JP6003866B2 - Silicone airbag manufacturing method and blocking resistance improving method - Google Patents

Description

  The present invention relates to a method for producing a silicone airbag having a rubber coating layer obtained by crosslinking and curing a liquid silicone rubber coating agent composition excellent in adhesion, blocking resistance, etc. to a base fabric composed of fibers and the like with an electron beam. More specifically, a method for producing a silicone airbag for crosslinking and molding a liquid silicone rubber coating composition by irradiating a total electron beam dose of 30 to 300 Mrad with an electron beam molding apparatus, and this method The present invention relates to a method for improving the blocking resistance of a silicone air bag produced by the method described above.

  Conventionally, silicone rubber-coated cloth intended to form a rubber film on the surface of a base fabric made of fibers, etc. has a sticky feeling peculiar to silicone rubber, so that workability at the time of cutting or sewing after coating remains. It was extremely bad. As an improvement measure, powder such as talc having excellent adhesion and slipping properties is dusted on the rubber surface. However, this method is expensive and has a risk of adversely affecting the human body due to dust. In addition, since the powder is simply adhered to the surface of the rubber-coated cloth, the powder is easily removed and the effect cannot be exhibited stably.

In order to solve these problems, the following compositions have been proposed. For example, an inorganic compound or an organic compound selected from the group consisting of aluminum hydroxide, mica, dimethylsilsesquioxane, carbon, polyamide, and polyfluorinated ethylene having an average particle size of 0.5 to 20 μm as the rubber coating composition A coating composition for a rubber coated fabric comprising the powder of (Patent No. 3379839: Patent Document 1); natural drying oil, modified natural drying oil, liquid diene compound or unsaturated fatty acid ester in the rubber coating composition A low-adhesive rubber-coated cloth coating composition obtained by adding a dry oil compound selected from the above (Japanese Patent Laid-Open No. 2000-191915: Patent Document 2); an average particle size of 10 to 300 μm in the rubber coating composition Aluminosilicate hollow powder, glass balloon, silica balloon, shirasu baloo Rubber coating with low adhesiveness on the surface of rubber coating film made by adding hollow powder such as carbon balloon, alumina balloon, plastic balloon, silicone resin hollow powder, alumina powder, glass powder, plastic powder, etc. Coating composition for cloth (Japanese Patent Laid-Open No. 2000-303022: Patent Document 3); wet silica having an average BET specific surface area of 150 to 250 m ² / g and an average particle diameter of 20 μm or less is added to the rubber coating composition Thus, a coating composition for rubber-coated cloth with reduced adhesiveness (Japanese Patent Application Laid-Open No. 2001-59052: Patent Document 4) has been proposed.
However, although all the compositions have improved workability after curing, while maintaining various properties such as adhesion to a base fabric made of fibers, rubber strength, etc., there is no stickiness, i.e., blocking resistance. The cured product was not satisfactory.

Therefore, as a means for improving the blocking resistance, a method for crosslinking the liquid silicone airbag was examined. The air bag base cloth is coated by spraying, dipping, bar coating, etc., set to an atmosphere of 50 to 500 ° C., and crosslinked by holding for about several seconds to 30 minutes by HAV molding with hot air (Hot Air Vulcanization), A coated fabric was prepared.
However, in the HAV molding at 50 to 300 ° C. with warm air, the cross-linked coated fabric is inferior in blocking resistance, and in the HAV molding at a high temperature exceeding 300 ° C., the blocking resistance is slightly good, but not enough. On the contrary, the phenomenon that the airbag base fabric is shrunk or twisted by heat occurs, and it is difficult to obtain an airbag having good blocking resistance.

Japanese Patent No. 3379839 JP 2000-191915 A JP 2000-303022 A JP 2001-59052 A

  The present invention has been made in view of the above circumstances, and is a simple method for producing an airbag having a rubber coating layer excellent in adhesion and blocking resistance to a base fabric made of fibers and the like, and improvement in blocking resistance. It is intended to provide a method.

  In order to achieve the above object, the present inventors have made various studies on the method of curing the rubber coating layer. As a result, when the liquid silicone rubber coating composition is crosslinked, an electron beam with a total electron beam dose of 30 to 300 Mrad is obtained. It was possible to crosslink in a short time by irradiating with the above, and it was found that the silicone rubber crosslinked by the above method was excellent in adhesion and blocking resistance, which led to the present invention. It is.

  The cured product of the liquid silicone rubber coating composition irradiated with an electron beam having a total electron beam dose of 30 to 300 Mrad has a better surface cross-linking property than a hot-air cross-linking (HAV cross-linking), no tackiness, and a short time. It is possible to crosslink the liquid silicone rubber coating composition with a low tack and a surface state with good blocking resistance.

