JPS5830000B2 - deflated tire lubricant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to pneumatic vehicle tire lubricants, and more particularly to lubricants for tires that run deflated or underinflated.

A fundamental problem with all pneumatic tires is that they often become underinflated or completely deflated, and when this occurs the tire must be replaced and a spare tire fitted.

If this happens, a flat tire can cause loss of control of the vehicle.

A tire that could run on a deflated tire was at the time a desirable goal for timer manufacturing technology.

If the tire can be driven some distance at X with the tire deflated, the driver will be able to drive with the deflated tire until a replacement tire is obtained or repaired.

This would eliminate on-road tire changes and reliance on spares.

The driver would also be able to drive with suddenly deflated tires until he found a safe place to stop, thus avoiding sudden stops on busy streets and traffic.

There are many problems associated with running conventional tires deflated.

Deflated tires make the vehicle unstable and difficult to maneuver.

A lack of inflation pressure may cause the tire bead to dislodge and eventually cause the tire to separate from the wheel rim.

Additionally, riding with deflated tires can be an unpleasant experience as there is virtually no cushioning between the wheel rim and the road surface.

A number of designs have been proposed to increase stability and ride comfort when the tire is deflated.

These proposals include U.S. Pat.

Other proposals, such as US Pat. Nos. 2,040,643.3,392,722 and 3,610,308, have special devices inside the tire.

A problem caused by running a deflated tire is friction caused by the upper and lower portions of the concave sidewalls rubbing against each other.

Friction generates excessive heat and causes significant wear and tear on the sidewalls.

It has been proposed to include either liquid or solid lubricants on the interior of the tire to reduce this friction.

For example, US Pat. No. 2,040,645 suggests graphite lubricants, and US Pat. No. 3,610,308
proposed the use of liquid silicone, and also U.S. Pat.
No. 39,829 and No. 3,850,217 describe the use of polyalkylene glycols, glycerol, propylene glycol, silicones and other lubricants.

However, these lubricants are not believed to be satisfactory as the preferred lubricants of this invention.

The lubricant of the present invention consists of a solution consisting of water and ethylene glycol, a small amount of polyethylene oxide, and one polysaccharide.
and a solution of polymer molecules with solutes consisting of, for example, the corrosion inhibitor sodium nitrite and the wetting agent Triton N-101.

Referring to FIG. 1, a pneumatic tire is shown.

The tire has a thick tread portion 11 extending circumferentially around the tire and a sidewall 12 extending from the tread portion along the side of the tire.

The tire is designed to be mounted on a common conventional wheel rim 13 having an outwardly funneled flange 14 of conventional design at its outer end.

A wire bead ring 15 is provided within the bead portion 16 of the tire and the sidewall contacts the rim 13 at the bead portion.

In accordance with normal tire construction, the beads are designed to hold the tire on the rim when the tire is inflated.

The tire inflation pressure forces the bead 15 against the flange 14, holding the tire on the rim and maintaining the tire inflation.

The tires shown may be of the conventional bias/belted or radial type.

These tires have two bias or radial plies 17 and 18 extending around the interior of the tire.

The ply stretches from bead to bead to form a bead ring 15.
Both ends of the ply 19 and 20
is located in the side wall area.

There are also two steel or fabric belts 21 and 22 extending circumferentially around the inside of the tire and located directly inward to the trend section 11.

Conventional rubber compositions are used to form the tire's tread and sidewall sections and the air-holding inner liner.

The special feature of this special tire is its circumferential locking (LOC).
king lug) 24.

This lug is the result of a specially designed increase in sidewall thickness at the end of the rim flange as shown.

Locking lugs 24 do not interfere with the normal characteristics of the tire when inflated.

However, when deflated, the locking lug 24
wraps around the flange 14 and tightens the tire against the rim 13.

The deflated or deflated tire is thus clamped onto the rim, allowing the tire to be driven deflated for a period of time.

The image shows size BR78-13 installed on a standard rim.
Illustrated SBR tubeless tire of size H
It will be appreciated that larger tires such as the R78i5 would have the same shape.

The rubber used in the tire can be the same as that used in conventional tires.

In such cases, the elastic rubber of the side wall portions may be SBR rubber having a Shore A Deuteron-Ter hardness in the range of 40 to 80.

Butyl rubber may be used for the inner liner to provide the best resistance to gas permeation.

When the upper and lower halves of the sidewalls come into contact during operation of a folded and folded tire, a seal is placed on the inner surface of the sidewall portion at 47 to reduce the friction and heat generated by their rubbing together. It is preferable to provide a lubricant.

The viscous lubricant used has excellent smoothness and temperature
It has a viscosity that does not appreciably increase as the temperature increases from 5°C to 85°C and stability when operated for long periods at high radial accelerations such as 200 g or more.

