MXPA96004728A - Difficult flammable fabrics, containing polyester fibers modified with phosphorus, air cushions for protection against shock, manufactured with such fabrics and used - Google Patents

Abstract

Uncoated fabrics are described, having a gas permeability equal to or less than 80 dmü of air per minute per square decimeter, with a pressure drop of 500 Pa (measured according to DIN 53887), and which have at least two systems of yarns composed of parallel yarns, made of high strength polyester filament yarns and with a yarn count between 150 and 700 dtex, as well as a title of individual fibers equal to or less than 7 dtex. The fabrics are characterized in that the polyester is a copolyester modified with phosphorus, which contains in the polymer chain a bifunctional phosphorus compound in an amount of between 0.1 and 5% by weight, based on the amount of phosphorus. With these fabrics can be made air cushions "airbags" for protection against shocks, they are coating and hardly inflammable

Description

DIFFICULT FLAMMABLE FABRICS, CONTAINING POLYESTER FIBERS MODIFIED WITH PHOSPHORUS, AIR CUSHIONS FOR PROTECTION AGAINST SHOCK, MANUFACTURED WITH SUCH FABRICS, AND THEIR UTILIZATION.

The present invention relates to hardly inflammable fabrics, with a high gas tightness, to airbags for protection against shocks containing these fabrics, as well as to the use of these fabrics for the manufacture of cushions. Airbag "air cushions" are inflated with air in an instantaneous manner, in the case of an explosion, in the event of an accident and are intended to protect against injuries caused by an airbag. crash to passengers of vehicles, especially to the driver of automobiles. The cushions of a re airbags are manufactured in part from fabrics with a gas-impermeable coating, which have one of the faces of the cushion a gas-permeable filter fabric, or a segment of filter cloth or an opening In the development work of textile components of importance for safety in automobiles, resistance occupies the first place. When the opening of the air cushion% va? rbag '' is triggered, it remains extended in the interior of the vehicle in the form of relatively large textile surfaces. In case of fire as a consequence of the accident, these textile surfaces pose a risk to the occupants of the vehicle, in a similar way to what is known in the case of curtains in homes. From JP-A-91- 167,312, hardly inflammable polyester fibers are known for the manufacture of fabrics, which in turn are suitable for the manufacture of air cushions% airbags. The content of said document describes only airbags of coated fabrics. This type of fabric does not need to have a special tightness to the gas already in origin, since the gas tightness is mainly achieved by means of the coating layer. Of the behavior of the fabrics with coating in case of fire, it is not possible to take immediate deductions on the behavior of uncoated fabrics in case of fire. Therefore, from the aforementioned JP-0-19- 167,312 it is not possible to draw conclusions about the behavior in case of fire of fabrics s n coating and prepared in a gas-tight manner. According to the example of said document, the title of the yarns used is dtex 833 f 96, so that the title of the individual filaments is accordingly 8.7 dtex. The use of uncoated fabrics for the manufacture of airbags has already been proposed, for example in EP-A-453 678, EP-B-442 373 or EP-B-509 399. tissues because of the small title of their threads and individual filaments, have a higher risk of fire than fabrics made with larger yarn titles and individual filaments.In these documents does not appear any indication of the use of tissues hardly inflammable for the manufacture of air cushions "" "airbags '' By EP-A-661 393 are known polyester threads of high strength and hardly flammable. Said document does not contain any kind of indications on the use of these threads for the manufacture of hardly inflammable fabrics prepared in a gas-impermeable manner. With regard to the growing demands of safety in motor vehicles, there is still a need for hardly inflammable fabrics, usable without coating and gas-tight, which in turn can be used for the manufacture of air cushions " "to rbags." Therefore, the object of the present invention is to propose fabrics for the manufacture of air cushions? * A? Rbags '', which have the necessary properties, of importance for the safety, of the fabrics already known and which also have flame retardant properties. In an air cushion 'a? Rbag' 'this is of great importance for the gas-tight part and for the gas-permeable part, depending on its construction. However, it has surprisingly been found that this type of fabric can be manufactured using polyesfilaments that are difficult to flammable and modified with phosphorus. The invention relates to uncoated fabrics having a gas permeability equal to or less than 80 drn3 of air per minute per square decime with a pressure drop of 500 Pa (measured according to DIN 53 887), and having at least two systems of yarns with parallel yarns, made from high-strength polyesfilaments and having a yarn count of between 150 and 700 dtex, but preferably between 2200 and 550 dtex, as well as a individual title of f? bV * s equal to or less than 7 dtex, but preferably equal to or less than 4 dtex. The fabrics recommended in the invention are characzed in that the polyesis a copolyesmodified with phosphorus, which contains in the polymer chain a bi-functional phosphorus compound in an amount of between 0.1 and 5% by weight, but preferably between 0.2 and 0.8% by weight, based on the amount of phosphorus. The fabrics recommended in the invention can consist, either in a small part of them or totally, of the filaments of filaments of high strength and modified with phosphorus defined above. Thus, for example, it is possible to configure only one of the yarn systems forming the fabric advocated in the invention, manufacturing it entirely or only partly from these yarns. A skilled technician can calculate in each individual case, by means of routine tests, the necessary