Liquid addition-curable silicone rubber composition for airbags, and airbag

Abstract

The present invention pertains to a liquid addition-curable silicone rubber composition for airbags, the composition comprising: (A) a linear organopolysiloxane having a polymerization degree of 50-2,000 and including an alkenyl group bonded to two or more silicon atoms in one molecule; (B) a powdery three-dimensional network organopolysiloxane resin; (C) a linear organohydrogenpolysiloxane in which terminals are blocked with a trialkylsilyl group and which includes two or more hydrosilyl groups in one molecule; (D) a silica fine powder; (E) a surface treatment agent selected from silazanes or chlorosilanes; (F) a hydrosilylation reaction catalyst; (G) an organic silicon compound including an adhesiveness-imparting functional group; and (H) a titanium or zirconium compound including one or more ligands represented by formula (1). As a result, provided are: a liquid addition-curable silicone rubber composition for airbags, the composition having excellent sliding detachment resistance and storage stability; and an airbag having a cured coating made of said composition.

Description

Addition-curable liquid silicone rubber composition for airbags and airbags

[0001] The present invention relates to an addition-curable liquid silicone rubber composition for airbags and to an airbag.

[0002] Conventionally, airbags coated with silicone rubber have excellent internal pressure retention and low combustion rate, making them suitable for use in automobiles and other vehicles. One example of a silicone rubber composition for airbags is disclosed in Patent Document 1, which uses a crosslinking agent consisting of an organohydrogenpolysiloxane containing one or more hydrosilyl groups at sites other than both ends of the molecular chain and an organohydrogenpolysiloxane containing silicon-bonded hydrogen atoms only at both ends of the molecular chain. Airbags coated with this composition are characterized by excellent adhesion to base fabrics, particularly after wet heat treatment. However, the hydrosilyl groups at the molecular chain ends are highly reactive, and decompose with silanols contained in reinforcing silica during long-term storage, raising concerns about poor storage stability. Another example is a silicone rubber composition containing a blocked polyisocyanate (Patent Document 2). Airbags coated with this composition are characterized by excellent adhesion to base fabrics. However, when a silicone rubber composition containing a highly polar additive such as a blocked polyisocyanate is stored for a long period of time, the viscosity increases, which may lead to a deterioration in workability.

[0003] Furthermore, in recent years, the coating weight of addition-curable liquid silicone rubber compositions for airbags has been reduced in order to save space and reduce weight, and there is a need for an addition-curable liquid silicone rubber composition for airbags that will not burst due to the pressure of the inflator gas when the airbag is deployed, even with a low coating weight. To prevent airbags from bursting due to the pressure of the inflator gas, slip resistance, which is an indicator of the strength of the silicone-coated base fabric, is considered to be important. However, there is little literature that discusses the effect of silicone coating agents on the strength of the silicone-coated base fabric.

[0004] As a silicone rubber composition that produces a high-strength silicone-coated airbag fabric, a composition has been disclosed in which an addition-curing silicone rubber composition is blended with an organosilicon compound containing six or more alkoxy groups directly bonded to silicon atoms per molecule (Patent Document 3). Silicone-coated fabrics coated with this composition are characterized by excellent slippage resistance. Another composition has been disclosed in which an organic compound containing at least one ether bond per molecule but no adhesion-imparting functional group is blended with a silicone rubber composition (Patent Document 4). Silicone-coated fabrics coated with this composition are characterized by low burn rates and excellent tear strength. However, these compositions require the blending of organosilicon compounds containing condensable silylalkoxy groups or compounds with highly polar ether bonds, which raises concerns that the viscosity of the silicone rubber composition increases during long-term storage, resulting in poor coating workability.

[0005] JP 2018-76394 A, JP 2019-6952 A, JP 2023-152553 A, JP 2022-030018 A

[0006] The present invention has been made in light of the above circumstances, and has as its object to provide an addition-curable liquid silicone rubber composition for air bags that exhibits excellent slip resistance and storage stability, and an air bag having a cured coating of said composition.

[0007] In order to solve the above problems, the present invention provides an addition-curable liquid silicone rubber composition for airbags, comprising: (A) 100 parts by mass of a linear organopolysiloxane containing two or more silicon-bonded alkenyl groups per molecule and having a weight-average degree of polymerization of 50 to 2,000; (B) 0.1 to 100 parts by mass of a powdery three-dimensional network organopolysiloxane resin; (C) a linear organohydrogenpolysiloxane whose ends are capped with trialkylsilyl groups and containing two or more hydrosilyl groups per molecule, in an amount such that the total number of hydrosilyl groups contained in the composition is 1 to 10 moles per mole of silicon-bonded alkenyl groups; and (D) a BET specific surface area of ​​50 m. ２ / g or more: 1 to 50 parts by mass, (E) a surface treatment agent selected from silazanes or chlorosilanes: 10 to 60 parts by mass per 100 parts by mass of the silica fine powder of component (D), (F) a hydrosilylation reaction catalyst: 1 to 500 ppm in terms of the mass of catalytic metal element relative to the total mass of components (A) to (D), (G) an organosilicon compound containing an adhesion-imparting functional group: 0.1 to 10 parts by mass, (H) a titanium or zirconium compound containing one or more ligands represented by the following formula (1): (wherein * indicates a bond to a metal atom, and R １ each independently represents a hydrocarbon group having 1 to 10 carbon atoms.

[0008] Such an addition-curable liquid silicone rubber composition for air bags has excellent storage stability, and the silicone-coated air bag fabric having a cured coating thereof has excellent slippage resistance.

[0009] Furthermore, in the present invention, the component (H) is preferably diisopropoxybis(ethylacetoacetate)titanium or dibutoxybis(ethylacetoacetate)zirconium.

[0010] Such an addition-curable liquid silicone rubber composition for air bags reliably exhibits excellent storage stability, and the silicone-coated air bag fabric having a cured coating thereof exhibits excellent slippage resistance.

[0011] Furthermore, in the present invention, the component (G) is preferably an organosilicon compound having, in one molecule, one or more reactive silyl groups selected from an alkoxysilyl group, an alkenyl-containing silyl group, and a hydrosilyl group, and one or more reactive organic groups selected from an epoxy group, an isocyanate group, and a (meth)acrylic group.

[0012] Such an addition-curable liquid silicone rubber composition for air bags provides superior adhesion of the silicone rubber layer to the air bag fabric.

[0013] Furthermore, in the present invention, the component (E) is preferably hexamethyldisilazane or 1,3-divinyl-1,1,3,3-tetramethyldisilazane.

