JP3121755B2 - Film-forming emulsion-type silicone composition for airbag and airbag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of safely adjusting the viscosity corresponding to various coating methods to the environment and the human body without using a harmful organic solvent, has excellent coating properties, and is capable of bonding to a base fabric for an airbag. Film-forming emulsion-type silicone composition for an airbag, which is capable of forming a cured rubber film having good airtightness and airtightness and reduced surface tackiness, and air having a cured film of the film-forming emulsion-type silicone composition formed thereon The present invention relates to an airbag formed by sewing a bag base fabric.

[0002]

BACKGROUND ART In recent years, a so-called airbag device has been widely used as a safety device provided in front of an automobile seat. This airbag device is configured to include a bag-shaped airbag, a sensor that senses an impact given to an automobile, and an inflator that instantaneously sends gas into the airbag by the sensor to inflate the airbag. ing. The airbag is
Normally, it is folded and stored inside the steering wheel etc., but if the car receives a strong impact due to a collision accident etc., the sensor arranged at the center of the dashboard floor and the front floor detects the impact, In the inflator, a gas generating agent containing sodium azide or the like as a main component is reacted to generate nitrogen gas, and the nitrogen gas is fed into the airbag to instantly inflate the airbag. That is, the airbag device senses an impact at the time of occurrence of a car accident and instantaneously inflates the airbag. With the inflated airbag, the impact to the occupant at the time of occurrence of the car accident is effectively reduced. It has a crucial role in protecting the occupant's body. Generally, an airbag of such an airbag device is provided with chloroprene rubber (Japanese Patent Application Laid-Open No. 49-55028) on one side (the inner side of the airbag) of a woven fabric made of a synthetic resin such as a nylon resin. )
The cloth material on which a silicone rubber coating (Japanese Patent Application Laid-Open No. 2-270654) is formed is cut into a predetermined shape, and a plurality of the obtained base fabrics are sewn in a bag shape. In addition, the coating formed on the inner surface of the bag imparts airtightness to the woven fabric, and at the moment the airbag is deployed, the nylon woven fabric is directly exposed to a high-temperature gas that is pressed into the airbag at a stretch. This prevents the nylon resin from melting and deteriorating, and has a function of protecting the occupant from high-temperature gas. Therefore, this coating is required to have some heat resistance. On the other hand, airbags usually need to be folded and stored in a handle or the like, and since it is desired to save space in the storage part, the airbag can be folded as compactly as possible. It is desirable that Therefore, initially, chloroprene rubber was mainly used as the coating. However,
Chloroprene rubber has insufficient heat resistance and durability, and has a drawback of shortening the life of the airbag. In addition, in order to avoid the effects of fire and blast generated when a vehicle or the like collides, it is necessary to impart flame retardancy to the airbag. The chloroprene rubber has insufficient flame retardancy, and a silicone flame retardant has been further applied to the surface to be exposed to the blast.

On the other hand, in the case of an airbag coated with silicone rubber, it is possible to impart a flame retardancy to the coating film itself by applying a known flame retardant to the silicone, and it is necessary to coat the flame retardant. Sex has gone. For this reason, silicone rubber coating agents which are more excellent in heat resistance and weather resistance than chloroprene rubber have been attracting attention. An airbag coated with silicone rubber is usually stored in a handle or the like,
When collided, inflated by blast. At this time, the coating film also instantaneously expands following the elongation of the base fabric,
Silicone rubber coatings also require mechanical strength and elongation. For this purpose, a base polymer having a large degree of polymerization and a high viscosity is used, and further, a reinforcing agent, a flame retardant,
An adhesion aid or the like is blended. However, these silicone compositions are generally high viscosity, it is difficult to apply the required amount 30 to 100 g / m ² by knife coating or the like, Therefore diluted with an organic solvent such as toluene or xylene The viscosity is adjusted so as to be easily coated by knife coating or the like, and after the application, the solvent is evaporated while the solvent is evaporated to be cured. Therefore, in the case of rubber for airbags, it is difficult to apply a coating amount of 30 to 100 g / m ² , which is usually required, by using a coating such as a knife, a roll, and a gravure which is generally used for a rubber coat. It is common practice to dilute these rubbers with an organic solvent to adjust them to an appropriate viscosity before use. However, these organic solvents may not only ignite due to static electricity, but also harm the health of workers due to suction and skin contact, or require a large cost for recovery after the solvent is volatilized. Further, if not collected, there is a problem that it leads to air pollution and the like, and in recent years, the regulation of organic solvents is being enforced in all fields.

In order to obtain a coating composition having a viscosity that allows easy coating with a knife coating or the like without using an organic solvent, there is a method of lowering the degree of polymerization of the base polymer of the coating composition to lower the viscosity. With the composition, the mechanical strength of the cured film formed on the base fabric is not sufficient, and the high temperature blast when the airbag is opened may cause cracks in the coating surface, air may leak, and the bag may not expand sufficiently. . Further, the conventional rubber coating composition has a problem that the cured film surface has high tackiness and the coating surfaces are easily blocked.

