CN1061390C - Light weight tire - Google Patents

Abstract

A tire is described which includes polybenzazole (PBZ) fibers. The PBZ fibers can be used as part of either the carcass of the tire or as the reinforcing belts of the tire or as both. Tires made with PBZ fibers weigh less than do tires made with steel or other organic fibers, therefore the fuel efficiency of vehicles with tires that contain PBZ fibers is greater than that of vehicles that have tires that do not contain PBZ fibers.

Description

Light tyre

The present invention relates to light tyre.

Tire is defined as " centering on the continuous solid body of wheel or the rubber bumper of inflation ", sees Webster's Ninth New Collegiate Dictionary, p.1237, and 1989 by Mer-riam-Webster Inc..Tire is by rubber, fabric, and chemicals and metal (steel) are made, and see Tires, pp.834-861, Vol.16 of the Encyclopedia of Poly-mer Science and Engineering, 1989 by John wiley ﹠amp; Sons, Inc..Pneumatic tire is annular, comprises the compound of the high-performance polymer of outside rubber and fiber outer cover.The enhancing cord that stabilization and crashworthiness wound, endurance, heat-resisting function have been arranged in these tires.

In bias-ply tire, strengthen cord and pass across tire from tyre bead to tyre bead diagonally.For the balance tire intensity, each strengthens casing ply and passes circumferential line symmetrically with 30 °-70 ° drift angle.

Radial is a kind of pneumatic tire, wherein strengthen filament fiber in the layer of wire gauze of cord or the carcass with 60-90 ° tapered cut angle or crown angle with respect to tread center line (also being rotating shaft) radially (from the tyre bead to the tyre bead) arrange.Adopting the steel band in radial is to spend body piles in order to tighten 90, and the rigidity of this band is essential to the function of tire.If there is not the steel band, radial ply tire can be unstable.Except that the steel band, polyester cord and/or steel cord are used for being used for strengthening tire as this characteristic of pressure vessel in the basic structure of tire or " carcass " (carcass be between tire tyre surface and the liner that part of).

When the steel reinforce was used for tire construction, the driving performance of tire made moderate progress; But the weight of tire increases to some extent owing to the weight of steel.The additional weight that steel strengthens tire means that the resistance to rolling that adopts steel to strengthen the vehicle of tire increases to some extent, and this can cause the rising of fuel consumption.Because efficient, cost and environment reason, the fuel consumption that reduces all vehicles are the targets of making great efforts.

In order to replace the steel in the tire with high performance organic fiber, this is tested.But. the organic fiber that these are known, (as to an aromatic polyamide fibers) is because the also not a large amount of employings of its performance issue.These performance issues comprise: the tensile strength deficiency of fiber, so that when adopting the tire of organic fiber instead of steel, can not get suitable performance, thereby under the weight of the tire situation suitable, will use much more organic fiber with the weight that adopts steel enhancing tire.Have found that simultaneously, adopt its ABRASION RESISTANCE of tire and the fatigue resistance of known organic fiber manufacturing not to reach desired level.

Wish to make and the suitable tire of performance of using the steel tire, but its weight is lower than the steel tire significantly.

First aspect of the present invention is the indole-containing poly fiber that is characterized as of tire.

Second tire that the aspect is an indole-containing poly fiber of the present invention is characterized in that this polybenzazole fiber has:

A) tensile strength is at least 4.0GPa;

B) tensile modulus is at least 140GPa;

C) average pore diameter is 25_ or following.

The 3rd aspect of the present invention is that to add in the reinforcing band with polybenzazole fiber be the indole-containing poly fiber tire of feature.

The 4th aspect of the present invention is that the carcass that adds to tire with polybenzazole fiber is the indole-containing poly fiber tire of feature.

