Silicone coatings for textiles and fabrics

Abstract

The present disclosure relates to a hydrosilylation curable silicone rubber coating composition for treating textiles and fabrics, the hydrosilylation curable silicone rubber coating composition comprising an adhesion promoter, the adhesion promoter comprising a silicone bisphenol adduct compound, the silicone bisphenol adduct compound comprises a biphenyl unit that is not directly attached to a silicon atom, and at least one Si-H group. The present disclosure also extends to textiles and fabrics, such as inflatable safety restraint devices, such as airbags, coated with a cured product of the hydrosilylation curable silicone rubber coating composition; and extends to methods of coating the textiles and fabrics, such as inflatable safety restraint devices, such as airbags, with a hydrosilylation curable silicone rubber coating composition. The hydrosilylation-curable silicone rubber coating composition has excellent flowability on the surface of a textile, and a textile coated with a cured product of the hydrosilylation-curable silicone rubber coating composition described herein is considered to have excellent adhesion to the textile and fabric as compared to a standard coating material for treating the textile and fabric. The adhesive force to woven fabrics is improved, and the total volatile organic compounds (TVOC) are low.

Description

[0001] This disclosure relates to a hydrosilane-curable silicone rubber coating composition for treating textiles and fabrics; to textiles and fabrics, such as inflatable safety restraint devices, such as airbags, coated with a cured product of a hydrosilane-curable silicone rubber coating composition; and to a method of coating said textiles and fabrics (such as inflatable safety restraint devices, such as airbags) with a hydrosilane-curable silicone rubber coating composition. Hydrosilane-curable silicone rubber coating compositions exhibit excellent flowability on textile surfaces, and textiles coated with a cured product of the hydrosilane-curable silicone rubber coating composition described herein (such as inflatable safety restraint devices, such as airbags) are considered to have improved adhesion to woven fabrics and lower total volatile organic compound (TVOC) content compared to standard coating materials used for treating said textiles and fabrics.

[0002] Textiles and fabrics are typically treated with one or more coatings to impart a variety of properties. Silicone coating compositions are used to provide textiles and / or fabrics with a wide range of different properties. One of the main applications of treated textiles and fabrics is for use in or as inflatable safety restraint devices, particularly airbags.

[0003] Airbags are widely used to cushion and protect occupants during vehicle collisions and accidents.

[0004] They are designed to protect drivers and passengers from injury between the initial impact and subsequent collisions during a traffic accident by inflating within 0.02 to 0.12 seconds after the initial impact. Inflatable safety restraint devices, such as airbags, typically consist of textiles or fabric bags (sometimes called cushioning bags), sensors, and an inflator. In the event of an accident, sensors within the vehicle detect abnormal deceleration and trigger the inflator, allowing the airbag to inflate instantly and effectively. Expanding gas is delivered through conduits and inflates the airbag, cushioning the vehicle occupants (driver or passenger) and protecting them from any further impact injuries inside the vehicle (e.g., a car).

[0005] Airbags and / or airbag fabrics can be made of woven or knitted fabrics of synthetic fibers, such as thermoplastics (e.g., polyamides, such as nylon-6,6) or polyesters (e.g., polyethylene terephthalate (PET), and benefit from the application of silicone coatings in several ways, including:

[0006] 1) Improved thermal protection against high-temperature gases and particulate matter (600°C to 1,000°C) generated during airbag deployment using a pyrotechnic generator;

[0007] 2) Improved flame retardancy of the fabric;

[0008] 3) Enhanced resistance to airbag leakage;

[0009] 4) Improved stress resistance during airbag deployment; and

[0010] 5) The silicone coating is soft and lightweight, giving the airbag excellent flexibility, allowing it to be folded into a more compact module.

[0011] They can be made from flat fabric sheets that are coated and sewn together to provide sufficient mechanical strength; or they can be woven together as one piece with seams of integral weaving (often referred to as "one-piece weaving" or OPW).

[0012] Stitched flat fabric airbags are typically assembled with a coated fabric surface inside the airbag. One-piece woven airbags are coated on the outside of the airbag and are able to maintain air pressure better after deployment, so they tend to be used in airbags designed to retain inflation for a longer period of time after a collision, such as side curtain airbags.

[0013] Today, vehicles typically require several airbags as a means of protecting occupants in the event of a collision. These include front airbags, front center airbags, side airbags, side curtain airbags, chest airbags, and / or knee airbags. Airbags are usually concealed within vehicle trim to remain invisible during normal vehicle operation.

[0014] For example, front airbags can be installed in the steering wheel on the driver's side and in the dashboard on the passenger's side. They are designed to act as cushions at the point of impact, especially in collisions with the front or rear of the vehicle. They exhibit relatively high permeability to allow the inflated airbag to deflate rapidly after the initial impact.

[0015] Typically, these airbags are flat pieces of fabric sewn together.

[0016] Side curtain airbags are becoming increasingly common. They are most often installed within the headliner above the doors and windows, deploying along the side windows from near the roof to protect vehicle occupants from side impacts and subsequent rollovers (i.e., vehicles rolling over, upside down, or rolling more than once). For this reason, side curtain airbags are designed to maintain their inflation for extended periods (e.g., retaining at least 50% of their initial pressure 5 seconds after high-pressure inflation). This means they need to maintain a large amount of gas and high pressure throughout a potentially prolonged rollover. They typically deploy from packaging containers stored in the roof along the side windows (therefore, only the back and front deploy). Therefore, side curtain airbags not only provide cushioning but also protection against shattered glass and other debris.

[0017] One-piece fabric-style airbags are often combined with silicone sealant coatings for side curtain airbags to provide the low permeability required for side curtain airbags (thus extending gas escape time).

[0018] The silicone coating used on airbags is designed not only to prevent air leakage but also to maintain the airbag's flexibility and make it resistant to temperature fluctuations, aging, and wear. These silicone coatings need to possess these properties because, for example, airbags may remain unused for extended periods before deployment is triggered in a collision. This requires the silicone coating to be highly stable over time to prevent the airbag from jamming and to ensure smooth deployment even after many years. Furthermore, to maintain functionality throughout the entire lifespan of the vehicle in which the airbags are stored, the silicone coating needs to bond firmly to the textiles / fabrics used in manufacturing the airbags.

[0019] Therefore, silicone rubber coating compositions capable of hydrogenation and silanization curing for treating textiles and fabrics typically contain adhesion promoters to enhance the adhesion between the coating and the textile / fabric to which it is applied. A wide variety of such adhesion promoters have been proposed, many of which contain combinations of alkoxysilanes (such as vinyltrialkoxysilanes, etc.).

[0020] 3-Methacryloxypropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane) with organometallic catalysts (such as tetrabutyl titanate (Ti(O(CH2)3CH3)4), tetraisopropyl titanate (Ti(OCH(CH3)2)4)) or zirconium acetylacetonate (Zr(acac)4) or (Zr(CH3C(=O)CH-C(O)) -(a combination of CH3)4). However, while these adhesion promoter systems produce good adhesion between the coating and the textile and / or fabric substrate, they also generate volatile organic compounds (VOCs), such as methanol and volatile siloxanes, during the curing process through interactions between the adhesion promoter catalyst, silanes, and other components of the composition (e.g., siloxane polymers, oligomers, and / or resins). The fact that the adhesion promoter catalyst remains active in the resulting cured coating can lead to the generation of additional VOCs after curing. The resulting VOCs are subsequently emitted as gases during and after the curing process. VOC emissions are a significant issue in the automotive industry, as hundreds of polymer materials and components are used, a large proportion of which contain high levels of VOCs, requiring identification and control before application.

[0021] Automakers and original equipment manufacturers (OEMs) supplying the automotive industry are continuously seeking low-VOC emission materials for automotive interiors to reduce total volatile organic compound (TVOC) emissions and meet the requirements of the automotive industry and OEMs. Both parties have been pushing for the use of low-emission materials in automotive interiors with carbon emissions below (<) 50 μg C / g of sample (measured by GC-FID according to industry testing requirements, such as the German Association of the Automotive Industry (VDA) test method VDA277 for volatile organic compounds). The result of this measurement is called "carbon emissions," and μg C / g represents the amount of micrograms of carbon per gram of sample.

[0022] While low TVOCs can be achieved by curing coated airbags with heat (e.g., heating at 200°C for several hours, such as 4 hours), this process inevitably leads to higher energy consumption and manufacturing costs. Therefore, the industry needs to find a silicone rubber coating composition capable of hydrogenated silanization curing for treating textiles and fabrics (especially airbags). This coating composition, stored in automotive interiors before use, releases low VOC emissions both before and during curing, as well as the resulting cured coating on the textiles, to reduce TVOC emissions in automotive interiors.

[0023] This article provides a silicone rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics, the coating composition comprising:

[0024] a) An organopolysiloxane polymer having a viscosity at 25°C between 100 mPa·s and 200,000 mPa·s, including the end values, and having at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl or alkynyl groups;

[0025] b) Optional reinforcing filler comprising pyrolytic silica, precipitated silica, or a mixture thereof;

[0026] c) An organosilicon compound having at least two, alternatively at least three Si-H groups per molecule and not containing biphenyl units;

[0027] d) Hydrogenated silane curing catalyst;

[0028] e) An adhesion promoter comprising an organosilicon bisphenol adduct compound containing a biphenyl unit not directly bonded to a silicon atom, and at least one Si-H group, and optionally...

[0029] f) One or more substantially nonfunctionalized silicone resins selected from T silicone resins (sesquioxanes), DT silicone resins, MQ silicone resins, MDT silicone resins, MTQ silicone resins, QDT silicone resins, or mixtures thereof.

[0030] This document also provides a coated textile material comprising a textile material coated with a cured product of a silicone rubber coating composition capable of hydrogenation and silanization curing, the coating composition comprising:

[0031] a) An organopolysiloxane polymer having a viscosity at 25°C between 100 mPa·s and 200,000 mPa·s, including the end values, and having at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl or alkynyl groups;

[0032] b) Optional reinforcing filler comprising pyrolytic silica, precipitated silica, or a mixture thereof;

[0033] c) An organosilicon compound having at least two, alternatively at least three Si-H groups per molecule and not containing biphenyl units;

[0034] d) Hydrogenated silane curing catalyst;

[0035] e) An adhesion promoter comprising an organosilicon bisphenol adduct compound containing a biphenyl unit not directly bonded to a silicon atom, and at least one Si-H group, and optionally...

[0036] f) One or more substantially nonfunctionalized silicone resins selected from T silicone resins (sesquioxanes), DT silicone resins, MQ silicone resins, MDT silicone resins, MTQ silicone resins, QDT silicone resins, or mixtures thereof.

[0037] This article provides a method for coating textile materials with a silicone rubber coating composition capable of hydrogenation and silanization curing, the method comprising the following steps: mixing the following components of the silicone rubber coating composition capable of hydrogenation and silanization curing:

[0038] a) An organopolysiloxane polymer having a viscosity at 25°C between 100 mPa·s and 200,000 mPa·s, including the end values, and having at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl or alkynyl groups;

[0039] b) Optional reinforcing filler comprising pyrolytic silica, precipitated silica, or a mixture thereof;

[0040] c) An organosilicon compound having at least two, alternatively at least three Si-H groups per molecule and not containing biphenyl units;

[0041] d) Hydrogenated silane curing catalyst;

[0042] e) An adhesion promoter comprising an organosilicon bisphenol adduct compound containing a biphenyl unit not directly bonded to a silicon atom, and at least one Si-H group; and optionally...