[0005] On the other hand, as for a film-forming type emulsion type silicone composition, various silicone aqueous emulsion compositions which form an elastomeric substance after removing water have been proposed. For example, Japanese Patent Publication No. Sho 38-860 discloses a structure composed of polydiorganosiloxane, polyorganohydrogensiloxane, polyalkyl silicate and a tin salt of a fatty acid in which both molecular terminals are blocked with hydroxyl groups.
Japanese Patent Publication No. 57063/1982 discloses a polydiorganosiloxane in which both ends of a molecular chain are blocked with a hydroxyl group, which is composed of a tri- or higher functional silane and a tin salt of a fatty acid.
Japanese Patent Publication No. 226 discloses a composition composed of polydiorganosiloxane, polyorganohydrogensiloxane and a platinum compound in which both molecular chain terminals are blocked with a vinyl group.
JP-A-54-131661 proposes a product obtained by emulsion polymerization of a cyclic organosiloxane and a functional group-bonded organoalkoxysilane. However, elastomeric substances formed from these emulsion compositions are excellent in heat resistance, water repellency, weather resistance, transparency, etc., but are inferior in mechanical strength, and for example, are not suitable for use as a coating agent. It was inappropriate.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention has excellent adhesiveness and airtightness to an airbag base fabric, and has a crosslinking site (containing a silicon-bonded hydroxyl group and a silicon-bonded hydrogen atom) in the same molecule. A polyorganohydrogensiloxane or a polyorganohydrogensiloxane containing a silicon-bonded alkenyl group and a silicon-bonded hydrogen atom, not a blend of two or more siloxanes). By using an emulsion-type silicone composition capable of forming an elastomeric material having excellent mechanical properties, a film-forming emulsion-type silicone composition for an airbag that does not use a harmful organic solvent and an airbag having a cured film thereof formed. The purpose is to provide.

[0007]

The present inventors have conducted intensive studies to achieve the above object, and as a result, by using a film-forming emulsion containing the above-mentioned polysiloxane as a main component, it has been found that it is superior to various airbag base fabrics. It exhibits excellent adhesiveness, airtightness and mechanical properties, can be adjusted to a viscosity suitable for knife, roll gravure coating, etc. without using harmful organic solvents, and forms a surface state along the unevenness of the base fabric By reducing the tackiness on the rubber surface, improving the workability when sewing as an airbag, or finding that there are various advantages such as not causing blocking when the rubber surfaces come into contact with each other, The invention has been completed. That is, the present invention provides (A) an average compositional formula R ⁰ _{a Hb} SiO _{(4-ab) / 2} (I) wherein R ⁰ is a substituted or unsubstituted monovalent monovalent having 1 to 8 carbon atoms. Organic group, a is 1.01 to 2.01, b is 0.01 to 1.01, a + b = 1.
Indicates a number between 80 and 2.20. ) Polyorganohydrogensiloxane 100 whose molecular terminal is blocked with a hydroxyl group
(B) 1 to 20 parts by weight of an emulsifier, (C) 50 to 1000 parts by weight of water, and (D) 0.1 to 5 parts by weight of a curing catalyst. Composition, and (A) average compositional formula R ¹ _a R ² _b H _c SiO _{(4-abc) / 2} ... (II) (wherein, R ¹ is a substituted or unsubstituted group containing no ethylenically unsaturated group) A monovalent hydrocarbon group having 1 to 18 carbon atoms, R ² is a monovalent hydrocarbon group having 1 to 8 carbon atoms including an ethylenically unsaturated group, a is 1.02 to 2.01, b is 0.005 to 0.50, c is 0.00
5 to 0.50, b / c = 1/5 to 10/1, a + b + c = 1.80-
Indicates the number of 2.20. 100 parts by weight of the polyorganohydrogensiloxane represented by the formula (1), 1 to 20 parts by weight of the emulsifier (B),
(C) 50 to 1000 parts by weight of water and (D) 1 × 10 ^-6 to 1 part by weight of a curing catalyst (as a constituent metal), a film-forming emulsion type silicone composition for an airbag, further comprising An airbag formed by sewing an airbag base fabric on which a cured coating of the emulsion type silicone composition is formed.

The emulsion type silicone composition according to the present invention can be produced as follows. That is, (A) 100 parts by weight of the polyorganohydrogensiloxane represented by the average composition formula (I) or (II), (B) emulsifier 1
20 parts by weight and 50 to 1000 parts by weight of (C) water are weighed, respectively, and subjected to, for example, a high-speed rotating homogenizer to prepare an emulsion, and then, per 100 parts by weight of the polyorganohydrogensiloxane in this emulsion, (D) curing Catalyst
0.1 to 5 parts by weight (when (I) is used as a polyorganohydrogensiloxane) or 1 × 10 ^-6 to 1 part by weight (as a constituent metal) (when (II) is used as a polyorganohydrogensiloxane) Can be manufactured. Since the silicone aqueous emulsion composition according to the present invention is composed of a single molecule (not a blend of plural kinds of siloxanes), it has a homogeneous composition and properties. Therefore, since it can be uniformly applied to the airbag base cloth, it is possible to sufficiently and effectively exhibit the required properties, and the elastomer having excellent mechanical strength finally obtained. A cured product is obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the components constituting the aqueous silicone emulsion composition according to the present invention will be described. In the polyorganohydrogensiloxane which is the component (A) of the present invention, in the case where the polyorganohydrogensiloxane represented by the average composition formula (I) has a molecular end blocked by a hydroxyl group, an organic group bonded to a silicon atom R ⁰ is a substituted or unsubstituted monovalent organic group having 1 to 8 carbon atoms,
R ⁰ may or may not contain an ethylenically unsaturated group.
On the other hand, in the case of the polyorganohydrogensiloxane represented by the average composition formula (II), one of the organic groups bonded to the silicon atom, R ¹ is a substituted or unsubstituted carbon atom containing no ethylenically unsaturated group. It is a monovalent hydrocarbon group having 1 to 18 carbon atoms, and the other organic group R ² must be a monovalent hydrocarbon group having 1 to 8 carbon atoms including an ethylenically unsaturated group. . Here, as a substituted or unsubstituted monovalent hydrocarbon group having 1 to 18 carbon atoms not containing an ethylenically unsaturated group, a methyl group, an ethyl group, a propyl group, a hexyl group, an octyl group, a decyl group, Linear or branched alkyl groups such as hexadecyl group and octadecyl group, aryl groups such as phenyl group, naphthyl group and xenyl group, aralkyl groups such as benzyl group, β-phenylethyl group, methylbenzyl group and naphthylmethyl group, and cyclohexyl And cycloalkyl groups such as cyclopentyl group. The substituted organic group is a group in which a hydrogen atom of the unsubstituted organic group is substituted with a halogen atom such as fluorine or chlorine, for example, a 3,3,3-trifluoropropyl group or a 3-chloropropyl group. And the like.
Next, 1 to 8 carbon atoms containing an ethylenically unsaturated group.
Examples of the valent hydrocarbon group include a vinyl group, an allyl group, a homoallyl group, a 5-hexenyl group, and a 7-octenyl group, and a vinyl group and an allyl group are preferable. In addition, as this ethylenically unsaturated group, a general formula,

