiloxane containing at least two unsaturated groups per molecule or for component (a) of each organopolysiloxane is 0.01 wt% to 2.5 wt%, alternatively component (a) is 0.001 wt% to 2.0 wt%, 0.01 wt% to 1.5 wt%, and the unsaturated group is selected from the alkenyl or alkynyl group per molecule of component (a). The alkenyl / alkynyl content of component (a) is determined by quantitative infrared analysis according to ASTM E168.

[0061] Component (a) can be present in the composition in an amount of 40% to about 80% by weight of the composition, alternatively 45% to 80% by weight of the composition, alternatively 50% to 80% by weight of the composition. Generally, component (a) is present in an amount that is the difference between 100% by weight of the composition and the cumulative weight percentage of the other components / constituents.

[0062] Component (b) Filler blend of hydromagnesite and huntite (HMH)

[0063] Component (b) of the hydrosilylation-curable organosilicon coating composition is a filler blend of hydromagnesite and huntite, where hydromagnesite has the structure Mg5(CO3)4(OH)2·4H2O and huntite has the structure Mg3Ca(CO3)4, and this filler blend can be treated with a suitable hydrophobic agent.

[0064] Hydromagnesite is a hydrated magnesium carbonate mineral, sometimes called light magnesium carbonate.

[0065] Generally, both hydromagnesite and huntite are naturally hydrophilic, and thus can be treated with a hydrophobic treatment agent to make them hydrophobic. These surface-modified filler blends (b) do not cake and can be uniformly incorporated into the organopolysiloxane polymer (a) because the surface treatment makes the fillers readily wetted by the organopolysiloxane polymer (a). The blend of hydromagnesite and huntite can be obtained commercially, for example, under the trade names UltraCarb TM 1251, UltraCarb TM 1253 and UltraCarb TM LH3C from LKAB Minerals AB in Lulea, Sweden. Such filler blends contain particles having a particle size between 0.5 μm and 15 μm as measured by Malvern laser diffraction (data sheet). It should be understood that generally the huntite particles have a particle size of about 1.0 μm or less, which is much smaller than the particle size of the hydromagnesite particles.

[0066] Generally, both the hydrotalcite particles and the nesquehonite particles (b) can be surface-treated with any low molecular weight silicone compound disclosed in the art that is suitable for preventing wrinkling of the silicone composition during processing. For example, silanes, polydiorganosiloxanes, or silazanes (e.g., hexamethyldisilazane), short-chain siloxane diols, or fatty acids such as stearic acid or fatty acid esters such as stearates can be used to impart hydrophobicity to the filler, making it easier to handle and obtain a homogeneous mixture with other components. Specific examples of silicone compounds include, but are not limited to, silanol-terminated trifluoropropylmethylsiloxane, silanol-terminated vinylmethylsiloxane, tetramethyldi(trifluoropropyl)disilazane, tetramethyldivinyldisilazane, silanol-terminated MePh siloxane, liquid hydroxy-terminated polydiorganosiloxane containing an average of 2 to 20 diorganosiloxane repeating units per molecule, hexaorganodisiloxane, hexaorganodisilazane. In one embodiment herein, the hydrotalcite particles and the nesquehonite particles are treated with a fatty acid (e.g., stearic acid) or a fatty acid ester (such as a stearate) to render the filler hydrophobic. A small amount of water and a treating agent as a processing aid can be added.

[0067] The hydrotalcite and nesquehonite filler blend (b) can be pretreated before introducing the hydrosilylation-curable silicone coating composition or can be treated in situ (i.e., in the presence of at least a certain proportion of component (a) of the hydrosilylation-curable silicone coating composition herein, by mixing the fillers together into component (a) at room temperature or higher temperature until the fillers are completely treated). When the filler blend is treated with a fatty acid or a fatty acid ester, alternatively with stearic acid or one or more stearates, the filler blend is pretreated and introduced into the composition in a treated and thus hydrophobic form. Additionally, the untreated filler blend (b) is treated in situ with a treating agent in the presence of the organopolysiloxane polymer (a), which results in the preparation of a silicone rubber matrix material that can subsequently be mixed with other components.

[0068] In a preferred embodiment, the filler blend (b) does not contain silica. In a preferred embodiment, the filler blend (b) does not contain calcium carbonate. In a preferred embodiment, the filler blend (b) does not contain silica and calcium carbonate.

[0069] The filler blend (b) is present in the composition in an amount of 5.0 wt% to 40 wt% of the composition, alternatively 7.5 wt% to 35 wt% of the composition, alternatively 7.5 wt% to 30 wt% of the composition.

[0070] Component (c) Crosslinking agent

[0071] Component (c) is used as a crosslinking agent and is provided in the form of a silicone compound having at least two, alternatively at least three Si-H groups per molecule. Component (c) typically contains three or more silicon-bonded hydrogen atoms, so that the hydrogen atoms can react with the unsaturated groups (alkenyl and / or alkynyl) of component (a) and / or the remainder of the composition to form a network structure therewith, and thereby cure the composition. Alternatively, some or all of component (c) can have two silicon-bonded hydrogen atoms per molecule.

[0072] However, when, for example, polymer (a) has more than two unsaturated groups per molecule, such a molecule serves only as the sole crosslinking agent, in which case a network can be generated during the curing process. Additionally, when component (c) partially contains molecules having two silicon-bonded hydrogen atoms per molecule, such molecules can serve as chain extenders.

[0073] The molecular configuration of the silicone compound (c) having at least two or at least three Si-H groups per molecule is not particularly limited, and it can be a silane, or a linear, branched (linear with some branches due to the presence of T groups) or cyclic polymer, or based on a silicone resin.

[0074] Although the molecular weight of component (c) is not particularly limited, the viscosity can be measured using the method discussed above.

[0075] The silicon-bonded organic groups used in component (c) can be exemplified by: alkyl groups such as methyl, ethyl, propyl, n-butyl, tert-butyl, pentyl, hexyl; aryl groups such as phenyl, tolyl, xylyl or similar aryl groups; 3-chloropropyl, 3,3,3-trifluoropropyl or similar haloalkyl groups, preferably alkyl groups having 1 to 6 carbons, especially methyl, ethyl or propyl groups or phenyl groups. Preferably, the silicon-bonded organic groups used in component (c) are alkyl groups, alternatively methyl, ethyl or propyl.

[0076] Examples of the silicone compound (c) having at least two, alternatively at least three Si-H groups per molecule include, but are not limited to:

[0077] (a) Methylhydrogenpolysiloxane endblocked with trimethylsilyloxy,

[0078] (b) Polydimethylsiloxane-methylhydrogensiloxane endblocked with trimethylsilyloxy,

[0079] (c) Dimethylhydrogensiloxane endblocked dimethylsiloxane-methylhydrogensiloxane copolymer,

[0080] (d) Dimethylsiloxane-methylhydrogensiloxane cyclic copolymer,

[0081] (e) A copolymer and / or silicone resin composed of (CH3)2HSiO 1 / 2 units, (CH3)3SiO 1 / 2 units and SiO 4 / 2 units,

[0082] (f) A copolymer and / or silicone resin composed of (CH3)2HSiO 1 / 2 units and SiO 4 / 2 units,

[0083] (g) A cyclic homopolymer of methylhydrogensiloxane having 3 to 10 silicon atoms per molecule.

[0084] In one embodiment, component (c) is selected from methylhydrogenpolysiloxane capped with trimethylsilyloxy groups at both molecular ends; a copolymer of methylhydrogensiloxane and dimethylsiloxane capped with trimethylsilyloxy groups at both molecular ends; dimethylsiloxane capped with dimethylhydrogensiloxy groups at both molecular ends; a copolymer of methylhydrogensiloxane and dimethylsiloxane capped with dimethylhydrogensiloxy groups at both molecular ends.

[0085] The crosslinking agent of component (c) is usually present in the organosilicon coating composition curable by hydrosilylation, such that the molar ratio of the silicon-bonded hydrogen atoms in component (c) to the total unsaturated groups selected from alkenyl and / or alkynyl groups in the composition is 0.5:1 to 20:1. When this ratio is less than 0.5:1, a well-cured composition will not be obtained. When this ratio exceeds 20:1, there is a tendency for the cured composition to increase in hardness when heated.

[0086] Preferably, the crosslinking agent is present in an amount such that the molar ratio of the silicon-bonded hydrogen atoms of component (c) to the total unsaturated groups selected from alkenyl and / or alkynyl groups in the organopolysiloxane (a) is preferably at least 1:1, and can be up to 8:1 or 10:1. Most preferably, the molar ratio of the Si-H group to the aliphatic unsaturated group is in the range of 1.1:1 to 5:1.

