JP2001288413A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition comprising a silicone emulsion capable of forming a thin cured film of uniform thickness and to provide an air bag using the same excellent in heat resistance to a high temperature gas generated from the inside of an inflator when the air bag functions, mechanical characteristics to cope with violent movement when it extends and airtightness for a high pressure gas when it is bent and expand, easily processable, produced at high efficiency, excellent in flame retardant characteristics and lightweight. SOLUTION: The coating composition comprises a silicone emulsion having an average particle size ranging from 50 nm to 800 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition containing a silicone emulsion solution as a main component, and more particularly, to a thin and uniform cured film by controlling the average particle size of the emulsion. The present invention relates to a coating composition of a silicone emulsion solution capable of forming a silicone emulsion solution and an airbag or a seat belt using the cured film.

[0002]

2. Description of the Related Art An air bag device is widely used as a safety device mounted on a seat of an automobile or the like. In the past, airbags incorporated in this airbag device were generally made of nylon cloth coated with chloroprene, but the heat resistance and weather resistance of chloroprene rubber were insufficient, so There was a problem that the life of the airbag was short. In addition, in order to make it less susceptible to the effects of fires and blasts that occur in the event of a collision with an automobile, etc., it is essential for the airbag to have flame retardancy.However, conventional airbags made of chloroprene rubber-coated cloth Since the chloroprene rubber has insufficient flame retardancy at the back, it was necessary to further coat a silicone flame retardant on the area where the blast blasts.

On the other hand, in an air bag coated with silicone rubber, good flame retardancy can be obtained by blending a flame retardant with the silicone rubber. Therefore, like a chloroprene rubber, a flame retardant is further added thereon. There is an advantage that there is no need to coat. Incidentally, an example using this silicone rubber coating agent for an air bag is disclosed in, for example, JP-A-63-78744.

As is well known, an air bag coated with silicon rubber is normally folded into a handle of an automobile or the like, and is expanded by a blast at the time of a collision.
At that time, apply the silicone rubber coating composition,
The cured film formed by curing must also be instantaneously stretched following the elongation of the base fabric. For this reason, mechanical strength is required not only for the base fabric but also for the cured film of the coating composition, and in order to satisfy the requirement, it is necessary to use a relatively high molecular weight silicone rubber as the base polymer of the silicone rubber coating composition. General. Further, the silicone rubber coating composition contains a curing agent, a flame retardant, an adhesion aid, a reinforcing agent and the like which are usually used for silicone rubber.

[0005] A coating composition containing such a high molecular weight base polymer has a high viscosity, so that when it is coated with a knife coater, offset coater, gravure coater, or the like, the coating composition has a thickness suitable for an air bag. It becomes difficult to coat to a thickness of 40 μm to 100 μm. Therefore, in practice, a method of diluting the coating composition with an organic solvent, adjusting the coating concentration to an optimum value, and then coating the base fabric is adopted. However, the organic solvent used there is a danger of ignition due to static electricity, etc. In addition, if the organic solvent is taken into the human body by suction and skin contact, it will harm the health of workers, so sufficient exhaust equipment for safety is required. I have.

Further, when a cured film of the coating composition is formed on the base fabric, it is necessary to volatilize the organic solvent of the coating composition. And there is also a problem that the cost of recovery is high.
Therefore, in order to solve these problems of the organic solvent, a water-soluble emulsion that is easy to handle has attracted attention as a coating composition that does not use an organic solvent.

As an example of this emulsion coating, Japanese Patent Application Laid-Open No. Hei 5-202338 discloses a method in which a cured film having a thickness of 40 to 100 μm is formed on a fiber base cloth made of plain woven synthetic fiber yarn such as nylon of about 420 denier. The coating agent obtained is described as having characteristics that the coating agent has excellent adhesion to a base fabric and has no surface tackiness.

