JP5170433B2 - Liquid silicone rubber coating composition for air bag, air bag and method for producing the same - Google Patents

Description

  The present invention relates to a liquid silicone rubber coating agent composition for an air bag. More specifically, the present invention relates to an air bag for a vehicle or the like in which a silicone rubber coating film is formed on a fiber cloth such as 6,6 nylon, 6 nylon, and polyester. Airbags installed in the driver's seat and passenger seat, and stored along the roof side from the front pillar, to maintain a constant inflation time of the airbag to protect the head and prevent popping out in the event of a collision or vehicle falling The present invention relates to a liquid silicone rubber coating composition that is effective for producing curtain air bags that require a high pressure, an air bag having a rubber coating layer of a cured product of the composition, and a method for producing the same.

  The airbag has been developed as an airbag system for mitigating the impact on the passenger at the time of a side collision or preventing the passenger from being thrown out of the vehicle when the vehicle rolls over. This air bag needs to maintain the gas pressure (internal pressure) generated by the explosion of the inflation agent for a certain period of time during deployment, and requires a coating agent with lower viscosity / adhesiveness than conventional coating agents. Has been.

  The following are known as silicone rubber compositions for airbags intended to form a rubber coating on the fiber surface.

  For example, Japanese Patent No. 3945082 (Patent Document 1) discloses a coating composition having only wet silica, and Japanese Patent Laid-Open No. 5-25435 (Patent Document 2) describes an organosilicon compound having an epoxy group. Japanese Patent No. 98579 (Patent Document 3) discloses a coating composition using an organosilicon compound having an isocyanate group as an adhesive component. In Japanese Patent Application Laid-Open No. 5-214295 (Patent Document 4), silicone for an air bag having excellent adhesion to a base fabric, which is obtained by adding an inorganic filler, a siloxane resin, and an epoxy group-containing silicon compound to an addition-curable composition. A rubber composition is disclosed. In JP 2002-138249 A (Patent Document 5), an addition filler composition is added with an inorganic filler, a siloxane resin, an organic titanium compound, and an alkyl silicate. A silicone rubber composition for an air bag from which a cured product having excellent properties can be obtained is disclosed.

  However, these compositions, when used for air bag applications, did not sufficiently satisfy the low viscosity required for air bag coating and the adhesion to an air bag base fabric.

Japanese Patent No. 3945082 Japanese Patent Laid-Open No. 5-25435 Japanese Patent Laid-Open No. 5-98579 JP-A-5-214295 JP 2002-138249 A

  The present invention has been made in view of the above circumstances, and is a liquid silicone rubber coating agent composition excellent in low viscosity required for air bag coating and adhesion to an air bag base fabric, and the composition It is an object of the present invention to provide an airbag in which a silicone rubber coating layer made of the cured product is formed on at least one surface of a substrate and a method for producing the airbag.

As a result of intensive studies to achieve the above object, the present inventors have found that (A) an organopolysiloxane containing an alkenyl group bonded to two or more silicon atoms in one molecule, (B) in one molecule An organohydrogenpolysiloxane containing at least two silicon-bonded hydrogen atoms, (C) an addition reaction catalyst, (D) a specific surface area according to the BET method of 100 to 200 m ² / g and an average particle diameter of 20 μm or less, seen containing 20 to 80 wt% precipitated silica Na ion content is 0.35 wt% as Na ₂ O, with the others the specific surface area due to all the BET method average 300~400m ² / g Fine silica with a certain fumed silica (total 100% by mass) , (E) an organosilicon compound having an epoxy group and a silicon-bonded alkoxy group in one molecule, and (F ) When a liquid silicone rubber coating composition containing a specific amount of an organometallic compound selected from one or both of a titanium compound and a zirconium compound is used for a rubber coating layer of an air bag, the coating layer is air It has been found that the inflator gas can be prevented from leaking and the inflation of the airbag can be maintained for a certain period of time because of its low viscosity required at the time of bag coating and excellent adhesion to the airbag fabric. .

That is, this invention provides the liquid silicone rubber coating agent composition for airbags shown below, an airbag, and its manufacturing method.
[1] (A) 100 parts by mass of an organopolysiloxane containing an alkenyl group bonded to two or more silicon atoms in one molecule;
(B) Organohydrogenpolysiloxane containing at least two silicon-bonded hydrogen atoms in one molecule
The number of hydrogen atoms bonded to silicon atoms contained in this component is (A)
An amount of 1 to 10 per silicon-bonded alkenyl group in the minute,
(C) addition reaction catalyst effective amount,
(D) Precipitated silica having an average specific surface area by BET method of 100 to 200 m ² / g, an average particle diameter of 20 μm or less, and Na ion content of 0.35% by mass or less as Na ₂ O is 20 to 20 80 wt% seen including, otherwise the specific surface area by all the BET method and fumed silica is an average 300~400m ² / g (total 100 wt%) finely divided silica 50 parts by weight,
(E) 0.1 to 10 parts by mass of an organosilicon compound having an epoxy group and a silicon atom-bonded alkoxy group in one molecule;
(F) An organometallic compound selected from either one or both of a titanium compound and a zirconium compound, 0.01 to 5 parts by mass, and a liquid silicone rubber coating composition for an air bag.
[2] The liquid silicone rubber coating composition according to [1], wherein the average particle size of precipitated silica in component (D) is 0.01 to 20 μm.
[3] Liquid silicone rubber coating composition according to [1] or [2], wherein in component (D), precipitated silica is 30 to 70% by mass, and all other components are fumed silica (total 100% by mass) object.
[4] The liquid according to any one of [1] to [3], which is used for coating an airbag using a woven fabric of synthetic fiber selected from 6,6 nylon, 6 nylon, polyester fiber and aramid fiber Silicone rubber coating composition.
[ 5 ] A silicone rubber coating layer made of a cured product of the liquid silicone rubber coating composition according to any one of [1] to [ 4 ] is formed on at least one surface of a substrate made of a fiber cloth. Air bag.
[ 6 ] The liquid silicone rubber coating agent composition according to any one of [1] to [ 4 ] is applied to at least one surface of a substrate made of a fiber cloth and cured, whereby at least the substrate A method of manufacturing an airbag, comprising forming a silicone rubber coating layer on one surface.