[0010]

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[0011] The following are mentioned. However, in the above formula, n is an integer of 0 to 10. _{CH 2 = CH-O- (CH} 2) n - as represented by the vinyloxy propyl group, and the like vinyloxyethyl group, vinyloxy propyl group.

[0012]

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In the case of R ³ , R ³ is a hydrogen atom or an alkyl group having 1 to 6 (preferably 1 to 2) carbon atoms, such as a vinylphenyl group, an isopropenylphenyl group,
1- (vinylphenyl) ethyl group, 2- (vinylphenyl) ethyl group, (vinylphenyl) methyl group, 2- (vinylphenoxy) ethyl group, 3- (vinylbenzoyloxy) propyl group, 3- (isopropenylbenzoyl) Examples thereof include an amino) propyl group.

[0014]

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In the case of the above, R ⁴ is a hydrogen atom or a methyl group, R ⁵ is an alkylene group having 1 to 6 carbon atoms, an alkylene group containing -O- or -S- or a divalent group, Or

[0016]

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[0017] In the group represented by, R ⁶ is a monovalent hydrocarbon group or (meth) acryloyl group having 1 to 6 carbon atoms, R ⁷
Is an alkylene group having 1 to 6 carbon atoms. Here, as the group containing an ethylenically unsaturated group, a γ-acryloxypropyl group, a γ-methacryloxypropyl group, an N-methacryloyl-N-methyl-γ-aminopropyl group, an N-acryloyl-N-methyl-γ -Aminopropyl group, N, N
-Bis- (methacryloyl) γ-aminopropyl group, n,
Examples thereof include n-bis- (acryloyl) -γ-aminopropyl group. In the case of CH ₂ CHCH— (CH ₂ ) _n −, n is an integer of 0 to 10, and the above-described vinyl group, aryl group, and the like. Further, as another monovalent substituted hydrocarbon group in the component (A), a carbon functional group composed of a carbon atom and a hydrogen atom, and further at least one atom of nitrogen and oxygen, may be mentioned.
The emulsion composition using the component (A) containing such a carbon functional group has an excellent adhesive property (adhesion or fixation) when applied to a base material of an airbag and is advantageous. Such carbon functional groups include

[0018]

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And the like. In the polyorganohydrogensiloxane constituting the component (A), the ethylenically unsaturated siloxane has a Si-H group content of 0.02 to 10 mol%, preferably 0.05 to 5 mol%, based on the total organic groups. The saturated group is selected to be 0.02 to 10 mol%, preferably 0.05 to 5 mol%, of the total organic group (the ethylenically unsaturated group in the polyorganohydrogensiloxane represented by the average composition formula (I) is Included). The reason is that if it is less than 0.02%, the mechanical strength may be reduced and curing may be poor, and if it exceeds 10%, the cured film may be hard and rubber elasticity may be deteriorated. (A)
The molecular structure of the polyorganohydrogensiloxane as a component is preferably substantially linear, and this term is generally referred to as linear or slightly branched linear.
Further, the silicon atom-bonded hydrogen group and the group containing the ethylenically unsaturated group may be at any position in the molecular chain terminal or in the molecular chain, and when the molecular chain terminal is not a hydrogen group or an ethylenically unsaturated group, And those blocked with a hydroxyl group, an alkoxy group, a trimethylsilyl group, a dimethylphenylsilyl group, a 3,3,3-trifluoropropyldimethylsilyl group or the like. Further, the molecular weight of component (A) is not particularly limited, but in order to obtain a cured film having excellent physical properties, a molecular weight of 3000
Desirably more than about. The polyorganohydrogensiloxane can be produced, for example, by subjecting a cyclic polyorganosiloxane to ring-opening polymerization or by subjecting a hydrolyzable group-containing silane compound to hydrolysis and condensation polymerization.

The emulsifier of the component (B) serves to stably exist the polyorganohydrogensiloxane of the component (A) in water and / or emulsification polycondensation of cyclic polyorganosiloxanes when forming the aqueous silicone emulsion. (A)
Since the Si-H bond in the component is less susceptible to decomposition during polycondensation, a cationic emulsifier having a polycondensation catalytic action,
Among the anionic emulsifiers, the use of an anionic emulsifier is preferred in the present invention. Examples of such anionic emulsifiers include aliphatic substituted benzenesulfonic acid, aliphatic substituted naphthalenesulfonic acid, aliphatic sulfonic acid, and silylalkylsulfonic acid in which the aliphatic substituent has a carbon chain having a carbon atom length of 6 to 18. And organic sulfonic acid-based emulsifiers such as aliphatic-substituted diphenyl ether sulfonic acid. Among them, aliphatic-substituted benzenesulfonic acid is more preferable. However, when the aqueous silicone emulsion is prepared, it is used in the form of these sulfonic acids, but is neutralized later with an alkali, and therefore exists in the form of a sulfonic acid salt in the composition of the present invention. The mixing ratio of the emulsifier of the component (B) is usually 1 to 20 parts by weight based on 100 parts by weight of the polyorganohydrogensiloxane of the component (A). If the amount is less than 1 part by weight, it is difficult to form stable micelles. If the amount is more than 20 parts by weight, the emulsion viscosity increases, and all of them become unstable emulsions. If necessary, a nonionic emulsifier may be used in combination as the component (B). Examples of the nonionic emulsifier include glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene (hereinafter abbreviated as POE) alkyl ether, POE sorbitan fatty acid ester, POE glycerin fatty acid ester, POE alkylphenol ether, and POE polyoxypropylene block copolymer. And the like.