The preparation polybenzazole polymers

Employed in this article term gather indoles (" PBZ ") comprise polybenzoxazoles (" PBO ") homopolymers, polybenzothiozole (" PBT ") homopolymers and PBO and/or PBT random, the order and block copolymer.Polybenzoxazoles, polybenzothiozole and polybenzoxazoles and polybenzothiozole random, in proper order, block copolymer explains in the literature, as Wolfe et al., Liquid Crystalline Polymer Compositions, Pro-cess and Prokucts, U.S.Patent 4,703,103 (October 27,1987); Wolfe et al., Liquid Crystalline Polymer Compositions, Pro-cess and Products, U.S.Patent 4,533,692 (August 6,1985)-; Wolfe et al., and Liquid Crystalline Poly (2,6-Benzothiazole) Compositions, Process and Products, U.S.Patent 4,533,724 (August 6,1985); Wolfe, Liquid Crystalline Polymer Composi-tions, Process and Products, U.S.Patent 4,533,693 (August6,1985); Evers, thermooxidatively Stable Articulated p-Benzo-bisoxazole and p-Benzobisthiazole Polymers, U.S.Patent 4,359,567 (November 16,1982); And Tsai et al., Method for MakingHeterocyclic Block Copolymer, U.S.Patent 4,578,432 (March25,1986).The preferred construction unit is to make polymer form lysotropic liquid crystal in the polybenzazole polymers.Preferred monomeric unit is listed in formula (a)-(h).More preferably polymer mainly list in by being selected from (a)-(h) monomeric unit constituted, and most preferred polymer is mainly listed in the several same unit of (a)-(c) and is constituted by being selected from. Poly-(benzo (1,2-d:5,4-d ') Shuan oxazole-2.6-two bases-1.4-phenylene) Poly-(benzo (1,2-d:5,4-d ') two oxazole-2.6-two bases-1.4-phenylene)

Be applicable to that the solvent that forms the polybenzazole polymers slurry comprises the non-oxidizing acid of cresols and energy dissolve polymer.The example of the acids solvent that is suitable for comprises polyphosphoric acid, methanesulfonic acid, high-concentration sulfuric acid and these sour mixtures.Very preferred solvent is polyphosphoric acid or methanesulfonic acid, and most preferred solvent is a polyphosphoric acid.The concentration of polymer in solvent preferably is at least about 7% (weight), more preferably at least about 10% (weight), and most preferably at least about 14% (weight).Maximum concentration mainly is limited by some practical factors, as the solubility of polymer, slurry viscosity as having mentioned.Because the restriction of these factors, the concentration of polymer is not more than about 20% (weight) usually seldom greater than 30% (weight).

Synthetic polymer or copolymer and the slurry that is suitable for of available known method, as at Wolfe et al., (August 6 for U.S.Patent 4533693,1985), Sybert etal., U.S.Patent 4772678 (September 20,1988) and Harris, described in the U.S.Patent 4,847 350 (July 11,1989).According to Gregory et al., U.S.Patent No.5089591 in anhydrous solvent acid under higher temperature and high shear polybenzazole polymers can develop by leaps and bounds into high molecular.

The preparation fiber

With known dry-jet wet-spinning technique spinning slurry is spun into fiber, spinning slurry becomes the slurries long filament of one or more pulp fibers by spinnerets and boundling in this technology.The fiber spinning technology of PBZ polymer is described in U.S.Patent Applica-tion Number 07/985079 (Method for Spining a PolybenzazoleFiber) and 07/985078 (Method for Rapid Spinning of a PolybenzazoleFiber) that own together, permission.

Pulp fibers contacts with a kind of fluid (being the non-solvent of polymer) with dilution solvent wherein after by air gap.Contact with fluid and to impel polymer and separated from solvent, this separation process is commonly referred to as solidifies.After solidifying, most of residual solvent is fallen by flush away or leaching in the every fiber, and fiber wets.See and own together, the explanation of clotting method among the common unsettled U.S.Patent Ap-plication Number 08/110149 (Improved Process for Coagulationand Washing of Polybenzazole Fibers).

Then with the wet fiber drying.The drying means of fiber is entitled as in " Method for RapidDrying of a Polybenzazole Fiber " at unsettled U.S.Patent Application 08/142526 that own together, common and is described.

After fiber is dried, can heat-treat to improve the physical property of fiber it in case of necessity.The heat treatment of PBZ fiber is described in U.S.Patent Ap-plication Serial Number 07/985068 (Rapid Heat Treatment Methodfor polybenzazde Polymer) that own together, permission and 07/985067 (Steam Heat TreatmentMethod for Polybernzazole Fiber).

The application of PBZ fiber in tire

Carcass and reinforcing band bundle are two main reinforcing members of tire.The PBZ fortifying fibre can be used as the part of carcass.Carcass is that part of between the tyre surface of tire and the liner, and carcass is also referred to as the basic structure of tire, and it comprises the casing ply of enhancing.The PBZ fiber also can be used as the material of the circumferential check strap of tire.