However, even with this technique, it has not been possible to sufficiently meet the recent strict requirements for airbags. That is, it has heat resistance to high-temperature gas generated from the inside of the inflator when the air bag is operated, and has excellent mechanical properties against intense movement during expansion and airtightness against high-pressure gas during expansion.
This is because there is a strong demand for lightweight airbags that are easy to process, have high production efficiency, have good flame retardancy, and are lightweight.

However, in order to achieve weight reduction,
If a silicone cured film is formed thinner in a conventional manner on a lightweight base fabric using thin yarn, the heat resistance to the high-temperature gas generated from the inside of the inflator during the operation of the air bag is reduced, and the violent movement during expansion Therefore, there is a problem that cracks are generated on the coating surface and a high-temperature gas is ejected, and the ability to maintain gas tightness is remarkably reduced.

Therefore, in order to overcome those problems,
A technique has been proposed in which a flame retardant is blended with a silicone emulsion to improve the flame retardant properties. However, the trouble is that when the thickness of the cured film on the airbag base fabric is reduced to meet the demand for further weight reduction, the amount of flame retardant added together with the amount of silicone per unit area of the base fabric decreases. As a result, there is a problem that a decrease in flame retardancy cannot be avoided. In particular, the thickness of the cured film is 40 μm
If it is less than the above, a predetermined flame retardancy standard value (for example, US Federal Motor Vehicle Safety Standard: FMVSS No. 302) cannot be satisfied, so that it cannot be practically used as an airbag from the viewpoint of safety.

Conventionally, a thick sheet has to be used. However, a sheet having a thick silicone cured film is difficult to cut and sew, and the productivity is extremely low. . In particular, in recent years, not only a simple bag-shaped shape as in the past but also an airbag or an airbag side curtain having a complicated shape has been demanded, which means that processing is difficult. This is a serious obstacle for the trader.

[0012]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to solve the problem of the conventional silicone emulsion which becomes particularly noticeable when used for an air bag as described above. Provided is a coating composition of a silicone emulsion solution capable of forming a cured film having a uniform thickness, and when a sheet having a cured film of the coating composition formed on a base fabric is used as an airbag, the inside of the inflator is activated during operation. Excellent heat resistance against high-temperature gas generated from the material and mechanical properties against intense movement during expansion, as well as excellent airtightness against high-pressure gas during expansion, easy processing, high production efficiency, and extremely excellent flame retardancy It is another object of the present invention to provide a coating composition which can obtain an excellent effect.

[0013]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, by controlling the particle size of the emulsion in the silicone emulsion solution to a certain range, the coating composition of the silicone composition was obtained. The present inventors have found that the cured film can be formed in a thin and uniform thickness according to the fine irregularities on the surface of the base fabric, and that the characteristics thereof can be remarkably improved.

That is, the present invention provides (1) a coating composition containing a silicone emulsion solution having an average particle size of the emulsion in the range of 50 nm to 800 nm.

(2) The coating composition according to the above (1), comprising a flame retardant emulsified,
(3) 100 parts by weight of silicone as a flame retardant
(2) a cured film obtained by curing the coating composition according to any one of (1) to (3) above using carbon black in an amount of 0.1 to 25 parts by weight to a thickness of 40 μm or less; (5) The sheet as described in (4) above, wherein the support is a base cloth made of yarn of 420 denier or less, (6) an airbag using the sheet as described in (5) above, and (7) the above (5). A seat belt using the described seat is also provided at the same time.

Hereinafter, the present invention will be described in detail. In order to form a thin and uniform cured film using a silicone emulsion solution, the thickness and number of yarns of the base fabric, which affect the coating state from coating to drying and curing, must be controlled. Depth of irregularities on cloth surface,
It is necessary to make the residual oil content, the permeability of the silicone composition into the base fabric, the viscosity of the silicone composition, the emulsion particle diameter, and the like appropriate.