Preferred lubricants for use in the present invention have excellent lubricity, are compatible with the rubber of the inner tire liner, are stable and workable over a wide range of temperatures and shear rates, and are uniform in composition during service. It has a viscosity and composition similar to that of a dispersed material, and has puncture-occluding performance.

Prior to the present invention, there were no lubricants that met all of these requirements.

The preferred lubricants disclosed herein below meet all of these requirements.

Preferred lubricants of the present invention consist of high molecular weight polymeric materials dissolved in a solvent such as water and have high viscosity in the temperature range of 25°C to 90°C.

The molecular weight of the polymer is at least io, ooo and preferably at least 50,000.

The polymer mixture preferably has a high viscosity at 25°C (such as 100,000 cp or more) not much higher (e.g., no more than 10% higher) than the viscosity at 85°C.
Used to provide puncture-occlusive lubricant with

This may be accomplished by the use of small amounts of water-soluble gums or polysaccharides, as discussed below, usually less than 2% by weight.

Polysaccharide is 10,000 to 5 o, o o. or more.

The high polymer used with the polysaccharide is preferably selected to impart good elasticity and smoothness to the solution.

Excellent results are at least 10,000 and preferably 50,
Water-soluble high polymers such as polyethylene oxide, having a high molecular weight of 000 to 5,000 pOO,
IyoxWSR205","po 1yoxWSR
301'' as well as other common polyethylene oxide polymers.

Water-soluble gums or polysaccharides are used because they have a low temperature coefficient of viscosity.

Polysaccharide 6-bentosanes suitable for use in the present invention (
C5H804) n.

Hexosane (C6HIO05) n1 Gums, mucilage substances, derivatives thereof, etc., including starch, methylcelluloses and other celluloses, hemicelluloses, modified products and derivatives thereof, and similar water-soluble high polymers. It includes the class.

The molecular weight can be from 50,000 to 300,000 or more.

A number of different water-soluble gums or polysaccharides can be used, and these are described by F. Smith and R.
Textbook by R6 Montgomery, Chemistry of Plant Gums and Mucilages (TheCh
emistry of Plant Gums
and Mucilages) (Copyright 1959 by Reinhold Publishers).

Suitable water-soluble polysaccharides, gums and mucilages include, for example, xanthan gum, as described in the text book above;
Includes gum arabic, many other natural and synthetic gums and mucilages, and their derivatives.

The monosaccharide building blocks of gums, mucilages and vegetable polymers may vary and may be modified in various ways without, of course, destroying the usefulness of the polymers.

When the water-soluble polymers mentioned above are dissolved in water, they behave in a unique manner and assume a bulky profile leading to a rapid increase in solution viscosity.

An unexpected synergistic effect is achieved when two polymers, such as polyethylene oxide and polysaccharide, are dissolved in a water and ethylene glycol mixture resulting in high viscosity properties with excellent smoothness and the ability to operate over a wide range of temperatures and shear rates. It has been found that a puncture-sealing lubricant is obtained.

Preferred lubricants of this invention contain at least 20 parts by weight of water;
Ethylene glycol not containing 80 parts by weight, approximately 0.05
from 3 parts to 3 parts, preferably from 0.05 to 1.5 parts by weight of very high molecular weight polyethylene oxide, from about 0.05 to about 4 parts by weight;
and preferably no more than 2 parts by weight of high molecular weight polysaccharides.

The lubricant may also contain very small amounts of antioxidants and small amounts of other ingredients.

Preferably, it contains fibrous fibers or other suitable fillers in an amount such as 3 to 8 weight percent, preferably 4 to 6 weight percent.

The fibrous filler may consist of fibers having a length of 20 to 400 microns, for example.

The preferred lubricant is water and ethylene glycol, about 0.05
From about 2 weight percent polyethylene oxide polymer, from about 0.15 to about 2 weight percent polysaccharide, and from about 4 to about 6 weight percent fibrous fiber.

For water-ethylene glycol mixtures, the predominant portion of the mixture should be ethylene glycol to minimize volatilization losses.

A synergistic effect is demonstrated as shown by the examples that follow.

This is because the viscosity-temperature coefficient of the composite solution is lower than that of individual polymer solutions containing the same amount of fibers.

Additionally, the lubricant can be formulated so that the viscosity is relatively insensitive to temperature changes in the range of 25°C to 85°C.

The polymer and components of the lubricant are selected to provide the appropriate viscosity (Brookfield) for the desired effect.

For good smoothness, the viscosity should be at least 1000 centipoise at 25°C.

If good puncture sealing properties are also desired, the viscosity at 25° C. can be from 100,000 to 400,000 centipoise.

The viscosity may be such that the components of the lubricant remain distributed throughout the material during use, such that the lubricant remains at 70°C.
It is preferred that the ingredients remain properly distributed when continuously applied to 200g for 20 hours or more.

