FI63773B - SMOERJNINGSMEDELKOMPOSITION - Google Patents

Description

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Patent · och rtgiltantyrtllMI '7 AmMcm utbfd och utI. * Krtfton puMfcorad 29. 04.83 (32) (33) (31) Pyy *** y «ueiicw — b ^ m priorttoc 13.02.76 15.10.76 English-England (GB) 5674/76, 42864/76 (71) Dunlop Limited, Dunlop House, Ryder Street, St. James's, London SW1Y 6 PX, England-England (GB) (72) Michael John Kenney, Sutton Coldfield, West Midlands, England-England (GB) (74) Qy Jalo Ant-Wuorinen Ab (54) Lubricant Composition - Smörjningsmedelkomposition (62) This invention relates to a lubricant composition to lubricate the inner surfaces of the collapsed ring.

GB Patent Publication No. No. 1,359,468 discloses a pneumatic tire which, when mounted on a wheel rim for this purpose and filled with n of its in-use operating pressure, has an aspect ratio of 30 and 75¾ files and has a tread width greater than the distance between the flanges of the manure, between the contacting areas of the inner surface when the tire is used in the assembled condition.

The above tire marked a new step forward in the field of safety tires. To date, many attempts have been made to find a solution to deal with tire failures without danger or without the vehicle remaining in place; these previous efforts have focused mainly on two ways of approaching the problem. The first of these was to provide a safety member consisting of a second pressure chamber, special infill or rigid saddle supporting the collapsed tire and the second was to provide the inner surface of the tire with a hole sealing layer to prevent the tire 2 63773 from collapsing. The problem with the latter method is that unless the sealing layer 100% effectively prevents air from escaping, there is a risk that air will escape before the hole is sealed, resulting in the driver driving on a low pressure tire without being aware of the danger. In the case of a conventional tire, this may be more dangerous than a flat tire, as prolonged driving on a low-pressure tire at high speeds is the main cause of the tire exploding on fast roads and the necessary 100% efficiency is in practice a very interpretative goal.

If the use of a tire without additional support is allowed, it will allow it to present various other possibilities. GB Patent Publication No. 1,359,467, it has been proposed to use a combination of a tire and a wheel rim in combination with a liquid lubricant containing a volatile component and a hole sealant so that the hole can be sealed and the low pressure resulting from the evaporation of the volatile substance can be developed in the tire. The sealing of holes in this way has been further developed in FI patent no. 53,277, wherein the volatiles are enclosed and the inner surface of the ring is coated with a gel-like lubricant, and wherein the solid hole sealants are incorporated into the gel-like substance. In this case, the release of volatiles as the ring collapses is followed by the disintegration of the jelly, whereby the hole sealants are applied to the hole and seal it. Gels suitable for use in this system are disclosed in FI Patents No. 55,466 and 60,409.

It is obvious that the purpose of sealing the hole and filling due to evaporation in these cases is not to refill the tire to the working pressure, but simply to provide a low filling pressure of the order of 0.07-0.35 kp / cm in the tire to reduce its degree of compression and thus heat. to reduce when the tire is driven without inflation pressure. This is, of course, completely different from the hole sealing layers and materials of the previous proposals, as the latter methods have failed if they allow the tire pressure to drop by more than just a small fraction.

According to the present invention, the problem of achieving a low inflation pressure has been approached from a new point of view in order to reduce the degree of compression of a collapsed, internally lubricated flat driven tire 3 6 3 7 7 3. α

It has been found that providing the tire with a hole sealing layer 2 capable of maintaining a inflation pressure of about 0.07-0.35 kp / cm in the event of a tire failure allows the tire to run in a compressed manner without the need for volatile liquids and a liquid lubrication system.

The present invention relates to a pneumatic tire in which at least the inner surface of the tread is coated with a lubricant coating to promote the mutual movement of the contacting areas of the inner surface of the tire when the tire is compressed, characterized in that the coating cannot leak from the inner surface by gravity or forces generated inside the tire when the tire is driven under pressure, comprises a jelly-like non-volatile lubricant thoroughly mixed with a particulate solid hole sealant of at least 0.15 mm ^ per mm of coated inner surface of the tire, ranging in size from 7 mesh from particles passing through a BS standard (British Standard) but remaining on a 10 mesh BS sieve up to particles passing through an ISO micron sieve with a particulate solids volume of at least 8% but not more than 66% of the total volume of the coating.