Incidentally, instead of using an emulsion type silicone composition as in the present invention as a silicone composition, a solventless polymer base polymer is directly coated or a solvent polymer base polymer is diluted with a solvent. In the case of coating by any method, it is known that the viscosity of the polymer base polymer has a very large effect on the state of formation of the cured film because the base material is directly coated with the chain or cyclic polymer base polymer. Have been.

However, when coating an emulsion type polymer base polymer as in the present invention,
Unlike the non-solvent type and the solvent type described above because the polymer base polymer is emulsified, the factors that determine the state in which the emulsion particles are present on the base fabric are the size of the emulsion particles, That is, the present inventors have found that the particle diameter is an emulsion particle diameter.

The inventor of the present invention has conducted intensive studies on the optimum particle size of the emulsion for forming a thin and uniform cured film in accordance with the fine irregularities of the base cloth. Particle size of 50 nm to 80
It has been found that the thickness needs to be in the range of 0 nm, preferably in the range of 100 nm to 700 nm, and more preferably in the range of 150 nm to 500 nm.

When the average particle size of the emulsion is smaller than the lower limit of the present invention, even if the fabric is a densely folded woven fabric such as a nylon fiber for an air bag, the coating composition passes through between the yarns of the woven fabric. I will miss it. Then, when strike-through occurs, heat transfer to the inside of the base fabric during drying is delayed, so that the silicone curing time becomes longer than usual, and as a result, production efficiency is extremely reduced.

In addition, when the film is taken up, the base fabric causes blocking, and the coating composition that has slipped through during the operation adheres to the back surface of the base fabric or equipment, thereby greatly reducing workability. Kimono causes serious problems such as soiling of the coating surface and impairing the appearance of the product.

Further, since the hardened film becomes thinner in the part where the strike-through occurs, the part is broken when the air bag is activated, and a high-temperature gas is spouted out or good flame-retardant properties cannot be obtained, which is very dangerous. . Therefore, it is extremely important that the average particle size is not less than the lower limit of the present invention.

On the other hand, when the average particle size of the emulsion is larger than the upper limit of the present invention, it is difficult to uniformly disperse the emulsion on the surface of the base fabric, or various compounds having a small particle size, such as a curing agent, a flame retardant, an adhesion promoter, etc. It has been found that uniform mixing with an agent, a reinforcing agent, or the like becomes difficult, causing problems such as a significant decrease in adhesion and a failure to obtain good flame retardancy.

Even more surprisingly, when coating with a knife coater or a spray, the emulsion particles having a large particle diameter are susceptible to a mechanical shearing force, and the emulsion particles are liable to be broken. It has also been found that gel-like stains originating from them adhere to the coating equipment, thereby hindering the coating or causing such a problem that the stains adhere to the base fabric surface. Therefore, it is also very important to keep the average particle size of the emulsion below the upper limit of the present invention.

The silicone curing system used in the present invention may be a curing system utilizing a dehydration condensation reaction between a hydrogen atom bonded to a Si atom and a hydroxyl group bonded to a Si atom, or a hydrogenation system bonded to a Si atom. In addition to a curing system that uses an addition reaction between atoms and ethylenically unsaturated groups bonded to Si atoms, it has the ability to remove moisture during the drying process and simultaneously form a cured silicone film on a support by curing. Any type of silicone may be used, but it is preferable to use an addition-reaction type silicone which is superior in terms of reaction rate to the dehydration condensation type.

The silicone used in the present invention is emulsified with water in the presence of an emulsifier under water under suitable emulsifying conditions so as to obtain an emulsion having an emulsion particle size within the range of the present invention, and used as a silicone emulsion solution.

The silicone emulsion solution obtained by the above method is preferably stored in the form of at least two different components before use so that curing in the solution does not proceed. That is, one of the components contains a siloxane having an unsaturated aliphatic group, and the other component contains a siloxane having a Si-bonded hydrogen atom. It is preferred to incorporate one or both of the components.