The total amount of polysaccharide and water-soluble resin may be very small if the molecular weight is very high and is usually not more than 5 weight percent.

However, if lower molecular weights are used, more may be necessary to obtain the desired viscosity.

For example, polyox (Polyox) with a molecular weight of 600,000
The amount of WSR205 may be 2 to 4 weight percent compared to 1 percent or less for similar polymers having molecular weights of 1 million to 5 million.

A series of polymer solutions were made for testing using formulations A, B, C, and D shown below.

Table I Weight parts CD 50 50 50 50 50 50 0.750,750.75 1.5-0951.5 Component A Ethylene glycol 50 Water (1) 50 Polyethylene oxide polysaccharide (KELZAN (2) (KELZAN)) (3) Tsurukaflock SW 40 4.0 3.0 3
．． 0 3.0 (4) Tsurukaflock BW200 2.0 1.5
1.5 The viscosities of polymer solutions having the compositions A-D in Table 1.5 were measured at 25°C and 88°C using a conventional Pruckfeel scale, type LVT, and were determined as shown in Table 1 below. The results were obtained.

Display viscosity (″/f A B CD poise)
□ Percent change at 25°C and 88°C 183Ω00 8,150 195,000290,0
00154.000 21475 17(X)00 3
01ρ0O16% -6% -13% +3.8% In formulations A through A, the polyethylene oxide is Polyox WSP3 made by Union Carbide.
01, the polysaccharide is produced by Kelco Corporation (Kelco
Kelsan xanthan rubber (molecular weight 1o.

It contains D-glucose, D-mannose, and D-glucuronic acid with a linear β-bond skeleton, and has side chains (D-mannose/8 residues, D-glucose/16 residues).

:Kelzan Xanthan gum).

The polyethylene oxide used has a molecular weight of approximately 4 million.

The Solka flock is from Brefko's Dicalite Division of Gr.
efco) and is made of conventional fibrous fibers.

The 5W40 fibers are about 100 microns long and about 16 microns thick, and the BW200 fibers are about 50 microns long and about 17 microns thick.

Wetting of the inner liner by lubricating oil was not a problem.

However, it has been found that some additives reduce the surface tension of the lubricant to a significant degree, thus providing better wetting.

Such materials are manufactured by Rohm and Haas.
Triton (Triton N 101), a nonylphenoxy polyethoxy containing 9 to 10 moles of ethylene oxide, prepared by
).

As shown in Table 1, polymer solution B, just containing polyethylene oxide, exhibits a severe decrease in viscosity upon heating.

However, polymer solutions C and D containing a small amount of polysaccharide hardly feel any temperature.

The coefficient of friction of a typical vulcanized radial internal liner formulation sliding against itself was first measured without lubricant and then in the presence of silicone graphite lubricant.
Finally, measurements were taken in the presence of the polymer solution lubricant C described above.

The results are shown below. Table ■ Lubricant used Static friction coefficient Dynamic friction coefficient No lubricant 0.92 0.85 Silicone graphite lubricant 0.20 0.12
Polymer solution lubricant 0.07 0.06 The result is that polymer solution lubricant is about 2
twice as effective, which indicates that it reduces the coefficient of friction by a factor of 10 or 10.

In addition to positively influencing the rheological behavior of the lubricant, the addition of fibrous fibers can impart puncture sealing ability to the lubricant.

The lubricant can successfully seal punctures in subscale tires resulting from cheap needles.

If a puncture occurs with a larger size needle, air leakage may occur, but the puncture area is coated with a small amount of lubricant to reduce leakage.

The viscosity of the lubricant is essentially unaffected by shear when subjected to a shear force at a rate of 30 seε1 for 23 part hours.

The fibrous fibers remain suspended under the influence of a centrifugal force equal to that of a tire traveling at approximately 50 mph (approximately 80 Km/hr).

Lubricants C and D were each heated at a temperature of 71°C for 24 hours at approximately 220°C.
After being subjected to a large centrifugal force of g, the lubricant remains a homogeneous solution with the fibers still uniformly dispersed.
〕Ta.

A similar test of Lubricant B without polysaccharide, on the contrary, resulted in a non-uniform distribution of fibers.

The lubricant does not swell the internal liner formulation of a typical radial tire.

Samples of radial tire internal liner formulations and urethane formulations are soaked in a lubricant solution for over two weeks at 50°C.

Only negligible changes in sample dimensions were observed.

Three sizes of BR78-IB steel radial tires were coated with the lubricant formulation described below.

Approximately 1 pound was used for each tire.

These tires were built to commercial specifications except for the sidewalls having higher than normal stiffness.

Two similar tires were served as controls.

The valve stem was removed so that the tire would not hold air.