Accordingly, the present invention provides a method for producing a silicone airbag and a method for improving anti-blocking properties described below.
[1]
On at least one surface of the base fabric,
(A) Organopolysiloxane containing at least two alkenyl groups bonded to a silicon atom in one molecule and no other functional group in the molecule: 100 parts by mass
(B) Adhesion improver (except (A)) : A liquid silicone rubber coating composition containing 0.1 to 10 parts by mass is applied and irradiated with a total electron beam dose of 30 to 300 Mrad. Thus, the liquid silicone rubber coating composition is cured by crosslinking with an electron beam.
[2]
(B) The adhesion improver is
(I) an organosilane having at least two kinds of functional groups, or a linear, cyclic or branched siloxane oligomer having 3 to 100 silicon atoms and having at least two kinds of functional groups,
Alkenyl group bonded to silicon atom, epoxy group bonded to silicon atom via carbon atom, acryloxy group or methacryloxy group bonded to silicon atom via carbon atom, alkoxysilyl group bonded to silicon atom via carbon atom , alkoxy groups bonded to silicon atoms, an ester structure, a urethane structure, ether structure, isocyanate group, and is selected from the group consisting of hydrogen atoms bonded to a silicon atom, an organosilane or at least two having at least two functional groups A linear, cyclic or branched siloxane oligomer having 3 to 100 silicon atoms and having a functional group of:
(Ii) a nitrogen-containing organosilicon compound selected from (alkoxy) silyl-modified products of triallyl isocyanurate and siloxane derivatives thereof,
(Iii) a non-silicon organic compound selected from organic acid allyl esters having at least one alkenyl group and at least one ester group in the molecule;
(Iv) an organic titanium compound,
as well as
(V) Organic zirconium compound
[1] The method for producing a silicone airbag according to [1], which is one or more selected from the group consisting of (i) to (v) .
[3]
(B) The adhesion improver is an organosilicon compound having an epoxy equivalent of 100 to 5,000 g / mol, a silicon atom-bonded alkenyl group and / or a silicon atom-bonded hydrogen atom and a silicon atom-bonded alkoxy group in each molecule. [2] The method for producing a silicone airbag according to [2], which is one or more selected from organic silicon compounds, organic titanium compounds, organic zirconium compounds, and nitrogen-containing organic silicon compounds.
[4]
The liquid silicone rubber coating composition further comprises an organohydrogenpolysiloxane which contains at least two hydrogen atoms bonded to silicon atoms in one molecule and does not contain other functional groups in the molecule [1. ] The manufacturing method of the silicone airbag in any one of-[3].
[5]
The method for producing a silicone airbag according to [4], wherein the liquid silicone rubber coating composition further contains an addition reaction catalyst.
[6]
The method for producing a silicone airbag according to any one of [1] to [5], wherein the liquid silicone rubber coating composition does not contain an organic solvent.
[7]
The method for producing a silicone airbag according to any one of [1] to [6], wherein the silicone airbag is a curtain airbag.
[8]
The method for producing a silicone airbag according to any one of [1] to [7], wherein the electron beam is irradiated with an electron beam forming apparatus.
[9]
The method to improve the blocking resistance of a silicone airbag which consists of manufacturing a silicone airbag by the method in any one of [1]-[8].

  The cured product obtained by crosslinking the liquid silicone rubber coating composition of the present invention with an electron beam having a specific electron beam dose not only has excellent adhesion to fibers and blocking resistance, but also has a rubber-specific stickiness. It is reduced and feels good, and it has excellent workability during sewing. In addition, the composition is excellent in coating properties, and is environmentally friendly because it can be used without being diluted in a solvent. An airbag having a rubber coating layer made of the cured product is less likely to peel off because the rubber coating layer is difficult to peel off, and is excellent in sustainability of the inflation time.

Hereinafter, the present invention will be described in detail.
<Liquid silicone rubber coating composition>
The liquid silicone rubber coating agent composition used in the present invention comprises the following components (A) and (B).

-(A) Organopolysiloxane-
The organopolysiloxane of component (A) is a component that becomes the main component (base polymer) of the liquid silicone rubber coating composition used in the present invention, and on average, at least two (usually 2 to 50) per molecule. Alkenyl group bonded to 2 to 20 silicon atoms (hereinafter referred to as “silicon atom-bonded alkenyl group”) and other functional groups in the molecule.

  The silicon-bonded alkenyl group usually has 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms. Specific examples thereof include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group, and a vinyl group is preferable.

  The bonding position of the silicon atom-bonded alkenyl group in the organopolysiloxane molecule may be the molecular chain terminal, the molecular chain non-terminal (ie, molecular chain side chain), or both. Good.

  In the organopolysiloxane molecule of this component, an organic group bonded to a silicon atom other than the silicon atom-bonded alkenyl group (hereinafter referred to as “silicon atom-bonded organic group”) does not have an aliphatic unsaturated bond. If it does not specifically limit, For example, the monovalent | monohydric hydrocarbon group etc. whose carbon atom number of unsubstituted or substituted is 1-12 normally, 1-10 are preferable. Examples of the unsubstituted or substituted monovalent hydrocarbon 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, and a heptyl group; a cycloalkyl group such as a cyclohexyl group; Aryl groups such as a group, tolyl group, xylyl group and naphthyl group; aralkyl groups such as a benzyl group and a phenethyl group; some or all of hydrogen atoms of these groups are halogen atoms such as a chlorine atom, a fluorine atom and a bromine atom Substituted halogenated alkyl groups such as chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group, etc. are mentioned, preferably alkyl group and aryl group, more preferably methyl group , A phenyl group.

  In this component, the content of the silicon-bonded alkenyl group is preferably 0.001 to 10 mol%, particularly preferably 0.01 to 5 mol%, based on all silicon-bonded organic groups in the component. is there.

  The molecular structure of the organopolysiloxane of this component is not particularly limited, and examples thereof include linear, partially branched linear, cyclic, branched, etc., but the main chain is basically a diorganosiloxane unit. It is preferably a linear diorganopolysiloxane having both ends of the molecular chain blocked with triorganosiloxy groups.

The viscosity of this component at 25 ° C. is preferably 100 to 500,000 mPa · s, because physical properties such as adhesion to cured fibers, rubber strength, and blocking resistance are more excellent. Particularly preferred is 300 to 100,000 mPa · s. In the present invention, the viscosity is a value measured with a rotational viscometer (for example, BL type, BH type, BS type, cone plate type) (hereinafter the same).
The alkenyl group-containing organopolysiloxane of component (A) usually has an average degree of polymerization of about 50 to 1,500, preferably about 100 to 1,100, for the same reason as above. In the present invention, the average degree of polymerization (or average molecular weight) is, for example, a weight average degree of polymerization (or weight average molecular weight) in gel permeation chromatography (GPC) analysis using toluene, tetrahydrofuran (THF) or the like as a developing solvent. (Hereinafter the same).

Examples of the organopolysiloxane of this component include the following average composition formula (1):
R ¹ _a R ² _b SiO _{(4-ab) / 2} (1)
(In the formula, R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, such as halogen substitution, R ² is an alkenyl group, and a is 1.7 to 2.1. The number b is a number from 0.00001 to 0.1, provided that a + b satisfies 1.8 to 2.2.
The thing represented by is mentioned.