The amount of water of component (C) is as follows.
It is usually in the range of 50 to 1000 parts by weight with respect to 00 parts by weight.
If the component (D) is less than 50 parts by weight or more than 1000 parts by weight, the emulsified state is poor and the emulsion becomes unstable.

The curing catalyst of the component (D) is a dehydrocondensation reaction between a silicon-bonded hydrogen atom and a silicon-bonded hydroxyl group (when (I) is used as the polyorganohydrogensiloxane) or a silicon-bonded hydrogen atom. This is for performing an addition reaction with an ethylenically unsaturated group (when (II) is used as the polyorganohydrogensiloxane). In the former dehydrocondensation reaction, catalysts such as metal organic acid salts such as alkyltin organic acid salts and zinc organic acid salts, organic metal alcoholates such as tetrabutoxytitanium, and amines such as n-butylamine and imidazole are exemplified. . In the present invention, alkyltin organic acid salts are preferable, and dialkyltin dicarboxylates such as dibutyltin dilaurate and dioctyltin dilaurate are particularly suitable. In the latter addition reaction, a catalyst such as cobalt, rhodium, nickel, palladium and a platinum compound can be mentioned, and there is no particular limitation, but a platinum compound is preferable. Examples of such platinum-based compounds include chloroplatinic acid, those obtained by dissolving the same in alcohols and ketones and those obtained by aging the solution, complex compounds of chloroplatinic acid and olefins, chloroplatinic acid and alkenylsiloxane. And complex compounds of chloroplatinic acid and diketone, and those carrying platinum black and platinum. In the case of the former dehydrocondensation reaction, the amount of the curing catalyst (D) is usually 0.1 to 5 parts by weight based on 100 parts by weight of the polyorganohydrogensiloxane (A). If it is less than 0.1 part by weight, the curing speed is low and the strength of the cured product is low. On the other hand, if it exceeds 5 parts by weight, the composition tends to increase in viscosity and gel in a short time, and the workability of coating the airbag base fabric is deteriorated. In the latter addition reaction, the metal constituting the curing catalyst is 1 × 10 ^-6 to 1 part by weight based on 100 parts by weight of the polyorganohydrogensiloxane (A). If the amount is less than 1 × 10 ⁻⁶ parts by weight, the crosslinking reaction does not proceed sufficiently, while if it exceeds 1 part by weight, no further effect can be expected and it is uneconomical.

Next, a method for producing the aqueous silicone emulsion according to the present invention will be described. The silicone aqueous emulsion composition according to the present invention is obtained by emulsifying a polyorganohydrogensiloxane represented by the above average composition formula with an effective amount of an emulsifier in an aqueous medium, or a cyclic polyorganosiloxane in the presence of an emulsifier mixture. The main point is to prepare a silicone emulsion by emulsion-polycondensation of the compounds, and then to add a curing catalyst of the component (D). The polyorganohydrogensiloxane containing an ethylenically unsaturated group (II) (including the case where the ethylenically unsaturated group is contained in (I)) used in the present invention is a linear organopolysiloxane having a corresponding structural unit. ,
A branched or cyclic silicone compound is selected at a predetermined composition ratio and these are emulsified and polycondensed, or a hydrolyzable group-containing silane compound is selected at a predetermined composition ratio and co-hydrolyzed and co-hydrolyzed. It can be produced by condensation polymerization.

(1) The polyorganosiloxane component used in the production of the polyorganohydrogensiloxane includes, for example, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, tetramethyltetraphenylcyclotetrasiloxane Cyclic compounds such as siloxane, tetrabenzyltetramethylcyclotetrasiloxane, and tris (3,3,3-trifluoropropyl) trimethylcyclotrisiloxane are exemplified. Similarly, the (2) ethylenically unsaturated group-containing organosiloxane used in the production of polyorganohydrogensiloxane (II) (including the case where (I) contains an ethylenically unsaturated group) includes 1,3, 5,7-tetravinyltetramethylcyclotetrasiloxane, 1,3,5-trivinyltrimethylcyclotrisiloxane, 1-vinylheptamethylcyclotetrasiloxane, 1,3,5,7-tetraallyltetramethylcyclotetrasiloxane, A cyclic compound containing an ethylenically unsaturated group such as 1,3,5,7-tetra (5-hexenyl) tetramethylcyclotetrasilonyl) tetramethylcyclotetrasiloxane is exemplified. Further, (3) the organohydrogensiloxane used in the production of polyorganohydrogensiloxane includes 1,3,5-trimethylcyclotrisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3- Or 1,5-dihydrogenhexamethylcyclotetrasiloxane, 1,3,5,
7-tetraphenylcyclotetrasiloxane, 1,3,5,7
-An organohydrogensiloxane cyclic compound such as tetrabenzylcyclotetrasiloxane.
In addition, in addition to the cyclic compounds exemplified above, a linear or branched organosiloxane, an ethylenically unsaturated group-containing organosiloxane, and an organohydrogensiloxane may be used. In this case, as the linear or branched organosiloxane, it is preferable to use a polyorganosiloxane having 2 to 10 silicon atoms or a polyorganohydrogensiloxane. Trimethylsilyl group, dimethylvinylsilyl group, methylphenylvinylsilyl group, methyldiphenylsilyl group, 3,3,3
Those blocked with a trifluoropropyldimethylsilyl group or the like are preferred.