[0014] Such an addition-curable liquid silicone rubber composition for air bags has a low viscosity and is excellent in coating workability.

[0015] The present invention also provides an air bag having a cured coating of the above-described addition-curable liquid silicone rubber composition for air bags on an air bag base fabric.

[0016] Such an air bag has excellent resistance to slipping off.

[0017] As described above, according to the present invention, an airbag fabric having excellent resistance to slippage and high strength can be provided by coating an airbag fabric with a predetermined silicone rubber composition and curing the composition. Furthermore, this silicone rubber composition can suppress an increase in viscosity even when stored for a long period of time, and has excellent storage stability.

[0018] As described above, there has been a need for an addition-curable liquid silicone rubber composition for air bags that exhibits excellent slip resistance and storage stability, as well as the development of high-strength air bags having a cured coating of such a composition.

[0019] As a result of extensive research into the above-mentioned problems, the present inventors discovered that an addition-curable liquid silicone rubber composition for airbags containing an appropriate amount of a titanium or zirconium compound containing a ligand represented by formula (1) can be coated onto an airbag fabric and cured to provide a coated fabric with excellent slip resistance, leading to the completion of the present invention.

[0020] That is, the present invention provides an addition-curable liquid silicone rubber composition for air bags, comprising: (A) 100 parts by mass of a linear organopolysiloxane having a weight average degree of polymerization of 50 to 2,000 and containing two or more silicon-bonded alkenyl groups per molecule; (B) 0.1 to 100 parts by mass of a powdery three-dimensional network organopolysiloxane resin; (C) a linear organohydrogenpolysiloxane whose terminals are capped with trialkylsilyl groups and containing two or more hydrosilyl groups per molecule, in an amount such that the total number of hydrosilyl groups contained in the composition is 1 to 10 moles per mole of silicon-bonded alkenyl groups; (D) a BET specific surface area of ​​50 m ２ / g or more: 1 to 50 parts by mass, (E) a surface treatment agent selected from silazanes or chlorosilanes: 10 to 60 parts by mass per 100 parts by mass of the silica fine powder of component (D), (F) a catalyst for hydrosilylation reaction: 1 to 500 ppm in terms of the mass of catalytic metal element per total mass of components (A) to (D), (G) an organosilicon compound containing an adhesion-imparting functional group: 0.1 to 10 parts by mass, (H) a titanium or zirconium compound containing one or more ligands represented by the following formula (1): (wherein * indicates a bond to a metal atom, and R １ each independently represents a hydrocarbon group having 1 to 10 carbon atoms.

[0021] The present invention will be described in detail below, but the present invention is not limited thereto.

[0022] In this specification, the viscosity is a value measured at 25° C. using a rotational viscometer in accordance with the method described in JIS K 7117-1: 1999. The weight-average degree of polymerization and the weight-average molecular weight are values ​​determined as polystyrene-equivalent weight-average molecular weights (weight-average degree of polymerization) by GPC (gel permeation chromatography) analysis using tetrahydrofuran (THF) as a developing solvent, measured under the following conditions:

[0023] [Measurement conditions] Developing solvent: tetrahydrofuran Flow rate: 0.35 mL / min Detector: differential refractive index detector (RI) Column: TSK Guard column Super H-L TSKgel Super H4000 (6.0 mm I.D. × 15 cm × 1) TSKgel Super H3000 (6.0 mm I.D. × 15 cm × 1) TSKgel Super H2000 (6.0 mm I.D. × 15 cm × 2) (all manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 10 μL (tetrahydrofuran solution with a concentration of 0.5 wt%)

[0024] <Addition-Curable Liquid Silicone Rubber Composition for Air Bags> The addition-curable liquid silicone rubber composition for air bags of the present invention comprises: (A) 100 parts by mass of a linear organopolysiloxane having a weight-average degree of polymerization of 50 to 2,000 and containing two or more alkenyl groups bonded to silicon atoms per molecule; (B) 0.1 to 100 parts by mass of a powdery three-dimensional network organopolysiloxane resin; (C) a linear organohydrogenpolysiloxane whose ends are capped with trialkylsilyl groups and containing two or more hydrosilyl groups per molecule; (D) a BET specific surface area of ​​50 m ２ / g or more: 1 to 50 parts by mass, (E) a surface treatment agent selected from silazanes or chlorosilanes: 10 to 60 parts by mass per 100 parts by mass of the silica fine powder of component (D), (F) a catalyst for hydrosilylation reaction: 1 to 500 ppm, calculated as the mass of the catalytic metal element, based on the total mass of components (A) to (D), (G) an organosilicon compound containing an adhesion-imparting functional group: 0.1 to 10 parts by mass, (H) a titanium or zirconium compound containing one or more ligands represented by the following formula (1): (wherein * indicates a bond to a metal atom, and R １ each independently represents a hydrocarbon group having 1 to 10 carbon atoms.

[0025] Each component will be described in detail below.

[0026] [Component (A)] In the present invention, the linear organopolysiloxane of component (A) is an organopolysiloxane that contains two or more silicon-bonded alkenyl groups per molecule and has a weight-average degree of polymerization of 50 to 2,000, and is the base polymer (main component) of the addition-curable liquid silicone rubber composition for airbags according to the present invention.

[0027] The molecular structure of component (A) is also characterized by being linear. Among these, diorganopolysiloxanes whose main chain is essentially composed of repeating diorganosiloxane units and whose molecular chain ends are blocked with triorganosiloxy groups are preferred. Furthermore, the position of the silicon atom to which the alkenyl group is bonded in the linear organopolysiloxane molecule of component (A) may be either at the molecular chain end (i.e., triorganosiloxy group) or in the molecular chain (i.e., bifunctional diorganosiloxane units located at non-terminal positions), or both. A particularly preferred component (A) is a linear diorganopolysiloxane containing alkenyl groups bonded to silicon atoms at at least both molecular chain ends.

[0028] The alkenyl group bonded to a silicon atom in component (A) typically contains 2 to 8 carbon atoms, and preferably 2 to 4 carbon atoms. Specific examples include vinyl, allyl, propenyl, butenyl, pentenyl, hexenyl, cyclohexenyl, and heptenyl groups, with vinyl groups being particularly preferred.

[0029] The number of alkenyl groups bonded to silicon atoms in component (A) is two or more per molecule, preferably 2 to 100, and more preferably 2 to 50.