[0087] The silicon-bonded hydrogen (Si-H) content of component (c) is determined using quantitative infrared analysis according to ASTM E168. In this case, when relying on the hydrosilylation curing process, the ratio of silicon-bonded hydrogen to alkenyl (vinyl) and / or alkynyl is important. Generally speaking, this is determined by calculating the total weight % of alkenyl (e.g., vinyl) [V] in the composition and the total weight % of silicon-bonded hydrogen [H] in the composition, and assuming the molecular weight of hydrogen is 1 and the molecular weight of vinyl is 27, then the molar ratio of silicon-bonded hydrogen to vinyl is 27[H] / [V].

[0088] Typically, depending on the number of unsaturated groups in component (a) and the remainder of the composition and the number of Si-H groups in component (c), component (c) will be present in an amount of from 0.1% to 20% by weight of the hydrosilylation-curable silicone coating composition, alternatively from 0.1% to 15% by weight of the hydrosilylation-curable silicone coating composition, alternatively from 0.25% to 10% by weight, further alternatively from 0.5% to 10% by weight of the hydrosilylation-curable silicone coating composition, alternatively from 0.5% to 10% by weight of the hydrosilylation-curable silicone coating composition.

[0089] (d) Hydrosilylation catalyst

[0090] Component (d) of the hydrosilylation-curable silicone coating composition is a hydrosilylation catalyst comprising or consisting of a platinum group metal or a compound thereof. These catalysts are typically selected from catalysts of platinum group metals (platinum, ruthenium, osmium, rhodium, iridium and palladium), or compounds of one or more of such metals. Alternatively, due to the high activity level of these catalysts in the hydrosilylation reaction, platinum and rhodium compounds are preferred, with platinum compounds being most preferred. In the hydrosilylation (or addition) reaction, a hydrosilylation catalyst such as component (d) herein catalyzes the reaction between an unsaturated group (usually an alkenyl group, e.g., vinyl) and an Si-H group.

[0091] The hydrosilylation catalyst of component (d) can be a platinum group metal, a platinum group metal deposited on a support (such as activated carbon, a metal oxide such as alumina or silica, silica gel or charcoal powder), or a compound or complex of a platinum group metal. Preferably the platinum group metal is platinum.

[0092] Examples of preferred hydrosilylation catalysts for component (d) are platinum-based catalysts such as platinum black, platinum oxide (Adams catalyst), platinum on various solid supports, chloroplatinic acid (e.g., hexachloroplatinic acid (Pt in oxidation state IV) (Speier catalyst)), chloroplatinic acid in a solution of an alcohol (e.g., isooctyl alcohol or amyl alcohol) (Lamoreaux catalyst), and complexes of chloroplatinic acid with ethylenically unsaturated compounds such as olefins and organosiloxanes containing ethylenically unsaturated silicon-bonded hydrocarbon groups, such as tetraethenyltetramethylcyclotetrasiloxane-platinum complex (Ashby catalyst). Soluble platinum compounds that can be used include, for example, platinum-olefin complexes of the formula (PtCl2.(olefin)2 and H(PtCl3.olefin), and in this context, olefins having 2 to 8 carbon atoms such as ethylene, propylene, isomers of butene, and isomers of octene, or cycloalkanes having 5 to 7 carbon atoms such as cyclopentene, cyclohexene, and cycloheptene are preferably used. Other soluble platinum catalysts are, for example, platinum-cyclopropane complexes of the formula (PtCl2C3H6)2, reaction products of hexachloroplatinic acid with alcohols, ethers, and aldehydes or mixtures thereof, or reaction products of hexachloroplatinic acid and / or its conversion products with vinyl-containing siloxanes such as methylvinylcyclotetrasiloxane in the presence of an ethanol solution containing sodium bicarbonate. Platinum catalysts having phosphorus, sulfur, and amine ligands can also be used, such as (Ph3P)2PtCl2; and complexes of platinum with vinylsiloxanes such as symmetric divinyltetramethyldisiloxane (Karstedt catalyst).

[0093] Thus, specific examples of suitable platinum-based catalysts for component (d) include

[0094] (i) Complexes of chloroplatinic acid with organosiloxanes containing ethylenically unsaturated hydrocarbon groups, as described in US 3,419,593;

[0095] (ii) Chloroplatinic acid in the form of the hexahydrate or the anhydrous form;

[0096] (iii) Platinum-containing catalysts obtained by a method comprising the step of reacting chloroplatinic acid with an aliphatic unsaturated organosilicon compound such as divinyltetramethyldisiloxane;

[0097] (iv) Olefin-platinum-silyl complexes as described in US Patent 6,605,734, such as (COD)Pt(SiMeCl2)2, where "COD" is 1,5-cyclooctadiene; and / or

[0098] (v) Karstedt catalyst, which typically contains about 1 wt% in a vinylsiloxane polymer

[0099] Platinum divinyltetramethyldisiloxane complex of platinum. Solvents such as toluene and similar organic solvents have been used historically as alternatives, but the use of vinylsiloxane polymers is the preferred choice so far. These are described in US3,715,334 and US3,814,730. In a preferred embodiment, component (d) can be selected from coordination compounds of platinum. In one embodiment, hexachloroplatinic acid and its conversion products with vinyl-containing siloxanes, Karstedt catalysts, and Speier catalysts are preferred.

[0100] Based on the weight of the composition, the catalytic amount of the hydrosilylation catalyst is generally between 0.01 ppm and 10,000 parts by weight per million parts (ppm) of platinum group metals; alternatively between 0.01 ppm and 5000 ppm; alternatively between 0.01 ppm and 3,000 ppm and alternatively between 0.01 ppm and 1,000 ppm. In a specific embodiment, based on the weight of the composition, the catalytic amount of the catalyst can be in the range of 0.01 ppm to 1,000 ppm, alternatively 0.01 ppm to 750 ppm, alternatively 0.01 ppm to 500 ppm, and alternatively 0.01 ppm to 100 ppm of metal. This range can refer only to the metal content within the catalyst or to the whole catalyst as detailed (including its ligands), but typically these ranges refer only to the metal content within the catalyst. The catalyst can be added as a single substance or as a mixture of two or more different substances. Generally, depending on the form / concentration of the catalyst provided (e.g., in a polymer or solvent), the amount of component (d) present will be in the range of 0.001 wt% to 3.0 wt% of the composition, alternatively 0.001 wt% to 1.5 wt% of the composition, alternatively 0.01 wt% to 1.5 wt% of the composition, and alternatively 0.01 wt% to 1.0 wt% of the organosilicon coating composition curable by hydrosilylation.

[0101] (e) Unsaturated group containing one or more of an alkenyl group, an alkynyl group, or a mixture of an alkenyl group and an alkynyl group One or more silicone resins

[0102] One or more organosilicon resins of component (e) in the organosilicon coating composition curable by hydrosilylation are organosilicon resins containing unsaturated groups selected from alkenyl groups, alkynyl groups, or a mixture of alkenyl groups and alkynyl groups, and are selected from T organosilicon resins (sesquisiloxanes), DT organosilicon resins, MQ organosilicon resins, MDT organosilicon resins, MTQ organosilicon resins, QDT organosilicon resins, or mixtures thereof.

[0103] Such resins of component (e) using the MDTQ notation contain Q-type (SiO 4 / 2 ) siloxane units, T-type (R 2 1SiO3 / 2 ) siloxane units, D-type (R 2 1SiO 3 / 2 ) siloxane units and (M) siloxane units. These resins can be classified into two main categories: silsesquioxanes and silicates. Silsesquioxanes or T resins are mainly composed of T units and can be synthesized by hydrolysis and condensation of alkoxysilanes, chlorosilanes, or mixtures thereof. Silicates or MQ resins are mainly composed of M units and Q units and can be synthesized by hydrolysis and condensation of alkoxysilanes and chlorosilanes. Alternatively, MQ resins can be synthesized by polymerization of aqueous alkali metal silicates in the presence of an acid, followed by reaction with triorganoalkoxysilanes, triorganochlorosilanes, hexaorganodisiloxanes, or mixtures thereof.

[0104] Preferably, component (e) is one or more MQ resins. Generally, the MQ resins of component (e) contain SiO 4 / 2 (Q) siloxane units and (M) siloxane units, where each R 2 can be the same or different and represents a monovalent group selected from hydrocarbon groups, having 1 to 20 carbon atoms and alternatively 1 to 12 carbon atoms. Examples of suitable R 2 groups include alkyl groups such as methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl groups; alicyclic groups such as cyclohexyl; alkenyl groups having 2 to 12 carbons such as vinyl, propenyl, butenyl, pentenyl, hexenyl, etc.; alkynyl groups selected from ethynyl, propynyl, butynyl, pentynyl, or hexynyl, etc.; aryl groups such as phenyl, tolyl, xylyl, benzyl, α-methylstyryl, and 2-phenylethyl; alternatively the R 2 group is a vinyl, methyl, ethyl, or phenyl group, for example preferably the Examples of (M) siloxane units include and where Me represents methyl hereinafter, Vi is vinyl, and Ph represents phenyl hereinafter. Alternatively, the T organosilicon resin can be called silsesquioxane. The organosilicon resin can be a single organosilicon resin or a mixture containing two or more different organosilicon resins (each as described above). Generally, they are MQ resins containing in combination with and / or groups.