The base fabric used as one of the supports used in the present invention is hemp, cotton, glass, wool, silk, natural fiber and artificial fiber (for example, polyamide, polyester, acrylic, aramid, carbon, polyethylene, polypropylene) Fabrics, fleeces, knits, sediments, knits, films, etc. using yarns or fibers such as polystyrene, polyurethane, silk, viscose, cellulose, etc.).

Among these, nylon 6 and nylon 6 are used as a base fabric for an air bag or a seat belt.
6, polyamide fiber fabrics such as nylon 46, aramid fiber fabrics, polyester fiber fabrics represented by polyalkylene terephthalate, polyetherimide fiber fabrics, sulfone fiber fabrics, carbon fiber fabrics, and the like.

The above-mentioned synthetic fiber woven fabric particularly preferably used is a plain woven woven fabric using a yarn of 420 denier or less, and from the viewpoint of easy processability and light weight, more preferably 350 denier or less. A plain fabric using yarn, particularly preferably a plain fabric using yarn of 210 denier or less.

The coating of the base fabric can be carried out immediately during the washing process of the base fabric or immediately after the washing process. Curing after coating can be performed in one processing step simultaneously with the drying step and the shrinking step. Especially in the case of artificial fiber fabrics that have to be washed and dried, the coating composition of the present invention can be directly coated on the still damp fabric after the washing process, and the curing is performed simultaneously with the drying process. Can do it. On the other hand, in the case of a fabric of an artificial fiber that does not need to be washed, the coating composition of the present invention can be directly coated on the fabric as needed.

For coating the coating composition of the present invention, a commonly used coating method can be used. For example, dipping and padding, brush coating, flow coating, spraying, roller coating, textile printing, knife coating, Meyer bar, air brush, slop padding, roll coating and the like are exemplified. In the case of a base cloth using a yarn of 210 denier or less as the base cloth, coating with a kiss roll coater which is hardly affected by expansion and contraction of the base cloth during coating and has good workability is preferable.

Drying and curing after application of the coating is usually carried out in a heating device which is heated by hot air, infrared, gas burners, heat exchangers or other energy sources. A device having a drying capacity capable of achieving the desired drying and curing, such as a heated roll calender, a heatable laminating press, a heatable step press or a high temperature contact roll,
A floating dryer, a microwave dryer, and the like can also be used.

In performing drying and curing, it is preferable to provide a heating device with a plurality of temperature zones having different temperatures in order to avoid the formation of bubbles in the cured film. 150 ° C, preferably 80-1
Predrying is performed at a temperature of 30 ° C, more preferably 90 to 120 ° C, and curing is performed at a temperature of up to 300 ° C in the subsequent second temperature zone. However, most base fabrics have heat resistance limitations in processing. Therefore, it is actually preferable to cure at a temperature in the range of 120 to 190 ° C.

The residence time required for curing varies depending on the weight of the coating, the thermal conductivity of the base fabric and the heat transfer to the coated base fabric, and is preferably about 0.5 to 30 minutes. In addition, about drying and hardening, it can also be performed by leaving at room temperature for 10 minutes to several tens hours.

The solid components other than silicone, which are optionally added to the coating composition of the present invention, include various additives known as additives for emulsions or silicone rubbers, for example, fillers, pigments, curing inhibitors, Heat imparting agents, adhesion improvers, flame retardants, preservatives, thickeners, stabilizers and the like can be used.

In particular, in the case of using a base cloth made of yarn of 350 denier or less for the purpose of weight reduction which is one of the objects of the present invention, it is necessary to add a flame retardant to the silicone rubber composition of the present invention. . As the flame retardant, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, zinc carbonate, silica, carbon black, a halogen compound, a phosphorus compound and the like can be used. Among them, carbon black is particularly preferable.

