Silicone coating

Abstract

The present disclosure relates to a hydrosilylation-curable silicone coating composition comprising a filler blend (b) of hydromagnesite and huntite, a method for coating textile materials and / or airbags with the hydrosilylation-curable silicone coating composition, and textile materials and airbags coated with the cured product of the hydrosilylation-curable silicone coating composition.

Description

[Technical Field]

[0001] The present disclosure relates to hydrosilylation-curable silicone coating compositions, methods for coating textile materials and / or airbags with said hydrosilylation-curable silicone coating compositions, and textile materials and airbags coated with the cured products of the hydrosilylation-curable silicone coating compositions.

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

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

[0004] Airbags and / or textile materials used in the manufacture of airbags can be made from woven or knitted synthetic fibers, such as polyamides such as nylon-6,6, or polyesters such as polyethylene terephthalate. Airbags can be made from flat pieces of textile material that are coated and then sewn together to provide sufficient mechanical strength (commonly referred to as "cut-and-sew, seam-shielded (CSSS) airbags"), or they can be woven together with an integral woven seam (commonly referred to as "one-piece woven (OPW) airbags"). Sewn flat textile material airbags are generally assembled with a coated textile material surface on the inside of the airbag. One-piece woven airbags tend to be coated on the outside of the airbag and are better able to retain gas pressure after deployment and are therefore used in airbags designed to remain inflated for longer periods after a crash, such as side curtain airbags.

[0005] Various airbags are utilized as inflatable safety restraint devices and are designed to inflate and deploy in a crash situation, most notably in a vehicle. Today, it is generally mandatory to have several airbags in a vehicle as a means of providing occupant safety in the event of a crash. These may include front airbags, front center airbags, side airbags, side curtain airbags, thorax airbags, and / or knee airbags.

[0006] Typically, front airbags and / or front center airbags and their inflation mechanisms are hidden within the vehicle trim so that they are not visible during normal vehicle operation. For example, front airbags may be installed within the steering wheel boss on the driver's side of the vehicle and within the dashboard on the passenger's side of the vehicle, behind a plastic flap or door designed to tear open under the force of bag inflation. They are provided to act as a cushion at the point of impact, particularly during a frontal or rearal collision with the vehicle. When a predetermined threshold is reached or exceeded, the airbag control unit triggers ignition of the gas generator propellant, causing the airbag to rapidly inflate. When a vehicle occupant impacts and compresses the bag, gas is designed to escape from the bag in a controlled manner; therefore, these airbags are required to exhibit relatively high breathability to allow the inflated airbag to deflate quickly after the initial collision. 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 they are typically mounted in the headliner above the doors and windows and deploy from near the ceiling along the side windows to protect vehicle occupants from side collisions and resulting rollover events (where the vehicle flips onto its side, upside down, or flips over two or more times). However, side curtain airbags are primarily designed to protect occupants during rollover collisions by retaining their inflated state for a long duration (e.g., exhibiting retention of at least 50% of their initial pressure five seconds after high-pressure inflation), and generally deploy from packing containers stored within the roofline along the vehicle's side windows (and thus have only rear and front sides). Therefore, side curtain airbags are designed not only to provide a cushioning effect but also to provide protection from broken glass and other debris. Therefore, as noted above, it is essential that side curtain airbags remain inflated for several seconds until the end of the rollover period resulting from the collision; i.e., they must retain a large volume of gas and a high gas pressure for a longer period of time throughout a potential rollover.

[0008] Silicone rubber coatings are often provided on textile materials and airbags and are designed to keep the airbag flexible and resistant to temperature fluctuations, aging, and abrasion. These properties are necessary, for example, because airbags can remain unused for extended periods (e.g., several years) before a collision triggers deployment. This requires that such silicone rubber coatings be highly stable over time to prevent the airbag from sticking and ensure smooth deployment even after many years. Such silicone rubber coatings must offer good thermal stability because inflators are typically designed to emit extremely hot gases during inflation that could otherwise inflict burns on the occupant. They are provided to prevent or at least significantly reduce the possibility of the coated textile material catching fire on the occupant. Furthermore, while traditionally utilized silicone airbag coatings offer the advantages of excellent durability, aging, and processability, they also tend to exhibit very low tensile strength and elongation at break properties that do not easily withstand high-pressure inflation unless very thick coatings are utilized.

[0009] In the case of front and rear impact airbags, particularly for CSSS airbags, it has been found that as means for inflating such airbags have been developed, devices such as gas generators have become increasingly mechanically and thermally aggressive, creating additional problems with the stitching of such airbags in addition to the physical constraints associated with deploying an inflatable bag, which can result in tears and opening of the stitching in the silicone elastomer coated textile material, potentially causing tearing, combing (fraying) and even rupture of certain airbags.

[0010] As a result, airbag manufacturers are seeking silicone elastomer coating compositions for their applications that have optimal mechanical properties, particularly good tear strength and edgecomb resistance (the ability of the coated textile material to withstand combing / fraying of the inflatable bag seams). However, the coatings resulting from the curing of such compositions tend to have either good edgecomb resistance or good tear strength. Obtaining a good compromise between these two properties while maintaining good adhesion properties is clearly an industry-wide challenge.

[0011] Silicone airbag coating compositions tend to be hydrosilylation (addition) cure compositions that cure by crosslinking an organopolysiloxane polymer containing 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, used to treat airbag fabrics, for example, on the inside of CSSS-type airbags and on the outside of OPW-type airbags, often contain silicone resins, particularly MQ resins, which provide good flow, high modulus, and flame retardancy due to their excellent solubility in the vinyl organopolysiloxanes used. Typically, such compositions require the addition of reinforcing fillers, such as precipitated silica and / or fumed silica, to ensure that the resulting coated airbag achieves good edge-comb resistance. However, the incorporation of such reinforcing fillers significantly thickens the silicone airbag coating composition, resulting in high viscosity and shear-thinning (non-Newtonian behavior of a fluid in which viscosity decreases under shear strain) when significant amounts of reinforcing silica fillers are used. This requires a low level of silica loading (for example, 10% by weight or less of the composition) to maintain fluidity. Therefore, calcium carbonate (CaCO3) is typically used as an additional filler because it does not have the same shear thinning effect and allows the silicone airbag coating composition to maintain good fluidity at higher filler loading levels. However, there is still a need for alternative solutions to achieve airbag coatings with all the different required properties.

[0012] In this specification, a) an organopolysiloxane polymer having a viscosity of 100 to 200,000 mPa.s at 25°C and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups; b) a filler blend of hydromagnesite, having the structure Mg5(CO3)4(OH)2·4H2O, and huntite, having the structure Mg3Ca(CO3)4, which may be treated with a suitable hydrophobizing agent; c) organosilicon compounds having at least two or three Si-H groups per molecule; d) a hydrosilylation curing catalyst; e) one or more silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups, or mixtures of alkenyl and alkynyl groups, 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) one or more monoacrylates, diacrylates or methacrylates, epoxy-containing alkoxysilanes, vinyl-containing alkoxysilanes, alkoxysilanes containing methacryl groups or alkoxysilanes containing acrylic groups, and i) one or more alkoxysilanes having an epoxy group in the molecule; ii) a linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxy or alkoxy group per molecule; and iii) an adhesion promoter selected from mixtures and / or reaction products of an organometallic condensation reaction catalyst comprising an organotitanium compound, an organoaluminum compound, or an organozirconium compound, or a mixture thereof.

[0013] Also provided herein is a textile material or airbag at least partially coated with a silicone coating that is the cured elastomeric product of the hydrosilylation-curable silicone coating composition described above.

[0014] In this specification, a) an organopolysiloxane polymer having a viscosity of 100 to 200,000 mPa.s at 25°C and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups; b) a filler blend of hydromagnesite, having the structure Mg5(CO3)4(OH)2·4H2O, and huntite, having the structure Mg3Ca(CO3)4, which may be treated with a suitable hydrophobizing agent; c) organosilicon compounds having at least two or three Si-H groups per molecule; d) a hydrosilylation curing catalyst; e) one or more silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups, or mixtures of alkenyl and alkynyl groups, 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) one or more monoacrylates, diacrylates or methacrylates, epoxy-containing alkoxysilanes, vinyl-containing alkoxysilanes, alkoxysilanes containing methacryl groups or alkoxysilanes containing acrylic groups, and i) one or more alkoxysilanes having an epoxy group in the molecule; ii) a linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxy or alkoxy group per molecule; iii) mixing the components of a hydrosilylation-curable silicone coating composition, including an adhesion promoter selected from the group consisting of a mixture and / or reaction product of an organometallic condensation reaction catalyst comprising an organotitanium compound, an organoaluminum compound, or an organozirconium compound, or a mixture thereof; Also provided is a method of coating a textile material or an airbag by coating the textile material or airbag with the composition and curing the composition.