[0105] Alternatively, the silicone resin may be an MQ resin that can contain residual OZ (where Z can represent hydrogen or an alkyl group). After synthesizing the silicone MQ resin, the OZ groups remain on the Q component, indicating incomplete condensation during the reaction to produce the MQ resin, provided that the OZ content meets the above hydroxyl / mole Si requirement. The residual OZ is inherent to the method and reaction for preparing the MQ resin. The MQ resin may also undergo subsequent methylsilylation reactions to further minimize the residual OZ.

[0106] The silicone resin (e) is typically delivered in a hydrocarbon or silicone solvent, solvent-free, and the silicone resin is typically solid, but herein it is preferred that the silicone resin (e) is delivered in a silicone solvent such as non-functionalized polydimethylsiloxane or polydimethylsiloxane containing two or more alkenyl groups per molecule (such as, for example, component (a) herein).

[0107] For example, any suitable MQ resin can be used as component (e). The molar ratio of M siloxane units to Q siloxane units has a value of 0.5:1 to 1.2:1, alternatively 0.6:1 to 1.1:1, alternatively 0.8:1 to 1.1:1, alternatively 0.9:1 to 1.1:1. In one embodiment, the MQ resin (e) includes a resin portion where the M units are bonded to SiO 4 / 2 siloxane units (i.e., Q units), and each unit in the Q units is bonded to at least one other SiO 4 / 2 siloxane unit. The molar ratio of M units to Q units is 0.3:1 to 1.2:1, alternatively 0.4:1 to 1.1:1, alternatively 0.5:1 to 1:1, alternatively 0.6:1 to 0.9:1. Such MQ resins suitable as component (e) can have a number average molecular weight (Mn) of 2000 g / mol to 50,000 g / mol, alternatively 3,000 g / mol to 30,000 g / mol. In one embodiment, the silicone resin can be described in terms of mole fractions as an MQ silicone resin having the following formula:

[0108] (R 4 3SiO 1 / 2 ) u (SiO 4 / 2 ) v

[0109] where R 4 is a C1 to C 10 hydrocarbyl group without aliphatic unsaturation, u is 0.3 to 0.6, alternatively 0.37 to 0.52, v is 0.4 to 0.7, alternatively 0.48 to 0.63, and the value of u + v is 1.0.

[0110] Methods for preparing silicone resins are well known in the art. For example, they can be prepared by treating resin copolymers produced by a silica hydrosol capping method with endblockers containing alkyl and / or alkenyl groups. The method preferably includes reacting a silica hydrosol with hydrolyzable triorganosilanes such as trimethylchlorosilane, siloxanes such as hexamethyldisiloxane, and combinations thereof under acidic conditions, and then recovering a copolymer having M(R3SiO 1 / 2 ) units and Q(SiO 4 / 2 ) units, including 0.07 moles of hydroxyl groups per mole of silicon (Si) to 0.2 moles of hydroxyl groups per mole of Si. The copolymer can be further reacted with endblockers including saturated organic groups to achieve less than 0.06 moles of hydroxyl groups per mole of Si. Suitable endblockers include silazanes, siloxanes, silanes, and combinations thereof.

[0111] Component (e) can be present in the composition in an amount of 1 wt% - 60 wt%, alternatively 1 wt% - 40 wt%, and is an MQ resin or a T-resin (silsesquioxane), most preferably an MQ resin.

[0112] Components (a), (c), and (e) always consist of a mixture of macromolecular substances having different degrees of polymerization and thus 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 silicone polymers and / or resins can be determined by gel permeation chromatography (GPC) using polystyrene calibration standards. The technique is standard and yields Mw, Mn, and the polydispersity index (PI). Degree of polymerization (DP) = Mn / Mu, where Mn is the number-average molecular weight from GPC measurements and Mu is the molecular weight of the monomer unit. PI = Mw / Mn. DP is related to the viscosity of the polymer via Mw, and the higher the DP, the higher the viscosity. Silicone resins typically have a weight-average molecular weight (M w ) of 2,000 daltons to 50,000 daltons, alternatively 3,000 daltons to 45,000 daltons, alternatively 3,000 daltons to 40,000 daltons, alternatively 4,000 daltons to 30,000 daltons, alternatively 5,000 daltons to 30,000 daltons, where the molecular weight is determined by gel permeation chromatography using a triple detector system (e.g., a light scattering detector, a refractive index detector, and / or a viscosity detector) and polystyrene standards. In one embodiment, component (e) can be introduced into the composition as a mixture with all or part of component (a).

[0113] (f) Adhesion promoter

[0114] The hydrosilylation-curable silicone coating composition for preparing a coating for an integrated woven airbag further comprises an adhesion promoter (f). The adhesion promoter (f) can be any suitable adhesion promoter that is harmless to the mechanical properties of the cured coating on the airbag. For example, one or more monoacrylates, diacrylates or methacrylates. Examples can include diacrylates such as diacrylate C 4-20 alkylene glycol esters such as hexanediol diacrylate, heptanediol diacrylate, octanediol diacrylate, nonanediol diacrylate and / or undecanediol diacrylate. Examples of monoacrylates include alkoxysilanes containing a methacrylic acid group or an acrylic acid group, such as methacryloxymethyl-trimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-methacryloxypropyl-methyl dimethoxysilane, 3-methacryloxypropyl-dimethyl methoxysilane, 3-methacryloxypropyl-triethoxysilane, 3-methacryloxypropyl-methyl diethoxysilane, 3-methacryloxyisobutyl-trimethoxysilane or similar methacryloxy-substituted alkoxysilanes; 3-acryloxypropyl-trimethoxysilane, 3-acryloxypropyl-methyl dimethoxysilane, 3-acryloxypropyl-dimethyl-methoxysilane, 3-acryloxypropyl-triethoxysilane, or similar acryloxy-substituted alkyl-containing alkoxysilanes.

[0115] Examples of epoxy group-containing alkoxysilanes that can be used as adhesion promoters can include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyl dimethoxysilane, 4-glycidoxybutyltrimethoxysilane, 5,6-epoxyhexyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane or 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

[0116] The adhesion promoter (f) alternatively can include a combination of one or more alkoxysilanes with an organometallic condensation reaction catalyst such as an organotitanium compound (titanate), an organoaluminum compound (aluminate) or an organozirconium compound (zirconate).

[0117] In such cases, the alkoxysilane may contain a methacrylic group or an acrylic group, such as methacryloxymethyl-trimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-methacryloxypropyl-methyl-dimethoxysilane, 3-methacryloxypropyl-dimethyl-methoxysilane, 3-methacryloxypropyl-triethoxysilane, 3-methacryloxypropyl-methyl-diethoxysilane, 3-methacryloxyisobutyl-trimethoxysilane, or similar methacryloxy-substituted alkoxysilanes; 3-acryloxypropyl-trimethoxysilane, 3-acryloxypropyl-methyl-dimethoxysilane, 3-acryloxypropyl-dimethyl-methoxysilane, 3-acryloxypropyl-triethoxysilane, or similar acryloxy-substituted alkyl-containing alkoxysilanes.

[0118] The organometallic condensation reaction catalysts that can be used herein and contain an organoaluminum, organozirconium, or organotitanium compound can be selected from organometallic catalysts containing zirconates, titanates, organoaluminum chelates, zirconium chelates, and / or titanium chelates.

[0119] The catalysts based on zirconates and titanates may contain a compound according to the general formula Zr[OR 5 4 or Ti[OR 5 4, where each R 5 may be the same or different and represents a monovalent primary aliphatic hydrocarbon group, secondary aliphatic hydrocarbon group, or tertiary aliphatic hydrocarbon group, which may be a straight-chain group or a branched-chain group containing 1 to 20 carbon atoms, alternatively 1 to 10 carbon atoms. Optionally, the zirconate / titanate may contain partially unsaturated groups. Preferred examples of R 5 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. Preferably, when each R 5 is the same, R 5 is isopropyl, a branched secondary alkyl group, or a tertiary alkyl group, especially tert-butyl. Specific zirconium-based examples include zirconium tetrapropionate and zirconium tetrabutyrate, tetraisopropyl zirconate, zirconium(IV) tetraacetylacetonate (sometimes called zirconium AcAc4), zirconium(IV) hexafluoroacetylacetonate, zirconium(IV) trifluoroacetylacetonate, zirconium tetra(ethyltrifluoroacetylacetonate), zirconium tetra(2,2,6,6-tetramethyl-heptane thiosulfate), zirconium(IV) dibutoxy bis(ethylpyruvate), zirconium tributoxy acetylacetonate, zirconium butoxy bis(ethylacetoacetate) acetylacetonate, zirconium butoxy acetylpyruvate bis(ethylacetoacetate), zirconium diisopropoxy bis(2,2,6,6-tetramethyl-heptane thiosulfate), or similar zirconium complexes having a β-diketone (including their alkyl-substituted or fluorine-substituted forms) as a ligand.