In the average composition formula (1), the substituted monovalent hydrocarbon group having no aliphatic unsaturated bond represented by R ¹ , such as unsubstituted or halogen-substituted, usually has 1 to 12 carbon atoms, Preferably it is 1-10. Specific examples include those exemplified as the silicon-bonded organic groups other than the silicon-bonded alkenyl group and the like, 90 mol% or more of all the R ^1, be especially all of R ¹ is a methyl group preferable.

The alkenyl group represented by R ² usually has 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms. Specific examples thereof include those exemplified as the silicon atom-bonded alkenyl group.

  a is preferably a number of 1.9 to 2.0, b is preferably a number of 0.0001 to 0.05, and a + b is 1.95 to 2.05, particularly 1.98 to It is preferable to satisfy 2.02.

Specific examples of the organopolysiloxane of this component include a trimethylsiloxy group-capped dimethylsiloxane / methylvinylsiloxane copolymer with both ends of a molecular chain, a trimethylsiloxy group-capped methylvinylpolysiloxane with a molecular chain at both ends, and a trimethylsiloxy group with both ends of a molecular chain Blocked dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer, dimethylvinylsiloxy group blocked at both ends of molecular chain, dimethylvinylsiloxy group blocked at both ends of molecular chain, methylvinylpolysiloxane blocked at both ends of molecular chain, dimethylvinylsiloxy group at both ends of molecular chain Blocked dimethylsiloxane / methylvinylsiloxane copolymer, dimethylvinylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer, both ends of molecular chain Divinylmethylsiloxy group-blocked dimethylpolysiloxane, molecular chain both ends divinylmethylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane copolymer, molecular chain both ends trivinylsiloxy group-blocked dimethylpolysiloxane, molecular chain both ends trivinylsiloxy group-blocked Dimethylsiloxane / methylvinylsiloxane copolymer, siloxane unit represented by the formula: R ¹ ₃ SiO _1/2 (wherein R ¹ is as described above, the same shall apply hereinafter) and the formula: R ¹ ₂ R ² A siloxane unit represented by SiO _1/2 (wherein R ² is as defined above, the same shall apply hereinafter), a siloxane unit represented by the formula: R ¹ ₂ SiO and a small amount of formula: SiO ₂ organosiloxane copolymers consisting of that siloxane units of the formula: a siloxane unit of the formula represented by R ¹ ₃ SiO _1/2: represented by R ¹ ₂ R ² SiO _1/2 Siloxane units of the formula that organosiloxane copolymers consisting of siloxane units represented by SiO _2, wherein: the siloxane units of the formula represented by R ^{1 ₂} R ₂ SiO _1/2: represented by R ¹ ₂ SiO An organosiloxane copolymer consisting of a siloxane unit and a small amount of formula: siloxane unit represented by SiO ₂ ; a siloxane unit represented by formula: R ¹ R ² SiO and a small amount of formula: R ¹ SiO _3/2 Examples thereof include an organosiloxane copolymer comprising a siloxane unit represented by or a small amount of a formula: R ² SiO _3/2 , a mixture comprising two or more of these organopolysiloxanes, and the like.
The (A) component organopolysiloxane may be used alone or in combination of two or more.

-(B) Adhesion improver-
(B) Adhesion improver used in the present invention is a liquid silicone rubber coating agent composition for synthetic fiber woven fabric base materials, nonwoven fabric base materials, thermoplastic resin sheet-like base materials, or film-like base materials. It is a component for improving the adhesiveness of a cured product (rubber coating layer). This adhesive improvement agent will not be specifically limited if it can improve the self-adhesiveness of hardened | cured material. Specific examples thereof include an alkenyl group bonded to a silicon atom, an epoxy group bonded to a silicon atom via a carbon atom, an acryloxy group or a methacryloxy group bonded to a silicon atom via a carbon atom, and a silicon atom via a carbon atom. Organo having at least two functional groups selected from the group consisting of alkoxysilyl groups bonded to silicon, alkoxy groups bonded to silicon atoms, ester structures, urethane structures, ether structures, isocyanate groups, and hydrogen atoms bonded to silicon atoms Organosilicon compounds such as nitrogen-containing organosilicon compounds selected from silane and linear, cyclic or branched siloxane oligomers having 3 to 100 silicon atoms, (alkoxy) silyl modified products of triallyl isocyanurate and siloxane derivatives thereof Or at least one al in the molecule Non-silicon organic compounds selected from organic acid allyl esters having a nyl group and at least one ester group, organic titanium compounds, organic zirconium compounds, and the like are mentioned. Among them, at least one functional group is contained in one molecule. Those having two or more types are more preferable.

  Examples of the organic silicon compound include vinyl groups bonded to silicon atoms, alkenyl groups such as allyl groups; alkylene groups such as γ-glycidoxypropyl groups and β- (3,4-epoxycyclohexyl) ethyl groups. An epoxy group bonded to a silicon atom via a carbon atom; an acryloxy group or a methacryloxy group bonded to a silicon atom via a carbon atom such as an alkylene group such as a γ-acryloxypropyl group or a γ-methacryloxypropyl group; an alkylene Alkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, and methyldimethoxysilyl group bonded to silicon atoms via carbon atoms such as groups; directly to silicon atoms such as methoxy group, ethoxy group, propoxy group, and butoxy group Bonded alkoxy group; ester structure, urethane structure, ether structure, isocyanine An organosilane having at least two functional groups selected from the group consisting of a hydrogen atom bonded to a silicon atom and an organosilane having 3 to 100, preferably 3 to 50, more preferably 5 to 20, It is selected from linear, cyclic or branched siloxane oligomers, (alkoxy) silyl-modified products of triallyl isocyanurate, and siloxane derivatives (that is, hydrolysis condensates of alkoxysilyl-modified products of triallyl isocyanurate). Examples include organic silicon compounds such as nitrogen-containing organosilicon compounds, among which those having two or more functional groups in one molecule are preferable. However, a siloxane oligomer having only two or more silicon-bonded alkenyl groups on average among the functional groups exemplified above in the molecule (that is, those corresponding to the component (A)) is excluded.