The non-volatile non-volatile lubricant can be formed from a very wide range of blend categories which also include lubricants for lubricating rubber surfaces, for example: (i) Alcohols, monohydric e.g. n-octanol dihydric (diols, glycols) e.g. ethylene glycol, diethylene glycol and propylene glycol trihydric (triols) e.g. glycerol polyhydric (polyols) (ii) Polyalkylene glycols e.g. polyethylene glycols and polypropylene glycol. molecular weights vary

General formula: RO - CH, - CH - O - R11 R1 wherein R, R1 and R11 are alkyl groups or H) 4 63773 (III) Poly (alkylene oxides) e.g. copolymers of ethylene oxide and propylene oxide units which are available under the tradenames "Ucon 50-HB-2000", "Ucon 50-HB-3520", "Ucon 50-HB-5100" and "Ucon 50-HB-250" (iv) Polybutenes

When the gelled lubricant comprises poly (alkylene oxide) or modified poly (alkylene oxide), the gel can be prepared by any suitable method, for example by adding a finely divided filler to the lubricant fluid, especially a colloidal size (200-500 Å) in the form of spheres, rods or tiles. This provides a three-dimensional structure. The three-dimensional network can be mechanically reinforced by the addition of additives (e.g., sodium carbonate or hexamethylenediamine).

The inert filler may be organic or inorganic and comprises silicates in the form of tiles (clays, mica, etc.), rods, fibers (asbestos), or finely divided silica, for example _., ®

Aerosil.

In the preparation of these gels, a strong mixing technique can be used, for example, ultrafast mixers, paint grinders, ultrasonic mixing. The gel can also be prepared using an acrylic polymer as a gelling agent. An acidic emulsion of an acrylic copolymer containing carboxyl groups is added to a lubricant, for example ethylene glycol or glycerol, to form a mobile mixture into which solid particles sealing the holes can be mixed. This mixture is neutralized, for example, with ammonium or sodium hydroxide solution to destroy the emulsion so that the acrylic polymer dissolves to produce a viscous gel. A suitable gel can also be formed by using polybutene as a lubricant and gelling it with a polyolefin, for example polyethylene. This polybutene gel preferably comprises an elastomer which is soluble in polybutene, such as butyl rubber, ethylene-propylene rubber or natural rubber.

According to the present invention, the hole sealing properties of the lubricant layer are sufficient to seal or partially seal the hole in the tread when the inner pressure of the tire is low and thus provides a low inflation pressure to the tire when driven in a compressed state, which reduces tire deflection and thus reduces tire heat.

The tire is preferably a belted ring comprising a belt carcass and a circumferential tread reduction layer. The tread is preferably substantially flat in cross-section both externally and internally, of which the latter is most suitable because in a tire with a recess in the inner surface, very large centrifugal forces develop during rapid driving to eject material into the center of the tread. from the inner surface in the vicinity of the tread edges of the tire. In order for the gelled lubricant to be sufficiently stable so that it does not flow when driven along the inner surface of the tire by gravity, its viscosity

A

preferably at least 2000 N sec / m at 20 ° C.

The sidewalls of the tire are preferably thickened to reduce their radius of curvature during the bending that occurs when the combination is driven in a compressed manner, for example as disclosed in U.S. Pat. 3023/74.

«

The density of the solid sealant consisting of particles is preferably 0.8 to 1.5 g / cm, and a particularly suitable material is crushed rubber and wood powder (sawdust).

It is apparent that in the combination of the present invention, the gelled lubricant layer seals the holes in the tread of the tire by means of solid particles that pass through the hole together with the gel. For this reason, of course, the gel must not be rigid but must be able to drain somewhat and the particulate matter must be evenly distributed around the entire circumference of the ring.

If desired, the gelled lubricant may also include a volatile liquid, such as water, which develops vapor pressure in the ring after sealing the hole when driving in a compressed state.

The invention is explained in more detail below with reference to the following examples.

Example 1:

The PSG gel was prepared by mixing the following substances in the following order: .6 63773

Gel B.308 / 2 (a) 80 g of water 60 g

Gel 3 (b) 60 g of 10 mesh rubber crumb 160 g 360 g of which: (a) Gel B.308 / 2 was a gel prepared as follows:

Ucon 50 HB - 2000 Y3 Y24 318 kg water <7 kg

Aerosil 300 (silica) '30 kg

Sodium chloride 42 g and b) Gel 3 was a gel prepared as follows:

Acrylic emulsion Texicryl 13-1300 37.5 g water 157.3 g 0.880 ammonium 2.6) 5.2 g. water 2.6) to 200.0 g