  According to the present invention, a liquid silicone rubber coating agent composition having a low viscosity required for air bag coating and excellent adhesion to an air bag base fabric is obtained, and a silicone rubber comprising a cured product of the composition An airbag in which a coating layer is formed on at least one surface of a substrate suppresses inflator gas leakage and satisfies the sustainability of the expansion time.

The organopolysiloxane of component (A) is the main component (base polymer) of this composition, and contains 2 or more (usually 2 to 50), preferably about 2 to 20 silicon atoms in one molecule. Those containing a bonded alkenyl group, preferably those represented by the following average composition formula (1) are used.
R _a SiO _{(4-a) / 2} (1)
(In the formula, R is an identical or different monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and a is 1.5 to 2.8, preferably 1. (It is a positive number in the range of 8 to 2.5, more preferably 1.95 to 2.05, still more preferably 1.98 to 2.01.)

  Examples of the alkenyl group bonded to the silicon atom in the component (A) (R in formula (1)) include, for example, a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a pentenyl group, and a hexenyl group. , Cyclohexenyl group, heptenyl group and the like, usually those having 2 to 8 carbon atoms, preferably about 2 to 4 carbon atoms, and particularly preferably a vinyl group.

  Examples of the position of the silicon atom to which the alkenyl group in the polysiloxane skeleton of the component (A) is bonded include the molecular chain terminal and / or the molecular chain halfway (non-terminal molecular chain). As the component (A), A linear diorganopolysiloxane containing alkenyl groups bonded to silicon atoms at both ends of the molecular chain is preferred.

  In addition, the content of the alkenyl group in the component (A) is a monovalent organic group bonded to a silicon atom (that is, an unsubstituted or substituted monovalent hydrocarbon represented by R in the average composition formula (1)). Group) is preferably about 0.001 to 10 mol%, particularly about 0.01 to 5 mol%, based on the whole.

  (A) As an organic group couple | bonded with silicon atoms other than the alkenyl group of component (R of Formula (1)), for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl Group, pentyl group, hexyl group, cyclohexyl group, heptyl group and other alkyl groups; phenyl group, tolyl group, xylyl group, naphthyl group and other aryl groups; benzyl group, phenethyl group and other aralkyl groups; chloromethyl group, 3- An unsubstituted or halogen-substituted monovalent hydrocarbon group usually having 1 to 12 carbon atoms, preferably about 1 to 10 carbon atoms, such as a halogenated alkyl group such as a chloropropyl group and a 3,3,3-trifluoropropyl group. In particular, a methyl group and a phenyl group are preferable.

  Examples of the molecular structure of the component (A) include linear, cyclic, and branched chains, and the main chain is basically composed of repeating diorganosiloxane units, and both ends of the molecular chain are tricyclic. A linear diorganopolysiloxane blocked with an organosiloxy group is preferred (the organo group herein may also include an alkenyl group).

  The viscosity of component (A) at 25 ° C. is within the range of 100 to 500,000 mPa · s because the physical properties of the resulting silicone rubber are good and the workability of the composition is good. It is preferable that it is within a range of 300 to 100,000 mPa · s. In the present invention, the viscosity can be measured with a rotational viscometer (the same applies hereinafter).