[0043] f) One or more substantially nonfunctionalized silicone resins selected from T silicone resins (silsesquioxanes), DT silicone resins, MQ silicone resins, MDT silicone resins, MTQ silicone resins, QDT silicone resins, or mixtures thereof.

[0044] An organosilicon rubber coating composition capable of hydrogenation and silanization curing is applied to the surface of a textile, and the composition is cured to form a coated textile material.

[0045] Also provided is the use of an organosilicon bisphenol adduct compound as an adhesion promoter in a hydrosilanized silanized curable organosilicon rubber coating composition for treating textiles and fabrics, the organosilicon bisphenol adduct compound comprising a biphenyl unit not directly bonded to a silicon atom, and at least one Si-H group; the coating composition further comprises:

[0046] a) An organopolysiloxane polymer having a viscosity at 25°C between 100 mPa·s and 200,000 mPa·s, including the end values, and having at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl or alkynyl groups;

[0047] b) Optional reinforcing filler comprising pyrolytic silica, precipitated silica, or a mixture thereof;

[0048] c) An organosilicon compound having at least two, alternatively at least three Si-H groups per molecule and not containing biphenyl units;

[0049] d) Hydrogenated silanization curing catalyst; and optionally

[0050] f) One or more substantially nonfunctionalized silicone resins selected from T silicone resins (sesquioxanes), DT silicone resins, MQ silicone resins, MDT silicone resins, MTQ silicone resins, QDT silicone resins, or mixtures thereof.

[0051] The composition described herein, containing component (e) as an adhesion promoter, exhibits superior flowability, mechanical strength, improved adhesion to woven fabrics, and lower total volatile organic compound (TVOC) content compared to conventional airbag coating LSR materials that use a combination of organometallic catalysts and alkoxysilanes as adhesion promoters.

[0052] To avoid ambiguity and for the purposes of this disclosure, the biphenyl unit as described herein is intended to represent the presence of the following structure in an adhesion promoter:

[0053] It can be said that the biphenyl unit forms the main chain of this compound. At least one H on one or both aromatic rings can be replaced by another group, and -X 2 - is a methylene bridge, selected from

[0054] -C(CH3)2-, -C(Ph)(CH3)-, -C(Ph)2, -C(CF3)2-, -C(CH3)(C2H5)-, -C(CH2)5-, -C(CH3)(H)-, or -C(H)2-, where Ph is a phenyl group.

[0055] Component (a)

[0056] Component (a) of a silicone rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics is one or more organopolysiloxane polymers having a viscosity at 25°C between 100 mPa·s and 200,000 mPa·s, including end values, and having at least two unsaturated groups per molecule selected from alkenyl or alkynyl groups. Each organopolysiloxane polymer of component (a) comprises a plurality of silanoxy units having formula (I):

[0057] The subscript "a" can be 0, 1, 2 or 3.

[0058] When R' is as described above (or alternatively an alkyl group, usually a methyl group), the silanoxy unit can be described using 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 the silanoxy unit where a=1, i.e., R'1SiO 3 / 2 The Q unit corresponds to the silanoxy unit where a=0, i.e., SiO2. 4 / 2 The organopolysiloxane polymer of component (a) is essentially linear, but may contain a certain proportion of branches due to the presence of T units within the molecule (as previously described), so the average value of a in structure (I) is about 2.

[0059] The unsaturated group of component (a) may be located at the end or side chain of the organopolysiloxane polymer, or at both positions. The unsaturated group of component (a) may be an alkenyl group or an alkynyl group as described above. When present, each alkenyl group may 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 may be, but is not limited to, the following: vinyl, allyl, methyl allyl, propenyl, hexenyl, and cyclohexenyl groups. When present, each alkynyl group may 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 may be, but are not limited to, the following: ethynyl, propynyl, and butynyl groups. Preferred examples of unsaturated groups in component (a) include vinyl, propenyl, isopropenyl, butenyl, allyl, and 5-hexenyl.

[0060] In formula (I), in addition to the unsaturated groups described above, each R' is independently selected from an aliphatic hydrocarbon group, a substituted aliphatic hydrocarbon group, an aromatic group, or a substituted aromatic group. Each aliphatic hydrocarbon group may be exemplified, but is not limited to, an alkyl group having 1 to 20 carbon atoms, alternatively 1 to 15 carbon atoms, alternatively 1 to 12 carbon atoms, alternatively 1 to 10 carbon atoms, alternatively 1 to 6 carbon atoms, or a cycloalkyl group, such as cyclohexyl. Specific examples of alkyl groups may 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.

[0061] Aliphatic nonhalogenated organic groups are exemplified by, but not limited to, the following: alkyl groups having substituted groups, such as suitable nitrogen-containing groups, such as amide groups, imino groups; oxygen-containing groups (such as polyoxyethylene groups, carbonyl groups, alkoxy groups, and hydroxyl groups). Other organic groups may 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.

[0062] For example, component (a) may be selected from polydimethylsiloxane, alkylmethylpolysiloxane, alkylarylpolysiloxane or copolymers thereof (wherein alkyl means any suitable alkyl group, alternatively having two or more carbon atoms), provided that the viscosity of each organopolysiloxane polymer (a) at 25°C is between 100 mPa·s and 200,000 mPa·s, including the end values.

[0063] Therefore, for example, component (a) could be:

[0064] Dialkylene-terminated polydimethylsiloxanes, such as dimethylvinyl-terminated polydimethylsiloxanes; dialkylene-terminated dimethylmethylphenylsiloxanes, such as dimethylvinyl-terminated dimethylmethylphenylsiloxanes; trialkyl-terminated dimethylmethylvinyl polysiloxanes; dialkylvinyl-terminated dimethylmethylvinyl polysiloxane copolymers; dialkylvinyl-terminated methylphenyl polysiloxanes, dialkylene-terminated methylvinylmethylphenylsiloxanes; dialkylene-terminated methylvinyldiphenylsiloxanes; dialkylene-terminated methylvinylmethylphenyldimethylsiloxanes; trimethyl-terminated methylvinylmethylphenylsiloxanes; trimethyl-terminated methylvinylmethylphenylsiloxanes; or trimethyl-terminated methylvinylmethylphenyldimethylsiloxanes.

[0065] In each case of component (a), the viscosity of the organopolysiloxane polymer (a) at 25°C should be between 100 mPa·s and 200,000 mPa·s, including the extreme values; alternatively, from 1,000 mPa·s to 150,000 mPa·s; alternatively, from 1,000 mPa·s to 125,000 mPa·s; alternatively, from 1,000 mPa·s to 100,000 mPa·s.

[0066] Unless otherwise specified, all viscosities are based on ASTM D 4287, measured using a Brookfield cone / plate viscometer with a CP-52 rotor at 1 rpm.

[0067] Typically, for each organopolysiloxane polymer containing at least two silicon-bonded alkenyl groups per molecule of component (a), the alkenyl and / or alkynyl content (e.g., vinyl content) of the polymer is from 0.01 wt% to 3 wt%, alternatively from 0.01 wt% to 2.5 wt%, alternatively from 0.001 wt% to 2.0 wt% of component (a); alternatively, for each of the aforementioned organopolysiloxane polymers containing at least two unsaturated groups selected from alkenyl or alkynyl groups per molecule of component (a), the alkenyl and / or alkynyl content of the polymer is from 0.01 wt% to 1.5 wt%. The alkenyl / alkynyl content of component (a) is determined using quantitative infrared analysis according to ASTM E168.

[0068] The amount of component (a) in the hydrogen-silanized curable silicone rubber coating composition may be from 40% to about 80% by weight of the hydrogen-silanized curable silicone rubber coating composition, alternatively from 45% to 80% by weight of the composition, or alternatively from 50% to 80% by weight of the hydrogen-silanized curable silicone rubber coating composition. Typically, component (a) is present in the amount of 100% by weight minus the cumulative weight percentage of the other components / ingredients in the composition.

[0069] Component (b) (optional)

[0070] Component (b) of the organosilicon coating composition capable of hydrogenation and silanization curing is optionally a reinforcing filler comprising pyrolytic silica, precipitated silica, or a mixture thereof. Finely granulated silica is preferred. A relatively high surface area, typically at least 50 m², is used. 2 / g (according to the BET method of ISO 9277:2010) of reinforced filler (b), such as silica filler. For example, a surface area of ​​50m² is typically used. 2 / g to 450m 2 / g, 50m alternative location 2 / g to 400m 2 / g, 50m alternative location 2 / g to 300m 2 / g, 100m of alternative location 2 / g to 300m 2 / g (BET method according to ISO 9277: 2010) of filler (e.g., pyrolytic silica).

[0071] Typically, the reinforcing filler (b) is a natural hydrophilic (e.g., untreated) silica filler, and is therefore treated with a treatment agent to make it hydrophobic. These surface-modified reinforcing fillers (b) do not clump and can be uniformly incorporated into the organopolysiloxane polymer (a) described below because the surface treatment makes the filler readily wettable by the organopolysiloxane polymer (a).

[0072] Typically, optional reinforcing fillers (b) can be surface-treated with any low molecular weight organosilicon compound disclosed in the art suitable for preventing wrinkling of organosiloxane compositions during processing. For example, organosilanes, polydiorganosiloxanes, or organosilazanes (e.g., hexaalkyldisilazane), short-chain siloxane diols, or fatty acids or fatty acid esters (such as stearates) can be used to impart hydrophobicity to the filler, thus making it easier to handle and obtain homogeneous mixtures with other components. Specific examples include, but are not limited to, silanol-terminated trifluoropropylmethylsiloxanes, silanol-terminated vinylmethylsiloxanes, tetramethyldisilazane, tetramethyldivinyldisilazane, hexamethyldisilazane (HMDZ), silanol-terminated MePh siloxanes, liquid hydroxyl-terminated polydiorganosiloxanes, hexaorganodisilazanes, and hexaorganodisilazanes containing an average of 2 to 20 diorganosiloxane repeating units per molecule. A small amount of water can be added together with the silica treatment agent as a processing aid.

[0073] Optional reinforcing silica filler (b) may be pretreated prior to introduction into a silicone coating composition capable of hydrogenation-silanization curing, or may be treated in situ (i.e., by blending these components together at room temperature or higher until the filler is fully treated, in the presence of at least a portion of the other components of the silicone coating composition capable of hydrogenation-silanization curing described herein). Typically, when present, untreated reinforcing filler (b) is treated in situ with a treatment agent in the presence of an organopolysiloxane polymer (a) to prepare a silicone rubber base material, which may then be blended with other components.

[0074] When present, the optional reinforcing filler (b) is present in the silicone rubber coating composition capable of hydrogenation and silanization curing in an amount of 1.0% to 50% by weight of the composition, alternatively 1% to 30% by weight of the composition, or alternatively 5.0% to 25% by weight of the composition.