Four holes were drilled at regular intervals in the center of the tread of a 155/65 to 310 size tire to achieve an air leakage of 50 cm / sec as accurately as possible at a tire pressure of 0.35 kp / cm 2. The holes were closed with 1 1/2 "round nails and the inner tread of the tire was evenly coated with 360 grams of PSG 32. The tire was then mounted on the rim, inflated and fitted to the Mini 1275 GT and the car was driven 155 km at 140 km / h to smooth the gel and Immediately after driving, the wheel was removed and balanced and after two hours the balancing was checked to see if the gel had not moved in the stationary tire.The bike was refitted to the car and the car was taken to a test track where one pound was removed from the tire and immediately afterwards the car was accelerated 90 km / h and was driven at this speed for 2 km, at which point it was stopped and the hole was inspected, it was found that the hole had completely sealed and that the tire pressure had remained higher than 1.05 kp / cm, after which the car was still driven for approx. and the hole point was checked 7 63773 uu Still, no leakage el could be detected. The second nail was then removed and the above set of experiments was repeated. The result was the same as in the first experiment, ie the hole was sealed at a distance of 2 .mu.m. The third and fourth nails were removed, but the result was the same. At the end of Koe-s Arja, the tire pressure had dropped to 1.05 kp / cm ϊϋη.

Example 2:

Gel PSG 49 was prepared by mixing the following substances in the following order:

Castor oil) 115.5 g

Ungelled castor oil was heated to 26.7 g

Antioxidant 0.9 g water 35.5 g

Bactericide 0.4 g 10 mesh rubber crumb 142.0 g 40 mesh rubber crumb 35.5 g

Aerosil 300 3.5 g 360.0 g

As in Example 1, four 50 cm 3 / sec holes were drilled at regular intervals in the center of the tread of a tire of size 155/65 to 310.

In addition, the pressure drop through one hole was measured as follows:

Time Pressure 0 1.76 kp / cm2 15 sec 1/41 kp / cm2 30 sec 1.05 kp / cm2 45 sec 0.77 kp / cm2 2 1 min 0.56 kp / cm2 min less than 0.14

The holes were closed with 1 1/2 "round nails, the inner surface of the tire tread was gel coated around and the tire was run on the road to smooth the gel as shown in Example 1. The wheel was removed from the car and sealed in an oven at 100 ° C for two hours.

After the oven cycle, the ring was removed from the rim and the gel was inspected. The gel had apparently not been affected by the heat and the tire was refitted to the rim and tested on the road with the following results: * β 63773

Experience Km at 80 km / h Tire bead 0 1.72 kp / cm2 2

Nail A removed 2.7 1.48 bp / cm 12.1 1.44 bp / cm2

Nail B removed 2.7 0.77 kp / cm 2 to 12.1 0.86 kp / cm 2

Nail C removed 2.7 0.27 kp / cm 2 12.5 0.33 kp / cm 2

Car stationary

The ring was allowed to cool for 2 to 15 minutes at 0.21 kbps.

Nail D removed 0 0 pcs / cm 2.7 0.14 pcs / cm2 9.7 0.14 pcs / cm2 21.9 0.23 pcs / cm2 33.0 0.25 pcs / cm2

Thus, it was found that although the nail D had been removed and the pressure was allowed to drop to zero, the hole had sealed to 2.7 km of ice and the tire pressure had risen to 0.14 kp / cm and finally to 2 0.24 kp / cm 33 after km.

Example 3: - - - - - -— - #

Gel PSG 51 was prepared by mixing the following substances in the following order:

Ethanediol 150 g

Viscalex HV.30 (carboxylated acrylic 25 g copolymer emulsion, manufactured by Allied Colloids Limited) water 25 g 10 mesh rubber crumb 125 g 40 mesh rubber crumb 25 g 0.880 ammonium 5), n „v4tta s> —12-s— 360 g

Viscalex HV-30 and water were added to the ethanediol to form a mobile mixture to which rubber crumb was added as a hole sealing solid. The mixture was then neutralized with ammonium solution to destroy the emulsion, whereupon the acrylic copolymer dissolves to form a gel.

9 63773 360 grams of gel coated the inner surface of a tire of size 155 / 65-310 evenly and drilled four 50 cm ^ / sec holes evenly in the center of the tread as shown in the previous examples and drove it on the road for 53 km up to 110 kn / t to smooth the gel . The nails were then removed alternately as shown in the above examples with the following results:

Experience Km at a speed of 85 km / h Tire pressure - 0 2.11 kp / cm ^

Nail A removed 2.7 1.97 kp / cm2, Nail C removed 3.2 1.89 kp / cm2

Nail D removed The tire was allowed to collapse to 0 kp / cm ^ completely before driving 4.0 0.17 kp / cm2 9.7 0.24 kp / cm2

Note: a) During this test, the road surface was wet but did not rain, b) Naulca B could not be removed.

