JP2022030018A - Addition-curable type liquid silicone rubber composition for airbag and airbag - Google Patents

Abstract

To provide a flame retardant airbag excellent in low combustion velocity property and mechanical strength, and to provide an addition-curable type liquid silicone rubber composition for the flame retardant airbag.SOLUTION: An addition-curable type liquid silicone rubber composition for an airbag comprises (A) an organopolysiloxane having a polymerization degree of 50 to 2,000 containing an alkenyl group bonded to two or more silicon atoms in one molecule, (B) an organohydrogenpolysiloxane containing a hydrogen atom bonded to at least two silicon atoms (SiH group) in one molecule, (C) a silica fine powder having a BET specific surface area of 50 m2/g or more, (D) a catalyst for hydrosilylation reaction, (E) an organosilicon compound containing an adhesivity-imparting functional group, and (F) an organic compound having at least one ether bond in one molecule and not containing an adhesivity-imparting functional group.SELECTED DRAWING: None

Description

The present invention relates to an addition-curable liquid silicone rubber composition for an air bag and an air bag suitable for producing an air bag.

Conventionally, a silicone rubber composition for an air bag has been proposed for the purpose of forming a rubber film on the fiber surface. An airbag having a silicone rubber film is excellent in airtightness and low combustion speed (flame retardancy), and is therefore suitably used as an airbag for automobiles and the like.

Such a silicone coating composition for an air bag is an addition-curable liquid silicone having excellent internal pressure retention by combining a cross-linking agent having a hydrosilyl group at both ends of the molecular chain and a cross-linking agent having a hydrosilyl group at the side chain. An air bag containing a rubber composition (Patent Document 1) and a resin-like polysiloxane, and coating the fiber surface with a liquid silicone composition produced by premixing a siloxane component with silica, a surface treatment agent, and water (Patent Document 1). 2) A method for producing an air bag having excellent internal pressure retention by coating a base cloth with an addition-curable silicone rubber composition using a branched-chain organopolysiloxane containing Q units as a base polymer (Patent Document 3). , T unit or Q unit-containing organohydrogenpolysiloxane is used as a cross-linking agent, and an addition-curable liquid silicone rubber composition having excellent strength of a coating base cloth (Patent Document 4) and the like are disclosed.

However, the coating base cloth for air bags manufactured by coating the conventional additive-curable liquid silicone rubber composition on the base cloth for air bags and curing the base cloth for air bags can be used as the base cloth for air bags with the low coating amount required in recent years. It did not satisfy the required low burning rate.

Japanese Patent Publication No. 2013-513695 Japanese Unexamined Patent Publication No. 2013-209517 Special Table 2013-516521 Special Table 2019-513907 Gazette

The present invention has been made in view of the above circumstances, and FMVSS (Federal Motor Vehicle Safety Standards) NO. It is an object of the present invention to provide a flame-retardant air bag and an addition-curable liquid silicone rubber composition for a flame-retardant air bag, which are excellent in low combustion speed and mechanical strength specified in 302. ..

In order to solve the above problems, in the present invention, the addition-curable liquid silicone rubber composition for an air bag is used.
(A) Organopolysiloxane having a degree of polymerization of 50 to 2,000 containing an alkenyl group bonded to two or more silicon atoms in one molecule: 100 parts by mass,
(B) Organohydrogenpolysiloxane containing a hydrogen atom (SiH group) bonded to at least two silicon atoms in one molecule: SiH group contained in the composition is a silicon atom bond contained in the composition. Amount of alkenyl groups totaling 1-10 mol per mol,
(C) BET method Silica fine powder having a specific surface area of 50 m ² / g or more: 1 to 50 parts by mass,
(D) Catalyst for hydrosilylation reaction: catalyst amount,
(E) Organosilicon compound containing an adhesive-imparting functional group: 0.1 to 10 parts by mass,
(F) An organic compound having at least one ether bond in one molecule and not containing an adhesive-imparting functional group: 0.1 to 10 parts by mass,
Provided is an addition-curable liquid silicone rubber composition for an air bag, which comprises.

In the case of such an addition-curable liquid silicone rubber composition for airbags, FMVSS NO. It is possible to obtain a flame-retardant air bag having excellent low combustion speed and mechanical strength specified in 302.

Further, it is preferable that the adhesive-imparting functional group is one or more groups selected from an epoxy group, a silicon atom-bonded alkoxy group, a hydrosilyl group, an isocyanate group, an acrylic group and a methacrylic group.

With such an addition-curable liquid silicone rubber composition for an air bag, the development of adhesiveness to the base cloth for an air bag can be further improved.

Further, as the component (G), at least one condensation catalyst selected from an organic titanium compound, an organic zirconium compound, and an organoaluminum compound is added in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the component (A). It is preferable to contain it.

In such an addition-curable liquid silicone rubber composition for an air bag, the component (G) may act as a condensation assisting catalyst for the adhesive-imparting functional group in the component (E) to promote adhesion. can.

Further, it is preferable that the component (F) is a homopolymer or copolymer of ethylene oxide, propylene oxide, or tetrahydrofuran, or a dialkyl ether.

Such a component (F) can improve the flame retardancy and mechanical strength of the cured product of the additive-curable liquid silicone rubber composition for an air bag of the present invention.

In particular, it is preferable that the component (F) is a polyether-modified polysiloxane.

Such a component (F) can further improve the flame retardancy and mechanical strength of the cured product of the obtained additive-curable liquid silicone rubber composition for an air bag.

Further, as the component (H), a powdery three-dimensional network-like organopolysiloxane resin (however, the organopolysiloxane resin does not contain a silicon atom-bonded hydrogen atom in the molecule) is used as the component (A) by 100 mass. It is preferably contained in an amount of 0.1 to 100 parts by mass with respect to the part.

With such an addition-curable liquid silicone rubber composition for an air bag, the flame retardancy of the obtained cured silicone rubber can be further improved.

Further, the present invention provides an air bag having a cured film of the addition-curable liquid silicone rubber composition for an air bag on a base cloth for an air bag.

Such an air bag of the present invention is excellent in flame retardancy and mechanical strength.

As described above, according to the present invention, it is possible to obtain an addition-curable liquid silicone rubber composition for an air bag capable of producing a silicone-coated base cloth for manufacturing an air bag having a low combustion rate and excellent mechanical strength.

As mentioned above, FMVSS NO. There has been a demand for the development of flame-retardant air bags and addition-curable liquid silicone rubber compositions for flame-retardant air bags, which are excellent in low combustion speed and mechanical strength specified in 302.