Examples of the organopolysiloxane of the component (A) include, for example, a trimethylsiloxy group-capped dimethylsiloxane / methylvinylsiloxane copolymer, a molecular chain both-ends trimethylsiloxy group-capped methylvinylpolysiloxane, and both molecular chains. Terminal trimethylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer, molecular chain both ends trimethylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane / diphenylsiloxane copolymer, molecular chain both ends dimethylvinylsiloxy group-blocked dimethyl Polysiloxane, dimethylvinylsiloxy group-capped methylvinylpolysiloxane at both molecular chains, dimethylvinylsiloxy group-capped dimethylsiloxane / methylvinylsiloxane copolymer, molecule Dimethylsiloxane siloxy group-blocked dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer, dimethylvinylsiloxy group-blocked dimethylsiloxane / diphenylsiloxane copolymer at both ends, dimethylvinylsiloxy group-blocked dimethylsiloxane at both ends・ Methylphenylsiloxane copolymer, molecular chain both ends dimethylvinylsiloxy group-blocked dimethylsiloxane ・ Methylvinylsiloxane ・ Diphenylsiloxane copolymer, molecular chain both ends divinylmethylsiloxy group-blocked dimethylpolysiloxane, molecular chain both ends divinylmethylsiloxy Base-blocked dimethylsiloxane / methylvinylsiloxane copolymer, molecular chain both ends trivinylsiloxy group-blocked dimethylpolysiloxane, molecular chain both ends trivinylsiloxy group-blocked di Chill-methylvinyl siloxane copolymer, wherein: the siloxane units represented by R ¹ ₃ SiO _0.5 and formula siloxane units of the formula R ^{1 ₂} R ₂ SiO _0.5: and siloxane units represented by R ¹ ₂ SiO Organosiloxane copolymer comprising a siloxane unit represented by the formula: SiO ₂ , Organosiloxane copolymer comprising a siloxane unit represented by the formula: R ¹ ₂ R ² SiO _0.5 and a siloxane unit represented by the formula: SiO ₂ , Formula : An organosiloxane copolymer composed of a siloxane unit represented by R ¹ ₃ SiO _0.5 and a siloxane unit represented by formula: R ¹ ₂ R ² SiO _0.5 and a siloxane unit represented by formula: SiO ₂ , formula: R ¹ ₂ R ² A siloxane unit represented by SiO _0.5 and a siloxane unit represented by the formula: R ¹ ₂ SiO and a siloxane unit represented by the formula: SiO ₂ An organosiloxane copolymer comprising a siloxane unit represented by the formula: R ¹ R ² SiO and a siloxane unit represented by the formula: R ¹ SiO _1.5 or a siloxane unit represented by the formula: R ² SiO _1.5 And a mixture of two or more of these organopolysiloxanes.

R ¹ in the above formula is an unsubstituted or substituted monovalent hydrocarbon group other than an alkenyl group, and examples of the organic group R described above as an unsubstituted or halogen-substituted monovalent hydrocarbon group other than an alkenyl group Examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group and heptyl group; aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group Groups: aralkyl groups such as benzyl group and phenethyl group; halogenated alkyl groups such as chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group and the like. R ² in the above formula is an alkenyl group, such as vinyl group, allyl group, propenyl group, isopropenyl group, isobutenyl group, cyclohexenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, etc. Usually, those having 2 to 8 carbon atoms, preferably about 2 to 4 carbon atoms are mentioned. The alkenyl group-containing organopolysiloxane (A) can be used alone or in combination of two or more.

  The (B) component organohydrogenpolysiloxane reacts with the (A) component and acts as a cross-linking agent, and there is no particular limitation on its molecular structure, for example, linear, cyclic, branched, which has been conventionally produced. Various types such as a shape or a three-dimensional network (resin-like) can be used, but hydrogen atoms (hydrosilyl group represented by SiH) bonded to at least 2, preferably 3 or more silicon atoms in one molecule In general, it is desirable to have about 2 to 300, preferably 3 to 200, more preferably about 4 to 100 SiH groups.

As the organohydrogenpolysiloxane, those represented by the following average composition formula (2) can be used.
R ³ _b H _c SiO _{(4-bc) / 2} (2)

In the above formula (2), R ³ is, excluding aliphatic unsaturated bonds, preferably substituted or unsubstituted monovalent hydrocarbon group bonded 1 to 10 carbon atoms, a silicon atom, in the R ³ As the unsubstituted or substituted monovalent hydrocarbon group, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, Alkyl groups such as octyl group, nonyl group, decyl group, aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, aralkyl groups such as benzyl group, phenylethyl group, phenylpropyl group, and hydrogens of these groups Those in which some or all of the atoms are substituted with halogen atoms such as fluorine, bromine and chlorine, such as chloromethyl group, chloropropyl group, bromoethyl group, And halogen-substituted alkyl groups such as a fluoropropyl group. The unsubstituted or substituted monovalent hydrocarbon group for R ³ is preferably an alkyl group or an aryl group, and more preferably a methyl group or a phenyl group. B is 0.7 to 2.1, c is 0.001 to 1.0, and b + c is a positive number satisfying 0.8 to 3.0. Preferably, b is 1.0 to 1.0. 2.0 and c are 0.01 to 1.0, and b + c is 1.5 to 2.5.

  The SiH group contained in at least 2, preferably 3 or more in one molecule may be located at either the molecular chain end or in the middle of the molecular chain, or may be located at both of them. The molecular structure of the organohydrogenpolysiloxane may be any of linear, cyclic, branched, and three-dimensional network structures, but the number of silicon atoms in one molecule (or the degree of polymerization) is usually 2. ~ 300, preferably 3 to 200, more preferably about 4 to 150, and a viscosity at 25 ° C. is usually 0.1 to 1,000 mPa · s, preferably 0.5 to 500 mPa -About s, a liquid thing is used at room temperature (25 degreeC).