[0120] Specific titanium-based examples include titanium tetrapropionate and titanium tetrabutyrate, zirconium tetra-isopropoxide, titanium(IV) tetraacetylacetonate (sometimes called titanium AcAc4), titanium(IV) hexafluoroacetylacetonate, titanium(IV) trifluoroacetylacetonate, titanium tetra(ethyltrifluoroacetylacetonate), titanium tetra(2,2,6,6-tetramethyl-heptane thiosulfate), dibutoxy bis(ethylpyruvate)titanium(IV), tributoxy acetoacetate titanium, butoxy bis(ethylacetoacetate) acetylacetonate titanium, butoxy bis(ethylacetoacetate) pyruvate titanium, diisopropoxy bis(2,2,6,6-tetramethyl-heptane thiosulfate) titanium or similar titanium complexes having a β-diketone as a ligand (including their alkyl-substituted or fluorine-substituted forms).

[0121] Suitable aluminum-based condensation catalysts can include, but are not limited to, one or more of Al(OC3H7)3, Al(OC3H7)2(C3COCH2COC 12 H 25 ), Al(OC3H7)2(OCOCH3) and Al(OC3H7)2(OCOC 12 H 25 ).

[0122] The organometallic condensation reaction catalyst can be present in the composition in an amount of 0.1 wt% to 5 wt% of the composition, alternatively 0.1 wt% to 3 wt% of the composition, alternatively 0.1 wt% to 2 wt% of the composition. When the adhesion promoter (f) comprises the cumulative amounts of (f)(i), (ii) and (iii), the adhesion promoter can account for about 0.3 wt% to 6 wt% of the composition, alternatively 0.3 wt% to 4 wt% of the composition.

[0123] In an alternative embodiment, the adhesion promoter (f) can alternatively comprise an adhesion promoter comprising a mixture and / or reaction product of:

[0124] i) one or more alkoxysilanes having an epoxy group in the molecule;

[0125] ii) a linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxyl or alkoxy group per molecule; and

[0126] iii) the organometallic condensation reaction catalyst as described above.

[0127] In this case, (f)(i) one or more alkoxysilanes having an epoxy group in the molecule may be 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 4-glycidoxybutyltrimethoxysilane, 5,6-epoxyhexyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane or 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane; and

[0128] (f)(ii) a linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxyl group or alkoxy group per molecule may be, for example, a methylvinylpolysiloxane in which both molecular ends are dimethylhydroxysilyloxy units, or a copolymer of methylvinylsiloxane and dimethylsiloxane units in which both molecular ends are dimethylhydroxysilyloxy units; and

[0129] The oligomeric organopolysiloxane may be a mixture of organopolysiloxane molecules, some of which have silanol end groups at both molecular ends and some of which have only one silanol end group, such as dimethylhydroxysilyloxy end units, and the other end unit is, for example, a dimethylmethoxysilyloxy unit, a trimethylsilyloxy unit or a dimethylethenylsilyloxy unit. Preferably, more than 50% by weight of the oligomeric organopolysiloxane, more preferably 60%-100% includes molecules having silanol end groups at both molecular ends.

[0130] The oligomeric organopolysiloxane preferably contains at least 3% by weight, more preferably at least 5% by weight of vinyl groups, and may contain up to 25% or 30% by weight of vinyl groups. Most preferably, the oligomeric organopolysiloxane contains 5% to 20% by weight of vinyl groups. The oligomeric organopolysiloxane preferably has a molecular weight of 300 to 10,000. The oligomeric organopolysiloxane preferably has a viscosity of 0.1 mPa·s to 300 mPa·s, alternatively 0.1 mPa·s to 200 mPa·s, alternatively 1 mPa·s to 100 mPa·s measured at 25 °C using a Brookfield DVIII rotational viscometer with rotor CP-52 at 12 rpm. Component (f)(ii) can be present in the composition in an amount of 0.1% to 5% by weight of the composition, alternatively 0.1% to 3% by weight, alternatively 0.1% to 2% by weight of the composition.

[0131] (f)(iii) an organometallic condensation reaction catalyst as described above in the amounts provided above.

[0132] The adhesion promoter provides strong adhesion properties between the resulting coating and a fabric substrate (including woven fabrics).

[0133] Additional optional components

[0134] Depending on its intended end use, additional optional ingredients may be present in the liquid silicone rubber composition as described above. Examples of such optional ingredients include cure inhibitors, thermal conductive fillers, pot life extenders, flame retardants, lubricants, pigments and / or colorants, fungicides, wetting agents, heat stabilizers, compression set additives, plasticizers, and mixtures thereof.

[0135] Curing inhibitor

[0136] When the hydrosilylation-curable silicone coating composition as described above is cured via an addition / hydrosilylation reaction, inhibitors can be utilized to inhibit the curing of the composition. These inhibitors are used to prevent premature curing during storage and / or to obtain a longer working time or pot life for the hydrosilylation-cured composition by delaying or inhibiting the activity of the catalyst. Inhibitors of the hydrosilylation catalyst (d) (e.g., platinum metal-based catalysts) are well known in the art and can include hydrazine, triazoles, phosphines, thiols, organic nitrogen compounds, alkynols, silylated alkynols, maleic esters such as dibutyl maleate; fumaric esters, ethylenically or aromatically unsaturated amides, ethylenically unsaturated isocyanates, olefinic siloxanes such as tetramethyltetravinylcyclotetrasiloxane; unsaturated hydrocarbon monoesters and diesters, conjugated ene-ynes, hydroperoxides, nitriles, and diaziridines. Vinyl-substituted siloxanes as described in US 3,989,667 can be used, with cyclic methylvinylsiloxanes being preferred.

[0137] A class of known inhibitors of hydrosilylation catalysts, for example platinum catalyst (d), includes the acetylenic compounds disclosed in US 3,445,420. Alkynols such as 2-methyl-3-butyn-2-ol constitute a preferred class of inhibitors, which will inhibit the activity of platinum-containing catalysts at 25 °C. Compositions containing these inhibitors generally need to be heated at a temperature of 70 °C or above in order to cure at an achievable rate.

[0138] Examples of alkynols and their derivatives include 1-ethynyl-1-cyclohexanol (ETCH), 2-methyl-3-butyn-2-ol, 3-butyn-1-ol, 3-methylbutynol, 3-butyn-2-ol, propargyl alcohol, 2-phenyl-2-propyn-1-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclopentanol, 1-phenyl-2-propynol, 3-methyl-1-pentene-4-yn-3-ol, and mixtures thereof. In an alternative, the inhibitor is selected from one or more of 1-ethynyl-1-cyclohexanol (ETCH), tetramethyltetravinylcyclotetrasiloxane, 3-methylbutynol, and / or dibutyl maleate.

[0139] When present, an inhibitor concentration of metal as low as one mole of inhibitor / mole of catalyst (d) will, in some cases, confer satisfactory storage stability and cure rate. In other cases, an inhibitor concentration of up to 500 moles of inhibitor / mole of catalyst (d) of metal is required. The optimum concentration of a given inhibitor in a given hydrosilylation-curable organosilicon coating composition herein can be readily determined by routine experimentation. The above mixtures can also be used. Depending on the concentration and form in which the selected inhibitor is provided / commercially available, when present in the composition, the inhibitor is generally present in an amount of 0.0001 wt% to 10 wt%, alternatively 0.001 wt% to 5 wt%, alternatively 0.0125 wt% to 5 wt% of the composition.

[0140] Pot life extender

[0141] Pot life extenders such as triazoles can be used.

[0142] Flame retardant

[0143] Examples of flame retardants include aluminum trihydrate, chlorinated paraffin, hexabromocyclododecane, triphenyl phosphate, dimethyl methylphosphonate, tris(2,3-dibromopropyl) phosphate (tribromoneopentyl phosphate), and mixtures or derivatives thereof.

[0144] Lubricant

[0145] Examples of lubricants include tetrafluoroethylene, resin powder, graphite, fluorinated graphite, talc, boron nitride, fluorinated oil, silicone oil, molybdenum disulfide, and mixtures or derivatives thereof. When present in the composition, the flame retardant is generally present in an amount of 0.1 wt% to 5 wt% of the composition.

[0146] Pigments and colorants

[0147] Examples of pigments include titanium dioxide, chromium(III) oxide, bismuth vanadium oxide, iron oxide, and mixtures thereof.