[0015] In this specification, a) an organopolysiloxane polymer having a viscosity of 100 to 200,000 mPa.s at 25°C and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl groups or alkynyl groups; b) a filler blend of hydromagnesite, having the structure Mg5(CO3)4(OH)2·4H2O, and huntite, having the structure Mg3Ca(CO3)4, which may be treated with a suitable hydrophobizing agent; c) organosilicon compounds having at least two or three Si-H groups per molecule; d) a hydrosilylation curing catalyst; e) one or more silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups, or mixtures of alkenyl and alkynyl groups, 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) one or more monoacrylates, diacrylates or methacrylates, epoxy-containing alkoxysilanes, vinyl-containing alkoxysilanes, alkoxysilanes containing methacryl groups or alkoxysilanes containing acrylic groups, and i) one or more alkoxysilanes having an epoxy group in the molecule; ii) a linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxy or alkoxy group per molecule; iii) mixing the components of a hydrosilylation-curable silicone coating composition, including an adhesion promoter selected from the group consisting of a mixture and / or reaction product of an organometallic condensation reaction catalyst comprising an organotitanium compound, an organoaluminum compound, or an organozirconium compound, or a mixture thereof; Also provided is a coated textile material or a coated airbag obtained or obtainable by coating a textile material or an airbag with the composition and curing the composition.

[0016] The combination of components (b) and (e) has surprisingly been found to provide a coating composition with good flowability without shear thinning effects, and upon post-cure, imparts improved edge comb resistance, maintained adhesion, and mechanical strength, which is remarkable and surprising considering that such results are achieved in the absence of fumed and precipitated silica, and preferably in the absence of calcium carbonate.

[0017] While the hydrosilylation-curable silicone coating compositions herein can be used in screen printing as a base coating for silicone leather or as a binder layer coating between a textile and a silicone coating, the present disclosure is directed to textile materials used to make cut-and-sew seam-shielded (CSSS) airbags or one-piece woven airbag designs, and both types of airbags, particularly those used to cushion occupants after a front or rear collision, but not side airbags, which tend to require relatively long inflation periods. Such coating compositions are applied to textile material surfaces designed to be on the inside of CSSS-type airbags and, in each case, as coatings for the outside of one-piece woven airbags designed to cushion front and rear collisions. They are not designed for use as coatings for curtain or side-type airbags, which require long inflation times. The hydrosilylation-curable silicone coating compositions herein are designed to be coated directly onto materials / airbags and are generally not used as topcoats over intermediate coatings applied directly onto fabrics / airbags. Furthermore, coatings such as those described herein do not require a topcoat applied thereto in order to function.

[0018] The hydrosilylation-curable silicone coating composition utilized to prepare the coating comprises the following components:

[0019] (a) Organopolysiloxane polymer Component (a) of the hydrosilylation-curable silicone coating composition is one or more organopolysiloxane polymers having a viscosity of 100 to 200,000 mPa.s at 25°C and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl or alkynyl groups. Each organopolysiloxane polymer of component (a) contains a plurality of siloxy units of formula (I): R' a SiO (4-a) / 2 (I)

[0020] The subscript "a" is 0, 1, 2, or 3.

[0021] Siloxy units may be described by shorthand nomenclature, i.e., "M," "D," "T," and "Q," where R' is usually an aliphatic hydrocarbyl group, a substituted aliphatic hydrocarbyl group, an aromatic group, or a substituted aromatic group, as further described below, and alternatively an alkyl group, typically a methyl group. M units are siloxy units where a=3, i.e., R'SiO 1 / 2 and the D units are siloxy units where a=2, i.e., R'2SiO 2 / 2 and the T unit is a siloxy unit where a=1, i.e., R'1SiO 3 / 2 and the Q units are siloxy units where a=0, i.e., SiO 4 / 2 The organopolysiloxane polymer of component (a) is substantially linear, but may contain a certain amount of branching due to the presence of T units (described above) within the molecule, such that the average value of a in structure (I) is about 2.

[0022] The unsaturated groups in component (a) can be located at either the terminal or pendant positions of the organopolysiloxane polymer, or at both positions. The unsaturated groups in component (a) can be alkenyl or alkynyl groups, as described above. Each alkenyl group, if present, can contain, for example, 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, or alternatively 2 to 6 carbon atoms. If present, alkenyl groups can be exemplified by, but not limited to, vinyl, allyl, methallyl, propenyl, hexenyl, and cyclohexenyl groups. If present, each alkynyl group can have 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, or 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 group of component (a) include vinyl, propenyl, isopropenyl, butenyl, allyl, and 5-hexenyl.

[0023] In formula (I), each R' other than the unsaturated group is independently selected from an aliphatic hydrocarbyl group, a substituted aliphatic hydrocarbyl group, an aromatic group, or a substituted aromatic group. Each aliphatic hydrocarbyl group can be exemplified by, but not limited to, an alkyl group having 1 to 20 carbons per group, alternatively 1 to 15 carbons per group, alternatively 1 to 12 carbons per group, alternatively 1 to 10 carbons per group, or alternatively 1 to 6 carbons per group, or a cycloalkyl group such as cyclohexyl. Specific examples of alkyl groups include methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl, alternatively methyl and ethyl groups. The substituted aliphatic hydrocarbyl group is preferably a non-halogenated substituted alkyl group.

[0024] Aliphatic non-halogenated organyl groups are exemplified by, but not limited to, the above-mentioned alkyl groups, polyoxyalkylene groups, carbonyl groups, alkoxy groups, and oxygen-containing groups such as hydroxyl groups, each of which has a suitable nitrogen-containing group such as an amide group or an imide group as a substituent. Further organyl groups may include sulfur-containing groups, phosphorus-containing groups, and boron-containing groups. Examples of aromatic or substituted aromatic groups are phenyl groups and substituted phenyl groups having the above-mentioned substituents.

[0025] Component (a) may be selected, for example, from polydimethylsiloxane, alkylmethylpolysiloxane, alkylarylpolysiloxane, or copolymers thereof (reference to alkyl means any suitable alkyl group, alternatively an alkyl group having 2 or more carbons), provided that each polymer has the viscosity of organopolysiloxane polymer (a), which should be 100 to 200,000 mPa.s at 25°C.

[0026] Thus, component (a) may be, for example, the following: The alkyl group may be a dialkylalkenyl-terminated polydimethylsiloxane such as a dimethylvinyl-terminated polydimethylsiloxane, a dialkylalkenyl-terminated dimethylmethylphenylsiloxane such as a dimethylvinyl-terminated dimethylmethylphenylsiloxane, a trialkyl-terminated dimethylmethylvinylpolysiloxane, a dialkylvinyl-terminated dimethylmethylvinylpolysiloxane copolymer, a dialkylvinyl-terminated methylphenylpolysiloxane, a dialkylalkenyl-terminated methylvinylmethylphenylsiloxane, a dialkylalkenyl-terminated methylvinyldiphenylsiloxane, a dialkylalkenyl-terminated methylvinylmethylphenyldimethylsiloxane, a trimethyl-terminated methylvinylmethylphenylsiloxane, a trimethyl-terminated methylvinyldiphenylsiloxane, or a trimethyl-terminated methylvinylmethylphenyldimethylsiloxane.

[0027] In each case, the viscosity of component (a) organopolysiloxane polymer (a) should be 100 to 200,000 mPa.s at 25° C., alternatively 1000 to 150,000 mPa.s at 25° C., alternatively 1000 mPa.s to 125,000 mPa.s, alternatively 1000 mPa.s to 100,000 mPa.s at 25° C. Unless otherwise indicated, all viscosity measurements given are measured according to ASTM D1084 Method B using a Brookfield DV III rotational viscometer equipped with the most appropriate spindle CP-52 for viscosity measured at 1 rpm. Typically, the alkenyl and / or alkynyl content, e.g., vinyl content, of the polymer is 0.01 to 3 weight percent of component (a), alternatively 0.01 to 2.5 weight percent of component (a), alternatively 0.001 to 2.0 weight percent of component (a), for each organopolysiloxane polymer containing at least two silicon-bonded alkenyl groups per molecule, alternatively 0.01 to 1.5 weight percent of component (a) for the organopolysiloxane polymer or each organopolysiloxane polymer containing at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl or alkynyl groups per molecule of component (a). The alkenyl / alkynyl content of component (a) is determined using quantitative infrared analysis according to ASTM E168.

[0028] Component (a) may be present in the composition in an amount of from 40% to about 80% by weight of the composition, alternatively from 45 to 80% by weight of the composition, alternatively from 50 to 80% by weight of the composition. Typically, component (a) is present in an amount that is the difference between 100% by weight and the cumulative weight % of the other components / ingredients of the composition.

[0029] Component (b) Filler blend of hydromagnesite and huntite (HMH) Component (b) of the hydrosilylation-curable silicone coating composition is a filler blend of hydromagnesite, having the structure Mg5(CO3)4(OH)2·4H2O, and huntite, having the structure Mg3Ca(CO3)4, which may be treated with a suitable hydrophobizing agent.

[0030] Hydromagnesite is a hydrated magnesium carbonate mineral, sometimes called light magnesium carbonate.

[0031] Typically, both hydromagnesite and huntite are hydrophilic in nature and can be treated with a hydrophobic treatment agent to render them hydrophobic. Because the surface treatment makes the filler easily wettable by the organopolysiloxane polymer (a), these surface-modified filler blends (b) do not aggregate and can be homogeneously incorporated into the organopolysiloxane polymer (a). Blends of hydromagnesite and huntite are commercially available, for example, from LKAB Minerals AB of Lulea, Sweden, under the trade names UltraCarb™ 1251, UltraCarb™ 1253, and UltraCarb™ LH3C. Such filler blends contain particles with a particle size of 0.5 to 15 μm, as measured using Malvern laser diffraction (data sheet). It is understood that huntite particles typically have a particle size of about 1.0 μm or less, much smaller than the particle size of hydromagnesite particles.