In the present invention, in addition to the above-mentioned organohydrogensiloxane component, if necessary, (4) an organic silane compound having 1 to 4 alkoxy groups, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxy Silane, vinyltributoxysilane, vinyltri (methoxyethoxy) silane, γ-
Methacryloxyethyltrimethoxysilane, γ-methacryloxyethyltriethoxysilane, γ-acryloxyethyltrimethoxysilane, γ-acryloxyethyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane Silane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, dimethylvinylmethoxysilane, dimethylvinylethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, tetramethoxysilane, tetraethoxysilane, tetra Propoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyl Limethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, ethyltributoxysilane, propyltrimethoxysilane, propylethoxysilane, propyltripropoxysilane, propyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxy Silane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, diethyldibutoxysilane, methylethyltrimethoxysilane, methylpropyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltrimethoxy Silane, phenyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyl And the like dimethoxysilane, etc. fluoride alkoxysilanes such as fluoroalkyl alkoxysilane may be used in combination.

[0026] The siloxane and silanes described above, as a polyorganohydrogensiloxane, if the average composition formula _{^{(I), R 0 a H}} b SiO (4-ab) / 2 ... (I) ( wherein, R ⁰ is a substituted or unsubstituted monovalent organic group having 1 to 8 carbon atoms), a is 1.01 to 2.01, b is 0.01 to 1.01,
a + b = 1.80~2.20 been mixed to have a satisfies the in the case of similarly average compositional formula _{^{(II), R 1 a R}} 2 b H c SiO (4-abc) / 2 ... (II) ( wherein R ¹ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 18 carbon atoms not containing an ethylenically unsaturated group, and R ² is a monovalent hydrocarbon group having 1 to 8 carbon atoms containing an ethylenically unsaturated group. A is 1.02 to 2.01, b is 0.005 to 0.5
0, c is 0.005 to 0.50, b / c = 1/5 to 10/1, a + b +
Each of the silicone components (1) to (4) needs to be selected as a starting material so as to be blended so as to satisfy c = 1.80 to 2.20 and to exhibit a copolycondensed molecular structure.

The above-mentioned alkoxysilane compound can act as a crosslinking agent effective for reinforcing polyorganohydrogensiloxane. For example, trimethoxysilane, vinyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, The addition and blending amounts of trifunctional crosslinking agents such as ethyltriethoxysilane and (3,3,3-trifluoropropyl) trimethoxysilane and tetrafunctional crosslinking agents such as tetraethoxysilane are represented by the above average composition formula. It is at most 10% by weight, preferably at most 5% by weight, based on the amount of polyorganohydrogensiloxane.

In order to improve the adhesiveness (adhesion or fixation) of the aqueous silicone emulsion composition of the present invention to a substrate of an airbag, the composition comprises at least one atom of carbon and hydrogen, and nitrogen and oxygen. It is also possible to add an organosilicon compound having both a carbon functional group and an alkoxy group. Examples of such organosilicon compounds include 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, N-triethylenediaminepropylmethyldimethoxysilane, 3-glycidoxypropylmethyl Diethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, and the like. 10% by weight or less, preferably 5% by weight, based on the amount of polyorganohydrogensiloxane represented by the above average composition formula
The following may be added and blended.

As described above, the aqueous silicone emulsion composition according to the present invention is obtained by emulsifying the above-mentioned polyorganosiloxane and, if necessary, the above-mentioned alkoxysilane with an effective amount of an emulsifier in an aqueous medium, or A silicone aqueous emulsion composition is prepared by emulsion-polycondensation of a cyclic polyorganosiloxane or the like in the presence of the mixture, and then a curing catalyst of the component (D) is added. This emulsifier mainly serves as a surfactant for emulsifying the polyorganosiloxane component, and also functions as a catalyst for the polycondensation reaction with cyclic polyorganosiloxanes,
Anionic emulsifiers, especially organic sulfonic acid emulsifiers, are preferred. The amount of the emulsifier to be used is generally 1 to 20 parts by weight, preferably about 1 to 10 parts by weight, per 100 parts by weight of the component (A). If necessary, a nonionic emulsifier may be used in combination. In this case, the amount of water is usually 50 to 1000 parts by weight, preferably 100 to 50 parts by weight, per 100 parts by weight of the component (A).
0 parts by weight, and the condensation temperature is usually 5 to 100 ° C.

In preparing the aqueous silicone emulsion composition in the composition according to the present invention, a crosslinking agent may be added as a fourth component in order to improve the strength of the cured film. Examples of the crosslinking agent include trimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, ethyltriethoxysilane, (3,3,
Examples include a trifunctional crosslinking agent such as (3-trifluoropropyl) trimethoxysilane and a tetrafunctional crosslinking agent such as tetraethoxysilane. The amount of the crosslinking agent added is
It is usually at most 10% by weight, preferably at most 5% by weight, based on the emulsion composition. Since the silicone aqueous emulsion according to the present invention obtained as described above is acidic, it must be neutralized with an alkali to maintain long-term stability. As the alkaline substance, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate, triethanolamine and the like are used.
For the silicone aqueous emulsion, if necessary, (D)
The addition of the component curing catalyst and stirring and mixing complete the production of the aqueous silicone emulsion composition of the present invention. When using these curing catalysts, it is desirable to use an emulsifier and water by an ordinary method in advance to prepare an O / W type or W / O type emulsion. Furthermore, the addition and stirring and mixing temperature of the curing catalyst is preferably in the range of 5 to 25 ° C. The aqueous silicone emulsion according to the present invention is stable for about 2 months after production or preparation, but when stored for a long period of time, it is preferable to separately store the curing catalyst as a separate component and mix it immediately before use. .