These are mounted on 5" rims and are 784 lbs.
25 on the pulley wheel loaded with 5,9 kg)
It was forced to travel at speeds of mph.

The table ■ below shows the number of miles before failure when driving under deflated conditions.

It has been seen that tires containing lubricant have traveled substantially more miles than tires without lubricant.

Table ■ Tire Deflated row number Lubricant Bead fixing mechanism Fill until damage occurs during driving None Rim well band 212
None Mechanical screw fastening 193 A Li Mechanical screw fastening 434 A Li Mechanical screw fastening
425 A Ri Rimwell Band
The lubricant solution used in the tires on the 48 was made using the formulation shown below.

Component ethylene glycol 7 () @ [E water
(1) 30v'B polyethylene oxide WSR301-05 parts (2) polyethylene oxide WSR205.03 parts (3).

, □ 5 parts "The" (4) Triton N-10110, 0 parts sodium metasilicate, 075 parts sodium nitrite, 075 parts diethylenetriamine, 01 parts thiourea
, 01 Entire Part 110.4 A further series of tires manufactured by The General Tire and Rubber Company to demonstrate the effectiveness of the lubricants of the present invention were prepared using tire dimensions BR78-B Sure Steel (
A radial tire was coated with a solution of the above lubricant of the invention.

In each case the tires were mounted on the right front of a Vega Automobile with the loads specified in the table below.

The rim well band is made of rubber and is
It fit neatly into the well, thus preventing the bead from becoming dislodged.

In one example, a tire without lubricant was used as a control.

The valve was removed and testing began without any tire warm-up period.

The mileage for each tire is shown in the table below.

Table■ Durable tire load Lubricant 3, -5 Fixing mechanism Ear, Number Amount in pounds 1 970 None Rim well band 25.32
970 11b Mechanical screw fastening 49.9397
01]b Rim well band 70,9 tire negative
Load lubricant number 17 t'.

Quantity Bead fixing mechanism Durable fill count 4 970 11b Mechanical screw fastening 42.95
970 21bs, mechanical screw fastening 65.66
1080 11b, rimwell band 22.7
7 1080 21bs, Rimwell Reno Kundo 28.8 The lubricant can be used over a wide temperature range, from about -35°C to about 110°C.

This range can easily be expanded further by increasing the ethylene glycol content of the lubricant at the expense of water and minimizing the expected impact on other properties.

The term high polymer, as used herein and in the claims, refers to polymers having very high molecular weights, such as 50,000 or more, and which include rubbery, slimy and other polymers. The term aqueous as applied to a polymer indicates that the polymer is dissolved or swells to produce a viscous solution.

Unless the context indicates otherwise, parts are parts by weight and all percentages are by weight.

The invention described herein applies to conventional bias-belted or radial tire constructions, but the invention can be practiced with other standard tire designs.

Although the invention has been shown and described in connection with particular embodiments thereof, these are intended for purposes of illustration rather than limitation, and other variations and modifications may be made without departing from the intended scope of the invention. All within the spirit and scope will be apparent to those skilled in the art.

[Brief explanation of the drawing]

The drawing shows a cross section of a tire in a first embodiment of the invention. 11...Tread, 12...Side wall, 1
3... Rim, 14... Funnel-shaped flange, 15... Wire bead ring, 16... Tire bead part, 17 and 18
...Bias ply or radial ply, 19
and 20...both ends of the ply, 21 and 22...
... Belt, 24 ... Locking rack, 47
...The inner surface of the side wall that provides lubrication.

Claims (1)

Claims: 1 (a) 100 parts of a water-ethylene glycol mixture in which 1 to 4 parts of water are present for each 4 parts of ethylene glycol; (b) about 0.0 parts of polyethylene oxide having a molecular weight of about 4,000,000. (c) about 0.15 to about 2 parts by weight of a polysaccharide of kerzanxanthan gum having a molecular weight of at least about 10,000; and (d) cellulose fibers having a length not greater than 400 microns. A lubricant consisting of 3 to 8% by weight;
The tire has a viscosity such that the fibers remain dispersed when a centripetal force of 200 x g is applied by rotation at zero, and a viscosity of 1,000 to 400,000 centivoice at 25°C, i.e., the tire is not inflated, i.e., air Stable lubricant for pneumatic tires for use when driven with the tire removed. 2. The lubricant of claim 1, wherein the kerzanxanthan gum polysaccharide and polyethylene oxide are dissolved in an aqueous solution which is compatible with the adjacent rubber of the tire, i.e. does not have an adverse effect on the rubber. Claim 1, wherein the viscosity at 325°C is no more than 10% higher than the viscosity at 85°C and is capable of retaining proper dispersion of the filler when a centripetal force of 200 parts g is applied at 70°C. Top lubricant.