In order to can be used in the tire, the PBZ fiber must make it form cord by twisting process, see that Addis Finney is entitled as in " That Left-hand Turn and its Effect onTires " (in the May 1979, issue of Rubber world) literary composition explanation and the illustration about plying cord and cable.The PBZ fiber forms the plying cord by twisting, and " T/10cm " is the twist of every 10cm cord.In case follow two strands or multiply plying cord twisting becoming cable cord together after forming PBZ plying cord.The twist of these cable cords with the cable twist (change/10cm) * the plying twist (change/10cm) represents.The PBZ cord and the cable twist can change between 20 * 20 to 100 * 100 in this application.The twist factor of PBZ cord can be calculated by laxative remedy: the twist factor=(add twisting count/10cm) * (density of the total fiber number/fiber of fiber) ^1/2The twist factor range of the PBZ cord that is adopted in this application is 800 to 3000.Be called greige cord at this stage PBZ plying cord, the greige cord explanation is the cord before the impregnation state.The thickness of these PBZ greige cords is 0.30mm to 0.60mm.

Can be used for making stratiform reinforcing material or stratiform band for greige cord is changed into, greige cord must be flooded cord and/or the cable that formation " was soaked glue " in adhesive, they can be adhered on other parts of tire thereafter.These adhesive can be epoxy adhesive such as glycerine polyglycidyl ether or the compound such as the Pexul of standard ^TM, it is 2, (this compound is also with Vulcanbond-E for two (2 ', 4 '-dihydroxy benzenes ylmethyl)-4-chlorophenol compounds of 6- ^TMTitle sell by Rhone-Poulenc company) or RFL (resorcinol-formaldehyde latex).Also available other suitable adhesive substitutes these adhesive.

Actual immersing glue process is a two-step method, at first cord/cable is immersed in to contain epoxy or Pexul ^TMIn first maceration extract of (as main adhesive component), then cord/cable was placed under 235 ℃ of-250 ℃ of temperature about 60 seconds; Then cord/cable is contacted with second maceration extract that may be RFL (resorcinol-formaldehyde latex), placed then under 230 ℃ of-240 ℃ of temperature about 60 seconds.

After PBZ cord/cable forms, adopt the tire manufacturing technology of standard that they are combined in the tire, then tire is carried out various performance tests.

Because polybenzazole fiber has higher (about 2 times) tensile strength and stretch modulus, the carcass material of the present invention that is used for tyres for passenger cars can be that (or littler) PBZ of two-layer 500 dawn fibercord is equivalent to two-layer 1000 dawn to aromatic polyamide fibers cord (dawn is the weight in grams number of 9000 meters fibers).In view of this reason, behind the employing PBZ cotton tyre cord, cord thickness can be reduced to 0.39mm or the lower thick polyester cord of two-layer 0.67mm of common 1500 dawn that just is equivalent in carcass.

Therefore, replace carcass with PBZ and be possible with the weight that intrafascicular organic fiber and steel bundle reduce tire.The example that weight reduces: (" 195/65R15 " tire designs according to JIS D4202-1982 standard 195/65 R 15 tires, be described as follows: the wide 195mm of tire, tire flat ratio are 65%, " R " to represent radial, wheel rim be 15 inches) adopt the PBZ cord, tire weight may reduce 1.5kg.The reduction of weight is calculated as follows:

Adopt the PBZ cord can reduce weight 500 grams in the carcass;

Adopt the PBZ cord to replace to reduce weight 600 grams with intrafascicular steel;

Owing to reduced the thickness of rubber in the carcass, carcass weight can additionally reduce by 400 grams; This is that carcass only needs less rubber owing to adopted the PBZ cord in carcass.

Have found that, if be used to make the tensile strength that the PBZ fiber of cord has preferably be at least 2.8GPa, more preferably about 4.0GPa, more preferably at least about 5.7GPa and most preferred about 6.9GPa, stretch modulus is preferably at least about 140GPa, more preferably at least about 276GPa with most preferably at least about 380GPa, then the operating characteristic of cord can improve in the tire.

Also finding, is 25_ or littler as the average diameter of fruit fiber mesopore, and the fatigue performance of PBZ fiber that then is used for cotton tyre cord is better.The average diameter of available " small angle X ray scattering " technical measurement PBZ fiber mesopore, this technology can be measured in the fiber pore diameter less than 100_.Have been found that with the hole average diameter to be that 25_ or littler PBZ cord are made the tire of carcass and compared with the identical tire that is 30A or bigger PBZ cord system with the average pore size, its durability is wanted high twice.