[0148] Examples of colorants that can be used in the organosilicon coating composition curable by hydrosilylation include pigments, vat dyes, reactive dyes, acid dyes, chrome dyes, disperse dyes, cationic dyes, and mixtures thereof. The two - part moisture - curable organopolysiloxane composition as described herein can also contain one or more pigments and / or colorants, which can be added if desired. The pigments and / or colorants can be colored, white, black, metallic - effect, and luminescent, such as fluorescent and phosphorescent. Pigments are used as needed to color the composition. Any suitable pigment that provides compatibility with the composition herein can be utilized. In the two - part moisture - curable organopolysiloxane composition, pigments and / or colored (non - white) fillers such as carbon black can be used in the catalyst package to color the final sealant product.

[0149] Suitable white pigments and / or colorants include titanium dioxide, zinc oxide, lead oxide, zinc sulfide, lithopone, zirconium oxide, and antimony oxide.

[0150] 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 vermilion; bismuth pigments such as bismuth vanadate and bismuth molybdate vanadate; mixed metal oxide pigments such as cobalt titanate green; chromate and molybdate pigments such as chrome yellow, molybdate red, and molybdate orange; ultramarine pigments; cobalt oxide pigments; nickel antimony titanate; lead chromate; carbon black; lamp black; and metallic - effect pigments such as aluminum, copper, copper oxide, bronze, stainless steel, nickel, zinc, and brass.

[0151] Suitable organic non - white pigments and / or colorants include phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; monoarylide yellow, diarylide yellow, benzimidazolone yellow, heterocyclic yellow, DAN orange, quinacridone pigments such as quinacridone magenta and quinacridone violet; organic reds, including metallized azo reds and non - metallized azo reds and other azo pigments, monoazo pigments, diazo pigments, azo pigment lakes, β - naphthol pigments, naphthol AS pigments, benzimidazolone pigments, diazo - condensation pigments, isoindolinone and isoindoline pigments, polycyclic pigments, perylene and violanthrone pigments, thioindigo pigments, anthrapyrimidine pigments, flavanthrone pigments, anthraquinone pigments, dioxazine pigments, triarylmethonium pigments, quinophthalone pigments, and diketopyrrolopyrrole pigments.

[0152] Typically, pigments and / or colorants, when in particulate form, have 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 pigments and / or colorants are present in the catalyst package composition in the range of 2 wt%, alternatively 3 wt%, alternatively 5 wt% to 20 wt%, alternatively up to 15 wt% of the catalyst package composition, alternatively up to 10 wt% of the catalyst package composition.

[0153] In a preferred embodiment, when present, the pigments and dyes are used in the form of a pigment masterbatch consisting of their dispersion in component (a) in a ratio of 25:75 to 70:30.

[0154] Heat stabilizer

[0155] Examples of heat stabilizers can include metal compounds such as iron oxide red, iron oxide yellow, iron hydroxide, cerium oxide, cerium hydroxide, lanthanum oxide, copper phthalocyanine, aluminum hydroxide, pyrogenic titanium dioxide, iron naphthenate, cerium naphthenate, cerium dimethyl polysiloxanol, and acetylacetonates of metals selected from copper, zinc, aluminum, iron, cerium, zirconium, titanium, etc. Other examples of heat stabilizers can include suitable antioxidants or metal scavengers such as 3-salicylamido-1,2,4-triazole, 1,2-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine, 2-hydroxy-N-1H-1,2,4-triazol-3-ylbenzamide, and N’1,N’12-bis(2-hydroxybenzoyl)dodecanedioylhydrazide. When present in the composition, the amount of the heat stabilizer can be in the range of 0.01 wt% to 1.0 wt% of the total composition.

[0156] In a preferred embodiment, the composition does not contain silica. In a preferred embodiment, the composition does not contain calcium carbonate. In a preferred embodiment, the composition does not contain silica and calcium carbonate.

[0157] In one embodiment, the hydrosilylation-curable organosilicon coating composition comprises:

[0158] a) An organopolysiloxane polymer having a viscosity at 25 °C of from 100 mPa·s to 200,000 mPa·s, alternatively between 1000 mPa·s and 150,000 mPa·s at 25 °C, alternatively from 1000 mPa·s to 125,000 mPa·s, alternatively from 1000 mPa·s to 100,000 mPa·s at 25 °C (measured using a Brookfield DVIII rotational viscometer with rotor CP-52 most suitable for measuring viscosity at 1 rpm according to ASTM D 1084 method B), having at least two unsaturated groups per molecule selected from alkenyl and / or alkynyl groups, in an amount of from 40 wt% to about 80 wt% of the composition, alternatively from 45 wt% to 80 wt% of the composition, alternatively from 50 wt% to 80 wt% of the composition;

[0159] b) A filler blend of hydromagnesite and nesquehonite, which filler blend may be treated with a suitable hydrophobicizing agent, such as with a fatty acid or a fatty acid ester such as a stearate ester, usually treated to render them hydrophobic, and present in an amount of from 5.0 wt% to 40 wt% of the composition, alternatively from 7.5 wt% to 35 wt% of the composition, alternatively from 7.5 wt% to 30 wt% of the composition;

[0160] c) An organosilicon compound having at least two, alternatively at least three Si-H groups per molecule, preferably where the molar ratio of silicon-bonded hydrogen atoms in component (c) to the total unsaturated groups selected from alkenyl and / or alkynyl in the composition is from 0.5:1 to 20:1, alternatively the molar ratio of silicon-bonded hydrogen atoms in component (c) to the total unsaturated groups selected from alkenyl and / or alkynyl in the organopolysiloxane (a) is preferably at least 1:1 and can be up to 8:1 or 10:1. Most preferably, the molar ratio of Si-H groups to aliphatic unsaturated groups is in the range of 1.1:1 to 5:1; the organosilicon compound having at least two, alternatively at least three Si-H groups per molecule is present in an amount of from 0.1 wt% to 20 wt% of the hydrosilylation-curable organosilicon coating composition, alternatively from 0.1 wt% to 15 wt% of the hydrosilylation-curable organosilicon coating composition, alternatively from 0.25 wt% to 10 wt%, further alternatively from 0.5 wt% to 10 wt% of the hydrosilylation-curable organosilicon coating composition. Component (c) acts as a crosslinking agent.

[0161] d) A hydrosilylation curing catalyst, wherein, based on the weight of the composition, the catalytic amount of the hydrosilylation catalyst is between 0.01 parts by weight per million parts (ppm) and 10,000 ppm of platinum group metals; alternatively between 0.01 ppm and 5000 ppm; alternatively between 0.01 ppm and 3,000 ppm and alternatively between 0.01 ppm and 1,000 ppm; metals in an amount of 0.01 ppm to 750 ppm, alternatively 0.01 ppm to 500 ppm, alternatively 0.01 ppm to 100 ppm, based on the weight of the composition, and wherein depending on the form / concentration of the catalyst provided (e.g., in a polymer or solvent), the amount of component (d) present will be in the range of 0.001 wt% to 3.0 wt% of the composition, alternatively 0.001 wt% to 1.5 wt% of the composition, alternatively 0.01 wt% to 1.5 wt% of the composition, alternatively 0.01 wt% to 0.10 wt% of the organosilicon coating composition that can be hydrosilylation cured;

[0162] e) One or more organosilicon resins containing unsaturated groups selected from alkenyl groups, alkynyl groups or mixtures of alkenyl groups and alkynyl groups, the one or more organosilicon resins being selected from T organosilicon resins (silsesquioxanes), DT organosilicon resins, MQ organosilicon resins, MDT organosilicon resins, MTQ organosilicon resins, QDT organosilicon resins or mixtures thereof, in an amount of 1 wt% - 60 wt% of the composition, alternatively 1 wt% - 40 wt%;

[0163] f) An adhesion promoter selected from one or more monoacrylates, diacrylates or methacrylates; epoxy group-containing alkoxysilanes, vinyl group-containing alkoxysilanes, alkoxysilanes containing methacrylic or acrylic groups and mixtures and / or reaction products of the following substances:

[0164] i) One or more alkoxysilanes having an epoxy group in the molecule, in an amount of 0.1 wt% to 5 wt% of the composition, alternatively 0.5 wt% to 3 wt%, alternatively 0.5 wt% to 2 wt% of the composition;

[0165] ii) A linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxyl or alkoxy group per molecule, in an amount of 0.1 wt%

[0166] to 5 wt% of the composition, alternatively 0.1 wt% to 3 wt%, alternatively 0.1 wt% to 2 wt% of the composition; and

[0167] iii) an organometallic condensation reaction catalyst comprising an organotitanium, organoaluminum or organozirconium compound, in an amount of 0.1 wt% to 5 wt% of the composition, alternatively 0.1 wt%

[0168] to 3 wt%, alternatively 0.1 wt% to 2 wt% of the composition; or a mixture thereof;

[0169] wherein the adhesion promoter (f) is usually present in the composition in a cumulative amount of 0.3 wt% to 6 wt% of the composition, alternatively 0.3 wt% to 4 wt% of the composition for (f)(i), (ii) and (iii); the composition can be any combination within the above ranges, provided that the total weight % is 100 wt%.