Specific examples of such an organosilicon compound include the following compounds.

（上記式中、ｎ＝０〜１００の整数である。）

(In the above formula, n is an integer of 0 to 100.)

  When the adhesion improver of this component is an organosilicon compound having an epoxy group in the molecule as the functional group, the epoxy equivalent of the organosilicon compound is preferably 100 to 5,000 g / mol, more preferably Is 150 to 3,000 g / mol. When the epoxy equivalent satisfies this range, the composition has a good viscosity, and the cured product has better adhesiveness.

  Examples of the non-silicon organic compound include organic acid allyl esters having one alkenyl group and at least one ester group in one molecule. Examples of organic acids include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and vinyl acetic acid; aromatic carboxylic acids such as benzoic acid, phthalic acid, and pyromellitic acid; acetic acid, propionic acid, butyric acid, valeric acid, lauric acid, and the like Of saturated fatty acids. Examples of organic acid allyl esters containing these organic acids include, for example, allyl esters such as unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and vinyl acetic acid; benzoic acid allyl ester, phthalic acid diallyl ester, pyromellitic acid tetraallyl ester, and the like. Aromatic carboxylic acid allyl esters of the following: saturated fatty acid allyl esters such as acetic acid allyl ester, propionic acid allyl ester, butyric acid allyl ester, valeric acid allyl ester, lauric acid allyl ester, and the like.

  In addition, organic titanium compounds and organic zirconium compounds that act as condensation promoters for promoting adhesion can be used. Specific examples of the above components include titanium tetraisopropoxide, titanium tetranormal butoxide, titanium tetra- Organic titanates such as 2-ethylhexoxide and titanium tetraoctyl oxide (octyl titanate), titanium diisopropoxybis (acetylacetonate), titanium diisopropoxybis (ethylacetoacetate), titanium tetraacetylacetonate Titanium-based condensation promoters (titanium compounds) such as organic titanium chelate compounds, organic zirconium esters such as zirconium tetranormal propoxide, zirconium tetranormal butoxide, zirconium tributoxy monoacetate Ruasetoneto, zirconium monobutoxy acetylacetonate bis (ethylacetoacetate), zirconium and organic zirconium chelate compounds such as zirconium tetraacetyl acetonate condensation promoter (zirconium compounds). The said component may be used individually by 1 type, or may use 2 or more types together.

Among the above-described examples of the adhesion improver of this component, an organosilicon compound having an epoxy equivalent of 100 to 5,000 g / mol, a silicon atom-bonded alkenyl group and / or a silicon atom-bonded hydrogen atom and a silicon atom-bonded alkoxy An organosilicon compound having one or more groups per molecule, an organotitanium compound, an organozirconium compound, an organosilicon compound containing one or more nitrogen atoms in one molecule, or a combination thereof is preferable.
(B) The adhesive improvement agent of a component may be used individually by 1 type, or may use 2 or more types together.

  (B) The compounding quantity of a component needs to be 0.1-10 mass parts with respect to 100 mass parts of (A) component, Preferably it is 0.5-5 mass parts. When this blending amount is less than 0.1 parts by mass, the cured product may not have sufficient adhesiveness, and when this blending amount exceeds 10 parts by mass, the cost becomes high. It is uneconomical.

-Optional component-
In addition to the above components (A) and (B), the liquid silicone rubber coating agent composition of the present invention may contain the following components as necessary. These optional components may be used alone or in combination of two or more.

-Organohydrogenpolysiloxane-
The organohydrogenpolysiloxane is a component that acts as a crosslinking agent in the addition curing reaction with the component (A) and further imparts adhesiveness to the cured product. This organohydrogenpolysiloxane has an average of at least 2, preferably at least 3, more preferably an upper limit of 500, still more preferably an upper limit of 200, particularly preferably an upper limit of 100 per molecule. It has a hydrogen atom bonded to an atom (hereinafter referred to as “silicon atom-bonded hydrogen atom” (that is, SiH group or hydrosilyl group)) and does not contain other functional groups in the molecule, Does not have an aliphatic unsaturated bond.

  The bonding position of the silicon atom-bonded hydrogen atom in the organohydrogenpolysiloxane molecule of this component may be the molecular chain terminal, the molecular chain non-terminal, or both.

  In this organohydrogenpolysiloxane molecule, the silicon atom-bonded organic group other than the silicon atom-bonded hydrogen atom is not particularly limited, but has no aliphatic unsaturated bond, for example, unsubstituted or substituted carbon. Examples thereof include monovalent hydrocarbon groups having 1 to 10 atoms, preferably 1 to 6 atoms. Specific examples thereof include those exemplified as the silicon atom-bonded organic group other than the silicon atom-bonded alkenyl group in the description of the component (A).

  In this component, the content of the silicon atom-bonded hydrogen atoms is preferably 0.1 to 60 mol%, particularly preferably the total of all silicon atom-bonded organic groups and all silicon atom-bonded hydrogen atoms in the component. Preferably it is 1-50 mol%.

  The molecular structure of the organohydrogenpolysiloxane of this component is not particularly limited, and those conventionally produced can be used, for example, linear, cyclic, branched, three-dimensional network (resinous), etc. Linear or cyclic is preferable.

  The viscosity of this component at 25 ° C. is preferably 0.1 to 5,000 mPa · s because physical properties such as adhesion to cured fibers, rubber strength, and anti-blocking properties and workability are more excellent. A range that is liquid at room temperature (25 ° C.) satisfying a range of s, more preferably 0.5 to 1,000 mPa · s, particularly preferably 5 to 500 mPa · s is desirable. When satisfying such a viscosity, the number (or degree of polymerization) of silicon atoms in one molecule of organohydrogenpolysiloxane is usually 2 to 1,000, preferably 3 to 300, more preferably 4 to 150. It is.