[0075] Component (c)

[0076] Component (c) of the organosilicon rubber coating composition capable of hydrogenation-silanization curing acts as a crosslinking agent and is provided in the form of an organosilicon compound having an average of at least two, alternatively at least three, Si-H groups per molecule. Component (c) differs from component (e) because it does not contain any biphenyl units. Component (c) is typically linear, branched, or an organosilicon resin. 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, thereby curing the composition. Alternatively, some or all of component (c) may have two silicon-bonded hydrogen atoms per molecule. However, when, for example, polymer (a) has more than two unsaturated groups per molecule, such a molecule is used only as the sole crosslinking agent, in which case a network can be formed during curing. Otherwise, when component (c) partially comprises molecules having an average of two silicon-bonded hydrogen atoms per molecule, said molecules can act as chain extenders.

[0077] The molecular configuration of organosilicon compounds (c) having at least two, or alternatively at least three, Si-H groups per molecule is not particularly limited. They can be silanes, or straight-chain, branched (a straight-chain with a certain degree of branching due to the presence of T units), or cyclic polymers, or based on organosilicon resins.

[0078] While there are no particular restrictions on the molecular weight of component (c), its viscosity can be measured based on ASTM D 4287 using a Brookfield cone / plate viscometer with a CP-52 rotor at 12 rpm. However, for very low viscosities, they can be measured according to ASTM D-445 using a glass capillary viscometer.

[0079] The silicon-bonded organic group used in component (c) may 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 carbon atoms, especially methyl, ethyl, or propyl groups, or phenyl groups. Preferably, the silicon-bonded organic group used in component (c) is an alkyl group, alternatively methyl, ethyl, or propyl.

[0080] Examples of organosilicon compounds (c) having at least two, alternatively at least three Si-H groups per molecule include, but are not limited to:

[0081] (a) Trimethylsiloxy-terminated methylhydropolysiloxane

[0082] (b) Trimethylsiloxy-terminated polydimethylsiloxane-methylhydrosiloxane

[0083] (c) Dimethylsiloxane-methylhydrosiloxane copolymers with dimethylhydrosiloxane end-capped methylhydrosiloxane.

[0084] (d) Dimethylsiloxane-methylhydrosiloxane cyclic copolymer

[0085] (e) From (CH3)2HSiO 1 / 2 Unit, (CH3)3SiO 1 / 2 unit and SiO 4 / 2 copolymers and / or silicone resins composed of units,

[0086] (f) From (CH3)2HSiO 1 / 2 unit and SiO 4 / 2 copolymers and / or silicone resins composed of units,

[0087] (g) Methylhydrosiloxane cyclic homopolymers having 3 to 10 silicon atoms per molecule;

[0088] Alternatively, component (c) crosslinking agent may be a filler, such as silica treated with one of the aforementioned substances, and mixtures thereof.

[0089] In one embodiment, component (c) is selected from methylhydrosiloxanes capped at both ends with trimethylsiloxy groups; copolymers of methylhydrosiloxanes and dimethylsiloxanes capped at both ends with trimethylsiloxy groups; dimethylsiloxanes capped at both ends with dimethylhydrosiloxy groups; and copolymers of methylhydrosiloxanes and dimethylsiloxanes capped at both ends with dimethylhydrosiloxy groups.

[0090] The crosslinking agent (c) is typically present in the silicone coating composition capable of hydrogen silanization curing in such an amount 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. When this ratio is less than 0.5:1, a sufficiently cured composition cannot be obtained. When this ratio exceeds 20:1, the cured silicone rubber coating composition capable of hydrogen silanization curing tends to increase in hardness upon heating.

[0091] 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 as high as 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.

[0092] The silicon-bonded hydrogen (Si-H) content of component (c) was determined using quantitative infrared analysis according to ASTM E168. In this case, the ratio of silicon-bonded hydrogen to alkenyl (vinyl) and / or alkynyl groups is important when relying on a hydrogen silanization curing process. Generally, this is determined by calculating the total weight % of alkenyl groups (e.g., vinyl [V]) and the total weight % of silicon-bonded hydrogen [H] in the silicone rubber coating composition capable of hydrogen silanization curing, and given that the molecular weight of hydrogen is 1 and the molecular weight of vinyl is 27, the molar ratio of silicon-bonded hydrogen to vinyl is 27 [H] / [V].

[0093] Typically, depending on the number of unsaturated groups in component (a) and the remainder of the silicone rubber coating composition capable of hydrogenation silanization curing, and the number of Si-H groups in component (c), the amount of component (c) in the silicone coating composition capable of hydrogenation silanization curing can be from 0.1% by weight to 10% by weight, alternatively from 0.1% by weight to 7.5% by weight, alternatively from 0.25% by weight to 7.5% by weight, further alternatively from 0.25% by weight to 5% by weight, and alternatively from 0.25% by weight to 5% by weight.

[0094] (d) Hydrogenation silanization catalyst

[0095] Component (d) of the hydrosilylation-curable silicone coating composition is a hydrosilylation catalyst comprising a platinum group metal or a compound thereof, or 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 these metals. Alternatively, platinum and rhodium compounds are preferred due to their high activity levels in the hydrosilylation reaction, with platinum compounds being the most preferred. In the hydrosilylation (or addition) reaction, the hydrosilylation catalyst, such as component (d) of this document, catalyzes the reaction between unsaturated groups (typically alkenyl groups, e.g., vinyl groups) and Si-H groups.

[0096] The hydrosilylation catalyst of component (d) can be a platinum group metal, a platinum group metal deposited on a support (such as activated carbon, metal oxides such as alumina or silica, silica gel or charcoal powder), or a compound or complex of a platinum group metal.

[0097] Platinum is preferably a platinum group metal.

[0098] Examples of preferred hydrosilylation catalysts for component (d) include platinum-based catalysts such as platinum black, platinum oxide (Adams catalyst), platinum on various solid supports, chloroplatinic acid (e.g., hexachloroplatinic acid (platinum oxidation state IV) (Speyer catalyst)), solutions of chloroplatinic acid in alcohols (e.g., isooctyl alcohol or pentanol) (Ramoro catalyst), and complexes of chloroplatinic acid with olefinically unsaturated compounds (such as alkenes and organosiloxanes containing olefinically unsaturated silicon-bonded hydrocarbon groups), such as tetravinyltetramethylcyclotetrasiloxane-platinum complex (Ashby catalyst). Soluble platinum compounds that can be used include, for example, platinum-olefin complexes having the formula (PtCl2.(olefin)2) and H (PtCl3.olefin), in which case olefins having 2 to 8 carbon atoms, such as isomers of ethylene, propylene, butene, and octene, or cycloalkanes having 5 to 7 carbon atoms, such as cyclopentene, cyclohexene, and cycloheptene, are preferred. Other soluble platinum catalysts are, for example, platinum-cyclopropane complexes having 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 vinylsiloxanes (such as methylvinylcyclotetrasiloxane) in an ethanol solution in the presence of sodium bicarbonate. Platinum catalysts having phosphorus, sulfur, and amine ligands, such as (Ph3P)2PtCl2, and platinum-vinylsiloxane complexes, such as symmetrical divinyltetramethyldisiloxane (Castel catalyst), can also be used. Therefore, specific examples of suitable platinum-based catalysts for component (d) include...

[0099] (i) A complex of chloroplatinic acid as described in US 3,419,593 with an organosiloxane containing an olefinic unsaturated hydrocarbon group.

[0100] (ii) Chloroplatinic acid in hexahydrate or anhydrous form;

[0101] (iii) A platinum-containing catalyst, which is obtained by a method comprising the steps of reacting chloroplatinic acid with an aliphatic unsaturated organosilicon compound (such as divinyltetramethyldisiloxane);

[0102] (iv) An olefin-platinum-silyl complex as described in U.S. Patent No. 6,605,734, such as (COD)Pt(SiMeCl2)2, wherein “COD” is 1,5-cyclooctadiene; and / or

[0103] (v) A Castells catalyst, a platinum-divinyltetramethyldisiloxane complex, typically containing about 1% by weight of platinum in a vinylsiloxane polymer. Solvents such as toluene and similar organic solvents have historically been used as alternatives, but the use of vinylsiloxane polymers is currently the preferred choice. These are described in US3,715,334 and US3,814,730. In a preferred embodiment, component (d) may be selected from platinum coordination compounds. In one embodiment, hexachloroplatinic acid and its conversion products with vinylsiloxanes, the Castells catalyst, and the Spier catalyst are preferred.

[0104] The catalytic amount of the hydrogenation silylation catalyst is based on the weight of the silicone rubber coating composition capable of hydrogenation silylation curing, and is typically between 0.01 ppm (parts per million) and 10,000 parts by weight of platinum group metals; alternatively between 0.1 ppm and 7,500 ppm; alternatively between 100 ppm and 75,000 ppm; and alternatively between 500 ppm and 6,000 ppm. This range may refer only to the metal content within the catalyst or to the entire catalyst (including its ligands) as detailed, but typically these ranges refer only to the metal content within the catalyst. The catalyst may be added as a single substance or as a mixture of two or more different substances. Typically, depending on the form / concentration provided by the catalyst (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 silicone rubber coating composition capable of hydrogenation and silanization curing, alternatively 0.001 wt% to 1.5 wt% of the composition, alternatively 0.01 wt% to 1.5 wt% of the silicone coating composition capable of hydrogenation and silanization curing, alternatively 0.01 wt% to 0.1.0 wt%.

[0105] (e) Adhesion promoters

[0106] Component (e) of the organosilane-curable silicone rubber coating composition is an adhesion promoter comprising an organosilicone bisphenol adduct compound containing a biphenyl unit not directly linked to a silicon atom and at least one Si-H group. The organosilicone bisphenol adduct compound may contain one or more linear or cyclic optionally substituted organosiloxane moieties containing 1 to 50 silicon atoms, alternatively 1 to 30 silicon atoms, and bearing at least one Si-H group. If desired, the adhesion promoter may contain more than two aromatic rings. In one embodiment, the adhesion promoter may be an organosilicone bisphenol adduct compound comprising one or more linear or cyclic optionally substituted organosiloxane moieties containing 1 to 50 silicon atoms, alternatively 1 to 30, alternatively 2 to 20, and most preferably 3 to 10 silicon atoms. These organosiloxane moieties also contain at least one, preferably one to twenty, and most preferably two to ten Si-H groups. If desired or necessary, these organosiloxane moieties may optionally contain one or more additional functional groups, such as alkoxy groups, epoxy groups (such as glycidoxy groups), alkoxysilyl groups (such as trimethoxysilyl groups), triethoxysilyl groups and methyldimethoxysilyl groups, ester groups, acryloyl groups, methacryloyl groups, carboxyl groups, carboxylic anhydride groups, isocyanate groups, amino groups or amide groups. The adhesion promoter must contain two aromatic groups from the biphenyl unit, but may contain three, four or five aromatic groups.

[0107] The organosilicon bisphenol adduct compound can be an organosilicon bisphenol A adduct compound, an organosilicon bisphenol AP adduct compound, an organosilicon bisphenol AF adduct compound, an organosilicon bisphenol B adduct compound, an organosilicon bisphenol BP adduct compound, an organosilicon bisphenol C adduct compound, an organosilicon bisphenol E adduct compound, an organosilicon bisphenol F adduct compound, an organosilicon bisphenol G adduct compound, an organosilicon bisphenol M adduct compound, an organosilicon bisphenol P adduct compound, or an organosilicon bisphenol Z adduct compound. However, preferably, the organosilicon bisphenol adduct compound is an organosilicon bisphenol A adduct compound.