A feature of the present invention is only to make tyres for passenger cars (these tires can be the lightest tires) with PBZ cord band and PBZ cord carcass of tyre, and also available steel band and PBZ cord carcass of tyre manufacturing tyres for passenger cars (these tires should overweight the tire of only using PBZ cord system) and available PBZ cord band and with polyester cord carcass of tyre manufacturing tyres for passenger cars (these tires can be lower than other tire cost).

A feature of the present invention is can be only to make that truck/bus tyre (these tires should be the lightest tires) and also available steel band and PBZ cord carcass of tyre are made truck/bus tyre (these tires only should overweight the tire with PBZ cord system) and with PBZ cord band and steel carcass manufacturing truck/bus tyre (these tires should overweight the only tire of usefulness PBZ cord system) with PBZ cord band and carcass.

Following embodiment not will be understood that it is restriction to this specification or claims scope only as an illustration.Except as otherwise noted, all umbers and percentage are all by weight.

The measuring technology that is among the embodiment below to be adopted.

The diameter of hole

Available suitable X-ray equipment (as the Kratkey camera) carries out the measurement of little angle X-linea angulata scattering strength.About 6 meters long fiber sample around measure on the bearing, the X-ray produces under 45KV and 150mA condition, leaches the Cuka line for measuring usefulness with the nickel colour filter.

The collimating slit of Kratkey camera is that 42mm (length) * 0.14mm (wide), reception slit are 10mm (length) * 0.14mm (wide).

Measure the equator of fiber sample (angle of scattering 0.1 degree-3 degree) scattering to go on foot wide 0.25 degree, accumulated time 30 seconds or longer time, backscatter is to compensate from the logical following formula of the diffuse transmission measuring result of sample and air.

I is actual scattering strength in the formula, and the I sample is the mensuration intensity of mensuration intensity, the I air of sample when being no sample.In order to determine the absorption coefficient of sample, after sample is measured, measure the intensity of 0 degree angle of scattering.Adopt the Guinier curve can determine pore size.

With square the logarithm mapping of scattering vector (k), at K to scattering strength ²Value is from 0-0.01_ ²Fitting a straight line in the scope, the average diameter of hole can be calculated with the slope of following formula from this straight line. $D=2\sqrt{2K}$

The fatigue test of impregnation cord

The disk fatigue test results represents that with the percentage that intensity keeps the tubulose fatigue test results is with a minute expression, and test method is drafted according to JIS-L1017-1983.

Tire test

The basic terms and the condition of test tire are seen ASTM F538-91b and ASTMF551-89

The mensuration of high-speed durability and load durability adopts indoor drum test, and test method is drafted according to JIS-D4230-1986.

In the destruction life-span of tire, tyres for passenger cars is expressed as index (Table III) with respect to 100, truck and bus tyre are expressed as index (Table V) with respect to 100.

Breaking of occurring of carcass after travelling through the scheduled time studied, and its durability is expressed as index (Table III) with respect to 100, truck or bus tyre is expressed as index (Table V) with respect to 100 tyres for passenger cars.

Resistance to rolling is in indoor drum test aircraft measurements, and tyres for passenger cars is expressed as index (Table III) with respect to 100, truck and bus tyre are expressed as index (Table V) with respect to 100.This index is to be the mean value of testing under the 20-150km/h in speed.

Take sensory testing and be by vehicle in the actual travel of process of the test by panelist's subjective assessment.To tyres for passenger cars, take the index (Table III) feeling to be expressed as with respect to 100, truck and bus are expressed as index (Table V) with respect to 100.

The consumption of fuel, to the wheel car be expressed as index (Table III) with respect to 100, to truck

Be expressed as index (Table V) with bus with respect to 100.The result shows, is lower than vehicle without the tire of pbo fiber system with the fuel consumption of the tire vehicle of pbo fiber system.

The high speed endurancing adopts indoor drum tester to carry out, and puts on the tire with the load of appointment, and test speed increases by following segmented mode:

80km／h 120min

120km／h 30min

130km／h 30min

140km／h 30min

150km/h 30min occurs destroying until observing.

The load durability

Adopt indoor drum tester that tire is applied constant rotating speed, the load of tire increases by following segmented mode:

Tyres for passenger cars

Speed=80km/h

Load

100% maximum load 4hrs

110% maximum load 6hrs

150% maximum load 6hrs occurs destroying until observing.