The wheel was removed from the car, inflated to 1.76 kp / cm 2 and sealed in an oven at 100 ° C for two hours. After the tire cooled, it was installed in the car and the road test was repeated with the following results:

Experience Km at a speed of 85 km / h Tire pressure - 0 1.83 kp / cm2

Nail A removed 2.7 1.51 kp / cm ^ 12.1 1.58 kp / cm ^

Nail C removed. i 2.7 0.84 kp / cm 2 12.1 0.91 kp / cm 2

Nail D removed The ring was allowed to collapse completely before running 2.7 0.13 kp / cm ^ 9.7 0.17 kp / cm2 The results of this experiment thus showed the same as the previous experiments, i.e. that a very wide range of gels can be used to make effective hole sealants. Also, due to a tire failure, a fully collapsed tire in a stationary car can easily develop pressure when driving it again.

10 63773

Example 4:

Three carboxylated acrylic copolymer gels were prepared using glycerol and diethylene glycol as a lubricant and mixing the ingredients in the order given in the same manner as in the preparation of Gel PSG 51 in Example 3.

A) Glycerol 80 g

Viscalex HV.30 6 g 10 mesh rubber crumb 35 g 40 mesh rubber crumb 7 g 0.370 sodium hydroxide solution 12 g 140 g B) Diethylene glycol (Digol) 80 g

Viscalex HV.30 22 g water 10 g 20 mesh rubber crumb 30 g 40 mesh rubber crumb 6 g 0.880 ammonium solution 2.5 g

Ucon 50 HB 260 (defoamer), 2 g 152.5 g C) Glycerol 80 g

Viscalex HV.30 7.5 g water 7.15 g

Ucon 50 HB 260 10 g 20 mesh rubber crumb 40 g. 40 mesh rubber crumb 8 g 3% sodium hydroxide solution 14 g_ 166.3 g

Ucon 50-HB-260 was added to improve the lubricating properties and sprayability of the gel when sprayed into the ring. Example 5;

The inner surface of the modern 155/65 - 310 seat belt tire is slightly concave. Due to the large radial forces acting on the rotating ring, the gelled lubricant moves and forms a gel pond in the concave top, the central part of which is> 11 63773 substantially deeper than the edges. It is clear that the width of the gel across the loan depends on the gel volume in the ring and the shape of the inner surface of the loan.

The following experiment to determine the effective hole sealing width of the gel was performed with a 155/65 -310 safety ring of normal production. The tread ribs were punctured at six intervals as follows:

Hole A 20 mm from the center of the tread - left B 37.5 mm from the center of the tread - left C 50 mm from the center of the tread - left D 20 mm from the center of the tread - right E 37.5 mm from the center of the tread - left F 50 mm from the center of the tread - left

The tire was mounted on the rim and the puncture rates were given in the following table: 1.1 / 2 "round pawls were used to close the holes as needed.

Time A B C D E F

0 2.11 kp / cm2 2.11 kp / cm2 2.11 kp / cm2 2.11 kp / cm2 2.11 kp / cm2 2.11 kp / cm2 15 sec 2.01 kp / cm2 2.01 kp / cm2 2.04 kp / cm2 1.94-kp / cm2 2.04 kp / cm2 2.01 kp / cm2 "30 sec 1.90 kp / cm2 1.94 kp / cm2 1.94 kp / cm2 1, 83 kp / cm2 1.97 kp / cm2 1.90 kp / a. ' 34 sec 1.79 kpcm2 1.86 kp / cm2 1.84 kp / cm2 1.69 kp / cm2 1.92 kp / cm2 1.79 kp / cm2 1 min 1.69 kp / cm2 1.76 kp / cm2 1.76 cp / cm2 1.55 cp / cm2 1.84 cp / cm2 1.69 cp / cm2 * 2 min 1.38 cp / cm2 1.48 cp / cm2 1.48 cp / cm2 1 , 12 cp / cm2 1.62 cp / cm2 1.36 cp / cm2 * 4 min 0.81 cp / cm2 0.98 cp / cm2 not 0.49 cp / cm2 1.27 cp / cm2 0.81 cp / cm2 an * 8 min 0.28 kp / cm2 0.38 kp / cm2 measured 0 kp / cm2 0.77 kp / cm2 0.24 kp / cm2

The ring was removed from the rim and all holes were closed with 1 1/2 "round nails and the central area inside the bracket was evenly coated with 400 grams of Gel PSG 55 consisting of: Ethanediol 165.0 g

Viscolex HV.30 27.5 g

Water 33.0 g 10 mesh rubber crumb 137.5 g 40 mesh rubber crumb 27.5 g 0.880 ammonia 5.5) 11.0 g water 5-S 401.5 g. f- 12 63773

The tire was reassembled on the rim, inflated to a pressure of 1.76 kp / cm and tested on the road for 88 km up to a speed of 110 km / h to smooth the gel. The nails were then removed alternately as shown in the previous examples with the following results:

Experience Km at 80 km / h Tire pressure - 0 1.62 kp / cm2

Nail A removed 2.7 .1.48 kp / cm2 12.1 1.41 kp / cm2

Nail D removed 2.7 1.34 kp / cm2 12.1 1.34 kp / cm2

Nail B removed 2.7 1.27 kp / cm 2

12.1 1.27 kp / cm2 2

Nail E removed 2.7 1.20 kp / cm 12.1 1.27 kp / cm 2

Nail C removed 2.7 0.70 kp / cm2 12.1 0.35 kp / cm2 41.0 0.24 kp / cm2

The car was stationary and the 0 kp / cm tire was allowed to cool for 15 min.