Examples of the component (B) organohydrogenpolysiloxane 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-blocked methylhydrogenpolysiloxane, molecular chain trimethyl at both ends Siloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane / methylphenylsiloxane copolymer at both ends of the molecular chain Molecular chain both ends trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane / diphenylsiloxane copolymer, molecular chain both ends dimethylhydrogensiloxy group-blocked methylhydrogenpolysiloxane, molecular chain both ends dimethylhydrogensiloxy group-blocked dimethylpoly Siloxane, dimethylhydrogensiloxy group-capped dimethylsiloxane / methylhydrogensiloxane copolymer, both ends of molecular chain dimethylhydrogensiloxy group-capped dimethylsiloxane / methylphenylsiloxane copolymer, dimethylhydrogen, both ends of molecular chain Siloxy group-blocked dimethylsiloxane / diphenylsiloxane copolymer, molecular chain both ends dimethylhydrogensiloxy group-blocked methylphenylpolysiloxane, molecule Both terminals and dimethylhydrogensiloxy group-blocked diphenyl polysiloxane, in each of these exemplified compounds, those in which a part of the methyl group or entirely substituted with other alkyl groups such as ethyl group, a propyl group, the formula: R ³ ₃ An organopolysiloxane copolymer comprising a siloxane unit represented by SiO _0.5 and a siloxane unit represented by the formula: R ³ ₂ HSiO _0.5 and a siloxane unit represented by the formula: SiO ₂ , a siloxane represented by the formula: R ³ ₂ HSiO _0.5 Organopolysiloxane copolymer comprising siloxane units represented by units and formula: SiO ₂ , siloxane units represented by formula: R ³ HSiO and siloxane units represented by formula: R ³ SiO _1.5 or represented by formula: HSiO _1.5 Organopolysiloxane copolymers comprising siloxane units, and these organopolysiloxanes The mixture which consists of 2 or more types of xane is mentioned. R ³ in the above formula is a monovalent hydrocarbon group other than an alkenyl group, and the same groups as described above are exemplified.

  (B) The compounding quantity of a component is 1-10 mol (or piece) of silicon atom bond hydrogen atoms in (B) component with respect to 1 mol (or piece) of silicon atom bond alkenyl groups in (A) component, In particular, the amount is preferably in the range of 1 to 5 moles (or pieces). When the number of silicon-bonded hydrogen atoms in component (B) is less than 1 mole relative to 1 mole of silicon-bonded alkenyl groups in component (A), the composition will not cure sufficiently, When it exceeds, the heat resistance of the silicone rubber obtained will be extremely inferior. The (B) component organohydrogenpolysiloxane can be used alone or in combination of two or more.

  As the addition reaction catalyst for component (C), any catalyst can be used as long as it promotes the hydrosilylation addition reaction between the silicon-bonded alkenyl group in component (A) and the SiH group in component (B). Also good. For example, platinum, palladium, rhodium, etc., chloroplatinic acid, alcohol-modified chloroplatinic acid, coordination compounds of chloroplatinic acid and olefins, vinyl siloxane or acetylene compounds, tetrakis (triphenylphosphine) palladium, chlorotris (triphenylphosphine) ) A platinum group metal such as rhodium or a compound thereof is used, and a platinum group metal compound is particularly preferable.

  The compounding amount of the addition reaction catalyst is an effective amount (so-called catalyst amount), but usually in a ratio of 0.5 to 1,000 ppm as the mass of the catalytic metal element with respect to the total mass of the components (A) and (B). The ratio is preferably 1 to 500 ppm, more preferably 10 to 100 ppm. If the blending amount is too small, the addition reaction may be remarkably slow or may not be cured. If the blending amount is too large, the cost becomes high and uneconomical.

Wet silica (e.g., precipitated silica (e.g., precipitated silica (20) to 80% by mass, preferably 30 to 70% by mass, more preferably 40 to 60% by mass) in the fine powder silica of component (D) used in the present invention. Silica) synthesized by a wet manufacturing method such as precipitated silica) is generally used as a filler for silicone rubber, but in the present invention, it is suitable for coating applications, particularly for airbag fabrics. The specific surface area according to the BET method is 100 to 300 m ² / g on average and the average particle size (the primary particles of wet silica are very small and actually agglomerated, and the particle size of this secondary agglomerated soul is usually the average The particle size is 20 μm or less, and Na ions in silica are 0.35% by mass or less (ie, 0 to 0) as Na ₂ O. .35 mass%) is essential.

That is, when wet silica is used as the filler, the specific surface area by the BET method needs to be an average of 100 to 300 m ² / g. When it is less than 100 m ² / g, physical strength cannot be obtained, and when it exceeds 300 m ² / g, the viscosity of the composition increases. In the range of 100 to 300 m ² / g, it is possible to obtain an appropriate viscosity, and more characteristically, unlike the case where dry silica is used, the adhesive component which is the component (E) described later is completely different. Even if added, the thixotropy hardly increases, and the desired viscosity can be obtained without increasing the viscosity. Furthermore, in order to achieve a coating thickness of 10 to 150 μm, preferably 20 to 60 μm, which is desired for an air bag, it is necessary to select one having an average particle diameter of 20 μm or less, preferably 10 μm or less. The lower limit is not particularly limited, but is 0.01 μm or more, particularly 0.1 μm or more. Incidentally, the average particle diameter can usually be determined as a cumulative weight average diameter D ₅₀ (or median diameter) by a laser diffraction method.