[0030] Examples of the monovalent hydrocarbon group bonded to a silicon atom other than an alkenyl group in component (A) include monovalent hydrocarbon groups typically having 1 to 12 carbon atoms, and preferably 1 to 10 carbon atoms. Specific examples of monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, and heptyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; and aralkyl groups such as benzyl and phenethyl. Groups in which some of the hydrogen atoms of these substituents have been substituted with halogen atoms such as fluorine atoms may also be used. Of these, methyl groups are preferred.

[0031] The weight-average degree of polymerization of component (A) is 50 to 2,000, preferably 100 to 1,500, and more preferably 120 to 1,000. If the weight-average degree of polymerization is less than 50, the mechanical properties of the resulting silicone rubber coating may deteriorate, while if the weight-average degree of polymerization is greater than 2,000, the viscosity of the resulting composition may increase, worsening coating workability.

[0032] The viscosity of component (A) at 25° C. is preferably 50 to 200,000 mPa·s, more preferably 100 to 150,000 mPa·s, and even more preferably 400 to 100,000 mPa·s. If the viscosity of component (A) is 50 mPa·s or higher, the mechanical properties of the resulting silicone rubber coating will be good, and if it is 200,000 mPa·s or lower, the viscosity of the resulting composition will not be too high, and coating workability will also be favorable.

[0033] Specific examples of organopolysiloxanes of component (A) include dimethylsiloxane-methylvinylsiloxane copolymers capped at both molecular chain terminals with trimethylsiloxy groups, methylvinylpolysiloxanes capped at both molecular chain terminals with trimethylsiloxy groups, dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers capped at both molecular chain terminals with trimethylsiloxy groups, dimethylpolysiloxanes capped at both molecular chain terminals with dimethylvinylsiloxy groups, methylvinylpolysiloxanes capped at both molecular chain terminals with dimethylvinylsiloxy groups, and dimethylsiloxane-methylvinylpolysiloxanes capped at both molecular chain terminals with dimethylvinylsiloxy groups. and mixtures of two or more of these organopolysiloxanes.

[0034] The organopolysiloxane of component (A) may use either a single compound, or a combination of two or more different compounds.

[0035] [Component (B)] The powdery three-dimensional network organopolysiloxane resin of component (B) (provided that the organopolysiloxane resin does not contain hydrosilyl groups) acts as a flame retardancy improver. Component (B) preferably contains a trifunctional R ２ SiO ３／２ units and tetrafunctional SiO ４／２ The siloxane unit may be a monofunctional R ２ ３ SiO １／２ units and / or bifunctional R ２ ２ SiO ２／２However, this organopolysiloxane resin does not contain hydrosilyl groups (hydrogen atoms bonded to silicon atoms) in the molecule. Furthermore, this organopolysiloxane resin has a three-dimensional network (resinous) structure and is in powder form at 25°C, so it is clearly distinguishable from the aforementioned component (A), which has a linear structure.

[0036] The above R ２ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and examples thereof include the same alkenyl groups and monovalent hydrocarbon groups as exemplified for component (A) above. Specific examples include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, and heptyl; alkenyl groups such as vinyl, allyl, propenyl, butenyl, pentenyl, hexenyl, cyclohexenyl, and heptenyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; and aralkyl groups such as benzyl and phenethyl. Groups in which some of the hydrogen atoms of these substituents have been substituted with halogen atoms, such as fluorine atoms, may also be used. Of these, methyl and vinyl groups are preferred.

[0037] The content of silicon-bonded alkenyl groups in component (B) is preferably 0 to 10 mol %, and more preferably 2 to 8 mol %, based on the total number of silicon-bonded substituents.

[0038] The organopolysiloxane resin of component (B) is formed by the addition of R ２ SiO ３／２ Units and SiO ４／２ The total amount of siloxane units in the organopolysiloxane resin of component (B) is preferably 20 to 75 mol %, and more preferably 30 to 65 mol %. A content within this range is preferred because it provides sufficient flame retardancy improvement.

[0039] As described above, the organopolysiloxane resin of component (B) contains R ２ ３ SiO １／２ Units and / or R ２２ SiO ２／２ The total content of these units in the organopolysiloxane resin of component (B) is preferably 0 to 70 mol %, and more preferably 0 to 50 mol %.

[0040] The weight-average molecular weight of the organopolysiloxane resin of component (B) is preferably in the range of 2,000 to 50,000, and particularly preferably 4,000 to 20,000. If the weight-average molecular weight is in the range of 2,000 to 50,000, sufficient flame retardancy can be achieved and the viscosity will be favorable for coating workability.

[0041] Specific examples of the organopolysiloxane resin of component (B) include those represented by the formula: R' ３ SiO １／２ and a siloxane unit represented by the formula: R' ２ R″SiO １／２ and a siloxane unit represented by the formula: R' ２ SiO ２／２ and a siloxane unit represented by the formula: SiO ４／２ and an organosiloxane copolymer comprising a siloxane unit represented by the formula: R' ３ SiO １／２ and a siloxane unit represented by the formula: R' ２ R″SiO １／２ and a siloxane unit represented by the formula: SiO ４／２ and an organosiloxane copolymer comprising a siloxane unit represented by the formula: R' ２ R″SiO １／２ and a siloxane unit represented by the formula: R' ２ SiO ２／２ and a siloxane unit represented by the formula: SiO ４／２ and an organosiloxane copolymer having a siloxane unit represented by the formula: R'R"SiO ２／２ and a siloxane unit represented by the formula: R'SiO ３／２ or a siloxane unit represented by the formula: R″SiO ３／２ and a mixture of two or more of these organopolysiloxanes.

[0042] R' in the above formula is independently a group selected from an alkyl group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms, preferably 7 or 8 carbon atoms. Examples of such groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, and heptyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; and halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl, with methyl being particularly preferred. R" in the above formula is an alkenyl group having 2 to 10 carbon atoms, preferably 2 to 8 carbon atoms. Examples of such groups include vinyl, allyl, butenyl, pentenyl, hexenyl, and heptenyl, with vinyl being particularly preferred.

[0043] The blending amount of component (B) is 0.1 to 100 parts by mass, preferably 3 to 75 parts by mass, and particularly preferably 5 to 60 parts by mass, per 100 parts by mass of the organopolysiloxane of component (A). A blending amount within the range of 0.1 to 100 parts by mass provides sufficient flame retardancy improvement and is excellent in cost effectiveness.

[0044] The three-dimensional network organopolysiloxane resin of component (B) can use either a single material or a combination of two or more different materials.