53.1 0.14 kp / cm 2 57.0 0.11 kp / cm 2

The car was stationary and the 0 kp / cm tire was allowed to cool for 1 hour 77.9 0.09 kp / cm2 105.0 0.09 kp / cm2 132.0 0.07 kp / cm2 138.1 0.04 kp / cm2 147.5 0 kp / cm ^ •. i

The wheel and tire were removed from the car and re-inflated to 2.11 kp / cm with nails A, D, B, E and C still removed from the tire and these holes were checked for leaks. Only hole C leaked air and other holes, i.e. two 20 mm and two 37.5 mm from the center line of the tread were sealed against a full pressure of 2.11 kp / cm. ! i

The leakage of hole C (50 mm from the center line of the tread) was measured with the following results: 13 63773

Time Pressure 0 2.11 kp / cm2 15 sec 2.07 kp / cm2 2 30 sec 2.04 kp / cm 45 sec 2.00 kp / cm2 2 1 min 1.97 kp / cm 2 2 min 1.83 kp / cm 2 4 min ly60 kp / cm 8 min 1.23 kp / cm2 15 min 0.75 kp / cm2 30 min 0.42 kp / cm2

Comparing the table above with the initial leakage rate of hole C, it can be seen that there has been a significant reduction in leakage. This was probably due to the way the holes were made, in which the ring was punctured with heated wire. In this case, there is likely to be broken rubber on the inner surface of the hole which, as can be easily imagined, could in part seal the hole, as the flat tread and the buffer layer constantly bent and compressed it. However, this does not eliminate the fact that after the tire was allowed to cool and fully collapse, it was possible to develop a pressure greater than 0.07 kp / cm by driving more than 50 km at 80 km / h, relying only on the generation of steam and hot air. The signs suggest that if the tire had been allowed to cool for some time, during which time the air inside the tire would have cooled, the same number of extra kilometers could have been measured and this with an unsealed hole. This fact could not be verified because the nail F caused serious second damage to the inside of the tire.

Example 6:

Gel PSG 60B was prepared by mixing the following ingredients in the following order:

Gel B 308/2 100 g water 5 g 10 mesh rubber crumb 50 g 40 mesh rubber crumb 10 g I - r —- ...

165 g

A

* 2 14 63773

The 155/65 to 310 tire used in Examples 1, 2 and 3 was cleaned and the holes closed with 1 1/2 "nails. The inner surface of the tire bead was evenly coated with 360 grams of PSG 60B gel, which was mounted on the rim and inflated to 1.76 kp / cm. the tire was rotated on a drum for 30 minutes at 110 km / h to level the gel and move it to equilibrium, then sealed in an oven at 70 ° C for three days before being installed in a car and tested with the following results:

Experience Km at 85 km / h Tire pressure <* 0 1.83 kp / cm

Nail A removed Approx. 15 sec. delay due to traffic, then 2.7 0.21 kp / cm2 22.5 0.23 kp / cm2

The tire pressure was raised to

1.76 kp / cm2 Tire failure A

0 1.34 kp / cm2

Nail B removed 2.7 0.45 kp / cm2 12.1 »0.47 kp / cm2 2

Nail D removed 2.7 0.24 bp / cm2 9.7 0.24 bp / cm2

Hole leakage rates increased from Example 1. Hole A was measured with the following results:

Time Pressure 0 0.10 kp / cm2 15 sec 0.98 kp / cm2 30 sec 0.42 kp / cm2 45 sec 0.14 kp / cm2

When these results are compared with the leakage rates measured in Example 2, it can be seen that the assumptions were confirmed.

Although the PSG 60B gel had been aged for three days at 70 ° C, it effectively sealed three test holes with a leakage rate greater than 90-95% of all naturally occurring tire failures.