[0108] As noted above, to avoid ambiguity, the biphenyl unit described herein is intended to indicate the presence of the following structure in the adhesion promoter:

[0109] It can be said that the biphenyl unit forms the main chain of this compound. At least one H on one or both aromatic rings can be replaced by another group, and -X 2- can be selected from a methylene bridge, which is selected from -C(CH3)2-, -C(Ph)(CH3)-, -C(Ph)2, -C(CF3)2-, -C(CH3)(C2H5)-, -C(CH2)5-, -C(CH3)(H)-, or -C(H)2-, where Ph is phenyl-. Alternatively, -X 2 The methylene bridge is -C(CH3)2-.

[0110] Based on the preferred methylene bridge, an example of an adhesion promoter can be a bisphenol A diallyl ether having the following structure (i.e., where -X...). 2 -The methylene bridge is -C(CH3)2-)

[0111] With organosilicon rings having the following structure (R 17 H SiO) d+1 The reaction products,

[0112] Where d is an integer from 2 to 7, or alternatively, where d is 3 or 4.

[0113] Therefore, examples of organosilicon bisphenol adduct compound adhesion promoters can have the following structures: -

[0114] Where X 2 As defined above,

[0115] Z 3 It is an alkylene group having 2 to 6 carbon atoms, alternatively 2 to 5 carbon atoms, alternatively 2 to 4 carbon atoms, and alternatively an ethylene or propylene group;

[0116] R 15 It has the structure -(CH3)SiO-(R 14 H SiO) d Cyclic siloxanes;

[0117] R 16 It has a structure (OSiR) 14 H) d -OSi(CH3)- cyclic siloxanes;

[0118] R 14 It is an alkyl group having 1 to 6 carbon atoms, and

[0119] d is an integer from 2 to 7. Alternatively, it may include its oligomers.

[0120] For example, when Z 3 It is propylidene, X 2When the cyclic siloxane is -C(CH3)2- and d is 3, it has four siloxane units (sometimes referred to as D4H in the industry). These siloxane units react with the aforementioned diepoxide to produce an organosilicon bisphenol A adduct compound.

[0121] Where n is an integer from 1 to 5.

[0122] Therefore, when n is 1, the organosilicon bisphenol adduct compound will be

[0123] Other alternatives may include

[0124] or its oligomers,

[0125] Z 3 R 15 R 16 and X 2 As mentioned above

[0126] R 17 It is -Si(CH3)3, -Z 4 R 20 Or -(O=)CCH3,

[0127] R 18 It is (CH3)Si-, R 20 Z 4 -or CH3C(=O)-,

[0128] R 20 It is an epoxide group, and

[0129] Z 4 It is an alkylene group having 2 to 6 carbon atoms.

[0130] or

[0131] or its oligomers,

[0132] Where R 18 X 2 Z 3 and R 15 All are as defined above;

[0133] or

[0134] and its oligomers, wherein R 18 X 2 Z 3 R16 and R 15 All are as defined above;

[0135] or

[0136] The following structure contains an intermediate cyclic siloxane (Y). 2 )

[0137] Where X 2 Z 3 R 16 and R 15 All are as defined above; and

[0138] Y 2 It has the structure -(CH3)SiO-(R 17 H SiO) e -OSi(CH3)- cyclic siloxanes.

[0139] Adhesion promoters provide strong adhesion between the resulting coating and the fabric substrate (including woven fabrics).

[0140] The adhesion promoter (e) is typically present in an amount of about 0.3% to 10% by weight of the composition, alternatively from 1.0% to 7.5% by weight, or alternatively from 1.0% to 5% by weight of the composition in a silicone rubber coating composition capable of hydrogenation and silanization curing.

[0141] Surprisingly, replacing standard adhesion promoters containing reaction products of at least one or more alkoxysilane-based organometallic catalysts (particularly titanates and / or zirconates) with the adhesion promoter (e) presented in this paper not only yields excellent adhesion results but also significantly reduces VOC emissions, not only during the curing process but also, more advantageously, after the curing process is complete. Despite collaborative efforts within the industry, meeting the requirement of carbon emissions below (<) 50 μg C / g (measured by GC-FID according to VDA's test method VDA277 for volatile organic compounds) remains challenging, yet the results obtained in this study demonstrate that this stringent requirement is met.

[0142] Although the following may have been previously proposed in selective adhesive systems for bonding much higher viscosity liquid silicone rubber materials to metals via injection molding:

[0143] Selective adhesion is unsuitable for airbag coatings because the bond between the coating and the substrate must remain intact at all times, which may affect the vehicle's lifespan or the ability to inflate and deploy immediately upon detection of impact in a collision or other accident. Achieving selective adhesion of silicone rubber to preformed thermoplastic substrates via injection molding requires significantly different compositions. Preformed substrates include polycarbonate (PC), polyamide (PA66), and polybutylene terephthalate (PBT), and these silicone selective adhesion compositions can promote adhesion of LSR to thermoplastics using injection molding processes. These compositions differ significantly from the textile and fabric substrates used in airbags. It cannot be inferred, or even assumed, that if the above compositions are suitable for injection molding, they can also serve as suitable adhesion promoters for airbag coatings. Injection molding and coating are entirely different applications with different material requirements. Only selectively adhesive silicone rubbers use adhesion promoters in injection molding applications.

[0144] Preformed substrates are actually quite different from woven fabrics. The surface condition determines the interaction with the substrate, which has a significant impact on adhesion. We cannot simply conclude that what works for thermoplastics will also work for coatings on textiles and fabrics.

[0145] The requirements for airbag coatings go far beyond simply bonding them to the fabric, as the ultimate goal is to stabilize the fabric to prevent premature loss of pressure upon deployment and to enable the airbag to deploy, inflate, and protect the occupants within milliseconds of the initial impact. Therefore, the integrity of the airbag coating is paramount and must be satisfactory when using important new ingredients like adhesion promoters in airbag compositions.

[0146] Furthermore, airbag coatings need to successfully pass tests such as scrub resistance tests, which go far beyond adhesive strength tests, as these are actually tribological tests—a type of sliding friction test. Moreover, the stress transmitted to the interface where the adhesion promoter is believed to chemically interact with the fabric depends on the coating's thickness, uniformity, frictional properties, and overall viscoelasticity. Therefore, one cannot infer that coupling agents effective for injection-molded LSRs will be applied to airbag coatings.

[0147] As part of the testing conducted to evaluate the suitability of the hydrogenated silanized curable silicone rubber coating compositions described herein for use in airbag coatings, the results indicated that injection-molded LSR formulations containing the aforementioned components were unsuitable for coating. It was found that standard injection-molded compositions could not cure effectively without sufficient SiH siloxane in the formulation. Furthermore, the viscosity of the injection-molded compositions was found to be too high to prepare a coating, and their adhesion to fabrics was found to be rather weak, likely due to poor wetting properties on textile and / or fabric substrate surfaces.

[0148] It has been found that compositions used for coating textiles and fabrics (especially airbag fabrics), if containing component (e) of this article, can be used as adhesion promoters to replace conventional adhesion-promoting systems containing organometallic catalysts (typically zirconium-based catalysts) and alkoxysilanes for airbag coatings. Coated fabrics with such airbag coatings exhibit improved TVOC performance, and the resulting cured products will not contain active or partially active condensation catalysts.

[0149] Component (f) (optional)

[0150] Optionally one or more of the silicone resins in the silicone coating composition capable of hydrogenation and silanization curing are silicone resins containing unsaturated groups selected from alkenyl groups, alkynyl groups, or a mixture of alkenyl and alkynyl groups, selected from T silicone resin (silsesquioxane), DT silicone resin, MQ silicone resin, MDT silicone resin, MTQ silicone resin, QDT silicone resin, or mixtures thereof.

[0151] Component (f) of this type of resin using the MDTQ designation contains Q-type (SiO2) resins. 4 / 2 ) siloxane unit, T-type (R 2 1SiO 3 / 2 ) siloxane unit, D-type (R 2 1SiO 3 / 2 ) siloxane unit and R 2 3SiO 1 / 2 (M) Siloxane units, as indicated. These resins can be divided into two main 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 by the hydrolysis and condensation of alkoxysilanes and chlorosilanes. Alternatively, MQ resins can be synthesized by polymerizing an aqueous solution of an alkali metal silicate in the presence of an acid, followed by reaction with a triorganoalkoxysilane, a triorganochlorosilane, a hexaorganodisiloxane, or mixtures thereof.

[0152] Preferably, component (f) is one or more MQ resins. Typically, when present, the MQ resin of component (f) contains SiO2. 4 / 2 (Q) Siloxane unit and R 2 3SiO 1 / 2 (M) siloxane units, wherein each R 2 They may be the same or different, and represent a monovalent group selected from hydrocarbon groups having 1 to 20 carbon atoms, and alternatively 1 to 12 carbon atoms. A suitable R 2 Examples of groups include alkyl groups, such as methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl; alicyclic groups, such as cyclohexyl; alkenyl groups having 2 to 12 carbons, such as vinyl, propenyl, butenyl, pentenyl, and hexenyl; alkynyl groups selected from ethynyl, propynyl, butynyl, pentynyl, or 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, preferably R. 2 3SiO 1 / 2 Examples of (M) siloxane units include Me3SiO 1 / 2 PhMe2SiO 1 / 2 ViMe2SiO 1 / 2 and Ph2MeSiO 1 / 2 In this context, Me represents methyl, Vi represents vinyl, and Ph represents phenyl. Alternatively, the T silicone resin may be referred to as sesquioxane. Silicone resins can be a single silicone resin or a mixture containing two or more different silicone resins (each as described above). Typically, they are ViMe2SiO 1 / 2

[0153] With Me3SiO 1 / 2 and / or PhMe2SiO 1 / 2 MQ resin with a combination of functional groups.

[0154] In addition, silicone resins may contain residual OZ. 5 MQ resin, of which Z 5 It can represent hydrogen or alkyl groups. OZ 5 The presence of groups on the Q component after the synthesis of the organosilicon MQ resin indicates incomplete condensation during the reaction process, provided that the OZ content meets the aforementioned requirement of hydroxyl groups per mole of Si. Residual OZ 5 This is inherent to the process and reactions used in the manufacture of MQ resin. The MQ resin can also undergo subsequent silylation reactions to further minimize residual OZ. 5 .

[0155] When present, silicone resin (f) is typically delivered in a hydrocarbon or silicone solvent. In the absence of a solvent, silicone resin is typically a solid, but it is preferred herein that silicone resin (f) is delivered in a silicone solvent such as a nonfunctionalized polydimethylsiloxane or a polydimethylsiloxane containing two or more alkenyl groups per molecule (such as component (a) herein, for example).

[0156] For example, any suitable MQ resin can be used as component (f) if desired. 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, or alternatively 0.9:1 to 1.1:1. In one embodiment, the MQ resin (e) comprises a resinous portion wherein the M units are bonded to SiO2. 4 / 2 On siloxane units (i.e., Q units), and each Q unit is bonded to at least one other SiO2. 4 / 2 On the siloxane unit. The molar ratio of M unit to Q unit 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 resin, suitable as component (f), 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 according to the molar fraction as an MQ silicone resin having the following formula:

[0157] Where R 4 It is C1 to C1 without aliphatic unsaturation. 10 The hydrocarbon group, 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.