Truck/bus tyre

Speed=65km/h

Load

70% maximum load 7 hours

90% maximum load 16 hours

105% maximum load 24 hours

Steering force

On drum tester, measure the horizontal skid force of tire with 10km/h, 2 degree drift angles.Steering power is that steering force is divided by drift angle.To tyres for passenger cars, it is expressed as index (Table III) with respect to 100, truck and bus tyre is expressed as index (Table V) with respect to 100.This is meant the weft yarn radical of per 10 centimetres of carcass cords carcass weft yarn radical.This is meant the fracture strength of a body cord intensity of body cord, is to use the Instron stretching test machine determination.

Embodiment 1 tyres for passenger cars

Two-layer greige cord is twisted and made to the aromatic polyamides and the polybenzazole fiber of polyester, para-orientation.

Each greige cord is processed into the cord/cable that soaked glue with two step gum dipping process methods.The impregnation Treatment Solution and the treatment temperature of impregnation processing usefulness are listed in Table I, and the performance of cord is listed in Table II behind the impregnation.In Table II, have 5 kinds with the cord of PBO system such as example A, B, C, D and E (Table II), a kind ofly use cord to an aromatic polyamides system as a means of contrast (Table II).In order to contrast, in Table II, also has a kind of cord with polyester.

Tired and the tubulose fatigue test results demonstration of the disk that Table II is listed is if aperture diameter is that 25_ or fatigue strength littler then pbo fiber have improved in the pbo fiber, as Sample A, B and C.

Strength factor be tensile strength divided by cord thick square numerical value.The intensity of the high more expression cord per unit thickness of this value is high more.Therefore, strength factor is for reducing important the measuring of tire weight fibre property.

Adopt the carcass of these cord systems of soaking glue and enhanced beam to bring to make tyres for passenger cars and tire is made a service test.Each tire is formed and result of the test is listed in Table III.

Table I

	PBO	Right-aromatic polyamides	Polyester
The first impregnation solution	Epoxy	Epoxy	Pexul
First furnace temperature	250	250	240
The second impregnation solution	RFL	RFL	RFL
Second furnace temperature	235	235	235

" EPOXY " is glycerine polyglycidyl ether (trade name Denakol ^TMSell by Nagase)

" RFL " is resorcinol-formaldehyde-latex

" Pexul ^TM" be 2, the product of two (2 ', 4 '-dihydroxy benzenes ylmethyl)-4-chlorophenols of 6-(is also referred to as Vulcabond E ^TM, sell by Rhone-Poulenc), with impregnation solution impregnation 1 second kind dry then 60 seconds.Table II

Sample	A	B	C	D	E	F	G
								Fiber type	PBO	PBO	PBO	PBO	PBO	Right-the aromatic polyamides polyester
Pore diameter _	20	20	25	30	34	---	---
								Fiber number (dawn)	500	500	500	500	500	1000	1500
Tensile strength GPa	5.5	5.5	5.5	5.5	5.3	3.0	1.2
								Extension at break %	2.0	3.8	3.9	3.8	3.7	4.3	13.8
Stretch modulus GPa	344.2	179.0	169.4	172.1	151.5	480.0	125.0
								Greige cord
Twist T/10cm	72×72	72×72	72×72	72×72	72×72	49×49	39.5×39.5
								The twist factor	1823	1823	1823	1823	1823	1832	1835
Cord thickness mm	0.36	0.38	0.37	0.37	0.37	0.50	0.65
								Intensity kg	30.3	31.8	31.5	32.0	30.7	35.3	25.3
Extension at break %	4.9	5.4	5.3	5.3	5.2	6.6	18.2
								Rubberized cord
Twist T/10cm	72×72	72×72	72×72	72×72	72×72	49×49	39.5×39.5
								The twist factor	1823	1823	1823	1823	1823	1832	1835
Cord thickness mm	0.38	0.39	0.39	0.39	0.39	0.54	0.67
								Intensity kg	27.2	25.8	26.0	25.7	24.3	28.5	23.8
Intensity factor kg/mm 2	188.4	169.3	170.9	169.0	159.8	97.7	53.0
								Load kg during 3% elongation	20.6	18.1	17.8	18.0	17.9	17.0	16.9
Extension at break %	3.7	4.3	4.2	4.2	4.3	4.4
								Hot-air shrinks %	0.0	0.0	0.0	0.0	0.0	0.0
The tired % of disk	53	61	59	40	23	56	63
								Tired minute of tubulose	23.7	265	226	148	119	145	150