[0045] [Component (C)] Component (C) is a linear organohydrogenpolysiloxane whose terminals are capped with trialkylsilyl groups and which contains two or more hydrosilyl groups per molecule, and which acts as a crosslinking agent for the present composition.

[0046] The organohydrogenpolysiloxane of component (C) has a linear molecular structure and does not contain hydrosilyl groups as terminal groups. It is preferable to use one that is liquid at 25°C and has 2 to 300 silicon atoms (or a weight-average degree of polymerization) per molecule, and is particularly preferably 3 to 200. The number of hydrosilyl groups per molecule is two or more, preferably 2 to 200, more preferably 3 to 150, and even more preferably 3 to 100.

[0047] Examples of the substituent bonded to the silicon atom of component (C) include monovalent hydrocarbon groups typically having 1 to 12 carbon atoms, and preferably 1 to 10 carbon atoms. Specific examples of monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, and heptyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; and aralkyl groups such as benzyl and phenethyl. Groups in which some of the hydrogen atoms of these substituents have been substituted with halogen atoms such as fluorine atoms may also be used. Of these, methyl and phenyl groups are preferred.

[0048] Examples of such organohydrogenpolysiloxanes include methylhydrogenpolysiloxanes capped at both ends with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymers capped at both ends with trimethylsiloxy groups, methylhydrogensiloxane-diphenylsiloxane copolymers capped at both ends with trimethylsiloxy groups, methylhydrogensiloxane-diphenylsiloxane-dimethylsiloxane copolymers capped at both ends with trimethylsiloxy groups, and the above-mentioned exemplary compounds in which some or all of the methyl groups have been substituted with other alkyl groups such as ethyl groups or propyl groups, or aryl groups such as phenyl groups. Specific examples of such organohydrogenpolysiloxanes include compounds of the following formula (2):

[0049] (In the formula, R ３ , R ４ are independently a hydrocarbon group having 1 to 10 carbon atoms, a is an integer of 0 to 300, b is an integer of 2 to 300, and a+b is an integer of 2 to 300.

[0050] The organohydrogenpolysiloxane preferably has a viscosity at 25°C of 0.5 to 10,000 mPa·s, and more preferably 1 to 300 mPa·s.

[0051] The amount of component (C) to be blended is an amount such that the total number of hydrosilyl groups contained in the composition of the present invention is 1 to 10 moles, preferably 1.2 to 9 moles (or groups), and more preferably 1.5 to 8 moles (or groups), per mole of the total number of silicon-bonded alkenyl groups contained in the composition of the present invention. If the total number of hydrosilyl groups contained in the composition containing component (C) is less than 1 mole per mole of the total number of silicon-bonded alkenyl groups contained in the composition, the addition-curable liquid silicone rubber composition for air bags will not cure sufficiently, and if this number exceeds 10 moles, the heat resistance of the cured silicone rubber obtained from the addition-curable liquid silicone rubber composition for air bags may be extremely poor.

[0052] More specifically, for example, the amount of hydrosilyl groups contained in component (C) can be 1 to 10 moles per combined mole of silicon-bonded alkenyl groups contained in components (A), (B), and (F).

[0053] The organohydrogenpolysiloxane of component (C) may use either a single compound, or a combination of two or more different compounds.

[0054] [Component (D)] Component (D) has a BET specific surface area of ​​50 m ２ / g or more acts as a reinforcing filler, imparting strength to the cured silicone rubber obtained from the addition-cure liquid silicone rubber composition for air bags of the present invention, and by using silica fine powder as a reinforcing filler, it is possible to form a coating film that satisfies the strength required for the present invention.

[0055] The silica fine powder has a specific surface area of ​​50 m2 as measured by the BET method. ２ / g or more, preferably 50 to 400m ２ / g, more preferably 100 to 300 m ２ / g. The specific surface area can be 50 m ２ If the viscosity is less than 1 / g, it is not possible to impart sufficient mechanical strength properties for use as a coating agent for an air bag.

[0056] Such silica fine powder may be any known type that has conventionally been used as a reinforcing filler for cured silicone rubber, provided that its specific surface area falls within the above-mentioned range, such as fumed silica and precipitated silica (wet silica).

[0057] The blending amount of component (D) is 1 to 50 parts by mass, preferably 3 to 40 parts by mass, and more preferably 5 to 30 parts by mass, per 100 parts by mass of the organopolysiloxane of component (A). If the blending amount is less than 1 part by mass, a silicone rubber cured product with sufficient strength will not be obtained, while if the blending amount exceeds 50 parts by mass, the viscosity of the resulting addition-curable liquid silicone rubber composition for air bags will increase, reducing flowability and potentially making the coating process difficult.

[0058] The fine silica powder of component (D) may be used alone or in combination of two or more different types.

[0059] [Component (E)] Component (E) is a surface treatment agent selected from silazanes or chlorosilanes, which hydrophobizes the silica fine powder (component (D)) by reacting with silanol groups present on the surface of the silica fine powder. The hydrophobization of the silica fine powder improves its compatibility with other components.

[0060] Specific examples of the surface treatment agent for component (E) include silazanes such as hexamethyldisilazane, (dimethylamino)trimethylsilane, and tetramethyldivinylsilazane, and chlorosilanes such as trimethylchlorosilane, dimethylvinylchlorosilane, dimethyldichlorosilane, and methyltrichlorosilane. These can be used to perform surface treatment and produce hydrophobic silica fine powders. Particularly preferred surface treatment agents are hexamethyldisilazane and tetramethyldivinylsilazane (particularly 1,3-divinyl-1,1,3,3-tetramethyldisilazane).

[0061] The surface treatment agent of component (E) may be one which has been subjected to a surface hydrophobic treatment directly with the silica fine powder of component (D) in powder form in advance, or one which has been subjected to a surface hydrophobic treatment by adding the surface treatment agent of component (E) when kneading the silicone oil (for example, the alkenyl group-containing organopolysiloxane of component (A) in oil form) with the silica fine powder of component (D).

[0062] Known techniques can be used for the surface treatment. For example, the untreated silica fine powder and the surface treatment agent can be placed in a mechanical mixer or fluidized bed apparatus sealed at atmospheric pressure, and kneaded at room temperature (25°C) or under heat treatment (heating) in the presence of an inert gas, if necessary. In some cases, water or a catalyst (such as a hydrolysis promoter) can be used to promote the surface treatment. After kneading, the mixture is dried to produce a surface-treated silica fine powder.