Examples of the organohydrogenpolysiloxane of this component include the following average composition formula (2):
R ³ _c H _d SiO _{(4-cd) / 2} (2)
(Wherein R ³ is an unsubstituted or substituted monovalent hydrocarbon group such as halogen substitution, c is a number from 0.7 to 2.1, and d is a number from 0.001 to 1.0. Yes, but c + d satisfies 0.8 to 3.0.)
The thing represented by is mentioned.

In the average composition formula (2), the substituted monovalent hydrocarbon group represented by R ³ such as unsubstituted or halogen-substituted has usually 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. is there. This monovalent hydrocarbon group does not have an aliphatic unsaturated bond such as an alkenyl group. Specific examples of the unsubstituted or substituted monovalent hydrocarbon group include those exemplified as the silicon atom-bonded organic group other than the silicon atom-bonded alkenyl group in the description of the component (A).

  c is preferably a number of 1.0 to 2.0, d is preferably a number of 0.01 to 1.0, and c + d preferably satisfies 1.0 to 2.5.

Specific examples of the organohydrogenpolysiloxane of this component include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, methylhydrogencyclopolysiloxane, and dimethylsiloxane.・ Methylhydrogensiloxane cyclic copolymer, tris (dimethylhydrogensiloxy) methylsilane, tris (dimethylhydrogensiloxy) phenylsilane, molecular chain both ends trimethylsiloxy group blocked methylhydrogenpolysiloxane, molecular chain both ends trimethylsiloxy group Blocked dimethylsiloxane / methylhydrogensiloxane copolymer, trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane / methylphenylsiloxane copolymer, molecule Both ends dimethylhydrogensiloxy group-blocked dimethylpolysiloxane, Molecular chain both ends dimethylhydrogensiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, Both ends of molecular chain dimethylhydrogensiloxy group-blocked dimethylsiloxane / Methylphenylsiloxane Polymer, both ends of a molecular chain dimethylhydrogensiloxy group-blocked methylphenylpolysiloxane, a siloxane unit represented by the formula: (CH ₃ ) ₂ HSiO _1/2 and a formula: (CH ₃ ) ₃ SiO _1/2 A copolymer comprising a siloxane unit and a siloxane unit represented by the formula: SiO _4/2 , a siloxane unit represented by the formula: (CH ₃ ) ₂ HSiO _1/2 and a formula: SiO _4/2 Copolymers composed of siloxane units, and some of the methyl groups in these exemplified compounds Examples include those in which all are substituted with other alkyl groups or phenyl groups, and mixtures of two or more of these organopolysiloxanes.

Among them, (1) both ends of the molecular chain having no aliphatic unsaturated bond are represented by the formula: R ³ ₃ SiO _1/2 (wherein R ³ is independently as defined above, hereinafter the same). An organohydrogenpolysiloxane that is capped with a siloxane unit that is composed of repeating siloxane units represented by the formula: R ³ HSiO _2/2 and (2) a molecule that does not have an aliphatic unsaturated bond Both ends of the chain are independently blocked with a siloxane unit represented by the formula: R ³ ₃ SiO _1/2 or a siloxane unit represented by the formula: R ³ ₂ HSiO _1/2 , and the main chain is represented by the formula: R ³ ₂ A combination of a siloxane unit represented by SiO _2/2 and a diorganosiloxane / organohydrogensiloxane copolymer consisting of random repeating of a siloxane unit represented by the formula: R ³ HSiO _2/2 preferable. Specifically, (1) molecular chain both ends trimethylsiloxy group-capped methylhydrogenpolysiloxane, and (2) dimethylsiloxane methylhydrogen having both molecular chains capped with trimethylsiloxy group or dimethylhydrogensiloxy group. What used together with the siloxane copolymer is preferable.
Organohydrogenpolysiloxanes may be used alone or in combination of two or more.

  The compounding amount of the organohydrogenpolysiloxane is as follows. The composition of the present invention may contain a component having a silicon atom-bonded alkenyl group other than the component (A) and / or a component having a silicon atom-bonded hydrogen atom other than the organohydrogenpolysiloxane component. Therefore, it is necessary that the total amount of silicon-bonded hydrogen atoms in the entire composition be 0 to 7 mol with respect to a total of 1 mol of silicon-bonded alkenyl groups in the entire composition, preferably Although the amount is 0 to 6 mol, in particular, 0 to 7 mol of silicon atom-bonded hydrogen atoms in the organohydrogenpolysiloxane component with respect to 1 mol of silicon atom-bonded alkenyl group in component (A), In particular, the amount is 0 to 5 mol. This is because when the silicon-bonded hydrogen atom exceeds 7 moles per mole of the silicon-bonded alkenyl group, the adhesion and blocking resistance of the coating film is remarkably inferior. When organohydrogenpolysiloxane is used, the silicon atom-bonded hydrogen atom in the organohydrogenpolysiloxane component is 0.8 mol or more, particularly 1 mol of silicon atom-bonded alkenyl group in component (A). Is preferably used in an amount of 1 mol or more.

-Addition reaction catalyst-
The addition reaction catalyst is a component for promoting / promoting a hydrosilylation reaction between the silicon atom-bonded alkenyl group in the component (A) and the silicon atom-bonded hydrogen atom in the organohydrogenpolysiloxane component. The addition reaction catalyst is not particularly limited, and examples thereof include platinum group metals such as platinum, palladium, and rhodium; chloroplatinic acid, alcohol-modified chloroplatinic acid, chloroplatinic acid and olefins, vinylsiloxane, or acetylene compound. Examples thereof include platinum group metal compounds such as coordination compounds, tetrakis (triphenylphosphine) palladium, chlorotris (triphenylphosphine) rhodium, and preferably platinum compounds.
An addition reaction catalyst may be used individually by 1 type, or may use 2 or more types together.

