Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
  • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
  • B60R21/23—Inflatable members
  • B60R21/235—Inflatable members characterised by their material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/12—Layered products comprising a layer of synthetic resin next to a fibrous or filamentary layer
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
  • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
  • D06N3/18—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with two layers of different macromolecular materials
  • D06N3/186—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with two layers of different macromolecular materials one of the layers is on one surface of the fibrous web and the other layer is on the other surface of the fibrous web
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
  • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
  • B60R21/23—Inflatable members
  • B60R21/235—Inflatable members characterised by their material
  • B60R2021/23504—Inflatable members characterised by their material characterised by material
  • B60R2021/23509—Fabric
  • B60R2021/23514—Fabric coated fabric
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
  • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
  • B60R21/23—Inflatable members
  • B60R21/231—Inflatable members characterised by their shape, construction or spatial configuration
  • B60R21/232—Curtain-type airbags deploying mainly in a vertical direction from their top edge

Definitions

• This invention relates generally to coated inflatable fabrics and more particularly concerns airbag cushions to which very low add-on amounts of coating
• inflatable fabrics are primarily for use in automotive restraint cushions that require low
• inventive fabric utilizes an inexpensive, very thin coating to provide such necessarily low permeability levels.
• the inventive coated inflatable airbag possesses a coating comprising an elastomeric material (or materials) coated on the target fabric wherein the elastomeric
• the coating is then applied to the airbag surface in an amount of at most
• the inventive airbag exhibits
• a characteristic leak-down time (defined as the ratio of inflated bag volume to bag
• Airbags for motor vehicles are known and have been used for a substantial
• a typical construction material for airbags has been a polyester or nylon
• bags is typically a woven fabric formed from synthetic yarn by weaving practices that are well known in the art.
• the coated material has found acceptance because it acts as an impermeable
• This inflation medium is generally nitrogen, helium, or
• Airbags may also be formed from uncoated fabric which has been woven in a
• Silicone coatings typically utilize either solvent based or complex two
• bag is usually 0.5 - 1.2 oz/yd 2 . Very different from driver and passenger side air bags,
• a side curtain bag which emerged in the in late 1990's, are intended to protect occupants during side impact and roll over collisions.
• a side curtain bag usually has higher
• silicone exhibits very low tensile strength and low tear
• Patent 5,945,186 to Li et al. would not provide long-term gas retention; they would
• airbag fabrics thus aid in providing a small degree of sustained gas retention within
• driver-side airbags are generally mounted within a vehicle.
• Passenger-side airbags also comprise relatively
• Another object of the invention is to provide an inexpensive side
• a further object of this invention is to provide an highly effective airbag coating formulation which may be applied in very low add-on amounts
• object of this invention is to provide an airbag coating formulation which not only
• object of the invention is to provide a low permeability side curtain airbag possessing a
• this invention is directed to an airbag cushion comprising a coated
• this invention concerns an airbag cushion comprising a coated fabric, wherein said
• this invention encompasses a coated airbag cushion which exhibits a rolled packing
• volume factor (measured as unrolled fabric length the rolled diameter of the airbag
• the invention serves as the time constant in describing the pressure decay of air bag.
• the coating on the bag must be strong enough to withstand the shock and
• Bag volume(ft 3 ) t (seconds) X3600
• the resultant measurement in time would be at least 5 seconds.
• time is greater than about 9 seconds; more preferably, greater than about 15 seconds;
• the term “leak-down time” maybe measured as the amount of time required for at half of the introduced inflation gas to escape from the target airbag after initial peak
• this measurement begins the instant after peak initial pressure is reached upon inflation (such as, traditionally, about 30 psi) with a standard
• the inventive airbag must retain at least 25%o, preferably 50% or higher, of its inflated gas volume 5 seconds subsequent to
• this time is 9 seconds, more preferably 15
• the inventive elastomeric coating composition must comprise at least one
• the elastomer that possesses a tensile strength of at least 1,500 psi and an elongation to break of greater than about 180%).
• the tensile strength is at least 3,000 psi
• preferred elongation to break is more than about 200%>, more preferably more than
• the coating will most preferably (though