The aqueous silicone emulsion composition according to the present invention contains various fillers, pigments, curing inhibitors, heat-resistant additives in addition to the components (A), (B), (C) and (D). Agents, adhesion improvers, flame retardants and the like may be added. Examples of the filler include colloidal silica, fumed silica, precipitated silica, calcined silica, fumed titanium oxide, crushed quartz, diatomaceous earth, asbestos, alumina silicate, iron oxide, zinc oxide, calcium carbonate, carbon black, iron, and the like. Are exemplified. Examples of pigments include, for example, titanium white, titanium yellow, and red iron, and curing inhibitors include acetylene compounds, hydrazines, triazoles, phosphines,
Mercaptans are exemplified. Furthermore, examples of the heat resistance imparting agent include cerium hydroxide, cerium oxide, iron oxide, fume titanium dioxide, and the like.As the adhesion improver, an organic group such as an amino group, a mercapto group, an epoxy group, and an alkenyl group. Examples thereof include an organosilicon compound having an alkoxy group and an organosilicon compound represented by the following structural formula.

[0032]

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These organosilicon compounds can be used alone or in combination of two or more. Examples of the flame retardant include aluminum hydroxide, magnesium hydroxide, zinc carbonate and the like.

There is no problem even if a thickener is used or diluted with water in order to make the viscosity easy to coat. Further, the treatment of the substrate of the composition of the present invention is carried out by applying a method such as dip coating, spray coating, brush coating, knife coating, or roll coating to various airbag base fabrics, and drying and removing water. Leave it at room temperature for 10 minutes to several hours, or cure it by slightly heating it according to the base material.

[0035]

According to the film-forming emulsion type silicone composition for an airbag of the present invention, the viscosity of the coating liquid when treated to various airbag base fabrics is lower than that of a conventional silicone rubber coating composition. As a result, workability during coating is improved. In addition, since the water gradually evaporates, even in a complicated shape, a rubber coating is formed along the shape of the surface, and blocking does not occur when the rubber surfaces come into contact with each other. Further, it provides a cured film having better mechanical strength than conventional film-forming emulsions. In addition, since no harmful organic solvent is used, the viscosity at the time of work is excellent, and the viscosity can be adjusted to be suitable for various coatings without impairing the worker's health.

[0036]

The present invention will be described below in detail with reference to Examples and Comparative Examples. In the examples, all “parts” are “parts by weight”.
, And all “%” indicate “% by weight”. Preparation Example 1 In a mixture of 2.0 parts of dodecylbenzenesulfonic acid and 320 parts of distilled water, 100 parts of octamethylcyclotetrasiloxane was added.
And a mixture of 6.0 parts of heptamethylcyclotetrasiloxane were added, and the mixture was preliminarily stirred with a homomixer and then passed twice with a homogenizer at a pressure of 300 kgf / cm ² to emulsify and disperse. This emulsified and dispersed liquid was transferred to a separable flask equipped with a condenser, a nitrogen inlet and a stirrer, heated at 85 ° C. for 5 hours while stirring and mixing, cooled at 5 ° C. for 48 hours, and then adjusted to pH 7 with a 10% aqueous sodium carbonate solution. To complete the condensation. In addition, a part of the polyorganohydrogensiloxane emulsion was put into acetone to obtain polyorganohydrogensiloxane powder (particles). IR and ¹ H of this powder,
As a result of ²⁹ Si-NMR analysis, 1.47 mol% of methyl hydrogen siloxane units were contained in all the siloxane units, and as a result of GPC measurement, the number average molecular weight Mn was 3.24 × 10 ⁵
Met. Next, an O / W emulsion (platinum content: 3% by weight) of chloroplatinic acid-olefin complex was added to 350 parts (solid content: 23.5%) of the silicone fine particle emulsion.
82 parts, 3.5 parts of a thickener HPC (hydroxypropylcellulose grade M; manufactured by Nippon Soda Co., Ltd.) and 7.5 parts of an organosilicon compound represented by the following formula

[0037]

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Was added at 25 ° C. and mixed and stirred to obtain a silicone aqueous emulsion composition.
And

Preparation Example 2 In a mixture of 2.0 parts of dodecylbenzenesulfonic acid and 320 parts of distilled water, 100 parts of octamethylcyclotetrasiloxane was added.
, A mixture of 6.0 parts of heptamethylcyclotetrasiloxane and 5 parts of 3-aminopropylmethyldimethoxysilane, preliminarily stirred with a homomixer, and then passed twice with a homogenizer at a pressure of 300 kgf / cm ² to emulsify and disperse. I let it. The emulsified and dispersed liquid was transferred to a separable flask equipped with a condenser, a nitrogen inlet and a stirrer, and heated at 85 ° C for 5 hours while stirring and mixing.
And then cooled to pH 7 with a 10% aqueous sodium carbonate solution.
To complete the condensation. A part of the silicone emulsion prepared above was put into acetone to obtain polyorganohydrogensiloxane powder (particles). As a result of IR and ¹ H, ²⁹ Si-NMR analysis of this powder, methyl hydrogen siloxane unit
1.42 mol%, 3-aminopropylmethylsiloxy unit 1.
GPC measurement showed that the number average molecular weight was Mn = 2.89 × 10 ⁵ . Next, 350 parts of the silicone fine particle emulsion (solid content 23.5
%), 0.84 part of a 50% aqueous emulsion of dibutyltin dilaurate (prepared with 50 parts of dibutyltin dilaurate, 5 parts of sodium dodecylbenzenesulfonate and 45 parts of distilled water), a thickener HPC (hydroxypropylcellulose grade M; Nippon Soda ( 3.5 parts at 25 ° C. were added at 25 ° C. and mixed and stirred to obtain a silicone aqueous emulsion composition, which was used as Preparation 2.