[0063] When the surface treatment agent for component (E) contains alkenyl groups and has been directly surface-hydrophobized, the amount of hydrosilyl groups contained in the composition containing component (C) is preferably 1 to 10 moles (or groups), more preferably 1.2 to 8 moles (or groups), and even more preferably 1.5 to 6 moles (or groups), per 1 mole (or groups) of alkenyl groups bonded to silicon atoms contained in the composition containing the surface treatment agents for components (A), (B), and (E).

[0064] This is because if there are less than 1 mole of hydrosilyl groups per mole of alkenyl groups bonded to silicon atoms in the addition-curable liquid silicone rubber composition for air bags, the addition-curable liquid silicone rubber composition for air bags will not cure sufficiently and may not exhibit sufficient adhesive strength, whereas if there are more than 10 moles of hydrosilyl groups, the heat resistance of the cured silicone rubber obtained from the addition-curable liquid silicone rubber composition for air bags may be significantly reduced.

[0065] The blending amount of component (E) is 10 to 60 parts by mass, preferably 12 to 55 parts by mass, and more preferably 15 to 50 parts by mass, per 100 parts by mass of the fine silica powder of component (D). If the blending amount is less than 10 parts by mass, the fine silica powder will not be sufficiently surface-treated, and the viscosity of the silicone rubber composition may increase. If the blending amount exceeds 60 parts by mass, the cost will increase and this will be uneconomical.

[0066] The surface treatment agent of the component (E) may be used alone or in combination of two or more different types.

[0067] [Component (F)] The hydrosilylation catalyst of component (F) primarily promotes the addition reaction between silicon-bonded alkenyl groups in components (A) and (B) and hydrosilyl groups in component (C). This hydrosilylation catalyst is not particularly limited, and examples include platinum group metals such as platinum, palladium, and rhodium; chloroplatinic acid; alcohol-modified chloroplatinic acid; coordination compounds of chloroplatinic acid with olefins, vinylsiloxanes, or acetylene compounds; and platinum group metal compounds such as tetrakis(triphenylphosphine)palladium and chlorotris(triphenylphosphine)rhodium, with platinum group metal compounds being preferred.

[0068] The blending amount of component (F), calculated as the mass of the catalytic metal element relative to the total mass of components (A) to (D), is 1 to 500 ppm, preferably 5 to 100 ppm. A blending amount of less than 1 ppm is undesirable because it significantly slows the addition reaction or prevents the addition-curable liquid silicone rubber composition for air bags from curing, while a blending amount of more than 500 ppm may result in a decrease in the heat resistance of the cured silicone rubber.

[0069] The hydrosilylation catalyst of component (F) may use either a single compound, or a combination of two or more different compounds.

[0070] [Component (G)] Component (G) is an organosilicon compound having an adhesion-imparting functional group, and is added to the addition-curable liquid silicone rubber composition for airbags to exhibit and improve adhesion to the airbag fabric.

[0071] Component (G) is preferably an organosilicon compound having, in one molecule, one or more functional groups selected from an epoxy group, an isocyanate group, a (meth)acrylic group, and a cyclic isocyanurate group, and one or more functional groups selected from a hydrosilyl group, an alkoxysilyl group, an alkenyl-containing silyl group, a hydroxysilyl group, and a vinyl group. It is particularly preferably an organosilicon compound having, in one molecule, one or more reactive silyl groups selected from an alkoxysilyl group, an alkenyl-containing silyl group, and a hydrosilyl group, and one or more reactive organic groups selected from an epoxy group, an isocyanate group, and a (meth)acrylic group.

[0072] Examples of the epoxy group include glycidoxyalkyl groups such as a glycidoxypropyl group, and epoxy group-containing cyclohexylalkyl groups such as a 2,3-epoxycyclohexylethyl group and a 3,4-epoxycyclohexylethyl group. Examples of the hydrosilyl group include monofunctional R ５ ２ HSiO １／２ , bifunctional R ５ HSiO ２／２ , trifunctional HSiO ３／２ and the like. More specifically, monofunctional dimethylhydrosilyl group, methylphenylhydrosilyl group, diphenylhydrosilyl group, bifunctional methylhydrosilyl group, phenylhydrosilyl group, etc. are mentioned. Examples of the alkoxysilyl group include trialkoxysilyl groups such as trimethoxysilyl group and triethoxysilyl group; alkyldialkoxysilyl groups such as methyldimethoxysilyl group, ethyldimethoxysilyl group, methyldiethoxysilyl group, ethyldiethoxysilyl group, etc. Examples of the hydroxysilyl group include monofunctional R ５ ２ (HO)SiO １／２ , bifunctional R ５ (HO)SiO ２／２ , trifunctional (HO)SiO ３／２More specifically, examples of the vinyl group include a monofunctional dimethylhydroxysilyl group, a methylphenylhydroxysilyl group, a diphenylhydroxysilyl group, and a bifunctional methylhydroxysilyl group, a phenylhydroxysilyl group, etc. ５ ２ (CH ２ =CH)SiO １／２ , bifunctional R ５ (CH ２ =CH)SiO ２／２ , trifunctional (CH ２ =CH)SiO ３／２ More specifically, monofunctional dimethylvinylsilyl groups, methylphenylvinylsilyl groups, diphenylvinylsilyl groups, and bifunctional methylvinylsilyl groups, phenylvinylsilyl groups, etc. are listed. ５ represents a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0073] Examples of the organosilicon compound of component (G) include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, (3,4-epoxycyclohexylethyl)trimethoxysilane, (3,4-epoxycyclohexylethyl)triethoxysilane, (3,4-epoxycyclohexylethyl)methyldimethoxysilane, (3,4-epoxycyclohexylethyl)methyldiethoxysilane, (2,3-epoxycyclohexylethyl)triethoxysilane, (2,3-epoxycyclohexylethyl)triethoxysilane, Examples of the silane coupling agent include epoxy group-containing silane coupling agents (i.e., epoxy functional group-containing organoalkoxysilanes) such as (2,3-epoxycyclohexylethyl)methyldimethoxysilane and (2,3-epoxycyclohexylethyl)methyldiethoxysilane, (meth)acrylic group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane, and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane and 3-isocyanatepropyltrimethoxysilane.

[0074] The main ones are listed below as examples.

[0075]

[0076] The blending amount of component (G) is 0.1 to 10 parts by mass, preferably 0.15 to 5 parts by mass, per 100 parts by mass of the organopolysiloxane of component (A). If the blending amount is less than 0.1 part by mass, the resulting addition-curable liquid silicone rubber composition for air bags may not exhibit sufficient adhesive strength. If the blending amount exceeds 10 parts by mass, the addition-curable liquid silicone rubber composition for air bags may become highly thixotropic, reducing fluidity and worsening coating workability.