• the required coatings on side curtain airbags are very high, at least 3.0 ounces per square yard on each side of the bag
• the inventive coatings exhibit excellent heat aging and humidity aging characteristics.
• elastomeric compositions are, specifically, polyamides, polyurethanes, acrylic elastomers, hydrogenated nitrile rubbers (i.e., hydrogenated NBR), butyl rubbers,
• EPDM rubbers i.e., fluoropolymers and copolymers containing
• such elastomers may or may not be cross-linked on the airbag surface.
• the elastomer is a polyurethane and most preferably is a polycarbonate
• polyurethane elastomer Such a compound is available from Bayer Corporation under
• Impranil® including Impranil® 85 UD, ELH, and EHC-01.
• Other acceptable polyurethanes include Bayhydrol® 123, also from Bayer; Ru 41-710, EX 51- 550, and Ru 40-350, both from Stahl USA. Any polyurethane, or elastomer, for that
• elastomers may be added in multiple layers if desired as long the required thickness for
• the overall coating is not exceeded.
• the mulitple layer coating system
• thickeners are thickeners, antioxidants, antiblocking agents, crosslinking agents, surfactants, flame retardants, coalescent agents, adhesion promoters, and colorants.
• a dispersion either solvent- or
• a polyurethane having a viscosity of about 8000 centipoise or greater.
• a polyurethane is potentially
• polyurethanes such as WitcobondTM 253 (35%> solids), from Witco, and Sancure, from
• EPDM such as EP-603A rubber
• butyl rubber such as Butyl rubber latex BL-100, from Lord Corporation
• acrylic rubber elastomers
• HyCarTM from BFGoodrich. This list should not be understood as being all-inclusive
• the preferred elastomer will not include any silicone, due to the extremely low tensile strength (typically below about
• elastomer and topcoat does not exceed 2.5 ounces per square yard.
• elastomers comprising certain polyester or polyether segments (such as polypropylene
• compositions are heat stabilizers, flame retardants, primer adhesives, antiblocking agents
• a potentially preferred thickener is marketed
• NATROSOLTM 250 HHXR by the Aqualon division of
• a flame retardant is also preferably added to the compounded mix.
• One potentially preferred flame retardant is AMSPERSE F/R 51
• Primer adhesives may be utilized to facilitate
• the elastomer although it is preferable for the elastomer to be the sole component of the entire elastomer composition in contact with the fabric surface, it is possible to utilize
• adhesion promoters such as isocyanates, epoxies, functional silanes, and other such adhesion promoters, such as isocyanates, epoxies, functional silanes, and other such
• adhesive primer coating may be applied directly to the fabric before applying the
• inventive high strength elastomeric coating to assure great adhesion strength.
• a topcoat component as with potential silicones, as noted above, may also be any topcoat component.
• side curtain airbag uses a nonwoven fabric on top of the silicone coating to provide the
• crosslinking agents are, without limitation, melamine-formaldehyde resin,
• topcoats possessing significantly higher hardness and softening point properties possessing significantly higher hardness and softening point properties.
• a topcoat may also perform various other functions, including, but not limited to,
• topcoat materials thus can be selected from, besides
• silicones a group of organic polymer resins that have higher softening point and
• polyurethanes polyacrylates, epoxy resins, ethylene-vinyl acetate copolymers,
• fluoropolymers fluoropolymers, polyamides, and polyesters.
• Airbag fabrics must pass certain tests in order to be utilized within restraint
• One such test is called a blocking test which indicates the force required to
• this time is greater than 50 grams, or the time required to separate the fabrics utilizing a
• talc talc
• silica silicate clays
• starch powders talc
• topcoat polymer talc
• composition does not exceed 2.5 ounces per square yard (and
• preferred elastomers in this invention may be deleteriously affected by high heat and
• Antioxidants, antidegradants, and metal deactivators may be utilized for this purpose. Examples include, and are not intended to be limited to,
• Irganox® 1010 and Irganox® 565 both available from CIBA Specialty Chemicals.
• This topcoat may also provide additional protection against aging and thus may include
• topcoat aging improvement materials such as, and not limited to, polyamides, NBR
• formaldehyde resin polyacrylate, silicones, polyacrylates, fluoropolymers and the like,
• the elastomer composition does not exceed the 2.5 ounces per square yard (preferably much less than that, about 1.5 at the most) of the
• additives may be present within the elastomer composition, including, and
• silicones may be applied on certain airbags within this specification.
• the resultant coating exhibits large thickness variations on the fabric surface or forms a
• Transfer roll coating methods (such as reverse roll, calender roll ,and
• gravure roll may also be used since it can provide a continuous and uniform coating on the fabric. Extmsion coating and slot die coating methods are also possible as long as
• the airbag base fabric in accordance with the present invention is preferably a woven
• Such yam preferably has a linear density of about 105 denier to about 840 denier, more
• Such yams are preferably formed from