quantity of filaments of high strength filaments and modified with phosphorus defined above, for example oriented by the resistance desired for the tissues. By using the polyesfibers modified with phosphorus, the difficulty of inflammation of the fabrics made with them can be increased. For the purposes of this description, a non-flammable fabric is to be understood as a raw fabric having a combustibility test according to the standard DTN 4102 / B2, a shortotal combustion time, at least by factor 5, but preferably in factor 10, than the combustion time of a comparable raw maal in polyesnot modified with phosphorus, and in which, according to DIN 54336, no subsequent residual combustion takes place with a time of application of the flame between 3 and 15 seconds and according to DIN 54 333 with a flame application time of 3 seconds. In addition to the high strength and phosphorus-modified filament yarns defined above, a portion of the yarns forming the fabric may consist of filament yarns not modified with phosphorus and of high strength. Preferably, at least one direction, for example the direction of the weft or the direction of the warp, of the fabrics recommended in the invention, is formed entirely with the filaments of high strength and phosphorus-modified filaments defined above; particularly preferably, both directions are formed with this type of filament yarns. The fabrics recommended in the invention may consist of two or more yarn systems; Two yarn systems (warp yarn bundles and yarn bundles) are preferably provided. Of particular advantage, fabrics consisting of two yarn systems are used, which consist respectively of a percentage of at least 95% of the filaments of high-strength and phosphor-modified filaments defined above. The gas permeability to fabrics manufactured according to the invention may vary within wide limits. In the part, as it were, gas-tight, the gas permeability is normally equal to or less than 12 drn3 of air per minute, per square decimeter with a pressure drop of 500 Pa (measured according to DIN 53 887). ). In the part characterized as gas permeable, gas permeability is normally between 12 and 80 dm3 of air per minute, per square decimeter, with a pressure drop of 500 Pa (measured according to DTN 53 887) . The measurement of gas permeability is carried out in accordance with DIN 53 887 in a fabric with a measuring surface of 100 crn2 and with a pressure drop (measuring pressure) of 500 Pa. Especially preferred are the uncoated fabrics, as defined above, whose high strength polyester yarns have a maximum tensile strength greater than 55 cN / tex and a stretch of more than 15% under maximum tensile strength. The measurement of the maximum tensile strength and stretching under the maximum tensile strength of the polyester yarns used is enhanced according to the DTN 53 830 standard. Especially preferred are coated fabrics, as defined above, whose high-strength polyester yarns have a thermal shrinkage of less than 9% at a temperature of 200 ° C. The measurement of the thermal contraction (contraction with high temperature air) of the polystyrene yarns that are used, is carried out in accordance with DIN 53 866, 3 * part, at a temperature of 200 ° C , in samples of threads that remain hanging freely, with a treatment time of 15 minutes. 10 meters of rope section are used with a tension of 0.5 cN / tex on the winder. Especially preferred are uncoated fabrics, as defined above, whose high strength polyester yarns are unprimed. The uncoated fabrics made according to the present invention preferably have a thick curtain fabric weave, a "Veps" ribbed weave, a cross twill weave, a crepe weave or a modified barley grain weave. The calculation of the preparation of the density of the fabric is carried out according to DIN 53 853. Fabrics with these ligaments are already known per se, for example from EP-B-442 272 and EP-B-509 399, which The descriptions also form an integral part of the content of the present description. The uncoated fabrics manufactured according to the invention preferably have a surface weight of less than 300 gr / rn2, but more preferably a weight of less than 240 gr / rn2, and a fabric thickness of less than 0.45 nm, but preferably less at 0.35 rn. The measurement of the weight per unit area of fabric manufactured according to the invention is carried out in accordance with DIN 53 854. The thickness measurement of the fabric recommended in the invention is carried out according to DIN 53885, l »part (measuring surface 10 crn2 measuring pressure 50 cN / cm2) "The maximum tensile strength of the uncoated fabric recommended in the invention is preferably greater than 220 daN and its drawing under the maximum tensile force is preferably greater than 25%; both value-es are respectively measured on a strip of fabric 5 cm wide. The high strength filament yarns that are used in fabrics manufactured according to the inventionThey contain polyester filaments which are composed of a phosphorus-modified copolyester. This copolyester can be a random copolymer with groups of repeating esters, provided that said copolymer contains, in the polymer chain, a phosphorus bifunctional compound in the above-mentioned amount. Highly resistant filaments of copolyesters modified with phosphorus are preferably used, which contain the repetitive structure units of the formula T: -0-OC-Ari-CO-O-Ri - (I) and that in the chain (the polymer have component groups of formula II: 0 0 -0-P-R2-C- R3 (TI), wherein: firi represents a bivalent aromatic radical, R1 is a bivalent radical aliphatic or cycloalkyl fat, R2 represents a bivalent radical aliphatic, cycloaliphatic, aromatic or radical, and R3 means a radical monovalent aliphatic, cycloaliphatic, aromatic or aralxph atic. Especially preferred modified polyesters of the above-mentioned type are used, in which fli-i means femlene or naphthylene, and in particular 1,4-phenlene or 2, 6-naft full. Particularly preferred modified polyesters of the above-mentioned type are also used, in which R * represents a radical of the formula -CnH2n-, in which n is an integer between 2 and 6, in particular ethylene, or represents a radical derived from cyclohexand rnetanol. Especially preferred modified polyesters of the above-mentioned type are also used, in which R2 is a radical of the formula -C mH2m-, in which it is an integer between 2 and 10, or else a cyclic radical of an alkaloid with an and 4 and 8 carbon atoms, but preferably with 6 carbon atoms and in which R3 means Ci -C-β-alkyl, cyclohexyl, phenyl or benzyl. If in the formulas of structure defined above some radical means a bivalent aliphatic radical, it should be understood here as branched and especially straight-chain alkylene, for example, alkylene with 2 to 20 carbon atoms, but preferably between 2 and 20 carbon atoms. 