Table III

Sample	Tire 1	Tire 2	Tire 3	Tire 4	Tire 5	Contrast 1	Contrast 2
								The band material	A	B	C	D	E	F	Steel
Carcass material	A	B	C	D	E	F	G
								Body cord weft end/10 cm	108	108	108	108	108	108	108
Tire weight kg	9.0	9.0	9.0	9.0	9.0	9.8	10.5
								Body cord intensity kg	26.5	25.8	26.0	25.3	23.9	25.3	22.5
High speed durability index	110	108	105	96	92	98	100
								Load durability index	102	102	102	97	89	97	100
Rolling resistance index	83	85	85	85	85	90	100
								Take the sensation index	115	115	115	115	115	110	100
The steering power index	100	98	98	98	98	97	100
								Fuel consumption index	93	95	95	95	95	98	100

Embodiment 2 trucies and bus tyre

With orientation a aramid fibre and pbo fiber are twisted, make two-layer greige cord.

Each greige cord carries out impregnation to make impregnated cord by the same procedure described in embodiment 1 Table I.

The performance of soaking the glue cord of gained is listed in Table IV.Adopt these PBO cords that soaked glue and/or steel cord to make truck or bus radial, and test the performance of these tires.

The result of the test of the composition of cord and tire is listed in Table V in each tire.Table IV

Sample	H	I	J	K	L	M
							Fiber type	PBO	PBO	Right-aromatic polyamides		Steel	Steel
Pore diameter, _	20	20	-	-	-	-
							Fiber number (dawn)	1500	1500	3000	3000
Intensity GPa	5.5	5.5	3.0	3.0	2.3	2.3
							Extension at break %	2.0	3.8	4.5	4.5	1.7	1.7
Modulus GPa	344.2	179.0	68.8	68.8	194	194
							Greige cord
Twist T/10cm	30×30	44×44	22×22	32×32	3×0.20+6×0.38	3+9+15×0.175+0.15
							The twist factor	1316	1930	1364	1985
Cord thickness mm	0.56	0.58	1.01	1.04	1.16	1.05
							Intensity kg	111.2	98.1	112.8	99.6	192.3	149.7
Extension at break %	4.1	5.4	5.3	5.3	1.7	1.7
							Rubberized cord
Twist T/10cm	72×72	72×72	72×72	72×72
							The twist factor	1316	1930	1364	1985
Cord thickness mm	0.58	0.60	1.03	1.05
							Intensity kg	105.5	92.3	98.1	86.5
Intensity factor kg/mm 2	313.6	256.4	92.5	78.5
							Extension at break %	3.7	4.3	4.2	4.2
Hot-air shrinks %	0.0	0.0	0.0	0.0

Table V

	Tire 1	Tire 2	Contrast 1	Contrast 2	Contrast 3
						The band material	H	L	J	L	L
Carcass material	I	I	K	K	M
						Tire weight kg	41.6	45.3	47.0	50.2	53.8
Body cord intensity kg	107.0	92.6	99.4	85.7	149.2
						High speed durability index	105	106	99	102	100
Load durability index	101	105	95	97	100
						Rolling resistance index	81	83	90	88	100
Take the sensation index	115	110	115	109	100
						The steering power index	100	103	95	96	100
Fuel consumption index	85	89	93	95	100

Claims (10)

1. a tire is characterized in that indole-containing poly fiber, and a) its tensile strength is at least 4.0GPa; With

B) stretch modulus is at least 140Gpa.

2. the tire of claim 1, wherein said polybenzazole fiber is characterized in that they are polybenzoxazole fibers.

3. the tire of claim 2, wherein said polybenzoxazole fibers is characterised in that they have average pore diameter 25_ or lower.

4. the tire of claim 2, wherein said polybenzoxazole fibers is characterized in that they are combined in the enhancing band of tire.

5. the tire of claim 2, wherein said polybenzoxazole fibers is characterized in that fiber combinations is in the carcass of tire.

6. the tire of claim 2, wherein said polybenzoxazole fibers is characterized in that they are combined in the enhancing band and carcass of tire.

7. the tire of claim 1, wherein said polybenzazole fiber is characterized in that they are polybenzothiozole fibers.

8. the tire of claim 7, wherein said polybenzothiozole fiber is characterized in that they have average pore diameter 25_ or lower.

9. the tire of claim 7, wherein said polybenzothiozole fiber is characterized in that they are combined in the enhancing band of tire.

10. the tire of claim 7, wherein said polybenzothiozole fiber is characterized in that they are combined in the carcass of tire.