As a result of diligent studies to achieve the above object, the present inventors have made the components (A) to (F) described later, specifically, the addition-curable liquid silicone rubber composition with the component (F). It is obtained by applying the composition to the surface of a base cloth for an air bag and heat-curing it by combining an organic compound containing one or more ether bonds in one molecule and not containing an adhesive-imparting functional group. We have found that a silicone-coated base cloth for manufacturing an air bag is excellent in low combustion speed and mechanical strength, and have come to this invention.

That is, the present invention is an addition-curable liquid silicone rubber composition for an air bag.
(A) Organopolysiloxane having a degree of polymerization of 50 to 2,000 containing an alkenyl group bonded to two or more silicon atoms in one molecule: 100 parts by mass,
(B) Organohydrogenpolysiloxane containing a hydrogen atom (SiH group) bonded to at least two silicon atoms in one molecule: SiH group contained in the composition is a silicon atom bond contained in the composition. Amount of alkenyl groups totaling 1-10 mol per mol,
(C) BET method Silica fine powder having a specific surface area of 50 m ² / g or more: 1 to 50 parts by mass,
(D) Catalyst for hydrosilylation reaction: catalyst amount,
(E) Organosilicon compound containing an adhesive-imparting functional group: 0.1 to 10 parts by mass,
(F) An organic compound having at least one ether bond in one molecule and not containing an adhesive-imparting functional group: 0.1 to 10 parts by mass,
It is an addition hardening type liquid silicone rubber composition for an air bag containing.

Hereinafter, the present invention will be described in more detail. In the present specification, the viscosity is a value measured by a rotational viscometer by the method described in JIS K 7117-1: 1999 at 25 ° C. The degree of polymerization is a value obtained as a polystyrene-equivalent weight average degree of polymerization (weight average molecular weight) in GPC (gel permeation chromatography) analysis using toluene as a developing solvent.

<Additional curing type liquid silicone rubber composition>
The addition-curable liquid silicone rubber composition for an air bag of the present invention contains the following components (A) to (F) and is liquid at room temperature (25 ° C.). Hereinafter, each component will be described in detail.

[(A) component]
Organopolysiloxane as a component (A) contains two or more alkenyl groups bonded to silicon atoms in one molecule, has a degree of polymerization of 50 to 2,000, and is preferably liquid at 25 ° C. It is a siloxane and is a base polymer (main agent) of the composition according to the present invention.

Examples of the molecular structure of the component (A) include linear, cyclic, branched chain, etc., but the main chain basically consists of repeating diorganosiloxane units, and both ends of the molecular chain are triorganosyloxy. Linear diorganopolysiloxanes sealed with a group are preferred. When the molecular structure of the organopolysiloxane component (A) is linear or branched, the position of the silicon atom to which the alkenyl group is bonded in the molecule of the organopolysiloxane is the terminal of the molecular chain (that is, that is, Either one or both of the triorganosyloxy group) and the middle of the molecular chain (that is, the bifunctional diorganosiloxane unit or the trifunctional monoorganosylsesquioxane unit located at the non-terminal of the molecular chain) may be used. Particularly preferred as the component (A) is a linear diorganopolysiloxane containing at least an alkenyl group bonded to silicon atoms at both ends of the molecular chain.

Examples of the alkenyl group bonded to the silicon atom in the component (A) include those having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms. Specific examples thereof include a vinyl group, an allyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a cyclohexenyl group, a heptenyl group and the like, and a vinyl group is particularly preferable.

The content of the alkenyl group bonded to the silicon atom in the component (A) is 0.001 with respect to the entire monovalent organic group bonded to the silicon atom (that is, the unsubstituted or substituted monovalent hydrocarbon group). It is preferably about 10 mol%, and particularly preferably about 0.01 to 5 mol%.

The monovalent organic group bonded to the silicon atom other than the alkenyl group of the component (A) is, for example, the same or different substituents, usually 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms. The monovalent hydrocarbon group of is mentioned. Specific examples of the monovalent organic group include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group and a heptyl group; a phenyl group, a trill group, a xsilyl group and a naphthyl group. Alaryl groups such as benzyl group and phenethyl group; halogen-substituted alkyl groups such as chloromethyl group, 3-chloropropyl group and 3,3,3-trifluoropropyl group, and the like, in particular, methyl group. Is preferable.

The degree of polymerization of the component (A) is 50 to 2,000, more preferably 100 to 1,500. If the degree of polymerization is lower than 50, the mechanical properties of the obtained silicone rubber may deteriorate, and if the degree of polymerization is greater than 2,000, the viscosity of the obtained silicone rubber composition becomes high, and the coating workability is increased. May get worse. When the component (A) is a mixture of a plurality of components, the sum of the products of the degree of polymerization of each component and the mass fraction is taken as the degree of polymerization of the component (A).

Specific examples of the organopolysiloxane of the component (A) include a trimethylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane copolymer at both ends of the molecular chain, a trimethylsiloxy group-blocked methylvinylpolysiloxane at both ends of the molecular chain, and trimethyl at both ends of the molecular chain. Syroxy group-blocked dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer, molecular chain double-ended dimethylvinyl syroxy group-blocked dimethylpolysiloxane, molecular chain double-ended dimethylvinylsiloxy group-blocked methylvinylpolysiloxane, molecular chain double-ended dimethylvinyl Syloxy group-blocked dimethylsiloxane / methylvinylsiloxane copolymer, molecular chain double-ended dimethylvinylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer, molecular chain double-ended divinylmethylsiloxy group-blocked dimethylpolysiloxane, molecule Divinylmethylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane copolymer at both ends of the chain, trivinylsiloxy group-blocked dimethylpolysiloxane at both ends of the molecular chain, trivinylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane copolymer at both ends of the molecular chain, And a mixture of two or more of these organopolysiloxanes.

The organopolysiloxane of the component (A) may be used alone or in combination of two or more.

[(B) component]
The organohydrogenpolysiloxane of the component (B) mainly reacts with the alkenyl group in the component (A) by hydrosilylation addition reaction and acts as a cross-linking agent (curing agent).
Examples of the molecular structure of the component (B) include various structures such as linear, cyclic, branched chain, and three-dimensional network (resin-like) structures, and at least two, preferably three, are included in one molecule. It is necessary to have a hydrogen atom (SiH group) bonded to one or more silicon atoms, and it is usually preferable to have 2 to 300, preferably 3 to 200, more preferably 4 to 100 SiH groups, 25. It is preferably liquid at ° C. Such a SiH group may be located at the end of the molecular chain or in the middle of the molecular chain, or may be located at both of them.

As this organohydrogenpolysiloxane, those represented by the following average composition formula (1) can be used.