8 carbon atoms. Examples of radicals of this type are: ethan-1,2-dulo, propan-l, 3-dnlo, b-tan-l, 4-dial, pentan-1, 5-dial, hexan- 1, 6-dial or octan-1, 8-dulo. If in the formulas of structure defined above some radical means a bivalent cycloaliphatic radical, then it should be understood that these are groups containing carbocyclic radicals with 5 to 8 carbon atoms, but preferably with 6 nuclear carbon atoms. Examples of these radicals are c-Clohexan-1,4-dial or the group -CH 2 -C 6 H 10 -CH 2 - If in the structural formulas defined above some radicals mean aromatic bivalent radicals, then they are heterocyclic aromatic radicals , which can be mononuclear or polynuclear, or especially aromatic radicals of mononuclear hydrocarbons or nuclear pol. In the case of heterocyclic aromatic radicals. these have in particular one or two volumes of oxygen, nitrogen or sulfur in the aromatic nucleus. The polynuclear aromatic radicals can be condensed together, or they can be combined with each other by means of CC compounds or by means of groups of bridges, such as -0-, -S-, -CO- or -C0-NH- . The valence bonds of the aromatic divalent radicals can be in position * for '' or in a comparable position coaxially or parallel to each other, or else in a "relative" position to each other, or in a comparable angular position. The valence links, which are coaxial or parallel to each other, are oriented in opposite directions. An example of coaxial links in opposite directions to each other are the b? Feno-4,4'-dulo links. An example of links oriented in opposite directions to each other are the links of naphtal? N-1.5 or naphthalam-2.6, while the links of naphtha? N-1.8 are all oriented in parallel in the same sense. Examples of preferred aromatic bivalent radicals, whose valence bonds are in the same position for each other or in a comparable coaxial or parallel position, are the aromatic mononuclear radicals, with free valences para-constants, especially 1.4. - Femlene, or else condensed aromatic bmuclear radicals with parallel bonds oriented in opposite directions to one another, in particular 1,4-, 1,5- and 2,6-naphthylene, or aromatic bmuclear radicals, joined by a C-C bond, with coaxial links oriented in opposite directions, especially 4, 4 '-bifemlene. Examples of preferred aromatic divalent radicals, whose valence bonds are to each other in the 'meta' position or in a comparable angular position, are the aromatic mononuclear radicals with constant free valences met-between, in particular the 1,3- phenol or condensed aromatic bmuclear radicals with bonds oriented at an angle to one another, in particular 1, 6-naphthylene and 2, 7-naphthalene, or else aromatic nuclear b-radicals linked by means of a CC bond , with links oriented at an angle to one another, especially 3, 4 '-biphenylene. If any type of radical means bivalent araliphatic radicals, it should be understood that these are groups containing one or more aromatic bivalent radicals, which are combined with an alkylene radical through a valence or the two valences. A preferred example of a radical of this type is the group -C6H4-CH2-. If any type of radicals means aliphatic monovalent radicals, it should be understood that these are branched alkyl and especially straight chain, for example, alkyl with between one and six carbon atoms, especially methyl. If any type of radicals means cycloaliphatic monovalent radicals, it should be understood that these are carbocyclic radical containing groups with five to eight carbon atoms, but preferably with six nuclear carbon atoms. An example of a radical of this type is cyclohexyl. If any radicals are monovalent aromatic radicals, they are then heterocyclic aromatic radicals, which may be mononuclear or polynuclear, or especially aromatic mononuclear or polynuclear hydrocarbon radicals. In the case of heterocyclic arc radicals, they have in particular one or two oxygen, nitrogen or sulfur atoms in the aromatic nucleus. An example of a radical of this type is the femlo or the naftilo. If any type of radicals means monovalent araliphatic radicals, it can be understood that these are groups containing one or more aromatic radicals, which are combined by means of a valence with an alkylene radical. A preferred example of a radical of this type is the benzyl group. All these aliphatic, cycloaliphatic, aromatic or araliphatic radicals can be substituted with inert groups. Substituents which do not adversely affect the intended application are understood as inert groups. Examples of such substituents are alkyl, alkoxy or halogen. If any type of radical means halogen, it is in this case, for example, fluorine, bromine or especially chlorine. Particularly preferably, in the case of the filament and / or monofilament yarns used according to the invention, they are filament yarns or monofilaments of phosphorus-modified polyethylene terephthalate. The filaments of filaments or the high strength monofilaments that are used can be formed from modified polyols, which generally have an intrinsic viscosity of at least 0.5 dl / g, but preferably between 0.6 and 1. , 5 dl / gr. The intrinsic viscosity measurement is carried out in a polyester solution in dichloacetic acid at 25 ° C. The high strength filament yarns used according to the present invention typically have a yarn count of between 150 and 700 dtex, but preferably between 220 and 550 dtex.