• filaments wherein the filaments have linear densities of about 6 denier per
• such substrate fabric will be formed from fibers of nylon, and
• nylon 6,6 most preferred is nylon 6,6. It has been found that such polyamide materials exhibit
• Such substrate fabrics are preferably woven using fluid jet weaving machines as disclosed in U.S. Patents
• the inventive airbag must exhibit extremely low permeability and thus must be what is
• side curtain airbag
• airbags (a.k.a., cushions) must retain a large amount of inflation gas during a collision
• Any standard side curtain airbag may be utilized in combination
• inflation gasses may flow during inflation. Such open areas thus produce pillowed
• some inflatable airbags are produced through the simultaneous weaving of two separate layers of fabric which are joined together at certain strategic locations (again, to form the desired pillowed
• the base airbag fabrics do not provide much help in reducing
• the utilized one-piece airbag is made from a
• inventive airbags function extremely well with low add-on coatings below 1.5 and as
• the inventive coating composition provides similar low permeability benefits to
• inventive coatings themselves clearly provide a marked improvement over the standard, commercial, prior art silicone
• coatings (which must be present in amounts of at least 3.0 ounces per square
• inventive coating may also be beneficially applied to a side curtain bag with less tight constmction.
• Traditional woven side curtain bags utilize
• bag has a constmction of 54 -57 yams per inch.
• the inventive coating actually provides a very low permeability
• airbag may be constructed to a cylindrical shape having a diameter of at most 23
• Standard rolled packing diameters are at least 25 millimeters for commercially
• packed diameter should be at least about 18.8. Preferably this quotient should be about
• silicone-based materials i.e., relatively thick, 4.0 ounces per square yard, for example, silicone-based materials
• side curtain airbags provide definite improvements in gas retention and inflation times
• the ultimate user may utilize much lower inflation pressures (i.e., 15-20 psi, and
• inflators and bags and fabrics which need to withstand lower physical demands upon inflation.
• the elastomer composition of this invention was preferably produced in
• the compounded composition's viscosity measured about 15,000 centipoise by
• the bag was then dried at an elevated
• scrape coating may also be followed to
• knife coating includes, and is not limited to, knife coating, in particular knife-over-gap table, floating
• the final dry weight of the coating is
• the resultant airbag cushion is substantially
• Resin 25-40% solids content in solvent 100 Irganox® 1010 (stabilizer) 0.5 DE-83 R (flame retardant) 10
• Each coated bag was first subjected to quick inflation to a peak pressure of 30 Psi. Air
• the resins are silicone rubbers.
• Examples 10 and 11 show some limitations, polyester based elastomers
• Natural rubber, SBR, chloroprene rubbers and others containing unsaturated carbon double bonds have
• Elastomers that have good physical properties and excellent resistance to hydrolysis and oxidation are preferred for this application.
• segments are the prefe ⁇ ed materials for this application.
• the airbag of Example 3 exhibited a sliding coefficient of friction constant of
• a comparative thick silicone-coated side curtain airbag which included a
• non-woven layer exhibited a constant of about 0.8.
• FIG. 1 depicts the side, inside view of a vehicle prior to deployment of the
• FIG. 2 depicts the side, inside view of a vehicle after deployment of the
• FIG. 3 depicts a side view of a side curtain airbag.
• FIG. 4 provides a side view of a side curtain airbag container.
• FIG. 5 provides a cross-sectional perspective of the stored airbag within the
• the vehicle 10 includes a front seat 12 and a
• curtain airbag (not illustrated). Also present within the roofline 20 is an inflator
• FIG. 2 shows the inflated side curtain airbag 26. As noted above, the airbag 26
• FIG. 3 shows the side curtain airbag 26 prior to storage in its uninflated state
• FIGs. 4 and 5 aid in understanding this concept through the viewing of the
• the preferred packing volume factor is about 21.6.
• An airbag cushion comprising a coated fabric, wherein said fabric is coated with an

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Air Bags (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Woven Fabrics (AREA)
• Laminated Bodies (AREA)

Priority Applications (5)

Applications Claiming Priority (6)

Publications (1)

Family

ID=27407047

Family Applications (1)

Country Status (7)

Cited By (8)

Families Citing this family (7)

Citations (6)

Family Cites Families (1)

• 2000
  • 2000-06-15 BR BR0006934-5A patent/BR0006934A/pt not_active IP Right Cessation
  • 2000-06-15 AU AU54932/00A patent/AU5493200A/en not_active Abandoned
  • 2000-06-15 EP EP00939924A patent/EP1121276A4/de not_active Withdrawn
  • 2000-06-15 CA CA002340903A patent/CA2340903A1/en not_active Abandoned
  • 2000-06-15 CN CNB008016992A patent/CN1173848C/zh not_active Expired - Lifetime
  • 2000-06-15 WO PCT/US2000/016561 patent/WO2000078577A1/en active Application Filing
  • 2000-06-15 JP JP2001504760A patent/JP4597447B2/ja not_active Expired - Lifetime

Patent Citations (6)

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