In addition, when this composition is applied to a base fabric, flame retardancy is required as a function of the airbag. In general, wet silica is manufactured from sodium silicate, and it is well known that sodium ions remain as impurities. When these are blended and filled in the silicone composition, so-called flame retardancy is lowered. Therefore, in order to ensure the flame retardancy while maintaining the good characteristics peculiar to wet silica as described above, the sodium ion in silica is 0.35% by mass or less (0 to 0.35% by mass as Na ₂ O). %), Preferably 0.30% by mass or less (0 to 0.30% by mass).

  When the wet silica contained in the fine powder silica is less than 20% by mass, the viscosity of the composition increases. Moreover, when it exceeds 80 mass%, the adhesiveness with respect to the base fabric for airbags of a composition will fall.

As fine powder silica other than wet silica contained in 20 to 80% by mass, dry silica (dry silica, for example, silica synthesized by a dry production method such as fumed silica) is generally a silicone rubber. Although those which are used as filler, in the present invention, coatings applications, as being particularly adapted to the air bag fabric, the specific surface area (BET method) is 50 m ² / g or more, preferably 50 to 400 m ² / g, particularly preferably 100 to 300 m ² / g. Characteristically, it is completely different from the case where wet silica is used, and when an adhesive component (E), which will be described later, is added, thixotropy increases, accompanied by an increase in viscosity, but desired adhesiveness is obtained. Is. However, if the specific surface area is less than 50 m ² / g, satisfactory adhesiveness cannot be imparted.

  Such finely divided silica may be used as it is, but in order to give good fluidity to the composition of the present invention, methylchlorosilanes such as trimethylchlorosilane, dimethyldichlorosilane, and methyltrichlorosilane, dimethylpolysiloxane, hexa It is preferable to use a surface treated with an organosilicon compound such as hexaorganodisilazane such as methyldisilazane, divinyltetramethyldisilazane, and dimethyltetravinyldisilazane.

  (D) The compounding quantity of a component is 1-50 mass parts with respect to 100 mass parts of (A) component organopolysiloxane, and it is preferable to set it as 5-40 mass parts especially. If the blending amount is too small, the adhesiveness necessary for the present invention may not be obtained. If the blending amount is too large, the viscosity of the composition increases and the coating workability deteriorates.

  The component (E) is an organosilicon compound having an epoxy group and a silicon atom-bonded alkoxy group in one molecule, and this is an organosilicon compound having an epoxy group and a silicon atom-bonded alkoxy group in one molecule. Any organosilicon compound can be used, but from the viewpoint of adhesion development, it has at least one epoxy group and at least two silicon-bonded alkoxy groups, for example, silane, having 2 to 30 silicon atoms, It is preferably about 4 to 20 organosilicon compounds such as cyclic or linear siloxane.

  As this epoxy group, a silicon atom in the form of a glycidoxyalkyl group such as glycidoxypropyl group, an epoxy group-containing cyclohexylalkyl group such as 2,3-epoxycyclohexylethyl group, 3,4-epoxycyclohexylethyl group, etc. The silicon atom-bonded alkoxy group is preferably a trimethoxysilyl group, triethoxysilyl group, methyldimethoxysilyl group, ethyldimethoxysilyl group, methyldiethoxysilyl group, ethyldiethoxysilyl group. A trialkoxysilyl group such as alkyl dialkoxysilyl group is preferred.

  The component (E) is selected from functional groups other than epoxy groups and silicon-bonded alkoxy groups in one molecule, for example, alkenyl groups such as vinyl groups, (meth) acryloxy groups, and hydrosilyl groups (SiH groups). It may have at least one kind of functional group.

  Examples of such an organosilicon compound of component (E) include organosilicon compounds exemplified by the following chemical formula, mixtures of two or more thereof, or one or more partially hydrolyzed condensates thereof. Illustrated.

（式中、ｎは１〜１０の整数、ｍは０〜１００の整数、好ましくは０〜２０の整数、ｐは１〜１００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 formula, n is an integer of 1 to 10, m is an integer of 0 to 100, preferably an integer of 0 to 20, p is an integer of 1 to 100, preferably an integer of 1 to 20, and q is an integer of 1 to 10. (It is an integer.)

  (E) The addition amount of a component is 0.1-10 mass parts with respect to 100 mass parts of (A) component, Preferably it is 0.1-5 mass parts. Self-adhesiveness is not shown as it is less than 0.1 mass part, and the physical property of hardened | cured material will fall when it exceeds 10 mass parts.

  Component (F) is an organometallic compound selected from one or both of a titanium compound and a zirconium compound, and acts as a condensation promoter for promoting adhesion. Examples of such component (F) include organic titanates such as tetraisopropyl titanate and tetrabutyl titanate; diisopropoxy (acetylacetonate) titanium, diisopropoxy (ethylacetoacetate) titanium, tetraacetylacetonate titanium, Titanium-based condensation promoters such as organic titanium chelate compounds such as titanium tetraacetylacetate; organic zirconium esters such as zirconium tetrapropylate and zirconium tetrabutyrate; zirconium tributoxyacetylacetonate, zirconium butoxyacetylacetonate bisethylacetoacetate, Organic zirconium chelates such as zirconium tetraacetylacetonate; zirconium bis (2-ethylhexanoate) oxide, zirconium acetate Ruasetoneto (2-ethylhexanoate) zirconium condensation cocatalyst oxo zirconium compounds such as oxide can be exemplified.