[0032] Typically, both hydromagnesite and huntite particles (b) can be surface-treated with any low molecular weight organosilicon compound disclosed in the art, which can be applied to prevent creping of organosiloxane compositions during processing.For example, organosilanes, polydiorganosiloxanes, or organosilazanes such as hexaalkyldisilazanes, short-chain siloxane diols, or fatty acids such as stearic acid or fatty acid esters such as stearic acid esters can be used to make the filler hydrophobic, thus making it easier to handle and to obtain a homogeneous mixture with other components. Specific examples of organosilicon compounds include, but are not limited to, silanol-terminated trifluoropropylmethylsiloxane, silanol-terminated vinylmethylsiloxane, tetramethyldi(trifluoropropyl)disilazane, tetramethyldivinyldisilazane, silanol-terminated MePh siloxane, liquid hydroxyl-terminated polydiorganosiloxanes containing an average of 2 to 20 repeating diorganosiloxane units per molecule, hexaorganodisiloxane, and hexaorganodisilazane. In one embodiment of the present specification, hydromagnesite and huntite particles are treated with a fatty acid, such as stearic acid, or a fatty acid ester, such as stearate, to render the filler hydrophobic. A small amount of water may be added along with the treating agent as a processing aid.

[0033] The hydromagnesite and huntite blend of filler (b) can be pretreated before being introduced into the hydrosilylation-curable silicone coating composition, or it can be treated in situ (i.e., in the presence of at least a portion of component (a) of the hydrosilylation-curable silicone coating composition herein) by mixing the fillers together in component (a) above room temperature until the fillers are completely treated. When the filler blend is treated with a fatty acid or fatty acid ester, alternatively stearic acid or one or more stearates, the filler blend is pretreated and introduced into the composition in a treated, and therefore hydrophobic, form. Otherwise, the untreated filler blend (b) is treated with the treating agent in situ in the presence of organopolysiloxane polymer (a), thereby resulting in the preparation of a silicone rubber-based material that can be subsequently mixed with other components.

[0034] In a preferred embodiment, filler blend (b) does not contain silica. In a preferred embodiment, filler blend (b) does not contain calcium carbonate. In a preferred embodiment, filler blend (b) does not contain silica or calcium carbonate.

[0035] The filler blend (b) is present in the composition in an amount from 5.0 to 40% by weight of the composition, alternatively from 7.5 to 35% by weight of the composition, alternatively from 7.5 to 30% by weight of the composition.

[0036] Component (c) Crosslinking Agent Component (c) functions as a crosslinker and is provided in the form of an organosilicon 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 groups) of component (a) and / or the remainder of the composition to form a network structure, thereby curing the composition. Alternatively, some or all of component (c) may have two silicon-bonded hydrogen atoms per molecule. However, such molecules are used as the sole crosslinker only when, for example, polymer (a) has more than two unsaturated groups per molecule, in which case a network can be formed during the curing process. Otherwise, if component (c) partially contains molecules having two silicon-bonded hydrogen atoms per molecule, the molecules may function as chain extenders.

[0037] The molecular structure of the organosilicon compound (c) having at least two or at least three Si-H groups per molecule is not particularly limited and can be a silane, or a linear, branched (linear chain with some branches through the presence of T groups), or cyclic polymer, or silicone resin-based.

[0038] The molecular weight of component (c) is not particularly limited, but the viscosity can be measured using the method described above.

[0039] The silicon-bonded organic group used in component (c) can be exemplified by alkyl groups such as methyl, ethyl, propyl, n-butyl, t-butyl, pentyl, hexyl, etc., aryl groups such as phenyl, tolyl, xylyl, or similar aryl groups, 3-chloropropyl, 3,3,3-trifluoropropyl, or similar halogenated alkyl groups, and is preferably an alkyl group having 1 to 6 carbon atoms, particularly a methyl, ethyl, or propyl group, or a phenyl group. Preferably, the silicon-bonded organic group used in component (c) is an alkyl group, alternatively a methyl, ethyl, or propyl group.

[0040] Examples of organosilicon compounds (c) having at least two, alternatively at least three, Si—H groups per molecule include, but are not limited to: (a) trimethylsiloxy-terminated methylhydrogenpolysiloxane, (b) trimethylsiloxy-terminated polydimethylsiloxane-methylhydrogensiloxane; (c) dimethylhydrogensiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymer; (d) dimethylsiloxane-methylhydrogensiloxane cyclic copolymer; (e)(CH3)2HSiO 1 / 2 Units: (CH3)3SiO 1 / 2 units, and SiO 4 / 2 copolymers and / or silicone resins consisting of units, (f)(CH3)2HSiO 1 / 2 Units and SiO 4 / 2 copolymers and / or silicone resins consisting of units, (g) Methylhydrogensiloxane cyclic homopolymers having 3 to 10 silicon atoms per molecule.

[0041] In one embodiment, component (c) is selected from a methylhydrogenpolysiloxane having both molecular terminals capped with trimethylsiloxy groups, a copolymer of a methylhydrogensiloxane and a dimethylsiloxane having both molecular terminals capped with trimethylsiloxy groups, a dimethylsiloxane having both molecular terminals capped with dimethylhydrogensiloxy groups, and a copolymer of a methylhydrogensiloxane and a dimethylsiloxane having both molecular terminals capped with dimethylhydrogensiloxy groups.

[0042] Component (c) crosslinker is generally present in the hydrosilylation-curable silicone coating composition such that the molar ratio of 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. If this ratio is less than 0.5:1, a sufficiently cured composition will not be obtained. If this ratio is greater than 20:1, the hardness of the cured composition will tend to increase when heated.

[0043] Preferably, the crosslinker is present in an amount such that the molar ratio of silicon-bonded hydrogen atoms of component (c) to total unsaturated groups selected from alkenyl and / or alkynyl groups in 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.

[0044] The silicon-bonded hydrogen (Si-H) content of component (c) is determined using quantitative infrared analysis according to ASTM E168. For the present invention, the ratio of silicon-bonded hydrogen to alkenyl (vinyl) and / or alkynyl is important when relying on a hydrosilylation cure process. Generally, this is determined by calculating the total weight percent of alkenyl groups, e.g., vinyl [V], in the composition and the total weight percent of silicon-bonded hydrogen [H] in the composition; if 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].

[0045] Typically, component (c) is present in an amount 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 of the hydrosilylation-curable silicone coating composition, and alternatively from 0.5% to 10% by weight of the hydrosilylation-curable silicone coating composition, and alternatively from 0.5% to 10% by weight of the hydrosilylation-curable silicone coating composition, 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).

[0046] (d) Hydrosilylation catalyst 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. They are usually selected from catalysts of platinum group metals (platinum, ruthenium, osmium, rhodium, iridium, and palladium) or one or more compounds of such metals. Alternatively, platinum and rhodium compounds are preferred due to the high activity level of these catalysts in hydrosilylation reactions, with platinum compounds being most preferred. In the hydrosilylation (or addition) reaction, hydrosilylation catalysts such as component (d) herein catalyze the reaction between unsaturated groups, usually alkenyl groups, such as vinyl, and Si-H groups.

[0047] 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 aluminum oxide or silicon dioxide, silica gel or powdered charcoal, or a compound or complex of a platinum group metal. Preferably, the platinum group metal is platinum.

[0048] 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 such as hexachloroplatinic acid (Pt oxidation state IV) (Speier's catalyst), chloroplatinic acid in solution in an alcohol such as isooctanol or amyl alcohol (Lamoreaux's catalyst), and complexes of chloroplatinic acid with ethylenically unsaturated compounds such as olefins and organosiloxanes containing ethylenically unsaturated silicon-bonded hydrocarbon groups, such as tetra-vinyl-tetramethylcyclotetrasiloxane-platinum complex (Ashby's catalyst). Usable soluble platinum compounds include, for example, platinum-olefin complexes of the formula (PtCl2.(olefin)2 and H(PtCl3.olefin), in which the use of alkenes 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, is preferred. Other soluble platinum catalysts are, for example, platinum-cyclopropane complexes of the formula (PtCl2C3H6)2, hexachloro- The reaction products of chloroplatinic acid with alcohols, ethers, and aldehydes, or mixtures thereof, or the reaction products of hexachloroplatinic acid and / or its conversion products with vinyl-containing siloxanes such as methylvinylcyclotetrasiloxane in the presence of sodium bicarbonate in an ethanolic solution. Platinum catalysts with phosphorus, sulfur, and amine ligands, such as (Ph3P)2PtCl2, and complexes of platinum with vinyl siloxanes such as sym-divinyltetramethyldisiloxane (Karstedt's catalyst), can also be used.