The addition amount of the flame retardant is 0.1 to 200 parts by weight, preferably 1 to 100 parts by weight, and most preferably 2 to 50 parts by weight based on 100 parts by weight of the silicone. When using carbon black, carbon black can be directly blended into the silicone emulsion solution,
Those prepared by emulsifying in water in the presence of an emulsifier in advance may be blended. The amount of carbon black to be added is 0.1 to 2 with respect to 100 parts by weight of silicone.
The range is 5 parts by weight, preferably 1 to 20 parts by weight. If the added amount of carbon black exceeds 25 parts by weight with respect to 100 parts by weight of silicone, the flame retardancy will be extremely reduced, and if the coating surface is rubbed with a finger or the like, carbon black will adhere to the fingertips and cause stains Because
The addition amount of carbon black is 25 parts by weight or less based on 100 parts by weight of silicone.

As the filler, colloidal silica, fumed silica, precipitated silica, calcined silica, fumed titanium oxide, crushed quartz, diatomaceous earth, asbestos, alumina silicic acid, iron oxide, zinc oxide, calcium carbonate, carbon black, Metal oxides such as iron, rare earth oxides, cerium silanolate, aluminum oxide, and aluminum hydroxide can be used.

As the pigment, titanium white, titanium yellow, red iron, carbon black and the like are used. As the curing inhibitor, acetylene compounds, hydrazines,
Triazoles, phosphines, and mercaptans are used.

Further, as the heat resistance imparting agent, cerium hydroxide, cerium oxide, iron oxide, fume titanium dioxide and the like are used. As the adhesion improving agent, a usual silane coupling agent such as an amino group, a mercapto group, An organic silicon compound having both an organic group such as an epoxy group and an alkenyl group and an alkoxy group is used.

[0042] Thickeners can be added or diluted with water or an organic solvent so that appropriate coating can be performed in various coating apparatuses. As the thickener, carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, the above-mentioned flame retardants and the like are used. As the preservative, formalin or a chemical substance having a preservative effect extracted from animals and plants is used. The above various additives may be used alone or in combination of two or more.

The above solid components may be directly blended with the emulsion solution, or may be blended with those previously emulsified in water in the presence of an emulsifier. The blending may be carried out at any stage of preparing the emulsion solution. May be. When emulsification is adopted, it is preferable that the particle size is approximately the same as that of the silicone emulsion solution in order to improve the dispersibility with the silicone emulsion solution.
The average particle diameter of the solution obtained by emulsifying the solid component is set to a range of 800 nm or less, preferably 700 nm, more preferably 500 nm.

The sheet having the cured film of the coating composition of the present invention formed on a support may be an airbag, an airbag side curtain and a seat belt, as well as sportswear and sports equipment such as a sail, a boat cover or Materials for rucksacks and tents and their protective coatings, seat covers, conveyor belts, compensators, collapsible containers, raincoats, limbs, tents, tarpaulins, flags, wallpapers, seal labels,
It is used in many applications such as adhesive tapes, interior panels such as passenger cars, and non-slip sheets for furniture and OA equipment.

[0045]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples, “parts” indicates “parts by weight”, and “%” indicates “% by weight”.

[0046]

Examples 1 to 3 and Comparative Examples 1 and 2 700 g of dimethylpolysiloxane having a viscosity of 1000 mPa · s and having vinyldimethylsiloxy units as terminal units,
700 g of methyl hydrogen polysiloxane having a terminal unit of trimethylsiloxy unit having a viscosity of 60 mPa · s
And 15 g of a platinum-divinyltetramethyldisiloxane complex containing 1% by weight of platinum and 1.5 g of ethynylcyclohexanol are emulsified with water in the presence of 190 g of a nonionic emulsifier, to give about 3500 g of an aqueous emulsion. Manufactured. The emulsification is performed at room temperature and atmospheric pressure using a homomixer. At this time, by adjusting the operating conditions of the homomixer, the shear force applied to the silicone particles is changed, and five types of particles having different particle sizes shown in Table 1 are obtained. A silicone emulsion solution was prepared. Note that a submicron particle analyzer manufactured by NICOMP was used to measure the particle size of each sample.