In formula (1), R ¹ is an unsubstituted or substituted monovalent hydrocarbon bonded to a silicon atom, preferably having 1 to 10 carbon atoms, excluding aliphatic unsaturated bonds such as alkenyl groups, which are the same or different from each other. Groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, decyl group and the like. Alkyl group such as alkyl group, phenyl group, trill group, xylyl group, naphthyl group, aralkyl group such as benzyl group, phenylethyl group and phenylpropyl group, and some or all of the hydrogen atoms of these groups are fluorine. Examples thereof include those substituted with a halogen atom such as bromine and chlorine, such as a chloromethyl group, a chloropropyl group, a bromoethyl group and a trifluoropropyl group. R ¹ is preferably an alkyl group or an aryl group, and more preferably a methyl group. Further, a is preferably 0.7 to 2.1, b is 0.001 to 1.0, and a + b is preferably a positive number satisfying 0.8 to 3.0, and more preferably a is 1.0 to 1.0. 2.0 and b are 0.01 to 1.0, and a + b is a positive number satisfying 1.5 to 2.5.

Examples of the organohydrogenpolysiloxane of the component (B) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, and tris (hydrogendimethylsiloxy). Methylsilane, Tris (hydrogendimethylsiloxy) phenylsilane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane / dimethylsiloxane cyclic copolymer, trimethylsiloxy group-sealed methylhydrogenpolysiloxane at both ends of the molecular chain, trimethyl at both ends of the molecular chain Syloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, molecular chain double-ended trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane / methylphenylsiloxane copolymer, molecular chain double-ended trimethylsiloxy group-blocked dimethylsiloxane / methylhydro Gensiloxane / diphenylsiloxane copolymer, molecular chain double-ended dimethylhydrogensiloxy group-blocked methylhydrogenpolysiloxane, molecular chain double-ended dimethylhydrogensiloxy group-blocked dimethylpolysiloxane, molecular chain double-ended dimethylhydrogensiloxy group-blocked dimethyl Siloxane / Methylhydrogensyloxy group-blocked dimethylhydroxyloxy group-blocked dimethylsiloxane / methylphenylsiloxane copolymer, dimethylhydrogensiloxy group-blocked dimethylsiloxane / diphenylsiloxane copolymer at both ends of the molecular chain, molecule In the dimethylhydrogensiloxy group-blocked methylphenylpolysiloxane at both ends of the chain, the dimethylhydrogensiloxy group-blocked diphenylpolysiloxane at both ends of the molecular chain, and in each of these exemplary compounds, part or all of the methyl group is an ethyl group, a propyl group, etc. Substituted with other alkyl groups, formula: ^R2 ₃ siloxane unit represented by SiO _1/2 and formula: R2 ² HSiO _{1/2 represented} by siloxane unit and formula: SiO _4/2 . Organosiloxane copolymer consisting of siloxane units, formula: R2 ₂ HSiO Organosiloxane copolymer consisting of siloxane units represented by _1/2 and formula: SiO _4/2 , organosiloxane copolymer, _formula : R ² HSiO ² Is it a siloxane unit represented by _{/ 2} and a siloxane unit represented by the formula: ^R2 SiO _3/2 or a siloxane unit represented by the formula: HSiO _3/2 ? Examples thereof include an organosiloxane copolymer comprising two or more kinds of these organopolysiloxanes. R ² in the above formula is a monovalent hydrocarbon group other than the alkenyl group.

The blending amount of the component (B) is such that the SiH group contained in the composition is 1 to 10 mol per 1 mol of the total silicon atom-bonded alkenyl group contained in the composition. For example, 1 to 10 mol (or pieces) of SiH groups contained in the component (B) are preferably 1 mol (or pieces) with respect to a total of 1 mol (or pieces) of silicon atom-bonded alkenyl groups contained in the component (A). The amount is 2 to 9 mol (or pieces), more preferably 1.5 to 8 mol (or pieces).
If the SiH group contained in the composition is less than 1 mol with respect to the total of 1 mol of the silicon atom-bonded alkenyl groups contained in the composition, the composition is not sufficiently cured, and this exceeds 10 mol. The heat resistance of the obtained cured silicone rubber product may be extremely inferior.

As the component (B), organohydrogenpolysiloxane may be used alone or in combination of two or more.

[(C) component]
The silica fine powder of the component (C) acts as a reinforcing filler. That is, it imparts strength to the cured silicone rubber obtained from the composition according to the present invention, and by using silica fine powder as a reinforcing filler, a coating film satisfying the strength required for an air bag is formed. It becomes possible to do. The silica fine powder needs to have a specific surface area (BET method) of 50 m ² / g or more, preferably 50 to 400 m ² / g, more preferably 100 to 300 m ² / g, and a specific surface area. If it is less than 50 m ² / g, it is not possible to impart satisfactory strength characteristics. Generally, the particle size of the silica fine powder is 1 to 100 nm, but accurate measurement is difficult due to the large aggregation.

The silica fine powder may be a known silica fine powder that has been conventionally used as a reinforcing filler for silicone rubber, provided that the specific surface area is within the above range. Silica), precipitated silica (wet silica) and the like.

The silica fine powder may be a surface treatment agent such as an organosilicon compound (usually hydrolyzable) such as chlorosilane, alkoxysilane, or organosilazane, and the surface of the silica fine powder may be hydrolyzed. .. In that case, as these silica fine powders, those which have been directly surface-hydrophobicized with a surface treatment agent in the state of powder in advance may be used, or silicone oil (for example, the alkenyl group of the component (A) above). A surface treatment agent may be added at the time of kneading with the contained organopolysiloxane) to make the surface hydrophobic.

As a usual treatment method for the component (C), the surface can be treated by a known technique. For example, the untreated silica fine powder and the surface treatment agent are applied to a mechanical kneading device or a fluidized bed sealed at normal pressure. It can be added and mixed at room temperature (25 ° C.) or heat treatment (heating) in the presence of an inert gas, if necessary. In some cases, water or a catalyst (hydrolysis accelerator, etc.) may be used to accelerate the surface treatment. After kneading, the surface-treated silica fine powder can be produced by drying. The blending amount of the surface treatment agent may be an amount calculated from the covering area of the surface treatment agent or more.

Specific examples of the surface treatment agent include silazanes such as hexamethyldisilazane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, and vinyltri. Silane coupling agents such as ethoxysilane, vinyltrimethoxysilane, trimethylmethoxysilane, triethylmethoxysilane, vinyltris (methoxyethoxy) silane, trimethylchlorosilane, dimethyldichlorosilane, divinyldimethoxysilane and chloropropyltrimethoxysilane, polymethylsiloxane, Examples thereof include organohydrogenpolysiloxane, which can be surface-treated and used as a hydrophobic silica fine powder. As the surface treatment agent, silazanes are particularly preferable.