[0049] Therefore, specific examples of suitable platinum-based catalysts of component (d) include: (i) complexes of chloroplatinic acid with organosiloxanes containing ethylenically unsaturated hydrocarbon groups, as described in U.S. Pat. No. 3,419,593; (ii) chloroplatinic acid in either the hexahydrate or anhydrous form; (iii) platinum-containing catalysts obtained by a process comprising reacting chloroplatinic acid with an aliphatically unsaturated organosilicon compound such as divinyltetramethyldisiloxane; (iv) alkene-platinum-silyl complexes described in U.S. Pat. No. 6,605,734, such as (COD)Pt(SiMeCl) (where “COD” is 1,5-cyclooctadiene), and / or (v) Karstedt's catalyst, which is a platinum divinyltetramethyldisiloxane complex, typically containing about 1% by weight of platinum in a vinylsiloxane polymer. While organic solvents such as toluene have historically been used as alternatives, the use of vinylsiloxane polymers is by far the preferred choice. These are described in U.S. Pat. Nos. 3,715,334 and 3,814,730. In a preferred embodiment, component (d) can be selected from platinum coordination compounds. In one embodiment, hexachloroplatinic acid and its conversion products with vinyl-containing siloxanes, Karstedt's catalyst, and Speier's catalyst are preferred.

[0050] The catalytic amount of the hydrosilylation catalyst is generally 0.01 ppm to 10,000 ppm, alternatively 0.01 to 5,000 ppm, alternatively 0.01 to 3,000 ppm, alternatively 0.01 to 1,000 ppm, based on the weight of the composition in parts by million (ppm). In certain embodiments, the catalytic amount of the catalyst may range from 0.01 to 1,000 ppm, alternatively 0.01 to 750 ppm, alternatively 0.01 to 500 ppm, alternatively 0.01 to 100 ppm, based on the weight of the composition. While the ranges may relate to only the metal content within the catalyst or to the entire catalyst (including its ligands), as specified, typically these ranges relate only to the metal content within the catalyst. The catalyst may be added as a single species or as a mixture of two or more different species. Typically, depending on the form / concentration in which the catalyst is provided, for example, in the polymer or solvent, the amount of component (d) present is in the range of 0.001 to 3.0 wt % of the composition, alternatively 0.001 to 1.5 wt % of the composition, alternatively 0.01 to 1.5 wt %, alternatively 0.01 to 1.0 wt % of the hydrosilylation-curable silicone coating composition.

[0051] (e) one or more silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups, or a mixture of alkenyl and alkynyl groups; The one or more silicone resins of component (e) in the hydrosilylation-curable silicone coating composition are silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups, or mixtures of alkenyl and alkynyl groups, selected from T silicone resins (silsesquioxanes), DT silicone resins, MQ silicone resins, MDT silicone resins, MTQ silicone resins, QDT silicone resins, or mixtures thereof.

[0052] Such resins of component (e) using the MDTQ designation are Q type (SiO ) as shown. 4 / 2 ) Siloxane unit, T type (R 2 1SiO 3 / 2 ) Siloxane unit, D type (R 2 1SiO 3 / 2) siloxane units, and R 2 3SiO 1 / 2 (M) siloxane units. These resins can be divided into two broad categories: silsesquioxanes and silicates. Silsesquioxane or T resins consist primarily of T units and can be synthesized by the hydrolysis and condensation of alkoxysilanes, chlorosilanes, or mixtures thereof. Silicate or MQ resins consist primarily of M and Q units and can be synthesized through the hydrolysis and condensation of alkoxysilanes and chlorosilanes. Alternatively, MQ resins can be synthesized through the polymerization of aqueous alkaline silicates in the presence of acid, followed by reaction with triorganoalkoxysilanes, triorganochlorosilanes, hexaorganodisiloxanes, or mixtures thereof.

[0053] Preferably, component (e) is one or more MQ resins. Typically, the MQ resins of component (e) are SiO 4 / 2 (Q) siloxane unit and R 2 3SiO 1 / 2 (M) a siloxane unit, wherein each R 2 may be the same or different and represent a monovalent group selected from hydrocarbon groups having 1 to 20 carbon atoms, alternatively 1 to 12 carbon atoms. 2 Examples of 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 carbon atoms such as vinyl, propenyl, butenyl, pentenyl, and hexenyl; alkynyl groups selected from ethynyl, propynyl, butynyl, pentynyl, and hexynyl; aryl groups such as phenyl, tolyl, xylyl, benzyl, α-methylstyryl, and 2-phenylethyl; alternatively, R 2 The group is a vinyl, methyl, ethyl, or phenyl group, for example, the preferred R 2 3SiO 1 / 2 An example of the (M) siloxane unit is MeSiO 1 / 2 , PhMe2SiO 1 / 2 , ViMe2SiO 1 / 2 and Ph2MeSiO 1 / 2Hereinafter, Me represents methyl, Vi represents vinyl, and hereafter, Ph represents phenyl. The silicone resin may alternatively be called silsesquioxane. The silicone resin may be a single silicone resin or a mixture containing two or more different silicone resins, each of which is as described above. Typically, they are ViMe2SiO 1 / 2 It is an MQ resin containing

[0054] Me3SiO 1 / 2 , and / or PhMeSiO 1 / 2 In combination with the base.

[0055] In addition, silicone resins are MQ resins that may contain residual OZ, where Z can represent hydrogen or an alkyl group. The OZ group remains on the Q component after synthesis of the silicone MQ resin and indicates incomplete condensation during the reaction to produce the MQ resin, provided that the OZ content meets the above hydroxyl per mole of Si requirement. The residual OZ is inherent to the process and reaction used to make the MQ resin. The MQ resin may also undergo a subsequent silylation reaction to further minimize the residual OZ.

[0056] The silicone resin (e) is typically supplied in a hydrocarbon or silicone solvent, and solvent-free silicone resins are typically solid, but preferably herein the silicone resin (e) is supplied in a silicone solvent such as a non-functional polydimethylsiloxane or a polydimethylsiloxane containing two or more alkenyl groups per molecule, such as sample component (a) herein.

[0057] For example, any suitable MQ resin can be utilized as component (e). The molar ratio of M siloxane units to Q siloxane units has a value of from 0.5:1 to 1.2:1, alternatively from 0.6:1 to 1.1:1, alternatively from 0.8:1 to 1.1:1, alternatively from 0.9:1 to 1.1:1. In one embodiment, the MQ resin (e) is one in which the M units are SiO 4 / 2siloxane units (i.e., Q units), each of which is bonded to at least one other SiO 4 / 2 The resin comprises a resin portion bonded to a siloxane unit. The molar ratio of M units to Q units is from 0.3:1 to 1.2:1, alternatively from 0.4:1 to 1.1:1, alternatively from 0.5:1 to 1:1, alternatively from 0.6:1 to 0.9:1. Such MQ resins suitable as component (e) may have a number average molecular weight (Mn) of from 2000 to 50,000 g / mol, alternatively from 3,000 to 30,000 g / mol. In one embodiment, the silicone resin may be described, in terms of mole fraction, as an MQ silicone resin having the formula: (R 4 3SiO 1 / 2 ) u (SiO 4 / 2 ) v an MQ silicone resin having In the formula, R 4 C1-C without aliphatic unsaturation 10 It is a hydrocarbon group, u is from 0.3 to 0.6, alternatively from 0.37 to 0.52, v is from 0.4 to 0.7, alternatively from 0.48 to 0.63, and the value of u+v is 1.0.

[0058] Methods for preparing silicone resins are well known in the art. For example, they can be made by treating a resin copolymer produced by a silica hydrosol capping process with an alkyl- and / or alkenyl-containing endblocking agent. This preferably involves reacting silica hydrosol with a hydrolyzable triorganosilane, such as trimethylchlorosilane, a siloxane, such as hexamethyldisiloxane, or a combination thereof, under acidic conditions, followed by the addition of an M(RSiO) containing 0.07 to 0.2 moles of hydroxyl per mole of silicon (Si). 1 / 2 ) units and Q(SiO 4 / 2 and recovering a copolymer having hydroxyl groups. The copolymer may be further reacted with an endblocking agent containing saturated organic groups to achieve less than 0.06 moles of hydroxyl per mole of Si. Suitable endblocking agents include silazanes, siloxanes, silanes, and combinations thereof.

[0059] Component (e) may be present in the composition in an amount of 1 to 60% by weight, alternatively 1 to 40% by weight, and is an MQ resin or a T resin (silsesquioxane), most preferably an MQ resin.

[0060] Components (a), (c), and (e) always consist of a mixture of macromolecular species with different degrees of polymerization and therefore different molecular weights. Different types of average polymer molecular weights exist, which can be measured in different experiments. The two most important are the number-average molecular weight (Mn) and the weight-average molecular weight (Mw). The Mn and Mw of silicone polymers and / or resins can be determined by gel permeation chromatography (GPC) using polystyrene calibration standards. This technique is standard and yields Mw, Mn, and the polydispersity index (PI). The 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 through Mw; the higher the DP, the higher the viscosity. Silicone resins typically have a weight average molecular weight (M) of 2,000 to 50,000 Daltons, alternatively 3,000 to 45,000, alternatively 3,000 to 40,000, alternatively 4,000 to 30,000, alternatively 5,000 to 30,000. w ), the molecular weight of which is determined, for example, by a triple detector system, such as a light scattering detector, a refractive index detector, and / or a viscosity detector, and gel permeation chromatography using polystyrene standards. In one embodiment, component (e) can be introduced into the composition in a mixture with all or a portion of component (a).