Preparation Example 3 In a mixture of 2.0 parts of dodecylbenzenesulfonic acid and 320 parts of distilled water, 100 parts of octamethylcyclotetrasiloxane was added.
Parts, 5.8 parts of heptamethylcyclotetrasiloxane and
A mixture of 0.6 parts of 1,3,5,7-tetravinyltetramethylcyclotetrasiloxane was added, and the mixture was preliminarily stirred by a homomixer, and then emulsified and dispersed by passing twice with a homogenizer at a pressure of 300 kgf / cm ² . . This emulsification,
The dispersion is transferred to a separable flask equipped with a condenser, a nitrogen inlet and a stirrer, heated at 85 ° C. for 5 hours while stirring and mixing, cooled at 5 ° C. for 48 hours, and neutralized to pH 7 with a 10% aqueous sodium carbonate solution. And the condensation was terminated. In addition, a part of the polyorganohydrogensiloxane emulsion was put into acetone to obtain polyorganohydrogensiloxane powder (particles). Of this powder
As a result of IR and ¹ H, ²⁹ Si-NMR analysis, 1.42 mol of methyl hydrogen siloxane unit in all siloxane units
% And methyl vinyl siloxane unit 0.48 mol%, respectively. As a result of GPC measurement, the number average molecular weight Mn =
It was 3.24 × 10 ⁵ . Next, an O / W type emulsion of chloroplatinic acid-olefin complex (with a platinum content of 3%) was added to 350 parts (solid content: 23.5%) of the silicone fine particle emulsion.
0.82 parts), 3.5 parts of a thickener HPC (hydroxypropylcellulose grade M; manufactured by Nippon Soda Co., Ltd.) and 7.5 parts of an organosilicon compound represented by the following formula:

[0041]

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Was added at 25 ° C. and mixed and stirred to obtain a silicone aqueous emulsion composition.
And

Preparation Example 4 In a mixture of 2.0 parts of dodecylbenzenesulfonic acid and 320 parts of distilled water, 100 parts of octamethylcyclotetrasiloxane was added.
Parts, heptamethylcyclotetrasiloxane 5.8 parts, 1,3,
A mixture of 0.6 part of 5,7-tetravinyltetramethylcyclotetrasiloxane and 5 parts of 3-glycidoxypropylmethyldimethoxysilane is added, and the mixture is preliminarily stirred with a homomixer and then passed twice with a homogenizer at a pressure of 300 kgf / cm ^2. Thereby, emulsified and dispersed. The emulsified and dispersed liquid was transferred to a separable flask equipped with a condenser, a nitrogen inlet, and a stirrer, and stirred while mixing.
After heating at 5 ° C. for 5 hours and cooling at 5 ° C. for 48 hours, the mixture was neutralized to pH 7 with a 10% aqueous sodium carbonate solution to terminate the condensation.
A part of the silicone emulsion prepared above was put into acetone to obtain polyorganohydrogensiloxane powder (particles). IR and ¹ H, ²⁹ Si-NMR of this powder
As a result of analysis, 1.40 mol% of methyl hydrogen siloxane unit, 0.47 mol% of methyl vinyl siloxane unit and 1.97 mol% of 3-glycidoxypropylmethylsiloxy unit were contained in all siloxane units, respectively.
As a result of GPC measurement, the number average molecular weight was Mn = 2.89 × 10 ⁵ . Next, the silicone fine particle emulsion 350
0.82 parts of O / W emulsion (platinum content 3% by weight) of chloroplatinic acid-olefin complex per part (solid content 23.5%)
3.5 parts of a thickener HPC (hydroxypropylcellulose grade M; manufactured by Nippon Soda Co., Ltd.) was added at 25 ° C. and mixed and stirred to obtain a silicone aqueous emulsion composition.

Preparation Example 5 Octamethylcyclotetrasiloxane 100 was mixed in a mixture of 2.0 parts of dodecylbenzenesulfonic acid and 320 parts of distilled water.
The mixture was preliminarily stirred with a homomixer, and then passed twice with a homogenizer at a pressure of 300 kgf / cm ² to emulsify and disperse. The emulsified and dispersed liquid was transferred to a separable flask equipped with a condenser, a nitrogen inlet and a stirrer, and heated at 85 ° C for 5 hours while stirring and mixing.
And then cooled to pH 7 with a 10% aqueous sodium carbonate solution.
To complete the condensation, and used as the main ingredient. This one is
As a result of GPC measurement, the number average molecular weight was Mn = 2.93 × 10 ⁵ . On the other hand, a mixed solution of 2.0 parts of dodecylbenzenesulfonic acid and 320 parts of distilled water has a viscosity of 25 cSt represented by the following formula.
100 parts of polymethylhydrogensiloxane

[0045]

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After the mixture was preliminarily stirred with a homomixer, the mixture was passed twice with a homogenizer at a pressure of 300 kgf / cm ² to emulsify and disperse to obtain a curing agent. next,
To 100 parts of the base material, 5 parts of the curing agent, 0.1 part of a 50% aqueous emulsion of dibutyltin dilaurate (prepared with 50 parts of dibutyltin dilaurate, 5 parts of sodium dodecylbenzenesulfonate, and 45 parts of distilled water), 3-glycidoxypropyltriethyl Methoxysilane 3.0 parts and thickener HPC
(Hydroxypropylcellulose grade M; Nippon Soda Co., Ltd.) (4 parts) was added at 25 ° C., and the mixture was stirred with stirring to obtain a silicone aqueous emulsion composition.