The blending amount of the component (C) is 1 to 50 parts by mass, preferably 5 to 30 parts by mass with respect to 100 parts by mass of the organopolysiloxane of the component (A). If the blending amount is too small, the strength required for the air bag cannot be obtained, and if the blending amount is too large, the viscosity of the composition may increase, the fluidity may decrease, and the coating workability may deteriorate.

The fine powder silica of the component (C) may be used alone or in combination of two or more.

[(D) component]
The catalyst for the hydrosilylation reaction of the component (D) promotes the addition reaction between the silicon atom-bonded alkenyl group contained in the composition and the SiH group contained in the composition. It mainly promotes the addition reaction between the alkenyl group bonded to the silicon atom in the component (A) and the SiH group in the component (B). The catalyst for the hydrosilylation reaction is not particularly limited, and includes, for example, platinum group metals such as platinum, palladium, and rhodium; platinum chloride acid; alcohol-modified platinum chloride acid; platinum chloride acid, and olefins, vinylsiloxane, or acetylene compounds. Coordination compounds; Platinum group metal compounds such as tetrakis (triphenylphosphine) palladium and chlorotris (triphenylphosphine) rhodium are mentioned, and platinum group metal compounds are preferable.

The blending amount of the component (D) may be an effective amount (catalytic amount) as a catalyst, but is preferably in terms of the mass of the catalyst metal element with respect to the total mass of the components (A) to (C). It is 1 to 500 ppm, more preferably 5 to 100 ppm. If it is 1 ppm or more, the addition reaction will not be significantly delayed or the composition will not be cured, and if it is 500 ppm or less, the heat resistance of the cured product will not be lowered.

The catalyst for the hydrosilylation reaction of the component (D) may be used alone or in combination of two or more.

[(E) component]
The component (E) is an organic silicon compound containing an adhesive-imparting functional group, and the adhesive-imparting functional group includes an epoxy group, a silicon atom-bonded alkoxy group (alkoxysilyl group), a hydrosilyl group, an isocyanate group, and an acrylic group. , Methacyl groups and the like, and are added in order to develop and improve the adhesiveness of the silicone rubber composition to the base cloth for an air bag.

As the organic silicon compound, any organic silicon compound can be used as long as it has such an adhesive-imparting functional group, but an organic having one or more epoxy groups and one or more silicon atom-bonded alkoxy groups in one molecule. It is preferably a silicon compound, and has at least one epoxy group and at least one silicon atom-bonded alkoxy group (for example, a trialkoxysilyl group, an organodiakoxysilyl group, etc.) from the viewpoint of adhesion development. An organic silicon compound, for example, an organosilane, or a cyclic or linear organosiloxane having 1 to 100, preferably 1 to 50 silicon atoms, with at least one epoxy group and at least two. Those having a silicon atom-bonded alkoxy group are more preferable.

The epoxy group is, for example, a silicon atom in the form of a glycidoxyalkyl group such as a glycidoxypropyl group; an epoxy-containing cyclohexylalkyl group such as a 2,3-epoxycyclohexylethyl group or a 3,4-epoxycyclohexylethyl group. It is preferable that it is bound to.
The silicon atom-bonded alkoxy group is bonded to a silicon atom to form, for example, a trialkoxysilyl group such as a trimethoxysilyl group or a triethoxysilyl group; a methyldimethoxysilyl group, an ethyldimethoxysilyl group, a methyldiethoxysilyl group, or an ethyldi. It is preferable to form an alkyldialkoxysilyl group such as an ethoxysilyl group.

Further, the component (E) has an alkenyl group such as a vinyl group, an acrylic group, a (meth) acryloxy group, an isocyanate group, and a hydrosilyl as a functional group other than the epoxy group and the silicon atom-bonded alkoxy group in one molecule. It may have at least one functional group selected from the group consisting of groups (SiH groups).

Examples of the organic silicon compound as the component (E) include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, (3,4-epoxycyclohexylethyl) trimethoxysilane, and (3). 4-Epoxycyclohexylethyl) triethoxysilane, (3,4-epoxycyclohexylethyl) methyldimethoxysilane, (3,4-epoxycyclohexylethyl) methyldiethoxysilane, (2,3-epoxycyclohexylethyl) triethoxysilane, Epoxy group-containing silane coupling agents such as (2,3-epoxycyclohexylethyl) methyldimethoxysilane, (2,3-epoxycyclohexylethyl) methyldiethoxysilane (ie, epoxy functional group-containing organoalkoxysilane), vinyltri. Vinyl group-containing silane coupling agent such as methoxysilane, acrylic group-containing silane coupling agent such as 3-acryloxypropyltrimethoxysilane, isocyanate group-containing silane coupling agent such as 3-isocyandiapropylethoxysilane, or triallyl isocia. In addition to a silane coupling agent such as a methoxysilyl modified product of Nurate, an organic silicon compound such as a cyclic organopolysiloxane represented by the following chemical formula or a linear organopolysiloxane, a mixture of two or more thereof, or a mixture thereof. Examples thereof include one type or two or more types of partially hydrolyzed condensates.

（式中、Ｒの少なくとも１つは－ＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３であり、ｈは１～１０の整数、ｋは０～４０の整数、好ましくは０～２０の整数、ｐは１～４０の整数、好ましくは１～２０の整数、ｑは１～１０の整数である。）

(In the equation, at least one of R is −CH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , h is an integer of 1 to 10, k is an integer of 0 to 40, preferably an integer of 0 to 20. p is an integer of 1 to 40, preferably an integer of 1 to 20, and q is an integer of 1 to 10.)

The blending amount of the component (E) is 0.1 to 10 parts by mass, preferably 0.25 to 5 parts by mass with respect to 100 parts by mass of the organopolysiloxane of the component (A). If the blending amount is less than 0.1 parts by mass, the obtained composition may not exhibit sufficient adhesive strength. If the blending amount exceeds 10 parts by mass, the cost becomes high and it is uneconomical.

When the component (E) contains an alkenyl group and / or a SiH group, the SiH group contained in the composition is 1 to 10 mol per 1 mol of the total silicon atom-bonded alkenyl group contained in the composition. Is the amount. For example, the total number of SiH groups contained in the component (B) and the component (E) with respect to a total of 1 mol (or pieces) of the silicon atom-bonded alkenyl groups contained in the component (A) and the component (E) in the composition. The amount can be 1 to 10 mol (or piece), preferably 1.2 to 9 mol (or piece), more preferably 1.5 to 8 mol (or piece). If the SiH group is less than 1 mol with respect to 1 mol of the silicon atom-bonded alkenyl group in the composition, the composition may not be sufficiently cured and may not exhibit sufficient adhesive strength. On the other hand, if this exceeds 10 mol, the heat resistance of the obtained cured silicone rubber product may be extremely inferior.

The component (E) may be used alone or in combination of two or more.