In the above examples, the size distribution of the particles 15 63773 of the rubber crumb used was as follows: a) 10 mesh sieve Remains on a 7 mesh B.S. sieve (opening 2.36 mm). ./.make· 1% Passes 7 mesh sieve, stays on 10 mesh sieve (opening 1.70 mm) max.25% Passes 10 mesh sieve, stays on 14 mesh sieve (opening 1.18 mm) 20-50% Passes 14 mesh sieve, ice on 18 mesh sieve (aperture 850 microns) 5.25% Passes through 18 mesh sieve, ice on 22 mesh sieve (aperture 710 microns) 5-15% Passes through 22 mesh sieve, ice on 36 mesh sieve (aperture 425 microns) 5- 25% Passes through a 36 mesh screen 5-20% b) Passes through a 40 mesh screen Remains on a 420 micron screen max. 1% Passes through a 420 micron screen, remains on a 250 micron screen 40-60% Passes through a 250 micron screen, remains on a 180 micron screen 20-30% Passes 180 micron sieve, remains on 150 micron sieve 5-15% Passes 150 micron sieve 10-20%

The gel used in Example 5 above used a rubber grit with a density of 1.18 g / ml per 360 g of a gel-crumb mixture having a density of 1.104 g / ml. The width of the coated inner surface of the tire was about 110 mm, provided that the total coated surface was 2,161,200 mm.

In this example, the rubber crumb thus constituted 34.1% by volume of the gel / crumb mixture and had a crumb of 0.698 mm per mm 2 of coated tire surface area.

Experiments have shown that below a certain rubber crumb / gel ratio, the effectiveness of the sealant decreases below an unacceptable level. Using a standard test hole comprising a clean hole burned through the tread of the tire, through which the amount of air leaking was 6 to 50 cm / sec at a tire pressure of 0.35 kp / cm, the experiments showed that the rubber grit / gel ratio should not be less than the following - 16 63773 with a 3 mm thick hole-sealing layer in the legal part of the tire 155/65 - 310 in the safety tire.

Gel B.308 / 2 118 g 10 mesh rubber crumb 12.3 g 40 mesh rubber crumb 1.46 g water 5.00 g 141.00 g

Total density of gel / crumb mixture = 1.08 g / ml.

In this example, the rubber crumb constituted 8.94% by volume of rubber crumb / 2 3 of the gel mixture and 0.185 mm of rubber crumb per mm of inner surface of the ring. It is obvious that the latter number is only a guide number, because the actual distribution in the pavement, which is pak-, constricted in the tire law area, means that the actual crumb volume / tire area ratio will be smaller next to the tire tread edges.

Example 7:

The gelled polybutene sealant composition was prepared by mixing the following ingredients together.

Good 30 (polybutylene, manufactured by B.P.

Chemicals Limite.d) 90 g AC 6 (low molecular weight polyethylene, manufactured by Allied Chemicals Limited) 10 g 30 mesh rubber crumb 30 g_ 130 g

Heat 30 was heated to about 130 ° C whereupon AC 6 was added and the mixture was stirred until the liquid was clear and mobile. The rubber crumb was then mixed with it and stirring was continued until the temperature had dropped below 100 ° C to ensure that no rubber crumb precipitated. The composition thus prepared was tested and found to be stable on a vertical aluminum surface up to a temperature of 98 ° C, after which it began to drain and finally at 103 ° C it flowed freely. At a temperature of about 120 ° C, the composition was liquid and mobile and corresponded to an aqueous slurry, and agitation of the Jjat image was necessary to prevent the crumb from precipitating. The spraying test showed that if the temperature of the composition was maintained at 120 ° C and the spray gun was heated to about 110 ° C, the composition was easily sprayable onto the inner surface of the ring.

A hole sealing test was then performed using a 155/65 to 310 seat belt ring.

At the center of the tire, four holes were burned at regular intervals with heated wire, and the leakage rate of each hole was measured by inflating the tire with air to a pressure of 2.11 kp / cm and noting the pressure loss time: 2 *

Time Hole A Hole B Hole C Hole D

0 2.11 2.11 2.11 i 2.11 15 sec 2.00 1.99 1.79 '1.62 30 sec 1.92 1.90 1.51 1.30 45 sec 1.86 1 83 1.30 1.05 1 min 1.71 1.76 1.08 0.84 2 min 1.43 1.48 0.51 0.34 3 min 1.20 1.27 0.21 0.09 4 min 0.97 1.05 0.07 0.07 5 min 0.80 0.89 6 min 0.63 0.77 8 min 0.42 0.59, 10 min 0.28 0.37 12 min 0, 16 0.25 14 min 0.09 0.16 16 min 0.07 0.11 18 min 0.07 300 grams of the above gelled polybutane sealant composition was heated to 130 ° C and sprayed hot into the inner area of the tire and on the shoulders evenly. to a coating having a thickness of 2 mm · At 130 ° C the composition was very fluid and could be sprayed without difficulty with a conventional air spray gun, but when the temperature dropped below 100 ° C it gelled to a rigid and stable coating in the ring. The composition was probably cooled and gelled immediately with a spray gun from my syringe! thereafter, however, this was not significant because the consistency of the gelled composition allowed the formation of a uniform coating on the inner surface of the ring portion and the oil caps.