  (F) The compounding quantity of a component is 0.01-5 mass parts with respect to 100 mass parts of (A) component, Preferably it is the range of 0.1-2 mass parts. Adhesiveness and airtightness fall that it is less than 0.01 mass part. When it exceeds 5 mass parts, the heat resistance of hardened | cured material will fall.

  In the composition of the present invention, as a component other than the above components (A) to (F), all conventionally known control agent compounds which are compounds having a curing inhibitory effect on the addition reaction catalyst are used. be able to. Such compounds include phosphorus-containing compounds such as triphenylphosphine, nitrogen-containing compounds such as tributylamine, tetramethylethylenediamine, and benzotriazole, sulfur-containing compounds, acetylenic compounds, compounds containing two or more alkenyl groups, hydroper Examples include oxy compounds and maleic acid derivatives. Since the degree of the curing delay effect by the control agent compound varies greatly depending on the chemical structure of the control agent compound, it is preferable to adjust the addition amount of the control agent compound to an optimum amount for each of the control agent compounds to be used. If the amount added is too small, long-term storage stability at room temperature may not be obtained. Conversely, if it is too large, curing may be hindered.

  Other optional components include, for example, crystalline silica, hollow filler, silsesquioxane, fumed titanium dioxide, magnesium oxide, zinc oxide, iron oxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, zinc carbonate, Surface treatment of inorganic fillers such as layered mica, carbon black, diatomaceous earth, and glass fibers, and organosilicon compounds such as organoalkoxysilane compounds, organochlorosilane compounds, organosilazane compounds, and low molecular weight siloxane compounds. A filler etc. are mentioned. Moreover, silicone rubber powder, silicone resin powder, etc. are mentioned.

  Furthermore, this composition includes, as long as the object of the present invention is not impaired, as other optional components such as non-functional organopolysiloxanes containing no silicon-bonded hydrogen atoms and alkenyl groups, organic solvents, creep hard Anti-ning agents, plasticizers, thixotropic agents, pigments, dyes, fungicides and the like can be blended.

  The liquid silicone rubber coating agent composition of the present invention can be prepared by mixing the above-mentioned components according to a conventional method, and the viscosity of the whole composition is not particularly limited, At 25 ° C., 10 to 400 Pa · s, preferably 30 to 300 Pa · s, more preferably 50 to 200 Pa · s can be used.

  The liquid silicone rubber coating composition thus obtained has a low viscosity required at the time of air bag coating and excellent adhesion to the air bag base fabric, thus protecting the head in the event of a collision or vehicle falling. It is suitable for producing an air bag that is required to maintain a constant inflating time in order to prevent popping out.

  In the present invention, a known structure is used as an air bag, particularly a curtain air bag, on which a silicone rubber coating layer is formed by the above composition. Specifically, 6, 6 nylon, 6 nylon, Adhering the outer peripheral parts of two plain weave base fabrics coated with rubber on the inner surface with an adhesive, based on a woven fabric of various synthetic fibers such as polyester fibers, aramid fibers, various polyamide fibers and various polyester fibers, and Examples include a type produced by stitching the adhesive layers (hereinafter abbreviated as a plain weave type) and a bag-woven type air bag in which a bag portion is formed by weaving.

  By applying the liquid silicone rubber coating agent composition to at least one surface, in particular, one surface of a substrate made of a fiber cloth, placing it in a hot air drying oven and curing it by heating to form a silicone rubber coating layer It can be used as a silicone rubber coated base fabric for air bags.

Here, as a base material which consists of fiber cloths, the base material which makes the base fabric the woven fabric of the various synthetic fibers mentioned above is mentioned. Moreover, as a method of coating the composition, a conventional method can be adopted, but the thickness (or surface coating amount) of the coating layer is, for example, 10 to 150 g / m ² , preferably 15 to 80 g / m. ² and more preferably about 20 to 60 g / m ² .

  Moreover, as a hardening method and conditions of the said coating agent composition, a well-known hardening method and conditions can be employ | adopted, It can usually be set as the hardening conditions for 1 to 10 minutes at 120-180 degreeC.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not restrict | limited to the following Example. In the following examples, the viscosity is a value measured with a rotational viscometer.

[Example 1]
Both ends of the molecular chain are blocked with a vinyldimethylsiloxy group, and 65 parts by mass of dimethylpolysiloxane having a viscosity at 25 ° C. of about 30,000 mPa · s, 8 parts by mass of hexamethyldisiloxane, 2 parts by mass of water, and BET method fumed silica measured specific surface area of about 300m ² / g (fumed silica, trade name: Aerosil (registered trademark) 300, Nippon Aerosil Co., Ltd.) 20 parts by mass and the specific surface area measured by the BET method of about 200 meters ² / 20 parts by weight of wet silica (precipitated silica, trade name: Nipsil (registered trademark) LP, manufactured by Tosoh Silica Co., Ltd.), which is g, was put into a kneader at room temperature and mixed for 1 hour to obtain a mixture. The mixture was heated to 150 ° C. and subsequently mixed for 2 hours. The mixture was cooled to room temperature, and 19 parts by mass of dimethylpolysiloxane having both molecular chain ends blocked with vinyldimethylsiloxy groups and a viscosity at 25 ° C. of about 30,000 mPa · s were added to the mixture. 5 parts by weight of dimethylpolysiloxane containing 5 mol% of vinylmethylsiloxane units with respect to all diorganosiloxane units and having both molecular chain ends blocked with trimethylsiloxy groups and having a viscosity at 25 ° C. of about 700 mPa · s Was added and mixed until uniform to obtain a base compound (I).