[0170] Typically, when stored before use, the hydrosilylation-curable silicone coating composition for coating materials and / or airbags is stored in two parts (Part A and Part B) to keep the components (c) (crosslinking agent) and (d) hydrosilylation-curing catalyst separate to avoid premature curing. Usually, the Part A composition will contain the components (a) polymer, (b) filler blend and (d) hydrosilylation-curing catalyst.

[0171] Part B will contain the components (a), (b) and (c) crosslinking agent and inhibitor (when present).

[0172] The component (e) (i.e., one or more silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups or a mixture of alkenyl groups and alkynyl groups, such as one or more MQ resins) can be present in Part A, Part B or both Part A and Part B as needed. Regarding the adhesion promoter, when using the reaction product of (f)(i), (f)(ii) and (f)(iii), in order to prevent premature reaction, the component f)(iii) is usually stored in Part A and the components f(i) and (ii) are stored in Part B.

[0173] When present in the composition, the additives can be in Part A or Part B, provided that they do not adversely affect the properties of any other components (e.g., catalyst deactivation). The Part A and Part B of the hydrosilylation-curable silicone coating composition described herein are mixed together shortly before use to initiate the curing of the entire composition into a silicone elastomeric material. The composition can be designed to be mixed at any suitable weight ratio, e.g., Part A:Part B can be mixed in a ratio of 10:1 to 1:10, alternatively 5:1 to 1:5, alternatively 2:1 to 1:2 (but most preferably in a weight ratio of 1:1).

[0174] The components in each of Part A and / or Part B can be individually mixed together or can be introduced into the composition in a pre - formed combination, for example, to facilitate mixing of the final composition. For example, components (a) and (b) are typically mixed together before being added with other ingredients to form an LSR polymer base or masterbatch. These can then be mixed with the other ingredients of the directly - prepared portion or can be used to prepare pre - formed concentrates commonly referred to as masterbatches in the industry.

[0175] In this case, to facilitate mixing of the components, one or more masterbatches can be used to successfully mix the components to form the Part A and / or Part B compositions.

[0176] Parts A and B of the composition can be prepared by combining all of their respective components at ambient temperature. Any mixing techniques and devices described in the prior art can be used for this purpose. The particular device to be used will depend on the components and the viscosity of the final composition. Suitable mixers include, but are not limited to, paddle mixers such as planetary mixers and kneader - type mixers. It may be desirable to cool the components during mixing to avoid premature curing of the composition.

[0177] Before use, the corresponding Part A and Part B compositions are mixed together in the desired ratio.

[0178] As part of the methods herein, the coating compositions as described above can be applied to textile materials or airbag substrates (such as one - piece woven (OPW) airbag substrates or textile materials for cut - and - sewn seam - sealed (CSSS) airbags) by any suitable known techniques. These techniques include spraying, gravure coating, bar coating, coating by knife - over - roll, coating by knife - over - air, filling, dipping, and screen printing.

[0179] The hydrosilylation - curable silicone coating composition is designed for coating cut - and - sewn seam - sealed (CSSS) airbag textiles or one - piece woven (OPW) airbags to be used as frontal airbags and / or front - center airbags, which are designed to act as a buffer pad at the impact point, especially during a collision with the front or rear of a vehicle (i.e., frontal or rear collision).

[0180] Curing of the hydrosilylation - curable silicone coating composition after it has been applied to the woven fabric is typically carried out by heating the composition at a temperature of 150 °C to 200 °C for up to 5 minutes, alternatively 30 seconds to 2 minutes.

[0181] Although it is not preferred, the composition can be applied in multiple layers. Generally, the hydrosilylation - curable silicone coating composition does not require a primer coat between it and the textile material. Additionally, although a top coat can also be applied over the resulting coating, this is generally considered unnecessary.

[0182] The present disclosure includes a textile material or an airbag substrate, e.g., a one-piece woven (OPW) airbag substrate or a cut and sewn seam seal (CSSS) airbag having a cured coating of a hydrosilylation-curable silicone coating composition thereon, the cured coating having an average dry coating weight of 10 g / m 2 to 50 g / m 2 optionally 15 g / m 2 to 40 g / m 2 optionally 15 g / m 2 to 35 g / m 2 g / m 2 optionally 20 g / m 2 to 35 g / m 2 as determined according to ISO 3801.

[0183] The textile material or airbag substrate (e.g., a one-piece woven (OPW) airbag substrate or a cut and sewn seam seal (CSSS) airbag) can be made of any suitable woven fabric (especially a plain weave fabric, but can be e.g., a knitted or non-woven fabric). The fabric can be made of synthetic fibers or a blend of natural and synthetic fibers, e.g., polyamide fibers such as nylon 6, nylon 66, and nylon 46; polyester fibers such as polyethylene terephthalate and polybutylene terephthalate; polyimide, polyethylene, polypropylene, polyester-cotton, polyacrylonitrile fiber fabric, aromatic polyamide fiber fabric, polyetherimide fiber fabric, polysulfone fiber fabric, carbon fiber fabric, rayon fiber fabric, and / or glass fiber. For example, polyamide fiber fabric or polyester fiber fabric is preferably used for applications requiring high strength, such as automotive one-piece woven airbags.

[0184] Before coating with the liquid curable silicone rubber composition, the substrate is preferably washed with water and dried.

[0185] For use as a one-piece woven airbag textile material, the textile material should be flexible enough to be able to be folded into a relatively small volume and also strong enough to withstand high-speed deployment, e.g., under the influence of an explosive. Polyamide and polyester fibers are particularly preferred for manufacturing airbag textiles; however, it may be difficult to obtain coatings that adhere to polyamide and polyester airbags, and thus the need for an adhesion promoter such as component (f) in the above compositions as the coating compositions described above requires good adhesion to plain-woven nylon and polyester textile materials. Thus, the coating compositions described herein are designed to have particularly good adhesion and film-forming properties upon first contact with the textile material such that film formation on the surface of the coated textile material is uniform. Preferably, they also have good penetration into the textile material in order to be able to achieve the desired average dry coating weight, e.g., 10 g / m 2 to 50 g / m 2 Optionally 15 g / m 2 to 40 g / m 2 Optionally 15 g / m 2 to 35 g / m 2 g / m 2 Optionally 20 g / m 2 to 35 g / m 2 , as determined according to ISO 3801 as previously shown.

[0186] It has been found that the use of a hydrotalcite and nesquehonite filler blend (b) in the coating instead of a silica reinforcing filler and / or a calcium carbonate filler gives surprisingly good results in / on textile material / airbag coatings cured from the organosilicon coating compositions curable by hydrosilylation described herein. Before curing, the composition has good flowability on the substrate surface such that an acceptable thin coating can be achieved on the substrate after curing because the hydrotalcite and nesquehonite filler blend (b) does not cause a problematic shear-thinning effect. However, the cured coating obtained on the textile material / airbag retains good mechanical property results after curing, e.g., 100% tensile modulus, as well as good flame retardancy and advantageously improved edge combing resistance.

[0187] Thus, a coating composition utilizing a blend of hydromagnesite and huntite as a filler in a hydrosilylation-curable silicone coating composition as described herein can be used as a coating for textile materials, such as for screen printing, as a base coating for silicone leather, as an adhesive layer coating between a textile and a silicone coating, and especially for use in airbags (e.g., cut and sewn seam seal (CSSS) airbags or one-piece woven airbag designs and both types of airbags, especially those for providing cushioning to vehicle occupants after a frontal or rear collision, rather than for side airbags which tend to require a relatively long inflation period) or as a coating material for airbags, and also for, e.g., the escape slides of airplanes. The hydrosilylation-curable silicone coating composition herein is designed to be directly coated onto the material / airbag and generally will not be used as a topcoat over an intermediate coating directly applied onto the fabric / airbag. Additionally, such coatings as described herein will not require a topcoat applied thereto to function. Examples

[0188] In the following examples, unless otherwise stated, the hydrosilylation-curable silicone coating composition is defined in weight percent (wt.%).

[0189] By infrared spectroscopy, vinyl group and Si-H group contents are measured according to ASTM E168 using the standard measurements of carbon double bond elongation and silicone hydrogen bond elongation, respectively.

[0190] Determination of viscosity

[0191] Unless otherwise specified, all viscosity measurements given for the individual components are made according to ASTM D1084 Method B using a Brookfield DVIII rotational viscometer with the CP-52 rotor most suitable for measuring viscosity at a specific rpm. Unless

[0192] The compositions of Comparative Examples C.1 to 6 and Examples Ex.1 to 6 are disclosed in Tables 1a and 1b, respectively.

