Sealant for tire repairing

Abstract

Subject matter disclosed herein relates to sealant for tire repairing and more particularly, relates to sealant composition for repairing tire punctures and a method of preparing the same.

Claims

1. A tire puncture sealant, comprising a rubber latex, an anti-freezing agent, a surfactant and solid particles; wherein the sealant has an expansion ratio of above 200% measured by a blender test according to ASTM D3519-88 and said surfactant has an acetate group or an amine oxide group and said surfactant comprises a zwitterionic surfactant of formula (I) or (II) or (III) shown below: ##STR00005## where A is an acetate group: ##STR00006## M is monometallic ion, RCO is C6-C24 acyl or mixtures thereof, x is 0-4, a is 0-1 and b is 0-1, wherein a+b=1; ##STR00007## where R is C.sub.6-C.sub.24 alkyl or mixtures thereof; ##STR00008## where RCO is C.sub.6-C.sub.24 acyl or mixtures thereof and x is 0-4.

2. The tire puncture sealant according to claim 1, the tire puncture sealant being capable of expansion by gas introduction during injection of sealant.

3. The tire puncture sealant according to claim 2, wherein the gas comprises any substance presented in gas phase with a density of 0.179-1.2 kg m.sup.3 under normal condition.

4. The tire puncture sealant according to claim 2, wherein the injection of sealant comprises a process of placing the tire puncture sealant into a tire by any means with aid of gas flow.

5. The tire puncture sealant according to claim 1, wherein the rubber latex comprises a natural rubber latex and/or a deproteinized natural rubber latex.

6. The tire puncture sealant according to claim 1, wherein the anti-freezing agent comprises at least one selected from the group consisting of an ethylene glycol, a propylene glycol, a 1,3-propanediol, a glycerin and mixtures thereof.

7. The tire puncture sealant according to claim 1, wherein the surfactant is an amphoteric surfactant.

8. The tire puncture sealant according to claim 1, wherein the solid particles comprises a mixture of one or more solid particles having different hydrophobicity or shape.

9. The tire puncture sealant according to claim 1, which has an expansion ratio above 200% measured by a blender test at a temperature 30 C.

10. The tire puncture sealant according to claim 1, wherein the surfactant further comprises at least one selected from the group consisting of non-ionic surfactant, anionic surfactant, and cationic surfactant.

Description

EXAMPLES

(1) The present invention is illustrated in reference to the following examples.

(2) <Preparation of Sealant>

(3) The sealant according to the present invention is prepared by mixing two parts together.

(4) The first part, part A, contains water/solvent, antifreezing agents, foaming agent, surfactant, additive, emulsifier.

(5) The second part, part B, contains water/solvent and tackifier (latex).

(6) In typical preparation, Part A is added to Part B. The pH of the final composition is adjusted to above 8.5 by addition of alkaline including but not limited to NaOH, KOH, ammonia, tetramethylammonium hydroxide.

(7) <Evaluation>

(8) Foam sealant is tested for two properties, (1) foaming property and (2) sealant performance, and the test results of the Examples according to the present invention are provided in the following Table 1.

(9) <Foaming Properties>

(10) Foaming properties are evaluated by the volume expansion of the sealant after bubbling with gas under 30 C.

(11) For the foaming properties, the expansion factor, , is defined as the ratio of final sealant volume to initial sealant volume. The final sealant volume comprises of the original sealant and gas embed inside, whereas initial sealant volume comprises of only the volume of liquid partition.

(12) $=\frac{\mathrm{final}\mathrm{sealant}\mathrm{volume}}{\mathrm{initial}\mathrm{sealant}\mathrm{volume}}$

(13) Gas can also be injected to the sealant by different means including but not limited to bubbling, agitation, spraying, and bubbling under agitation

(14) Foaming properties are also evaluated by ASTM D3519-88.

(15) The test was conducted at 8000 rpm50 rpm with 250 ml container.

(16) The expansion ratio is denoted as

(17) $=\frac{\mathrm{Maximum}\mathrm{Height}\mathrm{of}\mathrm{Foam}\mathrm{at}\mathrm{zero}\mathrm{time}}{\mathrm{Initial}\mathrm{Height}\mathrm{of}\mathrm{Sealant}}$

(18) <Sealing Properties>

(19) The sealing properties are determined by the ability on sealing tire having puncture.

(20) In a typical test, certain volume of sealant was injected to a completely deflated tire installed on a vehicle.

(21) Inflation is completed after sealant has been placed inside the tire.

(22) The vehicle is allowed to travel for certain distance and/or static for certain time.

(23) The sealant is defined as good when pressure maintained in the tire can support for typical operation.

(24) In an embodiment of the present invention, the viscosity value of the sealant is in a range below 346 mPa.Math.s

(25) In an embodiment of the present invention, the pH value of the sealant composition is from 8.5 to 11 (under room condition) and preferably in a range of 9-10.

(26) The sealant composition according to the present invention has insignificant settling within 24 hours. The use of rigid particles having low density such as air balloon may prevent the settling problem.

(27) In order to make the technical features, the purpose and the technical effect of the present applications more clear, the present application will now be described in detail with reference to the accompanying examples.

(28) Seventeen Examples of sealant composition are shown as follows.

Example 1

(29) The sealant composition comprised 48.39 wt % antifreezing agent (propylene glycol), 20 wt % natural latex, 0.5 wt % amphoteric surfactant (Dodecyl dimethyl betaine, DDMB), 0.1 wt % anionic surfactant (tetraethyl ammonium), 0.2 wt % solid particles and balanced water. The pH of the sealant is 10.