Next, a water-soluble carbon black (Derussol VU25 / made by Degussa Huls) was added to 67 parts of each of the obtained silicone emulsion solutions as a flame retardant.
L, 25 parts of carbon black), 10 parts of a silane coupling agent as an adhesion promoter, and 1 part of carboxymethylcellulose sodium as a thickener, diluted with 100 parts of water and finally solidified. About 18%
Each coating composition shown in Table 1 was prepared.

[0048]

[Table 1]

A predetermined base fabric was coated with each of the above coating compositions. As the coating base fabric, a commercially available plain woven nylon base fabric of 140 denier yarn whose surface was not washed was used. Coating was performed using a knife coater, and drying of the base fabric after coating was performed in three stages in a temperature range of 120 ° C to 170 ° C.

Although the base fabric used in this example was very thin, coating was performed with the above knife coater while paying sufficient attention to the expansion and contraction of the base fabric. As a result, in all the comparative examples and examples, about 10 μm was used. , A thin cured film was formed. However, when the cured state was observed with the naked eye, in Comparative Example 1, it was confirmed that the coating composition penetrated to the back of the base fabric and was not cured. In addition, when the coating surface was rubbed with a finger, the cured product fell off, and the uncured silicone migrated to the fingertips, and the coating surface was stained by the uncured silicone.

On the other hand, in Comparative Example 2, there was no strike-through or uncured of the coating composition, but it was confirmed that the coating surface was soiled and the cured product fell off. In particular, the cured product fell off only by gently rubbing the coating surface with a finger. further,
A gel-like mass had adhered to the blade edge of the knife coater. This gel-like mass was not observed at the start of coating, but gradually adhered and grew on the edge of the knife coater as the coating continued, and was eventually crushed by the knife coater and rubbed against the coating surface. Has become dirty.

On the other hand, in Examples 1 to 3, there was no strike-through and uncured of the coating composition as in the comparative example. In addition, even when coating was continuously performed, no gel-like lump was observed at the edge of the knife coater. There is no dirt on the coating surface, thin and
A cured film having a uniform thickness was formed, and the cured product did not fall off.

The adhesion of the cured film was confirmed by a kneading test. That is, each base cloth after curing is 10 cm long and 5 cm wide.
Two pieces of the cut sample were prepared, and the surfaces on which the cured film was formed were adhered to each other. The surfaces were mechanically rubbed 1000 times in a fixed direction at a constant speed, and then the surface condition was visually observed. As a result, in Examples 1 to 3, the reciprocation was 100
No abnormalities were found in the cured film even after rubbing 0 times or more, but 500 times reciprocation in Comparative Example 1 and 2 reciprocations in Comparative Example 2.
Pinholes and peeling were observed in the cured film at less than 00 times.

Next, the flame retardant properties were evaluated according to the Federal Motor Vehicle Safety Standard: FMVSS No. 302. As a result, in Comparative Examples 1 and 2, combustion was rapid, and in Comparative Examples 1 and 2, combustion was performed at a speed of 100 mm or more per minute. In Comparative Example 1 and Comparative Example 2, the flame at the time of combustion was larger than that of the Example, and more smoke was generated. The speed at which the flame propagated through the base fabric accelerated after the base fabric was ignited, and the burning base fabric dropped while melting. On the other hand, Examples 1 to 3 all exhibited good flame retardant properties, and exhibited a combustion rate of less than 10 mm per minute and self-extinguished. The flame at the time of combustion was smaller than that of the comparative example, the generation of smoke was small, and the burning base cloth was not dropped while melting. The residue after combustion formed an off-white film.

Next, an airbag inflation test was performed. That is, the temperature 160 ~
Hot air at 180 ° C. was blown under a pressure of 6 to 8 kg / m ² to instantaneously inflate, and the presence or absence of peeling of the cured film and airtightness were visually observed. As a result, in Comparative Example 1 and Comparative Example 2, the cured film was peeled off and the airtightness was not good although the degree was different. On the other hand, Examples 1 to 3
Showed that the cured film did not peel off and had good airtightness.
Table 1 shows the above results.