To close the holes in the tire and simulate permeable precursors, standard 1 1/2 "round wire nails were inserted into the holes. could be found if the mere removal of the nail sucked the sealant into the hole and sealed it, however, none of these four holes sealed at this low pressure.

The nails were re-inserted into the ring to close the holes, and after the internal pressure was raised to 2.11 kp / cm, the wheel was rotated on a drum for 15 minutes at a speed of 96 km / h with a nominal load. The holes were then tested as follows: a) the tire pressure was reduced to 0.35 kp / cm and the nail was removed from the hole - the hole did not seal. The wheel was then rotated for a further 5 minutes at 80 km / h, after which it could be seen that the hole had sealed and the pressure was 0.21 kp / cm 2. The tire pressure was raised to 1.83 kp / cm and the hole remained tight.

b) at a tire pressure of 1.83 kp / cm, the nail was removed from hole B, so that the hole did not seal. The wheel was then rotated for a further 5 minutes at 80 km / h, after which it could be seen that the hole had sealed at a pressure of 1.62 kp / cm. The tire pressure 2 was raised to 2.46 kp / cm, leaving both holes A and B tight.

c) at a tire pressure of 2.11 kp / cm, the nail was removed from hole C so that the hole did not seal. The wheel was then rotated for another 5 minutes at 80 km / h, after which it was found that the hole had sealed at a pressure of 0.28 kp / cm. Ring 2 was inflated to 1.97 kp / cm, leaving the hole tight for about one minute, at which point the seal failed. Hole C was closed again with a nail.

d) at a tire pressure of 1.83 kp / cm, the nail was removed from the hole D, so that the hole did not seal. 5 hours later, the tire pressure was still 0.56 kp / cm.

From this experiment, it is apparent that rotation of the wheel was necessary to transfer the sealing composition to the hole. Example 8:

Gel PSG 132 was prepared by mixing the following ingredients together in the following order at ambient temperature.

A

19 63773

Parts by weight

Hyvis 10 (polybutene manufactured by B.P.-Chemicals Ltd) 94

Aerosil 300 (silica) 6

Triethyleneamine 1 20 mesh rubber crumb 35_ 136

The mixture was heated to 120 ° C and 350 grams were evenly sprayed on 155 / 65-310, the inner surface of the seat belt area. Although the mixture was stable, and thus did not flow vertically, at least at temperatures below 150 ° C, heating it to 120 ° C was intended to soften it and make spraying the substance easier and more satisfactory as regards directing the spray and to make the coating smoother.

The tire was then mounted on a rim and subjected to a mechanical test at a speed of 128 km / h and a load of 250 kg, after which the balance and evenness of the tire were found to be unchanged and the gel completely stable.

In addition, additional batches of the mixture were taken and tested as follows: a) In an oven at 80 ° C, the mixture being unchanged after two weeks.

b) In an oven at 120 ° C, at which point there was no vertical flow of the mixture after 24 hours.

c) In a centrifuge with a diameter of 48 cm and a rotation speed of 3000 rpm, whereby insignificant separation was observed in the mixture after 8 hours. During this experiment, the internal temperature of the centrifuge was 45 ° C.

Example 9:

Gel PSG 133 was prepared by mixing the following ingredients together in the following order at 130 ° C:

Parts by weight

Hyvis 10 (polybutene, manufactured by B.P. Chemicals Ltd.) 85 AC 8 (low density polyethylene, manufactured by Allied

Chemicals Limited) _9_ 94 5 * 20 63773

After the polyethylene had dissolved, the following substances were added: Erosilium 300 (silica) 6 20 mesh rubber crumb 35 135

The mixture was allowed to cool. It was heated, later to 120 ° C, and 350 grams were evenly sprayed onto the inner surface of the 155/65-310 seat belt ring.

Example 10:

Gel PSG 141 was prepared by mixing the following ingredients together in the following order at 130 ° C.

Good 10 92 parts by weight AC 8 6 parts by weight

After dissolving the polyethylene, 4 parts by weight of Erosil 300 (silica) and 35 parts by weight of 20 mesh wood powder were added.

300 grams of this gel was sprayed hot on the inner surface of the outer part of the 155 / 65-310 seat belt.

The addition of finely divided silica (Aerosil 300) increased the viscosity of the composition so that it did not settle even at 130 ° C on the vertical surface of the glass plate. The viscosity at 130 ° C, on the other hand, was low enough that the composition could be sprayed directly onto the inner surface of the tread portion of the tire tread.

The combination of fibrous wood powder and granular rubber grit was found to be a very satisfactory hole sealant without interfering with the injectability of the heated composition.