[0193] Table 1a: Composition of Comparative Examples 1 to 6 (wt%)

[0194] Component type C.1 C.2 C.3 C.4 C.5 C.6 Polymer 1 60.01 30.06 20.06 10.06 Silicone resin 1 36.00 65.00 94.06 65.00 65.00 65.00 LSR matrix 30.06 <![CDATA[CaCO3]]> 10.00 20.00 Crosslinking agent 1 2.15 3.10 4.10 3.10 3.10 3.10 Ethynylcyclohexanol (ETCH) 0.02 0.02 0.02 0.02 0.02 0.02 Karstedt catalyst (5,000 ppm Pt) 0.32 0.32 0.32 0.32 0.32 0.32 Adhesion catalyst 0.80 0.80 0.80 0.80 0.80 0.80 Glycidoxypropyltrimethoxysilane 0.70 0.70 0.70 0.70 0.70 0.70 H / Vi ratio 1.6:1 1.6:1 1.6:1 1.6:1 1.6:1 1.6:1

[0195] In Table 1a :

[0196] Polymer 1 is dimethylvinylsiloxy-terminated dimethylsiloxane having a vinyl content of 0.085 weight % and a viscosity of 57,000 mPa·s at 25 °C (ASTM D 1084 Method B, rotor CP-52, 1 rpm).

[0197] Silicone resin 1 is a mixture of 27 wt% MQ resin (M 37 M Vi 5Q 58 OH8) in Polymer 1, and the polymer has a viscosity of 60,000 mPa·s at 25 °C (ASTM D 1084 Method B, rotor CP-52, 1 rpm).

[0198] LSR matrix 1 is a combination of 27 wt% fumed silica in Polymer 1.

[0199] CaCO3 is Hakuenka coated with fatty acid TM CC-R precipitated calcium carbonate, which is commercially available from Shiraishi Calcium Kaisha, Ltd.

[0200] Crosslinker 1 is trimethyl-capped dimethylmethylhydrogensiloxane, which has a viscosity of about 15 mPa·s at 25 °C (ASTM D 1084 Method B, rotor CP-52, 10 rpm).

[0201] Adhesion catalyst is 50 wt% zirconium(IV) acetylacetonate (Zr(AcAc)4) in 50 wt% dimethylvinyl-capped polydimethylsiloxane. The dimethylvinyl-capped polydimethylsiloxane has a viscosity of about 9000 mPa·s at 25 °C (ASTM D 1084 Method B, rotor CP-52, 3 RPM) and a vinyl content of 0.225%.

[0202] Table 1b: Composition of Ex.1 to Ex.6 (wt%)

[0203] Component type Ex.1 Ex.2 Ex.3 Ex.4 Ex.5 Ex.6 Polymer 1 20.06 10.06 20.06 10.06 20.06 10.06 Silicone resin 1 65.00 65.00 65.00 65.00 65.00 65.00 HMH 1 10.00 20.00 HMH 2 10.00 20.00 HMH 3 10.00 20.00 Crosslinking agent 1 3.10 3.10 3.10 3.10 3.10 3.10 Ethynylcyclohexanol (ETCH) 0.02 0.02 0.02 0.02 0.02 0.02 Karstedt catalyst (5,000 ppm Pt) 0.32 0.32 0.32 0.32 0.32 0.32 Adhesion catalyst 0.80 0.80 0.80 0.80 0.80 0.80 Glycidoxypropyltrimethoxysilane 0.70 0.70 0.70 0.70 0.70 0.70 H / Vi ratio 1.6:1 1.6:1 1.6:1 1.6:1 1.6:1 1.6:1

[0204] Except for using three alternative blends of hydromagnesite and magnesite, the components of Ex. 1 to 6 are the same as those indicated above.

[0205] HMH 1 is a blend of hydromagnesite and magnesite surface-treated with stearic acid, which is commercially available as UltraCarb TM 1251 from LKAB Minerals AB, Luleå, Sweden.

[0206] HMH 2 is a blend of hydrophobic-treated hydromagnesite and magnesite, which is commercially available as UltraCarb TM 1253 from LKAB Minerals AB, Luleå, Sweden.

[0207] HMH 3 is a blend of hydrotalcite and huntite surface-treated with stearic acid and can be used as UltraCarb TM LH3C was commercially obtained from LKAB Minerals AB in Luleå, Sweden.

[0208] Sample preparation process

[0209] For these laboratory examples, the compositions are not prepared in two parts as they are used immediately. In a commercial situation, they would be prepared in two parts to prevent curing during storage.

[0210] When silicone resin 1 and the LSR matrix were initially mixed together in a FlackTek SpeedMixer (model DAC 400.2VAC-LR), polymer 1 and silicone resin 1 were initially premixed together in all comparative examples and examples except C.3 (without polymer 1) and C.4. Then the remaining components of each composition of the comparative examples and examples were added and mixed into the composition using a high-speed mixer.

[0211] Using an AR 2000 rheometer from TA Instruments, the viscosity of the resulting compositions was evaluated at three alternative shear rates at 25 °C according to Dow Silicones Corporation Corporate test method CTM 1094. The results are depicted in Table 2a (comparative examples) and Table 2b (examples) below.

[0212] Table 2a: Rheological tests of C.1 to C.6 at 25 °C according to CTM 1094 (Pa·s)

[0213] Tested property C.1 C.2 C.3 C.4 C.5 C.6 Viscosity (0.1 / s) 54 47 44 395 55 73 Viscosity (1.0 / s) 55 48 45 210 56 74 Viscosity (10.0 / s) 54 48 45 118 55 70

[0214] Table 2b: Rheological tests of Ex.1 to Ex.6 at 25 °C according to CTM 1094 (Pa·s)

[0215] Tested property Ex.1 Ex.2 Ex.3 Ex.4 Ex.5 Ex.6 Viscosity (0.1 / s) 55 74 56 73 56 72 Viscosity (1.0 / s) 56 75 56 74 56 72 Viscosity (10.0 / s) 55 72 55 71 55 69

[0216] It can be seen that the compositions herein have consistent viscosity values at different shear rates, indicating that the blend of hydrotalcite and huntite does not produce a shear-thinning effect. In contrast, comparative example C.4 shows a significant shear-thinning effect when the only filler present is fumed silica.

[0217] Then the mechanical and coating properties of the compositions of the examples and comparative examples were evaluated.

[0218] Mechanical property tests were carried out using 2 mm thick sheets of the cured products of each example and comparative example composition. The sheets were prepared by compression molding and cured at about 120 °C for 10 minutes. The samples were not post-cured.

[0219] Method used herein for measuring the mechanical properties of silicone rubber

[0220] The hardness of the silicone rubber samples prepared and cured as described above was measured by a Shore A durometer according to ASTM D 2240. The tensile strength, elongation at break, and modulus at 100% elongation were determined according to ASTM D412.

[0221] The tear strength was determined using Die B according to ASTM D624.

[0222] The specific gravity was determined according to ASTM D792.

[0223] The results of the mechanical property tests are depicted in Tables 3a and 3b below.

[0224] Table 3a: Mechanical properties of Comparative Examples C.1 to C.6

[0225] Tested property C.1 C.2 C.3 C.4 C.5 C.6 Hardness (Shore A) 22 31 43 40 41 49 Tensile strength (MPa) 1.7 3.7 5.1 5.7 3.8 4.1 Elongation at break (%) 215 316 392 550 314 342 Modulus at 100% elongation (MPa) 0.46 1.28 2.98 1.51 1.94 2.48 Tear strength (kN / m) 6.84 14.60 24.65 31.84 14.87 17.46 <![CDATA[Specific gravity (g / cm 3 )]]> 0.986 1.002 1.016 1.052 1.064 1.144

[0226] Table 3b: Mechanical properties of Examples Ex.1 to Ex.6

[0227] Tested property Ex.1 Ex.2 Ex.3 Ex.4 Ex.5 Ex.6 Hardness (Shore A) 39 48 38 46 40 48 Tensile strength (MPa) 4.3 4.7 4.3 4.5 3.7 4.2 Elongation at break (%) 337 412 350 370 292 356 Modulus at 100% elongation (MPa) 2.13 2.56 1.97 2.57 1.86 2.33 Tear strength (kN / m) 18.22 19.12 19.90 24.65 18.79 23.36 <![CDATA[Specific gravity (g / cm 3 )]]> 1.072 1.148 1.070 1.147 1.066 1.141

[0228] It can be seen that when using a blend of hydromagnesite and nesquehonite, the mechanical properties are maintained.

[0229] The coated fabric tests according to Directive No. 99040180 of the European Airbag Standardization Committee (EASC) (dated December 11, 2009) prepared and evaluated samples of coated textile materials. Coatings were applied to 470 dtex nylon (PA66) textile materials using the compositions of each example and the comparative example compositions. The compositions were applied to the 470 dtex nylon (PA66) textile materials using a Mathis laboratory coater, which is commercially available from Werner Mathis U.S.A., Inc. in the United States. The coating temperature used was 190 °C, the coating time was 1 minute, and the wet coating weight was 25 g / m². 2 The fabric was coated in the warp direction.