[(F) component]
The component (F) is an organic compound containing at least one ether bond in one molecule and does not contain an adhesive-imparting functional group, and acts as a flame retardant improving agent and a mechanical strength improving agent. Here, as described above, examples of the adhesive-imparting functional group include an epoxy group, a silicon atom-bonded alkoxy group (alkoxysilyl group), a hydrosilyl group, an isocyanate group, an acrylic group, and a methacrylic group. The component (F) can be any organic compound as long as the above conditions are satisfied, but it may be a homopolymer of ethylene oxide, propylene oxide or tetrahydrofuran or a copolymer thereof, a dialkyl ether, or a polyether-modified polysiloxane. It is preferable to have.

（Ｒ^３は互いに同一又は異種の炭素数５～２０の一価炭化水素基又は炭素数５～２０のアルケニル基を表す） Examples of the dialkyl ether as the component (F) include the following compounds.

(R ³ represents a monovalent hydrocarbon group having 5 to 20 carbon atoms or an alkenyl group having 5 to 20 carbon atoms, which are the same or different from each other).

（ｌ、ｍ、ｎは１～１００の整数、Ｒ^４は互いに同一又は異種の炭素数１～１０の一価炭化水素基又は、炭素数１～１０のアルケニル基、又は水素原子を表す） Examples of the homopolymer of ethylene oxide, propylene oxide, or tetrahydrofuran of the component (F), or a copolymer thereof, include the following polymers.

(L, m, n are integers of 1 to 100, ^R4 represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkenyl group having 1 to 10 carbon atoms, or a hydrogen atom having the same or different carbon atoms).

（ｙは０～１００の整数、ｚは１～１００の整数、Ｒ^５は同一又は異種の炭素数１～１０の一価炭化水素基又は、炭素数１～１０のアルケニル基を、Ｒ^６は上記の構造でありｌ、ｍ、ｎは１～１００の整数、Ｒ^７は炭素数１～１０の一価炭化水素基又は水素原子を表す） Further, examples of the polyether-modified polysiloxane of the component (F) include the following polysiloxanes.

(Y is an integer of 0 to 100, z is an integer of 1 to 100, R ⁵ is a monovalent hydrocarbon group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms, and R ⁶ is an alkenyl group having 1 to 10 carbon atoms. In the above structure, l, m, and n are integers of 1 to 100, and R ⁷ represents a monovalent hydrocarbon group or a hydrogen atom having 1 to 10 carbon atoms).

When the component (F) contains an alkenyl group, the amount of SiH groups contained in the composition is 1 to 10 mol per 1 mol of the total silicon atom-bonded alkenyl groups contained in the composition. For example, the component (F) is contained in the component (B) and the component (E) with respect to a total of 1 mol of the silicon atom-bonded alkenyl group contained in the component (A), the component (E), and the component (F) in the composition. The amount of SiH groups contained in the above is preferably 1 to 10 mol (or pieces), preferably 1.2 to 9 mol (or pieces), and more preferably 1.5 to 8 mol (or pieces). ..

The component (F) may be used alone or in combination of two or more.

[Other ingredients]
In addition to the above-mentioned components (A) to (F), any other component may be added to the composition according to the present invention, if necessary. Specific examples thereof include the following. Each of these other components may be used alone or in combination of two or more.

[(G) component]
The condensation catalyst of the component (G) is at least one selected from an organic titanium compound, an organic zirconium compound, and an organoaluminum compound, and helps to condense the adhesive-imparting functional group in the component (E) in order to promote adhesion. It acts as a catalyst. Specific examples of the component (G) include organic titanium acid esters such as titanium tetraisopropoxide, titanium tetranormalbutoxide, and titanium tetra-2-ethylhexoxide, titanium diisopropoxybis (acetylacetonate), and the like. Titanium-based condensation co-catalysts (titanium compounds) such as titanium diisopropoxybis (ethylacetacetate), organic titanium chelate compounds such as titanium tetraacetylacetonate, etc.;
Organic zirconium esters such as zirconium tetranormal propoxide and zirconium tetranormal butoxide, zirconium tributoxymonoacetylacetonate, zirconium monobutoxyacetylacetonate bis (ethylacetacetate), organic zirconium chelate compounds such as zirconium tetraacetylacetonate, etc. Zirconium-based condensation co-catalyst (zirconium compound);
Aluminum-based condensation co-catalysts (aluminum compounds) such as organic aluminum acid esters such as aluminum secondary butoxide, aluminum trisacetylacetonate, aluminum bisethylacetate monoacetylacetonate, and organic aluminum chelate compounds such as aluminumtrisethylacetoacetate. Can be mentioned.

The organic titanium compound, the organic zirconium compound, and the organoaluminum compound of the component (G) are optional components to be blended as necessary, and the blending amount thereof is preferably 0 with respect to 100 parts by mass of the component (A). .1 to 5 parts by mass, more preferably 0.2 to 4 parts by mass. When the blending amount is within the above range, the obtained cured product has excellent adhesive durability under high temperature and high humidity.

The component (G) may be used alone or in combination of two or more.

[(H) component]
The component (H) is an organopolysiloxane resin having a powder-like three-dimensional network (resin-like) structure at 25 ° C., preferably a trifunctional R ⁸ SiO _3/2 unit and a tetrafunctional SiO ₄ . Basically composed of at least one branched chain siloxane unit selected from _{/ 2} units, monofunctional R ⁸ ₃ SiO _1/2 units and / or bifunctional R ⁸ ₂ SiO, as required. It is an organopolysiloxane resin having a three-dimensional network structure (the organo group here may also include an alkenyl group), which may optionally contain _2/2 units, and acts as a flame retardant improver. .. However, this organopolysiloxane resin does not contain a silicon atom-bonded hydrogen atom (SiH group) in the molecule. Further, this organopolysiloxane resin has a three-dimensional network (resin-like) structure at 25 ° C., is powdery, and has a basically linear structure at 25 ° C., and is preferably liquid (preferably). A) Ingredients are clearly differentiated.

R ⁸ in the above formula is a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, which is the same as or different from each other, and the alkenyl group exemplified in the component (A) above. Examples thereof include those similar to a monovalent organic group (unsubstituted or substituted monovalent hydrocarbon group), and specifically, a vinyl group, an allyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a cyclohexenyl group. Alkenyl group such as group, heptenyl group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, alkyl group such as heptyl group; phenyl group, trill group, xylyl group, naphthyl group and the like. Aryl groups; aralkyl groups such as benzyl group and phenethyl group; halogen-substituted alkyl groups such as chloromethyl group, 3-chloropropyl group and 3,3,3-trifluoropropyl group are mentioned, and in particular, methyl group and vinyl. It is preferably a group.