Examples 4 to 6 Table 2 shows the results obtained by using the silicone emulsion used in Example 1 and changing the particle size and addition amount of carbon black as shown in Table 2. In addition, carbon black uses what was emulsified using water in the presence of an emulsifier,
The addition ratio of carbon black was expressed as a percentage of the weight of carbon black to the weight of silicone.

[0057]

[Table 2]

Example 4 is an example in which carbon black was not added. However, the coating surface was white, and there was no strike-through and uncured coating composition, no stain on the coated surface, and no loss of the cured product. Although the result of the inflation test was good, the combustion test was only slightly good because carbon black was not added.

In Example 5, the amount of carbon black added was about four times that of Example 1. As a result, the coating surface became considerably blacker than that of Example 1, and there was no strike-through and uncured of the coating composition. There were stains on the coating surface and falling off of the cured product. The results of the kneading test and the inflation test were also poor. And the result that it was easy to be peeled off because the added amount of carbon black was large.

In Example 6, the amount of carbon black added was the same as in Example 1, but carbon black having a large average particle diameter was used. As a result, the coating surface became slightly darker than in Example 1, and there was no strike-through and uncured of the coating composition.
There was falling off of the cured product. In addition, the results of the kneading test and the inflation test were poor, and the combustion test also failed.

From the above results, when carbon black is not added, the flame retardancy is reduced, and when the addition ratio of carbon black is larger than the range of the present invention, the adhesion is reduced. Further, when carbon black having a large average particle diameter exceeding the range of the present invention is used, flame retardancy is reduced and adhesion is also reduced. Therefore, it is understood that it is necessary to have an appropriate average particle diameter and to blend carbon black in an optimal amount.

FIG. 1 and FIG. 2 show micrographs of the cross section of the base fabric of Example 1 of the present invention. FIG. 1 shows that a cured film having a thin and uniform thickness is formed according to the surface shape of each base fabric fiber. FIG. 2 is a photograph in which the cross section is further enlarged, and shows that the coating composition is well formed without the strike-through of the coating composition between the yarns of the woven fabric.

[0063]

According to the present invention, when a sheet having a cured film obtained by coating the coating composition of the silicone emulsion solution of the present invention on a base fabric and using the air-bag is used, the heat resistance to high-temperature gas generated from the inside of the inflator during operation and It has excellent mechanical properties against intense movement during expansion, and has excellent airtightness against high-pressure gas during expansion, and is easy to process, has high production efficiency, and has excellent flame-retardant properties.

[Brief description of the drawings]

FIG. 1 is a micrograph of a cross section of a base fabric of Example 1 coated with a silicone composition of the present invention.

FIG. 2 is a micrograph showing a further enlarged cross section of the base fabric of Example 1 coated with the silicone composition of the present invention.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) D06M 15/643 D06M 11/00 Z F-term (reference) 3D018 BA04 3D054 CC26 CC30 CC45 FF01 FF02 FF17 4J038 DL031 KA02 MA08 MA10 MA14 NA11 NA14 NA15 NA24 PB07 PC10 4L031 BA02 DA00 DA16 4L033 AB04 AB05 AC05 AC15 BA94 BA96 CA59 CA70 DA00

Claims (7)

[Claims] An emulsion having an average particle size of 50 nm or more.
A coating composition comprising a silicone emulsion solution in the range of 800 nm. 2. The coating composition according to claim 1, which comprises an emulsified flame retardant. 3. The coating composition according to claim 2, wherein 0.1 to 25 parts by weight of carbon black is used as the flame retardant based on 100 parts by weight of silicone. 4. A sheet comprising a support and a cured film formed by curing the coating composition according to claim 1 to a thickness of 40 μm or less. 5. The sheet according to claim 4, wherein the support is a base cloth made of a yarn of 420 denier or less. 6. An air bag using the sheet according to claim 5. 7. A seat belt using the seat according to claim 5.