[0158] Methods for preparing organosilicon resins are well known in the art. For example, they can be prepared by treating resin copolymers produced by silica hydrosol end-capping methods with end-capping agents containing alkyl and / or alkenyl groups. This method preferably includes reacting a silica hydrosol with hydrolyzable triorganosilanes (such as trimethylchlorosilane), siloxanes (such as hexamethyldisiloxane), and combinations thereof under acidic conditions, followed by recovery of the M(R3SiO) group. 1 / 2 ) unit and Q(SiO) 4 / 2 A copolymer comprising 0.07 to 0.2 moles of hydroxyl groups per mole of silicon (Si). This copolymer can be further reacted with a capping agent comprising saturated organic groups to achieve less than 0.06 moles of hydroxyl groups per mole of Si. Suitable capping agents include silazanes, siloxanes, silanes, and combinations thereof.

[0159] The silicone resin (f) is typically delivered in a hydrocarbon or silicone solvent. In the absence of a solvent, the silicone resin is usually a solid, but it is preferred herein that the silicone resin (f) is delivered in a silicone solvent such as a nonfunctionalized polydimethylsiloxane or a polydimethylsiloxane containing two or more alkenyl groups per molecule (such as component (a) of this document, for example). For example, any suitable MQ resin can be used as component (f). The molar ratio of M siloxane units to Q siloxane units has values ​​of 0.5:1 to 1.2:1, alternatively 0.6:1 to 1.1:1, alternatively 0.8:1 to 1.1:1, and alternatively 0.9:1 to 1.1:1. In one embodiment, the MQ resin (f) comprises a resinous portion wherein the M units are bonded to SiO₂. 4 / 2 On siloxane units (i.e., Q units), and each Q unit is bonded to at least one other SiO2. 4 / 2 On the siloxane unit. The molar ratio of M unit to Q unit is 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. Such MQ resin, suitable as component (f), 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.

[0160] When present, the amount of component (f) in the organosilicon rubber coating composition capable of hydrogenation and silanization curing can be from 1% to 60% by weight, alternatively from 1% to 40% by weight, and preferably in the form of MQ resin.

[0161] Methods for preparing organosilicon resins are well known in the art. For example, they can be prepared by treating resin copolymers produced by silica hydrosol end-capping methods with end-capping agents containing alkyl and / or alkenyl groups. This method preferably includes reacting a silica hydrosol with hydrolyzable triorganosilanes (such as trimethylchlorosilane), siloxanes (such as hexamethyldisiloxane), and combinations thereof under acidic conditions, followed by recovery of the M(R3SiO) group. 1 / 2 ) unit and Q(SiO) 4 / 2 A copolymer comprising 0.07 to 0.2 moles of hydroxyl groups per mole of silicon (Si). This copolymer can be further reacted with a capping agent containing saturated organic groups to achieve less than 0.06 moles of hydroxyl groups per mole of Si. Suitable capping agents include silazanes, siloxanes, silanes, and combinations thereof.

[0162] Components (a), (c), and (f) are always mixtures of macromolecules 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 average polymer molecular weights are number-average molecular weight (Mn) and weight-average molecular weight (Mw). 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 produces Mw, Mn, and the polydispersity index (PI). Degree of polymerization (DP) = Mn / Mu, where Mn is the number-average molecular weight measured from GPC, and Mu is the molecular weight of the monomer unit. PI = Mw / Mn. DP is related to the viscosity of the polymer via Mw; the higher the DP, the higher the viscosity. Silicone resins typically have a weight-average molecular weight (Mn) of 2,000 to 50,000 Daltons, alternatively 3,000 to 40,000 Daltons, alternatively 3,000 to 30,000 Daltons, alternatively 4,000 to 30,000 Daltons, and alternatively 5,000 to 25,000 Daltons. w The molecular weight was determined by gel permeation chromatography using a triple detector system (e.g., light scattering detector, refractive index detector, and / or viscosity detector) and polystyrene standards.

[0163] Additional optional ingredients

[0164] Depending on the intended end use, additional optional ingredients may be present in the silicone rubber coating compositions capable of hydrogenation and silanization curing as described above. Examples of such optional ingredients include curing inhibitors, pot life extenders, flame retardants, lubricants, non-reinforcing fillers, pigments and / or colorants, bactericides, wetting agents, heat stabilizers, compression set additives, plasticizers, and mixtures thereof.

[0165] When the organosilicon coating composition that can be cured by hydrosilylation as described above is cured via an addition / hydrosilylation reaction, inhibitors can be used to suppress 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 of the hydrosilylation-cured composition by delaying or inhibiting the activity of the catalyst. Inhibitors of the hydrosilylation catalyst (d) (e.g., platinum-based catalysts) are well known in the art and may include hydrazides, triazoles, phosphines, thiols, organonitrogen compounds, alkynols, silylated alkynols, maleate esters (such as dibutyl maleate), fumarate esters, olefinic or aromatic unsaturated amides, olefinic unsaturated isocyanates, olefin siloxanes (such as tetramethyltetravinylcyclotetrasiloxane), unsaturated hydrocarbon monoesters and diesters, conjugated alkynylenes, hydroperoxides, nitriles, and diazacyclopropanes. Alkenyl-substituted siloxanes, as described in US 3,989,667, may be used, with cyclic methyl vinyl siloxanes being preferred.

[0166] Known inhibitors of hydrosilylation catalysts, such as platinum catalysts (d), include alkynyl compounds disclosed in US 3,445,420. Alynyl alcohols (such as 2-methyl-3-butyn-2-ol) constitute a preferred class of inhibitors, which inhibit the activity of platinum-containing catalysts at 25°C. Compositions containing these inhibitors typically require heating at 70°C or higher to achieve a practical curing rate.

[0167] 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-penten-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.

[0168] In some cases, an inhibitor concentration as low as 1 mole of inhibitor per mole of catalyst (d) will impart satisfactory storage stability and curing rate when present. In other cases, an inhibitor concentration of up to 500 moles of inhibitor per mole of catalyst (d) is required. The optimal concentration of a given inhibitor in the given hydrosilylated curable silicone coating composition described herein can be readily determined by routine experiments. The mixtures described above may also be used. Depending on the concentration and form of the selected inhibitor provided / commercially available, the amount of inhibitor present in the composition is typically from 0.0001 wt% to 10 wt%, alternatively from 0.001 wt% to 5 wt%, alternatively from 0.0125 wt% to 5 wt%. Pot life extenders, such as triazoles, may be used, but are not considered essential within the scope of this invention. Therefore, hydrosilylated curable silicone rubber coating compositions may be free of pot life extenders.

[0169] Examples of flame retardants include calcium carbonate (e.g., precipitated calcium carbonate), aluminum trihydrate (ATH), magnesium dihydroxyl hydroxide (MDH), and HMH (a mixture of magnesia and calcium carbonate), chlorinated paraffin, hexabromocyclododecane, triphenyl phosphate, dimethyl methylphosphonate, tris(2,3-dibromopropyl) phosphate (tribromoester), and mixtures or derivatives thereof. When present in the composition, the amount of the flame retardant may be from 5% to 50% by weight of the composition, if desired.

[0170] 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 a silicone rubber coating composition capable of hydrogenation and silanization curing, the amount of flame retardant is typically from 0.1% to 5% by weight of the composition.

[0171] Non-reinforcing fillers may include pulverized quartz, diatomaceous earth, barium sulfate, iron oxide, titanium dioxide and carbon black, talc, and wollastonite. Other fillers that may be used alone or in combination with the above fillers include: alumina, calcium sulfate (anhydrite), gypsum, calcium sulfate, magnesium carbonate, clay (such as kaolin), magnesium hydroxide (e.g., brucite), graphite, copper carbonate (e.g., malachite), nickel carbonate (e.g., niobite), barium carbonate (e.g., barite), and / or strontium carbonate (e.g., strontium strontium).

[0172] Other fillers may include alumina, silicates selected from the group consisting of: olivine; garnet; aluminosilicates; cyclosilicates; chain silicates; and platy silicates. Olivine includes silicate minerals such as, but not limited to, forsterite and Mg2SiO4. Garnet includes ground silicate minerals such as, but not limited to, pyrope; Mg3Al2Si3O4. 12Grossular garnet and Ca2Al2Si3O 12 Aluminosilicates include milled silicate minerals such as, but not limited to, sillimanite; Al₂SiO₅; mullite; 3Al₂O₃.₂SiO₂; kyanite; and Al₂SiO₅. Cyclic silicates can be used as non-reinforcing fillers; these include silicate minerals such as, but not limited to, cordierite and Al₃(Mg,Fe)₂[Si₄AlO₂]. 18 Chain silicates include ground silicate minerals, such as, but not limited to, wollastonite and Ca[SiO3]. Flake silicates may alternatively or otherwise be used as non-reinforcing fillers, wherein suitable classes contain silicate minerals, such as, but not limited to, mica; K2Al 14 [Si6Al2O 20 (OH)4; pyrophyllite; Al4[Si8O 20 (OH)4; Talc; Mg6[Si8O 20 (OH)4; serpentine, for example asbestos; kaolinite; Al4[Si4O] 10 (OH)8; and vermiculite. In an alternative form, the filler will be selected from one or more of the following: pyrolytic silica, precipitated silica, calcium carbonate, talc, mica, quartz, and alumina.

[0173] Examples of pigments include titanium dioxide, chromium trioxide, bismuth vanadium oxide, iron oxide, and mixtures thereof.

[0174] Examples of colorants that can be used in hydrogen silanization-curable silicone coating compositions include pigments, vat dyes, reactive dyes, acid dyes, chromium dyes, disperse dyes, cationic dyes, and mixtures thereof. Hydrogen silanization-curable silicone rubber coating compositions as described herein may also contain one or more pigments and / or colorants, which may be added if desired. Pigments and / or colorants can be colored, white, black, metallic, and luminescent, such as fluorescent and phosphorescent. Pigments are used to color the composition as needed. Any suitable pigments that are compatible with the compositions described herein can be utilized.

[0175] Suitable white pigments and / or colorants include titanium dioxide, zinc oxide, lead oxide, zinc sulfide, zinc barium white, zirconium oxide, and antimony oxide.

[0176] Suitable non-white inorganic pigments and / or colorants include, but are not limited to, iron oxide pigments such as goethite, lepidocrocite, hematite, maghemite, and maghemite black, yellow, brown, and red iron oxides; 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; mixed metal oxide pigments such as cobalt titanate green; chromate and molybdate pigments such as chrome yellow, molybdenum red, and molybdenum orange; ultramarine pigments; cobalt oxide pigments; nickel antimony titanate; lead chromium; carbon black; lampblack; and metallic effect pigments such as aluminum, copper, copper oxide, bronze, stainless steel, nickel, zinc, and brass.