78 parts by mass of base compound (I), 35 parts by mass of dimethylpolysiloxane having both molecular chain ends blocked with vinyldimethylsiloxy groups and a viscosity at 25 ° C. of about 5,000 mPa · s, and both ends of the molecular chain are vinyl 15 parts by mass of dimethylpolysiloxane blocked with a dimethylsiloxy group and having a viscosity at 25 ° C. of about 1,000 mPa · s, 39.5 mol% of (CH ₃ ) ₃ SiO _1/2 units and (CH ₃ ) ₂ ( CH ₂ ═CH) 10 parts by mass of an organopolysiloxane resin composed of 6.5 mol% of SiO _1/2 units and 54 mol% of SiO ₂ units, the viscosity at 25 ° C. is 45 mPa · s, and silicon is present in the side chain of the molecular chain. Trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer with both ends of an atom-bonded hydrogen atom (content of silicon-bonded hydrogen atoms) = 1.08% by mass) 6.4 parts by mass, 1-ethynylcyclohexanol 0.09 parts by mass, dimethyl containing 1% by mass of chloroplatinic acid / 1,3-divinyltetramethyldisiloxane complex as platinum atom content A composition A was prepared by mixing 0.38 parts by mass of a polysiloxane solution, 0.3 parts by mass of γ-glycidoxypropyltrimethoxysilane, and 0.2 parts by mass of titanium tetra-2-ethylhexoxide.

The viscosity of composition A was evaluated with a rotational viscometer BH-7-20. The results are shown in Table 1. The composition A was coated on a nylon 66 fiber woven fabric (80 g / m ² ) and cured by heating in an oven at 170 ° C. for 1 minute. The resulting coated fabric was evaluated for adhesiveness by a Scott fir test. The results are shown in Table 1.

<Viscosity measurement>
Viscosity was evaluated with a rotational viscometer BH-7-20.
Pass: The case where the viscosity was 50 Pa · s or less was regarded as acceptable.
Fail: The case where the viscosity exceeded 50 Pa · s was regarded as rejected.
<Scott fir test>
The Scott fir test was conducted using a Scott fir tester. After the above-mentioned coated cloth was subjected to a padding test 500 times with a pressing force of 2 kgf, the peeling state of the silicone rubber coating thin film from the base cloth was confirmed with the naked eye. Evaluation was performed according to the following criteria. The results are shown in Table 1.
Pass: The case where there was no peeling of the coating film from the base fabric was determined to be acceptable.
Fail: A case where there was peeling of the coating film from the base fabric was regarded as rejected.

[Comparative Example 1]
Both ends of the molecular chain are blocked with a vinyldimethylsiloxy group, and 65 parts by mass of dimethylpolysiloxane having a viscosity at 25 ° C. of about 30,000 mPa · s, 8 parts by mass of hexamethyldisiloxane, 2 parts by mass of water, and BET method 40 parts by mass of dry silica (fumed silica, trade name: Aerosil (registered trademark) 300, manufactured by Nippon Aerosil Co., Ltd.) having a measured specific surface area of about 300 m ² / g is charged into a kneader at room temperature and mixed for 1 hour. To obtain a mixture. The mixture was heated to 150 ° C. and subsequently mixed for 2 hours. The mixture was cooled to room temperature, and 19 parts by mass of dimethylpolysiloxane having both molecular chain ends blocked with vinyldimethylsiloxy groups and a viscosity at 25 ° C. of about 30,000 mPa · s were added to the mixture. 5 parts by weight of dimethylpolysiloxane containing 5 mol% of vinylmethylsiloxane units with respect to all diorganosiloxane units and having both molecular chain ends blocked with trimethylsiloxy groups and having a viscosity at 25 ° C. of about 700 mPa · s And mixed until uniform to obtain a base compound (II).

78 parts by mass of base compound (II), both ends of the molecular chain are blocked with vinyldimethylsiloxy groups, 35 parts by mass of dimethylpolysiloxane having a viscosity at 25 ° C. of about 5,000 mPa · s, and both ends of the molecular chain are vinyl 15 parts by mass of dimethylpolysiloxane blocked with a dimethylsiloxy group and having a viscosity at 25 ° C. of about 1,000 mPa · s, 39.5 mol% of (CH ₃ ) ₃ SiO _1/2 units and (CH ₃ ) ₂ ( CH ₂ ═CH) 10 parts by mass of an organopolysiloxane resin composed of 6.5 mol% of SiO _1/2 units and 54 mol% of SiO ₂ units, the viscosity at 25 ° C. is 45 mPa · s, and silicon is present in the side chain of the molecular chain. Trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer with both ends of an atom-bonded hydrogen atom (containing silicon-bonded hydrogen atoms) 6.4 parts by mass), 0.09 parts by mass of 1-ethynylcyclohexanol, and 1% by mass of chloroplatinic acid / 1,3-divinyltetramethyldisiloxane complex as a platinum atom content. A composition B was prepared by mixing 0.38 parts by mass of a dimethylpolysiloxane solution, 0.3 parts by mass of γ-glycidoxypropyltrimethoxysilane, and 0.2 parts by mass of titanium tetra-2-ethylhexoxide. .
The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