The titers of the individual filament fibers in the high strength filament yarns used according to the present invention normally vary in a field equal to or less than 7 dtex, but preferably equal to or less than 5 dtex, especially between 2 and 4 dtex. dtex. Sections of the filaments in the high strength filament yarns used according to the present invention may be optional; for example, it can have an ellipse shape, it can be bilobal or multilobular, it can have a narrow ribbon shape or it can be preferably round. The filaments of high-strength filaments used according to the present invention and made from phosphorus-modified polyesters are also already known as strength supports and supports for the coating layer, for example, in EP-A. A-661 393, the description of which also forms an integral part of the present description. The manufacture of the thermoplastic polymers is carried out according to already known methods, by polycondensation of the corresponding bi-functional components of the monomers, for example, as described in the aforementioned EP-A-661 393. The manufacture of high-strength filaments can be carried out according to known melt-spinning processes, as described for example in the aforementioned EP-A-661 393 document. The fabrics recommended in the invention can be manufactured by known weaving techniques. , as described for example in the aforementioned documents EP-B-442 272 and EP-B-509 399, the descriptions of which also form an integral part of the present description. In case that the smallest possible air permeability is desired, as is particularly desirable in the area of the airbag cover, the fabric must have a preparation with the highest possible density for the selected yarn count. and for the fabric construction chosen, that is to say that the fabric, preferably in the construction as a thick curtain fabric or as a material or as a fluted wick, "repe", should have the maximum possible amount of yarns per unit length in the fabric. direction of the warp and in the direction of the weave, when the fabric is made. The yarn densities of at least one of the fabric yarn systems advocated in the invention are generally at least 15 yarns per centimeter, but preferably at least 20 yarns per cen + irnetro. Also the subject of the present invention are cushions of a re airbags for protection against shocks, containing an uncoated and hardly inflammable fabric, as defined above. The fabrics for this purpose of use preferably have a resis- tance strength according to Mullen equal to or greater than 3,500 kPa, a maximum tensile force equal to or greater than 1,300 N for each 5 cm of width of the fabric, a resistance to equal progressive tear or greater than 100 N, measured according to the Schenkel method, and a stretch equal to or greater than 20% under the maximum tensile force. The indicated properties are calculated as follows: Resistance to scaling according to Mullen: according to the test method standard "Federal Test Method Standard" No. 191 A, method 5122; Maximum tensile strength: according to DIN 53 857, 1Q part; resistance to progressive tearing (rnetodo Schenkel): according to the norm DTN 53 356 (size of the sample 150 * 200 mm in tubular form, valuation according to DIN 53 539, B); stretched under maximum traction force: according to DIN 53 857, part 1Q.