[0230] The textile material samples were then tested. These textile material samples were coated with cured coatings made from the compositions of Comparative Examples C.1 to 6 and Ex.1 to 6 and tested in the warp and weft directions for 3.12 flammability according to ISO 3795, 3.15 edge combing resistance according to ASTM D6479, and 3.25 flex abrasion according to ISO 5981. The results are depicted in Tables 4a and 4b, Tables 5a and 5b, and Tables 6a and 6b, respectively.

[0231] Table 4a: Flammability of coatings made from Comparative Examples C.1 to C.6 on 470 dtex nylon textile material according to ISO 3795 (mm / min) Target

[0232] Warp average C.1 C.2 C.3 C.4 C.5 C.6 Weft average <80 106 75 83 74 58 38 Table 4b: Flammability of coatings made from Ex.1 to Ex.6 on 470 dtex nylon textile material according to ISO 3795 (mm / min) <80 97 83 64 69 49 29

[0233] Target Ex.1

[0234] Ex.2 Ex.3 Ex.4 Ex.5 Ex.6 Warp average Weft average Table 5a: Edge combing resistance of coatings made from Comparative Examples C.1 to C.6 on 470 dtex nylon textile material according to ASTM D6479 (N) <80 60 31 45 32 52 42 Target <80 48 40 47 38 53 35

[0235] It can be seen that the use of a blend of hydromagnesite and nesquehonite as a filler in combination with silicone resin results in a significant improvement in flammability.

[0236] Warp average Weft average

[0237] Target C.1 C.2 C.3 C.4 C.5 C.6 Warp average Weft average Table 5b: Edge combing resistance of coatings made from Ex.1 to Ex.6 on 470 dtex nylon textile material according to ASTM D6479 (N) Target Ex.1 Ex.2 Ex.3 Ex.4 Ex.5 Ex.6 Warp average Weft average >450 412 475 510 679 609 781 Zonal average value >450 424 424 491 640 512 673

[0238] Table 5b: Edge combing resistance (N) of the coatings made from Ex.1 to Ex.6 on 470 dtex nylon textile materials according to ASTM D6479 Target

[0239] Ex.1 Ex.2 Ex.3 Ex.4 Ex.5 Ex.6 Meridional average value Zonal average value >450 484 613 526 582 568 746 Table 6a: Flex abrasion (number of strokes) of the coatings made from Comparative Examples 1 to 6 on 470 dtex nylon textile materials according to ISO5981 >450 485 572 452 556 525 700

[0240] It can be seen that when the working examples are compared with C1, C2, and C3 without added filler, the examples show a significant improvement in edge combing resistance. However, when the examples herein are compared with C4, C5, and C6 filled with pyrogenic silica (C.4) and calcium carbonate (C5 and C6), it can be seen that the examples maintain edge combing resistance similar to that of C4, C.5, and C.6, if not more important, equally important.

[0241] Target Meridional direction

[0242] Qualified C.1 C.2 C.3 C.4 C.5 C.6 Qualified >600 Qualified Qualified Qualified Qualified Zonal direction Qualified Qualified >600 Qualified Qualified Qualified Qualified Table 6b: Flex abrasion (number of strokes) of the coatings made from Ex.1 to Ex.6 on 470 dtex nylon textile materials according to ISO5981 Target

[0243] Ex.1 Ex.2

[0244] Ex.3 Ex.4 Ex.5 Ex.6 Meridional direction Qualified Qualified Qualified >600 Qualified Qualified Qualified Zonal direction Qualified Qualified Qualified >600 Qualified Qualified Qualified ​ ​ ​

[0245] It can be seen that using a blend of hydromagnesite and nesquehonite as a filler instead of silica and / or calcium carbonate gives similar flex abrasion results.

[0246] Accordingly, it is understood that the hydrosilylation-curable silicone coating composition described herein containing a silicone resin (e.g., MQ resin) and a blend of hydromagnesite and nesquehonite as fillers exhibits good fluidity without a shear thinning effect, and the coated textile material using the coating made from the composition maintains its edge combing resistance, adhesion, and mechanical strength, and can thus be used for coating cut and sewn seam seal (CSSS) airbag textiles or one-piece woven (OPW) airbags to be used as front airbags and / or front center airbags, which are designed to act as a buffer pad at the impact point, especially when colliding with the front or rear of the vehicle (i.e., frontal or rear collision). As previously shown, it is also a suitable coating for textile materials, such as for screen printing, as a base coating for silicone leather, and as an adhesive layer coating between textiles and silicone coatings.

Claims

1. A hydrosilylation-curable silicone coating composition, comprising: a) an organopolysiloxane polymer having a viscosity between 100 mPa·s and 200,000 mPa·s at 25 °C and having at least two unsaturated groups per molecule, said unsaturated groups being selected from alkenyl groups or alkynyl groups; b) a filler blend of hydromagnesite and huntite, said filler blend being capable of being treated with a suitable hydrophobic agent; c) a silicone compound having at least two, alternatively at least three, Si-H groups per molecule; d) a hydrosilylation-curing catalyst; e) one or more silicone resins having unsaturated groups selected from alkenyl groups, alkynyl groups or a mixture of alkenyl groups and alkynyl groups, said one or more silicone resins being selected from T-silicone resins (silsesquioxanes), DT-silicone resins, MQ-silicone resins, MDT-silicone resins, MTQ-silicone resins, QDT-silicone resins or mixtures thereof; f) an adhesion promoter selected from one or more monoacrylates, diacrylates or methacrylates; alkoxysilanes containing epoxy groups, alkoxysilanes containing vinyl groups, alkoxysilanes containing methacrylic groups or alkoxysilanes containing acrylic groups and mixtures and / or reaction products of the following substances: i) one or more alkoxysilanes having epoxy groups in the molecule; ii) linear organopolysiloxane oligomers containing at least one alkenyl group and at least one hydroxyl group or alkoxy group per molecule; and iii) an organometallic condensation catalyst comprising an organotitanium, organoaluminum or organozirconium compound; or mixtures thereof.

2. The hydrosilylation-curable silicone coating composition according to claim 1, wherein component (e) is one or more MQ resins having unsaturated groups selected from alkenyl groups, alkynyl groups or a mixture of alkenyl groups and alkynyl groups and / or T-resins having unsaturated groups selected from alkenyl groups, alkynyl groups or a mixture of alkenyl groups and alkynyl groups.

3. The hydrosilylation-curable silicone coating composition according to claim 1, wherein component (e) is one or more MQ resins having unsaturated groups selected from alkenyl groups, alkynyl groups or a mixture of alkenyl groups and alkynyl groups.

4. The hydrosilylation-curable organosilicon coating composition according to any one of the preceding claims, wherein component (e) is provided as a mixture with some or all of component (a).

5. The hydrosilylation-curable organosilicon coating composition according to any one of the preceding claims, wherein the filler blend of component (b), hydrotalcite and huntite, is hydrophobically treated and / or is present in the composition in an amount of 5.0% to 40% by weight of the composition.

6. A textile material or airbag at least partially coated with an organosilicon coating, which is a cured elastomeric product of the hydrosilylation-curable organosilicon coating composition according to any one of the preceding claims.

7. The textile material or airbag according to claim 6, wherein the average dry coating weight measured according to ISO 3801 is from 10 g / m 2 to 50 g / m 2 .

8. The coated textile material or coated airbag according to claim 6 or 7, wherein the textile material or airbag is made of polyamide or polyester.

9. The coated textile material or coated airbag according to claim 6, 7 or 8, wherein the textile material or airbag is a cut and sewn seam-sealed airbag or a one-piece woven airbag.

10. A method of coating a textile material or airbag by mixing the components of the hydrosilylation-curable organosilicon coating composition according to any one of claims 1 to 5, the method comprising: Coat the textile material or airbag with the composition and cure the hydrosilylation-curable silicone coating composition by heating the composition at a temperature of 150 °C to 200 °C for up to 5 minutes.

11. A coated textile material or coated airbag, which is obtained or can be obtained by coating a textile material or airbag according to claim 10.

12. The coated textile material or coated airbag according to claim 11, wherein the average dry coating weight measured according to ISO 3801 is from 10 g / m 2 to 50 g / m 2 .

13. The coated textile material or coated airbag according to claim 11 or 12, wherein the textile material or airbag is made of polyamide or polyester.

14. The coated textile material or coated airbag according to claim 11, 12 or 13, wherein the textile material or airbag is a cut and sewn seam-sealed airbag or a one-piece woven airbag.

15. Use of the hydrosilylation-curable organosilicon coating composition according to any one of claims 1 to 5 in the manufacture of a cut and sewn seam-sealed airbag or an integral woven airbag or a coated textile material.