[0061] (F) Adhesion promoter The hydrosilylation-curable silicone coating composition used to prepare the coating for the one-piece woven airbag additionally contains an adhesion promoter (f). The adhesion promoter (f) can be any suitable adhesion promoter that is not detrimental to the mechanical properties of the cured coating on the airbag. For example, one or more monoacrylates, diacrylates, or methacrylates. Examples include C acrylates such as hexanediol diacrylate, heptanediol diacrylate, octanediol diacrylate, nonanediol diacrylate, and / or undecanediol diacrylate. 4~20 Diacrylates such as alkanediol diacrylates may be included. Examples of monoacrylates may include alkoxysilanes containing methacryl or acryl groups, such as methacryloxymethyl-trimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-methacryloxypropyl-methyldimethoxysilane, 3-methacryloxypropyl-dimethylmethoxysilane, 3-methacryloxypropyl-triethoxysilane, 3-methacryloxypropyl-methyldiethoxysilane, 3-methacryloxyisobutyl-trimethoxysilane, or similar methacryloxy-substituted alkoxysilanes, and 3-acryloxypropyl-trimethoxysilane, 3-acryloxypropyl-methyldimethoxysilane, 3-acryloxypropyl-dimethyl-methoxysilane, 3-acryloxypropyl-triethoxysilane, or similar acryloxy-substituted alkyl-containing alkoxysilanes.

[0062] Examples of epoxy-containing alkoxysilanes that may be used as adhesion promoters may include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 4-glycidoxybutyltrimethoxysilane, 5,6-epoxyhexyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

[0063] The adhesion promoter (f) may alternatively comprise one or more alkoxysilanes in combination with an organometallic condensation reaction catalyst such as an organotitanium (titanate), organoaluminum (aluminate), or organozirconium (zirconate) compound.

[0064] In such cases, the alkoxysilane may contain a methacryl or acryl group, such as, for example, methacryloxymethyl-trimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-methacryloxypropyl-methyldimethoxysilane, 3-methacryloxypropyl-dimethylmethoxysilane, 3-methacryloxypropyl-triethoxysilane, 3-methacryloxypropyl-methyldiethoxysilane, 3-methacryloxyisobutyl-trimethoxysilane, or similar methacryloxy-substituted alkoxysilanes, 3-acryloxypropyl-trimethoxysilane, 3-acryloxypropyl-methyldimethoxysilane, 3-acryloxypropyl-dimethyl-methoxysilane, 3-acryloxypropyl-triethoxysilane, or similar acryloxy-substituted alkyl-containing alkoxysilanes.

[0065] The organometallic condensation reaction catalysts including organoaluminum, organozirconium or organotitanium compounds that may be used herein may be selected from organometallic catalysts including zirconates, titanates, organoaluminum chelates, zirconium chelates and / or titanium chelates.

[0066] Zirconate and titanate catalysts are represented by the general formula Zr[OR 5 ]4 or Ti[OR 5 ]4, wherein each R 5 R may be the same or different and represent a monovalent, primary, secondary, or tertiary aliphatic hydrocarbon radical, which may be linear or branched, having 1 to 20 carbon atoms, alternatively 1 to 10 carbon atoms. Optionally, the zirconate / titanate may contain partially unsaturated groups. 5Preferred examples of R include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl, and branched secondary alkyl groups such as 2,4-dimethyl-3-pentyl. 5 is the same, preferably, R 5 is an isopropyl group, a branched secondary alkyl group, or a tertiary alkyl group, especially a tertiary butyl group. Specific examples of zirconate compounds include zirconium tetrapropylate, zirconium tetrabutylate, tetraisopropyl zirconate, zirconium(IV) tetraacetylacetonate (sometimes called zirconium AcAc4), zirconium(IV) hexafluoroacetylacetonate, zirconium(IV) trifluoroacetylacetonate, tetrakis(ethyltrifluoroacetylacetonate)zirconium, tetrakis(2,2,6,6-tetramethylheptanethionate)diamine. Examples of suitable zirconium complexes include zirconium, zirconium(IV) dibutoxybis(ethylacetonate), zirconium tributoxyacetylacetate, zirconium butoxyacetylacetonate bisethylacetoacetate, zirconium butoxyacetylacetonate bisethylacetoacetate, diisopropoxybis(2,2,6,6-tetramethyl-heptanethionate)zirconium, or similar zirconium complexes with β-diketones (including their alkyl- and fluorine-substituted forms) used as ligands.

[0067] Specific titanate examples include titanium tetrapropylate and titanium tetrabutylate, tetra-isopropylzirconate, titanium(IV) tetraacetylacetonate (sometimes referred to as titanium AcAc4), titanium(IV) hexafluoroacetylacetonate, titanium(IV) trifluoroacetylacetonate, tetrakis(ethyltrifluoroacetylacetonate)titanium, tetrakis(2,2,6,6-tetramethyl-heptanethionato)titanium, titanium(IV) dibutoxybis(ethylacetonate), titanium tributoxyacetylacetate, titanium butoxyacetylacetonate bisethylacetoacetate, titanium butoxyacetylacetonate bisethylacetoacetate, diisopropoxybis(2,2,6,6-tetramethyl-heptanethionato)titanium, or similar titanium complexes with β-diketones (including their alkyl- and fluorine-substituted forms) used as ligands.

[0068] Suitable aluminum-based condensation catalysts include Al(OC3H7)3, Al(OC3H7)2(C3COCH2COC 12 H 25 ), Al(OC3H7)2(OCOCH3), and Al(OC3H7)2(OCOC 12 H 25 ) may include, but are not limited to, one or more of:

[0069] The organometallic condensation reaction catalyst may be present in the composition in an amount of 0.1 to 5 wt.% of the composition, alternatively 0.1 to 3 wt.%, alternatively 0.1 to 2 wt.% of the composition. When adhesion promoter (f) is the cumulative amount of (f)(i), (ii), and (iii), it may comprise about 0.3 to 6 wt.% of the composition, alternatively 0.3 to 4 wt.% of the composition.

[0070] In one alternative, the adhesion promoter (f) may alternatively be i) one or more alkoxysilanes having an epoxy group in the molecule; ii) a linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxy or alkoxy group per molecule; iii) An adhesion promoter comprising a mixture and / or reaction product of the organometallic condensation reaction catalyst described above may be included.

[0071] In such a case, (f)(i) the 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 (f)(ii) the linear organosilane containing at least one alkenyl group and at least one hydroxy group or alkoxy group per molecule. The polysiloxane oligomer may be, for example, a methylvinylpolysiloxane in which both molecular chain terminals are dimethylhydroxysiloxy units, or a copolymer of methylvinylsiloxane and dimethylsiloxane units in which both molecular chain terminals are dimethylhydroxysiloxy units, and the oligomeric organopolysiloxane may be a mixture of organopolysiloxane molecules, some of which have silanol end groups at both molecular chain terminals and some of which have only one silanol group, such as a dimethylhydroxysiloxy end unit, where the other end unit is, for example, a dimethylmethoxysiloxy unit, a trimethylsiloxy unit, or a dimethylvinylsiloxy unit. Preferably, more than 50% by weight of the oligomeric organopolysiloxane, more preferably 60 to 100%, contains molecules with silanol end groups at both molecular chain terminals.

[0072] 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 to 300 mPa·s, alternatively 0.1 to 200 mPa·s, alternatively 1 to 100 mPa·s, as measured using a Brookfield DV III rotational viscometer at 25°C with a CP-52 spindle at 12 rpm. Component (f)(ii) may be present in the composition in an amount of 0.1 to 5% by weight, alternatively 0.1 to 3% by weight, alternatively 0.1 to 2% by weight of the composition.

[0073] (f)(iii) is the organometallic condensation reaction catalyst as described above in the amount indicated above.

[0074] The adhesion promoter provides strong bonding capabilities between the resulting coating and textile substrates, including woven fabrics.

[0075] Additional Optional Ingredients Additional optional ingredients may be present in the liquid silicone rubber composition depending on its intended end use. Examples of such optional ingredients include cure inhibitors, thermally conductive fillers, pot life extenders, flame retardants, lubricants, pigments and / or colorants, fungicides, wetting agents, heat stabilizers, compression set additives, plasticizers, and mixtures thereof.

[0076] Curing inhibitor When the hydrosilylation-curable silicone coating composition described hereinabove is cured via an addition / hydrosilylation reaction, an inhibitor can be used to inhibit the curing of the composition. These inhibitors are used to retard or inhibit the activity of the catalyst, thereby preventing premature curing during storage and / or extending the working time or pot life of the hydrosilylation-cured composition. Inhibitors for the hydrosilylation catalyst (d), such as platinum metal-based catalysts, are well known in the art and may include hydrazines, triazoles, phosphines, mercaptans, organic nitrogen compounds, acetylene alcohols, silylated acetylene alcohols, maleates such as dibutyl maleate, fumarates, ethylenically or aromatically unsaturated amides, ethylenically unsaturated isocyanates, olefinic siloxanes such as tetramethyltetrazinylcyclotetrasiloxane, unsaturated hydrocarbon monoesters and diesters, conjugated ene-ynes, hydroperoxides, nitriles, and diaziridines. Alkenyl-substituted siloxanes such as those described in US Pat. No. 3,989,667 may also be used, of which cyclic methylvinylsiloxanes are preferred.