The invention also relates to the use of the fabrics defined above for the manufacture of airbags for protection against shocks.

Claims (13)

NOVELTY OF THE INVENTION CLAIMS

1. - Uncoated fabrics, which have a gas permeability equal to or less than 80 d 3 air per minute per square decimeter, with a pressure drop of 500 Pa (measured according to DIN 53 887), and which have at least two systems of yarns with parallel threads, made of high-strength polyester filament yarns and with a yarn count of between 150 and 700 dtex, as well as a title of individual fibers equal to or less than 7 dtex, characterized in that the polyester is a phosphorus-modified copolyester, which contains in the polymer chain a bi-functional phosphorus compound in an amount of between 0.1 and 5% by weight, but preferably between 0.2 and 0.8% by weight. weight, referred to the amount of phosphorus.

2. Uncoated fabrics according to claim 1, characterized because its permeability to gae is between 12 and 80 dm2 of ai re per minute per square decimeter, with a pressure drop of 500 Pa (measured according to DIN 53 887 standard).

3. Uncoated fabrics according to claim 1, characterized in that its permeability to gae is equal to or less than 12 drn3 of air per minute per square centimeter, with a pressure drop of 500 Pa (measured according to DIN 53 887) ).

4. Uncoated fabrics according to claim 1, characterized in that they consist of two yarn systems, which in turn consist respectively of at least 95% of high strength filament yarns made of phosphorus-modified copolyester.

5.- Uncoated fabrics according to the claim 1, characterized in that the high strength poly ester yarn has a maximum tensile strength, referred to the fineness, greater than 55 cN / tex and a stretch greater than 15% under the maximum traction force.

6.- Uncoated fabrics according to the claim 1, characterized in that the high resistance polyester yarn possesses thermal contraction of less than 9% at a temperature of 200 ° C.

7.-Uncoated fabrics according to the claim 1, characterized in that the high strength polyester yarn lacks sizing.

8.- Fabrics without coating according to the claim 1, characterized in that they have a thick curtain fabric weave, a corrugated worsted material or "reps" wick, a cross twill weave, a crepe weave or a modified barley grain weave.

9. Uncoated fabrics according to claim 1, characterized in that they have a surface weight of less than 300 g / m2 and a fabric thickness of less than 0.45 nm.

10. Uncoated fabrics according to claim 1, characterized in that they have a maximum tensile strength greater than 220 daN and a stretch greater than 25% under the maximum traction force, both values being measured on a 5 cm strip of fabric. width.

11. Uncoated fabrics according to claim 1, characterized in that the polyester modified with phosphorus contains the repetitive structure units of the formula T: -0-OC-Ar-l-CO-O-Rl (T) and in the chain of the polymer has component groups of formula II: 0 0 ~ 0 - P ll - R, - C II - (II) J. in which formulas: Ar * represents a bivalent mononuclear or polynuclear aromatic radical, R * is an aliphatic or cycloaliphatic bivalent radical, R2 represents a bivalent aliphatic radical , cycloaliphatic, aromatic or araliphatic, and R3 means a monovalent aliphatic, clocloaliphatic, aromatic or araliphatic radical.

12. Uncoated fabrics according to claim 11, characterized in that Ar1 means femlene or naphthylene, in particular 1,4-femlene or 2,6-naphthylene.

13. - Uncoated fabrics according to claim 11, characterized in that R * is a radical of the formula -CnH2n- in which n is an integer between 2 and 6, especially ethylene, or represents a radical derived from cyclohexanedimethanol. 1.4.- Uncoated fabrics according to claim 11, characterized in that R2 is a radical of the formula -CfflH2m-, in which rn is an integer between 2 and 10, or represents a cyclic radical of alkanediyl with 4 to 8 carbon atoms, but preferably with 6 carbon atoms; carbon, and because R3 means Ci-Cβ-alkyl, cyclohexyl, phenyl or benzyl. 15. Air cushion "airbag" for protection against shocks, containing an uncoated fabric manufactured according to claim 1. 16. Use of the fabric manufactured according to claim 1 for the manufacture of airbags "airbags" for protection against shocks.