[0077] When component (G) contains alkenyl groups and / or hydrosilyl groups, for example, the amount is such that the total number of hydrosilyl groups contained in the composition containing components (C) and (F) is 1 to 10 moles (or groups), preferably 1.2 to 8 moles (or groups), and more preferably 1.5 to 6 moles (or groups), per 1 mole (or groups) of silicon-bonded alkenyl groups contained in the composition containing components (A), (B), (E), and (G).

[0078] This is because if there are less than 1 mole of hydrosilyl groups per mole of alkenyl groups bonded to silicon atoms in the addition-curable liquid silicone rubber composition for air bags, the addition-curable liquid silicone rubber composition for air bags will not cure sufficiently and may not exhibit sufficient adhesive strength, whereas if there are more than 10 moles of hydrosilyl groups, the heat resistance of the cured silicone rubber obtained from the addition-curable liquid silicone rubber composition for air bags may be extremely poor.

[0079] The component (G) may use one type alone, or two or more types in combination.

[0080] [Component (H)] Component (H) is a titanium or zirconium complex (compound) containing one or more ligands of the following formula (1), and acts as a strength imparting agent for the silicone-coated base fabric. (wherein * indicates a bond to a metal atom, and R １ each independently represents a hydrocarbon group having 1 to 10 carbon atoms.

[0081] R １Specific examples of each independently include alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, isopropyl, butyl, and 2-ethylhexyl, and aryl groups having 6 to 10 carbon atoms, with methyl and ethyl groups being preferred.

[0082] Specific examples of the compound of formula (1) include methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, 2-ethylhexyl acetoacetate, phenyl acetoacetate, methyl propionylacetate, ethyl propionylacetate, butyl propionylacetate, methyl butyrylacetate, ethyl butyrylacetate, butyl butyrylacetate, methyl 3-oxoheptanoate, ethyl 3-oxoheptanoate, butyl 3-oxoheptanoate, methyl benzoylacetate, ethyl benzoylacetate, and butyl benzoylacetate, with ethyl acetoacetate being preferred.

[0083] The ligands other than those represented by formula (1) in component (H) are not particularly limited, but examples include alkoxylates derived from alcohols such as methanol, ethanol, propanol, isopropanol, n-butanol, 2-ethylhexanol, and n-octanol; carboxylate groups derived from carboxylic acids such as acetic acid, butyl acid, 2-ethylhexyl acid, octylic acid, and stearic acid; alkyl groups such as methyl, ethyl, propyl, isopropyl, and butyl; and aryl groups such as phenyl. Alkoxylates are preferred.

[0084] Component (H) is preferably diisopropoxybis(ethylacetoacetate)titanium or dibutoxybis(ethylacetoacetate)zirconium.

[0085] The amount of component (H) blended per 100 parts by mass of component (A) is preferably 0.1 to 5 parts by mass, more preferably 0.15 to 4 parts by mass, and especially preferably 0.2 to 3 parts by mass. If the blending amount is outside this range of 0.1 to 5 parts by mass, it will be impossible to impart sufficient strength to the silicone-coated airbag fabric obtained from the addition-curable liquid silicone rubber composition for airbags.

[0086] The component (H) may use one type alone, or two or more types in combination.

[0087] [Other Components] In addition to the components (A) through (H) described above, other optional components can be blended into the addition-curable liquid silicone rubber composition for air bags according to the present invention, depending on the purpose. Specific examples include the following. These other components may each be used alone, or two or more may be used in combination.

[0088] [Cure Retarder] The cure retarder is not particularly limited as long as it is a compound that has a cure-inhibiting effect on the hydrosilylation catalyst of component (F), and known compounds can be used. Specific examples include phosphorus-containing compounds such as triphenylphosphine; nitrogen-containing compounds such as tributylamine, tetramethylethylenediamine, and benzotriazole; sulfur-containing compounds; acetylene-based compounds such as acetylene alcohols; compounds containing two or more alkenyl groups; hydroperoxy compounds; and maleic acid derivatives.

[0089] The degree of cure inhibition effect of a cure regulator varies depending on the chemical structure of the cure regulator, so it is preferable to adjust the amount of cure regulator added to an optimum amount for each cure regulator used. By adding an optimum amount of cure regulator, the addition-curable liquid silicone rubber composition for air bags will have excellent long-term storage stability at room temperature and curability.

[0090] [Non-reinforcing filler] Examples of fillers other than the fine silica powder of component (D) include crystalline silica (for example, a filler having a specific surface area of ​​50 m2 by the BET method). ２ / g or less quartz powder), carbon black, graphite powder, expanded graphite powder, expanded graphite powder, organic resin hollow filler, polymethylsilsesquioxane fine particles (so-called silicone resin powder), fumed titanium dioxide, magnesium oxide, zinc oxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, zinc carbonate, diatomaceous earth, talc, glass fiber, and other fillers; fillers obtained by subjecting these fillers to surface hydrophobic treatment with an organosilicon compound such as an organoalkoxysilane compound, an organochlorosilane compound, an organosilazane compound, or a low-molecular-weight siloxane compound; silicone rubber powder; and silicone resin powder.

[0091] [Other Components] In addition, for example, organopolysiloxanes containing one silicon-bonded hydrogen atom per molecule and no other functional groups, organopolysiloxanes containing one silicon-bonded alkenyl group per molecule and no other functional groups, non-functional organopolysiloxanes containing no silicon-bonded hydrogen atoms, no silicon-bonded alkenyl groups, and no other functional groups (so-called dimethylsilicone oil), organic solvents, creep-hardening inhibitors, plasticizers, thixotropy-imparting agents, pigments, dyes, anti-fungal agents, etc. may be blended.

[0092] <Preparation of addition-curable liquid silicone rubber composition for air bags> The addition-curable liquid silicone rubber composition for air bags can be prepared by uniformly mixing the above components (A) to (H) and other components that are added as needed.

[0093] The addition-curable liquid silicone rubber composition for air bags obtained in this manner is a liquid composition at 25°C, and preferably has a viscosity at 25°C of 1 to 500 Pa·s, more preferably 2 to 400 Pa·s, and even more preferably 5 to 300 Pa·s. If the viscosity is within the above range at 25°C, it is suitable for use because it is less likely to cause uneven coating or insufficient adhesion to the air bag fabric after curing when applied to the fabric.