[0077] One class of known inhibitors for hydrosilylation catalysts, such as platinum catalysts (d), includes the acetylenic compounds disclosed in U.S. Patent No. 3,445,420. Acetylenic alcohols, such as 2-methyl-3-butyn-2-ol, constitute a preferred class of inhibitors, suppressing the activity of platinum-containing catalysts at 25°C. Typically, compositions containing these inhibitors must be heated to temperatures above 70°C in order to cure at a practical rate.

[0078] Examples of acetylenic alcohols 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-penten-4-yn-3-ol, and mixtures thereof. In one alternative, the inhibitor is selected from one or more of 1-ethynyl-1-cyclohexanol (ETCH), tetramethyltetrazinylcyclotetrasiloxane, 3-methylbutynol, and / or dibutyl maleate.

[0079] When present, in some cases, inhibitor concentrations as low as 1 mole of inhibitor per mole of catalyst (d) metal provide sufficient storage stability and cure speed. In other cases, inhibitor concentrations of up to 500 moles of inhibitor per mole of catalyst (d) metal are required. The optimum concentration for a given inhibitor in a given hydrosilylation-curable silicone coating composition herein is readily determined by routine experimentation. Mixtures of the above may also be used. Depending on the concentration and form in which the selected inhibitor is commercially provided / available, if present in the composition, the inhibitor is typically present in an amount of 0.0001 to 10% by weight, alternatively 0.001 to 5% inhibitor, alternatively 0.0125 to 5% by weight of the composition.

[0080] Pot Life Extender Pot life extenders such as triazoles may be used.

[0081] flame retardants Examples of flame retardants include aluminum trihydrate, chlorinated paraffins, hexabromocyclododecane, triphenyl phosphate, dimethylmethylphosphonate, tris(2,3-dibromopropyl)phosphate (brominated tris), and mixtures or derivatives thereof.

[0082] lubricant 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, flame retardants are typically present in an amount of 0.1 to 5% by weight of the composition.

[0083] Pigments and colorants Examples of pigments include titanium dioxide, chromium oxide, bismuth vanadium oxide, iron oxide, and mixtures thereof.

[0084] Examples of colorants that can be used in the hydrosilylation-curable silicone coating composition include pigments, vat dyes, reactive dyes, acid dyes, chrome dyes, disperse dyes, cationic dyes, and mixtures thereof. The dual moisture-curable organopolysiloxane compositions described herein can further include one or more pigments and / or colorants, which can be added as needed. 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 may be used as long as it is compatible with the compositions herein. In dual moisture-curable organopolysiloxane compositions, pigments and / or colored (non-white) fillers, such as carbon black, may be used in the catalyst package to color the end sealant product.

[0085] Suitable white pigments and / or colorants include titanium dioxide, zinc oxide, lead oxide, zinc sulfide, lithopone, zirconium oxide, and antimony oxide.

[0086] Suitable non-white inorganic pigments and / or colorants include, but are not limited to, goethite, lepidocrocite, hematite, maghemite, and magnetite; iron oxide pigments such as black iron oxide, yellow iron oxide, brown iron oxide, and red iron oxide; blue iron pigments; chromium oxide pigments; cadmium pigments such as cadmium yellow, cadmium red, and cadmium cinnabar; bismuth pigments such as bismuth vanadate and bismuth vanadate molybdate; mixed metal oxide pigments such as cobalt titanate green; chromate and molybdate pigments such as chrome yellow, molybdate red, and molybdate orange; ultramarine pigments; cobalt oxide pigments; nickel antimony titanate; lead chromium; carbon black; lamp black; and metallic effect pigments such as aluminum, copper, copper oxide, bronze, stainless steel, nickel, zinc, and brass.

[0087] 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 condensed pigments, isoindolinone and isoindoline pigments, polycyclic pigments, perylene and perinone pigments, thioindigo pigments, anthrapyrimidone pigments, flavanthrone pigments, anthanthrone pigments, dioxazine pigments, triarylcarbonium pigments, quinophthalone pigments, and diketopyrrolopyrrole pigments.

[0088] Typically, the pigment and / or colorant, when particulate, has an average particle size in the range of 10 nm to 50 μm, preferably in the range of 40 nm to 2 μm. When present, the pigment and / or colorant is present in a range of from 2 wt % of the catalyst package composition, alternatively from 3 wt %, alternatively from 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.

[0089] In a preferred embodiment, when present, the pigment and dye are used in the form of a pigment masterbatch comprised of pigments dispersed in component (a) in a ratio of 25:75 to 70:30.

[0090] heat stabilizer Examples of heat stabilizers include metal compounds such as red iron oxide, yellow iron oxide, ferric hydroxide, cerium oxide, cerium hydroxide, lanthanum oxide, copper phthalocyanine, aluminum hydroxide, fumed titanium dioxide, iron naphthenate, cerium naphthenate, cerium dimethylpolysilanolate, and acetylacetone salts of metals selected from copper, zinc, aluminum, iron, cerium, zirconium, titanium, etc. Other examples of heat stabilizers include suitable antioxidants or metal scavengers such as salicyloylaminotriazole, 1,2-bis(3,5-di-tert-butyl-4-hydroxylhydrocinnamoyl)hydrazine, 2-hydroxy-N-1H-1,2,4-triazol-3-ylbenzamide, and N'1,N'12-bis(2-hydroxybenzoyl)dodecane dihydrazide, if present. The amount of heat stabilizer in the composition may range from 0.01% to 1.0% by weight of the total composition.

[0091] In a preferred embodiment, the composition is free of silica. In a preferred embodiment, the composition is free of calcium carbonate. In a preferred embodiment, the composition is free of silica and calcium carbonate.

[0092] In one embodiment, the hydrosilylation-curable silicone coating composition comprises: a) an organopolysiloxane polymer having a viscosity at 25°C of 100 to 200,000 MPa.s, alternatively 1000 to 150,000 MPa.s, alternatively 1000 mPa.s to 125,000 MPa.s, alternatively 1000 mPa.s to 100,000 MPa.s (measured according to ASTM D1084 Method B using a Brookfield DV III rotational viscometer equipped with a CP-52 spindle most appropriate for the viscosity measured at 1 rpm), and having at least two unsaturated groups per molecule chosen from alkenyl and / or alkynyl groups, 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; b) a filler blend of hydromagnesite and huntite, which may be treated with a suitable hydrophobizing agent, for example a fatty acid or a fatty acid ester such as a stearate; a filler blend which is typically treated to render it hydrophobic and is present in an amount of 5.0 to 40% by weight of the composition, alternatively 7.5 to 35% by weight of the composition, alternatively 7.5 to 30% by weight of the composition; c) an organosilicon compound having at least two, alternatively at least three, Si-H groups per molecule, wherein preferably the molar ratio of silicon-bonded hydrogen atoms in component (c) to the total unsaturated groups selected from alkenyl and / or alkynyl groups in the composition is from 0.5:1 to 20:1, or alternatively the molar ratio of silicon-bonded hydrogen atoms in component (c) to the total unsaturated groups selected from alkenyl and / or alkynyl groups in 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, and the organosilicon compound has at least two, alternatively at least three, Si-H groups per molecule, present in an amount of 0.1 to 20 wt.% of the hydrosilylation-curable silicone coating composition, alternatively 0.1 to 15 wt.% of the hydrosilylation-curable silicone coating composition, alternatively 0.25 to 10 wt.% of the hydrosilylation-curable silicone coating composition, and further alternatively 0.5 to 10 wt.% of the hydrosilylation-curable silicone coating composition. Component (c) functions as a crosslinker. d) a hydrosilylation cure catalyst, wherein the catalytic amount of the hydrosilylation catalyst is from 0.01 ppm to 10,000 parts by weight of platinum group metal per million parts (ppm) based on the weight of the composition, alternatively from 0.01 to 5000 ppm, alternatively from 0.01 to 3,000 ppm, alternatively from 0.01 to 1,000 ppm, alternatively from 0.01 to 750 ppm, alternatively from 0.01 to 500 ppm, alternatively from 0.01 to 100 ppm of metal based on the weight of the composition, wherein the amount of component (d) present ranges from 0.001 to 3.0% by weight of the composition, alternatively from 0.001 to 1.5% by weight of the composition, alternatively from 0.01 to 1.5% by weight, alternatively from 0.01 to 0.1.0% by weight of the hydrosilylation-curable silicone coating composition, depending on the form / concentration in which the catalyst is provided, for example, in a polymer or solvent; e) one or more silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups, or mixtures of alkenyl and alkynyl groups, chosen from T silicone resins (silsesquioxanes), DT silicone resins, MQ silicone resins, MDT silicone resins, MTQ silicone resins, QDT silicone resins, or mixtures thereof, in an amount of 1 to 60% by weight of the composition, alternatively 1 to 40% by weight; f) one or more monoacrylates, diacrylates or methacrylates, epoxy-containing alkoxysilanes, vinyl-containing alkoxysilanes, alkoxysilanes containing methacryl or acrylic groups, and i) one or more alkoxysilanes having an epoxy group in the molecule in an amount of 0.1 to 5% by weight of the composition, alternatively 0.5 to 3% by weight of the composition, alternatively 0.5 to 2% by weight of the composition; ii) a linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxy or alkoxy group per molecule in an amount from 0.1 to 5% by weight of the composition, alternatively from 0.1 to 3% by weight of the composition, alternatively from 0.1 to 2% by weight of the composition; and iii) an adhesion promoter selected from mixtures and / or reaction products of an organometallic condensation reaction catalyst comprising an organotitanium, organoaluminum, or organozirconium compound, or mixtures thereof, in an amount from 0.1 to 5% by weight of the composition, alternatively from 0.1 to 3% by weight, alternatively from 0.1 to 2% by weight of the composition; wherein the adhesion promoter (f) is typically present in the composition in a cumulative amount of (f)(i), (ii), and (iii) of about 0.3-6% by weight of the composition, alternatively 0.3-4% by weight of the composition, and the composition can be any combination of the above ranges, provided that the total weight percent is 100% by weight.