The content of the alkenyl group bonded to the silicon atom in the component (H) is 0 to 10 mol with respect to the entire monovalent organic group bonded to the silicon atom (that is, the unsubstituted or substituted monovalent hydrocarbon group). %, Especially preferably about 2 to 8 mol%.

The organopolysiloxane resin of the component (H) preferably contains _3/2 units of R ⁸ SiO and / or _4/2 units of SiO, and the total amount thereof is 20 to 20 in the organopolysiloxane resin of the component (H). It is preferably 75 mol%, particularly preferably 30 to 60 mol%.
Here, as described above, the organopolysiloxane resin of the component (H) may optionally contain R ⁸ ₃ SiO _1/2 unit and / or R ⁸ ₂ SiO _2/2 unit. The total content is preferably 0 to 70 mol%, particularly 0 to 50 mol% in the organopolysiloxane resin of the component (H).
When the total amount of R ⁸ SiO _3/2 unit and / or SiO _4/2 unit in the organopolysiloxane resin of the component (H) is in the range of 20 to 75 mol%, a sufficient flame retardancy improving effect is obtained. Obtained and suitable.

Further, the polystyrene-equivalent weight average degree of polymerization (weight average molecular weight) in GPC (gel permeation chromatography) analysis using toluene of the organopolysiloxane resin as the component (H) as a developing solvent is 2,000 to 50,000, in particular. , 4,000 to 20,000 is preferable. When the weight average degree of polymerization is in the range of 2,000 to 50,000, a sufficient flame retardancy improving effect is obtained, and the viscosity of the liquid silicone rubber coating agent composition having good coating workability is obtained.

Specific examples of the organopolysiloxane resin of the component (H) include the siloxane unit represented by the formula: _R'3 SiO _1/2 and the formula: _R'2 R "siloxane unit represented by the SiO _1/2 and the formula: R. ' ₂ Organosiloxane copolymer consisting of a siloxane unit represented by SiO _2/2 and a formula: a siloxane unit represented by SiO _4/2 , formula: _R'3 A siloxane unit represented by SiO _1/2 and a formula: R ' ₂ R "Organosiloxane copolymer consisting of a siloxane unit represented by SiO _1/2 and a siloxane unit represented by the formula: SiO _4/2 , a siloxane unit represented by the formula: _R'2 R" SiO _1/2 . And formula: an organosiloxane copolymer consisting of a siloxane unit represented by _R'2 SiO _2/2 and a siloxane unit represented by formula: SiO _4/2 , formula: siloxane represented by formula: R'R "SiO _2/2 . Unit and formula: Organosiloxane copolymer consisting of a siloxane unit represented by R'SiO _3/2 or formula: siloxane unit represented by R "SiO _3/2 , and two or more of these organopolysiloxanes. Examples include mixtures.

R'in the above formula is a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, which is the same as or different from each other, other than the alkenyl group, and an example thereof is a methyl group. Alkyl groups such as ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group and heptyl group; aryl groups such as phenyl group, trill group, xylyl group and naphthyl group; aralkyl groups such as benzyl group and phenethyl group Examples thereof include an alkyl halide group such as a chloromethyl group, a 3-chloropropyl group and a 3,3,3-trifluoropropyl group, and a methyl group is particularly preferable. Further, R "in the above formula is an alkenyl group, and examples thereof include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group and the like, but a vinyl group is particularly preferable.

The blending amount of the component (H) can be 0.1 to 100 parts by mass, preferably 1 to 95 parts by mass, and 2 to 2 to 100 parts by mass with respect to 100 parts by mass of the organopolysiloxane of the component (A). It is particularly preferably 90 parts by mass. When the blending amount is in the range of 0.1 to 100 parts by mass, a sufficient flame retardancy improving effect can be obtained, and the cost effectiveness is also excellent.

When the component (H) contains an alkenyl group, the amount of SiH groups contained in the composition is 1 to 10 mol per 1 mol of the total silicon atom-bonded alkenyl groups contained in the composition. For example, the component (H) is the component (B) and the component (B) with respect to a total of 1 mol of the silicon atom-bonded alkenyl groups contained in the component (A), the component (E), the component (F) and the component (H) in the composition. (E) The amount of SiH groups contained in the component is 1 to 10 mol (or pieces), preferably 1.2 to 9 mol (or pieces), and more preferably 1.5 to 8 mol (or pieces). Is preferable.

Further, when the component (A), the component (E), the component (F) and the component (H) including the alkenyl group and the like are used in combination, the total number of alkenyl groups of each component in the composition is totaled. It can be blended in consideration of the ratio of the total number of moles of SiH groups to 1 mole.
For example, a silica fine powder of the component (C), which has been directly surface-hydrophobicized with a surface treatment agent containing an alkenyl group in a powder state in advance, is used, and the component (H) contains an alkenyl group and is used. When the component (F) contains an alkenyl group and the component (E) contains an alkenyl group and / or a SiH group, the component (A), the component (C), the component (E), and the component (F) in the composition. And the total of SiH groups contained in the component (B) and the component (E) is 1 to 10 mol, preferably 1 to 10 mol, relative to a total of 1 mol of the silicon atom (or nitrogen atom) bonded alkenyl groups contained in the component (H). The amount is preferably 1.2 to 9 mol, more preferably 1.5 to 8 mol.
This is because, similarly to the above, if the total amount of SiH groups is less than 1 mol with respect to the total of 1 mol of silicon atom-bonded alkenyl groups in the composition, the composition does not sufficiently cure and has sufficient adhesive strength. This is because it may not be expressed, and on the other hand, if the SiH group exceeds 10 mol, the heat resistance of the obtained cured silicone rubber product may be extremely inferior.

The three-dimensional network organopolysiloxane resin of the component (H) can be used alone or in combination of two or more.

-Reaction control agent The reaction control agent is not particularly limited as long as it is a compound having a curing inhibitory effect on the hydrosilylation reaction catalyst of the component (D), and known ones can be used. Specific examples thereof 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; and two or more alkenyl groups. Compounds; hydroperoxy compounds; maleic acid derivatives and the like can be mentioned.

Since the degree of the curing inhibitory effect of the reaction control agent varies depending on the chemical structure of the reaction control agent, it is preferable to adjust the addition amount of the reaction control agent to an optimum amount for each of the reaction control agents to be used. By adding the optimum amount of the reaction control agent, the composition becomes excellent in long-term storage stability and curability at room temperature.

-Non-reinforcing filler As a filler other than the silica fine powder of the component (C), for example, crystalline silica (for example, quartz powder having a BET method specific surface area of less than 50 m ² / g), an organic resin hollow filler, and poly. Methylsilsesquioxane fine particles (so-called silicone resin powder), fumed titanium dioxide, magnesium oxide, zinc oxide, iron oxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, zinc carbonate, carbon black, coconut soil, talc, kaolinite , Glass fiber and the like; Examples thereof include a filler obtained by surface-hydrophobicizing these fillers with an organic silicon compound such as an organoalkoxysilane compound, an organochlorosilane compound, an organosilazane compound and a low molecular weight siloxane compound.