[0094] The silicone rubber composition of the present invention can also be a two-component type. That is, components A and B can be prepared separately and then mixed together immediately before use. This can further improve the storage stability of the silicone rubber composition of the present invention. In this case, for example, components (A), (D), (E), (F), and (H) can be blended into component A, and components (A), (B), (C), (D), (E), and (G) can be blended into component B.

[0095] <Air Bag> The present invention also provides an air bag having a cured coating of the above-described addition-curable liquid silicone rubber composition for air bags on an air bag base fabric.

[0096] <Airbag Fabric> Generally, known fabrics are used as the airbag fabric (substrate made of fiber fabric) on which the silicone rubber layer is formed. Specific examples include woven fabrics of various synthetic fibers, such as various polyamide fibers such as 6,6-nylon, 6-nylon, and aramid fiber, and various polyester fibers such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT).

[0097] <Method of manufacturing an airbag> The addition-curable liquid silicone rubber composition for airbags can be applied to one or both sides, particularly just one side, of an airbag fabric (a substrate made of fiber fabric), and then heated and cured in a drying oven or the like to form a silicone rubber layer (cured coating). Airbags can be manufactured using the silicone rubber-coated fabric obtained in this way.

[0098] The addition-curable liquid silicone rubber composition for airbags can be coated onto the airbag fabric by any conventional method, but coating with a knife coater is preferred. The coating layer thickness (or surface coating amount) is typically 5 to 100 g / m ２ , preferably 8 to 90 g / m ２ , more preferably 10 to 80 g / m ２ It can be said that:

[0099] The addition-curable liquid silicone rubber composition for air bags can be cured by known curing methods under known curing conditions. Specifically, the composition can be cured by heating at 100 to 200°C for 1 to 30 minutes, for example.

[0100] When the airbag fabric (airbag silicone rubber-coated fabric) thus produced, having a silicone rubber layer on one or both sides, is processed into an airbag, it can be produced by bonding the outer peripheries of two pieces of the airbag silicone rubber-coated fabric together with an adhesive, with the silicone rubber-coated side facing inward, and then sewing the adhesive layer together. Alternatively, a predetermined coating amount of an addition-curable liquid silicone rubber composition for airbags can be coated on both outer sides of an airbag fabric previously produced by woven fabric, as described above, and then cured under predetermined curing conditions. While known adhesives can be used, a silicone adhesive known as a seam sealant is preferred in terms of adhesive strength, adhesion durability, etc.

[0101] The present invention will be specifically described below with reference to Preparation Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples. The viscosity and weight-average molecular weight (weight-average degree of polymerization) shown below are values ​​determined under the conditions described above.

[0102] The following components were used as component (A): (A-1): A linear dimethylpolysiloxane whose molecular chain is terminally capped with vinyldimethylsiloxy groups and whose weight-average degree of polymerization is 750 and whose viscosity is 30,000 mPa·s; (A-2): A linear dimethylpolysiloxane whose molecular chain is terminally capped with vinyldimethylsiloxy groups and whose weight-average degree of polymerization is 450 and whose viscosity is 5,000 mPa·s; (A-3): A linear dimethylpolysiloxane whose molecular chain is terminally capped with vinyldimethylsiloxy groups and whose weight-average degree of polymerization is 200 and whose viscosity is 1,000 mPa·s.

[0103] The following component was used as component (B): (CH ３ ) ３ SiO １／２39.5 mol% of units and (CH ３ ) ２ (CH ２ =CH)SiO １／２ 6.5 mol% of units and SiO ２ A powdery organopolysiloxane resin with a three-dimensional network structure, consisting of 54 mol% units and having a weight-average molecular weight of 6,000.

[0104] The following component was used as component (C): (C): A linear dimethylsiloxane-methylhydrogensiloxane copolymer (hydrosilyl group content: 0.0089 mol / g) with both molecular chain terminals capped with trimethylsiloxy groups, a weight-average degree of polymerization of 20, an average of 9 hydrosilyl groups per molecule, and a viscosity of 8 mPa s.

[0105] The following component was used as component (D): (D): Specific surface area of ​​300 m2 by BET method ２ / g of silica fine powder (product name: Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.)

[0106] The following component was used as component (E): (E): hexamethyldisilazane

[0107] The following component was used as component (F): (F): a dimethylpolysiloxane solution containing 1% by mass of a chloroplatinic acid / 1,3-divinyltetramethyldisiloxane complex in terms of platinum atom content.

[0108] The following component was used as component (G): (G): γ-glycidoxypropyltrimethoxysilane

[0109] The following components were used as component (H): (H-1): diisopropoxybis(ethylacetoacetate)titanium (trade name: TC-750, manufactured by Matsumoto Fine Chemical Co., Ltd.) according to the present invention; (H-2): dibutoxybis(ethylacetoacetate)zirconium (trade name: ZC-580, manufactured by Matsumoto Fine Chemical Co., Ltd.) according to the present invention; (H-3): diisopropoxybis(acetylacetonate)titanium (trade name: TC-100, manufactured by Matsumoto Fine Chemical Co., Ltd.) not according to the present invention; (H-4): tetraacetylacetonate zirconium (trade name: ZC-162, manufactured by Matsumoto Fine Chemical Co., Ltd.) not according to the present invention; (H-5): monobutoxytri(acetylacetonate)zirconium (trade name: ZC-540, manufactured by Matsumoto Fine Chemical Co., Ltd.) not according to the present invention. (H-6): Tetraoctyl titanate (trade name: TA-30, manufactured by Matsumoto Fine Chemical Co., Ltd.) Not according to the present invention

[0110] The following component was used as the curing retarder: Curing retarder: 1-ethynylcyclohexanol

[0111] [Preparation Example 1] 60 parts by mass of base oil (A-1), 8 parts by mass of hexamethyldisilazane (E), 2 parts by mass of water, and 40 parts by mass of silica fine powder (D) were placed in a kneader and mixed at room temperature for 1 hour. Next, the temperature was raised to 150°C, and mixing was continued for 2 hours. After this, 30 parts by mass of base oil (A-1) was added and mixed until uniform, to obtain a base compound.

[0112] Examples 1 to 4 and Comparative Examples 1 to 6 The components in the formulations shown in Tables 1 and 2 were mixed in a mixer at room temperature for 30 minutes to prepare two-part addition-curable liquid silicone rubber compositions for air bags, consisting of parts A and B. The above-mentioned base compound was used for components (D) and (E).