[0093] Typically, when stored prior to use, hydrosilylation-curable silicone coating compositions utilized to coat materials and / or airbags are stored in two parts, Part A and Part B, to keep components (c) (crosslinker) and (d) hydrosilylation cure catalyst separate and avoid premature curing. Typically, the Part A composition includes components (a) polymer, (b) filler blend, and (d) hydrosilylation cure catalyst.

[0094] Part B includes components (a), (b) and (c) the crosslinker, and inhibitor, if present.

[0095] Component (e), one or more silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups, or a mixture of alkenyl and alkynyl groups, e.g., one or more MQ resins, can optionally be present in Part A, Part B, or Parts A and B. When utilizing the reaction product of (f)(i), (f)(ii), and (f)(iii) for the adhesion promoter, component (f)(iii) is typically stored in Part A and components (f)(i) and (ii) in Part B to prevent premature reaction.

[0096] When present, additives in the composition can be present in either Part A or Part B, so long as they do not adversely affect the properties of any other components (e.g., catalyst deactivation). Parts A and B of the hydrosilylation-curable silicone coating compositions described herein are mixed together immediately before use to initiate curing of the overall composition into a silicone elastomeric material. The composition can be designed to be mixed in any suitable weight ratio; for example, 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, with a 1:1 weight ratio being most preferred.

[0097] The components of Part A and / or Part B may be mixed together individually, or may be introduced into the composition in a pre-prepared combination, e.g., to facilitate mixing of the final composition. For example, components (a) and (b) are often mixed together to form an LSR polymer base or masterbatch before being added to the other components. These may then be mixed directly with the other ingredients of the part being manufactured, or may be used to make pre-prepared concentrates, commonly referred to in the industry as masterbatches.

[0098] In this case, to facilitate mixing of the components, one or more masterbatches may be utilized to facilitate mixing of the components to form the Part A and / or Part B compositions.

[0099] Parts A and B of the composition can be prepared by combining all of the respective components at ambient temperature. Any mixing technique and equipment described in the prior art can be used for this purpose. The specific equipment used will depend on the viscosity of the components and the final composition. Suitable mixers include, but are not limited to, paddle-type mixers, such as planetary mixers, and kneader-type mixers. It may be desirable to cool the components during mixing to prevent premature hardening of the composition.

[0100] Prior to use, the respective Part A and Part B components are mixed together in the desired ratio.

[0101] As part of the method herein, the coating composition as described hereinabove can be applied to a textile material or airbag substrate, for example, an one-piece woven (OPW) airbag substrate, or a textile material for a cut-and-sew, seam-shielded (CSSS) airbag, by any suitable known technique, including spraying, gravure coating, bar coating, knife-over-roller coating, knife-over-air coating, padding, dipping, and screen printing.

[0102] The hydrosilylation-curable silicone coating compositions are designed to be used to coat either cut-and-sew, seam-shielded (CSSS) airbag textiles or one-piece woven (OPW) airbags, particularly for use as front and / or front center airbags designed to act as a cushion at the point of impact in a front or rear collision with a vehicle, i.e., a front or rear collision.

[0103] Curing of the hydrosilylation-curable silicone coating composition after application onto the textile is typically carried out by heating the composition at a temperature of 150-200°C for up to 5 minutes, alternatively 30 seconds to 2 minutes.

[0104] Although not preferred, it is possible to apply the composition in multiple layers. Typically, the hydrosilylation-curable silicone coating composition does not require a basecoat between it and the textile material, and further, although it is possible to apply a topcoat over the resulting coating, it is generally considered unnecessary.

[0105] The present disclosure relates to textile materials or airbag substrates, e.g., 10 g / m2, determined according to ISO 3801. 2 ~50g / m 2 , alternatively 15-40g / m 2 , alternatively 15 g / m 2 ~35g / m 2 g / m 2 , alternatively 20 g / m 2 ~35g / m 2 The invention comprises an one-piece woven (OPW) airbag substrate or a cut-and-sew seam shield (CSSS) airbag having thereon a cured coating of a hydrosilylation-curable silicone coating composition having an average dry coating weight of

[0106] Textile materials or airbag substrates, such as one-piece woven (OPW) airbag substrates or cut-and-sew seam shield (CSSS) airbags, can be made from any suitable woven fabric, particularly plain weave fabrics, but can also be knitted or nonwoven fabrics, for example. The fabric can be made from synthetic fibers or blends of natural and synthetic fibers, such as polyamides such as nylon 6, nylon 66, and nylon 46, polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, polyimides, polyethylene, polypropylene, polyester-cotton, polyacrylonitrile fiber fabrics, aramid fiber fabrics, polyetherimide fiber fabrics, polysulfone fiber fabrics, carbon fiber fabrics, rayon fiber fabrics, and / or glass fiber. For applications requiring high strength, such as one-piece woven airbags for automobiles, it is preferable to use polyamide fiber fabrics or polyester fiber fabrics.

[0107] Before coating the liquid curable silicone rubber composition substrate, it is preferably washed with water and dried.

[0108] For use as a monolithic woven airbag textile material, the textile material should be sufficiently flexible so that it can be folded into a relatively small volume, yet also have sufficient strength to withstand high speed deployment, e.g., under the influence of an explosive charge. Polyamide and polyester fibers are particularly preferred for making airbag textiles. However, applying coatings to polyamide and polyester airbags can be difficult, and therefore the need for adhesion promoters such as component (f) in the compositions described above, as the coating compositions described herein above must have good adhesion to plain-woven nylon and polyester textile materials. Therefore, the coating compositions described herein are designed to have particularly good adhesion and film-forming properties immediately upon contact with the textile material, so that film formation on the surface of the coated textile material is uniform. Preferably, they also have a desired average dry coat weight, e.g., 10 g / m, as determined according to ISO 3801, as noted above.2 ~50g / m 2 , alternatively 15-40g / m 2 , alternatively 15 g / m 2 ~35g / m 2 g / m 2 , alternatively 20 g / m 2 ~35g / m 2 Due to its ability to achieve

[0109] It has been found that by using a blend of hydromagnesite and huntite as filler (b) in place of silica reinforcing filler and / or calcium carbonate filler in the coating, surprisingly good results can be obtained in / on textile materials / airbag coatings cured from the hydrosilylation-curable silicone coating composition described herein.Before curing, the composition had good flowability on the substrate surface, allowing for an acceptably thin coating on the substrate after curing, because the blend of hydromagnesite and huntite as filler (b) did not cause the problematic shear thinning effect.However, the cured coating obtained on the textile materials / airbags maintained good mechanical property results after curing, such as modulus at 100% elongation, as well as good flame retardancy and advantageously improved edge comb resistance.

[0110] Therefore, the coating composition using the blend of hydromagnesite and huntite as a filler in the hydrosilylation-curable silicone coating composition described herein can be used as a coating for textile materials, such as for screen printing, as a base coating for silicone leather, as a binder layer coating between textiles and silicone coatings, and particularly for airbags, such as cut-and-sewn, seam-shielded (CSSS) airbags or one-piece woven airbag designs, and both types of airbags, especially those used to cushion vehicle occupants after frontal or rear collisions, rather than side airbags, which tend to require a relatively long inflation period, and also as a coating material used in, for example, aircraft escape chutes.The hydrosilylation-curable silicone coating composition described herein is designed to be coated directly onto the material / airbag, and is generally not used as a topcoat on an intermediate coating applied directly to the fabric / airbag.Furthermore, the coating described herein does not require a topcoat to be applied thereto in order to function. [Example]

[0111] In the following examples, the hydrosilylation-curable silicone coating compositions are defined in weight percent (wt %) unless otherwise specified.

[0112] The vinyl and Si-H group contents were determined by infrared spectroscopy according to ASTM E168 using carbon double bond stretching and silicon-hydrogen bond stretching standards, respectively.

[0113] Viscosity determination Unless otherwise specified, all viscosity measurements given for individual components are measured according to ASTM D1084 Method B using a Brookfield DV III rotational viscometer equipped with the most appropriate spindle CP-52 for the viscosity measured at the particular rpm.

[0114] The compositions of the comparative examples (C.1 to C.6) and the examples (Ex.1 to Ex.6) are disclosed in Tables 1a and 1b, respectively.

[0115] [Table 1]

[0116] In Table 1a: Polymer 1 was a dimethylvinylsiloxy-terminated dimethylsiloxane with a vinyl content of 0.085 wt % and a viscosity of 57,000 mPa.s at 25° C. (ASTM D1084 Method B, Spindle CP-52, 1 rpm).