  The addition amount of the addition reaction catalyst may be an effective amount as a catalyst, but is usually 0 to 0 in terms of the mass of the platinum group metal with respect to the total amount of the component (A) and the organohydrogenpolysiloxane component. 1,000 ppm, preferably 0 to 500 ppm, more preferably 0 to 100 ppm. When this blending amount is appropriate, the addition reaction can be promoted more effectively. In addition, when using an addition reaction catalyst, it is used in an amount of 0.5 ppm or more, particularly 3 ppm or more in terms of the mass of the platinum group metal, based on the total amount of the component (A) and the organohydrogenpolysiloxane component. It is preferable.

-Reaction control agent A reaction control agent will not be specifically limited if it is a compound which has the effect | action which adjusts the reaction rate of hardening reaction with respect to said addition reaction catalyst, A conventionally well-known thing can be used. Specific examples thereof include phosphorus-containing compounds such as triphenylphosphine; compounds containing nitrogen atoms such as tributylamine, tetramethylethylenediamine and benzotriazole; compounds containing sulfur atoms; acetylene-based compounds such as acetylene alcohols; hydro Peroxy compounds; maleic acid derivatives and the like.

  The blending amount of the reaction control agent is preferably adjusted to an optimum amount for each reaction control agent to be used, because the degree of action of adjusting the reaction rate of the curing reaction of the reaction control agent varies depending on its chemical structure. By blending an optimal amount of the reaction control agent, the composition has excellent curability.

-Reinforcing silica It is desirable that reinforcing silica fine powder is further added to the composition of the present invention. The reinforcing silica fine powder is necessary to obtain a silicone rubber having excellent mechanical strength. For this purpose, the specific surface area by the BET method is 100 m ² / g or more (usually 100 ˜500 m ² / g), more preferably 120 to 400 m ² / g. If the specific surface area is less than 100 m ² / g, the reinforcing property may not be sufficient and the rubber strength may be reduced.

Examples of the reinforcing silica fine powder include fumed silica (dry silica), precipitated silica (wet silica), and gel silica (wet silica) having a high specific surface area. Particularly, fumed silica (BET specific surface area is 120 to 350 m). ² / g) and gel method silica (BET specific surface area of 260 to 500 m ² / g) are preferable.

Moreover, you may hydrophobize these surfaces with a surface treating agent. When two or more kinds of surface treatment agents are used in combination, two or more kinds of surface treatment agents may be mixed to perform surface hydrophobization treatment of silica, or two or more kinds may be divided and sequentially used by using a part of each. The surface may be hydrophobized.
These silicas may be used alone or in combination of two or more.

  The amount of the reinforcing silica fine powder added is preferably 0 to 50 parts by mass with respect to 100 parts by mass of the component (A), and the fluidity of the composition is kept good. Since it can make a property and blocking resistance more excellent, More preferably, it is 0-30 mass parts. When this compounding quantity exceeds 50 mass parts, the fluidity | liquidity of a composition may fall and the workability | operativity of hardened | cured material may worsen. In addition, when using a reinforcing silica fine powder, it is preferable to use 5 mass parts or more with respect to 100 mass parts of (A) component, especially 10 mass parts or more.

-Fillers As fillers other than the reinforcing silica described above, inorganic fillers and organic fillers can be mentioned. For example, crystalline silica, inorganic hollow fillers, fumed titanium dioxide, magnesium oxide, zinc oxide, iron oxide, water Inorganic fillers such as aluminum oxide, magnesium carbonate, calcium carbonate, zinc carbonate, layered mica, carbon black, diatomaceous earth, glass fiber; these include organoalkoxysilane compounds, organochlorosilane compounds, organosilazane compounds, low molecular weight siloxane compounds, etc. Inorganic fillers that have been surface-hydrophobized with an organosilicon compound; organosilsesquioxane fine powders, organic resin hollow fillers, silicone rubber powders; and organic fillers such as silicone resin powders.

Other components As other components, for example, a linear diorgano having a silicon-bonded alkenyl group or a silicon-bonded hydrogen atom at one end of the molecular chain and the other end blocked with a trialkylsiloxy group One molecule has one silicon atom-bonded hydrogen atom or one silicon atom-bonded alkenyl group, such as polysiloxane or linear diorganopolysiloxane blocked at both ends with a trialkylsiloxy group. Non-reactive organopolysiloxane having no silicon-bonded hydrogen atom and silicon-bonded alkenyl group; creep hardening inhibitor, plasticizer, thixotropic agent, pigment , dyes, and fungicides, etc., in order to improve the rubber strength of the cured product, for example, the formula: R ^{₃ 3} SiO _1/2 (wherein, R ³ is the And a siloxane unit represented by the formula: SiO _4/2 , containing or not containing an alkenyl group, and a three-dimensional network-structured organopolysiloxane resin. Can do.

  Furthermore, the composition of the present invention can be suitably used without blending an organic solvent, but when coating the composition on various substrates, depending on conditions such as a coating apparatus, toluene, xylene, etc. The composition may be diluted to an arbitrary concentration with an organic solvent.

-Liquid silicone rubber coating composition-
The liquid silicone rubber coating composition of the present invention can be prepared by mixing the components (A) and (B) and optionally optional components. The composition thus obtained is useful as a coating agent for an airbag, particularly as a coating agent for a curtain airbag type airbag.

  The composition of the present invention is preferably liquid at room temperature (25 ° C.) and has a low viscosity. The viscosity (25 degreeC) becomes like this. Preferably it is 1,000-300,000 mPa * s, More preferably, it is 20,000-90,000 mPa * s, Most preferably, it is 30,000-80,000 mPa * s. When this viscosity satisfies such a range, not only the inflated state of the airbag lasts for a sufficient time, but also a good coating layer surface is obtained after coating of the composition.