[0177] Suitable organic non-white pigments and / or colorants include phthalocyanine pigments, such as phthalocyanine blue and phthalocyanine green; monoaryl yellow, diaryl yellow, benzimidazolone yellow, heterocyclic yellow, DAN orange, quinacridone pigments, such as quinacridone magenta and quinacridone violet; organic reds, including metallized azo red and non-metallized azo red, as well as other azo pigments, monoazo pigments, diazo pigments, azo pigment lakes, β-naphthol pigments, naphthol AS pigments, benzimidazolone pigments, diazo condensation pigments, isoindolineone and isoindoline pigments, polycyclic pigments, perylene and fenone pigments, thioindole pigments, anthraquinone pigments, yellow anthrone pigments, anthraquinone pigments, dioxazine pigments, triarylcarbene pigments, quinacridone pigments, and diketopyrrolopyrrole pigments.

[0178] Typically, when in particulate form, the average particle size of the pigment and / or colorant is in the range of 10 nm to 50 μm, preferably in the range of 40 nm to 2 μm. The pigment and dye can be used in the form of a pigment masterbatch, which consists of them dispersed in component (a) at a ratio of 25:75 to 70:30.

[0179] Silicone coating compositions capable of hydrogenation-silanization curing can be heat-stable. Examples of heat stabilizers may include metal compounds such as red iron oxide, yellow iron oxide, iron hydroxide, cerium oxide, cerium hydroxide, lanthanum oxide, copper phthalocyanine, pyrolytic titanium dioxide, iron naphthenate, cerium naphthenate, dimethyl polysilanol cerium, and acetylacetone salts of metals selected from copper, zinc, aluminum, iron, cerium, zirconium, titanium, etc. Other examples of heat stabilizers may include suitable antioxidants or metal scavengers such as salicylaminotriazole, 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)dodecanedihydrazine. When present in a silicone coating composition capable of hydrogenation and silanization curing, the amount of heat stabilizer may be in the range of 0.01% by weight to 1.0% by weight of the silicone rubber coating composition capable of hydrogenation and silanization curing.

[0180] Therefore, the organosilicon rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics comprises:

[0181] a) An organopolysiloxane polymer (a) having the following viscosities, wherein in each case the viscosity of component (a) organopolysiloxane polymer (a) at 25°C should be between 100 mPa·s and 200,000 mPa·s and including the extreme values, alternatively 1,000 mPa·s to 150,000 mPa·s, alternatively 1,000 mPa·s to 125,000 mPa·s, alternatively 1,000 mPa·s to 70,000 mPa·s, each molecule having at least two unsaturated groups selected 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; unless otherwise specified, all given viscosity measurements are based on ASTM D 4287, measured using a Brookfield cone / plate viscometer with a CP-52 rotor at 1 rpm.

[0182] b) Optional reinforcing filler comprising pyrolytic silica, precipitated silica, or mixtures thereof; having a particle size of at least 50 μm. 2 / g (according to the BET method of ISO 9277:2010), additionally select 50m 2 / g to 450m 2 / g, another 50m 2 / g to 400m 2 / g, another 50m 2 / g to 300m 2 / g, another 100m 2 / g to 300m 2 / g (according to the BET method of ISO 9277:2010); the reinforcing filler (b) is generally treated to make it hydrophobic, and its presence is based on the weight % of the composition, ranging from 1.0 wt% to 50 wt% of the composition, alternatively from 1 wt% to 30 wt% of the composition, or alternatively from 5.0 wt% to 25 wt% of the composition;

[0183] c) An organosilicon compound having at least two, alternatively at least three Si-H groups per molecule, preferably wherein 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, and 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 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 amount of the organosilicon compound having at least two, or alternatively at least three, Si-H groups per molecule in the organosilicon coating composition capable of hydrogenation silanization curing is from 0.1% by weight to 10% by weight, alternatively from 0.1% by weight to 7.5% by weight, alternatively from 0.5% by weight to 7.5% by weight, and further alternatively from 0.5% by weight to 5% by weight of the organosilicon coating composition capable of hydrogenation silanization curing. Component (c) acts as a crosslinking agent; (d) is a hydrogenation silanization curing catalyst, wherein the catalytic amount of the hydrogenation silanization catalyst is between 0.01 ppm (parts per million) and 10,000 parts by weight of platinum group metals, based on the weight of the silicone rubber coating composition capable of hydrogenation silanization curing; alternatively, between 0.1 ppm and 7,500 ppm; alternatively, between 100 ppm and 75,000 ppm of metals, and alternatively between 500 ppm and 6,000 ppm of metals, based on the weight of the composition, and wherein the amount of component (d) present in the composition will be between 0.001 wt% and 3 wt%, depending on the form / concentration provided by the catalyst (e.g., in a polymer or solvent). 0% by weight, alternatively 0.001% by weight to 1.5% by weight of the composition, alternatively 0.01% by weight to 1.5% by weight of the organosilicon coating composition capable of hydrogenation and silanization curing, alternatively 0.01% by weight to 0.1.0% by weight; (e) an adhesion promoter comprising an organosilicon bisphenol adduct compound comprising a biphenyl unit not directly bonded to a silicon atom, and at least one Si-H group; the adhesion promoter (e) is typically present in the composition in an amount of about 0.5% by weight to 10% by weight of the composition, alternatively 1% by weight to 7.5% by weight of the composition, alternatively 1% by weight to 5% by weight of the composition;

[0184] And optional

[0185] f) One or more silicone resins selected from T silicone resin (silsesquioxane), DT silicone resin, MQ silicone resin, MDT silicone resin, MTQ silicone resin, QDT silicone resin, or mixtures thereof, in an amount of 1% to 60% by weight of the composition, or alternatively 1% to 40% by weight. The total weight percentage of the composition is 100% by weight.

[0186] When component (f) is present, it is preferably an MQ type resin.

[0187] Furthermore, the coated textile material described herein is a textile material coated with the cured product of the aforementioned organosilicon rubber coating composition capable of hydrogenation and silanization curing.

[0188] Typically, before use, silicone rubber coating compositions capable of hydrogen silanization curing are stored in two parts (Part A and Part B) to keep components (c) (crosslinking agent) and (d) the hydrogen silanization curing catalyst separate, thereby avoiding premature curing. Part A typically contains the following components: (a) a polymer, (b) an optional reinforcing filler (if present), and (d) the hydrogen silanization curing catalyst, while Part B typically contains the following components: (a), (c) a crosslinking agent, (b) a reinforcing filler (if present), and an inhibitor (if present). Component (e) an adhesion promoter is typically stored in Part B of the composition.

[0189] When additives are present in a hydrosilane-curable silicone rubber coating composition for treating textiles and fabrics, they can be in either part A or part B, provided that they do not negatively affect the properties of any other components present (e.g., catalyst deactivation). Part A and part B of the hydrosilane-curable silicone coating composition described herein are mixed together shortly before use to initiate the curing of the entire composition into a silicone elastomer material. The part A and part B compositions can be designed to be mixed in any suitable weight ratio; for example, part A: part B can be mixed in a weight ratio of 10:1 to 1:10, alternatively 5:1 to 1:5, alternatively 2:1 to 1:2, but a 1:1 weight ratio is most preferred.

[0190] The components of each of Part A and / or Part B may be mixed individually or introduced into the composition in a pre-prepared combined form, for example, to facilitate mixing of the final composition. For example, components (a) and (b) (when the latter is present) are often mixed together to form an LSR polymer base or masterbatch before being mixed with other components. Similarly, component (e) may be pre-mixed with component (a) if desired. These can then be mixed with other components of the directly prepared part or used to prepare a pre-concentrated concentrate, commonly referred to in the industry as a masterbatch.

[0191] In this case, to facilitate the mixing of components, one or more masterbatches can be used to successfully mix these components to form a part A composition and / or a part B composition, especially when component (b) is present. For example, a "pyrolytic silica" masterbatch can be prepared. This is essentially an LSR silicone rubber base material with in-situ treated silica.

[0192] Parts A and B of a silicone rubber coating composition capable of hydrogenation and silanization curing can be prepared by combining all their respective components at ambient temperature. Any mixing techniques and apparatus described in the prior art can be used for this purpose. The specific apparatus 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 prevent premature curing of the composition.

[0193] Before use, mix the corresponding A and B components together in the desired ratio.

[0194] As part of the methods described herein, the coating composition as described above can be applied to a fabric substrate (typically a one-piece woven or flat fabric airbag substrate) using any suitable known technique. These techniques include spraying, gravure coating, doctor blade coating, doctor blade coating (e.g., coating through a doctor blade roller liner, coating through a doctor blade air cushion); padding, dipping, and screen printing.

[0195] The silicone rubber coating composition capable of hydrogenation and silanization curing can be applied to one or both sides of a textile or fabric substrate (e.g., airbag fabric to be cut into pieces and sewn together to assemble an airbag), or it can be applied to a one-piece woven airbag.

[0196] The curing of the present invention’s organosilicon coating composition capable of hydrogenation and silanization curing, applied to woven fabrics, is typically carried out by heating the composition at a temperature of 150°C to 200°C for 45 seconds to 2 minutes, which can be accomplished using a suitable oven or by a drying tunnel in a circulating hot air oven.

[0197] Although not preferred, the composition can be applied in multiple layers, which together have a predetermined average dry coating weight that can be measured according to ISO 3801. If deemed necessary, another compatible coating may also be applied to the coating composition, for example, providing a material with low friction.

[0198] Any suitable desired coating weight, such as 15 g / m², can be applied to textiles or fabric materials (such as airbags). 2 Up to 150g / m 2 , another selection of 15g / m 2Up to 100g / m 2 , another 20g / m 2 Up to 75g / m 2 The coating weight was determined according to ISO 3801. The coating thickness depends on the coating weight and ranges from 20 μm to 80 μm.

[0199] Textiles or fabric substrates

[0200] The textile or fabric substrate to which the silicone rubber coating composition capable of hydrogenation and silanization curing is applied can be made of any suitable woven fabric (particularly plain weave fabric), but can also be, for example, knitted or nonwoven fabric. The fabric or textile material can be made of synthetic fibers or blends of natural and synthetic fibers, such as 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 blends, polyacrylonitrile fiber fabrics, aromatic polyamide fiber fabrics, polyetherimide fiber fabrics, polysulfone fiber fabrics, carbon fiber fabrics, rayon fiber fabrics, and / or glass fiber.

[0201] When processing airbags, the airbag can be a one-piece woven airbag or a flat fabric sheet coated and sewn together to provide sufficient mechanical strength. Such airbags are typically made of polyamide or polyester fabrics and are used in applications requiring high strength, particularly in the case of one-piece woven airbags for automobiles. The woven fabric is preferably washed with water and dried before being coated with the hydrogenated silanization-curable silicone rubber coating composition described herein.

[0202] For use as airbag fabric, the fabric should be flexible enough to fold into a relatively small volume, but also strong enough to withstand high-speed deployment, for example, under the action of an explosive inflation device. Polyamides and polyesters are particularly preferred for manufacturing airbag textiles; however, bonding coatings to polyamide and polyester airbags can be difficult, thus requiring adhesion promoters such as component (e) of this article, which have surprisingly been found suitable as adhesion promoters for airbag coatings because, when it replaces standard adhesion promoters, it provides the necessary adhesion between the coating and the textile or fabric substrate, and advantageously significantly reduces TVOC emissions to levels preferred by vehicle manufacturers and OEMs.