Preparation Example 6 100 parts of α, ω-divinylpolymethylsiloxane base polymer having a viscosity of 10,000 cP was mixed with 15 parts of fumed silica so as to be uniform, and then a solution of chloroplatinic acid in isopropanol was used as a platinum amount. An amount of 20 ppm based on the polymer was uniformly dispersed to obtain a main ingredient. On the other hand, an α, ω-divinylpolymethylsiloxane base polymer having a viscosity of 10,000 cP
Mix 100 parts with 15 parts of fumed silica so as to make uniform, and then add 5.0 parts of polymethyl hydrogen siloxane having a viscosity of 25 cSt represented by the following formula.

[0048]

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And 0.2 parts of a silicon compound having an acetylenically unsaturated group represented by the following formula:

[0050]

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Was uniformly dispersed to obtain a curing agent.

The base resin and the curing agent are added in 50 parts each and 3 parts of an organosilicon compound represented by the following formula:

[0053]

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Was mixed and stirred to obtain a rubber component 6.

Examples 1-4 and Comparative Examples 1-4 Preparations 1-5 and rubber component 6 obtained in Preparations 1-6
Then, various diluents shown in Table 1 were added in amounts shown in Table 1 to obtain a coating composition. 6,6
- amount of rubber to nylon cloth (420D) was coated so as to become a 60~80g / m ^2. Next, the cloth was treated in an oven as follows to obtain a cloth having a cured silicone rubber film. 90 ° C × 5min → 170 ° C × 2min Visual observation of the surface condition of the rubber coating film of the obtained film-forming cloth, evaluation based on the following criteria, and the coefficient of kinetic friction (rubber-rubber-SUS) between the surfaces under the following conditions It was measured.・ Evaluation criteria for coating film surface condition Film thickness ◎; uniform ○; almost uniform △; slight unevenness ×; non-uniform ・ Surface dynamic friction coefficient measurement conditions 150g, speed 100mm / min, temperature 25 ℃, humidity 60% R
H. Paintability When coated on a 6,6-nylon cloth, the ease of application and spread of the rubber coating composition on the cloth was observed and evaluated according to the following four grades. ◎: Easy to spread and spread smoothly ○: Easy to apply △; Slightly difficult to apply ×: Difficult to apply ・ Permeability As in the case of evaluation of wettability, the coating composition was treated with 6,6-
The ease with which the coating composition soaked into the cloth when coated on a nylon cloth was observed and evaluated according to the following four grades. ◎: Good penetration, the entire surface becomes uniform from the surface of the cloth to the inside. ○: Somewhat difficult to penetrate, but uniform from the surface of the cloth to the inside. △: A large amount remains on the surface of the cloth and penetrates sufficiently into the inside. No ×: Only the surface of the cloth does not penetrate into the inside. ・ Adhesiveness and mechanical strength 6,6 －Adhesiveness and mechanical strength of rubber film coated on nylon cloth to nylon cloth (coated nylon cloth Was strongly squeezed with a finger, and those having poor adhesion or poor mechanical strength were peeled off and dropped off from the rubber film on the coating surface), and evaluated by the following three steps. ◎: No rubber film is detached from the coated surface, and excellent adhesion and mechanical strength are exhibited. △: Rubber film is slightly detached and peeled from the coated surface. ×: Rubber film is detached from the coated surface.

[0056]

[Table 1]

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-8-85405 (JP, A) JP-A-7-300774 (JP, A) JP-A-5-202338 (JP, A) JP-A-5-202338 98580 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 183/05 B60R 21/16 C09D 1/00 CA (STN) CAOLD (STN) REGISTRY (STN) WPIDS (STN)

Claims (3)

(57) [Claims] (A) Average compositional formula R ⁰ _{a Hb} SiO _{(4-ab) / 2} (I) wherein R ⁰ is a substituted or unsubstituted monovalent organic compound having 1 to 8 carbon atoms. Group, a is 1.01 to 2.01, b is 0.01 to 1.01, a + b = 1.
Indicates a number between 80 and 2.20. ) Polyorganohydrogensiloxane 100 whose molecular terminal is blocked with a hydroxyl group
1 part by weight, (B) 1 to 20 parts by weight of an emulsifier, (C) 50 to 1000 parts by weight of water, and (D) 0.1 to 5 parts by weight of a curing catalyst. Composition. (A) an average compositional formula R ¹ _a R ² _b H _c SiO _{(4-abc) / 2} ... (II) (wherein R ¹ is substituted or unsubstituted without an ethylenically unsaturated group) A monovalent hydrocarbon group having 1 to 18 carbon atoms, R ² is a monovalent hydrocarbon group having 1 to 8 carbon atoms containing an ethylenically unsaturated group, a is 1.02 to 2.01, b is 0.005 to 0.50 , C is 0.00
5 to 0.50, b / c = 1/5 to 10/1, a + b + c = 1.80-
Indicates the number of 2.20. 100 parts by weight of the polyorganohydrogensiloxane represented by the formula (1), (B) 1 to 20 parts by weight of an emulsifier, (C) 50 to 1000 parts by weight of water, and (D) a curing catalyst (as a constituent metal) 1 × 10 ^−6. To 1 part by weight of a film-forming emulsion-type silicone composition for an airbag. 3. An airbag obtained by sewing an airbag base fabric having a cured coating of the emulsion-type silicone composition according to claim 1 or 2.