-Other components In addition, for example, an organopolysiloxane containing one silicon atom-bonded hydrogen atom in one molecule and not containing other functional groups, and one silicon atom-bonded alkenyl group in one molecule. Organopolysiloxane containing, and containing no other functional groups, non-functional organopolysiloxane (so-called dimethylsilicone oil) containing no silicon atom-bonded hydrogen atom, silicon atom-bonded alkenyl group, or other functional group. Organic solvents, creep hardening inhibitors, plasticizers, thioxane-imparting agents, pigments, dyes, antifungal agents and the like can be blended.

<Preparation of Additive Curing Liquid Silicone Rubber Composition>
In addition to the above components (A) to (F), other components such as (G) and (H) components to be blended as necessary are uniformly mixed to prepare an addition-curable liquid silicone rubber composition. can do. The mixing of each raw material for preparing the additive-curable liquid silicone rubber composition for an air bag of the present invention can be carried out by using any known method and apparatus for producing the additive-curable liquid silicone rubber composition. .. Examples of devices that can be used include known kneading devices such as 2-roll, 3-roll, kneader mixer, and loss mixer.
The addition-curable liquid silicone rubber composition for an air bag thus obtained is a composition liquid at 25 ° C., and the viscosity at 25 ° C. measured by the method described in JIS K 7117-1: 1999 is 1-1, 1. It is preferably 000 Pa · s, more preferably 5 to 300 Pa · s. Within this viscosity range, when the base cloth for an air bag is coated, uneven coating and insufficient adhesive force to the base cloth after curing are unlikely to occur, so that the base cloth can be suitably used.

<Base cloth for air bag>
In the present invention, a known material is used as a base cloth (base material made of a fiber cloth) for an air bag on which a silicone rubber layer made of a cured product of the addition-curable liquid silicone rubber composition is formed. Examples include woven fabrics of various polyamide fibers such as 6,6-nylon and 6-nylon, and various synthetic fibers such as various polyester fibers such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT).

<Manufacturing method of air bag>
The addition-curable liquid silicone rubber composition is applied to at least one surface of a base cloth for an air bag (a base material made of a fiber cloth), particularly to one surface, and then heat-cured in a drying furnace or the like. A silicone rubber layer (cured product layer) can be formed. An air bag can be manufactured by using the silicone rubber-coated base cloth for an air bag thus obtained.

Here, as a method for coating the addition-curable liquid silicone rubber composition on the base cloth for an air bag, a conventional method can be adopted, but coating with a knife coater is preferable. The thickness (or surface coating amount) of the coating layer can be usually 5 to 100 g / m ² , preferably 8 to 90 g / m ² , and more preferably 10 to 80 g / m ² .

The addition-curable liquid silicone rubber composition can be cured by a known curing method under known curing conditions, whereby a cured film of the composition can be obtained. Specifically, for example, the composition can be cured by heating at 100 to 200 ° C. for 1 to 30 minutes.

When processing an air bag base cloth (silicone rubber coated base cloth for an air bag) having a silicone rubber layer (cured film) on at least one surface thus produced into an air bag, at least the inner surface of the air bag is processed. Examples thereof include a method in which the outer peripheral portions of two plain woven fabrics whose sides are coated with silicone rubber are bonded to each other with an adhesive, and the adhesive layers are sewn together. Further, as described above, the addition-curable liquid silicone rubber composition is coated on both outer sides of the air bag base fabric, which has been preliminarily woven in a bag, with a predetermined coating amount and cured under a predetermined curing condition. You may take the method. As the adhesive used here, known adhesives can be used, but a silicone-based adhesive called seam sealant is suitable in terms of adhesive strength and adhesive durability.

Hereinafter, the present invention will be specifically described with reference to Preparation Examples, Examples and Comparative Examples, but the present invention is not limited to the following Examples. The viscosity was measured with a rotary viscometer. Further, the part related to the composition means a mass part, and the room temperature means 25 ° C. Further, (A1) to (A5) are components (A), and (F1) to (F4) are components (F).

[Preparation Example 1]
Both ends of the molecular chain are sealed with vinyl dimethylsiloxy groups, the viscosity at 25 ° C. is 30,000 mPa · s, the average degree of polymerization is 750, 60 parts by mass of dimethylpolysiloxane (A1), 8 parts by mass of hexamethyldisilazane, water. 2 parts by mass and 40 parts by mass of silica fine powder (C) (Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.) having a specific surface area of 300 m ² / g by the BET method were put into a kneader and mixed at room temperature for 1 hour. After that, the temperature was raised to 150 ° C., and the mixture was continued for 2 hours. After that, the temperature is lowered to room temperature, both ends of the molecular chain are sealed with vinyldimethylsiloxy groups, and 25 parts by mass of dimethylpolysiloxane (A1) having a viscosity of 30,000 mPa · s at 25 ° C., a bifunctional constituent of the main chain. Of the sex diorganosiloxane units, 5 mol% of vinylmethylsiloxane units and 95 mol% of dimethylsiloxane units are contained, and both ends of the molecular chain are sealed with trimethylsiloxy groups, and the viscosity at 25 ° C. is 700 mPa · s, average polymerization. 5 parts by mass of dimethyl-vinylmethylpolysiloxane (A2) having a degree of 200 was added and mixed until uniform to obtain a base compound (1) (Table 1).

[Example 1]
The base compound (1) obtained in Preparation Example 1 has a viscosity of about 5,000 mPa · s and an average degree of polymerization of 450 in 150 parts by mass of the base compound (1). 10 parts by mass, viscosity of about 1,000 mPa · s, molecular chain double-ended vinyldimethylsiloxy group-blocked dimethylpolysiloxane (A4) with an average degree of polymerization of 200, 60.5 parts, viscosity of about 400 mPa · s. , 50 parts by mass of vinyldimethylsiloxy group-blocked dimethylpolysiloxane (A5) at both ends of the molecular chain having an average degree of polymerization of 160, a viscosity of 45 mPa · s at 25 ° C. as a cross-linking agent, and silicon atom-bonded hydrogen on the side chain of the molecular chain. Dimethylsiloxane / methylhydrogensiloxane copolymer (B) (silicon atom-bonded hydrogen atom content = 0.0108 mol / g) 14 parts by mass, γ-glycidoxypropyltri A dimethylpolysiloxane solution containing 0.56 parts of methoxysilane (E), 0.09 parts by mass of 1-ethynylcyclohexanol, and 1% by mass of a platinum chloride acid / 1,3-divinyltetramethyldisiloxane complex as a platinum atom content. (D) 0.45 parts by mass, (CH ₃ ) ₃ SiO _1/2 unit 39.5 mol% and (CH ₃ ) ₂ (CH ₂ = CH) SiO _1/2 unit 6.5 mol% and SiO _{4 /} Organopolysiloxane resin (H) (weight average molecular weight: 6,000) with a three-dimensional network structure consisting of ₂ units of 54 mol%, 10 parts by mass, tetraoctyl titanium (G) 0.34 parts by mass, Unilube C (F1) (Ethethylene oxide-propylene oxide copolymer, manufactured by Nichiyu Co., Ltd.) 0.30 parts by mass was mixed for 1 hour to prepare composition A (SiH group / vinyl group = 4.6 mol / mol, viscosity 80 Pa · s). did.