[0203] The coating prepared by curing the composition of this paper using an adhesion promoter (e) stabilizes the fabric to prevent premature loss of pressure upon deployment and enables the airbag to deploy, inflate, and protect the occupants within milliseconds of the first impact in a collision. The resulting coating possesses the necessary coating integrity, cured mechanical / viscoelastic properties, and satisfactory surface lubricity, key characteristics that cannot be guaranteed when the adhesion promoter is replaced.

[0204] Therefore, the coating compositions described herein are designed to exhibit particularly good adhesion and film-forming properties upon initial contact with the fabric, resulting in a uniform film formation on the coated fabric surface. Preferably, they also possess good permeability into the fabric.

[0205] An airbag obtained by coating an uncoated airbag fabric with a silicone coating composition capable of hydrogenation and silanization curing as described herein has at least one coating formed by the cured product of the silicone coating composition capable of hydrogenation and silanization curing as described herein. However, one or more additional layers may be provided on the coated fabric if desired. Such additional layers are generally used to improve the tactile feel of the coated fabric surface, improve the abrasion resistance of the coated fabric surface, and / or improve the strength of the coated fabric. Additional coatings may be exemplified as plastic films, woven fabrics, nonwoven fabrics, or coatings formed from elastic coating materials other than the cured silicone rubbers disclosed herein. It is preferred that additional layers are not required or undesirable.

[0206] This technology can be used in any suitable textile and / or fabric application, but is particularly suitable for airbag applications, especially in the automotive market, but also applicable to, for example, aircraft escape slides. The coating formed by curing the silicone coating composition described herein, capable of hydrogenation and silanization curing, exhibits excellent adhesion to substrates used for airbag fabrics. Excellent adhesion durability to a variety of fabrics provides long-term stability of the coated fabric under thermal and moisture aging conditions, thereby improving airbag reliability. Furthermore, the introduction of the adhesion promoter (e) provides users with significantly improved TVOC compared to standard adhesion promoter combinations used in the industry for airbag coatings. When tested according to VDA277, the coating gives a carbon emission result of less than 50 μg C / g, a significant improvement compared to standard adhesion promoters used in the industry, resulting in more environmentally friendly and sustainable airbags and better in-vehicle air quality.

[0207] Therefore, the composition containing component (e) as an adhesion promoter described herein exhibits superior flowability, mechanical strength, improved adhesion to woven fabrics, and lower total volatile organic compound (TVOC) content compared to conventional airbag coating LSR materials that use a combination of organometallic catalysts and alkoxysilanes as adhesion promoters. Example

[0208] In the following examples, unless otherwise stated, the compositions are defined in weight percent (wt.%).

[0209] The content of vinyl groups and Si-H groups was measured by infrared spectroscopy according to ASTM E168 standards for carbon double bond elongation and organosilicon hydrogen bond elongation.

[0210] All compositions had a Si-H:Si-vinyl molar ratio of 1.6:1, and all viscosity measurements were performed at 25°C unless otherwise specified.

[0211] A series of compositions were prepared, and their suitability as textile coatings, particularly airbag coatings, was analyzed. The prepared liquid silicone rubber compositions were formulated as two-part compositions, namely part A and part B. Part A and part B were mixed before curing to prepare the final composition. The composition was kept in both parts until use to ensure that premature curing was avoided. The compositions of part A and part B are provided in Tables 1a to 1d below, and the compositions were mixed together in a 1:1 weight ratio before use.

[0212] Table 1a: Composition of Part A and Part B (by weight) of Comparative Examples 1 and 2, and Examples 1 and 2

[0213]

[0214] Table 1b: Composition (by weight) of Part A and Part B of Comparative Examples 3 and 4, and Examples 3 and 4

[0215]

[0216] Table 1c: Composition of Part A and Part B (by weight) of Comparative Examples 5, 6 and 7

[0217]

[0218] Comparative Example 7 is a liquid silicone rubber composition designed for injection molding.

[0219] Table 1d: Composition of Part A and Part B (by weight) of Examples 5, 6, 7 and 8

[0220]

[0221] In the compositions described in Tables 1a to 1d:

[0222] Organosilicon polymer 1 is a vinyl-terminated polydimethylsiloxane, with a viscosity of approximately 60,000 mPa·s, measured at 1 rpm using a Brookfield cone / plate viscometer with a CP-52 rotor, based on ASTM D 4287.

[0223] Organosilicon polymer 2 is a vinyl-terminated polydimethylsiloxane, based on ASTM D 4287, with a viscosity of approximately 10,000 mPa·s measured at 1 rpm using a Brookfield cone / plate viscometer with a CP-52 rotor.

[0224] Organosilicon polymer 3 is a vinyl-terminated polydimethylsiloxane, based on ASTM D 4287, with a viscosity of approximately 2,000 mPa·s measured using a Brookfield cone / plate viscometer with a CP-52 rotor at 3 rpm.

[0225] Masterbatch 1 is a mixture of organosilicon polymer 1 (73 wt%) and pyrolytic silica (27 wt%) treated in situ with hexamethyldisilazane (HMDZ), which is used as CAB-O-SIL. ™ MS-75D pyrolytic silica (available commercially from Cabot Corporation) is available for sale.

[0226] Organosilicon resin MB1 is a mixture of 73% by weight of polymer 1 and MQ organosilicon resin (27% by weight), the structure of which is M. 37 M Vi 5Q 58 OH8,

[0227] Organosilicon resin MB2 is a mixture of 67% by weight polymer 3 and 33% by weight MQ organosilicon resin, the structure of which is M. 37 M Vi 5Q 58 OH8,

[0228] The cassiterite is a specification of cassiterite containing 5,000 ppm Pt;

[0229] Crosslinking agent 1 is a trimethylsilyl-terminated dimethyl, methylhydrosiloxane, with a viscosity of 15 mm, measured according to Dow Chemical's test method CTM 0004 (based on ASTM D-445). 2 / s (centitole), H content is 0.8% by weight%

[0230] Crosslinker 2 is a trimethylsilyl-terminated methylhydrosiloxane, with a viscosity of 30 mmHg as measured according to Dow Test Method CTM0004 (based on ASTM D-445). 2 / s (centitole), H content is 1.6% by weight;

[0231] Crosslinking agent 3 is a trimethylalkyl-terminated dimethyl,methylhydrosiloxane, with a viscosity of 45 mmHg, measured according to Dow Chemical's test method CTM0004 (based on ASTM D-445). 2 / s (centitole), H content is 0.7% by weight;

[0232] Dow Test Method CTM 0004 is available to the public upon request.

[0233] Adhesion promoter 1 is

[0234] ETCH stands for ethynylcyclohexanol;

[0235] The binder catalyst is a mixture of 50% by weight zirconium acetylacetonate in polymer 2;

[0236] Alkoxysilane is γ-glycidoxypropyltrimethoxysilane;

[0237] HMH packing is UltraCarb ™ LH3C is a mixture of calcium carbide and hydromagnesia in a weight ratio of 4:6, and is commercially available from LKAB.

[0238] Calcium carbonate is Hakuenka ™ CC-R is fatty acid-treated precipitated calcium carbonate, which is commercially available from Shiraishi-Omya GmbH.

[0239] Preparation process

[0240] Although any suitable method may be used, to prevent premature curing unless the composition will be used immediately, it is prepared in two parts, namely Part A and Part B. As a first step, when necessary, the components shown in Table 1 are mixed in a kneader mixer, and then residual water and treatment agent are vaporized to prepare an in-situ treated pyrolytic silica masterbatch. Similarly, when present, the silicone resin (f) is premixed with component (a) before being mixed with the other components.

[0241] Each Part A and Part B composition was then prepared using the components identified in Tables 1a to 1d. The corresponding Part A and Part B compositions were then mixed together, and the resulting compositions were either coated onto textile materials or prepared for the physical property tests described below. The coating of the airbag substrate used in the examples was performed manually using a laboratory coating machine commercially available from Werner Mathis AG. The coating temperature used was 190°C, and the curing time was 1 minute. The coating weight, determined according to ISO 3801, was approximately 25 g / m³. 2 .

[0242] The zero-shear viscosity of the mixed composition (i.e., part A + part B) was measured at 25°C before heat curing, and the results are shown in Tables 2a and 2b below. Zero-shear viscosity (η)o The viscosity-shear rate value is obtained by extrapolating measurements at low shear rates to zero (or simply averaging) within the range where the viscosity-shear rate curve is independent of the rate. This value is independent of the testing method and is measured using an Anton Paar MCR-301 rheometer equipped with a cone-plate clamp at a series of low shear rates (such as 0.01 s⁻¹) under conditions not exceeding the sensor torque limit. -1 0.1s -1 and 1.0s -1 This was carried out under the following conditions.

[0243] Table 2a: Comparative Examples C.1 to C.4 and Examples Ex.1 to Ex.4, as shown in Tables 1a and 1b, before curing, their most... Zero-shear (ZS) viscosity (Pa.s) of the final composition (part A + part B) at 25°C .

[0244]

[0245] Table 2b: Comparative Examples C.5, C.6, and C.7 and Examples Ex.5 to Ex.8 as shown in Tables 1c and 1d, in terms of curing... Previously, the zero-shear viscosity (Pa.s) of the final composition (part A + part B) at 25°C was measured. .

[0246]

[0247] As can be seen in Tables 2a and 2b, the addition of adhesion promoter 1 did not affect the viscosity of C.5 and C.6, as well as the final compositions of Examples 5 through 8. They still exhibited excellent flowability suitable for coating applications. The viscosity of injection-molded liquid silicone rubber (LSR) C.7 was much higher than that of the coating LSR, which typically had a viscosity of less than 100 Pa·s at a shear rate of 10.0 / s. Due to the high viscosity of C.7, the composition exhibited poor or low flowability, which would significantly negatively impact the wettability and penetration of C.7 onto fabric substrates, and thus negatively affect the adhesion between the composition and the substrate.

[0248] Preparation of cured sheets

[0249] Cured silicone sheets were also prepared to evaluate the physical properties of the samples. These sheets were molded into 2 mm thick sheets at a curing temperature of approximately 120°C for 10 minutes. No post-curing was performed on the samples.

[0250] Methods for measuring the mechanical properties of silicone rubber

[0251] The physical properties of the comparative and example samples were prepared and analyzed, and the results are shown in Tables 3a and 3b below.

[0252] For this analysis, in each case, a 2 mm thick cured silicone rubber specimen was obtained by pressurizing the curable liquid silicone rubber composition at 120°C and 30 tons of pressure for 10 minutes. The hardness of the silicone rubber was measured using a Shore A hardness tester according to ASTM D 2240. Tensile strength, elongation at break, and modulus results were determined according to ASTM D412, tear strength was determined according to ASTM D624 using a C-die, and specific gravity (relative density) was measured according to ASTM D792 using Test Method A.

[0253] Table 3a: Curing of the compositions of Comparative Examples C.1 to C.4 and Examples Ex.1 to Ex.4 as shown in Tables 1a and 1b Physical property measurements of the product .

[0254]

[0255] Table 3b: Compositions of Comparative Examples C.5, C.6, and C.7 and Examples Ex.5 to Ex.8 as shown in Tables 1c and 1d. Physical property measurements of the cured product .