<Electron beam irradiation method>
In the present invention, as a curing method of the liquid silicone rubber coating composition, by irradiating a total electron beam dose of 30 to 300 Mrad, preferably by irradiating a total electron beam dose of 30 to 300 Mrad in an electron beam molding apparatus. It is characterized by being cured.
As an electron beam curing procedure, electron beam curing was performed with a CB-300 type electron beam molding apparatus (Energy Science, Inc.). The liquid silicone rubber coating composition is coated on a base fabric used for an air bag and passed through an inactivated chamber of the apparatus (<50 ppm oxygen). Thereafter, it can be cured by exposure to electron beam irradiation in a deactivated chamber, giving a total electron beam dose of 30-300 Mrad, especially 50-200 Mrad. Below 30 Mrad, curing is inadequate, and a total electron beam dose greater than 300 Mrad becomes uneconomical.
Further, the electron beam curing is preferably a belt conveyor type rather than a batch type. In the batch type, when the object to be cross-linked is put into the furnace, the oxygen concentration in the chamber temporarily increases, and the surface cross-linking property may be deteriorated.

<Air bag>
The airbag having a rubber coating layer made of a cured product of the composition of the present invention, preferably a curtain airbag, is not particularly limited, and a conventionally known one can be used. Specific examples thereof include synthetic fiber base materials such as nylon 66, nylon 6, polyester fiber, aramid fiber, and polyamide fiber; non-woven fabric base material; air based on fabric such as thermoplastic resin sheet or film base material. Examples include bags, particularly curtain airbags.

A method for coating the air bag with the composition of the present invention is not particularly limited, and a conventional method can be adopted. The amount of the composition applied to the air bag (base fabric) surface to form the rubber coating layer is usually 10 to 150 g / m ² , preferably 15 to 80 g / m ² in the cured state, and more Preferably it is 20-60 g / m < ² >.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely using an Example and a comparative example, these Examples do not restrict | limit this invention at all. “Part” means “part by mass”, and the viscosity is a value measured by a rotational viscometer at 25 ° C. Further, the adhesion improvers (i) and (ii) used in the examples have a structure represented by the following chemical formula.

・接着性向上剤（ｉｉ）

Adhesion improver (i) [epoxy equivalent: 238 g / mol]

-Adhesion improver (ii)

[Example 1]
40 parts of dimethylpolysiloxane blocked with dimethylvinylsiloxy group at both ends of a molecular chain having a viscosity of 1,000 mPa · s, 40 parts of dimethylpolysiloxane blocked with dimethylvinylsiloxy at both ends of a molecular chain having a viscosity of 5,000 mPa · s, An organosiloxane unit containing 5 mol% of vinylmethylsiloxane units and 95 mol% of dimethylsiloxane units, and having a viscosity of 700 mPa · s, a trimethylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane copolymer 20 at both molecular chains. Part, 17 parts of hydrophobic fumed silica having a BET specific surface area of 120 m ² / g surface-hydrophobized with a trimethylsilyl group, 1.5 parts of adhesion improver (i), 0.5 part of adhesion improver (ii) , 0.5 parts of octyl titanate (titanium tetraoctyl oxide), and a BET specific surface area of 20 m is ² / g, and the average particle size 8μm of precipitated silica: by (Tosoh Silica Co., Ltd., trade name NIPSIL LP) uniformly mixing 10 parts, to prepare a composition 1.

The composition 1 was used to coat the base of a curtain-type airbag using a coater so that the composition was uniform without uneven coating. The coat thickness was adjusted so that the thickness of the flat portion of the cloth was about 50 g / m ² after curing. Thereafter, a cured product on a nylon 66 base fabric irradiated with a total electron beam dose of 100 Mrad was prepared, and a curtain airbag having a rubber coating layer was produced. According to the following measuring method, the adhesiveness, the inflation, and the blocking resistance were tested. The obtained results are shown in Table 1.

<Measurement method>
1. Scott stagnation (adhesiveness) test The Scott stagnation test was conducted using a Scott stagnation tester. The curtain airbag having the rubber coating layer was subjected to a stagnation test 500 times at a pressing pressure of 5 kgf, and then the state of destruction of the coating portion was visually confirmed, and the rubber coating layer was not peeled off from the coating surface. It was evaluated as acceptable and the case of peeling was evaluated as unacceptable. The results are shown in Table 1.

2. Inflation test The air bag was inflated instantaneously by blowing air for 3 seconds at an air pressure of 690 kN / m ² for the curtain airbag having the rubber coating layer, and its airtightness was observed with the naked eye. A case where peeling is not recognized in the rubber coating layer is evaluated as “good” and indicated as “A”, and a case where peeling is recognized in the rubber coating layer is evaluated as “bad” and indicated as “B”.

3. Blocking resistance test It was performed as a test for evaluating the stickiness on the surface of the rubber coating layer.
About the curtain airbag which has said rubber coating layer, it cut | disconnected to width 100mm x length 200mm, and made the rubber | gum coating surface contact | adhere so that air may not enter into a glass plate. The glass plate to which this film-forming cloth was in close contact was set up vertically, the elapsed time until the film-forming cloth naturally dropped from the glass plate was measured, and evaluated according to the following evaluation criteria. As described above, when the elapsed time from the vertical standing of the glass plate to the time when the film-forming cloth fell from the glass plate was less than 1 second, it was evaluated as “good” and indicated as “A” for 1 second or longer. If it was less than 3 seconds, it was evaluated as “Slightly Good” and indicated as “B”, and if it was 3 seconds or more and less than 6 seconds, it was evaluated as “Yes” and indicated as “C”, and was 6 seconds or more and less than 10 seconds Is evaluated as “slightly defective” and indicated as “D”, and when it was 10 seconds or longer, it was evaluated as “defective” and indicated as “E”.