<Combustion rate test method>
The composition A was coated on a PET base cloth for an air bag (470 dtex) so that the coating amount was 20 to 25 g / m ² , and then cured in a dryer at 190 ° C./1 minute using a coating base cloth FMVSS. NO. The burning distance and burning time were measured by the method specified in 302. 10 tests were performed, and all 10 tests passed when the burning distance was 50 mm or less and the burning time was 60 seconds or less, or the burning distance ÷ burning time = burning speed was 102 mm / min or less. Table 3 shows the results of failure when the above conditions are not satisfied even once.

<Tear strength test method>
The composition A is coated on a PET base cloth (470 dtex) for an air bag so that the surface coating amount is 20 to 25 g / m ² , and then heat-cured at 190 ° C./1 minute in a dryer to obtain a silicone rubber cured product. A coated air bag base cloth was prepared. Then, the prepared air bag base cloth was cut into a size of 50 mm × 200 mm, and the tear test was measured 5 times by the method described in ISO 13937-2: 2000. The median values are shown in Table 3.

[Example 2]
Composition B in the same manner except that 0.30 parts by mass of Unilube C (F1) of Example 1 was replaced with 0.60 parts by mass of polyethylene glycol 300 (F2) (polyethylene glycol manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.). Table 3 shows the results of preparing (SiH group / vinyl group = 4.6 mol / mol, viscosity 78 Pa · s) and performing a combustion rate test and a tear test in the same manner as in Example 1.

[Example 3]
The composition is the same except that 0.30 parts by mass of Unilube C (F1) of Example 1 is replaced with 0.46 parts by mass of KF-6012 (F3) (polyether-modified polysiloxane manufactured by Shin-Etsu Chemical Co., Ltd.). Table 3 shows the results of preparing a substance C (SiH group / vinyl group = 4.6 mol / mol, viscosity 95 Pa · s) and performing a combustion rate test and a tear test in the same manner as in Example 1.

[Example 4]
Composition D (SiH group / vinyl) except that 0.30 part by mass of Unilube C (F1) of Example 1 was replaced with 2 parts by mass of n-octyl ether (F4) (manufactured by Tokyo Kasei Kogyo Co., Ltd.). Table 3 shows the results of preparing a group (group = 4.6 mol / mol, viscosity 60 Pa · s) and conducting a combustion rate test and a tear test in the same manner as in Example 1.

[Comparative Example 1]
The composition E (SiH group / vinyl group = 4.6 mol / mol, viscosity 45 Pa · s) was prepared in the same manner except that 0.30 part by mass of Unilube C (F1) of Example 1 was not blended. Table 3 shows the results of the combustion rate test and the tear test in the same manner as in Example 1.

[Comparative Example 2]
Composition F (SiH group / vinyl group = Table 3 shows the results of preparing 4.6 mol / mol and viscosity of 75 Pa · s) and conducting a combustion rate test and a tear test in the same manner as in Example 1.

Table 2 shows the blending amounts of the components used for Examples 1 to 4 and Comparative Examples 1 and 2.

From the above, in the case of the addition-curable silicone rubber composition for airbags of the present invention, FMVSS NO. It is excellent in low combustion speed property specified in 302 and also excellent in mechanical strength. On the other hand, Comparative Example 1 containing no component (F) is inferior in low combustion rate and mechanical strength, and is a comparison using a compound containing an adhesive-imparting functional group (epoxy group) even if it has an ether bond. Example 2 was inferior in mechanical strength.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and the present invention can be anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same function and effect. Is included in the technical scope of.

Claims (7)

Additive curable liquid silicone rubber composition for air bags.
(A) Organopolysiloxane having a degree of polymerization of 50 to 2,000 containing an alkenyl group bonded to two or more silicon atoms in one molecule: 100 parts by mass,
(B) Organohydrogenpolysiloxane containing a hydrogen atom (SiH group) bonded to at least two silicon atoms in one molecule: SiH group contained in the composition is a silicon atom bond contained in the composition. Amount of alkenyl groups totaling 1-10 mol per mol,
(C) BET method Silica fine powder having a specific surface area of 50 m ² / g or more: 1 to 50 parts by mass,
(D) Catalyst for hydrosilylation reaction: catalyst amount,
(E) Organosilicon compound containing an adhesive-imparting functional group: 0.1 to 10 parts by mass,
(F) An organic compound having at least one ether bond in one molecule and not containing an adhesive-imparting functional group: 0.1 to 10 parts by mass,
An addition-curable liquid silicone rubber composition for an air bag, which comprises. The air according to claim 1, wherein the adhesive-imparting functional group is one or more groups selected from an epoxy group, a silicon atom-bonded alkoxy group, a hydrosilyl group, an isocyanate group, an acrylic group, and a methacrylic group. Additive curable liquid silicone rubber composition for bags. Further, as the component (G), at least one condensation catalyst selected from an organic titanium compound, an organic zirconium compound, and an organoaluminum compound is added in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the component (A). The addition-curable liquid silicone rubber composition for an air bag according to claim 1 or 2, wherein the compound is contained. The one according to any one of claims 1 to 3, wherein the component (F) is a homopolymer or copolymer of ethylene oxide, propylene oxide, or tetrahydrofuran, or a dialkyl ether. Additive curable liquid silicone rubber composition for air bags. The addition-curable liquid silicone rubber composition for an air bag according to any one of claims 1 to 3, wherein the component (F) is a polyether-modified polysiloxane. Further, as the component (H), a powdery three-dimensional network-like organopolysiloxane resin (however, the organopolysiloxane resin does not contain a silicon atom-bonded hydrogen atom in the molecule) is used as the component (A) by 100 mass. The addition-curable liquid silicone rubber composition for an air bag according to any one of claims 1 to 5, wherein the content is 0.1 to 100 parts by mass with respect to parts. An air bag comprising a cured film of the addition-curable liquid silicone rubber composition for an air bag according to any one of claims 1 to 6 on a base cloth for an air bag.