Example 2

(30) The sealant composition comprised 48.39 wt % antifreezing agent (propylene glycol), 10 wt % natural latex, 0.5 wt % amphoteric surfactant (Dodecyl dimethyl betaine, DDMB) and 0.1 wt % anionic surfactant (sodium dodecyl sulfate), 0.5 wt % solid particles and balanced water. The pH of the sealant is 10.

Example 3

(31) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 10 wt % nature latex, 0.8 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), 0.9 wt % solid particles, 2.5 wt % organic solvent and balanced water. The pH of the sealant is 10.

Example 4

(32) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 0.8 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), 0.9 wt % solid particles and balanced water. The pH of the sealant is 10.

Example 5

(33) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 1.3 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), 0.9 wt % solid particles and balanced water. The pH of the sealant is 10.

Example 6

(34) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 0.88 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), 0.9 wt % solid particles and balanced water/solvent. The pH of the sealant is 10.

Example 7

(35) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 1.07 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), 0.9 wt % solid particles and balanced water/solvent. The pH of the sealant is 10.

Example 8

(36) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 0.8 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), 0.1 wt % anionic surfactant, 0.9 wt % solid particles and balanced water. The pH of the sealant is 10.

Example 9

(37) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 0.8 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), 0.6 wt % solid particles and balanced water.

Example 10

(38) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 0.8 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), and balanced water.

Example 11

(39) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 0.8 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), 2.5 wt % organic solvent and balanced water.

Example 12

(40) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 0.8 wt % nonionic surfactant (Tween-60), 0.4 wt % amphoteric (disodium cocoamphodiacetate (CAD-40)), 0.9 wt % solid particles, and balanced water.

Example 13

(41) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), 0.9 wt % solid particles, and balanced water.

Example 14

(42) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 0.8 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), 0.8 wt % nonionic surfactant, 0.9 wt % solid particles, and balanced water. The pH of the sealant is 11.

Example 15

(43) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 0.8 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (disodium cocoamphodiacetate (CAD-40)), nonionic surfactant, 0.9 wt % solid particles and balanced water. The pH of the sealant is 8.5.

Example 16

(44) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 20 wt % nature latex, 1.7 wt % amphoteric surfactant (Sodium Lauroamphoacetate), 0.2 wt % solid particles and balanced water. The pH of the sealant is 10.

Example 17

(45) The sealant composition comprised 48 wt % antifreezing agent (propylene glycol), 19 wt % nature latex, 0.8 wt % nonionic surfactant (Tween-60), 2 wt % amphoteric surfactant (Cocamidopropylamine oxide), nonionic surfactant, 0.9 wt % solid particles and balanced water. The pH of the sealant is 10.

(46) The measurements of the viscosity, the expansion factor and the expansion ratio as well as the seal test of the above Examples have been conducted and the results have been shown in the following Table.

(47) TABLE-US-00001 TABLE 1 Weight percentage Particles Antifreezing Solvent- Solvent- Anionic Cationic Nonionic Amphoteric DP-Latex Example Content Agent Inorganic Organic surfactant Surfactants surfactants surfactant Content 1 0.2 48.39 30.81 0 0.1 0 0 0.5 20 2 0.5 48.39 30.81 0 0.1 0 0 0.5 20 3 0.9 48.00 32.80 2.5 0 0 0.8 2.0 10 4 0.9 48.00 29.30 0 0 0 0.8 2.0 19 5 0.9 48.00 28.80 0 0 0 1.33 2.0 19 6 0.9 48.00 29.22 0 0 0 0.88 2.0 19 7 0.9 48.00 29.03 0 0 0 1.07 2.0 19 8 0.9 48.00 29.60 0 0.1 0 0.8 2 19 9 0.6 48.00 29.30 0 0 0 0.8 2 19 10 0 48.00 30.02 0 0 0 0.8 2 19 11 0.9 48.00 26.27 2.5 0 0 0.8 2 19 12 0.9 48.00 30.90 0 0 0 0.8 0.4 19 13 0.9 48.00 30.10 0 0.1 0 0 2 19 14 0.9 48.00 29.30 0 0 0 0.8 2 19 15 0.9 48.00 29.30 0 0 0 0.8 2 19 16 0 48.00 30.30 0 0 0 0 1.7 20 17 0.9 48.00 29.30 0 0 0 0.8 2 19 Viscosity, Expansion Expansion Viscosity mPa .Math. s factor ratio Example pH (LT) (RT) () () Seal Test 1 10 246.8 >2.0 >2.0 Pass 2 10 276.8 >2.0 >2.0 Pass 3 10 >1.5 >2.0 Pass 4 10 346.0 >2.0 >2.5 Pass 5 10 41.8 >2.0 >2.0 Pass 6 10 143 38.7 >3.0 >3.0 Pass 7 10 102.0 43.5 >4.0 >4.5 Pass 8 10 5231 52.2 >5.0 >5.0 Pass 9 10 91.5 41.7 >5.0 >5.0 Pass 10 10 91.4 23.1 >2.5 >3.0 Pass 11 10 118 20.0 >2.5 >2.5 Pass 12 10 522 15.6 >2.0 >2.0 Pass 13 10 865 16.0 >2.0 >2.0 Pass 14 11 263 10.2 >2.0 >2.0 Pass 15 8.5 32.1 16.1 >2.0 >2.5 Pass 16 10 268 >2.0 >2.5 Pass 17 10 227 30.5 >2.0 >2.5 Pass