[0113] <Method of Preparing Silicone Rubber Coated Base Fabric> Each of the silicone rubber coating compositions for air bags prepared in Tables 1 and 2 was mixed with liquid A and liquid B in a 1:1 ratio on a 210 denier PA66 base fabric, and the mixture was vacuum degassed to a thickness of 25 g / m ２The fabric was knife-coated using a knife coater (device used: LTE-S; manufactured by MATHIS) so that the silicone rubber coating composition became 100%. The fabric was then placed in a dryer at 200°C for 1 minute to cure the silicone rubber coating composition, thereby preparing a silicone rubber-coated fabric.

[0114] <Slip resistance test method> The above silicone-coated airbag base fabric was cut to a size of 50 mm wide x 300 mm long, and the slip resistance in the warp direction and weft direction was measured using the method described in ASTM D6479-15:2020 (apparatus used: Autograph AGS-X; manufactured by Shimadzu Corporation). The median values ​​of the results measured with N = 5 are shown in Table 1.

[0115] <Thickening Acceleration Test Method> For the silicone rubber compositions prepared in Tables 1 and 2, parts A and B were each filled into a 100 mL glass bottle, sealed, and stored in a 70°C oven for 504 hours. The bottle was then allowed to cool to room temperature, stirred, degassed, and the viscosity was measured. The results are shown in Table 1.

[0116]

[0117]

[0118] As can be seen from Table 1, Examples 1 to 4, which used the addition-curable liquid silicone rubber composition for air bags of the present invention, exhibited high slippage resistance and excellent base fabric strength. Furthermore, an accelerated thickening test at 70°C for 504 hours showed almost no increase in viscosity.

[0119] On the other hand, as can be seen from Table 2, when component (H) did not contain the ligand represented by formula (1) (Comparative Examples 3 to 6), when component (H) itself was not included (Comparative Example 1), and when the amount of component (H) contained was insufficient (Comparative Example 2), the slippage resistance values ​​were lower than those of the Examples, and the base fabric strength was inferior. Furthermore, in some examples, the viscosity of solution A increased significantly, resulting in inferior storage stability.

[0120] This specification encompasses the following aspects: [1] (A) 100 parts by mass of a linear organopolysiloxane containing two or more silicon-bonded alkenyl groups per molecule and having a weight-average degree of polymerization of 50 to 2,000, (B) 0.1 to 100 parts by mass of a powdery three-dimensional network organopolysiloxane resin, (C) a linear organohydrogenpolysiloxane whose ends are capped with trialkylsilyl groups and containing two or more hydrosilyl groups per molecule, in an amount such that the total number of hydrosilyl groups contained in the composition is 1 to 10 moles per mole of silicon-bonded alkenyl groups, and (D) a polymer having a BET specific surface area of ​​50 m ２ / g or more: 1 to 50 parts by mass, (E) a surface treatment agent selected from silazanes or chlorosilanes: 10 to 60 parts by mass per 100 parts by mass of the silica fine powder of component (D), (F) a hydrosilylation reaction catalyst: 1 to 500 ppm in terms of the mass of catalytic metal element relative to the total mass of components (A) to (D), (G) an organosilicon compound containing an adhesion-imparting functional group: 0.1 to 10 parts by mass, and (H) a titanium or zirconium compound containing one or more ligands represented by the following formula (1): (wherein * indicates a bond to a metal atom, and R １each independently represents a hydrocarbon group having 1 to 10 carbon atoms.) [2] The addition-curable liquid silicone rubber composition for air bags according to [1], wherein component (H) is diisopropoxybis(ethylacetoacetate)titanium or dibutoxybis(ethylacetoacetate)zirconium. [3] The addition-curable liquid silicone rubber composition for air bags according to [1] or [2], wherein component (G) is an organosilicon compound having, per molecule, one or more reactive silyl groups selected from an alkoxysilyl group, an alkenyl-containing silyl group, and a hydrosilyl group, and one or more reactive organic groups selected from an epoxy group, an isocyanate group, and a (meth)acrylic group. [4] The addition-curable liquid silicone rubber composition for air bags according to any one of [1] to [3], wherein component (E) is hexamethyldisilazane or 1,3-divinyl-1,1,3,3-tetramethyldisilazane. [5] An airbag characterized by having a cured coating of the addition-curable liquid silicone rubber composition for airbags described in any one of [1] to [4] on an airbag base fabric.

[0121] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits similar effects is included within the technical scope of the present invention.

Claims

1. (A) 100 parts by mass of a linear organopolysiloxane containing two or more silicon-bonded alkenyl groups per molecule and having a weight-average degree of polymerization of 50 to 2,000; (B) 0.1 to 100 parts by mass of a powdery three-dimensional network organopolysiloxane resin; (C) a linear organohydrogenpolysiloxane whose terminals are capped with trialkylsilyl groups and containing two or more hydrosilyl groups per molecule, in an amount such that the total number of hydrosilyl groups contained in the composition is 1 to 10 moles per mole of silicon-bonded alkenyl groups; (D) a composition having a BET specific surface area of ​​50 m ２ / g or more: 1 to 50 parts by mass, (E) a surface treatment agent selected from silazanes or chlorosilanes: 10 to 60 parts by mass per 100 parts by mass of the silica fine powder of component (D), (F) a hydrosilylation reaction catalyst: 1 to 500 ppm in terms of the mass of catalytic metal element relative to the total mass of components (A) to (D), (G) an organosilicon compound containing an adhesion-imparting functional group: 0.1 to 10 parts by mass, and (H) a titanium or zirconium compound containing one or more ligands represented by the following formula (1): (wherein * indicates a bond to a metal atom, and R １ each independently represents a hydrocarbon group having 1 to 10 carbon atoms.

2. The addition-curable liquid silicone rubber composition for air bags according to claim 1, wherein component (H) is diisopropoxybis(ethylacetoacetate)titanium or dibutoxybis(ethylacetoacetate)zirconium.

3. The addition-curable liquid silicone rubber composition for airbags according to claim 1, characterized in that component (G) is an organosilicon compound having, in one molecule, one or more reactive silyl groups selected from alkoxysilyl groups, alkenyl-containing silyl groups, and hydrosilyl groups, and one or more reactive organic groups selected from epoxy groups, isocyanate groups, and (meth)acrylic groups.

4. The addition-curable liquid silicone rubber composition for air bags according to claim 1, wherein component (E) is hexamethyldisilazane or 1,3-divinyl-1,1,3,3-tetramethyldisilazane.

5. An airbag characterized by having a cured coating of the addition-curing liquid silicone rubber composition for airbags according to any one of claims 1 to 4 on an airbag base fabric.

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