When testing the composition in the tire, it was found that at low temperatures, 10 ° C to 20 ° C, its viscosity was too high to run into the hole at a vehicle speed of 80 km / h, but as the tire pressure dropped the tire heated rapidly and reduced the composition viscosity to such a level. that it could run into the hole and seal it. Thus, in one example, a standard hole was made in a cold ring set at a pressure of 1.76 kp / cm 2 (in this case, the cold ring means that the ambient temperature is 20 ° C). The hole did not seal when the tire was driven at 80 km / h. As the pressure decreased, the temperature of the tire rose and finally the hole sealed at a tire pressure of 1.23 kp / cm. By then, the temperature of ring 4 21 63773 had risen to 45 ° C. Since then, three other standard holes in the same ring have been sealed and the pressure loss was at most 2 2 0.07 kp / cm, i.e. the tire pressure was set at 1.76 kp / cm before each hole was made and the tire pressure after sealing of each hole was thus 1.69 resp. 1.72 1.72 kp / cm.

Example 11:

Gel PSG 175, comprising the following ingredients:

Parts by weight

Good 10 (polybutene, manufacturer '.

B.P. Chemicals Ltd) 94

Rigidex 140/60 (high density polyethylene, manufactured by B.P. Chemicals Ltd) 2 AC 8 (high density polyethylene, manufactured by Allied

Chemicals Limited) 4

Polysar 301 (butyl rubber) 2 20 mesh rubber crumb 50-150 was prepared by dissolving Rigidex 140/60, AC8 and butyl rubber as a 33% solution of polybutylene and stirring at 180-190 ° C. The rubber crumb was then added to the hot solution and stirred while maintaining the temperature above 140 ° C.

350 grams of this mixture was sprayed hot at 140-150 ° C at 155/65-310 onto the inner liner of the tire to cover the tread area with a layer of about 2-3 mm and when tested it was found to seal the standard holes satisfactorily.

The tire of the present invention will now be described, by way of example, with reference to the accompanying drawing, which shows a section of a safety ring mounted on a wheel rim.

The drawing shows a belt ring 1 having a tread portion 4 supported by a buffer layer structure 2. The inner surface of the tread portion 4 is coated with a layer 5 of gelled lubricant containing a solid sealing agent sealing the holes. The tire is mounted on a two-piece wheel rim 6.

Λ *

Claims (17)

63773 22 Claims; A lubricant composition for application inside a tread of a pneumatic tire to facilitate movement between the contacting inner surfaces of the tire when the tire is used in a compressed state, characterized in that said composition comprises: polybutene; acrylic polymer or polyolefin as a polybutene gelling agent; a finely divided solid leakage sealant having a sealant particle size of -7 mesh B.S. +10 mesh B.S. and a fraction passing through a 150 mesh screen, wherein the fine solids by volume are at least 8% but less than 66% of the total volume of said composition. Lubricant composition according to Claim 1, characterized in that the gelling agent is polyethylene. Lubricant composition according to Claim 2, characterized in that the amount of polyethylene is 6 to 10% by weight of the total amount of polybutylene and polyethylene. Lubricant composition according to Claim 2 or 3, characterized in that the polyethylene is a mixture of high-density and low-density polyethylene. Lubricant composition according to Claim 4, characterized in that the amount by weight of low-density polyethylene is greater than the amount by weight of high-density polyethylene. Lubricant composition according to Claim 4 or 5, characterized in that the density 3 of the high-density polyethylene is about 0.96 g / cm 3 and that the density of the low-density polyethylene is in the range from 0.92 to 0.93 g / cm 3. Lubricant composition according to one of the preceding claims, characterized in that the polybutene is polyisobutylene. Lubricant composition according to Claim 7, characterized in that the polyisobutylene has a 1-butene content of up to 10%. Lubricant composition according to one of the preceding claims, characterized in that it contains a polybutene-soluble elastomer. Lubricant composition according to Claim 9, characterized in that the elastomer is butyl rubber, ethylene propylene rubber or natural rubber. Lubricant composition according to claim 10, characterized in that the content of said elastomer is approximately 2% by weight of polybutene. Lubricant composition according to one of the preceding claims, characterized in that it contains silica as an additional gel. Lubricant composition according to one of the preceding claims, characterized in that said leakage sealant has a density of 0.8 to 1.5 g / cm 3. A lubricant composition according to claim 13, characterized in that said leakage sealant consists of a rubber powder. Lubricant composition according to any one of the preceding claims, characterized in that said leakage sealant is wood flour. Lubricant composition according to one of the preceding claims, characterized in that the amount of said leakage sealant is 33 to 35% by weight of the amount of polybutene. Lubricant composition according to one of the preceding claims, characterized in that the composition has a viscosity of 2 -1 in the range from 2000 to 15,000 Ns / m at a shear rate of 0.3 s and a temperature of 20 ° C. 24 63773