[0256]

[0257] The results in Tables 3a and 3b show that the addition of adhesion promoter 1 did not affect the physical properties of the final formulations of Examples 1 to 8. Examples 1 to 8 exhibited tensile strength, elongation, and hardness comparable to Comparative Examples C.1 to C.6, indicating that adhesion promoter 1, containing multiple SiH groups, can also act as a crosslinking agent to react with vinyl groups and then form a crosslinked structure. The mechanical strength of injection-molded LSR C.7 is much higher than that of coated LSR, therefore its physical properties are completely different from those of the coating composition.

[0258] Total volatile organic compounds (TVOC)

[0259] An airbag fabric made of 420 decibels of polyamide 66 (PA66) (decibels refer to the weight in grams of 10,000 meters of textile yarn (sewing thread)) was obtained and used as a textile carrier for coating the compositions in Tables 1a to 1d above, the coatings being applied thereon and cured at 190°C for 1 minute.

[0260] The coating of each coated sample was analyzed for TVOC according to the VDA277 test method. The target value sought was less than or equal to (≤) 50 μg C / g.

[0261] The same tests were also conducted when the composition of Example 5 was coated onto a substitute substrate, 550-point polyethylene terephthalate (PET) airbag fabric.

[0262] Table 4a: TVOC results of the compositions in Tables 1a and 1b on 420d PA66 as determined by VDA277, with a target of ≤ 50μgC / g

[0263]

[0264] Table 4b: TVOC results of the compositions in Tables 1c and 1d as determined by VDA277, with a target of ≤50 μgC / g.

[0265]

[0266] As can be seen from Tables 4a and 4b, the TVOC results of all examples are significantly improved compared to the comparative examples. The TVOC values ​​of the examples containing component (e) of the composition are all below 50 μg C / g. In fact, the TVOC values ​​of Examples 5 to 8 are all 30 μg C / g or below. Currently, achieving 30 μg C / g is becoming the ultimate goal in the automotive industry, which can be achieved by replacing the traditional adhesion promoter combination containing metal chelates and silanes with a novel adhesion promoter.

[0267] The coated fabric samples were also evaluated for flexural abrasion according to ISO 5981 Method A, with a target of at least 600 cycles of cyclic friction. Failure modes were also recorded, with the target outcome being "pinhole" (PH) failure rather than delamination (D) failure.

[0268] The term "pinhole" is used to describe a failure mode distinct from delamination. Delamination is intended to indicate adhesive failure, while "pinhole" does not. "Pinhole" is used to identify the result of a scrubbing / flexural abrasion test, specifically small or microscopic holes that can be observed (under light) in the coated fabric. These pinholes are typically caused by warp-weft misalignment in the woven fabric, rather than adhesive failure.

[0269] Table 5a: Flexural abrasion results (reciprocating) obtained on 420 dp PA66 fabric according to ISO 5981 Test Method A) (Number of friction cycles) — Analysis of meridional, zonal, and failure modes

[0270]

[0271] Table 5b: Test method A according to ISO 5981 on 420 dtex PA66 fabric and 550 dtex PET airbag fabric. The obtained flexural wear results (number of reciprocating friction cycles) – analysis of the warp, weft, and failure modes respectively.

[0272]

[0273] It should be noted that all embodiments meet the required criteria of more than 600 times or more.

[0274] Therefore, in summary, the examples demonstrate that the compositions described herein containing component (e) as an adhesion promoter exhibit superior flowability, mechanical strength, improved adhesion to woven fabrics, and lower total volatile organic compound (TVOC) content compared to conventional airbag coating LSR materials using a combination of organometallic catalysts and alkoxysilanes as adhesion promoters.

[0275] It was found that the viscosity of the injection-molded composition was too high to form a coating, and its adhesion to fabrics was weak, believed to be due to poor wettability to textile and / or fabric substrate surfaces. In contrast, as noted above, the examples provide superior airbag coatings with good adhesion and excellent TVOC results.

Claims

1. A silicone rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics, said silicone rubber coating composition capable of hydrogenation and silanization curing comprising: a) An organopolysiloxane polymer having a viscosity at 25°C between 100 mPa·s and 200,000 mPa·s, including the end values, and having at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl or alkynyl groups; b) Optional reinforcing filler, said reinforcing filler comprising pyrolytic silica, precipitated silica, or mixtures thereof; c) An organosilicon compound having at least two, alternatively at least three, Si-H groups per molecule and not containing a biphenyl unit; d) Hydrogenated silane curing catalyst; e) An adhesion promoter comprising an organosilicon bisphenol adduct compound, the organosilicon bisphenol adduct compound comprising a biphenyl unit not directly bonded to a silicon atom, and at least one Si-H group, and optionally... f) One or more silicone resins, wherein the silicone resin is selected from T silicone resin (sesquioxane), DT silicone resin, MQ silicone resin, MDT silicone resin, MTQ silicone resin, QDT silicone resin or mixtures thereof.

2. The organosilicon rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics according to claim 1, wherein the biphenyl unit of the organosilicon bisphenol adduct compound in component (e) has the following structure At least one H on one or both aromatic rings can be replaced by another group, and -X 2 - is a methylene bridge, selected from -C(CH3)2-, -C(Ph)(CH3)-, -C(Ph)2, -C(CF3)2-, -C(CH3)(C2H5)-, -C(CH2)5-, -C(CH3)(H)-, or -C(H)2-, where Ph is a phenyl group.

3. The organosilicon rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics according to claim 1 or 2, wherein the organosilicon bisphenol adduct compound in component (e) has the following structure: Where X 2 As defined above, Z 3 It is an alkylene group having 2 to 6 carbon atoms, alternatively 2 to 5 carbon atoms, alternatively 2 to 4 carbon atoms, and alternatively an ethylene or propylene group; R 15 It has the structure -(CH3)SiO-(R 14 H SiO) d Cyclic siloxanes; R 16 It has a structure (OSiR) 14 H) d -OSi(CH3)- cyclic siloxanes; R 14 It is an alkyl group having 1 to 6 carbon atoms, and d is an integer from 2 to 7; or it is an oligomer of d.

4. The organosilicon rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics according to claim 3, wherein the organosilicon bisphenol adduct compound in component (e) has the following structure Where n is an integer from 1 to 5.

5. The organosilicon rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics according to claim 3 or 4, wherein the organosilicon bisphenol adduct compound in component (e) has the following structure 。 6. The organosilicon rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics according to claim 1 or 2, wherein the organosilicon bisphenol adduct compound in component (e) has one of the following structures or the structure of an oligomer thereof. Z 3 R 15 R 16 and X 2 As mentioned above R 17 It is -Si(CH3)3, -Z 4 R 20 Or -(O=)CCH3, R 18 It is (CH3)Si-, R 20 Z 4 -or CH3C(=O)-, R 20 It is an epoxide group, and Z 4 It is an alkylene group having 2 to 6 carbon atoms. or Where R 18 X 2 Z 3 and R 15 All are as defined above; or Where R 18 X 2 Z 3 R 16 and R 15 All are as defined above.

7. The organosilicon rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics according to claim 1, wherein the organosilicon rubber coating composition capable of hydrogenation and silanization curing has a structure comprising an intermediate cyclic siloxane (Y... 2 ) Where X 2 Z 3 R 16 and R 15 All are as defined above; and Y 2 It has the structure -(CH3)SiO-(R 17 H SiO) e -OSi(CH3)- cyclic siloxanes.

8. A silicone rubber coating composition capable of hydrogenation and silanization curing for treating textiles and fabrics according to any one of claims 1 to 7, wherein the silicone rubber coating composition capable of hydrogenation and silanization curing further comprises one or more flame retardants selected from precipitated calcium carbonate, aluminum trihydrate, magnesium dihydroxide, a mixture of magnesia and calcium carbide, chlorinated paraffin, hexabromocyclododecane, triphenyl phosphate, dimethyl methylphosphonate, tris(2,3-dibromopropyl) phosphate, and mixtures thereof.

9. The organosilicon coating composition capable of hydrogenation silanization curing according to any one of claims 1 to 8, wherein component (f) is one or more MQ resins containing unsaturated groups, said unsaturated groups being selected from alkenyl groups, alkynyl groups, or a mixture of alkenyl and alkynyl groups.

10. A coated textile material comprising a textile material coated with a cured product of a silicone rubber coating composition capable of hydrogenation and silanization curing according to any one of claims 1 to 9.

11. The coated textile material of claim 10, wherein the textile material is a woven or nonwoven fabric made of synthetic fibers or a blend of natural and synthetic fibers.

12. The coated textile material according to claim 10 or 11, wherein the coated textile material is made of: polyamide fibers; polyester fibers; polyimide, polyethylene, polypropylene, polyester-cotton blends, polyacrylonitrile fiber fabrics, aramid fiber fabrics, polyetherimide fiber fabrics, polysulfone fiber fabrics, carbon fiber fabrics, rayon fiber fabrics, and / or glass fibers.

13. The coated textile material according to claim 10, 11 or 12, wherein the coated textile material is an airbag.

14. A method for coating a textile material with a silicone rubber coating composition capable of hydrogenation and silanization curing according to claim 10, 11, 12 or 13, the method comprising the following steps: The components of the organosilicon rubber coating composition capable of hydrogenation and silanization curing according to any one of claims 1 to 9 are mixed, the organosilicon rubber coating composition capable of hydrogenation and silanization curing is applied to the surface of a textile, and the composition is cured to form a coated textile material.

15. Use of an organosilicon bisphenol adduct compound as an adhesion promoter in a hydrogen silanization-curable organosilicon rubber coating composition for treating textiles and fabrics, said organosilicon bisphenol adduct compound comprising a biphenyl unit not directly bonded to a silicon atom, and at least one Si-H group; said hydrogen silanization-curable organosilicon rubber coating composition further comprising: a) An organopolysiloxane polymer having a viscosity at 25°C between 100 mPa·s and 200,000 mPa·s, including the end values, and having at least two unsaturated groups per molecule, the unsaturated groups being selected from alkenyl or alkynyl groups; b) Optional reinforcing filler, said reinforcing filler comprising pyrolytic silica, precipitated silica, or mixtures thereof; c) An organosilicon compound having at least two, alternatively at least three Si-H groups per molecule and not containing a biphenyl unit; d) Hydrogenated silane curing catalyst; And optional f) One or more silicone resins, wherein the silicone resin is selected from T silicone resin (sesquioxane), DT silicone resin, MQ silicone resin, MDT silicone resin, MTQ silicone resin, QDT silicone resin or mixtures thereof.

16. Use of the organosilicon bisphenol adduct compound according to claim 15, wherein the biphenyl unit of the organosilicon bisphenol adduct compound in component (e) has the following structure At least one H on one or both aromatic rings can be replaced by another group, and -X 2 - is a methylene bridge, selected from -C(CH3)2-, -C(Ph)(CH3)-, -C(Ph)2, -C(CF3)2-, -C(CH3)(C2H5)-, -C(CH2)5-, -C(CH3)(H)-, or -C(H)2-, where Ph is a phenyl group.

17. Use of the organosilicon bisphenol adduct compound according to claim 15 or 16, wherein the organosilicon bisphenol adduct compound has a structure as defined in any one of claims 3 to 7.

18. Use of the coated material according to any one of claims 10, 11 or 12 as an airbag.

Images