[Example 2]
100 parts of dimethylpolysiloxane blocked with a dimethylvinylsiloxy group at both ends of a molecular chain having a viscosity of 1,000 mPa · s, 33 parts of a hydrophobic fumed silica having a BET specific surface area of 170 m ² / g surface-hydrophobized with a trimethylsilyl group, and a viscosity of 45 mPa · s molecular chain both ends trimethylsiloxy group-blocked methylhydrogenpolysiloxane (content of silicon-bonded hydrogen atoms = 1.14% by mass) 2.7 parts, molecular chain both ends and molecules having a viscosity of 12 mPa · s Dimethylsiloxane / methylhydrogensiloxane copolymer having a silicon atom-bonded hydrogen atom at the chain non-terminal (content of silicon atom-bonded hydrogen atom = 0.54 mass%) 8.3 parts, 1-ethynylcyclohexanol 0.06 Part, the complex of chloroplatinic acid and divinyltetramethyldisiloxane in terms of platinum group metal mass ( ) Component and organohydrogenpolysiloxane component, 15 ppm, adhesion improver (i) 1.5 parts, adhesion improver (ii) 0.5 parts, and octyl titanate 0.5 parts Composition 2 was prepared by mixing. In the composition 2, the SiH / SiVi was 3.3 mol.
A curtain air bag was prepared by irradiating the composition 2 with a total electron beam dose of 100 Mrad using an electron beam forming apparatus in the same manner as in Example 1, and tests and measurements of adhesiveness, inflation, and blocking resistance were performed in Example 1. The same was done. The obtained results are shown in Table 1.

[Example 3]
A curtain airbag was prepared by irradiating composition 1 with a total electron beam dose of 200 Mrad using an electron beam forming apparatus, and tests and measurements of adhesion, inflation, and blocking resistance were conducted in the same manner as in Example 1. The obtained results are shown in Table 1.

[Example 4]
A curtain airbag was prepared by irradiating the composition 2 with a total electron beam dose of 200 Mrad using an electron beam forming apparatus, and tests and measurements of adhesiveness, inflation, and blocking resistance were conducted in the same manner as in Example 1. The obtained results are shown in Table 1.

[Comparative Example 1]
A composition 3 in which 1.5 part of the adhesion improver (i), 0.5 part of the adhesion improver (ii), and 0.5 part of octyl titanate is omitted from the composition 1 is 100 Mrad in an electron beam forming apparatus. A curtain airbag irradiated with the total electron beam dose was prepared, and tests and measurements of adhesiveness, inflation, and blocking resistance were conducted in the same manner as in Example 1. The obtained results are shown in Table 1.

[Comparative Example 2]
A cured product was prepared by irradiating composition 2 with a total electron beam dose of 20 Mrad using an electron beam forming apparatus, and tests and measurements of adhesion, inflation, and blocking resistance were performed in the same manner as in Example 1. The obtained results are shown in Table 1.

<Evaluation>
As is clear from Table 1, in Examples 1 to 4 of cured products irradiated with a total electron beam dose of 30 to 300 Mrad in an electron beam forming apparatus that satisfies the requirements of the present invention, the obtained curtain airbag was measured. All of the properties were excellent. On the other hand, in Comparative Example 1 that does not include the component (B) and Comparative Example 2 that does not satisfy the total electron beam dose of 30 to 300 Mrad in the electron beam forming apparatus, the obtained curtain airbag has adhesiveness, blocking resistance, and The result of the inflation test was inferior.

Claims (9)

On at least one surface of the base fabric,
(A) Organopolysiloxane containing at least two alkenyl groups bonded to a silicon atom in one molecule and no other functional group in the molecule: 100 parts by mass
(B) Adhesion improver (except (A)) : A liquid silicone rubber coating composition containing 0.1 to 10 parts by mass is applied and irradiated with a total electron beam dose of 30 to 300 Mrad. Thus, the liquid silicone rubber coating composition is cured by crosslinking with an electron beam. (B) The adhesion improver is
(I) an organosilane having at least two kinds of functional groups, or a linear, cyclic or branched siloxane oligomer having 3 to 100 silicon atoms and having at least two kinds of functional groups,
Alkenyl group bonded to silicon atom, epoxy group bonded to silicon atom via carbon atom, acryloxy group or methacryloxy group bonded to silicon atom via carbon atom, alkoxysilyl group bonded to silicon atom via carbon atom , alkoxy groups bonded to silicon atoms, an ester structure, a urethane structure, ether structure, isocyanate group, and is selected from the group consisting of hydrogen atoms bonded to a silicon atom, an organosilane or at least two having at least two functional groups A linear, cyclic or branched siloxane oligomer having 3 to 100 silicon atoms and having a functional group of:
(Ii) a nitrogen-containing organosilicon compound selected from (alkoxy) silyl-modified products of triallyl isocyanurate and siloxane derivatives thereof,
(Iii) a non-silicon organic compound selected from organic acid allyl esters having at least one alkenyl group and at least one ester group in the molecule;
(Iv) an organic titanium compound,
as well as
(V) Organic zirconium compound
The method for producing a silicone airbag according to claim 1, wherein the silicone air bag is one or more selected from the group consisting of (i) to (v) .   (B) The adhesion improver is an organosilicon compound having an epoxy equivalent of 100 to 5,000 g / mol, a silicon atom-bonded alkenyl group and / or a silicon atom-bonded hydrogen atom and a silicon atom-bonded alkoxy group in each molecule. The method for producing a silicone airbag according to claim 2, wherein the number is one or more selected from organic silicon compounds, organic titanium compounds, organic zirconium compounds, and nitrogen-containing organic silicon compounds. The liquid silicone rubber coating composition further comprises an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms in one molecule and not containing other functional groups in the molecule. The manufacturing method of the silicone airbag of any one of 1-3.   The method for producing a silicone airbag according to claim 4, wherein the liquid silicone rubber coating composition further comprises an addition reaction catalyst.   The method for producing a silicone airbag according to any one of claims 1 to 5, wherein the liquid silicone rubber coating agent composition does not contain an organic solvent.   The method for producing a silicone airbag according to claim 1, wherein the silicone airbag is a curtain airbag.   The method for producing a silicone airbag according to any one of claims 1 to 7, wherein the electron beam is irradiated with an electron beam forming apparatus.   The method to improve the blocking resistance of a silicone airbag which consists of manufacturing a silicone airbag by the method of any one of Claims 1-8.