[Comparative Example 2]
Both ends of the molecular chain are blocked with a vinyldimethylsiloxy group, and 65 parts by mass of dimethylpolysiloxane having a viscosity at 25 ° C. of about 30,000 mPa · s, 8 parts by mass of hexamethyldisiloxane, 2 parts by mass of water, and BET method 40 parts by weight of wet silica (precipitated silica, trade name: Nipsil (registered trademark) LP, manufactured by Tosoh Silica Co., Ltd.) having a measured specific surface area of about 200 m ² / g is charged into a kneader at room temperature and mixed for 1 hour. To obtain a mixture. The mixture was heated to 150 ° C. and subsequently mixed for 2 hours. The mixture was cooled to room temperature, and 19 parts by mass of dimethylpolysiloxane having both molecular chain ends blocked with vinyldimethylsiloxy groups and a viscosity at 25 ° C. of about 30,000 mPa · s were added to the mixture. 5 parts by weight of dimethylpolysiloxane containing 5 mol% of vinylmethylsiloxane units with respect to all diorganosiloxane units and having both molecular chain ends blocked with trimethylsiloxy groups and having a viscosity at 25 ° C. of about 700 mPa · s And mixed until uniform to obtain a base compound (III).

78 parts by mass of base compound (III), both ends of the molecular chain blocked with vinyldimethylsiloxy groups, 35 parts by mass of dimethylpolysiloxane having a viscosity at 25 ° C. of about 5,000 mPa · s, and both ends of the molecular chain are vinyl 15 parts by mass of dimethylpolysiloxane blocked with a dimethylsiloxy group and having a viscosity at 25 ° C. of about 1,000 mPa · s, 39.5 mol% of (CH ₃ ) ₃ SiO _1/2 units and (CH ₃ ) ₂ ( CH ₂ ═CH) 10 parts by mass of an organopolysiloxane resin composed of 6.5 mol% of SiO _1/2 units and 54 mol% of SiO ₂ units, the viscosity at 25 ° C. is 45 mPa · s, and silicon is present in the side chain of the molecular chain. A trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer with both ends of an atom-bonded hydrogen atom (including silicon-bonded hydrogen atoms) 6.4 parts by mass, 0.09 parts by mass of 1-ethynylcyclohexanol, and 1% by mass of chloroplatinic acid / 1,3-divinyltetramethyldisiloxane complex as platinum atom content A composition C is prepared by mixing 0.38 parts by mass of a dimethylpolysiloxane solution, 0.3 parts by mass of γ-glycidoxypropyltrimethoxysilane, and 0.2 parts by mass of titanium tetra-2-ethylhexoxide. did.
The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Claims (6)

(A) 100 parts by mass of an organopolysiloxane containing an alkenyl group bonded to two or more silicon atoms in one molecule;
(B) Organohydrogenpolysiloxane containing at least two silicon-bonded hydrogen atoms in one molecule
The number of hydrogen atoms bonded to silicon atoms contained in this component is (A)
An amount of 1 to 10 per silicon-bonded alkenyl group in the minute,
(C) addition reaction catalyst effective amount,
(D) Precipitated silica having an average specific surface area by BET method of 100 to 200 m ² / g, an average particle diameter of 20 μm or less, and Na ion content of 0.35% by mass or less as Na ₂ O is 20 to 20 80 wt% seen including, otherwise the specific surface area by all the BET method and fumed silica is an average 300~400m ² / g (total 100 wt%) finely divided silica 50 parts by weight,
(E) 0.1 to 10 parts by mass of an organosilicon compound having an epoxy group and a silicon atom-bonded alkoxy group in one molecule;
(F) An organometallic compound selected from either one or both of a titanium compound and a zirconium compound, 0.01 to 5 parts by mass, and a liquid silicone rubber coating composition for an air bag. The liquid silicone rubber coating composition according to claim 1, wherein the average particle size of precipitated silica in component (D) is 0.01 to 20 µm. The liquid silicone rubber coating composition according to claim 1 or 2, wherein in component (D), precipitated silica is 30 to 70% by mass, and all other components are fumed silica (total 100% by mass). The liquid silicone rubber coating according to any one of claims 1 to 3, wherein the liquid silicone rubber coating is used for coating an air bag based on a woven fabric of synthetic fibers selected from 6, 6 nylon, 6 nylon, polyester fibers and aramid fibers. Agent composition. The airbag by which the silicone rubber coating layer which consists of hardened | cured material of the liquid silicone rubber coating agent composition of any one of Claims 1-4 is formed in the at least one surface of the base material which consists of fiber cloths. The liquid silicone rubber coating agent composition according to any one of claims 1 to 4 is applied to at least one surface of a substrate made of a fiber cloth and cured to thereby cure at least one surface of the substrate. A method for producing an air bag, comprising forming a silicone rubber coating layer on the air bag.