[0117] Silicone Resin 1 was prepared by mixing 27% by weight of MQ resin (M 37 M Vi 5Q 58 OH8), which has a viscosity of 60,000 mPa.s at 25°C (ASTM D1084 Method B, spindle CP-52, 1 rpm). LSR Base 1 was a combination of 27 wt% fumed silica in Polymer 1.

[0118] The CaCO3 was Hakuenka® CC-R, a fatty acid coated precipitated calcium carbonate available from Shiraishi Calcium Co., Ltd.

[0119] Crosslinker 1 was a trimethyl-terminated dimethyl, methylhydrogen siloxane having a viscosity of approximately 15 mPa.s at 25° C. (ASTM D1084 Method B, Spindle CP-52, 10 rpm).

[0120] The adhesion catalyst is 50 wt. % zirconium(IV) acetylacetonate Zr(AcAc4) in 50 wt. % dimethylvinyl-terminated polydimethylsiloxane having a viscosity of about 9000 mPa.s at 25°C (ASTM D1084 Method B, spindle CP-52, 3 RPM) and a vinyl content of 0.225%.

[0121] [Table 2]

[0122] The compositions of Examples 1-6 are the same as above except for the use of three alternative blends of hydromagnesite and huntite.

[0123] HMH1 was a blend of stearic acid treated hydromagnesite and huntite commercially available as UltraCarb™ 1251 from LKAB Minerals AB of Lulea, Sweden.

[0124] HMH2 was a blend of hydrophobically treated hydromagnesite and huntite commercially available as UltraCarb™ 1253 from LKAB Minerals AB of Lulea, Sweden.

[0125] HMH3 was a blend of stearic acid treated hydromagnesite and huntite commercially available as UltraCarb™ LH3C from LKAB Minerals AB of Lulea, Sweden.

[0126] Sample Preparation Process For these laboratory examples, the compositions were not prepared in two parts because they were used immediately. In commercial situations, they would be prepared in two parts to prevent hardening during storage.

[0127] Polymer 1 and Silicone Resin 1 were first premixed together in all Comparative Examples and Examples, except for C3 (without Polymer 1) and 4, where Silicone Resin 1 and LSR Base were first mixed together in a FlackTek SpeedMixer (Model No. DAC400.2VACLR). The remaining ingredients of each Comparative and Example composition were then added and mixed into the composition using the SpeedMixer.

[0128] The viscosity of the resulting compositions was evaluated at three alternative shear rates using a TA Instruments AR2000 rheometer at 25° C. according to Dow Silicones Corporation Corporate Test Method CTM1094. The results are shown below in Table 2a (Comparative Example) and Table 2b (Example).

[0129] [Table 3]

[0130] [Table 4]

[0131] The compositions herein were found to have consistent viscosity values ​​at different shear rates, indicating that blends of hydromagnesite and huntite do 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.

[0132] The compositions of the examples and comparative examples were then evaluated for their mechanical and coating properties.

[0133] Mechanical property tests were performed using 2 mm thick sheets of the cured product of each example and comparative composition. The sheets were prepared by compression molding and cured at approximately 120°C for 10 minutes. The samples were not post-cured.

[0134] Methods used herein to measure the mechanical properties of silicone rubber The hardness of the silicone rubber samples prepared and cured as described above was measured with a Shore A durometer according to ASTM D2240. The tensile strength, elongation at break, and modulus at 100% elongation were determined according to ASTM D412.

[0135] Tear strength was determined using Die B according to ASTM D624.

[0136] Specific gravity was determined according to ASTM D792.

[0137] The results of the mechanical property tests are shown in Tables 3a and 3b below.

[0138] [Table 5]

[0139] [Table 6]

[0140] It can be seen that the mechanical properties were retained when the blend of hydromagnesite and huntite was used.

[0141] Testing of Coated Fabrics According to European Airbag Standardization Committee (EASC) Instruction No. 99040180 (dated December 11, 2009) Coated textile material samples were prepared and evaluated in accordance with EASC 99040180. Using the compositions of each example and comparative example, coatings were applied onto 470 dtex nylon (PA66) textile material. The compositions were coated onto 470 dtex nylon (PA66) textile material using a Mathis Lab Coater available from Werner Mathis USA Inc., USA. Coating time: 1 minute, 25 gm 2 The coating temperature used was 190° C. for a wet coating weight of 1000 μm. The fabric was coated in the warp direction.

[0142] Tests were then conducted on textile material samples coated with cured coatings made from the compositions of Comparative Examples C1-6 and Examples 1-6, with three samples tested in the warp and weft directions for 3.12 flammability according to ISO 3795, 3.15 edgecomb resistance according to ASTM D6479, and 3.25 flex abrasion according to ISO 5981. The results are shown in Tables 4a and b, 5a and b, and 6a and b, respectively.

[0143] [Table 7]

[0144] [Table 8]

[0145] It can be seen that the use of a blend of hydromagnesite and huntite as a filler in combination with a silicone resin resulted in a significant improvement in flammability.

[0146] [Table 9]

[0147] [Table 10]

[0148] When comparing the Examples with C1, C2, and C3, which do not contain any filler, it is seen that the Examples show a clear improvement in edge-comb resistance. However, when comparing the Examples herein with C4, C5, and C6, which are filled with fumed silica (C4) and calcium carbonate (C5 and C6), it is seen that the Examples maintain similar, if not more significant, edge-comb resistance than C4, C5, and C6.

[0149] [Table 11]

[0150] [Table 12]

[0151] It can be seen that similar flex wear results were obtained by using a blend of hydromagnesite and huntite as a filler in place of silica and / or calcium carbonate.

[0152] Thus, the hydrosilylation-curable silicone coating composition described herein, which contains a silicone resin, such as an MQ resin, and a blend of hydromagnesite and huntite as fillers, exhibits good flowability without shear thinning, and textile materials coated using coatings made from the composition maintain their edge-comb resistance, adhesion, and mechanical strength. Therefore, it can be seen that it can be used to coat cut-and-sewn, seam-shielded (CSSS) airbag textiles or one-piece woven (OPW) airbags, particularly for use as front and / or front center airbags designed to act as cushions at the point of impact in front or rear collisions with a vehicle. As previously indicated, it is also a suitable coating for textile materials, such as for screen printing, as a base coating for silicone leather, and as a binder layer coating between the textile and the silicone coating.

Claims

1. 1. A hydrosilylation-curable silicone coating composition comprising: a) an organopolysiloxane polymer having a viscosity of 100 to 200,000 mPa.s at 25°C and at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl or alkynyl groups; b) a filler blend of hydromagnesite and huntite, which may be treated with a suitable hydrophobizing agent; c) organosilicon compounds having at least two, alternatively at least three, Si—H groups per molecule; d) a hydrosilylation curing catalyst; e) one or more silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups, or mixtures of alkenyl and alkynyl groups, 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) one or more monoacrylates, diacrylates or methacrylates, epoxy-containing alkoxysilanes, vinyl-containing alkoxysilanes, alkoxysilanes containing methacryl groups or alkoxysilanes containing acryl groups, and i) one or more alkoxysilanes having an epoxy group in the molecule; ii) a linear organopolysiloxane oligomer containing at least one alkenyl group and at least one hydroxy or alkoxy group per molecule; and iii) an organometallic condensation reaction catalyst comprising an organotitanium compound, an organoaluminum compound, or an organozirconium compound, or a mixture thereof; and

2. 2. The hydrosilylation-curable silicone coating composition of claim 1, wherein component (e) is an MQ resin containing one or more unsaturated groups selected from alkenyl groups, alkynyl groups, or mixtures of alkenyl and alkynyl groups, and / or a T resin containing unsaturated groups selected from alkenyl groups, alkynyl groups, or mixtures of alkenyl and alkynyl groups.

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

4. The hydrosilylation-curable silicone coating composition of any one of claims 1 to 3, wherein component (e) is provided in admixture with some or all of component (a).

5. 5. The hydrosilylation-curable silicone coating composition of any one of claims 1 to 4, wherein the filler blend of component (b) hydromagnesite and huntite has been hydrophobized and / or is present in the composition in an amount of from 5.0% to 40% by weight of the composition.

6. A textile material or airbag at least partially coated with a silicone coating that is the cured elastomeric product of the hydrosilylation-curable silicone coating composition of any one of claims 1 to 5.

7. Average coating dry weight, determined according to ISO 3801, of 10 g / m ２ ~50g / m ２ 7. The textile material or airbag according to claim 6, wherein:

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

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

10. 10. A method for coating textile materials or airbags by mixing the components of the hydrosilylation-curable silicone coating composition of claims 1 to 5, comprising: coating the textile material or airbag with the composition; and curing the hydrosilylation-curable silicone coating composition by heating the composition at a temperature of 150-200°C for up to 5 minutes.

11. A coated textile material or a coated airbag obtained or obtainable by coating a textile material or an airbag according to claim 10.

12. Average coating dry weight, determined according to ISO 3801, of 10 g / m ２ ~50g / m ２ 12. The coated textile material or coated airbag of claim 11, wherein:

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

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

15. 6. Use of the hydrosilylation-curable silicone coating composition according to any one of claims 1 to 5 in the manufacture of cut-and-sew, seam-sealed or integrally woven airbags or coated textile materials.

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